Nude mice, with the development of modern medicine, particularly oncology and immunology research needs, in the last ten years developed an animal model. It is a congenital defect of the mutant mice the thymus is due to the Ⅶ linkage group (linkage group) the occurrence of naked allele homozygous mutant mice the formation of new species. Nude (homozygous nu / nu mutant mice) mainly as glabrous (but you can see a hair, hair follicles histologically proven) and the lack of the normal thymus. Heterozygous mice (nn / +) in different areas, are normal. There are a number of mutant genes in mice, it can produce a performance for the hairless type (phenotype), such as athymic nude mice (nude,) nude (naked), hairless mice (hairless), no nose mice (rhinol ), not to be confused between these mutant mouse genes. The only feature is the thymus in nude mice defective phenotype, therefore, can not be "nude" and "hairless mice," the two words used interchangeably. The development of modern immunology, indicating the central immune organs thymus, thymus and thymus dependent revealed lymphocytes (t cells) function, which is a major breakthrough in immunology, creating new ways of cellular immunity. Athymic nude mice to study the most suitable natural thymic function animal models, its discovery and application, which greatly promoted the development of experimental immunology.
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The discovery and development of mice
无胸腺裸鼠 裸鼠的发现和发展情况
1962 Glasgow hospital grist in inbred mice of non-accidental discovery in the individual hairless mice. Four years later, the Edinburgh Institute of Zoology, La boiling Flanagan (flanagan) has confirmed that the hairless mouse alleles due to mutations in the chromosome, and found that the tissue from mouse skin and hairless mice in the past is different checked found, often due to chromosomal degradation, there is a new hairless gene, therefore, that spontaneous mutation is a new species and named as "naked" (nude) mice, with the "nu" is expressed as gene symbol, but it was not people's attention. 1968 Petit Louis (pantelouris) found that nude mice did not thymus, this cause the world great interest to workers in medical biology. In the past, for the study of cell immunology, usually drugs inhibit the production of mice and the role of t cells, or surgical removal of the thymus, these methods are often due to incomplete inhibition or surgery is not satisfactory, often leads to trial failed. The spontaneous mutation of the successful cultivation of athymic nude mice, the study provides a functional thymus, immunological mechanism of the ideal animal model. Weak immune system because the original species in nude mice, fertility is low, life is short, can not be used for practice. Therefore, people committed to breeding and transformation, respectively, and pure balb / c, c3h, c57bl / 6 mice were mated continuously breeding, won three inbred athymic nude animals (inbred nuede mice) new species, although a Some biological properties improved, but has not yet overcome these shortcomings, it is also almost inbred balb / c mice and Swiss mice were mated to obtain nih far athymic nude mice inbred (outbred nude mice), to overcome the above shortcomings, to a large number of breeding and promotion. Nude feed and breeding conditions more stringent requirements, our experience in this area have been reported. Some foreign countries after a period of exploration, 1969 Lijia De (rygaard) and ffiis report uses specific pathogen free (the spf) conditions, feed, although the success of breeding mice, but also occurred in infectious diseases. The past decade, many countries have established their own facilities, closed barrier system and the corresponding feed quality control measures to further promote the rapid development of research work in nude mice. 1978 Report of the United Kingdom lac news, except with the "nu" gene into inbred mice method was successfully developed into a clear genetic background of more than a thousand species of mice, but also nurtured athymic nude mice obese, non-thymus asplenia nude mice and nude rats, are expected in the near future, according to different experimental needs, will be producing more hybrid strains of non-thymus. At present, international specialized organizations have _set_ up an international management and application of the Commission in nude mice, respectively, in 1973, 1976, 1979, held three meetings in nude mice. Of experimental animals a large number of workers in the past in the mouse have been found breeding in the hairless mice, but not research. The last three or four years, due to the need for scientific research in nude mice caused from abroad. 1978 to 1980, the Chinese Academy of Medical Sciences who has subordinate units from France, Britain, the United States access to nude mice. Beijing Ministry of Health, Pharmaceutical and Biological Products imported from Japan in 1980 where the bare Shushu species were breeding, feed room at the barrier, after 16 months of feed, breed normally, and has been available to the research use.
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Nude mice and physiological characteristics of the main form of
无胸腺裸鼠 裸鼠的主要形态和生理特征
无胸腺裸鼠 裸鼠的主要形态和生理特征
无胸腺裸鼠 裸鼠的主要形态和生理特征
无胸腺裸鼠 裸鼠的主要形态和生理特征
The main characteristics of nude mice showed no hair (hairless), naked (nacked) and non-thymus (athymus). Newborn nude mice of the original species is characterized by a non-nose, toes often shrink, spiral-like deformity. Irregular estrous cycle of adult female rats, ovarian small, did not induce ovulation by human chorionic gonadotropin, male sperm tail was coiled like, no activity, so pregnancy is extremely low power. Newborn mice was significantly delayed 3 weeks after a long, generally have liver disease, high mortality, life expectancy at 15 to 26 weeks. Pure nude mice and the original species of the same shape, the body is almost hairless, and occasionally the back of the ribbon can be seen sparse hair, thin, smooth or wrinkled. Skin pigment balb / c nude mice were light red, supercilious; c3h nude as white, black eyes; c57bl nude black and gray to black, normal motor function. Specific lymphocytes in nude mice, the animals no thymus, induced t cell production obstacles. Although the t cells and b cells, the predecessor of the normal, the lack of thymus, it can not generate normal t cells. Because athymic nude mice, so the lack of immune response, immune deficient animals. Handle the normal thymus in the breastbone rear, close to the trachea, heart, belly, milky white fat-like, at about two leaves. Thymus and the immune machine has a close relationship now known thymus may secrete several biologically active peptide substances, collectively known as thymosin, it can stimulate the lymphatic tissue produces lymphocytes; so from the bone marrow, spleen and other tissues and lymph primitive cells mature into a cell t lymphocyte immune activity, which play a role in immunity. Congenital athymic nude mice and inhibit igm t cells have different antigen reaction is controversial, but in the absence of supporting cells to t no igg and iga response. T lymphatic system functions of nude mice immune function can be a variety of methods to prove. For example, land rat red blood cells (hrbc) or sheep red blood cells (srbc) repeated immunization, are not t cells can promote functional recovery, and then trinitrophenyl-hrbc or trinitrophenyl-srbc strengthen immunity, did not produce anti-trinitrophenol antibody. Beijing drugs test live rabies vaccine used to verify, also confirmed that both the production of antibodies or antibody own protection, nude and thymus in mice is completely different. Injection of rabies vaccine are the thymus of normal mice can produce good immunity, while athymic nude mice can not produce detectable immunological response.
