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Biomedical subjects

K Gallagher

Publications and source records attributed to K Gallagher.

At least 19 recordsLinked to original sources

Maternal occupation and pregnancy outcome.

Few studies have addressed the effect of maternal employment on late pregnancy outcomes. The National Maternal and Infant Health Survey, a probability sample of U.S. livebirths, stillbirths, and infant deaths in 1988, provided an opportunity to evaluate mothers' jobs in relation to preterm delivery, very low birthweight ( < 1,500 gm), moderately low birthweight (1,500-2,499 gm), small-for-gestational-age (SGA) birth, stillbirth, and infant death. We aggregated mothers' jobs, which were ascertained by mailed questionnaire or telephone interview, into categories for analysis. We considered jobs held at any time during pregnancy and jobs held during the fifth month of pregnancy. Relative to the referent group of clerks, textile workers had adjusted odds ratios of 1.5 or greater for all outcomes, with elevated risks also found sporadically for food service workers (preterm delivery, SGA birth, stillbirth) and electrical equipment operators (all outcomes except for still-birth and infant death). Janitors had elevated adjusted odds ratios of 2.0 or greater for preterm delivery and stillbirth. Relative to clerks, teachers and librarians tended to have reduced risks for adverse outcomes.

Adolescent

Report of the American Diabetes Association's Task Force on standardization of the insulin assay.

Recent large-scale epidemiological studies demonstrate that blood concentrations of immunoreactive insulin predict the development of NIDDM and IDDM and are associated with the risk of several degenerative diseases, such as coronary and peripheral vessel atherosclerosis, hypertension, and dyslipidemia. The reliability of these measurements is dependent on a biological assay that has not been well standardized between laboratories. Recognizing this, the American Diabetes Association organized a task force to assess comparability of blood insulin measurements between laboratories and to suggest techniques to improve comparability. The task force found that identical serum and plasma samples measured in different laboratories produced widely disparate values that were unacceptable for population comparisons. Use of a single reference standard did little to improve comparability. Assay characteristics such as linearity, recovery, accuracy, and cross-reactivity to proinsulin and its primary conversion intermediates varied among the laboratories, and they did not readily explain differences in the measurements made from assay to assay. Use of the same assay kit in different laboratories did not always ensure comparable measurements. Linear regression of assay results from one laboratory to an arbitrarily chosen reference assay greatly improved comparability and demonstrated the potential value in comparing each assay to a reference method. The task force report defines acceptable assay characteristics and proposes a three-step process of insulin assay proficiency and comparability. A central reference assay and ongoing sample exchange will be needed to allow reliable comparisons of insulin measurements made in different laboratories. Rigorous quality control and continuous quality improvement are needed to maintain reliability of the insulin measurement.

Diabetes Mellitus

The wired physician: current clinical information on the Internet.

The Internet and associated World Wide Web are electronic technologies that can help physicians identify needed clinical information quickly and can put physicians in ready contact with other specialists for communication and consultation. This article outlines the kinds of resources available on the Internet and methods for connecting your personal computer to the "information superhighway." Selected Internet sites and a short bibliography of books and articles relating to the Internet are included.

Computer Communication Networks

Using administratively collected hospital discharge data for AIDS surveillance.

The objectives of this study were twofold: to improve methods of identifying possible and acquired immunodeficiency syndrome (AIDS)-related hospital discharges in administrative databases and to measure AIDS-reporting completeness in Massachusetts both overall and by subgroup. We used fiscal year 1988 discharge data from the Massachusetts Rate Setting Commission (RSC) and data from the Massachusetts AIDS Reporting System (ARS). We identified 3362 discharges of adult patients (> 12 years old) from the RSC file that had diagnosis codes which are human immunodeficiency virus (HIV)-specific (042.x, 043.x, 044.x, or 795.8) or pertain to AIDS-defining "manifestations." Medical records of 650 patients apparently not reported to the ARS were reviewed. THe best set of codes overall consisted of either (a) the 042.x code or (b) the 043.x, 044.x, or 795.8 code plus selected manifestation codes (sensitivity, 93%; specificity, 86%; predictive value positive, 71%). Of the 927 AIDS cases identified from the 3362 discharges, only 36 had not been reported. AIDS cases among women (odds ratio (OR) = 2.9; 95% confidence interval (CI): 1.33 to 6.33), intravenous drug users (OR = 4.2; 95% CI: 2.20 to 8.02), and persons residing outside the Boston metropolitan area (OR = 2.3; 95% CI: 1.18 to 4.57) were more likely to be unreported than those among comparison groups.

