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Biomedical subjects

K Savolainen

Publications and source records attributed to K Savolainen.

At least 91 records · Page 5Linked to original sources
PubMed1982

Acute solvent-ethanol interactions with special reference to xylene.

Acute ethanol ingestion inhibits the metabolism of the common industrial solvents trichloroethylene and dimethylformamide. The solvents in turn may interact with ethanol metabolism as shown by an accumulation of acetaldehyde and occasional symptoms of alcohol intolerance. It was recently found that mutual metabolic interaction occurs even in the context of ethanol ingestion (0.8 g/kg in single dose) combined with subsequent inhalation exposure to m-xylene (6.0 & 11.5 mmol/m3 (140 & 280 ppm), over 4 h). Ethanol impaired the metabolic clearance of m-xylene, raised the blood xylene concentration, and decreased the urinary excretion of methylhippuric acid. Thus, ingestion of ethanol is a noticeable source of error in the biological monitoring of xylene uptake. Some people appear to be susceptible to combined ethanol-xylene exposure and may develop nausea and dermal flush.

Alcohol Drinking↗
PubMed1982

Treatment of osteomalacia in institutionalized epileptic patients on long-term anticonvulsant therapy.

The efficacy of vitamin D2 in the dose of 2000 IU daily in reversing anticonvulsant osteomalacia was studied in nine epileptic inpatients. The treatment with vitamin D2 was associated with increased serum 25-hydroxycalciferol and 24,25-dihydroxyvitamin D concentrations and partial healing of osteomalacic changes in the cancellous bone of the iliac crest. But it was concluded that the dose of vitamin D2, 2000 IU daily, was too small and that calcium supplementation may be needed in addition to vitamin D therapy.

24,25-Dihydroxyvitamin D 3↗
PubMed1982

Caffeine antagonizes diazepam effects in man.

In a double-blind, placebo-controlled study on parallel groups of medical students diazepam 10 mg impaired cognitive skills and caused muscle relaxation. A 250 mg dose of caffeine given in decaffeinated coffee counteracted these better than a 500 mg dose. Subjectively, diazepam exerted a calming effect which was counteracted by caffeine at either at either dose levels.

Adult↗
PubMed1982

Anticonvulsant osteomalacia in epileptic outpatients.

The occurrence of anticonvulsant osteomalacia was studied in 23 epileptic outpatients, and in age and sex matched controls. Hypocalcaemia was observed in 10, hypophosphataemia in 1, and increased serum alkaline phosphatase in 8 of the patients. The serum 25-hydroxyvitamin D concentration was significantly lower In the patients than in the controls, but no difference was found in the serum 24,25-dihydroxyvitamin D concentration between the patients and the controls. There was no difference in bone mineral density between the patients and the healthy controls. In the histomorphometric study, no differences were found in the amount of trabecular bone or osteoid between the patients and the controls, but the patients had a slightly more extensive trabecular resorption surfaces. Histological osteomalacia was found in two of the 23 cases (9%). We conclude that epileptic outpatients on long-term anticonvulsant therapy have vitamin D deficiency and may develop osteomalacia.

Adult↗
PubMed1981

Short-term exposure of human subjects to m-xylene and 1,1,1-trichloroethane.

Nine healthy male students were exposed to singular atmospheric concentrations of m-xylene (8.2 mumol/l; 200 ppm) or 1,1,1-trichloroethane (TCE) (8.2 and 16.4 mumol/l; 200 and 400 ppm), and also to a combination of xylene (8.2 mumol/l) and TCE (16.4 mumol/l) for 4 h per day at 6-day intervals. The effects of the atmospheric xylene and TCE concentrations on psychophysiological functions such as reaction time, body balance and CFF thresholds were studied. The exposures to xylene alone and to the lower TCE concentrations usually tended to improve the performances, whereas the higher TCE concentration alone or in combination with xylene tended to have an opposite effect, although statistically significant changes in performance, as compared to the control values, were rare. The results thus suggest a biphasic effect of TCE on the central nervous system (CNS), slight stimulation of the CNS at lower and depression at higher TCE concentrations. The results also revealed that xylene and TCE together exhibited neither kinetic interaction nor synergistic nor antagonistic effects on the CNS functions studied.

Adult↗
PubMed1981

Changes induced by xylene and alcohol in human evoked potentials.

