Prolonged in vitro culture modifies the surface lipid composition of murine melanoma cell lines.

Lipid composition of two murine melanoma cell variants (B16, without malignant properties and B16-F10, with high metastatic activity), has been examined at different stages of growth. The aim of the work was to identify cell surface modifications due to the time length of in vitro culture, that could be one variable to consider when metastatic potential is studied. Some of the analyzed parameters (ganglioside- and glycoprotein-bound neuraminic acid, cholesterol, neutral glycolipids, phospholipids, triacylglycerols) undergo statistically significant variations at the various passages in B16-F10 line.

Total glycolipid and glucosylceramide content in serum and urine of patients with Gaucher's disease type 3 before and after enzyme replacement therapy.

The follow-up of Gaucher's patients under enzyme replacement therapy is generally based both on the clinical aspects and the evaluation of haematological parameters: haemoglobin level, platelet count, acid and alkaline phosphatase activities. Spleen and liver volumes are also reliable criteria for evaluating the improvement of the patients. The determination of glycolipid excretion in the urine and/or the quantification of glycolipids in serum can also be a useful tool for the screening and the follow up of patients with lysosomal storage disease including Gaucher's disease.

Prolonged in vitro culture modifies the surface lipid composition of murine melanoma cell lines.

Lipid composition of two murine melanoma cell variants (B16, without malignant properties and B16-F10, with high metastatic activity), has been examined at different stages of growth. The aim of the work was to identify cell surface modifications due to the time length of in vitro culture, that could be one variable to consider when metastatic potential is studied. Some of the analyzed parameters (ganglioside- and glycoprotein-bound neuraminic acid, cholesterol, neutral glycolipids, phospholipids, triacylglycerols) undergo statistically significant variations at the various passages in B16-F10 line.

Polarized distribution of Na+/H+ exchanger isoforms in rabbit collecting duct cells.

The present study describes two Na+/H+ exchanger (NHE) isoforms in an immortalized rabbit renal cortical collecting tubule cell line (RC.SV3). Na+/H+ exchange activity was assayed using fluorescence measurements of intracellular pH (pHi) in monolayers mounted in a cuvette containing two fluid compartments, making it possible to independently measure Na+/H+ exchange activity on either the apical or basolateral surface.

Hypoxia affects cytokine production and proliferative responses by human peripheral mononuclear cells.

We have shown that hypoxia (2% O2 approximately pO2 14 mmHg) as opposed to O2 atmospheric pressure (20.9% O2 approximately pO2 140 mmHg) can deeply affect the production of cytokines in human peripheral mononuclear cells (PBMC) in the presence or absence of a specific T-cell activator such as phytohemagglutinin (PHA). In hypoxia, interleukin (IL)-2, IL-4, and interferon (IFN)-gamma production increased by 110, 70, and 50% over that of controls, respectively, in PHA-stimulated PBMC (P < 0.

Electrophysiological properties of vestibular sensory and supporting cells in the labyrinth slice before and during regeneration.

The whole cell patch-clamp technique in combination with the slice preparation was used to investigate the electrophysiological properties of pigeon semicircular canal sensory and supporting cells. These properties were also characterized in regenerating neuroepithelia of pigeons preinjected with streptomycin to kill the hair cells. Type II hair cells from each of the three semicircular canals showed similar, topographically related patterns of passive and active membrane properties.

Coexistence of alpha1 and beta adrenergic receptors in the liver of the frog Rana esculenta, the toad Bufo bufo, the lizard Podarcis sicula campestris, and the turtle Pseudemys picta elegans.

In mammals and birds the characteristics of alpha1 adrenergic receptors and their biological role in liver metabolism have been clearly described, although the predominance of receptor subtypes varies with species. In contrast, the actual presence of hepatic alpha1 adrenergic receptors in fish, amphibians, and reptiles has been questioned. Only recently has their existence been demonstrated in some fish species and also in the wood frog Rana sylvatica.

Ionic currents in regenerating avian vestibular hair cells.

By applying the conventional whole-cell patch-clamp technique in combination with the slice procedure, we have investigated the properties of avian semicircular canal hair cells in situ. Passive and active electrical properties of hair cells from control animals have been compared with those of regenerating hair cells following streptomycin treatment (that killed almost all hair cells). Regenerating type II hair cells showed patterns of responses qualitatively similar to those of normal hair cells.

