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Biomedical subjects

T Ohyama

Publications and source records attributed to T Ohyama.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Field epidemiological investigation on an outbreak of Chlamydia pneumoniae infection--first recognized incidence in a nursing home for elderly in Japan].

Chlamydia pneumoniae (C. pneumoniae) is an emerging pathogen recognized in 1989. Although C. pneumoniae infection is known to give a great impact on public health in western countries, many aspects remain unclarified in Japan. During December 1999 and March 2000, respiratory symptoms among residents and employees in a nursing home for elderly implicated an outbreak of C. pneumoniae infection. Field epidemiological investigation confirmed that this is the first outbreak recognized in a nursing home setting in Japan, involving 31/59 (15 confirmed) residents and 9/41 (2 confirmed) employees. Fifteen residents developed severe C. pneumoniae infections including one fatal outcome with pneumonia. Epidemiological analysis did not identify risk factors which induce infection or severe illness by C. pneumoniae for the residents. However, for the employees, frequent contact with the residents was demonstrated as a significant risk factor for the infection. None of 13 employees who had no contact with the residents presented C. pneumoniae infection, while nine out of 28 employees who had frequent contact developed C. pneumoniae infections (RR infinite, P = 0.04). These results indicated that C. pneumoniae infection spread gradually by human-to-human droplet transmission without specific risk factors. This study raised current problems in diagnosing and treating the C. pneumoniae infection and the need to enhance the awareness of this disease.

Aged↗
PubMed2001

A case of multiple endocrine neoplasia type 2B undiagnosed for many years despite its typical phenotype.

We report the case of a 24-yr-old man with a typical phenotype of multiple endocrine neoplasia type 2B (MEN 2B). The patient had previously undergone minor surgery to remove multiple tumors on the lip, but he had no further examinations. MEN 2B was suspected owing to characteristic multiple ganglioneuromatosis when the patient presented with a goiter associated with high levels of plasma calcitonin and CEA. Aspiration biopsy cytology revealed medullary thyroid carcinoma (MTC), and abdominal computed tomography and nuclear scanning with metaiodobenzylguanidine revealed bilateral adrenomedullary tumors. Adrenomedullary function tests showed high levels of serum and urinary fractionated catecholamines, and genetic analysis showed a point mutation in the codon 918 (M918T) of the RET gene. The patient was diagnosed with MEN 2B and underwent right adrenalectomy and total thyroidectomy. No distant metastasis of the MTC was noted although MEN 2B had remained undiagnosed since the ganglioneuromatosis was first noticed. MEN 2B is a rare hereditary disorder, but the occurrence of characteristic ganglioneuromatosis was quite helpful in making the diagnosis.

Adrenal Gland Neoplasms↗
PubMed2001

Identification of two Fas-associated phosphatase-1 (FAP-1) promoters in human cancer cells.

Fas-associated phosphatase-1 (FAP-1) has been reported as a negative regulator of Fas-mediated signal transduction in human cancer cells. To obtain insights into the potential carcinogenesis of the FAP-1 gene, we investigated its transcriptional regulation in normal and cancerous cells. To identify the FAP-1 promoter sequences, we first isolated P1 and cosmid clones that contained the regulatory region upstream from the FAP-1 gene by using the PCR products of 5' rapid amplification of cDNA end (5'-RACE) as probes. Genomic analysis of positive clones revealed that the major FAP-1 mRNA was transcribed from its proximal promoter (pPRM) in all human cancer cell lines tested, but 1 additional large transcript derived from its distal promoter (dPRM) was found in the human colon cancer cell line DLD-1. This suggests that the FAP-1 gene may be aberrantly dysregulated in some types of human cancers, including colon carcinoma. Sequence analysis of the region upstream from the FAP-1 gene strongly suggests that the transcript of the FAP-1 gene may be controlled by a variety of transcriptional regulatory elements, including NF-kappa B, NF-IL6, and p53 in its 2 promoters. These results imply that the FAP-1 gene may be a target gene under the control of important apoptosis-related nuclear factors in human cancers.

