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Biomedical subjects

H Ohi

Publications and source records attributed to H Ohi.

At least 55 records · Page 3Linked to original sources
PubMed1998

A bifunctional hybrid molecule of the amino-terminal fragment of urokinase and domain II of bikunin efficiently inhibits tumor cell invasion and metastasis.

Urinary trypsin inhibitor (UTI) inhibits efficiently tumor cell invasion and the formation of metastasis. The anti-metastatic effect is dependent on the COOH-terminal domain II of UTI [UTI-(78-136)-peptide]. To develop a molecule that binds with high affinity to the urokinase (uPA) receptor (uPAR) on tumor cell surfaces, a bifunctional hybrid molecule [uPA-(1-134)-UTI-(78-136)] consisting of the uPAR-binding NH2-terminal fragment [UTI-(78-136)-peptide] of uPA at the NH2-terminus of UTI-(78-136)-peptide was produced in Escherichia coli by genetic engineering. The purified hybrid protein inhibited trypsin and plasmin 2-3-fold less effectively than UTI-(78-136)-peptide and was found to bind to human tumor cells via uPAR, which was confirmed by cell binding and competition experiments. Using a modified Boyden chamber and an artificial basement membrane, Matrigel, it was found that the hybrid protein is very effective at inhibiting invasion by uPAR-expressing human tumor cells. Sensitivities of tumor cells towards the anti-invasive effect of uPA-(1-134)-UTI-(78-136) correlated with the density of uPAR on human tumor cells. Furthermore, in the spontaneous metastasis model, the hybrid protein inhibited the formation of lung and/or lymphatic metastasis by human ovarian carcinoma and choriocarcinoma cells. The hybrid protein was much more effective than uPA-(1-134)-peptide, UTI-(78-136)-peptide, or UTI. We conclude that this approach extends the possibility of applying recombinant protein for therapeutic use in inhibition of human tumor cell metastasis.

Amino Acid Sequence↗
PubMed1998

Chromosomal DNA patterns and gene stability of Pichia pastoris.

We have clearly resolved four chromosomal bands from four Pichia pastoris (Komagataella pastoris) strains by using contour-clamped homogeneous electric field gel electrophoresis. The size of the P. pastoris chromosomal bands ranged from 1.7 Mb to 3.5 Mb and total genome size was estimated to be 9.5 Mb to 9.8 Mb; however, chromosome-length polymorphisms existed among four strains. Thirteen cloned genes isolated from strain GTS115 were assigned to the separated chromosomes, revealing that different hybridization patterns were observed in the AOX2 and URA3 genes among strains. P. pastoris is frequently used as an efficient host for heterologous gene expressions. We analysed chromosomal stability of strain GTS115-derived recombinant cell expressing human serum albumin during serial cultivation under the condition of vegetative and non-selective growth. No chromosomal rearrangements were observed and the expression constructs integrated into the his4 locus on chromosome I were very stable even at 83 generations, suggesting that stable expression would be carried out even in large-scale fermentation.

Chromosomes, Fungal↗
PubMed1998

Cloning and expression analysis of a cDNA coding for a dexamethasone-inducible cytochrome P450 in Xenopus laevis liver.

We previously purified a cytochrome P450 (P450) from liver microsomes of adult female Xenopus laevis. In this study, we screened a cDNA library of Xenopus liver to isolate the cDNA clone coding for this P450. The 5'-end of the resultant cDNA was truncated at the N-terminal region and extended by method of rapid amplification of cDNA end to give the complete coding sequence. Amino acid sequence showed this clone to be 36% to 55% identical to members of the CYP2 family and less than 31% identical to members of other gene families, and to belong to the CYP2Q subfamily. This gene is expressed constitutively in the livers of adult male and female frogs, and is significantly induced by dexamethasone administration.

Amino Acid Sequence↗
PubMed1998

Glomerular deposition of mannose-binding lectin (MBL) indicates a novel mechanism of complement activation in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgA-N) is considered the most common glomerular disease in the world and leads to renal failure in a substantial number of patients. Although many studies have looked at the pathogenesis of the disease, many points need to be clarified, including the mechanism of complement activation. Recent studies have shown that mannose-binding lectin (MBL or mannose binding protein, MBP) initiates activation of the complement cascade (lectin pathway) utilizing two types of MBP-associated serine protease, namely MASP-1 and MASP-2. The present study was undertaken to elucidate whether the lectin pathway was involved in the pathogenic mechanism of IgA-N. METHODS: Forty-five renal biopsy cases with IgA-N, 35 cases with other forms of glomerulonephritis (GN), and normal kidney tissues were collected and an immunohistochemical study was performed using monoclonal antibodies against MBL and MASP-1. Furthermore, clinicopathological and serological features were also analysed in the patients with IgA-N. RESULTS: Glomerular deposition of MBL, which was accompanied by MASP-1, was detected in 11 of 45 (24.4%) cases with IgA-N, while it was detected in only one case with other forms of GN. The deposited MBL/MASP-1 was observed to associate with C3b/C3c and C5b-9 but not with IgG, IgM, C1q, C4c, or properdin. Compared with MBL/MASP-1 negative cases with IgA-N, the positive cases with IgA-N were young and the renal biopsies had been performed at an early stage of the disease. No significant correlation was found between glomerular deposition of MBL/MASP-1 and proteinuria, haematuria, creatinine clearance, and serum levels of IgA, C3, or C4 at the time of renal biopsy. There were also no significant differences between MBL/MASP-1 positive cases and negative cases in the plasma levels of circulating immune complexes or soluble C5b-9. CONCLUSION: The lectin pathway of complement activation, which is initiated by the MBL/MASPs complex, evidently contributes to the development of glomerular injury in a significant number of cases with IgA-N. In addition, these findings will add insight to the pathogenesis of IgA-N, including its relation to infection, since MBL plays a crucial role in the host defense against various pathogens.

