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Biomedical subjects

H Ohi

Publications and source records attributed to H Ohi.

At least 19 recordsLinked to original sources
PubMed1997

Cloning and sequence analysis of a Bothrops jararaca cDNA encoding a precursor of seven bradykinin-potentiating peptides and a C-type natriuretic peptide.

A 1.8-kb cDNA clone was isolated from a Bothrops jararaca venom gland cDNA library that encodes a 256-aa precursor for bradykinin-potentiating peptides (angiotensin-converting enzyme inhibitors) and a C-type natriuretic peptide (CNP). The seven bradykinin-potentiating peptides are aligned tandemly after the hydrophobic signal peptide sequence, followed by a putative intervening sequence and a CNP at the C terminus. Northern blot analysis indicated the predominant expression of a 1.8-kb mRNA in the venom glands as well as in the spleen and the brain. Two lower intensity mRNA bands of 3.5 kb and 5.7 kb also hybridized to the cDNA clone. Radioimmunoassay for the CNP was performed using the antiserum against rat CNP. The presence of CNP immunoreactivity was detected in the low molecular weight fraction of the Bothrops jararaca venom.

Amino Acid Sequence↗
PubMed1997

Hemispatial sunglasses: effect on unilateral spatial neglect.

OBJECTIVE: To investigate whether using glasses shaded on the non-neglected side would lead to less unilateral neglect during pencil-and-paper activities. DESIGN: Descriptive study of ten patients. One remarkable case is described in detail. SETTING: Rehabilitation medicine department in an urban general hospital. PATIENTS: Ten hemiplegic patients showing left unilateral neglect during pencil-and-paper activities. INTERVENTION: Use of glasses in which the right half of each lens was shaded by a darker lens like those used in sunglasses. MAIN OUTCOME MEASURES: For unilateral neglect: (1) deviation from marking the middle of a 20-cm horizontal line; (2) number of lines left unmarked on the left hand portion of a page of 40 randomly oriented lines; (3) degree of failure to copy a representation of a cube. RESULTS: Among the ten patients, improvement was mixed for each of the three outcome measures. One patient, however, demonstrated dramatic and lasting improvement in functional activities by wearing the hemispatial sunglasses. CONCLUSION: Hemispatial sunglasses appear to have a potentially specific effect on visual neglect in certain patients with right hemispheric lesions. Further investigation is necessary to determine the nature of this effect and its scope of applicability.

Adult↗
PubMed1996

Cloning and characterization of the Pichia pastoris PRC1 gene encoding carboxypeptidase Y.

We purified a 58 kDa serine protease from culture-supernatant of Pichia pastoris and found that the NH2-terminal amino acid sequence of this protease is closely homologous to that of mature protein of Saccharomyces cerevisiae carboxypeptidase Y (CPY), which is encoded by the PRC1 gene. Using the S. cerevisiae PRC1 gene as a hybridization probe, a cross-hybridizing fragment of P. pastoris genomic DNA was identified and the gene, PRC1, encoding CPY, was cloned. The open reading frame of the P. pastoris PRC1 gene consists of 1569 bp encoding a protein of 523 amino acids. The molecular mass of the protein is calculated to be 59.44 kDa without sugar chains. The protein comprises 20 amino acids of pre (signal)-peptide, 87 amino acids of pro-peptide and 416 amino acids of mature peptide, and has four N-glycosylation sites. The NH2-terminal amino acid sequence of mature peptide is completely identical with that of the protease purified from the culture-supernatant. There is 61% identity between the amino acid sequences of P. pastoris Prc1p and S. cerevisiae Prc1p. Chromosomal disruption of the PRC1 gene resulted in the loss of CPY activity. Over-expression of the PRC1 gene under regulation of the P. pastoris AOX1 promoter resulted in accumulation of a large amount of active CPY in the intracellular fraction, and secretion of a slightly larger molecule that is thought to be pro-CPY. The nucleotide sequence data reported in this paper will appear in the EMBL Nucleotide Sequence Databases under the Accession Number X87987.

Amino Acid Sequence↗
PubMed1996

Elevation of plasma thrombomodulin level in primary glomerulonephritis with heavy proteinuria.

