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Biomedical subjects

M C Maroto

Publications and source records attributed to M C Maroto.

16 recordsLinked to original sources

An enzyme-linked (alkaline phosphatase) oligonucleotide probe for the detection of serum hepatitis B virus DNA.

Serum HBV-DNA detection represents a new and important diagnostic tool for the hepatologist, as well as a prognostic and therapeutic guide. Though most laboratories use genomic radioactive probes, the appearance of commercially available enzyme-linked oligonucleotide probes, which simplify the method, represents an advance in HBV-DNA detection. In order to verify the value of an enzyme-linked (alkaline phosphatase) oligonucleotide probe in HBV-DNA detection, we have first compared the results of the detection of serum HBV-DNA in 46 patients at different serological stages of HBV infection using this probe and with those obtained using a genomic P32-labeled probe. Fisher's test analysis of the results shows statistical significance; this indicates a high correlation between methods. Secondly, we have tested 296 sera of patients at different serological stages of HBV infection with the enzyme-linked probe; we have found HBV-DNA in 8 patients with acute hepatitis (61.54%), 61 HBeAg (70.12%), and 7 anti-HBe (12.07%) chronic hepatitis. These results show the value of this probe for routine survey of serum HBV-DNA using a simple method which avoids the use of radioactivity.

Alkaline Phosphatase

Etiologic study of patients with community-acquired pneumonia.

Community-acquired pneumonias are difficult to diagnose. For this reason, we have attempted to evaluate the correct diagnosis by using noninvasive methods which are easy to follow outside the hospital environment. To achieve this, 165 patients exhibiting the clinical and roentgenographic symptoms characteristic of pneumonia, have been studied from a bacteriologic, serologic, and statistical stand point. The correct diagnosis was made in 75 percent of the cases. Of the total 124 cases, 69 (41.8 percent) were of bacterial origin. Streptococcus pneumoniae was the most common agent, followed by Gram-negative bacilli. In 73 cases showing positive serologic evidence, 22 (42 percent) could be attributed to the so-called atypical pneumonias, 18.18 percent to the viral, and 1.21 percent to the mycotic.

Adolescent

[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

[Annual cost of microbial immunological tests for HIV-positive individuals in a hospital center].

The goal of this study is to increase the knowledge of the AIDS cost in a hospital. We have studied the HIV patients diagnosed during a year in our hospital and the charges of the serological tests performed to them. 20.8% of the tests were to study antibodies against HIV (only 20% were positive). After patient distribution between extra or intrahospital origin, we highlight that 61% of the charges are attributed to patients who do not belong to the hospital but to its catchment area. We emphasize the problem that AIDS patients are creating to hospital, being necessary that personal select only useful tests honestly.

AIDS Serodiagnosis

[Quantification of the levels of p24 antigen and antibodies in human immunodeficiency virus infection].

BACKGROUND: Quantification and clinical evaluation of p24 antigen and anti-HIV antibody levels. METHODS: Follow up of 13 HIV infected patients (53 sera) by determination of p24 antigen, total anti-HIV antibodies, anti-p24 and anti-env antibodies by ELISA and their semiquantitation. IgG and IgM class antibody determination by immunoblot techniques. RESULTS: The highest levels of p24 have been found in WR 1 and WR 6 stages. Commonly accepted serologic pattern has not been found in 100% of our cases. Western-blot is more sensitive for the detection of anti-p24 antibodies. CONCLUSIONS: p24 antigen appearance and a decrease in anti-p24 antibody level is related to a worse clinical prognosis. p24 antigen quantification is a usefull test for monitoring AZT therapy in patients suffering from AIDS.

Acquired Immunodeficiency Syndrome

Evaluation of the pre-S (pre-S(1)Ag/pre-S(2)Ab) system in hepatitis B virus infection.

The diagnostic and prognostic value of pre-S(1)Ag and pre-S(2)Ab was investigated in 69 HBsAg surface antigen positive patients--14 with acute hepatitis B, 30 with chronic liver disease (six chronic persistent hepatitis, 14 chronic active hepatitis, 10 with cirrhosis) and in 25 asymptomatic carriers. Pre-S(1)Ag was found in all patients with chronic hepatitis B virus (HBV) infection regardless of viral replication. In contrast, pre-S(2)Ab was not detected in any patients. Acute hepatitis was studied sequentially with periodic controls at 20 day intervals. Pre-S(1)Ag cleared before HBsAg in six of 14 (43%) patients who progressed favourably, and the two antigens cleared simultaneously in eight of 14 (57%) cases. Patients with early clearance of pre-S(1)Ag progressed favourably, thus indicating the prognostic value of this test, which, however, is still of limited practical application given the small temporal difference between the moment of clearance of the two antigens. The first markers to clear, however, were HBeAg and DNA-HBV, which showed significant differences with respect to the clearance of HBsAg. Moreover, pre-S(2)Ab appeared before HBsAb in 57.1% of our patients and was found in some patients before pre-S(1)Ag and HBsAg had cleared (42.8%), thus allowing complete viral clearance and acute HBV infection to be predicted earlier.

Biomarkers

A study of different parameters of cell-mediated immunity in patients with active and chronic tuberculosis.

A study was carried out on cell-mediated immunity in healthy persons and patients with tuberculosis in order to extend the diagnostic capacity in tuberculosis. We studied the relation between baciloscopy and the state of specific cell-mediated immunity in vivo (Mantoux) and in vitro (leukocyte migration inhibition assay with PPD-RT 23 to evaluate specific cell-mediated immunity and PHA to evaluate nonspecific immunity) in 131 patients with active tuberculosis, in 63 patients with chronic tuberculosis, in 62 healthy persons and 10 individuals living with tuberculosis patients. The results demonstrate that the percentage of reaction was very low in both tests, being of no statistical significance the difference between patients with active or with chronic tuberculosis, although it was significant in the control group. In about half of the patients with active tuberculosis a positive baciloscopy could be observed; the percentage was much lower in patients suffering from chronic tuberculosis, the difference between the two groups significant from a statistical point of view. At the same time when we carried out an evolutionary study in 10 patients with positive baciloscopy, we observed a slight capacity of conversion of immunity when the baciloscopy was negative.

Adolescent

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

A study of the evolution of specific and non-specific immune complexes in acute hepatitis B and chronic hepatitis.

Circulating immune complexes (ICs) containing IgG and HBsAg, and IgG and HBeAg, in sera from groups of patients with various liver diseases were sought by ELISA and immunodiffusion. A correlation was found between the absence of ICs and the disappearance of HBsAg in patients who had recovered from acute hepatitis B, but complexes containing HBsAg were always found in chronic hepatitis.

Antigen-Antibody Complex

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

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

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