bluuebunny/crossref_metadata_2025_split huggingface dataset:
Burst testing of condoms. I. Basic features of the force‐deformation curve of latex‐rubber condoms
Authors: Wilson T. W. , Andrady A. L. 
Published: May 2005

AbstractInflation of a rubber condom involves biaxial deformation of the material which can be modeled by the use of an appropriate strain‐energy function. Force versus deformation data for uniaxial extension of strips of condoms were used to determine the parameters for Ogden's form of a strain‐energy function. These parameters were then used to fit experimentally obtained burst test data to a stress‐strain equation formulated for inflation of condoms in a burst test. Experimental data on inflation of condoms agree well with theoretical curves verifying the applicability of the biaxial stress‐strain equation to the particular strain‐energy function on which it is based.
Distribution of bacterial cells within fibrous air sterilization filters
Authors: Aiba Shuichi , Yamamoto Akira 
Published: May 2005

AbstractApplying radio‐isotope 32P, the distribution of bacterial cells retained within glass‐fibre air sterilization filters was measured. In particular, the time‐dependence of the radial as well as the longitudinal distribution was studied. The collection efficiency of glass‐fibre was obtained and the experimental result was compared with a theoretical value based upon the sum of interception, inertia and diffusion. Discrepancies could not be accounted for and are similar to those in the literature. An equation was proposed for the estimation of air filter life. This was not completely verified but leads to some suggestive results.
Composition of a domestic sewage
Authors: Painter H. A. , Viney M. 
Published: May 2005

AbstractAn analysis of the organic constituents of whole, domestic sewage was made by analysing four physically separated fractions. Settlement, centrifuging and filtration were used to obtain one liquid and three solid fractions. Concentration of the filtrate was achieved by freeze‐drying with only minor changes in composition. The average concentration of organic carbon in fresh, whole domestic sewage was 310 p.p.m., of which about 70 per cent was in suspension. Eight classes of compounds were found, on analysis, to comprise about 75 per cent of the organic carbon in whole sewage and of the soluble organic carbon 80 per cent was distributed between five groups. Using chromatographic methods the concentrations of four volatile acids were determined and the presence of other acids was detected. Similarly, seven of the soluble sugars and eight present in hydrolysed suspended solids have been identified. The probable nature of some of the compounds unaccounted for is discussed.
An attempt to determine discriminate use of hydrogen isotopes by bacteria
Authors: Linday E. Margery , Syrett P. J. 
Published: May 2005

AbstractThe hydrogenase system of Hydrogenomonas facilis could be induced by either hydrogen or deuterium and the rate of deuterium uptake by the induced cells was the same as that of hydrogen.An attempt has been made to detect discriminate use of hydrogen and deuterium by bacteria. No discrimination could be detected during hydrogenation of methylene blue by Escherichia coli, under the experimental conditions.
Mass propagation of algae for photosynthetic gas exchange
Authors: Gaucher Thomas A. , Benoit Richard J. , Bialecki Adolph 
Published: May 2005

AbstractEngineering data on the design and operation of algal culture systems for photosynthetic gas exchange are virtually non‐existent. The authors have conducted intermediate and definitive level engineering studies to characterize algal systems—with a view to extrapolating to larger‐scale systems for life support in closed spaces.Light intensity, carbon dioxide concentration, and dilution rate were the principal parameters used to control the photosynthetic rate and, consequently, oxygen production. Carbon dioxide absorption rate, equilibrium density, and cellular growth rate were also investigated.It was found that: (1) properly jacketed high intensity, incandescent lamps provided a suitable light source for growing algae; and (2) physiologically safe (0·5 per cent) concentrations of carbon dioxide produced growth comparable to that obtained at higher concentrations.A dilution rate of nearly 0·1 volume change per hour produced the best oxygen yield (2·41 × 10−3 lb/h) for the definitive system. Maximum cell doubling time was 5·1 h. The highest culture density attained was 5·9 mm3/ml, and the maximum dry weight algae yield was 3·0 × 10−3 lb/h.
The disintegration of yeast with dry ice and some properties of the extract
Authors: v. Hofsten Bengt , Tjeder Anders 
Published: May 2005

