Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 37 records · Page 2Linked to original sources

PubMed2004

Helicobacter pylori infection prevents the occurrence of the tolerance phenomenon of histamine H2 receptor antagonists.

BACKGROUND: The attenuated anti-secretory activity of H2 receptor antagonists (H2RA) during continuous administration is referred to as the tolerance phenomenon. However, it is not clarified whether Helicobacter pylori infection affects the occurrence of tolerance to H2RA. It is also not clarified whether the tolerance phenomenon occurs to a new H2RA, lafutidine. AIM: To investigate the occurrence of the tolerance phenomenon in subjects with and without H. pylori infection during the continuous administration of lafutidine and famotidine. SUBJECTS AND METHODS: Subjects were 20 healthy male volunteers (seven H. pylori positive and 13 H. pylori negative cases). All subjects were examined by ambulatory intragastric pH monitoring five times without medication, on the first and 15th day of the administration of 20 mg b.d. famotidine and 10 mg b.d. lafutidine in a cross-over fashion. RESULTS: The tolerance phenomenon was not observed in H. pylori-positive subjects during the 15-day-long administration of both H2RAs. In contrast, the tolerance phenomenon was observed in H. pylori negative subjects, which has been previously reported. CONCLUSIONS: This study demonstrated that H. pylori infection affects the tolerance phenomenon during continuous administration of H2RAs.

Acetamides↗

PubMed2004

Isolation of endophytic diazotroph Pantoea agglomerans and nondiazotroph Enterobacter asburiae from sweetpotato stem in Japan.

AIMS: To isolate and identify diazotrophic endophytes in the stem of Japanese sweetpotato cv. Koganesengan. METHODS AND RESULTS: Surface-sterilized and thinly sliced (1-2 mm) sweetpotato stem samples were incubated in test tubes with semi-solid modified Rennie (MR) medium. The test tubes were assayed for acetylene reduction activity (ARA) 5 days after incubation at 30 degrees C. Twelve isolates were obtained from MR plates inoculated with a loop of semi-solid MR medium from ARA+ tubes. However, ARA test showed that only nine isolates were diazotrophic and three were nondiazotrophic strains. Using the API 20E diagnostic kit, four diazotrophic isolates were identified as strains of Pantoea spp. and five isolates as Klebsiella spp. The nondiazotrophic bacteria were strains of Enterobacter spp. A diazotrophic isolate Pantoea sp. MY1 and nondiazotrophic isolate Enterobacter sp. MY2 were identified to the species level by full sequence analysis of 16S rRNA gene. The results showed that MY1 had 99.2% similarity to Pantoea agglomerans ATCC 27155 and MY2 had 99.5% similarity to Enterobacter asburiae ATCC 35953. CONCLUSION: The stem of sweetpotato cv. Koganesengan was colonized by diazotrophic endophyte P. agglomerans and nondiazotrophic endophyte E. asburiae. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is an essential step toward understanding the ecology and interaction between endophytic bacteria and sweetpotato.

Bacterial Typing Techniques↗

PubMed2004

Dieulafoy's lesion of the esophagus correctly diagnosed and successfully treated by the endoscopic injection of N-butyl-2-cyanoacrylate.

Dieulafoy's lesion is an arterial malformation in the subumucosal layer of the gastrointestinal tract that can cause massive bleeding. The esophagus is not a common location for this lesion. We present here a first report of Dieulafoy's lesion of the esophagus correctly diagnosed and successfully treated by the endoscopic injection of N-butyl-2-cyanoacrylate.

Aged↗

PubMed2004

Expression of RUNX3 protein in human gastric mucosa, intestinal metaplasia and carcinoma.

BACKGROUND: Human runt-related transcription factor gene 3 (RUNX3) is considered as a possible candidate of tumour suppressor gene in human gastric carcinoma. MATERIALS AND METHODS: To investigate the RUNX3 protein expression in human gastric mucosa and carcinoma, we generated a polyclonal antibody, AS251, which recognized amino acid sequences from 251 to 266 of human RUNX3. The AS251 antibody was immunoreactive with only RUNX3 protein, but not with RUNX1 and RUNX2. The AS251-antibody was available for Western blotting and immunohistochemistry using paraffin-embedded specimens. RESULTS: Western-blot analysis revealed that three (MKN-1, -7 and -45) of six human gastric carcinoma cell lines variably expressed RUNX3 protein, consistent with the expression pattern of RUNX3 mRNA reported previously by Li et al. (Cell 2002;109:113-24). Immunohistochemistry disclosed RUNX3 protein in most chief cells and a few gastrin-containing G cells in normal mucosa, but not in intestinal metaplasia and carcinoma cells. CONCLUSIONS: These data suggest that RUNX3 may play a physiologic role in chief cells and G cells in gastric mucosa, and that suppression of RUNX3 expression in intestinal metaplasia and carcinoma of human stomach may be implicated in gastric carcinogenesis.

