Viral hepatitis infections among dialysis patients: Thailand registry report

BACKGROUND: Patients on dialysis are at high risk of acquiring viral hepatitis infections. However, there were only few data from Thailand. The aim of the present study was to assess the prevalence, incidence and associated risk factors of viral hepatitis infections among dialysis patients. METHODS: A retrospective study was conducted to evaluate 5179 medical records of dialysis patients from the Thailand Renal Replacement Therapy Registry. RESULTS: In 2002, the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were 6.3% (n = 2454) and 4.8% (n = 2167), respectively. HBV and HCV seroprevalence became 6.5% (n = 2585) and 4.3% (n = 2399) in 2003. The incidence of HBV and HCV infections were 1.5 and 2.4 cases per 1000 patient-years, respectively. Logistic regression analysis showed that age and gender were significant risk factors for HBV infection, but not for HCV infection. CONCLUSION: In Thailand, it was not uncommon for dialysis patients to acquire viral hepatitis infections. However, our prevalence is similar to reports from some other South-East Asian countries.     

Root fracture detection on digital images: effect of the zoom function

Abstract ‐ Objectives: To assess the accuracy of root fracture detection at various levels of image magnification. Methods: Extracted single‐rooted human teeth (100 non‐fractured and 101 fractured) were mounted singly in wax blocks and a charge‐coupled device (CCD)‐based digital Sidexis imaging system was used to take images using the paralleling technique. Image sizes 1 : 1, 2 : 1, and 1 : 2 were prepared for each tooth. All 603 images were examined randomly and interpreted by an experienced radiologist unaware of which images were of fractured roots. The degree of agreement between image interpretation and the actual condition was estimated using a kappa statistic. A modified goodness‐of‐fit χ²‐test was used to assess the significance of the difference between the three image sizes. The sensitivity, specificity, predictive value, and likelihood ratio were used to evaluate the accuracy of root fracture detection at each level of magnification. The degree of agreement between pairs of viewing conditions was also calculated using a kappa statistic. Results: There was substantial agreement between image interpretation and the actual condition for both the 1 : 1 and 1 : 2 image sizes but only moderate agreement for the 2 : 1 size. The kappa values (and 95% CIs) were 0.65 (0.51–0.79), 0.63 (0.49–0.77), and 0.58 (0.44–0.72), respectively. The differences were not statistically significant (P‐value = 0.79). The sensitivity (95% CI) of the image magnification ranged between 79.0% (70.0–87.5%) and 81.0% (72.2–87.5%). The 1 : 1 image size gave the highest specificity of 86.1% (95% CI: 78.1–91.6%). The positive predictive values (95% CI) of the 1 : 1, 1 : 2, and 2 : 1 images sizes were 84.9% (76.3–90.8%), 81.8% (73.1–88.2%), and 77.9% (69.0–84.8%), respectively. The negative predictive values (95% CI) were 80.6% (72.1–86.9%), 81.4% (73.8–88.9%), and 80.4% (71.4–87.1%) for the 1 : 1, 1 : 2, and 2 : 1 image sizes, respectively. The likelihood ratios of the positive test (95% CI) were 5.70 (3.47–9.36), 4.55 (3.00–6.98), and 3.56 (2.45–5,16) for the 1 : 1, 1 : 2, and 2 : 1 image sizes, respectively. The likelihood ratios of the negative test (95% CI) were 0.24 (0.17–0.36), 0.23 (0.15–0.35), and 0.25 (0.16–0.37) for the 1 : 1, 1 : 2, and 2 : 1 image sizes, respectively. The reliability between pairs of viewing conditions was substantial. The kappa statistics (95% CI) was 0.80 (0.72–0.88), 0.73 (0.64–0.83), and 0.77 (0.68–0.86), respectively. Conclusion: In this in vitro study, the three digital magnifications used did not affect the detection of root fractures.     

Neurotoxicity of Coscinium fenestratum stem, a medicinal plant used in traditional medicine.

Coscinium fenestratum is a common medicinal plant widely used in the Indochina region, but scientific data on its safety is very limited. This study aimed to observe the effect of this plant on neurotoxicity and neurobehavior. Oral administration of plant alcoholic extract at dosages of 5, 10 and 20 mg/kgBW for 14 days increased the rats body weight and decreased the neuron density in the cerebral cortex, hippocampus and striatum. The plant extract significantly increased stereotyped behavior in licking but did not cause anxiolytic activity, anti-depression, sensory motor co-ordination impairment and ataxia. It is concluded that the plant possesses neurotoxicity and is able to induce neurobehavioral changes in rats. Therefore, the application of this plant as either drug or supplementary food should be reconsidered.     

