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Biomedical subjects

M Miller

Publications and source records attributed to M Miller.

At least 613 records · Page 34Linked to original sources
PubMed1988

Effects of phenylephrine on tissue gas tension, bleeding, infection, and lidocaine absorption.

In an attempt to find a vasoconstrictor with less detrimental local and systemic effects than epinephrine, the effects of phenylephrine, a pure alpha agonist, on tissue gas tension, bleeding, infection rates, and lidocaine absorption were studied. All concentrations of phenylephrine significantly reduced tissue PO2 within 10 minutes of injection, and reduction of PO2 was dose-dependent. Phenylephrine 1:10,000 produced significant bacterial growth when simultaneously injected with 6 X 10(6) Staphylococcus aureus. Bacterial growth was insignificant with 1:20,000 phenylephrine and absent with 1:40,000 phenylephrine. Blood loss from a standard wound was significantly reduced at all concentrations of phenylephrine. Lidocaine absorption was significantly reduced with 1:20,000 and 1:40,000 phenylephrine. In a rat model, 1:40,000 phenylephrine significantly reduced blood loss and lidocaine absorption, produced minimal reduction of tissue PO2, and did not enhance bacterial invasion.

Adsorption↗
PubMed1988

The diagnosis and classification of scleroderma (systemic sclerosis).

Difficulty in the diagnosis of the disease scleroderma may occur at the early stage prior to the development of obvious skin sclerosis. A presumptive diagnosis may be made if Raynaud's phenomenon is accompanied by a positive 'neck test', 'scleroderma' capillary changes in the nailfolds or antinuclear antibodies. Definitive diagnosis may have to be delayed for several years from the onset of Raynaud's phenomenon until definite characteristic skin changes are seen. Ten cases in which an earlier diagnosis of scleroderma was not substantiated are listed. The earlier incorrect diagnosis would have been avoided by use of the methods described in this paper. Various terms have been used to denote subdivisions of scleroderma. These include acrosclerosis, diffuse scleroderma and CREST. We have used the terms Type 1, Type 2 and Type 3 based on the early extent of the skin sclerosis where Type 1 (limited extent) indicates sclerodactyly only, Type 2 (moderate extent) indicates sclerosis proximal to the metacarpophalangeal joints but excluding the trunk and Type 3 (extensive) indicates diffuse skin sclerosis including the trunk. The clinical value of this simple classification is reviewed and contrasted to other classifications which appear to be poorly defined and of limited use.

Adult↗
PubMed1988

The role of substitutes in policy analysis: acute care services in state Medicaid programs.

Using four acute care equations (inpatient, physician, outpatient, and clinic) from a larger model of Medicaid, this research examines the "contents" of policy outcomes. This closer examination of outcomes brings to light the interactions between redistributive programs and services and the role of substitutes and complements in state-level policy analysis. (A substitute is a benefit or service that can be used instead of another to produce a similar outcome; a complement is a benefit or service that is likely to result in the use of another benefit or service.) Support is found for the inclusion of these theoretical constructs in policy analysis. Regarding Medicaid, the author concludes that physician, outpatient, and clinic services all complement hospital services; that physician and outpatient services substitute for one another; that state AFDC and SSI policy decisions have a greater impact on utilization than Medicaid-specific eligibility and service decisions do; and that the factors driving utilization (supply, demand, etc.) vary dramatically across acute care settings. The implications for Medicaid policymaking are also discussed.

Health Policy↗
PubMed1988

The influence of oestrogen and progesterone on the actions of two calcium entry blockers in the rat uterus.

The potency and maximum effect of the calcium entry blocker nifedipine as an inhibitor of uterine contractions in vivo are increased in rats in late pregnant compared with non-pregnant rats. The influence of ovarian steroids produced during pregnancy (oestrogen and progesterone) on the potency and maximum effect of two calcium entry blockers (nifedipine and diltiazem) against uterine contractions during i.v. infusion was therefore investigated in anaesthetized non-pregnant rats. The influence of pregnancy on the relationship between serum concentrations of diltiazem during i.v. infusion and uterine and cardiovascular effects was also investigated. A twofold increase in the potency of nifedipine as an inhibitor of uterine contractions was observed in rats treated with oestrogen or oestrogen plus progesterone compared with rats treated with corn oil. There was no change in potency in rats receiving progesterone alone. Maximum inhibition of uterine contractions by nifedipine was significantly increased by all three hormone treatments. A twofold increase in the potency of diltiazem and a significant increase in maximum inhibition of uterine contractions was observed in rats in late pregnancy compared with non-pregnant rats. No increase in potency of diltiazem in reducing blood pressure or heart rate was observed in rats in late pregnancy. No significant difference in potency of diltiazem against uterine contractions was observed in rats treated with oestrogen, progesterone or oestrogen plus progesterone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Distribution of Campylobacter pylori in the human stomach obtained at postmortem.

