The surface and interfacial tensions of pure liquids and surfacttant solutions can be measured using a variety of techniques including the drop volume method (see Figure) and the ring or plate method. The various methods are briefly discussed and an automated version of the drop volume method which reliably produces results of the highest quality presented.

Species of the genus Epilobium (Onagraceae) have been investigated for their activity against 5 alpha-reductase and aromatase, two enzymes which are involved in the aetiology of benign prostatic hyperplasia (BPH). Activity-guided fractionation has led to the identification of two macrocyclic ellagitannins, oenothein A (1) and oenothein B (2), as the main constituents responsible for the inhibition of the two enzymes. Quantitation of oenothein B in 10 different species of Epilobium has shown that amounts of up to 14% in the crude plant extracts are possible.

Remarkable elevation of the serum potassium concentration without associated manifestations of hyperkalemia was observed in a patient with an unexplained increase in the blood platelets (1). Studies of the phenomenon in this patient indicated that the excess of potassium was derived from the platelets during the coagulation of the blood. Hyperkalemia was encountered in certain other patients with thrombocytosis. In contrast, no striking elevation of the serum potassium concentration was observed when normal platelets were concentrated in vitro. METHODS AND MATERIALSPreparation of native blood and plasma specimens. Native (without anticoagulant) blood and plasma specimens were processed by previously described methods with reliance on the use of low temperatures and siliconetreated 2 equipment (2, 3). Platelet-free plasma was prepared from the blood specimen only after prior separation of platelet-rich plasma.Preparation of acid-citrate-dextrose plasma. Acidcitrate-dextrose3 (ACD) solution was added to whole blood prior to centrifugation in the proportion of one part of the anticoagulant to four parts of blood.Isolation of platelets. Blood (300 to 500 ml.) was collected from an antecubital vein into silicone-treated tubes packed in an icebath. Saftidonor4 sets were used for the collection of the blood in order to minimize trauma and exposure to surfaces such as occurs when blood is collected by multiple syringe technique. The blood was processed with and without the use of ACD anticoagulant. Native (without anticoagulant) and ACD plateletrich plasmas were prepared by slow speed centrifugation (1,500 to 2,000 rpm) in a refrigerated Servall angle centrifuge. A viscid plug of platelets was isolated from platelet-rich plasma by centrifuging at higher speeds (12,000 rpm). The supernatant plasma was thoroughly removed by draining and wiping the inside of the tube carefully. The platelet plug was placed in a deep-freeze. A small red button (red cells) was noted on the bottom of the platelet plug. In order to obtain a plug free of red and white cells, the red button with a small portion of the adjacent whitish material was removed while the plug was in a frozen state. The material removed was estimated to be less than 2 per cent of the volume of the plug.The platelet plug isolated from a measured volume of platelet-rich plasma was weighed and its volume determined by centrifugation in a graduated centrifuge tube. Platelet water was determined by allowing the wet plugs to reach constant weight by drying in an oven set at 800 C.Blood counts. Platelet counts were performed in duplicate by the phase microscopy method of Brecher and Cronkite (4). Counts on undiluted platelet-free plasma and serum were performed as previously described (3). Red and white blood cell counts on platelet-rich and platelet-free plasma and on serum were performed in the routine manner, using appropriate pipet dilutions.Potassium concentrations in serum, plasma and platelets. Native whole blood or plasma was placed in silicone-treated tubes for one h...

No abstract

The (E)-2-(4-pyridylmethylene)-1-tetralones 1-7 (1, H; 2, 5-OCH3; 3, 6-OCH3; 4, 7-OCH3; 5, 5-OH; 6, 6-OH; 7, 7-OH) were obtained by aldol condensation of the corresponding 1-tetralones with 4-pyridinecarboxaldehyde, and in the case of the OH compounds 5 and 7 subsequent ether cleavage of the OCH3-substituted 2-(4-pyridylmethylene)-1-tetralones. Catalytic hydrogenation of 1-4 gave the 2-(4-pyridylmethyl)-1-tetralones 8-11 (8, H; 9, 5-OCH3; 10, 6-OCH3; 11, 7-OCH3). Subsequent ether cleavage of 9-11 led to the corresponding OH compounds 12-14 (12, 5-OH; 13, 6-OH; 14, 7-OH). The enantiomers of 11 and 12 were separated semipreparatively by HPLC on triacetylcellulose. All compounds (1-14) showed an inhibition of human placental aromatase exhibiting relative potencies from 2.2 to 213 [compounds 6 and (+)-12, respectively; aromatase inhibitory potency of aminoglutethimide (AG) = 1]. The compounds exhibited no or only a weak inhibition of desmolase [cholesterol side chain cleavage enzyme; maximum activity shown by 12, 23% inhibition (25 microM); AG, 53% inhibition (25 microM)]. In vivo, however, the compounds were not superior to AG as far as the reduction of the plasma estradiol concentration and the mammary carcinoma (MC) inhibiting properties are concerned (PMSG-primed SD rats as well as DMBA-induced MC of the SD rat, pre- and postmenopausal experiments, and the transplantable MXT-MC of the BD2F1 mouse). This is due to a fast decrease of the plasma E2 concentration inhibiting effect as could be shown by a kinetic experiment. In addition, select compounds inhibited rat ovarian aromatase much less than human placental aromatase (12, factor of 10). Estrogenic effects as a cause for the poor in vivo activity of the test compounds could be excluded, since they did not show affinity for the estrogen receptor.