Multiple thoracic and abdominal foregut duplication cysts:A case report

BACKGROUND Congenital enteric duplication cysts are tubular or cystic structures that normally lie alongside the gastrointestinal(GI)tract.Enteric duplication cysts are typically solitary lesions that occur anywhere near the GI tract from the neck to the rectum,but having multiple duplication cysts is rare,and presentation within the pancreas is extremely rare.CASE SUMMARY We herein demonstrate a case of esophageal,gastric,and gastric-type duplication cyst of the pancreas in a seventeen-month-old girl who presented with failure to thrive,abdominal pain,vomiting,hematemesis,and melena since the age of three months.The cysts were excised by thoracoscopy and laparoscopy in the same setting.To our knowledge,no such case has been published.CONCLUSION Enteric duplications can occur throughout the entire alimentary tract.When they occur in the pancreas,they present a formidable challenge in both diagnosis and treatment.Due to the risk of complications and malignant transformation,surgical removal is the recommended treatment of all duplication cysts.

Design of 16S rRNA gene primers for 454 pyrosequencing of the human foregut microbiome

AIM:To design and validate broad-range 16S rRNA primers for use in high throughput sequencing to classify bacteria isolated from the human foregut microbiome.METHODS:A foregut microbiome dataset was constructed using 16S rRNA gene sequences obtained from oral,esophageal,and gastric microbiomes produced by Sanger sequencing in previous studies represented by 219 bacterial species.Candidate primers evaluated were from the European rRNA database.To assess the effect of sequence length on accuracy of classification,16S rRNA genes of various lengths were created by trimming the full length sequences.Sequences spanning various hypervariable regions were selected to simulate the amplicons that would be obtained using possible primer pairs.The sequences were compared with full length 16S rRNA genes for accuracy in taxonomic classification using online software at the Ribosomal Database Project (RDP).The universality of the primer set was evaluated using the RDP 16S rRNA database which is comprised of 433 306 16S rRNA genes,represented by 36 phyla.RESULTS:Truncation to 100 nucleotides(nt)downstream from the position corresponding to base 28 in the Escherichia coli 16S rRNA gene caused misclassification of 87(39.7%)of the 219 sequences,compared with misclassification of only 29(13.2%)sequences with truncation to 350 nt.Among 350-nt sequence reads within various regions of the 16S rRNA gene,the reverse read of an amplicon generated using the 343F/798R primers had the least(8.2%)effect on classification.In comparison,truncation to 900 nt mimicking single pass Sanger reads misclassified 5.0%of the 219 sequences.The 343F/798R amplicon accurately assigned 91.8%of the 219 sequences at the species level.Weighted by abundance of the species in the esophageal dataset,the 343F/798R amplicon yielded similar classification accuracy without a significant loss in species coverage(92%).Modification of the 343F/798R primers to 347F/803R increased their universality among foregut species.Assuming that a typicalpolymerase chain reaction can tolerate 2 mismatches between a primer and a template,the modified 347F and 803R primers should be able to anneal 98%and 99.6%of all 16S rRNA genes in the RDP database.CONCLUSION:347F/803R is the most suitable pair of primers for classification of foregut 16S rRNA genes but also possess universality suitable for analyses of other complex microbiomes.

Endoscopic foregut surgery and interventions:The future is now.The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic,the content will progress as follows: "lessons learned", "technical considerations"and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years.Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver,pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease(GERD), achalasia, esophageal diverticula, Barrett's esophagus(BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors.For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy(POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique(Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection(ESD)which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies(radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy.Importantly, in regard to early gastric cancer and submucosal tumors(SMTs) of the stomach, ESD and full thickness resection(FTR) can excise these lesions enbloc and endoscopic suturing is now used to close large defects and perforations.For treatment of patients with malignant gastric outlet obstruction(GOO),endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty(ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound(EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

