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Biomedical subjects

A Kurita

Publications and source records attributed to A Kurita.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of sentinel node identification with isosulfan blue in gastric cancer.

AIMS: The aim of this study was to clarify whether the metastasis of gastric cancer can be detected by identifying the sentinel lymph nodes (SNs) using only lymphatic dye. METHOD: The study was based on 101 patients clinically diagnosed with T1 and T2 gastric cancer. Isosulfan blue was intraoperatively injected within the submucosal layer around the lesion through an endoscope and blue stained nodes (BNs) were identified as SNs and harvested. Standard radical gastrectomy with D2 lymphadenectomy was performed on all patients and SNs and other nodes were evaluated. RESULTS: Out of 101 patients, 21 had lymph-node metastases. The accuracy of SN identification was 97.0% (98/101) and the metastasis detection rate was 85.7% (18/21). With improvement of the manoeuvre in the latter 84 cases, the detection rate was elevated up to 100.0% (18/18), as was the accuracy (84/84). CONCLUSION: The sentinel concept using lymphatic dye is applicable to gastric cancer, but the identification of SNs with lymphatic dye requires some practice. Furthermore, the issue of intraoperative metastasis detection remains to be resolved.

Adult↗
PubMed2006

Stage migration caused by D2 dissection with para-aortic lymphadenectomy for gastric cancer from the results of a prospective randomized controlled trial.

BACKGROUND: Extended lymphadenectomy (D2) provides accurate nodal staging of gastric cancer. The aim of this study was to clarify the degree of stage migration seen with D2 combined with para-aortic lymph node dissection for gastric cancer invading the subserosa, the serosa and adjacent structures (T2ss-4) in patients considered not to have distant metastases (M0). METHODS: Between July 1995 and April 2001, 523 patients were recruited and randomized in a prospective phase III trial comparing D2 with D2 and para-aortic nodal dissection for T2ss-4 gastric cancer without macroscopic para-aortic nodal metastases. Stage migration was evaluated by Japanese Gastric Cancer Association staging in 260 patients who underwent D2 with para-aortic dissection by analysing pathological information from the dissected lymph nodes. RESULTS: Node (N)-stage migration was observed in 1 per cent (1 of 82) of patients with N1 disease, 20 per cent (12 of 59) with N2, 43 per cent (10 of 23) with N3 and 8.8 per cent (23 of 260) of all patients. Final stage migration occurred in 9 per cent (5 of 58) of patients with stage IIIa, 19 per cent (8 of 42) with stage IIIb, 56 per cent (9 of 16) with stage IVa and 8.5 per cent (22 of 260) of all patients. Metastasis to N4 nodes was found in 4 per cent (four of 95) of tumours invading the subserosa and 17.4 per cent (19 of 109) of tumours penetrating the serosa. The overall incidence of N4 involvement was 8.8 per cent (23 of 260). CONCLUSION: Extended para-aortic lymphadenectomy for gastric cancer provides accurate nodal staging and results in stage migration, which may improve stage-specific survival regardless of overall survival benefit.

Humans↗
PubMed2005

Identification of risk factors for the development of complications following extended and superextended lymphadenectomies for gastric cancer.

BACKGROUND: Extended lymphadenectomy for gastric carcinoma has been associated with high mortality and morbidity rates in several multicentre randomized trials. METHODS: Using data from 523 patients registered for a prospective randomized trial comparing extended (D2) and superextended (D3) lymphadenectomies, risk factors for overall complications and major surgical complications (anastomotic leakage, intra-abdominal abscess and pancreatic fistula) were identified by multivariate logistic regression analysis. RESULTS: Mortality and morbidity rates were 0.8 per cent (four of 523) and 24.5 per cent (128 of 523) respectively. Pancreatectomy (relative risk 5.62 (95 per cent confidence interval (c.i.) 1.94 to 16.27)) and prolonged operating time (relative risk 2.65 (95 per cent confidence interval 1.34 to 5.23)) were the most important risk factors for overall complications. A body mass index of 25 kg/m2 or above, pancreatectomy and age greater than 65 years were significant predictors of major surgical complications. CONCLUSION: Pancreatectomy should be reserved for patients with stage T4 disease. Age and obesity should be considered when planning surgery.

