Search PubMed⌕ Search

Biomedical subjects

M Yasuda

Publications and source records attributed to M Yasuda.

At least 343 records · Page 19Linked to original sources
PubMed1993

Time-course of vertebral and femoral bone loss in rats administered gonadotrophin-releasing hormone agonist.

This study was carried out (1) to compare the time-course of the change in bone metabolism in rats administered gonadotrophin-releasing hormone agonist (GnRHa) and bilaterally ovariectomized (OVX) rats and (2) to investigate the changes in bone metabolism after discontinuance of GnRHa. Seventy female Sprague-Dawley rats, aged 90 days, were divided into four groups. Group 1 underwent a sham operation, group 2 was surgically ovariectomized and group 3 was given a GnRHa (leuprorelin acetate for depot suspension) s.c. injection every 30 days. Group 3 was further divided into three subgroups: rats were administered GnRHa for 12 months (GnRHa 12M), 6 months (GnRHa 6M) or 3 months (GnRHa 3M). Group 4 served as a basal control. The bone mineral density (BMD) of lumbar vertebrae and femoral bone, measured by dual-energy X-ray absorptiometry, and the serum bone metabolic parameters were determined every 45-90 days. The bone histomorphometry of lumbar vertebra was measured on days 180 and 360 after surgery. GnRHa 12M rats showed significantly lower BMD of vertebrae and femoral bone, lower bone volume and higher bone turnover compared with sham-operated rats and those with secondary hyperparathyroidism on days 180 and 360. Their time-course for changes in bone metabolism was almost the same as that of OVX rats. GnRHa-discontinued rats showed a recovery of bone turnover. The recovery of BMD in GnRHa 6M rats was smaller than that of GnRHa 3M rats after GnRHa discontinuance. The bone volume for GnRHa 6M rats was significantly lower than that for GnRHa 3M on day 360.

Absorptiometry, Photon↗
PubMed1993

Mixed connective tissue disease presenting myasthenia gravis.

We herein describe a 41-year-old female patient with an association of myasthenia gravis (MG) with anti-acetylcholine receptor (AcR) antibody, mixed connective tissue disease (MCTD) and Sjögren's syndrome (SjS). We reviewed the reported association of MG and MCTD, systemic lupus erythematosus, progressive systemic sclerosis, polymyositis and dermatomyositis, and SjS. Since we could find only two patients who fulfilled the diagnostic criteria for MCTD in the previous literature, we concluded that the association of MG and MCTD is rare. We also discuss the coexistence of SjS as one of the underlying pathological conditions for the association of MG and various connective tissue diseases including MCTD.

Adult↗
PubMed1993

Fine structural aspects of the anterior necrotic zone in the leg bud of the chick embryo.

A fine structural study was undertaken on the area called the anterior necrotic zone of leg buds of the chick embryo at stages 22-29. Physiologically dying cells, which were distributed in the mesenchymal area, were characterized by increased electron density of the cytoplasm, appearance of electron lucent vacuoles and condensed chromatin pattern. Many of the dying cells seemed to be fragmented into several pieces of cell debris during the necrotic process. Two kinds of cells were observed to take up the necrotic cells; one type, large cells 15 microns or more in size and irregular in shape, which had lysosomes, extended microvillus-like cytoplasmic projections and pseudopods, took up pieces of necrotic cells by phagocytosis and stored them in acid phosphate-negative and -positive vacuoles. The other type was several microns in diameter with numerous free ribosomes and stored a small number of vacuoles containing cell debris. At stage 29, profiles of necrotic cells lying free in the mesenchymal area, and cells containing one or two vacuoles filled with cell debris decreased in number as well as large cells containing numerous vacuoles, whose contents seemed to be degraded. When pieces of the anterior portion of chick leg buds at stage 24 were organ-cultured for 3 days after glutaraldehyde-fixed mouse red blood cells were injected, the red blood cells were taken up into cells in the mesenchymal area. Formation of large cells containing numerous vacuoles stuffed with red blood cells was rare. These findings may imply that most necrotic cells in the anterior necrotic zone are disposed of by macrophages and that some are endocytosed by mesenchymal cells.