5' Untranslated Regions↗
PubMed2001

Influence of dietary protein levels on beta-alanine aminotransferase expression and activity in rats.

beta-Alanine-oxoglutarate aminotransferase (beta-AlaAT I) and beta-alanine-pyruvate aminotransferase (beta-AlaAT II) catalyze the transamination reaction of omega-amino acids such as beta-alanine, beta-aminoisobutyrate, and gamma-aminobutyrate, amino acids that are not protein constituents. The influence of dietary protein levels on the expression and activities of these enzymes was investigated by using male rats. Both beta-AlaAT I and beta-AlaAT II activities in the liver were increased with the level of protein in the diet in accordance with changes in their mRNA levels. However, the beta-AlaAT I activity in the kidney was increased by protein-free and low-protein diets in relation to changes in its mRNA level. On the other hand, the level of beta-AlaAT II activity in the kidney was slightly decreased by a protein-free diet. Neither beta-AlaAT I nor beta-AlaAT II activities in the kidney were affected by a high-protein diet. These results suggested that beta-alanine may be used efficiently in animals fed a proteinfree or low-protein diet because the kidney provides beta-alanine by means of the hydrolysis of beta-alanyl-L-histidine (carnosine). The addition of beta-alanine to the diet significantly activated beta-AlaAT I in the kidneys of rats in accordance with changes in its mRNA level. In the rat brain, beta-AlaAT I activity was not altered by the dietary protein level or by the beta-alanine diet, and beta-AlaAT II activity was not detected.

Alanine Transaminase↗
PubMed2001

[Effectiveness of a new toothbrush with irrigation and suctioning capabilities (ty e-Brush) for removing supragingival plaque].

Patients with dysphagia typically have poor oral health. Because of improper swallowing, they cannot easily and safely clean their mouths. As a solution for such a problem, a manual toothbrush with both irrigation and suctioning functions has been developed, called the "e-Brush". The purpose of this study was to evaluate the cleaning effectiveness of the new e-Brush (9 mm and 11 mm in bristle length) for removing supragingival plaque, compared with a conventional toothbrush, GUM # 211 by Butler. In this study, 12 subjects (12 female of average age 20.6) were selected, and plaque control record (PCR) and scrubbing method were used. The following results were obtained: 1. Significant differences (p < 0.05) were recognized between e-Brush/9 mm (55.54 +/- 18.27%) and the others (e-Brush/11 mm: 30.88 +/- 8.14%, GUM # 211: 35.42 +/- 9.32%). 2. Bristles 9 mm in length were more effective than 11 mm bristles (p < 0.05). 3. Irrigation/suctioning function is more effective than the conventional tooth-brushing method. 4. The irrigation function of e-Brush was meritorious in making almost all users comfortable. These results suggest that this new oral hygiene device, "e-Brush/9 mm", is effective for improving oral care management for patients with dysphagia.

Adult↗
PubMed2001

[Narrowing of the dental pulp cavity in patients undergoing long-term administration of steroids].

The purpose of this study was to examine narrowing of the dental pulp cavity in patients undergoing long-term administration of steroids, by means of intraoral radiographs. The subjects were 20 patients under long-term steroid treatment (the steroid group), and 15 patients who were not receiving steroids (the non-steroid group), who visited the Clinic for Persons with Disabilities, University Hospital, Faculty of Dentistry, Tokyo Medical and Dental University, between April 1994 and March 2000. The dental pulp cavity was divided into the coronal area and the root area. Narrowing of each area was classified into three stages by means of intraoral radiographs (0, none; 1, moderate; 2, severe). Maxillary and mandibular dentition was divided, for purposes of analysis, into anterior, premolar, and molar areas, respectively. The narrowing of each part was statistically compared between the steroid group and the non-steroid group, using the Mann-Whitney U-test. Mean age +/- SD of the steroid group and the non-steroid group was 50.5 +/- 17.3 and 51.8 +/- 14.1, respectively. There was no significant difference in mean age between the steroid group and the non-steroid group (t-test). Narrowing of the dental pulp cavity in the steroid group was significantly greater than in the non-steroid group, except in the root area of the molar part. Since there was no significant difference in mean age between the steroid group and the non-steroid group, the greater narrowing in the steroid group was concluded to be attributable to the long-term administration of steroids.

