Search PubMed⌕ Search

Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 307 records · Page 17Linked to original sources
PubMed1992

Human myeloma cell line (KHM-4) established from a patient with multiple myeloma associated with hyperammonemia.

A cell line of plasma cells with high ammonia (NH3) production (KHM-4) was established from a patient with multiple myeloma complicated by hyperammonemia and abnormal serum concentrations of amino acids. Surface marker studies of KHM-4 cells showed that the cells were positive for cytoplasmic immunoglobulins (IgA kappa), HLA-DR, and T 10. Secretion of ammonia by the KHM-4 cells was detected by the addition of L-glutamine and L-arginine into the culture medium of amino acid-free RPMI 1640. In the presence of L-glutamine, KHM-4 cells secreted a greater amount of ammonia than the T cell line, CEM. However, production of ammonia by L-arginine was not observed in other cell lines. These observations provide evidence for the existence of a peculiar amino acid metabolism in the myeloma cells causing hyperammonemia and serum amino acid disturbance.

Ammonia↗
PubMed1992

[Effect of hypotensive anesthesia on tissue oxygen tension of the heart, kidney and liver].

The effects of hypotensive anesthesia by prostaglandin E1 (PGE1: 8 dogs) or trimetaphan (TMP: 8 dogs) on tissue oxygenation were studied in 16 mongrel dogs anesthetized with pentobarbital. Mean blood pressure (MBP), heart rate (HR), cardiac output (CO), blood gases (BG), the blood flow and tissue oxygen tension of the heart, the kidney and the liver were measured. The blood flow and oxygen tension were measured by electromagnetic flowmeters and by polarographic oxygen electrodes respectively. PGE1 or TMP was injected intravenously to decrease MBP by 30%. MBP, CO, HR and BG of PGE1 were not significantly different with those of TMP. Coronary blood flow decreased for 12% with PGE1 and for 33% with TMP. Though blood flows of the renal and the hepatic arteries were well maintained with PGE1, they decreased for 36% and 34% respectively with TMP. Oxygen tensions of the myocardium (both outer and inner layers) and the liver were well maintained with PGE1. But with TMP, oxygen tension decreased for 23% in outer layer, for 16% in inner layer and for 31% in the liver. Oxygen tension of the kidney remained unchanged with PGE1 and TMP. The results suggest that PGE1 is more useful for the maintenance of the tissue oxygenation than TMP during hypotensive anesthesia.

Anesthesia↗
PubMed1992

Tuberculous peritonitis with extraordinarily high serum CA125.

A 74-year-old woman who was admitted for the evaluation of ascites showed a marked elevation of serum CA125 level. Laparoscopy revealed the presence of numerous white modules (approximately 5 mm diameter) on the peritoneum suggestive of tuberculomas. A biopsy specimen showed epithelioid cells and Langhans-type giant cells. Following the administration of diuretics, the level of serum CA125 decreased concomitantly with the decrease in the volume of peritoneal fluid. The level of CA125 decreased further with the administration of antituberculosis agents. Clinical specimens were negative for mycobacteria. We conclude that the elevated serum level of CA125 was due to peritoneal tuberculosis and consequent ascites. Thus, tuberculous peritonitis should be considered in the presence of an unexplained, abnormally elevated serum level of CA125.

Aged↗
PubMed1992

[Effect of carbon dioxide (hypocapnia and hypercapnia) on regional myocardial tissue oxygen tension in dogs with coronary stenosis].

Carbon dioxide (CO2) has been well documented to act as a potent vasodilator of coronary vessels under normal conditions. But there is little data available on the effect of CO2 on the collateral perfusion of patients with coronary insufficiency. We studied the effects of CO2 on the myocardial tissue PO2 in anesthetized dogs with critical coronary stenosis. Twelve mongrel dogs were anesthetized with pentobarbital and ventilated with 100% O2 to maintain normocapnia. Electromagnetic blood flow (BF) probe was applied on the left anterior descending artery (LAD). Regional myocardial PO2 was measured at two different sites using two pairs of monopolar polarographic needle electrodes; one inserted in the epicardial (EPI) layer, and the other in the endocardial (ENDO) layer. These were placed in the regions supplied by LAD and circumflex. Following the baseline recording, critical stenosis of LAD was produced by adjusting a copper-wire clamp occluder until LADBF was reduced by 50%. After a stable normocapnic ventilation, hypocapnia was produced by hyperventilation. To induce hypercapnia, exogenous CO2 was added to the inspired gas stepwise until end-tidal CO2 fraction reached 10%. Hypocapnia resulted in a significant reduction in myocardial PO2 in both EPI and ENDO non-stenotic areas, while hypercapnia increased these PO2 values dose-dependently. After coronary stenosis, hypocapnia resulted in a small but significant reduction of PO2 in endocardial ischemic area. Hypercapnia did not induce any sign of reduced regional myocardial PO2 or evidence of regional or intramural "steal" phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Rehabilitation in rheumatoid arthritis].

