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Biomedical subjects

Y Shibuya

Publications and source records attributed to Y Shibuya.

At least 19 recordsLinked to original sources
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↗
PubMed1997

Comparison of immunostainings for proliferating cell nuclear antigen and Ki-67 in human extraocular lesions.

BACKGROUND: Cell kinetic information is helpful to understand disease progression, treatment response, and prognosis of the neoplasms. To compare the usefulness and limitations of antibodies that recognize the cell cycle-associated molecules, proliferating cell nuclear antigen (PCNA) and Ki-67, we performed immunostaining in formalin-fixed, paraffin-embedded tissue sections of extraocular lesions. METHODS: Specimens were obtained from patients undergoing routine surgical procedures. Formalin-fixed, paraffin-embedded sections were stained for PCNA and Ki-67 using the monoclonal antibodies PC10 and MIB-1, respectively. Microwave oven heating for antigen retrieval was performed before immunostaining. RESULTS: In squamous cell carcinomas and basal cell carcinomas, PCNA immunostaining varied greatly. Basal cells of benign epithelial lesions showed moderate to weak PCNA staining. Strong PCNA immunoreactivity was demonstrated in foci of inflammation and germinal centers. Microwave processing enhanced the intensity of those PCNA immunostainings. As the PCNA immunostaining intensity had a great variability, the absolute numbers of PCNA-positive cells were hard to count in some tissues. High Ki-67 counts were observed in squamous cell carcinomas, foci of inflammatory cells, and germinal center cells. Basal cell carcinomas and benign lesions showed low Ki-67 counts. Every section showed clear nuclear staining in Ki-67 immunostaining. CONCLUSION: Careful consideration is required in the assessment of cell proliferation using PCNA. The immunostaining of Ki-67 may be more accurate than that of PCNA for evaluating cell proliferation in formalin-fixed, paraffin-embedded tissues.

Animals↗
PubMed1997

Choroidal osteoma in an infant.

PURPOSE: To report an 8-month-old infant with choroidal osteoma. METHOD: Case report. RESULTS: The patient, who had bilateral yellow stippling at the posterior pole, was followed up for 8 years. Both fundi developed creamy, irregular scalloped lesions. Computed tomography showed a bony plate at the posterior pole bilaterally. CONCLUSION: We believe that this is the youngest patient reported to have choroidal osteoma.

Bone Neoplasms↗
PubMed1997

Endometrial carcinoma in a patient with blepharophimosis syndrome and menstrual abnormality.

PURPOSE: To describe a woman with blepharophimosis syndrome and menstrual abnormality who developed endometrial carcinoma. METHODS: A 26-year-old woman with blepharophimosis syndrome and menstrual abnormality had increased serum luteinizing hormone and serum follicle-stimulating hormone levels. She was followed up for 5 years. RESULT: She developed endometrial carcinoma. CONCLUSIONS: Patients with blepharophimosis syndrome and menstrual abnormality should be examined gynecologically. Hormone-dependent endometrial carcinoma may develop.

Adenocarcinoma↗
PubMed1997

Serum and BAL Clara cell 10 kDa protein (CC10) levels and CC10-positive bronchiolar cells are decreased in smokers.

Cigarette smoking has diverse effects on the structure and function of the lung. Smoking appears to reduce the levels of Clara cell 10 kDa protein (CC10) in the alveolar lining fluid, but the influence of smoking serum on CC10 levels is still debated, and it has not been clear whether smoking reduces the number of CC10-producing lung cells. The aims of this study were to clarify the influence of smoking on CC10 levels in the alveolar lining fluid and bloodstream, and on the number of CC10-producing lung cells. CC10 concentrations were measured in sera and bronchoalveolar lavage (BAL) fluids, by means of enzyme-linked immunosorbent assay using monoclonal and polyclonal antibody, and the immunohistochemical expression of CC10 was examined in the lungs of nonsmokers and smokers using the monoclonal antibody, TY-5, against CC10/human urinary protein-1. CC10 concentrations in sera and in BAL fluids from healthy smokers were significantly lower than in healthy nonsmokers. Immunohistochemical expression of CC10 was found exclusively in nonciliated bronchiolar epithelial cells. As compared to that of nonsmokers, the mean percentage of CC10-positive bronchiolar epithelial cells was significantly decreased in lung tissue specimens obtained from smokers who had normal results in pulmonary function tests. It was concluded that smoking reduces the proportion of Clara cell 10 kDa protein-producing bronchiolar epithelial cells, resulting in decreased levels of Clara cell 10 kDa protein in the lower respiratory tract and in the bloodstream. The protein is a new blood biochemical and immunohistochemical marker, reflecting structural changes in peripheral airways induced by cigarette smoking.