Ciliated hepatic foregut cyst:an increasingly diagnosed condition

BACKGROUND:Ciliated foregut cysts of the liver are rare, with only 96 cases diagnosed since the first description in 1857.They are being increasingly diagnosed recently;the majority of the cases have been reported in the last 15 years. Although they bear a close resemblance to the simple cyst of the liver which has essentially a benign course,ciliated hepatic foregut cysts(CHFCs)can progress to malignancy with devastating consequences.It is imperative that this group of conditions be diagnosed and treated adequately. DATA SOURCES:This review includes discussion of the data from all the 96 reported cases from English and non-English literature.Analysis of the incidence rates, embryogenesis,growth,clinical features,risk of malignancy and the prognosis are highlighted systematically.The roles of various diagnostic modalities including ultrasound, CT,MRI,fine needle aspiration cytology(FNAC), immunohistochemistry and surgery are further discussed. RESULTS:The mean age of patients with CHFC was 48± 12 years.The male/female ratio was 1.1∶1.The majority of patients with CHFC(62%)were asymptomatic,and the common mode of presentation was right upper abdominal pain.The cysts occurred in the left lobe in 51 patients, with sole location in segmentⅣin 44,and in the right lobe in 26.The average size of the cysts was 3.6±2.12 cm. The majority of the cysts were unilocular,and only 7 cases were multilocular.Cyst contents were described as viscous or mucinous in 73 patients,whereas bilious fluid was noted in 3.Large cysts having squamous carcinoma were cited in 3 patients,and 2 had extensive squamous metaplasia without malignancy.Others had benign histopathology. CONCLUSIONS:Clinicians have become increasingly aware of CHFC.Imaging alone is not diagnostic per se, but when considered in the context of the global picture does provide important clues to the diagnosis.FNAC is diagnostic by the presence of the ciliated columnar aspirate but lacks sensitivity.Infantile presentation is usually accompanied by biliary communication and mandates a different surgical approach.The demonstration of malignant transformation in 3 cases and its fatal course emphasizes the need for surgical resection in all cases once the diagnosis is made.

Robotic Foregut Surgery: One Surgeon’s Experience with Nissen Fundoplication, Esophagomyotomy, and Hiatal Hernia Repair

Purpose: The purpose of the study was to review a single surgeon, seven-year experience, using the Da Vinci Telerobotic system performing 124 foregut operations. Methods: Data review from 2002-2009 including 71 Nissen fundoplications, 26 esophagomyotomies, and 27 hiatal hernia repairs was performed. Parameters collected included gender, age, body mass index (BMI), estimated blood loss (EBL), port set up time (PST), robot operating time (ROT), total case time (TCT), length of stay (LOS), complications, conversions, and resident involvement. Statistical analysis was con-ducted. Results: 124 foregut operations: 45 males, 79 females, mean age of 54.8 ± 16.7 (18 - 85) years, mean TCT 174.4 ± 45.0 (102 - 321) min. Nissen fundoplication: mean BMI of 30.8 ± 3.9 (22.4 - 46.8) kg/m2, EBL 30.2 ± 21.8 (5 - 100) ml, PST 32.3 ± 9 (14 - 63) min, ROT 111.4 ± 37.3 (51 - 229) min, TCT 175.0 ± 46.4 (102 - 321) min, median LOS 1 (0 - 9) day, complication rate 7.0% (5/71), conversion rate 5.6%, resident involvement 69.0% (49/71). Esophagomyotomy: mean BMI of 26.5 ± 6.1 (15.4 - 36.6) kg/m2, EBL 39.1 ± 41.7 (10 - 200) ml, PST 28.0 ± 8.6 (16 - 47) min, ROT 122.9 ± 45 (31 - 217) min, and TCT 178.0 ± 40.5 (105 - 262) min, median LOS 1 (0 - 6) day, complication rate 15.4% (4/26), conversion rate 0%, resident involvement 69.2% (18/26). Hiatal hernia repair: mean BMI of 28.4 ± 4.2 (21.9 - 36.8) kg/m2, EBL 38.4 ± 32.7 (10 - 150) ml, PST 28.8 ± 8.0 (17 - 52) min, ROT 109.0 ± 44.5 (49 - 250) min, and TCT 169.2 ± 46.5 (102 - 299) min, median LOS 1 (1 - 14) day, complication rate 11.1% (3/27), conversion rate 3.7%, resident involvement 66.7% (18/27). Conclusion: Robotic-assisted foregut surgery is safe and effective. This series compares favorably with other robotic studies in length of hospital stay, total case time, and complication and conver-sion rates. Foregut surgery is an excellent robotic training ground for residents.

