Assembly of human contact phase proteins and release of bradykinin at the surface of curli-expressing Escherichia coli.

1996

Previous work has demonstrated that most strains of the human pathogen Streptococcus pyogenes bind kininogens through M protein, a fibrous surface protein and virulence determinant. Here we find that strains of several other pathogenic bacterial species, both Gram-positive and Gram-negative, isolated from patients with sepsis, also bind kininogens, especially kininogen (HK). The most pronounced interaction was seen between HK and Escherichia coli. Among clinical isolates of E. coli, the majority of the enterohaemorrhagic, enterotoxigenic, and sepsis strains, but none of the enteroinvasive and enteropathogenic strains, bound HK. Binding of HK to E. coli correlated with the expression of curl…

Prospective randomised trial of two dose levels of megestrol acetate in the management of anorexia-cachexia syndrome in patients with metastatic canc…

1996

Two doses of megestrol acetate (MA) have been prospectively compared in a random fashion as treatment for cancer-related anorexia-cachexia syndrome (ACS) in 122 patients with progressive soft tissue sarcoma, colorectal, lung, head and neck and renal cancer resistant to systemic chemotherapy. After 30 days of MA, 55% of patients receiving MA at 160 mg day-1 reported an increase in appetite, 27% of patients no variation and 18% complained of a decrease in appetite. Patients treated with MA at 320 mg day-1 reported an increase in appetite in 68% of cases, a stabilisation in 20% of cases and a decrease in 12%. Although an increase in appetite was more frequently observed in patients receiving M…

Vortex mutual friction in rotating superfluid 3He

1996

The Manchester rotating cryostat has been used to measure the longitudinal and transverse coefficients of vortex mutual friction in the A and B phases of superfluid 3He. In the B phase the dominant contribution to the mutual friction is scattering of excitations off occupied bound states in the vortex core. The A phase results are explained quantitatively by assuming that doubly quantised continuous vortices are created with a dynamics determined by the equation of motion of the orbital vector I; the measurements enable us to put an upper limit on the orbital inertia of less than 0.01h{stroke} per Cooper pair. History-dependent textural effects which had to be overcome in order to make mean…

Stereoselective Synthesis of 8,12-Furanoeudesmanes from Santonin. Absolute Stereochemistry of Natural Furanoeudesma-1,3-diene and Tubipofurane.

1996

Ketobutenolide 3, easily obtained from santonin (1), has been transformed into two natural furanoeudesmanes 4 and 5, isolated from Commiphora molmol and Tubipora musica, respectively. trans- And cis-decalin systems were obtained by stereoselective reduction of the C(4)-C(5) double bond in 3 in the following way: hydrogenation of 3 over Pd/C followed by acidic treatment gave the cis isomer 10 as the major product; selective hydrogenation of the C(1)-C(2) double bond with the Wilkinson's catalyst followed by reduction with NaTeH yielded mainly the trans isomer 9. Compounds 9 and 10 were transformed into 4 and 5 in parallel sequences. Optical rotation and CD measurements of the synthetic produ…

Grafted Rods: A Tilting Phase Transition

1996

A tilting phase transition is predicted for systems comprising rod like molecules which are irreversibly grafted to a flat surface, so that the non interacting rods are perpendicularly oriented. The transition is controlled by the grafting density $\rho$. It occurs as $\rho$ increases as a result of the interplay between two energies. Tilt is favoured by the van-der-Waals attraction between the rods. It is opposed by the bending elasticity of the grafting functionality. The role of temperature is discussed, and the tilting mechanism is compared to other tilting transitions reported in the literature.

Probing hadron structure by real and virtual photons

1996

The importance of subnuclear degrees of freedom in photon absorption and electron scattering by nuclei is discussed. After a short introduction into the basic properties of one-photon processes and a very brief survey on the nuclear response in the various regions of energy and momentum transfers, the particular role of subnuclear degrees of freedom in terms of meson and isobar degrees of freedom is considered. Their importance is illustrated by several reactions on the deuteron which are currently under study at c.w.\ electron machines like MAMI in Mainz.

Efecto del tratamiento con pentoxifilina en la isquemia-reperfusión intestinal.