Adult↗
PubMed1997

[A case of localized pleural mesothelioma].

Localized pleural mesothelioma is reported. A 62-year-old male had been observed as a patient with old tuberculosis of the left lung for a few decades. For detailed examination of fever of unknown cause and abnormal shadow on the chest X-ray, the patient was introduced to our hospital. By percutaneous cytodiagnosis, the illness was diagnosed as pleural mesothelioma, and the patient underwent surgery. Since adhesion of the tumor to the lower lobe of the lung was extremely tight, the tumor and the left lower lobe were resected as a mass. The tumor was about 15 cm in diameter, weighed 1,300 g and a slight pleural effusion was observed. The tumor was diagnosed as malignant localized pleural mesothelioma pathologically. Localized pleural mesothelioma should be subjected to surgery in the early stage, in principle. Even in cases difficult to diagnose, operation should not be delayed by repeating easy-going needle-biopsy or a long-term treatment with antitubercular drugs. The postoperative course of this case has been good, and no recurrence nor metastasis has been detected.

Humans↗
PubMed1996

Monocyte chemotactic factor in rheumatoid arthritis synovial tissue. Probably a cross-linked derivative of S19 ribosomal protein.

The extracts of rheumatoid arthritis-synovial lesions from seven patients possessed a strong chemotactic activity for monocytes and a negligible one for polymorphonuclear leukocytes. These results are consistent with a prominent histological feature of the synovial lesion, the mononuclear cell predominant infiltration. The major monocyte chemotactic factor in the synovial tissue extracts was purified to a single protein peak in reverse phase high performance liquid chromatography with a C4 column. NH2-terminal amino acid analysis of the initial 20 residues yielded a single sequence. Surprisingly, this sequence was completely identical to that of S19 ribosomal protein. The purified sample demonstrated two protein bands in SDS-polyacrylamide gel electrophoresis with apparent molecular masses of 34 and 68 kDa. These sizes were 2 and 4 times that of S19 ribosomal protein, suggesting that the chemotactic factor would be a dimer or tetramer of S19 ribosomal protein cross-linked by factor XIIIa. A recombinant human S19 ribosomal protein was prepared as a fusion protein with a maltose binding protein in Escherichia coli. After treatment with factor XIIIa, cross-linked recombinant S19 ribosomal protein exhibited the monocyte chemotactic activity, although the untreated recombinant protein did not.

Amino Acid Sequence↗
PubMed1996

Alpha N-catenin expression in the normal and regenerating chick sciatic nerve.

The Ca(2+)-dependent intercellular adhesion molecule cadherin is known to be linked to the cytoskeleton by the protein catenin, an association of which appears to be important for the cell-adhesion function of cadherin. Catenin consists of three subtypes-alpha, beta, and gamma. In our previous study, N-cadherin was shown to be localized on the plasmalemma of normal and regenerating chick peripheral nerve. Thus, as alpha N-catenin is a subtype of alpha-catenin (which is specifically associated with N-cadherin), we investigated the immunolocalization of alpha N-catenin in normal and regenerating chick sciatic nerve. In normal nerve, unmyelinated axons exhibited either intense or weak alpha N-catenin immunoreactivity throughout the axoplasm, whereas myelinated axons were completely immunonegative. Regenerating axons, including those derived from parent myelinated axons, showed alpha N-catenin immunoreactivity of variable intensities in growth cones and axon shafts. Schwann cells were invariably devoid of immunoreactivity. Thus alpha N-catenin is not necessarily bound to the surface plasmalemma, but is distributed throughout the cytoplasm, suggesting that most alpha N-catenin molecules are dissociated from N-cadherin.

Animals↗
PubMed1996

Species differences in amino acid sequences of Hageman factor and prekallikrein at region around scissile bond in activation.

The initial step in activation of the plasma kinin system is activation of Hageman factor (coagulation factor XII) and/or plasma prekallikrein. Two types of activation mechanisms, contact activation on a negatively charged surface and a cascade activation by exogenous proteases are known. Since these factors are serine protease zymogens, the activation of these molecules usually results from the cleavage of a particular -Arg-Ile(Val)- bond in either mechanism. Hence, these zymogens are regard to be substrates of their activator proteases. Sensitivity of the substrate for the protease basically depends on the amino acid sequence of six to eight residues around the scissile bond of the substrate. We found different activation efficiencies of these zymogens between human and guinea pig in both types of activation, and micro-heterogeneity of the sequence around the scissile bond among human, guinea pig and bovine Hageman factors, or between human and guinea pig prekallikreins. The sequence heterogeneity may explain the different activation efficiencies of these zymogens among mammalian species.

Amino Acid Sequence↗