Biomedical subjects

M Murakami

Publications and source records attributed to M Murakami.

At least 253 records · Page 14Linked to original sources

PubMed2000

Effects of epinephrine and lactate on the increase in oxygen consumption of nonexercising skeletal muscle after aerobic exercise.

The purpose of this study was to measure O2 consumption of nonexercising skeletal muscles (VO2nonex) at rest and after aerobic exercise and to investigate the stimulant factors of O2 consumption. In experiment 1, we measured the resting metabolic rate of the finger flexor muscles in seven healthy males by 31P-magnetic resonance spectroscopy during a 15 min arterial occlusion. In experiment 2, the VO2nonex of the finger flexor muscles was measured using near infrared continuous wave spectroscopy at rest, immediate postexercise, and 3, 5, 10, 15, and 20 min following a cycling exercise at a workload corresponding to 50% of peak pulmonary O2 uptake for 20 min. We also monitored deep tissue temperature in the VO2nonex measurement area and determined catecholamines and lactate concentrations in the blood at rest and immediate postexercise. VO2nonex at rest was 1.1 +/- 0.1 microM O2/S (mean +/- standard error) and VO2nonex after exercise increased 59.6 +/- 7.2% (p < 0.001) from the resting values. There were significant correlations between the increase in VO2nonex and the increase in epinephrine concentration (p < 0.01), and between the increase in VO2nonex and the increase in lactate concentration (p < 0.05). These results suggest that epinephrine and lactate concentrations are important VO2nonex stimulant factors.

Adult↗

PubMed2000

Cloning and sequencing of the gene encoding an aldehyde dehydrogenase that is induced by growing Alteromonas sp. Strain KE10 in a low concentration of organic nutrients.

The protein composition of Alteromonas sp. strain KE10 cultured at two different organic-nutrient concentrations was determined by using two-dimensional polyacrylamide gel electrophoresis. The cellular levels of three proteins, OlgA, -B, and -C, were considerably higher in cells grown in a low concentration of organic nutrient medium (LON medium; 0.2 mg of carbon per liter) than cells grown in a high concentration of organic nutrient medium (HON; 200 mg of C liter(-1)) or cells starved for organic nutrients. In the LON medium, the cellular levels of the Olg proteins were higher at the exponential growth phase than at the stationary growth phase. A sequence of the gene for OlgA revealed that the amino acid sequence had a high degree of similarity to the NAD(+)-dependent aldehyde dehydrogenases of several bacteria. OlgA, expressed in Escherichia coli, catalyzed the dehydrogenation of acetaldehyde, propionaldehyde, and butyraldehyde. The aldehyde dehydrogenase activity of KE10 was higher in cells growing exponentially in LON medium than in HON. OlgA may be involved in the growth under low-nutrient conditions. The physiological role of OlgA is discussed here.

Aldehyde Dehydrogenase↗

PubMed2000

Identification of monoclonal insulin autoantibodies in insulin autoimmune syndrome associated with HLA-DRB1*0401.

We have characterized HLA and insulin autoantibodies in a Japanese female patient with insulin autoimmune syndrome. Serological HLA typing demonstrated the patient had HLA-DR4, and DNA typing showed she had HLA-DRB1*0401 which has not been reported in patients with insulin autoimmune syndrome in Japan. A single binding affinity of insulin autoantibodies was demonstrated by Scatchard analysis and immunoglobulin class of insulin autoantibodies was exclusively IgG-kappa. HLA-DRB1*0406 is strikingly associated with patients with insulin autoimmune syndrome who have polyclonal insulin autoantibodies. The present report demonstrated the first Japanese patient with insulin autoimmune syndrome carrying HLA-DRB1*0401 who was revealed to have monoclonal insulin autoantibodies. The present results indicate that HLA molecules are the major determinants of polyclonal insulin autoantibodies and monoclonal insulin autoantibodies in insulin autoimmune syndrome.

Aged↗

PubMed2000

Cloning of novel soluble gp130 and detection of its neutralizing autoantibodies in rheumatoid arthritis.

