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Biomedical subjects

M Deutsch

Publications and source records attributed to M Deutsch.

At least 37 records · Page 2Linked to original sources
PubMed2003

Fulminant Mycoplasma pneumoniae infection with multi-organ involvement: a case report.

A 50-year-old man with no medical history was admitted because of progressive respiratory distress, aseptic meningitis, disseminated intravascular coagulation, cholestatic hepatitis, and renal failure. Mycoplasma pneumoniae infection was confirmed serologically. The patient was treated with erythromycin and showed a favorable recovery. Although M. pneumoniae infection is usually a benign, self-limited acute respiratory disease, on rare occasions it can manifest itself with a fulminant course and multi-organ involvement, even in normal healthy individuals.

Journal Article↗
PubMed2002

Structure of a Langmuir film on a liquid metal surface.

The structure of organic monolayers on liquid surfaces depends sensitively on the details of the molecular interactions. The structure of a stearic acid film on a mercury surface was measured as a function of coverage with angstrom resolution. Unlike monolayers on water, the molecules were found here to undergo a transition from surface-parallel to surface-normal orientation with increasing coverage. At high coverage, two condensed hexatic phases of standing-up molecules were found. At low coverage, a two-dimensional (2D) gas phase and condensed single- and double-layered phases of flat-lying molecular dimers were revealed, exhibiting a 1D longitudinal positional order. This system should provide a broader tunability range for nanostructure construction than solid-supported self-assembled monolayers.

Journal Article↗
PubMed2002

Demixing transition in a quasi-two-dimensional surface-frozen layer.

A thin/thick transition was observed by x-ray reflectivity in a surface-frozen crystalline bilayer on the surface of a molten binary mixture of long alcohols. This rare example of a solid-solid phase transition in a quasi-2D system is shown to result from an abrupt temperature-driven change in the layer's composition, kinetically enabled by the layer's ability to exchange molecules with the underlying 3D liquid bulk. Mean-field thermodynamics yields a Gibbs-adsorption-like expression which accounts very well for the transition.

Journal Article↗
PubMed2002

Tetra point wetting at the free surface of liquid Ga-Bi.

A continuous surface wetting transition, pinned to a solid-liquid-liquid-vapor tetra coexistence point, is studied by x-ray reflectivity in liquid Ga-Bi binary alloys. The short-range surface potential is determined from the measured temperature evolution of the wetting film. The thermal fluctuations are shown to be insufficient to induce a noticeable breakdown of mean-field behavior, expected in short-range-interacting systems due to their d(u) = 3 upper critical dimensionality.

Journal Article↗
PubMed2002

Analysis of early apoptotic events in individual cells by fluorescence intensity and polarization measurements.

Apoptosis is a dynamic process of variable duration. The ability to continuously detect the death process occurring in single or subgroups of cells is therefore very important in identifying apoptotic cells within a complex population. The Individual Cell Scanner (ICS), a multiparametric, multilaser-based scanning static cytometer, was used in the present report for the continuous monitoring of the apoptosis process. Fluorescence intensity (FI), polarization (FP), kinetic measurements, and cluster analysis of subpopulations were carried out utilizing various fluorescent probes. Hydrogen peroxide-induced apoptosis was monitored online in intact live lymphocytes by continuous sequential measurements of intracellular hyperpolarization. Plasma membrane asymmetry, mitochondrial membrane potential, and lysosomal rupture were monitored in individual cells. Cytoplasmic condensations, due to cell shrinkage and early lysosomal rupture, were found to be very early events of apoptosis. The new analytical capabilities suggested here may provide simple and convenient methods for detecting apoptosis from its earlier stages.

Apoptosis↗
PubMed2002

Differential aspects in ratio measurements of [Ca(2+)](i) relaxation in cardiomyocyte contraction following various drug treatments.

This study is concerned with the analysis of the time dependency of [Ca(2+)](i), monitored by indo-1-AM, via the ratiometric time response curve R(t) as measured during contractions of spontaneous or electrical stimulated cardiomyocytes (in culture). A mathematical formulation which describes the relaxation phase of R(t) was developed. By fitting formulation to the measured data of R(t), the extraction of characteristic parameters is feasible, which may reflect the factors regulating intracellular Ca concentration. The usefulness of the suggested formulation was examined by monitoring changes induced in those parameters following the exposure of the myocytes to different drugs, among which are: caffeine, ryanodine, thapsigargin db, cyclic AMP, isoprenaline, doxorubicin, and Cl-IB-MECA.

Adenosine↗
PubMed2002

Post-infantile giant cell hepatitis associated with autoimmune hepatitis and polyarteritis nodosa.

We report the case of a patient with corticosteroid-responsive giant cell hepatitis associated with typical manifestations and changes of polyarteritis nodosa from the kidney and central nervous system. Initially, the patient presented with transient right hemiparesis, followed by spontaneous remission without any abnormalities on computed tomography scan, magnetic resonance imaging and cerebrospinal fluid examination. A few months later he was admitted to our clinic because of icterus, peripheral oedema and abdominal distension. He was found to have clinical signs of active cirrhosis. Serological tests for hepatitis B, C and HIV virus were negative. Serum ceruloplasmin. a1-AT and ferritin levels were within normal limits. Antinuclear antibodies were positive (1: 160). Liver biopsy showed micronodular cirrhosis with many eosinophils in the portal tracts and giant hepatocytes with multiple nucleoli in the lobule. Fulfilling the diagnostic criteria for autoimmune hepatitis, he was started on treatment with prednisolone and azathioprine, resulting in both clinical and biochemical responses. Four years later he presented with severe pain at the right costovertebral angle. Ultrasonography revealed a haematoma at the right kidney, and selective angiography of the abdominal aorta, renal arteries and hepatic artery documented microaneurysms in both kidney and liver arteries. Because of severe haemorrhage, right nephrectomy was performed. Histology of kidney specimen showed characteristic lesions of polyarteritis nodosa. Several months later, while on treatment with prednisolone and cyclophosphamide, the patient experienced a fatal episode of brain haemorrhage. An association between autoimmune hepatitis, polyarteritis nodosa and postinfantile giant cell hepatitis has not been reported previously.

