Biomedical subjects

H Okuda

Publications and source records attributed to H Okuda.

At least 127 records · Page 7Linked to original sources

PubMed1998

Expression analysis of human Rhesus blood group antigens by gene transduction into erythroid and non-erythroid cells.

Rh blood group antigens are associated with non-glycosylated human erythrocyte membrane proteins encoded by two closely related genes, RHCE and RHD, and with a glycoprotein, a critical co-expressing factor encoded by the RH50 gene. The sequence analysis of RHCE transcripts has revealed that RhE/e and C/c serological phenotypes are associated with a nucleotide substitution in exon 5 and six substitutions in exons 1 and 2 of RHCE gene, respectively. Smythe et al. have shown that the full length transcript of RhcE gene expressed c and E antigens and the transcript of RhD gene expressed D and G antigens, using retroviral-mediated gene transduction into K562 cells. We performed an epitope analysis of Rh antigen by constructing retroviral gene coding six RH cDNAs, which contain RhcE, ce, CE and D cDNAs, and CE-D, D-CE chimera cDNAs. The cDNAs were introduced into KU812E cells and the expressed antigens were analyzed by flow cytometry. These studies revealed that the C/c and E/e associated substitutions actually participated in respective polymorphic epitopes. However, the C antigen was not detected on the KU812E cells introduced with CE cDNA, despite E antigen being expressed. The study with the chimera gene between CE and D cDNAs also indicated that the Rh epitopes were not constructed with short polymorphic exofacial peptide loops only but also with other peptide fragments and membrane components. Co-expression studies of Rh50 and RhD or cE gene in non-erythroid cells, 293, and expression studies of Rh50 in another erythroid cell, HEL, did not show any Rh antigens on the transduced cells, despite the Northern blot study showing both transcripts in the cells. It was suggested that at least a second co-expressing factor was needed to express RhCE or D antigens on the plasma membrane.

Cell Line↗

PubMed1998

Norepinephrine-augmenting lipolytic effectors from Astilbe thunbergii rhizomes.

An EtOAc-soluble fraction from a 80% Me2CO extract of the rhizomes of Astilbe thunbergii enhanced norepinephrine-induced lipolysis in rat fat cells, while an EtOAc-insoluble fraction had no effect. The active substances isolated from the EtOAc-soluble fraction of the rhizomes were identified as eucryphin (1), bergenin (2), and astilbin (3), which enhanced norepinephrine-induced lipolysis at concentrations of 10-1000 microgram/mL, while they themselves did not cause lipolysis. Furthermore, these compounds slightly stimulated adrenocorticotrophic hormone-induced lipolysis and inhibited insulin-induced lipogenesis from glucose.

Adipocytes↗

PubMed1998

Prolonged cell survival enhances peritoneal dissemination of gastric cancer cells.

Bcl-2 and a Bcl-2-binding protein BAG-1 function in protection from apoptosis induced by a variety of stimuli. Deregulated expression of Bcl-2 leads to inhibition of apoptosis and is correlated with development of various cancers. Here, we provide evidence that prolonged cell survival introduced by overproduction of Bcl-2 or BAG-1 strongly enhances peritoneal dissemination of human gastric cancer MKN74 cells. Gene transfer-mediated overexpression of Bcl-2 or BAG-1 led to prolonged cell survival of MKN74 cells against serum-starved apoptosis and anoikis. When the viable transfectants were inoculated into the intraperitoneal cavity of BALB/c nude mice, the Bcl-2-expressing MKN74 cells and the BAG-1-expressing MKN74 cells exhibited strongly enhanced peritoneal dissemination in BALB/c nude mice and whole disseminated tumor weights were increased by 4-fold and 3.3-fold, respectively, compared with the control transfectants. The enhanced peritoneal dissemination of MKN74-Bcl-2 and MKN74-BAG-1 transfectants correlated well with resistance to cell death induced by serum-starvation and anoikis. However, the overexpression of Bcl-2 or BAG-1 caused no significant difference among the transfectants in cell growth rates, either in vitro or in vivo. Taken together, these studies demonstrate that resistance to apoptosis is a crucial factor for development of peritoneal dissemination of human gastric cancer cells.

