The levels of cockroach allergen in relation to cockroach species and allergic diseases in Thai patients

Recently, cockroaches have been established as the second most Important allergen, producing allergic diseases, especially in low socioeconomic populations. In Thailand, about 44-61% of atopic patients were positive to cockroach extract by a skin-prick test. This study examined cockroach allergen levels in relation to cockroach species and allergic diseases in the houses of cockroach-sensitive patients. Sixty households of allergic patients in the Bangkok metropolitan area were surveyed using open- and closed-ended questionnaires. Cockroaches were collected using commercial cockroach traps, while dust samples were obtained from the bedrooms, kitchens and living rooms of the houses using a vacuum cleaner. The cockroaches were counted and their species Identified. The levels of cockroach allergens were determined by specific monoclonal antibodies using a monoclonal antibody-polyclonal antibody based sandwich ELISA kit. Six cockroach species were Identified: Periplaneta americana (American cockroach, 72.15%), Supella longlpalpa (2.75%, found in only one house), Periplaneta brunnea (0.78%), Periplaneta australaslae (0.78%), Neostylopyga rhombifolla (0.78%), Blattella germanica (German cockroach, 0.39%) and nymphs (22.35%). Allergens of the predominant species, P. americana, were detectable in all homes studied, with the highest levels in the kitchen areas. The range of allergen levels in house dust varied from 0.40-162.00 microg per g of dust. The median and mean allergen levels in kitchen dust were 59.16 microg and 62.80 microg per g of dust, respectively, while the median allergen level in bedroom dust was only 15.90 microg per g of dust. The German cockroach allergen (Bla g 2) was undetectable in any of the houses. IN CONCLUSION: P. americana was the most common cockroach and may be the species causing allergic diseases, especially asthma, in Thailand, which differs from the USA and Europe     

Medicinal parasitic plants on diverse hosts with their usages and barcodes

Medicinal properties of parasitic plants were investigated by means of ethnobotanical study in some areas of northeastern Thailand. Important traditional usages are: Scurrula atropurpurea nourishes blood, Dendrophthoe pentandra decreases high blood pressure, and Helixanthera parasitica treats liver disease. Their systematics were also determined. The research is based on findings obtained from 100 parasite–host pairs. Of these, eight parasitic species were recorded; they are members of two families, viz. family Loranthaceae, namely D. lanosa, D. pentandra, H. parasitica, Macrosolen brandisianus, M. cochinchinensis and S. atropurpurea, and family Viscaceae, namely Viscum articulatum and V. ovalifolium. In addition, each parasitic species is found on diverse hosts, indicating non-host-parasitic specificity. Species-specific tagging of all species studied was carried out using the rbcL and psbA-trnH chloroplast regions. These tag sequences are submitted to GenBank databases under accession numbers JN687563–JN687578. Genetic distances calculated from nucleotide variations in a couple of species of each genus, Dendrophthoe, Macrosolen, and Viscum, were 0.032, 0.067 and 0.036 in the rbcL region, and 0.269, 0.073 and 0.264 in the psbA-trnH spacer region, respectively. These variations will be used for further identification of incomplete plant parts or other forms such as capsule, powder, dried or chopped pieces.     

Mathematical Modeling of Crystallization Elution Fractionation of Ethylene/1‐Octene Copolymers

Crystallization elution fractionation (CEF) is a relatively new polyolefin characterization technique used to estimate the chemical composition distribution (CCD) of semicrystalline copolymers. CEF is developed to enhance the resolution and reduce the analysis time of temperature rising elution fractionation (TREF) by separating polymer samples in both the crystallization and elution steps. A model based on the concept of population balance, crystallization/dissolution kinetics, and dispersion model is developed to understand the CEF fractionation mechanisms. The proposed CEF model is found to describe well the experimental CEF profiles of a series of ethylene/1‐octene copolymers with different comonomer contents.

     

The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood

Objective

The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI.

Methods

A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97 ± 1.57 years (0.02–7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI.

Results

Of 67 children, 17 (25.4 %), 23 (34.3 %) and 20 (29.9 %) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and <0.001 in patients and at p values 0.024 and <0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I–III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV–V) had significant correlations with abnormal DMSA renal scintigraphy at p values <0.001 and <0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2 %) developed persistent renal scarring.

