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Biomedical subjects

L Jalkanen

Publications and source records attributed to L Jalkanen.

At least 19 recordsLinked to original sources

Distemper vaccination of farmed fur animals in Finland.

The most important farmed fur animal species in Finland are the American mink (Mustela vison), blue fox (Alopex lagopus), silver fox (Vulpes vulpes) and raccoon dog (Nyctereutes procyonoides); all are susceptible to canine distemper. The only distemper vaccines currently available are for mink, although they also have been used for fox and raccoon dogs in emergency situations. The efficacy in eliciting neutralizing antibodies and the safety of three mink-distemper vaccines were studied under field conditions with mink and silver fox. Two of the vaccines were also studied with raccoon dogs and blue fox. All three vaccines elicited a satisfactory antibody response in mink, whereas the response varied in the other species. No side effects were observed in any species tested. One of the vaccines was safe and immunogenic in all four species.

Animals↗

Control of red fox (Vulpes vulpes) fertility with cabergoline: dose response and timing of intervention.

Cabergoline, a potent dopamine agonist and inhibitor of prolactin secretion, was investigated as a potential fertility control agent in the red fox ( Vulpes vulpes). Sixty silver fox vixens were selected randomly and artificially inseminated. Cabergoline was fed to groups of 12 vixens in a minced beef ration either as a single dose of 25, 50 or 100 microg kg(-1), or a dose of 50 microg kg(-1) that was repeated 2 days later (2 x 50 microg kg(-1)). Four foxes from each group of 12 were given cabergoline at day 28, day 35 or day 48 after artificial insemination, and a control group of four foxes was used as a comparison for each dose day. In a separate trial, two groups of five foxes were selected randomly from the farm population and fed 100 microg kg(-1) of either cabergoline or a placebo each day from day 42 to day 46 of pregnancy. Foxes that received single doses of cabergoline of 100 microg kg(-1) or 2 x 50 microg kg(-1) aborted at day 28, but the same doses did not result in abortions when administered on days 35 and 48. Although lactation was not terminated in groups that received a single or double dose of cabergoline, increased post-natal cub mortality was associated with cabergoline administration. Growth of cubs between 4 and 8 weeks of age was not inhibited in vixens that received cabergoline. Doses of 100 microg cabergoline kg(-1) administered each day from day 42 to day 46 resulted in abortions and terminated lactation. The capacity of single doses of cabergoline to cause abortions in the red fox during mid- rather than late pregnancy is contrary to reported observations for the domestic dog. This finding indicates that luteotrophic support of the corpus luteum by prolactin may be more important at mid-pregnancy in the red fox. The results of this study support previous field observations that cabergoline delivered in bait affects the reproductive success of vixens and may be a practical adjunct to the lethal control of wild red foxes in Australia.

Abortion, Induced↗

The effect of large anthropogenic particulate emissions on atmospheric aerosols, deposition and bioindicators in the eastern Gulf of Finland region.

The effect of the emissions from large oil shale fuelled power plants and a cement factory in Estonia on the elemental concentration of atmospheric aerosols, deposition, elemental composition of mosses and ecological effects on mosses, lichens and pine trees in the eastern Gulf of Finland region has been studied. In addition to chemical analysis, fly ash, moss and aerosol samples were analysed by a scanning electron microscope with an energy dispersive X-ray spectrometer (SEM/EDS). The massive particulate calcium emissions, approximately 60 kton/year (1992), is clearly observed in the aerosols, deposition and mosses. The calcium deposition is largest next to the Russian border downwind from the power plants and in south-eastern part of Finland. This deposition has decreased due to the application of dust removal systems at the particulate emission sources. At the Virolahti EMEP station approximately 140 km north from the emission sources, elevated elemental atmospheric aerosol concentrations are observed for Al, Ca, Fe, K and Si and during episodes many trace elements, such as As, Br, Mo, Ni, Pb and V. The acidification of the soil is negligible because of the high content of basic cations in the deposition. Visible symptoms on pine trees are negligible. However, in moss samples close to the power plants, up to 25% of the leaf surface was covered by particles. Many epiphytic lichen species do not tolerate basic stemflow and on the other hand most species are also very sensitive for the SO2 content in air. Consequently a large lichen desert is found in an area of 2500 km2 in the vicinity of the power plants with only one out of the investigated 12 species growing.

