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T Nishibe

Publications and source records attributed to T Nishibe.

At least 37 records · Page 2Linked to original sources
PubMed2001

Lymphoepithelioma-like carcinoma of rectum: possible relation with EBV.

Lymphoepithelioma-like carcinoma (LEC) of the colon is very rare. Here we report a case of LEC originating in the rectum that was closely associated with Epstein-Barr virus (EBV) infection. The histologic and immunohistologic features, namely, poorly differentiated adenocarcinoma with lymphoid stroma, showed this tumor to be an LEC. The EBV genome was detected by PCR using DNA obtained from tumor tissue sections. Immunohistochemically, EBV-determined nuclear antigen 2 was detected in the tumor cells, and in situ hybridization using EBV-encoded small RNAs probe showed positive labeling in some tumor cells together with a few stromal lymphoid cells. There are some reports of LEC cases that originated in the colon; however, a relation with EBV was not demonstrated. We report here a case of LEC of the rectum demonstrating a possible relation with EBV.

Aged↗
PubMed2001

Femoral vein valve repair with angioscopy-assisted anterior valve sinus plication. Early results.

BACKGROUND: The efficiency of angioscopy-assisted anterior valve sinus plication for primary deep venous insufficiency was evaluated. METHODS EXPERIMENTAL DESIGN: retrospective, clinical study with short follow-up. SETTING: institutional practice. PATIENTS: 15 limbs in 12 patients had class 4 or higher disease (SVS/ISCVS classification). Descending venography showed class 3 or 4 reflux in all patients. Venous refilling time (VRT) was abnormal (<15 sec) in all of the nine limbs in which photoplethysmography was conducted. The limbs were treated with angioscopy-assisted anterior valve sinus plication of the superficial femoral vein. Postoperative descending venography was performed between the first and third day after operation. Clinical evaluation and VRT measurement were repeated when the patients were discharged and checked at the outpatient office. RESULTS: Mean follow-up was 22 weeks with a range of 1 to 70 weeks. At postoperative descending venography, the reflux of the superficial femoral vein was significantly improved. At final follow-up, all patients reported greater or lesser relief of subjective symptoms. In four limbs with class 6 disease, ulcers healed and did not recur. In one limb with class 5 disease, ulcers did not recur. In the other 10 limbs with class 4 disease, a distinct clinical improvement occurred with resolution of skin changes. VRT was normal in 11 of the 12 limbs examined. CONCLUSIONS: Our preliminary experience demonstrates that angioscopy-assisted anterior valve sinus plication gives early good clinical and hemodynamic improvement in patients with primary deep venous insufficiency.

Adult↗
PubMed2001

[Pain characteristics in disease of heart and aorta].

Chest pain or discomfort is one of the cardinal manifestations of thoracic diseases. Fast, accurate diagnosis is essential for patients with angina pectoris, acute myocardial infarction, aortic dissection, ruptured aortic aneurysms, and pulmonary embolisms, which have a high mortality if not treated immediately. In patients with ischemic heart diseases and aortic dissection, an accurate history and a chest roentgenogram can serve as helpful guides to their diagnosis, and ultrasound, computed tomography, and electrocardiography can establish the diagnosis. It is important to suspect cardiovascular emergencies based on quality, duration, and location of pain as well as the presents of hypotension or hypertension, and to start these conditions as soon as possible. Then it is necessary to assess the degree of cardiovascular disability and, if necessary, to introduce patients to cardiovascular specialists.

Cardiovascular Diseases↗
PubMed2001

Effects of fibronectin bonding on healing of high porosity expanded polytetrafluoroethylene grafts in pigs.

