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Biomedical subjects

Y Shibuya

Publications and source records attributed to Y Shibuya.

At least 19 recordsLinked to original sources
PubMed2000

Whale high-molecular-weight and low-molecular-weight kininogens.

The expression of high-molecular-weight and low-molecular-weight kininogen mRNAs in the whale liver was examined by reverse transcription-polymerase chain reaction. The nucleotide sequences of the high-molecular-weight and low-molecular-weight kininogen cDNAs were analyzed and deduced to the amino acid sequences. The high-molecular-weight kininogen composed of 609 amino acid residues with 18 signal peptides possessed the consensus sequences of the cysteine protease inhibitor domains I and II, the bradykinin domain, the histidine-rich region, and the prekallikrein-binding region. Except for the histidine-rich region, the overall homologies with bovine, human, and rat high-molecular-weight kininogens were 81%, 76%, and 62%, respectively. The low-molecular-weight kininogen is composed of 408 amino acid residues. The nucleotide sequence down to C(1200) as well as the amino acid sequence till Ile(382) is identical to that of the high-molecular-weight kininogen. The remaining low-molecular-weight kininogen-specific carboxy-terminal portion possessed an amino acid sequence similar to that of the land mammals. The overall homologies with bovine, human, and rat low-molecular-weight kininogens were 82%, 79%, and 64%, respectively. The amino acid sequences of both whale high-molecular-weight and low-molecular-weight kininogens are most similar to those of the bovine among the land mammals analyzed so far. An incubation of dolphin/whale plasma with human plasma kallikrein, or with bovine trypsin, in the presence of carboxypeptidase inhibitors generated bradykinin antigen as well as the spasmogenic activity to the estrous rat uterus. The amount of bradykinin released by the latter enzyme was almost double of the former, indicating that the dolphin/whale plasma contained similar concentrations of low-molecular-weight and high-molecular-weight kininogens.

Amino Acid Sequence↗
PubMed2000

Markedly increased unilateral intraocular pressure during hemodialysis in a patient with ipsilateral exfoliative glaucoma.

PURPOSE: To report a man with markedly increased intraocular pressure in a unilateral exfoliated eye during hemodialysis. METHOD: Case report. RESULTS: A 75-year-old man with unilateral exfoliative glaucoma complained of blurred vision in his right eye during hemodialysis. The blurred vision always occurred during hemodialysis, and the intraocular pressure was increased during hemodialysis. The average increase in intraocular pressure during hemodialysis in the right eye was 22.5 mm Hg, and the intraocular pressure in the left eye remained in the normal range during hemodialysis. Argon laser trabeculoplasty was performed on the right eye, and a decrease in intraocular pressure was attained. CONCLUSION: Physicians must be alert to intraocular pressure increases in these eyes during hemodialysis.

Aged↗
PubMed1999

Primary structure of guinea pig plasma prekallikrein.

A full length guinea pig plasma prekallikrein (PK) cDNA was cloned from a liver cDNA library. The nucleotide sequence with 2242 bp was analyzed and the amino acid sequence with 618 residues was deduced. Kallikrein was purified from guinea pig plasma and cleavage site in the activation was determined. The amino acid sequence around the cleavage site -368Ile-Asp-Ala-Arg-Ile-Val-Gly-375Gly- differed from that of the human PK -368Thr-Ser-Thr-Arg-Ile-Val-Gly-375Gly-. Protease substrates containing penta-peptides which mimicked the sequence of the cleavage sites from P3 to P2' of guinea pig Hageman factor (HF) and PK were synthesized, and kinetic analyses of the hydrolysis by guinea pig activated HF (HFa) and kallikrein were carried out. The combination between HFa and the PK mimicking peptide provided the best kinetics. These results in part explain why the cascade activation of PK by HFa is predominant in the guinea pig system.

Amino Acid Sequence↗
PubMed1999

Blood-retinal barrier and autofluorescence of the posterior polar retina in long-standing pseudophakia.

