Normal P300 in acute schizophrenics during a continuous performance test.
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Acute Disease↗
Biomedical subjects
R R Engel
Publications and source records attributed to R R Engel.
CO production by feces and urine.
Virtually all CO production in humans and animals is thought to result from the catabolism of heme, and endogenous CO production (VCO) is used as a measure of heme turnover. Using a rebreathing technique, we found that previously fed mice had an apparent VCO that was 40% greater than that of mice that had been fasted before the study. This unexpected result was shown to reflect an excess CO production by the excreta (feces, urine, or both) of fed mice relative to the excreta of fasted mice. Incubation of feces and urine of humans, rats, and mice demonstrated CO release that was not inhibited by autoclaving or acidification to pH 1. CO release from excreta was markedly reduced, however, under anaerobic conditions, and fed and fasted animals excreted CO at the same rate when their excreta were maintained in an anaerobic state. We conclude that feces and urine can release CO via nonenzymatic, oxidative reactions and, under some circumstances, this source of CO can influence measurements of VCO.
Animals↗
Selected aspects of AIDS among homosexual men.
This report is a brief summary of important points concerning AIDS and homosexual men. We present the current overall figures of the cumulative AIDS incidence for Switzerland, the United States and the world and similar figures for homosexual men in Switzerland, the United States and Europe. A brief history of the epidemic is included with focus on the role of homosexual men. The main risk factors for acquiring HIV infection among homosexual men, including large numbers of sexual partners, receptive and intercourse and rectal douching, are mentioned with emphasis on results from "The San Francisco Men's Health Study". The development of education and prevention programs is outlined along with the role in these areas of The Swiss AIDS Foundation and Swiss Federal Office of Public Health. Decreases in high risk sexual practices and decrease in seroconversion rates are also discussed.
Acquired Immunodeficiency Syndrome↗
Cognitive deficits in aging and therapeutic evaluation of encephalotropic substances.
Several aspects relevant for the evaluation of encephalotropic substances are presented. A) Memory improving pharmacological effects found in animal studies are often lacking in human studies. B) Global clinical measures of therapeutic success differenciate well between verum and placebo. In contrast to psychological tests, however, objectivity and reliability of global measures is low. C) Diagnosing dementia requires laboratory screening, psychiatric judgment and psychological testing. Psychological theories about age-related decline of different cognitive abilities and psychiatric DSM-III criteria of dementia are however not congruent. One reason for this discrepancy is that psychological theories seldom consider the very old, where dementia is present in sufficient degree. We were able to demonstrate this in a pilot study with 51 residents of a home for the aged, whose average age was 81 years. The subtest Similarities (WAIS), a measure of conceptual ability usually considered to be stable throughout the aging process, showed a marked decline after age 75 in accordance with the psychiatric criterion of dementia, impairment of abstract thinking.
Aged↗
Perception of waking and sleeping: possible implications for the evaluation of insomnia.
Perception of awakening, its connection to electroencephalogram (EEG), and its significance for morning recall were studied in insomniacs and normals. Fourteen insomniacs and 14 age- and sex-matched controls kept a sleep log for 1 week and slept once in the laboratory (standard polygraphy). In addition, actual perception of awakening was measured by a behavioral device. Results suggest that physiological arousal is necessary, but not sufficient, for perception of awakening. Many arousals that are not perceived occur during the first REM-NREM cycle. Insomniacs nearly exclusively perceive those arousals occurring after consolidated sleep (at least 15 min) and at the beginning of interrupted sleep intervals. It is suggested that insomniacs perceive these intervals as continuous wakefulness and have difficulty in perceiving short-lasting sleep, whereas controls often do not perceive wakefulness at all. The latter may be a sleep-protecting mechanism. Number and correlation suggest that recalled awakenings are exactly those perceived. The connection between physiological and experimental subjective data is discussed.
Adult↗
Psychophysiological differentiation of two types of anxiety and its pharmacological modification by minor tranquillizer and beta-receptor-blocker.
To evaluate the influence of beta-blockers and/or minor tranquillizers on autonomic reactions during brief stress, 48 healthy subjects were randomised into 4 groups: A = 4 mg Pindolol, B = 1.5 mg Cloxazolam, C = Placebo, D = 4 mg Pindolol + 1.5 mg Cloxazolam. Subjects underwent four stress situations: Counting, noise, mental arithmetic and ergometry, each lasting 4 min with rest periods of 8 min in between. Electromyogram, finger pulse amplitude, heart rate, pulse wave velocity and electrodermal activity were recorded simultaneously on-line. Analysis of variance showed that the two drugs had significant main effects in different systems: Pindolol reduced heart rate, mainly during mental arithmetic and ergometry, Cloxazolam reduced electrodermal activity, mainly during noise. It can be concluded that different structured situations with a varying amount and type of anxiety induce different autonomic reactions; these reactions can be differentially modified by the drugs applied.
