Arousal response to electrical stimulation of the cerebral cortex in cats.

Questions the belief that the arousal response produced by stimulation at various sites in the cortex is due to direct stimulation of the cortical component of a central arousal system. 3 observations of 9 female and 2 male cats were not consistent with this interpretation. Fractionation of the arousal response, subtotal parts of the reaction being produced by varying the intensity of cortical stimulation, occurred only when the S was in the resting state, and the arousal response habituated during repeated cortical stimulation. These observations on the arousal response to cortical stimulation were duplicated closely by the arousal response to an auditory stimulus. In agreement with a 1967 study by H. Ursin, K. Wester, and R. Ursin, it is suggested that the arousal response to stimulation of the cortex is a reflex to a sensory experience created by cortical stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Denial of threat and emotional response to impending painful stimulation.

Significant negative correlations were obtained between scores on Byrne's Repression-Sensitization (R-S) scale and several indices of electrodermal activity in a paradigm in which Ss anticipated the presentation of strong electric shock. These results support the hypothesis that Ss who receive low scores on the R-S scale (repressers) exhibit greater disturbance than do those who receive high scores (sensitizers). Repressers reported a stronger tendency to avoid thinking about impending shock (suppression) than did sensitizers. This reported tendency to use suppression techniques was directly and significantly related to basal skin conductance, non-specific GSR activity, magnitude of anticipatory GSR activity, and the number of sec. by which this activity preceded shock. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of electrical stimulation or local anesthesia of the rabbit's hypothalamus on the acute phase response

The effects of electrical stimulation of the rostral hypothalamic region on the acute phase response (APR) were examined in rabbits. As indicators of APR, we measured changes in the plasma concentrations of iron, zinc, copper, and fibrinogen and changes in the red and white blood cell counts. Electrical stimulation of the rostral hypothalamic region near the preoptic and anterior hypothalamic region did not induce any aspect of the APR. However, stimulation near the anteroventral portion of the third ventricle (AV3V) induced responses that were, in part, opposite to those observed in the APR: an increase in the plasma concentration of zinc and a decrease in the circulating leukocyte count. Microinjections of procaine into the brain regions near the AV3V did not induce any changes in the plasma levels of trace metals and fibrinogen but increased the circulating leukocyte count. These results suggest that nonspecific stimulation or inhibition of the rostral hypothalamic region does not induce APR.     

The repression-sensitization dimension in relation to impeding painful stimulation.

Attempted to replicate previous findings of differences between self-report and physiological indices of disturbance in repressors and sensitizers placed in threatening situations. 8 male and 52 female undergraduates chosen on the basis of their score on Byrne's Repression-Sensitization scale were divided into 4 groups of 15 Ss each. Ss in the shock condition were given a number of painful electric shocks; the control Ss were given similar but painless vibratory stimulation. Indices of electrodermal activity were recorded, and the A-State scale of the State-Trait Anxiety Inventory was administered. Results indicate that repressors admit to less anxiety on the self-report measure while producing more physiological reactivity to threat of shock. No such differences were obtained in the control condition. Results are discussed in light of repression-sensitization theory. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peculiarity of soleus motor potentials evoked by transcranial magnetic stimulation and electrical stimulation of tibial nerve

Fas (Apo-1/CD95) ligand (FasL) is a cytotoxic molecule used by T lymphocytes and natural killer cells for target-cell killing and by nonmalignant and malignant cells in the suppression of immune responses. In this study, FasL expression in B- and T-cell non-Hodgkin's lymphomas was investigated by paraffin immunohistochemical analysis. FasL expression was found to be weak in nonaggressive lymphomas (chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytoid lymphoma, Grade 1 follicular center cell lymphoma) and mantle cell lymphoma but strong in aggressive B-cell lymphomas (diffuse large B-cell lymphoma, Burkitt's-lymphoma). Precursor B-lymphoblastic lymphomas were more heterogeneous, with expression varying from weak to strong. In T-cell lymphomas (anaplastic large-cell lymphoma; peripheral T-cell lymphoma, unspecified), strong FasL expression was observed. Apparently, FasL expression is not limited to neoplasms derived from T cells or natural killer cells, and it might play a supporting role in the progression of non-Hodgkin's lymphomas.     

