In vivo functions of the septin and actin cytoskeletons are closely intertwined, yet the mechanisms underlying septin-actin crosstalk have remained poorly understood. Here, we show that the yeast-bud-neck-associated Fes/CIP4 homology Bar-amphiphysin-Rvs (F-BAR) protein suppressor of yeast profilin 1 (Syp1)/FCHo uses its intrinsically disordered region (IDR) to directly bind and bundle filamentous actin (F-actin) and to physically link septins and F-actin. Interestingly, the only other F-BAR protein found at the neck during bud development, Hof1, has related activities and also potently inhibits the bud-neck-associated formin Bnr1.
View Article and Find Full Text PDFIn response to pheromone extend a mating projection. This process depends on the formation of polarized actin cables which direct secretion to the mating tip and translocate the nucleus for karyogamy. Here, we demonstrate that proper mating projection formation requires the formin Bni1, as well as the actin nucleation promoting activities of Bud6, but not the formin Bnr1.
View Article and Find Full Text PDFHow actin filaments are spatially organized and remodeled into diverse higher-order networks in vivo is still not well understood. Here, we report an unexpected F-actin "coalescence" activity driven by cyclase-associated protein (CAP) and enhanced by its interactions with actin-binding protein 1 (Abp1). We directly observe S.
View Article and Find Full Text PDFPolarized morphogenesis is achieved by targeting or inhibiting growth in distinct regions. Rod-shaped fission yeast cells grow exclusively at their ends by restricting exocytosis and secretion to these sites. This growth pattern implies the existence of mechanisms that prevent exocytosis and growth along nongrowing cell sides.
View Article and Find Full Text PDFPolarized growth and cytokinesis are two fundamental cellular processes that exist in virtually all cell types. Mechanisms for asymmetric distribution of materials allow for cells to grow in a polarized manner. This gives rise to a variety of cell shapes seen throughout all cell types.
View Article and Find Full Text PDFProtein kinases direct polarized growth by regulating the cytoskeleton in time and space and could play similar roles in cell division. We found that the Cdc42-activated polarity kinase Pak1 colocalizes with the assembling contractile actomyosin ring (CAR) and remains at the division site during septation. Mutations in pak1 led to defects in CAR assembly and genetic interactions with cytokinesis mutants.
View Article and Find Full Text PDFComplete inundation at the early seedling stage is a common environmental constraint for soybean production throughout the world. As floodwaters subside, submerged seedlings are subsequently exposed to reoxygenation stress in the natural progression of a flood event. Here, we characterized the fundamental acclimation responses to submergence and reoxygenation in soybean at the seedling establishment stage.
View Article and Find Full Text PDFObjective: This study was designed to clarify the nature of the reduced function of the peripheral beta adrenoceptor system observed in panic disorder with agoraphobia. The authors hypothesized that this phenomenon reflected a regulatory and adaptive process.
Methods: Lymphocyte beta adrenoreceptor density and affinity, basal lymphocyte cAMP level, and isoproterenol-stimulated cAMP generation were measured in 27 untreated outpatients with panic disorder with agoraphobia and 24 healthy comparison subjects.
Ann Clin Psychiatry
June 1993
Scores on rating scales measuring symptoms of depression, panic anxiety, state anxiety, trait anxiety, and agoraphobic avoidance were correlated, using multivariate statistics, with total thyroxine- and thyrotropin-releasing hormone concentrations in outpatients with major depression. A significant inverse relationship was demonstrated between agoraphobic avoidance and total thyroxine concentrations in female patients. No other symptom ratings were significantly associated with these thyroid indices.
View Article and Find Full Text PDFHomovanillic acid (HVA), an oxidative metabolite of dopamine, has been shown in a number of studies to reflect severity of symptoms and to predict response to neuroleptic treatment in schizophrenic patients. In several clinical studies, HVA levels have been shown to have a positive relationship with symptom severity and to decline over time upon treatment with antipsychotic agents. The magnitude of this decline appears to be related to the degree of symptom reduction in patients so treated.
View Article and Find Full Text PDFPsychopathology
September 1992
Studies showing interference with color naming threat-related words in patients with anxiety disorders suggest a bias towards processing threatening material in these patients. We assessed the specificity of this finding to anxiety disorders and to threatening stimuli by administering Stroop cards with a variety of types of emotional stimuli to 24 panic disorder patients with no history of major depression, 30 patients with major depression and no history of panic attacks and 25 controls with no history of an axis I disorder. Our findings suggest that the abnormal information processing seen in panic disorder may be characterized by a more general bias towards processing emotional stimuli than previously thought.
