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Biomedical subjects

H Ohkubo

Publications and source records attributed to H Ohkubo.

At least 91 records · Page 5Linked to original sources
PubMed1989

Visual field in hysteria-reliability of visual field by Goldmann perimetry.

Four cases with hysterical amblyopia in youngsters under 15-year-old showed the poor reproducibility of visual field, that is, when the same target was moved from the periphery toward the fixation ten times along the same meridian during the same examination, the position of the plotted points were rather variable. The range of variation was measured from the innermost point to the outermost one, after the two first points were omitted because points first detected were usually far from the others. The variation of cases measured by this method was compared with that of normal persons. Results were as follows; 1. in normal person, the mean value of its range was 5.5 degrees in first decade and 4.2 degrees in second to seventh decade; 2. patients with psychogenic visual disturbances showed a variability of 14.2 degrees, and this was significantly different from normal (p less than 0.01). These results suggest that this convenient method was helpful for diagnosis of hysteria. It should also be remembered that when we evaluate the visual field, changes under 4 degrees are probably not significant.

Adolescent↗
PubMed1989

Vascular responses of ophthalmic arteries to exogenous and endogenous norepinephrine.

A participation of neuronal and tissue uptake mechanism in responses to periarterial electrical sympathetic nerve stimulation (ES) and intra-arterial applications of norepinephrine (NE) was investigated in the isolated and perfused canine ophthalmic arteries (OA), using key pharmacological drugs such as imipramine, tyramine, cocaine, cortisol and diltiazem. Results were as follows: (1) NE, KCl and ES induced marked vasoconstrictions in a dose- and frequency-related manner, but tyramine induced only a slight constriction even at large doses; (2) cortisol, an uptake2 blocker, did not significantly modify KCl- and ES-induced vasoconstrictions, but significantly enhanced NE-induced responses; (3) small doses of imipramine, a neuronal uptake1 blocker, did not modify NE-induced vasoconstrictions, but large doses decreased them. On the other hand, the ES-induced response was slightly increased by a relative small dose of imipramine; (4) cocaine, another uptake1 blocker, slightly enhanced NE- and ES-induced responses; (5) ES-induced response was reduced by not only diltiazem, but also Ca2+-free solution with EGTA (1 mM l-1). The NE-induced response was not affected by diltiazem (Ohkubo and Chiba, 1987, Exp. Eye Res. 45, 263-70), and slightly but significantly depressed by Ca2+-free solution with EGTA. These results suggest that tissue and neuronal uptake mechanisms exist in responses to ES and NE1, the response to ES was markedly dependent on Ca2+ influx to the cell membrane2, and exogenous NE may induce Ca2+ movement mainly from the intracellular store site.

Animals↗
PubMed1989

Isolation, sequence, and bacterial expression of a cDNA for (S)-tetrahydroberberine oxidase from cultured berberine-producing Coptis japonica cells.

cDNA clones for the (S)-tetrahydroberberine (H4Ber) oxidase of cultured berberine-producing Coptis japonica cells were isolated by screening a C. japonica cDNA library with synthetic nucleotides that can encode the NH2-terminal sequence of this enzyme. Analyses of the nucleotide sequences of the cloned cDNA inserts revealed a 759-base-pair open reading frame that encoded a 253-amino acid polypeptide with a Mr of 27,089 and NH2-terminal and internal sequences identical with those of the (S)-H4Ber oxidase, as determined by microsequencing methods. Escherichia coli were transformed with an expression vector carrying (S)-H4Ber oxidase cDNA. The transformed bacteria were induced to overproduce a 28-kDa protein that reacted with Coptis (S)-H4Ber oxidase-specific antibody. A comparison of the derived amino acid sequence of (S)-H4Ber oxidase with sequences in the protein data base of the Protein Research Foundation showed a marked similarity between (S)-H4Ber oxidase and the NH2-terminal portion of mouse P1-450, which is encoded by a single exon of the mouse P1-450 gene. The availability of cloned cDNA for (S)-H4Ber oxidase allows use of the methods of molecular biology to study the regulation of (S)-H4Ber oxidase gene expression in cultured C. japonica cells in relation to berberine biosynthesis.

Amino Acid Sequence↗
PubMed1989

[Epidemiological aspects of enteritis due to Campylobacter jejuni].

