Transfer RNA-mediated restoration of potassium current and electrical correction in premature termination long-QT syndrome hERG mutants

Disease-causing premature termination codons (PTCs) individually disrupt the functional expression of hundreds of genes and represent a pernicious clinical challenge. In the heart, loss-of-function mutations in the hERG potassium channel account for approximately 30% of long-QT syndrome arrhythmia, a lethal cardiac disorder with limited treatment options. Premature termination of ribosomal translation produces a truncated and, for potassium channels, a potentially dominant-negative protein that impairs the functional assembly of the wild-type homotetrameric hERG channel complex. We used high-throughput flow cytometry and patch-clamp electrophysiology to assess the trafficking and voltage-dependent activity of hERG channels carrying patient PTC variants that have been corrected by anticodon engineered tRNA. Adenoviral-mediated expression of mutant hERG channels in cultured adult guinea pig cardiomyocytes prolonged action potential durations, and this deleterious effect was corrected upon adenoviral delivery of a human ArgUGA tRNA to restore full-length hERG protein. The results demonstrate mutation-specific, context-agnostic PTC correction and elevate the therapeutic potential of this approach for rare genetic diseases caused by stop codons.

Selective posttranslational inhibition of CaVβ1-associated voltage-dependent calcium channels with a functionalized nanobody

Ca²⁺ influx through high-voltage-activated calcium channels (HVACCs) controls diverse cellular functions. A critical feature enabling a singular signal, Ca²⁺ influx, to mediate disparate functions is diversity of HVACC pore-forming α₁ and auxiliary Ca_Vβ₁-Ca_Vβ₄ subunits. Selective Ca_Vα₁ blockers have enabled deciphering their unique physiological roles. By contrast, the capacity to post-translationally inhibit HVACCs based on Ca_Vβ isoform is non-existent. Conventional gene knockout/shRNA approaches do not adequately address this deficit owing to subunit reshuffling and partially overlapping functions of Ca_Vβ isoforms. Here, we identify a nanobody (nb.E8) that selectively binds Ca_Vβ₁ SH3 domain and inhibits Ca_Vβ₁-associated HVACCs by reducing channel surface density, decreasing open probability, and speeding inactivation. Functionalizing nb.E8 with Nedd4L HECT domain yielded Chisel-1 which eliminated current through Ca_Vβ₁-reconstituted Ca_V1/Ca_V2 and native Ca_V1.1 channels in skeletal muscle, strongly suppressed depolarization-evoked Ca²⁺ influx and excitation-transcription coupling in hippocampal neurons, but was inert against Ca_Vβ₂-associated Ca_V1.2 in cardiomyocytes. The results introduce an original method for probing distinctive functions of ion channel auxiliary subunit isoforms, reveal additional dimensions of Ca_Vβ₁ signaling in neurons, and describe a genetically-encoded HVACC inhibitor with unique properties.

Targeted deubiquitination rescues distinct trafficking-deficient ion channelopathies

Impaired protein stability/trafficking underlies diverse ion channelopathies and represents an unexploited unifying principle to develop common treatments for otherwise dissimilar diseases. Ubiquitination limits ion channel surface density, but targeting this pathway for basic study or therapy is challenging because of its prevalent role in proteostasis. We developed engineered deubiquitinases (enDUBs) that enable ubiquitin chain removal selectively from target proteins to rescue functional expression of disparate mutant ion channels underlying Long QT syndrome (LQT1) and cystic fibrosis (CF). In a LQT1 cardiomyocyte model, enDUB treatment restored delayed rectifier K⁺ currents and normalized action potential duration. CF-targeted enDUBs synergistically rescued common (F508del) and pharmacotherapy-resistant (N1303K) CF mutations when combined with the FDA-approved drugs, Orkambi and Trikafta. Altogether, targeted deubiquitination via enDUBs provides a powerful protein stabilization method that not only corrects diverse diseases caused by impaired ion channel trafficking, but also introduces a new tool for deconstructing the ubiquitin code in situ.

