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Biomedical subjects

H Wakabayashi

Publications and source records attributed to H Wakabayashi.

At least 37 records · Page 2Linked to original sources

Rhodium-catalyzed reformatsky-type reaction

A novel Reformatsky-type reaction was developed using RhCl(PPh(3))(3) and diethylzinc. Inter- and intramolecular Reformatsky-type reactions were achieved efficiently under mild reaction conditions to give beta-hydroxy esters.

Journal Article↗

Light and Oxygen Protective Properties of Materials Induced by Surfactant Molecular Complex Formation.

Crystalline surfactant molecular complexes, the quite stable existence of which we firmly established through X-ray structural analysis, etc., were examined with respect to the protection from UV light and oxygen provided to their additive components. Structural analysis has revealed that the complex additives are stably occluded in the mother surfactant crystal matrix. Through the examination it was confirmed that additive components in a cationic complex crystal structure were perfectly protected from both UV light and oxygen. On the other hand, in anionics the additives were perfectly safe from UV attack, but from oxygen the change was rather accelerated in comparison with the effect of that on the pure condition. Copyright 2000 Academic Press.

Journal Article↗

14-3-3tau associates with a translational control factor FKBP12-rapamycin-associated protein in T-cells after stimulation by pervanadate.

Proteins of the 14-3-3 family can associate with and/or modulate the activities of a variety of proteins, such as protooncogene and oncogene products, Cdc25 phosphatases and phosphatidylinositol 3-kinase, and thus are implicated in regulation of signaling pathways and the cell cycle. We report here that treatment of Jurkat T-cells with an inhibitor of protein tyrosine phosphatase, pervanadate, induces the association of 14-3-3tau with a translational control factor, FKBP12-rapamycin-associated protein (FRAP), with significant latter's autophosphorylation. Coimmunoprecipitation of various mutants of FRAP coexpressed with 14-3-3tau in COS-7 cells revealed that 14-3-3tau binds to the C-terminal side of FRAP at unknown site(s) different from the predicted binding motifs to date.

14-3-3 Proteins↗

Lidocaine-metabolizing activity after warm ischemia and reperfusion of the rat liver in vivo.

The effect of warm ischemia on lidocaine-metabolizing activity was examined in vivo. Total liver ischemia was produced for 1 hr in Sprague-Dawley rats by clamping the portal vein and hepatic artery at the hilum. Livers were then reperfused, and liver microsomes were prepared before and 0, 2, 6, and 24 hr, and 3, 6, and 10 days after reperfusion. Microsomal lidocaine-metabolizing activity and cytochrome P-450 content were examined. Lidocaine N-deethylase activity was decreased from 2.25 +/- 0.33 to 0.97 +/- 0.21 nmol/mg protein/min (mean +/- SD) 24 hr after reperfusion. This inhibition was prolonged, and activity gradually recovered after 10 days. The cytochrome P-450 content showed the same tendency. On the other hand, serum levels of alanine aminotransferase increased significantly 2 hr after reperfusion and returned to control levels 3 days after reperfusion. Liver blood flow recovered rapidly after unclamping and reached baseline levels within 6 hr. Our results suggest that after warm ischemia, prolonged hepatic dysfunction in drug metabolism, which cannot be detected by evaluating serum enzymes or liver blood flow, exists at the microsomal level.

Alanine Transaminase↗

Measurement of serum hyaluronate as a predictor of human liver failure after major hepatectomy.

