Utility of PET/CT in diagnosis, staging, assessment of resectability and metabolic response of pancreatic cancer

Pancreatic cancer is one of the most common gastrointestinal tumors, with its incidence staying at a high level in both the United States and China. However, the overall 5-year survival rate of pancreatic cancer is still extremely low. Surgery remains the only potential chance for long-term survival. Early diagnosis and precise staging are crucial to make proper clinical decision for surgery candidates. Despite advances in diagnostictechnology such as computed tomography(CT)and endoscopic ultrasound,diagnosis,staging and monitoring of the metabolic response remain a challenge for this devastating disease.Positron emission tomography/CT(PET/CT),a relatively novel modality,combines metabolic detection with anatomic information.It has been widely used in oncology and achieves good results in breast cancer,lung cancer and lymphoma.Its utilization in pancreatic cancer has also been widely accepted.However,the value of PET/CT in pancreatic disease is still controversial.Will PET/CT change the treatment strategy for potential surgery candidates?What kind of patients benefits most from this exam?In this review,we focus on the utility of PET/CT in diagnosis,staging,and assessment of resectability of pancreatic cancer.In addition,its ability to monitor metabolic response and recurrence after treatment will be emphasis of discussion.We hope to provide answers to the questions above,which clinicians care most about.

Accuracy of routine multidetector computed tomography to identify arterial variants in patients scheduled for pancreaticoduodenectomy

AIM:To assess the efficacy of cross-sectional multidetector computed tomography(MDCT) imaging without arterialreconstruction to identify aberrant right hepatic artery(RHA) and celiac artery stenosis(CAS) in patients scheduled for pancreaticoduodenectomy.METHODS:Patients with peri-ampullary and pancreatic head tumors who underwent routine preoperative MDCT and subsequent computed tomography(CT) angiography(CTA),conventional angiography or pancreaticoduodenectomy between September 2007 and August 2013 were identified.Retrospective analysis of imaging data was undertaken using CTA,conventional angiographic and surgical findings as the reference standards.The accuracy,sensitivity,specificity,positive predictive value(PPV) and negative predictive value(NPV) of MDCT in evaluation of aberrant RHA and CAS were calculated.RESULTS:A group of 458 patients met the inclusion criteria of this study to detect aberrant RHA,and 181 cases were included to identify CAS.Fifty-four(11.8%) patients were confirmed to have aberrant RHA,while 12(6.6%) patients with CAS were demonstrated.MDCT yielded an accuracy of 98.5%,sensitivity of 96.3% and specificity of 98.8% in the detection of aberrant RHA.The sensitivity,specificity,PPV and NPV of MDCT for detecting CAS were 58.3%,98.2%,70% and 97.1%,respectively.CONCLUSION:Routine MDCT is recommended such that surgeons and radiologists be alerted to the importance of arterial variants on preoperative CT scans in patients scheduled for pancreaticoduodenectomy.

Different Strategies for Preparation of Non-tagged rV270 Protein and Its Efficacy against Yersinia Pestis Challenge

Objective LcrV is an important component for the development of a subunit vaccine against plague.To reduce immunosuppressive activity of LcrV,a recombinant LcrV variant lacking amino acids 271 to 326 （rV270） was prepared by different methods in this study.Methods A new strategy that produced non-tagged or authentic rV270 protein was designed by insertion of rV270-thrombin-hexahistidine fusion gene into the vector pET24a,or by insertion of hexahistidine-enterokinase-rV270 or hexahistitine-factor Xa-rV270 fusion gene into the vector pET32a.After Co2＋ affinity chromatography,a purification strategy was developed by cleavage of His tag on column,following Sephacryl S-200HR column filtration chromatography.Results Removal of His tag by thrombin,enterokinase and factor Xa displayed a yield of 99.5%,32.4% and 15.3%,respectively.Following Sephacryl S-200HR column filtration chromatography,above 97% purity of rV270 protein was obtained.Purified rV270 that was adsorbed to 25% （v/v） Al（OH）3 adjuvant in phosphate-buffered saline （PBS） induced very high titers of antibody to rV270 in BALB/c mice and protected them （100% survival） against subcutaneous challenge with 106 CFU of Y.pestis virulent strain 141.Conclusion The completely authentic rV270 protein can be prepared by using enterokinase or factor Xa,but they exhibited extremely low cleavage activity to the corresponding recognition site.Thrombin cleavage is an efficient strategy to prepare non-tagged rV270 protein and can be easily operated in a large scale due to its relatively low cost and high cleavage efficacy.The recombinant rV270 can be used as a key component to develop a subunit vaccine of plague.

