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Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 181 records · Page 10Linked to original sources
PubMed2000

Identification of a receptor for reg (regenerating gene) protein, a pancreatic beta-cell regeneration factor.

Reg (regenerating gene) was isolated as a gene specifically expressed in regenerating islets (Terazono, K., Yamamoto, H., Takasawa, S., Shiga, K., Yonemura, Y., Tochino, Y., and Okamoto, H. (1988) J. Biol. Chem. 263, 2111-2114). Rat and human Reg gene products, Reg/REG proteins, have been demonstrated to stimulate islet beta-cell growth in vitro and in vivo and to ameliorate experimental diabetes. In the present study, we isolated a cDNA for the Reg protein receptor from a rat islet cDNA library. The cDNA encoded a cell surface 919-amino acid protein, and the cells into which the cDNA had been introduced bound Reg protein with high affinity. When the cDNA was introduced into RINm5F cells, a pancreatic beta-cell line that shows Reg-dependent growth, the transformants exhibited significant increases in the incorporation of 5'-bromo-2'-deoxyuridine as well as in the cell numbers in response to Reg protein. A homology search revealed that the cDNA is a homologue to a human multiple exostoses-like gene, the function of which has hitherto been unknown. These results strongly suggest that the receptor is encoded by the exostoses-like gene and mediates a growth signal of Reg protein for beta-cell regeneration.

Amino Acid Sequence↗
PubMed2000

Identification of a novel Reg family gene, Reg IIIdelta, and mapping of all three types of Reg family gene in a 75 kilobase mouse genomic region.

Regenerating gene (Reg), first isolated from a regenerating islet cDNA library, encodes a secretory protein with a growth stimulating effect on pancreatic beta cells that ameliorates the diabetes of 90% depancreatized rats and non-obese diabetic mice. Reg and Reg-related genes have been revealed to constitute a multigene family, the Reg family, which consists of three subtypes (types I, II, III) based on the primary structures of the encoded proteins of the genes. We have isolated three types of mouse Reg family gene (Reg I, Reg II, Reg IIIalpha, Reg IIIbeta and Reg IIIgamma) [Unno et al. (1993) J. Biol. Chem. 268, 15974-15982; Narushima et al. (1997) Gene 185, 159-168]. In the present study, by Southern blot analysis of a mouse bacterial artificial chromosome clone containing the five Reg family genes in combination with PCR cloning of every interspace fragment between adjacent genes, the Reg family genes were mapped to a contiguous 75kb region of the mouse genome according to the following order: 5'-Reg IIIbeta-Reg IIIalpha-Reg II-Reg I-Reg IIIgamma-3'. In the process of ordering the genes, we sequenced the 6.8kb interspace fragment between Reg IIIbeta and Reg IIIalpha and encountered a novel type III Reg gene, Reg IIIdelta. This gene is divided into six exons spanning about 3kb, and encodes a 175 amino acid protein with 40-52% identity with the other five mouse Reg (regenerating gene product) proteins. Reg IIIdelta was expressed predominantly in exocrine pancreas, but not in normal islets, hyperplastic islets, intestine or colon, whereas both Reg I and Reg II were expressed in hyperplastic islets and Reg IIIalpha, Reg IIIbeta and Reg IIIgamma were expressed strongly in the intestinal tract. Possible roles of Reg IIIdelta and the widespread occurrence of the Reg IIIdelta gene in mammalian genomes are discussed.

Animals↗
PubMed2000

A preliminary outcome analysis of the Patterns of Care Study in Japan for esophageal cancer patients with special reference to age: non surgery group.

