Search PubMed⌕ Search

Biomedical subjects

K Miki

Publications and source records attributed to K Miki.

At least 307 records · Page 17Linked to original sources
PubMed1990

Synthetic oligopeptides bearing a common or subtypic determinant of hepatitis B surface antigen.

Two determinants of hepatitis B surface Ag (HBsAg), identified by mAb raised against polypeptide components, were characterized immunochemically. One was expressed on HBsAg irrespective of the four major subtypes, i.e., adw, adr, ayw, and ayr, whereas the other was subtypic but not identical to any of d, y, w, and r determinants. The common determinant was generated by a synthetic pentadecapeptide with a sequence of Thr-Thr-Ser-Thr-Gly-Pro-Cys-Lys-Thr-Cys-Thr-Ile-Pro-Ala-Gln representing amino acids 115-129 of the S gene product, and detected invariably in 366 HBsAg samples in sera from asymptomatic carriers in Japan. The activity of the S gene product, as well as the peptide (115-129), to bind with the mAb was not affected by alkylation alone, but was completely lost after reductive alkylation. The antigenic activity was lost when the S gene product was severed between Lys122 and Thr123 by trypsin. A microconformation maintained by the -Cys121-Cys124 bond, therefore, would be required for the common determinant. The other mAb identified an epitope of HBsAg that was mimicked by a synthetic tetradecapeptide with a sequence of Thr-Cys-Thr-Ile-Pro-Ala-Gln-Gly-Thr-Ser-Met-Phe-Pro-Ser, representing amino acids 123-136 of the S gene product. Among 16 HBsAg samples with known S gene sequences, 5 with Ile126 possessed this subtypic determinant, but the remaining 11 with Thr126 did not. The 5 hepatitis B virus genomes encoding the subtypic determinant differed less than 5.6% from each other in the entire nucleotide sequence, but by 8.0% or more from any of the other 11 genomes without the capacity to encode it.

Alkylation↗
PubMed1990

GM1 ganglioside reduces edema and monoaminergic neuronal changes following experimental focal ischemia in rat brain.

Seventy-two hours following a middle cerebral artery occlusion, the associated increase in water content on the ischemic side was significantly reduced by the exogenous administration of monosialoganglioside GM1 (30 mg/kg, i.p.). The levels of dopamine and serotonin on the ischemic side were approximately 50% and 80% of those on the contralateral non-ischemic side, respectively. Treatment with GM1 (5 times during the first 48 h after occlusion) produced a significant reduction in the levels of dopamine and serotonin loss. The present findings are compatible with the observed protective action of the exogenously administered GM1 following ischemic brain injury.

Animals↗
PubMed1990

Structural studies of rat cathepsin E: amino-terminal structure and carbohydrate units of mature enzyme.

The amino-terminal structure of rat gastric cathepsin E was identified and compared with the corresponding regions of human procathepsin E and other aspartic proteinases. The alignment revealed that cathepsin E has the most extended amino-terminal structure in aspartic proteinases, thus suggesting that the activation peptide (propeptide) of the human enzyme is 39-residues long. Analysis of oligosaccharide units suggested that rat cathepsin E possesses one N-linked carbohydrate unit, probably of the high mannose type. No evidence was obtained for the presence of O-linked sugars in rat cathepsin E.

Amino Acid Sequence↗
PubMed1990

Double cardia. An unusual sequela of reflux esophagitis with ulcer.

We report a patient with acquired "double cardia" (esophagogastric fistula). She was a 76-year-old farmer's widow with severe kyphosis. She presented with postprandial heartburn one month after the initiation of nifedipine and isosorbide dinitrate. Radiologic and endoscopic examinations revealed an esophagogastric fistula, short esophagus with hiatal hernia, Barrett's esophagus with reflux esophagitis, and ulcer. This case shows that repeated reflux esophagitis and esophageal ulcer, complicated with short esophagus and hiatal hernia, can predispose to the formation of esophagogastric fistula.

Aged↗
PubMed1990

Crystallization and preliminary X-ray diffraction studies of C-phycocyanin from a red alga, Porphyra tenera.

C-Phycocyanin from a red alga, Porphyra tenera, has been crystallized by the vapor-diffusion procedure. Both orthorhombic and hexagonal forms were obtained from ammonium sulfate solutions, whereas only the orthohombic form was selectively grown from sodium citrate solutions. The orthorhombic crystals are more suitable for further crystallographic work; their space group is P2(1)2(1)2(1), with unit-cell dimensions of a = 105, b = 121, and c = 184 A. The asymmetric unit comprises two (alpha beta)3 trimer molecules of C-phycocyanin. These crystals diffract X-rays up to about 3 A resolution.

Diffusion↗
PubMed1990

Partial cDNA cloning of the 230-kD mouse bullous pemphigoid antigen by use of a human monoclonal anti-basement membrane zone antibody.

