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Biomedical subjects

P Finn

Publications and source records attributed to P Finn.

At least 19 recordsLinked to original sources

The value of deletion analysis for carrier detection in Duchenne muscular dystrophy (DMD).

We performed genetic analysis for carrier detection for several at-risk females in a four-generation Duchenne muscular dystrophy (DMD) pedigree using deletion analysis. We demonstrated that dosage analysis is a suitable alternative method to determine the carrier status of female relatives of DMD patients shown to have a deletion within the DMD gene. Subsequently, we diagnosed an affected male fetus for an at-risk female shown to be a DMD carrier by deletion analysis. The usefulness of deletion and linkage analysis are compared. In this family, linkage analysis was complicated by the unavailability of key family members, two recombination events and by previously undisclosed nonpaternity. We found that dosage analysis was more efficient than linkage for carrier evaluation in this family.

Adult

A frame-shift mutation in the cystic fibrosis gene.

Cystic fibrosis (CF) is a common recessive lethal genetic disorder, affecting 1 in 1,600 Caucasians. The disease causes defective regulation of chloride-ion transport in exocrine cells. Although in all CF families the disease is linked to a locus on chromosome 7q31, there is clinical heterogeneity in the severity of the disease and the age at which it is diagnosed. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. A three-nucleotide deletion (delta F508) causing the loss of a phenylalanine residue in the tenth exon of the CFTR gene has been found on 70% of CF chromosomes. We have now characterized a CF family in which neither parent of the affected individual carries the common mutation, and identified a two-nucleotide insertion in the CF allele of the mother. The mutation introduces a termination codon in exon 13 of the CFTR gene at residue 821, and is predicted to result in the production of a severely truncated nonfunctional protein.

Alleles

Joubert syndrome: a clinico-radiological study.

A characteristic malformation of the cerebellum, including dysgenesis of the vermis and enlargement of the fourth ventricle was observed on computed tomography (CT) in 16 children on review of our consecutive material. Seven of these children underwent magnetic resonance imaging (MRI) which showed hypoplasia of the brainstem in addition to cerebellar vermian dysgenesis. One child had, in addition, dysgenesis of the corpus callosum. All these children were developmentally delayed, and many had neonatal breathing abnormalities, congenital retinal dystrophy and supranuclear ocular motor abnormalities. Joubert's syndrome should be suspected in children in whom dysgenesis of the cerebellar vermis and hypoplasia of the brainstem is shown on CT or MRI.

Brain Stem

Inherited predisposition to alcoholism: characteristics of sons of male alcoholics.

Sons of male alcoholics (SOMAs) are at markedly heightened genetic risk for the development of alcohol abuse. Study of SOMAs could therefore conceivably increase the efficiency of research aimed at uncovering those heritable factors that predispose to alcoholism. SOMAs manifest observable behavioral, cognitive, and psychophysiological abnormalities while sober and react idiosyncratically to alcohol intoxication. They are most commonly described as conduct disordered and hyperactive, appear heir to a variety of deficits in verbal and abstract cognition, and perform more poorly in the academic environment. SOMAs are characterized by abnormal patterns of cued psychophysiological response, and appear more sensitive to the putatively reinforcing aspects of alcohol intoxication. Various methodological weaknesses permeate the relevant literature. Some straightforward improvements are suggested.

Adolescent

Biochemical aspects of tryptophan depletion in primates.

We studied the degree of plasma tryptophan depletion produced by giving normal human males different amounts of a tryptophan-free (T-) amino acid mixture. From the results of this and other studies we concluded that the maximum degree of tryptophan depletion can be produced by a 31.5 g mixture of seven essential amino acids. Administration of a T- amino acid mixture to vervet monkeys lowered tryptophan and 5-hydroxyindoleacetic acid in the cerebrospinal fluid. Levels of tyrosine and the catecholamine metabolites were unchanged. These data support the idea that the effects of T- mixture on mental function in humans which have been reported previously are due to a decrease in 5-hydroxytryptamine.

Adolescent

Autonomic hyperreactivity and risk for alcoholism.

1. Studies which illustrate autonomic hyperreactivity in sons of alcoholics are reviewed and discussed. This response is elicited by a wide range of stimuli which vary from the stressful to the incidental. It also occurs independently of coping strategy. This hyperreactivity, which is particularly characteristic of multigenerational sons of alcoholics is significantly dampened by alcohol. This pattern of results supports a negative reinforcement model of alcohol abuse in these individuals.

Alcoholism

The selection of "fluent" samples in research on stuttering: conceptual and methodological considerations.

