A case‐control study of factors associated with resolution of hepatitis C viremia in former blood donors (CME)

BACKGROUND: Nucleic acid testing (NAT) is performed on blood collected in the United States allowing for the classification of hepatitis C virus (HCV) antibody–positive donors into resolved and chronic hepatitis C infections. We report a case‐control study of factors associated with HCV resolution. STUDY DESIGN AND METHODS: Blood donors with resolved (HCV antibody positive, RNA negative defined as “cases”) or chronic (HCV antibody positive, RNA positive defined as “controls”) based on their index donation HCV test results were enrolled. Participants completed a risk factor, symptoms, and treatment questionnaire followed by HCV antibody, HCV RNA, and liver biochemical testing. RESULTS: We enrolled 100 cases and 202 controls. In a multivariate logistic regression model, significant independent effects for spontaneous viral clearance were observed for African American (inverse; odds ratio [OR], 0.11; 95% confidence interval [CI], 0.01‐0.87), autologous blood donation (OR, 4.70; 95% CI, 2.02‐10.94), alcohol intake (OR, 2.39; 95% CI, 1.13‐5.03), and transfusion before May 1990 (inverse; OR, 0.36; 95% CI, 0.14‐0.91). Cases admitting injection drug use had shorter time since first injection than did controls. Forty‐nine index RNA positive controls received antiviral therapy and 25 (51%) were RNA negative at enrollment; surprisingly several RNA‐negative cases received liver biopsies and/or antiviral treatment. CONCLUSIONS: We document the role donor screening plays in the identification, subsequent medical evaluation, and treatment among individuals who presumably did not know that they were at risk for HCV infection. Additionally, we confirmed race/ethnicity as a determinant of clearance and suggest infectious dose and route of infection may play a role in clearance.     

Preparation and Study of Composite Materials of the NiAl-Cr-Mo-Nanoparticles (ZrO2, MgAl2O4) System

Materials based on the NiAl-Cr-Mo system with zirconium oxide or aluminum-magnesium spinel nanoparticle small additions were obtained by spark plasma sintering. Thermodynamic modeling was carried out to predict the phase formation in the NiAl-Cr-Mo system and its change depending on temperature, considering the presence of a small amount of carbon in the system. The phase composition and microstructure of materials were studied. NiAl (B2) and CrMo phases were found in the sintered samples. Bending strength measurements at different temperatures shows that nanoparticles of insoluble additives lead to an increase in bending strength, especially at high temperatures. A fractographic analysis of the sample’s fractures shows their hybrid nature and intercrystalline fracture, which is confirmed by the clearly visible matrix grains similar to cleavage. The maximum strength at 700 °C (475 MPa) was found for material with the addition of 0.1 wt.% zirconium oxide nanoparticles. In the study of internal friction, typical peaks of a nickel-aluminum alloy were found in the temperature ranges of 150–200 °C and 350–400 °C.     

Making an impossible mission possible

Cardiovascular disease (CVD) is widespread in developing countries. Hypertension is a major contributor of CVD. Left ventricular hypertrophy (LVH) is a risk marker in hypertensive populations. Identification of LVH and treatment of high-risk patients can result in more effective use of the limited resources. LVH is diagnosed by echocardiography, often unavailable in developing countries. In Gambia, we used a hand-carried ultrasound (HCU) to examine 1,997 people. Seventeen percent had hypertension; of these, LVH was found in 65%. The battery-powered HCU permits clinicians to detect LVH in areas with limited access to diagnostic equipment, allowing identification of a high-risk hypertensive population.     

A case report on the role of plasma exchange in the management of a massive amlodipine besylate intoxication

Therapeutic plasma exchange is a procedure used to remove pathologic substances from a patient's blood that has proven useful in some cases of drug overdose. Overdose by calcium channel blocker antihypertensive agents has been shown to be a cause of significant morbidity and can often times prove fatal. These agents cause systemic hypotension by inhibiting cell membrane calcium channels, which leads to a slowing of intracardiac electric conduction with consequent impairment of myocardial function and widespread vasodilation. Shock and metabolic acidosis result from the persistent hypotension. In high doses, calcium channel blocking agents cause insulin resistance. We describe the case of a previously healthy young woman who ingested a massive dose of amlodipine and was treated by therapeutic plasma exchange after non-responsiveness to conventional therapy. The case illustrates the need for utilization of therapeutic plasma exchange in the emergency management of certain cases of severe amlodipine overdose.     

The responsiveness of the OAB-q among OAB patient subgroups

AIMS: Although the majority of patients with overactive bladder (OAB) are continent, most patient-reported outcome measures for OAB were designed for patients with urinary incontinence. The overactive bladder questionnaire (OAB-q) was developed to assess symptom bother and HRQL among both continent and incontinent OAB patients; however, the responsiveness of the OAB-q among continent patients has not been evaluated. The purpose of this analysis was to assess the responsiveness of the OAB-q among OAB patient subgroups with a focus on continent patients. METHODS: Post-hoc analyses were conducted from two 12-week trials of tolterodine for the treatment of OAB. Patients completed the OAB-q and daily bladder diaries (assessing frequency, urgency, and incontinence episodes) at baseline, 4 weeks, and 12 weeks. Three patient subgroups were identified on the basis of continence status at all three timepoints: (1) continent; (2) incontinent; and (3) incontinent at baseline and continent by Week 12 (ITC). General linear models were used to compare changes from baseline, and Spearman correlations assessed the association between OAB-q changes and bladder diary changes. Effect sizes were computed separately for each group. RESULTS: A total of 262 continent, 552 incontinent, and 397 ITC patients were included in this analysis. Continent patients tended to be younger than incontinent patients, and patients were predominantly female, although continent patients had the highest percentage of male patients in both studies. Compared with continent patients, patients who were incontinent at baseline tended to have greater symptom bother and lower HRQL at baseline. All OAB-q change scores were consistently greatest for the ITC group (12.1-33.9), and greater for continent patients (10.8-28.6) than for incontinent patients (7.6-20.1). All three groups of patients experienced reductions in frequency and urgency episodes, and these changes were significantly correlated with changes in the OAB-q scales. Among all three groups, effect sizes were in the moderate-to-large range for all OAB-q subscales except Social Interaction. CONCLUSIONS: The OAB-q is highly responsive to change between continent and incontinent patients with OAB, and is a valid tool for measuring treatment outcomes among continent OAB patients.     

Methods for Lymphatic Vessel Culture and Gene Transfection

Objective: To develop the techniques needed for the specific gene/protein targeting transfection experiments in isolated lymphatic vessels, we completed two major tasks: 1) optimize the experimental conditions to maintain the viability of isolated rat lymphatic vessels in culture for sufficiently long periods of time to permit knockdown or overexpression of selected proteins/genes and 2) develop effective transfection protocols for lymphatic muscle and endothelial cells in intact lymphatic vessels without nonspecific impairment of lymphatic contractile function due to the transfection protocol itself. Methods: Experimental protocols were developed for the maintenance of isolated lymphatic vessels under nonpressurized and pressurized conditions for 3–12 days in culture and for adenoviral gene transfection of the lymphatic muscle and endothelial cells. Results: The data demonstrate the effectiveness of the newly developed experimental protocols for the maintenance of isolated rat mesenteric lymphatic vessels and thoracic duct in culture up to 3–12 days without significant impairment of the parameters of their pumping and effective adenoviral/GFP transfection of lymphatic endothelial and muscle cells in isolated rat mesenteric lymphatic vessels. Conclusions : These experimental techniques will extend the set of the modern experimental tools available to researchers investigating the physiology of lymphatic function.