Complete development of Cryptosporidium parvum in a human endometrial carcinoma cell line

Sporozoites of Cryptosporidium parvum, excysted from oocysts isolated from calves, were applied to monolayers of the human endometrial carcinoma cell line RL95-2. Cells were grown as monolayers in 24-well plates at concentrations ranging from 5 x 10(4) to 1 x 10(5) RL95-2 cells per well. At 1 or 7 days postculturing, C. parvum sporozoites (ranging from 1 x 10(5) to 2 x 10(5) were added to the monolayers of RL95-2 cells. The cells were fixed and stained to estimate the extent of parasite colonization. Light microscopy and electron microscopy confirmed the development and replication of C. parvum within the RL95-2 cells. A standardized and reproducible in vitro culture system for C. parvum is necessary to evaluate therapies against cryptosporidiosis.     

Intestinal protection against Strongyloides ratti and mastocytosis induced by administration of interleukin-3 in mice

A case control study of AIDS related sclerosing cholangitis indicates that it has no overall influence on prognosis, but is responsible for a striking reversal of the usual inverse correlation of age and survival in HIV infection. Pain, the principal symptom, was controlled in surviving patients with analgesics alone. Twenty consecutive patients with AIDS related sclerosing cholangitis, defined from at least two characteristic lesions at endoscopic retrograde cholangiopancreatography, were followed for a minimum of 10 months or until death. Median age was 33.5 years (range 27-50). All had abdominal pain; 11 had diarrhoea. Alkaline phosphatase was > 2X normal in 13, but the bilirubin was raised in only three. The median CD4 was 0.024 x 10(9)/l (0.005-0.341). Thirteen had cryptosporidiosis, six had active cytomegalovirus, five had no gastrointestinal pathogen. Three patients are alive without AIDS related sclerosing cholangitis symptoms at 10, 11, and 21 months. Seventeen have died at median 7 (1-23) months. Cytomegalovirus therapy had no apparent influence. The initial CD4 was < 0.11 in all those dying within six months, but correlation of CD4 with prognosis was otherwise poor. Controls, matched for age, CD4, and opportunistic infections had virtually identical overall outcome (median survival 7.5 months) and the expected worse prognosis with increasing age. Increasing age, however, appeared protective in AIDS related sclerosing cholangitis (r = +0.6; p < 0.05): this is not explained by disproportionate degrees of immunosuppression, nor by opportunistic infections.     

Human intestinal epithelial cells respond to Cryptosporidium parvum infection with increased prostaglandin H synthase 2 expression and prostaglandin E2 and F2alpha production

Cryptosporidium parvum is an important cause of diarrhea in humans and several animal species. Prostaglandins play a central role in regulating intestinal fluid secretion in animal models of cryptosporidiosis, but their cellular sources and mechanisms of induction are unclear. Here, we show that C. parvum infection directly activates prostaglandin H synthase 2 expression and prostaglandin E2 and F2alpha production in human intestinal epithelial cells.     

Ano-perineal endometriosis with external sphincter involvement: a rare disorder

BACKGROUND: Cryptosporidiosis has been shown to be a common cause of diarrhoea in both immunocompetent and immunosuppressed individuals. There are very few data on the distribution of Cryptosporidium parvum along the gastrointestinal tract. AIMS: To evaluate the location of Cryptosporidium parasites in the digestive tract of patients with AIDS. METHODS: Gastrointestinal localisation of C parvum was studied in 71 patients with AIDS who underwent upper and/or lower endoscopy with biopsy for chronic diarrhoeal illness and/or other gastrointestinal disorders of unexplained origin. RESULTS: Twenty four individuals (33.8%) were positive for C parvum, of which 16 (88.9%) had parasites in the gastric epithelium. Most patients with gastric localisation of C parvum did not show specific symptoms indicating the presence of this parasite in the stomach. CONCLUSIONS: Gastric involvement in AIDS related cryptosporidiosis is more frequent than expected, but no clear correlation between gastric location and related clinical and pathological features was observed.     

