Biomedical subjects

K Murakami

Publications and source records attributed to K Murakami.

At least 19 recordsLinked to original sources

PubMed2006

Association between dietary fiber, water and magnesium intake and functional constipation among young Japanese women.

OBJECTIVE: Most research on constipation has focused on dietary fiber intake. Here, we examined the intake of water and magnesium, nutrients possibly associated with constipation, as well as that of dietary fiber in relation to constipation. DESIGN: Cross-sectional study. SUBJECTS: A total of 3835 female Japanese dietetic students aged 18-20 years from 53 institutions in Japan. METHODS: Dietary intake was estimated with a validated, self-administered diet history questionnaire. Functional constipation was defined using the Rome I criteria. RESULTS: The prevalence of functional constipation was 26.2%. Neither dietary fiber intake (mean=6.4 g/4186 kJ) nor intakes of total water and water from fluids were associated with constipation. Conversely, low intake of water from foods was associated with an increasing prevalence of constipation. In comparison with women in the first (lowest) quintile, the multivariate adjusted odds ratio (OR) (95% confidence interval (CI)) for women in the second, third, fourth, and fifth quintiles were 0.72 (0.57, 0.90), 0.78 (0.62, 0.98), 0.71 (0.56, 0.89), and 0.77 (0.61, 0.97), respectively (P for trend=0.04). Additionally, low magnesium intake was associated with increasing prevalence of constipation. Compared with women in the first quintile, the multivariate adjusted OR (95% CI) for women in the second, third, fourth and fifth quintiles were 0.70 (0.56, 0.88), 0.75 (0.60, 0.95), 0.73 (0.58, 0.92) and 0.79 (0.63, 0.996), respectively (P for trend=0.09). CONCLUSIONS: Low intakes of water from foods and magnesium are independently associated with an increasing prevalence of functional constipation among a population whose dietary fiber intake is relatively low.

Adolescent↗

PubMed2006

Nerve injury induces the expression of EXT2, a glycosyltransferase required for heparan sulfate synthesis.

Heparan sulfate proteoglycans, which bear long chains of heparan sulfate glycosaminoglycan, play significant roles during embryogenesis, including the formation of the CNS. However, their involvement in nerve regeneration has not yet been clarified. Here, we found that the mRNA expression of EXT2, one of the crucial enzymes for heparan sulfate-glycosaminoglycan synthesis, was markedly up-regulated in injured hypoglossal motor neurons after axotomy. In addition, immunohistochemical staining with an antibody specific for heparan sulfate-glycosaminoglycan chains demonstrated increased expression of heparan sulfate-glycosaminoglycan chains in the injured nucleus. Furthermore, the mRNA expressions of glypican-1 and syndecan-1, which are both well-known heparan sulfate proteoglycans, were prominently up-regulated in injured motor neurons. These results suggest that the biosynthesis of heparan sulfate chains promoted by EXT2 is activated in injured motor neurons, and that glypican-1 and syndecan-1 are potent candidates for heparan sulfate proteoglycans involved in peripheral nerve regeneration.

Activating Transcription Factor 3↗

PubMed2006

A newly modified SCG10 promoter and Cre/loxP-mediated gene amplification system achieve highly specific neuronal expression in animal brains.

We designed a new promoter that drives transgene expression in an exclusively neuron-specific manner. The promoter of superior cervical ganglion10 (SCG10), expressed in neurons, was further modified to enhance its neuron specificity and activity by changing its length and fusing a multiple neuronal restrictive silencer element (NRSE) to its upstream or downstream regions. The promoter, which contained 2 kb original promoter length and two extra NRSEs in its downstream region, eventually exhibited remarkable neuron specificity as well as strong activity. To further amplify the promoter activity, the promoter was introduced into a Cre recombinase (Cre)-expressing adenovirus, and subsequent combination with Cre-inducible enhanced green fluorescence protein (EGFP)-expressing adenovirus vector, which has much stronger general promoter, resulted in a remarkably strong gene expression exclusively in neuronal cells of mixed cultures and in an animal model. This system is also applicable to astrocyte-specific expression; for instance, by changing the Cre promoter cassette to an astrocyte-specific promoter. The present relatively compact promoter combined with Cre/loxP system could be useful for a wide range of transgene experiments in vivo as well as for clinical applications.

3T3 Cells↗

PubMed2006

Dietary intake in relation to self-reported constipation among Japanese women aged 18-20 years.