A cDNA clone with the coding sequence for the 230-kD bullous pemphioid (BP) antigen was isolated from a mouse cDNA expression library by using an anti-basement membrane zone human monoclonal antibody (MoAb-5E). The lambda gt11 cDNA expression library was constructed from poly(A)+RNA from the mouse epidermal cell line, Pam cells, by random priming. 1.5 X 10(5) recombinant clones were screened by immunostaining with MoAb-5E and one positive clone (BPM1) was obtained. All of the ten BP sera but none of the five normal or seven pemphigus sera tested reacted with the fusion protein produced by BPM1. The size of the cDNA was 3.2 kb. Northern blot analysis indicated that BPM1 cDNA hybridized to a mRNA of about 9 kb, which is large enough to encode for a 230-kD protein. DNA sequencing demonstrated a 2,991-bp open reading frame encoding a peptide of 115 kD. Sequence comparison between mouse and human cDNA clones revealed that the 230-kD BP antigen was well conserved during evolution except for the carboxyl terminus. Highly conserved and hydrophilic regions in the molecule were considered to be good candidates for antigenic determinants. This cDNA clone will be useful not only for diagnosis of BP, e.g., enzyme-linked immunosorbent assay using recombinant proteins or synthetic peptides as antigens, but also for pathophysiologic study in which mouse models of BP might be used.

Amino Acid Sequence↗
PubMed1990

Gastric and intestinal phenotypic expression of human stomach cancers as revealed by pepsinogen immunohistochemistry and mucin histochemistry.

Gastric and intestinal phenotypic expression in 223 surgically obtained primary gastric cancers and their histogenetic relationship to intestinal metaplasia in the surrounding gastric mucosa were studied by mucin histochemistry and pepsinogen (Pg) immunohistochemistry. Histochemical differentiation of mucins (paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase-galactose oxidase-Schiff) and immunohistochemical staining of Pgs I and II, allowed differentiation of gastric cancer cells from different histological categories into gastric elements including mucous neck cells, pyloric gland cells and surface mucous cells or intestinal elements including goblet cell and intestinal absorptive cell types. Of 122 papillary and tubular adenocarcinomas, 33 (27.1%) consisted mainly of gastric-type cells and 42 (34.4%) predominantly of intestinal-type cells. The remainder (38.5%) consisted of mixtures of gastric- and intestinal-type cells. Of 101 poorly differentiated adenocarcinomas, signet ring cell carcinomas and mucinous adenocarcinomas, 59 (58.4%) consisted mainly of gastric-type cells and 20 (19.8%) mainly of intestinal-type cells. Seven out of 35 papillary and tubular adenocarcinomas consisting mainly of gastric-type cancer cells were surrounded by mucosa with intestinal metaplasia. Conversely, 10 out of 40 papillary and tubular adenocarcinomas consisting mainly of intestinal-type cancer cells were observed in nonmetaplastic gastric mucosa. Thus no relationship as regards intestinal phenotypic expression was found between gastric cancers and surrounding gastric mucosa.

Histocytochemistry↗
PubMed1990

[Identification of acinetobacter species isolated from human infections based on a new classification by Bouvet and Grimont].

The genus Acinetobacter was recently re-classified by Bouvet and Grimont who described four new species, A. baumannii, A. haemolyticus, A. johnsonii and A. junii, and five unnamed genospecies, with a re-definition of A. calcoaceticus and A. lwoffii which appeared in the Approved Lists of Bacterial Names, 1980. One hundred and twenty-eight clinical isolates previously identified as Acinetobacter were retrieved from storage and re-characterized by using a system based on the grouping reactions described by Bouvet and Grimont. Of these 86.7%, 2.3%, and 1.6% were identified as A. baumannii, A. junii and Acinetobacter genospecies 11, respectively, and the remaining 9.4% of the cultures were unidentified. None of the cultures identified as A. calcoaceticus and A. lwoffii was included in the 128 cultures.

Acinetobacter↗
PubMed1990

Cardiovascular, renal, and endocrine responses in male quadriplegics during head-out water immersion.

