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Biomedical subjects

I L Cohen

Publications and source records attributed to I L Cohen.

71 records · Page 4Linked to original sources

A controlled crossover study of triiodothyronine in autistic children.

A placebo-controlled crossover study of behavioral effects of triiodothyronine (T3) was conducted in 30 young clinically euthyroid autistic children. Multiple independent raters and multiple rating scales were used. Except for a few symptoms that were reduced on T3, the drug did not differ from placebo. Time itself accounted for most of the improvement in the whole sample. As a group, the lower IQ children responded to T3. The individual children who were responders could not be defined by any parameter.

Autistic Disorder↗

The reinforcement value of schedule-induced drinking.

The effect of food reinforcement schedules on the reinforcement value of drinking water was evaluated. Food-deprived rats were exposed to concurrent, identical variable-time schedules of food presentation, the food thus being delivered independently of the rats' behavior. When the relative amount of time spent in a schedule component stabilized, an opportunity to drink water was introduced into one schedule component. The value of the variable-time schedules was varied from 60 to 90 to 270 sec. The relative amount of time spent in the schedule component associated with drinking water was a decreasing function of food frequency for two animals and remained constant for the third. Drinking rates were direct functions of food frequency, and the amount of water drunk per pellet was an inverse function of food frequency. The reinforcement value of drinking water, according to the Matching Law, was a direct function of the frequency of food presentation. It was concluded that food reinforcement schedules indirectly influence rates of drinking by altering the reinforcement value of drinking water and that certain properties of schedule-induced drinking can be accounted for in terms of the reinforcement value of drinking water, the rate of drinking, and the frequency of food presentation.

Journal Article↗

High dose folic acid treatment of fragile (X) males.

We conducted an experimental trial of high-dose folic acid given to five males, ages 8 to 26 years, with the fra(X) syndrome. In this double blind study, each subject received 250 mg per day of folic acid for 3 months, followed by placebo for 3 months, and folic acid again for an additional three months. Based on IQ tests, behavior ratings, the Autistic Descriptors Checklist, and parental ratings, there was little evidence to suggest any positive effects seen during the administration of high-dose folic acid. Therefore, this study has provided little support for a hypothesis of benefit of high-dose folic acid in the treatment of the fra(X) syndrome.

Adolescent↗

Fragile X and autism: a multicenter survey.

We screened 183 autistic males for the fra(X) and found 24 (13.1%) to be positive. Adding the subjects of this study to those of 11 other surveys, of which 6 were positive and 5 were negative, a total of 614 autistic males have been screened. Overall 47 (7.7%) were positive. Based on this estimate and the prevalence of autism and fra(X), we estimate that 12.3% of fra(X) males are autistic. We have found that 17.3% of our fra(X) males were autistic and overall a 21.2% frequency has been reported, these higher figures are most likely due to biases in age and ascertainment. With an overall 7.7% frequency of fra(X) among autistic males and an estimated 12.3% of autism among fra(X) males, we conclude there is likely to be a significant association of fra(X) with autism. Because fra(X) appears to be the single most common cause of the condition, chromosomal testing is recommended for any autistic person with undiagnosed etiology.

Autistic Disorder↗

Folic acid treatment of fragile X males: a further study.

Investigations of the effect of high dose folic acid treatment of fragile X syndrome in males has produced mixed results. However, no study had examined the possible drug effects of folic acid on non-fragile X control males. Therefore, we examined the effect of folic acid on fragile X males using non-fragile X control males. Subjects were assigned randomly to an ABA or BAB design. Duration of either folic acid or placebo condition was 4 months. Folic acid or placebo was given in a double-blind fashion. At the end of each condition, the subjects' behavior was assessed. At the end of the study, parents were asked to complete a questionnaire. Using parents' responses, we examined 22 items on the Autistic Descriptors Checklist and two subscales from the Vineland Adaptive Behavior Scale which corresponded to areas of behavior parents' noted to have shown improvement. We did not find significant differences between fragile X males and control males, within subjects, nor across folic acid and placebo conditions. Thus, our follow-up study confirms and extends our original findings, as well as those of other researchers: namely, that no dramatic changes in behavior result from high dose folic acid. Moreover, subtle improvements observed in earlier investigations were not confirmed.

Adolescent↗

Screening developmentally disabled male populations for fragile X: the effect of sample size.

The fra(X) or Martin-Bell syndrome is the most common cause of inherited mental retardation (MR) in males. It is also associated with a variety of unusual behavioral and developmental disorders. Recent studies found great variability in the estimated strength of association between "autism" and the fra(X) syndrome, but not between MR and fra(X). We examined 31 studies which investigated the association of fra(X) syndrome with either MR or "autism" and found that the conclusion of those researchers could be significantly affected by sample size. Different behavioral and cytogenetic protocols will also influence the strength of association between fra(X) and autism.