Neurotoxic effects of industrial solvents have recently aroused great interest. Few studies have applied evoked potential methods to test acute or chronic neurotoxicity of solvents or alcohol. Eight young healthy male volunteers were exposed for 4 h to about 1200 or 700 mg/m3 of xylene alone or in combination with alcohol 0.8 g/kg. Single doses of 0.4 g/kg and 0.8 g/kg alcohol were also used as test substances, and the subjects stayed for 4 h in the exposure chamber also during 3 control days. Tests were conducted single-blind and the subjects acted as their own controls. Visual (VEPs) and somatosensory (SEPs) evoked potentials as well as electroretinograms (ERGs) were recorded in the mornings before the exposure and in the afternoons immediately after exposure stopped. A single dose of alcohol 4 h prior to recording increased the latencies of P50, N60, P115 and N155 of VEP dose-dependently. Alcohol alone did not change significantly the amplitude of VEP, but xylene 1200 mg/m3 in combination with alcohol 0.8 g/kg decreased significantly the amplitude of N60-P115. The lower concentration of xylene in combination with alcohol as well as xylene 1200 mg/m3 alone tended to have similar effects. Concerning the latency changes simultaneous xylene exposure tended to counteract the effect of alcohol. No significant effects on ERGs could be shown in any of situations. The effects of SEPs were minor or lacking, and the lower exposure levels were associated with more statistically significant changes than higher exposure levels.

Adult↗
PubMed1981

Osteomalacia in institutionalized epileptic patients on long-term anticonvulsant therapy.

The occurrence of anticonvulsant osteomalacia was studied in 31 epileptic inpatients, 16 women and 15 men. Disturbances in biochemical parameters indicating osteomalacia were frequent. Thirty two per cent of the patients were hypocalcemic, 55% had an increase in S-ALP and 26% in U-HOP, and dU-Ca was decrease in 55%. The S-25OHD3 concentrations were significantly lower in the patients compared with healthy controls. BMD was decreased in females but not in males compared wih the controls. Histomorphometric analysis revealed an increase in the amount of osteoid, but the amount of trabecular bone was no lower than in the controls. The amount of resorption surfaces was increased in the females, but not in the males. The patients who took less physical activity had a pronounced decrease in BMD. The conclusion drawn was that osteomalacia is a frequent complication of long-term anticonvulsant medication, especially among institutionalized patients.

Adult↗
PubMed1981

Xylene and alcohol involvement of the human equilibrium system.

Ten healthy male subjects were exposed at weekly intervals to m-xylene concentrations of 6 mumol/1 (145 p.p.m.) and 11.5 mumol/1 (290 p.p.m.) for 4 hrs alone and in combination with the prior ingestion of single doses of alcohol (0.8 g/kg). Alcohol alone was ingested at two dose levels, 0.4 and 0.8 g/kg. Body sway was recorded with a strain gauge transducer platform with the subjects' eyes closed and open, and the eyes closed/open ratio, indicating the grade of visual compensation for body balance, was calculated. The variation observed in the eyes closed/open ratio in different experimental situations was due to changes with the eyes closed rather than to differences with the eyes open. Alcohol or a xylene concentration of 6 mumol/1, as well as their combination, had little if any effect on this ratio. Exposure to a xylene concentration of 11.5 mumol/1 tended to decrease the eyes closed/open ratio, possibly due to functional tolerance or adaptation. Interestingly, alcohol with a xylene concentration of 11.5 mumol/1 significantly increased the ratio, a finding suggesting an unexpected combined effect of xylene and alcohol, possibly of metabolic origin, on the human equilibrium system. The possible mechanism of this action remains to be elucidated.

Adult↗
PubMed1980

Combined effects of xylene and alcohol on the central nervous system.

Ten healthy male students were exposed to m-xylene alone at concentrations of about 6 and 11.5 mumol/l and given a single dose of alcohol (0.4 and 0.8 g/kg) prior to exposure. The effects of these xylene concentrations and alcohol doses, as well as the combined effects of the two xylene concentrations with the higher alcohol dose on psychophysiological functions, such as body balance and reaction time, were assessed. Xylene alone did not significantly impair these functions, although there was a tendency towards impairment by the exposure to the higher xylene concentration. The impairment caused by alcohol alone was dose-dependent and exceeded that caused by xylene alone. The deleterious effects of xylene combined with alcohol were usually additive, although antagonism of alcohol effects on body balance by the higher xylene concentration was observed. The effects were pharmacodynamic rather than pharmacokinetic in nature.

Adult↗
PubMed1980

Effects of xylene and alcohol on vestibular and visual functions in man.

