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Biomedical subjects

Y Sato

Publications and source records attributed to Y Sato.

At least 433 records · Page 24Linked to original sources
PubMed2000

Development of monocrotaline-induced pulmonary hypertension is attenuated by a serotonin receptor antagonist.

The significance of serotonin in the pathogenesis of monocrotaline-induced pulmonary hypertension (MCT-PH) in rats, plasma serotonin concentrations, and the effect of a serotonin receptor antagonist administration in association with the number of proliferative cells were investigated. The thickness of the media of the small pulmonary arteries and the weight ratio of the RV to that of LV + S (RV/[LV + S] weight ratio) were used as indices of the severity of PH. Plasma serotonin concentrations were measured by high-performance liquid chromatography. Histopathologic analysis of the lung tissue was performed by hematoxylin-eosin and elastin van Gieson staining. Immunohistopathologic staining for proliferating cell nuclear antigen (PCNA) was performed to identify proliferative cells. The severity of PH as determined by the medial thickness of the small pulmonary arteries and RV/(LV + S) weight ratio in rats with MCT-PH was significantly reduced after treatment with MCI-9042 (p < 0.01 and p < 0.05, respectively). The serotonin concentration was significantly greater in MCT-PH rats than in normal control rats (p < 0.05). The scores for histopathologic changes, such as thickening of the alveolar walls and interstitial inflammatory cell infiltration in MCT-PH rats, were significantly reduced after treatment with MCI-9042 (p < 0.05 and p < 0.01, respectively). The number of PCNA-positive cells was significantly greater in MCT-PH rats than in normal control rats (p < 0.0001) and was reduced after treatment with MCI-9042 (p < 0.0001). Treatment with MCI-9042 significantly inhibited the development of MCT-PH along with a decrease in the number of PCNA-positive cells, suggesting a pivotal role of serotonin in the development of PH induced by MCT.

Animals↗
PubMed2000

The expression of mRNA of proinflammatory cytokines during skin wound healing in mice: a preliminary study for forensic wound age estimation (II).

This study examined the temporal expression of mRNA for the proinflammatory cytokines, interleukin (IL)-1alpha, IL-1beta, IL-6 and tumor necrosis factor-alpha (TNFalpha) in incised wounds in mice using the reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization (ISH) techniques. After incision, an increase in each cytokine mRNA level was observed by RT-PCR. The local IL-6 mRNA level peaked at 6 h, while the peak levels of mRNA for IL-1alpha, IL-1beta and TNFalpha occurred between 48 and 72 h. All cytokine mRNA levels were almost normalized after 240 h. In the early phase of wound healing, infiltrating polymorphonuclear cells were labeled with antisense probes for IL-1alpha, IL-1beta and TNFalpha mRNA by the ISH technique. Thereafter, infiltrating mononuclear cells and spindle-shaped mesenchymal cells showed positive signals for all the cytokines examined. Regenerating epidermal cells were also labeled with the antisense probes for IL-1alpha, IL-6 and TNFalpha mRNA, indicating that IL-1, IL-6, and TNFalpha are involved in skin wound healing and their local production by various cells involved in the healing process is suggested. From the viewpoint of forensic pathology, the temporal characteristics of the cytokine mRNA expression may have a potential to indicate wound age or wound vitality.

Animals↗
PubMed2000

Ventilatory and circulatory responses at the onset of voluntary exercise and passive movement in children.

The purpose of this study was to investigate whether or not the ventilatory and circulatory responses at the onset of voluntary exercise and passive movement, especially at the initial stage (phase I), in children are the same as in adults. Ten pre-teenage male children and ten adult men participated in this study. Voluntary exercise and passive movement were performed in a sitting position for about 20 s. Both the exercise and the movement consisted of flexion-extensions of the lower leg from a vertical to horizontal position, either voluntarily or passively, with a frequency of about 60 x min(-1). Inspiratory minute ventilation (V1), tidal volume (VT), respiratory frequency, partial pressure of end-tidal CO2 and O2, heart rate (fc) and mean blood pressure (BP) before, during and after exercise or movement were measured using breath-by-breath and beat-to-beat techniques. Cardiorespiratory responses at the onset of voluntary exercise and passive movement were compared with the relative change (delta), which was estimated from the value at rest (100%). In the present study, it was found that: (1) the V1 during voluntary exercise were significantly lower in the children, mainly due to lower deltaVT; (2) the delta(f)c during voluntary exercise was almost the same in both groups, while deltaf(c) was significantly lower in the children during the last part of passive movement; (3) in the voluntary exercise and passive movement, the BP in the children was increased a little or remained close to the value at rest, while it was significantly decreased in the adults. As a result, there were significant differences in deltaBP between the two groups during voluntary exercise. These results suggest that the cardiorespiratory responses at the onset of voluntary exercise and passive movement may be modified during the growth process.

