Measurements of the anisotropy and temperature dependence of the in-plane energy gap in YBa2Cu3O7- delta using Andreev reflections.
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Journal Article↗
Biomedical subjects
D Cohen
Publications and source records attributed to D Cohen.
Risk factors for dementia associated with multiple cerebral infarcts. A case-control analysis in predominantly African-American hospital-based patients.
OBJECTIVE: To clarify risk factors for dementia associated with cerebral infarction. DESIGN: Case-control study. SETTING: The study was conducted in a hospital setting. PATIENTS: The subjects were consecutive patients with acute stroke with multiple cerebral infarctions who were admitted to the hospital between November 1, 1987, and December 1, 1990. They were predominantly elderly African Americans. Index cases met criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, for multi-infarct dementia, whereas control subjects were patients with multiple infarcts who did not have dementia. There were 61 multi-infarct disease index cases and 86 controls without cognitive impairment. MAIN OUTCOME MEASURES: Demographic and cardiovascular disease risk factor variables. RESULTS: Index cases were older (mean [+/- SD] age, 75.5 +/- 9.7 vs 69.6 +/- 9.1 years), were less well educated (odds ratio, 4.37; confidence interval, 2.12 to 9.04), had lower annual incomes (odds ratio, 8.82; confidence interval, 2.38 to 32.70), more frequently had a family history of dementia (odds ratio, 3.61; confidence interval, 1.09 to 11.96) and laboratory evidence of proteinuria (odds ratio, 3.66; confidence interval, 1.54 to 8.71), had lower scores on neuropsychological tests, had more neurologic signs and symptoms, and were more functionally impaired in activities of daily living. Multiple logistic regression analysis showed that advanced age, lower educational attainment, history of myocardial infarction, and recent cigarette smoking were positively associated with case status and systolic blood pressure level was negatively associated with case status. CONCLUSIONS: Cardiovascular disease risk factors may be modifiable predictors of dementia associated with cerebral infarction. Additional well-designed epidemiologic studies are needed to clarify these associations.
Black or African American↗
Rapid karyotyping in ectopic pregnancies.
The aim of this study was to determine the feasibility of karyotyping ectopic Fallopian tube pregnancies utilizing dividing cytotrophoblast cells. Villi from 78 ectopic conceptuses were processed by the direct chromosome technique and cytogenetic diagnosis was successful in 60 cases (76.9 per cent). The amount of villi obtained, as well as villus morphology, was correlated with cytogenetic success rate. Histological examination of the Fallopian tube was also carried out. A total of 47 cases were chromosomally abnormal (78.3 per cent), which is the highest frequency of cytogenetic abnormalities reported to date.
Chorionic Villi Sampling↗
What may be gained from neuropsychological investigations of tardive dyskinesia?
As an iatrogenic movement disorder, tardive dyskinesia (TD) offers a unique opportunity to study brain-behavior relationships. The authors provide a brief overview of TD and discuss its association to cognitive dysfunction. It is argued that, given the complexity of the variables involved in the study of TD, there is pressing need for greater applications of neuropsychological research paradigms to help elucidate this disorder.
Antipsychotic Agents↗
Organic brain dysfunction and cognitive deficits in young schizophrenic patients with tardive dyskinesia.
Tardive dyskinesia (TD) has been associated with cognitive deficits, especially in older psychiatric patients on neuroleptic medication. This study investigated the relationship between presence of TD, organic brain dysfunction (OBD), and cognitive deficits in young psychiatric outpatients maintained on minimal doses of oral neuroleptics, with anticholinergics prescribed only on as-needed basis. Sixty-four patients, aged 20-39 years, were evaluated for the presence of abnormal movements, localizing and nonlocalizing physical signs, and deficits in memory, ability to shift, and sustained attention. Sixteen patients showed definite signs of TD. Significant associations were found between TD and OBD, and between cognitive deficits and OBD, but not between TD and cognitive deficits. Significant regression predictors of TD were the interaction between OBD and previous dystonia, as well as duration of neuroleptic treatment. These findings suggest that some potential risk factors for TD already identified in the literature also apply to younger patients with relatively shorter exposure to neuroleptics. However, the results indicate that the relationship between movement disorders and cognitive deficits may be more apparent in older patients.
