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T Kusano

Publications and source records attributed to T Kusano.

At least 55 records · Page 3Linked to original sources
PubMed1998

Successful gene transfer to the porcine liver in vivo with an adenoviral vector.

In vivo gene transfer to the porcine liver was tested with adenoviral vector to achieve molecular biological graft modulation. In adult female pigs immunosuppressed with cyclophosphamide, cyclosporine, and prednisolone, the liver was surgically isolated and flushed out with cold lactate Ringer solution (4 degrees C), by means of a pump-controlled bypass of the portal vein and the inferior vena cava in Groups A and D. In Group A (n = 4), 2 x 1011 pfu of the adenoviral vectors (pAdexCALacZ) were injected through the left hepatic artery during cold ischemia. In Group (n = 4), 2 x 1011 pfu of adenovirus vectors were injected through the auricular vein in a one-shot manner without a laparotomy. In Group C (n = 4), 2 x 1011 pfu/ml of adenoviral vectors were injected through the hepatic artery in a one-shot manner, without a surgical isolation of the liver. Group D (n = 4) animals received the same protocol as Group A except for the fact that they did not receive the immunosuppressive regimen. In a polymerase chain reaction, a transfected LacZ sequence was detected until POD 28 in Group A, but not in the other groups. In 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal) staining, only the Group A animals revealed apparent staining predominantly in the portal area at POD 2, which then continued to be recognized until POD 28. The in situ perfusion of the liver combined with immunosuppression is thought to provide an ideal environment for the liver-directed adenovirus-mediated gene transfer to the porcine liver, by enabling a long contact with a high titer of the adenoviral vector.

Adenoviridae↗
PubMed1998

Purification and characterization of 9-hexadecenoic acid cis-trans isomerase from pseudomonas sp. strain E-3

A 9-hexadecenoic acid cis-trans isomerase (9-isomerase) that catalyzed the cis-to-trans isomerization of the double bond of free 9-cis-hexadecenoic acid [16:1(9c)] was purified to homogeneity from an extract of Pseudomonas sp. strain E-3 and characterized. Electrophoresis of the purified enzyme on both incompletely denaturing and denaturing polyacrylamide gels yielded a single band of a protein with a molecular mass of 80 kDa, suggesting that the isomerase is a monomeric protein of 80 kDa. The 9-isomerase, assayed with 16:1(9c) as a substrate, had a specific activity of 22.8 &mgr;mol h-1 (mg protein)-1 and a Km of 117.6 mM. The optimal pH and temperature for catalysis were approximately pH 7-8 and 30 degrees C, respectively. The 9-isomerase catalyzed the cis-to-trans conversion of a double bond at positions 9, 10, or 11, but not that of a double bond at position 6 or 7 of cis-mono-unsaturated fatty acids with carbon chain lengths of 14, 15, 16, and 17. Octadecenoic acids with a double bond at position 9 or 11 were not susceptible to isomerization. These results suggest that 9-isomerase has a strict specificity for both the position of the double bond and the chain length of the fatty acid. The enzyme catalyzed the cis-to-trans isomerization of fatty acids in a free form, and in the presence of a membrane fraction it was also able to isomerize 16:1(9c) esterified to phosphatidylethanolamine. The 9-isomerase was strongly inhibited by catecholic antioxidants such as alpha-tocopherol and nordihydroguaiaretic acid, but was not inhibited by 1, 10-phenanthroline or EDTA or under anoxic conditions. Based on these results, the possible mechanism of catalysis by this enzyme is discussed.

Journal Article↗
PubMed1998

Radiation enterocolitis: overview of the past 15 years.

From April 1980 to April 1995 a total of 54 patients (53 women, 1 man) were hospitalized in our department for the surgical treatment of radiation enterocolitis. Two surgical protocols were applied for these patients: intestinal decompression procedures alone (intestinal bypass, colostomy, or both; n = 18) or an intestinal resection in addition to decompression (n = 36). The clinical factors contributing to survival after irradiation were retrospectively reviewed by a multiple variate proportional hazards model. As a result, patients treated with decompression procedures alone had an 11 times higher risk for death than those treated with the addition of intestinal resection. In the former group, 5 of 18 patients died of bleeding from the remaining intestine after operation. We concluded that surgical resection of the diseased intestine is a useful procedure for treating radiation enterocolitis to reduce intestinal bleeding from the irradiated intestine.

