Biomedical subjects

Masataka Nakamura

Publications and source records attributed to Masataka Nakamura.

At least 19 recordsLinked to original sources

PubMed2006

Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines.

TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-kappaB sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells.

Animals↗

PubMed2006

Prostaglandin D2 plays an essential role in chronic allergic inflammation of the skin via CRTH2 receptor.

PGD(2) plays roles in allergic inflammation via specific receptors, the PGD receptor designated DP and CRTH2 (chemoattractant receptor homologous molecule expressed on Th2 cells). We generated mutant mice carrying a targeted disruption of the CRTH2 gene to investigate the functional roles of CRTH2 in cutaneous inflammatory responses. CRTH2-deficent mice were fertile and grew normally. Ear-swelling responses induced by hapten-specific IgE were less pronounced in mutant mice, giving 35-55% of the responses of normal mice. Similar results were seen in mice treated with a hemopoietic PGD synthase inhibitor, HQL-79, or a CRTH2 antagonist, ramatroban. The reduction in cutaneous responses was associated with decreased infiltration of lymphocytes, eosinophils, and basophils and decreased production of macrophage-derived chemokine and RANTES at inflammatory sites. In models of chronic contact hypersensitivity induced by repeated hapten application, CRTH2 deficiency resulted in a reduction by approximately half of skin responses and low levels (63% of control) of serum IgE production, although in vivo migration of Langerhans cells and dendritic cells to regional lymph nodes was not impaired in CRTH2-deficient mice. In contrast, delayed-type hypersensitivity to SRBC and irritation dermatitis in mutant mice were the same as in wild-type mice. These findings indicate that the PGD(2)-CRTH2 system plays a significant role in chronic allergic skin inflammation. CRTH2 may represent a novel therapeutic target for treatment of human allergic disorders, including atopic dermatitis.

Animals↗

PubMed2006

Oral care reduces incidence of ventilator-associated pneumonia in ICU populations.

OBJECTIVE: To examine whether oral care contributes to preventing ventilator-associated pneumonia (VAP) in ICU patients. DESIGN: Nonrandomized trial with historical controls. SETTING: A medical-surgical ICU in a university hospital. PATIENTS: 1,666 mechanically ventilated patients admitted to the ICU. INTERVENTION: Oral care was provided to 1,252 patients who were admitted to the ICU during period between January 1997 and December 2002 (oral care group), while 414 patients who were admitted to the ICU during period between January 1995 and December 1996 and who did not receive oral care served as historical controls (non-oral care group). MEASUREMENTS AND RESULTS: Incidence of VAP(episodes of pneumonia per 1000 ventilator days) in the oral care group was significantly lower than that in the non-oral care group (3.9 vs 10.4). The relative risk of VAP in the oral care group compared to that in the non-oral care group was 0.37, with an attributable risk of -3.96%. Furthermore, length of stay in ICU before onset of VAP was greater in the oral care than in the non-oral care group (8.5+/-4.6 vs 6.3+/-7.5 days). However, no significant difference was observed in either duration of mechanical ventilation or length of stay between the groups (5.9+/-10.8 vs 6.0+/-8.8 days and 7.5+/-11.5 vs 7.2+/-9.5 days, respectively). Pseudomonoas aeruginosa was the most frequently detected bacteria in both groups. Number of potentially pathogenic bacteria in oral cavity was significantly reduced by single oral care procedure. CONCLUSION: Oral care decreased the incidence of VAP in ICU patients. DESCRIPTOR: Pulmonary nosocomial infection.

Chi-Square Distribution↗

PubMed2006

Analysis of serum granulysin in patients with hematopoietic stem-cell transplantation: its usefulness as a marker of graft-versus-host reaction.

