Production and characterization of antibody against Opisthorchis viverrini via phage display and molecular simulation

In this study, a key issue to be addressed is the safe disposal of hybridoma instability. Hybridoma technology was used to produce anti–O. viverrini monoclonal antibody. Previous studies have shown that antibody production via antibody phage display can sustain the hybridoma technique. This paper presents the utility of antibody phage display technology for producing the phage displayed KKU505 Fab fragment and using experiments in concomitant with molecular simulation for characterization. The phage displayed KKU505 Fab fragment and characterization were successfully carried out. The KKU505 hybridoma cell line producing anti–O. viverrini antibody predicted to bind to myosin was used to synthesize cDNA so as to amplify the heavy chain and the light chain sequences. The KKU505 displayed phage was constructed and characterized by a molecular modeling in which the KKU505 Fab fragment and -O. viverrini myosin head were docked computationally and it is assumed that the Fab fragment was specific to -O. viverrini on the basis of mass spectrometry and Western blot. This complex interaction was confirmed by molecular simulation. Furthermore, the KKU505 displayed phage was validated using indirect enzyme-linked immunosorbent assays (ELISA) and immunohistochemistry. It is worthy to note that ELISA and immunohistochemistry results confirmed that the Fab fragment was specific to the -O. viverrini antigen. Results indicated that the approach presented herein can generate anti–O. viverrini antibody via the phage display technology. This study integrates the use of phage display technology together with molecular simulation for further development of monoclonal antibody production. Furthermore, the presented work has profound implications for antibody production, particularly by solving the problem of hybridoma stability issues.

Misleading findings of liver-specific MR contrast agent for radiological diagnosis of cysto-biliary communication in hydatid cysts

OBJECTIVE

To investigate the effectiveness of gadoxetic acid-enhanced magnetic resonance cholangiopancreatography (CE-MRCP) and T2-weighted half-Fourier acquisition single-shot turbo spin-echo (T2W HASTE) sequences for diagnosis of cysto-biliary communication in hydatid cysts compared to surgical results.

METHODS

Preoperative abdominal magnetic resonance imaging examinations of patients who underwent surgery for hepatic hydatid cysts were reviewed by two radiologists retrospectively. A total of 45 patients with hydatid cysts were included. Of 45, 27 also had CE-MRCPs. T2W HASTE sequences and CE-MRCPs were investigated separately for cysto-biliary communication. The relationship between radiological and surgical results was analyzed. The interobserver agreement was evaluated.

RESULTS

Of 45 hydatid cysts, there were surgically proven 21 cysts without biliary communications and 24 cysts with biliary communications. All cysts with biliary communications were shown on T2W HASTE sequences. There was no leakage of gadoxetic acid into these cysts (n = 24). Sensitivity, specificity, negative predictive value, positive predictive value (PPV), and accuracy of diagnosis of cyst with biliary communication on T2W HASTE sequences was 100%, 63.64%, 100%, 66.67%, and 78.95%, respectively. Specificity (77.78%), PPV (87.50%), and accuracy (91.30%) were increased in ≥ 10 cm cysts. There was almost perfect interobserver agreement (K = 0.81-1.00).

CONCLUSION

Leakage of gadoxetic acid inside the cyst indicates biliary communication. However, the lack of leakage does not rule out cysto-biliary communication. When biliary communication is clearly shown on T2W HASTE sequences, it should be reported as cysto-biliary communication even if there is no leakage of gadoxetic acid into the cyst on CE-MRCP.

Co-occurrence of opisthorchiasis and diabetes exacerbates morbidity of the hepatobiliary tract disease

