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Biomedical subjects

S R Dager

Publications and source records attributed to S R Dager.

At least 55 records · Page 3Linked to original sources
PubMed1990

Central nervous system effects of lactate infusion in primates.

The concentration of total lactate in cisternal fluid increased threefold, from 12.3 +/- 2.1 to 37.6 +/- 8.9 mg/dl, during a 20-min intravenous infusion of 1 M racemic sodium lactate (10 mEq/kg) in 3 anesthetized, mechanically ventilated baboons. Rises in cisternal lactate lagged behind arterial lactate increases, but occurred during the time interval in which susceptible humans typically panic in response to lactate infusion. Subsequent to cisternal lactate increases, cisternal pH and HCO3- concentration progressively increased during a 105-min interval following lactate infusion. No consistent changes in cisternal pCO2 occurred during or subsequent to lactate infusion. These preliminary findings fail to support the hypothesis that lactate-induced panic is mediated by increasing central nervous system pCO2. Instead, these data demonstrate that lactate can rapidly increase in the central nervous system during lactate infusion, suggesting new lines of investigation for studying the mechanisms responsible for lactate-induced panic.

Animals↗
PubMed1990

Bright light treatment of winter depression: morning versus evening light.

In a randomized crossover design, 7 patients with winter depression were treated with 7 d of bright morning light (0600 to 0800) and 7 d of evening light (2000 to 2200). Bright lights in the morning significantly reduced the Hamilton Rating Scale for Depression (HRSD) score (18.4 to 5.0); the bright light in the evening moderately decreased the HRSD score (19.4 to 15.1). The improvement in the HRSD score was significantly greater with morning light than with evening light.

Adult↗
PubMed1990

A case of bupropion-associated delirium.

The authors report a case of bupropion-associated delirium characterized by disorganized thinking, memory impairment, fear, and agitation but not disorientation, delusions, hallucinations, or other perceptual distortions. Symptom onset appeared to be dose-related, and a sustained therapeutic response was subsequently obtained at a lower dose of bupropion without recurrence of delirium. Abnormal bupropion metabolism and elevated plasma metabolite levels did not account for the adverse reaction, which instead was hypothesized to reflect dopaminergic effects of bupropion.

Antidepressive Agents↗
PubMed1990

Characteristics of placebo response during long-term treatment of panic disorder.

Mixed-panic disorder patients (16/60, 27%) randomly assigned to receive blind placebo during a 40-week treatment study were defined as placebo responders based on combined criteria of Hamilton Anxiety Scale score percentage decreases below the median point (-42%), moderate to marked improvement on both clinician and patient Clinical Global Impressions scores, and panic-free at final treatment visit. These criteria applied separately also resulted in a similar clinical grouping and pattern of response. Differential patterns of response between responders and nonresponders occurred across most clinical measures of panic/anxiety. Responders experienced early improvement within the first week of double-blind treatment. This response progressed during treatment and tended to persist during taper and at followup 1 month later. Post-hoc analysis of demographic and clinical features at entrance into the study failed to characterize this stringently defined group of placebo responders.

Adult↗
PubMed1989

Response to sodium lactate infusion in alcoholics with panic attacks.

The authors studied the response to sodium lactate infusion of 12 alcoholics with a history of panic attacks, 10 alcoholics without a history of panic attacks, and 16 nonalcoholic patients with panic disorder. The rate of lactate-induced panic was significantly higher in alcoholics with panic attacks than in alcoholics without panic attacks. Alcoholics with panic attacks were similar to nonalcoholic patients with panic disorder in their response to lactate. These findings support the specificity of lactate-induced panic for panic states and suggest that panic attacks in alcoholics resemble those in nonalcoholics. Lactate infusion may prove useful in the diagnosis of panic disorder in alcoholics.

Adult↗
PubMed1989

Relapse and rebound following discontinuation of benzodiazepine treatment of panic attacks: alprazolam versus diazepam.

The authors assessed the effects of partial tapering followed by abrupt discontinuation of alprazolam, diazepam, and placebo in 40 patients with panic attacks. The anxiety scores and frequency of panic attacks of the three groups did not differ at the end of the initial 2-week taper, but 1 week after abrupt discontinuation of the remaining medication, patients formerly taking alprazolam had greater increases in anxiety but no more panic attacks than did the other patients. Because of low statistical power, differences in benzodiazepine half-lives, absence of multiple ratings, and imbalances between groups in clinical characteristics, these findings must be viewed as preliminary.

Adult↗
PubMed1988

Response to lactate infusion in generalized anxiety disorder.

Intravenous sodium lactate infusion provokes symptoms of panic in patients with panic disorder at a significantly higher rate than in normal controls. Lactate sensitivity has been postulated to be specific for patients with panic attacks regardless of frequency of attacks or coexisting diagnoses. The authors present results of a pilot study of lactate infusions in patients with generalized anxiety disorder (GAD) without any history of panic attacks. Patients with GAD reacted more like panic disorder patients than like normal controls in anxiety and symptom scores during lactate infusion and in the rate of positive responses to lactate. Although preliminary, these findings raise questions regarding the specificity of lactate sensitivity and the relationship of GAD to panic disorder.

Adult↗
PubMed1988

Mitral valve prolapse and the anxiety disorders.

