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1.
Hypoxia is a potent activator of the sympathetic nervous system by stimulating arterial chemoreceptors. However, out of 15 laboratory studies on the effects of acute and prolonged hypoxia on catecholamines, 14 failed to show any changes in plasma or urinary noradrenaline and only four studies showed significant increases in plasma or urinary adrenaline. By contrast, six out of eight studies on MSNA showed increased sympathetic nerve activity to the leg. An increased clearance of plasma catecholamines during hypoxia may be a possible explanation. Furthermore, many of the studies had limitations in a number of subjects and catecholamine assays used. Emotional aspects of the study protocols, which could contribute to the increase in adrenaline, was only assessed by sham runs in one chamber study. However, 13 out of 14 reviewed field studies on subjects staying for more than 1 week at high altitude, reported increased plasma or urinary excretion of noradrenaline which may be compatible with increased sympathetic activity. Adrenaline changed to a lesser degree. Out of seven studies on more short-term (4 h to 3 days) exposure to high altitude, only one demonstrated significantly increased plasma noradrenaline. In this study, however, several subjects had been exposed to high altitude less than 1 week before the experiment. In a new study on 12 climbers reported in this paper, a temporary reduction in plasma catecholamines was found 2 days after arrival at 4200 m. There was a steady increase towards normal levels after 1 week. Plasma vasopressin (AVP) increased suggesting a compensatory mechanism. Both plasma noradrenaline and adrenaline were positively correlated with oxygen saturation in these subjects. Thus, in previously unacclimatized subjects, short-term exposure to high altitude does not increase plasma catecholamines, rather plasma levels decreased. In addition to increased clearance, there is some evidence of reduced synthesis of catecholamines during short-term hypoxia. The oxygen sensitivity of tyrosine hydroxylase (TH) activity, may be one possible mechanism. 相似文献
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FJ Setoain S Arroyo F Lome?a J Pavía I Martinez D Fuster R Herranz J Setoain 《Canadian Metallurgical Quarterly》1998,39(9):1001-1005
We report a patient with bilateral independent temporal lobe seizures in whom two [99mTc]HMPAO single photon emission computed tomograph (SPECT) scans were performed during two different seizures. In the first periictal SPECT, [99mTc]HMPAO was injected in the interval between two closely spaced seizures (one localized in the left temporal lobe and the other in the right temporal lobe). SPECT images showed hypoperfusion in the left lateral temporal lobe, hyperperfusion of the left mesial temporal region, and pronounced hyperperfusion in the right anterior temporal lobe. These results suggest both a postictal left temporal SPECT pattern and an ictal right temporal pattern. In the second periictal SPECT, [99mTc]HMPAO was injected immediately after a right temporal lobe seizure and showed right lateral temporal lobe hypoperfusion and right mesial hyperperfusion, suggesting a postictal right temporal SPECT pattern. Interpretation of the periictal SPECT should take into account EEG changes at the time or in the minutes immediately after injection of [99mTc]HMPAO. 相似文献
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AC Rodríguez-Barrionuevo MJ Nú?ez-Castain E Bauzano-Poley MA Rodríguez-Vives 《Canadian Metallurgical Quarterly》1998,27(160):1015-1018
INTRODUCTION AND CLINICAL CASE: We present a male patient which presented distal muscular stiffness, from the first hours of the life. At this time, he also presented episodes of generalized muscular hypertonia with cyanosis and apnoea, started by somato-sensorial stimuli. Those episodes were terminated by passive flexion of the extremities and the head. Later, dream myoclonic jolts appeared. EEG tracings during hypertonic episodes showed an initial artefact potential followed by bursts of rhythmic and repetitive acute potentials in the bilateral fronto-central regions, at a 20-22 Hz frequency, similar to an epileptiform spike-wave burst. The EMG showed a continuous muscular activity, suppressed by rest and the administration of diazepam. Treatment with oral diazepam has been very effective. Now, the patient is four years old, is asymptomatic and continues treatment with oral diazepam. If the dose is decreased, the child starts unstable march, startle response on somatosensory stimuli with falls, and above all nocturnal myoclonia. The patient does not have familiar antecedents of hyperekplexia, even in its minor form. CONCLUSION: Clinical picture suggests us a not familiar form of hyperekplexia. 相似文献