Serum hyaluronate can be used as an index of hepatic sinusoidal endothelial cell function. This study was designed to evaluate its application as a predictor of liver failure after major hepatectomy. Thirty-six patients who underwent right liver lobectomy after percutaneous transhepatic right branch portal vein embolization were divided into two groups based on their postoperative clinical course (groups 1 and 2, with and without postoperative liver failure, n = 6 and n = 30, respectively). We serially measured serum hyaluronate levels using a sandwich binding protein assay system before and after hepatectomy and determined relations with progression of the underlying chronic liver disorder, portal venous pressure, and liver growth of the left lobe after portal embolization. Serum hyaluronate levels were significantly elevated, in line with the degree of severity of the underlying chronic liver disorder, and correlated well with the portal venous pressure and the hypertrophic ratio of the left lobe subsequent to portal embolization. Serum hyaluronate levels in group 1 were significantly higher than those in group 2 before surgery and increased steeply during the early period after hepatectomy. These results suggest that the serum hyaluronate reflects the hepatic functional reserve, and serial measurement of this parameter after hepatectomy can serve as a simple indicator for early detection of posthepatectomy liver failure.

Biomarkers↗

Extent of pathologic invasion of the inferior vena cava in resected liver cancer compared with possible caval invasion diagnosed by preoperative images.

The extent of cancerous invasion of the inferior vena cava (IVC) determined from resected liver cancer was examined pathologically. Ten patients presenting with liver cancer (metastatic liver cancer, five patients; hepatocellular carcinoma, three; and cholangiocellular carcinoma, two) were diagnosed with positive IVC invasion using preoperative imaging techniques of extracorporeal ultrasonography, computed tomography, magnetic resonance imaging, and vena cavography. The diagnostic criterion for positive IVC invasion by preoperative imaging was longitudinal IVC compression measuring over 50 mm, or transverse IVC compression extending to more than half the circumference of the IVC, or the presence of lesions protruding into the IVC lumen, or the presence of developed collateral veins. All patients underwent combined resection of the IVC. However, pathology results revealed that four of the ten patients had no cancerous invasion of the IVC, and that the extent of invasion along both the longitudinal and transverse axes of the IVC was much smaller than the compression shown by imaging results. We believe that detailed preoperative assessment, using a more precise imaging technique, as well as further intraoperative examination, is required to predict the full pathological extent of cancerous invasion of the IVC.

Aged↗

Oral administration of bovine lactoferrin for treatment of tinea pedis. A placebo-controlled, double-blind study.

A clinical study was conducted to evaluate the effectiveness of lactoferrin, which is a protein component of cow's milk, in the treatment of tinea pedis. Doses of either 600 mg or 2000 mg of lactoferrin, or a placebo was orally administered daily for 8 weeks to 37 adults who were judged to have mild or moderate tinea pedis. Dermatological improvement and antifungal efficacy were assessed. In the analysis of all subjects, dermatological symptoms scores in all groups decreased but the differences were not statistically significant comparing the three groups. However, in the analysis limited to subjects with moderate vesicular or interdigital tinea pedis, dermatological symptoms scores in the lactoferrin-treated groups decreased significantly in comparison with the placebo group (P < 0.05). The organisms isolated were Trichophyton rubrum and Trichophyton mentagrophytes. A mycological cure was not seen in any of the subjects. In the 37 subjects there were no adverse events and no subject withdrew from the study because of an adverse event. These results suggest that orally administered lactoferrin can improve the dermatological symptoms in some subjects. The potential usefulness of lactoferrin as a functional food material for treating tinea pedis was seen for the first time in this study.

Administration, Oral↗

Value of laparoscopic microwave coagulation therapy for hepatocellular carcinoma in relation to tumor size and location.

BACKGROUND AND STUDY AIMS: The indications for laparoscopic microwave coagulation therapy (LMCT) for hepatocellular carcinoma (HCC) have not yet been adequately evaluated. This study investigated the value of LMCT in the treatment of HCC. PATIENTS AND METHODS: Forty-three patients with liver cirrhosis (including five patients in Child Pugh grade C), with 56 HCC lesions, were enrolled in the study. When dynamic computed tomography (CT) showed a loss in HCC enhancement characteristics and a low concentration area after LMCT, a lesion was judged to have undergone complete necrosis. RESULTS: The rate of complete necrosis for lesions measuring 40 mm or less was significantly higher (P<0.01) than for those measuring 41 mm or more. The rate of complete necrosis for lesions located on the liver surface, excluding those located close to the gallbladder or in contact with the diaphragm, was also significantly higher (P<0.01) than for those situated deep within the liver. The outcome for lesions of 40 mm or less was favorable. Intra-abdominal hemorrhage occurred in two patients, pneumothorax in three, and hepatic infarction in one, all associated with LMCT. However, these patients did not suffer any sequelae of clinical significance. CONCLUSIONS: This study suggests that there is a strong indication for LMCT for HCCs measuring 40 mm or less in diameter and those located on the liver surface even if they are as large as 50 mm, but not for those located close to the gallbladder or in contact with the diaphragm. LMCT appears to be applicable in patients with impaired liver function.

