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Glutathione transferases play an important role in the detoxification of many different endogeneous and exogenous compounds such as metabolites of polycyclic aromatic hydrocarbons (PAH) of cigarette tar. There is evidence that PAH may be atherogenic. The glutathione transferase activity towards trans-stilbene oxide (GST-tSBO) can be separated in blood in GST-positive and GST-negative phenotypes. We have previously suggested that the GST-negative phenotype may be associated with a higher morbidity in intermittent claudication among middle aged smokers. In the present study, GST-tSBO could easily be measured in human, rabbit and bovine arterial smooth muscle cells (SMC) in culture. The level of GST-tSBO was higher in rabbit than in bovine SMC. It was stable in bovine SMC during 5 cell passages and it could be induced twofold by long-time incubation with dimethylsulfoxide-soluble particulate matter from cigarette smoke or 3,4-benzo(a)pyrene. There was a positive correlation between the level of GST-tSBO in blood and in "healthy" arterial and venous tissue from individuals operated with coronary bypass. The enzyme levels in arterial tissue were lower than in venous tissue. GST-tSBO in atherosclerotic segments of human arteries was lower than in "healthy" segments from the same artery. These findings suggest that the arterial wall may have a low defense against toxic compounds that may decrease further as atherosclerosis proceeds. It is concluded that SMC are suitable for the study of the effects of PAH in relation to GST-tSBO and that the enzyme activity in blood will reflect the individual GST-tSBO phenotype also in vascular tissues.

Glutathione transferase activity towards trans-stilbene oxide (GT-tSBO), an enzyme involved in the detoxification of many substances such as polycyclic aromatic hydrocarbons, was studied in 77 consecutive patients operated with coronary bypass, 73 patients with intermittent claudication, 78 healthy smokers and in 38 healthy non-smokers. The mean ages of these groups were similar. Lack of GT-tSBO was recorded in 45% of coronary bypass patients, in 39% of smoking coronary bypass patients, in 61% of patients with intermittent claudication, in 41% of healthy smokers and in 31% of healthy non-smokers. The lack of GT-tSBO was significantly more frequent among patients with intermittent claudication compared to healthy non-smokers (p less than 0.01) and healthy smokers (p less than 0.025) and to smoking coronary bypass. It is concluded that the lack of GT-tSBO is found more frequently among patients with intermittent claudication and this might contribute to explain the sensitivity to smoking among these subjects.

The effects of desmopressin acetate (DDAVP) on platelet aggregation and the von Willebrand factor antigen (vWF:Ag) were studied in 19 patients undergoing cardiac surgery with extracorporeal circulation. The patients represented one of five blocks in a randomized double-blind placebo-controlled parallel group trial on the effects of DDAVP on postoperative bleeding after uncomplicated coronary artery bypass operations. After termination of extra-corporeal circulation, DDAVP (0.3 microgram/kg body wt) or its vehicle was infused into a peripheral vein throughout 15 minutes. The increase in factor VIII coagulant activity after infusion did not differ between the groups but there was a significantly larger increase in vWF:Ag levels in DDAVP-treated patients. The aggregatory response to adenosine-diphosphate (ADP) and ristocetin showed a normal pattern and was not significantly different between the two groups. As compared with placebo, DDAVP did not decrease the bleeding time or the postoperative blood loss. We conclude that DDAVP causes an increase in vWF:Ag levels but does not alter platelet aggregation, bleeding time, or blood loss in uncomplicated coronary artery bypass patients.

Six pigs were used to study whether the collection of shed blood by means of surgical compresses instead of suction traumatizes such blood. In an in vivo part of the study, the whole blood volume of the pigs was retransfused after treatment with citrated compresses, and in an in vitro part the blood was treated extensively with compresses and analyzed. All animals survived, with a minor fall in hemoglobin after 48 hours and a rise in serum citrate concentration at the end of the experiment. A study of the coagulation system revealed no important change after retransfusion of compress-treated blood. In the in vitro part of the study, repeatedly squeezing blood from the compresses increased the concentration of free hemoglobin to a maximum of 5 g/l after ten squeezes, whereas platelets were numerically unchanged. The study indicates that collecting shed blood by means of surgical compresses may be a safe and efficient method.

