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Biomedical subjects

T Takada

Publications and source records attributed to T Takada.

At least 109 records · Page 6Linked to original sources
PubMed1998

[Disappearance of embolic signals on transcranial Doppler sonography following antiplatelet therapy in a patient with transient ischemic attacks].

Transcranial Doppler sonography (TCD) has been increasingly used to detect embolic signals. A 49-year-old woman had repeated episodes of weakness and numbness of the right limbs. She was diagnosed as having transient ischemic attacks (TIAs). A cranial Gadolinium-enhanced MRI revealed multiple small lesions in the cortical-subcortical areas of the left middle cerebral artery territory. A TCD examination on admission detected 4 embolic signals on the left MCA trunk in a 30-minute examination period. TIAs completely ceased after the initiation of an antiplatelet therapy with aspirin. Embolic signals were not detected in later TCD studies. The embolic signals on the TCD strongly indicated that TIAs are caused by an embolic mechanism. TCD is potentially useful for assessing the efficacy of antiplatelet and anticoagulant therapies in patients with TIAs.

Aspirin↗
PubMed1998

[Improvement of detectability of microcalcifications by magnification digital mammography].

Our aim in this study was to evaluate the potential utility of magnification mammography with a CR system by investigating the basic imaging parameters and detectability of microcalcifications in comparison with those of conventional screen-film systems. The basic imaging parameters were evaluated by measuring scatter fraction, modulation transfer function (MTF), Wiener spectrum, and incident dose for the various magnification factors. The detection of simulated microcalcifications in radiographs of a mammographic phantom and breast specimens were evaluated subjectively and quantitatively for screen-film and CR techniques with various magnification factors. The scatter fraction of digital magnification mammography decreased with increasing magnification factor. MTF of magnification digital mammography improved with increasing magnification factor. The detectability of microcalcifications with the CR system was significantly improved by magnification technique. From the above results, it is expected that the use of magnification mammography with a CR system will improve the detectability of microcalcification.

Breast Diseases↗
PubMed1997

Midkine, a retinoic acid-inducible heparin-binding cytokine, is a novel regulator of intracellular calcium in human neutrophils.

Midkine (MK), which induces chemotaxis of human neutrophils, was found to trigger mobilization of intracellular calcium of these cells. The maximum response was observed 150 sec after exposure to MK, suggesting a complex mechanism in the process. The calcium mobilization was inhibited by herbimycin A, Bordetella pertussis toxin and wortmannin, suggesting that a tyrosine kinase, a G protein-linked receptor and phosphatidyl inositol 3 kinase are involved in the process.

Androstadienes↗
PubMed1997

Epidermal growth factor stimulates the tyrosine phosphorylation of SHPS-1 and association of SHPS-1 with SHP-2, a SH2 domain-containing protein tyrosine phosphatase.

SHPS-1 is a 120 kDa glycosylated receptor-like protein that contains immunoglobulin-like domains in its extracellular region and four potential tyrosine phosphorylation for SH2 domain binding sites in its cytoplasmic region. Epidermal growth factor (EGF) stimulated the rapid tyrosine phosphorylation of SHPS-1 and subsequent association of SHPS-1 with SHP-2, a protein tyrosine phosphatase containing SH2 domains, in Chinese hamster ovary cells overexpressing human EGF receptors. In the cells overexpressing SHPS-1, the tyrosine phosphorylation of SHPS-1 was more evident than that observed in parent cells. However, overexpression of SHPS-1 alone did not affect the activation of MAP kinase in response to EGF. These results suggest that SHPS-1 may be involved in the recruitment of SHP-2 from the cytosol to the plasma membrane in response to EGF.

Animals↗
PubMed1997

A survey of Salmonella enteritidis in spent hens and its relation to farming style in Hokkaido, Japan.

In order to estimate the distribution of Salmonella including Salmonella enteritidis (SE) and SE-antibodies in commercial layer hen flocks in Hokkaido, the northern prefecture of Japan, a survey of spent layer hens was performed, from August 1996 to January 1997. From the three spent hen processing plants, samples of intestines and sera were collected from 740 birds presented for slaughter from 37 flocks of 22 layer hen farms. Intestines from each birds were cultured for Salmonella including Salmonella enteritidis. Serum from each bird was examined for SE-antibody with the enzyme-linked immunosorbent assay (ELISA). Salmonella (any serotype) and Salmonella enteritidis were isolated from 50 (6.8%) and three (0.4%) of 740 birds, respectively, and SE-antibody positive values were recorded from seven birds (0.9%). SE-antibody positive birds did not always indicate isolation of Salmonella enteritidis, however SE-antibody positive hens were demonstrated only from Salmonella enteritidis positive flocks. Salmonellae were isolated from the birds of ten layer hen farms, all of these hens were raised in houses without windows and with automatic feeders. No isolations of salmonella were made from birds raised in houses with windows. From the windowless houses, Salmonellae were isolated from 46 (21.8%) of 260 birds in houses with four to six cages piled up vertically, and from six (2.5%) of 240 samples from the houses with four to five cages piled in a slanting manner.

