[Gene transfer into non-dividing cells by a lentiviral vector].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to T Shimada.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Effects of freezing, thawing, and storage at room temperature of human liver samples on the contents and catalytic activities of individual forms of cytochrome P450 (P450 or CYP) were examined. The stability of liver genomic DNA was also investigated. There were no significant decreases in microsomal levels or catalytic activities of P450 enzymes by storage at -80 degrees C for 5 years. We then examined the effects of freezing/thawing of liver samples. Levels of P450 forms were determined immunochemically and by the activities of typical drug oxidation reactions in liver microsomes of human samples, which were divided into two groups. One group of samples was thawed and kept at 25 degrees C for 6 hr and then frozen again and kept for 1 week at -80 degrees C. In the other group, liver microsomes were prepared at the same time (as those from the other group), but not thawed and refrozen. Thawing the liver samples and storage for 6 hr at 25 degrees C decreased contents of total P450 by about 90% and activities of both NADH-ferricyanide and NADPH-cytochrome c reductases by about 80%. However, the decrease in b5 levels was only about 30%. Spectral studies of P450 suggested that thawing the liver samples and holding them at 25 degrees C produced inactive form P420. P450 proteins were detected by immunoblot analysis with or without thawing, but catalytic activities for individual P450s were decreased drastically by thawing and holding samples for 6 hr at 25 degrees C. Only 10% of tolbutamide methyl hydroxylation activity was present, and there was no detectable ethoxyresorufin O-deethylation activity in such microsomes after thawing and holding samples for 6 hr at 25 degrees C. Genomic DNA from human livers was also found to be degraded after the samples were thawing. These results suggested that thawing and holding the liver samples at 25 degrees C decreased the levels and activities of P450s in microsomes and that there are differences in stabilities in individual forms of P450 proteins. P450 proteins determined immunochemically do not always reflect P450-catalytic functions in human liver microsomes because of difficulties in obtaining fresh liver samples.
Recently, dual chamber pacing has been proposed as a new treatment for left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). However, dual chamber pacing may be detrimental to both systolic and diastolic function of the left ventricle, particularly at short atrioventricular (AV) delay. A 45-year-old man and a 58-year-old woman with HOCM underwent transesophageal echocardiography and hemodynamic study at various AV delays (50-200 msec). In both patients, shortening of AV delay increased pulmonary capillary wedge pressure. The transesophageal echocardiographic study showed a remarkable shortening of the ventricular filling duration at atrial systole and an increase of pulmonary venous reversal at short AV delay (50-100 msec). Therefore, short AV delay was detrimental to diastolic filling and thus increased pulmonary capillary wedge pressure. Transesophageal echocardiographic study may be helpful for defining the optimal AV delay more precisely in HOCM during dual chamber pacing.
We have developed the RI plethysmography, and have applied it to ordinary clinic diagnosis and the evaluation of treatment. The subjects were 58 cases (39 cases of the obstruction of the peripheral blood circulation: ASO 24 cases, TAO 4 cases and arterial sclerotic change 11 cases; the non-abnormal control was 19 cases). The clinical benefit of this method was evaluated. In the cases with 1 and 2 degrees of Fontaine's classification and ASO and TAO, the blood flow of legs measured by our method significantly decreased in association with symptoms and angiographic findings. This method is suitable to the determination of angiography and evaluation of the effect of treatment.
