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Biomedical subjects

S Pollack

Publications and source records attributed to S Pollack.

At least 19 recordsLinked to original sources
PubMed1999

Investigation of frontal lobe subregions in first-episode schizophrenia.

The evidence for frontal lobe structural abnormalities in schizophrenia using magnetic resonance (MR) imaging has been mixed, but most studies used either single slice measures or total volumes of a single frontal region, neither of which is sensitive to potential volume differences in more specific subregions. This study employed reliable methods for parcellation of the frontal lobes from MR images based on the sulcal anatomy. Following a cytoarchitectonic theory that distinguishes dorsomedial (archicortically derived) from ventrolateral (paleocortically derived) frontal subregions, we measured the superior frontal gyrus, anterior cingulate gyrus, and orbital frontal region in 19 first-episode schizophrenia patients and 26 healthy comparison subjects. Results indicated that male patients had significantly larger right orbital frontal volume compared to their left orbital frontal volume and compared to healthy men. Among male patients larger right orbital frontal volume was significantly correlated with smaller right 'archicortical' (i.e. anterior cingulate and superior frontal gyri) volume. Furthermore, the ratio of right orbital frontal to right 'archicortical' volume was significantly and positively correlated with level of delusions among male patients. These findings suggest that there may be reciprocal controls on 'archicortical' and 'paleocortical' neurodevelopment among men with schizophrenia, and that larger paleocortical relative to archicortical volumes may be associated with increased delusions.

Brain↗
PubMed1999

Hippocampal/amygdala volumes in geriatric depression.

BACKGROUND: The hippocampus, amygdala and related functional circuits have been implicated in the regulation of emotional expression and memory processes, which are affected in major depression. Several recent investigations have reported abnormalities in these structures in adult and elderly depressives. METHODS: Elderly DSM-III-R unipolar depressives (N = 40) and normal controls (N = 46) participated in a magnetic resonance imaging study (1.0T). Brain images were obtained in the coronal plane. Using established anatomical guidelines for structure delineation, volumetric measurements of left and right hippocampus and anterior hippocampus/amygdala complex were completed under blinded conditions using a semi-automated computer mensuration system, with patients and controls in random order. RESULTS: Medial temporal volumes did not significantly distinguish either elderly depressed and age-similar normal control subjects, or late onset and early onset depressed patients (ANCOVA). Major overlap of measured volumes existed between patient and control groups. In depressives, hippocampal volumes significantly correlated with age, and cognitive and depression ratings, but not with number of prior depressive episodes or age-at-onset of first depression. CONCLUSIONS: Hippocampal volumes do not discriminate a typical clinical population of elderly depressed patients from age-similar normal control subjects. If hippocampal dysfunction contributes to a diagnosis of syndromal depression in the elderly, such dysfunction does not appear to be regularly reflected in structural abnormalities captured by volumetric measurement as conducted. On the other hand, relationships between hippocampal volumes and clinical phenomena in depressives, but not controls, suggest potentially meaningful interactions between hippocampal structure and the expression of major depression in the elderly.

Aged↗
PubMed1999

Cognitive and behavioral precursors of schizophrenia.

Attentional deficits are well-established characteristics of patients with schizophrenia and their at-risk offspring, suggesting a biological connection between attention and schizophrenia. The goal of this study is to clarify the developmental role of attention in the illness. Data has been collected from 87 subjects at high and low risk for schizophrenia who have participated in the New York High-Risk Project from 1977 to the present. Individuals are considered to be at high risk if either or both of their parents has schizophrenia. Analyses of attention and global behaviors, measured at intervals from about 12 to 26 years of age, indicate (a) attentional deficits can be reliably detected in high-risk children who will develop future schizophrenia-spectrum disorders (the prespectrum [PSP] group); (b) these deficits are stable, enduring over time, and appear to reflect a compromised attentional capacity; (c) attention is not affected by the onset of illness in the PSP group; (d) for all subjects, attention and global behaviors follow independent developmental pathways; and (e) behavioral difficulties, but not attention deficits, appear to be highly sensitive to environmental factors, especially rearing by a mentally ill parent. It is concluded that in PSP individuals impaired attention probably results from prenatal developmental abnormalities (possibly on the cellular level) and is likely to be a marker of a biological vulnerability to schizophrenia. In addition, attentional deficits, as opposed to early behavioral difficulties, are concluded to be a useful first step in screening for youngsters in need of early intervention.

