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Biomedical subjects

N Hama

Publications and source records attributed to N Hama.

50 records · Page 3Linked to original sources

Rheumatoid arthritis in a patient with pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a rare, inherited disorder of the connective tissue. Possible association of autoimmune thyroiditis and PXE has been suggested, but reports of other autoimmune diseases complicating PXE are rare. We report a case of rheumatoid arthritis (RA) in a patient with PXE. Since the frequency of PXE is likely to be underdiagnosed, further studies to elucidate the true incidence and significance of the association of RA and PXE will be needed.

Adult↗

Characterization of autoantibodies that recognize U4/U6 small ribonucleoprotein particles in serum from a patient with primary Sjögren's syndrome.

We identified autoantibodies that recognize the U4/U6 snRNPs in a serum from a 63-year-old Japanese patient (TT) with primary Sjögren's syndrome. This patient's serum immunoprecipitated U4 and U6 sn-RNAs exclusively from 32P-labeled HeLa cell extracts and a newly identified 120-kDa protein along with the Sm core proteins (B'/B, D, E, F, and G) from [35S] methionine-labeled HeLa cell extracts. Immunoblotting demonstrated that only the 120-kDa protein was recognized by this unique serum. In glycerol density gradient centrifugation, the 120-kDa protein reactive with TT serum cosedimented with U4 and U6 snRNAs, suggesting that the 120-kDa protein is a unique component of the U4/U6 snRNP particle. In the same study, the U4/U6 snRNP precipitated by TT serum sedimented only in the lower density, whereas anti-Sm antibodies precipitated U4/U6 snRNAs in a broad range of the gradient. This result suggests the presence of at least two molecular forms of the U4/U6 snRNP particles; larger particles, probably the U4/U5/U6 snRNP complex, and free particles. Thus, the U4/U6 snRNP recognized by TT serum includes the U4 and U6 snRNAs, with Sm core proteins, and the novel 120-kDa protein, and appears to be a free particle not associated with larger complexes.

Autoantibodies↗

Endothelial production of C-type natriuretic peptide and its marked augmentation by transforming growth factor-beta. Possible existence of "vascular natriuretic peptide system".

C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, is thus far known to be distributed mainly in the central nervous system and is considered to act as a neuropeptide, in contrast to atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which act as cardiac hormones. Recently, we and others have demonstrated that the ANP-B receptor, which is selectively activated by CNP, is localized not only in the central nervous system but in peripheral tissues, including blood vessels. This finding has made us speculate regarding the peripheral production of CNP. In the present study, cultured endothelial cells were examined for CNP production by RIA and Northern blot analysis. CNP-like immunoreactivity was detected in the conditioned media of endothelial cells. Northern blot analysis detected CNPmRNA with a size of 1.2 kb. In addition, transforming growth factor (TGF)-beta, one of the key growth factors for vascular remodeling, markedly stimulated the expression of CNPmRNA and induced a tremendous increase in CNP secretion. We could also detect CNP transcript in the bovine thoracic aorta using the reverse transcription-polymerase chain reaction method. The present study demonstrates the endothelial production of CNP and suggests that a member of the natriuretic peptide family may act as a local regulator in vascular walls. Since evidence for the pathophysiological importance of the vascular renin-angiotensin system has been accumulating and the natriuretic peptide system is known to be antagonistic to the renin-angiotensin system, the possible existence of "vascular natriuretic peptide system" may prove to be of physiological and clinical relevance.

Animals↗

Pharmacokinetics of brain natriuretic peptide in rats.

The pharmacokinetics of rat brain natriuretic peptide (rBNP) was compared with that of alpha-rat atrial natriuretic peptide (alpha-rANP) in rats. After intravenous infusion in rats (600 pmol min-1kg-1 for 2 min), the disappearance of plasma rBNP was 4-fold slower than that of alpha-rANP. The estimated mean plasma clearance rates for rBNP and alpha-rANP were 45.9 ml min-1kg-1 and 74.4 ml min-1kg-1, respectively. The affinity of rBNP for the clearance receptor or degradation enzyme was considered to be lower than that of alpha-rANP.

Animals↗

[A case of Wegener's granulomatosis with necrotizing granuloma limited to intraorbital lesions].