Adult↗
PubMed1998

Perforation due to metastatic tumors of the ileocecal region.

We reviewed our department's medical records between April 1986 and April 1994 to identify patients who showed acute abdominal symptoms requiring surgical treatment due to metastatic tumors of the small intestine. In group A, seven patients (30%) were treated for acute peritonitis, and all were found to have an intestinal perforation due to hematogenous metastases (group A). In group B, 16 patients (70%) were treated for an intestinal obstruction, and all were found to have disseminated tumors of the small intestine (group B). In group A all tumors were isolated and located exclusively in the ileocecal region, whereas all tumors in group B showed peritoneal dissemination, with no predominant anatomic localization. In general, the intestinal tumors in group A originated from cancers of the upper aerodigestive tract, whereas those in group B originated from advanced cancers in the abdominal cavity. The tumors were significantly smaller and the period between the onset of symptoms from the original malignancy and the onset of abdominal symptoms (perforation or obstruction) was significantly shorter in group A. In conclusion, intestinal metastases located in the ileocecal region have unique clinicopathologic features and so should be recognized as a distinct disease entity. Therefore when patients with a known upper aerodigestive malignancy exhibit acute abdominal symptoms, intestinal metastasis to the ileocecal region, necrotic changes, and perforation should be considered in the differential diagnosis.

Abdominal Neoplasms↗
PubMed1998

Combined hepatocellular and cholangiocellular carcinoma in a non-cirrhotic liver.

Combined hepatocellular (HCC) and cholangiocellular carcinoma (CCC) (mixed carcinoma) is a rare subtype of primary hepatic carcinoma. We report a case of mixed carcinoma that developed in a non-cirrhotic liver, in a patient who was serologically negative for both hepatitis B and C viruses. A 65-year-old Japanese woman with a 25-year history of chronic rheumatoid arthritis had been treated with steroids and anti-inflammatory drugs, and was diagnosed by ultrasonography with an asymptomatic solitary tumor in the right lobe of the liver. On computed tomography scan and hepatic arteriography, the tumor was well enhanced by contrast medium in the early phase. Based on the findings of elevated serum alpha-feto protein (AFP, 245 ng/ml) and normal carcino-embryonic antigen (CEA, 2.6 ng/ml) levels, a preoperative diagnosis of hepatocellular carcinoma was made. Right lobectomy of the liver was performed on January 7, 1997. Histological examination showed that the resected tumor consisted of combined CCC cells and HCC cells in an intermingled form, with CCC being far more dominant than HCC. The tumor was therefore determined to be a combined carcinoma, subclassified as intermingled type. This case appears to indicate that mixed type carcinoma developed in a non-cirrhotic liver, with CCC being dominant; such a finding is extremely unusual, based on previously published reports.

Aged↗
PubMed1998

Preparation of a conjugate of mitomycin C and anti-neural cell adhesion molecule monoclonal antibody for specific chemotherapy against biliary tract carcinoma.

To develop a specific chemotherapy modality for the perineural invasion of neural cell adhesion molecule (NCAM) positive biliary tract cancer, an anticancer drug, mitomycin C (MMC), was covalently bound to anti-NCAM monoclonal antibody (anti-NCAM MoAb) to form a conjugate using the cyanogen bromide method. The substitution ratio of the conjugate determined spectrophotometrically was 3.5 (MMC mol/immunoglobulin G mol). The cytotoxic activity of the conjugate, which was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test in the growth inhibition of the neuroblastoma cell line with NCAM expression, was maintained at 65.8% to 94.5% compared with the same concentration of MMC solution. The binding activity of the conjugate to the NCAM-positive bile duct cancer was examined by immunohistochemical staining and proved to be the same level as that of free anti-NCAM MoAb. The conjugate prepared in this study therefore appeared to be a potentially useful tool for immunotargeting specific chemotherapy against biliary tract cancer with NCAM expression.

Antibiotics, Antineoplastic↗
PubMed1998

Two maize genes encoding omega-3 fatty acid desaturase and their differential expression to temperature.

