RESUMEN
Introductions: Hepatic cirrhosis is a final common pathway of all chronic liver diseases, characterized by deposit of fibrillar collagen and liver failure. Materials and Methods: In this experiment, hepatic cirrhosis was induced in 15 female Wistar rats by a 14-week period, with thioacetamide solution in a 200 mg/kg dosage, via intraperitoneal. Animals were submitted to liver biopsy, and euthanized after a 80-day post-induction period. Serum biochemical analysis was performed, in addition to histopathology by H.E., Picrosirius, Alcian Blue and P.A.S. stainings, following analysis of histological activity index and staging of fibrosis. Morphometric analysis of collagen on Picrosirius slides was also performed. Results: Mortality during experimental period was low (13.33%), and after 80-day period, liver function improved, cellular changes did not altered, and deposition of acidic mucopolysaccharides and glycogen were increased. Liver histological activity did not change significantly (7.25 ± 1.30 to 6.41 ± 1.32), but staging of fibrosis was altered (3.91 ± 0.76 to 4.70 ± 1.11). Interlobular collagen showed a significant decrease (5.14 ± 2.00 to 4.00 ± 1.20), while intralobular collagen was increased (0.23 ± 0.06 to 0.36 ± 0.08). Conclusions: These findings characterize thioacetamide as a safe experimental model for induction cirrhosis, which may be used for future therapy studies.(AU)
Asunto(s)
Animales , Ratas , Tioacetamida/administración & dosificación , Colágeno/análisis , Modelos Animales de Enfermedad , Cirrosis Hepática/inducido químicamente , Ratas Wistar , Insuficiencia HepáticaRESUMEN
A five-year-old male Cocker Spaniel was presented for evaluation of the right eye due to discomfort, abundant purulent discharge and progressive enlargement of the eyeball. The owner revealed that the right eye has appeared to be inflamed and smaller then the left eye for years. Ophthalmic examination revealed corneal perforation, buphthalmia and conjuctival hyperemia. Enucleating was performed due to signs of endophthalmitis and ocular discomfort. Histopathology revealed a multilobulated proliferation of chondrocytes producing hyaline cartilage with occasional pleomorphism and binucleate cells. A diagnosis of primary intraocular chondrosarcoma was done.
Foi atendido um cão, da raça Cocker Spaniel, de cinco anos de idade, com desconforto ocular, secreção purulenta abundante e aumento progressivo do bulbo ocular. Ao exame oftálmico, evidenciaram-se perfuração corneana, buftalmia e hiperemia conjuntival. Foi realizada enucleação em decorrência do desconforto ocular intenso e dos sinais de endoftalmite. Exame histopatológico revelou proliferação multilobulada de condrócitos produzindo cartilagem hialina com pleomorfismo ocasional e células binucleadas. Foi diagnosticado condrossarcoma intraocular primário.
Asunto(s)
Animales , Perros , Condrosarcoma/patología , Neoplasias/patología , Ojo/anatomía & histología , Perros/clasificaciónRESUMEN
The combined treatment with histone deacetylase inhibitors (HDACi) and retinoids has been suggested as a potential epigenetic strategy for the control of cancer. In the present study, we investigated the effects of treatment with butyrate, a dietary HDACi, combined with vitamin A on MCF-7 human breast cancer cells. Cell proliferation was evaluated by the crystal violet staining method. MCF-7 cells were plated at 5 x 10(4) cells/mL and treated with butyrate (1 mM) alone or combined with vitamin A (10 µM) for 24 to 120 h. Cell proliferation inhibition was 34, 10 and 46% following treatment with butyrate, vitamin A and their combination, respectively, suggesting that vitamin A potentiated the inhibitory activities of butyrate. Furthermore, exposure to this short-chain fatty acid increased the level of histone H3K9 acetylation by 9.5-fold (Western blot), but not of H4K16, and increased the expression levels of p21WAF1 by 2.7-fold (Western blot) and of RARβ by 2.0-fold (quantitative real-time PCR). Our data show that RARβ may represent a molecular target for butyrate in breast cancer cells. Due to its effectiveness as a dietary HDACi, butyrate should be considered for use in combinatorial strategies with more active retinoids, especially in breast cancers in which RARβ is epigenetically altered.
