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M Yazawa

Publications and source records attributed to M Yazawa.

At least 55 records · Page 3Linked to original sources
PubMed1996

Solution X-ray scattering data show structural differences between yeast and vertebrate calmodulin: implications for structure/function.

We present here the first evidence, obtained by the use of solution X-ray scattering, of the solution structure of yeast calmodulin, a poor activator of vertebrate enzymes. The radius of gyration of yeast calmodulin decreased from 21.1 to 19.9 angstroms when excess Ca2+ ions were added. The profiles of the pair-distribution function suggested that yeast calmodulin without Ca2+ has a dumbbell-like shape which changes toward a rather asymmetric globular shape, from its dumbbell shape, by the binding of Ca2+. In the presence of a calmodulin binding peptide such as MLCK-22 (a synthetic peptide corresponding to residues 577-598 of skeletal myosin light chain kinase), the radius of gyration of yeast calmodulin decreased by 1.6 angstroms, and the molecular shape of it estimated from the profile of the pair-distribution function was globular but less compact than that of vertebrate calmodulin. These results for the structure of yeast calmodulin complexed with Ca2+ and with Ca(2+)-peptides are quite different from those of vertebrate calmodulin. Thus, the functional differences between yeast and vertebrate calmodulin which we reported previously [Matsuura, I., et al. (1993) J. Biol. Chem. 268, 13267-13273] have been interpreted on the basis of the structural differences between them. Moreover, the structural studies on chimeric proteins of chicken and yeast calmodulin suggest that Ca2+ binding at site IV is essential to form the full active dumbbell structure, which is characteristic of vertebrate-type calmodulin.

Amino Acid Sequence↗
PubMed1996

Secondary structure and Ca(2+)-binding property of the N-terminal half domain of calmodulin from yeast Saccharomyces cerevisiae as studied by NMR.

Using two- and three-dimensional NMR techniques, 1H and main-chain 15N resonances of the N-terminal half domain of yeast calmodulin (YCM0-N) in the presence of Mg2+ and Ca2+ (Mg(2+)-and Ca(2+)-forms) were assigned. The secondary structures of YCM0-N in both forms were determined. The NOESY and 15N-edited NOESY spectra of YCM0-N in each form indicate that there is a hydrophobic core and that two Ca(2+)-binding loops are connected by a short antiparallel beta-sheet. There are four helices (A, B, C, and D named from the N-terminus) for YCM0-N in the Mg(2+)-form. The B-helix is, however, not formed in the Ca(2+)-form. The Ca(2+)-binding of YCM0-N was monitored by (1H,15N)-HSQC at various Ca2+ concentrations. The observed spectral changes as a function of Ca(2+)-concentration can not readily be grouped into a small number of classes; each residue shows individual spectral change. There is no apparent relationship between the spectral change and the type or location of the amino acid concerned.

Amino Acid Sequence↗
PubMed1996

Acute pandysautonomia: mass spectrometric and histopathological studies of the sympathetic nervous system during long term L-threo-3,4-dihydroxyphenylserine treatment.

Stable isotope labelled L-threo-3,4-dihydroxyphenylserine (L-DOPS) infusion tests and histopathological studies of the rectal autonomic nerves were performed in a patient with acute pandysautonomia. A pronounced increase in blood pressure occurred and stable isotope labelled noradrenaline appeared in the plasma during L-DOPS infusion in the acute stage, but decreased during the next three years. Noradrenergic nerve fibres in the rectal mucosa showed no recovery, and so clinical improvement had occurred without apparent significant regeneration of the peripheral autonomic nerves.

Acute Disease↗
PubMed1996

[Open heart surgery in patients with systemic diseases requiring steroid treatment].

Our surgical experiences in 9 patients who required steroid treatment for systemic diseases before, during and after the open heart surgery were reviewed. Subjects included 3 patients with systemic lupus erythematodes, 3 with aortitis syndrome, 1 with Behçet disease and 1 with rheumatoid arthritis. Cardiovascular lesion was aortic valve regurgitation in 2, Stanford A aortic dissection in 1 and ischemic heart disease in 3 patients. Duration of morbidity for systemic diseases before the surgery ranged between 0 nd 102 months, with a mean of 36 months. Steroid treatment was continued for 4 to 216 months (mean 70+/-76 months) before the surgery at a dose of 5-40 mg per day for conversion into prednisolone. In principal, methylprednisolone was given during the surgery, and the prednisolone was given at a dose of 20-140 mg per day on the day of operation or on the first postoperative day. Surgical procedures included a aortic valve prosthesis with Dacron cloth skirt implantation in 1 patient, surgical angioplasty of the left main coronary ostium in 1 and internal thoracic arteries grafting in 2 patients. Hospital mortality was 1 patient due to low cardiac output syndrome. Acute renal failure occurred in 2 patients with systemic lupus erythematodes, and wound complication was observed in 2 patients. In our experience, appropriate treatment for systemic diseases, timing of surgery and continuation of steroid treatment at an appropriate dose during and after the surgery seemed very important such as surgical procedure in order to prevent postoperative complications such as periprosthetic leakage and failure of anastomosis.