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E Achten 《Canadian Metallurgical Quarterly》1998,8(4):849-862
Seizures, especially epileptic seizures, are among the most common neurologic symptoms. They may occur as a result of fever, hypoglycemia, or acute central nervous system infections. This article discusses how MR imaging and MR spectroscopy contribute to the management of the epileptic patient. 相似文献
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EM Urbańska E Drelewska KK Borowicz P B?aszczak Z Kleinrok SJ Czuczwar 《Canadian Metallurgical Quarterly》1996,103(10):1145-1152
Nitric oxide may be involved in seizure phenomena even though data often seem to be contradictory. This prompted us to study the influence of nitric oxide upon electrically and chemically induced seizures. The effects of nitric oxide synthase inhibitor, NG-nitro-L-arginine (NNA), on pentylenetetrazol-, aminooxyacetic acid-, aminophylline-induced seizures or electroconvulsive shock were evaluated. NNA was applied at 1, 10 and 40 mg/ kg 0.5 and 2.0 h before chemical seizures and at 1 and 40 mg/kg 0.5 and 2.0 h prior to electroconvulsions. The nitric oxide synthase inhibitor (up to 40 mg/ kg) did not affect the susceptibility of mice to pentylenetetrazol, amino-oxyacetic acid or electroconvulsions. However, NNA significantly enhanced the convulsive properties of aminophylline when applied at 40 mg/kg, 0.5 h before the test. The CD50 value for aminophylline-induced clonus and tonus/ mortality was decreased from 233 to 191 and from 242 to 212 mg/kg, respectively. However, this pretreatment also led to a significant increase in the plasma levels of theophylline. Our results suggest that differential effects of NNA on chemically-induced convulsions might in some cases be associated with a pharmacokinetic interaction. 相似文献
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P53 immunohistochemistry in astrocytic tumors has usually been evaluated by the percentage of positive cells. However, in this study we analyzed the P53 immunopositive cells by their patterns of distribution. Formalin-fixed and paraffin-embedded sections from 38 patients with astrocytic tumors were examined. The distribution pattern of P53 immunostaining cells was divided into 3 types: negative, locally scattered, and diffuse clustering. There were 2 positive stains in 5 astrocytomas (40%), 12 positive in 24 anaplastic astrocytomas (50%), and 7 positive in 9 glioblastoma multiformes (78%). In astrocytomas, the positive cells were locally scattered. In anaplastic astrocytoma and GBM, the positive cells appeared locally scattered or as diffuse clustering. For the variant immunoreactive expression, the mean ages for patients with negative, locally scattered and diffusely clustered P53 immunostaining were as follows: 51.4, 52.6, and 28.4 years (P < 0.01), respectively. In anaplastic astrocytoma and GBM, the diffusely clustered pattern was more common in younger patients, whereas elderly patients in same groups tended to have few or no P53 immunopositive cells. Thus, our results implicate that clonal expansion of P53 immunopositive cells is associated with brain tumor progression. 相似文献
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Mendenhall's syndrome, characterized by familial insulin resistant diabetes, pineal hyperplasia and multiple somatic abnormalities, is associated with defects involving the alpha-subunit of the insulin receptor. The associated insulin-resistant diabetes is extremely difficult to treat; insulin is required in very large doses to control hyperglycaemia and oral hypoglycaemic agents are ineffective. We report a case of severe, prolonged hypoglycaemia that occurred in a 24-year-old patient with Mendenhall's syndrome following therapy with glibenclamide. He had glibenclamide 10 mg daily for 1 week following which he was admitted to hospital in hypoglycaemic coma with blood glucose levels < 1.0 mmol/l. This subject had undergone hypophysectomy at the age of 11 years. Prior to pituitary ablation, oral hypoglycaemic agents did not improve glycaemic control. Thus, previous hypophysectomy in this patient appears to have made it possible for glibenclamide to exert its hypoglycaemic effect. The occurrence of hypoglycaemia in this patient suggests alternative mechanisms for insulin action in conditions characterized by severe insulin resistance due to insulin receptor defects. 相似文献
