Histological distribution of class III alcohol dehydrogenase in human brain.

The distributions of class III alcohol dehydrogenase (ADH), a glutathione-dependent formaldehyde dehydrogenase, and class I ADH in the human brain were examined immunohistochemically. The most intense immunostaining of class III ADH was observed in the dendrites and cytoplasm of cerebellar Purkinje cells. Scattered cerebral cortical neurons in layers IV and V, and some hippocampal pyramidal neurons were also immunopositive. The neuronal distribution of class III ADH resembled that of the vulnerable neurons in patients with hypoxic encephalopathy, which in view of the intense staining in the Purkinje cells, raises the possibility that this enzyme contributes to the hypoxia and cerebellar degeneration suffered by chronic alcoholics. Perivascular and subependymal astrocytes, which contribute to the maintenance of the cerebral cellular milieu and isolate the brain from the systemic circulation and cerebrospinal fluid, were also class III ADH positive. As the substrates of this enzyme include intrinsic toxic formaldehyde, inflammatory intermediate of 20-hydroxy-leukoteiene B4, and possibly ethanol, the distribution of class III ADH immunostaining indicates this enzyme contributes to the defence of the brain against degenerative processes. The finding that, unlike ependymal cells, subependymal astrocytes were class III ADH positive, suggests this enzyme may be useful for differentiating astrocytes and ependymal cells.

Flow cytometric and fluorescence microscopic analysis of ethanol-induced G2+M block: ethanol dose-dependently delays the progression of the M phase.

We found previously that short-term (3 and 6 h) exposure to ethanol (100 and 200 mM) induced the transient arrest of L929 cells at the G2+M phase. To identify the exact site blocked during the G2+M phase, we carried out flow cytometry and microscopic analysis with asynchronous L929 cells exposed to ethanol (12.5-330 mM) for 3, 6 or 24 h. Flow cytometry (the simultaneous analysis of cellular DNA and cyclin B1 content) revealed that the percentage of 4c (tetraploid) cells with a high level of cyclin B1 increased after continuous 6 h exposure to ethanol (> or =82.5 mM) and decreased after 24 h exposure, which supports the idea of a transient M-phase block. To determine the sub-M phase of 4c cells with high levels of cyclin B1 based on spindle microtubules and their karyotype, we viewed immunofluorescent images by double staining with Hoechst 33258 (bis-benzimide trihydrochloride) for DNA and with fluorescein isothiocyanate-labelled antibody for cyclin B1 or beta-tubulin. A 6 h exposure to intermediate concentrations (50-100 mM) of ethanol increased the number of early-anaphase cells, compared with the control, suggesting an inhibition of the elongation of polar microtubules. Both 6 and 24 h exposure to higher concentrations (100-200 mM) of ethanol increased metaphase cells, indicating an arrest at the spindle assembly checkpoint and suggesting an inhibition of the shortening of kinetochore microtubules and/or the degradation of cyclin B . Moreover, 6 h exposure to 330 mM ethanol increased round, probably early-prophase, cells, suggesting inhibition of the formation of spindle microtubules. Thus, it is likely that higher concentrations of ethanol affect the elongation, contraction, and formation of the spindle microtubules of L929 cells dose-dependently and also disrupt the correlation between microtubule organization and the synthesis and degradation of cyclin B1, thereby delaying the progress of karyokinesis, which may lead to an ethanol-induced G2+M block.

Ethanol induces transient arrest of cell division (G2 + M block) followed by G0/G1 block: dose effects of short- and longer-term ethanol exposure on cell cycle and cell functions.

To study the cytophysiological effects of ethanol systematically, L929 cells, a fibroblastic cell line derived from mouse connective tissue, were exposed to various concentrations of ethanol (12.5, 50, 100 and 200 mM) for short (3 and 6 h) and longer (24 or 26 h) durations. Ethanol-induced cellular responses were analysed by a combination of the following assays: number of cells, amounts of DNA and protein, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and cell cycle. Ethanol dose-dependently suppressed these cellular functions, except that 12.5 mM exposures for both 6 and 26 h increased the amount of protein in spite of almost no change in other cellular functions, compared to the control. The most marked dose-dependency was observed in a reduction of formazan product in an MTT assay after both 6 and 26 h exposures to ethanol, being independent of the number of cells and probably reflecting dose-dependent depression of mitochondrial respiration. A G2 + M block in the cell cycle, an inhibition of cell division, was induced after short-term exposures (3 and 6 h) to 100 and 200 mM ethanol, but the block was released before 24 h had passed. Alternatively, prolonged exposures (24 h) to 50-200 mM ethanol induced a G0/G1 block, resulting in a decrease in the amount of DNA below the control value. Moreover, the percentage of the S phase was decreased gradually and dose-dependently throughout the 24 h exposure. Thus, high concentrations of ethanol (50, 100 and 200 mM) perturbed the cell cycle progression by causing both a transient G2 + M block (an inhibition of mitosis) and a continuous G0/G1 block, though the latter was masked by the G2 + M block during short-term exposure. The cells seem finally to acquire some tolerance to ethanol so as to pass through mitosis, but much less tolerance to pass through the checkpoint from the G1 to the S phase, which results in a decline in proliferation.