Adult↗
PubMed2005

Effect of betaxolol hydrochloride on heart rate variability indices during exercise stress testing in patients with hypertension.

Betaxolol hydrochloride is a beta1-selective antagonist that produces vasodilation in patients with hypertension and ischemic heart disease. The goal of the present study was to characterize the effect of betaxolol on heart rate variability indices (HRV), a well-established prognostic marker. Symptom limited-treadmill exercise testing was performed in 17 hypertensive patients (60.9 +/- 14.8 years-old) before and immediately a 3 weeks course of betaxolol hydrochloride (5 mg daily). Frequency domain HRV (high frequency spectra, HF; 0.15-0.40 Hz: low frequency spectra, LF; 0.04-0.15 Hz) was measured during exercise treadmill testing using MemCalc software. Betaxolol hydrochloride significantly decreased the maximal systolic blood pressure and heart rate (184 +/- 29 vs. 156 +/- 26 mmHg, P < 0.01; 132 +/- 21 vs. 113 +/- 15 bpm, P < 0.01) and significantly increased HF and LF during exercise treadmill testing (HF, 32 +/- 36 vs. 56 +/- 55 men/Hz, P < 0.01; LF, 64 +/- 58 vs. 95 +/- 86 men/Hz, P < 0.01). Thus, treatment with betaxolol hydrochloride resulted in a decrease in blood pressure during exercise treadmill testing and in an increase in HRV. This suggests that this agent could have beneficial effects on long-term prognosis in patients with hypertension.

Adrenergic beta-Antagonists↗
PubMed2005

Risk factors for myocardial injury during off-pump coronary artery bypass grafting.

BACKGROUND: Although off-pump coronary artery bypass grafting (CABG) is now used worldwide for coronary revascularization, the pre- and intraoperative risk factors for myocardial injury associated with the surgical procedure remain to be elucidated. We performed a multivariate analysis to investigate factors that contribute to myocardial injury during off-pump CABG. METHODS: The study population consisted of 22 patients who underwent off-pump CABG without apparent intraoperative complications. Blood samples were obtained before surgery and at 3 and 12 hours after the last anastomosis and serum Troponin T (cTnT) levels were measured to assess myocardial injury. Patient characteristics and factors related to preoperative cardiac function and the intraoperative process were analyzed to determine their correlation with serum cTnT levels, and the Spearman's correlation coefficient (r(s)) was computed. RESULTS: Neither age, preoperative cardiac function, time required for anastomosis, the number of grafts, nor the total amount of bleeding were associated with serum cTnT levels. Serum cTnT at 3 and 12 hours after completed anastomosis correlated with the product of mean systolic blood pressure and mean heart rate (double product) during anastomosis. The r(s) values at 3 and 12 hours were 0.62 (P = .002) and 0.58 (P = .004), respectively. With respect to the serum cTnT level at 12 hours, creatinine clearance (Ccr) had a slight effect on the serum cTnT values. CONCLUSIONS: High blood pressure and an increased heart rate during anastomosis are unfavorable factors for off-pump CABG. However, strict control of the blood pressure and heart rate makes it possible to subject even patients at high-risk to off-pump CABG from the viewpoints of myocardial injury.

Aged↗
PubMed2003

A phase I study of S-1 combined with weekly cisplatin for metastatic gastric cancer in an outpatient setting.

A dose-escalation study was conducted for patients with metastatic gastric cancer to determine the recommended dose of weekly intravenous (i.v.) cisplatin combined with a fixed dose of a new oral dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine, S-1, on an outpatient basis. Secondary endpoints were to define the toxicity profile and to determine tumour responses. S-1 was fixed at a dose of 70 mg/m(2)/day and was administered for 2 weeks followed by a 1-week rest. Three dose levels of cisplatin (10, 15 and 20 mg/m(2)) were studied. Cisplatin was infused over 30 min on days 1 and 8. 20 patients were enrolled. No dose-limiting toxicities (DLTs) were recorded during the administration of cisplatin up to 20 mg/m(2), except for grade 3 diarrhoea and stomatitis in one patient at dose level 3. No grade 4 adverse events occurred. However, grade 2 gastrointestinal adverse reactions, such as nausea and anorexia, were seen in 7 of 13 patients at dose level 3 within the first two treatment cycles. This was determined to be the maximum acceptable level that would not negate the advantages observed with use of an oral drug such as S-1. An objective tumour response was seen at all dose levels, and the overall response rate in the 18 patients evaluated was 61%. A higher response rate of 78% was observed in 9 patients who had received no prior chemotherapy. Oral S-1 with weekly cisplatin is a feasible and promising combination regimen that is appropriate for an outpatient setting. A randomised phase II study comparing this combination with S-1 alone in chemo-nai;ve patients is warranted.

