Study of 30 cases of histoplasmosis observed in the Mato Grosso do Sul State, Brazil

Thirty cases of histoplasmosis observed at the University Hospital of the Federal University of Mato Grosso do Sul (HU-UFMS) from January 1998 to December 2005 are reported. Most (83.3%) of the patients were men, average 33.4 years old, 63.3% of them were born and living in Mato Grosso do Sul and 83.3% presented AIDS as an underlying disease. In almost all cases (96.7%) the disease occurred in its disseminated form and the most frequent clinical manifestations were: fever (83.3%), weight loss (70.0%), cough (63.3%), hepatomegaly and splenomegaly (40.0%), and lymph node enlargement (36.7%). The laboratory diagnosis was obtained in 29 patients by isolation of Histoplasma capsulatum from various clinical specimens cultivated in Sabouraud dextrose and brain heart infusion agar and in 16 patients the fungus was observed by direct microscopy of Giemsa-stained smears. The observed mortality was 40%. This is the first report in the literature of the occurrence of histoplasmosis in Mato Grosso do Sul State.     

Isolation and characterization of a novel toxin from the venom of the spider Grammostola rosea that blocks sodium channels.

This communication reports the chemical and physiological characterization of a novel peptide (GrTx1) isolated from the venom of the "rosean-tarantula"Grammostola rosea. This component was one among more than 15 distinct components separated from the soluble venom by high-performance liquid chromatography (HPLC). GrTx1 has 29 amino-acid residues, compactly folded by three disulfide bridges with a molecular weight of 3697Da. Here we show that this peptide blocks Na(+) currents of neuroblastoma F-11 cells with an IC(50) of 2.8+/-0.1muM, up to a maximum of about 85% at 10muM. Moreover, the right-shift (+20.1+/-0.4mV) of the fractional voltage-dependent conductance could be also compatible with a putative "gating-modifier" mechanism. No effects were seen on common K(+) channels, such as K(v)1.1 and 1.4, using concentrations of toxin up to 10muM. Sequence analysis reveals that GrTx1 is closely related to other spider toxins reported to affect various distinct ion channel functions. A critical analysis of this study suggests the necessity to search for other potential receptor sites in order to establish the preferred specificity of these kind of peptides.     

Protothecosis complicating prolonged endotracheal intubation: case report and literature review.

Prototheca species are ubiquitous, aerobic, unicellular algae closely related to the green algae Chlorella. Their involvement in human disease--in both immunocompetent and immunocompromised patients--has been reported with increasing frequency. The wide array of presentations has included cutaneous, subcutaneous, mucosal, bursal, catheter-related, and (in rare instances) systemic disease. We report a case of protothecosis complicating prolonged endotracheal intubation presenting as a nasopharyngeal ulceration with a soft-tissue mass, and we review the presentation, treatment, and outcome of the 59 previously reported cases of protothecosis. Optimal therapy for protothecosis includes excision (where possible) followed by systemic administration of amphotericin B; the sole exception is in the case of olecranon bursitis, where excision alone appears curative. The role of the newer imidazoles is yet to be determined.     

Cytokine generation in whole blood, leukocyte-depleted and temporarily warmed red blood cell concentrates

BACKGROUND AND OBJECTIVES: It has been suggested that inflammatory cytokines such as Interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha) and IL-8 might be responsible for a large number of non-antibody-mediated adverse reactions to the transfusion of blood components, especially of platelet concentrates (PCs). The aim of this study was to compare the levels of proinflammatory cytokines in different blood components containing red cells such as buffy-coat-free packed red cells (RBCs), filtered RBCs and whole blood (WB) during storage under several conditions. MATERIALS AND METHODS: WB (CPD-A1, n = 16) was stored for 35 days at 2-6 degrees C; samples were taken on days 0, 21 and 35. Buffy-coat-poor RBCs in additive solution PAGGS-M (n = 16) were divided into halves, one half was leukocyte (WBC)-depleted by filtration on day 0, both halves were stored for 49 days at 2-6 degrees C (samples: days 0, 21, 49). Furthermore, buffy-coat-poor, unfiltered SAG-M RBCs (n = 16) were halved immediately after production and stored at 2-6 degrees C until day 42 (samples: days 0, 21, 42). One half remained at room temperature for 24 h on day 3. Cytokine levels were determined with commercial enzyme-linked immunosorbent assays. RESULTS: Levels of IL-1beta and TNF-alpha rose during storage of WB and RBCs. IL-6 could be detected markedly above the detection threshold in WB only. At the end of storage, we detected IL-8 in 1 of 16 units of WB tested, in 10 of 16 standard PAGGS-M RBCs and in 15 of 16 temporarily warmed SAG-M RBCs. Prestorage filtration of RBCs prevented the accumulation of IL-1beta and TNF-alpha. Temporarily warming of RBCs for 24 h did not cause any substantial increase in cytokine levels other than IL-8. RBCs stored in different additive solutions (PAGGS-M versus SAG-M) showed similar cytokine concentrations during storage. The cytokine content of WB was very similar to that of buffy-coat-poor RBCs. CONCLUSION: Cytokine levels measured in WB and buffy-coat-poor RBCs result in levels which are unlikely to cause febrile reactions even in the case of massive transfusion. We conclude that, according to present knowledge, there is no reason for prestorage filtration of buffy-coat-poor RBCs or WB to avoid febrile transfusion reactions due to cytokine accumulation during storage.     