Adult↗
Mental rotation, mental representation, and flat slopes.
The "mental rotation" literature has studied how subjects determine whether two stimuli that differ in orientation have the same handedness. This literature implies that subjects perform the task by imagining the rotation of one of the stimuli to the orientation of the other. This literature has spawned several theories of mental representation. These theories imply that mental representations cannot be both orientation-free and handedness-specific. We present four experiments that demonstrate the contrary: mental representations can be both orientation-free and handedness-specific. In Experiment 1 we serendipitously discovered a version of R. N. Shepard and J. Metzler's (1971) "mental rotation" task in which subjects accurately discover the handedness of a stimulus without using "mental rotation," i.e., in which reaction time to compare the handedness of two forms is not a function of the angular disparity between the two forms. In Experiment 2 we generalize this finding to different experimental procedures. In Experiment 3 we replicate this finding with a much larger group of subjects. In Experiment 4 we show that when we preclude the formation of an orientation-free representation by never repeating a polygon, subjects carry out the handedness comparison task by performing "mental rotation."
Adult↗
The gene for creatine kinase, mitochondrial 2 (sarcomeric; CKMT2), maps to chromosome 5q13.3.
YAC clones for the creatine kinase, mitochondrial 2 (sarcomeric; CKMT2), gene were isolated. One of these YACs was localized on chromosome 5q13.3 by fluorescence in situ hybridization. A polymorphic dinucleotide repeat (heterozygosity 0.77) was identified within the seventh intron of the CKMT2 gene. Genotyping of CEPH families allowed positioning of CKMT2 on the multipoint map of chromosome 5 between D5S424 and D5S428, distal to spinal muscular atrophy (SMA) (5q12-q14).
Base Sequence↗
Prospects for the genetics of human longevity.
Longevity varies between and within species. The existence of species-specific limit to human life-span and its partial heritability indicate the existence of genetic factors that influence the ageing process. Insight into the nature of these genetic factors is provided by evolutionary studies, notably the disposable soma theory, which suggests a central role of energy metabolism in determining life-span. Energy is important in two ways. First, the disposable soma theory indicates that the optimum energy investment in cell maintenance and repair processes will be tuned through natural selection to provide adequate, but not excessive, protection against random molecular damages (e.g. to DNA, proteins). All that is required is that the organism remains in a sound condition through its natural expectation of life in the wild environment, where accidents are the predominant cause of mortality. Secondly, energy is implicated because of the intrinsic vulnerability of mitochondria to damage that may interfere with the normal supply of energy to the cell via the oxidative phosphorylation pathways. Oxidative phosphorylation produces ATP, and as a by-product also produces highly reactive oxygen radicals that can damage many cell structures, including the mitochondria themselves. Several lines of evidence link, on the one hand, oxidative damage to cell ageing, and on the other hand, energy-dependent antioxidant defences to the preservation of cellular homeostasis, and hence, longevity. Models of cellular ageing in vitro allow direct investigation of mechanisms, such as oxidative damage, that contribute to limiting human life-span. The genetic substratum of inter-individual differences in longevity may be unraveled by a two-pronged reverse genetics approach: sibling pair analysis applied to nonagenarian and centenarian siblings, combined with association studies of centenarians, may lead to the identification of genetic influences upon human longevity. These studies have become practicable thanks to recent progress in human genome mapping, especially to the development of microsatellite markers and the integration of genetic and physical maps.
Aging↗
Giant cell reparative granuloma of the base of the skull in a 4-month-old infant--CT findings.
An unusual case of giant cell reparative granuloma of the base of the skull of a 4-month-old infant is described. Computerized tomography was useful in defining extent of the lesion and soft tissue abnormalities. Differential diagnosis with other giant cell lesions is discussed.
Bone Diseases↗
Age differences in immunity against wild and vaccine strains of poliovirus prior to the 1988 outbreak in Israel and response to booster immunization.