Adult↗
Tin protoporphyrin inhibits carbon monoxide production in adult mice.
We studied the effect of tin protoporphyrin, a potent inhibitor of heme oxygenase (EC 1.14.99.3), on carbon monoxide (CO) production in mature mice. Measurements of CO production provide a sensitive, noninvasive means of quantitating heme catabolism. CO accumulation in the gas space of closed chambers was decreased by about 25% for mice treated with two 50 nmol/g doses of tin protoporphyrin as compared to saline-treated controls. Calculated rates of CO production were 0.28 +/- 0.07 and 0.40 +/- 0.05 nmol X g-1 X h-1 for mice injected with tin protoporphyrin and saline, respectively (p less than 0.01). When hemin (125 nmol/g) was administered to simulate hemolysis, CO production increased markedly in both saline- and tin protoporphyrin-treated mice. However, the rate of CO production in tin protoporphyrin-treated mice was only 44% that of saline-treated animals (p less than 0.0001). These studies demonstrate that tin protoporphyrin inhibits heme catabolism in both the basal- and heme-loaded states and confirm that this inhibition is at the heme oxygenase step in the heme to bilirubin pathway.
Animals↗
Effect of ventilation on breath hydrogen measurements.
Measurement of hydrogen (H2) in expired air by interval sampling after oral administration of carbohydrate detects sugar malabsorption. Standard breath H2 tests require comparison of H2 concentrations in expired air samples obtained immediately before and after delivery of a test substrate. Comparison of interval samples assumes that minute ventilation (VE) remains constant unless H2 is independent of VE. Because healthy individuals have variable VE, we determined how H2 is influenced by changes in VE. H2 concentration was studied at different ventilatory rates in eight healthy adults. It varied inversely with VE in all subjects. We also compared the effect of changes in VE on the relationship between H2 and carbon dioxide (CO2) concentrations in expired air samples. At constant VE, the relationship between H2 and CO2 was linear (r = 0.95, P less than 0.001). As VE changed, the relationship between H2 and CO2 became nonlinear. Changes in VE altered methane concentrations in expired air samples from two subjects in a manner comparable to the effect on H2. These results demonstrate that breath H2 concentrations vary with ventilatory rate. Under conditions where frequent changes in VE are likely, independent measures for ensuring constant VE over sampling times are necessary. Use of CO2 as an internal standard to normalize H2 values to an alveolar concentration is appropriate only under conditions of constant VE.
Adult↗
[Non-drug therapy of hyposomnias].
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Behavior Therapy↗
Endogenous opiates increase pain tolerance after stress in humans.
This study investigates the role of endogenous opioids in the regulation of pain in humans. Two groups of healthy volunteers were subjected to different stress situations (cold pressor and arithmetic). In a double-blind design the changes in pain tolerance after stress were measured after an injection of either 0.8 mg naloxone or placebo. The cold pressor test raised the pain threshold in the placebo-treated group, but not in the naloxone-treated group. Mental arithmetic had no effect on pain perception. One can conclude therefore that physical stress may change pain perception depending upon the secretion of endogenous opioids.
Adult↗
Cardiopulmonary sequelae of reparative stages of bronchopulmonary dysplasia.
Seventy-three infants died after intensive respiratory therapy that included supplemental oxygen; their survival ranged from three to 225 days. Pulmonary alterations began with an exudative, early reparative stage and progressed to subacute and chronic fibroproliferative stages that correlated with stages 2 through 4 of bronchopulmonary dysplasia. Cardiopulmonary complications of interstitial fibrosis, emphysema, and cor pulmonale were most pronounced in the longest survivors and were associated with progression of the reparative response to the chronic fibroproliferative stage. An obliterative bronchiolitis was also a frequent manifestation of this reparative response, which may account for cystic bronchiolectasis observed in five infants. Ultrastructural studies indicated that the type 2 pneumocyte contributed to the reparative and proliferative reactions by reepithelialization of damaged septal walls and incorporation of hyaline membranes into septal walls that seemed to stimulate interstitial fibroplasia.
Bronchi↗
Situational reactivity of autonomic functions in schizophrenic patients.
