太平洋丽龟的生理结构研究

目的研究太平洋丽龟的生理结构及特点,为我国开展海龟保育和科学研究提供参考。方法对1只误捕致死的太平洋丽龟进行解剖,观察其循环系统、消化系统、呼吸系统和泄殖系统并测量记录。结果太平洋丽龟心脏位于胸部正中、稍偏右;食管内壁分布许多锥状突起;小肠长240cm,占整个消化系统管道总长的53.1%,消化道总长与体长的比值（简称肠长比）为5.35;精巢1对,阴茎长30cm,可推断为成年的雄龟。结论太平洋丽龟的生理结构估计与其肉食性有关,这对开展人工驯养繁育和物种保护具有重要意义。     

Swallowed foreign bodies

Of 98 swallowed foreign bodies demonstrated, 71 with fate definitely known are reported. Seventeen of 20 foreign bodies in the esophagus had esophagoscopic removal. Only two of 51 foreign bodies in the gastrointestinal tract had laparotomy, while 49 were spontaneously passed. Early esophagoscopic removal of foreign bodies lodged in the esophagus and conservative management of foreign bodies which have passed the esophagogastric junction are recommended. Laparotomy is rarely indicated in the management of swallowed foreign bodies, although various observers are not in full agreement as to the circumstances in which "watchful waiting" is advisable nor as to how long it is permissible to wait for spontaneous passage. In 20 of 71 cases of swallowed foreign bodies, the objects were in the esophagus at the time the patient was first examined. Esophagoscopic removal was carried out in 17 cases. In two cases a foreign body was passed per rectum and in one was vomited. Laparotomy for removal was done in only two of the 51 cases in which the foreign body was already in the stomach or bowel at the time of examination, and in one of them the operation probably could have been avoided.     

Diseases and causes of mortality among sea turtles stranded in the Canary Islands, Spain (1998-2001)

This paper lists the pathological findings and causes of mortality of 93 sea turtles (88 Caretta caretta, 3 Chelonia mydas, and 2 Dermochelys coriacea) stranded on the coasts of the Canary Islands between January 1998 and December 2001. Of these, 25 (26.88%) had died of spontaneous diseases including different types of pneumonia, hepatitis, meningitis, septicemic processes and neoplasm. However, 65 turtles (69.89%) had died from lesions associated with human activities such as boat-strike injuries (23.66%), entanglement in derelict fishing nets (24.73%), ingestion of hooks and monofilament lines (19.35%), and crude oil ingestion (2.15%). Traumatic ulcerative skin lesions were the most common gross lesions, occurring in 39.78% of turtles examined, and being associated with Aeromonas hydrophila, Vibrio alginolyticus and Staphylococcus spp. infections. Pulmonary edema (15.05%), granulomatous pneumonia (12.90%) and exudative bronchopneumonia (7.53%) were the most frequently detected respiratory lesions. Different histological types of nephritis included chronic interstitial nephritis, granulomatous nephritis and perinephric abscesses, affecting 13 turtles (13.98%). Ulcerative and fibrinous esophagitis and traumatic esophageal perforation were the most frequently observed lesions in the esophagus, being associated in the majority of the cases with ingestion of fishing hooks. Larval nematodes of the Anisakidae family caused gastritis in 15 turtles (16.13%). Necrotizing and/or granulomatous hepatitis were the lesions most commonly observed in the liver (27.95%). Traumatic lesions included necrotizing myositis (10.75%) mainly caused by entanglement in fishing nets or boat-strikes, and amputation of 1 or 2 flippers (25.81%) by netting. Traumatic erosions and/or fractures of the carapace/plastron mainly caused by boat-strikes were also observed (26.88%). Eye lesions included heterophilic keratoconjunctivitis, ulcerative keratitis and heterophilic scleritis, affecting 7 turtles (7.53%).     

