Depression and dietary intake in a cohort of HIV-positive clients in Sydney.

This cross-sectional study aimed to compare dietary intake in people living with HIV (PLHIV) experiencing symptoms of depression with those not reporting depression. The Centre for Epidemiologic Studies Depression Scale (CES-D10) was used to classify the risk of depression. Dietary nutrient intake was determined using the diet history and food frequency questionnaire. Depressed (n = 21) compared with non-depressed (n = 37) subjects had significantly lower mean intake of fibre (16.1 versus 25.4 g/day), vitamin A (801.5 versus 1524.8 mg/day), magnesium (299.8 versus 380.0 mg/day) and folate (264.8 versus 402.9 µg/day). The proportion of subjects achieving the recommended intake of these nutrients, with the exception of folate was also found to be lower in the depressed group compared with non-depressed group. The study found that depressive symptomatology in PLHIV was associated with poorer dietary nutrient intake. A multidisciplinary model of care that includes a nutrition assessment is recommended for the management of PLHIV with depression to reduce the risk of associated nutritional problems.

Factors associated with unprotected anal intercourse between HIV-positive men and regular male partners in a Sydney cohort.

Blood plasma HIV-RNA load (BPVL) is the strongest predictor of HIV-1 transmission during sex. Unprotected anal intercourse (UAI) is the highest risk activity for transmission among men who have sex with men (MSM). Awareness of BPVL may influence rates of UAI. We assessed whether optimism towards antiretroviral therapy (ART) and/or biomedical factors influenced sexual activities with regular partners. Questionnaires were administered to 109 HIV-positive MSM participating in a cross-sectional study of BPVL and seminal viral load. The survey assessed HIV transmission beliefs and sexual practices with regular male partners in the past three months. Sixty-nine of 109 (63.3%) had been in a regular relationship and 42 reported having had anal sex. Unprotected receptive anal intercourse without ejaculation (URAI - e) was associated with awareness that their most recent BPVL was detectable (>50 RNA copies/mL) and not taking ART. Receptive UAI with ejaculation (URAI + e) was associated with not taking ART, having a sexually transmissible infection and having an HIV-positive partner; the latter was also associated with insertive UAI with ejaculation (UIAI + e). Treatment optimism was not associated with UAI. In this cohort, sexual practices were based more upon knowledge of biomedical factors rather than attitudes regarding transmission risks.

Linkage mapping of CVD risk traits in the isolated Norfolk Island population.

To understand the underlying genetic architecture of cardiovascular disease (CVD) risk traits, we undertook a genome-wide linkage scan to identify CVD quantitative trait loci (QTLs) in 377 individuals from the Norfolk Island population. The central aim of this research focused on the utilization of a genetically and geographically isolated population of individuals from Norfolk Island for the purposes of variance component linkage analysis to identify QTLs involved in CVD risk traits. Substantial evidence supports the involvement of traits such as systolic and diastolic blood pressures, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, body mass index and triglycerides as important risk factors for CVD pathogenesis. In addition to the environmental influences of poor diet, reduced physical activity, increasing age, cigarette smoking and alcohol consumption, many studies have illustrated a strong involvement of genetic components in the CVD phenotype through family and twin studies. We undertook a genome scan using 400 markers spaced approximately 10 cM in 600 individuals from Norfolk Island. Genotype data was analyzed using the variance components methods of SOLAR. Our results gave a peak LOD score of 2.01 localizing to chromosome 1p36 for systolic blood pressure and replicated previously implicated loci for other CVD relevant QTLs.

Linkage disequilibrium analysis in the genetically isolated Norfolk Island population.