View Article and Find Full Text PDFThe number of beta adrenergic binding sites (Bmax) in human lymphocyte membranes has been reported to decrease, remain the same, or increase with age. In order to address this issue, we used two highly specific beta receptor ligands with lymphocytes from healthy aged (range: 51-90 years) and young (19-39 years) subjects in two separate studies. Because depression can reduce Bmax, potential aged subjects were excluded if they had high scores on tests for depression.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
April 1990
1. Normal male subjects were tested with either a multi-trial word list learning test or a spatial analogue prior to administration of either 4 mg. or 10 mg.
View Article and Find Full Text PDFValues of binding maximum (Bmax) and dissociation constant (Kd) of (-)3-[125I]iodocyanopindolol (ICYP) were determined in beta-adrenergic receptors of membranes of peripheral lymphocytes in 32 patients with unipolar depression (DSM-III-R) and 31 normal controls. Results were analyzed by a two-way Analysis of Covariance method. A significant difference was noted for group assignment (patient versus control, p less than 0.
View Article and Find Full Text PDFNeuropsychopharmacology
March 1989
Two groups of normal male volunteers were administered oral haloperidol at two dose levels: 4 mg (n = 12), and 10 mg (n = 9). Subjects were administered the Symbol-Digit Substitution Test (SDST) prior to drug administration (0 hours) and at the following intervals after administration: 1, 3, 4, 6, 14, 24, and 36 hours. Overall performance of the 10-mg group was poorer than that of the 4-mg group.
View Article and Find Full Text PDFAlzheimer Dis Assoc Disord
November 1989
We examined density (Bmax), affinity (Kd), and norepinephrine (NE)-stimulated cyclic adenosine monophosphate (cAMP) generation of the beta-adrenergic receptor on lymphocytes in patients with dementia of the Alzheimer type (DAT, n = 13), in normal aged controls (AGED, n = 27), and in young controls (YOUNG, n = 21). Bmax (fmol/mg protein; mean +/- SD) was significantly lower in YOUNG (48.0 +/- 18.
View Article and Find Full Text PDFPsychoneuroendocrinology
July 1989
To investigate the effects of neuroleptics on plasma thyrotropin (TSH) concentrations, haloperidol tablets were administered orally to 34 normal male volunteers. Seventeen of the subjects received 4 mg; the other 17 received 10 mg. Plasma samples were collected at baseline and 1, 3, 4, 6, 14, 24, 36, 48, 72 and 96 hr after drug administration.
View Article and Find Full Text PDFHaloperidol was administered to 12 subjects intravenously (0.125 mg/kg) and to nine subjects orally (0.5 mg/kg).
View Article and Find Full Text PDFJ Clin Psychiatry
January 1985
Haloperidol was administered orally to 6 male schizophrenic patients and intravenously to 3. Elimination half-life (t1/2 beta) and bioavailability (F) were calculated for both groups from haloperidol serum concentrations determined by gas-liquid chromatography. Mean (+/- SD) half-lives were 17.
View Article and Find Full Text PDFHaloperidol kinetics were determined after oral and intravenous drug doses in 15 men. Mean elimination t1/2 for the subjects was 17.9 +/- 6.
View Article and Find Full Text PDFSeventy-six male inpatients with diagnoses of schizophrenia, primary affective disorder, post-traumatic stress disorder, borderline personality disorder, other personality disorder, and primary substance abuse disorder were screened for the use of marijuana by determination of urinary delta-9-tetrahydrocannabinol-11-oic acid. Screening was performed to detect marijuana use in asymptomatic patients returning to the ward after passes, and also to elucidate changes in mental state in newly admitted patients and patients who had decompensated during hospitalization. Ward personnel found the screening procedure quite useful and incorporated it into psychotherapeutic and chemotherapeutic interventions.
View Article and Find Full Text PDFThe authors treated 16 outpatients and 1 inpatient who had diagnoses of schizophrenia in exacerbation with haloperidol as the sole neuroleptic agent and obtained ratings of psychopathology and serum levels of haloperidol. Improvement in schizophrenic symptoms measured by the Brief Psychiatric Rating Scale was significantly greater in patients who had mean haloperidol serum concentrations in the range of 8-18 ng/ml than in patients whose mean haloperidol serum concentration fell outside this range.
View Article and Find Full Text PDF