The distribution of Campylobacter pylori, its prevalence, and its relationship to gastritis and urease activity have been studied in 54 postmortem stomachs. Infection was confirmed by finding C. pylori in a Gram-stained smear of gastric mucus harvested from the entire stomach. Eight tissue specimens were obtained from predetermined sites from each stomach and examined for histologic gastritis and urease activity. Thirty-seven per cent of stomachs were infected, and of these 80% had widespread histologic gastritis. The detection of urease activity provided information on the distribution of the organism and had a high correlation with histologic gastritis. The organism is capable of infecting any area of the stomach. Infection is common and is more prevalent in Polynesian subjects (60%) than in Caucasians (19%).

Adolescent↗
PubMed1988

Predictions of dangerousness: an argument for limited use.

Intense debate has focused on the use of statistical predictions of dangerousness in the criminal justice system. Two conflicting positions maintain wide support: that such predictions are never appropriate in criminal justice decision-making, and that they should be used far more often. Recognizing the fact that implicit and intuitive predictions are made every day in police, prosecutorial, sentencing, and other decisions, and explicit but unscientific predictions are common, this article suggests a theoretical framework justifying limited use of statistical predictions. Statistical predictions may present, in some instances, a morally preferable alternative to biased nonscientific and implicit judgements. Development of a sound jurisprudence of predictions faces major hurdles given the trend toward unscientific predictions in the law and the enormous judicial confusion in dealing with predictions. The concept has contributed to a string of notably poor Supreme Court decisions.

Criminal Law↗
PubMed1988

Effects of triiodothyronine replacement on the anemia of chronic renal failure.

Patients and/or experimental animals with chronic renal failure have decreased serum levels of triiodothyronine (T3), a hormone well known for its erythropoietic activity. The following studies were designed in order to determine whether this observed abnormality in T3 metabolism is an important contributory factor to the etiology of the anemia of uremia. Groups of rats were made chronically uremic by a standard 5/6 nephrectomy technique and received slightly above physiological doses of T3 either by intermittent S.C. injections (twice daily) or by continuous infusion from intraperitoneally implanted osmotic minipumps. After 2 weeks of such treatment, and despite a normalization of serum T3 levels, there were no significant changes in the hematocrit, individual red cell mass, or serum erythropoietin levels of the uremic animals given T3 compared to control rats. We conclude that (1) the decreased serum T3 levels observed in uremia are not an important contributory factor to the pathogenesis of the anemia, and (2) treatment with replacement doses of T3 does not result in significant improvement of erythropoiesis.

Anemia↗
PubMed1988

Synthesis of soluble and insoluble elastins in cultures of chick aortic cells.

Aortic cells were isolated from 9- and 12-day embryonic chick aortas and cultured for varying periods after first passage. Cells obtained from 9-day tissue remained indefinitely as monolayers and possessed a relatively low rate of tropoelastin synthesis. Cells obtained from 12-day tissue remained monolayers for 4 to 8 days, after which time portions of the culture contracted into matrix containing chemically definable insoluble elastin and forming desmosine cross-links. The rate of tropoelastin synthesis was significantly higher in the 12-day derived cells suggesting that these cells had been committed to elastogenesis in vivo and retained this commitment in vitro. A chick tropoelastin cDNA was obtained and partially characterized from a lambda gt11 expression cDNA library. Using the tropoelastin cDNA probe, measurement of the steady-state level of tropoelastin revealed that the increased rate of tropoelastin synthesis in the 12-day cells was accompanied by a significant increase in the level of tropoelastin mRNA steady-state levels. The aortic cell cultures present an important model system for extending studies of chick aortic elastogenesis. The aortic cell cultures synthesize tropoelastin at a rate 10% less than the corresponding organ culture. Significantly, the production of tropoelastin is productive in formation of insoluble, chemically definable elastin. The definition of insoluble includes both amino acid composition and desmosine formation.

