Biomedical subjects

H Yasuda

Publications and source records attributed to H Yasuda.

At least 289 records · Page 16Linked to original sources

PubMed1996

[Prospective randomized trial comparing 1/2 FAM (5-fluorouracil (5-FU) + adriamycin + mitomycin C) versus palliative therapy for the treatment of unresectable pancreatic and biliary tract carcinomas (the 2nd trial in non-resectable patients). Japanese Study Group of Surgical Adjuvant Therapy for Carcinomas of the Pancreas and Biliary Tract].

The efficacy of 1/2 FAM, which consists of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC), was compared with that of palliative treatment in patients with unresectable pancreatic and biliary tract carcinomas in a multicenter randomized trial. The patients assigned to 1/2 FAM group were treated with 5-FU 200 mg/m2/day IV, ADM 15 mg/m2/day IV and MMC 5 mg/m2/day IV. These 3 drugs were given concurrently as the initial dose within a week after palliative operation, and this regimen was repeated for at least 2 whole courses, at 4-week intervals before the next course of therapy. Those randomized to the control group were subjected to palliative treatment alone. Completely eligible for analysis were 42 cases of the 1/2 FAM group and 41 of the control group. There was no significant difference between the groups with respect to the overall and differentiated survival times according to the tumor sites and the clinical efficacy. As for the duration of 50% inhibition of tumor progression, a significantly better outcome was obtained in 1/2 FAM group. Tumor progression was most significantly inhibited in patients with gallbladder carcinoma. In 1/2 FAM group, tumor reduction was achieved in 1 CR and 2 PR patients. The most frequent adverse reaction was gastrointestinal manifestations, along with diarrhea and alopecia. 1/2 FAM did not contribute to the life prolongation, but inhibited the tumor progression for a significantly longer duration and, to a lesser extent, reduced the tumor size in unresectable pancreatic and biliary tract carcinomas. This regimen is suggested to be useful particularly in the treatment of the latter carcinoma.

Adult↗

PubMed1996

[Treatment of advanced gastric carcinoma based on histologic type].

It is well known that clinicopathological characteristics in gastric carcinoma are different according to its histologic type, intestinal type or diffuse type. Multivariate analysis of advanced gastric carcinoma revealed that the histologic type significantly related to the type of recurrence, hematogenous metastasis or peritoneal dissemination. Therefore, we introduced a prospective randomized trial for treatment of advanced gastric carcinoma based on histologic type of carcinoma. Intraoperatively, 10 mg of mitomycin C was given via portal system in the intestinal type and given in peritoneal cavity in the diffuse type. As results, in the intestinal type, survival rate in patients with the chemotherapy was longer than that without the chemotherapy, but this did not reach to a significant difference. On the contrary, in the diffuse type, patients with the chemotherapy showed a significant longer survival rate compared to those without the chemotherapy. These results suggests the availability of treatment based on histologic type of carcinoma. Much more selective and effective improvements in this type of treatment will be required.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

[Usefulness of percutaneous transluminal angioplasty of lesions in saphenous vein graft].

The purpose of this study is to evaluate the potential efficacy of saphenous vein graft (SVG) angioplasty. Angioplasty of 64 lesions in SVG was performed in 32 patients. (balloon angioplasty for 59 lesions and directional atherectomy for 5 lesions). The angioplasty site involved the proximal vein graft including aortic anastomosis in 9 lesions, the midportion of the graft in 32 lesions, and the distal anastomotic site in 17 lesions. Six grafts were totally occluded. The overall initial success rate was 89%, and restenosis rate was 57%. The initial success rate was lower in occluded grafts (75%) than in proximal (89%), midportion (94%), or distal lesions (88%). There were similar trend for restenosis (proximal 67%, midportion 50%, distal 56%, occluded 75%). The initial success rate was higher in vein graft < 1 year old compared with graft 1 to 5 years or > 5 years after operation (100% versus 87%, 82% respectively). The restenosis rate did not depend on graft age (< 1 year 53%, 1 to 5 years 75%, > 5 years 50%). There was no procedural death or emergent operation. Distal embolization occurred in two cases, both of which underwent directional atherectomy. Angioplasty of a non occlusive obstruction in saphenous vein graft had an initial success rate of approximately 90% and is a safe procedure. Angioplasty of chronic total occlusion was associated with poor acute result. Although the induced high restenosis rate remains a significant problem, angioplasty of saphenous vein graft is a reasonable alternative to revasculization.

