Low activity of branched-chain alpha-keto acid dehydrogenase complex in human liver.
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3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
Biomedical subjects
H Takagi
Publications and source records attributed to H Takagi.
Pathogenesis of adenocarcinoma induced by gastrojejunostomy in Wistar rats: role of duodenogastric reflux.
The pathogenetic effect of duodenogastric reflux of the development of gastric stump carcinoma was studied experimentally. In this animal model, 95 male Wistar rats were subjected to a specially designed gastrojejunostomy to divert the duodenal contents into the resected stomach through the afferent and efferent loop. The rats were fed normally without any carcinogen administration. The incidence of adenocarcinomas around the anastomosis of afferent loop was 0% at 10 weeks, 18.8% at 20 weeks and 34.4% at 40 weeks, so the incidence was apt to rise in parallel with passing of the weeks. At 40 weeks, the rats had a significantly higher incidence of adenocarcinoma in the gastric mucosa around the afferent loop than around the efferent loop (P < 0.05). Of particular interest is that invasive growth of the cancerous tissue into the liver was observed in one animal. Polypoid lesions called 'atypical hyperplasia' in the present study were similar to gastritis cystica polyposa of humans. The development of adenocarcinoma was found to be intimately connected with atypical hyperplasia, which might be promoted by repeated destruction and regeneration by duodenogastric reflux. These results suggest that the direct contact of the duodenal juice with the gastric mucosa induces carcinoma in the anastomotic lesion. From the clinical perspective, our findings suggest that a surgical technique that minimizes the duodenogastric reflux should be chosen.
Adenocarcinoma↗
Intraportal endovascular ultrasonography in the diagnosis of portal vein invasion by pancreatobiliary carcinoma.
OBJECTIVE: The purpose of this study was to determine the value of intraportal endovascular ultrasonography (IPEUS) in the diagnosis of portal vein invasion by pancreatobiliary carcinoma. The authors reported their experiences with this new technique and compared it with conventional imaging technologies, such as portography and computed tomography (CT). SUMMARY BACKGROUND DATA: Pancreatobiliary carcinoma often invades the portal vein. Observation of the echogenic band of the portal vein wall by means of a high-frequency, high-resolution intravascular ultrasound catheter allows for the accurate diagnosis of the portal vein invasion. METHODS: A prospective study of 30 consecutive patients with pancreatobiliary carcinoma (16 pancreatic carcinomas, 8 bile duct carcinomas and 6 gallbladder carcinomas) was performed. In 23 cases IPEUS was performed intraoperatively from the superior mesenteric venous route with an 8 French, 20 MHz intravascular ultrasound catheter. In 7 cases IPEUS was performed before surgery from the percutaneous transhepatic route with a 6 French, 20 MHz intravascular ultrasound catheter. The finding of IPEUS was confirmed by pathologic examination of resected specimens and surgical exploration. The results of IPEUS were compared to those of portography and CT. RESULTS: Intraportal endovascular ultrasonography visualized the portal vein wall as an echogenic band with a thickness of 0.5 mm to 1.0 mm. The diagnostic criterion of portal vein invasion was destruction of this echogenic band. Portal vein invasion was found in 15 of 30 cases. Vascular invasion was confirmed by pathologic examination of resected specimens in 10 patients and operative findings in 5. The sensitivity, specificity, and overall accuracy of IPEUS for diagnosis of portal vein invasion was 100%, 93.3%, and 96.7%, respectively. The values were 80%, 67.7%, and 73.3% for portography and 53.3%, 80%, and 66.7%, respectively, for CT. CONCLUSIONS: Intraportal endovascular ultrasonography provided precise information about the relationship between the pancreatobiliary tumor and the portal vein wall. It was capable of accurately detecting or excluding early invasion of the portal vein wall by pancreatobiliary carcinoma.
Aged↗
Detection of superoxide free radicals in rats with acute pancreatitis.
To study the importance of oxygen-derived free radicals in acute pancreatitis, an experimental study of in vivo detection of superoxide free radicals (O2-) was performed using rats. Using a new chemiluminescence probe (2-methyl-6-[p-methoxyphenyl]-3,7-dihydro-imidazol[1,2-1]pyrazin- 3-one; MCLA; a Cypridina luciferin analogue) and a highly sensitive photon counting system, O2- from the pancreatic surface of rats with experimental acute pancreatitis induced by 180 micrograms cerulein/kg was detected. The time course of MCLA-dependent luminescence suggested that O2- production began 2-3 h after cerulein injection and then decreased gradually. Superoxide free radical production in the pancreas of rats with cerulein-induced acute pancreatitis was confirmed using MCLA-dependent chemiluminescence. This new method allows direct observation of the behavior of oxygen-derived free radicals.