Animals↗
PubMed1997

An 18-kDa domain of a glycosylphosphatidylinositol-linked NAD:arginine ADP-ribosyltransferase possesses NAD glycohydrolase activity.

Transfection of NMU (rat mammary adenocarcinoma) cells with NAD:arginine ADP-ribosyltransferase cDNAs from Yac-1 murine lymphoma cells or rabbit muscle increased NAD glycohydrolase and ADP-ribosyltransferase activities. The ADP-ribosyltransferase activity was released from transformed NMU cells by phosphatidylinositol-specific phospholipase C (PI-PLC) and hence glycosylphosphatidylinositol (GPI)-anchored, whereas the NAD glycohydrolase (NADase) activity remained cell-associated. By gel permeation chromatography, the size of the PI-PLC-released transferase was approximately 40 kDa and that of the detergent-solubilized NADase was approximately 100 kDa. Using polyclonal antibodies against rabbit muscle transferase on Western blots, approximately 18- and approximately 30-kDa band were visualized among proteins from the NADase fractions and 38-40-kDa bands with protein from the transferase fractions. Incubation of blots with [32P]NAD led to the incorporation of radioactivity into the immunoreactive transferase bands of 38 kDa and the immunoreactive NADase band of approximately 18 kDa. These data suggest that proteolysis of ADP-ribosyltransferase synthesized in transformed NMU cells might result in the formation of aggregates of an 18-kDa NAD glycohydrolase. A fusion protein with glutathione S-transferase linked to the amino terminus of Yac-1 transferase, from which the amino-terminal 121 amino acids had been deleted (GST-Yac-1-delta121), exhibited NADase, but not transferase, activity. The size of the recombinant fusion protein was similar to that of the proteolytic fragment seen in NMU cells transformed with transferase cDNA. These results are compatible with the conclusion that the NAD glycohydrolase activity was generated in NMU cells by proteolysis of ADP-ribosyltransferase, with release of a carboxyl-terminal fragment that possesses glycohydrolase but not transferase activity, i.e. the carboxyl-terminal portion of the transferase can exist as a catalytically active NADase.

ADP Ribose Transferases↗
PubMed1997

Bezoar (Capra aegagrus) is a matriarchal candidate for ancestor of domestic goat (Capra hircus): evidence from the mitochondrial DNA diversity.

The leading hypothesis on the ancestor of domestic goats (Capra hircus) is that it is the wild goat called the bezoar or pasang (Capra aegagrus). To verify this hypothesis, we sequenced and compared the cytochrome b gene of mitochondrial DNA from six domestic goats and bezoar. A further sequence for the markhor was taken from the database. In total we detected 51 nucleotide substitutions among the domestic goats, bezoar and markhor. However, only one specific nucleotide substitution was found between the domestic goats and the bezoar. On the other hand, 43 nucleotide substitutions were specific for the markhor. This result suggested a close relationship between the domestic goats and the bezoar. A neighbor-joining and parsimony phylogenetic tree constructed using the sequences showed that the domestic goats and the bezoar belong to the same cluster, while the markhor showed a distinct cluster separate from that of the domestic/bezoar cluster. This result was confirmed by trees based on the sequence of the mitochondrial displacement loop regions. These results suggest that the strongest candidate for a matriarchal ancestor of domestic goats is the bezoar.

Animals↗
PubMed1997

Selective production of transgenic mice using green fluorescent protein as a marker.

The low efficiency of transgenic animal production by microinjection has been a serious problem especially for the production of transgenic livestock. We developed a method to selectively produce transgenic mice using green fluorescent protein (GFP) as a marker. Using this method, we obtained eight fetuses and four live-born mice derived from 55 GFP-positive blastocysts. PCR analysis showed 11 out of 12 mice (fetuses and newborn mice) were transgenic. Southern blot analysis showed that 8 out of 12 were transgenic. GFP expression was also observed in bovine blastocysts, suggesting that this method should contribute to the efficient production of transgenic livestock.

Animals↗
PubMed1997

Midkine, a retinoic acid-inducible heparin-binding cytokine in inflammatory responses: chemotactic activity to neutrophils and association with inflammatory synovitis.

