Biomedical subjects

Y Ohta

Publications and source records attributed to Y Ohta.

At least 145 records · Page 8Linked to original sources

PubMed2000

Changes in epidermal growth factor receptors in olfactory epithelium associated with aging.

To clarify the mechanisms of age-related changes in the olfactory epithelium, we investigated age-related changes in epidermal growth factor receptors (EGFRs) in the epithelium. We examined 3 mice at each of the following stages: embryonal (embryonic days 14 and 16), neonatal (postnatal days 1 and 7), adult (postnatal weeks 5 and 12), and aged (postnatal years 1.5 to 2). The olfactory epithelium of each mouse was stained with sheep anti-human EGFR polyclonal IgG by an immunohistochemical method. The EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages. They were identified only in the basal layer of the olfactory epithelium at adult and aged stages, and the number of regions in which EGFRs were identified in the basal layer of the olfactory epithelium decreased in aged mice compared to adult mice. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with resultant atrophy of the olfactory epithelium.

Aging↗

PubMed2000

Proliferation markers, proliferating cell nuclear antigen, Ki67, 5-bromo-2'-deoxyuridine, and cyclin D1 in mouse olfactory epithelium.

We immunohistochemically identified proliferating cells in the olfactory epithelium of mice, using an anti-proliferating cell nuclear antigen (PCNA) antibody, an anti-Ki67 antibody, an anti-5-bromo-2'-deoxyuridine (BrdU) antibody, and an anti-cyclin D antibody. Positive cells stained by the 4 antibodies were identified mainly in the basal layer. The mean numbers of positive cells stained by the 4 antibodies in 500 olfactory epithelium cells from each animal were as follows: PCNA-positive cells 42, Ki67-positive cells 23, BrdU-positive cells 13.7, and cyclin D1-positive cells 9.2. PCNA may be detected in both proliferating and resting cells. Ki67 is an intranuclear antigen expressed in proliferating, but not resting, cells. Anti-BrdU antibodies might stain proliferating cells only following the S-phase, but not the G1-phase. Cyclin D1 is a protein that works during the G1-phase of the cell cycle. When we stain proliferating cells using proliferating cell markers, it is important to consider the cell cycle phases during which each marker stains.

Animals↗

PubMed2000

Inhibition of in vitro fertilization of mouse gametes by sulfated sialic acid polymers.

The effect of sialic acid (N-acetyl neuraminic acid), sialic acid dimer, sialic acid polymers (colominic acid) and sulfated colominic acid on the activity of hyaluronidase, on the dispersion of cumulus cells by mouse sperm and on in vitro mouse fertilization (sperm penetration of zona pellucida) were evaluated. Bovine testicular hyaluronidase activity was significantly inhibited by colominic acid and sulfated colominic acid, but not by sialic acid and its dimer. The dispersion of cumulus cells from eggs by mouse sperm was also inhibited by colominic acid and sulfated colominic acid. In vitro fertilization of mouse gametes was inhibited by sulfated colominic acid. The IC50 value of sulfated colominic acid-induced inhibition of fertilization was 0.3 mg/ml (ca. 0.9 mM). The value changed from 0.9 mM for cumulus-surrounded egg to 1.5 mM for cumulus free-egg. On the other hand, colominic acid showed little or no inhibitory effect on mouse in vitro fertilization at 0.5 mg/ml (ca. 1.6 mM). This antifertility activity by sulfated colominic acid did not appear to be due to an effect on sperm motility or on the oocytes. These results suggest that (1) the cumulus cells surrounding the eggs were dispersed by sperm hyaluronidase, (2) hyaluronidase was inhibited by colominic acid and by sulfated colominic acid, (3) sulfated colominic acid inhibits sperm penetration of zona pellucida by the inhibition of hyaluronidase and/or some enzymes required for mouse gametes fertilization.

Animals↗

PubMed2000

Purification and characterization of dibenzothiophene sulfone monooxygenase and FMN-dependent NADH oxidoreductase from the thermophilic bacterium Paenibacillus sp. strain A11-2.

