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N Kapel

Publications and source records attributed to N Kapel.

At least 37 records · Page 2Linked to original sources
PubMed1996

Kinetics of mucosal ileal gamma-interferon response during cryptosporidiosis in immunocompetent neonatal mice.

The kinetics of serum and ileal interferon-gamma (IFN-gamma) content were determined during recovery from cryptosporidiosis in NMRI suckling mice. A total of 60 mice aged 4 days were inoculated by intragastric gavage with 10(4) cryptosporidia (n = 30) or phosphate-buffered saline (n = 30). Six animals per group were killed on days 0, 3, 6, 9 and 13 postinoculation. Blood samples and ileum were collected. Experimental infection was followed by a rise in parasite load in the ileum starting on day 3 postinfection, which peaked at day 6 postinoculation. Ileal IFN-gamma levels increased rapidly in parasitized mice from day 3 to day 6, then fell rapidly. These levels were significantly higher than the control values (day 3 P < 0.05, days 6 and 9 P < 0.001). IFN-gamma secretion began before parasite excretion, but the curves of these two parameters correlated positively. Recovery from cryptosporidiosis in immunocompetent neonatal mice is thus associated with an early and marked increase in ileal IFN-gamma content.

Animals↗
PubMed1996

Antineutrophil cytoplasmic autoantibodies in autoimmune liver and inflammatory bowel diseases.

Perinuclear antineutrophil cytoplasmic autoantibodies have been described in inflammatory bowel diseases and in primary sclerosing cholangitis. Because the data concerning their occurrence are conflicting, we have used indirect immunofluorescence on ethanol-fixed neutrophils to test the sera from a large population of 382 patients with various liver and digestive diseases: in particular, from 27 patients with primary sclerosing cholangitis, 105 patients with autoimmune chronic active hepatitis, 30 patients with primary biliary cirrhosis and 124 patients with inflammatory bowel disease. The prevalence of the perinuclear antineutrophil cytoplasmic autoantibodies was 37% in ulcerative colitis and 15% in Crohn's disease. They would not be helpful in the differential diagnosis between these two inflammatory bowel diseases. Within the group of autoimmune liver diseases, perinuclear antineutrophil cytoplasmic autoantibodies were detected in 44% of sera from patients with primary sclerosing cholangitis and in 36% of sera from patients with type I autoimmune active hepatitis, but not in primary biliary cirrhosis. When primary sclerosing cholangitis was associated with an inflammatory bowel disease, the prevalence of these autoantibodies was 60%. They were 88% specific for primary sclerosing cholangitis and 86% specific for type I autoimmune active hepatitis. Despite their moderate sensitivity and specificity in primary sclerosing cholangitis, they remain the only serologic marker of this autoimmune liver disease. Moreover, they turned out to be a more sensitive marker for inflammatory bowel disease with associated primary sclerosing cholangitis.

Adolescent↗
PubMed1995

Inefficacy of intestinal secretory immune response to Cryptosporidium in acquired immunodeficiency syndrome.

BACKGROUND/AIMS: An alteration of the secretory immune response has been forwarded to explain frequent and chronic mucosal infections in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to explore the intestinal immunoglobulin (Ig) secretions in patients with AIDS and their relationships to cryptosporidiosis. METHODS: Patients with AIDS and enteric cryptosporidiosis (n = 12), other enteric infections (n = 10), and no identifiable enteric pathogen (n = 10) and human immunodeficiency virus-seronegative controls (n = 18) were studied. The number of intestinal IgA and IgM plasma cells of the duodenal lamina propria mucosa and total and anti-Cryptosporidium IgA, IgM, and IgG were measured in serum and feces. RESULTS: Although not significantly increased, the number of IgA and IgM plasma cells was greater in patients with AIDS (n = 20) than in controls (n = 5). In feces, total IgA outputs and specific anti-Cryptosporidium IgA levels were significantly higher in patients with AIDS and cryptosporidiosis than in the two other groups of patients with AIDS (P < 0.05 and P < 0.01, respectively) and controls (P < 0.001 and P < 0.01, respectively). Total fecal IgM output and specific anti-Cryptosporidium IgM coproantibodies were increased only in the Cryptosporidium-infected patients relative to the controls (P < 0.05). CONCLUSIONS: Despite the development of pathogen-specific mucosal antibody responses, patients with AIDS and cryptosporidiosis fail to clear the parasite.

Acquired Immunodeficiency Syndrome↗
PubMed1995

A high-yield outbred suckling mouse model of cryptosporidiosis.

Outbred suckling mice (NMRI strain) were used as hosts. They were initially inoculated with oocysts of human origin, and subsequently with parasites recovered from the mouse ileal mucosa. Cryptosporidia were counted in an aliquot of whole-ileum homogenate. Parasite load was expressed as cryptosporidia per centimeter of ileum. Serial passage of C. parvum in NMRI mouse litters led to a gradual amplification of parasite burden relative to animals initially inoculated with the human isolate.

Animals↗
PubMed1994

Intestinal lipid metabolism in suckling rats infected with Giardia duodenalis.