Midkine (MK) is a retinoic acid-inducible heparin-binding cytokine. In the inflammatory synovitis of rheumatoid arthritis and osteoarthritis, MK was detected in synovial fluid, synoviocytes, and endothelial cells of new blood vessels. Normal synovial fluid and noninflammatory synovial tissue did not contain detectable MK. Therefore, MK showed inflammation-associated expression in these cases. Furthermore, MK was found to promote chemotaxis of neutrophils in the range of 10 ng/ml. The mode of action of MK was found to be haptotactic; the substrate-bound form of MK was the active one. MK is also known to promote fibrinolysis. These activities of MK are in agreement with the modes of MK expression in various pathological statuses, and thus MK is proposed to be an important molecule regulating inflammatory responses.

Adult↗
PubMed1997

Giant hepatic angiomyolipoma associated with disseminated intravascular coagulation.

We report a case of giant hepatic angiomyolipoma in a 68-year-old woman who had an increase in the fibrinolytic activity concomitant with disseminated intravascular coagulation (DIC). The presence of the tumor was confirmed by ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen and the selective arteriography of the liver via the superior mesenteric artery. Following treatment with heparin and gabexate mesilate, abnormal hemostatic values were corrected. Furthermore, the surgical removal of the huge hepatic angiomyolipoma completely normalized the alternations of the clotting system. These findings suggest that giant hepatic angiomyolipoma was profoundly associated with DIC.

Aged↗
PubMed1997

[Preoperative synchronized chemoradiation therapy for advanced esophageal cancer].

Synchronized chemoradiation, where 5-FU and CDDP were synchronously administered in the same schedule with radiation therapy, was applied for advanced esophageal cancer in neoadjuvant fashion. Ten patients with advanced esophageal cancer were enrolled for this regimen consisting of 5-FU; 500 mg/day x 5/w x 4, CDDP; 10 mg/day x 5/w x 4 and radiation; 2 Gy x 5/w x 4. Tumor regression was achieved in all cases. In terms of toxicity, bone marrow suppression of more than grade 3 was observed in 60% of the cases, though it was safely controlled. Radical operation was performed on 8 cases. Histological responses in the resected specimen were as following: grade 3, 3 cases; grade 2b, 4 cases; grade 2a, 1 case; and 6 node-negative cases were found. As a postoperative complication, minor leakage occurred in 62.5%, while no major complications such as pneumonia were encountered. This neoadjuvant synchronized chemoradiation improved curability of the salvage operation and permitted reduction surgery for high-risk patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Pancreatic anastomosis after pancreatoduodenectomy].

Leakage from a pancreatic anastomosis after a pancreatoduodenectomy is one of the serious problems that can bring on life-threatening complications and lead to operative mortality. To minimize these complications, various reconstruction methods have been proposed. A series of 183 patients underwent pancreatoduodenectomy between August 1981 and December 1996 at 1st Department of Surgery, Teikyo University School of Medicine. Our pancreatic anastomoses were classified into four groups based on "Classification of Pancreatic Carcinoma (Japan Pancreas Society, FirstEnglish Edition, Kanehara, Tokyo 1996)",: (a) mucosa-to-mucosa pancreatico jejunostomy in 58 cases, (b) tube assisted (telescoped typed) pancreaticojejunostomyin 104, (c) pancreaticojejunostomy through dunking method in 2, and (d) panc reaticogastrostomy in 19. The leakage occured in 5 out of 104 of tube-assisted pancreaticojejunostomy, in 1 out of 19 of pancreaticogastrostomy. Due to the smooth healing process of anastomosis, mucosa-to-mucosa pancreaticojejunostomy have been applied, leading to results were no leakage occurred in 58 consecutive cases.

Anastomosis, Surgical↗
PubMed1997

[A case of rheumatoid arthritis (RA) with drug-induced acute pancreatitis due to mizoribine].

A rare case of mizoribine-induced acute pancreatitis is presented. A 39-year-old female with RA was admitted to our hospital because of upper abdominal pain, fever and the elevation of serum amylase concentration. Acute pancreatitis was diagnosed. Mizoribine (MZB) had been administered for 12 days for the treatment of RA before the onset of pancreatitis. Withdrawal of MZB soon resulted in the improvement of the disease. She was asymptomatic for the next few weeks. The pancreatitis recurred 36 hours after she took MZB again on her own judgement for arthralgia. This clinical course strongly suggested that her pancreatitis was due to MZB. Acute pancreatitis due to MZB has never, to our knowledge, been reported. MZB is commonly used for the treatment of RA. Therefore the clinician should take care for the complication of acute pancreatitis even though it is rare.

Acute Disease↗
PubMed1997

[Local control of hepatic malignant tumors by percutaneous microwave].