From September 1986 through July 1987, all fecal specimens obtained from infants and children who visited the pediatric clinic of the Shizuoka General Hospital with complaints of abdominal pain or diarrhea were examined for thermophilic Campylobacters. Bacteriological and epidemiological studies were performed on household contacts. The mothers of the patients were compared with the mothers of age-matched control subjects. Bacteriological examination of animals in 49 primary schools in Shizuoka city was performed. C. jejuni was isolated from 47 (9.4%) of the 499 feces samples, occupying first place in the bacterial etiology of acute bacterial enteritis. Infants and young children below 10 years of age comprised 81% of the total cases. Fourteen (13%) strains of C. jejuni were isolated in 9 families among 105 household contacts of the index patients. Six symptomatic contacts in two households had eaten the same suspected chicken as the respective index patients. In three families, C. jejuni was isolated from the remainder of the chicken. The serotype of these isolates was identical to that of the isolates from the index cases and the other family members. It was also noted that the same chopping boards were used for the preparation of salads after cleansing with water. In two index cases, the antibody of convalescent serum against C. jejuni isolated from the chicken, as estimated by passive hemagglutination method, ranged from 1:320 to 1:1280. These facts strongly supported the assumption that they had been infected by the chicken. The remaining persons were asymptomatic and the possibility was left that the index cases had been secondarily infected by these carrier persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Clinical and histological effects of cis-platinum-peplomycin chemotherapy for metastatic lymph nodes of head and neck cancer].

Clinical and histological effects of cis-platinum-peplomycin chemotherapy for metastatic lymph nodes were studied in 35 head and neck carcinomas. The results were as follows; 1. As the clinical effects, 4 cases revealed CR, 17 cases PR, and 16 cases NC. The response rate was 57%. 2. Histologically, 7 cases were classified as Grade III change, 1 case as Grade IIb change and 13 cases as Grade IIa change according to Ohboshi-Shimozato classification. 3. The clinical effects for the metastatic lymph nodes almost agreed to that for the primary lesion. 4. The histological effects for the metastatic lymph nodes almost agreed to that for the primary lesion. 5. The clinical effects for the metastatic lymph nodes did not always agree to the histological effects for it. 6. It was impossible to do radical treatment of metastatic lymph nodes with cis-platinum-peplomycin chemotherapy. In some cases, chemotherapy made it easy to do radical neck dissection.

Adult↗
PubMed1989

[Clinical evaluation of cefodizime in children].

Cefodizime (THR-221, CDZM), a new parenteral cephalosporin, was evaluated for its efficacy and safety in 20 children with bacterial infections (Table 1), and the following results were obtained. 1. CDZM was administered in 3 or 4 divided doses at daily dosages ranging from 54.5 to 84.2 mg/kg administered by 30 minutes drip infusion or intravenous injection to 20 patients (7 cases of acute tonsillitis, 6 cases of pneumonia, 2 cases each of bronchitis and suppurative cervical lymphadenitis, and 1 case each of acute pharyngitis, acute enteritis and furunculosis) and the following clinical results were obtained: excellent, 7 cases; good, 11 cases; fair, 2 cases. The overall efficacy rate was 90% (Table 4). 2. MICs of CDZM against 15 strains of isolated organisms are shown in Table 2. MICs against all 7 strains of Haemophilus influenzae were less than 0.025 micrograms/ml. MIC against 1 out of 5 strains of Streptococcus pneumoniae was 0.05 micrograms/ml and those against 2 strains were 0.10 micrograms/ml and against the other 2 were 0.20 micrograms/ml. MICs against 3 strains of Staphylococcus aureus were 1.56, 25 and higher than 100 micrograms/ml, respectively. 3. No clinical adverse reaction was observed in any of the 20 patients. Eosinophilia was observed in 2 cases. A slight elevation of S-GOT was found in 1 patient (case No. 8) and moderate elevation of S-GOT and S-GPT in another (case No. 18) (Table 4). In case No. 18, the S-GOT and S-GPT activity improved after the administration of the drug was stopped.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

Cloning and sequence analysis of cDNA encoding a precursor for porcine brain natriuretic peptide.

Brain natriuretic peptide (BNP) is a new type of natriuretic peptide recently identified in porcine brain. Since the highest concentration of BNP was found in the cardiac atrium, the cDNA library of porcine cardiac atrium was constructed, and the cDNA clone encoding a BNP precursor was isolated and sequenced. The precursor for porcine BNP (porcine prepro-BNP) is 131 amino acids in length, including a 25 residue putative signal peptide at the N-terminus. Porcine BNP structure is located at the C-terminus of the precursor and is directly followed by a termination codon. Based on structural data recently obtained for gamma-BNP (a main storage form of BNP in the heart), prepro-BNP is processed to 106-residue gamma-BNP by removal of the signal peptide in the heart, and to low molecular weight forms, such as BNP-26 and BNP-32, in the brain.