Aortic Arch Syndromes↗
PubMed1995

Immunohistochemical localization of the calcium/calmodulin-dependent protein phosphatase, calcineurin, in the mouse testis: its unique accumulation in spermatid nuclei.

Immunohistochemical localization of a calmodulin-dependent protein phosphatase, calcineurin, was studied in the mouse testis in relation to previous observations showing that calmodulin is unusually rich in spermatogenic stages from mid-pachytene spermatocytes to elongating spermatids. The antibodies raised against calcineurin from scallop testis reacted with subunit B, but not subunit A, of calcineurin isoforms from mouse brain and testis. Indirect immunofluorescence using these antibodies on the mouse testis revealed positive reactions only in the nuclei of round or elongating spermatids: calcineurin started to accumulate in nuclei from the acrosomal cap phase, peaked at the initial stage of nuclear elongation, and decreased thereafter. There was almost no signal in the cytoplasm; spermatogenic cells at other stages, including spermatogonia, spermatocytes, mature sperm, and other somatic cells in the seminiferous tubules were totally negative. Immuno-electron microscopy gave the same result, on the basis of measuring the density of immunogold particles. These results suggest a role for calcineurin in remodeling of the nuclear chromatin in metamorphosing spermatids.

Animals↗
PubMed1995

Evidence for involvement of a 12-residue peptide segment of the heavy chain in the neck region of smooth muscle myosin in formation of the 10S conformation.

Two synthetic peptides having amino acid sequences of the heavy chain segments in the neck region of porcine aorta smooth muscle myosin were used to study the formation of the 10S folded conformation. These peptides, MHC821-835 and MHC835-846, correspond to residues 821-835 and 835-846, respectively, of the chicken gizzard myosin heavy chain. The effects of these peptides on the filament formation of porcine aorta smooth muscle myosin were examined. The filamentous myosin fraction increased on the addition of MHC835-846 at NaCl concentrations lower than 0.25 M for both dephosphorylated and phosphorylated myosin, while the filament formation of dephosphorylated myosin was unaffected by the addition of MHC821-835 up to 30 microM. The filaments formed in the presence of MHC835-846 were observed by electron microscopy to be morphologically indistinguishable from those formed in the absence of the peptide. Rotary shadowed images of dephosphorylated myosin monomers revealed mostly the 10S form in the absence of MHC835-846, while the 6S form was predominant in the presence of the peptide. The results indicate that MHC835-846 inhibits the formation of the 10S conformation. On cosedimentation assaying with myosin, rod and light meromyosin, MHC835-846 bound to each of them with a stoichiometry of nearly 1 mol/mol heavy chain. Altogether, these results suggest that the region in the myosin heavy chain corresponding to MHC835-846 may be involved in the binding site for the light meromyosin portion of myosin for formation of the 10S conformation.

Amino Acid Sequence↗
PubMed1995

[A case of primary intracranial malignant lymphoma showing a spontaneous regression].

An eighty-year-old woman, who had been admitted with disorientation and gait disturbance, was revealed to have multiple intracranial tumors in the right temporal lobe and cerebellar vermis on CT and MRI. Following intravenous injection of dexamethasone (8 mg/day) for three days, isosorbide (90ml/day) was given in order to decrease brain edema, and the tumors increased in size rapidly in the next four months. However, most of the lesions disappeared or became markedly small without any specific therapy three months after the exacerbation of the disease. The brain tumors recurred one year thereafter, and the pathological diagnosis of primary intracranial malignant lymphoma, diffuse large B-cell type was done by autopsy examination. This patient was considered to have shown a spontaneous regression during the clinical course, and the clinicopathological descriptions of the case are presumed to present characteristic features of primary, intracranial malignant lymphoma.