Acid Phosphatase↗
PubMed1993

[A simple renal cyst].

Incidence of simple renal cysts was calculated in 30,316 patients receiving routine ultrasound examination in one hospital, and 170 cases visiting Chiba University Hospital were further analyzed in terms of their clinical features. Incidence of simple renal cyst was 14% in all populations and ratio of male to female was 1.6:1. Patients age ranged from 8 to 92 years (average age 58.6 years) and number of a renal cyst was increased after fifth decade in both sexes. Patients of Chiba University Hospital were examined on symptoms and clinical courses with maximal follow up to 132 months (average 18 months). Symptoms associated with simple renal cysts were: none (75.3%) pain (14.7%) and gross hematuria (6.4%). Urinalysis of patients without associated urinary diseases, showed microhematuria in 40% and proteinuria in 12%, however, grade of microhematuria and proteinuria was not correlated with size of cysts. Number of cysts tended to increase with age. Size of cysts and rate of enlargement were increasing along with age. In any cases, renal function was not and affected nor occurred malignant tumor during follow-up period. Cyst punctures with sclerosing agent were performed in 16 patients, and most of the cysts remained the same as or exceeded their original size. It is concluded that routine follow-up is sufficient in most cases without symptoms, since simple renal cysts increase slowly, and impairment of renal function and progression to malignant tumors do not occur.

Adolescent↗
PubMed1993

[Renal functions of the patients with long-term catheterization in upper urinary tract].

In order to investigate long-term effects of indwelling urinary catheters on renal functions, in 46 patients (27 male and 19 female) with ureterostomy or nephrostomy serum creatinine values were measured periodically. Average age of the patients was 60.6 years old. Duration of catheterization was more than 3 years (average 8.1 years). Renal dysfunction was defined as an elevation of serum creatinine more than 2 mg/dl. It was found that catheterization used more than 15 years evoked renal insufficiency over 50% of such patients. This period, however, was shorten to 11 years in patients with nephrolithiasis or frequent fever. It was concluded that urolithiasis and symptomatic urinary tract infections were two remarkable risk factors for the deterioration of renal functions, and that these risk factors must be avoided in patients on long-term catheterization in the upper urinary tract.

Aged↗
PubMed1993

In vitro IgM rheumatoid factor production by peripheral blood mononuclear cells from patients with seronegative rheumatoid arthritis.

OBJECTIVE: We investigated whether mononuclear cells (MNC) from patients with seronegative rheumatoid arthritis (SNRA) are able to produce rheumatoid factor (RF) in response to lectin stimulation, Staphylococcus aureus Cowan I (SAC) or pokeweed mitogen (PWM), and also we investigated the role of CD5+ B cells in the pathogenesis of in vitro IgM RF production. METHODS: IgM RF production was measured by enzyme linked immunosorbent assay and CD5+ B cells by flow cytometry. Also, the effects of monocyte depletion and the inhibition of prostaglandin (PG) were compared in SNRA, seropositive RA (SPRA) and healthy controls. RESULTS: Peripheral blood MNC of patients with SNRA were able to produce the same amount of IgM RF as patients with SPRA following stimulation and SAC. CD5+ B cells also increased in patients with SNRA as well as patients with SPRA compared to healthy controls. However, a definite contribution of the CD5+ B cells to SAC-induced IgM RF production could not be demonstrated. The role of macrophage and PG on in vitro IgM RF synthesis were insignificant. CONCLUSION: MNC of patients with SNRA were able to produce IgM and IgG RF in response to SAC stimulation as well as that of the healthy controls. However, we could not find a significant role of CD5+ B cells and monocytes on in vitro IgM RF synthesis by MNC of patients with SNRA.

Adult↗
PubMed1993

Comparison of clinical effects of bucillamine between additive combination and single administration study in rheumatoid arthritis.

In a multicentre double blind study, it was demonstrated that bucillamine (Bu) 100 mg was more effective than placebo in patients with rheumatoid arthritis who are partially remitted by gold injections for more than six months. Global effectiveness and usefulness rates of 100 mg Bu in the combination therapy were almost the same as those of 3200 mg Bu in single administration. Side effects were also similar in the two regimens.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1993

Mixed connective tissue disease associated with lupus lymphadenitis.

