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Biomedical subjects

R M Moore

Publications and source records attributed to R M Moore.

At least 91 records · Page 5Linked to original sources
PubMed1990

Prenatal ultrasound: are socially disadvantaged groups afforded equal access?

A retrospective cohort study was conducted of the patterns of ultrasound use during pregnancy for all single live births (n = 2542) delivered at a major teaching hospital in one calendar year. Extent of maternal education was inversely correlated with the probability of receiving a prenatal ultrasound examination (p less than 0.001). Clinic patients were more likely to receive prenatal ultrasound examinations than were private patients (p less than 0.001). Blacks were more likely than whites to receive prenatal ultrasound examinations (p less than 0.001). Short duration of prenatal care, inadequate weight gain during pregnancy, and history of previous pre-term delivery were all associated with an increased probability of receiving a prenatal ultrasound examination (p less than 0.001).

Black or African American↗
PubMed1990

Use of diagnostic ultrasound, X-ray examinations, and electronic fetal monitoring in perinatal medicine.

Obstetrical technologies such as electronic fetal monitoring (EFM) and selected diagnostic imaging procedures can be integral components of perinatal care. The Center for Devices and Radiological Health, a unit within the Food and Drug Administration, collaborated with the National Center for Health Statistics in the design and conduct of a National Maternal and Infant Health Survey to collect information from prenatal care providers, hospitals, and mothers on the use of EFM, diagnostic ultrasound, and x-ray examinations during pregnancy, labor, and delivery. A pretest, conducted some months before the survey began, showed that 78.8% of the pregnancies surveyed received a diagnostic ultrasound examination during pregnancy. Approximately 58.3% of the ultrasound-exposed mothers had two or more such examinations. Approximately 10.1% of the ultrasound examinations were performed in the first trimester of pregnancy, 57.0% in the second trimester, and 32.9% in the third trimester. The most common indication for an ultrasound examination was to establish dates or gestational age. Approximately 15.3% of the pregnancies surveyed received an x-ray examination. Approximately 74.6% of the pregnancies were monitored with EFM during labor. External EFM was used alone during 54.9% of the labors and along with internal EFM during 19.7% of the labors. The implications of these pretest findings are discussed, along with a review of the medical literature on the safety and effectiveness of these medical device technologies.

Delivery, Obstetric↗
PubMed1989

Adenosine triphosphate activates the phospholipase-C cascade system in human amnion cells without increasing prostaglandin production.

Human amnion is hypothesized to be a target tissue for hormone messages from the fetus regarding labor. We have previously demonstrated prostaglandin E2 (PGE2) release in amnion after treatment with phorbol and oxytocin, but other potential agonists of the inositol phospholipid/protein kinase-C system have not been investigated. The effects of extracellular ATP on cytosolic calcium concentration [( Ca2+])i) inositol phosphate (IP) accumulation, and PGE2 production were studied in cultured human amnion cells. Intracellular free calcium [Ca2+]i was measured using the fluorescent dye fura-2. Addition of 0.01-30 microM ATP resulted in a [Ca2+]i transient which peaked within 15 sec and returned to baseline over 10 min. UTP (1 microM) was more effective than ATP (1 microM); [Ca2+]i levels rose from 233 to 2880 nM (UTP) and 2320 nM (ATP). A reduced effect was observed with other nucleotides in a rank order of agonist potency of ITP greater than CTP greater than ADP greater than GTP greater than TTP. No effect was seen with AMP, cAMP, or adenosine. This is consistent with P2 purinoceptors, as described in other tissues. ATP (100 microM) also dramatically increased IP accumulation. Inositol triphosphate, inositol bisphosphate, and inositol monophosphate were increased 7-, 9-, and 16-fold respectively. The agonist potency order of other nucleotides for IP accumulation was the same as that of [Ca2+]i. Pharmacological concentrations of ATP (1 mM) were required to increase PGE2 production. Many other nucleotides were equally effective at this concentration. ATP activates the phospholipase-C system in human amnion, as demonstrated by the increase in [Ca2+]i and inositol phosphates. The physiological significance of purinergic stimulation of this tissue remains unclear.

