Genetic classification of Echinococcus granulosus cysts from humans, cattle and camels in Libya using mutation scanning-based analysis of mitochondrial loci

We genetically classified Echinococcus granulosus from humans, cattle and camels in Libya utilizing DNA regions (designated pcox1 and pnad1) within the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) mitochondrial genes, respectively. Polymerase chain reaction (PCR)-based single-strand conformation polymorphism (SSCP) analysis of pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n = 176) revealed four distinct electrophoretic profiles for each locus. Direct sequencing of selected amplicons representing each of these profiles defined four different sequence types for each locus, which were present in five different combinations (designated haplotypes A–E) amongst all 176 isolates. Phylogenetic analysis of concatenated sequence data for these five haplotypes, together with a range of well-defined reference sequences, inferred that all cyst isolates from humans (n = 55) and a small number from cattle (13% of 38) belonged to the G1–G3 complex of E. granulosus (or E. granulosus sensu stricto), whereas most (87%) cysts from cattle and all 83 of them from camels were linked to the G6–G10 complex (or Echinococcus canadensis). The present study provides a foundation for future large-scale studies of the epidemiology and ecology of E. granulosus in Libya and other African countries.     

Successful Percutaneous Ablation of Ventricular Tachycardia in Congenitally Corrected Transposition of the Great Arteries, a Case Report

Ventricular tachycardia (VT) is rarely recognized in patients with congenitally corrected transposition of the great arteries (CCTGA). We describe a 48-year-old woman with CCTGA, systemic atrioventricular valve replacement for Ebsteinoid malformation of the valve, ventricular dysfunction and ventricular tachycardia related to the previous surgical scar. The patient had successful non-contact mapping and radiofrequency ablation of the offending tachycardia substrate.     

Adjacent organ involvement in Salmonella aortic aneurysms

Salmonella aortic aneurysms occasionally affect adjoining organs. This study reports on 2 elderly men with fatal cases of Salmonella enteritidis involving adjacent organs: aortobronchial fistula from a thoracic aneurysm, and renal involvement from an infrarenal aneurysm. The hope of averting a tragic outcome lies in prompt clinical and radiological recognition followed by effective medical and early surgical interventions.     

Pathophysiology of hereditary hemochromatosis

Hereditary hemochromatosis (HH) encompasses several inherited disorders of iron homeostasis characterized by increased gastrointestinal iron absorption and tissue iron deposition. The most common form of this disorder is HFE-related HH, nearly always caused by homozygosity for the C282Y mutation. A substantial proportion of C282Y homozygotes do not develop clinically significant iron overload, suggesting roles for environmental factors and modifier genes in determining the phenotype. Recent studies have demonstrated that the pathogenesis of nearly all forms of HH involves inappropriately decreased expression of the iron-regulatory hormone hepcidin. Hepcidin serves to decrease the export of iron from reticuloendothelial cells and absorptive enterocytes. Thus, HH patients demonstrate increased iron release from these cell types, elevated circulating iron, and iron deposition in vulnerable tissues. The mechanism by which HFE influences hepcidin expression is an area of current investigation and may offer insights into the phenotypic variability observed in persons with mutations in HFE.     

Effectiveness of anemia and chronic kidney disease as predictors for presence and severity of coronary artery disease in patients undergoing stress myocardial perfusion study

Chronic kidney disease (CKD) and anemia portend a higher risk of cardiac events and mortality. We sought to ascertain whether coronary artery disease (CAD) by myocardial perfusion single-photon emission computed tomography is more common in patients with CKD (glomerular filtration rate < or =60 ml/min/1.73 kg/m(2)) and/or anemia (hemoglobin level < or =13 g/L) and the impact of different degrees of CKD. One thousand five hundred eighty patients (mean age 65 +/- 10 years) underwent gated myocardial perfusion single-photon emission computed tomography and clinical evaluation. Patients were divided into 4 groups (group 1, no anemia/no CKD, n = 800; group 2, anemia/no CKD, n = 195; group 3, CKD/no anemia, n = 332; group 4, anemia/CKD, n = 253). Multivariate logistic regression analysis was undertaken to examine the association of these diagnoses with abnormal myocardial perfusion single-photon emission computed tomogram. Compared with patients with neither diagnosis, an abnormal scan was more common in those with anemia or CKD. Patients with anemia and CKD exhibited more severe CAD (mean summed stress score 6.8 vs 4.7, p <0.01). Established high-risk findings were more prevalent in patients with anemia and/or CKD, including a summed stress score > or =8, transient ischemic dilation, or a left ventricular ejection fraction < or =40% (group 1 28%, group 2 38%, group 3 38%, group 4 48%, all p values <0.01). Patients with moderate CKD demonstrated an increased risk of an abnormal scan (odds ratio 2.66, p <0.0001). After adjustment in multivariate analysis, anemia and CKD each remained predictors for an abnormal scan. The association was stronger in those with the 2 conditions (odds ratio for high-risk scan 1.89, p = 0.0002). In conclusion, in patients with suspected CAD, anemia and CKD are predictors of myocardial perfusion single-photon emission computed tomographic markers for worsened outcomes. The relation was independent of other risk factors, supporting the inclusion of anemia and CKD in global risk assessment for patients with suspected CAD.     