Managing equinus in children with cerebral palsy: electrical stimulation to strengthen the triceps surae muscle

A new therapeutic proposal for the management of equinus in children with cerebral palsy is to strengthen the calf muscles instead of weakening them surgically. Prior research indicates that in children with cerebral palsy the triceps surae muscle is weak and needs strengthening. Neuromuscular electrical stimulation (NMES) was used as an adjunct to physical therapy. A portable NMES unit with a hand-held remote switch stimulated an active muscle gait cycle. Results are discussed for four children, who showed improved gait, balance, posture, active and passive ankle range of motion, and foot alignment. The toe walkers became plantigrade and the equinovalgus posture of the foot decreased. Spasticity did not increase.     

Sound stimulation increases the cerebral glucose:oxygen quotient in the fetal sheep

We sought to determine the cerebral metabolic fate of glucose during sound stimulation in near-term fetal sheep. Blood oxygen content was significantly decreased by 6-7% during sound stimulation. The cerebral glucose:oxygen quotient increased from 0.88 +/- 0.08 to 1.13 +/- 0.12 (mean +/- S.E.M., P < 0.01). This is consistent with the phenomenon of stimulated glycolysis which has been shown to increase brain lactate concentration in other models.     

Dose for minimal sympathetic response to a painful stimulation for alphaxolone and thiopentone in man (author's transl)

The dose that prevents the sympathetic response to a painful stimulation has been determined for alphaxolone and thiopentone (DRSM). The stimulation was the tracheal intubation and the sympathetic response has been evaluated as the percentual change of heart rate from the basal level. The DRSM has been determined as the dose that assures no percentual change of H.R. after intubation. The alphaxolone showed a DRSM very low (0.489) on the contrary the dose of thiopentone required to obtain no sympathetic response is high (7.776).     

A simple method for recording motor evoked potentials of lingual muscles to transcranial magnetic and peripheral electrical stimulation

A 1.8 kg chromosomally normal child was suspected antenatally to have a cloacal anomaly and oligohydramnios. Both parents had a chromosome 9 inversion (inv [9] [p11 q13]). Postnatal study showed a high confluence of the urinary, genital and intestinal tracts. Because of prematurity, a right colostomy was performed on a short colon, but the genitourinary tract was not drained. Poor weight gain, urinary tract infection and septicaemia led to a one-stage reconstruction at 5 months of age and a weight of 3.2 kg. Follow-up although short at 15 months, is encouragingly suggestive of urinary and faecal continence. The vagina is patent. This paper considers concepts in cloacal management and submits for evaluation an alternative surgical plan to the presently almost exclusively accepted posterior sagittal approach of Pe?a and De Vries.     

Effect of neuronal NO synthase inhibition on the cerebral vasodilatory response to somatosensory stimulation

Whether nitric oxide (NO) mediates--or not--the local cerebral blood flow (CBF) increases occurring during functional brain activation is still a controversial issue. In the present study, we sought to determine whether neuronal NO synthase is involved in the cerebrovascular response to activation of the trigeminal pathway in the rat. Local CBF was measured using the autoradiographic [14C]iodoantipyrine technique in control alpha-chloralose anesthetized rats and 30 min following administration of 7-nitroindazole (7-NI), an inhibitor of the neuronal NO synthase. Unilateral whiskers stroking increased local CBF in all six regions of the trigeminal pathway. Under 7-NI, CBF was slightly decreased and the vasodilatatory response to whisker stimulation was unaltered in the four trigeminal nuclei studied. In contrast, no significant vasodilatation was noted in the ventral posteromedial thalamic nucleus and somatosensory cortex. These results suggest that the neuronal NO synthase mediates the hyperemia associated with somatosensory activation in second order relay stations but not in the site of termination of primary afferents.     

