Germline promoter hypermethylation of tumor suppressor genes in gastric cancer

AIM: To explore germline hypermethylation of the tumor suppressor genes MLH1, CDH1 and P16INK4a in suspected cases of hereditary gastric cancer (GC). METHODS: A group of 140 Chinese GC patients in whom the primary cancer had developed before the age of 60 or who had a familial history of cancer were screened for germline hypermethylation of the MLH1, CDH1 and P16INK4a tumor suppressor genes. GenomicDNA was extracted from peripheral blood leukocytes and modified by sodium bisulfite. The treated DNA was then subjected to bisulfi te DNA sequencing for a specif ic region of the MLH1 promoter. The methylation status of CDH1 or P16INK4a was assayed using methylation-specif ic PCR. Clonal bisulf ite allelic sequencing in positive samples was performed to obtain a comprehensive analysis of the CpG island methylation status of these promoter regions. RESULTS: Methylation of the MLH1 gene promoter was detected in the peripheral blood DNA of only 1/140 (0.7%) of the GC patient group. However, this methylation pattern was mosaic rather than the allelic pattern which has previously been reported for MLH1 in hereditary non-polyposis colorectal cancer (HNPCC) patients. We found that 10% of the MLH1 alleles in the peripheral blood DNA of this patient were methylated, consistent with 20% of cells having one methylated allele. No germline promoter methylation of the CDH1 or P16INK4a genes was detected. CONCLUSION: Mosaic germline epimutation of the MLH1 gene is present in suspected hereditary GC patients in China but at a very low level. Germline epimutation of the CDH1 or P16INK4a gene is not a frequent event.

Novel CDH1 germline mutations identified in Chinese gastric cancer patients

AIM:To give a comprehensive report of E-cadheringene (CDH1) variations in a population at a high risk for gastric cancer (GC).METHODS:The samples consisted of 178 men and 58 women with a mean age of 62.3 ± 9.4 years and an age range of 30-84 years.A total of 240 cancerfree controls were recruited (mean age of 61.8 ± 10.1 years,age range of 26-82 years).Samples were screened for CDH1 germline mutations by high-resolution melting analysis or directly sequencing.Luciferase reporter assay,RNA splicing assay and bioinformatic analysis were used to evaluate the effect of mutations.RESULTS:Four novel CDH1 sequence alterations were identified in GC patients including a G>T transition 49 bp before the start codon;a three-nucleotide deletion,c.44_46del TGC;one missense mutation,c.604G>A (V202I);and one variation in the intron,c.1320+7A>G.In addition,polymorphism frequencies were observed for CDH1-164delT,-161C>A,-73A>C,c.48+6C>T,c.48+62_48+63delinsCGTGCCCCAGCCC,c.894C>T (A298A),c.1224G>A (A408A),c.1888C>G (L630V),c.2076T>C (A692A),and c.2253C>T (N751N) which is similar to the data reported in http://www.ncbi.nlm.nih.gov/projects/SNP/.RNA splicing analysis suggested that the c.1320+7A>G and c.1224G>A variations did not affect exon splicing ability.Luciferase reporter assay demonstrated that the c.-49T variation might be helpful for E-cadherin transcription,though the increase in transcription activity is limited (only 33%).SIFT score and PolyPhen analysis both demonstrated that the L630V missense mutation probably damages protein function,while the V202I variant does not.CONCLUSION:This study reveals novel mutations in sporadic GC patients which had been poorly investigated for susceptibility genes.

