Biomedical subjects

T Noguchi

Publications and source records attributed to T Noguchi.

At least 199 records · Page 11Linked to original sources

PubMed2000

[Clinical management of esophageal achalasia].

In this report, we describe the clinical management of esophageal achalasia in Japan. Both balloon dilation and surgical myotomy or myectomy with antireflux procedures are accepted as the standard treatment for esophageal achalasia. In most patients balloon dilation is attempted first. If that is not sufficiently effective, they than undergo surgery. The most important point in treatment is not to repeat the dilation procedure more than twice, because patients who do not respond significantly to the first two dilation procedures are unlikely to improve after subsequent ones. Recently, many physicians and surgeons in Western countries have investigated the effects of botulinum toxin in patients with esophageal achalasia. If the safety of this treatment is confirmed in the near future, it will become a new treatment option for esophageal achalasia.

Catheterization↗

PubMed2000

The influence of mechanical loading on isolated chondrocytes seeded in agarose constructs.

Articular cartilage is subjected to dynamic compressive loading during normal activity which influences chondrocyte metabolism through various mechanotransduction pathways. A well characterised and reproducible model system, involving chondrocytes embedded in agarose gel, has been used to investigate the effects of mechanical compression on chondrocytes, isolated from full depth cartilage or separately from the superficial and deep zone tissue. The role of nitric oxide as a mediator of mechanical-induced effects has also been studied. Chondrocytes were isolated, separately, from full depth, superficial and deep zone cartilage and seeded in 3% agarose constructs. Dynamic compressive strain was applied to the constructs using a range of frequencies (0.3, 1 and 3 Hz). Glycosaminoglycan synthesis, cell proliferation and nitrite production were assessed. In further experiments, constructs were compressed in the presence of 1 mM L-NAME or 10 microM dexamethasone. Glycosaminoglycan synthesis by full depth chondrocytes was affected by compressive strain in a frequency dependent manner. Dynamic strain at all frequencies induced an increase in [3H]-thymidine incorporation. Glycosaminoglycan synthesis by deep zone cells was affected by the strain regimes in a similar fashion to full depth cells, while superficial cells exhibited a similar proliferative response to full depth cells. Dynamic compression inhibited nitrite production, the effect being reversed by L-NAME. Compression induced stimulation of [3H]-TdR incorporation was reversed by L-NAME. These studies demonstrate that glycosaminoglycan synthesis and proliferation are influenced by the dynamic strain regimes in a distinct manner. Indeed the data suggest that these processes occur in different chondrocyte sub-populations. It may be speculated that nitric oxide acts as a mediator of mechanotransduction processes affecting proliferation primarily in the superficial cell sub-population.

Agar↗

PubMed2000

[Gamma-interferon-induced cardiomyopathy during treatment of renal cell carcinoma: a case report].

A 78-year-old woman with renal cell carcinoma and pulmonary metastasis presented with reversible cardiomyopathy induced by gamma(gamma)-interferon. She was treated with gamma-interferon twice a week since November 1996. She presented with severe acute congestive heart failure and gamma-interferon was immediately discontinued in December 1997. Left ventricular fractional shortening was 38% before admission, 12% on admission, and improved to 31% by 40 days after discontinuation of interferon together with administration of diuretics and angiotensin converting enzyme inhibitor. We restarted the same gamma-interferon regimen because it was effective against renal cell carcinoma after 47 days. She has remained well with no significant changes of cardiac function or renal cell carcinoma for almost one year.

Aged↗

PubMed2000

[Reflux esophagitis with hiatal sliding hernia].

Hiatal sliding hernia is often found in aged patient and some of them contribute to the development of reflux esophagitis. We described the etiology of gastroesophageal reflux disease(GERD) briefly and mentioned the relationship between hiatal hernia and reflux esophagitis. The old patients suffers from GERD are accompanying hiatal hernia at the high rate. Our successful results of laparoscopic Nissen's operation were reported shortly. Furthermore, we reviewed the reflux esophagitis after distal gastrectomy as most important complication after surgery. We emphasize that we should not hesitate to perform the surgical treatment to the patients suffering from GERD with hiatal hernia or after gastrectomy because it is safe and bring them the better Q.O.L. after treatment.

