Poliuretana de mamona (Ricinus communis) para desvio da crista tibial no cão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mecanismos celulares e moleculares que controlam o desenvolvimento e o crescimento muscular

O músculo estriado esquelético é formado pela associação de fibras musculares com a matriz extracelular. Esse tecido possui alta plasticidade e o conhecimento das características morfológicas, da miogênese, e da dinâmica do crescimento é importante para o entendimento da morfofisiologia bem como para a seleção de animais visando a melhoria na produção de carne. A maioria dos músculos estriados originam-se de células precursoras do mesoderma a partir dos somitos do embrião e o controle da diferenciação ocorre pela ação de fatores indutores ou inibidores. Um grupo de fatores transcricionais, pertencentes à família MyoD tem um papel central na diferenciação muscular. Coletivamente chamados de Fatores de Regulação Miogênica (MRFs), são conhecidos quatro tipos: MyoD, myf-5, miogenina e MRF4. Esses fatores ligam-se à seqüências de DNA conhecidas como Ebox (CANNTG) na região promotora de vários genes músculo-específicos, levando à expressão dos mesmos. As células embrionárias com potencial para diferenciação em células musculares (células precursoras miogênicas) expressam MyoD e Myf-5 e são denominadas de mioblastos. Essas células proliferam, saem do ciclo celular, expressam miogenina e MRF4, que regulam a fusão e a diferenciação da fibra muscular. Uma população de mioblastos que se diferencia mais tardiamente, as células miossatélites, são responsáveis pelo crescimento muscular no período pós natal, que pode ocorrer por hiperplasia e hipertrofia das fibras. As células satélites quiescentes não expressam os MRFs, porém, sob a ação de estímulos como fatores de crescimento ou citocinas, ocorre a ativação desse tipo celular que prolifera e expressa os MRFs de maneira similar ao que ocorre com as células precursoras miogênicas durante a miogênese. Os mecanismos de crescimento muscular são regulados pela expressão temporal dos (MRFs), que controlam a expressão dos genes relacionados com o crescimento muscular.

REVERSIBILITY OF ADENOMATOUS HYPERPLASIA IN THE GASTRIC STUMP AFTER DIVERSION OF BILE REFLUX IN RATS

Morphological and phenotypical patterns of proliferative epithelial lesions induced in the gastric stump mucosa by duodenal content reflux after Billroth II partial gastrectomy (BII) were evaluated in rats. Control animals were either sham-operated or submitted at different times after BII to Roux-en-Y (RY) surgical procedure which prevents duodenal reflux. The lesions were analysed using routine haematoxylin and eosin staining, immunohistochemical staining for pepsinogen isoenzyme 1 and histochemical procedures for mucins (paradoxical Concanavalin A, galactose oxidase Schiff and sialidase galactose oxidase Schiff reactions). Mucosal hyperplasia (H) was observed in the group submitted to BII procedure 6 weeks after surgery. Adenomatous hyperplasia (AH) also appeared 6 weeks after induction of the reflux and its incidence and size increased until the 54th week of the experiment. RY procedure performed in the normal animals at the beginning of the experiment or at the 24th week after BII gastrectomy led to a significantly lower incidence of AH which was related to the moment of surgery. Most of H was due to pyloric mucosal hyperplasia. AH consisted mainly of gastric type glands but in some animals glands of the intestinal type Were present probably originating from the intestinal mucosa. Six mucinous adenocarcinomas were observed, all of them of intestinal type. This study demonstrates that AH induced by BII procedure is a reversible lesion and that the anomalous epithelial proliferation in the stoma may lead to adenocarcinomas.

