Hepatic lesions in protein-deficient adult rats

Four groups of 10 young adult Wistar male rats were fed ad libitum on a protein-free diet for periods of 7, 28, 56 and 84 days. Control groups were fed on a 20% casein diet. Food intake and body weights of rats were registered. Plasma protein levels and liver weight and fat content were determined. Sections of the caudate lobe were studied histologically. Fatty changes were classified in three grades. Protein-deficient rats exhibited loss of body weight and had low levels of plasma protein concentration. Liver lost weight after 7 days of protein deficiency; there was a gradual reduction in liver weight as periods of protein deprivation were longer. After 7 days, liver fat concentration was not significantly higher than in the respective control group; it was significantly higher in all the other malnourished animals, As periods of protein deprivation were longer, fatty changes became more severe. Other hepatic lesions were found in 5 of the 10 rats submitted to the longest period of protein deficiency. One of the rats showed a diffuse cellular atrophy, 2 animals showed an extensive haemorrhagic necrosis, another showed a focal area of reticulum collapse and the last exhibited a distortion of the normal architecture of the liver due to diffuse reticulum collapse and early nodular regeneration; these 2 last rats showed early fibrosis in portal areas. The findings suggest that other deficiencies may complicate the protein deficiency when rats are given a protein-free diet over prolonged periods. Even if the protein-deficient diet has protective nutrients, it may be that, when rats eat less food, as occurs in prolonged experiments deficiency of one or all of these elements can occur, depending on their relative amount in diet.

Primary cutaneous amyloidosis: Clinical, laboratorial and histopathological study of 25 cases. Identification of gammaglobulins and C3 in the lesions by immunofluorescence

25 cases of primary cutaneous amyloidosis are studied. 16 patients had macular amyloidosis (MPA) and 9 lichen amyloidosus (LPA). γ-Globulins were increased in 50% of the patients. IgG and IgA were increased in the serum of 5 and 3 patients with MPA and 4 and 2 patients with LPA, respectively. Volume of amyloid deposits was similar in both forms. By direct immunofluorescence we demonstrated IgG in the amyloid deposits of 21 of the 25 cases and C3 in 13; IgM was present in 9 cases of MPA and in 3 cases of LPA. MPA was more frequent than LPA; histologically, it was impossible to distinguish MPA from LPA; correlation between serum levels of γ-globulins and their presence in amyloid deposits was weak; MPA and LPA seem to be distinct clinical manifestations of the same disease and itching does not cause transformation of MPA in LPA.

Effect of non-steroidal anti-inflammatory drugs (NSAID) on the histamine release induced by compound 48/80 and cardiac anaphylaxis in guinea-pig isolated heart

Histamine release from guinea pig heart treated with compound 48/80 was potentiated by the cyclooxygenase inhibitors indomethacin and piroxicam but not by aspirin or phenylbutazone. This differential effect suggests that the potentiation is not merely due to an inhibition of prostaglandin synthesis. Piroxicam potentiated the histamine release induced by cardiac anaphylaxis whereas indomethacin reduced this effect. The SRS-A antagonist FPL 55712 inhibited histamine release induced by cardiac anaphylaxis, but not that evoked by compound 48/80, and also prevented the potentiation due to indomethacin and piroxicam. In total, these data suggest that the potentiation of histamine release by piroxicam and indomethacin is probably due to a diversion of arachidonic acid metabolism from the cyclooxygenase to the lipoxygenase pathways. The resulting lipoxygenase products may then regulate histamine release, with the secretion due to antigen being more sensitive to such modulation than that evoked by compound 48/80.

Experimental pulmonary paracoccidioidomycosis in the Syrian hamster: morphology and correlation of lesions with the immune response.

