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Biomedical subjects

T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 235 records · Page 13Linked to original sources
PubMed1998

Modulation of osteoclast function by adenovirus vector-induced epidermal growth factor receptor.

We have explored the use of adenovirus vector-mediated gene transfer to introduce foreign genes into osteoclasts, terminally differentiated cells responsible for bone resorption. A replication-deficient adenovirus vector that contains a reporter gene encoding beta-galactosidase efficiently infected human osteoclast-like cells (OCLs) derived from human giant cell tumors and mouse OCLs formed in vitro. We then constructed an adenovirus vector carrying human epidermal growth factor receptor (EGFR) cDNA (Ax1CAhEGFR) and introduced the EGFR gene into mouse OCLs. Clear induction of EGF receptor was detected in Ax1CAhEGFR-infected OCLs (EGFR-OCLs) by immunocytochemistry and immunoblotting, and EGF stimulation induced rapid tyrosine phosphorylation of several proteins including EGF receptor itself. Large vacuoles appeared in EGFR-OCLs in response to EGF treatment, and pit-forming activity by EGFR-OCLs was dose-dependently suppressed by recombinant human EGF. In addition, survival of EGFR-OCLs was prolonged by EGF. No expression of EGF receptor or effects of EGF were observed in noninfected OCLs or control vector-infected OCLs. These results suggest that adenoviral vectors are useful for modulating osteoclast function by introducing foreign genes into osteoclasts and that they will be a good means of gene therapy of metabolic bone diseases.

Adenoviridae↗
PubMed1998

Enhanced activity of pyrimidine 5'-nucleotidase in rat red blood cells during erythropoiesis.

A nucleotidase that catalyzed selective hydrolysis of pyrimidine 5'-nucleotides was investigated in rat red blood cells (RBCs). The enzyme had similar catalytic properties to human pyrimidine 5'-nucleotidase I (P5N-I). The P5N-I deficiency was known to be closely correlated with the human inherited disease, non-spherocytic hemolytic anemia. Similar to the human P5N-I, the rat enzyme preferentially hydrolyzed 5'-(d)CMP and 5'-UMP but no reactivity was observed with any 3'-nucleotide. Molecular mass of the enzyme was estimated to be approximately 38 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis. Another subclass of pyrimidine 5'-nucleotidase, P5N-II, was also present in rat RBCs. This P5N-II-like enzyme, which resembled a 5'(3')-nucleotidase, preferentially hydrolyzed both 5'- and 3'- of (d)TMP or (d)UMP, but no cytosine nucleotide was hydrolyzed by the enzyme. Results from the reactivity with the antibody against rat 5'(3')-nucleotidase and estimated subunit molecular mass of the enzymes, about 26 kDa, suggested that the P5N-II-like enzyme had a similar structure to the 5'(3')-nucleotidase. The P5N-I-like activity in rat RBCs increased 5 to 6-fold at 4 days after phenylhydrazine injection, and reached a maximum at 6 to 7 days. No change in the activity of P5N-II-like nucleotidase was observed during the experimental period. The increase in rat P5N-I activity coincided with maturation of the erythrocytes.

5'-Nucleotidase↗
PubMed1998

Immunoelectron microscopic identification of lysozyme-expressing cells in human labial salivary glands.

Although human labial gland secretions contain serous components such as the bactericidal enzyme, lysozyme, the presence of serous cells in this gland has yet to be clearly visualized under the electron microscope. The present study identifies lysozyme-expressing cells of the labial glands using microwave-fixed, Epon-Araldite-embedded specimens, which showed excellent preservation of both ultrastructural detail and antigenicity for post-embedding immunogold labeling of lysozyme. Ultrastructurally, all of the secretory cells of the glands appeared to be a mucous-type and have a serial maturation relationship, consistent with a previous report by TANDLER et al. (1969a): their secretory granules were electron-lucent and exhibited reactivity for mucus staining by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method. We classified them into two immature types (I, II) and two mature types (I, II). Their distinctive features were the following: 1) relatively small (0.5-1 microm) secretory granules and well-developed basal rough endoplasmic reticulum for the immature types; 2) larger (1-2 microm) secretory granules and well-developed Golgi apparatus, which showed intense PA-TCH-SP reactivity in the 2-3 trans-cisterns, for the mature types; 3) few secretory granules in the immature type I; and 4) the darkest appearance for the mature type II. Immunogold labeling with anti-lysozyme showed specific labeling of the two immature-type cells, in which gold particles were found mainly over the secretory granules and Golgi apparatus, and moderately over the rough endoplasmic reticulum. In the secretory granules, the labeling was distributed throughout the contents and was present even if they showed strong PA-TCH-SP reactivity; in the Golgi area, it was seen over the stacked cisternae, trans-Golgi networks, and condensing vacuoles. No specific labeling was seen in the mature-type cells or in the duct cells. These immature- and mature-type cells were almost equivalent to the "serous demilune or acinus" and "mucous tubule" cells, respectively, at the light-microscopic level. These results indicate that the traditional "immature mucous-type cells" of the human labial glands produce lysozyme and should be classified as seromucous cells.