Amino Acid Sequence↗

PubMed2004

Which types of non-bleeding visible vessels in gastric peptic ulcers should be treated by endoscopic hemostasis?

BACKGROUND AND AIMS: Because non-bleeding visible vessels (NBVV) of gastric peptic ulcers have the potential to re-bleed, endoscopic hemostatic treatment may be necessary during the first emergency endoscopy. However, not all NBVV re-bleed, and endoscopic hemostasis sometimes causes fatal side-effects. Therefore, we have evaluated the risk of re-bleeding from various NBVV in gastric peptic ulcers to determine which types should be treated by endoscopy to prevent re-bleeding. METHODS: A total of 227 NBVV in 202 patients with gastric peptic ulcers that were endoscopically followed without endoscopic hemostatic procedures were classified by the following factors: vessel color, form, location of the NBVV in the ulcer crater, and location of the ulcer in the stomach. The re-bleeding rate was then analyzed for each type of NBVV. RESULTS: Significantly high rates of re-bleeding were observed in cases with white, protruded and peripheral NBVV. In particular, white NBVV located in the peripheral zone of the ulcer crater were frequent re-bleeding sources. The location of the ulcer in the stomach was not a statistically significant factor in determining re-bleeding rates. CONCLUSION: We found that white, protruded and peripherally located NBVV in gastric ulcers have a higher chance of re-bleeding if preventive endoscopic hemostatic procedures are not performed.

Chi-Square Distribution↗

PubMed2004

Evidence that angiotensin II enhances apomorphine-induced jaw movements via AT1 receptors in the ventrolateral striatum: studies by magnet-sensing system in freely moving rats.

The role of angiotensin AT(1) receptors in the ventrolateral striatum in modulating apomorphine-induced jaw movements was studied using a magnet-sensing system combined with an intracerebral drug microinjection technique in freely moving rats. Bilateral injections of angiotensin II (1 and 2 micro g/0.2 micro l in each side) into the ventrolateral striatum, which alone did not significantly elicit jaw movements, dose-dependently enhanced apomorphine (1 mg/kg i.v.)-induced repetitive jaw movements. The enhancement of apomorphine-induced jaw movements by angiotensin II (2 micro g) was dose-dependently antagonized by the angiotensin AT(1) receptor antagonist losartan (15 and 30 mg/kg i.p.), given 3 h before, while losartan (30 mg/kg i.p.) alone did not significantly affect the apomorphine (1 mg/kg)-induced jaw movements. These results indicate that angiotensin II enhances apomorphine-induced jaw movements via stimulation of angiotensin AT(1) receptors located in the ventrolateral striatum.

Angiotensin II↗

PubMed2004

[Repair of thoracic and thoracoabdominal aortic aneurisms by the use of hypothermic circulatory arrest].

From 1993 to 2003, repair of thoracic and thoracoabdominal aortic aneurysms using hypothermic circulatory arrest via the left thoracotomy was performed in 115 patients at our hospital. Ninety-one of them were elective cases and 24 of them were emergent cases. Hospital mortality rate was 3.3% in elective cases and 12.5% in emergent cases. Over all hospital mortality rate was 5.2%. Ischemic spinal cord injury was occurred in 2 patients (1.7%). Both of them needed total replacement of thoracoabodominal aorta by the graft. In the near future, Adamkiewicz artery may be detected by the imaging technology preoperatively and we expect the repair of thoracoabdominal aortic aneurysm may become safer operation avoiding spinal cord injury. Hypothermic circulatory arrest is a relatively safe and reliable method for the repair of thoracic and thoracoabdominal aortic aneurysms.

Adult↗

PubMed2004

A selective cyclooxygenase-2 inhibitor, NS398, inhibits cell growth and induces cell cycle arrest in the G2/M phase in human esophageal squamous cell carcinoma cells.

