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Biomedical subjects

K Okazaki

Publications and source records attributed to K Okazaki.

At least 289 records · Page 16Linked to original sources

Dietary fiber intake of Japanese younger generations and the recommended daily allowance.

A method was introduced for the estimation of total dietary fiber (TDF) intake of a population using a menu-oriented questionnaire and a menu-based calculation table. TDF intake correlated well with age in a population investigated, and in younger generations TDF consumption was very low (less than 11.5 g/day in teenagers). The similar results were obtained from the calculation using data of National Nutrition Survey (10.7 g/day). The foodstuffs they consumed were more processed and refined. This fact suggested that in younger generations a future resumption of their present eating habits might produce a serious lack of TDF intake in later years. To clarify the optimal level of TDF intake for the upper limit of recommended daily allowance (RDA) of an average Japanese, the following were measured and calculated. (I) Estimation of recent TDF intake (1990) and of 30 and 50 years ago (1955, 1935), based on TDF data of foodstuffs by the enzymatic-gravimetric method. (II) Measurement of the TDF of model duplicate meals and model composite diets for the average Japanese in 1985 using the same assay method. (III) Conversion of a recommendation of 20-35 g/day for American into RDA for Japanese considering energy consumption and lower fat intake. (IV) Re-estimation of the literature data on the adverse effects of DF on the human mineral balance considering the insufficient calcium intake of Japanese. The results indicated an RDA of 10-12 g TDF/1,000 kcal fit better for an average Japanese.

Adolescent↗

Effects of ethanol on the motility of papillary sphincter and exocrine pancreas in the monkey.

The effects of acute and chronic ethanol administration on the motility of the papillary sphincter, pancreatic duct pressures, and exocrine pancreas were studied. Acute administration (n = 5) significantly reduced the peak pressure of the papillary sphincter from 84.2 +/- 19.6 to 15.8 +/- 3.0 mm Hg (p < 0.05) and increased the frequency from 0.041 +/- 0.002 to 0.067 +/- 0.005/s (p < 0.01). Chronic administration (n = 5) significantly increased pancreatic duct pressure and frequency of the papillary sphincter from 8.6 +/- 2.9 to 22.1 +/- 2.9 mm Hg (p < 0.01) and from 0.039 +/- 0.002 to 0.071 +/- 0.004/s (p < 0.01), respectively. However, it reduced the peak pressure of the papillary sphincter from 84.8 +/- 15.1 to 21.1 +/- 2.8 mm Hg (p < 0.05). Electron microscopy showed dilation and a concentric arrangement of the rough endoplasmic reticulum in the acinar cells. The exocrine function test showed an increased concentration and output of bicarbonate, protein, and amylase. These findings suggest that chronic alcohol intake may cause papillary dysfunction and pancreatic exocrine hypersecretion, which could play a role in increasing pancreatic duct pressure.

Amylases↗

[Alternative combination chemotherapy with mitomycin C, vincristine, methotrexate, 5-fluorouracil, cis-platinum and adriamycin for adenocarcinoma of the lung].

Efficacy of an alternative combination chemotherapy with MMC, VCR, MTX, 5-FU, CDDP and ADM for adenocarcinoma of the lung is reported. Forty-one advanced cases (stage III: 9; IV: 32) were chosen for the chemotherapy. Two combination chemotherapies MMC + VCR + MTX + 5-FU + CDDP: MVMFP; MMC + VCR + MTX + 5-FU + ADM: MVMFA were repeated alternatively for 8 consecutive weeks with 2 interposed rest weeks, and this regimen was completed in 34 cases. All 41 cases were evaluable. Three and 26 cases achieved complete and partial responses, respectively. The response rate was 70.7%, and the median survival time was 13 months. The adverse effects of the chemotherapy observed were tolerable: alopecia (63.4%), gastrointestinal symptoms (14.5%), bone marrow toxicity (12.2%) and liver dysfunction (4.8%). These results indicate that our MVMFP/MVMFA alternative chemotherapy is quite effective for adenocarcinoma of the lung, comparable or superior to conventional chemotherapies.