Acute Disease↗
Human dermal fibroblast clones derived from single cells are heterogeneous in the production of mRNAs for alpha 1(I) procollagen and transforming growth factor-beta 1.
Fibroblast clonal heterogeneity has been reported for growth and protein synthesis, but quantitative studies of synthetic phenotype at the pretranslational level have been limited because of difficulty in reliably growing large numbers of clonal cells. We have recently shown a unique stimulatory activity of low oxygen tension in the early phases of clonal growth, which can be used to establish clonal fibroblast cultures suitable for Northern analysis. Using this methodology, we have measured mRNA levels of alpha 1(I) procollagen and transforming growth factor-beta 1 (TGF-beta) both at baseline and after TGF-beta stimulation in a total of 43 clones derived from single cells and from seven different cell strains. We report a remarkable baseline heterogeneity, commonly four- to six-fold, in procollagen mRNA levels among clones and between clones and their parent cultures. Conversely, differences in baseline TGF-beta mRNA levels among clones were either not present or less than onefold. The clonal phenotypic expression of alpha 1(I) procollagen mRNA remained stable after eight additional cell passages. TGF-beta stimulation of itself (autoinduction) was highly variable among clones (range of increases 30% to 150%), and up-regulation of procollagen mRNA levels after TGF-beta stimulation was detected in only 15 (54%) of 28 clonal cultures (range of increases 30% to 353%). A notable lack of correlation was found between baseline mRNA levels of TGF-beta and alpha 1(I) procollagen in clonal cultures. In conclusion, fibroblast clonal populations are remarkably heterogeneous in their baseline procollagen mRNA levels and in their response to TGF-beta.
Adult↗
Detection of hepatic micrometastasis in pancreatic adenocarcinoma patients by two-stage polymerase chain reaction/restriction fragment length polymorphism analysis.
Hepatic metastasis and retroperitoneal recurrence generally are considered to be the two primary modes of recurrence in pancreatic cancer. The goal of this study was to determine if patients with pancreatic adenocarcinoma have hepatic and peritoneal micrometastasis at operation. Pancreatic adenocarcinomas are known to have a high incidence of K-ras gene mutations. Liver tissue specimens were obtained from 30 patients (17 with pancreatic adenocarcinoma and 13 with other diseases) with a biopsy needle at operation. Peritoneal washings were obtained during operation from 20 patients with pancreatic adenocarcinoma. Two-stage polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were used to detect K-ras oncogene mutation at codon 12. Thirteen of 17 pancreatic adenocarcinoma patients had K-ras gene mutations in the liver, whereas all 13 patients with other diseases did not. However, only two of 20 pancreatic adenocarcinoma patients revealed K-ras gene mutation in peritoneal lavage fluids. These results indicate the feasibility of detecting hepatic micrometastasis in patients with pancreatic adenocarcinoma, and imply that PCR/RFLP analysis may be of value in the diagnosis, treatment and follow-up of hepatic metastasis of pancreatic adenocarcinoma.
Adenocarcinoma↗
Frequent genetic instability in small intestinal carcinomas.
To determine whether genetic instability plays a part in the development of digestive tract carcinomas, we analyzed 3 microsatellite loci isolated from tumors and surrounding normal tissue samples obtained during surgery. The polymerase chain reaction (PCR) technique was used to assess differences between tumor and matched normal DNAs. Replication errors (RERs) were observed in 3 of the 29 cases (10%) of gastric carcinoma and in 11 of the 72 cases (15%) of colorectal carcinoma. None of the 13 (0%) esophageal carcinoma cases showed any RER, but 5 of the 11 cases of small intestinal carcinoma (45%) had RERs, a significantly frequent finding. These results suggest that genetic instability plays an important role in the pathogenesis of small intestinal carcinomas.
Colorectal Neoplasms↗
Increased susceptibility to N-nitrosomethylurea gastric carcinogenesis in transforming growth factor alpha transgenic mice with gastric hyperplasia.
