Integrins: role in cell adhesion and communication.

Adhesive interactions are crucial for the integrity and function of all cells and tissues. As one of the major families of cell adhesion receptors, the integrins have been the focus of scientific interest for more than a decade. The resulting studies have tremendously enhanced the understanding of integrin-mediated adhesive interactions and have unveiled novel integrin functions in the cytoskeletal organization of microfilaments and in the activation of diverse signaling pathways.

Papaverine injection into the hindlimb circulation stimulates ventilation in sheep.

To test the hypothesis, previously suggested by Huszczuk et al. (1993), that distention of the peripheral microvascular network could, per se, stimulate ventilation, the ventilatory effects of papaverine-induced muscular vasodilation were studied in ten anaesthetized sheep. Because systemic action of papaverine may involve the arterial baro- and chemoreceptors, the animals were surgically prepared for a reversible isolation of the hindlimb circulation.

Influence of the antioxidant N-acetylcysteine and its metabolites on damage induced by bleomycin in PM2 bacteriophage DNA.

Bleomycin is considered to be a useful model compound for studying environmental carcinogenesis, due to its broad spectrum of DNA damaging properties. In addition, bleomycin is a useful antitumor drug because of its cytotoxic properties. To investigate the influence of the antioxidant N-acetylcysteine and its metabolites glutathione and cysteine on bleomycin-induced DNA damage and more importantly to gain insight into the biological relevance of such damage, PM2 DNA was exposed to Cu(2+)-bleomycin in the presence and absence of the thiols N-acetylcysteine, glutathione and cysteine.

Biological consequences of DNA damage introduced in bacteriophage PM2 DNA by hydrogen peroxide-mediated free radical reactions.

In order to study the biological consequences of DNA damage induced by H2O2-mediated free radical reactions, DNA from bacteriophage PM2 was exposed to H2O2, Fe(3+)-citrate and ascorbate either alone or in combination. Induction of DNA lesions was determined as well as the biological activity of the phage DNA. Exposure to H2O2 alone resulted in max.

Differential regulation of vascular cell adhesion molecule-1 gene transcription by tumor necrosis factor alpha and interleukin-1 alpha in dermal microvascular endothelial cells.

As part of the inflammatory response, the localization of leukocytes depends to an important degree on cytokine-induced expression of vascular cell adhesion molecule-1 (VCAM-1) on endothelial cells (EC). We have previously shown that VCAM-1 expression is induced on human umbilical vein EC (HUVEC) by both tumor necrosis factor alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha), whereas on human dermal microvascular EC (HDMEC) only TNF alpha results in VCAM-1 expression. To explore molecular mechanisms responsible for these contrasting patterns of VCAM-1 induction in HUVEC versus HDMEC, we performed transcriptional activation studies with VCAM-1-based reporter constructs and in vitro binding assays using two adjacent NF-kappa B binding sequences of the VCAM-1 promoter as a DNA probe.

Selection of sounding channels for the High Resolution Dynamics Limb Sounder.

We describe the scientific design work behind the selection of the IR spectral passbands for the 21 sounding channels of the High Resolution Dynamics Limb Sounder (HIRDLS), which is scheduled to fly aboard the Earth Observing System chemistry platform at the beginning of the next century. At least one radiometer channel must be used for each gas that is being measured. Preferably the interfering contributions to the radiance by other gases in a channel should be small, but the principal requirements are that the desired emission be measured with high signal-to-noise ratio and that there be separate channels for the measurement of interfering species.

Satellite remote sensing of tropospheric CO and CH(4): forward model studies of the MOPITT instrument.

The Measurements of Pollution in the Troposphere (MOPITT) instrument is designed to measure tropospheric CO and CH(4) from a spaceborne platform by the use of infrared gas correlation radiometers. We describe the forward model that is used as the basis for the retrieval algorithm. We present the techniques used to model the instrument and describe the radiative transfer involved in the measurement process.

Classification of Fanconi anemia patients by complementation analysis: evidence for a fifth genetic subtype.

Fanconi anemia (FA) is an autosomal recessive disease with diverse clinical symptoms, life-threatening progressive panmyelopathy, and cellular hypersensitivity to cross-linking agents. Currently, 4 genetic subtypes or complementation groups (FA-A through FA-D) have been distinguished among 7 unrelated FA patients. We report the use of genetically marked FA lymphoblastoid cell lines representing each of the 4 presently known complementation groups to classify 13 unrelated FA patients through cell fusion and complementation analysis.

Vascular distension in muscles contributes to respiratory control in sheep.

It has recently been proposed that afferent fibers from skeletal muscle could sense the state of the microvascular circulation, linking ventilation to the degree of peripheral perfusion or vascular distension (Huszczuk et al., Respir. Physiol.

Mutagenicity of metabolic oxygen radicals in mammalian cell cultures.

Reactive oxygen species produced by normal cellular metabolism have been considered to play a causative role in spontaneously occurring genomic instability and carcinogenesis. To study the genotoxic consequences of an enhanced flux of metabolically produced reactive oxygen species, cells may be exposed to hyperoxia (elevated concentrations of oxygen), a condition known to generate high levels of microscopically visible chromosomal damage. Here we assess the mutagenic potential of normobaric hyperoxia in several mammalian cells lines (CHO-K1-BH4 and AS52 Chinese hamster cells and TK6 human lymphoblastoid cells) using different target genes, including hprt, xprt and tk.

A factor in human plasma permits persistent expression of E-selectin by human endothelial cells.

