Reactivity of Blood Samples Spotted onto Filter Papers in the WST-8 Method for Screening of G6PD Deficiency.

Deficiency of glucose-6-phosphate dehydrogenase (G6PD) causes acute hemolytic anemia triggered by oxidative drugs such as primaquine. It is therefore essential in malaria-endemic areas for malaria patients to be confirmed for their G6PD activity before taking primaquine. The WST-8 method, a newly established screening method for G6PD deficiency, has been demonstrated to be suitable for field conditions, particularly for on-site malaria surveys. Here we report a laboratory evaluation by this method of the reactivity of blood-spotted filters. A time-course experiment was conducted to evaluate the reactivity of blood samples spotted onto 4 types of filter paper, Whatman 31ET Chr (ET), 3MM Chr (3MM), P81, and Advantec No. 2 (AD2). The rank of the relative reaction intensity was ET &#62; 3MM = AD2 &#62; P81. Blood-spotted filters stored at 4 degrees centigrade gradually decreased G6PD reactivity with the passage of storage time, whereas those stored at room temperature rapidly reduced their reactivity. Unexpectedly, saponin supplementation reduced the reactivity of blood-spotted filters. In conclusion, 1) ET is the most suitable filter for the WST-8 method ; 2) blood-spotted filters stored in cold condition can be assayed within 14 days, or those stored at room temperature should be tested within 3 days ; and 3) reaction mixtures should not contain saponin.</p

Seven Different Glucose-6-phosphate Dehydrogenase Variants Including a New Variant Distributed in Lam Dong Province in Southern Vietnam.

We conducted a survey for glucose-6-phosphate dehydrogenase (G6PD) deficiency using blood samples from male outpatients of a local hospital in southern Vietnam. Most of the samples were from the Kinh (88.9%), the largest ethnic group in Vietnam, with a small number (11.1%) coming from the K'Ho, Chauma, Nung, and Tay minorities. We detected 25 G6PD-deficient cases among 1,104 samples (2.3%), and read the open reading frame of G6PD. A novel mutation (352T&#62;C) predicting an aminoacid change of 118Tyr&#62;His was found in a 1-year-old Kinh boy. His G6PD activity was estimated to be less than 10% residual activity, although he did not show chronic hemolytic anemia. Thus, we categorized this variant as Class II and named it G6PD Bao Loc. In the Kinh population, G6PD Viangchan (871G&#62;A, 1311C&#62;T, intron 11 nt93T&#62;C), one of the most common variants in continental Southeast Asian populations, was the highest (6/19), followed by variants originating from the Chinese such as G6PD Canton (1376G&#62;T) (5/19), G6PD Kaiping (1388G&#62;A) (3/19), G6PD Gaohe (95A&#62;G) (1/19), and G6PD Quing Yuan (392G&#62;T) (1/19). In addition, G6PD Union (1360C&#62;T) (2/19), which originated from the Oceania, was also detected. These findings suggest that the Kinh people are derived from various ancestries from continental Southeast Asia, China, and Oceania. In contrast, all of the 5 deficient cases in the K'Ho population were G6PD Viangchan, suggesting that they were very close to Southeast Asian populations such as the Khmer in Cambodia and the Lao in Laos. It is interesting that G6PD Mahidol (487G&#62;A), another common variant in continental Southeast Asian populations in Myanmar, Thailand, and Malaysia, has not been detected from the Vietnamese

Incidence and mutation analysis of glucose-6-phosphate dehydrogenase deficiency in eastern indonesian populations

