PubMed Health⌕ Search

Biomedical subjects

D A Raines

Publications and source records attributed to D A Raines.

At least 19 recordsLinked to original sources
PubMed2001

Expedient liquid chromatographic method with fluorescence detection for montelukast sodium in micro-samples of plasma.

This study describes an expedient assay for the analysis of the asthma medication, montelukast sodium (Singulair, MK-0476), in human plasma samples. After a simple extraction of the plasma, the drug and internal standard, quinine bisulfate, were measured by HPLC. The chromatographic system consisted of a single pump, a refrigerated autosampler, a C8 4-microm particle size radial compression cartridge at 40 degrees C and a fluorescence detector with the excitation and emission wavelengths set at 350 and 400 nm, respectively. The mobile phase which was delivered at 1.0 ml/min, was prepared by adding 200 ml of 0.025 M sodium acetate, pH adjusted to 4.0 with acetic acid, to 800 ml of acetonitrile, with 50 microl triethylamine. With a run time of only 10 min per sample, this assay had an overall recovery of >97% with a detection limit of 1 ng/ml. The inter- and intra-run relative standard deviations at 0.05, 0.2 and 1.0 microg/ml were all <9.2%, while the analytical recovery at the same concentrations were within 7.7% of the amount added.

Acetates↗
PubMed2000

Sensitive assay for the determination of cefazolin or ceftriaxone in plasma utilizing LC.

A rapid, specific and very sensitive liquid chromatographic assay using standard ultraviolet detection has been developed to measure cefazolin (CFZ) or ceftriaxone (CFX) in small samples (200 microl) of plasma using either drug as the internal standard for measurement of the other. A rapid extraction was performed using C18 bonded Sep Pak cartridges with high extraction efficiency for both drugs. The chromatographic system employed the use of a Nova-Pak C18 4-microm cartridge with a radial compression system preceded by a Guard-Pak with a C18 insert. The mobile phase consisted of an aqueous solution containing 10 mM of dibasic potassium phosphate and 10 mM cetyltrimethylammonium bromide (pH 6.5) with acetonitrile (73:27 v/v). The drug and internal standard (CFZ/CFX) were detected using a UV detector set at a wavelength of 274 nm. Assay results were linearly related to the concentration (r > 0.997) for the wide range which was examined (0.005-120 microg/ml) for either drug. We report the precision, accuracy, recovery, linearity, sensitivity and specificity of this assay. The intra-run and inter-run CV was less than 9.02%. This method is currently being used for clinical therapeutic monitoring and pharmacokinetic studies of CFZ and CFX in patients undergoing cesarean section.

Cefazolin↗
PubMed2000

Culturally sensitive care during childbirth.

The objective of this study was to identify culturally grounded meanings of the concepts of comfort, presence, and involvement in the context of the childbirth experience. This was an exploratory study using a descriptive, qualitative design. The sample was made up of Black and White American women more than 18 years of age, who had given birth within the past 72 hours, and spoke English as their primary language. The analytical protocol followed was content analysis-i.e., the systematic reduction and simplification of data. To increase the validity and reliability/reproducibility of the analytic strategy, the researchers independently reviewed the process of data reduction to ensure conceptual clarity and consistency in the classification and elucidation of data. The conclusion reached was that differences exist between Black and White American women as regards descriptions and expectations about the concept of comfort and involvement during the labor and birth experience. These findings have implications for individual nursing practice behaviors as well as for the development of unit-based policies and prenatal education.

Adult↗
PubMed2000

Optimization of oral etoposide dosage in elderly patients with non-Hodgkin's lymphoma using the fraction of dose absorbed measured for each patient.

