PubMed Health⌕ Search

Biomedical subjects

A Pekkarinen

Publications and source records attributed to A Pekkarinen.

At least 19 recordsLinked to original sources
PubMed1994

Service of snowmobiles in the wilderness and villages.

The maintenance of terrain vehicles like snowmobiles has been developed for arctic wilderness use by paying attention to occupational health, safety and quality and efficiency of work. A small tent carried on a snowmobile sledge supplied with heating and lighting equipment was planned, built and tested. It was sized based on an ergonomic survey for the servicing of snowmobiles. The planned thermal and occupational aims were reached at temperatures down to -35 degrees C. Two movable, shielded fluorescent lamps with total of 140 W electric power was enough to produce 150 lx illumination and the local illumination for the repair point was 700 lx. The 8 kW warm air fan had enough power to hold the temperature inside at the desired level with an outside temperature of -35 degrees C. The fan was also used as a local heater by conducting warm air to the hands and tools. The temperature of the fingers was close to the comfort level, when repair work was carried in the tent. When the repair work was carried out outside, the finger temperature was near the risk of cold injury. The handles of the tools were made from heat insulating materials, which raised the contact skin temperature with about 3 degrees C.

Cold Temperature↗
PubMed1992

Prevention of accidents in reindeer herding work.

In the northern part of Finland we have about 450,000 reindeer and their raising gives work to about 3,500 reindeer herders. In this study data on the occupational accidents of herders were collected by two questionnaires with an interval of 2 years. Based on the surveys of accident risks in various work phases 34 preventive measures were developed and information about them was passed on to the herders between the questionnaires. Most of the accidents occurred in the late autumn during slaughtering, gathering for separation and during separation work. The main causes of accidents were the slaughtering knife (30%) and the reindeer itself (25%). The most serious accidents were caused by snowmobiles and other terrain vehicles. The recommended preventive measures mostly dealt with the environment of permanent working places, personal protection and working habits. The follow-up questionnaire showed that the herders had implemented on an average 5.8 preventive measures. The incidence rate of accidents also decreased during the 2 years from 21 to 12 accidents/1000 working days. In conclusion these results show that it is possible to develop measures preventing accidents and to improve the safety in reindeer herders' work.

Accidents, Occupational↗
PubMed1992

Safety in the use of four-wheeled all-terrain vehicles in Finland.

The aim of this study was to ascertain the use of four-wheeled all-terrain vehicles in Finland and estimate the safety in driving a four-wheeler. According to the importers there are about 3,000 four-wheelers in use in Finland. A questionnaire was sent to the owners of four-wheelers (n = 185), in which questions were asked about their use, protection used when driving, accidents that had occurred and suggestions for developing four-wheelers. One hundred three answers (response rate 56%) were received. The respondents reported minor injuries (15%) and dangerous situations: the four-wheeler had fallen over (35%) and the driver had fallen off the four-wheeler (20%). The accidents and dangerous situations were concentrated to occupational users who drove a lot in poor terrain. Four-wheeler driving was estimated to be more dangerous than snowmobile driving. According to the answers the most efficient measures to improve safety would be the use of a safety helmet and high boots when driving as well as the enforcement of an age limit for the driver. The technical properties of the four-wheelers could also be developed e.g. the leg room, foot board and protective roll bar.

Accident Prevention↗
PubMed1986

Plasma vasopressin levels during and after cardiopulmonary bypass in man.

The effect of cardiopulmonary bypass (CPB) using high dose fentanyl anaesthesia on the concentrations of plasma arginine vasopressin (pAVP), serum electrolytes and osmolality was studied in 12 patients by repeated sampling up to 4th postoperative day. These values were also followed in another 20 patients for the first postoperative day. Fentanyl abolished the pAVP response often seen in major operations but not that produced by CBP. The pAVP concentration 4.8 +/- 0.8 pg/ml immediately after sternotomy increased to 27.2 +/- 1.5 pg/ml (P less than 0.001) after 5-10 minutes on CPB. By the 4th postoperative day the pAVP levels had reached normal values. The main reason for the elevated pAVP concentrations seems to be the onset of CPB, which provokes a fall in mean arterial pressure leading to pAVP release.

Adolescent↗
PubMed1985

Optimum dosage of lidocaine.

Lidocaine dosage recommendations vary widely. Severe heart failure adds to risk factors when attempting to reach the optimal therapeutic blood level. Fifty-two coronary care unit (CCU) patients, who were treated with lidocaine infusion after an initial bolus injection of 100 mg, were randomly selected for the study. Blood samples were drawn at 2, 6 and 18 h. The material was divided into four groups according to infusion rates: Group A (n = 15) 4 mg/min for 3 h and then 3 mg/min for 15 h, Group B (n = 10) 4 mg/min for 3 h and then 2 mg/min for 15 h, Group C (n = 9) 2 mg/min for 18 h and Group D (n = 18) according to clinical situation by a mean rate of 3.3 mg/min for 2 h, 2.5 mg/min for 4 h and 2.15 mg/min for 12 h. The mean serum lidocaine concentrations were in optimum therapeutic range of 2-4 mg/l in Groups A, B and D at every sampling time point. Percentage of the patients whose lidocaine concentrations at each sampling time were within the optimum range as follows: Group A 72, 67 and 52, Group B 70, 70 and 56%, Group C 0, 38 and 63% and Group D 38, 38 and 30%. Our material indicates that the optimal lidocaine infusion rate for CCU patients should be as in Group B.