Adolescent↗
PubMed2001

Rapid N transport to pods and seeds in N-deficient soybean plants.

Non-nodulated soybean (Glycine max (L.) Merr.) plants were cultivated hydroponically under N-sufficient (5 mM NaNO(3)) or N-deficient (0.5 mM NaNO(3)) conditions. (13)N- or (15)N- labelled nitrate was fed to the cut end of the stems, and the accumulation of nitrate-derived N in the pods, nodes and stems was compared. Real-time images of (13)N distribution in stems, petioles and pods were obtained using a Positron Emitting Tracer Imaging System for a period of 40 min. The results indicated that the radioactivity in the pods of N-deficient plants was about 10 times higher than that of N-sufficient plants, although radioactivity in the stems and nodes of N-deficient versus N-sufficient plants was not different. A similar result was obtained by supplying (15)NO(3) to cut soybean shoots for 1 h. The fact that the N translocation into the pods from NO(3) fed to the stem base was much faster in N-deficient plants may be due to the strong sink activity of the pods in N-deficient plants. Alternatively, the redistribution of N from the leaves to the pods via the phloem may be accelerated in N-deficient plants. The temporal accumulation of (13)NO(3) in nodes was suggested in both N-sufficient and N-deficient plants. In one (13)NO(3) pulse-chase experiment, radioactivity in the stem declined rapidly after transferring the shoot from the (13)NO(3) solution to non-labelled NO(3); in contrast, the radioactivity in the node declined minimally during the same time period.

Amino Acids↗
PubMed2001

Evaluation of a mass influenza vaccination campaign.

Kawaura, a rural town in Kumamoto Prefecture, Japan, population approximately 6,800, started a mass influenza vaccination campaign in the 1999-2000 season for all residents > or = 3 years of age. The town provided free vaccinations to children < or = 13 years and the elderly > or = 65 years. Only 900 yen (US$8.80) was charged to the other residents for two vaccinations. In the 1999-2000 season, a total of 5,563 doses of vaccine were administered to 2,952 residents. Over 90% of the vaccinees received two doses. The program resulted in a vaccination rate of 43% of all residents. The vaccination rates for females and males were 40.7% and 36.8%, and for those of 3-14 years, 15-64 years, and > or = 65 years population were 75%, 31%, and 55%, respectively. The town spent a total of 5.78 million yen (US$56,700) for the campaign. The per-shot cost was estimated as 1,683 yen (US$16.50). From December 1999 through March 2000, a total of 233 town residents (15-101 years old, median 72) were admitted to the town hospital. Of the 233 inpatients, 22 (66-98 years old, median 78) developed respiratory illness, with 4 fatal outcomes. Of these 22 cases, 3 had been vaccinated twice, while 19 had not been vaccinated at all. The relative risk of vaccinees' hospitalization due to respiratory illness decreased to 0.13 compared with that of non-vaccinees (3/1,203 versus 19/1,003, vaccine efficacy = 0.87). Likewise, the relative risk of vaccinees death due to respiratory illness decreased to 0.28 compared with that of non-vaccinees (1/1,203 versus 3/1,003). The results of the Kawaura town's initiative should be helpful for better modeling of mass influenza vaccination campaigns.

Adolescent↗
PubMed2001

Modal analysis of the maxillary dentition in cleft lip and palate patients before and after bone grafting.