This study was undertaken to investigate the pharmacokinetics of etoposide for optimizing its oral dosage in elderly patients with non-Hodgkin's lymphoma (NHL) using the fraction of dose absorbed calculated from the data generated from first oral and intravenous doses in the same patient. Twenty-three NHL patients (ages 61-95 years) entered this study. Each received 50 mg/m2 of etoposide by 1-hour i.v. infusion, which was repeated every 24 hours for 5 days. The second cycle commenced on day 21, with etoposide being administered by mouth at a dose as close to 50 mg/m2 as possible. Serial blood samples were collected and analyzed for etoposide by HPLC. The fraction of dose absorbed (F) was calculated as F = (AUCor/AUCi.v.) (Di.v./Dor), and etoposide was then given orally for the following 20 days at a daily dose equivalent to Dor/F. After 1 week free of etoposide administration, a second cycle of oral etoposide at the adjusted dose was given for 21 days. The mean +/- SD values for t1/2 beta, tmax, Cmax, CLTor, and MRT observed following the first oral dose were 8.98 +/- 4.84 h, 1.39 +/- 0.96 h, 0.083 +/- 0.046 mg.L-1/mg.m-2, 1.89 +/- 1.2 L.h-1/m2, and 10.37 +/- 2.76 h, respectively, and those observed following the first intravenous dose were 8.05 +/- 5.11 h, 1.57 +/- 0.17 h, 0.142 +/- 0.043 mg.L-1/mg.m-2, 1.25 +/- 0.44 L.h-1/m2, and 7.69 +/- 1.53 h, respectively. The mean +/- SD of F was 0.80 +/- 0.34. The data obtained indicate that optimization of etoposide oral dosage using F yielded good clinical results while keeping the morbidity at a level that is similar to that of the i.v. administration.

Administration, Oral↗
PubMed1999

Plasma and urinary selenium in Saudi Arabian patients with dilated cardiomyopathy.

We measured selenium (Se) levels in the urine and blood plasma samples of 72 Saudi Arabian patients with dilated cardiomyopathy (DCM) and 70 control subjects of the same origin. To correct for differences in the hydration state of the subjects, the selenium concentration for each urine sample was normalized by dividing it by the concentration of creatinine (CREAT) in the same sample. The median (and range) of the values found for the concentration of Se in plasma, urine, and normalized concentration in urine for the control subjects was 1.306 (0.66-2.50) microM, 0.478 (0.05-2.00) microM, and 56.7 (10.6-426.5) microM Se/M CREAT, respectively, whereas, for the patients, it was 1.246 (0.53-2.45) microM, 0.39 (0.05-1.90) microM, and 75.1 (4.9-656.2) microM Se/M CREAT, respectively. Additionally, the patients were separated into three subgroups according to the severity of their disease state as judged by NYHA procedure, and were then compared to the control group. Only group 4 (the most severe state of the disease) had a significantly lower concentration of urinary Se than the control group. However, the difference became nonsignificant when normalized for CREAT levels. There was no significant difference in the plasma Se levels between the controls and any of the patient groups. As the plasma Se in the control group and in the DCM patients both fell on the low end of the "normal" range, with the patients being marginally lower than the controls, there is no firm evidence from this study to suggest that Se is related to the high incidence rate of DCM found in Saudi Arabia.

Adolescent↗
PubMed1999

Neonatal skin care: the scientific basis for practice.

OBJECTIVE: To review the literature addressing the care of neonatal skin. DATA SOURCES: Computerized searches in MEDLINE and CINAHL, as well as references cited in articles reviewed. Key concepts in the searches included neonatal skin differences; neonatal skin and care practices for skin integrity; neonatal skin and toxicity; permeability; and contact irritant sensitization. STUDY SELECTION: Articles and comprehensive works relevant to key concepts and published after 1963, with an emphasis on new findings from 1993 to 1999. One hundred two citations were identified as useful to this review. DATA EXTRACTION: Data were extracted and organized under the following headings: anatomy and physiology of the skin; physiologic and anatomic differences in neonatal skin; nutritional deficiencies; skin care practices; and care of skin breakdown. DATA SYNTHESIS: Newborns' skin is at risk for disruption of normal barrier function because of trauma. In light of available evidence about differences in neonatal skin development, clinical practice guidelines are suggested for baths, lubrication, antimicrobial skin disinfection, and adhesive removal. In addition, basic care practices are suggested for maintaining skin integrity, reducing exposure to potentially toxic substances, and promoting skin health beyond the neonatal period. Preventive care recommendations are made for reducing trauma, protecting the skin's immature barrier function, and promoting skin integrity. CONCLUSIONS: This review generated evidence with which to create a new and comprehensive practice guideline for clinicians. Evaluation of the guideline is under way at 58 U.S. sites.