PURPOSE: To study the physiological state of the retina in long-standing pseudophakic eyes using blood-retinal barrier (BRB) disruption and autofluorescence as parameters. SETTING: Miyake Eye Hospital, Nagoya, Japan. METHOD: This retrospective, case-controlled study sought to determine whether ultraviolet (UV)-light-filtering and blue-light-filtering intraocular lenses (IOLs) had different outcomes in severity of BRB disruption and autofluorescence of the posterior polar retina than clear (untreated) IOLs. RESULTS: Mean sodium fluorescein transmittance in eyes with untreated IOLs was 3.7 ng/mL +/- 2.2 (SD) 3 years after surgery (n = 40) and 3.5 +/- 1.8 ng/mL 8 years after surgery (n = 18). In eyes with a UV-filtering IOL, the values were 2.4 +/- 1.5 ng/mL (n = 39) and 2.6 +/- 2.0 ng/mL (n = 14), respectively. Eyes with a UV-filtering IOL had significantly lower transmittance (P < .01-< .05). Mean transmittance 5 years after surgery was 4.2 +/- 1.9 ng/mL in eyes with an untreated IOL (n = 31), 3.2 +/- 2.1 ng/mL in eyes with a UV-filtering IOL (n = 30), 2.8 +/- 1.9 ng/mL in eyes with a Menicon blue-light-filtering IOL (n = 20), and 2.6 +/- 1.8 ng/mL in eyes with a Hoya blue-light-filtering IOL (n = 21). The eyes with a UV-filtering and the blue-light-filtering IOLs had significantly lower transmittance than those with an untreated IOL (P < .01-< .05); the eyes with a Hoya IOL had a statistically lower mean than those with the UV-filtering IOL (P < .05). Mean autofluorescence was 44.9 +/- 6.8 (n = 14), 49.5 +/- 6.1 (n = 6), 53.0 +/- 11.9 (n = 15), and 64.5 +/- 13.2 (n = 7) at 1, 4, 9, and 14 years after surgery, respectively; there was a significant difference between 1 and 9 years and between 1 and 14 years (P < .05). CONCLUSION: Eyes with a UV-filtering or blue-light-filtering IOL had a lower incidence of BRB disruption than eyes with an untreated IOL. Autofluorescence increased with age, even in eyes with UV-filtering IOLs.

Aged↗
PubMed1999

Tumor-doubling time and onset of pulmonary metastasis from adenoid cystic carcinoma of the salivary gland.

Adenoid cystic carcinoma (ACC), an uncommon malignancy in the head and neck region, invades diffusely and often metastasizes to the lung, although the growth rate is very slow. A retrospective study was conducted in 30 patients with ACC to ascertain the frequency of pulmonary metastasis, the doubling time of metastatic tumor deposits, and the time of onset for pulmonary metastasis. The following results were obtained: (1) Of 30 patients with ACC, 21 had pulmonary metastases (4 initially and 17 during observation), 7 were free of metastases but have not been observed for 5 years, and 2 were free of metastases for more than 5 years but less than 10 years after the initial treatment. The cumulative metastasis rate at 5 and 10 years for this group of patients was 70% and 100%, respectively. (2) Patients with T1 or T2 tumors that have a tubular or cribriform histopathologic pattern showed pulmonary metastases about 20 months later than those with T3 or T4 tumors and a solid pattern. However, the final metastasis rate did not differ between the 2 groups after a long period. (3) The tumor doubling time of the metastatic deposits of ACC was 86 to 1064 days with an average of 393 days, which was much longer than that of most other malignant neoplasms reported previously. (4) The time of onset of pulmonary metastasis was calculated to be much earlier (average of 227 months) before the first visit. These findings suggest that the treatment method for ACC should be chosen with the consideration that many of the patients may have occult pulmonary metastases at the time of their initial evaluation.

Carcinoma, Adenoid Cystic↗
PubMed1999

Ultrastructural localization of E-cadherin and alpha-/beta-catenin in adenoid cystic carcinoma.

AIMS: To investigate the disturbance of intercellular adhesion in adenoid cystic carcinoma (ACC), we examined the ultrastructural localization of E-cadherin (E-cad), alpha-catenin (alpha-cat) and beta-catenin (beta-cat) in ACC, and compared it with that in the normal labial gland. METHODS AND RESULTS: Using immuno-electron microscopy, in the normal labial gland, E-cad was found to be uniformly distributed along the plasmalemma, where cells were in close contact with each other, with junctional complexes, desmosomes and interdigitations; expression of alpha-cat and beta-cat was also detected. In ACC, which was classified into tubular, cribriform and trabecular types, E-cad expression seemed not to be uniform, but was observed to be along the plasmalemma where cell-to-cell contact was made. On the other hand, expression of alpha-cat or beta-cat was uneven in the trabecular-type cells which were very slender and grew in an infiltrative scattered pattern into the extracellular matrix; that was absent in the cribriform-type cells which made contact with each other mostly at the tip of the cytoplasmic processes. CONCLUSION: These findings suggest that the neoplastic cells of ACC express E-cad for use in intercellular adhesion, but the cadherin-catenin complex might not operate properly, which is the cause of neoplastic cell dissociation, followed by invasion and metastasis.

