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M J Weiss

Publications and source records attributed to M J Weiss.

At least 73 records · Page 4Linked to original sources
PubMed1986

Isolation and characterization of a cDNA encoding a human liver/bone/kidney-type alkaline phosphatase.

Alkaline phosphatases (ALPs) [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] isolated from human liver, bone, and kidney (L/B/K) exhibit very similar biochemical and immunologic properties that differentiate them from other human ALPs, such as those characteristically found in placenta and intestine. Despite their similarities, the L/B/K ALPs produced in different tissues show slight physical differences. To examine structural and evolutionary relationships between the various ALPs, a cDNA corresponding to L/B/K ALP mRNA has been isolated. A lambda 11 cDNA expression library was constructed using poly(A) RNA from the osteosarcoma cell line Saos-2 and screened with anti-liver ALP antiserum. The 2553-base-pair cDNA contains an open reading frame that encodes a 524 amino acid polypeptide with a predicted molecular mass of 57.2 kDa. This ALP precursor protein contains a presumed signal peptide of 17 amino acids followed by 37 amino acids that are identical to the amino-terminal sequence determined from purified liver ALP. In addition, amino acid sequences of several CNBr peptides obtained from liver ALP are found within the cDNA-encoded protein. The deduced L/B/K ALP precursor polypeptide shows 52% homology to human placental ALP and 25% homology to Escherichia coli ALP precursor polypeptides. Sixty percent nucleotide homology exists between the human L/B/K and placental cDNAs over the protein coding regions. The 5' and 3' untranslated regions of the L/B/K ALP cDNA, 176 and 805 base pairs, respectively, show no homology to the corresponding regions of placental ALP cDNA.

Alkaline Phosphatase↗
PubMed1986

The T11 glycoprotein is functionally linked to a calcium channel in precursor and mature T-lineage cells.

Human T lymphocytes are activated through either the antigen/major histocompatibility complex receptor (T3-Ti) or the T11 sheep erythrocyte-binding protein. Spectrofluorimetry and multiparameter flow cytometric techniques were utilized to examine the relationship of activation to alterations in cytoplasmic free calcium concentration, [Ca2+]i. T3-Ti receptor-triggered elevation in [Ca2+]i was found to be dependent in large part (approximately equal to 80%) on extracellular Ca2+ and to a much smaller extent (approximately equal to 20%) on mobilization of internal Ca2+ pools. Furthermore, T11-mediated increases in [Ca2+]i were entirely dependent on extracellular Ca2+. Though the kinetics of [Ca2+]i changes induced by monoclonal antibodies to T3-Ti and T11 differed, both pathways were otherwise similar, particularly with regard to effects on or mediated by the plasma membrane potential. Importantly, the T11 pathway was found to be functional in precursor T-lineage cells lacking the surface T3-Ti complex. These findings suggest that there may be a plasma membrane Ca2+ channel functionally or physically linked to the T11 structure or, alternatively, that there is a set of related T11- and T3-Ti-associated Ca2+ channels.

Animals↗
PubMed1985

Mitochondrial and plasma membrane potentials cause unusual accumulation and retention of rhodamine 123 by human breast adenocarcinoma-derived MCF-7 cells.

Quantitative studies of MCF-7 cells (derived from human breast adenocarcinoma) and CV-1 cells (from normal African green monkey kidney epithelium), using the permeant cationic compound tetraphenylphosphonium (TPP), in conjunction with fluorescence microscopy using rhodamine 123 (Rh123), indicate that the mitochondrial and plasma membrane potentials affect both uptake and retention of these compounds. Under conditions that depolarize the plasma membrane, uptake and retention of TPP and Rh123, driven only by the mitochondrial membrane potential, is greater in MCF-7 than in CV-1. An ionophore that dissipates the mitochondrial membrane potential of MCF-7 cells causes them to resemble CV-1 cells by decreasing uptake and retention. Hyperpolarizing the mitochondrial membrane of CV-1 increases accumulation and prolongs retention; hyperpolarization of the plasma membrane further heightens this effect, causing the uptake of CV-1 cells to resemble that of MCF-7 cells even more closely. The greater uptake and retention by MCF-7 appears to be a consequence of elevated mitochondrial and plasma membrane potentials. The plasma membrane potential affects mitochondrial retention of TPP and Rh123 and its role in enhancing the effect of a difference in mitochondrial membrane potential is explained.

Adenocarcinoma↗
PubMed1985

Selective killing of carcinoma cells "in vitro" by lipophilic-cationic compounds: a cellular basis.