Effects of ephedrine on expression of Nogo-A and synaptophysin in neonatal rats following hypoxic-ischemic brain damage

BACKGROUND： Central nervous system axons regenerate poorly following neonatal hypoxic-ischemic brain damage （HIBD）, partly due to inhibitors, such as Nogo-A. Very few studies have addressed the regulation of Nogo-A in neonatal rats following HIBD. However, numerous studies have shown that ephedrine accelerates neuronal remodeling and promotes recovery of neural function in neonatal rats following HIBD. OBJECTIVE： To investigate the effects of ephedrine on expression of Nogo-A and synaptophysin in brain tissues of neonatal rats following HIBD. DESIGN, TIME AND SETTING： A completely randomized, controlled study was performed at the Immunohistochemistry Laboratory of the Research Institute of Pediatrics, Children＇s Hospital of Chongqing Medical University from August 2008 to March 2009. MATERIALS： Ephedrine hydrochloride （Chifeng Pharmaceutical Group, China）, rabbit anti-Nogo-A polyclonal antibody （Abcam, UK）, and rabbit anti-synaptophysin polyclonal antibody （Lab Vision, USA） were used in this study. METHODS： A total of 96 healthy, neonatal, Sprague Dawley rats were randomly assigned to three groups （n = 32）： sham operation, HIBD, and ephedrine. The HIBD model was established by permanent occlusion of the left common carotid artery, followed by 2 hours of hypoxia （8% oxygen and 92% nitrogen）. In the sham operation group, the left common carotid artery was exposed, but was not ligated or subjected to hypoxia. Rats in the ephedrine group were intraperitoneally injected with ephedrine immediately following HIBD, with 1.5 mg/kg each time. Rats in the sham operation and HIBD groups were injected with an equal volume of saline. All neonatal rats were treated once daily for 7 days. MAIN OUTCOME MEASURES： Histopathological damage to the cortex and hippocampus was determined by hematoxylin-eosin staining. Expression of Nogo-A and synaptophysin was detected using immunohistochemical staining. RESULTS： Neuronal degeneration and edema were observed in the hypoxJc-Jschemic cortex and hippocampus by hematoxylin-eosin staining. Compared with the sham operation group, the levels of Nogo-A significantly increased in the HIBD group at various time points （P 〈 0.01）. Nogo-A expression was significantly reduced in the ephedrine group compared with the HIBD group （P 〈 0.01）. Synaptophysin expression was significantly decreased in the hypoxic-ischemJc cortex, compared with the sham operation group （P 〈 0.01）. Synaptophysin levels were significantly increased in the ephedrine group, compared with the HIBD group （P 〈 0.01）. CONCLUSION： Altered Nogo-A expression was associated with inversely altered synaptophysin expression. The use of ephedrine normalized expression levels of Nogo-A and synaptophysin following HIBD.

Optimal compatible doses and effects of ephedrine and naloxone on neural plasticity in cerebral ischemia/reperfusion rats

BACKGROUND： Ephedrine promotes neural plasticity in rats following cerebral ischemia/reperfusion injury. Ephedrine has been combined with naloxone in some studies, and it has been confirmed that their combination has synergistic effects on increasing neural plasticity following cerebral ischemia/reperfusion injury. OBJECTIVE： To investigate the effects of ephedrine combined with various doses of naloxone on neural plasticity and to find an optimal dose of naloxone in rats after cerebral ischemia/reperfusion injury by analyzing growth associated protein-43 （GAP-43）, synaptophysin and β-endorphin expression in the hippocampal CA3 area. DESIGN, TIME AND SETTING： This immunohistochemical, randomized, controlled, animal experiment was performed at the Chongqing Research Institute of Pediatrics, China from September 2007 to June 2008. MATERIALS： Ephedrine hydrochloride injection and naloxone hydrochloride injection were respectively purchased from Shandong Lvliang Pharmaceutical Factory, China and Sichuan Jingwei Pharmaceutical Co., Ltd., China. A total of 192 healthy adult Sprague Dawley rats were used to establish models of left middle cerebral artery occlusion using the suture occlusion method. METHODS： At 2 hours following cerebral ischemia, the rats were intraperitoneally injected with 1.5 mg/kg/d ephedrine （ephedrine group）, with 0.1, 0.2, or 0.3 mg/kg/d naloxone （low, moderate and high doses of naloxone groups）, with 1.5 mg/kg/d ephedrine ＋ 0.1, 0.2, or 0.3 mg/kg/d naloxone （ephedrine ＋ low, moderate and high doses of naloxone groups）, and with 0.5 mL saline （model group）, respectively. MAIN OUTCOME MEASURES： GAP-43, synaptophysin and β -endorphin expression were detected in the hippocampal CA3 area using immunohistochemistry 1-4 weeks after surgery. Sensorimotor integration in rats was assessed using the beam walking test. RESULTS： GAP-43 and synaptophysin expression was greater in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group. GAP-43 and synaptophysin expression was greatest in the ephedrine ＋ high dose of naloxone group at 2 and 3 weeks alter surgery. β -endorphin expression was significantly lower in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group （P 〈 0.05）. β -endorphin expression was persistently low in the ephedrine ＋ high dose of naloxone group. At 1-3 weeks after surgery, the beam walking test score was significantly higher in the ephedrine group and ephedrine ＋ various doses of naloxone groups than in the model group （P 〈 0.05）. The score was higher in the ephedrine ＋ moderate and high doses of naloxone groups than in the ephedrine group （P 〈 0.05）. Moreover, the score was increased as the dose of naloxone increased in the ephedrine ＋ various doses of naloxone groups. CONCLUSION： Ephedrine promotes GAP-43 and synaptophysin expression, inhibits /3 -endorphin expression in the hippocampal CA3 area, and improves motor function in rats following cerebral ischemia/reperfusion injury. Naloxone does not have the above-mentioned effects. During combined treatment with ephedrine and naloxone, however, the above-described effects are enhanced with an increased dose of naloxone. The combination of ephedrine （1.5 mg/kg/d） and naloxone （0.3 mg/kg/d） can produce optimal therapeutic efficacy in treatment of cerebral ischemic injury.