BACKGROUND: We developed a new fibronectin bonding to expanded polytetrafluoroethylene (ePTFE) and previously reported that, in a dog carotid implant model, fibronectin bonding improves graft healing in high porosity ePTFE grafts. The purpose of this study was to further investigate the effect of the fibronectin bonding on graft healing in a pig carotid implant model. METHODS: Fifteen pigs received a high porosity ePTFE graft treated with the fibronectin bonding (fibronectin-bonded graft) on one side and an untreated graft (non-bonded graft) on the contralateral side. The grafts were explanted at intervals of 3 and 6 weeks and subjected to histological studies. RESULTS: At 3 weeks, the neointima of fibronectin-bonded grafts was better organized than that of non-bonded grafts. At 6 weeks, the morphologic features of the neointima were the same in fibronectin-bonded and non-bonded grafts. The neointima was completely organized. CONCLUSIONS: Together with the previous results with the dog model, fibronectin bonding could be expected to improve healing of the high porosity ePTFE grafts in humans.

Animals↗
PubMed2001

Popliteal artery entrapment syndrome. Reconstruction of the transected medial head of the gastrocnemius muscle.

Popliteal artery entrapment syndrome (PAES) is an uncommon cause of arterial insufficiency, especially in younger, athletic patients. Surgical treatment should be performed in all cases of PAES whether the artery is occluded or not. Although transection of the compressing muscle or fascial band is required to obtain good results, controversy exists about reconstruction of the transected muscle or fascial band. We present a case of a young athlete with PAES for whom rapid recovery of the athletic activity was provided by reconstruction of the divided medial head of the gastrocnemius muscle.

Adolescent↗
PubMed2000

Enhanced graft healing of high-porosity expanded polytetrafluoroethylene grafts by covalent bonding of fibronectin.

The effect of covalent bonding of fibronectin on the patency and graft healing of high-porosity expanded polytetrafluoroethylene (ePTFE) grafts was evaluated. Bilateral carotid grafting was performed in ten mongrel dogs using high-porosity (60 microm) ePTFE grafts, 4 cm in length and 4 mm in internal diameter, that either had been pretreated by the covalent bonding of fibronectin (fibronectin grafts) or were untreated (control grafts). The grafts were harvested 4 to 6 weeks after surgery and subjected to macroscopic and light-microscopic observations. There was no significant difference in patency between the fibronectin grafts and the control grafts with rates of 80% and 70%, respectively. The thrombus-free area score was significantly greater in the fibronectin grafts than in the control grafts, at 86.9% vs 34.0%. Furthermore, the pseudointima was better replaced by fibrous tissue in the fibronectin grafts than in the control grafts, being lined with a layer of endothelial-like cells. More transmural tissue ingrowth was evident in the fibronectin grafts than in the control grafts. The covalent bonding of fibronectin improves graft healing by stimulating transmural tissue ingrowth in high-porosity ePTFE grafts.

Animals↗
PubMed2000

High-porosity expanded polytetrafluoroethylene grafts for thoracic vena cava replacement with or without an omentum wrap.

We previously reported that, in a short-term thoracic inferior vena cava (IVC) replacement, a high-porosity expanded polytetrafluoroethylene (ePTFE) graft (fibril length 60 microm) performed well without altering the short-term patency, and that the healing of the high-porosity ePTFE graft was accelerated by an omentum wrap. The purpose of this study was to examine the long-term performance of the high-porosity ePTFE graft with or without an omentum wrap. Eighteen grafts were placed as a thoracic IVC replacement in dogs. Nine of the grafts were wrapped in an omental pedicle flap while the other 9 were not. At 1 month and 6 months, the grafts were harvested and examined for a pathological analysis. During the observation period, one dog died of a viral infection, while the other 17 dogs survived. At 1 month and 6 months, the patency rates of the 17 grafts were 100% regardless of the presence or absence of an omentum wrap. The healing of the grafts without omentum wrap was incomplete 6 months after implantation; granulation tissue was present in the center of the pseudointima. The grafts healed completely by the addition of an omentum wrap. Our data suggest that, with an omentum wrap, the high-porosity ePTFE graft is fully expected to show a good long-term function.

Animals↗
PubMed2000

Antithrombotic activity of NSP-513, a novel selective phosphodiesterase 3 inhibitor, on femoral arterial thrombosis induced by physical stenosis and electrical current: comparison of antithrombotic and hemodynamic effects.

NSP-513, a novel potent and selective phosphodiesterase 3 (PDE 3) inhibitor, and cilostazol, a previously developed PDE 3 inhibitor, were compared with respect to antiplatelet, antithrombotic, and hemodynamic effects. In the in vitro antiplatelet aggregation studies, NSP-513 and cilostazol inhibited collagen-induced canine platelet aggregation with median inhibitory concentration (IC50) values of 0.093 and 3.1 miccroM, respectively, and inhibited adenosine diphosphate (ADP)-induced canine platelet aggregation with IC50 values of 0.15 and 12 microM, respectively. For ADP-induced platelet aggregation, the presence of prostaglandin E1 (PGE1; 3 and 10 nM) further decreased the IC50 values for NSP-513 to 0.11 and 0.032 microM, respectively. In ex vivo antiplatelet aggregation studies, orally administered NSP-513 (0.03-1 mg/kg) and cilostazol (50 mg/kg) inhibited collagen-induced canine platelet aggregation. In an in vivo canine femoral arterial thrombosis model, intraduodenally administered NSP-513 (0.01-0.03 mg/ kg) dose-dependently prevented thrombus formation without any changes in blood pressure, heart rate, or bleeding time. In conscious dogs, NSP-513 at oral doses of > or =0.3 mg/kg produced hemodynamic changes such as decreased blood pressure and increased heart rate and LVdP/dt(max). Thus the minimal hemodynamically effective dose of NSP-513 was 0.3 mg/kg, and the hemodynamic effects of this dose were comparable to those of 50 mg/kg of cilostazol. In conclusion, these data suggest that NSP-513 has in vivo selectivity for antiplatelet and antithrombotic activities over hemodynamic activity, and that the selectivity of NSP-513 is higher than that of cilostazol in dogs.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

Arterial repair with synthetic patch by using titanium clips.

BACKGROUND: Vascular closure staple (VCS) clips made of titanium were originally developed for microvascular anastomoses. There is limited experience with their applicability to vascular reconstruction in larger vessels. This study compares VCS clips to standard sutures in arterial repair using a synthetic patch. METHODS: In an experimental study with pigs, two sequential 10-mm abdominal aortotomies were allocated randomly to synthetic patch (polytetrafluoroethylene) repair with VCS clips or continuous 6-0 polypropylene sutures. Angiographic, macroscopic, and microscopic results were assessed after 2 months. RESULTS: There were no significant differences in the patency rate, vessel diameter at the repair site, or healing indices. The mean (SD) clamp time was 8.7 (3.0) minutes for clip repair and 14.3 (7.4) minutes for suture repair (p = 0.04), and the times required for the vessel reconstruction were 5.3 (1.3) and 9.3 (3.0) minutes, respectively (p = 0.009). CONCLUSION: Patched arterial repair with VCS clips is faster than sutured reconstruction with comparable results after 2 months of follow up.

Animals↗
PubMed2000

Antiplatelet and antithrombotic effects of a novel selective phosphodiesterase 3 inhibitor, NSP-513, in mice and rats.

We investigated the effects of NSP-513, (R)-4,5-dihydro-5-methyl-6-[4-(2-propyl-3-oxo-1-cyclohexenyl)amino] phenyl-3(2H)-pyridazinone, on phosphodiesterase (PDE) isozyme activities, in vitro platelet aggregation and in vivo thrombus formation. NSP-513 selectively inhibited human platelet PDE 3 isozyme with an IC50 value of 0.039 microM. In an in vitro human platelet aggregation assay, the IC50 values (microM) of NSP-513 for platelet aggregation induced by collagen, U-46619, arachidonic acid, adenosine diphosphate (ADP), epinephrine and thrombin were 0.31, 0.25, 0.082, 0.66, 0.23 and 0.73, respectively. In a mouse pulmonary thromboembolism model, orally administered NSP-513 showed in vivo antithrombotic effects that were 320 to 470 times more potent than those of cilostazol. In a rat carotid arterial thrombosis model, intraduodenally administered NSP-513 (0.1 mg/kg), cilostazol (30 mg/kg) and aspirin (30 mg/kg) reduced thrombus formation by 75%, 66% and 48%, respectively. However, intravenously administered dipyridamole (10 mg/kg) did not significantly prevent thrombus formation. These results demonstrate that NSP-513 has the potential to prevent not only in vitro platelet aggregation but also in vivo thrombus formation and indicate that the highly selective PDE 3 inhibitory effect of NSP-513 may make this compound useful for assessing the physiological role of PDE 3.

