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Biomedical subjects

A Breier

Publications and source records attributed to A Breier.

At least 217 records · Page 12Linked to original sources
PubMed1986

Differential diagnosis and diagnostic systems in schizophrenia.

Diagnosis and prognosis are critical issues confronting psychiatry. In order to answer the fundamental questions concerning the origin and development of schizophrenia, we must first be clear about what it is. We must be able to separate the illness of schizophrenia from other disorders (see Fig. 1). We have attempted in this article to examine some of the illnesses that may resemble schizophrenia and make its discrimination difficult. We hope that by discussing these disorders and their similarities to schizophrenia the important issues and dilemmas have become clearer and more readily understood by the clinician. Future studies assessing the validity of diagnostic systems for schizophrenia may have to rely on features other than cross-sectional symptoms and longitudinal course. Such characteristics as pharmacologic responsivity and genetic transmission and the development of biologic markers may be the prospective cornerstones for validating the diagnosis of schizophrenia.

Bipolar Disorder↗
PubMed1985

Life events in depression. Relationship to subtypes.

Life events that had occurred in the 6 months before the onset of depression were recorded in 40 depressed patients and 41 normal controls. The depressed patients had experienced significantly more life events and significantly more undesirable life events than the controls. The 20 patients with a DSM-III diagnosed major depressive episode (MDE) without melancholia had experienced significantly more life events in the 6 months before the onset of depression than the 20 patients with a major depressive episode with melancholia. The patients with MDE without melancholia, but not the MDE with melancholia patients, had also experienced significantly more life events than a group of age- and sex-matched normal controls.

Adult↗
PubMed1985

The diagnostic validity of anxiety disorders and their relationship to depressive illness.

Several serious questions exist regarding the diagnostic classification of anxiety disorders. The authors examine the diagnostic validity of generalized anxiety disorder and panic disorder and explore their relationship to major depression, critically reviewing relevant descriptive, lifetime occurrence, family and genetic, drug treatment, and neurobiological studies. There is strong support for the diagnostic validity of panic disorder, but few data are found to support a separate diagnostic classification of generalized anxiety disorder. In addition, several lines of evidence suggest that a common vulnerability may exist for some forms of panic disorder and major depression. The implications of these findings for diagnostic application, treatment, and future research are discussed.

Anti-Anxiety Agents↗
PubMed1985

Exaprolol as a modulator of heart sarcolemmal (Na+ + K+)-ATPase. Evidence for interaction with an essential sulfhydryl group in the catalytic centre of the enzyme.

Beta-adrenoceptor blocking agents may have, in addition to their primary action, also ancillary effects on the cell membrane. In the present paper the non-specific interaction of exaprolol with the ATPase systems in isolated rat heart sarcolemmal membranes was investigated. When preincubated with sarcolemmal membranes in vitro, exaprolol in concentrations below 10(-4) mol.l-1 had no significant effect on sarcolemmal Mg2+-, Ca2+- and (Na+ + K+)-ATPase activities. At exaprolol concentration of 10(-4) mol.l-1 the Mg2+- and Ca2+-ATPase activities became inhibited whereas the (Na+ + K+)-ATPase activity was markedly stimulated. A kinetic analysis of these interactions revealed a non-competitive inhibition of Mg2+- and Ca2+-ATPase. In the case of (Na+ + K+)-ATPase a synergistic type of stimulation characterized by an exaprolol-induced conversion of an essential sulfhydryl group in the active site of the enzyme to the more reactive [S-] form has been observed thus increasing the affinity of the enzyme to ATP. Exaprolol concentrations exceeding 5 X 10(-4) mol.l-1 induced an overall depression of the investigated enzyme activities.

Adenosine Triphosphatases↗
PubMed1985

Quantitative relationship between the protein secondary structure in cardiac sarcolemma and the activity of the membrane-bound Ca2+-ATPase.

In the absence of ATP, increasing concentrations of calcium within a range between 0.1--8.0 mmol . 1(-1) gradually lowered the alpha-helix content of proteins in rat heart sarcolemma requiring no energy supply. In the presence of ATP, similar concentrations of calcium stepwise activated the sarcolemmal low-affinity Ca2+-ATPase. A mathematical analysis of the data obtained revealed a quantitative relationship between calcium-induced stimulation of the Ca2+-ATPase activity and a diminution of the alpha-helix contents of membrane proteins in cardiac sarcolemma. The cooperation between changes in protein conformation and energy consumption in relation to the supposed role of low-affinity Ca2+-ATPase in gating the calcium channel are discussed.

Animals↗
PubMed1984

Noradrenergic function in panic anxiety. Effects of yohimbine in healthy subjects and patients with agoraphobia and panic disorder.

Yohimbine, an alpha 2-adrenergic receptor antagonist that increases noradrenergic function, was administered to 20 healthy subjects and 39 drug-free patients with agoraphobia and panic attacks. Following drug administration, changes in plasma levels of the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG), BP, pulse rate, and subjective ratings of feelings and somatic symptoms were examined during a four-hour period. Yohimbine produced significantly greater increases in patient-rated anxiety, nervousness, palpitations, hot and cold flashes, restlessness, tremors, piloerection, and sitting systolic BP in the total patient group compared with healthy subjects. There were significant correlations between the yohimbine-induced rise in plasma MHPG level and patient-rated anxiety and nervousness and the frequency of reported panic attacks. Patients experiencing frequent panic attacks (greater than 2.5 per week) had a significantly greater plasma MHPG response to yohimbine than the healthy subjects and patients having less frequent panic attacks. These observations support a hypothesis of increased sensitivity to augmented noradrenergic function in anxiety states associated with panic, and they suggest that impaired presynaptic noradrenergic neuronal regulation may exist in patients with frequent panic attacks.