Glandular stomach carcinogenesis after N-nitrosomethylurea (NMU) treatment was examined in transgenic mice bearing a human transforming growth factor alpha (TGF-alpha) cDNA driven by the mouse metallothionein-I promoter (mouse line MT100) in the inbred mouse line FVB/N. Untreated MT100 mice exhibit a severe age-related gastric fundic hyperplasia. Both sexes of MT100 mice were given 10 weekly intragastric intubations of 0.5 mg NMU per mouse from 6 weeks of age and/or zinc chloride in drinking water to stimulate transgene expression from 5.5 weeks of age to the experiment termination. Animals were killed sequentially at 10, 19 and 29 experimental weeks. Several histochemical markers (AB-PAS, TGF-alpha, pepsinogen isozyme 1, proliferating cell nuclear antigen) were used. Abnormal histochemical patterns were found in untreated MT100 and NMU-treated MT100 mice for all 4 markers of differentiation and carcinogenesis. Precancerous lesions including atypical and/or adenomatous hyperplasia were found in the fundic region of 16/22 male and 8/22 female MT100 mice but not in 27 male and 24 female FVB/N mice treated with NMU. One of 22 MT100 males had fundic carcinoma. FVB/N mice treated with NMU had neither precancerous lesions nor carcinomas in the fundus. Well differentiated adenocarcinomas in the pyloric region were induced at incidences of 2/22 male and 1/22 female MT100 mice treated with NMU and 4/27 male and 4/24 female FVB/N mice treated with NMU. Both strains also had a high incidence (55 to 92%) of squamous cell carcinomas of the forestomach. In conclusion, TGF-alpha induced a hyperplastic lesion in the gastric fundus that appeared to predispose the MT100 mice to carcinogenesis by NMU.
Adenocarcinoma↗
Development of an isolated perfusion circuit with double bypass using automatic blood pumps.
Isolated perfusion of the liver is a useful and promising therapeutic method for various hepatic diseases. However, conventional techniques using a roller pump require a large priming volume and cannot run at the low flow rate without complications. These disadvantages do not allow the use of conventional techniques in smaller pediatric patients. The authors solved these problems successfully for the first time by using unique sac-type air-driven automatic blood pumps with an oxygenator primed with a blood volume of 65 ml in the total circuit. The usefulness of these blood pumps for liver perfusion was evaluated in small animals weighing 3.5-6.0 kg. A hepatic perfusion circuit was established between the portal vein and the inferior vena cava. The blood pumps worked well without any trouble, and stable flow could be maintained. No hepatocellular damage or anaerobiosis of the liver was observed at a hepatic perfusion flow rate of 20 ml/min/kg. Isolated liver perfusion using these blood pumps can be applied in infants and young children.
Analysis of Variance↗
The role of the spleen in endotoxin-induced liver injury.
In these experiments, the role of the spleen in endotoxin-induced liver injury was evaluated, using rats which underwent splenectomy or splenic vein ligation with antecedent spleno-systemic shunt. Male Wistar rats were divided into three groups: a sham-operated group, a splenectomy group, and a splenic vein ligation group. In each animal, 48 h after surgery, 5 mg/kg lipopolysaccharide (LPS) were injected intravenously. Six rats from each group were sacrificed 6 or 12 h after LPS administration. Bronchoalveolar lavage fluid (BALF) and arterial blood were also collected. Splenectomy reduced the liver injury as indicated by the serum lactate dehydrogenase level. A decrease in liver tissue adenosine triphosphate and increase in lipid peroxide were induced by LPS administration and inhibited by splenectomy. Splenectomy also reduced alveolar protein release as indicated by the protein level in BALF. Splenic vein ligation provided similar protective effects on the liver, but did not affect lung injury. From these results, it appears that the spleen plays a significant role in endotoxin-induced liver injury, and a mediator derived from the spleen is likely associated with development of liver injury. This mediator may be cleared or inactivated by not only splenectomy but also splenic vein ligation.
Adenosine Triphosphate↗
Nucleotide sequence and replication properties of the Bacillus borstelensis cryptic plasmid pHT926.
The nucleotide sequence of pHT926, a cryptic plasmid found in Bacillus borstelensis HP926, was determined. pHT926 replicates by a rolling-circle mechanism and belongs to the pC194 plasmid family. The copy number of pHT926 was fourfold higher than that of pUB110 and very stably maintained in Bacillus choshinensis.
Amino Acid Sequence↗
Effectiveness of Carolina rinse solution after cold ischemic storage of rat livers: biochemical and histological analysis using perfusion model.
