Incidence of bacteremic melioidosis in eastern and northeastern Thailand

Burkholderia pseudomallei, the causative agent of melioidosis, is endemic in northeastern Thailand. Population-based disease burden estimates are lacking and limited data on melioidosis exist from other regions of the country. Using active, population-based surveillance, we measured the incidence of bacteremic melioidosis in the provinces of Sa Kaeo (eastern Thailand) and Nakhon Phanom (northeastern Thailand) during 2006-2008. The average annual incidence in Sa Kaeo and Nakhon Phanom per 100,000 persons was 4.9 (95% confidence interval [CI] = 3.9-6.1) and 14.9 (95% CI = 13.3-16.6). The respective population mortality rates were 1.9 (95% CI = 1.3-2.8) and 4.4 (95% CI = 3.6-5.3) per 100,000. The case-fatality proportion was 36% among those with known outcome. Our findings document a high incidence and case fatality proportion of bacteremic melioidosis in Thailand, including a region not traditionally considered highly endemic, and have potential implications for clinical management and health policy.     

Acute disseminated encephalomyelitis: A 10-year cohort study in Thai children

Childhood acute disseminated encephalomyelitis (ADEM) is a demyelinating disease with variable clinical courses and outcomes. Its evolution to multiple sclerosis in Asian children is yet to be determined. Medical records, investigation results and magnetic resonance imaging of brain of Thai children aged less than 15 years with initial diagnosis of ADEM at a referral university hospital in Thailand from January 1997 to December 2006 were reviewed. Clinical course and the outcome were finalized by telephone interview, self-report questionnaire, and/or neurological examination by December 2008. Modified Rankin Score was applied for determination of disability. MRI findings were categorized along with the locations and number of areas of abnormalities shown by T2-weight and FLAIR. 16 patients consisting of 5 boys and 11 girls (age-range 1–14 years, mean 6.9 ± 3.6 years, median 6 years) were identified. Nine patients had cranial nerve dysfunctions including one child with optic neuropathy. One patient died with confirmed pathological diagnosis of ADEM. Among the remaining 15, who were followed from 2 to 10 years (mean 5.8 years), 13 and 3 patients were classified into monophasic ADEM and multiple sclerosis, respectively. Ten of 13 with final diagnosis of ADEM had complete recovery. There was no association between number of lesions or location in the initial MRI and the outcome and final diagnosis. ADEM in Thai children had similar clinical presentation and outcome to previous studies in Western countries. ADEM can occasionally evolve to multiple sclerosis in Thai children as being shown in previous reports from other Asian countries.     

Nasopharyngeal Carriage of Penicillin-Resistant Streptococcus pneumoniae among Children with Acute Respiratory Tract Infections in Thailand: a Molecular Epidemiological Survey

The prevalence of penicillin-resistant Streptococcus pneumoniae in Thailand has dramatically increased over the last decade. During a national survey, which was conducted from 1992 to 1994, 37.2% of the pneumococci isolated from the nasopharynges of children with acute respiratory tract infections were penicillin resistant (MIC, >/=0.1 microg/ml). In order to investigate the prevalence and clonal relatedness of nasopharyngeal carriage of penicillin-resistant S. pneumoniae in Thailand, a molecular epidemiological survey was undertaken. To this end, 53 penicillin-resistant pneumococcal isolates from children who suffered from acute respiratory tract infections and who originated from five distinct regions of the country were characterized in detail. DNA fingerprint analysis demonstrated 13 clusters, i.e., genotypes shared by two or more strains, and 14 unique genotypes. The cluster size varied from 2 (nine clusters) to 11 strains (one cluster). Six of the 13 restriction fragment end labeling clusters consisted of two or more distinct serotypes, indicating frequent horizontal transfer of capsular genes. Geographical distribution of the genotypes among the five regions of Thailand demonstrated that only four genetic clusters were restricted to single areas of the country, whereas the other nine clusters represented isolates collected in two or more districts. These observations demonstrate that the majority of the genetic clusters are spread throughout the country. The most predominant genetic cluster, representing 21% of the isolates, was identical to the Spanish pandemic clone 23F. In addition, the second largest cluster matched the Spanish-French international clone 9V. These data indicate that the genetic clones 23F and 9V, which are widely spread throughout the world, are the most predominant multidrug-resistant pneumococcal clones in Thailand. Therefore, we conclude that these pandemic clones are primarily responsible for the increase in the prevalence of pneumococcal penicillin resistance in Thailand.     