AbstractA simple procedure for the disintegration of yeast cells, by which litre quantities of cell extract (approximately 11 per cent dry weight) may be obtained, is described. The fresh yeast cake is treated with dry ice in a high speed electric homogenizer after which it is left to thaw out at 0°. No addition of buffer has to be made, and the cell juice obtained after centrifugation of the resulting slurry appears to contain different subcellular particles and various enzymes in a relatively native state.When the extract is incubated at higher temperatures, proteolysis will rapidly change the electrophoretic and enzymatic properties, which indicates that procedures involving autolysis may be dangerous when information about the chemical composition of the native enzymes is desired.
Die technische Herstellung von klinischem dextran durch gelenkte synthese in wachsender Kultur
Authors: Behrens U. , Ringpfeil M. , Brückner D. , Fröhlich M. , Krüger K. , Thiel H. , Torporski W. 
Published: May 2005

AbstractA process is described for the production of a specific‐molecular‐weight dextran, e.g. clinical dextran, by using a modified form of controlled synthesis. The synthesis is carried out directly in a medium containing appropriate amounts of sucrose and low‐molecular‐weight dextran after inoculation with a culture of actively growing bacteria. The importance of an inoculum substantially freed from substances affecting the synthesis of dextran is demonstrated. The technique appears to offer a decided advantage over other well‐known procedures. Technical details of the process and equipment are given.
Volume increase of wheat kernels accompanying absorption of liquid water
Authors: Chung Do Sup , Fan Liang‐Tseng , Shellenberger John A. 
Published: May 2005

AbstractThe purposes of this investigation were to determine the relationship between weight and volume increases which take place when wheat kernels are immersed in water, to develop an equation for the volume increase, and to test experimentally its validity.It was shown that the volume increase was practically equal to the weight increase divided by the fluid density. In view of this, the following equation was obtained by analogy to the diffusion equation derived by Becker.1

where 1 − V̄ is the relative volume increase, and Dv is the coefficient of volume increase.The average coefficients of volume increase are given by the Arrhenius relation as:

The results obtained in this investigation provide useful information for designing the steeping vessels.
Differential repair and replication of damaged DNA in ribosomal RNA genes in different CHO cell lines
Authors: Wauthier Eliane L. , Hanawalt Philip C. , Vos Jean‐Michel H. 
Published: May 2005

AbstractWe studied the repair of psoralen adducts in the pol I–transcribed ribosomal RNA (rRNA) genes of excision repair competent Chinese hamster ovary (CHO) cell lines, their UV sensitive mutant derivatives, and their UV resistant transformants, which express a human excision repair gene. In the parental cell line CHO‐AA8, both monoadducts and interstrand crosslinks are removed efficiently from the rRNA genes, whereas neither adduct is removed in the UV sensitive derivative UV5; removal of both adducts is restored in the UV resistant transformant CHO‐5T4 carrying the human excision repair gene ERCC‐2. In contrast, removal of psoralen adducts from the rRNA genes is not detected in another parental CHO cell line CHO‐9, neither in its UV sensitive derivative 43°3B, nor in its UV resistant transformant 83°G5 carrying the human excision repair gene ERCC‐1. In contrast to such intergenomic heterogeneity of repair, persistence of psoralen monoadducts during replication of the rRNA genes occurs equally well in all CHO cell lines tested. From these data, we conclude that: (1) The repair efficiency of DNA damage in the rRNA genes varies between established parental CHO cell lines; (2) the repair pathways of intrastrand adducts and interstrand crosslinks in mammalian cells share, at least, one gene product, i.e., the excision repair gene ERCC‐2; (3) replicational bypass of psoralen monoadducts at the CHO rRNA locus occurs similarly on both DNA strands.
In vitro depolymerization dynamics of brain endogenous microtubules
Authors: López Luis A. , Mayorga Luis S. , Bertini Francisco 
Published: May 2005

