Susceptible and Protective HLA Class 1 Alleles against Dengue Fever and Dengue Hemorrhagic Fever Patients in a Malaysian Population

BACKGROUND: The human leukocyte antigen alleles have been implicated as probable genetic markers in predicting the susceptibility and/or protection to severe manifestations of dengue virus (DENV) infection. In this present study, we aimed to investigate for the first time, the genotype variants of HLA Class 1(-A and -B) of DENV infected patients against healthy individuals in Malaysia. METHODOLOGY/PRINCIPAL FINDINGS: This study was carried out with 92 dengue disease patients and 95 healthy controls from three different ethnic groups (Malay, Chinese and Indian) in Malaysia. All patients with clinical and laboratory confirmation of DENV infection were typed for the HLA-A and B loci, using polymerase chain reaction-sequence specific primer techniques. In our total population, a significant increase for HLA-B*53 (P = 0.042, Pc = 1.008) allele and a significant decrease for A*03 (P = 0.015, Pc = 0.18, OR = 5.23, 95% CI = 1.19-23.02) and B*18 (P = 0.017, Pc = 0.408) alleles were noted in DHF patients as compared to healthy donors. We also observed that in the Malay DHF patients, allele B*13 (P = 0.049, Pc = 1.176, OR = 0.18, 95% CI = 0.03-0.90) was present at a significantly higher frequency in this population while allele HLA-B*18 (P = 0.024, Pc = 0.576) was seen to be negatively associated with DHF. CONCLUSIONS/SIGNIFICANCE: These are the first findings on genetic polymorphisms in our population and we conclude that: (1) In our total population, HLA-B*53 probably involve in disease susceptibility, while the HLA-A*03 and HLA-B*18 may confer protection from progression to severe disease; (2) In the Malay population, HLA-B*13 and B*18 are probably associated in disease susceptibility and protection, respectively. These results could furnish as a valuable predictive tool to identify ethnically different individuals at risk and/or protection from severe forms of DENV infection and would provide valuable informations for the design of future dengue vaccine

Effect of media and environmental factors on growth and cellulase production by microporus xanthopus

Microporus xanthopus obtained from peat swamp forest at University Malaysia Sarawak (UNIMAS) was identified. Effects of media and environmental factors on growth of M. xanthopus were studied. M. xanthopus was grown on potato dextrose agar (PDA), potato carrot agar (PCA) and malt extract agar (MEA) at room temperature. This fungus grew significantly faster, at P=O.OS on PDA compared to growth on PCA or MEA The effect of light on growth of M. xanthopus was studied by growing this fungus on PDA in light and dark condition at room temperature. The fungus grew significantly faster, at P=O.OS in dark condition after 96 hours of incubation. The effect of temperature was studied by growing M. xanthopus on PDA and incubated at lSoC, 20°C, 2SoC, 30°C and 3S°C, in dark condition. Optimum growth was obtained at 30°C and no growth was recorded at 3S°C. The effect of pH was studied by growing M. xanthopus in potato extract broth (PDE) and incubated at 30°C in dark condition. The pH of the media used were; S.O, 6.0,6.5, 7.0, 8.0 and 9.0. The highest average mycelium dried weight of the fungus was obtained at pH 6.0. Study on cellulase production of the fungus was carried out by conformation test on carboxylmethycellulose (CMC) media and growth on B-V11 medium. Effect of concentrations of nitrogen sources (NH4)2S04, yeast extract and KN03 on cellulase activity in shake-flask cultures was also observed. Cellulase activity was determined using dinitrosalicylic acid (DNS) enzyme assay and protein content was determined using Bradford protein assay. Yeast extract, 6g!l, gave the highest value of cellulase specific activity (0.98IlmoVmin/mg) on day 6. This fungus was able to produce cellulase in media contain all the nitrogen sources except (N~hS04

Evaluation of a Dengue NS1 capture ELISA assay for the rapid detection of Dengue

Background: Early definitive diagnosis of dengue virus infections is essential for the timely management of dengue infections. In this study, we evaluated the PanBio Dengue NS1 Antigen Capture ELISA for the detection of dengue virus NS1 antigen in patients’ sera.Methodology: A total of 206 serum samples and 8 viral isolates were used to evaluate the kits. These samples were analysed using TaqMan RT-PCR, an in-house IgM ELISA, a hemagglutination inhibition (HI) assay, and the PanBio NS1 ELISA.Results: Out of the 66 culture positive sera that tested positive using the TaqMan RT-PCR, NS1 antigen was detected in 91% with sensitivity being higher in primary acute sera than in secondary acute sera. The detection rate by PanBio Dengue NS1 Antigen Capture ELISA in the absence of IgM was 91.6% as compared to 48.3% in the presence of IgM. The overall sensitivity of the PanBio Dengue NS1 Antigen Capture ELISA in the detection of dengue in culture positive sera was 91.6%.Conclusions: The PanBio ELISA is a highly specific and sensitive assay for the detection of dengue NS1 antigen. The assay was able to detect NS1 antigen in convalescent sera up until day 10 of infection, whereas viral RNA was undetectable via PCR by day 7. However, as it is most effective during the acute phase of the disease, this kit should be used together with the IgM to increase the sensitivity of detection, especially in areas with higher prevalence of secondary dengue virus infections