Complications arising from infection with the carcinogenic liver fluke Opisthorchis viverrini cause substantial morbidity and mortality in Thailand and adjacent lower Mekong countries. In parallel, the incidence rate of diabetes mellitus (DM) is increasing in this same region, and indeed worldwide. Many residents in opisthorchiasis-endemic regions also exhibit DM, but the hepatobiliary disease arising during the co-occurrence of these two conditions remains to be characterized. Here, the histopathological profile during co-occurrence of opisthorchiasis and DM was investigated in a rodent model of human opisthorchiasis in which diabetes was induced with streptozotocin. The effects of excretory/secretory products from the liver fluke, O. viverrini (OVES) on hepatocyte and cholangiocyte responses during hyperglycemic conditions also were monitored. Both the liver fluke-infected hamsters (OV group) and hamsters with DM lost weight compared to control hamsters. Weight loss was even more marked in the hamsters with both opisthorchiasis and DM (OD group). Hypertrophy of hepatocytes, altered biliary canaliculi, and biliary hyperplasia were more prominent in the OD group, compared with OV and DM groups. Profound oxidative DNA damage, evidenced by 8-oxo-2'-deoxyguanosine, proliferating cell nuclear antigen, and periductal fibrosis characterized the OD compared to OV and DM hamsters. Upregulation of expression of cytokines in response to infection and impairment of the pathway for insulin receptor substrate (IRS)/phosphatidylinositol-3-kinases (PI3K)/protein kinase B (AKT) signaling attended these changes. In vitro, OVES and glucose provoked time- and dose-dependent effects on the proliferation of both hepatocytes and cholangiocytes. In overview, the co-occurrence of opisthorchiasis and diabetes exacerbated pathophysiological damage to the hepatobiliary tract. We speculate that opisthorchiasis and diabetes together aggravate hepatobiliary pathogenesis through an IRS/PI3K/AKT-independent pathway.

Fasciola hepatica-a "Diver" in the Biliary Tree

Fasciola hepatica is an endemic trematode that affects millions of people worldwide. The human being can be an accidental host through consumption of contaminated food or water. The authors present a case of hepatic fascioliasis in a 69-year-old Portuguese woman who recently traveled from Egypt, Brazil, and India.

Carbonyl stress phenomena during chronic infection with Opisthorchis felineus

Infection with the fish borne liver fluke Opisthorchis felineus is common in the Eastern Europe (Ukraine, European part of Russia), Northern Asia (Siberia) and Central Asia (Northern Kazakhstan). Better understanding of the molecular pathogenesis of the biliary tract and liver during chronic opisthorchiasis can be expected to improve protection against and management of complications of this disease. We hypothesize that infection with O. felineus associates with formation of methylglyoxal and carbonyl stress in the liver and hence here we investigated the glyoxalase system and the receptor for advanced glycated end products (RAGE) in the liver of hamsters infected with this liver fluke. Expression of mRNA encoding glyoxalase 1 decreased at 8weeks of the infection and catalytic activity as well decreased at 8 and 12weeks after infection, and the expression of the glyoxalase 2 decreased until 36week post-infection, which associated with the decreasing activity of the enzyme at 8 and 12weeks post-infection. Glutathione levels in infected livers had decreased at week 8, whereas up-regulation of RAGE at mRNA levels was seen for the extended duration of the experimental infection of the hamsters. This outcome supported the notion of hepatic dicarbonyl stress during chronic opisthorchiasis. The inhibition of the glyoxalase system and accumulation of methylglyoxal at the early stages of the infection may underpin development of insulin resistance during opisthorchiasis.

Levels of 8-OxodG Predict Hepatobiliary Pathology in Opisthorchis viverrini Endemic Settings in Thailand

Opisthorchis viverrini is distinct among helminth infections as it drives a chronic inflammatory response in the intrahepatic bile duct that progresses from advanced periductal fibrosis (APF) to cholangiocarcinoma (CCA). Extensive research shows that oxidative stress (OS) plays a critical role in the transition from chronic O. viverrini infection to CCA. OS also results in the excision of a modified DNA lesion (8-oxodG) into urine, the levels of which can be detected by immunoassay. Herein, we measured concentrations of urine 8-oxodG by immunoassay from the following four groups in the Khon Kaen Cancer Cohort study: (1) O. viverrini negative individuals, (2) O. viverrini positive individuals with no APF as determined by abdominal ultrasound, (3) O. viverrini positive individuals with APF as determined by abdominal ultrasound, and (4) O. viverrini induced cases of CCA. A logistic regression model was used to evaluate the utility of creatinine-adjusted urinary 8-oxodG among these groups, along with demographic, behavioral, and immunological risk factors. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive accuracy of urinary 8-oxodG for APF and CCA. Elevated concentrations of 8-oxodG in urine positively associated with APF and CCA in a strongly dose-dependent manner. Urinary 8-oxodG concentrations also accurately predicted whether an individual presented with APF or CCA compared to O. viverrini infected individuals without these pathologies. In conclusion, urinary 8-oxodG is a robust ‘candidate’ biomarker of the progression of APF and CCA from chronic opisthorchiasis, which is indicative of the critical role that OS plays in both of these advanced hepatobiliary pathologies. The findings also confirm our previous observations that severe liver pathology occurs early and asymptomatically in residents of O. viverrini endemic regions, where individuals are infected for years (often decades) with this food-borne pathogen. These findings also contribute to an expanding literature on 8-oxodG in an easily accessible bodily fluid (e.g., urine) as a biomarker in the multistage process of inflammation, fibrogenesis, and infection-induced cancer.

