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S Pollack

Publications and source records attributed to S Pollack.

At least 91 records · Page 5Linked to original sources
PubMed1993

Does clozapine cause tardive dyskinesia?

BACKGROUND: The authors attempted to determine if chronic exposure to clozapine can cause tardive dyskinesia. METHOD: Twenty-eight schizophrenic or schizoaffective patients with no prior history of definite tardive dyskinesia were treated with clozapine for at least 1 year, and their ongoing modified Simpson Dyskinesia Scale ratings were analyzed. These data were then compared with those of another group of similarly diagnosed patients who were treated with a conventional neuroleptic for at least 1 year. RESULTS: Two patients in the clozapine-treated group (both of whom had ratings of questionable tardive dyskinesia at baseline) were later rated by the modified Simpson Dyskinesia Scale as having mild tardive dyskinesia on at least two consecutive ratings 3 months apart. Although there was uncertainty about whether clozapine definitely caused the tardive dyskinesia in those two patients, a survival analysis comparing the clozapine-treated group with the neuroleptic-treated group showed a lower risk of tardive dyskinesia developing in the clozapine-treated group. CONCLUSION: This study was unable to definitively conclude whether clozapine causes tardive dyskinesia. However, if cases do develop, the risk of tardive dyskinesia is likely to be less with clozapine than with typical neuroleptics.

Adult↗
PubMed1993

A complementary role for thallium-201 scintigraphy with mammography in the diagnosis of breast cancer.

Physical examination and mammography are currently the only proven and reliable methods of early detection of breast cancer. Although both procedures are highly sensitive, their limited specificity often requires surgical biopsy in order to differentiate between malignant and benign lesions. The purpose of this prospective study is to investigate the diagnostic specificity of thallium imaging for breast cancer and to determine its efficacy as a complement to mammography. Two groups were studied: Group A: Patients found to have breast abnormalities and scheduled for biopsy or surgery and Group B: Patients who were suspected to have a recurrence of cancer after mastectomies or lumpectomies. In Group A, thallium scans of 32 breasts in 30 patients were performed prior to biopsy or surgery, yielding pathological diagnoses of 31 breasts in 29 patients. Results for Group A included seven true-positive thallium scans, twenty-two true-negative scans, two false-negative scans, and one false-positive scan. In Group B, seven patients were scanned to evaluate subcutaneous nodules for breast cancer following mastectomy or lumpectomy. Results for Group B included five true-positive scans, one true-negative scan, one false-negative scan and no false-positive scans. Thallium breast scanning was shown to have high specificity for cancer (specificity 96% and sensitivity 80%), suggesting that this technique should be evaluated in additional patient studies to determine its role in clinical situations.

Adult↗
PubMed1993

High plasma clozapine levels in tardive dyskinesia.

Studies in the literature that attempt to relate neuroleptic plasma levels to the development of tardive dyskinesia (TD) report inconsistent findings. As part of an open, long-term study, 60 schizophrenic and schizoaffective patients were started gradually on a b.i.d. schedule of the atypical antipsychotic drug clozapine. Blood samples were drawn weekly for 6 weeks and analyzed for a variety of constituents including clozapine plasma levels. Patients with higher levels of TD were found to have significantly higher levels of plasma clozapine and a higher ratio of plasma/dose than those with lower levels of TD. Our data suggests that schizophrenics with TD may have different pharmacokinetics, drug metabolism, and elimination processes than those without TD. Higher typical plasma neuroleptic levels may increase susceptibility to TD development. A second hypothesis implies that it is not the higher mean plasma level of a neuroleptic that is associated with TD but the greater fluctuations of plasma levels over time (i.e., a higher variance). This hypothesis is discussed in the context of our data.

Adult↗
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↗