Platelet monoamine oxidase activity and schizophrenia--a myth that refuses to die?

Platelet monoamine oxidase (MAO) activity was determined using kynuramine as a substrate in a group of schizophrenic patients (n = 107), a group of healthy individuals (n = 100), and a group of psychiatric patients who were neither schizophrenics nor alcoholics (n = 110). No significant difference emerged between the schizophrenics and the other two groups, while a significant reduction in platelet MAO activity in a group of alcoholics (n = 60) was confirmed. Breaking down the schizophrenic group according to course of illness, phenomenology (paranoid-hallucinatory or not) and drug use did not lead to a significant deviation in platelet MAO activity in any of these subgroups.

Effect of sucralfate on the absorption and pharmacokinetics of chlorpropamide.

This study compared the pharmacokinetics of chlorpropamide (C) when administered alone, or in combination with sucralfate (S) to evaluate whether a drug-drug interaction exists between these two agents in vivo. A two-way, randomized, cross-over study was performed in 12 healthy male volunteers who received 250 mg C alone or were pretreated with S qid for two days and then received a single 250-mg dose of C with S on day 3 and continued to take sucralfate throughout the day while serial blood samples were drawn. High-performance liquid chromatography determination of plasma concentrations found there to be no statistically significant differences in maximum concentration, time to maximum concentration, elimination rate constant, or area under the concentration-time curve from 0 to 96 hours.

[Combined therapy with high-dosage cisplatin and radiation in advanced ENT tumors (a phase-II study)].

The most promising method to obtain at least a palliative effect in advanced ORL tumors seems to be a combination of chemotherapy and radiotherapy. We made an attempt to reach a higher remission rate (n = 28) by means of an extraordinary high dose of cis-platinum and the usual maximum radiation dose of 60 Gy: The method had to be abandoned because the rates of success (CR and PR) decreased from 79% to 46% in eight months, the side effects, however, were beyond a tolerable degree. We are of the opinion that the same results can be obtained by less radical methods, too.

Guanine nucleotides stimulate NADPH oxidase in membranes of human neutrophils.

In the chain of events by which chemotactic peptides stimulate NADPH oxidase-catalyzed superoxide formation in human neutrophils, the involvements of a pertussis toxin-sensitive guanine nucleotide-binding protein (N-protein), mobilization of intracellular calcium and protein kinase C stimulation have been proposed. Superoxide formation was studied in membranes from human neutrophils; NADPH oxidase was stimulated by arachidonic acid in the presence of neutrophil cytosol. Fluoride and stable GTP analogues, such as GTP gamma S and GppNHp, which all activate N-proteins, enhanced NADPH oxidase activity up to 4-fold.

Heparin kinetics during hemodialysis: variation in sensitivity, distribution volume, and dosage.

A method to assess heparin kinetics and individualize dosages was examined in 27 patients during chronic hemodialysis. Pretreatment heparin sensitivities were determined to establish the relationship between heparin concentration and activated clotting times (ACTs). Distribution volume was calculated by dividing the heparin loading dose by the 5-min heparin concentration.

Pharmacogeriatrics.

The elderly comprise one of the fastest growing populations in the United States. By the year 2020, an estimated 45 million will be classified as elderly. Aging is a highly variable process as declines occur in physiologic functions.

Locally acting growth factors for vascular smooth muscle cells: endogenous synthesis and release from platelets.

Release of platelet-derived growth factor (PDGF) from platelets has been postulated to stimulate at least some of the cell proliferation seen at sites of tissue damage, both beneficially (wound healing) and perniciously (during formation of atherosclerotic lesions). Two other growth factors have been localized to the platelet: epidermal growth factor and transforming growth factor. These factors may function synergistically with PDGF in promoting smooth muscle cell proliferation in the injured vessel wall.

Monoclonal antibodies to bovine alpha-crystallin.

Monoclonal antibodies to bovine alpha-crystallin have been produced using hybridoma technology. Five selected hybridoma clones were maintained as ascites tumours in mice and gram quantities of the antibodies were purified from the ascites fluids by affinity chromatography on alpha m-crystallin covalently bound to Sepharose CL-2B. Preliminary characterization studies suggest that the antibodies are pure and monospecific.

