Morphologic and morphometric evaluation of pancreatic islets in chronic Chagas' disease

PURPOSE: Hyperglycemia and abnormal glucose tolerance tests observed in some patients with chronic Chagas' disease suggest the possibility of morphological changes in pancreatic islets and/or denervation. The purpose of this study was to describe the morphology and morphometry of pancreatic islets in chronic Chagas' disease. METHODS: Morphologic and computerized morphometric studies were performed in fragments of the head, body, and tail regions of the pancreas obtained at necropsies of 8 normal controls and 17 patients with chronic Chagas' disease: 8 with the digestive form (Megas) and 9 with the congestive heart failure form. RESULTS: The Megas group had a larger (p < 0.05) pancreatic islet area in the tail of the pancreas (10649.3 ± 4408.8 µm²) than the normal control (9481.8 ± 3242.4 µm²) and congestive heart failure (9475.1 ± 2104.9 µm²) groups; likewise, the density of the pancreatic islets (PI) was greater (1.2 ± 0.7 vs. 0.9 ± 0.6 vs. 1.9 ± 1.0 PI/mm², respectively). In the tail region of the pancreas of patients with the Megas form, there was a significant and positive correlation (r = +0.73) between the area and density of pancreatic islets. Discrete fibrosis and leukocytic infiltrates were found in pancreatic ganglia and pancreatic islets of the patients with Chagas' disease. Trypanosoma cruzi nests were not observed in the examined sections. Individuals with the Megas form of Chagas' disease showed increased area and density of pancreatic islets in the tail of the pancreas. CONCLUSION: The observed morphometric and morphologic alterations are consistent with functional changes in the pancreas, including glycemia and insulin disturbances.

Pancreatic lesions in acute experimental Chagas' disease

BACKGROUND: Chagas' disease is an endemic tropical affliction found from southern United States to Argentina. The acute phase of this disease is difficult to study in man because the symptoms are non-specific and most cases require no medical assistance. Experimental models have been developed for sequential studies, and intense parasitism in all organs and tissues, including the pancreas, have been detected in the acute phase. PURPOSE: To evaluate the involvement of the pancreas in acute experimental Chagas' disease in a mouse model by histopathological characterization. CASUISTIC AND METHODS: Ten BALBc mice, about 20 g, injected i.p. with 100 000 forms of the Y strain of Trypanosoma cruzi were used. The animals were sacrificed after 14 days of infection. Fragments of pancreas were processed by conventional paraffin embedding and hematoxylin-eosin staining. RESULTS: Ruptured pseudocysts and release of parasites to the extracellular medium caused by necrosis of acinar and duct cells and foci of fat were the most striking histopathological features of acute Chagasic pancreatitis. CONCLUSION: Parasitism is the main cause of acute pancreatitis in Chagas' disease.

Umbilical mass as the sole presenting symptom of pancreatic cancer: a case report

Umbilical nodes are rare. The metastatic involvement of the region was first described in 1846. Sister Mary Joseph was the first observer to establish the correlation between carcinomas and umbilical nodes. The umbilical node may be the sole presenting sign of cancer and is usually associated with advanced disease and poor prognosis. A 64-year-old woman, previously healthy, presented vague abdominal discomfort and a hard umbilical nodule for 1 week, which was first diagnosed as an incarcerated umbilical hernia. She underwent a new clinical assessment and biopsy. After immunohistochemical analysis and computerized tomography, she was diagnosed with pancreatic cancer. The clinical staging showed advanced disease with distant metastasis. She received palliative chemotherapy. After 8 months, she was alive in poor clinical condition. Clinical suspicion should lead to a careful additional evaluation whenever an umbilical nodule presents with malignant signs.

