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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 361 records · Page 20Linked to original sources
PubMed1998

Isolation of nucleation-competent centrosomes from Dictyostelium discoideum.

The centrosome of Dictyostelium discoideum is a box-shaped, layered core structure surrounded by a corona which is made up of dense nodules embedded in amorphous material. It is also known as nucleus-associated body. Because of its tight association with the nucleus the centrosome has resisted so far all attempts for isolation in sufficient purity and quantity for biochemical analysis. Here we report on the large-scale isolation of D. discoideum centrosomes after treatment of nucleus-centrosome complexes with a buffer containing sodium pyrophosphate. Following heparin treatment and a filtration step, centrosomes were further purified by density gradient centrifugation. Immunofluorescence analysis of the isolated centrosomes revealed the presence of the D. discoideum 350-kDa antigen, a centrosomal marker protein, gamma-tubulin, and the D. discoideum homologues of pericentrin, Spc110p, and Cdc31p. The structural integrity of the isolated centrosomes was demonstrated by confocal laser microscopy and electron microscopy. Microtubule nucleation assays with purified pig brain tubulin showed that the isolation procedure did not only preserve the structure but also the functionality of the isolated centrosomes. D. discoideum centrosomes should now become an attractive new model system in addition to, and for comparison with, centriolar centrosomes and yeast spindle pole bodies.

Animals↗
PubMed1998

Immunization with the "immunogenic peptide" of TSH receptor induces oligoclonal antibodies with various biological activities.

Balb/c mice were immunized with a synthetic peptide (P354-14) corresponding to "the immunogenic peptide" of human thyrotropin receptor (hTSH-R). Through screening for binding to the peptide, we obtained several monoclonal antibodies with various biological activities: thyroid stimulation (SAb), inhibition of TSH stimulation (BAb) and no significant effect on cAMP production. One of the stimulatory clones was further studied. This clone enhanced cAMP production in Cos-7 cells transformed with the truncated TSH-R cDNA deleting the immunogenic peptide. These results indicated that the immunogenic peptide of the TSH-R induces oligoclonal anti-TSH-R antibodies, although the region is not essential for the functional epitope.

Animals↗
PubMed1998

Segmental mandibular reconstruction by distraction osteogenesis under skin flaps.

In five adult dogs, molars were extracted and skin flaps from the neck prepared for delayed transplantation. Two weeks later, a 25-mm segment of the mandible was excised with surrounding periosteum and gingiva. The mandible was stabilized with a reconstruction plate and the intraoral defect repaired with a pedicled skin flap. A proximal transport segment was created and an external distraction device was applied. After one week, distraction of the transport segment was begun at a rate of 1 mm/day. After distraction was completed, the lengthening appliance was left in place for 12 weeks until the dogs were killed. Radiologic and histologic examination revealed new bone at the distraction site. The intraoral skin flap was pushed out of the defect as distraction progressed. Bony union of the transport segment to the distal stump was not achieved due to intervening soft tissue. These results suggest that it is feasible to bridge a mandibular defect that is covered with a skin flap, with distraction osteogenesis.

Animals↗
PubMed1998

Influence of food consistency and dental extractions on the rat mandibular condyle: a morphological, histological and immunohistochemical study.

The purpose of this study was to investigate the relationship between food consistency and the growth of the mandibular condyle in rats. Secondly, the effect of dental extractions on cartilage of the mandibular condyle was examined in young adult rats fed foods of varying consistency. Thirty-six male Wistar rats were divided into four groups: (A) Solid diet--non-Extraction (non-Ext.) group; (B) Solid diet--Extraction (Ext.) group; (C) Powder diet--non-Ext. group; and (D) Powder diet--Ext. group. Extractions were performed at 12 weeks of age. The mandibular condyles were removed at 1, 4, and 8 weeks after the extractions. The shape of the mandibular condyles in the powder diet groups (C and D) was significantly narrower. In the Ext. groups (B and D), the thickness of the hypertrophic zone was reduced one week after the extractions. In the powder diet groups (C and D), the intensity of the staining of fibronectin decreased in the proliferative zone regardless of the extractions. In group B, a decreased intensity of this reaction was observed one week after the extractions. From these results, it appeared that food consistency and/or dental extractions affected the morphology of the mandibular condyle and the histological characteristics of the mandibular condylar cartilage.