Attention↗
PubMed1999

The staurosporine-like compound L-753,000 (NB-506) potentiates the neurotrophic effects of neurotrophin-3 by acting selectively at the TrkA receptor.

K-252b, a member of the staurosporine family of protein kinase inhibitors, selectively potentiates the activation of the nerve growth factor receptor, TrkA, by a nonpreferred ligand, neurotrophin-3 (NT-3), in a variety of cell types. At higher (micromolar) concentrations of K-252b, an inhibitory effect occurs because of the inhibitory action of K-252b on the Trk kinase. By examining analogs of K-252b, we identified the compound L-753,000 (NB-506), which potentiates the action of NT-3 on TrkA but is devoid of the inhibitory action of K-252b. L-753,000 was effective at nanomolar concentrations in a Chinese hamster ovary cell line that expressed TrkA but was devoid of p75, the low-affinity neurotrophin receptor. L-753,000 also potentiated the activation of mitogen-activating protein kinase signaling (downstream from Trk activation) by NT-3 in this cell line. Although L-753,000, like K-252b, had a negligible effect in the absence of NT-3, the compound was found to potentiate NT-3-induced survival in both rat and chick primary cultures of dissociated dorsal root ganglia (DRG) and on neurite outgrowth of chick DRG explants. Unlike K-252b, which at micromolar concentrations inhibits the survival response of NT-3 in dissociated rat DRG, L-753,000 continued to potentiate the actions of NT-3 up to a concentration of 10 microM. Furthermore, the compound, unlike K-252b, did not inhibit an unrelated protein kinase, protein kinase C, at concentrations up to 10 microM. Because L-753, 000 selectively potentiates the NT-3-induced stimulation of TrkA without inhibiting Trks and other protein kinases, it represents a novel class of selective modifiers of neurotrophin actions.

Analysis of Variance↗
PubMed1999

Does ribosomal DNA get out of the micronuclear chromosome in Paramecium tetraurelia by means of a rolling circle?

The macronuclear genes coding for rRNA (ribosomal DNA [rDNA]) of Paramecium tetraurelia, stock 51, are arranged in polymers consisting of units made up of a transcribed coding region and a nontranscribed spacer region. The whole macronuclear polymer ends with a portion of the spacer on either end followed by a telomere. Six kinds of macronuclear units, or genes, were mapped. Spacers were different, and transcribed regions were the same. These genes are found in markedly different numbers in the macronucleus. The most common gene shows two regions in the spacer where a sequence is followed by a direct repeat. The next most common gene is similar but shows a deletion plus a number of base pair substitutions. Although most cosmid clones contain only a single kind of gene, many contain more than one. These are thought to be produced by somatic crossing over. The four micronuclear genes that have been isolated consist of a single central transcribed region and portions of the spacer on either end. Sequencing indicates that the two ends of the molecule are partially redundant. While the spacer region at the right end of the macronuclear polymer is derived from the micronuclear spacer on the right, the spacer at the left end of the macronuclear polymer is derived from regions of the micronuclear spacer on both the right and the left. To account for this situation, a rolling-circle model for generation of the macronuclear rDNA from the micronuclear DNA is proposed.

Animals↗
PubMed1999

Neuropsychological functioning and MRI signal hyperintensities in geriatric depression.