Aerosols↗

Successful embryo transfer in the silver fox (Vulpes vulpes).

Surgical embryo transfer in the silver fox was investigated as part of a larger project concerning the conservation of endangered canine species using modern artificial reproduction techniques with the farmed fox as a model. The animals were chosen on the basis of synchrony in natural oestrus. The timing of ovulation and artificial insemination was determined by measuring electrical resistance in the vagina. Twenty-nine embryos were flushed from eight humanely killed donor females and transferred surgically into the uteri of eight recipients. One recipient female gave birth to two male pups 47 days after the transfer of four expanded blastocysts and one embryo at the 16-cell stage derived from a donor female flushed 10 days after artificial insemination.

Animals↗

The pharmacodynamics of mivacurium preceded by atracurium or cisatracurium in children.

UNLABELLED: We evaluated whether mivacurium maintains its short duration of effect when preceded by atracurium or cisatracurium in 45 children during propofol/alfentanil/N2O/O2 anesthesia. Neuromuscular response was recorded by using an adductor pollicis electromyogram (EMG). Children were randomized to receive two doses of atracurium (350 micrograms/kg and 70 micrograms/kg in Group AM), cisatracurium (64 micrograms/kg and 10 micrograms/kg in Group CM), or mivacurium (200 micrograms/kg and 100 micrograms/kg in Group MM), followed by a final dose of mivacurium 100 micrograms/kg. The second and third doses of the muscle relaxants were administered at 25% EMG recovery. After the final dose of mivacurium, the times to 95% of EMG recovery in groups AM, CM, and MM were (median with 10-90 percentile range) 33.0 (28.0-40.0) min, 30.7 (26.0-40.3) min, and 10.3 (8.0-14.0) min, respectively (P < 0.0001). The recovery times to a train-of-four ratio of 0.70 were 30.3 (24.7-37.0) min, 28.0 (24.7-37.7) min, and 10.3 (8.0-13.7) min for groups AM, CM, and MM, respectively (P < 0.0001). Thus, the duration of effect of mivacurium was prolonged by 200% if preceded by either atracurium or cisatracurium. IMPLICATIONS: We compared the pharmacodynamics of mivacurium given alone or preceded by atracurium or cisatracurium in children. The duration of effects of mivacurium was prolonged by 200% if preceded by either atracurium or cisatracurium. This implies that mivacurium has a short duration of effect only when given as a single relaxant.

Adolescent↗

The influence of the duration of isoflurane anaesthesia on neuromuscular effects of mivacurium.

BACKGROUND: The pharmacodynamic profile of muscle relaxants is usually changed by volatile anaesthetics. These changes seem to be time-dependent, even though few data are available to substantiate this. METHODS: We studied neuromuscular effects of a single dose of mivacurium (0.2 mg.kg-1) during short and intermediate duration of isoflurane anaesthesia. Forty-five children 1-10 years of age were randomized to receive 1.5% end-tidal concentration of isoflurane in N2O/O2 for 10 or 30 min (groups Iso-10 and Iso-30, respectively) or to receive nitrous oxide in oxygen for 10 min (Group N2O) before 0.2 mg.kg-1 of mivacurium was given. Neuromuscular response was recorded by adductor pollicis electromyogram. RESULTS: The onset time of mivacurium was shorter in Group Iso-30, 1.7 (1.0-2.3) min than in Group Iso-10, 2.3 (1.7-3.3) min or Group N2O, 2.3 (1.7-3.3) min (median with 10-90% percentiles) (P < 0.05). In Group Iso-30 the recovery time of the first EMG response was significantly longer than in groups Iso-10 and N2O (P < 0.0001). Groups Iso-10 and N2O did not differ from each other. CONCLUSION: Our results indicate that the duration of a constant concentration of isoflurane anaesthesia influences significantly the pharmacodynamics of mivacurium. The duration of a volatile anaesthesia is critical when potentiation of NMB is evaluated or compared in neuromuscular studies.

Anesthesia↗

[Comprehensive obesity therapy program].

