C3c and C3d fragments of human C3 bind myeloma IgG1 and IgG3 proteins

Eight human myeloma proteins, two of each IgG subclass, were studied for binding to solid-phase C3c and C3d by the ELISA technique. Myeloma IgG₁κ, IgG₁λ, IgG₃κ and IgG₃λ proteins bound to C3c and C3d, while two IgG₂κ, and two IgG₄κ proteins failed to show significant binding affinity. The results suggest that like C1q, the stable binding sites of C3, located on the C3c and C3d parts of the molecule, have affinity for IgG subclasses 1 and 3.     

The association between decision-making skills and subjective decision outcomes among administrative officers in the Swedish Social Insurance Agency

Social insurance administrative officers’ decision-making skills influence their efficiency at work and their general well-being. At work their tasks are characterised by complexity and a need for order and accountability. Moreover, cases should usually be handled and finalised within the imposed time frames. We investigated skills related to decision-making success among social insurance officers. In total, 118 administrative officers at the Swedish Social Insurance Agency (66% response rate) responded to questions on scales and measures relating to cognitive-rational, socio-emotional and time approach features of decision-making skill. In addition, they responded to questions on three scales pertaining to outcomes of everyday decisions in terms of subjective everyday difficulties, tendencies to burnout and depressive symptoms. The results showed that cognitive-rational competence was associated with lower reports of subjective everyday difficulties and depressive symptoms and thereby contributed to the explained variance in decision outcomes. Furthermore, socio-emotional and time approach features of decision-making skills contributed to the explanation for subjective everyday difficulties, tendencies to burnout and depressive symptoms. The results corroborate the basic assumption and usefulness of a broad approach in the definition and assessment of decision-making skills in human service professions in general, and of administrative officers in social insurance agencies in particular. Recommendations for future research and the implications of the results are discussed.     

Dual action of angiotensin II on coronary resistance in the isolated perfused rabbit heart

Summary We studied the functional role of angiotensin II (AII) receptor subtypes and vasodilatory endothelial autacoid release in response to AII in isolated perfused rabbit hearts. AII infusion induced biphasic changes in coronary perfusion pressure (CPP): an initial increase was followed by a decrease until a plateau was reached. At higher concentrations of AII (10 nmol/l) this plateau phase was lower than the initial CPP level. AII infusion elicited inverse changes in peak left ventricular pressure (LVP): coronary constriction was associated with a transient decline, and during the plateau phase LVP was clearly increased. AII also moderately augmented prostacyclin (PGI₂) release from the coronary vascular bed. The AII-induced changes in CPP, LVP, and PGI₂ release were effectively inhibited by the AT₁ receptor subtype antagonist ICI D8731 (30 nmol/l), but not by the AT₂ receptor antagonist CGP 42112 (30 nmol/l). The adenosine A₁ receptor antagonist 8-phenyltheophylline (0.1 mol/l) attenuated the decline in CPP following the constriction phase without affecting the changes in LVP during AII infusion. The cyclooxygenase inhibitor diclofenac (1 mmol/l) had no effect on the AII-induced changes in CPP, whereas the nitric oxide-synthase inhibitor N^G-nitro-L-arginine (30 mol/l) markedly potentiated the vasoconstriction but was without effect on the plateau phase of the response. In contrast to AII, the thromboxane analogue U46619 elicited sustained increases in CPP which were associated with slight decreases in LVP.In conclusion, AII induced a biphasic pressor response in the rabbit coronary vascular bed consisting of a transient vasoconstriction followed by a dilatation especially at higher concentrations of AII, an effect which was independent of the endothelial autacoids nitric oxide and PGI₂. The AII-induced dilatation probably reflected rapid desensitization of the coronary arterial smooth muscle to the constrictor effect, and the concomitant accumulation of vasodilatory metabolites such as adenosine, generated during the positive inotropic action of AII. All the effects of AII in the rabbit heart appeared to be mediated via the AT, receptor subtype localized on coronary endothelial and smooth muscle cells, as well as on cardiomyocytes.On leave from the Department of Biomedical Sciences, University of Tampere, P.O. Box 607, FIN-33101 Tampere, FinlandCorrespondence to: I. Pörsti     

Control of mesenteric arterial tone in vitro in humans and rats

The majority of the findings concerning arterial physiology and pathophysiology originate from studies with experimental animals, while only limited information exists about the functional characteristics of human arteries. Therefore, the aim of the present work was to compare the control of vascular tone in vitro in mesenteric arterial rings of corresponding size (outer diameter 0.75–1 mm) from humans and Wistar-Kyoto rats. The relaxations to acetylcholine (ACh) were clearly less marked in the mesenteric arteries of humans when compared with rats. How-ever, when calcium ionophore A23187 was used as the vasodilator, the endothelium-mediated relaxations did not significantly differ between these species. The NO synthase inhibitor N ^G-nitro-l-arginine methyl ester (l-NAME) attenuated the relaxations to ACh and A23187 in both groups. The endothelium-independent relaxations to the β-adrenoceptor agonist isoprenaline and the nitric oxide (NO)-donor nitroprusside were somewhat lower in human arteries, while vasodilation induced by the K⁺ channel opener cromakalim was similar between humans and rats. Arterial contractile sensitivity to noradrenaline and serotonin was slightly lower in human vessels, whereas contractile sensitivity to KCl was similar between these species. The contractions induced by cumulative addition of Ca²⁺ with noradrenaline as the agonist were effectively inhibited in both groups by the calcium channel blocker nifedipine, the effect of which was clearly more pronounced in human arteries. In conclusion, the control of vascular tone of isolated arteries of corresponding size from humans and rats appeared to be rather similar. The most marked differences between these species were the impaired endothelium-mediated dilation to ACh and the more pronounced effect of nifedipine on the Ca²⁺-induced contractions in human arteries. Received: 1 October 1998 / Accepted: 4 January 1999     