A dibenzothiophene (DBT) sulfone monooxygenase (TdsA), which catalyses the oxidative CS bond cleavage of DBT sulfone to produce 2-(2-hydroxyphenyl)benzenesulfinate (HPBS) was purified from the thermophilic DBT desulfurizing bacterium Paenibacillus sp. strain A11-2 by multistep chromatography. The molecular mass of the purified enzyme was determined to be 120 kDa by gel filtration and the subunit molecular mass was calculated to be 48 kDa by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) indicating a dimeric structure. The N-terminal amino acid sequence of the purified TdsA was determined to be MRQMHLAGFFAAGNTHH, which revealed no significant similarity to any other known amino acid sequences. The purified TdsA absolutely required an oxidoreductase for its activity. This oxidoreductase (TdsD) was also purified to homogeneity, and its molecular size was calculated to be 50 kDa and 25 kDa by gel filtration and SDS-PAGE, respectively. TdsD was completely FMN-dependent, and FAD could not act as a cofactor. The N-terminal amino acid sequence of the purified TdsD was determined to be TSQTAEQSIAPIVAQYRHPEQPISALFVNR, which showed significant similarity to kinesin-like protein (44% identity). The optimal temperatures for the activity of TdsA and TdsD were 45 degrees C and 55 degrees C, respectively. Both enzymes showed optimal activity at pH 5.5. TdsA was slightly inhibited by sulfate, but not by 2-hydroxybiphenyl (2-HBP), which is another end product of DBT. TdsA showed higher activity toward bulkier substrates than its mesophilic counterpart, DszA. These properties suggest the applicability of biodesulfurization to the processing of actual petroleum fractions.

Journal Article↗

PubMed2000

Screening for proteinuria in Japanese schoolchildren: a new approach.

By governmental mandate, Japanese school children are screened annually for proteinuria, hematuria, and glucosuria to identify children with possible renal disorders. We added urine dipstick tests for albumin and creatinine to the Japanese screening protocol, and used their dipstick results for blood, glucose and protein. The sulfosalicylic acid precipitation test was used to confirm "trace" positive protein dipsticks. The Japanese and our screening protocol have in common the same data for glucosuria and proteinuria. Their scheme has an algorithm for repeat testing of children with abnormal results, and further testing and medical evaluation for those showing persistently abnormal values. Out of the 23,121 students, we found seven with likely nephritis, one with confirmed nephritis, one with nephrotic syndrome, 170 with persistent unexplained hematuria, 19 with persistent unexplained proteinuria, 14 cases of urinary tract infection, and 20 cases of likely diabetes mellitus. We conclude that dipstick testing for albumin, protein, creatinine, glucose and occult blood has significant value in a multilevel testing scheme for identifying children with urinary tract abnormalities or diabetes. The assay of albumin increases the sensitivity of the screening, and dividing the albumin by the creatinine concentration reduces the potential errors arising from concentrated or dilute urines.

Adolescent↗

PubMed2000

Effectiveness of the fold plication method in lung volume reduction surgery.

OBJECT: The fold plication method is a new operative procedure for lung volume reduction surgery whereby the target area is obliterated by plicating the folded tissue using a knifeless stapler, without the use of bovine pericardium. The effectiveness of this new method was evaluated in patients with advanced pulmonary emphysema. PATIENTS AND METHODS: Two weeks before and 6 months after surgery, pulmonary function, static lung compliance, maximal esophageal pressure, maximal inspiratory and expiratory mouth pressures, 6-min walking distance and the Borg scale were determined in twenty consecutive patients who underwent video-assisted thoracoscopic unilateral surgery. RESULTS: There was an increase in forced expiratory volume in one second (31%), forced vital capacity, peak expiratory flow rate and maximal voluntary ventilation, and a decrease in functional residual capacity (-16%) measured by plethysmograph. Static lung compliance decreased, and maximal esophageal pressure, and maximal inspiratory and expiratory mouth pressures increased. The 6-min walking distance increased (20%) and the Borg scale decreased (5.9 to 3.5). CONCLUSION: The results compare favorably with those obtained with other methods. Thus, the fold plication method could be considered an alternative procedure for lung volume reduction surgery.