Conclusion

Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first episode of UTI should be carried out in those patients. Abnormal DMSA renal scintigraphy at 1 month after UTI has a tendency to persist.     

Antibacterial substances from Albizia myriophylla wood against cariogenic Streptococcus mutans

Albizia myriophylla has been used for long by Thai traditional healers as an important ingredient herb in Thai herbal formulas for caries. In this study, three flavonoids lupinifolin (6), 8-methoxy-7,3′,4′-trihydroxyflavone (7), and 7,8,3′,4′-tetrahydroxyflavone (8), a triterpenoid lupeol (3) as well as four sterols β-sitosterone (1), stigmasta-5,22-dien-3-one (2), β-sitosterol (4), and stigmasterol (5) were isolated from A. myriophylla wood. The antibacterial activity of these compounds against Streptococcus mutans ATCC 25175 was performed using broth microdilution method. All compounds exhibited antibacterial activity against S. mutans with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging from 1–256 and 2–256 μg/ml, respectively. Among the isolated compounds, lupinifolin (6) was found to be the most potent with MIC and MBC of 1 and 2 μg/ml, respectively. Lupinifolin (6) also showed a strong activity against ten clinical isolates of S. mutans with MIC and MBC ranging from 0.25–2 and 0.5–8 μg/ml, respectively. These results reported the bioactive ingredients of A. myriophylla which support its ethnomedical claims as well. Lupinifolin (6) may have a potential to be a natural anticariogenic agent.     

Impact of a filariasis control program on intestinal helminthic infections; a pilot study in Narathiwat Province, Thailand

This study was conducted in 9 villages located in endemic areas for brugian filariasis in Narathiwat Province, Thailand. Parasitological and anthropometric examinations were cross-sectionally performed to assess the prevalence of intestinal parasitic infections of 539 villagers. Paired stool samples were collected before and after mass treatment for the filariasis control program in 150 participants in order to study the impact of the filariasis control program on intestinal helminthiasis. The results found that 50.3% of the villagers were infected with one or more types of intestinal parasites. Double and triple infections were found in 10.9% and 1.6% of infected individuals respectively. The prevalence of intestinal parasitic infections peaked in the 1-10 year old age-group, which are pre-school and young school-age children. A significant reduction of intestinal helminthic infections in the post-treatment stool sample was observed in the 150 participants who were examined six months after mass treatment. Integrating an intestinal helminthic control program alongside the existing filariasis control program would be an appropriate and cost-effective strategy in the control of intestinal helminths. However, reinfection of parasites was observed.     

Determination of fecal occult blood in primary schoolchildren infected with Trichuris trichiura

A correlation of Trichuris trichiura infection and fecal occult blood detection was conducted in 146 primary schoolchildren in Narathiwat Province, Thailand. The Kato-Katz thick smear method was used for determining egg counts and stated as eggs per gram of feces (epg). The number of T. trichiura eggs was categorized as class I (1-499 epg), class 11 (500-4,999 epg), and class III (> 5,000 epg), according to the relation between infection intensity and reduced hemoglobin concentration. Each fecal sample was processed to detect occult blood using a guaiac-based test (Hema-Screen, USA) and an immunochromatographic-based test (HEXAGON OBTI test, Germany). There were 50 schoolchildren without parasitic infection in the control group. Of 96 cases with T. trichiura infection, 85 and 11 children were classified in the class I and class II groups, respectively, but no subjects were in the class III group. Positive occult blood detection results in the control, class I, and class II groups using the guaiac and the immunochemical tests were 0, 3.5, and 9.1% (p=0.19), and 0, 2.4, and 36.4%, (p<0.0001) respectively. This study suggests that T. trichiura infection with an intensity of 500 epg or greater may be associated with intestinal bleeding.     

