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Biomedical subjects

C M Murphy

Publications and source records attributed to C M Murphy.

At least 55 records · Page 3Linked to original sources

Structure and time-dependent behavior of acetylated and non-acetylated forms of a molluscan metallothionein.

Cadmium-induced metallothionein in a mollusc, the oyster Crassostrea virginica, occurs in both blocked and unblocked forms (Roesijadi, G., Kielland, S.L. and Klerks, P. (1989) Arch. Biochem. Biophys. 273, 403-413). The block, which is the sole difference in the structure of the two proteins, was identified as an acetyl group with use of tandem mass spectrometry. The blocked and unblocked proteins carried N-acetylserine and serine, respectively, at the N-terminus and were designated CvNAcMT and CvMT. Only CvNAcMT was detected under basal conditions. Both forms were induced by Cd. Pulse-labeling with [35S]cyteine at specified times during exposure showed that the rate of CvNAcMT synthesis in gills increased rapidly, initially exceeding that of CvMT, then declined to the rate attained by CvMT. Turnover rates for Cd-induced CvMT and CvNAcMT were similar to each other. They appeared to be faster when measured in the absence of Cd in the external medium (k = 0.18 and 0.16/day, respectively), than in its presence (k = 0.03 and 0.06/day, respectively).

Acetylation↗

Treatment of asthma in children.

The epidemiology, etiology and pathophysiology, clinical presentation and diagnosis, and drug therapy of asthma in children are reviewed. Recent advances in drug therapy have, for unknown reasons, been accompanied by an increase in the morbidity and mortality associated with childhood asthma. The cause of asthma is not precisely understood, but an inflammatory process and hyperactivity of airways are common findings in the disease. Asthma in children can be classified as intermittent, chronic, or indeterminate; a severe, prolonged episode not relieved by usual treatment is called status asthmaticus. The hallmark symptoms of asthma are coughing, dyspnea, and wheezing. Beta-adrenergic agonists can be used orally for diagnostic purposes or for nocturnal asthma; i.v. or s.c. for emergency treatment; or by inhalation for relief of acute asthmatic episodes. Experience with anticholinergics in children is limited, and these agents should be used only when other options have failed. Inhalation of cromolyn sodium is very safe and is useful for the prophylactic treatment of mild to moderate asthma. Corticosteroids, which are used both for acute asthmatic episodes and for long-term treatment, can be given orally, i.v., or by inhalation. Theophylline is used for prophylactic therapy in children with chronic asthma. Selection of a drug regimen is based on knowledge of efficacy, pharmacokinetics, compliance, and toxicity. The treatment of asthma in children requires consideration of drug properties in young patients. Drugs used to treat childhood asthma include beta agonists, anticholinergics, cromolyn sodium, corticosteroids, and theophylline.

Administration, Inhalation↗

Marital adjustment, parental disagreements about child rearing, and behavior problems in boys: increasing the specificity of the marital assessment.

2 studies were conducted to illustrate how measuring a specific aspect of marriage, namely, child-rearing disagreements, provides a better understanding of the link between marriage and boys' behavior. In Study 1, 200 mothers of 3-year-old boys completed unstandardized measures of marital functioning and child behavior. An index of child-rearing disagreements: (1) correlated with a greater variety of behavior problems than nonchild disagreements, and (2) improved upon the prediction of behavior problems after accounting for nonchild disagreements as well as after accounting for boys' exposure to marital conflict. In Study 2, 87 mothers with 4-6-year-old sons completed the index of child-rearing disagreements used in Study 1 as well as standard measures of marital functioning and child behavior. Child-rearing disagreements: (1) predicted a greater variety of behavior problems than global marital adjustment, and (2) improved upon the prediction of internalizing problems after controlling for global marital adjustment as well as after controlling for boys' exposure to marital conflict.

Adaptation, Psychological↗

Recognition of trypsin autolysis products by high-performance liquid chromatography and mass spectrometry.