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Nude mice in biomedical research of
无胸腺裸鼠 裸鼠在生物医学研究中的应用
无胸腺裸鼠 裸鼠在生物医学研究中的应用
In recent years, athymic nude mice as a new animal model, active in immunology, oncology, toxicology and other fields of research, especially in immunobiology, immunopathology, transplantation immunity, tumor immunity, the virus and bacteria immune to other fields, in just a few years to start a series of fruitful new research, to promote the various aspects of the work, as experimental immunology, experimental oncology and more for a new effective tool . Nude mice were dissected for histological examination confirmed that no normal thymus in nude mice, only remnants of the thymus or thymic epithelial abnormalities, which can not make t thymic epithelial cells in normal differentiation. Lymph node and spleen lymphocytes in the small number of thymus dependent areas, so the mice are lymphopenic animal disease, skin, hair shaft atrophy, follicular keratosis. T lymphocyte defects in nude mice, spleen cells showed loss of cell surface antigen and loss of θ mitogenic stimulus response capabilities. θ is the some of the lymphoid cell antigens in the t in front of a differentiated cell activation antigen. Since there is no t cells in nude mice, can not perform the function of the normal t cells, they are not in the mixed lymphocyte reaction mitogenic response, do not generate cytotoxic effector cells of concanavalin a lectin or no mitogen response p , the sensitivity of non-contact, non-transplant rejection, no graft-versus-host reaction and no auxiliary cells t cells or inhibit the formation of t. Without auxiliary cells in nude mice and inhibition of t, can significantly change its original antibody response. Note thymus (thymus) an important lymphoid organ for the body. Closely related to its function and immunity, the secretion of thymic hormones and hormone-like substances, organs with endocrine function. Thymus is the blood-forming organs, can produce lymphocytes and transported to the lymph nodes and spleen, etc.. The body's immune lymphocytes play an important role. (A) tissue transplantation (human tumor xenografts) of Table 4-1 success in human cancer xenograft Number of cases from human samples Lung Cancer 5 Gastric Cancer 5 Cervical 5 grawitz's tumor 5 Melanoma 2 Ovarian Cancer 2 Carcinoma 2 krudenberg's tumor 1 Endometrial tumor 1 1 osteosarcoma Meningioma 1 1 neuroblastoma Liposarcoma 1 Testicular tumor 1 Choriocarcinoma 1 1 rhabdomyosarcoma Number of cases from the tissue culture Lung Cancer Oat cell type 2 Adenocarcinoma type 4 Squamous cell type 1 Melanoma 2 2 giant cell tumor of bone Cervical 1 1 endometrial cancer Endometrial cancer (malignant transformation) 1 Bile duct tumor 1 Breast cancer 1 1 gastric choriocarcinoma 1 neuroblastoma Bone cell tumor 1 Lymphoreticular cell tumor 1 Acute lymphocytic leukemia 1 African cell carcinoma 1 Human tumors transplanted into immune deficient animals, can maintain their biological characteristics, used to study human tumor sensitivity to drugs of great help. Early work is the lack of human tumors transplanted into animals of special parts of the immune function, such as chicken, animals, anterior chamber, hamster buccal capsule and so on, although a certain percentage of survival, but also by the slow growth of tumor capsule into parts restrictions, mass is often small, difficult passages, but can not meet the need more sources of experimental tumor treatment. Threat to human cancer has become one of the most serious common diseases, the number of people die each year from the disease to millions, the establishment of model for the prevention and control research, is the basis for an important topic in medical research. China has started doing this a lot of exploration, has established 18 kinds of nude mice (see Table 4-2). Range from the research point of view, the following six aspects. 1. Human cancer cell lines Detection of carcinogenic Establishment of nude mice. 2. Human tumor xenografts in nude mice and its biological characteristics of the establishment. 3. Invasion and metastasis of human cancer, the mechanism of regulation. 4. Hepatitis B virus vaccine in genetically engineered cell lines highly expressed hbsag carcinogenicity test. 5. Experimental treatment of human cancer research. 6. Etiology of cancer of a carcinogenic chemical carcinogen studies. In these research projects, in addition to human nasopharyngeal cancer transplanted in nude mice has not been successfully established, the remaining are to be successful. Such as intestinal adenoma who Taipei Medical nude mice, nude mice transplanted passage between the survival rate was 100%, with human primary tumor characteristics. And access to the high transfer rate of lung cancer xenografts in nude mice. Another example is the medullary breast tumor cell lines such as carcinogenicity testing and the establishment of carcinoma in nude mice, the success rate of 83.8 to 100%, more than 60% of the international reports. Human malignant tumors transplanted in nude mice has the following characteristics: 1. Still maintain the original transplanted tumor tissue structure or a variety of functions. 2. The organization of the human carcinoma in nude mice transplanted culture, can reproduce in tissue culture of cancer vanished original structure. 3. Almost not found to be transplanted tumor metastasis. These features help to analyze the nature of human tumors. 1. Constant vivo mechanism of immune deficiency, and other rodents are subject to immune measures, the conditions of constancy by individual difference factors. 2. Cancer tumors can be controlled, so that the growth of human tumor transplant well. 3. Inoculation of tumor structure of the structural characteristics of the original tumor, is conducive to tumor cell lines in vitro identification; 4. Of tumor growth in vivo behavior and the process of tumor and host immune relationships between. 5. Complementary in vivo and in vitro studies with observation. 6. Can use its establishment of a stable animal model for drug screening. Tumor cell morphology, chromosome content and isoenzyme levels, like human tumors, indicating no occurrence of the phenomenon of cell _select_ion and cell hybridization, cell kinetics and biochemical characteristics have not changed. 