Influenza vaccination in India: position paper of Indian Academy of Pediatrics, 2013

Burden of Influenza is significantly higher in developing countries as compared to developed countries, but the data on the disease burden is less well defined in most of the developing countries including India, and consequently, constraints evolving strategies for prioritization of measures to prevent and control it. The swine flu or A(H1N1) pandemic is on the wane but the virus continues to circulate causing sporadic outbreaks even in 2013. The A(H1N1)pdm09 has replaced the previous circulating seasonal A (H1N1) virus and acquired the status of a seasonal virus. Limited influenza activity is usually seen throughout the year in India with a clear peaking during the rainy season. The rainy season in the country lasts from June to August in all the regions except Tamil Nadu where it occurs from October to December. IAP recommends the ideal time for offering influenza vaccines is just before the onset of rainy season. The efficacy/effectiveness data of trivalent inactivated influenza vaccines are also presented in different age groups and different categories of individuals. The IAP maintains its earlier recommendations of using the current trivalent inactivated influenza vaccine in all children with risk factors but not as a universal measure. IAP has now prioritized different target groups for influenza vaccination based on contribution of the group to the overall influenza burden, disease severity, and vaccine effectiveness in different age groups and categories. The current trivalent inactivated influenza vaccines incorporate the 2009 pandemic strain also, hence avert the need of a separate A (H1N1) vaccine. IAP stresses the need of more refined surveillance; large scale studies on effectiveness of seasonal influenza vaccines in Indian children, and more effective, properly matched, higher-valent influenza vaccines.

Delta opioid receptors presynaptically regulate cutaneous mechanosensory neuron input to the spinal cord dorsal horn

Cutaneous mechanosensory neurons detect mechanical stimuli that generate touch and pain sensation. Although opioids are generally associated only with the control of pain, here we report that the opioid system in fact broadly regulates cutaneous mechanosensation, including touch. This function is predominantly subserved by the delta opioid receptor (DOR), which is expressed by myelinated mechanoreceptors that form Meissner corpuscles, Merkel cell-neurite complexes, and circumferential hair follicle endings. These afferents also include a small population of CGRP-expressing myelinated nociceptors that we now identify as the somatosensory neurons that coexpress mu and delta opioid receptors. We further demonstrate that DOR activation at the central terminals of myelinated mechanoreceptors depresses synaptic input to the spinal dorsal horn, via the inhibition of voltage-gated calcium channels. Collectively our results uncover a molecular mechanism by which opioids modulate cutaneous mechanosensation and provide a rationale for targeting DOR to alleviate injury-induced mechanical hypersensitivity.

Pre- and postsynaptic inhibitory control in the spinal cord dorsal horn

Sensory information transmitted to the spinal cord dorsal horn is modulated by a complex network of excitatory and inhibitory interneurons. The two main inhibitory transmitters, GABA and glycine, control the flow of sensory information mainly by regulating the excitability of dorsal horn neurons. A presynaptic action of GABA has also been proposed as an important modulatory mechanism of transmitter release from sensory primary afferent terminals. By inhibiting the release of glutamate from primary afferent terminals, activation of presynaptic GABA receptors could play an important role in nociceptive and tactile sensory coding, while changes in their expression or function could be involved in pathological pain conditions, such as allodynia.

3.4 Gbit/s visible optical wireless transmission based on RGB LED

In this paper, we experimentally realized a gigabit-class indoor visible light communication system using commercially available RGB White LED and exploiting an optimized DMT modulation. We achieved data rate of 1.5 Gbit/s with single channel and 3.4 Gbit/s by implementing WDM transmission at standard illumination levels. In both experiments, the resulting bit error ratios were below the FEC limit. To the best of our knowledge, these values are the highest ever achieved in VLC systems.

Interdistrict variations in child health status and health services utilization: lessons for health sector priority setting and planning from a cross-sectional survey in rural India

BACKGROUND

There are limited data on interdistrict variations in child health status and health services utilization within the states of India. We conducted this study to identify and understand district-wise variations in child morbidity, mortality, healthcare seeking, and the status of health facilities in India.

METHODS

A cross-sectional population-based cluster survey was conducted from April to July 2007 in 16 districts of eight states in India. Two districts with similar demographic profile and health criteria were selected from each study state.

