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Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 253 records · Page 14Linked to original sources

Effects of recombinant thrombopoietin on the growth of murine primitive and committed hematopoietic progenitors in serum-free culture.

BACKGROUND: The aim of the present study was to determine the effect of thrombopoietin (Tpo) in combination with other cytokines on the growth of murine megakaryocytic, granulocyte-macrophage, erythroid and primitive hematopoietic progenitor cells, excluding possibilities of synergistic effects by serum factor(s). METHODS: Serum-free clonogenic assay systems were used for assay of colony forming units in megakaryocytes (CFU-Mk), colony forming units in granulocytes-macrophages (CFU-GM), burst-forming units in erythrocytes (BFU-E) in marrow of normal mice and of high proliferative potential colony forming cells in 5-fluorouracil-treated marrow. RESULTS: Serum-free culture enabled megakaryocyte colony growth by recombinant murine (rm) Tpo and this was synergistically supported with rm interleukin (IL)-3, rm stem cell factor (SCF) or recombinant human (rh) erythropoietin (Epo). Recombinant human IL-6, rhIL-11 and rm granulocyte-macrophage colony stimulating factor (GM-CSF) showed synergistic effects with rmTpo only in the presence of serum. Recombinant murine IL-3 or rmSCF increased the large colonies and mixed-type colonies containing other populations, suggesting that these cytokines promoted the proliferation of immature populations of CFU-Mk. The rmTpo enhanced the growth of granulocyte-macrophage (GM) colonies stimulated by rmGM-CSF or rmIL-3 and erythroid bursts by rhEpo, with or without rmIL-3. The rmTpo also significantly increased HPP colonies in synergy with rmIL-3 only in the presence of serum or rmSCF. CONCLUSION: Serum-free culture is valuable for evaluating synergistic effects of cytokines and Tpo acts not only on megakaryocytic progenitors but also on granulocyte-macrophage, erythroid and primitive progenitor cells in combination with other cytokines, such as rmIL-3 and rmSCF. However, serum or SCF was required for enhancement of the colony growth of primitive progenitors by Tpo.

Animals↗

Intrarenal pelvic papillary Wilms' tumor associated with aniridia: a case report.

BACKGROUND: Intrarenal pelvic Wilms' tumor in a papillary growth is rare in children. A case of a two-year-old infant with Wilms' tumor associated with congenital aniridia is reported. RESULTS: A chromosomal abnormality (11p13 deletion) was found in this patient. The tumor was well evaluated by ultrasonography, computed tomography and magnetic resonance imaging. DISCUSSION: Previous case reports are briefly reviewed and the clinical characteristics disclosed.

Aniridia↗

Susceptibility of TT virus to interferon therapy.

TT virus (TTV) is a newly identified single-stranded DNA virus. We retrospectively analysed serum samples from sixteen patients, infected with both hepatitis C virus (HCV) and TTV, and who had been treated with interferon. An elevated serum alanine aminotransferase level after interferon was associated with persistence of HCV (abnormal in five of seven patients with persistence of HCV compared with normal in all nine patients who showed eradication of HCV) irrespective of persistence of TTV. Comparison of partial viral DNA nucleotide sequences and phylogenetic analysis showed that viral strains that had a high identity to the prototype virus were more resistant to interferon than those showing low nucleotide sequence identity. Although we observed no liver cell injury caused by persistent TTV infection, the mechanism(s) of TTV resistance to interferon should be further investigated for a better understanding of viral diseases and establishment of therapy.

Alanine Transaminase↗

Epidermal growth factor-dependent dissociation of CrkII proto-oncogene product from the epidermal growth factor receptor in human glioma cells.

