Search PubMed⌕ Search

Biomedical subjects

S Bretagne

Publications and source records attributed to S Bretagne.

At least 55 records · Page 3Linked to original sources
PubMed1996

Improvement of a polymerase chain reaction assay for the detection of Echinococcus multilocularis DNA in faecal samples of foxes.

A polymerase chain reaction (PCR) method was developed in order to permit a sensitive and specific identification of Echinococcus multilocularis DNA from fox faecal specimens. In an attempt to overcome problems related to the presence of endogenous PCR inhibitors in faecal extracts, we investigated a DNA extraction technique using an anion binding resin (Gene-Fizz). This simple and rapid procedure was applied to 61 faecal samples. Compared with the traditional microscopic examination, the sensitivity of PCR using Gene-Fizz was 82.3% and the specificity was 95.5%. No PCR signal was obtained for 20 Echinococcus granulosus isolates, showing that this method allowed discrimination between E. multilocularis and E. granulosus. Large-scale epidemiological surveys of fox excrements may be possible by using Gene-Fizz treatment prior to PCR amplification reactions.

Animals↗
PubMed1996

Identification of intracellular stages of Cyclospora species by light microscopy of thick sections using hematoxylin.

Cyclospora sp is a recently identified coccidia responsible for enteric infection in humans. Most reports have failed to detect this parasite in intestinal biopsies by light microscopy, although the different stages have been ultrastructurally described in jejunum enterocytes. Very recently, some investigators have reported the detection by light microscopy of parasitophorous vacuoles in intestinal biopsies; however, only transmission electron microscopy (TEM) could clearly identify the parasitic stages. To improve the histological diagnosis without using TEM, we have tested different staining methods in biopsies obtained from a patient infected by the human immunodeficiency virus who was shedding Cyclospora oocysts. Hematoxylin stain alone for 15 minutes on 5 micrometer-thick sections of duodenal biopsies was found to be the most efficient method for observing different stages of the parasite. In particular, the banana-shaped merozoites were visualized and appeared very similar to the human coccidia Isopora belli. This simple technique may be useful in diagnosing Cyclospora infection.

AIDS-Related Opportunistic Infections↗
PubMed1996

PCR enzyme-linked immunosorbent assay for diagnosis of leishmaniasis in human immunodeficiency virus-infected patients.

A PCR enzyme-linked immunosorbent assay (ELISA) involving the use of bone marrow aspirates (BMA) and blood samples (BS) for the diagnosis of visceral leishmaniasis (VL) in human immunodeficiency virus-infected patients was developed with primers selected from the sequence of the small-subunit rRNA gene and compared with direct examination and in vitro cultivation. The PCR was optimized for routine diagnosis: processing of samples with lysis of erythrocytes without isolation of leukocytes, enzymatic prevention of contamination, internal control of the reaction, and ELISA testing in a microtitration plate hybridization. Of 79 samples (33 BMA and 46 BS) from 77 patients without VL, all the results were negative. Fifty-three samples (9 BMA and 44 BS) were obtained from 13 patients with VL: 6 samples drawn during anti-Leishmania treatment were negative whatever the technique used, and 47 samples (9 BMA and 38 BS) were positive with at least one technique. The sensitivities were 51% (24 of 47), 81% (38 of 47), and 98% (46 of 47) for direct examination, culture, and PCR, respectively. Thus, PCR ELISA is reliable for diagnosing VL in human immunodeficiency virus-infected patients, and blood sampling should be sufficient for the follow-up.

AIDS-Related Opportunistic Infections↗
PubMed1995

Detection of Aspergillus species DNA in bronchoalveolar lavage samples by competitive PCR.

A competitive PCR assay involving the use of bronchoalveolar lavage (BAL) samples for the diagnosis of invasive pulmonary aspergillosis (IPA) was developed. For this purpose, a 1-kb mitochondrial DNA fragment of Aspergillus fumigatus was sequenced. The primers used allowed amplification of A. fumigatus, A. flavus, A. terreus, and A. niger DNAs but not DNAs of other fungi and yeasts. BAL samples from 55 consecutively enrolled patients were tested. Three samples were excluded because of failure of correct amplification of the internal competitive control. Of 28 immunocompromised patients, 6 were PCR positive; 3 died of IPA and their BAL cultures yielded A. fumigatus; and 3 were culture negative and did not develop IPA. Of 15 human immunodeficiency virus-positive patients and 9 immunocompetent patients, 5 and 4, respectively, were both PCR positive and culture negative, and none developed aspergillosis. Thus, PCR confirmed IPA in three patients but gave positive results for 25% (12 of 49) of the patients who did not develop aspergillosis. The predictive value of PCR-positive results seems low for patients at risk for aspergillosis. Moreover, the risk of contamination of reaction buffers or biological samples with Aspergillus conidia seems high and has to be weighed in regard to the potential diagnostic benefit of PCR testing as a routine procedure.

