Role of the aldehyde dehydrogenase-1 isozyme in the metabolism of acetaldehyde

At least four types of aldehyde dehydrogenase (ALDH) isozymes exist in human liver: acetaldehyde (Ac-CHO) is metabolized mainly by ALDH2. However, the role of ALDH1 in Ac-CHO metabolism is not well known, because ALDH1 deficiency is rare. In the present study, changes in blood levels of Ac-CHO were analyzed in a person with ALDH1 deficiency who is also heterozygous for the ALDH2 alleles, and subjects with normal ALDH1, in order to clarify the roles of ALDH1 in the metabolism of Ac-CHO. By isoelectric focusing analysis of ALDH in red blood cells (RBC), the ALDH1 band was not detectable in a male subject, indicating ALDH1 deficiency. In this subject, ALDH1 activity was nearly null, but the activities in his wife and two children were normal. Serial changes of blood Ac-CHO levels following a small amount of ethanol were analyzed. The peak levels of Ac-CHO were not different between the subject with ALDH1 deficiency and the person with normal ALDH1. However, the decrease from the peak values of Ac-CHO was clearly slower in the deficient subject than in ALDH1 normal subjects. Changes in Ac-CHO in blood were also analyzed in vitro. Ac-CHO metabolism by RBC from the ALDH1 deficient subjects was clearly slower than in those from controls. These results indicate that ALDH1 plays an important role in the metabolism of Ac-CHO in blood.

Blood-brain barrier transfer of L-Trp and alpha-MTrp in Li-treated rats

Blood-brain barrier (BBB) transport for L-Trp and alpha-methyl-L-tryptophan was evaluated in Li-treated rats. Five different brain areas as well as left to right differences were examined. No left to right difference in the PS product was observed. Lithium treatment had a significant effect on the plasma concentration of Val, Leu and Ile but no effect on plasma total or free Trp. The ratio of plasma Trp to the sum of Leu, Val, Ile, Phe, Met and Tyr is increased in the Li-treated rats but not significantly. However, the ratio of Trp/(Val+Leu+Ile) is significantly increased in the Li-treated rats. The Km apparent (Kmapp) for the BBB Trp transport is significantly decreased (affinity of the carrier for Trp is increased) in the Li-treated rats. A decrease in the Kmapp is one of the possible factors responsible for an increase in the brain Trp concentration and subsequent increase in the brain serotonin synthesis in Li-treated rats.

The role of growth factor in wound healing

A pig wound healing model was developed to study the morphological processes involved in incisional and excisional wound healing, the immunohistochemical localization of TGF-alpha in wound healing, and the latter's relevance. In incisional wounds, a few layers of epidermis were regenerated after only 32 hours. In contrast, several layers of epidermis were regenerated on day 7 in excisional wounds. In general, the incisional wound model is useful for evaluating tensile strength, while the excisional wound model is suitable for evaluating epidermal regeneration. Immunohistochemical study showed that keratinocytes migrating from wound edges expressed TGF-alpha very faintly, while TGF-alpha was present prominently in the upper several layers of the epidermis adjacent to the wound, which resembled normal epidermis and showed no changes during the wound healing process.

Autoradiographic study of peripheral benzodiazepine receptors in animal brain tumor models and human gliomas

In vitro binding of [3H]PK-11195 (1-(2-chlorophenyl)-N-methyl-(1- methylpropyl)-3-isoquinoline carboxamide) in rodent AA ascites and C6 glioma as well as in human gliomas was investigated. The Bmax (mean +/- S.D.) of AA ascites tumor and C6 glioma is 1.39 +/- 0.15 pmol/mg tissue and 4.50 +/- 0.76 pmol/mg tissue, respectively. This Bmax is 9 and 30 times, respectively, higher than the one found in the rat cortex (0.15 +/- 0.03 pmol/mg tissue). A Bmax of 1.26 +/- 0.24 pmol/mg tissue and 0.64 +/- 0.08 pmol/mg tissue was found in human malignant and low grade gliomas respectively. This Bmax value should be compared to 0.35 +/- 0.04 pmol/mg tissue found in the normal human cortex. There are significant (P less than 0.05) differences between Bmax in tumors and normal cortex. There was no significant difference in KD between the malignant and low grade gliomas. C6 glioma has a KD significantly greater than rat cortex. In some cases of human low grade gliomas, kinetic measurements suggested the presence of two affinity receptor sites. However, at this time, heterogeneity of the tissue cannot be excluded as being at least in part a source of this.

