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N Tanigawa

Publications and source records attributed to N Tanigawa.

At least 91 records · Page 5Linked to original sources
PubMed1996

Tumor angiogenesis and expression of thymidine phosphorylase/platelet derived endothelial cell growth factor in human gastric carcinoma.

To investigate the relationship between tumor angiogenesis and the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/dThdPase) and between patients' survival and the expression of PD-ECGF/ dThdPase in human gastric carcinoma tissues, we performed immunohistochemical studies with anti-PD-ECGF/dThdPase and anti-CD34 monoclonal antibodies. Out of 154 gastric carcinoma tissue samples, 61 (40%) were evaluated as PD-ECGF/ dThdPase-positive. The expression of PD-ECGF/dThdPase was significantly associated with the intratumoral microvessel counts (P < 0.0001) and the incidence of hematogenous metastasis (P < 0.05). Intratumoral vessel counts were significantly correlated with overall survival of 154 patients (P < 0.000001). Cox proportional hazards model showed that tumor vasculature was an independent and strong prognostic variable. However, the prevalence of the expression of PD-ECGF did not associate the overall survival. We suggest that expression of PD-ECGF/dThdPase plays a role in the promotion of angiogenesis in human gastric carcinomas, without any definite influence on patient's survival.

Adenocarcinoma↗
PubMed1996

Extent of tumor vascularization correlates with prognosis and hematogenous metastasis in gastric carcinomas.

To determine whether tumor angiogenesis correlates with prognosis and metastasis of patients with gastric carcinoma, we counted the microvessels within the primary carcinoma and compared their numbers with the patient's prognosis and mode of metastasis. Tumor specimens from 110 patients with gastric carcinoma, who had undergone curative resection more than 24 months before, were investigated. Intratumoral microvessels were stained with anti-CD34 and anti-von Willebrand factor monoclonal antibodies before being quantitated by light microscopy (x200). The antibody against von Willebrand factor often showed variability and stromal background staining, providing misleading low vessel counts. The data from three patients who died from nongastric carcinoma within 24 months after surgery were deleted. A total of 107 patients took part in the analysis examining the association between intratumoral microvessels and clinical outcomes. Vessel counts derived from CD34 expression were significantly higher in patients who experienced hematogenous or peritoneal metastasis after surgery than in patients with nonmetastatic tumors. No correlation between vessel counts and lymph node metastasis was found. The prevalence of hematogenous metastasis. but not peritoneal metastasis, increased as the vessel counts increased. Multivariate logistic regression and Cox hazards model analyses showed that the vessel counts obtained with CD34 staining correlated with the development of hematogenous recurrence but not peritoneal recurrence. It was the most important factor for predicting overall survival. These findings support the hypothesis that tumor angiogenesis is closely related to the development of hematogenous metastasis in human gastric carcinomas. Assessment of tumor vascularization may, therefore, prove valuable in identifying patients with gastric carcinoma at high risk for recurrence who would benefit from adjuvant therapy.

Adenocarcinoma↗
PubMed1995

Optimal cycles of hepatic ischemia and reperfusion for intermittent pedicle clamping during liver surgery.

OBJECTIVES: To evaluate the intermittent clamping of hepatic vessels during liver surgery and to determine the optimal duration of ischemia and reperfusion. PARTICIPANTS: One hundred nine adult male Sprague-Dawley rats. METHODS: Partial (70%) ischemia of the rat liver was induced by clamping of the left pedicle. To assess the influence of a single period of ischemia, the rats were divided into three groups for 15, 20, or 30 minutes of ischemia. To evaluate the influence of reperfusion duration, reperfusion following 15-minute ischemia was repeated 10 times in three groups for 5, 10, or 15 minutes of reperfusion duration. Hepatic tissue blood flow (HTBF) and hepatic beta-adenosine triphosphate (beta-ATP) levels were measured serially, and histopathological specimens were studied following single episodes of ischemia. In the reperfusion experiments, hepatic enzyme levels, survival rates, HTBF, beta-ATP, and histopathological findings were analyzed. RESULTS: When the single period of ischemia was 15 minutes, HTBF and beta-ATP levels recovered after 1 hour of reperfusion. However, both HTBF and beta-ATP levels did not return to preischemic levels when the duration of the ischemia was 20 or 30 minutes. Levels of beta-ATP and HTBF were higher, with improvement in both the histopathological findings and the survival rate, when the duration of the repeated reperfusion periods was 15 minutes, compared with 5 or 10 minutes. CONCLUSIONS: The maximum period of ischemia without irreversible damage was 15 minutes in rat liver. The damage was less severe when the duration of the repeated reperfusion periods was 15 minutes rather than 5 or 10 minutes.

