HIV and tuberculosis coinfection in the southern region of Ethiopia: a prospective epidemiological study

HIV has played a key role in TB, modifying its incidence and clinical presentation. This study describes the prevalence of HIV among TB patients attending health facilities in the southern region of Ethiopia. The HIV prevalence was 18% for female and 21% for male TB patients. 15% and 30%, respectively, of the rural and urban patients with TB were HIV positive (p<0.05). 19% (51/261) smear-positive PTB, 26% (36/137) smear-negative PTB and 11% (10/94) of the extrapulmonary TB patients were HIV positive. The proportion of patients with extra-PTB varied from 11% to 38% across the centres and was highest in the zones with the lowest HIV prevalence. In the light of limited diagnostic facilities, clinicians often make a clinical diagnosis of TB without laboratory confirmation. The increase in the number of TB cases could be due to HIV. However, the number of health facilities offering TB treatment in the area also increased (from 53 to 236) during the same period and the increase in TB is likely to be the result of a combination of factors, including improved detection and HIV. It is important to consider this multi-factorial phenomenon when interpreting the increase of TB in a geographical area.     

Effects of Melatonin on Ischemia and Reperfusion Injury of the Rat Heart

Effects of melatonin on various manifestations of ischemia/reperfusion injury of the isolated perfused rat heart were examined. Ischemia- and reperfusion-induced ventricular arrhythmias were studied under constant flow in hearts subjected to 10, 15 or 25 min of regional ischemia (induced by LAD coronary artery occlusion) and 10-min reperfusion. Melatonin was added to the perfusion medium 5 min before ischemia at concentrations of 10 mol/l or 10 nmol/l and was present throughout the experiment. Recovery of the contractile function was evaluated under constant perfusion pressure after 20-min global ischemia followed by 40-min reperfusion. Hearts were treated with melatonin at a high concentration (10 mol/l) either 5 min before ischemia only (M1) or 5 min before ischemia and during reperfusion (M2) or only during reperfusion (M3). At the high concentration, melatonin significantly reduced the incidence of reperfusion-induced ventricular fibrillation and decreased arrhythmia score (10% and 2.2 ± 0.3, respectively) as compared with the corresponding untreated group (62% and 4.1 ± 0.3, respectively); the low concentration had no effect. This substance did not affect the incidence and severity of ischemic arrhythmias. Melatonin (M2, M3) significantly improved the recovery of the contractile function as compared with the untreated group; this protection did not appear if melatonin was absent in the medium during reperfusion (M1). Our results show that melatonin, in accordance with its potent antioxidant properties, effectively protects the rat heart against injury associated with reperfusion. It appears unlikely that melatonin is cardioprotective at physiological concentrations.     

Effectiveness of intensive medical therapy in type B aortic dissection: a single-center experience

OBJECTIVE: Although the mainstay of managing acute descending thoracic aortic dissection (ADTAD) remains medical, certain patients will require emergency surgery for complications of rupture or ischemia. This study evaluates factors that affect outcome and determines which patients previously treated surgically would have been eligible for endovascular repair. METHODS: A single-institution retrospective study was conducted of patients who presented with clinical signs of ADTAD that was confirmed by magnetic resonance angiography (MRA) or computed tomography (CT). All patients were admitted to the intensive care unit (ICU) and medically managed to maintain systolic blood pressure<120 mm Hg and heart rate<70 beats/min. Two treatment groups were identified: group 1 received medical treatment only; group 2 received medical treatment plus emergency surgery. Patient demographic and clinical data were correlated with 30-day group mortality and morbidity and need for emergency surgery. The MRA and CT scan images of group 2 were retrospectively reviewed to determine if currently available endovascular treatment could have been done. The Fisher exact test was used to compare between the groups, and P<.05 was considered significant. RESULTS: Between 1991 and 2005, 83 patients (55 men) were treated for ADTAD. The mean age was 67 years (range, 38 to 85). Sixty-eight patients (82%) had hypertension, three (3.6%) had Marfan syndrome, and 51 (62%) were smokers. Twenty-five (32%) of the patients were receiving beta-blocker therapy before the onset of their symptoms. Back pain was the most common initial symptom (72.2%). Emergency surgery was required in 19 patients (23%): 12 for rupture or impending rupture, four for mesenteric ischemia, and three for lower extremity ischemia. The need for emergency surgery was significantly higher in smokers (P=.03), in patients>70 years old (P=.035), and in patients who were not receiving beta-blocker therapy before the onset of symptoms (P=.023). The combined overall morbidity rate was 33%, and the mortality rate was 9.6%. Morbidity in group 2 was 64% and significantly higher than the 23% in group 1 (P=.00227). The mortality rate was also higher in group 2 at 31.5% compared with group 1 at 1.6% (P=.0004). Factors affecting the overall mortality included age>70 years (P=.057), previous abdominal aortic aneurysm repair (P=.018), tobacco use (P=.039), and the presence of leg pain at initial presentation (P=.013). As determined from the review of radiologic data, 11 of 13 patients with scans available for review in group 2 could have been treated with currently available endovascular grafts. CONCLUSIONS: Intensive medical therapies are effective in preventing early mortality associated with ADTAD. Predictably, the need for emergency surgery carries a high morbidity and mortality rate. Most patients in this series requiring emergency surgery could have been candidates for endovascular therapy had it been available.     