1996

Se realizó un estudio experimental con ratas macho cepa Wistar, para valorar el efecto de la Pentoxifilina (PTX) en la lesión por Isquemia-Repefusión intestinal y de esta forma considerar la conveniencia o no de su utilización, en el caso de trasplante de Intestino Delgado.Material y métodosSe distribuyeron aleatoriamente 150 ratas en 6 grupos: 2 controles, alos que se administró suero fisiológico, y 4 grupos con tratamiento Pentoxifilina: grupo Pl (1 mg/Kg de PTX 1 hora antes de isquemia), grupo P2 (1 mg/Kg de PTX en el momento de la reperfusión), grupo P3 (10 mg/ Kg de PTX 1 hora antes de la isquemia), grupo P4 (10 mg/Kg de PT'X en momento de la reperfusión).La isquemia intestinal se real…

Resummation of anisotropic quartic oscillator. Crossover from anisotropic to isotropic large-order behavior

1996

We present an approximative calculation of the ground-state energy for the anisotropic anharmonic oscillator Using an instanton solution of the isotropic action $\delta = 0$, we obtain the imaginary part of the ground-state energy for small negative $g$ as a series expansion in the anisotropy parameter $\delta$. From this, the large-order behavior of the $g$-expansions accompanying each power of $\delta$ are obtained by means of a dispersion relation in $g$. These $g$-expansions are summed by a Borel transformation, yielding an approximation to the ground-state energy for the region near the isotropic limit. This approximation is found to be excellent in a rather wide region of $\delta$ aro…

Gauge-invariant resummation formalism for two-point correlation functions

1996

The consistent description of unstable particles, renormalons, or other Schwinger--Dyson-type of solutions within the framework of perturbative gauge field theories necessitates the definition and resummation of off-shell Green's functions, which must respect several crucial physical requirements. A formalism is presented for resummation of off-shell two-point correlation functions, which is mainly based on arguments of analyticity, unitarity, gauge invariance and renormalizability. The analytic results obtained with various methods, including the background field gauges and the pinch technique are confronted with the physical requirements imposed; to one-loop order the pinch technique appr…

Immunohistochemistry of primary central nervous system malignant rhabdoid tumors: report of five cases and review of the literature

1996

Malignant rhabdoid tumors (MRT) are characterized by a typical light microscopic morphology with uniformly round tumor cells, vacuolated cytoplasm with occasional round, hyaline intracytoplasmic, periodic acid-Schiff-positive inclusions, vesicular nuclei with prominent nucleoli and positive immunoreactivity for vimentin. The histogenesis of MRT is controversial. Five cases of primary central nervous system (CNS) rhabdoid tumors in children are presented. Immunohistochemical, light and electron microscopic features are compared with primary CNS malignant rhabdoid tumors reported in the literature. Expression of various neurofilaments in our cases of primary CNS rhabdoid tumors was prominent …

A Double Calix[4]arene in a 1,3-alternate Conformation

1996

Book Review: Resorcinol. Its Uses and Derivatives.(Series: Topics in Applied Chemistry.) By H. Dressler

1996

Multiple-unit responses to pitch changes in rabbits

1996

Multiple-unit activity (MUA) was recorded from the hippocampus (Hc), the visual cortex (VCx) and the cerebellar cortex (CerCx) in rabbits when pitch deviant tones were presented in a series of standard tones (oddball situation) and when standard tones were absent (deviant-alone situation). Significant MMN-like responses (deviant responses minus standard responses in the oddball situation) occurred in Hc, reflecting a MUA increase to the standards and its decrease to the deviants. In accordance with parallel ERPs reported earlier, the MMN-like responses reflected responses only to different presentation frequencies of stimuli. Non-selectivity in the pitch of such responses in VCx and a lack …

Inverse relationship of melanocyte differentiation antigen expression in melanoma tissues and CD8+ cytotoxic-T-cell responses: evidence for immunosel…

1996

Antigenic peptides derived from differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for MHC-restricted cytotoxic T lymphocytes (CTL). CTL directed against peptides derived from the Melan A/MART-1, tyrosinase and gp100/Pmel17 antigens can be detected in melanoma patients and in healthy controls. The presence of defined antigenic peptides and corresponding precursor CTL in patients with metastatic melanoma opens perspectives for the development of antigen-specific tumor vaccines. In this study, we examined the expression of Melan A/MART-1, tyrosinase and gp100lPmel17 in fresh melanoma tissues of HLA-A2+ patients and the spontaneous CTL rea…

