ACTIVITY CONCENTRATIONS OF RADIOCAESIUM, 90SR AND 129I IN AGRICULTURAL CROPS COLLECTED FROM FUKUSHIMA AND REFERENCE AREAS IN JAPAN, AND INTERNAL RADIATION DOSES

Significant quantities of radionuclides were released into the environment due to the 2011 TEPCO's FDNPS accident. Radiocaesium is the most important radionuclide for assessment of radiation dose, and small amounts of 90Sr and very long-lived radionuclide of 129I were also released into the environment. Spinach, potato and brown rice were collected from Fukushima, neighboring prefectures and reference areas of negligible deposition in 2018 and 2019. The activity concentration of 137Cs in crops in Hamadori (coastal side) was relatively higher than other areas. The activity concentration of 90Sr in the crops showed a similar range among four areas in Fukushima, and they were similar level of those collected throughout Japan. The activity concentration of 129I in the crops collected from Hamadori was higher than other Fukushima areas. However, the activity ratio of 129I/137Cs was lower by five to seven orders of magnitude. Internal radiation doses of radiocaesium for adult males from ingestion of local crops collected from Hamadori were 0.0046 mSv, and that of 129I were 0.00000045 mSv in 2019.

Comprehensive Surveillance of Virus Infection among Captive African Pygmy Hedgehogs in Japan

African pygmy hedgehogs (Atelerix albiventris) are popular exotic pets in Japan, and their breeding numbers have recently increased. Although various diseases have been reported in hedgehogs, including skin, respiratory, neurological, and neoplastic diseases, most of the causes remain unidentified. In this study, we investigated herpesvirus, adenovirus, and coronavirus infections among 150 African pygmy hedgehogs in Japan and evaluated the correlations between virus infection and diseases. A novel herpesvirus named Atelerix albiventris herpesvirus 1 (AAHeV), and African pygmy hedgehog adenovirus 1 (AhAdV-1) were detected in 14 and 3 oral swab samples, respectively. AAHeV infection may be related to neurological clinical signs. Interestingly, no hedgehog with a neoplastic disorder tested positive for AAHeV. Further research is required to determine the pathogenicity and prevalence of the detected viruses.

Development of In Vitro Endothelialised Stents - Review

Endovascular treatment is prevalent as a primary treatment for coronary and peripheral arterial diseases. Although the introduction of drug-eluting stents (DES) dramatically reduced the risk of in-stent restenosis, stent thrombosis persists as an issue. Notwithstanding improvements in newer generation DES, they are yet to address the urgent clinical need to abolish the late stent complications that result from in-stent restenosis and are associated with late thrombus formation. These often lead to acute coronary syndromes with high mortality in coronary artery disease and acute limb ischemia with a high risk of limb amputation in peripheral arterial disease. Recently, a significant amount of research has focused on alternative solutions to improve stent biocompatibility by using tissue engineering. There are two types of tissue engineering endothelialisation methods: in vitro and in vivo. To date, commercially available in vivo endothelialised stents have failed to demonstrate antithrombotic or anti-stenosis efficacy in clinical trials. In contrast, the in vitro endothelialisation methods exhibit the advantage of monitoring cell type and growth prior to implantation, enabling better quality control. The present review discusses tissue-engineered candidate stents constructed by distinct in vitro endothelialisation approaches, with a particular focus on fabrication processes, including cell source selection, stent material composition, stent surface modifications, efficacy and safety evidence from in vitro and in vivo studies, and future directions.

Radiocaesium in the environment of Fukushima

It has been 10 years since the accident at Fukushima Daiichi nuclear power plant in 2011. Large quantities of ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs were released into the environment, and 80% of ¹³⁷Cs still remains. In addition to the decrease by attenuation, the transfer of ¹³⁷Cs to plants, animals, and humans is decreasing due to movement and changing fractions with elapsed time. The activity concentration of ¹³⁷Cs in the atmosphere has decreased drastically, and the internal radiation dose due to inhalation is negligible. The activity concentration of ¹³⁷Cs in agricultural plants is decreasing due to decontamination of soil, application of potassium, and lower levels in irrigation water. The activity concentration of ¹³⁷Cs in wild animals is decreasing, and shows seasonal variation in wild boars. The activity concentration of ¹³⁷Cs in offshore seawater has decreased to 0.01 Bq l^-1. Therefore, the radiation dose is <1 mSv of the additional radiation dose.

Stimulatory effect of insulin on H+-ATPase in the proximal tubule via the Akt/mTORC2 pathway

Purpose

Acid-base transport in renal proximal tubules (PTs) is mainly sodium-dependent and conducted in coordination by the apical Na+/H+ exchanger (NHE3), vacuolar H+-adenosine triphosphatase (V-ATPase), and the basolateral Na+/HCO3- cotransporter. V-ATPase on PTs is well-known to play an important role in proton excretion. Recently we reported a stimulatory effect of insulin on these transporters. However, it is unclear whether insulin is involved in acid-base balance in PTs. Thus, we assessed the role of insulin in acid-base balance in PTs.

Methods

V-ATPase activity was evaluated using freshly isolated PTs obtained from mice, and specific inhibitors were then used to assess the signaling pathways involved in the observed effects.