Adenosine Diphosphate↗
PubMed2000

Apoptosis of proliferative cortical tubular epithelia in chronic progressive nephrosis of rats.

To investigate the role of apoptosis in the pathogenesis of rat chronic progressive nephrosis (CPN), the kidney of male F344/DuCrj rats, 19, 59, and 111 weeks of age, was examined histologically. In situ analysis for DNA fragmentation and proliferating cell nuclear antigen (PCNA) was performed simultaneously by TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry, respectively. CPN was seen in all the kidneys of 59-week-old (n=6) and 111-week-old rats (n=16), correlating significantly (p<0.01) with age. There were apoptotic bodies (ABs) in the single-layered epithelia of dilated tubules (SLD) and the multilayered epithelia (ML) of the cortical tubules. There were no ABs in any of the kidneys of the 19-week-old (n=5) or 59-week-old rats (n=6). Proliferative activity might have been enhanced in the single-layered and flattened epithelia, SLD, and ML of the cortical tubules in the kidneys of the 59-week-old rats (n=6) compared with that in 111-week-old rats (n=8). The correlations between the TUNEL-positive ratio and number of PCNA-positive cells, and age and the CPN grade were significant (p<0.01) exclusively in the ML. Thus, the results suggest that apoptosis occurs in the proliferative ML of rat CPN, and the pathological significance might be the removal of abnormal or excess cells.

Animals↗
PubMed2000

Concomitant abdominal aortic aneurysm repair and cholecystectomy. Combination of retroperitoneal aortic reconstruction and gassless laparoscopic cholecystectomy.

The coexistence of cholelithiasis and abdominal aortic aneurysm is not uncommon. However, cholecystectomy at the time of abdominal aortic reconstruction has generally been delayed because of the potential contamination of the graft. The case described here had concomitant cholelithiasis and abdominal aortic aneurysm, both of which were required to be treated, and was successfully treated with a combination of retroperitoneal abdominal aortic reconstruction and gasless laparoscopic cholecystectomy.

Aortic Aneurysm, Abdominal↗
PubMed2000

Biological response to expandable metallic stents implanted into the portal vein. A histomorphometric study.

BACKGROUND: This study was undertaken to investigate the biological response to an expandable metallic stent implanted in the canine portal vein with a special reference to the histomorphometric contribution of cellular and acellular elements to the intimal and medial growth. METHODS: In 11 dogs, the Gianturco Z stent was placed into the portal vein and was harvested at intervals of 4 (n=6) and 12 weeks (n=5). In 6 dogs, the normal portal vein was harvested and used as a control. The specimens were subjected to histomorphometric examination. RESULTS: Mean intimal/medial thickness and total intimal/medial area significantly increased progressively by 12 weeks. Collagen intimal/medial area also significantly increased progressively by 12 weeks, while smooth muscle intimal/medial area significantly increased at 4 weeks but did not change from 4 weeks to 12 weeks. Collagen density tended to increase at 4 weeks and significantly increased at 12 weeks, while smooth muscle density significantly decreased at 4 weeks and continued to decrease at 12 weeks. CONCLUSIONS: The total area or mean thickness of the intima and media of the stented portal vein continued to increase by 12 weeks after stent placement. This phenomenon appeared to be due to proliferation of smooth muscle cells followed by accumulation of collagen.

Animals↗
PubMed2000

Arterial thoracic outlet syndrome with embolic cerebral infarction. Report of a case.

Cerebral embolism is a very rare but recognized manifestation of arterial complications of thoracic outlet syndrome, and is associated with retrograde embolization in the cerebral arteries. We herein report a case of embolic brain infarction due to arterial thoracic outlet syndrome while discussing the etiology, diagnosis, and surgery.

