Role of Der p 1–specific B cells in immune tolerance during 2 years of house dust mite–specific immunotherapy

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Cost savings by reagent reduction in flow cytometry-based CD4+ T cell counts: an approach to improve accessibility for HIV management

In Thailand, the cost of antiretrovirals has recently been reduced more than 10 fold. Likewise strategies for a cost reduction in laboratory monitoring are warranted. This study was designed to explore if the most expensive reagent in flow cytometry based CD4+ cell monitoring, the CD4+/CD8+ monoclonal antibodies, can be reduced without a loss of accuracy. Blood samples from 55 HIV seronegative (HIV-) and 76 HIV+ subjects were analyzed for %CD4+ and %CD8+ T cells using a two color monoclonal antibody panel (BD Biosciences, CA, USA) with 3 different amounts of the recommended reagents for staining: 1) standard, 2) half, and 3) one-fourth. A significant Spearman correlation of 0.987 was shown for the % CD4+ T cell test results for one half as well as one-fourth of the recommended amount compared to the standard staining according to the manufacturer's instruction (p < 0.0001). For the % CD8+ T cell test results, the correlation between the standard and the half or one-fourth reduced staining was 0.972 (p < 0.0001). Bland-Altman analysis showed no significant bias between the results from one half or one-fourth of the recommended amount versus the standard. The sensitivity and specificity of the two methods at the CD4+ T cell count cut-off of 200 cells/microl were 93% and 100%; and 96% and 99%, respectively. Our study indicates that a reduction of the reagents to half or one-fourth of the amount recommended by the manufacturer was still able to generate reliable results for CD4+ and CD8+ T cell counts. Such an approach will significantly reduce the cost of CD4+ monitoring for resource limited settings where a flow cytometer is available.     

Identification of Possible Virulence Marker from Campylobacter jejuni Isolates

A novel protein translocation system, the type-6 secretion system (T6SS), may play a role in virulence of Campylobacter jejuni. We investigated 181 C. jejuni isolates from humans, chickens, and environmental sources in Vietnam, Thailand, Pakistan, and the United Kingdom for T6SS. The marker was most prevalent in human and chicken isolates from Vietnam.     

Single-dose therapy for giardiasis in school-age children

A randomized controlled trial was carried out to study the efficacy of combined albendazole and praziquantel in the treatment of giardiasis in school-age children. Eighty-four children were randomly allocated to 3 groups: group 1 (n = 31) albendazole 400 mg combined with praziquantel 20 mg/kg; group 2 (n = 26) albendazole 800 mg as a single dose; group 3 (n = 27) tinidazole 50 mg/kg as a single dose. The treatment was considered curative when Giardia was not found in two consecutive stool samples. The parasitological cure rate was 74.2% for combined single-dose albendazole-praziquantel, 50% and 92.6% in the albendazole and tinidazole groups respectively (p = 0.0023). There was no statistically significant difference between the cure rates of the combined regimen and tinidazole (p > 0.05). This combined regimen was considered safe, with only minor side-effects being observed. Of the single-dose regimens, tinidazole still achieves the highest parasitological cure rate for giardiasis. The albendazole-praziquantel combined regimen may be an alternative single-dose therapy for giardiasis in children, especially as this combination will eradicate common intestinal protozoa and co-existing helminths. Whether the dosage of this combination treatment should be adjusted for G. intestinalis remains to be established by further study.     

Incidence and clinical manifestations of influenza in nurse assistant students

A prospective study was conducted to find the incidence and clinical manifestations of influenza in 201 nurse assistant students of Faculty of Tropical Medicine during June 1998 to May 1999. There were 106 episodes of influenza-like illness (incidence 52.7%) of which only 33% were proven to be influenza (incidence 17.4%). Main clinical manifestations of influenza included headache, fever, malaise, myalgia, rhinorrhea, cough, and sore throat. We found that influenza could not be diagnosed solely by using clinical manifestations. Respiratory pathogenic bacteria were rarely isolated in patients with influenza-like illness and this led to our suggestion that routine pharyngeal culture and antibiotic therapy would not be helpful. Influenza vaccination of every nurse assistant student would be beneficial.     

Safety and immunogenicity of a three dose regimen of two tetravalent live-attenuated dengue vaccines in five- to twelve-year-old Thai children

OBJECTIVE: The safety and immunogenicity of tetravalent live-attenuated dengue vaccines after a three dose vaccination series were evaluated in Thai children. METHOD: One hundred three healthy flavivirus-seronegative schoolchildren ages 5 to 12 years were randomized to receive either dengue vaccine containing 3, 2, 1 and 2 log10 of the 50% cell culture infective dose, respectively, of the live-attenuated dengue vaccine serotypes 1, 2, 3 and 4 per dose (F3212; n = 40) or 3, 3, 1 and 3 log10 of the 50% cell culture infective dose (F3313; n = 42) or purified Vero cell rabies vaccine (control group; n = 21) given in a two dose schedule (3 to 5 months apart). A third dose was administered 8 to 12 months after the second dose to 90 subjects. Safety and immunogenicity were evaluated within 28 days after each injection. RESULTS: No serious adverse event related to the vaccines occurred. Most children experienced mild to moderate fever, rash, headache and myalgia occurring within 12 days after Dose 1 and generally lasting 3 days or less. One subject in Group F3212 had a 1-week dengue-like fever. Reactogenicity was minimal after Doses 2 and 3. Transient mild variations in liver enzymes and hematologic indices were noted mainly after Dose 1. After the third dose 89% of the subjects in Group F3212 seroconverted (neutralizing antibody response, > or =10) to all four serotypes, and all children in Group F3313 seroconverted. CONCLUSION: This study demonstrates a moderate although improvable reactogenicity and high seroconversion rates against the four serotypes of dengue after a three dose schedule of tetravalent live-attenuated dengue vaccine in children.     

Chronic diarrhea and abnormal serum immunoglobulin levels: a case report

A 15-year-old Thai boy with multiple episodes of chronic diarrhea caused by giardiasis with hypogammaglobulin M and IgG4 subclass deficiency (but normal antibody response to rabies vaccine) is reported. Immune status follow-up is necessary for a definite diagnosis and proper management.     

Effects of a dietary modification on 2 h postprandial blood glucose in Thai population at risk of type 2 diabetes: An application of the Stages of Change Model

The purpose of this study was to investigate the effect of a dietary modification intervention programme by applying the Stages of Change Model in 2 h postprandial capillary glucose reduction among Thai population. A randomized control trial was conducted for people at risk of type 2 diabetes for a period of 8 weeks. The intervention programme consisted of evaluating an individual's stage of change after being provided dietary information regarding kind of food and portions, discussion with a role model, and keeping a food diary record. By the end of the intervention programme, most participants in the experimental group were in the action stage (n = 36), whereas those in the control group were in the preparation stage (n = 32). Body mass index, blood pressure, food consumption behaviour and the 2 h postprandial blood glucose (PPG) in the experimental group had improved (P < 0.05). When performing regression analysis, intervention participation and the 2 h PPG at the baseline accounted for approximately 54% of total variance in predicting the 2 h PPG. This study yielded evidence for the benefits of using the Stages of Change Model as a framework in a dietary modification programme among people at risk of type 2 diabetes.