Results

V-ATPase activity in PTs was markedly enhanced by insulin, and its activation was completely inhibited by bafilomycin (a V-ATPase-specific inhibitor), Akt inhibitor VIII, and PP242 (an mTORC1/2 inhibitor), but not by rapamycin (an mTORC1 inhibitor). V-ATPase activity was stimulated by 1 nm insulin by approximately 20% above baseline, which was completely suppressed by Akt1/2 inhibitor VIII. PP242 completely suppressed the insulin-mediated V-ATPase stimulation in mouse PTs, whereas rapamycin failed to influence the effect of insulin. Insulin-induced Akt phosphorylation in the mouse renal cortex was completely suppressed by Akt1/2 inhibitor VIII and PP242, but not by rapamycin.

Conclusion

Our results indicate that stimulation of V-ATPase activity by insulin in PTs is mediated via the Akt2/mTORC2 pathway. These results reveal the mechanism underlying the complex signaling in PT acid-base balance, providing treatment targets for renal disease.

SPECIATION OF IODINE IN SOIL SOLUTION IN FOREST AND GRASSLAND SOILS IN ROKKASHO, JAPAN

The behaviour of I in soil depends on its chemical form in soil solution. Stable I (127I) in the soil solution under actual soil conditions was investigated as a natural analogue of long-lived radioiodine (129I). Soil samples were collected at 5-cm depth intervals down to 20 cm from forests and grasslands in Rokkasho, where the Japanese first commercial nuclear fuel reprocessing plant is located, and the soil solution was extracted by centrifugation. Almost half of total I in the soil solution was iodide, and the other half was dissolved organic I (DOI), with iodate under the detection limit. The proportion of DOI in total I at 0-5 cm depth was larger than the proportions at 5-20 cm depth. The concentration of DOI was positively correlated with that of DOC in the soil solution, suggesting that the behaviour of DOI in the surface soil is affected by labile organic matter dynamics.

Changes in the chemical form of exogenous iodine in forest soils and their extracts

Information about the chemical form of exogenous iodine in soil is important for predicting the mobility and behaviour of radioiodine in the terrestrial environment. In this study, soil samples collected at various depths in a pine forest in Rokkasho, Japan, were spiked with stable iodine (as iodide or iodate); after incubation of the spiked soils for 1 or 14 d, the chemical forms of iodine were investigated in both the soils and their water extracts. In surface soil and its extracts, inorganic iodine was found to have been transformed to organically bound forms after incubation for 14 d, resulting in a decrease in the amount of water-extractable iodine in the soil. In contrast, in subsurface soil, which had low organic matter content, the predominant chemical form of iodine after incubation did not differ from that in the spiked soil, and the amount of water-extractable iodine did not decrease noticeably.

The role of tissue thromboplastin in the development of DIC accompanying neoplastic diseases

Procoagulant activity of gastric cancer tissues and leukocytes obtained from various types of leukemia have been studied with special reference to TTP. The following results were obtained. Homogenates of APL leukocytes and gastric cancer tissues contained strong procoagulant activities, most of which have been identified as TTP since the activities were neutralized by a specific antibody against purified human placenta TTP, inactivated by the removal of phospholipid with heptane-butanol mixture, and inactivated by the addition of phospholipase C. The delipidated homogenates regained procoagulant activities by relipidation procedures. These results also confirmed that TTP from APL leukocytes and gastric cancer tissues have the same lipoprotein properties as those of TTP in normal tissues. Though slight proteolytic activity and fibrinolytic activity were demonstrated in the homogenate of gastric cancer tissues, it was noted that the TTP activity was different from these two activities by partial purification of TTP from gastric cancer tissues. The TTP activity of 9 homogenates of gastric cancer tissues was 301 +/- 289 (mean +/- SD) units per mg protein, being higher in homogenates of mucinous adenocarcinoma and signet-ring cell carcinoma than in those of tubular and poorly differentiated adenocarcinoma. The mean TTP activity of leukocyte homogenates from 14 patients with APL and one out of 4 patients with CML in blastic crisis was 81 +/- 76 units/10(7) cells. The TTP activity of the homogenates of leukocytes from 7 out of 18 patients with AML and another patient with CML in blastic crisis ranged from one to six units/10(7) cells with a mean of 3.3 +/- 1.2. The TTP activity of leukocyte homogenates from the other 11 cases of AML, two cases of CML in blastic crisis, 6 cases of CML, and one case each of ALL and CLL were less than one unit/10(7) cells. In leukemic patients, all cases with a value of more than 202 for the product of units of TTP activity per 10(7) cells and differential count (%) of leukemic cells in the bone marrow smear (MU value) were accompanied by DIC. The MU value of leukemic patients correlated well to the plasma fibrinogen and serum FDP levels. All patients with a MU value of more than 277 died of DIC when a sufficient amount of heparin was not administered. On the other hand, no DIC developed in any of the patients with a MU value of less than 90.(ABSTRACT TRUNCATED AT 400 WORDS)

Radiocesium and radioiodine in soil particles agitated by agricultural practices: field observation after the Fukushima nuclear accident

Three weeks after the accident at the Fukushima Daiichi Nuclear Power Plant, we determined the activity concentrations of (131)I, (134)Cs and (137)Cs in atmospheric dust fugitively resuspended from soil particles due to soil surface perturbation by agricultural practices. The atmospheric concentrations of (131)I, (134)Cs and (137)Cs increased because of the agitation of soil particles by a hammer-knife mower and a rotary tiller. Coarse soil particles were primarily agitated by the perturbation of the soil surface of Andosols. For dust particles smaller than 10 μm, the resuspension factors of radiocesium during the operation of agricultural equipment were 16-times higher than those under background condition. Before tillage, most of the radionuclides accumulated within a few cm of the soil surface. Tillage diluted their concentration in the uppermost soil layer.