AbstractA subcellular fraction containing fragments of endogenous microtubules stabilized in 50% glycerol was separated by diferential centrifugation of rat brain homogenates. The pellets were suspended in glycerol‐deficient media, and microtubule depolymerization was monitored by measuring the decrease of sedimentable tubulin. Concomitantly, the number and size of microlubules in the suspensions were followed via electron microscopy. Depolymerization was accompanied by a proportional decrease in the number of microtubules, whereas the average size did not change significantly. After approximately 20 min, a subpopulation of microtubules became stable and did not suffer further depolymerization. These results indicate that upon dilution some microtubules completely depolymerize, whereas others remain stable in the glycerol‐deficient medium. The degree of depolymerization depended on both the volume of the resuspension media and on the final glycerol concentration. The results suggest that the depolymerization of the remaining microtubules is prevented by stabilizing factors released from depolymerizing microtubules. Tubulin dimers are not one of these factors, since depolymerization was not altered by the addition ofcolchicine or by changing the concentration of free tubulin in the medium.
Retransformation of a revertant cell line with the adenovirus E1 oncogenes and vanadate
Authors: Dessureault Jean , Weber Joseph M. 
Published: May 2005

AbstractWe have isolated a revertant cell line (G5) from an adenovirus transformed rat cell line (F4) which failed to express the integrated viral oncogenes. To determine whether the reversion mutation was acting in cis or trans the G5 cells were co‐transfected with an E1 gene bearing expression plasmid and a neomycin photransferase bearing plasmid. 0418‐resistant colonies were picked and shown to express the E1 proteins and to be tumorigenic. This re‐transformation could be partially mimicked by treatment with vanadate, an inhibitor of phosphotyrosine phosphatases. These results show that the continued presence of the E1 proteins was required to maintain the transformed phenotype, and that the reversion mutation was a cis‐acting event affecting directly the integrated E1 genes.
Clustering of sequential enzymes in the glycolytic pathway and the citric acid cycle
Authors: Beeckmans Sonia , Van Driessche Edilbert , Kanarek Louis 
Published: May 2005

AbstractIn recent years, evidence has been accumulating that metabolic pathways are organized in vivo as multienzyme clusters. Affinity electrophoresis proves to be an attractive in vitro method to further evidence specific associations between purified consecutive enzymes from the glycolytic Pathway on the one hand, and from the citric acid cycle on the other hand. Our results support the hypothesis of cluster formation between the glycolytic enzymes aldolase, glyceraldehydephosphate dehy‐drogenase, and triosephosphate isomerase, and between the cycle enzymes fumarase, malate dehydrogenase, and citrate synthase. A model is presented to explain the possibility of regulation of the citric acid cycle by varying enzyme‐enzyme associations between the latter three enzymes, in response to changing local intramitochondrial ATP/ADP ratios.
Exposure of perfused liver to hypotonic conditions modifies cellular nitrogen metabolism
Authors: Häussinger D. , Lang F. 
Published: May 2005

AbstractIsolated livers were exposed to hypotonic perfusates. As shown previously, this hypotonic challenge leads to initial cell swelling, followed by volume regulatory ion fluxes, largely restoring cell volume within approximately 6 min. However, the hepatocyte is left in an altered metabolic state, which is characterized by marked stimulation of hepatic glutamine uptake and degradation and transient release of glutamate from the liver. Urea formation from glutamine and alanine is stimulated, whereas hepatic ammonia uptake and utilization for urea and glutamine synthesis decreases. These observations reveal a hitherto unrecognized factor modulating hepatic function during intestinal absorption.
Protein synthesis in embryonic tissues during mouse postimplantation development
Authors: Murach Karl‐Friedrich , Frei Monika , Gerhäser Dieter , Illmensee Karl 
Published: May 2005

AbstractMouse embryos of the NMRI strain between the 7th and 9th day of gestation were isolated from the uterus and dissected into the various tissue derivatives in order to investigate newly synthesized proteins during morphogenesis. The day 7 embryo was fragmented into trophoblast and ectoplacental cone, distal and proximal endoderm, extraembryonic and embryonic ectoderm. The day 8 and day 9 embryos were divided into trophoblast and placental anlage, yolk sac, amnion, and allantois, as well as cranial, central, and caudal embryonic tissue. The intact embryos were incubated in Dulbecco's minimum essential medium in the presence of 35S‐methionine for 4 h, then dissected into the various fragments, and further processed for two‐dimensional gel electrophoresis. Protein synthesis of the isolated tissue derivatives was analyzed and compared for the three developmental stages. Concerning the proteins with isoelectric points in the range of 4.5 to 8.0 and molecular weight ratio (Mr) values between 20,000 and 200,000, we found several significant quantitative and qualitative differences in the various tissue fragments. In addition, we observed further quantitative and qualitative differences in protein synthesis during the postimplantation period investigated. We propose that the differences reflect some of the cell lineage‐ and developmental stage‐specific changes in gene expression during early mammalian differentiation.
Control of expression and maturation of epidermal growth factor receptor
Authors: Das Manjusri , Kesavan Prabakaran , Khire Jayant 
Published: May 2005