Adenocarcinoma↗

[A case of insulinoma with frequent hypoglycemic attacks not showing evident hyperinsulinemia].

Confirmation of inappropriate hyperinsulinemia is an indispensable requisite for the diagnosis of insulinoma. We report here a case of insulinoma without evident hyperinsulinemia at an early stage. The patient, a 49-year-old woman, had been admitted to our hospital for the evaluation of frequent hypoglycemic attacks. At that time, plasma immunoreactive insulin (IRI) after an overnight fast ranged from 7 to 16 microU/ml. The ratio of IRI/fasting blood sugar (FBS) (Fajans index; normal range, below 0.3) was always between 0.13 and 0.28 even at hypoglycemic states. In addition, because computed tomography and arteriography of the abdomen failed to settle the diagnosis of insulinoma, the patient was discharged and followed up at our outpatient clinic for 2 years. She was admitted to our hospital at 51 years of age for the re-evaluation of hypoglycemic attacks. Laboratory examinations revealed high fasting plasma levels of IRI ranging from 20 to 29 microU/ml. Fajans index also increased to 0.47-0.89. Celiac arteriography was able to confirm the existence of insulinoma. We suggest that insulinoma should be considered in the presence of unexplained hypoglycemic attacks even when there is no evident hyperinsulinemia.

Blood Glucose↗

Full sequence of neurocalcin, a novel calcium-binding protein abundant in central nervous system.

We determined the cDNA sequence for neurocalcin, a novel calcium-binding protein in bovine brain. This clone (pCalN) has 582 nucleotides in the open reading frame including the termination codon TGA, 11 nucleotides of the 5' leader and 1251 nucleotides of the 3' noncoding region. The deduced amino acid sequence revealed that neurocalcin is composed of 193 amino acids, has a molecular mass of 22,284 daltons, and contains three putative calcium-binding sites (EF-hand motifs). By Northern blot analysis, 3.8kbp mRNA was detected in brain. The deduced amino acid sequence had a strong homology to visinin (46.5%) and recoverin (51.6%) in retina, suggesting that neurocalcin may play a visinin- or recoverin-like role in brain.

Amino Acid Sequence↗

Expression of human pituitary adenylate cyclase activating polypeptide (PACAP) cDNA in CHO cells and characterization of the products.

cDNA encoding human PACAP precursor was expressed in non-neuroendocrine Chinese hamster ovary cells, CHO-K1, The cells were transfected with expression vector (pTS705) containing the human PACAP cDNA by electroporation. A cell line which produced more than 80 ng/ml of immunoreactive PACAP (ir-PACAP) into the conditioned medium was established. RP-HPLC analysis of culture medium of this established cell line exhibited the presence of two types of PACAP, i.e. PACAP38 and PACAP27. At the same time, it was also revealed that immunoreactive PACAP-related peptide (ir-PRP) was secreted into the cultured medium. The ir-PACAPs were confirmed to ahve biological activities such as induction of cAMP and neurite outgrowth in rat pheochromocytoma PC12h cells.

Adenylyl Cyclases↗

The 'second-codon rule' and autophosphorylation govern the stability and activity of Mos during the meiotic cell cycle in Xenopus oocytes.