Early recurrence after surgical resection in patients with pathological stage I non-small cell lung cancer

INTRODUCTION

Early recurrence is observed even in patients who undergo complete resection and had pathological (p-) stage I. Therefore, we focused on early recurrence, and attempted to elucidate the relationship between early recurrence and clinicopathological factors.

METHODS

Between May 1993 and December 2005, 1201 patients with non-small cell lung cancer (NSCLC) underwent surgical treatment at our institution. Of these, 402 patients who underwent complete resection and had p-stage I NSCLC were retrospectively analyzed for clinicopathological factors. Patients were divided into four groups according to the period between surgery and recurrence (R): no recurrence (NR, n = 331), late recurrence (LR, n = 28, R > 2 years), intermediate recurrence (IR, n = 22, 1 year < R < or = 2 years), and early recurrence (ER, n = 21, R < or = 1 year).

RESULTS

The overall 5-year survival rate for patients with p-stage I was 79.9 %. The overall 5-year survival rates were 91.0 %, 55.6 %, 17.1 %, and 7.5 % for the NR, LR, IR, and ER group, respectively. Preoperative high CEA level, lymphatic permeation, and pleural invasion were proven to be independent factors for overall recurrence. Moreover, multivariate analysis showed that preoperative CEA level, pathological T factor, lymphatic permeation, vascular invasion, and pleural invasion influenced early recurrence within one year.

CONCLUSIONS

The present study demonstrated that preoperative CEA level, pathological T-factor, lymphatic permeation, vascular invasion, and pleural invasion were independent prognostic factors for early recurrence within one year, even in patients with pathological stage I. In patients with these factors, adjuvant therapy may be indicated since this may improve their survival.

[Surgical outcome of tracheobronchial reconstruction for lung cancer]

We retrospectively evaluated the surgical outcome after sleeve lobectomy and pneumonectomy with tracheobronchial reconstruction for lung cancer. From 1993 to 2008, 46 patients with primary lung cancer underwent these surgical procedures. Seventeen patients (37%) received induction therapy, 15 received chemotherapy, while chemoradiotherapy or radiotherapy alone were received by one patient each. Sleeve lobectomy without carinal resection was performed in 41 patients. Carinal resection with 2 sleeve pneumonectomies was performed in 5 patients. There were no operative deaths. Bronchopleural fistula occurred in one patient, who required completion pneumonectomy. One patient presented local mucosal necrosis in the anastomotic site and was managed conservatively. Two patients had bronchial strictures as late complications and successfully dilated by a balloon using bronchoscopy. Overall 5-year and 10-year survival rates were 54% and 48%, respectively. No recurrence developed at any anastomotic site. The results showed that sleeve lobectomy and pneumonectomy with tracheobronchial reconstruction can be performed with low mortality and bronchial anastomotic complication rates. As well, local control of the tumor was satisfactory.

Randomized controlled trial comparing docetaxel (D)-cisplatin (P) combination with D alone in elderly patients (pts) with advanced non-small cell lung cancer (NSCLC): JCOG0207

7629

Background: Platinum-based chemotherapy is currently recommended as the standard approach for pts with advanced NSCLC. However prospective clinical trials specifically designed for elderly pts demonstrating the P benefit are still lacking. Therefore, we conducted a phase III trial to determine whether the addition of P to single agent-chemotherapy for elderly NSCLC pts could improve survival. Methods: Eligibility criteria included; chemotherapy-naive; stage III/IV NSCLC; age=70 and PS 0–1. Pts were randomized to receive either DP or D with minimization method balancing site, age (=74/=75) and stage (III/IV), and both regimens were given every 4 weeks. DP comprised D (20 mg/m2) and P (25 mg/m2) iv on days 1, 8, 15. D comprised D (25 mg/m2) iv on the same schedule. Primary endpoint was overall survival (OS). The planned sample size was 115 pts in each arm to provide 80% power to detect 0.667 hazard ratio for DP to D in OS and 2.5% one-sided alpha. Results: Between Apr 2003 and Apr 2006, 126 pts were randomized (D/DP: 63/63). The second planned interim analysis was performed on 112 assessable pts (D/DP:56/56, median age 76, =74/=75: 39/61%, male/female: 77/23%, PS 0/1: 39/61%, III/IV: 30/70%). Maturity of information, defined proportion of interim events to the planned events, was 26% (=49/191). As the one-sided p-value(p=0.00515) of the stratified log-rank test by age and stage was not lower than the critical value for the interim analysis, the formal criterion for stopping the trial failed to meet. However the Data and Safety Monitoring Board recommended study termination and disclosure of the results based on the strong interaction (two-sided p=0.077, hazard ratios [95% C.I.] for =74/=75: 0.23 [0.09–0.62]/0.72 [0.35- 1.49]) that DP may be beneficial for subgroup of age between 70- 74. Major Grade 3–4 toxicities were (%D/DP): neutropenia 4.9/13.1, anemia 1.6/16.4, anorexia 8.3/24.2, infection 11.7/8.1, pneumonitis 1.7/1.6. TRD occurred in 1 pt in DP arm. Conclusions: The interpretation of study results is limited due to early stopping and resultant loss of statistical power. But these data indicated that =74 young elderly have no more need to evaluate tolerability and efficacy of P.