Ciliated hepatic foregut cyst with high intra-cystic carbohydrate antigen 19-9 level

A ciliated hepatic foregut cyst(CHFC)is a rare foregut developmental malformation usually diagnosed in adulthood.Five percent of reported cases of CHFC transform into squamous cell carcinoma.We report the presentation,evaluation,and surgical management of a symptomatic 45-year-old male found to have a 6.2 cm CHFC.Contrast tomography-guided fine-needle aspirationdemonstrated columnar,ciliated epithelium consistent with the histologic diagnosis of CHFC.The intracystic levels of carbohydrate antigen(CA)19-9 and carcinoembryonic antigen(CEA)were extremely high(978118U/m L and 973μg/L,respectively).Histologically,the wall of the cyst showed characteristic pseudopapillae lined with a ciliated stratified columnar epithelium,underlying smooth muscle,an outer fibrous layer and no atypia.Immunohistochemistry for CA19-9 and CEA was positive.This is the first case report of a CHFC in which levels of CA 19-9 and CEA were measured.Our findings suggest that a large sized multilocular cyst and elevated cyst CA19-9 and CEA levels do not exclude a CHFC from consideration in the diagnosis.CHFCs should be included in the differential diagnosis of hepatic lesions.Accurate diagnosis of a CHFC is necessary given its potential for malignant transformation,and surgical excision is recommended.

Role of SOX2 in foregut development in relation to congenital abnormalities

The uptake of the two essential ingredients for life, oxygen and nutrients, occurs primarily through the oral cavity, but these two lifelines need to be separated with high accuracy once inside the body. The two systems, the gas exchange pulmonary system and the gastro-intestinal feeding system, are derived from the same primitive embryonic structure during development, the foregut, which need to be separated before birth. In certain newborns, this separation occurs not or insufficiently, leading to life threatening conditions, sometimes incompatible with life. The development of the foregut, trachea and lungs is influenced and coordinated by a multitude of signaling cascades and transcription factors. In this review, we will highlight the development of the foregut and pulmonary system and focus on associated congenital abnormalities in light of known genetic alterations with specific attention to the transcription factor SOX2.

Ciliated Hepatic Foregut Cyst: 103 Cases in the World Literature

Ciliated hepatic foregut cysts (CHFC) are rare, typically benign, lesions whose incidence has been increasing recently. Despite this increase in incidence, they remain rare and several key characteristics remain poorly understood, including the range of presentation and the risk of malignant conversion. To better understand CHFC, an extensive review of the international literature was performed. Characteristics including size, location, contents, presenting symptoms, and risk of malignancy were analyzed. In addition, an illustrative case is presented to highlight a potential pitfall in diagnosis: Although the presentation is thought to be typically painless or vaguely painful, these lesions may also present with hemorrhage and sudden severe abdominal pain. Importantly, although malignant degeneration is uncommon, analysis revealed that malignancy is significantly associated with size, which was significantly larger (median 10 cm) in malignant CHFC compared with the typical benign CHFC (3 cm) (P < 0.01). Large or symptomatic cysts, or small asymptomatic cysts that are atypical, should be resected.

Endoscopic submucosal dissection for foregut neuroendocrine tumors:An initial study

