Biomedical subjects

K Ogawa

Publications and source records attributed to K Ogawa.

At least 19 recordsLinked to original sources

PubMed1992

[Hormone therapy using tamoxifen in unresectable carcinoma of the pancreas--preliminary study].

In 1981 Greenway and co-authors reported the existence of estrogen receptor in tumor tissue of the pancreas. We have tried hormone therapy using tamoxifen in 4 of 11 patients with unresectable carcinoma of the pancreas in whom expandable metallic stents were inserted for the palliation of obstructive jaundice. The mean survival period in these 4 patients was 235 days, and 2 of them had a remarkably long survival of 321 and 463 days respectively. On the other hand, the mean survival was 128 days in 7 control patients. We therefore evaluated this new therapy with tamoxifen as effective in patients with unresectable carcinoma of the pancreas.

Estrogens↗

PubMed1992

Molecular and crystal structure of konjac glucomannan in the mannan II polymorphic form.

A probable crystal structure of konjac glucomannan (mannose:glucose ratio = 1.6) is proposed based on X-ray data and constrained linked-atom least-squares model refinement. The structure crystallizes in the mannan II polymorphic form, in an orthorhombic unit-cell with a = 9.01 A, b = 16.73 A, c (fiber axis) = 10.40 A, and a probable space group I222. The backbone conformation of the chain is a two-fold helix stabilized by intramolecular O-3-O-5' hydrogen bonds, with the O-6 rotational position gt. The unit cell contains four chains with antiparallel packing polarity and eight water molecules which reside in crystallographic positions. Intermolecular hydrogen bonds occur exclusively between chains and water molecules, establishing a three-dimensional hydrogen-bond network in the crystal structure. The glucose residues replace mannoses in the structure in isomorphous fashion, although some disorder appears possible. A structure having alternating gg-gt O-6 rotational positions and conforming to space group P222 appears to describe the disorder regions of the crystal. The reliability of the structure analysis is indicated by the X-ray residuals R = 0.276 and R" = 0.223.

Carbohydrate Conformation↗

PubMed1992

Molecular and crystal structure of the regenerated form of (1----3)-alpha-D-mannan.

The crystal structure of the hydrated form of (1----3)-alpha-D-mannan, obtained by solid-state deacetylation of the partially O-acetylated mannan, was analyzed by combined X-ray diffraction and stereochemical-model refinement techniques. The structure crystallizes in a four-chain, monoclinic unit cell with parameters a = 11.33 A, b = 18.36 A, c (fiber repeat) = 8.25 A, and gamma = 101.75 degrees, and the most probable space group is P2(1). In the most probable structure the chain-backbone conformation is a two-fold helix, but with all four O-6 rotational positions nonequivalent. The chains pack with antiparallel polarity and are connected by pairs of intermolecular hydrogen bonds that form an infinite, zig-zag sheet. There are 16 water molecules in the unit cell, generally embedded between the sheets in crystallographic positions, providing additional hydrogen bonding and establishing a three-dimensional hydrogen-bond network in the crystal structure. The reliability of the structure analysis is indicated by the X-ray residual R" = 0.281, based on 98 hkl reflection intensities.

Acetylation↗

PubMed1992

[Percutaneous transluminal angioplasty for stenotic dialysis arterio-venous fistulas].

From December 1982 to January 1991, we performed fistulography on 40 patients who complained functional failure of arterio-venous dialysis fistula. And percutaneous transluminal angioplasty (PTA) was attempted on 15 patients (19 times) who revealed marked fistula stenosis. Initial successful rate was 78.9% and patency rate was 56.2% in the first 6 months. (75% in the first 6 months when angioplasty was initially successful). We describe the method of fistulography and PTA for stenotic dialysis fistulas, and evaluate the usefulness of PTA. And also we introduce our attempts for improving the initial successful rate and patency rate. In conclusion, when dialysis arterio-venous fistula is stenotic but not occlusive, PTA should be considered first before surgical treatment is done.

Adult↗

PubMed1992

Synthesis and inotropic activity of pyrazolo[4,3-c]pyridine-4-ones and related compounds.

