Factors associated with willingness to participate in HIV vaccine trials among high-risk populations in South India

Abstract Successful conduct of any HIV vaccine trial (HIVVT) requires a high level of preparedness in the community. A cross-sectional study was conducted in Tamilnadu, India among 501 participants from six different risk groups to investigate their willingness to participate (WTP) in future preventive HIVVTs and to explore their knowledge and attitude toward preventive HIV vaccines. In total, 82% were willing to participate and the desire to be protected from HIV was the main reason for WTP. Perception of not being at risk was the major reason for refusal among married women. The knowledge scale showed a significant increase in scores after vaccine education. In all, 76% revealed the hope that there would be an effective vaccine in a few years and 71% hoped that the HIV vaccine would protect them from HIV infection. The main concern was the unknown efficacy of the vaccine (50%) and the effects of an HIV vaccine on participants' lives (51%). Overall, 76% agreed that sex without a condom would not be safe whether or not there was an HIV vaccine. To conclude, it is likely that high-risk volunteers will be willing to enroll in preventive HIVVTs. Addressing barriers and concerns by providing information through appropriate agencies will spell out success for preventive HIVVTs in India.

Mosquito larvicidal activity of isolated compounds from the rhizome of Zingiber officinale

The larvicidal activity of a petroleum ether extract of Zingiber officinale Roscoe (Zingiberaceae) was evaluated against Aedes aegypti L. and Culex quinquefasciatus Say (Diptera). Bioassay-guided fractionation led to the isolation of 4-gingerol (1), (6)-dehydrogingerdione (2) and (6)-dihydrogingerdione (3); the latter has not previously been reported from Z. officinale. The structures were established from infrared (IR), ultraviolet (UV), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectral data. Following a 24 h exposure, compounds 1-3 exhibited larvicidal activities against fourth instar larvae of A. aegypti (LC(50) 4.25, 9.80, 18.20 ppm) and C. quinquefasciatus (LC50 5.52, 7.66, 27.24 ppm), respectively. The results show that the most effective compound was 4-gingerol.

Effect of salinity on the predatory performance of Diplonychus rusticus (Fabricius)

Predatory efficiency of Diplonychus rusticus (Fabricius) was recorded at different prey density with different salinity ranges. When the salinity level (ppt) was increased, the predation rate of the bug decreased. Fifth nymphal stage showed higher predation in the 2, 4 and 6 ppt levels of salinityin both 1 hr and 24 hr period of exposure at prey densities 50, 100, 150 and 200. At prey density 150, adult bugs killed more prey in the 2 ppt level of salinity in both lhr and 24 hr treatments.

Mosquito larvicidal activity of gluanol acetate, a tetracyclic triterpenes derived from Ficus racemosa Linn

The larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone, and methanol extracts of the leaf and bark of Ficus racemosa (Moraceae) was assayed for their toxicity against the early fourth-instar larvae of Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24-h exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in bark acetone extract of F. racemosa. In the present study, bioassay-guided fractionation of acetone extract led to the separation and identification of a tetracyclic triterpenes derivative; gluanol acetate was isolated and identified as new mosquito larvicidal compound. Gluanol acetate was quite potent against fourth-instar larvae of Aedes aegypti L. (LC(50) 14.55 and LC(90) 64.99 ppm), Anopheles stephensi Liston (LC(50) 28.50 and LC(90) 106.50 ppm) and C. quinquefasciatus Say (LC(50) 41.42 and LC(90) 192.77 ppm). The structure was elucidated from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data. This is the first report on the mosquito larvicidal activity of the reported compound from F. racemosa.

Tuberculin skin test results in HIV-infected patients in India: implications for latent tuberculosis treatment

OBJECTIVE

To evaluate the utility of the tuberculin skin test (TST) in detecting latent and active tuberculosis (TB) among human immunodeficiency virus (HIV) infected patients in South India.

DESIGN

TSTs and CD4 counts were collected from 631 HIV-infected individuals without active TB and 209 antiretroviral and anti-tuberculosis treatment-naïve HIV-infected patients with TB. We calculated the proportion of TST-positive individuals, as well as the sensitivity, specificity, positive predictive value (PPV) and negative predictive value of TST in the diagnosis of TB.

