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Biomedical subjects

A Oishi

Publications and source records attributed to A Oishi.

At least 19 recordsLinked to original sources
PubMed2001

The effect of nitric oxide production by sinusoidal endothelial cells on preservation injury during cold ischemia.

Multifactorial elements are responsible for preservation and reperfusion injury in liver allografts. Sinusoidal endothelial cells (SECs) are a primary target of cold preservation injury of the liver. We examined the correlation between nitric oxide (NO) production by SECs and their injury during cold preservation. SECs were isolated from rat livers and preserved in either Euro-Collins (EC) or University of Wisconsin (UW) solution. Injury to the SECs was more severe when preserved in the EC solution than in the UW solution during cold ischemia. In addition, NO production by SECs was found to be proportionate to the cell injury. Cell viability was not improved by the addition of NO inhibitor, L-NMMA. Further, NO inhibitor was detrimental to the SECs in a 24-h preservation in UW solution. LDH release by SECs preserved in UW solution supplemented with L-NMMA was 11.10+/-2.03 IU/l, while that in UW solution alone was 3.70+/-0.70 IU/l (P<0.01). Together, our results suggest that NO protects SECs during cold preservation and that NO from SECs may have beneficial effects on the liver during cold ischemia.

Journal Article↗
PubMed2001

[Myoglobinuria].

Explore the source record for details and available documents.

Alcoholism↗
PubMed2000

Crystal structure and preferred conformation of beta-lactams derived from (S)-1-arylethyl isocyanates and vinyl ethers.

The configurational analysis of beta-lactams prepared from [2 + 2] cycloaddition of vinyl ethers to pure enantiomers of 1-arylethyl isocyanates was carried out by high resolution 1H NMR. The addition of a chiral shift reagent revealed that the most important conformation of the studied beta-lactams in solution is that in which the methine proton, of the exocyclic stereogenic carbon, points towards the carbonyl oxygen atom. Since the configuration of the stereogenic exocyclic carbon is known, the orientation of the aromatic ring allows the correlation of the chemical shifts with the absolute configuration of the new stereogenic centers. This method is particularly useful to establish the stereochemistry of oily beta-lactams having the N-(1-arylethyl) group. The X-ray crystallographic analysis carried out with (1R,5S)-7-[(1S)-1-(1-naphthyl) ethyl]-2-oxa-7-azabicyclo[3.2.0]heptan-6-one, is consistent with the proposed model for beta-lactams in solution.

Crystallography, X-Ray↗
PubMed1999

Enhancement of enzyme reaction of magnetically anisotropic polyacrylamide gel rods immobilized with ferromagnetic powder and beta-D-galactosidase in an alternating magnetic field.

An immobilized polyacrylamide gel containing beta-D-galactosidase and Sr-Ba-ferrite was magnetized in a static magnetic field. The gel rods (10 mm long, O 2 mm) exhibiting magnetic anisotropy could move at lower than 100 Hz but not at higher than 250 Hz in an alternating magnetic field of 200 Oe. In case of immovability of gel rods, the apparent enzymic activity increased 3 times higher under exposure of an alternating magnetic field of 500 Oe (570 Hz). It could be explained that the ferromagnetic powder inside the gel might vibrate under the influence of elasticity of gel in the alternating magnetic field of 100 or 500 Oe and 0.2-12 kHz. This might facilitate faster diffusion of the substance inside the gel and transportation of the substrate and the product through the surface of gel. Consequently, the enzyme reaction was apparently activated.

Acrylic Resins↗
PubMed1999

Placenta accreta/increta. Review of 10 cases and a case report.

