PubMed Health⌕ Search

Biomedical subjects

M A Evans

Publications and source records attributed to M A Evans.

At least 37 records · Page 2Linked to original sources
PubMed1998

Generalizability in pregnancy and work research.

Generalizability of findings is a critical issue in research on pregnancy and work. The characteristics of a sample of 350 pregnant military women were compared with those of the populations of active duty women and active duty pregnant women. The sample was fairly representative in terms of minority status and age. The sample differed somewhat in terms of branch of service, rank, and marital status. Comparisons of demographics and pregnancy planning between military and civilian pregnant women supported generalizability. Unique aspects of military service and different access to health care among civilian pregnant women warrant caution in generalizing of findings.

Adult↗
PubMed1997

Pregnancy planning and the impact on work climate, psychological well-being, and work effort in the military.

This study examined the joint effects of demographics and pregnancy planning and timing on work climate, psychological well-being, and work effort among 345 pregnant U.S. military women from the Army, Navy, Air Force, and Marines. Rank predicted both pregnancy planning and career timing. Pregnancy planning was positively associated with support from coworkers and supervisors and with enhanced work effort and psychological well-being. Pregnancy timing was positively associated with support from supervisors, reduced harassment, and increased psychological well-being. Rank interacted with the planning and timing measures. Junior officers and enlisted participants reported reduced command and pregnancy support and increased harassment in conjunction with poorly timed pregnancies.

Adaptation, Psychological↗
PubMed1995

Effect of low dose aspirin on cardiorenal function and acute hemodynamic response to enalaprilat in a canine model of severe heart failure.

OBJECTIVES: This study examined the effect of low dose aspirin on cardiorenal and neurohumoral function and on the acute hemodynamic response to enalaprilat in a canine model of heart failure. BACKGROUND: Low dose aspirin is frequently prescribed for patients with systolic dysfunction who also benefit from angiotensin-converting enzyme inhibition. Although high doses of potent cyclo-oxygenase inhibitors cause fluid retention and vaso-constriction and antagonize the effects of angiotensin-converting enzyme inhibitors, the effects of low dose aspirin in heart failure are unknown. METHODS: A model of heart failure was produced in 11 mongrel dogs by rapid ventricular pacing (250 beats/min for 12 to 14 days). Five dogs received 325 mg aspirin/day for the final 4 days of pacing before the acute experiment; six control dogs received no aspirin. Cardiorenal and neurohumoral function was measured during chloralose anesthesia. Hemodynamic and renal responses to enalaprilat were assessed. RESULTS: Both groups demonstrated severe heart failure with decreased cardiac output; increased atrial pressures and systemic resistance; activation of plasma renin activity, aldosterone and atrial natriuretic factor; and sodium retention. Low dose aspirin had no detrimental effect on cardiorenal or neurohumoral function. Mean arterial pressure, pulmonary capillary wedge pressure and systemic vascular resistance decreased to a similar degree with enalaprilat in both groups. There was no difference between the groups with respect to renal response to enalaprilat. CONCLUSIONS: The present study demonstrates that low dose aspirin has no adverse effect on hemodynamic, neurohumoral or renal function in heart failure. Furthermore, aspirin has no adverse effect on the acute response to enalaprilat. These findings suggest that there is no contraindication to concomitant treatment with low dose aspirin and angiotensin-converting enzyme inhibitors in humans with heart failure.

Aldosterone↗
PubMed1995

Inhibition of rabbit aortic smooth muscle cell proliferation by selective inhibitors of protein kinase C.