Opisthorchis viverrini is a food-borne helminth infection that drives a strong inflammatory response in the bile duct that can result in bile duct fibrosis and bile duct cancer (intrahepatic cholangiocarcinoma). Extensive research shows that oxidative stress (OS) plays a critical role in chronic O. viverrini infection transitioning to cancer in the bile duct. OS also results in a modified DNA lesion, referred to as 8-oxodG, excreted in the urine, where it can be detected by an antibody-based test. We measured the concentrations of 8-oxodG in the urine of O. viverrini-infected individuals who had developed bile duct fibrosis or bile duct cancer and compared levels of this metabolite in urine to O. viverrini infected individuals who did not have bile duct fibrosis or cancer in Northeastern Thailand. We determined bile duct fibrosis by ultrasonography and bile duct cancer by immunohistochemistry on resected liver tissue. We then built a statistical model to quantify how well urinary 8-oxodG predicted bile duct fibrosis and bile duct cancer in O. viverrini-infected individuals. We found that individuals with elevated levels of 8-oxodG in urine had a greater probability of developing bile duct fibrosis or bile duct cancer from O. viverrini infection. This association occurred in a strongly dose-dependent manner: in other words, the O. viverrini-infected individuals who had the highest concentration of urinary 8-oxodG also had the highest risk of presenting with bile duct fibrosis or bile duct cancer. In summary, measuring levels of 8-oxodG in the urine offers a unique opportunity to develop a candidate biomarker for advanced O. viverrini induced hepatobiliary pathologies such as fibrosis and cancer. The findings also confirm our previous observations that severe liver pathology occurs early and asymptomatically in residents of O. viverrini endemic regions, where individuals are infected for years (often decades) with this food-borne neglected tropical diseases (NTD) pathogen.

Comparative studies on animal models for Opisthorchis viverrini infection: host interaction through susceptibility and pathology

Syrian hamsters and gerbils are animal models for Opisthorchis viverrini infection. In both models, the parasites develop into adults with different pathologies of the hepatobiliary system. However, no comparative pathological studies have yet been completed. We therefore investigated host interaction through the susceptibility and pathological changes of Syrian hamsters and gerbils infected with 50 O. viverrini metacercariae for 30, 60, and 90 days post-infection. Animals were sacrificed at each time point for comparative study. Susceptibility and infectivity were investigated through worm burden. Parasite morphology and reproductive organs were stained with carmine and observed under light microscopy. Reproductive organs and eggs per worm were counted to confirm worm maturity. Bile acid components of both animal groups were analyzed by thin-layer chromatography. The results showed that infection in gerbils was of greater severity than in Syrian hamsters by observation of bile obstruction, enlargement of the gallbladder and common bile duct, and generation of fibrosis and cirrhosis. The worm burden of infected gerbils was lower than that observed in Syrian hamsters. Infectivity in both Syrian hamsters and gerbils was 100% with infection by 50 metacercariae; whereas with 10 metacercariae, the infectivity in gerbils was zero to very low, but still 100% in Syrian hamsters. The largest body size of worms, and the largest ovary and testes areas, was correlated with eggs per gram of feces and eggs per worm. The bile acid components cholic acid and chenodeoxycholic acid were undetectable in gerbils. The present study suggests that although Syrian hamsters, usually the host selection for an animal model, are susceptible to O. viverrini infection, infected gerbils produce worms that mature more rapidly, have larger body sizes, and more fully developed reproductive organs; this may be caused by the difference in bile acid components.

[Clinical and functional changes in the biliary tract in patients with psoriasis concurrent with chronic opisthorchiasis]

OBJECTIVE

to study the clinical and functional changes in the biliary tract in patents with psoriasis concurrent with chronic opisthorchiasis (CO).