Coloring Agents↗
PubMed1998

Single-shot MR cholangiopancreatography of neonates, infants, and young children.

OBJECTIVE: This study was undertaken to assess the usefulness of MR cholangiopancreatography (MRCP) with a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence as a noninvasive imaging technique to evaluate biliary or pancreatic disease in young children. SUBJECTS AND METHODS: We prospectively examined 45 children (mean age, 3 years) with MRCP using HASTE on a 1.5-T MR imaging unit. MRCP images were obtained in 1.4 sec without breath-hold. A body phased array coil and fat saturation technique were used for data collection. On the basis of the surgical (n = 19) and ERCP (n = 7) findings, clinical data, and follow-up observation, 21 children were deemed to have no significant abnormality. The other 24 children were found to have pancreaticobiliary disease, including congenital biliary atresia in five neonates, choledochal cyst in six infants, and anomalous connections between the bile and pancreatic ducts in four infants and nine young children. In children without abnormality, the MRCP images were graded for the depiction of normal structures. The findings obtained by MRCP were correlated with the surgical or ERCP results. RESULTS: HASTE MRCP showed the first branch of the intrahepatic duct, the common hepatic duct, the gallbladder, and the common bile duct in most children. In the 21 children with no abnormalities, the main pancreatic duct was visible in two of six neonates, in four of five infants, and in all 10 young children. The diagnostic accuracy of MRCP was 100% in patients with choledochal cysts, 100% in those with congenital biliary atresia, and 69% in those with anomalous connections between the bile and pancreatic ducts. CONCLUSION: MRCP using HASTE with a phased array coil is a noninvasive technique for revealing the pancreaticobiliary tract in young children.

Biliary Atresia↗
PubMed1998

Jejunal varices as a cause of massive gastrointestinal bleeding--a case report.

This report describes a 49-year-old woman with recurrent massive gastrointenstinal bleeding from jejunal varices without portal hypertension. Preoperative diagnosis was obtained by abdominal computed tomography, superior mesenteric arterial angiography and percutaneous transhepatic portography. Percutaneous transhepatic portographic findings revealed no step-up of oxygen concentration and normal pressure in the portal vein, only dilation of superior mesenteric vein. Jejunal resection and anastomosis resulted in complete resolution of the bleeding, and the patient has experienced no recurrent bleeding over a 4 year follow-up period. A review of the literature shows that this syndrome is nearly always characterized by portal hypertension, generally due to liver cirrhosis. Accurate preoperative diagnosis is often difficult. We report a very rare case of jejunal varices without portal hypertension.

Female↗
PubMed1998

Pseudomyxoma peritonei. A report of three cases and a review of published reports.

Pseudomyxoma peritonei is a disease characterized by the progressive accumulation of mucinous ascites within the abdomen and pelvis. Metastatic disease outside the peritoneal cavity is unusual. Gastrointestinal function is lost from external compression of stomach, small bowel, and large bowel. We present three cases of pseudomyxoma peritonei which were treated by different therapeutic methods. Case 1 was a 61-year-old man who underwent treatment by appendectomy with administration of Cisplatin and Doxorubicin hydrochloride into the intraperitoneal cavity. Case 2 was a 64-year-old woman who underwent bilateral oophorectomy with administration of Cisplatin and ADM into the intraperitoneal cavity. About 4 years after the first operation, she died of peritonitis due to small and large bowel perforations underlying recurrent tumors. Case 3 was a 79-year-old woman who underwent surgery to evacuate about 4000 ml of mucinous ascites, and received intraperitoneal administration of 5-Fluorouracil (500 mg/day) for 5 days without severe complications.

Combined Modality Therapy↗
PubMed1998

Nonfunctioning islet cell carcinoma--a twenty-one years survival case after distal pancreatectomy.

