Sunscreen application and its importance for the sun protection factor

To achieve a good sun protection, a layer thickness of 2 mg/sq cm is often recommended. Fifty individuals were asked to apply five different sunscreens ad libitum. Ten percent dihydroxyacetone was added to the sunscreens in order to make them fluoresce when irradiated with Wood's light. The layer thickness was calculated by dividing the amount applied by the area. The thicknesses of the sunscreen layers varied little between different parts of the body and different brands; in general it was close to 1 mg/sq cm. The corresponding protection factor was measured for two sunscreens on 20 persons. The results indicate that the sun protection factor under ad libitum conditions is only 50% of what would be achieved using a layer thickness of 2 mg/sq cm.     

Characteristics of the Factor VIII Protein and Factor XIII in Various Factor VIII Concentrates

The in vitro properties of 5 factor VIII preparations (AHF-Kabi, Hemofil Hyland, AHF-Profilate Abbott, Kryobulin Immuno and Factorate High Purity Armour) and an ordinary cryoprecipitate were studied with reference to factor VIII clotting activity (VIII:C), factor VIII clotting antigen (VIILCAg), factor VIII related antigen (VIIIR:Ag) (EI, IRMA, CIE), ristocetin cofactor activity (VIIIR:RCF), fibrinogen and factor XIII. All the preparations with the exception of Factorate had higher levels of VIII:CAg than VIII:C indicating inactivation of the biological activity of VIII:C during the procedure. AHF-Kabi (fraction I-0) and the cryoprecipitate, the only preparations capable of normalising the defect in patients with von Willebrand's disease, showed the same level of VIIIR:Ag determined by EI and by IRMA, while all the other preparations (i.e. cryoprecipitates purified further in different ways) had considerably lower levels of VIIIR:Ag determined by IRMA than by EL Based on these in vitro techniques it seems to be possible to predict which preparations can be used successfully in patients with von Willebrand's disease, while no such conclusions can be made from VIIIR:RCF determinations. EI yielded similar concentrations of factor XIII a subunit in all the preparations tested. 3 functional assays showed high factor XIII activities in AHF-Kabi but low or no activities in the others. Thus, considerable differences were found of the in vitro properties of the proteins in 5 factor VIII concentrates and a cryoprecipitate. The action of proteases and the techniques used in the purification procedure are probably of crucial importance for the properties of the various factors.     

Synthesis of 5-aryl-2H-tetrazoles, 5-aryl-2H-tetrazole-2-acetic acids, and [(4-phenyl-5-aryl-4H-1,2,4-triazol-3-yl)thio]acetic acids as possible superoxide scavengers and antiinflammatory agents

A series of 5-aryl-2H-tetrazoles, 5-aryl-2H-tetrazole-2-acetic acids, and [(4-phenyl-5-aryl-4H-1,2,4-triazol-3-yl)thio]acetic acids were synthesized and tested in vitro for superoxide scavenging activity, in vivo in the carrageenan-induced rat paw edema assay, and in the reverse passive Arthus reaction. The hydroxy-substituted compounds were effective as in vitro scavengers of superoxide but were not effective as in vivo antiinflammatory agents.     

Influence of Ketamine on Non-Pregnant Uterus in Vivo

This investigation was performed to evaluate the effect of ketamine anesthesia on non-pregnant uterine activity. Seven healthy non-pregnant women took part in the study. Anesthesia was induced with an i.v. bolus injection of ketamine 2 mg/kg and maintained with a continuous i.v. ketamine infusion, mean dosage 39 μg/kg/min. Before induction of anesthesia, each patient was placed in the lithotomy position, and a catheter fitted with two microtransducers for monitoring of intra-uterine pressures was fed through the cervix into the uterine cavity. For determination of plasma concentrations of ketamine and norketamine, venous blood samples were collected. The assay was based on a gas-liquid chromatographic technique. It was found that ketamine induced an increased uterine activity, both in basal tone and intensity of contractions. Only minor effects on the frequency were observed. This stimulatory effect was simultaneous with a hemodynamic stimulation with increases in heart rate and arterial blood pressure, and with the peak plasma concentration of ketamine.     

Pressure and flow measurements in the partially obstructed ureter of the rat

Hydronephrosis in man or experimental animals can be caused by an increased ureteral flow resistance. This condition can in the long run prove harmful to renal function. We compared two ways of measuring ureteral flow resistance in animals with and without a ureteral hindrance, the hindrance being induced by embedding the ureter in the psoas muscle. One needle connected via catheters to a pressure recording system and another connected to a pump system were introduced through the parenchyma into the renal pelvis. Experiments were carried out with two procedures: 1) infusion of 0.5 ml x min-1 of saline into the renal pelvis was performed while recording the pressure response; 2) a servocontrolled pump system was used which regulated the flow introduced into the renal pelvis to keep a preset pressure at a constant level. In the first group of experiments we did not establish a steady-state pressure despite 20-30 min of infusion. The result from the second series of experiments indicated that steady-state flow measurements could be achieved at the different pressure levels between zero and 30 mmHg. A good linear relationship between pressure and flow was found, even though a considerable hysteresis was observed. Furthermore, a reduced flow resistance down to a certain level at increased pressure was also recorded. As expected, the resistance to flow was significantly lower in the control than in the hydronephrotic animals. In order to investigate the diagnostic ability of the linear relationship between pressure and flow, prediction regions for one future animal were calculated. It seemed possible that determination of the whole pressure-flow relationship in the pressure range between zero and 30 mmHg will prove useful to determine the flow hindrance in hydronephrotic animals.     

The influence of a new low molecular weight sulphated polysaccharide from mussel broth (Org 30016) on haemostasis

The effect on haemostasis of a new low molecular weight sulphated polysaccharide (4300 dalton) from mussel broth (Org 30016) was investigated. In an APT time test system it had an anticoagulant effect corresponding to 30-40% of that of heparin. It had no antithrombin effect. It exerted its effect only in test systems containing phospholipids. It did not prolong haemostatic plug formation time in the rabbit mesenteric microcirculation as did heparin. Formation of ex vivo Chandler thrombi was significantly inhibited. The practical interest of the substance comes from the combination of an antithrombotic effect and little influence on primary haemostasis.     

Modulation of tissue fibrinolysis from hypoxia and hyperoxia

The effects from alterations in inspired oxygen tension on the fibrinolytic activity in vessel walls was studied in rats. Tissue plasminogen activator activity was measured semiquantitatively with the histochemical technique. During severe hypoxic conditions (FIO2 = 0.05) the fibrinolytic activity in the aorta was significantly reduced as compared to control animals. At 24 hours with slightly higher oxygen tension (FIO2 = 0.08) the activity was increased. When breathing pure oxygen (FIO2 = 1.0) the fibrinolytic activity was increased in the aorta after 8 hours. Following chronic hypoxia for 6 weeks (FIO2 = 0.1) the activity in the caval vein was increased. Changes in inspired oxygen tension thus affected the endothelial cells and changed their expression of plasminogen activator activity.