In the patient with rheumatoid arthritis, muscle weakness and joint contracture and deformity develop, despite the most carefully directed programs of medical care. At the acute phase of this disease, the immobilization or stabilization of arthritic joints is effective for the improvement of inflammation without risk of contracture. At the chronic phase, the patients should be carefully instructed as to the importance of the joint mobility exercise and muscle strengthening exercise. Finally, we must consider that patients with rheumatoid arthritis suffer not only from painful joints but also from psychological and socio-economical damage.

Activities of Daily Living↗
PubMed1991

Detection of somatic DNA recombination in the transgenic mouse brain.

A DNA construct containing the bacterial beta-galactosidase gene (lacZ) was used to study somatic DNA recombination in the transgenic mouse brain. Recombination-positive areas of the adult brain were stained blue with X-gal, a substrate of beta-galactosidase. Blue-colored cells appeared soon after birth, and continued to emerge in postnatal tissue. Staining was prominent in sensory as opposed to motor regions of the brain, and was present in more than 70 discrete areas of the nervous system. The possibility of DNA rearrangement is discussed with respect to the development of the central nervous system.

Animals↗
PubMed1991

Identity of mucin's "118-kDa link protein" with fibronectin fragment.

Human and rat intestinal mucin was purified by equilibrium density gradient centrifugation and Sepharose 2B chromatography according to M. Mantle, D. Mantle, and A. Allen (1981, Biochem. J. 195, 277-285) and analyzed using mucin, DNA, and fibronectin-specific antibodies in dot-blot, ELISA, and Western blotting. The 118-kDa component of the mucins and the 118-kDa fragment of fibronectin from the same source displayed affinity for concanavalin A and immunoreacted with fibronectin antibodies. The amino acid and carbohydrate compositions of the 118-kDa peptide electroeluted by gel electrophoresis of mucin and fibronectin preparations were identical within each pair of glycopeptides and closely resembled the "link protein component" of human and rat intestinal mucin preparations of R. E. F. Fahim, R. D. Specian, G. G. Forstner, and J. F. Forstner (1987, Biochem. J. 243, 631-640) and M. Mantle and G. Stewart (1989, Biochem. J. 259, 631-640). We therefore conclude that the "link protein" claimed to be an integral part of mucus glycoproteins in actuality is the 118-kDa fragment of fibronectin.

Amino Acids↗
PubMed1991

Physical characteristics of Ti-6A1-4V implants fabricated by electrodischarge compaction.

Physical characteristics of a Ti-6A1-4V implant were evaluated following fabrication using a new electrodischarge compaction technique. Ti-6A1-4V atomized powders were loaded into Pyrex tubes (3.3 mm ID) and subjected to a high-voltage, high-current-density pulse in air for a period of less than 300 microseconds. Single pulses (1.0, 1.5, 2.0 and 2.5 KJ/grampowder) were applied from a capacitor bank (240, 480 or 720 microF) to produce solid core implants with porous surface layers. Implants were evaluated microscopically for core size, neck size, pore size, grain structure, and incorporated oxide film. Hardness was also evaluated. Implants were compared with Ti-6A1-4V commercial powders. Core size increased and pore size decreased with increases in energy and capacitance. The cores were composed of equiaxed grains which were free of oxide at the grain boundary. Porous layers, consisting of particles connected in three dimensions by necks, were free of oxide films at the connecting interfaces. Neck size increased with increases in input energy and capacitance. Hardness readings of the core, necks, and porous particles resulted in readings higher than or similar to control materials. Electrodischarge compaction did not alter the physical characteristics during compaction.

Alloys↗
PubMed1991

BHV-1 adsorption is mediated by the interaction of glycoprotein gIII with heparinlike moiety on the cell surface.

The gIII glycoprotein of bovid herpesvirus 1 (BHV-1) has been shown to mediate the adsorption of the virions to cells (K. Okazaki, E. Honda, T. Minetoma, and T. Kumagai, 1987, Arch. Virol. 97, 297-307). In this study, the cellular receptor for BHV-1 was investigated. Addition of heparin to the virus inoculum and treatment of the cells with heparinase prevented the virus from adsorbing to and infecting the cells. Of the major glycoproteins of BHV-1 only gIII was found to bind specifically to heparin. The binding of gIII was inhibited by a monoclonal antibody against antigenic site Ia, which interferes with the adsorption of the virus. These findings indicate that the virus adsorption to cells is mediated by interaction of the gIII antigenic site Ia with a heparinlike moiety on the cell surface, which serves as a receptor for BHV-1.

Adsorption↗
PubMed1991

The ste4+ gene, essential for sexual differentiation of Schizosaccharomyces pombe, encodes a protein with a leucine zipper motif.

