Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection.

As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)-G is well described as a tolerogenic molecule, we evaluated HLA-G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA-G expression was assessed by immunohistochemistry. No HLA-G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane-bound HLA-G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA-G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA-G expression presented a higher median HBV DNA viral load (105 copies/mL) than those who did not express HLA-G (10(3.7) copies/mL). These results indicate that HLA-G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection.

Low-carbohydrate and high-fat diets on the promotion of hepatic steatosis in rats.

AIM: The present work looked for to evaluate in rats the impact of different diets (high-lipid and high-lipid+high-protein) on liver, verifying the occurrence of oxidative stress and steatosis. METHODS: The animals were treated with the respective diets (Group HLS: high-lipid diet with 50% of saturated fat; Group HPLS: high-lipid and high-protein diet with 50% of saturated fat and 40% of protein; Group Control: control diet AIN-93) for 28 days. After this period the animals were sacrificed for hepatic determinations of MDA, reduced GSH, vitamin E, steatosis and glycemia. RESULTS: The results showed higher glycemia in the group HPLS, high concentration of MDA and GSH in the group Control and decreased hepatic vitamin E concentration in the groups that received the high-lipid diets. The hepatic fat was higher in the groups HPLS and HLS in relation to the Group Control, however HPLS presenting high level of fat concentration, showing similar results as the steatosis. CONCLUSION: the fat increase in the diet promoted increase of the oxidative stress, evidenced by the decrease in the hepatic concentration of vitamin E, showing its antioxidant role against the probable generated free radicals, the ones which possibly exercised a role in the steatosis occurrence.

Histopathological changes in the placentas and fetuses of mice infected with Trypanosoma cruzi isolated from the Myotis nigricans nigricans bat.

Histopathological changes and placental transmission were studied in the late stages of pregnancy in mice infected with a strain of Trypanosoma cruzi, isolated from a Myotis nigricans nigricans bat. Large amastigote nests were observed in uterine muscles, as well as in decidual and endothelial placental cells. In addition, persistent coagulative and fibrotic vascular degeneration was observed. Large amastigote burdens were found in giant cells, spongioblasts and endothelial cells within the labyrinthine layer. Transplacental transmission was confirmed in 30% of the fetuses examined, in which amastigote nests were seen only in striated muscle. During the acute phase, intrauterine development was impaired as the result of parasitic invasion of the placenta, and fetal mortality rose to 10%.

Communication between organ donor families and recipients: a definitely controversial subject.

In transplant centers, few topics are more controversial than communication between organ donor families (ODF) and recipients (RE). The Organ Procurement Organizations and transplant centers have felt obliged to protect the confidentiality and interests of ODF and RE. However, some authors have reported favorable effects of contact between ODF and RE. This study sought to investigate the current situation of the communication between ODF and RE from the viewpoint of transplanted patients (n = 50) and waiting transplant patients (n = 50) at a Brazilian University Hospital, ODF (n = 10), physicians from transplant centers (n = 50), as well as the opinion of the general population of a Brazilian city (n = 100). This work was developed as a survey whose questions related to the issue of communication between ODF and RE. The results showed that the majority of transplanted patients (82%) and patients awaiting transplant (60%) wanted to meet ODF to express their gratitude for receiving the organ. Likewise, ODF (67%) wanted to have a meeting with recipients, which allowed them to confirm the benefit of their donation. The general population was also favorable (66%) to ODF and RE communication. In contrast, the physicians (74%) were opposed to the ODF and RE contact. They affirmed that direct contact could lead to serious emotional conflicts or attempts of material involvement. One believes that decisions concerning the contact between ODF and RE would have to be determined by the involved parties. The transplant team could analyze the requests case by case, but ODF and RE must have the right to make the final decision.

Liver transplantation at a university hospital, faculty of the medicine of Ribeirão Preto, University of São Paulo: results for the first 60 recipients.

