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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 73 records · Page 4Linked to original sources
PubMed2001

Pharmacological characterization and visualization of the glial serotonin transporter.

Astrocytes contain transport systems that are capable of removing various neurotransmitters from the synaptic cleft by transporters present in the plasma membrane. Glial serotonin transporter (SERT) plays an important role in the re-uptake of 5-hydroxytryptamine (5-HT). We examined the pharmacological characterization of 5-HT uptake into rat cortical synaptosomes and cultured rat astrocytes, and the immunodetection of glial SERT proteins using specific site-directed monoclonal antibodies (MoAb). Furthermore, using a reverse transcriptase-polymerase chain reaction (RT-PCR) method, we addressed the expression of SERT mRNA in cultured rat astrocytes. We investigated the inhibitory effects of various monoamine uptake inhibitors on the uptake of [3H]5-HT into cultured astrocytes and cortical synaptosomes. Tricyclic antidepressants (clomipramine and imipramine) as well as selective serotonin re-uptake inhibitors (fluvoxamine, fluoxetine and zimelidine) were very potent inhibitors of [3H]5-HT uptake in both preparations. In contrast, the inhibitory effects of NE uptake inhibitors (nisoxetine and desipramine) and cocaine were weaker than those of 5-HT uptake inhibitors. In addition, dopamine (DA) uptake inhibitors (nomifensine and GBR-12935) exhibited a Ki value in the low micromolar range. The inhibitory potencies were in the order 5-HT uptake inhibitors (clomipramine, fluvoxamine, fluoxetine, imipramine and zimelidine) > NE uptake inhibitors (nisoxetine and desipramine) = cocaine > DA uptake inhibitors (nomifensine and GBR-12935). There was no difference in the order of the inhibitory effects of various monoamine uptake inhibitors between the two preparations. A correlation analysis of the potencies of various monoamine uptake inhibitors in the inhibition of [3H]5-HT into cultured astrocytes and cortical synaptosomes produced a highly significant correlation coefficient of 0.9893 (P < 0.0001). Immunocytochemical staining using anti-SERT MoAb in cultured astrocytes revealed that the plasma membrane, as well as intracellular, perinuclear compartments, presumably endoplasmic reticulum or golgi membranes, showed a considerable level of immunoreactivity. Extracts of astrocytes and synaptosomes from the cortex were immunoblotted with anti-SERT MoAb. SDS-PAGE/Western blots indicate that anti-SERT MoAb recognized two bands of 120 and 73 kDa in both preparations. RT-PCR demonstrated that astrocytes in cultured expressed mRNA for the cloned SERT protein, which has been characterized as the neuronal SERT. These pharmacological experiments indicate that this uptake process takes place through glial SERT that is very similar to neuronal SERT. Furthermore, the present data also indicate that the presence of the mRNA and protein for the neuronal SERT were established in cultured rat astrocytes, and the polypeptide portion of SERT in astrocytes and frontal cortex could be the same gene product.

Animals↗
PubMed2001

Age-specific prevalence of open-angle glaucoma and its relationship to refraction among more than 60,000 asymptomatic Japanese subjects.

To clarify the prevalence of open-angle glaucoma (OAG) and its relationship to refraction among a Japanese population with a broad range of ages including children and adolescents, an 1-year epidemiological survey was conducted. The subjects of this study were 64,394 asymptomatic individuals who had attended the glasses and contact lens center in Yokohama, Japan from February 15, 1999 to February 14, 2000 and had been subjected to several optical examinations. The results of this study showed that the overall prevalence of OAG was 1.19% (1.14% for men, and 0.98% for women). Prevalence for children aged 6 to 14 of both sexes was approximately 0.5%. There were significant positive associations between the strength (diopter) of myopic refraction and OAG prevalence among all the examined subjects.

Adolescent↗
PubMed2001

The magnitude of variation in temperature within a year has an effect on the seasonal variations of chickenpox incidence in Japan.

We investigated the epidemic pattern of chickenpox incidence among 47 prefectures in Japan. There were two peaks in chickenpox incidence in all prefectures. The first peaks appear at almost the same time in a year, while the second peaks occur at different times with relatively different types of size and shape. The feature of the second peak might characterize the epidemic pattern of chickenpox. We first introduced the second peak index, that is, the ratio of the difference between the incidence at the point of the second peak and the minimum incidence between the first and second peaks to the difference between the incidence at the point of the second peak and the minimum incidence in the year. There was a close correlation between the second peak index and the magnitude of variation in temperature within a year corresponding to the difference between the maximum and the minimum of the monthly mean of the highest daily temperature. This is the first article focusing on the close relationship between the second peak of epidemic pattern of chickenpox incidence and the variation of temperature within a year.