NVM Storage in IoT Devices:Opportunities and Challenges

Edge storage stores the data directly at the data collection point,and does not need to transmit the collected data to the storage central server through the network.It is a critical technology that supports applications such as edge computing and 5G network applications,with lower network communication overhead,lower interaction delay and lower bandwidth cost.However,with the explosion of data and higher real-time requirements,the traditional Internet of Things(IoT)storage architecture cannot meet the requirements of low latency and large capacity.Non-volatile memory(NVM)presents new possibilities regarding this aspect.This paper classifies the different storage architectures based on NVM and compares the system goals,architectures,features,and limitations to explore new research opportunities.Moreover,the existing solutions to reduce the write latency and energy consumption and increase the lifetime of NVM IoT storage devices are analyzed.Furthermore,we discuss the security and privacy issues of IoT devices and compare the mainstream solutions.Finally,we present the opportunities and challenges of building IoT storage systems based on NVM.

660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment

Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hy- poxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efficiencies are relatively low. Red or near-infrared light from 600-1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the treatment of hypoxic-ischemic brain damage. In this study, the migra- tion and colonization of cultured bone marrow mesenchymal stem cells on primary neurons after oxygen-glucose deprivation were detected using Transwell assay. The results showed that, after a 40-hour irradiation under red light-emitting diodes at 660 nm and 60 mW/cmz, an increasing number of green fluorescence-labeled bone marrow mesenchymal stem cells migrated towards hypoxic-ischemic damaged primary neurons. Meanwhile, neonatal rats with hypoxic-ischemic brain damage were given an intraperitoneal injection of 1 x 106 bone marrow mesenchymal stem cells, followed by irradiation under red light-emitting diodes at 660 nm and 60 mW/cm2 for 7 successive days. Shuttle box test results showed that, after phototherapy and bone marrow mesenchymal stem cell transplantation, the active avoidance response rate of hypoxic-ischemic brain damage rats was significantly increased, which was higher than that after bone marrow mesenchymal stem cell transplantation alone. Experimental findings indicate that 660 nm red light emitting diode irradiation promotes cells, thereby enhancing the contribution ic-ischemic brain damage. the migration of bone marrow mesenchymal stem of cell transplantation in the treatment of hypox-

Side effects of different doses of ephedrine in rats with cerebral ischemia/reperfusion injury

