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Biomedical subjects

D W Clark

Publications and source records attributed to D W Clark.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Adverse drug reaction reporting and retrospective phenotyping for oxidation polymorphism.

A genetically determined impairment in the ability to oxidase sparteine and debrisoquine also affects the oxidation of several other drugs. This impairment in oxidation may result in accumulation of the associated drugs and in an increased susceptibility to adverse reactions from these drugs. Dunedin houses the New Zealand national centre for the collation and study of adverse drug reactions. Included among the reporting schemes is an intensified monitoring system for newly released drugs, in which physicians report all clinical events occurring during treatment with the drugs under surveillance. The centre thus has available extensive records of names and addresses of prescribers and patients who have been reported as experiencing an adverse event while receiving drug therapy. We investigated the association between genetically poor oxidation of sparteine and adverse reactions to drugs selected as possibly sharing the sparteine/debrisoquine oxidation pathway; these included perhexiline, metoprolol, debrisoquine, piroxicam, mianserin and nifedipine. A kit containing instructions, a sparteine capsule and a container for urine collection was sent to physicians who reported adverse reactions or events to one of the above drugs for forwarding to the patient. It appeared possible, after assays of returned urine for sparteine and its metabolites, that adverse reactions to nifedipine were associated with genetically poor oxidation.(ABSTRACT TRUNCATED AT 250 WORDS)

Debrisoquin↗
PubMedDate not supplied

Microcomputer analysis of cortical power spectrum: calibration and correlates of behavioral artifacts.

Cortical power spectrum (CPS) is a quantitative estimate of EEG spectral power density. The CPS provides suitably precise data for quantification and statistical inference compared to the qualitative evaluation of EGG when interpreted by clinicians or researchers. In the past decade, the CPS has been applied to the studies of cognitive functions, memory, psi phenomena, speech laterality, and states of consciousness including coma, sleep, anesthesia, pathophysiology and pain state. However, few systematic evaluations of CPS methodology have been reported, rendering cross-laboratory comparisons difficult and external validity of experimental results uncertain. This report first describes a calibration procedure employing a microcomputer system for measuring the functional relationship between input signals and output cortical powers. Second, we examine controlled behavioral artifact effects on the CPS. The behavioral artifacts observed in the CPS can provide a measurement anchor for less ambiguous interpretation of CPS experiments conducted in clinical or laboratory settings.

Cerebral Cortex↗
PubMedDate not supplied

Control of hindlimb vascular resistance in rats chronically sympathectomized with 6-hydroxydopamine.

1. Vascular resistance was measured after acute surgical denervation in the blood-perfused hind limbs of adult normal rats and rats which had been treated with 6-hydroxydopamine in the first 2 weeks of postnatal life. Vascular resistance was significantly higher in the limbs of 6-hydroxydopamine treated rats. 2. No excess of vasoconstrictor materials was detected when blood from 6-hydroxydopamine treated rats was used to perfuse the hind limbs of untreated rats or other 6-hydroxydopamine treated rats. 3. Hind limb blood vessels of 6-hydroxydopamine treated rats showed increased sensitivity to normal amounts of circulating vasoconstrictors of adrenal origin and to intra-arterial infusions of noradrenaline and angiotensin. 4. Infusion of desipramine into the hindlimb blood vessels of 6-hydroxydopamine treated rats did not increase vasoconstrictor responses to infused noradrenaline. Infusion of desipramine into the limbs of untreated rats increased responses to noradrenaline but these never attained the magnitude and duration of responses seen in limbs of 6-hydroxydopamine treated rats. 5. The increased sensitivity to noradrenaline of hindlimb vessels from 6-hydroxydopamine treated rats could partly be accounted for by an absence of neuronal uptake sites and partly by the development of non-specific post-junctional supersensitivity.

Angiotensin II↗
PubMedDate not supplied

Peripheral cardiovascular effects in rats after central administration of histamine and antihistamines.

1. Vascularly isolated but nervously intact rat right hind limbs were perfused with blood at a constant flow rate and changes in perfusion pressure (proportional to vascular resistance), heart rate and blood pressure were monitored. 2. Histamine administered into the right lateral cerebral ventricle (i.c.v.) through guide cannulae, induced dose-dependent increases in perfusion pressure, heart rate and blood pressure. 3. Prior i.c.v. or i.v. administration of metiamide (an H2-antagonist) did not prevent the cardiovascular responses to i.c.v. histamine but rather prolonged them. Following i.c.v. or i.v. administration of chlorpheniramine (an H1-antagonist), however, changes in vascular resistance, heart rate and blood pressure were not significant. 4. Metiamide administration appeared to have some agonist activity on its own. Thus the role of H2-receptors in cardiovascular responses to centrally administered histamine remains unclear. 5. The work shows that in rats increases in nervous dishcarge to at least the hind limb vascular bed occur following central administration of histamine and conforms that increases occur in heart rate and blood pressure. These responses appear likely to be mediated through stimulation of central H1-receptors.

Animals↗
PubMedDate not supplied

Nurse practitioners develop leadership in community problem-solving.