OBJECTIVE: The purpose of this study was to examine the relationship between signal hyperintensities--a probable marker of underlying pathology--on T2-weighted magnetic resonance brain scans and neuropsychological test findings in elderly depressed and normal subjects. METHOD: Elderly subjects with a DSM-III-R diagnosis of major depression (N=41) and normal elderly comparison subjects (N=38) participated in a magnetic resonance imaging study (1.0-T) of signal hyperintensities in periventricular, deep white matter, and subcortical gray matter. Hard copies of scans were rated in random order by research psychiatrists blind to diagnosis; the modified Fazekas hyperintensity rating scale was used. Cognitive performance was independently assessed with a comprehensive neuropsychological battery. Clinical and demographic differences between groups were assessed by t tests and chi-square analysis. Relationships between neuropsychological performance and diagnosis and hyperintensities and their interaction were analyzed by using analysis of covariance, with adjustment for age and education. RESULTS: Elderly depressed subjects manifested poorer cognitive performance on several tests than normal comparison subjects. A significant interaction between hyperintensity location/severity and presence/absence of depression on cognitive performance was found: depressed patients with moderate-to-severe deep white matter hyperintensities demonstrated worse performance on general and delayed recall memory indices, executive functioning and language testing than depressed patients without such lesions and normal elderly subjects with or without deep white matter changes. CONCLUSIONS: Findings validate cognitive performance decrements in geriatric depression and suggest possible neuroanatomic vulnerabilities to developing particular neuropsychological dysfunction in depressed subjects.

Aged↗
PubMed1999

Assessment of suicide risk 24 hours after psychiatric hospital admission.

Of 69 patients admitted to a hospital because of suicide risk, 30 (44 percent) were completely free of suicidal ideation 24 hours after admission. Scores on the Scale for Suicide Ideation at the time of admission distinguished patients who continued to have suicidal ideation 24 hours later (the sustained-ideation group) from those who did not (the transient-ideation group). Patients in the transient group were more likely than those in the sustained group to have made a suicide attempt during the week before admission. At admission patients in the sustained group were more likely to have psychotic symptoms and to report a family history of psychiatric illness.

Adult↗
PubMed1999

Generalized periodontal involvement in a young patient with systemic lupus erythematosus.

Inflammation is considered to be a leading cause of morbidity in systemic lupus erythematosus (SLE), yet inflammatory periodontal involvement is rarely encountered. A young lady suffering from active SLE accompanied by severe periodontal loss, manifested by gingival recession of all her teeth, was referred to our clinic for treatment. The association between periodontal involvement and connective tissue diseases is unclear, and the literature dealing with periodontal involvement in patients suffering from Sjogren's syndrome and rheumatoid arthritis is comprised of studies showing both normal and pathological periodontal status. We discuss the possible underlying mechanisms.

Adolescent↗
PubMed1999

Reversible pancreatitis, hepatitis, and peripheral polyneuropathy associated with parenteral gold therapy.

A 63-year-old man with seronegative rheumatoid arthritis developed acute pancreatitis, severe hepatitis, and sensorimotor polyneuropathy after receiving 150 mg of intramuscular aurothioglucose (gold). Positive lymphocyte transformation test to gold indicated a cell mediated hypersensitivity to the drug, while multiple investigations ruled out other underlying causes for his illness. After cessation of gold therapy a complete recovery occurred.

Acute Disease↗
PubMed1998

Effects of clozapine on auditory event-related potentials in schizophrenia.

BACKGROUND: Schizophrenia is associated with cognitive deficits that are an intrinsic component of the disorder. Clozapine is an atypical antipsychotic that is superior to typical agents in the treatment of positive symptoms. The degree to which clozapine ameliorates cognitive deficits, however, is still controversial. Mismatch negativity (MMN), N200 (N2), and P300 (P3) are cognitive event-related potentials (ERPs) that index preattentive (MMN) and attention-dependent information processing (N2, P3) and provide a measure of cognitive deficits associated with schizophrenia. In schizophrenic patients deficient generation of MMN, N2, and P3 has been observed, suggesting impairments of discrete stages of information processing. METHODS: This study investigates the effects of clozapine treatment on MMN, N2, and P3 generation. Patients were recruited from a haloperidol-controlled, double-blind treatment study of clozapine in chronic schizophrenia. ERPs were obtained at the beginning of the study and after 9 weeks (4 patients) and 16 weeks (13 patients) of treatment. RESULTS: Clozapine treatment was associated with a significant increase of P3 amplitude, which was not observed in the haloperidol group; however, clozapine treatment did not affect deficits in MMN and N2. CONCLUSIONS: These findings suggest that clozapine--in contrast to conventional antipsychotics--improves electrophysiological measures of attention-dependent information processing, but does not ameliorate preattentive deficits.

Adult↗
PubMed1998

Nocturnal polysomnography in obsessive-compulsive disorder.