Thrombomodulin (TM) is a thrombin receptor found on endothelial cells. TM acts as a cofactor for the thrombin-catabolized activation of protein C and protects these cells from the formation of thrombi. We hypothesized that the soluble form of TM which reflects the damage of the endothelial cells and that simultaneously, soluble TM will be affected by renal excretion because a significant positive correlation has been found between soluble TM and serum creatinine (sCr) in the renal failure state. However, there have been no reports on the relationship between plasma TM and clinical parameters except for sCr in primary glomerulonephritis (PGN). Plasma TM (pTM) and urinary TM (uTM) were measured in 107 patients with PGN using a one-step sandwich enzyme immunoassay. These values were assessed together with other laboratory and histological findings. We were able to divide all subjects into two groups: an sCr-dependent group whose sCr level was over 1.2 mg/dl and an sCr-independent group whose sCr level was under 1.2 mg/dl. In the sCr-independent group, patients who suffered from nephrotic syndrome (NS) had a much higher pTM level than patients who did not suffer from NS. Histological findings and other parameters were not correlated with pTM or uTM. Therefore, the two patients who suffered from NS with very high pTM levels and normal sCr level at the time of admission exhibited a decrease in their pTM value as their condition improved. We concluded that in our patients, pTM was affected not only by renal excretion of TM, but also by renal damage with heavy proteinuria and may have been associated with an ongoing disease process in PGN.

Adolescent↗
PubMed1995

Urokinase-type plasminogen activator (uPA) and its receptor (CD87): a new target in tumor invasion and metastasis.

Extravasation and intravasation of tumor cells in solid malignant tumors is controlled by 3 steps: 1) attachment to and interaction of tumor cells with components of the basement membrane and the extracellular matrix, 2) local proteolysis, and 3) tumor cell migration. Evidence has accumulated that different types of tumor-associated proteases, their inhibitors and receptors are involved in tumor invasion and metastasis. Four different classes of proteases are known to be correlated with the malignant phenotype: 1) Matrix metalloproteases; including collagenases, gelatinases and stromelysins. 2) Cysteine proteases; including cathepsins B and L. 3) Aspartyl protease cathepsin D. 4) Serine proteases; including plasmin and tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). A strong independent prognostic value (relapse-free and/or overall survival) has especially been demonstrated for uPA and its inhibitor PAI-1 in patients with cancer of the breast, ovary, stomach, esophagus, colon, lung, and kidney thus predicting the course of the cancer disease. The strong correlation between elevated uPA and/or PAI-1 values in primary cancer tissues and the malignant phenotype of cancer cells has prompted to explore new tumor biology-oriented concepts in order to suppress uPA or uPA receptor (CD87) expression or to abrogate interaction of uPA with CD87. Various very different approaches to interfere with the expression or reactivity of uPA or CD87 at the gene or protein level were successfully tested including antisense oligonucleotides, antibodies, inhibitors and recombinant or synthetic uPA and CD87 analogues.

Neoplasm Invasiveness↗
PubMed1995

Clinical effect of the anti-platelet drug, dilazep dihydrochloride, in patients at the microalbuminuric stage of diabetic nephropathy--a multi-center study.

Clinical effects of an anti-platelet drug (dilazep dihydrochloride) in the microalbuminuric stage of diabetic nephropathy were investigated in a multi-center study. Thirty-seven patients with at the microalbuminuric stage of diabetic nephropathy were examined in the present study. They were administered 300 mg/day of dilazep dihydrochloride (Comelian-Kowa) orally for 6 months. Mean values of albuminuria after the administration of dilazep dihydrochloride were significantly decreased compared with the pre-administration values. Urinary NAG activity was improved after this treatment in the microalbuminuric stage of diabetic nephropathy. Furthermore, impairment of renal function was not observed at that stage. It appears that administration of dilazep dihydrochloride from the early stage of diabetic nephropathy may be useful for the improvement of albuminuria and prevention of renal dysfunction.

Adult↗
PubMed1994

Glucocorticoid induction of rat angiotensin II type 1A receptor gene promoter.

Promoter/luciferase reporter analysis indicated that the 5'-flanking region of rat angiotensin II type 1A receptor gene was functional, both in the rat aortic smooth muscle cells (RASMCs) and in Y1 cells derived from mouse adrenal cortex. In response to dexamethasone (Dex), transcriptional activity of promoter increased in transfected RASMCs, suggesting the functional cis-action of a glucocorticoid responsive elements (GRE). Furthermore, the expression of the rat AT1A gene was also up-regulated by Dex at the levels of both mRNA and protein in RASMCs.

Adrenal Cortex Neoplasms↗
PubMed1994

The positive and negative cis-acting elements for methanol regulation in the Pichia pastoris AOX2 gene.

