Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Nomograms predicting survival and recurrence in colonic cancer in the era of complete mesocolic excision

Background

More extensive lymphadenectomy may improve survival after resection of colonic cancer. Nomograms were created predicting overall survival and recurrence for patients who undergo D2-D3 lymph node dissection, and their validity determined.

Methods

This was a multicentre study of patients with colonic cancer who underwent resection with D2-D3 lymph node dissection in Japan. Inclusion criteria included R0 resection. A training cohort of patients operated on from 2007 to 2008 was analysed to construct prognostic models predicting survival and recurrence. Discrimination and calibration were performed using an external validation cohort from the Japanese colorectal cancer registry (procedures in 2005-2006).

Results

The training cohort consisted of 2746 patients. Predictors of survival were: age (hazard ratio (HR) 1·04), female sex (HR 0·71), depth of tumour invasion (HR 1·15, 1·22, 2·96 and 3·14 for T2, T3, T4a and T4b respectively versus T1), lymphatic invasion (HR 1·11, 1·15 and 2·95 for ly1, ly2 and ly3 versus ly0), preoperative carcinoembryonic antigen (CEA) level (HR 1·21, 1·59 and 1·99 for 5·1-10·0, 10·1-20·0 and 20·1 and over versus 0-5·0 ng/ml), number of metastatic lymph nodes (HR 1·07), number of lymph nodes examined (HR 0·98) and extent of lymphadenectomy (HR 0·23, 0·13 and 0·11 for D1, D2 and D3 versus D0). Predictors of recurrence were: female sex (HR 0·82), macroscopic type (HR 3·82, 4·56, 6·66, 7·74 and 3·22 for types I, II, III, IV and V versus type 0), depth of invasion (HR 1·25, 2·66, 5·32 and 6·43 for T2, T3, T4a and T4b versus T1), venous invasion (HR 1·43, 3·05 and 4·79 for v1, v2 and v3 versus v0), preoperative CEA level (HR 1·39, 1·43, 1·56 and 1·85 for 5·1-10·0, 10·1-20·0, 20·1-40·0 and 40·1 or more versus 0-5 ng/ml), number of metastatic lymph nodes (HR 1·07) and number of lymph nodes examined (HR 0·98). The validation cohort comprised 4446 patients. The internal and external validated Harrell's C-index values for the nomogram predicting survival were 0·75 and 0·74 respectively. Corresponding values for recurrence were 0·78 and 0·75.

Conclusion

These nomograms could predict survival and recurrence after curative resection of colonic cancer.

A self-excited threshold autoregressive state-space model for menstrual cycles: Forecasting menstruation and identifying within-cycle stages based on basal body temperature

The menstrual cycle is divided into hypothermic and hyperthermic phases based on the periodic shift in the basal body temperature (BBT), reflecting events occurring in the ovary. In the present study, we proposed a state-space model that explicitly incorporates the biphasic nature of the menstrual cycle, in which the probability density distributions for the advancement of the menstrual phase and that for the BBT switch depending on a latent state variable. Our model derives the predictive distribution of the day of the next menstruation onset that is adaptively adjusted by accommodating new observations of the BBT sequentially. It also enables us to obtain conditional probabilities of the woman being in the early or late stages of the cycle, which can be used to identify the duration of hypothermic and hyperthermic phases, possibly as well as the day of ovulation. By applying the model to real BBT and menstruation data, we show that the proposed model can properly capture the biphasic characteristics of menstrual cycles, providing a good prediction of the menstruation onset in a wide range of age groups. The application of the proposed model to a large data set containing 25 622 cycles provided by 3533 women further highlighted the between-age differences in the population characteristics of menstrual cycles, suggesting its wide applicability.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Modeling and simulation of bone mineral density in Japanese osteoporosis patients treated with zoledronic acid using tartrate-resistant acid phosphatase 5b, a bone resorption marker

Annual intravenous administration of zoledronic acid is used in the treatment of osteoporosis. A mathematical model was developed to predict bone mineral density up to 2 years after two annual doses of zoledronic acid from the early values of a bone resorption marker in osteoporosis patients.