Multidimensional amphibian diversity and community structure along a 2600 m elevational gradient on the eastern margin of the Qinghai-Tibetan Plateau

Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly understood.Here,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern China.We also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community structure.Results showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with elevation.Phylogenetic net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive exclusion.Overall,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with elevation.This study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.

Single-nucleotide polymorphisms based genetic risk score in the prediction of pancreatic cancer risk

BACKGROUND Disease-related single nucleotide polymorphisms(SNPs)based genetic risk score(GRS)has been proven to provide independent inherited risk other than family history in multiple cancer types.AIM To evaluate the potential of GRS in the prediction of pancreatic cancer risk.METHODS In this case-control study(254 cases and 1200 controls),we aimed to evaluate the association between GRS and pancreatic ductal adenocarcinoma(PDAC)risk in the Chinese population.The GRS was calculated based on the genotype information of 18 PDAC-related SNPs for each study subject(personal genotyping information of the SNPs)and was weighted by external odd ratios(ORs).RESULTS GRS was significantly different in cases and controls(1.96±3.84 in PDACs vs 1.09±0.94 in controls,P<0.0001).Logistic regression revealed GRS to be associated with PDAC risk[OR=1.23,95%confidence interval(CI):1.13-1.34,P<0.0001].GRS remained significantly associated with PDAC(OR=1.36,95%CI:1.06-1.74,P=0.015)after adjusting for age and sex.Further analysis revealed an association of increased risk for PDAC with higher GRS.Compared with low GRS(<1.0),subjects with high GRS(2.0)were 99%more likely to have PDAC(OR:1.99,95%CI:1.30-3.04,P=0.002).Participants with intermediate GRS(1.0-1.9)were 39%more likely to have PDAC(OR:1.39,95%CI:1.03-1.84,P=0.031).A positive trend was observed(P trend=0.0006).CONCLUSION GRS based on PDAC-associated SNPs could provide independent information on PDAC risk and may be used to predict a high risk PDAC population.

A new species of the genus Kurixalus(Anura:Rhacophoridae)from Sichuan Province,southwestern China

Combining morphological and molecular data,we describe a new amphibian species of the genus Kurixalus Ye,Fei,&Dubois,1999 from the Qionglai Mountain within the western margin of the Sichuan Basin in China.Kurixalus qionglaiensis sp.nov.can be diagnosed based on a combination of the following morphological characters:medium-sized within genus(snout-vent length(SVL)in males 28.9−33.3 mm);tympanum distinct,subequal to half of eye diameter;snout pointed,prominence on tip;iris golden with brown spots;slight nuptial pad on first finger in males;background coloration of dorsal surface brown,lateral body and femoral yellow;white,dark brown edged triangular markings on cheek;chin shaded dark brown;pair of large symmetrical dark patches on chest;belly clouded brown and scattered black spots;toes moderately webbed,formulaⅠ2-2Ⅱ1.5-2.5Ⅲ1.5-2.5Ⅳ2.5-1.5Ⅴ;tibia length slightly shorter than half of SVL,tibiotarsal articulation reaching posterior border of eye;single external vocal sac present.Based on the 16S rRNA gene,the genetic distance between the new species and its sister taxon K.idiootocus(Kuramoto&Wang,1987)was 4%.At present,the new species is known only from a single location at an elevation of~600 m in Pingle Town,Qionglai City,Sichuan,southwestern China.This location can represent a new northernmost geographical limit of the genus Kurixalus.