Asunto(s)
Femenino , Humanos , Anticarcinógenos/farmacología , Neoplasias de la Mama/patología , Butiratos/farmacología , Proliferación Celular/efectos de los fármacos , Metilación de ADN/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Vitamina A/farmacología , Anticarcinógenos/administración & dosificación , Butiratos/administración & dosificación , Inhibidores de Histona Desacetilasas/administración & dosificación , Vitamina A/administración & dosificaciónRESUMEN
Foram avaliados dois protocolos de administração, em ratos sadios, de uma solução de fatores hepatotróficos (FH), composta por aminoácidos, vitaminas, sais minerais, glicose, insulina, glucagon e triiodotironina (T3). A solução foi administrada durante 10 dias, 40mg/kg/dia, i.p., em duas, grupo 2xFH (n=15), ou três doses, grupo 3xFH (n=15), diárias. Foram observados os efeitos na proliferação celular dos hepatócitos, na angiogênese e na matriz extracelular hepática, assim como as possíveis reações adversas. Os animais dos grupos 2xFH e 3xFH apresentaram aumento da massa hepática de 30,1 por cento e 22,5 por cento, respectivamente, em relação ao grupo-controle (CT; n=15). O índice de proliferação hepatocelular foi maior nos grupos 2xFH (1,4 por cento) e 3xFH (1,2 por cento) em relação ao grupo CT (0,53 por cento), e a densitometria relativa do fator de crescimento do endotélio vascular pelo imunoblot não revelou diferença estatística entre os três grupos. Nos grupos 2xFH e 3xFH, houve redução do colágeno intersticial em relação ao grupo CT. A solução de FH estimulou o crescimento hepático e reduziu o volume de colágeno perissinusoidal. A administração em três doses diárias resultou em mortalidade de 26,7 por cento, possivelmente pelo excessivo estresse da manipulação e pela menor adaptação fisiológica dos ratos, o que não ocorreu nos grupos 2xFH e CT. Para esse tipo de abordagem em ratos, o procedimento experimental mais apropriado, seguro, com melhor chance de adaptação dos animais e com resultados significativos é a aplicação dos FH em duas doses diárias.
Two protocols of hepatotrophic factors (HF) administration, in solution composed by aminoacids, vitamins, mineral salts, glucose, insulin, glucagon, and triiodothyronine were evaluated in healthy rats. This solution was administered for 10 days, (40mg/kg/day) i.p., in two (group 2xFH; n=15) or three daily doses (group 3xFH n=15). The effects on hepatocytes cell proliferation, angiogenesis, and hepatic extracellular matrix, and also possible adverse reactions were analyzed. Animals of groups 2xFH and 3xFH presented an increase in hepatic mass of 30.1 percent and 22.5 percent, respectively, when compared rats of control group (CT; n=15). Hepatocellular proliferation index was higher in rats of groups 2xFH (1.4 percent) and 3xFH (1.2 percent) when compared to CT group animals (0.53 percent), and the relative densitometry of the vascular endothelial growth factor analyzed with immunoblot did not show a significant difference among the three groups. Rats of groups 2xFH and 3xFH showed a reduction of interstitial collagen when compared to CT rats. HF solution stimulated hepatic growth and reduced the volume of perisinusoidal collagen. Administration in three daily doses resulted in 26.7 percent mortality, possibly due to excessive stress from manipulation and lower physiological adaptation of rats, which did not occur in rats of groups 2xFH and CT. The more appropriate and safer experimental procedure for this approach in rats with higher chance of animal adaptation and significant results is the application of HF in two daily doses.
