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Biomedical subjects

S Braun

Publications and source records attributed to S Braun.

At least 199 records · Page 11Linked to original sources
PubMed1995

A dual sensitivity screen system for TMJ image enhancement in cephalometric radiography: sensitometric evaluation.

OBJECTIVES: An in vitro evaluation of the image quality of the TMJ OrthoCeph Slimline Cassette System (TOSCS). METHODS: The density response, resolution and clarity of the system were evaluated by use of the characteristic curve, modulation transfer function and root mean square quantum mottle. Relative sharpness was evaluated qualitatively by five observers. RESULTS: Increased density with Trimax 12 gave almost the same contrast as that with Trimax 8 in the diagnostic range, whereas MTF and RMS for Trimax 12 were inferior. CONCLUSIONS: The dual-sensitivity screen system should lead to improved radiographic contrast of the TMJ region in cephalometric radiography. The reduction in sharpness is probably clinically insignificant.

Absorptiometry, Photon↗
PubMed1995

[Papillary muscle rupture in myocardial infarction].

We report nine patients with acute mitral regurgitation secondary to post-infarction papillary rupture operated between 1980 and 1992. Seven cases had posterior papillary muscle rupture. All patients were in critical conditions with pulmonary edema at the moment of surgery. In eight cases, mitral valve replacement was performed (4 with mechanical prostheses) and in one, the valve was repaired with papillary muscle reimplantation. Six cases were also subjected to myocardial revascularization with sapheneous vein grafts. Two patients (22%) died during the postoperative period and 4 had postoperative complications. The seven survivors have been followed during 6 to 115 month. Of theses, one died six month after surgery due to congestive heart failure, three are in functional class I and the rest in functional class II. It is concluded that, although mitral valve replacement for papillary muscle rupture has a high operative mortality and morbidity, long term results are satisfactory.

Aged↗
PubMed1995

[In vitro comparative activity (E test) of sparfloxacin and other 8 antimicrobial agents against bacteria isolated from patients with respiratory infections acquired in the community].

Sparfloxacin is a new antimicrobial that, while maintaining a good activity against gram negative bacilli, has a better in vitro activity against gram positive bacteria such as S pneumoniae, intracellular pathogens and anaerobic bacteria. The aim of this work was to study the in vitro activity of sparfloxacin against bacteria isolated from patients with community acquired respiratory infections between October 1994 and January 1995. Using the E-test technique, we studied the susceptibility to sparfloxacin, ciprofloxacin, ampicillin, amoxicillin/clavulanic acid, cefuroxime, cefotaxime, erythromycin, methicillin and nalidixic acid of 50 strains of S pneumoniae, 50 strains of H. influenzae, 50 strains of S aureus and 50 strains of S pyogenes. Sparfloxacin was active against 100% of S pneumoniae, H influenzae and S pyogenes strains. Twenty two percent of S aureus strains were resistant and the MIC 90 was 12 micrograms/ml. Sparfloxacin showed the best in vitro activity against H influenzae and S aureus, a similar activity with ampicillin and cefotaxime against S pneumoniae and a similar activity with ampicillin but superior to all other studied antimicrobial against S pyogenes. It is concluded that sparfloxacin is a good antimicrobial for bacteria isolated from patients with respiratory infections.

Anti-Bacterial Agents↗
PubMed1994

Altered chemotaxis of a Bacillus sphaericus L-ethionine-resistant sporulation mutant. A probable link between chemotaxis and sporulation.

A UV irradiation-induced mutant of B. sphaericus 2362 whose sporulation was inhibited neither by natural amino acids nor by L-ethionine was selected. The mutant (A61) grew slowly in rich amino acid medium and contained increased concentrations of heat-resistant spores throughout the growth. Slow growth of A61 was related to continuous presence of aging and sporulating cells even when the medium was rich in nutrients. The ability of the mutant to sense nutrient presence in the environment and to relate this information to systems regulating the switch from vegetative growth to sporulation seem to be damaged. A61 also demonstrated impaired chemotaxis. In contrast to the parent strain, only few amino acids elicited chemotactic response in A61. Methylation of the A61 methyl-accepting chemotaxis protein(s) was lower than that of the parent strain by one order of magnitude. Spontaneous fast-growing phenotypic revertants of A61 displayed sporulation behavior characteristic of B. sphaericus 2362. Their chemotaxis to amino acids was considerably improved. To some amino acids, it proved to be even stronger than in the original strain, B. sphaericus 2362. It is suggested, that methyl transfer events originating in the chemotactic system are involved in the triggering of sporulation, the A61 mutation being located in this signalling pathway.

