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E Livingston

Publications and source records attributed to E Livingston.

28 records · Page 2Linked to original sources
PubMed1996

Why the Urgency for Earlier Diagnosis of HIV Infection in Women?

As our perspective of AIDS changes from a disease that affects homosexual men and intravenous drug abusers to one that spreads increasingly through heterosexual contact, greater numbers of women are being diagnosed with HIV infection. Because clinicians still may perceive AIDS to be primarily a "male" disease and may maintain a low level of suspicion of it in their female patients, HIV infection is believed to be underdiagnosed and go unrecognized for longer periods in women than in men. Early reports in the 1980s that showed a worse prognosis and shorter median survival for women than for men are now explained by factors such as later presentation and diagnosis, disparity in access to care, and reluctance of clinicians to prescribe zidovudine to pregnant patients. Recent studies show that, with early identification of infection and subsequent treatment and prophylactic therapy, there are no differences in disease progression or survival in women compared with men. Moreover, from a public health standpoint, earlier diagnosis can decrease incidence of both sexual and vertical transmission. Women may choose to undergo tubal ligation to prevent future vertical transmission; additionally, zidovudine now is used in pregnant women and has been demonstrated to decrease transmission rates from 25% to 8%

Journal Article↗
PubMed1995

A new preparation of nitroglycerin for uterine relaxation.

Emergent attainment of uterine relaxation is an occasional need in obstetric practice. Various agents, from amyl nitrate through volatile anesthetics have been used to relax the uterus, with varying degrees of success and side-effects. Recent publications report the use of intravenous nitroglycerin (NTG), with excellent results and few adverse side effects, but preparation for injection requires time and may produce error. We have used a new sublingual aerosol spray of NTG, at an initial dose of 0.8 mg, in 7 patients for rapid uterine relaxation and have not observed adverse side-effects. Prolonged shelf life, ready availability and ease of use make the sublingual spray attractive for urgent tocolysis.

Journal Article↗
PubMed1992

Thyrotropin-releasing hormone analog injected into the raphe pallidus and obscurus increases gastric contractility in rats.

The present study was performed to investigate the influence of the chemical stimulation of medullary raphe nuclei by the stable TRH (thyrotropin-releasing hormone) analog, RX 77368, on gastric contractility. Urethane-anesthetized rats were acutely implanted with miniature strain gauge force transducers on the corpus of the stomach for continuous recording of gastric contractility. Traces were analyzed by computer. Microinjections of vehicle or RX 77368 into the raphe pallidus or raphe obscurus were performed using pressure injection of 50 nl through glass micropipettes 30 min following basal recording of gastric contractility. RX 77368 (0.7-77 pmol) dose dependently stimulated gastric contractility when microinjected into the raphe pallidus and raphe obscurus. The stimulation of gastric contractions induced by microinjection of RX 77368 (77 pmol) into these raphe nuclei was completely blocked by vagotomy and prevented (raphe obscurus) or reduced (raphe pallidus) by atropine. RX 77368 (7.7-77 pmol) microinjected into the inferior olive, pyramidal tract, medial lemiscus was ineffective. These results demonstrate that chemical stimulation of the raphe pallidus and obscurus by RX 77368 stimulates gastric contractility through vagal and muscarinic pathways. These data suggest a role for medullary raphe nuclei in the central vagal regulation of gastric contractility.

Animals↗
PubMed1988

Gastric mucosal blood flow response to stimulation and inhibition of gastric acid secretion.

The effect of stimulation (with graded doses of intravenous pentagastrin) and inhibition (with an H2-blocker or a proton pump inhibitor) of acid secretion on corpus mucosal blood flow was investigated. Hydrogen gas clearance was used to measure blood flow in the basal portion of the mucosa of anesthetized rats. A dose-related increase in acid output increments above resting level was observed with the doses of pentagastrin from 0 (saline infusion) to 40 micrograms/kg.h. With the doses of pentagastrin from 0 to 80 micrograms/kg.h there was a dose-related increase in mucosal blood flow increments above resting levels. A linear correlation (r = 0.7) was observed between increments in acid output and increments in mucosal blood flow with increasing doses of pentagastrin from 0 to that producing maximal acid secretion (40 micrograms/kg.h). Inhibition of pentagastrin-stimulated acid secretion by cimetidine or omeprazole returned stimulated gastric mucosal blood flow to baseline levels.

Animals↗
PubMed1984

Moderate-level gene amplification in methotrexate-resistant Chinese hamster ovary cells is accompanied by chromosomal translocations at or near the site of the amplified DHFR gene.

In previous studies, we have described several classes of methotrexate-resistant Chinese hamster ovary cell lines. Although the RI class is resistant because of an altered target enzyme, dihydrofolate reductase, the RIII class derived from RI cells is somewhat more resistant because of a moderate amplification of the altered dhfr structural gene (Flintoff et al., Mol. Cell. Biol. 2:275-285, 1982). In one RIII line, a translocation between the short arm (p) of chromosome 2 and the long arm (q) of chromosome 5 was observed, and the amplified RIII gene complex was mapped to the p arm of the 2p-marker chromosome derived from the translocation (Worton et al., Mol. Cell. Biol. 1:330-335, 1981). We tested the hypothesis that chromosomal translocation is a general feature of RIII cells and that such translocation involves a site at or near the dhfr structural gene. Thus, we examined four independently derived RIII-type mutants and found that each had a moderate amplification of the dhfr gene sequences, and karyotype analysis revealed that each carried a translocation involving the 2p arm at or near band 2p25. That this chromosomal rearrangement involves a site near the dhfr locus was demonstrated by mapping the altered but unamplified structural gene coding for the RI phenotype to the short arm of an unaltered chromosome 2. This suggests that a highly specific rearrangement involving an exchange at or near the site of the unamplified gene is a necessary prerequisite for the amplification process. A model for gene amplification involving chromosomal rearrangements and sister chromatid exchange is described.

Animals↗
PubMedDate not supplied

An Internet multicast symposium concerning the microcirculation of the islets of Langerhans.

The Internet Globally-linked Computer System was used to conduct an international scientific symposium. The symposium was held at the VAMC-Long Beach and consisted of prepared lectures that were multicast over the Internet. The basic unit of hardware used for the Internet Multicast was the Silicon Graphics Indy Unix Workstation, which was equipped with a color video camera. The multicast required four additional pieces of software from the file transfer protocol. The multicast backbone protocol allowed for simultaneous audio and video signals (the presenter, the slides, and the videotape images of islet microcirculation studies) to be transmitted over the computer network. The faculty included 12 experts in microcirculation, who gave 15-min lectures that included a question and answer period. All lectures were received at 14 computer stations in six countries. Eleven of the faculty gave their lectures at the VAMC-Long Beach, and one gave her lecture at the Massachusetts Institute of Technology in Boston, MA. The presenter from Boston was able to receive and answer questions from the faculty at the VAMC-Long Beach. An estimated $12,000 was saved in travel, hotel, and food costs and an estimated 180 travel hours were saved by viewers who did not have to travel to the symposium. We have demonstrated that a scientific symposium can be conducted using the Internet. We propose that many of our future meeting will be organized over the computer network. This format of multiimage projections allows us to effectively communicate in a personal way with a reduction in expensive and time-consuming travel.

Animals↗