Biomedical subjects

Y Kodera

Publications and source records attributed to Y Kodera.

333 records · Page 19Linked to original sources

PubMedDate not supplied

Lack of benefit of combined pancreaticosplenectomy in D2 resection for proximal-third gastric carcinoma.

Of the 2790 patients with gastric carcinoma who underwent surgery between January 1978 and December 1993, there were 224 who underwent a D2 resection for cancer of the proximal third of the stomach. Survival in these patients was retrospectively analyzed with special reference to the survival benefit of pancreaticosplenectomy (PS). The D2 resection involved a splenectomy in 129 patients, a PS in 38 patients, and neither in 57 patients, with 5-year survivals of 74%, 59%, and 91%, respectively. Although these differences in survival were attributable to the apparent deviation in the incidence of prognostic variables, no significant survival benefit of PS was observed for patients with the same clinical stage disease (stages II and III) or the same modal status (n1 and n2). Because PS was associated with a significant increase in the incidence of anastomotic dehiscence and length of hospital stay, the dismal survival benefit implies that it should not be performed routinely with the D2 resection but should be employed only for lesions with direct invasion of the pancreas.

Gastrectomy↗

PubMedDate not supplied

Hemin (Fe(3+))-- and heme (Fe(2+))--smectite conjugates as a model of hemoprotein based on spectrophotometry.

Hemin (Fe(3+)) was adsorbed onto synthetic smectite (clay mineral) in acetone to form a hemin-smectite conjugate. The hemin-smectite conjugate became soluble in water to form a transparent colloidal solution with a dark brown color. Its absorption spectrum in water showed a sharp Soret band at 398 nm with the molar extinction coefficient as epsilon(398nm) = 11.6 x 10(4) M(-1) cm(-1), which is in good agreement with epsilon(398nm) = (12.2 +/- 3) x 10(4) M(-1) cm(-1) of monomeric hematin (1). Hemin (Fe(3+))-smectite conjugate had a peroxidase-like activity in the presence of hydrogen peroxide (a hydrogen acceptor) and guaiacol (a hydrogen donor) in aqueous solution and its activity was higher than that of hematin. Hemin (Fe(3+))-smectite conjugate in water was reduced by adding sodium dithionite to form a heme (Fe(2+))-smectite conjugate which is also a transparent colloidal solution in water. Its absorption spectrum in aqueous solution was surprisingly in close agreement with that of oxyhemoglobin. Its peak positions of alpha, beta, and Soret bands were located in only a 9--3 nm shift to shorter wavelengths in comparison with those of oxyhemoglobin. Therefore, heme (Fe(2+))-smectite conjugate was bound to O(2) to form O(2)-heme (Fe(2+))-smectite conjugate. The addition of carbon monoxide, CO, to O(2)-heme (Fe(2+))-smectite conjugate caused the formation of CO-heme (Fe(2+))-smectite conjugate with a similar absorption spectrum of carboxyhemoglobin (HbCO) accompanied by shifting 8--10 nm to shorter wavelength. Therefore, the transformation of O(2)-heme (Fe(2+))-smectite conjugate to CO-heme (Fe(2+))-smectite conjugate was accompanied by shifting of 7, 4, and 3 nm to shorter wavelengths in the alpha, beta, and Soret bands respectively, which are similar to the spectral change from oxyhemoglobin to carboxyhemoglobin. Also the ratio (1:1.6) of the molar extinction coefficient of Soret band of O(2)-heme (Fe(2+))-smectite conjugate and CO-heme (Fe(2+))-smectite conjugate was surprisingly agreement with ratio (1:1.5) of oxyhemoglobin and carboxyhemoglobin. The phenomenon shown above was unexpectedly found during the course of study of bioconjugate of a bioactive substance, hemin (Fe(3+)) or heme (Fe(2+)), and a clay mineral, smectite, in place of the protein of globin in hemoglobin.

Gastrointestinal Agents↗

PubMedDate not supplied

Stabilization of L-asparaginase modified with comb-shaped poly(ethylene glycol) derivatives, in vivo and in vitro.

