Alcohol and drug use severity are independently associated with antiretroviral adherence in the current treatment era.

Substance use in people with HIV (PWH) negatively impacts antiretroviral therapy (ART) adherence. However, less is known about this in the current treatment era and the impact of specific substances or severity of substance use. We examined the associations of alcohol, marijuana, and illicit drug use (methamphetamine/crystal, cocaine/crack, illicit opioids/heroin) and their severity of use with adherence using multivariable linear regression in adult PWH in care between 2016 and 2020 at 8 sites across the US. PWH completed assessments of alcohol use severity (AUDIT-C), drug use severity (modified ASSIST), and ART adherence (visual analogue scale). Among 9400 PWH, 16% reported current hazardous alcohol use, 31% current marijuana use, and 15% current use of ≥1 illicit drugs. In multivariable analysis, current methamphetamine/crystal use, particularly common among men who had sex with men, was associated with 10.1% lower mean ART adherence (p < 0.001) and 2.6% lower adherence per 5-point higher severity of use (ASSIST score) (p < 0.001). Current and more severe use of alcohol, marijuana, and other illicit drugs were also associated with lower adherence in a dose-dependent manner. In the current HIV treatment era, individualized substance use treatment, especially for methamphetamine/crystal, and ART adherence should be prioritized.

Biodegradable cationic nanogels with tunable size, swelling and pKa for drug delivery.

Cationic polymers have garnered significant interest for their utility in intracellular drug delivery and gene therapy. However, due to their associated toxicities, novel synthesis approaches must be explored to develop materials that are biocompatible. The novel library of nanoparticles synthesized in this study exhibit tunable hydrodynamic diameters, composition and pH-responsive properties as a function of synthesis parameters. In addition, differences in the responsiveness of these nanoparticles under different pH conditions affords greater control over intracellular drug release.

Differential prognostic accuracy of right ventricular dysfunction, the Seattle heart failure model and the MAGGIC score in patients with severe mitral regurgitation undergoing the MitraClip® procedure.

BACKGROUND: MitraClip ® (MC) is an established procedure for severe mitral regurgitation (MR) in patients deemed unsuitable for surgery.Right ventricular dysfunction (RVD) is associated with a higher mortality risk. The prognostic accuracy of heart failure risk scores like the Seattle heart failure model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score in pts undergoing MC with or without RVD has not been investigated so far. METHODS: SHFM and MAGGIC score were calculated retrospectively. RVD was determined as tricuspid annular plane systolic excursion (TAPSE) ≤15 mm. Area under receiver operating curves (AUROC) of SHFM and MAGGIC were performed for one-year all-cause mortality after MC. RESULTS: N = 103 pts with MR III° (73 ± 11 years, LVEF 37 ± 17%) underwent MC with a reduction of at least I° MR. One-year mortality was 28.2%.In Kaplan-Meier analysis, one- year mortality was significantly higher in RVD-pts (34.8% vs 2.8%, p = 0.009).Area under the Receiver Operating Characteristic (AUROC) for SHFM and MAGGIC were comparable for both scores (SHFM: 0.704, MAGGIC: 0.692). In pts without RVD, SHFM displayed a higher AUROC and therefore better diagnostic accuracy (SHFM: 0.776; MAGGIC: 0.551, p < 0.05). In pts with RVD, MAGGIC and SHFM displayed comparable AUROCs. CONCLUSION: RVD is an important prognostic marker in pts undergoing MC. SHFM and MAGGIC displayed adequate over-all prognostic power in these pts. Accuracy differed in pts with and without RVD, indicating higher predictive power of the SHFM score in pts without RVD.

A comparison of digital chest radiography and Xpert® MTB/RIF in active case finding for tuberculosis.

OBJECTIVE: To compare two community screening tests for TB: sputum examination using Xpert® MTB/RIF and chest radiography (CXR).METHOD: Men aged ≥15 years and women aged >45 years living in 96 sub-communes in Ca Mau, Viet Nam, were invited to provide a single sputum specimen that was tested using Xpert. Participants were also invited to attend a nearby location for digital radiography. Participants whose sputum was Xpert MTB-positive or whose CXR was reported as 'consistent with TB´ were requested to provide two further sputum specimens for culture. The sensitivities of the two tests for detecting TB (defined as sputum culture-positive for Mycobacterium tuberculosis) were compared.RESULTS: There were 72 985 eligible participants, of whom 57 597 (78.9%) participated in Xpert screening, 12 752 (17.5%) had CXR and 11 235 (15.4%) had both tests. We estimated that there were 59 cases of TB, of whom 20 were Xpert MTB-positive (programmatic sensitivity 34.0%) and 47 had CXR reported as 'consistent with TB´ (sensitivity 80.0%, P < 0.0001).CONCLUSION: In community-wide screening for TB, CXR is more sensitive than a single spontaneously expectorated sputum sample tested using Xpert, but it has a substantially lower participation rate.