Preferential V beta3 usage by hepatic T lymphocytes in patients with primary sclerosing cholangitis

BACKGROUND/AIMS: Primary sclerosing cholangitis and primary biliary cirrhosis are two biliary destructive disorders characterized by prominent T lymphocyte infiltrates in areas of portal destruction. The specificity of the T cell is determined by the T cell receptor for antigens. The aim of this study was to investigate the preference by which certain V alpha and V beta gene segments are expressed by peripheral and hepatic T cells in primary sclerosing cholangitis and primary biliary cirrhosis. METHODS: The usage of the alpha/beta T cell receptor (TcR) V gene of liver infiltrating lymphocytes and peripheral blood lymphocytes from 12 primary sclerosing cholangitis patients, 10 primary biliary cirrhosis patients and healthy controls was investigated, using alpha/beta TcR V gene product-specific monoclonal antibodies. HLA class II antigen typing with genomic typing technique was done in 11/12 primary sclerosing cholangitis patients. RESULTS: A significant difference between the studied groups of patients was an increase in the expression of V beta3+ T cells in liver tissue from patients with primary sclerosing cholangitis compared to patients with primary biliary cirrhosis and healthy controls (p<0.01). No significant differences were found in the peripheral blood between the three groups. Furthermore, no relation between the different TcR V alpha/beta cells and histological staging and class II antigen association was observed. CONCLUSIONS: Predominant TcR V beta3 gene usage in liver tissue in primary sclerosing cholangitis may indicate the presence of a specific antigen in this tissue with the capacity of selectively driving T cells, utilizing the V beta3 gene segment product, in primary sclerosing cholangitis patients.     

Localization of intraorbital foreign bodies: an improved photoradiographic method

Corynebacterium parvum, strain 10390, whole organisms were shown to bind to the surface of glass-adherent mouse peritoneal exudate cells in vitro. An HCl extract and a lipid extract of the organism were both capable of inhibiting this binding. The attachment of organisms was not affected by trypsin treatment of the cells, indicating that the plasma membrane receptor is not cell-bound antibody in nature. The binding was inhibited by various sugars, most of which are major components of the cell wall of C. parvum. Removal of divalent cations prevented binding. At room temperature some binding occurred in the presence of magnesium ions alone, whereas both calcium and magnesium ions were required at 4 degrees C. The possibility is discussed that the attachment of C. parvum to the plasma membrane of macrophages may lead directly to their activation.     

MR cholangiography in primary sclerosing cholangitis

OBJECTIVE: The purpose of this study was to evaluate the ability of MR cholangiography to reveal the characteristics of biliary abnormalities found in primary sclerosing cholangitis. CONCLUSION: Our results suggest that MR cholangiography could be useful in the diagnosis of primary sclerosing cholangitis. Slightly dilated peripheral bile ducts unconnected to the central ducts in several hepatic segments are a characteristic MR sign of primary sclerosing cholangitis. However, other studies are necessary to establish the usefulness of MR cholangiography in relation to other imaging techniques for evaluating primary sclerosing cholangitis.     

Incidence and prevalence of autoimmune liver diseases

We studied prevalence and incidence of autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis in a Norwegian population. A search in patient databases was performed and medical records from the period 1985-94 were reviewed. Commonly accepted diagnostic criteria were used for inclusion. All three diseases were found to be rare, with a marked female preponderance in primary biliary cirrhosis (female 21/male 0) and to a lesser extent in autoimmune hepatitis (female 20/male 9). The age distribution shows that autoimmune hepatitis and primary sclerosing cholangitis are diagnosed in patients who are on an average 12 years younger than patients with primary biliary cirrhosis. The mean annual incidence was 1.6/100,000 for autoimmune hepatitis, 1.2/100,000 for primary biliary cirrhosis and 0.7/100,000 for primary sclerosing cholangitis. The end of study point prevalence was 14/100,000, 12/100,000 and 5.6/100,000, respectively.     

Sclerosing cholangitis and primary biliary cirrhosis--a disease spectrum?