AIM:To evaluate the feasibility and efficacy of endoscopic submucosal dissection(ESD) for foregut neuroendocrine tumors(NETs).METHODS:From April 2008 to December 2010,patients with confirmed histological diagnosis of foregut NETs were included.None had regional lymph node enlargement or distant metastases to the liver or lung on preoperative computerized tomography scanning or endoscopic ultrasonography(EUS).ESD was attempted under general anesthesia.After making several marking dots around the lesion,a mixture solution was injected into the submucosa.The mucosa was incised outside the marking dots.Dissection of the submucosal layer beneath the tumor was performed under direct vision to achieve complete en bloc resection of the specimen.Tumor features,clinicopathological characteristics,complete resection rate,and complications were evaluated.Foregut NETs were graded as G1,G2,or G3 on the basis of proliferative activity by mitotic count or Ki-67 index.All patients underwent regular follow-up to evaluate for any local recurrence or distant metastasis.RESULTS:Those treated by ESD included 24 patients with 29 foregut NETs.The locations of the 29 lesions are as follows:esophagus(n = 1),cardia(n = 1),stomach(n = 23),and duodenal bulb(n = 4).All lesions were found incidentally during routine upper gastrointestinal endoscopy for other indications,and none had symptoms of carcinoid syndrome.Preoperative EUS showed that all tumors were confined to the submucosa.Among the 24 gastric lesions,16 lesions in 11 patients were type I gastric NETs arising in chronic atrophic gastritis with hypergastrinemia,while the other 8 solitary lesions were type Ⅲ because of absence of atrophic gastritis in these cases.All of the tumors were removed in an en bloc fashion.The average maximum diameter of the lesions was 9.4 mm(range:2-30 mm),and the procedure time was 20.3 min(range:10-45 min).According to the World Health Organization 2010 classification,histological evaluation determined that 26 lesions were NET-G1,2 gastric lesions were NET-G2,and 1 esophageal lesion was neuroendocrine carcinoma(NEC).Complete resection was achieved in 28 lesions(28/29,96.6%),and all of them were confined to the submucosa in histopathologic assessment with no lymphovascular invasion.The remaining patient with NEC underwent additional surgery because the resected specimens revealed angiolymphatic and muscularis invasion,as well as incomplete resection.Delayed bleeding occurred in 1 case 3 d after ESD,which was managed by endoscopic treatment.There were no procedure-related perforations.During a mean follow-up period of 24.4 mo(range:12-48 mo),local recurrence occurred in only 1 patient 7 mo after initial ESD.This patient successfully underwent repeat ESD.Metastasis to lymph nodes or distal organs was not observed in any patient.No patients died during the study period.CONCLUSION:ESD appears to be a safe,feasible,and effective procedure for providing accurate histopathological evaluations and curative treatment for eligible foregut NETs.

Foregut duplication cysts of the stomach with respiratory epithelium

Gastrointestinal duplication is a congenital rare disease entity. Gastric duplication cysts seem to appear even more rarely. Herein, two duplications cysts of the stomach in a 46 year-old female patient are presented. Abdominal computed tomography demonstrated a cystic lesion attached to the posterior aspect of the gastric fundus, while upper gastrointestinal endoscopy was negative. An exploratory laparotomy revealed a non-communicating cyst and a smaller similar cyst embedded in the gastrosplenic ligament. Excision of both cysts along with the spleen was performed and pathology reported two smooth muscle coated cysts with a pseudostratified ciliated epithelial lining (respiratory type).

Imaging features of ciliated hepatic foregut cyst

Ciliated hepatic foregut cyst (CHFC) is a very rare cystic lesion of the liver that is histologically similar to bronchogenic cyst. We report one case of CHFC that was hard to distinguish from solid-cystic neoplasm in imaging features. Magnetic resonance imaging was helpful in differentiating these cysts from other lesions.

Ciliated hepatic foregut cyst： report of first case in China and review of literature

Objective: To report the first case of ciliated hepatic foregut cyst in China, and review of literature to introduce the characteristics of this disease for doctors to recognize this disease.Method: Report the clinical procedure of diagnosis and treatment for the first case of ciliated hepatic foregut cyst in China, and to review the embryologic genesis, incidence,clinical manifestation, radiologic features and therapeutic principle of this disease. Results: We performed the resection for ciliated hepatic foregut cyst under laparoscopy; the patient recovered well after the procedure. Conclusion: Ciliated hepatic foregut cyst is quite rare clinically, belongs to non-parasitic,solitary and unilocular cystic lesion, is always less than 4cm in diameter, mostly seen in the left lobe, and has the tendency of malignant change. It should be removed as soon as diagnosed.