In an attempt to isolate disease-associated autoantigens in rheumatoid arthritis (RA), we cloned a new autoantigen named gp130-RAPS, which is a novel soluble form of the IL-6 signal-transducing molecule gp130. gp130-RAPS is a 50-kDa protein translated from alternatively spliced mRNA and has a truncated form of gp130 with a unique sequence, Asn-Ile-Ala-Ser-Phe (NIASF), in its COOH-terminus. We observed serum antibodies to this NIASF sequence frequently in patients with RA, but not in those with other systemic rheumatic diseases or in healthy subjects. In RA, detection of those antibodies was significantly associated with disease activity indices such as serum C-reactive protein (CRP) levels, erythrocyte sedimentation rate, blood platelet counts, and serum IL-6 concentration. In vitro experiments revealed that gp130-RAPS inhibited IL-6 activity, and this inhibition was neutralized by antibodies to the COOH-terminus of gp130-RAPS derived from patients with RA. Thus, autoantibody to gp130-RAPS may play an important role in the progression of RA by promoting IL-6 activity. Inspection of autoantibodies to gp130-RAPS may become a practical clinical test for RA. gp130-RAPS and its autoantibody provide a new clue to the complicated pathogenesis of RA.

Animals↗

PubMed2000

Plasma soluble interleukin-2 receptor levels during and after upper abdominal surgery.

Soluble interleukin-2 (IL-2) receptor (sIL-2R) is reported to be up-regulated in inflammatory disorders. Although sIL-2R may modulate perioperative inflammatory responses, it remains unclear whether upper abdominal surgery affects plasma sIL-2R levels. We evaluated the influence of major abdominal surgery on plasma sIL-2R levels. Ten patients scheduled for upper abdominal surgery received anaesthesia with isoflurane, nitrous oxide, and epidural block. Plasma sIL-2R and IL-6 levels were determined at pre-anaesthesia, 0, 2, and 4 hours during surgery, and on postoperative days 1 (POD1) and 3 (POD3). The plasma levels of sIL-2R decreased significantly and achieved their minimum value at 4 hours (677.0 +/- 125.3 pg/ml, P < 0.01 compared to pre-anaesthesia value; 924.5 +/- 178.8 pg/ml, 95% confidence interval = 122.2-550.4). The plasma sIL-2R levels increased on POD1 (1336.5 +/- 174.0 pg/ml) and POD3 (1629.0 +/- 262.8 pg/ml), and reached a level significantly higher than the baseline (P < 0.05 and P < 0.001, 95% confidence interval = 93.4-730.6 and 402.8-1006.2, respectively). The plasma sIL-2R levels on POD3 significantly correlated with the peak IL-6 levels (r = 0.67, P < 0.05). The plasma sIL-2R levels on POD3 correlated with the amount of intraoperative bleeding (r = 0.66, P < 0.05). In conclusion, we found that major abdominal surgery induces characteristic changes in plasma soluble IL-2 receptor levels.

Abdomen↗

PubMed2000

Expression of type II iodothyronine deiodinase in brain tumors.

Type II iodothyronine deiodinase (DII) messenger ribonucleic acid (mRNA) and its activity have been demonstrated in human normal brain. Although DII activity has been demonstrated in brain tumors, expression of DII mRNA has not been studied in these tumors. To investigate the mechanisms involved in the expression of DII activity in brain tumors, we studied DII mRNA and DII activity in astrocytoma (two cases), glioblastoma (three cases), and oligodendroglioma (one case). DII mRNA, the size of which was indistinguishable from that in control cerebral cortical tissue, was demonstrated in all of the brain tumors tested, although the intensity of the hybridization signal showed wide variation among the tumors. DII activity was also detected in all tumors. DII mRNA and DII activity were highest in the tissue from oligodendroglioma. A significantly positive correlation was observed between DII mRNA and DII activity in these tumors (r = 0.94; P < 0.01), suggesting that DII expression in brain tumors is regulated at the pretranslational level. The present results demonstrate, for the first time, that DII mRNA as well as DII activity are expressed in brain tumors, and that DII mRNA is significantly correlated with DII activity in those tissues.

Adult↗

PubMed2000

Effect of murine kidney extracts on the proliferation of hematopoietic progenitor cells in human umbilical cord blood.

