Showing papers by "Ghent University published in 1992"
TL;DR: A number of natural or partially modified polymers were screened for muco-adhesive properties by routinely measuring the force of detachment for swollen polymer films from pig intestinal mucosa in a saline medium.
1,021 citations
TL;DR: A rapid screening of 77 aerotolerant Arcobacter strains revealed five major groups, which were identified by using DNA-DNA hybridization data as A. butzleri strains and strains belonging to one of the electrophoretic subgroups of A. cryaerophilus had similar fatty acid contents, and an analysis of fatty acid compositions allowed clear-cut differentiation of all of the other groups.
Abstract: The relationships of 77 aerotolerant Arcobacter strains that were originally identified as Campylobacter cryaerophila (now Arcobacter cryaerophilus [P. Vandamme, E. Falsen, R. Rossau, B. Hoste, P. Segers, R. Tytgat, and J. De Ley, Int. J. Syst. Bacteriol. 41:88-103, 1991]) and 6 reference strains belonging to the taxa Arcobacter nitrofigilis, Arcobacter cryaerophilus, and “Campylobacter butzleri” were studied by using a polyphasic approach, in which we performed DNA-rRNA hybridizations, DNA-DNA hybridizations, a numerical analysis of whole-cell protein patterns after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, an analysis of cellular fatty acid compositions, and a phenotypic analysis and determined DNA base ratios. Our results indicate that “C. butzleri” should be transferred to the genus Arcobacter as Arcobacter butzleri comb. nov., as was suggested by Kiehlbauch and coworkers (J. A. Kiehlbauch, D. J. Brenner, M. A. Nicholson, C. N. Baker, C. M. Patton, A. G. Steigerwalt, and I. K. Wachsmuth, J. Clin. Microbiol. 29:376-385, 1991). A rapid screening of all strains in which we used the sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique revealed five major groups, which were identified by using DNA-DNA hybridization data as A. cryaerophilus (two distinct electrophoretic subgroups), A. butzleri, A. nitrofigilis, and a new species, for which we propose the name Arcobacter skirrowii. The phylogenetic position within rRNA superfamily VI was established for each species. A. butzleri strains and strains belonging to one of the electrophoretic subgroups of A. cryaerophilus had similar fatty acid contents. An analysis of fatty acid compositions allowed clear-cut differentiation of all of the other groups. All of the species could be distinguished by using classical phenotypic tests, although erroneous identifications due to a shortage of clear-cut differentiating tests could occur.
391 citations
TL;DR: Male fertility was restored to genetically engineered male sterile oilseed rape plants by the suppression of cytotoxic ribonuclease activity in the anther by the formation of cell-specific RNase/RNase inhibitor complexes.
Abstract: Male fertility was restored to genetically engineered male sterile oilseed rape plants. Male sterile plants that express a chimaeric ribonuclease gene in the anther tapetal cell layer were crossed with male fertile plants that were transformed with a chimaeric tapetal-cell-specific ribonuclease-inhibitor gene. F1 progeny expressing both genes are restored to male fertility by the suppression of cytotoxic ribonuclease activity in the anther by the formation of cell-specific RNase/RNase inhibitor complexes. Genetically engineered male sterility and fertility restorer genes should facilitate hybrid seed production in crop plants.
389 citations
TL;DR: McCarthy's 4P classification of the marketing mix instruments has received wide acceptance in past decades as discussed by the authors, however, increasing criticism has been voiced, among other reasons becau...
Abstract: McCarthy's 4P classification of the marketing mix instruments has received wide acceptance in past decades. In recent years, however, increasing criticism has been voiced, among other reasons becau...
340 citations
TL;DR: By generating haploid plants, it is found that this silencing phenomenon is not dependent on allelic interaction between T‐DNA copies present at the same locus of homologous chromosomes, but rather is correlated with the transgene dose in the plant genome.