Adult↗
PubMed2003

Flow-mediated dilation in brachial artery in the second half of pregnancy and prediction of pre-eclampsia.

Endothelial injury and increased vascular reactivity are involved in the pathogenesis of pre-eclampsia (pregnancy-induced hypertension). To investigate whether flow-mediated dilation (endothelium-dependent dilation) and the reactive hyperemic response can predict pre-eclampsia, we prospectively measured flow-mediated dilation and the Doppler flow velocity pattern (V, cm/s) in the brachial artery using high-resolution ultrasound in 43 pregnant women (32+/-5 years old) in the second half of their pregnancy, and compared the findings with traditional risk factors. Regarding the Doppler flow velocity pattern, the pulsatility index (PI)=(systolic V-diastolic V)/mean V and resistance index (RI)=(systolic V-diastolic V)/systolic V were calculated. For the flow-mediated dilation, the per cent diameter changes were determined based on those from baseline to hyperemic conditions. Nine women suffered from pre-eclampsia and 34 women remained normotensive. Only flow-mediated dilation was found to be significantly lower in the subsequently developed pre-eclampsia patients (1.6+/-1.0% in subsequently developed pre-eclampsia patients vs 11.0+/-4.5% in normotensive patients, P<0.05). Neither the other traditional factors nor the Doppler flow velocity pattern were significantly different between the subsequently developed pre-eclampsia and normotensive patients. If a normal cutoff value of 3.0% obtained from age-matched 14 nonpregnant women (32+/-7 years old) in our laboratory was used, the positive predictive value of flow-mediated dilation (<3.0%) for subsequent pre-eclampsia is 90% and the negative predictive value is 100%. In conclusion, flow-mediated dilation in brachial artery can be a simple and noninvasive modality to predict pre-eclampsia.

Adult↗
PubMed2002

Periodate-treated, non-anticoagulant heparin-carrying polystyrene (NAC-HCPS) affects angiogenesis and inhibits subcutaneous induced tumour growth and metastasis to the lung.

Periodate-treated, non-anticoagulant heparin-carrying polystyrene consists of about ten periodate-oxidized, alkaline-degraded low molecular weight-heparin chains linked to a polystyrene core and has a markedly lower anti-coagulant activity than heparin. In this study, we evaluated the effect of non-anticoagulant heparin-carrying polystyrene on tumour growth and metastasis. Non-anticoagulant heparin-carrying polystyrene has a higher activity to inhibit vascular endothelial growth factor-165-, fibroblast growth factor-2- or hepatocyte growth factor-induced human microvascular endothelial cell growth than heparin, ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin, which is probably due to the heparin-clustering effect of non-anticoagulant heparin-carrying polystyrene. Non-anticoagulant heparin-carrying polystyrene inhibited human microvascular endothelial cell, B16 melanoma and Lewis lung cancer cell adhesion to Matrigel-coated plates. Non-anticoagulant heparin-carrying polystyrene also showed strong inhibitory activities in the tubular formation of endothelial cells on Matrigel and B16-melanoma and Lewis lung cancer cell invasion in a Matrigel-coated chamber assay. In vivo studies showed that growth of subcutaneous induced tumours and lung metastasis of B16-melanoma and Lewis lung cancer cells were more effectively inhibited by non-anticoagulant heparin-carrying polystyrene than ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin. Furthermore, non-anticoagulant heparin-carrying polystyrene markedly reduced the number of CD34-positive vessels in subcutaneous Lewis lung cancer tumours, indicating a strong inhibition of angiogenesis. These results suggest that non-anticoagulant heparin-carrying polystyrene has an inhibitory activity on angiogenesis and tumour invasion and may be very useful in cancer therapy.