New insight into foregut functions of xenobiotic detoxification in the cockroach Periplaneta americana

The physiological functions of insect foregut,especially in xenobiotic detox ification,are scarcely reported because of unimportance in appearance and insufficient molecular information.The cockroach Periplaneta americana,an entomological model organism,provides perfect material to study physiological functions of foregut tissue due to its architectuxal feature.Through Illumina sequencing of foregut tissue from P.amer icana individuals (control)or insects treated with cycloxaprid,as a novel neonicotinoid insecticide,54 193 166 clean reads were obtained and further assembled into 53 853 unigenes with an average length of 366 bp.Furthermore,the number of unigenes involved in xenobiofic detoxification was analyzed,mainly including 70 cytochrome P450s,12 glutathione S-transferases (GSTs),seven carboxylesterases (CarEs)and seven adenosine triphosphate-binding cassette (ABC)transporters.Compared to control,the expression of 22 xenobiotic detoxification unigenes was up-regulated after cycloxaprid application, mainly containing 18 P450s,one GST,two CarEs and one ABC adenosine triphosphate transporter,indicating that the oxidation-reduction was the major reactive process to cy cloxaprid application.Through quantitative real-time polymerase chitin reaction analysis, the expression of selected unigenes (six P450s,one GST and one CarE.)was up-regulated at least two-fold following cycloxaprid treatment,and was generally in agreement with transcriptome data.Compared to the previous midgut transcriptome of P.americana,it looks like the expressive abundance of the xenobiotic detoxification unigenes might be important factors to the detoxifying fimctional differences between foregut and midgut.In conclusion,insect foregut would also play important roles in the physiological processes related to xenobiotic detoxification.

Roles of LmCDA1 and LmCDA2 in cuticle formation in the foregut and hindgut of Locusta migratoria

Chitin deacetylases(CDAs,including CDAI and CDA2)are considered key enzymes for body cuticle formation and tracheal morphogenesis in various insect species.However,their functions in the formation of the cuticular intima of the foregut and hindgut are unclear.Here,we investigated the roles of their respective genes LmCDAI and Lm-CD42 in this process,in the hemimetabolous insect Locusta migratoria.Transcripts of LmCDAI and LmCDA2 were highly expressed both before and after molting in the foregut.In the hindgut,their expression was high only before molting.In both the foregut and hindgut,LmCDA1 protein was localized in the basal half of the chitin matrix(procuti-cle),whereas LmCDA2 was detected in the upper half of the procuticle.K nockdown of LmCDAI by RNA interference(RNAi)in 5th-instar nymphs caused no visible defcts of the hindgut cuticle.By contrast,the chitinous lamellae of the cuticular intima in the foregut of knockdown animals were less compact than in control animals.RNAi against LmCDA2 led to thickening of both the foregut and hindgut cuticles,with a greater number of thinner laminae than in the respective control cuticles.Taken together,our results show that LmCDAI and LmCDA2 have distinct,but overlapping,functions in chitin organization in the foregut cuticle.However,in the hindgut,this process seems independent of LmCDA1 activity but requires LmCDA2 function.Thus,the CDAs reflect tissue-specific differences in cuticular organization and function,which need further detailed molecular and histological analyses for full comprehension.

不同pH对糙海参消化酶活性的影响

研究了不同pH条件下糙海参前肠、中肠及后肠的蛋白酶和淀粉酶比活力的变化.结果表明:1)糙海参前肠和中肠在pH=3,后肠在pH=10时,其蛋白酶的比活力最高;糙海参前肠和中肠蛋白酶的最适pH值在酸性范围,后肠蛋白酶的最适pH值在碱性范围;2)糙海参前肠淀粉酶在pH=3,中肠和后肠淀粉酶在pH=7时,其比活力最高,前肠淀粉酶的最适pH值在酸性范围,中后肠淀粉酶的最适pH值在中性或偏碱性范围;3)糙海参的整个肠道均能消化蛋白质与淀粉,中后肠是淀粉消化的主要场所;4)淀粉酶的比活力高于蛋白酶的比活力,这与其摄食底栖藻与腐屑的食性相吻合.

蝗虫前肠形态及其在分类学上的意义(直翅目:斑腿蝗科)

本文采用体视显微摄影技术对斑腿蝗科４属６种蝗虫前肠形态结构及其分类学意义进行了研究。结果显示，该类群蝗虫前肠形态表现出了一些共性：ＺＩ区具有Ｖ形脊，ＺＩＩ区脊数目少，脊上齿行数较多，ＺＩＶ齿排列方式简单等，与斑腿蝗科其它类群明显不同，这也表明它们的分类关系较近。而在各区脊数目的多少，脊上齿的行数，及一定脊长上齿的个数等方面表现出的差异性，表明种属的特异性。并对伪稻蝗和卵翅蝗的分类地位进行了探讨。