A Cytokinin (Isopentenyl-Adenosyl-Mononucleotide) Linked to Ecdysone in Newly Laid Eggs of Locusta migratoria.

Newly laid eggs of the insect Locusta migratoria contain high concentrations (50 nanomoles per gram) of an ecdysone conjugate of maternal origin; 3 milligrams of this conjugate were isolated by conventional techniques, and the structure was established by mass spectrometry and (1)H, (13)C, and (31)P nuclear magnetic resonance as the 22-N(6)-(isopentenyl)-adenosine monophosphoric ester of ecdysone.

Identification of novel and conserved microRNA and their expression in the gray mouse lemur, Microcebus murinus, a primate capable of daily torpor.

MicroRNA (miRNA) are endogenous small noncoding RNA gene products, on average 22 nt long, that play important regulatory roles in mediating gene expression by binding to and targeting mRNAs for degradation or translational repression. In this paper we identify both novel and conserved miRNA sequences present in the genome of the gray mouse lemur, Microcebus marinus. In total, 122 conserved and 44 novel miRNA were identified with high confidence from the lemur genome (Mmur_2.0) and were used for expression analysis. All conserved and novel miRNA were subjected to relative quantification by RT-qPCR in liver samples from control and torpid lemurs. A total of 26 miRNA (16 conserved and 10 novel) showed increased levels during primate torpor, whereas 31 (30 conserved and 1 novel) decreased. Additional in silico mapping of the predicted mRNA targets of torpor-responsive mature miRNA suggested that miRNA that increased during torpor were collectively involved in cell development and survival pathways, while miRNA that decreased were enriched in targeting immune function. Overall, the study suggests new regulatory mechanisms of primate torpor via miRNA action.

The role of macroscopic sputum quality assessments to optimise sputum testing for tuberculosis.

SETTING: Community-wide active case finding for tuberculosis (TB) using Xpert® MTB/RIF as the primary screening tool, Ca Mau Province, Viet Nam. OBJECTIVES: To determine whether macroscopic sputum quality characteristics (sputum colour and volume) can be used to predict Xpert MTB-negative sputum and hence exclude sputum samples from testing. DESIGN: Field staff conducted household visits to approximately 51,200 adults in 58 villages randomly selected from throughout the province. Sputum samples from all screened participants who were able to produce ⩾1 ml sputum underwent macroscopic sputum assessment and were tested with Xpert. RESULTS: Of the 21,624 sputum samples tested, 159 (0.74%) were Xpert MTB-positive; 93% of the samples were 1-2 ml and nearly all were mucoid (93%) or mucopurulent (5.7%). One salivary sample was Xpert MTB-positive (2.0% of all salivary samples). The lowest positive predictive value for any sputum volume or colour characteristic was 0.66%. This was not substantially different from the overall prevalence of positive sputum Xpert MTB (0.74%). CONCLUSION: Sputum colour and volume cannot be used to predict the presence or absence of M. tuberculosis in sputum detected using Xpert. These sputum quality parameters cannot therefore be used to exclude sputum samples from testing for TB.

Isolation and purification of dicyclohexylcarbodiimide-reactive proteolipid from Bacillus subtilis membrane.

The membrane-bound ATPase activity of Bacillus subtilis was inhibited by dicyclohexylcarbodiimide (DCCD). The DCCD-reactive proteolipid of B. subtilis was extracted, from labelled or untreated membranes containing F1 or depleted of F1, with neutral or acidic chloroform/methanol. Purification of the [14C]DCCD-binding proteolipid was attempted by column chromatography on methylated Sephadex G-50 and on DEAE-cellulose. The maximal amount of DCCD which could be bound to the purified proteolipid was found to exceed the amount bound by the purified proteolipid extracted from membranes labelled with the lowest [14C]DCCD concentration required for maximal inhibition of the membrane-bound ATPase activity. The radioactive protein peaks eluted by gel filtration and ion-exchange chromatography were analysed by urea-SDS polyacrylamide slab gel electrophoresis and autoradiography. Radioactivity was incorporated into two components of Mr 18 000 and 6000 when proteolipid was purified by methylated Sephadex. The 6000 polypeptide was always present, whatever the extraction and purification procedures. However, the 18 000 polypeptide was present in largest quantity only when proteolipid was extracted from membranes containing F1 and purified by methylated Sephadex. When proteolipid was purified on DEAE-cellulose this [14C]DCCD binding component of Mr 18 000 was absent.