Angiogenesis Inhibitors↗
PubMed2001

Heparin-carrying polystyrene (HCPS)-bound collagen substratum to immobilize heparin-binding growth factors and to enhance cellular growth.

Heparin-carrying polystyrene (HCPS), consisting of low molecular weight heparin chains linked to a synthetic polystyrene core, is able to attach to polymeric surfaces. In this study, HCPS has efficiently bound to collagen-coated micro-plates and collagen membranes thereby retaining the binding of heparin-binding growth factors, such as vascular endothelial growth factor (VEGF)(165) or fibroblast growth factor (FGF)-2. Both human skin fibroblast cells and human umbilical vein endothelial cells have shown a good adherence to both collagen- and HCPS-bound collagen substrata. The growth rate of the fibroblast cells on the HCPS-bound collagen substratum in the presence of low concentrations of FGF-2 is higher than on a collagen surface. The fibroblast cells grow at a significantly higher rate on the HCPS-bound collagen substratum retained with FGF-2. Similarly, the growth rate of the endothelial cells on the HCPS-bound collagen substrata in the presence of low concentrations of either FGF-2 or VEGF(165) is higher than on collagen. The endothelial cells also grow at a significantly higher rate on the HCPS-bound collagen substratum retained with either FGF-2 or VEGF(165). These results indicate that HCPS-bound collagen substrata with various bioactive heparin-binding molecules may provide novel biomaterials controlling cellular activities such as growth and differentiation.

Biocompatible Materials↗
PubMed2001

Impaired endothelium-dependent vasodilation in the brachial artery in variant angina pectoris and the effect of intravenous administration of vitamin C.

UNLABELLED: Endothelial dysfunction in the coronary artery contributes to the pathogenesis of variant angina, and endothelial dysfunction in variant angina may be associated with increased oxidant stress in the systemic arteries. We investigated whether endothelial dysfunction exists in the peripheral artery in patients with variant angina, and also examined the effect of vitamin C, an antioxidant, on endothelium-dependent vasodilation. Using high-resolution ultrasound, both the flow-mediated vasodilation (FMD, endothelium-dependent vasodilation) and sublingual nitroglycerin-induced vasodilation (NTG-D, endothelium-independent vasodilation) in the brachial artery were measured in 28 patients with variant angina and 24 control subjects who had normal coronary arteries. FMD was significantly impaired in patients with variant angina compared with control subjects (1.8 +/- 2.2% vs 6.4 +/- 4.9%, p <0.001). FMD and NTG-D before and after intravenous administration of either vitamin C or placebo were measured in 17 patients with variant angina. FMD significantly improved after the administration of vitamin C (from 2.2 +/- 2.4% to 4.5 +/- 1.6%, p <0.01), but not after administration of the placebo (from 2.0 +/- 2.6% to 1.7 +/- 1.9%). The improved FMD due to vitamin C in patients with variant angina, however, was not significantly different from that in the control subjects. NTG-D was not significantly different between patients with variant angina and control subjects (14.0 +/- 7.8% vs 13.6 +/- 5.0%) and it was also not affected by vitamin C. IN CONCLUSION: (1) FMD in the brachial artery is impaired in patients with variant angina, and (2) the acute administration of the antioxidant, vitamin C, was observed to reverse this endothelial dysfunction. These findings support the theory that the systemic inactivation of nitric oxide due to oxidative stress might exist in patients with variant angina.

Angina Pectoris, Variant↗
PubMed2001

Angioplasty decreases prolonged QT dispersion in patients with angina pectoris but not in patients with prior myocardial infarction.