Adenocarcinoma↗

PubMed1998

A splicing mutation of the RHAG gene associated with the Rhnull phenotype.

Rhnull is a syndrome serologically characterized by the deficiency of all Rh antigens on human red blood cells. Rhnull is divided into two types: regulator and amorph. Recently, Cherif-Zahar et al. proposed that the RHAG gene encoding the Rh50 glycoprotein is a candidate for inducing regulator type Rhnull. We investigated both the RH and RHAG genes in an Rhnull individual. The reticulocytes from the propositus had RHD, RHcE, and RHCe transcripts without any mutation. However, the sequence analysis of RHAG cDNA showed a deletion of 122 bp from nucleotide 946 to 1067. This deletion was revealed to be due to a homozygous splicing mutation, which is a single base substitution at the consensus sequence of the splicing acceptor site (AG-->AT). The mutation appeared to break the 'GT-AG' splicing rule and to cause 122 bp exon skipping accompanied by a frameshift. This study confirms that the RHAG gene is the most likely candidate for the 'regulator' gene of Rhnull cases.

Adolescent↗

PubMed1998

Isolation of lipolytic substances caffeine and 1,7-dimethylxanthine from the stem and rhizome of Sinomenium actum.

We attempted to isolate lipolytic substances from the stem and rhizome of Sinomenium actum Rehder et Wilson by using high-performance liquid chromatography (HPLC). S-I and S-II were isolated from the fractions showing lipolytic activity. S-I and S-II were identified as caffeine and 1,7-dimethylxanthine, respectively, by direct comparison with authentic samples. Caffeine (S-I) dose-dependently stimulated lipolytic activity in isolated fat cells of rats, at concentrations of 500 to 1000 microM. 1,7-Dimethylxanthine (S-II) also stimulated lipolytic activity at concentrations of 500 to 1000 microM. Furthermore, we found that caffeine and 1,7-dimethylxanthine enhanced catecholamine-induced lipolysis at lower concentrations of 0.1 to 1 microM.

Animals↗

PubMed1998

Suppressive effect of globin digest on postprandial hyperlipidemia in male volunteers.

We have reported previously that various edible protein digests inhibit dietary hyperlipidemia in mice, rats, pigs and dogs. Of the various digests tested, globin digest had the most potent inhibitory activity, and a tetrapeptide extracted from globin digest, Val-Val-Tyr-Pro, had activity 7000-fold greater than that of the parent digest. In this clinical study, we investigated the influence of globin digest on serum chylomicron triglyceride concentrations as an indicator of the effect of globin digest on fat absorption and catabolism in humans. Parallel and crossover trials were conducted in which men consumed a control high fat diet (25 g fat, 7.6 g carbohydrate, 1.9 g protein and 0.7 g sodium chloride) or the same diet supplemented with globin digest. The supplemented dosages were 1 and 4 g globin digest. In the parallel trial, 22 men were divided into three groups: control, globin digest 1 g and globin digest 4 g. The increases in chylomicron triglyceride concentrations at 1 h after ingestion of 1 or 4 g globin digest were significantly lower (P < 0.05) compared with the control group. The crossover trial involved six subjects who consumed the control high fat diet and the same diet supplemented with 4 g globin digest. Serum chylomicron triglyceride levels increased in both groups at 1 and 2 h after ingestion, but when subjects consumed 4 g globin digest the increases were suppressed to 75 (P < 0.05) and 42% (P < 0.05) of the increases in controls at the corresponding times, respectively. The areas under the curves of chylomicron and serum total triglyceride concentrations during the 4 h after ingestion of 4 g globin digest were 46 (P < 0.05) and 34% (P < 0.05) lower, respectively, than when the men consumed the high fat control diet. In these trials, globin digest reduced the increase in serum chylomicron triglyceride concentrations as a result of the ingestion of a high fat diet. This hypotriglyceridemic effect of globin digest may be valuable for preventing obesity and in lowering the incidence of cardiovascular diseases.