Aged↗

PubMed2000

Applicability of Hyland's Living with Asthma Questionnaire for Japanese asthmatic patients.

OBJECTIVE: To assess the applicability of Hyland's Living with Asthma Questionnaire (LWAQ, 1991), one of the international health-related quality of life scales, for Japanese asthmatic patients with reference to its reproducibility and validity. SUBJECTS AND METHODS: The LWAQ was given to randomly selected asthmatic patients on two occasions separated by a 12-week interval. RESULTS: The mean scale score in the first study (n=304) was 1.83 (range, 1.14-2.77) and logarithmic values of the scores approached normal distribution. The scale scores in the first and second (n=158) studies were well correlated (r=0.81), however, the mean score decreased (0.08) significantly. The questions were further separated into 11 domains. The sex-domain was notable for a low response rate (68%), and scale scores in the sleep-, colds- and sex-domains in the first study varied considerably from those of the other domains. Frequency distributions of scores in the five constructs (Hyland 1996) were not normal and, with the exception of the colds construct, the relations among the remaining four constructs were similar to those previously reported (Hyland 1996). CONCLUSION: Analysis using the mean scale score, domain and construct in the LWAQ is applicable to Japanese asthmatic patients.

Asthma↗

PubMed2000

Genetic analysis of Japanese patients with persistent hyperinsulinemic hypoglycemia of infancy: nucleotide-binding fold-2 mutation impairs cooperative binding of adenine nucleotides to sulfonylurea receptor 1.

To elucidate the genetic etiology of persistent hyperinsulinemic hypoglycemia of infancy (PHHI) in the Japanese population, we conducted a polymerase chain reaction-single-strand conformation polymorphism analysis of the sulfonylurea receptor 1 (SUR1) and Kir6.2 genes in 17 Japanese PHHI patients, including a pair of siblings from a consanguineous family. We also analyzed the glutamate dehydrogenase gene for the exons encoding an allosteric regulatory domain of the enzyme. In the SUR1 gene, we identified one frameshift (I446fsdelT) and two missense (R1420C, R1436Q) mutations. None of these mutations were found in control Japanese subjects. Siblings homozygous for the R1420C mutation had a mild form, whereas two patients heterozygous for the I446fsdelT and R1436Q mutations, respectively, exhibited a severe form of PHHI. Functional consequences of these mutations on K(ATP) function were evaluated using 86Rb+ efflux studies in COS-7 cells. SUR1-446fsdelT and SUR1-1436Q did not form a functional K(ATP). Western blot analysis after transient expression in COS-7 cells revealed the expression of SUR1-1436Q protein to be markedly reduced, suggesting SUR1-1436Q to be unstable in these cells. K(ATP)(SUR1-1420C) showed reduced responses to metabolic inhibition by oligomycin and 2-deoxyglucose. K(ATP) channels are under complex regulation by intracellular ATP and ADP. ATP both inhibits and activates these channels. The inhibition is probably mediated through direct ATP interaction with a pore-forming subunit Kir6.2, whereas the activation is likely to be through a regulatory subunit SUR1. There is a cooperative regulation of ATP and ADP binding to SUR1, and this cooperativity may be involved in regulating the K(ATP) channel. In SUR1-1420C, high-affinity binding of ATP to the nucleotide-binding fold (NBF)-1 was indistinguishable from that of wild-type SUR1. However, stabilization of ATP binding to NBF-1 by MgATP or MgADP was impaired, suggesting that this defect may account for impaired K(ATP)(SUR1-1420C) function. This is the first direct biochemical evidence that the cooperativity of nucleotide binding to SUR1 is impaired in a SUR1 mutant causing PHHI. No mutations were identified in the Kir6.2 and glutamate dehydrogenase genes. The genetic etiology of PHHI appears to be heterogeneous. SUR1 mutations may account for no more than 20% of PHHI cases in Japanese patients. Mutations of Kir6.2 and glutamate dehydrogenase genes are likely to be even less common.