Human glioma cells frequently overexpress epidermal growth factor receptor (EGFR). We found that the CrkII proto-oncogene product was associated with the EGFR in human glioma cells in the absence of epidermal growth factor (EGF). EGF stimulation of glioma cells induced the phosphorylation of tyrosine 221 of the CrkII protein, which correlates with its dissociation from the EGFR. By contrast, Shc and Grb2 were inducibly associated with the EGFR in response to EGF stimulation of glioma cells. In A431 cells, epidermoid carcinoma cells which overexpress EGFR, CrkII was tyrosine-phosphorylated and associated with the EGFR in an EGF-dependent manner. Therefore, the dissociation of CrkII from the EGFR upon stimulation with EGF appears to be specific to glioma cells. The Cbl oncogene product was also tyrosine-phosphorylated in U87MG glioma cells upon EGF stimulation. However, unlike in other cell lines, CrkII was not inducibly bound to Cbl in U87MG glioma cells. Thus, EGF-dependent binding of CrkII to phosphotyrosine-containing proteins appears to be suppressed in glioma cells. To evaluate the physiological role of dissociation of CrkII from EGFR, we expressed the CrkII-23 mutant in glioma cells. CrkII-23 mutant, which was isolated as a suppressor gene of the EGF-dependent transformation of NRK cells, binds constitutively to EGFR. We found that expression of CrkII-23 inhibited the anchorage-independent growth of the glioma cells in the presence of EGF. Taken together, these data implicate EGF-dependent dissociation of CrkII from EGFR in the oncogenicity of human glioma cells.

Cell Adhesion↗

[Study on the verotoxin-producing Escherichia coli--isolation of the bacteria from deer dung].

To identify the source and route of verotoxin-producing Escherichia coli (VTEC) infection in humans, we tried to isolate VTEC from fresh deer dung collected from free-range animals in two parks during the period from August 1997 to January 1998. The results are presented below. 1) VTEC were isolated from 21 of 200 deer dung samples (10.5%), consisting of 15 of 100 samples (15.0%) collected in park A and 6 of 100 samples (6.0%) collected in park B, suggesting that the incidence of VTEC isolation differs depending on location. 2) With respect to typing of verotoxin, the 21 isolated VTEC strains consisted of 10 strains (47.6%) as VT1 producer, 5 strains (23.8%) as VT2 producer, and 6 strains (28.6%) as double producer of both types. 3) With respect to serogroup of the isolated VTEC strains, 2 strains belonged to O128:H2.1 strain each belonged to the O8:H10, O128:H12, and O169:HUT groups. The remaining 16 strains failed to be identified as particular serotypes. Regarding local distribution of the serotype, in park A, 1 strain each belonged to the O128:H2, O8:H10, and O169:HUT groups. The remaining 12 strains did not clearly show particular serotypes. In park B, 2 strains belonged to O128:H2, and 4 strains failed to show particular serotypes. The remaining 1 strains showed autoagglutination. In conclusion, we isolated VTEC strains from deer that showed types of toxin and serogroups identical to those of human VTEC. Therefore, VTEC found in deer dung could well be a source of VTEC-infectious diseases in humans.

Animals↗

Failure of cdc2 promoter activation and G(2)/M transition by ANG II and AVP in vascular smooth muscle cells.

The physiological role of the vasoconstrictive hormones arginine vasopressin (AVP) and angiotensin II (ANG II) in the development of vascular hyperplasia is still unclear. We examined the effects of these hormones on cell cycle regulation of cultured rat vascular smooth muscle cells (VSMC). AVP and ANG II were able to induce G(1)/S transition and DNA synthesis in serum-starved quiescent VSMC but failed to promote further progression into G(2)/M phases. AVP and ANG II enhanced the expression and activity of cdk2, cyclin E, and proliferating cell nuclear antigen but did not induce expression of cdc2/cyclin B complex, a critical regulator of G(2)/M transition. The failure of cdc2 mRNA induction was found to be caused by a defect in cdc2 promoter activation. Binding of free E2F-1 to the cdc2 promoter did not occur in hormone-treated VSMC, which may account for the defective induction of cdc2. The absence of cdc2 promoter activation and G(2)/M transition may be important for the prevention of hyperplasia under physiological conditions but underlies the hypertrophy of VSMC.

Angiotensin II↗

Angiolipoma of the colon with right lower quadrant abdominal pain.

BACKGROUND/AIM: An angiolipoma is a common benign neoplasm with a characteristic vascular component that occurs in the subcutaneous tissue and rarely in the gastrointestinal tract. We report on a 69-year-old man with a submucosal angiolipoma in the cecum. METHODS: This patient was treated with a laparoscopy-assisted ileocecostomy, and a side-to-side anastomosis was performed extracorporeally. RESULTS: A light microscopic study supported the diagnosis of an angiolipoma of the colon. After 5 years of follow-up, the patient has no symptoms or signs of recurrence. CONCLUSION: The colonic angiolipoma was successfully removed using a minimally invasive laparoscopic technique.