Asunto(s)
Animales , Ratas , Hígado , Nutrición Parenteral/veterinaria , Suplementos Dietéticos/efectos adversos , Colágeno/análisis , Hígado/anatomía & histología , Proliferación Celular , RatasRESUMEN
Nutritional substances associated to some hormones enhance liver regeneration when injected intraperitoneally, being denominated hepatotrophic factors (HF). Here we verified if a solution of HF (glucose, vitamins, salts, amino acids, glucagon, insulin, and triiodothyronine) can revert liver cirrhosis and how some extracellular matrices are affected. Cirrhosis was induced for 14 weeks in 45 female Wistar rats (200 mg) by intraperitoneal injections of thioacetamide (200 mg/kg). Twenty-five rats received intraperitoneal HF twice a day for 10 days (40 mL·kg-1·day-1) and 20 rats received physiological saline. Fifteen rats were used as control. The HF applied to cirrhotic rats significantly: a) reduced the relative mRNA expression of the genes: Col-α1 (-53 percent), TIMP-1 (-31.7 percent), TGF-β1 (-57.7 percent), and MMP-2 (-41.6 percent), whereas Plau mRNA remained unchanged; b) reduced GGT (-43.1 percent), ALT (-17.6 percent), and AST (-12.2 percent) serum levels; c) increased liver weight (11.3 percent), and reduced liver collagen (-37.1 percent), regenerative nodules size (-22.1 percent), and fibrous septum thickness. Progranulin protein (immunohistochemistry) and mRNA (in situ hybridization) were found in fibrous septa and areas of bile duct proliferation in cirrhotic livers. Concluding, HF improved the histology and serum biochemistry of liver cirrhosis, with an important reduction of interstitial collagen and increased extracelullar matrix degradation by reducing profibrotic gene expression.
Asunto(s)
Animales , Femenino , Ratas , Matriz Extracelular/metabolismo , Cirrosis Hepática Experimental/terapia , Apoyo Nutricional/métodos , Soluciones/uso terapéutico , Aminoácidos/administración & dosificación , Aminoácidos/uso terapéutico , Glucosa/administración & dosificación , Glucosa/uso terapéutico , Hormonas/administración & dosificación , Hormonas/uso terapéutico , Inmunohistoquímica , Hibridación in Situ , Inyecciones Intraperitoneales , Cirrosis Hepática Experimental/metabolismo , Cirrosis Hepática Experimental/patología , Ratas Wistar , Sales (Química)/administración & dosificación , Sales (Química)/uso terapéutico , Soluciones/administración & dosificación , Tioacetamida , Vitaminas/administración & dosificación , Vitaminas/uso terapéuticoRESUMEN
We showed that guaraná (Paullinia cupana Mart var. sorbilis) had a chemopreventive effect on mouse hepatocarcinogenesis and reduced diethylnitrosamine-induced DNA damage. In the present experiment, we evaluated the effects of guaraná in an experimental metastasis model. Cultured B16/F10 melanoma cells (5 x 10(5) cells/animal) were injected into the tail vein of mice on the 7th day of guaraná treatment (2.0 mg P. cupana/g body weight, per gavage) and the animals were treated with guaraná daily up to 14 days until euthanasia (total treatment time: 21 days). Lung sections were obtained for morphometric analysis, apoptotic bodies were counted to calculate the apoptotic index and proliferating cell nuclear antigen-positive cells were counted to determine the proliferation index. Guaraná-treated (GUA) animals presented a 68.6 percent reduction in tumor burden area compared to control (CO) animals which were not treated with guaraná (CO: 0.84 ± 0.26, N = 6; GUA: 0.27 ± 0.24, N = 6; P = 0.0043), a 57.9 percent reduction in tumor proliferation index (CO: 23.75 ± 20.54, N = 6; GUA: 9.99 ± 3.93, N = 6; P = 0.026) and a 4.85-fold increase in apoptotic index (CO: 66.95 ± 22.95, N = 6; GUA: 324.37 ± 266.74 AB/mm², N = 6; P = 0.0152). In this mouse model, guaraná treatment decreased proliferation and increased apoptosis of tumor cells, consequently reducing the tumor burden area. We are currently investigating the molecular pathways of the effects of guaraná in cultured melanoma cells, regarding principally the cell cycle inhibitors and cyclins.
Asunto(s)
Animales , Femenino , Ratones , Antineoplásicos Fitogénicos/uso terapéutico , Proliferación Celular/efectos de los fármacos , Neoplasias Pulmonares/prevención & control , Melanoma Experimental/prevención & control , Paullinia/química , Extractos Vegetales/uso terapéutico , Neoplasias Pulmonares/secundario , Ratones Endogámicos BALB C , Melanoma Experimental/secundario , Antígeno Nuclear de Célula en Proliferación/análisisRESUMEN
Bovine papillomavirus (BPV) DNA sequences were detected in different tissues, in addition to epithelium. Cytogenetic abnormalities were observed in blood lymphocytes. The presence of more than one virus in a single tissue is a difficult aspect to evaluate, especially when the DNA sequences are detected in tissues that are not specifically targeted by the virus. BPV and bovine leukemia virus (BLV) are clastogenic, causing chromosome aberrations in peripheral blood lymphocytes. In the present study, we investigated the simultaneous presence of DNA sequences of both viruses and the possibility of vertical transmission and compared the types of chromosome aberrations related to viral action. BPV 1, 2, and 4 DNA sequences were found in three females of the herd and in their offspring. BLV DNA sequences were not detected in their progeny. A newborn calf that was negative for BLV infection showed specific chromosome rearrangements possibly related to the effect of infection with BPV.