Adult↗
PubMed1999

Gallates inhibit cytokine-induced nuclear translocation of NF-kappaB and expression of leukocyte adhesion molecules in vascular endothelial cells.

Gallates (gallic acid esters) belong to the class of phenolic compounds, which are abundant in red wine. In this study, we show that gallates can inhibit cytokine-induced activation of nuclear factor kappaB (NF-kappaB) and thereby reduce expression of endothelial-leukocyte adhesion molecules in cultured human umbilical vein endothelial cells (HUVECs). Pretreatment of HUVECs with ethyl gallate (3 to 10 micromol/L) significantly suppressed interleukin-1alpha (IL-1alpha)- or tumor necrosis factor-alpha (TNF-alpha)- induced mRNA and cell-surface expression of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin, which was associated with reduced adhesion of leukocytes to HUVECs. Gel shift assays with the NF-kappaB consensus sequence showed the decreased densities of the shifted bands in gallate-treated HUVECs. Furthermore, gallate pretreatment inhibited cytokine-induced transcription of a fusion gene, which consisted of 4 repeats of the NF-kappaB consensus sequence and the luciferase reporter gene. Immunoblot analysis of nuclear extracts and whole-cell lysates demonstrated the decreased amounts of NF-kappaB p65 in nuclei but equal amounts of inhibitor-kappaBalpha (I-kappaBalpha) in whole-cell lysates of ethyl gallate-treated HUVECs. Incubation of the nuclear extracts from cytokine-activated HUVECs with ethyl gallate did not affect the NF-kappaB shifted bands induced by cytokines in gel shift assays. Taken together, these data demonstrate that ethyl gallate can inhibit cytokine-induced nuclear translocation of NF-kappaB p65 by way of a mechanism independent of I-kappaBalpha degradation and thereby suppress expression of VCAM-1, ICAM-1, and E-selectin, which was associated with reduced adhesion of leukocytes. These results in vitro demonstrate that gallates can exhibit anti-inflammatory properties by blocking activation of NF-kappaB and suggest that these natural compounds, abundant in red wine, may play important roles in the prevention of atherosclerosis and inflammatory responses in vivo.

Arteriosclerosis↗
PubMed1998

Whale Hageman factor (factor XII): prevented production due to pseudogene conversion.

In Southern blot analysis of the Hind III-digested whale genomic DNA obtained from the livers of two individual whales, we detected a single band with a size of five kilobase pairs which hybridized to full length guinea pig Hageman factor cDNA. We amplified two successive segments of the whale Hageman factor gene by polymerase chain reaction (PCR), and sequenced the PCR products with a combined total of 1367 base pairs. Although all of the exon-intron assemblies predicted were identical to those of the human Hageman factor gene, there were two nonsense mutations making stop codons and a single nucleotide insertion causing a reading frame shift. We could not detect any message of the Hageman factor gene expression by northern blot analysis or by reverse transcription-polymerase chain reaction (RT-PCR) analysis. These results suggest that in the whale, production of the Hageman factor protein is prevented due to conversion of its gene to a pseudogene. The deduced amino acid sequence of whale Hageman factor showed the highest homology with the bovine molecule among the land mammals analyzed so far.

Amino Acid Sequence↗
PubMed1998

Strict dietary sodium reduction worsens insulin sensitivity by increasing sympathetic nervous activity in patients with primary hypertension.

