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Biomedical subjects

Y Takei

Publications and source records attributed to Y Takei.

At least 73 records · Page 4Linked to original sources

Cure of Helicobacter pylori infection does not improve symptoms in non-ulcer dyspepsia patients-a double-blind placebo-controlled study.

BACKGROUND: It remains controversial whether the cure of H. pylori infection improves NUD symptoms. AIM: To conduct a double-blind placebo-controlled single centre study with concealed allocation to investigate this question. PATIENTS AND METHODS: Ninety NUD patients with H. pylori infection were randomly assigned to either the treatment group (50 patients) or placebo group (40 patients). The treatment group received omeprazole, amoxycillin, clarithromycin and the placebo group received omeprazole and placebos for 7 days. Symptoms were assessed every week for up to 12 weeks after completion of medication by a symptom questionnaire. Alteration of histological parameters for gastritis was also evaluated. RESULTS: The infection was cured in 41 out of 48 patients in the treatment group and none in the placebo group. There was no significant difference in the mean symptom scores at any assessment point up to 12 weeks between the treatment and placebo groups. Regarding histological parameters, activity and inflammation, not atrophy or intestinal metaplasia, were significantly improved in the treatment group. CONCLUSION: Although histological parameters were significantly improved in the treatment group, there was no significant improvement in symptoms of NUD in the treatment group compared to placebo.

Adult↗

The incidence of reflux oesophagitis after cure of Helicobacter pylori in a Japanese population.

AIM: To investigate the incidence of reflux oesophagitis after antibacterial therapy for Helicobacter pylori infection in our patient population. METHODS: Subjects were 451 H. pylori-infected patients (primary symptom: peptic ulcer disease in 347, nonulcer dyspepsia in 100, and reflux oesophagitis in four): 11 of these patients had reflux oesophagitis on study entry. H. pylori infection was treated by a proton pump inhibitor/amoxycillin-clarithromycin regimen for either 7 or 14 days. Each patient was examined by endoscopy before treatment and more than 6 months after treatment to compare oesophageal findings. In addition, 227 patients were interviewed regarding reflux symptoms, using symptom questionnaires, before and more than 6 months after treatment. RESULTS: Among 440 patients who did not have reflux oesophagitis prior to antibacterial treatment (340 peptic ulcer patients and 100 nonulcer dyspepsia patients), 23 patients whose infection was eradicated developed reflux oesophagitis (5.4%). The 11 patients who had reflux oesophagitis prior to treatment were all successfully cured of infection. Six of these patients showed no change in their oesophagitis, while the condition improved in three and worsened in two. Symptom scores improved in 34 of the 36 patients who reported reflux symptoms. Among 19 patients who showed persistent infection, only one developed reflux oesophagitis (5.2%), while none complained of newly developed symptoms following treatment. CONCLUSIONS: Development of reflux oesophagitis after treatment of H. pylori infection was observed in a Japanese population. However, the incidence of this condition was comparable between those with persistent H. pylori infection and those in whom the infection was eradicated.

Adult↗

Effects of growth factors on aspirin-induced inhibition of wound repair in a rabbit gastric epithelial cell model.

BACKGROUND: Aspirin is known to cause adverse effects, including gastric mucosal injury, and to retard gastric wound healing. Growth factors including hepatocyte growth factor (HGF), epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to play an important role in the repair of gastric mucosal injury. AIM: To employ the cultured gastric epithelial cell model to elucidate the effects of aspirin, as well as several growth factors (HGF, EGF and IGF-I), on gastric wound repair. METHODS: Isolated rabbit gastric epithelial cells (92% mucous cells) were cultured in F-12 medium and formed a complete monolayer cell sheet in 48 h. A wound with a cell-free area of constant size (2 mm2) was then created and the wound repair process was monitored by measuring wound size every 12 h. Proliferating cells were detected by BrdU staining. Effects of aspirin (8 mM), HGF (10 ng/mL), EGF (10 ng/mL) and IGF-I (30 ng/mL) were assessed. RESULTS: Aspirin significantly retarded wound healing, but simultaneous addition of growth factors significantly accelerated wound repair compared with aspirin alone. Growth factors reversed the aspirin-induced inhibition of cell proliferation. CONCLUSION: Growth factors, including HGF, EGF and IGF-I, reversed the aspirin-induced inhibition of wound repair through their cytoprotective effects on gastric epithelial cells.