The potential benefits of rainwater harvesting for households in the Jaffna peninsula [Abstract only]

Recent development activities in the Jaffna Peninsula are threatening the viability of the region's natural groundwater supply. Rainwater Harvesting (RWH) represents one important approach to remedying this situation. By accumulating freshwater during Jaffna's wet season, household RWH systems can supply drinking and cooking water for use during the water-limited dry season. Additionally, a RWH calculator created by the International Water Management Institute (IWMI) can be used to customize a RWH system for each family given particular household parameters such as rooftop size and daily extraction rate. When paired with cost estimates for tank construction, a RWH installation cost-benefit analysis can be determined for either a specific household or for a collection of households within the Jaffna region

HLA-A, and -B allele frequencies in control subjects (ethnically and geographically matched, healthy Malaysian individuals).

<p>HLA = human leukocyte antigen; AF = allele frequency (as percentage).</p><p>Bold alleles are the predominant alleles present at frequencies more than 5%.</p

Negative associations of HLA alleles in DHF patients in different races.

<p>n = number of patients; <i>P</i> = <i>p</i> value derived from fisher exact test; <i>Pc</i> = corrected <i>P</i> value; OR = Odds Ratio; CI = confidence interval; PT = patients; CTRL = controls; AF = allele frequency in percentage; Number in bold indicate (*) significant <i>P</i> value; Number in bold indicate nearing significant <i>P</i> value In Pearson chi-square analysis, where a value in a 2×2 table was 0, the OR and 95% CI could not be calculated (NA, not available).</p

HLA-A, and -B allele frequencies in Malaysian individuals with dengue virus infection (dengue fever and dengue hemorrhagic fever).

<p>HLA = human leukocyte antigen; AF = allele frequency (as percentage).</p><p>Bold alleles are the predominant alleles present at frequencies more than 5%.</p

Food Allergy and Intolerance: A Narrative Review on Nutritional Concerns

Adverse food reactions include immune-mediated food allergies and non-immune-mediated intolerances. However, this distinction and the involvement of different pathogenetic mechanisms are often confused. Furthermore, there is a discrepancy between the perceived vs. actual prevalence of immune-mediated food allergies and non-immune reactions to food that are extremely common. The risk of an inappropriate approach to their correct identification can lead to inappropriate diets with severe nutritional deficiencies. This narrative review provides an outline of the pathophysiologic and clinical features of immune and non-immune adverse reactions to food—along with general diagnostic and therapeutic strategies. Special emphasis is placed on specific nutritional concerns for each of these conditions from the combined point of view of gastroenterology and immunology, in an attempt to offer a useful tool to practicing physicians in discriminating these diverging disease entities and planning their correct management. We conclude that a correct diagnostic approach and dietary control of both immune- and non-immune-mediated food-induced diseases might minimize the nutritional gaps in these patients, thus helping to improve their quality of life and reduce the economic costs of their management

A nonstructural protein 1 capture enzyme-linked immunosorbent assay specific for dengue viruses.

Dengue non-structural protein (NS1) is an important diagnostic marker during the acute phase of infection. Because NS1 is partially conserved across the flaviviruses, a highly specific DENV NS-1 diagnostic test is needed to differentiate dengue infection from Zika virus (ZIKV) infection. In this study, we characterized three newly isolated antibodies against NS1 (A2, D6 and D8) from a dengue-infected patient and a previously published human anti-NS1 antibody (Den3). All four antibodies recognized multimeric forms of NS1 from different serotypes. A2 bound to NS1 from DENV-1, -2, and -3, D6 bound to NS1 from DENV-1, -2, and -4, and D8 and Den3 interacted with NS1 from all four dengue serotypes. Using a competition ELISA, we found that A2 and D6 bound to overlapping epitopes on NS1 whereas D8 recognized an epitope distinct from A2 and D6. In addition, we developed a capture ELISA that specifically detected NS1 from dengue viruses, but not ZIKV, using Den3 as the capture antibody and D8 as the detecting antibody. This assay detected NS1 from all the tested dengue virus strains and dengue-infected patients. In conclusion, we established a dengue-specific capture ELISA using human antibodies against NS1. This assay has the potential to be developed as a point-of-care diagnostic tool