Ten healthy male volunteers were exposed for 4 h to two concentrations [6 and 11.5 mumol/l (636 and 1,218 mg/m3)] of m-xylene or/and given single doses (0.4 and 0.8 g/kg) of ethyl alcohol. Exposure to two xylene concentrations combined with the higher dose (0.8 g/kg) of alcohol was also conducted. Vestibular functions (positional nystagmus with electronystagmography, body balance) and visual function (flicker fusion) were measured. Both alcohol doses increased body sway and the intensity of nystagmus more than either concentration of xylene did, but they had little effect on visual functions. The effects of alcohol on vestibular functions were dose-dependent. The effects of xylene alone on the vestibular system were rather small, and those on the visual functions negligible. The combined effect of alcohol and the lower concentration of xylene (6 mumol/l) on body sway was additive, but the higher xylene concentration (11.5 mumol/l) antagonized the effect of alcohol on body sway and positional nystagmus. Two subjects experienced nausea and vomited exposure to alcohol and the higher xylene concentration. Mild impairment in visual functions was noted in the combined exposure. Alcohol significantly increased the blood m-xylene concentrations, a finding that suggests that their antagonism was pharmacodynamic rather than pharmacokinetic.

Adult↗
PubMed1980

A seasonal difference in serum 25-hydroxyvitamin D3 in a Finnish population.

A chromatographic assay procedure for the analysis of 25-hydroxyvitamin D3 [25(OH)D3] in human serum is described. The procedure involves methanol/chloroform extraction of serum lipids followed by separation of the vitamin D metabolites and purification from interfering contaminents by chromatography on Sephadex LH-20 and by high-pressure liquid chromatography. 25(OH)D3 is quantitated by uv detection, and its peak height compared with those of standards. Values in normal human serum samples taken in July-August and January-February are: 33.0 +/- 13.6 ng/ml (82.5 +/- 34.1 nmol/1) and 14.5 +/- 12.2 ng/ml (36.3 +/- 30.5 nmol/1) (means +/- SD), respectively (p less than 0.001). The summer values are somewhat lower in the elderly subjects as compared to younger ones, but a seasonal difference was observed in both groups. This difference may be due to a relatively low vitamin D intake and a limited sun exposure.

Adolescent↗
PubMed1979

Importance of using proper techniques to teach cardiopulmonary resuscitation to laymen.

Immediate attempts to resuscitate patients with cardiac arrest by lay bystanders distinctly increase the chances of survival in such patients. In the present study we investigated possibilities of intensifying the cardiopulmonary resuscitation (CPR) training of laymen. A group of 46 young conscripts (test group) was given 2 hours of CPR instruction in what was considered the most efficient way. The procedures included showing a film on the theory and practice of CPR, a discussion of the film, and then 3 to 5 min instructed individual practice with a recording manikin. Another 56 conscripts participated in a 1-h illustrated lecture on CPR, which was followed by group training with a non-recording manikin; they served as a reference group. The performance of the subjects in CPR was measured with a recording manikin before and 2 months after the training. Before training, none of the subjects passed the surprise resuscitation test. After training, the skills of 62% of the subjects in the test group were acceptable according to original criteria for lay public, and 28% passed the test according to the strict criteria for medical personnel. The less intensive training given to the reference group did not improve the acceptability of resuscitation. It is concluded that CPR training for laymen may lead to failure to attain an adequate level of skill. Proper training techniques and equipment are important, but even their use does not guarantee that an adequate level of CPR performance will be attained by all laymen if their skills are not later refreshed.

Adult↗
PubMed1979

Effects of m-xylene on human equilibrium measured with a quantitative method.

Swaying during normal upright posture in 17 young males and the effects of m-xylene exposure on the body sway of six of the 17 has been studied by a quantitative Romberg test, conducted with an equipment consisting of a strain gauge transducer platform and of an electronic unit. The exposures were conducted in a dynamic exposure chamber. The sway of the 17 subjects was larger when their eyes were closed than when they were open (P less than 0.001) indicating the importance of vision in the control of body balance. Exposure to a time-weighted average (TWA) concentration of 100 p.p.m. (4.1 mumol/l) of xylene with 200 p.p.m. (8.2 mumol/l) peaks had no observable effect on the body balance of the six subjects. Exposure to a TWA concentration of 200 p.p.m. of xylene with 400 p.p.m. (16.4 mumol/l) peaks--the corresponding mean concentration of xylene in venous blood being 29.1 +/- 3.2 mumol/l--clearly impaired the body balance of the six subjects. The impairment was most pronounced with the eyes closed (P = 0.016). The results suggest that human equilibrium is rather sensitive to effects of exposure to xylene.

Adult↗
PubMed1978

The influence of water activity on the stability of vulgaxanthin I.

The stability of vulgaxanthin I at 100 degrees C is dependant on the water activity of the system. The half-life of vulgaxanthin I was found to be three times greater at aw 0.20 than at 1.00. The rate constants for vulgaxanthin I degradation varied exponentially with respect to water activity and below aw = 0.50 the stability was not improved.

Drug Stability↗