Efficacy of pimozide augmentation for clozapine partial responders with schizophrenia.

Introduction: A substantial number of patients with treatment-resistant schizophrenia respond only partially to clozapine. Therefore, it has been common practice to use augmentation strategies to maximize clozapine's effect. But the efficacy of this strategy remains poorly established.

Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Delta-9-tetrahydrocannabinol in humans.

Introduction: Cannabinoids produce a spectrum of effects in humans including euphoria, cognitive impairments, psychotomimetic effects, and perceptual alterations. The extent to which dopaminergic systems contribute to the effects of Delta-9-tetrahydrocannabinol (Delta-9-THC) remains unclear. This study evaluated whether pretreatment with a dopamine receptor antagonist altered the effects of Delta-9-THC in humans.

Blunted psychotomimetic and amnestic effects of delta-9-tetrahydrocannabinol in frequent users of cannabis.

Cannabis is one of the most widely used illicit substances and there is growing interest in the association between cannabis use and psychosis. Delta-9-Tetrahydrocannabinol (Delta-9-THC) the principal active ingredient of cannabis has been shown to induce psychotomimetic and amnestic effects in healthy individuals. Whether people who frequently use cannabis are either protected from or are tolerant to these effects of Delta-9-THC has not been established.

Enhanced sensitivity to the euphoric effects of alcohol in schizophrenia.

The purpose of this study was to determine whether schizophrenia was associated with alterations in alcohol response that might explain the elevated risk for AUDs in this population. In a randomized, double-blind, placebo-controlled, counter-balanced 3 test day laboratory study, the effects of alcohol were compared in 23 subjects with schizophrenia (without any previous alcohol use disorder (AUD) but with some alcohol exposure) and in 14 healthy subjects matched for age, gender, education, and lifetime exposure to alcohol. Standard alcohol drinks in a scheduled design were administered to produce blood alcohol levels of 0, 0.

Relationships among plasma dehydroepiandrosterone sulfate and cortisol levels, symptoms of dissociation, and objective performance in humans exposed to acute stress.

Context: Recently, a growing body of research has provided evidence that dehydroepiandrosterone sulfate (DHEA-S) is involved in an organism's response to stress and that it may provide beneficial behavioral and neurotrophic effects.

Objective: To investigate plasma DHEA-S and cortisol levels, psychological symptoms of dissociation, and military performance.

Design: Prospective study.

Leptin and the perioperative neuroendocrinological stress response.

The human response to surgical stress is characterized by massive release of neuroendocrine hormones, provoking catabolism, thermogenesis, and hyperglycemia. Considering the possible adverse outcomes of excessive stress hormones, understanding various components of the stress response may improve management of postoperative morbidity. Leptin, initially described as an adipocyte-derived signaling factor, may also play an important role in regulating the hypothalamo-pituitary-adrenocortical axis.

Phosphatidylinositol 3-kinase association with the osteoclast cytoskeleton, and its involvement in osteoclast attachment and spreading.

Osteoclast activation involves attachment to the mineralized bone matrix and reorganization of the cytoskeleton, leading to polarization of the cell. Signaling molecules, PI3-kinase, rho A, and pp60c-src, were shown to be essential for osteoclastic bone resorption. In this study we have focused on the involvement of these signaling molecules in the early event of osteoclast activation: attachment, spreading, and organization of the cytoskeleton.

Alendronate inhibition of protein-tyrosine-phosphatase-meg1.

Alendronate (4-amino-1-hydroxybutylidene-1,1-bisphosphonate) is a potent bisphosphonate that inhibits osteoclastic bone resorption and has proven effective for the treatment of osteoporosis. Its molecular mechanism of action, however, has not been defined precisely. Here we report that alendronate is a potent inhibitor of the protein-tyrosine-phosphatase-meg1 (PTPmeg1).

The subcellular distribution of eukaryotic translation initiation factor, eIF-5A, in cultured cells.