Alcohol dehydrogenase (ADH) isozymes in the AdhN/AdhN strain of Peromyscus maniculatus (ADH-deermouse) and a possible role of class III ADH in alcohol metabolism.

Although the AdhN/AdhN strain of Peromyscus maniculatus (so-called ADH- deermouse) has been previously considered to be deficient in ADH, we found ADH isozymes of Classes II and III but not Class I in the liver of this strain. On the other hand, the AdhF/AdhF strain (so-called ADH+ deermouse), which has liver ADH activity, had Class I and III but not Class II ADH in the liver. In the stomach, Class III and IV ADHs were detected in both deermouse strains, as well as in the ddY mouse, which has the normal mammalian ADH system with four classes of ADH. These ADH isozymes were identified as electrophoretic phenotypes on the basis of their substrate specificity, pyrazole sensitivity, and immunoreactivity. Liver ADH activity of the ADH- strain was barely detectable in a conventional ADH assay using 15 mM ethanol as substrate; however, it increased markedly with high concentrations of ethanol (up to 3 M) or hexenol (7 mM). Furthermore, in a hydrophobic reaction medium containing 1.0 M t-butanol, liver ADH activity of this strain at low concentrations of ethanol (< 100 mM) greatly increased (about sevenfold), to more than 50% that of ADH+ deermouse. These results were attributable to the presence of Class III ADH and the absence of Class I ADH in the liver of ADH- deermouse. It was also found that even the ADH+ strain has low liver ADH activity (< 40% that of the ddY mouse) with 15 mM ethanol as substrate, probably due to low activity in Class I ADH. Consequently, liver ADH activity of this strain was lower than its stomach ADH activity, in contrast with the ddY mouse, whose ADH activity was much higher in the liver than in the stomach, as well as other mammals. Thus, the ADH systems in both ADH- and ADH+ deermouse were different not only from each other but also from that in the ddY mouse; the ADH- strain was deficient in only Class I ADH, and the ADH+ strain was deficient in Class II ADH and down-regulated in Class I ADH activity. Therefore, Class III ADH, which was found in both strains and activated allosterically, may participate in alcohol metabolism in deermouse, especially in the ADH- strain.

[Mirroring on palmar interdigital configurational areas].

The palmar prints of 902 medical students (732 male and 170 female) were analyzed according to the method of Cummins and Midlo, in an attempt to reveal a bilateral variance of palmar interdigital configurations within individuals. 1) No sex differences were observed in the frequency of true patterns in each interdigital area. The overall frequency of true patterns was highest in the fourth interdigital area (left 86.7%, right 70.8%) and decreased in the following order: the hypothenar area (left 25.6%, right 22.8%), the third interdigital area (left 12.1%, right 29.7%), the thenar/first interdigital area (left 14.6%, right 4.3%) and the second interdigital area (left 0.6%, right 1.2%). 2) Each palmar configurational area showed a different frequency of true patterns in the right and left hands. In the hypothenar area, the thenar/first interdigital area and the fourth interdigital area, true patterns were found most frequently on the left hand. On the other hand, true patterns were found most frequently on the right hand in the second interdigital area and the third interdigital area, especially the frequency of the loop pattern, which was 2.8 times higher in the left palm than in the right palm in males, and 2.5 times higher in females. 3) The frequency of students who had the same pattern type in both hands was highest in the second interdigital area (98.4%) and decreased in the following order: the thenar/first interdigital area (88.0%), the hypothenar area (77.9%), the third interdigital area (74.1%) and the fourth interdigital area (68.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Lineage-specific and differentiation-dependent expression of K12 keratin in rabbit corneal/limbal epithelial cells: cDNA cloning and northern blot analysis.

