An extensive study of human IgE cross-reactivity of Blo t 5 and Der p 5

BACKGROUND: Dual sensitization by Blomia tropicalis and Dermatophagoides pteronyssinus mites is common in tropical and subtropical countries. The human IgE cross-reactivity between clinical important group 5 allergens, Blo t 5 and Der p 5, remains controversial. OBJECTIVE: This study was undertaken to assess the levels of the IgE cross-reactivity between Blo t 5 and Der p 5 by using sera from a large cohort of asthmatic children in subtropical and tropical countries. METHODS: Purified recombinant Blo t 5 and Der p 5 were produced in Pichia pastoris and tested against sera from 195 asthmatic children. The IgE cross-reactivity was examined by direct, inhibitory and competitive human IgE enzyme-linked immunosorbent assay as well as skin prick tests. RESULTS: The Blo t 5 IgE responses were 91.8% (134 of 146) and 73.5% (36 of 49) for Taiwanese and Malaysian sera, respectively. The Blo t 5 specific IgE titers were significantly higher than those of Der p 5 (P <.02). The correlation of IgE reactivity between Blo t 5 and Der p 5 was low, and only limited cross-reactivity was observed. This was further confirmed by the dose-response inhibition studies. Skin prick tests performed on asthmatic children in Thailand also showed differential IgE response to Blo t 5 and Der p 5. CONCLUSION: By using a large panel of asthmatic sera and a combination of in vitro and in vivo assays, the major allergen of B tropicalis in tropical and subtropical regions, Blo t 5, exhibits low levels of IgE cross-reactivity with homologous Der p 5. These findings suggest that highly specific clinical reagents are necessary for precise diagnosis and immunotherapeutic treatment of sensitization to group 5 mite allergens.     

Prevalence of food allergy among preschool children in northern Thailand

Background: The epidemiology and clinical spectrum of food allergies (FA) confirmed by oral food challenge tests (OFC) in the Southeast Asian countries are limited. The aim of the present study was to examine the prevalence and characteristics of FA among preschool children in northern Thailand. Methods: Five hundred and forty‐six children aged 3–7 years living in Chiang Mai, Thailand participated in this study. A cross‐sectional parent questionnaire survey was conducted. Families with children reporting FA were invited to undergo further investigations with skin prick testing, serum specific IgE, and OFC. Results: A total of 452 out of 546 questionnaires (82.8%) were returned. Forty‐two children (9.3%) were reported to have FA. The five leading allergic foods reported were shrimp, cow's milk, fish, chicken eggs, and ant eggs. The most commonly reported symptom was a skin rash (78.0%), followed by abdominal pain and vomiting (31.1%). Anaphylaxis was found in two children (3.4%), from ant eggs allergy. Eighteen children underwent OFC; five of them were positive to shrimp, fish, and crab. Either skin prick test or serum‐specific IgE was positive in these children. Factors associated with parent‐reported FA included personal and family history of atopic dermatitis. Conclusions: The prevalence of IgE‐mediated FA confirmed on OFC was ≥1.11% (95% confidence interval: 0.41–2.98%). The most common causative food was shrimp. Ant eggs were a unique food allergen causing severe reactions in preschool children in northern Thailand.     

Gemcitabine plus cisplatin (GC): a salvage regimen for advanced breast cancer patients who have failed anthracycline and/or taxane therapy

BACKGROUND: In clinical studies of both heavily and minimally pretreated patients with advanced breast cancer, the combination of Gemcitabine plus cisplatin (GC), given in a variety of schedules and doses, has demonstrated moderate safety and efficacy in both heavily and minimally pretreated advanced breast cancer with response rate from 29-63% (median 46%). METHODS: We evaluated the activity and toxicity of another GC regimen (gemcitabine 1,000 mg/m(2) days 1, 8 plus cisplatin 75 mg/m(2) day 1 every 3 weeks) in 30 breast cancer patients who failed chemotherapy with anthracycline and/or taxanes as adjuvant or neoadjuvant, or primary therapy. RESULTS: We obtained overall response in 15 of 29 evaluable patients (52%), with responses occurring in all subgroups of disease (unresectable locally advanced, locoregional recurrence, and distant metastasis). Toxicity was primarily hematologic, with grade 3/4 neutropenia and thrombocytopenia in 37% and 17% of patients, respectively. The only grade 3/4 non-hematologic toxicity was grade 3 nausea/vomiting in 12% of patients. CONCLUSION: Our data suggest that gemcitabine plus cisplatin appears to be effective and has an acceptable toxicity profile in anthracycline and/or taxane pretreated patients with advanced breast cancer.     