Lipophilic positively-charged compounds are facilitated across biological membranes by the transmembrane potential of intact cells. One such compound, rhodamine 123, has recently been shown to be selectively toxic toward a variety of transformed (carcinoma), epithelial cells in vitro (Lampidis et al., 1982; Bernal et al., 1982; Lampidis et al., 1983). A mechanism that could account for the selectivity of this agent would be a difference in the plasma membrane potential between normal and carcinoma cells. We report here that a significantly higher transmembrane potential has been found in a pair of carcinoma (83 mV for human breast and -99 mV for human cervix) as compared to normal (-56 mV for marsupial kidney and -48 mV for monkey kidney) epithelial cell lines. We also identified 3 other positively-charged lipophilic compounds, safranin 0, rhodamine 6G and tetraphenylphosphonium chloride (TPP+), which show selective toxicity toward carcinoma cells in vitro, while an uncharged lipophilic analog, rhodamine 116, does not. These data suggest that the higher plasma membrane potential of carcinoma cells may in part contribute to the preferential accumulation and selective toxicity of the lipophilic cationic compounds we have examined. An extension of this concept to an in vivo environment could lead to a class of cationic compounds which selectively exploit differences between normal and carcinoma cells.

Animals↗
PubMed1984

The Yc and Ya subunits of rat liver glutathione S-transferases are the products of separate genes.

Rat liver glutathione S-transferases consist of binary combinations of three major classes of subunits designated as Ya (Mr = 25,600), Yb (Mr = 27,000) and Yc (Mr = 28,000). We have determined the nucleotide sequences of a cDNA insert in pGTR262 containing partial sequence of a Yc subunit. Sequence comparison with a Ya subunit cDNA clone pGTR261 revealed 70% nucleotide sequence homology and 65% amino acid sequence homology in the overlapping coding regions. Approximately 65% of the amino acid substitutions between these two subunits occur in clusters of two to eight residues. The 3' noncoding sequences of these two subunit cDNA clones are highly divergent in length and in sequences. The 3' noncoding region of pGTR262 cDNA contains open reading frames of 23, 39, and 13 amino acids which are in phase with the deduced Yc subunit sequences but interrupted by termination codons. By RNA blot hybridization analysis, we found that this Yc subunit sequence expression is tissue specific. It is expressed at a reduced level in kidney and testis as compared with liver and hardly at all in heart, lung, seminal vesicles, and spleen. We suggest that the mechanism for the tissue-specific expression of the Yc subunit of rat liver glutathione S-transferases may occur at or prior to the level of RNA processing. From the divergent DNA sequences between the Ya and Yc subunits reported in this communication and their differential induction upon acute phenobarbital administration reported by Pickett et al. (Pickett, C.B., Donohue, A. M., Lu, A. Y. H., and Hales, B. F. (1982) Arch. Biochem. Biophys. 215, 539-543) we propose that the Ya and Yc subunits of rat liver glutathione S-transferases are encoded by separate gene families or transcriptional units.

Amino Acid Sequence↗
PubMed1984

The nucleotide sequence of a rat liver glutathione S-transferase subunit cDNA clone.

We have determined the nucleotide sequence of a cloned cDNA derived from liver poly(A) RNA of pentobarbital-treated rats encoding a glutathione S-transferase subunit. This cDNA clone pGTR261 contains one open reading frame of 222 amino acids, a complete 3' noncoding region, and 63 nucleotides in the 5' noncoding region. The cloned DNA hybridizes to rat poly(A) RNA in a tissue-specific fashion, with strong signals to liver and kidney poly(A) RNA(s) of approximately 1100 and approximately 1400 nucleotides in size but little or no hybridization to poly(A) RNAs from heart, lung, seminal vesicles, spleen, or testis under stringent conditions. Our sequence covers the cDNA sequence of pGST94 which contains a partial coding sequence for a liver glutathione S-transferase subunit of Ya size. Comparison of sequences with our earlier clone pGTR112 suggests that there are at least two mRNA species coding for two different subunits of the Ya (Mr = 25,600) subunit family with very limited amino acid substitutions mainly of conserved polarity. The divergent 3' noncoding sequences should be useful molecular probes in differentiating these two different but otherwise very similar subunits in induction and genomic structure analyses. Our results suggest that tissue-specific expression of the glutathione S-transferase subunits represented by the sequences of pGTR261 and pGTR112 may occur at or prior to the level of RNA processing.

Amino Acid Sequence↗
PubMed1984

Rhodamine 123 inhibits bioenergetic function in isolated rat liver mitochondria.