Aged↗
PubMed1981

Failing effect of digoxin on myocardial uptake of violamycin B1.

The effect of digoxin on both the negative inotropic action and the myocardial uptake of a new anthracycline antibiotic violamycin B1 has been studied in isolated guinea pig atria. In concentrations upto 2.0 X 10(-7) M/l digoxin did not prevent the negative inotropic effect of violamycin B1 caused by the concentrations of 0.7 and 5.0 X 10(-4) M/l. Corresponding to these findings, the uptake of violamycin B1 into the atrial tissue was not influenced by digoxin. However, violamycin B1 in the cardiotoxic concentration of 5.0 X 10(-4) M/l decreased the atrial uptake of digoxin. It is suggested that no competition seems to exist in myocardial uptake of anthracycline antibiotics and cardiac glycosides.

Aminoglycosides↗
PubMed1981

Dialysability of benzodiazepines by haemodialysis and controlled sequential ultrafiltration (CSU) in vitro.

The efficacy of haemodialysis and controlled sequential ultrafiltration (CSU) for the elimination of three hypnotic and 6 benzodiazepine drugs was compared in vitro. In comparison to haemodialysis the efficacy of ultrafiltration by CSU was poor, as the mean per cent of CSU/haemodialysis (mg/hr) for 5 benzodiazepines was only 0.6-4.0% and for three hypnotics, phenobarbital 3.4%, pyrithyldione 8.2% and glutethimide 2.5% of the haemodialysis values. In haemodialysis in vitro phenobarbital, pyrithyldione, glutethimide and chlordiazepoxide were significantly and markedly more dialysable than 5 other benzodiazepines. The mean clearance of six benzodiazepine derivatives was about 2 to 3 times higher at blood flow rates of 200 ml/min. than 100 ml/min. In CSU experiments in vitro it was possible to remove approximately (as the mean percent of the initial dose) only the amount of five benzodiazepines corresponding to the per cent of the protein unbound fraction in the plasma (correlation r = 0.975, P less than 0.01). Only low amounts of three hypnotics, especially glutethimide, were removed by CSU in vitro.

Benzodiazepines↗
PubMed1980

Comparative in vitro investigations on the dialysability of hypnotic and psychotropic drugs by hemodialysis and controlled sequential ultradiffusion.

The efficiency of hemodialysis and controlled sequential ultradiffusion (CSU) for the elimination of toxic drug concentrations was tested by in vitro-investigations. In the 6 benzodiazepin derivatives tested, the clearance is markedly higher at a blood flow of 200 ml/min than at 100 ml/min. Pyrithyldione, glutethimide and phenobarbital are better dialysed than the benzodiazepines with exception of chlordiazepoxide. In comparison with hemodialysis, hemofiltration by means of CSU was less effective because of the small amount of ultrafiltrate obtained.

Anti-Anxiety Agents↗
PubMed1980

Enzyme inducing effects of phenobarbital on nitrazepam metabolism in dogs.

A 6-day peroral phenobarbital treatment of beagle dogs decreased clearly and significantly the mean AUC (1252 +/- 270 ng/ml/hr) of a single peroral dose of nitrazepam (1.5 mg/kg), as a sign of enzyme induction to one third (428 +/- 37 ng/ml/hr P < 0.05) in plasma and the concentration maximum (Cmax) (301 +/- 62 ng/ml/hr) to one third (110 +/- 15 ng/ml/hr, P < 0.05), respectively. The mean Kel, 0.36 +/- 0.04, increased to 0.54 +/- 0.04 (P < 0.05), respectively. An 11-day phenobarbital treatment decreased the mean AUC of nitrazepam further to one sixth (197 +/- 41 ng/ml/hr, P < 0.01) and the Cmax to one fifth (65 +/- 10 ng/ml/hr, P < 0.01), while the mean Kel increased from 0.36 +/- 0.04 to 0.65 +/- 0.02 (P < 0.001). The 12- day peroral nitrazepam treatment showed no sign of autoinduction as a single daily dose. The mean AUC of a single nitrazepam dose of the 1st day, 1290 +/- 256 ng/ml/hr increased after the 24-day nitrazepam treatment, to 3617 +/- 202 ng/ml/hr and after the 61-day treatment to 3379 +/- 321 ng/ml/hr. The mean maximum concentration (Cmax), 343 +/- 69 ng/ml/hr, increased to 727 +/- 52 ng/ml/hr, respectively.

