Simcha Pollack

Factors affecting recurrence following resection for Crohn's disease

The records of 187 patients with Crohns disease who underwent resectional surgery were analyzed to evaluate the effect of several clinical and histologic features on the recurrence rate. Recurrence was defined as the need for re-resection. The data were analyzed by the life-table method. Age, sex, age at onset of disease and at time of resection, family history, presence of granuloma, and microscopic involvement at the line of resection did not affect the recurrence rate. The distribution of the disease and duration of symptoms before primary resection did influence the rate of re-resection. Patients with predominantly large bowel disease (N=56) were found to have a higher rate of re-resection (45 percent) when compared with 32 percent in patients with small bowel involvement (N=94) and with 35 percent in patients with both small and large bowel involvement (N=37) (P=0.04). a detailed review, an analysis of the literature, and a comparison with our results are made.

Depression in Hemodialysis Patients

Psychiatric evaluation of depression in medically ill patients using DSM-III-R or Research Diagnostic Criteria (RDC) is difficult because these diagnostic systems have not been validated for this population. Diagnosis of depression has been especially problematic in patients with end-stage renal disease (ESRD). This study found a 17.7% prevalence of RDC-defined minor depression and a 6.5% prevalence of major depression in 124 ESRD patients treated with hemodialysis. Vegetative symptoms of depression were less useful for discriminating between those with and without depression than were the psychological symptoms of suicidal ideation, depressed mood, and discouragement.

Subject selection biases in clinical trials : Data from a multicenter schizophrenia treatment study

To evaluate subject selection biases in clinical trials, demographic characteristics (gender, race, and age) of subjects at different phases of evaluation for a multicenter maintenance trial in schizophrenia were examined. Six thousand twelve diagnostically appropriate subjects were screened for the study; of these, 1,320 met eligibility criteria and 528 (9% of the screened sample) entered the study. Women, blacks, and older subjects were more likely not to meet eligibility criteria; women and older subjects were more likely and blacks were less likely to refuse study participation. Overall, compared with the screened population, the sample of subjects who entered the study contained proportionately fewer women (33 vs. 43%), more blacks (48.5 vs. 41%), and fewer older subjects (mean age of the entered sample was 29.4 +/- 7.4 vs. 34.8 +/- 11.3 years for the screened population). Having identified these selection factors, a second goal was to assess the potential clinical relevance of selection biases of these magnitudes on clinical trials using models of hypothetical studies with different degrees of selection bias. These showed that selection biases would rarely change overall study outcomes to a clinically relevant degree. However, in our models, selection biases did limit the ability to make inferences about results for select small subgroups of the study population. Investigators should consider collecting data on the recruitment process to allow estimation of the effects of selection biases on the generalizability of their findings.

Expressed emotion and the course of late-life depression.

This study examined rates of expressed emotion (EE) indexed by the Five Minute Speech Sample (FMSS; A. B. Magana et al., 1986) in adult children or spouses of 54 elderly patients hospitalized for major depressive disorder. It also examined whether EE was related to course of psychiatric illness in these elderly patients over 1 year. Among the family members, 40% were classified as high EE. EE was not significantly related to relapse in the total sample. However, there was an interaction between EE and relationship to the patient (i.e., spouse or adult child) on 1-year clinical outcomes of the elderly. Among adult children caring for older patients, high-EE status predicted higher rates of patient relapse and lower rates of complete and sustained recovery from depression than low EE. In contrast, there was a trend association among spouses between high EE and lower rates of relapse as well as higher rates of complete and sustained recovery.

Clozapine pharmacology and tardive dyskinesia.

Clozapine, an atypical neuroleptic, does not cause extrapyramidal symptoms of Parkinsonism and dystonia and appears to have a reduced or absent capacity to produce tardive dyskinesia. 37 subjects, most with chronic schizophrenia, were treated with clozapine and TD outcome was analyzed. A subset of these subjects underwent plasma and CSF studies. TD response was heterogenous, but a proportion of patients improved with clozapine treatment. Neurochemical data differed from published reports of classical neuroleptics with the most robust effect produced by clozapine seen in CSF norepinephrine levels. Other neurochemical data and implications for the mechanism of clozapine in TD are reviewed.

Pharmacologic characterization of tardive dyskinesia.

