Roles of liver fluke infection as risk factor for cholangiocarcinoma

Several factors are known to be associated with risk of cholangiocarcinoma (CCA) and infection with the liver flukes, Opisthorchis viverrini and Clonorchis sinensis, has often been singled out as the leading risk factor in east and southeast Asia. In this review, current knowledge of their biology, life cycle, and pathogenesis of O. viverrini, and its role as a carcinogenic parasite are presented. The trends of age‐specific incidence of liver cancer in Khon Kaen, northeast Thailand are considered and compared with the prevalence profiles of O. viverrini. Potential impacts of the liver fluke control program particularly by mass drug administration (MDA) and public health education in the past and a recent drop of incidence of CCA are discussed in relation to primary prevention and control of this fatal bile duct cancer.     

Gastric volvulus caused by percutaneous endoscopic gastrostomy: a case report

Percutaneous endoscopic gastrostomy is commonly performed for enteric feeding in children with neurologic impairment because of its low rates of complication. We report a case of gastric volvulus, an unusual complication, after percutaneous endoscopic gastrostomy procedure in our institution.     

Protection of Xanthomonas against arsenic toxicity involves the peroxide-sensing transcription regulator OxyR

Arsenic has been shown to mediate its toxicity through induced generation of reactive oxygen species. Here, we examined the role of oxidative stress-inducible genes (katA, ahpC and ohr) and their regulators (oxyR and ohrR) in the response to arsenic treatment in a plant pathogenic bacterium, Xanthomonas campestris pv. phaseoli (Xp). Overproduction of peroxide-scavenging enzymes (KatA, AhpCF and Ohr) did not enhance arsenic tolerance in wild-type Xp. Furthermore, inactivation of katA, ahpC, ohr, and ohrR genes had no effect on the level of arsenic resistance. By contrast, an oxyR mutant (Xp oxyR) showed increased sensitivity to both pentavalent arsenate and, to a greater extent, trivalent arsenite. The resistance of cells to arsenite treatment was significantly affected by the level of iron. Cells were 10-fold more sensitive to arsenite killing in the presence of excess iron, while removal of iron by an iron chelator (2,2'-dipyridyl) protected Xanthomonas from arsenite toxicity. The arsenite-sensitive phenotype of Xp oxyR could be complemented by the expression of functional OxyR from a plasmid vector, but not by the expression of other known OxyR-regulated peroxide-scavenging enzymes such as KatA and AhpCF, Ohr and OhrR. The data suggested that as yet unidentified, OxyR-regulated gene(s) are involved in conferring arsenic resistance in Xp. To our knowledge, this is the first report showing that the peroxide-sensing regulator OxyR is involved in arsenic resistance.     

Genetic characterization of Echinostoma revolutum and Echinoparyphium recurvatum (Trematoda: Echinostomatidae) in Thailand and phylogenetic relationships with other isolates inferred by ITS1 sequence

Echinostomatidae are common, widely distributed intestinal parasites causing significant disease in both animals and humans worldwide. In spite of their importance, the taxonomy of these echinostomes is still controversial. The taxonomic status of two species, Echinostoma revolutum and Echinoparyphium recurvatum, which commonly infect poultry and other birds, as well as human, is problematical. Previous phylogenetic analyses of Southeast Asian strains indicate that these species cluster as sister taxa. In the present study, the first internal transcribed spacer (ITS1) sequence was used for genetic characterization and to examine the phylogenetic relationships between an isolate from Thailand with other isolates available from GenBank database. Interspecies differences in ITS1 sequence between E. revolutum and E. recurvatum were detected at 6 (3%) of the 203 alignment positions. Of these, nucleotide deletion at positions 25, 26, and 27, pyrimidine transition at 50, 189, and pyrimidine transversion at 118 were observed. Phylogenetic analysis revealed that E. recurvatum from Thailand clustered as a sister taxa with E. revolutum and not with other members of the genus Echinoparyphium. Interestingly, this result confirms a previous report based on allozyme electrophoresis and mitochondrial DNA that E. revolutum and E. recurvatum in Southeast Asia are sister species. Hence, the taxonomic status of E. recurvatum in Thailand, as well as in Southeast Asian countries needs to be confirmed and revised using more comprehensive analyses based on morphology and other molecular techniques.     