The characteristics of stutterers' fluency has been the object of much research in recent years, but it is not always clear what the term "fluency" refers to in this research. This paper reviews the concept of fluency and considers the ways in which it has been employed in research on stuttering. The methods that have been used to identify fluent intervals in stutterers' speech are reviewed along with their reliability and validity. It is concluded that there is an urgent need to clarify the reference for fluency in such studies, and to develop procedures for measuring and quantifying fluency. Additional avenues for research are also discussed.

Humans

Stutterers' self-ratings of speech naturalness: assessing effects and reliability.

Using single-subject experiments with 3 adult stutterers, this study evaluated the effects of instructions to stutterers to rate and modify how natural their speech sounds on experimenters' ratings of speech naturalness, stuttering frequency, and speaking rate. The study also included an investigation of the reliability of stutterers' and listeners' naturalness ratings. The stutterers were partway through a therapy program using prolonged speech or rate control. Results showed the stutterers could modify their speech so that their naturalness ratings increased or decreased. These changes were independent of stuttering or speaking rate. Experimenter ratings of speech naturalness were unchanged in conditions where stutterers judged their speech to sound more natural, but paralleled the stutterers' ratings when they judged their speech to sound more unnatural. An attempt to see if stutterers differed in their ratings of how natural their speech sounded or felt showed differences for one stutterer. Reratings of randomized session recordings by experimenters and independent judges showed that their ratings were highly reliable. When the same randomized session recordings were rerated by the stutterers (1 and 3 months after the experiment), their judgments of changes in their speech naturalness, which were not found in the experimenters' ratings, remained consistent and reliable.

Behavior Therapy

Self-monitored pain intensity: psychometric properties and clinical utility.

A procedure for the evaluation of fluctuations in perceived pain intensity among chronic pain patients is described, and its psychometric properties and clinical and heuristic utility are examined. A heterogeneous sample of 97 chronic pain patients recorded 2 weeks of hourly self-monitored pain intensity (SMPI), completed a structured interview and several questionnaires, and established behavioral goals prior to participation in a pain rehabilitation program. Three variables were derived from the SMPI data: mean SMPI, variability, and number of missing observations. A series of analyses supported both the test-retest reliability and the concurrent validity of SMPI. Significant correlations with measures of depression, anxiety, marital satisfaction, perceived life interference, and activity levels were interpreted as support for the conceptual validity of SMPI within a cognitive-behavioral perspective. The utility of SMPI in predicting rehabilitation outcomes was also demonstrated.

Activities of Daily Living

P300 latency after ethanol ingestion in sons of alcoholics and in controls.

The magnitude and persistence of ethanol-induced increases in the latency of the P3 event-related potential from auditory stimuli were evaluated in 21 sons of alcoholic fathers (FHP) and 21 control sons of nonalcoholics (FHN) matched on demography and drinking history. The men were assessed at baseline, 70 min after imbibing a beverage, and 240 min after drinking, with observations carried out for each individual in 3 dosage conditions (placebo, 0.75 ml/kg of ethanol, and 1.1 ml/kg of ethanol). There were no family group differences for baseline (prechallenge) P3 latencies, nor any significant group differences after placebo or low-dose ethanol challenges. However, in the high alcohol dose challenge condition, P3 latencies for FHP subjects returned toward baseline measures more quickly than for FHN men. These results are consistent with previous reports of behavioral and biochemical measures in which FHP subjects demonstrated less intense reactions or returned toward baseline conditions more rapidly after ethanol ingestion relative to the FHN controls.

Adult

Aging alterations in the modulation of central dopaminergic cilioinhibition by etorphine in the marine mussel, Mytilus edulis: decrease in the inhibition of presynaptic dopamine release.

1. This report further demonstrates that etorphine influences presynaptic dopamine release, which in turn centrally modulates peripheral cilioinhibition. 2. In older animals cilioinhibition has become enhanced due to a lack of responsiveness to endogenous opioids which results in greater dopamine release, causing a higher level of cilioinhibition as demonstrated by challenging the visceral ganglia with etorphine or destroying the dopaminergic component with 6-hydroxydopamine. 3. Only the central cilioinhibitory, not the peripheral inhibitory response, mechanism appears to be altered in older animals. Thus, the alteration appears in the central integrative mechanisms involved with regulating ciliary activity. 4. The KCl-stimulated release of dopamine is unaltered in both young and old organisms, whereas the opiate inhibition of the KCl-stimulated release of dopamine is reduced in older organisms. Thus, the aging-associated alteration is associated with a specific process. 5. The reduction of opioid influence and the resulting enhanced cilioinhibitory activity may make the organisms more susceptible to environmental stress.

Aging

Perception of the risk of an accident by young and older drivers.