7. Continuous in vivo after inoculation of tumor cells passaged in vitro are also easy to obtain long-term survival, can improve the success rate of training. Therefore, the application of nude mice, Cancer basic research work will make new contributions. (B) tumor of drug treatment and tumor immunity The survival of nude mice inoculated with tumor sensitivity to chemotherapy and clinical findings are similar. To dtic and ccnu melanoma inhibitory effect is stronger than the 5-fu is not valid, with the clinical objective response (three drugs were 20%, 12% and 2.5%) were similar. Human lymphoma xenografts burkitt after cyclophosphamide had a higher sensitivity, but also consistent with the clinical outcome. Other tumors such as breast and colon cancer xenografts, the former adriamycin (5mg/kg) ,5-fu (50 ~ 80mg/kg) and phenylalanine nitrogen mustard (7mg/kg) there is a certain suppression tumor efficacy, the latter a ccno and mitogen-methyl toxins significant effect. Interestingly, p333 is not valid Rokko melamine, but ignored the human lung cancer xenograft effective application of the tolerance dose of 60 ~ 90mg/kg are removing tumor effect on human breast and colon tumor mx-1 tumor cx-1 also effective. Clinical trial the drug re-prove the human lung cancer and lymphoma has therapeutic effects. Recently, the past studies were interrupted due to toxic azo-oxo is leucine, nude mouse tumor model to evaluate the re-employment, proof of the mx-1 and lung lx-1 have significant effects, but also to re-enter clinical studies. Thymidine so close to someone with a tumor in nude mice 444 ~ 888mg/kg 96 ~ 140 hours of continuous perfusion and found that it can inhibit human melanoma and teratoma growth and lead to tumor regression and no significant toxicity to the host, These new results have caused clinical attention. In recent years, the human cancer transplanted into nude mouse renal capsule membrane, the size of tumor growth observed in the tumor diameter measured under a binocular microscope omu, comparing treatment group and control group differences in about 11 days of drug efficacy can be evaluated results. In tumor immunology research, france reported that athymic nude mice with 4 (5) -33-- dimethyl triazole -5 -1 (4) carbon-amine [dic4 (5)-33-dimethyl-1-triazlon inidazole-5 (4) carboxamide] treatment, significantly increased the strain on the l1210 and l3tra immunogenicity of lymphoma. (C) of the immune and genetic studies As the rapid development of modern genetics, have been found more than 40 immunodeficiency diseases and genetic factors. Many reports presents only the clinical manifestations of these diseases, and laboratory test results, the on_set_ mechanism of the Ting Liu in the hypothesis stage, which was mainly due to human suffering is not with the nature of illness are relatively immune deficiency should De spontaneous animal model, can not sick animals to observe the disease and development of the whole process, which can not explain its inheritance. Athymic nude mice with congenital genetic factors, immune animals, defects in the original autopsy findings and indicators as well as other histological features, were associated with human immunodeficiency disease similar to primary cells in immune disease. Because of the strains of nude mice of different genetic background, the performance of the cellular immune response and laboratory indicators also vary. These nude mice to study various human populations immunodeficiency disease pathogenesis and inheritance of an animal model. Genetic scientists have bred animals with different immune defects characteristic of inbred strains of mice more than 50 species. Application of the spontaneous immune deficient mice, the main application is balb / c nude mice genetic background, individual laboratories applied nih, icr and other non-inbred mice. (D) virus, bacteria, parasite infection mechanism T-lymphocytes in athymic nude mice defects, immune function is low, is the study of viral, bacterial and parasitic infection mechanism of the excellent model animals. Can be used to study such as encephalitis sa14-14-zhk7 attenuated strain for the breeding of JE live vaccine strain in normal mice can produce the required immunogenicity (ld50), missing or thymus in the thymus stunted individuals of the immunogenicity of how, for future reference value is used. The results are shown in Table 4-3 to balb / C (+/+) mice as controls. Produced by JEV infection immunity, predominantly cellular immunity, such as the t cell defects in immune function in nude mice and normal mice produced the same level of immunity, immunity must be 40 times greater doses can be achieved. Also shows that there are still remnants of nude mice, t-lymphocytes. It follows that the population in the field have lower antibody levels, the t cell function is defective and should be explored as one of the factors. Nude mice have proven to be of t lymphocyte function impairment, the best model of mycobacterial infection, and its very low rate of spontaneous tumors. (E) Verification of biological products and medicines Biological products (vaccines, vaccine) the immunogenicity of the security is an essential element of the product. It involves products for potential system cancer, infection, virulence factors and whether its atavistic possibilities. Particularly in the application of animal tissue or human diploid cell culture vaccine strains, the detection of these cells to the carcinogenic potential of certain products to be caused by abnormal hair and occurrence mechanism of carcinogenicity of drugs or anti-cancer drugs other aspects of the research, congenital defects of the nude thymus function is a good animal model and experimental means. (Vi) research on the microbiology Only the back of the human M. leprae in the past nine stripes enough armadillo (armadillo) who can grow, and this produced in South America the animals difficult to find, not easy to feed and operations. 1975 colston so will leprae in nude mice inoculated paws, found M. leprae can multiply, spread the body, causing tumor type leprosy. This study of the biological characteristics of M. leprae, immunogenicity, and pathogenesis of leprosy provide a useful experimental model. Another example of choroidal lymphocytic meningitis (lcm) virus by intracerebral inoculation of the virus latent infection in the non-normal mice, can cause meningitis, infection of cells were used as target cells is damaged, the brain and spinal cord occurs a significant cellular immune response, but in t cell defects seen in exactly the opposite of nude mice, did not lead to the death of animals, only persistent viremia, the body does not appear lcm antibodies, nor any immune response. (Vii) the endocrine and old medical application Manual removal of the thymus in animals, most studies suggest that the pituitary gland, thyroid, adrenal, gonads and other abnormalities. Some specific pathogen-free environment in nude mice and normal mice feed research, analysis 3,9,11 weeks old male and female animals, pituitary growth hormone and thyroid, adrenal and gonadal function and found that both There was no statistically significant between the difference. In geriatric research, suggested that there is no t cells in nude mice, can trigger autoimmune phenomena, the skin soluble collagen (collaggen) also decreased, so that the thymus, autoimmunity, aging, there is a relationship between the three. But also there are different arguments. (H) of the domestic application of research carried out in nude mice Briefing 1. nk t and defective cellular immunity - beige nude mice and the basic characteristics of the incubation. 2. Non-inbred 615/pbi-beige/nude preliminary study immune function. 3. t and nk cells co-deficient mice xenografts of human cancer metastasis research. 4. Immune-deficient animals (nude mice) in vivo human tumor growth and metastasis of cancer. 5. Screening abdominal cavity of nude mice with high metastatic human lung adenocarcinoma cells and its biological characteristics. 6. urethane induced balb / c nude mice and lung cancer growth and metastasis in nude mice and the characteristics of the skin. 7. Five human cancer cell lines transplanted in nude mice transfer characteristics of the preliminary study. 8. Human malignant melanoma in nude mice model and pathological observation. 9. Three human lung cancer nude mice model of the form of long-term observation of the passage. 