ATP-Binding Cassette Transporters↗

PubMed2000

Autocrine motility factor receptor expression associates with tumor progression in thymoma.

We assessed the autocrine motility factor receptor (AMFR/gp78) expression in thymoma. AMFR/gp78 antigen was identified in tumor cells in 16 out of 51 (31.4%) thymomas. The AMFR/gp78 expression was closely associated with the stage (I/II vs. III/IV, p<0.0001), pathological subtypes (epithelial vs. other types, p=0.0214), and enhanced expression of alpha-smooth-muscle actin within stroma (p<0. 0001). The outcome of the patients with AMFR/gp78 expression was significantly worse than for those without it (p<0.01). All initial tumors with recurrence expressed AMFR/gp78. The AMFR/gp78 appears to be involved in tumor progression in thymoma.

Actins↗

PubMed2000

Combined effect of hop resins and sodium hexametaphosphate against certain strains of Escherichia coli.

The combined antimicrobial effects of hop resins with sodium hexametaphosphate, glycerol monocaprate, and lysozyme were investigated aiming to make an effective agent against Escherichia coli. When they are used separately, the antimicrobial activity against E. coli was minimal. However, the combination of hop resins with sodium hexametaphosphate exhibited strong antimicrobial activity against E. coli, but no effect was found in combinations of hop resins with the other agents. The activity was strongest when the combination was added at the beginning of growth of the bacteria, resulting in a prolonged lag phase. However, when the antimicrobials were added during the log phase, growth was depressed considerably. By addition of these materials, cell components with absorbance near 260 nm were leaked out. This possibly may have resulted from damage to the cell membranes of the bacteria. The combined effect was also detected in model food systems such as mashed potatos. The use of hop resins and sodium hexametaphosphate in combination may thus be useful for controlling E. coli.

Animals↗

PubMed2000

Natriuretic effect of barnidipine, a long-acting dihydropyridine calcium channel blocker, in patients with essential hypertension.

OBJECTIVE: To evaluate the effect of barnidipine hydrochloride, a long-acting dihydropyridine calcium channel blocker on urinary sodium excretion in patients with essential hypertension. PATIENTS: Twelve patients (2 males, 10 females) with mild to moderate essential hypertension. METHODS: A single-blinded study. After the control (placebo) period, 10 to 15 mg barnidipine hydrochloride was administered for 7 days, followed by a post-treatment (placebo) period. Daily changes in blood pressure, urinary volume, and urinary electrolyte excretions were evaluated. Plasma levels of atrial natriuretic peptide (ANP) and aldosterone were also determined in each period. Daily sodium intake was kept at 120 mEq. RESULTS: Blood pressure decreased from 161 +/- 4/92 +/- 2 mmHg to 146 +/- 4/85 +/- 2 mmHg (p<0.05) after 7-day-treatment with barnidipine. Barnidipine significantly increased urinary sodium excretion; the change was evident on the first day of administration (control period 41 +/- 3 mEq/day, and first day 59 +/- 3 mEq/day, p < 0.05). Drug discontinuation transiently decreased sodium excretion to 35 +/- 3 mEq/day. Cumulative sodium balance after 7-day-treatment reached 47 +/- 19 mEq. Urine volume, potassium excretion, and creatinine excretion did not change during the treatment period. The plasma levels of ANP tended to increase, but those of aldosterone did not change with barnidipine. CONCLUSION: Barnidipine administration for a week decreased the blood pressure and made the sodium balance negative by increasing the urinary sodium excretion in patients with essential hypertension. The natriuretic effect of this drug could contribute at least in part to its antihypertensive effect.

Adult↗

PubMed2000

Cerebral blood flow, vascular response and metabolism in patients with MELAS syndrome--xenon CT and PET study.