Animals↗
PubMed1979

Pharmacokinetics of nitrazepam in saliva and serum after a single oral dose.

The pharmacokinetics of nitrazepam in saliva and serum was studied in 12 healthy volunteers after a single administration of a 5 mg nitrazepam tablet. The binding of nitrazepam to plasma proteins was determined 4 hours after the administration by ultracentrifugation. The analysis of nitrazepam concentrations was performed by 63Ni-EC-GLC. The pharmacokinetic parameters were evaluated manually or by AUTOAN-program in serum, and manually in saliva. The concentrations of nitrazepam in serum and saliva correlated significantly (r = 0.472, P less than 0.001, n = 97). The ratio saliva: serum was, however, time dependent. The protein free fraction in serum was significantly higher (P less than 0.01) than the salivary concentration at the same time (4 hours after administration). The peak concentrations in serum and saliva were 40.7 and 1.9 ng/ml (P less than 0.001) and the times to reach the peak maximum 2.4 and 2.5 hours, respectively (difference not significant). The mean half-life of nitrazepam in serum was 30.5 hrs and in saliva 39.9 hrs, the difference being significant at P less than 0.05. The distribution phase parameters, poorly described before, were calculated. The clinical value of nitrazepam analysis in saliva seems to be negligible.

Administration, Oral↗
PubMed1978

Catecholamines and free fatty acids in plasma of patients undergoing cardiac operations with hypothermia and bypass.

Plasma concentrations of adrenaline, noradrenaline, and free fatty acids were measured at different stages of cardiac operations in which hypothermia and bypass were used. The rise of adrenaline, noradrenaline, and free fatty acid concentrations in plasma is consistent with the concept that these are important compounds in stress situations such as hypothermia and surgical operations. There is a more marked release of adrenaline and it may be a more specific hormone in response to hypothermia and bypass than is noradrenaline in man.

Cardiac Surgical Procedures↗
PubMed1977

Serum growth hormone levels in schizophrenic patients during sleep.

Ten schizophrenic and five epileptic patients under antipsychotic drug treatment were studied to evaluate sleep-related GH secretion. Four of the schizophrenic patients had a high secretion peak of GH (range 15.2 to 38.0 ng/ml), four had a moderate peak (range 5.8--8.3 ng/ml), while two had no increase in GH secretion during sleep (range 0.5--1.0 ng/mg). Four of the five epileptic patients had a moderately increased secretion (range 5.8--9.2 ng/ml) and one had no increase in GH secretion during sleep. Thus, the GH secretory pattern varied with the patient as in known to be also with healthy individuals. However, no clear disturbances were noted in sleep-related GH secretion in schizophrenic patients receiving antipsychotic drug treatment, when compared e.g. to non-schizophrenic, epileptic patients under a same kind of drug treatment.

Growth Hormone↗
PubMed1977

Cerebrospinal-fluid concentrations of nitrazepam in man.

The concentrations of nitrazepam in the plasma and cerebrospinal-fluid (CSF) of 38 neurological patients were determined by gas chromatography 2-36 hours after a single 5 mg oral dose. The percentage ratio between the mean CSF and the plasma concentrations increased from 8.0% at 2 hours to 15.6% at 36 hours. This percentage rise was significant (P less than 0.001). The maximum concentration of nitrazepam in the plasma was 36.7 +/- 5.7 ng/ml (at 2 hours) and CSF 3.0 +/- 0.3 ng/ml (at 4 hours). During the beta-phase the half-life of nitrazepam in plasma was about 27 hours and in the CSF markedly longer about 68 hours, indicating a very slow elimination of nitrazepam from the CSF.

Administration, Oral↗
PubMed1976

Change in hormones reflecting sympathetic activity in the Finnish sauna.

The effects of the high temperature (80-120 degrees C) of the Finnish Sauna bath on the concentrations of growth hormone, immunoreactive insulin and renin activity in plasma, on blood glucose and on the urinary excretion of aldosterone, vanilmandelic acid and sodium of 55 healthy volunteers were studied. There was a significant increase in mean heart rate (62%), serum growth hormone (142%) and plasma renin activity (95%) in the Sauna. One hour after the Sauna bath the mean serum growth hormone had returned to the control level while plasma renin activity still remained higher (p less than 0.05) than before the Sauna bath. The serum insulin, blood sugar and urinary excretion of aldosterone and VMA did not change during or after Sauna bath. The urinary sodium excretion decreased significantly after the Sauna bath and the decrease was most striking (46%) during the first 6-hour period from the beginning of Sauna bath. Plasma renin activity values correlated positively with 12-hour urinary VMA excretion (p less than 0.01) and negatively with 6-hour urinary sodium excretion (p less than 0.05) before and after Sauna, suggesting the role of catecholamines and sodium depletion in renin response in Sauna.

Aldosterone↗