INTRODUCTION

The measurement of bone mineral density (BMD) has been used as a surrogate marker instead of the observation of incident fractures to detect the efficacy of treatment. However, this method requires a long time to obtain significant changes. On the other hand, bone resorption markers respond to bone resorption inhibitors within a few weeks. Therefore, the aim of this study was to develop a mathematical model predicting long-term BMD after two annual doses of zoledronic acid (ZOL) using the early response of a bone resorption marker in osteoporosis patients.

METHODS

The model was constructed using 3410 tartrate-resistant acid phosphatase 5b (TRACP-5b) serum concentrations and 1146 lumbar spine (L2-L4) BMD values from 306 patients with primary osteoporosis. A mathematical model was developed to describe the time-dependent profiles of TRACP-5b and BMD.

RESULTS

The percentage changes from baseline of the BMD (%BMD) at up to 2 years were predicted from patients' baseline BMD and baseline and 12-week TRACP-5b values by the model obtained. The simulated 90% prediction interval almost covered the observed %BMD distribution at each time point, and the predictions were comparable to the observed %BMD.

CONCLUSIONS

This is the first model to predict BMD for up to 2 years following two annual doses of ZOL using patients' background characteristics and the early response of TRACP-5b. This model allows us to inform patients at the initial stage of ZOL treatment of their predicted response to treatment.

The forecasting of menstruation based on a state-space modeling of basal body temperature time series

Women's basal body temperature (BBT) shows a periodic pattern that associates with menstrual cycle. Although this fact suggests a possibility that daily BBT time series can be useful for estimating the underlying phase state as well as for predicting the length of current menstrual cycle, little attention has been paid to model BBT time series. In this study, we propose a state-space model that involves the menstrual phase as a latent state variable to explain the daily fluctuation of BBT and the menstruation cycle length. Conditional distributions of the phase are obtained by using sequential Bayesian filtering techniques. A predictive distribution of the next menstruation day can be derived based on this conditional distribution and the model, leading to a novel statistical framework that provides a sequentially updated prediction for upcoming menstruation day. We applied this framework to a real data set of women's BBT and menstruation days and compared prediction accuracy of the proposed method with that of previous methods, showing that the proposed method generally provides a better prediction. Because BBT can be obtained with relatively small cost and effort, the proposed method can be useful for women's health management. Potential extensions of this framework as the basis of modeling and predicting events that are associated with the menstrual cycles are discussed. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Relation between parametric change of the workload and prefrontal cortex activity during a modified version of the 'rock, paper, scissors' task

BACKGROUND/AIMS

Modified rock, paper, scissors (RPS) tasks have previously been used in neuroscience to investigate activity of the prefrontal cortex (PFC). In this study, we investigated hemodynamic changes in the PFC using near-infrared spectroscopy (NIRS) during a modified RPS task in which each subject's successful performance rate was equalized; the workload was increased parametrically in order to reveal the resulting pattern of PFC activation.

METHODS

The subjects were 20 healthy adults. During RPS, the player uses hand gestures to represent rock, paper, and scissors. Rock beats scissors, paper beats rock, and scissors beats paper. In the modified RPS task, the player is instructed to lose intentionally against the computer hand; the computer goes first and the player follows. The interstimulus interval (ISI) level was adjusted with 11 steps. If the level rose, the ISI decreased and the workload increased parametrically. The maximal level (maxLv: the shortest ISI and the biggest workload) in which a subject could perform the task correctly was determined for every subject during rehearsal of the task prior to the experiment. Lowering the level from the maxLv made the task easier. Hemodynamic changes were measured by NIRS over 4 task levels (maxLv-3, maxLv-2, maxLv-1 and maxLv).

RESULTS

The hemodynamic changes in the left lateral PFC and bilateral Brodmann area 6 rose significantly with the increase in workload and presented a linear trend.

CONCLUSION

These results suggest that PFC activation may linearly increase with increased workload during a modified RPS task in which successful performance rates of subjects are equalized.

