Search PubMed⌕ Search

Biomedical subjects

K Ochi

Publications and source records attributed to K Ochi.

At least 181 records · Page 10Linked to original sources
PubMed1984

IgM-producing gastric plasmacytoma.

A case of gastric plasmacytoma is reported in an 81-year-old woman. Immunofluorescent and immunoelectrophoretic studies showed that the tumor cells produced IgM-lambda molecules, whereas no monoclonal immunoglobulin could be detected both in the serum and in the urine. Of more than 60 reported cases of gastric plasmacytoma, only a few reports referred to the production of monoclonal immunoglobulin by the tumor cells. This case is the first one of IgM-producing gastric plasmacytoma. Moreover, the produced IgM was found to be 7S-IgM. It is extremely rare that 7S-IgM alone is detected in the absence of 19S-IgM.

Aged↗
PubMed1984

Sequential changes in nuclear DNA content by chemotherapy observed in experimental canine gastric cancer.

It is known that the nuclear DNA contents correlate with the grade of malignancy. In this study, nuclear DNA contents of biopsy specimens taken from N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG)-induced canine gastric cancer were measured by Feulgen-DNA-cytofluorometry. The DNA content and histological findings were sequentially observed after weekly administration of 7-N-(p-hydroxyphenyl)-mitomycin C (0.8 mg/kg), a kind of mitomycin C derivative. The appearance rate of cells over 4C decreased remarkably from 18.8% to 9.86% on average (p less than 0.02) and the maximum value of distribution also went down from 9.18C to 7.33C (p less than 0.01) at the early stage of administration of the oncostatic agent when no histological change was yet observable. It might be expected that this procedure will enable the future evaluation of oncostatic effects at the cellular level more objectively.

Adenocarcinoma↗
PubMed1984

Reconstruction of a large lateral abdominal wall defect with an ilio-lumbar bi-pedicled flap.

An ilio-lumbar bi-pedicled flap was used for the reconstruction of a large lateral abdominal wall defect with a fascia lata graft to provide the musculo-fascial layer. This flap is simple and safe because it includes both the superficial circumflex iliac vessels and the perforating cutaneous branches of the lumbar vessels. We regard it as the method of choice in the repair of major defects of the lateral abdominal wall.

Abdominal Muscles↗
PubMed1984

Paradoxical tubular obstruction after release of ureteral obstruction in rat kidney.

The healing process of hydronephrosis was studied using rat kidney. Following release of 2 weeks' unilateral hydronephrosis, renal papilla and cortex were examined by scanning electron microscopy. Shortly after the release of obstruction, massive loss of brush border and ballooning of epithelial cells were noted in proximal tubules. Distal tubules and collecting tubules also showed severe ballooning of epithelial cells. Actually most of them were completely or nearly obliterated in spite of the release of ureteral obstruction. Two weeks later, on the other hand, the many tubular components became patent with normal epithelial lining. Some of them, however, deteriorated further in spite of the release of obstruction. Thus there was a marked tubular heterogenicity in recovery. The sudden decrease of the pelvic pressure and chronic ischemic state during ureteral obstruction may cause the tubular changes which were observed in this study.

Animals↗
PubMed1984

Initiation of antibiotic production by the stringent response of Bacillus subtilis Marburg.

Bacillus subtilis Marburg was found to produce an appreciable amount of an antibiotic in a synthetic medium. Antibiotic activity was produced in parallel with cell growth, and production stopped at the end of exponential growth. When the synthetic medium was supplemented with a small amount of Casamino acids, however, antibiotic was made only at the end of growth and in lesser amounts. The ability of cells to produce the antibiotic increased when stringent (rel+ = wild-type) cells underwent a partial stringent response. These conditions also initiated extensive sporulation. An isogenic relaxed (rel) strain produced little antibiotic activity, which decreased under partial amino acid deprivation. In rel+ cells, the addition of a low concentration of chloramphenicol, which reduces ppGpp synthesis, also reduced antibiotic synthesis in both normal and amino acid-starved bacteria, without appreciably affecting their growth rate. Guanosine starvation of a gua mutant initiated sporulation, but decreased antibiotic production. The results show that the stringent response initiates both sporulation (differentiation) and antibiotic production (secondary metabolism), but by different mechanisms. It appears that sporulation results from a decrease of GTP, whereas antibiotic synthesis results from a different effect of the stringent response.