Adenosine Triphosphate↗
PubMed1989

X-ray examinations during pregnancy: National Natality Surveys, 1963 and 1980.

Based on 1963 and 1980 National Natality Surveys, the rate of medical x-ray examinations during pregnancy per 100 mothers fell 34.2 percent. A decrease in chest x-ray examinations accounted for almost all of the decline in total x-ray examinations. The reductions were greater for older mothers and those who were not White. While the number of births fell from 4,071,000 in 1963 to 3,612,000 in 1980, the number of pelvimetry examinations actually increased by 45,000.

Adult↗
PubMed1988

Polyamines control human chorionic gonadotropin production in the JEG-3 choriocarcinoma cell.

The effect of inhibition of ornithine decarboxylase with difluoromethylornithine (DFMO) and the resultant lowering of polyamine levels upon human chorionic gonadotropin (hCG) production in JEG-3 choriocarcinoma cells was investigated. DFMO (10 mM) totally inhibited ornithine decarboxylase activity. In DFMO-treated cells, cellular spermidine concentrations fell to nondetectable levels (less than 1% of control values) within 24 h and spermine concentrations were reduced to 41.9% of controls over 6 days. DFMO caused a 70-80% inhibition of hCG production. Levels of mRNA for both the alpha and beta subunits of hCG were also inhibited relative to mRNA for tubulin. Exogenous putrescine normalized hCG production in a dose-dependent manner. Other diamines, including cadaverine, 1,3-diaminopropane, 1,6-diaminohexane, and 1,7-diaminoheptane, were ineffective in reestablishing hCG production in DFMO-treated cells. Dibutyryl cAMP (1 mM) stimulated hCG production and increased levels of mRNA for the alpha and beta subunit 5-40-fold in both DFMO-treated and control cells. Polyamines appear to have a fundamental role in hCG production in JEG-3 choriocarcinoma cells. However, dibutyryl cAMP can partially overcome or circumvent the requirement for polyamines in hCG biosynthesis.

Bucladesine↗
PubMed1988

Oxytocin activates the inositol-phospholipid-protein kinase-C system and stimulates prostaglandin production in human amnion cells.

It has been postulated that fetal hormonal signals act upon amnion to trigger labor via prostaglandin (PG) production. Human amnion epithelial cell cultures were established to test the effects of potential activators of the inositol phospholipid-protein kinase-C effector system on intracellular inositol phosphate turnover, intracellular free calcium ([ Ca2+]i), and PGE2 production. Oxytocin provoked 3-, 2.5-, and 4-fold increases in inositol triphosphate, inositol bisphosphate, and inositol monophosphate, respectively. [Ca2+]i, measured with the fluorescent dye fura-2, was stimulated by oxytocin and vasopressin (oxytocin greater than vasopressin) in a dose-dependent manner. The [Ca2+]i transient produced by oxytocin reached a peak in 15 sec, followed by a slow return to baseline over 10 min. Preincubation with phorbol 12-myristate-13 acetate (PMA) markedly blunted the oxytocin-induced transient. No [Ca2+]i transient was seen with leukotrienes, PG, serotonin, angiotensin, or alpha- or beta-adrenergic agents. PGE2 production increased 30- to 50-fold with phospholipase-C and PMA, and 10-fold with the calcium ionophore A23187. Oxytocin and vasopressin produced 10- and 3-fold PGE2 increases, respectively. Increased PGE2 production induced by PMA, oxytocin, and A23187 was first seen after 8 hr of incubation and reached maximal levels at 24 h. Minimal PGE2 stimulation occurred with agents that produced no [Ca2+]i transient. Direct activators of the inositol phospholipid-protein kinase-C system in human amnion induce large increases in PGE2 in human amnion cells. Oxytocin and vasopressin are hormonal activators of this system in these cells, as demonstrated by their effects on inositol phosphate turnover and [Ca2+]i. These hormones also increase PGE2 production and may influence labor by stimulating PGE2 production in amnion through the inositol phospholipid-protein kinase-C system.