Adult↗

PubMed1998

Detection and quantification of soluble intercellular adhesion molecule-1 (sICAM-1) in the serum and urine of patients with bladder cancer.

BACKGROUND: A possible role for intercellular adhesion molecules in tumor progression and metastasis has been strongly suggested. To investigate the effect of soluble intercellular adhesion molecule-1 (sICAM-1) on bladder cancer, sICAM-1 serum and urinary concentrations were measured in patients with superficial or invasive bladder cancer and in patients with prostatic hypertrophy. METHODS: Serum and urine samples were obtained from 26 patients with transitional cell carcinoma of the bladder (mean age, 66.8 years) and 14 patients with benign prostatic hypertrophy (BPH; mean age, 70.5 years). Fifteen healthy volunteers served as control patients. Samples were collected before surgery and 5 days after surgery. The serum and urinary slCAM-1 levels were measured by an ELISA. RESULTS: The preoperative serum concentration of sICAM-1 was significantly higher in patients with invasive bladder cancer (351.8+/-158.0 ng/mL) than in the healthy controls (233.1+/-96.1 ng/mL; P< 0.05) or BPH patients (224.7+/-80.5 ng/mL; P< 0.05). In addition, serum sICAM-1 levels were significantly higher in patients with tumors greater than 3 cm in size (412.7+/-147.6 ng/mL) than in patients with smaller tumors (246.6+/-101.2 ng/mL; P<0.05). Urinary sICAM-1 levels in patients with invasive bladder cancer were also significantly higher than in the patients with superficial cancer prior to surgery. CONCLUSION: Our results suggested that sICAM-1 may play an important role in the progression of bladder cancer, and that elevated serum sICAM-1 levels may be related to tumor size.

Adolescent↗

PubMed1998

[A case of Sjögren's syndrome associated with inflammatory pseudotumor of the liver].

A 71-year-old man had noticed a dry sensation in the mouth with swelling of bilateral parotid glands in 1988. He was given a diagnosis of Sjögren's syndrome (SS) on the basis of characteristic findings of sialography and a minor salivary gland biopsy. He was admitted to our department in Febuary 1995 because of general fatigue of 2 month's duration. Laboratory data showed both positive anti-SSA and anti-SSB antibodies, liver dysfunction, hypoalbuminemia, and thrombocytopenia. Abdominal CT and MRI demonstrated a 2-cm intrahepatic mass (S 6) with enhanced areas at the periphery. The liver biopsy yielded fragments from the intrahepatic mass and hepatic parenchyma. The former was composed of plasma cells, lymphocytes, and histiocytes, compatible with the diagnosis of inflammatory pseudotumor of the liver. The pathological diagnosis of the latter specimen was primary biliary cirrhosis, although antimitochondrial antibody was negative. The intrahepatic mass gradually decreased in size without treatment. Inflammatory pseudotumor is considered to be a benign inflammatory condition simulating a neoplasma and the possibility of an autoimmune reaction is suggested on the basis of etiology. This is the first report of an inflammatory pseudotumor associated with Sjögren's syndrome developing in the liver. The inflammatory pseudotumor should be considered as a possible diagnosis in cases where the tumor is embedded in the liver.

Aged↗

PubMed1998

[A juxtaglomerular cell tumor. Analysis of immunohistochemistry, electron microscopy and in situ hybridization].