Aged↗

PubMed1996

Reconstitution of recombinant bovine A1 adenosine receptors in Sf9 cell membranes with recombinant G proteins of defined composition.

We investigated the coupling of A1 adenosine receptors to recombinant G proteins. Recombinant baculoviruses were used to express bovine A1 adenosine receptors in Sf9 insect cells that lack endogenous adenosine receptors. Binding parameters for recombinant receptors expressed in Sf9 cell membranes using the antagonist radioligand [125I]BW-A844U ([125I]8-cyclopentyl-3-iodoaminophenethyl-1-propylxanthine) are Bmax = 2-5 pmol/mg of protein and K(D) = 0.53 +/- 0.12 nM. In competition assays, the potency order of agonists is (R)-phenylisopropyladenosine > (S)-phenylisopropyladenosine > 5'-N-ethylcarboxamidoadenosine, properties characteristic of native bovine A1 adenosine receptors. The agonist radioligand 125I-N6-4-aminobenzyladenosine binds to two affinity states of the recombinant A1 adenosine receptors with K(D) values of 0.09 and 10.4 nM. The high affinity binding site represents <10% of total sites and is increased 7-fold on reconstitution with both alpha and betagamma G protein subunits but not with either subunit alone; thus, exogenous alpha and betagamma subunits do not functionally interact with endogenous Sf9 betagamma and alpha subunits, respectively. Four different alpha subunits (alpha i1, alpha i2, alpha i3, and alpha o) and six different beta gamma subunits (beta1gamma1, beta1gamma2, beta1gamma3, beta2gamma2, beta2gamma3, and bovine brain betagamma)) increased GTP-sensitive, high affinity agonist binding. The results indicate that bovine A1 adenosine receptors couple equally well to G protein alpha i and alpha o subunits in combination with betagamma subunits containing the beta1 or beta2 subunits and gamma2 or gamma3 subunits. G protein heterotrimers that contain the beta1gamma1 dimer couple with similar potency but reduced efficacy to A1 adenosine receptors.

Animals↗

PubMed1996

[Staged repair for bilateral ductus arteriosus with pulmonary atresia and non-confluent pulmonary artery--a case report].

Staged operation was successfully performed in an infant with bilateral ductus arteriosus, and absence pulmonary artery. The first stage operation was performed at 2 months old of age. The left pulmonary artery was reconstructed using an equine pericardial roll sized 10 mm in diameter, and a 5 mm Dacron graft was anastomosed between the left subclavian artery and the roll as an aortopulmonary shunt. In the second stage, the same procedure was done on the right side at eight months of age. In the last stage, the patient underwent Rastelli procedure at 2 years old of age. The central pulmonary artery was created with a ring forced EPTFE graft above the ascending aorta, and a Carpentier-Edwards valved conduit (14 mm) was anastomosed between the right ventricle and the EPTFE graft. Post operative course was uneventful. We consider that the staged procedure including the pulmonary artery reconstruction and the aortopulmonary shunt on both sides is recommended in the case of absent central pulmonary artery in infant.

Blood Vessel Prosthesis↗

PubMed1996

[A case report of multiple pseudoaneurysms of the left ventricle following acute myocardial infarction].

Multiple pseudoaneurysms of the left ventricle following acute myocardial infarction were successfully repaired in a 50-year-old man. Three days after onset of acute myocardial infarction, we electively performed PTCA on the right coronary artery which was completely occluded at the proximal segment. One month after PTCA, the left ventriculogram revealed multiple pseudoaneurysms of the left ventricle. Primary closure of orifices of the pseudoaneurysms was performed using pledgeted mattress sutures under cardiopulmonary bypass. Histology of aneurysm confirmed the diagnosis of pseudoaneurysm.

Aneurysm, False↗

PubMed1995

A role for phosphorylation in the proteolytic processing of the human NF-kappa B1 precursor.

A precursor, p105, for one of the subunits (p50) of the NF-kappa B transcription factor, plays an important role in inducible expression of diverse cellular genes. p105 also functions as a cytoplasmic inhibitor for NF-kappa B, and the proteolytic processing of its inhibitory C-terminal region is required for generation of active NF-kappa B. Here, it is reported that the human p105 C-terminal region is phosphorylated in vivo on Ser894 and Ser908, which are potential phosphorylation sites in vitro for proline-directed serine/threonine kinases such as cyclin-dependent kinase. Furthermore, the mutation of these in vivo phosphorylation sites retards p105 processing in vivo, suggesting that p105 processing is regulated in a phosphorylation-dependent manner.