If nurse practitioners are to become agents of change within the community, a shift in focus from the individual/family/caseload to one that includes population/community will be required. The nurse practitioner will need to develop the skills of community coalition building and grantsmanship. Graduate preparation in primary care nursing can provide an opportunity to develop the necessary knowledge and skills for leadership in community problem-solving by incorporating reality-based learning experiences into the curriculum. A model for guiding graduate study is presented.

Community Participation↗
PubMedDate not supplied

Neuropsychiatric reactions to nonsteroidal anti-inflammatory drugs (NSAIDs). The New Zealand experience.

The New Zealand Medicines Adverse Reactions Committee has been monitoring reports of adverse drug reactions (ADRs) since 1965. We wished to determine the numbers of voluntary reports of different types of ADR to all nonsteroidal anti-inflammatory drugs (NSAIDs) over a long time period and relate these to age. As the elderly are known to suffer from neuropsychiatric adverse effects of many drugs, we investigated neuropsychiatric reactions to NSAIDs to determine whether these were more commonly reported in the elderly. We counted all reported ADRs suspected to be associated with NSAIDs as well as selected types of ADRs reported from 1970 to 1989. These were divided into 5-year periods and 10-year age groupings. In each consecutive 5-year period there was a progressive increase in the numbers of all ADRs reported for all NSAIDs. This was particularly marked above 50 years of age, but the numbers were reduced above 80 years. Reports for females accounted for about two-thirds of all reactions. Not unexpectedly, alimentary and dermatological ADRs accounted for most reactions and were more common in the group above 50 years. Overall, neuropsychiatric reactions were the third most common ADR type reported. Their numbers increased with age and peaked in the 50 to 59 age group, with a sharp decline after 69 years. This age distribution paralleled that for all ADRs to NSAIDs. Although neuropsychiatric reactions to NSAIDs were reported in all age groups, they were not reported more commonly in the elderly. This study suggests that neuropsychiatric reactions to NSAIDs may be more frequent than is commonly believed.

Adolescent↗
PubMedDate not supplied

Retired executives link purchasers and providers in Greater Philadelphia.

A three-year project funded by the John A. Hartford Foundation of New York used retired executives and physicians to overcome Philadelphia area employers' coolness to HMOs. Acting as evaluators, facilitators, educators and advisors, the participants achieved improved understanding and helped raise HMO enrollment from 3.5% to 11.6% of the target population. The President of the Executive Service Corps of the Delaware Valley tells how.

Community-Institutional Relations↗
PubMedDate not supplied

Domestic violence screening, policies, and procedures in Indian health service facilities.

BACKGROUND: Research shows that domestic violence against women in the United States is common, and the prevalence of domestic violence is high among Native American women. Victims of domestic violence can benefit from appropriate office intervention and referral. This study examined the effect of administrative and legal requirements on screening for domestic violence in Indian Health Service (IHS) hospitals and clinics. METHODS: A questionnaire was mailed using the total design method to all IHS hospitals and clinics regarding activities related to domestic violence: screening; policies and procedures; presence of committees; staff training; and state and tribal mandatory reporting requirements. RESULTS: The response rate was 65%. Eighty-eight (62%) of 142 facilities screen for domestic violence. A facility was more likely to screen if it had policies and procedures for domestic violence. Ninety-one (64%) of sites had policies and procedures for domestic violence. Less than one half these sites evaluated the use of these policies and procedures. Hospitals were more likely to have policies and procedures than clinics, as were sites administered by the IHS, rather than those administered by tribal contract. Fifty-eight (40.8%) facilities indicated 18 states have mandatory domestic violence reporting requirements. Thirty-three (23.2%) facilities indicated 31 different tribes mandate reporting of domestic violence. Forty-two (29.6%) facilities reported mandatory staff training in at least one topic related to domestic violence in the past year. CONCLUSIONS: Domestic violence policies and procedures promote screening for this important health care problem.

Domestic Violence↗
PubMedDate not supplied

Disposition of ethanol and its proximate metabolite, acetaldehyde, in the near-term pregnant ewe for short term maternal administration of moderate-dose ethanol.

The effect of short term maternal ethanol administration on the disposition of ethanol in the ovine maternal-fetal unit was determined. Eleven conscious instrumented near-term pregnant ewes (between 125 and 134 days of gestation; term, 147 days) received 1-hr iv infusion of 1 g of ethanol.kg of maternal body weight-1.day-1 for six days (N = 6 ewes) or an equivalent volume of saline for six days (N = 5 ewes). On the seventh day, the ethanol- and saline-pretreated animals were administered 1 g of ethanol.kg of maternal body weight-1. Ethanol and acetaldehyde concentrations were determined by headspace GLC in maternal blood, fetal blood, and amniotic fluid samples obtained at selected times during the 14-hr study. The data demonstrated that short term maternal administration of once-daily moderate dose ethanol did not produce major changes in the disposition of ethanol and its proximate metabolite, acetaldehyde, in the maternal, fetal, and amniotic fluid compartments during near-term ovine pregnancy.

Acetaldehyde↗