Development of the islets, exocrine pancreas, and related ducts in the Nile tilapia, Oreochromis niloticus (Pisces: Cichlidae)

Pancreatic development and the relationship of the islets with the pancreatic, hepatic, and bile ducts were studied in the Nile tilapia, Oreochromis niloticus, from hatching to the onset of maturity at 7 months. The number of islets formed during development was counted, using either serial sections or dithizone staining of isolated islets. There was a general increase in islet number with both age and size. Tilapia housed in individual tanks grew more quickly and had more islets than siblings of the same age left in crowded conditions. The pancreas is a compact organ in early development, and at 1 day posthatch (dph) a single principal islet, positive for all hormones tested (insulin, SST-14, SST-28, glucagon, and PYY), is partially surrounded by exocrine pancreas. However, the exocrine pancreas becomes more disseminated in older fish, following blood vessels along the mesenteries and entering the liver to form a hepatopancreas. The epithelium of the pancreatic duct system from the intercalated ducts to the main duct entering the duodenum was positive for glucagon and SST-14 in 8 and 16 dph tilapia. Individual insulin-immunopositive cells were found in one specimen. At this early stage in development, therefore, the pancreatic duct epithelial cells appear to be pluripotent and may give rise to the small islets found near the pancreatic ducts in 16-37 dph tilapia. Glucagon, SST-14, and some PPY-positive enteroendocrine cells were present in the intestine of the 8 dph larva and in the first part of the intestine of the 16 dph juvenile. Glucagon and SST-14-positive inclusions were found in the apical cytoplasm of the mid-gut epithelium of the 16 dph tilapia. These hormones may have been absorbed from the gut lumen, since they are produced in both the pancreatic ducts and the enteroendocrine cells. At least three hepatic ducts join the cystic duct to form the bile duct, which runs alongside the pancreatic duct to the duodenum.     

Migration of gall stones.

The factors influencing the migration of gall stones are ill understood. Altogether 331 patients undergoing cholecystectomy were studied prospectively. The diameters of the cystic and common bile ducts and of stones in the gall bladder and bile ducts were measured. Increasing pressure was applied to the freshly excised gall bladder in an attempt to evacuate stones through the cystic duct. Stones passed in 33 (60.0%) of patients with choledocholithiasis, 45 (67.2%) of patients with pancreatitis, and 7 (3.2%) of patients without either pancreatitis or choledocholithiasis. Stones migrated in 6 (3.0%) who had a normal cystic duct diameter (less than or equal to 4 mm) and in 46 (32.5%) with a duct over 4 mm diameter. Common bile duct stones were often larger than the diameter of the cystic duct and when reintroduced into the gall bladder would not migrate. The passage of debris (less than or equal to 1 mm) through the cystic duct bore no relation to the presence or absence of choledocholithiasis or a dilated cystic duct. Small stones (1-4 mm diameter) must migrate to initiate and facilitate further migration; some must increase in size in the common bile duct. Increased biliary pressure consequently dilates the duct system retrogradely, allowing larger stones to follow. Patients at risk of stone migration and thereby pancreatitis and jaundice have large ducts that can be detected by ultrasound assessment.     

Studies on the Diet,Feeding Mechanism and Alimentary Tract in Two Closely Related Teleosts,the Freshwater Cottus gobio L. and the Marine Parenophrys bubalis Euphrasen

The diet and feeding mechanism in Cottus gobio and Parenophrys bubalis are described, together with the morphology and histology of the alimentary tract. Both species are sluggish bottom dwelling, carnivorous fish, and are capable of catching and swallowing relatively large prey. The gut is fully differentiated into esophagus, stomach, intestine with pyloric ceca, and rectum. The liver is morphologically separate from the pancreas, and separate bile and pancreatic ducts open into the base of one of the pyloric ceca. The organisation of the gut is well suited to the fishes' mode of life, showing adaptations for taking large meals which may be at irregular intervals.     