AIDS-Related Opportunistic Infections

Developing a health sciences library Gopher: more involved than meets the eye.

The purpose of this paper is to discuss the development of the Health Sciences Library Gopher at St. Louis University (SLU) Health Sciences Center. The authors will outline university criteria from the Office of Computing and Information Services, library selection criteria, bibliographical access, reference and instructional implications, data entry and maintenance, and the role of the library's Internet Committee. All libraries have been awed by the tremendous amount of resources available through the Internet; the challenge is to not be intimidated but to be innovative in designing systems that can present these resources to the library client in the most easily understandable approaches possible. The Internet Committee in the SLU Health Sciences Center Library has designed a framework for the construction of "menus" to lead the client to selected Internet resources. Some of the issues confronted include relating the Internet resources to the library's Collection Development Policy, coordination of Internet resources to other bibliographic sources (Journal Holdings List, Intelligent Catalog), and educating staff and clients to manage a wide range of new resources as well as traditional ones in electronic formats.

Computer Communication Networks

Consistent responses of the human vascular smooth muscle cell in culture: implications for restenosis.

PURPOSE: The mechanisms whereby restenoses occur at discrete sites within the vasculature remain uncertain. We have recently reported that vascular smooth muscle cells (VSMC) derived from patients with graft stenoses are resistant to growth inhibition by heparin. In this study, we have examined whether VSMC proliferation rates and responses to inhibition by heparin vary according to the individual or the anatomic site of origin. METHODS: Long saphenous veins from seven patients were divided into proximal, middle, and distal portions, and VSMC were cultured separately from each. VSMC proliferation in response to 15% fetal calf serum +/- 100 micrograms/ml heparin was measured by counting triplicate samples at 0, 3, 7, 10, and 14 days. This experiment was repeated from the second to the sixth passage (n = 6) and for artery and vein pairs derived from four additional patients. RESULTS: Differences between vein segment cultures of individual veins were found not to differ significantly from experimental error for either proliferation or heparin inhibition and were not altered by repeated passage (ANOVA). There were, however, significant differences in sensitivity to heparin inhibition between patients (p = 0.02) (ANOVA). There were no significant differences between paired samples of artery and vein for either proliferation or heparin inhibition (Mann-Whitney test). CONCLUSIONS: VSMC growth characteristics reflect the individual patient and are maintained in cell culture.

Analysis of Variance

Growth inhibition of human vascular smooth muscle cells by fenofibrate: a possible therapy for restenosis.

OBJECTIVE: The aim was to assess the growth inhibitory effect of fibrates on human vascular smooth muscle cells. Restenosis is the most important factor limiting the long term success of invasive vascular interventions and there is as yet no effective preventive treatment. Platelet derived growth factor (PDGF) is considered to be an important growth promoting agent for vascular smooth muscle cells (VSMC) and fenofibric acid (a hypolipidaemic drug) has been reported to be a PDGF antagonist. METHODS: The effect of the fibrate drugs fenofibrate, clofibrate, bezafibrate, and gemfibrozil were examined on the proliferation of cultured human vascular smooth muscle cells derived from saphenous vein (n = 20) and graft stenoses (n = 7). RESULTS: Fenofibrate (100 microM) produced potent inhibition (48%) of VSMC proliferation at a concentration equivalent to that of its circulating metabolite fenofibric acid, but none of the other drugs produced any significant effect on growth. VSMC derived from graft stenoses were equally sensitive to inhibition as saphenous vein derived controls, in contrast to our previous work which reported that graft stenosis derived VSMC were resistant to growth inhibition by the physiological inhibitor heparin. The antiproliferative effect of fenofibrate was independent of inhibition of cellular cholesterol synthesis or toxicity. Fenofibrate inhibited VSMC growth induced by 15% fetal calf serum, PDGF, and basic fibroblast growth factor to a similar degree, indicating that it is not a specific PDGF antagonist. CONCLUSIONS: Fenofibrate is not a specific PDGF antagonist. Fenofibric acid, one of the principal metabolites of fenofibrate, did not produce any inhibition of growth, suggesting that oral administration of fenofibrate would not be efficacious. Fenofibrate is the first potent inhibitor to be described for VSMC derived from human myo-intimal hyperplastic lesions.