OBJECTIVE: Information on modifiable lifestyle factors associated with constipation is limited, especially among non-Western populations. We examined associations between dietary intake and self-reported constipation in young Japanese women. DESIGN: Cross-sectional study. SUBJECTS: A total of 1,705 female Japanese dietetic students aged 18-20 years and free of current disease and current dietary counseling. METHODS: Dietary intake was estimated over a 1-month period with a validated, self-administered, diet history questionnaire, and lifestyle variables including self-reported constipation were assessed by a second questionnaire designed for this survey. RESULTS: A total of 436 women (26%) reported themselves to be 'constipated'. A multivariate odds ratio (OR) for women in the highest quartile of rice intake was 0.47 (95% confidence interval (CI): 0.33, 0.68) compared with the lowest. Additionally, women in the highest category of coffee intake had a multivariate OR of 0.67 (0.47, 0.94) compared with women in the lowest. Conversely, women in the highest quartile of confectionery intake had a multivariate OR of 1.54 (1.12, 2.13) compared with women in the lowest. Moreover, a multivariate OR for constipation for women in the highest quartile of Japanese and Chinese tea intake was 1.49 (1.09, 2.05) compared with women in the lowest. Neither total dietary fiber intake nor other lifestyle factors examined were associated with constipation. CONCLUSIONS: The consumption of rice and coffee was inversely associated with and that of confectioneries and Japanese and Chinese tea was positively associated with a prevalence of self-reported constipation.

Adolescent↗

PubMed2006

Catalytically inactive lipoprotein lipase overexpression increases insulin sensitivity in mice.

Abnormalities in lipoprotein lipase (LPL) function contribute to the development of hypertriglyceridemia, one of the characteristic disorders observed in the metabolic syndrome. In addition to the hydrolyzing activity of triglycerides, LPL modulates various cellular functions via its binding ability to the cell surface. Here we show the effects of catalytically inactive LPL overexpression on high-fat diet (HFD)-induced decreased systemic insulin sensitivity in mice. The binding capacity of catalytically inactive G188E-LPL to C2C12 skeletal muscle cells was not significantly different from that of wild type LPL. Insulin-stimulated IRS-1 phosphorylation and glucose uptake were increased by addition of wild type or mutant LPL in C2C12 cells. After 10 weeks' of HFD feeding, mice had significantly higher blood glucose levels than chow-fed mice in insulin tolerance tests. The blood glucose levels after insulin injection was significantly decreased in mutated LPL-overexpressing mice (G188E mice), as well as in wild type LPL-overexpressing mice (WT mice). Overexpression of catalytically inactive LPL, as well as wild type LPL, improved impaired insulin sensitivity in mice. These results show that decreased expression of LPL possibly causes the insulin resistance, in addition to hypertriglyceridemia, in metabolic syndrome.

Animals↗

PubMed2005

Dual axonal terminations from the retrosplenial and visual association cortices in the laterodorsal thalamic nucleus of the rat.

Light and electron microscopic tracing studies were conducted to assess the synaptic organization in the laterodorsal thalamic nucleus (LD) of the rat and the laminar origins of corticothalamic terminals from the retrosplenial and visual association cortices to LD. A survey of the general ultrastructure of LD revealed at least three types of presynaptic terminals identified on the basis of size, synaptic vesicle morphology, and synaptic membrane specializations: (1) small axon terminals with round synaptic vesicles (SR), which accounted for the majority of terminal profiles and made asymmetric synaptic contacts predominantly with small dendritic shafts and spines; (2) large axon terminals with round synaptic vesicles (LR), which formed asymmetric synaptic contacts mainly with large dendritic shafts; and (3) small to medium-size axon terminals with pleomorphic synaptic vesicles (SMP), which symmetrically synapsed with a wide range of postsynaptic structures from cell bodies to small dendrites. Synaptic glomeruli were identified, whereas no presynaptic dendrites were found. To characterize and identify corticothalamic terminals arising from the retrosplenial and visual association cortices that project to LD, wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was injected into these cortices. Axons anterogradely labeled with WGA-HRP ended in both SR and LR terminals. On the other hand, dextran-tetramethylrhodamine injected into LD as a retrograde fluorescent tracer labeled large pyramidal cells of layer V as well as small round or multiform cells of layer VI in the retrosplenial and visual association cortices. These findings provide the possibility that corticothalamic terminations from cortical neurons in layer V end as LR terminals, while those from neurons in layer VI end as SR boutons.

Animals↗

PubMed2005

CXCL12 and CXCR4 expression by human gingival fibroblasts in periodontal disease.