Standardized intra-abdominal hemorrhage was induced in 7 anesthetized pigs. The resulting hypovolemic shock was treated with pneumatic anti-shock garment (PASG) followed by intra-aortic balloon occlusion. The effects of this treatment on circulation, lung mechanics and gas exchange were studied. Hemorrhage was induced by pulling out sutures introduced in the inferior caval vein. We found that the use of PASG partially restored mean arterial blood pressure from 44 +/- 6 to 66 +/- 6 mm Hg. When intraaortic balloon occlusion was added, the arterial pressure returned to basal levels. Cardiac output fell severely due to the hemorrhage from 3.7 +/- 0.2 to 1.3 +/- 0.2 liters/min and could not be restored during the treatment. A severe fall in total lung compliance was recorded after inflation of the PASG from 18.6 +/- 0.9 to 10 +/- 0.7 ml/cm H2O, this was accompanied by a fall in alveolar ventilation. These findings emphasize the severe restriction in lung function that occurred during treatment with PASG. Both parameters returned to near normal values when the PASG was deflated and the intra-aortic balloon was inflated. Pulmonary vascular resistance increased by more than 400% and remained high during the study period. There was no change in arterial PO2, however the fall in mixed venous PO2 caused by hemorrhage was reversed at the end of the treatment. Indirect monitoring of cerebral function by continuous EEG showed a decreased voltage during the hemorrhage, this was reversed by the combined treatment. We conclude that the outlined treatment makes it possible to restore central hemodynamics and preserve cerebral function at least for a short period of time until definite surgical treatment can be performed. However, severe restriction on lung mechanics, especially when PASG was inflated, makes it probable that ventilatory support can be necessary in such cases.

The black-fly fauna of Drovrefjell National Park, Central Norway, was investigated at elevations between 870 m and 1 630 m and covered the sub-alpine, low- and middle-alpine vegetation zones. We found 13 black-fly species and a dominance of three non-bloodsucking species, Prosimulium ursinum, Cnephia tredecimata and Eusimulium crassum, in this area. E. crassum dominated the bog stream habitat, while C. tredecimata and P. ursinum dominated the outlet habitat. The parthenogenesis of P. ursinum is an advantage over a sexual reproduction in the extreme habitat of glacier fed outlets. While mammalophilic species were absent or scarce, we found a high proportion of bird-feeding Eusimulium spp. E. corniferum and E. carpathicum have not been previously recorded from Norway.

Two-sided Malaise traps were set across streams, on the banks of streams and at standing water to reveal patterns of the flight behaviour of Rhyacophila nubila (Zetterstedt), Halesus radiatus Curtis and Potamophylax cingulatus (Stephens). The males had similar flight patterns, a random flight, in all habitats. Females flew upstream above the running water only, while they elsewhere flew at random. Females of all species and males of R. nubila and H. radiatus flew in less numbers on the banks than above the running water. Males of P. Cingalatus flew in significantly higher numbers on the bank than above the running water. Characteristics of the running water must be a major factor initiating the upstream flight in females.

Field studies were carried out on male swarms of Mystacides azurea L. and Athripsodes cinereus Curtis (Leptoceridae) at Lake Erken in south Sweden. It was found that: (1) A dummy conducted in the swarm attracted the swarming males, which flew up to it for a short investigation. (2) The males were more attracted to a dummy pendulating over or in the swarm (resembling an approaching receptive female) than to any other type of movement. (3) A dummy infused with female extract (dichloromethane) placed just above the swarm did not attract the males more than the control. These experiments support the hypothesis that the male mate recognition in leptocerids mainly is visual. A sexual dimorphism in eye proportions was also found, which significance is briefly discussed

Species diversity data from 19 light trap samplings are presented. Some data from England and Sweden were extracted from the literature. The extended negative binomial model was used in the calculation of the species diversity. Using α and k as population parameters with standard errors, the data were plotted in a diagram and appeared as ellipses. Species diversity for total flight periods, year to year, and seasonal variations are dealt with. The method seems to give a more detailed separation of communities than Shannon and Simpson indices.

An experimental model for controlled massive bleeding in pigs was developed to evaluate a new method for intraoperative autotransfusion of concentrated whole blood. The animals were injured in the descending thoracic aorta, creating a massive bleeding into the left pleural cavity. By means of a new system for autotransfusion, the animals were kept alive by retransfusing the blood at the same rate as it was shed. All animals were in good condition after autotransfusion of bleeding corresponding to three blood volumes. The postoperative hematological status including hemoglobin, hematocrit, platelet counts and electrolytes was not significantly different from the values before the experiment. The coagulation assays, including platelet adhesiveness, were normal after the experiment. In one pig the urine was positive for hemoglobin using a Hemostix test although it was macroscopically clear. This new method allows autotransfusion of whole blood with a desired hematocrit, with intact platelets and coagulation factors.

A new autotransfusion device for collection and retransfusion of whole blood is described. The construction, function and possible advantages of the system compared with currently available systems are discussed. The system is built up around a hollow fibre haemoconcentrator (dialysis filter), a cardiotomy reservoir and a large volume infusion bag. To prevent clotting, citrate (ACD-solution) is added in the suction tubing as well as locally. The blood is driven through the system by a roller pump.

Aquatic stages of many invertebrates living in shallow areas of lakes and pools may at wintertime be found completely surrounded by ice. Papers remarking on this phenomenon were published as early as in the last decade of the 18th century. Field investigations and temperature measurements in lakes and pools in Central Norway have revealed that e.g. the larvae of the phryganeid Agrypnia obsoleta may be completely embedded by ice for a period of 6 months and survive temperatures down to − 10 to − 11°C in the bottom substrate layers where the specimens stayed.