BACKGROUND: The Patterns of Care Study (PCS) was imported to Japan from the United States in July 1996. A preliminary outcome analysis of the PCS for esophageal cancer patients in Japan was made with special reference to age, because the elderly population is rapidly increasing in Japan. PATIENTS AND METHODS: From July 1996 to February 1998, external PCS audits were performed for 37 institutions nationwide and detailed information of 561 esophageal cancer patients treated during the period 1992-1994 was collected by using the fifth PCS data format developed in the United States. This format was provided courtesy of the American College of Radiology. For this study, patients who had not undergone surgery (n = 336) were selected. The patients were classified into three age groups: < 65 years old (n = 119), between 65 and 74 years (n = 93), and 75 years or older (n =123). Cox's proportional hazards model was used for the statistical analysis, with survival, acute/subacute complication and late complication of grade 3 or more based on RTOG criteria, as the endpoints. RESULTS: Significant prognostic factors for the entire non-surgery group were Karnofsky Performance Status (KPS) (p = 0.0007), stage (p = 0.0001), and external irradiation dose (p = 0.0001). For the younger group, KPS (p = 0.0004), stage (p = 0.0197), and utilization of brachytherapy (p = 0.0010) were significant, while for the intermediate age group it was KPS (p = 0. 0027), history of pulmonary disease (p = 0.0339), stage (p = 0.0001), and external dose (p = 0.0001), and for the elderly group, stage (p = 0.0001) and external irradiation dose (p = 0.0224) were significant. Significant risk factors for complications for the entire group were stage (p = 0.0411), external dose (p = 0.0163), and stratification of institution (academic vs. nonacademic) (p = 0. 0114). Significant risk factors for the younger group were history of pulmonary disease (p = 0.0495) and external dose (p = 0.0037), and the other age groups showed no significant risk factors. CONCLUSION: Age was not a significant prognostic or risk factor for esophageal cancer patients in the non-surgery group treated with radiation therapy. Therefore, radiation therapy represented an important treatment modality for the elderly as well as for the younger esophageal cancer patients. External dose was a treatment-related prognostic factor for the elderly as well as for the intermediate age group.

Adenocarcinoma↗
PubMed2000

Indispensable role of the transcription factor PEBP2/CBF in angiogenic activity of a murine endothelial cell MSS31.

Mice lacking the AML1/PEBP2alphaB/CBFa2 gene or PEBP2beta/CBFb gene exhibit a defect in definitive hematopoiesis and die in utero because of hemorrhage in the central nervous system. Hematopoiesis in the embryo is considered to be tightly associated with vascular development. Here we examined whether PEBP2/CBF plays any role in angiogenesis besides that in definitive hematopoiesis. We found that AML1/PEBP2alphaB/CBFa2, PEBP2alphaA/CBFa1, and PEBP2beta/CBFb were expressed in a murine endothelial cell line MSS31. The expression of these molecules as well as the DNA binding activity of PEBP2/CBF were augmented by angiogenic growth factors such as bFGF and VEGF. Moreover, the expression of PEBP2 alpha/CBFa protein in endothelial cells was confirmed at the site of angiogenesis in vivo. To further clarify the role of PEBP2/CBF in angiogenesis, we established permanent transfectants of PEBP2 beta-MYH11 gene, one that interacts with the runt domain of the alpha subunit and deregulates PEBP2/CBF in a dominant interfering manner. Proliferation, migration, and tube formation of the PEBP2 beta-MYH11 transfectants were significantly reduced in comparison with those activities of the mock transfectants. These results suggest that transcription factor PEBP2/CBF plays an important role in angiogenesis.

Animals↗
PubMed2000

Angiogenesis inhibition by transdominant mutant Ets-1.

The expression of transcription factor Ets-1 is induced in endothelial cells (ECs) by angiogenic factor; and in turn Ets-1 converts ECs to angiogenic invasive phenotype. In order to control angiogenesis, we constructed a transdominant mutant Ets-1 (TMEts-1) which acts as a dominant negative molecule. This molecule inhibited the DNA binding and the transactivation activity of the wild-type Ets-1. Stable transfection of murine endothelial cell line MSS31 cells with the TMets-1 gene impaired angiogenic activities including proliferation, migration, invasion, and tube formation in type-1 collagen gel. Finally, we incorporated the TMets-1 gene into a non-proliferative adenovirus vector, designated as AdTMets-1. AdTMets-1 significantly inhibited angiogenesis in the Matrigel plugs injected into the subcutaneous tissue of C57BL mice. These results indicate that TMets-1 would be a tool for angiogenic inhibition.

3T3 Cells↗
PubMed2000

First missense mutations (R388W and R425H) of AMPD1 accompanied with myopathy found in a Japanese patient.

