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Biomedical subjects

H Murayama

Publications and source records attributed to H Murayama.

At least 73 records · Page 4Linked to original sources
PubMed1996

Effect of the eradication of Helicobacter pylori on duodenal ulcer healing and ulcer relapse: randomized controlled study in Japan.

To investigate the effect of the eradication of Helicobacter pylori on the healing and relapse of duodenal ulcers. 50 patients with active duodenal ulcer and H. pylori infection were randomly allocated to two treatment groups. One group (cimetidine group) received cimetidine 400 mg twice daily for 6 weeks and the other group (double-therapy group) received 300 mg amoxicillin granules and 250 mg metronidazole thrice daily for 2 weeks, in addition to the same regimen of cimetidine as the cimetidine group. Forty-two patients completed the study. After confirmation of ulcer scar, all patients were followed up for 6 months while receiving treatment with teprenone, an agent that does not affect acid secretion or the eradication of H. pylori. The healing rates at 6 weeks were 90% in the cimetidine group and 95.5% in the double-therapy group. H. pylori eradication occurred in 0% of the cimetidine group and in 73.7% of the double-therapy group (P = 0.004). The cumulative relapse rates in the two groups at 6 months were 64.3% and 11.1%, respectively (P = 0.0007). In the double-therapy group, the cumulative relapse rate at 6 months in the patients in whom H. pylori persisted was 50% (2/4); the rate was 0% (0/14) in the patients in whom H. pylori had been eradicated (P = 0.005). Histological gastritis significantly improved compared with the baseline in the double-therapy group, but no such improvement was seen in the cimetidine group. White scarring was found in 7.1% of the cimetidine group and in 83.3% of the double-therapy group after 6 months (P < 0.0001). The eradication of H. pylori markedly decreased the relapse rate in duodenal ulcer patients, and it significantly improved both the grade of gastritis and the quality of the ulcer scar.

Adult↗
PubMed1996

Apoptosis and proliferation in gastric carcinoma: the association with histological type.

We examined apoptosis in 33 gastric carcinomas using the terminal deoxynucleotydil transferase mediated dUTP-digoxigenin nick end labelling technique (TUNEL). Of the tumours, nine were well-differentiated, 13 moderately differentiated and 11 poorly differentiated. In addition, we also analysed MIB-1, a cell proliferation antigen. Morphologically, apoptotic tumour cells were more frequently observed in well-differentiated tumours. In addition, apoptotic signals of the TUNEL method were seen even in the nuclei of tumour cells which did not show apoptosis. The nick end labelling index was 51.0 +/- 26.3 in the well-differentiated and moderately differentiated tumours and 28.0 +/- 18.8 in poorly differentiated tumours. The mean of apoptotic body index and nick end labelling index were both significantly higher in well-differentiated and moderately differentiated tumours than in the poorly differentiated type (P < 0.0001, P = 0.008). The MIB-1 labelling index and higher in poorly differentiated tumours than in the well-differentiated or moderately differentiated tumours, and labelled cells were more numerous in the superficial region than in the middle and deep regions of tumours. No apparent correlation was found between the nick end labelling index and the MIB-1 labelling index. The high number of apoptotic cells (the high Nick end labelling index) and low proliferation potentiality (the low MIB-1 labelling index) in well-differentiated gastric carcinomas may thus be related to their natural tendency to demonstrate slow growth.

Adenocarcinoma↗
PubMed1996

Modeling of continuously and directly analyzed biphasic reaction courses of ribulose 1,5-bisphosphate carboxylase/oxygenase.