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B Basnyat 《Canadian Metallurgical Quarterly》1998,5(4):221-222
In Trinity Hospital, a district hospital in the south of Malawi, over a period of 4 years 60 patients were admitted following injury by crocodiles. All patients were treated by extensive surgical cleaning and debridement, anti-tetanus treatment and broad spectrum antibiotics. Twenty-four patients (40%) had serious injuries resulting in permanent deformity. Only one patient died from sepsis. 相似文献
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L Caminal Montero L Trapiella Martínez A González Marroquín C Fernández Fernández A Sanz Rubiales 《Canadian Metallurgical Quarterly》1997,197(5):383-384
A case of primary Nocardia otitidiscaviarum infection of a skin wound over an open fracture in a previously healthy adult who suffered multiple trauma in a car accident is reported. The organism was identified in cultures of pus specimens from the infected wound. The case demonstrated the difficulties of testing susceptibility of nocardiae in vitro and the necessity of prolonged antibiotic treatment. The prevalence of nocardial infections is underestimated, highlighting the need for adequate documentation of such infections and compilation of the information by public health authorities. 相似文献
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Carnitine concentrations in CSF, serum, and urine in normal febrile children and children with meningitis, neurologic disorders, and dehydration were studied. Carnitine levels in CSF were 1/10 compared with serum in normal febrile children. These levels increased two- to three-fold in the pathologic conditions studied. Since damage to the blood-brain barrier occurs in these conditions, higher blood-brain barrier permeability might explain CNS carnitine accumulation. 相似文献
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Electrodermal arousal was studied at rest and during repetitive stimulation in chronic schizophrenics who were rated at either extreme of the Montrose Rating scale (MRS), either receiving a phenothiazine or no drugs, and in a control normal sample. Resting base level was significantly higher among Hi than Lo MRS, and among Nondrug than Drug patients: no patient sample was reliably below Control level. Nondrug patients showed no impairment in tonic arousal relative to Controls, even when such patients showed impaired phasic response (though the drug was seemingly associated with diminished tonic response). Considerable independence was demonstrated between phasic and tonic electrodermal functions. Unlike Controls (or Drug patients), Nondrug patients showed a general heightening of electrodermal arousal during repetitive innocuous stimulation. A vigilance hypothesis was offered suggesting that sensitivity to the general demands of the environment remains high among chronic patients, even where there may be a reduction in the input of specific items of information from that environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The frequent coexistence of anti-Ro and anti-La autoantibodies is well described, however, there is little evidence of sequential development of these two autoantibodies. We report a case of typical Sjogren's syndrome with high titer anti-Ro antibodies, who subsequently developed anti-La antibodies later in the course. This case suggests that the anti-La antibodies may actually follow the anti-Ro antibodies in some cases as hypothesized in the concept of linked set of autoantibodies, analogous to development of anti-Sm in certain anti-nRNP antibody positive SLE patients and animal models. 相似文献
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H Yamashiro 《Canadian Metallurgical Quarterly》1977,47(5):472-473
A technique is presented to eliminate the residual gradient more completely after removing the main pulmonary band at the time of primary repair of ventricular septal defect. The band and underlying pulmonary artery are circumferentially excised, except for a small posterior part, and pulmonary artery is reanastomosed. 相似文献
