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Biomedical subjects

D J Cohen

Publications and source records attributed to D J Cohen.

At least 163 records · Page 9Linked to original sources
PubMed1995

Progressive renal insufficiency following cardiac transplantation: cyclosporine, lipids, and hypertension.

The increasing success of cardiac transplantation has been attributed to the availability of potent immunosuppressive agents, including cyclosporine. With improved graft and patient survival, the incidence of chronic renal insufficiency has increased. We reviewed the medical records of patients who had undergone orthotopic cardiac transplantation and had been followed for at least 3 years posttransplantation to determine the risk factors at initial evaluation and in the early posttransplantation period for subsequent renal insufficiency. We followed 80 adult patients over a mean period of 4.7 years: 39 patients had a serum creatinine > or = 2.4 mg/dL at last follow-up (renal insufficiency or RI group); 41 patients had a serum creatinine < or = 1.7 mg/dL at last follow-up (controls). RI patients tended to be older and had a lower mean glomerular filtration rate (GFR) at initial evaluation. There were no differences in race, gender, or previous history of hypertension between the two groups. Although both groups experienced an improvement in GFR at transplantation and a subsequent decline in GFR by 6 months posttransplantation, the RI group achieved a lower peak GFR at transplantation and a far lower mean GFR at the 6-month analysis. Only the RI group showed a continued decline in GFR. The RI group had more severe hypertension and required a significantly greater number of antihypertensive medications. The RI group had a higher mean total cholesterol at 6 months, but this difference was not sustained. They also had higher triglyceride levels and lower high-density lipoprotein (HDL) levels; there was no difference in low-density lipoprotein (LDL) levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Ethical issues in biological psychiatric research with children and adolescents.

OBJECTIVE: This article reviews, discusses, and elaborates considerations and recommendations summarized by the biological research working group at the May 1993 NIMH conference on ethical issues in mental health research on children and adolescents. METHOD: Notes from the conference were summarized and supplemented by a computer search of relevant literature. Drafts were circulated for comment to national and international experts, some of whom joined as coauthors. RESULTS: Issues addressed include possible overprotection by policy makers and institutional review boards arising out of the recognition of children's special vulnerability without equal recognition of their need for research; the definition of minimal risk, which has often been equated with no risk in the case of children; assessment of the risk-benefit ratio; procedures for minimization of risk, such as improved technology, "piggybacking" onto clinical tests, and age-appropriate preparation; the difficulty of justifying risk for normal controls; age-graded consent; special considerations about neuroimaging; "coercive" inducement, both material and psychological; disposition of unexpected or unwanted knowledge about individuals, including the subject's right not to know and parent's right not to tell; and socioeconomic status and cultural/ethnic equity. CONCLUSIONS: The working group adopted a position of advocacy for children's right to research access while recognizing that this advocacy must be tempered by thoughtful protections for child and adolescent subjects.

Adolescent↗
PubMed1995

Guanfacine treatment of comorbid attention-deficit hyperactivity disorder and Tourette's syndrome: preliminary clinical experience.

OBJECTIVE: Many children with Tourette's syndrome (TS) are handicapped more by difficulties with inattention, impulsivity, and hyperactivity than by their tics. However, stimulant medications used to treat attention-deficit hyperactivity disorder (ADHD) can exacerbate tics. Guanfacine is an alpha 2-adrenergic agonist that may have beneficial effects on attention, without the hypotensive or sedative effects of clonidine, which is often used as an alternative to stimulants. METHOD: An open-label study of guanfacine was performed in 10 children with TS+ADHD, aged 8 to 16 years. The duration of follow-up was 4 to 20 weeks, and the majority of subjects were treated with 1.5 mg/day. Ratings of tic severity and ADHD symptoms were obtained using the Yale Global Tic Severity Scale (YGTSS), the Tic Symptom Self Report (TSSR), and the Conners Parent Rating Scale. In addition, blind Continuous Performance Tests (CPTs) were performed at baseline and at two follow-up intervals in eight subjects. RESULTS: Guanfacine was associated with significant decreases in both commission errors (p < .02) and omission errors (p < .01) on the CPT. In addition, guanfacine caused a significant decrease in severity of motor (p < .02) and phonic (p < .02) tics as measured by the TSSR and the YGTSS, respectively. The most common side effects were transient sedation and headaches. CONCLUSION: Guanfacine may provide a safe alternative therapy for children with ADHD in the presence of tics. Future double-blind, controlled trials should be undertaken.

Adolescent↗
PubMed1995

An epidemiological study of trichotillomania in Israeli adolescents.

