Growth hormone and cortisol responses to psychological stress: comparison of normal and neurotic subjects

The mirror drawing test (MDT) was performed to induce acute psychological stress in 9 normal controls and 10 neurotic subjects. Plasma growth hormone (GH) and cortisol were determined serially before, during, and after the test. In controls the MDT caused no significant change in plasma GH level, while in neurotics plasma GH increased progressively following the test. The increase of cortisol also tended to be greater in neurotics as a group, but there was considerable overlap in individual responses. The maximum increments of GH in neurotics correlated inversely with those of cortisol. The results indicate: 1) effective psychological coping mechanisms operate in normal man to keep the hormonal response minimum. 2) GH response is a more adequate indicator than cortisol response to psychological stress in neurotics. 3) GH and cortisol may have different psychological correlates in neurotics.     

Short-latency EMG potentials elicited by head taps in sternocleidomastoid muscles: a study on normal human subjects and patients with central or vestibular lesions

Ten subjects with diabetes mellitus and unilateral chronic foot ulcer were investigated. Local tissue concentrations of glucose and lactate were measured using the microdialysis method at a distance of 0.5-1 cm from the edge of the ulcer and in normal skin in the contralateral foot. Subcutaneous blood flow in the area investigated was measured using the 133Xewashout technique. The interstitial glucose concentration in the ulcer was found to be lower than in intact skin (8.0 +/- 1.0 mmol l-1 vs. 8.5 +/- 1.1 mmol l-1) (P < 0.02), and the interstitial lactate concentration was higher in the ulcer than in intact skin (3.2 +/- 0.2 mmol l-1 vs. 2.1 +/- 0.3 mmol l-1) (P < 0.01). The subcutaneous blood flow was on average 40% higher in the ulcer than in the intact skin. The calculated local glucose uptake and lactate outputs were twofold higher in the ulcer than in the intact skin. However, the molar ratio between lactate output and glucose uptake was approximately two, both in the ulcer and in the intact skin, indicating that the glucose metabolism was qualitatively the same in the two regions.     

Functional characteristics of bronchial epithelium obtained by brushing from asthmatic and normal subjects

Airways epithelial cells may be involved in the pathogenesis of asthma, but their role remains to be determined. Epithelial cells can release large amounts of 15-hydroxy-eicosatetranoic acid (15-HETE) and smaller amounts of prostaglandin E2 (PGE2) as well as fibronectin, a mediator involved in epithelial repair after injury. Epithelial cells obtained after bronchial brushing of 16 asthmatic (age 38 +/- 5 yr) and 11 normal subjects (age 36 +/- 5 yr) were studied. The percentage of epithelial cells was assessed by immunocytochemistry using an anti-cytokeratin antibody. The viability of the cells was assessed by trypan blue exclusion. The release of 15-HETE PGE2 and fibronectin was studied in resting cells and after A23187 calcium ionophore stimulation. Epithelial cells always comprised more than 86% of cells recovered, and the viability of epithelial cells was significantly (p < 0.001, Mann-Whitney U test) greater in normal subjects (54 +/- 5%) compared with asthmatic subjects (13 +/- 1%). The release of 15-HETE and fibronectin by resting epithelial cells was significantly greater in asthmatics (p < 0.05, Mann-Whitney U test) than in normal subjects. A23187 significantly (p < 0.05, Wilcoxon W test) increased the release of 15-HETE and fibronectin. There was no significant difference in the release of PGE2 by resting cells from either asthmatics or normal subjects, but challenge with A23187 induced a significant (p < 0.03, Wilcoxon W test) increase in PGE2 from cells of asthmatics but not from cells of normal subjects. This study shows that epithelial cells are activated and less viable in asthma and suggests a role for these cells in asthma.     

Similarities and differences between normal and psychotic subjects in responses to verbal stimuli.

Individuals receive so much verbal stimulation that one would expect verbal response habits to be greatly overlearned, yet clinical data suggests an almost complete breakdown in verbal behavior of psychotics. In the present study, affective ratings, m data, and associative data were gathered from normal and psychotic Ss. Patients, as compared with normals, rate words as affectively better, produce lower m values and more idiosyncratic associations to verbal stimuli. Beneath these apparent differences between the 2 groups there exists a surprisingly substantial core of similarity. This core of similarity suggests that verbal response habits do not break down in psychosis to as large a degree as is generally believed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

P50 suppression among schizophrenia and normal comparison subjects: a methodological analysis

The present report investigated the relationship between P50 suppression and habituation among 20 schizophrenia and 20 normal comparison subjects. Subjects were presented with clicks delivered over headphones in a S1-S2 paradigm (clicks were separated by 500 msec; average intertrial interval was 8 sec). There were 60 total trials; the data were analyzed separately for the first and second 30 trials. The groups did not differ either on the number of usable trials or on the morphology of their P50 responses. Consistent with previous reports, schizophrenia patients demonstrated deficient P50 suppression. The overall suppression effect was not due to a group difference on S1 P50 amplitudes, but was associated with schizophrenia patients having smaller S1-S2 P50 amplitude difference scores than normal comparison subjects. Furthermore, the suppression effect appears to be more pronounced during the first than during the second block of trials. Thus, it may be important to evaluate changes in P50 responses over time among schizophrenia and normal comparison subjects.     

