Biomedical subjects
Publications and source records attributed to J Setzer.
The authors present their experiences in assisting the government of Niger to develop automated information systems for health care management. They discuss the structure of the health system, the role of donor assistance, the process of initiating automated systems, and the technical requirements and costs of the system. Finally, they draw general conclusions that may be useful for those attempting similar efforts.
Subjects were tested for neurobehavioral performance in an environmental chamber to detect the presence of subclinical central nervous system effects from 4-hr exposures to methyl isobutyl ketone (MIBK) at 100 ppm, methyl ethyl ketone (MEK) at 200 ppm, MIBK at 50 ppm with MEK at 100 ppm, or a placebo (i.e., a 5-min presentation of 25 ppm MEK-MIBK at each exposure period outset). Subjects were 68 males and 75 females recruited from local universities; ages ranged from 18 to 32 years. Ethanol by ingestion (95%-0.84 ml/kg) was used as a positive control. Five psychomotor tests (choice reaction time [CRT], simple reaction time [SRT], visual vigilance, dual task [auditory tone discrimination and tracking], memory scanning), one sensorimotor test (postural sway), and a test of mood (profile of mood states) were used to measure neurobehavioral effects. Additionally, chemical measurements (blood and breath) and reports of sensory and irritant effects were measured. The chemical exposures produced statistically significant performance effects on only 4 of 32 measures (% correct responses-visual vigilance, movement time-CRT, SRT, % incorrect responses-dual task). These effects, however, were not substantial and could not be attributed directly to the chemical exposures. Alcohol ingestion, however, produced significant decrements on every performance test except memory scanning and mood. An interaction occurred between gender and alcohol ingestion, such that more statistically significant performance decrements were found for females than for males. Significant odor sensations and irritant effects were reported by the subjects during the chemical exposures. The MEK results agree with earlier MEK experiments at comparable exposure conditions, and the MIBK results are consistent with a recent Swedish study that used MIBK exposures and showed no significant behavioral performance decrements from single MIBK exposures at 50 ppm with 50 W exercise. Additionally, the MIBK-MEK combination exposure showed no evidence of any interaction effects on either the behavioral or chemical measurements. The principal effects resulting from exposures to MEK and MIBK at the durations and concentrations used in the study are limited to sensory and irritant effects.
The bacteriophage T4-induced alt and mod gene products covalently add ADP-ribose to the Escherichia coli RNA polymerase alpha polypeptides; phage carrying either an alt or a mod mutation are viable. A genetic cross between T4alt and T4mod phages yielded alt mod recombinant progeny which could not ADP ribosylate RNA polymerase at all, yet grew apparently normally. Thus, ADP ribosylation of RNA polymerase appeared to be nonessential for T4 development (at least in E. coli B/r and E. coli CR63), even though the phage has evolved two distinct enzymes to catalyze this reaction.
To investigate causes of the age-dependent increase of thromboembolic events, plasma coagulation parameters were determined in healthy elderly blood donors in comparison with young, and elderly diseased blood donors. Partial thromboplastin and thrombin clotting times were slightly shortened, whereas prothrombin and reptilase clotting times were unaltered. Plasma concentration of clotting factors like F I, VII, VIII: C, X, HMW-kininogen and prekallikrein were increased, whereas the coagulation inhibitor antithrombin III was decreased. Concerning fibrinolysis, plasminogen and alpha-2-antiplasmin were not affected by age, but plasminogen activators in the euglobulin fraction were lower. This shift in the pattern of coagulation factors favors enhanced fibrin formation and delayed fibrinolysis in the elderly. Higher intermediary products demonstrate that activation of coagulation and fibrinolysis happen more often in elderly healthy people. Together with blood stasis and vessel wall damage, this shift of the hemostatic balance contributes to a higher incidence of thromboembolic disorders in the aged.