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H Imoto

Publications and source records attributed to H Imoto.

28 records · Page 2Linked to original sources
PubMed1993

Molecular cloning of polymorphic markers on RLGS gel using the spot target cloning method.

A new method for target cloning of DNA fragments corresponding to spots on the two-dimensional restriction landmark genomic scanning (RLGS) profile has been developed (targeted spot cloning). We used a Not I restriction trapper to select target DNA fragments from Not I, Eco RV double digests of genomic DNA. The use of the restriction trapper substantially reduces the background clones that are established from the direct recovery of RLGS spot DNA from the two-dimensional gels. Genomic DNA clones were isolated in this study as mouse genome markers for 58 spot loci that were previously characterized using RLGS spot mapping. This method provides a powerful tool for isolating DNA clones after their identification by RLGS system.

Animals↗
PubMed1992

Disposition characteristics of macromolecules in the perfused tissue-isolated tumor preparation.

Disposition characteristics of model macromolecules with different physicochemical characteristics and macromolecular prodrugs of mitomycin C, namely mitomycin C-dextran conjugates, were studied in tissue-isolated tumor preparations of Walker 256 carcinoma with the use of a single-pass vascular perfusion technique. In constant infusion experiments, all radiolabeled macromolecules accumulated in the tumor tissue, but the degree and pattern of distribution greatly varied, depending on their electric charges. Positively charged macromolecules were markedly accumulated compared with those that were neutral or negatively charged. In addition, their concentrations were significantly higher in viable than in necrotic regions, while neutral and negative compounds were distributed in necrotic rather than in viable regions. Pharmacokinetic analysis of tissue concentration-time courses of positively charged diethylaminoethyl and neutral dextrans showed that their movement occurred by convective fluid flow, and that high tissue accumulation of positively charged macromolecules could be explained by strong binding due to electrostatic interaction. For neutral and anionic macromolecules with negligible affinity to the tissue, it was suggested that the final concentration gradient between the viable and necrotic regions was decided by their tissue fluid content. Thus, the present study revealed the basic disposition characteristics of macromolecules in tumor tissue relative to their physicochemical properties.

Animals↗
PubMed1990

Disposition of anticancer drugs after bolus arterial administration in a tissue-isolated tumor perfusion system.

Disposition characteristics of various anticancer drugs in a tissue-isolated tumor preparation were studied in Walker 256 carcinosarcoma-bearing rats using an in situ single-pass vascular perfusion technique. Three anticancer drugs, 5-fluorouracil, mitomycin C, and Adriamycin, and two lipophilic prodrugs of mitomycin C were tested in the tumor preparation perfused with Tyrode's solution containing 4.7% bovine serum albumin. After bolus arterial injection of test drugs, their outflow concentration-time curves were analyzed based on statistical moment theory. In each tumor preparation, the injection of drug was paired with that of vascular reference substance, Evans' blue-labeled bovine serum albumin, and disposition parameters of the drug were corrected with those of vascular reference substance. From the mean transit time values of vascular reference substance, the average vascular volume of the tumor preparation was calculated to be 0.063 ml/g, which decreased with tumor growth. All drugs showed significant extraction by the tumor tissue, depending on their physicochemical properties. Distribution volumes of tested drugs were from 1.53 to 3.33 times larger than the vascular volume. Calculated intrinsic clearance values for the protein-unbound fractions increased as the lipophilicity of the drug increased. The potential increase in tumor uptake was observed in lipophilic prodrugs of mitomycin C. The present experimental system is thus suggested to be useful for analyzing drug disposition in tumor tissue.

Animals↗
PubMed1989

[Early and late results of St. Jude Medical prosthesis in aortic and mitral portion].

January, 1980 to December, 1988, 118 patients underwent aortic (AVR) (45), mitral (MVR) (55), aortic and mitral (DVR) (21) valve replacement with a tilting disc valve prosthesis, the St. Jude Medical. Age ranged from 11 to 69 years (mean 49). There were seven death within thirty days after the surgery (AVR 1, MVR 5, DVR 1). Follow-up is complete and ranges from 1 month to 107 months (total 392, 4 patient-year (pt-yr), AVR 127.7 pt-yr, MVR 182.6 pt-yr, DVR 82.0 pt-yr). In the AVR group, three late deaths have occurred and actuarial survival at 8 years is 89 +/- 5%. Five patients have sustained thromboembolic episodes from linearized rate of 4.7%/patients-year, and the probability of remaining free of thromboembolism at 8 years is 83 +/- 7% in survivors longer than thirty days after the surgery. In the MVR group, one late death has occurred and actuarial survival at 8 years is 87 +/- 5%. Two patients have sustained thromboembolic episodes from linearized rate of 1.1%/patient-years, and the probability of remaining free of thromboembolism at 8 years is 86 +/- 1% in survivors longer than thirty days after the surgery. In the DVR group, four late deaths have occurred and actuarial survival at 8 years is 75 +/- 12%. Two patients have sustained thromboembolic episodes from linearized rate of 2.4%/patients-year, and the probability of remaining free of thromboembolism at 8 years is 85 +/- 5% in survivors longer than thirty days after the surgery. There is no significance of actuarial survival rate among three groups, but the rate of thromboembolism in AVR group is significantly higher than in other MVR and DVR groups in the first 20 months. Reoperation was carried out in one patient because of perivalvular leak. There have been no thromboses of the SJM valve and no mechanical valve failure. Because of this experience, The St. Jude Medical heart valve prosthesis is our prosthesis of choice for any patient undergoing valve replacement with a mechanical prosthesis.