EXPRESSION OF C-ERB B-2 PROTEIN AND DNA-PLOIDY IN BREAST CARCINOGENESIS

Objective.-to examine the c-erb B-2 expression and nuclear DNA content in samples of breast lesions to ascertain any relationship between c-erb B-2 expression and aneuploidy in the different types of proliferative breast lesions and in intraductal and invasive carcinomas.Design and Setting.-lmmunohistochemical analysis of c-erb B-2 expression and cytometric nuclear DNA assessment were performed in a series of 39 cases of intraductal hyperplasia without atypia, 7 cases of intraductal hyperplasia with atypia, 64 cases of intraductal carcinoma, and 85 cases of invasive breast carcinoma (30 of which had extensive intraductal component).Results.-Overexpression of c-erb B-2 was seen only in cases of carcinoma: 28 (43.7%) intraductal carcinomas and 15 (17.6%) invasive carcinomas. Aneuploidy was demonstrated in 3 (43.0%) cases of intraductal hyperplasia with atypia, in 54 (84.4%) cases of intraductal carcinoma, and in 63 (74.2%) cases of invasive carcinoma. All cases of intraductal hyperplasia without atypia were euploid and none expressed c-erb B-2. Among the carcinomas (intraductal and invasive) there was a strong relationship between aneuploidy and c-erb B-2 expression. In most instances, the intraductal and invasive components of the 30 invasive carcinomas with extensive intraductal component displayed similar DNA content and c-erb B-2 immunoreactivity; whenever there was a difference, the intraductal component tended to be aneuploid (five out of six cases) and c-erb B-2 positive (one case), in contrast to the respective invasive component.Conclusions.-The higher frequency of aneuploidy and c-erb B-2 expression in intraductal carcinomas in comparison with invasive carcinomas suggests there is not a linear relationship between DNA content abnormalities and neoplastic progression and that some invasive breast carcinomas evolve without an identifiable intraductal phase or are unrelated to disturbances at the c-erb B-2 locus.

Immunosuppression in paracoccidioidomycosis: T cell hyporesponsiveness to two Paracoccidioides brasiliensis glycoproteins that elicit strong humoral immune response

To assess human cellular immune response to paracoccidioidomycosis (PCM), lymphocyte proliferative responses to purified antigens from Paracoccidioides brasiliensis were determined in healthy persons previously infected by the fungus (positive donors), in healthy noninfected persons (controls), and in PCM patients. Affinity-purified gp70 and gp43, the two major antigens in humoral immune responses, were used, Both induced lymphocyte proliferation (gp43 species-specific) in positive donors but not in controls; healthy persons previously infected by Histoplasma capsulatum reacted to gp70 and not to gp43, A similar cross-reactivity in antibody response to gp70 was previously reported; however, antibody response to gp43 has been considered specific, Lymphocytes from PCM patients, who, unlike positive donors, have high levels of anti-gp43 and anti-gp70 antibodies, proliferated poorly with gp70 and gp43 but better with other stimuli, This dichotomy between humoral and cellular antigen-specific responses suggests a Th2 immune response in PCM, which may be related to failure to control the infection.

Tibial segmental bone defect treated with bone plate and cage filled with either xenogeneic composite or autologous cortical bone graft

Tibia segmental defect healing in sheep were clinically, radiographically and histologically evaluated. Twelve young sheep aged four to five months were divided into two groups, G1 and G2. A 3.5 cm long segmental defect was created in the right tibial diaphysis with maintenance of the periosteum. The bone defects in both groups were stabilized with a bone plate combined with a titanium cage. In G1 the cage was filled with pieces of autologous cortical bone graft. In G2 it was filled with a composite biomaterial which consisted of inorganic bovine bone, demineralized bovine bone, a pool of bovine bone morphogenetic proteins bound to absorbable ultra-thin powdered hydroxyapatiteand bone-derived denaturized collagen. Except for one G1 animal, all of them showed normal limb function 60 days after surgery. Radiographic examination showed initial formation of periosteal callus in both groups at osteo-tomy sites, over the plate or cage 15 days postoperatively. At 60 and 90 days callus remodeling occurred. Histological and morphometric analysis at 90 days after surgery showed that the quantity of implanted materials in G1 and G2 were similar, and the quantity of new bone formation was less (p = 0.0048) and more immature in G1 than G2, occupying 51 +/- 3.46% and 62 +/- 6.26% of the cage space, respectively. These results suggest that the composite biomaterial tested was a good alternative to autologous cartical bone graft in this experimental ovine tibial defect. However, additional evaluation is warranted prior to its clinical usage.