The effect of different number of diffusion gradients on SNR of diffusion tensor-derived measurement maps

Diffusion tensor imaging (DTI) is mainly applied to white matter fiber tracking in human brain, but there is still a debate on how many diffusion gradient directions should be used to get the best results. In this paper, the performance of 7 protocols corresponding to 6, 9, 12, 15, 20, 25, and 30 noncollinear number of diffusion gradi-ent directions (NDGD) were discussed by com-paring signal-noise ratio (SNR) of tensor- de-rived measurement maps and fractional ani-sotropy (FA) values. All DTI data (eight healthy volunteers) were downloaded from the website of Johns Hopkins Medical Institute Laboratory of Brain Anatomi-cal MRI with permission. FA, apparent diffusion constant mean (ADC-mean), the largest eigen-value (LEV), and eigenvector orientation (EVO) maps associated with LEV of all subjects were calculated derived from tensor in the 7 proto-cols via DTI Studio. A method to estimate the variance was presented to calculate SNR of these tensor-derived maps. Mean &amp;amp;#177;standard deviation of the SNR and FA values within re-gion of interest (ROI) selected in the white mat-ter were compared among the 7 protocols. The SNR were improved significantly with NDGD increasing from 6 to 20 (P&amp;amp;lt;0.05). From 20 to 30, SNR were improved significantly for LEV and EVO maps (P&amp;amp;lt;0.05), but no significant dif-ferences for FA and ADC-mean maps (P&amp;amp;gt;0.05). There were no significant variances in FA val-ues within ROI between any two protocols (P&amp;amp;gt;0.05). The SNR could be improved with NDGD in-creasing, but an optimum protocol is needed because of clinical limitations.

Bilateral chylothorax following left supraclavicular lymph node dissection for breast cancer: one case report and literature review

Chylothorax is a rare complication of neck dissection, and bilateral chylothorax is even rarer. However, both are potentially serious and sometimes life-threatening, especially those that are associated with left neck dissection for head and neck neoplasms. We report one case of bilateral chylothorax following left supraclavicular dissection for breast cancer. This case was treated successfully with a new conservative management approach.

KCNQ Channels in the Mesolimbic Reward Circuit Regulate Nociception in Chronic Pain in Mice

Mesocorticolimbic dopaminergic(DA) neurons have been implicated in regulating nociception in chronic pain, yet the mechanisms are barely understood. Here, we found that chronic constructive injury(CCI) in mice increased the firing activity and decreased the KCNQ channel-mediated M-currents in ventral tegmental area(VTA) DA neurons projecting to the nucleus accumbens(NAc). Chemogenetic inhibition of the VTA-to-NAc DA neurons alleviated CCI-induced thermal nociception.Opposite changes in the firing activity and M-currents were recorded in VTA DA neurons projecting to the medial prefrontal cortex(mPFC) but did not affect nociception. In addition, intra-VTA injection of retigabine, a KCNQ opener, while reversing the changes of the VTA-to-NAc DA neurons, alleviated CCI-induced nociception, and this was abolished by injecting exogenous BDNF into the NAc.Taken together, these findings highlight a vital role of KCNQ channel-mediated modulation of mesolimbic DA activity in regulating thermal nociception in the chronic pain state.

Retinal Vascular Morphological Changes in Patients with Extremely Severe Obstructive Sleep Apnea Syndrome