Chickenpox↗
PubMed2001

Effect of loading on the development of nerve fibers around oral implants in the dog mandible.

Occlusal forces cause stress which morphologically affects the supporting tissues of implants. The aim of this study was to examine the effects of occlusal forces on the distribution of neurofilament protein (NFP)-positive nerve fibers in the tissue of peri-implant bone. The bilateral 2nd, 3rd and 4th mandibular premolars and the 1st molars were extracted from three mongrel dogs. After 4 months of healing, 4 screw-type implants were inserted in the oral cavity. Three months after insertion, the implants on the molar site were loaded by occlusal forces, while those on the premolar site were unloaded. After a further 3 months, the dogs were sacrificed, and specimens were prepared for immunohistochemical NFP-positive staining by the labeled-streptavidin-biotin method. Many NFP-positive nerve fibers were found in the tissues of the loaded site when compared with the unloaded site. These fibers were localized in both the bone marrow space and in the peri-implant fibrous tissue. They had two types of nerve endings: simple free nerve endings, and nerve endings with tree-like ramifications. The present results suggest that loading by occlusal force causes an increase in the number of NFP-positive nerve fibers, many of which have free nerve endings in the peri-implant tissue. The possible role of these NFP-positive nerve fibers is discussed.

Alloys↗
PubMed2001

Vitamin C stimulates sphingolipid production and markers of barrier formation in submerged human keratinocyte cultures.

Human keratinocytes differentiate in vitro in response to a variety of stimuli, but neither the levels nor the spectrum of ceramides approach those seen in vivo. Ceramide production increases when human keratinocytes are grown at an air-liquid interface, and alterations in ceramide content occur when vitamin C is added to air-exposed, organotypic culture systems (Ponec et al. J Invest Dermatol 109:348, 1997). Here, we assessed whether vitamin C stimulates sphingolipid production in human keratinocytes independent of differentiation and air exposure. When submerged, human keratinocytes were grown in 1.2 mM calcium and serum-containing medium with vitamin C (50 microg per ml) for 9 d, total lipid content remained unchanged, but both glucosylceramide and ceramide content increased. Moreover, selected ceramide and glucosylceramide species: i.e., nonhydroxy ceramide 2 and both alpha- and omega-hydroxylated sphingolipids, increased preferentially [ceramide 4 (6-hydroxy-acylceramide), ceramide 5 (alpha-hydroxyceramide), ceramide 6 (4-hydroxy-alpha-hydroxyceramide), and ceramide 7 (6-hydroxy-alpha-hydroxyceramide); and acylglucosylceramide, glucosylceramide-B, and glucosylceramide-D], whereas ceramide 1, ceramide 3, glucosylceramide-C, and sphingomyelin remained unchanged. Synthesis of the corresponding ceramide and glucosylceramide fractions was enhanced by vitamin C, attributable, in part, to increased ceramide synthase activity (over 2-fold, p = 0.01); both serine palmitoyltransferase and glucosylceramide synthase activities remained unaltered. Finally, increased vitamin C-stimulated sphingolipid production correlated with the presence of lamellar bodies with mature internal contents, an increase in covalently bound omega-hydroxyceramide, and the appearance of prominent, corneocyte-bound lipid envelopes, whereas cornified envelope formation was unchanged. Thus, in submerged human keratinocytes, vitamin C induces both increased sphingolipid production and enhancement of permeability barrier structural markers.

Ascorbic Acid↗
PubMed2001

Intravenous low-dose erythromycin administration for infants with feeding intolerance.

BACKGROUND: This study was undertaken to determine the efficacy of low-dose intravenous erythromycin (EM) administration in infants with feeding intolerance. METHODS: The subjects were 26 infants who would not accept enteral feeding within 5 days after birth. Fourteen infants (gestational age: 30.6+/-5.4 weeks and birthweight: 1466+/-825 g) were given EM intravenously at a dose of 1 mg/kg, three times daily (EM group). Doses were increased to 2 mg/kg in five infants who showed a poor response. Twelve infants (gestational age: 30.5+/-5.0 weeks and birthweight: 1317+/-672 g) were observed without EM administration (non-EM group). Blood concentrations of EM at 2 h after administration were measured on 8 (+/-2) days after the start of EM administration in the EM group. RESULTS: Digestive perturbations and intestinal gasless and/or atonic shadows on X-ray findings markedly improved in the EM group soon after the treatment. Comparing the EM group and non-EM group, the postnatal ages at the start of successful enteral feeding were 9.1+/-3.2 days and 14.0+/-4.1 days, respectively (P<0.01). The postnatal ages at feeding of 100 mL/kg per day were 15.2+/-4.0 days and 23.4+/-6.2 days, respectively (P<0.01). The blood EM concentrations of 1 mg/kg and 2 mg/kg were 0.29+/-0.28 microg/mL and 0.57+/-0.20 microg/mL, respectively (P<0.05). No adverse effect on cardiac status or in blood examinations was observed in any infant in the EM group. CONCLUSION: These results suggest that intravenous low-dose EM administration is a useful and safe treatment of feeding intolerance in infants including extremely low-birthweight infants.

