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Biomedical subjects

S Kiyama

Publications and source records attributed to S Kiyama.

54 records · Page 3Linked to original sources
PubMed1990

[A case of secondary amyloidosis complicated with ulcerative colitis].

A 54 year-old woman who had had 4 years history of ulcerative colitis (UC) was admitted to our hospital because of recently developed proteinuria and leg edema. On admission, laboratory findings disclosed massive proteinuria, hypoalbuminemia, acceleration of ESR and elevated of CRP. Her abdominal symptom was remitted. Renal biopsy showed amyloid deposition in glomeruli and arteriole. Amyloid deposition was also found on rectal biopsy. She had no evidence of familial amyloidosis and multiple myeloma. In this case, amyloid deposition might be developed after UC. Secondary amyloidosis due to UC was extremely rare, only 3 cases including ours were reported in Japan.

Amyloidosis↗
PubMed1989

Application of the trimethylsilyl trifluoromethanesulfonate deprotecting procedure for the synthesis of porcine peptide YY (PYY).

A 36-residue peptide amide corresponding to the entire amino acid sequence of porcine peptide YY (PYY) was synthesized by assembling eight peptide fragments of established purity, followed by hard acid deprotection with 1M trimethylsilyl trifluoromethanesulfonate in trifluoroacetic acid. beta-Cycloheptylaspartate, Asp(OChp), was employed to minimize the base-catalyzed succinimide formation. When administered to dogs, synthetic PYY was active as natural peptide in its effects on exocrine pancreatic secretion and pancreatic tissue blood flow.

Amino Acid Sequence↗
PubMed1989

Persistent wedge-shaped low-density lesions on computed tomography of the kidneys without infarction.

A patient with acute lymphoblastic leukemia, who developed acute renal failure, was imaged by computed tomography (CT). Persistent wedge-shaped areas of low attenuation in the kidneys were shown by sequential scans but not areas of infarction were found at autopsy. This case suggests that a wedge-shaped low-density lesion on CT may occur not only in infarcted areas, but also in areas where patchy vasoconstriction occurs.

Acute Kidney Injury↗
PubMed1989

Solution synthesis of human neuropeptide Y (hNPY).

Human neuropeptide Y (hNPY) was synthesized in a conventional manner by assembling seven peptide fragments followed by reduction of the Met(O) residue with phenylthiotrimethylsilane and subsequent deprotection with 1 M trimethylsilyl trifluoromethanesulfonate (TMSOTf)-thioanisole in trifluoroacetic acid (TFA). Alternatively, deprotection was performed in a two-step manner; first, treatment with 1 M trimethylsilyl bromide-thioanisole in TFA, and then with 1 M TMSOTf-thioanisole in TFA. After purification by gel-filtration on Sephadex G-25, followed by reversed-phase high-performance liquid chromatography, a highly purified sample of synthetic hNPY was obtained in both cases. When administered in dogs, synthetic hNPY was as active as porcine NPY in terms of the effects on systemic arterial blood pressure, pancreatic blood flow, and superior mesentric artery (SMA) blood flow. Met(O)17-hNPY was found to be as active as the parent sample in these bioassays.

Amino Acid Sequence↗
PubMed1989

Solution syntheses of two enkephalin-containing peptides, peptide E and dynorphin(1-24), using Nin-(2,4,6-triisopropylphenylsulfonyl)tryptophan.

Two enkephalin-containing peptides, peptide E and dynorphin(1-24), were synthesized by conventional solution methods employing a new Trp derivative, Nin-(2,4,6-triisopropylphenylsulfonyl)tryptophan [Trp(Tps)]. All protecting groups employed including the Tps group were removed by treatment with 1 M trifluoromethanesulfonic acid (TFMSA)-thioanisole in trifluoroacetic acid (TFA) at the final steps of these syntheses. Subsequent purifications by Sephadex G-25 chromatography, CM-Biogel A ion exchange chromatography, and reversed-phase high-performance liquid chromatography afforded highly purified samples. Both synthetic peptide E and dynorphin(1-24) exhibited high in vitro opioid activity. The usefulness of this new tryptophan derivative for practical peptide synthesis was established through these syntheses of complex Trp-containing peptides.

Amino Acid Sequence↗
PubMed1987

Synthesis of porcine neuropeptide Y(NPY) in solution.

The porcine neuropeptide Y (NPY), a 36-residue peptide amide, was synthesized by assembling six peptide fragments followed by thioanisole-mediated deprotection with trifluoromethanesulfonic acid in trifluoroacetic acid. beta-Cycloheptyl aspartate, Asp(OChp), was employed to suppress base-catalyzed succinimide formation. When administered to dogs, the purified peptide (10 micrograms/kg) caused prolonged increase of systemic arterial blood pressure and decreased pancreatic blood flow.

Animals↗
PubMed1984

Studies on peptides. CXIII. Synthesis of the heptacosapeptide amide corresponding to the entire amino acid sequence of chicken secretin.

