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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 325 records · Page 18Linked to original sources

Correlation between tumor angiogenesis and expression of thymidine phosphorylase, and patient outcome in uterine cervical carcinoma.

The relationship between tumor angiogenesis and the expression of thymidine phosphorylase (dThdPase) in uterine cervical carcinoma tissues, as well as patient outcome, were investigated. Primary tumor specimens surgically obtained from 54 patients (stages Ib to IIIb) receiving neither chemotherapy nor radiation therapy before surgery were examined. Intratumoral microvessel density (IMVD) and dThdPase expression were evaluated immunohistochemically using anti-CD34 and anti-dThdPase antibodies and were correlated with clinicopathologic parameters and prognosis. IMVD for the 54 tumors ranged from 24.8 to 118.6, with a median value of 57.7 (number/0.7386 mm2/field). For immunoreactivity of dThdPase, 16 tumors were graded as -, 20 as 1+, and 18 as 2+. IMVD was significantly associated with the expression of dThdPase (P<.01). Both IMVD and dThdPase expression were well correlated with depth of myometrial invasion, endometrial invasion, and pelvic lymphnode metastasis (P<.05). Overall survival rates for 18 patients with strong dThdPase-staining tumors, assessed as 2+, were lower than those for 36 with weak dThdPase staining tumors (P = .0108). However, there was no statistical correlation between IMVD and patient outcome. The expression of dThdPase plays a role in the promotion of angiogenesis and affects the patient's survival in uterine cervical carcinomas.

Antigens, CD34↗

Expansion of helper T-cell recognition in mice immunized with a synthetic peptide corresponding to the C-terminal thyrotropin receptor-specific insert.

We previously reported that immunization with a synthetic peptide of human thyrotropin receptor (TSH-R) expanded humoral autoimmunity to TSH-R (Sugawa H, Ueda Y, Ueda M, Kosugi S, Ichiyama S, Mori T. Immunization with the 'immunogenic Peptide' of TSH receptor induces oligoclonal antibodies with various biological activities. Peptide 1998;19:1303-7.). In the present study, we examined this phenomenon at the T-cell level. Balb/c mice were immunized with a synthetic peptide corresponding to the C-terminal-specific insert of human TSH-R. Spleen cells were collected and subjected to antigen-specific ELISPOT assay. The number of interleukin 4-secreting cells specific to P354-367 increased within 3 weeks. Cells responding to the other peptides increased 7 weeks after immunization. This phenomenon was not observed in mice immunized with bovine serum albumin alone. During immunization, numbers of interferon-gamma-secreting lymphocytes were not changed significantly. These results indicated that immunization with C-terminal TSH-R-specific insert peptide causes fluctuation in the type 2 helper T-cell population but not type 1 Th cells against the TSH-R, and the recognition repertoire of type 2 helper T cell was expanded by the peptide.

Animals↗

Ultrastructural study on adhesions in internal derangement of the temporomandibular joint.

PURPOSE: This study examined the ultrastructural characteristics of adhesions in the upper joint compartment of temporomandibular joint (TMJ). MATERIALS AND METHODS: Tissue biopsy specimens of adhesions were obtained during arthroscopic operation on 36 joints in 22 patients with internal derangement (ID). The biopsy specimens were examined by light and transmission electron microscopy. RESULTS: Adhesions were grossly divided into two types based on arthroscopic observation: 1) a band-like type, which connected the articular fossa and TMJ disc, and 2) a pseudowall-like type, which faced the synovial fluid and was lined by articular tissue. Two types of collagen arrangement were observed at the electron microscopic level: orderly arranged collagen bundles and randomly arranged collagen bundles. Orderly arranged collagen bundles were prominent in the band-like adhesions. In pseudowall-like adhesions, mainly the randomly arranged collagen bundles were seen. However, in some dense fiber parts, orderly arranged collagen bundles also were observed. In other pseudowall-like adhesions, only orderly arranged collagen bundles were seen. Elastic fibers were abundant in some pseudowall-like adhesions with randomly arranged collagen bundles. There were no elastic fibers in the band-like adhesions, some dense fiber parts of the pseudowall-like adhesion, pseudowall-like adhesions consisting of only orderly arranged collagen bundles, and in the synovial membrane. CONCLUSION: The different arrangement of collagen fibers and presence or absence of elastic fibers were observed in the two types of adhesions. These findings served to show that extracellular components correspond to a dysfunction involving an ID of TMJ.