Adult↗
PubMed2000

Intracellular chloroplast photorelocation in the moss Physcomitrella patens is mediated by phytochrome as well as by a blue-light receptor.

The light-induced intracellular relocation of chloroplasts was examined in red-light-grown protonemal cells of the moss Physcomitrella patens. When irradiated with polarized red or blue light, chloroplast distribution in the cell depended upon the direction of the electrical vector (E-vector) in both light qualities. When the E-vector was parallel to the cross-wall (i.e. perpendicular to the protonemal axis), chloroplasts accumulated along the cross-wall; however, no accumulation along the cross-wall was observed when the E-vector was perpendicular to it (i.e. parallel to the protonemal axis). When a part of the cell was irradiated with a microbeam of red or blue light, chloroplasts accumulated at or avoided the illumination point depending on the fluence rate used. Red light of 0.1-18 W m-2 and blue light of 0.01-85.5 W m-2 induced an accumulation response (low-fluence-rate response; LFR), while an avoidance response (high-fluence-rate response; HFR) was induced by red light of 60 W m-2 or higher and by blue light of 285 W m-2. The red-light-induced LFR and HFR were nullified by a simultaneous background irradiation of far-red light, whereas the blue-light-induced LFR and HFR were not affected at all by this treatment. These results show, for the first time, that dichroic phytochrome, as well as the dichroic blue-light receptor, is involved in the chloroplast relocation movement in these bryophyte cells. Further, the phytochrome-mediated responses but not the blue-light responses were revealed to be lost when red-light-grown cells were cultured under white light for 2 d.

Bryopsida↗
PubMed2000

Nuclear accumulation of beta-catenin in intestinal-type gastric carcinoma: correlation with early tumor invasion.

Mutation of the adenomatous polyposis coli gene, which is known to be an early event in the carcinogenesis of intestinal-type gastric carcinoma, leads to accumulation of beta-catenin. In addition, beta-catenin has been found to activate down stream signaling molecules in the wingless/Wnt pathway. In this study, the clinical significance of nuclear accumulation of beta-catenin was evaluated in gastric carcinoma. Immunohistochemical staining showed nuclear localization in 16 (12%) of 139 (94 intestinal-type and 45 diffuse-type) gastric carcinomas, and all 16 lesions with nuclear staining were intestinal-type adenocarcinomas. Of the 16 cases, 15 were in the early clinical stage. In the remaining case, the lesion had invaded the subserosal layer and showed strong nuclear staining at the invasive front. In 14 of the 16 cases with nuclear localization, there were no abnormal mobility shifts detected using polymerase chain reaction-single strand conformational polymorphism analysis. This was confirmed using direct sequencing analysis, which revealed the wild-type sequence in the 12 cases tested. Nuclear accumulation of beta-catenin did not correlate with lymph node metastasis or 5-year survival. These findings suggest that high intranuclear levels of beta-catenin protein play an important role in early tumor growth and may function in initiation of invasive processes in intestinal-type gastric carcinoma.

Adenocarcinoma↗
PubMed2000

New approaches for successful islet transplantation.

The long-term control of glucose metabolism is expected to be achieved with insulin-secreting pancreatic islets transplanted as the whole pancreas or isolated islet tissue. The current clinical outcomes of such procedures are unsatisfactory compared with that of whole organ transplantation or experimental islet transplantation, although the safety of the transplantation procedure itself is assured. In this review, we first describe the immunological characteristics of purified islets in an attempt to explain the differences between the results for human and experimental islet transplantation. We then introduce new approaches currently undertaken in our laboratory that could, we hope, make islet transplantation more successful.

Adjuvants, Immunologic↗
PubMed2000

Anti-cathepsin G antibodies in the sera of patients with ulcerative colitis.

The presence of perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCAs) and that of antibodies against cathepsin G, a target antigen for P-ANCAs, was determined in the sera of patients with ulcerative colitis (UC), relative to the endoscopic severity and disease activity. P-ANCAs were detected by indirect immunofluorescent assay (IIF) on ethanol-fixed human neutrophils. Antibodies to cathepsin G were detected by an enzyme-linked immunosorbent assay (ELISA) and Western blotting. P-ANCAs were detected by IIF in 62.5% of 32 patients with active UC. Anti-cathepsin G antibodies were detected in 40.6% of 32 patients with active UC, and their prevalence was significantly higher in patients with severe colitis, as determined by endoscopy, than in those with mild or moderate colitis (P < 0.05). The prevalence and titers of anti-cathepsin G antibodies were significantly higher during the active than the inactive phase of the disease (P < 0.05). Measurement of titers of anti-cathepsin G antibodies by ELISA in the serum is useful for evaluating the activity of UC.

