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G Piédrola

Publications and source records attributed to G Piédrola.

70 records · Page 4Linked to original sources
PubMed1993

Evaluation of the capacity of oral streptococci to produce hydrogen peroxide.

The capacity of 11 strains of oral streptococcal species (Streptococcus sanguis, S. oralis, S. mitis and S. sobrinus) to produce hydrogen peroxide (H2O2) was studied in vitro. Detection of this property in solid media, particularly with trypticase soy agar-benzidine-peroxidase, was more sensitive than in liquid media. The addition of carbohydrates (arabinose, xylose, mannose, sorbose and lactose), sorbitol and saccharine to buffered trypticase soy broth increased H2O2 production in S. oralis NCTC 11427, although the concentrations obtained with some substrates (glucose, galactose, mannitol and xylitol) were lower than those obtained in controls. In S. sanguis NCTC 7863, H2O2 production was detected only with galactose, sorbitol, lactose and saccharin.

Carbohydrate Metabolism↗
PubMed1993

Circulating Candida antigens and antibodies: useful markers of candidemia.

To investigate the utility of the 48-kDa antigen from Candida albicans in its commercial form (Directigen; Becton Dickinson) and three other serodiagnostic methods (detection of one antigen by Pastorex Candida [Sanofi Diagnostics Pasteur] and detection of immunoglobulin G [IgG] and IgM antibodies to C. albicans blastoconidia [bioMerieux]) for diagnosis of invasive Candida infection, we conducted a prospective clinical trial among 10 patients with candidemia (group 1), 30 patients colonized by C. albicans (group 2), 20 patients with bacteremia (group 3), and 20 subjects without clinical or microbiological evidence of infection. The Directigen system was positive for at least one serum sample each from eight patients in group 1. In groups 2, 3, and 4, it was positive for only three patients. There was no reaction to the Pastorex system in any of the patients infected with or colonized by C. albicans or in the non-Candida-carrying controls. The IgG antibody concentration oscillated between 100 and 800 (mean, 510 +/- 268) IU/ml for the patients in group 1. In this group, eight patients had IgG antibody levels of > 400 IU/ml. The percentages of persons with IgG antibody levels of > 400 IU/ml in groups 2, 3, and 4 were 43.3, 0, and 0, respectively. Specific IgM antibody was present in all group 1 patients but not in those in groups 2, 3, and 4. The sensitivity and specificity of the Directigen test were 65 and 97.1%, respectively. For the Pastorex test, the sensitivity was 0%. The sensitivity of IgG antibodies was 80%, with a specificity of 81.4%, while the IgM antibodies were 100% specific and sensitive. Both the positive and negative predictive values of specific IgM antibodies appeared to be superior to those of the other three tests.

Antibodies, Fungal↗
PubMed1992

Gigant carcinosarcoma.

We present a case with gigantic carcinosarcoma (the largest described to date, diameter of 20.5 cm), located in the right upper lobe, in which the discordance between the brief clinical course with limited symptoms and its large size were remarkable. Preoperative diagnosis by bronchial biopsy, as used to be the case in this malignancy, was incorrect (epidermoid), and the define histological characterization was made by thoracotomy. The controversy about pathology, diagnosis and treatment of the carcinosarcoma is discussed.

Biopsy↗
PubMed1992

[Acute infections caused by Epstein-Barr virus. Comparative study of various diagnostic methods].

Comparative performance of four methods (IFI, IgM anti-VCA, Organon Teknika; ELISA, IgM anti VCA, Incstar Corp and Pharmacia Diagnostic Inc; ELISA IgM against a group of several antigens which principal component is EBNA, Behring Institute) to detect antibodies (Abs) against Epstein-Barr virus in 180 patients (group 1) with infectious mononucleosis with no heterophil Abs (Organon Teknika), 180 healthy subjects with no heterophil Abs (group 2) and 20 patients with infectious mononucleosis (group 3) and with positive heterophil Abs, were studied. In group 1, 10% of patients had IgM Abs, without differences IgM Abs. In group 3 all patients had IgM Abs with no differences in the methods studied. There were no differences in the performance of the evaluated methods to detect IgM against different antigens, but those which use a group of antigens from the virus could be more useful in patients immunologic disorders.