Rhodamine 123 accumulates in the mitochondria of living cells and exhibits selective anticarcinoma activity. The biochemical basis of toxicity was investigated by testing the effect of the dye on isolated rat liver mitochondria. Much lower concentrations of rhodamine 123 were required to inhibit ADP-stimulated respiration and ATP synthesis in well-coupled energized mitochondria than were required to inhibit uncoupled respiration and uncoupler-stimulated ATP hydrolysis. The amount of rhodamine 123 associated with the mitochondria was several-fold greater under energized as compared to non-energized conditions, which may explain why coupled functions appeared to be more sensitive than uncoupled functions to inhibition at low concentrations of rhodamine 123. It was concluded that the site of rhodamine 123 inhibition is most likely the F0F1 ATPase complex and possibly electron transfer reactions as well.

2,4-Dinitrophenol↗
PubMed1984

Localization of endoplasmic reticulum in living and glutaraldehyde-fixed cells with fluorescent dyes.

Certain fluorescent dyes, previously reported to localize mitochondria, when used at higher concentrations also localize a continuous net-like structure in both living and glutaraldehyde-fixed cells. A similar reticular structure can be detected by phase-contrast microscopy and whole-mount electron microscopy in potassium permanganate-fixed cells as well. This structure is mostly tubular, with some patch-like areas, and is likely to be the endoplasmic reticulum (ER). The organization of the reticular structure is sensitive to colchicine and rotenone but not to cytochalasin B, taxol, monensin, the calcium ionophore A23187, 12-O-tetradecanoylphorbol 13-acetate, or hydrocortisone.

Animals↗
PubMed1984

Calcium dependency of antigen-specific (T3-Ti) and alternative (T11) pathways of human T-cell activation.

Human T lymphocytes are activated by two lineage-specific surface components: the antigen/major histocompatibility complex receptor (T3-Ti) and the unrelated T11 molecule. Interaction of either of these with their respective ligands leads to T-cell proliferation via an interleukin 2(IL-2) dependent autocrine mechanism. To begin to characterize the molecular details of the activation process, the role of Ca2+ was examined using human T-cell clones and monoclonal antibodies directed against their surface components. Here, we show that within minutes of triggering either the T3-Ti or T11 molecule, there is a large increase in intracellular Ca2+ concentration, as measured by quin-2 fluorescence. This is essential for induction of T-cell proliferation in inducer, suppressor, and cytotoxic clones and therefore presumably is required at an early step in the autocrine growth pathway. Thus, chelating exogenous Ca2+ with EGTA specifically inhibits proliferation triggered by anti-T3-Ti or anti-T11 monoclonal antibodies, but it does not affect triggering by exogenous IL-2. In addition, the Ca2+ ionophore A23187 can, by itself, initiate clonal proliferation.

Antibodies, Monoclonal↗
PubMed1983

Tissue-specific expression of the rat glutathione S-transferases.

Tissue-specific patterns of rat glutathione S-transferase expression have been demonstrated by in vitro translation of purified poly(A) RNAs and by protein purification. Poly(A) RNAs from six rat tissues including heart, kidney, liver, lung, spleen, and testis were used to program in vitro translation with the rabbit reticulocyte lysate system and [35S]methionine. The glutathione S-transferase subunits synthesized in vitro were purified from the translation products by affinity chromatography on S-hexylglutathione-linked Sepharose 6B columns. The affinity bound fractions were analyzed by Na dodecyl SO4-polyacrylamide gel electrophoresis and fluorography. A subunit of Mr = 22,000 detected in the in vitro translation products of poly(A) RNAs from heart, kidney, lung, spleen, and testis is missing from the translation products of liver poly(A) RNAs. This Mr = 22,000 subunit is present only in the anionic glutathione S-transferase fraction purified from rat heart, kidney, lung, spleen, and testis. Purified anionic glutathione S-transferase from rat liver does not contain this subunit. The relative specific activities toward a dozen different substrates also demonstrate the nonidentity between liver and kidney anionic glutathione S-transferases. In addition, among the glutathione S-transferase subunits expressed in the liver, some of them could not be detected in the other tissues investigated. Our results indicate that tissue-specific expression of rat glutathione S-transferases may occur pretranslationally.

Animals↗
PubMed1982

Cloning and sequence analysis of a cDNA plasmid for one of the rat liver glutathione S-transferase subunits.