A review of the patients seen at the Department of Obstetrics at Dokkyo University Hospital who had suffered placenta accreta/increta in the past 18 years, was performed. There were 10 such cases out of 9,716 deliveries during this period. This incidence is higher than that which has been reported in other Western countries. Forty percent of the patients in our study had placenta accreta/increta accompanied by placenta previa or low lying; 30% had had a prior cesarean section (C/S); 70% had previously experienced dilatation and curettage (D & C); 80% had previously undergone a C/S and/or D & C: and 40% had a history of miscarriage. Three of the ten patients with placenta accreta/increta required a hysterectomy; 2 patients were successfully treated with hemostatic stitches on the endometrium; and the remaining 5 mild cases were treated with removal of the placenta, either manually or with the use of forceps. There was no case of maternal death. In 2 cases, neonatal asphyxia was noted, but the neonate immediately recovered.

Adult↗
PubMed1999

Experimental hypocalcemia induced by hemodialysis in goats.

To evaluate whether hemodialysis with a dialysate containing no calcium (Ca-free HD) can induce hypocalcemia and restore the clinical signs and blood biochemical changes in naturally occurred hypocalcemic disorder in ruminants, the clinical signs and the changes in plasma electrolytes and minerals concentrations were observed in goats during 6-hr hemodialysis. The four goats received hemodialysis with the dialysate containing calcium (Ca HD), and 10 days later they had Ca-free HD. The plasma ionized Ca (Ca++) and total Ca (TCa) concentrations were not affected by Ca HD, whereas the levels significantly decreased during whole period of Ca-free HD. The Ca++ and TCa concentrations were 0.69+/-0.06 mmol/l and 5.9+/-0.3 mg/dl at 6 hr of Ca-free HD, respectively. The clinical signs observed during Ca-free HD seemed to resemble to those in naturally occurred hypocalcemic cases that were reported previously. Therefore, Ca-free HD was suggested to be one of the possible methods to induce experimental hypocalcemia in ruminants.

Animals↗
PubMed1996

Racial factors cannot explain superior Japanese outcomes in stomach cancer.

OBJECTIVE: To compare the stage-stratified survival of Japanese patients treated in Honolulu according to Western techniques with that of Japanese patients treated in Tokyo according to Japanese techniques, thus eliminating race as a potentially confounding variable. DESIGN AND PATIENTS: Of 312 Honolulu Japanese patients surviving Western-type gastric resection for neoplasm between 1974 and 1985, 279 were identified with invasive gastric adenocarcinoma unassociated with any second malignancy. This Honolulu cohort, treated by Western methods, was retrospectively compared with a similar, previously described cohort of 3176 Tokyo Japanese patients treated according to Japanese methods. MAIN OUTCOME MEASURES: American Joint Committee on Cancer/Union Internationale Contre le Cancer criteria for stage-stratified survival. RESULTS: Despite non-TNM prognostic factors favoring higher survival for the Honolulu Japanese patients, for every TNM stage, we observed higher survival for the Tokyo Japanese patients who were treated according to Japanese techniques. For stage I disease, the survival rates were 86% vs 96%, respectively (P < .001); for state II, 69% vas 77% (P = .15); for stage III, 21% vs 49% (P < .001); and for stage IV, 4% vs 14% (P < .001). CONCLUSIONS: Because all patients in this study are Japanese, race-related factors or the "different-disease" hypothesis cannot explain these results. Lymphadenectomy-related stage-migration and/or differing therapeutic efficacy seem more likely explanations.

Adenocarcinoma↗
PubMed1996

Radiographical evaluation of bone maturation in Japanese black beef cattle.

Epiphyseal ossification in the radius, ulna, metacarpus, proximal phalanx and tuber calcaneus was examined radiographically in Japanese Black beef cattle. The grade of standard ossification was assessed monthly for each epiphysis. Bone maturations could be divided into 8 grades for the distal radius and distal ulna, 7 grades for the distal metacarpus, 5 grades for the proximal phalanx, and 8 grades for the tuber calcaneus, respectively. The closure of the epiphyseal line completed at the earliest (12-14 months of age) on the proximal phalanx, and at the latest (35-37 months of age) on the distal ulna. Changes in gradings were steep at 0 to 5 months of age but became almost constant after 10 months of age in all the epiphyses. There were no significant differences in bone maturation between the cattle with different sex and breeding conditions.