During the 1988 type 1 polio outbreak in Israel, most cases occurred in previously vaccinated subjects aged 11-30 years, suggesting a possible age-related immunity deficit against the wild virus responsible for the outbreak. We examined type 1 poliovirus neutralizing antibody titres against the Sabin strain, the standard wild strain (Mahoney), the wild strain responsible for the 1988 outbreak and a previous wild strain from the region, on frozen sera drawn prior to the mass vaccination campaign from subjects aged 6 to 40 years. Response to vaccination with oral poliovaccine (OPV) was examined in a subgroup aged 18-40 years. At all ages, the highest antibody titres prior to the outbreak were against the Sabin strain. Geometric mean titres (GMTs) against both the Sabin strain and the wild Mahoney strain were significantly higher in the age groups 6-7, 12-13 and 30-40 years compared with the 18-29-year-olds. For the other wild strains, the GMT for those aged 30-40 years was significantly and substantially higher than in the other age groups, followed by the 12-13- and 6-7-year-olds and lowest in those aged 18-29 years. Following vaccination with OPV in subgroups aged 18-29 and 30-40 years, GMTs against Sabin and all wild strains were similar to each other and in both age groups. These findings suggest that there was a relative immunity gap against the wild type 1 strains in the age group that lacked prior exposure to wild virus and had received the last OPV dose more than 17 years previously.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Localization of Friedreich ataxia phenotype with selective vitamin E deficiency to chromosome 8q by homozygosity mapping.
Friedreich ataxia and ataxia with selective vitamin E deficiency (AVED) share very similar clinical phenotypes. We have mapped the AVED locus to proximal 8q with only three large consanguinous Tunisian families, representing to our knowledge the first use of homozygosity mapping for primary linkage analysis. Subsequently, three additional families showed linkage with the same markers. A maximum lod score of 17.9 was obtained at theta = 0 for the haplotype D8S260-D8S510, consisting of the two closest markers. With only 6 families, the AVED locus is therefore mapped precisely as illustrated by the lod-1 confidence interval of 2.4 cM on either side of D8S260-D8S510. Isolation of a yeast artificial chromosome contig > 800 kilobases (kb) showed that D8S260 and D8S510 are less than 400 kb apart.
Adult↗
Psychopathology associated with Alzheimer's disease and related disorders.
BACKGROUND: This study compared the occurrence of psychiatric symptoms in a large group of community-residing participants enrolled in an Alzheimer's disease patient registry who met clinical diagnostic criteria for Alzheimer's disease or multi-infarct dementia, as well as mixed Alzheimer's disease and multi-infarct dementia. METHODS: Psychiatric morbidity observed from a psychiatric examination of 514 patients with Alzheimer's disease, 135 patients with multi-infarct dementia, and 86 cases with mixed dementia was analyzed using analysis of variance comparing symptoms across groups and chi-square test for differences in frequency of occurrence. Associations between pairs of symptoms were also reported. RESULTS: The frequency of occurrence and patterns of psychiatric problems were similar in patients with Alzheimer's disease and multi-infarct dementia. Agitation was the most frequent symptom, followed by depression, apathy, and behavioral disorders. Patients with mixed dementia had significantly more psychopathology. CONCLUSION: This study demonstrated that significant psychopathology occurs in individuals with Alzheimer's disease or multi-infarct dementia. The high levels of symptoms in mixed dementia suggest that the two conditions have a synergistic effect on behavioral problems. The prevalence of multiple symptoms is higher than previously reported.
Aged↗
Exclusion of the 15q locus as a candidate gene for severe childhood autosomal recessive Duchenne-like muscular dystrophy in Brazilian families.
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Adolescent↗
Relationship between Charcot-Marie-Tooth 1A and Smith-Magenis regions. snU3 may be a candidate gene for the Smith-Magenis syndrome.