Adolescent↗
PubMed2000

Significance of low mRNA levels of interleukin-4 and -10 in mononuclear cells of the synovial fluid of patients with rheumatoid arthritis.

Our objective was to investigate the clinical significance of Th1 and Th2-type cytokines, such as interferon-gamma (IFNgamma) interleukin (IL)-12, IL-4 and IL-10, in the mononuclear cells (MNC) of the synovial fluid (SF) in patients with rheumatoid arthritis (RA). The cytokine production in the MNC obtained from the SF (SF-MNC) in 30 patients with RA and 10 with gout was examined by measuring the mRNA levels of IFNgamma, IL-12, IL-4 and IL-10 by semiquantitative RT-PCR. The mRNA levels of IFNgamma, IL-4 and IL-10 were significantly higher in the SF-MNC of RA patients than in those of gout patients (p<0.001, p<0.01 and p<0.001, respectively). Correlations between mRNA levels were significant for IL-12 and IL-4, IL-12 and IL-10, and IL-4 and IL-10 (p<0.05). The mRNA levels of IL-4 and IL-10 were very low compared to those of IL-12 in seven of the 30 patients with RA; all of these patients were in stage 4, and serum levels of CRP, ESR and blood platelet count which are considered as indices of the severity of inflammation, were significantly elevated in these seven patients compared to the other 23 RA patients. The markedly reduced synthesis of both IL-4 and IL-10 mRNA could be considered to be related to the progression and/or activity of RA. The results of this study therefore indicate an imbalance in the levels of Th1 and Th2 cytokines at the site of inflammation in RA, and draw attention to the possibility of treatment of progressive or intractable RA with IL-4 and/or IL-10.

Adult↗
PubMed2000

Effects of fluconazole on viable cell count in experimental intraperitoneal Candida abscesses.

We investigated the effects of fluconazole in experimental intraperitoneal Candida abscesses in neutropenic mice treated with cyclophosphamide to assess a clinically appropriate method for the application of fluconazole in fungal infections in patients with neutropenia. The efficacy of fluconazole in fungal infection was investigated in treatments started immediately after Candida albicans inoculation and before C. albicans inoculation (preventive use of fluconazole). In this intraabdominal fungal abscess model, it was confirmed that fungi in already formed abscess were not reduced in number by fluconazole, even when those fungi were susceptible to fluconazole. Fluconazole was effective with both administration methods. We conclude from this study that the effect of the preventive use of fluconazole was equivalent to the effect when treatment was started immediately after fungal inoculation.

Abdominal Abscess↗
PubMed2000

Vaginal microflora in healthy women with Gardnerella vaginalis.

In order to find the vaginal prevalence of Gardnerella vaginalis in a normal female population, we determined the incidence of G. vaginalis in relation to that of other bacterial genera and species in the vagina. Two-hundred and thirty-nine healthy women were the subjects of this study. Vaginal discharge was collected and bacteriological studies were performed. The mean total aerobe count in the G. vaginalis-positive group was 9.02 log10 colony-forming units (CFU)/g, which was significantly higher (P < 0.0001) than that (6.80 log10 CFU/g) in the G. vaginalis-negative group. In contrast, there was no difference in the mean total anaerobe count between the two groups of subjects (8.82 and 8.24 log10 CFU/g, respectively in the case of including Lactobacillus species count). Also, the mean pH level of vaginal secretion in the G. vaginalis-positive group was 4.58, which was significantly higher (P < 0.005) than that (4.10) in the G. vaginalis-negative group. Aerobes were isolated at equal incidence in the two groups. Anaerobes were isolated at a significantly higher rate in the G. vaginalis-positive group (P < 0.005) than in the G. vaginalis-negative group. The mean count of Lactobacillus species was significantly higher (P < 0.0001) in the G. vaginalis-negative group than in the positive counterpart (7.02 vs 8.66). Elevation of vaginal pH, an increase in the anaerobe count, and decreases in the Lactobacillus species count could be good predictors of the prevalence of bacterial vaginosis in healthy women.

Adolescent↗
PubMed2000

Abnormal bone and calcium metabolism in patients after stroke.

