Eradication of house dust mite from homes of atopic asthmatic subjects: a double-blind trial.

BACKGROUND: House dust mite (HDM) allergens can accumulate to very high levels in homes. From the observed sensitivity of HDMs to heat and their allergens to steam, a novel treatment of furnishings has been developed. OBJECTIVE: We sought to determine whether combined steam and heat treatment of home furnishings reduced asthmatic patients' bronchial hyperreactivity (BHR) and lowered HDM antigen loads. METHODS: The homes of 30 asthmatic subjects aged 18 to 45 years were randomly allocated into 3 groups. In groups 1 and 2 mattresses and duvets were treated with hot air (110 degrees C), followed by steam and then heat again. All their carpets were steam cleaned. Group 2 also had a special ventilation system installed above each patient's bedroom. The homes of subjects in group 3 were sham treated. Neither patient nor laboratory staff was aware of the types of treatment. Der p 1 and 2 levels in the household dust from the lounge, bedroom carpet, and beds were determined before and after treatment and then at 6 and 12 months. BHR, measured by using histamine PD(20) values, was recorded during the 4-week run-in period and at 3, 6, 9, 12 months after treatment. RESULTS: Active heat-steam treatment of homes caused a sustained reduction of Der p 1 (P =.003) and Der p 2 (P =.001) compared with no change in sham-treated group 3 homes. Patients whose homes were treated showed a 4-fold reduction in BHR at 9 months in group 1 and throughout the posttreatment period in group 2. No change was observed in the asthmatic subjects whose homes were not treated. These improvements were sustained for 12 months in the homes with bedroom ventilation units. CONCLUSIONS: A single treatment of home furnishings reduced mite allergen load to below the risk level for sensitization and improved the asthmatic patients' BHR by 4-fold.

A randomized trial of dehumidification in the control of house dust mite.

BACKGROUND: House dust mites (HDM) are sensitive to humidity. Few studies have adequately examined the potential of dehumidification in reducing HDM numbers. OBJECTIVE: The study examined the effect of portable domestic dehumidifiers, and a behavioural programme to reduce humidity, on HDM counts and HDM allergen levels. METHODS: A randomized controlled trial was undertaken. A total of 76 homes were allocated to three groups that received a portable domestic dehumidifier, a behavioural programme, or no intervention. Humidity, temperature, HDM counts (trap and vacuum samples), HDM allergen, and other details of the home environment were measured on four occasions over a period of 1 year. Interventions and measurements were concerned predominantly with one bedroom. RESULTS: There was a reduction in relative humidity in the dehumidifier group, but not the behavioural group. A decline in HDM trap counts was observed for all three groups. Change scores did not indicate that the dehumidifier group had a greater decline than the other groups. A secondary analysis examining presence or absence of HDM showed a shift from households having HDM at baseline to households not having HDM in the final round for some trap measures. Change score analysis indicated that this shift was greater in the dehumidifier group compared with other groups. The dehumidifier group did not show a greater decline in HDM allergen than that seen in the other two groups. CONCLUSION: Neither the dehumidifier nor the behavioural intervention had a major effect on HDM counts or allergen levels. However, the study did have a number of limitations relating to size, timing of intervention, and running of the dehumidifiers. The secondary data analysis may indicate some effect of dehumidification, but clearly this effect was small. There is a need for more information on the effects of reducing ambient humidity on the distribution of HDM within their habitats.

Envenoming by Chinese krait (Bungarus multicinctus) and banded krait (B. fasciatus) in Myanmar.

A retrospective study of 8 cases of envenoming by Chinese krait (Bungarus multicinctus) and one banded krait (B. fasciatus) in southern Myanmar is reported. Chinese krait bite produced minimal local reactions, except in one person bitten on the lip which resulted in local swelling. Onset of neurotoxic symptoms occurred 2.5-6 h after the bite, and the interval between bite and death ranged from 12-30 h. Three deaths were due to respiratory failure. Four mildly envenomed cases recovered spontaneously without assisted ventilation. One severely envenomed patient recovered after 8 d intensive respiratory care. Cobra (Naja kaouthia) antivenom had no value in reversing neurotoxic symptoms. Anticholinesterase injection given to one patient failed to improve neurotoxic symptoms. The bite of banded krait (B. fasciatus) resulted in neurotoxic envenoming within 2 h after the bite, with minimal local reactions. The victim died of respiratory failure 14 h after the bite.

Lysosomal enzyme activities in normals and in patients with chronic liver diseases.

The maximal activities of liver lysosomal enzymes (acid phosphatase and cathepsin D) were found to be increased in patients with chronic active hepatitis, cirrhosis and primary hepatocellular carcinoma. The ratio between maximal and basal activity (an expression of the degree of retention of the enzymes to lysosome) of acid phosphatase was significantly decreased in patients with chronic active hepatitis and cirrhosis whereas that of cathepsin D did not show any significant changes between normal and various liver disorders. Serum levels of both the enzymes were elevated significantly in patients with cirrhosis and primary hepatocellular carcinoma.

Endoscopic examination of the duodenal bulb: clinical evaluation of forward- and side-viewing fibreoptic systems in 200 cases.

Two-hundred fibreoptic examinations of the duodenal bulb were carried out on 149 patients. The importance of combining the initial examination with a general endoscopic survey of the oesophagus and stomach is stressed. At the present time full examination of the duodenal bulb requires the use of both a side-viewing and forward-viewing endoscope in more than a quarter of cases. The safety and acceptability to the patient of multiple endoscopic examinations carried out as an outpatient procedure has been demonstrated, and the value of the procedure in x-ray negative dyspepsia, in the follow up of ulcer therapy, and in acute upper gastrointestinal haemorrhage has been shown.