Aging↗
PubMed1995

Canine plasma erythropoietin levels in 124 cases of anemia.

Erythropoietin (EPO) levels in plasma from 124 clinically anemic dogs were determined by in vivo bioassay. In 81 anemic dogs with normal renal function, the concentration of plasma EPO showed a close correlation with the hemoglobin concentration. The plasma EPO level was obviously decreased in 43 anemic dogs with renal failure. Of these dogs with renal failure, 17 showed no detectable plasma EPO and resulted in the death of these dogs. In the remaining 26 dogs having detectable plasma EPO, the plasma concentration rate of EPO related to blood urea nitrogen and serum creatinine values.

Anemia↗
PubMed1995

Preventive effects of recombinant human erythropoietin administration on anemia associated with repeated hemodialysis in nephrectomized dogs.

The preventive effects of recombinant human erythropoietin (rhEPO) administration on progression of anemia were evaluated during hemodialysis in nephrectomized dogs. In control dogs given no rhEPO, anemia gradually progressed with repeated hemodialysis and with little erythropoietic response observed in the bone marrow. In dogs administered with rhEPO, however, an active erythropoietic response was induced in the bone marrow, indicating that anemia due to hemodialysis was being prevented.

Anemia↗
PubMed1993

Evaluation of phlebotomy-induced erythropoietin production in the dog.

Erythropoietin (EPO) production in dogs was studied by reducing red blood cells with phlebotomy. In this study, the hemoglobin reduction rate (delta %Hb) was newly taken into account as the regulating factor for EPO production, and its usefulness to estimate the stimulating intensity to EPO production was examined. As the result, plasma EPO was highly correlated with delta %Hb showing the importance related to regulation of EPO production, in the increasing plasma EPO by different degrees of phlebotomy, in the change of plasma EPO through the anemia progress and recovery period after severe phlebotomy, and in the initial variation of plasma EPO induced by chronic mild phlebotomy. On the other hand, increasing EPO production appeared at least within 6 hr after acute severe phlebotomy, which revealed significantly higher plasma level compared with the mild chronic phlebotomy, suggesting the effect of time leading to red blood cell reduction on EPO production response. Simultaneously, considering an in vivo EPO half life of 8.4 hr calculated from plasma EPO disappearance after bilateral nephrectomy, endogenous plasma EPO accumulation should be taken into consideration in rapidly increasing of delta %Hb.

Anemia↗
PubMed1993

Evaluation of erythropoietin production in dogs with reduced functional renal tissue.

This study was designed to determine the quantity of functional renal tissue needed to maintain homeostasis of red blood cell production by evaluating the erythropoietin (EPO) production response to phlebotomic stimulation in the 1/2- and 1/4-kidney dogs surgically prepared. The results showed that the reduction in functional renal tissue caused a decrease in EPO production, which led to the delay in recovery from anemia. In the anemic progress stage, the plasma EPO level showed a transition proportional to the quantity of functional renal tissue immediately after the operation for tissue reduction. The 1/2-kidney dog group still kept such proportional relation even in the recovery stage. Thus, the half of the normal renal tissue was considered sufficiently contributory to EPO production needed to maintain homeostasis of red blood cell production. However, the 1/4-kidney dog group precipitously decreased in plasma EPO level in the recovery stage and fell into an extremely unfavorable anemia. This indicated that homeostatic maintenance in erythropoiesis would be impossible more below a quarter of normal renal tissue. These findings disclosed that reduction in functional renal tissue quantity would sensitively influence homeostatic maintenance of red blood cell production through the decrease in EPO production, even if it does not affect renal function concerned with urine production.

Anemia↗
PubMed1992

Endocrine cells and prognosis in patients with colorectal carcinoma.

