Point-of-care ultrasound for diagnosing extrapulmonary TB.

Despite the high morbidity and mortality globally, standard microbiologic diagnosis for TB requires laboratory infrastructure inaccessible in many resource-limited areas and may be insufficient for identifying extrapulmonary disease. Point-of-care (POC) ultrasound facilitates visualization of extrapulmonary manifestations, permitting laboratory-independent diagnosis, but its diagnostic utility remains unclear.We conducted a systematic review of five online databases for studies reporting ultrasound findings among cases with and without extrapulmonary TB (EPTB). A minimum of two authors independently screened and reviewed each article, and extracted data elements of interest. We conducted a series of univariate meta-analyses using a random-effects model to calculate the pooled effect estimate and 95% confidence interval (CI) for each outcome: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).Of 279 articles identified, 6 were included. There were 699 cases of EPTB among 1,633 participants. The pooled sensitivity estimate was 0.72 (95% CI 0.57-0.88). The pooled specificity estimate was 0.77 (95% CI 0.63-0.90). The pooled PPV and NPV estimates were respectively 0.67 (95% CI 0.47-0.87) and 0.85 (95% CI 0.77-0.93).POC ultrasound showed modest test characteristics for diagnosing EPTB, which may constitute an improvement over some currently available diagnostics..

Hepatitis delta virus genotypes I and III circulate associated with hepatitis B virus genotype F In Venezuela.

The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among Venezuelan Amerindian populations, where these viruses are endemic, were determined by sequencing of PCR amplified products from HBsAg positive sera. HDV genotype I (n = 7, 6 from West Amerindians), and III (n = 5, 4 from South Amerindians), were found. Only one HDV genotype I isolate was associated with HBV genotype D, 4 HDV genotype I and 2 HDV genotype III infected individuals were co-infected with HBV genotype F. The failure to detect the South American HDV genotype III in West Amerindians might be related to the outbreak of fulminant hepatitis with high mortality rate occurred between 1979 and 1982, probably affecting more the Amerindians infected with HDV genotype III. These results suggest the circulation of HDV genotype I among Amerindians, probably introduced through European immigrations, and that this HDV genotype is able to replicate in association with HBV genotype F.

Hemodynamic effects of inhaled nitric oxide in women with mitral stenosis and pulmonary hypertension.

Mitral stenosis (MS) is associated with elevated left atrial pressure, increased pulmonary vascular resistance (PVR), and pulmonary hypertension (PH). The hemodynamic effects of inhaled nitric oxide (NO) in adults with MS are unknown. We sought to determine the acute hemodynamic effects of inhaled NO in adults with MS and PH. Eighteen consecutive women (mean age 58 +/- 15 years) with MS and PH underwent heart catheterization. Hemodynamic measurements were recorded at baseline, after NO inhalation at 80 ppm, and after percutaneous balloon valvuloplasty (n = 10). NO reduced pulmonary artery systolic pressure (62 +/- 14 mm Hg [baseline] vs 54 +/- 15 mm Hg [NO]; p <0.001) and PVR (3.7 +/- 2.5 Wood U [baseline] vs 2.2 +/- 1.4 Wood U [NO]; p <0.001). NO had no effect on mean aortic pressure, left ventricular end-diastolic pressure, left atrial pressure, cardiac output, or systemic vascular resistance. Mitral valve area increased after valvuloplasty (0.9 +/- 0.2 cm2 [baseline] vs 1.6 +/- 0.3 cm2 [postvalvuloplasty]; p <0.001). A decrease in left atrial pressure (25 +/- 4 mm Hg [baseline] vs 17 +/- 4 mm Hg [after valvuloplasty]; p <0.001) and pulmonary artery systolic pressure (58 +/- 12 mm Hg [baseline] vs 45 +/- 8 mm Hg [after valvuloplasty]; p <0.001) was observed after valvuloplasty. No change in cardiac output or PVR was observed. Thus inhaled NO, but not balloon valvuloplasty, acutely reduced PVR in women with MS and PH. This suggests that a reversible, endothelium-dependent regulatory abnormality of vascular tone is an important mechanism of elevated PVR in MS.

Hemodynamic effects and long-term outcome of percutaneous balloon valvuloplasty in patients with mitral stenosis and atrial fibrillation.