Animals↗

Role of Kupffer cells and gut-derived endotoxins in alcoholic liver injury.

The hepatotoxic effects of alcohol have been described in detail, but factors responsible for its hepatotoxicity have only partially been characterized. For example, it is known that chronic ethanol ingestion increases hepatotoxicity and produces fatty liver, hepatitis and cirrhosis. However, acute ethanol consumption reduces endotoxin hepatotoxicity. It now appears that Kupffer cells participate in several aspects of these phenomena. Previously, most studies on the effects of alcohol on liver function have focused chiefly on the hepatocyte. Recently, attention has been directed towards the effect of ethanol ingestion on Kupffer cell function, which is stimulated by gut-derived endotoxins (lipopolysaccharides) via mechanisms dependent on increased gut permeability and the possible relationship between Kupffer cells and alcohol-induced liver injury. Here we will review new evidence for the proposal that Kupffer cells and endotoxins play a pivotal role in hepatotoxicity following alcohol exposure, based on studies using the continuous intragastric enteral feeding model developed by Tsukamoto and French and an acute model developed by us.

Ethanol↗

Glycine prevents apoptosis of rat sinusoidal endothelial cells caused by deprivation of vascular endothelial growth factor.

Apoptosis of sinusoidal endothelial cells (SECs) is one of the initial events in the development of ischemia-reperfusion injury of the liver. Glycine has been shown to diminish ischemia-reperfusion injury in the liver and improve graft survival in the rat liver transplantation model. Here, we investigated the effect of glycine on apoptosis of primary cultured rat SECs induced by vascular endothelial growth factor (VEGF) deprivation. Isolated rat SECs were cultured in EBM-2 medium supplemented with 10% fetal bovine serum (FBS) and growth factors including 20 ng/mL VEGF for 3 days. SECs at 3 days of culture showed spindle-like shapes; however, cells started shrinking and detaching from dishes by VEGF deprivation. Apoptosis was detected by terminal deoxynucleotidyl transferase (TdT)-mediated d-uridine triphosphate (dUTP)-biotin nick end labeling (TUNEL) staining in these conditions. Control SECs contained only a few percent of TUNEL-positive cells; however, they started increasing 4 hours after VEGF deprivation, and the percentage of TUNEL-positive cells reached about 50% at 8 hours and almost 100% at 16 hours after VEGF deprivation. Interestingly, this increase in TUNEL-positive cells after VEGF deprivation was prevented significantly when glycine (1-10 mmol/L) was added to the medium, the levels being around 60% of VEGF deprivation without glycine. Furthermore, strychnine (1 micromol/L), a glycine receptor antagonist, inhibited this effect of glycine, suggesting the possible involvement of the glycine receptor/chloride channel in the mechanism. Moreover, Bcl-2 protein levels in SECs were decreased 8 hours after VEGF deprivation, which was prevented almost completely by glycine. It is concluded that glycine prevents apoptosis of primary cultured SECs under VEGF deprivation.

Animals↗

Diagnosis of horizontal enterovirus infections in neonates by nested PCR and direct sequence analysis.

A hospital-acquired outbreak with febrile illness and/or rash occurred in our neonatal special care nursery (SCN) from September 1995 to September 1996. A total of 23 infants developed symptoms. We could not detect the etiological agents by routine virus isolation. In a retrospective study, however, enterovirus RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) from four out of six cerebrospinal fluid (CSF) samples and from two of 12 sera. Thus six out of 16 patients from whom samples were obtained were diagnosed retrospectively as having enterovirus infection. Furthermore, we detected the enterovirus genome from four of 20 serum samples obtained from patients who had other clinical symptoms, and from infants hospitalized without noticeable clinical illness during the same periods. This outbreak was caused by two different enteroviruses, which we assumed were echovirus type 7 (Echo 7) and coxsackievirus B3 (Cox B3), because of the sequence results. We demonstrated the clinical advantage of the analysis of nucleotide sequencing as supportive evidence of transmission.

Base Sequence↗

The Hecht vault performed at the 1995 World Gymnastics Championships: deterministic model and judges' scores.