AIDS-Related Opportunistic Infections↗
PubMed1995

Quantitative competitive PCR with bronchoalveolar lavage fluid for diagnosis of toxoplasmosis in AIDS patients.

Of 121 AIDS patients, 12 (10%) had Toxoplasma gondii DNA detected by competitive PCR in their bronchoalveolar lavage samples. Quantitation of the PCR results showed a correlation between the parasite burden and the serum lactic dehydrogenase titer. Quantitative competitive PCR could be useful to assess the diagnosis and the severity of pulmonary toxoplasmosis.

AIDS-Related Opportunistic Infections↗
PubMed1995

Late toxoplasmosis evidenced by PCR in a marrow transplant recipient.

We report a case of disseminated toxoplasmosis occurring 12 months after allogeneic BMT. The patient was seropositive for Toxoplasma gondii, and the donor was seronegative, so the patient was given anti-Toxoplasma prophylaxis. One year after BMT, he developed fever and muscle pain without other clinical symptoms. PCR amplification for T. gondii performed on blood was positive. Toxoplasma were found in bronchoalveolar lavage by PCR and in the marrow by special stains. With treatment, the PCR signal disappeared in 3 days while clinical symptoms resolved over 15 days. This case emphasizes the possibility of late toxoplasmosis after BMT despite prophylatic treatment, and the value of PCR in making the diagnosis.

Adult↗
PubMed1994

Lichen planus and hepatitis C virus--related chronic active hepatitis.

BACKGROUND AND DESIGN: An increased prevalence of chronic liver disease has been reported in patients with lichen planus (LP). We report six cases of LP associated with chronic active hepatitis and actively replicating hepatitis C virus (HCV). RESULTS: We studied six patients (three men and three women; mean age, 61 years; age range, 47 to 70 years) with various forms (cutaneous and/or mucosal) of LP and abnormal liver test results. Four patients had severe mucosal lesions. Cutaneous and mucosal lesions had a long-term evolution. Liver disease was discovered 2 to 6 years before LP in three cases and was diagnosed at the same time as LP in the three other cases. Liver biopsy performed in five patients showed chronic active hepatitis without cirrhosis in all five cases. Anti-HCV antibodies were detected in all cases by second-generation enzyme-linked immunosorbent assay and confirmed by second-generation recombinant immunoblot assay. Hepatitis C virus RNA was evidenced by means of polymerase chain reaction in the serum samples from the six patients, proving active viral replication. CONCLUSIONS: Lichen planus may be associated with HCV-related chronic active hepatitis. As interferon treatment may induce viral inactivation in some patients with HCV-related chronic liver disease, a search for HCV infection should be systematically performed in patients with chronic LP.

Aged↗
PubMed1993

Detection of Echinococcus multilocularis DNA in fox faeces using DNA amplification.

In order to identify Echinococcus multilocularis DNA in fox faeces for epidemiological purposes, we have developed a new method to prepare DNA suitable for PCR amplification. DNA isolation from fox excrement was performed according to a novel procedure involving lysis in KOH, phenol-chloroform extraction and a purification step on a matrix (Prep-A-Gene). The target sequence for amplification was the E. multilocularis U1 snRNA gene. PCR products were indistinguishable for 32 different E. multilocularis isolates and no signal was observed after ethidium bromide staining with DNAs from other tapeworm species, including E. granulosus. The sensitivity of amplification was monitored by the addition of E. multilocularis DNA or eggs to faeces free of E. multilocularis and was estimated to be 1 egg per 4 g of faeces. PCR products were blotted onto nylon membranes and hybridized with an internal oligonucleotide probe in order to confirm the results. Twenty nine faecal samples from foxes shot in Franche-Comté (East France) were tested. Out of 10 samples from foxes in which no E. multilocularis adult worms could be observed after necropsy, 7 were PCR positive, showing that the PCR test is more sensitive than microscopical examination. Out of 19 samples from foxes harbouring E. multilocularis adult worms, 18 were PCR positive. The remaining PCR-negative sample could be due either to the misidentification of the species of adult worm (E. granulosus and E. multilocularis), or to DNA variation between different isolates of E. multilocularis. Further work in the field should be initiated in order to confirm these results.

Animals↗
PubMed1993

Detection of Toxoplasma gondii by competitive DNA amplification of bronchoalveolar lavage samples.

