Polyamine contents of human breast cancer cells treated with the cytotoxic agents chlorpheniramine and dehydrodidemnin B.

The cytotoxic agents chlorpheniramine and dehydrodidemnin B decreased the cell growth of estrogen receptor-negative human breast cancer cells MDA-MB231 and estrogen receptor-positive MCF-7, after 48 h treatment. Both agents reduced ornithine decarboxylase activity, but polyamine levels were increased in MDA-MB231 cells treated with dehydrodidemnin B. MCF-7 cells when treated with dehydrodidemnin B showed significant increases in spermidine and spermine contents.

Use of interferon-alpha in laryngeal papillomatosis: eight years of the Cuban national programme.

Laryngeal papillomatosis is one of the first diseases where interferon (IFN) was found to be effective. In 1983, a programme for the treatment of all such cases started in Cuba. Up to December 1991, 125 patients (92 children, 33 adults) have been treated: 102 with leucocyte IFN-alpha, 12 with recombinant IFN-alpha-2b, and 11 have received both preparations.

Submitochondrial localization and membrane topography of Ehrlich ascitic tumour cell glutaminase.

The intramitocondrial localization of the phosphate-activated glutaminase from Ehrlich cells has been examined by a combination of techniques, including: mitochondria subfractionation studies, chemical modification with sulfhydryl group reagents of different permeability, enzymatic digestion in both sides of the inner mitochondrial membrane, and immunological studies. Using alkaline extraction at high ionic strength, hypoosmotic shock and freezing-thawing cycle techniques, the enzyme was found in the particulate fraction. On the contrary, glutaminase activity was labile when subfractionation was carried out by digitonin/lubrol method; Western blot analysis localized the inactive enzyme in the matrix fraction.

Effect of spinal cord and peripheral nerve injury on human cutaneous sensory corpuscles. An immunohistochemical study.

This study was aimed at analyzing the changes in cutaneous sensory corpuscles from the territory of lesioned nerves and clinically denervated skin of patients with spinal cord injury using immunohistochemical methods. The morphological and biochemical characteristics of the Schwann-related cells of the mature sensory corpuscles (lamellar cells of Meissner corpuscles and inner-core of Pacinian corpuscles) depend upon the axon. To clarify whether this dependence requires structural and/or functional integrity of sensory axons we analyzed immunohistochemically some axonal, Schwann cell and perineurial cell antigens in cutaneous sensory corpuscles from i) the underlesional levels of patients with spinal cord injury affecting dorsal and lateral funiculi; ii) peripheral nerve entrapment, iii) sectioned and grafted nerves.

Apoptosis and autophagy in nigral neurons of patients with Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive cell loss confined mostly to dopaminergic neurons of the substantia nigra. Several factors, including oxidative stress, and decreased activity of complex I mitochondrial respiratory chain, are involved in the degenerative process. Yet, the underlying mechanisms leading to dopaminergic cell loss remain elusive.

Identification of a Zn(2+)-sensitive component of Ehrlich cell plasma membrane redox system by CHAPS-agarose-polyacrylamide electrophoresis and in situ staining of activity.

A procedure based on CHAPS-agarose-polyacrylamide electrophoresis and in situ staining of activity was used to detect a Zn(2+)-sensitive component of Ehrlich cell plasma membrane redox system. The procedure is so powerful that it allows to use crude plasma membrane fractions and can be easily adapted for use in an electrophoretic approach to the purification of this protein.

Effects of protein kinase C and phosphoprotein phosphatase modulators on Ehrlich cell plasma membrane redox system activity.

Diacyl glycerols and phorbol esters, which activate protein kinases C, stimulated Ehrlich ascites tumor cell ferricyanide reductase activity. On the contrary, selective inhibition of active protein kinases C with bis-indolyl maleimide did not change the rate of ferricyanide reduction by Ehrlich cells. Selective inhibitors of phosphoprotein phosphatases, okadaic acid and cyclosporin A, also stimulated plasma membrane redox system.

Cytoplasmic pH modulates the activity of the plasma membrane electron transport system in Ehrlich ascites tumour cells.

We report evidence for a modulation of Ehrlich cell plasma membrane redox activity by cytoplasmic pH. When Ehrlich cells were submitted to treatments leading to a slight decrease of cytoplasmic pH, there was a significant inhibition of plasma membrane ferricyanide reductase activity. However, those treatments which produced a slight alkalinization of the cytoplasm enhanced the activity of the plasma membrane redox system.

Immunocytochemical localization of allergenic proteins in Parietaria judaica L. (Urticaceae) pollen grains.

Inhalation of pollen grains and fungal spores leads to allergenic rhinitis and type I asthma mediated by IgE. The etiology of these conditions is due to the presence of substances that can induce anaphylactic processes in susceptible subjects. A combination of transmission electron microscopy with immunocytochemical methods was used to localize allergenic proteins in Parietaria judaica L.

[Supply of blood to heart surgery patients. Can transfusion habits be changed?].

Objective: In cardiac surgery, patients might receive unnecessary blood transfusions, due to the lack of a uniform criteria for blood replacement. We set out to evaluate the effect of a transfusion education program on the homologous blood requirements of subjects undergoing cardiac surgery.

Methods: In June of 1993 a transfusion education program based on international criteria was designed and put into effect in the intensive care unit.

Multiple transduction pathways regulate the sodium-extrusion gene PMR2/ENA1 during salt stress in yeast.

The yeast PMR2/ENA1 gene encodes an ATPase involved in sodium extrusion and induced by NaCl. At low salt concentrations (0.3 M) induction is mediated by the HOG-MAP kinase pathway, a system activated by non-specific osmotic stress.