Aged↗
PubMed1994

Infrared studies of interaction between metal ions and Ca(2+)-binding proteins. Marker bands for identifying the types of coordination of the side-chain COO- groups to metal ions in pike parvalbumin (pI = 4.10).

Metal-ligand interactions in the Ca(2+)-binding sites of pike parvalbumin (pI = 4.10) have been examined by Fourier-transform infrared spectroscopy. The region of the COO- antisymmetric stretch provides useful information on the types of coordination of the COO- groups to the metal ions in the Mg(2+)-, Mn(2+)-, and Ca(2+)-bound forms. In the spectrum of the Ca(2+)-bound form, two bands are observed at 1,582 and 1,553 cm-1, whereas, in the spectra of the Mg(2+)- and Mn(2+)-bound forms, bands are observed only in the region around 1,582 cm-1 and no band is found in the region around 1,553 cm-1. The 1,553-cm-1 band of the Ca(2+)-bound form reflects the bidentate coordination of the COO- groups of both Glu-62 in the CD site and Glu-101 in the EF site to the Ca2+ ions, which has been made clear by X-ray analysis as a feature of the Ca(2+)-bound form. Absence of such a band in the spectrum of the Mn(2+)-bound form is consistent with the X-ray structure of this form where both of the two COO- groups are unidentate. These unidentate COO- groups of Glu-62 and Glu-101 in the Mn(2+)-bound form seem to give rise to a band at 1,577-1,574 cm-1. The spectrum of the Mg(2+)-bound form is also consistent with the 'pseudo-bridging' coordination of the COO- group of Glu-101 reported in the X-ray structure of a form where the Mg2+ ion occupies only the EF site, and the same spectrum is further indicative of the 'pseudo-bridging' coordination of the COO- group of Glu-62.

Animals↗
PubMed1994

Fever of unknown origin: a review of 80 patients from the Shin'etsu area of Japan from 1986-1992.

In this survey involving 10 hospitals, we analyzed data on 80 Japanese patients from the Shin'etsu area (Nagano-ken and Niigata-ken) who were observed for fever of unknown origin (FUO). Our objectives were to identify the underlying causes and the relevant diagnostic methods. Fourteen of the patients died of the underlying illness. The cause of the FUO was infection in 43 patients, allergic or autoimmune disease in 13, neoplasm in 7, miscellaneous causes in 3, and undetermined in 14. FUO was self-limited in 13 patients and persistent in one patient. Methods successfully used to establish the final diagnosis in 66 patients were: evaluation of the clinical course or response to treatment in 16, serologic tests in 12, bacteriologic studies in 10, biopsy in 9, cytologic examination in 6, conventional radiology in 6, necropsy in 3, endoscopy in 2, and biochemical testing in 2.

Adolescent↗
PubMed1994

[A case of mediastinal cystic lymphangioma in childhood].

We report a case of lymphangioma, which was widely extended from anterior to posterior mediastinum. The patient was an asymptomatic six-year-old male with a right upper mediastinal mass on chest roentgenograms. Computed tomogram showed a large anterior mediastinal mass, which extended to upper and posterior mediastinum, involving thymus, superior vena cava and innominate vein. Through midline sternotomy, the tumor was visualized and was invading the thymus, bilateral phrenic nerves, SVC and innominate veins. The tumor was also found to extend to the right side of the trachea and vertebra along the azygos vein. The tumor was resected successfully with the preservation of bilateral phrenic nerves. Macro-and microscopic examination revealed polycystic tumor with endothelialized inner spaces. Some cysts contained smooth muscle in their walls. Supportive structures contained variable amounts of fat and connective tissue. The patient weaned from mechanical respiratory support on the first post-operative day, although his diaphragms elevated slightly with poor movement. Phrenic nerve palsy was suspected, but the position and the movement of diaphragms improved four months after the operation. The patient has been well and free from tumor recurrence for four years since the operation.

Child↗
PubMed1993

Mutagenesis of the fourth calcium-binding domain of yeast calmodulin.