The aim of this study was to determine the mechanical variables that govern success of the Hecht vault. The participants were 122 male gymnasts from 30 countries performing the vault at the 1995 World Gymnastics Championships. The vaults were filmed using a Photosonics 16-mm motion picture camera operating at 100 Hz. Approximately 80 frames were digitized for each vault analysed. The method of Hay and Reid was used to develop a theoretical model to identify the mechanical and physical variables that determine linear and angular motions of the vault. Correlational analysis was used to establish the strength of the relationship between the causal mechanical variables identified in the model and the judges' scores. Significant correlations (P < 0.005) indicated that the following were important determinants of success: large horizontal and vertical velocities at take-off from the board and the horse; large vertical and angular distances of pre-flight; large vertical impulses of high force and short duration exerted on the horse and the resulting large changes in vertical velocity on the horse; and large horizontal and vertical distances and long times of post-flight. Of the 18 significant variables identified in the present study, the angular distance of pre- and post-flights, the horizontal velocity and angular momentum at take-off from the horse, and the average moment of inertia and duration of post-flight collectively accounted for 57% of the variation in the judges' scores.

Biomechanical Phenomena↗

A phase II study of combined chemoradiotherapy for limited disease-small-cell lung cancer.

A study to evaluate the efficacy of cisplatin, doxorubicin, and etoposide chemotherapy with combined radiotherapy was undertaken in 26 patients with limited disease-small-cell lung cancer. Patients were treated with cisplatin (80 mg/m2) intravenously (i.v.) on day 1, doxorubicin (30 mg/m2) i.v. on day 1, and etoposide (80 mg/m2) i.v. on days 1, 3, and 5, every 4 weeks for four cycles. Thoracic irradiation of 40 Gy in 20 fractions was delivered during 4 weeks to the primary site starting on day 8 of the second cycle of chemotherapy. The objective response rate was 100%. A complete response was observed in 10 patients (38%). The median survival time was 23 months, and the 3-year survival rate was 42%. Seven patients (27%) continued to survive at least 8 years and remain free from disease. Grade III/IV leukopenia was observed in 25 patients (96%). Grade III/IV thrombocytopenia developed in 19 patients (73%). Grade III/IV esophagitis was not seen. Interstitial pneumonitis occurred in two patients. This regimen is effective and has acceptable toxicity for use in the treatment of limited disease-small-cell lung cancer.

Aged↗

Role of the renin-angiotensin system in drinking of seawater-adapted eels Anguilla japonica: a reevaluation.

The role of ANG II, a potent dipsogenic hormone, in copious drinking of seawater eels was examined. SQ-14225 (SQ), an angiotensin-converting enzyme inhibitor, infused intra-arterially at 0.01-1 microgram. kg(-1). min(-1), depressed drinking and arterial blood pressure in a dose-dependent manner. The inhibition was accompanied by a small decrease in plasma ANG II concentration, which became significant at 1 microgram. kg(-1). min(-1). After the infusate was changed back to the vehicle, the depression of drinking and arterial pressure continued for >2 h, although plasma ANG II concentration rebounded above the level before SQ infusion. By contrast, infusion of anti-ANG II serum (0.01-1 microgram. kg(-1). min(-1)) did not suppress drinking and arterial pressure, although plasma ANG II concentration decreased to undetectable levels. Plasma atrial natriuretic peptide and plasma osmolality, which influence drinking rate in eels, did not change during SQ or antiserum infusions. These results suggest that the renin-angiotensin system plays only a minor role in the vigorous drinking observed in seawater eels. The results also suggest that the antidipsogenic and vasodepressor effects of SQ in seawater eels are not due solely to the inhibition of ANG II formation in plasma.

Adaptation, Physiological↗

Bilirubin adsorption therapy and subsequent liver transplantation cured severe bilirubin encephalopathy in a long-term survival patient with Crigler-Najjar disease type I.