Norfolk Island is a human genetic isolate, possessing unique population characteristics that could be utilized for complex disease gene localization. Our intention was to evaluate the extent and strength of linkage disequilibrium (LD) in the Norfolk isolate by investigating markers within Xq13.3 and the NOS2A gene encoding the inducible nitric oxide synthase. A total of six microsatellite markers spanning approximately 11 Mb were assessed on chromosome Xq13.3 in a group of 56 men from Norfolk Island. Additionally, three single nucleotide polymorphisms (SNPs) localizing to the NOS2A gene were analyzed in a subset of the complex Norfolk pedigree. With the exception of two of the marker pairs, one of which is the most distantly spaced marker, all the Xq13.3 marker pairs were found to be in significant LD indicating that LD extends up to 9.5-11.5 Mb in the Norfolk Island population. Also, all SNPs studied showed significant LD in both Norfolk Islanders and Australian Caucasians, with two of the marker pairs in complete LD in the Norfolk population only. The Norfolk Island study population possesses a unique set of characteristics including founder effect, geographical isolation, exhaustive genealogical information and phenotypic data of use to cardiovascular disease risk traits. With LD extending up to 9.5-11 Mb, the Norfolk isolate should be a powerful resource for the localization of complex disease genes.

Efavirenz and chronic neuropsychiatric symptoms: a cross-sectional case control study.

OBJECTIVE: The aim of the study was to investigate symptoms of long-term central nervous system (CNS) toxicity in HIV-positive patients treated with efavirenz (EFV). METHODS: We carried out a single-centre, cross-sectional case-control study comparing patients treated with EFV for at least 6 months with a matched control group. Self-administered, standardized questionnaires including the Depression, Anxiety and Stress Scales (DASS), the Cognitive Failures Questionnaire (CFQ) and a questionnaire on unusual dreams, insomnia, fatigue, dizziness, depersonalization and derealization were administered. RESULTS: Data for 32 matched pairs were analysed. Significantly higher total stress scores (P=0.008) were found in the EFV group. Of the patients in this group, 19% also reported severe to extremely severe levels of stress (P=0.014), indicating increased difficulty in relaxing, and being more irritable, impatient, agitated and easily upset. Nineteen per cent of patients treated with EFV also reported severe levels of anxiety (P=0.059) as assessed with the DASS scale. This patient group also reported a higher rate of unusual dreams (P=0.049). No significant differences between groups were found for measures of cognitive impairments, fatigue, dizziness, derealization or depersonalization. CONCLUSION: EFV-treated patients reported higher levels of severe stress and anxiety as well as a higher rate of unusual dreams than patients not treated with EFV. These differences may be an expression of persisting CNS side effects in patients who remain on EFV for a prolonged period.

Tandem mass spectrometry methods for definitive protein identification in proteomics research.

Optimized procedures have been developed for the addition of sulfonic acid groups to the N-termini of low-level peptides. These procedures have been applied to peptides produced by tryptic digestion of proteins that have been separated by two-dimensional (2-D) gel electrophoresis. The derivatized peptides were sequenced using matrix-assisted laser desorption/ionization (MALDI) post-source decay (PSD) and electrospray ionization-tandem mass spectrometry methods. Reliable PSD sequencing results have been obtained starting with sub-picomole quantities of protein. We estimate that the current PSD sequencing limit is about 300 fmol of protein in the gel. The PSD mass spectra of the derivatized peptides usually allow much more specific protein sequence database searches than those obtained without derivatization. We also report initial automated electrospray ionization-tandem mass spectrometry sequencing of these novel peptide derivatives. Both types of tandem mass spectra provide predictable fragmentation patterns for arginine-terminated peptides. The spectra are easily interpreted de novo, and they facilitate error-tolerant identification of proteins whose sequences have been entered into databases.

Development and evaluation of an inventory for rating client satisfaction with outcome in HIV counseling: the Albion Center scale.

