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Biomedical subjects

J L Zimmer

Publications and source records attributed to J L Zimmer.

5 recordsLinked to original sources

Inactivation and potential repair of Cryptosporidium parvum following low- and medium-pressure ultraviolet irradiation.

This study investigated the level of inactivation and the potential for Cryptosporidium parvum to repair following low doses (1 and 3mJ/cm(2)) of ultraviolet (UV) irradiation from both low- and medium-pressure UV lamps. Cryptosporidium parvum oocysts suspended in phosphate buffered saline were exposed to UV using a bench-scale collimated beam apparatus. Oocyst suspensions were incubated at 5 degrees C or 25 degrees C under light and dark conditions up to 120 h (5 days) following exposure to UV irradiation, to examine photoreactivation and dark repair potential, respectively. Cryptosporidium parvum infectivity was determined throughout the incubation period using an HCT-8 cell culture and an antibody staining procedure for detection. No detectable evidence of repair was observed after incubation under light or dark conditions following either LP or MP UV lamp irradiation.

Animals↗

Potential repair of Escherichia coli DNA following exposure to UV radiation from both medium- and low-pressure UV sources used in drinking water treatment.

The increased use of UV radiation as a drinking water treatment technology has instigated studies of the repair potential of microorganisms following treatment. This study challenged the repair potential of an optimally grown nonpathogenic laboratory strain of Escherichia coli after UV radiation from low- and medium-pressure lamps. Samples were irradiated with doses of 5, 8, and 10 mJ/cm(2) from a low-pressure lamp and 3, 5, 8, and 10 mJ/cm(2) from a medium-pressure UV lamp housed in a bench-scale collimated beam apparatus. Following irradiation, samples were incubated at 37 degrees C under photoreactivating light or in the dark. Sample aliquots were analyzed for up to 4 h following incubation using a standard plate count. Results of this study showed that E. coli underwent photorepair following exposure to the low-pressure UV source, but no repair was detectable following exposure to the medium-pressure UV source at the initial doses examined. Minimal repair was eventually observed upon medium-pressure UV lamp exposure when doses were lowered to 3 mJ/cm(2). This study clearly indicates differences in repair potential under laboratory conditions between irradiation from low-pressure and medium-pressure UV sources of the type used in water treatment.

DNA Repair↗

Computers in family medicine. Automating outpatient medical practice.

The American Academy of Family Practice has been on a 4-year quest for a universal family practice office computer that it can recommend to its membership. Much as individual physicians struggle for computer "literacy," all medical organizations likewise face their own steep learning curve in the attempt to discern their memberships' needs and to provide guidance in meeting them.

Ambulatory Care↗

Chart reminders in the diagnosis of anemia.

We hypothesized that chart reminders would decrease the number of cases in which a low admission hemoglobin level was missed or ignored. Additionally, we compared the cost of generating the chart reminders by hand with the estimated cost of modifying the university hospital information system for this function. For three months, two medical students reviewed all abnormal hemoglobin results and assigned those more than 1 g below normal limits to a control or study group. A questionnaire, placed in all study group charts, requested an explanation for the low hemoglobin level. Eleven of 141 study cases and 16 of 150 control cases failed the audit criteria (differences not significant). The cost was $308 compared with $3,000 for altering the hospital information system. We conclude that chart reminders did not improve the detection of anemia and that it cost less to test this intervention by manually simulating the computer function.

Adult↗