The purpose of the present article was to present the series operated by a Liver Transplant Group of the interior of the State of Sao Paulo, Brazil. Sixty patients were transplanted from May 2001 to May 2007. Thirty percent of the patients had alcoholic cirrhosis. 18.3% had C virus-induced cirrhosis, 10% had C virus- and alcohol-induced cirrhosis, 6% had B virus-induced cirrhosis, 13.3% had cryptogenic cirrhosis, 8.3% autoimmune cirrhosis, 13.3% had familial amyloidotic polyneuropathy (FAP), and 13.3% had hepatocellular carcinomas. The series was divided by a chronological criterion into two periods: A (n = 42) and B (n = 18) with the latter group operated based upon the Model for End-stage Liver Disease (MELD) criterion. Sixty-nine percent were men. Age ranged from 14 to 66 years. Period A included 12% Child A: 59.2%, Child B; 24%, Child C; and 4.8%, FAP. Period B comprises 22.2% Child A: 11.1%, Child B: 33.3%, Child C: and 33.3%, FAP. MELD scores ranged from 8 to 35 for period A and from 14 to 31 for period B. Intraoperative mortality was 2/42 patients for period A and 0/18 for period B, overall postoperative mortality was 40% including for period A, 35% among Child B and C patients, and 5% among FAP and Child A patients (P < .05) and 16.6% for period B among 11.1% Child B patients and 5.5% FAP patients; 3.3% of patients required retransplantation due to hepatic artery thrombosis. Real postoperative survival was 60% during period A and 83.3% during period B, with an overall survival rate of 67% for the two periods. The present results show levels of postoperative mortality, (especially during period B), and survival rates similar to those reported by several other centers in Brazil.

The use of light-emitting diodes to stimulate mitochondrial function and liver regeneration of partially hepatectomized rats.

The biostimulating effect of laser radiation has been observed in many areas of Medicine. However, there are still several questions to be answered, among them the importance of light coherence in the stimulatory process. In the present study, we used light-emitting diodes (LED) to promote the stimulation of liver regeneration after partial hepatectomy in rats. Fourteen male Wistar rats weighing 200-250 g were submitted to partial hepatectomy (70%) followed by LED light irradiation (630 nm) of the remaining part of the liver at two doses, i.e., 10 (N = 7) and 140 (N = 7) J/cm(2). A group irradiated with laser, 590 nm (N = 7, 15 J/cm(2)) was performed for the study of proliferating cell nuclear antigen-labeling index. Data are reported as mean +/- SEM. Statistical comparisons of the groups were performed by analysis of variance for parametric measurements followed by the Bonferroni post-test, with the level of significance set at P < 0.05. Respiratory mitochondrial activity was increased in the irradiated groups (states 3 and 4; P < 0.05), with better results for the group exposed to the lower LED dose (10 J/cm(2)). The proliferating cell nuclear antigen-labeling index, by immunohistochemical staining, was similar for both LED-exposed groups (P > 0.05) and higher than for the control group (P < 0.05). The cell proliferation index obtained with LED and laser were similar (P > 0.05). In conclusion, the present results suggest that LED irradiation promotes biological stimulatory effects during the early stage of liver regeneration and that LED is as effective as laser light, independent of the coherence, divergence and cromaticity.

The use of light-emitting diodes to stimulate mitochondrial function and liver regeneration of partially hepatectomized rats