Skeletal muscle AMP deaminase (AMPD: E.C. 3.5.4.6) deficiency is one of the most common inherited defects in the Caucasians, but not in Asians. Although a diagnosis of AMPD1 deficiency is indeed based on the reduced enzymatic activity, its clinical significance is still rather controversial since most subjects are asymptomatic. Alternative splicing of exon 2 in individuals who have inherited this defect is thought to provide a mechanism for phenotypic rescue that may explain the variability of clinical symptoms as we reported earlier. In this report we present the first case with a detectable defect of the AMPD1 gene in a Japanese patient with myopathy. Two missense mutations (R388W and R425H) in exon 9 and exon 10 of the AMPD1 gene were found. Prokaryotic expression showed a comparable amount of the AMPD1 peptides and undetectable AMPD activity in the constructs with these mutations. From this study, we have concluded that this patient is a compound heterozygote for AMPD1 mutant allele. This study also demonstrates the first reported instance of detectable dysfunction of the AMPD1 gene product, suggesting that AMPD1 indeed has a key role in muscle metabolism and function.

AMP Deaminase↗
PubMed2000

Circadian rhythm of serotonin N -acetyltransferase activity in rat lens.

Activity of serotonin N -acetyltransferase (NAT), a key regulatory enzyme in melatonin biosynthesis, was detected in the rat lens. NAT activity in the lens showed significant diurnal variation in vivo and in vitro, peaking during the period of darkness, when the lenses were maintained under 14 hr light/10 hr dark cycle. Cultured lenses exhibited a circadian rhythm of NAT activity when maintained under constant darkness. However, the rhythm in vitro was not entrained when the light/dark cycle was delayed 8 hr from the cycle in intact animals. These data strongly suggest that the rat lens contains a circadian clock that controls NAT activity, although the circadian clock appears to lack a photic entrainment mechanism.

Animals↗
PubMed2000

Signal transduction and transcriptional regulation of angiogenesis.

When quiescent endothelial cells (ECs) are exposed to angiogenic factor such as VEGF; ECs express proteases to degrade extracellular matrices, migrate, proliferate and form new vessels. However, the molecular mechanism of these events is not fully characterized yet. We are studying the signal transduction and transcriptional regulation of angiogenesis. We investigated the properties of two VEGF receptors, Flt-1 and KDR, by using two newly developed blocking monoclonal antibodies (mAbs), i.e., anti-human Flt-1 mAb and anti-human KDR mAb. VEGF elicited induction of transcription factor Ets-1 in human umbilical vein endothelial cells (HUVECs). This induction was mediated by the KDR/Flt-1 heterodimer and the KDR homodimer. The role of transcription factor Ets-1 in angiogenesis was further clarified. We established both high and low Ets-1 expressing EC lines, and compared angiogenic properties of these cell lines with a parental murine EC line, MSS31. The growth rate was almost identical among three cell lines. It appeared that gene expressions of matrix metalloproteinases (MMP-1, MMP-3, and MMP-9) as well as integrin beta 3 were correlated with the level of Ets-1 expression. As a result, the invasiveness was enhanced in high Ets-1 expressing cells and reduced in low Ets-1 expressing cells compared with parental cells, and high Ets-1 expressing cells made more tube-like structures in type 1 collagen gel. These results indicate that Ets-1 is a principle transcription factor converting ECs to the angiogeneic phenotype.

Animals↗
PubMed2000

Analyses of proliferative potential in schwannomas.

We report studies of schwannomas with a high percentage of MIB-1 positive cells. Thirty-eight specimens from 36 cases of schwannoma in the intracranial and spinal regions comprise the substance of this study. The MIB-1 positive cells were measured using immunohistochemical staining. In nine cases with a positivity index (PI) of 5% or more, immunohistochemical staining using DNA topoisomerase IIalpha (topo-II) and CD68 was performed. In some cases, we also searched for apoptosis with the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. Three of nine cases with 5% or more positive MIB-1 cells had a very high cellularity with mitotic figures and were considered cellular Schwannomas. Their MIB-1 PI values were 8.21%, 10.00%, and 21.37%. However, the remaining six cases showed little evidence of malignancy. Their PIs were comparatively low, ranging from 5.19% to 8.41%, and the positive findings were localized in many cases. In these cases, we examined the sites where MIB-1 was measured and found that they corresponded to the borderline site between Antoni type A and B patterns and tended to be associated with an infiltration of CD68-positive macrophage. Furthermore, apoptotic cells appeared in the sites. With topo-II staining, the PIs in the same sites of these six cases were low, ranging from 0.78% to 1.93%. This implies that the high MIB-1 PI that was seen in these six cases was caused by reaction of MIB-1 to tumor cells that brought about an abnormality in the cell cycle by degeneration, such as apoptosis. In the site of formation of Antoni type B, MIB-1 may be a false positive in tumors with degenerative findings such as schwannomas. Topo-II was useful in these cases.

Adult↗
PubMed2000

Irreducible acute anterior dislocation of the shoulder caused by interposed fragment of the anterior glenoid rim.

Failure of manipulative reduction of acute anterior dislocation of the shoulder is extremely rare. A 55-year-old man dislocated his right shoulder when he fell heavily. Initial radiographs and computed tomographs demonstrated an anterior dislocation with fracture of the glenoid rim. Several attempts at closed reduction were unsuccessful. At the time of open reduction, the cause of failure was found to be interposition of a fragment of the anterior inferior glenoid rim in the joint. To prevent redislocation, the fragment was held in place by two Herbert mini bone screws after anatomic reduction, and the ruptured subscapularis was reattached to the lesser tuberosity. Two and a half months after surgery, the shoulder was stable with full range of motion. To the best of our knowledge, this is the first reported case of interposition of a fracture-fragment of the anterior inferior glenoid rim causing failure of reduction.

Bone Screws↗
PubMed2000

Sonic detection system for cervical and intracranial vascular disease.

A sonic analysis system was developed for the detection of cervical and intracranial vascular disease (CVD). In this study, sound signals detected through the patient's forehead were analyzed using a short-time Fourier transformation method, and data were evaluated according to the intensity of spectra. A total of 49 patients with CVD and 34 control subjects were studied and classified into four grades according to the intensity of the spectra. The true positive rate was 83.7% in patients with CVD, and the true negative rate was 94.1% in the control group. The sensitivity and specificity of this analysis system were 83.7% and 5.9%, respectively. The true positive rates for cerebral stenosis/occlusion, cerebral aneurysm, and arteriovenous malformation/fistula were 85.7%, 73.7%, and 100%, respectively. The future goal is clinical application as a mass-screening test for brain disease. This system shows potential for this purpose, and further development will continue.

Acoustics↗
PubMed2000

Identification of four highly conserved regions in DNA-PKcs.

The gene for the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is responsible for severe combined immune deficiency (SCID) and its products associate with Ku70/Ku86 autoantigens, c-Abl, and other factors to exert its roles. Investigations to date suggest that DNA-PKcs comprises several regions which specifically interact with these known and other as yet unidentified factors. Nevertheless, the relationship between the structure and function of the DNA-PKcs molecule is poorly understood. Here we report cloning of the entire DNA-PKcs cDNA from chicken and Xenopus laevis. Comparative study of the DNA-PKcs polypeptides from four different vertebrates revealed at least three novel conserved regions in addition to the carboxyl-terminal region containing the phosphatidylinositol-3 kinase domain. We also demonstrated that the four vertebrates share the common genomic organization between a licensing factor, MCM4, and DNA-PKcs, both of which locate in a head-to-head manner within a few kilobase intervals. These data provide useful clues for the further genetic study of this huge multifunctional enzyme.

Amino Acid Sequence↗
PubMed2000

Polymorphisms in IgG Fc receptor IIB regulatory regions associated with autoimmune susceptibility.