RESULTS

A total of 216 794 households and 24 812 under-5 children were surveyed. There were wide interdistrict variations in the health status of children within the same state and between different states across India. Interdistrict difference of >5 points/1000 live-births was found for infant mortality rate and under-5 mortality rate in all eight study states, while in six out of eight states this difference was >10 points/1000 live-births. Four states had a difference of >10 points/1000 live-births between respective districts for neonatal mortality rate. The interdistrict differences were also noted in childhood morbidity and health-seeking behaviour. Analysis of proportion of health facilities conforming to Indian public health standards revealed that the difference was m10% for availability of vaccines in five states, emergency services in three, laboratory services and logistics in four each, and referral facility in three of the eight study states.

CONCLUSION

This study underscores an important information gap in the country where planners seem to rely heavily on a few selected national-level databases that may not be adequate at the micro level. The current process of sporadic health surveys also appears inadequate and inappropriate. There is a need for district-specific data for planning, improving quality of service and generating demand for health service utilization to improve child survival in India. The findings of this study may prove useful for child health programme planning in India.

An in vitro assay system for studying synapse formation between nociceptive dorsal root ganglion and dorsal horn neurons

Synapses between nociceptive dorsal root ganglion (DRG) neurons and spinal cord dorsal horn neurons represent the first loci for transmission of painful stimuli. Our knowledge of the molecular organization and development of these synapses is sparse due, partly, to a lack of a reliable model system that reconstitutes synaptogenesis between these two neuronal populations. To address this issue, we have established an in vitro assay system consisting of separately purified DRG neurons and dorsal horn neurons on astrocyte microislands. Using immunocytochemistry, we have found that 97%, 93%, 98%, 96%, and 94% of DRG neurons on these microislands express markers often associated with nociceptive neurons including Substance P, TRPV1, calcitonin-gene related peptide (CGRP), TrKA, and peripherin, respectively. Triple labeling with these nociceptive-like markers, synaptic vesicle marker Vglut2 and using MAP2 as a dendritic marker revealed the presence of nociceptive-like markers at synaptic terminals. Using this immunocytochemical approach, we counted contact points as overlapping MAP2/Vglut2 puncta and showed that they increased with time in culture. Single and dual patch-clamp recordings showed that overlapping Vglut2/MAP2 puncta observed after a few days in culture are likely to be functional synapses between DRG and dorsal horn neurons in our in vitro assay system. Taken together, these data suggest our co-culture microisland model system consists of mostly nociceptive-like DRG neurons that express presynaptic markers and form functional synapses with their dorsal horn partners. Thus, this model system may have direct application for studies on factors regulating development of nociceptive DRG/dorsal horn synapses.

The Panton-Valentine leukocidin vaccine protects mice against lung and skin infections caused by Staphylococcus aureus USA300

Methicillin-resistant Staphylococcus aureus is increasingly responsible for staphylococcal infections in the community. A large percentage of the community-acquired methicillin-resistant (CA-MRSA) strains in the USA produce Panton-Valentine leukocidin (PVL), which is associated with severe infections. The virulence of the clinical CA-MRSA strain USA300 was compared to that of its isogenic pvl-deleted mutant, and it was shown that PVL contributes to lung and muscle tissue destruction, respectively, in murine necrotizing pneumonia and skin infection models. Mice infected with the USA300 strain developed a dominant anti-PVL response. The PVL subunits were therefore tested as vaccinogens against this isolate, and their vaccine efficacy correlated with both the route of vaccination and infection. These data suggest that PVL is a virulence factor in murine CA-MRSA infections.