Two series of 3,6-dimethyl-1-phenyl-1H-pyrazolo[4,3-c] pyridine-4-ones (5-9) and 3,6-dimethyl-1-phenyl-1H-pyrazolo[4,3-c] pyridine-4-thiones (11-13) were prepared from dehydroacetic acid as starting material and evaluated for positive inotropic activity in vitro. Moreover, the activity of the synthesized compounds was compared with that of mirlinone as a reference. Among these compounds, the positive inotropic activity of 8a, 11a, and 12 were approximately 1.24, 1.77, and 1.11 times more potent, respectively, than that of mirlinone.

Animals↗

PubMed1992

Lack of effects of post-initiation cholesterol on 3,2'-dimethyl-4-aminobiphenyl-induced prostate carcinogenesis.

The effects of cholesterol on 3,2'-dimethyl-4-aminobiphenyl (DMAB)-induced rat prostate carcinogenesis were investigated in male F344 rats. Animals were given 10 subcutaneous (s.c.) injections of 50 mg/kg body weight of DMAB at 2-week intervals, each time 2 days after transfer from 1 week on 0.75 ppm of an ethinyl estradiol (EE)-supplemented diet to a basal diet. From week 20, the animals received treatment with cholesterol (2 or 1%, in the diet), saponin (1 or 0.2 mg/rat/week, s.c.), or clofibrate (0.3%, in the diet) for 40 weeks. Although serum cholesterol levels were significantly increased by administration of cholesterol itself, and were decreased by clofibrate, the incidences of atypical hyperplasias and carcinomas of the ventral prostate were very similar with all treatments. Thus, under the present conditions, high or low cholesteremia did not affect rat prostate lesion development.

Aminobiphenyl Compounds↗

PubMed1992

Transcatheter hepatic arterial chemoembolization using epirubicin-lipiodol: experimental and pharmacological evaluation.

The experimental and pharmacological characteristics of various formulations of an anticancer agent (epirubicin, EPI) and lipiodol were evaluated in vitro and in vivo. Three forms of EPI-lipiodol, i.e., an oil-in-water type of emulsion (O/W type), a water-in-oil type of emulsion (W/O type), and a suspension (S type), were prepared and investigated for their stability. An O/W-type emulsion using a stock solution of Iopamidol as the solvent for EPI was the most stable form in the stationary state in vitro. In 16 patients with malignant liver tumors (14 hepatocellular carcinomas and 2 liver metastases), the three forms of EPI-lipiodol were injected into the proper hepatic artery. The plasma EPI level was monitored periodically and analyzed pharmacokinetically. No significant difference in the pharmacokinetics of EPI was detected among the O/W, W/O, and S types.

Aged↗

PubMed1992

Postnatal changes in fatty acids composition of brown adipose tissue.

It has been demonstrated that thermogenic activity of brown adipose tissue (BAT) is higher during the early postnatal period, decreasing towards a low adult level. The present study examined postnatal changes in the lipid composition of BAT. BAT from pre-weaning rats at 4 and 14 days old showed the following differences in lipid composition compared to that from adults of 12 weeks old. (i) Relative weight of interscapular BAT to body weight was markedly greater. (ii) BAT-triglyceride (TG) level was lower, while BAT-phospholipid (PL)level was higher. (iii) In TG fatty acids (FA) polyunsaturated fatty acids (PU; mol%), arachidonate index (AI), unsaturation index (UI) and PU/saturated FA (SA) were higher; rare FA such as eicosadienoate, bishomo-gamma-linolenic acid and lignoceric acid in mol % were also higher. (iv) In PL-FA monounsaturated FA (MU) in mol % was lower; PU mol %, AI and UI were higher. These features in BAT of pre-weaning rats resembled those in the cold-acclimated adults, suggesting a close relationship of the PL-FA profile to high activity of BAT.

Adipose Tissue, Brown↗

PubMed1992

Effects of running training on in vitro brown adipose tissue thermogenesis in rats.