Cytodiagnosis of in situ and early carcinoma of the upper gastrointestinal tract

Three cases of adenocarcinoma of the stomach, two in situ and one superficially invasive, and one of superficially invasive squamous-cell carcinoma of the esophagus are presented to illustrate the problems encountered in the diagnosis of early lesions of the upper gastrointestinal (GI) tract and the contribution that cytodiagnosis can make. The symptomology and roentgenographic findings in these cases were largely nonspecific. While endoscopic biopsies were repeatedly negative in three of the four cases, endoscopic brushing cytology consistently indicated the presence of a malignancy. Surgery was finally performed on the basis of the cytologic findings, confirming the presence of early malignancy. The cytologic findings, with histologic correlations, are presented in an effort to define some specific criteria for the diagnosis of early malignancy of the upper GI tract.     

Gastrointestinal function and structure in HIV-positive patients.

We examined 19 patients (17 men) with human immunodeficiency virus (HIV) infection and gastrointestinal symptoms to determine whether those symptoms were due to either a gastrointestinal tract infection or a defect in mucosal absorption because of an enteropathy. The erythrocyte folate and serum vitamin B12 levels were within normal limits in all of the patients. The serum ferritin level was elevated in 12. The xylose absorption test results were abnormal in 8 of the 13 patients able to complete the study. None of the duodenal aspirates yielded a pathogen. Light microscopy revealed nonspecific lymphocytic inflammation without infection in the stomach (in seven patients), the esophagus (in five), the duodenum (in two) and the rectum (in two). However, biopsy specimens were positive for Candida albicans in the esophagus (four patients), cytomegalovirus in the esophagus (one) and the rectum (two), Helicobacter pylori in the antrum (two), Treponema infection in the rectum (two) and Mycobacterium avium-intracellulare in the small intestine (one). Only three patients had a normal series of biopsy specimens. All of the patients had similar ultrastructural changes at the epithelial-stromal junction of the antral glands and in the intestinal crypts. We conclude that abnormal biochemical and endoscopic findings are common in HIV-positive patients with gastrointestinal symptoms. Defects in carbohydrate absorption and ultrastructural changes may be responsible for some aspects of HIV enteropathy.     

Expression of constitutive nitric oxide synthase in rat and human gastrointestinal tract.

The aim of this study was to determine the expression of constitutive NO synthases (ecNOS and bNOS) at the protein level in rat and human gastrointestinal tract. We established a quantitative Western blotting method for detection and quantification of ecNOS and bNOS in both species. Human gastric fundus was further analyzed by immunohistochemistry. EcNOS expression at the protein level could be quantified in different organs of the rat gastrointestinal tract and in human gastric mucosal biopsies. Immunohistochemistry of gastric fundus revealed that immunoreactivity for ecNOS was localized mainly in the endothelium of small vessels. In rats, expression of bNOS at the protein level was highest in esophagus. By means of immunohistochemistry of human gastric fundus, immunoreactivity was detected mainly in the plexus of Auerbach. We conclude that isoforms of constitutive nitric oxide synthase can be identified and quantified at the protein level both in rat and human gastrointestinal tract. The presence of bNOS in nerve tissue supports previous observations that NO serves as a transmitter in non-adrenergic, non-cholinergic nerves in human esophagus and stomach. The observation that ecNOS has been found mainly in endothelial cells suggests the involvement of NO in the regulation of mucosal blood flow.     

Physiological ramifications for loggerhead turtles captured in pelagic longlines

Bycatch of endangered loggerhead turtles in longline fisheries results in high rates of post-release mortality that may negatively impact populations. The factors contributing to post-release mortality have not been well studied, but traumatic injuries and physiological disturbances experienced as a result of capture are thought to play a role. The goal of our study was to gauge the physiological status of loggerhead turtles immediately upon removal from longline gear in order to refine our understanding of the impacts of capture and the potential for post-release mortality. We analysed blood samples collected from longline- and hand-captured loggerhead turtles, and discovered that capture in longline gear results in blood loss, induction of the systemic stress response, and a moderate increase in lactate. The method by which turtles are landed and released, particularly if released with the hook or line still attached, may exacerbate stress and lead to chronic injuries, sublethal effects or delayed mortality. Our study is the first, to the best of our knowledge, to document the physiological impacts of capture in longline gear, and our findings underscore the importance of best practices gear removal to promote post-release survival in longline-captured turtles.     