L-Asparaginase from Escherichia coli was coupled with two types of comb-shaped copolymer of poly-(ethylene glycol) derivative and maleic anhydride (activated PM), having molecular weights of 13,000 and 100,000 (activated PM13 and PM100, respectively) with multivalent reaction sites. After single intravenous injections of PM100-asparaginase and nonmodified asparaginase into rats, the enzymic activity of PM100-asparaginase in serum was well retained for at least 11 days, and the serum L-asparagine concentration remained undetectable for 27 days. The half-lives of PM100-asparaginase and nonmodified asparaginase were 50 and 1.5 h, respectively. Stabilization of L-asparaginase toward heat, urea, and acidity was caused by modifying the enzyme with activated PM13 and PM100. Especially, PM100-asparaginase retained high enzymic activity toward heat and urea, compared with PM13-asparaginase. It was suggested that these modifiers with a comb-shaped form and with multivalent reactive sites cover the whole surface of the asparaginase molecule and stabilize its conformation possibly through multiple covalent bindings and through various noncovalent interactions.

Animals↗

PubMedDate not supplied

Photostable chlorophyll a conjugated with poly(vinylpyrrolidone)-smectite catalyzes photoreduction and hydrogen gas evolution by visible light.

Chlorophyll a was adsorbed to a synthetic smectite intercalated by poly(vinylpyrrolidone) (PVP) to form the chlorophyll-PVP-smectite conjugate (Chl-PVP-SME) having an absorption maximum at 677 nm. The conjugate was found to be stable toward light illumination in comparison with chlorophyll-smectite, chlorophyll-PVP, and free chlorophyll a. Chl-PVP-SME had a photoinduced activity for catalyzing the reduction of methyl viologen. Furthermore, the evolution of hydrogen gas was observed when an aqueous suspension containing Chl-PVP-SME, methyl viologen (an electron carrier), 2-mercaptoethanol (an electron donor), and hydrogenase was illuminated by visible light.

Bacterial Proteins↗

PubMedDate not supplied

Hydrogen gas evolution and carbon dioxide fixation with visible light by chlorophyllin coupled with polyethylene glycol.

Chlorophyllin a was conjugated with alpha-(3-aminopropyl)-omega-methoxypoly(oxyethylene), PEG-NH(2), to form the PEG-chlorophyllin conjugate through acid-amide bonds. The PEG-chlorophyllin conjugate was stable toward light illumination under anaerobic condition in comparison with chlorophyllin a. The conjugate catalyzed the reduction of methyl viologen in the presence of 2-mercaptoethanol and the evolution of hydrogen gas in the presence of methyl viologen (an electron carrier), 2-mercaptoethanol (an electron donor) and hydrogenase (Scheme 1). Furthermore, the PEG-chlorophyllin conjugate catalyzed the photoreduction of NADP(+) or NAD(+) in the presence of ascorbate as an electron donor and ferredoxin-NADP(+) reductase as the coupling enzyme. Utilizing the reducing power of NADPH generated by the PEG-chlorophyllin conjugate under the illumination, CO(2) fixation was accomplished by the synthesis of malate (C(4)) from pyruvate (C(3)) and CO(2) in the presence of malic enzyme (Scheme 2). These reactions mentioned above did never proceed in dark or without each enzyme.

Anaerobiosis↗

PubMedDate not supplied

Feasibility study on protracted infusional 5-fluorouracil and consecutive low-dose cisplatin for advanced gastric cancer.

