Sensitivity of the ViroSeq HIV-1 genotyping system for detection of the K103N resistance mutation in HIV-1 subtypes A, C, and D

The US Food and Drug Administration-cleared ViroSeq HIV-1 Genotyping System (ViroSeq) and other population sequencing-based human immunodeficiency virus type 1 (HIV-1) genotyping methods detect antiretroviral drug resistance mutations present in the major viral population of a test sample. These assays also detect some mutations in viral variants that are present as mixtures. We compared detection of the K103N nevirapine resistance mutation using ViroSeq and a sensitive, quantitative point mutation assay, LigAmp. The LigAmp assay measured the percentage of K103N-containing variants in the viral population (percentage of K103N). We analyzed 305 samples with HIV-1 subtypes A, C, and D collected from African women after nevirapine administration. ViroSeq detected K103N in 100% of samples with >20% K103N, 77.8% of samples with 10 to 20% K103N, 71.4% of samples with 5 to 10% K103N, and 16.9% of samples with 1 to 5% K103N. The sensitivity of ViroSeq for detection of K103N was similar for subtypes A, C, and D. These data indicate that the ViroSeq system reliably detects the K103N mutation at levels above 20% and frequently detects the mutation at lower levels. Further studies are needed to compare the sensitivity of different assays for detection of HIV-1 drug resistance mutations and to determine the clinical relevance of HIV-1 minority variants.     

Neuroleptics antagonize nalbuphine antianalgesia.

To evaluate the role of sigma receptors in the sexually dimorphic antianalgesic effect of agonist-antagonist kappa opioids, 2 neuroleptics, haloperidol, a sigma receptor antagonist, and chlorpromazine, which has minimal effect at sigma receptors, were administered with the agonist-antagonist kappa opioid nalbuphine in patients with postoperative pain. Before surgical extraction of bony impacted mandibular third molar teeth, patients received haloperidol (1 mg), chlorpromazine (10 mg), or placebo by oral administration. After surgery, the pain intensity did not differ significantly between the 3 treatment groups, suggesting lack of analgesic effect produced by either haloperidol or chlorpromazine. All patients were then administered nalbuphine (5 mg, intravenous). As previously reported, the group that did not receive a preoperative neuroleptic exhibited sexually dimorphic analgesia, with women experiencing greater analgesia than men. Antianalgesia was also observed, with men experiencing late onset increased pain compared with baseline, starting approximately 1 hour after nalbuphine administration. Both neuroleptics blocked nalbuphine antianalgesia, resulting in enhanced analgesia and elimination of the sex differences. Because chlorpromazine and haloperidol enhanced nalbuphine analgesia and eliminated sexual dimorphism, the receptor at which neuroleptics act to antagonize the "antianalgesia" might be a common site of action to both drugs. PERSPECTIVE: This study demonstrates that neuroleptics can block the antianalgesic effect of agonist-antagonist kappa opioids. These findings could help inform the development of novel analgesics.     

Higher in utero and perinatal HIV infection risk in girls than boys

OBJECTIVE: This study analyzed mother-to-child HIV transmission rates by sex and exposure time for babies born to HIV-infected, untreated African women. METHODS: Data were analyzed from 2 independent studies done in Malawi during the 1990s. Infections were established by polymerase chain reaction on blood samples. Odds ratios (ORs) for transmission were examined by period at risk: in utero (infected in umbilical cord blood), perinatal (infected in 1st postnatal blood > or =4 weeks), and postnatal (later postnatal infection). RESULTS: Among 1394 singleton births, girls were more likely to become infected than boys. For in utero transmission, the OR was 1.4 (95% CI: 0.9 to 2.2). For transmission during early life (umbilical cord blood not available) the OR was 2.7 (95% CI: 1.5 to 4.9). However, transmission risks in the perinatal and postnatal infection periods did not differ in boys and girls. Among 303 tested twin-birth pairs, girls were at higher risk than boys for in utero (OR: 2.6; 95% CI: 1.2 to 5.8) and perinatal (OR: 1.9; 95% CI: 1.0 to 3.7) infection. Recognized mother-to-child transmission risk factors did not explain the higher risk of infection in girls. CONCLUSIONS: Girls were at higher risk of early (in utero and perinatal) HIV infection than boys. It is proposed that minor histocompatibility reactions between maternal lymphocytes and infant Y chromosome-derived antigens reduce the risk of HIV transmission in boys.     