Crigler-Najjar disease (CN) type I is characterized by persistent unconjugated hyperbilirubinemia from birth. The male patient here was diagnosed with this disease as a neonate and had been treated by phototherapy. At age 16 he suddenly developed generalized convulsions, followed by impaired cognitive function. The serum level of bilirubin was extremely high (total bilirubin: 41.7 mg/dl) and there were no other detectable causes responsible for the metabolic encephalopathy. He received bilirubin adsorption therapy several times, and the bilirubin encephalopathy improved in response to the fall in the serum level of bilirubin. After this he underwent a successful liver transplantation in Australia, and recovery of his mental faculties was satisfactory. Within the subsequent 3 years epileptic abnormal discharges on the electroencephalogram disappeared. Phototherapy alone can not prevent the rise in the serum level of bilirubin in adolescent or adult patients with CN type I, therefore such patients tend to experience life-threatening bilirubin encephalopathy. To save patients with the acute onset type of bilirubin encephalopathy, sufficient bilirubin adsorption followed by liver transplantation appears to be the most recommended therapeutic approach.

Adsorption↗

Comparative physiology of body fluid regulation in vertebrates with special reference to thirst regulation.

The origin of life took place in the ancient sea where the ionic concentration is thought to have been somewhat lower than that of the present day seas. This may partly explain why most vertebrate species have plasma ionic concentrations roughly one-third of seawater. Exceptions are primitive marine cyclostomes whose plasma is almost identical to seawater, and marine cartilaginous fishes that accumulate urea in plasma to increase osmolarity to a seawater level. The mechanisms for regulation of water and electrolyte balance should have evolved from these animals into those of more advanced ones in which plasma ions are regulated to one-third of seawater irrespective of the habitat. Although most extant terrestrial and aquatic animals maintain similar plasma osmolarity and ionic concentrations, the mechanisms of regulation differ greatly among different groups of animals according to their habitat. An outstanding difference is that while plasma Na(+) concentration is a primary factor of regulation in terrestrial mammals and birds, blood volume is most strictly regulated in aquatic teleost fishes. Consistently, while an increase in plasma osmolarity (cellular dehydration) is a major dipsogenic stimulus for birds and mammals, hypovolemia (extracellular dehydration) is a much stronger stimulus for elicitation of drinking in teleost fishes. Furthermore, fish cells in culture are tolerant to changes in environmental osmolarity compared with mammalian cells, further suggesting a secondary role of plasma osmolarity as a target of regulation in fishes. A secondary role of blood volume for body fluid regulation in birds is further assessed by the fact that volume receptors for thirst, salt gland secretion, and vasotocin secretion are localized in the extravascular, interstitial space in some species of birds. All terrestrial animals including mammals have derived from the fishes in phylogeny, during which the mechanisms for body fluid regulation underwent adaptive evolution in the course of transition from aquatic to terrestrial life. Therefore, much can be learned from comparative studies of body fluid regulation that reveals the diversity and uniformity of the mechanisms. In this review, important comparative studies that may contribute to an understanding of body fluid regulation throughout vertebrate species will be summarized.

Adaptation, Biological↗

Acute and chronic effect of alcohol on Ca2+ channels in hepatic stellate cells.

BACKGROUND: Hepatic stellate cells have been reported to play important roles in the regulation of hepatic microcirculation via cell contraction. Increase in intracellular calcium concentration is required to induce cell contraction. We have already reported the existence of L-type voltage-operated Ca2+ channels (VOCC), such as smooth muscle cells. On the other hand, alcohol has been known to disturb hepatic microcirculation. In this study, we evaluated the effect of acute and chronic treatment of alcohol on VOCC in rat hepatic stellate cells. METHODS: Stellate cells isolated from rats were cultured with or without 100 mM ethanol for up to 14 days. VOCC were detected by the patch clamp technique. Cells cultured for 14 days without ethanol were exposed to ethanol to investigate calcium current during membrane depolarization. alpha-Smooth muscle actin (alpha-SMA) was stained by indirect immunofluorescence. RESULTS: In the control model, VOCC were recognized in cells cultured for more than 7 days. Detection of VOCC increased from 9% on day 7 to 55% on day 14. On the other hand, VOCC in cells treated chronically with 100 mM ethanol appeared earlier than in the control and the incidences were significantly higher than those of the control accompanied with an early activation of cells. In contrast, simultaneous exposure to ethanol during the membrane depolarization inhibited Ca2+ current. CONCLUSIONS: The expression of Ca2+ channels in stellate cells were up-regulated by the chronic treatment of alcohol accompanied with the transformation to myofibroblast-like phenotype. However, alcohol itself inhibited Ca2+ current.