Tardive dyskinesia (TD) occurs in approximately 20% of patients treated chronically with antipsychotic drugs and constitutes a major public health problem. The cause of this disorder remains unknown, and no effective treatment has yet been found. The major etiologic theory (dopamine [DA] supersensitivity hypothesis) suggests that TD is the pharmacologic opposite of Parkinsons disease and implies that all patients with TD should respond uniformly to specific pharmacologic agents. Clinical research, however, has not borne this out. To evaluate pharmacologic response in TD syndromes, 15 patients underwent single dose acute administration of four different drugs: a DA agonist (bromocriptine 5 mg orally), a DA antagonist (haloperidol 5 mg intravenously), a cholinergic agonist (physostigmine 2 mg intravenously) and a cholinergic antagonist (benztropine 4 mg intravenously), individually in separate procedures at weekly intervals for four consecutive weeks in randomized order and under controlled double-blind conditions. Patients were evaluated for their clinical and endocrine responses. Pre- and post-drug administration TD exams were blindly rated. Results were not consistent with the DA supersensitivity theory; instead they demonstrated marked inter- and intrasubject variability in pharmacologic responses. Greatest uniformity in response was found among the tardive dystonic subjects, although this also was not consistent with a DA supersensitivity hypothesis. TD appears to be a pharmacologically heterogeneous condition, which may reflect the neurochemical complexity of the basal ganglia.

Pharmacologic studies of tardive dyskinesia.

Based on the results of two preliminary studies, we concluded that late-developing persistent drug-induced movement disorders are pharmacologically heterogeneous, and this heterogeneity is seen between individual patients (and groups of patients) as well as within body areas of individual patients; dystonic pathology has a distinct and more consistent response to pharmacologic stimulation than does nondystonic tardive dyskinesia (TD); and, although disturbances in dopamine and acetylcholine appear to be involved in these disorders, they do not in all cases exist in functionally opposite relationships. The observed pharmacologic heterogeneity in TD response reflects the limitations of the dopamine/acetylcholine model of TD, which oversimplifies the neuroanatomy of the basal ganglia and the pathophysiology of TD. The chemical and anatomical complexity of this region suggests that other neurotransmitter systems and neuronal circuits within and extending from the basal ganglia may be disturbed in the pathogenesis of TD.

A visual approach to statistical power analysis on the microcomputer

Computer programs for statistical power analysis typically require the user to provide a series of values and respond by reporting the corresponding power. These programs provide essentially the same functions as a published text, albeit in a more convenient form. In this paper, we describe a program that instead uses innovative graphic techniques to provide insight into the interaction among the factors that determine power. For example, fort tests, the means and standard deviations of the two distributions, sample sizes, and alpha are displayed as bar graphs. As the researcher modifies these values, the corresponding values of beta (also displayed as a bar graph) and power are updated and displayed immediately. By displaying all of the factors that are instrumental in determining power, the program ensures that each will be addressed By allowing the user to determine the impact that any modifications will have on power, the program encourages an appropriate balance between alpha and beta while working within the constraints imposed by a limited sample size. The program also allows the user to generate tables and graphs to document the impact of the various factors on power. In addition, the program enables the user to run on-screen Monte Carlo simulations to demonstrate the importance of adequate statistical power, and as such, it can serve as a unique educational tool.

Erythropoietin and visual hallucinations in patients on dialysis

The authors encountered five patients who first had visual hallucinations while taking erythropoietin. Since this association had not previously been reported, the authors studied a convenience sample of dialysis patients at two institutions to determine the incidence of visual hallucinations in patients on erythropoietin and possible associated risk factors. Eleven percent of the patients had visual hallucinations at one institution with no other factor than erythropoietin as a probable cause and 2% at the other. Significant risk factors for hallucinations included diabetic retinopathy or cataracts (chi 2 = 4.59, df = 1, P = 0.032) and older age (t = 2.24, df = 123, P = 0.27). A multivariate analysis comparing visual hallucinations, eye pathology, and age showed that eye pathology was close to the trend level of significance but that age maintained significance as a risk factor. The visual hallucinations occurred in response to the administration of erythropoietin and appeared to vary in relation to dose. Similarities between the syndrome of visual hallucinations in dialysis patients taking erythropoietin and the syndrome of visual hallucinations in dialysis patients taking erythropoietin and the Charles Bonnet syndrome are discussed.

A profile of obsessive compulsive symptoms in schizophrenia

(n == 226) of male schizophrenics and a group of healthy male controls (n = 142) equivalent in parental education and socioeconomic status. The mean height of the patients (177.0 em) was significantly shorter (p<0.OO5) than the mean height of the controls (179.4 em). Within the patient group, those in the lower quartile of height compared to the upper quartile had significantly poorer premorbid function as measured by: I) social relationships (t = 2.46, p<0.007); 2) school performance measured by grades (t= 1.81 p<0.036) and need for special education (t= 1.78, p<0.002); and 3) estimate of pre-morbid VIQ using the NART (t==2.2, p<0.02). In addition, when the whole patient sample was analyzed these measures of premorbid function, as well as a measure of motor development (age at which child first walked), correlated significantly with height. These findings provide additional support for the hypothes is that schizophrenia may occur as a consequence of neurodevelopmental factors. Furthermore, this is manifested as a global deficit in growth and function resulting in smaller stature, slower motor development, poorer social skills and deficit in cognitive abilities. ..~ A PROFILE OF OBSESSIVE COMPULSIVE SYMPTOMS IN SCHIZOPHRENIA