ABSTRACT
Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.
O parvovírus B19 infecta predominantemente células eritróides, causando inibição transitória da eritropoiese. Pacientes imunocomprometidos podem ser incapazes de produzir anticorpos neutralizantes, evoluindo com grave anemia crônica. Estudos epidemiológicos da população de Niterói mostraram que a infecção ocorre periodicamente no final da primavera e no verão. Descrevem-se 55 pacientes infectados pelo HIV atendidos num ambulatório de doenças infecciosas nesta cidade num período de cinco meses, no qual a circulação do parvovírus B19 foi documentada. Todos os pacientes estavam sob terapia anti-retroviral. Não se encontrou IgM anti-B19, mas notou-se uma prevalência alta de IgG anti-B19 (91%). Em seis pacientes verificou-se a presença de DNA do B19 por hibridização em dot-blot, o que não se confirmou por PCR. Nenhum destes seis pacientes tinha anemia, e apenas um tinha células CD4 abaixo de 200 x 107/L. Conclui-se que infecção persistente causando anemia é um achado infreqüente em nossos pacientes HIV positivos sob terapia medicamentosa.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Parvoviridae Infections/etiology , HIV Seropositivity/complicationsABSTRACT
El objetivo fue estudiar estadísticamente el valor de la biopsia rápida para diagnosticar malignidad, global y específicamente en los diversos órganos y sistemas. Se consideró como presente la malignidad cuando la biopsia diferida así lo concluyó. Se realizó un estudio retropectivo de 659 biopsia rápida y sus correspondientes biopsias diferidas, efectuadas enel Servicio de Anatomía Patológica del Hosp. Dr. G. Fricke entre Septiembre de 1995 y Febrero de 1999.Seaplicó un test de screening para el análisis de los resultados al universo de muestras y por órganos y sistemas, excluyendo las biopsias rápidas no concluyentes
Subject(s)
Humans , Biopsy , Neoplasms/pathology , Sensitivity and Specificity , Paraffin Embedding , Biopsy/statistics & numerical data , Carbon Dioxide , False Positive Reactions , Microtomy/statistics & numerical data , Predictive Value of Tests , ToluidinesABSTRACT
In this work, it was studied the effect that amphotericin B bound to liposomes (L-AmB) exerted on the potassium permeability of human erythrocytes and also on the rate of growth on culture of promastigotes of Leishmania sp. Liposomal amphotericin B was prepared by adding AmB to sonicated liposomes composed of egg-phosphatidylcholine (PC) or dipalmitoyl-phosphatidylcholine (DPPC). Incubation of human erythrocytes with free AmB (dissolved in organic solvent) led to a rapid enhancement of potassium efflux from erythrocytes. This permeabilizing effect of amphotericin B in erythrocytes decreased when the polyene antibiotic was added dissolved in a salt solution but it was negligible when AmB was added bound to liposomes (L-AmB). Liposomal AmB preparations made of PC or DPPC were equally effective in reducing AmB -induced potassium efflux from red cells to a minimum. By contrast, it was found that exposure of Leishmania promastigotes to liposomal AmB (PC or DPPC L-AmB) led to an inhibition of cell growth rate in a magnitude comparable to that exerted by AmB added in salt solution. Short term measurements of the magnitude of cell lysis after treating Leishmania promastigotes with amphotericin B revealed that the lytic effect of AmB added in aqueous solution, organic solvent or as PC-Liposomal AmB can be detected much earlier than that exerted by DPPC-Liposomal AmB. These results are discussed in terms of the differential capacity of AmB binding to liposomes of different composition and also on the characteristics of the mechanism of incorporation of AmB molecules to the membrane of target cells