The c-mos proto-oncogene product, Mos, functions in both early (germinal vesicle breakdown) and late (metaphase II arrest) steps during meiotic maturation in Xenopus oocytes. In the early step, Mos is only partially phosphorylated and metabolically unstable, while in the late step it is fully phosphorylated and highly stable. Using a number of Mos mutants expressed in oocytes, we show here that the instability of Mos in the early step is determined primarily by its penultimate N-terminal residue, or by a rule referred to here as the 'second-codon rule'. We demonstrate that unstable Mos is degraded by the ubiquitin-dependent pathway. In the late step, on the other hand, Mos is stabilized by autophosphorylation at Ser3, which probably acts to prevent the N-terminus of Mos from being recognized by a ubiquitin-protein ligase. Moreover, we show that Ser3 phosphorylation is essential for Mos to exert its full cytostatic factor (CSF) activity in fully mature oocytes. Thus, a few N-terminal amino acids are primary determinants of both the metabolic stability and physiological activity of Mos during the meiotic cell cycle.

Amino Acid Sequence↗

Differential occurrence of CSF-like activity and transforming activity of Mos during the cell cycle in fibroblasts.

The Xenopus c-mos proto-oncogene product, Mosxe, possesses cytostatic factor (CSF) activity to arrest maturing oocytes in metaphase II and has weak transforming activity in mouse NIH3T3 cells. We show that Mosxe mutants bearing 'stabilizing' penultimate N-terminal amino acids are strongly transforming and can retard progression through the G2-M phases in Mosxe-transformed cells, probably via their CSF activity. On the other hand, a cyclin-Mosxe fusion protein, which undergoes abrupt degradation at the end of mitosis and is restored to its normal levels only after the G1 phase, transforms cells much less efficiently than a mutated cyclin-Mosxe fusion protein that is stable during M-G1 transition. Moreover, in low-serum medium, cells transformed by the unstable cyclin-Mosxe require a long period to enter the S phase, in contrast with the rapid entry into the S phase of cells transformed by the stable cyclin-Mosxe. These results provide strong evidence that unlike the physiological CSF activity, the transforming activity of Mos is exerted in the G1 phase of the cell cycle.

3T3 Cells↗

A new cdc gene required for S phase entry of Schizosaccharomyces pombe encodes a protein similar to the cdc 10+ and SWI4 gene products.

We have isolated a new cell division cycle gene (res1+) required for entry into S phase, as a multicopy dual suppressor of the pat1 and cdc10 mutants of the fission yeast Schizosaccharomyces pombe. The res1+ gene specifies a 72 kDa protein with two copies of the cdc10/SWI6 motif. A disruptant of res1+ grows poorly at 30 degrees C with severe heat- and cold-sensitivities, and completely arrests in G1 at 36 degrees C and 23 degrees C. The arrested disruptant retains a full conjugation ability. In addition to the cdc10/SWI6 motif, Res1 and SWI4 proteins share a remarkable homology in their amino-terminal region, whereas Cdc10 and SWI6 do so in their carboxy-terminal region. Moreover, the amino-terminal region is essential for the function of Res1 as it is for the function of SWI4. Furthermore, analogous to the relationship of SWI4 to SWI6, the res1+ gene effectively rescues cdc10 mutants, but the cdc10+ gene cannot rescue the res1- phenotype. Thus, striking similarities exist in both structural and functional relationships between Res1 and SWI4, and between Cdc10 and SWI6. In view of the fact that SWI4 and SWI6 form a transcription factor complex and activate promoters containing the SWI4/SWI6 dependent cell-cycle box, Res1 might be a putative association partner of Cdc10 which appears to be involved at least in the activation of promoters containing a MluI cell-cycle box.

Amino Acid Sequence↗

Hypotensive activity of TCV-116, a newly developed angiotensin II receptor antagonist, in spontaneously hypertensive rats.

TCV-116, a recently developed angiotensin II (Ang II) receptor antagonist, was administered orally (1 mg/kg per day) to 10-week-old spontaneously hypertensive rats (SHR) for 2 weeks. Blood pressure and plasma components of the renin-angiotensin-aldosterone system were determined in these rats. TCV-116 produced a marked reduction in blood pressure without altering heart rate. Whereas plasma renin concentration (PRC), angiotensin I (Ang I) and angiotensin II (Ang II) all were significantly increased, plasma aldosterone was decreased by approximately 70% compared with control animals. These results not only indicate therapeutic efficacy of this agent in the chronic treatment of human hypertension, but support also the concept that the renin-angiotensin system plays an important role in the control of blood pressure in this animal model of human essential hypertension.