1. We studied the effect of two structurally-related, selective inhibitors of protein kinase C, Ro 31-8220 and Ro 31-7549, on the reinitiation of proliferation in quiescent first passage rabbit aortic smooth muscle cells in response to (a) the direct activator of protein kinase C, phorbol dibutyrate (PDBu), (b) platelet-derived growth factor (PDGF), (c) a combination of PDGF and 5-hydroxytryptamine (5-HT) or (d) serum. 2. Ro 31-8220 and Ro 31-7549 concentration-dependently inhibited proliferation in response to each mitogen. The inhibitory potency (IC50) of Ro 31-8220 and Ro 31-7549, respectively, was similar against proliferation induced by PDBu (0.55 and 1.1 microM), PDGF (0.6 and 0.9 microM), PDGF and 5-HT (0.68 and 1.1 microM), although slightly less against serum (1.7 and 5 microM). The effects of the protein kinase C inhibitors on proliferation could not be ascribed to cytotoxicity. Neither Ro 31-8220 nor Ro 31-7549 (0.3-3 microM) inhibited PDGF receptor tyrosine phosphorylation. 3. The results show that Ro 31-8220 and Ro 31-7549 are potent inhibitors of smooth muscle cell proliferation in response to a direct activator of protein kinase C, the defined growth factors, PDGF and 5-HT, and the complex mixture of mitogens in serum. Protein kinase C activation thus appears to be an important growth transducing mechanism for each of these agents.

Animals↗
PubMed1995

Home nutrition support materials.

The provision of enteral and parenteral nutrition to patients in the home setting continues to be an expanding area of practice throughout the US and Canada. The need for specialized training of patients and family members to safely administer these nutrition therapies at home following hospital discharge also continues to grow. In 1993, written materials designed for this purpose were gathered from institutions throughout the US and listed in a directory of Home Nutrition Support Patient Education Materials. Many nutrition support teams and health care organizations have been undergoing reorganization and streamlining during the past several years. As a result, resources for the creation and distribution of home nutrition support (HNS) education materials are diminished in many areas. An updated version of this directory has therefore been compiled to facilitate the exchange of these training items between institutions and teams across the country.

Enteral Nutrition↗
PubMed1994

An investigation into the feasibility of parental participation in the nursing care of their children.

Family-centred care has been recognized as a basic tenet of paediatric nursing for some time because it is believed that children benefit from the continuous presence of their patents. It is for this reason that the concept of care by parents has evolved. Although such a philosophy is beneficial for the child, it has undoubtedly evolved due to low staffing levels, and in such an environment the guidelines for safe practice are easily called into question. In the wake of a new paediatric oncology ward, it was decided to consider instituting care by parents. In an effort to do this in a structured way, it was decided to make our practice research based. A teaching tool was formulated and five mothers who presented consecutively to the paediatric oncology ward were taught how to administer intravenous antibiotics to their child. Mothers' views on the teaching programme were sought using taped interviews, and the data were analysed using grounded theory. This methodology allowed a theoretical framework based on realistic data to emerge, and the resultant themes provided a valuable insight into mothers' views on the subject. It emerged that nurses' attitudes towards care by parents require clarifying and that changes need to take place if this concept is to be taken on board. Negotiation to allow mutual understanding between parents and nurses is essential to the successful implementation of such a scheme.

Adaptation, Psychological↗
PubMed1994

CATCH: food service program process evaluation in a multicenter trial.

Process evaluation is an essential element of a multicenter trial in order to explain study outcomes and monitor intervention progress. This paper presents the process evaluation model for the Eat Smart School Nutrition Program, the food service intervention component of the Child and Adolescent Trial for Cardiovascular Health (CATCH), and describes the process evaluation strategies developed to assess this program. The paper details (1) measures of program implementation including training, support visits, and program promotion, (2) food service staff characteristics, and (3) measures of mediating variables including secular trends and school meal participation.

Adolescent↗
PubMed1994

Bias reduction for multiple-recapture estimators of closed population size.

A bias correction for multiple-recapture sampling is proposed. The correction is similar to Chapman's (1951, University of California Publication in Statistics 1, 131-160) correction of the Lincoln-Petersen estimator of population size. Small-sample properties of the modified population size estimator are examined using Monte Carlo simulation. Substantial reductions in estimator bias and variance are obtained with the modified estimator.

Animal Identification Systems↗
PubMed1994

A general theory for modeling capture-recapture data from a closed population.

A general theory for estimating the size of a closed population from multiple-recapture data is presented. This theory is easily extended to open population models for multiple-recapture data. Estimation is based on a log-linear model developed for modeling dependent capture-recapture data when capture probabilities vary temporally with behavioral response and are heterogeneous among animals. Models for complete capture history data are developed along with the first log-linear models for removal data. The maximum likelihood estimator of the model parameters along with the estimated covariance matrix are presented.