牛蛙胃肠胰系统内分泌细胞的免疫组织化学鉴定与定位

应用过氧化物酶标记的链霉卵白素(S-P)免疫组织化学方法对牛蛙(Rana catesbeiana)胃肠胰系统5种内分泌细胞进行了鉴定与定位.在消化道中检测到了5-羟色胺(5-HT)、生长抑素(SS)、胃泌素(Gas)和胰高血糖素(Glu)细胞.5-HT细胞主要分布于胃幽门部和空肠,食道中偶见.SS细胞主要分布于胃,幽门部较密集,小肠各段少量,直肠和食道偶见.Gas细胞主要分布于小肠各段,胃和直肠中偶见,食道中未检测到.Glu细胞主要分布于胃和直肠,小肠各段偶见,食道中未检测到.在胰腺中检测出了5-HT、SS、Gas、Glu和胰多肽(PP)细胞.SS、Glu和PP细胞数量较多,成簇分布于胰岛中,5-HT和Gas细胞少量,散在分布于胰腺腺泡之间.胃腺部和胰腺内分泌细胞多呈圆形、椭圆形或形态不规则,有的可见明显胞突伸向邻近细胞,胃肠道上皮中的内分泌细胞多呈梭形、楔形或锥形,有的可见明显胞突伸向消化腔.与其它两栖动物相比,牛蛙胃肠胰系统内分泌细胞的存在与分布有一些共性,也存在着种间差异.     

Rabbit esophagus metabolizes arachidonic acid predominantly via a lipoxygenase pathway

Eicosanoids modulate the response of gastrointestinal mucosa to noxious stimuli. Though these compounds have been extensively investigated in the stomach, their role in the esophagus has received less attention. Thus, the metabolism of 14C-arachidonic acid by homogenates of rabbit esophageal mucosa was investigated. The major metabolites formed and separated by TLC and HPLC had the chromatographic characteristics of (percent conversion follows each metabolite) 6-keto-prostaglandin F1 alpha (3.80 +/- 1.15), prostaglandin F2 alpha (2.05 +/- 0.37), prostaglandin E2 (5.92 +/- 1.65) and 12-hydroxyeicosatetraenoic acid (26.03 +/- 4.58). Indomethacin, a cyclooxygenase inhibitor, caused a significant decrease in prostaglandin formation without affecting 12-hydroxyeicosatetraenoic acid. BW755C, a combined cyclooxygenase-lipoxygenase inhibitor, dramatically decreased formation of all metabolites. It is concluded that esophageal mucosa metabolizes arachidonic acid primarily to a lipoxygenase derived product. This is the most abundantly produced eicosanoid yet described in the gastrointestinal tract. The importance of this compound to esophageal function is unknown but its presence suggests that future studies of eicosanoids in the esophagus should focus on lipoxygenase metabolites.     

变色树蜥消化道5-羟色胺细胞的免疫组织化学定位

用免疫组织化学ABC法,应用5-羟色胺(5-HT)特异性抗血清,对变色树蜥(Calotes versicolor)消化道内含有5-HT的内分泌细胞进行了免疫组织化学的定位研究和形态学观察。结果显示,5-HT细胞在变色树蜥消化道的各个部位均有分布,分布密度近似呈“M”形,其中以空肠分布密度最高,胃体次之,食管最低。5-HT细胞的形态多样,呈圆形、椭圆形、锥体形、长锥体形等,其中胃、幽门和直肠以圆形和椭圆形为主,小肠则以长锥体形为主,其细长突起指向肠腔或固有膜;细胞分布于上皮基部、上皮细胞之间、腺泡上皮细胞之间或固有膜内;多数细胞以内分泌功能为主,少数细胞具有外分泌功能。比较分析表明,5-HT细胞分布型可能与动物的食性有关。     

hERG1 Potassium Channel Expression in Colorectal Adenomas: Comparison with Other Preneoplastic Lesions of the Gastrointestinal Tract