Histidine phosphorylation of the potassium channel KCa3.1 by nucleoside diphosphate kinase B is required for activation of KCa3.1 and CD4 T cells

The Ca2+ -activated K+ channel KCa3.1 is required for Ca2+ influx and the subsequent activation of B and T cells. Inhibitors of KCa3.1 are in development to treat autoimmune diseases and transplant rejection, underscoring the importance in understanding how these channels are regulated. We show that nucleoside diphosphate kinase B (NDPK-B), a mammalian histidine kinase, functions downstream of PI(3)P to activate KCa3.1. NDPK-B directly binds and activates KCa3.1 by phosphorylating histidine 358 in the carboxyl terminus of KCa3.1. Endogenous NDPK-B is also critical for KCa3.1 channel activity and the subsequent activation of CD4 T cells. These findings provide one of the best examples whereby histidine phosphorylation regulates a biological process in mammals, and provide an example whereby a channel is regulated by histidine phosphorylation. The critical role for NDPK-B in the reactivation of CD4 T cells indicates that understanding NDPK-B regulation should uncover novel pathways required for T cell activation.

Phosphatidylinositol-3 phosphatase myotubularin-related protein 6 negatively regulates CD4 T cells

Intracellular Ca2+ levels rapidly rise following cross-linking of the T-cell receptor (TCR) and function as a critical intracellular second messenger in T-cell activation. It has been relatively under appreciated that K+ channels play an important role in Ca2+ influx into T lymphocytes by helping to maintain a negative membrane potential which provides an electrochemical gradient to drive Ca2+ influx. Here we show that the Ca2+-activated K+ channel, KCa3.1, which is critical for Ca2+ influx in reactivated naive T cells and central memory T cells, requires phosphatidylinositol-3 phosphatase [PI(3)P] for activation and is inhibited by the PI(3)P phosphatase myotubularin-related protein 6 (MTMR6). Moreover, by inhibiting KCa3.1, MTMR6 functions as a negative regulator of Ca2+ influx and proliferation of reactivated human CD4 T cells. These findings point to a new and unexpected role for PI(3)P and the PI(3)P phosphatase MTMR6 in the regulation of Ca2+ influx in activated CD4 T cells and suggest that MTMR6 plays a critical role in setting a minimum threshold for a stimulus to activate a T cell.

Specificity of the myotubularin family of phosphatidylinositol-3-phosphatase is determined by the PH/GRAM domain

Myotubularins (MTM) are a large subfamily of lipid phosphatases that specifically dephosphorylate at the D3 position of phosphatidylinositol 3-phosphate (PI(3)P) in PI(3)P and PI(3,5)P2. We recently found that MTMR6 specifically inhibits the Ca2+-activated K+ channel, KCa3.1, by dephosphorylating PI(3)P. We now show that inhibition is specific for MTMR6 and other MTMs do not inhibit KCa3.1. By replacing either or both of the coiled-coil (CC) and pleckstrin homology/GRAM (PH/G) domains of MTMs that failed to inhibit KCa3.1 with the CC and PH/G domains of MTMR6, we found that chimeric MTMs containing both the MTMR6 CC and PH/G domains functioned like MTMR6 to inhibit KCa3.1 channel activity, whereas chimeric MTMs containing either domain alone did not. Immunofluorescent microscopy demonstrated that both the MTMR6 CC and PH/G domains are required to co-localize MTMR6 to the plasma membrane with KCa3.1. These findings support a model in which two specific low affinity interactions are required to co-localize MTMR6 with KCa3.1: 1) between the CC domains on MTMR6 and KCa3.1 and (2) between the PH/G domain and a component of the plasma membrane. Our inability to detect significant interaction of the MTMR6 G/PH domain with phosphoinositides suggests that this domain may bind a protein. Identifying the specific binding partners of the CC and PH/G domains on other MTMs will provide important clues to the specific functions regulated by other MTMs as well as the mechanism(s) whereby loss of some MTMs lead to disease.

Effects of extracellular matrix-degrading proteases matrix metalloproteinases 3 and 9 on spatial learning and synaptic plasticity