Prevalence and prognostic significance of COX-2 expression in stage IB cervical cancer

OBJECTIVES: To evaluate the prevalence of cyclooxygenase-2 (COX-2), correlation with various clinicopathologic factors and prognostic significance of COX-2 in stage IB cervical cancer patients. METHODS: 89 paraffin-embedded specimens of patients with stage IB cervical cancer underwent radical hysterectomy and pelvic lymphadenectomy at King Chulalongkorn Memorial Hospital during 1 January 1997-31 December 2002 and were stained with polyclonal goat antiserum against COX-2 using immunohistochemical method. Medical records were reviewed; clinicopathological variables were retrieved and used for analysis. RESULTS: The prevalence of positive COX-2 expression in stage IB cervical cancer in this study was 49.4%. Positive COX-2 expression in cervical adenocarcinoma was higher than squamous cell carcinoma (86.7% versus 40.6%, P < 0.05) and significantly expressed when lymph node metastasis was presented (100% versus 46.4%, P < 0.05). However, COX-2 expression was possibly associated with parametrial involvement (80% versus 47.6%, P > 0.05). There was no correlation between COX-2 expression and patient's age, tumor size, depth of stromal invasion and lymphovascular space invasion. Five-year disease free survival and 5-year overall survival in patients with positive COX-2 expression were 81% and 98% which were not differed from patients with negative COX-2 expression (92% and 95%, P > 0.05). CONCLUSIONS: Strong correlation was found in cervical adenocarcinoma and lymph node metastasis. However, COX-2 expression failed to demonstrate as a significant prognostic factor in stage IB cervical cancer.     

FRY site‐specific methylation differentiates pancreatic ductal adenocarcinoma from other adenocarcinomas

Adenocarcinoma is a type of cancer that occurs in the glandular cells throughout the body. There are several metastatic adenocarcinoma of unknown primary origin. Currently, there is no highly effective method to differentiate pancreatic ductal adenocarcinoma (PDAC) from other adenocarcinomas. Here, we identified pancreas tissue by site‐specific methylation at FRY and found that it can also detect PDAC. The establishment of Combined Bisulphite Restriction Analysis (COBRA) and quantitative real‐time PCR techniques of FRY revealed FRY hypermethylation in 21 out of 24 normal pancreatic tissue samples, whereas all other normal tissue samples from thirteen other organs (80 samples) remained totally unmethylated. Similarly in application to PDAC, this marker effectively indicated 25 PDAC among 151 other common adenocarcinomas with values of 100%, 98.7%, 92.6%, and 100% in sensitivity, specificity, positive predictive value and negative predictive value, respectively. In summary, we have demonstrated that this epigenetic site‐specific marker has high potential for pancreatic tissue identification and can be applied in PDAC diagnosis.     

Serotype distribution and antimicrobial susceptibility of S. pneumoniae causing invasive disease in Thai children younger than 5 years old, 2000-2005

In order to predict the potential benefit of pneumococcal conjugate vaccines (PCV), we evaluated the serotype coverage of the 7-, 9-, 11- and 13-valent PCV over the isolates causing invasive pneumococcal disease (IPD) in Thai children. One hundred and fifteen Streptococcus pneumoniae isolates from sterile sites in children younger than 5 years old between 2000 and 2005 were serotyped. The coverages of 7-, 9-, 11-, and 13-valent PCV were 69%, 73.8%, 73.8% and 85.7% in children younger than 2 years, and 73.9%, 77.4%, 77.4% and 87.8% in children younger than 5 years of age, respectively. 69.6% and 22.6% of the isolates were non-susceptible to penicillin and cefotaxime. 7-valent PCV covered 89% and 100% of penicillin and cefotaxime non-susceptible isolates.     