Bezafibrate

Effect of calcium channel blockers on the growth of human vascular smooth muscle cells derived from saphenous vein and vascular graft stenoses.

Vascular restenosis after invasive interventions is an important clinical problem for which no preventive pharmacologic therapy exists. Calcium channel blockers have been shown to inhibit myointimal hyperplasia in animal models of restenosis and in some small and flawed clinical coronary restenosis trials. We examined the inhibitory effect of amlodipine, verapamil, and diltiazem on the growth of cultured human vascular smooth muscle cells (VSMC) derived from saphenous vein (n = 20) and graft stenoses (n = 7), in 14-day proliferation assays and [methyl 3H]thymidine uptake studies. Amlodipine and verapamil produced significant inhibition (30%) of VSMC proliferation and DNA synthesis at 10 microM but not at 500 nM-1 microM. To our knowledge, this is the first study to examine the antiproliferative effect of calcium channel blockers in VSMC derived from human graft stenoses. Growth inhibition of VSMC from graft stenoses was not significantly different from that of control saphenous vein-derived cells. We conclude, therefore, that calcium channel blockers inhibit human VSMC proliferation in vitro, regardless of whether the cells were grown from graft stenoses or saphenous vein. However, the concentrations at which these calcium channel blockers elicit antiproliferative effects may not be attainable during therapeutic dosing in humans.

Amlodipine

Inhibition of human vascular smooth muscle cell proliferation by lovastatin: the role of isoprenoid intermediates of cholesterol synthesis.

Restenosis remains the largest single obstacle to the long-term success of invasive vascular interventions. Lovastatin, an HMG-CoA reductase inhibitor, has been shown to reduce myointimal hyperplasia in animal models of restenosis and in one clinical coronary restenosis trial. We have assessed the effect of lovastatin on the growth of cultured human vascular smooth muscle cells derived from saphenous vein and vascular graft stenoses. Lovastatin (2 microM) inhibited proliferation over 14 days in saphenous vein (and graft stenoses) derived vascular smooth muscle cells by 42% and 32% respectively: this was not significantly different. Lovastatin (10 microM) reduced [methyl 3H]-thymidine uptake by 51% in saphenous vein-derived cells. These concentrations were significantly higher than those achieved in plasma during therapeutic dosage. Lovastatin-induced inhibition of vascular smooth muscle cell proliferation and [methyl 3H]-thymidine uptake was completely reversed by adding mevalonate (100 microM) but cholesterol (10-40 micrograms ml-1) had no effect. Isopentenyl adenine (25-50 microM) did not affect the inhibition of [methyl 3H]-thymidine uptake by lovastatin (10 microM), but farnesol (20 microM), another isoprenoid precursor of cholesterol synthesis, reversed the antiproliferative effect.

Adenine

Accumulation of polychlorinated terphenyls in aquatic biota of an estuarine creek.

Aroclor 5432, a mixture of polychlorinated terphenyls (PCT), was detected in several biological compartments including saltmarsh cordgrass (Spartina alterniflora), American oysters (Crassostrea virginica), red-jointed fiddler crabs (Uca minax), wharf crabs (Sesarma reticulatum), and mummichogs (Fundulus heteroclitus) collected from Tabbs Creek. This tidal creek is located in the southern Chesapeake Bay region and contains sediments with high concentrations of PCT. Samples were collected at four sites, ranging from a suspected outfall near the head of the creek, to its mouth, approximately 2.5 river kilometers downstream. Species from several phyla were selected in order to examine PCT accumulation in physiologically and ecologically different organisms. PCT concentrations in sediment, saltmarsh cordgrass, native oysters, and fiddler crabs decreased with distance downstream. Residues in transplanted oysters and mummichogs showed a more variable trend with distance downstream. The organism with the highest mean concentration (18,300 micrograms/kg dry wt) was the native oyster, a benthic filter feeder.

Animals

Effect of regional myocardial ischemia on sympathetic nervous system as assessed by fluorine-18-metaraminol.

With the introduction of radiolabeled catecholamine analogues, the noninvasive evaluation of the cardiac sympathetic nervous system has become possible. This study evaluated the effect of regional ischemia on myocardial retention of the new norepinephrine analogue 6-[18F] fluorometaraminol (FMR) in the open chest dog model. Six dogs were injected intravenously with FMR following 30-min occlusion of the left anterior descending artery. Six sham animals served as control group. Regional myocardial blood flow as determined by microspheres decreased 87% during ischemia (p less than 0.01), but was not significantly different from control myocardium following reperfusion. Regional myocardial 18F activity as determined postmortem was significantly reduced in reperfused myocardium (-34%), which paralleled an 18% reduction of tissue norepinephrine concentration. Thus, short time periods of coronary occlusion affect neuronal function indicating the sensitivity of the sympathetic nerve terminals to ischemia. FMR provides a new tracer approach for the characterization of neuronal integrity in postischemic myocardium.