Being overweight is now accepted as one of the big health problems of our society. A major extent of overweight is associated with numerous disease and has to be considered as a disease itself. Considerable and intensive efforts are necessary to terminate the increasing trend or to turn it into the opposite direction. The OPTIFAST-program is an extensive therapy program with nearly guaranteed success. As compared to other programs, the longterm results are good, though they still need considerable improvement. A common strategy should be developed for a longterm and permanent program.

Adult↗

Effect of succinylcholine on subsequently administered mivacurium in children.

The interaction between mivacurium and succinylcholine when mivacurium was administered during the early recovery from succinylcholine block was studied in 30 children 2-12 years of age anaesthetized with propofolalfentanil-N2O-O2. Neuromuscular response was monitored by adductor pollicis EMG. Fifteen patients received 200 micrograms.kg-1 of mivacurium (Group M), and another fifteen received 1500 micrograms.kg-1 of succinylcholine followed by 200 micrograms.kg-1 of mivacurium when the first EMG response recovered to 5% of calibration value (Group SchM). Plasma cholinesterase (pChE) activity was normal in each patient. The recovery times following mivacurium did not differ between the two groups. Times required for recovery of the first EMG response from 25 to 75% of full EMG recovery were 3.6 +/- 1.0 (mean +/- SD) and 4.0 +/- 0.7 min for the Groups M and SchM, respectively. The time from administration of mivacurium to the recovery of train-of-four ratio 0.70 was 13.2 +/- 3.3 min for the Group M and 13.6 +/- 3.1 min for the Group SchM (NS). Thus, in patients with normal pChE activity preceding administration of succinylcholine did not influence the recovery of neuromuscular function from subsequent mivacurium.

Child↗

Synergism between atracurium and vecuronium in infants and children during nitrous oxide-oxygen-alfentanil anaesthesia.

This study was undertaken to see if infants are more sensitive than children to a combination of atracurium and vecuronium in an equipotent dose ratio: (microgram: microgram) 5:1 in infants and 4:1 in children. We studied 15 infants (1-11 months old) and 15 children (3-10 yr old) during nitrous oxide-oxygen-alfentanil anaesthesia. Neuromuscular function was recorded by adductor pollicis EMG. An individual dose-response curve of the atracurium-vecuronium combination was determined for every patient and its potency compared with that of the parent agents alone. The combination was significantly more potent than one parent agent, both in infants (P < 0.01) and in children (P < 0.0001). However, infants were less sensitive than children to synergism produced by the atracurium-vecuronium combination: if the ED50 dose of the parent agent is defined as one dose equivalent, then the mean ED50 doses of the combination were 0.81 (SEM 0.05) and 0.64 (0.03) dose equivalents in infants and children, respectively (P < 0.01). We suggest that an interaction between two binding sites of competitive neuromuscular blocking agents in postsynaptic acetylcholine receptors may explain both the synergism and sensitivity of infants to non-depolarizing neuromuscular blocking agents.

Alfentanil↗

Synergism between atracurium and mivacurium compared with that between vecuronium and mivacurium.

Synergism exists between some combinations of nondepolarizing muscle relaxants. To test the possibility of synergism between mivacurium and atracurium or vecuronium, 60 children anesthetized with propofol-alfentanil-N2O-O2 were randomized to one of five groups. Three groups of 10 patients each received an ED50 dose of a parent drug atracurium (A), vecuronium (V), or mivacurium (M), respectively, and two other groups of 15 patients each received a single-dose combination of atracurium with mivacurium (cAM) or vecuronium with mivacurium (cVM). Dose combinations constituted 0.5 times an ED50 dose of each drug. Neuromuscular response was monitored by adductor pollicis electromyogram (EMG). Maximum neuromuscular block (NMB) established by a single parent drug did not differ between the groups or from 50% NMB. It averaged 5.03 +/- 0.12 probits (51.2% NMB). On the contrary, maximum NMB established by the two-dose combinations, cAM or cVM, was significantly more than NMB produced by either single parent drug of the particular combination (cAM vs A or M; P = 0.0035, and cVM vs V or M; P = 0.0004) without a statistically significant difference between groups cAM and cVM. Maximum NMB established by combinations averaged 6.15 +/- 0.21 probits (87.5% NMB). The onset of maximum NMB for mivacurium was significantly faster compared to that for atracurium or for vecuronium (2.8 +/- 0.3 vs 5.7 +/- 0.4 or 4.0 +/- 0.3 min, respectively; P = 0.0001). Our results indicate that both drug combinations are synergistic even though only vecuronium is markedly different in its molecular structure from mivacurium.