Aged↗

PubMed2000

[Hemodynamic effects of propofol as an anesthesia induction agent in hyperthyroidism patients on chronic beta-blocker].

This study was designed to investigate the effect of propofol on the heart rate and blood pressure in the patients on chronic beta-blocker. Seventy two hyperthyroidism patients scheduled for subtotal thyroidectomy were enrolled. Thirty six patients who were on chronic beta-blocker received either propofol (group beta-P) or thiamylal (group beta-T) as an anesthesia induction agent. In control groups, patients who were not on beta-blocker also received either propofol (group C-P) or thiamylal (group C-T). Anesthesia was maintained with nitrous oxide in oxygen and sevoflurane. Heart rate and systolic blood pressures were monitored and recorded before and during anesthesia. Heart rate decreased significantly in group beta-P compared to three other groups through this study. Significant decreases in systolic blood pressure were observed in the groups beta-P and beta-T compared to group C-P. These results suggest that careful attention should be paid to the patients on chronic beta-blocker when propofol was selected as an anesthesia induction agent.

Adrenergic beta-Antagonists↗

PubMed2000

[Effect of olprinone hydrochloride on cerebral blood flow in patients after cardiac surgery].

This study was designed to investigate the effect of olprinone hydrochloride on cerebral blood flow in ten patients after cardiac surgery by transcranial Doppler sonography (TCD). We assessed cerebral blood flow in the middle cerebral artery by transtemporal approach and in the carotid siphon by transorbital approach. We measured the mean blood flow velocity in the left middle cerebral artery (Vmca) and the left carotid siphon (Vlca) and calculated the pulsatility index in the left middle cerebral artery (PImca) and the left carotid siphon (PIlca) using 2 MHz transcranial Doppler ultrasound system (DWL Multidop-P). After baseline measurement, the olprinone hydrochloride loading dosage was increased from 0.15 to 0.3 microgram.kg-1.min-1 every 60 minutes. The mean blood flow velocity was measured at each point. Vmca and Vlca significantly increased, and PImca and PIlca significantly decreased at the infusion rate of 0.3 microgram.kg-1.min-1. There were significant linear correlations between CI and Vmca, CI and Vlca, SVRI and Vmca, as well as SVRI and Vlca. Dose-response relationships were observed in CI, SVRI, Vmca, and Vlca. In conclusion, we demonstrated that olprinone hydrochloride led to an increase of cerebral blood flow in the patients after cardiac surgery.

Aged↗

PubMed2000

An epidemic survey on freshwater puffer poisoning in Bangladesh.

An epidemic investigation was carried out on freshwater puffer poisoning incidents in Bangladesh from April 1988 to May 1996. A lot of information on 10 poisoning cases involving 55 victims was collected through newspapers, interviewing the victims and their families, concerned hospital sources or questionnaires to them. Symptoms of the victims were partly similar to those caused by paralytic shellfish poison (PSP) or tetrodotoxin (TTX). Among them, however, muscle pain, discharge of black urine, and longer recovery time are clearly different. Further, serum creatine phosphokinase (CPK) values were found to be higher (230-450 and 298-430 IU/l) than normal values in two cases. From these different symptoms and high CPK values, it can be predicted/assumed that present freshwater puffer toxin is implicated in not only PSP, but also other toxin(s).

Adult↗

PubMed2000

Matrix metalloproteinase activity is enhanced during corneal wound repair in high glucose condition.