It is well known that cyclooxygenase (COX) -2 is expressed in a variety of human malignant solid tumors, associated with tumor angiogenesis, cell proliferation and inhibition of apoptosis. Here, we examined the effect of NS398, a selective COX-2 inhibitor, on two human esophageal squamous cell carcinoma (SCC) cell lines, TE-1 and TE-12. Western blot analysis confirmed the expression of COX-2 in TE-12, but not in TE-1. Treatment with 100microM NS398 suppressed the cell viability in TE-12 (48.6% of control) after 48 hours, in contrast to showing no effects in TE-1. The apoptotic index was extremely low in both cell lines after the treatment. NS398 clearly increased the number of cells in the G2/M phase and decreased the cells in the G1 and S phases in TE-12, but not TE-1. A pre-G1 fraction was not noted in either cell line. Moreover, TE-12 cells showed a decrease in the expression levels of cyclin B1 and an increase in p27Kip1. These findings suggest that NS398 inhibits cell growth and induces G2/M arrest in human SCC cells expressing COX-2.

Apoptosis↗

PubMed2004

[Adult mitral and tricuspid valve regurgitation due to patent ductus arteriosus combined with atrial fibrillation; report of a case].

73-year-old female with mitral and tricuspid valve regurgitation due to patent ductus arteriosus (PDA) with atrial fibrillation (AF) was reported. The patient was admitted for dyspnea on effort. She was diagnosed as mitral and tricuspid valve regurgitation due to PDA with AF by transthoracic echocardiography. She underwent mitral valve plasty (quadrangular resection of prolapsed posterior leaflet and annuloplasty with Duran flexible-ring 25 mm), tricuspid annuloplasty (De Vega annuloplasty), PDA direct closure and radiofrequency modified maze procedure. Postoperative echocardiogram showed good mitral and tricuspid valve function. He recovered well after the operation and was discharged in stable sinus rhythm.

Aged↗

PubMed2003

Measurement of dopamine receptor-mediated jaw movements by a magnet-sensing system in freely moving rats.

This study tested a system for monitoring jaw movements in freely moving rats. A Hall-effect transducer was fixed to the skull in order to sense voltage changes induced by variations in the position of a magnet fixed to the mandible. By measuring dopamine receptor-mediated jaw movements, this system produces data comparable to that obtained using a light-sensitive transducer system in anesthetized rats, while also measuring the vertical component of jaw movements in freely moving rats. In combination with conventional visual observation, this system may provide a useful tool for assessing movements of the orofacial region during spontaneous and drug-evoked behavior.

Animals↗

PubMed2003

Cytokine-induced inflammatory liver injuries.

IL-18 is a pleiotropic cytokine and is produced by various types of cells including activated macrophages, particularly Kupffer cells. IL-18 has potential to activate inflammatory responses through induction of IFN-gamma production in collaboration with IL-12. Somewhat paradoxically, IL-18 also has the capacity to induce allergic responses via induction of IL-4 production by T helper cells and to activate mast cells and basophils to release atopic effector molecules such as histamine. Indeed, IL-18 is involved in inflammatory tissue injuries, such as Crohn's disease and atherosclerosis, and also in hyper IgE and atopic dermatitis. IL-18 is particularly important for induction of experimental liver diseases. Endotoxin-induced liver injury or Fas ligand-induced hepatitis is caused by endogenous IL-18 in mice. Moreover, patients with liver diseases such as fulminant hepatitis, liver cirrhosis due to hepatitis virus infection and primary biliary cirrhosis show elevation of serum levels of IL-18, that correlates with the corresponding disease severity. Therefore, endogenous IL-18 plays a major role in induction of some types of liver injuries in mice and human. NKT cells that express both T cell receptor and NK cell marker are abundant in the liver of mice and human. Recent studies have revealed that NKT cells participate in some types of liver injuries, such as concanavalin A-induced T cell-mediated hepatitis and malaria hepatitis. In this review article, we focus on IL-18-involving liver damages and NKT-cell-mediated liver injuries.

Animals↗

PubMed2003

[Ventricular pseudo-false aneurysm after myocardial infarction; report of a case].

A 72-year-old man was admitted to our hospital with chest discomfort and syncope. The echocardiography showed the left ventricular aneurysm. The coronary arteriography revealed a complete occlusion at distal portion of the right coronary artery and anterior aneurysm of the left ventricle was demonstrated. We diagnosed that it was false aneurysm because of communicating with the left ventricle through a small orifice. Surgical repair was carried out after resection of the aneurysm of the left ventricle. The postoperative course was uneventful and discharged on the 33rd day after surgery. Pseudo-false ventricular aneurysm of the left ventricle was diagnosed by histological examination.

