Biomedical subjects

S B Wee

Publications and source records attributed to S B Wee.

22 records · Page 2Linked to original sources

PubMed1985

Antibody to human rotavirus in cow's milk.

Rotavirus infection is an important cause of gastroenteritis in infants and young children. Since the virus replicates in the intestinal lumen, we investigated the presence and effectiveness of rotavirus antibody in three forms of milk: raw milk, pasteurized milk, and commercially available infant formulas. Both raw and pasteurized milk contained detectable levels of IgG1 antibody directed at rotavirus. On the other hand, little or no anti-rotavirus antibody was detected in commercially available infant formulas or other sterile milk preparations. The milk samples with rotavirus antibody were capable of inhibiting the replication of simian, bovine, and human rotaviruses in tissue culture. In addition, they were capable of protecting mice from infection and disease in a murine model of rotavirus infection. On the other hand, the formula preparations were incapable of modifying the in vitro replication of rotavirus strains in tissue culture and did not prevent symptomatic gastroenteritis in the mouse model. We conclude that the alteration of milk-processing procedures or the addition of effective antibodies to milk preparations commonly used in the nutrition of young children may alter the clinical course of rotavirus infection or decrease the transmission of rotavirus throughout susceptible populations.

Animals↗

PubMed1984

The use of beta-lactamase in enzyme immunoassays for detection of microbial antigens.

The sensitivity and performance characteristics of enzyme immunoassays (EIA) depend to a great extent on the kinetics of the enzyme-substrate system used as indicator. We labeled a variety of polyclonal and monoclonal immunoglobulins with purified beta-lactamase and used them in sensitive EIA systems for the detection of a number of microbial antigens. Polyclonal antibodies to rotavirus, adenovirus, and Haemophilus influenzae type b polyribitol phosphate and monoclonal antibodies to dengue virus were labeled with beta-lactamase and used to provide sensitive direct EIA systems for the detection of the corresponding antigens. In addition, antibodies directed at animal immunoglobulins were labeled with beta-lactamase and used in indirect EIA for the detection of viral antigens with unlabeled anti-viral monoclonal and polyclonal antibodies. Similarly, avidin from Streptomyces was labeled with beta-lactamase and used to detect viral antigens tested for in an avidin-biotin format. Enzyme immunoassay systems with beta-lactamase-labeled antibodies were also used to detect rotaviral and adenoviral antigens in rectal swab specimens from children with acute gastroenteritis. The sensitivity of the beta-lactamase EIA compared favorably with that of analogous EIA systems using alkaline phosphatase or horseradish peroxidase. The results of a beta-lactamase EIA were easily determined by naked eye and a permanent record of the qualitative results obtained by the use of a standard office photocopier, obviating the need for an expensive colorimeter. Enzyme immunoassays using beta-lactamase have potential as practical assay systems for the detection of a wide range of microbial antigens using monoclonal and polyclonal antibodies.

Antigens, Bacterial↗

PubMed1984

Enzyme immunoassays in which biotinillated beta-lactamase is used for the detection of microbial antigens.

The performance characteristics of enzyme immunoassays are determined to a great extent by the enzyme-substrate system utilized for the immunoassay. Beta-lactamases (penicillin amido-beta-lactamhydrolase EC 3.5.2.6) offer a number of advantages which might make them useful in immunoassay systems. We linked beta-lactamase from Bacillus cereus with biotin and used the biotinillated enzyme to devise immunoassay systems for the detection of a number of microbial antigens. An assay system in which antibodies to the polyribitol phosphate antigen of Haemophilus influenzae type b were used was capable of detecting between 0.4 and 1.6 ng of that antigen. Similarly, an assay in which antibodies to the common antigens of adenoviruses and biotin-linked beta-lactamase were used was capable of detecting between 1 and 10 50% tissue culture infective doses of a strain of enteric-type adenovirus. When applied to the detection of rotavirus, a similar system in which biotinillated beta-lactamase was used was capable of detecting small amounts of antigen in a standard rotavirus preparation. This assay could also detect virus in 36 of 37 stool specimens from children with rotavirus gastroenteritis. The positive specimens could easily be distinguished from negative ones by the naked eye, and a permanent record of the qualitative results could be obtained by the use of a standard office photocopying machine. Beta-lactamases have promise for use in practical enzyme immunoassay systems, especially in situations in which expensive colorimetric instrumentation is not available.

Antigens, Bacterial↗

PubMedDate not supplied

An efficacy evaluation of a synergized glutaraldehyde-phenate solution in disinfecting respiratory therapy equipment contaminated during patient use.

Reusable, corrugated, expiratory limb ventilator tubing that had been in use for 24 hours, were randomly allocated to one of three groups: no treatment (N = 36); detergent wash (N = 83); or a detergent wash followed by a 10 minute immersion in a 1:16 dilution of synergized glutaraldehyde-phenate solution which was reused for 30 days. (Between 10 and 22 tubes were tested in each five day interval during this 30-day period.) Tubes were quantitatively and qualitatively cultured. There were significant differences in both the percent of contaminated tubes (no treatment = 92%, detergent wash = 72%, glutaraldehyde-phenate = 0 to 20%) and numbers of microorganisms per tube (no treatment = 3.2 x 10(6), detergent wash = 1.3 x 10(4), glutaraldehyde-phenate = 0 to 182) between groups. There was no apparent decrease in glutaraldehyde-phenate's efficacy throughout the 30-day reuse period, and in the final five days of the reuse period it was completely effective.

Aldehydes↗