Toxoplasma encephalitis in patients with acquired immune deficiency syndrome: diagnosis and response to therapy

Although Toxoplasma gondii is the most commonly recognized cause of central nervous system mass lesions in patients with acquired immune deficiency syndrome, published investigations have provided little information about criteria for diagnosis of toxoplasmosis or the response to therapy. In this series the method of diagnosis and response to therapy were assessed in 14 patients who had evidence for toxoplasmosis based on routine histopathology, immunoperoxidase staining, or mouse inoculation. These patients presented with clinical and radiologic findings that did not clearly distinguish them from patients with other infectious or neoplastic processes. Excisional biopsies usually showed tachyzoites on routine histology, but needle biopsies were usually negative unless mouse inoculation or immunoperoxidase staining was employed. Response to pyrimethamine and sulfadiazine therapy was often prompt, but therapy had to be continued for long periods of time to maintain a clinical response, and no alternative regimen of one or more drugs appeared to be effective in patients unable to tolerate both pyrimethamine and sulfadiazine.     

Mechanical load on the inspiratory muscles during exercise hyperpnea in patients with Type 1 (insulin-dependent) diabetes mellitus

Summary The aim of this study was to evaluate the difference between Type 1 (insulin-dependent) diabetic patients and healthy control subjects regarding inspiratory muscle load during exercise hyperpnea. For this purpose an incremental progressive exercise test on a cycle ergometer was performed by 36 Type 1 diabetic patients and 40 healthy subjects. In order to determine the mechanical load on the inspiratory muscles breath by breath, we selected the following two parameters, which represent the pressure generated by the inspiratory muscles as well as the duration and velocity of their contraction: (1) the oesophageal tension time index, which is the product of the duty cycle (ratio of inspiratory time to total breath cycle duration) and the mean oesophageal pressure expressed as a percentage of the maximal oesophageal pressure and (2) the mean oesophageal pressure change per time unit during the inspiratory phase of each breathing manoeuver, which is expressed as a fraction of the subject's maximal oesophageal pressure. Comparison of the two groups revealed that at similar levels of ventilation the mechanical load on the inspiratory muscles was significantly higher in the Type 1 diabetic patients than in the control subjects. When the loading was stopped the maximal ventilation was lower in the patients. Nevertheless, they reported a degree of respiratory effort sensation comparable to the control group, which seems to have been caused by an increase of the mechanical load on the ventilatory muscles.     

Flow diversion treatment: intra-aneurismal blood flow velocity and WSS reduction are parameters to predict aneurysm thrombosis

Background

To evaluate the haemodynamic changes induced by flow diversion treatment in cerebral aneurysms, resulting in thrombosis or persisting aneurysm patency over time.

Method

Eight patients with aneurysms at the para-ophthalmic segment of the internal carotid artery were treated by flow diversion only. The clinical follow-up ranged between 6?days and 12?months. Computational fluid dynamics (CFD) analysis of pre- and post-treatment conditions was performed in all cases. True geometric models of the flow diverter were created and placed over the neck of the aneurysms by using a virtual stent-deployment technique, and the device was simulated as a true physical barrier. Pre- and post-treatment haemodynamics were compared, including mean and maximal velocities, wall-shear stress (WSS) and intra-aneurysmal flow patterns. The CFD study results were then correlated to angiographic follow-up studies.

Results

Mean intra-aneurysmal flow velocities and WSS were significantly reduced in all aneurysms. Changes in flow patterns were recorded in only one case. Seven of eight aneurysms showed complete occlusion during the follow-up. One aneurysm remaining patent after 1?year showed no change in flow patterns. One aneurysm rupturing 5?days after treatment showed also no change in flow pattern, and no change in the maximal inflow velocity.

Conclusions

Relative flow velocity and WSS reduction in and of itself may result in aneurysm thrombosis in the majority of cases. Flow reductions under aneurysm–specific thresholds may, however, be the reason why some aneurysms remain completely or partially patent after flow diversion.     

EPI Imaging of Global Increase of Brain MR Signal with Breath-hold Preceded by Breathing O2

Brain MR signal has been observed to decrease during cessation of breathing due to the increase of deoxyhemoglobin in the blood. However, for both animal and human studies, we have demonstrated that if the subjects breathed 100% oxygen in advance of apnea for a short time, T₂*-weighted MR brain signal increased when breathing was stopped for a period of 30–60 s. This demonstrates the possibility of measuring responses to hemodynamic change throughout the entire brain with a single respiratory perturbation in a rapid, reliable, and robust manner.