Amino Acid Sequence↗
PubMed1988

Cloning of a membrane protein that induces a slow voltage-gated potassium current.

A rat kidney messenger RNA that induces a slowly activating, voltage-dependent potassium current on its expression in Xenopus oocytes was identified by combining molecular cloning with an electrophysiological assay. The cloned complementary DNA encodes a novel membrane protein that consists of 130 amino acids with a single putative transmembrane domain. This protein differs from the known ion channel proteins but is involved in the induction of selective permeation of potassium ions by membrane depolarization.

Amino Acid Sequence↗
PubMed1988

Structure of the rat renin gene.

We have isolated the renin gene from a Sprague-Dawley rat genomic library and determined its complete nucleotide sequence. The single rat renin gene is approximately 11,000 bases in length and consists of nine exons and eight introns. The amino acid sequence predicted from the genomic sequence indicates that the rat renin precursor consists of 402 amino acid residues, and shows 85%, 82% and 68% homology to the mouse Ren-1 and Ren-2, and human renins, respectively. The canonical promoter "TATA" boxes, TATAAA and TAATAA, are found 27 and 57 base-pairs upstream from the putative cap site, respectively. Several attractive regulatory sequences analogous to glucocorticoid, estrogen receptor-binding sites, cAMP-responsive element and SV40 enhancer core sequences were noted in the 5'-flanking region of the gene. In the first intron, segments with an average size of 38 base-pairs containing a NcoI site are present at 46 tandem repeats within 1710 base-pairs. A "CA" element consisting of (CA)27 was identified in intron 3. Furthermore, intron 8 contains a sequence that shows about 93% homology to that of the neuronal identifier sequence.

Amino Acid Sequence↗
PubMed1988

Angiotensinogen gene expression in extrahepatic rat tissues: application of a solution hybridization assay.

Angiotensin II has numerous biological effects in a hitherto unsuspected variety of tissues. The generation of angiotensin in tissue requires the local presence of its high molecular weight precursor angiotensinogen and is best tested by investigating angiotensinogen gene expression. A quantitative solution hybridization assay for rapid and sensitive measurement of angiotensinogen mRNA was therefore established to study the extrahepatic expression of the angiotensinogen gene. We used a 714 bases BamHI angiotensinogen cDNA fragment cloned into vector pSPT18 and developed a sensitive and rapid assay with a detection limit of 0.5 pg RNA. Quantification of angiotensinogen mRNA from male Sprague-Dawley rats resulted in the following tissue levels (n = 10 for all tissues, except pituitary where n = 5), was expressed as fg mRNA per microgram total RNA, in descending order: liver (9950), hypothalamus (6050), midbrain (4450), brainstem (3950), total brain (2325), aorta (625), kidney (338), adrenal gland (170), and heart atrium (140). The high sensitivity of the assay in addition also allowed for the first time measurement of angiotensinogen mRNA in the low gene expression tissues pituitary (70), heart ventricle (30), and testis (30). This assay will allow detailed studies on the regulation of tissue angiotensinogen and the pathophysiological role of the tissue renin angiotensin systems.

Adrenal Glands↗
PubMed1988

Measurement of multidrug-resistance messenger RNA in urogenital cancers; elevated expression in renal cell carcinoma is associated with intrinsic drug resistance.

We measured the levels of messenger RNA of the human multidrug-resistance gene (MDR1) in 25 urogenital tumors before chemotherapy. Many of the renal cell carcinomas continued to express MDR1 gene at high levels, reflecting the increased expression of MDR1 RNA in normal kidneys. In other urogenital tumors, the MDR1 RNA levels were low reflecting low MDR1 RNA levels in normal bladder, prostate and testis. For comparative purposes, we performed in vitro chemosensitivity testing on many tumor samples using soft agar culture techniques. Vinblastine sensitivity in vitro inversely correlated with MDR1 RNA levels (p less than 0.01). Moreover, mean sensitivity of seven renal cell carcinomas to vinblastin was significantly lower than that of the other seven cancers (p less than 0.05). As for doxorubicin, mean sensitivity of six renal cell carcinomas was lower than the others (p less than 0.1). These results suggest that the high MDR1 RNA levels in renal cell carcinomas are associated with intrinsic multidrug-resistance.

Carcinoma, Renal Cell↗
PubMed1988

Structural similarity of bovine lung prostaglandin F synthase to lens epsilon-crystallin of the European common frog.

