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Biomedical subjects

N G Lambert

Publications and source records attributed to N G Lambert.

13 recordsLinked to original sources

Evaluation of two hot water washer disinfectors for medical instruments.

Two models of hot water washer disinfectors (Decomat 128 and Hospital A, Euroclean Canada Inc; Ontario, Canada) were evaluated by two methods for their efficacy in disinfecting anesthesia equipment. In the first method, three different microbial suspensions were each sealed into 30 capillary tubes. In the second method, corrugated anesthesia tubes were rinsed with suspensions of each of two bacterial strains. The tubes then underwent a standard cycle in the hot water washer disinfectors and were subsequently tested for growth of microorganisms. All experiments were repeated three times, and the temperature was registered in all cases. In the capillary test, growth was rarely detected (13/540 tubes) and the inactivation factor for both apparatus was greater than 5 log10. In the rinse test, no growth was detected. The mean temperature for 15 disinfection cycles was 84.2 +/- 0.8 degrees C for Decomat 128 and 88.9 +/- 0.5 degrees C for Hospital A. However, for Decomat 128 we observed a variation of 3 degrees C from one disinfection cycle to another and a progressive reduction of 2.2 degrees C over a series of five consecutive complete cycles. Both methods gave reproducible results. Under our experimental conditions, both hot water washer disinfectors proved to be efficacious for the disinfection of reusable anesthesia equipment.

Anesthesiology

[An automatic bacteriophage distributor (author's transl)].

The apparatus described in this article can distribute simultaneously 22 drops of different phage suspensions at a rate of 13,200 drops per hour, which is superior than the one obtained with the presently available apparatuses. It could eventually be attached to a Petri dish distributor.

Bacteriophage Typing

Cytological effects of microwave radiation in Chinese hamster cells in vitro.

Cytological effects were investigated in the Chinese hamster cell line (CHO-K1) exposed to microwave radiation of 2450 MHz frequency and incident power of 25 to 200 W for a period of 30 min. Nuclear vacuoles, pycnotic and decondensed chromosomes were observed in cells exposed to 25 W under elevated temperature conditions (uncontrolled temp). In addition a significant increase in chromosomal breakages/cell was observed. Cells exposed to relatively higher power, 75-200 W, under hypothermic conditions (29 degrees C) revealed no significant increase in either nuclear vacuoles or other chromosomal anomalies over control cells. Radiation-induced temperature elevation appears to be an essential factor in the cytological effects of microwave.

Cell Line

[Study of the stability and the degradation of fluorescence in the immunofluorescence technic (FTA-ABS) using pulsed lasers].

The use of two pulsed lasers as excitation sources in the immunofluorescent technique FTA-ABS (fluorescent treponemal antibody absorption) shows that excitation of specimens by continuous or long-duration pulses of light (in the order of a millisecond) degrades the fluorescence in such a way that it is impossible to quantify exactly the fluorescent signal or repeat the analysis. Stability of fluorescence can be achieved by very short excitation pulses (in the order of a microsecond) and this fast fluorescent signal can be detected only by an electronic detection and recording system. With such a system, high precision is obtained by elimination of errors by the human eye.

Evaluation Studies as Topic

Use of tunable, pulsed dye laser for quantitative fluorescence in syphilis serology (FTA-ABS test).

A pulsed dye laser was used as an excitation source in a fluorescent treponemal antibody absorption (FTA-ABS) test. A high precision in quantitative fluorescence was obtained with this high-power excitation source coupled to an electronic detection system and a storage oscilloscope by standardization of fluorescence evaluation and through elimination of human error. One 0.4-mus pulse exposure was sufficient to record fluorescence intensity data on the oscilloscope. Absence of fading of fluorescence after repeated excitation permitted multiple readings of the same microscope field. Almost 100% reproducible results were obtained for the FTA-ABS test with 40 samples. Electronic detection of fluorescence and the high sensitivity obtained with laser excitation raise doubts about the relative value of quantitative immunofluorescence in the FTA-ABS test.

Antibodies, Bacterial

Color-coded antigen for the automated reagin test for syphilis.

A low-cost, color-coded antigen was developed for the Automated Reagin Test. A comparative study with 3,000 sera showed a sensitivity somewhat greater than the Rapid Plasma Reagin Card antigen. Samples could be traced back by using a specific color-coded antigen on a given autoanalyzer.

Antigens

[Attempted characterization of microorganisms by their metallic profiles].

Ten medically or environmentally significant strains of bacteria were assessed as to their metallic content (Be, Mg, Cr, Mn, Fe, Co, Cu, Zn, Cd and Pb). Metallic detection was performed using a carbon rod-equipped atomic absorption spectrophotometer. Experimental parameters such as heavy metal content of initial culture medium, incubation, "red fuming" nitric acid digestion times, evaporative losses (and their individual correction) plus primary sample dilutions, were standardized. For the ten strains studied, characteristic metallic profiles were observed. More work is needed to assess the taxonomic and epidemiologic significance of metallic profiles of microorganisms.

Bacteria