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Biomedical subjects

K Hiwada

Publications and source records attributed to K Hiwada.

443 records · Page 25Linked to original sources
PubMedDate not supplied

Role of glandular kallikrein in the activation process of human plasma inactive renin.

Completely inactive renin was isolated from normal human plasma by DEAE-Sepharose column chromatography and Blue-Sepharose column chromatography. This inactive renin had a molecular weight of 54,000 daltons as determined by gel filtration on Ultrogel AcA 44. When the inactive renin was activated by trypsin, its molecular weight decreased to 48,000 daltons. The trypsin-activated renin differed from a native form of active renin in plasma with respect to molecular weight (active renin, 43,000), pI value (active renin, 5.20; trypsin-activated renin, 5.06), km value (active renin, 60 nmoles/liter; trypsin-activated renin, 89 nmoles/liter), Ki value for pepstatin A (active renin, 2.6 mumoles/liter; trypsin-activated renin 5.0 mumoles/liter) and pH profile for angiotensin formation. Glandular kallikrein (human urinary or pig pancreatic) did not activate the inactive renin. When the trypsin-activated renin was treated with glandular kallikrein, its activity was unchanged, but its molecular and kinetic properties except pI value (trypsin-activated kallikrein-treated renin, 4.82) coincided with those of a native form of active renin in plasma. These results indicate that glandular kallikrein does not directly activate inactive renin but participates in the activation process of inactive renin. The results also suggest that inactive renin in human plasma is a renin precursor.

Chromatography↗
PubMedDate not supplied

Highly potent and specific inhibitors of human renin.

Small peptide analogues representing the C-terminal portion of angiotensin I sequence were designed as inhibitors of human renin. Among synthesized compounds, benzyloxycarbonyl (-"Z")-(1-naphthyl)Ala-His-leucinal (ES-188), Z-(1-naphthyl)Ala-His-statine ethyl ester (ES-226), and Z-(1-naphthyl)Ala-His-statine 2-methylbutylamide (ES-254) markedly inhibited human and primate renins (inhibitory concentration, 50% [IC50], near 10(-7) M). These peptide analogues inhibited rabbit renin with one or two orders of magnitude less potency. They were very weak inhibitors of renins from pig, goat, dog, and rat. ES-188 had no discernible effect on cathepsin D, pepsin, or human angiotensin-converting enzyme at the concentration of 10(-4)M. ES-226 had little effect on the three enzymes at the concentration of 10(-5)M; however, ES-254 had a considerable inhibitory effect on cathepsin D (IC50 of 1.4 X 10(-5)M), pepsin (IC50 of 4.2 X 10(-5)M), and human angiotensin-converting enzyme (IC50 of 7.1 X 10(-6)M). Our results indicate that 1-naphthylalanine-containing tripeptide analogues are highly potent human renin inhibitors.

Angiotensin I↗
PubMedDate not supplied

A high level of CCAAT-enhancer binding protein-delta expression is a major determinant for markedly elevated differential gene expression of the platelet-derived growth factor-alpha receptor in vascular smooth muscle cells of genetically hypertensive rats.

-Platelet-derived growth factor-alpha receptor (PDGF-alphaR) expression is markedly elevated in cultured vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) when compared with normotensive rat strains, Sprague-Dawley, Wistar, and Wistar-Kyoto rats (WKY). This "almost-all-or-none" type of differential expression strongly suggests that PDGF-alphaR or its transcription-regulating mechanisms or factors are significantly related to genetic hypertension. To evaluate the role of PDGF-alphaR in vascular remodeling and hypertension, we have investigated the underlying molecular mechanism. We have recently shown that the regulatory domain responsible for this difference is localized to the PDGF-alphaR promoter region between -246 and -139, which contains an enhancer core sequence specific for CCAAT-enhancer binding proteins (C/EBPs). We defined the roles of this element for hypertensive strain-specific PDGF-alphaR gene transcription. DNA-protein binding studies by competition in electromobility shift and supershift assays revealed that 2 members, C/EBP-beta and C/EBP-delta, are mainly responsible for DNA-protein complex formation; the former acts as a transcriptional repressor and the latter as an activator of the PDGF-alphaR gene, respectively. Western or Northern blot analyses supported evidence for high expression of C/EBP-delta seen only in SHR-derived VSMCs. Furthermore, forced expression of C/EBP-delta transactivated the transcriptional efficiency of the PDGF-alphaR gene even in WKY-derived VSMCs, whereas that of C/EBP-beta had an opposite effect in SHR-derived VSMCs. These findings indicate that differential expression of members of the C/EBP family, mainly C/EBP-delta and possibly C/EBP-beta, are responsible for the strain-specific gene transcription of PDGF-alphaR in VSMCs.

Animals↗
PubMedDate not supplied

Total lipodystrophy with heart failure and renal failure: report of a case.

A 38-year-old female was admitted to our hospital because of dyspnea. The diagnosis of total lipodystrophy was made by following findings: (1) gaunt appearance; (2) insulin-resistant diabetes mellitus; (3) hyperlipidemia; (4) fatty liver. Chest X-ray demonstrated cardiomegaly, pulmonary edema and pleural effusion. Echocardiogram was characterized by left ventricular hypertrophy with asymmetrical septal hypertrophy and left ventricular dysfunction. Renal biopsy revealed focal glomerulosclerosis. We reported a patient with total lipodystrophy combined with heart failure and renal failure, which have been rarely associated with the disease.