Adult↗

Increased intracellular Ca2+ concentration in the hippocampal CA1 area during global ischemia and reperfusion in the rat: a possible cause of delayed neuronal death.

The crucial role of free cytosolic Ca2+ in ischemic neuronal damage has been studied in recent years. In the present report, changes in the intracellular Ca2+ concentration in the hippocampal CA1 area during transient global ischemia and reperfusion were measured using in vivo Ca2+ fluorometry with fura-2 in the four-vessel occlusion and reperfusion model in halothane-anesthetized rats. Marked changes were seen during 10-min global ischemia, with the intracellular Ca2+ concentration increasing gradually following application of the ischemic insult and rapidly about 2 min after the beginning of ischemia, and continuing to increase until reperfusion. On reperfusion, the intracellular Ca2+ concentration began to decrease and returned to the pre-ischemic level within 15 min. Induction of severe global ischemia was confirmed by the complete suppression of synaptic activity and the decrease in hippocampal temperature in the CA1 area. After seven days, CA1 pyramidal cell loss was observed histopathologically in the same rats which had undergone measurement of the intracellular Ca2+ concentration changes. In the present study, a temporal profile of the free cytosolic Ca2+ dynamics during ischemic and early post-ischemic period was determined in vivo. The results demonstrate that the intracellular Ca2+ concentration in the hippocampal CA1 area is transiently and markedly increased during a brief ischemia-inducing delayed neuronal death, implying that Ca2+ overload during cerebral ischemia is a possible cause of the delayed cell death of CA1 pyramidal neurons.

Animals↗

Skin cancer screening in Okinawa, Japan.

Depletion of the ozone layer has been observed on a global scale. Ozone depletion increases the amount of biologically harmful solar ultraviolet radiation (UV) that reaches the surface of the Earth, leading to an increased incidence of skin cancer. We previously reported the prevalence and incidence of actinic keratosis (AK) in Kasai City, which is located almost at the center of Japan. To evaluate the effects of different ambient annual UV doses on the prevalence and incidence of non-melanoma skin cancer and AK in Japan, we screened for skin cancer on Ie Island in Okinawa at the southern end of Japan, where the annual cumulative dose of UV is assumed to be the highest in Japan. The island had a population of 5562 in 1993. A prospective 4-year population-based study on the prevalence and incidence of cutaneous neoplasms was conducted by examining the sun-exposed skin of people over 40 years of age living on Ie Island. In 1993 1996, 86 cases of AK, nine of basal cell carcinoma (BCC), and two of squamous cell carcinoma were identified. The annual prevalence of AK on Ie Island was 1159.4 in 1993, 572.8 in 1994, 1014.3 in 1995 and 988.9 per 100000 Japanese in 1996. These values were significantly higher than those in Kasai City. The annual age-adjusted odds ratios for AK of Ie Island to Kasai City were 2.79, 1.38, 2.45 and 2.39, respectively. The incidences of AK on Ie Island per 100,000 were 637.0 in 1995 and 625.5 in 1996, which were also significantly higher than those in Kasai City (223.6 in 1993 and 171.2 in 1994). The prevalence of BCC was 123.6 and the incidence was 26.1. Together with our previous reports, the present results show a possible inverse relationship between the prevalence and incidence of AK and latitude among Japanese people.

Adult↗

Induced expression of p16 and p21 proteins in UVB-irradiated human epidermis and cultured keratinocytes.

It has been suggested that p16INK4a, the product of the cyclin-dependent kinase inhibitor 2 or multiple tumor suppressor 1 gene, prevents phosphorylation of the retinoblastoma gene product, and thus acts as a negative cell cycle regulator. To elucidate an effect of ultraviolet B (UVB) radiation on p16 expression and its relation to p21, and proliferating cell nuclear antigen (PCNA), immunohistochemical and western blot analyses were performed on UVB-irradiated normal human epidermis and cultured keratinocytes, respectively. Little p16 protein was seen in the control epidermis or keratinocytes. Increases in the levels of p16 protein in both UVB-irradiated epidermis and keratinocytes occurred in a similar manner, in which p16 was induced at 24-48 h and peaked at 72-120 h after irradiation. The induced expression of p21 was observed relatively earlier than that of p16, with peaked expression at 24-48 h and a return to control level by 168 h. PCNA expression was increased slightly until 48 h but significantly increased during 48-168 h of post-irradiation with peak expression at 72 h. These results indicate that together with p21, p16 protein may play an important role for protective or adaptive response to UVB exposure of human skin.

Adult↗

Application of titanium-alloy endodontic implants in conjunction with periradicular surgery.