Drug Use, Increasing Incarceration Rates, and Prison-Associated HIV Risks in Thailand

Background: Incarceration is a known risk for HIV infection in Thai drug users. Through the 1990s, incarceration rates for drug-related offenses rose sharply, whereas HIV prevention and drug treatment in prisons remained limited. Methods: We assessed HIV and incarceration risks for injection drug users (IDU) and non-IDU in a large treatment center cohort in northern Thailand to investigate HIV and prison risks in this period. We used Thai Bureau of Corrections data to assess incarceration and prevention funds in prisons, 1992–2000. Results: Among 1,865 drug user in the treatment cohort, 503 (27.0%) had ever been jailed. Men (OR 3.3, 95% CI 2.1, 5.2), IDU (OR 6.3, 95% CI 5.1, 7.9), and men who have sex with men (MSM) (OR 3.4, 95% CI 1.8, 6.3) were more likely to have been jailed. Among male IDU who had ever been jailed (N = 272), 15.8% had used drugs in prison. In a multivariate model, incarceration and ever IDU remained independently associated with HIV infection; IDU, MSM behaviors, and harmful traditional practices remained independently associated with having been jailed. From 1992 to 2000, overall alleged narcotics offenses increased from 117,000 to 276,000/year. The number of persons incarcerated for narcotics offenses increased fivefold from 1992 to 1999, from 12,860 to 67,440. For FY 2000, narcotics treatment accounted for 0.06% of the Thai corrections budget, whereas HIV programs in prisons were 0.017%. Conclusions: Incarceration rates for narcotics offenses have increased sharply in Thailand, whereas prevention has lagged. Having been jailed is an important independent risk for HIV infection among Thai male drug users, especially IDU and MSM. HIV prevention and drug treatment are urgently needed in Thai prisons.     

The effects of dobutamine on cardiac sympathetic activity in patients with congestive heart failure

OBJECTIVES: The goal of this work was to study the effects of short-term infusion of dobutamine on efferent cardiac sympathetic activity. BACKGROUND: Increased efferent cardiac sympathetic activity is associated with poor outcomes in the setting of congestive heart failure (CHF). Dobutamine is commonly used in the therapy of decompensated CHF. Dobutamine, through its effects on excitatory beta-receptors, may increase cardiac sympathetic activity. METHODS: Seven patients with normal left ventricular (LV) function and 13 patients with CHF were studied. A radiotracer technique was used to measure cardiac norepinephrine spillover (CANESP) before and during an intravenous infusion of dobutamine titrated to increase the rate of rise in LV peak positive pressure (+dP/dt) by 40%. RESULTS: Systemic arterial pulse pressure increased significantly in response to dobutamine in the normal LV function group (74 +/- 3 mm Hg to 85 +/- 3 mm Hg, p = 0.005) but remained unchanged in the CHF group. Dobutamine caused a significant decrease in LV end-diastolic pressure in the CHF group (14 +/- 2 mm Hg to 11 +/- 2 mm Hg, p = 0.02), an effect not observed in the normal LV group. In the normal LV function group, CANESP did not change in response to dobutamine (75 +/- 22 pmol/min vs. 72 +/- 22 pmol/min, p = NS). In contrast, dobutamine infusion was associated with a significant reduction in CANESP in patients with CHF (199 +/- 43 pmol/min to 128 +/- 30 pmol/min, p < 0.0009). CONCLUSIONS: Dobutamine infusion caused a significant sympatholytic response in patients with CHF. This sympathetic withdrawal response is probably related to reduction of LV filling pressures and/or activation of ventricular mechanoreceptors with dobutamine infusion.