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Biomedical subjects

L Borgatta

Publications and source records attributed to L Borgatta.

25 records · Page 2Linked to original sources
PubMed1990

Biphasic effects of doxorubicin on the calcium release channel from sarcoplasmic reticulum of cardiac muscle.

To define the mechanism of doxorubicin cardiotoxicity, the effects of doxorubicin and caffeine were examined on calcium release channels from cardiac sarcoplasmic reticulum. We found that calcium release from cardiac sarcoplasmic reticulum vesicles was induced by both compounds. When sarcoplasmic reticulum vesicles were incorporated into planar lipid bilayers, calcium-permeable channels were observed. Addition of caffeine (2.5-10 mM) increased channel open probability from less than 0.1% to 40%, and this effect persisted for a mean of 44 minutes. In contrast, doxorubicin (2.5-10 microM) had a biphasic effect; initially, doxorubicin activated the channel, whereas after a mean of 8 minutes, the channel became irreversibly inhibited. Although the degree of channel activation by doxorubicin was concentration dependent, the time needed to inactivate the channel was concentration independent. Pretreatment with dithiothreitol (0.2 mM) prevented doxorubicin-induced channel inactivation, and channel activity persisted for an average of 58 minutes. Dithiothreitol alone did not alter channel open probability. Our results support the hypotheses that 1) the integrity of sulfhydryl groups is important for some aspects of calcium release channel function and 2) activation and inactivation of the channel are separable processes. The biphasic effect of doxorubicin on channel function may also correspond to the clinically observed adverse effects of doxorubicin, a widely used chemotherapeutic agent that, after prolonged usage, causes a dilated cardiomyopathy.

Animals↗
PubMed1990

Direct trocar insertion vs. Verres needle use for laparoscopic sterilization.

A randomized, prospective trial was designed to compare direct trocar insertion with prior peritoneal insufflation with a Verres needle for laparoscopic tubal sterilization. Direct trocar insertion resulted in fewer instrument insertions (21.8% vs. 7.8%) and use of smaller volumes of CO2 (2.67 vs. 2.32 L). Direct trocar use resulted in a decrease in operating time from 9 minutes, 40 seconds in the needle group to 7 minutes, 30 seconds in the trocar group. Minor omental injuries occurred in a small percentage of each group, while serious complications occurred once in each group.

Adult↗
PubMed1989

Association of episiotomy and delivery position with deep perineal laceration during spontaneous delivery in nulliparous women.

Spontaneous deliveries of 241 nulliparous women were analyzed to test the hypothesis that both episiotomy and use of stirrups for delivery of infants were related to the occurrence of third- and fourth-degree perineal lacerations. These deep perineal tears occurred in 0.9% of the women delivered of infants without the use of either episiotomy or stirrups and in 27.9% of the women delivered of infants with both episiotomy and stirrups. Women exposed to episiotomy alone or to stirrups alone had intermediate rates of laceration. There was no independent correlation of laceration with maternal age, 1- and 5-minute Apgar scores, or midwife or physician as delivery attendant. The results suggest that selective use of episiotomy and stirrups can minimize perineal trauma during spontaneous delivery in nulliparous women.

Adult↗
PubMed1989

Hand protection and protection from hands: hand-washing, germicides and gloves.

A variety of soaps, detergents, germicides, and protective gloves are available for use by health care workers. Appropriate hand-washing and glove use will reduce the possibility of spread of infectious organisms from patient to staff, from patient to patient, and from staff to patient. Both hand-washing and glove use can have adverse effects. Excessive hand-washing, mechanical irritation from scrubbing, use of germicides, and wearing of gloves can result in irritant and allergic dermatitis. Dermatitis will result in an increased risk of infection to both the worker and the patient.

Cross Infection↗
PubMed1988

Reliability and reproducibility of nonstress test readings.

The nonstress test is commonly used as a test of fetal well-being, despite the fact that both false-positive and false-negative results are known to occur. Although some of the errors are due to biologic variability among fetuses, some may be due to variability of reading the test. The purpose of the present study was to assess the reliability and reproducibility of nonstress test readings. Fifty nonstress test monitor strips were read by five perinatologists on two occasions, for a total of 500 readings. Nonstress tests were read as reactive, equivocal, nonreactive, or technically unsatisfactory. Of the 50 tracings, only 11 had identical readings on all 10 occasions, and readers had different readings for the first and second readings 28% of the time. Estimates of interobserver and intraobserver agreement ranged from 0.41 to 0.55. These results indicate that there is considerable interobserver and intraobserver variability that can be expected to have a serious adverse effect on the sensitivity of the nonstress test.

Female↗