RESULTS

Among subjects without active TB, 28% with a CD4 count <100 cells/microl vs. 43% of the total cohort had a TST >5 mm (P = 0.14), while the proportions with induration >10 mm were 14% vs. 36%, respectively (P < 0.01). Among those with active TB, using a 5 mm cut-off, the sensitivity was 42% for those with CD4 counts <200 cells/mul compared to 70% for those with CD4 counts >or=200 cells/microl (P < 0.001). The PPV for detecting active TB was 29%.

CONCLUSIONS

TST is a poor predictor of both latent and active TB in HIV-infected individuals in TB endemic countries. Programmes offering treatment for latent TB should consider including all HIV-positive patients regardless of TST status, or use other indicators, such as CD4 count.

Long term follow up of HIV-infected patients with tuberculosis treated with 6-month intermittent short course chemotherapy

BACKGROUND

Tuberculosis occurs in 60%-70% of HIV-positive persons in India. The outcome of HIV-positive patients treated with 6-month intermittent short course antituberculosis regimens in India is not well described.

METHODS

This was a prospective observational feasibility study of 71 patients with HIV and tuberculosis who were treated with category I regimen of the Revised National Tuberculosis Control Programme (ethambutol, isoniazid, rifampicin and pyrazinamide thrice weekly for the initial 2 months followed by rifampicin and isoniazid thrice weekly for the next 4 months). Sputum was examined by smear and culture for Mycobacterium tuberculosis every month up to 24 months. Chest X-ray, CD4 cell count and viral load were done prior to and at the end of treatment. None of the patients received antiretroviral therapy.

RESULTS

We present here the treatment response of patients with sputum culture-positive pulmonary tuberculosis to category I regimen. By efficacy analysis, among 43 patients treated with category I regimen, sputum smear conversion was observed in 79% and culture conversion in 82% at the second month. A favourable response was seen in 72% of patients. The mean (SD) CD4% fell from 12.6 (5.9) to 8.9 (4.9) (p < 0.001) with no significant change in mean (SD) CD4 cell count (169 [126] to 174 [158]; ns) at the end of treatment. Viral load change from 1.8 x 10(5) at baseline to 1.3 x 10(5) at the end of treatment was not statistically significant. Thirty-one patients, who completed the full course of treatment, were declared cured and were followed up for 24 months. Twelve had recurrent tuberculosis (39%); 16 of 43 (37%) patients had died by the end of 24 months, two-thirds due to causes other than tuberculosis.

CONCLUSION

Though the early bacteriological response to intermittent short course antituberculosis regimen was satisfactory, the overall outcome was adversely affected by the high mortality (during and after completion of treatment) and recurrence rate among HIV-infected patients with tuberculosis. Immune status deteriorated in spite of antituberculosis treatment, highlighting the need for antiretroviral treatment in addition to antituberculosis treatment to improve the long term outcome. The results of this pilot study need to be confirmed by larger studies.

Effect of n-3 fatty acid supplementation on blood glucose, lipid profile and cytokines in humans: A pilot study

This study was undertaken to evaluate the effects of n-3 fatty acid supplementation on blood glucose, lipid profile and cytokines in humans. Twenty adult healthy subjects were supplemented with 1g/day fish oil concentrate capsules for 2 weeks. Fasting blood samples were taken at baseline and again after 2 week intervention. Fish oil supplementation significantly lowered fasting serum concentrations of total cholesterol, triacylglycerol, very low density lipoprotein and low density lipoprotein (P < 0.01). Also high density lipoprotein increased significantly compared with baseline value (P < 0.01). Fish oil did not significantly altere the fasting blood glucose concentration but significantly reduced the serum cytokines (P < 0.001). This study demonstrated that eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) supplementation altered serum lipids, lipoprotein and cytokine concentrations in normal human subjects even at the small dose of 660 mg of EPA plus DHA per day. It appears that EPA plus DHA can be a safe and perhaps beneficial supplement to inflammatory diseases.