A model for pulmonary paracoccidioidomycosis in the hamster is described. The disease was induced by intratracheal inoculation of 1.7 x 10(5) viable yeast forms of P. brasiliensis. Lung histopathology, dissemination lesions and humoral and cellular immune responses were investigated at intervals up to 24 weeks after infection. Humoral immunity was studied by immunodiffusion and complement fixation tests. Cell-mediated immunity was evaluated in vitro by the macrophage migration inhibition test in the presence of phytohaemagglutinin and P. brasiliensis soluble antigen, and in vivo by the paracoccidioidin test. Thirty out of 35 infected animals (85.7%) developed pulmonary paracoccidioidomycosis. Dissemination lesions were observed in regional lymph nodes (82.8%), liver (8.5%) and spleen (5.7%). Lung involvement was mainly around bronchi and vessels. Regional lymph nodes were severely involved from the fourth week on, acquiring a pseudotumoral aspect at later stages. Specific antibodies were detected from the fourth week on, with titres increasing progressively. The cellular immune response to phytohaemagglutinin was intact throughout the experiment and the response to P. brasiliensis antigen was already detectable by the second week and remained positive to the end of the experiment. The skin test became positive from the fourth week on. Inoculation by the intratracheal route represents a highly effective way of infecting hamsters with P. brasiliensis, with the induction of localized disease, good antibody production and intact cell immunity.

Is coronary sinus blood oxygen tension behavior determined by myocardial oxygen tension variation during cardiac reperfusion?

The relationship between coronary sinus blood oxygen tension (CSPO 2) and myocardial oxygen tension (MPO 2) variations during cardiac ischemia and reperfusion was studied in anesthetized open-chest dogs. Oxygen tension was measured by a polarographic method. Ischemia resulted in a slightly decreased CSPO 2 and a more pronounced reduction of MPO 2. After reperfusion the CSPO 2 rose rapidly and transiently before it returned gradually to the control level. By contrast, during the recovery period, the MPO 2 increased slowly, with recovery occurring long after the peak of CSPO 2. These data suggest that during the reperfusion phase, the CSPO 2 variation is probably due to opening of the myocardial arteriovenous shunts instead of an increase of flow through the myocardial capillary bed.

On the cardiac control in the South American lungfish, Lepidosiren paradoxa

1. 1. The mechanisms behind cardiac control were investigated in the South American lungfish, Lepidosiren paradoxa, using fish with chronically implanted cannulae and electromagnetic flow probes. In addition, a preliminary study was made of the cardiovascular events associated with air breathing. 2. 2. The study suggests that the heart of Lepidosiren is controlled by cholinergic vagal fibres which, in some animals, exert a tonic influence in the resting fish. Cyclic changes in heart rate in association with air breaths is due to modulation of this cholinergic tonus. 3. 3. In addition to the variable cholinergic tonus, there appears to be a relatively stable adrenergic tonus on the heart, which causes an elevated heart rate. The adrenergic tonus is likely to be due to local release of catecholamines from endogenous chromaffin cells within the atrium. 4. 4. Preliminary results suggest that pulmonary arterial flow increases by about 50% immediately following an air breath. The mechanism behind this increase probably involves both an elevation of the heart rate and a redistribution of blood flow into the pulmonary circuit. © 1989.

Paracoccidioidomicose: estudo radiológico e pulmonar de 58 casos

Spirometric and haemogasimetric tests were performed in 52 patients with unifocal and multifocal progressive Paracoccidioidomycosis pulmonary diseases, in 5 patients with juvenile and 1 female internal genital forms. The age ranged from 20 to 74 years old and the duration of disease from 3 to 25 years. Dyspnea, cough, tegumentary and lymphatic manifestations were the most predominant signs observed. Fourteen of them was developed Cor pulmonale. Impaired renal function was recorded in 19 patients, cardiac symptoms were described in 7 and hyporeactor adrenal activity was showed in 13 patients. Radiological studies demonstrated mild in 16, moderate in 24 and severe pulmonary lesions types in 18 patients. The pulmonary function revealed: normal spyrographic findings in 17, pure obstructive type in 32 and mixed form in 9 of them. Hyperventilation was described in 54 individuals and all of them showed an increasing of the alveolo-arterial difference. PaO2 less than 80 mm/Hg observed in 36 of them. Statistical analysis demonstrated significative association between clinical evolution and radiological interpretation. Similar data were obtained in radiology evaluations, clinical evolutive studies and pulmonary functions described in these patients. The granulomatous reaction due to Paracoccidioidomycosis, in heavy smokers patients, gave origin to the alterations in small airways predisposing the interalveolar dissemination an impaired alveolo-arterial diffusion.

