Biomedical subjects

M Subirats

Publications and source records attributed to M Subirats.

At least 19 recordsLinked to original sources

PubMed2003

Abnormal depolarizing patterns in three patients with filarial infection.

Several authors have described a particular potential of automated depolarization analysis in detecting malaria infection as part of the routine full blood count (FBC) performed by the Cell-Dyn 4000 analyzer. In these cases, abnormal depolarizing patterns are due to the presence of leukocyte-associated malaria hemozoin, a pigment which depolarizes the laser light. In this report we describe samples from three individual patients who did not have malaria infection but showed abnormal depolarizing events. Further investigation determined that these samples were from patients infected by the nematode Mansonella perstans. The observed depolarizing pattern consisted of a normal depolarizing eosinophil population and in addition an abnormal depolarizing population that showed a close "linear" relationship between "granularity" (90 degrees depolarization) and "lobularity" (90 degrees polarization). This atypical population was smaller than normal leukocytes and thus clearly different from the patterns associated with malaria infection. Abnormal depolarization patterns of M. perstans clearly do not reflect leukocyte-associated malaria hemozoin. It is possible however that the erythrocyte-lysing agent used to facilitate leukocyte analysis by the instrument may have caused microfilaria fragmentation and thus the distinctive "straight-line" features of the abnormal scatter plots

Blood Cell Count↗

PubMed2001

Limited level of accuracy provided by available rapid diagnosis tests for malaria enhances the need for PCR-based reference laboratories.

The rise of imported malaria cases and the high fatality rate in Europe make the search for new and easy diagnostic methods necessary. Rapid diagnosis tests (RDTs) are, in part, developed to cover the lack of diagnosis experience. Unfortunately, our data suggest that the accuracy of RDTs is insufficient and could increase the number of incorrect malaria diagnoses.

Adolescent↗

PubMed2000

The use of PCR in the diagnosis of hyper-reactive malarial splenomegaly (HMS).

Between August 1997 and September 1998, 14 cases of hyper-reactive malarial splenomegaly (HMS) were diagnosed in the Instituto de Salud Carlos III in Madrid, Spain. These cases, from Equatorial Guinea and Cameroon, were identified using the diagnostic criteria established by Y. M. Fakunle in 1981: gross splenomegaly; high levels of anti-malarial antibodies; IgM in serum at least two standard deviations above the local mean; and clinical and immunological response to antimalarial treatment. Although malarial parasites were only detected in the Giemsa-stained blood films of four of the cases, these four and four others were found to have the DNA of such parasites in their blood when tested using a method based on a semi-nested, multiplex PCR. These result indicate that malarial parasitaemias may be more prevalent in HMS than is usually recognized.

Adult↗

PubMed2000

[Evaluation of different clinical samples and cell lines in the isolation of enterovirus in pediatric patients].