Preneoplastic lesions represent a useful target for early diagnosis and follow-up of gastrointestinal malignancies. hERG1 channel expression was tested by immunohistochemistry (IHC) in a cohort of colorectal adenoma samples belonging to Italian subjects. Overall, hERG1 was expressed in 56.5% of cases with both high staining intensity and a high percentage of positive cells. Moreover, hERG1 was expressed in a higher percentage of dysplastic adenomas with respect to hyperplastic lesions, and the proportion of positive samples further increased in patients with high-grade dysplasia. Comparing hERG1 expression in other preneoplastic lesions of the GI tract (gastric dysplasia and Barrett’s esophagus), it emerged that in all the conditions, hERG1 was expressed with a diffused pattern, throughout the cell, with variable staining intensity within the samples. The highest expression was detected in gastric dysplasia samples and the lowest in Barrett’s esophagus at similar levels observed in colorectal adenomas. Our results show that hERG1 is aberrantly expressed in human preneoplastic lesions of the gastrointestinal tract and has a different pattern of expression and role in the different sites. Overall, the detection of hERG1 expression in preneoplastic lesions could represent a novel diagnostic or prognostic marker of progression in the gastrointestinal tract.     

The relationship between gut contents and supercooling capacity in hatchling painted turtles (Chrysemys picta)

Painted turtles (Chrysemys picta) typically spend their first winter of life in a shallow, subterranean hibernaculum (the natal nest) where they seemingly withstand exposure to ice and cold by resisting freezing and becoming supercooled. However, turtles ingest soil and fragments of eggshell as they are hatching from their eggs, and the ingestate usually contains efficient nucleating agents that cause water to freeze at high subzero temperatures. Consequently, neonatal painted turtles have only a modest ability to undergo supercooling in the period immediately after hatching. We studied the limit for supercooling (SCP) in hatchlings that were acclimating to different thermal regimes and then related SCPs of the turtles to the amount of particulate matter in their gastrointestinal (GI) tract. Turtles that were transferred directly from 26 degrees C (the incubation temperature) to 2 degrees C did not purge soil from their gut, and SCPs for these animals remained near -4 degrees C for the 60 days of the study. Animals that were held at 26 degrees C for the duration of the experiment usually cleared soil from their GI tract within 24 days, but SCPs for these turtles were only slightly lower after 60 days than they were at the outset of the experiment. Hatchlings that were acclimating slowly to 2 degrees C cleared soil from their gut within 24 days and realized a modest reduction in their SCP. However, the limit of supercooling in the slowly acclimating animals continued to decline even after all particulate material had been removed from their GI tract, thereby indicating that factors intrinsic to the nucleating agents themselves also may have been involved in the acclimation of hatchlings to low temperature. The lowest SCPs for turtles that were acclimating slowly to 2 degrees C were similar to SCPs recorded in an earlier study of animals taken from natural nests in late autumn, so the current findings affirm the importance of seasonally declining temperatures in preparing animals in the field to withstand conditions that they will encounter during winter.     

Cytologic features of premalignant glandular lesions in the upper gastrointestinal tract

The cytologic findings in 13 endoscopic brushing specimens from biopsy-proven premalignant glandular lesions (PGLs) of the upper gastrointestinal tract were reviewed retrospectively. The specimens were from ten patients: three with dysplasia in Barrett's esophagus, four with gastric adenomas and three with duodenal adenomas. One dysplasia in Barrett's esophagus and four adenomas (two gastric and two duodenal) had coexisting adenocarcinomas. Most pure PGLs were characterized cytologically by cohesive three-dimensional clusters of cells with more-or-less uniformly enlarged nuclei and an increased nuclear/cytoplasmic ratio. Crowding and molding were present within these clusters; however, the cells were arranged in a somewhat orderly or palisading fashion, instead of entirely haphazardly. In cases of carcinoma coexisting with adenoma or dysplasia, the atypical cells tended to be more pleomorphic and dyshesive. In one specimen from an adenocarcinoma arising in an adenoma, the adenomatous and carcinomatous components could be distinguished cytologically.     