We examined the effect of murine kidney extract (MKE) on the clonal growth of highly purified CD34+ hematopoietic progenitor cells from human umbilical cord blood. MKE did not affect the total number of colonies of erythroid burst-forming units (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM) or granulocyte-erythroid-macrophage-megakaryocyte colony-forming units (CFU-Mix/CFU-GEMM) in a methylcellulose culture with exogenous recombinant human granulocyte colony-stimulating factor, granulocytemacrophage colony-stimulating factor, interleukin-3, stem cell factor and erythropoietin. MKE significantly increased the proportion of BFU-E- or CFU-Mix-derived colonies, and suppressed the formation CFU-GM-derived colonies depending on the MKE dose. However, because of an increase in small megakaryocyte colonies derived from mature CFU-Meg MKE increased by approximately 40% the growth of megakaryocyte colony-forming units (CFU-Meg) in plasma clot culture stimulated by recombinant human thrombopoietin. Also MKE promoted an increase in hyperploid megakaryocytes, suggesting that the active factor(s) in MKE acts on the mature CFU-Meg and promotes the maturation of megakaryocytes. Gel-filtration high performance liquid chromatography of MKE showed that the promoting factor(s) in MKE was approximately 45 kDa. These results indicate that the factor(s) detected in MKE influence human hematopoiesis in vitro, especially thrombopoiesis.

Animals↗

PubMed2000

Enantioselective synthesis of the key intermediate of the acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor (R-106578) using 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP)-Ru(OAc)2 as a catalyst.

Acidic segment of an acyl-CoA: cholesterol acyltransferase (ACAT) inhibitor, R-106578 was synthesized by enantioselective hydrogenation of the Z-olefine (9-(Z)) using (R)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP)-Ru(OAc)2 as a catalyst in methanol at 100 degrees C, 5 kgf/cm2 of H2 pressure. The requisite Z-olefine was prepared regioselectively via coumarin derivative (5).

Catalysis↗

PubMed2000

ESR study on the antioxidant activity of TAK-218 in biological model membranes.

TAK-218 has a 2,3-dihydrobenzofuran-5-amine (coumaran) structure which resembles alpha-tocopherol, and is a promising candidate as an agent for central nervous system (CNS) trauma and ischemia. The radical scavenging activity of TAK-218 was studied using electron spin resonance (ESR) spectroscopy. TAK-218 exhibited a more potent scavenging activity towards the hydroxyl radical than did the well-known hydroxyl radical scavengers, mannitol and dimethylsulfoxide. Towards the superoxide radical, TAK-218 showed equal potency to glutathione. TAK-218 reacted rapidly with stable radicals, such as galvinoxyl and 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH), and gave the quinone as a two-electron oxidized product in analogy with alpha-tocopherol. To exhibit an excellent antioxidative activity in living systems, the compounds should not only have the intrinsic radical scavenging activity but also good distribution in the biological lipid-bilayer membrane. To examine the antioxidant activity of TAK-218, the inhibition of lipid peroxidation by alpha-tocopherol and TAK-218 in liposomal membranes was studied using an ESR spin-label technique. Both alpha-tocopherol and TAK-218 completely inhibited lipid peroxidation by radicals generated in an aqueous layer using a water-soluble radical initiator, 2,2'-azobis-(2-amidinopropane) hydrochloride (AAPH). At a high incubation temperature (45 degrees C), alpha-tocopherol scavenged radicals more effectively than TAK-218 on the surface of the membrane, while TAK-218 scavenged radicals more effectively in the interior of the membrane. The difference between TAK-218 and alpha-tocopherol for radical scavenging in the membrane system derives from the different distribution pattern of these compounds. TAK-218 can penetrate the membrane freely and can scavenge the radical in the membrane interior. Furthermore, TAK-218 was shown to inhibit lipid peroxidation initiated by a lipid soluble radical initiator, 2,2'-azobis-(2,4-dimethylvaleronitrile) (AMVN), in a membrane more effectively than alpha-tocopherol.

Antioxidants↗

PubMed2000

Endoscopic treatment of vesicoureteral reflux in children with glutaraldehyde cross-linked bovine dermal collagen. Short-term results.

BACKGROUND: Endoscopic treatment using glutaraldehyde cross-linked (GAX) collagen was conducted on 4 children with bilateral primary vesicoureteral reflux (VUR)..... a 1-year-old boy and three 5- to 8-year-old girls $B!D (Ball having a history of repeated hospitalization for fever due to acute pyelonephritis, visiting as pediatric outpatients regularly and receiving antibiotics continuously. By international VUR classification, 4 ureters were grade 3, 2 grade 4, and 2 grade 5. METHODS: After nonallergy to GAX collagen was confirmed intracutaneously, a needle was used through a 9.5 Fr cystoscope channel to puncture bladder mucosa 4 to 5 mm from the affected ureteral orifice at 6 o'clock under general anesthesia; 1.1 to 1.9 ml of GAX collagen was injected immediately below affected orifices. RESULTS: Three months after surgery, voiding cystourethrography showed reflux had disappeared in 6 ureters, for a short-term success rate of 75%. VUR in the Remaining 2 ureters improved from grade 3 to 1 and from grade 5 to 4. No postoperative urinary tract infection occurred and antibiotics were stopped. CONCLUSION: Since GAX collagen is less viscous than Teflon paste, it is easily injected into submucosa, does not form granuloma or migrate to other organs, and is noncarcinogenic. Endoscopic VUR treatment using GAX collagen is indicated when less invasion and shorter hospitalization are considered, although it requires general anesthesia, which itself involves some risk.