Cytokines in mammalian reproduction and speculation about their possible involvement in nonmammalian viviparity.

In recent years, the secretion of immunoregulatory factors (cytokines) at the maternofetal interface in mammals has been widely documented. Although cytokine production seems to be a specific phenomenon in mammalian reproduction, the specific roles of these substances in different species are still not clear. However, a balance of different cytokine activities appears to be crucial for regulation of the establishment and survival of the semiallogeneic embryo in maternal tissues.

Polarization of adenosine effects on intracellular pH in A6 renal epithelial cells.

The effect of adenosine on Na+/H+ exchange activity was examined in cultured A6 renal epithelial cells. Adenosine and its analogue N6-cyclopentyladenosine (CPA) had different effects on Na+/H+ exchange activity depending on the side of addition. Basolateral CPA induced a stimulation of Na+/H+ exchange activity that was completely prevented by preincubation with an A2A-selective antagonist, 8-(3-chlorostyryl)caffeine, whereas apical CPA induced a slight but significant inhibition of Na+/H+ exchange activity that was significantly reduced by the A1-receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine.

Glycosphingolipid expression in solid tumours and transformed cell lines.

Glycosphingolipids are assumed to play a crucial role in cell-cell and cell-substrate interactions, including cell adhesion, proliferation, differentiation and apoptosis. Furthermore, cell surface glycolipid profile changes in the so called "social disorders", such as malignant transformation. To better investigate these modifications, the ganglioside composition in different solid tumours and in two transformed cell lines was analyzed.

Short cycles of both static and pulsed electromagnetic fields have no effect on the induction of cytokines by peripheral blood mononuclear cells.

We evaluated the effect of short cycles of static and pulsed electromagnetic field exposure on the eventual activation of peripheral blood mononuclear cells. The cells were subjected to three 15-min cycles of EMF, each exposure being followed by 105 min without a field, for a total of 6 hr. The results clearly demonstrate that the proliferative responses of both normal cells and cells stimulated with 1 microg/ml phytohemagglutinin were not distinguishable from control cells not exposed to EMF.

Activities of glycolipid glycosyltransferases and sialidases during the early development of Xenopus laevis.

The activities of glycosyltransferases and sialidases, together with the ganglioside content and distribution, have been extensively studied in mammals, while the informations on tissues of other animals, including amphibian, are scarce. In this paper we present data on the activities of SAT-1, SAT-2, SAT-4, SAT-5, GlcNAcT-1, GalNAcT-1, GalT-6, and sialidases studied in Xenopus laevis embryos at different stages of development. The highest activity was found at days 4 and 5 of embryogenesis for glycosyltransferases and sialidases respectively; a tentative correlation between the in vitro activity of these enzymes and the content of neutral and acidic glycolipids is discussed.

Pulmonary catabolism of interleukin 6 evaluated by lung perfusion of normal and smoker rats.

Cytokines such as interleukin 6 are involved in the pulmonary inflammation arising as a result of smoking. By use of isolated and perfused lung preparations we have evaluated the role of the lungs in the catabolism of human recombinant interleukin 6 both in normal rats and in rats subjected to an acute cigarette smoking episode. When interleukin 6 was incorporated into the lung perfusion medium, neither control nor smoke-exposed rat lungs cleared the cytokine and only 0.

Inactivation of delayed rectifier K+ current in semicircular canal hair cells.

Some properties of the inactivation process of delayed rectifier K+ current (Ik) were investigated in vestibular hair cells of the central region of frog crista ampullaris. These cells were chosen since they exhibited a very large Ik. Experiments were performed on thin slices of sensory epithelium using the whole-cell variant of the patch-clamp technique.

Thrombin modulation of natural killer activity in human peripheral lymphocytes.

In addition to its pivotal role in the coagulation cascade, thrombin is mitogenic for fibroblasts and endothelial cells, and activates a number of inflammatory cells including monocytes and T-lymphocytes. To determine if other immune functions are modulated by thrombin and if this modulation is direct or indirect, we investigated whether highly purified human alpha-thrombin affects natural killer (NK) and lymphokine-activated killer (LAK) cell-mediated cytotoxicity. Thrombin enhanced NK cell-mediated cytotoxicity by more than 60% and enhanced IL-2 production and NK 3.