Aged↗

Lactoferrin given in food facilitates dermatophytosis cure in guinea pig models.

Dermatophytosis is the most common skin infection caused by dermatophytic fungi, such as Trichophyton spp. We studied the in vitro and in vivo antifungal effects of lactoferrin against Trichophyton. Human and bovine lactoferrin, and a bovine lactoferrin-derived peptide, lactoferricin B, showed in vitro antifungal activity that was dependent on the test strain and medium used. In guinea pigs infected on the back with Trichophyton mentagrophytes (i.e. those with tinea corporis), consecutive daily po administration of bovine lactoferrin did not prevent development of symptoms during the early phase of infection, but facilitated clinical improvement of skin lesions after the peak of the symptoms. The fungal burden in lesions was less in guinea pigs that had been given lactoferrin than in untreated controls 21 days after infection. In guinea pigs infected on the foot with T. mentagrophytes (i.e. those with tinea pedis), the fungal burden of the skin on the heel portion of the infected foot 35 days after infection was lower in animals fed lactoferrin than in controls. These results suggest the potential usefulness of lactoferrin as a food component for promoting dermatophytosis cure.

Administration, Oral↗

Beneficial effect of angiotensin-converting enzyme inhibitor on dilated cardiomyopathy induced by autoimmune mechanism against beta1-adrenoceptor.

We have shown that a peptide corresponding to the sequence of the second extracellular loop of the human beta1-adrenoceptor (beta1-peptide) was able to induce an autoimmune cardiomyopathy in rabbits. In this study, we examined the effect of angiotensin-converting enzyme inhibitor (ACEI) on beta1-peptide-induced cardiomyopathy. Rabbits were divided into four groups: (1) control group (n= 6) receiving saline injection; (2) beta1-peptide group (n = 8) immunized with beta1-peptide; (3) ACEI group (n = 6), lisinopril (3 mg/day) given orally and receiving saline injection; and (4) ACEI + beta1-peptide group (n = 7), lisinopril (3 mg/day) given orally and immunized with beta1-peptide. Our results showed that, after 1 year, all rabbits in the beta1-peptide group had an increase in heart weight, wall thinning and dilatations of both ventricles as compared with rabbits in the ACEI + beta1-peptide group that had normal heart weight and shape. All rabbits in the beta1-peptide group exhibited multifocal degeneration and necrosis of myocardial cells with moderate infiltration of inflammatory cells. In the ACEI + beta1-peptide group, three rabbits showed focal degeneration and necrosis of myocardial cells accompanied by mononuclear cells. The lesions in this group were apparently less marked than those in the beta1-peptide group. In conclusion, ACEI protects the myocardium from injury induced by an autoimmune mechanism against beta1-adrenoceptor.

Amino Acid Sequence↗

Pseudomonas plecoglossicida sp. nov., the causative agent of bacterial haemorrhagic ascites of ayu, Plecoglossus altivelis.

A new Pseudomonas species, for which the name Pseudomonas plecoglossicida is proposed, was isolated from cultured ayu (Plecoglossus altivelis) with bacterial haemorrhagic ascites. The causative agent was similar to Pseudomonas putida biovar A in its phenotypic characteristics and on the basis of 16S rRNA gene sequence analysis, but it reduced nitrate to nitrite. Furthermore, it was distinguished phenotypically from Pseudomonas putida biovar A by utilization of D-malate, L-(+)-tartrate, m-tartrate and nicotinate. The levels of DNA-DNA hybridization between the isolate strain FPC 951T and other reference strains of Pseudomonas species, including Pseudomonas putida, were less than 50%. The G+C content of the DNA of FPC 951T was 62.8 mol%. Strain FPC 951T (= ATCC 700383T) is designated the type strain of the new species.