10. Portability of human lung cancer tumors in nude mice Establishment and growth characteristics of plants and fine structure of the observation. 11. Passaged in nude mice and cultured human small cell lung cancer cell lines. 12. Human lung giant cell carcinoma of the pla-801 group and the clones of cell line cells (a, c, d, e) after the spontaneous metastasis in nude mice implanted subcutaneously Characteristics. 13. Human glioma cell lines in nude mice solid tumor model nhg-1 and characteristics of the establishment. 14. Ventricular ependymoma who turn transplanted in nude mice model. 15. Two nude rat model of human hepatocellular carcinoma and biological characteristics of the observation. 16. Human gastric cancer nude mouse transplantation model of its biological characteristics. 17. Human gastric cancer nude mice model. 18.615 people burkitt established in nude mice lymphoma cell lines. 19. Mucus rectal adenoma xenografts in nude mice and passaged strain of the initial summary. 20. Growth kinetics of human hepatocellular carcinoma in nude mice some of the characteristics of a secretion of fetuin. 21. Flow cytometry (flow cytometer) the biological characteristics of nasopharyngeal carcinoma in nude body of the application. 22. External radiation and cisplatin, and mixed bacterial vaccines and more comprehensive treatment of the nude mice model of human liver cancer study. 23. Liver carcinoma model in nude mice application-oriented research. 24. Anti-glioma mcab in human brain glial cancer nude mouse model nhg-1 in the Orientation. 25. Nuclide-oriented merging of high temperature on the radiation treatment of the role of human hepatocellular carcinoma in nude mice. 26. Of lymphocytes into nude mice and b factors discussed. 27. Various organs of nude mice and serum two-dimensional electrophoresis "protein map." 28. Determination of plasma amino acids in nude mice. 29. Three types of brain tumors in nude mice model of human chromosomes preliminary analysis. 30. Application of mycoplasma contamination in cell purification nude preliminary observation. 31. Pathological observation and analysis of nude mice. 32. Human hepatocellular carcinoma in nude mice computer processing of experimental data. 33. Establishment of small spf mice and in laboratory experiments of Clinical Oncology. 34. Employing rapid lung tumor susceptibility testing. 35. Human tumor xenografts in nude mice host serum sialic acid and sialic acid content of glycoproteins. 36. Pingyang toxins and bleomycin a6 on transplanted human liver cancer and stomach cancer inhibition. 37. Human nasopharyngeal carcinoma epithelial cell line model of nude mice. 38. Methods of sterilization feed nude. 39. Nude mice breeding and quality control of the preliminary report. 40. spf mice and the establishment of animal breeding room application. 41. Nude nude rooms establishment and breeding. 42. breeding nc nude mice with human brain tumor transplantation. 43. Immunosuppressed mice model and human colon cancer cell line xenograft hrt-18 study. 44. Human tumor cell lines transplanted in nude mice comprehensive study. 45. Human tumor transplanted into nude mice model. 46. Athymic nude mice in the study of skin diseases.
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Breeding and feeding conditions in nude mice
(A) Reproduction Do not currently breeding mice nu / nu female mice, because of their low reproductive performance, the general mating heterozygous or homozygous recessive heterozygous male and female mating. This mating method, the phenotype of their offspring will appear normal and nude mouse pups, the ratio of 1:1. Nu gene will generally be breeding into c57bl/10 mice. In the gene into the homologous (cogenic) strains, generally with the female and male c57bl/10 c57bl/10-nu (outbred strain) cross. The mating method and results are as follows: Beijing drugs test by breeding mice with the rodent species is balb / c-nu / nu, Department introduced from Denmark in 1973, experimental animal study in central Japan. Continue to develop after three years of production by Japanese clea Corporation. Introduced in 1980 by clea. Male athymic nude mice is (balb / c-nu / nu), females are heterozygous thymus in mice (balb / c-nu / +). By balb / c-nu / + ♀ and balb / c-nu / nu ♂ random mating for breeding, has achieved good results, good performance of nude mice: pregnancy rate 81.5%, the average birth rate 8.1 / Wo, the average production rate of 3.99 bare Aberdeen / Wo, Wo pups survived an average of 3.62, 9 weeks old 100% survival rate of offspring, the main project data with the Japan Institute of Experimental Animals (clea) and the British Laboratory Animal Center (lac) consistent with published material. (B) of the feed conditions Because of the lack of t cells in nude mice, susceptible to bacterial, viral and fungal infection of the damage, such as by way of conventional animal breeding, only a few mice survive more than a month, no more than four months, and on the isolator (isolator) in the feed can survive for more than one year. Therefore, the life of nude mice and feed hygiene conditions are closely related. Usually multiply first in the isolator. Then put into a specific pathogen-free barrier environment in the feed. Pathogen-free conditions in animal feed need to install a barrier between the outside world, the more serious barrier, the more feed to ensure the health of nude mice, however, if not pay attention to choose the type of barrier, its effect is not guaranteed, and should continue to check eligibility. 1. Pathogen-free conditions, equipment, feed nude ⑴ air filtration devices with a sealed plastic cage. Since each cage as a unit. It includes a standard clear plastic cages, cages covered with filter material coated with the air. The latter close to the cage for several weeks at the wound with tape to seal. Then, the cage can be placed in the general standard laboratory cage rack. Flaky filter material, spun by a sparse (but not textiles) polyester fiber. It should be able to prevent microorganisms from outside the cage into the cage. A full _set_ of cages were sterilized by high pressure steam. Use it and feeding management (such as adding water and feed, clean cages, weaning, etc.), must be conducted in a protective cover. Cover some positive pressure filtered air contained within. But also a laminar flow (no turbulence), one-way. The above mode of operation is kept by a pathogen-free animals, raising the easiest way. ⑵ animal isolators. The most commonly used with this device by the flexible sheet of transparent vinyl plastic, but may be glass, stainless steel, aluminum, leather and nylon and other materials to make. Commercial products have a certain size, can also be specifically designed according to the size needed, which is a sterile life of a small room, which can eliminate any microorganisms. Room air is filtered out of the device. All food and supplies have been sterilized, and then by a sterile inside the entrance into the small room, you can exclude any microorganisms. Initially, the use of chemical agents and high-pressure steam sterilization for sterilization of the device. In a sterile environment, the same genetic background of nude mice and the normal life span in mice heterozygous similar type. However, poiley's et al (1974) found that in this environment, the survival rate of