The biostimulating effect of laser radiation has been observed in many areas of Medicine. However, there are still several questions to be answered, among them the importance of light coherence in the stimulatory process. In the present study, we used light-emitting diodes (LED) to promote the stimulation of liver regeneration after partial hepatectomy in rats. Fourteen male Wistar rats weighing 200-250 g were submitted to partial hepatectomy (70 percent) followed by LED light irradiation (630 nm) of the remaining part of the liver at two doses, i.e., 10 (N = 7) and 140 (N = 7) J/cm². A group irradiated with laser, 590 nm (N = 7, 15 J/cm²) was performed for the study of proliferating cell nuclear antigen-labeling index. Data are reported as mean ± SEM. Statistical comparisons of the groups were performed by analysis of variance for parametric measurements followed by the Bonferroni post-test, with the level of significance set at P < 0.05. Respiratory mitochondrial activity was increased in the irradiated groups (states 3 and 4; P < 0.05), with better results for the group exposed to the lower LED dose (10 J/cm²). The proliferating cell nuclear antigen-labeling index, by immunohistochemical staining, was similar for both LED-exposed groups (P > 0.05) and higher than for the control group (P < 0.05). The cell proliferation index obtained with LED and laser were similar (P > 0.05). In conclusion, the present results suggest that LED irradiation promotes biological stimulatory effects during the early stage of liver regeneration and that LED is as effective as laser light, independent of the coherence, divergence and cromaticity.

Therapeutic effect of hyperbaric oxygen in hepatic artery thrombosis and functional cholestasis after orthotopic liver transplantation.

Among the postoperative complications, hepatic artery thrombosis can occur in up to 10% of adult orthotopic liver transplants and intervention is indicated when this occurs within 30 days by retransplantation. Primary graft dysfunction, which can occur in up to 30% of the cases and is another potential complication, although reversible, has a relatively high mortality rate. Hyperbaric therapy, an efficient mode of tissue oxygenation, is being used in an increasing number of clinical situations. We report here two cases where hyperbaric oxygen therapy greatly benefited patients with complications after orthotopic liver transplantation: one with hepatic artery thrombosis and the other with primary graft dysfunction. Both patients showed rapid clinical recovery with gradual reduction of liver and canalicular enzymes soon after commencing hyperbaric oxygen therapy.

Effect of hyperbaric oxygen on liver regeneration in a rat model.

Hyperbaric oxygen therapy is a treatment that has been gradually implemented for the treatment of several pathologic conditions. The present study evaluated the effect of hyperbaric oxygen therapy for hepatic regeneration and its relationship to mitochondrial function. Male Wistar rats underwent partial hepatectomy (70%) and subsequently underwent two sessions of hyperbaric oxygen (90 minutes each, at a pressure of 2 ATA). The animals were sacrificed at 24 and 48 hours after surgery. Hepatic regeneration was evaluated by the dry weight of the remaining liver, the hepatic regeneration rate, the hepatic DNA content, and the hepatocyte proliferation rate using the "proliferating cell nuclear antigen" (PCNA) content. Function of the mitochondria was evaluated by its oxygen consumption during respiratory states 3 and 4, its respiratory control ratio (RCR), its membrane potential, as well as its osmotic swelling. We also measured serum levels of aminotransferases. The results revealed an increased dry weight of the remaining liver, regeneration rate, and DNA content at 24 and 48 hours after hepatectomy. The hepatocyte proliferation rate was significantly higher among animals treated with hyperbaric oxygen therapy at 48 hours after surgery. There was no significant difference in aminotransferase levels. Mitochondrial respiration revealed reduced oxygen consumption in state 3 after 48 hours. These results demonstrated that hyperbaric oxygen stimulates hepatic regeneration at 24 and 48 hours after 70% hepatectomy. The effect of hyperbaric oxygen on hepatic tissue occurs without tissue damage and protects mitochondria after 48 hours.

The expression of p63 and cytokeratin 5 in mixed tumors of the canine mammary gland provides new insights into the histogenesis of these neoplasms.