We investigated the effects of percutaneous microwave coagulation under general anesthesia in the local control of hepatic malignant tumors. Coagulation at 60 W was done for normal liver of living swine using a percutaneous electrode. Wide-range coagulation at the tip of an electrode, 3 mm in diameter, was conducted. Clinically, echo-guided percutaneous microwave tumor coagulation was done for a total of 11 lesions in 5 patients with hepatocellular carcinoma and 4 with metastatic tumors in the liver under general anesthesia. Coagulation at 60 W of the liver of living swine for 1.5 and 10 min, using a percutaneous electrode, produced a maximal coagulation of 10, 20 and 30 mm, respectively. The trial electrode permitted coagulation almost at the tip of the electrode only. Percutaneous microwave coagulation of 11 lesions of the clinical cases resulted in complete coagulation in 7 lesions and incomplete coagulation in 4. The lesions showing complete coagulation were all less than 23 mm.

Animals↗
PubMed1997

[Complication of reservoir hepatic artery infusion chemotherapy and additional treatments].

In 54 patients who underwent hepatic artery infusion chemotherapy for hepatic tumors at our hospital between January 1990 and December 1996, we investigated the complications of this therapy and the therapeutic techniques following its discontinuation. The arterial infusion was discontinued in 36 of the 54 patients; 13 due to death (mean survival period: 15.7 months), and 23 in whom occlusion of the reservoir, etc. made it impossible to use arterial infusion (mean period of use: 13.8 months), and the minimum duration of use was 41 days and maximum duration of use 992 days. The most common complication of the reservoir hepatic artery infusion was reservoir occlusion (14.8%). Another serious complication was reservoir deviation outside the blood vessel in two patients; deviation in to the gastric lumen in one case and intraperitoneal deviation in the other. Four hepatocellular carcinoma patients, in whom it became impossible to use the reservoir due to its occlusion, underwent re-hepatectomy. Three of them survived for more than two years following supplemental local therapy, including subarterial injection, TAE, PEIT, microwave tumor coagulation (MTC). Of four patients with colon cancer metastasizing to the liver, one could undergo re-hepatectomy, one received subarterial injection, and two have survived without relapse. Two of three patients with breast cancer underwent systemic chemotherapy and endocrine therapy successfully, while the third one underwent subarterial injection and TAE, and is still under observation. Hepatic artery infusion should sometimes be discontinued owing to complications caused by various factors. Even if it becomes impossible to use the reservoir, local therapeutic techniques, including re-hepatectomy, TAE, PEIT, MTC, etc., may be performed in some patients. These findings suggest that it is necessary to review the interdisciplinary treatment so as to be appropriate to the primary disease.

Aged↗
PubMed1997

[Preoperative chemoradiation therapy for advanced rectal cancer].

Preoperative concurrent chemoradiation therapy with 5-fluorouracil and cisplatin was applied for advanced rectal cancer. Eligible criteria were as follows: no previous treatment, 4 more than hemicircular occupation, T3 or more invasion to adjacent organs or lymph node metastasis on CT scan, tumor fixation by digital examination. Eleven patients were enrolled with this regimen consisting of 5-FU; 500mg/day x5/w x4, CDDP; 10mg/day X 5/w x4 and radiation; 2Gy x 5/w x 4. As a toxicity, grade 2 leukopenia in 2 cases, grade 2 GI symptoms in one case and radiation dermatitis was observed in 8 cases. As a local response, there were PR in 10 cases and NC in 1 case. Surgical resection was performed on 8 patients. Histological responses in the resected specimens were grade 2, 5 cases; grade 1b, 1 case; and grade la, 2 cases. Operative radicalities were grade A, 3 cases; grade B, 3 cases; and grade C, 2 cases. Preoperative chemoradiation is one of the effective options in multimodal treatment for advanced rectal cancer.

Adenocarcinoma↗
PubMed1997

Podocyte detachment and epithelial cell reaction in focal segmental glomerulosclerosis with cellular variants.

In primary focal segmental glomerulosclerosis with cellular variants the type of epithelial cells that segmentally or globally increased and their relation to sites where podocytes detached from the capillary wall, remain unclear. Two renal samples containing glomeruli with cellular variants were serially examined using transmission electron microscopy. A total of 10 lesions, including 2 collapsing glomerulopathy, 7 cellular lesions, and 1 sclerosis, were examined. Disappearance of the dense basal band of microfilaments from portions of podocytes was followed by detachment from the capillary basement membrane, resulting in segmental denudation of the capillary wall. The defects were not covered by other portions of epithelial cells, when the defects occurred in more central regions of the glomerulus. When detachment of podocytes occurred in the peripheral areas of the glomerulus, the defects were covered with new basement membrane and by other epithelial cells. These epithelial cells were characterized by the formation of intercellular junctional complexes of zonula adherens and desmosomes between each other and with the parietal epithelial cells (PECs), by showing occasional cilia, apoptotic nuclei, and mitosis. Thus, repair is achieved as the defect is covered by the participation of PECs; synechia and glomerular sclerosis result, depending upon the extent of the original podocyte injury.

Apoptosis↗