Abdominal Pain↗

Increased urinary excretion of macrophage-colony-stimulating factor (M-CSF) in patients with IgA nephropathy: tonsil stimulation enhances urinary M-CSF excretion.

Upper respiratory tract infection including chronic tonsillitis is considered to be involved in the onset and/or the progression of IgA nephropathy. It is well known that deterioration of urinary findings occurs after episodes of upper respiratory tract infection in patients with IgA nephropathy. We previously showed that the expression of macrophage-colony-stimulating factor (M-CSF) is increased in the glomeruli of patients with IgA nephropathy and correlated with glomerular mesangial proliferation, suggesting that M-CSF plays an important role in the progression of IgA nephropathy. In the present study, we measured the serum and urinary concentrations of M-CSF in patients with IgA nephropathy associated with chronic tonsillitis. Furthermore, we evaluated the effects of the local provocation test of tonsils (mechanical tonsil stimulation) on the serum and urinary concentrations of M-CSF in the following three groups: (1) IgA nephropathy with severe mesangial proliferation, (2) IgA nephropathy with mild mesangial proliferation, and (3) patients with chronic tonsillitis without renal disease. The serum and urinary levels of M-CSF in the groups with severe and mild IgA nephropathy were significantly higher than those in the chronic tonsillitis group. The urinary M-CSF level but not the serum M-CSF level was positively correlated with the degrees of mesangial proliferation and glomerular M-CSF expression in the renal biopsy specimens. The urinary M-CSF concentration was significantly increased after tonsillitis stimulation in both mild and severe IgA nephropathy groups. Enhanced urinary excretion of M-CSF prolonged for 7 days after tonsil stimulation in the severe IgA nephropathy group; in contrast, the urinay M-CSF level was increased for only 2 days after tonsil stimulation in the mild IgA nephropathy group. The urinary M-CSF level was not changed in the chronic tonsillitis group after tonsil stimulation. The serum concentrations of M-CSF were not changed after tonsil stimulation in these three groups. Our present results suggest that tonsil stimulation contributes to the progression of IgA nephropathy via enhancement of glomerular production of M-CSF. The urinary excretion of M-CSF may be a useful predictor to evaluate the relevance of chronic tonsillitis to the disease and the indication of tonsillectomy in patients with IgA nephropathy.

Adult↗

Site-directed mutagenesis of two zinc-binding centers of the NADH-dependent phenylacetaldehyde reductase from styrene-assimilating Corynebacterium sp. strain ST-10.

Phenylacetaldehyde reductase (PAR) with a unique and wide substrate range from styrene-assimilating Corynebacterium sp. strain ST-10, which is a useful biocatalyst producing chiral alcohols, has been found to belong to a family of zinc-containing, long-chain alcohol dehydrogenases (ADHs) on the basis of the primary structure similarity. The enzyme contains 2 moles of zinc per mole of subunit. The amino acid residues assumed to be three catalytic and four structural zinc-binding ligands were characterized by site-directed mutagenesis, compared with other zinc-containing, long-chain ADHs. Sixteen PAR mutants gave measurable but rather low activities toward phenylacetaldehyde, n-hexyl aldehyde, and 2-heptanone, although they maintained the activities of 8 to 16% of that of wild-type PAR for an acetophenone substrate except that the D153N mutant showed quite low activity. The results suggested that the seven residues present in PAR were probably zinc-binding ligands, and mutation in these residues caused a change in activities for some substrates.

Alcohol Oxidoreductases↗

Relationship between exercise capacity and ventilatory equivalent for carbon dioxide in patients with stable old myocardial infarction.