小鼠胚胎呼吸内胚层相关第二生心区的发育

目的探讨小鼠胚胎心流出道分隔过程中,前肠呼吸内胚层与咽前第二生心区细胞发育的形态学关系及机制。方法胚龄9~13d小鼠胚胎标本各6例,连续石蜡切片,用抗转录因子叉头框蛋白A2（Foxa2）、抗胰岛因子1（ISL-1）、抗patched1（Ptc1）、抗patched 2（Ptc2）、抗α-平滑肌肌动蛋白（α-SMA）及抗心肌肌球蛋白重链（MHC）抗体进行免疫组织化学及免疫荧光染色。结果胚龄9~9.5d,前肠腹侧壁ISL-1阳性内胚层局部增厚,呼吸内胚层开始发育,ISL-1阳性间充质细胞紧随其后开始出现在呼吸内胚层周围的基质中。胚龄10~11.5d,呼吸内胚层向动脉囊方向生长延伸向喉-气管沟演变,ISL-1阳性咽前间充质细胞围绕呼吸内胚层呈对称的特征性锥体形结构分布,锥体顶端突入动脉囊腔向主-肺动脉隔发育。在喉-气管沟发育过程中,总能观察到1条实心内胚层细胞索位于其腹侧顶端,Ptc1和Ptc2主要局限于发育中的喉-气管沟及实心细胞索表达,喉-气管沟及实心细胞索的内胚层则位于锥体结构的中心。胚龄12~13d,在流出道水平前肠分隔形成气管,内胚层细胞索逐渐消失,气管上皮逐渐失去Ptc1和Ptc2表达,气管腹侧的ISL-1阳性间充质细胞密度明显减低,并逐渐停止向流出道添加,动脉囊分隔完成。结论呼吸内胚层的分化发育与咽前ISL-1阳性第二生心区细胞的发育聚集密切耦联。音猬因子（SHH）信号系统在呼吸内胚层发育过程中活跃程度较高,发育中的呼吸内胚层可能作为组织中心,通过SHH信号通路诱导ISL-1阳性细胞的聚集,并通过内胚层生长延伸造成的机械牵拉力驱动ISL-1阳性细胞迁移,参与流出道正常形态发生。

四种蝗虫前肠形态的比较研究(直翅目:斑腿蝗科)

采用体视显微摄影技术对斑腿蝗科Ｃａｔａｎｔｏｐｉｄａｅ３属４种（亚科）蝗虫前肠形态进行了分析，并对分布于不同地区的同一亚种进行了观察。结果表明，斑腿蝗亚科几种前肠特征同一性很高，同种不同亚种之间略有差异，相同亚种不同地区之间不存在明显差异。

斜纹夜蛾幼虫肠道不同部位对Zn^(2+)积累作用的比较研究

在人工饲料中添加不同浓度的Zn2+连续胁迫3个世代的斜纹夜蛾Spodoptera litura Fabricius幼虫,采用等离子体原子发射光谱仪检测分析了连续3个世代6龄幼虫肠道不同部位对食物中Zn2+的积累作用。结果表明,Zn2+可在六龄幼虫前、中和后肠中积累,积累量受到食物中Zn2+的浓度和胁迫世代数的双重影响。每个世代6龄幼虫前肠、中肠和后肠中的Zn2+含量均随着饲料中Zn2+浓度增加而增加。六龄幼虫肠道3个不同部位对Zn2+的积累作用依次为前肠<中肠<后肠。而随着胁迫世代数的增加,不同世代6龄幼虫前肠、中肠和后肠中的Zn2+含量表现出显著减少的趋势。因此,植食性昆虫消化道不同部位对食物中Zn2+的积累作用有所不同,并随着胁迫世代数的增加而显著减少。

四种竹蝗前肠形态及其分类学价值的研究（直翅目：网翅蝗科）

用体视双目显微镜对付蝗属４种蝗虫的前肠形态进行了观察和描述（附图４组），根据前肠内刺特征、脊的数目及其排列方式把前肠分为四区：ＺⅠ—ＺⅣ。认为这四区特征及贲门瓣结构是鉴别种的重要特征。并建议将思茅竹蝗和黑翅竹蝗提升为２个种。