Sclerosing diseases of the biliary system encompass a spectrum ranging from primary sclerosing cholangitis (usually of the extrahepatic biliary tree) to primary biliary cirrhosis of the intrahepatic bile canaliculi. In a study of 35 patients with primary intra- and extrahepatic biliary sclerosis, age of onset, sex distribution, symptomatology, associated diseases, radiographic abnormalities and chemical profile were considered. The difficulty of differentiating sclerosing cholangitis and biliary cirrhosis from other causes of obstructive jaundice preoperatively was stressed, in addition to points of differential clinical and laboratory findings. The etiology of these entities as well as the possibility that they represent variant clinical manifestations of the same disease process were also considered. Mechanical and pharmacological treatment alternatives that were attempted included drainage procedures, the easiest and most widely used of which was the T-tube. However, this could prove to be a source of infection and should therefore be removed early, inasmuch as cholangitis represents a major cause of morbidity. Steroids have been used with varying effectiveness; subjective improvement was generally attained, although objective improvement has been difficult to document. When choleuretics and cholestyramine were administered, we noted significant palliation. Antibiotics were reserved for treatment of cholangitis. Until the underlying etiology of this rare malignant sclerosing process is found, only symptomatic treatment can be offered.     

Immunopathogenesis of gastrointestinal and hepatobiliary diseases

The largest lymphoid organ in the body is the gut and the gut-associated lymphoid tissue. The mucosal immune system faces many challenges in protecting the body from microbial invasion. Its chief function is to maintain a diverse population of mature lymphocytes capable of responding to foreign antigens. This task is accomplished with a variety of unique features that distinguish the mucosal from the systemic immune system. In addition, the mucosal immune system plays a role in inflammatory bowel disease, Whipple disease, autoimmune gastritis, Helicobacter pylori infection, immunoproliferative small intestinal disease, hepatitis A, B, C, D, E, F, and G, autoimmune hepatitis, primary biliary cirrhosis, progressive sclerosing cholangitis, and vanishing bile duct syndrome.     

Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers

BACKGROUND/AIMS: The pathogenesis of the inflammatory lesion in primary sclerosing cholangitis is unknown. The clinical picture is characterized by i.a. episodes of fever, the cause of which also remains speculative. Previous studies of bacterial isolates in the liver or bile ducts in primary sclerosing cholangitis have had the shortcoming of possible contamination associated with the sampling. The aim of this study was to investigate whether bile and bile duct tissue, obtained under sterile conditions in connection with liver transplantation, contain bacteria. METHODS: We studied bile from bile duct walls and bile collected from the explanted livers of 36 patients with primary sclerosing cholangitis and 14 patients with primary biliary cirrhosis. RESULTS: Positive cultures were obtained from 21 of 36 primary sclerosing cholangitis patients, but from none of the primary biliary cirrhosis patients. The number of bacterial strains was inversely related to the time after the last endoscopic retrograde cholangiography. Treatment with antibiotics or intraductal stent, or the occurrence of fever before liver transplantation did not seem to influence the culture results, whereas antibiotic treatment in connection with endoscopic retrograde cholangiography may possibly have reduced the number of isolates in the cultures. Alpha-haemolytic Streptococci were retrieved as late as 4 years after the last endoscopic retrograde cholangiography. Retrospective analysis of liver laboratory tests after endoscopic retrograde cholangiography did not indicate a deleterious effect of the investigation. CONCLUSIONS: The data suggest that antibiotics should be given routinely in connection with endoscopic retrograde cholangiography. They also raise the question of a possible role of alpha-haemolytic Streptococci in the progression of primary sclerosing cholangitis.     

Mast cell cholangiopathy: another cause of sclerosing cholangitis

A 75-year-old woman with known systemic mastocytosis presented with abdominal pain, ascites, and bile duct thickening on computed tomography and ultrasonography. A liver biopsy specimen showed infiltration with mast cells. Endoscopic retrograde cholangiography showed ductal changes compatible with those found in primary sclerosing cholangitis. Brush cytology of the intrahepatic bile ducts confirmed mast cell infiltration. Systemic mastocytosis can infiltrate the biliary system, producing a cholangiopathy radiographically similar to primary sclerosing cholangitis.     