PURPOSE: (1) To investigate the effect of elevated extracellular glucose on migration, proliferation, and the activity of matrix metalloproteinases (MMPs) of SV40-transformed human corneal epithelial cells (HCEC). (2) To examine MMP activity in wounded corneal epithelium in diabetic rats. METHODS: HCEC were cultured in media containing 5.5 mM or 31.2 mM D-glucose, or in a combination of 5.5 mM D-glucose and 25.7 mM D-mannitol on fibronectin/collagen I-coated 48-well plates. After reaching confluence (day 0), cells in the central part of the plate were wounded and the residual cells were cultured for 3 days. Migration and proliferation were evaluated by assessing the increasing amount of area covered by cells, and the day-3 to day-0 ratio of DNA levels, respectively. To determine MMP activity, cells were reacted with synthetic fluorogenic substrates specific to MMPs 1, 2, 3, 7, 9, and MMP activity was determined by a fluorometric kinetic assay. Diabetic rats were induced by streptozotocin injection. Corneal epithelium was scraped from limbus-to-limbus and allowed to heal. Normal rats were treated similarly to serve as controls. Healing epithelium was collected 24 hours later, and gelatin zymography was performed. RESULTS: In the cell culture study, migration in 31.2 mM glucose was significantly slower than that in 5.5 mM, but proliferation in each concentration was similar. The osmotic effect of D-mannitol did not alter migration or proliferation. MMP activity in 31.2 mM was significantly higher than that in 5.5 mM. Zymography revealed enhanced activity of pro and active MMP-9 in healing corneal epithelium in diabetic rats. CONCLUSIONS: MMP activity was enhanced in healing corneal epithelium, both in in vitro and in vivo diabetic models, suggesting its involvement in diabetic keratopathy.

Animals↗

PubMed1999

Transcriptional regulation of fatty acid synthase gene and ATP citrate-lyase gene by Sp1 and Sp3 in rat hepatocytes(1).

When two copies of the sequences spanning -57 to -35 of the fatty acid synthase (FAS) or -64 to -41 of the ATP citrate-lyase (ACL) gene linked to a reporter gene were transfected into primary cultured hepatocytes, the reporter activities significantly increased in response to insulin/glucose treatment. In cotransfection experiments of the FAS(-57/-35) with the Sp1 or Sp3 expression vector, the reporter activities of transcription were suppressed by Sp1 and stimulated by Sp3. In the cotransfection experiments of ACL(-64/-41), the activities were suppressed by Sp1 but were unchanged by Sp3. A similar effect of Sp1 and Sp3 on transcription was seen in mRNA concentrations and enzyme activities of endogenous FAS and ACL. Moreover, the mRNA concentrations and enzyme activities of endogenous acetyl-CoA carboxylase were suppressed by Sp1 and greatly increased by Sp3. Gel mobility super shift assays using antibodies against Sp1 or Sp3 revealed the binding of the transcription factors Sp1 and Sp3 with the GC rich regions located within FAS(-57/-35) and ACL(-64/-41) genes. The formation of DNA-protein complexes was decreased in rats fed a high-carbohydrate diet in comparison with that in fasted rats, but feeding the corn oil diet inhibited this decrease. In Western immunoblotting assay, however, the amount of Sp1 and Sp3 remained unchanged in the dietary conditions. Therefore, the binding of DNA-protein complexes was not due to changes in the amount of Sp1 and Sp3 but to changes in the binding activity, suggesting that these transcription factors may be an important determinant of lipogenic enzyme expression.

ATP Citrate (pro-S)-Lyase↗

PubMed1999

BAS1: A gene regulating brassinosteroid levels and light responsiveness in Arabidopsis.

The Arabidopsis bas1-D mutation suppresses the long hypocotyl phenotype caused by mutations in the photoreceptor phytochrome B (phyB). The adult phenotype of bas1-D phyB-4 double mutants mimics that of brassinosteroid biosynthetic and response mutants. bas1-D phyB-4 has reduced levels of brassinosteroids and accumulates 26-hydroxybrassinolide in feeding experiments. The basis for the mutant phenotype is the enhanced expression of a cytochrome P450 (CYP72B1). bas1-D suppresses a phyB-null allele, but not a phyA-null mutation, and partially suppresses a cryptochrome-null mutation. Seedlings with reduced BAS1 expression are hyperresponsive to brassinosteroids in a light-dependent manner and display reduced sensitivity to light under a variety of conditions. Thus, BAS1 represents one of the control points between multiple photoreceptor systems and brassinosteroid signal transduction.