To assess the effects of sodium reduction on insulin sensitivity in hypertension, we examined the change of insulin sensitivity after two degrees of dietary sodium restriction by the euglycemic hyperinsulinemic glucose clamp method in 12 subjects with primary hypertension. A controlled period of 1 week, when the subjects were taking a normal sodium diet, was followed by a randomized crossover study in which the subjects were placed on either moderate or strict reduced sodium diets for 1 week. The result of the 1-week moderate dietary sodium reduction from 200 to 100 mmol/day showed significant decreases in systolic and diastolic blood pressure by 6.5 and 5.0 mm Hg, respectively. Strict dietary sodium reduction to 30 mmol/day for 1 week resulted in no further decrease in blood pressure, but it increased plasma insulin by 40.6% without changing plasma glucose. There were no changes in glucose infusion rate (GIR) or insulin sensitivity index (ISI), which is a measure of GIR divided by plasma insulin, after moderate dietary sodium reduction. However, strict dietary sodium reduction induced decreases in GIR by 19.8% (from 1318+/-189 to 1057+/-173 micromol/m2/ min; P < .01), and ISI by 20.5% (from 16.6+/-2.1 to 13.2+/-1.9 micromol/m2/min/microU/mL; P < .01) with a paralleled increase of plasma norepinephrine by 90.0% (from 150.5+/-61.6 to 287.3+/-114.9 pg/mL; P < .01). These results indicate that dietary sodium restriction leads to a deterioration of insulin sensitivity when plasma norepinephrine levels increase, and suggest that moderate dietary sodium reduction may lower blood pressure without a distinct adverse effect on glucose metabolism in subjects with primary hypertension.

Adult↗
PubMed1998

A case of microphthalmos with cyst and partial trisomy 22.

A 13-day-old girl was referred for evaluation of a right orbital mass. Ophthalmic examinations revealed microphthalmia with cyst in the right eye and microphthalmia in the left eye. She had lowset ears, auricular fistula, micrognathia, and muscular hypotonia. Chromosomal analysis using fluorescence in-situ hybridization (FISH) showed partial trisomy 22. To our knowledge, microphthalmos with cyst associated with partial trisomy 22 has not been described previously in the English literature. Repeated aspiration resulted in a decrease in size of the cyst.

Chromosomes, Human, Pair 22↗
PubMed1998

Ratio of CD44 epithelial variant to CD44 hematopoietic variant is a useful prognostic indicator in gastric and colorectal carcinoma.

BACKGROUND: The CD44 is a cell adhesion molecule that is present as numerous isoforms created by mRNA alternative splicing. Expression of variant isoforms of CD44 is associated with tumor growth and metastasis. The aim of this study was to evaluate whether CD44 isoform expression is a prognostic factor in gastric and colorectal cancer. METHODS: We performed a polymerase chain reaction analysis following reverse transcriptase treatment for CD44 expression in fresh surgical specimens obtained from 25 colon carcinomas and 30 gastric carcinomas and matched adjacent normal mucosa. We determined the epithelial variant/hematopoietic variant (E/H) ratio (the amount of the CD44 epithelial variant transcript relative to the CD44 hematopoietic variant transcript) in cancer tissues and examined it for correlations with clinicopathological parameters and survival rate. RESULTS: The E/H ratio in tumor tissue was significantly higher than that in adjacent non-cancerous mucosa. In gastric and colorectal cancer tissues, there was no significant relationship between E/H ratio and clinicopathological parameters. However, patients who died due to tumor recurrence had a higher E/H ratio than surviving patients with colorectal cancer. In gastric cancer, patients with high E/H tumors had a shorter survival time than those with low E/H tumors. CONCLUSIONS: Our results suggest that the E/H ratio is a useful indicator of prognosis in gastric and colorectal carcinoma.

Adult↗
PubMed1998

Parathyroid-hormone-related-protein-producing thymic carcinoma presenting as a giant extrathoracic mass.

A 53-year-old female with a 9-month history of chest pain presented with a giant anterior chest wall mass. Radiologic examination showed an anterior mediastinal tumor invading the chest wall. Serum calcium and parathyroid hormone-related protein (PTHrP) levels were extremely elevated. Biopsy specimens disclosed a squamous cell carcinoma with Hassall's corpuscle-like keratotic pearls, and an immunohistological study showed a positive staining with PTHrP. The tumor and serum PTHrP concentration markedly decreased following cisplatin-based chemotherapy and radiation. This is the first case of PTHrP producing a thymic carcinoma with the unusual presentation of a large extrathoracic mass.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Effects of O-glycosylation inhibitors on the differentiation of HL-60 cells.