No significant financial relationships to disclose.

Domain-related differentiation of working memory in the Japanese macaque (Macaca fuscata) frontal cortex: a positron emission tomography study

The lateral prefrontal cortex (LPFC) is important for working memory (WM) task performance. Neuropsychological and neurophysiological studies in monkeys suggest that the lateral prefrontal cortex is functionally segregated based on the working memory domain (spatial vs. non-spatial). However, this is not supported by most human neuroimaging studies, and the discrepancy might be due to differences in methods and/or species (monkey neuropsychology/physiology vs. human neuroimaging). We used positron emission topography to examine the functional segregation of the lateral prefrontal cortex of Japanese macaques (Macaca fuscata) that showed near 100% accuracy on spatial and non-spatial working memory tasks. Compared with activity during the non-working memory control tasks, the dorsolateral prefrontal cortex (DLPFC) was more active during the non-spatial, but not during the spatial, working memory task, although a muscimol microinjection into the dorsolateral prefrontal cortex significantly impaired the performance of both working memory tasks. A direct comparison of the brain activity between the two working memory tasks revealed no differences within the lateral prefrontal cortex, whereas the premotor area was more active during the spatial working memory task. Comparing the delay-specific activity, which did not include task-associated stimulus/response-related activity, revealed more spatial working memory-related activity in the posterior parietal and premotor areas, and more non-spatial working memory-related activity in the dorsolateral prefrontal cortex and hippocampus. These results suggest that working memory in the monkey brain is segregated based on domain, not within the lateral prefrontal cortex but rather between the posterior parietal-premotor areas and the dorsolateral prefrontal-hippocampus areas.

F-18 fluorodeoxyglucose uptake in leiomyomatous uterus

Leiomyomas of uterus are common disease in gynecology. It is important to differentiate leiomyoma from leiomyosarcoma at the decision of treatment methods, especially in the case of the conservative treatment for uterine leiomyoma. But the exact diagnosis of benign leiomyoma is often difficult due to the degeneration of myoma by imaging modalities including magnetic resonance imaging. Recently, whole-body positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) has been used for a diagnosis of malignant tumors. There is a growing body of evidence for the use of FDG in differentiating malignant from benign disease. But optimal utilization in gynecology remains unclear. Our case represents increased uptake of FDG in myomatous uterus, which is pathologically confirmed benign leiomyoma by the hysterectomy. Immunohistochemical analysis of glucose transporter-1 showed positive in endometrial tissue and negative in leiomyoma. Our case indicates that myomatous uterus in premenopausal women shows the potential pitfall of a positive result of FDG-PET.

Whole-body positron emission tomography with F-18 fluorodeoxyglucose for the detection of recurrence in uterine sarcomas

We evaluated the usefulness of whole-body positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG-PET) for the detection of recurrence in follow-up patients after primary treatment of uterine sarcoma. Eight patients with pathologically proven uterine sarcoma underwent FDG-PET, computed tomography (CT), and ultrasonography (US). Final diagnoses of recurrence were established in five cases (three carcinosarcomas and two leiomyosarcomas). PET revealed recurrent sites in the intraperitoneum, liver, lung, bone, and retroperitoneal lymph nodes. However, the minimum size of the tumor detected by PET depended on the sites of recurrence. CT and US images showed two false-negative cases of intraperitoneal tumors. PET was able to detect a solitary small intraperitoneal tumor, which was very difficult to detect by CT and US. Positive PET findings did not affect the prognosis in three of the five recurrent patients; however, the remaining two patients consequently underwent the combination therapy consisting of surgery and chemotherapy and survived for more than 1 year after the positive FDG-PET results. Application of PET imaging for the early detection of recurrent sites was useful for the decision of treatment strategy for patients with recurrent uterine sarcoma.

Whole-body positron emission tomography and tumor marker CA125 for detection of recurrence in epithelial ovarian cancer

We evaluated the clinical role of the combination of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and tumor marker CA125, in the detection of recurrence after initial therapy for epithelial ovarian cancer. The indication is the cases that cannot be confirmed the recurrence by conventional imaging modalities. Ninety patients underwent PET and computed tomography, including the measurement of specific tumor markers. FDG-PET confirmed recurrence in 46 patients (51%), and the recurrent site was confirmed by PET alone in 17 (37%). PET had high sensitivity for detecting both intraperitoneal and retroperitoneal metastases (93.9 and 92.9%, respectively). PET imaging was able to detect normal-sized metastases in the lymph nodes in 14 (50%) of the 28 patients with retroperitoneal metastasis. PET could show 87.5% positive rate of recurrent patients with asymptomatic rise of CA125 who had no sign of recurrence by conventional imaging methods. Of the 46 recurrent patients, 41 (89%) had specific elevated titers of CA125 at the first treatment. PET imaging was able to detect recurrence at relatively low titers (a median 68 U/mL) of CA125. In 8 (19.5%) of these 41 patients, recurrence with normal CA125 levels could be confirmed only by PET. The sensitivity of the combination of PET and CA125 was 97.8% with only one false-negative case. The combination of FDG-PET and CA125 titer is useful for the accurate detection of recurrence.