We present a case of juxtaglomerular cell tumor measuring 8 mm in diameter in the right kidney. The hypertension was cured and plasma renin activity returned to normal level following tumor resection with partial nephrectomy. We studied histopathologic, electron microscopic, and immunohistochemical findings of the tumor. The majority of tumor cells stores renin granules in cytoplasm. In situ hybridization confirmed us that the most tumor cells produce renin. We use the digoxigenin labeled 0.6-kb length RNA probe of human renal renin, the specificity was analyzed by competition assay (1:50).

Adenocarcinoma↗

PubMed1998

A case of acquired zinc deficiency in a mature breast-fed infant.

We describe a 5-month-old Japanese infant with zinc deficiency, who was exclusively breast-fed and showed improvement after zinc supplement was administered. His serum zinc level and the zinc content of breast milk from his mother were extremely low, although the mother's serum zinc level was within normal limits. Zinc deficiency would not be latently uncommon in a mature breast-fed infant.

Alopecia↗

PubMed1998

[Study on urinary levels of interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha in patients with renal cell carcinoma].

We examined the preoperative and postoperative, urinary levels of the cytokines, interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in 14 patients with renal cell carcinoma (RCC), and 9 patients who underwent nephrectomy as donors (controls). Although urinary IL-1 beta was measurable in every subject, both IL-6 and TNF-alpha were undetectable in 12 of the 14 patients. None of the urinary cytokines showed levels significantly different from the controls preoperatively. Urinary levels of IL-1 beta showed no correlation with clinical stage or histological grade. Only urinary IL-1 beta was significantly elevated after nephrectomy, when compared with the controls (P < 0.05). However, urinary IL-1 beta showed no correlation with operative blood loss or postoperative infection. These findings suggest that measurement of urinary cytokines is not useful for diagnosis or monitoring of therapy in RCC patients.

Adult↗

PubMed1998

[Hereditary macrothrombocytopenia].

A 19 year-old male was referred to our department because of macrothrombocytopenia. His platelet count was 73,000/microliter and giant platelets were observed in the peripheral blood smear specimen. Though he had been suffering from severe atopic dermatitis for four years, he seemed to be healthy without bleeding tendency. When he underwent a shunt operation for tetralogy of Fallot without any complication at nine-years old, thrombocytopenia was allegedly pointed out for the first time. Bone marrow aspiration revealed no abnormal findings with no chromosomal aberration. Normal platelet aggregation responses against adenosine diphosphate, epinephrine, collagen, and ristocetin were observed. The platelet adhesiveness (modified Salzman method) was slightly elevated. Unlike other reported syndromes associated with macrothrombocytopenia, his leukocytes had no inclusion bodies. His mother also had macrothrombocytopenia thus, this disorder was suspected to be hereditary.

Adult↗

PubMed1998

Antilipolytic actions of insulin on basal and hormone-induced lipolysis in rat adipocytes.

The levels of insulin, free fatty acids (FFA), and triglycerides in rat sera increase with age. The increase in serum FFA levels accompanied the stimulation of basal lipolysis (i.e., lipolysis in the absence of lipolytic agents) in fat cells and enlargement of the diameter of the cells. An overnight fast resulted in a significant increase in basal lipolysis in fat cells from 6- and 8-week-old rats. Although insulin inhibited lipolysis induced by norepinephrine and ACTH at a concentration of 10(-10) M, it failed to inhibit basal lipolysis even at a concentration of 10(-6) M. Propranolol, another antilipolytic agent like insulin, also did not affect basal lipolysis. Insulin did not inhibit the accelerated basal lipolysis in enlarged fat cells, fasted fat cells, and sonicated cells. These results indicate that insulin inhibits only the lipolysis induced by lipolytic agents such as norepinephrine and ACTH but not the basal lipolysis found in the absence of lipolytic agents. The possibility that free fatty acids produced by enlarged fat cells initiate insulin resistance and diabetes mellitus, is discussed.

Adipocytes↗

PubMed1998

A possible mechanism of eighteen patient deaths caused by interactions of sorivudine, a new antiviral drug, with oral 5-fluorouracil prodrugs.

