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Biomedical subjects

J C Fowler

Publications and source records attributed to J C Fowler.

At least 19 recordsLinked to original sources
PubMed2003

Systemic hypoxia and the depression of synaptic transmission in rat hippocampus after carotid artery occlusion.

The relationship between step reductions in inspired oxygen and the amplitude of evoked field excitatory postsynaptic potentials (fEPSPs) recorded from hippocampal CA1 neurons was examined in anaesthetized rats with a unilateral common carotid artery occlusion. The amplitudes of fEPSPs recorded from the hippocampus ipsilateral to the occlusion were significantly more depressed with hypoxia than were the fEPSPs recorded from the contralateral hippocampus. The adenosine A1-selective antagonist, 8-cyclopentyl-1,3-dimethylxanthine (8-CPT), blunted the hypoxic depression of the fEPSP. Tissue partial pressure of oxygen (Ptiss,O2) was measured in the ipsilateral and contralateral hippocampus using glass Clark-style microelectrodes. Ptiss,O2 fell to similar levels as a function of inspired oxygen in the ipsilateral and contralateral hippocampus, and in the ipsilateral hippocampus after administration of 8-CPT. Hippocampal blood flow (HBF) was measured using laser Doppler flowmetry. A decline in HBF was associated with systemic hypoxia in both hippocampi. HBF, as a function of inspired oxygen, fell significantly more in the ipsilateral than in the contralateral hippocampus. We conclude that endogenous adenosine acting at the neuronal A1 receptor plays a major role in the depression of synaptic transmission during hypoxic ischaemia. The greater susceptibility of the fEPSP in the ipsilateral hippocampus to systemic hypoxia cannot be explained entirely by differences in Ptiss,O2 or HBF between the two hemispheres.

Adenosine↗
PubMed2003

The effect of acute hypoxemia and hypotension on adenosine-mediated depression of evoked hippocampal synaptic transmission.

The present study was designed to investigate the relative contributions of arterial P(O(2)), local cerebral blood flow, and oxygen delivery to the adenosine A(1) receptor-mediated depression of evoked synaptic transmission recorded in the rat hippocampus. Urethane-anesthetized rats were given a unilateral common carotid artery occlusion and then placed in a stereotaxic apparatus for stimulation and recording of bilateral hippocampal field excitatory postsynaptic potentials (fEPSPs). Arterial blood gases, mean arterial blood pressure (MAP), and bilateral hippocampal blood flow (HBF) were also measured. Arterial P(O(2)), HBF, and oxygen delivery were manipulated using normoxic hypotension, hypoxic hypotension, and hypoxic normotension. Both hypoxic hypotension and normoxic hypotension resulted in decreased HBF, decreased oxygen delivery, and a depression of the evoked fEPSP limited to the hippocampus ipsilateral to the occlusion. The enhanced HBF and oxygen delivery associated with increased MAP resulted in a restoration and maintenance of hippocampal fEPSPs despite sustained hypoxemia. The adenosine A(1) receptor-mediated depression of the fEPSP was more strongly correlated with changes in HBF and oxygen delivery than with arterial P(O(2)). We propose that adenosine plays an important role mediating the depression of neuronal activity associated with reduced oxygen delivery characteristically observed in ischemic brain tissue.

Acute Disease↗
PubMed2001

Adenosine induces initial hypoxic-ischemic depression of synaptic transmission in the rat hippocampus in vivo.

The present study was designed to investigate the role of adenosine in the hypoxic depression of synaptic transmission in rat hippocampus. An in vivo model of hypoxic synaptic depression was developed in which the common carotid artery was occluded on one side in the urethane-anesthetized rat. Inspired oxygen levels were controlled through a tracheal cannula. Rats were placed in a stereotaxic apparatus for stimulation and recording of bilateral hippocampal field excitatory postsynaptic potentials. The percent inspired oxygen could be reduced to levels that produced a reversible and repeatable depression of evoked synaptic transmission restricted to the hippocampus ipsilateral to the occlusion. Further reduction in the level of inspired oxygen depressed synaptic transmission recorded from both hippocampi. The adenosine nonselective antagonist caffeine and the A(1) selective antagonist 8-cyclopentyltheophylline prevented the initial depression in synaptic transmission. We conclude that the initial depression of synaptic transmission observed in the rat hippocampus in vivo is due to endogenous adenosine acting at neuronal adenosine A(1) receptors.

Acid-Base Equilibrium↗
PubMed2001

An empirical study of seriously disturbed suicidal patients.