OBJECTIVE: To determine the prevalence of trichotillomania and comorbid psychopathology in nonreferred adolescents. METHOD: Using a questionnaire and interview, 794 Israeli 17-year-olds were screened for current and past hair-pulling and comorbid psychopathology. RESULTS: Eight current or past hair-pullers (5 male, 3 female) were identified, yielding a lifetime prevalence of hair-pulling of 1%. Four subjects reported current hair-pulling (point prevalence of 0.5%). None of these reported alopecia, distress, or tension before pulling; only two reported relief after pulling. Thus, none met the full DSM-III-R criteria for trichotillomania. Four subjects reported past but not current hair-pulling, with bald spots in two cases. Three of the four current hair-pullers had significant obsessive-compulsive symptoms, a significantly elevated rate compared to the entire screened population. Two subjects with obsessive-compulsive disorder also had generalized anxiety disorder and, in one case, chronic simple vocal tics. Hair-pullers did not differ significantly from non-hair-pullers in IQ, physical fitness, and overall competency, or prevalence of other comorbid disorders. CONCLUSIONS: In a community adolescent sample, only 25% of hair-pullers reported resulting bare spots and none endorsed both rising tension and subsequent relief. The prevalence of obsessive-compulsive symptoms was significantly elevated in these nonreferred hair-pullers.

Adolescent↗
PubMed1995

A case-controlled study of repetitive thoughts and behavior in adults with autistic disorder and obsessive-compulsive disorder.

OBJECTIVE: The purpose of this study was to investigate the types of repetitive thoughts and behavior demonstrated by adults with autistic disorder and compare them with those of age- and sex-matched adults with obsessive-compulsive disorder. METHOD: Fifty consecutive patients admitted to the Yale Adult Pervasive Developmental Disorders (Autism) Clinic with a primary diagnosis of autistic disorder (DSM-III-R and DSM-IV) completed the symptom checklist of the Yale-Brown Obsessive Compulsive Scale. Types of current obsessions and compulsions were evaluated. The comparison group consisted of 50 age- and sex-matched adults with obsessive-compulsive disorder (without tics) (DSM-III-R and DSM-IV). RESULTS: Direct discriminant function analysis showed that the patients with autistic disorder could be distinguished from those with obsessive-compulsive disorder on the basis of the types of current repetitive thoughts and behavior that they demonstrated. Compared to the obsessive-compulsive group, the autistic patients were significantly less likely to experience thoughts with aggressive, contamination, sexual, religious, symmetry, and somatic content. Repetitive ordering; hoarding; telling or asking (trend); touching, tapping, or rubbing; and self-damaging or self-mutilating behavior occurred significantly more frequently in the autistic patients, whereas cleaning, checking, and counting behavior was less common in the autistic group than in the patients with obsessive-compulsive disorder. In addition, a specific subset of seven obsessive-compulsive variables from the Yale-Brown Obsessive Compulsive Scale symptom checklist was identified that reliably predicted membership in the autistic group. CONCLUSIONS: These results suggest that the repetitive thoughts and behavior characteristics of autism differ significantly from the obsessive-compulsive symptoms displayed by patients with obsessive-compulsive disorder. Future studies are warranted to assess the treatment response and neurobiological underpinnings of repetitive thoughts and behavior in patients with autism and obsessive-compulsive disorder.

Adolescent↗
PubMed1995

Regulation of macrophage growth responses to colony-stimulating factor-1 by 1,25-dihydroxyvitamin D3.

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has previously been shown to affect the biology of a variety of immune cells, including the functions of macrophages. The effect of the vitamin D metabolite on the proliferative responses of macrophages to the cytokine colony-stimulating factor-1 (CSF-1) has been studied. It was found that this substance was able to suppress the growth responses of macrophages to CSF-1 as assessed by macrophage-tritiated thymidine uptake and also by cell counts. The effect was specific to this vitamin D metabolite because another vitamin D analogue, 25 hydroxyvitamin D3, did not have a similar effect on the responses of such cells to CSF-1. The results yield information on the regulatory role of 1,25(OH)2D3 on macrophage growth. It would appear that this vitamin D metabolite may act as a negative autoregulatory cytokine because it is produced by the macrophage when it is activated. A schema can be envisaged where CSF-1 is delivered to the macrophage to activate it and to cause it to proliferate. In the process, it also secretes 1,25(OH)2D3, which exerts a suppressive action to dampen this response.

Animals↗
PubMed1995

Host immune deficiency in immune complex nephritis.

Evidence is reviewed that indicates that an immune deficiency state may underlie patients with immune complex nephritis. Studies in several laboratories provide data that show defective immune function in patients with nephritis at the following loci: defective immunoglobulin production, impaired monocyte Fc and C3b receptor function, diminished complement biosynthesis, and decreased mesangial cell colony-stimulating factor-1 biosynthesis. Aberrant monocyte function may be an important common denominator. The validation of this hypothesis has important implications for therapeutic strategies.

Animals↗
PubMed1995

Coronary stenting: costly or cost-effective?

In today's health care climate, decisions about new technologies need to reflect measures of cost as well as clinical benefit. By estimating the cost-effectiveness ratio for a new treatment compared to a current standard (e.g., stenting as compared to conventional PTCA), it is possible to decide whether the new treatment represents an efficient use of limited health care resources. In this analysis, stenting carried a $2500 greater in-hospital cost, which was partially defrayed by a $1900 savings in follow-up costs due to reductions in abrupt closure and restenosis. The net $600 increase in cumulative costs for stenting "bought" additional quality-adjusted life expectancy at a cost-effectiveness ratio of $33,700/QALY over conventional angioplasty, giving stenting a cost-effectiveness comparable to many other accepted medical therapies. Any future reduction in stent costs (e.g., by reducing length of stay or vascular complications) would improve this estimate of relative cost-effectiveness.

