[Radiograph of a Bochdalek hernia].
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Biomedical subjects
Publications and source records attributed to J F Muñoz.
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The immunopathogenesis of AIDS is associated with the development of opportunistic infections by intracellular pathogens that can invade and reproduce freely because of impaired cellular functions. Neutrophils from asymptomatic human immunodeficiency virus (HIV) type 1-infected persons and from symptomatic patients with AIDS were found to retain normal phagocytosis activity while producing significantly less superoxide than neutrophils from HIV-1-negative subjects, when stimulated through Fc receptors or protein kinase C. After priming with a synthetic HIV-1 envelope peptide and stimulation via the Fc receptor, the neutrophils from HIV-1-negative controls had suppressed superoxide production, reduced phosphorylation of two unidentified cellular proteins, and increased expression of a third phosphoprotein. These results suggest that HIV-1 can produce direct functional damage of neutrophils through binding of envelope components to the cell membrane.
BACKGROUND: Study of antifungal sensitivity can help in treatment screening and evaluation of patients suffering from some fungal infections. The purpose of this study is to compare fluconazole MICs obtained by E-test and agar dilution with the NCCLS method. MATERIAL AND METHODS: The in vitro activity of fluconazole against 158 yeast strains by three systems: E-test, agar dilution and the microbroth NCCLS M27P method. RESULTS AND CONCLUSION: A correlation between 84 to 100% was observed the degree varying in the result among different species. The E-test was found to be comparable to the NCCLS M27P microbroth method, was easier to perform and provides MIC result for Candida species within 24 h.
The E test is a quantitative technique for determining antimicrobial susceptibility; it is based on the diffusion of a stable predetermined gradient of a specific antifungal agent along an inert plastic strip which is applied to a solid culture medium. The E test is an alternative method for determining inhibitory concentrations of antimicrobial agents. The aim of the present study was to determine the in vitro susceptibility of different yeasts to 5 antifungal agents using the E test. The antifungal susceptibility of 87 strains, 73 of which were yeasts obtained from clinical samples, 11 were Prototheca strains and 3 controls, were examined using a gradient diffusion technique (E test). Of these isolates, 13% of Candida albicans were resistant to flucytosine, and 20%, 17% and 33% showed resistance to ketoconazole, itraconazole and fluconazole, respectively. All Candida krusei isolates showed resistance to flucytosine and fluconazole. The Candida parapsilosis and Candida tropicalis strains all presented in vitro susceptibility to all the agents tested. Prototheca strains were only susceptible in vitro to amphotericin B. It was found that the E test was easy to perform, and provided MIC values similar to those obtained with other well documented techniques. It was therefore concluded that the E test could be implemented as a standard procedure in clinical mycology laboratories.
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OBJECTIVE: To evaluate our application of indications, use and benefits of conventional hemodialysis during surgery in patients with advanced liver disease and acute or chronic renal failure undergoing liver transplantation (LP), liver retransplantation (LRT) or combined hepatorenal transplantation (CHRT). PATIENTS AND METHODS: We retrospectively reviewed the cases of 22 patients with advanced liver disease, 11 with acute renal failure and 11 with chronic renal failure. We performed 6 LT, 5 LRT and 11 CHRT. The following data were recorded in the periods before, during and immediately after surgery: metabolic, hemodynamic and coagulation parameters; bicarbonate, calcium and inotropic drug requirements; incidences during reperfusion of the graft; surgical technique used; and survival. RESULTS: Seven patients (32%) needed hemodialysis, 4 (18%) needed ultrafiltration, 7 (32%) needed both and 4 (18%) required neither. For 6 patients total clamping of the inferior vena cava (ICV) was required with external venovenous bypass. For 8 patients total clamping of the IVC was performed without venovenous bypass. For 8 others IVC clamping was partial with retrohepatic preservation (piggy-back). There were 2 deaths during surgery, 4 more within the first month after surgery and 4 more in the second month. Overall survival was 36.4% among acute patients and 72.7% among CHRT patients. CONCLUSIONS: 1) Conventional hemodialysis during surgery is feasible and gives good results; 2) conventional "high efficiency" hemodialysis is more effective and useful in these patients than is either slow, continuous hemodialysis or filtration; 3) the survival rate of CHRT patients is similar to that of patients undergoing LT with normal kidney function, and 4) partial IVC clamping in the anhepatic phase may decrease the need for ultrafiltration.
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Human monocyte-derived macrophages are transformed into foam cells upon incubation with immune complexes containing low-density lipoprotein (LDL-IC), which are internalized predominantly through Fc gamma receptor-mediated phagocytosis. We investigated whether the FcR gamma-mediated ingestion of LDL-IC is associated with functional and metabolic activation of the ingesting cells. As end points we used the assay of released interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) and the reduction of nitroblue tetrazolium, which measures the respiratory burst. LDL-IC, added to the macrophages in concentrations known to induce intracellular accumulation of cholesterol esters and foam cell transformation, stimulated both the cytokine release and the respiratory burst more efficiently than control immune complexes. Time course studies of cytokine release and mRNA expression suggest that the synthesis and release of these two cytokines is under independent control. TNF alpha was released almost immediately after addition of LDL-IC to the macrophages, coinciding with increased early expression of TNF alpha mRNA, detectable 30 min after stimulation. In contrast, IL-1 beta was only increased in stimulated cell supernatants after 8 hr, and the onset of expression of IL-1 beta mRNA was also delayed in comparison to that of TNF alpha mRNA. We noted wide variations in the amounts of TNF alpha released by monocyte-derived macrophages from different donors. We also found that those macrophages which released higher levels of TNF alpha also took up higher amounts of 125I-labeled LDL, suggesting that the expression of LDL receptors by LDL-IC-stimulated macrophages is somehow linked to the degree of activation of these cells. Experiments using the measurement of the oxidative burst as end point corroborated that LDL-IC cause a general activation of macrophage functions. In conclusion, human macrophages are efficiently activated by LDL-IC, as reflected by the release of IL-1 beta and TNF alpha and by the release of oxygen active radicals. Thus, the presentation of LDL-IC to human macrophages induces a variety of metabolic and functional changes which are likely to contribute, directly or indirectly, to endothelial damage and progression of the atheromatous lesion.