Amino Acids↗
PubMed1984

Restoration of aerial mycelium and antibiotic production in a Streptomyces griseoflavus arginine auxotroph.

An arginine auxotrophic mutant was obtained from Streptomyces griseoflavus (bicozamycin-producing strain). The mutant grew on synthetic agar supplemented with either arginine, ornithine, citrulline or argininosuccinate, but produced massive aerial mycelium and bicozamycin only with citrulline. In liquid culture, citrulline also completely restored the ability of the mutant to produce bicozamycin. Culture with arginine or ornithine markedly changed intracellular pools of these ornithine-cycle amino acids, but did not affect the other amino acid pools. The ability to produce antibiotic (but not that to form aerial mycelium) was partially restored by certain mutations to ethionine resistance (Eth-1 and Eth-2). These mutations caused decreased or increased S-adenosylmethionine synthetase activity, but both resulted in a 4.5-8-fold increase in the intracellular S-adenosylmethionine pool. Exogenous addition of S-adenosylmethionine (0.5-3 mM) also partially restored the antibiotic-producing ability of the arginine auxotroph. No difference in the S-adenosylmethionine pool was observed in organisms grown with arginine and citrulline. It was suggested that citrulline and S-adenosylmethionine are somehow involved in the initiation of differentiation and secondary metabolism of S. griseoflavus.

Amino Acids↗
PubMed1984

Arsenazo III signals following action potential as influenced by nitrate in Xenopus skeletal muscle.

Arsenazo III was injected into a Xenopus skeletal muscle fiber to measure the changes in myoplasmic free Ca2+ concentration following an action potential. The arsenazo III signal started to rise after a latent period of 2.4 msec, attained its peak at another 5.0 msec and then decayed exponentially with a half time of 15.6 msec, at 22-24 degrees C. Nitrate ions prolonged the falling phase with a slight increase in the peak amplitude. It is suggested that nitrate produces continuous Ca release as well as augmentation of the initial burst of Ca release in highly stretched muscle fibers.

Action Potentials↗
PubMed1984

Effects of twitch potentiators and repetitive stimulation on arsenazo III Ca-transients in Xenopus skeletal muscle fibers.

Ca indicator dye arsenazo III (AZ III) was injected into Xenopus skeletal muscle fibers. AZ III Ca-transients (AZ III signals) responding to the electrical stimulation of the fibers were measured by a pair of photomultipliers at 651-721 nm. In the standard Ringer solution at 22-23 degrees C, the latency of the AZ III signal (T1), the time from the onset of signal to the peak (T2), and the half decay time (T3) were 1.5, 3.9, and 16.6 msec, respectively. The falling phase of the signal was fitted to the exponential curve. The effects of repetitive stimulation with frequency of 10, 20, and 30/sec were investigated. The AZ III signal at 30/sec showed obvious summation. Prolongation of the falling phase with an increase in stimulating pulses or in stimulus frequency was always observed. In the solution which contained twitch potentiators such as NO3-, Zn2+, and caffeine, the peak of the AZ III signal showed a 10-50% increase and T1, T2, and T3 were increased by 20-100%. The falling phase of the AZ III signal was convex on the logarithmic scale in NO3 or Zn solution, and fitted to the exponential curve in caffeine solution. The factors which determined the falling phase are discussed.

Animals↗
PubMed1984

[Reoperation of recurrent gastric cancer--a comparative study of a resected and nonresected group].