Adolescent↗
PubMedDate not supplied

Conservative treatment for cervical spondylotic myelopathy. prediction of treatment effects by multivariate analysis.

BACKGROUND CONTEXT: Many studies have suggested only slight effects of conservative treatment on cervical spondylotic myelopathy (CSM), whereas a few reports describe conservative treatment as being effective. This suggested the influence of various factors on treatment outcomes. PURPOSE: We investigated symptomatic changes after conservative treatment in patients based on a clear understanding of the effects and limitations of conservative treatment. STUDY DESIGN: We have encountered cases that showed symptomatic improvement with conservative treatment and became interested in the effectiveness of conservative treatment for CSM and whether other factors affect the results of conservative treatment. PATIENT SAMPLE: We have analyzed the results of conservative treatment for CSM in 69 cases, derived from a population of 101 CSM cases. OUTCOME MEASURES: Symptoms at the time of the first examination were compared with those at the final examination, and the patients were classified into three groups showing improvement, no change or exacerbation. METHODS: Improvement or exacerbation of the symptoms was used as dependent variables and the collected factors as independent variables, and logistic regression was performed on these variables. RESULTS: Multivariate analysis showed significant correlation between clinical outcome and the disease duration and the presence of rigorous conservative treatment. CONCLUSIONS: Conservative treatment for CSM is considered to be effective if it is performed intensively in selected patients. In treating CSM, the therapeutic approach must be selected first in consideration of the patient's disease duration. Conservative treatment must be carried out intensively after sufficient explanation to the patients. Timely surgical intervention is considered to be important if the symptoms show no change or exacerbation with conservative treatment.

Adult↗
PubMedDate not supplied

Evaluations of p53 immunoreactivity, nucleolar organizer regions, and proliferating cell nuclear antigen in non-small cell lung carcinoma.

We examined p53 protein expression, proliferating cell nuclear antigen (PCNA), and argyrophilic nuclear organizer regions (AgNOR), in 102 patients with surgically-treated non-small cell lung cancer (NSCLC). p53 positive cases with DO-1 were defined when more than 10% of the tumor cell nuclei were stained. Mean AgNOR count and PCNA LI were 2.80 and 40.7 and there were no significant differences of AgNOR count and PCNA LI between p53 positive and negative cases. We assessed the relationship between the p53 immunoreactivity and various clinical or pathological parameters. p53 positive rate of stage III disease (46.3%) was significantly higher than that of stage II disease (28.6%). The p53 positive rate of squamous cell carcinoma (42.1%) tended to be higher than that of adenocarcinoma (33.9%). In the survival curves of patients with NSCLC according to the p53 immunoreactivity, there was no significant difference between p53 positive and negative cases. Eight potential prognostic parameters (p53 immunoreactivity, AgNOR count, PCNA LI, sex, age, year of operation, histology, and stage) were also estimated, using univariate and multivariate analysis. In univariate analysis, PCNA LI and AgNOR count, and stage were significantly related to shortened survival. In multivariate analysis, PCNA LI, Age, and stage were independently associated with shortened survival of NSCLC patients. PCNA staining may be more useful than p53 and AgNOR staining in assessing the aggressiveness of surgically-treated NSCLC, although the most useful clinical prognostic parameter should be achieved by the combined analysis of several prognostic indicators.

Adult↗
PubMedDate not supplied

Pleural retraction and intra-tumoral air-bronchogram as prognostic factors for stage I pulmonary adenocarcinoma following complete resection.

BACKGROUND AND OBJECTIVES: We have retrospectively analyzed the postoperative prognostic factors for 116 patients with stage I adenocarcinoma, with special reference to pleural retraction and intra-tumoral air-bronchogram imaged by computed tomography, which may represent the biological features of pulmonary adenocarcinoma for the retraction of surrounding tissues due to central necrosis and air space-lining growth, respectively. METHODS: The subgroups divided according to the presence of pleural retraction and/or intra-tumoral air-bronchogram on pre-operative CT were compared with respect to the postoperative disease-free survival (DFS) and other clinico-pathological factors. RESULTS: The rates of DFS at 5 years associated with 61 patients with pleural retraction and with 55 patients without pleural retraction were 64.4% and 91.3%, respectively (P = 0.0052), and those associated with 83 patients with air-bronchogram-positive tumors and with 33 patients with air-bronchogram-negative tumors were 81.8% and 64.8%, respectively (P = 0.0040). The DFS at 5 years associated with T1 (73 patients) and T2 (43 patients) were 83.6% and 64.3%, respectively (P = 0.0153). The Cox proportional hazards model analysis revealed that the presence of pleural retraction and the absence of air-bronchogram were independent factors for poor prognosis with relative risks of 7.8 and 5.1, respectively. Pathological T factor was also a significant prognostic factor with a relative risk of 3.2. Seventeen patients with pleural retraction-positive and air-bronchogram-negative tumors showed the high recurrence rate of 47.5% and a poor prognosis with DFS at 5 years of 35.1%. CONCLUSION: These results suggested that, in stage I adenocarcinoma, the degree of malignant potential may be well figured by radiological imaging, with a significant affect on susceptibility of recurrence following complete resection.

Adenocarcinoma↗