Corneal epithelial cells synthesize an acidic (55 kDa) K12 and a basic (64 kDa) K3 keratin as their major differentiation products during an advanced stage of differentiation. In this paper, we describe the cDNA cloning of rabbit K12 keratin. We used a 36 base pairs (bp) oligonucleotide corresponding to a consensus sequence of many known acidic keratins as a probe to screen a cDNA library of normal rabbit corneal epithelium. Several partial cDNA clones were isolated. Hybrid-selection showed that the 3'keratin chain-specific portion of the cDNA hybridizes with K12 mRNA. A rabbit antiserum raised against the C-terminus of the cDNA-deduced amino acid sequence recognizes, in immunoblotting, the K12 keratin. In situ hybridization showed that K12 mRNA is present in all cell layers of central corneal epithelium, but in only the suprabasal cells of limbal epithelium indicating a parallel expression pattern between K12 and K3. Cultured rabbit corneal epithelial cells initially synthesize K14/K5 keratins, but later when the cells become heavily stratified they synthesize large quantities of K12 and K3 mRNAs, as detected by Northern blotting. Cultured esophageal epithelial cells do not make K12 mRNA confirming the tissue-specificity of K12 expression. Although it has been suggested that conjunctival epithelial cells can trans-differentiate into a bona fide corneal epithelium, we showed here that cultured conjunctival cells do not synthesize significant amounts of K12/K3 mRNAs. These results strongly suggest that conjunctival epithelial cells, whose differentiation can be modulated significantly by the extracellular matrix, form a lineage intrinsically distinct from the corneal/limbal epithelial lineage.

Expression of collagen I, smooth muscle alpha-actin, and vimentin during the healing of alkali-burned and lacerated corneas.

PURPOSES: Alkali-burned corneas can seldom heal properly to restore corneal transparency. To provide a better understanding of this devastating corneal injury, we compared the expression of collagen I, smooth muscle alpha-actin (alpha-SMA), and vimentin in lacerated and alkali-burned rabbit corneas. METHODS: A radiolabeled cDNA probe of alpha 1(I) chain was used in slot-blot hybridization to determine the levels of alpha 1(I) mRNA in alkali-burned corneas. In situ hybridization was used to identify the cell types that express the alpha 1(I) chain. Antibodies against collagen I, alpha-SMA, and vimentin were used in immunohistochemical studies to determine the tissue distribution of collagen I and to identify cells expressing alpha-SMA and vimentin. RESULTS: The levels of alpha 1(I) mRNA in alkali-burned corneas increased steadily after the alkali burn and reached a plateau within 2 weeks. One day after alkali burn, specific in situ hybridization signals were detected in stromal cells immediately surrounding the edge of the corneal injury. As the healing proceeded, the fibroblastic cells migrated into the injured stroma, and they showed positive reactions by in situ hybridization and by immunostaining with anti-collagen I probes. In alkali-burned corneas, retrocorneal membranes were formed 1 week after injury. This fibrillar membrane was stained by anti-collagen I antibody, and the fibroblastic cells in the membrane were hybridized by the 3H-labeled alpha 1(I) cDNA probe. No retrocorneal membrane was formed in the lacerated corneas, even after the injured corneas were allowed to heal for 3 weeks. The epithelial cells in the epithelial plug of lacerated corneas were positive by in situ hybridization, whereas the epithelial cells in the regenerated epithelium of alkali-burned cornea was not. Antibodies against alpha-SMA reacted with the migrating fibroblastic cells but did not react with epithelial cells or endothelial cells in the injured corneas. Anti-vimentin antibody reacted with fibroblastic cells, endothelial cells, and keratocytes in normal and injured corneas, and with the basal epithelial cells of injured corneas. CONCLUSIONS: During wound healing, the keratocytes that migrate to injured stroma transform into myofibroblasts. These myofibroblasts express high levels of alpha 1(I) mRNA, alpha-SMA, and vimentin. The healing of alkali-burned corneas differ from that of lacerated corneas in that the retrocorneal membranes are formed in the former but not in the latter. In addition, the epithelial cells of alkali-burned corneas lack alpha 1(I) mRNA, whereas it is found in the epithelium of lacerated corneas. These differences may result from the persistence of inflammatory cells in the alkali-burned corneas.

Diminution of biological reactivity of ethanol by changing the solution structure by weak ultrasonication.