Amino Acid Sequence↗

PubMed1995

Hepatic damage induced by perfusion of radical generating azo compound and its inhibition by vitamin E.

The damaging effect of perfusion of hydrophilic radical generating azo compound on the liver of normal and vitamin E-deficient rats and its inhibition by antioxidants were studied in order to increase understanding of the action of free radicals on biological tissues. The hepatic damage was evaluated from the release of cytosolic enzymes such as glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, mitochondrial oxidation metabolism and morphological change. Two kinds of hydrophilic azo compounds were used, one which decomposes spontaneously at a uniform rate to generate free radicals and the other which does not. The former induced hepatic damage in a dose-dependent manner, while the latter did not exert any damage. Both endogenous vitamin E in the membranes and a water soluble vitamin E analogue added simultaneously with a radical initiator suppressed the hepatic damage. These results show that the hepatic damage induced by perfusion of radical generating azo compound is caused not by the azo compound itself but by free radicals.

Alanine Transaminase↗

PubMed1995

Selective expression of the tba-1 alpha tubulin gene in a set of mechanosensory and motor neurons during the development of Caenorhabditis elegans.

In the nematode Caenorhabditis elegans, a monoclonal antibody 3A5 raised against Drosophila alpha tubulins selectively stains the nervous system immuno-cytochemically. Direct screening of a C. elegans cDNA expression library with 3A5 has allowed cloning of the tba-1 (tubulin alpha-1) gene from C. elegans. The corresponding genomic DNA encodes a protein of 449 amino acid residues that has a high homology with the vertebrate alpha tubulins but a lower homology with yeast alpha tubulins. Interestingly, the carboxyl-terminus sequence EEEGEEY (Glu-Glu-Glu-Gly-Glu-Glu-Tyr) of the nematode tba-1 encoded isotype is identical to these residues in human, mouse, rat, pig and chicken alpha-1 tubulin isotypes that are expressed in the brain. Temporal and spatial expression studies of the tba-1 gene using Northern blot analysis and tba-1::lacZ fusion gene expression analysis during embryonic and the postembryonic development of C. elegans reveal that the tba-1 tubulin is preferentially expressed in the nematode nervous system, especially in a set of mechanosensory neurons and a set of ventral cord motor neurons (DA, DB, VA, and VB) during embryonic and postembryonic development. Our results indicate an inter-species conservation of the alpha tubulin carboxyl-terminal domain in functionally related brain specific isotypes from metazoans as divergent as mammals and nematodes. These results also suggest specificity of the individual alpha tubulin isotypes during neural development.

Amino Acid Sequence↗

PubMed1995

Production of activin A and follistatin in cultured rat vascular smooth muscle cells.

Activin A, a member of the transforming growth factor beta supergene family, modulates DNA synthesis in cultured rat vascular smooth muscle cells (VSMC) (Kopma et al. (1993) Exp. Cell. Res. 206, 152-156). In the present study, we studied the production of activin A and follistatin in VSMC. When VSMCs cultured in a 24-well plate were cultured with 10% fetal calf serum (FCS) for 24 h, 0.94 +/- 0.20 pmol/well (mean +/- SE, n = 6) of bioactive activin was released into the culture media. Reverse-transcription polymerase chain-reaction revealed the expression of mRNA for the beta A subunit of inhibin but not for either the beta B or alpha subunit. Bioactivity of activin was increased in quiescent cells treated with FCS or platelet-derived growth factor (PDGF) but not with angiotensin II (Ang II) or insulin-like growth factor-I (IGF-I). Ang II or IGF-I did not stimulate DNA synthesis by itself but, when these two agents were combined, they increased nuclear labeling by 16.4% and release of bioactive activin by 170% of basal. The dose-response relationship and time course study indicated that PDGF-mediated release of activin correlated with initiation of DNA synthesis. Steady state expression of mRNA for the beta A subunit was markedly elevated 12 h after the addition of PDGF and was reduced thereafter. To assess the significance of autocrine activin, the effect of PDGF was determined in the presence and absence of excess of exogenous follistatin. The PDGF-mediated DNA synthesis was enhanced by the addition of excess follistatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Activins↗

PubMed1995

Antibodies against GM1 ganglioside affect K+ and Na+ currents in isolated rat myelinated nerve fibers.