The aim of the present study was to evaluate the relationship between exercise capacity and ventilatory response in patients with stable old myocardial infarction. We performed cardiopulmonary exercise test in 61 patients with stable old myocardial infarction and in 30 healthy men. Each subject exercised on a bicycle ergometer until exhaustion. Patients who had anginal pain or electrocardiographic ischemic changes during exercise were excluded. The patients were classified into three groups according to peakVO2 achieved during exercise, using Weber's method: group A, peakVO2 > or = 21 ml/min/kg (n = 4); group B, 14 < or = peakVO2 < 21 ml/min/kg (n = 45); and group C, peakVO2 < 14 ml/min/kg (n = 12). With progressive increases in VCO2, VE increased linearly below the anaerobic threshold (AT) level. The slope of the linear regression line between VCO2 and VE (SLOPE) was calculated in each subject. The mean SLOPE of the healthy men (group N) and groups A, B and C were 25.8 +/- 0.5, 25.1 +/- 0.5, 28.9 +/- 0.8 and 37.1 +/- 1.7 (x 10(-3), respectively. Thus, the SLOPE was steeper in patients with lower peakVO2. It is difficult to perform a maximal exercise tolerance test on patients with chronic heart failure to evaluate their exercise capacity. We can assess exercise capacity by the slope of the linear regression line between VCO2 and VE (SLOPE) at the lower exercise level.

Aged↗

Altered hypothalamic function in response to glucose ingestion in obese humans.

The hypothalamus plays a central role in the regulation of energy intake and feeding behavior. However, the presence of a functional abnormality in the hypothalamus in humans that may be related to excess energy intake and obesity has yet to be demonstrated in vivo. We, therefore, used functional magnetic resonance imaging (fMRI) to monitor hypothalamic function after oral glucose intake. The 10 obese (34 +/- 2 years of age, BMI 34.2 +/- 1.3 kg/m2) and 10 lean (32 +/- 4 years of age, BMI 22.0 +/- 0.9 kg/m2) subjects with normal glucose tolerance ingested 75 g of glucose while a midsagittal slice through the hypothalamus was continuously imaged for 50 min using a conventional T2*-weighted gradient-echo pulse sequence. After glucose ingestion, lean subjects demonstrated an inhibition of the fMRI signal in the areas corresponding to the paraventricular and ventromedial nuclei. In obese subjects, this inhibitory response was markedly attenuated (4.8 +/- 1.3 vs. 7.0 +/- 0.6% inhibition, P < 0.05) and delayed (9.4 +/- 0.5 vs. 6.4 +/- 0.5 min, P < 0.05) compared with that observed in lean subjects. The time taken to reach the maximum inhibitory response correlated with the fasting plasma glucose (r = 0.75, P < 0.001) and insulin (r = 0.47, P < 0.05) concentrations in both lean and obese subjects. These results demonstrate in vivo, for the first time, the existence of differential hypothalamic function in lean and obese humans that may be secondary to obesity.

Adult↗

Insulin sensitivity indices obtained from oral glucose tolerance testing: comparison with the euglycemic insulin clamp.

OBJECTIVE: Several methods have been proposed to evaluate insulin sensitivity from the data obtained from the oral glucose tolerance test (OGTT). However, the validity of these indices has not been rigorously evaluated by comparing them with the direct measurement of insulin sensitivity obtained with the euglycemic insulin clamp technique. In this study, we compare various insulin sensitivity indices derived from the OGTT with whole-body insulin sensitivity measured by the euglycemic insulin clamp technique. RESEARCH DESIGN AND METHODS: In this study, 153 subjects (66 men and 87 women, aged 18-71 years, BMI 20-65 kg/m2) with varying degrees of glucose tolerance (62 subjects with normal glucose tolerance, 31 subjects with impaired glucose tolerance, and 60 subjects with type 2 diabetes) were studied. After a 10-h overnight fast, all subjects underwent, in random order, a 75-g OGTT and a euglycemic insulin clamp, which was performed with the infusion of [3-3H]glucose. The indices of insulin sensitivity derived from OGTT data and the euglycemic insulin clamp were compared by correlation analysis. RESULTS: The mean plasma glucose concentration divided by the mean plasma insulin concentration during the OGTT displayed no correlation with the rate of whole-body glucose disposal during the euglycemic insulin clamp (r = -0.02, NS). From the OGTT, we developed an index of whole-body insulin sensitivity (10,000/square root of [fasting glucose x fasting insulin] x [mean glucose x mean insulin during OGTT]), which is highly correlated (r = 0.73, P < 0.0001) with the rate of whole-body glucose disposal during the euglycemic insulin clamp. CONCLUSIONS: Previous methods used to derive an index of insulin sensitivity from the OGTT have relied on the ratio of plasma glucose to insulin concentration during the OGTT. Our results demonstrate the limitations of such an approach. We have derived a novel estimate of insulin sensitivity that is simple to calculate and provides a reasonable approximation of whole-body insulin sensitivity from the OGTT.