Selective serotonin-reuptake inhibitor and norepinephrine dopamine reuptake inhibitor antidepressants do not affect natural killer cell activity in vitro

OBJECTIVE: This study aims to evaluate the citotoxic activity of two commonly used anti-depressants: paroxetine and bupropion. We also evaluated the in vitro natural killer activity (NKA) after incubating the blood samples with the antidepressants. METHODS: Peripheral blood samples from 15 healthy volunteers were collected and the mononuclear cells (PBMCs) were isolated and incubated for 24h with (or without = control cells) paroxetine and bupropion, in concentrations of 30, 100 and 1000 ng/ml. After the incubation period in both groups, the amount of dead cells was calculated using trypam blue technique. NKA was evaluated using the classic51Cr release assay. CONCLUSIONS: PBMCs dead cells occurred in both groups and in proportion to all pharmacological concentrations. Nevertheless, the NKA was not affected, even with the reduction in the number of effective cells.

Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

Mitral valve repair with a malleable bovine pericardium ring

OBJECTIVE: To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and echodopplercadiographic results. METHODS: Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4±17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS: The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On echodopplercardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had seigre insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION: Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.

Concomitant Use of Glycoprotein IIb/IIIa Inhibitor and Streptokinase after Unsuccessful Rescue Angioplasty

A 38-year-old man with acute myocardial infarction in the lower wall affecting the right ventricle underwent thrombolytic treatment with streptokinase. Approximately 2 hours after the thrombolytic treatment started, he presented with signs of coronary reocclusion. He underwent emergency cineangiocoronariography that revealed that his right coronary artery was completely occluded by a clot. He unsuccessfully underwent angioplasty and stent implantation. After the concomitant use of glycoprotein IIb/IIIa inhibitor, coronary TIMI III flow was achieved without additional dilations, and he was discharged from the hospital 5 days later with no further complications.

Detection of viral infection by immunofluorescence in formalin-fixed tissues, pretreated with trypsin

The presence of viral antigen in sections from formalin-fixed and paraffin-embedded human tissues was demonstrated by trypsin digestion followed by direct or indirect immunofluorescence. The specimens may be used for retrospective diagnosis. The immunofluorescence technique has to be adapted to the suspected virus infection on the basis of previous histopathology study. Variations of trypsin concentration time and temperature of incubation, expose different viral antigens and have to be previously tested for each unknown system. For measles virus detection in lung a stronger digestion has to be applied as compared to adenovirus or respiratory disease viruses in the same tisue. Flavivirus in liver tissue needs a weaker digestion. The reproducibility of the method makes it useful as a routine technique in diagnosis of virus infection.

Extrachromosomal nucleic acids in bovine babesia

Two kinds of small extrachromosomal nucleic acid elements were found in the bovine babesias, Babesia bovis and B. bigemina. One element with an apparent size of 5.5 kilobase pairs (kbp) is a double stranded RNA related to virus like particles. Another molecule is a double stranded DNA with a molecular size of about 6.2 kbp. Southern blot comparison of restriction DNA fragments of the latter molecule, which is present in both B. bovis and B. bigemina is described.

Development of a vaccine strategy against human and bovine schistosomiasis: background and update

