Genetic diversity on the tropical rare wood species of Dalbergia in Vietnam revealed by inter-simple sequence repeat (ISSR) markers

Genetic diversities of three rare hardwood species of Dalbergia (D. assamica, D. nigrescens and D. tonkinensis) were evaluated for conservation based on inter-simple sequence repeat (ISSR) markers. A total of 47 ISSR primers were used for the analysis, but only 31 ISSR primers were successfully amplified for 25 samples from each species. There were 166 fragments across the 75 samples produced, in which 153 were polymorphic with an average of 4.94 polymorphic fragments per primer. The number of amplified fragments ranged from 1 (ISSR13, ISSR54 and ISSR59) to 11 (ISSR14) and their size varied from 200 to 1700 bp. The similarity coefficient ranged from 67.0 to 98.9% in D. assamica; from 71.2 to 98.5% in D. nigrescens and from 68.5 to 95.2% in D. tonkinensis. The estimated value of molecular diversity parameters within species such as the effective number of alleles, Shannon's information index, intralocus gene diversity and Nei’s gene diversity were low among the individuals of the different Dalbergia species (1.227, 0.195, 0.662 and 0.146, respectively in D. assamica; 1.135, 0.111, 0.425 and 0.109, respectively in D. nigrescens; 1.198, 0.166, 0.526 and 0.123, respectively in D. tonkinensis). The analysis of molecular variance (AMOVA) of ISSR data indicated that the greater proportion of total genetic variation existed among species rather than within species. The correlation between genetic and geographic distance was also found in the three Dalbergia species.Key words: Dalbergia, endemic species, genetic similarity, ISSR markers

Genetic interaction between two VNTRs in the MAOA gene is associated with the nicotine dependence

Nicotine dependence is an addiction to tobacco products and a global public health concern that in part would be influenced by our genetics. Smokers are reported to have reduced MAOA activity, but the results from genetic associations with this gene have been inconclusive. Two functionally relevant variable number tandem repeat (VNTR) domains, termed uVNTR and dVNTR, in the MAOA gene are well characterized transcriptional regulatory elements. In the present study, we analyzed uVNTR and dVNTR polymorphisms in the MAOA gene in the Vietnamese male population of smokers and non-smokers in order to assess the association of MAOA with the nicotine dependence measured by the Fagerström Test for Nicotine Dependence (FTND). Individual analysis of VNTRs separately identified uVNTR to be associated with the F6 question of the FTND indicating the stronger addiction to nicotine. No associations were found between the dVNTR and smoking behavior. The combination of dVNTR and uVNTR, that predicts low expression of MAOA (10–3 haplotypes), was significantly associated with the higher nicotine dependence (FTND score), longer smoking duration, and more persistent smoking behavior (fewer quit attempts). In conclusion, our study confirms that low MAOA expression is genetically predictive to the higher nicotine dependence

Lack of knowledge about sexually transmitted infections among women in North rural Vietnam

<p>Abstract</p> <p>Background</p> <p>The serious long-term complications of sexually transmitted infections (STI) in women and newborns are well-documented. Particularly, STI imply considerable social consequences for women. Low STI knowledge has been shown to be associated with unsafe sex. In Vietnam, misconceptions regarding STI exist, and rural women delay seeking care for STI. The aim of the study was to investigate knowledge of STI among women aged 15 to 49 years in a rural district of Vietnam and to evaluate possible associations between socioeconomic factors and STI knowledge.</p> <p>Methods</p> <p>A cross-sectional population-based study using face-to-face interviews was carried out between March and May 2006 in a demographic surveillance site in rural Vietnam. In total, 1805 women aged 15–49 years were randomly selected to participate in the study. The interviews were based on a structured questionnaire including questions on sociodemographic characteristics of the women and their knowledge about STI. Each correct answer was scored 1, incorrect or do not know answer was scored 0. Multivariate analyses were applied to examine associations between socio-economic conditions and STI knowledge. Intra-cluster correlation was calculated to examine similarities of STI knowledge within clusters.</p> <p>Results</p> <p>Of the 1,805 respondents, 78% (73% married vs. 93% unmarried, p < 0.001) did not know any symptoms of STI, 50% could not identify any cause of STI, 59% (54% married vs. 76% unmarried, p < 0.001) did not know that STI can be prevented. Only 31% of the respondents (36% married vs. 14% unmarried, p < 0.001) answered that condom use could protect against STI, and 56% considered partner treatment necessary. Of 40 possible correct answers, the mean knowledge score was 6.5 (range 0–26, median 6). Young, unmarried women and women who lived in the highlands or mountainous areas demonstrated very low levels of STI knowledge (regression coefficients -1.3 and -2.5, respectively, p < 0.001). Experience of an induced abortion was significantly associated with a higher level of knowledge.</p> <p>Conclusion</p> <p>The low levels of STI knowledge found among women of reproductive age in a rural district of Vietnam indicate an urgent need of health education interventions, of which, young and unmarried women should be specifically targeted.</p