Cytokeratin 5 and p63 have been described as basal and myoepithelial cell markers in human breast. Mixed tumors of the canine mammary gland have been associated with a myoepithelial origin. Cytokeratin 5 expression has not been evaluated in these tumors. We investigated the relation between cytokeratin 5 and p63 double-immunohistochemical expression in 23 mixed tumors of the canine mammary gland (10 benign mixed tumors and 13 carcinomas arising from benign mixed tumors) and their origin. Cytokeratin 5 and p63 co-expression was observed in myoepithelial cells of benign mixed tumors, as well as in squamous differentiation of carcinoma arising from benign mixed tumors. Though a few interstitial spindle cells of the mesenchymal components expressed both p63 and cytokeratin 5, the basal epithelial cells were labeled only by cytokeratin 5. The co-expression of p63 and cytokeratin 5 in myoepithelial cells and squamous differentiation suggest that, like in human breast, cytokeratin 5 can also be considered a myoepithelial- and squamous-cell differentiating marker in canine tumors. The presence of some interstitial spindle cells stained for p63 and cytokeratin 5 might be associated with a myoepithelial origin of the mesenchymal component of mixed tumors of the canine mammary gland. Moreover, contrary to p63, basal epithelial cells were labeled by cytokeratin 5, indicating that cytokeratin 5 may not represent an exclusive myoepithelial cell marker but also a basal epithelial cell marker in canine mixed tumors. According to these data, basal epithelial cells may be related to the origin of the epithelial component of mixed tumors of the canine mammary gland.

Expression of checkpoint kinase 2 in breast carcinomas: correlation with key regulators of tumor cell proliferation, angiogenesis, and survival.

Checkpoint kinase 2 (Chk2) is a cell-cycle-checkpoint kinase that may act as a tumor suppressor gene due to its important role in DNA damage signaling and cell cycle regulation. The role of Chk2 expression in mammary tumorigenesis, however, is still poorly understood. This study was designed to assess the relationship between the expression of Chk2 and well-established prognostic factors, including disease-free-survival and overall survival; and several regulators of cell proliferation and invasiveness in breast carcinomas, including oncogenes, tumor suppressor genes, apoptosis-related proteins, and angiogenesis-related markers. Immunohistochemistry with 27 primary antibodies was performed in 100 formalin-fixed paraffin-embedded samples of not otherwise specified invasive ductal carcinomas. Clinical data were retrieved from medical files. In normal mammary parenchyma adjacent to the tumors Chk2 stained the nuclei of epithelial cells. Downexpression of Chk2 protein was observed in 23 carcinomas and correlated with advanced disease. Among the regulators of tumor cell proliferation and invasiveness analyzed, the downexpression of Chk2 correlated only with reduced expression of p27 and telomerase. There was no difference between the overall survival and disease-free survival rates according to Chk2 status. In conclusion, Chk2 correlated with reduced expression of h-TERT and p27, but not with angiogenic factors. Chk2 expression also did not interfere in the outcome of the patients.

p63 correlates with both BRCA1 and cytokeratin 5 in invasive breast carcinomas: further evidence for the pathogenesis of the basal phenotype of breast cancer.

AIMS: To study the expression of p63, cytokeratin (CK) 5 and CK8/18 in invasive ductal carcinomas and their relationship with BRCA1 and other pathological and immunohistochemical features of clinical significance. METHODS AND RESULTS: Immunohistochemistry with the antibodies p63, CK5, CK8/18, BRCA1, oestrogen receptor, progesterone receptor, p53, c-erbB-2 and Ki67 was performed in 102 formalin-fixed paraffin-embedded samples of invasive ductal carcinomas. The CK5+ cases were submitted to a double-immunolabelling study with p63. There was a strong relationship between CK5 and p63 expression and both markers were associated with hormonal receptor-negative high-grade carcinomas with high proliferative rate. Furthermore, there was coexpression of CK5 and p63 in neoplastic cells, indicating that p63, like CK5, is a marker of the basal phenotype of breast cancer. There was a strong relationship between reduced expression of BRCA1 with both p63 and CK5 expression as well as an inverse correlation between p63 and CK8/18 expression, suggesting that loss of p63 expression is required for the transition between a basal to a luminal phenotype of breast carcinoma. CONCLUSIONS: Since p63 is thought to be a marker of stem cells and may act as an oncogene, our data support the idea that BRCA1 acts as stem cell regulator.