Enteral Nutrition↗
PubMed2001

Immunohistochemical and clinicopathologic analysis of response to neoadjuvant therapy for esophageal squamous cell carcinoma.

Recently, neoadjuvant chemotherapy combined with radiation (NAT) has been used in the active treatment of progressive esophageal cancer (T4). However, many patients are resistant to supplemental therapy, and it is necessary to to be aware that side-effects may occur. Accordingly, to minimize adverse reactions and cost, it is important to determine the indications for NAT. We investigated 34 patients with T4 esophageal squamous cell carcinoma and examined the relation between the effects of NAT and immunohistochemical or additional clinicopathologic factors. There was no relation between clinicopathologic factors and immunohistochemical findings (p53 or hsp27 expression), and no clinicopathologic factors showed a relation to a supplemental therapeutic effect. In addition, there was no correlation between p53 staining and therapeutic effects (P=0.734). In contrast, there was a correlation (P=0.0058) between hsp27 staining and therapeutic effect. In conclusion, the usefulness of hsp27 immunostaining in predicting the therapeutic effect of NAT was confirmed in T4 esophageal squamous cell carcinoma.

Adult↗
PubMed2001

Measurement of the maxilla and zygoma as an aid in installing zygomatic implants.

PURPOSE: This study used maxillary and zygomatic measurements to obtain information for installing zygomatic implants. PATIENTS AND METHODS: Angular and linear distances between the maxilla and the zygoma were measured in 12 cadavers (n = 22 sides) classified into short and tall groups by height (140 to 159 cm and 160 to 180 cm, respectively). RESULTS: Based on mean and standard deviation values, the installation angle of zygomatic implants was between 43.8 degrees and 50.6 degrees. The distance between the crest of the maxillary alveolar process near the palate and the jugale (Ju) point of the zygoma was between 44.3 and 54.3 mm. The minimum distance between the most lateral corner of the maxillary sinus and the Ju point was 6.41 mm, and the minimum anteroposterior length of the zygoma was 5.68 mm in the shorter group. CONCLUSIONS: When the installation angle of zygomatic implants is 43.8 degrees or less, perforation of the maxilla and the zygoma or the infratemporal fossa must be avoided. When the angle is 50.6 degrees or more, perforation of the orbital floor must be avoided. Special attention is needed to ensure osseointegration in shorter patients, because the distance between the most lateral corner of the antrum supporting the zygomatic implant and the Ju point is 10 mm or less. The apex of the implant is 3.75 mm in diameter, and the thickness of the zygoma must be 5.75 mm or more. The threads of the implant must not be exposed from the zygoma in shorter patients.

Body Height↗
PubMed2001

Increase of dendritic cells of type 2 (DC2) by altered response to IL-4 in atopic patients.

BACKGROUND: Recent studies have shown that there are 2 dendritic cell subpopulations, DC1 and DC2, which induce T(H)1 and T(H)2 cell differentiation in vitro, respectively. OBJECTIVE: The purpose of this study was to determine whether there exists a deviation of DC1 and DC2 subsets and to investigate their functional abnormalities in T(H)2 cell-mediated atopic diseases. METHODS: We analyzed the frequencies of DC1 (CD11c(+)CD123(-)) and DC2 (CD11c(-)CD123(+)) cells in peripheral blood of atopic patients; we also studied the responses of DC2 cells from atopic patients to IL-3 and IL-4 for their survival. RESULTS: DC2 cells but not DC1 cells were significantly increased in peripheral blood of atopic patients in comparison with that of healthy subjects. DC2 cell numbers were positively correlated with serum IgE levels and blood eosinophil counts, the increase of which reflects T(H)2-type immune response in atopic diseases. IL-4 inhibited IL-3-induced survival of DC2 cells from healthy controls, but IL-4 failed to suppress the IL-3-induced survival of DC2 cells from atopic patients. Furthermore, IL-4 alone enhanced the survival of DC2 cells from atopic patients but not from healthy controls. However, no significant differences were found in the expression levels of activation/maturation markers on DC2 cells between atopic patients and healthy controls. CONCLUSION: These results indicate that DC2 cells are preferentially increased in atopic patients in correlation with the state of atopic allergy and that DC2 cells in atopic patients, unlike those in healthy subjects, exhibit altered responses to IL-4 for survival, suggesting that DC2 cells in atopic patients might contribute to the enhanced T(H)2 cell differentiation in atopic diseases.

