Spontaneous Celiac and Splenic Artery Dissection

Dissection o f t he splanchnic artery u nrelated to an aortic lesion is extremely rare. We describe a patient with dissection of the celiac and splenic arteries causing splenic circulatory impairment. A 55-year-old Japanese man was referred to our hospital for left back pain that suddenly occurred 3 days previously and spread to the left flank. He had complicated sleep apnea syndrome well controlled with continuous positive airway pressure, and had been prophylactically taking aspirin (100 mg/day) because of asymptomatic cerebral lacunar infarcts. Contrast-enhanced computed tomography (CT) in the arterial phase revealed dissection from the celiac root extending to the entire splenic artery, the caliber of which was irregularly narrowed, causing malperfusion in the spleen. Because of hemodynamic stability and lack of impending sequelae, the patient was carefully observed with rest, strict blood pressure control, and aspirin administration. One month later, CT revealed restoration of the caliber of the dissected arteries and regression of the organizing false lumen, which confirmed the patient’s recovery. Despite the extreme rarity or nonspecific symptoms, splanchnic artery dissection should be considered a potentially life-threatening emergency. This case supports the possible benefit of starting antithrombotic treatment early to prevent thrombotic sequelae such as organ infarction and aneurysmal formation

99mTc-sestamibi retention characteristics during pharmacologic hyperemia in human myocardium: Comparison with coronary flow reserve measured by Doppler flowire

金沢大学大学院医学系研究科The aim of the study was to investigate the increase in myocardial 99mTc-methoxyisobutylisonitrile (sestamibi) retention in humans during pharmacologic vasodilation. Methods: For calculation of the increase in 99mTc-sestamibi retention during hyperemia, baseline and adenosine triphosphate (ATP)-induced hyperemic stress sestamibi studies were performed using a same-day rest-stress protocol. On the injection of sestamibi, left ventricular dynamic data were obtained for 90 s. The increase in sestamibi retention from baseline to hyperemia was calculated by the formula Cmh(t) ∫01 Cbb(τ)dτ/Cmb(t) ∫01 Cbh(τ)dτ, where Cmh(t) and Cmb(t) are myocardial counts on the tomographic image, and Cbb(τ) and Cbh(τ) are the left ventricular blood-pool counts during the first transit of sestamibi at baseline and during hyperemia, respectively. Coronary flow increase during intravenous ATP stress was measured using intracoronary Doppler flow guide wire and compared with the scintigraphic results of 28 measurements in 22 patients. Results: Sestamibi retention increased as coronary flow velocity increased but plateaued at >2.5-3 times baseline flow velocity. The relationship between the increase in sestamibi retention (Y) and the increase in flow (X) is expressed as follows: Y = 0.44 + 0.60X - 0.068X2 (r = 0.82). Conclusion: In humans, the increase in 99mTc-sestamibi myocardial retention underestimates coronary flow reserve, particularly at high flow rates. Knowledge of these tracer retention characteristics will contribute to a more comprehensive understanding of the manner and interpretation of stress sestamibi imaging

肺嚢胞例における133Ⅹe洗い出しに及ぼす咳込み負荷の効果

金沢大学大学院医学系研究

精索静脈瘤の核医学的診断について

金沢大学大学院医学系研究

腎シンチグラフィ斜位像の有効性に関する検討-特に限局性病巣検出能に関して-

金沢大学大学院医学系研究

Methylxanthine sensitization of human colon cancer cells to 186Re-labeled monoclonal antibody

