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Biomedical subjects

K Matoba

Publications and source records attributed to K Matoba.

At least 19 recordsLinked to original sources
PubMed2003

Gastroschisis with omphalomesenteric artery remnant, colonic atresia and arthrogryposis multiplex congenita.

The pathogenesis of gastroschisis (GS) is controversial. We present a case of GS complicated by colonic atresia and arthrogryposis multiplex congenita. This association is attributed to intrauterine vascular compromise. Furthermore, a probable omphalomesenteric artery (OMA) remnant was found on the right side of the defect opposite the umbilicus and extended with bifurcation to the mesenteries of the colon and ileum, between which colonic atresia occurred. This provided further evidence in support of the hypothesis that GS is caused by an intrauterine interruption of OMA.

Abnormalities, Multiple↗
PubMed2001

Growth hormone prevents Fas-induced apoptosis in lymphocytes through modulation of Bcl-2 and caspase-3.

OBJECTIVE: Growth hormone (GH) has been reported to have a potent effect on the immune system. However, the detailed mechanism of the effect of GH on the immune system has not yet been clarified. This study was designed to investigate the nature of this mechanism. METHODS: In the present study, we investigated the effects of GH on the susceptibility of both human CEM/C7 lymphocytes and human IM-9 lymphocytes to Fas-induced apoptosis. RESULTS: Both cell lines expressed GH receptor mRNA. GH rescued Fas-induced suppression of [(3)H]-thymidine incorporation into each cell line. GH prevented Fas-induced apoptosis in each cell line without changing Fas antigen expression. We next investigated the mechanisms of the prevention of Fas-induced apoptosis, by focusing on intracellular molecules related to the apoptotic signal. Bcl-2 expression was increased by GH treatment in both CEM/C7 and IM-9 lymphocytes. GH also downregulated caspase-3 expression and inhibited activation of caspase-3 in both cell lines. CONCLUSION: These findings suggest that GH regulates the human immune system through inhibition of Fas-induced apoptosis in activated T and B lymphocytes.

Antibodies, Monoclonal↗
PubMed2000

Challenges of laparoscopic resection of abdominal neuroblastoma with lymphadenectomy. A preliminary report.

BACKGROUND: The laparoscopic procedure involving total resection of abdominal neuroblastoma combined with lymphadenectomy has not been reviewed in English literature. The aim of this study was to evaluate the significance and accuracy of laparoscopic resection of abdominal neuroblastoma. METHODS: Since July 1997, five patients with abdominal neuroblastoma underwent laparoscopic resection combined with lymphadenectomy or sampling of the lymph nodes. The length of operation, intraoperative blood loss, resectability, and complications were retrospectively reviewed and evaluated. RESULTS: Four cases were managed laparoscopically, but one case was converted to open procedure because of poor visualization around large vessels. The mean operation time was 135 min and the intraoperative blood loss 52 ml. CONCLUSIONS: Good visualization of the primary tumor and large vessels is, arguably, the most important factor for successful completion of this procedure laparoscopically. Precise indicators for laparoscopic resection of abdominal neuroblastoma provide a better prognosis and a good quality of life for children with neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed2000

Chemical structure of nuclear proteins which are phosphorylated during meiotic maturation of starfish oocytes.

Oocytes of the starfish, Asterina pectinifera, are arrested at the G2 phase of meiosis I and possess a prominent germinal vesicle in which maternal stores of nuclear proteins which are destined for use primarily by the early embryo are stored. Germinal vesicle breakdown and subsequent oocyte maturation is triggered by activation of the p34(cdc2)/cyclin B complex, which is present as the preform in the cytoplasm. The aim of the present study was to identify and biochemically characterize in vivo substrates of the kinase. Two nucleic acid binding nuclear proteins designated NAAP1 and NAAP2 were found, both of which contain 345 amino acid residues with pI 3. 6 and which serve as substrates. The only difference between the two proteins was in the primary amino acid sequence at position 51, which is Asn in NAAP1 but Thr in NAAP2. NAAPs are phosphorylated in vivo during oocyte maturation but not at the meiotic G(2) stage. NAAPs are phosphorylated in vitro by the cdc2 kinase on the same site as in vivo. Although there are other evolutionarily conserved consensus sequences for phosphorylation by mitotically active cdc2 kinase in NAAPs and NAAP-derived fragments containing the sequences were efficiently phosphorylated in vitro, these sites in the intact NAAPs were not phosphorylated either in vivo or in vitro. These results suggest that the tertiary structure of NAAPs affects the target specificity of the cdc2 kinase.