Adult↗
PubMed2001

Clinical comparisons between two subsets of gastric antral vascular ectasia.

BACKGROUND: The lesions of gastric antral vascular ectasia take two endoscopic forms, diffuse red spots and red stripes. In addition, they are often associated with cirrhosis. The main aim of the present retrospective study was to determine whether differences in endoscopic appearance and presence or absence of cirrhosis have relationships to clinical features and course. METHODS: Gastric antral vascular ectasia in 30 patients was classified into 2 endoscopic subtypes, punctate type (21 patients) and striped type (8 patients); only 1 patient could not be categorized to either type. The 30 patients were divided into groups based on the presence (25) or absence (5) of cirrhosis. RESULTS: All patients with punctate-type vascular ectasias had cirrhosis, whereas only 38% of patients with the striped type had cirrhosis. All patients without cirrhosis had the striped pattern. For patients with the 2 endoscopic types as well as those with and without cirrhosis, the outcomes of endoscopic treatment were similar. CONCLUSIONS: The findings of the present study suggest that cirrhosis is strongly associated with the development of punctate-type vascular ectasias. The endoscopic appearance of vascular ectasias and the presence or absence of cirrhosis did not determine outcome of patients.

Aged↗
PubMed2001

Relationship between esophageal dysfunction and neuropathy in diabetic patients.

OBJECTIVE: Few studies have compared esophageal dysfunction with diabetic neuropathy, and their relationship is not yet clear. The aim of this study was to investigate the relationship between esophageal function and diabetic neuropathy. METHODS: A total of 59 patients with type 2 diabetes were studied. Long-term ambulatory esophageal pH and motility monitoring were performed. The motor nerve conduction velocity (MCV) and coefficient of variation of R-R intervals (CVRR) were also examined. RESULTS: The 59 patients were classified into four groups: group 1 consisted of patients with both diabetic autonomic neuropathy (DAN) and diabetic motor neuropathy (DMN), group 2 had DMN alone, group 3 had DAN alone, and group 4 had neither DAN nor DMN. In pH monitoring, differences were observed among the four groups in DeMeester score, total number of acid reflux episodes, and % time pH < 4 (p < 0.05). A correlation was observed between % time pH < 4 and MCV; however, no correlation with CVRR was observed. In motility monitoring, differences were observed among the four groups in amplitude of peristaltic waves (p < 0.001), rising velocity of peristaltic waves (p < 0.01), and percentage of effective peristalsis (p < 0.01). A correlation was observed between esophageal motility and MCV; however, no correlation with CVRR was observed. CONCLUSIONS: Esophageal motility disorder and abnormal acid reflux were related to DMN in diabetic patients. A significant correlation was found between esophageal dysfunction and MCV. However, no significant correlation was found between esophageal dysfunction and CVRR.

Aged↗
PubMed2001

[Investigation on zoonosis by disseminating questionnaire to members of medical associations in Kobe and Fukuoka].

With the purpose of studying the involvement of physicians to zoonosis, investigation on the consciousness was performed by disseminating a questionnaire to members of Medical Associations of Kobe City (2,584 members) and Fukuoka City (1,814 members). From the members in Kobe, 1,165 replies were collected (answer ratio: 45.1%) and 774 replies from the members in Fukuoka (answer ratio: 42.7%). About 70-80% of all physicians answering the questionnaire stated that they had examined the patients with infectious diseases at a ratio of less than 10% to a total of patients examined. Among them, 70% of the doctors had asked the patients as to whether or not the patients were keeping pet animals or had traveled overseas recently when infectious diseases was suspected. There were 738 doctors (38.1%) (1,355 cases), who had suspected or made definitive diagnosis on 15 diseases of zoonosis as stipulated in the new Infectious Disease Control Law for the recent 5 years. In all, 365 doctors (18.9%) examined the patients who were suspected to have had an infection from pet animals. The causative animals primarily included dogs, cats, and birds such as parakeet, while monkeys, tortoises, etc. were found in several cases. About one half of the physicians felt that the cases of infectious diseases and zoonosis would increase in the future. In the entry of free opinions relating to the effective measures for the prevention of zoonosis, 712 physicians (39.8%) entered 1,050 proposals. The details of these proposals were: 444 proposals on "administrative measures". 244 on the need of "education" to citizens, and 201 on the importance of "medical management". About 80% of the physicians replied that they would cooperate for the secondary investigation. It appears that the physicians place much expectation on adequate measures against zoonosis. Namely, they expect much on the establishment of a reliable network, i.e. the network of administrative authorities--physicians--veterinarians--pet animal suppliers--pet animal keepers.