Biliary tract calculi in primary sclerosing cholangitis

By conventional criteria the diagnosis of primary sclerosing cholangitis (PSC) is excluded if biliary tract calculi are present. OBJECTIVE: To compare patients with sclerosing cholangitis with and without calculi. METHODS: Retrospective review between 8/91 and 9/93 identified 63 patients with sclerosing cholangitis alone (Group A) and 22 patients with sclerosing cholangitis and biliary tract calculi (Group B). The mean follow-up was 13.6 months. Clinical features reviewed were age, sex, associated inflammatory disease (IBD), and clinical presentation. Cholangiographic features compared were site and extent of disease. Endoscopic stone extraction was reviewed for success and complications. RESULTS: Both groups had the following features in common: 1) mean age (45.9 vs 46.3 yr), 2) prevalence of IBD (68.3 vs 72.7%), 3) extent of bile duct strictures (intrahepatic: 28.5% vs 27.2%; extrahepatic: 12.7% vs 13.6%; both: 58.7% vs 54.5%). There were proportionately more women in Group B (45.5% vs 33.3%). Symptomatic presentation (pain, pruritus, jaundice, and cholangitis) was seen more often in Group B: 86.4% compared with Group A: 39.7% (specifically cholangitis was seen in 22.7% vs 4.7%). Among Group B, calculi developed subsequent (mean 40.2 months) after the diagnosis of sclerosing cholangitis in 77.3% of patients. The distribution of calculi was cholelithiasis: 7 (31.8%); choledocholithiasis: 9 (40.9%); and both: 6 (27.2%). Of the patients with choledocholithiasis alone, 78% had undergone previous cholecystectomy. Endoscopic stone extraction was successful in 13 (86.6%) of the patients with choledocholithiasis. Complications included mild pancreatitis in one patient and bleeding from sphincterotomy site in another patient which responded to sclerotherapy. In follow-up, only one patient had recurrent calculi and underwent successful stone extraction. CONCLUSION: We suggest that biliary tract calculi are a part of the spectrum of otherwise typical PSC and therefore their presence should not necessarily exclude the diagnosis.     

Cryptosporidia--who is at risk?

Cryptosporidium parvum is a coccidian parasite originally described a century ago and, until recently, not considered to be a human pathogen. It has a complex life cycle, including both sexual and asexual reproduction, an auto-infectious cycle, and the ability to complete its development within a single host. The transmission form is a robust, environmentally resistant oocyst, excreted in the stool, which can exist for long periods of time in the environment. Because animals, in particular domesticated livestock, are its primary host, human infection is usually zoonotic. Oocysts often find their way into water supplies, and it resists chlorination and is incompletely filtered from processed drinking water supplies, even when filtration is working optimally. Transmission via ingestion of fecally contaminated swimming pool water, food, fomites, and sexual activities facilitating fecal-oral inoculation have been demonstrated. The major target of C. parvum in the host is the intestinal epithelial cell, resulting in diarrhea, sometimes profuse and persistent, although it may also infect other organs such as the gall bladder and lungs. Pathogenesis involves attachment, probably via a sporozoite lectin, invasion, probably involving apical organelles, replication within a parasitophorous vacuole with the host cell membrane, causing cellular dysfunction. Diagnosis is generally made by visualization of the oocyst form in stool by staining methods, the best of which appears to be auramine and fluorescence microscopy. Those at greatest risk are immunocompromised adults and children, especially those with AIDS, children in day care, travelers to endemic regions, dairy or cattle farm workers of their families or contacts, household contacts of cases or carriers, and possibly owners of infected dogs or cats or their neighbors. There is no specific therapy available, however in the immunocompetent host the illness is self-limited, lasting from a few days to 3 weeks, and long term carriage is uncommon. In the immunocompromised host, infection is prolonged, sometimes asymptomatic, but may result in chronic debilitating diarrhea with dehydration, malabsorption and wasting. Public health measures to reduce contamination of water supplies and vigilant surveillance will reduce the risk to populations. Reducing behaviors favoring fecal-oral transmission, such as certain sexual activities, and scrupulous hygiene in the day care setting would also reduce the likelihood of transmission but not eliminate it. Given our lack of knowledge about Cryptosporidium biology and pathogenesis, high priority should be given to research designed to increase our understanding of the organism and improve the chance of developing useful therapeutic or preventative drugs or strategies.     