Arabidopsis↗

PubMed1999

Large-Scale Mapping Observations of the C i (3P1-3P0) and CO (J = 3-2) Lines toward the Orion A Molecular Cloud.

Large-scale mapping observations of the 3P1-3P0 fine-structure transition of atomic carbon (C i, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mount Fuji submillimeter-wave telescope. The observations cover 9 deg2 and include the Orion Nebula M42 and the L1641 dark cloud complex. The C i emission extends over almost the entire region of the Orion A cloud and is surprisingly similar to that of 13CO (J=1-0). The CO (J=3-2) emission shows a more featureless and extended distribution than C i. The C i/CO (J=3-2) integrated intensity ratio shows a spatial gradient running from the north (0.10) to the south (1.2) of the Orion A cloud, which we interpret as a consequence of the temperature gradient. On the other hand, the C i/13CO (J=1-0) intensity ratio shows no systematic gradient. We have found a good correlation between the C i and 13CO (J=1-0) intensities over the Orion A cloud. This result is discussed on the basis of photodissociation region models.

Journal Article↗

PubMed1999

Activation of T cells recognizing an epitope of heat-shock protein 70 can protect against rat adjuvant arthritis.

We have previously reported that CD4+ T cells recognizing a peptide comprising residues 234-252 of the heat shock protein (HSP)70 of Mycobacterium tuberculosis (M.tb) in the context of RT1.B MHC class II molecule emerged in the peritoneal cavity during the course of Listeria monocytogenes infection in rats and suppressed the inflammatory responses against listerial infection via IL-10 production. We report in this work that pretreatment with peptide 234-252 of HSP70 derived from M.tb suppressed the development of adjuvant arthritis (AA) in Lewis rats induced using heat-killed M.tb. T cells from rats pretreated with peptide 234-252 produced a significant amount of IL-10 in response to the epitope. T cells from rats pretreated with the peptide and immunized with M.tb produced the larger amount of IL-10 in response to the peptide, but only a marginal level of IFN-gamma in response to purified protein derivative of M.tb. Administration of anti-IL-10 Ab partly inhibited the suppressive effect of pretreatment with peptide 234-252 on the development of AA. Furthermore, transfer of a T cell line specific for the epitope at the time of AA induction markedly suppressed AA. These findings suggested that T cells recognizing peptide 234-252 may play a regulatory role in inflammation during AA via the production of suppressive cytokines including IL-10.

Amino Acid Sequence↗

PubMed1999

Structure of a histidine ligand in the photosynthetic oxygen-evolving complex as studied by light-induced fourier transform infrared difference spectroscopy.

Fourier transform infrared (FTIR) signals of a histidine side chain were identified in flash-induced S(2)/S(1) difference spectra of the oxygen-evolving complex (OEC) of photosystem II (PS II) using PS II membranes from globally (15)N-labeled spinach and PS II core complexes from Synechocystis cells in which both the imidazole nitrogens of histidine were selectively labeled with (15)N. A negative band at 1113-1114 cm(-1) was downshifted by 7 cm(-1) upon both global (15)N-labeling and selective [(15)N]His labeling, and assigned to the C-N stretching mode of the imidazole ring. This band was unaffected by H-D exchange in the PS II preparations. In addition, several peaks observed at 2500-2850 cm(-1) all downshifted upon global and selective (15)N-labeling. These were ascribed to Fermi resonance peaks on a hydrogen-bonding N-H stretching band of the histidine side chain. FTIR measurements of model compounds of the histidine side chain showed that the C-N stretching band around 1100 cm(-)(1) can be a useful IR marker of the protonation form of the imidazole ring. The band appeared with frequencies in the following order: Npi-protonated (>1100 cm(-1)) > imidazolate > imidazolium > Ntau-protonated (<1095 cm(-1)). The frequency shift upon N-deuteration was occurred in the following order: imidazolium (15-20 cm(-1)) > Ntau-protonated (5-10 cm(-1)) > Npi-protonated approximately imidazolate ( approximately 0 cm(-1)). On the basis of these findings together with the Fermi resonance peaks at >2500 cm(-1) as a marker of N-H hydrogen-bonding, we concluded that the histidine residue in the S(2)/S(1) spectrum is protonated at the Npi site and that this Npi-H is hydrogen bonded. This histidine side chain probably ligated the redox-active Mn ion at the Ntau site, and thus, oxidation of the Mn cluster upon S(2) formation perturbed the histidine vibrations, causing this histidine to appear in the S(2)/S(1) difference spectrum.