AbstractEpidermal growth factor (EGF)‐receptor is a 170 kDa transmembrane glycoprotein that contains a ligand‐binding external domain, and a catalytically active cytoplasmic region. The expression of this receptor as well as a 100 kDa homolog that contains only the external domain is enhanced by the ligand EGF. EGF acts at transcriptional and post‐transcriptional levels. To dissociate these pre‐translational effects and the effects of EGF on receptor polypeptide synthesis from these on receptor export, pulse‐chase experiments were conducted. These studies indicate that EGF stimulates post‐translational transport and processing of the receptor, and this stimulation can occur in the absence of new protein synthesis. Other studies show that EGF accelerates at least two slow events in receptor maturation–the deoxynojirimycin sensitive processing in endoplasmic reticulum (ER) and the swainsonine sensitive processing in Golgi. The results suggest that EGF may influence one or more of the rate determining steps that control receptor export from ER, and this may represent yet another aspect of EGF action that contributes to the positive regulation of EGF‐receptor protein expression.
Monoclonal antibody 425 inhibits growth stimulation of carcinoma cells by exogenous EGF and tumor‐derived EGF/TGF‐α
Authors: Rodeck Ulrich , Williams Noel , Murthy U. , Herlyn Meenhard 
Published: May 2005

AbstractCarcinoma cells frequently coexpress transforming growth factor (TGF)‐α and its receptor, the epidermal growth factor (EGF) receptor, implicating an autocrine function of carinoma‐derived TGF‐α. Using a monoclonal antibody (425) to the EGF‐receptor, we investigated the role of exogenous and tumor cell‐derived EGF/TGF‐α mitogenic activities in proliferation of cell lines derived from solid tumors. Monoclonal antibody 425 was chosen for these studies because it inhibits binding of EGF/TGF‐α to the EGF‐receptor and effectively blocks activation of the EGF‐receptor by EGF/TGF‐α. Seven malignant cell lines originating from carcinomas of colon, pancreas, breast, squamous epithelia, and bladder expressed surface EGF‐receptor and secreted EGF/TGF‐α‐like mitogenic activities into their tissue culture media. All cell lines were maintained in a defined medium free of exogenous EGF/TGF‐α. EGF and TGF‐α added to the culture medium stimulated proliferation of five cell lines to comparable levels. EGF/TGF‐α‐dependent proliferation was significantly reduced by addition of MAb 425 to culture media. In addition, monoclonal antibody 425 reduced proliferation of the five EGF/TGF‐α responsive cell lines in the absence of exogenous EGF/TGF‐α. Antiproliferative effects induced by monoclonal antibody 425 were reversible and could be overcome by addition of EGF to culture media. Our results indicate that tumor‐derived EGF‐receptor‐reactive mitogens can promote proliferation of carcinoma cells in an autocrine fashion.
Biochemical changes associated with the mechanism controlling superoxide radical formation in the aging rotifer
Authors: Sawada Masaaki , Carlson John C. 
Published: May 2005

AbstractLevels of the superoxide radical (SOR) and lipid peroxides were measured and found to increase during aging in the short‐lived rotifer, Asplanchna brightwelli. Life‐span was altered by changes in environmental temperature, absence of light, diet restriction, exposure to ultraviolet radiation, and addition of vitamin E to the diet. Each of the conditions that lengthened life‐span decreased SOR and lipid peroxide levels, and each condition that shortened life‐span increased levels of SOR and lipid peroxides. Additional experiments indicated that on the third day of age, there was a significant increase in Ca2+ uptake and phospholipase A2 activity in membrane samples and an elevation in superoxide dismutase and catalase activity in rotifer homogenates. In addition, SOR concentration was inhibited by the addition of bromophenacyl bromide and indomethacin to membrane samples. By day 5 there was also a significant increase in the lysosomal enzyme, α‐mannosidase. The results of this study indicate that levels of the SOR and lipid peroxides are coupled to rotifer life‐span and that activation of phospholipase A2 may contribute to the elevation of these agents in older animals.
Expression of a 64 kD adipocyte‐specific plasma membrane protein in genetically lean but not obese porcine adipocytes
Authors: Killefer John , Hu C. Y. 
Published: May 2005