A patient of Wegener's granulomatosis (WG) who developed intraorbital tumor without pulmonary and renal involvement was reported. A 52-year-old male has suffered from visual disturbance and right proptosis. Administration of betamethasone resulted in a temporary relief of his symptoms. However, following the reduction of steroid dosage, severe recurrence of ocular symptom occurred and his right sight was completely lost. On admission to our hospital, there were swollen eyelids and saddle nose. The CT scan demonstrated intraorbital tumors bilaterally associated with chronic sinusitis. The repeated biopsies of nasal mucosal lesions disclosed presence of a giant cell granuloma with necrotizing vasculitis. A diagnosis of WG had been made, so intermittent high-dose intravenous cyclophosphamide therapy were initiated. The size of the bilateral intraorbital tumors reduced with continuous cyclophosphamide therapy. At the last observation during 22 months after the initiation of cytotoxic therapy, there was no evidence of clinical and radiological recurrence. Three cases of WG with intracranial tumors in our hospital showed multiple cranial nerve palsy and poor response to corticosteroid therapy. The "limited form" without renal involvement has been known as a subset of WG with a relatively good prognosis. This report suggest the existence of further limited form with intracranial granuloma as a cardinal presentation of WG. Although the extent of granulomatous lesions are limited and progression is slow, the treatment by corticosteroid alone is not sufficient and as the systems form of WG, combined therapy with cyclophosphamide appeared to be indicated.

Betamethasone↗

[Clinical significance of anti-nucleolar antibodies detected by immunoprecipitation method in patients with systemic sclerosis].

We have characterized a clinical significance of anti-U3RNP, anti-7-2RNP, anti-RNA polymerase I and anti-PM-Scl antibody, autoantibodies to nucleolar proteins detected by immunoprecipitation method in patients with systemic sclerosis (SSc). In 248 patients with SSc, anti-U3RNP antibody was positive in 9 (3.6%), anti-7-2RNP antibody was positive in 7 (2.8%) and anti-RNA polymerase I antibody was positive in 3 (1.2%). But none of 248 patients was positive for anti-PM-Scl antibody. Anti-U3RNP antibody positive SSc patients showed significantly lower frequency of joint and lung involvements, compared with anti-U3RNP antibody negative SSc patients. Anti-7-2RNP antibody was found only in patients with limited scleroderma. The anti-7-2RNP antibody could be detected before appearance of skin thickening, so this indicate the usefulness of detecting anti-7-2RNP antibody in the early stage of SSc. Two of 3 anti-RNA polymerase I antibody positive patients were classified as diffuse scleroderma. All anti-RNA polymerase I antibody positive patients had high incidence of internal organ involvements including lung, heart and kidney, so two of these patients died of heart failure. These data showed the close clinical association of antigenic specificities of anti-nucleolar antibodies analysed by immunoprecipitation method, and indicated the usefulness of detecting these anti-nucleolar antibodies in subgrouping of patients with SSc.

Adult↗

[Spontaneous remission of dermatomyositis which developed one month after normal delivery].

A case of dermatomyositis which developed one month after normal delivery and subsided spontaneously was reported. A 29-year-old woman gave birth to a healthy child. One month later, she noticed muscular pain and weakness of the upper extremities. On admission, there were diffuse edema of upper eyelids with heliotrope rash. The reddish skin rashes were observed on the extensor surfaces of the PIP and MP joints of fingers. Erythrocyte sedimentation rate was 29 mm/hr. The lactic dehydrogenase (LDH), SGOT, CK levels were 470 (normal 150 to 320 IU/l), 43 (normal 6 to 25 IU/l) and 317 (normal 21 to 110 IU/l) respectively. Autoantibodies to nuclear and cytoplasmic antigens were negative. Rheumatoid factor and anti-DNA antibody were negative. Thyroid function was normal. An electromyogram (EMG) demonstrated small amplitude short-duration polyphasic motor unit potentials. The muscle biopsy specimen from left upper arm showed degenerating muscle fibers and infiltration of inflammatory cells surrounding blood vessels. The skin biopsy revealed the presence of edema and perivascular infiltration of lymphocytes. Based on these clinical features and results of various diagnostic tests, a diagnosis of dermatomyositis was established. After the admission, muscle strength has improved dramatically and the CK returned to normal level without specific drug therapy. She has since been seen as an out patient, and complete remission lasted for two years up to date. Review of the literature disclosed that 13 cases of PM/DM which developed during pregnancy or postpartum have been reported including the present case. Detailed analysis showed that these patients were characterized by mild muscular diseases, rare occurrence of internal organ involvements and good response to steroid therapy. As our case, a spontaneous remission was also observed. Although the mechanism involved in occurrence of inflammatory myositis associated with pregnancy or delivery are not clarified, these patient indicated a presence of subset of PM/DM which do not require intensive drug therapy.

Adult↗

C-type natriuretic peptide (CNP) in rats and humans.