The annual testicular cycle of the domestic quail (Coturnix coturnix japonica)

A morphometric study was conducted on the testis of the domestic quail Coturnix coturnix japonica to determine testicular kinetics. We investigated the variability along the year of testicular parameters such as seminiferous tubule diameter, germinal epithelium height and amount of meiotic figures of maturing spermatids in the seminiferous epithelium and of sperm in the tubular lumen. The results of morphometric analysis showed the occurrence of an annual testicular cycle defined by four distinct phases: a resting phase (at the end of summer), a recrudescence phase (in the fall), a proliferative phase (at the end of winter and beginning of spring), and a regression phase (spring and summer). We also observed that the testes of adult quails present elevated and maximal spermatogenic activity in fall-winter (short-day period) and at the beginning of spring, respectively, and lower values in spring and summer (long-day periods), with minimum values at the end of summer.

Paulista registry of glomerulonephritis: 5-year data report

Background. The Paulista Registry of Glomerulopathies was created in May 1999 and comprises several centres of São Paulo, the most populous Brazilian State, that concentrates people from all regions of the country who look for health care.Methods. This report includes data from 2086 patients from Brazil submitted to renal biopsy due to the presumed diagnosis of glomerular diseases, registered prospectively since May 1999 until January 2005. Data were collected by the integrants of the 11 centres involved, utilizing a standardized questionnaire.Results. The mean age of the patients was 34.5 +/- 14.6 years. Primary glomerular diseases were more frequent in males (55.1%) than in females; on the other hand, secondary glomerular diseases were more frequent in females (71.8%). The most common clinical presentation was nephrotic syndrome and the frequency of hypertension, at this time, was 55.5%. There was a predominance of indication of biopsies in the third, fourth and fifth decades of life. The most common primary glomerular diseases were focal and segmental glomerulosclerosis (29.7%), followed by membranous nephropathy (20.7%), IgA nephropathy (17.8%), minimal change disease (9.1%), membranoproliferative glomerulonephritis (7%), crescentic glomerulonephritis (4.1%), advanced chronic glomerulopathy (4%), non-IgA mesangial glomerulonephritis (3.8%), diffuse proliferative glomerulonephritis (2.5%), focal segmental proliferative glomerulonephritis (1%) and others (0.3%). The most frequent secondary glomerular disease was lupus nephritis, corresponding to 66.2% of the cases, followed by post-infectious glomerulonephritis (12.5%), diabetic nephropathy (6.2%), diseases associated to paraproteinaemia (4.9%), hereditary diseases (4.6%), vasculitis (3.2%), malignancies (0.9.%), secondary focal segmental glomerulosclerosis (0.6%) and others (0.9%).Conclusion. Focal segmental glomerulosclerosis was the most frequent primary glomerular disease, followed by membranous nephropathy and IgA nephropathy. Lupus nephritis predominated over all the other secondary glomerular diseases.

Computer-assisted analysis of cell proliferation markers in oral lesions

Abnormalities in any component of the cell cycle regulatory machine may result in oral. cancer, and markers of cell proliferation have been used to determine the prognosis of tumor progression. The aim of this study was to determine whether silver-stained nucleolar organizer region (AgNOR) and Ki-67 measurements could improve the assessment of growth rates in oral lesions. Eighty-three oral biopsies were studied, 20 of which were classified as fibrous inflammatory hyperplasia (FIH), 40 as leukoplakia (LKP) and 23 as oral. squamous cell carcinoma (OSCC). Within the LKP group, 22 out of 29 biopsies were diagnosed as non-dysplastic leukoplakia (LK) and 18 as dysplastic teukoptakia (DLK), presenting discrete, moderate and severe dysplasia. Ki-67 immunotabeting of the lesions increased steadily in the following order: FIH, DLK, LK and OSCC, indicating that Ki-67 is a good marker for predicting the protiferative fraction among benign, premalignant and malignant oral lesions. The median values of AgNOR parameters indicate that the morphometric index gives better results regarding the proliferative rate than the numerical one. A series of linear regressions between AgNOR parameters and Ki-67 showed positive associations. We conclude that a combination of Ki-67 and morphometric AgNOR analyses could be used as an aid in the determination of the protiferative status of oral epithelial. cells in oral cancer. (C) 2007 Elsevier GmbH. All rights reserved.