Granulysin is a newly identified CTL/NK cell-related cytotoxic protein, which is secreted in both constitutive and Ca-dependent manner. To evaluate its significance in stem-cell transplantation (SCT), serum granulysin was measured by newly established ELISA method in 26 patients undergoing SCT (21 allogeneic and 5 autologous). In the allogeneic SCT, granulysin was transiently increased in 3 weeks, which was not observed in autologous SCT. In acute GVHD, serum granulysin was markedly increased and correlated with the severity of GVHD. Elevation of granulysin was not necessarily associated with increase of sIL2R or IFN-gamma. In vitro, allospecific T cells released granulysin in an allo-specific manner, and it was correlated with allo-specific cytotoxic activity. These results indicate that increased release of granulysin presents alloreactivity and serum granulysin is useful as a marker of GVHD in SCT.

Antigens, Differentiation, T-Lymphocyte↗

PubMed2006

Chronic pulmonary complications associated with toxic epidermal necrolysis: report of a severe case with anti-Ro/SS-A and a review of the published work.

Patients with toxic epidermal necrolysis (TEN) have been known to have various complications. Though pulmonary complications are often observed, they usually show an acute form; however, chronic complications are quite rare and little is known about either their incidences or clinical manifestations. We herein report a 33-year-old man who presented with chronic pulmonary complications after a recovery from TEN. At the onset of TEN, he had severe respiratory failure and artificial ventilation was instituted. Despite being extubated successfully, respiratory failure reappeared 1 month later. A diagnosis of chronic bronchitis with severe obstructive ventilatory impairment and bronchiectasis was made and he was treated with steroids, bronchodilators and antibiotics, however, he died 1.5 years after the onset of TEN. There have been 13 reported cases of chronic pulmonary complications with TEN or Stevens-Johnson syndrome (SJS) in the English published work. Such cases are usually classified into chronic bronchitis/bronchiolitis with obstructive change (including bronchiolitis obliterans and bronchiolitis obliterans organizing pneumonia), respiratory tract obstruction and bronchiectasis. Approximately 40% of all such patients die while the surviving continue to suffer from these complications because no curative therapy yet exists. As a result, the prognosis seems to be poor. The relationship between TEN and these chronic pulmonary complications remains to be elucidated. Interestingly, our patient was asymptomatically anti-Ro/SS-A positive at the onset of TEN. In addition, eccrine gland involvement and an extremely high level of serum salivary amylase were observed at the onset of TEN, furthermore, Sjögren-like symptoms occurred after recovery from TEN. These findings suggested that the Sjögren-like autoimmune abnormalities induced by anti-Ro/SS-A correlated with the development of chronic pulmonary complications in our patient.

Adult↗

PubMed2006

[A case of autoimmune autonomic neuropathy with marked orthostatic hypotension, decreased salivation, constipation, and Adie pupil].

We report a 68-year-old man with subacute autonomic failure who developed orthostatic hypotension, decreased salivation, constipation, and Adie pupil. There was no evidence of central neurodegeneration, sensory and motor dysfunction. Head-up tilt test showed marked orthostatic hypotension without tachycardia. The patient had a low plasma noradrenaline concentration while supine and a poor noradrenaline response to head-up. Adie pupil responded to 0.125% pilocarpine, establishing denervation hypersensitivity of the parasympathetic nerve. Blood pressure, However, did not show a remarkable response to 0.05-0.2gamma noradrenaline, demonstrating the absence of denervation hypersensitivity of the sympathetic nerve. In contrast to patients with pure autonomic failure, the patient showed normal uptake of I-123-MIBG in the myocardium, indicating intact postganglionic sympathetic innervation. Serologic testing demonstrated circulating antibody to the ganglionic acetylcholine receptor (AchR). Because of subacute clinical course, autonomic symptoms and presence of anti-ganglionic AchR antibody, autoimmune autonomic neuropathy was diagnosed.

Aged↗

PubMed2005

Distinct E2F-mediated transcriptional program regulates p14ARF gene expression.