The present study was undertaken to determine the relative influence of the action of the central nervous system on the mechanism of water-immersion-induced diuresis by comparing physiological responses of quadriplegic (QP) and normal subjects. After overnight fasting seven male QP subjects with complete cervical cord transections (C5-C8) and six normal men were tested before, during, and after 3 h of head-out immersion (HOI) in thermoneutral water (34.5-35.0 degrees C). The reversible increase in urine flow and the total urine volume (309 +/- 53 ml in 3 h) in QP subjects were comparable with that of the normal subjects (318 +/- 96 ml in 3 h). While osmolal excretion was increased in QP subjects, its magnitude was less when compared with that of normal subjects. Instead, the increased urine flow in QP subjects was characterized by increased glomerular filtration rate (GFR) and free water clearance, in contrast to a predominantly osmotic diuresis with no changes in GFR in the normal subjects. The HOI elevated (P less than 0.05) systolic pressure only in QP subjects, whereas the increase in cardiac output was the same in both groups. While plasma renin activity and aldosterone responses to HOI in QP subjects were comparable with those of normal individuals, plasma atrial natriuretic factor (ANF) in QP subjects was twofold higher (P less than 0.05) during HOI, and the approximately threefold increase in ANF (P less than 0.05) in QP subjects due to HOI was the same as that of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Changes in insulation of body tissue and wet suits during underwater exercise at various atmospheric pressures.

To clarify the independent changes of insulations of body tissues (Itissue) and wet suit (Isuit) in the wet-suited subject during underwater exercise, overall heat flow from the skin (Htissue) and wet suit (Hsuit) and esophageal (Tes), skin (Tsk), and wet suit temperatures were measured at 1, 2, and 2.5 atmospheres absolute (ATA) at critical water temperature (Tcw). The average Tcw in nine wet-suited men (23-38 yr) was 22.3 +/- 0.2, 26.3 +/- 0.2, and 28.0 +/- 0.4 degrees C (SE) at 1, 2, and 2.5 ATA, respectively. At Tcw of each pressure male volunteers wearing 5-mm neoprene wet suits completed three 2-h experiments while immersed up to the neck. During one experiment the subjects remained at rest, and in the other two they exercised on an underwater ergometer at two different intensities (2 and 3 met). Tes significantly declined (P less than 0.05) over 2 h from 37.1 to 36.5 degrees C during rest in each pressure. The 2-met exercise prevented Tes from falling in all pressures, and the 3-met exercise elevated Tes by 0.2-0.3 degrees C. There was no exercise-dependent difference in Isuit, but a pressure-dependent difference was remarkable. The Itissue at rest was identical for all pressures; however, it progressively decreased as a function of exercise intensity. It is concluded that overall Itissue is entirely determined by work intensity at Tcw, but not by atmospheric pressure. On the contrary, Isuit at Tcw is solely dependent on the pressure, but not on the work intensity.

Adult↗
PubMed1990

Induction of neutralizing antibodies against bovine leukosis virus in rabbits by vaccination with recombinant vaccinia virus expressing bovine leukosis virus envelope glycoprotein.

Three kinds of recombinant vaccinia virus (RVV)--mO-HA/ATI, LO1-HA/ATI and mO-HA/7.5kD--expressing bovine leukosis virus (BLV) envelope glycoprotein (gp60) were constructed. The BLV envelope gene of RVV mO-HA/ATI and LO1-HA/ATI or of RVV mO-HA/7.5kD was expressed under control of the promoter of A-type inclusion body (ATI) protein gene of cow-pox virus or vaccinia virus 7.5-kD protein gene, respectively. The vaccinia virus strain, LC16mO, was used as vector for RVV mO-HA/ATI and mO-HA/7.5kD, and strain LO-1 was used for RVV LO1-HA/ATI. Strains LC16mO and LO-1 are attenuated vaccine virus strains originating from the Lister original vaccinia virus. All 3 kinds of constructed RVV expressed gp60 in cultured rabbit kidney cells after infection; mO-HA/ATI expressed more antigen than did mO-HA/7.5kD. Rabbits vaccinated with RVV produced considerable antibody capable of inhibiting syncytium formation, as well as antibody with virion-binding ability. The RVV that used ATI promoter induced higher antibody titer than did the RVV that used 7.5-kD promoter. Results indicate that BLV gp60 is responsible for induction of neutralizing antibodies that suppress in vitro formation of syncytia among BLV-infected cells. Applicability of RVV, especially those using ATI promoter, was evaluated in a vaccine against bovine leukosis.

Animals↗
PubMed1989

The complete sequence of soybean chlorotic mottle virus DNA and the identification of a novel promoter.

The complete nucleotide sequence of an infectious clone of soybean chlorotic mottle virus (SoyCMV) DNA was determined and compared with those of three other caulimoviruses, cauliflower mosaic virus (CaMV), carnation etched ring virus and figwort mosaic virus. The double-stranded DNA genome of SoyCMV (8,175 bp) contained nine open reading frames (ORFs) and one large intergenic region. The primer binding sites, gene organization and size of ORFs were similar to those of the other caulimoviruses, except for ORF I, which was split into ORF Ia and Ib. The amino acid sequences deduced from each ORF showed only short, highly homologous regions in several of the corresponding ORFs of the three other caulimoviruses. A promoter fragment of 378 bp in SoyCMV ORF III showed a strong expression activity, comparable to that of the CaMV 35S promoter, in tobacco mesophyll protoplasts as determined by a beta-glucuronidase assay using electrotransfection. The fragment contained CAAT and TATA boxes but no transcriptional enhancer signal as reported for the CaMV 35S promoter. Instead, it had sequences homologous to a part of the translational enhancer signal reported for the 5'-leader sequence of tobacco mosaic virus RNA.