The aim of this study was to analyze the vibratory characteristics in the maxillary dentition of 4 cleft lip and palate (CLP) patients before and after bone grafting. First, the central incisor on the noncleft side was impacted with an impact hammer, and the responses were received using an acceleration sensor from the teeth between the upper first molars on both sides. The transfer functions were then obtained from each measurement point using a fast Fourier transform analyzer. Finally, a computer analysis and simulation were performed based on the measured transfer functions to obtain the natural frequency, modal shape, decay rate (DR) and maximum displacement (MDP). Before bone grafting, distinct phase differences between the major and minor dental arches (MDA and mDA) were observed in the modal shapes. After surgery, however, both the MDA and mDA vibrated in phase. These results were identical in all subjects. The MDPs of the central incisors conspicuously decreased after bone grafting in 3 subjects. From the standpoint of vibratory characteristics, this study indicated that bone grafting had a favorable effect on prosthodontic treatment using a fixed prosthesis across the cleft in CLP patients.

Acceleration↗
PubMed2001

Dynamic retentive force of a mandibular unilateral removable partial denture framework with a back-action clasp.

PURPOSE: The purpose of this study was to investigate the dynamic retentive force of a mandibular unilateral distal-extension partial denture framework with a back-action clasp that was designed in a buccally tilted cast on a dental surveyor. The retention mechanism of this framework was analyzed in comparison with other typical unilateral and bilateral frameworks for the mandibular Kennedy class II case. MATERIALS AND METHODS: Experimental gold alloy frameworks of three designs were repositioned to the master cast, and lifted upward to the vertical direction to the occlusal plane. The load required to dislodge each framework was recorded. The retentive force of each framework was determined by the maximum load in a dislodgment cycle. The bending strength of a plain clasp pattern of the same length as the clasp arm used in each framework was also measured by cantilever beam test. RESULTS: The mean retentive force of the unilateral framework with a back-action clasp of relatively low bending strength was significantly higher (P < 0.01) than that of the unilateral framework with two Akers clasps of relatively high bending strength, and 70 to 80% of the bilateral framework with two Akers clasps on the edentulous side and a double Akers clasp on the contralateral side. The unilateral framework with a back-action clasp showed the greatest early load resistance in the dislodgment cycle among the three designs. CONCLUSION: The reasonable retention mechanism was demonstrated by the unilateral framework with a back-action clasp.

Dental Abutments↗
PubMed2001

Masticatory mandibular movements for different foods textures related to onomatopoetic words.

This study aimed to investigate the effects of different sensory-evaluated food textures on masticatory movements, and to identify meaningful factors that correspond to different food textures. Masticatory movements of three healthy subjects were evaluated with a jaw movement tracking device using five different test foods: almond, hard and light rice crackers, apple, and chewing gum. The movements of the incisor point, working and non-working condyle and the entire mandible at the occlusal phase in the horizontal plane were analyzed. For harder foods, the incisor entered the intercuspal position from a rear and lateral, the working condyle showed anterior and noticeable medial movements as the entire mandible translated posteriorly and medially. For soft foods, the incisor movements were nearly coincidental with the lateral border movements, and the mandible rotated towards the inner side near the working condyle. Although the overall paths of the mandibular movements are individually different, it appeared that jaw movement at the final closure is particular to the food texture. From the standpoint of mandibular movements, it is suggested that masticatory movements during the occlusal phase in the horizontal plane is useful for revealing the relationship between mandibular movements and food textures that were evaluated with onomatopoetic words.

Adult↗
PubMed2000

TNF-alpha stimulation of MCP-1 expression is mediated by the Akt/PKB signal transduction pathway in vascular endothelial cells.

MCP-1 is expressed in a variety of cell types including vascular endothelial cells following induction by different stimuli such as tumor necrosis factor (TNF)-alpha. Although TNF-alpha stimulates MCP-1 expression and secretion, the mechanism by which TNF-alpha stimulates expression of the MCP-1 gene is not known. In this study, we examine the involvement of the phosphatidylinositol-3-OH kinase (PI3-kinase)-Akt/PKB pathway. Exposure of human umbilical vein endothelial cells (HUVECs) to TNF-alpha elicited the rapid phosphorylation of Akt/PKB. In HUVECs, wortmannin, a PI3-kinase inhibitor, inhibits TNF-alpha-mediated MCP-1 secretion at a dose-dependent manner. Constitutively active form of Akt/PKB induces transcription of the MCP-1 gene, and cotransfection of dominant negative Akt/PKB suppressed the activation of the MCP-1 promoter induced by TNF-alpha. These findings show that Akt/PKB participates in the TNF-alpha induction of MCP-1 gene transcription in endothelial cells.