Actins↗

Alcohol enhances lipopolysaccharide-induced increases in nitric oxide production by Kupffer cells via mechanisms dependent on endotoxin.

BACKGROUND: Ethanol causes both tolerance and sensitization of Kupffer cells. Accordingly, this study examines the effect of acute ethanol consumption on nitric oxide (NO) production from Kupffer cells with or without lipopolysaccharide (LPS) treatment. METHODS: Rats were given ethanol (4 g/kg body weight) intragastrically, and Kupffer cells were isolated 2 and 24 hr later. Some rats were treated for 4 days with 150 mg/kg/day of polymyxin B and 450 mg/kg/day of neomycin to prevent growth of intestinal bacteria, the primary source of endotoxin in the gastrointestinal tract. After addition of LPS, NO was measured by the Griess reaction. RESULTS: Two hours after ethanol administration, LPS-induced NO production by Kupffer cells was diminished by 50% but was enhanced 2-fold at 24 hr. Sterilization of the gut with antibiotics blocked this enhancement. CONCLUSIONS: Kupffer cells isolated from rats early after ethanol exhibited tolerance to LPS, whereas sensitization was observed later. It is likely that sensitization to Kupffer cell is caused by gut-derived endotoxin.

Animals↗

[A case of polymyositis presenting pregnancy with acute respiratory failure].

A 33-year-old pregnant woman developed respiratory difficulty with bilateral pleural effusion 31 weeks into gestation. On admission she had an elevated serum level of creatine kinase, but muscle weakness in the extremities was mild. After an immediate and successful Cesarean section, she developed respiratory failure and mechanical ventilation was required. The patient was diagnosed as having polymyositis from the limb muscle biopsy. She was treated with dexamethasone at a dose of 8 mg, methylprednisolone++, 1 g daily for three days, and then prednisolone 60 mg daily. One week later the serum level of creatine kinase was normalized and the patient was weaned from ventilator support. The dose of prednisolone was tapered 10 mg every week and she was discharged two months after delivery without prednisolone. A chest CT scan revealed no interstitial pneumonitis or aspiration pneumonia, so her respiratory failure seemed to be ascribable to polymyositis-related respiratory muscle weakness and pleural effusion. However, severe involvement of respiratory muscles without generalized marked muscle weakness is extremely rare, and pleural complications have usually been described in association with pulmonary parenchymal diseases. During the following two years polymyositis has not recurred in this patient and there have been no data indicative of other overlapping collagen diseases. Reports of polymyositis which occurred during pregnancy are rare, and the pathogenesis and clinical outcome of these patients need to be carefully investigated.

Acute Disease↗

[The role of daunorubicin in induction therapy for adult acute myeloid leukemia].

The relationship between the total dose of daunorubicin (DNR) in induction therapy and the treatment outcome were evaluated based upon individualized doses of DNR during induction therapy for patients with acute myeloid leukemia(AML). Ninety-two previously untreated adult AML patients admitted to our hospital were analyzed for the dose of DNR required for complete remission (CR), the CR rate, disease-free survival (DFS) and overall survival (OS). The induction therapy consisted of DNR (40 mg/m2/d, i.v., from D 1 until the marrow was hypoplastic), Ara-C, prednisolone, and/or 6-thioguanine. Eighty-three out of 92 patients were assessable. Sixty-three patients entered CR (76%), of whom 52 attained CR with the first course of induction therapy. The 10-year DFS and OS rates were 31.2% and 42.3%, respectively. The median total dose of DNR in the induction therapy was 280 mg/m2 (120-480 mg/m2), which was not influenced by initial WBC count, or FAB type. These results indicate that when the dose is linked to the observed tumor response, the optimal dose of DNR in the induction therapy is around 280 mg/m2 (40 mg/m2 x 7 times), which is higher than the conventional dose of 40-60 mg/m2 for 3 days. The higher dose of DNR in the induction therapy for adult AML should be selected when the feasibility of a new drug is evaluated in a randomized trial.

Adolescent↗

[Response to immunoadsorption and steroid therapies in a patient with carcinomatous Lambert-Eaton myasthenia syndrome accompanied by disturbed consciousness].