Animals

An outbreak of infectious conjunctivitis spread by microscopes.

Among the potential occupational hazards of microscope use is the transmission of infectious agents among employees. We report a large (145 cases) and costly (+647,000) epidemic of viral conjunctivitis in a microelectronics factory. Spread of the illness appeared to be through sharing of microscopes among employees. Routine handwashing instructions and safety glasses failed to prevent spread of the epidemic. Mandatory screening prior to work and temporary plant shut-down were finally successful. We discuss efforts to control this outbreak and make recommendations to prevent similar epidemics in other workplaces.

Conjunctivitis, Viral

Clinical response of hairy-cell leukaemia to interferon-alpha: results of an Australian study.

Twelve patients with documented, progressive hairy-cell leukaemia were treated with human lymphoblastoid interferon-alpha. All patients initially received a three-month course of interferon-alpha (3 x 10(6) U each day) which resulted in two complete remissions and 10 partial remissions. All eight patients who were dependent upon packed red-cell transfusions became independent of them and the three patients with the most severe, pretreatment pancytopenia also became independent of platelet transfusions. The histological appearance of the bone marrow improved in all patients; in three patients, a complete resolution of the leukaemic infiltrate was recorded. Adverse reactions occurred in 10 patients, but these were mild and did not interrupt treatment in seven patients. Moderate reactions that required a temporary reduction in the dose of interferon-alpha were seen in three patients. Ten patients subsequently received maintenance therapy with interferon-alpha (3 x 10(6) U, three times a week). A haematological improvement continued to be seen in all patients, and the results, with a minimum of one year of follow-up, are presented.

Adult

Bluefish-associated scombroid poisoning. An example of the expanding spectrum of food poisoning from seafood.

Five persons who attended a medical conference developed symptoms suggestive of an intoxication after a common meal. Although the symptoms were recognized as typical of scombroid poisoning, no fish of the Scrombridae family had been served. However, food histories implicated bluefish (Pomatomus saltatrix). The initially frozen bluefish had been improperly handled in storage and thawing. Elevated levels of histamine, putrescine, and cadaverine were detected in uncooked samples. This outbreak emphasizes that scombroid-type poisoning (1) can be caused by nonscombroid fish such as bluefish, (2) is probably more common than currently recognized, and (3) may become even more widespread as fish become a larger part of our diet. Physicians who work in conjunction with public health officials can help prevent additional cases and outbreaks.

Animals

Blood flow reductions in stenosed canine coronary arteries: vasospasm or platelet aggregation?

In 67 dogs with a 60-80% coronary stenosis produced by an external constricting plastic ring, blood flow measured with an electromagnetic flowmeter showed cyclical flow reductions of varying magnitude and duration, and then an abrupt return to control flow. In 45 dogs, heparin did not prevent these flow reductions, but ibuprofen (Motrin) or indomethacin abolished them. With incremental doses of each of these drugs, the cyclical flow reduction and the platelet function in vitro were diminished proportionately. In 10 more dogs, during low flow, pinching or poking the narrowed vessel suddenly restored normal flow. Topical application of papaverine and nitroglycerin proximal to the stenosis did not abolish the cyclic flow reduction, although a transient fall in systemic pressure indicated that they had been absorbed. Seven dogs had the constricting cylinder and flow probe chronically implanted for 4-6 weeks. A single oral dose of aspirin, 20 mg/kg, abolished their cyclic flow reductions for 2-4 days. In five dogs with 70% stenosis in the circumflex coronary artery, coronary arteriography was performed before coronary flow reduction and when coronary blood flow was low. This showed that there was a considerable additional reduction in the size of the mechanically constricted lumen during spontaneous flow reduction. In one dog, a nonopacified mass was dislodged from the area of constriction in 67 msec and this restored the lumen to its control diameter. Similar rapid clearing was filmed in two more dogs. In no case was vasospasm observed. These results suggest that obstruction from platelets aggregated in the narrowed lumen caused the cyclic flow reductions.

Animals