Angiotensin Receptor Antagonists↗

Expression of mumps virus glycoproteins in mammalian cells from cloned cDNAs: both F and HN proteins are required for cell fusion.

Two recombinant plasmids were constructed by inserting the cDNAs of either the fusion (F) or the hemagglutinin-neuraminidase (HN) protein genes of mumps virus into the pcDL-SR alpha expression vector. Both the F and the HN proteins expressed in COS7 cells transfected with their respective recombinant plasmids were indistinguishable in terms of electrophoretic mobility from their counterparts synthesized in mumps virus-infected cells. The F protein was cleaved and expressed on the cell surface, but uncleaved forms were also detected. The expressed HN protein was transported to the cell surface and adsorbed guinea pig erythrocytes. Syncytium formation was induced when COS7 cells were transfected with both recombinant plasmid DNAs together, but not with the recombinant plasmid only carrying the F gene. This observation indicates that cell fusion mediated by mumps virus requires both the F and the HN glycoproteins.

Animals↗

Molecular cloning and sequence analysis of the mumps virus gene encoding the L protein and the trailer sequence.

We have cloned and determined the nucleotide sequences of the seventh gene of the Miyahara strain of mumps virus (MuV) encoding the L protein. The L gene is 6925 nucleotides in length and contains a single long open reading frame which is capable of coding for a protein of 2261 amino acids with a calculated molecular weight of 256,571 Da. The deduced amino acid sequence of the L protein of MuV showed significant homology with those of six other paramyxoviruses, human parainfluenza type 2 virus, Newcastle disease virus, Sendai virus, measles virus, human parainfluenza type 3 virus, and human respiratory syncytial virus. The predicted MuV L protein contained distinct elements thought to be essential for RNA polymerase activity. A noncoding sequence of 24 nucleotides downstream of the presumed polyadenylation site of the L gene showed significant complementarity with the leader sequence composed of 55 nucleotide at the 3' end of the genomic RNA.

Amino Acid Sequence↗

Synthesis and macromolecular organization of gastrointestinal mucin: evidence for the origin of mucin "link protein".

Mucus glycoproteins (mucins), the principal determinants of mucus protective qualities and mucosal defense, have been studied extensively to define pathological aberrations in relation to gastrointestinal disease. Recent work from our laboratory provided evidence as to the initial stages of gastrointestinal mucin synthesis, the molecular size of the apomucin, and its macromolecular organization. Using monoclonal antibodies (MAbs) against apomucin (clone 1H7), O-glycosylated with N-acetylgalactosamine apomucin (clone 2B4), and that against carboxyl terminal of the apomucin (clone 3G12), the mucin synthesizing polysomes were isolated and glycosylated peptides ranging in size from 6 to 60 kDa identified. In vitro synthesis in a cell-free system also afforded 60- to 64-kDa products recognized by 1H7 and 3G12 antimucin MAbs. The results obtained provided evidence that the mucin core consists of 60-kDa peptide that at the cotranslational stage is O-glycosylated with N-acetylgalactosamine. Studies on mucin polymer assembly revealed that mucin preparations prepared by equilibrium density gradient centrifugation and Sepharose 2B chromatography are not completely purified and contain DNA and extraneous proteins. The evidence was obtained that so-called mucin "link protein", a 118-kDa glycopeptide, is a N-glycosylated fragment of fibronectin, whereas the supposedly native undergraded mucin isolated by Carlstedt et al. was found to contain mucin-fibronectin-DNA complexes. The general picture that emerged from the studies is that the pure mucin consists of 60 kDa glycosylated peptides only. The carboxyl terminal (8- to 12-kDa fragment) of these peptides is not glycosylated (naked) and is responsible for mucin interaction with fibronectin and other fibronectin-like extracellular matrix proteins. Although the formation of the mucosal coat depends on many other factors and extracellular components, our findings on mucin structure and interaction with the extracellular matrix proteins provide an explanation as to the possible mechanism of mucin adherence to the epithelial surfaces.