To gain insight into the role of the eukaryotic translation initiation factor, eIF-5A, we investigated the subcellular distribution of this protein in several cultured cell types and at different stages of the cell cycle using a highly potent monospecific polyclonal antibody to eIF-5A. Studies using indirect immunofluorescence and confocal microscopy in conjunction with subcellular fractionation demonstrate that eIF-5A is primarily localized in the cytoplasm of cells. This cytoplasmic location of eIF-5A is not significantly altered in different stages of the cell cycle and the subcellular distribution pattern of eIF-5A is not changed by viral oncogene transformation.

Acid extrusion is induced by osteoclast attachment to bone. Inhibition by alendronate and calcitonin.

Acid extrusion is essential for osteoclast (OC) activity. We examined Na+ and HCO3(-)-independent H+ extrusion in rat- and mouse OCs by measuring intracellular pH (pHi) changes, with the pHi indicator BCECF (biscarboxyethyl-5-(6) carboxyfluorescein) after H+ loading with an ammonium pulse. 90% of OCs attached to glass do not possess HCO3- and Na(+)-independent H(+)-extrusion (rate of pHi recovery = 0.

Soluble alpha v beta 3-integrin ligands raise [Ca2+]i in rat osteoclasts and mouse-derived osteoclast-like cells.

We evaluated the possible involvement of intracellular Ca2+ concentration ([Ca2+]i) changes in the action of alpha v beta 3-ligands, known to regulate osteoclast function. Rat osteoclasts or mouse osteoclast-like cells, as examined by microfluorimetry and fura 2, showed a transient [Ca2+]i increase when perfused with (all 0.1 microM) vitronectin, osteopontin, polypeptide echistatin, fibronectin, and Arg-Gly-Asp-Asp and Arg-Gly-Asp-Ser peptides (10(-4) M) but not with laminin, collagen I, collagen IV, or [Ala24]echistatin, in which Ala was substituted for Arg in the Arg-Gly-Asp complex.

H+ extrusion by an apical vacuolar-type H(+)-ATPase in rat renal proximal tubules.

The activity of Na+/H(+)-exchange and H(+)-ATPase was measured in the absence of CO2/HCO3 by microfluorometry at the single cell level in rat proximal tubules (superficial S1/S2 segments) loaded with BCECF [2'7'-bis(carboxyethyl)5-6-carboxyfluorescein- acetoxymethylester]. Intracellular pH (pHi) was lowered by a NH4Cl-prepulse technique. In the absence of Na+ in the superfusion solutions, pHi recovered from the acid load by a mechanism inhibited by 0.

Relation of ATPases in rat renal brush-border membranes to ATP-driven H+ secretion.

In the presence of inhibitors for mitochondrial H+-ATPase, (Na+ + K+)- and Ca2+-ATPases, and alkaline phosphatase, sealed brush-border membrane vesicles hydrolyse externally added ATP demonstrating the existence of ATPases at the outside of the membrane ("ecto-ATPases"). These ATPases accept several nucleotides, are stimulated by Ca2+ and Mg2+, and are inhibited by N.N'-dicyclohexylcarbodiimide (DCCD), but not by N-ethylmaleimide (NEM).

Phosphate transport in brush-border membranes from control and rachitic pig kidney and small intestine.

1. Na-Pi co-transport was analysed using renal cortical and small intestinal brush-border membrane vesicles which were isolated from control (normal, heterozygotes) and rachitic piglets (homozygotes). 2.

Isolation of renal brush-border membrane vesicles by a low-speed centrifugation; effect of sex hormones on Na+-H+ exchange in rat and mouse kidney.

Na+-H+ exchange in rat and mouse renal brush-border membrane vesicles was studied by fluorescence quenching of the delta pH indicator, acridine orange. Brush-border membrane vesicles were isolated by a modified Mg/EGTA-precipitation method at low speed centrifugation (8000 X g). The enzymatic characteristics of these membrane vesicles were similar to those obtained by the original high-speed centrifugation method (Biber et al.