We developed an inventory for rating client satisfaction with outcome in HIV counseling, based on interview responses with clients. The resulting 19-item scale was subject to factor analysis and four factors, accounting for 56% of the variance, emerged. The factors described dimensions of Perception of progress and improved mood; Recognition of a specific need for counseling; Behavior change from counseling; and Counseling climate. Factor-scored scales were significantly associated with time in counseling and for the Specific need for counseling scale, HIV-seropositive respondents had a significantly higher score. Scale reliabilities (Cronbach's alpha) were between 0.85 and 0.50. Concurrent administration with the Counseling Evaluation Inventory indicated that there were significant correlations between the two scales.

The Mental Adjustment to HIV scale: measurement and dimensions of response to AIDS/HIV disease.

Attitudes of people with HIV disease towards HIV have seldom been measured. However, a well-established scale to measure attitudes toward cancer in those with the disease, the 38-item Mental Adjustment to Cancer (MAC) scale was modified to assess adjustment to HIV disease. We administered the scale to 107 Australian men with HIV infection, of whom 36 had an AIDS-defining condition, who were patients at an ambulatory care facility and in a research study. The data were factor analyzed using a method identical to that used in the development of the MAC scale to determine the latent dimensions of attitudes toward HIV/AIDS. The Mental Adjustment to HIV scale (MAH) factor analysis revealed five factors: Helplessness-Hopelessness, Fighting Spirit, and Denial-Avoidance as in the original MAC scale, plus a Fatalism subscale which also measured Preoccupation, and a new subscale, which measured Belief in Influencing the Course of the Disease. Together, these five factors accounted for half of the variance. These data suggest that while there are similarities between mental attitude to cancer and mental attitude to HIV in the latent dimensions of the questionnaire items, there are also some differences. Most significant is the belief in people with HIV disease in being able to personally influence the course of the illness, and the combination of Preoccupation with Fatalism. The five subscales of the MAH scale had Cronbach's alpha reliabilities between 0.80 and 0.55. The MAH appears to be a useful way to measure total attitudes and subscale scores of people with HIV infection, including AIDS, to their disease.

Comparative metabolism of bis(2-methoxyethyl)ether in isolated rat hepatocytes and in the intact rat: effects of ethanol on in vitro metabolism.

The metabolism of the reproductive and developmental toxicant bis(2-methoxyethyl)ether (diglyme) was studied in isolated rat hepatocytes and in the intact rat. Male Sprague-Dawley rats (190-220 g) were used in both studies. Hepatocytes, isolated by a two-step in situ collagenase perfusion of the liver, were cultured as monolayers and incubated with [14C]diglyme at 1, 10, 30, and 50 microM for up to 48 h. For the in vivo study, rats were given single oral doses of [14C]diglyme at 5.1 mmol/kg body wt, and urine was collected for up to 96 h. Radioactive compounds in the culture medium or in the urine were separated by high performance liquid chromatography and quantified with an in-line radioactivity monitor. Metabolites were identified by comparison of their chromatographic retention times and their mass spectra with those of authentic compounds. The principal metabolite from hepatocytes and in the urine was (2-methoxyethoxy)acetic acid (MEAA). This metabolite accounted for approximately 36% of the radioactivity in the 48-h culture medium and about 67% of the administered dose in the 48-h urine. Other prominent metabolites common to both systems included 2-(2-methoxyethoxy)ethanol, methoxyacetic acid (MAA), 2-methoxyethanol, and diglycolic acid. The diglyme metabolite profiles from urine and from hepatocytes were qualitatively similar, demonstrating that, in the rat, hepatocytes serve as a good model system for predicting the urinary metabolites of diglyme. Moreover, MEAA was shown to be the metabolite best suited for use as a short-term biological marker of exposure to diglyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Membrane anchoring of the autoantigen GAD65 to microvesicles in pancreatic beta-cells by palmitoylation in the NH2-terminal domain.