The management of abuse: 2. Child abuse

The role of the GDP and the dental team in the recognition and management of child abuse is discussed. Information on the current legislation and protocols for referral are provided. CLINICAL RELEVANCE: This paper discusses child abuse and offers information and practical advice for the dental team.     

Gender differences in how men and women who are referred for IVF cope with infertility stress

BACKGROUND: Men and women use a variety of coping strategies to manage stress associated with infertility. Although previous research has helped us understand these coping processes, questions remain about gender differences in coping and the nature of the relationship between coping and specific types of infertility stress. METHODS: This study examined the coping behaviours of 1026 (520 women, 506 men) consecutively referred patients at a University-affiliated teaching hospital. Participants completed the Ways of Coping Questionnaire, Fertility Problem Inventory and the Dyadic Adjustment Scale. RESULTS: Women used proportionately greater amounts of confrontative coping, accepting responsibility, seeking social support and escape/avoidance when compared with men, whereas men used proportionately greater amounts of distancing, self-controlling and planful problem-solving. For men and women, infertility stress was positively related to escape/avoidance and accepting responsibility and negatively related to seeking social support, planful problem-solving and distancing. CONCLUSIONS: By analysing relative coping scores, this study identified key gender differences in how men and women cope with infertility. This was particularly true for men's coping processes that had previously remained hidden because of less frequent use of coping strategies when compared with women.     

Inhibition of dynamin completely blocks compensatory synaptic vesicle endocytosis

The ability of synapses to sustain signal propagation relies on rapid recycling of transmitter-containing presynaptic vesicles. Clathrin- and dynamin-mediated retrieval of vesicular membrane has an undisputed role in synaptic vesicle recycling. There is also evidence for other modes of vesicle retrieval, including bulk retrieval and the so-called kiss-and-run recycling. Whether dynamin in required for these other modes of synaptic vesicle endocytosis remains unclear. Here, we have tested the role of dynamin in synaptic vesicle endocytosis by using a small molecule called dynasore, which rapidly inhibits the GTPase activity of dynamin with high specificity. Endocytosis after sustained or brief stimuli was completely and reversibly blocked by dynasore in cultured hippocampal neurons expressing the fluorescent tracer synaptopHluorin. By contrast, dynasore had no effect on exocytosis. In the presence of dynasore, low-frequency stimulation led to sustained accumulation of synaptopHluorin and other vesicular proteins on the surface membrane at a rate predicted from net exocytosis. These vesicular components remained on surface membranes even after the stimulus was terminated, suggesting that all endocytic events rely on dynamin during low-frequency activity as well as in the period after it. Ultrastructural analysis revealed a reduction in the density of synaptic vesicles and the presence of endocytic structures only at synapses that were stimulated in the presence of dynasore. In sum, our data indicate that dynamin is essential for all forms of compensatory synaptic vesicle endocytosis including any kiss-and-run events.     

Characterisation of the associations and impact of symptoms in primary biliary cirrhosis using a disease specific quality of life measure

BACKGROUND/AIMS: Primary biliary cirrhosis (PBC) patients experience significant impairment to quality of life (QOL). Studies to date examining relative contributions of different symptoms to QOL impairment in PBC, and biological associations have been limited by the unavailability of appropriate disease specific symptom quantification modalities. METHODS: We applied the PBC-40, a recently developed, multi-domain disease specific QOL measure, to 54 PBC patients to explore the inter-relationship of different symptoms, their biological associations, and correlation with physical functioning measured by accelerometry. RESULTS: Two discrete and unrelated symptom complexes in PBC were identified focused on fatigue (together with cognitive and emotional dysfunction and other symptoms) and itch, with social dysfunction associating with both complexes. We confirmed no correlation between symptom severity and biological parameters of disease severity. There was a strong inverse correlation between physical activity (assessed over 6 days) and fatigue (P<0.005), but not between physical activity and Itch. Patients averaging <7,500 steps per day had over 75% higher fatigue scores than patients averaging >7,500 steps. CONCLUSIONS: We have demonstrated two independent symptom complexes in PBC centred around fatigue and itch, neither is associated with biological parameters of activity, and the fatigue-centred complex is associated with objective impairment of physical functioning.     

