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Biomedical subjects

H Wakabayashi

Publications and source records attributed to H Wakabayashi.

At least 73 records · Page 4Linked to original sources
PubMed1998

Modified hepatoduodenal ligamentectomy for advanced carcinoma of the biliary tract: the importance of preservation of the replaced left hepatic artery.

Hepatoduodenal ligamentectomy (ligamentectomy) is the ultimate surgery for biliary tract carcinoma involving perioperative difficulties such as total hepatic ischemia during revascularization of the hepatic artery and the portal vein, patency of the reconstructed hepatic artery, and high incidence of related operative mortality. In the present study, modified ligamentectomies with extended right hepatic lobectomy, including resection of the caudate lobe, were performed on three patients with advanced biliary tract carcinoma in whom the left hepatic artery had been replaced and the original artery was preserved. In all patients, postoperative courses were uneventful: success of the resection was confirmed by histological examination. This procedure enabled en bloc resection of hepatoduodenal ligament with positive cancer invasion to take place. It was carried out safely without concern for the difficulties described above. In our view, ligamentectomy should be performed in all such cases.

Aged↗
PubMed1998

Treatment of recurrent hepatocellular carcinoma by hepatectomy with right and middle hepatic vein reconstruction using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion: report of a case.

We report herein the case of a patient who had previously undergone a lateral segmentectomy for hepatocellular carcinoma (HCC) in whom recurrent HCC invading the trunk of the right and middle hepatic veins in a damaged liver was treated by reconstruction of both hepatic veins, using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion. Reconstruction was performed using a graft taken from the left external iliac vein and divided into two pieces. Hepatic ischemia lasted for 91 min during the procedure and the intrahepatic temperature, as monitored by inserting a needle-type thermometer, was decreased to 11 degrees C throughout the procedure. The peak levels of serum glutamic pyruvic transaminase, lactate dehydrogenase, and total bilirubin were 363 IU/l, 1198 IU/ml, and 2.8 mg/dl, respectively, on postoperative day (POD) 2. The patient's postoperative course was uneventful except for mild, temporary swelling of the left leg. Postoperative computed tomography and magnetic resonance imaging examinations disclosed no obstruction of either graft, and the patient was discharged on POD 40.

Carcinoma, Hepatocellular↗
PubMed1998

Effect of Helicobacter pylori infection on gastric mucosal phospholipid contents and their fatty acid composition.

To investigate the effect of Helicobacter pylori infection on the 'gastric mucosal barrier', phospholipid contents and the fatty acid composition of endoscopic biopsy specimens of the gastric mucosa were analysed in healthy volunteers with and without H. pylori infection. The gastric corporeal phosphatidylcholine (PC) content of H. pylori-positive healthy volunteers was less than that of H. pylori-negative healthy volunteers (P < 0.05). Moreover, H. pylori-positive healthy volunteers had a decrease in linoleic acid composition (P < 0.0001) and an increase in arachidonic acid composition (P < 0.0001) and in the arachidonic acid/linoleic acid ratio (P < 0.0001) of antral and corporeal PC compared with H. pylori-negative healthy volunteers. These findings suggest that H. pylori infection enhances production of various eicosanoids, resulting in changes in the gastric mucosal phospholipid contents and their fatty acid composition, that may consequently cause the gastric mucosal barrier to be weakened.

Adult↗
PubMed1998

Inhibition of hyphal growth of azole-resistant strains of Candida albicans by triazole antifungal agents in the presence of lactoferrin-related compounds.

The effects of bovine lactoferrin (LF) or the LF-derived antimicrobial peptide lactoferricin B (LFcin B) on the growth of Candida albicans hyphae, including those of three azole-resistant strains, were investigated by a crystal violet staining method. The hyphae of two highly azole-resistant strains were more susceptible to inhibition by LF or LFcin B than the azole-susceptible strains tested. One moderately azole-resistant strain was defective in the formation of hyphae and showed a susceptibility to LF greater than that of the susceptible strains but a susceptibility to LFcin B similar to that of the susceptible strains. The highly azole-resistant strain TIMM3317 showed trailing growth in the presence of fluconazole or itraconazole, while the extent of growth was reduced by the addition of LF or LFcin B at a sub-MIC. Thus, the addition of LF or LFcin B at a sub-MIC resulted in a substantial decrease in the MICs of fluconazole and itraconazole for two highly azole-resistant strains; e.g., the MIC of fluconazole for TIMM3317 was shifted from > 256 to 0.25 micrograms/ml by LF, but the MICs were not decreased for the susceptible strains. The combination effects observed with triazoles and LF-related compounds in the case of the two highly azole-resistant strains were confirmed to be synergistic by the fractional inhibitory concentration index. These results demonstrate that for some azole-resistant C. albicans strains, LF-related compounds combined with triazoles can inhibit the growth of hyphae, an important form of this organism in pathogenesis.