Age Factors↗
PubMed1998

Cervicothoracic approach for total mesoesophageal dissection in cancer of the thoracic esophagus.

BACKGROUND: The clinical significance of lymph node involvement along the recurrent laryngeal nerves in cancer of the thoracic esophagus is still controversial. Although these lymph nodes are anatomically located in a well-defined compartment (proximal mesoesophagus), appropriate procedures for dissecting them are not well established. STUDY DESIGN: We retrospectively investigated clinical results over the past 10 years in 276 patients who underwent systematic dissection of cervical, mediastinal, and upper abdominal lymph nodes. We routinely performed the cervical procedure before thoracotomy for total dissection of the proximal mesoesophagus and to minimize the operative risk. RESULTS: All macroscopically recognizable lesions were resected in 94% of the patients. The hospital mortality rate was 2.5%. Recurrent nerve palsy developed in 59 patients, but it was successfully managed without prolonged hoarseness in 50 of them. The recurrent nerve node group was most frequently involved (frequency of 25% in superficial cancer, 57% in non-superficial cancer). Supradiaphragmatic lymph node involvement was limited to the recurrent nerve nodes in 25% of the patients with positive supradiaphragmatic node. The 5-year survival rate in patients with positive recurrent nerve nodes was 34%. CONCLUSIONS: Dissection of the recurrent nerve lymph nodes is essential for curative esophagectomy even in the early phase of cancer invasion. Our cervicothoracic approach for total dissection of the proximal mesoesophagus yielded acceptable outcomes.

Carcinoma, Squamous Cell↗
PubMed1998

Peri-implant soft tissue management through use of cultured mucosal epithelium.

OBJECTIVE: In implant therapy, peri-implant soft tissue management through use of mucosal grafting or skin grafting is necessary in some patients who do not have enough attached gingiva around the abutment. However, limitation of donor site size is a problem for the mucosal graft, and the different characteristics of skin, such as hair growth, are disadvantages in treatment that involves the use of skin graft. On the other hand, cultured epithelium fabricated with living mucosal cells has proved to be a good grafting material for any kind of mucosal defect. In this study, we used cultured mucosal epithelium for soft tissue management in implant therapy. STUDY DESIGN: In the first surgical procedure of the implant therapy, a small segment of oral mucosa was sampled from a patient. The cultured epithelium was fabricated and then stored until it was grafted in the second surgery. RESULTS: Twelve cases in which patients underwent peri-implant soft tissue management through use of cultured mucosal epithelium for implant therapy are presented, and the usefulness of this technique in the making of attached gingiva is analyzed. CONCLUSIONS: From this study it was concluded that cultured mucosal epithelium can serve as a proper material for peri-implant soft tissue management.

Aged↗
PubMed1998

New superselective intra-arterial infusion via superficial temporal artery for cancer of the tongue and tumour tissue platinum concentration after carboplatin (CBDCA) infusion.

We developed a new technique of superselective intra-arterial chemotherapy for tongue cancer using a modified (1.35 mm) angiographic catheter. The catheter was confirmed to be inserted into the lingual artery by the new technique. We measured the platinum concentrations in resected tumour tissues after infusion of carboplatin (CBDCA) at 20 mg/m2 over 30 min from 30 min before tumour resection in 12 patients with cancer of the tongue (6 patients: superselective intra-arterial infusion; 6 patients: conventional intra-arterial infusion). The mean platinum concentration in tumour tissue was 10.5 +/- 1.2 micrograms/g wet, which was more than twice higher than, and significantly different from, 4.3 +/- 3.8 micrograms/g wet by the conventional intra-arterial infusion method. This new superselective intra-arterial infusion method allows direct infusion of the anticancer agent into the artery supplying the tumour and is expected to become a new therapeutic modality for cancer of the tongue.

Antineoplastic Agents↗
PubMed1998

The effect of hyperbaric oxygen treatment on bone tissue reactions to c.p. titanium implants placed in free autogenous bone grafts. A histomorphometric study in the rabbit mandible.

