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Biomedical subjects

W W Bond

Publications and source records attributed to W W Bond.

At least 55 records · Page 3Linked to original sources
PubMed1978

Evaluation of a finger prick blood collection method for the seroepidemiology of hepatitis B.

A finger prick-swab method of blood specimen collection was qualitatively and quantitatively compared with the conventional venipuncture method for HBsAg and anti-HBs determinations by radioimmunoassay (RIA). The new method consisted of pricking the finger, collecting 0.1-0.2 ml of blood with a cotton-wool swab, and eluting the swab in 1 ml of 1% bovine albumin in saline containing 0.1% sodium azide. Using chimpanzees seropositive for HBsAg or anti-HBs, comparisons were made of RIA results of: (a) whole blood, haemolysed blood, serum, and plasma; (b) paired finger prick samples and serum; (c) dilutions of finger prick samples and serum; and (d) different volumes of blood on swabs. Field studies were carried out at two institutions where hepatitis B was hyperendemic to compare results from paired finger prick and serum specimens assayed by the RIA and haemagglutination techniques. The laboratory studies showed that swab RIA values for anti-HBs were significantly lower than serum values and that for HBsAg, swab values were significantly higher than serum values. In HBsAg tests, the field studies showed 100% agreement between the two methods; in anti-HBs tests, the finger prick method showed 85% agreement with positive sera. Because of the logistics of collecting and processing blood serum, the finger prick-swab technique may be a valuable aid in large-scale seroepidemiological surveys for hepatitis B.

Antibodies, Viral↗
PubMed1977

Viral hepatitis B: aspects of environmental control.

In recent years it has become increasingly evident that viral hepatitis type B is a major disease problem among patients and/or health professionals associated with environments such as hemodialysis centers, dental operatories, clinical laboratories, and institutions for the mentally retarded. Studies have incriminated the intramural environment as well as specialized equipment and procedures as important factors in disease transmission. With hepatitis B surface antigen (HBsAg) as a marker of potentially infectious blood or body fluids such as saliva, it is possible to assess the environmental role in transmission of hepatitis B by use of a swab-rinse technique coupled with radioimmune assay. Assay procedures have been developed and utilized for detecting HBsAg on surfaces and in air and for quantitating of HBsAg in thermal and chemical inactivation studies. Specific decontamination strategies and recommendations for sterilization or disinfection procedures are described.

Cross Infection↗
PubMed1976

Hepatitis B surface antigen in saliva, impetiginous lesions, and the environment in two remote Alaskan villages.

A study was conducted in an area of hepatitis B hyperendemicity to determin whether contact with infective bodily secretions or contaminated environmental surfaces could be involved in the transmission of the hepatitis B virus. Hepatitis B surface antigen was detected in gingival swab, saliva, and impetiginous lesion exudate samples from children. Hepatitis B surface antigen also was found in swab samples of surfaces frequently touched or placed in the mouth. In the absence of classical exposure to infectious blood or blood products, these findings suggested that, in a crowded home environment, saliva and cutaneous exudates containing hepatitis B virus may play a role in the transmission of hepatitis B.

Alaska↗
PubMed1976

An air sampling technique for hepatitis B surface antigen.

A filter-rinse technique capable of detecting low levels of airborne hepatitis B surface antigen (HBsAg) was devised and evaluated. Laboratory tests showed the procedure to have an efficiency of 22% with a coefficient of variation of 11% and a capability of detecting as little as 5 x 10(-5) ml of aerosolized antigen positive serum in a single air sample. The technique was field-tested in a hemodialysis center serving a patient population with a high prevalence of HBsAg seropositivity. The antigen was not detected in any of 60 air samples collected under conditions favoring the occurrence of aerosols.

Aerosols↗
PubMed1975

Bacteriological evaluation of an ultra-pure water-distilling system.

A prototype distillation and storage system with recycle for producing ultrapure water was monitored for bacteriological contamination during a period of 24 months. Naturally occurring Pseudomonas aeruginosa and P. cepacia were found to grow rapidly to levels of about 10(5)/ml in water taken from the storage reservoir and also in commercially prepared distilled water. The system was found to eliminate bacterial contaminants introduced into the still with the feed water, but the reservoir, once contaminated, remained contaminated during prolonged recycle, After a single treatment with free chlorine, the entire system remained uncontaminated until accidental or purposeful shutdown.

Pseudomonas↗
PubMed1975

Microbial contamination of mist therapy units on six pediatric wards.

A study was conducted in six pediatric wards to investigated factors that influence microbial contamination of mist therapy units. Most samples from nebulizer reservoirs were positive for gram-negative bacilli which multiplied rapidly in distilled water and reached levels as high as 3.0 X 10(8) viable microorganisms per ml. High prevalence rates of Pseudomonas aeruginosa and coliform bacteria as well as high levels of gram-negative bacilli were found to be associated with infrequent and inadequate cleaning and disinfection of the nebulizing equipment. In one of the wards exhibiting high rates, a move to new quarters permitted the implementation of improved cleaning and maintenance procedures for mist therapy units. The result was a significant reduction of microbial contamination. This study reemphasizes the role of microbiological surveillance in assuring proper care of nebulizing equipment in the hospital.

