Acetaldehyde and lactate stimulate collagen synthesis of cultured baboon liver myofibroblasts

Cells with electron-microscopic characteristics of myofibroblasts were isolated from baboon liver biopsy specimens by collagenase digestion and Percoll density gradient centrifugation and then cultured. The cultures consisted of only one cell type. By immunofluorescence, these cells synthesized collagen types I, III, and IV and laminin. Typical features of myofibroblasts were maintained throughout many passages in the culture. To study the effects of ethanol (and its oxidation product acetaldehyde and associated metabolite lactate) on myofibroblast collagen synthesis, the cell cultures were incubated for 24 h in a medium containing either 50 mM ethanol, 200 microM acetaldehyde, or 5 mM lactate. The cells did not contain significant alcohol dehydrogenase activity. Acetaldehyde stimulated significantly (p less than 0.05) myofibroblast collagen synthesis without changing noncollagen protein synthesis or proline pools. Lactate caused a significant (p less than 0.02) increase in intracellular proline pool and collagen synthesis. Ethanol itself did not have any effect on collagen synthesis of myofibroblasts. The stimulation of collagen synthesis of hepatic myofibroblasts by acetaldehyde and lactate may contribute to the development of alcoholic liver fibrosis, as alcohol intake is known to elevate acetaldehyde and lactate in tissues and blood.     

Increase of microsomal glucose-6-phosphatase activity after chronic ethanol administration

To study the effect of chronic ethanol administration on the activity of hepatic microsomal glucose-6-phosphatase, female rats were pair-fed liquid diets with 36% of total calories either as ethanol or isocaloric carbohydrate (controls). The remainder of the diet contained 35% of total calories as fat, 18% as protein, and 11% as additional carbohydrate. Six weeks of ethanol feeding as isocaloric substitution for carbohydrate increased significantly the activity of glucose-6-phosphatase (expressed per mg microsomal protein) both in fed (38%; p < 0.001) and fasted 18%; p < 0.02) rats. When expressed per unit of body weight, the enzyme activity was increased even further both in fed (66%; p < 0.01) and fasted (43%; p < 0.01) rats. Another group of rats received diets containing 36% of calories either as ethanol or isocaloric fat. The remainder of the diet contained 11% of total calories as carbohydrate, 18% as protein, and 35% as additional fat. Six weeks of this ethanol feeding as isocaloric substitution for fat again increased glucose-6-phosphatase activity significantly. Ultracentrifugation in a Cs⁺-containing sucrose gradient to separate rough and smooth microsomes revealed that the increase in glucose-6-phosphatase activity after ethanol feeding occurred mainly in the smooth microsomal membranes.     

Human Gastric Alcohol Dehydrogenase: Its Inhibition by H2-Receptor Antagonists, and Its Effect on the Bioavailability of Ethanol

Two types of alcohol dehydrogenase isoenzymes (differing in their affinity for ethanol, sensitivity to 4-methylpyrazole, and electrophoretic migration) have been identified in the human stomach. At the high ethanol concentrations prevailing in the gastric lumen during alcohol consumption, the sum of their activities could account for significant oxidation of ethanol. In vitro, these activities were inhibited by cimetidine and ranitidine, but not by famotidine. In vivo, therapeutic doses of cimetidine (but not of famotidine) increased blood ethanol levels when ethanol was given orally, but not when it was given intravenously, indicating a significant contribution of the gastric ADH to the bioavailability and thereby the potential toxicity of ethanol.     

