Identification of Monitoring Organ in Bivalves for Early Warning of Paralytic Shellfish Toxins Accumulation

Bivalve farming plays a dominant role in mariculture in China.Paralytic shellfish toxins(PSTs)can be accumulated in bivalves and cause poisoning the consumers.A sensitive detection of PSTs can provide early warning to decrease poisoning events in bivalve consuming.PSTs are traditionally examined using the whole soft-tissues.However,PSTs accumulation varies dramatically in different tissues of bivalves.Some tough tissues/organs(such as mantle),which account for a large proportion of the total soft body,exhibit a lower accumulation of PSTs and make the toxin extraction time-and reagent-consuming,potentially decreasing the accuracy and sensitivity of PSTs monitoring in bivalves.To develop a sensitive and cost-effective approach for PSTs examination in massively farmed bivalves,we fed three commercially important bivalves,Yesso scallop Patinopecten yessoensis,Pacific oyster Crassostrea gigas,and blue mussel Mytilus edulis with PSTs-producing dinoflagellate Alexandrium catenella,and detected PSTs concentration in different tissues.For all three bivalve species,the digestive gland accumulated much more PSTs than other tissues,and the digestive gland’s toxicity was significantly correlated with the PSTs toxicity of the whole soft-tissues,with r^(2)=0.94,0.92,and 0.94 for Yesso scallop,Pacific oyster,and blue mussel,respectively.When the toxicity of the whole soft-tissues reached 80μgSTXeq(100g)^(−1),the regulatory limit for commercial shellfish,the digestive gland’s toxicity reached 571.48,498.90,and 859.20μgSTXeq(100g)^(−1) in Yesso scallop,Pacific oyster,and blue mussel,respectively.Our results indicate that digestive gland can be used for the sensitive and cost-effective monitoring of PSTs in bivalves.

Acute acquired concomitant esotropia with congenital paralytic strabismus:A case report

BACKGROUND An unusual case of acute acquired concomitant esotropia(AACE)with congenital paralytic strabismus in the right eye is reported.CASE SUMMARY A 23-year-old woman presented with complaints of binocular diplopia and esotropia of the right eye lasting 4 years and head tilt to the left since 1 year after birth.The Bielschowsky head tilt test showed right hypertropia on a right head tilt.She did not report any other intracranial pathology.A diagnosis of AACE and right congenital paralytic strabismus was made.Then,she underwent medial rectus muscle recession and lateral rectus muscle resection combined with inferior oblique muscle myectomy in the right eye.One day after surgery,the patient reported that she had no diplopia at either distance or near fixation and was found to be orthophoric in the primary position;furthermore,her head posture immediately and markedly improved.CONCLUSION In future clinical work,in cases of AACE combined with other types of strabismus,we can perform conventional single surgery for both at the same time,and the two types of strabismus can be solved simultaneously.

Transfer of Paralytic Shellfish Toxins via Marine Food Chains:A Simulated Experiment