General thoracic surgery in Finland,a perspective from the Helsinki University Hospital

The field of thoracic surgery is a rapidly developing field due to exciting developments in technology and oncologic treatments as well as continuous innovation in surgical technique. Although the population of Finland is relatively small, general thoracic surgery is represented at a high level in five centralized university centers, Helsinki University Hospital, Tampere University Hospital, Turku University Hospital, Kuopio University Hospital and Oulu University Hospital. Thus, high case volume and good results are achieved in these centers. Here, we describe a short history, current state and future prospects of the field of cardiothoracic surgery in Finland, with a focus on general thoracic surgery and the perspective of Helsinki University Hospital. From the field’s birth in Finland, marked by the first lobectomy, in the late 1930’s, it has grown and adapted more and more modern techniques such as totally minimally invasive esophagectomy and robotic lung cancer surgery. Nowadays, most of general thoracic surgery in Helsinki University Hospital is either minimally invasive or robotic and open surgery is the exception to the norm. Helsinki University Hospital has a strong presence in the European general thoracic surgery community and aims to do so in the future by investing on training & education, research and surgical innovation.     

Challenges in investigation of diabetes-related aviation fatalities—an analysis of 1491 subsequent aviation fatalities in USA during 2011–2016

Diabetes mellitus (DM) could cause pilot incapacitation and result in aviation fatalities. The mechanisms could be directly as a consequence of acute hypoglycemia/subacute diabetic ketoacidosis (DKA) or indirectly as an acute cardiovascular event by contributing to the development of atherosclerosis in coronary or carotid and cerebral arteries. In this study, DM-related fatal flight accidents in the US National Transport Bureau’s database between years 2011–2016 were analyzed with special emphasis on postmortem (PM) glucose levels and correlation of toxicological reports with anamnestic information on DM. Additionally, autopsy results on coronary arteries were reviewed. In 43 out of 1491 (~ 3%) fatal accidents pilots had DM. Postmortem glucose or glycated hemoglobin percentage (Hb1Ac) was measured in 12 of the 43 cases; while antidiabetic medication was found in 14 of the cases (only two of the cases had both glucose measurements and medication). With the increasing prevalence of DM, a possibility of pilot incapacitation due to DM or complications of DM should be actively studied, even if no anamnestic information of DM was available. While PM hypoglycemia is difficult to assess, we propose a systematic investigation based on measurement of glucose, Hb1Ac%, and ketone bodies, and documentation of atherosclerotic lesions in major arteries to identify or rule out DM as a cause of pilot incapacitation.

     

Treatment of impaired perfusion in septic shock

Severe sepsis and septic shock are relatively common problems in intensive care. The mortality in septic shock is still high, and the main causes of death are multiple organ failure and refractory hypotension. Impaired tissue perfusion due to hypovolemia, disturbed vasoregulation and myocardial dysfunction contribute to the multiple organ dysfunction. Treatment of hemodynamics in septic shock consists of appropriate fluid therapy guided by invasive monitoring combined with vasoactive drugs aiming to correct hypotension and inappropriately low cardiac output. The drug of choice for low vascular resistance is norepinephrine, while insufficient myocardial contractility is commonly treated with dobutamine. The use of norepinephrine seems to be associated with better prognosis as compared to results from the use of dopamine or epinephrine. In septic shock, vasopressin levels are low, and therefore, vasopressin has been advocated as a vasopressor. Its effectiveness and safety have not yet been documented, and so far it is regarded as an experimental treatment. Recent data support the use of corticosteroid, at least in some of the patients with septic shock. Also, activated protein C, a drug with anti-inflammatory and antithrombotic properties, decreases mortality in patients with septic shock.     

Plasma renin substrate and oestrogens in normal pregnancy

Relationship between concentrations of serum oestrogens, plasma renin substrate and plasma renin activity were studied in six women throughout pregnancy. There was a significant positive correlation between serum oestradiol-17β and plasma renin substrate concentrations (r=0.60). Serum oestriol concentrations also correlated significantly with plasma renin substrate concentrations (r=0.68). Correlation coefficients calculated separately for each subject throughout pregnancy were higher than those for the whole group. Also, there was much individual variation in dose-response of serum oestrogens to plasma renin substrate concentrations. There was no significant correlation between serum oestrogens and plasma renin activity.

Our results support the view that oestrogens cause the increase in plasma renin substrate concentration during pregnancy, and emphasize the individual variation in response of renin substrate concentration to serum level of oestrogens.