Hereditary hemochromatosis in a Brazilian university hospital in São Paulo State (1990-2000)

Hereditary hemochromatosis (HH) is the most common genetic disease among individuals of European descent. Two mutations (845G-->A, C282Y and 187C-->G, H63D) in the hemochromatosis gene (HFE gene) are associated with HH. About 85-90% of patients of northern European descent with HH are C282Y homozygous. The prevalence of HH in the Brazilian population, which has a very high level of racial admixture, is unknown. The aims of the present study were to identify individuals with diagnostic criteria for HH among patients with a body iron overload attended at the university hospital of the Faculty of Medicine of Ribeirao Preto from 1990 to 2000, and to evaluate the prevalence of HFE mutations. We screened first-degree relatives for HFE mutations. Four of 72 patients (three men and one woman, mean age 47 years) fulfilled the criteria for HH. HFE mutations were studied in three patients [two C282Y homozygotes (patients 1 and 2) and one H63D heterozygote]. Patient 1 had four children (all C282Y heterozygotes with no iron overload) and seven brothers and sisters: two sisters (66 and 76 years old) were C282Y homozygotes and both had an iron overload (a liver biopsy in one showed severe iron deposits), one sister (79 years old) was a compound heterozygote with no iron overload, one brother (78 years old) was a C282Y heterozygote with no iron overload, two individuals were H63D heterozygotes (one brother, 49 years old, obese, with a body iron overload and abnormal liver enzymes - a biopsy showed non-alcoholic steatohepatitis, and one 70-year-old sister with no iron overload). Patient 2 had two children (22 and 24 years old who were C282Y heterozygotes with no iron overload) but no brothers or sisters. These results showed that HH was uncommon among individuals attended at our hospital, although HFE mutations were found in all patients. Familial screening is valuable for the early diagnosis of individuals at risk since it allows treatment to be initiated before the onset of the clinical manifestations of organ damage associated with HH

The differential regulation of human telomerase reverse transcriptase and vascular endothelial growth factor may contribute to the clinically more aggressive behavior of p63-positive breast carcinomas.

p63, a p53 homologue, is a myoepithelial cell marker in the normal mammary gland but p63-positive neoplastic cells may be found in up to 11% of invasive breast carcinomas. This study aims to verify the relationship between p63 expression and several clinicopathological features and tumor markers of clinical significance in breast pathology including key regulators of the cell cycle, oncogenes, apoptosis-related proteins, metalloproteinases and their inhibitors. Immunohistochemistry with 27 primary antibodies was performed in 100 formalin-fixed paraffin-embedded samples of invasive ductal carcinomas. p63-positive cells were found in 16% of carcinomas. p63-positive carcinomas were poorly differentiated, hormone receptor-negative neoplasms with a high proliferation rate. p63 also correlated with advanced pathological stage, tumor size, and the expression of human telomerase reverse transcriptase (hTERT), tissue inhibitor of matrix metalloproteinase 1 (TIMP1) and vascular endothelial growth factor (VEGF). The expression of TIMP1 suggests that the anti-proteolytic stimuli may be preponderant in p63-positive carcinomas. hTERT activity is associated with nodal metastases and cellular proliferation. VEGF regulates angiogenesis, which is also a fundamental event in the process of tumor growth and metastatic dissemination. Thus, the differential regulation of hTERT and VEGF in p63-positive breast carcinomas may contribute to the clinically more aggressive behavior of these neoplasms.

HISTOMORPHOMETRY OF MYENTERIC PLEXUS NEURONS OF THE HORSE DESCENDING COLON AFTER EXPOSURE TO BENZALKONIUM CHLORIDE. / HISTOMORFOMETRIA DOS NEURÔNIOS DO PLEXO MIOENTÉRICO DO CÓLON DESCENDENTE DE EQÜINOS EXPOSTOS AO CLORETO DE BENZALCÔNIO.