Using a rat liver perfusion model, the effectiveness of Carolina rinse solution was assessed for the prevention of reperfusion injury after 48 h of cold storage in UW solution. Transaminase levels (GOT, GPT and LDH) of the perfusate were significantly higher in the Ringer group (17 +/- 8, 17 +/- 9 and 191 +/- 97 IU/l, respectively) than in the Carolina group (6 +/- 4, 5 +/- 4 and 21 +/- 20 IU/l) (p < 0.05). The levels of oxygen consumption were also higher in the Carolina group (233 +/- 54 mm Hg) than in the Ringer group (164 +/- 58 mm Hg) (p < 0.05). Histological examination showed severe parenchymal cell damage in the Ringer group, whereas the damage was slight in the Carolina group. Two newly developed monoclonal antibodies, REC16-11 and REC4-1, which specifically react with rat endothelial cells, were used for immunohistochemical studies of the livers. The endothelial cells of central vein and sinusoids were more severely damaged in the Ringer group than in the Carolina group. The present study suggests that Carolina rinse solution is useful for prevention of liver damage from reperfusion injury after cold storage of the graft for organ transplantation.
Animals↗
Heparin effects on superoxide production by neutrophils.
Heparin is widely used in the treatment of various diseases, but the mechanisms of its biologic actions remain largely obscure. Recently, oxygen radicals, which are produced in a variety of conditions and cause tissue damage, have been implicated in the pathophysiology of various diseases. To investigate the relationship between heparin and oxygen radical production by neutrophils, we compared the effects of standard heparin (heparin sodium), which has been widely used, and a recently developed low molecular weight heparin (LMWH) which has potent anti-Xa activity, on neutrophil oxygen radical production in vitro. Standard heparin increased neutrophil oxygen radical production slightly at the low concentrations used clinically but reduced it at high concentrations, so that the effect of heparin on neutrophil oxygen radical production was biphasic. The effects of LMWH on neutrophil oxygen radical production were slight at both low and high concentrations. In disseminated intravascular coagulation (DIC) locally activated neutrophils produce oxygen radicals and have toxic effects in vivo. Thus we concluded that LMWH should be indicated for the treatment of DIC.
Free Radicals↗
Immunohistochemical staining for endotoxin using horseshoe crab factor C in fecal peritonitis.
The object of the present study was to apply a new immunohistochemical staining method to the in vivo determination of endotoxin localization. The immunohistochemical staining method requires factor C (an initiation factor in the Limulus clotting system which is mediated by endotoxin) as a specific ligand of endotoxin, and a newly developed murine monoclonal antibody to factor C. The blood endotoxin level and endotoxin localization in the rat were determined before and at 6, 12 and 24 h after intraperitoneal injection of 0.25 g/kg of fresh rat feces. The greatest blood endotoxin level was achieved at 12 h after the injection, and uptake of endotoxin was evident in Kupffer cells in the liver at 24 h after the injection. There has been no report on determining endotoxin localization in cases of endotoxemia attributed to fecal peritonitis. This new immunohistochemical staining method for determining endotoxin localization will contribute to the histopathological diagnosis of endotoxemia in humans.
Animals↗
Enhanced collagen synthesis and transcription by peak E, a contaminant of L-tryptophan preparations associated with the eosinophilia myalgia syndrome epidemic.
The pathogenesis of the eosinophilia myalgia syndrome (EMS) remains unclear. Several abnormal constituents have been found in the L-tryptophan lots responsible for the illness, particularly, 1,1-ethylidenebis[L-tryptophan], also called peak E or EBT, and 3-phenylamino-alanine or peak 5. However, the role of these contaminants in the pathogenesis of EMS and in the development of fibrosis is unknown. We now report that peak E, a dimer of L-tryptophan, is a potent stimulus for human dermal fibroblast DNA and collagen synthesis. Peak E (0.1-1.0 microM) increased DNA synthesis up to four-fold (P = 0.0001) in a dose-dependent manner (r = 0.987). When added to monolayer cultures for 2 to 24 h, peak E (0.5 to 100 microM) caused a progressive, more than threefold increase in alpha 1(I) procollagen mRNA levels and collagenous protein. No increase in procollagen mRNA levels was found after the addition of another major L-tryptophan contaminant, peak 5, or with L-tryptophan itself. Transient transfection with a 2.5-kb alpha 1(I) procollagen promoter-luciferase construct showed that peak E causes a twofold upregulation of promoter activity (P = 0.022). Contraction of collagen gels, consisting of human dermal fibroblasts incorporated into a type I collagen lattice, was enhanced two-fold by exposure to peak E (P = 0.001). We conclude that a major constituent of contaminated batches of L-tryptophan, peak E, is a potent stimulus for fibroblast activation and collagen synthesis. This stimulatory action of peak E may provide a direct mechanism for the development of fibrosis in EMS.