Amnion↗
PubMed1988

Cyclic 3',5'-adenosine monophosphate-dependent kinase and phosphoproteins in human amnion.

3',5'-Cyclic adenosine monophosphate (cAMP) modulates prostaglandin production in human amnion membranes. The major effects of cAMP are presumably mediated through the phosphorylation of specific regulatory phosphoproteins following cAMP activation of cAMP-dependent protein kinase. Cyclic AMP-dependent protein kinase and phosphoproteins have not previously been characterized in human amnion. Total homogenates, cytosol, and membrane fractions from human amnion were examined for [3H]cAMP binding activity and cAMP-dependent kinase activity. cAMP-dependent kinase activity was barely detectable in crude amnion fractions. Cytosol was therefore partially purified by DEAE column chromatography for further examination. Two peaks of coincident [3H]cAMP binding and cAMP-dependent kinase activity were demonstrated at 70 and 140 mM NaCl, characteristic of the Type I and Type II cAMP-dependent protein kinase isozymes. [3H]cAMP binding to the material from both peak fractions was saturable and reversible. Scatchard analysis of [3H]cAMP binding to the peak fractions was linear for peak I and curvilinear for peak II. Assuming a one-site model, [3H]cAMP binding to the Type I isozyme showed a KD = 4.17 x 10(-8) M and Bmax = 73 pmole/mg protein; using a two-site model, [3H]cAMP binding to the high-affinity site for the Type II isozyme had a KD = 3.94 x 10(-8) M and Bmax = 6.3 pmole/mg protein. Other cyclic nucleotides competed for these [3H]cAMP binding sites with a potency order of cAMP much greater than cGMP greater than (BU)2cAMP.cAMP caused a dose-dependent increase in cAMP-dependent kinase activity in the peak fractions; half-maximal activation was observed with 5.0 x 10(-8) M cAMP. The ability of cAMP to increase phosphorylation of endogenous proteins in both crude amnion cytosol and cytosol from cultures of amnion epithelial cells was assessed using [32P]ATP, SDS-polyacrylamide gel electrophoresis and autoradiography. cAMP stimulated 32P incorporation into three proteins having Mr = 80,000, 54,000, and 43,000 (P less than .01). Half-maximal 32P incorporation into these proteins occurred at 1.0 x 10(-7) M cAMP. cAMP-dependent kinase is present in human amnion; specific cAMP-enhanced phosphoproteins are also present. Hormones elevating cAMP levels in amnion may exert their effects by activating cAMP-dependent kinase and phosphorylating these phosphoproteins.

Amnion↗
PubMed1988

The relationship of birth weight and intrauterine diagnostic ultrasound exposure.

Imaging with ultrasound is common in obstetric practice. Several laboratory animal studies have shown retardation in fetal growth after experimental ultrasound exposure. This investigation was conducted to determine whether human fetuses exposed to diagnostic ultrasound (sonography) have a greater risk of growth retardation than fetuses not so exposed. This retrospective cohort study compares the birth weights of 1598 exposed and 944 unexposed single live births at the Johns Hopkins Hospital in Baltimore, Maryland during calendar year 1981. Confounding variables, defined as those associated with both exposure status and birth weight outcome, were included in multivariable analysis. Both exposure to more than one ultrasound procedure and first exposure during the third trimester were associated with a reduction in birth weight. However, the most consistent effect associated with birth weight appeared to be the indication for an ultrasound examination. The relationship of ultrasound exposure and reduced birth weight appeared to be due to shared common risk factors, which lead to both exposure and a reduction in birth weight.