Genotypic and phenotypic characterization of Cryptosporidium parvum isolates from people with AIDS

Genotypic analysis of Cryptosporidium parvum has demonstrated the presence of two subgroups within the species, whereas biochemical and antigenic characterization have shown more heterogeneity. The clinical relevance of these observations is unknown. C. parvum isolates from people with AIDS were studied with respect to parasite genotypes and virulence in cell monolayers and laboratory animals. Ten of 13 oocyst samples had a characteristic human-associated (H) genotype; 3 had a genotype typical of calf-excreted oocysts (C). Virulence in cell culture was mildly or markedly lower in the 5 isolates tested (4 H and 1 C) compared with the GCH1 reference isolate. H isolates did not infect newborn ICR mice, whereas 1 of the 2 C isolates tested did. These findings reinforce the concept of C. parvum genetic subgroupings that correlate to some extent with infectivity and suggest that additional heterogeneity is present within the subgroups.     

Sclerosing cholangitis and biliary tract calculi--primary or secondary?

The clinical features of 61 patients with sclerosing cholangitis were reviewed. This group included 23 patients with biliary tract calculi, commonly considered as excluding the diagnosis of primary sclerosing cholangitis. The aim of this study was to compare these 23 patients (group A) with 38 patients with sclerosing cholangitis free of calculi (group B). Both groups had the following features in common: (i) age at presentation, (ii) incidence of inflammatory bowel disease, (iii) extent of radiological disease, (iv) prevalence of HLA-B8 and DR3 haplotype, (v) incidence of cholangiocarcinoma, and (vi) progression to hepatic transplantation (mean follow up 49.9 months). All patients in group A were symptomatic at diagnosis compared with 23 of the 38 patients (61%) in group B. Recurrent ascending cholangitis occurred in 12 patients in group A (52%) and two patients (5%) in group B. The similarity between the two groups was maintained when the nine patients in group A who developed calculi after sclerosing cholangitis was diagnosed were excluded. It is concluded that choledocholithiasis is part of the spectrum of primary sclerosing cholangitis and that it is not necessary to invoke choledocholithiasis as the initial lesion of the bile ducts in such patients.     

Na(+)-dependent and -independent Cl-/HCO-3 exchange mediate cellular HCO3- transport in cultured human intrahepatic bile duct cells

Biliary epithelial cells (cholangiocytes) modulate bile fluidity and alkalinity absorbing and/or secreting fluid and electrolytes, particularly HCO3- and Cl-. Mechanisms responsible for transepithelial H+/HCO3- secretion in human cholangiocytes are largely unknown. Human cholangiocytes isolated by enzymatic digestion and immunomagnetic purification from normal liver tissue obtained from reduced grafts used for pediatric liver transplantation were cultured in the presence of human hepatocyte growth factor. Maintenance of cholangiocyte phenotypic features was assessed using markers such as cytokeratin 19, gamma-glutamyltranspeptidase, vimentin, factor VIII-related antigen, desmin, epithelial membrane antigen (EMA), and human epithelial antigen (HEA) 125. Intracellular pH (pHi) transients were measured microfluorimetrically 2'7'-Bis(2-carboxyethyl)-5,6, carboxyfluorescein-acetossimethylester (BCECF). In the absence of HCO3-, pHi recovery from an intracellular acid load (ammonia pre-pulse technique) was Na(+)-dependent and amiloride-inhibitable. No Na(+)-independent recovery was recorded even after stimulation with agents raising intracellular cyclic adenosine monophosphate (cAMP) concentrations. In the presence of HCO3-, recovery from an intracellular acid load required Na+, but was only partly inhibited by amiloride. In these conditions H+ extrusion was inhibited by 4,4-diisothiocyan atostilben-2,2-disulfonic acid (DIDS) and by intracellular Cl- depletion. Acute removal of extracellular Cl induced a pHi alkalinization that was inhibited by DIDS. pHi recovery from an intracellular alkaline load (isohydric CO2 changes) was Cl(-)-dependent and DIDS-inhibitable. Administration of agents raising intracellular cAMP concentrations increased both Na(+)-dependent and Na(+)-independent Cl-/HCO-3 exchange activity. Stimulation of Cl-/HCO3- exchange activity was not prevented by the Cl- channel inhibitor 5'-nitro-2(2)-phenylpropyl-amino-benzoate(NPPB). In conclusion, human cholangiocytes possess two acid extruders (Na+/H+exchanger and Na(+)-dependent Cl-/HCO3- exchange) and an acid loader (Cl-/HCO3- exchange), whereas no evidence was found for cAMP activated H(+)-ATPase. Bicarbonate influx is thus mainly mediated by Na-dependent Cl-/HCO3- exchange, whereas Na+:HCO-3 cotransport is not active in the physiological range of pHi. Stimulation of Na(+)-independent Cl-/HCO3- exchanger by cAMP does not require activation of Cl- conductances. These mechanisms may underlay hormone-regulated biliary HCO3- secretion in the human biliary tree.     

