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Biomedical subjects

A Gross

Publications and source records attributed to A Gross.

At least 199 records · Page 11Linked to original sources
PubMed1979

Effect of surgical scrub on microbial population under the fingernails.

The effectiveness of two methods of presurgical hand preparation, the 10 minute routine scrub and the 90 second Hydroscrub, in reducing microbial numbers under the fingernails was determined. Bacteriologic cultures of 162 subungual areas of nine subjects revealed prescrub microbial counts of up to 1.9 X 10(5) colony-forming units per area. After the surgical scrub, bacterial concentrations were reduced to a different degree among the persons tested. The mean values of 3.0 X 10(3) to 7.8 X 10(3) colony-forming units immediately after scrub indicated that neither of the two methods tested reduced the microbial population under the fingernails of most persons to acceptable levels. The finding of high postscrub microbial counts under the fingernails is of particular interest and significance in view of the relatively low counts on the fingertips. On the basis of the results of this study, we conclude that degerming of the areas under the fingernails by present methods is not satisfactory. The implication of these findings is discussed.

Anti-Infective Agents, Local↗
PubMed1979

Extent of bacterial contamination in a nonrebreathing inhalation sedation machine.

In this study the extent of bacterial contamination in a nonrebreathing inhalation sedation unit was determined. Bacteriologic cultures of different areas of the Quantiflex MDM machine were obtained during successive week-long courses in conscious sedation at this institute. Results of the bacteriologic cultures revealed the microbial contamination of nasal hoods before and after attempted disinfection with alcohol. The other areas of the unit were shown to be free of bacteria. Since attempted alcohol disinfection of nasal hoods was found to be ineffective, autoclave sterilization is recommended.

Anesthesia, Dental↗
PubMed1979

A new method of sterilization: the carbon dioxide laser.

The use of the carbon dioxide (CO2) laser for sterilization of metal instruments was investigated. Scalpal blades contaminated with bacterial spores were exposed to the laser and subsequently cultured. Our results demonstrate that the CO2 laser effectively sterilizes metal instruments.

Carbon Dioxide↗
PubMed1979

Comparison of Minitek and conventional methods for the biochemical characterization of oral streptococci.

Fifty-six strains of viridans streptococci were tested in the Minitek system (BBL Microbiology Systems, Cockeysville, Md.), and the results were compared with those obtained by conventional methods. An overall agreement of 98.9% was obtained when the Minitek tests were performed as follows. (i) All disks were incubated anaerobically for 48 h except for esculin and arginine, which required 5 to 7 days. (ii) The arginine disks were overlaid with 0.1 ml of sterile mineral oil even though incubated anaerobically. (iii) The Voges-Proskauer tests were performed under aerobic and anaerobic conditions. (iv) All tests for carbohydrate fermentation except for raffinose and salicin were read after the addition of 2 to 3 drops of 0.025% phenol red (pH 7.2). Of all the tests performed, only the fermentation of starch resulted in such poor agreement as to be considered unreliable. Results for inulin (unavailable in the Minitek system) were obtained by conventional methods.

Arginine↗
PubMed1978

[The tensile strength of human zonule and its alteration with age (author's transl)].

A series of 91 cryoextractions was performed on autopsy material. The scleral section was placed near to the chamber angle and was nearly circumferential (about 330 degrees). Cornea and adjacent sclera could be flapped over this way, and did not interfere with a straightforward lens extraction. The pupil was medically dilated. A cryoprobe was fixed to a specially constructed scale, and frozen to the anterior pole of the lens. Its weight was counterbalanced by a plastic water container at the other end of the scale. The extraction was performed by filling additional water into the counterbalancing container. The statistical evaluation of the results showed a very significant dependence of the average tensile strength on age. However, a considerable standard deviation was found throughout all ages. The nutritional state of the autopsy bodies and the time interval between death and start of the measurement had no significant influence. The differences between right and left eyes were also not significant, as could be expected. The methodological error remained small. Age proved to be an unreliable indicator for the tensile strength of the zonule. All results apply to clear lenses. We known from clinical experience that the tenacity of the zonule may also be different in the various types of cataract.

Adult↗
PubMed1978

A method of decontamination of ultrasonic scalers and high speed handpieces.

