Prominent hepatic ductular reaction induced by Oschmarinella macrorchis in a Hubbs' beaked whale Mesoplodon carlhubbsi, with biological notes.

Beaked whales are among the least known group of cetaceans, and information regarding their pathology and parasitology is especially scarce. We describe a case of significant parasitism by a trematode found in the liver of an adult male Hubbs' beaked whale Mesoplodon carlhubbsi that stranded in Hokkaido, Japan. Post-mortem examinations revealed a localised area of discolouration restricted to the hilar region of the left hepatic lobe, where spindle-shaped trematodes occupied the dilated and hypertrophic bile ducts. Histologically, the intrahepatic bile ducts were characterised by adenomatous hyperplasia with goblet cell metaplasia of the biliary epithelium. Findings in the adjacent hepatic parenchyma included pseudocarcinomatous ductular reactions obliterating hepatocytes, a histomorphology not previously reported in marine mammals. Morphological identification of the trematode corresponded to Oschmarinella macrorchis, which has only been reported once in a Stejneger's beaked whale, M. stejnegeri. PCR amplification and sequencing analyses of the parasite's mtDNA ND3, 18S and 28S rRNA regions generated novel gene sequences. Environmental contaminant levels were measured to explore its potential relationship with the parasitism but there was no conclusive association. A high level of polychlorinated biphenyl (30000 ng g-1 lipid weight) was detected in the blubber of this individual, when compared to those of 3 other male Hubbs' beaked whales stranded in Japan. Stomach contents were also analysed, indicating the presence of various squid species and unidentified fish. Our results contribute to the knowledge of a little-known beaked whale and provide evidence for the first time of the pathobiological response caused by O. macrorchis.

A Case of Biliary Ascariasis in Korea.

Biliary ascariasis is still the leading cause of surgical complication of ascariasis, though its incidence has been dramatically reduced. Herein, we report a case of biliary ascariasis for the purpose of enhancing awareness of parasitic infections as a possible cause. A 72-year-old male visited the emergency room of Dankook University Hospital on 12 July 2015, complaining of right-upper-quadrant pain. By endoscopic retrograde cholangiopancreatography (ERCP), a tubular filling defect in the right hepatic duct was detected. The defect was endoscopically removed and diagnosed as an adult female of Ascaris lumbricoides worm, of 30 cm length. Upon removal of the worm, the pain subsided, and the patient was discharged without any complication. When treating cases of biliary colic, physicians should not neglect biliary ascariasis as the possible cause.

Tetraphyllidean plerocercoids from Western Mediterranean cetaceans and other marine mammals around the world: a comprehensive morphological analysis.

Tetraphyllidean plerocercoids have occasionally been reported in marine mammals, but they have rarely been described in detail, and the ecological significance of these infections is unclear. We described plerocercoids collected from the mucosa of the terminal colon and rectum, the anal crypts, and the hepatopancreatic ducts of 7 striped dolphins Stenella coeruleoalba, 1 Cuvier's beaked whale Ziphius cavirostris, and 3 Risso's dolphins Grampus griseus from the Spanish Mediterranean. We also examined undescribed plerocercoids from 3 cetacean species from the Atlantic and the Pacific. All plerocercoids had a lanceolate body, and a scolex with an apical sucker and 4 sessile monolocular bothridia. The bothridia had free posterior edges and an accessory sucker at their anterior end. Under light microscopy, the bothridia of some Mediterranean specimens looked bilocular without accessory suckers, but a true accessory sucker was observed in histological sections. A principal component analysis revealed 2 stable clusters of specimens along the first principal component regardless of host species. These "large" and "small" morphotypes are thought to represent early migratory stages of Phyllobothrium delphini and Monorygma grimaldii. The similarity in scolex morphology, the observation of plerocercoids buried in intestinal regions close to the sites where M. grimaldii and P. delphini occur, and the coexistence of all larval forms in the same individual hosts would support this hypothesis. Future molecular analysis may confirm it.

Biliary papillary hyperplasia with clonorchiasis resembling cholangiocarcinoma.

Infection by the liver fluke Clonorchis sinensis is very common in the Far East. It causes low grade inflammatory changes and proliferation in the biliary tree. Initially there is desquamation of the biliary epithelium, followed by hyperplasia and adenomatous proliferation. Cholangiocarcinomas are potential long term complications. We present a case of biliary papillary hyperplasia with clonorchiasis resembling cholangiocarcinoma in a 69-yr-old Korean man. Early recognition of biliary hyperplasia and treatment of Clonorchis sinensis is important to prevent development of cholangiocarcinoma, especially in the Far East.

Experimental cholecystitis in goats caused by mature Fasciola gigantica.

Mature Fasciola gigantica obtained from naturally infected cattle were surgically transferred into the gallbladders of six fluke-free goats. Two of the goats died at two and 19 weeks and the remaining four were slaughtered at 12, 48, 48 and 80 weeks after the transfer. Nine of 20 transferred F gigantica were recovered from the gallbladder and common hepatic duct of the experimental goats. The walls of gallbladders and bile ducts were thickened by epithelial proliferation, fibrosis and mononuclear cell infiltration. Large numbers of globule leucocytes were present in the epithelium of gallbladders and common hepatic ducts as well as in minute intrahepatic bile ducts. Very few mast cells were observed in these locations. Globule leucocytes in two goats were positive for argentaffin reaction with Gomori hexamine silver stain. The proliferative cholecystitis in experimental goats was similar to adenomatous cholecystitis in cattle naturally infected with fascioliasis. Globule leucocytes had no obvious deleterious effects on the parasites.