Asunto(s)
Animales , Femenino , Análisis Citogenético/métodos , Hibridación in Situ/métodos , Papillomavirus Bovino 1/genética , Virus de la Leucemia Bovina/genética , Animales Recién Nacidos , Bovinos , Aberraciones Cromosómicas , Bandeo Cromosómico , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/veterinaria , Infecciones por Papillomavirus/virología , Cariotipificación , Leucosis Bovina Enzoótica/diagnóstico , Leucosis Bovina Enzoótica/virología , Reacción en Cadena de la Polimerasa , Papillomavirus Bovino 1/aislamiento & purificación , Virus de la Leucemia Bovina/aislamiento & purificaciónRESUMEN
Papillomaviruses have been reported to be very difficult to grow in cell culture. Also, there are no descriptions of cell cultures from lesions of bovine cutaneous papillomatosis, with identification of different bovine papilloma virus (BPV) DNA sequences. In the present report, we describe primary cell cultures from samples of cutaneous lesions (warts). We investigated the simultaneous presence of different BPV DNA sequences, comparing the original lesion to different passages of the cell cultures and to peripheral blood. BPV 1, 2 and 4 DNA sequences were found in lesion samples, and respective cell cultures and peripheral blood, supporting our previous hypothesis of the possible activity of these sequences in different samples and now also showing how they can be maintained in different passages of cell cultures.
Asunto(s)
Masculino , Femenino , Animales , Bovinos , Enfermedades de los Bovinos/patología , Enfermedades de los Bovinos/virología , Infecciones por Papillomavirus/genética , Papillomavirus Bovino 1/genética , Verrugas/patología , Verrugas/veterinaria , Verrugas/virología , ADN Viral/análisis , ADN Viral/genética , Técnicas de Cultivo de CélulaRESUMEN
Estudaram-se os aspectos ultra-sonográficos das lesões sugestivas de carcinoma de células transicionais (CCT), investigou-se a contribuição do mapeamento Doppler colorido e de amplitude no diagnóstico das lesões sugestivas de CCT e verificou-se a acurácia do método de biópsia ecodirigida por sucção traumática via sondagem uretral na coleta de material para confirmação diagnóstica CCT da bexiga. Para tal, foram selecionados nove cães que atendiam aos critérios de inclusão determinados. Destes, sete apresentavam CCT. A ultra-sonografia permitiu a detecção de massas exofílicas com características vegetantes em cinco cães, e de lesões infiltrativas na parede vesical estendendo-se para a uretra em dois. Pelo exame com Doppler colorido e de amplitude, constatou-se a vascularização interna da massa, indicativa de neoangiogênese tumoral, em quatro animais. A técnica de sucção traumática por aspiração permitiu a elucidação diagnóstica em cinco dos sete animais com CCT. Concluiu-se que, na maioria dos casos, a ultra-sonografia propicia a identificação de lesões sugestivas de CCT, constituindo a primeira técnica de diagnóstico por imagem indicada para pacientes que apresentem hematúria e disúria
The aims of this study were to evaluate the ultrasonographic findings in dogs with suggestive transitional cell carcinoma (TCC) lesion, to investigate the use of the color Doppler for the diagnosis of that condition and to establish the efficacy of the ultrasound catheter biopsy by suction via urethral probing for collecting material to confirm bladder TCC. A total of nine dogs were selected, seven with TCC confirmed. The ultrasonographic finding in TCC patients detected sessile masses in the bladder of five dogs and infiltrative mural lesion extent to the urethra in two dogs. The color Doppler and the power Doppler showed the internal vascular flow in four animals indicating tumor neoangiogenesis. It was concluded that the ultrasonography may identify abnormalities in the majority of cases with suggestive lesions of TCC and the ultrasonographic evaluation should be considered as the first diagnostic imaging modality in patients presented with hematuria and dysuria