Proteins of guinea-pig bile: selective resorption in the gall bladder

We have examined and compared the proteins present in guinea-pig bile as collected either from the common hepatic duct or from the gall bladder. Guinea-pig bile, collected from the common bile duct, has a rather low concentration of protein. Detailed examination shows that the concentrations of actively transported proteins such as immunoglobulin A and haptoglobin.haemoglobin complexes are markedly lower than in rats although the concentrations of proteins which, like albumin, leak non-specifically into bile are similar in the two species. We also find that the protein composition of guinea-pig bile is extensively and selectively modified by resorp-tion of protein in the gall bladder.     

白鲟肝脏和胰脏的组织学与形态学研究

白鲟肝脏较大,可分为左右两大叶及小的中叶,胆囊位于右叶的凹缺内。肝板多由双层细胞构成,肝小叶不明显。肝内毛细胆小管由4个肝实质细胞围成。胰脏有3支,被厚的浆膜。胰岛明显。胰管与胆管汇合后共同开口于小肠最前部背面。对肝、胰实质细胞的显微或亚显微结构进行了描述。     

Age-related changes of elements and relationships among elements in the common bile and pancreatic ducts

To elucidate compositional changes of the common bile and main pancreatic ducts with aging, the authors investigated age-related changes of element contents in the common bile and pancreatic ducts by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students was finished, the common bile ducts and main pancreatic ducts (pancreatic ducts) were resected and the element contents were determined. The Mg content increased significantly only in the pancreatic duct with aging, but the other element contents did not change significantly in both the common bile and pancreatic ducts with aging. Regarding the relationship among the elements, significant direct correlations were found among the contents of Ca, P, S, and Mg in the common bile ducts, with some exceptions between P and either S or Mg contents. In the pancreatic ducts, significant direct correlations were found between S and Mg contents and between P and Na contents. The relationships in the elements between the common bile and pancreatic ducts were examined. It was found that there were significant direct correlations in the Ca, Mg, and Fe contents between the common bile and pancreatic ducts; that is, as Ca, Mg, and Fe increased in the common bile duct, they increased simultaneously in the pancreatic duct.     

Inhibition of pancreatic exocrine secretion and augmentation of the release of gut glucagon-like immunoreactive materials by intraileal administration of bile in the dog

The effect of intraileal instillation of bile, a stimulant of gut glucagon-like immunoreactive materials (gut GLI), on secretin-stimulated pancreatic secretion was examined in anesthetized dogs. Intraileal bile significantly inhibited the flow rate of secretin-stimulated pancreatic secretion. The inhibition of pancreatic secretion was accompanied by an elevation of plasma concentration of gut GLI. Taking the inhibitory effect of glucagon on pancreatic exocrine secretion into consideration, it could be reasonably postulated that gut GLI may be a mediator of bile-induced ileal inhibition of pancreatic exocrine function.     

爪鲵消化系统的解剖学和组织学初步研究

本文报道了爪鲵消化系统的形态学和组织学结构特点。爪鲵口腔底部具有肌肉质的舌,食管很短,胃是呈纺锤形的长囊,胃壁较厚,粘膜厚,胃腺发达。消化管肌层皆为平滑肌,环肌明显多于纵肌。肝脏较大,分左、中、右三叶;有胆囊;胰腺长带状,胰管与胆管汇合后与小肠最前部的十二指肠相连。     

Observations on the gall bladder of juvenile Atlantic salmon Salmo salar L., in relation to feeding

Measurements of gut contents and changes in the volume and colour of bile in the gall bladder of juvenile Atlantic salmon are described for a variety of feeding regimes. The gall bladders of actively feeding fish are virtually empty of bile. When deprived of food, the weight of the gall bladder increases within 6 h and reaches a value equivalent to approximately 20% of the liver weight within 36 h. Bile is pale straw, green and blue in colour after 1, 4 and 6 days of starvation respectively. Stored bile is released from the gall bladder in response to food entering the anterior hind gut.     