Ursodeoxycholic acid does not improve the clinical course of primary sclerosing cholangitis over a 2-year period

BACKGROUND: Ursodeoxycholic acid has been shown to be a useful agent in the clinical management of patients with primary biliary cirrhosis and autoimmune chronic active hepatitis. Its efficacy is presumed to be based upon its ability to act as a detergent and to incite a choleresis. Recent additional data suggest it also reduces HLA antigen expression on liver and biliary epithelial cells and impairs T cell reactivity. METHODS: A randomized controlled study of 59 patients with primary sclerosing cholangitis was performed over a 24 months period with 3 groups being studied. Group I consisted of 20 patients who were given ursodeoxycholic acid 300 mg orally twice a day; group II consisted of 19 patients who were given colchicine 0.6 mg orally BID; and group III was an untreated medical control group. All three groups were seen at regular 3-month intervals and had quarterly, annual and terminal studies performed to assess their disease status. RESULTS: No difference between groups was evident after two full years of therapy when parameters of liver injury, liver function, liver size and hepatic copper content were compared between groups. Similarly, no difference in ERCP findings was evident between groups either at entry or after two years of therapy. CONCLUSIONS: These data suggest that ursodeoxycholic acid is no better than colchicine or simple medical follow-up. Thus, neither ursodeoxycholic acid or colchicine can be considered to be effective therapies for primary sclerosing cholangitis.     

When your patient doesn''t want to leave

This is case report concerning secondary caustic sclerosing cholangitis following scolecide with concentrated sodium chloride solution (30%) during operation on a liver echinococcus cyst with involvement of the extrahepatic biliary apparatus only. Hepatojejunostomy is performed. Histological study of the liver demonstrates evidence of severe cholangitis, purulent cholangiolitis and suspected secondary biliary cirrhosis. In conclusion, it is stressed that dynamic postoperative follow-up of patients is mandatory to make early diagnosis of the complication and undertake operative treatment anticipating the development of a cirrhotic process. The search for new, effective scolicides, not damaging the biliary apparatus and hepatic parenchyma, is strongly recommended.     

A role for host phosphoinositide 3-kinase and cytoskeletal remodeling during Cryptosporidium parvum infection

Cryptosporidium parvum preferentially infects epithelial cells lining the intestinal mucosa of mammalian hosts. Parasite development and propagation occurs within a unique intracellular but extracytoplasmic parasitophorous vacuole at the apical surface of infected cells. Parasite-induced host cell signaling events and subsequent cytoskeletal remodeling were investigated by using cultured bovine fallopian tube epithelial (BFTE) cells inoculated with C. parvum sporozoites. Indirect-immunofluorescence microscopy detected host tyrosine phosphorylation within 30 s of inoculation. At >30 min postinoculation, actin aggregates were detected at the site of parasite attachment by fluorescein isothiocyanate-conjugated phalloidin staining as well as by indirect immunolabeling with monoclonal anti-actin. The actin-binding protein villin was also detected in focal aggregates at the site of attachment. Host cytoskeletal rearrangement persisted for the duration of the parasitophorous vacuole and contributed to the formation of long, branched microvilli clustered around the cryptosporidial vacuole. The phosphoinositide 3-kinase inhibitor wortmannin significantly inhibited (P < 0.05) C. parvum infection when BFTE cells were pretreated for 60 min at 37 degreesC prior to inoculation. Similarly, treatment of BFTE cells with the protein kinase inhibitors genistein and staurosporine and the cytoskeletally acting compounds 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazapine, cytochalasin D, and 2,3-butanedione monoxime significantly inhibited (P < 0.05) in vitro infection at 24 h postinoculation. These findings demonstrate a prominent role for phosphoinositide 3-kinase activity during the early C. parvum infection process and suggest that manipulation of host signaling pathways results in actin rearrangement at the site of sporozoite attachment.