Amino Acids↗
PubMed1994

Chemotaxis, sporulation, and larvicide production in Bacillus sphaericus 2362. The influence of L-ethionine, and of aminophenylboronic acid.

4-Aminophenylboronic acid (APBA), a known inhibitor of sporulation in Bacilli, as well as L-ethionine, a known inhibitor of chemotaxis in Enterobacteria, inhibited both sporulation and chemotactic behavior but not growth of Bacillus sphaericus. Both compounds also inhibited the methyl group turnover on the methyl-accepting chemotaxis protein (P53) in this microorganism. Sporulation of B. sphaericus was inhibited only when APBA was added to the growing culture before the late logarithmic stage. It was previously demonstrated that the ability of B. sphaericus to respond to chemoattractants sharply declines at the same age of the culture. Thus, it seems plausible that the action of both inhibitors upon sporulation may be attributed to the inhibition of some regulatory pathway common to chemotaxis and sporulation and involving protein methylation. Possible exchange of the nutrient depletion-related sensory information between chemotaxis and sporulation systems at the level of methyl group transfer is discussed.

Bacillus↗
PubMed1994

Motility and chemotaxis in Bacillus sphaericus. Dependence upon stage of growth.

Chemotaxis and motility of B. sphaericus 2362 were monitored as the function of a batch culture age. It was found that both functions changed independently during growth of the culture. Motility was low until the late logarithmic stage ensued, whereafter it increased sharply. The ability of cells to respond to chemoeffectors peaked at the mid-logarithmic phase. A major methyl-accepting chemotaxis protein (P53, M(r) = 53 kDa) was identified. The extent of label incorporation in this protein from L-[methyl-3H]methionine was maximal in mid- and late logarithmic phases of the growth. Cells in stationary cultures incorporated very low amounts of the label. At any stage, the labeling was maximal in starved cells; it was almost abolished in cells pre-incubated with amino acids. Although extents of P53 labeling in mid- and late logarithmic cells were similar, late logarithmic cells demonstrated a considerably impaired chemotaxis. Supermotile sporulating cells were practically insensitive to environmental stimuli. The difference in development of sensory and locomotive functions may be interpreted as an adaptive response. A well developed sensory apparatus would allow vegetative cells to adapt efficiently to fluctuating attractant gradients. Insensitive sporulating cells would tend to disperse randomly from the nutrient-exhausted area. Thus, spore formation would occur in larger volume of the habitat, increasing the chance of the microbial population to survive.

Alanine↗
PubMed1994

Motility and chemotaxis in Bacillus sphaericus. Dependence upon stage of growth.

Chemotaxis and motility of Bacillus sphaericus 2362 were monitored as a function of the batch culture age. It was found that both functions changed independently during growth of the culture. Motility was low until the late logarithmic stage ensued, whereafter it increased sharply. The ability of cells to respond to chemo-effectors peaked at the mid-logarithmic phase. A major methyl-accepting chemotaxis protein (P53, M(r) = 53 kDa) was identified. The extent of label incorporation in this protein from L-[methyl-3H]methionine was maximal in mid- and late-logarithmic phases of the growth. Cells in stationary cultures incorporated very low amounts of the label. At any stage, the labeling was maximal in starved cells; it was almost abolished in cells pre-incubated with amino acids. Although extents of P53 labeling in mid- and late logarithmic cells were similar, late logarithmic cells demonstrated a considerably impaired chemotaxis. Supermotile sporulating cells were practically insensitive to environmental stimuli. The difference in development of sensory and locomotive functions may be interpreted as an adaptive response. A well developed sensory apparatus would allow vegetative cells to adapt efficiently to fluctuating attractant gradients. Insensitive sporulating cells would tend to disperse randomly from the nutrient-exhausted area. Thus, spore formation would occur in larger volume of the habitat, increasing the chance of microbial population to survive.

Alanine↗
PubMed1994

Chemotaxis, sporulation, and larvicide production in Bacillus sphaericus 2362. The influence of L-ethionine, and of aminophenylboronic acid.

4-Aminophenylboronic acid (APBA), a known inhibitor of sporulation in Bacilli, as well as L-ethionine, a known inhibitor of chemotaxis in Enterobacteria, inhibited both sporulation and chemotactic behavior but not growth of Bacillus sphaericus. Both compounds also inhibited the methyl group turnover on the methyl-accepting chemotaxis protein (P53) in this microorganism. Sporulation of B. sphaericus was inhibited only when APBA was added to the growing culture before the late logarithmic stage. It was previously demonstrated that the ability of B. sphaericus to respond to chemoattractants sharply declines at the same age of the culture. Thus, it seems plausible that the action of both inhibitors upon sporulation may be attributed to the inhibition of some regulatory pathway common to chemotaxis and sporulation and involving protein methylation. Possible exchange of the nutrient depletion-related sensory information between chemotaxis and sporulation systems at the level of methyl group transfer is discussed.