Amino Acids↗
PubMed1987

Association between mortality among women and socioeconomic factors in general practices in Edinburgh: an application of small area statistics.

Women aged 45-64 in 78 general practices in the city of Edinburgh were followed up for five to seven years and all cause mortality noted. Standardised mortality ratios were calculated for the individual practices. Postcodes were available for a 20% sample of these women and were used to retrieve relevant measures of social class and deprivation from the 1981 census for the smallest division, the enumeration district. Weighted averages gave socioeconomic variables at the level of the general practice. High positive correlations were found between standardised mortality ratios and the socioeconomic variables, with the highest being for percentage overcrowding. This study established that the relation between deprivation and excess mortality can be shown in general practices in one large city and gave a direct relation for women without reference to their husbands' occupations, thus obviating problems of assigning social class. The data also partially refute the "social drift" hypothesis as an explanation of the association between mortality and social class.

Female↗
PubMed1987

Crystallization of a DNA duplex 15-mer containing unpaired bases: d(CGCGAAATTTACGCG).

Crystals of an almost self-complementary DNA 15-mer d(CGCGAAATTTACGCG) have been grown by the vapor diffusion technique at 4 degrees C. The space group is I222 with a = 37.3 A, b = 54.6 A and c = 104.8 A. Solution studies showed that the 15-mer forms a duplex with the extra adenine residue unpaired: (sequence; see text) Crystals are stable at 4 degrees C and are suitable for medium-resolution structural studies.

Base Sequence↗
PubMed1987

Conformational transitions of synthetic DNA sequences with inserted bases, related to the dodecamer d(CGCGAATTCGCG).

Conformational transitions for a series of imperfect palindromes related to the dodecamer d(CGCGAATTCGCG) have been investigated. These sequences are: two isomeric 13-mers - d(CGCAGAATTCGCG) (13-merI) and d(CGCGAATTACGCG) (13-merII), 17-mer d(CGCGCGAATTACGCGCG) and 15-mer d(CGCGAAATTTACGCG). Insertion of a single adenine nucleotide prevents these sequences from being self-complementary. Analysis of thermodynamic parameters derived from the melting profiles together with other data at higher concentrations (NMR and calorimetry) indicates that the insertion of the additional nucleotide which lacks a complement in the opposite strand does not change the enthalpy of the duplex formation, but does alter the number of stable nucleation configurations. The relative position of the insertion within the self-complementary sequence determines the equilibrium between the duplex form and the single-stranded hairpin loop. C-G segments separated by the insertion from the rest of the molecule can undergo an independent conformational transition at high salt concentration, probably to the Z form.

Base Sequence↗
PubMed1987

Nocturnal plasma prolactin and cortisol levels in epileptics with complex partial seizures and primary generalized seizures.

The nocturnal pattern of plasma prolactin (PRL) and cortisol in male epileptics with complex partial seizures and primary generalized seizures was studied by all-night polygraphic recordings with continuous video monitoring and sequential blood sampling at 30-minute intervals. Mean nocturnal plasma PRL concentrations in both groups of epileptics were significantly elevated when compared with nonepileptic control subjects studied in a similar fashion. Eight subclinical and three clinical partial seizures were recorded during sleep. Although a tenfold increase of plasma PRL level occurred following a short brief clinical complex partial seizure, there was no direct correlation between single subclinical partial seizures and nocturnal fluctuations of plasma PRL concentrations. We did not observe recognizable plasma cortisol changes following partial seizures during sleep, nor significant differences of mean nocturnal plasma cortisol levels between epileptics and controls. The data obtained in this environmentally controlled study indicate that postictal elevation of plasma PRL is a specific phenomenon related to seizure discharges; however, failure of such a rise does not exclude partial seizures.

Adult↗
PubMed1987

A comparative trial of moxalactam plus ticarcillin and clavulanic acid or piperacillin as empiric antibiotic therapy for febrile cancer patients.