This paper aims at clarifying the cause of the time-dependent, partial loss of the activity during reaction (so-called fallover) of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from plant sources. This was done by comparing the reaction courses calculated using the reaction models constructed here based on the present conflicting two ideas on fallover with directly measured courses obtained with RuBisCO purified from spinach leaves. Since the ordinary methods with 14CO2 and indicator enzymes were not adequate for analyzing the progress of fallover, we followed the reaction by measuring the change of the light absorbance of ribulose 1,5-bisphosphate (RuBP) at 280 nm. Direct measurements of the reaction course showed that RuBisCO lost its activity with a rate constant of 6.1 to 6.5 x 10(-3) s-1 at both 0.5 and 2 mM RuBP. The rate constant of the recovery of the enzyme to show the original fallover was determined as 1.2 to 1.3 x 10(-3) s-1 with RuBisCO that had just experienced fallover. These constants were used in the models. Calculation with a model assuming the binding of xylulose 1,5-bisphosphate (XuBP) to the catalytic sites of the enzyme as the cause of fallover and using the reported dissociation constant of XuBP in the binding and the reported rate of the formation of XuBP from RuBP gave a rather linear reaction course. The minimum requirements for the model to be valid were that the rate of XuBP formation was more than once for every 600 turnovers, the dissociation constant of XuBP for the catalytic sites was less than 0.1 nM, and the binding of XuBP to the sites showed a strong negative cooperativity. Inclusion of non-catalytic RuBP-binding sites in the model was essential to elucidate the course at higher RuBP concentrations. The model constructed assuming that hysteresis was the cause of fallover could calculate the measured reaction courses for the initial 20 min of reaction of both 0.5 and 2mM RuBP. The rate constants of the hysteretic conformational changes of the predicted enzyme forms to others were given. The direct measurement of the long-term reaction course revealed the two phases in the decay of the activity; fast decay for the initial several minutes and subsequent slow decrease. Although the fast decay could be predicted by the hysteresis model, the slower one required the participation of inhibition by XuBP. We reasoned from these results and the reported characteristics of the binding of other sugar phosphates to the catalytic sites that the initial fast decay of the activity in fallover was due to the hysteretic property of the enzyme and the slower phase of fallover was due to the inhibition of XuBP.

Kinetics↗
PubMed1996

Pancreatic calculi superimposed upon slow growing pancreatic cancer.

We report on a 59 year old male patient with cancer of the head of the pancreas, upon which pancreatic calculi were superimposed during the 3 year clinical course. Pancreatic calculi were noted in the main pancreatic duct (MPD) on both computed tomographic scans and ultrasonographs of the abdomen approximately 10 months after the recognizable dilatation of the MPD. Existence of the calculi was confirmed by autopsy. Elemental analysis and infrared spectrophotometry of the calculi demonstrated that the main constituent of the calculi was calcium carbonate. Histopathological examination showed that the pancreatic cancer was moderately differentiated adenocarcinoma. Immunohistochemical studies revealed that pancreatic stone protein (lithostathine) was present in the cytoplasm of tumour cells. In this case, pancreatic cancer progressed to obstruct the MPD unusually slowly, resulting in stagnation of pancreatic secretion and subsequent formation of the calculi.

Adenocarcinoma↗
PubMed1996

[Comparison between retrograde cerebral perfusion and selective cerebral perfusion by intraoperative electroencepharogram].

We used retrograde cerebral perfusion (RCP) to protect the brain in patients undergoing aortic arch replacement from May 1991 to July 1992. Subsequently, we have been using selective cerebral perfusion (SCP). In this study, a group of six patients undergoing RPC were compared with 5 patients undergoing SCP with regard to the intraoperative electroencepharogram (EEG) and post operative clinical course. There were no deaths in either group, but transient palsy of the right arm developed in one patient in the RCP group. The amplitude of intraoperative EEG was examined at four points: before cardiopulmonary bypass, during RCP or SCP, at 30 degrees C and at 35 degrees C during rewarming. The EEG amplitude at these four points was expressed as a ratio to the value before cardiopulmonary bypass. The ratios at these four points were 1, 0, 0.08, and 0.19 in the RCP group and 1, 0, 0.70, and 0.90 in the SCP group, respectively. In the SCP group, EEG recovered rapidly, whereas in the RCP group EEG did not recover until the completion of cardiopulmonary bypass in all but one patient. These results indicated that RCP does not provide reliable protection of the brain.

Adult↗
PubMed1996

[A case report of mediastinitis due to methicillin resistant Staphylococcus aureus after total aortic arch replacement].

A 78-year-old man underwent total aortic arch replacement for ruptured aortic arch aneurysm. Two weeks after the surgery, high fever and leucocytosis developed. He was placed on a regimen of antibiotics. However, mediastinitis eventually ensued five weeks later with the pus draining from the sternotomy wound. The culture revealed a Methicillin resistant staphylococcus aureus. The infected tissue was debrided from the mediastinal cavity 40 days postoperatively. The cavity was kept open and was intermittently irrigated with 2% Providone-iodine for three days. Subsequently, an omental graft was placed. The infection successfully subsided gradually and the patient has been well for a year and a half after the initial surgery. The procedure is considered to be extremely effective for the management of a drastic infection involving thoracic aortic prosthesis.