BACKGROUND AND HYPOTHESIS: Prolonged QT dispersion (QTd) is shortened by successful percutaneous transluminal coronary angioplasty (PTCA) in patients with ischemic heart disease. Particularly, QTd plays an important role in the prognostication in patients with prior myocardial infarction (MI). However, whether the effect of PTCA on QTd differs in patients with and without prior MI is not clear, and this study sought to clarify this question. METHODS: In 41 consecutive patients with ischemic heart disease, we measured QTd from a routine 12-lead electrocardiogram taken at 72 h before and after successful PTCA. Patients were divided into two groups based on the presence or absence of prior MI: Group 1 consisted of 24 patients with angina (61 +/- 11 years old) without prior MI and Group 2 was comprised of 17 patients (69 +/- 10 years old) with prior MI. QTd was calculated as the difference between the maximum and minimum QT and QT corrected for heart rate (QTc), using Bazett's formula for calculating QTcd. All measurements were obtained manually and blindly. RESULTS: In Group 1, 15 of 24 patients (63%) demonstrated multivessel disease and 16 of 24 (67%) patients had high QTd > 60 ms. Percutaneous transluminal coronary angioplasty decreased QTd and QTcd in Group 1 (QTd, from 83 +/- 35 to 57 +/- 19 ms, p < 0.05 ; QTcd, from 89 +/- 37 to 63 +/- 33 ms, p < 0.05), whereas no changes were observed in Group 2 (QTd, from 73 +/- 25 to 69 +/- 22 ms, NS; QTcd, from 80 +/- 30 to 79 +/- 28 ms, NS). QTd is more sensitive to decrease by successful PTCA in patients with angina than in patients with prior MI. CONCLUSIONS: The effect of successful PTCA on inhomogeneity of ventricular repolarization reflected by QTd in patients with prior MI is different from that in patients without prior MI.

Aged↗
PubMed2001

Endothelial dysfunction and decreased exercise tolerance in interferon-alpha therapy in chronic hepatitis C: relation between exercise hyperemia and endothelial function.

BACKGROUND: We previously reported that reversible endothelial dysfunction is caused by interferon-alpha therapy (IFN) in patients with chronic hepatitis C. In experimental studies, limb blood flow during exercise is reported to be dependent on endothelium-derived nitric oxide. HYPOTHESIS: The purpose of this study was to confirm the effect of IFN on endothelial function and to investigate whether exercise hyperemia is dependent on endothelial function in humans. METHODS: We performed symptom-limited exercise treadmill testing and measured flow-mediated vasodilation (FMD, endothelium-dependent vasodilation) and sublingual glyceryl-trinitrate-induced dilation (GTN-D, 0.3 mg, endothelium-independent vasodilation) in the brachial artery by using high-resolution ultrasound in 10 patients with chronic active hepatitis C (age 53 +/- 11 years, 2 men, 8 women) before and immediately after administration of recombinant interferon 2b (10 million U/day) for 4 weeks. RESULTS: There were no significant abnormal findings in any patients in routine studies of 24-h ambulatory electrocardiogram monitoring, two-dimensional echocardiography, and exercise treadmill testing both before and after treatment. Leg fatigue and exhaustion were the reasons for termination of exercise treadmill testing in each patient. Pressure rate product was calculated at rest and peak exercise. Interferon-alpha therapy significantly (p<0.05) decreased FMD (6.8 +/- 3.1 vs. 1.9 +/- 2.6%), exercise treadmill testing tolerance time (437 +/- 89 vs. 395 +/- 62 s) and peak pressure rate product (283 +/- 41 vs. 241 +/- 47 mmHg x beats/min x 10(-2)), but not GTN-D (13.4 +/- 5.4 vs. 17.0 +/- 5.5%). The change of FMD due to IFN significantly and highly correlated with exercise treadmill testing tolerance time (r = 0.86, p<0.001), but not with change of peak pressure rate product, suggesting that FMD is more closely related to the condition of the peripheral circulation than is cardiac performance. CONCLUSION: These results suggest that IFN in patients with chronic hepatitis C impairs endothelial function and exercise tolerance, and that endothelial function might be at least partly involved in exercise hyperemia in humans.

Adult↗
PubMed2001

Nanosecond, high-intensity pulsed laser ablation of myocardium tissue at the ultraviolet, visible, and near-infrared wavelengths: in-vitro study.