Objective To study the transfer of paralytic shellfish toxins （PST） using four simulated marine food chains： dinoflagellate Alexandrium tamarense→Artemia Artemia salina→Mysid shrimp Neomysis awatschensis; A. tamarense→N. awatschensis; A. tamarense→A, salina→Perch Lateolabrax japonicus; and A. tamarense→L, japonicus. Methods The ingestion of A. tamarense, a producer of PST, by L. japonicus, N. awatschensis, and A. salina was first confirmed by microscopic observation of A. tamarense cells in the intestine samples of the three different organisms, and by the analysis of Chl.a levels in the samples. Toxin accumulation in L. japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly through the vector of A. salina was then studied, The toxicity of samples was measured using the AOAC mouse bioassay method, and the toxin content and profile of A. tamarense were analyzed by the HPLC method. Results Both A. salina and N. awatschensis could ingest A. tamarense cells. However, the ingestion capability of A. salina exceeded that of N. awatschensis. After the exposure to the culture of A. tamarense （2 000 cells·mL^-1） for 70 minutes, the content of Chl.a in A. salina and N. awatschensis reached 0.87 and 0.024 μg.mg^-1, respectively. Besides, A. tamarense cells existed in the intestines of L. japonicus, N. awatschensis and A. salina by microscopic observation. Therefore, the three organisms could ingest A. tamarense cells directly. A. salina could accumulate high content of PST, and the toxicity of A. salina in samples collected on days 1, 4, and 5 of the experiment was 2.18, 2.6, and 2.1 MU.g^-1, respectively. All extracts from the samples could lead to death of tested mice within 7 minutes, and the toxin content in anemia sample collected on the 1st day was estimated to be 1.65×10 ^5 μg STX equal/individual. Toxin accumulation in L japonicus and N. awatschensis directly from the feeding on A. tamarense or indirectly from the vector ofA. salina was also studied. The mice injected with extracts from L japonicus and N. awatschensis samples that accumulated PST either directly or indirectly showed PST intoxication symptoms, indicating that low levels of PST existed in these samples. Conclusion Paralytic shellfish toxins can be transferred to L. japonicus, N. awatschensis, and A. salina from A. tamarense directly or indirectly via the food chains.

Multi-year assessment of paralytic shellfish toxins in hard clam species along the coastline of Jiangsu Province, China

Paralytic shellfish toxins(PSTs) are notorious neurotoxins that threaten public health and food safety worldwide.Although PST monitoring programs have recently been established throughout China, the profiles and variation of PSTs in important commercial clams(e.g., Mactra veneriformis, Ruditapes philippinarum, and Meretrix meretrix) along the Jiangsu Province coastline remain largely unexplored. In this study, a validated hydrophilic interaction liquid chromatography–tandem mass spectrometry(HILIC-MS/MS) method was used to examine PST profiles and levels in 540 clam samples from natural production areas along Jiangsu Province coastline during2014–2016. Although the PST levels(≤6.38 μg saxitotoxin equivalents(eq)/kg) were consistently below European Union regulatory limits(≤800 μg saxitotoxin eq/kg) during this time period, saxitotoxin, decarbamoylsaxitotoxin,and gonyautoxins 1 and 4 were detected, and nearly 40% of the samples were saxitotoxin-positive. The PST levels also varied significantly by seasons, with peak values observed in May during 2014–2016. This is the first systematic report of PSTs in clams from Jiangsu Province, and additional research and protective measures are needed to ensure the safety of clams harvested in this area.

Identifi cation of paralytic shellfi sh toxin-producing microalgae using machine learning and deep learning methods

Paralytic shellfi sh poisoning(PSP)microalgae,as one of the harmful algal blooms,causes great damage to the of fshore fi shery,marine culture,and marine ecological environment.At present,there is no technique for real-time accurate identifi cation of toxic microalgae,by combining three-dimensional fluorescence with machine learning(ML)and deep learning(DL),we developed methods to classify the PSP and non-PSP microalgae.The average classifi cation accuracies of these two methods for microalgae are above 90%,and the accuracies for discriminating 12 microalgae species in PSP and non-PSP microalgae are above 94%.When the emission wavelength is 650-690 nm,the fl uorescence characteristics bands(excitation wavelength)occur dif ferently at 410-480 nm and 500-560 nm for PSP and non-PSP microalgae,respectively.The identification accuracies of ML models(support vector machine(SVM),and k-nearest neighbor rule(k-NN)),and DL model(convolutional neural network(CNN))to PSP microalgae are 96.25%,96.36%,and 95.88%respectively,indicating that ML and DL are suitable for the classifi cation of toxic microalgae.