Using chromogranin (CG) immunohistochemical staining, the prognostic significance of endocrine differentiation was investigated in 212 patients with primary colorectal adenocarcinoma (including 6 patients with mucosal carcinoma). CG-immunoreactive cells were found to be an integral component of the tumor in 67 of 206 patients (32.5%, excluding mucosal carcinoma). The intracellular localization of CG in the CG-immunoreactive cells in cancer tissue was completely different from that in the normal endocrine cells of the large bowel. In addition, morphologic changes such as nuclear hyperchromasia and pleomorphism also indicated that the CG-immunoreactive cells in the cancer tissue were malignant. The tumors were divided into three groups based on the frequency of CG-immunoreactive cells: Group I (n = 139), negative; Group II (n = 38), less than 1 positive cell/mm2; and Group III (n = 29), more than 1 positive cell/mm2. No correlation was observed between CG-immunoreactivity (CG-IR) and tumor location, grade, depth of invasion, or stage, regardless of lymph node involvement. However, patients with numerous endocrine tumor cells (Group III) had a significantly worse prognosis compared with patients without endocrine cells (Group I) (multivariate Cox's model, P less than 0.01). Similar findings were observed in patients with node-negative tumor (multivariate Cox's model, P less than 0.05). These results indicated that the neuroendocrine differentiation is an independent prognostic factor and that CG-immunohistochemistry is useful for detecting a subgroup with a worse prognosis among patients with colorectal cancer.

Biomarkers, Tumor↗
PubMed1992

Evaluation of plasma erythropoietin levels in normal adult dogs by in vivo bioassay using concentrated plasma.

Measurement of plasma erythropoietin level in normal dogs by in vivo bioassay has been considered to be impossible so far. In the present study, we successfully determined it by using concentrated plasma 60 times which allowed the lower limit to 2.7 mU/ml. This normal plasma erythropoietin level was the first to be determined as an in vivo bioactivity and was 9.14 +/- 7.81 mU/ml in 75 normal adult dogs. This value was sufficiently reliable in terms of accuracy of determination and considered to be meaningful as the low level in vivo bioactivity that hasn't been known to date. Furthermore, erythropoietin levels in normal plasma were within a certain lower range and showed neither difference in plasma erythropoietin level between males and females or among breeds nor correlation between erythropoietin and hemoglobin level.

Animals↗
PubMed1990

[Effects of the synthetic proteinase inhibitor, FOY, on hypercoagulability after surgery for esophageal carcinoma].

Hypercoagulability develops after surgery for esophageal carcinoma, and it related closely to postoperative complications. This study evaluated the effects of the synthetic proteinase inhibitor, Cabexate Mesilate (FOY), on this hypercoagulability. The subjects used were 25 patients with a mean age of 63 who had undergone surgery for esophageal carcinoma. Of these, eight patients (test group) received FOY (2,000 mg/day) for three to 23 days after surgery, but 17 (control group) did not. In the test group, FOY controlled aggregation and release of the platelets and minimized their exhaustion. FOY almost completely checked the abnormal increase in thrombin activity which might trigger the hypercoagulability. Also, FOY suppressed the fibrinolytic activity slightly. These results indicate that FOY is effective in controlling hypercoagulability after surgery for esophageal carcinoma and in suppressing activity of the proteinases that cause both blood coagulation and fibrinolysis.

Adult↗
PubMed1989

[Immunohistochemical and clinicopathological studies of chromogranin immunoreactive cells in large bowel carcinoma].

We examined the clinicopathological relevance of chromogranin immunoreactive cells in a well documented series of 212 large bowel cancer patients. Chromogranin immunoreactive cells were detected in 33.5% of the carcinomas, occurring either as rare cases (19.3%) or as diffuse cases (14.2%). The tumors with chromogranin immunoreactivity were associated with a more aggressive clinical course than tumors without immunoreactivity (Generalized-Wilcoxon; p less than 0.08). Moreover, the survival of patients with diffusely immunoreactive tumors was significantly shorter than that of patients without such cells (Generalized-Wilcoxon; p less than 0.009). Therefore, the study of chromogranin immunoreactivity in large bowel carcinomas may enable the identification of a subpopulation of colorectal carcinomas associated with a relatively poor prognosis.

Aged↗