We have encountered 2 patients with mixed connective tissue disease (MCTD) associated with lymphadenopathy at the outset. Biopsy specimens of enlarged lymph nodes showed massive necrotizing lesions with follicular hyperplasia, which are occasionally observed in the involved lymph nodes of patients with systemic lupus erythematosus (SLE) and called lupus lymphadenitis. Usually, the only histologic finding of an involved lymph node in MCTD is lymphoid hyperplasia. These are the 2nd and 3rd cases of MCTD associated with lupus lymphadenitis. Our cases suggest that histologic studies of the swollen lymph nodes are not helpful in distinguishing MCTD from SLE.

Biopsy↗
PubMed1992

Role of vitronectin in embryonic rat endocardial cell migration in vitro.

Vitronectin is one of the extracellular matrices that mediate cell spreading and attachment in vitro. In the present paper, we demonstrate the involvement of vitronectin in the migration of cushion mesenchymal cells of the embryonic rat heart. Immunohistochemistry established the localization of vitronectin in the myocardial cells and in some of the cushion mesenchymal cells of the truncus arteriosus and atrioventricular canal. In vitro, vitronectin, fibronectin, and collagen type-I revealed significant stimulating activity for cushion mesenchymal cell migration. The distance migrated by cushion mesenchymal cells cultured on vitronectin, collagen type-I, or both vitronectin and fibronectin was similar, but that on fibronectin was significantly shorter. Following the addition of anti-vitronectin IgG to the medium, the migration distance of cushion mesenchymal cells on fibronectin was remarkably increased. Most explants on vitronectin or on both vitronectin and fibronectin became detached from dishes after the addition of the antivitronectin antibody. Immunostaining revealed that cushion mesenchymal cells cultured on substrata other than vitronectin synthesized vitronectin. From these results, it is suggested that vitronectin is synthesized by myocardial cells and some cushion mesenchymal cells, and that vitronectin inhibits cell movement on fibronectin. This feature of vitronectin may be important in the regulation of the migration of cushion mesenchymal cell in vivo.

Animals↗
PubMed1992

Suppressive effects of E3330, a novel quinone derivative, on tumor necrosis factor-alpha generation from monocytes and macrophages.

E3330 [(2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonyl-2- propenoic acid], a novel synthesized hepatoprotective compound, has suppressive effects on tumor necrosis factor-alpha (TNF-alpha) generation from monocytes/macrophages in vitro. E3330 (1-100 microM) reduced lipopolysaccharide (LPS, 10 mg/ml or 1 microgram/ml)-induced TNF-alpha generation from rat resident and Propionibacterium acnes (P. acnes)-elicited peritoneal macrophages, rat and human monocytes, rat Kupffer cells, and splenic mononuclear cells in a concentration-dependent manner. E3330 also (1-100 microM) suppressed TNF-alpha generation stimulated with egg-albumin immune complex in rat P. acnes-elicited peritoneal macrophages. Northern blot analysis showed that LPS-induced expression of TNF-alpha messenger RNA (mRNA) in human blood monocytes was suppressed by E3330. These findings indicate that E3330 has a suppressive effect on TNF-alpha generation from monocytes/macrophages, regardless of origin or species, and this effect is based in part on the suppression of TNF-alpha mRNA expression.

Animals↗
PubMed1992

Intracellular signal transduction in proliferation of synovial cells.

We investigated some steps in the signal transduction pathway leading to the proliferation of synovial cells. 12-o-tetradecanoyl phorbol-13-acetate (TPA) which is known to stimulate phospholipid- and Ca(2+)-dependent protein kinase (C-kinase) enhanced the proliferation of synovial cells. The proliferation of synovial cells induced by interleukin-1 beta. Tumour necrosis factor alpha and granulocytes/macrophages colony stimulating factor, was inhibited by a potent C-kinase inhibitor, H7. These findings strongly suggested that the signal transduction pathway leading to proliferation of synovial cells is transmitted via C-kinase activation. Prostaglandin E2, which is known to stimulate adenylate cyclase, leading to the elevation of intracellular c-AMP level, inhibited the proliferation of synovial cells. This effect could also be mimicked by the addition of a cell permeable c-AMP analog, dibutyryl c-AMP or theophylline. Studies suggest that the feedback signal for proliferation of synovial cells was transmitted through c-AMP. We therefore conclude that signals for stimulation and inhibition of synovial cell proliferation are transmitted through different pathways.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

VDD pacing with a previously implanted single lead system.

