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Biomedical subjects

O Myking

Publications and source records attributed to O Myking.

At least 19 recordsLinked to original sources
PubMed2002

Effect of light exercise on renal hemodynamics in patients with hypertension and chronic renal disease.

OBJECTIVE: Increased physical activity is followed by a stimulation of the sympathetic nervous system and this effect is probably more pronounced in patients with chronic renal failure and hypertension than in healthy controls. The role of sustained exercise in hypertensive patients with chronic renal failure, with and without antihypertensive therapy, is unclear, as is hormonal regulation of the renal hemodynamics. We hypothesized that prolonged low-intensity bicycle exercise would have a greater effect in patients with chronic renal failure than in controls, and that antihypertensive treatment would ameliorate these effects. MATERIAL AND METHODS: Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), mean arterial blood pressure (MAP), norepinephrine (NE) and atrial natriuretic peptide (ANP) were measured in the upright position before and during low-intensity exercise for 2 h in healthy controls (n = 8) and in hypertensive patients with moderately reduced renal function who were not taking antihypertensives (n = 7) or who were receiving treatment with captopril (n = 10), enalapril (n = 6) or verapamil (n = 9). RESULTS: GFR tended to decrease and ERPF decreased significantly in healthy individuals when exercise duration was prolonged from 1 to 2 h. An earlier decline in GFR and ERPF was seen in the renal failure patients compared with the controls. Filtration fraction (FF) increased during exercise in all groups except the group taking enalapril. MAP increased in the captopril group during exercise but was unchanged in the other groups. Treatment with captopril produced a more pronounced and earlier fall in exercise-induced GFR than in untreated controls, while verapamil treatment completely blunted the decline in GFR, with a concomitant increase in plasma ANP. No significant changes were seen in plasma NE levels, but urinary NE excretion increased in controls and captopril-treated patients during exercise. CONCLUSIONS: The results suggest that prolonged low-intensity exercise has a substantially greater effect on renal hemodynamics in hypertensive renal failure patients than in healthy controls, with negligible changes in plasma NE levels. Verapamil treatment seems to ameliorate the renal effects of exercise on GFR in these patients, and this may in part be mediated via a stimulatory effect on ANP.

Adult↗
PubMed2001

Role of endothelin in the circulatory changes associated with small bowel strangulation obstruction in pigs: effects of the endothelin receptor antagonist bosentan.

BACKGROUND: We have previously shown that experimental strangulation obstruction leads to increased release and concentration of endothelin-1 (ET-1) in venous blood from the strangulated bowel loop. The present study focuses on the microcirculatory effects of the released ET-1 in strangulation obstruction. METHODS: In anesthetized pigs strangulation obstruction was induced by increasing pressure in a baby pressure gasket placed around a loop of ileum until venous pressure reached 45 mm Hg. The pigs were randomly allocated into two groups. The nonselective ET(A)/ET(B) antagonist bosentan was administered intravenously (5 mg kg(-1)) to eight pigs (bosentan group) 30 min before strangulation, which was maintained for 90 min. Another eight pigs were treated in same manner except for the bosentan injection (control group). RESULTS: The concentration of ET in arterial and intestinal venous blood increased markedly after intravenous administration of bosentan. Intravenous infusion of bosentan was followed by a reduction in systemic arterial blood pressure. Bosentan reduced vascular resistance and increased blood flow in the normal intestinal mucosa. It also reduced muscularis blood flow in the beginning of the experiment. In strangulated small bowel bosentan inhibited the increase in vascular resistance usually caused by strangulation obstruction. Muscularis blood flow in strangulated small bowel was not affected by bosentan. CONCLUSION: Endothelin is involved in the normal regulation of arterial blood pressure. The increase in vascular resistance associated with strangulation obstruction is caused mainly by locally released endothelin.

Animals↗
PubMed2001

Sympathetic nervous system overactivity in hypertensive patients with chronic renal failure--role of upright body position.