Whole-body positron emission tomography and tumor marker CA125 for detection of recurrence in epithelial ovarian cancer

We evaluated the clinical role of the combination of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and tumor marker CA125, in the detection of recurrence after initial therapy for epithelial ovarian cancer. The indication is the cases that cannot be confirmed the recurrence by conventional imaging modalities. Ninety patients underwent PET and computed tomography, including the measurement of specific tumor markers. FDG-PET confirmed recurrence in 46 patients (51%), and the recurrent site was confirmed by PET alone in 17 (37%). PET had high sensitivity for detecting both intraperitoneal and retroperitoneal metastases (93.9 and 92.9%, respectively). PET imaging was able to detect normal-sized metastases in the lymph nodes in 14 (50%) of the 28 patients with retroperitoneal metastasis. PET could show 87.5% positive rate of recurrent patients with asymptomatic rise of CA125 who had no sign of recurrence by conventional imaging methods. Of the 46 recurrent patients, 41 (89%) had specific elevated titers of CA125 at the first treatment. PET imaging was able to detect recurrence at relatively low titers (a median 68 U/mL) of CA125. In 8 (19.5%) of these 41 patients, recurrence with normal CA125 levels could be confirmed only by PET. The sensitivity of the combination of PET and CA125 was 97.8% with only one false-negative case. The combination of FDG-PET and CA125 titer is useful for the accurate detection of recurrence.

Evaluation of [18F]fluorinated sigma receptor ligands in the conscious monkey brain

PET-imaging of the sigma receptors is very helpful to understand processes, e.g., several central nervous system (CNS)-diseases in which the sigma receptors are involved. The [(18)F]fluoroethylated analogs of SA4503 and SA5845 ([(18)F]FE-SA4503 and [(18)F]FE-SA5845) were evaluated in conscious monkeys to estimate its suitability for human application for PET. Conscious monkeys (Macaca Mulatta) were either scanned with [(18)F]FE-SA4503 or [(18)F]FE-SA5845 (n = 3 for both groups, 220-802 MBq). After a dynamic study of 120 min, radioactivity was displaced by intravenous (i.v.) injection of haloperidol (1 mg/kg). One month later the same set of three monkeys were scanned with [(18)F]FE-SA4503 for 120 min and "cold" SA4503 (1 mg/kg) was infused to displace the radioactivity, and the other three monkeys were pretreated with haloperidol (1 mg/kg) before the 120-min PET-scan with [(18)F]FE-SA5845. Cortical areas (cingulate, frontal, occipital, parietal, temporal), striatum, and thalamus showed high radioactivity uptake. Infusion of haloperidol displaced the radioactivity levels of the two radioligands. The same effect was found for [(18)F]FE-SA4503 after SA4503 displacement. Pretreatment with haloperidol blocked the [(18)F]FE-SA5845 binding to give PET-images with low and uniform uptake in the brain. The findings demonstrated the reversible binding of the two radioligands. Metabolite analysis showed that 14% and 23% parent compound of [(18)F]FE-SA5845 and [(18)F]FE-SA4503, respectively, at 120 min postinjection was present in plasma. Kinetic analysis showed that the binding potential of [(18)F]FE-SA5845 was higher in all brain regions than that of [(18)F]FE-SA4503 (4.75-8.79 vs. 1.65-4.04). The highest binding potential was found in the hippocampus, followed by the cortical regions, thalamus, cerebellar hemisphere, striatum and vermis. Both [(18)F]FE-SA compounds bound specifically to cerebral sigma receptors of the monkey and have potential for mapping sigma receptors in the human brain.

[Clinicopathologic features of small-sized peripheral lung cancer; is intentional limited resection appropriate for selected patients?]

We sought to determine the eligibility of patients with early peripheral lung cancer for intentional limited resection. The clinicopathologic features of 103 patients who underwent lobectomy and mediastinal nodal dissection for early stage peripheral lung cancer measuring 2 cm or less in maximum dimension between 1992 and 2002 were examined retrospectively. The lymph node metastasis and residual cancer after thoracoscopic partial resection were analyzed by the following categories. Three groups were divided by maximum dimension of the primary lesion in the resected specimen; 10 mm or less (n = 11), 15 mm or less (n = 33), and 20 mm or less (n = 59). Two groups were divided by lesion histology; bronchioloalveolar adenocarcinoma (BAC) [n = 42] and invasive lung cancer (n = 61). Residual cancer was found in the residual lobe after thoracoscopic partial resection in 3 of 43 patients who had no diagnosis preoperatively. Their maximum dimensions were 15 mm or less. No lymph node metastasis was detected in the patients with tumor measuring 10 mm or less, and BAC. Intentional limited resection without mediastinal nodal dissection is appropriate for patients with tumor measuring 10 mm or less and BAC. Further investigation associated with partial resection is necessary.