Angioplasty, Balloon, Coronary↗
PubMed1995

[Theoretical perspectives on autism].

The French and American views of autism have often been seen as irreconcilable, the theoretical and inferential aspects of one conflicting with the empiricism and positivism of the other. Nevertheless, multiple lines of convergence tie together these two traditions, from the commitment to phenomenology embodied in the early work of Jean Itard and his American disciples, to the emphasis on developmental issues represented in French psychoanalytic approach and Kanner's reliance on Gesell's work. Several important differences remain, with an oftentimes sharp contrast between the predominantly psychogenic views in France and the predominantly neurobehavioral views in the United States. This divergence has important implications to research and services affecting individuals with autism. However, recent developments are bringing together these two viewpoints, with mutual benefits. There is a renewed commitment to cross cultural discussions, resulting in constructive reappraisal of concepts and research in both countries, and leading to the attention to important phenomena. The stimulation engendered by this dialogue is leading to new research.

Autistic Disorder↗
PubMed1994

Elevation of the creatine kinase myocardial isoform following otherwise successful directional coronary atherectomy and stenting.

Moderate elevation of creatine kinase (CK) MB isoform is common following otherwise successful percutaneous coronary revascularization, and is frequently interpreted as evidence of a non-Q-wave myocardial infarction. It is not clear, however, whether elevation of CK MB isoform carries sufficient adverse clinical impact to be categorized as a "major" complication. We therefore explored the incidence and clinical consequence of elevation of CK MB isoform in a consecutive series of 565 patients who had otherwise successful directional coronary atherectomy (n = 274) or stenting (n = 291), and were followed for a mean of 2 years. Of this cohort, 11.5% had postprocedure elevation of the CK MB isoform above normal (10 IU/liter). These patients tended to be older and to have undergone atherectomy of a de novo lesion with adverse morphology (thrombus, calcification, eccentricity). Patients with elevation of CK MB isoform following otherwise successful revascularization generally showed no adverse long-term sequelae (death, recurrent myocardial infarction, repeat revascularization) compared with patients without elevation of CK MB isoform. Only 2.3% of the patients who had CK MB isoform release > 50 IU/liter demonstrated a trend (p = 0.08) toward decreased late survival, compared with patients without CK MB isoform elevation. While minor CK MB isoform elevation is common (11.5%) after successful coronary stenting or directional atherectomy, it generally has no adverse clinical consequences, and should not be considered a major complication.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Noradrenergic and adrenergic functioning in autism.

A neurochemical assessment of noradrenergic and adrenergic functioning was carried out with autistic patients and normal control individuals. Norepinephrine and related compounds were measured in autistic (n = 17 unmedicated, 23 medicated; age range 9-29 years old) and normal controls (n = 27; age range 9-36 years old). Plasma levels and urinary excretion of 3-methoxy-4-hydroxy-phenylglycol (MHPG) were measured, as were urinary excretion rates of norepinephrine (NE), epinephrine (EPI), and vanillylmandelic acid (VMA). No significant group mean differences were seen between the autistic and control groups. In both the autistic and control groups urinary excretion rates of norepinephrine and epinephrine were substantially higher in the afternoon-evening (5-11 PM) compared to the overnight (11 PM-7 AM) collection period. Based on our neurochemical assessment, marked abnormalities in basal noradrenergic functioning do not appear to be present in autism.

Adolescent↗
PubMed1994

Is 40% to 70% diameter narrowing at the site of previous stenting or directional coronary atherectomy clinically significant?

Traditional binary definitions of coronary restenosis based on 6-month continuous angiographic measurements (e.g., > 50% diameter stenosis) may give confusing results for lesions whose late percent stenosis falls near the arbitrary threshold. To determine the long-term clinical consequences of such lesions, the overall correlation between follow-up percent stenosis and the performance of subsequent ischemia-driven target vessel revascularization (triggered by significant angina or a positive exercise study result, or both) was examined in 443 consecutive lesions treated with directional coronary atherectomy or Palmaz-Schatz coronary stenting. Follow-up angiograms (available in 355 lesions, 82%) were stratified into 3 groups: severe late stenosis (> 70% stenosis, n = 59), moderate late stenosis (40% to 70% stenosis, n = 72), and minimal late stenosis (< 40% stenosis, n = 224). With an average clinical follow-up of 933 +/- 394 days, 92% of lesions in the "severe late stenosis" group were treated with ischemia-driven target vessel revascularization, compared with 0% of the lesions in the "minimal late stenosis" group. Ischemia-driven target vessel revascularization was performed in 38% of patients in the "moderate late stenosis" group. However, patients in this group who did not undergo revascularization (despite the fact that 43% of them had a late stenosis of > 50%) showed a similarly favorable long-term clinical outcome to patients with a minimal late stenosis. These results support a strategy of conservative management for the 20% of patients who have a moderate (40% to 70%) late stenosis after stenting or atherectomy, but do not have evidence of ischemia.

Atherectomy, Coronary↗