The heptacosapeptide amide corresponding to the entire amino acid sequence of chicken secretin was synthesized by assembling four peptide fragments followed by deprotection with thioanisole-mediated trifluoromethanesulfonic acid in TFA. The deprotected peptide was purified by gel-filtration on Sephadex G-25, followed by ion-exchange chromatographies on CM-cellulose and DEAE-Sepharose. Synthetic peptide stimulated the flow of pancreatic alkaline juice and decreased systemic blood pressure in rats.

Amino Acid Sequence↗
PubMed1982

Practical gas-liquid chromatographic method for the determination of amino acids in human serum.

Application of the gas--liquid chromatographic method previously reported by us was made to the analysis of the 22 amino acids including asparagine and glutamine in serum. The method permitted that aqueous serum samples obtained after deproteinization with perchloric acid were directly subjected to derivatization without any further clean-up procedure such as ion-exchange chromatography. The N-ethyloxycarbonyl methyl esters, which were prepared in the same manner as the N-isobutyloxycarbonyl methyl esters, were introduced for the determination of leucine, isoleucine, arginine and tyrosine. Both derivatives were prepared by two-step procedures involving alkyloxycarbonylation in aqueous media and esterification with diazomethane, and simultaneously analyzed by using the dual set of columns with the same thermal conditions. The advantages of this method are that the sample pretreatment and derivatization are very simple and rapid, and that both asparagine and glutamine along with other amino acids in serum can be determined.

Amino Acids↗
PubMedDate not supplied

Chemosensitization of human renal cell cancer using antisense oligonucleotides targeting the antiapoptotic gene clusterin.

BACKGROUND: Renal cell cancer (RCC) is a chemoresistant disease with no active chemotherapeutic agent achieving objective response rates higher than 15%. Clusterin is a cell survival gene that increases in human renal tubular epithelial cells after various states of injury and disease. Downregulation of clusterin, using antisense oligonucleotides (ASO), has recently been shown to increase chemosensitivity in several prostate cancer models. The objectives in this study were to evaluate clusterin expression levels in human RCC and normal kidney tissue, and to test whether clusterin ASO could also enhance chemosensitivity in human RCC Caki-2 cells both in vitro and in vivo. METHODS: Immunohistochemical staining was used to characterize clusterin expression in 67 RCC and normal kidney tissues obtained from radical nephrectomy specimens. Northern blot analysis was used to assess changes in clusterin mRNA expression after ASO and paclitaxel treatment. The effects of combined clusterin ASO and paclitaxel treatment on Caki-2 cell growth was examined using an MTT assay. Athymic mice bearing Caki-2 tumors were treated with clusterin ASO alone, clusterin ASO plus paclitaxel, and mismatch control oligonucleotides plus paclitaxel, over a period of 28 days with measurement of tumor volumes once weekly over 8 weeks. RESULTS: Immunohistochemistry of normal and malignant kidney tissue sections of 67 patients demonstrated positive clusterin staining for almost all RCC (98%) and an overexpression, compared to normal tissue, in a majority of RCC (69%). Clusterin ASO, but not mismatch control oligonucleotides, decreased clusterin mRNA expression in Caki-2 cells in a dose-dependent and sequence-specific manner. Pretreatment of Caki-2 cells with clusterin ASO significantly enhanced chemosensitivity to paclitaxel in vitro. Characteristic apoptotic DNA laddering was observed after combined treatment with ASO plus paclitaxel, but not with either agent alone. In vivo administration of clusterin ASO plus paclitaxel acted synergistically to increase apoptosis and significantly delay Caki-2 tumor growth, compared to mismatch control oligonucleotide plus paclitaxel. In addition, TUNEL staining revealed increased apoptotic cells in tumors treated with clusterin ASO plus paclitaxel compared to treatment with either clusterin ASO or paclitaxel alone. CONCLUSION: These findings confirm that the use of clusterin ASO may be a feasible strategy to enhance chemosensitivity for patients with advanced RCC.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

A case of cardiac injury and acute renal failure induced by electrical burn.

Reported is a case of electrical burn associated with cardiac injury and acute renal failure in a 21-year-old man. After coming into contact with a high-tension cable, he became drowsy and oliguria developed. Twenty-four hemodialyses were required. Although the ECG findings revealed an inferior wall myocardial infarction, neither cardiac scintigram (201TlCl) nor ultrasonic cardiography revealed any local lesions. In this case the cardiac damage following electrical burn appeared different from true myocardial infarction.

Acute Kidney Injury↗
PubMedDate not supplied

Crescentic glomerulonephritis associated with renal amyloidosis.

A case of crescentic glomerulonephritis associated with renal amyloidosis is reported. A 62-year-old woman with a 6-yr history of rheumatoid arthritis developed rapidly progressive glomerulonephritis associated with renal amyloidosis and crescent formation. Amyloid protein was positively stained with anti-AA antibody and its fibrils were demonstrated by electron microscopy. In connection with epithelial cell proliferation in the capsular space, destruction of the capillary basement membrane was observed at the sites where amyloid fibrils were accumulated, whereas glomerular deposition of immunoglobulin and complement was not detected. It is conceivable that the destruction of the glomerular tufts induced by amyloid deposition may be responsible for the crescent formation.

Amyloidosis↗