We have isolated two maize cDNAs and the corresponding genes encoding fatty acid desaturase with Arabidopsis thaliana FAD7 gene as a probe. They shared almost 90% identity at DNA sequence level. Northern analysis revealed that both genes are expressed in leaves, but not in roots at normal temperature- and low temperature-growth condition. The overall level of these transcripts are elevated upon exposure to low temperature. The tissue-specific expression and DNA sequence data indicate that both genes encode plastidic omega-3 fatty acid desaturases. One of them is expressed exclusively at normal temperature but not at 5 degrees C, whereas the other is expressed inversely. We, therefore, termed them ZmFAD7 and ZmFAD8, respectively. Among other stresses, high-salt treatment induced the accumulation of the ZmFAD7 and ZmFAD8 transcripts in roots but drought had no effect on their expression. Cycloheximide induced the accumulation of the ZmFAD7 transcript in roots. The genomic clones of ZmFAD7 and ZmFAD8 consist of 8 exons and 7 introns as same as in the cases of A. thaliana FAD7 and FAD8 genes and the sizes of the 6 internal exons were identical among them. A phylogenetic analysis of ZmFAD7, ZmFAD8 amino acid sequences and those originated from other plant species is also presented.

Amino Acid Sequence↗
PubMed1998

Difference in hepatic tissue oxygenation between total vascular exclusion and inflow occlusion of the liver and the possible role of hepatic venous blood under liver ischemia.

The difference between total vascular exclusion (TVE) and inflow occlusion (IO) of the liver was assessed by the extent of DNA injury in rats and by hepatic tissue oxygen saturation (SahtO2) in pigs. Moreover, the role of hepatic venous blood under liver ischemia was discussed. Seventy percent of the rat livers were exposed to complete IO (hepatic artery + portal vein) or to TVE (IO + hepatic vein) for 30 or 60 min. DNA strand breaks following blood flow interception were measured using the in situ nick translation technique as an indicator of liver damage. IO/TVE were performed on pigs as well under portosystemic bypass, and the oxygen saturation of the hepatic venous blood (SahvO2) was altered by changing the fraction of inspiratory oxygen or by oxygenating the inferior caval blood using an extracorporeal membrane oxygenator. The changes in SahtO2 were measured sequentially using near-infrared spectroscopy. The results were as follows: (1) DNA injury occurred more severely under TVE than under IO of the rat liver at the end of ischemia, as well as 30 min after revascularization. (2) SahtO2 during TVE was significantly lower than that during IO. (3) The increase in SahvO2 by oxygenation of the inferior caval blood resulted in the elevation of SahtO2 under IO. In conclusion, TVE could cause greater damage to the liver than IO due to the lack of the hepatic venous blood. Hepatic venous blood might play an important role in hepatic tissue oxygenation in the case of hepatic blood flow interception.

Animals↗
PubMed1998

Revision of ventriculo-peritoneal shunt under laparoscopic guidance in patients with hydrocephalus.

Ventriculo-peritoneal (V-P) shunt is a common treatment for hydrocephalus. However, shunt insufficiency due to obstruction, dislocation, and detachment of the peritoneal tube is frequently encountered. We designed a new technique in which the peritoneal tube is inserted into a target site of the abdominal cavity under laparoscopic guidance. We operated on 9 patients with hydrocephalus using this technique. Shunt insufficiency of the peritoneal tube had been observed in all patients, and 7 patients had undergone repeated revision of the peritoneal tube before this procedure. Our laparoscopic-assisted method ensured tube insertion into the appropriate site, and minimized the abdominal wound and postoperative adhesions. This method also made it possible to differentiate abdominal pain induced by shunt failure from pain caused by other diseases, including appendicitis. In conclusion, we consider this new technique for V-P shunt performed under laparoscopic guidance to be very useful.

Humans↗
PubMed1997

Overcoming CPT-11 resistance by using a biscoclaurine alkaloid, cepharanthine, to modulate plasma trans-membrane potential.

Irinotecan, 7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxycamptothecin, (CPT-11) resistance was overcome by using a biscoclaurine alkaloid, cepharanthine, in CPT-11- and multidrug-resistant 50MT-1 cells. 50MT-1 cells were established from a mouse breast-cancer cell line, FM3A, by subjecting the cells to a low dose of CPT-11 continuously. 50MT-1 cells exhibited resistance to CPT-11 (40-fold in colony-formation assay) and to other drugs such as doxorubicin (11.7-fold) and etoposide (VP-16) (16.8-fold). The plasma trans-membrane potential was lower in 50MT-1 cells than in FM3A cells, although there were no differences in expressions of P-glycoprotein and of DNA topoisomerase-I and -II proteins. The lower membrane potential in 50MT-1 cells was augmented by co-treatment with a non-toxic dose of cepharanthine. CPT-11 resistance in 50MT-1 cells was overcome (5.0- to 1.4-fold, 6-hr exposure) by the co-treatment with cepharanthine through increasing intracellular accumulation of CPT-11. Resistance to doxorubicin and VP-16 was also overcome by cepharanthine treatment (2.5- to 0.69-fold and 4.2- to 1.4-fold respectively). We conclude that the modification of plasma trans-membrane potential by cepharanthine should be effective in overcoming CPT-11 and multidrug resistance in 50MT-1 cells.