This study aimed to investigate the effect of hyperbaric oxygen (HBO) therapy on the tissue reactions to commercially pure (c.p.) titanium implants placed in free autogenous bone graft by a 1-stage procedure. Eighty c.p. titanium implants were placed in the bone grafted from iliac crest to bilateral mandible of 40 Japanese white rabbits without tapping. Twenty rabbits underwent daily a HBO treatment for 60 min under 2.4 ATA during 20 consecutive days and the other untreated 20 rabbits served as controls. The implants with surrounding bone tissue were retrieved 20, 30, 60, 90 and 120 days after surgery, fixated, dehydrated and embedded in resin. About 20 microns thick ground sections were prepared prior to microscopical observations. The bone area and the bone-to-implant contact inside the threads were calculated separately in the grafted bone and in the host bone for each implant. After 30 and up to 120 days, the HBO treated group showed more bone-to-implant contacts in the grafted bone as compared to the non-HBO treated group. In the host bone there were no differences observed between HBO and non-HBO treated groups. This study indicated that HBO treatment was beneficial for the tissue incorporation of c.p. titanium implants when placed immediately in free autogenous bone grafts.

Animals↗
PubMed1998

Immunoreactivity of alpha-melanocyte-stimulating hormone, adrenocorticotrophic hormone and beta-endorphin in cutaneous malignant melanoma and benign melanocytic naevi.

Melanocyte-stimulating hormone (MSH) has been reported to enhance the experimental metastatic behaviour of melanoma cells in the mouse model. alpha-MSH production and MSH receptor (melanocortin 1 receptor gene) expression have been detected in cultured normal human melanocytes and metastasized melanomas. The exact role of MSH in the metastatic behaviour of human melanoma cells is, however, not yet known. To clarify a possible role of proopiomelanocortin (POMC)-derived peptides, including alpha-MSH, in melanoma development and progression, we analysed immunohistochemically the localization of alpha-MSH adrenocorticotrophic hormone (ACTH) and beta-endorphin in various kinds of benign pigmented naevocytic lesions and malignant melanomas. Three of 21 samples of common and dysplastic naevi showed detectable alpha-MSH staining in naevus cells, and five and six of 15 samples were weakly positive for ACTH and beta-endorphin staining, respectively. In melanoma samples, 24 of 45, 23 of 39 and 30 of 42 samples showed positive staining with alpha-MSH, ACTH and beta-endorphin antibodies, respectively. Furthermore, staining for all three antibodies was noted to be more intense and diffuse in samples of nodular melanoma, vertically growing acral lentiginous melanoma and superficial spreading melanoma as well as metastatic lesions compared with those of naevi. Although it is yet to be determined whether or not this strong staining for POMC-derived peptides in advanced melanoma cells indicates a role of autocrine or paracrine regulation, our results suggest a possible involvement of POMC gene products in melanoma progression.

Adrenocorticotropic Hormone↗
PubMed1998

Detection of anti-type VII collagen antibody in Sjögren's syndrome/lupus erythematosus overlap syndrome with transient bullous systemic lupus erythematosus.

Bullous systemic lupus erythematosus (SLE) is a chronic, widespread, non-scarring, subepidermal blistering eruption associated with autoimmunity to type VII collagen. We describe a patient with Sj ogren's syndrome/lupus erythematosus overlap syndrome who showed transient blistering eruptions over limited skin surface and in oral mucosa. At the time of aggravation, the patient's serum contained IgG autoantibodies that bound to the dermal side of 1 mol/L NaCl-split normal skin, as determined by an indirect immunofluorescence test, and that reacted to type VII collagen, as determined by immunoblotting on dermal extract. Our observations suggest that a chronic, widespread, blistering eruption is not a prerequisite for the diagnosis of bullous SLE, and a mild, transient, blistering eruption could be a manifestation of type I bullous SLE.

Adult↗
PubMed1998

Pathophysiological response of cytokines and vasoactive agents in patients undergoing total gastrectomy.