S-1 as adjuvant chemotherapy for stage III colon cancer: a randomized phase III study (ACTS-CC trial)

BACKGROUND

S-1 is an oral fluoropyrimidine whose antitumor effects have been demonstrated in treating various gastrointestinal cancers, including metastatic colon cancer, when administered as monotherapy or in combination chemotherapy. We conducted a randomized phase III study investigating the efficacy of S-1 as adjuvant chemotherapy for colon cancer by evaluating its noninferiority to tegafur-uracil plus leucovorin (UFT/LV).

PATIENTS AND METHODS

Patients aged 20-80 years with curatively resected stage III colon cancer were randomly assigned to receive S-1 (80-120 mg/day on days 1-28 every 42 days; four courses) or UFT/LV (UFT: 300-600 mg/day and LV: 75 mg/day on days 1-28 every 35 days; five courses). The primary end point was disease-free survival (DFS) at 3 years.

RESULTS

A total of 1518 patients (758 and 760 in the S-1 and UFT/LV group, respectively) were included in the full analysis set. The 3-year DFS rate was 75.5% and 72.5% in the S-1 and UFT/LV group, respectively. The stratified hazard ratio for DFS in the S-1 group compared with the UFT/LV group was 0.85 (95% confidence interval: 0.70-1.03), demonstrating the noninferiority of S-1 (noninferiority stratified log-rank test, P < 0.001). In the subgroup analysis, no significant interactions were identified between the major baseline characteristics and the treatment groups.

CONCLUSION

Adjuvant chemotherapy using S-1 for stage III colon cancer was confirmed to be noninferior in DFS compared with UFT/LV. S-1 could be a new treatment option as adjuvant chemotherapy for colon cancer.

CLINICALTRIALSGOV

NCT00660894.

Standardization of size, shape and internal structure of spinal cord images: comparison of three transformation methods

Functional fluorescence imaging has been widely applied to analyze spatio-temporal patterns of cellular dynamics in the brain and spinal cord. However, it is difficult to integrate spatial information obtained from imaging data in specific regions of interest across multiple samples, due to large variability in the size, shape and internal structure of samples. To solve this problem, we attempted to standardize transversely sectioned spinal cord images focusing on the laminar structure in the gray matter. We employed three standardization methods, the affine transformation (AT), the angle-dependent transformation (ADT) and the combination of these two methods (AT+ADT). The ADT is a novel non-linear transformation method developed in this study to adjust an individual image onto the template image in the polar coordinate system. We next compared the accuracy of these three standardization methods. We evaluated two indices, i.e., the spatial distribution of pixels that are not categorized to any layer and the error ratio by the leave-one-out cross validation method. In this study, we used neuron-specific marker (NeuN)-stained histological images of transversely sectioned cervical spinal cord slices (21 images obtained from 4 rats) to create the standard atlas and also to serve for benchmark tests. We found that the AT+ADT outperformed other two methods, though the accuracy of each method varied depending on the layer. This novel image standardization technique would be applicable to optical recording such as voltage-sensitive dye imaging, and will enable statistical evaluations of neural activation across multiple samples.

Evaluation of the quality of life of lupus erythematosus patients with cutaneous lesions in Japan

The quality of life (QOL) of lupus erythematosus (LE) patients with skin manifestations is impaired, but little is known about Japanese patients. We assessed whether the skin symptoms in LE are associated with the QOL using the Japanese versions of the Skindex-29 and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). In all, 54 LE patients with cutaneous lesions completed the Japanese version of the Skindex-29, and physicians assessed the severity of their eruptions using the CLASI before and after treatment. The QOL of the LE patients was better after the therapeutic intervention using the Skindex-29 questionnaire. We tested several factors for an independent association with the QOL. A significant risk factor for a poor QOL was a female gender in “Functioning” before treatment. In addition, a poor QOL tended to be correlated with a female gender in “Emotions” and older current age in “Symptoms” before treatment, and with a longer duration of SLE in “Functioning” after treatment. In the CLASI analysis, skin manifestation activity in the acute phase correlated with a poor emotional and functional QOL rather than a symptomatic QOL. To the best of our knowledge, this is the first report evaluating the QOL of Japanese LE patients, despite the small cohort.