Autistic Disorder↗

Syntactic delay and pragmatic deviance in the language of fragile X males.

The expressive language of 19 fragile X [fra(X)] males with chronological ages between 5 and 36 years and Vineland Adaptive Behavior Scores between 21 and 79 was examined for syntactic as well as pragmatic proficiency. The production of deviant repetitive language was observed with this group, corroborating the results of an earlier study with a smaller sample of fra(X) males. In contrast, when 2 syntax scores, mean length of utterance (MLU), and Index of Productive Syntax (IPSyn) were derived from naturalistic language observations, the relation of complexity to length was observed to be very similar to the known relationship of these 2 facets of syntactic ability in normal preschoolers. These results, and the absence of correlations between syntactic scores and proportions of deviant repetitive language are consistent with the notion that the syntactic development of fra(X) males is typically delayed rather than deviant. For effective assessment and remediation of communicative problems associated with the syndrome to be developed, it is argued, language must be considered as a combination of competencies rather than as a unitary skill.

Adolescent↗

Effects of age and communication level on eye contact in fragile X males and non-fragile X autistic males.

Dyadic social gaze and eye contact were examined in fragile X [fra(X)] males and in non-fra(X) autistic males as a function of age and level of communicative ability. Lag sequential analysis showed that responsive eye contact was highly correlated with age and communicative ability in non-fra(X) autistic males but not in fra(X) males. Older, more communicative non-fra(X) autistic males exhibited more responsive eye contact than their fra(X) cohorts. Implications of these observations for theory and intervention are discussed.

Age Factors↗

Brief screening questionnaire for determining affected state in fragile X syndrome: a consensus recommendation.

New molecular research has provided strong evidence for different forms of the fragile X mutation. These findings suggest the need to develop a more standardized and sensitive method for determining neurobehavioral effects of the fragile X gene(s), particularly for molecular studies of patients who do not have obvious mental retardation. This report describes a brief screening questionnaire designed to increase the detection of neurobehavioral dysfunction in individuals from fragile X families who are included in new molecular studies. Improved detection of the affected state in fragile X syndrome will allow more valid clinical data to be correlated with the important molecular information currently being collected.

Behavior↗

Mode of inheritance influences behavioral expression and molecular control of cognitive deficits in female carriers of the fragile X syndrome.

The effect of mode of inheritance on expression of fragile X syndrome [fra(X)] was investigated in nonretarded female carriers. Examination included cognitive and molecular measures. A priori predictions about cognitive impairment and size of an unstable region of DNA containing a CGG repeat on the X chromosome were tested in age and education matched heterozygotes grouped according to parental inheritance. Nine carriers with a maternal fra(X) chromosome, 11 carriers with a paternal fra(X) chromosome and 15 control mothers of children with non X-linked developmental disabilities were tested. Inheritance was established through DNA linkage analysis. Cognitive skills were assessed using the Wechsler Adult Intelligence Scale-Revised and the Benton Visual Retention Test. Molecular status was assessed by Southern blot analysis of genomic DNA digested with Eco RI and Eag I, and probed with StB 12.3. Results supported the inheritance models' predictions. Heterozygotes who inherited the fra(X) from their fathers appeared to be a homogeneous group. They were indistinguishable from controls on cognitive measures and all had genomic insertions of less than 500 base pairs. In contrast, heterozygotes who inherited the fra(X) chromosome from their mothers appeared to be made up of 2 sub-populations. They were as a group deficient in measures of attention and visual memory, but not other measures, with scores of some women consistently below the other subjects. Further, they had some members with greater than 500 base pair inserts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Reducing resource consumption through work redesign in a surgical intensive care unit: a multidisciplinary, protocol-based Progressive Care Area.

Patients with prolonged intensive care unit (ICU) length of stay, though few in number, consume as much as 50% of ICU resources. With increasing pressures for cost containment in health care, the availability of ICU beds may be jeopardized. To improve the efficiency of care for patients requiring a surgical intensive care unit (SICU) stay of 3 or more days, a multidisciplinary, highly "protocolized," Progressive Care Area was developed within the existing SICU environment. Entry into this area is limited to patients whose acuity level is not high by ICU standards, but too high for a general surgical floor. In designing the Progressive Care Area, we drew on a number of published management strategies-including total quality management concepts and our prior experience in establishing ventilator management teams. The Progressive Care Area has resulted in a reduction in both the frequency and variation of resources used. A Progressive Care Area within an existing ICU is a viable alternative for the care of the patients who have prolonged lengths of stay and are less acutely ill, and it significantly improves ICU efficiency.

Data Collection↗