Amino Acid Sequence↗
PubMed2000

Molecular characterization of a novel nucleolar protein in starfish oocytes which is phosphorylated before and during oocyte maturation.

In response to 1-methyladenine, a maturation-inducing substance, starfish oocytes undergo reinitiation of meiosis with germinal vesicle breakdown through activation of p34cdc2-cyclin B, which results in the dispersal of the nucleolus. Little information has been elucidated thus far on nucleolar proteins that are phosphorylated by p34cdc2-cyclin B during meiotic maturation. Here, we describe a novel nucleolar protein of the starfish Asterina pectinifera oocyte, which is designated ANO39 and which is phosphorylated during meiotic maturation. A full-length ANO39 cDNA of 2106 base pairs encodes a polypeptide of 346 amino acids having a calculated Mr of 39 005. The amount of ANO39 is kept nearly constant during oocyte maturation and embryogenesis up to the midgastrula stage. The transcript encoding ANO39 was present in growing oocytes but not in full-grown ones, as evidenced by Northern blot hybridization. Ser145 is specifically phosphorylated when ANO39 is incubated in vitro with purified starfish p34cdc2-cyclin B. This phosphorylation site corresponds to that is phosphorylated during meiotic maturation in vivo. Immunoblot analysis using phosphoserine145-specific antibody as a probe revealed that some populations of ANO39 of the immature oocytes at the G2 stage have been already phosphorylated on Ser145 and Ser145 is maximally phosphorylated during meiotic maturation.

Adenine↗
PubMed1999

Phospholipase A2 activity in ox-LDL-stimulated mesangial cells and modulation by alpha-tocopherol.

BACKGROUND: Oxidized LDL increases the production of both prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) in rat mesangial cells. These increases were suppressed by antioxidants such as alpha-tocopherol (alpha-Toc) or probucol. METHODS: We investigated the mechanism by which oxidized LDL leads to an increase in PGE2 production using rat mesangial cells in culture. We also examined how alpha-Toc supresses this augmentation, by measuring intracellular Ca2- and phospholipase A2 (PLA2) activity. RESULTS: In rat mesangial cells, oxidized LDL increased PLA2 activity by increasing the intracellular calcium ion content, which resulted in the induction of PGE2 production. On the other hand, pretreatment of cells with alpha-Toc, which resulted in a large uptake of alpha-Toc in cell membranes, markedly suppressed the augmentation of PGE2 production and PLA2 activity by oxidized LDL in a dose dependent manner. However, cytosolic PLA2 partially purified from mesangial cells was not inhibited by alpha-Toc despite an increase of alpha-Toc. CONCLUSION: These results suggest that the augmentation of PLA2 activity in mesangial cells by oxidized LDL in a result of oxidative stresses, and that the antioxidant action of alpha-Toc is responsible for the suppression of augmentation of PLA2 activity observed in mesangial cells exposed to oxidized LDL.

Animals↗
PubMed1999

Characterization, cDNA cloning, and functional expression of mouse ileal sodium-dependent bile acid transporter.

Mouse ileal sodium dependent bile acid transporter (ISBT) was characterized using isolated enterocytes. Only enterocytes from the most distal portion showed Na+-dependent [3H]taurocholate uptake. Northern blot analysis using a probe against mouse ISBT revealed the expression of mouse ISBT mRNA to be restricted to the distal ileum. The Km and Vmax for Na+-dependent [3H]taurocholate transport into isolated ileocytes were calculated as 27 microM and 360 pmol/mg protein/min, respectively. Uptake of [3H]taurocholate was inhibited by N-ethylmaleimide. We have cloned ISBT cDNA from mouse ileum. The cDNA included the entire open reading frame coding 348 amino acid protein with seven hydrophobic segments and two N-glycosylation sites. COS-7 cells transfected with the expression vector containing this cDNA expressed Na+-dependent [3H]taurocholate uptake activity with a Km of 34 microM.

Amino Acid Sequence↗
PubMed1999

Efficacy of low-dose prednisolone maintenance for saliva production and serological abnormalities in patients with primary Sjögren's syndrome.