We describe the construction and characterization of a cDNA plasmid for one of the rat liver glutathione S-transferase subunits. Poly(A)-RNA isolated from rat livers was enriched for glutathione S-transferase mRNA activity and used as templates to synthesize double stranded cDNA. The double stranded cDNAs were annealed to pBR322 through terminal deoxynucleotidyl transferase generated GC-tails followed by transformation into E. coli. Several candidate clones were selected by colony hybridization using polynucleotide kinase labeled liver and testis poly(A)-RNA probes. These candidate clones were further characterized by hybrid-selected translation of mRNA followed by immunoprecipitation and SDS gel electrophoresis. The positive clone, pGTR112 was mapped with restriction endonuclease analysis and sequenced by the chemical method of Maxam and Gilbert. The largest upen reading frame contains 142 amino acids very rich in Arg and Lys residues. The C-terminal residue phenylalanine of this open reading frame is consistent with what was reported for one of the ligandin subunits by Bhargava et al., (J. Biol. Chem. 253, 4116-4119, 1978). Among the 352 nucleotides covered by both pGTR112 and pGST94 described by Kalinyak and Taylor (J. Biol. Chem. 257, 523-530, 1982), there are only 9 nucleotide differences resulting in four changes of amino acid sequences.

Amino Acid Sequence↗
PubMed1981

Structural patterns in the corpora pedunculata of orthoptera: a reduced silver analysis.

The calyx region and pedunculus of the corpora pedunculata ("mushroom bodies") were studied comparatively in reduced silver preparations of the brain from 16 species of Orthoptera representing four families (Acrididae, Gryllidae, Tettigoniidae, and Gryllacrididae). In the acridid grasshopper Melanoplus femurrubrum (de Geer), on which emphasis was placed, the concave primary calyx is bilayered and exhibits a special central zone. Globuli cell axons occur within both layers. The bulbous accessory calyx is unlayered and sends anterior extensions beneath the primary calyx. The main input tracts into primary and accessory calyx, respectively, are the tractus olfactorio-globularis and tritocerebral tract. The pedunculus consists of one barrel with three major fiber columns, of which two originate in the primary calyx and one in the accessory calyx. Its fibers display a coaxial arrangement, superimposed on the tripartite organization. Structural conditions in other acridids are similar. In the other families the calyx region similarly includes a bilayered primary calyx and unlayered accessory calyx. The latter, variable in form, is closely associated with the base of the primary calyx in tettigoniids and gryllacridids. The calyces receive the same major tracts as in acridids. The pedunculus is coaxially organized. These features are theorized to have originated as follows. In the progenitors of Orthoptera the corpora pedunculata included two mutually equivalent, bilayered calyces and a "double-barreled" pedunculus. The orthopteran primary calyx arose through coalescence of these calyces. Concomitantly, the two peduncular barrels fused into one. The accessory calyx originated at the base of the primary calyx, from the class of globuli cell axons of the latter's external layer. Probably this occurred in response to increased functional importance to tritocerebral input.

Animals↗
PubMed1980

Prostaglandins and congeners. 22. Synthesis of 11-substituted derivatives of 11-deoxyprostaglandins E1 and E2. Potential bronchodilators.

The interesting bronchodilator activity of l-11-deoxy-11 alpha-[(2-hydroxyethyl)thio]prostaglandin E2 methyl ester (3a) is described. The preparation of 3a and its analogues by Michael-type additions to various members of the PGA series or by total synthesis using the lithiocuprate conjugate addition process is also described. Structure-activity relationships in this series are discussed.

Airway Resistance↗
PubMed1978

Reduction of membrane potential, an immediate effect of colicin K.

Colicin K causes a rapid and drastic reduction of the membrane potential of Escherichia coli cells, as measured by the uptake of the lipophilic cation triphenylmethylphosphonium. The colicin causes no major changes in the pH gradient, as measured by the uptake of butyric acid. The decrease in membrane potential following addition of colicin K to the cells is a prompt response that parallels or precedes known physiological effects such as efflux of accumulated substrates. Hence the loss of membrane potential qualifies as the primary action by which the colicin uncouples membrane-associated function from respiration. Certain peculiarities of bacterial cells pretreated with EDTA in their response to uncoupling agents and lipophilic ions are described.

Biological Transport↗
PubMed1978

Evaluation of absorbable suture materials in biliary tract surgery.

A comparative study of absorbable suture materials in the presence of digestive fluids has been made. At day 7, plain and chromic catgut had lost 81% and 64% respectively of their initial tensile strengths in bile at a temperature of 37 degrees C, whereas Dexon and Vicryl preserved 82+ and 49% respectively of theirs. Plain and chromic catgut are completely dissolved in gastric juice within two days and had lost about 90% of their initial tensile strength in pancreatic juice on day 4. They produce significant tissue reaction. Dexon and Vicryl appear to be similar in their tissue reaction which is minimal. However, the former is stronger than the latter in the presence of bile. We believe the surgeon who undertakes any type of biliary tract surgery may wish to review his choice of absorbable suture material used in view of the information presented herein.

Absorption↗