Larvicidal activity of some Euphorbiaceae plant extracts against Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae)

Larvicidal activity of ethyl acetate, butanol, and petroleum ether extracts of five species of Euphorbiaceae plants, Jatropha curcas, Pedilanthus tithymaloides, Phyllanthus amarus, Euphorbia hirta, and Euphorbia tirucalli, were tested against the early fourth instar larvae of Aedes aegypti L. and Culex quinquefasciatus (Say). The larval mortality was observed after 24 h of exposure. All extracts showed low larvicidal effects; however, the highest larval mortality was found in petroleum ether extract. The LC50 value of petroleum ether extracts of J. curcas, P. tithymaloides, P. amarus, E. hirta, and E. tirucalli were 8.79, 55.26, 90.92, 272.36, and 4.25 ppm, respectively, against A. aegypti and 11.34, 76.61, 113.40, 424.94, and 5.52 ppm, respectively, against C quinquefasciatus. Of the various ratios tested, the petroleum ether extracts of J. curcas and E. tirucalli were observed to be more efficient than the other plant extracts. It is, therefore, suggested that E. tirucalli can be applied as an ideal potential larvicide against A. aegypti and C. quinquefasciatus. This is an ideal ecofriendly approach for the control of the dengue vector, A. aegypti, and the lymphatic filariasis vector, C. quinquefasciatus.

Site-directed alkylation and the alternating access model for LacY

In a functional lactose permease mutant from Escherichia coli (LacY) devoid of native Cys residues, almost every residue was replaced individually with Cys and tested for reactivity with the permeant alkylating agent N-ethylmaleimide in right-side-out membrane vesicles. Here we present the results in the context of the crystal structure of LacY. Engineered Cys replacements located near or within the inward-facing hydrophilic cavity or at other solvent-accessible positions in LacY react well with this alkylating agent. Cys residues facing the low dielectric of the membrane or located in tightly packed regions of the structure react poorly. Remarkably, in the presence of ligand, increased reactivity is observed with Cys replacements located predominantly on the periplasmic side of the sugar-binding site. In contrast, other Cys replacements largely on the cytoplasmic side of the binding site exhibit decreased reactivity. Furthermore, both sets of Cys replacements in the putative cavities are located at the periplasmic (increased reactivity) and cytoplasmic (decreased reactivity) ends of the same helices and distributed in a pseudosymmetrical manner. The results are consistent with a model in which the single sugar-binding site in the approximate middle of the molecule is alternately exposed to either side of the membrane due to opening and closing of cytoplasmic and periplasmic hydrophilic cavities.

Phage cocktail to control the exponential growth of normal flora in processed sputum specimens grown overnight in liquid medium for rapid TB diagnosis

The mechanical pressure exerted during centrifugation and the chemical pressure experienced when sputum specimens are processed, leave the tubercle bacilli in the sputum unsuitable for rapid detection especially in phage based assays. Thus, growing Mycobacterium tuberculosis in broth, at least overnight, is mandatory for allowing the tubercle bacilli to recoup. During this time the surviving colonizing flora grow faster and overgrow tubercle bacilli interfering with TB diagnosis. In the present study normal flora surviving the action of 4% NaOH was isolated and characterized. Phages capable of killing 14 different species representing this normal flora were isolated from soil and sewage samples and characterized. A novel and bio-friendly approach to treat sputum samples with a cocktail of three phages capable of killing most of the 14 representative organisms and not infecting mycobacteria is explored to control the overgrowth of colonizing bacteria in broth culture. While 26 of the 100 sputum samples processed by modified Petroff's procedure showed growth of colonizing flora on blood agar, all of them when grown in broth overnight showed mixed, confluent growth. The addition of phagebiotics controlled them all, showing a significant reduction in colony forming units but resulting in few discrete colonies in 54 samples. Isolation of phages capable of controlling these surviving organisms and including them in the phagebiotics mixture should lead to the control of colonizing bacteria effectively.

A pilot study on willingness to participate in future preventive HIV vaccine trials

BACKGROUND & OBJECTIVES

In India, phase-I human clinical trials for a preventive HIV vaccine are being conducted at Pune and Chennai Centres. In order to find out the willingness of populations at risk to participate in future preventive HIV vaccine trials (HIVVTs) and to assess the factors that enhance or deter them from participation, a study was conducted at Chennai and Madurai in Tamil Nadu.