Bacillus↗
PubMed1994

Altered chemotaxis of Bacillus sphaericus L-ethionine-resistant sporulation mutant. A probable link between chemotaxis and sporulation.

A UV irradiation-induced mutant of Bacillus sphaericus 2362 whose sporulation was inhibited neither by natural amino acids nor by L-ethionine was selected. The mutant (A61) grew slowly in rich amino acid medium and contained increased concentrations of heat-resistant spores throughout the growth. Slow growth of A61 was related to continuous presence of aging and sporulating cells even when the medium was rich in nutrients. Ability of the mutant to sense nutrient presence in the environment and to relate this information to systems regulating the switch from vegetative growth to sporulation seem to be damaged. A61 also demonstrated impaired chemotaxis. In contrast to the parent strain, only few amino acids elicited chemotactic response in A61. Methylation of the A61 methyl-accepting chemotaxis protein(s) was lower than that of the parent strain by one order of magnitude. Spontaneous fast-growing phenotypic revertants of A61 displayed sporulation behavior characteristic of B. sphaericus 2362. Their chemotaxis to amino acids was considerably improved. To some amino acids, it proved to be even stronger than in the original strain, B. sphaericus 2362. It is suggested, that methyl transfer events originating in the chemotactic system are involved in the triggering of sporulation, the A61 mutation being located in this signalling pathway.

Amino Acids↗
PubMed1994

Crystallization and preliminary crystallographic analysis of sfericase. A Bacillus sphaericus calcium-dependent serine proteinase.

Sfericase is an important intracellular proteinase produced by Bacillus sphaericus in the stationary phase of growth. It is a Ca(2+)-dependent serine proteinase with optimal activity at pH 9.0 to 9.3. The molecular mass of sfericase is 32 kDa, as determined by sedimentation equilibrium. It seems to be involved in the interplay of various elements of the mosquitocidal activity of B. sphaericus, and hence is important for biological mosquito control. Sfericase significantly reduces viscosity of human pathological bronchial secretions and has recently shown good clinical effects in treatment of bronchitis, pneumonia and sinusitis. This enzyme was isolated from B. sphaericus and single crystals were obtained by the hanging drop vapor diffusion method. The crystals belong to the monoclinic space group P2, with cell dimensions of a = 46.94 A, b = 64.55 A, c = 86.23 A and beta = 95.4 degrees. These crystals are mechanically strong, they are stable in the X-ray beam and they diffract to better than 1.8 A resolution. The cell dimensions are consistent with four molecules per unit cell and two molecules in the asymmetric unit. A complete native data set to 1.77 A resolution has been collected on a Rigaku R-AXIS-IIc Imaging Plate Detector system and a heavy-atom derivative search is presently in progress.

Amino Acid Sequence↗
PubMed1994

Daudi supernatant, unlike other H-Y antigen sources, exerts a sex-reversing effect on embryonic chick gonad differentiation.

In vitro cultures of intact chick gonads (organ cultures) and reaggregation cultures of dispersed gonad cells (roller cultures) were made. Gonads or gonad cells from 7-day-old chick embryos, at the stage when sex-specific differentiation begins, were cultured in the presence of presumed H-Y antigen-containing supernatants, or co-cultured in the presence of H-Y antigen-producing cell lines. The H-Y antigen-producing cells tested were of human, mouse, bovine and chicken origin. During organ culture, addition of supernatant of the human lymphoma cell line Daudi, or co-culture with Daudi cells, stimulated a clear proliferation of the germinal epithelium in male gonads, indicating feminization. A similar effect was obtained by treatment with estradiol. In reaggregation culture, the increase in nuclear size of germ cells was chosen as a parameter for feminization. A significant increase of germ cell nuclear size was observed in gonads cultured in the presence of Daudi supernatant. In both organ cultures and reaggregation cultures, other tested H-Y antigen sources and semi-purified H-Y antigen fractions did not exert significant effects on differentiation of the gonads or on the average area of the germ cell nuclei. These findings suggest that it is not H-Y antigen, but another protein produced by Daudi cells, that might be responsible for the sex-reversing effects.

Animals↗
PubMed1994

The response of spruce shoot aphid Cinara pilicornis hartig to ambient and filtered air at two elevations and pollution climates.