Potential artifactual contributions are assessed in high-pressure liquid chromatograms and fast atom bombardment mass spectra from autolysis of different preparations of the widely used protease trypsin. Both commercially supplied and laboratory-purified samples were examined. Bovine pancreatic trypsin (1 mg/mL) was found to be completely destroyed in 2 h at pH 8.5, degraded to a complex mixture of small peptides which were characterized by their molecular weights. Some identifications were supported by sequencing by tandem mass spectrometry or by mass spectrometric analysis of the mixture resulting from a single Edman degradation. Autolysis of porcine pancreatic trypsin produced a completely different set of peptides. Five sites of hydrolysis at asparagine residues in bovine trypsin were also identified.

Amino Acid Sequence↗

Acetoacetyl-acyl carrier protein synthase. A target for the antibiotic thiolactomycin.

The biochemical basis for the inhibition of fatty acid biosynthesis in Escherichia coli by the antibiotic thiolactomycin was investigated. A biochemical assay was developed to measure acetoacetyl-acyl carrier protein (ACP) synthase activity, a recently discovered third condensing enzyme from E. coli (Jackowski, S., and Rock, C.O. (1987) J. Biol. Chem. 262, 7927-7931). In contrast to the other two condensing enzymes in E. coli, acetoacetyl-ACP synthase (synthase III) condensed malonyl-ACP with acetyl-CoA, rather than with acetyl-ACP. The concentration dependence of thiolactomycin inhibition of fatty acid biosynthesis in vivo was the same as the inhibition of acetoacetyl-ACP synthase activity in vitro indicating that the two phenomena were related. A thiolactomycin-resistant mutant (strain CDM5) was isolated. The specific activity of acetoacetyl-ACP synthase in extracts from this mutant was 10-fold lower than in extracts from its thiolactomycin-sensitive parent resulting in a marked defect in the ability of strain CDM5 to incorporate acetyl-CoA into fatty acids in vitro. The residual acetoacetyl-ACP synthase activity in the resistant strain was refractory to thiolactomycin inhibition. In addition, acetyl-CoA:ACP transacylase activity in strain CDM5 was resistant to inactivation by thiolactomycin suggesting that the acetoacetyl-ACP synthase also catalyzes this transacylation reaction. These data point to acetoacetyl-ACP synthase as a target for thiolactomycin inhibition of bacterial fatty acid biosynthesis.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗

A micro-kininogenase assay for studies of kallikrein in renal micropuncture/microperfusion.

We report the development of a micro-kininogenase assay suitable in studying the dynamics of kallikrein at intranephron segmental level. The detection limit is 119 fg or 2.6 attomoles of kallikrein. Activation of microquantities of kallikrein is possible with the use of Triton X-100. Because of its extremely high sensitivity and reproducibility the assay is likely to also prove useful in physiological studies in which only very small amounts of kallikrein containing samples can be obtained.

Animals↗

Effects of maternal mood on mother-son interaction patterns.

This study evaluated the impact of maternal mood on mother-son interaction patterns. Forty boys between the ages of 46 and 72 months and their mothers participated. A within-subject experimental design was employed so that all mothers participated in both a positive and a negative mood induction. Observations of mother-son interactions were conducted immediately following the mood inductions. During the negative mood condition, mothers issued fewer positive statements toward their children and engaged in less general verbal interaction. In addition, children were less complaint with maternal commands during the negative mood condition. Implications of the effects of mood on mother-child interaction patterns are discussed.

Adult↗

Interspousal aggression, marital discord, and child problems.

The association between interspousal aggression and child problems was assessed after controlling for parents' general marital discord. Participants were 87 couples requesting marital therapy who had children between 5 and 12 years old. Spouses completed measures of marital aggression, marital discord, child problems, and family demographics. Marital aggression contributed unique variance to the prediction of conduct disorder, personality disorder, inadequacy-immaturity, and clinical levels of problematic child behavior after marital discord, child's age, child's sex, and Marital Discord X Child's sex interaction were controlled. The theoretical implications of these findings are discussed.

Adult↗

Psychological aggression predicts physical aggression in early marriage.