Adolescent↗
PubMed1998

Appearance of nephrotic syndrome following interferon-alpha therapy in a patient with hepatitis B virus and hepatitis C virus coinfection.

A 59-year-old woman with hepatitis B surface antigen (HBsAg) and hepatitis C viral (HCV) antibody presented with proteinuria and hematuria. The patient was treated with interferon-alpha (INF-alpha) because plasma aminotransferase levels had been elevated and a liver biopsy had showed chronic active hepatitis. Her urinary protein excretion decreased as liver function normalized and her serum HCV-RNA was negative during treatment. Eleven weeks after completion of INF-alpha treatment, she suddenly presented with nephrotic-range proteinuria, although an improvement in the hepatic function was maintained. Renal pathologic findings were consistent with membranous glomerulonephritis (MGN), and HBsAg was detected in the glomeruli but not HCV. After treatment with prednisolone, her 24-hour protein excretion was below 0.7 g/day. To our knowledge this is the first report on hepatitis B virus MGN with nephrotic syndrome following IFN-alpha therapy for HCV. This suggests that treatment with INF-alpha might affect the immune processes and may be associated with the pathogenic mechanism in this patient.

Anti-Inflammatory Agents↗
PubMed1998

Interleukin 12 upregulates the release of vascular permeability factor by peripheral blood mononuclear cells from patients with lipoid nephrosis.

The vascular permeability factor (VPF) is a lymphokine that has been shown to play a role in lipoid nephrosis (LN). Prior studies have shown that interleukin (IL) 12 promotes T helper type 1 differentiation and enhances production of T helper type 1 cytokines such as gamma interferon and IL-2. We, therefore, investigated the effects of recombinant human IL-12 on the release of VPF by peripheral blood mononuclear cells (PBMC) from LN patients. The VPF activity was measured according to the method of Ovary, with minor modifications. The goal of the present study was to examine the importance of IL-12 in concanavalin A induced VPF release in vitro. The levels of VPF were measured in a group of healthy subjects, LN patients with or without the nephrotic syndrome, and patients suffering from IgA nephropathy. There was a significantly increased concanavalin A induced release of VPF in LN and IgA nephropathy patients with nephrotic syndrome as compared with normal controls. Recombinant human IL-12 was found to enhance VPF release in a dose-dependent manner. Neutralization of endogenously produced IL-12 by anti-IL-12 antibody resulted in a decreased release of VPF by LN PBMC. These data indicate that endogenously produced IL-12 functions as a costimulatory molecule in vitro. Our data show that IL-12 can upregulate the release of VPF derived from LN PBMC. Thus IL-12 might be a potent adjuvant for inducing VPF. Therefore, IL-12 antagonists may interfere with newly initiated and ongoing VPF release associated with nephrotic syndrome.

Adolescent↗
PubMed1998

[Results of clinical study with epirubicin hydrochloride injectable solution in hepatoma].

A 10-center cooperative clinical study with a new formulation of epirubicin hydrochloride injectable solution (Epirubicin-RTU) was conducted in patients with hepatocellular carcinoma. Epirubicin-RTU 60 mg/m2 was injected into the hepatic artery and a three-week drug-free interval followed. Of 15 patients with hepatocellular carcinoma registered in this study, 14 patients were eligible, and they all completed the entire course. The objective was to investigate the safety of treatment with Epirubicin-RTU in 14 eligible patients. The adverse drug reactions frequently observed in these 14 eligible cases were leukopenia, neutropenia, thrombocytopenia, alopecia, and fever. They were all reversible and tolerable. With these results. Epirubicin-RTU was considered to be a safe pharmaceutical product to inject into the hepatic artery.

Adult↗
PubMed1998

[Beneficial effect of salazosulfapyridine (SASP) in a patient with secondary renal amyloidosis].