Abstract: A chimeric construct containing the Nicotiana plumbaginifolia beta-1,3-glucanase gn1 gene was introduced into Nicotiana tabacum SR1 to produce high levels of the enzyme constitutively. We determined that the GN1 protein represents a basic beta-1,3-glucanase isoform which accumulates into the vacuoles of the transgenic plants. Analysis of the progeny of the transgenic plant with the highest levels of gn1 expression revealed an unexpected phenomenon of gene suppression. Plants hemizygous for the T-DNA locus contained high levels of gn1 mRNA and exhibited a 14-fold higher beta-1,3-glucanase activity than untransformed plants. However, the expression of gn1 was completely suppressed in the homozygous plants: no corresponding mRNA or protein could be detected. This suppression mechanism occurs at a post-transcriptional level and is under developmental control. In addition, by generating haploid plants we found that this silencing phenomenon is not dependent on allelic interaction between T-DNA copies present at the same locus of homologous chromosomes, but rather is correlated with the transgene dose in the plant genome. We postulate that high doses of GN1 protein relative to the level(s) of other still unknown plant products could trigger the cellular processes directed to suppress gn1 expression.
315 citations
TL;DR: The observations of a more pronounced bone mineral deficit at the forearm than at the lumbar spine and the findings of osteopenia in both the patients with isolated GH deficiency and multiple pituitary deficiencies support the view that GH deficiency per se is responsible for part of the observed deficit.
Abstract: In order to determine whether growth hormone (GH) deficiency of childhood onset affects the adult bone mineral status, we assessed bone mineral content (BMC) by photon absorptiometry in 30 full-grown GH-deficient men (8 with isolated GH deficiency and 22 with multiple pituitary deficiencies; 28 previously treated with GH) and in 30 male controls matched for age (within 4 yr) and height (within 10 cm). Forearm BMC was measured by single photon absorptiometry just proximally of the distal one third of the nondominant forearm (PBMC-2 in arbitrary units and PBMC/bone width (BW) after normalization for bone width) and at a more distal site, close to the carpal joint (DBMC-2 and DBMC/BW). Lumbar BMC was measured by dual photon absorptiometry and reported as total BMC for L2-L4 (LBMC in g) and after normalization for projected area (LBMD in g/cm2). The patients had a significantly lower BMC, both at the forearm (P less than 0.0001) and at the lumbar spine (P less than 0.005): 35.7 +/- 1.0 vs. 50.0 +/- 1.6 and 36.9 +/- 1.2 vs. 52.8 +/- 1.9 (mean +/- SEM) for PBMC-2 and DBMC-2 in patients and controls, respectively; 1.36 +/- 0.03 vs. 1.70 +/- 0.04 and 1.07 +/- 0.03 vs. 1.35 +/- 0.04 for PBMC/BW and DBMC/BW; 34.00 +/- 1.08 vs. 42.02 +/- 1.27 g for LBMC and 0.886 +/- 0.016 vs. 0.976 +/- 0.018 g/cm2 for LBMD. Both the patients with isolated GH deficiency and the patients with multiple pituitary deficiencies were osteopenic when compared to their respective controls (P less than 0.01 to P less than 0.0001 for the patients with multiple deficiencies; statistical significance reached for PBMC-2, DBMC-2, and DBMC/BW only, P less than 0.05, in the small group of patients with isolated GH deficiency). For the patients (n = 19) who had at least three serial measurements over a period of 6 to 28 months, no decrease in BMC was detected. Our findings indicate that men with GH deficiency of childhood onset present with a low adult bone mass, despite prior GH substitution in most of these subjects. The observations of a more pronounced bone mineral deficit at the forearm (20-30% lower mean values, depending on the type of measurements) than at the lumbar spine (9-19%) and the findings of osteopenia in both the patients with isolated GH deficiency and multiple pituitary deficiencies, support the view that GH deficiency per se is responsible for part of the observed deficit.(ABSTRACT TRUNCATED AT 400 WORDS)
312 citations
TL;DR: The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.