Alkaloids↗
PubMed1997

Cycloheximide induces a subset of low temperature-inducible genes in maize.

To investigate further the signal transduction pathway that mediates the cold-stress response in maize, we isolated a low temperature-inducible cDNA clone (ZmCDPK1) that encodes a calcium-dependent protein kinase. Time-course experiments revealed that the low-temperature induction of ZmCDPK1 precedes that of mlip15, another cold-inducible gene that codes for a DNA-binding protein of the basic region/leucine zipper (bZIP) type, indicating that ZmCDPK1 might be located upstream of mlip15 in the cold-stress signal transduction pathway. We observed that the steady-state mRNA level of mlip15 drastically increased after cycloheximide treatment. In addition to mlip15, cycloheximide elevates the transcript levels of two other low temperature-induced genes, ZmCDPK1, and Adh1, which encodes alcohol dehydrogenase 1. In contrast, the chalcone synthase gene was only inducible by low temperature. The accumulation of the mlip15 transcript at low temperatures and in response to cycloheximide was significantly reduced by pretreatment with a calcium chelator, suggesting that calcium is involved in both cases of mlip15 induction. The signal transduction pathways triggered by low temperature and cycloheximide are discussed in relation to these observations.

Amino Acid Sequence↗
PubMed1997

Role of exogenous L-arginine in hepatic ischemia-reperfusion injury.

Plasma L-arginine is usually deficient immediately after hepatic reperfusion in orthotopic liver transplantation, which may also contribute to the occurrence of either hepatic ischemia-reperfusion injury or pulmonary hypertension. In this study, exogenous L-arginine was thus experimentally used to reverse the deficient status of the L-arginine/NO pathway. An in vivo model of 1 hr hepatic ischemia and reperfusion was thus tested in both rats (Experiment A) and pigs (Experiment B). In Experiment A, 10 mg/kg of L-arginine (group 1, n = 7), D-arginine (group 2, n = 7), or saline (group 3, n = 7) was administered through the portal vein. The hepatic tissue blood flow, at 20 min after reperfusion, improved in group 1 (70.7 +/- 7.0% of the preclamp levels) compared to groups 2 and 3. The serum glutamate oxaloacetate transaminase levels at 24 hr after reperfusion were also lower in group 1 (320 +/- 22.2 IU/L) than in either group 2 or group 3. The intrahepatic NO levels showed a temporal burst (> 15,000 pA current) after reperfusion only in group 1. In Experiment B, 10 mg/kg of L-arginine (group 4, n = 5), D-arginine (group 5, n = 5), or 10 ml of saline (group 6, n = 5) was administered through the portal vein. In group 4, the MPAP (mean pulmonary arterial pressure)/MAP (mean arterial pressure) was lower than that observed in groups 5 and 6. In conclusion, exogenous L-arginine administered from the portal vein was thus found to be effective in mitigating both portal hypertension and reperfusion injury by producing an increased amount of NO immediately after reperfusion.

Animals↗
PubMed1997

The production and clearance of endothelin and its influence on kidney function after liver transplantation in rats.