Endothelins inhibit serotonin-induced platelet aggregation via a mechanism involving protein kinase C

Endothelins are a family of three peptides that act as local hormones released by the endothelium. They were found to inhibit rabbit and dog platelet aggregation in vivo, but no effect was observed in vitro. In order to investigate the possible interaction between endothelins and human platelet serotonin receptors, their effects on platelet aggregation induced by serotonin was studied. Endothelin-1, -2 and -3 had a dual action, on platelet aggregation and calcium mobilization induced by serotonin. When added at the same time as serotonin, endothelin potentiated the response to the amine. On the contrary, preincubation of platelet suspension with endothelin resulted in a concentration-dependent inhibition of the serotonin-mediated platelet response. Moreover, endothelin-1 inhibited serotonergic amplification of epinephrine-induced aggregation of platelets. We hypothesize that endothelins can bind to the platelet membrane and interact with serotonin receptors. The diverse effect of endothelins on serotonin-induced aggregation and calcium mobilization may be due to stimulation of protein kinase C.

The 55-kilodalton protein in an oriC complex fraction is glycogen synthase

Three proteins with molecular masses of 35, 55, and 75 kDa were found in an oriC complex fraction after purification through CsCl density gradient centrifugation (W. G. Hendrickson, T. Kusano, H. Yamaki, R. Balakrishnan, M. King, J. Murchie, and M. Schaechter, Cell 30:915-923, 1982). Of these three proteins, the 55-kDa protein was determined to be glycogen synthase on the basis of the N-terminal amino acid sequence and the molecular weight. The oriC complex was formed in glgA mutant cells, which produce no detectable glycogen, as well as in wild-type cells. None of the 35-, 55-, and 75-kDa proteins were detected in the fraction from this mutant. The results indicate that these proteins were not constituents of the oriC complex.

Expression of the angiotensinogen gene and localization of its protein in the human heart

BACKGROUND

There have been no reports on the presence of the tissue renin-angiotensin system in the human heart, although the presence of angiotensinogen has been described in the animal heart.

METHODS AND RESULTS

To determine whether angiotensinogen is synthesized in the human heart, we examined angiotensinogen messenger RNA (mRNA) synthesis in autopsy hearts by using ribonuclease protection assay. As a result, angiotensinogen mRNA was detected in the atrial muscle, muscles of the conduction system, and the left ventricular wall. In the left ventricular wall, mRNA expression was more prominent in the subendocardial muscles than in the midcardial or epicardial muscles. Using a monoclonal antibody to human angiotensinogen in immunoblotting experiments, we detected two closely spaced bands at approximately 70 kd in the heart, which was quite consistent with the human angiotensinogen molecule. Immunohistochemical studies with this monoclonal antibody demonstrated intense immunoreactivity in the atrial muscles, the muscles of the conduction system, and those of the subendocardial layers.

CONCLUSIONS

We conclude that angiotensinogen was synthesized in the human heart. It was evident that the localization of angiotensinogen was not ubiquitous in the cardiac muscles, showing its predilection for the atrial muscles, muscles of the conduction system, and subendocardial layer of the left ventricle.

[Microheterogeneity of serum glycoproteins in alcoholic liver disease]

It has been reported that microheterogeneity (M-HT) of serum glycoproteins including transferrin is found in alcoholic liver disease (ALD). In the present study, M-HT of serum glycoproteins in ALD patients was analyzed using the Western blotting technique after isoelectric focusing. M-HT was found in serum alpha 1-antitrypsin, alpha 2-macroglobulin, ceruloplasmin, alpha 1-acid glycoprotein and hemopexin as well as transferrin, but not in serum prealbumin. M-HT disappeared following treatment with sialidase in one group of glycoproteins, but not in another group of glycoproteins. In hemopexin, M-HT was recognized only after treatment with sialidase. These results suggest that mechanisms of the appearance of M-HT of serum glycoproteins in ALD may differ. One mechanism is the interference of glycosylation of glycoproteins in the Golgi apparatus, and another is the decrease of asialo-protein receptors in hepatocytes.

Blood serotonergic mechanisms in type 2 (non-insulin-dependent) diabetes mellitus

Serotonin (5-hydroxytryptamine, 5HT) is believed to play a role in vasospasm and increased platelet aggregability that in turn could contribute to atherosclerosis. The present study was designed to evaluate a possible participation of serotonin in the development of vascular complications in diabetes mellitus. Whole blood and plasma serotonin, the platelet uptake and release of the amine and serotonin- induced platelet aggregation were studied in 32 patients with Type 2 diabetes. The patients were divided into three groups according to the presence and advancement of retinopathy. Mean levels of blood serotonin content were significantly lower in diabetic patients. The concentration of the amine in the plasma was markedly increased in diabetes. It was correlated with vascular changes of the retina. We established that platelets from diabetic patients took up less serotonin when compared to the control group. Concomitantly enhanced spontaneous release of 5HT from platelets was observed. The platelets of diabetic patients showed increased response to serotonin. There was a relation between serotonin-induced aggregation and the presence of retinopathy. These results suggest that serotonin may be involved in the pathogenesis of diabetic vasculopathy.