Bone healing in drill hole defects in spontaneously hypertensive male and female rats' femurs. A histological and histometric study

Objective: the aim of this study was to evaluate the bone healing in spontaneously hypertensive rats (SHR) and compare the results with normotensive rats, evaluating male and female animals.Methods: A bone drill defect was created in the left femur of 24 SHR (12 males and 12 females) and 24 normotensive rats (12 males and 12 females). The animals were divided into two groups and sacrificed 7 and 21 days after the surgical procedure. After the routine laboratory processing, histological and histometric analysis were carried out and data were submitted to ANOVA and Tukey's test (5%).Results: Males and females from the same group had similar histological characteristics. After seven days, all animals presented irregular bone trabeculae. The periosteal osteoblasts were flattened in SHR, and presented a cuboid shape in normotensive animals. After 21 days, the bone defects of all specimens showed a linear closure in all the superficial extension. In addition, SHR presented flattened osteoblasts surrounding the bone trabeculae, while normotensive ones showed cuboidal cells. Statistical analysis of the histometric data indicated similar means between the male and female groups, except for normotensive rats on day 7. In addition, a larger amount of new bone formation was observed in hypertensive when compared to normotensive rats on day 27, in males as well as females.Conclusion: We conclude that bone healing in SHR was more significant than in normotensive ones, as shown by the histological and histometric evaluation 21 days after surgery.

Reduction of erythroid progenitors in protein-energy malnutrition

Protein-energy malnutrition is a syndrome in which anaemia together with multivitamin and mineral deficiency may be present. The pathophysiological mechanisms involved have not, however, yet been completely elucidated. The aim of the present study was to evaluate the pathophysiological processes that occur in this anaemia in animals that were submitted to protein-energy malnutrition, in particular with respect to Fe concentration and the proliferative activity of haemopoietic cells. For this, histological, histochemical, cell culture and immunophenotyping techniques were used. Two-month-old male Swiss mice were submitted to protein-energy malnutrition with a low-protein diet (20g/kg) compared with control diet (400 g/kg). When the experimental group had attained a 20% loss of their original body weight, the animals from both groups received, intravenously, 20IU erythropoietin every other day for 14 d. Malnourished animals showed a decrease in red blood cells, Hb concentration and reticulocytopenia, as well as severe bone marrow and splenic atrophy. The results for serum Fe, total Fe-binding capacity, transferrin and erythropoietin in malnourished animals were no different from those of the control animals. Fe reserves in the spleen, liver and bone marrow were found to be greater in the malnourished animals. The mixed colony-forming unit assays revealed a smaller production of granulocyte-macrophage colony-forming units, erythroid burst-forming units, erythroid colony-forming units and CD45, CD117, CD119 and CD71 expression in the bone marrow and spleen cells of malnourished animals. These findings suggest that, in this protein-energy malnutrition model, anaemia is not caused by Fe deficiency or erythropoietin deficiency, but is a result of ineffective erythropoiesis.

Spectrum of carcinoembryonic antigen immunoreactivity from isolated ductal hyperplasias to atypical hyperplasias associated with infiltrating ductal breast cancer