Three-dimensional cell culture induces novel proliferative and metabolic alterations associated with oncogenic transformation

1996

To date, cell biological characteristics of oncogene-transfected cells have been investigated either in relatively homogeneous monolayer cultures or in heterogeneous tumors in vivo. To evaluate the emergence of cellular heterogeneity during tumor formation, we have established a multicellular spheroid system from an oncogene-dependent, genetically determined 2-stage carcinogenesis model for 3-dimensional growth under well-defined conditions. The effect of T24Ha-ras transfection on cellular growth, proliferation, cell viability and oxygenation was investigated using spontaneously immortalized (Rat1) and c-myc-transfected (M1) Fisher 344 rat embryo fibroblasts and a tumorigenic T24Ha-ras-tran…

Mapping and quantification of biomolecules in tumor biopsies using bioluminescence

1996

Quantitative bioluminescence and single-photon imaging have been applied for mapping concentration distributions of metabolites, such as adenosine triphosphate (ATP), glucose and lactate, in biopsies of cervical cancers in patients. Biopsies were taken before a conventional radiation treatment, and a number of clinically relevant data, such as local tumor control, patient survival, metastatic spread and so forth, were documented. There was no correlation between staging or grading and any of the metabolic parameters measured. Local correlations between ATP, glucose and lactate on a pixel-to-pixel basis were generally positive, with respective Spearman's correlation coefficients less in pati…

Concept of an extracellular regulation of muscular metabolic rate during heavy exercise in humans by psychophysiological feedback.

1996

Efferent motor signals to skeletal muscles concern not only the space/ time pattern of motion, but also the setting of muscular performance and through this the control of the current metabolic rate. For an optimal adjustment of metabolic rate during heavy exercise-e.g. in athletic competitions-a feedback control system must exist, including a programmer that takes into consideration a finishing point (teleoanticipation). The presented experiments, using Borg's scale, indicate the existence and functioning of a system for optimal adjustment of performance during heavy exercise and the relevance of teleoanticipatory effects. Thus motor learning includes not only somatosensory control, but al…

Control of adenine nucleotide metabolism and glycolysis in vertebrate skeletal muscle during exercise.

1996

The turnover of adenosine triphosphate (ATP) in vertebrate skeletal muscle can increase more than a hundredfold during high-intensity exercise, while the content of ATP in muscle may remain virtually unchanged. This requires that the rates of ATP hydrolysis and ATP synthesis are exactly balanced despite large fluctuations in reaction rates. ATP is regenerated initially at the expense of phosphocreatine (PCr) and then mainly through glycolysis from muscle glycogen. The increased ATP turnover in contracting muscle will cause an increase in the contents of adenosine diphosphate (ADP), adenosine monophosphate (AMP) and inorganic phosphate (P(i)), metabolites that are substrates and activators o…

Is there a critical tissue oxygen tension for bioenergetic status and cellular pH regulation in solid tumors?

1996

Bioenergetic and metabolic status have been correlated with tissue oxygenation in murine fibrosarcomas (FSaII) of varying sizes (44-600 mm3). Ratios of beta-nucleoside triphosphates to inorganic phosphate (beta NTP/P) and phosphocreatine to inorganic phosphate (PCr/P(i)) ratios derived from 31P nuclear magnetic resonance spectroscopy (NMR) were positively correlated to median tissue O2 tension (pO2) values using O2-sensitive needle electrodes. pH declined during growth with intracellular acidosis being evident in tumors350 mm3. Whereas lactic acid formation greatly contributed to this decline in small and medium-sized tumors, adenosine triphosphate (ATP) hydrolysis and slowing down of the a…

Flying insects: model systems in exercise physiology

1996

Insect flight is the most energy-demanding exercise known. It requires very effective coupling of adenosine triphosphate (ATP) hydrolysis and regeneration in the working flight muscles.31P nuclear magnetic resonance (NMR) spectroscopy of locust flight muscle in vivo has shown that flight causes only a small decrease in the content of ATP, whereas the free concentrations of inorganic phosphate (P i ), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were estimated to increase by about 3-, 5- and 27-fold, respectively. These metabolites are potent activators of glycogen phosphorylase and phosphofructokinase (PFK). Activation of glycolysis by AMP and P i is reinforced synergistica…