Adult↗
PubMed2001

Analysis of laser scattering pattern as an early measure of apoptosis.

Light scattering pattern analysis (LSPA) was applied in the current study for accurate and sensitive detection of subtle changes in cell size, which occur in mouse thymocytes undergoing apoptosis. The decrease in cell diameter as measured by LSPA was found to be an early signal of apoptosis preceding the externalization of phosphatidylserine on the outer membrane. When apoptosis was induced by dexamethasone, the change in cell size was dose and time dependent, and could be blocked by pretreatment of the thymocytes with N-acetylcysteine (NAC). This implies that the scattering pattern, when combined with fluorescent markers such as annexine-V, may be a powerful tool for early detection of apoptosis. Another advantage gained by the use of this method is the ability to repeatedly trace the same cells and to monitor the kinetics of their size changes.

Acetylcysteine↗
PubMed2001

Surface freezing in n-alkane solutions: the relation to bulk phases.

Surface freezing (SF) was investigated in tricosane-dodecane alkane solutions as a function of temperature (T) and molar concentration of tricosane (phi), using surface tension and synchrotron x-ray surface diffraction techniques. A crystalline SF monolayer, having a rotator R(II) structure, was found to exist for 35 degrees C</=T</=50 degrees C and 0.3</=phi</=1. The extended temperature range allowed to determine the linear-expansion coefficient of the SF monolayer, (dd/dT)/d=6.5 x 10(-4) degrees C-1. A simple thermodynamical model based on the theory of ideal solutions is shown to account well for the phi dependence of the SF temperature T(s)(phi). The study shows that the temperature range of existence of the surface frozen layer at each phi, the phi range over which SF is observed, and the bulk solidification behavior, are intimately related. All are determined by the rotator-liquid dissolution line T(dR)(phi).

Journal Article↗
PubMed2001

Positional order and thermal expansion of surface crystalline N-alkane monolayers.

We report a high-resolution synchrotron grazing incidence x-ray diffraction measurement of a surface crystalline monolayer at the liquid-vapor interface of the n-alkane eicosane (C20H42) just above its melting temperature. The peak width of the surface monolayer rotator phase is shown to be resolution limited and implies positional correlations of at least approximately 1 microm. The high resolution allowed determination of the temperature dependence of the peak position over the narrow (3 degrees C) temperature range of the surface crystal phase. The two-dimensional thermal expansion was determined to be (dA/dT)/A=1.8(+/-0.1)x10(-3) degrees C-1, which is comparable to the expansion in similar chain length bulk n-alkane rotator phases. Our data are consistent with the power-law shaped scattering tails expected from quasi-long-range order in two dimensions.

Journal Article↗
PubMed2001

Pairing interactions and Gibbs adsorption at the liquid bi-in surface: a resonant X-ray reflectivity study.

Resonant x-ray reflectivity measurements from the surface of liquid Bi(22)In(78) find only a modest surface Bi enhancement, with 35 at. % Bi in the first atomic layer. This is in contrast to the Gibbs adsorption in all liquid alloys studied to date, which show surface segregation of a complete monolayer of the low surface tension component. This suggests that surface adsorption in Bi-In is dominated by attractive interactions that increase the number of Bi-In neighbors at the surface. These are the first measurements in which resonant x-ray scattering has been used to quantify compositional changes induced at a liquid alloy surface.

Journal Article↗
PubMed2001

Clinical autologous in vitro endothelialization of 153 infrainguinal ePTFE grafts.

BACKGROUND: Over the past 17 years, our group has developed and clinically applied an in vitro endothelialization procedure whereby infrainguinal expanded polytetrafluoroethylene (ePTFE) prostheses are confluently lined with cultured autologous endothelial cells before implantation. After a successful randomized pilot study from 1989 to 1993, the procedure was adopted for routine operations. METHODS: Since June 1993, 153 endothelialized ePTFE grafts were implanted in the infrainguinal position in 136 patients (102 above knee (AK) and 51 below knee (BK), 89 men and 47 women, mean age 64.7+/-9.4 years). Seventeen patients received an endothelialized prosthesis bilaterally. Autologous endothelial cells were harvested from 4- to 5-cm segments of a subcutaneous vein (in 86% the cephalic vein), grown to first-passage mass cultures and confluently lined onto 6- (n = 113) or 7-mm (n = 40) inner diameter (ID) ePTFE grafts, precoated with fibrin glue. The observation period for 6-mm grafts was 7 years, and for 7-mm grafts was 4 years. Patency assessment for Kaplan-Meier survivorship analyses was based on duplex sonography and angiography. RESULTS: Kaplan-Meier survivorship function revealed a primary patency rate of 62.8% after 7 years (SE = 0.05) for all infrainguinal reconstructions (60% AK/70.8% BK). The primary patency for stage II and III patients was 64.4% after 7 years. The more recent group of 7-mm ID grafts showed a primary patency of 83.7% after 4 years. CONCLUSIONS: Our data provide strong evidence that autologous endothelial cell lining distinctly improves the patency of small diameter vascular grafts.

Aged↗