High titers of anti-GM1 ganglioside antibodies (anti-GM1 antibodies) may be implicated in lower motor neuron disease. We studied the pathogenic role of anti-GM1 antibody using the petroleum jelly-gap voltage clamp technique on isolated single myelinated rat nerve fibers. Anti-GM1 antisera were obtained from rabbits immunized with GM1 ganglioside. Extracellularly applied anti-GM1 antisera without complement activity increased both the rate of rise and the amplitude of the K+ current elicited by step depolarization, with little effect on Na+ current. In the presence of active complement, however, anti-GM1 antibodies decreased the Na+ current, and caused a progressive increase of nonspecific leakage current. Neither complement alone nor complement-supplemented antisera from which anti-GM1 antibodies were depleted by affinity chromatography had any effect on ionic current. These observations indicate that anti-GM1 antibodies themselves can uncover K+ channels in the paranodal region, while anti-GM1 antibodies bound to the nodal membrane in the presence of complement may form antibody-complement complexes that block Na+ channels and disrupt the membrane at the node of Ranvier.

Action Potentials↗

PubMed1995

Mouse p87wee1 kinase is regulated by M-phase specific phosphorylation.

We have cloned a mouse wee1 kinase cDNA (mwee1). The clone is 2258 bp in length and its open reading frame corresponds to 646 amino acid residues. The molecular weight of this kinase is 87 kDa in SDS-PAGE, which is about 1.7-fold larger than the human p50wee1 kinase reported previously. In a cell cycle, the mouse wee1 kinase is phosphorylated at M-phase, and an in vitro study using a mitotic extract revealed that phosphorylation occurs in the N-terminal domain, which is absent from the human wee1 kinase, resulting in inactivation of the kinase activity. The N-terminal domain or entire molecule is extensively phosphorylated by cdc2-cyclin B kinase. Furthermore, the activity of the wee1 kinase was reduced by phosphorylation with the mitotic extract which contained cdc2-cyclin B kinase.

Amino Acid Sequence↗

PubMed1995

A single intraportal administration of follistatin accelerates liver regeneration in partially hepatectomized rats.

BACKGROUND/AIMS: Activin A is an autocrine negative regulator of DNA synthesis in rat hepatocytes and is expressed in remnant liver after partial hepatectomy. To determine the role of activin A in liver regeneration, the effects of exogenous follistatin, which blocks the action of activin A, were examined. METHODS: Human recombinant follistatin was infused into the portal vein immediately after 70% hepatectomy. Changes in body weight, remnant liver weight, liver regeneration rate, and nuclear bromodeoxyuridine labeling were measured. RESULTS: In control rats, nuclear labeling was observed at 24 hours and peaked at 36 hours after the hepatectomy. In follistatin-treated rats, nuclear labeling was first observed after 18 hours and was significantly (P < 0.05) greater than that in control rats at 24 hours. In follistatin-treated rats, both remnant liver weight and liver regeneration rate were significantly greater at 120 hours. Serum concentrations of albumin and glucose remained reduced for up to 120 hours in control rats but recovered in follistatin-treated rats. CONCLUSIONS: A single administration of follistatin accelerates the initial round of DNA synthesis after partial hepatectomy. Activin A produced in remnant liver may exert tonic inhibitory effect on liver regeneration. Follistatin may be useful as a potential therapeutic agent to promote liver regeneration.

Activins↗

PubMed1995

Eucalyptone from Eucalyptus globulus.

A new cariostatic compound named eucalyptone was isolated from the leaves of Eucalyptus globulus. The structure of this compound was elucidated by spectroscopic methods.

Anti-Bacterial Agents↗

PubMed1995

A search for prognostic factors in cancer of the pancreatic head: the significance of the DNA ploidy pattern.