Atracurium↗

Synergism between atracurium and vecuronium in children.

In 30 children under balanced anaesthesia, we have determined dose-response curves and maintenance requirement of three dose ratio combinations of atracurium and vecuronium (10:1, 4:1 or 1.6:1 on a microgram:microgram basis). Neuromuscular block was monitored by adductor pollicis EMG. An equipotent dose ratio (4:1) was most potent, with a mean (SEM) ED95 of atracurium 95 (6) micrograms kg-1 with vecuronium 24 (1) micrograms kg-1. The sum of these doses is only 58% of an ED95 value of one agent (P = 0.0001). The hourly requirement to maintain a 90-95% neuromuscular block was 2.0 (0.1) times an individual ED95 dose of any combination. Recovery index was 8.9 (0.5) min. These results indicate that a combination of atracurium and vecuronium is supra-additive compared with the effects of each drug alone. However, all combinations maintained an intermediate character of neuromuscular block. Combining atracurium with vecuronium may reduce drug requirement by 40%.

Atracurium↗

Species-specific features of oestrous development and blastogenesis in domestic canine species.

The reproductive physiology of taxonomically closely related species is usually very similar. The main difference in the reproduction of the dog and fox is the length of the different phases of the oestrous cycle. Pro-oestrus and oestrus are longest in the dog: oestrus lasts 3-5 days in the blue fox and 1-3 days in the silver fox, compared with about 1 week in the dog. The profiles of sex steroid concentrations in plasma during oestrus and pregnancy are similar and the luteal phase in non-pregnant animals is prolonged, progesterone concentrations reaching a maximum by 15-30 days after the luteinizing hormone (LH) peak in the dog, by 10-20 days in the blue fox and by 5-15 days in the silver fox. The duration from LH surge to ovulation is about the same in the dog and fox, but thereafter the oocytes and early embryos develop faster in foxes than in the dog. The tubal transport time is 4-6 days in the silver fox, embryos entering the uterus at the 4-16-cell stage. In the blue fox the oocytes remain in the oviducts for 8-10 days, developing into the morula stage, whereas in the dog a still longer oviductal phase results in embryos that are at the compact morula or blastocyst stage when entering the uterus. The preimplantation period is about 1 week in the dog and the blue fox, but 9-10 days in the silver fox.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Sperm abnormalities in silver fox (Vulpes vulpes) semen selected for artificial insemination.

Sperm morphology was examined in fresh ejaculates accepted for insemination. The material included 161 ejaculates of 36 male silver foxes. Samples were fixed, stained with eosin/nigrosin and evaluated microscopically. The abnormal spermatozoa were categorized by the location of the defect. The mean (+/- SD) percentage of morphologically normal spermatozoa was 87.55 +/- 10.45. The incidence of sperm defects was low and variation high in all defect classes. Defects of tails of spermatozoa accounted for > 50% of the abnormalities found. Morphological quality did not correlate with the volume of the sperm-rich fraction, mass activity, progressive motility, or total sperm count in ejaculates of acceptable sperm quality. The incidence and effects of morphological defects in low-quality semen remain to be studied.

Animals↗

The effect of a weight reduction program on cardiovascular risk factors among overweight hypertensives in primary health care.

The aim of the study was to test the effect of a nonpharmacological weight reduction program on cardiovascular risk factors among overweight hypertensives in a primary health care setting. Forty-nine overweight hypertensive patients completed the 12-month program. The patients were randomly allocated into either intervention or control groups. The examinations included interviews by a nutritionist, pertinent laboratory tests, and a medical examination. The intervention involved an individually planned energy-restricted diet of 1000-1500 kcal per day, weekly discussions, and various leaflets on diet modification and on increase of physical activity. The mean body weight was reduced by 5 kg in the intervention group, but remained unchanged in the control group. The intervention group reduced their fat intake by 14 g/day while the control group increased it by 9 g/day on the average. In the intervention group, the total serum cholesterol decreased, HDL-cholesterol increased and triglycerides decreased significantly. The systolic blood pressure fell by 8 mm Hg and 15 mm Hg in the intervention and control groups, respectively. The diastolic blood pressure fell on average by 11 mm Hg in both groups. The results demonstrate the comprehensive weight reduction program to be effective in the control of cardiovascular risk factors.