Ephedrine has a protective effect against cerebral ischemia,but its side effects limit its clinical application.Results from a previous study showed that 1.5 mg/kg per day ephedrine can promote motion recovery in rats following cerebral ischemia/reperfusion without significant side effects.In the present study,ephedrine at doses of 3.0,2.5 and 2.0 mg/kg was used to treat rats with cerebral ischemia/reperfusion and the effects of ephedrine on the heart,liver,kidney and cerebrum were observed.Results showed that the blood pressure of rats with cerebral ischemia/reperfusion injury following ephedrine treatment was lower than in rats that recovered naturally from cerebral ischemia/reperfusion,but the pressure decreased with increasing doses of ephedrine.In addition,serum aspartate transaminase,alkaline phosphatase and creatinine concentration in rats with cerebral ischemia/reperfusion injury following ephedrine treatment were greater than in rats that recovered naturally from cerebral ischemia/reperfusion.The concentrations of these enzymes were decreased with increasing doses of ephedrine.Ephedrine-treated rats displayed hyperemia,degeneration and edema in the cerebrum,liver,heart and kidney.Results demonstrated that ephedrine exhibited side effects on the cerebrum,heart,liver and kidney in rats following cerebral ischemia/reperfusion in a dose-dependent manner.

GFCache: A Greedy Failure Cache Considering Failure Recency and Failure Frequency for an Erasure-Coded Storage System

In the big data era,data unavailability,either temporary or permanent,becomes a normal occurrence on a daily basis.Unlike the permanent data failure,which is fixed through a background job,temporarily unavailable data is recovered on-the-fly to serve the ongoing read request.However,those newly revived data is discarded after serving the request,due to the assumption that data experiencing temporary failures could come back alive later.Such disposal of failure data prevents the sharing of failure information among clients,and leads to many unnecessary data recovery processes,(e.g.caused by either recurring unavailability of a data or multiple data failures in one stripe),thereby straining system performance.To this end,this paper proposes GFCache to cache corrupted data for the dual purposes of failure information sharing and eliminating unnecessary data recovery processes.GFCache employs a greedy caching approach of opportunism to promote not only the failed data,but also sequential failure-likely data in the same stripe.Additionally,GFCache includes a FARC(Failure ARC)catch replacement algorithm,which features a balanced consideration of failure recency,frequency to accommodate data corruption with good hit ratio.The stored data in GFCache is able to support fast read of the normal data access.Furthermore,since GFCache is a generic failure cache,it can be used anywhere erasure coding is deployed with any specific coding schemes and parameters.Evaluations show that GFCache achieves good hit ratio with our sophisticated caching algorithm and manages to significantly boost system performance by reducing unnecessary data recoveries with vulnerable data in the cache.

CLEC:Combination Locality Based Erasure Code for Permissioned Blockchain Storage

Building a new decentralized domain name system based on blockchain technology is helping to solve problems,such as load imbalance and over-dependence on the trust of the central node.However,in the existing blockchain storage system,the storage overhead is very high due to its fullreplication data storage mechanism.The total storage consumption for each block is up to O(n)with n nodes.Erasure code applied to blockchains can significantly reduce the storage overhead,but also greatly lower the read performance.In this study,we propose a novel coding scheme for blockchain storage,Combination Locality based Erasure Code for Permissioned blockchain storage(CLEC).CLEC uses erasure code,parity locality,and topology locality in blockchain storage,greatly reducing reading latency and repair time.In CLEC,the storage consumption per block can be reduced to O(1),and the repair penalty can also be lowered to O(1).Experiments in an open-source permissioned blockchain Tendermint show that CLEC has a maximum repair speed of 6 times and a read speed of nearly 1.7 times with storage overhead of only 1.17 times compared to the current work,a great improvement in reading performance and repair performance with slightly increased storage overhead via implementation.