Rats learning the Morris water maze exhibit hippocampal changes in synaptic morphology and physiology that manifest as altered synaptic efficacy. Learning requires structural changes in the synapse, and multiple cell adhesion molecules appear to participate. The activity of these cell adhesion molecules is, in large part, dependent on their interaction with the extracellular matrix (ECM). Given that matrix metalloproteinases (MMPs) are responsible for transient alterations in the ECM, we predicted that MMP function is critical for hippocampal-dependent learning. In support of this, it was observed that hippocampal MMP-3 and -9 increased transiently during water maze acquisition as assessed by western blotting and mRNA analysis. The ability of the NMDA receptor channel blocker MK801 to attenuate these changes indicated that the transient MMP changes were in large part dependent upon NMDA receptor activation. Furthermore, inhibition of MMP activity with MMP-3 and -9 antisense oligonucleotides and/or MMP inhibitor FN-439 altered long-term potentiation and prevented acquisition in the Morris water maze. The learning-dependent MMP alterations were shown to modify the stability of the actin-binding protein cortactin, which plays an essential role in regulating the dendritic cytoskeleton and synaptic efficiency. Together these results indicate that changes in MMP function are critical to synaptic plasticity and hippocampal-dependent learning.

Is interferon-α and retinoic acid combination along with radiation superior to chemo-radiation in the treatment of advanced carcinoma of cervix?

Locally advanced cervical cancers comprise a large majority of the gynecologic cancers in India and other developing countries. Concurrent chemo-radiation has improved the survival of high risk stage I and stage II cervical cancers. There is no evidence that the same survival benefit has been achieved with chemo-radiation in stage III and stage IV disease. Interferon-alpha and Retinoic acid have synergistic anti-proliferative activity. In combination with radiation, they substantially enhance the sensitivity of the squamous carcinoma cells to radiation. Based on these observations from the in vitro studies, a few clinical trials have evaluated the combination of interferon-alpha and Retinoic acid, concomitant with radiation, to treat cervical cancers. The results from these early trials were encouraging and the combination had minimal toxicities. However, till date, no phase III randomized controlled trial has been done to evaluate this therapeutic modality.

Phosphatidylinositol 3-phosphate indirectly activates KCa3.1 via 14 amino acids in the carboxy terminus of KCa3.1

KCa3.1 is an intermediate conductance Ca2+-activated K+ channel that is expressed predominantly in hematopoietic cells, smooth muscle cells, and epithelia where it functions to regulate membrane potential, Ca2+ influx, cell volume, and chloride secretion. We recently found that the KCa3.1 channel also specifically requires phosphatidylinositol-3 phosphate [PI(3)P] for channel activity and is inhibited by myotubularin-related protein 6 (MTMR6), a PI(3)P phosphatase. We now show that PI(3)P indirectly activates KCa3.1. Unlike KCa3.1 channels, the related KCa2.1, KCa2.2, or KCa2.3 channels do not require PI(3)P for activity, suggesting that the KCa3.1 channel has evolved a unique means of regulation that is critical for its biological function. By making chimeric channels between KCa3.1 and KCa2.3, we identified a stretch of 14 amino acids in the carboxy-terminal calmodulin binding domain of KCa3.1 that is sufficient to confer regulation of KCa2.3 by PI(3)P. However, mutation of a single potential phosphorylation site in these 14 amino acids did not affect channel activity. These data together suggest that PI(3)P and these 14 amino acids regulate KCa3.1 channel activity by recruiting an as yet to be defined regulatory subunit that is required for Ca2+ gating of KCa3.1.

A glycosylation site, 60SGTS63, of p67 is required for its ability to regulate the phosphorylation and activity of eukaryotic initiation factor 2alpha

Eukaryotic initiation factor 2- (eIF2-) associated glycoprotein p67 blocks eIF2alpha phosphorylation by kinases, and its N-terminal 1-97 amino acid segment can induce efficient translation. To investigate whether glycosylation at the serine/threonine clusters at this region is important in protein synthesis, we selected (27)TSST(30) and (60)SGTS(63) clusters for further analysis. By site-directed mutagenesis, (27)TSST(30) and (60)SGTS(63) clusters were substituted with (27)AAGA(30) and (60)AGAA(63) amino acid residues in full-length p67, and their EGFP fusions were constitutively expressed in rat tumor hepatoma cells (KRC-7). The (60)AGAA(63) mutant blocked eIF2alpha phosphorylation less than either wild-type p67 or the (27)AAGA(30) mutant. The (60)AGAA(63) mutant also showed a low level of protein synthesis rate, a lower level of glycosylation, increased turnover rate, and weaker binding to eIF2alpha. These results suggest that glycosylation within the (60)SGTS(63) sequence of p67 plays an important role in its stability and thus its regulation of protein synthesis by modulating the phosphorylation of the alpha-subunit of eIF2.