UNLABELLED: Two patients with MELAS syndrome underwent serial measurement of cerebral blood flow (CBF) with xenon CT while they were presenting stroke like episodes accompanying cerebral lesion detectable with CT. One of them underwent PET measurement of regional cerebral metabolic rate of oxygen (CMRO2) and glucose (CMRGlu) after his symptoms and lesion disappeared. METHODS: The xenon CT CBF study was performed by 4 min wash-in and 3 min wash-out protocol with serial measurement of endexpiratory concentration of xenon gas. The CBF after acetazolamide loading was also quantified in one of them. The PET study was performed to quantify CBF, CMRO2, oxygen extraction fraction (OEF) and cerebral blood volume (CBV) by continuous inhalation of O-15 labeled gases and arterial blood sampling. The PET measurement of CMRGlu was performed by i.v. injection of F-18 FDG and arterial blood sampling. RESULTS: 1) During the symptomatic period, Xe-CBF was normal or slightly increased both in and outside the low density lesion. 2) The CBF response to acetazolamide loading was well preserved both in and outside the low density lesions. 3) After the neurological symptoms and low density lesions disappeared, Xe-CBF pattern and vascular response was the same as during the symptomatic period. 4) In the PET study, normal or slightly increased PET-CBF, increased CMRGlu and markedly decreased CMRO2 in comparison to normal control was noted resulting in a marked decrease in OEF and CMRO2/CMRGlu ratio, a characteristic metabolic pattern for MELAS. CONCLUSION: In the present cases, resting CBF and vasomotor reactivity was well preserved both in symptomatic and remission period. On the contrary, abnormal metabolic pattern was noted. The stroke like episode of the present patients is more likely attributed to metabolic failure than vascular accident.

Adult↗

PubMed2000

[Interference by D-mannitol on serum D-arabinitol determination by enzymatic assay].

We examined a disparity in D-arabinitol values between two commercial assay kits, LABOFIT and ARABINITEC-AUTO. The determined values by the former were increased by 26%(y = 0.2643x) because of concomitant D-mannitol, whereas those by our newly developed ARABINITEC-AUTO was increased only by 2%(y = 0.0242x). Of 109 samples, 5 samples were found to contain more than 100 mumol/l of D-mannitol. A clear relation(r = 0.89) was noted between the degree of disparity between measurements by the two methods and D-mannitol concentrations in samples. Thus, we have proved that the disparity is mainly caused by D-mannitol.

Biomarkers↗

PubMed2000

[Thoracoscopic resection for benign solitary fibrous tumor of the parietal pleura].

We have experienced thoracoscopic surgery for benign solitary fibrous tumor of the parietal pleura. A 46-year-old woman was admitted to our hospital because of chest abnormal shadow. Under thoracoscopy the tumor that was connected to the parietal pleura with a wide pedicle was completely resected with combined parietal resection of the pleura. Pathological diagnosis was a benign solitary fibrous tumor developed from the connective tissues under the parietal pleura. Thoracoscopic surgery is well indicated for a solitary fibrous tumor and wide excision of the tumor with combined resection of the pleura is important to prevent a local recurrence.

Female↗

PubMed2000

[Abnormality of blood congulation].

Obstructive Sleep Apnea(OSA) is associated with an increased prevalence of cardiovascular complication such as systemic hypertension, ischemic heart disease and stroke, which may lead to unexpected or early death. Sleep in patients with OSA demonstrates a pattern of recurrent arousals, hemodynamic changes, and sympathetic neural activity that have been associated with adverse carviovascular events following awakening in the morning. Neurologic problems in patients with OSA include cognitive impairment, poor memory, and high risk for cerebral infarction. These central nervous system symptoms might be due to hypoxemia and sleep fragmentations. The vascular endothelial damage, platelet aggregation, and hemodynamic changes during sleep apnea are influenced by changes in oxygen and carbon dioxide tension inducing alterations of vascular tone. The cerebral hemodynamics in relation to apneas may not only influence daytime cerebral symptoms but may also have implications for the generation of cerebrovascular disease in OSA. These changes resulted from OSA might play an important role in pathophysiological aspects of the central nervous system. And these changes will be improved after CPAP application.