Adult↗

Changes in body mass index in a Finnish population between 1972 and 1982.

Population-based data on changes in body mass index are scarce. We have examined about 9700 people aged 30-59 years in two provinces of East Finland in 1972, 1977 and 1982. The age adjusted mean value of body mass index (kg m-2) in 1972 was 26.0 +/- 3.4 in men and 26.9 +/- 4.7 in women, increasing with age. During the 10-year follow-up the mean body mass index increased in men to 26.5 +/- 3.6 (P less than 0.001). In women we found a decrease in mean body mass index to 26.4 +/- 4.9 (P less than 0.001). The increase trend in body mass with age remained in women, while in men the age trend increased from survey to survey. The proportion of obese men also increased while in younger women a decrease was observed. The results of this study show the association between changes in physical activity, education etc. and the observed changes in the body mass index.

Adult↗

Body weight and risk of myocardial infarction and death in the adult population of eastern Finland.

Body mass index (weight (kg) divided by height squared (m2] and its association with the risk of myocardial infarction and death from all causes were studied prospectively in a randomly selected population sample in eastern Finland aged 30-59 at outset in 1972. The study population consisted of 3786 men and 4120 women. The participation rate in the survey in 1972 was over 90%. All deaths and admissions to hospital in the sample were obtained from the National Death Certificate and Hospital Discharge Registers. During the seven years of follow up until 1978, 170 men and 52 women had acute myocardial infarction, and during the nine years up to 1980, 223 men and 92 women died. Independent of age, men with a body mass index of 28.5 or more had a significantly higher incidence of acute myocardial infarction. This effect was also independent of smoking but not independent of biological coronary risk factors--that is, serum cholesterol concentration and blood pressure. In the analysis stratified for smoking in men the body mass index total mortality curve was J shaped among non-smokers, whereas smoking entirely outweighed body mass index as a predictor of death. Body mass index did not contribute significantly to the risk of either acute myocardial infarction or death in women. It is concluded that a body mass index of around 29.0-31.0 or more is not only a marker for coronary risk factors but is also a predictor of acute myocardial infarction in men.

Adult↗

Accuracy of self-reported body weight compared to measured body weight. A population survey.

In 1977, in the evaluation of the prevention programme for cardiovascular diseases, 11,880 persons in Eastern Finland were asked to report their own weight on a questionnaire. Each participant was weighted during the following clinical examination. The data of the self-reported body weight were analysed according to sex, age, measured weight and body-mass index (BMI). The results showed that older people underestimated their weight to a greater extent than did younger people of both sexes. The error between measured and self-reported weight was greater in heavier subjects than in thinner individuals. In both sexes weight estimate error (measured weight minus self-reported weight) correlated more strongly with high BMI than with measured weight. Associations between weight estimate error and other variables were studied using a multiple regression model. Men whose annual family income was low were more likely to underestimate their weight than the men with a high annual income. In general, women reported their weight more correctly than men did. Older women were more likely to report their weight less than younger women, whereas women who visited their doctor frequently or who had higher annual family incomes were more aware of their actual body weight than those who had few doctor's consultations or whose family income was low. In men 5.2% and in women 8.3% of the variation in the weight estimate error was explained by the regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Long-term effects of cessation of smoking on body weight, blood pressure and serum cholesterol in the middle-aged population with high blood pressure.

Smoking habits are continuously changing in the population. Cessation of smoking is not only often difficult but may lead to undesired consequences, esp. to weight gain. A random sample of 2283 persons with mild hypertension was followed up for 5 years in Eastern Finland and examined at the community-based cardiovascular program. During that time 30% of those smoking initially stopped smoking. Men gained weight on the average 3.6 kg upon stopping smoking (p less than 0.001) after controlling for age, change in fat and sugar intake and change in physical activity at leisure time). In women cessation of smoking was not related to weight changes. There was no evidence in this follow-up that smoking or cessation of smoking would have any independent impact on blood pressure or serum total cholesterol level.

Adult↗