BACKGROUND AND OBJECTIVE: A large number of clinical trials of transmyocardial laser revascularization (TMLR) have been conducted to treat severe ischemic heart diseases. A variety of laser sources have been used or tested for this treatment, however, no comprehensive study has been performed to reveal the mechanism and the optimum laser irradiation condition for the myocardium tissue ablation. There have been reported limited experimental data of the high-intensity pulsed laser ablation of myocardium tissues. STUDY DESIGN/MATERIALS AND METHODS: A 1064-nm Q-switched Nd:YAG laser and its 2nd (532 nm), 3rd (355 nm), and 4th (266 nm) harmonics were used for ablation experiments. At each wavelength, 25 laser pulses irradiated the porcine myocardium tissue samples at a constant laser intensity (peak laser power divided by laser spot area) of approximately 2 GW/cm(2) and the ablation depths were measured. During ablation, laser-induced optical and acoustic emissions were measured to investigate the ablation mechanism at each laser wavelength. For the ablated tissues, histological observation was made with a polarization optical microscope. RESULTS: It was shown that the ablation efficiency did not directly depend on the linear absorption coefficient of the tissue; the ablation depth was maximized at 355 and 1064 nm, and minimized at 532 nm. Strong laser-induced optical and acoustic emissions were observed for the 266- and 1064-nm laser irradiations. The histology showed that thermal denaturation of the tissue near the ablation walls decreased with decreasing wavelength for 266, 355, and 532 nm, but it was limited for 1064 nm. CONCLUSION: At the laser intensity of approximately 2 GW/cm(2), ablation characteristics were drastically changed for the different laser wavelengths. The results indicated that for 266, 355, and 532 nm, the tissue removal was achieved mainly through a photothermal process, but for 266 nm the intense laser-induced plasma formation would result in a reduced laser energy coupling to the tissue. For 1064 nm, a photodisruption was most probable as a dominant tissue removal process. Because of the high ablation rate and limited thermal denaturation, the 355- and 1064-nm lasers could be potential laser sources for TMLR, although further investigation is needed to discuss the clinical issues.

Angioplasty, Laser↗
PubMed2001

Different mechanisms of isoproterenol-induced and nitroglycerin-induced syncope during head-up tilt in patients with unexplained syncope: important role of epinephrine in nitroglycerin-induced syncope.

INTRODUCTION: A reduction in left ventricular volume and an increase in epinephrine levels have been reported in tilt-induced neurally mediated syncope. To compare the mechanisms of isoproterenol-induced and nitroglycerin-induced syncope during head-up tilt and to investigate the role of catecholamines, the temporal changes in plasma levels of norepinephrine and epinephrine and in left ventricular volume were measured. METHODS AND RESULTS: The first study population consisted of 90 patients with syncope of unknown etiology and 12 control subjects. The second study population consisted of 43 patients with unexplained syncope. In the first study, head-up tilt (80 degree angle) was conducted for 40 minutes, and norepinephrine and epinephrine levels were measured. In the second study, all patients were randomly allocated to either isoproterenol test (20 patients) or nitroglycerin test (23 patients) for 20-minute head-up tilt. Isoproterenol infusion was given at a rate of 1 to 3 microg/min. Intravenous infusion of nitroglycerin was started at 250 microg/hour with increasing dosages up to 1,500 microg/hour. Norepinephrine and epinephrine were measured in peripheral venous blood. Left ventricular volumes were measured by echocardiography with patients in the supine position and during head-up tilt every 1 minute. End-diastolic volume and end-systolic volume were calculated. In the first study, 61 patients demonstrated a positive response and 29 patients demonstrated a negative response. Plasma norepinephrine changes during head-up tilt were not significantly different, whereas epinephrine levels were significantly higher in the positive patients than in the negative and control subjects (148 +/- 118 pg/mL vs 66 +/- 31 pg/mL and 55 +/- 27 pg/mL). Thirteen of the 20 patients given isoproterenol and 15 of the 23 patients given nitroglycerin showed a positive head-up tilt (65.0% vs 65.2%; P = NS). During isoproterenol and nitroglycerin infusion head-up tilt, epinephrine in the positive group determined by the nitroglycerin test was significantly higher than that in the other three groups (103 +/- 38 pg/mL vs 60 +/- 33 pg/mL, 31 +/- 21 pg/mL, and 50 +/- 52 pg/mL). In contrast, end-systolic volume was significantly smaller in the positive group than in the other three groups based on findings of the isoproterenol test. CONCLUSION: The findings suggest that nitroglycerin triggers head-up tilt-induced syncope by increasing epinephrine levels, whereas isoproterenol induces syncope by decreasing left ventricular volume.