Human cytochrome P450 (P450) 1B1 (CYP1B1) has recently been shown to be an important enzyme in the activation of diverse procarcinogens such as arylarenes, nitroarenes, and arylamines to reactive metabolites that cause DNA damage in the cells. However, it is not known whether this P450 enzyme also plays roles in the oxidation of certain drugs or model substrates commonly used in P450 assays. We examined the substrate oxidation activities of recombinant human CYP1B1 in yeast microsomes and compared these activities with those catalyzed by reconstituted systems containing recombinant CYP1A1 and CYP1A2 which were isolated from membranes of Escherichia coli in which respective cDNAs have been expressed. Catalytic activities towards some of the model substrates of other human P450 enzymes including CYP2A6, 2C9, 2C19, 2D6, 2E1, and 3A4 were also determined and compared. CYP1B1 catalyzed benzo[a]pyrene 3-hydroxylation at rates lower than those of CYP1A1 but higher than those of CYP1A2. The activity towards 7-ethoxyresorufin O-deethylation catalyzed by CYP1B1 was about one-tenth of that of CYP1A1, but the Km values were lower for CYP1B1 than those for CYP1A1 and CYP1A2. CYP1B1 was also able to catalyze the oxidation of theophylline and caffeine, two prototypic substrates for CYP1A2. CYP1B1 did not oxidize other typical P450 substrates such as coumarin, tolbutamide, S-mephenytoin, chlorzoxazone, nifedipine, and testosterone, while low rates of oxidation of bufuralol and 7-ethoxycoumarin were found for CYP1B1. These results indicate that CYP1B1 has catalytic activities overlapping CYP1A1 and CYP1A2 with respect to the oxidation of drugs and model P450 substrates, although the relative catalytic roles in these three P450 enzymes differ depending upon the substrates examined. A distinct marker activity of CYP1B1 has not been identified.
We evaluated the antithrombogenicity of 4F-catheters coated with the new antithrombogenic material fluorine-acryl- styrene-urethane-silicone (FASUS) graft-block copolymer by dissecting microscopic and scanning electron microscopic observations. These catheters were temporarily used for the infusa-A-port, which was prepared for the treatment of four patients with bladder cancer. Two heparin-coated catheters were also evaluated. All FASUS-coated catheters contained thrombi consisting of red thrombi and/or fibrin thrombi. Massive red thrombus was seen at the site of curvature of the catheters, 1 cm distal to the tip of the catheter. However, the portion 20 cm distal to the tip of the catheter had no red thrombus, but contained minimal fibrin thrombus or plasma protein. The heparin-coated catheters showed the same findings as the FASUS catheters. The FASUS-coated catheters were not superior in antithrombogenicity to the heparin-coated catheters. It was concluded that the FASUS-coated catheters used in this study seemed to have problems in regard to their preshaped curvature and the material used in catheter. These aspects need to be improved.
We report the case of an 18-year-old man with status asthmaticus who was treated with inhaled isoflurane and intravenous isoproterenol. The patient was intubated and mechanical ventilation was began immediately after admission to the hospital. He received intravenous methylprednisolone and aminophyline, and frequent inhalation of isoproterenol aerosol. However, his respiratory status deteriorated: peak inspiratory pressure increased markedly, and right pneumothorax, right lower lobe atelectasis, and hypotension developed. He was then given isoflurane by inhalation and a continuous intravenous infusion of isoproterenol, which was followed by marked improvement in his respiratory and hemodynamic status. Isoflurane can be effective in patients with status asthmaticus, and it does not increase the arrhythmogenicity of catecholamines. Intravenous administration of isoproterenol can also be useful in the treatment of patients with status asthamticus. The combination of isoflurane with intravenous isoproterenol may be useful when status asthmaticus is hard to control with conventional therapy.
67Ga scintigraphy was performed in 17 patients with chronic bronchial asthma to grasp the inflammatory change of respiratory tract. On 67Ga scintigraphy, abnormal accumulations were detected on lung fields in 6 cases (35.3%) of 17 cases. In 5 cases of these 6 cases, the defect areas which were pointed out on 81mKr ventilation scintigraphy were matched to the abnormal accumulation areas which were pointed out on 67Ga scintigraphy. In dynamics, the abnormal accumulation areas which were pointed out on 67Ga scintigraphy were matched to the defect areas which had been at all times pointed out on 81mKr ventilation scintigraphy. 67Ga scintigraphy was expected to be one of index to grasp the inflammatory change of respiratory tract in patients with chronic bronchial asthma.