Aneurysm, False↗

PubMed2002

Safety and efficacy of glucagon as a premedication for upper gastrointestinal endoscopy--a comparative study with butyl scopolamine bromide.

BACKGROUND: Glucagon inhibits digestive motility and is used for endoscopic premedication; however, its effect on cardiopulmonary function during endoscopy has not yet been fully investigated. AIM: To clarify the efficacy and safety of glucagon compared with butyl scopolamine bromide as upper gastrointestinal endoscopy premedication. METHODS: Two hundred and forty consecutive patients over 40 years of age, referred for upper gastrointestinal endoscopy, without any complications, were studied. These patients were randomly premedicated with butyl scopolamine bromide (SC group) or glucagon (G group). Time course changes in blood pressure, arterial oxygen saturation, heart rate and the number of retching episodes during endoscopy were examined. The efficacy of glucose tablets after upper gastrointestinal endoscopy to prevent hypoglycaemia caused by glucagon was evaluated. Cardiopulmonary parameters were also examined in 77 complicated patients with glucagon premedication (GC group). RESULTS: A continuous increase in heart rate during upper gastrointestinal endoscopy was observed in the SC group, but not in the G and GC groups. Blood pressure, arterial oxygen saturation and number of retching episodes were not different between the groups. Hypoglycaemia-related symptoms were frequent in the G group without glucose tablets, but were prevented by the administration of glucose. CONCLUSIONS: Glucagon has a weaker effect on cardiopulmonary function during upper gastrointestinal endoscopy than butyl scopolamine bromide. Glucose administration prevents hypoglycaemia-related symptoms caused by glucagon.

Aged↗

PubMed2002

Nizatidine and cisapride enhance salivary secretion in humans.

BACKGROUND: Salivation plays an important role in the defence of the oesophageal mucosa against gastric acidic reflux and can be evoked by cholinergic stimulation. Both nizatidine and cisapride have been reported to increase acetylcholine concentrations in the cholinergic system. AIM: To investigate the effect of nizatidine and cisapride on salivary secretion, salivary epidermal growth factor and bicarbonate output. METHODS: The salivary volume and concentration of salivary epidermal growth factor and bicarbonate were measured after the administration of nizatidine (150 mg), famotidine (20 mg) and cisapride (5 mg) in 30 male healthy volunteers. RESULTS: Basal and stimulated salivary secretions were found to be increased after the administration of nizatidine and cisapride. In contrast, salivary secretion was not increased by famotidine. Although epidermal growth factor content was not augmented, nizatidine and cisapride administration also increased the bicarbonate output in mastication-stimulated saliva. CONCLUSIONS: Increased salivary secretion and bicarbonate output induced by nizatidine may be useful for the treatment of patients with gastro-oesophageal reflux disease.

Adult↗

PubMed2001

Flexibility and nucleation in sickle hemoglobin.

We have studied the self-assembly of Hemoglobin C-Harlem (HbC-Harlem), a double mutant of hemoglobin that possesses the beta6 Glu-->Val mutation of sickle hemoglobin (HbS) plus beta73 Asp-->Asn. By electron microscopy we find it forms crystals, rather than the wrapped multistranded fibers seen in HbS. Fourier transforms of the crystals yield unit cell parameters indistinguishable from crystals of HbS. Differential interference contrast (DIC) microscopy and birefringence also show crystal formation rather than the polymers or domains seen for HbS, while the growth patterns showed radiating crystal structures rather than simple linear crystalline forms. The solubility of the assembly was measured using a photolytic micromethod over a temperature range of 17-31 degrees C in 0.15 M phosphate buffer and found to be essentially the same as that of fibers of HbS. The assembly kinetics were observed by photolysis of the carbon monoxide derivative, and the mass of assembled hemoglobin was found to grow exponentially, with onset times that were stochastically distributed for small volumes. The stochastic onset of assembly showed strong concentration dependence, similar to but slightly greater than that seen in sickle hemoglobin nucleation. These observations suggest that like HbS, HbC-Harlem assembly proceeds by a homogeneous nucleation process, followed by heterogeneous nucleation. However, relative to HbS, both homogeneous and heterogeneous nucleation are suppressed by almost 11 orders of magnitude. The slowness of nucleation can be reconciled with the similarity of the solubility to HbS by an increase in contact energy coupled with a decrease in vibrational entropy recovered on assembly. This also explains the linearity of the double-strands, and agrees with the chemical nature of the structural replacement.