Cells, Cultured↗
Transforming growth factor alpha disrupts the normal program of cellular differentiation in the gastric mucosa of transgenic mice.
Transforming growth factor alpha (TGF alpha) evokes diverse responses in transgenic mouse tissues in which it is over-expressed, including the gastric mucosa, which experiences aberrant growth and a coincident repression of hydrochloric acid production. Here we show that ectopically expressed TGF alpha induces an age-dependent cellular reorganization of the transgenic stomach, in which the surface mucous cell population in the gastric pit is greatly expanded at the expense of cells in the glandular base. Immunohistochemical analysis of BrdU incorporation into DNA demonstrated that although mature surface mucous cells were not proliferating, DNA synthesis was enhanced by approximately 67% in the glandular base and isthmus, where progenitor cells reside. RNA blot and in situ hybridization were employed to determine temporal and spatial expression patterns of specific markers representing a variety of exocrine and endocrine gastric cell types. Mature parietal and chief cells were specifically depleted from the glandular mucosa, as judged by a 6- to 7-fold decrease in the expression of genes encoding H+,K(+)-ATPase, which is required for acid secretion, and pepsinogen C, respectively. The reduction of these markers coincided in time with the activation of TGF alpha transgene expression in the neonatal stomach. The rate of cell death in the glandular region was not overtly different. Significantly, the loss of parietal and chief cells occurred without a concomitant loss of their respective cellular precursors. In contrast to exocrine cells, D and G endocrine cells were much less severely affected, based on analysis of somatostatin and gastrin expression. Analysis of these dynamic changes indicates that TGF alpha can induce selective alterations in terminal differentiation and proliferation in the gastric mucosa, and suggests that TGF alpha plays an important physiological role in the normal regulation of epithelial cell renewal.
Animals↗
Production and characterization of keratinase of a feather-degrading Bacillus licheniformis PWD-1.
The keratinase produced by Bacillus licheniformis PWD-1 was induced by feather powder. Maximal enzyme production could be achieved by culturing in a medium containing 1% hammer-milled feather powder (100 mesh) at 45 degrees C for 30 h. Maximal growth of PWD-1 was achieved at 50 degrees C, and maximal enzyme induction was at 45 degrees C. The molecular mass and isoelectric point of this enzyme were 31.4 kDa and 8.5, respectively. This enzyme was stable from pH 5 to 12. The optimal reaction pHs for feather powder and casein were 8.5 and 10.5 to 11.5, respectively. The optimal reaction temperature was 50 degrees C to 55 degrees C. The relative activity of this enzyme toward casein, feather powder, keratin, elastin, and collagen was 100:52:41:18:7, and 100:56:32:3 for Suc-AAPL-pNA, Suc-AAPF-pNA, Suc-AAPM-pNA, and Suc-AAVA-pNA (Suc, succinyl; pNA, p-nitrophenylanilide).
Amino Acid Sequence↗
Adrenocorticotropic hormone (ACTH) increases the expression of its own receptor gene.
Regulation of the ACTH receptor (R) in the adrenal gland by its own ligand "ACTH" has been a matter of controversy. In the present study, whether ACTH regulates the expression of mRNA for its own receptor in the adrenal gland was studied in human subjects and in rats in vivo. In the human study, adrenal adenoma tissues as well as adjacent normal tissues were obtained at surgery from two patients with typical Cushing's syndrome. Northern blot analysis revealed two ACTH-R mRNA species with 4.0 kb and 2.0 kb. ACTH-R mRNAs in the adenoma tissues were much more abundant than those in the normal tissues from the two patients, suggesting that the mRNA in normal adrenal tissue is either suppressed by cortisol excess or the absence of ACTH. To examine the mechanism involved in ACTH-R mRNA regulation, the changes in the receptor mRNA caused by ACTH were studied in dexamethasone-treated rats. Administration of dexamethasone for 5 days resulted in a marked decrease in ACTH-R mRNA to an undetectable level. A bolus administration of ACTH1-24 intravenously or ACTH-Z1-24 intramuscularly to the dexamethasone-treated rat did not cause any significant change in ACTH-R mRNA from 0.5 to 12 h after the administration. However, a significant increase in the receptor mRNA was observed at 24 h after the ACTH-Z1-24 and the level was further increased until 48 h followed by a sustained increase at 72 h when it was given once every 24 h. These data suggest that the ACTH-receptor is increased by ACTH at a pretranslational level.(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenocorticotropic Hormone↗