Blastocystis hominis infection in irritable bowel syndrome patients

Irritable bowel syndrome (IBS) is a functional bowel disorder in which abdominal pain is associated with a defect or a change in bowel habits. Subtle inflammation, especially after infectious enteritis, has been sometimes suspected as one mechanism of pathogenesis. This research was performed (1) to evaluate the prevalence of parasitic infections and (2) the possible association of IBS and parasitic infections. Fifty-nine IBS patients were recruited using symptom-based criteria (Rome Criteria II) with an absence of intestinal parasitic infection by direct smear method. Stool samples of individual patients were examined using 7 methods, ie examination for stool occult blood, simple saline smear method, formalin-ether technique, culture for Blastocystis hominis, modified trichrome stain, modified Ziehl-Neelsen method, and trichrome stain for parasitic and bacterial infections. Of the 59 patients, stool samples of 13 patients (22.1%) were positive for parasites. These were B. hominis (13.6%), Strongyloides stercoralis larvae (1.7%), Giardia lamblia cysts (1.7%), and non-pathogenic protozoa, ie Endolimax nana cysts (5.1%). The prevalence rate of parasitic infections in the control group (20%) was not statistically different from the patients. There was no statistical difference between B. hominis infection in IBS patients and control was found in this study (p = 0.87). In the IBS group, B. hominis infection predominated (13.6%), while other parasitic infections were found in 8.5%. The culture method for B. hominis is more sensitive than the direct (simple) stool smear method, which is the routine diagnostic method in most laboratories. These results were also found in control group.     

Conversion to low-protein, powder-free surgical gloves: is it worth the cost?

This study was conducted to determine changes in overall costs associated with conversion to powder-free gloves including cost of workers' compensation cases for natural rubber latex (NRL)-related symptoms and health care workers' glove satisfaction. The study, a 2-year, longitudinal design with retrospective and prospective aspects, was developed to determine health care worker use of powder-free, low-protein NRL gloves, sensitization, cost, and glove satisfaction. Informed consent was obtained from 103 health care workers. Prior to glove conversion, nearly one-half (44%, 36 of 82) of the operating room staff reported symptoms related to NRL exposure. At the end of the 14-month data collection period, only 27% (22 of 82, McNemar test = .007) reported symptoms related to NRL exposure. Additionally, a cost savings of 10,000 dollars per year for gloves was evident with reports of increased user satisfaction. This study demonstrated that conversion to the use of powder-free, low-protein NRL gloves not only reduces health care worker NRL symptoms, but also positively affects the costs of glove purchases and workers' compensation.     

Chemical constituents and biological activities of Albizia myriophylla wood

Context: Albizia myriophylla Benth (Leguminosae) is a medicinal plant widely used in Thailand and other Asian countries as a folk medicine remedy for many ailments.

Objective: The objective of this study is to investigate the chemical compositions, antibacterial activity, and cytotoxicity of A. myriophylla wood.

Materials and methods: The structure identification of the isolated compounds was established using spectroscopic methods. In vitro antibacterial activity against Streptococcus mutans, Staphylococcus aureus, and Bacillus cereus and the cytotoxicity against KB cells of extracts and compounds from A. myriophylla were performed using broth microdilution and resazurin microplate assays, respectively. The lupinifolin content in A. myriophylla extracts was quantified by high-performance liquid chromatography.

Results: A rare flavan-3,4-diol (1) together with eight known compounds (2–9) were isolated from the wood of A. myriophylla. Compounds 4–9 exhibited anti-S. mutans activity, of which lupinifolin (5) was the most potent with an MIC value of 0.98?µg/mL, followed by its dihydroxy derivative 4 with an MIC value of 62.5?µg/mL. Compounds 4 and 5 also displayed marked antibacterial activity against B. cereus and S. aureus (MIC value 15.63–125?µg/mL) and showed strong cytotoxic activity against KB cells (IC₅₀ value 4.95–12.55?µg/mL). The lupinifolin contents in ethanol extracts from two different collections of this plant originating from central and southern Thailand were 93.85 and 0.04?mg/g, respectively.

Conclusion: This is the first report of compounds 1–4 from A. myriophylla. Compounds 4 and 5 showed potent antibacterial and cytotoxic activities compared with other isolates. The anti-S. mutans activity of A. myriophylla extracts seems to be related to the lupinifolin content.