CXCL12 is a CXC chemokine that is related to lymphocyte infiltration and angiogenesis in inflammatory sites such as arthritis. However, the expression and roles of CXCL12 in periodontal disease are uncertain. The aim of this study was to assess the expression of CXCL12 and its receptor, CXCR4, in periodontal tissue and to investigate the properties of CXCL12 and CXCR4 expression by human gingival fibroblasts (HGF). RT-PCR analysis revealed that CXCL12 and CXCR4 mRNA were expressed in both normal gingival tissues and periodontal diseased tissues. Immunohistochemistry disclosed that CXCL12 was expressed and CXCR4 positive cells were found in both normal and periodontal diseased gingival tissues. Our in vitro experiments elucidated that HGF constitutively produced CXCL12, and the levels were enhanced by stimulation with tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), regulated upon activation normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein 3(alpha) (MIP-3(alpha)). On the other hand, heat killed Porphyromonas gingivalis (P. gingivalis) and P. gingivalis LPS reduced the CXCL12 production by HGF. Flow cytometry analysis clarified that CXCR4 was highly expressed on HGF, and CXCR4 expression was abrogated by TNF-alpha, IFN-gamma and P. gingivalis LPS. Moreover, CXCL12 induced vascular endothelial growth factor (VEGF) production by HGF. Our results demonstrated that CXCL12 might be related to CXCR4+ cells infiltration and angiogenesis both in normal periodontal tissues and periodontal diseased tissue. P. gingivalis, a known periodontal pathogen, inhibits the production of CXCL12 and the expression of CXCR4 by HGF. This fact means that P. gingivalis may inhibit CXCR4+ cells infiltration and neovascularization in periodontal tissue and escape from the immune response.

Cells, Cultured↗

PubMed2005

Polymorphisms in PTCH1 affect the risk of ameloblastoma.

Ameloblastoma is the most common odontogenic tumor, but the genetic nature of the changes in the tumor cells has been unclear. Mutations of CTNNB1 or PTCH1 are observed in many human tumors. Both CTNNB1 and PTCH1 are important in tooth development and are expressed in ameloblastoma. The aim of this study was to investigate whether genetic alterations of CTNNB1 and PTCH1 are present in ameloblastoma. We investigated 14 cases of ameloblastoma. The polymorphisms found in the ameloblastoma patients were further examined in a subsequent case-control study. We found a CTNNB1 mutation in one case of plexiform-type ameloblastoma. CGG triplet repeat-number polymorphism (CGG7/CGG8) in the 5'-untranslated region of PTCH1 was observed. The proportion of CGG8 alleles was significantly higher in the ameloblastoma group. The results of this study indicate a possible relationship between the CGG8 allele in PTCH1 and the risk for ameloblastoma.

Adult↗

PubMed2005

An autopsied case of neuromyelitis optica with a large cavitary cerebral lesion.

We report a case of neuromyelitis optica (NMO) with a large cerebral lesion. The patient had an episode of fever and consciousness disturbance with a tumefactive frontal white matter lesion at age 43, and then repeated bilateral optic neuritis and transverse myelitis until she died at age 63. Histopathological examinations revealed that marked tissue destruction, cavities and inflammatory changes typical of NMO were seen in the cerebrum as well as the optic nerves and spinal cord. This is the first autopsied case of NMO with a tumefactive cerebral lesion that later became cavitary.

Fatal Outcome↗

PubMed2005

[Comparison of postoperative lung function between segmentectomy and lobectomy in patients with lung carcinoma].

BACKGROUND: To determine any potential advantages of segmentectomy, we compared preoperative and postoperative lung function of patients who underwent segmentectomy with those in patients who underwent lobectomy. PATIENTS & METHODS: Between September 2001 and November 2003, preoperative and postoperative lung function, including DLco, was assessed in 43 patients with primary lung carcinoma. Of these 43 patients, 33 underwent single lobectomy (group L) and 10 underwent segmentectomy (group S). Both groups were examined for differences in lung volume through VC and FEV1.0 data, and all postoperative examinations were performed at 2 weeks after surgery. Changes in DLco (deltaDLco), VC (deltaVC) and FEV1.0 (deltaFEV1.0) were calculated and we compared the data for group L with those of group S. RESULTS: Mean values for deltaVC, deltaFEV1.0 and deltaDLco in group L were 31.8 +/- 9.3, 29.6 +/- 10.9 and 27.2 +/- 14.0%, respectively, while these values in group S were 22.9 +/- 7.9, 20.1 +/- 9.6 and 13.9 +/- 11.6%, respectively. deltaVC, deltaFEV1.0 and deltaDLco were significantly smaller in group S than in group L (p < 0.01, p < 0.05 and p < 0.05, respectively). CONCLUSION: Segmentectomy was superior to lobectomy with regard to preservation of lung function in the early postoperative period.