Birth Weight↗
PubMed1988

AIDS response.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Protein separations on reversed-phase high-performance liquid chromatography minicolumns.

The resolution of cytochrome c, bovine serum albumin and ovalbumin on reversed-phase columns under gradient elution conditions was found to be constant or to improve as column length was decreased from 45 to 6.3 mm. The resolution remained constant even when the column length decreased to 1.6 mm. Recovery of protein in the first gradient cycle was improved by the use of short columns.

Animals↗
PubMed1984

Development of health risk evaluation data for diagnostic ultrasound: a historical perspective.

The growth of ultrasound applications in diagnostic medicine has helped stimulate related biological effects investigations. Current data related to effects associated with diagnostic ultrasound indicate the need for additional research on cell surface structures, motility and developmental effects. Research on biological effects, especially for evaluating in vivo end points analogous to those employed by investigators using in vitro systems and simple organisms, are needed. Particular emphasis relative to potential effects on fetal and embroyonic development is indicated. Limited data also suggest the need to investigate possible effects on the immune response. There is a growing realization of the potential importance of nonthermal effects and increasing evidence that the temporal peak intensity is potentially related to the production of some effects. A number of recent comprehensive reviews have helped identify, analyze and evaluate some of the relevant data.

Animals↗
PubMed1984

Protein diffusion coefficient measurements by laminar flow analysis: method and applications.

Laminar flow in an open tube leads to solute band spreading. This process is opposed by radial diffusion. The translational diffusion coefficient of a solute can be calculated from the band dispersion, tube length, and flow rate. No calibration is necessary. A simple apparatus was used to measure the diffusion coefficients of several small solutes and 18 proteins. Most results were within +/- 10% of literature values. Each determination required 7-90 min, depending on the magnitude of the diffusion coefficient. The amount of protein needed was approximately 25 micrograms. The diffusion coefficient data were useful for the estimation of molecular weights.

Chemical Phenomena↗
PubMed1982

Elevated serum iron in toxemia of pregnancy.

The records of 144 women with toxemia of pregnancy were evaluated retrospectively for clinical course and clinical laboratory parameters. A striking elevation of serum iron was noted when patients were most seriously ill. There was a prompt return to normal iron values with improved clinical status. The toxemia-associated rise in iron is out of proportion to the increase in other parameters, such as uric acid, blood urea nitrogen, and hematocrit. Possible explanations for this phenomenon are offered.

Adolescent↗
PubMed1981

Trimethoprim and co-trimoxazole in the treatment of acute urinary tract infections: patient compliance and efficacy.

Patient compliance and drug efficacy and side-effects were compared in two groups of patients with symptoms of acute lower urinary tract infections. One group was treated with trimethoprim, one tablet (300 mg) once a day, and the other with co-trimoxazole, two tablets (160 mg trimethoprim, 800 mg sulphamethoxazole) twice a day; both treatments were prescribed for seven days. Patient compliance was significantly greater with trimethoprim: corrected percentage compliance rates were 97.5 per cent for trimethoprim and 79.1 per cent for co-trimoxazole (p<0.05). Trimethoprim and co-trimoxazole were of equivalent effectiveness in the control of symptoms. Side-effects were more frequent with co-trimoxazole, but the difference was not significant.

Acute Disease↗
PubMed1981

Trial of a centralized IgE allergy service to general practitioners in a rural area.

We describe a pilot study of a community IgE service which serves a large rural area and is centred on the biochemistry laboratory and allergy clinic of a district general hospital. The service has proved useful because in many cases it has made attendance at an outpatient department unnecessary. The results appear to be reliable and have provided the general practitioners with additional knowledge of their patients. Other benefits included the investigation of larger numbers of patients, the performance of fewer skin tests and greater precision in test results because the tests were carried out by one investigator under standard conditions.

Diagnostic Services↗