Background：Obstructive sleep apnea syndrome （OSAS） has been shown to generate hypertension and endothelial dysfunction.Retinal vessel is the only vessel that can be observed directly and noninvasively;retinal vascular abnormalities can serve as a predictive marker for the occurrence,clinical course,and prognosis of cardiovascular and cerebrovascular diseases.The objective of this study was to identify the effect of OSAS severity on the morphological changes of retinal vessels.Methods：Adult patients complained of snoring were included in this study.The patients＆#39; general information,polysomnography,and fundus photography parameters including central retinal artery equivalent （CRAE）,central retinal vein equivalent （CRVE）,and arteriole-to-venule ratio （AVR） were collected.Patients were divided into four groups according to their apnea-hypopnea index （AHI） results：Group Ⅰ,AHI ≤5/h;Group ll,5/h 〈 AHI ≤30/h;Group Ⅲll,30/h 〈 AHI ≤60/h;and Group Ⅳ,AHI 〉60/h.Results：A total of 133 patients were included in this study with 111 males （83.5%） and 22 females （16.5%）.Mean age was 41.6 ± 9.9 years,and the mean body mass index was 28.1 ± 4.0 kg/m2.AHI ranged between 0 and 130.8/h with a mean of 39.l ± 30.7/h.There were 24,34,35,and 40 patients in Group Ⅰ,Group Ⅱ,Group Ⅲ,and Group Ⅳ,respectively.Significant differences were found for AHI （F =388.368,P 〈 0.001）,minimal pulse oxygen saturation （F-91.902,P 〈 0.001）,and arousal index （F =31.014,P 〈 0.001） among four groups;no significant differences were found for CRAE （F=0.460,P =0.599） and CRVE （F =0.404,P =0.586） among groups;there were significant differences for AVR between Group l and Group Ⅳ （63.6 ± 5.1% vs.67.2 ± 5.5%,P =0.010） Group Ⅱ and Group Ⅳ （64.5 ± 6.0% vs.67.2 ± 5.5%,P =0.030）,and Group ll and Group Ⅳ （64.7 ± 4.1% vs.67.2 ± 5.5%,P=0.043）.A main group-by-AHI effect was found on the AVR：patients with higher AHI showed higher AVR results （r =0.225,P =0.009）.Multivariate logistic regression analysis was used for multi-variable factors.A group-by-age effect was found on the AVR：younger patients showed higher AVR results （β =-0.001,P =0.020）.Conclusions：This study indicated that increased AVR of retinal vessel can be observed in extremely severe OSAS patients.For patients with OSAS,retinal vascular abnormalities may become an early indication for further cardiovascular abnormalities.

A new species of Anastatus(Hymenoptera:Eulpelmidae) from China,parasitizing eggs of Lycorma delicatula(Homoptera:Fulgoridae)

A new species of Anastatus Motschulsky, 1859 （Hymenoptera： Eupelmidae）, A. orientalis Yang ＆ Choi, sp. nov. is described from China. It is a solitary endo-parasitoid in egg of the spotted lanternfly, Lycorma delicatula （White） （Homoptera： Fulgoridae）, which causes damages to many ornamental and fruit trees in China. The brief biology of the new parasitoid is also mentioned. The new species has high potential as a biocontrol agent for suppression of the pest because of its parasitism rates of egg masses 30.4% and of eggs 40.2% respectively with sex ratio of female to male 1.9：1.0, as well as the relative easiness for mass rearing. The detailed feature characters and photos of the new species are supplied. Meanwhile, a key to distinguish the present new species from the other close two （A. japonicus and A. bifasciatus） in the genus is provided. Type specimens are deposited in the Insect Museum, Chinese Academy of Forestry, Beijing, China.

A Direct Parametric Approach to Spacecraft Attitude Tracking Control

Through the direct parameter approach, a solution for spacecraft attitude tracking is presented. First of all, the spacecraft attitude tracking control model is built up by the error equation of the second-order nonlinear quaternion-based attitude system. Based on the control model, a suitable controller is designed by the direct parameter approach. Compared with other control strategies, the direct parameter approach can offer all degrees of freedom for the controller to satisfy the requirements for system properties and turn the original nonlinear system into closed-loop linear system. Furthermore, this paper optimizes the controller according to the robustness, limitation of controller output and closed-loop eigenvalue sensitivity. Putting the controller into the original system, the state response of the closed-loop system and the output of controller are plotted in Matlab to verify the availability and robustness of the controller. Therefore, the controlled spacecraft can achieve the goal of tracking on the mobile target with the external disturbance torque.

Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells:3-dimensional collagen matrix model

Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes,possibly due to proliferation of vascular endothelial cells(ECs) induced by mucoepidermoid carcinoma cells(MCCs) in their three-dimensional(3D) microenvironment.To date,no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model.In this context,the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs(MCMECs) conditioned by the microenvironment in the 3D collagen matrix model.We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs,and characteristics of tubule-like structures(TLSs) formed by induced MCMECs or non-induced MCMECs.The assessment parameters involved the growth curve,the length,the outer and inner diameters,and the wall thickness of the TLSs,and the cell cycle.Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model.A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture(t=5.00,P=0.001).The outer and inner diameters(t1=5.549,P1=0.000;t2=10.663,P2=0.000) and lengths(t=18.035,P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group.The TLSs were formed at the earlier time in the induction group compared with the control group.It is concluded that MCCs promote growth and migration of MCMECs,and formation of the TLSs.The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma.