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C C Cunningham

Publications and source records attributed to C C Cunningham.

At least 55 records · Page 3Linked to original sources
PubMed1993

Actin-binding protein contributes to cell volume regulatory ion channel activation in melanoma cells.

The cell volume regulatory response to a hypotonic stimulus is frequently initiated by activation of K+ and Cl- channels. We have characterized the hypotonic cell volume regulatory response of human melanoma cells devoid of actin-binding protein (ABP) and their genetically rescued counterpart transfected with the cDNA for ABP. ABP-deficient cells were unable to volume-regulate or activate K+ channels when exposed to a hypotonic stimulus. Genetic rescue with ABP resulted in recovery of both the cell volume regulatory response and the osmotically linked K+ channel activation. These data are consistent with a functional interaction between the actin cytoskeleton and osmotically sensitive ion transport.

Cell Size↗
PubMed1993

A human lymphocytotoxic autoantibody is encoded by antibody variable region genes in their germ line configuration.

Lymphocytotoxic autoantibodies are commonly found in sera from kidney dialysis patients, where they interfere with interpretation of the crossmatch test. We have produced a monoclonal lymphocytotoxic autoantibody by EBV transformation of PBLs from a dialysis patient, followed by fusion of the transformed cells with a heteromyeloma. The autoantibody derived, called FWE, was IgM kappa class and its pattern of reactivity against T and B lymphocytes, cells from patients with chronic lymphocytic leukemia and K562, was similar to that described for lymphocytotoxic autoantibodies found in sera. It was absorbed by fetal but not adult human erythrocytes, suggesting the antigenic determinant might be the blood group antigen i. cDNA encoding the variable domain of FWE was amplified by polymerase chain reaction, cloned into the vector M13 mp18, and sequenced. The variable region of the kappa light chain (V kappa) was 98.8% identical over a 260-bp stretch with a known germ line sequence and the junctional (J kappa) region was identical over 16 bp with the germ line sequence J kappa 2. The variable region of the heavy chain (VH) was 99.3% identical over a 268-bp overlap with the germ line gene VH4.21, a member of the VHIV family, and the junctional region of the heavy chain (JH) was identical with the germ line JH gene JH5 over 46 bp, with a truncated 5' end. The diversity region was not identified. These data suggest that the genes required to produce human lymphocytotoxic autoantibodies are encoded within the germ line and, therefore, that all dialysis patients may be able to produce them under certain circumstances.

Amino Acid Sequence↗
PubMed1992

Actin-binding protein requirement for cortical stability and efficient locomotion.

Three unrelated tumor cell lines derived from human malignant melanomas lack actin-binding protein (ABP), which cross-links actin filaments in vitro and connects these filaments to plasma membrane glycoproteins. The ABP-deficient cells have impaired locomotion and display circumferential blebbing of the plasma membrane. Expression of ABP in one of the lines after transfection restored translocational motility and reduced membrane blebbing. These findings establish that ABP functions to stabilize cortical actin in vivo and is required for efficient cell locomotion.

Actins↗
PubMed1992

Actin structural proteins in cell motility.

The machinery for cell locomotion is based in a network of polymerized actin filaments supporting the peripheral cytoplasm. This network or 'gel' consists of actin filaments in a variety of configurations, including cables, loose bundles, and branching arrays; all formed by the interaction of actin-associated proteins with actin filaments. For cell locomotion to occur, this network must be reversibly disassembled or 'solated' to allow protrusion, then re-assembled to stabilize the resulting extension. Thus, proteins to promote both 'solation' and 'gelation' of actin are important for efficient cell locomotion. Because of their distribution, control, and in vitro effects on actin filaments, two such proteins, gelsolin and actin-binding protein (ABP) should play especially important roles in cell motility. Support for this premise is found in in vivo studies of mouse kidney fibroblasts which demonstrated increased translocational locomotion after cytoplasmic gelsolin expression was increased genetically and in melanoma cells missing actin-binding protein which behave as expected for a cell unable to achieve efficient actin gelation. Since malignant transformation is known to affect the expression and distribution of several of these actin structural proteins, including gelsolin, further investigations of the role these proteins play in cell motility will be important to the determination of tumor cell motility and hence metastatic propensity.

Animals↗
PubMed1992

The use of the Ways of Coping (Revised) questionnaire with parents of children with Down's syndrome.

The principal aim of this study was to assess the validity and usefulness of the Ways of Coping (Revised) questionnaire (Folkman & Lazarus, 1985) with a British sample of parents of children with Down's syndrome. Factor analysis yielded five subscales which were compared with those reported elsewhere. Other properties of the instrument were investigated. It was concluded that the instrument was potentially valuable to those investigating coping in families with special problems.

Adaptation, Psychological↗
PubMed1991

Effect of chronic ethanol consumption on hepatic mitochondrial transcription and translation.

Liver mitochondria from ethanol-fed rats display an impaired ability for protein synthesis in vitro. Studies were conducted to explore the possible mechanisms which might account for this impaired capacity of ethanol mitochondria for protein synthesis. The present studies did not demonstrate any significant ethanol-induced lesion in mitochondrial nucleic acid metabolism in organelles isolated from ethanol-fed rats for any of the parameters investigated (mtDNA content, steady-state mtRNA concentration, mtRNA polymerase activity, concentration of specific mRNAs and rRNAs, mtRNA processing). An investigation of ribosome function in isolated mitochondria demonstrated significant decreases in the number of active ribosomes (55% fewer) in mitochondria from ethanol-fed rats. Initiation of protein synthesis was also significantly depressed (46%) in ethanol mitochondria. In addition, the yield of ribosomal particles from ethanol mitochondria was decreased 32% as compared to the yield of ribosomal particles from control mitochondria. However, isolated ribosomes from ethanol mitochondria were determined to be fully functional in a poly(U)-directed phenylalanine polymerization system. Soluble translation factors from ethanol mitochondria were also found to support full activity of control ribosomes in a poly(U)-directed phenylalanine polymerization system. These results suggest strongly that the ethanol-induced depression of mitochondrial protein synthesis is due to a decrease in the number of competent ribosomes in hepatic mitochondria from chronically ethanol-fed rats.

Animals↗
PubMed1991

Enhanced motility in NIH 3T3 fibroblasts that overexpress gelsolin.

Increasing the content of the actin-binding protein gelsolin in cultured mouse fibroblasts by up to 125 percent by gene transfection proportionally enhanced the rate at which the cells migrated through porous filters toward a gradient of serum and closed a wound made on a confluent monolayer of cells in a tissue culture dish. These results provide direct evidence that gelsolin, which promotes both actin assembly and disassembly in vitro, is an important element in fibroblast locomotion and demonstrate that the manipulation of intracellular machinery can increase cell motility.

Animals↗
PubMed1991

The interaction between chronic ethanol consumption and oxygen tension in influencing the energy state of rat liver.

Hepatocytes were isolated from chow-fed and liquid-diet control rats, and animals fed ethanol chronically for 31 days. These preparations were analyzed for adenine nucleotide and inorganic phosphate concentrations after being maintained under various conditions of oxygenation and nutrient availability. Hepatocytes from ethanol-fed animals resuspended at high cell density (oxygen tensions near zero) demonstrated a greater depression in cellular energy state as indicated by decreases in phosphorylation potential and energy charge. If, however, these hepatocytes were restored to high oxygen tension their energy state was equivalent to that observed with preparations from liquid-diet control animals. Moreover, their rate of oxygen consumption was equivalent to that of control hepatocytes. Analyses of livers from chow-fed, liquid diet control, and ethanol-fed rats which were freeze-clamped while being perfused by the animal's blood revealed that there were no significant differences in the energy states of the hepatic tissue from these three animal groups. These results indicate that (1) the hepatic energy state in rats fed ethanol chronically is maintained under conditions of normal oxygen tension and (2) that hepatic tissue from these animals experiences a much more dramatic depression in energy state than tissue from control rats when subjected to oxygen deprivation.

Adenosine Triphosphate↗
PubMed1990

Tightly associated cardiolipin in the bovine heart mitochondrial ATP synthase as analyzed by 31P nuclear magnetic resonance spectroscopy.

The bovine heart F0F1-ATPase preparation (Serrano, R., Kanner, B., and Racker, E. (1976) J. Biol. Chem. 251, 2453-2461) has been further delipidated. The lipid-deficient preparation contained 2.5 mol of cardiolipin, 1 mol of phosphatidylcholine (PC), and 1 mol of phosphatidylethanolamine (PE) per mol of F0F1. When reconstituted with asolectin the delipidated preparation exhibited an activity of 13 mumol of ATP hydrolyzed/min/mg of protein which was 88% oligomycin-sensitive. The phospholipids in this preparation were analyzed by 31P NMR spectroscopy to determine if they were immobilized by the enzyme (rendered NMR-invisible). The PC and PE were below the limits of detection under the conditions utilized and the cardiolipin was NMR-invisible until the enzyme was denatured by addition of either 1% sodium dodecyl sulfate or 8 M urea. Addition of cardiolipin to the delipidated preparation and subsequent analysis by NMR spectroscopy revealed that approximately 4 mol of cardiolipin were immobilized per mol of F0F1 ATPase. The enzyme appears to have high affinity for cardiolipin exclusively, since PC (a prominent inner membrane lipid), phosphatidyl serine (an acidic phospholipid), and phosphatidyl glycerol (the precursor to cardiolipin) were not immobilized (rendered NMR-invisible) when added to the delipidated preparation.