Autoimmune diseases involve multiple genes. While functions of these genes are largely unknown, some may be related to an intrinsic hyperresponsiveness of B cells. B-cell responses are controlled by signaling thresholds through the B-cell antigen receptor (BCR) complex. The B1 isoform of type II IgG Fc receptors (FcgammaRIIB1) is exclusively expressed on B cells and serves as a negative regulator for inhibiting BCR-elicited activation. Thus, its allelic variants associated with functional deficits could be examined for possible associations with susceptibility to autoimmune diseases. We found that there are three types of polymorphisms in the reported FcgammaRIIB transcription regulatory regions in mouse strains. Compared to normal healthy mouse strains (group III), autoimmune disease-prone strains (group I) share three deletion sites: two in the promoter region and one in the third intron. Strains (group II) that per se are not autoimmune-prone, but have potentials to accelerate autoimmune diseases share two deletion sites in the third intron: one identical to that in group I and the other unique to group II. These polymorphisms correlated well with extents of down-regulation of FcgammaRIIB1 expression in germinal-center B cells upon stimulation with antigens and up-regulation of IgG antibody responses. Our data imply that these FcgammaRIIB polymorphisms are selected evolutionarily for natural defense against pathogens, and that such polymorphisms may, in turn, form the basis of one aspect of autoimmune susceptibility.

Animals↗
PubMed2000

Late-type recurrence at the port site of unexpected gallbladder carcinoma after a laparoscopic cholecystectomy: report of a case.

A 73-year-old woman had a laparoscopic cholecystectomy for unexpected gallbladder cancer and 9 days later underwent both a liver bed resection and lymph node dissection. Four years later, she underwent a further resection of a port site recurrence of gallbladder cancer and no other site of recurrence was observed. The seeding of cancer cells during the removal of the resected gallbladder might have caused this tumor. This case may show that the port site recurrence did not necessarily indicate an incurable stage of the disease. In addition, an excision of the recurrent tumor also appeared to eliminate the disease in the patient.

Abdominal Muscles↗
PubMed2000

Management of nodular goiters and their operative indications.

It remains controversial whether or not nodular goiters should be treated surgically or conservatively. This report reviews our 9-year experience of treating nodular goiters in 334 patients, 44 of whom underwent surgery, and compares the methods of treatment employed from 1990 to 1999 with those employed from 1971 to 1989 when 171 operations were carried out. In accordance with diagnoses made using fine-needle aspiration biopsy (FNAB) and ultrasonography, patients were treated as follows. Those with cysts were given percutaneous ethanol injection therapy (PEIT), and those with solid tumors underwent surgery if cancer of >class 3 was suspected or if the tumors were >3 cm. Consequently, 44 patients with solid tumors underwent surgery and 72 with cysts were treated by PEIT. The number of operations performed annually decreased to half of the pre-1990 figure. During the follow-up of those patients who did not undergo surgery, four with solid tumors and two with cysts later required surgery due to suspected carcinoma of >class 3 in 3 patients or as a result of personal choice in 3 patients. The growth of solid tumors was not able to be measured in most cases. These results indicate that the number of operations performed for nodular goiters can be reduced by PEIT. An accurate cytological diagnosis supports this therapeutic strategy.

Biopsy, Needle↗
PubMed2000

Distribution of type VII collagen in the epithelial basement membranes of mouse palate, tongue and lip mucosa.

Dithiothreitol effectively separated the laminae densae and the laminae fibroreticulares of the basement membranes of oral mucosal epithelia as it does the epidermis and dermis. Dithiothreitol-separated epithelial basement membranes of palate, tongue, and lip were immunoreacted with colloidal gold-conjugated anti-type VII collagen antibody. By transmission electron microscopy, gold particles were observed only on the anchoring fibrils. For three-dimensional observation of the distribution of type VII collagen by scanning electron microscopy, secondary and backscattered electron images were compared. The secondary image showed the fine structure of the laminae densae and anchoring fibrils, and the backscattered images showed the gold particles conjugated with the antibody. By using an osmium conductive metal coating under optimal conditions, secondary and backscattered electron images of sufficient quality could be obtained. With the osmium coating, the backscattered electron image could show not only the gold particles but also the general morphological outline, making possible a comparison of the two images, which revealed the three-dimensional distribution of type VII collagen. Type VII collagen was also seen only on the anchoring fibrils, as in the epidermal basement membrane.

Animals↗