Asunto(s)
Animales , Perros , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/veterinaria , Biopsia con Aguja/veterinaria , Ultrasonografía Doppler en ColorRESUMEN
Cyclooxygenase-2 (COX-2) expression has been associated with development and progression in spontaneous human and dogs tumors. Studies demonstrated that non-steroidal anti-inflammatory drugs, which inhibit COX enzyme, may be used in the treatment of some tumors. Lymphoma is a systemic disease and the most common hematological malignancy in dogs. There are few studies about COX-2 expression in human and canine lymphoma. In this study, immunohistochemical evaluation for COX-2 expression was performed in 12 dogs with multicentric lymphoma. The diagnosis was confirmed by histopathological examination. Six samples of normal lymph nodes were either used in the study. No COX-2 immunoreactivity was detected in all samples from canine lymphoma and normal lymph nodes, as well previous studies in canine lymphoma(AU)
La expresión de la ciclooxigenasa-2 (COX-2) se ha asociado con el desarrollo y progresión de tumores espontáneos humana y canina. Los estudios han demostrado que los antiinflamatorios no esteroideos, inhibidores de la COX-2 pueden ser utilizados para tratar algunos tumores. El linfoma es una enfermedad sistémica, considerada la neoplasia hematopoyética más frecuente en los perros. Hay pocos estudios sobre la expresión de la COX-2 en los linfomas en los seres humanos y perros. En este estudio, la expresión de COX-2 fue evaluada por inmunohistoquímica en 12 perros con linfoma multicéntrico. El diagnóstico fue confirmado por histopatología. Seis muestras de los ganglios linfáticos normales fueron evaluadas también. En ninguna de las muestras de los ganglios linfáticos normales o neoplásicos se detectó la expresión de la COX-2, corroborando los resultados de estudios previos en el linfoma canino(AU)
Asunto(s)
Animales , Masculino , Femenino , Perros , Inhibidores de la Ciclooxigenasa 2 , Inmunohistoquímica/métodos , Inmunohistoquímica , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/aislamiento & purificación , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Neoplasias/patología , Neoplasias/veterinaria , Linfoma/diagnóstico , Enfermedades de los Perros , Linfoma/patología , Linfoma/veterinaria , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/patologíaRESUMEN
The morphology of the skin of the mutant hairless USP mouse was studied by histological, histochemical and immunohistochemical methods and compared to the skin of BALB/c mice. Representative sections of the dorsal skin from mice of both strains aged 18 days, and 1, 3, 6, and 8 months were studied. Sections stained with hematoxylin and eosin showed cystic formations called utricles and dermal cysts in the dermis that increased in size and number during growth. Skin thickness increased significantly at 8 months. Sections stained with picrosirius and examined with polarized light, displayed different colors, suggesting different thicknesses of dermal collagen fibers (probably types I and III). Weigert, Verhoeff and resorcin-fuchsin stains revealed fibers of the elastic system. The PAS and Alcian blue methods revealed neutral and acid glycosaminoglycans in the skin ground substance of both mouse strains. Immunohistochemical staining for fibronectin and laminin did not show differences between the mutant and BALB/c mice. Mast cells stained by the Gomori method and macrophages positive for HAM 56 antibodies were observed in both mouse strains. Except for the presence of enlarged cysts in the hairless strain, no qualitative differences were found during development of the skin of BALB/c and the mutant hairless mice.