A toxicokinetic study was performed using rats to investigate the possible mechanism of 18 acute deaths in Japanese patients with cancer and herpes zoster by interactions of the new oral antiviral drug, sorivudine (SRV), with one of the oral 5-fluorouracil (5-FU) prodrugs within 40 days after approval of the use of SRV. Tegafur, an anticancer 5-FU prodrug suggested to be used by most of the patients who died, and SRV were orally administered to rats simultaneously once daily. All of these rats died within 10 days, whereas rats given SRV or tegafur alone under the same dosage conditions showed no appreciable change over 20 days compared with controls. In the rats given both drugs, bone marrow and intestinal membrane mucosa were greatly damaged at an early stage of the coadministration, and before death, the animals showed marked decreases in white blood cell and platelet counts, diarrhea with bloody flux, and severe anorexia, as was also manifested by the patients who subsequently died. In the rats given both drugs for 6 days, extremely enhanced 5-FU levels were observed from the first day of administration in plasma and in all tissues examined, including bone marrow and intestines. The extreme enhancement of the tissue 5-FU levels was attributable to the facile inactivation by (E)-5-(2-bromovinyl)uracil (BVU) of hepatic dihydropyrimidine dehydrogenase (DPD), a key enzyme regulating the systemic 5-FU level in the rat and human. BVU, a major metabolite formed from SRV by gut flora, was found at considerable levels in the liver of rats orally administered SRV alone or SRV and tegafur, and there was a marked decrease in hepatic DPD activity. In the presence of NADPH, DPD purified from rat liver cytosol was rapidly and irreversibly inactivated by [14C]BVU as a suicide inhibitor with concomitant incorporation of the radioactivity into the enzyme protein, although SRV showed no inhibitory effect on DPD under the same conditions. Human liver DPD was recently demonstrated by us to be inactivated with BVU in a manner very similar to rat DPD.

Animals↗

PubMed1997

Rat liver theta-class glutathione S-transferases T1-1 and T2-2: their chromatographic, electrophoretic, immunochemical, and functional properties.

A method was established for simultaneously isolating Theta-class glutathione (GSH) S-transferases (GSTs) T1-1 and T2-2 as homogeneous proteins from rat (r) liver cytosol. The established method of using an 8-aminooctyl Sepharose 4B column to separate rGSTT1-1 from rGSTT2-2 at the final stage of their purification was a modification of the method previously reported for the isolation of rGSTT2-2 (Hiratsuka et al., J. Biol. Chem., 265, 11973-11981, 1990). Specific substrates used for purification of the Theta-class rGSTs were dichloromethane for T1-1 and 5-sulfoxymethylchrysene for T2-2. rGSTsT1-1 and T2-2 existed at a ratio of 1:7 at a total concentration of 0.5% of that of the cytosolic protein. Purified rGSTsT1-1 and T2-2 were separated as single bands at 28 and 26.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as single peaks at retention times of 36 and 34 min, respectively, by reverse-phase partition high-performance liquid chromatography on a microBondasphere column eluted with a linear gradient of acetonitrile in water containing trifluoroacetic acid. Western blot analysis indicated that rabbit antisera raised against rGSTsT1-1 and T2-2 intensely reacted with the corresponding antigens, but showed no detectable reactivity with the different isoforms of Theta-class rGSTs as well as with representative hepatic rGSTs of other classes. The Theta-class rGSTs showed higher GSH peroxidase activity than rGSTA1-2 toward hydroperoxides of cumene, arachidonic acid, and linoleic acid. Cumene hydroperoxide was a better substrate for rGST T1-1 than for rGST T2-2, while the fatty acid hydroperoxides were the better substrates for rGST T2-2 than for rGST T1-1.

Animals↗

PubMed1997

The RHD gene is highly detectable in RhD-negative Japanese donors.