AbstractA monoclonal antibody (LA‐1) to an adipocyte‐specific plasma membrane protein (64 kD) was used to examine the differential expression of this protein in genetically lean and genetically obese pigs. Enzyme‐linked immunosorbent assay (ELISA) implied the differential expression of the 64 kD protein in adipocyte plasma membranes having different genetic background. Sodium dodecyl‐sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) of genetically lean, genetically obese, and contemporary subcutaneous adipocyte plasma membranes did not indicate any obvious qualitative differences in protein composition. Corresponding immunoblots utilizing LA‐1 confirmed the presence of the 64 kD protein in contemporary and genetically lean adipocyte plasma membranes but absence in genetically obese adipocyte plasma membranes. LA‐1 labelled intact adipocytes isolated from contemporary and genetically lean adipose tissue but did not react with isolated genetically obese adipocytes. The ability to bind to intact adipocytes indicates that the protein is exposed to the extracellular environment. The migration pattern of the protein was not affected by enzymatic deglycosylation by endoglycosidase‐F suggesting that the protein is not highly, if at all, glycosylated. Presence of the 64 kD protein in genetically lean but not genetically obese adipocyte plasma membranes indicates the identification of a novel adipocyte‐specific surface protein associated, either directly or secondary to the onset of obesity, with genetic predispositions for either genetically lean or obese body types in swine.
Multiple types of mRNA‐cytoskeleton interactions
Authors: Zambetti G. , Fey E. G. , Penman S. , Stein J. , Stein G. 
Published: May 2005

AbstractNearly all actively translated mRNAs are associated with the cytoskeleton in HeLa cells and the nature of this association is poorly understood. To gain insight into this association, we have examined and compared the cytoskeleton‐mRNA interactions of a signal peptide‐histone fusion mRNA (membrane‐bound polysomal mRNA) to those of endogenous histone mRNA (nonmembrane‐bound polysomal mRNA). We report here the detection of a cytoskeleton attachment site within the signal peptide‐histone fusion mRNP/mRNA nucleotide sequence that is not present in wild‐type histone mRNA or in HLA‐B7 and chorionic gonadotropin‐α membrane‐bound polysomal mRNAs. These results support the possibility that there are multiple mechanisms for the attachment of specific classes of mRNAs to the cytoskeleton.
Characterization of anti‐sticking factor‐II from goat epididymal plasma
Authors: Roy Nabina , Majumder Gopal C. 
Published: May 2005

AbstractA previous study has characterized the major 47 kDa anti‐sticking factor (ASF‐I) from goat cauda‐epididymal plasma (Roy, N., and Majumder, G. C., Biochim. Biophys. Acta, 991: 114–122, 1989). This study reports the purification and characterization of ASF‐II, another anti‐sticking factor from the goat epididymal plasma. ASF‐II was purified to apparent homogeneity by using concanavalin A–agarose affinity chromatography, DEAE‐cellulose chromatography, alumina gel adsorption, and isoelectric focussing techniques. It showed a single protein band by both non‐denaturing and SDS–polyacrylamide gel electrophoresis. ASF‐II showed a molecular weight of 36,000 and a sedimentation constant of 2.4S. ASF‐II is largely stable to heat treatment and it is a specific glycoprotein having high affinity and specificity for its anti‐sticking action. At saturating concentration (1 nM) it inhibited adhesion of nearly 50% of spermatozoa to the glass surface of the haemocytometer counting chamber. Both the protein and sugar parts of the factor are essential for the anti‐sticking activity since it lost its activity completely when treated with trypsin, L‐fucosidase, or mannosidase. ASF‐II does not coat the glass surface and it binds to spermatozoa. Data are consistent with the view that ASF‐II has not been derived from the larger ASF‐I molecule due to its enzymic modifications. Both ASF‐I and ‐II had no effect on sperm forward motility as evidenced by spectrophotometric motility assays, indicating thereby the suitability of the factors to improve the existing sperm motility assays by eliminating the possibility of cell‐sticking artifacts.