Detection and differentiation of filarial parasites by universal primers and polymerase chain reaction-restriction fragment length polymorphism analysis

Filarial nematode parasites are a serious cause of morbidity in humans and animals. Identification of filarial infection using traditional morphologic criteria can be difficult and lead to misdiagnosis. We report on a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based method to detect and differentiate a broad range of filarial species in a single PCR. The first internal transcribed spacer 1 (ITS1) along with the flanking 18S and 5.8S ribosomal DNA (rDNA) were isolated and cloned from Wuchereria bancrofti, Brugia malayi, and Brugia pahangi. Sequence analysis identified conserved sites in the 18S and 5.8S rDNA sequence that could be used as universal priming sites to generate ITS1-distinctive PCR products that were useful for distinguishing filariae at the genus level. The addition of a digestion of the ITS1 PCR product with the restriction endonuclease Ase I generated a fragment profile that allowed differentiation down to the species level for W. bancrofti, B. malayi, B. pahangi, Dirofilaria immitis, and D. repens. The PCR-RFLP of ITS1 rDNA will be useful in diagnosing and differentiating filarial parasites in human, animal reservoir hosts, and mosquito vectors in disease-endemic areas.     

Receptor-binding cancer antigen expressed on SiSo cells can be detected in metastatic lymph nodes from gastrointestinal cancers

AIM: To investigate the expression of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) in metastatic lymph nodes from gastrointestinal cancer. METHODS: Metastatic lymph nodes from gastrointestinal cancer were detected for RCAS1 by immunohistochemical staining and mRNA in situ hybridization. RESULTS: A total of 102 metastatic lymph nodes from bile duct, gastric, colon, and pancreatic cancer were investigated for RCAS1 expression. The immunoreactivity of RCAS1 was identified in 100% of metastatic lymph nodes. Both local and distant metastatic lymph nodes showed RCAS1 expression. On the contrary, specimens of non-cancerous lymph nodes were negative for RCAS1. The result of mRNA in situ hybridization was also confirmed by the finding of immunohistochemical staining, RCAS1 mRNA was detected in all tumor cells that metastasized to lymph nodes. CONCLUSION: All metastatic lymph nodes express RCAS1 in tumor cells at both protein and mRNA levels, and RCAS1 should be used as a complementary factor for identification of metastatic lymph nodes from gastrointestinal cancers.     

Migraine in junior high-school students: A prospective 3-academic-year cohort study

Migraine is a common childhood illness with expected favorable outcome. A study of the long-term clinical course of childhood migraine will provide information of evolution of migraine. A cohort study for 3-academic-year was conducted in Thai junior high-school children from July 2005 to February 2008 to determine the clinical course of migraine. Two hundred and forty-eight students in four junior high schools diagnosed with migraine according to ICHD-II in July 2005 were recruited. Each student was serially evaluated twice yearly from 7th grade during each semester of the academic year until the second semester of 9th grade. Determination of the characteristics, severity, frequency, and treatment of headache were obtained by questionnaire and direct interview. At the final evaluation, clinical course of headache was categorized into seven patterns. Among enrolled students, 209 (84.3%) completed the study. Twenty-eight (13.5%) students had no recurrent headache while that of 153 (73.5%) improved. No improvement of migraine and worsened migraine were observed in four students (1.8%) and 24 students (11.2%), respectively. Spontaneous remission and avoidance of precipitating causes contributed to relief of migraine in the majority of the students. Stress-related daily school activities and inadequate rest were reported as common precipitating factors among students with non-improving or worsening outcome. Chronic daily headache and tension-type headache was observed in 6 and 30 students, respectively. This study confirms that clinical course of migraine in schoolchildren is benign. Frequency and intensity of headache can be reduced with reassurance and appropriate guidance. Early recognition and appropriate prevention of migraine attack will decrease the risk of chronic migraine and disease burden.