Comparative study on in vitro transformation of paralytic shellfish poisoning (PSP) toxins in different shellfish tissues

Dissected tissues of three shellfish species, the Chinese scallop, Chlamys farreri, Manila clam, Ruditapes philippinarurn, and Razor shell, Solen strictu were evaluated for in vitro transformation of paralytic shellfish poisoning （PSP） toxins. Tissue homogenates were incubated with extraction from toxic algae Alexandriurn rninutura to determine toxin conversion. The effects of heating and addition of a natural reductant （glutathione） on toxin conversion were also assessed. The toxin profile was investigated through high performance liquid chromatography with fluorescence detection （HPLC-FLD）. The evident variations in the toxin content were observed only in Chinese scallop viscera homogenates. The concentration of GTX4 was reduced by 45% （approximately 0.8 μmol/dm^3） and 25% （approximately 1 μmol/dm^3） for GTX1, while GTX2 and GTX3 increased by six times （approximately 1 μmol/dm^3） and 3 times （approximately 0.3μmol/dm^3） respectively. Simultaneously, the total toxicity decreased by 38% during the 48 h incubation period, the final toxicity was 20.4 nmol STXeq/g. Furthermore, heated Chinese scallop viscera homogenates samples were compared with non-heated samples. The concentration of the GTX4 and GTX1 was clearly 28% （approximately 0.53 μmol/dm^3） and 17% （approximately 0.69μmol/dm^3） higher in heated samples, GTX2 and GTX3 were four times （0.66 μmol/dm^3） and two times （0.187 μmol/dm^3） lower respectively. GSH （＋） Chinese scallop viscera homogenates samples were compared with GSH （-） samples, the concentration in the GTX4 and GTX1 was 9% （approximately 0.12 μmol/dm^3） and 11% （approximately 0.36 μmol/dm^3） lower respectively, GTX2 and GTX3 was 17% （approximately 0.14 μmol/dm^3） and 19% （approximately 0.006 μmol/dm^3） higher respectively. In contrast,there was a little change in the concentration of PSP toxins of Manila clam and Razor shell tissue ho- mogenates. These observations on three shellfish tissues confirmed that there were species-specific differences in PSP toxins transformation. PSP toxins transformation was more pronounced in viscera tissue than in muscle tissue. PSP toxins was possibly interfered by some carbamoylase enzyme, and the activity in Chinese scallop viscera tissue is more remarkable than in the other two species.

Depuration of paralytic shellfish toxins in Japanese scallop(Patinopecten yessoensis) in natural environment

To study the paralytic shellfish toxins（PSTs） depuration in Japanese scallop Patinopecten yessoensis in natural environment, Japanese scallops naturally contaminated with paralytic shellfish poisoning（PSP） toxins in the Dayao Bay in the northern Huanghai Sea are transited to Qipanmo waters in the Bohai Sea of no reported PSTs incidents. The levels and profile of PSTs during 30-day depuration are detected by the high performance liquid chromatography with fluorescence detection（HPLC-FLD）. The results show that the toxicity of the PSTs in soft tissues decreases to a relatively low level at Day 9. Moreover, the depurated ratio at the early stage of the PSTs depuration is higher than that at the later stage. The toxicity analysis of dissected organs reveals that the digestive gland is the most contaminated PSTs part, which is of important implication for the human health and scallop aquiculture. The mortality of Japanese scallops during PSTs depuration experiment is relevant to PSTs level in the soft tissue.

Surgical Correction for Paralytic Strabismus Using T-Plate Anchor

External or internal ophthalmoloplegia will result in a complete or a partial ocular dysmotility leading to a debilitating and variable manifest binocular diplopia for a majority of the patients. Complete third, forth and sixth nerve cranial nerve palsies are among the many number of etiologies appearing as paralytic strabismus. Successful clinical management, elimination of symptomatic diplopia in the primary field of gaze and increased binocular field of motor and sensory fusion as a result of the oculomotor nerve (III) palsy are challenging tasks for physicians facing this difficult clinical entity. Here we report a novel surgical technique in the clinical management of this disease through suture-fixation of medial rectus muscle onto Titanium plate (T-plate) already anchored into the nasal orbital wall.