Young drivers are significantly overrepresented among all drivers involved in traffic accidents and fatalities. Excessive risk taking by young drivers appears to be largely responsible for this disproportionate involvement. This excessive risk taking could be due to being more willing to take risks than older drivers are, failing to perceive hazardous situations as being as dangerous as older drivers do or both causes. This paper reports the results of a study which attempted to determine whether misperception of risk could be an explanation for the high rates of traffic accidents among youth by testing whether young drivers perceive driving to be less hazardous than do older drivers. Three different methods of estimating the risk of accident involvement were used to compare risk estimates of young and older drivers. The methods included general questions about accident involvement, rating the riskiness of ten specific driving situations illustrated in still photographs, and rating the riskiness of fifteen videotaped driving situations. Young drivers perceived their own chances of an accident to be significantly lower than those of both their peers and older male drivers, while older male drivers saw their chances of accident involvement as comparable to those of their male peers and less than those of young male drivers. These findings lend support to the thesis that young male drivers are overrepresented in traffic accidents at least in part because they fail to perceive specific driving situations as being as risky as older drivers perceive them.

Accidents, Traffic

Influence of safety belt usage on perception of the risk of an accident.

Does the use of a safety belt increase or decrease the perception of the risk of an accident? Young and older male drivers were asked to drive an urban route and rate their perceptions of the risk of an accident. On the first driving trip all subjects were unbelted, while on the second driving trip half of the subjects wore a safety belt while half did not. Results indicated that young male drivers decrease their perception of the risk of an accident as they become familiar with a driving route if they are NOT wearing a safety belt. Young male drivers asked to wear a safety belt sustained their perception of the risk of an accident as they became familiar with the test route. Older drivers' perception of the risk of an accident was not affected by familiarity or safety belt usage.

Accidents, Traffic

Survival after an experimental myocardial infarction: beneficial effects of long-term therapy with captopril.

Although vasodilator therapy has been shown to improve functional capacity in patients with congestive heart failure, there is no evidence that such therapy can prolong survival. Coronary artery ligation in the rat was used to produce a wide range of myocardial infarct sizes and a resultant spectrum of left ventricular dysfunction. To determine the relationship between size of myocardial infarction and long-term survival and to test the hypothesis that long-term therapy with captopril could improve survival after myocardial infarction, 302 rats were randomly assigned to either placebo or captopril therapy 14 days after coronary artery ligation. The animals were kept in a laminar flow unit and followed daily for a 1 year period or until spontaneous death. Size of myocardial infarction was determined by planimetry of serial histologic sections of the left ventricle. One year survival in placebo-treated rats decreased markedly in direct relation to increasing size of infarction (from 71% in noninfarcted rats to only 8% in rats with large infarcts). Long-term captopril therapy prolonged the survival of rats with infarcts (p less than .02). The most marked improvement in survival was noted in the animals with infarcts of moderate size, in which 1 year survival was 21% in the placebo-treated rats and 48% in the captopril-treated rats. Thus, in this experimental preparation of myocardial infarction and left ventricular dysfunction, survival was inversely related to size of infarction. Long-term therapy with captopril, which we had previously shown to improve left ventricular function and lessen dilatation in the chronic phase of infarction, also had a pronounced effect on prolonging survival in this preparation of chronic infarction.

Animals

Decriminalization of public drunkenness: response of the health care system.

Thirty-four U.S. jurisdictions have fully implemented the major provisions of the Uniform Alcoholism and Intoxication Treatment Act, calling for the decriminalization of public drunkenness. Available evidence strongly suggests that the Uniform Act has only imperfectly achieved two of its principal goals: the redirection of responsibility for the public inebriate from the criminal justice system to the health care system, and the rehabilitation of public inebriates through participation in a continuum of health care services. Explanations for these failures may lie in both the concept of detoxication and in the effectiveness with which the concept has been implemented. However, additional research is needed to provide adequate data for fully assessing the impact of the act and explaining its apparent failure.

Aftercare

Teenage drunkenness: warning signal, transient boisterousness, or symptom of social change?

It is important for anyone working with youngsters, including counselors, physicians, psychiatrists, social workers, school administrators, and parents to familiarize themselves with the prevalence and characteristics of youthful drunkenness. Several attitudes toward this widespread adolescent behaviour are now current--and often in conflict--in our society, including viewing teenage intoxication as a symptom of problem drinking, a warning signal of future alcoholism, a reflection of cultural norms and social changes, and an expression of youthful boisterousness. Tentative conclusions are reached regarding the validity and usefulness of each of these different perspectives of youthful drinking behavior.

Adolescent