The effects of ambient air compared to filtered air on the reproduction of females and mean relative growth rate (MRGR) of nymphs of C. pilicornis on Norway spruce was determined in open-top chambers at Wengernalp in the Swiss Alps (1900 m a.s.l.) and at Schönenbuch near the city of Basle (400 m a.s.l.). The ambient concentration of O(3), the main pollutant at both sites, varied between 45 and 120 microg m(-3) (24-h mean) at both sites. A 5-8 day exposure of spruce saplings to ambient compared to filtered air enhanced the MRGR of nymphs of C. pilicornis of local and northern origins at Schönenbuch. The cumulative numbers of offspring of C. pilicornis were higher in ambient air chambers than in filtered air chambers at Schönenbuch, but not at Wengernalp. Filtration of ambient air did not affect significantly the levels of total free amino acids or reducing sugars in phloem sap or concentration of total phenolics in needles at the end of the growing season. The results suggest that ambient air with elevated O(3) and with high daily fluctuations, as it can be observed in Schönenbuch, affects aphid performance on conifers more than ambient air with also elevated, but rather constant levels of O(3), as it can be observed in mountain forest areas.

Journal Article↗
PubMed1994

Renal oncocytoma with a translocation t(9;11)(p23;q13).

We report a case of renal oncocytoma and confirm a tumor type specific translocation between chromosomes 9 and 11, that is t(9;11)(p23;q13q23). Each of the 45 cytogenetically analyzed metaphases of tumor cells showed a translocation of the long arm of chromosome 11 at q13 to chromosome 9 at 9p23 and to chromosome 20 at 20q13 that resulted in the following karyotype: 46,XX,der(11)ins(9;11)(p23;q13q23)ins(20;11)(q13;q23q25),del (22q13). Since genes encoding mitochondrial enzymes are clustered around the translocation site of chromosomes 11 and 20, they may have a role in the tumorigenesis of renal oncocytoma. In addition, if the development of oncocytomas shows different cytogenetic pathways the cytogenetic aberration of t(9;11)(p23;q12q13) can be of diagnostic help in differentiating a subset of oncocytoma from renal cell carcinoma.

Adenoma, Oxyphilic↗
PubMed1994

Cytogenetic findings in squamous cell carcinoma of the oral cavity.

A case of squamous cell carcinoma (SCC) of the oral cavity is presented which, in addition to normal metaphases, cytogenetically displayed two cell clones with chromosomal aberrations: 46,XY,1+del(5)(q13),der(18)t(5;18)(q13;p11),-5 and 49,XY,+5,+7,+10 After a review of the literature of the few cytogenetically analyzed cases, the findings confirm the multiclonal origin of oral SCC and also the commonly seen aberrations of chromosome 5.

Aged↗
PubMed1994

Vitamin E or probucol as donors for oxidation of human low-density lipoprotein by peroxidases/H2O2.

Horseradish peroxidase or myeloperoxidase and H2O2 oxidize human low-density lipoprotein (LDL) in the presence or absence of a xenobiotic donor without an essential lag phase as revealed by an increase in the absorption at 234 nm. In the latter case, natural antioxidants like vitamin E and congeners serve as donor; radical formation by the action of peroxidase has been described before. Otherwise trolox C or probucol have donor function in this system. After oxidation by peroxidase/H2O2 LDL showed the expected reduced antioxidant capacity against vitamin-E-consuming radicals.

Antioxidants↗
PubMed1994

Potential interaction of interleukin-4 with endogenous cytokines in vivo.

We employed alginate-entrapped cells secreting recombinant murine interleukin-4 (IL-4) to study the effect of IL-4 on hematopoietic cells of normal mice. The most dramatic effect was registered in an increase in the neutrophils and to a lesser extent the monocytes. A small increase in the CD4+, CD8+ and B220+ populations was also observed. Serum IgE levels also increased dramatically. All of these increases could be specifically inhibited with anti-IL-4. Antibodies to granulocyte-macrophage colony-stimulating factor, IL-3 and IL-5 could also inhibit some IL-4-mediated actions suggesting an interplay between these cytokines in vivo.

Alginates↗
PubMed1994

WeeFIM. Normative sample of an instrument for tracking functional independence in children.

A cross-sectional community sample of 417 children, ages 6 months to 8 years without developmental delays or in developmental programs, was seen. The Functional Independence Measure for Children (WeeFIM) was used to assess independence in self-care, sphincter control, transfers, locomotion, communication, and social cognition. Mean total WeeFIM was similar for males and females. There was a significant correlation between the age of the child in months and total WeeFIM scores for children ages 2 to 5 years (n = 222, r = .80, P < .01). There was a progressive increase of functional independence with increasing chronological age across all WeeFIM domains. We conclude that the WeeFIM is a useful instrument for measuring disability in children.

Adaptation, Psychological↗