Purification and characterization of a plasma membrane ferricyanide-utilizing NADH dehydrogenase from Ehrlich tumour cells.

A ferricyanide-utilizing NADH dehydrogenase (NADH-ferricyanide oxidoreductase) from the plasma membrane of Ehrlich ascites tumour cells has been purified about 1500-fold to apparent homogeneity. The method comprises the isolation of an enriched plasma membrane fraction, solubilization with Triton X-100, ion-exchange chromatography, ammonium sulphate precipitation, Cibacron Blue chromatography and fast-protein liquid chromatography with a Superose-6 gel filtration column. The specific activity of the final pool was more than 61 units/mg protein.

Three-dimensional analysis of the arrangement of compact chromatin in the nucleus of G0 rat lymphocytes.

The arrangement of compact chromatin of G0 lymphocytes was studied in three-dimensional reconstructions of the ensemble of the chromatin and of individual compact chromatin bodies. Rat spleen was serially cut and sections were contrasted with procedures preferential for DNA. Electron microscopy images were digitized, processed, and displayed using a commercial software package, complemented by a system for three-dimensional reconstruction and analysis developed by us on an IBM-compatible microcomputer provided with an image acquisition board.

Extensin-like Glycoproteins in the Maize Pollen Tube Wall.

We recently described the cloning and characterization of Pex1, a maize pollen-specific gene with an extensin-like domain. Here, we report that antibodies raised against a Pex fusion protein and a Pex synthetic peptide recognize a protein doublet with an apparent molecular mass of ~300 kD as well as larger proteins in pollen extracts. These proteins were not detected in extracts of seedling, endosperm, ear, silk, root, leaf, wounded leaf, meiotic tassel, or young microspore.

Ehrlich cell plasma membrane redox system is modulated through signal transduction pathways involving cGMP and Ca2+ as second messengers.

Ehrlich cell plasma membrane ferricyanide reductase activity increased in the presence of mastoparan, a generic activator of G proteins, using either whole cells or isolated plasma membrane-fractions. Agents that increase intracellular cAMP also increased the rate of ferricyanide reduction by Ehrlich cells. For the first time, evidence is shown on a modulation of plasma membrane redox system by cGMP.

Regional distribution of monoamine vesicular uptake sites in the mesencephalon of control subjects and patients with Parkinson's disease: a postmortem study using tritiated tetrabenazine.

The distribution of the vesicular monoamine transporter was investigated post mortem in the human ventral mesencephalon of control subjects (n = 7) and patients with Parkinson's disease (n = 4) using tritiated dihydrotetrabenzine binding and autoradiography. Tritiated dihydrotetrabenazine binding was characterized by a single class of sites with a Kd of 7 nM and a Bmax of 180 fmol/mg of protein in the substantia nigra. Tritiated dihydrotetrabenazine binding sites were heterogeneously distributed in the mesencephalon of control subjects: the density of tritiated dihydrotetrabenazine binding sites was high in the substantia nigra pars compacta, locus coeruleus and nucleus raphe dorsalis, moderate in the ventral tegmental area and low in the substantia nigra pars reticulata and catecholaminergic cell group A8.

Glutamine transport by vesicles isolated from tumour-cell mitochondrial inner membrane.

Mitochondrial-inner-membrane vesicles, isolated from Ehrlich ascites carcinoma cells by titration with detergents, accumulated L-glutamine by a very efficient transport system. The vesicles lack any phosphate-activated glutaminase activity, allowing measurement of transport rates without interference by L-glutamine metabolism. The time course of the transport was linear for the first 60 s, reaching a steady state after 120 min.

Tumor glutaminase purification.

Two alternative purification schemes to obtain the glutaminase from Ehrlich tumor cells in a highly purified form have been developed. One experimental approach is based on conventional and high-performance liquid chromatography fractionation techniques, yielding a 37-fold higher purification than has been previously reported. The method comprises: isolation of mitochondria, solubilization with Triton X-100, ion-exchange and hydroxyapatite chromatography, ammonium sulfate precipitation, and hydrophobic interaction chromatography.

[Extrapelvic endometriosis involving the perineum].

The ectopic endometriosis in the perineum is very rare (0.2% of ectopic endometriosis). We studied 16 cases of vaginoperineal endometriosis.

Cartographic system for spatial distribution analysis of corneal endothelial cells.

A combined cartographic and morphometric endothelium analyser has been developed by integrating the HISTO 2000 histological imaging and analysis system with a prototype human corneal endothelium analyser. The complete system allows the elaboration and analysis of cartographies of corneal endothelial tissue, and hence the in vitro study of the spatial distribution of corneal endothelial cells, according to their regional morphometric characteristics (cell size and polygonality). The global cartographic reconstruction is obtained by sequential integration of the data analysed for each microscopic field.

Characterization of plasma membrane redox activity from Ehrlich cells.

Ferricyanide reductase activity of plasma membranes isolated from Ehrlich ascites tumour cells was very sensitive to trypsin treatment. The decreases of activity observed after treatment with different glycosidases suggests that ferricyanide reductase is a glycoprotein. The opposite effects of phospholipase A2 and phospholipase C on the redox activity indicate that the phospholipidic environment plays an important role in the function of ferricyanide reductase.

Phosphate-activated glutaminase expression during tumor development.

Changes in phosphate-activated glutaminase activities determined in intact cells and isolated mitochondria have been followed during mouse Ehrlich ascites carcinoma development. Glutaminase activities parallel the levels of poly(A)+ RNAs encoding for the mitochondrial phosphate activated glutaminase. During the exponential growth phase, maximum activity was observed and the relative abundance of glutaminase mRNA significantly increased with regard to the stationary growth phase.