We evaluated the effects of benzalkonium chloride (BC) on the morphometry of the myenteric plexus neurons of the descending colon in eight horses. Two animals were euthanased at day 1, two at day 3, and four at day 15. Samples of the treated intestinal segment were obtained, as well as samples of the same intestinal segment from ten untreated horses slaughtered in a meat packing plant and used for comparison. Histomorphometry of the myenteric plexus neurons was performed with an image analyzer. There was a reduction in the number of myenteric plexus neurons after treatment with BC and the remaining neurons showed smaller mean neuronal body, cytoplasm and nucleus areas than control animals, especially in animals slaughtered at day 3, whereas animals slaughtered at day 15 presented values close to those of control animals. We concluded that the myenteric plexus neurons of the horse descending colon presented smaller neuronal bodies at fifteen days after exposure to BC in comparison with controls, thus showing no signs of neuroplasticity. KEY -WORDS: Myenteric plexus. Benzalkonium chloride. Morphometry. Neuroplasticity. Horses.

Avaliaram-se os efeitos do cloreto de benzalcônio (CB) na morfometria dos neurônios do plexo mioentérico do cólon descendente de oito eqüinos. Dois animais foram sacrificados no dia 01, dois no dia 03 e quatro no dia 15. Foram colhidas amostras do segmento intestinal tratado e amostras de igual segmento intestinal de outros dez eqüinos abatidos em frigorífico, não tratados, para fins de comparação. A histomorfometria dos neurônios do plexo mioentérico foi realizada por meio de analisador de imagem. Houve uma redução no número de neurônios do plexo mioentérico após o tratamento com CB e os neurônios remanescentes apresentavam áreas médias do corpo neuronal, do citoplasma e do núcleo menores que os animais controle, principalmente aqueles que vieram a óbito no dia 03, apresentando os animais do dia 15 valores próximos aos animais controle. Concluiu-se que 15 dias após a exposição ao CB os neurônios do plexo mioentérico do cólon descendente de eqüinos apresentavam áreas dos corpos neuronais inferiores aos animais controle, portanto, sem indícios de neuroplasticidade.PALAVRAS-CHAVE: Plexo mioentérico. Cloreto de benzalcônio. Morfometria. Neuroplasticidade. Eqüino.

HISTOMORPHOMETRY OF MYENTERIC PLEXUS NEURONS OF THE HORSE DESCENDING COLON AFTER EXPOSURE TO BENZALKONIUM CHLORIDE. / HISTOMORFOMETRIA DOS NEURÔNIOS DO PLEXO MIOENTÉRICO DO CÓLON DESCENDENTE DE EQÜINOS EXPOSTOS AO CLORETO DE BENZALCÔNIO.

We evaluated the effects of benzalkonium chloride (BC) on the morphometry of the myenteric plexus neurons of the descending colon in eight horses. Two animals were euthanased at day 1, two at day 3, and four at day 15. Samples of the treated intestinal segment were obtained, as well as samples of the same intestinal segment from ten untreated horses slaughtered in a meat packing plant and used for comparison. Histomorphometry of the myenteric plexus neurons was performed with an image analyzer. There was a reduction in the number of myenteric plexus neurons after treatment with BC and the remaining neurons showed smaller mean neuronal body, cytoplasm and nucleus areas than control animals, especially in animals slaughtered at day 3, whereas animals slaughtered at day 15 presented values close to those of control animals. We concluded that the myenteric plexus neurons of the horse descending colon presented smaller neuronal bodies at fifteen days after exposure to BC in comparison with controls, thus showing no signs of neuroplasticity. KEY -WORDS: Myenteric plexus. Benzalkonium chloride. Morphometry. Neuroplasticity. Horses.