The juxtacentromeric region of the human chromosome 17 short arm (17p11.2-p12) contains genes involved in the Charcot-Marie-Tooth type 1A disease (CMT1A) and the Smith-Magenis syndrome (SMS). CMT1A is associated with a duplication of a short segment whereas SMS is linked to microdeletions, extending toward the centromere. We describe the construction and analysis of a 5 Mb YAC contig spanning the CMT1A duplicated segment and the distal part of four SMS microdeletions. We concluded that the YAC contig contains about 1Mb of genomic DNA which is deleted in the four SMS patients analysed. Moreover two YACs contain both STS deleted in SMS (U3) and STS duplicated in CMT1A (5H5), but the proximal breakpoint associated with the CMT1A duplication is not the same as the distal SMS breakpoint we studied. Finally we located five new STS in SMS deletion. Two of them, a microsatellite (D17S805(23)) and the gene coding for small nuclear RNA U3, have been localized in the contig we described. We may also note that snU3 is the first expressed sequence localized in an SMS deletion so far. The possible participation of this gene in the SMS phenotype is discussed.
Base Sequence↗
Ethnic and gender differences in the prevalence of anti-cytomegalovirus antibodies among young adults in Israel.
The population of Israel comprises offspring of immigrants from countries of high and low incidence of cytomegalovirus infection. To evaluate possible ethnic differences in the prevalence of antibodies against cytomegalovirus in young adults, blood samples were taken from a random sample of 422 Israel military recruits aged 18-19 years, during 1987. Antibodies against cytomegalovirus were determined by means of ELISA. Subjects originating from North Africa or Asia had higher prevalences than those originating from Western countries (84.0% and 74.0% versus 60.0%, P < 0.001) and the differences persisted after adjustment for gender, education and socioeconomic status. The prevalence of antibodies was significantly lower in men than in women (63.1% versus 76.5%). These findings identify subpopulations who are at increased risk of primary cytomegalovirus infection during adulthood and may be candidates for future anti-cytomegalovirus vaccines.
Adolescent↗
Depression of the immune response to an inactivated hepatitis A vaccine administered concomitantly with immune globulin.
Inactivated hepatitis A virus (HAV) vaccine is given in a three-dose schedule. When rapid protection is needed, injection of immune globulin (IG) concomitantly with the first dose could provide passive protection until adequate active antibody response has developed. A possible effect of IG on the immune response to the vaccine was studied in healthy volunteers; 28 received vaccine alone, and 34 received the first dose simultaneously with 5 mL of IG. A control group received hepatitis B vaccine, and a fourth group received IG alone. Four weeks after the first vaccine dose, all subjects had detectable ELISA anti-HAV antibodies. Several weeks after each vaccine dose, the geometric mean titer of antibodies was significantly lower in those who received vaccine with IG but higher than in those who received IG alone. Results for neutralizing antibodies yielded a similar trend. If IG is given with HAV vaccine, a further booster vaccine dose may be required to ensure long-lasting immunity.
Adult↗
Integrated mapping across the whole human genome.
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Chromosome Mapping↗
Sex differences in the psychiatric manifestations of Alzheimer's disease.
OBJECTIVE: To test the null hypothesis, ie, that there are no gender differences in psychiatric problems manifest in patients with Alzheimer's disease. DESIGN: Survey. SETTING: Patients living in the community and evaluated at Alzheimer's disease and geriatric outpatient programs. PATIENTS: Three hundred twenty-eight women and 186 men clinically diagnosed with Alzheimer's disease using NINCDS/ADRDA or DSM-III-R criteria. MEASUREMENTS: Psychiatric signs and symptoms recorded following a psychiatric interview, including the Hamilton Depression Rating Scale. RESULTS: Approximately two-thirds of both men and women had psychiatric problems, but women had significantly more multiple symptoms. When pairs of symptoms were analyzed for independence, agitation was only significantly associated with paranoia in men, whereas in women agitation was significantly associated with most other psychiatric problems. CONCLUSION: The higher prevalence of multiple psychiatric problems in women may be due to many factors, including sociodemographic influences, physician bias, and/or other differences between men and women. The finding of a different pattern of association of symptoms with agitation in men and women deserves replication.
Aged↗