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Biomedical subjects

C Sheppard

Publications and source records attributed to C Sheppard.

At least 19 recordsLinked to original sources
PubMed2001

Coral reefs: beyond mortality?

The scale of the collapse of coral reef communities in 1998 following a warming episode (Wilkinson, 2000) was unprecedented, and took many people by surprise. The Indian Ocean was the worst affected with a coral mortality over 75% in many areas such as the Chagos Archipelago (Sheppard, 1999), Seychelles (Spencer et al., 2000) and Maldives (McClanahan, 2000). Several other locations were affected at least as much, with mortality reaching 100% (to the nearest whole number); this is being compiled by various authors (e.g., CORDIO, in press). For example, in the Arabian Gulf, coral mortality is almost total across many large areas of shallow water (Sheppard, unpublished; D. George and D. John, personal communication). The mortality is patchy of course, depending on currents, location inside or outside lagoons, etc., but it is now possible to swim for over 200 m and see not one remaining living coral or soft coral on some previously rich reefs.

Animals↗
PubMed2001

Mediocre media.

Explore the source record for details and available documents.

Conservation of Natural Resources↗
PubMed2001

The main issues affecting coasts of the Indian and western Pacific Oceans: a meta-analysis from Seas at the Millennium.

A review of the world oceans in three volumes by 365 scientists, provides scope for several 'meta-analyses' of the main problems affecting over 100 areas in the year 2000. This article summarises the main issues affecting a sub-set of the reviewed areas, covering Asian, African and Arabian countries dealt with in Volume 2, which included over 50 articles. From all issues raised, assessment is made of the nature of the major ones, including evaluation of reasons why so many of them remain important issues after so much attention to them. These include long standing problems, several problems more newly flagged as becoming particularly important, the issue of global warming and no less than three related issues connected with fishing and over exploitation. One or two issues such as industrial pollution and sewage, previously considered of almost universal concern, almost traditional pollution issues even, continue to feature strongly for some countries, but while these were almost always referred to in Seas chapters, by and large these categories appear not to be the most pressing of issues today, except in localized areas (albeit areas where huge numbers of people live). Perhaps other issues have simply taken over. They are excluded from this article.

Animals↗
PubMed2001

Development and evaluation of an antibody capture ELISA for detection of IgG to Epstein-Barr virus in oral fluid samples.

The development of an EBV IgG antibody capture ELISA (GACELISA) for detection of EBV viral capsid antigen specific IgG in oral fluids is described. The assay was optimised and evaluated using paired serum and oral fluid samples from healthy laboratory staff (n=82) and oral fluids collected either for routine measles, mumps, and rubella testing (n=629) or for an epidemiological study of atopic dermatitis (n=252). Statistical analysis by mixture modelling was used to determine the GACELISA cut-off and to estimate the sensitivity and specificity of the assay. Sensitivity and specificity was also assessed by comparing the results of immunofluorescence assay for EBV specific IgG in serum with those of GACELISA in 82 matching oral fluids. Compared to serum immunofluorescence assay, oral fluid GACELISA was found to have a sensitivity of 82.2 and 88.9% specificity with these samples. Mixture modelling, predicted the GACELISA to be 88.4% sensitive and of 99.4% specific. The prevalence of antibody to EBV in oral fluids was found to be 73.8% in laboratory staff, 34.4--73.9% in measles, mumps, and rubella patients and 22.2% in atopic dermatitis study participants. A robust, reliable and reproducible EBV GACELISA has been developed which will be a useful tool for epidemiological investigations.

Adolescent↗
PubMed2001

Endothelium-derived nitric oxide synthase protein expression in ovine placental arteries.

During the third trimester, fetoplacental and uterine blood flows increase dramatically to meet the high metabolic demands of the growing fetus. We hypothesized that the expression of endothelial nitric oxide synthase (eNOS) in fetoplacental artery endothelium and the concentrations of nitric oxide (NO) and cyclic GMP (cGMP) in amniotic fluid (AF) are increased during the third trimester of ovine gestation. Placental arteries and AF were collected from ewes at 110, 120, 130, and 142 days of gestation (n = 24; mean +/- SEM term = 145 +/- 3 days). Expression of eNOS protein was measured in intact and denuded placental arteries and in endothelium-derived protein by Western analysis and confirmed by immunohistochemistry. Concentrations of NO (nitrates plus nitrites) and cGMP were determined in AF. Placental artery eNOS protein expression was localized to the endothelium, where it was markedly greater than in vascular smooth muscle. Placental artery endothelium-derived eNOS expression and AF cGMP concentrations were similar at 110 and 120 days of gestation; however, both peaked at 130 days at levels two- to threefold above baseline (P < 0.05) before returning to baseline at 142 days of pregnancy. The AF NO (nitrates plus nitrites) levels, however, increased progressively between 120 days of gestation and term (P < 0.05). We concluded that endothelium-derived placental artery eNOS levels, AF NO (nitrates plus nitrites), and AF cGMP were markedly increased during the third trimester, thus supporting a role for NO-mediated elevations in cGMP in the control of fetoplacental blood flow.