SUBJECTS AND METHODS

60 patients with psoriasis concurrent with CO, 45 patients with psoriasis without helminthism, 30 with CO, and 15 healthy individuals were examined. Chromatic fractional duodenal intubation, dynamic hepatobiliscintigraphy, and ultrasound study of the liver and gallbladder were used. The concentrations of cholesterol, bile acids, bilirubin, total lipids and phospholipids in bile were measured. A number of relative indices, such as cholate-cholesterol coefficient (CCC), Thomas-Hofmann index, and Rubens index were calculated.

RESULTS AND DISCUSSION

The patients with psoriasis with CO were found to have signs of mainly hypermotor dyskinesia of the biliary tract, as well as increased bile lithogenicity (lower CCC, and increases in the Rubens index and Thomas-Hofmann index).

CONCLUSIONS

The clinical and functional changes found in the biliary tract of the patients with psoriasis concurrent with CO show it necessary to perform antihelminthic therapy in this group of patients.

MRI findings of hepatobiliairy fascioliasis

Hepatobiliary fascioliasis is an uncommon disease. Depending on the stage of the disease it can present with a wide variability of clinical symptoms. Knowledge of the specific radiological findings of the disease is crucial to shorten the time to final diagnosis, which is usually long. We report a case of hepatobiliary fascioliasis in a 26-year-old woman with intermittent abdominal discomfort showing non specific findings at computed tomography and ultrasound. A hypothesis of an infectious disorder was formulated based on MRI findings and a recent history of travelling. Final diagnosis was confirmed by subsequent serology testing.

[Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) infections in population of some regions of the Ob River Basin]

The incidence of Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) infections among people living in several regions of the Ob River basin in the West Siberia has been assesed in this work. Our results suggest that Metorchis bilis infection was common in many of the serologically tested people. Moreover, this helminth was obtained from the biliary ducts of humans in autopsy.

Endoscopic management of intrabiliary-ruptured hepatic hydatid cyst

BACKGROUND/AIM

Intrabiliary rupture of hepatic hydatid cyst causes serious morbidity and mortality. These patients are usually managed surgically. We evaluated the feasibility and outcome of an alternative method of treatment of these patients.

METHODS

Seven patients with ruptured hepatic hydatid into the biliary tract underwent endoscopic treatment consisting of endoscopic sphincterotomy, cyst material extraction and hypertonic saline lavage via nasocystic catheter.

RESULTS

Median age of patients was 40 years (range 17-50 years) with a male:female ratio of 2:5. Abdominal pain, jaundice and fever were seen in all patients. Six out of seven patients were positive for hydatid serology. All patients were successfully treated by endoscopic sphincterotomy, clearance of cyst material and hypertonic saline lavage. On a follow-up of 6 months to 4 years (median, 3.5 years), ultrasonography, computed tomography of the abdomen and magnetic resonance imaging of the abdomen showed a complete cure. There were no complications related to procedure.

CONCLUSIONS

This study demonstrates endoscopic treatment as one of the therapeutic options of ruptured hepatic hydatid cyst into the biliary tract.

Acute pancreatitis caused by tapeworm in the biliary tract

Taeniasis is a helminthic infection endemic in southeast Asia, including Taiwan. Recent studies suggest that Asian Taenia is a new subspecies of Taenia saginata and has been renamed as Taenia saginata asiatica. It is usually asymptomatic or associated with only mild gastrointestinal symptoms. We report the case of a 52-year-old woman with acute epigastric pain and vomiting. Her levels of amylase and lipase were significantly elevated on admission. Gastrointestinal endoscopy showed proglottids of a tapeworm in the papilla of the duodenum. The epigastric pain subsided and the amylase and lipase levels decreased after removal of the tapeworm by endoscopy and anthelminthic treatment. Although parasites are not an uncommon cause of pancreatitis, especially in disease-endemic areas, it is rare for Taenia to cause acute pancreatitis.

Surgical management of spontaneous intrabiliary rupture of hydatid liver cysts

PURPOSE

The most common complication of hydatid liver cysts is spontaneous rupture into the biliary tract. This study was conducted to evaluate the surgical management of spontaneous intrabiliary rupture of a hydatid liver cyst in 41 patients.