STD in Bangladesh's trucking industry: prevalence and risk factors

OBJECTIVES

This study characterises the prevalence of a broad spectrum of sexually transmitted diseases (STDs) (herpes simplex virus 2, syphilis, chlamydia, gonorrhoea), and examines associations between risk factors and infection in men working in Bangladesh's trucking industry. Given the high risk sexual behaviours of truck drivers and helpers in many contexts, as well as the direct health effects of STDs and their role in facilitating HIV transmission, it is important to understand the prevalence of STDs and associated risk factors in this population.

METHODS

A cross sectional study was conducted at Tejgaon truck stand, one of the largest truck stands in Dhaka, the capital city. The study group, comprising 388 truck drivers and helpers, was selected via a two tiered sampling strategy. Of 185 trucking agencies based at the truck stand, 38 agencies were randomly selected, and a mean of 10 subjects (drivers/helpers) were recruited from each agency. Urine and blood samples were collected from subjects after an interview about their lifestyle and a comprehensive physical examination. Gold standard laboratory tests were conducted for the detection of STD. Multiple logistic regression was used to assess associations between infections and potential risk factors.

RESULTS

The levels of prevalence of disease were HSV-2 (25.8%), serological syphilis (5.7%), gonorrhoea (2.1%), chlamydia (0.8%). For infection with any bacterial STD (syphilis, gonorrhoea, or chlamydia) the only significant risk factor was having sex with a commercial sex worker in the past year (OR=3.54; CI=1.29-9.72). For HSV-2, truck helpers working primarily on interdistrict routes were significantly more likely to be infected than drivers working on these routes (OR=2.51, CI=1.13--5.55).

CONCLUSIONS

The high prevalence of HSV-2, and to a lesser extent syphilis, and the low levels of condom use despite high numbers of casual sexual partners, illustrate the importance of promoting condom use, particularly in commercial sexual encounters, to men in Bangladesh's trucking industry.

Protection of translation initiation factor eIF2 phosphorylation correlates with eIF2-associated glycoprotein p67 levels and requires the lysine-rich domain I of p67

The rate of protein synthesis in mammals is largely regulated by phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 (eIF2) that is modulated by the cellular glycoprotein, p67, due to its protection of eIF2alpha phosphorylation (POEP) activity. At the N-terminus of p67, there are three unique domains, and at the C-terminus there is a conserved amino acid sequence. To analyze the importance of these domains, C-terminal deletion mutants of rat p67 were expressed constitutively in KRC-7 cells. In these cells, the phosphorylation level of the alpha-subunit of eIF2 was determined, and it was found that expression of the 1-97 amino acid segment of rat p67 increases POEP activity in vivo, and induces the endogenous levels of p67. These cells also show increased growth rate, and efficient translation of chloramphenicol acetyltransferase and beta-galactosidase reporter genes. At the N-terminus of p67, there are two unique domains: a lysine-rich domain I with the sequence (36)KKKRRKKKK(44), and an acidic residue-rich domain with the sequence (77)EEKEKDDDDEDGDGD(91). Substitution of lysine-rich domain I with (36)NMKSGNKTQ(44) in rat recombinant p67 resulted in the inhibition of its POEP activity, and substitution of the acidic residue-rich domain with (77)QNIQKALEPEAGDGA(91), resulted in no inhibition of POEP activity in KRC-7 cells. Taken together, our data suggest that protection of translation initiation factor eIF2 phosphorylation correlates with eIF2-associated glycoprotein p67 levels and requires the lysine-rich domain I of p67.

Prevalence of infectious diseases in Bangladeshi women living adjacent to a truck stand: HIV/STD/hepatitis/genital tract infections

BACKGROUND

Little is known about infection rates for human immunodeficiency virus (HIV) and other diseases that can be transmitted sexually in Bangladeshi women who may be at intermediate levels of risk--that is, women who are not commercial sex workers (CSWs) but whose sexual contacts may include men at high risk for STD. This study examines HIV/hepatitis/STD and other genital tract infections in women living near Tejgaon truck stand in Dhaka, Bangladesh.