OBJECTIVE: The renal functional consequences of an activated sympathetic nervous system and plasma atrial natriuretic hormone (ANP) in various renal diseases are not well described. We hypothesize that norepinephrine (NE) and ANP have antagonizing effects on renal hemodynamics in diseased kidneys. MATERIAL AND METHODS: Plasma NE, ANP. glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and mean arterial pressure (MAP) were measured in the upright position in healthy controls (n = 9) and hypertensive patients with reduced GFR (n =11). The same parameters were compared between healthy controls (n = 6) and hypertensive patients with reduced GFR (n = 6) in upright and supine positions. RESULTS: Upright plasma NE and ANP were significantly elevated in the patients compared with the controls (4.4 +/- 0.4 vs 2.1 +/- 0.2 nmol/l (p < 0.001) and 1.3.5 +/- 2.1 vs 6.9 +/- 1.0 nmol/l (p < 0.01) respectively). With change from upright to supine position plasma NE decreased in the controls (2.2 +/- 0.3 vs 1.7 +/- 0.3 nmol/l) (p < 0.01) and patients (3.8 +/- 0.4 vs 2.6 +/- 0.4) (p < 0.01). Supine ANP increased in controls (5.5 +/- 1.0 vs 8.3 +/- 1.1) (p < 0.01) but not in patients (14.3 +/- 3.8 vs 16.1 +/- 3.8 nmol/l) (p > 0.10). Plasma NE correlated positively with MAP (p < 0.001) and negatively with GFR (p < 0.01) in the upright but not supine position. A positive correlation between NE and ANP was observed in upright (p < 0.001) but not in supine position. ANP correlated negatively with GFR in the upright (p < 0.01) but not supine position. No position dependent changes were seen in GFR and ERPF, but supine filtration fraction (FF) increased insignificantly in the patient group (0.23 +/- 0.02 vs 0.24 +/- 0.02) (p < 0.05). CONCLUSION: Hypertensive patients with reduced GFR have elevated levels of plasma NE and ANP in the upright body position. When the upright and supine positions are compared, plasma NE declines in the supine position in controls and hypertensive renal failure patients. and plasma ANP levels are elevated only in the upright position in hypertensive renal failure patients where the sympathetic nervous system is activated. A significant positive relationship between plasma NE and ANP was observed only in the upright position. The upright body position seems superior to recumbency in the characterization of these hormonal changes in hypertensive chronic renal failure patients.

Atrial Natriuretic Factor↗
PubMed2000

The value of ultrasonography in predicting autoimmune thyroid disease.

Ultrasonography (US) may demonstrate a diffuse reduction in thyroid echogenicity (low-amplitude echoes) in autoimmune thyroid disease (AITD), which includes chronic lymphocytic thyroiditis and Graves' disease, as well as in subacute thyroiditis. The reported occurrence of this finding in AITD varies from 19% to 95%. To assess the validity of diffuse reduction in thyroid echogenicity as a predictor of AITD, 3,077 patients referred for US of the thyroid were examined prospectively with regard to reduced versus normal thyroid echogenicity. The most frequent reasons for referral were goiter, thyroid dysfunction, neck discomfort, and/or difficulty in swallowing. Ultrasonography demonstrated diffuse reduction in thyroid echogenicity in 485 patients. Of these, 452 patients had available records of fine-needle aspiration biopsy (FNAB), and were included in the study. From the remaining patients, with normal thyroid echogenicity, 100 consecutive patients were selected as controls. In 411 of the 452 study patients (90.9%) there was at least one laboratory finding consistent with possible AITD: cytology indicating lymphocytic thyroiditis, 287 of 363 patients (79.1%) with diagnostic specimens; elevated levels of peroxidase antibodies (TPOAb), 225 of 337 (66.8%); elevated thyrotropin (TSH) levels, 290 of 450 (64.4%); or low TSH levels, 79 of 450 (17.6%). The final diagnosis was: chronic autoimmune (Hashimoto's) thyroiditis in 352 patients; Graves' disease in 47 patients; subacute (granulomatous) thyroiditis in 7 patients; toxic nodular goiter in 3 patients; and toxic adenoma in 2 patients. In the remaining 41 patients, those without laboratory results consistent with AITD, the final diagnosis was colloid goiter in 37 and thyroid cancer in 4 patients. In the 100 controls, laboratory results were consistent with possible AITD in 14 patients: elevated TPOAb levels in 5 of 49 patients with retrieved antibody results; lymphocytic thyroiditis in 2 patients; elevated TSH levels in 2 patients; and low TSH levels in 2 patients. In these controls, the final diagnosis was: chronic autoimmune thyroiditis in 7; toxic nodular goiter in 6 patients, and toxic adenoma in 1 patient. The corresponding positive and negative predictive values of reduced thyroid echogenicity as an indicator of AITD were 399 of 452 (88.3% [95% CI, 85% to 91%]), and 93 of 100 (93.0% [95% CI, 88% to 98%]), respectively. Thus, diffuse reduction in thyroid echogenicity was a valid predictor of AITD.