A Non Mouse-Adapted Dengue Virus Strain as a New Model of Severe Dengue Infection in AG129 Mice

The spread of dengue (DEN) worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Progress in understanding DEN pathogenesis and in developing effective treatments has been hampered by the lack of a suitable small animal model. Most of the DEN clinical isolates and cell culture-passaged DEN virus strains reported so far require either host adaptation, inoculation with a high dose and/or intravenous administration to elicit a virulent phenotype in mice which results, at best, in a productive infection with no, few, or irrelevant disease manifestations, and with mice dying within few days at the peak of viremia. Here we describe a non-mouse-adapted DEN2 virus strain (D2Y98P) that is highly infectious in AG129 mice (lacking interferon-α/β and -γ receptors) upon intraperitoneal administration. Infection with a high dose of D2Y98P induced cytokine storm, massive organ damage, and severe vascular leakage, leading to haemorrhage and rapid death of the animals at the peak of viremia. In contrast, very interestingly and uniquely, infection with a low dose of D2Y98P led to asymptomatic viral dissemination and replication in relevant organs, followed by non-paralytic death of the animals few days after virus clearance, similar to the disease kinetic in humans. Spleen damage, liver dysfunction and increased vascular permeability, but no haemorrhage, were observed in moribund animals, suggesting intact vascular integrity, a cardinal feature in DEN shock syndrome. Infection with D2Y98P thus offers the opportunity to further decipher some of the aspects of dengue pathogenesis and provides a new platform for drug and vaccine testing

Metals and kidney markers in adult offspring of endemic nephropathy patients and controls: a two-year follow-up study

Abstract Background The etiology of Balkan Endemic Nephropathy, (BEN), a tubulointerstitial kidney disease, is unknown. Although this disease is endemic in rural areas of Bosnia, Bulgaria, Croatia, Romania, and Serbia, similar manifestations are reported to occur in other regions, for instance Tunisia and Sri Lanka. A number of explanations have been stated including lignites, aristolochic acid, ochratoxin A, metals, and metalloids. Etiologic claims are often based on one or a few studies without sound scientific evidence. In this systematic study, we tested whether exposures to metals (cadmium and lead) and metalloids (arsenic and selenium) are related to Balkan Endemic Nephropathy. Methods In 2003/04 we recruited 102 adults whose parents had BEN and who resided in one of three communities (Vratza, Bistretz, or Beli Izvor, Bulgaria). A control group comprised of 99 adults having non-BEN hospitalized parents was enrolled in the study during the same time. We conducted face-to-face interviews, ultrasound kidney measurements, and determined kidney function in two consecutive investigations (2003/04 and 2004/05). Metals and metalloids were measured in urine and blood samples. To assess the agreement between these consecutive measurements, we calculated intraclass correlation coefficients. Repeated measurement data were analyzed using mixed models. Results We found that cadmium and arsenic were associated with neither kidney size nor function. Lead had a significant but negligible effect on creatinine clearance. Selenium showed a weak but significant negative association with two of the four kidney parameters, namely creatinine clearance and β2-microglobulin. It was positively related to kidney length. These associations were not restricted to the offspring of BEN patients. Adding credence to these findings are reports showing comparable kidney effects in animals exposed to selenium. Conclusion The findings of this 2-year follow-up study indicate that metals and metalloids do not play a role in the etiology of Balkan Endemic Nephropathy. Against the assumption in the literature, selenium was not protective but a risk factor. Since comparable associations were observed in animals, future studies are needed to explore whether selenium may have adverse renal effects in humans.</p

Diagnosis of pulmonary tuberculosis in HIV-positive patients by microscopic observation drug susceptibility assay.

The microscopic observation drug susceptibility assay (MODS) is a novel and promising test for the early diagnosis of tuberculosis (TB). We evaluated the MODS assay for the early diagnosis of TB in HIV-positive patients presenting to Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases in southern Vietnam. A total of 738 consecutive sputum samples collected from 307 HIV-positive individuals suspected of TB were tested by smear, MODS, and the mycobacteria growth indicator tube method (MGIT). The diagnostic sensitivity and specificity of MODS compared to the microbiological gold standard (either smear or MGIT) were 87 and 93%, respectively. The sensitivities of smear, MODS, and MGIT were 57, 71, and 75%, respectively, against clinical gold standard (MODS versus smear, P&lt;0.001; MODS versus MGIT, P=0.03). The clinical gold standard was defined as patients who had a clinical examination and treatment consistent with TB, with or without microbiological confirmation. For the diagnosis of smear-negative patients, the sensitivities of MODS and MGIT were 38 and 45%, respectively (P=0.08). The median times to detection using MODS and MGIT were 8 and 11 days, respectively, and they were 11 and 17 days, respectively, for smear-negative samples. The original bacterial/fungal contamination rate of MODS was 1.1%, while it was 2.6% for MGIT. The cross-contamination rate of MODS was 4.7%. In conclusion, MODS is a sensitive, specific, and rapid test that is appropriate for the detection of HIV-associated TB; its cost and ease of use make it particularly useful in resource-limited settings