Animals↗

Phylogenetic affiliation of the pseudomonads based on 16S rRNA sequence.

The broad and vague phenotypic definition allowed the genus Pseudomonas to become a dumping ground for incompletely characterized polarly flagellated, gram-negative, rod-shaped, aerobic bacteria, and a large number of species have been accommodated in the genus Pseudomonas. The 16S rRNA sequences of 128 valid and invalid Pseudomonas species, which included almost valid species of the genus Pseudomonas listed in the Approved Lists of Bacterial Names, were obtained: sequences of 59 species were determined and those of 69 species were obtained from the GenBank/EMBL/DDBJ databases. These sequences were compared with the sequences of other species of the Proteobacteria. Fifty-seven valid or invalid species including Pseudomonas aeruginosa (type species of the genus Pseudomonas Migula 1894) belonged to the genus Pseudomonas (sensu stricto). Seven subclusters were formed in the cluster of the genus Pseudomonas (sensu stricto), and the resulting clusters conformed well to the rRNA-DNA hybridization study by Palleroni (1984). The other species did not belong to the genus Pseudomonas (sensu stricto) and were related to other genera, which were placed in four subclasses of the Proteobacteria (alpha, beta, gamma and gamma-beta subclasses). Twenty-six examined species, which were not included in the cluster of the Pseudomonas (sensu stricto) and have not been transferred to other genera as yet, are listed alphabetically: 'Pseudomonas abikonensis', Pseudomonas antimicrobica, Pseudomonas beijerinckii, Pseudomonas beteli, Pseudomonas boreopolis, 'Pseudomonas butanovora', Pseudomonas carboxydohydrogena, Pseudomonas cissicola, Pseudomonas doudoroffii, Pseudomonas echinoides, Pseudomonas elongata, Pseudomonas flectens, Pseudomonas geniculata, Pseudomonas halophila, Pseudomonas hibiscicola, Pseudomonas huttiensis, Pseudomonas iners, Pseudomonas lanceolata, Pseudomonas lemoignei, Pseudomonas mephitica, Pseudomonas pictorum, Pseudomonas saccharophila, Pseudomonas spinosa, Pseudomonas stanier, Pseudomonas syzygii and Pseudomonas woodsii. The phylogenetic affiliations of these 26 pseudomonads species are shown.

Cloning, Molecular↗

Prevention of metastasis by a polyamine synthesis inhibitor in an animal bone metastasis model.

In order to better understand the development of skeletal metastases, we developed an appropriate animal model, as the natural progression of metastases in humans cannot be studied on the cellular level. In this study, we established a new animal model which developed bone metastasis in a bone grafted subcutaneously. C57BL/6 mice, which had received a bone (femur or tibia) transplanted in the dorsal subcutis, were injected with B16 melanoma cells into the left heart ventricle. Metastasis was found in approximately 70% of the extraskeletal bones. Using this model, the antimetastatic effect of a polyamine synthesis inhibitor was investigated. Inhibitors of the polyamine biosynthetic pathway have received considerable attention for their potential use in the treatment of cancer as they are responsible for the greatly increased production of the polyamines putrescine, spermidine, and spermine. A polyamine synthesis inhibitor, methylglyoxal-bis(cyclopentylamidinohydrazone) MGBCP, was investigated for its inhibitory effects on bone metastases. MGBCP (20 mg/kg) was administered intraperitoneally every day for 4 weeks and demonstrated strong inhibitory effects on bone metastases. MGBCP inhibited angiogenesis in the transplanted bone and the growth of B16 melanoma cells, thus suggesting a preventive mechanism in bone metastasis. No remarkable adverse effects of MGBCP were observed in any animal throughout the experimental period. Our results indicate that MGBCP has a strong potential for use as an anti-metastatic drug.