Effects of an aldose reductase inhibitor on gastroenteropathy in streptozotocin-diabetic rats

We investigated the effects of epalrestat, an aldose reductase inhibitor (ARI), on gastric emptying, fecal water content, and electrolyte transport in distal colon in streptozotocin (STZ)-induced diabetic rats. We measured gastric emptying time by acetaminophen method and short-circuit-current (Isc) in colonic mucosa using an Ussing chamber. The Isc in response to electric-field-stimulation (EFS) was decreased in untreated rats due to suppression by Cl- secretion. ARI treatment alleviated this suppression (2.7 +/- 0.6 vs. 7.4 +/- 1.1 microA/0.38 cm2 at 8 weeks after treatment, 1.1 +/- 0.2 vs. 7.0 +/- 1.0 at 12 weeks after treatment, P<0.05). In addition, the percentage of fecal water content in untreated rats was significantly lower than in ARI-treated rats (58.0 +/- 2.0 vs. 67.6 +/- 0.8% at 8 weeks, 56.9 +/- 2.1 vs. 63.4 +/- 1.4 at 12 weeks, P<0.05). From STZ injection to 8 weeks, the serum levels of acetaminophen in the diabetic rats were significantly lower than in controls, indicating delayed gastric emptying. At 12 weeks in the diabetic rats treated with ARI, the serum levels of acetaminophen were significantly higher than in the untreated diabetic rats (6.6 +/- 0.4 vs. 3.5 +/- 0.5 microg/ml, P<0.05). ARI-treatment ameliorated delayed gastric emptying without improving glycemic control. These findings show that ARI partially prevented progression of impaired gastric emptying, ion transport, and water transport, and suggest that epalrestat might be useful in the treatment of diabetic gastroenteropathy.

[Clinical outcome of epithelial tumors of the thymus]

OBJECTIVE AND METHODS

We retrospectively reviewed treatment and clinical outcome of thymic epithelial tumors of 64 patients over a 20-year period. Clinical staging of the tumor was done by according to Masaoka classification. Histological diagnosis of the tumors was done by according to the second edition of the WHO histologic classification system for thymic epithelial tumors. Survival rate was calculated after Kaplan-Meire method.

RESULTS

Median age of patients was 53.7 years (ranged from 16 to 81). There were 30 men and 34 women. Eighteen patients had auto-immuno diseases. Sixty-two patients underwent surgery. In 57 patients resection was complete (extended thymo-thymectomy), but in the other five incomplete. The operative approach was median sternotomy in 51 patients and video-assisted thoracoscopic surgery in 6. Stage II to IV patients had postoperative mediastinal irradiation. Stage III to IV patients had postoperative cisplatin (CDDP) based chemotherapy. Inoperable patients were treated by chemo-radiotherapy. There were 42 stage I, 7 stage II, 11 stage III, 3 stage IV a, 1 stage IV b. The 5-year/10-year survival rates were 93%/89%, 71%/71%, 68.5%/--in patients with stage I, II and III. There were 5 type A tumors, 8 type AB tumors, 11 type B1 tumors, 11 type B2 tumors, 9 type B3 tumors, 11 type C tumors, the respect 5-year survival rates were 100%, 100%, 87.5%, 60%, 85.7% and 90%. Masaoka stage II to IV patients classified in B2, B3 and C type except one case.

CONCLUSION

Histologic type B2, B3 and C tumors may reflect the invasive nature. Masaoka staging system and the WHO histologic classification may help the assessment and treatment of patients with thymic epithelial tumor.

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

DNA analysis of nosocomial infection by Enterobacter aerogenes in three cases of septicaemia in Japan

Ceftazidime-resistant Enterobacter aerogenes was isolated from blood cultures of three patients with fever. DNA analysis using pulsed-field gel electrophoresis and ribosomal RNA gene restriction digest pattern analysis revealed that the strains were clonally similar to each other with a 79.3-96.0% homology. The same strain of E. aerogenes was isolated from a three-way stopcock connected to the indwelling catheter in one of the patients at a concentration of 45 cfu/mL. A similar strain was also isolated from the urine of one other patient on the same floor. The data suggest that E. aerogenes caused septicaemia via low bacterial contamination of a three-way stopcock in a peripheral drip intravenous infusion system in at least one patient, and that the outbreak of E. aerogenes infections was due to clonally-related strains.

Synthesis and evaluation of [18F]fluoroethyl SA4503 as a PET ligand for the sigma receptor

The sigma receptor might be involved in several diseases in the central nervous system. It occurs in the endocrine, immune, and other peripheral organ systems and is expressed in a variety of human tumors. The [18F]fluoroethyl analog of the sigma1-selective ligand SA4503 ([18F]FE-SA4503) was prepared and evaluated in animals to investigate its suitability for in vivo measurement of sigma receptors with positron emission tomography (PET). [18F]FE-SA4503 was synthesized by [18F]fluoroethylation of the corresponding O-demethyl precursor in an overall radiochemical yield of 4-7% (EOB) with a specific activity of >100 TBq/mmol. The radioligand had higher in vitro affinity for the sigma receptor than SA4503 (IC(50) sigma1 6.48 nM, IC50 sigma2 2.11 nM). [18F]FE-SA4503 was injected into mice. Uptake could be blocked by co-injection of the sigma receptor ligands haloperidol, pentazocine, and cold SA4503, but not with other receptor ligands. Ex vivo autoradiography studies in rats showed regional distribution in the brain similar to [11C]SA4503. Hippocampus, thalamus, and cortical areas were clearly delineated by [18F]FE-SA4503. The uptake was blocked by SA4503 treatment. In the rat brain, only a small portion of metabolites (6.6% of brain radioactivity) was detected at 30 min postinjection, whereas in plasma the fraction of metabolites amounted to 51.3% of plasma radioactivity. The kinetics of [18F]FE-SA4503 was measured with PET in the conscious monkey brain. High uptake values were found in the cortex, thalamus, cerebellum, and striatum, reaching a plateau value at 30 min postinjection. It is concluded that [18F]FE-SA4503 showed specific binding to sigma receptors in three animal species.