Antifungal Agents↗
PubMed1998

Human chymase, an enzyme forming novel bioactive 31-amino acid length endothelins.

We report the novel role of human chymase in the production of bioactive 31-amino acid length endothelins (ETs), which may play a role in allergies and vascular diseases. In the bronchi of asthmatic patients, the vascular tissue in atherosclerosis, and the heart muscle in cardiac hypertrophy, both ET-like immunoreactivity and the accumulation of mast cells significantly increase. Chymase from human mast cells selectively cleaves big ET-1, -2 and -3 at their Tyr31-Gly32 bonds, and produces novel bioactive 31-amino acid length ETs, ETs(1-31), without any further degradation products. However, chymases from other species, human cathepsin G, and porcine alpha-chymotrypsin, degrade big ETs. ETs(1-31) at concentrations between 10(-9) M and 10(-7) M exhibited various contractile potencies in rat tracheae and porcine coronary arteries in a dose-dependent manner. Furthermore, ET-1(1-31) at concentrations between 10(-14) M and 10(-10) M caused a significant increase in the intracellular free Ca2+ concentration. The contractile activity of ETs(1-31) may not be the consequence of conversion to the corresponding ETs(1-21) by phosphoramidon-sensitive ET converting enzyme(s) or other chymotrypsin-type proteases and metallo-endopeptidases, because the contractile activity was not significantly inhibited on treatment with inhibitors of these proteases prior to the addition of ET-1(1-31).

Animals↗
PubMed1998

Fatty acid composition and arachidonate metabolites in the livers of ethanol-treated rats fed an arachidonate-supplemented diet: effect of dietary fat.

The effects of 1% arachidonic acid ethyl ester (AA) administration on the liver prostanoid metabolites and on serum and liver lipids in 3 g/kg ethanol-administered rats fed 10% lard or corn oil were studied. The rats were divided into 6 groups: lard-sucrose (Lard-Suc); lard-ethanol without AA (Lard-Et); lard-ethanol with AA (Lard-EtAA); corn oil-sucrose (Corn-Suc); corn oil-ethanol without AA (Corn-Et); and corn oil-ethanol with AA (Corn-EtAA). Liver triglyceride increased in Corn-EtAA compared with Corn-Et. Arachidonic acid (20: 4n-6) levels in liver phospholipid were significantly decreased in Corn-Et, but elevated in Lard-Et. The levels of 20:4n-6 were significantly increased with AA administration in both ethanol groups. Liver 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) in Corn-Suc (24.7 +/- 5.1 pg/mg protein) was markedly higher than in Lard-Suc (4.5 +/- 1.2 pg/mg protein), and the 6-keto-PGF1 alpha lowered significantly with the addition of ethanol (9.3 +/- 0.9 pg/mg protein), but it increased with AA administration (21.6 +/- 4.9 pg/mg protein). In Lard-EtAA, a significant increase in 6-keto-PGF1 alpha was observed compared with Lard-Suc. The liver leukotriene B4 (LTB4) level in Lard-Suc was significantly lower than that of Corn-Suc. In the corn oil group, ethanol feeding was associated with a significant increase in liver LTB4. AA administration to Corn-Et suppressed the elevated LTB4. Serum thiobarbituric acid-reactive substance (TBARS) concentrations in the corn oil group were higher than in the lard group, and these concentrations were not altered by AA administration. From these results, we concluded that the administration of AA in rats treated with ethanol increased 20:4n-6 in liver phospholipid and liver PGI2 levels, irrespective of dietary fat, and may protect against alcoholic liver injury. AA with a diet rich in linoleic acid (18:2n-6), however, may increase fat in the alcoholic liver.

Alanine Transaminase↗
PubMed1998

Involvement of apoptosis and cyclin D1 gene repression in growth inhibition of T-47D human breast cancer cells by methylglyoxal bis(cyclopentylamidinohydrazone).