Baths↗
PubMed1999

Suspended mothering: women's experiences mothering an infant with a genetic anomaly identified at birth.

PURPOSE: To develop an understanding of the experiences of women who give birth to an infant with a genetic anomaly not identified during the prenatal period. DESIGN: Exploratory design using selected qualitative methods. SAMPLE: Seven mothers of liveborn infants with a genetic anomaly characterized by physical attributes evident at birth. MAIN OUTCOME VARIABLE: Mother's expressions of suspended mothering. RESULTS: Two themes emerged that characterize the experience of suspended mothering: diminished maternal role and false protection. PRACTICE RECOMMENDATIONS: Facilitating maternal involvement in decision making requires giving women unbiased information in a supportive manner.

Adult↗
PubMed1998

Simultaneous high-performance liquid chromatography analysis of azithromycin and two of its metabolites in human tears and plasma.

This article describes a high-performance liquid chromatographic (HPLC) method for the measurement of azithromycin (AZI) and two of its metabolites, 9a-N-desmethylazithromycin (ADES) and N-desmethylazithromycin (NDES), in human tears and plasma. The drug, metabolites, and internal standard (n-propylazithromycin [IS]) were detected electrochemically after injection of the extracted sample into the HPLC system. The peak height ratio (AZI, ADES, or NDES to IS) varied linearly, with concentrations in the ranges of 0.1 mg/L to 2.0 mg/L (tears) and 0.01 mg/L to 2.0 mg/L (plasma) of AZI, ADES, and NDES; the correlation coefficient (r) was more than 0.994 mg/L for all of the compounds (n=6). The analysis of tear samples collected at different intervals within 12 hours to 144 hours after a dose of 20 mg/kg of AZI from a trachoma patient yielded concentrations ranging from 1.52 mg/L to 0.34 mg/L for AZI, 0.79 mg/L to 0.27 mg/L for ADES, and 1.99 mg/L to less than 0.20 mg/L for NDES. The concentration of AZI in plasma ranged from 0.15 mg/L to 0.01 mg/L, whereas ADES and NDES were undetectable.

Anti-Bacterial Agents↗
PubMed1998

Ethical implications of genetic testing.

Advances in biotechnology have created previously unforeseen possibilities to determine the genetic make-up of individuals and to predict the health of future societies. This article identifies some of the issues and dilemmas confronted by health professionals and consumers as these technologic advances move from the laboratory to the clinical setting.

Ethics, Clinical↗
PubMed1998

Values of mothers of low birth weight infants in the NICU.

The research reported in this article explored the concept of values as operationalized by the mothers of infants requiring neonatal intensive care. In the study, which used an exploratory design, data were collected from mothers (n = 14) of infants admitted to the neonatal unit with a primary diagnosis of low birth weight. Participants were interviewed using a semistructured interview guide. Transcripts were analyzed using the constant comparative method. Four themes illustrating the value perceptions of mothers related to their low birth weight infants and the neonatal intensive care experience were identified. The emergent themes describe the mothers' desire to parent their children and the mothers' values related to the integration of technology and human interaction in the environment of the neonatal intensive care unit.

Adolescent↗
PubMed1997

Pharmacokinetics of mesna and dimesna after simultaneous intravenous bolus and infusion administration in patients undergoing bone marrow transplantation.