To determine if sleep abnormalities occur in obsessive-compulsive disorder (OCD), 2 nights of sleep electroencephalographic (EEG) recordings were obtained from 13 medication-free outpatients with OCD and 13 age- and sex-matched normal volunteers. Patients were awake more on night 2 than on night 1, whereas control subjects had less time awake on night 1; no other differences between groups were found on sleep latency, sleep time, minutes of movement, sleep efficiency, rapid eye movement (REM) latency or amount of stage 1, 2, 3, or 4 or REM sleep. Within the patient group, total scores on the Yale-Brown Obsessive-Compulsive Scale were negatively correlated with total sleep time (r = -0.51, P = 0.07), sleep efficiency (r = -0.51, P= 0.07), and duration of stage 1 + 2 sleep (r = - 0.49, P = 0.09) but not with REM time (r = - 0.05, P = 0.87) or latency (r = -0.26, P = 0.39). Previous sleep studies in OCD have had divergent results, especially regarding REM latency; our results suggest that many OCD patients have essentially normal sleep EEG findings.

Adult↗
PubMed1998

HIV incidence in Ethiopian immigrants to Israel.

The HIV incidence in recent adult Ethiopian immigrants to Israel is estimated through the use of snapshot estimators based on percentage of CD4 progression with time since infection, whereas the preimmigration incidence experienced by this population is estimated using an epidemic model applied to HIV prevalence data obtained from immigrants on arrival in Israel. The snapshot estimators place incidence in adult Ethiopian immigrants in Israel between 3 and 11 infections/1000 uninfected persons/year around May 1995. In contrast, the epidemic model suggests that the incidence experienced by this population before immigration was between 12 and 22 infections/1000 uninfected persons/year. Although the drop in incidence postimmigration is good news, in the aggregate, we estimate that between 50 and 190 new infections have occurred annually in adult Ethiopians who have immigrated to Israel.

Adolescent↗
PubMed1998

Diminished expression of CD40 ligand may contribute to the defective humoral immunity in patients with MHC class II deficiency.

Major histocompatibility complex (MHC) class II deficiency (bare lymphocyte syndrome, BLS) is a rare primary immunodeficiency classified as a subgroup of severe combined immunodeficiency. We studied T and B lymphocyte function by examining the CD40 ligand/CD40 system in three BLS patients from two unrelated families. CD40 ligand expression by maximally activated BLS T cells was diminished. This abnormality may represent immunological naïveté rather than a general T cell defect, since expression of activation marker CD69 and proliferative responses to PHA or anti-CD3 were normal, and BLS T cells primed and restimulated in vitro expressed normal amounts of CD40 ligand. BLS B cells proliferated and produced IgE if stimulated with anti-CD40 or soluble CD40 ligand and IL-4. Activation of BLS B cells with soluble CD40 ligand and IL-4 induced normal expression of activation markers, although MHC class II expression remained absent. Depressed antibody titers, lack of amplification and failure to undergo isotype switching in response to immunization with bacteriophage phi x 174 demonstrated defective T cell help. We conclude that BLS B cells are functionally normal if appropriately stimulated, and that the defective humoral immunity observed may be related to diminished expression of CD40 ligand on BLS T cells.

Antibodies, Viral↗
PubMed1998

Psychological factors in the prediction of Lyme disease course.

OBJECTIVE: To determine whether history of severe, long-term, premorbid, psychological stress is associated with increased incidence of chronic physical symptoms in presumed Lyme disease patients. METHODS: Fifty-seven patients presenting at Lyme Disease Clinic of Long Island Jewish-Hillside Medical Center were studied for presenting symptoms, presence or absence of Lyme disease, and past history of psychological trauma. They were restudied 1 to 1.5 years later for presence or absence of physical symptoms. Statistical analyses compared symptom course for patients with and without Lyme disease, antibiotic and nonantibiotic treatments, and past history of psychological trauma. RESULTS: There was correlation between history of past traumatic psychological events and chronicity of physical symptoms whether or not the patient had presumed Lyme disease or had received antibiotic treatment. CONCLUSION: Traumatic psychological experiences predating onset of Lyme disease symptoms may play an important etiologic role in the chronicity of these symptoms.

Adult↗