Animal Identification Systems↗
PubMed1993

Home nutrition support patient education materials.

The practice of providing specialized enteral and parenteral nutrition to patients in the home setting has expanded nationwide during the past decade. Accompanying this growth has been an increased need for education of patients, families, and care providers in techniques of administering intravenous and tube feedings safely after discharge from the hospital. To meet this demand for information, written home nutrition support (HNS) education materials have been developed by hospital nutrition support teams, patient education specialists, home care providers, and formula manufacturers. The time and financial costs of developing these materials may be prohibitive in certain institutions that need HNS education resources. A directory of the printed materials available has been compiled to facilitate communication and exchange of HNS education information among institutions. The directory is presented with this article, with important characteristics to consider in the development of HNS education materials.

Enteral Nutrition↗
PubMed1992

Relapsing hairy cell leukemia presenting as fulminant hepatitis.

PURPOSE: We report the first known case of fulminant hepatitis due to hairy cell infiltration. CASE REPORT: A 43-year-old woman with hairy cell leukemia returned 1 year after diagnosis with spider angiomata of the face and neck, palmar erythema, and diffuse telangiectasias. The liver span was normal. Laboratory studies included: aspartate aminotransferase, 56 U/L; alkaline phosphatase, 283 U/L; gamma-glutamyltransferase, 157 U/L; and normal bilirubin. A liver biopsy demonstrated modest infiltration of hairy cells with hemosiderosis and intact hepatocytes. RESULTS: The patient responded to interferon-alpha with resolution of the angiomata, decreased palmar erythema, and improved liver function tests. Five months later, she presented with right upper quadrant pain, anorexia, fatigue, and diffuse myalgias. The physical examination was unchanged. Laboratory studies included: aspartate aminotransferase, 299 U/L; alkaline phosphatase, 1,388 U/L; total bilirubin, 43 mumol/L; and direct bilirubin, 29 mumol/L. Two weeks later, she was admitted to the hospital. Her liver span was 15 cm. Laboratory studies showed the following values: aspartate aminotransferase, 618 U/L; alkaline phosphatase, 2,319 U/L; total bilirubin, 311 mumol/L; direct bilirubin, 233 mumol/L; and alanine aminotransferase, 462 U/L. Intensive investigation of contributing causes was not revealing. A subsequent liver biopsy demonstrated extensive portal and intralobular hairy cell infiltration with loss of normal architecture. Liver function deteriorated as shown by the following values: aspartate aminotransferase, 1,100 U/L; alkaline phosphatase, 3,645 U/L; bilirubin, 477 mumol/L; and ammonia, 47 mumol N/dL. The patient died 9 days after admission. CONCLUSIONS: Although liver infiltration is often present and mild elevations of liver function tests have been noted, evidence of such extensive hepatic injury caused by hairy cell leukemia has not been reported previously. Hairy cell infiltration of the liver can cause typical cutaneous changes of liver disease and even fulminant hepatitis.

Acute Disease↗
PubMed1992

Outcome of noncardiac operations in patients with severe coronary artery disease successfully treated preoperatively with coronary angioplasty.

The risk of perioperative myocardial infarction and death was evaluated in 50 patients (mean age, 68 years) with severe coronary artery disease who underwent a noncardiac operation after revascularization had been achieved by successful percutaneous transluminal coronary angioplasty. Before angioplasty, all patients were thought to be at high risk for perioperative complications on the basis of assessment of clinical variables and findings on specialized diagnostic tests. Of the 50 patients, 31 had Canadian Heart Association class III or IV angina or unstable angina. All patients who underwent functional testing had positive results. At catheterization, 38 patients (76%) had multivessel disease. The 50 patients underwent 54 noncardiac operations at a median of 9 days after angioplasty. The overall frequency of perioperative myocardial infarction was 5.6%, and the mortality was 1.9%. Two nonfatal non-Q-wave infarctions and one fatal Q-wave infarction occurred. In patients who have undergone successful angioplasty for severe coronary artery disease, the risk of major cardiac complications associated with a noncardiac surgical procedure is low.

Aged↗
PubMed1992

Balance studies and polymeric glucose solution to optimize therapy after massive intestinal resection.