Brown adipose tissue (BAT) is a major site of nonshivering thermogenesis (NST) during cold acclimation for most mammals. Repetitive nonthermal stress such as immobilization has been shown to enhance the capacity of NST as cold acclimation. In the present study, the effects of running training, another type of nonthermal stress, were investigated on in vitro thermogenesis and the cellularity of interscapular BAT in rats. The rats were subjected to treadmill running for 30 min daily at 30m/min under 8 degrees inclination for 4-5 weeks. In vitro thermogenesis was then measured in minced tissue blocks incubated in a Krebs-Ringer phosphate buffer containing glucose and albumin at 37 degrees C, using a Clark type oxygen electrode. The trained rats showed less body weight gain during the experiment. The weights of BAT and epididymal white adipose tissue were smaller in the trained rats. Noradrenaline- and glucagon-stimulated oxygen consumption were also significantly smaller in the trained rats. The tissue DNA level was greater in the trained rats, but the DNA content per tissue pad did not significantly differ. The results indicate that running training reduces BAT thermogenesis, possibly as an adaptation to conserve energy substrates for physical work.

Adipose Tissue, Brown↗

PubMed1992

Complete disappearance of metastatic abdominal tumors from gastric cancer after treatment with irsogladine maleate.

A 60-year-old woman with gastric cancer had undergone partial gastrectomy in September 1989. Pathological examination revealed a poorly differentiated adenocarcinoma of pT3pN3pM0 (not resected for cure), stage IV. Postoperative adjuvant therapy comprised 1-(tetrahydro-2-furanyl)-5-fluorouracil plus uracil and OK-432. On 11 August 1990, two forefinger-tip-sized tumors were palpated beneath the operation scar. They increase in size, the superior tumor reaching 4x3 cm, the inferior tumor 5x3 cm on 5 September. Then, on 17 September, the inferior tumor was resected but the superior tumor remained; the histological type was poorly differentiated adenocarcinoma. After the operation, from 20 September, she was given 4 mg irsogladine maleate orally every day. On 8 October, there was no increase in the size of the superior tumor. By 29 October, the superior tumor had disappeared and no further tumor appeared thereafter; the patient showed no sign of relapse.

Abdominal Neoplasms↗

PubMed1992

Effects of postnatal ganglioside administration and hypoxia-exposure on the dopamine release from striatal slices, the behaviour and the ganglioside pattern of 2-3 months old rats.

Neonatal rats were injected with a mixture of bovine brain gangliosides (30 mg/kg body weight, s.c.) immediately before the exposure to hypoxia (pO2 = 10 kPa, 10 hrs daily) from the 2nd to the 11th day of life. At the age of 2-3 months the potential protective or restitutive effect of gangliosides on the radiolabelled dopamine release from striatal slices and on the conditioned avoidance learning was studied. No change in the content and the pattern of gangliosides of the rat striata was found after exposure to hypoxia and ganglioside administration, respectively. Both hypoxia exposure and ganglioside treatment of controls increased the dopamine release whereas hypoxic animals treated with gangliosides showed a diminished release. Hypoxia-induced impaired conditioned avoidance learning was improved by ganglioside treatment. The changed release of dopamine and the altered behavioural performance after ganglioside treatment alone indicate the necessity of a very cautious application of gangliosides to the developing brain.

Aging↗

PubMed1992

Histological pancreatitis in end-stage renal disease.

To clarify a possible cause of hyperamylasemia in end-stage renal disease (ESRD), histological studies were performed on the pancreatic glands of twenty-seven autopsied patients with ESRD who had received long-term hemodialysis. The findings were compared with those in a similar number of age-matched control subjects. Histological evidence of pancreatitis was found in 51.9% of the ESRD patients as compared with 14.8% in the controls (p < 0.005). The pancreatitis was chronic in nature in 85.7% of the ESRD patients showing changes of pancreatitis. Secretin administration to an additional group of twelve patients with ESRD induced an elevation in the activities of both total and P-type serum amylase in only one patient. These findings suggest that although histological pancreatic alterations are common in patients with ESRD, they are probably not responsible for the P-type hyperamylasemia frequently found in such patients.

Adult↗

PubMed1992

SPECT demonstration of splenosis.

Splenosis is defined as the heterotopic autotransplantation of splenic tissue. The main cause of splenosis is splenic rupture following abdominal trauma, in which fragments of splenic tissue are seeded throughout the peritoneal cavity. Demonstration of splenosis by scintigraphy or CT imaging has been reported, but there is no previous report of simultaneous demonstration by SPECT and CT imaging. Autotransplantation of splenic tissue in the abdominal cavity forms a solid tumor-like image on CT and is difficult to differentiate from other abdominal masses. In such cases, SPECT demonstration of splenosis is very important for identification of its exact site. A case report of splenosis is presented, in which simultaneous demonstration by SPECT and CT was performed. This was confirmed at laparotomy for gastrectomy.