Cloned cDNA sequences specific for prostaglandin F (PGF) synthase have been isolated from a cDNA library of bovine lung mRNA sequences. Nucleotide-sequence analyses of cloned cDNA inserts have revealed that PGF synthase consists of a 969-base pair open reading frame coding for a 323-amino acid polypeptide with a Mr of 36,666. The sequence analysis indicates that bovine lung PGF synthase shows 62% identical plus conservative substitutions compared with human liver aldehyde reductase [Wermuth, B., Omar, A., Forster, A., Francesco, C., Wolf, M., Wartburg, J.P., Bullock, B. & Gabbay, K.H. (1987) in Enzymology and Molecular Biology of Carbonyl Metabolism: Aldehyde Dehydrogenase, Aldo-Keto Reductase, and Alcohol Dehydrogenase, eds. Weiner, H. & Flynn, T.G. (Liss, New York), pp. 297-307], which is similar to PGF synthase in molecular weight and substrate specificity. However, comparison of the amino acid sequence of PGF synthase with the National Biomedical Research Foundation protein data base reveals that the sequences of 225 amino acids from C termini of epsilon-crystallin of the European common frog (Rana temporaria) [Tomarev, S.I., Zinovieva, R.D., Dolgilevich, S.M., Luchin, S.V., Krayev, A.S., Skryabin, K.G. & Gause, G.G. (1984) FEBS Lett. 171, 297-302] and of PGF synthase show 77% identical and conservative substitutions without deletions/additions. The result suggests that European common frog lens epsilon-crystallin is identical to bovine lung PGF synthase.

Aldehyde Oxidoreductases↗
PubMed1988

Induction of angiotensinogen mRNA in hepatocytes by angiotensin II and glucocorticoids.

In isolated rat hepatocytes, exposed to angiotensin II and glucocorticoids, angiotensinogen mRNA increased within 30-60 min, and angiotensinogen secretion with a time lag of about 2 hours. After 4 hours, angiotensinogen mRNA, estimated by liquid hybridization with radiolabeled cRNA, was 5.9 +/- 0.4 in control, and 10.8 +/- 0.8, 11.7 +/- 0.4, 16.1 +/- 0.8 and 21.7 +/- 0.2 pg/micrograms of total RNA in cells exposed to angiotensin II (9 nM and 90 nM), hydrocortisone (100 microM) and dexamethasone (10 microM) respectively. The corresponding secretion rates of angiotensinogen were 72 +/- 7, 124 +/- 4, 132 +/- 12, 220 +/- 19 and 217 +/- 18 fmol angiotensinogen/mg wet weight/hour. Thus, angiotensin II stimulates angiotensinogen synthesis and secretion by acting at a pretranslational site.

Angiotensin II↗
PubMed1988

Effect of changes in sodium balance on renin, angiotensinogen and atrial natriuretic factor messenger RNA levels in rats.

The expression of messenger (m)RNA for renin, angiotensinogen and atrial natriuretic factor (ANF) was investigated in rats on different sodium intakes. Messenger RNA was measured by a radiodensitometric hybridization assay. In the high-sodium state, renal renin mRNA decreased, but it increased in the low-sodium state. A further increase in renin mRNA was seen in the low-sodium state after captopril administration. Angiotensinogen mRNA levels in the liver, kidney and brain were altered by varying sodium intake. In the high-sodium state angiotensinogen mRNA decreased, but in the low-sodium state it increased. After treatment with captopril, angiotensinogen mRNA levels decreased in the liver and kidney. Angiotensinogen mRNA showed tissue specificity for expression, especially in the brain. Atrial ANF mRNA levels changed slightly with different levels of sodium intake.

Angiotensinogen↗
PubMed1988

Angiotensin II controls angiotensinogen secretion at a pretranslational level.

It has been proposed that feedback by angiotensin II, the effector peptide of the renin-angiotensin system stimulates hepatic angiotensinogen synthesis, since long-term infusion of this octapeptide in vivo induced an increase in plasma angiotensinogen concentrations. In the present study, the effects of angiotensin II (9 and 90 nmol/l) on angiotensinogen messenger (m)RNA concentrations and on angiotensinogen secretion of freshly isolated rat hepatocytes were compared with those of glucocorticoids (hydrocortisone, 10(-4) mol/l, and dexamethasone, 10(-5) mol/l). Angiotensin II and the glucocorticoids elevated angiotensinogen mRNA concentrations two- to threefold. Angiotensinogen secretion rates were correspondingly increased with a time lag of about 2 h. Differences in the time-course of changes in mRNA following onset or decay of the hormonal effect suggest that angiotensin II and glucocorticoids express their effects by different intracellular mechanisms. This view is supported by the observation that angiotensin II but not dexamethasone has a stabilizing effect on angiotensinogen mRNA, when further synthesis was blocked by actinomycin D.

Angiotensin II↗