S-adenosyl-L-methionine attenuates alcohol-induced liver injury in the baboon

Chronic ethanol consumption by baboons (50% of energy from a liquid diet) for 18 to 36 mo resulted in significant depletion of hepatic S-adenosyl-L-methionine concentration: 74.6 +/- 2.4 nmol/gm vs. 108.9 +/- 8.2 nmol/gm liver in controls (p less than 0.005). The depletion was corrected with S-adenosyl-L-methionine (0.4 mg/kcal) administration (102.1 +/- 15.4 nmol/gm after S-adenosyl-L-methionine-ethanol, with 121.4 +/- 11.9 nmol/gm in controls). Ethanol also induced a depletion of glutathione (2.63 +/- 0.13 mumol/gm after ethanol vs. 4.87 +/- 0.36 mumol/gm in controls) that was attenuated by S-adenosyl-L-methionine (3.89 +/- 0.51 mumol/gm in S-adenosyl-L-methionine-methanol vs. 5.22 +/- 0.53 mumol/gm in S-adenosyl-L-methionine controls). There was a significant correlation between hepatic S-adenosyl-L-methionine and glutathione level (r = 0.497; p less than 0.01). After the baboons received ethanol, we observed the expected increase in circulating levels of the mitochondrial enzyme glutamic dehydrogenase: 95.1 +/- 21.4 IU/L vs. 13.4 +/- 1.8 IU/L; p less than 0.001, whereas in a corresponding group of animals given S-adenosyl-L-methionine with ethanol, the values were only 30.3 +/- 7.1 IU/L (vs. 9.6 +/- 0.7 IU/L in the S-adenosyl-L-methionine controls). This attenuation by S-adenosyl-L-methionine of the ethanol-induced increase in plasma glutamic dehydrogenase (p less than 0.005) was associated with a decrease in the number of giant mitochondria (assessed in percutaneous liver biopsy specimens), with a corresponding change in the activity of succinate dehydrogenase, a mitochondrial marker enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)     

Attenuation of alcohol-induced hepatic fibrosis by polyunsaturated lecithin

Characteristic features of alcoholic liver injury include fibrosis and striking membrane alterations, with associated phospholipid changes. To offset some of these abnormalities, a 10-yr study was conducted in baboons: 12 animals (eight females, four males) were fed a liquid diet supplemented with polyunsaturated lecithin (4.1 mg/kcal) for up to 8 yr, with either ethanol (50% of total energy) or isocaloric carbohydrate. They were compared with another group of 18 baboons fed an equivalent amount of the same diet (with or without ethanol), but devoid of lecithin. In the two groups, comparable increases in lipids developed in the ethanol-fed animals, but striking differences in the degree of fibrosis were seen. Whereas at least septal fibrosis (with cirrhosis in two) and transformation of their lipocytes into transitional cells developed in seven of the nine baboons fed the regular diet with ethanol, septal fibrosis did not develop in any animals fed lecithin (p less than 0.005). They did not progress beyond the stage of perivenular fibrosis (sometimes associated with pericellular and perisinusoidal fibrosis) and had a significantly lesser activation of lipocytes to transitional cells. Furthermore, when three of these animals were taken off lecithin, but continued on the same amount of the ethanol-containing diet, they rapidly (within 18 to 21 mo) progressed to cirrhosis, accompanied by an increased transformation of their lipocytes to transitional cells. These results indicate that some component of lecithin exerts a protective action against the fibrogenic effects of ethanol. Because we had previously found that choline, in amounts present in lecithin, has no comparable action, the polyunsaturated phospholipids themselves might be responsible for the protective effect.     

Immunohistochemical localization of ethanol-inducible P450IIE1 in the rat alimentary tract

To determine whether P450IIE1, a microsomal P450 enzyme inducible by ethanol in the liver, is also present and inducible in the alimentary tract, corresponding frozen tissue sections were prepared from rats pair-fed liquid diets containing 36% of total calories as either ethanol or carbohydrate (control) for 3 weeks. Immunohistochemical staining was performed using the peroxidase-antiperoxidase method after tissue sections were reacted with antibody against human P450IIE1. In control animals, immunoreactive P450IIE1 was detected only in duodenal and jejunal villous cells. After ethanol treatment, the content of P450IIE1 increased in duodenal and jejunal villi, and the enzyme was now also found in squamous epithelial cells of the cheek mucosa, tongue, esophagus, and forestomach, and in surface epithelium of the proximal colon. P450IIE1 was neither expressed nor induced by alcohol in the epithelium of stomach fundic and antral mucosa, ileum, distal colon, and rectum. When considered together with the xenobiotic activation properties of P450IIE1, these results may partly explain why alcohol abuse is a risk factor for cellular damage or cancer or both in those alimentary tract tissues in which P450IIE1 is inducible by chronic ethanol intake.     