Aerosols↗
PubMed1975

Gram-negative water bacteria in hemodialysis systems.

Gram-negative bacteria can multiply relatively fast in a variety of hospital associated fluids ranging from distilled, deionized, reverse osmosis, and softened water, which are normally considered devoid of nutrients, to intravenous solutions and fluids associated with hemodialysis. Excessive levels of these bacteria in the dialysate of artificial kidney machines can be responsible for pyrogenic reactions or sepsis or both.

Gram-Negative Aerobic Bacteria↗
PubMed1974

Thermoradiation inactivation of naturally occurring bacterial spores in soil.

Samples of soil collected from the Kennedy Space Center near the spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilzation techniques. The inactivation kinetics of the naturally occurring spores in soil were investigated by using dry heat and ionizing radiation, first separately and then simultaneously. Dry-heat inactivation kinetics of spores was determined at 105 and 125 C; radiation inactivation kinetics was determined for dose rates of 660 and 76 krads/h at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C, with a dose rate of 76 krads/h. Combined treatment was found to be highly synergistic, requiring greatly reduced radiation doses to accomplish sterilization of the population.

Cell Survival↗
PubMed1974

Factors that influence microbial contamination of fluids associated with hemodialysis machines.

Studies were conducted on the microbiological quality of fluids associated with different types of dialysis systems located in six dialysis centers and 14 homes. Included were (i) single-pass systems employing either parallel flow (Kiil or Gambro) or capillary cartridge dialyzers and (ii) recirculating single-pass and batch recirculating systems using coil dialyzers. Microbiological assays were performed on the water used to prepare dialysis fluid, the concentrated dialysate, and either pre- and postdialyzer dialysate (single-pass systems) or the dialysate contained in storage reservoirs and recirculating cannisters (recirculating systems). The levels of microbial contamination consisting of gram-negative bacteria were directly related to the type of dialysis system, method of water treatment, distribution system, and in some instances, the type of dialyzer. Recirculating single-pass and batch recirculating systems consistently contained significantly higher levels of contamination than single-pass systems. These results were directly related to the design of recirculating systems which permits carbon- and nitrogen-containing waste products dialyzed from the patient to accumulate, be used as nutrients by microorganisms, and subsequently allow for 2- to 4-log increases in contamination levels during a dialysis treatment. In contrast, levels of contamination in single-pass machines were related more to the quality of the water used to prepare dialysis fluid and the adequacy of cleaning and disinfection procedures than to the design of the system.

Acinetobacter↗
PubMed1973

Morphological, biochemical, and growth characteristics of pseudomonas cepacia from distilled water.

Studies were conducted on three strains of Pseudomonas cepacia isolated and maintained in distilled water and on a laboratory-subcultured strain transferred to distilled water. Optimum growth rates and maximum population yields of the four strains in distilled water were obtained at 37 C, although high population levels (10(6)-10(7)/ml) were reached and maintained over extended incubation periods at temperatures from 18 C to 42 C. Two strains were able to grow in distilled water at temperatures ranging from 12 C to 48 C and to survive 48 h and 21 days at 50 C and 10 C, respectively. Cells from distilled water cultures inoculated into Trypticase soy broth showed an immediate two- to three-log drop at upper and lower temperature limits; survivors were able to initiate logarithmic growth. Results obtained in morphological, biochemical, and antibiotic tests affirmed the strain differences noted in growth studies.

Aerobiosis↗
PubMed1973

Bacillus sp. ATCC 27380: a spore with extreme resistance to dry heat.

An unusual mesophilic Bacillus sp. was isolated from heated soil, and a cleaned spore preparation showed extraordinary resistance to dry heat (D(125C) = 139 h) and relative sensitivity to moist heat (D(80C) = 61 min). Biochemical tests and morphology fit no described species.

Bacillus↗
PubMed1972

Factors affecting comparative resistance of naturally occurring and subcultured Pseudomonas aeruginosa to disinfectants.

A strain of Pseudomonas aeruginosa was isolated in pure culture from the reservoir of a hospital mist therapy unit by an extinction-dilution technique; its natural distilled water environment was used as a growth and maintenance medium. After a single subculture on Trypticase soy agar, the strain showed a marked decrease in resistance to inactivation by acetic acid, glutaraldehyde, chlorine dioxide, and a quaternary ammonium compound when compared with naturally occurring cells grown in mist therapy unit water. The following factors were observed to affect the relative resistances of naturally occurring and subcultured cells of the P. aeruginosa strain: (i) temperature at which the cultures were incubated prior to exposure to disinfectants, (ii) growth phase of the cultures at the time of exposure to disinfectants, (iii) nature of the suspending menstruum for disinfectants, and (iv) exposure to fluorescent light during incubation of inocula prior to testing. The applied significance of these findings may alter the present concepts of disinfectant testing as well as routine control procedures in the hospital environment.

Acetates↗