Influence of the tumor mass on the valine rate constants and on valine incorporation into proteins in an experimental brain tumor model

Quantitative autoradiography was used to estimate regional transfer coefficients for valine incorporation and the rate of valine (exogenous and total) incorporation into proteins in an implanted brain-tumor model (AA ascites tumor). Special attention was paid to the evaluation of the tumor mass influence on the transfer coefficients and the rate of incorporation. The size of the tumors used in this study ranged from 2 to 5 mm in diameter. Nine groups of two to three animals each were used to determine the transfer coefficient. The transfer coefficients for movement of the label between different compartments were significantly greater in the tumor than in the normal brain. There is no tumor mass effect on the transfer coefficients or the rate of valine incorporation into proteins in surrounding or remote brain structures. The ratio between specific radioactivities of the free value in tissue and plasma was also measured. Results indicate that approximately the same fraction of the total valine is recycled in cortex as in the tumor tissue. The mean rates of exogenous valine incorporation into proteins (nmol g-1 min-1) is about one order of magnitude greater in the tumor than in the contralateral parietal cortex.

Effects of vitamin A on collagen metabolism by cultured rat liver cells

Conflicting results have been reported concerning the phenotypes of collagen produced by cultured Ito cells. These variations may be attributed to differences in pretreatment, i.e., with or without vitamin A to facilitate the separation of Ito cells. In the present study, the effects of vitamin A on collagen metabolism by Ito cells and hepatocytes of rats were analyzed. In cultured Ito cells, staining reactions to type I collagen increased, and those to type IV collagen and laminin decreased after pretreatment with vitamin A. The rate of collagen synthesis by Ito cells decreases significantly by treatment with vitamin A. The decrease was clearer in degraded collagen than in intact collagen. The synthesis of type I collagen increased and that of type IV collagen significantly decreased in Ito cells by treatment with vitamin A. In the hepatocytes, the staining reaction to type I collagen increased with vitamin A pretreatment. The net collagen and type III collagen synthesis in hepatocytes decreased by treatment with vitamin A. These results indicate that vitamin A modifies collagen metabolism in different cell types in different ways.

Plasminogen activators and plasminogen activator inhibitor 1 before and after venous occlusion of the upper limb in thromboangiitis obliterans (Buerger's disease)

Plasma levels of plasminogen activators (t-PA, u-PA) and their inhibitor (PAI-1) were studied in patients suffering from Buerger's disease and healthy volunteers before and after 15 minutes of venous occlusion test. The baseline levels of t-PA in group of patients did not differ from those of controls. On the contrary patients with Burger's disease showed a marked increase in u-PA antigen concentrations with concomitant decrease in PAI-1 antigen levels. During venous stasis t-PA antigen concentrations increased in all subjects, however it was much pronounced in controls. Venous occlusion resulted in significant decrease in free PAI-1 levels in the group of patients only. In conclusion, Buerger's disease is associated with the endothelial derangement with increased u-PA release and decreased PAI-1 release, which does not influence the function of fibrinolytic system. The fact that the reduced response of the endothelium to release t-PA after venous stasis goes in parallel with marked decrease in PAI-1 antigen levels seems to suggest that patients suffering from Buerger's disease are not at high risk of intravascular fibrin deposition.

Purification and characterization of formaldehyde dehydrogenase from rat liver cytosol

Formaldehyde dehydrogenase was purified to electrophoretic and column chromatographic homogeneity from rat liver cytosolic fraction by a procedure which includes ammonium sulfate precipitation, DEAE-cellulose-, hydroxyapatite-, Mono Q-chromatography, and gel filtration. Its molecular mass was estimated to be 41 kDa by gel filtration and SDS-PAGE, suggesting that it is a monomer. It utilized neither methylglyoxal nor aldehydes except formaldehyde as a substrate. It has been reported that liver class III alcohol dehydrogenase and formaldehyde dehydrogenase are the same enzyme and oxidize formaldehyde and long chain primary alcohols. However, the enzyme examined here did not use n-octanoi as a substrate. The Km values for formaldehyde and NAD+ were 5.09 and 2.34 microM at 25 degrees C, respectively. The amino acid sequences of 10 peptides obtained from the purified enzyme after digestion with either V8 protease or lysyl endopeptidase were determined. From these results, the enzyme was proved to be different from the previously described mammalian formaldehyde dehydrogenase and is the first true formaldehyde dehydrogenase to be isolated from a mammalian source.