To help establish an effective gene therapy protocol for patients with congenital metabolic diseases, we evaluated retrovirus-mediated transduction and long-term (LT) expression of the NeoR gene in cryopreserved and thawed CD34+ cells purified from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood (PB) of infant and cord blood (CB). The results were compared with those in bone marrow (BM) CD34+ cells. The final purity of the CD34+-enriched fraction from PB, CB, and BM, based on FACS analysis, was 88 +/- 14%, 73 +/- 13%, and 68 +/- 19% (mean +/- SEM), respectively. Cells were then cultured for 96 hours with supernatant containing the vector in the presence of interleukin (IL)-3, IL-6, and stem cell factor (SCF). The average efficiency of gene transfer into mobilized PB (n = 5) or CB CD34+ cells (n = 6) was significantly higher than that into BM CD34+ cells, as measured by G418-resistant colony-forming units for granulocyte/macrophage (CFU-GM; 59% or 58% vs. 39%; p < 0.05) and PCR-positive CFU-GM (83% or 79% vs. 53%; p < 0.05). When the evaluation was made in an LT culture system with irradiated allogeneic marrow stroma, these efficiencies were, respectively, 74% or 61% vs. 34% (p < 0.005 or < 0.02) for G418-resistant CFU-GM at week 5 of long-term culture, and 88% or 83% vs. 63% (p < 0.05) for PCR-positive CFU-GM. Fluorometric examination was performed for cell-cycle analysis before and after culture, and the results showed that the fraction of cycling cells was largest in freshly prepared BM (18%), whereas only a small portion of PB (4.6%) and CB (2%) was cycling. However, this value was 17% in BM, 22% in PB, and 13% in CB after culture. These results suggest that mobilized PB from small children and CB cells are suitable and realistic targets for clinical gene therapy and that tandem transduction procedures can be achieved by combining CB and PB.
Adeno-associated virus (AAV) is a non-pathogenic, replication defective parvovirus. In the absence of helper adenovirus, AAV stably integrates into a defined region of human chromosome 19. Because of these unique properties, recombinant AAV is considered to be an attractive vector for human gene therapy. It has been demonstrated that AAV vectors are capable of efficient transduction of various types of cells including hematopoietic cells and post mitotic neuronal cells. We have recently developed a new strategy for large scale preparation of high titer AAV vectors by using packaging cell lines and sulfonated cellulose column chromatography. This new strategy may be important for further development of gene therapy using AAV vectors.
Combined treatment with preoperative chemotherapy and surgical resection is the universally accepted effective treatment of mediastinal yolk sac tumors. However, a problem on the need and efficacy of lymph node dissection in mediastinal yolk sac tumors has been not enough discussed in the past. We reported a case of mediastinal yolk sac tumor with nodal metastasis. As described in this paper, the resection of the primary lesion including the regional lymph nodes en bloc should be recommended for mediastinal yolk sac tumors.
A DNA mismatch repair system exists that repairs mispaired bases formed during DNA replication and genetic recombination. Genetic defects in this mismatch repair system are known to increase the rate of spontaneous mutation in Escherichia coli. Some cases of inherited cancer are associated with inherited defects of mismatch repair genes, showing the importance of the mismatch repair system in maintenance of genetic stability and avoidance of cancer susceptibility. This review focused on what is known about the mechanisms of mismatch repair in human cells and the relationship between defects in mismatch repair and carcinogenesis.
The case of a patient with systemic lupus erythematosus (SLE) is reported which was accompanied by renal dysfunction and massive vascular immune deposits in the kidney without active glomerular lesions. The renal biopsy showed arterioles and small arteries with circumferential periodic acid-Schiff (PAS) and Masson trichrome-positive homogenous material in the subendothelial area in the absence of thrombotic, necrotizing or inflammatory lesions. Immunofluorescence and electron microscopy examination demonstrated immune deposits in the vascular walls. Glomeruli showed only minor abnormalities with a trend to collapse. There was no improvement in renal dysfunction over a 4-year period until the patient's death, despite steroid therapy producing a decrease in disease activity. The autopsy showed similar vascular changes to those seen in the biopsy, however; glomeruli were either sclerotic or showed a trend to collapse. Massive uncomplicated vascular immune complex deposition without active glomerular lesions is rare. The present case indicates that this type of lupus vasculopathy may be a prognostic factor for the loss of renal function in SLE mediated by hemodynamic glomerular injury.