newborn mice, than in the general environment is low. In order to make them closer to the gastrointestinal tract functions normally, it was proposed to the sterile environment of the nude mice inoculated with a non-pathogenic bacteria (poliey's, etc., 1974; eaton, etc., 1975). This can often play a role in improving reproductive performance, and help the sterile mice were transferred from the isolator to the existence of poor conditions to keep the device. The most effective control environment in order to try to save the sterile (or with a certain bacteria) nude mice, isolation is the ideal storage support equipment. But it also has shortcomings, this is the cost of labor, to a certain space, a limited number of breeding animals. ⑶ laminar air flow device. It includes a standard small room, covered hood and grid. Each _set_ of apparatus to form an independent environment, and indoor ventilation system independent. Its own input filter the air, the clean air satisfactorily into the cage, and columnar discharge. As each _set_ of apparatus independent of each other, but also positive pressure air protection, so I can put them under normal conditions. They are portable, both for maintenance, but also maximize the use of premises and equipment. Success using this method depends on the management of good or bad. AV closely monitor the movement of pollution and, except for full-time staff burglary. Should be positive, one-way air flow conditions, maintenance cage food, contact with all the items mice (feed and other items) must be sterilized. Drinking water must be treated to remove bacteria, full-time workers must wear sterile surgical masks, hats, gloves and clothing after a long, touching animals, to be a rubber bag with a tip of the forceps, and must be denatured ethanol (to put it aside) of immersion. ⑷ laminar air flow room. Different from the place in a room above a small air laminar flow device, but the entire room for the positive pressure filtered air environment are shrouded. Design, must be fitted with air into the switch, air inlet to be installed indicator. Staff in the room wear described above. Indoor applications of feed, bedding and cage sterilization, to be used at both ends of a switched high-pressure steam sterilizer. Method can be introduced in order to maximize the use of premises breeding animals. Although funding for the installation of such expensive room, but the laminar air flow room with access strictly limited staff, can ensure the smooth growth of nude mice produced, it is the large number of breeding the best way to nude mice. For example, the use of it, the past five years (1973 ~ 1977), Cancer Research Center in frederick The average annual production of more than 20,000 nude mice. 2. Environmental Control ⑴ temperature. Nude mice for room temperature 26 ~ 28 ℃ (78 ~ 820f), naked hairless mice, the mice lost body temperature faster than a hair. In a continuous laminar flow of air, they heat faster and take about 28 ℃ (800f) at room temperature to be compensated. Room temperature control in general feed 25 ℃ ± 1 ℃ can. If there is hair in nude mice and heterozygous mice when the same cages can be slightly below room temperature. Feed in the chamber in a continuous laminar flow of air need to be nude in a laminar flow room temperature up to 28 ℃. ⑵ humidity. Relative humidity should be maintained at 40 ~ 60%, this time, water loss adult nude mouse skin at least. Humidity is too low, the survival of newborn mice negative, which in the laminar air flow environment is particularly important. ⑶ ventilation. Generally believed that the need for ventilation per hour 10 to 15 times, use high efficiency filter (99.9%) to ensure good air filtration, air divisible particles larger than 0.3μm. Exports also filter the air (you can also use the performance on the lower) to prevent backflow of air pollution when, and how the first design is from the outdoor maintenance of these filters. In the laminar air flow room, the air pressure at least 0.65cmh2o. And speed the flow of air evenly and freedom to control. Continuously passing the air filter cage, the torrent in animal environment, the theory is a barrier to prevent exogenous contamination. ⑷ light. Should be maintained 10 hours a day light, no light and dark cycle of 14 hours. Without windows, using artificial lighting, so that constant illumination throughout the year, but should avoid too strong fluorescent light. 3. Cages and bedding Foster nude mice cages, cage bottom area should be 97 square centimeters (15 square inches), height should be 12.7 cm (5 inches), should be _select_ed to withstand high-pressure steam sterilization of plastic or stainless steel. Its shape should be easy to overlap, to facilitate the sterilization and storage. Transparent plastic cage is better, do not have to open the cage with a lid will observe the animals. The end of the cage to put a litter, which can not network. Cage must be cleaned once a week, or, as the need to address to ensure that the environment clean and dry. With detergents or other detergents to clean the cage or other items after, must be fully clean. Otherwise, it will stimulate the skin of nude mice. Bedding nude mouse skin in direct contact, not irritating. Can be used without the dust and sharp pieces of hard wood, grinding off of corn, or pine shavings. Must be sterilized before use, and do not form a massive sterilized before use. Nude mice can be used to build the nest of cotton or tissue paper. However, if there is an inch thick padding, and room temperature control just right, can make mice infected with comfortable, generally do not need a pad of cotton or tissue paper. 4. For food and water supply ⑴ feeding. The nutritional needs of nude mice with other strains of mice similar. Therefore, any commercial feed can be used. Food must be sterile, single-layer can be paved after the food or placed on a small plate with a hole in your pocket, high-pressure steam sterilization (45 min, 120 ℃). Before sterilization without heat to increase the amount of nutrients (williams's, etc., 1968). In addition, you can add whole wheat bread and milk to improve the fertility of replication and prevent the recurrence of the phenomenon of macrophage food (poiley's, etc., 1974). Through the drinking water supply of antibiotics to eliminate bacteria in the gastrointestinal tract (van der waaij's, 1966). And, this is a prevention of nude mice under the control of the stringent environmental pollution that may occur outside the additional measures. We use the four formulations is shown in Table 4-4. The following few gastrointestinal absorption of antibiotics, each formula should be changed once a week, rotating once every four weeks, can reduce the emergence of resistant strains. If you start in a strictly controlled environment, sterile nude mice breeding, you also need to use antibiotics, because of the additional use of antibiotics in breeding the possibility of technical errors also increased. 