Polyamines are considered to be important intracellular molecules for the proliferation of the cancer cells. In this study, effects of methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), a potent inhibitor of the polyamine biosynthetic pathway, on the growth and cell cycle of T-47D human breast cancer cells were investigated. MGBCP dose-dependently inhibited the growth of T-47D cells, in which the contents of spermine, spermidine and putrescine decreased concomitantly. The gene expression of cyclin D1 was also repressed by the MGBCP treatment. The MGBCP-treated cells clearly exhibited morphological changes indicating the blebbing and chromatin condensation which are characteristic of apoptosis. Flow cytometric analysis showed hypo-diploid subpopulations due to apoptotic cells, and characteristic oligonucleosomal-sized DNA fragments were clearly observed for MGBCP-treated cells as the concentration of the drug was increased. These findings suggest that the inhibition of polyamine synthesis results in the repressions of cyclin D1 expression and cell cycle progression, eventually inducing apoptosis in these human breast cancer cells.

Antineoplastic Agents↗
PubMed1998

Respiratory burst assay of head kidney macrophages of ayu, Plecoglossus altivelis, stimulated with Glugea plecoglossi (Protozoa: Microspora) spores.

The respiratory burst assay was conducted using the nitroblue tetrazolium reduction method and horseradish peroxidase method to investigate the events when ayu head kidney macrophages phagocytize fresh and formalin-killed Glugea plecoglossi spores. The production of O2 against G. plecoglossi spores was negligible compared to zymosan (P < 0.01). Zymosan-induced O2 production was markedly inhibited by adding G. plecoglossi spores simultaneously (P < 0.01). This phenomenon was dose dependent, and killed spores were less inhibitory than fresh spores. The production of H2O2 was drastically increased when G. plecoglossi spores were added (P < 0.01), and most spores were phagocytized. From these results, it is suggested that G. plecoglossi spores modulate the host's phagocytic response to establish infection.

Animals↗
PubMed1998

Nine patients with hepatocellular carcinoma surviving for more than six years after treatment, including two patients who have survived without recurrence after hepatic lobectomy.

Of patients treated for hepatocellular carcinoma (HCC) accompanied by liver cirrhosis at our University Hospital between 1985 and 1990, clinical background factors in nine patients (7.0% of all patients) who survived for more than six years were examined to clarify the conditions that facilitate long-term survival. In particular, we describe two cases among these patients who have survived without the recurrence of a liver tumor for more than six years after hepatic lobectomy. In eight of nine patients, surgery was performed as the initial treatment. In seven patients, HCC was solitary and there was no portal invasion. Six patients were evaluated as Stage I according to clinical staging. Furthermore, the two patients without recurrence after treatment have been taking immunostimulators since their initial treatment until the present. The above observations suggest that surgical treatment should be considered in patients in whom hepatic reserve capacity is well maintained despite a tumor size greater than 2 cm. Subsequent recurrence should be detected earlier, and percutaneous ethanol injection therapy (PEIT) with a focus on maintaining liver function should be repeated. In addition, multi-disciplinary treatment including medication with immunostimulators is beneficial.

Aged↗
PubMed1997

Selective conversion of big endothelins to tracheal smooth muscle-constricting 31-amino acid-length endothelins by chymase from human mast cells.

Chymase from human mast cells selectively cleaved big endothelins (ETs) at the Tyr31-Gly32 bond and produced novel trachea-constricting 31-amino acid-length endothelins, ETs(1-31), without any further degradation products. Chymases from other species, such as the enzymes from rat connective tissue and mucosal mast cells, and the other chymotrypsin-like proteases examined degraded big ETs. ETs(1-31) exhibited various contractile potencies as to the rat trachea in comparison with 21-amino acid-length endothelins, ETs(1-21), and big ETs: ET-1(1-21) > ET-1(1-31) > big ET-1; ET-2(1-31) > ET-2(1-21) > or = big ET-2; ET-3(1-21) > or = ET-3(1-31) > or = big ET-3. Among the ETs(1-31), ET-2(1-31) was the most potent constrictor, its potency being similar to that of ET-1(1-21) and stronger than that of ET-2(1-21). The contractile activity of ETs(1-31) may not be the consequence of conversion to the corresponding ETs(1-21) by phosphoramidon-sensitive ET-converting enzymes or other chymotrypsin-type proteases and metalloendopeptidases, because the contractile activity was not inhibited significantly on treatment with inhibitors of these proteases before the addition of ET-1(1-31). Inhibitors of chymotrypsin-type serine proteases, on the contrary, significantly enhanced the contractile activity exhibited by ET-1(1-31) and big ET-1, but not that by ET-1(1-21). These results suggest that protease(s) on the surface of the rat trachea tends to degrade ETs(1-31) and big ETs, and thereby reduces their contractile activity. Taken together, the results suggest that trachea-constricting ETs(1-31) generated by human chymase may play a role in the hyper-responsive airway in allergic inflammation.