Adolescent↗
PubMed1999

Similar central hemodynamics in salt-sensitive and salt-resistant hypertensive patients.

Salt may be involved in the pathogenesis of essential hypertension but no agreement has been reached on how salt might exert its blood pressure control. One reason for the conflicting results could be differences in response to changes in salt intake--i.e. between salt-sensitive and salt-resistant subjects. Hypertension reflects a hemodynamic disturbance: mainly an increase in total peripheral resistance. In order to determine whether central hemodynamics is different in salt-sensitive and salt-resistant essential hypertension, a study was carried out on 37 patients aged 31-63 years with mean casual blood pressure 165/104 mmHg. Based on an increase in ambulatory 24-h mean blood pressure of > or = 10% after one week of dietary salt loading (260 mmol NaCl/24 h) following a one-week salt depletion period (60 mmol NaCl/24 h), 7 patients (19%) were classified as salt sensitive and 30 patients (81%) as salt resistant. Before the salt-sensitivity test, while patients were on their habitual salt intake (160 mmol NaCl/24 h), central hemodynamics (intra-arterial pressure, cardiac output by dye dilution, heart rate by electrocardiogram, and total peripheral resistance) was examined at rest and during bicycle exercise. None of the central hemodynamic variables were different between the two groups, despite a marked difference in blood pressure response to one week of salt loading between the salt-sensitive and the salt-resistant groups (27/9 mmHg vs -2/1 mmHg). Furthermore, no statistically significant differences were observed in neurohumoral variables or echocardiographic indices of left ventricular dimensions between the two groups. Owing to the invasive hemodynamic procedure, central hemodynamics was not restudied during high- or low salt intake. It is concluded that there is no difference in central hemodynamics in salt-sensitive and salt-resistant hypertensive patients when they are on their habitual salt diet.

Adult↗
PubMed1994

The acute effects of induced tachycardia on coronary sinus and arterial plasma levels of atrial natriuretic peptide and on arterial catecholamines.

Atrial natriuretic peptide (ANP) was measured in coronary sinus (CS) plasma in seven patients with induced tachycardia. Right atrial pressure (RAP) and femoral artery (FA) levels of ANP, noradrenaline (NA) and adrenaline (A) were measured before and after 5 min with tachycardia. During tachycardia, ANP in CS plasma increased from 381 +/- 273 (mean +/- SD) to 1376 +/- 1191 pmol l-1 (p < 0.0001), and ANP levels in FA plasma from 89 +/- 48 to 231 +/- 151 pmol l-1 (p < 0.005). A significant increase was observed for peak RAP, whereas mean RAP remained unaltered. While no correlation existed between the increase in CS plasma ANP level and RAP, significant correlations were found between the changes in FA plasma ANP and RAP, and between FA plasma levels of ANP and NA. Following tachycardia, significant correlations were found both between ANP in CS and FA plasma and between the changes in these plasma levels. Whereas the changes in FA plasma levels of ANP during tachycardia seems dependent of RAP and arterial plasma levels of NA, the CS plasma ANP level appears to be independent of the two factors, probably because CS plasma ANP are drained mainly from the left side of the heart.

Adult↗
PubMed1993

Microtubule-associated distribution of specific granules and secretion of atrial natriuretic factor in primary cultures of rat cardiomyocytes.