METHODS

This cross-sectional study was conducted among transport workers, people attending sexually transmitted infection clinics, injection drug users, men having sex with men, women in sex industry and a representative sample of monogamous married women, by employing measurement scales. A structured questionnaire on knowledge and attitudes about the HIV vaccine was used to measure the participants' knowledge and attitudes about HIV vaccine and HIVVTs.

RESULTS

Of the 112 participants, 67 (60%) were men. Mean age of the respondents was 32 yr; 68 per cent were high school educated. Majority of respondents were willing to participate in a future HIVVT and the reasons were altruism, protection from HIV, and support for the researchers. Major concerns were vaccine efficacy, side effects of the vaccine and the impact of a HIV vaccine on the participants' lives. Majority (85%) agreed that sex without condom would not be safe despite the availability of an HIV vaccine.

INTERPRETATION & CONCLUSION

It is likely that high-risk volunteers will be willing to enroll in HIVVTs. Barriers and concerns should be dealt with carefully by providing correct information. Also there is a need for more education to ensure participants' understanding of key concepts of HIV vaccine trial.

Simple and rapid liquid chromatography method for determination of efavirenz in plasma

A simple and rapid high performance liquid chromatographic method for determination of efavirenz in human plasma was developed. The method involved extraction of sample with ethyl acetate and analysis using a reversed-phase C(18) column (150 mm) with UV detection. The assay was linear from 0.0625 to 10.0 microg/ml. The method was specific for efavirenz estimation and the drug was stable in plasma up to one month at -20 degrees C. The average recovery of efavirenz from plasma was 101%. Due to its simplicity, the assay can be used for pharmacokinetic studies and therapeutic drug monitoring of efavirenz.

A comprehensive back-calculation framework for estimation and prediction of HIV/AIDS in India

HIV incubation period is the random time between the HIV-infection and the onset of clinical AIDS. Distribution of this non-negative random variable is known as HIV incubation period distribution. The Back-calculation method reconstructs the past pattern of HIV infection and predicts the future number of AIDS cases with the present infection status. It depends on three important factors: incubation distribution, incidence curve and observed number of AIDS cases over time. This method is very popular and requires less information and assumptions. Lack of information about incubation distribution, the effect of intervention therapy on incubation period, and errors in reported AIDS incidence leads to uncertainties associated with this method. The incubation distribution is assumed to be exactly known in back-calculation methodology. Incubation period of HIV is very long and highly variable within and between cohorts. The current prevalence of HIV-infection and the corresponding pattern of incidence from the beginning of the epidemic to the present time are mainly estimated by means of back-calculation method. It calculates the most likely temporal distribution of infected individuals compatible with the number of observed AIDS cases starting from the suitable estimate of the incubation period, derived from the available data. Most of the projections formulated the problem of estimation of future AIDS cases as estimation of parameters in multinomial likelihood with unknown sample size by EM algorithm. In this paper the various approaches for modeling the incubation distribution are compared using real and simulated data under various infection density distributions. The projected minimum AIDS cases in India based on the reported data for the years 2003, 2004, 2005 and 2006 are around 27000, 44000, 70000 and 113000 respectively. The corresponding figures based on the adjusted data are around 67000,100000,150000 and 230000 respectively.

Bactericidal action of gatifloxacin, rifampin, and isoniazid on logarithmic- and stationary-phase cultures of Mycobacterium tuberculosis

The bactericidal activity of gatifloxacin, alone and in combination with isoniazid and rifampin, was studied on both exponential- and stationary-phase cultures of Mycobacterium tuberculosis strain H37Rv. On log-phase cultures, the bactericidal activity of gatifloxacin at 4 microg/ml was rapid and was very similar to that of isoniazid. At concentrations of 0.25 and 4 microg/ml, gatifloxacin enhanced the activity of isoniazid. Killing of the stationary-phase culture was biphasic. During the first 2 days, gatifloxacin at 4 microg/ml slightly increased the limited bactericidal activities of isoniazid and rifampin. However, no further additional bactericidal activity was found during further incubation with isoniazid alone or when gatifloxacin was added to either isoniazid or rifampin. This suggested that the stationary-phase culture contained a mixture of occasionally dividing bacilli that were killed during the first 2 days and true static persisters in the residual population that mimicked those in human lesions. In view of the failure of gatifloxacin to add to the sterilizing activity of isoniazid or rifampin during days 2 to 6 of exposure in the stationary-phase culture, it is unlikely to be a sterilizing drug that can be used to shorten the duration of treatment appreciably when it is added to present treatment regimens.