Amino Acid Sequence↗
PubMed1989

[Giant renal cell carcinoma: a case report].

Though renal cell carcinoma is a fairly common disease, it is extremely rare to encounter a case providing a resected mass as large as over 2,000 g in weight. We report a case in which a giant 2,200 g tumor was resected after renal arterial embolization and interferon treatment for reduction of its size. A forty-three-year-old woman was first seen at a certain hospital with a chief complaint of fever and right flank pain. Under suspicion of right renal tumor, nephrectomy by extraperitoneal flank incision was attempted. However, the tumor was too large to be resected. After transfer to our department, she was treated by renal arterial embolization with absolute ethanol and steel coil and by the administration of interferon (rIFN-alpha A). As the tumor shrank to 77% of its original size on CT measurements and became mobile, transperitoneal nephrectomy was performed. The resected mass was as large as 12 x 12 x 21 cm. Pathologically, it was a clear cell type tumor showing mucinous degeneration and hyaline degeneration of tumor cells. Interferon used amounted to as high as 864 x 10(6) units, but no particular side effect occurred. No recurrence has been detected so far.

Adult↗
PubMed1989

Changes in limb volume during head-out water immersion in humans.

In order to investigate the contribution of fluid shift from the legs to immersion-induced diuresis, 7 normal and 2 legless (both legs disarticulated at the hip) individuals were tested to measure changes in leg volume (normal subjects) and urinary excretion of solutes and water during a 3-h head-out water immersion (HOI) in thermoneutral water (34.5 +/- 0.5 degrees C) with a 1-h control period before and after immersion. On a separate day, a 5-h time control (TC) experiment on the same subjects was carried out by having them sit in thermoneutral air (29 +/- 0.1 degrees C, relative humidity 60%). The leg volume decreased by 192 +/- 20 ml during the 3-h HOI, which accounted for 3.5% of the average leg volume of the preimmersion period. During TC, however, the leg volume increased by 110 ml in the same time course. An increase in urine volume and sodium excretion was observed during HOI in both normal (P less than 0.05) and legless subjects. Net urine volume induced by HOI (urine volume during HOI minus urine volume during corresponding TC) in normal subjects was 494 +/- 89 ml in 3 h, which was close to a calculated volume reduction of the lower extremities during HOI (508 +/- 53 ml). The average net urine volume during HOI in the legless subject was 183 +/- 48 ml/min. The above results may suggest that the increase in renal water output is largely accounted for by a fluid shift from the lower extremities during HOI, however, the fluid other than that from the extremities should be accounted for as the urine source.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

In vitro and in vivo antagonists against parathyroid hormone-related protein.

Four analogues of parathyroid hormone-related protein (PTHrP), PTHrP(7-34)NH2, (10-34)NH2, (15-34)NH2 and (20-34)NH2, were synthesized and their antagonistic activity against PTHrP(1-34) was examined in vitro and in vivo. In vitro studies revealed that all four analogues antagonized PTHrP-stimulated cyclic AMP production in rat osteosarcoma cells (ROS 17/2.8), and that PTHrP(7-34)NH2 and PTHrP(10-34)NH2 had potent antagonistic activity. In vivo experiments in nude mice also revealed that PTHrP(7-34)NH2 completely inhibited hypercalcemia induced by PTHrP(1-34), indicating that these analogues antagonize the effects of PTHrP(1-34) in vitro and in vivo.

Adenylyl Cyclases↗
PubMed1989

Closed and continuous algae cultivation system for food production and gas exchange in CELSS.

In CELSS (Controlled Ecological Life Support System), utilization of photosynthetic algae is an effective means for obtaining food and oxygen at the same time. We have chosen Spirulina, a blue-green alga, and have studied possibilities of algae utilization. We have developed an advanced algae cultivation system, which is able to produce algae continuously in a closed condition. Major features of the new system are as follows. (1) In order to maintain homogeneous culture conditions, the cultivator was designed so as to cause a swirl on medium circulation. (2) Oxygen gas separation and carbon dioxide supply are conducted by a newly designed membrane module. (3) Algae mass and medium are separated by a specially designed harvester. (4) Cultivation conditions, such as pH, temperature, algae growth rate, light intensity and quantity of generated oxygen gas are controlled by a computer system and the data are automatically recorded. This equipment is a primary model for ground experiments in order to obtain some design data for space use. A feasibility of algae cultivation in a closed condition is discussed on the basis of data obtained by use of this new system.

Biomass↗