RESUMO
We investigated the effect of different doses of cyclosporin A (CyA) on glucose and insulin levels, as well as its residual effects on pancreatic islets ultrastructure after discontinuation of the drug. We studied four groups of Wistar rats. One control- (n = 5) and three experimental groups, n = 10 each, were treated with different doses of CyA i.m. for 14 days: group I, 5 mg/Kg; group II, 15 mg/Kg; and group III, 25 mg/Kg. Five animals of each group were sacrificed after 14 days, and the remaining five after 21 days to assess residual CyA effects. On the day of sacrifice, the rats underwent maltose absorption test, and glucose and insulin levels were measured. Pancreatic biopsies were obtained on day 21 to evaluate islets ultrastructure by electron microscopy. As a result, statistically significant, dose dependent (P < 0.05) increases in glucose and insulin levels were observed in CyA-treated groups. Groups II and III showed insulin levels significantly higher after fasting (P < 0.05) on day 14 comparing to the controls, while in groups I and II values returned to normal after CyA discontinuation. Group III showed persistently increased insulin levels on day 21. Pancreatic ultrastructural changes were observed only in group III. We can conclude that CyA effects on glucose and insulin levels were temporary and reversible at low doses. Ultrastructural changes in the pancreatic islets may occur with high doses of CyA.
Assuntos
Ciclosporina/farmacologia , Imunossupressores/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Animais , Ciclosporina/administração & dosagem , Relação Dose-Resposta a Droga , Glucose/metabolismo , Imunossupressores/administração & dosagem , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Microscopia Eletrônica , Ratos , Ratos WistarRESUMO
BACKGROUND/AIMS: The aim of this work is to evaluate the repair of mucosal epithelium at the critical time of the beginning of reepithelization of stomach wound. METHODOLOGY: Structural and ultrastructural evaluation of rat gastric mucosa repair was carried out with administration of placebo, cimetidine and pentagastrin in different groups of rats (Rattus norvegicus albinus) during the first 7 post-operative days. Following 48 hours of starvation and anesthesia by ethyl ether inhalation, the animals were submitted to laparotomy exposing the stomach. A fusiform gastric resection measuring 5 mm in length was performed in the fundus stomach wall. The surgical wound was sutured in 2 plans: muscular tunic and visceral serosa. The abdominal wall was also sutured in 2 plans: parietal serosa-abdominal musculature and skin. During 6 consecutive post-operative days, the placebo group rats received 1 ml of distilled water intragastrically; those of the cimetidine group 10 mg/kg of cimetidine; and, animals of the pentagastrin group, 250 micrograms/kg of pentagastrin by intraperitoneal injection. On the 7th post-operative day, rats were killed and fragments of the stomach wall containing transverse section of surgical wound were collected and processed for light microscopy and electron microscopies. RESULTS: At the beginning of gastric mucosal wound reepithelization cimetidine has better effect than that of pentagastrin. CONCLUSIONS: Comparative mucosal morphology showed that cimetidine tends to accelerate the beginning of reepithelization of granulation tissue while pentagastrin delays reepithelization due to alteration of protective mucus and a provoking increase of granulation tissue.
Assuntos
Cimetidina/farmacologia , Mucosa Gástrica/patologia , Tecido de Granulação/efeitos dos fármacos , Antagonistas dos Receptores H2 da Histamina/farmacologia , Pentagastrina/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Células Epiteliais/patologia , Masculino , Ratos , Ratos WistarRESUMO
We studied five patients with hairy cell leukemia (HCL) diagnosed within the last ten years at the Department of Hematology of Universidade Federal de São Paulo-Escola Paulista de Medicina. Our purpose was to analyze the value of transmission electron microscopy (TEM) by comparing this method with the conventional ones. At diagnosis, patients presented weight loss, spleen enlargement and hairy cells (HC) in peripheral blood and bone marrow slides. HC was characterized by morphology and tartrate test resistance in the acid phosphatase reaction (TRAP). At the evaluation time, the amount of HC ranged from 1% to 85% of WBC count. All patients, except two, had phenotype B. In these last two, TRAP as well as phenotype B could not be documented due to low HC numbers in their exams. Cytoplasmatic projections and the absence of lamellar ribosomic complex were the most frequent ultrastructural findings, even in those patients with the lowest HC numbers. Based on these features, TEM is an efficient method for searching for HC at HCL diagnosis and during the course of the disease.
Assuntos
Leucemia de Células Pilosas/patologia , Idoso , Idoso de 80 Anos ou mais , Contagem de Células Sanguíneas , Feminino , Histocitoquímica , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Persistent diarrhea very often leads children to malnutrition. It has become the major cause of death resulting from acute diarrhea episodes in developing countries. In order to determine the ultrastructural alterations of the small bowel that occur in the syndrome, 16 infants with severe persistent diarrhea were studied, utilizing light microscopy and the scanning electron microscope. Stool and jejunal fluid samples were collected for culture, rotavirus, ova and parasite search. Enteropathogenic agents were isolated in stools from 11 (68.7%) patients and bacterial proliferation in the small bowel was detected in 11 (68.7%) patients. EPEC strains were the most frequent enteropathogenic agent isolated both from stool and jejunal fluid cultures. The stool cultures revealed the presence of the following enteropathogenic microorganisms: EPEC 0111 in four, EPEC 0119 in one, EAggEC in five, Shigella flexneri in two, and Shigella sonnei in one; mixed infections due to EAggEC associated with EPEC 0111 were seen in two patients. The light microscopic analysis revealed that 56.2% of the patients suffered moderate villous atrophy most frequently associated with effacement of the microvilli, intracytoplasmatic vacuolization, increased number of multivesicular bodied and increased lymphocytic and eosinophylic infiltration in the lamina propria. The scanning electron microscopic analysis revealed in all cases shortening of the villi and enterocyte derangements; very often there was a total lack and/or effacement of the microvilli; in half of the patients there was a mucoid material covering the enterocytes tightly adhered to the apical epithelium surface. The scanning ultrastructural alterations observed in these patients are probably due to an association of factors brought about by the presence of enteropathogenic microorganisms and the resulting food intolerance that is responsible for perpetuation of diarrhea.