Aspects of unconscious processes in a group of seriously disturbed psychiatric patients are examined in an effort to predict near-lethal suicide attempts and explore psychoanalytic formulations of suicide. The Rorschach Inkblot Test, the most widely used projective measure in suicide research (Bongar 1991), was chosen for its potential to shed light on specific unconscious processes. Psychic states commonly associated with suicide were measured by psychoanalytic Rorschach analog scales and then subjected to a progression of statistical analyses in order to predict future occurrence and lethality of suicide attempts. On the basis of a priori hypotheses, the authors developed a suicide index comprising four psychoanalytic Rorschach signs that predicted, with considerable accuracy, which patients would later make near-lethal suicide attempts. The best predictors were unconscious processes indicative of penetrating affective overstimulation, disturbance in the capacity to maintain adequate ego boundaries, and depressive affective states characterized by a morbid preoccupation with death and inner decay. These findings provide empirical support for several well-known formulations of the unconscious motivations for suicide.

Adult↗
PubMed2001

Predicting DMS-IV cluster B personality disorder criteria from MMPI-2 and Rorschach data: a test of incremental validity.

Despite their frequent conjoint clinical use, the incremental validity of Rorschach (Rorschach, 1921/1942) and MMPI (Hathaway & McKinley, 1943) data has not been adequately established, nor has any study to date explored the incremental validity of these tests for predicting Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) personality disorders (PDs). In a reanalysis of existing data, we used select Rorschach variables and the MMPI PD scales to predict DSM-IV antisocial, borderline, histrionic, and narcissistic PD criteria in a sample of treatment-seeking outpatients. The correlational findings revealed alimited relation between Rorschach and MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) variables, with only 5 of 30 correlations reaching significance (p <.05). Hierarchical regression analyses showed that both the MMPI and Rorschach data add incrementally in the prediction of DSM-IV borderline and narcissistic PD total criteria scores. The findings were less clear for the incremental value of Rorschach and MMPI-2 data in predicting the total number of DSM-IV histrionic PD criteria, which were best predicted by Rorschach data, and antisocial PD criteria, which were best predicted by MMPI-2 data. In addition to providing evidence of the incremental validity of Rorschach data, these findings also shed light on the psychological characteristics of the DSM-IV Cluster B PDs.

Adult↗
PubMed2001

The Rorschach Suicide Constellation: assessing various degrees of lethality.

In this article we examine the relation between the Rorschach Comprehensive System's Suicide Constellation (S-CON; Exner, 1993; Exner & Wiley, 1977) and lethality of suicide attempts during the course of patients' hospitalization at the Austen Riggs Center (Stockbridge, MA). Patient records were rated as nonsuicidal (n = 37), parasuicidal (n = 37), or near-lethal (n = 30) based on the presence and lethality of self-destructive acts. Diagnostic efficiency statistics utilizing a cutoff score of 7 or more positive indicators successfully predicted which patients would engage in near-lethal suicidal activity relative to parasuicidal patients (overall correct classification rate [OCC] = .79), nonsuicidal inpatients (OCC = .79), and college students (OCC = .89). Although these predictions were influenced by relatively high base rates in the hospital population (14.5%), base rate estimates were calculated for other hypothetical populations revealing different prediction estimates that should be considered when judging the relative efficacy of the S-CON. Logistic regression analysis revealed that an S-CON score of 7 or more was the sole predictor of near-lethal suicide attempts among 9 psychiatric and demographic variables.

Adult↗
PubMed2001

Convergent validity of Rorschach and TAT scales of object relations.

The Rorschach Mutuality of Autonomy Scale (MOA) and the Social Cognition and Object Relations Scale (SCORS) have been shown to be reliable and valid measures of interpersonal functioning. Utilizing a sample of 57 outpatients with a Diagnostic and Statistical Manual of Mental Disorders Axis II diagnosis, this study extends the findings of previous research demonstrating the reliability and convergent validity of each measure. Analyses focused on the convergent validity between the Rorschach MOA Scale and 8 SCORS variables (complexity, affect, emotional investment in relationships, emotional investment in values and morals, understanding of social causality, management of impulses/aggression, self-esteem, identity/coherence of self) ratings of Thematic Apperception Test narratives. The conceptual nature and clinical utility of these findings are discussed in relation to psychological assessment.

Humans↗
PubMed2000

Polymorphism of human mucin genes in chest disease: possible significance of MUC2.

Most of the genes that encode epithelial mucins are highly polymorphic due to variations in the length of domains of tandemly repeated (TR) coding sequence, the part of the apomucin that is heavily glycosylated. We report here for the first time a difference in the distribution of MUC TR length alleles in chest disease. We examined the distribution of the length alleles of those MUC genes whose expression we have confirmed in the bronchial tree in an age- and sex-matched series of 50 pairs of atopic patients with and without asthma. There was no significant difference in the distribution of alleles of MUC1, MUC4, MUC5AC, and MUC5B. MUC2, however, showed a highly significant difference in distribution. The atopic, nonasthmatic individuals showed an allele distribution that was very different from all our other patient and control groups, this group showing a longer mean allele length. The observations suggest that longer MUC2 alleles may help protect atopic individuals from developing asthma, though the effect may be due to a linked gene. The biological significance of this variation with respect to susceptibility to asthma will merit further investigation, and it will also be important to substantiate this finding on an independent data set.