Short and long latency cortical potentials evoked by electrical stimulation of the oesophageal mucosa in normal alert humans

BACKGROUND: The type of remodeling of the human femoral artery (enlargement or shrinkage) is related to the percentage luminal stenosis. OBJECTIVE: To assess how local changes in vessel size, together with plaque load, determine luminal narrowing in atherosclerotic human coronary arteries. METHODS: We obtained 576 segments of 28 coronary arteries from 10 patients who had died from noncardiac causes. The lumen area and area circumscribed by the internal elastic lamina (IEL) area, a measure of local vessel size in each histologic cross-section were measured, and the mean lumen diameter and mean IEL diameter were calculated. To correct for arterial tapering, expected reference diameter values were calculated at the same location using linear regression of all data points along the artery. The IEL diameter and lumen diameter were expressed as percentages of the calculated IEL diameter and lumen diameter at the same location (percentage lumen diameter stenosis and relative IEL diameter, respectively). RESULTS: We found a negative relation between the relative IEL diameter and the percentage lumen diameter stenosis. On average, a narrower than expected lumen diameter was accompanied by a smaller than expected IEL diameter. A larger than expected lumen diameter was accompanied by a larger than expected IEL diameter. This relation was found for the left anterior descending, circumflex, and right coronary arteries (y = -0.60x + 105.33, r = 0.48; y = -0.45x + 100.69, r = 0.84; and y = -0.39x + 101.84, r = 0.61, respectively, all P < 0.05). CONCLUSIONS: Local luminal narrowing was correlated with a decrease in vessel size. Local remodeling of the artery is one of the determinants of luminal narrowing in the atherosclerotic human coronary artery.     

Muscle atrophy is prevented in patients with acute spinal cord injury using functional electrical stimulation

Severe muscle atrophy occurs rapidly following traumatic spinal cord injury (SCI). Previous research shows that neuromuscular or 'functional' electrical stimulation (FES), particularly FES-cycle ergometry (FES-CE) can cause muscle hypertrophy in individuals with chronic SCI (> 1 year post-injury). However, the modest degree of hypertrophy in these already atrophied muscles has lessened earlier hopes that FES therapy would reduce secondary impairments of SCI. It is not known whether FES treatments are effective when used to prevent, rather than reverse, muscle atrophy in individuals with acute SCI. This study explored whether unloaded isometric FES contractions (FES-IC) or FES-CE decreased subsequent muscle atrophy in individual with acute SCI (< 3 months post-injury). Twenty-six subjects, 14-15 weeks post-traumatic SCI, were assigned to control, FES-IC, or FES-CE against progessively increasing resistance. Subjects were involved in the study for 3 or 6 months. Total body lean body mass (TB-LBM), lower limb lean body mass (LL-LBM), and gluteal lean body mass (G-LBM) were determined before the study, and at 3 and 6 months using dual energy X-ray absorptiometry (DEXA). Controls lost an average of 6.1%, 10.1%, 12.4%, after 3 months and 9.5%, 21.4%, 26.8% after 6 months in TB-LBM, LL-LBM and G-LBM respectively. Subjects in the FES-IC group consistently lost less lean body mass than controls, however, only 6 month G-LBM loss was significantly attenuated in this group relative to the controls. In the FES-CE group, LL-LBM and G-LBM loss were prevented at both 3 and 6 months, and TB-LBM loss was prevented at 6 months. In addition, FES-CE significantly increased G-LBM and LL-LBM after 6 months of training relative to pre-training levels. Within the control group, there was no significant relationship between LL-LBM loss (3 and 6 months) and the number of days between injury and baseline measurement. In summary, this study shows that FES-CE, but not FES-IC, training prevents muscle atrophy in acute SCI after 3 months of training, and causes significant hypertrophy after 6 months. The magnitude of differences in regionalized LBM between controls and FES-CE subject raises hopes that such treatment may indeed be beneficial in preventing secondary impairments of SCI if employed before extensive post-injury atrophy occurs.     

Individual differences in self-control behaviors and tolerance of painful stimulation.