A Transcriptome Analysis of Neural Tissue of Litopenaeus vannamei After Acute Exposure to Alexandrium pacificum

Alexandrium pacificum(A.pacificum)is a typical paralytic shellfish poisonous dinoflagellate.Harmful algal blooms(HABs)caused by this species can bring serious environmental problems and economic losses to the aquaculture industry.In this study,transcriptome sequencing and analyses were performed on the neural tissue of Litopenaeus vannamei(L.vannamei)after acute exposure to A.pacificum disrupted solution for 72 h,and differentially expressed genes(DEGs)were identified.The results showed that,compared with the control samples,300 DEGs were identified in the experimental group,of which 194 were up-regulated,and 106 down-regulated.The gene ontology(GO)functional enrichment analysis showed that DEGs were significantly enriched in the cortical cytoskeleton organization,troponin complex,amylo-alpha-1,6-glucosidase and thymidine phosphorylase.Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis found that DEGs were mainly enriched in the oxidative phosphorylation process,intercellular tight junctions and mitophagy.The results showed that the proteoglycans,signaling pathways,and various metabolic processes that regulate cell proliferation,differentiation,and apoptosis all played an essential role in the response of L.vannamei to A.pacificum toxins.

A Case Report on Treating Progressive Supranuclear Palsy with a Combination of Chinese and Western Medicine

A case of progressive supranuclear palsy in a 66-year-old woman is presented.The patient complained of“progressive stiffness of both lower limbs for five years,accompanied by choking and coughing for more than 1 year,”and was diagnosed with paralysis in traditional Chinese medicine(TCM),which was characterized by a deficiency of liver and kidney,and phlegm and blood stasis blocking the collaterals.Western medicine diagnosed it as progressive supranuclear palsy.The patient was diagnosed with“Parkinson’s disease”several times in the past and was given“polybasic hydrazide”and“amantadine hydrochloride tablets,”etc.The patient did not have significant symptomatic relief,so she sought further treatment with a combination of traditional Chinese and Western medicine.Based on the concept of deficiency and excess,this disease is categorized as a paralytic disease in Chinese medicine,and the onset of the disease is closely related to the deficiency of the body after a long period of illness,with wind,phlegm,blood stasis,and deficiency as the main pathogenetic mechanism.The treatment is based on the combination of disease and evidence,with traditional Chinese medicine and acupuncture as the main treatments,supplemented by intermediate-frequency pulsed electrical stimulation,transcranial repetitive magnetic stimulation,medicated canisters,wax therapy,traditional Chinese medicine guasha,and acupoint injections.Western medicine is based on symptomatic treatment,and the patient’s symptoms were relieved significantly after the combination of Chinese and Western medicine.

链状裸甲藻所产麻痹性贝类毒素在翡翠贻贝体内的累积、转化和排出

为研究链状裸甲藻所产麻痹性贝类毒素(paralytic shellfish toxins,PST)在翡翠贻贝体内的累积、转化和排出规律,设置试验组和对照组,采用链状裸甲藻和中肋骨条藻投喂翡翠贻贝,开展短期累积(12 h)、长期累积(10 d)和排出(28 d)试验。结果表明:翡翠贻贝具有较强的毒素累积能力,内脏团是PST累积的主要部位,PST含量与产毒藻密度呈显著正相关关系。当链状裸甲藻密度为1.0×10^(6)cells/L时,贻贝内脏团PST含量累积2 h已接近食用贝类毒素安全标准,累积8 h超标。当产毒藻密度为5.0×10^(5)cells/L时,贻贝内脏团PST含量累积2 d超标,累积8 d达到峰值(3590.4±545.7)μg/kg。贻贝对PST具有累积快排出慢的特点,内脏团PST含量在排出16 d达标,排出速率先快后慢。内脏团对PST的累积和排出速率显著高于闭壳肌和其他组织,闭壳肌和其他组织则无显著差异。PST进入贻贝体内后发生了代谢转化,贻贝可能将产毒藻中膝沟藻毒素GTX3转化为GTX2,N-磺酰氨甲酰基膝沟藻毒素C2转化为C1,部分C1转化为脱氨甲酰基膝沟藻毒素2(dcGTX2),并将高毒的石房蛤毒素(STX)转化为较低毒的脱氨甲酰基石房蛤毒素(dcSTX)。贻贝对dcSTX有较强的累积能力且排出能力较弱,肝胰腺和肾可能是PST累积的主要部位。该研究可为贝类脱毒与净化、赤潮减灾和水产品质量风险防控提供基础数据和理论依据。