E-selectin is an inducible endothelial cell adhesion protein that is a critical element in the binding of leukocytes to activated endothelial cells. It is induced by a variety of pro-inflammatory soluble substances including interleukin-1 (IL-1), tumor necrosis factor (TNF), or bacterial lipopolysaccharide (LPS). In vitro studies of a large vessel endothelial cells demonstrate that stimulation with TNF or IL-1 leads to a rapid, but transient, induction of E-selectin expression that disappears within 24 hours.

Extracorporeal circulation in European Economic Community (ECC in EEC): 1979-1989.

This study determines the evolution of ECC in EEC. After recollecting the great stages of ECC since its routinely use in open heart surgery, the study situates its position in the entire world taking into account several indexes like the Gross National Product (GNP) and its evolution, the life expectancy and some other factors either technical or economical. Only a coarse analysis could be done for Europe due to an unsteady evolution.

Mechanism of hyperoxia-induced chromosomal breakage in Chinese hamster cells.

Exposure of cell cultures to hyperoxia, i.e., an atmosphere containing more than 20% O2, results in various genotoxic effects.

Cell culture models for oxidative stress: superoxide and hydrogen peroxide versus normobaric hyperoxia.

According to the free radical theory of aging, loss of cellular function during aging is a consequence of accumulating subcellular damage inflicted by activated oxygen species. In cells, the deleterious effects of activated oxygen species may become manifest when the balance between radical formation and destruction (removal) is disturbed creating a situation denoted as 'oxidative stress'. Cell culture systems are especially useful to study the effects of oxidative stress, in terms of both toxicity and cellular adaptive responses.

EC CO2R: oxygenator or hemodialyzer? An in vitro study.

In respiratory support of patients with acute respiratory distress syndrome (ARDS), the extracorporeal CO2 removal (EC CO2R) technique should be the earliest and easiest procedure so as to have the lowest blood flow rate. Extracorporeal circulation (ECC) can be achieved using an oxygenator for CO2 removal under the dry form (dissolved CO2) or a hemodialyser for CO2 removal under the wet form (bicarbonates). This study investigated different methods allowing an increase in CO2 transfer, using liquid flow rates up to 0.

[Use of extracorporeal circulation oxygenators (CEC) in the European Economic Community (EEC)].

This study analyses the growth of CPB in the EEC. The study situates its position in the world taking into account several indexes such as the Gross National Product and its growth the life expectancy and other technical or economic factors. Only a broad analysis could be performed for Europe to the irregular development of CPB.

[CO2 elimination via extracorporeal circulation in respiratory assistance: artificial lung or kidney? Experimental study].

In the context of a respiratory assistance protocol dissociating oxygenation of the blood from elimination of carbon dioxide, it is possible to rest the lungs which are used for oxygen exchange by diffusion via functional zones. CO2 is eliminated via extracorporeal circulation. In order to simplify this method, the authors investigated the optimal conditions for this elimination at flow rates similar to those used for haemodialysis (0.

Effect of iron chelators on the cytotoxic and genotoxic action of hyperoxia in Chinese hamster ovary cells.

The iron chelators o-phenanthroline and desferrioxamine were tested for their ability to protect Chinese hamster ovary cells against the cytotoxic and genotoxic effects of normobaric hyperoxia. Desferrioxamine added at sub-toxic concentrations (up to 2.5 microM) over a period of several days had no protective effect on hyperoxia-induced clonogenic cell killing and growth inhibition.

Effect of antioxidants on hyperoxia-induced chromosomal breakage in Chinese hamster ovary cells: protection by carnosine.

We have studied the effect of various compounds, known as antioxidants, on the level of hyperoxia (80-90% O2)-induced chromosomal aberrations in Chinese hamster ovary cells: ascorbic acid, alpha-tocopherol, carnosine, imidazole-4-acetic acid, glutathione monoethylester, N-acetylcysteine and ethoxyquin. Carnosine (beta-alanyl-histidine) appeared to be the only compound that reduced chromosomal breakage. The effect was also present in cultures post-treated with caffeine (at 2.

Flow-cytometric analysis of the DNA-content in paraffin-embedded tissue from colorectal carcinomas and its prognostic significance.

The nuclear DNA content of 163 colorectal carcinomas was determined by flow-cytometry (FCM) on formalin-fixed, paraffin-embedded tissue. DNA-aneuploidy was found in 97 cases (59.5%), in which no statistically significant correlations with sex, mean age, tumour stage (Dukes and pTNM) and tumour grade were noted.

Monitoring of blood gases during extracorporeal circulation with an artificial lung.

During cardiopulmonary bypass, the heart-lung machine and the patient's gas exchange systems (uptake and elimination) form an undissociable couple. Changes in one of the components lead to corresponding changes in the other. In the artificial lung, like in the natural lung and peripheral tissues, gas exchanges depend on several parameters: blood inlet conditions, blood flow rate, temperature, composition of the gas mixture used for ventilation, blood tissue perfusion, O2 consumption, etc.

[Retrospective flow-cytometric analysis of the DNA content in colorectal carcinomas and the test of the prognostic significance of DNA ploidy].

The nuclear DNA content of 163 colorectal carcinomas was determined by flow-cytometry (FCM) on formalin-fixed and paraffin-embedded tissue. DNA-aneuploidy was found in 97 cases (59.5%), without correlation to sex, mean age, tumor-stage (DUKES and pTNM) and grading.

Metabolic CO2 removal by dialysis: THAM vs NaOH infusion.

New methods of respiratory support are needed to reduce the high mortality rate of acute respiratory failure. To simplify the procedures of extracorporeal CO2 elimination under apneic oxygenation, one approach is to replace the membrane lung by a hemodialyzer and to administer an alkali, since hemodialysis requires a lower blood flow rate than blood-gas exchange. This study compared the effectiveness of trishydroxymethyl aminomethane (THAM) and NaOH in this procedure.