METHODS

This population based study was conducted from January to December 1998. A random sample of 384 women provided urine and blood samples and participated in an interview; 261 of them also had a physical examination in which vaginal and cervical specimens were taken. Laboratory tests included PCR on urine and cervical swabs for gonorrhoea and chlamydia, culture for trichomoniasis, serology tests for syphilis, herpes simplex 2, hepatitis B, C, D, HIV1, HIV2, and clinical diagnoses of other genital tract infections.

RESULTS

None of the participants tested positive for HIV. In the 261 women who had a physical examination, trichomoniasis was detected in 19.5%, chlamydia in 3.4%, gonorrhoea in 5.4%, bacterial vaginosis in 37.2%, and candidiasis in 10%. In the full sample of 384 women, with tests of urine and blood, prevalence of infection with chlamydia, gonorrhoea, syphilis, and herpes simplex 2 was detected in 0%, 6.3%, 5.7%, and 32% respectively. Almost 50% of the subjects had ever been exposed to hepatitis B, 3.6% were currently infective, 1.6% had hepatitis C, and none had hepatitis D.

CONCLUSION

The high prevalence of certain of these infectious diseases indicates the need to implement prevention interventions with these women and, perhaps more importantly, with their male partners. Qualitative research is needed to provide insights into their sexual behaviour and the contexts in which high risk behaviours occur.

Human immunodeficiency virus, hepatitis B, C and D in Bangladesh's trucking industry: prevalence and risk factors

BACKGROUND

Human immunodeficiency virus (HIV) and hepatitis B and C, viral infections with shared percutaneous, mucosal and perinatal routes of transmission, are responsible for serious morbidity and mortality globally. In Bangladesh there is a dearth of research on prevalence and risk factors for these diseases. This study examines the prevalence of HIV and hepatitis (B, C, D) and risk factors associated with infection in men in Bangladesh's trucking industry (drivers and helpers on trucks), a population at risk for sexually transmitted infections.

METHODS

The study population comprised 388 men (245 drivers, 143 helpers) working out of Tejgaon truck stand in Dhaka, Bangladesh. Subjects were selected through a two-tiered sampling strategy. Of 185 trucking agencies 38 were randomly selected and a of 10 subjects was recruited from each agency. Subjects were interviewed, underwent a comprehensive physical examination and had blood samples taken. Gold standard laboratory tests were conducted to detect HIV, hepatitis B, C, and D infections. To assess risk factors associated with current hepatitis B infections or being a carrier (HBsAg) and lifetime exposure to hepatitis B infection (anti-HBc), simple and multiple logistic regression analyses were performed.

RESULTS

The prevalence of diseases were: HIV 0%, hepatitis C <1%, hepatitis B surface antigen 5.9%, antibody to hepatitis B core antigen 48.1% (with 5 of the 23 HBsAg positive cases testing positive for HBeAg and 18 for anti-HBe), and hepatitis D 0%. Having ever received a therapeutic injection and having had relations with a commercial sex worker (CSW) in the past year were both significantly associated with lifetime exposure to hepatitis B (anti-HBc); having received a therapeutic injection in the past year was associated with being either currently infected with hepatitis B or a carrier (HBsAg).

CONCLUSIONS

The results of the study illustrate the importance of educating health care practitioners about the dangers of unsterile injections, and of educating men in the trucking industry as well as their partners (CSW in particular) about the importance of condom use, especially in high-risk sexual contacts.

Antibiotic- and metal-resistant strains of Vibrio parahaemolyticus isolated from shrimps

Enteropathogenic strains of Vibrio parahaemolyticus were isolated from shrimps, Penaeus monodon collected from the region of the Deltaic Sundarbans (West Bengal, India). About 63% of the isolated strains were resistant to ampicillin, cephalexin, and kanamycin. However, all these strains were sensitive to nitrofurantoin, nalidixic acid, tetracycline, and norfloxacin. The isolated strains were resistant to Ni2+] (75%), Cu2+ (87%), and Co2+ (37%), but all the strains were resistant against Cd2+, Zn2+, and Pb2+ at 10 mM concentration.

