Incidence of AIDS-Defining Opportunistic Infections and Mortality during Antiretroviral Therapy in a Cohort of Adult HIV-Infected Individuals in Hanoi, 2007-2014

Background

Although the prognosis for HIV-infected individuals has improved after antiretroviral therapy (ART) scale-up, limited data exist on the incidence of AIDS-defining opportunistic infections (ADIs) and mortality during ART in resource-limited settings.

Methods

HIV-infected adults in two large hospitals in urban Hanoi were enrolled to the prospective cohort, from October 2007 through December 2013. Those who started ART less than one year before enrollment were assigned to the survival analysis. Data on ART history and ADIs were collected retrospectively at enrollment and followed-up prospectively until April 2014.

Results

Of 2,070 cohort participants, 1,197 were eligible for analysis and provided 3,446 person-years (PYs) of being on ART. Overall, 161 ADIs episodes were noted at a median of 3.20 months after ART initiation (range 0.03–75.8) with an incidence 46.7/1,000 PYs (95% confidence interval [CI] 39.8–54.5). The most common ADI was tuberculosis with an incidence of 29.9/1,000 PYs. Mortality after ART initiation was 8.68/1,000 PYs and 45% (19/45) died of AIDS-related illnesses. Age over 50 years at ART initiation was significantly associated with shorter survival after controlling for baseline CD4 count, but neither having injection drug use (IDU) history nor previous ADIs were associated with poor survival. Semi-competing risks analysis in 951 patients without ADIs history prior to ART showed those who developed ADIs after starting ART were at higher risk of death in the first six months than after six months.

Conclusion

ADIs were not rare in spite of being on effective ART. Age over 50 years, but not IDU history, was associated with shorter survival in the cohort. This study provides in-depth data on the prognosis of patients on ART in Vietnam during the first decade of ART scale-up.     

Development of an HPLC Method with an ODS Column to Determine Low Levels of Aspartame Diastereomers in Aspartame

α-L-Aspartyl-D-phenylalanine methyl ester (L, D-APM) and α-D-aspartyl-L-phenylalanine methyl ester (D, L-APM) are diastereomers of aspartame (N-L-α-Aspartyl-L-phenylalanine-1-methyl ester, L, L-APM). The Joint FAO/WHO Expert Committee on Food Additives has set 0.04 wt% as the maximum permitted level of the sum of L, D-APM and D, L-APM in commercially available L, L-APM. In this study, we developed and validated a simple high-performance liquid chromatography (HPLC) method using an ODS column to determine L, D-APM and D, L-APM in L, L-APM. The limits of detection and quantification, respectively, of L, D-APM and D, L-APM were found to be 0.0012 wt% and 0.004 wt%. This method gave excellent accuracy, repeatability, and reproducibility in a recovery test performed on five different days. Moreover, the method was successfully applied to the determination of these diastereomers in commercial L, L-APM samples. Thus, the developed method is a simple, useful, and practical tool for determining L, D-APM and D, L-APM levels in L, L-APM.     

Ant-Repelling Pollinators of the Myrmecophytic <Emphasis Type="Italic">Macaranga winkleri</Emphasis> (Euphorbiaceae)

Many plants have mutualistic relationships with ants, whereby plants provide food and/or nesting sites for the symbiotic ants, and in turn the ants protect the host plants by excluding herbivores. While the ants are useful as guards, they may negatively affect host reproduction by excluding pollinators. Here we studied this potential conflict in the myrmecophytic Macaranga winkleri pollinated by the thrips Dolichothrips fialae. Behavioural responses of ant guards to pollinator thrips and their chemicals, and related chemical analyses, provide evidence that thrips deter ant-guards by secreting droplets containing ant-repelling n-decanoic acid from their anuses. This is the first report of insect pollinators repelling their host’s symbiotic guard ants to perform pollination. This is a novel strategy by which a plant host avoids interference with pollination by ant-guards in an ant–plant mutualism. The acquisition of a pollination system that is resistant to ant attacks may have facilitated the evolution of myrmecophytes in the genus Macaranga.     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

Global DNA methylation (LINE-1) associated with exposure to arsenic-contaminated environment and with type of arsenical skin lesions in Thailand

The effects of chronic arsenic exposure mode on DNA methylation and skin lesion type are unclear. These relationships were investigated in an arsenic-contaminated area of southern Thailand. Cases with arsenical skin lesions (n = 131) and lesion-free controls (n = 163) were selected from an arsenic-contaminated sub-district, as well as 105 controls from a non-contaminated area. Type and severity of skin lesions and salivary global DNA methylation (LINE-1) were determined. Arsenic exposure was characterized as occupational, domestic and current (toe-nail arsenic). Associations were explored using logistic regression. Cases and controls had lower LINE-1 methylation and higher toenail arsenic than external controls (74.65% and 74.61% vs 76.05%, p < 0.001 for each). Cases were more likely to have been exposed domestically (OR_total 1.76, 95% ci 1.00, 3.11; and 2.22, 95% ci 1.22, 4.03; P_trend = 0.005 for exposure <36 and ≥36 years). More severe spotty hyperpigmentation was related to higher LINE-1 methylation (P_trend=0.006). LINE-1 methylation was positively associated with toenail arsenic only among non-symptomatic exposed subjects (OR 1.31, 95% ci 1.06, 1.64; p = 0.014). Exposure to an arsenic-contaminated environment results in global DNA hypomethylation. However, among symptomatic subjects, increased global DNA methylation was associated with increased severity of spotty hyperpigmentation.     