BACKGROUND: To evaluate prospectively the efficacy of different clinical samples and cellular lines in the isolation of Enteroviruses from pediatric patients. METHODS: In the period july-1997 to july-1999 we analyze the samples of 102 pediatric patients (< 2 years old) with an unknown febrile etiology syndrome. After the process of decontamination the samples were inoculated in the MRC-5, Hep-2 and Vero cell lines by the shell-vial assay. After 2-3 days of incubation the monolayers were stained by a monoclonal antibody against VP1; then the strains were identified as Poliovirus, ECHO-virus or Coxsacke by specific antibodies. RESULTS: 96 clinical samples were studied (45 pharyngeal swabs, 28 feces, 13 cerebrospinal fluid, 5 bloods, 4 urines and one bronchoalveolar lavage). Enteroviruses were isolated in 48 patients (47%), corresponding to 60 clinical samples (62.5%). The enteroviruses were isolated in 75.5% of pharyngeal swabs, 71.4% of feces, 30.7% of cerebrospinal fluid, one blood (20%) and the bronchoalveolar lavage. 28 patients presented simultaneously both pharyngeal and rectal swabs; in this group the use of both samples permitted the isolation of Enteroviruses in 26 cases (92.8%). Of 60 Enteroviruses, 59 (98.3%) were isolated in the MRC-5 cell line, 23 (38.3%) in the Hep-2, and 14 (23.3%) in the Vero; the MRC-5 demonstrated a significant difference in the isolation of Enteroviruses compared with the other cell lines. The Enteroviruses were identified as 30 (50%) ECHO-virus, 15 (25%) as Poliovirus vaccine, 12 (20%) could not to be identified and in 3 cases (5%) no growth of virus was detected in the culture. The MRC-5 cell line was significatively superior to the other in the isolation of the different Enteroviruses. CONCLUSIONS: To obtain the maximum diagnostic efficacy in front a patient with a possible infection by Enteroviruses, is necessary to use different clinical samples, specially the more related to the infection focci (cerebrospinal fluid or blood). The MRC-5 cell line has been the most efficace in the isolation of Enteroviruses independently of the type of clinical sample or the viral genus. The shell-vial assay is a good method for the isolation and identification of Enteroviruses isolated from clinical samples.

Animals↗

PubMed1999

Usefulness of seminested multiplex PCR in surveillance of imported malaria in Spain.

The use of a new PCR-based method for the diagnosis of malaria in the Spanish Malaria Reference Laboratory has promoted an increase in confirmed cases of malaria. From August 1997 to July 1998, a total of 192 whole-blood samples and 71 serum samples from 168 patients were received from the hospitals of the Spanish National Health System. Most of the patients came from west-central African countries (85%). This molecular method showed more sensitivity and specificity than microscopy, detecting 12.4% more positive samples than microscopy and 13% of mixed infections undetectable by Giemsa stain. Plasmodium falciparum was the main species detected, with 68% of the total positive malaria cases, followed by Plasmodium malariae (29%), Plasmodium vivax (14%), and Plasmodium ovale (7%), including mixed infections in all cases. This report consists of the first wide, centralized survey of malaria surveillance in Spain. The reference laboratory conducted the analysis of all imported cases in order to detect trends in acquisition. The use of a seminested multiplex PCR permitted confirmation of the origins of the infections and the Plasmodium species involved and confirmation of the effectiveness of drug treatments. This PCR also allowed the detection of the presence in Spain of primaquine-tolerant P. vivax strains from west-central Africa, as well as the detection of a P. falciparum infection induced by transfusion.

Child, Preschool↗

PubMed1999

Induction of histamine release in parasitized individuals by somatic and cuticular antigens from Onchocerca volvulus.

The host immune response in onchocerciasis is believed to contribute to the clinical manifestations of infection. Mazzotti and chronic inflammatory reactions might be mediated by mechanisms involving specific IgE and reactivity of mast cells and basophils to the parasite antigens. In this report, we show that Onchocerca volvulus antigens are capable of inducing histamine release. Three types of extracts were prepared from the parasite: soluble total, surface, and cuticular collagen. Soluble extracts released histamine in all individuals with onchocerciasis at significantly higher levels (P < 0.05) than those found in endemic controls, but similar levels to those found in patients with mansonellosis. However, cuticular collagen induced significantly (P < 0.01) higher histamine release in patients with onchocerciasis than in those with mansonellosis. No reactivity against human type IV collagen was observed. Implications derived from the presence of sensitized basophils in the pathogenesis of onchocerciasis are discussed.

Adolescent↗

PubMed1997

[Eosinophilic gastroenteritis caused by bee pollen sensitization].