Possible role of plasminogen activator inhibitor 2 in the prevention of the metastasis of gastric cancer tissues

The concentrations of urinary type plasminogen activator (u-PA), plasminogen activator inhibitor 1 (PAI-1), and PAI-2 were measured in gastric cancer tissues and adjacent healthy mucosal tissues. Levels of u-PA, PAI-1 and PAI-2 were higher in cancer than in control tissues. PAI-1 levels were higher together with the progression of cancer however there were no differences in u-PA or PAI-2 levels. Tumors with higher PAI-1 and lower PAI-2 levels tend to metastasize to remote lymph nodes. When the numbers of involved lymph nodes were analyzed, tumors with the large number of metastatic lymph nodes showed higher PAI-1 and lower PAI-2 level. No difference was shown in u-PA levels among these groups. These tendencies were more significant in patients with progressed gastric cancer. These results suggest that tumor with higher PAI-2 levels tend to localize or have less tendency to metastasize to lymph nodes. On the other hand PAI-1 was generally higher in tumor with invasion into nearby tissue or with nodal metastasis.

[Neo-adjuvant chemotherapy with cisplatin, 5-fluorouracil, vindesine in head and neck cancer]

Neo-adjuvant chemotherapy with CDDP combination was introduced into the treatment of advanced head and neck cancer. Twenty-three patients with s.c.c of head and neck were given combination chemotherapy consisting of CDDP, VDS and 5-FU before surgical treatment in our department. CR and PR of this trial in all patients were 4 and 35%, respectively. The WBC nadir occurred around 2 weeks later, but all the patients recovered prior to the next cycle or surgical treatment. Renal dysfunction, nausea, vomiting and depilation were generally mild. VDS is useful as one of the neo-adjuvant drugs for the treatment of head and neck cancer. Long-term observation in connection with this treatment is required.

Changes in the markers related to collagen synthesis in the liver of chronically alcohol treated rats

In order to clarify the roles of Ito cells in the development of alcoholic fibrosis, markers related to collagen synthesis in the liver were analyzed in chronically alcohol treated rats. The livers were obtained from rats fed a diet containing alcohol (alcohol group) and those fed a control diet (control group) for 4 weeks. Prolyl hydroxylase (PH) activity in the whole liver tissue did not differ in the alcohol and control groups. However, the activity in the isolated Ito cells was significantly higher in the alcohol group than in the control group. Immunoreactive PH beta-subunit contents in the liver and serum were significantly higher in the alcohol group than in the control group. Hydroxyproline contents in the liver did not differ in either groups. Immunohistochemically, type IV collagen and laminin were clearly stained along with the sinusoid in the livers of the alcohol group. However, the staining reactions were very weak in the control group. Staining reactions to types I and III collagen were very weak or almost absent in the livers of both groups. Desmin-positive cells, along with the sinusoid, increased significantly in the alcohol group, especially at the centrilobular area, suggesting that the number of Ito cell increase in the centrilobular areas of the alcohol treated rats. These results suggest that type IV collagen and laminin synthesis increase in the Ito cells of chronically alcohol treated rats, although clear evidence of hepatic fibrosis was not obtained. This increase may be related to capillarization of the sinusoids and finally to the development of perisinusoidal fibrosis in alcoholics.

[Inhibition of serotonin-induced platelet aggregation by endothelins]

Endothelins are a family of three peptides that act as local hormones in all mammalian species. They were found to inhibit rabbit and dog platelet aggregation in vivo, whereas no effect was observed in vitro. In order to investigate the possible interaction between endothelins and human platelet serotonergic receptors, their effect on the platelet aggregation, induced by serotonin, was studied. Endothelin-1, -2 and -3 had a dual action for platelet aggregation induced by serotonin. When added simultaneously to serotonin endothelins aggregatory response to this amine was potentiated. On the contrary, preincubation of platelet suspension with endothelins resulted in a concentration-dependent inhibition of serotonin-promoted platelet response. Moreover, endothelin-1 inhibited serotonergic amplification of epinephrine-induced aggregation of platelets. It is proposed that endothelins bind to the platelet membrane and interact with serotonergic receptors and/or G proteins. The diverse effect of eodothelins on serotonin-induced aggregation of platelets may be due to stimulation of protein kinase C.