OBJECTIVE: To evaluate efficacy of low dose prednisolone maintenance in patients with primary Sjögren's syndrome. METHODS: An open, prospective pilot study of prednisolone for the treatment of 20 patients with primary Sjögren's syndrome was performed. Evaluations included the amount of whole saliva measured by the Saxon test, serological abnormalities and oral symptoms. RESULTS: Initial dosage of prednisolone was 15.0+/-1.5 (mean+/-SEM) mg/day. Maintenance dosage was 7.5-5.0 mg/day. Follow-up period was 26.3+/-3.8 months (range 3-48). The amount of whole saliva significantly increased after 1 month of prednisolone therapy and the increase continued up to 48 months by maintaining low-dose prednisolone. A mean percent increase of whole saliva from baseline ranged from +105.2+/-36.2% to +245.7+/-82.1%. Serum IgG, anti-SS-A/Ro, anti-SS-B/La antibodies and IgM rheumatoid factor levels significantly decreased throughout the study with partial decreases of IgA and IgM levels. The improvement of subjective oral symptoms was also confirmed. CONCLUSION: Low-dose prednisolone maintenance may have a worthwhile clinical benefit in patients with primary Sjögren's syndrome that deserves further evaluation in a controlled trial.

Adult↗
PubMed1998

[A case of systemic lupus erythematosus with pure red cell aplasia possibly caused by persistent infection of human parvovirus B 19].

We reported a 68-old female who was diagnosed to have systemic lupus erythematosus 18 years ago. She had been well under 5 mg of prednisolone until 1995, when she felt severe shortness of breath. Laboratory examinations disclosed severe anemia accompanying mild thrombocytopenia. Bone marrow aspiration revealed a complete absence of erythroid progenitor cells. She was diagnosed to have pure red cell aplasia (PRCA) as well as antiphospholipid syndrome. A judicious use of methylprednisolone including pulse therapy resulted in a prompt resolution of anemia as well as thrombocytopenia and the dose of corticosteroid was tapered successfully thereafter. Persistent infection of HPV B 19 in the patient with inactive SLE was considered as a main cause of PRCA because not only IgG-HPV B 19 antibody but viral DNA was demonstrated in her serum at the time of admission. The relationship between PRCA and anti-phospholipid syndrome in this patient was also noted.

Aged↗
PubMed1995

[Usefulness of palliative care for the patients with recurrent gastric cancer by home-IVH].

Depending upon the type of cancer involved, the period of the end stage varies greatly, and with it decreases the quality of life (QOL). In gastric cancer, for example, the terminal stage is usually short and the QOL diminishes abruptly. Thus, it takes time keeping this decrease in QOL to minimum, despite the complications, so that the patient's last days will be even somewhat more acceptable. Improvement in QOL for the patient who cannot eat due to recurrent gastric cancer can be effectively achieved by alleviation through IVH. With this in mind, the conditions consonant with the application of home IVH are as follows: 1) The patient's pain can be kept under control at home. 2) The patient wishes to remain. 3)There is sufficient human support at home. The caretakers in the family, and especially the key person(s) must exert much effort and labor and they need rest as well. Home medical care in the terminal stage presupposes a social environment involving day care, short stay, and hospice nursing facilities of all kinds. At present, public services of this kind differ with the community, much remains uninformed to public, and clinic-hospital networking will be needed more than ever. In this difficult situation, the home-care medical services provided by the private sector are effective. These services are only for the short term, of course, and there will be a financial problem. Various measures (tax deduction, public assistance) must be considered to support the patients and caretakers.

Adult↗
PubMed1994

Effects of sarpogrelate on serotonin-induced increases in cytosolic Ca2+ in cultured rat mesangial cells.

The effects of the new 5-HT2A receptor antagonist sarpogrelate on the cellular action of serotonin were examined in cultured rat mesangial cells by measuring cytosolic free calcium concentration ([Ca2+]i). Sarpogrelate inhibited serotonin-induced increases in [Ca2+]i in a concentration-dependent manner. M1, a major metabolite of sarpogrelate, also exhibited an inhibitory effect exceeding that of sarpogrelate. The inhibitory effects of sarpogrelate and M1 were abolished by washing out these compounds. In contrast, the increase in [Ca2+]i induced by angiotensin II or arginine vasopressin was not affected by pretreatment of the cells with sarpogrelate or M1. These results suggest that sarpogrelate and its major metabolite (M1) act as reversible and specific 5-HT2A receptor antagonists against the contractile action of platelet-derived serotonin in mesangial cells.