Fast visible imaging and edge turbulence analysis in QUEST

A fast visible imaging system is installed on the spherical tokamak QUEST to study edge turbulence. The camera uses a complementary metal-oxide semiconductor detector with a maximum resolution of 1024 × 1024 at 7000 frames∕s (fps) and can achieve 775 kfps at a resolution of 128 × 24. In this paper, we present the salient features of the system and its application to study edge turbulence in 8.2 GHz ECRH driven slab plasma, without plasma current. Vertical magnetic field (B(z)) topology is varied with three sets of poloidal field (PF) coils and the variation in the edge turbulence is investigated as a function of the B(z) strength and curvature. Fluctuation amplitude was highest for the shallow PF well. Cross-correlation coefficient shows distinct coherent mode along z direction at the steep density gradient region and it grows with the PF mirror ratio.

A Rho kinase (ROCK) inhibitor, fasudil, prevents matrix metalloproteinase-9-related hemorrhagic transformation in mice treated with tissue plasminogen activator

Thrombolysis with tissue plasminogen activator (tPA) is the only FDA-approved therapy for acute ischemic stroke. However, hemorrhagic transformation, neurotoxicity, and a short treatment time window comprise major limitations for thrombolytic therapy. The purpose of the present study was to investigate whether fasudil, a Rho kinase (ROCK) inhibitor, would prevent tPA-associated hemorrhagic transformation and extend the reperfusion window in an experimental stroke model in mice. Mice subjected to 6-h middle cerebral artery occlusion were treated with delayed tPA alone, with combined tPA plus fasudil, or with a vehicle. We used histological and neurobehavioral measures to assess the effects of the treatment at 18 h and 7 days after the reperfusion. To investigate the mechanism of fasudil's beneficial effects further, we also performed an in vitro study with tPA and fasudil in human brain microvascular endothelial cells. Combination therapy with tPA plus fasudil prevented the development of hemorrhagic transformation, but did not reduce the infarct volumes. These changes significantly reduced mortality and increased locomotor activity at 7 days after the reperfusion. Furthermore, the administration of both drugs prevented injury to the human brain endothelial cells via the reduction of matrix metalloproteinase-9 (MMP-9) activity. These findings indicate that fasudil prevents the hemorrhagic transformation induced by focal cerebral ischemia in mice treated with tPA, at least in part, by inhibiting the increased activity of MMP-9 in endothelial cells.

A broad-spectrum matrix metalloproteinase inhibitor prevents hemorrhagic complications induced by tissue plasminogen activator in mice

Delayed activation of tissue plasminogen activator (tPA) can lead to the disruption of the blood-brain barrier (BBB), resulting in hemorrhagic complications. In the present study, we focused on tight junction proteins (TJPs), occludin, zona occludens (ZO)-1, and claudin-5, which are important structural components of the BBB, and investigated whether inhibition of matrix metalloproteinases (MMPs) provides a protective effect against hemorrhagic complications induced by tPA. We subjected mice to 6-h filamental middle cerebral artery occlusion (MCAO) with vehicle, delayed tPA alone, or combined tPA (10 mg/kg, i.v.) plus GM6001 (100 mg/kg, i.p.), a broad-spectrum MMP inhibitor. We evaluated brain hemoglobin and the expression of MMP-9 and TJPs by immunoblotting. GM6001 significantly reduced tPA-elevated brain hemoglobin, MMP-9, and inhibited the degradation of occludin and ZO-1 induced by tPA, but not claudin-5. Treatment with GM6001 also significantly prevented the decrease in the survival rate and the reduction in locomotor activity caused by tPA at 7 days after ischemia/reperfusion. Furthermore, GM6001 treatment also significantly prevented cell damage, determined by release of lactase dehydrogenase (LDH) activity, and the decrease in transendothelial electrical resistance (TEER) induced by tPA. These findings indicate that GM6001 prevented the hemorrhagic complications and improved the behavioral abnormalities induced by tPA, partly via protection of TJPs. This suggests that GM6001 may be a useful candidate for combination therapy against the hemorrhagic complications induced by tPA.