Adenosine Triphosphate↗
PubMed1990

Effects of chronic ethanol consumption on the synthesis of polypeptides encoded by the hepatic mitochondrial genome.

Liver mitochondria from rats fed ethanol chronically demonstrate an impaired ability to incorporate [35S]methionine into polypeptide products in vitro. This ethanol-induced effect on mitochondrial translation in vitro could not be attributed to significant differences in the methionine precursor pool sizes of ethanol and control mitochondria or to the acute effects of residual ethanol. The observed reduction of radiolabeled methionine incorporation into mitochondrial gene products of ethanol mitochondria in vitro reflects a decrease in the synthesis of all the mitochondrial gene products. However, the percentage of total radiolabel incorporated into each gene product is unaffected by ethanol, suggesting an ethanol-induced coordinate depression of mitochondrial protein synthesis. Moreover, SDS-PAGE and densitometry of submitochondrial particles from ethanol-fed and control rats demonstrated that the steady-state concentration of each of the mitochondrial gene products is decreased in ethanol-fed rats. This reduction of the steady-state concentration of the mitochondrial gene products may be related to the observed depressions of oxidative phosphorylation activities associated with hepatic mitochondria from ethanol-fed rats.

Alcoholism↗
PubMed1990

The effects of chronic ethanol consumption on hepatic mitochondrial energy metabolism.

Chronic ethanol consumption results in a generalized depression in hepatic mitochondrial energy metabolism. Both the rate and efficiency of ATP synthesis via the oxidative phosphorylation system are decreased. Alterations in the activities of several components of the oxidative phosphorylation system contribute to the overall decrease in the capacity for ATP synthesis. There appears to be no alteration in any particular component which is rate-limiting. Although changes in membrane lipids may play a minor role, it appears that the decreased levels of mitochondria-derived polypeptide components of the oxidative phosphorylation system are primarily responsible for the depression in both the rate and efficiency of ATP synthesis. The concentrations of these mitochondrial gene products are lowered due to effects of chronic ethanol consumption on the mitochondrial translational process.

Animals↗
PubMed1989

Apparent response of refractory post-transfusion purpura to splenectomy.

Post transfusion purpura (PTP) is a rare disorder characterized by the abrupt onset of severe thrombocytopenia following transfusion. A patient with PTP and massive bleeding was refractory to corticosteroids, gamma globulin, and plasma exchange but developed an immediate and sustained rise in platelet count following splenectomy. Splenectomy may be a useful therapeutic modality in patients with refractory PTP.

Aged↗
PubMed1989

Comparison of effects of long-term ethanol consumption on the heart and liver of the rat.

Alterations in heart and liver metabolism were determined periodically in Sprague-Dawley rats pair-fed a liquid diet (ethanol, 36% of calories) for times as long as 1 year. In liver mitochondria the rate of ATP synthesis was lowered significantly after ethanol administration for 1 month and longer feeding periods. In liver microsomes from ethanol-fed animals, ethanol oxidation and aniline hydroxylation increased 1.5- and 3.5-fold, respectively, after 1 month and remained elevated at the longer feeding intervals. Electron microscopic analyses of heart left ventricles revealed no alterations from ethanol consumption for 1 month. Alterations including disrupted mitochondrial cristae, dilatation of sarcoplasmic reticulum, and widening of the intercalated discs were observed after 6.5-month feeding periods. Myocardial concentrations of creatine, creatine phosphate, ATP, ADP, and Pi remained constant even after ethanol consumption for 9 months. After a 12-month feeding period slight changes in cardiac mitochondrial energy-linked properties were observed which were not as pronounced as those occurring in liver mitochondria. The activity and oligomycin sensitivity of the ATPase were not altered in cardiac mitochondria, whereas in liver preparations significant alterations in these properties of the ATPase were apparent after ethanol consumption for 1 month and the longer feeding periods. These observations suggest that the liver responds more quickly and dramatically to chronic ethanol consumption than does the heart.

ATP Synthetase Complexes↗
PubMed1987

Control of state 3 respiration in liver mitochondria from rats subjected to chronic ethanol consumption.

Male Sprague-Dawley rats were pair-fed a liquid diet containing 36% of calories as ethanol for at least 31 days. Mitochondria were isolated from the livers and assayed for state 3, state 4 and uncoupled respiration at all three coupling sites. Assay conditions were established that maximized state 3 respiration with each substrate while maintaining a high respiratory control ratio. In mitochondria from ethanol-fed animals, state 3 respiratory rates were decreased at all three coupling sites. The decreased state 3 rate observed at site III was still significantly higher than the state 3 rates observed at site II in mitochondria from either ethanol-fed or control animals. Moreover, the maximal (FCCP-uncoupled) rates with succinate and alpha-ketoglutarate were the same in mitochondria from ethanol-fed and control animals, whereas with glutamate-malate as substrate it was lowered 23% by chronic ethanol consumption. To investigate the role of cytochrome oxidase in modulating the respiratory rate with site I and site II substrates, the effects of cyanide on state 3 and FCCP-uncoupled respiration were determined. When the mitochondria were uncoupled there was no decrease in the rate of succinate oxidation until the rates of ascorbate and succinate oxidation became equivalent. Conversely, parallel inhibition of ascorbate, succinate and glutamate-malate state 3 respiratory rates were observed at all concentrations (1-50 microM) of cyanide utilized. These observations suggest strongly that in coupled mitochondria ethanol-elicited decreases in cytochrome oxidase activity depress the state 3 respiratory rates with site I and II substrates.