Psychological aggression by self and partner, physical aggression by the partner, and marital dissatisfaction were examined as longitudinal predictors of first instances of physical aggression during marriage. Subjects who were not physically aggressive at a premarital assessment were selected from a sample of 393 engaged couples. Couples participated in three subsequent assessments over the first 30 months of marriage. As hypothesized, individuals' own psychological aggression predicted their initial incidents of physical aggression in marriage. Psychological aggression by their partners also predicted initial incidents of physical aggression. Prior physical aggression by their partners was inconsistently associated with first instances of physical aggression. Contrary to our hypothesis, previous levels of marital dissatisfaction did not predict initial incidents of physical aggression. These findings were consistent across sexes. The results underscore the progression from psychological to physical abuse and have clear implications for understanding the development and prevention of interspousal aggression.

Adult↗

Clearance of beta-2-microglobulin using continuous ambulatory peritoneal dialysis.

In the 9 continuous ambulatory peritoneal dialysis (CAPD) patients studied, the mean clearance of beta 2-microglobulin was significantly higher using hypertonic as opposed to isotonic exchanges (1 ml/min and 0.75 ml/min, respectively). Clearance of beta 2-microglobulin correlated with the clearance of albumin. The daily mass transfer of beta 2-microglobulin ranged from 19 to 62 mg. Although all the daily production of beta 2-microglobulin is not eliminated in patients on CAPD their serum beta 2-microglobulin levels would be expected to be lower than in patients on haemodialysis. Long-term prospective studies are needed to determine whether lower serum beta 2-microglobulin levels lead to a lower incidence of dialysis amyloid.

Ascitic Fluid↗

Improved cost allocation in case-mix accounting.

Traditionally, many hospital costs have been allocated to patients using indirect measures that do not always reflect the value of the resources used to provide care. When, for example, costs are allocated by multiplying the patient's charges by the hospital's ratio of costs to charges, the allocated cost does not reflect actual cost because the hospital does not uniformly charge for services in proportion to their cost. The choice of method for cost allocation will be as important for the newly developed case-mix cost-accounting systems as it has been for traditional cost-accounting systems. To illustrate how the use of an indirect cost-allocation method might affect the output of a case-mix cost-accounting system, operating room, radiology and clinical laboratory costs were assigned to 106 hospitalized inguinal hernia patients in two diagnosis-related groups (DRGs) using both the hospital's existing cost-allocation method and a method that measures costs directly. Total costs and the costs in each department were significantly lower in each DRG using the direct method. It was concluded that patients in these two DRGs were being assigned more than the actual cost of their care with the existing cost-allocation method and, therefore, that the existing method prevented the case-mix accounting system from providing accurate management information.

Accounting↗

Relationships between certification and job perceptions of oncology nurses.

PURPOSE/OBJECTIVES: To explore relationships between oncology nursing certification and oncology nurses' job perceptions. DESIGN: Descriptive, correlational. SETTING: Questionnaire mailed to homes of Oncology Nursing Society (ONS) members. SAMPLE: 703 certified and 514 noncertified ONS members (N = 1,217; 50% response rate). METHODS: Data were collected using survey methods and grouped by respondents' certification status for statistical analysis. MAIN RESEARCH VARIABLES: Certification, group cohesion, organizational commitment, and job satisfaction. FINDINGS: Certification was weakly correlated with cohesion, commitment, and satisfaction. Work setting, rather than certification, accounted for differences in job perceptions. Job perceptions were most positive in settings characterized by a high percentage of patients with cancer (> 75%), a high percentage of RNs (> or = 80%), and monetary support for continuing education. CONCLUSIONS: The hypothesis that oncology nurses' certification status is associated with job perceptions that are valued by employers was not supported. IMPLICATIONS FOR NURSING PRACTICE: Nurses' job perceptions have been linked to control over nursing practice and participation in organizational and clinical decision making. Managerial strategies that empower certified nurses to practice with more autonomy and participate in decisions that affect patient care should be emphasized.

Adult↗