Yohimbine increases the binding potential for [11C]flumazenil in the monkey brain

We evaluated the impact of yohimbine administration on benzodiazepine (BDZ) receptor binding in the central nervous system of non-human primates (rhesus monkeys). Estimates of the binding potential (Bmax/Kd) of BDZ receptors were made following intravenous administration of yohimbine, an alpha2-adrenoceptor antagonist. Positron emission tomography was used in conjunction with [11C]flumazenil (Ro 15-1788), a tracer for central BDZ receptor binding activity. The effects of yohimbine were compared with a control condition in which saline was administered. Yohimbine significantly increased the binding potential in the hippocampus, as assessed using a Student's t-test with Bonferroni correction. The result that the administration of yohimbine readily induces an increase in the binding potential for BDZ receptors in the primate brain suggests that the presence of an anxiety state potentiates the effect of anxiolytics.

Rice uptake and distributions of radioactive 137Cs, stable 133Cs and K from soil

The distributions of radionuclides in plant components as to radionuclide transfer to animals are important for understanding the dynamics of radionuclides in an agricultural field. Most of the non-edible parts in these components are returned to the soil as organic fertilizer where they may again be utilized in the soil-plant pathway and/or are mixed with feed for livestock. Rice plants were grown in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, leaves, stem and root, and then the distributions of radioactive 137Cs, stable 133Cs and K in these components were determined. The distribution of 137Cs in polished rice and rice bran was similar to that of 133Cs, while that of K was different. The concentration ratios of 133Cs/K in leaf blade positions increased with aging, which means that the translocation rate of 133Cs in rice plants was slower than that of K. At harvest the distribution of dry weight in polished rice to entire rice plants was 34%, and the distributions of 133Cs in the polished rice and the non-edible parts were 7 and 93%, respectively, whereas those of K in the polished rice and the non-edible parts were 2 and 98%, respectively. Findings suggest that the transfer and distribution of 133Cs, not of K, provide better information on the long-term fate of 137Cs in an agricultural environment.

Facilitation of dopaminergic neural transmission does not affect [(11)C]SCH23390 binding to the striatal D(1) dopamine receptors, but the facilitation enhances phosphodiesterase type-IV activity through D(1) receptors: PET studies in the conscious monkey brain

The present study evaluated the effects of methamphetamine and scopolamine on the striatal dopamine D(1) receptor binding, measured by [(11)C]SCH23390, and D(1) receptor-coupled cAMP messenger system, determined as phosphodiesterase type-IV (PDE-IV) activity, were evaluated in the brains of conscious monkeys using positron emission tomography (PET) with microdialysis. When methamphetamine (0.1, 0.3, and 1 mg/kg) or scopolamine (0.01, 0.03, and 0.1 mg/kg) was systemically administered, [(11)C]SCH23390 binding to D(1) receptors was not affected. With administration of methamphetamine, the striatal PDE-IV activity, as measured with R-[(11)C]rolipram (active form) and S-[(11)C]rolipram (inactive form), was dose-dependently facilitated with enhanced dopamine level in the striatal ECF. Administration of scopolamine also induced facilitated PDE-IV activity without any apparent changes in the ECF dopamine. These facilitations of PDE-IV activity were abolished by preadministration of SCH23390, but not by raclopride. These results demonstrate that, as evaluated by PDE-IV activity, the inhibition of muscarinic cholinergic receptors actually facilitated dopamine neuronal signal transduction through D(1) receptors, as observed previously on D(2) receptors with no apparent increase in the striatal ECF dopamine level, but the enhanced dopamine transmission could not detected by [(11)C]SCH23390.

Effects of aging on 5-HT(1A) receptors and their functional response to 5-HT(1a) agonist in the living brain: PET study with [carbonyl-(11)C]WAY-100635 in conscious monkeys

Age-related changes in the serotonin 5-HT(1A) receptors in the living brains of conscious young (5.9 +/- 1.8 years old) and aged (19.0 +/- 3.3 years old) monkeys (Macaca mulatta) were evaluated by [carbonyl-(11)C]WAY-100635 and high-resolution positron emission tomography (PET). The regional distribution pattern of [carbonyl-(11)C]WAY-100635 at 60-91 min postinjection was the highest in the cingulate gyrus and hippocampus, high in the frontal and temporal cortices, lower in the occipital cortex, striatum, thalamus, and raphe nuclei, and lowest in the cerebellum in both young and aged monkeys. Graphical Logan plot analysis with metabolite-corrected plasma radioactivity as an input function into the brain was applied to evaluate 5-HT(1A) receptor binding in vivo. Significant age-related decreases in 5-HT(1A) receptor binding were observed only in the frontal and temporal cortices. In the hippocampus, although 5-HT(1A) receptor binding indicated no significant age-related changes, it showed an inverse correlation with individual cortisol levels in plasma. When the 5-HT(1A) receptor agonist 8-OH-DPAT was administered intravenously at a dose of 0.1, 0.3, or 1 mg/kg 30 min after tracer injection, binding of [carbonyl-(11)C]WAY-100635 was displaced in both age groups in a dose-dependent manner. However, the degree of displacement was more marked in young than in aged monkeys. These observations demonstrated the usefulness of [carbonyl-(11)C]WAY-100635 as an indicator of the age-related changes in cortical 5-HT(1A) receptors measured noninvasively by PET. In addition, these observations suggested that the age-related impairment of 5-HT(1A) receptor responses to 8-OH-DPAT might be related to the reduced efficacy of antidepressant therapy in elderly patients with depression.