Effects of exogenous ganglioside-1 on learning and memory in a neonatal rat model of hypoxia-ischemia brain injury

BACKGROUND： Exogenous ganglioside-1 （GM1） can cross the blood-brain barrier and play a protective role against hypoxia-ischemia-induced brain damage. OBJECTIVE： To examine the possible mechanisms of exogenous GM1 protection in hypoxia-ischemia-induced brain damage in a neonatal rat model by measuring changes in brain mass, pathological morphology, growth-associated protein-43 expression, and neurobehavioral manifestations. DESIGN, TIME AND SETTING： A randomized block-design study was performed at the Immunohistochemistry Laboratory of the Pediatric Research Institute, Children＇s Hospital of Chongqing Medical University from August 2005 to August 2006. MATERIALS： A total of 36 neonatal, 7-day-old, Sprague Dawley rats were used in this experiment. The hypoxia-ischemia-induced brain damage model was established by permanently occluding the right carotid artery, followed by oxygen inhalation at a low concentration （8% O2, 92% N2） for 2 hours, METHODS： All rats were randomly divided into the following groups： GMI, model, and sham operation, with 12 rats each group. Rats in the GM 1 and model groups received hypoxic/ischemic-induced brain damage. Rats in the GM1 group received injections of GM1 （i.p., 20 mg/kg） at 0, 24, 48, 72, 96, 120, and 144 hours following models established, and rats in the model group were administered （i.p.） the same amount of saline. The right carotid artery was separated, but not ligated, in the sham operation group rats. MAIN OUTCOME MEASURES： At 1 week after surgery, expression of growth-associated protein-43, a marker of neural development and plasticity, was detected in the hippocampal CA3 region by immunohistochemistry. Brain mass was measured, and the pathological morphology was observed. At 4 weeks after surgery, behavioral changes in the remaining rats were tested by Morris water maze, and growth-associated protein-43 expression was measured. RESULTS： （1） In the GMI and sham operation groups, growth-associated protein-43 expression was greater in the hippocampal CA3 region compared to the model group 1 week after surgery （P 〈 0.05）. In all three groups, brain weight of the right hemisphere was significantly less than the left hemisphere, in particular in the model group （P 〈 0.05）. In the GMI group, the weight difference between two hemispheres, as well as the extent of damage in the right hemisphere, was less than the model group （P 〈 0.01 ）. In the sham operation Uoup, brain tissue consisted of integrated structures and ordered cells. In the model group, the cerebral cortex layers of the right hemisphere were not defined, neurons were damaged, and neurons were disarranged in the hippocampal area. In the GM1 group, neurons were dense in the right cerebral cortex and hippocampal area, with no significant change in glial proliferation. （2） The average time of escape latency in the GM1 group was shortened 4 weeks alter surgery, and significantly less than the model group （P 〈 0.05）. In addition, the frequency platform passing in the GMI group was significantly greater than the model group （P 〈 0.01）. CONCLUSION： Exogenous GM1 may reduce brain injury and improve learning and memory in hypoxia-ischemia-induced brain damage rats. This protection may be associated with increased growth-associated protein-43 expression, which is involved in neuronal remodeling processes.

Task-Based Resource Allocation Bid in Edge Computing Micro Datacenter

Edge computing attracts online service providers(SP)to offload services to edge computing micro datacenters that are close to end users.Such offloads reduce packet-loss rates,delays and delay jitter when responding to service requests.Simultaneously,edge computing resource providers(RP)are concerned with maximizing incomes by allocating limited resources to SPs.Most works on this topic make a simplified assumption that each SP has a fixed demand;however,in reality,SPs themselves may have multiple taskoffloading alternatives.Thus,their demands could be flexibly changed,which could support finer-grained allocations and further improve the incomes for RPs.Here,we propose a novel resource bidding mechanism for the RP in which each SP bids resources based on the demand of a single task(task-based)rather than the whole service(servicebased)and then the RP allocates resources to these tasks with following the resource constraints at edge servers and the sequential rule of task-offloading to guarantee the interest of SPs.We set the incomes of the RP as our optimization target and then formulate the resource allocation problem.Two typical greedy algorithms are adopted to solve this problem and analyze the performance differences using two different bidding methods.Comprehensive results show that our proposal optimizes resource utilization and improves the RP’s incomes when resources in the edge computing datacenter are limited.