Adult↗
PubMed1984

Major depression in patients with agoraphobia and panic disorder.

A review of the life-time occurrence of major depression, the temporal relationship of major depression to episodes of panic and agoraphobic disorders, and the severity of anxiety and depressive symptoms were determined in 60 patients with agoraphobia or panic disorder. Forty-one (68%) of the patients had a past or current episode of major depression, and 35 (85%) of these patients had endogenous-type major depression. Twenty patients (33%) had an episode of primary major depression, and an average of three years separated the end of primary major depression and the first panic attack. Secondary major depression occurred in 28 patients. Patients with a history of major depression had a more severe anxiety disorder. These data support the view that in a subgroup of patients, episodes of depression and panic anxiety disorder may be manifestations of a common underlying pathogenic process.

Adolescent↗
PubMed1984

Simple estimation of carrier binding capacity using sorption kinetics curve-fitting.

Kinetic curves of the sorption of biological-like compounds and proteins onto insoluble carriers were determined either by linearisation via double reciprocal transformation or by non-linear fitting using the following equation: B = (1/K1) X [t/(t + K2/K1)]. Both these procedures provided non-significant differences in the values of parameters of sorption kinetics, namely of equilibrium sorption (BM), sorption half-time (t1/2) and initial sorption rate (vo). Moreover, these methods proved to be sufficient to provide a precise description of the kinetics of different types of sorption, such as chemical, physical, ionic, biospecific and non-specific sorption. Both computing procedures make it possible (i) to calculate the parameters BM, t1/2 and vo even in instances where they cannot be established experimentally, and (ii) to replace the graphic estimation with computation. The assumption that all types of sorption mentioned above will be kinetically controlled in a uniform way proved to be reasonable.

Adsorption↗
PubMed1984

Characterization of schizophrenic patients who commit suicide.

Twenty schizophrenic patients who committed suicide were compared with a randomly selected group and a sex-matched group of nonsuicidal schizophrenic patients and with a group of nonschizophrenic patients who committed suicide. The schizophrenic patients who committed suicide were more often men, and tended to be young, never married, non-Protestant, and white. They failed to communicate their suicidal intent directly, used highly lethal suicide methods, and tended not to have undergone stressful life events associated with their suicides. A thorough, case-by-case clinical assessment of potential suicidal ideation is essential with schizophrenic patients.

Adult↗
PubMed1984

The role of social relationships in the recovery from psychotic disorders.

Little attention outside the therapeutic setting has been given to specifying the aspects of social relationships that might be helpful for patients recovering from psychotic episodes. The authors studied 20 patients who had been hospitalized for a psychotic episode for 1 year following discharge to examine the role their social relationships played during this period. The data show that 12 functions of social relationships were important and that there were two phases of social needs--convalescence and rebuilding--over the recovery period. The authors discuss the theoretical and clinical implications of these findings.

Adult↗
PubMed1983

Self-control in psychotic disorders.

Our follow-up study of 20 psychiatric patients and a review of the relevant literature support the idea that some persons may be able to exert control over their own psychiatric symptoms. This self-regulation process consists of three phases: In the first phase, persons become aware of the existence of psychotic or prepsychotic behavior by self-monitoring. In the second phase, self-evaluation, the person recognizes the implications of these behaviors as a signal of disorder. In these phases, detecting early affective signals that may herald the onset of psychotic symptoms and noting the sequences of events often followed by symptoms are particularly important. Once these symptoms or their precursors are detected, phase 3 occurs in which mechanisms of self-control are employed. Three such mechanisms are particularly common: self-instruction, reduced involvement in activity, and increased involvement in activity.

Adaptation, Psychological↗
PubMed1983

Selective and reversible inhibition of heart sarcolemmal (Na+ + K+)-ATPase by p-bromophenyl isothiocyanate. Evidence for a sulfhydryl group in the ATP-binding site of the enzyme.

Isothiocyanates are potent modifiers of thiol groups, and they have been successfully applied in studying the active site structure of renal (Na+ + K+)-ATPase. However, very little has been known on interactions of isothiocyanates with myocardial sarcolemmal ATPases. In the present study the mode of interaction and inhibitory effect of p-bromophenyl isothiocyanate (BPITC) on isolated rat heart sarcolemmal preparation ATPase activities not exhibiting (Mg-Ca)-ATPase activity was investigated. BPITC in concentrations of 10(-7)-10(-4) mol . l-1 inhibited selectively and non-competitively the (Na+ + K+)-ATPase activity in the sarcolemma with an ID50 around 2.10(-7) mol . l-1. The non-specific interaction of BPITC with bivalent cations, namely with Mg2+ and Ca2+, in the reaction system was eliminated by preincubation of membranes with BPITC keeping the ratio of inhibitor to membrane protein concentration constant. Under these conditions no considerable inhibitory effects were observed on Mg2+-ATPase or the low-affinity Ca2+-ATPase of sarcolemma. Preincubation of membranes with 2 mmol . l-1 ATP protected (Na+ + K+)-ATPase activity against inhibition by BPITC. The interaction of BIPTC with the sarcolemma proved to be reversible in the presence of beta-mercaptoethanol or dithiothreitol.

Adenosine Triphosphate↗