The microsporidian Encephalitozoon hellem is being reported with increasing frequency in HIV-positive subjects, as an agent of disseminated microsporidiosis without involving the gastrointestinal tract. We describe a case of pulmonary microsporidiosis in a 27-year-old Italian man with AIDS who developed fever, cough, and dyspnea. A chest X-ray showed multiple bilateral pulmonary opacities and mediastinal lymph-node enlargement. Stained smears of bronchoalveolar lavage sediment showed oval structures consistent with microsporidian spores. Viral, bacterial and fungal cultures were repeatedly negative, whereas microsporidia were successfully cultured in human and bovine fibroblast cell lines. Analysis of electron micrographs indicated that the isolate belonged to the genus Encephalitozoon. Based on further immunological, biochemical and molecular studies it was characterized as E. hellem. Even though a temporary improvement with albendazole therapy was noticed, the patient deteriorated clinically and died of severe respiratory distress.

AIDS-Related Opportunistic Infections↗

PubMed1996

Interleukin (IL)-6 gene expression in the central nervous system is necessary for fever response to lipopolysaccharide or IL-1 beta: a study on IL-6-deficient mice.

Interleukin (IL)-6, IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) are considered to act as endogenous pyrogens. Because of the complex pattern of cross-inductions between these cytokines, the relative role of the central and peripheral production of these cytokines in eliciting the fever response has not yet been clarified. The purpose of this study was to determine the role of IL-6 in the fever response by making use of mice carrying a null mutation in the IL-6 gene. The intraperitoneal injections of lipopolysaccharide (LPS) (50 micrograms/kg) and recombinant murine (rm) IL-1 beta (10 micrograms/kg), respectively, failed to evoke fever response in IL-6-deficient mice, whereas the same doses of LPS and rmIL-1 beta caused fever response in wild-type mice. The fever response could be induced in the IL-6-deficient mice by intracerebroventricular injection of recombinant human (rh) IL-6 (500 ng/mouse), whereas intracerebroventricular injection of rmIL-1 beta (100 ng/mouse) failed to produce fever response in the IL-6-deficient mice. These results suggest that central IL-6 is a necessary component of the fever response to both endogenous (IL-1 beta) and exogenous (LPS) pyrogens in mice and that IL-6 acts downstream from both peripheral and central IL-1 beta.

Animals↗

PubMed1996

Subchronic glucocorticoid pretreatment reversibly attenuates IL-beta induced fever in rats; IL-6 mRNA is elevated while IL-1 alpha and IL-1 beta mRNAs are suppressed, in the CNS.

Subchronic (36 h) exposure of rats to corticosterone (CS) (100 mg/pellet,subcutaneously), blocked the pyrogenic response to recombinant human interleukin 113 (rhIL-1 beta, 5 mu g/kg, ip.). CS treatment reduced the basal mRNA levels of IL-1 alpha and IL-1 beta, but elevated the mRNA levels of IL-6 in the hypothalamus and hippocampus as shown by RT-PCR. The CS treatment clamped the cytokine mRNA levels, and injection of rhIL-1 beta to CS treated rats did not significantly affect these altered mRNA levels. IL-6 bioactivity in serum was not significantly changed by CS treatment, but increased 50 times upon injection of rhIL-1 beta. rhIL-1 beta caused a significantly lower induction of serum IL-6 levels in CS pretreated rats (9-fold). The pyrogenic response to injection of rhIL-1 beta has returned 5 days after the removal of the corticosterone pellet, and the hypothalamic cytokine mRNA levels (IL-1 alpha, IL-1 beta and IL-6) have returned to basal. These results suggest that altered and clamped hypothalamic IL-1 alpha, IL-1 beta and IL-6 mRNA levels may be involved in the antipyretic effects of a pretreatment with high doses of CS and that these CS effects are rapidly reversible.

Analysis of Variance↗

PubMed1996

Direct sequencing of the PCR amplified SSU rRNA gene of Entamoeba dispar and the design of primers for rapid differentiation from Entamoeba histolytica.

Since 1993, strains of Entamoeba histolytica sensu lato have been assigned to 2 species on the basis of clinical, biochemical, immunological and genetic evidence: the pathogenic strains to E. histolytica sensu stricto, the non-pathogenic strains to Entamoeba dispar. Analysis of the gene encoding for the small subunit ribosomal RNA (SSU rDNA) supports the existence of 2 species. However, while 3 whole SSU rDNA sequences are available in the data bases for E. histolytica, only a partial sequence has been published for E. dispar. Here we report a SSU rDNA sequence for E. dispar. Compared to those of E. histolytica, this sequence shows 1.7% nucleotide substitutions. On the basis of our rDNA data, 2 primers were designed to produce polymerase chain reaction (PCR) amplification from both E. histolytica and E. dispar. Primer specificity for the 2 amoebae was assessed both theoretically against the data bases, and experimentally against a collection of eukaryotic and prokaryotic DNAs. The amplified stretch encompasses a polymorphic Dde I restriction site which allows, after cleavage of the fragment, E. histolytica and E. dispar to be distinguished. The reliability of this method of identification was assessed comparing the results with those based on classic isoenzyme analysis.

Animals↗

PubMed1996

Madin Darby canine kidney: a new cell line for Pneumocystis carinii in vitro culture.

Pneumocystis carinii pneumonia (PCP) is a highly frequent cause of morbidity and mortality in immunocompromised subjects, particularly in HIV-infected ones. The biology of P. Carinii is poorly understood because of the lack of reliable synthetic media or adequate cell lines to grow this opportunistic pathogen in continuous culture. We reported the suitability of the MDCK (Madin Darby Canine Kidney, ATTC CCL 34) cell line to support the temporary microorganism's growth in vitro and the experimental pharmacological trials, in comparison with the HEL 299 cell line, used as reference standard.

Animals↗

PubMed1996