5. The maintenance of laminar air flow room Laminar flow room from floor to ceiling, and equipment required to keep clean and not broken. Monthly sterile indoor conditions must be detected, put a plate per square meter to check the number of bacteria in indoor air. Check the provisions of bacteria down in different countries, The table below Table 4-5 States laminar flow room down the limits of the provisions of bacteria Unit provides a medium level exposure time (minutes) incubation time, temperature, strain the limits fall Japanese general agar 5 '37 ℃ 48hr <5 个 U.S. blood agar 10 '"<3 Test the blood agar Beijing 30 '"<10 In addition to falling outside the limits shall not exceed the number of bacteria and pathogens can not have there, otherwise, need to re-disinfection. All the best portable high-pressure sterilization of equipment, non-mobile devices (such as walls, floors, ceilings, etc.) to use liquid phenolic disinfectant thorough cleansing and disinfection should be repeated three times. After disinfection, the room should be sealed, made after 48 hours of detection of microbiological contamination, such as the detection is negative, will be allowed to use. Staff must wear a full _set_ into the surgical sterilization and disinfection of boots clothing. In short, should be nude all the requirements of production, or testing is not easy to be successful. Feed breeding mice must pay attention: ⑴ barrier system is the feed to establish an important condition for breeding mice. Congenital absence of the thymus in nude mice, the immune system is not perfect, the lack of resistance against external factors, vulnerable to infection of pathogens, in the conventional environment, can only survive a few months, therefore, must be in the absence of pathogen isolation environment feed feed . According to the present reality, yet can not build more of the high standards of animal testing facilities, and renovation of existing buildings approach is feasible. After the conversion, although the barrier breeding room and technology is relatively simple compared to developed countries, but basically reached the requirements of the barrier system facilities, costs greatly reduced, but also can work normally in nude mice breeding. ⑶ pups born alive or not, the key is breast-feeding, such as the lactating nude lactating not pay attention to a high mortality rate. The main reason is breastfeeding a Soke littermates homozygous offspring development of fast, large body of robust, competitive, and homozygous affected breast nude fought over the development of homozygous nude mice, resulting in the wasting death. In order to improve growth rate and survival rate of nude mice, nude mice with homozygous, heterozygous offspring were breast-feeding, and female mice fed high-protein, high vitamin diet. ⑷ order to maintain the normal breeding longer-term growth of microbiological monitoring methods must be established to control quality. Immune function due to defects in nude mice, susceptible to microbial, viral and parasitic infections, particularly vulnerable to hepatitis virus infection in mice, but mice infected with a mouse hepatitis, with the mice will nest after birth, 36 ~ 134 days have been killed and spared. Disease-like changes in rat liver in marble, quality hard, yellow, roughness, nodules, uneven edges. Reproduction in nude mice feed a big threat. Feed in the nude, often prone to so-called "wasting syndrome" (wasting syndrome), one of the real and the nude mouse common viral infection is closely related to the virus by Caesarean section to avoid infection. Inspection method using micro-organisms, to consider the physical characteristics of nude mice, nude mice are immune deficient animals, murine hepatitis virus, Sendai virus infection, the serum does not produce antibodies. Therefore, the only check hybrid offspring with fetal serum antibodies situation, or direct separation of pathogens, or liver tissue of nude mice inoculated after the hybrid offspring, and then determined the corresponding serum antibodies. Therefore, nude mice and the number of pathogenic viruses and other pathogens in Taiwan Ze's inspection method, mainly to check heterozygous mice with fetal serum antibody production conditions to determine whether mice infected by these pathogens.
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Characteristics and application of naked rats
无胸腺裸鼠 裸大鼠的特性及应用
Nude rat is the first with the British Institute of Aberdeen rowett discovered in 1953, the gene symbol for the rnu,. Because of difficult feeding, only last until the early 1960s. 1975 again found homozygous nude rats (rnu / run). February 1977 at the Experimental Animal Center of the United Kingdom mrc nude rats was established seed group. Festing the first time in 1978, a detailed description of the nude rats, and reported human tumor xenograft nude rat. Rnu nude rats were then introduced into Europe and the United States and Japan. Introduced into China in 1983. May 1976 in New Zealand Victoria University found that rats exposed to another strain, 1979, a detailed report by the mcneilage. In order to distinguish and rnu nude rats, the gene symbol named nznu. Rnu nude rats due to a wide range of applications, so the vast majority of data from rnu nude rats. Congenital athymic nude mice using established animal model of human cancer is a major progress in tumor models. These models have been widely used in various studies. Nude rats and human cancer xenograft that success to the tumor and the immune workers added a new tool. Because instead of nude mice to nude rats, with a large tumor, take blood and more feasible in some minor surgery, etc., so there than in nude mice with a certain superiority. (A) the characteristics of nude rats 2. Characteristics of immune function ⑴ t cell function: Congenital absence of the thymus, the lack of t cell, t cell function was a loss. Skin transplantation, in the heterozygous group, the same kind of skin graft rejection in about 10 days, but in the rnu nude rats, homogeneous or heterogeneous growth of the skin graft up to 3 to 4 months or more. Of delayed hypersensitivity, rnu nude rats no positive tuberculin delayed-type hypersensitivity. With tetanus toxoid and ovalbumin immunization, rnu nude rats were not detected in blood igm and igg antibodies; and in rat serum heterozygote can measure the normal titer of tetanus toxin antibodies. On t cell mitogen (PHA, Con A and pokeweed) and lymphocyte transformation test was negative. ⑵ b cell function: Generally speaking b cell function is normal. brooks, etc., and with anti-ig antibody anti-t cell rnu / rnu and rnu / + rat spleen and lymph node cell line immunofluorescence staining was found in rnu nude rats, ig + marked increase in the proportion of cells and naked cells, and most of ig + labeled cells is considered to be b lymphocytes. Rnu nude rats and determination of phenotype of normal rats (rnu / + or + / +) on the colon bacteria lps village of igm antibody titers and found no significant difference. B cells in vitro by mitogen stimulation of Staphylococcus aureus rnu / rnu and rnu / + rat spleen cells, but also no difference in uptake of thymidine capacity. ⑶ nk cell function: nk cell activity increased. de jong report nk cell activity in rats exposed control group. In the mesenteric lymph nodes, rnu nude rats than in heterozygous nk activity (rnu / +) up to 10 times. lotzovd this work are summarized as follows: nude rats can be measured and nk cell activity; in the peritoneal exudate, nk cells, the highest activity, the lower peripheral blood and spleen, bone marrow cell viability without nk; nude rats nk cell viability higher than the rat thymus; less than 3 weeks of age were not measured and nk cell activity; interferon inducer abpp nk cell activity can improve; mediated cytotoxic effector cells to survive in rich lgl section; nk viability of strengthening the level of interferon. 