In a study designed to evaluate the state of arousal and the autonomic reactivity to experimental conditions in schizophrenic patients, 12 acute, unmedicated schizophrenic patients with paranoid hallucinatory symptomatology and 63 healthy normal control subjects were administered four standardized tasks: cold pressor test, noise, mental arithmetic, and active relaxation. Biochemical (norepinephrine and cortisol) and physiological (electromyogram, electroencephalogram, skin and conductance response, skin conductance level, finger pulse amplitude, finger temperature, heart rate, respiratory volume, pulse wave velocity, and electrogastrogram) parameters were measured simultaneously. Schizophrenic patients showed elevated levels of cortisol and norepinephrine, as well as heightened responsivity on measures of electromyographic activity, skin conductance level, and heart rate, throughout the trial, and reduced responsivity to conditions of stress. It is concluded that schizophrenic patients show higher nonspecific activation and reduced ability to react to external stimulation, perhaps induced by lack of inhibition of the reticular formation by the limbic system.
Acute Disease↗
Experimental stress situations and the state of autonomic arousal in schizophrenic and depressive patients.
The influence of short-time emotional and cognitive stimuli on autonomic functions and plasma catecholamines was investigated in 12 paranoid schizophrenics, 12 endogenous depressive patients, and 63 normal controls. The schizophrenics showed higher norepinephrine levels, depressives higher epinephrine levels; in both groups of patients most of the physiological parameters were elevated throughout the trial, showing, on the other hand, reduced responsiveness to external stimulation.
Adult↗
Decreased insulin binding in cultured lymphocytes from two patients with extreme insulin resistance.
[125I]Insulin binding has been studied in two patients with extreme insulin resistance using cultured B-lymphocytes transformed with Epstein-Barr virus. A cell line from a female infant with leprechaunism had insulin binding which was decreased 90% below the lower limit of normal. Lymphocytes from a young woman with type A extreme insulin resistance (associated with acanthosis nigricans and virilization) had insulin binding which was 80% depressed. In both cases, the defect in binding resulted from a decrease in the number of receptors per cell. The remaining receptors had normal properties, including a normal affinity for insulin and a normal specificity for insulin analogs. Insulin binding in cultured lymphocytes from these two insulin-resistant patients was also inhibited normally by antibodies to the insulin receptor. Immunological assays using anti-receptor antibodies confirmed the conclusion that the number of receptors was decreased. Affinity labeling of the leprechaun insulin receptor with [125I]insulin demonstrated the existence of an alpha-subunit with apparently normal molecular weight (130,000 daltons). However, the number of receptor molecules per cell appeared reduced.
Adolescent↗
Nuances or nuisances for cutaneous bilirubinometry?
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Bilirubin↗
[Studies on stress in psychiatric patients (author's transl)].
Starting from the consideration that the assumed disturbances of the limbic system in psychiatric patients must lead, among other things, to functional autonomic disorders, the physiological reactions of previously untreated depressive and schizophrenic patients to short-lasting experimental stress situations were compared with those of healthy subjects. Whereas the plasma catecholamine levels and the autonomic functions of healthy subjects were easily foreseeable and reacted adequately to the situation, the two groups of patients showed a high degree of general unspecific activation even, eg in resting situations, associated with a relatively slight reaction to stress situations. How far these findings are of significance in the clarification of therapeutic methods in those patients exposed to increased stress is discussed.
Depressive Disorder↗
The effect of circumcision on transcutaneous PO2 in term infants.
To assess the effect of pain on PaO2 in newborns, transcutaneous PO2 (tcPO2) was monitored in ten healthy male infants undergoing circumcision. The tcPO2 was seen to decrease to a lower level with pain and to remain low with continuing pain. After the circumcision, the tcPO2 increased to levels equal to or exceeding those of the preoperative baseline period. Close corcordance of tcPO2 above and below the waist demonstrated no right-to-left shunting through the ductus arteriosus.
Circumcision, Male↗
[Validity of computer-generated MMPI reports in psychiatric patients (author's transl)].
Lachar's (1974) completely documented, automated MMPI interpretational system was transplated into German and analyzed regarding validity and generalizability in 1190 German psychiatric inpatients. The 114 paragraphs of the text library, each interpreting independent aspects of the MMPI profile, were rated for their accuracy in each individual report by the psychiatrist in charge for the respective patient. As an average, 83 of every 100 printed paragraphs were rated as 'accurate.' Further analysis revealed that the accuracy of paragraphs describing elevated MMPI profiles was substatially higher than in those describing profiles within the normal range. Accuracy rates of individual paragraphs correlated significantly (r = 0.61) with those reported by Lachar, thus confirming the specific accuracy of each paragraph. It is concluded that the present MMPI interpretational system offers descriptive clinical reports that have shown a high accuracy in culturally diverse psychiatric settings.
Adult↗