Cerebral Infarction↗
PubMed1999

Effects of omental wrap on performance of small-caliber high-porosity expanded polytetrafluoroethylene grafts.

The purpose of this study was to evaluate the effects of omental wrap on the performance of small-caliber expanded polytetrafluoroethylene (ePTFE) grafts, with a special reference to transmural capillary ingrowth. High-porosity ePTFE grafts with a fibril length of 60 micrometer, an internal diameter of 4 mm, and 40 mm in length were implanted into the canine bilateral carotid arteries. The grafts on the right side were wrapped in an omental pedicle flap (omentum-wrap grafts), while those on the left were not (nonwrap grafts). The grafts were retrieved at intervals of 4 and 12 weeks. At 4 weeks, the patency rates of the omentum-wrap grafts and nonwrap grafts were almost the same (5/6 vs 6/6). At 12 weeks, patency tended to be higher in the omentum-wrap grafts than in the nonwrap grafts (3/5 vs 1/5). At 4 weeks, the thrombus-free surface score (TFS) was significantly higher in the omentum-wrap grafts than in the nonwrap grafts (44.8% vs 30.2%, P < 0.05). At 12 weeks, the TFS tended to be higher in the omentum-wrap grafts than in the nonwrap grafts (84.6% vs 62.4%). At 4 weeks, both the capillary transsectional area score (CTS) and capillary density were significantly higher in the omentum-wrap grafts than in the nonwrap grafts (CTS, 3.3% vs 1.1%, P < 0.05; capillary density, 196.0/mm2 vs 83.3/mm2, P < 0.05). At 12 weeks, both CTS and capillary density tended to be higher in the omentum-wrap grafts than in the nonwrap grafts (CTS, 1.1% vs 0%; capillary density, 69.4/mm2 vs 0/mm2). At 4 weeks, in the omentum-wrap grafts, extracellular matrices and cells in the interstices of the graft were stained with an antibody against VEGF. In conclusion, the omental wrap enhances transmural capillary ingrowth and thereby promotes endothelialization in small-caliber high-porosity ePTFE grafts. VEGF appears to play an active role in transmural capillary ingrowth enhanced by omental wrap.

Anastomosis, Surgical↗
PubMed1998

Portal vein reconstruction with conventional polytetrafluoroethylene grafts: an experimental study in dogs.

The purpose of this study was to examine the short- and long-term performance of conventional polytetrafluoroethylene (PTFE) grafts for portal vein reconstruction. The grafts were placed as a portal vein replacement in 11 mongrel dogs. At 1 month and 6 months, the grafts were then retrieved and examined for patency, while also undergoing a pathological analysis. During the observation period (at 55 days), one dog died of an unknown cause with a patent graft. The patency rates of the other 10 grafts were 83% (5/6) at 1 month and 100% (4/4) at 6 months. However, the neointima formation was incomplete even 6 months after implantation. In conclusion, although conventional PTFE grafts may be used as a synthetic alternative to autogenous vein grafts, every effort should be made to use autogenous vein grafts before considering conventional PTFE grafts.

Animals↗
PubMed1998

Gianturco stents for the venous system: a detailed pathological study.

This study was designed to examine the short-term performance of Gianturco stents placed in the venous system, in comparison with that of stents placed in the arterial system. Single-bodied modified Gianturco stents were surgically placed in six dogs (group 1), while in another six dogs, only exposure of the vessels was performed (group 2). Segments with an outer diameter 0.9 times smaller than those of the stents were targeted in the infrarenal inferior vena cava (IVC), the portal vein (PV), and the infrarenal abdominal aorta (AA). The animals were killed 4 weeks postoperatively for pathological analysis. All the segments were patent in both groups. Although the stents placed in the infrarenal IVC and PV were completely covered with neointima, those placed in the infrarenal AA were only partially covered. Furthermore, the venous stents were deeply embedded in the media, while the aortic stents remained in the intima. Medial hyperplasia occurred in the venous stents, while intimal hyperplasia occurred in the aortic stents. In conclusion, Gianturco stents placed in the IVC and PV performed better in the short term than the stents placed in the AA.

Animals↗