Studied the relation between Ss' general repertoire of self-control behaviors and their ability to tolerate a cold pressor. In Exp I, with 40 undergraduate Ss, it was found that Ss who were instructed to think of a pleasant event while exposed to a cold pain tolerated that pain longer than a control group, thus replicating previous findings. In Exp II, with 54 undergraduate Ss, one experimental group was required to spend 5 min in self-planning of strategies to cope with the upcoming pain, and a 2nd group was merely informed on the effectiveness of self-control methods in coping with pain. Both groups did not show longer durations than Ss in a control group who were not encouraged to employ their own self-control methods. High self-control (HSC) Ss across the various treatment conditions consistently tolerated the cold pressor longer than low self-control Ss. HSC Ss also reported using self-control methods more often and more effectively while exposed to the cold pressor. The 2 self-control groups did not differ in their ratings of pain intensity. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Corticospinal direct response to transcranial magnetic stimulation in humans

The corticospinal motor evoked potential (MEP) response to transcranial magnetic stimulation of the motor cortex was investigated in comparison with the direct (D) response to electrical stimulation of the exposed motor cortex from the spinal epidural space in 7 neurologically normal patients during brain tumor surgery. The D response during operation was obtained by transcranial magnetic stimulation of the scalp over the areas of the cerebral motor cortex, the hand or arm areas. The magnetic induced D response showed a conduction velocity of 50.5-72.7 m/sec and was resistant to anesthesia and unaffected by muscle relaxants and tolerant to high frequency (500 Hz) paired magnetic stimulus, and the latencies of magnetic MEPs corresponded to those with direct electrical stimulation. Thus, recordings of the D response by transcranial magnetic stimulation are useful for not only identifying the location of the motor cortex during intracranial surgery but also for non-invasive recording of pyramidal tract activity during extracranial surgery under general anesthesia.     

Electrocortical and behavioral responses produced by acute electrical stimulation of the human centromedian thalamic nucleus

It is now apparent that HIV infection leads to a gradual collapse of a complex system of lymphoid tissue. This collapse tends to be associated with a change in virus tropism from macrophages to T lymphocytes, and a change in phenotype from nonsyncytium inducing (NSI) to syncytium inducing (SI). An experimental system is required to study the role of this change in HIV pathogenesis in lymphoid tissue. Here we describe such a system. Histocultures of human lymphoid tissue preserve their general cytoarchitecture, including a network of follicular dendritic cells (FDCs). Histocultures of tonsils, adenoids, or lymph nodes support productive infection with various laboratory and primary isolates of HIV-1 of different tropism and phenotype and exhibit isolate-dependent CD4+ T lymphocyte depletion. A strong correlation between the extent of CD4+ T cell depletion and the SI/NSI phenotype of the isolates is demonstrated. AZT was used as a model drug to inhibit viral replication and CD4+ T cell depletion in lymphoid histocultures. HIV pathogenesis and the effect of antivirals can now be studied in human lymphoid tissue under controlled conditions in vitro.     

Posttrial electrical stimulation of the dorsal hippocampus facilitates acquisition of the nictitating membrane response.

In 2 experiments, New Zealand albino rabbits with electrodes implanted in the dorsal hippocampus (DHC) were trained on the acquisition of the nictitating membrane response (NMR). Posttrial application of subseizure-level electrical stimulation within a single session resulted in facilitation of NMR conditioning. In contrast, seizure-level stimulation within a single session and subseizure-level stimulation in multiple sessions had no facilitatory or deleterious effects on NMR conditioning. It is suggested that DHC stimulation facilitates conditioning by activation of midbrain and cerebellar circuits. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of patterned stimulation for use in surface functional electrical stimulation systems

From a gerontological point of view, social work which accompanies care processes is absolutely necessary. The social production of care depends crucially on an appropriate attention toward the fitting between informal and formal help systems. Social work can support these fitting processes both on a firm level and on a neutral level. Some specific attributes of social work with elder care-dependant living in their private homes are discussed, such as threatening, difficult or ashaming aspects, as well as the necessity of all involved persons agreeing in the developed help-planning process. Practice research and Social science perspectives are discussed as appropriate reference system for life-world orientated social work with informal caregiving arrangements. Concerning the support of informal caregivers as an important example of ambulant social work with elder people, some dimensions of theoretical and practical professionality are proposed.