OBJECTIVE: To evaluate the outcome of placement of titanium-alloy endodontic implants in conjunction with periradicular surgery. STUDY DESIGN: Twenty-four teeth were treated with endodontic implants with corresponding periradicular surgery by using SuperEBA cement (Harry J Bosworth Co, Skokie, Ill) as a sealer. The results of the endodontic implant surgery were evaluated clinically and radiographically from 2 to 4 years after treatment. RESULTS: Twenty-two teeth were treated successfully, whereas 2 teeth were treated unsuccessfully, for a success rate of 92%. CONCLUSIONS: Titanium-alloy endodontic implants in conjunction with periradicular surgery may provide good short-term results. Sealing between the endodontic implant and the dentin is likely an important factor for success.

Adult↗

Autogenous bone grafts in the rabbit maxillary sinus.

OBJECTIVE: This study involving rabbits was undertaken to establish an experimental model for the sinus lift procedure and to clarify the repair of autogenous grafted bone in the maxillary sinus. STUDY DESIGN: A corticocancellous bone block was grafted into the maxillary sinus of each of 18 rabbits. Each animal was killed at 2, 4, or 8 weeks after grafting and then histologically evaluated. RESULTS: At 2 weeks, new bone formation was observed. There was no inflammation of the antral membrane. At 4 weeks, lamellar structures were observed in newly formed bone. At 8 weeks, newly formed cortical bone was observed under the elevated membrane and the medullary cavity was almost completely occupied by fat cells. CONCLUSIONS: There were no histologic complications after the sinus lift procedure. Histologic results indicated that newly continuous cortical bone was formed along the elevated membrane at 8 weeks. This animal model could be useful as a sinus lift model.

Animals↗

Trends in site-specific mortality from oral and pharyngeal cancer among Japanese males, 1950-94.

In order to obtain some etiological clues for oral and pharyngeal cancer in Japanese males, we examined mortality trends from cancer of the lip, buccal cavity and pharynx by site with other descriptive epidemiological features (1950-94). The data were obtained from Vital Statistics (Ministry of Health and Welfare, Japan). The 45-year trend in mortality was evaluated by computing crude and age-adjusted mortality rates, age-specific mortality rates, with birth cohort analysis. The crude mortality rate from cancer of the lip, buccal cavity and pharynx has increased by 3.7-fold, and age adjusted mortality rate by 1.7-fold in the 45-year period, with different mortality trends by site. In general, age-specific mortality has also been increasing with advancing age. The birth cohort analysis showed that the higher the mortality rate, the younger the birth cohort, but with different effects of birth cohort by site. Mortality from cancer of the lip, buccal cavity and pharynx has consistently been increasing in Japanese males from 1950 to 1994, with similar upward mortality trends for some specific sites.

Adult↗

Sarcomatous overgrowth in recurrent ameloblastic fibrosarcoma.

A case of recurrent ameloblastic fibrosarcoma (AFS) in the mandibular molar region of a 22-year-old male is reported. The tumor was first diagnosed as a sarcoma of undetermined origin, because the benign epithelial component of AFS had disappeared after repeated surgical procedures. The lesion grew rapidly in the time from hospital admission until operation, suggesting progression from low to high malignancy. The correlation between the benign epithelial component and malignancy is discussed.

Adult↗

Construction of an autonomously replicating plasmid in n-alkane-assimilating yeast, Candida tropicalis.

A transformation system using the autonomously replicating plasmid in the n-alkane-assimilating and asporogenic diploid yeast, Candida tropicalis, was developed. For the cloning of a DNA fragment containing a potential autonomously replicating sequence (ARS) from the genomic DNA of C. tropicalis, the ura3 mutant obtained using ethylmethane sulfonate as the host and the URA3 gene amplified by PCR using the C. tropicalis genomic DNA as a selectable marker were prepared. Comparison of ARSs among yeasts revealed that the consensus sequence found in S. cerevisiae was also present in C. tropicalis. The autonomously replicating plasmid containing the putative ARS as the shuttle vector, capable of replicating in both E. coli and C. tropicalis, was first constructed. The transformation system using this plasmid, in addition to the integrative transformation system, will be applicable to genetic studies of C. tropicalis.

Journal Article↗

Production of transgenic rats using cryopreserved pronuclear-stage zygotes.

