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Biomedical subjects

S Pollack

Publications and source records attributed to S Pollack.

At least 55 records · Page 3Linked to original sources
PubMed1992

Marked reduction in indexes of dopamine metabolism among patients with depression who attempt suicide.

Cerebrospinal fluid studies have reported that low concentrations of the dopamine metabolite homovanillic acid are associated with suicidal behavior in depression. Although only a small proportion of homovanillic acid in the urine derives from the brain, we decided to examine 24-hour urinary outputs of homovanillic acid in relation to suicidal behavior in depression. Patients with depression who had attempted suicide had significantly smaller urinary outputs of homovanillic acid, dihydroxyphenylacetic acid, and total body output of dopamine (sum dopamine) than did patients with depression who had not attempted suicide. Patients with depression who reattempted suicide during 5-year follow-up had significantly smaller urinary outputs of homovanillic acid and sum dopamine than did patients who did not reattempt suicide, patients who never attempted suicide, and normal control subjects, and had significantly smaller outputs of dihydroxyphenylacetic acid than patients who never attempted suicide or control subjects. These data suggest that urinary outputs of homovanillic acid may be peripheral correlates of suicidality in depression. These data add to data on the low levels of homovanillic acid in cerebrospinal fluid in suggesting that diminished dopaminergic neurotransmission may play a part in suicidal behavior in depression.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

Difficulties and rewards in family care of the depressed older adult.

Spouse and adult child caregivers of older adults with major depressive disorder (N = 150) were asked what was most difficult and most rewarding about providing assistance to their relatives. Content analysis of their responses revealed seven areas of difficulty and three areas of reward. Difficulties and rewards were selectively associated with the caregiver's identity, patient clinical characteristics, and caregiver emotional adjustment. Caregiver perceived family difficulties and emotional difficulties were associated with the course of patient psychiatric illness over 1 year.

Aged↗
PubMed1992

Decreased interleukin 1 activity released from circulating monocytes of patients with familial Mediterranean fever during in vitro stimulation by lipopolysaccharide.

Familial Mediterranean fever (FMF) is an inherited disorder of unknown etiology characterized by recurrent episodes of serous membrane inflammation. Interleukin 1 (IL-1) is a mediator of inflammatory processes. We hypothesized that IL-1 may play a role in acute attacks of FMF. Thus we tested IL-1 production by monocytes derived from patients with FMF. Nine patients were tested during acute attacks and 9 were asymptomatic when tested. Monocytes derived from peripheral blood of patients and controls were stimulated with lipopolysaccharide (LPS) and IL-1 activity in the supernatant was tested using a T helper cell line (D10-4G.1). IL-1 secretion during acute attacks was decreased whereas IL-1 production in asymptomatic patients was comparable to healthy controls. Followup of symptomatic patients during the recovery period revealed normalization of IL-1 secretion. Addition of indomethacin (prostaglandin E2 inhibitor) to LPS stimulated monocytes did not change IL-1 activity in patients or healthy controls. We conclude that in vitro IL-1 activity in patients with FMF is associated with the intensity of the inflammatory process.

Adolescent↗
PubMed1991

Evidence for involvement of glycoprotein-CD45 phosphatase in reversing glycoprotein-CD3-induced microtubule-associated protein-2 kinase activity in Jurkat T-cells.

Ligation of CD3/TCR on T-cells induces transient activation of lymphoid MAP-2 kinase (MAP-2K), a 43 kDa serine kinase which itself is a substrate of an unidentified tyrosine kinase (pp43). The reversibility of the MAP-2K response agrees with removal of tyrosine phosphates from pp43. Since both activity as well as tyrosine phosphorylation of MAP-2K could be prolonged by Na3VO4, a phosphotyrosine phosphatase inhibitor, we studied the effect of the common CD45 isoform, which is a member of the CD45 phosphatase family, on MAP-2K activity in vivo and in vitro. We demonstrate the ability of purified CD45 phosphatase to remove tyrosine phosphates from partially purified lymphoid MAP-2K. Utilizing the approach of heterologous receptor aggregation, we also showed that CD45 could inhibit the induction of MAP-2K activity in intact Jurkat cells during CD3 or CD3 + CD4 stimulation. We therefore suggest that this phosphatase may control the activity of lymphoid MAP-2K in vivo.

Antigens, CD↗
PubMed1991

High dose intravenous gamma-globulin in intractable epilepsy of childhood.

Eight children aged between 1.3 and 13 years suffering from epilepsy refractory to conventional anticonvulsive therapy were treated with high dose intravenous gamma globulin (200 mg/kg, 3 times per week, repeated after 3 weeks). Immunological studies after therapy showed normal results. In four children, clinical and EEG findings markedly improved. In one other case a partial response was noted. No improvement was observed in the remaining three cases. We confirm that although the mechanism is still obscure, high doses of i.v. gammaglobulin may have a beneficial effect in a significant number of children with intractable epilepsy.