3. Other Features ⑴ sparse body hair: naked nude mice and rats is not as complete as the hairless, but sparse body hair, and sometimes completely disappear temporarily, and later reproduce. Older male nude rats root of the tail is often hairy. ⑵ relatively slow growth: the same with the nude mice, rnu nude rat development is relatively slow. The weight is only about 70% of normal rats. ⑶ breeding capacity of female rats is low: and as nude mice, female rats exposed during pregnancy no breast development, breast milk due to lack of offspring, died soon after birth. So bare rat breeding, are still using male mice homozygous (rnu / rnu) and heterozygous female rats (rnu / +) Traditional method of mating. Homozygous newborn pups and heterozygous in the identification, mainly as far as the number of tentacles. Weaned pups 4 weeks, 3 months after birth can be used to mate. Free naked male rats to 7 months old, half-naked female rats (rnu / +) available to more than a year. In a clean environment, the life of nude rats can live up to the 1 to 1.5 years. (B) the application of nude rats Nude rats currently used in transplantation of human cancer. Athymic nude rats due to the lack of t cells, and it could be successfully transplanted xenogeneic skin and xenograft tumors, including mouse tumors and human tumors. festing the first report of the nude rat xenograft tumor xenografts (human colon and mouse plasma cell tumor), but subsided spontaneously after tumor growth. Thereafter, to meet the relevant lines and surgical specimens of human cancer transplanted into nude rats were reported. Transplanted nude rats were the most common skin cancer pathway, but also useful for kidney, muscle brain were. Can be grown in nude rats transplanted with human melanoma tumors, malignant glioma, and colon, pancreas, lung, breast, kidney, prostate, vulva, cervix and other cancer. Most of cancer after transplantation, showing self-limiting, only a few tumors showed progressive growth. colston report 9 cases of human cancer cell lines, 7 were successful transplant, only one case showed progressive growth of melanoma without spontaneous regression. stragand report two cases of successful transplantation of human colon cancer cell lines, but only lovo cell lines showed progressive growth; while the other strains sw620 after transplantation, 90% of the nude rat shows spontaneous regression of tumor. williams transplantation of 5 cases of human urinary and reproductive system cancer cell lines in nude rats, three successful, only one kidney was no spontaneous regression. The reasons for spontaneous regression is not very clear, suggesting that rats with bare t cell-mediated immune function, particularly strong on nk cell activity. But there are of the view that the reasons for spontaneous regression and _select_ion of the possible naked older rats, whereas the _select_ion of nude rats 4 weeks old the young can increase the success rate of transplantation. Liver Cancer Institute, Zhongshan Hospital, China recently successfully established a bare room rat and human liver cancer model ltnr1 ltnr2, this is the bare human hepatocellular carcinoma model in rats was first reported. They also made a nude rat human tumor transplantation on the study reported. Refer to Chapter IV literature book. ltnr1 and ltnr2 were drawn from the nude mice model of human hepatocellular carcinoma ltnm4 and ltnm3. The average age of rats exposed rats was 31.5 (9 ~ 49) days, by subcutaneous way. Afp testing by pathology and confirmed the success nude rats with human hepatocellular carcinoma, has been passed 14 generations and 5 generations. Two models are with the following characteristics: ① retained the morphological and functional characteristics of liver cancer Yuanren, ltnr1 and ltnr2 are such differentiation (Ⅱ - Ⅲ level) of hepatocellular carcinoma. afp ltnr1 the higher concentration, with a median concentration of 8000ng/ml: ltnr2 low, less than 125ng/ml. ② preserved human liver cancer model in nude mice and ltnr3 ltnm4 some advantages: TRANSPLANTED high success rate, ltnr1 and ltnr2 were 100% (65/65) and 87.5% (14/16); spontaneous regression rate is low, 3.1% (2 / 65) and 0 (0 / 14); incubation period is short, 12.7 ± 3.9 days and 17.0 ± 6.2 days; rapid tumor growth, the average weekly increase of almost average diameter 9.1 ± 2.7mm and 8.8 ± 3.4mm. ③ produced tumors with a large amount of blood taken more than a minor operation to facilitate the implementation of some of the advantages of surgery. Currently, these models have been carried out to explore the application of tumor markers, the positive scan and trial experimental treatment studies, and achieved initial positive results. Nude rat model of human liver cancer, liver cancer is not only beneficial to people, and to various human tumor transplantation has brought new hope. Nude rat model of human cancer, nude mice can compensate for certain deficiencies in human cancer model, to better promote the progress of cancer research.
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Characteristics and application of naked rats
无胸腺裸鼠 裸大鼠的特性及应用
无胸腺裸鼠 裸大鼠的特性及应用
Nude rats Aberdeen Rowett Research Institute is the first with the British in 1953 discovered the gene symbol for the rnu,. Because of difficult feeding, only last until the early 1960s. 1975 again found homozygous nude rats (rnu / run). February 1977 MRC Laboratory Animal Centre in the UK established a group of naked seeds in rats. Festing 1978, the first detailed description of the nude rats, and reported human tumor xenograft nude rat. Rnu nude rats were then introduced into Europe and the United States and Japan. Introduced into China in 1983. May 1976 in New Zealand Victoria University found that rats exposed to another strain, 1979, a detailed report by the Mcneilage. In order to distinguish and rnu nude rats, the gene symbol named nznu. Rnu nude rats due to a wide range of applications, so the vast majority of data from rnu nude rats. Congenital athymic nude mice using established animal model of human cancer is a major progress in tumor models. These models have been widely used in various studies. Nude rats and human cancer xenograft that success to the tumor and the immune workers added a new tool. Because instead of nude mice to nude rats, with a large tumor, take blood and more feasible in some minor surgery, etc., so there than in nude mice with a certain superiority. (A) the characteristics of nude rats 2. Characteristics of immune function ⑴ T cell function: Congenital absence of the thymus, the lack of T cells, T cell function was a loss. Skin transplantation, in the heterozygous group, the same kind of skin graft rejection in about 10 days, but in the rnu nude rats, homogeneous or heterogeneous growth of the skin graft up to 3 to 4 months or more. Of delayed hypersensitivity, rnu nude rats no positive tuberculin delayed-type hypersensitivity. With tetanus toxoid and ovalbumin immunization, rnu nude rat serum IgM and IgG failed to detect antibodies; and in rat serum heterozygote can measure the normal titer of tetanus toxin antibodies. On the T cell mitogen (PHA, Con A and pokeweed) and lymphocyte transformation test was negative. ⑵ B