Avaliaram-se os efeitos do cloreto de benzalcônio (CB) na morfometria dos neurônios do plexo mioentérico do cólon descendente de oito eqüinos. Dois animais foram sacrificados no dia 01, dois no dia 03 e quatro no dia 15. Foram colhidas amostras do segmento intestinal tratado e amostras de igual segmento intestinal de outros dez eqüinos abatidos em frigorífico, não tratados, para fins de comparação. A histomorfometria dos neurônios do plexo mioentérico foi realizada por meio de analisador de imagem. Houve uma redução no número de neurônios do plexo mioentérico após o tratamento com CB e os neurônios remanescentes apresentavam áreas médias do corpo neuronal, do citoplasma e do núcleo menores que os animais controle, principalmente aqueles que vieram a óbito no dia 03, apresentando os animais do dia 15 valores próximos aos animais controle. Concluiu-se que 15 dias após a exposição ao CB os neurônios do plexo mioentérico do cólon descendente de eqüinos apresentavam áreas dos corpos neuronais inferiores aos animais controle, portanto, sem indícios de neuroplasticidade.PALAVRAS-CHAVE: Plexo mioentérico. Cloreto de benzalcônio. Morfometria. Neuroplasticidade. Eqüino.

Histomorphometry of myenteric plexus neurons of the horse descending colon after exposure to benzalkonium chloride / Histomorfometria dos neurônios do plexo mioentérico do cólon descendente de eqüinos expostos ao cloreto de benzalcônio

We evaluated the effects of benzalkonium chloride (BC) on the morphometry of the myenteric plexus neurons of the descending colon in eight horses. Two animals were euthanased at day 1, two at day 3, and four at day 15. Samples of the treated intestinal segment were obtained, as well as samples of the same intestinal segment from ten untreated horses slaughtered in a meat packing plant and used for comparison. Histomorphometry of the myenteric plexus neurons was performed with an image analyzer. There was a reduction in the number of myenteric plexus neurons after treatment with BC and the remaining neurons showed smaller mean neuronal body, cytoplasm and nucleus areas than control animals, especially in animals slaughtered at day 3, whereas animals slaughtered at day 15 presented values close to those of control animals. We concluded that the myenteric plexus neurons of the horse descending colon presented smaller neuronal bodies at fifteen days after exposure to BC in comparison with controls, thus showing no signs of neuroplasticity. KEY -WORDS: Myenteric plexus. Benzalkonium chloride. Morphometry. Neuroplasticity. Horses.

Avaliaram-se os efeitos do cloreto de benzalcônio (CB) na morfometria dos neurônios do plexo mioentérico do cólon descendente de oito eqüinos. Dois animais foram sacrificados no dia 01, dois no dia 03 e quatro no dia 15. Foram colhidas amostras do segmento intestinal tratado e amostras de igual segmento intestinal de outros dez eqüinos abatidos em frigorífico, não tratados, para fins de comparação. A histomorfometria dos neurônios do plexo mioentérico foi realizada por meio de analisador de imagem. Houve uma redução no número de neurônios do plexo mioentérico após o tratamento com CB e os neurônios remanescentes apresentavam áreas médias do corpo neuronal, do citoplasma e do núcleo menores que os animais controle, principalmente aqueles que vieram a óbito no dia 03, apresentando os animais do dia 15 valores próximos aos animais controle. Concluiu-se que 15 dias após a exposição ao CB os neurônios do plexo mioentérico do cólon descendente de eqüinos apresentavam áreas dos corpos neuronais inferiores aos animais controle, portanto, sem indícios de neuroplasticidade.PALAVRAS-CHAVE: Plexo mioentérico. Cloreto de benzalcônio. Morfometria. Neuroplasticidade. Eqüino.

Trends of accuracy of clinical diagnoses of the basic cause of death in a university hospital.