Adolescent↗
PubMed1991

Responsiveness of a human parotid epithelial cell line (HSY) to autonomic stimulation: muscarinic control of K+ transport.

Salivary electrolyte secretion is under the control of the autonomic nervous system. In this paper we report that HSY, an epithelial cell line derived from the acinar-intercalated duct region of the human parotid gland, responds to muscarinic-cholinergic (generation of Ca2+ signal) and beta-adrenergic (generation of cAMP signal), but not to alpha-adrenergic (lack of Ca2+ signal), receptor stimulation. The muscarinic response was studied in detail. Carbachol (10(-4) M, muscarinic agonist) or A23187 (5 microM, calcium ionophore) stimulation of HSY cells increases both 86Rb (K+) influx and efflux, resulting in no change in net equilibrium 86Rb content. Atropine (10(-5) M, muscarinic antagonist) blocks both the carbachol-generated Ca2+ signal and carbachol-stimulated 86Rb fluxes, but has no effect on either the A23187-generated Ca2+ signal or A23187-stimulated 86Rb fluxes. Carbachol- and A23187-stimulated 86Rb fluxes are substantially inhibited by two K+ channel blockers, quinine (0.3 mM) and scorpion venom containing charybdotoxin (33 micrograms/ml). The inhibition of these stimulated fluxes by another K+ channel blocker, tetraethylammonium chloride (5 mM), is less pronounced. Protein kinase C (PKC) seems to be involved in the regulation of the 86Rb fluxes as 10(-7) M PMA (phorbol ester, phorbol-12-myristate-13-acetate) substantially inhibits the muscarinic-stimulated 86Rb efflux and influx. Because this concentration of PMA totally inhibits the carbachol-generated Ca2+ signal and only 80% of the muscarinic-stimulated 86Rb influx, it seems that a portion of the carbachol-stimulated 86Rb flux (i.e. that portion not inhibited by PMA) might occur independently of the Ca2+ signal. PMA fails to inhibit the A23187-stimulated 86Rb fluxes, however, suggesting that PKC regulates Ca(2+)-sensitive K+ channel activity by regulating the Ca2+ signal, and not steps distal to this event. 4-alpha-Phorbol-12,13-didecanoate, a phorbol ester which fails to activate PKC, fails to inhibit either the carbachol-stimulated increase in intracellular free Ca2+, or carbachol-stimulated 86Rb fluxes.

Adenocarcinoma↗
PubMed1991

Classic Kaposi's sarcoma: T-lymphocyte subsets, T4/T8 ratio, and NK cell activity.

Lymphocyte function as expressed by T-lymphocyte subsets and natural killer cell activity was evaluated in a group of Israeli patients with classic Kaposi's sarcoma. T-cell subsets were examined in 28 patients, 14 with lesions limited to the lower extremities and 14 with diffuse cutaneous or systemic involvement. CD4 and CD8 lymphocytes and CD4/CD8 ratio were in the normal range in all patients, and mean values of the entire group were similar to a control group. However, CD8 was in the upper limits of the normal range in some patients with diffuse cutaneous or systemic involvement. This factor led to a significantly decreased CD4/CD8 ratio in that group as compared with the group of patients with the disease limited to the lower extremities. Mean values of natural killer cell activity in three effector/target cell ratios were significantly decreased in 13 of the patients with Kaposi's sarcoma with lesions limited to the lower extremities and in all of the patients with normal T-cell subsets and CD4/CD8 ratios.

Adult↗
PubMed1991

Influence of the mobile phase on salmon calcitonin analysis by reversed-phase liquid chromatography.

The retention properties of calcitonins on a reversed-phase column are examined using salmon calcitonin as the model compound. The effect of the concentration of organic modifier, buffer strength, pH of the mobile phase, and ion-pair reagent are studied. In the absence of an ionic modifier in the eluent the calcitonin peak shapes are not symmetrical. The addition of 0.1% trifluoroacetic acid (TFA), however, results in good peak characteristics without the need to add nonvolatile salts. The retention of the calcitonins was found to be very sensitive to the concentration of the organic modifier (acetonitrile) present in the mobile phase. A change of pH between 2 and 5 has only a slight effect of the k' of salmon calcitonin, but the k' increases significantly at higher pH values. The addition of a phosphate buffer to the mobile phase and an increase in the buffer concentration (0-0.2 M) causes a decrease in the retention of salmon calcitonin. Evidence shows that reproducible, quantitatively measurable data can be obtained using reversed-phase chromatography if the ion-pairing reagent and organic modifier concentrations are carefully controlled. The system also shows a good selectivity for the calcitonin series. Therefore, both highly selective methods (qualitative) as well as quantitative methods for analytical, pharmaceutical, and manufacturing use can be developed by adjusting the high-performance liquid chromatography (HPLC) conditions as discussed.