Omeprazole 5-hydroxylation and sulfoxidation activities were determined in liver microsomes of different humans whose levels of individual forms of cytochrome P450 (P450 or CYP) varied. Correlation coefficients between omeprazole 5-hydroxylation activities (when determined at a substrate concentration of 10 microM) and S-mephenytoin 4'-hydroxylation and testosterone 6beta-hydroxylation activities were found to be 0.64 and 0.67, respectively, in liver microsomes of 84 human samples examined. Omeprazole sulfoxidation activities in these human samples were correlated with testosterone 6beta-hydroxylation activities (r = 0. 86). Omeprazole 5-hydroxylation by liver microsomes of a human sample that contained relatively high levels of CYP3A4 and low levels of CYP2C19 were inhibited very significantly by ketoconazole and anti-CYP3A4 antibodies, although a human sample having high in CYP2C19 and low in CYP3A4 was found to be sensitive toward fluvoxamine and anti-CYP2C9 antibodies. Sulfaphenazole (at 100 microM) did not affect the omeprazole 5-hydroxylation and sulfoxidation catalyzed by human liver microsomes. Both recombinant human CYP2C19 and CYP3A4 enzymes had activities for omeprazole 5-hydroxylation, with low Km and high Vmax values for the former enzyme and high Km and low Vmax values for the CYP3A4. These results suggest that contributions of CYP2C19 and CYP3A4 in the omeprazole 5-hydroxylation depend upon the ratio of these two P450 levels in human liver microsomes. Omeprazole 5-hydroxylation activities of different human samples were found to be related to predicted values calculated from the kinetic parameters of recombinant enzymes and the levels of liver microsomal CYP2C19 and CYP3A4 enzymes. Finally, when recombinant human CYP2C19 and CYP3A4 were mixed at levels found in different human samples, relatively similar profiles of omeprazole oxidation by the recombinant and microsomal enzyme systems were determined by analysis of high-performance liquid chromatography. These results suggest that both CYP2C19 and CYP3A4 are involved in the 5-oxidation of omeprazole (at a substrate concentration of 10 microM) in human liver microsomes and that contributions of these P450 enzymes depend on the compositions of CYP2C19 and CYP3A4 in liver.
Helicobacter pylori (H. pylori) has been shown to stimulate secretion of IL-8, a CXC-chemokine, from gastric epithelial cells, and this process is important in the induction of gastric mucosal inflammation associated with H. pylori infection. However, considering the biological effects and target cells, CC-chemokines may also be playing an important role in H. pylori-associated gastritis. In the present study, we investigated the expression of IL-8 (CXC-chemokine), MCP-1 (CC-chemokine), and RANTES (CC-chemokine) in human gastric mucosa by RT-PCR analysis. The positive rates of IL-8, MCP-1, and RANTES in 35 patients were 68.5%, 80%, and 80% respectively, suggesting the possible importance of CC-chemokines. We next examined the production of MCP-1 by MKN28 gastric epithelial cells. MKN28 cells were found to secrete MCP-1 in response to IL-1 beta or TNFalpha in a dose- and time-dependent manner. Quantitative RT-PCR analysis showed the induction of MCP-1 mRNA by these proinflammatory cytokines. Co-culture with H. pylori also induced the expression of MCP-1 mRNA. These results suggest that gastric epithelial cells secrete CC chemokine MCP-1 in response to proinflammatory cytokines and H. pylori, and this process may also be important in the chronic gastric inflammation associated with H. pylori infection.
Surgical excision of both primary and metastatic tumors is the recommended therapy for gastric cancer. There are many cases of multiple metastasis to lymph nodes, disseminated metastasis of peritoneum, and post-operative systemic metastasis for which no surgical treatment is available. Cancer gene therapy is one of the promising new techniques. We injected the suicide gene, herpes simplex virus thymidine kinase (HSV-tk), directly into the tumor using gastrofiberscopy. Following GCV treatment caused tissue degeneration at the injection site and lymph nodes. These findings show that suicide gene therapy for gastric cancer may be effective for a metastatic tumor along with the primary tumor.
Explore the source record for details and available documents.