Resistance of bacteria to beta-lactam antibiotics remains a difficult clinical problem that can be compounded in infected patients with serious underlying illness, especially those who are immunocompromised. In a prospective randomized safety and efficacy trial, febrile cancer patients received either ticarcillin disodium combined with the beta-lactamase inhibitor clavulante potassium (Timentin, Beecham Laboratories, Bristol, TN) plus moxalactam (T+M), or piperacillin plus moxalactam (P+M) as initial empiric antimicrobial therapy. Sixty-six febrile episodes in 53 patients were studied. In the T+M group, 14 (78%) of 18 clinically evaluable infections in patients with profound granulocytopenia improved as did all 14 (100%) such infections in the P+M group. In the T+M group 17 of 21 (81%) similarly evaluable infections improved irrespective of granulocyte count, as did 14 (88%) of 16 of such infections in the P+M group. These results are not statistically significantly different. Serious side effects were infrequent and comparable with both regimens. There was one antibiotic related hemorrhage in the P+M group and a serious episode of nephrotoxicity in a patient who died without recovering renal function in the T+M group. These results suggest that the overall safety and efficacy of Timentin plus moxalactam, and piperacillin plus moxalactam are comparable and similar to previous empiric antibiotic trials.

Bacterial Infections↗
PubMed1987

Mueller maneuver and LV function in coronary artery disease.

Decreasing pleural pressure impedes the ejection of blood from the left ventricle (LV), may lead to decreased LV compliance because of interdependence effects and leads to increased transmural LV systolic and diastolic pressure. Previous work from this laboratory has shown that patients with coronary artery disease (CAD) often develop akinetic segments of the LV wall during the Mueller maneuver. In the presence of increased LV transmural pressure regional akinesis could be caused either by the development of regional ischemia or by mechanical inhibition of motion of an area of nonfunctional myocardium as would be caused by previous myocardial infarction (MI). The present study was designed to distinguish between these two mechanisms by determining if the presence of CAD alone is sufficient to lead to regional akinesis or if prior MI is necessary. We used first pass radionuclide ventriculography (RVG) in the 30 degrees LAD supine position to measure LV ejection fraction (EF), end-diastolic (EDV) and end-systolic (ESV) volumes, heart rate and to assess regional wall motion during the Mueller maneuver. This was done in four groups of subjects: 13 normal subjects, 25 patients with CAD but no prior MI, 13 patients with prior nontransmural MI and 36 patients with prior transmural MI. All subjects had angina pectoris and underwent contrast coronary arteriography. Most also underwent routine contrast left ventriculography as well. There were no significant differences among the three patient groups as regards medications, extent and severity of CAD, and response to routine exercise tolerance testing. EF decreased significantly in the three patient groups (4%-9%, p less than 0.01) but not in the normals during the Mueller maneuver. Heart rate increased (5-10 bpm, p less than 0.05) in the normals and in patient groups 2 and 4. EDV decrease in all four subject groups (8%-10%, p less than 0.01), while ESV remained unchanged. Akinesis of the LV wall developed during the Mueller maneuver only in one group-2 patient, but did so in 17/36 patients with prior transmural MI (group 4, p less than 0.001). One-half of the akinetic LV wall segments seen during the Mueller maneuver on RVG were not seen on routine contrast ventriculography. We tested the effects of posture (supine versus upright) on the response to the Mueller maneuver in six normal subjects and found no changes in the response of EDV and ESV to the Mueller maneuver.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Disease↗
PubMed1987

Malassezia furfur skin colonization of infants hospitalized in intensive care units.

We studied the prevalence of Malassezia furfur skin colonization of infants hospitalized in our neonatal and infant cardiac and surgical intensive care units by culturing at monthly intervals. Of 361 infants studied over 1 year, 133 (36.8%) had at least one positive culture for M. furfur. Colonized infants, compared with noncolonized infants, had younger mean gestational age (32.4 vs 35.2 weeks, P less than 0.01), lower mean birth weight (1.76 vs 2.31 kg, P less than 0.01), a longer stay in hospital (Wilcoxon P less than 0.01), and more mean days use of an incubator (12.7 vs 7.6 days, P less than 0.01), lamb wool (12.9 vs 8.2 days, P less than 0.01), paper tape (10.8 vs 8.2 days, P less than 0.01), and Op-Site tape (14.1 vs 10.1 days, P less than 0.01). These data suggest that hospitalization in an infant intensive care unit often leads to M. furfur colonization. Although frequent adult handling may be a source, other aspects of intensive care will require careful scrutiny to define more completely the risk factors leading to M. furfur colonization of ill infants.

Birth Weight↗