Pancreatic beta-cells and gamma-aminobutyric acid (GABA)-secreting neurons both express the enzyme glutamic acid decarboxylase (GAD) which is a major target of autoantibodies associated with beta-cell destruction and impairment of GABA-ergic neurotransmitter pathways. The predominant form of GAD in pancreatic beta-cells, GAD65, is synthesized as a soluble hydrophilic molecule, which is modified to become firmly membrane anchored. Here we show by immunogold electron microscopy that GAD65 is localized to the membrane of small vesicles which are identical in size to small synaptic-like microvesicles in pancreatic beta-cells. The NH2-terminal domain of GAD65 is the site of a two-step modification, the last of which results in a firm membrane anchoring that involves posttranslational hydroxylamine sensitive palmitoylation. GAD65 can be released from the membrane by an apparent enzyme activity in islets, suggesting that the membrane anchoring step is reversible and potentially regulated. The hydrophobic modifications and consequent membrane anchoring of GAD65 to microvesicles that store its product GABA may be of functional importance and, moreover, significant for its selective role as an autoantigen.

Pancreatic beta cells express two autoantigenic forms of glutamic acid decarboxylase, a 65-kDa hydrophilic form and a 64-kDa amphiphilic form which can be both membrane-bound and soluble.

The 64-kDa pancreatic beta-cell autoantigen, which is a target of autoantibodies associated with early as well as progressive stages of beta-cell destruction, resulting in insulin-dependent diabetes (IDDM) in humans, has been identified as the gamma-aminobutyric acid-synthesizing enzyme glutamic acid decarboxylase. We have identified two autoantigenic forms of this protein in rat pancreatic beta-cells, a Mr 65,000 (GAD65) hydrophilic and soluble form of pI 6.9-7.1 and a Mr 64,000 (GAD64) component of pI 6.7. GAD64 is more abundant than GAD65 and has three distinct forms with regard to cellular compartment and hydrophobicity. A major portion of GAD64 is hydrophobic and firmly membrane-anchored and can only be released from membrane fractions by detergent. A second portion is hydrophobic but soluble or of a low membrane avidity, and a third minor portion is soluble and hydrophilic. All the GAD64 forms have identical pI and mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results of pulse-chase labeling with [35S]methionine are consistent with GAD64 being synthesized as a soluble protein that is processed into a firmly membrane-anchored form in a process which involves increases in hydrophobicity but no detectable changes in size or charge. All the GAD64 forms can be resolved into two isoforms, alpha and beta, which differ by approximately 1 kDa in mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis but are identical with regard to all other parameters analyzed in this study. GAD65 has a shorter half-life than the GAD64 forms, remains hydrophilic and soluble, and does not resolve into isomers. Comparative analysis of the brain and beta-cell forms of GAD show that GAD65 and GAD64 in pancreatic beta-cells correspond to the larger and smaller forms of GAD in brain, respectively. The expression of different forms and the flexibility in subcellular localization of the GAD autoantigen in beta-cells may have implications for both its function and autoantigenicity.

Bis(2-methoxyethyl) ether: metabolism and embryonic disposition of a developmental toxicant in the pregnant CD-1 mouse.

An embryotoxic oral dose of bis(2-methoxyethyl) ether (DGDME), 3.73 mmol/kg body wt (500 mg/kg), administered on the 11th day of gestation to pregnant CD-1 mice was metabolized predominantly by O-demethylation to 2-(2-methoxyethoxy)ethanol with subsequent oxidation to (2-methoxyethoxy)acetic acid. Urinary excretion of this metabolite over 48 hr amounted to 63 +/- 2% of the dose. A smaller percentage of the administered dose was metabolized at the central ether linkage to produce 2-methoxyethanol, which was further metabolized by alcohol dehydrogenase to methoxyacetic acid. Urinary excretion of methoxyacetic acid, a potent developmental toxicant, amounted to 28 +/- 1% of the administered dose by 48 hr and was the second most prominent urinary metabolite. Unchanged DGDME and methoxyacetic acid were detected in the embryonic tissues from these animals, and embryos harvested after the initial 6-hr period showed detectable amounts of only methoxyacetic acid. The average amount of methoxyacetic acid per embryo was calculated to be 1.5 +/- 1.0 mumol (5.9 mmol/kg body wt) at the 6-hr termination time. This finding suggests that the reported teratogenic effects of DGDME are due to methoxyacetic acid formed, either in the fetus or by hepatic metabolism in the dam with subsequent distribution to the embryonic tissue. These results suggest that such developmental toxicity may occur with structurally similar aprotic ethylene glycol ethers in which metabolic O-dearylation would yield 2-methoxy-ethanol.