Decreased bioavailability of rifampin and other antituberculosis drugs in patients with advanced human immunodeficiency virus disease

We evaluated the effects of human immunodeficiency virus (HIV) disease on pharmacokinetics of antituberculosis medications by measuring concentrations of isoniazid and rifampin in blood and of pyrazinamide and ethambutol in urine. Peak concentration and exposure were reduced for rifampin, and rapid acetylators of isoniazid had lower drug levels. HIV and HIV-tuberculosis patients who have diarrhea and cryptosporidial infection exhibit decreased bioavailability of antituberculosis drugs.

Seasonality of presentation of imported Plasmodium vivax malaria in Birmingham, UK

Residents of the UK returning from northern Pakistan with Plasmodium vivax infection tend to develop symptoms and present to hospital in the summer months, irrespective of the month of return. Thus, infections acquired in the cooler months of November to April appear to have a longer latency before presentation. Experiments suggest that more hypnozoites arise from the liver when ambient temperatures fall, somehow 'programming' parasites within biting mosquitoes.

HIV alters plasma and M. tuberculosis-induced cytokine production in patients with tuberculosis

To test the hypothesis that HIV infection brings about an alteration in the immune response to tuberculosis (TB), mycobacterial antigen-induced production and plasma levels of the inflammatory cytokine interferon-gamma (IFN-gamma) and its regulatory cytokines interleukin-12 (IL-12), IL-18, and IL-10 were determined in patients infected dually with HIV and TB and compared with individuals with either disease and with healthy controls. Peripheral blood mononuclear cells (PBMCs) of TB patients with HIV infection produced lesser amounts of IFN-gamma and IL-12 compared with TB patients without HIV infection after in vitro stimulation with mycobacterial antigens. There was no difference in antigen-induced IL-18 production in TB patients with or without HIV infection. The in vivo cytokine pattern did not correlate with that seen in vitro. Higher levels of IFN-gamma, IL-12, and IL-18 were detected in the plasma of TB patients infected with HIV compared with TB patients without HIV infection. The presence of significantly higher plasma levels of proinflammatory cytokines suggests a greater degree of immune activation in individuals with HIV and TB, particularly those with low CD4 counts. In vitro IL-10 production by HIV-positive TB patients was similar to that of the HIV-negative TB group and higher than in HIV-positive individuals without TB, but the plasma levels were similar. HIV infection downregulates the in vitro Th1 cytokine response to TB and simultaneously increases systemic levels of these cytokines.

Vitamin A levels in sputum-positive pulmonary tuberculosis patients in comparison with household contacts and healthy 'normals'

OBJECTIVE

To estimate serum vitamin A in pulmonary tuberculosis (PTB) patients at the start and end of anti-tuberculosis treatment.

DESIGN

Serum vitamin A was estimated in 47 PTB patients (pre and post treatment), 46 healthy household contacts and 30 healthy 'normals'.

RESULTS

Mean serum vitamin A in patients at the start of treatment was 21.2 microg/dl, which was significantly lower than in household contacts (42.2 microg/dl) and healthy 'normals' (48.1 microg/dl). The vitamin A levels in patients increased following treatment.

CONCLUSION

The low vitamin A levels observed in patients returned to normal at the end of anti-tuberculosis treatment without vitamin A supplementation.

Unrecognised tuberculosis in HIV-infected patients: sputum culture is a useful tool

Diagnosis of tuberculosis is challenging, especially in human immunodeficiency virus (HIV) positive persons who may have atypical clinical and radiographic features. We report the isolation of Mycobacterium tuberculosis from sputum samples of 10 (4%) HIV-positive persons who were asymptomatic with normal chest radiographs and negative sputum smears for acid-fast bacilli. Six of them had strongly positive tuberculin reactions while four were severely immunosuppressed. Our observation highlights the utility of routine sputum culture in the diagnosis of tuberculosis in high-risk individuals.