Blood Coagulation Disorders↗

PubMed2000

[Crescent moon-type tracheobronchial malacia alleviated by placement of stents in trachea and main bronchi].

We encountered a case of crescent-type tracheobronchomalacia in a 54-year-old male smoker. The patient experienced extreme obstructive pulmonary changes but his FVC and DLco findings were within the normal ranges. Plain chest X-ray films indicated tracheal narrowing, a diagnosis that was confirmed by fiberoptic bronchoscopy. Two Z-stents were implanted in the trachea but the patient's symptoms did not subside. Thoracic computed tomography (CT) elucidated stenosis of both main bronchi at end-expiration. The implantation of Z-stents in the main bronchi remarkably alleviated the symptoms and improved peak expiratory flow. Six months after implantation, the tracheal stents broke. A favorable course was obtained by inserting an ultraflex stent inside the broken Z-stents. DLco is important to the diagnosis of tracheobronchomalacia, whereas peak expiratory flow and thoracic CT findings are useful in evaluating the effectiveness of treatment. We concluded that ultraflex stents should be the first choice for treatment of tracheal stenosis, and that Z-stents are appropriate for the treatment of bronchial obstruction.

Bronchi↗

PubMed2000

Expression of CD40 and CD40 ligand in Bowen's disease and squamous cell carcinoma.

CD40 is a member of the tumor necrosis factor receptor super-family expressed by B cells, monocytes, dendritic cells, epithelial cells and hematopoietic progenitor cells. CD40 has recently been reported to be expressed on several epidermal tumors as well. CD40 on epidermal tumor cells interacts with lymphocytes expressing ligand for CD40 (CD40L) or monoclonal antibodies against CD40 with a significant decrease in proliferation. In this study, we examined the expression of CD40 and CD40L in Bowen's disease and squamous cell carcinoma (SCC). CD40 immunoreactivity was observed in a significantly lower proportion of tumor cells from SCC than from Bowen's disease. CD40L mRNA expression was detected in Bowen's disease and SCC by reverse transcriptase polymerase chain reaction (RT-PCR). CD40-CD40L interactions in epidermal tumors may play a role in the proliferation, and the lack of CD40 in tumor cells from SCC might be involved in the mechanisms of escape from the growth inhibitory effect.

Adult↗

PubMed2000

[Evaluation of new TNM classification for lung cancer, especially T3N0M0, stage IIIA, stage IIIB, and pm].

The purpose of this study was to evaluate the results of new TNM staging system for lung cancer in 1997, especially T3N0M0, stage IIIA, stage IIIB, and pm. Five-year survival rates of the patients with stage IIIA and stage IIIB were 16% and 18% respectively (NS). Five-year survival rates of patients with T3N1M0, T1N2M0, T2N2M0, and T3N2M0 were 40%, 28%, 15%, and 3%, respectively. The prognosis of T3N2M0 was significantly worse than that of T3N1M0, T1N2M0, and T2N2M0. Five-year survival rates of the patients excluding pm 1 with T4N0M0, T4N1M0, T4N2M0, and T4N3M0 were 21%, 10%, 10%, and 0%, respectively. The prognosis of the patients with T4N0 was significantly better than that of T4N2 and T4N3. In the patients with pm, 5-year survival rates of the patients with pm 1 and pm 2 were 26% and 7%, respectively (p < 0.01). In the patients with pm 1, 5-year survival rates of the patients with N0 + N1 and N1 + N2 were 53% and 16%, respectively (p < 0.01). From our these results, we supported the new TNM system as putting T3N0M0 to stage IIB, putting pm 2 into stage IV. We proposed; 1) chest wall invasion with bone destruction stay in stage IIIA or is T4, 2) T3N1M0 is classified with stage IIB, 3) main stem bronchus invasion is classified with T2, 4) pm 1 is subdivide by N status. Furthermore, stage III seemed to be reasonably subdivided into T1-2N3M0, T4N0-1M0 as stage IIIA and T3-4N2, T1-4N3 as stage IIIB.

Humans↗