We carried out a quantitative and qualitative analysis of intestinal digestion of neutral lipids in suckling rats infected with Giardia duodenalis. Total lipids were measured after extraction from the contents of the stomach, proximal and distal small bowel, caecum and colon. Amounts gradually fell from the stomach to the colon and were identical in infected animals and controls, although high values were occasionally found in the caecum of infected rats. Relative glyceride quantities were determined by means of high-performance thin-layer chromatography. Triglycerides were absent from the distal small bowel, and only free fatty acids and cholesterol were present in the caecum, reflecting normal digestion of neutral lipids in infected suckling rats. Our results suggest that G. duodenalis does not impair intestinal fat digestion in suckling rats.

Animals↗
PubMed1994

[Time-resolved fluorometry: principles and applications in clinical biology].

Time-resolved fluorometric assay is based on lanthanide fluorescence. This time-resolved fluorescence has a narrow-band emission line whose wavelength differs from that of emission-pulsed light and has a long decay-time. These characteristics make it possible to avoid background interference from sample constituents (protein, light-scattering particles, etc). Europium and its chelates are the most commonly used lanthanides. The europium-labelling of antigens or antibodies is followed by immunoassay. In the final step, fluorescence is measured, after enhancement, as counts per second. This assay has several advantages, including a wide working range, high sensitivity and good practicability. The method has widespread applications in the field of immunoassays in both clinical and research laboratories. The use of non-radioactive europium-labelled probes and the development of simultaneous multiple tests are possible future orientations.

Europium↗
PubMed1992

Evaluation of intestinal clearance and faecal excretion of alpha 1-antiproteinase and immunoglobulins during Crohn's disease and ulcerative colitis.

The intestinal clearance of alpha 1-antiproteinase, monomeric IgA and IgG, and the daily fecal output of polymeric IgA and IgM were investigated in patients with inflammatory bowel diseases (inactive and active Crohn's disease, ulcerative colitis) and in a control group. The intestinal clearance of alpha 1-antiproteinase was significantly increased in all patients with inflammatory bowel diseases (p less than 0.01), irrespective of the grade of the disease. In contrast, increases in intestinal clearances of monomeric IgA and IgG were more closely related to the severity of the intestinal lesions. The associate determination of these three quantities should therefore be of interest for monitoring the degree of intestinal bowel inflammation. Faecal output of polymeric IgA was significantly increased in active intestinal disease (p less than 0.01), whereas faecal IgM levels were not. The determination of the faecal output of polymeric IgA should contribute to the assessment of the activity of inflammatory bowel diseases, and may provide insight into the activation of the mucosal immune system.

Adolescent↗
PubMed1992

Filtration and local synthesis of lacrimal proteins in acquired immunodeficiency syndrome.

In AIDS the onset of the ocular dry syndrome, characterized by lacrimal hyposecretion and deterioration of the corneal and conjunctival epithelium, generally accompanies the clinical aggravation of immunodepression. The study of serum and lacrimal proteins contributes to our knowledge of the pathophysiology of this syndrome. The lacrimal clearance of albumin indicates changes in the permeability of the haemato-lacrimal and conjunctival barrier. Lacrimal monomeric IgA and IgG are mainly of plasmatic origin, while polymeric IgA and IgM are synthesized in situ. The concentrations of these analytes thus reflect ocular humoral immune status. They show a strong humoral protein response in patients with cytomegalovirus retinitis. Lacrimal concentrations of lactoferrin and lysozyme were found to be significantly decreased in AIDS patients with ocular dryness, reflecting a decrease in the secretory activity of the lacrimal gland. Moreover, ocular lympho-plasmocyte infiltration was observed in several patients, with an increase in lacrimal beta 2-microglobulin concentrations. These various lacrimal proteins could be good markers of the ocular dry syndrome in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Detection of occult blood in stools: comparison of three gaiac tests and a latex agglutination test.

The detection of occult blood in the stools is the only simple screening method for colorectal cancer. The aim of this study was to compare the results obtained with the new Hemolex kit (Orion diagnostica, Fumouze France) with those given by three gaiac tests--Hemoccult (Smithkline diagnostics), Hemofec (Boehringer Mannheim) and Hemopreuve (Fumouze) of 165 stools from patients without special diet. Seventy-one patients with at least two positive gaiac tests or a positive Hemolex test underwent colonoscopy followed, if negative, by fibroscopy: 28 had lesions of the lower digestive tract and five of the upper digestive tract. Sensitivity, specificity and negative and positive predictive value were of 70, 98, 91 and 92% respectively for Hemolex; 82, 74, 94 and 44% for Hemoccult; 94, 67, 98 and 42% for Hemopreuve and 91, 73, 97 and 46% for Hemofec. The results obtained in this study confirm the value of the Hemolex test for the detection of human occult blood in the stools whereas the gaiac tests used are influenced by dietary components (unless restricted), explaining their poor positive predictive value. In conclusion, due to their good negative predictive values, the authors recommend that screening for colorectal tumours should be based on the use of two or three gaiac tests which should be confirmed, when positive, by an immunological test for human hemoglobin.

