A Technique for Testing the Si Tracker Modules for the D0 Collider Experiment (FNAL) and Comparative Analysis of the Test Results

The Skobel'tsyn Institute of Nuclear Physics (SINP) of Moscow State University participates in the development of a silicon tracker for the D0 experiment (FNAL, USA). The SINP specialists were engaged in assembling and testing of the end-disc detectors for the tracker. A technique for testing the disc modules is described, and the test results are presented. They are compared to the disc-detector parameters and measured before the assembling. This comparison can be used to create test procedures and the detector-selection criteria in the development of large-sized tracking systems on the basis of single-sided microstrip detectors.     

Effects of ethanol consumption on brown adipose tissue thermogenic capacity in mice

The objective of this work was to evaluate the effects of ethanol consumption on brown adipose tissue (BAT) thermogenic capacity in mice. Mice offered only ethanol (10%; v/v) for 10 days as drinking fluid had significant reductions in total energy and fluid intakes relative to mice given water, but net weight gains were similar. BAT thermogenic capacity was reduced in mice drinking ethanol, as shown by decreases in tissue protein and succinate dehydrogenase (SDH) activity and in the uncoupling protein content of isolated mitochondria. Ethanol consumption differed greatly between mice offered a choice between ethanol and water for 25 days after a 10-day habituation period, with only ethanol as the drinking solution. Total energy intake of mice that continue to consume the most ethanol voluntarily (up to 25% of total fluid intake) was significantly reduced but carcass fat was increased, relative to mice consuming less or no ethanol. Brown fat thermogenic capacity was not significantly affected by the degree of ethanol consumption. Basal and norepinephrine-stimulated rates of oxygen uptake of isolated brown adipocytes were not affected by ethanol. Thus, changes in the animal capacity for energy expenditure in brown adipose tissue does not appear an important factor to explain the effects of ethanol consumption on fat deposition in mice.     

A novel MspI PCR-RFLP in the human cytosine 5-methyltransferase gene: lack of relevance for malignant lymphoproliferative disease and breast cancer

A 72 year-old man underwent a Bentall procedure for aortic regurgitation secondary to annulo-aortic ectasia and ascending aortic aneurysm. On the 11th postoperative day, the C-reactive protein (CRP) level and white blood cell (WBC) count rose. Echocardiography and a computed tomographic scan showed the appearance of pericardial effusion. A diagnosis of mediastinitis and composite graft infection was made, and mediastinal drainage and irrigation were performed. Methicillin-resistant coagulase negative staphylococcus (MRCNS) was identified as the causative organism. Vancomycin, arbekacin and minocycline were used intravenously. Additionally, a continuous mediastinal irrigation was performed through the chest tubes. CRP level and WBC count were gradually reduced to normal range. He has now been free from signs of infection for more than 3 years. Because MRCNS is considered less virulent than methicillin-resistant Staphylococcus aureus, mediastinitis and composite graft infection due to MRCNS might be treatable by such conservative therapy even in patients with prosthetic implants. Since MRCNS often becomes ubiquitous, preventing infections by strict attention to asepsis is important.     

Microfabricated microneedles: a novel approach to transdermal drug delivery

Although modern biotechnology has produced extremely sophisticated and potent drugs, many of these compounds cannot be effectively delivered using current drug delivery techniques (e.g., pills and injections). Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. Because the primary barrier to transport is located in the upper 10-15 micron of skin and nerves are found only in deeper tissue, we used a reactive ion etching microfabrication technique to make arrays of microneedles long enough to cross the permeability barrier but not so long that they stimulate nerves, thereby potentially causing no pain. These microneedle arrays could be easily inserted into skin without breaking and were shown to increase permeability of human skin in vitro to a model drug, calcein, by up to 4 orders of magnitude. Limited tests on human subjects indicated that microneedles were reported as painless. This paper describes the first published study on the use of microfabricated microneedles to enhance drug delivery across skin.     

Synthesis of a copolymer of acrylonitrile with sodium methallylsulfonate in dimethyl sulfoxide and the preparation of a chemisorptive fibre based on it

Conclusions Conditions have been developed for the synthesis of a copolymer of acrylonitrile and sodium methallylsulfonate in dimethyl sulfoxide containing up to 2–1/2% water by wt., using a redox initiating system.Fibres spun from the indicated copolymer have satisfactory physico-mechanical properties, and their static exchange capacity is as much as 1.1 meq/g.Translated from Khimicheskie Volokna, No. 4, pp. 16–18, July–August, 1990.     

Oscillations of two competing microbial populations in configurations of two interconnected chemostats

It is known that, when two microbial populations competing for a single rate-limiting nutrient are grown in a spatially uniform environment, such as a single chemostat, with competition being the only interaction between them, they cannot coexist, but eventually one of the two populations prevails and the other becomes extinct. Spatial heterogeneity has been suggested as a means of obtaining coexistence of the two populations. A configuration of two interconnected chemostats is a simple model of a spatially heterogeneous environment. It has been shown that, when Monod's model is used for the specific growth rates of the two populations, steady-state coexistence can be obtained in such systems for wide ranges of operating conditions. In the present work, we study a model of microbial competition in configurations of interconnected chemostats and we show that, if a substrate inhibition model is used for the specific growth rates of the two populations, coexistence in a periodic state is also possible. The analysis of the model is done by numerical bifurcation theory methods.     

Multiple splice variants of phosphodiesterase PDE4C cloned from human lung and testis

Four closely related cyclic-nucleotide specific phosphodiesterase (PDE4) genes have been identified in both humans and rats: PDE4A, 4B, 4C and 4D. We have now cloned cDNAs for multiple splice variants of human PDE4C. Two splice variants, PDE4C-791 and PDE4C-426, were isolated from a fetal lung library. The longest open reading frame (ORF) of 791 amino acids (aa) is encoded by PDE4C-791, which is similar to a recently described cDNA [Engels, P., Sullivan, M., Muller, T. and Lubbert, H. FEBS Lett. 358 (1995) 305-10], except that an alternative 5'-end sequence upstream of the first methionine extends the PDE4C-791 ORF by 79 aa. The PDE4C-426 variant contains 3 insertions that are located 5' to the catalytic domain and encode several in-frame stop codons. The predicted 426 aa protein initiates at a methionine 365 aa within PDE4C-791. A baculovirus clone starting at this methionine expressed an enzymatically active protein. Two additional splice variants, PDE4C-delta54 and PDE4C-delta109, were found in testis mRNA. PDE4C-delta54 contained a novel 5'-end region and a deletion of 162 nt; the predicted protein deletes 54 aa from the amino-terminal region. The PDE4C-delta54 protein produced in baculovirus-infected cells was enzymatically active and sensitive to PDE4-specific inhibitors. The PDE4C-delta109 protein is similar to PDE4C-delta54 but has an additional 55 aa deleted in the catalytic domain; it lacked enzymatic activity. Analysis of uncloned total mRNA from 4 tissue sources by polymerase chain reaction (PCR) confirmed the presence of mRNAs with the two deletions and three insertions that we observed in cDNA clones. The PDE4C-delta54 variant was found only in testis and the 5'-extended region of PDE4C-791 was seen only in lung and the melanoma cell line G361. Hence, tissue-specific expression of various PDE4C isoforms should be considered in understanding how these gene products modulate cellular responses to cAMP.