Adolescent↗
PubMed1991

A comparative study of the activity of first and second generation cephalosporins and their combinations with beta-lactamase inhibitors against Bacteroides fragilis.

The sensitivity of 160 strains of Bacteroides fragilis, 74 beta-lactamase-positive and 86 negative, to two first generation and four second generation cephalosporins, alone and in combination with clavulanic acid and sulbactam, was investigated. For the susceptibility test the dilution method in agar was used. The detection of beta-lactamase production by this micro-organism was performed by means of the method using chromogenic cephalosporin of Nitrocefin. In both strains an important improvement in the activity of cephalothin, cephazolin, cefonicid and cefamandole was noted when they were combined with the two inhibitors. In combinations of cefoxitin and cefmetazole, no significant improvement was evident in the values of the parameters studied in the beta-lactamase-producing strains; and even in beta-lactamase-negative strains these values showed only a slight increase.

Bacteroides fragilis↗
PubMed1991

Comparison of the activity of imipenem and beta-lactams combined with sulbactam and clavulanic acid in beta-lactamase-producing strains of Bacteroides fragilis.

We compared the "in vitro" activity of imipenem with 14 beta-lactams, both alone and in combination with clavulanic acid, and sulbactam against 110 beta-lactamase-producing strains of Bacteroides fragilis. The following antibiotics were tested: amoxycillin, penicillin, mezlocillin, piperacillin, cephalothin, cephazolin, cefamandole, cefmetazole, cefonicid, cefoxitin, cefotaxime, ceftazidime, ceftizoxime, and ceftriaxone. In all cases, except those of cefoxitin and cefmetazole, these combinations showed a statistically significant increase in beta-lactam activity, which was, however, never higher than that of imipenem, the antibiotic which performed best against Bacteroides fragilis.

Anti-Bacterial Agents↗
PubMed1989

Dysfunction of the mononuclear phagocytic system in sepsis.

An in vivo study has been undertaken of the Fc(IgG) receptor-mediated phagocytic capacity of macrophages (clearance of anti-rhesus D-coated-51 Cr-labelled autologous erythrocytes, expressed as half-lives) in 15 cases of sepsis to establish its behaviour and correlate this function to levels of circulating immune complexes (anti-Clq-nephelometry). Five patients with low activity (2261 +/- 859 minutes) developed septic shock; the other ten showed high activity (5.8 +/- 1.5 minutes) and did not develop septic shock. Differences from the control group (30 +/- 12 minutes) were found (p less than 0.001). Receptor activity was related to the presence of circulating immune complexes (p less than or equal to 0.001; delta = 0.862) but not to age, sex, or the presence/absence of splenomegaly during the illness. Eight patients responded favourably; seven patients died; but the receptor activity was not related to this. During sepsis it is possible to find higher Fc(IgG) receptor-mediated phagocytic capacity of macrophages. Excessive formation of circulating immune complexes has a negative influence on Fc(IgG) receptor-mediated phagocytosis. This activity of macrophages, measured at the start of the sepsis, was not associated with the final outcome of the patients' illness (cure or death).

Antigen-Antibody Complex↗
PubMed1988

Comparison of in vitro activity of cefotaxime and desacetylcefotaxime alone and in combination against 320 gram-negative clinical isolates.

The antimicrobial activity of cefotaxime and its intermediate metabolite, desacetylcefotaxime, against 320 Gram-negative bacterial strains was analysed to investigate whether combination of the 2 substances led to increased bactericidal activity. The in vitro study of the minimum inhibitory concentration (MIC) showed the combination to be more effective against Escherichia coli, Klebsiella spp., Enterobacter spp. and Proteus mirabilis, requiring less than or equal to 50% of the concentration of cefotaxime alone to inhibit 90% of strains. For other micro-organisms the MIC90 for the combination was equal to or within 1 dilution of that for cefotaxime alone.

Bacterial Infections↗
PubMedDate not supplied

Detection of specific IgG and IgM antibodies in the haemagglutination inhibition test and the enzyme-linked immunoassay for the diagnosis of rubella infection.