This study was undertaken to examine the pharmacokinetics of mesna and its dimer form, dimesna, in the plasma and urine of patients undergoing bone marrow transplantation who received 130 mg/kg of mesna divided intravenously into a 30-mg/kg bolus dose followed immediately by 100 mg/kg infused over 12 hours for uroprotection. The relationship between and urinary excretion of mesna and dimesna also was examined by comparing the data obtained in patients who developed hemorrhagic cystitis versus those who did not. Blood and urine samples were collected at different time intervals after administration, and the plasma or urine was analyzed by liquid chromatography with electrochemical detection. Dimesna was analyzed in these samples after reduction back to mesna with sodium borohydride. The concentration-time data of mesna exhibited the characteristics of the two-compartment model well, and the mean +/-SD values of the distributive phase half-life (t1/2 alpha), postdistributive phase half-life (t1/2 beta), volume of distribution of the central compartment (Vdc), volume of distribution at steady state (Vdss), volume of distribution during the postdistributive phase (Vd beta), total clearance (Cl), and mean residence time (MRT) observed were 0.12 +/- 0.15 hours, 2.12 +/- 1.61 hours, 0.324 +/- 0.336 L/kg, 1.09 +/- 1.18 L/kg, 2.09 +/- 3.0 L/kg, 0.755 +/- 0.507 L/hr.kg, and 6.77 +/- 0.72 hours, respectively. The mean +/-SD values of t1/2 and MRT of dimesna were 1.29 +/- 0.6 hours and 6.68 +/- 1.05 hours, respectively, and the ratio of the area under the concentration-time curve (AUC) of mesna to that of dimesna was 1.21 +/- 0.57. The fractions of dose excreted in urine in the form of mesna and dimesna in 20 hours (fu) were 0.361 +/- 0.15 and 0.482 +/- 0.25, and the renal clearance (ClR) values were 0.244 +/- 0.201 L/hr.kg and 0.157 +/- 0.156 L/hr.kg, respectively. The urinary excretion of mesna in these patients was higher than that required for uroprotection for the whole duration of infusion, and there was no significant difference in the pharmacokinetics of mesna between patients who developed hemorrhagic cystitis and those who did not. This was not the case with dimesna, in which patients with hemorrhagic cystitis excreted in urine less than 50% of the amount of dimesna excreted by those without hemorrhagic cystitis.

Adolescent↗
PubMed1996

Fetal surveillance: issues and implications.

In the past, the fetus was considered healthy until evidence was presented to the contrary. With the acceptance of fetal surveillance as part of the pregnancy experience, diagnostic testing and data are thought to be necessary to prove the healthiness of the fetus. The availability of fetal surveillance techniques has transformed the pregnancy experience from a developmental process and a miracle of nature to a risk-dominated and technology-guided event. The implications of this trend significantly affect the care of pregnant women and the role of nurses as providers of comprehensive, individualized nursing care.

Female↗
PubMed1996

Choices of neonatal nurses in ambiguous clinical situations.

This article reports a study of the nurse's choice of level of management and factors influencing that choice in three ambiguous clinical situations related to neonatal nursing. A nationwide mail survey, using a Likert scale, was conducted on a random sample of the membership of the National Association of Neonatal Nurses. The findings of this research suggest that nurses have clearly defined choices related to the degree of intensity of management of infants, based on consideration of the information available to the nurse in the neonatal setting. These findings have implications for nursing practice and education and consequences for the quality of nursing care provided to infants and their families.

Adult↗
PubMed1996

Parents' values: a missing link in the neonatal intensive care equation.

Neonatal intensive care has become a widely accepted component of our health care system. Its acceptance and growth are related to increased technology and specialization. However, little consideration has been given to the process of making decisions about the use of neonatal intensive care from the perspective of the patient's family. This article reviews the existing literature related to parents' opinions and perceptions of care in the NICU and proposes a framework for the exploration of the value systems of parents of infants requiring neonatal intensive care.

Attitude to Health↗
PubMed1995

Steady-state kinetics of fluoxetine and amitriptyline in patients treated with a combination of these drugs as compared with those treated with amitriptyline alone.