Forebrain specific heparin-binding epidermal growth factor-like growth factor knockout mice show exacerbated ischemia and reperfusion injury

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a hypoxia-inducible neuroprotective protein that also stimulates proliferation of neuronal precursor cells. In this study, we investigated the possible role of HB-EGF in ischemia and reperfusion injury by measuring the changes in its mRNA expression following focal cerebral ischemia. We also examined neural damage after a middle cerebral artery occlusion (MCAO) and reperfusion in ventral forebrain specific HB-EGF knockout (KO) mice. The levels of HB-EGF mRNA in the cerebral cortex of wild-type (WT) mice were significantly increased 3-24 h after MCAO and reperfusion. Cerebral infraction in HB-EGF KO mice was aggravated at 1 day and 6 days after MCAO and reperfusion compared with WT mice. The number of terminal deoxynucleotidyl transferase (TdT)-mediated dNTP nick end labeling (TUNEL) and an oxidative stress marker, 8-hydroxy-2'-deoxyguanosine (8-OHdG) positive cells, were higher in HB-EGF KO mice than in WT mice. On the other hand, fewer bromodeoxyuridine (BrdU) positive cells were found in the subventricular zone in HB-EGF KO mice compared with WT mice. These results indicate that HB-EGF may play a pivotal role in ischemia and reperfusion injury and that endogenously synthesized HB-EGF is necessary for both the neuroprotective effect and for regulation of cell proliferation in the subventricular zone.

Modulation in concentrative nucleoside transporters-mediated intestinal absorption of mizoribine, an immunosuppressive agent, in lipopolysaccharide-treated rats

The characteristics of intestinal absorption of mizoribine and cephalexin, that are mediated by concentrative nucleoside transporters (CNTs) and PEPT1, respectively, was examined in lipopolysaccharide (LPS)-treated rats. LPS treatment is known to modify the expression of some transporters and induce cholestasis. At 24 h after the LPS treatment, averaged concentrations of IL-6 and total bile acids in plasma were 15-fold and 2-fold that in untreated control rats, respectively, and bile flow rate decreased by 40% of control, indicating the induction of inflammatory and cholestatic states. The oral bioavailability, estimated by urinary excretion percentage of unchanged form, of mizoribine in LPS-treated rats was 1.5-fold higher than that in control rats, whereas the bioavailability of cephalexin remained unchanged. When mizoribine and cephalexin were administered into in-situ jejunum loops, there were no differences in the absorption rates between control and LPS-treated rats. These results indicated that the functional expression of CNT1, CNT2, and PEPT1 were not modulated by LPS treatment. When mizoribine (a CNT1/CNT2 substrate) and gemcitabin (a CNT1 substrate) were administered as a solution dissolved in bile into the intestinal loop, their absorption rates decreased significantly. In contrast, the absorption rate of ribavirin (a CNT2 substrate) remained unchanged. In conclusion, LPS treatment exerted no significant effect on the expression of CNT1 and CNT2 in the intestine. Bile was found to suppress the CNT1-mediated intestinal absorption of mizoribine and gemcitabin. The increased oral bioavailability of mizoribine in LPS-treated rats could be ascribed to the less amount of bile or bile acids in the intestine under cholestatic state of rats.

Detection and visualization method of dynamic state transition for biological spatio-temporal imaging data

In the statistical analysis of functional brain imaging data, regression analysis and cross correlation analysis between time series data on each grid point have been widely used. The results can be graphically represented as an activation map on an anatomical image, but only activation signal, whose temporal pattern resembles the predefined reference function, can be detected. In the present study, we propose a fusion method comprising innovation approach in time series analysis and statistical test. Autoregressive (AR) models were fitted to time series data of each pixel for the range sufficiently before or after the state transition. Then, the remaining time series data were filtered using these AR parameters to obtain its innovation (filter output). The proposed method could extract brain neural activation as a phase transition of dynamics in the system without employing external information such as the reference function. The activation could be detected as temporal transitions of statistical test values. We evaluated this method by applying to optical imaging data obtained from the mammalian brain and the cardiac sino-atrial node (SAN), and demonstrated that our method can precisely detect spatio-temporal activation profiles in the brain or SAN.