Animals↗

Indications for portal vein embolization combined with major hepatic resection for advanced-stage hepatocellular carcinomas. A preliminary clinical study.

BACKGROUND: Criteria for selection of patients for portal vein embolization (PVE) before major hepatectomy for advanced-stage hepatocellular carcinoma (HCC) have not been clarified in detail. This study was aimed at defining those benefiting from this therapy in a retrospective fashion. PATIENTS AND METHODS: Firstly, to determine liver functional criteria for applying this approach 26 patients with stage III (17 patients) or IV (9 patients) disease, who underwent major hepatectomies after PVE, were divided into those without major complications (20 patients) and a postoperative liver failure group (6 patients). Clinical, analytical, and hemodynamic parameters obtained before and after PVE were compared between the groups. Secondly, to define the application of this approach with regard to tumor progression survival rates of patients were also obtained, taking into account factors which affect tumor development, i.e. lesion size, intrahepatic metastasis and vascular invasion. RESULTS: With regard to liver function 4 nonindications were obtained: (1) a portal pressure measured right after PVE >25 cm H(2)O; (2) post-PVE serum hyaluronate >200 ng/ml; (3) pre-PVE serum cholinesterase <150 U/l; (4) post-PVE serum cholinesterase <150 U/l. In view of the tumor progression in patients with HCCs featuring intrahepatic metastasis spread to more than 3 segments (IM3) 1-, 3- and 5-year survival rates were low (42.9, 28.6 and 0%) with a statistical significance, compared to those in patients with intrahepatic metastasis limited in the same lobe (76.9, 46.2 and 24.6%). CONCLUSIONS: When laboratory data fulfill 3 or more of the criteria, the extent of hepatic resection may have to be carefully reconsidered. Patients with HCCs featuring IM3 intrahepatic metastasis may not benefit from the aggressive approach described here.

Adult↗

[Sensitive determination of vitamin K analogues in biological samples by high-performance liquid chromatography using platinum catalyst reduction and electrochemical detection].

To investigate the physiological roles of vitamin K analogues in bone metabolism, especially in osteoporosis, we have developed a sensitive and simple analysis system for vitamin K analogues in the serum and bone. After the separation of vitamin K analogues on a reversed-phase column, the analogues were reduced once in a platinum catalyst reduction column on-line and then monitored quantitatively by electrochemical detector (EICOM ECD-300) operated in the oxidation mode (+0.6 V vs. Ag/AgCl). The detection limits at a signal-to-noise ratio of 3 were 2-10 pg for vitamin K analogues. We also investigated the extraction procedures for the vitamin K analogues from serum and bone. Quantitative recoveries from serum and bone were obtained in the range of 80-101% for vitamin K analogues. We could determine both the circulating vitamin K levels in osteoporotic patients and the vitamin K contents in trabecular and cortical bone of osteoarthritis.

Animals↗

Attachment-inducing capacities of fish tissue extracts on oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae).

When oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae) were incubated in wells with lyophilized extracts of fish skin epithelia on the bottom, some attached to the well bottom with the haptor unfolded and shed the ciliated epidermal cells. Based on these morphological changes in oncomiracidia, we developed a new assay method to examine the attachment-inducing capacities of various fish extracts for oncomiracidia. Attachment-inducing capacities were found only in extracts of fish skin epithelium and not in other fish extracts. No significant difference in capacities was observed among extracts of skin epithelia of 4 fish species. Wheat germ lectin and concanavalin A suppressed capacities in extracts of skin epithelia of Japanese flounder and yellowtail, respectively. Suppressed capacities were recovered by adding sugars that bound specifically to these lectins. These results indicate that some sugar-related chemical substances that exist specifically in fish epithelium induce the attachment of N. girellae oncomiracidia.

Adhesiveness↗