Abdominal Neoplasms↗

PubMed1992

Enzymatic synthesis of p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside as a substrate for human alpha-amylases.

Enzymatic modification at the nonreducing end D-glucosyl residue of p-nitrophenyl alpha-maltopentaoside was developed by using the transglycosylation of beta-D-galactosidase from Bacillus circulans. The enzyme regioselectively synthesized p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside (a yield of 12.0% based on the amount of p-nitrophenyl alpha-maltopentaoside added) on a preparative scale from lactose as a donor and p-nitrophenyl alpha-maltopentaoside as an acceptor. It revealed that the nonreducing end galactosyl group of p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside did not prohibit the action of human salivary and pancreatic alpha-amylases. This derivative was shown to be very suitable as a novel substrate for analytical use of human alpha-amylase assay in serum through a conjugated reaction involving glucoamylase and alpha-D-glucosidase.

Amylases↗

PubMed1992

Oleanane glycosides from Glycyrrhiza yunnanensis roots.

From the roots of Glycyrrhiza yunnanensis, collected in Yunnan, China, six new oleanane-type triterpene glycosides named yunganosides A1, B1, C1, D1, E2 and F2 were isolated together with hypaphorine. The structures of these glycosides were established by spectroscopic and chemical means.

Carbohydrate Sequence↗

PubMed1992

Histological detection of c-myb and c-myc proto-oncogene expression in infiltrating cells in cutaneous lupus erythematosus-like lesions of MRL/l mice by in situ hybridization.

A relationship between lymphocytic activation and the overexpression of proto-oncogenes such as c-myb or c-myc has been demonstrated in human autoimmune disease. In autoimmune-prone MRL/l mice, which spontaneously develop lupus erythematosus (LE)-like lesions on the back, increased expression of myb RNA has been found in the lymphoid organs. We detected the overexpression of c-myb and c-myc proto-oncogenes in infiltrating cells in the cutaneous lesions of MRL/l mice by using in situ hybridization. No specific hybridization signals of either of the probes used were seen in the nonlesional skin of MRL/l mice or in the apparently normal skin of aged MRL/n and young MRL/l mice. These results suggest that the increased expression of myb and myc proto-oncogenes in the cutaneous LE-like lesions of MRL/l mice is related to a state of activation in the infiltrating cells and is involved in the development of these lesions.

Animals↗

PubMed1992

Uracil-induced urolithiasis in the urinary bladder of rats is irritation-dependent.

The correlation between urolithiasis due to uracil administration and epithelial proliferation in the urinary bladder was investigated in male F344 rats. Animals, 6 weeks old at the start, which ingested 3% uracil alone in the diet for 4 weeks developed urolithiasis and papillomatosis of the urinary bladder, whereas addition of NaCl, particularly at high concentration (10%), to the 3% uracil in the diet blocked production of both. In contrast, NaHCO3 was without influence on either calculi or proliferative changes. These results indicate that uracil-induced epithelial proliferation is due to direct mechanical irritation by calculi, and not to any chemical stimulus presented by uracil itself.

Animals↗

PubMed1992

Light and electron microscopic study of vestibular sensory epithelia in 17 cases with acoustic neurinoma.

Vestibular sensory epithelia were studied histologically and ultrastructurally in 17 cases with acoustic neurinoma (AN). The superior vestibular nerve (SVN) near the fundus was also histologically studied in 5 of these 17 cases. Histologically, severe fibrotic change of the vestibular sensory epithelia was found in 1 case, and severe fibrotic change of the SVN was also found in this case. Intra-epithelial cysts were found at the edge of the utricular sensory epithelia in 2 cases. The cysts consisted of the transitional epithelium and were filled with the darkly stained substances. Ultrastructurally, abnormal accumulation of darkly stained masses within the nerve ending and abnormal accumulation of the fibrillar material below the normal basal lamina were frequently observed. These morphological changes described above were regarded as the pathological changes due to AN. In addition, the relationship among the histologic changes, ultrastructural changes and clinical data were fully investigated, and some histologic and ultrastructural changes were regarded as artifacts or age-related changes.

Adult↗