Vestibular-evoked electromyographic responses in soleus: a comparison between click and galvanic stimulation

The aim of this study was to demonstrate, if possible, vestibulospinal reflex responses in soleus using a stimulus known to be capable of exciting vestibular afferents, namely 100-dB (NHL) clicks. We were able to show short-latency electromyographic (EMG) responses after clicks in five of eight normal subjects, and then we compared these responses with those after transmastoid galvanic stimulation (12 normal subjects). Stimulation of the side towards which the head was rotated (i.e. the side facing backwards) with either clicks or the cathode (anode applied to the opposite side) gave an initial excitatory response in soleus, while click or cathodal stimulation of the opposite side (i.e. the side facing forwards) gave an initial inhibitory response. Onset latencies and modulation with changes in postural task were identical for both click- and galvanic-evoked responses. In addition, there was a significant correlation between the amplitudes of the responses in soleus after click and galvanic stimulation (R2=0.72). These similarities suggest that the earliest reflex responses in soleus after clicks and galvanic stimulation may be mediated by a common central pathway. In contrast, there was no correlation between the amplitudes of responses evoked by 100-dB clicks in soleus and those evoked by the same stimulus in the sternocleidomastoid. We conclude that vestibular activation by clicks can evoke reflex responses in lower-limb muscles and these responses have similar characteristics to the earliest responses evoked by galvanic vestibular stimulation.     

Shifting visual attention between objects and locations: Evidence from normal and parietal lesion subjects.

Space- and object-based attention components were examined in neurologically normal and parietal-lesion Ss, who detected a luminance change at 1 of 4 ends of 2 outline rectangles. One rectangle end was precued (75% valid); on invalid-cue trials, the target appeared at the other end of the cued rectangle or at 1 end of the uncued rectangle. For normals, the cost for invalid cues was greater for targets in the uncued rectangle, indicating an object-based component. Both right- and left-hemisphere patients showed costs that were greater for contralesional targets. For right-hemisphere patients, the object cost was equivalent for contralesional and ipsilesional targets, indicating a spatial deficit, whereas the object cost for left-hemisphere patients was larger for contralesional targets, indicating an object deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Airways responses to oral ethanol in normal subjects and in patients with asthma

The effect of oral ethanol on airflow was studied in 5 normal subjects and 5 patients with asthma. On 4 different study days, each subject was asked to drink 40 ml of either water or 20%, 40% or 60% ethanol, and measurements were made of specific airways conductance (sGaw), blood ethanol levels, pulse rate and blood pressure. In some subjects in both groups there was a significant immediate fall in sGaw after drinking ethanol (below 5% confidence limits). Once absorbed, ethanol had a slight bronchodilator effect in 2 normal subjects and in 3 patients with asthma (5% level). Sixty per cent ethanol, when drunk slowly, showed significant bronchodilatation in 4 out of 5 patients with asthma and in one normal subject (5% level) with no acute fall in sGaw. Pulse rate and blood pressure did not change after water, 20% and 40% ethanol in either group, but immediately after 60% ethanol normal subjects showed a significant rise in pulse rate (P less than 0.01) which was not seen in patients with asthma. The immediate changes in sGaw and pulse rate may be due to stimulation of irritant receptors in the upper airways. Ethanol may act directly on bronchial smooth muscle to produce bronchodilatation and may be useful as a bronchodilator when given intravenously.     

Seasonal variations in the composition of urine from normal subjects: a longitudinal study

The volume, pH and composition of 24-h urine samples, collected by 13 healthy male adults, were followed over a period of one year. Significant and systematic variations in urine pH, calcium, phosphate, oxalate, uric acid, potassium and magnesium were observed. A significant but non-sinusoidal variation in sodium excretion was found but there were no significant changes in urinary volume, creatinine or hydroxyproline. Many of the observed changes could be attributed to variations in the pattern of food consumption throughout the year but calcium, phosphate and oxalate were exceptions in that seasonal variations in these parameters appeared to be due to the effects of sunlight (or vitamin D) rather than to the diet.     