Plasminogen activator system in human breast cancer

We measured antigen levels of 2 kinds of plasminogen activator, tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (UK), as well as those of their primary inhibitors, type-I plasminogen activator inhibitor (PAI-1) and type-2 plasminogen activator inhibitor (PAI-2), in tissue extracts from benign and malignant breast tumors. Tumor tissue samples from 40 fibroadenomas and 40 breast cancers were examined. t-PA antigen levels were the same in the 2 groups. Malignant tumors contained higher levels of UK antigen than did benign tumors. In the case of breast cancer, UK antigen levels of tumors with axillary lymph-node involvement were significantly higher than those of tumors without lymph-node involvement. PAI-1 and PAI-2 antigen levels of breast-cancer tissue samples were higher than those of fibroadenoma samples. PAI-1 antigen levels of carcinomas with lymph-node involvement were also significantly higher than those of carcinomas without node involvement. PAI-2 antigen levels, on the contrary, were higher in carcinomas without node involvement. UK, PAI-1 and PAI-2 antigen levels are potentially excellent independent factors for prediction of the metastatic potential of breast cancers.

Clinical backgrounds of the patients having different types of hepatitis C virus genomes

Hepatitis C virus (HCV) genomes were recently detected in biological materials, and variations of nucleotide sequences were reported. In the present study, typing of the HCV genomes was performed in 91 HCV-RNA-positive patients and the clinical features of patients with different types of HCV were compared. From the nucleotide sequences of the cDNA fragments, HCV can be divided into at least two types: HCV-K1-PT and HCV-K2. All cDNAs amplified from 91 patients were hybridized with cDNA probes of either HCV-K1-PT or HCV-K2. HCV-K1-PT was found in about 80% of the patients, and HCV-K2 was found in about 20% of the patients. These results indicate that types of HCV are limited to two types, i.e., K1-PT and K2, and the major type is HCV-K1-PT, at least in Japan. Detection rate of antibodies to C-100-3 protein were not different between the patients having HCV-K1-PT and HCV-K2, indicating that the antibodies may develop in HCV-related patients without relation to the types of the HCV genomes. Prevalence of the two types of HCV were nearly the same in various forms of NANB-related liver disease. However, the prevalence was somewhat different in alcoholic liver disease. HCV-K2 was found in patients younger than the patients with HCV-K1-PT. Frequency of a history of blood transfusion tended to be lower and the initial response to interferon treatment was clearly better in patients having HCV-K2 versus patients having HCV-K1-PT. These results suggest the possibility that clinical features due to HCV-K1 may be somewhat different from those due to HCV-K1-PT. However, the number of patients examined was too small to allow a definite conclusion, indicating a necessity for further study with a larger number of patients.

Relationship between serotonergic measures in periphery and the brain of mouse

Circadian rhythm and the relationship between the concentration of serotonin (5HT) and related substances (5-hydroxyindoleacetic acid; 5HIAA and tryptophan; Trp) in mouse brain, stomach and blood have been studied. All factors underwent circadian changes in the brain and blood. 5HT and 5HIAA levels in the stomach showed no circadian fluctuation. The concentrations of 5HT in the brain and blood did not correlate. Significant correlations were found between other serotonergic parameters analyzed in brain, stomach and blood. A significant negative correlation was observed between brain 5HIAA and blood 5HIAA. The concentration of tryptophan in the brain was correlated with the plasma total tryptophan level. There was fairly significant correlation (p less than 0.06) between brain serotonin and plasma tryptophan levels. The brain serotonin and tryptophan levels were strongly correlated (R = 0.410, p less than 0.03). Significant negative correlation was found between serotonin in the blood and serotonin in the stomach as well as between its level in the brain and in the stomach. The significance of these findings and their relationship to the use of peripheral serotonergic system as a model of neurons are discussed.

Molecular characterization of a JC virus (Sap-1) clone derived from a cerebellar form of progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by polyomavirus JC (JCV). In the majority of cases of PML the cerebrum is mainly affected (cerebral PML) but on rare occasions lesions are restricted to the cerebellum and brain stem (cerebellar PML). We report a rare cerebellar PML case which occurred in a Japanese patient undergoing prolonged hemodialysis treatment. To understand the molecular basis of the viral tissue tropism, we molecularly cloned JCV DNA and compared it with those of cerebral PML. Of ten clones analyzed nine showed identical fragment patterns after digestion with various restriction endonucleases, and we designated these clones Sap-1. It could be shown that the basic structures of the regulatory regions are similar between Sap-1 and isolates from cerebral PML. Restriction endonuclease mapping analysis was used to examine the genetic relationship between Sap-1 and urine-derived isolates containing the archetypal regulatory sequence. We found that Sap-1 was genetically related to an archetypal JCV isolate in Japan.