Dietary exposure to harmful algal bloom (HAB) toxins in the endangered manatee (Trichechus manatus latirostris) and green sea turtle (Chelonia mydas) in Florida,USA

Florida is a hotspot for cyano- and microalgal harmful algal blooms (HABs) with annual red-tide events off-shore and blooms of Lyngbya spp. commonly observed in both marine and freshwater environments. This region also provides extensive foraging habitat for large populations of herbivorous green turtles (Chelonia mydas) and manatees (Trichechus manatus latirostris). The exposure of aquatic organisms to HAB toxins is not well known and whilst acute exposures are better understood, the vulnerability of aquatic animals to chronic exposure from multiple HAB toxins over prolonged periods has rarely been addressed. This study aimed to identify the presence of toxic compounds produced by HAB species commonly found in Florida (brevetoxins, okadaic acid, saxitoxins and Lyngbya toxins) in tissues and gut samples from manatee and green sea turtles that stranded in Florida, USA. Muscle, liver and alimentary tract samples were opportunistically collected from 14 manatees and 13 green turtles that stranded on the Florida shoreline between December 2003 and February 2006. Samples from each animal were assessed for the presence of brevetoxin, okadaic acid, lyngbyatoxin-A and saxitoxin. Nine (64%) manatees and 11 (85%) turtles were found to have been exposed to one or more of the HAB toxins. Okadaic acid and saxitoxin were only found in alimentary tract samples, whereas brevetoxin was more widely distributed. No lyngbyatoxin-A was observed in any tissue samples. The majority of turtles (13) stranded on the Atlantic coast between St. Johns and Monroe counties, with one on the Gulf coast at Bay County, whereas nine manatees were stranded on the Gulf coast between Levy and Lee counties, with the remaining five between Volusia and Brevard counties on the Atlantic coast. This HAB toxin screen has identified that a large proportion of a random sample of turtles and manatees that stranded in Florida in 2003–2006 were exposed to HAB toxins. Most of the concentrations measured were low, and the toxins were directly linked to the death of only three of these animals. However, the presence of these compounds, and in some cases the presence of multiple HAB toxins in individual animals, indicates that turtles and manatees in Florida are exposed to deleterious compounds at sub-lethal levels in their environment, which could ultimately compromise their health.     

黑龙江草蜥消化道5-羟色胺免疫活性内分泌细胞的分布与形态学观察

应用5-HT抗血清,以ABC(avidin-biotin-peroxidase complex)免疫组织化学方法,对黑龙江草蜥(Takydromus amurensis)消化道内5-HT免疫反应阳性内分泌细胞的分布及形态进行了观察。结果显示：5-HT阳性细胞从食管到直肠的消化道各段均有分布。细胞分布密度呈波浪式,食管、胃幽门部和回肠是其细胞分布密度的高峰。5-HT阳性细胞的形态呈圆形、椭圆形、锥体形、梭形等,其中以圆形和椭圆形为主;广泛分布于上皮基部、上皮细胞之间、腺泡上皮及腺泡之间,有时可见于固有膜内。因此作者认为5-HT阳性细胞具有内、外、旁分泌三种作用途径并且它的密度分布可能与其食性、生活环境等有关。     

Nitric oxide synthase in the enteric nervous system of the guinea-pig: a quantitative description

The distribution and abundance of nitric oxide synthase (NOS)-containing neurons and their terminals in the gastrointestinal tract of the guinea-pig were examined in detail using NADPH diaphorase histochemistry and NOS immunohistochemistry. NOS-containing cell bodies were found in the myenteric plexus throughout the gastrointestinal tract and in the submucous plexus of the stomach, colon and rectum. NOS-containing neurons comprised between 12% (in the duodenum) and 54% (in the esophagus) of total myenteric neurons. In the ileum, NOS neurons represented 19% of total myenteric neurons. Most of the NOS neurons throughout the gastrointestinal tract possessed lamellar dendrites and a single axon. NOS-containing terminals were abundant in the circular muscle, including that of the sphincters, but were rare in the longitudinal muscle, except for the taeniae of the caecum. The muscularis mucosae of the esophagus, stomach, colon and rectum received a medium to dense innervation by NOS terminals. Within myenteric ganglia, NOS-containing terminals were extremely sparse in the esophagus, stomach and duodenum, common in the ileum and distal colon and extremely dense in the proximal colon and rectum. The submucous plexus in the ileum and large intestine contained a sparse plexus of NOS-containing terminals. NOS terminals were not observed in the mucosa of any region. We conclude that throughout the gastrointestinal tract of the guinea-pig, NOS neurons are inhibitory motor neurons to the circular muscle; in the ileum and large intestine, NOS neurons may also function as interneurons.     