The final report of post-marketing surveillance for cetuximab in colorectal cancer in Japan

590

Background: Cetuximab (ERBITUX) was approved in Jul 2008 in Japan with indication for EGFR-positive and unresectable metastatic or refractory colorectal cancer. Post-marketing surveillance is required by Japanese Health Authority to collect, obtain, verify or validate information on the safety, efficacy and quality of medicines. We conducted this surveillance in all patients treated with cetuximab to access in practical use since clinical data on Japanese patients are limited.

Methods: The target number of patients was 1,800. Following adverse drug reactions were investigated: infusion reaction, skin disorders, interstitial lung diseases, electrolyte abnormalities (including hypomagnesemia), heart toxicities, gastrointestinal disorders, thrombosis/embolism, delayed wound healing, and eye disorders.

Results: Between Sep 2008 until Jan 2010, 2,126 pts registered, 2,006 pts were evaluable for safety (safety population), 1,687 pts for efficacy (efficacy population). Of the 2,006 pts, 1,975 pts (98.5%) were EGFR-positive. Patients characteristics: male/female; 1,234/772 (61.5%/38.5%), median age; 64 (range 18-87), site of primary tumor; colon/rectal/others (multiple selection); 1,235/775/3 (61.6%/38.6%/0.2%), PS0/PS1; 1,370/630 (68.3%/31.4%), combination chemotherapy; cetuximab monotherapy/CPT-11/FOLFIRI: 460/1,255/256 (22.9%/62.56%/12.8%). Of the 2,006 pts, 133 pts (6.6%) and 1,869 pts (93.2%) were treated in second-line and in third-line or later treatment, respectively. The adverse drug reactions incidence was 89.9%. Incidence of skin disorders, gastrointestinal disorders, electrolyte abnormality including hypomagnesaemia, and infusion reaction were 83.7%, 23.1%, 11.5%, and 5.7%, respectively. Efficacy result: Of the 1,687 pts, 658 pts (39.0%) were evaluated to be effective. Of the 658 pts, 614 pts (93.3%) experienced skin adverse reactions.

Conclusions: This post-marketing surveillance confirms the safety and efficacy of cetuximab in the Japanese population treated in clinical practice. The outcome of this surveillance with Japanese 2,006 pts would be useful for clinical use of cetuximab.

[Table: see text]

Clinicopathological features in metastatic colorectal cancer patients with KRAS wild type compared with codon 12 and codon 13 mutant: Results from a multicenter, cross-sectional study by the Japan study group of KRAS mutation in colorectal cancer

407

Background: The KRAS mutation mainly located in the codon 12 and 13 indicates unresponsiveness of patients with metastatic colorectal cancer (CRC) to anti-epidermal growth factor receptor (EGFR) antibodies. Many studies have reported that approximately 30%-40% of CRC patients have KRAS mutations. However, the clinicopathological features of KRAS mutant CRC have not been fully clarified, especially in Asian populations. This study aimed to clarify the clinicopathological features of KRAS mutant CRC in comparison with KRAS wild type in large-scale Japanese population.

Methods: The key eligibility criteria included histologically confirmed colorectal adenocarcinoma with adequate tumor samples. Formalin-fixed paraffin-embedded tumor blocks or thinly sliced tumor sections from 389 centers were sent to commercial laboratories. Almost all KRAS point mutations in the codon 12 and 13 were investigated by direct sequencing (96%). The logistic regression analysis was used to estimate the odds ratios (ORs) and compute 95% confidential intervals (CIs).