Abstract: Ribosomal rRNA gene fragments (rDNA) encompassing the 16S rDNA, the 16S-23S rDNA spacer region and part of the 23S rDNA of 95 strains belonging to 13 well-described taxa of the eubacterial family Comamonadaceae (beta subclass of the Proteobacteria or rRNA superfamily III) were enzymatically amplified using conserved primers. The fragments of approximately 2400 base pairs were subjected to restriction analysis. Restriction fragment length patterns obtained with HinfI enabled us to distinguish 9 of the 13 taxa studied. Restriction with CfoI was necessary to differentiate Acidovorax delafieldii from A. temperans and Hydrogenophaga flava from H. pseudoflava. The results indicate that amplified rDNA restriction analysis is a simple and reliable tool for the identification of bacterial species.
266 citations
TL;DR: In this article, a different interpretation of the power decomposition proposed by H. Akagi et al. for distorted three-phase situations is given, which makes it possible to generalize the technique to single-phase systems and polyphase systems, also to include rigorously zero sequence currents and voltages.
Abstract: A different interpretation of the power decomposition proposed by H. Akagi et al. (1984) for distorted three-phase situations is given. This makes it possible to generalize the technique to single-phase systems and polyphase systems and also to include rigorously zero sequence currents and voltages. >
265 citations
TL;DR: A comprehensive review of the state of the art in bio-flavour synthesis can be found in this paper, with emphasis on currently commercialised processes and regulatory aspects of biotechnological production of aroma compounds.
252 citations
TL;DR: It is provided strong arguments that the inducer flavonoid, involved in transcriptional activation of Azorhizobium nod genes, interacts directly with the NodD protein, thereby increasing its binding affinities for theNodD box.
Abstract: Nodulation of leguminous plants by Rhizobium, Bradyrhizobium, and Azorhizobium spp. is dependent on the induction by the plant host of different bacterial nodulation (nod) loci. The transcription of these nod loci is activated in the presence of plant-produced flavonoids upon binding of the NodD protein--a LysR-type activator--to specific sequences present in the nod promoters. Originally, a 47-base-pair (bp) region called the nod box was shown to be the target sequence for binding of NodD. From the comparison of the nod box sequences of (brady)rhizobia with a more divergent nod box from Azorhizobium caulinodans, we now propose a modular build-up of the nod box with the sequence A-T-C-N9-G-A-T as the binding target of the NodD protein (the NodD box). More generally, we show that LysR-type-regulated promoters contain the characteristic sequence T-N11-A as the core of an inverted repeat and propose this to be the "LysR motif" involved in specific binding to LysR-type proteins. Data obtained upon site-specific mutagenesis of this motif in the NodD box sustains this proposal. Further, we provide strong arguments that the inducer flavonoid, involved in transcriptional activation of Azorhizobium nod genes, interacts directly with the NodD protein, thereby increasing its binding affinities for the NodD box.
248 citations
TL;DR: These studies, the first genetic analysis of the interaction of a Gram‐positive bacterium with plants, suggest that a novel mechanism for plant tumour induction has evolved in R.fascians independently from the other branches of the eubacteria.
Abstract: Rhodococcus fascians is a nocardiform bacteria that induces leafy galls (fasciation) on dicotyledonous and several monocotyledonous plants The wild-type strain D188 contained a conjugative, 200 kb linear extrachromosomal element, pFiD188 Linear plasmid-cured strains were avirulent and reintroduction of this linear element restored virulence Pulsed field electrophoresis indicated that the chromosome might also be a linear molecule of 4 megabases Three loci involved in phytopathogenicity have been identified by insertion mutagenesis of this Fi plasmid Inactivation of the fas locus resulted in avirulent strains, whereas insertions in the two other loci affected the degree of virulence, yielding attenuated (att) and hypervirulent (hyp) bacteria One of the genes within the fas locus encoded an isopentenyltranferase (IPT) with low homology to analogous proteins from Gram-negative phytopathogenic bacteria IPT activity was detected after expression of this protein in Escherichia coli cells In Rfascians, ipt expression could only be detected in bacteria induced with extracts from fasciated tissue Rfascians strains without the linear plasmid but containing this fas locus alone could not provoke any phenotype on plants, indicating additional genes from the linear plasmid were also essential for virulence These studies, the first genetic analysis of the interaction of a Gram-positive bacterium with plants, suggest that a novel mechanism for plant tumour induction has evolved in Rfascians independently from the other branches of the eubacteria
TL;DR: The structure of a complex CelD with a substrate analogue suggests a mechanism for substrate hydrolysis, and the three-dimensional structure of the catalytic core of cellobiohydrolase CBHII from the fungus Trichoderma reesei is shown.
Abstract: CELLULOSIC biomass is recycled by a variety of microorganisms occupying different habitats1. Studies of their cellulase systems have included the purification of enzyme components, the determination of their enzymological properties2 and the cloning and characterization of their structural genes3. Sequence analysis of more than 70 cellulases permits grouping into seven families corresponding to distinct structural types4,5. The three-dimensional structure of the catalytic core of cellobiohydrolase CBHII from the fungus Trichoderma reesei has been reported6. Here we show that endoglucanase CelD from Clostridium thermocellum, which is representative of a different family of cellulose-degrading enzymes consisting of at least 11 bacterial, fungal and plant endoglucanases5,7, has a globular structure, with an amino-terminal immunoglobulin-like domain tightly packed against a larger catalytic domain. The latter shows a novel protein fold, shaped like an α-barrel of 12 helices connected by loops that form the active site. The structure of a complex CelD with a substrate analogue suggests a mechanism for substrate hydrolysis.
TL;DR: Careful study of the matrix effect in ICP-MS showed that the magnitude of the signal suppression or enhancement depends in a regular way on the mass number, and it was shown that using an internal standard with mass number close to that of the analyte improves the precision.
TL;DR: Degradation of poly(3-hydroxybutyrate) and copolymers with 3-Hydroxyvaleric acid was investigated in natural environments, and the microorganisms involved were isolated and identified.
Abstract: Degradation of poly(3-hydroxybutyrate) and copolymers with 3-hydroxyvaleric acid was investigated in natural environments, and the microorganisms involved were isolated and identified. The influence of abiotic and biotic factors on the degradation is discussed.
TL;DR: Cyc1At is encoded by a single gene, but the amplification by the polymerase chain reaction of other fragments homologous to cyclins indicates the presence of a family of cyclins in Arabidopsis.
Abstract: A key element of cell cycle control in eukaryotes is the M-phase kinase, composed of p34cdc2 and cyclin. To dissect the plant cell cycle, we have previously isolated a cdc2 gene homolog from Arabidopsis thaliana. We have now cloned an Arabidopsis cDNA corresponding to cyclins. This gene (cyc1At) encodes a protein with a predicted molecular mass of 48.4 kDa and a domain homologous to the cyclin box of mitotic cyclins. However, by sequence comparison the cyc1At gene could not be assigned to the A- or B-type group. The mRNA accumulates preferentially in actively dividing cells and when these cells are blocked during the cell cycle, the amount of transcripts decreases dramatically. cyc1At mRNA is found mainly in G2-phase nuclei, suggesting that its expression is periodic in the cell cycle. Microinjection of synthetic cyc1At mRNA induced meiotic maturation in Xenopus oocytes. Cyc1At is encoded by a single gene, but the amplification by the polymerase chain reaction of other fragments homologous to cyclins indicates the presence of a family of cyclins in Arabidopsis.
TL;DR: A practical method is developed for selecting the minimal number of lumped elements needed to represent a lossy transmission line if a certain accuracy is desired in a well-defined frequency range.