Selectivity of lipid-protein interaction with myelin proteolipids PLP and DM-20. A fluorescence anisotropy study.

The two main myelin proteolipids, PLP (30 kDa) and DM-20 (25 kDa), differ by an internal deletion in DM-20. The deleted fragment, of 35 amino acids (116-150), corresponds to the major hydrophilic domain of PLP. Fluorescence anisotropy experiments using diphenylhexatriene as a fluorescent probe were performed to detect the phase separation induced by these two proteolipids in multilamellar vesicles of binary composition. We found that in vesicles composed of 30% L-alpha-PS and 70% DPPC, the PLP boundary layer contained about 18 motionally restricted phospholipids, almost exclusively L-alpha-PS. On the contrary, the DM-20 boundary layer contained only 14 to 15 phospholipids, with a composition no different from that of the bulk vesicle. In mixtures of DMPG and DPPC, the selectivity of PLP for the acidic phospholipid DMPG was maintained, but was lower than that observed for L-alpha-PS. We assume that this selectivity of PLP stems mainly from electrostatic interactions between the charged residues of the 116-150 fragment, deleted in DM-20, and the acidic phospholipids. These results suggest that fragment 116-150 may play a specific role in the interaction of PLP with the lipid bilayer of the myelin membrane.

Solution structure of PMP-C: a new fold in the group of small serine proteinase inhibitors.

The solution structure and the disulfide pairings of a 36-residue proteinase inhibitor isolated from the insect Locusta migratoria have been determined using NMR spectroscopy and simulated annealing calculations. The peptide, termed PMP-C, was previously shown to inhibit bovine alpha-chymotrypsin as well as human leukocyte elastase, and was also found to block high-voltage-activated Ca2+ currents in rat sensory neurones. PMP-C has a prolate ellipsoid shape and adopts a tertiary fold hitherto unobserved in the large group of small "canonical" proteinase inhibitors. The over-all fold consists mainly of three strands arranged in a right-handed twisted, antiparallel, beta-sheet that demarcates a cavity, together with a linear amino-terminal segment oriented almost perpendicular to the three strands of the beta-sheet. Inside the cavity a phenyl ring constitutes the centre of a hydrophobic core. The proteinase binding loop is located in the carboxy-terminal part of the molecule, between two cysteine residues involved in disulfide bridges. Its conformation resembles that found in other small canonical proteinase inhibitors. A comparison of PMP-C structure with the recently published solution structure of the related peptide PMP-D2 shows that the most significant differences are complementary changes involved in the stabilization of similar folds. This comparison led us to review the structure of PMP-D2 and to identify two salt bridges in PMP-D2.

Effect of 7 beta-hydroxycholesterol on growth and membrane composition of Mycoplasma capricolum.

7 beta-OH cholesterol in a cholesterol rich growth medium (5-10 micrograms/ml) extended the lag period and slowed down the growth rate of Mycoplasma capricolum cells. In a cholesterol poor medium (0.5 micrograms/ml) inadequate to support growth, 7 beta-OH cholesterol exerts a synergistic effect on growth. The 7 beta-OH cholesterol was incorporated unchanged from the growth medium and could be recovered exclusively in the membrane fraction. The incorporation of the 7 beta-OH cholesterol has no effect on the total phospholipid content but the DPG to PG ratio was markedly decreased. Exchange studies with lipid vesicles revealed that whereas most of the cholesterol underwent exchange, only about 20% of the 7 beta-OH cholesterol was exchanged.

Isolation and amino acid sequence of a novel 6.8-kDa mitochondrial proteolipid from beef heart. Use of FAB-MS for molecular mass determination.

We have isolated a 6.8 kDa proteolipid from an acidic chloroform/methanol extract of bovine cardiac muscle. The molecular mass of the polypeptide was measured by fast atom bombardment-mass spectrometry (FAB-MS) (m/z6834.1). Its amino acid sequence was partly determined by direct sequencing and completed by characterization of cyanogen bromide and tryptic fragments (sequencing, FAB-MS and amino acid analysis). The polypeptide consists of 60 amino acid residues. Polyclonal antibodies raised in rabbit allowed its localization by electroimmunoblotting in mitochondria.