The fourth calcium-binding domain (domain IV) of the yeast (Saccharomyces cerevisiae) calmodulin is unable to bind Ca2+ (Matsuura, I., Ishihara, K., Nakai, Y., Yazawa, M., Toda, H., and Yagi, K. (1991) J. Biochem. (Tokyo) 109, 190-197). The functional significance of Ca2+ binding to domain IV was investigated by site-directed mutagenesis or recombinant DNA techniques. A recognition site for the restriction enzyme ClaI was introduced at the homologous position of Ile130 in the nucleotide sequence of chicken and yeast calmodulin cDNA, and chimeric proteins of the yeast and the vertebrate calmodulin were prepared. One of the resulting mutants named C4Y consisted of Ala1-Ile130 of chicken calmodulin and Asp131-Lys148 of yeast calmodulin. The mutant C4Y showed the yeast-type feature, and its enzyme activation profiles were similar to those of yeast calmodulin. A single substitution of Glu for Gln140 was carried out in the mutant C4Y. The resulting mutant (C4Y140E) bound 4 mol of Ca2+ and showed the vertebrate-type enzyme activation. Therefore, the alterations of 3 residues in the Ca(2+)-binding loop of the yeast-type domain IV, Ser129-->Asp, insertion of Ile130, and Gln140-->Glu, were enough for the recovery of Ca2+ binding and enzyme activation. Ca2+ binding to domain IV may induce the active conformation of the C-terminal half-molecular domain.

Amino Acid Sequence↗
PubMed1993

Mg2+ inhibits formation of 4Ca(2+)-calmodulin-enzyme complex at lower Ca2+ concentration. 1H and 113Cd NMR studies.

Our previous 1H NMR studies indicated that when mastoparan (MP) is added to Ca(2+)-half-saturated calmodulin (2Ca(2+)-CaM) in the absence of Mg2+ ions, Ca2+ ions transfer from the C-terminal-half domain of CaM not interacting with MP to the N-terminal-half domain of CaM interacting with MP at lower MP concentrations (Ohki, S., Yazawa, M., Yagi, K., and Hikichi, K. (1991b) J. Biochem. (Tokyo) 110, 737-742). As a consequence, the active form of 4Ca(2+)-CaM.MP complex is formed. In the present study, we studied the effect of Mg2+ ions on Ca2+ transfer. In the presence of Mg2+ ions, such Ca2+ transfer does not occur. The effects of Mg2+ ions are also studied by observing 113Cd NMR in the presence of M13, the 26-residue peptide of the CaM-binding region of myosin light chain kinase. The 113Cd NMR results show that Mg2+ ions prevent to form the active complex. Mg2+ plays an important role as an inactivating factor to CaM.

Amino Acid Sequence↗
PubMed1993

[Delayed surgical treatment of traumatic injury of the thoracic aorta].

A 55-year-old male, who had fallen down from a tree, was brought into the emergency room. The initial roentogenogram of the chest showed widening of the mediastinum, but CT study did not give the blood leaking out of the aorta. Thus the patient was managed in ICU. An aortography showed an aneurysmal dilatation of the descending aorta on ninth day after the injury, but we interpreted it may not proceed to the free rupture. Therefore we postponed the operation of the aortic injury until 41 days after the trauma. Immediate repair may be thought to be the first choice for acute traumatic injury of the thoracic aorta, but delayed surgery can be achieved safely on selective patients.

Aorta, Thoracic↗
PubMed1993

[Solitary papilloma of the lung: a case report].

A case of solitary papilloma of pulmonary parenchyma is presented. The patient was a 47-year-old woman admitted our clinic because of a mass shadow on routine chest films. The operation was performed without definitive diagnosis of the tumor. Intraoperative frozen specimen revealed to be either papilloma or squamous cell carcinoma. So right upper and middle lobectomies with mediastinal lymph nodes dissection were performed. When a definite diagnosis cannot be proved to be papilloma even at surgery, treatment as a lung cancer should be performed. Solitary benign papilloma like this case is very rare. According to the literature, this case seems to be the first Japanese case of solitary papilloma in pulmonary parenchyma.

Diagnosis, Differential↗
PubMed1993

[Leiomyosarcoma of the chest wall].

An unusual case of a primary leiomyosarcoma of the chest wall is presented. The patient was a 41-year-old man and had no symptoms. The chest x-ray showed a tumor with mediastinal involvement. A percutaneous needle biopsy indicated that it was histologically a leiomyosarcoma. Wide en bloc excision of the chest wall was done, including much of the third, fourth and fifth ribs and a piece of lung. The defect was closed with GORE-TEX soft tissue patch. There were three courses of chemotherapy added, but the patient had a local recurrence, which was resected again, two years after the first surgery. It may be thought that wide en bloc excision and closely follow-up are important in the management of a leiomyosarcoma of the chest wall because of its high recurrence rate.

Adult↗