METHODS

The preoperative diagnosis was confirmed by ultrasound in all 41 patients, 37 of whom were jaundiced.

RESULTS

According to Gharbi's classification, 39% of the cysts were type III and they ranged from 3 to 18 cm in diameter, with a mean diameter of 9 cm. The mean total bilirubin and alkaline phosphatase values were 6.3 mg/dl and 450 IU, respectively. Partial cystectomy, cholecystectomy, and common bile duct exploration were performed in all patients. In seven patients, the visible biliary duct within the cyst cavity was sutured with 2/0 silk. Intraoperative cholangiography was performed in all patients, and choledochoscopy was performed in 11 patients. A T-tube was inserted after the biliary tract content was thought to have been totally cleaned out in 38 patients (93%), and a choledochoduodenostomy was performed in 3 patients (7%). An external biliary fistula developed in five patients, persisting for 11-25 days. The fistulae healed within a mean period of 5 days after endoscopic sphincterotomy (EST). For patients without a fistula the mean hospitalization time was 8 days and there was no mortality.

CONCLUSION

These results suggest that when a hydatid liver cyst ruptures into the biliary tract, common bile duct exploration should be conducted using intraoperative cholangiography and choledochoscopy. If the biliary tract is cleaned of all cystic content, T-tube drainage should be sufficient, but EST is an effective technique for treating persistent extended external biliary fistulae.

Non-invasive management of Ascaris lumbricoides biliary tact migration: a prospective study in 69 patients from Ecuador

Ascariasis is one of the most common helminthic diseases. Its most feared complication is migration into the biliary tree. Some authors recommend immediate duodenoscopy in all cases of biliary migration, with sphincterotomy for the extraction of the parasites, and surgical extraction in case of intrahepatic ascariasis. We followed prospectively 69 patients with ultrasonographical evidence of migration. Initial treatment consisted of intravenous analgesics and antispasmodics, and albendazole 800 mg by mouth. Only patients with persisting symptoms or with high amylasaemia underwent duodenoscopy, with extraction in case of a visible worm. Surgery was limited to cases with persistent or progressive complications. In 97% of our cases the worms disappeared with noninvasive therapy alone. A duodenoscopy was done in 30 (42%) cases; in 10 (14%) a worm was found in the ampulla of Vater and extracted without sphincterotomy. In none of the 6 cases with A. lumbricoides in the intrahepatic biliary tree did the parasite persist. Only one patient required surgical intervention. Treatment of A. lumbricoides migration to the biliary tract should be principally medical. Duodenoscopy with extraction of a visible worm should be limited to cases with persisting pain and/or hyperamylasaemia. Invasive methods like sphincterotomy and surgery should be restricted to patients who do not respond to conservative treatment.

Using pig biliary system, in vivo propagation of Enterocytozoon bieneusi, an AIDS-related zoonotic pathogen

A microsporidian parasite Enterocytozoon bieneusi is the most common microorganism recognized in AIDS patients, and slow scientific progress is attributed to our inability to propagate the parasite. We report upon the development of a system of propagation using the pig biliary system. The parasite spores were continuously detected in the bile samples post onset of spore shedding in the gall bladder, which suggests that this organism maintain persistent infection in the biliary system and that the hepatobiliary tree may represent a reservoir of infection. In conclusion the biliary tree is an adequate niche for the propagation of E. bieneusi. This work has also resulted in the development of a procedure of ultrasound-guided cholecystocentesis for aspirating biles. This is a simple and non-surgical procedure, and creates no signs of clinical complications in the livers and the gall bladders after dozens of separate attempts. Thus, this is a very useful and safe technique for the aspiration of bile from live animals.

Experimental hepatobiliary fascioliasis in rabbits: a radiology-pathology correlation

RATIONALE AND OBJECTIVES

The authors sought to correlate the radiologic findings of hepatobiliary fascioliasis with pathologic features.

METHODS

Serial ultrasound, computed tomography (CT), and magnetic resonance findings in seven rabbits with experimentally induced fascioliasis were obtained every other week. Direct cholangiogram was also obtained after the rabbits were killed. Radiology-pathology correlation was done in specimens.