Aims - To study the immunohistochemical expression of carcinoembryonic antigen (CEA) in ductal hyperplasia of the breast and to investigate its putative relation with atypia and co-existing infiltrating ductal carcinoma.Methods - Paraffin wax embedded tissue from 37 cases of isolated ductal hyperplasia (five with atypia and 32 without atypia) and 25 cases of ductal hyperplasia associated infiltrating ductal carcinoma (IDC) (seven with atypia and 18 without atypia) was stained with a monoclonal anti-CEA antibody using a standard avidin biotin immunoperoxidase method.Results - CEA immunoreactivity was observed in eight (12.8%) ductal hyperplasia cases. The percentage of CEA positivity in ductal hyperplasia cases with atypia (33.3%) was substantially higher than that observed in cases of ductal hyperplasia without atypia (8.0%). Six cases of ductal hyperplasia associated IDC reacted with CEA; in these six cases the neoplastic cells of the co-existing carcinoma were also CEA positive. The percentage of CEA immunoreactivity in ductal hyperplasia associated IDC was higher than that observed in isolated ductal hyperplasia (24.0 v 5.4%). The percentage of CEA immunoreactivity in atypical ductal hyperplasia associated IDC was similar to that observed in IDC alone (42.9 v 40.0%).Conclusions-The presence of CEA immunoreactivity has been confirmed in benign proliferative breast lesions. The prevalence of such immunoreactivity increases from 3.1% in isolated, nonatypical ductal hyperplasia to 42.9% in atypical ductal hyperplasia associated IDC. This finding and the similarity of the frequency of CEA positivity in atypical ductal hyperplasia associated IDC and in IDC alone suggests that there is a pathogenetic link between ductal hyperplasia and some types of breast cancer.

The proliferating cell nuclear antigen index in breast carcinomas does not correlate with mitotic index and estrogen receptor immunoreactivity

To investigate the expression of a marker of cell proliferation (PCNA/Cyclin) and its putative relationship with histological grading, mitotic index and estrogen receptor immunoreactivity, we studied twenty-seven cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. The PCNA and estrogen receptor were detected by the PC10 and H222 monoclonal antibodies respectively, using an avidin-biotin-pernxidase method. The median value of PCNA index was 20.9% with a range from 1.4 to 84.2%. We did not find any significant relationship between PCNA index anti the histological grading, mitotic index and estrogen receptor immunoreactivity. We conclude that PCNA detected by the monoclonal antibody PC10 in formalin-fixed material looks at present unrealiable as a proliferation marker in breast carcinoma.

Oral paracoccidioidomycosis: a study of 36 South American patients

Paracoccidioidomycosis (South American blastomycosis) is an uncommon, progressive systemic mycosis, virtually only seen in persons who have visited Latin America. Reports of oral lesions are extremely rare in the English-language literature. Thirty-six adults with oral lesions as the first sign of paracoccidioidomycosis are described; this appears to be the largest series in the dental literature. All had chronic proliferative mulberry-like ulcerated oral lesions; the diagnosis was confirmed histologically. The gingiva or alveolar process was the typical site, but lesions were also seen particularly on the palate and lip. Most of the patients proved to have detectable pulmonary involvement. Patients with lesions in the oropharynx, tongue, or floor of mouth all had confirmed pulmonary lesions.

Immunotherapy against murine experimental visceral leishmaniasis with the FML-vaccine

The fucose mannose ligand (Leishmania donovani FML)-saponin vaccine has earlier shown its immunoprophylactic potential against visceral leishmaniasis in the CB hamster (87.7% of parasite load reduction), Balb/c (84.4%) and Swiss albino mouse (85-93%) models. In this investigation its specific immunotherapeutic efficacy against L. donovani infection in Balb/c mice was studied. The effects of vaccine treatment on the Immoral response, delayed type of hypersensitivity to promastigote lysate (DTH), cytokine levels in sera and reduction of the liver parasitic load of L. donovani infected mice, were examined. The types and subtypes of anti-FML antibodies increased significantly in the vaccinees over the saline and saponin controls. As expected for a saponin vaccine, the highest ratios were found in relation to IgG1, IgG2a and IgG2b (4.4, 5 and 2.5, respectively). The DTH response and the in vitro ganglion cell proliferative response against FML antigen were also significantly higher than controls (P < 0.005). Concomitantly, an impressive and specific decrease of liver parasitic burden was detected only in vaccine-treated animals (94.7%). Our results indicate that the therapeutic FML-vaccine has a potent effect on modulation of the murine infection leading to the reduction of parasitic load and signs of disease, being a new potential tool in the therapy and control of visceral leishmaniasis. (C) 2003 Elsevier Ltd. All rights reserved.