Asunto(s)
Animales , Masculino , Femenino , Ratones , Tejido Conectivo/química , Ratones Pelados/genética , Piel/patología , Histocitoquímica/métodos , Inmunohistoquímica , Ratones Endogámicos BALB C , Ratones Mutantes , Piel/química , Coloración y Etiquetado/métodosRESUMEN
Verificou-se o valor do emprego do laser diodo Ga-As-SHLD para auxiliar o processo de cicatrizaçäo cutânea em felinos. Utilizaram-se 21 animais que foram submetidos à ovariohisterectomia, 9 pertencendo ao grupo controle e 12 submetidos à laserterapia. Os exames anátomopatológicos foram realizados nos dias 2, 4 e 8 de pós-operatório, juntamente com avaliaçäo macroscópica. Concluiu-se que a aplicaçäo do laser diodo Ga-As-SHLD auxiliou o processo cicatricial da ferida cirúrgica por aumento de resistência à tensäo
Asunto(s)
Animales , Gatos , Cicatrización de Heridas/efectos de la radiación , Histerectomía/veterinaria , Terapia por Láser/veterinaria , Rayos Láser/uso terapéuticoRESUMEN
Os aspectos clínicos e epidemiológicos de três casos de Síndrome de Imunodeficiência Adquirida dos Felinos (SIDAF), relacionados à infecçäo pelo FIV säo descritos neste estudo. Dois dos animais eram gatos siameses, com três anos de idade sendo um macho e uma fêmea e o terceiro, um gato doméstico de pelo curto, macho, com seis anos de idade. Os sintomas observados foram febre, icterícia, esplenomegalia, emaciaçäo e fraqueza. As principais alteraçöes hematológicas foram a anemia, näo relacionada à Hemobartonelose, encontrada em dois gatos, neutrofilia encontrada nos três animais e linfopenia observada em um. A necrópsia realizada em dois dos animais revelou que a sepse foi a maior causa da piora das condiçöes clínicas nos gatos infectados pelo FIV. Moraxella phenilpiruvica foi isolada do rim de um dos animais. Todos os gatos apresentaram testes sorológicos positivos para FIV e negativos para FeLV e manifestavam há longo tempo sinais clínicos relacionados à SIDAF
Asunto(s)
Animales , Masculino , Femenino , Virus de la Inmunodeficiencia Felina , Síndrome de Inmunodeficiencia Adquirida del Felino/diagnóstico , Síndrome de Inmunodeficiencia Adquirida del Felino/epidemiología , GatosRESUMEN
O tumor de Ehrlich cresce na forma sólida quando inoculado no coxim plantar de camundongos, disseminando-se para o linfonodo poplíteo. Este estudo foi realizado com o intuito de caracterizar as células tumorais que cresceram no coxim plantar e as que migraram para o linfonodo poplíteo. O volume nuclear dessas células foi medido com o auxílio de ocular cariométrica. A quantificaçäo do DNA foi feita através de citofotometria em células coradas pelo método de Feulgen. As células tumorais encontradas nos linfonodos poplíteos uma hora após a inoculaçäo no coxim plantar näo apresentaram diferenças estatísticas do tumor ascítico original e das células tumorais do coxim plantar em relaçäo à quantidade de DNA, no mesmo tempo experimental. As células tumorais dos linfonodos poplíteos aos 30 dias após a inoculaçäo mostraram menor volume nuclear e a mesma quantidade de DNA do que as que cresceram no coxim plantar. As células tumorais presentes no coxim plantar 30 dias após a inoculaçäo mostraram uma quantidade maior de DNA do que as colhidas uma hora após a inoculaçäo. Estes resultados sugerem um possível efeito seletivo nas células do tumor de Ehrlich que crescem no coxim plantar, mas näo quando de sua metastatizaçäo para o linfonodo regional
Asunto(s)
Animales , Carcinoma de Ehrlich , ADN de Neoplasias , Metástasis Linfática , RatonesRESUMEN
Adult BALB/c male mice were injected with a single dose of ethyl nitroso urea (ENU; 250 mg/Kg, ip) and mated to C57BL/6, DBA/2 AND A/J adult females 13 weeks later. F1 males were mated with BALB/c females and F2 females were then backcrossed to the F1 parents. One BALB/c male mouse thus teated gave origin to a mutant presenting hair and skin alterations similar to those of natural hairless mutants. The new mutation is located on chromosome 14 near the Es10 locus, and probably at the same locus for the hairless mutation. Similar to the hairless mouse, this new mutant has a normal phenotype at birth and after three weeks starts to loose hair which is never replaced. Additionally, the skin becomes thickened and wrinkled. One feature that distinguishes this mutant from other hairless mice is the peculiar enlargement of its axillary and cervical lymph nodes. The new mutant develops membranoproliferative glomerulonephritis similar to the rhino mouse, one of the hariless allele mutants already described in the literature, but with a much later onset