The aim of this study was to determine whether fluid homeostasis could be maintained by using a hypo-osmolar (200 to 221 mosmol/kg), relatively low-sodium (50 to 52 mmol/liter) solution that contained a glucose polymer in a 54-year-old patient with high ileostomy output attributed to short-gut syndrome and resultant prerenal azotemia. Sequential balance studies were performed to assess stool and urinary output, stool fat, and urinary electrolytes initially during intravenous rehydration and subsequently during administration of the necessary fluids and nutrients exclusively by oral supplementation. The additional effects of high-fat and low-fat diet, loperamide hydrochloride, and octreotide acetate were evaluated. When the patient sipped a hypo-osmolar oral rehydration solution while she was awake during the day and received a high dose of loperamide and a 40-g fat, disaccharide-free diet, salt and water homeostasis was maintained. The addition of octreotide did not substantially enhance fluid balance; rather, it increased fecal fat and fluid losses from the small bowel. Thus, hypo-osmolar polymeric glucose solutions maintain fluid homeostasis in patients with the short-gut syndrome. In such patients, simple balance studies are useful for assessing the absorptive capacity of the residual intestine, for developing an optimal individualized treatment, and for eliminating the need for costly, long-term home parenteral nutrition.

Crohn Disease↗
PubMed1992

Total lymphoid irradiation: a novel and successful therapy for resistant cardiac allograft rejection.

Total lymphoid irradiation (TLI) is a novel type of adjuvant immunosuppression for patients who undergo cardiac transplantation and have refractory allograft rejection during standard immunosuppressive therapy. TLI consists of 6 to 10 fractions of 80 cGy (1 cGy = 1 rad) of irradiation to lymphatic tissues with use of the standard mantle and inverted Y fields. We have used TLI in six patients with biopsy-proven rejection that was refractory to standard treatments, including cyclosporine, azathioprine, antilymphocyte antibodies, and corticosteroids. In five patients, recalcitrant rejection was resolved after completion of TLI, and resolution persisted during long-term follow-up (17 to 30 months; mean, 22.2 months). In each patient, a substantial increase in the CD8 (suppressor T-lymphocyte) subset and elimination of B lymphocytes were demonstrated, findings that also persisted. Side effects were mild and primarily limited to transient leukopenia. In four patients, a readily treated cytomegalovirus reactivation was noted during TLI; thus, a causal relationship was suggested. In recipients of cardiac allografts who have refractory rejection, TLI provides long-lasting amelioration of the rejection profile. This result may be attributable to a relative enhancement of the suppressor T-cell subset and elimination of the B-lymphocyte line. Side effects are minimal, but monitoring for cytomegalovirus activation or reactivation is recommended.

Adult↗
PubMed1992

Intestinal fuels: glutamine, short-chain fatty acids, and dietary fiber.

In recent years, considerable research has focused on the physiologic effects and clinical uses of three dietary constituents thought to be trophic to the intestinal tract in human beings: glutamine, short-chain fatty acids (SCFAs), and dietary fiber. Glutamine is an important nitrogen-carrying amino acid that may be "conditionally essential" in certain disease states to support the gut barrier and immune function and overall protein use. Colonic irrigations with SCFA preparations have demonstrated enhanced healing of bowel tissue in animals and human beings. Dietary fiber supports bacterial SCFA production, normal stool output, and the gut barrier and immune function. However, optimal fiber doses for various medical conditions are not known, and the risk for gastrointestinal (GI) obstruction, diarrhea, gas, and bloating necessitates careful selection of patients and daily monitoring of fiber tolerance. A review of the current literature indicates that widespread use of glutamine and SCFA additives parenterally and enterally awaits further evidence of safety and efficacy in human beings, establishment of appropriate doses, and advances in formulation technology. Administration of dietary fiber to enhance bowel motility should be considered in long-term tube-fed patients with intact GI function and sufficient fluid tolerance to permit hydration of fiber. Industrywide agreement on fiber analysis methods and labeling standards (eg, fiber fermentability vs solubility) would facilitate selection of enteral products. To streamline studies and optimize research efforts in future clinical trials, standard criteria for evaluating GI function, diarrheagenic factors, and intestinal outcome variables should be established.

Animals↗