Cyanobacteria↗

PubMed1999

A novel apoptotic cascade mediated by CDK4 in rat pheochromocytoma PC12 cells.

Apoptosis induced by serum withdrawal in pheochromocytoma PC12 cells is promoted by overexpression of cyclin-dependent kinase 4 (CDK4). We compared CDK4-promoted apoptosis with that induced by serum withdrawal alone in PC12 cells. Protein synthesis inhibitors did not prevent apoptosis in parental cells, but prevented the promotion of apoptosis by CDK4 overexpression. Nerve growth factor, basic-fibroblast growth factor, and Bcl-2 proteins protected both parental and CDK4-overexpressing cells from apoptosis. However, insulin-like growth factor-I and Bcl-X(L) protein only partially inhibited apoptosis in the CDK4-overexpressing cells. Bcl-2 or Bcl-X(L) had no significant effect on CDK4 kinase activity in both cell lines. These results suggest a novel CDK4-mediated apoptotic cascade which is normally restrained, but which is activated by CDK4 overexpression. This apoptotic cascade should eventually converge with the cascade induced by serum withdrawal in normal PC12 cells. We discuss the interactions among these apoptotic cascades and the points where anti-apoptotic agents act.

Animals↗

PubMed1999

Novel indications for BRCA1 screening using individual clinical and morphological features.

Since there is a lack of common family profile among BRCA1-gene carriers, and since the risk of being a mutation carrier is not limited to women with a family history of breast or ovarian cancer, multivariate statistical analysis using the logistic-regression model was carried out, to discriminate between sporadic cases and BRCA1-breast cancers (BRCA1-BCs), especially when information about the family history of breast/ovarian cancer and ethnicity are irrelevant or unavailable, in order to offer specific medical treatment to this population. We examined 32 BRCA1-BCs selected at cancer genetic clinics and 200 consecutive controls without family history of breast cancer for age at onset and current morphological parameters. Following the multivariate analysis, 3 parameters only, namely, early age at cancer onset [odds ratio (OR) for each year = 1.16; p < 0.0001], estrogen-receptor negativity (OR = 5.7; p = 0.01) and poor differentiation (OR = 5; p = 0.03) were found significant factors for predicting BRCA1-carrier status. The expected impact in BRCA1 screening of our model was estimated using data on 5700 breast-cancer cases from a hospital-based registry. Only 50 and 15% of tumours with early age at onset below 35 years present one or the other 2 discriminant parameters respectively. Consequently, whereas the probability of finding a BRCA1 mutation is rated low (6.2%) when the sole criterion of early onset up to the age of 35 years is used, based on our model, in the sub-group of women with a tumor that is both estrogen-receptor-negative and poorly differentiated the mutation-detection rate is predicted to be above the 10% chance level recommended by the ASCO guidelines. This sub-group of women, representing about 1% of all breast-cancer cases in Western countries, consequently deserves to be tested.

Adult↗

PubMed1999

Bone morphogenetic protein-2 enhances osteoclast formation mediated by interleukin-1alpha through upregulation of osteoclast differentiation factor and cyclooxygenase-2.