Results: Of 5,887 registered tumor samples between Oct. 2009 and Mar. 2010, the KRAS testing were performed for 5,790 samples. As of the cut-off date, Sep. 2010, we have successfully determined the KRAS mutational status of 5,732 samples (99%).The median age was 65 years old, and 61% were male. The primary tumor site was right colon, left colon, and rectum in 30, 38, and 32% patients, respectively. The frequency of KRAS mutation was 37.6% (2,155/5,732), of which the 80% (1,714/2,155) mutations were located in codon 12. On logistic regression analysis, female gender (OR=1.212, 95% CI=1.083-1.356), older age > 50 years (OR=1.312, CI=1.056-1.628) and right colon (versus left: OR=2.177, CI=1.905- 2.489; versus rectum: OR=1.500, CI=1.308-1.720) were independent risk factors of KRAS mutant CRC. Clinicopathological features were similar between codon 12 and 13 mutant CRC.

Conclusions: This study disclosed that KRAS mutant CRC was different from KRAS wild type CRC in terms of clinicopathological features.

No significant financial relationships to disclose.

Synthesis and determination of configuration of natural 25-hydroxyvitamin D(3) 26,23-lactone

The four stereoisomers of 25-hydroxyvitamin D(3) 26,23-lactone were synthesized by a stereoselective lactonization method. Natural 25-hydroxyvitamin D(3) 26,23-lactone was produced from 25-hydroxy-[3alpha-(3)H]vitamin D(3) by in vitro incubation of kidney homogenate prepared from vitamin D-supplemented chickens or was isolated from the serum of rats given 1,25-dihydroxyvitamin D(3) and 25-hydroxy-[3alpha-(3)H]vitamin D(3). The four synthetic isomers and the naturally produced 25-hydroxyvitamin D(3) 26,23-lactone were subjected to high-performance liquid chromatography in a system capable of separating the four isomers. The natural lactone comigrated with synthetic (23S,25R)-25-hydroxyvitamin D(3) 26,23-lactone, establishing it as the natural vitamin D(3) metabolite.

Three-beam X-ray rocking curves calculated from computer-simulated pinhole topographs

X-ray rocking curves are reported which have been obtained by fast-Fourier-transforming X-ray amplitudes in three-beam pinhole topographs. The topographs were computer-simulated based on the Takagi-Taupin equation with the condition of spherical-wave X-ray incidence. This is another strategy for calculating three-beam rocking curves, which are usually calculated based on the Ewald-Laue dynamical theory.

Dual oscillator model of the respiratory neuronal network generating quantal slowing of respiratory rhythm

We developed a dual oscillator model to facilitate the understanding of dynamic interactions between the parafacial respiratory group (pFRG) and the preBötzinger complex (preBötC) neurons in the respiratory rhythm generation. Both neuronal groups were modeled as groups of 81 interconnected pacemaker neurons; the bursting cell model described by Butera and others [model 1 in Butera et al. (J Neurophysiol 81:382–397, 1999a)] were used to model the pacemaker neurons. We assumed (1) both pFRG and preBötC networks are rhythm generators, (2) preBötC receives excitatory inputs from pFRG, and pFRG receives inhibitory inputs from preBötC, and (3) persistent Na⁺ current conductance and synaptic current conductances are randomly distributed within each population. Our model could reproduce 1:1 coupling of bursting rhythms between pFRG and preBötC with the characteristic biphasic firing pattern of pFRG neurons, i.e., firings during pre-inspiratory and post-inspiratory phases. Compatible with experimental results, the model predicted the changes in firing pattern of pFRG neurons from biphasic expiratory to monophasic inspiratory, synchronous with preBötC neurons. Quantal slowing, a phenomena of prolonged respiratory period that jumps non-deterministically to integer multiples of the control period, was observed when the excitability of preBötC network decreased while strengths of synaptic connections between the two groups remained unchanged, suggesting that, in contrast to the earlier suggestions (Mellen et al., Neuron 37:821–826, 2003; Wittmeier et al., Proc Natl Acad Sci USA 105(46):18000–18005, 2008), quantal slowing could occur without suppressed or stochastic excitatory synaptic transmission. With a reduced excitability of preBötC network, the breakdown of synchronous bursting of preBötC neurons was predicted by simulation. We suggest that quantal slowing could result from a breakdown of synchronized bursting within the preBötC.