Adenosine Triphosphate↗
PubMed1995

Clinical significance of multidrug resistance and P-glycoprotein expression in patients with gastric carcinoma.

Twenty-four fresh tumors of gastric carcinoma were assessed by flow cytometric detection of P-glycoprotein (P-gp) using monoclonal antibody C219. Eight patients were P-gp positive. Differentiated gastric carcinomas contained significantly higher concentrations of P-gp positive. Incidence of P-gp positive was high in advanced stage. In 16 cases estimated chemosensitivity was test assessed by thymidine incorporation assay (TIA). Seven of nine multidrug-resistant cases according to TIA were P-gp positive and all of seven nonmultidrug resistant cases were P-gp negative. Expression of P-gp and multidrug resistance were closely correlated (P < 0.01). Also, in 89 patients with operable gastric carcinoma, the relation between in vitro chemosensitivity test (TIA) and their clinicopathologic features as well as their survival lengths were studied. Thirty-one of 89 specimens from gastric carcinoma patients were multidrug resistant according to TIA. Patients in the multidrug-resistant group had a significantly poorer cumulative survival rate than those who were not multidrug resistant (P < .05). The multivariate analysis showed that multidrug resistance is a useful indicator of prognosis (P < 0.1). We suggest that multidrug-resistant cases or P-gp-positive cases of gastric carcinoma are highly malignant, and these determinations are clinically useful.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Reaction of the aortic wall to six metallic stent materials.

RATIONALE AND OBJECTIVES: We investigated the effects of various metallic stents on the aortic wall. METHODS: The wires of Gianturco-type expandable metallic stents were plated with gold, silver, or copper or coated with Teflon or silicone. Stents were inserted into the aortas of 15 adult mongrel dogs. The time course of radiologic, macroscopic, and histologic changes in the aorta at the site of the stent was investigated at 1, 2, and 4 weeks after implantation. RESULTS: The gold-plated stent appeared to produce fewer macroscopic and histopathologic changes in the aorta than the other types of stents. The neointima was thinnest with gold (83.9 +/- 40.3 microns), followed by stainless steel (103.6 +/- 57.0 microns), Teflon (115.0 +/- 30.2 microns), silicone (209.6 +/- 25.9 microns), silver (228.6 +/- 33.8 microns), and copper (unmeasurable). With the copper-plated stent, the aorta suffered severe erosion of the vessel wall, marked thrombus formation, and aortic rupture. CONCLUSION: Gold is a useful intravascular material because it reacts only minimally with the vessel wall.

Animals↗
PubMed1995

Water jet angioplasty--an experimental study.

The usefulness and safety of water jet angioplasty was studied in vitro, using agar phantom and autopsied aorta, and in vivo in acute and chronic arterial occlusions in mongrel dogs. At an injection rate of 1.0 ml/s, the water jet produced erosion of the agar surface when the distance between the catheter and the agar was 1 mm. With an injection rate of 1.5 ml/s, erosion was produced at a distance of 15 mm from the catheter tip. When the water jet was directed at an arterial wall, intimal ablation and ruptured elastic fibers were found histopathologically. A smaller angle between the vascular wall and the catheter was associated with less vascular damage. In vivo, water jet angioplasty was effective against acute obstructions, but not against chronic obstructions. These results suggest that water jet angioplasty may be effective against arterial obstruction due to acute thrombus.

Agar↗
PubMed1995

[Establishment of signal-averaged electrocardiographic system and system specific criteria].

Signal-averaging of high resolution electrocardiographic data to identify ventricular late potentials, associated with ventricular tachycardia, has emerged as a useful technique for risk stratification following myocardial infarction. Multiple lead system, filters and criteria have been used in clinical trials. As variations in data analysis are introduced, it is important to assess the impact of the final results and to ensure that criteria for normalcy, appropriate for these variation, are developed if needed. This study compares the results produced by four systems and one system with a different filter used for determination of late potential parameters in the time domain. It is concluded that varying technique and filters significant changes in the values used to identify late potentials on high-resolution electrocardiographic records. These change may have clinical impact. When using this technique in a clinical situation, parameters values, appropriate for the device, and its components should be developed, if needed.

Arrhythmias, Cardiac↗
PubMed1995

[Comparison of parameters of ventricular late potentials by using four commercial high-resolution ECG systems].

