Changing Pattern of Dengue Virus Serotypes in Thailand between 2004 and 2010

Dengue virus infection is a major concern in several countries, and more than 50 million people are infected worldwide each year. Thailand is one of the countries where people are susceptible to infection due to favourable geographical and environmental conditions. In this retrospective study, we reported the changing pattern of dengue virus serotypes during the period between 2004 and 2010. The following percentage prevalence showed different serotypes of dengue virus (DENV) predominant in respective years: DENV1 in 2004 (56.41%), DENV4 in 2007 (50%), DENV1 in 2008 (57.41%), and DENV3 in 2010 (38.7%). Moreover, the major serotypes were not stable as they showed a shift from one serotype to another. We also found co-infection with two different serotypes and reported the clinical manifestations, which were not different from infection with a single serotype. Co-infection with various serotypes may not necessarily cause more severe disease.Key words: Co-infection, Dengue virus, Prevalence, Serotype, Thailand     

Echocardiography and fetal heart sounds in the diagnosis of fetal heart block.

A 32-week fetus was demonstrated phonocardiographically and echocardiographically to have a regular atrial rate of 150 per minute and a regular ventricular rate of 39 per minute, indicating complete heart block. The diagnosis was suspected when two groups of heart sounds at two distinct rates were heard on auscultation, and was confirmed by the postnatal ECG. The maternal history was significant for the presence of systemic lupus erythematosus. The basis for the echocardiographic diatnosis of complete heart block, the presence of atrial heart sounds in complete heart block, and the relationship of maternal SLE to congenital heart block are discussed.     

Reduced skeletal muscle inhibitor of kappaB beta content is associated with insulin resistance in subjects with type 2 diabetes: reversal by exercise training

Skeletal muscle insulin resistance plays a key role in the pathogenesis of type 2 diabetes. It recently has been hypothesized that excessive activity of the inhibitor of kappaB (IkappaB)/nuclear factor kappaB (NFkappaB) inflammatory pathway is a mechanism underlying skeletal muscle insulin resistance. However, it is not known whether IkappaB/NFkappaB signaling in muscle from subjects with type 2 diabetes is abnormal. We studied IkappaB/NFkappaB signaling in vastus lateralis muscle from six subjects with type 2 diabetes and eight matched control subjects. Muscle from type 2 diabetic subjects was characterized by a 60% decrease in IkappaB beta protein abundance, an indicator of increased activation of the IkappaB/NFkappaB pathway. IkappaB beta abundance directly correlated with insulin-mediated glucose disposal (Rd) during a hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp (r = 0.63, P = 0.01), indicating that increased IkappaB/NFkappaB pathway activity is associated with muscle insulin resistance. We also investigated whether reversal of this abnormality could be a mechanism by which training improves insulin sensitivity. In control subjects, 8 weeks of aerobic exercise training caused a 50% increase in both IkappaB alpha and IkappaB beta protein. In subjects with type 2 diabetes, training increased IkappaB alpha and IkappaB beta protein to levels comparable with that of control subjects, and these increments were accompanied by a 40% decrease in tumor necrosis factor alpha muscle content and a 37% increase in insulin-stimulated glucose disposal. In summary, subjects with type 2 diabetes have reduced IkappaB protein abundance in muscle, suggesting excessive activity of the IkappaB/NFkappaB pathway. Moreover, this abnormality is reversed by exercise training.     

Diagnostic role of serum interleukin-18 in gastric cancer patients

AIM: To determine the current status in various aspects of gastric cancer patients and to find out the clinical correlation with prognostic role of serum interleukins in Thai patients. METHODS: Sixty-eight patients were enrolled in this study at King Chulalongkorn Memorial Hospital during April 2003 to May 2005. Gastric cancer was histologically proven in 51 patients and gastric ulcer in 17 patients. Serum IL-6, IL-10, IL-12, and IL-18 levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: There were 26 males (55.32%) and 21 females (44.68%) with their age ranging from 33 to 85 years (mean age 64.49±13.83 years). The common presentations were weight loss (41.2%), dyspepsia (39.2%), and upper gastrointestinal bleeding (15.7%). A total of 35.3% gastric cancer patients and 6.3% of gastric ulcer patients were smokers (P = 0.029). Moreover, 32.4% of gastric cancer patients and 6.3% of gastric ulcer patients were alcoholic drinkers (P = 0.044). Lesion location was pyloric-antrum in 39.4%, gastric body in 39.4%, upper stomach in 12.2% and entire stomach in 6.1% of the patients. H pylori infection was detected in 44.4%. The poorly-differentiated adenocarcinoma was the most common pathologic finding (60.7%). Surgical treatment was performed in 44.1% patients (total gastrectomy in 5.9%, subtotal gastrectomy in 32.4% and palliative bypass surgery in 5.9%). Systemic chemotherapy was given as an adjuvant therapy in 8.8% patients. Carcinomatosis peritoneii were found in 18.8% patients. The mean survival time was 13.03±9.75 mo. The IL-18 level in gastric cancer patient group (58.54±43.96 pg/mL) was significantly higher than that in gastric ulcer patient group (30.84±11.18 pg/mL) (P = 0.0001) (95% CI was 42.20, 13.19). The cut point of IL-18 for diagnosis of gastric cancer was 40 pg/mL, the positive predictive value was 92.31%. The IL-6 level in gastric cancer patients with distant metastasis (20.21±9.37 pg/mL) was significantly higher than that in those with no metastasis (10.13±7.83 pg/mL) (P = 0.037) (95% CI was 19.51, 0.65). The role of IL-10 and IL-12 levels in gastric cancer patients was to provide data with no significant difference. CONCLUSION: These findings demonstrate that serum IL-6 and IL-18, but not IL-10 and IL-12 levels may be the useful biological markers of clinical correlation and prognostic factor in patients with gastric cancer. Moreover, IL-18 could serve as a diagnostic marker for gastric cancer with a high positive predictive value.     