A novel nuclear marker,Pm-int9, for phylogenetic studies of <Emphasis Type="Italic">Opisthorchis felineus</Emphasis>, <Emphasis Type="Italic">Opisthorchis viverrini</Emphasis>, and <Emphasis Type="Italic">Clonorchis sinensis</Emphasis> (Opisthorchiidae,Trematoda)

Opisthorchis felineus, O. viverrini, and Clonorchis sinensis, the trematodes of the family Opisthorchiidae, are important human parasites. Two previous studies (Kang et al. Parasitol Int 57:191–197, 2008; Katokhin et al. Dokl Biochem Biophys 421:214–217, 2008) have provided evidence using ribosomal and mitochondrial sequences that O. viverrini, O. felineus, and C. sinensis are closely related. We developed a novel nuclear marker, Pm-int9, which included the ninth intron of the paramyosin gene and flanking exon sequences. Samples of O. felineus from four localities of West Siberia, C. sinensis from the Russian Far East, and O. viverrini from Thailand were genotyped by Pm-int9. Little variation was detected in exon sequences, however, intron sequences turned out to be more variable than ribosomal internal transcribed spacers. We can conclude that Pm-int9 is valuable for interspecific variation studies. Phylogenetic analysis based on Pm-int9 revealed that O. viverrini and C. sinensis were closer to each other than either of them to O. felineus, supporting the opinion that C. sinensis should be considered the sister species of Opisthorchis spp.     

Thai War on Drugs: measuring changes in methamphetamine and other substance use by school students through matched cross sectional surveys

In 2003 the Thai government announced a radical shift in drug policy with the implementation of a War on Drugs. Although consequences of this controversial measure (e.g. drug dealer deaths) have received widespread attention relatively little work has evaluated changes in substance use. We used two anonymous representative samples of secondary school students to compare drug use in Northeast Thailand before (1998; n=4217) and after (2004/5; n=3489) the War on Drugs. Results indicate that reported levels of current illicit drug use reduced significantly between 1998 and 2004/5 (for methamphetamine from 4.2% to 0.9%). By examining trends in year of first methamphetamine use we identify that observed reductions in drug initiation are temporally consistent with the War on Drugs. However, while prevalence of alcohol use has also fallen, there was a three-fold increase in daily alcohol use. We suggest that this rise, combined with other negative impacts of 'wars' on drugs, means drug control requires a public health perspective that sees eliminating drug use as part of a wider strategy that has improvement in population health, not just drug prevention, as its core objective.     

Quantitation of in vitro coronary artery calcium using ultrafast computed tomography

Ultrafast computed tomography (UFCT) has the potential to quantify coronary hydroxyapatite (HAP). However, no definitive studies validating this technique are available. We constructed a human chest phantom model with coronary arteries represented by cylindrical holes containing: (1) calcium chloride solutions, (2) a block of HAP immersed in paraffin (without partial volume effect), and (3) HAP granules embedded in a gelatin matrix (with partial volume effect). We scanned this model to determine the relationship between measured CT number per voxel and density of the calcium per voxel. The relationships between CT number and concentration of calcium chloride was linear (r = 0.992 to 0.999). Using a commercially available standard bone mineral phantom, we were able to estimate the concentration of HAP to an accuracy from 94 to 97% when partial volume effects were absent. However, when partial volume effects were present, two methods of estimating HAP produced significant errors (1 to 384%, and 17 to 52%). We conclude that significant partial voluming errors degrade the accuracy of HAP quantitation and that further evaluation and corrections are needed before such quantitation is clinically applied. © 1994 Wiley-Liss,Inc..     

Isolated tuberculosis of tunica vaginalis in a child

We reported a case of tuberculosis of tunica vaginalis which can present as an acute scrotum.     

Renal magnesium wasting and tubular dysfunction in leptospirosis.

BACKGROUND: Tubulo-interstitial nephritis is the main cause of acute renal injury in leptospirosis. The aim of this study was to evaluate renal tubular function and excretion of solutes in leptospirosis patients during a recent outbreak of leptospirosis in Nan province, Thailand. METHODS: Clinical manifestations were recorded and routine laboratory tests were performed upon admission. Renal tubular functions including tubular reabsorption of phosphate (TRP), fractional excretion of magnesium (FE(Mg)), urinary calcium to creatinine ratio (Uca/cr), urine N-acetyl-beta-D glucosaminidase (NAG) and urine beta(2)-microglobulin were serially monitored during 2 weeks after admission. RESULTS: A total of 20 leptospirosis patients were recruited. Nine (45%) patients had acute renal failure (ARF). Increased urine NAG and beta(2)-microglobulin, which indicate proximal tubular dysfunction, were demonstrated in all 20 (100%) patients. Fifteen (75%) patients had hypermagnesuria, whereas 10 (50%) patients had decreased TRP. Renal magnesium (Mg) and phosphate (P) wasting caused hypomagnesaemia and hypophosphataemia in nine and three patients with ARF, respectively. These abnormal findings significantly improved within 2 weeks after admission. CONCLUSIONS: We conclude that renal Mg and P wasting commonly occur in patients with leptospirosis. The measurement of Mg and P levels in both serum and urine of leptospirosis patients, especially those with ARF, is therefore highly recommended.