Adolescent↗
PubMed2001

Experimental evaluation of photocrosslinkable chitosan as a biologic adhesive with surgical applications.

BACKGROUND: In various surgical cases, effective tissue adhesives are required for both hemostasis (eg, intraoperative bleeding) and air sealing (eg, thoracic surgery). We have designed a chitosan molecule (Az-CH-LA) that can be photocrosslinked by ultraviolet (UV) light irradiation, thereby forming a hydrogel. The purpose of this work was to evaluate the effectiveness and safety of the photocrosslinkable chitosan hydrogel as an adhesive with surgical applications. METHODS: The sealing ability of the chitosan hydrogel, determined as a bursting pressure, was assessed with removed thoracic aorta, trachea, and lung of farm pigs and in a rabbit model. The carotid artery and lung of rabbits were punctured with a needle, and the chitosan hydrogel was applied to, respectively, stop the bleeding and the air leakage. In vivo chitosan degradability and biologic responses were histologically assessed in animal models. RESULTS: The bursting pressure of chitosan hydrogel (30 mg/mL) and fibrin glue, respectively, was 225 +/- 25 mm Hg (mean +/- SD) and 80 +/- 20 mm Hg in the thoracic aorta; 77 +/- 29 mm Hg and 48 +/- 21 mm Hg in the trachea; and in the lung, 51 +/- 11 mm Hg (chitosan hydrogel), 62 +/- 4 mm Hg (fibrin glue, rubbing method), and 12 +/- 2 mm Hg (fibrin glue, layer method). The sealing ability of the chitosan hydrogel was stronger than that of fibrin glue. All rabbits with a carotid artery (n = 8) or lung (n = 8) that was punctured with a needle and then sealed with chitosan hydrogel survived the 1-month observation period without any bleeding or air leakage from the puncture sites. Histologic examinations demonstrated that 30 days after application, a fraction of the chitosan hydrogel was phagocytosed by macrophages, had partially degraded, and had induced the formation of fibrous tissues around the hydrogel. CONCLUSIONS: A newly developed photocrosslinkable chitosan has demonstrated strong sealing ability and a great potential for use as an adhesive in surgical operations.

Animals↗
PubMed2001

Identification, cloning, and initial characterization of a novel mouse testicular germ cell-specific antigen.

A monoclonal antibody, designated TES101, was raised by immunizing BALB/c mice with an allogenic mouse testicular homogenate followed by immunohistochemical selection as the initial screening method. By searching the expressed sequence tag (EST) database with the N-terminal amino acid sequence of TES101 reactive protein, we found that the predicted amino acid sequence encoded by a mouse testicular EST clone matched the TES101 protein sequence. Sequence analysis of the clone revealed no homologous molecule in the DNA/protein database. Based on data obtained from N-terminal amino acid analysis of the TES101 protein, the derived amino acid sequence contained a signal peptide region of 25 amino acids and a mature protein region of 225 amino acids, which translated into a protein with a molecular weight of 24 093. Northern blot analysis showed that mRNA of the TES101 protein was found in testis but not in any other mouse tissues examined. Western blot analysis revealed that TES101 reacted with a 38-kDa band on SDS-PAGE under nonreducing conditions, and this reactivity was abrogated under reducing conditions. Immunoelectron microscopic studies demonstrated that the molecule was predominantly located on the plasma membrane of spermatocytes and spermatids but not in Sertoli cells or interstitial cells, including Leydig cells. Thus, the TES101 protein is a novel molecule present primarily on the surface of developing male germ cells. TES101 protein may play a role in the processes underlying male germ cell formation.

Amino Acid Sequence↗
PubMed2001

Determining the temperature distribution of a model vessel wall under pulsed laser irradiation: an experimental attempt to measure fibrous cap thickness and detect temperature elevation in atherosclerotic lesions.

In order to measure the temperature of atherosclerotic plaques, we developed a method to determine the temperature distribution of vessel walls using a three-layer phantom agar model. Under pulsed-laser irradiation, the thickness of upper layer corresponding to fibrous cap overlying the middle layer corresponding to atherosclerotic lesion could be calculated. The temperature was calculated from measured temperature changes under pulsed-laser irradiation.

Aorta↗