Complex genetic structure of the rabies virus in Bangkok and its surrounding provinces, Thailand: implications for canine rabies control

Dog vaccination and population management have been suggested as priorities in attempts at disease control in canine rabies-endemic countries. Budget limitations and the complexity of social, cultural and religious variables have complicated progress in the developing world. In Bangkok, Thailand, an intensive canine vaccination and sterilization programme has been in place since November 2002. Our objective was to determine if the rabies virus could be mapped according to its genetic variations and geographical location on the small localized scale of Bangkok and its surrounding provinces. Phylogenetic characterization of 69 samples from Bangkok and five neighbouring and two remote provinces, by limited sequence analysis of the rabies virus nucleoprotein gene, distinguished six different clades. Rabies viruses of four clades were intermixed in Bangkok and in the surrounding highly populated regions whereas the other two clades were confined to rural and less populated provinces. Such a complex pattern of gene flow, particularly in Bangkok, may affect the outcome of canine control programmes.     

Magnetic resonance imaging abnormalities in right ventricular outflow tract tachycardia and the prediction of radiofrequency ablation outcome

BACKGROUND: Recent reports have shown abnormalities on cardiac magnetic resonance imaging (MRI) in patients with right ventricular outflow tract (RVOT) tachycardia. Objectives: Objectives of this study were to demonstrate abnormalities on MRI and signal-averaged ECG (SAECG) in patients with RVOT tachycardia and their correlation with the outcome of radiofrequency (RF) ablation. METHODS: We studied 41 patients with symptomatic RVOT tachycardia and 15 controls. SAECG and cardiac MRI were performed on every subject. An evaluation of structural abnormality, chamber size, function, and wall motion abnormality of the left and right ventricle was performed by MRI. Focal wall thinning was evaluated by the black blood technique and fatty infiltration was evaluated by the T1 image with and without fat suppression. RESULTS: MRI abnormalities were demonstrated in 24 (58.5%) patients with RVOT tachycardia. The abnormalities included localized wall bulging in 22 (53.7%), focal wall thinning in 10 (24.4%), and fatty replacement in 9 (22%) patients. MRI abnormality was found in only one patient in the control group (P < 0.001). Late potentials from SAECG were demonstrated in six (10.7%) patients but none in the controls (P = 0.117). Among 29 patients who underwent RF ablation, 3 patients had a failed procedure and 3 having arrhythmia recurrence needed repeated ablation. MRI abnormalities and late potentials were associated with an unfavorable outcome of RF ablation. CONCLUSIONS: MRI abnormalities were frequently found in patients with RVOT tachycardia. MRI abnormalities and late potentials can predict outcomes of RF ablation.     

Incidence of HIV-1 infection and effects of clinic-based counseling on HIV preventive behaviors among married women in northern Thailand

To determine the incidence of and risk factors for HIV-1 infection among married women in northern Thailand, we enrolled 779 seronegative women from family planning clinics and a postpartum ward in Chiang Rai, Thailand, from 1998 through 1999. Women were tested for HIV antibodies at 6 and 12 months after enrollment. They received HIV prevention counseling at enrollment and at each follow-up visit. Counseling covered partner communication, partner HIV testing, and condom use by steady partners. Effects of counseling were measured using standardized questionnaires. Follow-up rates were 94% at 6 months and 92% at 12 months. Only 1 woman seroconverted during the follow-up period, yielding an overall HIV incidence of 0.14 per 100 person-years. After receiving counseling, women reported significantly increased communication with husbands concerning HIV risk, HIV testing, and condom use during the first 6 months after enrollment; communication remained high for 6 to 12 months. Women reported a modest increase in HIV testing and consistent condom use by husbands. The risk for HIV transmission to women in steady relationships is low in northern Thailand. Although HIV prevention counseling promoted partner communication, its effects on HIV preventive behaviors were limited.     

Floating properties and release characteristics of hollow microspheres of acyclovir

Acyclovir, a selective antiherpes virus agent, was loaded in the hollow microspheres to improve bioavailability and patient compliance by prolonging the residence time in the gastrointestinal tract. The hollow microspheres of acyclovir were prepared by solvent evaporation diffusion method using Eudragit S 100 as a controlled polymer. We found that the process conditions that provided the high % yield of the hollow microspheres were the use of 5:8:2 of dichloromethane: ethanol: isopropanol as a solvent system and stirring at 300 rpm for 60 min. The size of the microspheres prepared from different ratios of acyclovir and Eudragit S 100 was 159-218 microm. When the drug-to-polymer ratio was increased, the size and percent drug content increased. The highest percent drug entrapment was obtained at the ratio of 600 mg acyclovir: 1 g Eudragit S 100. The hollow microspheres tended to float over 0.1 M hydrochloric acid containing 0.02% Tween 20 solution for 24 hr. The rate of acyclovir released from the microspheres was generally low in simulated gastric fluid without enzyme due to the low permeability of the polymer. However, in phosphate buffer pH 6.8, the drug release increased as the drug load increased due to the swelling property of the polymer. In simulated intestinal fluids without enzymes, the polymer completely dissolved resulting in instant release of the drug in this medium.     

Limited and Short-Lasting Virus Neutralizing Titers Induced by Inactivated SARS-CoV-2 Vaccine

In vitro determination of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies induced in serum samples from recipients of the CoronaVac vaccine showed a short protection period against the original virus strain and limited protection against variants of concern. These data provide support for vaccine boosters, especially variants of concern circulate.