Confusing and contradictory results have emerged from studies of the relationship between anxiety disorders and mitral valve prolapse (MVP), a commonly occurring heart defect that has been associated with chest pain, palpitations, tachycardia, and arrhythmias. Patients with anxiety disorders, particularly panic attacks, appear to have an increased prevalence of MVP compared with control groups or the general population, although most individuals with MVP are asymptomatic. MVP does not appear to distinguish a subgroup of patients with panic disorder on the basis of vulnerability to panic attacks, symptom presentation, biological abnormalities, or treatment response. The authors review some current hypotheses about causal relationships between anxiety disorders and MVP, describe methods of diagnosing MVP and their shortcomings, and identify possible medical complications of MVP and ways to treat or prevent them.

Adult↗
PubMed1987

Biological markers in panic states: lactate-induced panic and mitral valve prolapse.

Anxious patients, and more specifically, patients experiencing panic attacks, are thought to have a significant biological component to their illness. This study looks at two promising biological markers associated with this patient population-mitral valve prolapse and lactate-induced panic. We present our findings, which further characterize clinical and biological aspects of these two markers.

Adolescent↗
PubMed1987

Lactate infusions in major depression without panic attacks.

Sodium lactate infusion provokes panic attacks in panic disorder patients but not in normal controls. We have previously shown that patients who develop panic disorder during a major depressive episode are similar to panic disorder patients in their rate of panic attacks with lactate. In the present pilot study, nine patients with major depression without panic attacks underwent lactate infusions. These patients differed significantly from panic disorder patients but not from controls in their response to lactate. This argues for the specificity of lactate sensitivity for the phenomenon of panic attacks and gives further evidence for biological differences between panic and depression.

Adolescent↗
PubMed1987

Lactate infusions: the role of baseline anxiety.

Sodium lactate infusions provoke panic symptoms in patients with panic attacks at a greater rate than in normal controls. The effect of the baseline, preinfusion state on subsequent response to lactate is the subject of debate. Baseline symptoms, anxiety levels, and autonomic arousal and subsequent response to lactate were examined in 44 panic patients and 10 normal controls. Patients who had a typical panic attack with lactate had higher baseline symptom ratings, but these did not fully account for differences in response to lactate. Although baseline measures are not the sole determinant of response to lactate infusion, they may be one factor influencing how readily a patient reaches the threshold for a panic attack.

Adult↗
PubMed1987

Mitral valve abnormalities and catecholamine activity in anxious patients.

We studied 38 anxiety disorder patients, 19 of whom had evidence of mitral valve abnormalities by two-dimensional echocardiography. The presence or absence of mitral valve abnormalities was not related to 3-methoxy-4-hydroxyphenylglycol/creatinine excretion, platelet and plasma monoamine oxidase-type activity, or autonomic arousal as measured by blood pressure and resting heart rate. These findings fail to support the hypothesis that mitral valve abnormalities identify a specific subpopulation of anxious patients with differences in catecholamine function.

Adult↗
PubMed1987

Clinical characteristics and response to sodium lactate of patients with infrequent panic attacks.

Nine patients with panic attacks too infrequent to meet DSM-III criteria for panic disorder were compared to 20 panic disorder patients with respect to clinical characteristics and response to sodium lactate infusion. The two groups showed similar clinical characteristics and response to lactate. The authors conclude that patients with infrequent panic attacks are clinically and biologically similar to those with panic disorder and discuss implications for the diagnosis of panic states.

Adolescent↗
PubMed1987

Panic disorder precipitated by exposure to organic solvents in the work place.

The authors describe three cases of idiosyncratic response to occupational solvent exposure, with symptoms characteristic of panic disorder (DSM-III). The specific treatment and prognostic implications of this panic-like reaction to solvents are discussed. Sodium lactate infusion is proposed as an objective test to aid in the diagnosis.

Adult↗
PubMed1987

Comparative efficacy of propranolol, chlordiazepoxide, and placebo in the treatment of anxiety: a double-blind trial.

The efficacy and safety of propranolol in the treatment of anxiety was compared with those of chlordiazepoxide and placebo in a 3-week, double-blind study of 212 patients. After a 1-week, single-blind placebo-washout period, patients were randomized to receive either propranolol (80, 160, or 320 mg/day), chlordiazepoxide (30, 45, or 75 mg/day), or placebo. Patients were evaluated by three physician-rated scales--Hamilton Rating Scale for Anxiety (HAM-A), Covi Anxiety Scale (CAS), and Clinical Global Impressions scale--and two patient-rated scales--Symptoms Checklist 90 and Profile of Mood States. Patients in all groups demonstrated significant improvement in their level of anxiety at all time points compared with their baseline level. At Week 1 propranolol and chlordiazepoxide patients were significantly better than placebo patients, as measured by the HAM-A and CAS. At Week 2 only propranolol was superior to placebo, based on HAM-A and CAS scores. Fifteen patients prematurely terminated because of adverse reactions (4 taking propranolol, 4 taking placebo, and 7 taking chlordiazepoxide). The incidence of side effects was similar for the two active drugs; fatigue, drowsiness, and change in libido were significantly more frequent with chlordiazepoxide and drowsiness and indigestion were more frequent with propranolol compared with placebo.

Adolescent↗