A 75 year-old man developed gait disturbance and somnolence over a period of three months. Electroencephalography indicated theta slowing and cerebrospinal fluid (CSF) examination showed an increased cell count of 23/microliter and IgG of 7.2 mg/dl. He showed fatigue-inducing muscle weakness and the Harvey-Masland test demonstrated a low M-wave amplitude of 0.6 mV which increased to 3 mV with 50 Hz high-frequency stimulations. The serum titer of P/Q type anti-voltage-gated calcium channel (VGCC) antibody was quite high at 11,901 pmol/L (< 20 pmol/L). The patient was diagnosed as Lambert-Eaton myasthenia syndrome (LEMS) although at first no carcinoma was detected. Immunoadsorption therapy with a phenilalanine absorber column resulted in a reduction in the titer of anti-VGCC antibody to half of the initial concentration, but it increased again within several days. Six repeats of immunoadsorption and concomitant administration of prednisolone at a dose of 40 mg daily succeeded in reducing the anti-VGCC antibody titer of to below 390 pmol/L. The patient's consciousness disturbance and muscle weakness improved simultaneously over the next month and the lumbar puncture and electroencephalography showed normal results. Prednisolone administration was maintained at a dose of 30 mg daily and one year after occurrence of the first symptoms, a small cell lung carcinoma was detected. There was no evidence of limbic encephalitis such as an elevation of anti-Hu antibody in his CSF and serum or abnormal signal intensities in the hippocampal formations on MR imaging. The etiology of his disturbed consciousness remained unclear, but, in the case of LEMS, it could be a manifestation of a paraneoplastic syndrome associated with small-cell lung carcinoma. It is noteworthy that the anti-VGCC antibody titer rose to 1,262 pmol/L 2 months before his tumor was detected and decreased to 286 pmol/L after chemotherapy. P/Q type anti-VGCC antibody could therefore be a useful tumor marker reflecting activity of small-cell carcinoma.

Aged↗

[MALT lymphoma of the larynx].

We describe a 25-year-old Japanese woman with a MALT-type lymphoma of the larynx. She presented with a one-year history of hoarseness and increasing pain in the larynx. A small tumor was found on the left side of the false cord, and was biopsied under laryngoscopy in the department of laryngology. Histological examination showed the presence of centrocyte-like cells infiltrating the submucosa and forming lymphoepithelial lesions. The neoplastic cells were CD20+, CD79a+, and CD5-. Staining for keratin with CAM 5.2 highlighted the infiltrated epithelium. Analysis of DNA extracted from the biopsy specimen showed a clonal immunoglobulin heavy chain gene rearrangement, confirming the histological diagnosis of extranodal marginal zone B-cell lymphoma of the MALT type. To our knowledge, only 6 cases of MALT lymphoma of the larynx have been reported previously. The presence of MALT lymphomas arising at rare sites emphasizes the importance of accurate diagnosis and appropriate clinical management. Patients require careful periodic evaluation in order to time the therapy appropriately, and to avoid overtreatment and complications of therapy, including secondary malignancies.

Adult↗

Partial-liver transplantation to treat familial amyloid polyneuropathy: follow-up of 11 patients.

BACKGROUND: Recently, liver transplantation has been used to treat patients with familial amyloid polyneuropathy (FAP). OBJECTIVE: To describe the clinical course of patients with FAP who received partial-liver transplantation from living donors. DESIGN: Case series. SETTING: University hospital in Matsumoto, Japan. PATIENTS: 11 patients with FAP who underwent partial-liver transplantation. The transthyretin gene abnormality in all 11 patients was the substitution of methionine for valine at position 30. INTERVENTION: Partial liver transplantation from living donors. MEASUREMENTS: Preoperative and follow-up (3 to 64 months) clinical data, including routine laboratory data, nerve conduction velocity tests, and sural nerve histology. RESULTS: All 7 patients who had severe gastrointestinal autonomic disorders or polyneuropathy localized to the lower limbs for less than 4 years showed improvement. Three of 4 patients with polyneuropathy involving both the upper and lower limbs had adverse outcomes, including two deaths. The preoperative duration of their illness was more than 6 years. These 3 patients also had marked decreases in creatinine clearance and nerve conduction velocities and severe loss of myelinated fibers in sural nerves. CONCLUSION: Preoperative clinical severity and duration of illness are associated with outcomes after liver transplantation for FAP.

Adult↗