The methodologic problems of non-invasive registration of ventricular late potentials (LP) were studied. Four commercially available high resolution ECG devices were used. Method A was MAC 1 from Marquette, Method B was MAC 12 (15) from Marquette. Method C was ART 101 PC from Arrhythmia Technology Research. Method D was Fukuda VCM3000 from Fukuda Denshi in Japan. Our study showed the good correlation of the filtered QRS duration (FQRSd) between method B (fast Fourier transform filter) and method C (bidirectional digital filter). However the poor correlation between method B, C (digital filter) and D (analogue filter) was obtained. When late potentials positive patients who had high frequency and low amplitude signals were compared, the worse correlation of FQRSd among method B, C and D was obtained. FQRSd in method B was longer than that in method C, and that in method D was longer than that in method B. The differences were statistically significant. The measurements of low amplitude signals [Root mean square voltage in last 40 msec (V40) and High Frequency and low amplitude signals duration under 40 microV (HFLAD)] in various methods were much difference. We concluded that the standardization of the filter and leads to evaluate the late potentials was needed. The system specific criteria to detect the sustained ventricular tachycardia have to be redefined in VCM 3000. It was important to evaluate visually LP, as LP far from QRS offset could not be registered with vector magnitude methods in individual cases.

Body Surface Potential Mapping↗
PubMed1995

[Physical properties of Strecker stents].

Strecker stent is a balloon-expandable metallic stent that is made of knitted tantalum wire mesh in order to Maintain flexibility. Therefore, the prosthesis is well suited to irregular and tortuous tube organs. We performed several physical experiments using 8 mm and 6 mm diameter stents made of 0.1 mm diameter wire filament. The bearing power of the 8 mm diameter stent against the circumferential compression pressure was divided into two groups, that is, 77-100% and under 66% of expansile rate. The capacity bearing the circumferential compression pressure of the latter group was greater than that of the former. Further, the bearing power of the 6 mm diameter stent was greater than that of the 56% expansile rate of the 8 mm diameter stent. The smaller the expansile rate of the stent, the smaller the minimum radius of curvature within the limits of the stent's plastic. To evaluate the suitability of the stent in clinical use, we made two projections on the inner surface of rubber tubes, and the stents were placed into the rubber tubes at different expansile rates. We evaluated the degree of contact of the stents against the rubber wall by taking soft X-ray photographs. The stents showed good suitability under the condition of incomplete expansion. For the above reasons, we concluded that, from the view-point of bearing power, the stent should be placed in the full expansile state. From the viewpoint of contact against the vessel wall, the stent should be placed in the incomplete expansile state.

Physical Phenomena↗
PubMed1995

[Percutaneous placement of intraluminal stent-graft for aortic dissection: experimental study].

Highly porous fabric vascular grafts fabricated of ultrafine polyester fibers (UFPF-graft; porosity, 7,000 ml, 9,000 ml, 11,000 ml at 120 mmHg) were attached between two Gianturco stents connected with two stainless steel struts. UFPF-grafts with two Gianturco stents were placed into the aortas of six adult mongrel dogs without firm contact with the luminal surface. From two days to four months after placement, all the UFPF-grafts were completely sealed with fresh thrombus or neointima. Within two months, complete endothelialization was observed on both surfaces of the neointima. In three dogs, aortic dissections were created experimentally. Then an UFPF-graft (porosity, 9,000 ml) with two Gianturco stents was placed at the site of entry of the dissection, followed by additional Gianturco stents to expand the UFPF-graft. X-ray angiography showed that the entries were closed immediately after placement, and false lumens disappeared within one hour after placement. These results indicated that the method has the possibility of treating aortic dissection with complete sealing of the fabric by the neointima.

Aortic Dissection↗
PubMed1995

[Potential and limitation of scintillation assay (TIA) for clinical chemotherapy].

The clinical significance of the scintillation assay (thymidine incorporation assay) which we developed was summarized as follows; 1)thymidine uptake by tumor cells which can be evaluated in each assay functioned as a significant predictor of prognosis of patients with gastric or colorectal cancer, 2)the tumor cell compartment in this assay system significantly increased more than did those in other culture systems, 3)evaluable rates were increased to more than 80% by introduction of the preculture system with collagen coated flasks, and 4)it can be considered that chemosensitivity testings may benefit for some types of human tumor, but not for all.

Animals↗
PubMed1994

[Preliminary report on the usefulness of 123I-IMP scintigraphy in distant metastases from hepatocellular carcinoma: except for bone and lung metastases].

N-isopropyl-p-[123I] Iodoamphetamine (IMP) scintigraphy was performed in 10 lesions of metastatic hepatocellular carcinoma. Five of 10 lesions (50%) were detected with planar images, which was superior to the 2 of 8 lesions (25%) detected with 67Ga-citrate (Ga) scintigraphy. The positive ratio was increased to 83% (5/6) with SPECT. Thus our findings suggested that IMP could compensate for Ga scintigraphy in detecting distant metastases of hepatocellular carcinoma.

Adrenal Gland Neoplasms↗
PubMed1994

[Percutaneous radiofrequency coagulation therapy for liver tumor: experimental study].

We invented a newly devised local thermal therapy using radiofrequency energy for treating liver tumors. This method was investigated for evaluating its safety and effectiveness. In vitro study, the maximum size of coagulated albumen was 5.5 to 6.2mm in diameter, and 9.8 to 11.3mm in length. In vivo study using rabbit's liver, the range of coagulated tissue by radiofrequency energy was localized around the tip of the needle. Percutaneous radiofrequency coagulation therapy will be the effective therapy for liver tumor regardless of tumor vascularity.

Animals↗
PubMed1994

Prognostic significance of in vitro thymidine uptake in patients with colorectal carcinoma.

In 127 patients with colorectal carcinoma, we measured thymidine uptake by tumor cells cultured in a semisolid medium and compared the influence of various parameters on survival by univariate and multivariate analysis. Fifty-four of the 127 carcinomas (42.5%) incorporated > 1,000 cpm of tritiated thymidine per culture dish and were designated as the high-uptake group, while the other tumors (57.5%, 73/127) were designated as the low-uptake group. There was no significant correlation between high or low thymidine uptake and most of the clinicopathological characteristics of the patients. Patients in the high-uptake had a poor prognosis and a 7-year survival rate of 32.6%, which was significantly different from the rate of 69.3% in the low-uptake group (P < 0.0005). Multivariate analysis showed that thymidine uptake was one of the variables strongly associated with survival in our study population. Thus, it is concluded that thymidine uptake by tumor cells has a high capacity of predicting prognosis, independent of its relationship to other variables. Furthermore, it seems to us that thymidine uptake can help in selecting those patients with colorectal carcinoma who are most likely to benefit from perioperative adjuvant therapy.

Adenocarcinoma↗
PubMed1994

The potential use of I-123 IMP scintigraphy for pelvic bone metastases in hepatocellular carcinoma. A comparison with Ga-67 scintigraphy.

Conventional bone scintigraphy is often inconclusive in detecting bone metastases of hepatocellular carcinoma, suggesting the necessity of alternative scintigraphic agents. In this study, the diagnostic value of I-123 IMP scintigraphy was evaluated in 8 patients with 12 pelvic bone metastases from hepatocellular carcinoma, then compared with Ga-67 scintigraphy. Eleven of 12 lesions (91.7%) were detected by I-123 IMP scintigraphy; Ga-67 scintigraphy visualized 8 lesions (66.7%) in the same patient population. I-123 IMP scintigraphy is useful for detecting pelvic bone metastases of hepatocellular carcinoma with less physiologic accumulation in the intestine as compared with Ga-67 scintigraphy.

Aged↗
PubMed1994

Intraarterial occlusion by radiofrequency.

Arterial occlusion using radiofrequency energy was performed. The length of the noninsulated part of the guidewire was 10 mm and the duration of radiofrequency supply was 20 s. Animal experiments were carried out in 17 canine arteries; 4 out of 6 arteries less than 2.3 mm in diameter were completely occluded during the 20 s radiofrequency supply. A clinical application was also successfully performed without any complications. Arterial occlusion with radiofrequency can be applied to vessels less than about 2 mm in diameter.

Animals↗
PubMed1994

[Clinical significance of P-glycoprotein expression and multidrug resistance assessed by in vitro thymidine incorporation assay in patients with gastric carcinoma].

Drug resistance in chemotherapy is a significant problem in the treatment of gastric carcinomas as well as other malignant tumors. Multidrug resistant cells frequently overexpress the 170 kDa P-glycoprotein (P-gp). Twenty-four fresh tumor specimens of gastric carcinoma were assessed by flow cytometric detection of P-gp using monoclonal antibody C219. Eight patients were P-gp positive. Differentiated gastric carcinomas contained significantly higher concentrations of P-gp positive. Incidence of P-gp positive case was high in advanced stage. Sixteen cases received in vitro chemosensitivity test assessed by thymidine incorporation assay (TIA). Seven of 9 multidrug resistant cases by TIA were P-gp positive, and all of 7 non-multidrug resistance were negative. Expression of P-gp and multidrug resistance were closely correlated (p < 0.01). Also, in 89 patients with operable gastric carcinoma, the relationship between multidrug resistance by TIA and their clinicopathologic features as well as their survival lengths were examined. Thirty-one of 89 specimens from gastric carcinoma patients were multidrug resistant by TIA. Patients with multidrug resistant group had a significantly poorer cumulative survival rate than non-multidrug resistant cases (p < 0.01). The multivariated analyses showed that multidrug resistance analyzed is useful indicator for prognosis (p < 0.1). We suggest that multidrug resistance cases or P-gp-positive cases of gastric carcinoma are highly malignant, and these determinations are clinically useful.

ATP Binding Cassette Transporter, Subfamily B, Mem↗