The effects of O-glycosylation inhibitors on the growth and differentiation of the human acute promyeloblastic leukemia cell line HL-60 were studied to examine whether the O-glycosylation is needed for HL-60 cells to differentiate into granulocyte-like cells or monocyte-macrophage-like cells. N-Acetyl-alpha-D-galactosaminides, inhibitors of mucin-type oligosaccharide synthesis, and N-acetyl-beta-D-galactosaminides did not affect either growth or differentiation. beta-D-Xylosides, the artificial initiators of glycosaminoglycan synthesis, also were tested. Only 4-methylumbelliferyl-beta-D-xyloside induced HL-60 cells, to differentiate, and they differentiated into granulocyte-like cells, assessed by reduction of nitroblue tetrazolium, Giemsa staining, and esterase double-staining. The aglycon portion of 4-methylum-belliferyl-beta-D-xyloside, 4-methylumbelliferone, caused the differentiation. Thus we could find a new drug that induces the differentiation of HL-60 cells.

Antimetabolites, Antineoplastic↗
PubMed1998

A monocyte chemotactic factor, S19 ribosomal protein dimer, in phagocytic clearance of apoptotic cells.

HL-60 cells derived from a human promyelocytic leukemia underwent apoptosis by heat treatment. When the heat-treated HL-60 cells were injected into guinea pig skin, monocyte/macrophage infiltration was observed 24 or 36 hours later, and the apoptotic cells were phagocytically cleared by 48 hours after their injection. The infiltration and clearance patterns were quite different from those observed in injection of necrotic or boil-fixed HL-60 cells. The apoptotic cells released a monocyte chemotactic factor in vitro 24 hours after the heat treatment. The chemotactic factor generated was identified as the cross-linked homodimer of S19 ribosomal protein by its immunologic and physicochemical properties. A serine protease that inactivates the monocyte chemotactic factor was also released from the apoptotic cells 30 hours after the heat treatment. A super infusion of this protease into the skin where the apoptotic cells had been injected diminished the number of infiltrated monocytes. The present results indicate an important role of the S19 ribosomal protein dimer in the phagocytic clearance of apoptotic cells.

Animals↗
PubMed1998

[A case of sea water and sand aspiration during near drowning].

A 46-year-old man who had been pulled under water by a tidal wave when an earthquake occurred on July 12, 1993 was carried to our hospital the next day. He soon needed endotracheal intubation and mechanical ventilation because he expectorated sputa with sand and because arterial bloodgas analysis revealed severe hypoxemia. Chest X-ray on admission showed diffuse small nodules and areas of consolidation. Chest CT obtained on July 16 showed centrilobular small nodules bilaterally and alveolar opacities in the peribronchial region. After therapy with antibiotics and frequent bronchial lavages, sputum with sand disappeared on the 14 th hospital day and chest X-ray film and laboratory data showed marked improvement. He was discharged on October 1. A chest CT scan obtained on February 17, 1994 showed improvement of the small nodules. The areas of consolidation had also improved, but remained as linear and nodular opacities, which were considered to be organized lesions. There are few reports concerning radiographic findings particularly CT findings, after aspiration of sea water and sand during near drowning.

Anti-Bacterial Agents↗
PubMed1998

S19 ribosomal protein cross-linked dimer causes monocyte-predominant infiltration by means of molecular mimicry to complement C5a.

S19 ribosomal protein is a component of the protein-producing machinery, ribosome. When recombinant S19 proteins were cross-linked intermolecularly by plasma transglutaminase (coagulation factor XIIIa), this homodimer newly exhibited monocyte chemotactic activity. This effect was specific to monocytes. The S19 protein homodimer shared the immunoreactivity with the complement-derived chemotactic factor, component 5a (C5a). Monocytes pretreated with an anti-C5a receptor antibody or with a synthetic C5a receptor antagonist responded poorly in chemotaxis to this homodimer. These data indicate that the S19 protein homodimer possesses a 3-dimensional structure similar to C5a in terms of the immunologic epitope and the receptor ligand, although homology between their primary structures is only 4%. In contrast, the S19 protein homodimer did not attract polymorphonuclear leukocytes. In addition, the homodimer inhibited a chemotactic response of polymorphonuclear leukocytes to C5a in vitro and in vivo as a receptor antagonist. Furthermore, the S19 protein homodimer competitively inhibited the binding of radiolabeled C5a to polymorphonuclear leukocytes. The S19 protein homodimer with these opposite effects in the leukocyte chemotaxis seems to induce the monocyte/macrophage predominant infiltration in chronic inflammation.

Animals↗