The weak ultrasonication (40 kHz, 12 mW, 1 week) of ethanol solutions was found to reduce stimulation of the senses of smell and taste by the ethanol on the basis of blind tests with an aqueous ethanol solution (33.0% w/v) and an immature distilled spirit (25.0% v/v). Experiments on mice also demonstrated that a treated aqueous ethanol solution had a weaker depressant effect on the central nervous system, as evaluated by the relative frequency with which mice regained the righting reflex at a dose of either 4.0 or 4.5 g/kg (p < 0.05 or p < 0.01, respectively) and by the reduction in rectal temperature at a dose of 5.0 g/kg (p < 0.05) soon after ethanol administration. Analyses of both the ethanol concentration by head-space gas chromatography and the free radicals by electron spin resonance spectrometer failed to reveal any chemical changes in aqueous ethanol solutions subjected to weak ultrasonication. However, measurement of the spin-lattice relaxation time (T1) of the 2H of water molecules by 2H-NMR showed that the treatment slightly accelerated the thermal motion of water molecules in the solutions. Treated solutions were also found to have a slightly higher density than untreated ones. These physical data demonstrate that weak ultrasonication induces a structural change, such as a more compact and homogeneous structure by changing the microdynamic behavior of the solution. These biological and physical studies suggest that only a slight structural change in an ethanol solution induces a marked change in the biological reactivity of ethanol without any chemical modification of the solution itself.

Expression of K12 keratin in alkali-burned rabbit corneas.

The healing of alkali-injured corneas is characterized by the persistence of polymorphonuclear leukocytes (PMN) in tissues and recurrent corneal epithelial defects. It has been suggested that the proteolytic enzymes secreted by PMN may account in part for the recurrent epithelial defects in the alkali-burned corneas. Cytoplasmic keratins, which form intracellular intermediate filaments, participate in the formation of hemidesmosomes and play a key role in the focal adhesion of epithelial cells to the basement membranes. The K3/K12 keratin pair is a major constituent of differentiated and stratified corneal epithelium. We have recently cloned the cDNA encoding the rabbit K12 keratin. In the present study we examined the expression of K12 keratin during the healing of alkali-burned rabbit corneas by slot-blot and in situ hybridization. Our results indicate that in normal cornea K12 keratin is equally expressed in all cell layers of stratified corneal epithelium and suprabasal layers of limbal epithelium, but not in bulbar conjunctival and other epithelia, i.e., lens, iris, and retinal pigment epithelium. The basal cells of the detached regenerating epithelium of the injured cornea express a very low level of K12 keratin. These observations are consistent with the notion that defective expression of K3/K12 keratins may play a role in the abnormal attachment of the regenerating epithelium to the basement membrane.

[Allosterism of acidic alcohol dehydrogenase (class III ADH) of mouse liver and its role in alcohol metabolism].

Two major ADH isozymes of mouse liver, basic ADH (Class I) and acidic ADH (Class III) were purified and the effects of various hydrophobic substances (t-butanol, butyramide, trifluoroethanol, trichloroacetic acid, stearic acid, oleamide, phenylalanine and norleucine) on their activities were investigated. All these hydrophobic substances activated acidic ADH with a range of from 15 to 560%, and reversely inactivated basic ADH activity with a range of from 10 to 100%, when 150 mmol/l ethanol was used as a substrate. Among these substances, t-butanol, which was the most potent activator of acidic ADH, enhanced the activity by 560% and completely inactivated basic ADH at a concentration of 1.0 mol/l. Kinetics studies demonstrated that the activation of acidic ADH by the hydrophobic substances was due to marked decreases of Km for ethanol in spite of decreases of Vmax, suggesting these substances were positive allosteric effectors for the isozyme. The inactivation of basic ADH by the hydrophobic substances was due to a decrease of Vmax without changing Km for ethanol. These results indicate that the activities of two ADH isozymes are regulated reversely by the hydrophobicity of the reaction environment which changes their kinetics constants. The ELISA method using the isozyme-specific antibody demonstrated that the content of acidic ADH in mouse liver was about 7 times larger than that of basic ADH (5.3 +/- 0.86 vs 0.72 +/- 0.06 mg/g-liver). In the light of the hydrophobic regulation of ADH isozyme activities and their liver contents, the role of acidic ADH on alcohol metabolism may be more predominant than basic ADH in the liver under hydrophobic condition.

Effects of chronic ethanol intoxication on aldehyde dehydrogenase in mouse liver.