House dust mite allergen levels in Chiang Mai homes

The quantitative assays for house dust mite (HDM) allergens provide a valid index of exposure and can be used for risk evaluation. We assessed group I HDM allergen levels in mattress and living room floor dust from 35 Chiang Mai homes and identified factors associated with high allergen levels. One-third of mattress and living room floor dust had group I HDM allergen levels of between 2-10 microg/g. Two-thirds of mattress dust and a small amount of living room floor dust had group I HDM allergen levels of over 10 microg/g. The geometric means of Der p I, Der f I and total group I allergens in mattress and living room floor dust were 8.61, 2.88, and 15.81 microg/g and 1.61, 0.27 and 2.43 microg/g, respectively. Mattresses made of kapok and rugs kept in the living room were associated with high group I allergen levels.     

Differential effects of heat stress on fibre capillarisation in tenotomised soleus and plantaris muscles

Purpose: Capillary regression is commonly observed in response to disuse muscle atrophy. Heat stress is known to alleviate muscle atrophy, while effect of heat exposure on capillary adaptation following disuse atrophy is not defined. Here, we examined the effect of heat treatment on capillarisation and the associated signalling in slow-oxidative soleus and fast-glycolytic plantaris muscles following Achilles tendon ablation (tenotomy).

Materials and methods: Male Wistar rats were assigned into control (CON), control with heat stress (CON?+?HEAT), tenotomy (TEN) and tenotomy with heat stress (TEN?+?HEAT) groups. Tenotomy was induced for 8?days in TEN and TEN?+?HEAT groups. Heat stress was maintained at 40.5–41.5?°C, 30?min for 7?days.

Results: Tenotomy resulted in reduction of capillary-to-fibre ratio, decreased VEGFR-2 and increased TSP-1 in soleus muscle, whereas VEGF protein expression remained unaffected. Tenotomy had no effect on capillary distribution and angiogenic signalling in plantaris muscle. These results were concomitant with larger reduction of cross-sectional area (CSA) in MHC type I and II myofibres of soleus compared to plantaris muscles. Interestingly, heat stress increased VEGFR-2 and attenuated TSP-1 protein expression in tenotomised soleus, but not plantaris muscles. Additionally, CSA of both type I and type II myofibres was greater in tenotomised soleus than plantaris muscles after heat treatment.

Conclusions: Heat stress mitigated effect of tenotomy-induced capillary regression in a fibre-type-specific response, in part, by shifting the balance between angiogenic and angiostatic regulators. These results suggest beneficial effect of heat treatment for maintaining microcirculation in disuse muscle atrophy.     

Time Trends of the Prevalence of Asthma, Rhinitis and Eczema in Thai Children-ISAAC (International Study of Asthma and Allergies in Childhood) Phase Three

Using the same questionnaire as in ISAAC Phase One study conducted in 1995, the ISAAC Phase Three was carried out in Bangkok and Chiang Mai, Thailand, in 2001, among children aged 6-7 and 13-14 years. There was an increase in the prevalence of the three diseases in the younger age group, i.e., current asthma, rhinitis, rhinoconjunctivitis, and flexural eczema. In the older age group, the prevalence of rhinitis and rhinoconjunctivitis increased. There was no change of prevalence of asthma in Bangkok, but prevalence decreased in Chiang Mai. Prevalence of eczema in older children increased in Bangkok, but remained the same in Chiang Mai.     

Comparative study of the pharmacokinetic characteristics of slow release theophylline oral preparations in Thai children with persistent asthma

Significant differences in the rate and extent of absorption exist between slow release theophylline (SRT) preparations. The pharmacokinetic characteristics of Xanthium were compared with those of Theo-Dur in twelve Thai children with stable persistent asthma by randomized, double blind, crossover study. Serum theophylline concentrations (STCs) were determined by fluorescence polarization immunoassay. The pharmacokinetic parameters were estimated by using a computer program (Topfit 2.0). The STCs, at steady state after different doses, were predicted by using the modified Wagner-Nelson Equation. The mean resident time (MRT) and apparent T1/2 were significantly larger for Xanthium, but the Cmax and AUC0-infinity of Xanthium were significantly lower than those of Theo-Dur. The Frel of Xanthium was 80.1% relative to Theo-Dur. The appropriate dosing interval of both preparations for Thai children was twice a day.