The tumor suppressor p14(ARF) gene is induced by ectopically expressed E2F, a positive regulator of the cell cycle. The gene is expressed at low levels in normally growing cells in contrast to high levels in varieties of tumors. How p14(ARF) gene is regulated by E2F in normally growing cells and tumor cells remains obscure. Here we show that regulation of p14(ARF) gene by E2F is distinct from that of classical E2F targets. It is directly mediated by E2F through a novel E2F-responsive element that varies from the typical E2F site. The element responds to E2F activity resulting from ectopic E2F1 expression, inactivation of pRb by adenovirus E1a or shRNA, but not to phosphorylation of pRb by serum stimulation or ectopic cyclin D1/cyclin-dependent kinase-4 expression in normal human fibroblasts. The element has activity in various tumor cells with defective pRb, but not in normally growing cells. These results indicate that the distinct regulation constitutes the basis of p14(ARF) function as a tumor suppressor, discriminating abnormal growth signals caused by defects in pRb function from normal growth signals.

Adenovirus E1A Proteins↗

PubMed2005

Influence of toll-like receptor 4, CD14, tumor necrosis factor, and interleukine-10 gene polymorphisms on clinical outcome in Japanese critically ill patients.

The innate recognition of microbial components and subsequent activation of cytokine network are important in the pathophysiology of sepsis. Recently, functional gene polymorphisms in molecules associated with these responses were demonstrated. On the other hand, it has been claimed that there are ethnic differences in genetic polymorphisms. This study investigated toll-like receptor (TLR) 4, CD14, tumor necrosis factor (TNF)-alpha and -beta, and interleukin (IL)-10 gene polymorphisms in 197 Japanese critically ill patients and 214 healthy control subjects to evaluate the influence of these polymorphisms on clinical outcome. No Japanese participant carrying TLR4Asp299Gly or Thr399Ile was detected. No association of CD14-159C/T polymorphisms with genotype frequency or sepsis mortality was observed. Frequency of TNF-alpha-308 GA genotype was significantly higher in the sepsis group than in the control group and TNF-alpha-308GA and IL-10-592CC genotypes were related to poor outcome of sepsis. Ethnic differences in genetic variations are very important issues and the frequencies in this study differ from those previously reported in Caucasians. In conclusion, this study may indicate that TNF-alpha-308G/A and IL-10-592C/A polymorphisms involved in subsequent activation of cytokine network had a larger effect on clinical outcome in patients with sepsis than TLR4Asp299Gly, Thr399Ile, and CD14-159C/T polymorphisms associated with the initial host-microbial interaction.

APACHE↗

PubMed2005

Intracranial pressure monitoring in patients with fulminant hepatic failure treated with plasma exchange and continuous hemodiafiltration.

BACKGROUND/AIMS: To study the influence of our artificial liver support (ALS) on intracranial pressure (ICP) and to evaluate the significance of ICP monitoring in fulminant hepatic failure (FHF) patients treated with ALS. METHODS: ICP was measured in 13 consecutive FHF patients treated with ALS. Maximum value in ICP every day was employed as ICPmax of the day. We analyzed the correlation: (a) between ICPmax and consciousness level; (b) between ICP and colloid osmotic pressure (COP), and (c) between ICP and PaCO2. RESULTS: ICP in 11 patients of 13 was controlled < 20 mm Hg through our ALS. A significant positive correlation between ICPmax and consciousness level was found (p < 0.01). Although there was a significantly negative correlation between ICP and COP (p < 0.001), there was no correlation between ICP and PaCO2. CONCLUSIONS: We conclude that our ALS does not have any adverse effects on ICP and that ICP monitoring is one of the inevitable monitorings in the management of FHF.

Blood Pressure↗

PubMed2005

Identification of two distinct elements mediating activation of telomerase (hTERT) gene expression in association with cell growth in human T cells.