Amniotic Fluid↗
PubMed1999

Effects of angiogenic growth factors on endothelium-derived prostacyclin production by ovine uterine and placental arteries.

Uteroplacental and fetoplacental arteries produce substantial amounts of prostacyclin (PGI2). Because angiogenic growth factors such as basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) are increased in pregnancy, we hypothesized that treatment of uterine and fetoplacental arteries with bFGF, VEGF, and EGF would further enhance the pregnancy-induced increase in PGI2 production. Duplicate uterine (UA) and fetoplacental (PA) artery (primary branch off of the umbilical cord = pPA; cotyledonary or tertiary = tPA) explants from seven late gestation sheep were placed in tissue culture (RPMI; 37 degrees C) for 24 h alone or with (1-100 ng/mL) bFGF, VEGF, or EGF. To evaluate the endothelial contribution to basal and stimulated PGI2 production and to determine whether it is de novo, arteries with and without endothelium from three additional late gestation ewes, tissues were incubated in the absence or presence of growth factors with or without meclofenamate (1 microM). The stable metabolite of PGI2, 6-keto-PGF1 alpha, was measured in culture media and expressed as ng/mg wet wt 24 h. PGI2 production by UA increased (p < 0.05) from 5.43 +/- 0.26 at control to 8.93 +/- 0.99 with 100 ng/mL bFGF. Although VEGF produced a similar response, EGF did not increase PGI2 production in UA. In pPA, 100 ng/mL bFGF induced a 2.2-fold increase (p < 0.01) in PGI2 production from 1.94 +/- 0.14 to 4.20 +/- 0.31; VEGF and EGF were without effect. In tPA, 50 and 100 ng/mL bFGF increased PGI2 production from 1.98 +/- 0.14 to 3.5 +/- 1.05 and 3.96 +/- 0.46 (p < 0.02). In tPA, VEGF did not increase PGI2 production; however, 10, 50, and 100 ng/mL EGF, enhanced (p < 0.03) PGI2 production from 1.98 +/- 0.14 to 3.39 +/- 0.62, 3.62 +/- 0.26, and 2.93 +/- 0.20. Endothelium removal and meclofenamate treatment caused a 90% and 100% decrease, respectively, in basal PGI2 production, with no recovery after treatment with growth factors. We conclude that PGI2 production is augmented by bFGF in UA, pPA and tPA, by VEGF in UA, and by EGF in tPA during ovine pregnancy. Basal and stimulated PGI2 secretion is endothelium-derived via de novo synthesis. bFGF, VEGF, and EGF, in addition to angiogenesis, may modulate PGI2 production, further enhancing blood flow to the growing uteroplacental bed.

Animals↗
PubMed1998

Methylenetetrahydrofolate reductase and methionine synthase: biochemistry and molecular biology.

Methylenetetrahydrofolate reductase and cobalamin-dependent methionine synthase catalyze the penultimate and ultimate steps in the biosynthesis of methionine in prokaryotes, and are required for the regeneration of the methyl group of methionine in mammals. Defects in either of these enzymes can lead to hyperhomocysteinemia. The sequences of the human methylenetetrahydrofolate reductase and methionine synthase are now known, and show clear homology with their bacterial analogues. Mutations in both enzymes that are known to occur in humans and to be associated with hyperhomocysteinemia affect residues that are conserved in the bacterial enzymes. Structure/function studies on the bacterial proteins, summarized in this review, are therefore relevant to the function of the human enzymes; in particular studies on the effects of bacterial mutations analogous to those causing hyperhomocysteinemia in human may shed light on the defects associated with these mutations.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1996

Fetal heart rate changes after intrathecal sufentanil or epidural bupivacaine for labor analgesia: incidence and clinical significance.

The objective of this study was to compare the incidence of intrapartum fetal heart tracing (FHT) abnormalities and the obstetric outcome after intrathecal sufentanil (ITS) versus epidural bupivacaine (EB). During the period from April to September 1994, 129 patients who met inclusion criteria were prospectively identified during labor at a single university-affiliated hospital. Inclusion criteria included: singleton, gestational age > or = 36 wk, and cephalic presentation. In the ITS group, epidural anesthesia was not administered before 60 min after ITS. Sixty-five consecutive ITS patients were compared to 64 consecutive EB patients. Each FHT was reviewed independently by two obstetricians blinded to the type of analgesia. The FHT characteristics evaluated included baseline rate, variability, and periodic changes. No differences in the incidence of clinically significant FHT abnormalities (recurrent late decelerations and/or bradycardia) were observed between the two groups (ITS 21.5% versus EB 23.4%). The rates of clinically significant FHT abnormalities in both groups was not different when patients with hypotension and medical complications were excluded (16.9% vs 17.1%). In addition, equal rates of hypotension (18.5% vs 17.2%) were noted between the groups. In both groups there was a significantly higher risk of cesarean section in patients whose previously normal FHT became abnormal postanalgesia when compared to patients without a new onset FHT abnormality (ITS 28.6% [4/14] versus 2.0% [1/51], P < 0.01; EB 33.3% [5/15] versus 8.2% [4/49], P < 0.05). This increased risk was associated with an increase in cesarean section for nonreassuring FHT in both groups (ITS 14.3% [2/14] versus 0% [0/51], P = 0.04; EB 13.3% [2/15] versus 0% [0/49], P = 0.05). These results support the conclusion that the incidence of clinically significant FHT abnormalities and hypotension is equivalent in patients receiving ITS when compared to EB within the first hour of administration. During this period, patients should have continuous FHT monitoring since a new onset FHT abnormality unveils and alerts the physicians to a possible compromised fetal condition and a corresponding increased risk of cesarean section.