Animals↗
PubMed1997

Effect of preoperative portal vein embolization on major hepatectomy for advanced-stage hepatocellular carcinomas in injured livers: a preliminary report.

With the aim of minimizing postoperative liver dysfunction and promoting increased resectability, we employed portal vein embolization (PVE). In this study, the effect of PVE on major hepatic resection for advanced-stage hepatocellular carcinoma (HCC) in injured livers was evaluated. PVE was performed prior to hepatectomy in 13 patients with stage III and IV HCCs. Following PVE, right trisegmentectomy was performed in 3 patients, extended right lobectomy in 3 and right lobectomy in 7. To evaluate the effect of PVE, the changes in liver functional capacity and estimated remnant liver volume (ERLV), determined by computed tomography, were examined before and after PVE. The operative morbility, mortality, and survival rates after hepatectomy were also assessed. By 2 weeks after PVE, ERLV had increased in all patients, by an average of 28%, and the mean resection rates had decreased from 70.0% to 62.2%. Postoperatively, the 30-day mortality rate was 15.3%, and the 1- and 2-year survival rates were 69% and 46%, respectively. The results of this study indicate that resectability can be increased, and major hepatectomy can be made safer by employing PVE preoperatively, in view of the fact that major hepatectomy was not considered feasible without PVE in these patients.

Aged↗
PubMed1997

Hepatic protein synthesis in the regenerating rat liver after hepatopancreatectomy.

To evaluate the effects of hepatopancreatectomy on the regenerative process of the liver, the serum protein changes, hepatic protein synthesis (HPS), and bromodeoxyuridine (BrdU) labeling index were measured in rats. Sprague-Dawley rats were divided into four groups according to the type of resection: A simple laparotomy was performed in the sham group; 68% of the liver was excised in the Hx group; 45% of the pancreas was excised in the Px group; and 45% of the pancreas and 68% of the liver were excised simultaneously in the HPx group. Serum total protein and albumin levels were significantly lower in the HPx group compared to the other three groups on postoperative day (POD) 3 (P < 0.05). HPS was markedly increased in the Hx and HPx groups. In the Hx group, it was significantly higher, peaking on POD 2, compared to the HPx group (P < 0.05), while in the HPx group, it was significantly higher compared to the Hx group (P < 0.05), peaking on POD 3. The BrdU labeling index, as a marker of DNA synthesis, was significantly suppressed in the HPx group on POD 1 compared to the Hx group (P < 0.05). Thus, compared to hepatectomy alone, hepatopancreatectomy suppresses DNA synthesis, causing a delay in the increase of protein synthesis in the regenerating liver, resulting in a more marked decrease in the serum protein level.

Alanine Transaminase↗
PubMed1997

Effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems in rat liver microsomes.

The effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems with respect to three cytochrome P-450 isozymes in rat liver microsomes were investigated. FK-506 non-competitively inhibited the aniline p-hydroxylase, p-nitroanisole O-demethylase and lidocaine N-deethylase activities of cytochrome P-450-linked monooxygenase systems, these activities being mainly catalyzed by cytochromes P-450 CYP2E1, CYP2C11 and CYP3A4, respectively, and the Ki values of the activities for FK-506 were determined to be 605, 491 and 97 microM, respectively. The inhibition of cytochrome P-450-linked monooxygenase systems by FK-506 seemed to involve the direct inhibition of cytochromes P-450 because the NADPH-cytochrome c reductase and NADPH-ferricyanide reductase activities of NADPH-cytochrome P-450 reductase were not affected by the presence of 1 mM FK-506 at all. A spectrophotometric study showed that a reverse type I spectral change was induced on the addition of FK-506 to rat liver microsomes, and the Ks value was apparently 125 microM. On the other hand, the EPR spectra of cytochromes P-450 in rat liver microsomes were not affected by 1 mM FK-506. These results suggest direct interaction between FK-506 and cytochrome P-450 apoproteins, except for the heme iron regions of cytochromes P-450, resulting in inhibition of the drug-metabolism activities catalyzed by cytochromes P-450.

Aniline Hydroxylase↗
PubMed1997

Case report: interferon induced coma in Sheehan's syndrome.