We have established a specific radioimmunoassay (RIA) for C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, and have elucidated its tissue distribution and molecular form. In rats, high concentrations of CNP-like immunoreactivity (-LI) were detected in the anterior lobe (19.8 +/- 8.6 pmol/g) and neurointermediate lobe (4.64 +/- 0.74 pmol/g) of the pituitary gland. CNP-LI was present throughout the brain with its high concentrations in the hypothalamus and cerebellum. Small amounts of CNP-LI were also detected in the lower part of gastrointestinal tract and the kidney. However, no significant amount of CNP-LI was present in other organs including the heart. Considerable amounts of CNP-LI were detected throughout the human brain. High performance-gel permeation chromatography coupled with the RIA detected two peaks of CNP-LI in the rat brain; CNP and presumably its N-terminally elongated form with 53 amino-acid residues, CNP-53. These findings indicate that the tissue distribution and processing pattern of CNP are clearly different from those of atrial natriuretic peptide and brain natriuretic peptide and suggest possible roles of CNP as a neurotransmitter or neuromodulator rather than as a cardiac hormone.

Animals↗

Isolation and characterization of cDNA encoding the 80-kDa subunit protein of the human autoantigen Ku (p70/p80) recognized by autoantibodies from patients with scleroderma-polymyositis overlap syndrome.

Anti-Ku (p70/p80) autoantibodies in patients with scleroderma-polymyositis overlap syndrome recognize a 70-kDa/80-kDa protein heterodimer which binds to terminal regions of double-stranded DNA. In the present study, we isolated full-length cDNAs that encode the 80-kDa Ku subunit. Initial screening of a human spleen cDNA library with anti-Ku antibodies yielded a cDNA of 1.0 kilobase (kb) (termed K71) encoding a portion of the 80-kDa Ku polypeptide (identification based on immunological criteria). In RNA blots, this cDNA hybridized with two mRNAs of 3.4 and 2.6 kb. In rescreening of a cDNA library constructed from simian virus 40-transformed human fibroblast mRNA with the K71 cDNA as a hybridization probe, three positive clones were isolated, and that bearing the longest insert (termed Ku80-6) was selected for further characterization. In vitro transcription and translation experiments produced an immunoprecipitable polypeptide which comigrated with the 80-kDa Ku subunit. The Ku80-6 cDNA proved to be 3304 nucleotides in length, with an additional poly(A) tail, closely approximating the size of the larger mRNA. It contains a single long open reading frame encoding 732 amino acids (Mr = 82,713). The putative polypeptide has a high content of acidic amino acids and a region with periodic repeat of leucine in every seventh position which may form the "leucine zipper" structure. In genomic DNA blots, probes derived from the opposite ends of cDNA Ku80-6 hybridized with several nonoverlapping restriction fragments from human leukocyte DNA, indicating that the gene encoding the 80-kDa Ku polypeptide is divided into several exons by intervening sequences.

Amino Acid Sequence↗

Pyloric stenosis in a patient with progressive systemic sclerosis.

A 64-year-old Japanese woman with progressive systemic sclerosis (PSS) who developed severe pyloric stenosis is described. The conservative treatments brought only the temporary symptomatic relief, and pyloroplasty became necessary. No ulcerative lesions or tumors were found in the resected stomach or duodenum specimens implicated for stenosis. The histological examinations revealed edema and replacement fibrosis in the pyloric ring. The possible mechanisms of pyloric stenosis are discussed.

Female↗

Strategy and the art of reinventing value.

In "From Value Chain to Value Constellation: Designing Interactive Strategy" (July-August 1993), Richard Normann and Rafael Ramírez argue that successful companies increasingly do not just add value, they reinvent it. The key strategic task is to reconfigure roles and relationships among a constellation of actors--suppliers, business partners, customers--in order to mobilize the creation of value in new forms and by new players. What is so different about this new logic of value? It breaks down the distinction between products and services and combines them into activity-based "offerings" from which customers can create value for themselves. But as potential offerings become more complex, so do the relationships necessary to create them. As a result, a company's strategic task becomes the reconfiguration and integration of its compentencies and customers. Normann and Ramírez provide three illustrations of these new rules of strategy. IKEA has blossomed into the world's largest retailer of home furnishings by redefining the relationships and organizational pratices of the furniture business. Danish pharmacies and their national organization have used the opportunity of health care reform to reconfigure their relationships with customers, doctors, hospitals, drug manufacturers, and with Danish and international health organizations.(ABSTRACT TRUNCATED AT 250 WORDS)

Consumer Behavior↗