The methylotrophic yeast Pichia pastoris has two alcohol oxidase genes, AOX1 and AOX2. The AOX2 gene is transcribed at a much lower level than the AOX1 gene. Apart from this difference in expression levels, the two genes are regulated similarly. To study the role of cis-acting elements in the promoter region of the AOX2 gene, we constructed expression plasmids in which the human serum albumin (HSA) gene was placed under the control of various deleted or mutated AOX2 promoter derivatives. By analyzing the expression of HSA in P. pastoris transformants, we have identified three cis-acting regulatory elements in the AOX2 promoter. The positive cis-acting element AOX2-UAS, located between positions -337 and -313 (relative to the transcription initiation codon), is required for response to transcriptional induction by methanol in an orientation-independent manner, and artificial amplification of the AOX2-UAS resulted in an increase in the transcriptional activity of the promoter. A sequence homologous to AOX2-UAS was also found in the AOX1 promoter, and in methanol-regulated promoters in other methylotrophic yeast. Two negative cis-acting elements, AOX2-URS1 and AOX2-URS2 play a role in repressing transcription from the AOX2 promoter. The function of AOX2-UAS is completely repressed by this unique repression system when both the AOX2-URS1 and AOX2-URS2 are functional.

Alcohol Oxidoreductases↗
PubMed1994

Effects of urinary trypsin inhibitor on the invasion of reconstituted basement membranes by ovarian cancer cells.

Using the human ovarian cancer cell line HOC-1, we investigated the effects of urinary trypsin inhibitor (UTI) purified from human urine and its related synthetic peptides on the invasive potential of cancer cells in an in vitro assay. Invasiveness of tumor cells was determined using a modified Boyden chamber and a reconstituted basement membrane Matrigel. Three peptides (peptide 1, peptide 2, and peptide 3), representing sequences within UTI, were synthesized. HOC-1 cells showed detectable and reproducible levels of expression of surface urokinase-type plasminogen activator (uPA) and plasminogen/plasmin by cell ELISAs and enzyme assays. UTI was found to strongly inhibit plasmin and human leukocyte elastase (HLE). Peptide 2 and peptide 3 specifically inhibit HLE and plasmin activity respectively. Peptide 1 has essentially no inhibitory activity. Treatment with UTI and peptide 3 reduces the incidence of invasion, whereas peptide 1 and peptide 2 do not affect invasion. The inhibitory effect on cell invasion is dose-dependent. The proteolytic enzyme plasmin may be involved in human ovarian cancer invasion in extracellular matrix degradation, and the use of UTI and peptide 3 that inhibits plasmin specifically reduces invasion by tumor cells.

Amino Acid Sequence↗
PubMed1994

Analysis of monoclonal antibodies reactive with meconium- and amniotic fluid-derived mucin.

The present study was undertaken to determine whether monoclonal antibodies (moABs TKH-2, MA54, MA61, B72.3, and CC49) directed toward O-linked mucin-type glycoprotein detect the NeuAc alpha 2-6GalNAc (sialyl Tn) epitope in meconium- and amniotic fluid-derived mucin. Fetal colonic mucosal cells express the sialyl Tn antigen, particularly in goblet cell mucin. The reactivities of these moABs with a perchloric acid extract of meconium (meconium extract) and different native and neuraminidase treated glycoproteins were examined by solid-phase enzyme-linked immunosorbent assay (ELISA). All the moABs react with the meconium supernatant and meconium extract. The reactivities of TKH-2, MA54, and MA61 are neuraminidase sensitive, and the reactivity of TKH-2 with meconium extract was specifically inhibited by ovine submaxillary mucin (OSM). A NeuAc alpha 2-6GalNAc epitope is the characteristic component in meconium. Mucin released from the fetal respiratory tract could, in part, provide an alternative source in the amniotic fluid. TKH-2 is the most sensitive antibody directed to sialyl Tn antigen in meconium supernatant. The likelihood of TKH-2 serving as the basis for a sensitive assay to detect sialyl Tn in meconium- and amniotic fluid-derived mucin is provided.

Amniotic Fluid↗
PubMed1994

Urinary trypsin inhibitor (UTI) and fragments derived from UTI by limited proteolysis efficiently inhibit tumor cell invasion.