Androstadienes↗
PubMed2000

Conservation of DNA bend sites with identical superhelical twists among the human, mouse, bovine, rabbit and chicken beta-globin genes.

We reported previously that DNA bend sites appear in the human beta-globin locus at an average distance of 680 bp. The relative locations of the sites were conserved among the five active beta-like globin genes and one pseudogene. Here, we mapped the sites in the beta-like globin genes from various species and examined their conservation. The locations of the bend sites in the bovine, rabbit and chicken beta-globin genes mapped here showed marked conservation in their locations relative to the cap site and showed similar locations to the previously mapped sites in the human beta- and mouse betamaj-globin genes. Further analysis of the first bend sites from the cap site (B-1 sites) indicated that they contained tracts of adenines and thymines longer than or equal to two bases. This sequence feature contributed mostly to the curvature profiles revealed by gel assays and/or by computer-based TRIF analysis. TRIF analysis indicated that most of the B-1 sites showed right-handed superhelical twists accompanied by left handed twists. This was confirmed by the effect of ethidium bromide on the superhelical twists in the assays.

Adenine↗
PubMed2000

Negative regulation of Fas-mediated apoptosis by FAP-1 in human cancer cells.

FAP-1 (Fas-associated phosphatase-1) was previously identified as a protein that associates with a negative regulatory domain (C-terminal 15 amino acids) of Fas using the yeast 2-hybrid system. Functional analysis indicated that FAP-1 expression correlates with resistance to Fas-induced apoptosis in human cancer cells. We first generated anti-FAP-1 polyclonal antibody and confirmed the interaction of FAP-1 and Fas in vivo. FAP-1 interacted with wild-type, but not mutant, Fas (tPLV) in 293T cells after transfecting FAP-1 and Fas or its mutant. To investigate the functional role of FAP-1 in Fas-mediated signal transduction, we established stable transfectants of FAP-1 in 3 human cancer cell lines. Apoptosis assays demonstrated that cancer cells over-expressing FAP-1 increased the resistance to Fas-induced apoptosis by the anti-Fas antibody CH-11 in contrast with the wild types or the vector-transfected cells. In addition, FAP-1 regulated the activity of both caspases 3 and 8. Our data indicate a functional role for FAP-1 as a negative regulator of Fas-mediated apoptosis in human cancer cells and suggest that an additional signal-transducing molecule may be required for complete suppression of Fas-mediated apoptosis.

Antibodies↗
PubMed2000

Recognition of a cognate RNA aptamer by neomycin B: quantitative evaluation of hydrogen bonding and electrostatic interactions.

Aminoglycosides are an important class of antibiotic that selectively target RNA structural motifs. Recently we have demonstrated copper derivatives of amino-glycosides to be efficient cleavage agents for cognate RNA motifs. To fully develop their potential as pharmaceutical agents it is necessary to understand both the structural mechanisms used by aminoglycosides to target RNA, and the relative contributions of hydrogen bonding and electrostatic interactions to recognition selectivity. Herein we report results from a calorimetric analysis of a stem-loop 23mer RNA aptamer complexed to the aminoglycoside neomycin B. Key thermodynamic parameters for complex formation have been determined by isothermal titration calorimetry, and from the metal-ion dependence of these binding parameters the relative contributions of electrostatics and hydrogen bonding toward binding affinity have been assessed. The principal mechanism for recognition and binding of neomycin B to the RNA major groove is mediated by hydrogen bonding.

Base Sequence↗
PubMed2000

Cerebellar function: coordination, learning or timing?

Theories of cerebellar function have largely involved three ideas: movement coordination, motor learning or timing. New evidence indicates these distinctions are not particularly meaningful, as the cerebellum influences movement execution by feedforward use of sensory information via temporally specific learning.

Animals↗