A close spatial relationship between specific granules containing atrial natriuretic factor (ANF) and microtubules was demonstrated in primary cultures of neonatal rat cardiac myocytes. For the detection of specific granules and microtubules, the myocytes were double immunolabeled with antibodies against alpha-ANF and beta-tubulin and examined by conventional fluorescence or laser scanning confocal microscopy. In addition, the ultrastructural distribution of specific granules was demonstrated by electron microscopy. In the atrial myocytes, ANF was stored in numerous specific granules that were mainly localized in the perinuclear sarcoplasm. In the ventricular myocytes, however, a minority of the cells (10%) exhibited limited ANF immunoreactivity after 4 days in culture. Microtubules were present throughout the sarcoplasm of the myocytes. They were most densely packed in the perinuclear regions. Depolymerization of the microtubules with nocodazole was followed by dispersal of ANF immunostaining both in the atrial myocytes and in the ventricular myocytes exhibiting ANF immunoreactivity. When the microtubules were allowed to recover, the perinuclear distribution of specific granules, as seen in non-treated myocytes, reappeared. Measurements of secreted immunoreactive ANF by radioimmunoassay revealed that the secretion of ANF from atrial myocytes into the medium was significantly reduced following nocodazole treatment, whereas a similar decrease in secretion from ventricular myocytes was not observed. These findings indicate that ANF-containing specific granules are closely associated with microtubules within the myocytes. It is suggested that secretion of ANF from the atrial myocytes, in contrast to the ventricular myocytes, is microtubule-dependent.

Animals↗
PubMed1993

Can disulfiram potentiate the dexamethasone suppression test in depressive patients?

Transient DST non-suppression during disulfiram-treatment was fortuitously observed in a depressed patient. A disulfiram-potentiated DST (DSTd) was constructed by giving 800 mg disulfiram on the dexamethasone and postdexamethasone days. DST and DSTd were compared intraindividually in 21 patients and 14 controls. Disulfiram-potentiation was significant in constantly depressed patients, and in questionable controls due to possible subclinical depression or somatic factors which may cause 'false-positive' results. It did not occur in depressed patients during marked improvement or long-term recovery, and not in accurately screened controls. DSTd was significantly correlated with depression ratings, whereas DST was not.

Administration, Oral↗
PubMed1993

Inhibition and down-regulation of protein kinase C in cultured atrial myocytes: effects on distribution of specific granules and secretion of atrial natriuretic peptide.

Primary cultures of neonatal rat atrial myocytes were subjected to down-regulation of protein kinase C (PKC) and to inhibition of PKC activity. The effects on secretion of atrial natriuretic peptide (ANP), and the intracellular distribution of ANP-containing specific granules and their association to microtubules, were investigated. Treating the cultures with inhibitors of PKC, staurosporine or H7, a translocation of ANP-containing specific granules from the perinuclear sarcoplasm to the periphery of the myocytes was observed, and furthermore, secretion of ANP was significantly decreased. The microtubule network were not structurally affected by the PKC inhibitors. Down-regulation of PKC by 12-O-tetradecanoylphorbol 13-acetate (TPA) for 12 h was not followed by any alteration of localization of specific granules, and the amount of secreted ANP was still considerable. Treating the down-regulated cultures with staurosporine, secretion of ANP was still significantly reduced. The present results suggest that the decreased ANP secretion and the translocation of ANP-containing specific granules in the atrial myocytes following treatment with staurosporine or H7, is mediated through mechanisms not, or only partly, requiring PKC.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Atrial natriuretic factor in cats subjected to acute myocardial ischaemia.

Eighteen anaesthetized open chest cats were subjected to 10, 30, or 50 min occlusion of the left anterior descending coronary artery (LAD). Heart rate, left ventricular end-diastolic (LVEDP) and systolic pressure (LVSP), and dp/dt were continuously recorded during the experiments. Prior to LAD-occlusion, and just before termination of the experiments, blood samples were collected from the left femoral artery for measurements of atrial natriuretic factor (ANF), catecholamines, electrolytes, urea, and creatinine. Simultaneously, biopsies were collected from the right auricular wall. The tissue was embedded in Lowicryl K4M, and ultrathin sections were incubated with anti-ANF antibodies and secondary antibodies conjugated to gold particles. The density of ANF-containing atrial-specific granules labelled with gold particles was morphometrically calculated. LVEDP increased significantly in all three time groups, and when pooling the pre- and postocclusion values, there was an increase from 5.1 +/- 0.4 to 10.3 +/- 1.2 mmHg (p < 0.05). The noradrenaline level increased from 0.93 +/- 0.18 to 2.34 +/- 0.75 nmol l-1 (p < 0.05) after LAD-occlusion. Similarly, the mean plasma level of ANF in the 18 cats increased from 57.6 +/- 11.9 to 98.9 +/- 22.6 pmol l-1 (p < 0.05). Atrial granular density appeared to decline after 10 min of occlusion (from 0.141 +/- 0.017 to 0.127 +/- 0.022 granules-1 microns 2 sarcoplasm), and after 30 min there was a significant decrease (0.080 +/- 0.012 granules/microns 2, p < 0.05). However, after 50 min occlusion the granular density was almost restored (0.133 +/- 0.017 granules/microns 2). Plasma ANF showed a positive linear correlation to LVEDP and to the noradrenaline level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effects of carvedilol on atrial natriuretic peptide, catecholamines, and hemodynamics in hypertension at rest and during exercise.