We conducted a field survey of glucose-6-phosphate dehydrogenese (G6PD) deficiency in the eastern Indonesian islands, and analyzed G6PD variants molecularly. The incidence of G6PD deficiency in 5 ethnic groups (Manggarai, Bajawa, Nage-Keo, Larantuka, and Palue) on the Flores and Palue Islands was lower than that of another native group, Sikka, or a nonnative group, Riung. Molecular analysis of G6PD variants indicated that 19 cases in Sikka had a frequency distribution of G6PD variants similar to those in our previous studies, while 8 cases in Riung had a different frequency distribution of G6PD variants. On the other hand, from field surveys in another 8 ethnic groups (Timorese, Sumbanese, Savunese, Kendari, Buton, Muna, Minahasa, and Sangirese) on the islands of West Timor, Sumba, Sulawesi, Muna and Bangka, a total of 49 deficient cases were detected. Thirty-nine of these 49 cases had G6PD Vanua Lava (383T＞C) of Melanesian origin. In our previous studies, many cases of G6PD Vanua Lava were found on other eastern Indonesian islands. Taken together, these findings may indicate that G6PD Vanua Lava is the most common variant in eastern Indonesian populations, except for Sikka

Extremely low Helicobacter pylori prevalence in North Sulawesi, Indonesia and identification of a Maori-tribe type strain: A cross sectional study

Background: Sulawesi in Indonesia has a unique geographical profile with assumed separation from Sundaland. Studies of Helicobacter pylori in this region are rare due to the region's rural location and lack of endoscopy equipment. Indirect methods are, therefore, the most appropriate for measuring H. pylori infection in these areas; with the disposable gastric brush test, we can obtain gastric juice as well as small gastric tissue samples for H. pylori culture. We investigated the prevalence of H. pylori infection and evaluated human migration patterns in the remote areas of North Sulawesi. Methods. We recruited a total of 251 consecutive adult volunteers and 131 elementary school children. H. pylori infection was determined by urine antibody test. A gastric brush test was used to culture H. pylori. We used next-generation and polymerase chain reaction based sequencing to determine virulence factors and multi-locus sequence typing (MLST). Results: The overall H. pylori prevalence was only 14.3 for adults and 3.8 for children, and 13.6 and 16.7 in Minahasanese and Mongondownese participants, respectively. We isolated a single H. pylori strain, termed -Manado-1. Manado-1 was East Asian type cagA (ABD type), vacA s1c-m1b, iceA1 positive/iceA2 negative, jhp0562-positive/β-(1,3) galT-negative, oipA "on", and dupA-negative. Phylogenetic analyses showed the strain to be hspMaori type, a major type observed in native Taiwanese and Maori tribes. Conclusions: Our data support that very low H. pylori infection prevalence in Indonesia. Identification of hspMaori type H. pylori in North Sulawesi may support the hypothesis that North Sulawesi people migrated from north. © 2014 Miftahussurur et al.; licensee BioMed Central Ltd

Further Molecular Analysis of G6PD Deficiency Variants in Southern Vietnam and a Novel Variant Designated as G6PD Ho Chi Minh (173 A>G; 58 Asp>Gly): Frequency Distributions of Variants Compared with Those in Other Southeast Asian Countries

We conducted a survey of glucose-6-phosphate dehydrogenase (G6PD) deficiency among newborn babies at Tu Du Hospital, Ho Chi Minh, southern Vietnam. A total of 90 deficient babies were detected, including 85 in the Kinh ethnic group, 4 Chinese, and 1 in the K’Ho minority group. In the Kinh ethnic group, G6PD variants such as G6PD Viangchan (n=32), Kaiping (n=11), Canton (n=8), Chinese-5 (n=7), Union (n=5) and Quing Yuan (n=4) were detected. A variant with silent mutations at 1311 C>T and IVS11 nt 93 T>C was also detected in 17 cases. A novel mutation (173 A>G) in exon 4 with a predicted amino acid change of 58 Asp>Gly was also found in a Kinh newborn girl and her father, and it was designated as G6PD Ho Chi Minh. These findings demonstrated that the Kinh ethnic group in southern Vietnam has 8 different G6PD variants, indicating that the members of this group have many ancestors in terms of G6PD variants from Southeast Asia, China, and Oceania. We compared the frequency distribution of G6PD variants in the Kinh population with those of other Southeast Asian populations, and the Kinh population’s distribution was quite similar to that in the Thai population, but differed from it by the absence of G6PD Mahidol