Abstract: A practical method is developed for selecting the minimal number of lumped elements needed to represent a lossy transmission line if a certain accuracy is desired in a well-defined frequency range. This method, which uses dimensionless transmission line parameters, can be used in a wide range of applications and is also extended to hybrid equivalent circuits, consisting of ideal single lossless lines and resistors. For completeness, a lumped element model for coupled lossy lines is presented which uses the same dimensionless parameters and the same criteria as proposed for single lines. An example of coupled transmission line structure including skin-effect losses illustrates the approach. >
TL;DR: A large fenestration into the lateral ventricles and into the basal cisterns is proposed as the treatment of choice for large suprasellar arachnoid cysts in children.
Abstract: Four cases of large suprasellar arachnoid cysts in children are described. The authors propose a large fenestration into the lateral ventricles and into the basal cisterns as the treatment of choice. A specific multipurpose cerebral endoscope has been designed by the first author. The endoscopic technique with different instruments and with the use of a laser is illustrated. Results and complications are discussed.
TL;DR: A plasmid vector, pGV910, and a derived cosmid, pRG930, have been constructed that contain the ColE1 and pVS1 origins of replication and are stably maintained in Escherichia coli, Agrobacterium tumefaciens, and Azorhizobium caulinodans ORS571.
Abstract: A plasmid vector, pGV910, and a derived cosmid, pRG930, have been constructed. Both contain the ColE1 and pVS1 origins of replication and are stably maintained in Escherichia coli, Agrobacterium tumefaciens, and Azorhizobium caulinodans ORS571. They are compatible with commonly used IncP cloning vectors, although pVS1 was classified as an IncP plasmid, unable to replicate in E. coli (Y. Itoh, J.M. Watson, D. Haas, and T. Leisinger, Plasmid 11:206-220, 1984). Promoter selection vectors were derived from both of these plasmids by using a promoterless beta-glucuronidase and/or beta-galactosidase gene. These vectors facilitate the study of gene expression in bacteria under particular environmental conditions. This is illustrated by the expression of the gusA gene under the control of a nod promoter in A. caulinodans nodulating stem-located infection sites on Sesbania rostrata.
TL;DR: The design of a computationally efficient auditory model, the perceptually motivated determination of the model parameters, the conception of a reliable pitch extractor for speech analysis, and the elaboration of an experimental procedure for evaluating the performance of such a pitch Extractor are described.
Abstract: In this paper, an accurate pitch and voiced/unvoiced determination algorithm for speech analysis is described. The algorithm is called AMPEX (auditory model‐based pitch extractor) and it performs a temporal analysis of the outputs emerging from a new auditory model. However, in spite of its use of an auditory model, AMPEX should not be regarded as a substitute for any psychophysical theory of human auditory pitch perception. What is mainly described is the design of a computationally efficient auditory model, the perceptually motivated determination of the model parameters, the conception of a reliable pitch extractor for speech analysis, and the elaboration of an experimental procedure for evaluating the performance of such a pitch extractor. In the course of the evaluation experiment several kinds of speech stimuli including clean speech, bandpass‐filtered speech, and noisy speech were presented to three different pitch extractors. The experimental results clearly indicate that AMPEX outperforms the best algorithms available.
TL;DR: In this paper, a study of nonlinear dust-acoustic waves in a dusty plasma is made, which consists of any number of cold negatively charged dust grain species, in addition to the presence of the more usual isothermal hot and cold electrons and isothermal positive ions.
TL;DR: Preliminary characterization of the gene product showed that it is a cholylglycine hydrolase with only slight activity against taurine conjugates, and southern blot analysis indicated that the cloned gene has similarity with genomic DNA of bile acid hydrolases-active Lactobacillus spp.