Weak Greedy Routing over Graph Embedding for Wireless Sensor Networks

In this paper we classify the greedy routing in sensor networks into two categories, strong greedy routing and weak greedy routing. Most existing work mainly focuses on weak greedy routing over geographic location network or strong greedy routing over greedy embedding network. It is a difficult job and needs much cost to obtain geographic location or greedy embedding of the network. We propose a light-weight Tree-based graph embedding (TGE) for sensor networks. Over the TGE, we design a weak greedy routing protocol, TGR. TGR can archive good performance on path stretch factor and load balance factor.

Design and application of new storage systems

A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Things.Storage stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.

A multicenter retrospective cohort study of ketogenic diet therapy in 481 children with infantile spasms

Background:Ketogenic diet(KD)therapy is one of the main treatments for drug-resistant epilepsy.However,the KD therapy has been applied in only a small number of infantile spasm cases.In this large multicenter study,we investigated the efficacy of KD therapy in the treatment of infantile spasms.Methods:In this retrospective,multicenter cohort study,clinical data from main epilepsy centers were analyzed.Patients were classified into different groups according to age,type of drug and whether glucocorticoid was used before initiation of KD.Results:From October 2014 to March 2020,481 patients(308 males and 173 females)with infantile spasms were treated with the KD therapy.The age of the patients ranged from 2 months to 20 years,with a mean age of 1 year and 10 months.The number of anti-seizure medications(ASMs)used before KD initiation ranged 0-6,with a median of 3.In different time from initiation(1,3,6,and 12 months),the rates of seizure freedom after KD were 6.9,11.6;16.0 and 16.8%,respectively(x^(2)=27.1772,P<0.0001).There was a significant difference in the rate of seizure freedom between 3 months and 1 month(x^(2)=6.5498,P=0.0105)groups,and 6 months and 3 months(x^(2)=3.8478,P=0.0498)groups,but not between 12 months and 6 months(x^(2)=0.1212,P=0.7278)groups.The rates of effectiveness were 44.7;62.8,49.1 and 32.0%(x^(2)=93.2674,P<0.0001),respectively.The retention rates were 94.0,82.5,55.7 and 33.1%(x^(2)=483.7551,P<0.0001),correspondingly.The rate of effectiveness and the retention rate of KD were significantly different among the 1,3,6 and 12 months.KD treatment was the first choice in 25 patients(5.2%),55 patients(11.4%)started KD after the failure of the first ASM,158 patients(32.8%)started KD after the failure of the second ASM,157 patients(32.6%)started KD after the failure of the third drug,and 86 patients(17.9%)started KD after the failure of the fourth and more.The KD effect was not related to the number of ASMs used before KD startup(P>0.05).Two hundred and eighteen patients(45.3%)failed to respond to corticotropin or glucocorticoid before initiation.There was no significant difference in the effectiveness rate at different time points between the group of KD therapy after glucocorticoid failure and the group after non-hormone failure (x^(2)=0.8613,P=0.8348).The rate of adverse events of KD in 1,3,6,and 12 months after KD initiation were 22.3,21.7,16.8 and 6.9%,respectively.The adverse events mainly occurred during the first 3 months of KD,and the main adverse events were gastrointestinal disturbance and constipation.Conclusions:The efficacy of the KD treatment for infantile spasms was not affected by age,medication,and glucocorticoid use before initiation.KD is one of the effective treatments for infantile spasms.

Comprehensive genome sequencing analyses identify novel gene mutations and copy number variations associated with infant developmental delay or intellectual disability(DD/ID)

To the Editor,Developmental delay or intellectual disability(DD/ID)is one of the most common neurodevelopmental disabilities worldwide with high clinical and genetic heterogeneity.Its etiology remains unexplained in nearly 70%of these patients,and an accurate diagnosis still poses a challenge in clinical practice.Previous DD/ID cohort studies mostly used panel sequencing or chromosome microarray analysis(CMA),but targeted capture probes could not be updated in time,resulting in an increased risk of missed detection of genetic abnormalities.