Amino Acid Sequence↗
PubMed1991

The comorbidity of borderline personality disorder and other DSM-III-R axis II personality disorders.

OBJECTIVE: This study examines the comorbidity of DSM-III-R borderline personality disorder and the other axis II personality disorders. The extent and direction of overlap provides a measure of the clarity of its diagnostic boundaries and descriptive validity. METHOD: In 110 outpatients without concurrent major axis I conditions, axis II diagnoses were assessed in semistructured format and all DSM-III-R personality disorder criteria were rated. Multiple diagnoses were recorded. RESULTS: Twenty-two patients (20%) met criteria for borderline personality disorder; 18 (82%) had at least one additional personality disorder diagnosis. Using measures of frequencies and intercorrelation coefficients, the authors found that overlap was extensive and not confined to any one of the three designated axis II clusters. Factor analysis revealed 1) a group containing borderline personality disorder with paranoid, histrionic, narcissistic, antisocial, and passive-aggressive personality disorders and 2) another grouping of schizoid, schizotypal, avoidant, obsessive-compulsive, and self-defeating personality disorders. CONCLUSIONS: Borderline personality disorder appears to constitute a broad, heterogeneous category with unclear boundaries that embraces a general personality disorder concept. Both further refinement of the borderline personality disorder construct and investigation into alternative models to the DSM-III-R axis II classification system are suggested.

Adolescent↗
PubMed1991

Psychological comorbidity and length of stay in the general hospital.

OBJECTIVE: As general hospitals search for ways to cut costs without sacrificing efficiency, particular attention has been focused on factors that may prolong hospital stay. The results of prior studies that have reported an association between psychological and psychiatric comorbidity and longer hospital stays have been subject to different interpretations because of methodological design flaws. The current paper reports on a study of psychological comorbidity and length of stay that has been designed to avoid the methodological problems of earlier investigations. METHOD: The study was performed at a 429-bed tertiary-care, university-affiliated, voluntary, teaching hospital. During hospital days 3 to 5, patients were tested as available with the Mini-Mental State examination, the Zung Depression Inventory, and the SCL-90 and were rated for physical impairment with the Karnofsky Performance Status Scale. Statistical analyses were performed for correlations between length of stay and test scores, rating scales, and demographic and discharge data from the chart. RESULTS: Of 424 patients approached, 321 (76%) agreed to participate and 278 (65.6%) completed the test battery. Depression, anxiety, and organicity, measured by psychological tests, were significantly correlated with longer hospital stay. These correlations remained significant after the authors controlled for degree of physical impairment, emergency versus elective admission, and medical versus surgical service, which were themselves correlated with longer hospital stay. DISCUSSION: This study confirms a significant correlation between psychological comorbidity and length of stay after correcting for the methodological pitfalls found in earlier studies. The clinical, research, economic, and policy implications of these findings are discussed.

Adolescent↗
PubMed1991

The long term benefits of a comprehensive teenage pregnancy program.

A comprehensive program was founded in 1982 to provide adolescents with prenatal and family planning care. The program's impact through its first five years of operation on medical aspects of pregnancy course and fetal outcome will be the subject of a separate report. This study examines subsequent maternal and infant health of the patients attending the program compared to a control group. Four hundred ninety-eight adolescents and their newborns attending the program's mother-baby family planning clinic from 1982 to 1989 (subject group) were compared to ninety-one adolescents and their newborns receiving postpartum family planning and pediatrics clinics from 1980 through 1989 (control group). Seventy-five percent of the subject group regularly attended mother-baby clinic, compared to 18% of the control group attending family planning and pediatric clinics (P less than or equal to .0001). The subject group experienced less maternal and infant morbidity, greater school attendance, graduation, employment, and contraceptive use than the control group (P less than or equal to .0001). Many parameters improved with each program year indicating continued wide acceptance of our program by area adolescents.

Adolescent↗
PubMed1991

The effects of clozapine on tardive dyskinesia.

This article reviews eight published studies that describe clozapine's effects on TD and examines the outcome of 30 patients with TD treated with clozapine for up to 36 months. These data indicate that TD response to clozapine is variable but that approximately 43% of cases, particularly those with dystonic features, improved after clozapine treatment. Methodological limitations of the studies described, however, preclude definitive conclusions, which must await appropriately controlled trials.

Adult↗
PubMed1990

Two types of receptors for iron on mitochondria.

ATP, the major ligand for Fe in the reticulocyte's low-Mr chelatable pool, transfers Fe to a mitochondrial receptor from which the Fe is incorporated into haem. However, the utilization of Fe bound to this receptor for haem synthesis is slow in comparison with that bound to a second receptor that does not accept Fe from ATP, but does accept it from AMP. The major pathway by which Fe is delivered for haem synthesis may be through hydrolysis of cytosolic ATP-Fe to AMP-Fe.

Adenosine Monophosphate↗