Effects of chronic ethanol treatment with liquid diet (ethanol constituted 28% of the calories) on hepatic aldehyde dehydrogenase (ALDH) isozymes were studied in mice. One week of ethanol feeding caused 66% loss of mitochondrial low Km ALDH activity and 80% loss of mitochondrial high Km ALDH activity, compared with the control-fed group. However, these decreases recovered after 4 weeks of ethanol feeding. The cytosolic ALDH activity increased up to 140% after 10 weeks of ethanol feeding, compared with the control-fed group. Effects of acute ethanol injection on ALDH activity after prolonged ethanol feeding were studied. The severe acute ethanol injection (4.5 g/kg body wt) after 4 weeks of ethanol feeding caused a drastic decrease of the mitochondrial low Km ALDH activity; however, that did not affect the ethanol-fed group. After 10 weeks of ethanol feeding, acute ethanol injection (4.5 g/kg body wt) caused about twofold increase in mitochondrial low Km ALDH activity. From the agarose IEF study, it was found that ethanol intoxication does not affect the number and pI value of ALDH isozymes.

Isolation of wound-specific cDNA clones from a cDNA library prepared with mRNAs of alkali-burned rabbit corneas.

Alkali burn is one of the most severe corneal injuries. In order to gain a better understanding of the healing of alkali-burned corneas, it is necessary to identify and characterize proteins that are specifically synthesized by the injured corneal tissues. In this study, we developed a useful procedure to identify and isolate cDNA clones that encode messenger ribonucleic acids (mRNAs) that are specific and/or abundant in alkali-burned rabbit corneas (ARCs), but absent in normal rabbit corneas (NRCs). At first, a cDNA library was prepared by cloning cDNA of mRNA isolated from ARCs into the lambda ORF-8 vector. A differential plaque hybridization was used to screen 2.5 x 10(4) plaque-forming units (pfu) from an ARC cDNA library using 32P-labeled cDNAs prepared from mRNA of ARCs and NRCs. Thirty-seven cDNA clones of mRNAs specific for ARCs were identified and isolated in their pureform. The cDNA inserts of these lambda ORF-8 phages were subcloned into the pSM216 vector by in vivo recombination. The cDNA inserts then were characterized by restriction enzyme digestion, i.e., BamHI, HindIII, and EcoRI. The size of the cDNA inserts ranged from 210 to 5,000 base pairs. Using Northern blot hybridization of total RNA prepared from polymorphonuclear neutrophils, mononuclear leukocytes, alkali-burned corneas, and normal corneas, the cDNA clones were divided into three groups. Five cDNA clones encoded mRNA of corneal cells in ARCs. Twenty-four cDNA clones derived from mRNA of inflammatory cells were present in alkali-burned corneas, but Northern blot hybridization failed to identify mRNA of discrete sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of acute ethanol intoxication on aldehyde dehydrogenase in mouse liver.

To elucidate the effects of acute ethanol intoxication on hepatic aldehyde dehydrogenase (ALDH), the activities of these isozymes were measured after acute ethanol injection at the doses of 1, 3 or 5 g/Kg body weight in mice. At the same time, blood ethanol and acetaldehyde levels were measured to consider their correlation to the changes in ALDH activities. In the cytosolic fraction, acute ethanol injection caused no effects on high Km ALDH. However, low Km ALDH activity decreased significantly after 0.5 and 12 hr at the dose of 5 g/Kg body weight. In the granule fraction, acute ethanol injection caused more than 50% loss of low Km ALDH activity after 2 to 8 hr at the dose of 1 g/Kg and after 0.5 to 8 hr at the dose of 3 or 5 g/Kg body weight, in comparison with the untreated group. However, high Km ALDH activity decreased only after 4 hr at the dose of 3 or 5 g/Kg body weight. The elimination rate of blood ethanol was 158.0 mumol/min/1 and 125.6 mumol/min/1 after 0.5 to 4 hr of ethanol injection at the dose of 3 or 5 g/Kg body weight, respectively. However, these elimination rates decreased drastically after 4 to 8 hr following ethanol injection. The elimination rate of blood acetaldehyde was 116.6 nmol/min/1 after 1 to 2 hr, and the rate decreased to 6.9 nmol/min/1 after 2 to 8 hr following ethanol injection at the dose of 5 g/Kg body weight. These drastic decreases in acetaldehyde elimination rate appear to be caused by reduction of the granule low Km ALDH activity.