Commissural nucleus of the solitary tract lesions reduce food intake and body weight gain in rats

This study investigated the effects of an electrolytic lesion of the commissural subnucleus of the nucleus of the solitary tract (commNTS) on bodyweight, daily food and water intake, and plasma glucose and insulin in rats. In the first 6 days following brain surgery, commNTS lesioned rats reduced daily food intake by 80% compared to rats with sham lesions. After this period rats with lesions of commNTS started recovering food intake, but intake remained significantly reduced until the 12th day after surgery. A reduction in body weight was observed 4 days after surgery and reached a maximum on the 12th day. After this, a partial recovery of body weight was observed, but weight remained significantly reduced compared to weights of rats with sham lesions through the conclusion of the study. Food intake and body weight gain in other rats with partial lesions of the commNTS or with lesions outside the commNTS did not differ from rats with sham lesions with regard to those variables. Daily water intake and plasma glucose and insulin were not changed by the commNTS lesions. These results suggest that commNTS is involved with mechanisms that control food intake and body weight in rats.

Potentially malignant epithelial oral lesions: Discrepancies between clinical and histological diagnosis

OBJECTIVE: To evaluate the discrepancy index between the clinical and histological diagnosis and the prevalence of epithelial dysplasia and carcinoma in 45 patients with potentially malignant epithelial oral lesions (PMEL). PATIENTS AND METHODS: We submitted 45 patients with PMEL to clinical examination and obtained a biopsy from each. The results of histological diagnosis were compared to the clinical diagnosis. RESULTS: Clinical diagnosis showed that the most common PMEL was leukoplakia followed by lichen planus and by actinic cheilitis associated with leukoplakia. The most common site was the buccal mucosa. Histological diagnosis revealed that 46.7% of the PMEL were lichen planus. The discrepancy index between clinical and histological diagnosis was 24.4%. The higher discrepancy index occurred among leukoplakias. The prevalence of epithelial dysplasia and carcinoma was 17.8%. CONCLUSIONS: We conclude that all PMEL should be submitted to a microscopic analysis because the discrepancy between clinical and histological diagnosis was present in a quarter of these lesions. Otherwise, the epithelial dysplasia and carcinoma were more frequent in the leukoplakias.

Pulpal lesions in normal and cyclosporin a treated rats

The objective of this study was to examine the development of pulpal lesions in the lower molar of control and cyclosporin A (CyA) treated rats. The pulps of the first lower molars of 20 normal and 20 CyA treated rats were exposed and left open into the oral cavity. Five animals of each group were killed at 7, 14, 21, and 28 days after the pulp exposure. The specimens were sectioned sagittally at a thickness of 7 μm and stained with hematoxylin and eosin. The pulpal lesions were similar for both normal and CyA treated rats in all studied periods and the differences between both groups were not statistically significant by the Student t test at the 5% (0.05) level of significance, indicating that the immunosuppression did not alter the evolution of the inflammatory process. Copyright © 1997 by The American Association of Endodontists.

Clonal chromosome abnormalities found in three non-neoplastic proliferative brain lesions

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

Commissural NTS lesions and cardiovascular responses in aortic baroreceptor-denervated rats

Both acute (1 day) lesions of the commissural nucleus of the solitary tract (commNTS) and aortic baroreceptor denervation increase pressor responses to bilateral common carotid occlusion (BCO) during a 60-second period in conscious rats. In this study, we investigated the following: (1) the effects of commNTS lesions on basal mean arterial pressure (MAP) and heart rate (HR) of aortic denervated (ADNx) rats; (2) the effects of acute commNTS lesions on pressor responses to BCO in ADNx rats; and (3) the effects of chronic (10 days) commNTS lesions on the pressor response to BCO. ADNx increased basal MAP and HR in sham-lesioned rats. Acute commNTS lesions abolished the MAP and HR increases observed in ADNx rats. Acute commNTS lesions increased the pressor responses to BCO in rats with intact- baroreceptor innervation but produced no additional change in the pressor response to BCO in ADNx rats. Chronic commNTS lesions did not change the pressor responses to BCO in rats with intact-baroreceptor innervation. The data show that acute commNTS lesions abolish the MAP increase produced by aortic baroreceptor denervation. They also suggest that acute commNTS lesions enhance the pressor response to BCO by partial withdrawal of aortic baroreceptor inputs into the NTS. Chronically, reorganization in the remaining aortic baroreceptor or in the baroreflex function as a whole might produce normalization of the cardiovascular responses to BCO.