Drag and Torque on Clusters of N Arbitrary Spheres at Low Reynolds Number.

Hydrodynamics of particle clusters suspended in viscous fluids is a subject of considerable theoretical and practical importance. Using a multipole expansion of the flow velocity in a series of spherical harmonics, Lamb's fundamental solution of the Stokes flow outside a single sphere is generalized in this work to the case of N nonoverlapping spheres of arbitrary size with slip boundary conditions. The expansion coefficients are found by transforming the boundary conditions to the Lamb form and by transforming the spherical coordinates and solid spherical harmonics centered at different spheres.

[Catheterization of the subclavian vein in patients with combined trauma in emergency situations].

The authors describe a simplified method of catheterization of the subclavian vein available in all medical institutions and in any situation.

Inhibition of potassium and calcium currents in neurones by molecularly-defined P2Y receptors.

Messenger RNAs and cDNAs for individual cloned P2Y(1), P2Y2 and P2Y(6) nucleotide receptors have been expressed by micro-injection into dissociated rat superior cervical sympathetic neurones and the effects of stimulating the expressed receptors on voltage-activated N-type Ca(2+) currents and M-type K(+) currents recorded. Both currents were reduced by stimulating all three receptors, with the following mean IC(50) values: P2Y(1) (agonist: ADP) - I(K(M)) 6.9 nM, I(Ca) 8.

The P2Y(1) receptor closes the N-type Ca(2+) channel in neurones, with both adenosine triphosphates and diphosphates as potent agonists.

The rat P2Y(1) nucleotide receptor, the P2Y subtype abundant in the brain, was heterologously expressed in rat superior cervical ganglion neurones by micro-injection of the receptor cRNA or cDNA. ADP inhibited the N-type Ca(2+) current by 64%, with EC(50) 8.2 nM, an action blocked competitively by the P2Y(1) receptor antagonist adenosine 3', 5'-bis-phosphate (K(i) 0.

Dual coupling of heterologously-expressed rat P2Y6 nucleotide receptors to N-type Ca2+ and M-type K+ currents in rat sympathetic neurones.

1. The P2Y6 receptor is a uridine nucleotide-specific G protein-linked receptor previously reported to stimulate the phosphoinositide (PI) pathway. We have investigated its effect in neurones, by micro-injecting its cRNA into dissociated rat sympathetic neurones and recording responses of N-type Ca2+ (I(Ca(N))) and M-type K+ (I(K(M))) currents.

[The functional results of abdomino-anal resection of the rectum with the formation of a reservoir from the large intestine].

Under study were clinical and functional results of 27 patients aged 36 to 68 years with adenocarcinoma (pT2-T3) of the ampullar part of the rectum who were submitted to abdomino-anal resection with the formation of J-shaped colonic reservoir. In the nearest postoperative period partial incompetence of the coloanal anastomosis, necrosis of the reservoir wall and its inflammation appeared in 4 patients. In 6 months after closure of the protective transversostomy full continence was noted in 24 patients.

Crystallization of poly(ethylene oxide) confined in pores of active carbon.

The kinetics of isothermal crystallization of poly(ethylene oxide) confined in pores of active carbon was studied by nuclear magnetic resonance relaxation. At equal temperatures the induction period of crystallization in pores differs from that in the bulk polymer. A model was developed that allows estimation of the effect of porous media on the statistical sum of the macromolecule considering the change of the polymer chain conformation in the melt.

Crystallisation of crystallizable and amorphous polymer mixtures and peculiarities of their structure: an NMR study.

After isothermal crystallization of the crystallizable poly(ethylene oxide)/amorphous poly(propylene oxide) mixture, partially crystalline structures were formed. They present a specific heterogeneous medium with a hard frame composed of the crystal phase. The isothermal crystallization of the mixture and molecular self-diffusion processes in the amorphous phase of the crystallized mixture was studied by nuclear magnetic resonance relaxation and nuclear magnetic resonance (NMR) with pulsed field gradient.