Angiotensin II↗
PubMed1994

Anaerobic threshold can provoke microalbuminuria in non-insulin-dependent diabetics.

We examined two groups of non-insulin-dependent diabetic men (group A, 13 patients without microalbuminuria; group B, 9 patients with intermittent microalbuminuria) to ascertain whether the anaerobic threshold (AT) can provoke microalbuminuria, comparing them with 12 healthy subjects matched for age and sex (group C). All subjects exercised on a bicycle ergometer until the AT was reached. In intermittent microalbuminuria, the albumin:creatinine ratio (ACR) was over 0.25 mg/mmol.Cr 1-3-fold in 5 measurements. The ACR after exercise was increased to over 0.25 mg/mmol.Cr in 4/9 cases in group B (P < 0.05), in 2/13 cases in group A, but not at all in group C. We also studied the mechanism of exercise-induced microalbuminuria. In group B, ACR before exercise correlated positively with the baseline plasma glucose. Furthermore, positive correlation was found between ACR after exercise and HbA1c in group B. The AT did not affect the urinary beta 2-microglobulin in any groups. The plasma atrial natriuretic factor (ANF) after exercise was elevated most prominently in group B (P < 0.05). Positive correlation was found between increments of ACR and increments of plasma ANF after exercise in group B. We conclude that the AT can provoke microalbuminuria in some non-insulin-dependent diabetics. The plasma ANF and metabolic control may play an important role in the pathophysiology of exercise-induced microalbuminuria.

Adult↗
PubMed1990

Relationship between age-adjusted heart rate and anaerobic threshold in estimating exercise intensity in diabetics.

We compared heart rates at the anaerobic threshold (AT) with age-adjusted heart rates in two groups of diabetics (DMY, mean age 31; and DMO, mean age 48) to ascertain whether the AT is useful for evaluating the intensity of exercise therapy for diabetics. In both the DMY and DMO groups the AT was reached at lower heart rates than in control groups of healthy subjects, indicating that the metabolism of diabetics may become anaerobic if their age-adjusted heart rate is higher than their heart rate at the AT. In this study, 86% of the DMY and 50% of the DMO group had age-adjusted heart rates, at 70% of maximum, that were higher than the heart rates at the AT. Thus, exercise intensity with an age-adjusted heart rate at 70% of maximum may induce anaerobic metabolism in some diabetics. We also studied the relationship between exercise intensity and the glycosylated hemoglobin (HbA1c) level at the AT in order to understand why the heart rate at the AT in diabetics was less than in healthy subjects. Exercise intensity at the AT in both diabetic groups was less than in healthy groups, and so did not increase the heart rates. Both exercise intensity and the heart rate at the AT were inversely related to the HbA1c level, suggesting that HbA1c may be important for keeping low the exercise intensity and the heart rate at the AT. As far as possible, we excluded cardiovascular autonomic neuropathy, so that it could not explain the mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Glomerular apolipoprotein B deposition in glomerular diseases].

In an attempt to elucidate the relationship between the progress of glomerular injury and abnormalities of lipid metabolism, we investigated glomerular deposition of apolipoprotein B (apo B) in renal biopsy specimens from 60 patients with glomerular diseases by indirect immunofluorescence using antihuman apo B-100 monoclonal antibody in comparison with clinical and histopathological findings. The patients were divided into 2 groups according to the intensity in staining of apo B in glomerulus (group A: negative or weakly positive; and group B: definitely positive). Staining of apo B in glomerulus was found in 37 patients (62%). The levels of serum total cholesterol, phospholipids, low density lipoprotein cholesterol and apo B in group B were significantly higher than in group A. The urinary protein excretion in group B was greater than that in group A. Group B was also shown to have a significantly decrease in renal function. Light microscopy revealed severe mesangial proliferation in patients with IgA nephropathy of group B. These findings suggested that glomerular apo B containing-lipoprotein deposition may play an important role in the progression of glomerular injury.

Adolescent↗