Adult↗
PubMedDate not supplied

A case of isolated thyrotropin deficiency with Cushing's syndrome.

The first case of isolated thyrotropin (TSH) deficiency with Cushing's syndrome was reported. A 46-year-old female was admitted to our hospital because of fatigability, puffy eye-lids, leg edema and petechia. She was treated with thyroid hormone. A low free triiodothyronine continued. Serum TSH was undetectable and serum thyrotropin releasing hormone (TRH) was elevated. No response of serum TSH and normal response of serum prolactin after administration of exogenous TRH suggested the abnormalities of anterior pituitary gland. The secretion of growth hormone and gonadotropin were intact, but the secretion of adrenocorticotropic hormone (ACTH) was impaired. A high level of serum cortisol, no response of serum ACTH by metyrapone test and a tumor mass of abdomen detected by computed tomography led to the diagnosis of Cushing's syndrome. Histological examination of the tumor revealed adrenal adenoma. Twenty two months after the surgery, serum ACTH level was normalized, but the secretion of serum TSH to exogenous TRH was still absent. The results indicated that hypothyroidism in our patient was due to isolated TSH deficiency.

Adenoma↗
PubMedDate not supplied

Asymptomatic hereditary xanthinuria: a case report.

A 22-year-old man with hereditary xanthinuria is reported. A biochemical study of the patient showed elevated serum levels of xanthine and hypoxanthine with concomitant increases in urinary excretion of xanthine and hypoxanthine. The xanthine oxidase activity in the duodenal mucosa of the patient was about 1.5% of normal value. Urinary excretion of xanthine and hypoxanthine of his parents and his eldest brother were significantly higher than the corresponding normal values, but the values were much less than those of the patient. The results suggested that the patient was homozygote, and his parents and his eldest brother were heterozygotes.

Adult↗
PubMedDate not supplied

Vitiligo with primary hypothyroidism and hypoacusis: a case report.

A 48-year-old female patient with vitiligo developed primary hypothyroidism and hypoacusis. The signs and symptoms of hypothyroidism improved with thyroid hormone replacement therapy but hypoacusis did not. The coexistence of vitiligo and thyroid disease is uncommon and the additional association of hypoacusis is very rare. There may be a common autoimmune pathogenesis for the three disorders. Vitiligo may be a diagnostically useful sign which suggests the presence of multiple autoimmune diseases.

Female↗
PubMedDate not supplied

Primary aldosteronism with cortisol overproduction from bilateral multiple adrenal adenomas.

A 55-year-old woman with bilateral multiple adenomas showed hypertension, muscle weakness, hypokalemia, moon-like face and truncal obesity. Increased serum and urinary levels of aldosterone were observed. Serum cortisol level did not show a normal circadian rhythm. Microscopic examination of the resected tumors showed two types of adenoma cells; one (golden yellow tumor) was a large clear cell with foamy cytoplasm which possibly secreted aldosterone and the other (dark brown tumor) was an acidophilic cell with lipofuscin which might have produced cortisol. This is a very rare case of primary aldosteronism with Cushing's syndrome due to multiple bilateral adrenal adenomas.

Adenoma↗
PubMedDate not supplied

Familial primary pulmonary hypertension--report of two siblings.

Familial primary pulmonary hypertension was found in two siblings (sister and brother). The woman noted exertional dyspnea at the age of 28 yr. The younger brother noticed exertional dyspnea, cough with bloody sputum and pretibial edema at the age of 38 yr. We diagnosed them as primary pulmonary hypertension as based on hemodynamic and histopathological findings. Regardless of the treatment, both patients died of right-sided heart failure with a short time course. We examined their family members, but there were no other members with primary pulmonary hypertension.

Adult↗
PubMedDate not supplied

A novel monoclonal antibody, H9, directed against the core protein of MUC1 mucin.

MUC1 mucin is a target protein for many monoclonal antibodies. Human MUC1 detected by a murine anti-KL-6 monoclonal antibody that recognizes a sialylated carbohydrate chain has been designated KL-6/MUC1. Given the heterogeneous antigenicity of KL-6/MUC1, we established a new murine monoclonal antibody, H9, that reacts with epitope DTRP (Asp-Thr-Arg-Pro) peptides within the immunodominant region of the tandem repeat of MUC1 mucin. The reactivity of the H9 antibody differs from that of other previously reported antibodies that recognize the tandem repeat region of MUC1. Immunohistochemical experiments indicate that the reactivity of the H9 antibody is similar to that of other antibodies directed against MUC1 core proteins. A new cancer-associated protein detected by a sandwich assay using the H9 antibody as a catcher and the KL-6 antibody as a tracer is designated HK9. Serum HK9 levels showed a high expression level in lung cancer: 51% (19/37 cases) for adenocarcinoma, 39% (11/28 cases) for squamous cell carcinoma, and 67% (10/15 cases) for small cell carcinoma. The HK9 expression in lung cancer increased with cancer progression. These findings suggest monoclonal antibody H9 to be a novel antibody that reacts with an epitope within the tandem repeat region of MUC1, and that the cancer-associated antigen HK9 may have useful tumor-associated properties.

Animals↗