Alleles↗
PubMed2000

Martin Mayman's early memories technique: bridging the gap between personality assessment and psychotherapy.

In this article, we describe Martin Mayman's approach to early childhood memories as a projective technique, beginning with his scientific interest in learning theory, coupled with his interest in ego psychology and object relations theory. We describe Mayman's contributions to the use of the early memories technique to inform the psychotherapy process, tying assessment closely to psychotherapy and making assessment more useful in treatment. In this article, we describe a representative sample of research studies that demonstrate the reliability and validity of early memories, followed by case examples in which the early memories informed the therapy process, including issues of transference and countertransference.

Female↗
PubMed2000

Interpersonal dependency and personality pathology: variations in Rorschach Oral Dependency scores across Axis II diagnoses.

Although several investigations have examined the relationship of Rorschach Oral Dependency (ROD; Masling, Rabie, & Blondheim, 1967) scores to Axis I diagnosis, there has been very little research assessing variations in ROD scores across Axis II personality disorders (PDs). In this study, ROD scores were compared in 5 PD groups (borderline PD inpatients, borderline PD outpatients, avoidant-dependent PD outpatients, narcissistic PD outpatients, and antisocial PD outpatients), and 2 non-PD comparison groups (psychotic disorder inpatients and college students). Borderline PD inpatients had significantly higher ROD scores than borderline PD outpatients, antisocial PD outpatients, and college students; no other between-group differences were found. We discuss implications of these results for research on dependency and Axis II psychopathology and offer suggestions for future studies.

Adult↗
PubMed2000

Exploring the inner world of self-mutilating borderline patients: a Rorschach investigation.

Psychiatric patients who engage in self-destructive behavior by cutting, burning, or abrading their skin are currently one of the most difficult-to-treat groups in both inpatient and outpatient settings. The complexities of treating these patients, the risk factors associated with this symptom, and the rise in the prevalence of self-mutilation in America's adolescents and young adults provided the impetus for the current study. This article explores aspects of aggression, dependency, object relations, defensive structure, and psychic boundary integrity that may contribute to the genesis and maintenance of self-mutilation. Rorschach protocols from 90 borderline personality-disordered inpatients (48 self-mutilators and 42 non-self-mutilators) were scored using five psychoanalytic content scales. Results indicate that self-mutilating patients exhibit greater incidence of primary process aggression, severe boundary disturbance, pathological object representations, defensive idealization, devaluation, and splitting than did a matched group of non-self-mutilating borderline patients. Clinical theory and technical recommendations are considered in light of the current empirical findings.

Adult↗
PubMed2000

The effects of social cognition and object representation on psychotherapy continuation.

This study investigates the extent to which the number of psychotherapy sessions attended is predicted by the Rorschach Mutuality of Autonomy Scale (MOA; Urist, 1977), Holt primary (A1) and secondary (A2) process aggression variables (Holt, 1977), and ratings of Thematic Apperception Test (TAT) narratives using Westen's (1995) eight Social Cognition and Object Relations Scale (SCORS) variables (complexity of representation of people, affective quality of representations, emotional investment in relationships, emotional investment in values and moral standards, understanding of social causality, experience and management of aggressive impulses, self-esteem, identity and coherence of self). Seventy-six patients with a DSM-IV Axis II diagnosis participated in this study. Two separate stepwise regression analyses (one for Rorschach variables, N = 76, and one for the SCORS ([TAT]) variables, n = 63) indicated that the Rorschach MOA PATH score (sum of scale points 5, 6, and 7; positive), as well as two individual SCORS variables (in order of relative magnitude, affective quality of representations, negative, and emotional investment in relationships, positive), were predictive of the number of psychotherapy sessions attended by patients. The conceptual nature and clinical utility of these variables are discussed in relation to the termination and continuation of psychodynamic psychotherapy.

Female↗
PubMed1999

Hydroxylamine blocks pre- but not postsynaptic adenosine A(1) receptor-mediated actions in rat hippocampus.

The commonly used nitric oxide donor, hydroxylamine (NH(2)OH), can block or reverse the inhibition of glutamatergic transmission by adenosine or an adenosine A(1) agonist in rat hippocampal slice. In these experiments, hydroxylamine did not affect the adenosine A(1) receptor-mediated depression of postsynaptic excitability. We conclude that hydroxylamine acts presynaptically to counter adenosine A(1) receptor-mediated inhibition of synaptic transmission.

Adenosine↗
PubMed1999

Hydroxylamine blocks adenosine A1 receptor-mediated inhibition of synaptic transmission in rat hippocampus.