Lymphocytes are exceptional among normal somatic cells in that they express high telomerase activity like germline and malignant cells. We investigated the induction of telomerase in human T cells in association with cell growth. IL-2 significantly augmented the expression of mRNA for human telomerase reverse transcriptase (hTERT), a rate-limiting component of telomerase, in PHA-activated human peripheral blood leukocytes. An isolated 5'-flanking sequence (-3927-+51) of the hTERT gene was examined for its promoter activity in an IL-2-dependent human T cell line Kit 225. Addition of IL-2 into quiescent Kit 225 cells induced activation of the hTERT promoter. Reporter assays with mutant fragments of the hTERT promoter further revealed that IL-2-dependent activation was independently mediated by two elements within the +9-+51 regions. The two elements showed similar kinetics of activation in response to IL-2, which coincided with the G1 to S phase transition of the cell cycle. Interestingly, introduction of mutation in the elements increased background promoter activities in resting T cells in the absence of IL-2. Our results demonstrate that the hTERT promoter may be suppressed by the elements and IL-2 may signal for de-suppression in association with promotion of cell growth. IL-2-dependent activation of the hTERT promoter may be necessary for prevention from senescence induced by extraordinary cell division during immune reactions.

Base Sequence↗

PubMed2005

Functional analysis of natural mutations in two TWIST protein motifs.

The basic helix-loop-helix protein Twist, a transcriptional repressor, is essential for embryogenesis in both invertebrates and vertebrates. Haploinsufficiency of the human TWIST1 gene, which causes the craniosynostosis disorder Saethre-Chotzen syndrome (SCS), is related to failure to repress transcription of CDKN1A (which encodes p21/WAF1/CIP1), promoting osteoblast differentiation. We have examined the functional significance of natural TWIST1 variants present in craniosynostosis patients and in their healthy relatives. Both deletion and duplication variants of the glycine-rich tract Gly5AlaGly5 inhibited E2A (E12/E47)-dependent transcription of CDKN1A to a similar degree as wild-type protein, indicating that the length of this glycine tract is not critical for efficient transcriptional repression. We also evaluated a newly identified heterozygous TWIST1 variant (c.115C>G, encoding p.Arg39Gly), located within a putative nuclear localization signal (NLS), that was present in a child with mild SCS and her clinically unaffected father and grandmother. Unlike wild-type protein, this mutant required cotransfected E12 to localize to the nucleus, indicating that the NLS, including amino acid 39, is essential for nuclear localization; inhibition of E2A-dependent transcription of CDKN1A occurred normally. This analysis further dissects the structure-function relationships of TWIST and corroborates with phenotypic observations of disease expressivity.

Amino Acid Motifs↗

PubMed2005

Evaluation of out-of-hospital cardiopulmonary resuscitation with resuscitative drugs: a prospective comparative study in Japan.

OBJECTIVE: This study aimed at evaluating two emergency medical service systems, one in which emergency life-saving technicians (ELSTs) are allowed to administer epinephrine (adrenaline) to patients with out-of-hospital cardiac arrest and one in which ELSTs are allowed to administer epinephrine, lidocaine, and atropine. METHODS: A modified, prospective community health trial was conducted from April 1 to October 31, 2003. Areas served by physician-manned ambulances, where out-of-hospital cardiopulmonary resuscitation (CPR) was performed with resuscitative drugs (experimental areas), were compared to areas served by ELST-manned ambulances, where resuscitative drugs were not administered outside the hospital (reference areas). The sequence of emergency procedures performed in the experimental areas was divided into three phases. Phase I included administration of epinephrine, which simulated administration of epinephrine by ELSTs. Phase II started with the use of lidocaine or atropine. Phases I and II simulated administration of epinephrine, lidocaine, and atropine by ELSTs. Phase III began with administration of another drug. Outcomes, resuscitation rates and 1-month survival rates were determined, and differences between the two types of areas were analyzed. RESULTS: For non-traumatic cardiac arrest, outcomes through phase II in the experimental areas were significantly better than those in the reference areas. Phase I-only outcomes in the experimental areas were better, but not significantly better, than those in the reference areas. CONCLUSION: Use of resuscitative drugs for non-traumatic prehospital CPR appears to be effective in terms of resuscitation rates and 1-month survival rates.