Colonoscopy↗
PubMed1991

Role of cytoskeleton and surface lectins in Giardia duodenalis attachment to Caco2 cells.

An in vitro model of Giardia duodenalis and the Caco2 cell line enable the study of parameters that could play a part in trophozoite attachment. We explored the role of membranous lectins of G. duodenalis in attachment-inhibition studies using carbohydrates in solution. Attachment rates were reduced by 14% and 23% in the presence of 100 mmol/l mannose-6-phosphate and glucose, respectively, as compared with control values. No significant modification was observed after trophozoite trypsinization at room temperature or at 37 degrees C. The inhibitory effects of colchicine (35%) and nocodazole (70%) suggest a primordial role of the cytoskeleton; microtubules appear to be the principal effectors of trophozoite fixation. Scanning electron microscopy revealed circular imprints on the Caco2 brush border after trophozoite detachment. The mechanisms of attachment of G. duodenalis to intestinal enterocyte-like cells in culture are thus essentially of the mechanical or hydrodynamic type; surface lectins would appear to intervene in the specificity for duodenal cells.

Animals↗
PubMed1990

Characterisation of the main molecular forms of human fecal immunoglobulin A.

The molecular composition of fecal IgA is poorly documented, although it is of theoretical and practical importance to determine the different forms of IgA in faeces. Two main molecular forms were isolated by successive steps of ion-exchange chromatography and gel-filtration. The first consisted of secretory IgA dimers dissociating into slightly lower molecular mass forms under the influence of the electric field during electrophoresis. The other contained cleaved-IgA complexed with alpha 1-antitrypsin, that is considered to be a serum origin marker. These results confirm that secretory IgA are relatively resistant to digestive enzymes in vivo, and suggest that alpha 1-antitrypsin-bound fragments originate from serum IgA monomers. Analysis of the proportions of these forms may be of value in the investigation of gut diseases.

Chromatography, Gel↗
PubMedDate not supplied

Evaluation of the permeability of pancreaticogastric anastomoses (PGA) with dynamic magnetic resonance pancreatography after secretin stimulation (secretin MRCP).

BACKGROUND: Because some investigators have reported the systematic occurrence of exocrine pancreatic insufficiency after pancreaticoduodenectomy with pancreaticogastric anastomosis (PGA), we assessed PGA patency after pancreaticoduodenectomy. METHODS: Nineteen patients underwent pancreaticoduodenectomy, and their PGAs were studied prospectively with secretin magnetic resonance cholangiopancreatography (MRCP). After administration of negative bowel contrast agent, single-shot fast spin-echo T2-weighted dynamic MR pancreatograms were obtained before and every minute for 12 min after secretin injection. Morphologic features of the pancreatic parenchymal and pancreatic duct were monitored (diameter and winding aspect of the pancreatic duct, pancreatic thickness, direct visualization of the anastomotic site). PGA permeability was classified into four grades, from 0 (obstruction) to 3 (good permeability). Pancreatic function was assessed by fecal-1 elastase concentration, fasting blood glucose, and fasting serum insulin level. RESULTS: MRCP grades were 0 in two patients, 1 in four, 2 in five, and 3 in eight. The anastomotic site was visualized in 10 patients. Pancreatic parenchymal atrophy was discovered in four patients. There were statistically significant relations between secretin MRCP permeability grade and fecal-1 elastase concentration (p < 0.03) and between secretin MRCP permeability grade and pancreatic atrophy (p < 0.005). In contrast, fecal-1 elastase concentration was lower than the normal value in all but one case. There was no statistically significant relation between fecal-1 elastase concentration and other morphologic data. CONCLUSION: Secretin MRCP may indicate PGA stenosis or dysfunction, but it is not the only factor suggesting exocrine pancreatic insufficiency. Thus the major role of PGA may be the preservation of long-term endocrine function.

Anastomosis, Surgical↗
PubMedDate not supplied

Determination of anti-Cryptosporidium coproantibodies by time-resolved immunofluorometric assay.

The role of the mucosal immune response against Cryptosporidium has been suggested by studies on the therapeutic effects of hyperimmune colostrum. In order to study the intestinal response to this infection, we have developed a sandwich-type time-resolved immunofluorometric assay for the determination of anti-Cryptosporidium coproantibodies. This assay has the inherent sensitivity of an immunoassay without the problems due to background responses from other biological compounds, and is thus suitable for faecal samples. The intra-assay coefficients of variation (5.1%, 4.6%, and 5.8% for immunoglobulins (Ig) A, M and G respectively), inter-assay coefficients of variation (9.4%; 10.5% and 12.2% for IgA, IgM and IgG, respectively) and specificity (100% for all 3 isotypes) were all satisfactory. Using this assay to study 12 patients with the acquired immune deficiency syndrome (AIDS) who were infected with cryptosporidiosis, we found a marked elevation of anti-Cryptosporidium IgA and IgM coproantibody titres relative to 18 healthy control values, but no correlation with the gravity of the infection in terms of oocyst shedding. These results suggest that a non-protective mucosal immune response develops to Cryptosporidium in AIDS patients.

AIDS-Related Opportunistic Infections↗