AIMS: To determine the agreement between clinical and necropsy diagnoses of the basic cause of death, and to compare the results with those obtained in a previous study carried out at the same university hospital. METHODS: In total, 4828 necropsies, performed between 1990 and 1995 in the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil, were reviewed. Examinations were concluded at the macroscopic part of the necropsy in nearly 35% of the cases. Statistical analysis was carried out using the kappa coefficient comparing the clinical diagnosis and the diagnosis obtained after necropsy. The jackknife method was used to identify comparable kappa values for the comparison of the two periods. RESULTS: Compared with the 1978-80 period, a significant increase in diagnostic agreement was seen for the group submitted to complete necropsy, whereas no similar increase was detected when only the macroscopic step was analysed. CONCLUSIONS: There was a discrete tendency to an improved correlation between clinical and postmortem data stated by full necropsy analysis. The findings show that microscopic analysis remains important to confirm the cause of death in many cases. Diagnostic discrepancies remained high, and therefore complete necropsy continues to be an essential instrument for the assessment of clinical diagnosis.

Does the correlation between EBNA-1 and p63 expression in breast carcinomas provide a clue to tumorigenesis in Epstein-Barr virus-related breast malignancies?

Several investigators have identified Epstein-Barr virus (EBV) particles in breast carcinomas, a fact that supports a role for EBV in mammary tumorigenesis. The possible mechanism involved in this process is not clear. The present study was carried out in an attempt to determine whether there is a relationship between latent infection with EBV and p53 and p63 expression in breast carcinomas. Immunohistochemistry developed with 3.3-diaminobenzidine tetrahydrochloride was performed in 85 formalin-fixed paraffin-embedded breast carcinomas using anti-EBV EBNA-1, anti-p63, anti-p53, anti-estrogen receptor (ER) and anti-progesterone receptor (PR) antibodies. The cases were selected to represent each of the various histologic types: intraductal carcinoma (N = 12), grade I invasive ductal carcinoma (N = 15), grade II invasive ductal carcinoma (N = 15), grade III invasive ductal carcinoma (N = 15), tubular carcinoma (N = 8), lobular carcinoma (N = 10), and medullary carcinoma (N = 10). The ductal breast carcinomas were graded I, II and III based on the Scarff-Bloom and Richardson grading system modified by Elston and Ellis. One slide containing at least 1000 neoplastic cells was examined in each case. ER, PR, p63, p53 and EBNA-1 were positive in 60, 40, 11.8, 21.2 and 37.6 percent of carcinomas, respectively. There was a correlation between EBNA-1 and p63 expression (P < 0.001), but not between EBNA-1 and p53 (P = 0.10). These data suggest a possible role for p63 in the mammary tumorigenesis associated with Epstein-Barr virus infection.

Does the correlation between EBNA-1 and p63 expression in breast carcinomas provide a clue to tumorigenesis in Epstein-Barr virus-related breast malignancies?

Several investigators have identified Epstein-Barr virus (EBV) particles in breast carcinomas, a fact that supports a role for EBV in mammary tumorigenesis. The possible mechanism involved in this process is not clear. The present study was carried out in an attempt to determine whether there is a relationship between latent infection with EBV and p53 and p63 expression in breast carcinomas. Immunohistochemistry developed with 3.3-diaminobenzidine tetrahydrochloride was performed in 85 formalin-fixed paraffin-embedded breast carcinomas using anti-EBV EBNA-1, anti-p63, anti-p53, anti-estrogen receptor (ER) and anti-progesterone receptor (PR) antibodies. The cases were selected to represent each of the various histologic types: intraductal carcinoma (N=12), grade I invasive ductal carcinoma (N=15), grade II invasive ductal carcinoma (N=15), grade III invasive ductal carcinoma (N=15), tubular carcinoma (N=8), lobular carcinoma (N=10), and medullary carcinoma (N=10). The ductal breast carcinomas were graded I, II and III based on the Scarff-Bloom and Richardson grading system modified by Elston and Ellis. One slide containing at least 1000 neoplastic cells was examined in each case. ER, PR, p63, p53 and EBNA-1 were positive in 60, 40, 11.8, 21.2 and 37.6% of carcinomas, respectively. There was a correlation between EBNA-1 and p63 expression (P<0.001), but not between EBNA-1 and p53 (P=0.10). These data suggest a possible role for p63 in the mammary tumorigenesis associated with Epstein-Barr virus infection.