Acute cerebral vascular injury after subarachnoid hemorrhage and its prevention by administration of a nitric oxide donor

OBJECT: Structural changes in brain parenchymal vessels occur within minutes after subarachnoid hemorrhage (SAH). These changes include platelet aggregation, activation of vascular collagenases, and destruction of perivascular collagen IV. Because collagen IV is an important component of the basal lamina, the authors attempted to further define changes in vascular structure (length and luminal diameter) and their relationship to vascular permeability immediately after SAH. In addition, the authors explored whether such alterations were attenuated by administration of a nitric oxide (NO) donor. METHODS: Endovascular perforation was used to induce SAH in rats. Two sets of experiments were performed. The first established changes in vascular structure and permeability (collagen IV and endothelial barrier antigen [EBA] dual immunofluorescence) during the first 24 hours after SAH. In the second, the investigators examined the effects of an NO donor on vascular structure, permeability, and collagenase activity (in situ zymography). In this second study, animals received intravenous infusion of the NO donor S-nitrosoglutathione (GSNO, 1 microM/8 microl/min) 15 minutes after induction of SAH and were killed 3 hours after SAH onset. Controls were naive unoperated animals for the first study and saline-infused SAH animals for the second. The authors found a time-dependent decrease in area fraction, length, and luminal diameter of collagen IV- and EBA-immunofluorescent vessels after SAH. The greatest change occurred at 3 hours after onset of SAH. Administration of GSNO was associated with striking preservation of collagen IV and EBA immunofluorescence compared with saline treatment. Zymography indicated decreased collagenase activity in GSNO-treated SAH animals compared with saline-treated SAH animals. CONCLUSIONS: These results demonstrate changes in the structure and permeability of brain parenchymal microvessels after SAH and their reversal by treatment with an NO donor.     

Characterization of two mouse models of metastatic pheochromocytoma using bioluminescence imaging

Pheochromocytoma is the most common tumor of the adrenal medulla in adults. The lack of sensitive animal models of pheochromocytoma has hindered the study of this tumor and in vivo evaluation of antitumor agents. In this study we generated two sensitive luciferase models using bioluminescent pheochromocytoma cells: an experimental metastasis model to monitor tumor spreading and a subcutaneous model to monitor tumor growth and spontaneous metastasis. These models offer a platform for sensitive, non-invasive and real-time monitoring of pheochromocytoma primary growth and metastatic burden to follow the course of tumor progression and for testing relevant antitumor treatments in metastatic pheochromocytoma.     

Stress responsivity and HPA axis activity in juveniles: results from a home-based CO2 inhalation study

OBJECTIVE: A previous laboratory-based study found elevated cortisol levels in anxious children susceptible to CO(2)-induced panic, but the effects of parent diagnosis were not considered. The current home-based study tested the hypothesis that parental panic disorder and offspring response to CO(2) are associated with elevated cortisol levels in juvenile offspring. METHOD: A total of 131 offspring (ages 9-19) of parents with panic disorder, major depression, and no mental disorder underwent CO(2) inhalation. Parent and child diagnoses were assessed. Salivary cortisol was assayed before and after CO(2) inhalation. RESULTS: Neither parents with panic disorder, parents with major depression, or offspring anxiety predicted offspring cortisol levels. Independent of parent and child diagnoses, anxiety response to CO(2) predicted elevated cortisol levels in offspring. CONCLUSIONS: As in adults, anxiety response to CO(2) in juveniles is associated with elevated cortisol levels, but elevated cortisol levels are not related to parent or child diagnoses.     

Stent Migration and Folding in the Subclavian Vein during Subclavian Hemodialysis Catheter Placement

The role of stent placement in hemodialysis (HD) access intervention continues to evolve. As more stents are placed, new and unusual complications are coming to light. We describe a case in which an unsuccessful attempt to place a left subclavian dialysis catheter resulted in the inadvertent migration and folding of a previously deployed subclavian stent. Attempts to remove the stent with a snare were unsuccessful. Patency was restored to the access circuit by placing a new stent through the struts of the folded one. Clinical vascular practice guidelines for vascular access on the use of fluoroscopy for temporary HD catheter placement may need to be re-evaluated with the reported increase in stent placement in the US HD population.