Pancreatic Duct Obstruction in the Pig: Light Microscopy of Chronic Pancreatitis

Morphological changes of pancreatic tissue in young pigs caused by surgical ligation of the main pancreatic duct are described. Nineteen animals from 6 to 7 weeks in age were operated on and necropsied 3 or 6 to 8 weeks later. Twelve pigs developed a pronounced chronic pancreatitis with complete exocrine insufficiency. Of the 7 animals failing to develop ectasia of pancreatic ducts, 2 died due to surgical complications. In addition, 3 pigs were sham-operated and served as controls. In macroscopical studies it was observed that in the pronounced pancreatitis cases the ligated duct was greatly dilated by a clear watery fluid. Only remnants of pale and firm grandular tissues were seen around the ectatic ducts. Microscopically, typical changes of chronic pancreatitis were noted. Complete disappearance of acini was followed by ductular cell proliferations. Glandular tissues were divided into lobuli by fibrotic tissues and fat cells. The wall of the main pancreatic duct was greatly thickened and fibrotic, presenting intensely proliferating ductular cells and round cell infiltrates. Furthermore, enlarged endocrine islets surrounded by connective tissue fibres were seen.     

Tyzzeria chalcides N. Sp. from the Ocellated Skink,Chalcides ocellatus1

ABSTRACT A new species of coccidium, Tyzzeria chalcides, is described from the ocellated skink, Chalcides ocellatus, from Egypt. Meronts occur in the epithelial cells of the bile ducts and gamonts within the epithelial cells of the gall bladder. Fully sporulated oocysts are cylindrical (L/W ratio 1.88) without a micropyle, oocyst residuum, or polar granule and contain eight spindle-shaped sporozoites and no sporocysts. Sporulation is completed within the gall bladder lumen. Comparison with other species of the genus found in reptiles indicates that it is a new species.     

Cephalexin Levels in Human Bile in Presence of Biliary Tract Disease

Cephalexin was given to 24 patients before and after operation on the bile ducts and gall bladder. Two patients had obstructive jaundice. Samples of the bile were taken either directly from the gall bladder at operation or via the T-tube. Cephalexin was excreted in the bile, peak levels being obtained after two to three hours. These levels could be raised if probenecid was given concurrently. Higher levels were found in patients with functioning gall-bladders. A trial of cephalexin seems justified for the treatment of typhoid carriers.     

Ampicillin Levels in Human Bile in the Presence of Biliary Tract Disease

Ampicillin levels were measured in the serum and in the bile from both the gall bladder and the common bile duct in patients undergoing surgery for biliary tract diseases. In patients with radiologically non-functioning gall bladders ampicillin was either not present or its concentration was lower than normal. Therapeutic levels were present in the common bile duct of all patients except those with obstruction of the common bile duct. Hence ampicillin fails appreciably to penetrate the obstructed viscus in obstructive biliary tract disease, and it is unlikely to be effective in treating infection associated with this.     

爪鲵消化系统的解剖学和组织学初步研究（图版Ⅵ，下）

本文报道了爪鲵消化系统的形态学和组织学结构特点。爪鲵口腔底部具有肌肉质的舌,食管很短,胃是呈纺锤形的长囊,胃壁较厚,粘膜厚,胃腺发达。消化管肌层皆为平滑肌,环肌明显多于纵肌。肝脏较大,分左、中、右三叶;有胆囊;胰腺长带状,胰管与胆管汇合后与小肠最前部的十二指肠相连。     

Distribution of neurokinin A-like and neurokinin B-like immunoreactivity in human peripheral tissues.

Using specific radioimmunoassay and immunocytochemistry for neurokinin A (NKA) and neurokinin B (NKB), distribution and localization of the two peptides in human peripheral tissues were studied. Both NKA-like immunoreactivity (NKA-LI) and NKB-like immunoreactivity (NKB-LI) were present in the walls of the gut and gall bladder and in the pancreas. In the gut, the values for NKA-LI were 0.56-35.73 pmol/g wet weight, while those in pancreas and gall bladder were 0.64-0.68 and 0.36 pmol/g wet weight, respectively. The values of NKB-LI were 0.45-2.66 pmol/g wet weight in the gut, 0.93-1.65 pmol/g wet weight in the pancreas, and 0.30 pmol/g wet weight in the gall bladder. The immunocytochemical reactivity to both peptides was localized to ganglia of the submucosal and myenteric nerve plexuses in the gut wall, and to neurons in the muscle layer and mucosa of the gut wall. Weak but positive NKA-LI appeared in nerve cells of the pancreas, while NKB-LI was not detectable in the pancreas. Conversely, in the gall bladder wall, NKA-LI was undetectable while a very faint NKB-LI was found in the muscle layer. The localization of NKA corresponded closely to that of NKB in the tissues although the relative concentrations of the peptides varied from organ to organ.     