We investigated the effects of purified human urinary trypsin inhibitor (UTI) and fragments derived from UTI by proteolysis on the invasive potential of ovarian cancer cells (HOC-I) and gestational choriocarcinoma cells (SMT-ccl) using an in vitro reconstituted basement membrane invasion assay. These cells express cell-associated plasmin and functional uPA receptors that are partially occupied by ligands. SMT-ccl cells, which express threefold higher levels of cell-associated plasmin activity than HOC-I cells, showed approximately twofold increase in their invasive potential. For the invasion assay, HOC-I cells were primed with exogenous plasminogen, but SMT-ccl cells were not. Human leukocyte elastase (HLE)-digested UTI (22 kDa fragment; UTI-22) inhibited plasmin practically with the same strength as native UTI. Trypsin-digested UTI (20 kDa fragment; UTI-20), however, did not inhibit plasmin significantly. Treatment of cells with UTI or UTI-22 reduced the incidence of tumor cell invasive capacity, whereas the inhibitory effect of UTI-20 was not remarkable. The inhibitory effect on tumor cell invasion was dose-dependent and non-toxic; moreover, it was not mediated by inhibition of the tumor cell chemotactic response or of cell attachment to matrigel. These results indicate that inhibition of the proteolytic enzyme plasmin specifically reduced the invasive capacity of tumor cells in vitro.

Amino Acid Sequence↗
PubMed1994

Plain radiological findings in Ménière's disease.

In order to investigate the characteristics of plain radiography of Ménière's disease, the degree of the pneumatization and the distance between the sigmoid plate and the bony wall of the vestibule in Schüller's view were examined in patients with unilateral and bilateral Ménière's disease, non-Ménière vertiginous disease and healthy subjects. There was no difference of the degree of pneumatization and the distance among the patients with Ménière's disease, the non-Ménière inner ear disease group and in healthy subjects. The distance of the unaffected ear was significantly shorter in patients showing a shorter distance of the affected ear. There was no relationship between the distance and age of onset of the disease, and duration of the disease. Therefore, it is concluded that the dysfunction of endolymphatic sac does not always reflect poor mastoid pneumatization and/or shorter distance in the plain radiography and that other etiological mechanisms such as autoimmune disease should be considered in some patients having evidence of endolymphatic hydrops.

Age of Onset↗
PubMed1994

Occurrence of C3 nephritic factor and C4 nephritic factor in membranoproliferative glomerulonephritis (MPGN).

One hundred patients diagnosed with hypocomplementaemic MPGN (C3 < 40%) were studied to determine the presence of C3 nephritic factor (C3NeF) and/or C4 nephritic factor (C4NeF). Of those studied, 12 were C3NeF-positive, nine were C4NeF-positive and 10 were positive for both C3NeF and C4NeF. In the 10 patients both C3NeF- and C4NeF-positive, a marked decrease in C3 and C5 levels and a decrease in levels of late components from C6 to C9 were observed. This observation was in contrast to that seen in patients who were either C3NeF- or C4NeF-positive. Patients positive for both C3NeF and C4NeF continued to exhibit hypocomplementaemia after therapy. Immunofluorescent findings revealed heavy C3 immunoglobulin deposits in the 10 patients who were both C3NeF- and C4NeF-positive, whereas no such deposits were found in those patients who were either C3NeF- or C4NeF-positive only. When those patients who were both C3NeF- and C4NeF-positive were compared with those who were either C3NeF- or C4NeF-positive, nephritic syndrome and a poor prognosis were observed more frequently. This study demonstrates a correlation between clinical outcome and hypocomplementaemic MPGN. Further investigations of MPGN as an autoimmune disease are necessary.

Adolescent↗
PubMed1994

Intra-His bundle block corresponds with interruption of the branching portion of the His bundle.

We compared His-bundle electrograms with pathological findings of the atrioventricular conduction system in four patients with complete atrioventricular intra-His block with narrow QRS complexes on ECG. Split His electrograms were recorded at the time of electrophysiological study. The patients died from noncardiac causes at 10 days, 1 year, 4 years, and 9 years, respectively, after the pacemaker implantation. Serial sections through the atrioventricular conduction system revealed strictly localized more than 50% reduction of conducting cells replaced by fibrosis at the branching portion of His bundle. The proximal portions of the bundle branches also exhibited decrease of the conducting cells showing a rough positive relation with the patient's age. Therefore, we considered that the H1 spikes seen on His-bundle electrograms originated from the penetrating portion of His, which was virtually intact in our cases, and that the H2 spikes originated from the right side of the distal branching portion of His.

Aged↗