CSF cholecystokinin octapeptide in patients with bulimia nervosa and in normal comparison subjects

Cholecystokinin octapeptide (CCK-8) appears to modulate appetitive behavior, and in rodents, anxiety-related behavior. The authors studied CCK-8 in patients with bulimia nervosa. CSF concentrations of CCK-8 were measured in 11 drug-free female patients with DSM-III-R-defined bulimia nervosa and in 16 normal subjects. The bulimic patients had significantly lower levels of CCK-8 than the comparison subjects. CCK-8 concentrations were inversely correlated with scores on the anger-hostility, anxiety, and interpersonal sensitivity subscales of the SCL-90-R. They were not significantly correlated with age, percentage of standardized average body weight, or mean weekly frequency of binge eating or vomiting. The results indicate that central CCK-8 abnormalities may play a role in the pathophysiology of bulimia nervosa.     

The abnormality of normal comparison groups: the identification of psychosis proneness and substance abuse in putatively normal research subjects

OBJECTIVE: Careful assessment of research subjects is important because the inclusion of subjects who manifest psychopathology and significant substance abuse in normal comparison groups will decrease statistical and experimental power. The current study evaluated the usefulness of an MMPI-derived algorithm in identifying tendencies toward psychosis and substance abuse in putatively normal research volunteers. METHOD: Ninety-eight adults who were recruited as normal comparison research subjects completed the MMPI, psychiatric interviews, questionnaires, and selected neuropsychological tests. The MMPI classified 81 presumed normal subjects into four subgroups: 1) not psychosis prone/substance abuse not likely, 2) not psychosis prone/substance abuse likely, 3) psychosis prone/substance abuse not likely, and 4) psychosis prone/substance abuse likely. RESULTS: The MMPI psychosis-prone and substance abuse factors identified significantly distressed and dysfunctional individuals with a relatively high degree of accuracy. CONCLUSIONS: It is becoming increasingly apparent that the cursory self-report screening of normal subjects may result in unacceptable levels of psychopathology in comparison groups. The current results also indicate that an adequate substance abuse evaluation is extremely important and that brief self-report information may be misleading. Empirically derived assessment tools, such as the MMPI, may prove useful in allowing researchers to more accurately define control parameters and group membership.     

Postprandial plasma glucose, insulin, glucagon and triglyceride responses to a standard diet in normal subjects

A uterine pouch was prepared surgically in ewes before mating to study the production and chemical composition of uterine secretions during pregnancy. Pregnancy was established in 6 sheep and in the first 55 days uterine fluid was present in small amounts (less than 5 ml), whereas between 109 days post coitum and 3 days post partum the volume ranged from 90 to 775 ml. The chemical composition of uterine fluid in pregnancy differed from that of plasma especially in respect of its high concentration of total calcium (up to 83.5 mM) and prostaglandin (PG) F-2a (up to 1500 ng/ml). Progesterone was implicated as an important endocrine factor since uterine fluid (188 ml) with a high concentration of total calcium (53-5 mM) and PGF-2a(235ng/ml) was recovered from a non-pregnant sheep treated with progesterone for 115 days.     

Information processing deficits in depression in terms of event-related potentials: in comparison with schizophrenics and normal controls

Information processing deficits characteristic of remitted major depression, which may be a vulnerability marker for the disease, were examined from two aspects by means of visual event-related potentials (ERPs) obtained during simple and discriminative response tasks: 1. To clarify the difference in cognitive dysfunction between both depressives and schizophrenics in remission, we compared the ERPs in remitted depressive patients (n = 11) and remitted schizophrenic patients (n = 9) with those of age, and sex-matched controls (n = 10). 2. To clarify the influence of aging on information processing in remitted depression, ERPs in young remitted depressives (20-46 years old, n = 11) were compared with those in older remitted depressives (52-75 years old, n = 11) in contrast to young (n = 10) and older (n = 11) controls. The remitted schizophrenics showed a retardation in NA and N2 latencies and a reduction in P3 amplitude. However, P1 increased in amplitude exclusively in the remitted depressives. The effect of stimulus discrimination on N1 seen in the controls was absent in both patient groups. The results suggest that the remitted depressives had an attentional deficit in early information processing reflected on P1 and N1 potentials, while the remitted schizophrenics had an extensive cognitive dysfunction reflected on N1, NA, N2, and P3 potentials. Although the effect of stimulus discrimination on N1 was absent in both young and older remitted depressive patients, older patients showed no effects of normal aging on ERPs such as P1 increase or N1 increase during discrimination tasks. Significant interaction effects between diagnosis and aging were found by ANOVA only in the laterality of the P1 amplitude. Older remitted depressives showed an unbalanced right-predominance in P1 amplitude. These results suggest that older remitted depressives had the same early information-processing deficit seen in the young remitted depressives as well as an overactivation over the right hemisphere in the attentional mechanism, irrespective of normal aging.     