Bone morphogenic protein-2 (BMP-2) is a member of the transforming growth factor beta (TGF-beta) superfamily. While BMP-2 is capable of inducing bone formation ectopically, little is known about its role on osteoclastogenesis. In this study, we examined the effect of BMP-2 on osteoclast-like multinucleated cell (OCL) formation in cocultures of osteoblast-like cells and hematopoietic cells of bone marrow origin. BMP-2 alone did not stimulate OCL formation in this culture system; however, it strongly enhanced OCL formation in a dose-dependent fashion in the presence of interleukin-1alpha (IL-1alpha). Western blot analysis showed that a simultaneous addition of BMP-2 and IL-1alpha synergistically enhanced cyclooxygenase-2 (COX-2) expression in osteoblast-like cells. Moreover, Northern blot analysis revealed that the level of osteoclast differentiation factor (ODF) mRNA increased by treatment with BMP-2 and IL-1alpha in osteoblast-like cells. It is noted that BMP-2 alone did cause an increase in the expression of both COX-2 and ODF genes. The stimulatory effect of BMP-2 was abolished by adding nonsteroidal anti-inflammatory drugs, such as indomethacin and a selective COX-2 inhibitor NS-398. Addition of NS-398 inhibited the expression of the ODF gene in osteoblast-like cells treated with BMP-2 and IL-1alpha. These results indicated that the combination of BMP-2 and IL-1alpha stimulated osteoblast-like cells to elevate the expression of both COX-2 and ODF genes, resulting in an enhanced OCL formation. Since BMP-2 alone induced the expression of COX-2 and ODF genes in osteoblast-like cells, it appears to be one of the regulating factors of osteoclastogenesis.

Activins↗

PubMed1999

The gene for an exopolyphosphatase of Pseudomonas aeruginosa.

In Pseudomonas aeriginosa, a gene, ppx, that encodes exopolyphosphatase [exopoly(P)ase; EC 3.6.1.11] of 506 amino acids (56,419 Da) was found downstream of the gene for polyphosphate kinase, ppk. Since ppx is located in the opposite direction of the ppk gene, they do not constitute an operon. The predicted amino acid sequence of PPX is 41% identical with Escherichia coli PPX. The gene product of ppx (paPPX) was overproduced in E. coli, and its activity was evaluated. Orthophosphate (Pi) is released from polyphosphate [poly(P)], the average chain lengths of which are 79 and 750, respectively. The amount of Pi released matched the amount of poly(P) lost. Thus ppx encodes an enzyme that has exopoly(P)ase activity.

Acid Anhydride Hydrolases↗

PubMed1999

Glucose-dependent insulinotropic effects of JTT-608, a novel antidiabetic compound.

The effects of JTT-608 [trans-4-(4-methylcyclohexyl)-4-oxobutyric acid], a novel antidiabetic compound, on insulin secretion were investigated using mouse insulinoma cell line (MIN6 cells) and isolated, perfused rat pancreas. JTT-608 enhanced insulin secretion in MIN6 cells in a dose dependent (10-300 microM) and glucose concentration-dependent (2.8-16.7 mM) manner. Unlike sulphonylureas, JTT-608 minimally stimulated insulin secretion at low glucose concentrations but potently enhanced insulin secretion at high glucose concentrations. In isolated, perfused pancreas of normal rats, JTT-608 (100-300 microM) dose-dependently enhanced insulin secretion in the first and second phases at high glucose concentrations but minimally stimulated insulin secretion at a basal glucose concentration. In isolated, perfused pancreas of neonatally streptozotocin-induced non-insulin-dependent diabetes mellitus rats (nSTZ rats), JTT-608 (200 microM) normalized the first phase and doubled the second phase of insulin secretion. In MIN6 cells, JTT-608 did not inhibit the binding of [3H]glibenclamide to membrane fractions but enhanced K+-ATP channel-independent insulin secretion. These results suggest that JTT-608 enhances insulin secretion in a different manner and via a different mechanism from hypoglycemic sulphonylureas.

Animals↗