Possible counterregulatory neurohumoral and hemodynamic responses to carvedilol (a new vasodilating nonselective beta-receptor blocker) were studied in 19 men with essential hypertension (age range, 34-59 years; mean age, 44 years). Intra-arterial pressure, cardiac output (Cardio-green), heart rate, and the vasoactive peptides norepinephrine, epinephrine, and atrial natriuretic peptide (ANP) were measured at rest supine and sitting and during 100-W bicycle exercise before and 2 h after administration of 25 mg carvedilol. The same protocol was followed after 9 months of chronic carvedilol treatment (mean dose, 52 mg/day). Carvedilol induced both acute and chronic reductions (at rest supine, 11%) in mean arterial pressure, due in part to reduction in cardiac output (5%) and in part to reduction in total peripheral resistance (5%). At rest supine, carvedilol induced a reduction in ANP (27%) that could be viewed as a counterregulatory response to decrease in cardiac output, preventing excessive blood pressure reduction. ANP decreased (18%) when the patient sat up from the supine position and increased (67%) during exercise, but no further change was seen after acute or chronic carvedilol treatment. With the patient in the sitting position, norepinephrine was 110% higher than at rest supine; during 100-W exercise, norepinephrine increased 368%. A further increase (38-86% in the three situations, respectively) was seen after the first dose of carvedilol. Epinephrine showed similar but less marked changes. Neither extracellular fluid volume nor plasma volume (isotope dilution techniques) changed significantly during the study, but the acute blood pressure response to carvedilol was directly related to changes in extracellular fluid volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1989

Maturity-onset diabetes of the young. Studies in a Norwegian family.

A Norwegian family showed 20 cases of verified or suspected diabetes in 5 generations, 13 being females and 7 males. In 12 patients the diagnosis was established at 26 years of age or earlier. Fourteen patients were definitely non-insulin-dependent. A high frequency of severe diabetic ophthalmopathy was noted, five patients were blind, two had proliferative retinopathy, and one simplex retinopathy and cataract. Five patients from the last 3 generations were islet cell antibody negative and C-peptide positive. In selected patients the serum insulin response to oral glucose was markedly reduced. HLA determinations in these patients showed absence of DR3 and DR4, and presence of DR2. The inheritance of diabetes in this family is compatible with an autosomal, dominant trait, and the majority of cases fulfilled the criteria of maturity-onset diabetes of the young. The high frequency of severe ophthalmopathy underscores that this disease may have an unfavourable evolution.

Adolescent↗
PubMed1988

Serum thyroglobulin as a preclinical tumour marker in subgroups of thyroid cancer.

Serum samples from a biological serum bank taken several years before the diagnosis of cancer, were analysed for S-Tg and S-TSH in 43 patients with thyroid cancer and compared to 128 healthy controls matched for age, sex, geographical region and time of blood sampling. The main finding was the difference in S-Tg between cases and controls, the highest values being found in sera from cases. Relative risk of thyroid cancer increases with increasing S-Tg levels (the global test giving P less than 0.0005). Extremely high levels were found in 4 cases with follicular and 3 with anaplastic cancers. No such statistically significant difference was found in S-TSH concentration. Possible explanations for the elevated S-Tg observed several years before clinically evident malignant tumour are discussed.

Adult↗
PubMed1987

Androgen-oestrogen imbalance in men with chronic alcoholism and fatty liver.