Child↗

PubMed2000

Involvement of CD28/CTLA4-B7 costimulatory pathway in the development of lymphadenopathy and splenomegaly in MRL/lpr mice.

MRL/lpr mouse is an established animal model which develops autoimmune diseases including glomerulonephritis, sialoadenitis, hepatitis and inflammatory lung disease. Additionally, it has been reported that lpr strains uniquely accumulate CD3+ CD4- CD8- B220+ (double negative, DN) T cells in lymphoid organs leading to lymphadenopathy and splenomegaly. To investigate the role of CD28/CTLA4-B7 pathway in the development of lymphadenopathy and splenomegaly, MRL/lpr mice were treated with soluble form of CTLA4 molecules, CTLA4IgG, which efficiently blocks this pathway. It was demonstrated that (i) the development of DN T cells was independent of the CD28/CTLA4-B7 pathway, (ii) the CD28/CTLA4-B7 pathway was required for the development of lymphadenopathy and splenomegaly, (iii) the CD28/CTLA4-B7 pathway was important for the accumulation of various cell populations in the lymph node and spleen, (iv) composition of the accumulating cell populations was not altered by CTLA4IgG treatment, and (v) activation of conventional T cells and IL-4 production from conventional T cells were the CD28/CTLA4-B7 pathway dependent. Thus, we concluded that the CD28/CTLA4-B7 pathway was required for the development of full-blown lymphadenopathy and splenomegaly in MRL/lpr mice.

Abatacept↗

PubMed2000

The quality and maturation of bitch oocytes recovered from ovaries by the slicing method.

Oocytes were recovered from bitch ovaries at various stages of the estrous cycle by the slicing method. The proportion of Grade A oocytes (darkly pigmented and surrounded in part, or whole, by dense layers of cumulus cells) were counted. Only Grade A oocytes were cultured in TCM199 supplemented with 5% fetal calf serum for evaluation of meiotic competence. There were no significant differences in the total number of oocytes or the proportion of Grade A oocytes that were recovered from bitches at various stages of the estrous cycle. Only 11% of the oocytes reached metaphase II (MII) at 72 hr after initiation of maturation culture. However, the proportions of oocytes reaching MII did not increase with culturing for up to 120 hr.

Animals↗

PubMed2000

Polymerase chain reaction (PCR) for the detection of herpesvirus in tortoises.

A polymerase chain reaction (PCR)-based method using a herpesvirus consensus primer was assessed for the identification of herpesviral infections in tortoises. A single band of about 230 bp was detected in PCR products from two out of twenty swabs taken from the oral cavity, three out of three paraffin-embedded tissue sections from the liver (two cases) and oral mucosa (one case), and one out of two fresh tissue samples from the oral mucosa. Nucleotide sequencing of these PCR products indicated that the herpesvirus present in these tortoises might belong to the alphaherpesvirinae. PCR using swabs and biopsy tissues was a sensitive and highly specific method for the diagnosis of herpesviral infections in tortoises.

Animals↗

PubMed2000

Screening for proteinuria in Japanese schoolchildren: a new approach.

By governmental mandate, Japanese school children are screened annually for proteinuria, hematuria, and glucosuria to identify children with possible renal disorders. We added urine dipstick tests for albumin and creatinine to the Japanese screening protocol, and used their dipstick results for blood, glucose and protein. The sulfosalicylic acid precipitation test was used to confirm "trace" positive protein dipsticks. The Japanese and our screening protocol have in common the same data for glucosuria and proteinuria. Their scheme has an algorithm for repeat testing of children with abnormal results, and further testing and medical evaluation for those showing persistently abnormal values. Out of the 23,121 students, we found seven with likely nephritis, one with confirmed nephritis, one with nephrotic syndrome, 170 with persistent unexplained hematuria, 19 with persistent unexplained proteinuria, 14 cases of urinary tract infection, and 20 cases of likely diabetes mellitus. We conclude that dipstick testing for albumin, protein, creatinine, glucose and occult blood has significant value in a multilevel testing scheme for identifying children with urinary tract abnormalities or diabetes. The assay of albumin increases the sensitivity of the screening, and dividing the albumin by the creatinine concentration reduces the potential errors arising from concentrated or dilute urines.

