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Biomedical subjects

D Kohen

Publications and source records attributed to D Kohen.

At least 19 recordsLinked to original sources
PubMed2001

Genetic association studies of schizophrenia using the 8p21-22 genes: prepronociceptin (PNOC), neuronal nicotinic cholinergic receptor alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1).

Schizophrenia is a common, genetically heterogeneous disorder with a lifetime prevalence of approximately 1% in the general population. Linkage studies of affected families have now strongly implicated a susceptibility locus on chromosome 8p21-22. Tests of allelic association with markers on 8p21-22 should be able to localise any quantitative trait nucleotides (QTN's) or susceptibility mutations to within a few hundred kilobases. Three brain expressed candidate susceptibility genes, prepronociceptin (PNOC), neuronal cholinergic receptor, nicotinic, alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1) have been mapped to chromosome 8p21-22. A case-control, allelic association study was performed using a novel highly polymorphic dinucleotide repeat, D8S2611 near the PNOC gene, two previously characterised dinucleotide repeats, D8S131 and D8S131P at the CHRNA2 locus and an RFLP at the 3'UTR of the arylamine N-acetyltransferase 1 (NAT1) gene. No differences were found in allele frequencies between the patient and control groups. DNA variations or mutations at or near the three genes under study are unlikely to increase susceptibility to schizophrenia in our population sample.

3' Untranslated Regions↗
PubMed2000

Diversity in liquid supercooling and glass formation phenomena illustrated by a simple model

The opportunity to map condensed-phase inherent structures (potential energy minima) approximately onto the vertices of a high-dimensional hypercube provides simple conceptual and numerical modeling for first-order melting-freezing transitions, as well as for liquid supercooling and glass formation phenomena. That approach is illustrated here by examination of three interaction examples that were selected to demonstrate the diversity of thermodynamic behavior possible within this hypercube modeling technique. Two of the cases behave, respectively, as "strong" and "fragile" glass formers, at least as judged by their heat capacities. The third presents a "degenerate glass," wherein full equilibration of the supercooling liquid (i.e., no kinetic arrest) leads to (a) residual entropy in the limit of absolute zero temperature, and (b) a linear temperature dependence of heat capacity in the same limit. None of the three cases displays a positive-temperature ideal (intrinsic) glass transition.

Journal Article↗
PubMed1998

The role of anxiety and depression in quality of life and symptom reporting in people with diabetes mellitus.

Although quality of life evaluations are widely used throughout medicine, relatively little is known about the psychological processes involved in making these judgements. What is known is that quality of life judgements are not straightforwardly associated with objective measures of health status or clinician ratings. In particular, patient affect appears to be associated with quality of life ratings but whether this relationship is secondary to physical health or not is controversial. The aim of this study was to determine the role of anxiety and depression in the reporting of quality of life in a group of patients with diabetes mellitus. One hundred consecutive patients with diabetes (insulin-dependent diabetes mellitus n = 36 and non-insulin-dependent diabetes n = 64) were assessed using a self-report measure of quality of life, a symptom checklist and a questionnaire measure of anxiety and depression. In addition, they were independently rated for their level of physical impairment. The results showed that depression and, to a lesser extent, anxiety were significantly related to self-reported quality of life even when the differences in physical health and age were controlled for statistically. This study shows that, independent of the level of physical illness, affect, particularly depressive affect, is an important factor in the determination of quality of life.

Activities of Daily Living↗
PubMed1998

A five-year follow-up study of older long-stay clients with intellectual disability using the Disability Assessment Schedule.

The emphasis on community care means closure of the long-stay institutions for people with intellectual disability. Studies have indicated that older people with intellectual disability in particular may not be adequately cared for because of poor monitoring of their changing needs and inadequate provision of services. The use of rating instruments to monitor changes, and to predict outcome or needs in this population may help to improve care by assisting with planning and projection of service requirements. In 1991, all residents of a long-stay hospital for people with intellectual disability were assessed using the Disability Assessment Schedule (DAS). Five years later, the 1991 scores of the older residents (aged > 50 years) were reviewed and compared under three outcome groups: in-patients, discharged and deceased. Furthermore, all older people resident in the hospital in 1996 were reassessed using the DAS. Out of the 144 older clients resident in 1991, five years later, 78 were still in-patients, 38 had been discharged into the community and 28 were deceased. In 1991, the decreased group had the greatest problems with continence and symbolic behaviour, while the discharged group had the greatest problems with self-help, vision, hearing, communication, social interaction, echolalia and repetitive speech. In comparison with 1991, the 1996 DAS scores of older residents showed that there were increasing problems with vision, hearing, communication, behaviour and symbolic activities. The present study suggested that the DAS is a useful instrument for monitoring change and predicting outcome in older people with intellectual disability.

Activities of Daily Living↗
PubMed1996

Movement disorder in Down's syndrome: a possible marker of the severity of mental handicap.

This study examined the nature and prevalence of abnormal movements in adults with Down's syndrome and also the clinical correlates of orofacial dyskinesia and the relationship between dyskinesia and the level of functional and intellectual disability. Movement disorder, language age, and disability were assessed in an epidemiologically based sample of 145 individuals with Down's syndrome. Abnormal involuntary movements were common, with > 90% exhibiting dyskinesia, predominantly orofacial. Stereotypes were present in one-third of the sample. There was an association between the severity of dyskinesia and both current language age and functioning in terms of self-care and practical and academic skills, which suggested that dyskinesia may be a marker of the severity of mental handicap. The presence of dyskinesia was unrelated to neuroleptic exposure. Dyskinesia and stereotypies are very common in individuals with Down's syndrome and may represent an inherent manifestation of the disorder. The relationship between mental age and dyskinesia in Down's syndrome warrants further research.

Activities of Daily Living↗
PubMed1994

Eltoprazine in aggressive mentally handicapped patients: a double-blind, placebo- and baseline-controlled multi-centre study. The Eltoprazine Aggression Research Group.

The efficacy of eltoprazine, a mixed 5-HT1 agonist, in treating aggressive behaviour in mentally handicapped patients was evaluated in a double-blind, placebo- and baseline-controlled study. In the total sample of 160 patients who entered the 8 week double-blind treatment phase, efficacy was not demonstrated. Also in a 28 week double-blind follow-up study, efficacy could not be demonstrated. Post-hoc exploratory analyses suggested eltoprazine was significantly better than placebo in reducing aggression scores of a subgroup of severely aggressive patients. There was no evident relationship between the plasma level of eltoprazine and therapeutic effect or safety and tolerance. The overall safety and tolerance of chronic eltoprazine treatment was good. In the discussion, several issues and pitfalls of aggression research are dealt with.

Adolescent↗
PubMed1993

Handedness in mental handicap: investigation into populations of Down's syndrome, epilepsy and autism.

The handedness in three randomly sampled groups of people with learning disabilities consisting of patients with Down's syndrome, epilepsy, and autism were studied using a validated instrument. All subjects were controlled for neurological and other medical disorders. A statistically significant increase in left-handedness and ambiguous handedness compared with the general population was found in all groups. There was no significant difference in the rate of left-handedness between the three groups.

Adult↗