Gadd45a, the gene induced by the mood stabilizer valproic acid, regulates neurite outgrowth through JNK and the substrate paxillin in N1E-115 neuroblastoma cells

Valproic acid (VPA), a mood stabilizer and anticonvulsant, has a variety of neurotrophic functions; however, less is known about how VPA regulates neurite outgrowth. Here, using N1E-115 neuroblastoma cells as the model, we show that VPA upregulates Gadd45a to trigger activation of the downstream JNK cascade controlling neurite outgrowth. VPA induces the phosphorylation of c-Jun N-terminal kinase (JNK) and the substrate paxillin, while VPA induction of neurite outgrowth is inhibited by JNK inhibitors (SP600125 and the small JNK-binding peptide) or a paxillin construct harboring a Ser 178-to-Ala mutation at the JNK phosphorylation. Transfection of Gadd45a, acting through the effector MEKK4, leads to the phosphorylation of the JNK cascade. Conversely, knockdown of Gadd45a with siRNA reduces the effect of VPA. Taken together, these results suggest that upregulation of Gadd45a explains one of the mechanisms whereby VPA induces the neurotrophic effect, providing a new role of Gadd45a in neurite outgrowth.     

Direct neurite-osteoblastic cell communication, as demonstrated by use of an in vitro co-culture system

Using an in vitro co-culture approach comprising cultured murine superior cervical ganglia and MC3T3-E1 osteoblast-like cells, we found that the addition of scorpion venom (SV) elicited neurite activation via intracellular Ca2+ mobilization and, after a lag period, osteoblastic Ca2+ mobilization. SV did not have any direct effect on the osteoblastic cells in the absence of neurites. The addition of an alpha1-adrenergic receptor (AR) antagonist, prazosin, dose-dependently prevented the osteoblastic activation that resulted as a consequence of neural activation by SV. These results demonstrate that osteoblastic activation occurred as a direct response to neuronal activation, which activation was mediated by alpha1-ARs in the osteoblastic cells.     

Excitability of oxytocin neurons in paraventricular nucleus is regulated by voltage-gated potassium channels Kv4.2 and Kv4.3

Oxytocin is produced by neurons in the paraventricular nucleus (PVN) and the supraoptic nucleus in the hypothalamus. Various ion channels are considered to regulate the excitability of oxytocin neurons and its secretion. A-type currents of voltage-gated potassium channels (Kv channels), generated by Kv4.2/4.3 channels, are known to be involved in the regulation of neuron excitability. However, it is unclear whether the Kv4.2/4.3 channels participate in the regulation of excitability in PVN oxytocin neurons. Here, we investigated the contribution of the Kv4.2/4.3 channels to PVN oxytocin neuron excitability. By using transgenic rat brain slices with the oxytocin-monomeric red fluorescent protein 1 fusion transgene, we examined the excitability of oxytocin neurons by electrophysiological technique. In some oxytocin neurons, the application of Kv4.2/4.3 channel blocker increased firing frequency and membrane potential with extended action potential half-width. Our present study indicates the contribution of Kv4.2/4.3 channels to PVN oxytocin neuron excitability regulation.

Abbreviation: PVN, paraventricular nucleus; Oxt-mRFP1, Oxt-monometric red fluorescent protein 1; PaTx-1, Phrixotoxin-1; TEA, Tetraethylammonium Chloride; TTX, tetrodotoxin; aCSF, artificial cerebrospinal fluid;PBS, phosphate buffered saline 3v, third ventricle.     

Nuclear shuttling of mitogen-activated protein (MAP) kinase (extracellular signal-regulated kinase (ERK) 2) was dynamically controlled by MAP/ERK kinase after antigen stimulation in RBL-2H3 cells

The mitogen-activated protein kinase (MAPK) cascade consists of the MAPK (extracellular signal-regulated kinase 2; ERK2) and its activator, MAPK kinase (MAP/ERK kinase; MEK). However, the mechanisms for activation of ERK2 have not been defined yet in cells. Here, we used fluorescent protein-tagged ERK2 and MEK to examine the localization of ERK2 and MEK in living rat basophilic leukemia (RBL-2H3) cells. ERK2 was mainly in the cytoplasm in resting cells but translocated into the nucleus after the ligation of IgE receptors. The import of ERK2 reached the maximum at 6--7 min, and then the imported ERK2 was exported from the nucleus. MEK mainly resided in the cytoplasm, and no significant MEK translocation was detected statically after ligation of IgE receptors. However, analysis of the dynamics of ERK2 and MEK suggested that both of them rapidly shuttle between the cytoplasm and the nucleus and that MEK regulates the nuclear shuttling of ERK2, whereas MEK remains mainly in the cytoplasm. In addition, the data suggested that the sustained calcium increase was required for the optimal translocation of ERK2 into the nucleus in RBL-2H3 cells. These results gave a new insight of the dynamics of ERK2 and MEK in the nuclear shuttling of RBL-2H3 cells after the ligation of IgE receptors.     

Approach for functional analysis of glycan using RNA interference

The elucidation of the biological role of glycan is one of the most important issues to be resolved following the genome project. RNA interference is becoming an efficient reverse genetic tool for studying gene function in model organisms, including C.elegans and Drosophila melanogaster. Our molecular evolutionary study has shown that a prototype of glycosyltransferases, which synthesize a variety of glycan structures in the Golgi apparatus, was conserved between mammals and Drosophila. For analyses of the basic physiological functions of glycans, we established the Drosophila inducible RNAi knockdown system and applied it to one glycosyltransferase and one transporter, proteoglycan UDP-galactose: beta-xylose beta1,4galactosyltransferase I and the PAPS-transporter, respectively. If on the silencing of each gene induced ubiquitously under the control of a cytoplasmic actin promoter, the RNAi knockdown fly died, then the protein was indispensable for life. The expression of the target gene was disrupted specifically and the degree of interference was well correlated with the phenotype. The inducible RNAi knockdown fly obtained using the GAL4-UAS system will pave the way for the functional analysis of glycans.