Accumulation of purine catabolites in solid tumors exposed to therapeutic hyperthermia

1996

Intensified adenosine triphosphate (ATP) degradation following therapeutic hyperthermia is often observed in solid tumors. As a result, accumulation of purine catabolites can be expected together with formation of protons at several stages during degradation to the final product, uric acid. Proton formation in turn can contribute to the development of heat-induced acidosis. Furthermore, oxidation of hypoxanthine and xanthine may result in generation of reactive oxygen species, which may lead to DNA damage, lipid peroxidation and protein denaturation, thus also contributing to heat-induced cytotoxicity. In hyperthermia experiments a tumor-size-dependent, significant increase in the levels of…

Hyperinsulinemia, hyperproinsulinemia and insulin resistance in the metabolic syndrome.

1996

For better comprehension of the metabolic syndrome, it is necessary to differentiate the effect of insulin on glucose metabolism on the one hand, and on other metabolic activities on the other hand. Whereas glucose utilization is affected by insulin resistance, the effect of insulin on lipid metabolism, ion and aminoacid transport does not seem to be diminished. Lipid metabolism, however, seems to play a crucial role in the induction of the vicious cycle. Increased energy and fat ingestion may be due to an increased number of galanin secreting cells in the hypothalamus. The excessive fat intake results in an increased rate of release of insulin and increased influx of triglycerides into the…

The regulation of trehalose metabolism in insects.

1996

Trehalose is a non-reducing disaccharide comprising two glucose molecules. It is present in high concentration as the main haemolymph (blood) sugar in insects. The synthesis of trehalose in the fat body (an organ analogous in function to a combination of liver and adipose tissue in vertebrates) is stimulated by neuropeptides (hypertrehalosaemic hormones), released from the corpora cardiaca, a neurohaemal organ associated with the brain. The peptides cause a decrease in the content of fructose 2,6-bisphosphate in fat body cells. Fructose 2,6-bisphosphate, acting synergistically with AMP, is a potent activator of the glycolytic enzyme 6-phosphofructokinase-1 and a strong inhibitor of the gluc…

Effectiveness and safety of once-daily aminoglycosides: A meta-analysis

1996

The effectiveness and safety of once-daily versus several-times-daily aminoglycosides were studied in a meta-analysis. MEDLINE for 1988 to 1995 was searched, and additional studies were identified from review articles and references in retrieved articles. Studies selected for meta-analysis were randomized controlled clinical trials in nonneutropenic adult patients comparing the clinical effectiveness or nephrotoxicity or ototoxicity of once-daily with several-times-daily aminoglycosides. Differences between groups were expressed as odds ratios. The results were combined by the procedure of Mantel and Haenszel, and 95% confidence intervals and exact confidence intervals were computed. An odd…

Effective conductivity in association with model structure and spatial inhomogeneity of polymer/carbon black composites

1996

The relationship between effective conductivity and cell structure of polyethylene/carbon composites as well as between effective conductivity and spatial distribution of carbon black are discussed. Following Yoshida's model both structures can, in a way, be said to be intermediate between the well known Maxwell-Garnett (MG) and Bruggeman (BR) limiting structures. Using TEM photographs on composites with various carbon blacks we have observed that the larger is Garncarek's inhomogeneity measure H of two-dimensional (2D) representative distribution of the carbon black, the smaller is the effective conductivity of the composite.

Resonant conversion of massless neutrinos in supernovae

1996

It has been noted for a long time that, in some circumstances, {\sl massless} neutrinos may be {\sl mixed} in the leptonic charged current. Conventional neutrino oscillation searches in vacuum are insensitive to this mixing. We discuss the effects of resonant massless-neutrino conversions in the dense medium of a supernova. In particular, we show how the detected $\bar\nu_e$ energy spectra from SN1987a and the supernova $r$-process nucleosynthesis may be used to provide very stringent constraints on the mixing of {\sl massless} neutrinos.

A new treatment for severe malabsorption due to radiation enteritis.