RESULTS

In the parenchymal phase (an acute phase of parenchymal invasion of a larva), CT showed subcapsular clustered areas of low attenuation. Magnetic resonance appearance was similar in shape but better than CT in characterizing the hemorrhagic nature of the lesion. Ultrasound findings were nonspecific in this phase. In the ductal phase (a stationary phase after residing in the bile duct), CT showed dilatation of central ducts with symmetric periportal hypoattenuation (periportal tracking). Magnetic resonance could not depict mild ductal dilatation. Ultrasound was most valuable in demonstrating the moving worm within the dilated duct. Pathologically, the hepatic parenchymal lesions consisted of a cluster of eosinophilic granulomas with hemorrhagic change (migratory tract of the flukes). Ductal changes were observed predominantly in the central bile ducts. Periportal lymphangiectasia was also noted.

CONCLUSIONS

Computed tomography or magnetic resonance can demonstrate the characteristic evolutionary pattern of fascioliasis that reflects the unique life cycle of Fasciola hepatica. The role of ultrasound, although limited in the parenchymal phase, was most useful in the ductal phase in that it demonstrated the moving worms themselves.

An in vitro model of infection of human biliary epithelial cells by Cryptosporidium parvum

Cryptosporidium parvum infection in the immunosuppressed host is frequently complicated by biliary tract involvement. The recent production of human biliary epithelial cell lines was exploited to develop an in vitro model of biliary cryptosporidiosis. Infection with C. parvum oocysts was detected by IFA and ELISA and confirmed by transmission electron microscopy. Inoculation of monolayers with 10(4) to 5 X 10(5) oocysts/well resulted in a dose-dependent increase in infection. Time-course experiments showed that the number of parasitic stages was maximal at 18-24 h after inoculation. Infection was significantly enhanced by bile at concentrations of 50 and 100 microg/mL and inhibited by 400 microg/mL paromomycin. Infection of human biliary cells with C. parvum can be consistently achieved and monitored by use of IFA or ELISA. This system will be of use in evaluating mechanisms of C. parvum infection and response to therapeutic agents in biliary cryptosporidiosis.

Principles of the surgical approach in human liver cystic echinococcosis

Ultrasonography (USG) has recently contributed much to the diagnostic of hepatic cystic echinococcosis (CE). The use of portable ultrasonograph allowed us to perform a community survey among 9482 people living in a high risk area for CE in the Florida Department (Uruguay). Positive USG results were found in 123 asymptomatic patients. 48 out of 51 USG positive cases were surgically confirmed and 3 were found to be false positive. The results of this survey allowed us to propose a new classification of the echographic imaging based on the parasite's various evolutive and involutive stages. The Echinococcus granulosus cyst size was compared with the parasite's evolutive stages. The cyst's segmentary topography and the related risk of CE is evaluated. The importance of cystic-biliary communication is pointed out and its rational surgical treatment described. Finally, an algorithm is presented facilitating the choice of a rational treatment.

Cytochemical localization of cytochrome c oxidase activity in mitochondria in the tegument and tegumental and parenchymal cells of the trematodes Echinostoma trivolvis, Zygocotyle lunata, Schistosoma mansoni, Fasciola gigantica and Paragonimus ohirai

Cytochrome c oxidase in the mitochondria of the tegument and tegumental and parenchymal cells was examined cytochemically in Echinostoma trivolvis, Zygocotyle lunata, Schistosoma mansoni, Fasciola gigantica and Paragonimus ohirai, trematodes that inhabit different sites in their vertebrate hosts. Clear differences in enzyme activity occurred in the mitochondria of these species, probably reflecting the different energy metabolisms of these worms. Marked aerobic metabolism occurred in S. mansoni and P. ohirai adults that inhabit the host mesenteric veins and the lungs, respectively. The tegument and parenchymal cells of S. mansoni possess relatively few, small mitochondria with tabular cristae which are heavily reactive for cytochrome c oxidase. In P. ohirai, the activity for cytochrome c oxidase in tegumental mitochondria increased gradually from juveniles to adults, reflecting that the respiratory activity increased with growth and the aerobic metabolism is activated when the worms reach the lung. P. ohirai juveniles and adults had two types of mitochondria with different shapes and enzyme activities that were located in two different types of parenchymal cells. The intestinal species, E. trivolvis had mitochondria in the basal aspect of the tegument, and some variations in enzyme activity of their mitochondria in the tegumental and parenchymal cells were observed, suggesting that they possess both aerobic and anaerobic metabolic systems. Z. lunata that live in rodent caeca are devoid of mitochondria in the tegument and have many characteristic mitochondria with undeveloped cristae in the parenchymal cells. Mitochondria of F. gigantica showed weak or no activity for cytochrome c oxidase, suggesting that the worm is well-adapted to an anaerobic environment in the host bile duct.