The use of contaminated water in high speed handpieces and ultrasonic handpieces presents potential hazards to both dentist and patient. This study has shown that after waterline sterilization, the use of a sterile, disposable membrane filter can eliminate the microflora from the water of an ultrasonic scaler for up to 48 hours. Similarly, the water from a high speed handpiece can remain bacteria free for up to 72 hours when a 0.45 micrometer pore size membrane filter is installed into the waterline. This system of decontamination by filtration may present a workable approach to the problem of contaminated water and merits further research and development. Commercial materials and equipment are identified in this report to specify the investigative procedures. Such identification does not simply recommendation or endorsement or that the materials and equipment are necessarily the best available for the purpose. Furthermore, the opinions expressed herein are those of the authors and are not to be construed as those of the Army Medical Department.

Bacteria↗
PubMed1978

The incidence of transient bacteremia during periodontal dressing change.

Twenty patients undergoing treatment for periodontal disease and not receiving antibiotics, volunteered to donate blood for culture studies to determine the incidence of transient bateremia during the dressing change and suture removal 1 week after periodontal surgery. Each patient contributed 20 ml of blood prior to the dressing change and an additional 20 ml during suture removal. The samples were cultured both aerobically and anaerobically. Bacteria were demonstrated in five out of 20 postoperative cultures (25%). This incidence approached statistical significance at the 0.05 level using Chi-square analysis with a Yates correction. All species were identified as belonging to the genus streptococcus. None of the blood specimens obtained prior to dressing change exhibited bacterial growth. Although the incidence of bacteremia in this study was not statistically significant at the 0.05 level, it may be clinically significant that five out of 20 patients demonstrated transient bacteremia. Commercial materials and equipment are identified in this report to specify the investigative procedures. Such identification does not imply recommendation or endorsement or that the materials and equipment are necessarily the best available for the purpose. Furthermore, the opinions expressed herein are those of the author and are not to be construed as those of the Army Medical Department.

Bacteria↗
PubMed1978

A rapid method for the presurgical cleansing of hands.

A new rapid method of presurgical cleansing of the hands has been evaluated in a clinical setting. The effectiveness of a 90 second jet wash has been compared with a standard 10-minute presurgical scrub. Bacteriologic cultures were obtained from the fingertips of interns, residents, and staff of the Department of Obstetrics and Gynecology of the Walter Reed Army Medical Center before and after 90-second jet washings and 10-minute conventional scrubs. The results showed that the 90-second jet wash was more effective in degerming the hands than the 10-minute standard brush scrub. Other advantages of the new method, such as the amount of time saved, the standardization of cleansing, and reduced skin irritation are discussed.

Antisepsis↗
PubMed1977

[Clinical and pharmacologic aspects of various betamethasone crystalline suspensions].

The commercially available betamethasone suspensions for injection used in this study have clearly shown quantitative differences in the combination of their easily hydrosoluble betamethasone esters and those difficult to dissolve in water, as well as in the shapes and sizes of their crystals. With regard to their influence on the endogenous cortisol production the two preparations have shown a highly deviating pharmaco-dynamic duration of action-corresponding to their different galenic composition (betamethasone phosphate/acetate approx. 7-8 days; betamethasone phosphate/dipropionate approx. 16-18 days). During the phase of suppression the reduced endogenous cortisol is largely compensated by the pharmaco-dynamic activity of the exogenous steroid.

Adolescent↗
PubMed1977

Effect of SnF2 mouthrinse on initial bacterial colonization of tooth enamel.

Microbiologic quantitative methods and scanning electron microscopy were used to observe the effect of stannous fluoride (100 ppm F-) mouthrinse on early plaque formation. An in vivo plaque model system was used on two individuals to test this experimental agent. Following SnF2 mouthrinsing, the total bacterial counts of two-day-old plaque on enamel cylinders were reduced up to 50.8 times or 98% and the streptococcal counts were decreased up to 48.4 times or 97.9%. Scanning electron microscopy confirmed a marked decrease of bacteria on enamel with use of SnF2 mouthrinse. It appears that, in addition to reducing enamel solubility and other properties, SnF2 may also alter bacterial accumulations on teeth.

Bacteria↗