A 54-year-old woman who was being treated with 10 million units (mu) of natural interferon (IFN)-alpha per day for chronic active hepatitis C at a local clinic, developed coma on the fourth day of treatment. On admission to Yamagata University Hospital, she was still in a state of semicoma with severe hyponatraemia (122 mEq/L) and hypochloraemia (89 mEq/L). After the administration of electrolytes, her condition improved remarkably. Endocrinological loading tests showed a hypofunction of the anterior pituitary gland. In consideration of these results, and her past experiences of haemorrhage during childbirth and subsequent amenorrhoea, we diagnosed her illness as a coma as a result of Sheehan's syndrome which had become overt during IFN therapy. She recovered completely after treatment with hydrocortisone and l-thyroxine.

Adrenocorticotropic Hormone↗
PubMed1997

Abnormality in fatty acid composition of gastric mucosal phospholipids in patients with liver cirrhosis and its correction with a polyunsaturated fatty acid-enriched soft oil capsule.

The abnormal composition of the fatty acids in gastric mucosal phospholipids was examined in 11 patients with non-alcoholic liver cirrhosis accompanied by gastritis and in 10 healthy subjects without liver disease and gastritis. The cases positive for serum anti-Helicobacter pylori immunoglobulin G antibody were excluded. The arachidonic acid (AA, C20:4n-6) contents of the two main components of phospholipid, the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) fractions, in gastric biopsy specimens were significantly lower in the cirrhosis group, although PC and PE contents in gastric biopsy specimens were not altered. In the cirrhosis group, AA contents of the PC fractions in gastric biopsy specimens were significantly correlated with AA contents of plasma PC fractions and serum albumin levels. Soft oil capsules containing polyunsaturated fatty acid (PUFA) such as AA, eicosapentanoic acid (EPA, C20:5n-3) and docosahexanoic acid (DHA, C20:6n-3) were administered after each meal daily for 4 weeks to six cirrhotic patients and four control subjects, who were randomly selected from the patients and control subjects. After administration of PUFA-enriched oil capsules, gastric mucosal AA contents of PC and PE fractions were significantly improved almost to the control levels. In three cirrhotic patients with severe or mild gastritis whose gastric mucosal lesions were endoscopically shown to have responded to PUFA-enriched oil capsules, AA contents of plasma PC and PE fractions before administration were much lower than in the remaining three cirrhotics that did not respond to the PUFA-enriched oil capsules, but significantly improved to the control levels after administration of oil capsules. The results demonstrate that administration of PUFA-enriched soft oil capsules increased AA contents of the phospholipids in gastric mucosa and thus improved gastric mucosal lesions endoscopically in cirrhotic patients with gastritis.

Adult↗
PubMed1997

Augmented inhibition of growth of Candida albicans by neutrophils in the presence of lactoferrin.

The combined inhibitory effects of neutrophils and lactoferrins on the growth of Candida albicans were examined. Murine or human neutrophils partially inhibited growth of C. albicans when cultured with C. albicans in vitro. The growth inhibition was augmented by a combination of neutrophils and more than 30 microg/ml of bovine lactoferrin or 1 microg/ml of human lactoferrin, concentrations less than 1/10-1/200 their inhibiting concentrations when used alone. The inhibition of C. albicans was also enhanced by combination of neutrophils and bovine apolactoferrin or iron-bound holo-lactoferrin, but not by transferrin. Combination effects of neutrophils and lactoferrin were also observed in a condition where there was no contact between neutrophils and Candida cells. These results suggest that neutrophils inhibit the growth of C. albicans regardless of whether there is direct contact between them and Candida cells: neutrophil growth inhibition effects were augmented in the presence of a physiological concentration of lactoferrin, perhaps through some action of lactoferrin other than chelation of ferric ion.

Animals↗
PubMed1997

Effect of laser treatment on the root canal of human teeth.

The purpose of this study was to examine the morphological and temperature changes of the apical portion of human extracted teeth treated by Nd: YAG, CO2 and Argon-lasers. Seventy-two single-rooted human teeth were studied. The root canals were prepared conventionally. Laser treatment of the apical portion of the canal was carried out by means of an optic fiber or metal tip. Temperatures were recorded thermographically. Two-thirds of the specimens were stained with black India ink and 36% silver ammonium fluoride solution. All specimens were irradiated by the three types of lasers at several intensities and the temperatures were recorded. Half of the specimens were prepared for the telescopic light microscope and for scanning electron microscopic observation, and the rest for histopathological examination by light microscope. The scanning electron microscopic evaluation showed that the laser energy vaporized the deposited debris, producing a glaze-like surface. The histopathological investigation revealed a tapered, enlarged apical lased area. All three laser devices were capable of vaporizing the debris in this way but the degree of morphological change was highly dependent on energy level and duration. The Argon-laser produced the highest temperatures.

Argon↗