A case of nonfunctioning islet cell carcinoma was reported. A 40-year-old woman was admitted with epigastralgia. Abdominal angiography and other diagnostic modalities suggested pancreatic malignancy. After distal pancreatectomy, histopathological study revealed her pancreatic tumor to be a nonfunctioning islet cell carcinoma. Fourteen years later, postoperative computed tomographic examination (CT) detected the recurrence of para-aortic lymph node metastases. Five years later, distal gastrectomy was performed to control bleeding from a gastric ulcer. Twenty-one years after the original operation, she died because of underlying metastatic carcinoma. In this case, slow growth and a low grade malignancy were characteristic. Operative removal of the tumor would be the treatment of choice even if metastatic lesions existed.

Adenoma, Islet Cell↗
PubMed1998

Effect of danazol on the pregnancy rate in patients with unsuccessful in vitro fertilization-embryo transfer.

OBJECTIVE: To determine the effect of danazol on in vitro fertilization-embryo transfer (IVF-ET) patients who failed to conceive in previous attempts despite having embryos with optimal morphology, whether endometriosis is present or not. STUDY DESIGN: In this prospective, randomized, controlled study, of 81 patients who experienced unexplained failures of IVF-ET despite having good-morphology embryos, 40 received danazol (400 mg/d orally for 12 weeks) following the unsuccessful IVF-ET cycle. The next IVF-ET was performed within three months of the first spontaneous ovulation after danazol administration. The remaining 41 patients constituted the control group, and in them the next IVF-ET was performed within six months after the previous failed cycle. RESULTS: Conception occurred in 16 of 40 (40%) danazol-treated patients at the subsequent cycle and showed a significant increase when compared with 8 of 41 (19.5%) control subjects (P < .05), though the number of embryos with optimal morphology decreased after danazol treatment. CONCLUSION: Danazol may be used for patients who have had repeated failures of IVF-ET despite having morphologically optimal embryos and may be useful for increasing receptivity of the endometrium in these patients.

Autoantibodies↗
PubMed1998

[Prospective matched control study concerning the treatment and quality of life of hemophiliacs with inhibitors].

Factor VIII (IX) inhibitors represent one of the most serious problems for the treatment of patients with hemophilia. The Blood Products Research Organization (Japan) has supported a study group for treatment of hemophiliacs with inhibitors. In 1995 the study group started a prospective matched control study of hemophiliacs with and without inhibitors and compared such factors as quality of life and economic cost. Each inhibitor patient was matched with a control patient in terms of age, type of hemophilia, and severity of hemophilia. A total of 136 patient-pairs were enrolled. Bleeding episodes were more frequent in the control group than in the inhibitor group. Days of hospitalization, days in wheelchairs, and the number of impaired joints were significantly higher for the inhibitor group. Number of blood-product infusions, days of bed rest at home, and days of brace use were the same for both groups. Blood-product expenditures were significantly higher for the inhibitor group than for the control group (yen 10,872,283/patient/year vs. yen 4,327,542/patient/year). Our study highlighted the higher cost of treatment and lower quality of life for hemophiliaes with Factor VII inhibitors.

Adult↗
PubMed1998

Immunogold labeling of peroxidase in salivary gland acinar cells using an improved tissue preparation procedure: rapid freezing and Lowicryl embedding.

The immunocytochemical localization of peroxidase in the acinar cells of the Mongolian gerbil parotid gland was studied using aldehyde-fixed tissue prepared by rapid freezing and low-temperature embedding in Lowicryl K4M resin. This freeze-embedding method was developed to provide improved preservation of cell ultrastructure and optimum accessibility of antigens, combined with relative technical ease. Immunogold labeling with antibody to peroxidase was found mainly in the dense cores of mature and immature secretory granules. In the trans Golgi area, the rough endoplasmic reticulum (rER), many clusters of smooth vesicles, and short tubular structures showed a variable labeling intensity. The results demonstrate the utility of this newly-developed preparative method and confirm the presence of peroxidase in elements of the Golgi apparatus.

Acrylic Resins↗
PubMed1998

Immunohistochemical detection of imidazolone and N(epsilon)-(carboxymethyl)lysine in aortas of hemodialysis patients.