Adolescent↗

PubMed2000

Radiation sensitivity of megakaryocyte colony-forming cells in human placental and umbilical cord blood.

The in vitro radiation sensitivity of CFU-Meg isolated from human placental and umbilical cord blood was evaluated in plasma clot cultures stimulated by recombinant human cytokines, including thrombopoietin, the FLT3 ligand (FLT3LG), interleukin-3, interleukin-11 and stem cell factor. The CD34(+) cells were irradiated with X rays at a dose rate of 73 cGy/ min. The megakaryocyte colonies were identified by using an FITC-conjugated antibody to glycoprotein IIbIIIa and were classified into two groups based on colony size: large colonies (immature CFU-Meg) and small colonies (mature CFU-Meg). Treatment with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11 gave exponential radiation survival curves (D(0) for immature CFU-Meg = 56-77 cGy, D(0) for mature CFU-Meg = 86 cGy-1.12 Gy), while marked shoulders were observed on the survival curves for colonies supported by the combination of thrombopoietin, interleukin-3 and stem cell factor (D(0) for immature CFU-Meg = 89- 98 cGy; D(0) for mature CFU-Meg = 1. 25-1.31 Gy). Our results showed that the immature CFU-Meg were more radiosensitive than the mature CFU-Meg and that the combination of cytokines, including thrombopoietin, interleukin-3 and stem cell factor, affected the radiation sensitivity of CFU-Meg to the same extent as with thrombopoietin alone or in combination with FLT3LG and/or interleukin-11.

Antigens, CD34↗

PubMed2000

Spontaneous intracranial hypotension associated with bilateral chronic subdural hematomas--case report.

A 34-year-old female presented with spontaneous intracranial hypotension (SIH) manifesting as severe postural headache and meningism. Magnetic resonance (MR) imaging with gadolinium showed diffuse pachymeningeal enhancement. She developed bilateral chronic subdural hematomas 4 weeks after the onset of the symptoms. MR imaging showed descent of the midline structures of the brain. The bilateral chronic subdural hematomas were surgically drained, with no remarkable pressure. Postoperative MR imaging showed complete resolution of the pachymeningeal enhancement and relevation of the midline structures of the brain. SIH is an uncommon and probably unrecognized condition because of the usually benign course. However, this case emphasizes that SIH is not entirely benign. SIH should be considered if there is no identifiable risk for intracranial hemorrhage, particularly in young patients. Neurosurgical intervention for the treatment of the underlying cerebrospinal fluid leak may be required if SIH persists.

Adult↗

PubMed2000

Immunogenetic background of patients with autoimmune fatigue syndrome.

We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62 kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr = 0.015), and 0.16 (p = 0.0022, Porr = 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS.

Adolescent↗

PubMed2000

Detection of anti-neutrophil cytoplasmic antibodies in MRL/Mp-lpr/lpr mice and analysis of their target antigens.

Anti-neutrophil cytoplasmic antibodies (ANCA) have been widely studied and recognized to be clinically very important for some human diseases including systemic rheumatic diseases. We analyzed ANCA response and their target antigens in MRL/Mp-lpr/lpr (MRL-lpr) mice, an animal model of systemic rheumatic disease. P-ANCA was detected in 57% of the mice. Antibodies to the known P-ANCA target antigens at the same age were examined. Among these, antibodies to high mobility group (HMG) proteins HMG1 and HMG2 were detected in 57% of the mice, 75% of which were also positive for P-ANCA. These anti-HMG1/HMG2 activities were absorbed by preincubation with a mixture of HMG1 and HMG2. In contrast, antibodies to myeloperoxidase and cathepsin G were detected in 14% and 7%, respectively, but these activities were not inhibited by preincubation with corresponding antigens. In addition, the titers of P-ANCA and anti-HMG1/HMG2 antibodies in MRL-lpr mice were significantly correlated with each other. Thus, HMG1 and HMG2 were considered to be significant target antigens of P-ANCA in MRL-lpr mice.

Animals↗