基于SPE与SPATT的水体中麻痹性贝类毒素检测方法构建与应用

为实现麻痹性贝类毒素(paralytic shellfish poisoning,PSP)的实时监控与提前预警,本研究构建了基于固相萃取技术(solid phase extraction,SPE)与固相吸附毒素跟踪技术(solid phase adsorption toxin tracking,SPATT)的水体中PSP检测方法,重点优化了吸附材料及前处理方法,评价了回收率、检出限等指标,并将方法应用于2019年春季秦皇岛山海关海域PSP消长过程的监测中,比较评估了两种方法的监控预警效果。结果表明:SPE方法选用ENVI-Carb 500mg/6mL固相萃取柱,过样体积为50mL,13种PSP组分的平均回收率为82.2%±10.0%、检出限为4.0-20.0ng/L;SPATT方法选用SP207大孔吸附树脂,洗脱时间为静置Id最佳,整体回收率约为9.2%;在实际应用中,结合产毒藻密度及贻贝富集毒素含量的变化,发现SPE方法的检测结果可实时表征海域PSP风险状况,对于贻贝中PSP的预警效果也显著优于SAPTT方法,后者不仅因监控方式相对滞后一个监测周期,且灵敏度及准确性均较差。对于秦皇岛海域,当SPE方法检测结果达到100ng STX eq/L时,该海域贻贝中PSP残留将具有潜在的食用安全风险,跟踪过程表明这一阈值可提前两周预警贻贝富集毒素含量超出我国限量标准(800μg STX eq/kg),这对于强化风险警示并制定防范措施具有积极作用。

Biodiversity of the Symbiotic Bacteria Associated with Toxic Marine Dinoflagellate Alexandrium tamarense

Paralytic shellfish poisoning (PSP) toxins are potent neurotoxins mainly produced by dinoflagellates and being concentrated in bivalves through food web transfer. Increasing number of findings of toxin-producing bacteria in the cells of dinoflagellate such as Alexandriumtamarense supports the hypothesis of the bacterial origin of PSP toxins. Evidence that there are specific symbiosis bacterial taxa associated with the phytoplankton indicates the presence of specific selective mechanisms between them, and implies that the symbiosis bacteria have some vital function to the benefit of the dinoflagellates. Studies on the role of toxin-producing symbiosis bacteria in the marine ecosystem are considered to be becoming more important. Although toxigenic bacteria could be isolated from toxic dinoflagellates, it was not clearly proven whether the isolated bacterial strains based on culture-dependent manner and the corresponding intracellular bacteria were the same because of microbial unculturability. This paper aims to demonstrate the biodiversity of the symbiotic bacteria associated with toxic dinoflagellate A. tamarense using the culture-indepen- dent high-throughput pyrosequencing method, as well as the phylogenetic analysis based on 16S rDNA sequences of the symbiotic cultivable bacteria strains isolated from toxic Alexander tamarense.

Intestinal ascariasis at pediatric emergency room in a developed country

Ascaris lumbricoides infection is rare among children in developed countries.Although large numbers of adult Ascaris in the small intestine can cause various abdominal symptoms,this infection remains asymptomatic until the number of worms in the intestine considerably increases in most cases.Ascaris causing bilious vomiting suggesting ileus is rare,especially in developed countries.A 6-year-old boy who lived in Japan,presented with abdominal colic,bilious vomiting at the pediatric emergency room.He appeared pale,and had no abdominal distention,tenderness,palpable abdominal mass,or findings of dehydration.He experienced bilious vomiting again during a physical examination.Laboratory tests showed mild elevation of white blood cells and C-reactive protein levels.Antigens of adenovirus,rotavirus,and norovirus were not detected from his stool,and stool culture showed normal flora.Ultrasonography showed multiple,round-shaped structures within the small intestine,and a tubular structure in a longitudinal scan of the small intestine.Capsule endoscopy showed a moving worm of Ascaris in the jejunum.Intestinal ascariasis should be considered as a cause of bilious vomiting in children,even at the emergency room in industrial countries.Ultrasound examination and capsule endoscopy are useful for diagnosis of pediatric intestinal ascariasis.