The modification of long-lived proteins with advanced glycation endproducts (AGEs) has been hypothesised to contribute to the development of pathologies associated with uremia. Imidazolone and N(epsilon)-(carboxymethyl)lysine (CML) are common epitopes of AGE-modified proteins. Imidazolone is a reaction product of arginine with 3-deoxyglucosone (3-DG) which is markedly accumulated in uremic serum. CML is produced by glycoxidation, and represents a marker of oxidative stress. The specificity of anti-imidazolone antibody that we had developed was further examined using ELISA. The antibody reacted only with imidazolone derived from 3-DG and arginine, but did not react at all with the other imidazolone-like compounds such as reaction products of glyoxal, methylglyoxal, glucosone with arginine or a reaction product of 3-DG with creatine. Further, to determine if AGEs are involved in the development of atherosclerosis in hemodialysis (HD) patients, we studied the localisation of imidazolone and CML in the aortas obtained from HD patients by immunohistochemistry using the anti-imidazolone and anti-CML antibodies. Imidazolone and CML were localised in all atherosclerotic aortic walls of the HD patients. In conclusion, imidazolone and CML are localised in the characteristic lesions of atherosclerosis in HD patients. These results strongly suggest that imidazolone produced by 3-DG, and CML produced by glycoxidation may contribute to the development of atherosclerosis in uremic patients.

Aged↗
PubMed1998

[PSIF/CE-FAST (fast gradient echo) and TSE (turbo spin echo)].

Imaging techniques of PSIF/CE-FAST (fast gradient echo) and TSE (turbo spin echo) are described. PSIF/CE-FAST is a mirror imaged FISP (fast imaging with steady state precession) technique which is applied to MR cholangiopancreatography (MRCP) for the first time. However, it has been replaced by TSE technique because of poor resolution and motion artifacts. TSE is a fast imaging technique using multiecho method, which enables us to obtain high resolution MRCP with heavily T2-weighted images. MRCP using TSE shows high signal to noise ratio with minimal motion artifacts. Recently, breath-hold single shot fast imaging techniques within a few seconds or respiratory triggered TSE are applied to MRCP and shows higher resolution for pancreatobiliary ducts system.

Biliary Tract↗
PubMed1998

[The problems of nursing and medical expenses in end-stage home therapy].

Recently, many end-stage patients and their families desire home care in their last days, because Japanese tend to think "quality of life" is the most important thing in their life. Home therapy for end-stage patients has become popular with the support of the government. The cooperation between medical staff and patients has overcome many problems derived from this new therapy system. Problems related to the person who looks after the patient, however, remain to be solved. Ninety-four home therapy cases of end-stage cancer have been treated as a private clinic experience since 1994. Although the medical expenses for home therapy are greater than for hospital treatment under the Japanese medical insurance system, the nursing fees for the person who looks after the patient are not considered enough. A heavy burden, not only by the nursing but also by their own occupation, has been imposed upon the nursing person. Differences in the expenses between home therapy and hospital treatment, and also the situation of the nursing person in the home therapy are reported in this paper.

Adult↗
PubMed1997

Tertiary and quaternary structures of 0.19 alpha-amylase inhibitor from wheat kernel determined by X-ray analysis at 2.06 A resolution.

The crystal structure of 0.19 alpha-amylase inhibitor (0.19 AI) from wheat kernel was determined by the multiple-isomorphous replacement method coupled with density modification and noncrystallographic symmetry averaging and then refined by simulated annealing using diffraction data to 2.06 A resolution (R = 18.7%, free R = 22.3%). The asymmetric unit has four molecules of 0.19 AI, each comprised of 124 amino acid residues. Electron density for residues 1-4 and 69-77 is absent in all subunits, probably because of the intrinsic flexibility of these segments. Each subunit has four major alpha-helices and one one-turn helix which are arranged in the up-and-down manner, maintaining the favorable packing modes of the alpha-helices. 0.19 AI, however, has two short antiparallel beta-strands. All 10 cysteine residues in 0.19 AI form disulfide bonds (C6-C52, C20-C41, C28-C83, C42-C99, and C54-C115), consistent with the assignments made biochemically for 0.28 AI from wheat kernel and by NMR analysis of the bifunctional alpha-amylase/trypsin inhibitor from ragi seeds (RBI). The disulfide bond patterns in these AIs are similar to those in the hydrophobic protein from soybean (HPS), which lack only the bond corresponding to C28-C83 in 0.19 AI. Extensive interactions occurred between particular pairs of 0.19 AI subunits, mainly involving hydrophobic residues. Comparisons of the structures of 0.19 AI, RBI, and HPS showed that the arrangements of the major alpha-helices are similar but the conformations of the remaining residues differ markedly. The present X-ray analysis for 0.19 AI and the NMR analysis for RBI suggest that all the AIs in this family have a common fold. The alpha-amylase binding site is discussed on the basis of the tertiary and quaternary structures of 0.19 AI together with biochemical and spectroscopic data for AIs.

Amino Acid Sequence↗