Testing the Gaussian expansion method in exactly solvable matrix models

The Gaussian expansion has been developed since early 80s as a powerful analytical method, which enables nonperturbative studies of various systems using `perturbative' calculations. Recently the method has been used to suggest that 4d space-time is generated dynamically in a matrix model formulation of superstring theory. Here we clarify the nature of the method by applying it to exactly solvable one-matrix models with various kinds of potential including the ones unbounded from below and of the double-well type. We also formulate a prescription to include a linear term in the Gaussian action in a way consistent with the loop expansion, and test it in some concrete examples. We discuss a case where we obtain two distinct plateaus in the parameter space of the Gaussian action, corresponding to different large-N solutions. This clarifies the situation encountered in the dynamical determination of the space-time dimensionality in the previous works.Comment: 30 pages, 15 figures, LaTeX; added references for section

Single-nucleotide polymorphism, linkage disequilibrium and geographic structure in the malaria parasite Plasmodium vivax: prospects for genome-wide association studies

<p>Abstract</p> <p>Background</p> <p>The ideal malaria parasite populations for initial mapping of genomic regions contributing to phenotypes such as drug resistance and virulence, through genome-wide association studies, are those with high genetic diversity, allowing for numerous informative markers, and rare meiotic recombination, allowing for strong linkage disequilibrium (LD) between markers and phenotype-determining loci. However, levels of genetic diversity and LD in field populations of the major human malaria parasite <it>P. vivax </it>remain little characterized.</p> <p>Results</p> <p>We examined single-nucleotide polymorphisms (SNPs) and LD patterns across a 100-kb chromosome segment of <it>P. vivax </it>in 238 field isolates from areas of low to moderate malaria endemicity in South America and Asia, where LD tends to be more extensive than in holoendemic populations, and in two monkey-adapted strains (Salvador-I, from El Salvador, and Belem, from Brazil). We found varying levels of SNP diversity and LD across populations, with the highest diversity and strongest LD in the area of lowest malaria transmission. We found several clusters of contiguous markers with rare meiotic recombination and characterized a relatively conserved haplotype structure among populations, suggesting the existence of recombination hotspots in the genome region analyzed. Both silent and nonsynonymous SNPs revealed substantial between-population differentiation, which accounted for ~40% of the overall genetic diversity observed. Although parasites clustered according to their continental origin, we found evidence for substructure within the Brazilian population of <it>P. vivax</it>. We also explored between-population differentiation patterns revealed by loci putatively affected by natural selection and found marked geographic variation in frequencies of nucleotide substitutions at the <it>pvmdr-1 </it>locus, putatively associated with drug resistance.</p> <p>Conclusion</p> <p>These findings support the feasibility of genome-wide association studies in carefully selected populations of <it>P. vivax</it>, using relatively low densities of markers, but underscore the risk of false positives caused by population structure at both local and regional levels.</p> <p>See commentary: <url>http://www.biomedcentral.com/1741-7007/8/90</url></p

Identification of helicobacter pylori infection in symptomatic patients in Surabaya, Indonesia, using five diagnostic tests

The prevalence of Helicobacter pylori infection in Indonesia is controversial. We examined the H. pylori infection rate in 78 patients in a hospital in Surabaya using five different tests, including culture, histology, immunohistochemistry, rapid urease test, and urine antibody test. Furthermore, we analysed virulence factors in H. pylori strains from Indonesia. The H. pylori infection rate was only 11·5 in all patients studied, and 2·3 of Javanese patients and 18·0 of Chinese patients were infected (P = 0·01). Although severe gastritis was not observed, activity and inflammation were significantly higher in patients positive for H. pylori than in patients negative for H. pylori. Among genotypes identified from five isolated strains, cagA was found in four; two were vacA s1m1. All cagA-positive strains were oipA 'on' and iceA1 positive. We confirmed both a low H. pylori infection rate and a low prevalence of precancerous lesions in dyspeptic patients in a Surabaya hospital, which may contribute to the low incidence of gastric cancer in Indonesia. © 2014 Cambridge University Press