Is the hook of muroid rodent's sperm related to sperm train formation?

Competition between spermatozoa of rival males to gain fertilizations has led to a wide array of modifications in sperm structure and function. Sperm cells of most muroid rodents have hook‐shaped extensions in the apical–ventral tip of the head, but the function of this structure is largely unknown. These ‘hooks’ may facilitate aggregation of spermatozoa in so‐called ‘trains’, as an adaptation to sperm competition, because sperm in trains may swim faster than free‐swimming cells. However, there is controversy regarding the role of the hook in train formation, and in relation to whether it is selected by sperm competition. We examined spermatozoa from muroid rodents with varying levels of sperm competition to assess whether (i) sperm aggregates are common in these taxa, (ii) presence of a hook relates to the formation of sperm aggregations, and (iii) formation of sperm aggregations is explained by sperm competition. Our analyses in 25 muroid species revealed that > 92% of spermatozoa swim individually in all species, with the exception of the wood mouse, Apodemus sylvaticus, which has ~50% spermatozoa swimming freely. Species with hooked spermatozoa had higher sperm competition levels and longer sperm than species whose sperm lack a hook. Neither the presence of hook nor sperm competition levels were related to the percentage of sperm in aggregations. Thus, (i) sperm aggregates in muroid rodents are an exceptional trait found only in a few species, (ii) evolution of the sperm hook is associated to sperm competition levels, but (iii) the hook is unlikely to be related to the formation of sperm aggregates. The evolutionary significance of the sperm head hook thus remains elusive, and future studies should examine potential roles of this pervasive structure in sperm's hydrodynamic efficiency and sperm–female tract interactions.     

The buccopharyngeal mucosa of the turtles (testudines)

Gross and histological examination of all extant families of turtles revealed that the buccopharyngeal mucosa is morphologically highly varied. The tongues of aquatic species have small lingual papillae or lack them entirely, while terrestrial species have tongues with numerous glandular papillae. The pharynx and the esophagus also have papillae in some species. These either facilitate swallowing in which case they are long, pointed, keratinized, and occur commonly in marine turtles, or they are vascular and nonkeratinized, facilitate respiratory gas exchange and are found in the Trionychidae, Dermatemyidae, and Carettochelyidae. The morphology of the buccopharyngeal mucosa of turtles reflects their diet, feeding behavior, habitat, and relationships. Convergence in the morphology of the buccopharyngeal mucosa occurs among families, especially among the Emydidae and other familes of turtles. Intergeneric parallelism is also seen within the Emydidae.     

To Eat or Not to Eat? Debris Selectivity by Marine Turtles

Marine debris is a growing problem for wildlife, and has been documented to affect more than 267 species worldwide. We investigated the prevalence of marine debris ingestion in 115 sea turtles stranded in Queensland between 2006-2011, and assessed how the ingestion rates differ between species (Eretmochelys imbricata vs. Chelonia mydas) and by turtle size class (smaller oceanic feeders vs. larger benthic feeders). Concurrently, we conducted 25 beach surveys to estimate the composition of the debris present in the marine environment. Based on this proxy measurement of debris availability, we modeled turtles' debris preferences (color and type) using a resource selection function, a method traditionally used for habitat and food selection. We found no significant difference in the overall probability of ingesting debris between the two species studied, both of which have similar life histories. Curved carapace length, however, was inversely correlated with the probability of ingesting debris; 54.5% of pelagic sized turtles had ingested debris, whereas only 25% of benthic feeding turtles were found with debris in their gastrointestinal system. Benthic and pelagic sized turtles also exhibited different selectivity ratios for debris ingestion. Benthic phase turtles had a strong selectivity for soft, clear plastic, lending support to the hypothesis that sea turtles ingest debris because it resembles natural prey items such as jellyfish. Pelagic turtles were much less selective in their feeding, though they showed a trend towards selectivity for rubber items such as balloons. Most ingested items were plastic and were positively buoyant. This study highlights the need to address increasing amounts of plastic in the marine environment, and provides evidence for the disproportionate ingestion of balloons by marine turtles.