Antibodies, Monoclonal↗

Sensitization against pancreatic antigen in Sjögren's syndrome and chronic pancreatitis. Preliminary communication.

A fractionated pancreatic antigen was prepared using a monoclonal antibody, SP3-1, which reacts with the duct cells of various exocrine organs. The cell-mediated immune response to this antigen was studied by the leukocyte migration inhibition test (LMT) in patients with chronic pancreatitis (CP), Sjögren's syndrome (SjS), and chronic sialoadenitis (CSA). The migration index (MI) for the LMT was 0.97 +/- 0.07 in normal controls (mean +/- SD, n = 11, range: 0.88-1.08). A positive LMT result (MI less than 0.82 = mean -2 SD in controls) was obtained in 7/8 (88%) SjS patients, 4/22 (18%) CP patients, 2/3 CP patients with SjS, and 0/3 CSA patients. These results indicated sensitization against the pancreatic antigen in most SjS patients and some CP patients, and may suggest that an immune response to a common antigenic determinant of the duct cells of exocrine glands plays a role in the pathophysiology of both diseases.

Antibodies, Monoclonal↗

A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: embolic effect of cisplatin albumin microspheres using chitin and chitosan in dogs, and changes of cisplatin content in blood and tissue.

Hepatic artery of dogs was embolized with cisplatin (CDDP) albumin microspheres containing chitin and chitosan to investigate the in vivo CDDP release kinetics from CDDP albumin microspheres, the CDDP cumulative characteristics in the liver, and the influence of microsphere administration on hepatic tissue. Results showed that changes in blood CDDP content were dependent on CDDP albumin microsphere type and that release kinetics were better sustained when chitin was added to the microspheres or when the microspheres were treated with chitosan. In particular, the administration of CDDP in the chitin-containing CDDP chitosan albumin microspheres showed a blood CDDP content of approximately 0.26 micrograms Pt/ml 14 d after administration. The administration of chitin-containing or chitosan treated CDDP microspheres showed a CDDP content in the hepatic tissue of 0.14 to 0.23 micrograms Pt/g 28 d after administration. They also showed better control of CDDP release than those without chitin or chitosan treatment. No CDDP influence on hepatic tissue was observed. We conclude that, even in vivo, chitin and chitosan are effective embolic materials.

Animals↗

Purification and properties of mycodextranase from Streptomyces sp. J-13-3.

An enzyme hydrolyzing nigeran (alternating alpha-1,3- and alpha-1,4-linked glucan) was purified from the culture filtrate of Streptomyces sp. J-13-3, which lysed the cell wall of Aspergillus niger, by percipitation with ammonium sulfate and column chromatographies on DEAE-Sephadex A-50, CM-Sephadex C-50, chromatofocusing, and Sephadex G-100. The final preparation was homogenous in polyacrylamide gel electrophoresis (PAGE). The molecular weight of the enzyme was 68,000 by SDS-PAGE and gel filtration. The optimum pH and temperature for the enzyme activity were 6.0 and 50 degrees C, respectively. The enzyme was stable in the pH range from 6.0 to 8.0 and up to 50 degrees C. The enzyme activity was inhibited significantly by Hg+, Hg2+, and p-chloromercuribenzoic acid. The Km (mg/ml) for nigeran was 3.33. The enzyme specifically hydrolyzed nigeran into nigerose and nigeran tetrasaccharide by an endo-type of action, indicating it to be a mycodextranase (EC 3.2.1.61) that splits only the alpha-1,4-glucosidic linkages in nigeran.

Carbohydrate Sequence↗