Intracellular retention of recombinant GABAB receptors.

gamma-Aminobutyric acid type B (GABAB) receptors mediate the transmission of slow and prolonged inhibitory signals in the central nervous system. Two splice variants of GABAB receptors, GABABR1a and GABABR1b, were recently cloned from a mouse cortical and cerebellar cDNA library. As predicted, these receptors belong to the G protein-coupled receptor superfamily.

P2Y2 nucleotide receptors expressed heterologously in sympathetic neurons inhibit both N-type Ca2+ and M-type K+ currents.

The P2Y2 receptor is a uridine/adenosine triphosphate (UTP/ATP)-sensitive G-protein-linked nucleotide receptor that previously has been reported to stimulate the phosphoinositide signaling pathway. Messenger RNA for this receptor has been detected in brain tissue. We have investigated the coupling of the molecularly defined rat P2Y2 receptor to neuronal N-type Ca2+ channels and to M-type K+ channels by heterologous expression in rat superior cervical sympathetic (SCG) neurons.

Inhibition by heterologously-expressed P2Y2 nucleotide receptors of N-type calcium currents in rat sympathetic neurones.

The P2Y2 nucleotide receptor has previously been shown to stimulate phosphoinositide breakdown. We now show that, when P2Y2 receptors are heterologously expressed by cRNA injection into dissociated rat sympathetic neurones, activation of these receptors by uridine 5'-triphosphate (UTP) or adenosine 5'-triphosphate (ATP) inhibits the N-type voltage-gated calcium current by approximately 65%, with an IC50 of 0.5 microM.

[Prevalence of IS285 and IS100 in Yersinia pestis and Yersinia pseudotuberculosis genomes].

Cell DNAs of various species of Enterobacteriaceae were hybridized with the probes based on IS285 and IS100, mobile genetic elements of Yersinia pestis. These IS elements are found only in the genomes of all tested Y. pestis strains and a number of strains of a related bacterium Y.

Identification and characterization of a leukocyte-specific component of the nuclear body.

The nuclear body (NB) is a cellular organelle that is involved in the pathogenesis of acute promyelocytic leukemia and viral infection. The NB is also a target of antibodies in the serum of patients with the autoimmune disease primary biliary cirrhosis. In this study, serum from a patient with primary biliary cirrhosis was used to identify a cDNA encoding a novel component of the NB, a 140-kDa protein designated Sp140.

Activation of nucleotide receptors inhibits high-threshold calcium currents in NG108-15 neuronal hybrid cells.

Unlabelled: A P2U (UTP-sensitive) nucleotide receptor has previously been cloned from NG108-15 neuroblastoma x glioma hybrid cells and it has been shown that activation of this receptor inhibits the M-type K+-current. We now report that UTP also inhibits Ca2+-currents in differentiated NG108-15 cells, but probably through a different nucleotide receptor. UTP (100 microM) inhibited the peak of the high-threshold current by 28.

M-type K+ current inhibition by a toxin fron the scorpion Buthus eupeus.

A number of invertebrate venoms have been tested for effects on M-type K+ currents (IK(M)) in differentiated mouse neuroblastoma X rat glioma NG108-15 cells. Among the venoms tested, Buthus eupeus scorpion venom reversibly inhibited IK(M) by approximately 44% at 50 microgram/ml. Inhibition was not due to activation of bradykinin or nucleotide (pyrimidine) receptors.

[The diagnosis and treatment of Dieulafoy's syndrome].

Dieulafoy's lesion is one of numerous causes of acute gastrointestinal bleedings. A prospective study of the Dieulafoy lesion were carried out from 1989 till 1995. Under study there were 8 patients.

[Aerospace toxicology: basic stages of formation and prospects of development].

The review shows the basic stages of development of aerospace toxicology. It traces the way of forming this research direction from its origin to the present day. Study methods are being improved as practical tasks are becoming more intricate.

[Tuberculin-BCG therapy in combined treatment of patients with pulmonary tuberculosis].

The efficacy of combined use of tuberculin and BCG vaccine (tuberculin-BCG-therapy) given to 70 patients with new-onset and recurrent pulmonary tuberculosis was compared to that of BCG treatment only received by 24 patients. Bacterial discharge and caverns were registered in 80 and 78 patients, respectively. 25 patients underwent stimulating, 37, 8 paradoxical tuberculin-BCG-therapy.