Processing by endoplasmic reticulum mannosidases partitions a secretion-impaired glycoprotein into distinct disposal pathways

In the early secretory pathway, a distinct set of processing enzymes and family of lectins facilitate the folding and quality control of newly synthesized glycoproteins. In this regard, we recently identified a mechanism in which processing by endoplasmic reticulum mannosidase I, which attenuates the removal of glucose from asparagine-linked oligosaccharides, sorts terminally misfolded alpha(1)-antitrypsin for proteasome-mediated degradation in response to its abrogated physical dissociation from calnexin (Liu, Y., Choudhury, P., Cabral, C., and Sifers, R. N. (1999) J. Biol. Chem. 274, 5861-5867). In the present study, we examined the quality control of genetic variant PI Z, which undergoes inappropriate polymerization following biosynthesis. Here we show that in stably transfected hepatoma cells the additional processing of asparagine-linked oligosaccharides by endoplasmic reticulum mannosidase II partitions variant PI Z away from the conventional disposal mechanism in response to an arrested posttranslational interaction with calnexin. Intracellular disposal is accomplished by a nonproteasomal system that functions independently of cytosolic components but is sensitive to tyrosine phosphatase inhibition. The functional role of ER mannosidase II in glycoprotein quality control is discussed.

Do Indian researchers read Indian research? A reappraisal, four years later

A previous study found that many papers in the Indian Journal of Psychiatry (UP) had failed to reference relevant papers previously published in the same journal. The present study examined whether any change in referencing patterns had occurred The database comprised 182 eligible articles published in the UP during 1993-1996. In general, few articles cited previous UP papers (median citations, 0-1); however, few articles omitted to cite previous (relevant) UP research (median omissions, 0-1). The average number of articles cited: omitted was 2:1. Original articles cited as well as omitted more UP references than brief communications. The larger the number of total references cited, the larger was the number of UP references both cited and omitted. No significant changes in referencing patterns was evident across the years. Indexing of articles, an important method of identifying relevant, previously published research was grossly adequate in 89% of articles; the average article received 2 index entries. While UP papers appear to be receiving greater attention, it is suggested that room for improvement remains.

An open trial of zuclopenthixol in management of acute psychoses : a multicentered study

In an open trial, patients with ICD-10 diagnosis of acute functional psychoses were administered injection Zuclopenthixol acetate (Acuphase) in the initial phase. Patients were rated with CGI, BPRS -24 item and UKU side effect rating scale at baseJine, 24 hours and 72 hours. Of the 120 patients recruited, 119 finished this part of the trial. The most common side effect was sedation, which was preferable as most of the patients were in the acute state. The issues concerning less dosing efficacy and the rapid onset of antipsychotic activity are discussed.Patients who had been administered zuclopenthixol acetate in the acute phase were maintained with injection zuclopenthixol decanoate (depot) starting at 72 hours over the baseline. Patients were assessed at 72 hours, one week, 2 weeks, 3 vseeks, 4 weeks and 8 weeks using the same instruments. The issues concerning the dosage and therapeutic efficacy are discussed.

HIV/AIDS in Bangladesh: an assessment of biomedical risk factors for transmission

Behavioural risk factors for HIV/AIDS in Bangladesh were reviewed in a preceding article in this journal. Omitted from that review was a discussion of potential biomedical risk factors including: (i) an unregulated blood supply system in which blood used in transfusions is not screened for HIV and is donated primarily by professional donors: (ii) unsterile injections in non-formal and formal health-care settings; and (iii) a high prevalence in high-risk groups of other sexually transmitted diseases (STDs) which may function as co-factors for HIV transmission, particularly if chronically untreated. Studies elsewhere in the world suggest that the unregulated blood supply system, in particular, poses a serious danger in terms of the spread of the HIV epidemic. While certain socio-cultural factors may be contributing to low levels of HIV in Bangladesh, the prevalence of biomedical and behavioural risk factors suggest the importance of implementing targeted cost-effective interventions now.