Anemia, Sickle Cell↗

PubMed2001

Consequence of beta 16 and beta 112 replacements on the kinetics of hemoglobin assembly.

The rates of alpha/beta monomer combination of four beta(A) variants (beta 112C --> S, beta 112C --> D, beta 112C --> T, and beta 112C --> V) in the presence and absence of beta 16G --> D (beta(J)) were measured in an attempt to assess the consequences of amino acid substitution at both a surface (beta 16) and an alpha(1)beta(1) interface (beta 112) residue on oxyhemoglobin assembly. Rates of alpha/beta monomer combination determined spectrally in 0.1 M Tris-HCl, 0.1 M NaCl, 1 mM EDTA, pH 7.4, at 21.5 degrees C differed by over 40-fold (22 +/- 2.0 to 0.49 +/- 0.1 x 10(5) M(-1) s(-1)), and were in the order: HbA beta 112S = HbJ beta 16D, beta 112S > HbA beta 112D = HbJ beta 16D, beta 112D > HbA > Hb J > HbA beta 112T = HbJ beta 16D, beta 112T > HbJ beta 16D, beta 112V > HbA beta 112V. This extensive kinetic investigation of single/double amino acid-substituted recombinant hemoglobin molecules, in conjunction with molecular modeling studies, has allowed examination of an array of unique alpha/beta subunit interactions and assembly processes.

Amino Acid Substitution↗

PubMed2001

Plasmodium berghei infection in mice induces liver injury by an IL-12- and toll-like receptor/myeloid differentiation factor 88-dependent mechanism.

Malaria, caused by infection with Plasmodium spp., is a life cycle-specific disease that includes liver injury at the erythrocyte stage of the parasite. In this study, we have investigated the mechanisms underlying Plasmodium berghei-induced liver injury, which is characterized by the presence of apoptotic and necrotic hepatocytes and dense infiltration of lymphocytes. Although both IL-12 and IL-18 serum levels were elevated after infection, IL-12-deficient, but not IL-18-deficient, mice were resistant to liver injury induced by P. berghei. Neither elevation of serum IL-12 levels nor liver injury was observed in mice deficient in myeloid differentiation factor 88 (MyD88), an adaptor molecule shared by Toll-like receptors (TLRs). These results demonstrated a requirement of the TLR-MyD88 pathway for induction of IL-12 production during P. berghei infection. Hepatic lymphocytes from P. berghei-infected wild-type mice lysed hepatocytes from both uninfected and infected mice. The hepatocytotoxic action of these cells was blocked by a perforin inhibitor but not by a neutralizing anti-Fas ligand Ab and was up-regulated by IL-12. Surprisingly, these cells killed hepatocytes in an MHC-unrestricted manner. However, CD1d-deficient mice that lack CD1d-restricted NK T cells, were susceptible to liver injury induced by P. berghei. Collectively, our results indicate that the liver injury induced by P. berghei infection of mice induces activation of the TLR-MyD88 signaling pathway which results in IL-12 production and activation of the perforin-dependent cytotoxic activities of MHC-unrestricted hepatic lymphocytes.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Involvement of nuclear transcription factor Sp1 in regulating glucose transporter-1 gene expression during rat trophoblast differentiation.

Glucose transporter-1 (GLUT1) is important in placental glucose transport. However, the mechanism of regulation of placental GLUT1 expression remains to be elucidated. We show here that the level of GLUT1 protein in rat choriocarcinoma cells (Rcho-1) decreased during differentiation. To analyze the regulatory mechanism of rat GLUT1 (rGLUT1) gene expression, we transfected rGLUT1 promoter-chloramphenicol acetyltransferase constructs into Rcho-1 cells. Deletion analysis of the rGLUT1 promoter suggested that the region -76/-53 bp was essential for basal transcriptional activity. Electrophoretic mobility shift assays showed that transcription factors Sp1 and Sp3 bound two GC boxes in the region -99/-33 bp of the rGLUT1 promoter. Mutation analysis of the Sp1 binding sites revealed that the promoter-proximal site located between -76 and -53 bp was essential for basal rGLUT1 promoter activity. Furthermore, the decreased level of GLUT1 may result from a decreased level of Sp1 during differentiation. These findings suggest that Sp1 is involved in the regulation of rGLUT1 gene expression during rat trophoblast differentiation.

Animals↗