High blood alcohol levels in women. The role of decreased gastric alcohol dehydrogenase activity and first-pass metabolism

After consuming comparable amounts of ethanol, women have higher blood ethanol concentrations than men, even with allowance for differences in size, and are more susceptible to alcoholic liver disease. Recently, we documented significant "first-pass metabolism" of ethanol due to its oxidation by gastric tissue. We report a study of the possible contribution of this metabolism to the sex-related difference in blood alcohol concentrations in 20 men and 23 women. Six in each group were alcoholics. The first-pass metabolism was determined on the basis of the difference in areas under the curves of blood alcohol concentrations after intravenous and oral administration of ethanol (0.3 g per kilogram of body weight). Alcohol dehydrogenase activity was also measured in endoscopic gastric biopsies. In nonalcoholic subjects, the first-pass metabolism and gastric alcohol dehydrogenase activity of the women were 23 and 59 percent, respectively, of those in the men, and there was a significant correlation (rs = 0.659) between first-pass metabolism and gastric mucosal alcohol dehydrogenase activity. In the alcoholic men, the first-pass metabolism and gastric alcohol dehydrogenase activity were about half those in the nonalcoholic men; in the alcoholic women, the gastric mucosal alcohol dehydrogenase activity was even lower than in the alcoholic men, and first-pass metabolism was virtually abolished. We conclude that the increased bioavailability of ethanol resulting from decreased gastric oxidation of ethanol may contribute to the enhanced vulnerability of women to acute and chronic complications of alcoholism.     

Clinical characteristics and outcomes in polyarticular septic arthritis

Objectives

Septic polyarthritis is rarer than septic monoarthritis, but associated with higher mortality. Septic polyarthritis may be difficult to distinguish clinically from noninfectious inflammatory arthritis. We describe one of the largest samples of septic polyarthritis with the aim of distinguishing septic monoarthritis from polyarthritis.

Flexible electrical recording from cells using nanowire transistor arrays

Semiconductor nanowires (NWs) have unique electronic properties and sizes comparable with biological structures involved in cellular communication, thus making them promising nanostructures for establishing active interfaces with biological systems. We report a flexible approach to interface NW field-effect transistors (NWFETs) with cells and demonstrate this for silicon NWFET arrays coupled to embryonic chicken cardiomyocytes. Cardiomyocyte cells were cultured on thin, optically transparent polydimethylsiloxane (PDMS) sheets and then brought into contact with Si-NWFET arrays fabricated on standard substrates. NWFET conductance signals recorded from cardiomyocytes exhibited excellent signal-to-noise ratios with values routinely >5 and signal amplitudes that were tuned by varying device sensitivity through changes in water gate–voltage potential, V_g. Signals recorded from cardiomyocytes for V_g from −0.5 to +0.1 V exhibited amplitude variations from 31 to 7 nS whereas the calibrated voltage remained constant, indicating a robust NWFET/cell interface. In addition, signals recorded as a function of increasing/decreasing displacement of the PDMS/cell support to the device chip showed a reversible >2× increase in signal amplitude (calibrated voltage) from 31 nS (1.0 mV) to 72 nS (2.3 mV). Studies with the displacement close to but below the point of cell disruption yielded calibrated signal amplitudes as large as 10.5 ± 0.2 mV. Last, multiplexed recording of signals from NWFET arrays interfaced to cardiomyocyte monolayers enabled temporal shifts and signal propagation to be determined with good spatial and temporal resolution. Our modular approach simplifies the process of interfacing cardiomyocytes and other cells to high-performance Si-NWFETs, thus increasing the experimental versatility of NWFET arrays and enabling device registration at the subcellular level.     

Flow cytometric analysis of deoxyribonucleic acid ploidy in benign and malignant aldosterone-producing neoplasms of the adrenal gland

Studies of nuclear deoxyribonucleic acid (DNA) ploidy were performed to determine if ploidy was a marker of a malignant disease or a predictor of prognosis. Paraffin-embedded specimens from 20 benign and six malignant aldosterone-producing neoplasms were examined by flow cytometry. For 17 of the benign aldosteronomas, the DNA histograms were similar to those for samples of normal adrenal cortical parenchyma of adult humans. The three DNA histograms from benign (histologically and clinically) aldosteronomas and all six malignant aldosterone-producing neoplasms were abnormal. Tissue from the adrenal gland from three of the patients with malignant aldosterone-producing tumors exhibited a DNA tetraploid and polyploid pattern; adrenal tissue from three other patients with malignant tumors were classified as having DNA aneuploid histogram patterns. Only patients with DNA aneuploid histogram patterns subsequently died of the disease. Flow cytometry may have an important role prognostically, rather than diagnostically, in the evaluation of aldosterone-producing malignant neoplasms, because the DNA histograms from three benign adenomas were abnormal.