BACKGROUND: The presence of atrial fibrillation (AF) has been identified as a predictor of a suboptimal result in some patients undergoing percutaneous balloon valvuloplasty in the treatment of symptomatic rheumatic mitral stenosis. HYPOTHESIS: Atrial fibrillation adversely affects the short- and long-term outcome of patients with mitral stenosis undergoing percutaneous balloon valvuloplasty. METHODS: A retrospective chart review of 104 consecutive patients with rheumatic mitral stenosis undergoing percutaneous balloon valvuloplasty was performed. A successful procedure was defined as a final mitral valve area > or = 1.5 cm2 and the absence of a complication. Endpoints included freedom from mitral valve replacement, death, and repeat balloon valvuloplasty at 5 years. RESULTS: A successful procedure was obtained in 89% of patients with sinus rhythm and in 78% of patients with AF (p = NS). Patients in sinus rhythm had a greater cardiac output resulting in a larger final valve area than patients in AF (1.8 vs. 1.6 cm2, p < 0.05). Freedom from valve replacement, death, and repeat balloon valvuloplasty at 5 years was 75% for patients in AF and 76% for patients in sinus rhythm (p = NS). Lower postprocedure mitral regurgitation grade and absence of prior commissurotomy were the only independent predictors of event-free survival. CONCLUSIONS: Patients with mitral stenosis and AF have lower cardiac outputs and gradients than patients with sinus rhythm, despite similar valve areas. The long-term outcome of balloon valvuloplasty is independent of the initial cardiac rhythm.

[Effect of climatic factors on the epidemiology of rotavirus infection in children under 5 years of age in the city of Maracaibo, Venezuela]. / Influencia de los factores climatológicos en la epidemiología de la infección por rotavirus en los niños menores de 5 años de la ciudad de Maracaibo, Venezuela.

Diarrhea is one of the most common problem of public health worldwide, specially in developing countries. In Venezuela, this affection must be weekly reported when it occurs in children under five years of age. During June 1993 to May 1995, 379 stool specimens were obtained from children under five years of age with diarrhea admitted in Hospital de Niños of Maracaibo, Venezuela. Control group was conformed by 93 asymptomatic children. The rotavirus RNA was extracted with phenol-chloroform and precipitated with ethanol. Finally, polyacrylamide-gel-electrophoresis (PAGE), followed by silver staining was employed for rotavirus detection. Our results showed 62 (16.4%) positive cases for rotavirus in symptomatic children and 9 (9.7%) in control group. The highest incidence was showed in the infants under one year of age (21.5%). The electrophoretic analysis revealed only one long electropherotype pattern in studied samples. It was observed a close relationship between the increase of rotavirus cases and the increase of the pluviometric index and a decrease of mean temperature observed during the period of study. Both variables determine the increase or decrease of viral infection in our region. This result shows the importance of the climatic factors in the rotavirus epidemiology.

Antigenic diversity of hepatitis B virus strains of genotype F in Amerindians and other population groups from Venezuela.

The adw4 subtype of hepatitis B virus (HBV) belongs to a unique genomic group (genotype F) representing the original HBV strains from the New World. Data regarding the prevalence of this subtype among HBV carriers in South America are, however, scarce, and those concerning HBV genotype F are based on only a few samples from Latin America. In this study, serum samples were obtained from 141 hepatitis B surface antigen (HBsAg) carriers from Amerindians and urban populations from Venezuela. The HBsAg subtype was identified with monoclonal antibodies in 105 samples, and the HBV genotype was identified by reverse-phase hybridization with DNA fragments in 58 samples. The adw4 subtype was highly prevalent in the population studied (75%); among the Amerindians, the prevalence was 97%. The adw2 subtype was also present (10%), while other subtypes (ayw3 and ayw4) were only occasionally found. The HBV subtype was associated with the expected genotype in most cases (80%), and thus genotype F was highly prevalent. Sequencing of viral strains that gave genotypes unpredicted by the HBsAg subtyping confirmed seven of them as belonging to not previously described genotype-subtype associations: namely, adw2 and ayw4 within genotype F.

Hepatitis G virus infection in Amerindians and other Venezuelan high-risk groups.

Recently, a new virus related to flaviviruses, the hepatitis G virus (HGV), or GBV-C virus, was discovered as a putative blood-borne human pathogen. HGV RNA (NS5 region) was amplified by reverse transcription-nested PCR in the sera of 6 of 64 (9%) hemodialysis patients; 2 of 80 (2.5%) West Yukpa Amerindians, a population with a high rate of HBV infection but negative for HCV infection; and 1 patient with an acute episode of non-A, non-B, non-C hepatitis (NABCH). The patterns of single-strand conformation polymorphism of the amplified products were unique among different specimens and similar on follow-up for hemodialysis patients. All patients tested remained HGV RNA positive 1 and 2 years later, without major sequence variation, except for the NABCH patient, for whom a double infection and an apparent clearance of the original dominant variant was observed after 2 years. The sequences of the NS5 amplified products demonstrated 85 to 90% identity with other reported HGV sequences.

Results of aortic valve replacement for aortic stenosis with relatively low transvalvular pressure gradients.