Electrophysiological activity of the C-peptide of the Locusta insulin-related peptide. Effect on the membrane conductance of Locusta neurones in vitro.

The C-peptide of Locusta insulin-related peptide, which is a 50 residue peptide originally isolated from the corpora cardiaca of the insect Locusta migratoria and to which we refer as 5-kDa peptide, has been synthesised chemically by the solid-phase method, using a BOC strategy. Since this peptide contains in its sequence a potential monobasic cleavage site, we also synthesised its 1-38 residue-related fragment, named 4-kDa peptide, although we have no hints of its natural occurrence in the corpora cardiaca. Electrophysiological studies have shown that both the 5-kDa and 4-kDa peptides depolarise the membrane and increase the membrane conductance of neurones freshly isolated from the thoracic ganglia of Locusta. Under voltage-clamp conditions, the current underlying these effects was inwardly directed and could be resolved into 2 components. One component, I(5-kDa)1, activated at potentials more hyperpolarised than -50 mV, peaked at about -75 mV and was blocked by the potassium channel blockers cesium and rubidium. The second component, I(5-kDa)2 was activated at potentials more depolarised than -50 mV, increased with depolarisation and was not blocked by cesium and rubidium. The effects of the 5-kDa and 4-kDa peptides on the membrane potential and membrane conductance of Locusta neurones suggest that these peptides may have a physiological role in the central nervous system of insects.

Neurotrophic effect of naturally occurring long-chain fatty alcohols on cultured CNS neurons.

A long-chain fatty alcohol,n-hexacosanol, that we have isolated from the Far-Eastern traditional medicinal plant, Hygrophila erecta, Hochr., is shown to promote the maturation of central neurons. Added at 500 nM to fetal rat brain neurons in culture, it increased both neurite outgrowth by a factor of 4-6 and the number of collaterals, especially in multipolar neurons. The biochemical differentiation of cultured neurons was also strikingly enhanced by this compound: it increased the protein content and almost doubled the activities of two neuron-specific enzymes, phosphate-activated glutaminase and neuron-specific enolase, by 92 and 78%, respectively. Extensive studies with several synthetic long-chain fatty alcohols showed that the neurotrophic activity was maximal for n-hexacosanol. It is suggested that some long-chain fatty alcohols with an appropriate length of hydrocarbon chain might play an important role in central neuron development.

A specific immunological probe for the major myelin proteolipid. Confirmation of a deletion in DM-20.

Major myelin proteolipid (MMPL, also called PLP) and DM-20 are the two major intrinsic membrane proteins of CNS myelin. A specific immunological probe was obtained for MMPL by raising antibodies against the synthetic tridecapeptide 117-129 of MMPL. Antibodies against this peptide reacted with the MMPL but did not cross react with DM-20, while both proteolipids had been shown previously to be recognized by antibodies directed against the C-terminal hexapeptide of MMPL. This is in accordance with previous findings showing that DM-20 differs only from MMPL by a deletion of residues 100-140 (+/- few units). Furthermore, this site-specific immunological probe also recognizes MMPL in its native form in oligodendrocytes in primary glial cell cultures.

Apoptosis at the interface of immunosuppressive and anticancer activities: the examples of two classes of chemical inducers, oxysterols and alkylating agents.

Recent progresses in the understanding of molecular and biochemical pathways involved in apoptotic cell death offer novel perspectives for therapeutic interventions, in particular in immunosuppressive and anti-cancer therapies. In this review, we examine some chemical, biological, and mechanistic aspects of two classes of apoptosis chemical inducers: oxysterols and alkylating agents. Oxysterols represent a vast family of oxygenated derivatives of sterols. Found in both animal and vegetal kingdoms, they can be considered as ultimate products of an oxidative stress, and are chemically inert. Some of them (7beta-hydroxycholesterol, 25-hydroxycholesterol and 7, 25-dihydroxycholesterol) are cytotoxic at micromolar concentrations towards normal and tumor cells in culture, particularly lymphocytes, and reduce the growth of murine transplanted tumors. Thus, possible applications of oxysterols in medicine as immunosuppressants or as anticancer agents may be considered. Alkylating agents, on the other hand, have been widely used in cancer chemotherapy for decades. There toxicity results from their high chemical reactivity, causing lesions to macromolecules through covalent linkage. Some representative members of this class, mainly bifunctional derivatives which possess dichloroethyl groups, such as Chlormethine, Cyclophosphamide and Chlorabucil, express a pronounced cytotoxicity against lymphoid cells, and have therefore potent immunosuppressive properties. Because they triggers apoptosis via both common and distinct mechanisms, oxysterols and alkylating agents provide unique tools for exploring the initiation of this phenomenon in lymphoid cells, and may help design novel pharmacological approaches based on apoptotic modulation of these cells.