Ketamine alters the availability of striatal dopamine transporter as measured by [(11)C]beta-CFT and [(11)C]beta-CIT-FE in the monkey brain

The effects of ketamine anesthesia on the binding of [(11)C]-labeled cocaine analogs, [(11)C]beta-CFT (2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane) and [(11)C]beta-CIT-FE (N-(2-fluoroethyl)-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane), to the striatal dopamine transporter (DAT) were evaluated in the monkey brain using positron emission tomography (PET). We sequentially measured the kinetics of these labeled compounds in the brains of five young-adult male rhesus monkeys (Macaca mulatta) in the conscious state, followed by those under ketamine anesthesia with continuous infusion (3 and 10 mg/kg/h). After intravenous injection, [(11)C]beta-CFT and [(11)C]beta-CIT-FE were predominantly accumulated in the striatum in both conscious and ketamine-anesthetized states. In the conscious state, the striatal uptake of [(11)C]beta-CFT and [(11)C]beta-CIT-FE continuously increased with time up to 91 min after injection. Continuous infusion of ketamine-induced higher levels of uptake of [(11)C]beta-CFT and [(11)C]beta-CIT-FE into the brain in a dose-dependent manner as compared with conscious state, and kinetic analysis with metabolite-corrected arterial input function indicated that the binding potentials (BP = k(3)/k(4)) of both compounds were elevated by ketamine. Not only [(11)C]beta-CIT-FE but also [(11)C]beta-CFT reached the equilibrium state of specific binding in the striatum within 40-50 min after injection. The present results demonstrated that ketamine significantly alters the DAT availability as measured with [(11)C]beta-CFT and [(11)C]beta-CIT-FE in the brain.

Randomised comparison of ondansetron plus dexamethasone with dexamethasone alone for the control of delayed cisplatin-induced emesis

The role of 5-hydroxytryptamine(3) (HT(3)) antagonists in the treatment of delayed emesis is still controversial. To evaluate whether 5-HT(3) antagonists can add to the efficacy of corticosteroids in controlling delayed emesis, we performed a randomised, prospective, open study comparing ondansetron plus dexamethasone with dexamethasone alone in cisplatin-treated patients. 149 cisplatin-naïve patients with lung cancer received at least 60 mg/m(2) of cisplatin and were treated with dexamethasone 32 mg intravenously (i.v.) and granisetron 3 mg i.v. on day 1. Patients were randomly assigned to receive either dexamethasone 16 mg i.v. alone (arm A) or dexamethasone plus ondansetron 8 mg daily (arm B) on days 2-4. None of the efficacy variables related to control of delayed emesis differed significantly between the two arms. In conclusion, there does not appear to be sufficient evidence to support the prolonged use of 5-HT(3) receptor antagonists after 24 h of cisplatin-containing chemotherapy.

FK506 attenuates early ischemic neuronal death in a monkey model of stroke

FK506 is an immunosuppressive agent that has been reported to have neuroprotective effects in several kinds of rodent models of stroke. The purpose of this study was to evaluate the neuroprotective effects of FK506 in a monkey model of stroke.

METHODS

Cynomolgus monkeys underwent 3 h of occlusion followed by 5 h of reperfusion of the right middle cerebral artery (MCA) through a transorbital approach. A single bolus dose of FK506 (0.1 mg/kg) was injected intravenously 5 or 175 min after MCA occlusion. Eight hours after ischemia, a neuropathologic study was performed and the volume of ischemic damage was determined. To measure local cerebral blood flow (CBF), the cerebral metabolic rate of oxygen (CMRO(2)), and the oxygen extraction fraction during the experiments, PET scans were obtained using a steady-state (15)O continuous-inhalation method. Four consecutive PET scans (before and 2 h after ischemia and immediately and 3 h after reperfusion) were obtained on each monkey.

RESULTS

Treatment with FK506 (0.1 mg/kg) 5 or 175 min after ischemia significantly reduced cortical damage 8 h after ischemia by 82% (P < 0.05) and 73% (P < 0.05), respectively. In PET studies, FK506 did not affect CBF or physiologic parameters in any treatments. In the FK506-treated group, a volume of >40% CMRO(2) reduction 3 h after reperfusion decreased significantly (P < 0.05).

CONCLUSION

This study showed that FK506 showed a powerful neuroprotective effect in a nonhuman primate model of stroke. The therapeutic time window of FK506 was at least 3 h after onset. PET studies detected neuroprotective effects only in areas with >40% CMRO(2) reduction 3 h after reperfusion.