The nitric oxide donor hydroxylamine (NH2OH) induced a transient depression of the evoked synaptic potential recorded in the rat hippocampal CA1 region. This depression was abolished with an adenosine A1 antagonist, 8-cyclopentyltheophylline. In addition, hydroxylamine reversed adenosine A1 receptor-mediated inhibition of the evoked population spike, the fEPSP and the intracellularly recorded EPSP. The inhibitory modulation of adenosine A1 receptor activation by hydroxylamine suggests the presence of a potent endogenous regulatory site.

Animals↗
PubMed1999

A Rorschach exploration of the DSM-IV Borderline Personality Disorder.

Rorschach data has been useful in identifying the DSM Borderline Personality Disorder (BPD) and has potential for improving our understanding of this disorder. Recently, the DSM-IV BPD has been shown to be composed of 3 primary or core factors: Factor I-unstable self-other images. Factor II-deficits in affect and thought modulation, and Factor III-impulsive self-damaging actions. In a sample of outpatients with personality disorders. we explored the relationships among 6 psychoanalytically derived Rorschach scales (primitive aggression, oral dependency, self-other differentiation, splitting, devaluation, and projective identification), and the core BPD features. Significant correlations were found between 5 of the Rorschach variables and BPD total scores. Correlations between these 5 variables and the BPD core features showed that oral dependency needs were negatively associated with all 3 BPD core features, whereas the defenses of devaluation and splitting were positively associated with these core features. The clinical implications of these findings are reviewed.

Adult↗
PubMed1999

Diagnostic efficiency and hierarchical functioning of the DSM-IV borderline personality disorder criteria.

This study presents information regarding the diagnostic efficiency and hierarchical functioning of the newly revised DSM-IV borderline personality disorder (BPD) criteria. Past research using the DSM-III-R version of BPD showed that the individual BPD criteria differ greatly in their diagnostic utility and that in some clinical situations, fewer than five of eight criteria could efficiently make the diagnosis. Two groups of inpatients, a BPD group (N = 33) and a non-BPD group (N = 43), were rated on the DSM-IV BPD criteria. Acceptable interrater reliability (Kappa estimates) was obtained for the presence or absence of the nine individual BPD criteria. Diagnostic efficiency statistics, sensitivity, specificity, false positive and false negative rates, positive predictive power, negative predictive power, overall classification rate and Kappa with the clinical diagnosis were obtained for all nine BPD criteria. The diagnostic efficiency data indicated that BPD criteria 1 (abandonment) and 2 (unstable relationships) functioned best in our inpatient sample, whereas criterion 9 (stress-related paranoia) performed the poorest. A stepwise logistic regression showed that the combination of BPD criteria 2, 1, 6 (unstable affect), and 3 (identity) (presented in their order of entry into the regression equation) provided the best prediction of group membership (BPD or non-BPD). The results suggest that a further refinement of both the BPD criteria set and the diagnostic decision rules may be needed.

Adult↗
PubMed1998

Contributions of Na+ flux and the anoxic depolarization to adenosine 5'-triphosphate levels in hypoxic/hypoglycemic rat hippocampal slices.

A 10 min exposure of rat hippocampal slices to hypoxic/hypoglycemic medium decreased tissue adenosine 5'-triphosphate (ATP) levels. Hypoxia/hypoglycemia also caused an anoxic depolarization and essentially no recovery of the synaptically evoked population spike from CA1 region recorded 30 min after re-introduction of normoxic/normoglycemic medium. Removal of Ca2+ or the addition of either the non-competitive N-methyl-D-aspartate antagonist dizocilpine maleate, the inorganic Ca2+ channel antagonist Co2+; or the Na+ channel blocker tetrodotoxin to hypoxic/hypoglycemic medium improved recovery of the evoked population spike upon re-oxygenation. Dizocilpine maleate, Co2+, and tetrodotoxin spared ATP during exposure to hypoxia/hypoglycemia. In contrast, Ca(2+)-free medium facilitated recovery of the population spike but did not preserve ATP during hypoxia/hypoglycemia. Dizocilpine maleate, Co2+ or dantrolene, when added to Ca(2+)-free medium, did not preserve ATP. Tetrodotoxin, when added to Ca(2+)-free medium, was effective in sparing ATP in hypoxic/hypoglycemic medium. To determine the effect of anoxic depolarization on ATP levels, hippocampal slices were collected just before and after the depolarization. There appeared to be an abrupt drop in ATP associated with the anoxic depolarization. We conclude that Na+ influx plays a relatively larger role in ATP consumption during hypoxia/hypoglycemia than Ca2+ influx. In addition, the anoxic depolarization imposes a large and rapid drop in ATP levels.

Adenosine Triphosphate↗