ACUTE AND SUBCHRONIC INHALATION NEUROTOXICITY OF PHOSPHINE IN THE RAT

Phosphine is a highly toxic gas used as a grain fumigant, as a dopant in semiconductor manufacturing, and in the production of organophosphines. To evaluate potential acute neurotoxic effects, 11 male and 11 female CD rats per group were exposed via wholebody inhalation for 4 h to mean concentrations of 0, 21, 28, or 40 ppm phosphine. A functional observational battery (FOB) consisting of quantitative and qualitative neurobehavioral parameters and motor activity was evaluated pretest, at the time of peak effect postexposure, approximately 1 h, and at 7 and 14 days postexposure. Six rats per sex per group were evaluated for neuropathologic effects 14 days postexposure. Exposure to phosphine did not alter FOB evaluations. A phosphine-related decrease in horizontal activity, vertical activity, total distance, and stereotypy was observed in the 21, 28, and 40 ppm phosphine exposure groups when compared to the control group on day 1, but not 7 or 14 days later. No phosphine-related neuropathologic changes were found. To evaluate potential subchronic neurotoxicity, 4 groups of 16 male and 16 female CD rats were exposed 6 h/day, 5 days/ wk, for 13 wk to either 0, 0.3, 1, or 3 ppm phosphine. In the 0 and 3 ppm groups an additional 6 rats per sex per group were used for a 2-wk recovery study. FOB and motor activity evaluations were conducted prior to study initiation and during wk 4, 8, and 13 of exposure. Following 13 wk of exposure, 6 rats per sex per group were randomly selected for neuropathology evaluation, as were the additional 6 rats per sex in the 0 and 3 ppm groups after 2 wk of recovery. There were no phosphine-related changes seen in the FOB, motor activity, or neuropathologic evaluations. Under the conditions of this subchronic inhalation study, exposure to 0.3, 1, or 3 ppm phosphine was not neurotoxic.     

AN EVALUATION OF CHANGES AND RECOVERY IN THE OLFACTORY EPITHELIUM IN MICE AFTER INHALATION EXPOSURE TO METHYLETHYLKETOXIME

Methylethylketoxime, also known as MEKO or 2-butanone oxime (CAS No. 96-29-7), is a clear, colorless to light yellow liquid at room temperature. It is an industrial antioxidant used as an antiskinning agent in alkyd paint, an industrial blocking agent for urethane polymers, and a corrosion inhibitor in industrial boilers, and can be found in some adhesives and silicone caulking products. Male CD-1 mice were exposed 6 h/day, 5 days/wk, for 1, 2, 4, or 13 wk via whole-body inhalation exposures to MEKO vapor concentrations of 0, 3 ± 0.1, 10 ± 0.3, 30 ± 1, or 100 ± 2 ppm (10 mice/group/interval). Satellite animals were removed after 1, 2, 4, or 13 wk of exposure and allowed to recover for 4 or 13 wk (5 mice/group/interval). After termination, the nasal turbinates were evaluated microscopically, and cross-sectional nasal maps of the lesions were prepared. At the end of the 1-, 2-, 4-, and 13-wk exposure periods, degeneration of the olfactory epithelium lining the dorsal meatus was seen in the anterior region of the nasal cavity. In a few instances, the olfactory epithelium covering the tips of the nasoturbinal scrolls projecting into the dorsal region of the nasal cavity was also degenerated. Large areas of olfactory epithelium lying laterally and posteriorly were unaffected. In general, approximately 10% or less of the total olfactory tissue was affected. In several instances, the degenerated olfactory epithelium was reepithelialized by squamous/squamoid and/or respiratory types of epithelium. Degeneration, which was dose related in incidence and severity, was seen in mice exposed to 30 and 100 ppm after 1 wk of exposure and in several mice exposed to 10 ppm after 13 wk of exposure. The incidence and severity of the degeneration present after 1 wk of exposure did not increase with the longer exposures. The olfactory degeneration was reversible. Recovery was complete within 4 wk following exposures at 10 ppm and nearly complete within 13 wk after exposures at 30 and 100 ppm. A no-observed-effect level (NOEL) for the olfactory degeneration was considered to be 3 ppm.