Recent molecular studies on the Rh blood group system have shown that the Rh locus of each haploid RhD-positive chromosome is composed of two structural genes: RHD and RHCE, whereas the locus is made of a single gene (RHCE) on each haploid RhD-negative chromosome. We analyzed the presence or absence of the RHD gene in 130 Japanese RhD-negative donors using the PCR method. The RhD-negative phenotypes consisted of 34 ccEe, 27 ccee, 17 ccEE, 26 Ccee, 19 CcEe, 1 CcEE, and 6 CCee. Among them, 36 (27.7%) donors demonstrated the presence of the RHD gene. Others showed gross or partial deletions of the RHD gene. These results were confirmed by Southern blot analysis. Additionally, the RHD gene detected in the RhD-negative donors seemed to be intact through sequencing of the RhD polypeptide cDNA and the promoter region of RHD gene. The phenotypes of these donors with the RHD gene were CC or Cc, but not cc. It suggested that there is some relationship between the RHD gene and the RhC phenotypes in RhD-negative individuals. In Caucasian RhD-negative individuals, the RHD gene has not been found outside of the report of Hyland et al. (Hyland, C.A., L.C. Wolter, and A. Saul. 1994. Blood. 84:321-324). The discrepant data on the RHD gene in RhD-negative donors between Japanese and Caucasians appear to be derived from the difference of the frequency of RhD-negative and RhC-positive phenotypes. Careful attention is necessary for clinicians in applying RhD genotyping to clinical medicine.

Base Sequence↗

PubMed1997

Anti-cell death activity promotes pulmonary metastasis of melanoma cells.

Bcl-2 inhibits apoptosis from a variety of stimuli, and a Bcl-2-binding protein BAG-1 also functions in protection from apoptosis in concert with Bcl-2. Here, we provide evidence that prolonged cell survival introduced by overexpression of Bcl-2 or BAG-1 proteins strongly promotes experimental pulmonary metastasis of melanoma B16-BL6 cells. In murine melanoma cell line B16-BL6, gene transfer-mediated expression of the Bcl-2 or BAG-1 led to prolonged cell survival against serum-starved apoptosis in vitro. The Bcl-2-expressing B16 cells, B16-Bcl-2 and the BAG-1-expressing B16 cells, B16-BAG-1 strongly enhanced pulmonary metastasis in allogenic BALB/c nude mice and whole lung weights were increased by 2.4-fold and 1.4-fold, respectively, compared with control transfectants, suggesting that Bcl-2 is a stronger positive modulator of metastasis. When the viable B16-Bcl-2 and control transfectants were injected subcutaneously into BALB/c nude mice, the colony numbers of pulmonary metastasis of the B16-Bcl-2 transfectant increased by 5.6-fold compared with the control transfectants. These enhanced metastatic potentials in the B16-Bcl-2 and the B16-BAG-1 transfectants were well correlated with anti-cell death activity against serum-starvation and enhanced cell viability on limiting dilution. Analysis of the transfectants however revealed that their growth rates, invasive ability and cell motility were not significantly altered by overexpression of either Bcl-2 or BAG-1 proteins. Taken together, these studies demonstrate that prolonged cell survival is a crucial factor to promote metastasis of melanoma, thereby contributing to tumor progression.

Animals↗

PubMed1997

Advanced endometrial cancer detected at 7 months after childbirth.

It is very rare to find endometrial cancers arising within a short period following childbirth, presumably because pregnancy has a protective effect against endometrial cancer mediated by elevated secretion of progesterone. We present the case of a 30-year-old Japanese woman with stage IIIC endometrial cancer that was found 7 months after childbirth. The patient was treated with surgery followed by 6 cycles of intravenous combination chemotherapy and oral administration of medroxyprogesterone acetate. Histopathological examination of surgical specimen revealed poorly differentiated adenosquamous carcinoma of the endometrium with deep myometrial invasion, cervical stromal involvement, and pelvic and paraaortic lymph node metastases. The disease progressed rapidly and the patient died of the disease.

Adult↗