Three patients who had undergone implantation of a rate modulated, atrial sensitive RS4 pacemaker, with a single orthogonal lead underwent replacement of a depleted unit with a DDD pulse generator, reusing the original lead with an adapter that allowed conversion of the bipolar atrial electrode into unipolar configuration. The mean atrial electrogram amplitude was 1.8 mV and no significant atrial sensing defects were found during Holter monitoring. As the RS4 pulse generator is no longer available, continued VDD pacing is possible by replacing it with a DDD pulse generator using the previously implanted single lead system.

Aged↗
PubMed1992

Clinical significance of QRS duration during ventricular pacing.

To clarify the clinical significance of an abnormally prolonged paced QRS duration, we studied 114 patients who had undergone pacing for atrioventricular block (AVB). Patients were divided into two groups: group I consisted of 29 patients with at least one paced QRS duration greater than or equal to 180 msec during the follow-up period; group II consisted of 85 patients with paced QRS durations less than 180 msec. The clinical background, QRS complexes before pacing, and the echocardiographic findings were assessed. Males (P less than 0.05), those with H-V block (P less than 0.05) and a wider QRS complex of conducted and escape beats (both P less than 0.01) were dominant in group I. The incidence of underlying heart disease was greater in group I than in group II (83% vs 32%, P less than 0.01). Reduced left ventricular ejection fraction (LVEF) and increased left ventricular end-diastolic dimension (LVDd) were more prominent in group I than in group II (LVEF 0.49 +/- 0.17 vs 0.68 +/- 0.10, P less than 0.01, LVDd 57.1 +/- 7.9 mm vs 48.5 +/- 5.6 mm, P less than 0.01). The paced QRS duration correlated with LVEF (r = -0.61) and LVDd (r = 0.81). A paced QRS duration greater than or equal to 180 msec was sensitive and specific for a LVEF less than 0.5 (83.3% and 85.2%) and LVDd greater than or equal to 60 mm (100% and 81.4%). We conclude that patients with a prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function.

Cardiac Pacing, Artificial↗
PubMed1992

Significant compatibility does not exist at the HLA-DQB gene locus in couples with unexplained recurrent abortions.

The polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) method was used for both examining compatibility at the HLA-DQB1 gene locus and determining HLA-DQ antigen polymorphism in spouses of unexplained recurrent abortions. Genomic DNA samples were prepared from peripheral mononuclear cells from patient and control couples. Two hundred and thirty base pair fragments of the second exon of the HLA-DQB genes were selectively amplified. Amplified DNAs were digested with the restriction endonucleases, Fok I, Hae III, Hha I, Rsa I and Sau3A I, and subjected to electrophoresis in a polyacrylamide gel. The RFLPs showed that habitual aborters and their husbands had neither significantly frequent alleles nor shared common alleles at the HLA-DQB locus when compared to the control group. Since significant HLA-DQB compatibility was not observed between the spouses and unexplained recurrent aborters, in order to determine whether or not HLA compatibility is responsible for the genesis of unexplained recurrent abortions, it is imperative to further examine the compatibility between other HLA gene loci.

Abortion, Habitual↗
PubMed1992

Extensive specifically localized myocardial calcium deposition in a hemodialysis patient.

A 51-year-old female who was hospitalized for evaluation of frequent episodes of hypotension, died unexpectedly. At autopsy, there were many fine, white granular deposits in the myocardium, which were more prominent in the subepicardium of the left ventricle than in the subendocardium. Pathologic calcification is sometimes seen in chronic hemodialysis patients and in some organs the sites of calcium deposition are quite specific. There have been few reports concerning the pattern of calcium deposition in the myocardium and, to our knowledge, the reason for this characteristic distribution is unknown. However it may relate to hydrogen ion concentration in the myocardium.

Calcinosis↗