Schistosomiasis is a chronic and debilitating parasitic disease that affects over 200 million people throughout the world and causes about 500,000 deaths annually. Two specific characteristics of schistosome infection are of primordial importance to the development of a vaccine: schistosomes do not multiply within the tissues of their definitive hosts (unlike protozoan parasites) and a partial non-sterilizing immunity can have a marked effect on the incidence of pathology and on disease transmission. Since viable eggs are the cause of disease pathology, a reduction in worm fecundity whether or not accompanied by a reduction in parasite burden is a sufficient goal for vaccine induced immunity. We originally showed that IgE antibodies played in experimental models a pivotal role for the development of protective immunity. These laboratory findings have been now confirmed in human populations. Following the molecular cloning and expression of a protein 28 kDa protein of Schistosoma mansoni and its identification as a glutathion S-transferase, immunization experiments have been undertaken in several animal species (rats, mice, baboons). Together with a significant reduction in parasite burden, vaccination with Sm28 GST was recently shown to reduce significantly parasite fecundity and egg viability leading to a decrease in liver pathology. Whereas IgE antibodies were shown to be correlated with protection against infection, IgA antibodies have been identified as one of the factors affecting egg laying and viability. In human populations, a close association was found between IgA antibody production to Sm28 GST and the decrease of egg output. The use of appropriate monoclonal antibody probes has allowed the demonstration that the inhibition of parasite fecundity following immunization was related to the inhibition of enzymatic activity of the molecule. Epitope mapping of Sm28 GST has indicated the prominent role of the N and C terminal domains. Immunization with the corresponding synthetic peptides was followed by a decrease of 70% of parasite fecundity and egg viability. As a preliminary step towards phase I human trials, vaccination experiments have been performed in cattle, a natural model for Schistosoma bovis. Vaccination of calves with the S. bovis GST has led to a reduction of ever 80% of egg output and tissue egg count. Significant levels of protection were also observed in goats after immunization with the recombinant S. bovis GST. Increasing evidence of the participation of IgA antibodies in protective immunity has prompted us toward the development of mucosal immunization. Preliminary results indicate that significant levels of protection can be achieved following oral immunization with live attenuated vectors or liposomes. These studies seem to represent a promising approach towards the future development of a vaccine strategy against one of major human parasitic diseases.

A role for lymphocytes and cytokines on the eosinophil migration induced by LPS

In the present work we review the existing evidence for a LPS-induced cytokine-mediated eosinophil accumulation in a model of acute inflammation. Intrathoracic administration of LPS into rodents (mice, rats or guinea pigs) induces a significant increase in the number of eosinophils recovered from the pleural fluid 24 hr later. This phenomenon is preceded by a neutrophil influx and accompanied by lymphocyte and monocyte accumulation. The eosinophil accumulation induced by LPS is not affected by inhibitors of cyclo or lipoxygenase nor by PAF antagonists but can be blocked by dexamethasone or the protein synthesis inhibitor cycloheximide. Transfer of cell-free pleural wash from LPS injected rats (LPS-PW) to naive recipient animals induces a selective eosinophil accumulation within 24 hr. The eosinophilotactic activity present on the LPS-PW has a molecular weight ranging between 10 and 50 kDa and its effect is abolished by trypsin digestion of the pleural wash indicating the proteic nature of this activity. The production of the eosinophilotactic activity depends on the interaction between macrophages and T-lymphocytes and its effect can not be blocked by anti-IL-5 monoclonal antibodies. Accumulated evidence suggest that the eosinophil accumulation induced by LPS is a consequence of a eosinophilotactic cytokine produced through macrophage and T-cell interactions in the site of a LPS-induced inflammatory reaction.

Polymerase chain reaction amplification of genomic fragments of bovine herpesvirus-1

Especial conditions were developed for the amplification of five DNA segments from US region of BHV-1 by polymerase chain reaction. In order to eliminate most nonspecific products it was found that addition of three cosolvents DMSO, glycerol and NP 40 was a simple method for increasing the specificity of amplification.

Mycobacterium bovis: polymerase chain reaction identification in bovine Lymphonode biopsies and genotyping in isolates from Southeast Brazil by spolygotyping and restriction fragment length polymorphism

Diagnosis of the Mycobacterium tuberculosis complex by direct PCR of mediastinal lymphnode DNA and microbiological tests were compared in cattle suspicious of bearing tuberculous-like lesions detected during slaughter. The PCR procedure applied on DNA samples (n=54) obtained by adding alpha -casein into the thiocyanate extraction mix was positive in 70% of the samples. PCR confirmed the identification of 23 samples (100%) that grew in culture, 9 samples (60%) that failed to grow in culture, plus 6 (37.5%) samples that resulted in growth of bacterial contaminants. Genotyping by IS6110-RFLP and DR-spoligotyping analysis of seven samples revealed the presence of several polimorphisms. Seven of the isolates contained multiple copies of IS6110, thus defining the existence of five singular genotypes.