We investigated the application of cryopreserved pronuclear-stage zygotes for the production of transgenic rats. Most of the pronuclear-stage zygotes cryopreserved by conventional two-step freezing or vitrification appeared morphologically normal, but the proportion of frozen zygotes that developed into fetuses following transfer (59.7-60.2%) was higher than that of vitrified zygotes (5.5-22.1%). When the frozen-thawed zygotes were used for DNA microinjection, 97.5% survived after DNA microinjection and 25.1% of the transferred zygotes developed into fetuses. These proportions were comparable to those of the fresh control zygotes (97.0 and 30.0%, respectively). The integration efficiency of the exogenous DNA into fetuses was similar between the frozen group (3.3% per injected zygote) and the control group (3.5%). These results indicate that pronuclear-stage rat zygotes can be successfully cryopreserved by conventional two-step freezing for production of transgenic rats.

Animals↗

Administration of G-CSF to normal individuals diminishes L-selectin+ T cells in the peripheral blood that respond better to alloantigen stimulation than L-selectin- T cells.

To determine whether administration of G-CSF induces phenotypic or functional changes in T cells, we examined peripheral blood T cells from normal individuals receiving G-CSF for activation antigen and adhesion molecule expression before and after G-CSF administration. G-CSF (10 microg/kg/day) was administered subcutaneously to 14 normal individuals for 3-5 days and their PBMC were serially analyzed with monoclonal Ab (mAb) directed to HLA-DR, CD45RO, CD45RA, CD25, CD122, CD95, CD11a, CD49d, CD44 and CD62L (L-selectin) coupled with anti-CD3 mAb. Among T cells positive for these antigens, only the proportion of T cells expressing L-selectin significantly decreased from 68% to 37% after 3-day G-CSF administration. When peripheral blood CD3+ T cells obtained before and after G-CSF administration were sorted into two populations depending on the expression of L-selectin and tested for their proliferative response to allogeneic B cells, the reactivity of L-selectin- cells to alloantigen stimulation was consistently lower than that of L-selectin+ cells regardless of the exposure to G-CSF. The decrease in the relative number of L-selectin+ cells induced by G-CSF administration may contribute to the unexpectedly low incidence of severe acute GVHD after allogeneic PBSC transplantation.

Granulocyte Colony-Stimulating Factor↗

Overexpression of the human homologue of Drosophila patched (PTCH) in skin tumours: specificity for basal cell carcinoma.

The human homologue of the Drosophila segment polarity gene patched (PTCH) has been identified as the gene for the naevoid basal cell carcinoma (BCC) syndrome and has also been shown to be mutated in sporadic BCC. In order to elucidate the specificity of the PTCH abnormality in BCC, we examined normal skin and 12 BCC and 24 other types of tumour from Japanese patients for expression of the PTCH transcript by competitive reverse transcription-polymerase chain reaction, as mutational inactivation of PTCH leads to overexpression of the mutant transcript owing to failure of a negative feedback mechanism. We found a high level of PTCH expression in all 12 BCCs, while 23 of the other tumours and four specimens of normal skin showed no or weak expression of the gene, with the exception of one specimen from a patient with Bowen's disease which had high expression. These results indicate that the PTCH abnormality plays a critical role in the pathogenesis of BCC.

Aged↗

Higher susceptibility to apoptosis following ultraviolet B irradiation of xeroderma pigmentosum fibroblasts is accompanied by upregulation of p53 and downregulation of bcl-2.

Apoptosis plays an important part as a defence mechanism in eliminating damaged cells. Among the complex factors which regulate apoptosis, the p53 tumour suppressor protein which is induced by DNA damage has been suggested to play a crucial part. Cells from xeroderma pigmentosum (XP) patients, which are defective in nucleotide excision repair, express higher levels of p53 and are highly susceptible to cell death after ultraviolet (UV) irradiation. To examine the relationships between DNA damage, p53 and apoptosis, normal and XP group A fibroblasts were exposed to UVB, and expressions of molecules involved in apoptosis were examined. Apoptosis of XP and normal cells was clearly detected at 48 h after irradiation with UVB at doses of 5 and 40 mJ/cm2, respectively. Cells were positive by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) staining under these exposure conditions. At 6 h after irradiation, p53 protein expression was induced in normal and XP cells at minimal doses of 10 and 2.5 mJ/cm2, respectively. Bcl-2 protein, an inhibitor of apoptosis, was downregulated prior to cell death following UVB exposure at doses that induced apoptosis in both cell types. These results suggest that DNA damage due to UVB induces apoptosis by upregulating proapoptotic molecules such as p53, and by downregulating anti-apoptotic molecules such as Bcl-2.

Apoptosis↗