In this phase II trial 31 patients with advanced gastric cancer (21 with metastatic cancer and 10 with locally advanced cancer) were treated with a continuous 24-hour infusion of 5-fluorouracil (5-FU) 330 mg/m2/day plus low-dose cisplatin (CDDP) 6 mg/m2/day by bolus infusion on days 1-5. The regimen with a combination of 5-FU and low-dose CDDP (FLDP) was repeated weekly for two to four courses according to response and tolerance. In 24 (77%) of the 31 patients, four courses of this regimen were administered. The overall response rate was in 14/31 (45%) patients with measurable disease, including one complete response and 13 partial responses. An especially high response rate of 60% was seen in 10 patients with liver metastasis. Median survival time was 11 months (range 6-27+) in the 10 cases of locally advanced cancer and 11 months (range 6-24+) in the 21 cases of metastatic cancer. Toxicity was primarily hematologic. Leukopenia and thrombocytopenia of World Health Organization (WHO) grade 3 or 4 occurred in 4/31 (13%) and 4/31 (13%) of patients, respectively. Renal dysfunction, which is a major toxicity associated with CDDP, was not observed without hydration. The patients were able to eat during therapy and preserved a good quality of life. A randomized trial including the FLDP regimen is needed to compare it with other active regimens, particularly the use of high-dose CDDP.

Adult↗

PubMedDate not supplied

Cytomegalovirus-induced gastritis in a bone marrow transplant patient.

Cytomegalovirus (CMV)-induced interstitial pneumonitis is a well-known lethal complication in bone marrow recipients. CMV is also known to cause gastroenteritis. We report the first case of a bone marrow recipient who developed CMV-induced gastritis which is verified both histologically and virologically. The gastritis preceded the interstitial pneumonitis which was detected in an early stage and was successfully treated. We propose that bone marrow recipients who show signs and symptoms of gastritis undergo an endoscopic examination, and that biopsied specimens should be scrutinized for CMV by both histological examination and culture investigation.

Bone Marrow Transplantation↗

PubMedDate not supplied

Cytomegalovirus pneumonitis occurring after allogeneic bone marrow transplantation: a study of 106 recipients.

We have followed 106 recipients of allogeneic bone marrow transplantation (BMT), and observed 47 episodes of interstitial pneumonitis (IP) in 37 patients. Cytomegalovirus (CMV) pneumonitis was seen in 18 episodes in 18 patients, of whom 10 patients were diagnosed by bronchoalveolar lavage (BAL), 7 patients by autopsy, and 1 patient by sputum culture. There was one varicella-zoster virus pneumonitis diagnosed by autopsy. However, we could find no apparent etiology of pneumonitis in the other 18 patients. The median interval between BMT and episodes of IP was 74 days (range, 23-578 days) for CMV pneumonitis, and 180 days (range, 41-428 days) for idiopathic pneumonitis (p less than 0.05). BAL was more sensitive than transbronchial lung biopsy in the diagnosis of CMV pneumonitis, and CD4/CD8 ratio in BAL fluid was inverted in all episodes of CMV pneumonitis. Computed tomography (CT) scans were performed in 31 episodes in 26 patients, and all scans revealed abnormalities. CT scans were more sensitive than routine chest X-rays against micro- or small-nodular patterns, air bronchogram, and air alveologram (p less than 0.05). CT scan and arterial blood gas analysis were most useful and necessary in approaching the problem of pneumonitis in allogeneic marrow transplant patients. Based on these findings, when CMV pneumonitis is suspected, it is recommended to perform BAL for the final diagnosis of CMV pneumonitis.

Adolescent↗

PubMedDate not supplied

PAI-1 expression levels in esophageal and colorectal cancers are closely correlated to those in corresponding normal tissues.

To investigate the mechanism of PAI-1 overexpression in esophageal and colorectal cancers, PAI-1 expression levels in these cancers were compared to those in corresponding normal tissues. Quantitative RT-PCR was performed for the PAI-1 gene in esophageal and colorectal cancer tissues and in the corresponding normal tissues and the association between PAI-1 expression levels in these tissues was evaluated. There was a significant correlation between esophageal and colorectal cancer and the corresponding normal PAI-1 expressions with a Spearman's rank correlation coefficient of 0.77 (p < 0.0001) and 0.81 (p < 0.0001), respectively. In previous studies, PAI-1 overexpression was found to be significantly associated with the malignancy of esophageal and colorectal cancers. Taken together, PAI-1 overexpression in esophageal and colorectal cancers might originate from higher PAI-1 expression in corresponding normal tissues and result in a malignant phenotype of these cancers.

Aged↗