A 55-year old female with rheumatoid arthritis (RA) had presented with proteinuria since July 1996. She was referred to us for persistent edema on her face and legs in November 1996. On admission, her 24-hour urinary protein excretion was 4.4 g/day, total serum protein level was 5.3 g/dl, and serum level of amyloid A protein (SAA) was elevated to 45.8 mg/ml. A percutaneous renal biopsy was performed, and light microscopy revealed varying degrees of amyloid deposits in the mesangial areas and arteriolar walls. The diagnosis of secondary amyloidosis (AA amyloidosis) was based on immunohistochemical staining for amyloid A protein using monoclonal antibody against SAA. Four weeks after treatment with salazosulfapyridine (SASP) and dipyridamole, proteinuria began to decrease and the edema had disappeared. Finally she recovered from nephrotic syndrome. AA amyloidosis has been thought to have a poor prognosis, with progression to renal failure. Since there is no specific effective therapy for the disease, it is very important to reduce the activity of the underlying cause. In our patient with renal amyloidosis following RA, SASP was evidently effective for arthritis and improvement of renal function. SASP might have a beneficial effect on AA amyloidosis by suppressing inflammatory cytokines.

Amyloidosis↗
PubMed1998

Level of red blood cells in the urinary sediment reflects the degree of renal activity in Wegener's granulomatosis.

Symptoms due to renal lesions often disappear and smolder by successful treatment during the first episode of Wegener's granulomatosis (WG). It is indispensable to recognize an increase in disease activity and provide adequate treatment to inhibit the progression of renal dysfunction as well as regulate disease activity in patients with WG. We gave attention to red blood cells in urinary sediment (U-RBC), a criterion in the diagnosis of WG, to more exactly determine the degree of renal activity. Comparison of level of U-RBC with other laboratory data and renal histology was performed in the clinical course of six cases. The level of U-RBC altered reversibly during the period studied and correlated with the C-reactive protein level and erythrocyte sedimentation rate which reflect disease activity in cases with microhematuria before treatment. When U-RBC disappeared within eight weeks after treatment, glomerular histological change remained small. The reported cases revealed that the alteration in U-RBC was more sensitive and more specific for renal involvement than the other disease markers. In conclusion, the level of U-RBC reflects the degree of renal activity in WG. We propose that the quantitation of U-RBC is extremely useful in following patients with WG.

Adult↗
PubMed1997

Purification and characterization of a cytochrome P450 from liver microsomes of Xenopus laevis.

A new cytochrome P450 (P450) has been purified to near homogeneity from Xenopus laevis liver microsomes. Two steps of column chromatographies (n-octylamino Sepharose 4B and Mono Q) and fast protein liquid chromatofocusing were performed consecutively, and the final preparation containing 19 nmol P450/mg protein gave a single band of 52 kDa on SDS-PAGE at an isoelectric point of 6.7. This enzyme had a common feature of microsomal P450s in NH2-terminal region, and some of the internal sequences were similar to the corresponding sequences of reported P450s. The purified Xenopus P450 cross-reacted with antibodies against CYP2B1, rat CYP2E1, and CYP2C13, but not with rat CYP1A1, CYP3A2, or CYP4A1. Upon reconstitution with rat NADPH-cytochrome P450 reductase and phospholipid, the Xenopus P450 catalyzed aniline hydroxylation and N-nitrosodimethylamine N-demethylation. Cytochrome b5 enhanced these reactions. This P450 did not catalyze the hydroxylation of either hexobarbital or testosterone. Thus, the catalytic activities of this P450 were comparable with those of mammalian CYP2E1. Expression of this P450 was observed in liver, kidney, lung, and testis, and the level was highest in kidney. Tissue specificity of expression was the same in both male and female frogs.

Amino Acid Sequence↗
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↗
PubMed1997

Interleukin 10 and interleukin 13 synergize to inhibit vascular permeability factor release by peripheral blood mononuclear cells from patients with lipoid nephrosis.

It has been proposed that a vascular permeability factor (VPF) is involved in the pathogenesis of lipoid nephrosis (LN). There is now increasing evidence that interleukin 10 (IL-10) and interleukin 13 (IL-13) have regulatory effects on cytokine production by activated macrophages. These results prompted us to study the effects of recombinant human IL-10 and IL-13 on VPF secretion in LN. In the present study, we demonstrate that the regulatory cytokines IL-10 and IL-13 are potent inhibitors of the VPF activity of activated peripheral blood mononuclear cells. Each cytokine was found to suppress VPF secretion in a dose-dependent fashion. More importantly, the combination of the cytokines was found to give a potent synergistic suppression of VPF by concanavalin A activated peripheral blood mononuclear cells from patients with LN. When both anti-IL-10 and anti-IL-13 antibodies were added together to the peripheral blood mononuclear cells, a further increase of concanavalin A enhanced secretion of VPF occurred. These data establish IL-10 and IL-13 as potent inhibitors of VPF activity and suggest their utility in controlling deleterious VPF-mediated responses such as occur in LN patients with nephrotic syndrome.

Adolescent↗