cell function: General, said B cell function is normal. Brooks and other anti-Ig with anti-T cell antibodies and rnu / rnu and rnu / + rat spleen and lymph node cell line immunofluorescence staining was found in rnu nude rats, Ig + cells and marked increase in the proportion of bare cells, and most of Ig + labeled cells is considered to be B lymphocytes. Rnu nude rats and determination of phenotype of normal rats (rnu / + or + / +) on the colon bacteria the village of IgM LPS antibody titers and found no significant difference. B cells in vitro by mitogen stimulation of Staphylococcus aureus rnu / rnu and rnu / + rat spleen cells, but also no difference in uptake of thymidine capacity. ⑶ NK cell function: NK cell activity increased. De Jong reported that NK cell activity in rats exposed control group. In the mesenteric lymph nodes, rnu nude rat NK activity than heterozygous (rnu / +) up to 10 times. Lotzovd this work are summarized as follows: nude rats can be measured and the NK cell activity; exudate in the abdominal cavity, NK cells, the highest activity, the lower peripheral blood and spleen, bone marrow without NK cell activity; nude rat NK cell viability higher than the rat thymus; less than 3 weeks of age and have failed to measure NK cell activity; interferon inducer ABPP can increase NK cell activity; mediated cytotoxic effector cells to stay in the LGL-rich part; NK viability of strengthening the level of interferon. 3. Other Features ⑴ sparse body hair: naked nude mice and rats is not as complete as the hairless, but sparse body hair, and sometimes completely disappear temporarily, and later reproduce. Older male nude rats root of the tail is often hairy. ⑵ relatively slow growth: the same with the nude mice, rnu nude rat development is relatively slow. The weight is only about 70% of normal rats. ⑶ breeding capacity of female rats is low: and as nude mice, female rats exposed during pregnancy no breast development, breast milk due to lack of offspring, died soon after birth. So bare rat breeding, are still using male mice homozygous (rnu / rnu) and heterozygous female rats (rnu / +) Traditional method of mating. Homozygous newborn pups and heterozygous in the identification, mainly as far as the number of tentacles. Weaned pups 4 weeks, 3 months after birth can be used to mate. Free naked male rats to 7 months old, half-naked female rats (rnu / +) available to more than a year. In a clean environment, the life of nude rats can live up to the 1 to 1.5 years. ⑷ susceptible to respiratory illnesses: a result of athymic nude mice, immunity, susceptibility to various diseases. Susceptible to mouse hepatitis in nude mice, and nude rats susceptible to ulcerative purulent tracheal bronchitis and bronchial pneumonia. The etiology may be related to Sendai virus infection. Drinking water by adding tetracycline to control nude rats with respiratory tract infections have a demonstrable effect, so that longer life, for instance with tetracycline 200 ~ 800mg / L, the average life span extended from the 116.8 days to 157.2 days. (B) the application of nude rats Nude rats currently used in transplantation of human cancer. Athymic nude rats due to the lack of T cells, and it could be successfully transplanted xenogeneic skin and xenograft tumors, including mouse tumors and human tumors. Festing nude rat xenograft first reported tumor xenografts (human colon and mouse plasma cell tumor), but subsided spontaneously after tumor growth. Thereafter, to meet on human cancer cell lines and surgical specimens transplanted into nude rats were reported. Transplanted nude rats were the most common skin cancer pathway, but also useful for kidney, muscle brain were. Can be grown in nude rats transplanted with human melanoma tumors, malignant glioma, and colon, pancreas, lung, breast, kidney, prostate, vulva, cervix and other cancer. Most of cancer after transplantation, showing self-limiting, only a few tumors showed progressive growth. Colston report 9 cases of human cancer cell lines, 7 were successful transplant, only one case showed progressive growth of melanoma without spontaneous regression. Stragand report two cases of successful transplantation of human colon cancer cell lines, but only the Lovo cell line showed progressive growth; while the other strains SW620 after transplantation, 90% of the nude rat shows spontaneous regression of tumor. Williams transplantation of 5 cases of human urinary and reproductive system cancer cell lines in nude rats, three successful, only one kidney was no spontaneous regression. The reasons for spontaneous regression is not very clear, suggesting that rats with the naked T cell-mediated immune function, particularly NK cell activity is strong on. But there are of the view that the reasons for spontaneous regression and _select_ion of the possible naked older rats, whereas the _select_ion of nude rats 4 weeks old the young can increase the success rate of transplantation. Liver Cancer Institute, Zhongshan Hospital, China recently successfully established a bare room rat and human liver cancer model LTNR1 LTNR2, this is the bare human hepatocellular carcinoma model in rats was first reported. They also made a nude rat human tumor transplantation on the study reported. Refer to Chapter IV literature book. LTNR1 and LTNR2 were drawn from the nude mice model of human hepatocellular carcinoma LTNM4 and LTNM3. The average age of rats exposed rats was 31.5 (9 ~ 49) days, by subcutaneous way. Pathology and detection by AFP confirmed that nude rats with human liver transplantation, has been passed 14 generations and 5 generations. Two models are with the following characteristics: ① retained the morphological and functional characteristics of liver cancer Yuanren, LTNR1 and LTNR2 are such differentiation (Ⅱ - Ⅲ level) of hepatocellular carcinoma. LTNR1 the AFP concentration was higher, with a median concentration of 8000ng/ml: LTNR2 low, less than 125ng/ml. ② preserved human liver cancer model in nude mice and LTNR3 LTNM4 some advantages: TRANSPLANTED high success rate, LTNR1 and LTNR2 were 100% (65/65) and 87.5% (14/16); spontaneous regression rate is low, 3.1% (2 / 65) and 0 (0 / 14); incubation period is short, 12.7 ± 3.9 days and 17.0 ± 6.2 days; rapid tumor growth, the average weekly increase of almost average diameter 9.1 ± 2.7mm and 8.8 ± 3.4mm. ③ produced tumors with a large amount of blood taken more than a minor operation to facilitate the implementation of some of the advantages of surgery. Currently, these models have been carried out to explore the application of tumor markers, the positive scan and trial experimental treatment studies, and achieved initial positive results. Nude rat model of human liver cancer, liver cancer is not only beneficial to people, and to various human tumor transplantation has brought new hope. Nude rat model of human cancer, nude mice can compensate for certain deficiencies in human cancer model, to better promote the progress of cancer research. Nude mice with human immune system similar, including B cells and T cells, which Bc is the humoral immune cells from the bone marrow; Tc cells are immune cells from the thymus. Significance of athymic nude mice studies is that individuals without antibodies against viruses and cancer treatment mechanism, the development of human medicine and science play an important contribution.