Animals↗
PubMed2001

Ileal neobladder for urinary bladder replacement following total pelvic exenteration for rectal carcinoma.

OBJECTIVE: The aim of this study was to determine the feasibility of using the ileal neobladder as a substitute for the urinary bladder following total pelvic exenteration for rectal carcinoma. PATIENTS AND METHODS: Between 1992 and 1998, we performed total pelvic exenteration with ileal neobladder in 5 men with rectal carcinoma. Four patients had primary tumors, and one had recurrent disease after low anterior resection for rectal carcinoma. Histological types were adenocarcinoma in 4 and squamous cell carcinoma in 1. Invaded organs were: the urinary bladder in 1, the urinary bladder and prostate in 2, the prostate and seminal vesicle in 1, and the prostate in 1. RESULTS: There was no operative death. In 1 patient, an ileal conduit was needed because of partial necrosis of the neobladder. Minor leakage on the dorsal wall of the neobladder occurred in 2 patients, which was successfully stopped with simple closure and a gluteus maximus fasciocutaneous flap, respectively. All except one patient with the ileal conduit could void via the urethra. Complete daytime urinary continence was achieved, but nocturnal continence was maintained with voiding once or twice per night. As the urodynamic state, the mean maximum flow rate was 20.9 ml/s (range 9.0-34.1), the mean average flow rate was 7.7 ml/s (range 3.0-11.0), and the mean voided volume was 285.5 ml (range 160-432). The mean length of follow-up was 47.8 months. One patient died of local recurrence 38 months postoperatively, and 1 died of pneumonia 10 months postoperatively. Both patients could void via the urethra until death. The other three patients are currently alive without any evidence of recurrence. CONCLUSIONS: Although total pelvic exenteration is a laborious surgical procedure, an ileal neobladder could be a good alternative to the urinary bladder enabling the patients to void via the urethra with urinary continence.

Adenocarcinoma↗
PubMed2001

Triggering the induction of myofibroblast and fibrogenesis by airway epithelial shedding.

Myofibroblasts have been thought to participate in subepithelial fibrosis in asthma, but the mechanism of myofibroblast induction has not been fully understood. In this study we investigated injury-related myofibroblast induction in a coculture system of guinea-pig epithelial cells and fibroblasts cocultured in a human amnion chamber. After pseudostratified epithelial cells were mechanically scraped, migrated flat epithelial cells differentiated into cuboidal appearances on Day 4 and then returned to their original shapes on Day 8. During the course of the epithelial redifferentiation, it was found by Northern blot analysis, immunohistochemistry for alpha-smooth muscle actin, and electron microscopic observation that the myofibroblasts were transiently induced on Day 4. The myofibroblast induction was inhibited by the blocking of transforming growth factor (TGF)-beta1 and thrombospondin (TSP)-1, indicating that the activation of TGF-beta1 by TSP-1 would induce myofibroblasts. This finding was also supported by a transient upregulation of TSP immunoreactivity and TSP-1 messenger RNA (mRNA) in fibroblasts. Interestingly, epithelial injury reduced TGF-beta1 immunoreactivity in the amnion membrane but did not affect TGF-beta1 mRNA in epithelial cells and fibroblasts, indicating that TGF-beta1 supplied from the extracellular matrix can participate in myofibroblast induction. Concurrently with myofibroblast induction, procollagen type I and III mRNAs were upregulated in fibroblasts, and obvious collagen deposition was observed ultrastructurally around the myofibroblasts compared with the fibroblasts. These results indicate that induced myofibroblasts can be functionally more active in producing collagen than are resting fibroblasts. The present study suggests that epithelial injury stimulates TGF-beta1 release from the extracellular matrix and its activation via TSP-1 production, causing collagen synthesis through myofibroblast induction.

Actins↗