OBJECTIVE: To review how mineral stores and endocrine factors affect bone mass in poststroke patients immobilized by hemiparesis. DATA SOURCES: Computer databases and published indexes. STUDY SELECTION: Case-control studies of hemiparetic poststroke patients examined regarding bone metabolism. DATA EXTRACTION: References were obtained from MEDLINE; all data concerning the objective were used. DATA SYNTHESIS: Bone loss occurs in affected extremities after stroke. Immobilization from hemiplegia causes hypercalcemia. Insufficiency or deficiency of 25-hydroxyvitamin D (25-OHD) is very common in stroke patients and may be caused by poor dietary intake, decreased sunlight exposure, or both. Compensatory hyperparathyroidism may not occur because hypercalcemia inhibits the parathyroid glands even when 25-OHD is in the insufficient range. However, hyperparathyroidism does occur when 25-OHD is in the deficient range, in which case the parathyroid response to hypovitaminosis D overrides effects of hypercalcemia. Increased bone resorption was observed during the first year after stroke, declining to normal during the second year. During the first year, determinants of bone mineral density (BMD) in hands affected by hemiplegia were age, severity of hemiplegia, duration of paralysis, serum calcium concentration, and 25-OHD concentration. In the second year, BMD determinants on the hemiplegic side were severity of hemiplegia and 25-OHD concentration, whereas 25-OHD concentration was the only BMD determinant on the intact side. Administering 1alpha-hydroxyvitamin D3, vitamin K2, or ipriflavone ameliorated osteopenia on both sides and decreased the frequency of hip fracture on the hemiplegic side. CONCLUSIONS: Bone remodeling and determinants of bone mass for the affected and unaffected sides after stroke differ between the first and subsequent years.

Bone and Bones↗
PubMed2000

Direct observation of specific messenger RNA in a single living cell under a fluorescence microscope.

We observed the expression of human c-fos mRNA in a living transfected Cos7 cell under a fluorescence microscope by detecting hybrid formed with two fluorescently labeled oligodeoxynucleotides (oligoDNAs) and c-fos mRNA in the cytoplasm. Two fluorescent oligoDNAs were prepared, each labeled with a fluorescence molecule different from the other. When two oligoDNAs hybridized to an adjacent sequence on the target mRNA, the distance between the two fluorophores became very close and fluorescence resonance energy transfer (FRET) occurred, resulting in changes in fluorescence spectra. To find sequences of high accessibility of c-fos RNA to oligoDNAs, several sites that included loop structures on the simulated secondary structure were selected. Each site was divided into two halves, and the pair of fluorescent oligoDNAs complementary to the sequence was synthesized. Each site was examined for the efficiency of hybridization to c-fos RNA by measuring changes in fluorescence spectra when c-fos RNA was added to the pair of oligoDNAs in solution. A 40 mer specific site was found, and the pair of oligoDNAs for the site were microinjected into Cos7 cells that expressed c-fos mRNA. To block oligoDNAs from accumulating in the nucleus, oligoDNA was bound to a macromolecule (streptavidin) to prevent passage of nuclear pores. Hybridization of the pair of oligoDNAs to c-fos mRNA in the cytoplasm was detected in fluorescence images indicating FRET.

Animals↗
PubMed2000

Creating a vertical stop for interocclusal records.

This article describes a method of making an accurate interocclusal record when the most distal tooth is an abutment of a fixed partial denture. The method uses conical stops, prepared in the enamel of the abutment or made of composite or a metal core covered with composite, to maintain the vertical dimension of occlusion and to act as a third point of reference for a stable occlusal relationship when occluding the definitive casts. This article also explains how to use the cones and how to make each variety.

Dental Abutments↗
PubMed2000

Proximal plate in conventional circumferential cast clasp retention.

Improper guiding planes are commonly used with conventional removable partial denture cast clasps. Short guiding planes with improper proximal plates decrease retention and cause repetitive traumatic movement of abutments. This article discusses the importance of guiding planes and proximal plates for conventional tooth-supported removable partial dentures with circumferential clasp. The retention force of the clasps was analyzed geometrically. If the guiding plane is short or the prepared surface is oblique, the contact between the proximal plate and the guiding plane or oblique plane diminishes at an early stage, which results in reduction of retention. The guiding plane should be parallel to the path of insertion and must be of a certain length for adequate retention. An elongated proximal plate that is parallel to the path of insertion may compensate for retention deficiency when an adequate guiding plane cannot be prepared.

Dental Abutments↗
PubMed2000

Immediate maxillary denture base extension for posterior palatal seal.

A procedure for extension of the maxillary denture base for development of a posterior palatal seal is described. The technique involves provisional extension with paraffin wax and adding direct relining resin supported by a silicone putty core. This simple, quick procedure achieves immediate recovery of retention for underextended maxillary dentures without additional laboratory procedures.

Dental Polishing↗