OBJECTIVE: To investigate the involvement of vasoactive agents, endothelin (ET)-1, and atrial natriuretic peptide (ANP), and the responses of cytokines in patients undergoing total gastrectomy. DESIGN: Prospective study. SETTING: University hospital, Japan. SUBJECTS: 20 patients with advanced gastric cancer who had undergone total gastrectomy with lymph node dissection. INTERVENTIONS: Serum or plasma samples collected on the day before the operation, at the time of skin closure, and on postoperative days 1, 3, 5, and 7. MAIN OUTCOME MEASURES: Concentrations of acute phase reactants, cytokines (interleukin (IL)-1, tumour necrosis factor (TNF) and interleukin (IL)-6), and vasoactive agents (ET-1 and ANP). RESULTS: There were significant increases in concentrations of IL-6 and acute phase reactants postoperatively. ET-1 and ANP concentrations did not change significantly. CONCLUSION: There was no correlation between concentrations of the vasoactive agents ET-1 and ANP, and those of acute phase reactants or cytokines in serum or plasma in patients undergoing total gastrectomy.

Acute-Phase Proteins↗
PubMed1998

A monoclonal antibody, HCL-2, raised against human luteal cells reacts with apolipoprotein-B and detects the uptake of low density lipoprotein by luteinizing granulosa cells.

A monoclonal antibody, HCL-2, was raised by immunizing mice against human luteal cells. HCL-2 reacted with luteal cells and villous trophoblasts. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis profile of immunopurified antigens from corpus luteum, chorionic villi, and placenta showed the same main protein band, the molecular mass of which is >200 kDa. The sequence of a portion of the N-terminal region of the antigenic protein purified from placenta was identical to that of apolipoprotein-B. The antigen purified from human serum and low density lipoprotein (LDL) using HCL-2 showed the same protein band as that from corpus luteum. Furthermore, the amino acid sequence (20 amino acids) of the protein purified from serum was also identical to that of apolipoprotein-B. Thus, we concluded that HCL-2 antigen is apolipoprotein-B. Human luteinizing granulosa cells isolated from the patients undergoing in-vitro fertilization treatment were cultured in the medium containing lipoprotein-deficient serum with or without supplementation of LDL. Using HCL-2, apolipoprotein-B was immunocytochemically detected on granulosa cells only in the presence of LDL. These findings showed that the uptake of LDL by granulosa cells was detected by immunocytochemical staining of apolipoprotein-B, indicating that HCL-2 is useful for analysing dynamic utilization of LDL by ovarian cells.

Adult↗
PubMed1998

Human large luteal cells in the menstrual cycle and early pregnancy express leukotriene A4 hydrolase.

Leukotriene (LT) A4 hydrolase (EC3.3.2.6) converts LTA4 to LTB4 which shows a chemotactic activity to leukocytes. To investigate the involvement of LTB4 in human corpus luteum (CL) function, the localization of LTA4 hydrolase in human ovarian tissues was examined by immunohistochemistry with a rabbit polyclonal antibody against LTA4 hydrolase. The enzyme was weakly expressed on granulosa cells of the follicles. After ovulation, the intensity of LTA4 hydrolase on large luteal cells increased and was highest in the midluteal phase. High expression was also observed in the CL of early pregnancy. In theca interna and small luteal cells, LTA4 hydrolase was weakly detected in all developmental stages. Immunoblot analysis demonstrated that the molecular mass of LTA4 hydrolase expressed in CL was 62 kDa, and confirmed that LTA4 hydrolase expression increased during CL formation and remained high in early pregnancy. The sequence encoding mRNA of LTA4 hydrolase, which was isolated from CL and amplified by polymerase chain reaction, was shown to be identical to the previously reported one. Immunocytochemistry showed that LTA4 hydrolase expression in cultured granulosa cells increased over 4 days in vitro and was enhanced by human chorionic gonadotrophin treatment. These expression profiles of LTA4 hydrolase suggest the involvement of LTB4 in luteal cell function during CL formation and early pregnancy.

Adolescent↗
PubMed1998

Human pancreatic RNase1-human epidermal growth factor fusion: an entirely human 'immunotoxin analog' with cytotoxic properties against squamous cell carcinomas.