Potassium currents of pear-shaped hair cells in relation to their location in frog crista ampullaris.

Voltage-dependent K+ currents in pear-shaped hair cells of the frog crista ampullaris were investigated in thin slice preparations using the whole-cell variant of the patch-clamp technique. Microscopy observation revealed that pear-shaped cells are located in intermediate and peripheral regions of the crista, whereas they are absent in the central region. Voltage-clamp recordings in cells from the peripheral regions revealed that the total outward K+ current could be separated pharmacologically into three distinct components: a A-type K+ current (IA); an inactivating calcium-activated K+ current (IK(Ca)) and a delayed rectifier K+ current (IK).

Effectiveness of pentoxifylline in semen preparation for intrauterine insemination.

Pentoxifylline, an inhibitor of cAMP phosphodiesterase activity, favours intracellular cAMP concentration increase. In-vitro treatment of semen with pentoxifylline leads to marked augmentation of sperm motility, enhancement of acrosome reaction, increase of sperm penetration into zona-free hamster oocytes, and protection of the sperm plasma membrane. Such properties indicate that the drug may be a useful tool for semen preparation in assisted reproduction, but its real effectiveness in improving fertilization rates is still uncertain, mainly in association with intrauterine insemination (IUI).

Effect of adenosine on Na+ and Cl- currents in A6 monolayers. Receptor localization and messenger involvement.

The effect of adenosine regulation on sodium and chloride transport was examined in cultured A6 renal epithelial cells. Adenosine and its analogue N6-cyclopentyladenosine (CPA) had different effects on short-circuit current (Isc) depending on the side of addition. Basolateral CPA addition induced an approximately threefold increase of the Isc that reached a maximum effect 20 min after addition and was completely inhibited by preincubation with either an A2 selective antagonist, CSC, or the sodium channel blocker, amiloride.

Ganglioside long-chain base composition of rat brain subcellular fractions after chronic ethanol administration.

Rats of two different ages (2 and 7 months) were treated with an ethanol-containing liquid diet for 24 days and change of the ceramide composition of gangliosides were studied in the brain synaptosomal, microsomal and myelin fractions. Greater differences were observed in the younger age, where ethanol treatment caused a significant increase of C20:1 LCB in GM1 ganglioside of synaptosomes and microsomes and in GD1a of myelin.

Ozone as a bioregulator. Pharmacology and toxicology of ozonetherapy today.

The disinfectant activity of ozone is well recognized and ozone is used worldwide for sterilization of water. The use of ozone as a complementary medical approach is less known, because it has mostly been used in an empirical fashion without a rational basis and appropriate controls. In spite of this drawback, the use of judicious and standardized ozone dosages can elicit the formation of ROS acting as natural physiological activators of several biological functions.

Age-related effects of chronic ethanol intake on physical properties, lipid composition and galactosyltransferase activity of rat small intestine microsomes.

The effect of a 4-week ethanol administration on: (1) glycoprotein content of brush border membrane (BBM): (2) galactosyltransferase activity; (3) lipid composition and fluidity of intestinal microsomes prepared from young and adult rats was investigated. In spite of a lower alcohol consumption, the more dramatic effects of treatment have been observed in the older rats, where BBM protein-bound hexoses and microsomal galactosyltransferase activity were significantly decreased. On the contrary, these parameters were unaffected in young rats.

Does ozone therapy normalize the cellular redox balance? Implications for therapy of human immunodeficiency virus infection and several other diseases.

The role of ozone on earth is controversial, as in the stratosphere it is protective against excessive ultra violet irradiation, and in the troposphere it is toxic for animals and plants. The effectiveness of ozone against pathogens is well recognized and ozone appears to be the best agent for sterilization of water. In spite of this, the use of ozone in medicine has been overlooked or despised, mostly because it has been either misused or used without appropriate controls.

Antioxidant vitamins and immunodeficiency.

On the plasma of 20 children from 1 to 6 years old with HIV infection, the following analyses were carried out: vitamin assays (vitamin E and beta-carotene), hematochemical assays, and immunoassays. From the body of our results it emerged that in the seropositive children considered, in addition to the already well-known alterations of the hematic and immune situation, there is a state of hypovitaminosis involving the most important antioxidant vitamins.