The prevalence of pulmonary toxoplasmosis was assessed by a prospective analysis of 144 bronchoalveolar lavage (BAL) samples using competitive polymerase chain reaction (PCR) to avoid false-negative results due to PCR techniques. Six samples were excluded because they contained amplification reaction inhibitors. None of the samples from the 37 immunocompetent patients and only 1 sample (1.7%) from the 59 immunocompromised patients without human immunodeficiency virus infection were PCR-positive. In contrast, Toxoplasma gondii DNA was found in 6 (14%) of 42 samples from patients with AIDS. All 6 patients had < or = 40 CD4 cells/microL and anti-Toxoplasma antibodies, and 5 had other sites of Toxoplasma infection. Six other AIDS patients who had received treatment for cerebral toxoplasmosis were PCR-negative. Thus, pulmonary toxoplasmosis is frequent in AIDS patients who have other sites of Toxoplasma infection and low CD4 lymphocyte counts and who are not receiving prophylaxis.

Adolescent↗
PubMed1993

Hepatitis C virus infection can mimic type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis.

Hepatitis C virus (HCV) has been shown to induce anti-liver-kidney microsomal-1 (LKM1) antibody positive chronic active hepatitis, simulating type 2 autoimmune chronic active hepatitis. The cases of five patients presenting with features of type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis and extrahepatic autoimmune manifestations, in whom immunosuppressive treatment had no effect on liver disease are presented. In these patients, HCV infection could be shown by the presence in serum of anti-HCV antibodies and HCV-RNA detected by polymerase chain reaction. These cases suggest the following: (a) chronic HCV infection can mimic type 1, as well as type 2, autoimmune chronic active hepatitis; (b) HCV infection might be systematically sought in patients presenting with features of type 1 autoimmune chronic active hepatitis, with special care in patients who are unresponsive to immunosuppressive treatment.

Aged↗
PubMed1993

[Prevalence of Enterocytozoon bieneusi spores in the stool of AIDS patients and African children not infected by HIV].

Enterocytozoon bieneusi is a newly described microsporidia in humans thought to be responsible for chronic diarrhoea in acquired immunodeficiency syndrome (AIDS) patients. The epidemiology of this parasite is still unknown; it could be a strictly opportunistic agent or a human enteropathogen. E. bieneusi spores were searched for in stool smears of two populations using a modified chromotrope 2R staining. The first population consisted of 60 patients infected by the human immunodeficiency virus (HIV) and the second of 990 children aged from one month to six years consulting two primary care centers in Niamey, Niger. E. bieneusi spores were found in 4 out of the 60 HIV-positive patients (7%). These 4 patients belonged to a subgroup of 35 patients with < 50 CD4 cells/microliters. Out of 990 children, 8 shed E. bieneusi spores in their stools; the presence of spores was not associated with a particular clinical phenotype (diarrhoea, fever, dehydration, vomiting). Although HIV status could not be evaluated, the HIV prevalence rate among women consulting the same care centers was low (0.5%) and it is therefore unlikely that all eight children were HIV-infected. The results show for the first time that E. bieneusi can infest HIV-negative subjects. Microsporidiosis is frequent in AIDS patients with low CD4 cell counts. Further work is needed to define the prevalence and the possible pathogenic effect of E. bieneusi in immunocompetent subjects.

AIDS-Related Opportunistic Infections↗
PubMed1992

[Detection of the eggs of Echinococcus multilocularis Leuckart, 1863, in the feces of the fox (Vulpes vulpes Linnaeus, 1758) by the polymerase chain reaction].

The polymerase chain reaction (PCR) was applied to the identification of eggs of Echinococcus multilocularis in faeces from foxes. The test was positive in three of six faeces samples from foxes which were harbouring adult worms, and in one of four samples from foxes in which no adult E. multilocularis was found in the intestines. These initial results show that it is possible to use PCR to identify E. multilocularis eggs in faeces. PCR can be used to complement examination of intestinal contents, showing that the distribution of eggs in faeces is uneven. The sensitivity of the test was estimated to be 50 eggs in 5 g of faeces. Further work is needed to confirm these initial results before the test can be used more widely.

Animals↗
PubMed1991

Structure of the Echinococcus multilocularis U1 snRNA gene repeat.

The gene encoding U1 snRNA in Echinococcus multilocularis has been cloned and sequenced. This gene is contained within a 1300-bp sequence which is tandemly repeated in the E. multilocularis genome. E. multilocularis U1 snRNA is 50-70% homologous to U1 snRNAs of other species. E. multilocularis U1 snRNA could assume a predicted secondary structure similar to that proposed for other U1 snRNAs, and appears shorter (157 bases) than the U1 snRNAs of higher eukaryotes (163-166 bases).

Amino Acid Sequence↗
PubMed1990

Rapid technique for cryopreservation of Echinococcus multilocularis metacestodes.

Cysts of E. multilocularis were minced to prepare a crude homogenate and after addition of glycerol at a final concentration of 10%, cryopreservation was performed at a rate of 1 degree C min-1 in a controlled-rate freezer. The aliquots were subsequently stored in liquid nitrogen. All 22 isolates tested were successfully cryopreserved and their viability maintained.

Animals↗