Ste4- mutants of Schizosaccharomyces pombe are unable to undergo both mating and meiosis. We have cloned the ste4+ gene and its cDNA. The gene encodes a 264 amino acid protein with a typical leucine zipper motif homologous with the jun family. However, unlike the jun family, this protein does not have a typical basic region that precedes the leucine zipper. The transcription of this gene absolutely depends on the ste11+ gene and increases several fold upon nitrogen starvation, a general signal for sexual differentiation. Whereas ste4+ is essential for mating and meiosis, its overexpression inhibits these processes.

Amino Acid Sequence↗
PubMed1991

Palate morphology in children with cleft palate with palatalized articulation.

This study was designed to examine postoperatively morphological characteristics of the palate of children with cleft palate with palatalized articulation. Palate morphology was measured in children with good velopharyngeal closure function after surgery, who were classified in Hellman's Dental Age II A group with unilateral cleft lip and palate, and the groups of children with palatalized articulation (CP-P) and normal articulation (CP-N) were compared. The results showed that the group of children with palatalized articulation was characterized by small palatal volume. In particular, there was narrowing and shortening of the anterior palate, and the palate was shallow. It was surmised that morphology may be one cause of palatalized articulation. Accordingly, it is important that early tongue-clicking movements are encouraged in patients exhibiting narrow palate morphology.

Articulation Disorders↗
PubMed1991

Correlation between physiological and transforming activities of the c-mos proto-oncogene product and identification of an essential Mos domain for these activities.

Using Xenopus eggs and NIH3T3 cells as assay systems, we have compared the physiological (i.e., maturation-inducing and cleavage-arresting) and in vitro transforming activities of the c-mos genes from various species as well as their mutant genes. These analyses show that the three biological activities all depend upon the intrinsic protein kinase activity of Mos and correlate well with each other. Furthermore, our results demonstrate that a well conserved N-terminal 14-amino acid sequence of Mos, termed the Mos-box, is essential for all three activities. These results indicate that the in vitro transforming activity of Mos can be ascribed to the same kinase activity of Mos that exerts the physiological activities.

Amino Acid Sequence↗
PubMed1991

Alteration of physiological activity of activated macrophages through L-arginine metabolism.

Our aim in this study was to define the effect of L-arginine on macrophages (M phi) in relation to the decay of tumoricidal activity of activated M phi. We found that the activated M phi retained their cytotoxicity when cultured in L-arginine-deficient medium but not in conventional medium. Such a decline of tumoricidal activity was associated with increase of glucose consumption and concomitant lactate production, resulting in M phi death. Addition of glucose to the culture medium of activated M phi appeared to cause only a slight delay of the decrease of tumoricidal activity and M phi death. These events were also coincident with a decrease of electron transport activity in mitochondria. Cytological observation by electron microscopy clearly showed the structural alteration or destruction of mitochondria, which preceded the changes of other physiological and functional activities. These results demonstrate that the L-arginine-dependent cytolytic activity against tumor target cells also impairs M phi functions and ultimately induces M phi death, which is primarily mediated by the inhibition of mitochondrial activity.

Animals↗
PubMed1991

HMG1-related DNA-binding protein isolated with V-(D)-J recombination signal probes.

In order to isolate cDNA clones for DNA-binding components of the V-(D)-J recombinase, phage libraries from a pre-B-cell line were screened with a radiolabeled probe containing recombination signal sequences (RSS). Among prospective clones, cDNA T160 was analyzed further. It produced a protein of 80.6 kDa which bound to DNA containing RSS but not to DNA in which the RSS had been mutated. A search of a data base revealed that the T160 protein has significant sequence homology (56%) to the nonhistone chromosomal protein HMG1 within the C-terminal region of 80 amino acids. DNA-binding analysis with truncated proteins showed that the HMG homology region is responsible for DNA binding. Using restriction fragment length polymorphisms, the T160 gene was mapped at the proximal end of mouse chromosome 2. Evidence was obtained for genetic linkage between the T160 gene and the recombination activator genes RAG-1 and RAG-2.

Amino Acid Sequence↗
PubMed1991

Binding of a factor to an enhancer element responsible for the tissue-specific expression of the chicken alpha A-crystallin gene.

We have characterized a regulatory region of the chicken alpha A-crystallin gene using transfection assays, which revealed that a 84 base pair element (-162 to -79) in the 5' flanking sequence is necessary and sufficient for lens-specific expression. A multimer of this element functions as lens-specific enhancer and synergistically activates transcription from chicken alpha A-crystallin or beta-actin basal promoters fused to the CAT gene. In vivo competition experiments demonstrated that DNA sequences containing the 84 bp element reduced alpha A-crystallin-CAT fusion gene expression. A nuclear factor present exclusively in lens cells binds to the 84 bp element in the region between positions -165 and -140. Southwestern blot analysis showed that 61,000 Mr (61 x 10(3) Mr) lens nuclear protein exhibited DNA-binding activity specific to the 84 bp element. Our data suggested that the 61 x 10(3) Mr nuclear protein, and the 84 bp element that it interacts with, may be involved in regulating the alpha A-crystallin gene expression in vivo.

Animals↗