Biomedical subjects

N Margulies

Publications and source records attributed to N Margulies.

6 recordsLinked to original sources

PubMed1992

Effect of ultrasound on the neonatal rat brain.

Six-day-old rat neonates were exposed to 2.25 MHz continuous wave (CW) ultrasound for 5 min at an intensity of 2.5 W/cm2 (SATA). The temperatures on the head surface and in the mouth were measured. There was a higher average temperature elevation in the mouth (9 degrees C) than on the head surface (7 degrees C). Survival differs between control and exposed groups at 30 days after exposure. Ninety percent of the control group lived to 30 days, versus 59.7% for the exposed group. At differing times following exposure, the brains of the pups were removed and tested for enzymatic activities. Changes in acetylcholine esterase and in 2',3'-cyclic nucleotide phosphohydrolase activities were not statistically significantly different from controls. There were no significant differences in brain weight and total protein between control and exposed pups.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗

PubMed1991

Reversible biochemical changes in the developing rat central nervous system following ultrasound exposure.

Rat embryos in utero at 10 days of gestation (gd) were exposed to the intensity of 2.5 W/cm2 (SATA) of 1 MHz continuous-wave ultrasound for 5 min. The right uterine horn was exteriorized, exposed to the ultrasound beam, and then reinserted into the abdominal cavity. Embryos from the unexposed left uterine horn served as controls. The cerebral hemispheres of each fetus were removed and analyzed for enzymatic activity at four different stages of development. There was an increase in the temperature at the surface of the intact uterus during the ultrasound exposure. No gross anatomical malformations were observed in the exposed embryos. There were no differences in brain weight or protein content between exposed and control fetuses. However, the ultrasound exposure caused a transient decrease in acetylcholine esterase and 2',3'-cyclic nucleotide phosphohydrolase activities of the insonated fetal brains compared to the control brains. Because of the relatively high temporal-average intensity, the relatively large volume of tissue exposed, and the minimal sound path through tissue, the biochemical changes observed in this experiment would be unlikely to occur in clinical examinations.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed1990

Biochemical changes in the developing rat central nervous system due to hyperthermia.

Rat embryos at 10 days of gestation were exposed to 43 degrees C for 8 minutes by submerging the exteriorized right uterine horn in heated saline solution and then reinserting the uterine horn into the abdominal cavity. At 15 days, the fetuses were removed, and cells from the cerebral hemispheres were dissociated and grown as primary cultures. Embryos from the left uterine horn served as controls. No morphological changes were observed between the cultures of cells from control and heat-exposed embryos at different days in culture. However, exposure of embryos to hyperthermia at 10 days significantly affected the developmental pattern of activities of acetylcholine esterase associated with cholinergic neurons and of 2',3'-cyclic nucleotide phosphohydrolase associated with oligodendrocytes and myelin membrane formation. These results suggest that hyperthermia at 10 days of gestation in the rat may lead to an impairment in the development of neurons and oligodendrocytes in the central nervous system.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed1984

Productivity management: a model for participative management in health care organizations.

The current cost of inflation in the health care industry, contributed to in part by the Medicare and Medicaid legislation, has created concerns for productivity that can no longer be ignored by health care administrators. Despite these concerns and in the face of increasingly scarce resources, many hospitals have not yet established productivity tracking systems or methods for measuring and analyzing potential areas for productivity improvement.

California↗

PubMed1983

Motivating the client/employee system as a service production strategy.

Productivity improvement in service organizations is of major concern to managers as one way of countering escalating costs. In service organizations in which the client/customer is directly involved in the production function, improved performance can be secured by viewing the client/customer as a "partial" employee. This proposition in turn leads to the suggestion that productivity gains can be realized for services by expanding conventional motivation concepts to include the client/customer.

Efficiency↗

PubMed1977

Managing change in health care organizations.

The forces for change seem more potent today than ever before; increased technological advancement and rapid "societal upheavals" create a more critical need for change and a more significant need for skills to manage and channel change toward meaningful ends. The area of health care delivery is probably one of the fields most impinged upon and most affected by these turbulent times. Organizational development is presented herein as an approach to assist people in health care organizations with the problems of adaptation and change. A specific change strategy, action research, is discussed and a concrete case example is presented to illustrate the ways in which the action research model can be applied. Advantages and pitfalls are discussed in the concluding section.

Feedback↗