A study has been carried out on the sera of 710 women who wished to know their state of rubella immunity using haemagglutination inhibition (HAI) and enzyme-linked immunoassay (ELISA) techniques. The majority of the women presented no symptoms. The ability of HAI to detect low antibody levels (1:8, 1:16) appears to be greater than that of Rubazyme ELISA IgG, employing the recommendations of the manufacturers. The correlation between HAI and IgG values above HAI titres of 1:16 is nearly 100%. In an additional study of 17 primary infections in pregnant women with definite rubella symptoms, the total titre of antibodies was determined by HAI and IgG and specific IgM with ELISA Rubazyme in successive samples. In four cases, IgM was clearly positive and no increase in either HAI or IgG antibodies could be demonstrated over three successive samples taken at an interval of 15 to 20 days. Therefore, we consider it necessary to determine IgM antibodies (evaluating these in the absence of the rheumatoid factor) in every doubtful case occurring in pregnant women, irrespective of whether clinical signs are present or not.

Antibodies, Viral↗
PubMedDate not supplied

A seroepidemiological study of human immunodeficiency virus infection in northeast Zaire.

To evaluate the incidence of human immunodeficiency virus type 2 infections in an endemic African area, we have studied 134 patients from Northeast Zaire. Sera were tested for HIV-1 and HIV-2 antibodies to asses cross-reactivity or a possible double infection. Sixty five (48.5%) serum samples were reactive for HIV-1 and six (4.5%) for HIV-2 using specific Western blots. The enzyme immunoassays used to detect HIV-2 showed cross-reactivity with HIV-1 in 17 samples (16.5%). Tests based upon synthetic peptides corresponding to specific from human immunodeficiency viruses confirm their ability to discriminate antibodies directed against both viruses in 42/47 samples (89.4%); in 5/47 (10.6%) this test could not distinguish double infection from cross-reactivity. We suggest that the high number of sexual partners may be responsible for HIV transmission in our study group.

AIDS Serodiagnosis↗
PubMedDate not supplied

Immune complex p24 antigen: a new prognostic marker in human immunodeficiency virus infection.

p24 antigen (p24 Ag) is usually not found in patients in the asymptomatic phase of HIV infection, mainly because it is bound to anti-p24 antibodies (p24 Ab), with which it forms immune complexes. Nine asymptomatic patients positive for HIV-1 antibodies (stage II CDC criteria) treated with r alpha-interferon were followed (7.5 +/- 0.5 months), and a basal and final sample were tested for p24 Ag immune complexes (p24 Ag-IC), free p24 Ag, p24 Ab, CD4 count, beta 2-microglobulin, properdin B factor, and C3 and C4 complement fractions. p24 Ag-IC was detected in 55.5% of the samples, whereas free p24 Ag was detected in 5.5%. The finding of no change or an increase in p24 Ag-IC serum levels may be considered a prognostic marker. We believe that p24 Ab cannot be used as a prognostic marker unless p24 Ag-IC detection is simultaneously evaluated.

Antigen-Antibody Complex↗
PubMedDate not supplied

Granulocyte abnormalities in parenteral drug-addicts. The influence of HIV infection.

In the present paper we studied the phagocytic capacity of polymorphonuclear leukocytes and their capacity to adherence to substrates, in parenteral drug-addicts with or without HIV infection. Our results show a significant decrease in the phagocytic index of drug-addicts, which is independent of the coexistence of an HIV infection. The simultaneous presence of this virus leads to the emergence of alterations in the leukocytic adhesiveness, with a decrease in adhesiveness that is more marked in AIDS patients. The simultaneous association of drug addiction with AIDS leads to the impairment of these two stages in the leukocyte defense.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Complement and sepsis.

The present study is an evaluation of changes undergone in the serum of factors C3 and C4 of the complement, IgG, IgA, IgM and circulating immune complexes during the initial phase of sepsis and throughout its development in 53 patients, with the object of establishing their prognostic value. During the initial phase of sepsis the determination of the serum levels of immunoglobulins (IgG, IgA, IgM), C3 and C4 complement components and circulating immune complexes lack prognostic interest. Nevertheless, the disappearance of circulating immune complexes, together with an intensive reduction in concentration of IgG, IgM, and C3 and C4 complement components below the range of normality, during the evolutive course, is an indication of a bad prognosis.

Adult↗