Effect of euglycaemic hyperinsulinaemia on gastric emptying and gastrointestinal hormone responses in normal subjects

Several studies have shown that hyperglycaemia slows gastric emptying in normal subjects and patients with diabetes mellitus but whether hyperinsulinaemia per se has an effect remains debatable. In the present study we have assessed the effect of hyperinsulinaemia on gastric emptying of a solid and liquid meal in normal subjects. Ten men were studied three times in random order. After an overnight fast, subjects were infused with 0.9% NaCl on two occasions and on the third with insulin, at 40 mU x m(-2) x min(-1) with 20% glucose simultaneously to maintain euglycaemia. Steady-state glucose infusion rate was ensured before the subjects ate a standard meal of a pancake labelled with 99mTc and milkshake labelled with (111)In-DTPA. Gamma-scintigraphic images were then obtained every 20 min for the next 3 h. There were no significant differences between the mean half-emptying times (T50) of the solid and liquid during the two saline infusions (129.6 +/- 28.5 vs 128.4 +/- 23.8 min for the solid and 25.4 +/- 7.0 vs 34.7 +/- 18.0 min for the liquid, mean +/- SD). Hyperinsulinaemia delayed both solid (mean T50 149.6 +/- 30.7, p = 0.031) and liquid emptying (mean T50 39.8 +/- 13.9, p = 0.042). There were no significant differences in the cholecystokinin and glucagon-like peptide 1 responses to the meal during either saline or insulin infusions. There was a tendency towards a greater insulin response to the meal during the hyperinsulinaemic study. Thus, hyperinsulinaemia delayed emptying of both the solid and liquid components of the meal.     

Inverse relationship between the size of pattern reversal visual evoked potentials from the left brain and the degree of left-hand preference in left-handed normal subjects: importance of the left brain

The relation of the degree of left-hand preference to pattern reversal visual evoked potentials (VEPs) from right and left brain was studied in male left-handers. The degree of the left-hand preference was assessed by the Waterloo Handedness Questionnaire. Visual stimuli consisted of black and white checkerboard patterns generated on a TV screen. VEPs were simultaneously recorded from occipital leads of the right and left hemispheres. The degree of left-hand preference was found to be inversely and significantly related to size of VEPs only from left brain, not from right brain. That is, the conduction time, amplitude, duration, and area of N1-P1 waves linearly decreased as the degree of left-hand preference increased. These results were in accord with the testosterone hypothesis of cerebral lateralization, but not compatible with the right shift theory of handedness. It was concluded that visuomotor control by the left brain would be the main biological correlate of left-hand preference with regard to sensorimotor and cognitive functions.     

Cerebrospinal fluid corticotropin-releasing factor concentrations in patients with anxiety disorders and normal comparison subjects

A simple immunosensor based on a conductivity method was developed for determination of methamphetamine (MA, a stimulant drug) in urine. Anti-MA antibody was immobilized onto the surface of a pair of platinum electrodes. The reaction of MA with the antibody causes a decrease in the conductivity of the anti-MA immobilized layer between the electrodes. A linear relationship was obtained between the conductivity and MA concentration in the range of 1-10 micrograms/ml. The method requires the sample to be rinsed with water on the electrodes after the immunoreaction. This detection system was applied to the determination of MA in urine and proved to be a useful and a simple detection technique of MA in forensic science in comparison with a gas chromatography-mass spectrometry method.     

Plasma membrane phospholipid fatty acid composition of cultured skin fibroblasts from schizophrenic patients: comparison with bipolar patients and normal subjects

Recent studies have found lower red cell plasma membrane contents and composition of the long chain polyunsaturated essential fatty acid derivatives, particularly arachidonic acid and docosahexaenoic acid, in a subgroup of chronic schizophrenic patients. These fatty acids are particularly enriched in the brain. Red blood cell levels of fatty acids are influenced by diet, medications, and other factors. Cell plasma membrane compositions of arachidonic and docosahexaenoic acids were therefore examined in cultured skin fibroblasts from 12 schizophrenic patients, 8 of whom were drug-naive and in a first episode of psychosis, 6 bipolar patients, and 8 normal control subjects. Docosahexaenoic acid as well as total n-3 essential fatty acid contents were significantly lower in cell lines from schizophrenic patients than in cell lines from bipolar patients and normal subjects, with no difference between the latter two groups. Arachidonic acid levels did not differ across the groups. The essential fatty acid profile observed is consistent with deficient delta-4 desaturase activity in schizophrenic patients.