Adenosine Triphosphate↗
PubMed1987

Ethanol-elicited alterations in the oligomycin sensitivity and structural stability of the mitochondrial F0 . F1 ATPase.

Liver mitochondria from rats fed ethanol chronically demonstrated a 35% decrease in mitochondrial ATPase activity. Moreover, the ATPase activity was inhibited only 61% by addition of oligomycin. Treatment of mitochondria from ethanol-fed rats with the detergent, Lubrol-WX, caused the release of 36% of the F1 from the resulting inner membrane particles. In comparison, only 5% of the F1 was dissociated when control mitochondria were subjected to the Lubrol treatment. However, when the units of ATPase activity from the supernatant and particles obtained after Lubrol treatment were added together, their sums were equivalent in preparations from control and ethanol-fed animals. Moreover, polyacrylamide gel electrophoresis analyses indicated equal amounts of the alpha + beta subunits of F1 in mitochondria from control and ethanol-fed rats. Reconstitution experiments with urea particles and F1 prepared from both control and ethanol mitochondria revealed a decrease in oligomycin sensitivity which could be attributed to an alteration in the functioning of either the oligomycin sensitivity conferring protein or a membrane sector subunit that interacts with oligomycin. Analysis by reconstitution also demonstrated that there were no ethanol-elicited alterations in the properties of the F1 portion of the ATP synthase complex. These observations indicate that the activity of the ATP synthase complex is altered significantly by ethanol-elicited changes in the functioning of those polypeptides involved in modulating both oligomycin sensitivity and the association of F1 with membrane sector subunits.

Animals↗
PubMed1987

The application of temperament questionnaires to a British sample: issues of reliability and validity.

One hundred and five mothers of British children aged 1-5 years completed the EASI-1 Temperament Survey and the age appropriate version of the Carey questionnaire (Toddler Temperament Scale or Behavioural Style Questionnaire). Detailed statistical analyses revealed psychometric weakness in all three instruments, most notably in the Carey questionnaires. Neither factor analysis nor item-to-scale correlations provided clear support for the nine NYLS dimensions incorporated within the TTS and BSQ. Mothers' opinions of their child's temperament constellation differed considerably from those resulting from the questionnaire analysis for the STWU and Difficult constellations. Issues of reliability and validity are discussed.

Child, Preschool↗
PubMed1987

The effect of chronic ethanol consumption on the lipids in liver mitochondria.

The ethanol-related alterations in hepatic mitochondrial phospholipids are primarily changes in acyl chain composition. There are no alterations in the unesterified cholesterol content in the mitochondrion, as measured by the cholesterol-phospholipid ratio. Moreover, the distribution of mitochondrial phospholipids are not changed as a result of chronic ethanol consumption. There was a significant ethanol-related decrease (18%) in the phospholipid-protein ratio in mitochondria from rats maintained on a low-fat diet, which was not observed in studies where animals were fed diets containing a higher proportion of lipid. This effect of dietary composition on the phospholipid-protein ratio was also paralleled by the interaction between diet and ethanol in influencing the phospholipid acyl composition. The alterations in acyl chain distribution indicated that ethanol consumption stimulated elongation of palmitic acid, and depressed the delta 5 desaturation step required for the formation of arachidonic acid. Elongation of palmitic acid was stimulated in studies where animals were fed diets with moderate amounts of fat, whereas depressed synthesis of arachidonate occurred more frequently, but not exclusively, in studies where low-fat diets were employed. These results indicate that there is a significant interaction between diet and ethanol in eliciting changes in hepatic mitochondrial phospholipids. The significant decrease in the linoleic acid content of cardiolipin and the more prominent ethanol-associated alterations in mitochondrial phospholipids suggest that ethanol consumption depresses the phospholipid reacylation activities associated with the mitochondrion. The above observations indicate, therefore, that the alterations occurring in mitochondrial phospholipids are influenced by ethanol-related changes in mitochondrial enzymes involved in phospholipid metabolism. In addition, alterations in the availability of fatty acids due to ethanol-related changes in microsomal elongation and desaturation activities also appear to affect the fatty acid composition of phospholipids in mitochondria from ethanol-fed animals.

Alcoholism↗