Adult↗
PubMed1989

Coronary care in New York City hospitals.

New York City, with six medical schools and an elaborate emergency medical system, would appear to be a locale with optimal resources for coronary care. To assess coronary care facilities and practices, a comprehensive questionnaire was prepared by a multidisciplinary committee and submitted to 72 hospitals. Seventy-nine percent (57/72) responded, including all medical school affiliated hospitals and 41 of the 45 with more than 300 beds. Twenty-nine percent (16/55) did not have a coronary care unit separate from a general intensive care unit. Thirty-three percent (18/55) of coronary care units were designed before 1970. Although 85% (46/54) of the coronary care units had a 1:2 registered nurse per patient ratio during days, only 43% (23/54) maintained this ratio at night. Central monitoring was available in all hospitals, but only 40% (21/52) indicated 24-hour continuous monitor observation. Forty-five percent (25/55) had cardiac catheterization facilities, and 43% (24/56) had an intra-aortic balloon available. Forty-six percent (26/57) of coronary care units transferred post-myocardial infarction patients to non-monitored general beds. Fifty-eight percent (31/53) offered dietary counseling to patients, and 33% (18/54) had an inpatient cardiac rehabilitation program. Thus, New York City hospitals demonstrate a marked variability in coronary care unit facilities and practices and a substantial number of hospitals deviate from published recommendations for coronary care units.

Coronary Care Units↗
PubMed1976

Public perception of ex-mental patients.

Data are presented from two studies which show that perceptions of ex-mental patients appear to derive from a lack of information and that the provision of information alters the perception of former patients. Perceived unpredictability of behavior and dangerousness seem to form a dyad that causes the public to fear the mentally ill. More positive perceptions of mildly ill ex-mental patients were obtained when subjects were given short paragraphs describing typical behaviors and symptoms. These findings support the notion that a fear-motivated threat recoil cycle process is likely to be evoked by attempts to establish locally based treatment facilities, particularly in residential communities.

Attitude to Health↗
PubMed1975

The effect of increased information upon community perception of ex-mental patients.

Data are presented for 30 suburban homeowners, which suggest they respond differentially to three levels of severity when rating the concept ex-mental patients via the semantic differential technique after having been given descriptive information about typical symptoms and behaviors. This finding contrasts with those from a previous study of similar suburbanites which indicated nonindividuation among severity of illness levels under minimal information conditions. A more favorable perception of mildly ill ex-mental patients resulted from the exposure to more information.

Attitude↗
PubMed1975

Comparative survey of psychiatrists' prescription preferences: New York and Texas.

The present survey compares the treatment preferences of New York and Texas psychiatrists using a questionnaire report of a single psychiatric case. The characteristics of this approach enable the investigator to hold and symptoms and syndromes of the patient constant. All clinicians respond to identical stimuli. What varies naturally, then, is the judgment of the clinician in developing his treatment procedure, thereby enabling estimation of the degree of standardization in treatment preferences. Three hundred twelve psychiatrists from New York and 133 from Texas provided data for comparative purposes. On the first admission 41% of the New York respondents and 24% of the Texas psychiatrists preferred a regimen that included more than one drug. When a combination of drugs was selected, chlorpromazine-trifluoperazine was preferred. But ten other specific combinations also were selected. Most were of potent neuroleptics, but some included antidepressant-neuroleptic combinations. None of the variables included in the study provided tangible systematic variance for these treatment preferences. A year and a half after first admission, followed by treatment in and out of hospital, the patient's clinical course continued to deteriorate. At this point more than 50% of the respondents in each state selected a regimen that included a minimum of two drugs. As many as 24 different combinations were selected for this single case. Nineteen percent of the New York respondents and 13% of the Texas respondents selected a regimen that included three or more psychoactive medications. The existence of these treatment preferences requires a more basic understanding of treatment preferences, for these seems to be no basis for them.

Adolescent↗
PubMed1975

Combination drug therapy for the psychogeriatric patient: comparison of dosage levels of the same psychotropic drugs, used singly and in combination.

The dosage levels for a number of frequently prescribed psychotropic drugs, used singly or in combination, were determined in 902 long-term psychogeriatric hospital patients. The data failed to support the hypothesis that physicians prescribe lower dosages when combination therapy is used. Rather, the tendency was toward higher dosages under these circumstances.

Aged↗