Abstract: The conjugated bile acid hydrolase gene from the silage isolate Lactobacillus plantarum 80 was cloned and expressed in Escherichia coli MC1061. For the screening of this hydrolase gene within the gene bank, a direct plate assay developed by Dashkevicz and Feighner (M. P. Dashkevicz and S. D. Feighner, Appl. Environ. Microbiol. 53:331-336, 1989) was adapted to the growth requirements of E. coli. Because of hydrolysis and medium acidification, hydrolase-active colonies were surrounded with big halos of precipitated, free bile acids. This phenomenon was also obtained when the gene was cloned into a multicopy shuttle vector and subsequently reintroduced into the parental Lactobacillus strain. The cbh gene and surrounding regions were characterized by nucleotide sequence analysis. The deduced amino acid sequence was shown to have 52% similarity with a penicillin V amidase from Bacillus sphaericus. Preliminary characterization of the gene product showed that it is a cholylglycine hydrolase (EC 3.5.1.24) with only slight activity against taurine conjugates. The optimum pH was between 4.7 and 5.5. Optimum temperature ranged from 30 to 45 degrees C. Southern blot analysis indicated that the cloned gene has similarity with genomic DNA of bile acid hydrolase-active Lactobacillus spp. of intestinal origin.
TL;DR: Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent.
Abstract: Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent hirae was found almost as often as Ent faecalis Most Ent faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol Typical Ent avium as well as atypical Ent avium-like strains were seen in dogs, while the related species Ent raffinosus was associated with cat tonsils Enterococcus cecorum also occurred mainly in cats Certain atypical strains, presumptively identified as Ent cecorum, shared characteristics with Ent columbae The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep canis Streptococcus canis and Strep bovis predominated in anal swabs The canine Strep suis differed from the common porcine strains in fermenting mannitol Forty-seven of the 288 isolates examined could not be identified or related to known species The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described
TL;DR: The ecological effects of grassland afforestation have been investigated in a comparative study between different tree species on a sandy-loam substrate, and the results have practical consequences for the choice of tree species in new forest plantations.
Abstract: The ecological effects of grassland afforestation have been investigated in a comparative study between different tree species on a sandy-loam substrate. After 20 yr of forest, the earthworm communities and litter decomposition rates differed considerably, depending on the quality and quantity of the litter fractions produced. Under Quercus palustris , earthworm biomass diminished, and litter accumulation and soil acidification had begun. The results have practical consequences for the choice of tree species in new forest plantations.
TL;DR: In the long run, the master keratinocyte database is expected to link protein and DNA sequencing and mapping information and to provide an integrated picture of the expression levels and properties of the thousands of proteins that orchestrate various keratinocytes functions both in health and disease.
Abstract: The master two-dimensional gel database of human keratinocytes currently lists 2980 cellular proteins (2098 isoelectric focusing, IEF; and 882 nonequilibrium pH gradient electrophoresis, NEPHGE) many of which correspond to posttranslational modifications. About 20% of all recorded proteins have been identified (protein name, organelle components, etc.) and they are listed in alphabetical order together with their Mr, pI, cellular localization and credit to the investigator(s) that aided in the identification. Also, we have listed 145 microsequenced proteins that are recorded in this database. As an aid in localizing the polypeptides we have included blow-ups of the master images (IEF, NEPHGE) displaying all the protein numbers. In the long run, the master keratinocyte database is expected to link protein and DNA sequencing and mapping information (Human Genome Program) and to provide an integrated picture of the expression levels and properties of the thousands of proteins that orchestrate various keratinocyte functions both in health and disease.
TL;DR: Evidence for the existence of Ehlers–Danlos syndrome type VII C in humans is presented, characterized by skin fragility, altered polymers seen as hieroglyphic pictures with electron microscopy, accumulation of p–N–α1 and p– N–α2 collagen type I in the dermis and absence of processing of the p-N–I polypeptides in fibroblast cultures.
Abstract: Ehlers-Danlos (ED) syndrome type VII is characterized by the accumulation of collagen precursors in connective tissues. ED VII A and B are caused by mutations in the genes of alpha-1 and alpha-2 collagen I which result in the disruption of the cleavage site of procollagen I N-proteinase. The existence of ED VII C in humans has been hypothesized on the basis of a disorder in cattle and sheep related to the absence of the enzyme. We now present evidence for the existence of this disease in humans, characterized by skin fragility, altered polymers seen as hieroglyphic pictures with electron microscopy, accumulation of p-N-alpha-1 and p-N-alpha-2 collagen type I in the dermis and absence of processing of the p-N-I polypeptides in fibroblast cultures.
