Influence of cholesterol and prostaglandin E1 on the molecular organization of phospholipids in the erythrocyte membrane. A fluorescent polarization study with lipid-specific probes.

Anthryl-labeled fluorescent probes closely mimicking phosphatidylcholine and sphingomyelin were applied to study the state of these phospholipids in the rabbit erythrocyte membrane. At normal cholesterol levels both probes exhibited higher fluorescence polarization values in the membranes than in phospholipid vesicles of similar lipid composition, indicating a decreased fluidity of the probe environment in erythrocyte ghosts. In ghosts prepared from normal erythrocytes no evidence of lateral separation of phosphatidylcholine and sphingomyelin was found. At higher cholesterol levels, however, these lipids appear to segregate. Probably the effect of cholesterol on the erythrocyte membrane lipids involves lipid-protein interactions. At physiological concentrations, prostaglandin E1 only weakly affects the state of phosphatidylcholine and sphingomyelin in erythrocyte membranes. Cholesterol enrichment amplifies the effect of prostaglandin E1. Although the prostaglandin E1-induced changes depended much upon whether the ghosts were enriched with cholesterol in vitro or in vivo, with both types of ghosts effects of prostaglandin E1 were seen at extremely low effector concentrations that may have presented a few molecules of prostaglandin per ghost. The structural and functional significance of these findings is discussed.

1/f frequency noise of 2-GHZ high-Q thin-film sapphire resonators.

We present experimental results on intrinsic 1/f frequency modulation (FM) noise in high-overtone thin-film sapphire resonators that operate at 2 GHz. The resonators exhibit several high-Q resonant modes approximately 100 kHz apart, which repeat every 13 MHz. A loaded Q of approximately 20,000 was estimated from the phase response. The results show that the FM noise of the resonators varied between Sy (10 Hz) = -202 dB relative (rel) to 1/Hz and -210 dB rel to 1/Hz. The equivalent phase modulation (PM) noise of an oscillator using these resonators (assuming a noiseless amplifier) would range from [symbol: see text](10 Hz) = -39 to -47 dBc/Hz.

[Study of the effect of various intermediate products and enzymes of carbohydrate metabolism on erythrocyte aggregation]. / Issledovanie vliianiia nekotorykh promezhutochnykh produktov i fermentov uglevodnoto obmena na agregatsiiu éritrotsitov.

The effect of some substances on the aggregation of red blood cells induced by gamma-globulin and fibrinogen was studied in vitro. Fructose 1,6-diphosphate, glucose 6-phosphate, glyceraldehyde dehydrogenase, insulin and prostaglandin E1 inhibited aggregation of red cells. Glucose, glucose 1,6-phosphate and ACTH had different effects in various concentrations on red cell aggregation, while fructose, prednisolon and D-oxy-prostaglandin E1 alpha and E1 beta caused no effect.

[Changes in the level of polyunsaturated fatty acids, substrates and inhibitors of thromboxane and prostacyclin synthesis, in the blood of patients with cardiovascular diseases]. / Izmenenie urovnei polinenasyshchennykh zhirnykh kislot--substratov i ingibitorov sinteza tromboksana i prostatsiklina--v plazme krovi cheloveka pri serdechno-sosudistykh zabolevaniiakh.

The authors examined the ratios of blood free polyunsaturated fatty acids (PUFA), such as 20:3n6, 20:4n6, 20:5n3, and 22:6n3, which are substrates and inhibitors of synthesis of thromboxane A2 and prostacyclins that regulate both normal blood fluidity, and platelet adhesion and primary thrombogenesis. The object of the study was plasma from healthy subjects and 4 groups of patients with cardiovascular diseases: 1) large myocardial infarction; 2) resting and exercise-induced angina pectoris; 3) large myocardial infarction; and 4) recurrent myocardial infarction. The levels of plasma free PUFA were measured by gas chromatography. Assessment of the PUFA ratios indicated that the risk for thrombogenesis increased in large and recurrent myocardial infarctions as compared to small myocardial infarction and angina pectoris both by reducing the relative levels of 20:3n6 and, in particular, 20:5n3, substrates of synthesis of only thrombolytics and vasodilators and by more greatly inhibiting the synthesis of prostacyclins than thromboxane with elevated 22:6n3 levels.

[The effect of fluorinated prostaglandins on platelet aggregation]. / Vliianie ftorirovannykh prostaglandinov na agregatsiiu trombotsitov.

The effects of fluorodeoxy prostanoids on platelet aggregability were studied. It was shown that introduction of fluorine into positions 9, 11 or 15 of prostaglandin F2 alpha led to enhanced proaggregation activity. The most active compound among fluorodeoxy analogs was 15-fluoro derivative; bisfluoro analog was moderately active, and 11-fluoro compound had the least activity. In the group of fluorodeoxy prostaglandins E2, a contrary effect was registered. Thus, the most active compound was 1-fluoride and the least, 15-fluoride. The incorporation of fluorine into position 15 of prostacyclin led to insignificantly lower antiaggregatory activity just as this modification of 6-keto-prostaglandin F1 alpha was accompanied by a dramatic increase in its ability to inhibit platelet aggregation.

[Hemostatic potential during the development of post-mastectomy edema]. / Gemostaticheskii potentsial pri razvitii postmastéktomicheskogo oteka.

The work deals with the study of the mosaic character of the hemostatic potential, connected with the development of a localized pathological process, taking postmastectomy edema in illustration. It is shown that this condition is an example of the manifestation of the RASK system mosaics in one organism in pathology. It should be pointed out that the degree of the development of the local DVS syndrome changes significantly some of the RASK system parameters at the level of the whole organism. This is evidence that normalization of the microcirculatory processes in the edematous extremity will be an important measure in complex treatment of postmastectomy edema. It will considerably lower the risk of general disorders of the RASK system. Parameters determined in the blood collected from the extremity on the side of the operation will serve as controls of the efficacy of the applied therapeutic measures.