The gene encoding human pancreatic ribonuclease 1 (hpRNasel) was fused with a gene encoding human epidermal growth factor (hEGF). The hybrid human protein was isolated from Escherichia coli inclusion bodies, refolded and purified to homogeneity. The fusion protein competed with 125I-hEGF for binding to hEGF receptors (EGFR) and had ribonucleolytic activities approaching those of hpRNase1. Several conformations having different enzymatic activities could be detected after reversed-phase high-performance liquid chromatographic analysis, the less hydrophobic molecules being the most active. The hybrid protein was specifically cytotoxic to A431, an EGFR overexpressing squamous carcinoma cell line, with an IC50 of approximately 10(-7) M. In contrast, recombinant hpRNase1 had an IC50 higher than 10(-4) M. A mixture of free hEGF and free hpRNasel was not more cytotoxic than hpRNasel alone and no cytotoxicity was detected in EGFR-deficient control cells. Taken together, these data suggest that this construct might be useful for targeted therapy of esophageal, lung and other squamous cell carcinomas and also breast cancers overexpressing EGFR, which correlate with a poor prognosis and cannot be cured by surgery alone. Engineering hybrid molecules with endogenous human proteins for targeted therapy may alleviate the dose-limiting immunogenicity and toxicity of conventional immunotoxins.

Binding, Competitive↗
PubMed1998

Basal cell carcinoma cells resemble follicular matrix cells rather than follicular bulge cells: immunohistochemical and ultrastructural comparative studies.

To detail the histogenetic relationship between basal cell carcinoma (BCC) and hair follicles, we immunohistochemically compared BCC cells to follicular matrix cells and follicular bulge cells using a panel of monoclonal antibodies against melanocytes, cytokeratins, subepidermal extracellular matrix components, and bullous pemphigoid (BP) sera, as well as using electron microscopy. Cytokeratin expression patterns were not consistent with the variety in types of cytokeratins and in cases of BCC. The distribution of some extracellular matrix components was not only linear along the interfaces of BCC tumor nests and stroma, and follicular matrix and follicular papilla; granular deposits were also seen in the stroma and follicular papilla, whereas they were only linearly distributed along the follicular bulge. The BP antigens and integrin alpha 6, which were absent in BCC and follicular matrix, were expressed in the follicular bulge area. Electron microscopically, hemidesmosomes were poorly organized in these three tissues, but the lamina densa was incomplete in BCC and follicular matrix, whereas the lamina densa in the follicular bulge area was continuous. These morphologic similarities between BCC and follicular matrix cells, and coexistence of melanocytes in the BCC tumor nest strongly suggest the differentiation of BCC toward the follicular matrix cells.

Basal Cell Carcinoma↗
PubMed1998

Effects of sex steroids and growth factors on invasive activity and 5'-deoxy-5-fluorouridine sensitivity in ovarian adenocarcinoma OMC-3 cells.

Effects of sex steroids (estradiol-17 beta, E2; progesterone, Prog) and growth factors (epidermal growth factor, EGF; transforming growth factor-alpha, TGF-alpha) on invasive activity and 5'-deoxy-5-fluorouridine (5'-dFUrd) sensitivity of ovarian adenocarcinoma OMC-3 cells were investigated. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were inhibited by 10 microM Prog, but stimulated by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. E2 did not have any effect on tumor cell migration or invasion. The zymography of tumor conditioned medium showed that the treatment of OMC-3 cells with EGF and TGF-alpha resulted in increases of type IV collagenase, stromelysin and urokinase-type plasminogen activator (uPA). EGF and TGF-alpha up-regulated thymidine phosphorylase (dThdPase) expression of tumor cells and consequently enhanced the antiproliferative action of 5'-dFUrd, which is converted to 5-fluorouracil by dThdPase. E2 and Prog did not have significant effects on the expression of proteolytic enzymes and dThdPase, or on the 5'-dFUrd sensitivity of tumor cells. The inhibitory effect of Prog on tumor cell invasion may depend on its inhibitory action on the motility of tumor cells. These results suggest that EGF and TGF-alpha simultaneously up-regulate the potential of ovarian adenocarcinoma cells to invade extracellular matrices and their dThdPase expression, both of which are associated with the specific action of 5'-dFUrd selectively to kill tumor cells with high invasive and metastatic potential.

Basement Membrane↗