A 34-year-old Spanish woman with a lifelong history of seasonal rhinoconjunctivitis and honey intolerance (pyrosis and abdominal pain) developed, 3 weeks after starting ingestion of bee pollen, astenia, anorexia, abdominal pain, diarrhoea, peripheral blood hypereosinophilia and elevated serum total IgE levels. A duodenal biopsy showed eosinophilic infiltration of the mucosal layer. Other causes of hypereosinophilia were not found. Repeated parasitological stool studies, as well as a duodenal aspirate showed negative results. Symptoms, hypereosinophilia and elevated IgE levels resolved after bee pollen ingestion was stopped. This is a typical case of eosinophilic gastroenteritis by ingestion of bee pollen in a woman with intolerance to honey bee, because the patient fulfilled the usual diagnostic criteria: gastrointestinal symptoms were present, eosinophilic infiltration of the digestive tract was demonstrated by biopsy, no eosinophilic infiltration of other organs was found and the presence of parasites was excluded. Honey intolerance and/or bee pollen administration should be considered as a cause of eosinophilic gastroenteritis.

Adult↗

PubMed1997

[Species identification of intestinal microsporidiosis in HIV-positive patients using the polymerase chain reaction].

BACKGROUND: Microsporidia are opportunistic parasites which, due to their morphologic characteristics, continue presenting diagnostic problems. Species-specific identification of microsporidia has become important because of varying levels of response to albendazole, which is the only effective treatment for some kinds of intestinal microsporidiosis. Although these parasites cause up to 50% of otherwise unexplained chronic diarrhea in HIV-positive patients, the number of reported cases is still very scarce in our country when compared to the existing HIV-positive population. METHODS: Intestinal microsporidiosis in HIV-positive patients with diarrhea was investigated using the modified trichrome staining technique. Microsporidia species identification was done by indirect immunofluorescence (IIF) and polymerase chain reaction (PCR) with specific primers. RESULTS: Six new cases of intestinal microsporidiosis caused by Enterocytozoon bieneusi were diagnosed in Madrid (Spain). All patients were in an advanced state of the HIV infection and they presented CD4+ values equal or inferior to 100 x 10(6)/I. CONCLUSIONS: Due to the number of cases that are accumulating, microsporidia must be included among the enteropathogens responsible for chronic diarrhea in HIV-positive individuals in Spain. The PCR technique using specific primers is a suitable determinator of the microsporidia species implicated in this intestinal pathology.

AIDS-Related Opportunistic Infections↗

PubMed1996

[Diagnosis of 4 cases of intestinal microsporidiosis in AIDS patients].

BACKGROUND: Most of the latest clinical and epidemiologic studies indicate that microsporidiosis and above all Enterocytozoon bieneusi cause approximately 7-50% of otherwise unexplained diarrhea in HIV-infected patients. Four cases of intestinal microsporidiosis in AIDS-patients are reported. METHODS: Detection of spores of microsporidiosis in stool samples from HIV-infected patients was performed by the following techniques: 1) light microscopy, using Kokoskin's modification of the Weber trichrome stain; 2) electron microscopy, for confirmation (only available in one case), and 3) indirect immunofluorescence assay (IIF), performed on all positive samples. Rabbit polyclonal antibodies anti-Encephalitozoon cuniculi, anti-E. hellem and anti-E. (Septata) intestinalis were used to eliminate the possibilities of presence of microsporidiosis other than E. bieneusi. RESULTS: Detection of spores of microsporidiosis by trichrome stain was positive in all samples from the 4 patients. By elimination, IIF confirmed the presence of Enterocytozoon bieneusi in all 4 cases. E. bieneusi was identified by electron microscopy in the only case available. Three patients had CD4+ lymphocyte counts < 100 x 10(6)/l and one < 500 x 10(6)/l. All had AIDS and three of them were homosexual. Two patients remained positive for microsporidiosis for almost 5 months. CONCLUSIONS: Despite the very few cases described in Spain, these preliminary data lead us to believe that intestinal microsporidiosis should be considered as an possible cause of diarrhea in our country also, and mainly in acute immunodeficiency patients.

Acquired Immunodeficiency Syndrome↗

PubMed1995