The steady-state kinetics of amitriptyline (AMI), fluoxetine (FLU), and their active metabolites nortriptyline (NTRIP) and norfluoxetine (NFLU) were studied in 15 patients treated once daily for long durations with 50 mg of AMI and 20 mg of FLU. These compounds were analyzed simultaneously in plasma by liquid chromatography. The means and (SEM) of the steady-state concentrations (Css) of AMI, NTRIP, FLU, and NFLU were 80.6 (14.2), 52.6 (10.3), 85.3 (16.1), and 90 (13.6) ng/mL, respectively, and the apparent oral clearances (CLor) of AMI and FLU were 42.4 (8.6) and 14.9 (2.5) L/hr, respectively. The metabolite/drug steady-state concentration ratio (Css(m)/Css) for NTRIP/AMI was 0.75 (0.14) and for NFLU/FLU was 1.27 (0.17). There was a significant correlation (P < 0.05) between Css of FLU and that of AMI or NTRIP. The Css and Css(m)/Css values obtained for AMI were higher (P < 0.056 and P < 0.0034, respectively) than those we observed in 10 patients treated solely with the same dose of AMI. The twofold increase in Css of AMI and ninefold increase in Css of NTRIP seem to be the result of inhibition of the metabolism of these compounds by FLU, particularly the ring hydroxylation. Norfluoxetine may have a small inhibitory influence on the metabolism of NTRIP but lacks this effect on the metabolism of AMI.

Adolescent↗
PubMed1995

Relationship between antipyrine metabolism and acetylation phenotype in health and chronic liver diseases.

The authors examined the activity of N-acetyltransferase and that of microsomal P-450 isoenzymes in health and hepatic disease state by determining the acetylation phenotype and the total (CLAP) and metabolic clearances of antipyrine to form norantipyrine or N-demethylantipyrine (MCLnora), 3-hydroxymethylantipyrine (MCLhma), and 4-hydroxyantipyrine (MCLha) in 21 healthy subjects and in 33 patients with chronic liver diseases (CLD) and investigated the relationship between the activities of these two enzyme systems. The acetylation phenotype was determined according to the urinary caffeine metabolites test. The mean and (SEM) of CLAP, MCLhma, MCLha, and MCLnora in healthy subjects were 2.42 (0.264), 0.193 (0.031), 0.322 (0.045), and 0.288 (0.04) L/h, and those observed in patients with CLD were 0.98 (0.1), 0.076 (0.015), 0.131 (0.026), 0.103 (0.022) L/h, respectively. The prevalence of fast acetylation among the healthy subjects and patients with CLD was 38% and 39%, respectively. Although all metabolic clearances appear to be reduced in healthy slow acetylators, the reduction was only significant in MCLnora, indicating a direct association between the activity of N-acetyltransferase and that of P-450 IIIA3 responsible for the N-demethylation of antipyrine. Conversely, slow acetylators with CLD exhibited significantly higher CLAP and near-significantly larger metabolic clearances including MCLnora, which suggests that P-450 activity in fast acetylators is more sensitive to chronic liver diseases than in slow acetylators.

Acetylation↗
PubMed1995

Antipyrine clearance and metabolite excretion in patients with chronic hepatitis C.

BACKGROUND/AIMS: Our aim was to study whether chronic hepatitis C affects the three metabolic pathways of the model drug antipyrine differently. METHODS: We measured antipyrine clearance from saliva as well as urinary excretion of its main metabolites 4-hydroxy-antipyrine, 3-hydroxy-methyl-antipyrine, and nor-antipyrine in 24 patients with chronic hepatitis C and in 21 healthy control subjects. Due to incomplete urine collection, 12 liver patients and three controls were excluded. RESULTS: Antipyrine clearance (mean +/- SD) was significantly lower in patients with chronic hepatitis C, 1.2 +/- 0.7 l.h-1 (n = 12), than in controls (n = 18), 2.2 +/- 1.0 l.h-1 (p = 0.006). The urinary excretion of each of the metabolites was depressed to an equal extent in liver patients. The severity of the liver disease, as assessed by Child Pugh score, serum albumin and bilirubin, correlated significantly with antipyrine clearance and urinary excretion of the metabolite 3-hydroxy-methyl-antipyrine. The hepatitis activity index (Knodell) correlated with 3-hydroxy-methyl-antipyrine and 4-hydroxy-antipyrine, only. CONCLUSIONS: Moderate-severe chronic hepatitis C does not seem to depress the three main metabolic pathways of antipyrine differently.

Adult↗