Aged↗

PubMed2004

Distribution and superinfection of bovine leukemia virus genotypes in Japan.

A study to investigate the types and distribution of bovine leukemia virus (BLV) was conducted on about eight hundred cattle drawn from 53 farms found in 16 prefectures in Japan. Agar gel immunodiffusion (AGID) tests of serum samples and nested-PCR to detect BLV provirus, in peripheral blood leukocytes were performed. To identify genotypes, restriction fragment length polymorphism (RFLP) was performed with a PCR-amplified 444 bp fragment of the env gene using endonucleases. Three genotypes (1, 3, and 5) were dominant in Japan, and were found in 48.3%, 32.7%, and 16.9% of PCR positive cattle, respectively. Of the cattle infected with genotype 1, 84.7% were strongly positive in the AGID test. Similarly, in cattle with genotype 3, 78.9% were strongly positive. However, only 59.1% of cattle with genotype 5 were strong positive. Three cattle showed unusual RFLP patterns and they were found to be infected with more than one genotype. These results suggest that some BLV infected cattle can not induce effective immune reactions and suffer from superinfection by BLV in the field.

Animals↗

PubMed2004

A new diagnostic test for VLCAD deficiency using immunohistochemistry.

BACKGROUND: Muscle pathology is often unhelpful in elucidating the specific underlying abnormality in patients with metabolic myopathy with rhabdomyolysis, including very-long chain acyl-CoA dehydrogenase (VLCAD) deficiency. Biochemical analyses require large amounts of biopsy samples for each enzyme assay. OBJECTIVE: To develop a more efficient diagnostic method for VLCAD deficiency. METHODS: The authors performed immunohistochemical analysis using an antibody to VLCAD on muscles from 344 patients (226 men and 118 women) without a specific diagnosis who had at least one of the following symptoms: myoglobinuria, high CK level, muscle pain, muscle stiffness, sudden infant death syndrome, and Reye-like syndrome. RESULTS: Immunoreactivity to VLCAD was absent or markedly reduced in 13 patients. Biochemical analyses confirmed that all these patients had low enzymatic activity and reduced amount of protein. They all had the myopathic phenotype. The authors identified homozygous or compound heterozygous mutations in all of them. All recombinant proteins had reduced enzymatic activity except for 128G>A (G43D) and 796C>G (P266A) mutants, indicating that they are neutral polymorphisms. CONCLUSIONS: The new screening method for the detection of VLCAD deficiency using an immunohistochemical technique identified 13 new Japanese patients with VLCAD deficiency.

Acyl-CoA Dehydrogenase, Long-Chain↗

PubMed2004

Identification of temperature-sensitive dnaD mutants of Staphylococcus aureus that are defective in chromosomal DNA replication.

The DnaD protein in Gram-positive bacteria is thought to be essential for the initiation step in DNA replication. In the present study, we characterized two Staphylococcus aureus mutants whose temperature-sensitive growth phenotype could be complemented by a plasmid carrying the dnaD gene. These mutants each had a single amino acid substitution in the DnaD protein and showed decreased DNA synthesis at restrictive temperature. Analyses of the origin to terminus ratio by Southern blotting, and of origin numbers per cell by flow cytometry, revealed that, at the restrictive temperature, one mutant continued ongoing DNA replication but failed to initiate DNA replication. The other mutant, in contrast, could not complete ongoing DNA replication and proceeded to degrade the chromosome. However, if protein synthesis was inhibited, the second mutant could complete DNA replication. These results suggest that DnaD protein is necessary not only for the initiation step, but also to avoid replication fork blockage. Moreover, both mutants were sensitive to mitomycin C, a drug that induces DNA damage, suggesting that the DnaD protein is also involved in DNA repair.

Amino Acid Substitution↗

PubMed2004

Synovial chondromatosis of the temporomandibular joint: clinical and immunohistopathological considerations.

A histopathological study of 30 cases of synovial osteochondromatosis found that the process followed a temporal sequence characterised by three phases: (I) active intrasynovial disease only; (II) transitional lesions with both active intrasynovial proliferation and free loose bodies; and (III) many free osteochondral bodies with no demonstrable intrasynovial disease [J. Bone Joint Surg. 59 (1977) 792]. We present five cases of synovial chondromatosis of the temporpmandibular joint (TMJ) which we studied by immunohistochemical methods of for transforming growth factor beta (TGFbeta) and tenascin.

Adult↗

PubMed2004

Saline-assisted endoscopic resection of rectal carcinoids: cap aspiration method versus simple snare resection.