A retrospective study was made on 51 patients with recurrent gastric cancer following partial or subtotal gastrectomies during the past 17 years. Thirteen patients (25.5%) underwent resection of recurrent lesions, of which 12 were total resection of gastric remnant with combined removal of the distal pancreas, spleen, transverse colon and/or a part of the liver. The operative mortality rate was only 7.6%, and the one-year survival rate was 41.7%. There is a necessity for aggressive surgery in cases proved histologically to be stage I or II after the initial operation. The surgical procedure is not effective for stage III and IV patients, except for cases of local recurrence.

Adult↗
PubMed1983

Arachidonate 5-lipoxygenase of guinea pig peritoneal polymorphonuclear leukocytes. Activation by adenosine 5'-triphosphate.

Arachidonate 5-lipoxygenase was isolated from guinea pig peritoneal polymorphonuclear leukocytes, and partially purified from a high speed supernatant of a homogenate. 5-Hydroperoxy-6,8,11,14-eicosatetraenoic acid was a predominant reaction product. The enzyme reaction required specifically calcium ion (20 microM for half-maximal activity), and other divalent cations such as magnesium and cobalt were ineffective. The calcium-dependent 5-lipoxygenase reaction was stimulated by several nucleotides, most prominently by ATP in the order of 1 mM. 5,8,11,14,17-Eicosapentaenoic acid as substrate was as active as arachidonic acid, and was oxygenated at the C-5 position.

Adenosine Triphosphate↗
PubMed1983

The fine structure of pancreatic stones as shown by scanning electron microscopy and X-ray probe microanalyser.

To delineate the process of pancreatic stone formation, stones from four patients were studied with a scanning electron microscope and X-ray probe microanalyser. The stones consisted of a central core and surrounding shell. Two kinds of stones were demonstrated: one had a core composed of a calcium-rich amorphous substance and interlacing fibrils; the other had a core consisting of multiple cavities with smooth walls composed of a calcium-deficient amorphous substance. The shells showed a common structure: zones of layers or bands of a calcium-rich amorphous substance, network fibrils filled with a calcium-rich amorphous substance, and laminated parallelogrammic or polygonal plates of calcite parallel to the surface in one layer and oblique or perpendicular in the next layer. Calcium was in the crypto-crystalline state as well as crystalline state of calcite. Crystalline calcite showed spiral and epitaxial growth along with findings of dissolution, resembling cholesterol crystals of gall stones. Pancreatic stones are probably formed through central core formation and layered growth of a shell. Comparison of stones and protein plugs suggests that protein plugs can grow to stones with calcite deposition accompanied by precipitation of network fibrils and an amorphous substance.

Bacteria↗
PubMed1983

Purification and properties of bovine liver gamma-glutamyltransferase.

gamma-Glutamyltransferase [EC 2.3.2.2] (gamma-GTP) was purified to a homogeneous state from bovine liver. It had an apparent molecular weight of about 110,000, as judged by polyacrylamide gel electrophoresis, and consisted of two non-identical glycopeptides with molecular weights of 68,000 and 27,000. The amino acid composition of the bovine liver enzyme was similar to those of other gamma-GTPs. The enzyme contained large amounts of neutral sugars, amino sugars and sialic acid, although the sialic acid content varied in different preparations. The Michaelis constant of the enzyme was estimated to be 0.8 mM for gamma-L-glutamyl-p-nitroanilide in the presence of glycylglycine and 1.25 mM in the absence of glycylglycine. Glutathione competitively inhibited the release of p-nitroaniline from gamma-L-glutamyl-p-nitroanilide with a Ki value of 0.3 mM. The specific activities of the enzyme for gamma-L-glutamyl-p-nitroanilide in the presence of glycylglycine (pH 8.6) and for glutathione, a natural substrate (pH 7.4), were comparable to those reported for gamma-GTPs from other mammalian sources. The bovine liver enzyme showed the same gamma-glutamyl group acceptor specificity as other gamma-GTPs from normal mammalian tissues. The phosphate-independent glutaminase activity of the enzyme was much lower than that of the rat kidney enzyme both in the presence and absence of maleate.

Amino Acids↗