A novel method for establishment and characterization of extrahepatic bile duct epithelial cells from mice

Culture of extrahepatic bile duct epithelial cells is a useful model to investigate physiology of extrahepatic bile duct epithelia and hepatobiliary disease mechanisms. The aim of this work was to establish and characterize a primary murine extrahepatic bile duct epithelial cell culture. Epithelial cells were isolated from extrahepatic bile ducts of BALB/c mice that were intraperitoneally injected with newborn bovine serum to induce the proliferation of extrahepatic bile ducts’ epithelial cells and cultured on rat tail type I collagen-coated plastic culture flask containing DMEM/HamF12 with 10% FBS and 10 ng/ml epidermal growth factor at 37°C in an incubator with 5% humidified CO₂. The cells showed typical morphologic characteristics of epithelial phenotypes with cobblestone appearance in monolayer within 5–6 d after culture; they were positive against anticytokeratin-19 immunostaining. Transmission electron microscopy showed typical bile duct epithelia with microvilli on the cytomembrance, Golgi complex, massive mitochondria, and rough endoplasmic reticulum in the cytoplasmic. The growth curve of the epithelial cells was determined by a MTT assay which showed a normal sigmoidal growth curve. This culture technique might be a reliable method for isolation, purification, and primary culture of extrahepatic bile duct epithelial cells that can serve as a model for in vitro studies on the pathophysiology of hepatobiliary diseases as well as pharmacological and toxicological targets relevant to hepatobiliary diseases.     

Identification of the taste cell G-protein, α-gustducin, in brush cells of the rat pancreatic duct system

 The major pancreatic excretory ducts have been shown to contain a large number of specialized epithelial cells, named brush cells, that are characterized by an apical tuft of stiff microvilli. The function of pancreatic brush cells is unknown. Because of some structural similarities to taste receptor cells of the tongue, we addressed the question whether pancreatic brush cells contain the taste cell-specific GTP-binding protein, α-gustducin, and hence might be considered to be involved in intraductal chemoreception. By immunostaining, we show that ductal brush cells of the rat pancreatic duct system contain α-gustducin, which is concentrated in the apical tuft of microvilli and is also found along the basolateral cell surface. A further outcome of this study is that brush cells are concentrated in the terminal portions of extralobular ducts and in the major pancreatic duct where brush cells comprise up to 22% of the ductal epithelium. Immunoblotting of the major pancreatic duct revealed a 42-kDa band that comigrated with α-gustducin of the rat tongue. In view of our previous observation that the ductal brush cells are particularly rich in nitric oxide synthase-I, there is reason to assume that these cells might play a role in certain aspects of chemoreceptive signalling. Thus, chemosensory control of pancreatic secretion might occur at two independent sites, the intestine and the terminal portions of the excretory duct system. Accepted: 2 March 1998     

Morphological changes in the rat exocrine pancreas after pancreatic duct ligation

In the present study, morphological changes of the exocrine pancreas in rats after pancreatic duct ligation were examined with light microscopy (hematoxylin-eosin, TUNEL, and PCNA staining) and scanning electron microscopy in order to elucidate the effects of increased pancreatic duct pressure. On the fifth day after pancreatic duct ligation, ductular proliferation, periductal fibrosis, and disappearance of acini were observed. TUNEL and PCNA staining demonstrated many apoptotic acinar cells and proliferating ductal cells immediately after ligation, which reached a maximal number on the 2nd or 3rd day. Tortuous or helical interlobular pancreatic ducts with inner surfaces containing many crater-like depressions and long cilia were found after ligation. These changes were almost identical to those observed in the pancreatic tissue of model chronic pancreatitis rats, WBN/Kob rats, and stroke-prone spontaneously hypertensive (SHRSP) rats. In summary, the morphological changes observed after pancreatic duct ligation were similar to those of chronic pancreatitis, therefore, the characteristic changes of pancreatic ducts observed in chronic pancreatitis may be caused by increased pancreatic duct pressure.