The plasma concentrations of oestrone (E1), oestradiol (E2), oestrone sulphate (E1S), testosterone (T), sex hormone binding globulin (SHBG) and apparent free testosterone (AFTC) were measured in 20 normal-weight men with chronic alcoholism and fatty liver. Twenty normal-weight male blood donors matched for age acted as controls. In the alcoholic subjects (patients) the plasma levels of E1, E2 and SHBG were significantly elevated, whereas the concentrations of E1S and AFTC were significantly decreased. No difference in plasma T was seen between the two groups. Both patients and controls showed a significant correlation between SHBG and E2, whereas a significant correlation between SHBG and T, and between E2 and T, was only found in the controls. Eight of the patients showed signs and/or symptoms of hypogonadism or feminization. Only patients with hypogonadism and/or feminization showed significantly higher plasma levels for E2 and decreased T/E2 ratio than matched controls. The ratio E1S/E1 was in every case lower than in the control and tended to be even lower in the patients with hypogonadism and/or feminization.

Adult↗
PubMed1986

Splanchnic extraction of oestrone and oestradiol and production of oestrone sulphate in man.

The plasma concentrations of oestrone (Oe1), oestradiol (Oe2) and oestrone sulphate (Oe1S) were measured in the femoral artery (FA), femoral vein (FV) and hepatic vein (HV) in seven men and three postmenopausal women undergoing catheterization for the evaluation of cardiac arrhythmias. None of the persons had congestive heart failure; conventional liver function tests were normal, and they were without any medication. The plasma concentration (mean +/- SD) for Oe1 was 34.6 +/- 19.5 pM in HV, 134 +/- 71.6 pM in FV and 93.4 +/- 48.5 pM in FA. The plasma concentration of Oe2 was 29.9 +/- 19.7 pM in HV, 80.3 +/- 42.7 pM in FV and 55.2 +/- 28.1 pM in FA. The results support the concept of peripheral formation of Oe1 and Oe2 and hepatic removal. The plasma concentration of Oe1S was 980 +/- 469 pM in HV, 945 +/- 463 pM in FV and 937 +/- 461 pM in FA. The small difference in plasma level of Oe1S between FA and FV was insignificant. In all persons the plasma level of Oe1S was higher in HV than in FA and FV (2P less than 0.01) indicating a net formation of Oe1S in the splanchnic area.

Adult↗
PubMed1986

Hepatic oestrone sulphotransferase activity and plasma levels of oestrone sulphate, oestrone and oestradiol in male guinea pigs with fatty liver.

Fatty liver was induced in male guinea pigs by combined administration of carbon tetrachloride and azathioprine from the 3rd to 15th week of age. The final body and liver weights were significantly lower than in the control animals, whereas the liver weight in percentage of total body weight was equal. The protein concentration in the 105,000 X g cytosol fraction from the livers was significantly lower than in controls (2P less than 0.02). The oestrone sulphotransferase activity was studied by measuring the oestrone sulphate production when incubating oestrone, PAPS + [35S]PAPS and liver cytosol for 1 h. Significantly less oestrone sulphate per mg protein, per gram liver tissue or total liver was produced with cytosol from animals with fatty liver than from controls (2P less than 0.02). In accordance with decreased oestrone sulphotransferase activity, animals with fatty liver revealed significantly lower plasma levels for oestrone sulphate (2P less than 0.02), whereas the plasma levels for oestrone and oestradiol were increased (2P less than 0.02). The present study supports the assumption of decreased oestrone sulphotransferase activity being important for the changes in plasma oestrogens seen in alcoholic men with fatty liver.

Animals↗
PubMed1984

Central nervous reactions to a 6.5-hour altitude exposure at 3048 meters.

In this study of CNS reactions to mild hypoxia, 7 subjects were decompressed to the equivalence of 3048 m altitude breathing air, for 6.5 h. On reaching 3048 m, and for every second h thereafter, a battery of neuropsychological tests were administered. In addition, blood and performance measures were sampled and a symptom check list was administered. The performance tests indicated significant effects of hypoxia. In contrast to earlier studies on grade of hypoxia and performance, no relationship between impaired performance and duration of exposure to hypoxia was found. Repeated testing throughout exposure indicated stable individual reactions. Endocrine variables did not support the hypothesis that activation or 'stress' caused the impairment observed. In addition to impaired neuropsychological test performance and impaired task performance, the subjects reported headache, weakness and some dizziness. Comparisons between different tests confirmed previous results showing that mild hypoxia yields varying degrees of impairment on different cognitive functions.

Adult↗