金沢大学大学院医学系研究科Tumor cells lacking the functional p53 suppressor gene may arrest at the G2 phase of the cell cycle after exposure to ionizing radiation, resulting in increased radioresistance. Methylxanthines (MTXs), such as pentoxifylline (PTX) or caffeine (CAF), can inhibit the G2-phase checkpoint arrest of damaged cells and thus radiosensitize them. However, the effect of MTX in cells irradiated with low-dose-rate β-emission is not well understood. Methods: A clonogenic assay was performed with LS180 human colon cancer cells lacking the functional p53 suppressor gene. Cells were irradiated with increasing concentrations of 186Re-mercaptoacetyltriglycine (186Re-MAG3)-labeled A7 monoclonal antibody against colorectal cancer (0-925 kBq/mL) at 37°C in 5% CO2 for 24 h in the presence or absence of PTX (0-2 mmol/L) or CAF (0-5 mmol/L). The enhancement ratio (ER) with MTX was calculated as a ratio of 50% cell-killing concentration of 186Re-MAG3-A7 in control cells to that in cells treated with PTX or CAF. The cell cycle distribution was analyzed with a flow cytometer. Results: The concentration of 50% cell kill was 474 kBq/mL 186Re-MAG3-A7. Both PTX and CAF dose dependently enhanced the cytotoxicity of 186Re-MAG3-A7: ERs of 0.5 mmol/L PTX, 2 mmol/L PTX, 1 mmol/L CAF, and 5 mmol/L CAF were 1.50, 2.18, 1.54, and 2.63, respectively. Flow cytometry showed that the percentage nonirradiated cells in the G2/M phase of the cell cycle was 11.3% ± 1.66%. On the other hand, cells exposed to 186Re-MAG3-A7 accumulated in the G2/M phase of the cell cycle (40.2% ± 1.46%), which was inhibited by the presence of 1 mmol/L PTX (19.8% ± 8.12%) or 2 mmol/L CAF (26.9% ± 6.21%). Conclusion: Cellular modulation of the cell cycle with PTX and CAF radiosensitized LS180 colon cancer cells exposed to 186Re radiation

Electrocardiographic gated 99mTc-MIBI SPECT for functional assessment of patients after coronary artery bypass surgery: Comparison of wall thickening and wall motion analysis

金沢大学大学院医学系研究科Abnormal septal motion after coronary artery bypass graft surgery (CABG) is a common finding. This study was undertaken to investigate the change in various global and regional ventricular function parameters measured by gated myocardial perfusion SPECT after surgery and to determine which quantitative parameter of WT and WM is more appropriate for the evaluation of regional cardiac function, especially in the septum of patients with CABG. Methods: Before and 3 to 5 wk after CABG (all patients underwent at least 1 bypass grafting to the left anterior descending coronary artery), 35 patients (28 men, 7 women) underwent gated SPECT using 99mTc-methoxyisobutylisonitrile. Quantitative global and regional ventricular functional analysis was performed using quantitative gated SPECT software. Results: Global ejection fraction did not change (59.3% ± 16.0% to 60.5% ± 14.5%, P = 0.24). However, end-diastolic and end-systolic volumes lessened significantly after CABG (81.4 ± 37.3 mL to 68.9 ± 28.9 mL, P < 0.0001, and 38.1 ± 33.1 mL to 30.4 ± 23.0 mL, P < 0.005, respectively). As global function parameters, the changes in both total WM (r = 0.88) and WT (r = 0.86) correlated well with the change in ejection fraction after surgery. Segmental analysis showed a significant postoperative increase in relative tracer uptake in the anterior, anteroseptal, inferoseptal, and inferior walls and in the apex. Segmental wall motion (WM) deteriorated in the anteroseptal, inferoseptal, and mid anterior walls. On the other hand, anterolateral, inferolateral, and inferior WM increased. As a whole, these WM changes showed a reduction in septal motion associated with a concomitant increase in lateral motion after surgery. Segmental wall thickening, however, did not decrease in septal areas and did not increase in the lateral wall and correlated with percentage tracer uptake (r = 0.69) better than WM did (r = 0.30) after CABG. Conclusion: In patients with CABG, postoperative WM analysis by gated SPECT underestimated septal motion and overestimated lateral motion because of exaggerated systolic anteromedial cardiac translation. Therefore, wall thickening analysis would be recommended for the evaluation of postoperative cardiac functio