Aged↗

PubMed2005

Cytokine-related genotypic differences in peak interleukin-6 blood levels of patients with SIRS and septic complications.

BACKGROUND: The aim of the present study was to investigate whether tumor necrosis factor (TNF), interleukin (IL)-1, and IL-6-related genotypic differences affect IL-6 blood levels in patients with systemic inflammatory response syndrome (SIRS) in an intensive care unit (ICU). METHODS: Seven polymorphisms of TNF, IL-1, and IL-6-related polymorphisms were studied with an allele-specific polymerase chain reaction. One hundred and thirteen patients diagnosed with SIRS whose sequential organ failure assessment scores were > or =5 at the time when their daily measured IL-6 blood level peaked during the ICU stay (IL-6 max) were examined. IL-6 max, survival, and septic complications were compared between carriers and non-carriers of less frequent alleles, indicated as allele*2, in each polymorphism. RESULTS: In single nucleotide polymorphism (SNP) at position -238 site of TNF-alpha (TNF-alpha-238*G/A), IL-6-596*G/A, and IL-6-174*C/T, allele*2 frequencies were much lower in the Japanese than in the Caucasian population. IL-6 max was significantly higher in allele*2 carriers of IL-1beta-511*C/T. Associations were found between susceptibility to septic shock and allele*2 carriage for both IL-1beta-511*C/T and TNF-alpha-308*G/A, and also between poor prognosis and allele*2 carriage in both IL-1 receptor antagonist second intron various number of tandem repeats polymorphism (IL-1raRN*1-5) and TNF-alpha-308*G/A. IL-1beta-511*C/T and IL-1raRN*1-5 were in linkage disequilibrium in this study population. CONCLUSIONS: Carriers of less frequent alleles in IL-1-related polymorphisms appear to have significant vulnerability to production of excessive IL-6 blood levels and to deterioration in septic shock.

Adolescent↗

PubMed2005

Management of intra-abdominal hypertension in patients with severe acute pancreatitis with continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter.

To evaluate, with a prospective observational study, whether continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter (PMMA-CHDF) is effective for prevention and treatment of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) on patients with severe acute pancreatitis (SAP). The study was carried out in the general intensive care unit (ICU) of a university hospital. Seventeen consecutive patients with SAP were treated in the intensive care unit and underwent PMMA-CHDF whether or not they had renal failure. Blood level of interleukin (IL)-6, as an indicator of cytokine network activation, and intra-abdominal pressure (IAP) were measured daily to investigate their time-course of changes and the correlation between the two. The blood level of IL-6 was high at 1350+/-1540 pg/mL on admission to the ICU. However, it significantly decreased to 679+/-594 pg/mL 24 h after initiation of PMMA-CHDF (P<0.05), and thereafter decreased rapidly. Mean intra-abdominal pressure (IAP) on admission was high, at 14.6+/-5.3 mm Hg, with an IAP of 20 mm Hg or over in 2 of 17 patients, showing that they had already developed IAH. The IAP was significantly lower (P<0.05) 24 h after initiation of PMMA-CHDF, and subsequently decreased. There was a significant positive correlation between blood level of IL-6 and IAP, suggesting that PMMA-CHDF improved vascular permeability through elimination of cytokines, and that it thereby decreased interstitial edema to lower IAP. Sixteen of the 17 patients were discharged from the hospital in remission from SAP without development of complications. Continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter appears to be effective for prevention and treatment of IAH in patients with SAP through the removal of causative cytokines of hyperpermeability.

Abdomen↗

PubMed2005

FTR1335 is a novel synthetic inhibitor of Candida albicans N-myristoyltransferase with fungicidal activity.