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OBJECTIVE: To determine the knowledge of rubella immune status among practicing obstetrician-gynecologists in the United States and of rubella immunity policies covering healthcare workers in the obstetric-care office setting. DESIGN: Mailed survey questionnaire, August through December 1994. SETTING: Physicians from multiple-practice sites including private office, public institution, university or teaching hospital, and closed panel health maintenance organization settings. PARTICIPANTS: 3,302 practicing obstetrician-gynecologists, chosen by a systematic random sample from the AMA national physician database. MAIN OUTCOME MEASURES: Participants were defined as rubella immune if they reported knowledge of prior rubella vaccination or positive antibody titer. Knowledge of a policy for documenting rubella immunity among employees in the office-based practice setting also was assessed. RESULTS: Questionnaires were returned from 50% (1,666) of the 3,302 surveyed, and 96% (1,599) were evaluable. Approximately 20% (304/1,599) of the responding obstetrician-gynecologists did not have knowledge of documented rubella immunity, and the majority of office-based practices did not require documentation of rubella immunity in the following groups: physicians, 66% (723/1,094); office nurses, 62% (666/1,070); and other office staff, 69% (728/1,063). Sixty-two percent (993/1,599) of responding physicians had individual rubella serologies performed, with 916 known to be positive, 53 reported negative, and 24 reported unknown. Fifty-seven percent (918/1,599) reported receiving monovalent rubella vaccine or trivalent measles-mumps-rubella vaccine. Multiple logistic regression analysis revealed the following to be independent predictors of positive immune status among respondents: female gender (odds ratio [OR], 2.4; 95% confidence interval [CI95], 1.8-3.1), medical school graduation since 1980 (OR, 2.6; CI95, 2.0-3.3), providing obstetric or fertility services (OR, 1.5; CI95, 1.2-1.9), and group practice setting (> or = 5 physicians; OR, 1.2; CI95, 1.1-1.4). CONCLUSIONS: Nationally, nearly one of every five practicing obstetricians may not have documented rubella immunity, and the majority of office-based practices have no system for assuring such immunity. Rubella immunity should extend beyond the hospital setting, with consideration for requiring rubella immunity as a condition for employment. Methods for effective implementation and documentation of current guidelines need to be addressed, particularly in the office setting. 相似文献
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F Gilliam S Bowling E Bilir J Thomas E Faught R Morawetz C Palmer J Hugg R Kuzniecky 《Canadian Metallurgical Quarterly》1997,38(12):1315-1320
PURPOSE: Magnetic resonance imaging, interictal scalp EEG, and ictal scalp EEG each have been shown to localize the primary epileptic region in most patients with mesial-basal temporal lobe epilepsy (MBTLE), but the association of surgical outcome and pathology with each combination of these test results is not known. METHODS: We reviewed the MRI, interictal scalp EEG, and ictal scalp EEG results of 90 consecutive patients with MBTLE. Twelve patients were excluded from the analysis because inconclusive bitemporal intracranial EEG results precluded anterior temporal lobectomy (ATL); none had concordant MRI and interictal scalp EEG results. We compared all combinations of presurgical MRI, interictal EEG, and ictal EEG results to seizure outcome and tissue pathology in the 78 patients who underwent an ATL. RESULTS: Forty-eight (61%) patients had concordant lateralized MRI and interictal EEG temporal lobe abnormalities, with no discordant ictal EEG results; 77% of these patients were seizure-free after ATL. Concordance of MRI and interictal EEG abnormalities correlated with seizure cessation (p < 0.05), compared to all combinations with discordant or nonlateralizing MRI and interictal EEG results. Mesial temporal sclerosis (MTS) was confirmed pathologically in about 80% of both groups (p = 0.5). Outcome in patients with concordant MRI and ictal EEG with nonlateralizing interictal EEG was significantly worse than combinations with concordant MRI and interictal EEG (p < 0.02). CONCLUSIONS: Compared to other combinations of test results, concordance of MRI and interictal EEG is most closely associated with surgical outcome in MBTLE. However, most selected patients have pathologic confirmation of MTS regardless of test results or outcome. This information may be useful for planning the presurgical evaluation of patients with medically intractable MBTLE. 相似文献
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To the authors' knowledge, this case is unique to the emergency medicine literature. Although testicular infarction from epididymitis is rare, it should be considered as a complication of severe or unresolving epididymitis. These patients should be placed on broad spectrum antibiotics, i.e., quinolones; color flow Doppler of the testes should be obtained; and urologic consultation should be considered for possible admission and surgical exploration. 相似文献