Acute pancreatitis caused by biliary ascaris in pregnancy

Ascaris lumbroicoides is the most prevalent human parasite worldwide. Although usually asymptomatic, ascaris is responsible for a variety of severe complications such as intestinal obstruction, cholangitis, or hepatitis, which are caused by worm migration. This article is the second known case report of pancreatitis caused by biliary ascaris during pregnancy. We also review the pathophysiology of this disease and review the various treatment modalities available for pregnant patients. We believe that because of the growing influx of immigrants from endemic areas into the United States, the clinician needs a basic understanding of the etiology, diagnosis, and treatment of biliary ascarasis.

Biliary ascariasis: report of a case

A 64-year-old female aborigine presented with acute cholangitis and obstructive jaundice for three days. Abdominal ultrasonography showed dilatation of the common bile duct, intrahepatic ducts and a linear tubular structure in the common bile duct. Duodenoscopy showed a live Ascaris protruding through the papilla of Vater, which was retracted endoscopically. Cholangitis improved dramatically after worm extraction and nasobiliary drainage. Endoscopic retrograde cholangiography revealed another worm retained in the common bile duct. It disappeared spontaneously from the common bile duct one week later. The barium study of the intestine showed multiple filling defects in the terminal ileum. A total of five worms passed into the stool after treatment with pyrantel pamoate.

Ascaris-induced acute pancreatitis

The incidence, clinical disease and outcome of acute pancreatitis caused by ascariasis in an endemic area of Kashmir, India, was studied prospectively. Ascariasis was an aetiological factor in 59 of 256 patients (23.0 per cent) with acute pancreatitis. Worms had invaded the bile duct in 51 patients, the pancreatic duct in four and both ducts in four. Pancreatitis was mild in 46 patients and severe in 13. Associated pyogenic cholangitis was present in eight. Acute complications occurred in 11 patients. Endoscopic retrograde cholangiopancreatography (ERCP) was performed in all cases within 72 h of admission and delineated ascarides in the duodenum invading the ampullary orifice (44 patients), in the bile duct (55) and in the pancreatic duct (eight). At ERCP, worms were extracted from the ampullary orifice and removed via the mouth of 33 patients with intractable epigastric pain, leading to rapid relief of symptoms. The eight patients with pyogenic cholangitis underwent endoscopic nasobiliary drainage to decompress the bile ducts; worms were extracted from the bile duct of three of these patients using a Dormia basket. A total of 56 patients recovered from acute illness with a combination of conservative and endoscopic treatment; the other three required emergency surgery. At a mean(s.d.) follow-up of 19(7) months, ten patients showed symptomatic worm reinvasion of the biliary tree. The overall mortality rate was 3 per cent.

Efficacy of albendazole and mebendazole against Hymenolepis microstoma and Hymenolepis diminuta

An investigation of the chemotherapeutic effects of 2 anthelmintics, albendazole (ABZ, methyl 5-[propylthio]benzimidazole-2- carbamate) and mebendazole (MBZ, methyl 5-[benzoyl]benzimidazole-2-carbamate), on Hymenolepis microstoma and Hymenolepis diminuta in experimentally infected mice and rats is reported. Single (50 mg/kg) or multiple daily oral doses (50 mg kg-1 day-1 for 3 consecutive days) of MBZ had no effect on H. microstoma; at necropsy, the drug treated mice harbored appreciable numbers of the parasite in the bile duct and biliary passages. ABZ was also inactive when given as a single oral 50 mg/kg dose on day 27 PI. Better results were obtained when ABZ was administered at a dosage of 50 mg kg-1 day-1 for 3 consecutive days; the reduction in worm burden obtained with this treatment regimen was 50%. These results are in marked contrast to those obtained with the same anthelmintics against enteral H. diminuta in rats which succumbed at lower dosages. A review was made of the published reports on the pharmacokinetic behavior of these benzimidazole carbamate anthelmintics and a hypothesis for the inactivity of MBZ against H. microstoma is proposed.