Developmentally regulated production of platelet-derived growth factor-like molecules.

Platelet-derived growth factor (PDGF) is thought to mediate the proliferation of smooth muscle cells in injured arteries, and may be involved in the pathogenesis of atherosclerosis. PDGF-like molecules from non-platelet sources may also play a role in the regulation of cell activity in other circumstances. Transformation of cells by a wide range of oncongenic agents appears to activate a cellular gene encoding a PDGF-like molecule, possibly accounting for the ability of transformed cells to grow without addition of exogenous mitogens.

Nicotinamide methylation. Tissue distribution, developmental and neoplastic changes.

The distribution of cytosolic activity of nicotinamide:S-adenosylmethionine methyltransferase (nicotinamide methylase, EC 2.1.1.

Heparin-induced thrombocytopenia in patients with cerebrovascular ischemic disease.

We studied 137 patients who were treated with heparin for cerebral infarction (73), partially reversible ischemic neurologic deficit (22), or transient ischemic attack (42). Platelet counts were performed before therapy, twice weekly, and at cessation of therapy. Platelets decreased in 118 patients (86%).

Heparin-associated thrombocytopenia: a prospective evaluation of 211 patients.

Two hundred eleven consecutive patients treated for acute thromboembolic disease were evaluated prospectively for the incidence of thrombocytopenia while receiving heparin treatment. One hundred patients received beef lung heparin and 111 patients received porcine intestinal mucosal heparin. All patients received a minimum of 4 consecutive days of continuous intravenous heparin, and platelet counts were determined prior to, at least twice weekly, and at the cessation of heparin therapy.

Use of anticholinergics in the nursing home: an empirical study and review.

The Medicare Utilization Review Committee conducted a survey to determine the use of drugs with anticholinergic effects in confused elderly nursing home patients. Twenty-nine patients (34.5 percent) were receiving anticholinergic drugs, predominantly from the antidepressant and antipsychotic class.

[Clinical experience with blood vessel ligation in uncontrollable nosebleed].

Between 1978 and 1980 in the ENT clinics of Mannheim 19 patients with severe epistaxis have been treated surgically. Nearly always epistaxis was due to hypertonus or arteriosclerosis. Before ligation of maxillary or ethmoid arteries Bellocq's nasal packing was used.

Application of the peroxidase anti-peroxidase system as an universal reagent for the two-site binding enzyme immunoassay.

An indirect two-site binding enzyme immunoassay (EIA) is described, in which horse-radish peroxidase (HRP) is bound immunologically to anti-HRP IgG in the form of peroxidase anti-peroxidase complexes (PAP-complex). In this EIA both purified HRP and crude HRP had the same sensitivity due to the selective reaction of the monospecific anti-HRP IgG with the highly active HRP isoenzymes in both preparations. To obtain similar results the amount of crude HRP needed is 18 times higher than that of purified HRP.

Synaptic vesicles from hog brain-their isolation and the coupling between synthesis and uptake of ?-aminobutyrate by glutamate decarboxylase.

Purified synaptic vesicles were isolated from hog cerebral cortex by a rapid procedure consisting of homogenization of cerebral cortex slices in iso-osmotic sucrose, differential centrifugation and sucrose density-gradient centrifugation. The purity of the vesicles was evaluated both biochemically and morphologically. The vesicles contained high amounts of ?-aminobutyrate (GABA) and acetylcholine at specific concentrations of 390 nmol/mg protein and 7.

Benzodiazepine utilization in a family medicine residency program.

A study was conducted to determine the benzodiazepine-prescribing habits of residents in a family medicine training program. Data were collected from medication profiles of all patients seen at the Family Practice Center from July 1975 to February 1981. Additional demographic data (ie, age, sex) were collected on patients prescribed benzodiazepines, and prescribing behavior was validated according to the Psychopharmacological Screening Criteria Development Project.