Cooperative effect of radioimmunotherapy and antiangiogenic therapy with thalidomide in human cancer xenografts

金沢大学大学院医学系研究科Antiangiogenic therapy may prolong the dormancy of cancer lesions. Moreover, radioimmunotherapy (RIT) may eradicate this population of cells. This study dealt with determining the benefits associated with the combined usefulness of these 2 therapies with respect to inhibition of tumor growth. Methods: Antiangiogenic therapy using oral thalidomide (daily dose, 200 mg/kg) and RIT involving a single intravenous injection (4.63 MBq 131I-A7, an IgG1 murine monoclonal antibody) were conducted in mice bearing LS180 human colon cancer xenografts. RIT with an irrelevant IgG1, HPMS-1, was also performed as a control. Antiangiogenesis of thalidomide was investigated by immunohistochemical analysis of tumor sections. Results: Antiangiogenic therapy and RIT with 131I-A7 significantly suppressed the growth of xenografts. This combination produced more efficient tumor growth inhibition than did the monotherapy (P < 0.005). RIT using 131I-HPMS-1 was far less effective than 131I-A7, even when combined with thalidomide administration. Immunohistochemistry revealed a decrease in the microvessel number within tumors treated with thalidomide (P < 0.0001). Combined therapy further reduced the microvessel number (P < 0.01 vs. thalidomide monotherapy), Conclusion: The combination of RIT and thalidomide antiangiogenic therapy produces a better response of tumors than does monotherapy. Acting in concert, antiangiogenic therapy may prolong the dormancy of cancer lesions and RIT may eradicate this population of cells

Intraperitoneal radioimmunotherapy in treating peritoneal carcinomatosis of colon cancer in mice compared with systemic radioimmunotherapy

医薬保健研究域医学系Peritoneal spread is one of major causes of mortality in colorectal cancer patients. In the current investigation, the efficacy of radio-immunotherapy (RIT) with i.p. administration of an anti-colorectal cancer IgG1, 131 I-A7, was compared to that with i.v. administration in BALB/c female mice bearing peritoneal nodules of LS180 human colon cancer cells, at the same toxicity level. Distribution of either i.p. or i.v. administered 131 I-A7 and i.p. administered irrelevant 131 I-HPMS-1 was assessed. Based on the results of toxicity determination at increments of 2 MBq and estimated dosimetry, an i.p. dose of 11 MBq and an i.v. dose of 9 MBq were chosen for treatment. Mice were monitored for long-term survival: untreated mice (n=11), mice undergoing i.p. RIT with 131 I-A7 (n=11), mice undergoing i.v. RIT with 131 I-A7 (n=11) and mice undergoing non-specific i.p. RIT with 131 I-HPMS-1 (n=5). Intraperitoneal injection of 131 I-A7 produced faster and greater tumor accumulation than i.v. injection: 34.2±16.5% of the injected dose per g (% ID/ g) and 11.1±3.6% ID/g at 2 h, respectively (P<0.0001). Consequently, cumulative radioactivity in tumors was 1.73-fold higher with i.p. injection. 131 I-HPMS-1 did not show specific accumulation. Non-specific RIT with 131 I-HPMS-1 (mean survival, 26.0±2.5 days) did not affect the survival as compared to no treatment (26.7±1.9 days). Intravenous RIT with 131 I-A7 prolonged the survival of mice to 32.8±1.8 days (P<0.01). Intraperitoneal RIT with 131 I-A7 improved the survival more significantly and attained cure in 2 of 11 mice (P<0.05 vs. i.v. RIT). In conclusion, i.p. RIT is more beneficial in treating peritoneal carcinomatosis of colon cancer than i.v. RIT in a murine model

肝硬変例における呼吸同期肝イメージングおよびフーリエ解析による肝運動性評価の試み

金沢大学大学院医学系研究