Inhibitors of the fungal enzyme N-myristoyltransferase (Nmt) reduce fungal growth, as this enzyme is essential for viability. We found that a newly synthesized benzothiazole derivative, (1R,3S)-N-{2-[(cyclopeanthylcarbonyl) amino]-benzothiazol-6-yl}-3-[(2-naphthylmethyl) amino] cyclohexanecarboxamide (FTR1335), preferentially inhibited Candida albicans Nmt (CaNmt) in a dose-dependent manner. The 50% inhibitory concentration (IC(50)) for CaNmt was 0.49 nM, which was much lower than the 5400 nM IC(50) for human Nmt (HsNmt1). The mode of CaNmt inhibition was competitive with the substrate peptide and non-competitive with myristoyl-CoA. Moreover, FTR1335 showed strong antifungal activity in vitro, and the minimum fungicidal concentration for C. albicans was 0.78 microM. These results indicate that FTR1335 might represent a novel family of Nmt inhibitors with fungicidal activity.

Acyltransferases↗

PubMed2005

Granulysin induces cell death with nuclear accumulation.

Exogenously added granulysin was reported to kill mammalian target cells. The sites of actions and molecular mechanisms of granulysin in target cell killing, however, are presently unclear. We here examine the effects of granulysin with the target HeLa cells transiently expressed with GFP-fused 9 kDa granulysin. Endogenously expressed GFP-fused granulysin was preferentially localized in the nucleus and induced apoptotic cell death accompanying with phosphatidylserine translocation and nuclear condensation in a caspase-independent manner. These results suggest that granulysin enters the nucleus of target cells and induces apoptosis.

Active Transport, Cell Nucleus↗

PubMed2004

Snail regulates p21(WAF/CIP1) expression in cooperation with E2A and Twist.

Snail, a zinc-finger transcriptional repressor, is essential for mesoderm and neural crest cell formation and epithelial-mesenchymal transition. The basic helix-loop-helix transcription factors E2A and Twist have been linked with Snail during embryonic development. In this study, we examined the role of Snail in cellular differentiation through regulation of p21(WAF/CIP1) expression. A reporter assay with the p21 promoter demonstrated that Snail inhibited expression of p21 induced by E2A. Co-expression of Snail with Twist showed additive inhibitory effects. Deletion mutants of the p21 promoter revealed that sequences between -270 and -264, which formed a complex with unidentified nuclear factor(s), were critical for E2A and Snail function. The E2A-dependent expression of the endogenous p21 gene was also inhibited by Snail.

Basic Helix-Loop-Helix Proteins↗

PubMed2004

Cytokine adsorptive property of various adsorbents in immunoadsorption columns and a newly developed adsorbent: an in vitro study.

BACKGROUND/AIMS: Cytokines play important roles in the pathophysiology of systemic inflammatory response syndrome (SIRS) and sepsis. Therefore, some effective measures to remove cytokines from the bloodstream could be effective in the treatment of SIRS and sepsis. The aim of this study was to evaluate the cytokine adsorptive property of various adsorbents for the purpose of the development of new selective cytokine adsorption columns. METHODS: The cytokine adsorptive property of adsorbent in a CF-X column, which consists of cellulose beads cross-linked with hexamethylene-di-isocyanate, was compared with those of various adsorbents in currently available immunoadsorption columns, such as Immusorba TR, Immusorba PH, Selesorb, and Lixelle, in vitro batchwise test using patients' plasma. A newly developed adsorbent, MPCF-X, which was modified by coating the surface of the adsorbent in CF-X with 2-methacryloyloxyethyl phosphorylcholine (MPC), was also tested for its cytokine adsorptive property. RESULTS: The adsorbent in CF-X showed a significantly higher adsorption rate for TNF-alpha, interleukin (IL)-6 and IL-10 compared with other adsorbents (p < 0.05). Adsorbent in Lixelle showed good affinity to TNF-alpha and IL-8. Especially, the adsorbent in CF-X almost completely removed TNF-alpha, whereas it also had considerable affinity to normal IgG. MPCF-X showed decreased affinity to IgG with considerable adsorptive properties to cytokines. CONCLUSION: Selective cytokine adsorption columns could be developed with improvement of currently available adsorbents. Such a new selective cytokine adsorption column could be clinically applied for the treatment of SIRS/sepsis.

Adsorption↗