Fifty-two patients with low gradient critical aortic stenosis who underwent aortic valve replacement were found to have a perioperative mortality of 11% and an 8-year actuarial survival of only 29%. No hemodynamic variables, including valvular resistance, predicted long-term outcome, and the only clinical variable that predicted long-term survival was the absence of coronary artery disease.

Determination of genotypes of hepatitis C virus in Venezuela by restriction fragment length polymorphism.

Hepatitis C virus genotypes in Venezuela were analyzed by restriction fragment length polymorphism in the 5' noncoding region. The absence of BstUI digestion was found to be a useful marker for genotype 2 specimens. From 122 serum samples, 66, 20, and 2.5% were classified as genotypes 1, 2, and 3, respectively; 0.8% were classified as genotype 4; and 10% appeared to be mixed infections.

Reduced antibody reactivity to hepatitis C virus antigens in hemodialysis patients coinfected with hepatitis B virus.

Antibody reactivities to hepatitis C virus (HCV) antigens and to synthetic peptides derived from different parts of the HCV genome (core, NS4, and NS5) were evaluated in HCV-infected hemodialysis patients. In the RIBA 3 assay, NS5 was significantly less recognizable by sera of hemodialysis patients compared to other HCV-infected subjects. Among hemodialysis patients, those coinfected with hepatitis B virus (HBV) (positive for hepatitis B surface antigen [HBsAg+]) showed a reduction in reactivity to C33 and C100. Sera of only 23% of the hemodialysis patients (37 of 161) reacted with more than three of eight peptides tested, significantly fewer than the 60% (12 of 20) of the sera of other HCV-infected patients tested (P = 0.001). This immunosuppression was also manifested by a reduced frequency of recognition of additional peptides on follow-up. An even more reduced reactivity was observed among the HBV-coinfected patients (HBsAg+). The low-responder hemodialysis patients were not infected with any particular genotype of HCV, and the same HCV genotypes observed in the whole group of hemodialysis patients (1a, 1b, 2a, and 3a) were found circulating in the low-responder group. Even in this low-responder population, the good performance of two peptides (peptide 716, corresponding to a portion of the core, and peptide 59, corresponding to a portion of NS4) corroborates the immunodominance of the conserved epitopes within these peptides.

Hemodynamic assessment of patients with low-flow, low-gradient valvular aortic stenosis.

In aortic stenosis (AS), conventional indexes of severity vary with changes in transvalvular flow. It is important to determine the true severity of obstruction because AS in the presence of low cardiac output and low gradient is associated with high mortality during aortic valve replacement. This study compares 3 indexes of stenosis severity at different transvalvular flow rates in patients with low-flow, low-gradient critical AS. Eight patients with critical AS (valve area < or = 0.7 cm2), low cardiac output (< 4.0 L/min), and low mean transvalvular gradient (< or = 40 mm Hg) underwent hemodynamic assessment at baseline, after transvalvular flow was augmented with dobutamine, and after the valve opening was increased with percutaneous balloon aortic valvuloplasty. Severity of obstruction was assessed using 3 different measures: Gorlin formula calculated valve area, valvular resistance, and percentage left ventricular stroke work loss. Dobutamine infusion increased cardiac output by 35% and mean transvalvular gradient by 27%. The mean Gorlin formula calculated aortic valve area increased from 0.5 to 0.6 cm2 (p = 0.002). Percentage left ventricular stroke work loss increased from 23% to 28% (p = 0.03). Valve resistance was unchanged by dobutamine (350 to 310 dynes X sec X cm(-5); p = NS). Balloon valvuloplasty increased cardiac output 13% and decreased the gradient 31%; this resulted in an increase in the calculated valve area from 0.6 to 0.9 cm2 (p = 0.001). Percentage left ventricular stroke work loss decreased from 28% to 20% (p = 0.002), and valve resistance decreased from 310 to 181 dynes X sec X cm(-5) (p = 0.001) after valvuloplasty. We conclude that in patients with low-flow, low-gradient critical AS, valve resistance is the most flow-independent measure of severity of stenosis. All measures improve with percutaneous balloon aortic valvuloplasty.

The new milky way.

Our understanding of the large-scale structure of the Milky Way has undergone considerable revision during the past few years. The Galaxy is larger and much more massive than was previously supposed; the newly discovered mass consists of nonluminous matter which is likely to be the dominant form of matter in the universe. New analyses of the atomic hydrogen gas show that the disk of the Galaxy is about twice as extended as was previously thought. Beyond the sun, the gas is concentrated in large-scale, coherent spiral arms indicative of a regular four-armed spiral pattern. The outer edge of the disk has a remarkable scalloping.