4,4'-Methylene-bis(2-chloroaniline) (MOCA): comparison of macromolecular adduct formation after oral or dermal administration in the rat.

The macromolecular binding of 4,4'-methylenebis(2-chloroaniline) (MOCA), a suspect human carcinogen, was studied in the adult male Sprague-Dawley rat after both oral and dermal administration. Rats were euthanized 1, 3, 7, 10, 14, and 29 days after a single 281 mumol/kg body wt dose of [14C]MOCA (oral, 213 muCi/kg; dermal, 904 muCi/kg). DNA from various tissues and hemoglobin were isolated for determination of the time course of MOCA macromolecular binding. After oral administration adduct formation was rapid with maximum levels appearing at 24 hr. The 24-hr covalent binding associated with the globin was 7.84 pmol/mg globin (t1/2 = 14.3 days). More extensive 24-hr covalent binding was detected for liver DNA with 49.11 pmol/mg DNA (t1/2 = 11.1 days). After dermal administration of MOCA the major portion of the dose, 86.2%, remained at the application site throughout the study. For these rats the 24-hr covalent binding determined for liver DNA was 0.38 pmol/mg DNA (t1/2 = 15.6 days). Although lower levels were detected after dermal application, similar stability of MOCA-DNA adducts indicates that quantification of such MOCA adducts may be useful for the long-term industrial biomonitoring of MOCA exposure and for the evaluation of human DNA-MOCA adduct formation, a lesion thought to be associated with the production of cancer.

The role of enzyme induction on metabolite formation of bis(2-methoxyethyl) ether in the rat.

The effect of enzyme induction on the metabolism of the reproductive toxicant bis (2-methoxyethyl) ether (diglyme) was studied in male Sprague-Dawley rats. Rats were given either daily doses of diglyme at 5.1 mmol/kg body wt. by gavage or 0.1% (w/v) phenobarbital (PB) in the drinking water for 22 consecutive days. In one study, a significant reduction in the hexobarbital sleeping time was determined for rats pretreated with diglyme or PB in comparison with that determined for naive rats. In a second study, naive and pretreated rats given single oral doses of 14C-diglyme at 5.1 mmol/kg body wt. showed similar urinary 14C excretion patterns. Urinary metabolites were separated and quantified by hplc to evaluate the influence of pretreatment with either diglyme or PB on the 14C-diglyme urinary metabolite profile. The amount of (2-methoxyethoxy) acetic acid, the principal metabolite, was similar for rats given no pretreatment and for rats pretreated with either diglyme or PB. However, both pretreatments resulted in significant increases in the formation of methoxyacetic acid, a recognized reproductive toxicant.

Structural and evolutionary analysis of the two chimpanzee alpha-globin mRNAs.

Two distinct alpha-globin mRNAs were detected in chimpanzee reticulocyte mRNA using a primer extension assay. DNA copies of these two mRNAs were cloned in the bacterial plasmid pBR322, and their sequence was determined. The two alpha-globin mRNAs have obvious structural homology to the two human alpha-globin mRNAs, alpha 1 and alpha 2. Comparison of the two chimpanzee alpha-globin mRNAs to each other and to their corresponding human counterparts revealed evidence of a recent gene conversion in the human alpha-globin complex and a marked heterogeneity in the rate of structural divergence within the alpha-globin gene.