1996

Nuclear magnetic resonance imaging with hyperpolarised helium-3

1996

Abstract Summary Background Magnetic resonance imaging (MRI) relies on magnetisation of hydrogen nuclei (protons) of water molecules in tissue as source of the signal. This technique has been valuable for studying tissues that contain significant amounts of water, but biological settings with low proton content, notably the lungs, are difficult to image. We report use of spin-polarised helium-3 for lung MRI. Methods A volunteer inhaled hyperpolarised 3 He to fill the lungs, which were imaged with a conventional MRI detector assembly. The nuclear spin polarisation of helium, and other noble gases, can be greatly enhanced by laser optical pumping and is about 10 5 times larger than the polari…

L'actualité de la notion de « qualité donnant intérêt à agir »

1996

International audience

The Schouten - Nijenhuis bracket, cohomology and generalized Poisson structures

1996

Newly introduced generalized Poisson structures based on suitable skew-symmetric contravariant tensors of even order are discussed in terms of the Schouten-Nijenhuis bracket. The associated `Jacobi identities' are expressed as conditions on these tensors, the cohomological contents of which is given. In particular, we determine the linear generalized Poisson structures which can be constructed on the dual spaces of simple Lie algebras.

Absence of tolerance in duodenal ulcer patients treated for 28 days with a bedtime dose of roxatidine or ranitidine

1996

There is much experimental work on the occurrence of tolerance to the antisecretory effect of H2-receptor antagonists in healthy subjects, while data on its development in patients with duodenal ulcer are poor and conflicting. Moreover, this phenomenon has not been studied previously with 24 h gastric pH-metry in patients with active duodenal ulcer. For these reasons, we carried out a prospective pharmacodynamic investigation in 48 patients with endoscopically proven duodenal ulcer using the well-established once daily dosing schedule of H2 blockers. They were studied by means of 24 h continuous endoluminal pH-metry which was performed before, on d1 and d28 after receiving an oral bedtime d…

Serial examination of 20,248 newborn fetuses and infants: Correlations between drug exposure and major malformations

1996

Maternal medication during the first trimester of pregnancy has been discussed as a risk factor for development of birth defects. The correlation between maternal drug use and major malformations was investigated in a population-based case-control study in Mainz. Over a period of 5 years (1990–1994), 20,248 livebirths, stillbirths, and abortions underwent physical and sonographic examination, and anamnestic data were collected. A total of 1,472 births with congenital anomalies (cases) and 9,682 births without major and minor malformations (controls) were analyzed. We distinguished between 30 different drug categories, which were divided into medication taken continuously (before and during …

Clinical and ultrastructural findings in three patients with geleophysic dysplasia

1996

Geleophysic dysplasia, a rare disorder with autosomal-recessive inheritance, is characterized by short stature with a “happy-looking” facial appearance. Nonskeletal findings, particularly in an advanced stage, include hepatosplenomegaly and valvular cardiopathy. Based on the clinical picture and the detection of lysosome-like inclusions in hepatocytes, the underlying cause of the condition is considered to be a storage defect in the metabolism of glycoproteins. The clinical course, with progressive worsening of the condition favors this hypothesis. We report on 3 further cases, in which light and electron microscopic studies of iliac crest biopsies and cultured skin fibroblasts provided add…

Ein doppeltes Calix[4]aren in 1,3-alternate-Konformation

1996

Clinical and neuroradiological findings in classic infantile and late-onset globoid-cell leukodystrophy (Krabbe disease)

1996

In the present study the clinical course and imaging of early and late-onset forms of Krabbe disease are analyzed. We report on 11 patients with a biochemical diagnosis of galactosyl ceramide β-galactoside deficiency. Two presented as the classic infantile form and died within the second year of life. In 9 children the first clinical signs, such as gait difficulties and visual failure, started after age 2 years. All these patients developed slow regression of motor and mental capacities, and most of them died within their first decade. In patients of both groups computed tomography (CT) and magnetic resonance imaging (MRI) were performed. In the late-onset form, hypodensities of the central…

NMR Studies of Single-File Diffusion in Unidimensional Channel Zeolites

1996

Single-file diffusion is the restricted propagation of particles that cannot pass each other. The occurrence of this phenomenon should be reflected by a change in the time dependence of the mean particle displacement in comparison with ordinary diffusion. Although this process is considered to be the rate-controlling mechanism in a large variety of processes, so far no direct evidence of this phenomenon has been provided. Diffusion measurements made with pulsed field gradient nuclear magnetic resonance (NMR) in unidimensional pore systems (zeolites AlPO4-5 and Theta-1) reflect the expected time dependence of single-file diffusion.