BACKGROUND AND STUDY AIMS: Complete resection of small carcinoid tumors of the rectum is difficult during endoscopic polypectomy, because these tumors are often located in the submucosal layer of the rectal wall. To completely remove these tumors, we have used aspiration lumpectomy. In this study, we evaluated its clinical usefulness in comparison with strip biopsy. PATIENTS AND METHODS: We performed strip biopsy (December 1996 through March 2000) or aspiration lumpectomy (April 2000 through February 2003) in a consecutive series of patients with rectal carcinoid tumor. Eight carcinoid tumors in eight patients were resected by strip biopsy, and eight tumors in eight patients were resected by aspiration lumpectomy. RESULTS: The rate of complete removal of carcinoid tumors with aspiration lumpectomy (100 %) was significantly higher (P < 0.05) than that with strip biopsy (37.5 %). CONCLUSIONS: Endoscopic resection with aspiration lumpectomy is a useful and safe method for resection of small carcinoid tumors of the rectum.

Carcinoid Tumor↗

PubMed2004

CTLA-4 blockade inhibits induction of Helicobacter pylori-associated gastritis in mice.

The balance between Th1 and Th2 response determines the outcome of Helicobacter pylori infection. Interferon (IFN)-gamma plays an inductive role in gastric inflammation, whereas interleukin (IL)-4 counterbalances Th1 response and suppresses the development of gastritis. Th cell response is regulated by co-stimulatory factors. A co-stimulatory molecule, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), plays an inhibitory role in IL-2-dependent cell growth and mediates an optimal inhibitory signal to Th1 and Th2 cells. We administered anti-CTLA-4 monoclonal antibody (MoAb), which blocks CTLA-4 signalling, to examine the relative role for this signalling during maturation of Th1 and Th2 cells in H. pylori infection in mice. Mice treated by anti-CTLA-4 MoAb within the first week of infection showed an inhibition of gastric inflammation, accompanied by an increasing ratio of H. pylori-specific IgG1/IgG2a in serum following infection. Furthermore, the treatment resulted in the higher ratio of IL-4/IFN-gamma by splenocytes in response to H. pylori antigen at 6 weeks after infection, compared with untreated mice. These results suggest that the predominance of Th2 response by CTLA-4 blockade leads to an inhibition of the development of gastric inflammation. CTLA-4 signalling could contribute to the regulation of Th subsets and the development of gastric inflammation in H. pylori infection.

Animals↗

PubMed2004

[Perforating mediastinal mature teratoma associated with acute cardiac tamponade; report of a case].

We report a case of the mediastinal teratoma associated with acute cardiac tamponade followed by emergency operation. This tumor causes a variety of complications, but reports of acute cardiac tamponade have been rare. 20-year-old male admitted into our hospital with complaint of the chest pain, who was diagnosed with mediastinal tumor. She was admitted due to sudden fever up, and 5 days after admission, the complaint of severe epigastralgia and abdominal swelling were occurred. A chest X-ray film and chest computed tomography (CT) revealed cardiac tamponade. We carried out emergency surgical pericardial drainage and extirpation of the tumor. The tumor was composed of cystic part involving of dark green fluid macroscopically. The amylase level in this fluid was 42 U/l. We observed a small hole on the pericardial sac beside the base of ascending aorta. The amylase level in pericardial effusion was 19 U/l. Histopathological diagnosis was mature teratoma perforating into pericardiac sac, which included skin, bronchus and pancreatic tissue. We concluded that the progress of the tumor and the mechanical inflammation were major cause of perforation of the tumor into the pericardial sac, and autodigestion by enzyme from pancreas was minor cause of perforation.

Acute Disease↗

PubMed2003

Autoimmune hemolytic anemia as a first manifestation of primary effusion lymphoma.

A 55-year-old man developing transfusion-dependant anemia was diagnosed with autoimmune hemolytic anemia (AIHA). Although he received prednisolone (PSL) (daily 60 mg), his hemoglobin level continued to decrease. After 3 weeks of treatment, he presented with a distension of the abdomen. Cytological examination of ascitic fluid revealed large, immunoblastic lymphocytes with plasmacytoid features and abundant IgM chains on the cellular surface; this was diagnosed as primary effusion lymphoma (PEL). Administration of CHOP (cyclophosphamide, Adriamycin, vincristine, and PSL) chemotherapy elicited regression of ascites as well as recovery of hemoglobin level. We hypothesize that PEL cells generated antibodies against red blood cells, resulting in AIHA resistance to PSL.

Anemia, Hemolytic, Autoimmune↗