Aged↗
PubMed1996

[An operative case of bilateral partial anomalous pulmonary venous return using a direct anastomosis between the right atrial appendage and the superior vena cava].

We have experienced a case of bilateral partial anomalous pulmonary venous return without atrial septal defect. Right upper pulmonary vein returned to the superior vena cava and left upper pulmonary vein returned to the left brachiocephalic vein. This type of bilateral partial anomalous pulmonary venous return was extremely rare, and only 4 such cases have been reported in the Japanese literature. The patient, aged 3 years and 11 months, was successfully operated on, using a direct anastomosis between the right atrial appendage and the superior vena cava. This procedure is considered to be advantageous because both this right atriotomy line and suture line avoid injury of the sinus node and the sinuatrial node artery and no foreign material is used. A decrease in postoperative arrhythmia can also be expected from this procedure.

Anastomosis, Surgical↗
PubMed1996

Does gallstone formation after open cardiac surgery result only from latent hemolysis by replaced valves?

OBJECTIVES: To clarify the relationship between open heart surgery and gallstone formation. METHODS: Fifty-one patients without gallstones (Group A) underwent cardiac surgery using a heart-lung machine and were followed for 24 months by ultrasonography. Blood tests of hemolysis markers were examined before, immediately after, and 3, 6, and 12 months after surgery. And 52 healthy candidates without gallstone (Group B) also were followed for 24 months. RESULTS: The cumulative gallstone incidence in Group A was 15.7% at 3 months after surgery, 23.9% at 6 months, and 30.4% at and beyond 12 months and was significantly higher than that of Group B (p < 0.01). The stones showed a high dense pattern, indicative of pigment stones, in eight of the 10 patients assessed by CT. With respect to the type of surgery, latent hemolysis was seen only in patients who underwent mechanical valve replacement. However, there were no significant differences in the gallstone incidence between the patients who underwent mechanical valve replacement and those who underwent another cardiac surgery. The values of hemoglobin, haptoglobin, and lactate dehydrogenase showed abnormal values immediately after surgery, regardless of mechanical valve replacement or another cardiac surgery. CONCLUSIONS: The use of a heart-lung machine, which produces hemolysis, appears to have a close relation to gallstone formation after open cardiac surgery.

Cardiac Surgical Procedures↗
PubMed1995

Isolation and characterization of a Photosystem II complex from the red alga Cyanidium caldarium: association of cytochrome c-550 and a 12 kDa protein with the complex.

A Photosystem II (PS II) complex was purified from an acidophilic as well as a thermophilic red alga, Cyanidium caldarium. The purified PS II complex was essentially devoid of phycobiliproteins and other contaminating components, and showed a high oxygen-evolving activity of 2375 mumol O2/mg Chl per h using phenyl-p-benzoquinone as the electron acceptor. The expression of this high activity did not require addition of exogenous Ca2+, although EDTA reduced the activity by 40%. This effect of EDTA can be reversed not only by Ca2+ but also by Mg2+; a similar Mg2+ effect has been observed in purified cyanobacterial PS II but not in higher plant PS II. Immunoblotting analysis indicated the presence of major intrinsic polypeptides commonly found in PS II from cyanobacteria and higher plants as well as the extrinsic 33 kDa protein. Antibodies against the extrinsic 23 and 17 kDa proteins of higher plant PS II, however, did not crossreact with any polypeptides in the purified PS II, indicating the absence of these proteins in the red alga. In contrast, two other extrinsic proteins of 17 and 12 kDa were present in the red algal PS II; they were released by 1 M Tris or Urea/NaCl treatment but not by 1 M NaCl. The 17 kDa polypeptide was identified to be cytochrome c-550 from heme-staining, immunoblot analysis and N-terminal amino acid sequencing, and the 12 kDa protein was found to be homologous to the 12 kDa extrinsic protein of cyanobacterial PS II from its N-terminal sequence. These results indicate that PS II from the red alga is closely related to PS II from cyanobacteria rather than to that from higher plants, and that the replacement of PS II extrinsic cytochrome c-550 and the 12 kDa protein by the extrinsic 23 and 17 kDa proteins occurred during evolution from red algae to green algae and higher plants.

Amino Acid Sequence↗