Administration, Oral↗

Improvement of control cable system of trans-humeral body-powered prostheses.

For the purpose of improving the efficiency of a body-powered prosthesis, a control cable system was developed which uses a pulley and a cable housing which includes a highly slippery plastic liner. Improvements were also made to the harness. In this paper, the mechanism of these systems is firstly described and then, the results of a clinical evaluation test of a practical model is presented along with an efficiency evaluation by a testing instrument. For the design of each system, the material and size suitable for the conditions of cosmetic and general versatility were considered. The clinical test was performed on 12 subjects to prove the effectiveness of the system. This test procedure was repeated. These tests proved the effectiveness of the systems.

Humans↗

Preoperative identification of meningiomas that are highly likely to recur.

OBJECT: Although generally they are well-circumscribed benign tumors, meningiomas recur even after complete removal. The aims of this study are to identify preoperatively groups of patients who have a high risk of meningioma recurrence by reviewing their clinicoradiological features and to plan appropriate treatments. METHODS: One hundred one patients who underwent macroscopically complete removal of meningiomas were observed postoperatively for at least 5 years or until tumor recurrence. Preoperative radiological findings and clinical characteristics were assessed. Fifteen meningiomas recurred during the follow-up period, which extended to a maximum duration of 18 years. On univariate analysis, tumor size and shape, relation to the major sinuses, calcification, bone changes, and characteristics of the tumor-brain interface were significant predictive factors for recurrence. Patient age and gender were not deemed significant. Multivariate analysis revealed that only the shape of the tumor was significant; both "mushrooming" and lobulated meningiomas were more likely to recur than round ones. Recurrences most frequently occurred at the edge of the dural resection after a Simpson Grade I removal, whereas local recurrences were predominant after a Simpson Grade II or III removal. CONCLUSIONS: Meningiomas with mushrooming or lobulated shapes should be treated more aggressively with a wider dural excision. This is not usually necessary for round tumors, although it may be beneficial in younger patients.

Adult↗

Noninvasive evaluation of the malignant potential of intracranial meningiomas performed using proton magnetic resonance spectroscopy.

OBJECT: Controversy exists about correlations between histological tumor grade and magnetic resonance (MR) spectroscopy data. The authors studied single-voxel proton MR spectroscopy as a noninvasive way to evaluate grade of malignancy in intracranial meningiomas. METHODS: The authors compared the results of MR spectroscopy with those derived by the MIB-1 staining index (SI) in 29 meningiomas. Proton MR spectroscopy was performed using stimulated echo acquisition and volume-localized solvent-attenuated proton nuclear MR sequences before surgery or other therapy. Twenty-four tumors were histologically benign (13 meningothelial, three fibrous, four transitional, three angiomatous, and one chordoid); four were atypical (Grade II), and one was papillary (Grade III). The mean MIB-1 SI in the benign group was significantly lower than those in the other groups (p = 0.0041). The mean choline-containing compound (Cho)/ creatine and phosphocreatine (Cr) ratios in the benign and nonbenign groups were 2.56+/-1.26 and 7.85+/-3.23, respectively (p = 0.0002). A significant linear correlation was observed between the Cho/Cr ratio and the MIB-1 SI (r0.05 = 0.74, p<0.001). Necrosis was present histologically in four of the five meningiomas classified either as atypical or papillary. Magnetic resonance spectroscopy revealed a methylene signal in these meningiomas that was not detected in benign meningiomas. Of the five meningiomas in which only a lactate signal was observed, two were benign and the MIB-1 SI in these two benign meningiomas was higher than the mean value for the benign group. Alanine, detected in 12 of 30 meningiomas, did not correlate with either tumor grade or Cho/Cr ratio. CONCLUSIONS: Proton MR spectroscopy is a useful diagnostic method for determining the proliferative or malignant potential of meningiomas according to the Cho/Cr ratio. A lactate and/or methylene signal suggests a high-grade tumor.

Adult↗