To assess the involvement of endothelin-1 (ET-1) in rat liver allograft rejection, we evaluated ET-1 expression in tissues obtained from BN (RT1n) to BN rats (group 1), and DA (RT1a) to BN rats (group 2). The ET-1 levels in group 1, determined by radioimmunoassay, remained low in the serum, liver, and bile, but in group 2, they peaked on postoperative day (POD) 5 in the liver, kidney, bile, and urine, at 344 +/- 31.6 pg/gwet, 306 +/- 97.4 pg/gwet, 1008 +/- 258 pg/day, and 156 +/- 45 pg/day, respectively, whereas levels in the serum peaked on POD 7 at 38.7 +/- 13.1 pg/ml. In the portal vein (PV) ET-1 showed extremely high levels without statistical difference between groups 1 and 2, at 93.0 +/- 15.5, and 83.0 +/- 9.84 pg/ml on POD 7, respectively. However, in the suprahepatic vena cava (SHVC) and the abdominal aorta (AO), the ET-1 levels were statistically higher in group 2 compared to group 1 (P < 0.01). Immunohistochemical staining showed decreased staining of the liver and kidney in group 2 on POD 7. In conclusion, increasing levels of ET-1 were released from the liver and kidney during the early stage of rejection, resulting in the high ET-1 levels in these tissues, which were cleared promptly. However, an increased production of ET-1 was not observed in association with the release of ET-1.

Animals↗
PubMed1997

Involvement of endothelin in graft-versus-host disease after rat small bowel transplantation.

Endothelin (ET-1) expression was evaluated by radioimmunoassay in both plasma and various tissue specimens serially obtained from LBN-F1 recipients of LEW heterotopic small bowel allografts. The recipients showed graft-versus-host disease (GVHD), which histologically became apparent on postoperative day (POD) 13. The ET-1 levels peaked on POD 9 in the kidney, lung, and host intestine at 51.0 +/- 21.1, 90.9 +/- 59.6, and 25.4 +/- 11.8 pg/g wet, respectively, and peaked on POD 11 in the plasma at 7.7 +/- 3.2 pg/ml; thereafter, they decreased to basal levels in both the plasma and tissue specimens on POD 13. An immunohistochemical study of these organs showed a corresponding increase in ET-1 staining in both the endothelial and epithelial cells on PODs 5 and 9, and a reduction in staining on POD 13. In conclusion, ET-1 was found to be increasingly released from the target cells of GVHD before any histological changes became apparent, thus suggesting the pathophysiological involvement of ET-1 in intestinal GVHD.

Animals↗
PubMed1997

Adenovirus-mediated gene transfer using in-situ perfusion of the liver graft.

To establish an efficient technique for adenovirus-mediated gene transfer in liver transplantation, we evaluated the in situ perfusion of liver grafts. The grafts were perfused in situ with 1 x 10(10) of E1-deleted, replication-defective adenoviral vectors encoding the LacZ gene driven by the human CMV promoter, either through the hepatic artery (group 1) or the portal vein (group 2). Group 3 animals served as negative controls; their liver grafts were perfused with lactated Ringer's solution through the portal vein. PCR confirmed the presence of viral DNA in every graft perfused with viral vectors. In X-gal staining, positive staining was observed almost exclusively at the portal triad in group 1, whereas in group 2 minimal staining was observed, predominantly in the parenchymal area. Protein production from the transfected gene was confirmed by a functional protein assay; the values were 0.16% +/- 0.07% liver protein in group 1, 0.13% +/- 0.02% in group 2, and 0.007% +/- 0.0003% in group 3 on postoperative day 2. In conclusion, in situ perfusion of the viral vectors through the hepatic artery resulted in an effective expression of the transfected gene, predominantly at the portal triad.

Adenoviridae↗
PubMed1997

The effect of cyclosporin on endothelin levels after orthotopic liver transplantation in rats.

To assess the effects of cyclosporin (CyA) on endothelin-1 (ET-1) in rat liver allograft rejection, we evaluated ET-1 expression in samples obtained from BN(RT1n)-to-BN (group 1) rats, DA(RT1a)-to-BN (group 2) rats, and DA-to-BN rats treated with 5 mg/kg per day of CyA (group 3). Serum and hepatic ET-1 levels, determined by a radioimmunoassay, remained unchanged in group 1. In group 2, the ET-1 levels peaked on postoperative day (POD) 5 in the liver at 344 +/- 31.6 pg/g wet, and on POD 7 in the serum at 38.7 +/- 13.1 pg/ml. In group 3, hepatic and renal ET-1 levels showed a progressive increase until POD 10, while serum ET-1 levels remained unchanged. In conclusion, acute rejection caused a temporary increase in the ET-1 level in both the serum and the liver in the early postoperative period what might have been caused by endothelial damage due to ongoing, acute rejection. CyA caused a time-dependent increase in the ET-1 level in both the liver and the kidney without an increase in the serum ET-1 level. The serum ET-1 level might have been affected by the clearance of ET from the liver or kidney.

Animals↗