TL;DR: It is derived that the endothelium-dependent hyperpolarization contributes for at least 20-30% of the maximal relaxation effect of acetylcholine on rat aorta and may contribute to the depression of the endothelial-dependent relaxation in hypertension.
Abstract: Endothelium-dependent relaxations are depressed in hypertension. In this study we investigated the possible involvement of endothelium-dependent smooth muscle hyperpolarization in this phenomenon. In isolated aortic segments from control rats, acetylcholine (10(-8)-10(-5) M) elicits relaxations after precontraction with norepinephrine (10(-7) M), and acetylcholine or carbachol (10(-5) M) induce smooth muscle hyperpolarization (10.6 +/- 0.9 mV). Both effects disappear after removal of the endothelium and are depressed by tetraethylammonium (3 x 10(-3) M), a rather nonspecific blocker of K+ channels, but not by glibenclamide (10(-5) M), a potent blocker of the ATP-regulated K+ channels, which has a marked effect on the relaxation induced by BRL 38227. The relaxation effect of acetylcholine is impaired in norepinephrine-contracted preparations from hypertensive rats but is not further depressed by tetraethylammonium. In aorta from hypertensive rats, hyperpolarization induced by carbachol was significantly reduced to a mean of only 21.8% of the values obtained in preparations from normotensive rats. From the relaxation-hyperpolarization relation obtained with BRL 38227 (opening K+ channels), it is derived that the endothelium-dependent hyperpolarization (approximately 10 mV) contributes for at least 20-30% of the maximal relaxation effect of acetylcholine on rat aorta. It is concluded that the diminished endothelium-dependent hyperpolarization may contribute to the depression of the endothelium-dependent relaxation in hypertension.
TL;DR: Streptococcus bovis largely predominated in ruminating calves, young cattle and dairy cows, but a variety of other streptococci and enterococci were found in the faeces of young ruminating animals.
Abstract: Faeces from non-ruminating calves were found to contain several species of enterococci: Enterococcus avium, Ent. cecorum, Ent. durans, Ent. faecalis, Ent. faecium and Ent. hirae. Enterococcus faecalis was the most frequent. Few of these animals carried streptococci.
Streptococcus bovis largely predominated in ruminating calves, young cattle and dairy cows. Other streptococci as well as enterococci were infrequent in dairy cows, but a variety of other streptococci and enterococci were found in the faeces of young ruminating animals.
TL;DR: A total of 233 multibox corer samples from 36 stations along the southeastern Weddell Sea shelf and upper continental slope between Atka Bay and Gould Bay, covering a depth range from 170 to 2,037 m, provided biomass and abundance data for analysis of faunal communities.
Abstract: A total of 233 multibox corer samples from 36 stations along the southeastern Weddell Sea shelf and upper continental slope between Atka Bay (70°S) and Gould Bay (78° S), covering a depth range from 170 to 2,037 m, provided biomass and abundance data for analysis of faunal communities. Twenty-eight major taxa were distinguished. Based on these data, 3 different macrobenthos communities could be identified by means of cluster analysis. Hexactinellid sponges, polychaetes and echinoderms were most abundant. Biomass values have been found to be in the range of 94 mg up to 1.6 kg wet weight per sqm. According to TWINSPAN, the sampled stations can be divided into two groups each consisting of two major subgroups. Peracarid crustaceans, polychaetes and bivalves are commonly distributed in the area of investigation whereas others such as sponges, brachiopods, pantopods and asteroids are more confined to Kapp Norvegia and Halley Bay. Biomass values of these latter taxa off Kapp Norvegia were generally higher than in the Halley Bay area.