Using flow cytometry after the nuclear isolation and staining of tissue specimens, the significance of the DNA ploidy pattern as a prognostic factor in cancers of the head of the pancreas has been evaluated in 33 patients who underwent a pancreatic cancer resection. In addition to the DNA ploidy pattern, the size of the tumour, regional lymph node involvement, the tumour's histopathological grade and the results of a curative resection were also evaluated as prognostic factors. The results of a univariate analysis revealed that the survival rate was significantly higher for patients with a diploid tumour (n = 20) than for patients with an aneuploid tumour (n = 13) (P < 0.001). Furthermore, survival rates were significantly better for patients with a T1 tumour than with a T2 or T3 tumour (P < 0.001), for patients without positive lymph node involvement than for those with positive lymph nodes (P < 0.001), for patients with well-differentiated adenocarcinomas (G1) than for those with moderately differentiated (G2) or poorly differentiated (G3) adenocarcinomas, and for patients who underwent a curative resection than for those who underwent a non-curative resection (P < 0.005). A multivariate analysis revealed significant prognostic differences in the DNA ploidy pattern (P < 0.001), the frequency of a curative resection (P < 0.001), regional lymph node involvement (P < 0.05), and in the tumour's histopathological grading (P < 0.05) but not its size. This study has found the DNA ploidy pattern to be the most significant prognostic factor (chi 2 value: 38.1).

Adenocarcinoma↗

PubMed1995

Prey density effect on cannibalism by Toxorhynchites towadensis (Diptera: Culicidae).

The effect of prey density on cannibalism by the larvae of Toxorhynchites towadensis (Matsumura) was studied in the laboratory. Frequency of cannibalism was compared among pairs of all possible instar combinations of Tx. towadensis in the presence and absence of Aedes albopictus (Skuse). Cannibalism occurred despite the presence of prey larvae, but more frequently between different instars than the same instars. Cannibalized larvae were always younger than or the same age as their attackers. Six predatory larvae were reared in a container with 30, 60, or 120 prey throughout their development, and cannibalism and development were observed. No cannibalism was observed when prey density was 120. However, in the continuous presence of 30 prey, cannibalism occurred on 8 occasions. Cannibalism at a prey density of 60 was intermediate in frequency. Most (92%) cannibalism occurred when 1st or 2nd instars attacked the same or younger instars. The time in cohabitation of different instars was shorter with increasing prey density.

Aedes↗

PubMed1995

The effect of lansoprazole treatment on the healing and relapse of peptic ulcer and serum levels of IgG anti-Helicobacter pylori antibody.

In the present study, the effects of short-term treatment with lansoprazole on healing and recurrence of peptic ulcer were investigated. Complete healing (change to the S2 stage) after 3 or 4 weeks of treatment with lansoprazole was observed in 9.9% of gastric ulcers and 38.3% of duodenal ulcers. Complete healing was observed after 3 or 4 weeks of treatment with lansoprazole in gastric ulcers and was significantly related to the serum titer of IgG anti-Helicobacter pylori antibodies. This was not the case in duodenal ulcers. Complete healing after 6 or 8 weeks of treatment with lansoprazole was not dependent on serum levels of IgG anti-H. pylori antibodies. Short-term treatment by lansoprazole did not affect serum levels of IgG anti-H. pylori antibodies immediately after the end of lansoprazole treatment, but significantly reduced serum levels of IgG anti-H. pylori antibodies were found 9 months after treatment.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

Pancreatic enzyme activity after a pylorus-preserving pancreaticoduodenectomy reconstructed with pancreaticogastrostomy.

This study was initiated to clarify whether the main hydrolytic enzymes of the pancreas are activated or inactivated when secreted into the stomach of patients who had undergone a pylorus-preserving pancreaticoduodenectomy (PPPD) and were given a pancreaticogastrostomy (PG) for the reconstruction. Seventeen such patients, 15 cancer patients and two pancreatic patients, who underwent PPPD-PG reconstruction were postoperatively followed up for 3 or more years to investigate the influence of the gastric acid on the p-type amylase and lipase activity. Results revealed that when the pH was < 3.0, both the p-type amylase and the lipase secretion remained inactivated, but when the pH was > 3.1, the activity of both enzymes increased proportionately. The pancreatic enzyme activity in the small intestine was also investigated in seven patients, six cancer cases and one case of pancreatitis, given a PPPD-PG reconstruction, and it was found that the pancreatic enzyme activity in the small intestine increased after milk loading. Further, the fecal pancreatic enzyme activity was investigated in 17 patients given a PPPD-PG reconstruction. Results reveal that the fecal p-type amylase, lipase, and chymotrypsin activity amounted to 21, 27, and 31% of the respective values seen in 10 healthy volunteers. However, the fecal pancreatic enzyme activity levels did not differ significantly from the levels seen in 20 pancreaticoduodenectomy patients given a pancreaticojejunostomy reconstruction. In conclusion, it was found that the main hydrolytic enzymes of the pancreas are activated when the gastric acidity is over pH 3.1, which normally occurs after ingestion of a meal.

Amylases↗