BASIS: The abdominal manifestations in the patient with HIV infection are increasingly frequent. We have conducted the present study in order to determine the diagnostic usefulness of the abdominal echography in the clinical assessment of the patient. MATERIALS AND METHODS: We review the echographic findings of 112 patients carrying the HIV with or without the Acquired Immunodeficiency Syndrome (AIDS). Seventy eight patients were men and 34, women, with an average age of 30 years. The main risk group was parenterally drug addiction (72%). The stage of the HIV infection was IVC1 in 41% of the cases, II in 23%, III in 13% and IVC2 in 13%. The echographic exploration was performed using a real-time echography, with a probe of 3.5 Mhz, assessing according to conventional criteria the abdominal organs and their pathology, masses and free intraabdominal fluid. The echographic characteristics were first broadly assessed in the patients from the series and later on, according to the patient's pathology. (Infectious, acute abdominal, hepatic biochemical disorders, HIV carrier-associated pathology). RESULTS: In 33% of the cases, the echography was normal. Hepatomegaly was the most frequent echographic sign: 56 patients (50%), followed by splenomegaly in 43 patients (38.3%), standing out the affection of the biliary and/or vesicular ductus in 7 patients (6.2%). The echographic findings were not related to the HIV infection stage, nor with the presence of hepatic biochemical disorders. However, the presence of organomegaly (hepatosplenomegaly associated or not to retroperitoneal adenopathies) were more frequent in the group with infectious complication, 33.3% vs 19.6% (p < 0.01), that in the patients without associated infectious processes. In patients with medical or surgical acute abdominal pathology, the echography was diagnostic in 9 out of 10 patients. CONCLUSION: In the HIV patient, the echography allows an specific initial diagnostic assessment, being able in most of the patients with abdominal manifestations to diagnose the causal pathology.
A comparison of the antigenic activity of soluble extracts of Entamoeba histolytica kept in axenic and polyxenic cultures is undertaken. Special care was kept so as to keep the protein native structure unharmed. Chromatographic separation at G-200 was performed, and three fractions were obtained and submitted to reactions with the sera of 10 patients with a proven diagnosis of amebic hepatic abscess, 5 patients with amebic dysentery from whom the protozoon was isolated and cultured from feces, and finally from 10 control subjects. The ELISA technique was employed to detect the levels of antibodies, using the raw, soluble, antigens and the chromatographic ones which were obtained. The specificity of the antibodies was analyzed with I.E.E., and a spectrophotometric reading of the raw, soluble, antigens adsorbed was performed by chromatographic affinity, with sepharose columns joined with purified immunoglobulins extracted from the seric combinations of each one of the studied individuals. Our results prove that the values of D.O. of the ELISA, when a soluble SAX I fraction is used, are statistically significant when compared with the raw, soluble, antigen, and this fraction allows discrimination between patients with intestinal and extraintestinal amebiasis. Specific reactivity was demonstrated by antigenic, proteic, bands opposed to the sera from patients with hepatic abscesses, with the use of axenic, soluble antigen, as well as at least one proteic band which reacts with the sera of patients with amebic dysentery. Proteic bands that react indistinctly with immunoglobulins from the three studied groups were demonstrated. The polyxenic, soluble extract demonstrated a proteic band recognized by the sera from patients with amebic dysentery.
Amebiasis continues to be of epidemiological importance in underdeveloped countries. Clinical diagnosis and epidemiological setting in a region are based on the fecal microscopic identification of cysts or trophozoites. This procedure requires well trained personnel, is laborious, of low sensitivity and frequently yields false-positives results. The present study was designed to develop an immunoenzymatic fecal 96 kDa antigen capture test (COPROELISA-Eh) more sensitive and specific than microscopic diagnosis of amebiasis. Triplicates of 177 stool samples processed by the formol-ether concentration method, were defined as positive or negative by three experienced microscopic observers. Another aliquot was submitted to the antigen capture test by a monoclonal antibody against a specific membrane antigen of pathogenic strains of Entamoeba histolytica. Optical densities were interpreted as positive when they exceeded the mean value of negative samples plus two standard deviations. COPROELISA-Eh showed a 94.4% sensitivity, 98.3% specificity, 96.2% positive predictive value and 97.6% negative predictive value for the detection of E. histolytica in feces. COPROELISA-Eh is more sensitive and specific than microscopic examination, does not require specially trained personnel and allows the simultaneous processing of a large number of samples.
In a multicenter study, 970 serum samples were collected from venezuelan health workers. Presence of HBV serological markers (HBsAg, antiHBs and total anticore) were screened by microELISA. Two-hundred and forty-seven samples (27%) showed at least one positive marker, being the most frequently found the antisurface antibody which was present in different working areas, including those considered at the low exposure level (medicine 24.7%). The proportion of antisurface positive samples also was significantly higher in the group with more than 10 years of service compared to the prevalence showed by the group with less than 5 years (19.1 vs 12.8%). Groups considered to be at low risk, contrary to the expected results, showed a similar or higher prevalence compared to the groups classified as continues or frequent exposure (17.7 vs 8.6%). Our findings suggest a permanent HBV load circulation at the venezuelan hospitals environment.