Growth pattern in the muscular layer reflects the biological behaviour of colorectal cancer

OBJECTIVE

To determine the clinical value of evaluating the cancer morphology in muscularis propria (MP) for colorectal cancer (CRC) patients.

METHOD

A total of 994 patients with advanced CRC were reviewed in terms of two distinctive growth patterns in the MP: (i) horizontal spread between the circular and longitudinal muscle layers (H-spread) and (ii) 'streaming' spread between the muscle bundles of the circular muscle layer (S-spread).

RESULTS

The incidence of H-spread (n = 153) and S-spread (n = 150) showed a positive correlation with tumour-node-metastasis (TNM) stage and both exerted a negative impact on postoperative survival. Adverse morphology in the MP (H-spread and/or S-spread) was consistent with a high grade of vascular invasion and budding in the extramural layer, as also with unfavourable fibrotic stromas in the reactive fibrous zone; the 5-year survival rate in patients with such features was 64.2%, which was lower than that in those without (86.5%, P < 0.0001). Multivariate analysis demonstrated that adverse morphology was an independent prognostic determinant, along with T- and N -stage. As the mode of H-spread, perineural invasion in the myenteric plexus was found to be predominant over lymphatic spread on the basis of S100 and CD34 immunostaining, but neural cell adhesion molecule expression, whether on cancer cells or on neural cells, was not significant for this growth pattern.

CONCLUSION

A particular group of CRCs ingeniously utilizes the thin space between muscle fascicles for development in the MP. Although the biological mechanism remains unknown, this distinctive growth pattern could be a useful indicator to identify CRC patients at high risk of recurrence.

Detailed images of asteroid 25143 Itokawa from Hayabusa

Rendezvous of the Japanese spacecraft Hayabusa with the near-Earth asteroid 25143 Itokawa took place during the interval September through November 2005. The onboard camera imaged the solid surface of this tiny asteroid (535 meters by 294 meters by 209 meters) with a spatial resolution of 70 centimeters per pixel, revealing diverse surface morphologies. Unlike previously explored asteroids, the surface of Itokawa reveals both rough and smooth terrains. Craters generally show unclear morphologies. Numerous boulders on Itokawa's surface suggest a rubble-pile structure.

Touchdown of the Hayabusa Spacecraft at the Muses Sea on Itokawa

After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.

cDNA microarray analysis of cancer associated gene expression profiles in malignant peripheral nerve sheath tumours

BACKGROUND

Malignant peripheral nerve sheath tumour (MPNST) is a highly aggressive malignancy that arises within peripheral nerves, and is associated with poor prognosis. Little is known about the underlying biology of MPNST, especially the mechanisms involved in cell proliferation, invasion, or escape from apoptosis.

AIMS

To identify genes differentially expressed in MPNST compared with benign tumours, such as neurofibromas and schwannomas, by means of cDNA microarray analysis.

METHODS

Six MPNST cases and five benign cases (three schwannomas and two neurofibromas) were analysed.

RESULTS

Six genes (keratin 18, survivin, tenascin C, adenosine deaminase, collagen type VIa3, and collagen type VIIa1) were significantly upregulated in MPNST, whereas one gene, insulin-like growth factor binding protein 6, was downregulated in MPNST. Survivin and tenascin C expression was validated by reverse transcription polymerase chain reaction. Immunohistochemistry confirmed upregulation of survivin in MPNST at the protein level in six of eight cases compared with benign tumours. Tenascin C was also expressed at the invasive front and tumorous stroma in all MPNST cases. MPNST cells expressed tenascin C in four of nine cases.

CONCLUSIONS

Survivin and tenascin C may be associated with the malignant potential of MPNST and could be considered as potential therapeutic targets.