Mapping the resting cysts of dinoflagellate Alexandrium catenella along the coast of Qinhuangdao,China

Dinoflagellate Alexandrium catenella is a cosmopolitan bloom-forming species with complex life cycle,the formation and germination of resting cysts are critical for its bloom dynamics.In the coastal waters of Qinhuangdao,A.catenella has been identified as the major causative agent for paralytic shellfish poisoning,but there is little knowledge concerning its resting cysts in this region.In this study,three surveys were carried out along the coast of Qinhuangdao from 2020 to 2021 to map the distribution of A.catenella resting cysts,using a quantitative PCR(qPCR)assay specific for A.catenella.The resting cysts were detected in surface sediments during all the three surveys,and their distribution patterns were similar.High abundance of resting cysts(maximum 1300 cysts/g sediment(wet weight))were found in a region(119.62°E-119.99°E,39.67°N-39.98°N)northeast to the coastal waters of Qinhuangdao,where surface sediments were mainly composed of clay and silt(percentage above 50%).Prior to the formation of the A.catenella bloom in March 2021,the abundance of A.catenella vegetative cells in seawater had extremely significant positive correlation with the abundance of resting cysts in surface sediments,reflecting the important role of resting cysts in the initiation of A.catenella blooms.As far as we know,this is the first report on the distribution of A.catenella cysts along the coast of Qinhuangdao.The results will of fer a sound basis for the future monitoring and mitigation of toxic A.catenella blooms and paralytic shellfish poisoning events in this region.

Congenital dysplasia involving both medial and inferior recti: clinical features and surgical outcomes

AIM: To investigate the clinical features and surgical outcomes of congenital dysplasia involving both inferior recti(IR) and medial recti(MR) muscles.METHODS: A retrospective review was conducted including cases of simultaneous congenital dysplasia of IR and MR that were diagnosed and surgically treated at the Zhongshan Ophthalmic Center, Sun Yat-sen University, China, from July 2009 to November 2019. Ocular motility, ocular alignment at distance(6 m) and near(33 cm) by prism alternating cover test and stereoacuity were assessed in all patients before and after surgery. RESULTS: A total of five patients(four males and one female;three with right eye and two with left eye congenital dysplasia) were included in this review. The patients ranged in age from 10 to 42 y(21±13.4 y). The main clinical findings were hypertropia and exotropia of the affected eye, along with motility limitations in adduction and depression. Lateral rectus(LR) recession/transposition combined with IR resection was performed in one case. Two scheduled surgeries were performed in four cases, with one involving superior rectus recession and IR resection and the others LR recession and MR resection. Mean±SD pre-surgical exotropia of 51.0±31.11 prism diopter(PD) and hypertropia of 29.20±7.12 PD in the primary position were decreased to 3.6±12.90 and 3.2±10.09 PD, respectively, at two years after surgery, with a success rate of 60% and an undercorrection rate of 40%. CONCLUSION: The main clinical features associated with simultaneous MR/IR congenital dysplasia are hypertropia and exotropia of the affected eye along with motility limitations in adduction and depression. Scheduled two-stage surgeries achieved a success rate of 60%.

Minimally invasive botulinum toxin type A injection from the ocular surface to extraocular muscles

AIM: To investigate a new, safe and effective injection method for strabismus patients. Botulinum toxin type A (BTXA) was injected by pulling the extraocular muscles with a minimally-invasive technique into the ocular surface, and it was ensured that the extraocular muscles was maintained in the suspended state. METHODS: A total of 32 patients with different types of strabismus were treated at our institution from February to October 2010. A small conjunctival incision (<= 2mm) was made under a microscope. The extraocular muscles were pulled out with a hook to ensure an elevated position compared with the wall of eyeball. The muscle fiber was clearly seen through the conjunctiva and BTXA was injected at a small angle under the microscope. The deviation angles before and after the injection were recorded. All patients were followed up at 5 and 30 days after the operation. Recovery was defined as abolition of diplopia in straight-ahead gaze and anteroinferior gaze and the symptoms of giddiness disappeared thoroughly. Eyeball position was Essentially normal. Improvement was defined as basic disappearance of diplopia in straight-ahead gaze and anteroinferior gaze; restriction of action of paralytic muscle improved. If most of the symptoms and signs still existed and disturbed normal work and life, the treatment was determined to be invalid. The injection dose for patients of 5 to 10 prism diopter (PD), 11 to 20PD, and >= 21PD was 1u, 3u and 4u to 5u, respectively. RESULTS: Of the 32 treated patients, 11 (34.4%) were cured, and 18 (56.3%) were improved at 5 days after the operation; 12 (40%) were cured, and 15 (46.9%) were improved at 30 days. Five patients (15.6%) who had unsatisfactory response after BTXA injection at 30 days received repeated injections or underwent strabismus surgery. Ptosis was present in 2.5% of the injected eyes. No retrobulbar hemorrhage or ocular perforation was found in any eye. CONCLUSION: It is safe and efficient to inject BTXA by pulling extraocular muscles with a minimally-invasive technique under the microscope to make the muscles separated from the wall of eyeball.

Pediatric case with vaccine-related poliovirus infection: A case report

BACKGROUND As long as oral poliovirus vaccine(OPV)is used,the potential risk for the emergence of vaccine-related polioviruses remains.CASE SUMMARY We report a case of Sabin-like type 1 poliovirus infection in an immunocompetent 17-mo-old child after receiving four scheduled doses of OPV.Somehow,the four doses did not confer full protection,possibly because of interference created by other enteroviruses.CONCLUSION The surveillance of vaccine-related polioviruses has important implications for improving health policies and vaccination strategies.Missed cases of vaccinerelated poliovirus infection might pose a potential risk to global poliovirus eradication.Therefore,the global withdrawal of OPV and a shift to the inclusion of only inactivated poliovirus vaccine in the vaccination schedule is the main objective of the polio eradication program.

Glutathione S-transferase genes in scallops and their diverse expression patterns after exposure to PST-producing dinoflagellates

The glutathione S-transferases(GSTs)are a superfamily of enzymes that function in cellular protection against toxic substances and oxidative stress.Bivalves could accumulate high concentration of paralytic shellfish toxins(PSTs)from harmful algae.To understand the possible involvement of GSTs in protecting bivalves during PST accumulation and metabolism,the GST genes were systemically analyzed in two cultured scallops,Azumapecten farreri and Mizuhopecten yessoensis,which were reported for PST deposition during harmful algae bloom.A total of 35 and 37 GSTs were identified in A.farreri(AfGSTs)and M.yessoensis(MyGSTs)genome,respectively,and the expansion of the sigma class from the cytosolic subfamily was observed.In both scallop species,sigma class GSTs showed higher expression than other members.The high GSTs expression was detected mainly during/after larvae stages and in the two most toxic organs,hepatopancreas and kidney.After ingesting PST-producing dinoflagellates,all the regulated AfGSTs in the hepatopancrcas were from the sigma class,but with opposite regulation pattern between Alexandrium catenella and A.minutum exposure.In scallop kidneys,where PSTs transformed into higher toxicity,more AfGSTs were regulated than in the hepatopancreas,and most of them were from the sigma class,with similar regulation pattern between A.catenella and A.minutum exposure.In M.yessoensis exposed to A.catenella,MyGST-σ2 was the only up-regulated MyGST in both hepatopancreas and kidney.Our results suggested the possible diverse function of scallop GSTs and the importance of sigma class in the defense against PSTs,which would contribute to the adaptive evolution of scallops in marine environments.