Oxysterols: biological activities and physicochemical studies.

To improve the understanding of the various biological activities of oxysterols (oxygenated derivatives of cholesterol), studies of their physicochemical properties have been undertaken. Oxysterols modify membrane dynamic properties which consequently trigger several biological effects. Despite the presence of at least one oxygenated group in addition to the C3 beta-hydroxyl, oxysterols insert perfectly into the lipidic bilayer of the membrane inducing a condensing effect similar to, but less potent than, that of cholesterol. In biological membranes oxysterols probably interact with membrane components as they are not easily exchanged after their incorporation into the cell membrane. These lipid-protein interactions are probably crucial for the expression of the biological activities of the oxysterols.

Membrane-related oxysterol function: preliminary results on the modification of protein kinase C activity and substrate phosphorylation by 7 beta,25-dihydroxycholesterol.

Oxysterols exhibit a wide variety of biological activities, including potent immunosuppressive effects. 7 beta,25-Dihydroxycholesterol (7,25-OHC), a synthetic oxysterol, has been shown to strongly inhibit the lymphocyte response to different stimuli. This compound has been chosen as a model compound to investigate the mechanisms underlying the immunosuppressive effects of oxysterols. As protein kinase C (PKC) constitutes a key enzyme in the pathways leading to cell activation, we have studied the effect of 7,25-OHC on PKC activity in the cytosolic and particulate fractions of spleen cells. Lymphocytes treated with 7,25-OHC showed a decrease of the relative PKC activity in the particulate fractions compared to control cells. These results are confirmed by the observation that 7,25-OHC also reduces the phosphorylation of the endogenous PKC substrates. Thus oxysterols interfere with two membrane related phenomena, ie the modification of membrane PKC activity and the inhibition of the phosphorylation of the substrates of PKC located in the membrane. Previous results obtained by fluorescence polarisation revealed a modification of the membrane fluidity after oxysterol treatment. Furthermore, it has been demonstrated that oxysterols are incorporated into cell membranes. The alteration of the cell membrane could impair the signal transduction and may explain the immunosuppressive activity of oxysterol. Thus, along with other biological effects previously reported, oxysterols decrease membrane associated PKC activity in immune cells.

Purification and characterization of minor brain proteolipids: use of fast atom bombardment-mass spectrometry for peptide sequencing.

A combination of lipophilic gel permeation chromatography and ion-exchange chromatography in organic solvents was used to purify low molecular weight proteolipids from bovine brain. Cleavage peptides were purified by HPLC and studied mainly by the fast atom bombardment--mass spectrometry technique. A proteolipid of Mr 14 000 contains several peptides from the first 113 amino acids of the major myelin proteolipid (MMPL) plus an extra unknown blocked N-terminal peptide. A proteolipid of Mr 16 000 contains smaller peptides belonging to a C-terminal fragment of MMPL of about 160 residues. These two proteolipids do not seem to be artifacts from MMPL.

Monophosphoric acid diesters of 7 beta-hydroxycholesterol and of pyrimidine nucleosides as potential antitumor agents: synthesis and preliminary evaluation of antitumor activity.

7 beta-Hydroxycholesterol, which has been shown to be selectively cytotoxic toward tumor cells cultured in vitro, was converted into the corresponding water-soluble phosphoric acid ester and linked to a pyrimidine nucleoside such as 5-fluoro-2'-deoxyuridine or 2'-deoxyuridine. 2-Chlorophenyl phosphorodichloridate (3), without activation, was used directly to phosphorylate the protected oxygenated sterol. The intermediate phosphorylated the 5'-OH group of nucleoside selectively, leading to compounds 1a and 1b after deprotection. These compounds were screened for their antiproliferative activity toward EL-4 murine leukemia cells in vitro and for their antitumor activity against the mice bearing Krebs II ascitic carcinoma in vivo.