Hepatitis B seroprevalence in Thailand: 12 years after hepatitis B vaccine integration into the national expanded programme on immunization

OBJECTIVES: To evaluate the impact of the universal hepatitis B (HB) vaccination programme on the prevalence of hepatitis B surface antigen (HBsAg) carriers and immunity to HB virus infection among children <18 years and to determine the HB seroprevalence in the Thai population. METHODS: We enrolled people in four provinces, including Chiangrai, Udon Thani, Chonburi and Nakhon Si Thammarat to geographically represent populations in the North, Northeast, Center and South of the country respectively. Serology for HBsAg, anti-hepatitis B surface (anti-HBs), and anti-hepatitis B core (anti-HBc) was tested using ELISA commercial kits. In total, 6213 subjects aged 6 months to 60 years from the four provincial hospitals and two to three district hospitals of each participating province participated. RESULTS: Overall HBsAg, anti-HBs, and anti-HBc seropositive rates amounted to 4%, 41.6% and 26.5% respectively. Of 2887 participants aged 6 months to 18 years, 2303 were born after (group I) and 584 prior to (group II) HB vaccine integration into the expanded programme on immunization of each participating province. The HBsAg seropositive rate was 0.7% among group I children and 4.3% among group II children. The prevalence rate of anti-HBc was 2.9% in group I and 15.8% in group II. In children under 18 years, the HBsAg carrier rate was 0.98% among complete vaccinees and 1.36% among participants without vaccination. CONCLUSIONS: This finding supports the efficacy of universal HB immunization in reducing the prevalence of HB infection in Thailand which is a highly endemic country.     

222 base pairs in NS5B region and the determination of hepatitis C virus genotype 6

OBJECTIVE: The present study was performed to genotype hepatitis C virus (HCV) by direct sequencing of a 222-bp nucleotide in the NS5B region and comparing the results with those of direct sequencing in the core region. We investigated a new region for HCV genotyping which gave the best performance to discriminate HCV genotype 6a, the unique genotype found in Southeast Asia. METHODS: Plasma samples taken from 57 HCV-infected blood donors were used in this study. RT-PCR products were amplified using primers located in the NS5B region. The 222-bp PCR products were purified and sequenced. The genotype of HCV isolates were obtained by phylogenetic analysis and compared with HCV reference strains stored in the GenBank database. The HCV sequences clustering in the same node were considered to be of the same genotype. RESULTS: Thirty-one, 22 and 4 samples of HCV genotype 3a, 1a and 1b, respectively, were analyzed by this method. Upon comparison with genotyping in the core region, 86 and 14% of the samples yielded concordant and discordant genotype results, respectively. The majority of discordant results (63%; 5 of 8) was observed with HCV genotype 6a which yielded 6a upon core sequencing as opposed to 1a or 3a upon NS5B sequencing. CONCLUSION: HCV genotype 6a obtained by direct sequencing in the core region could not be unequivocally arrived at by sequencing 222 bp in the NS5B region. Hence, sequencing in the core region is preferable for genotyping our specimens, even though longer PCR products are required as this method enables discrimination between genotype 6a and the remaining genotypes.     

Typing (A/B) and subtyping (H1/H3/H5) of influenza A viruses by multiplex real-time RT-PCR assays

In this study, a specific and sensitive one-step multiplex real-time RT-PCR was developed in two assays by using primers and a number of specific locked nucleic acid (LNA)-mediated TaqMan probes which increase the thermal stability of oligonucleotides. The first assay consisted of primers and probes specific to the matrix (M1) gene of influenza A virus, matrix (M1) gene of influenza B virus and GAPDH gene of host cells for typing of influenza virus and verification by an internal control, respectively. The other assay employed primers and probes specific to the hemagglutinin gene of H1, H3 and H5 subtypes in order to identify the three most prominent subtypes of influenza A capable of infecting humans. The specificity results did not produce any cross reactivity with other respiratory viruses or other subtypes of influenza A viruses (H2, H4 and H6-H15), indicating the high specificity of the primers and probes used. The sensitivity of the assays which depend on the type or subtype being detected was approximately 10 to 10(3)copies/microl that depended on the types or subtypes being detected. Furthermore, the assays demonstrated 100% concordance with 35 specimens infected with influenza A viruses and 34 specimens infected with other respiratory viruses, which were identified by direct nucleotide sequencing. In conclusion, the multiplex real-time RT-PCR assays have proven advantageous in terms of rapidity, specificity and sensitivity for human specimens and thus present a feasible and attractive method for large-scale detection aimed at controlling influenza outbreaks.