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Biomedical subjects

J A Pineda

Publications and source records attributed to J A Pineda.

At least 19 recordsLinked to original sources
PubMed1992

[Multicenter study of the prevalence of type 2 human immunodeficiency virus infection in Spain (1990)].

BACKGROUND: HIV-2 is a new retrovirus which may produce AIDS and has been mainly described in individuals from West Africa. More than 400 cases have been reported in France and Portugal while in Spain very few cases of HIV-2 infection have been reported with few studies having been made concerning the prevalence of the disease. This multicentric study analyzes the prevalence of HIV-2 infection in subjects of different risk groups in Spain and evaluates the diagnostic efficacy of different methodologies. METHODS: The presence of HIV-2 antibodies was analyzed in 902 serum samples of high risk individuals collected in 1990 from: 386 drug addicts, 246 not drug addict prostitutes, 184 West Africans and 86 homo/bisexual individuals. These samples were from Barcelona, Sevilla, and Malaga. The detection of antibodies was carried out by enzymatic immunoanalysis (EIA), Western blot (WB) and an enzymoimmuno-dot (EID) designed with synthetic peptides. RESULTS: Positive serology only for HIV-2 was detected in 7 samples from African immigrants. Two drug addicts presented double reactivity HIV-1/HIV-2 in all the tests suggesting double infection. No prostitutes or homo/bisexual males were identified with positive serology for HIV-2. Cross-reactivity between HIV-1 and HIV-2 was more frequently detected in WB than in EID. Greater discordance was found in the results obtained by EIA, WB, and EID in the West Africans than in the analysis of the samples of native subjects. CONCLUSIONS: This study demonstrates that, for the time being, HIV-2 infection in Spain is rare although from among immigrants from endemic areas subjects with behavior to risk of transmission to the autochthonous population have been identified. The use of techniques designed with synthetic peptides may be of use to discriminate HIV-1 and HIV-2 infection in positive samples by enzymatic immunoanalysis (EIA) and Western blot which use a viral lysate as antigenic material.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Visual P3-like potentials in squirrel monkey: effects of a noradrenergic agonist.

Event-related potentials (ERPs) were recorded from squirrel monkeys (Saimiri sciureus) in a 90-10 visual "oddball" paradigm. A small, blue rectangle was presented every 2 s on 90% of the trials (background), whereas a yellow rectangle occurred on 10% on the trials (oddball). Electrical activity time-locked to these stimulus events was recorded from epidural electrodes before and following systemic administration of the alpha-2 noradrenergic agonist clonidine (0.1 mg/kg intramuscularly, IM). Baseline data in response to oddball stimuli showed a large, P3-like potential exhibiting a fronto-central maximum along midline electrodes and a parietal maximum along lateral electrodes. A frontally dominant, long-latency, negative slow wave (SN) consistently followed this P3-like potential. Amplitudes for P3 were larger following 10% than 50% probable oddball events. These results suggest that monkeys exhibit large, probability-sensitive P3-like potentials similar to the visual potentials reported in humans. Administration of clonidine had no effect on the amplitude, area, or latency of the monkey P3 component. This contrasts with our previous findings that the same dose of clonidine significantly decreases auditory P3s in these monkeys. Such differences may reflect distinct functional roles for norepinephrine in the processing of low-probability acoustic versus visual signals and argues against the hypothesis that norepinephrine is a common neurotransmitter substrate for auditory and visual P3-like potentials.

Animals↗
PubMed1992

HIV-1 infection among non-intravenous drug user female prostitutes in Spain. No evidence of evolution to pattern II.

OBJECTIVES: To assess the prevalence of HIV-1 infection among non-intravenous drug user (IVDU) female prostitutes in Spain and to determine risk factors for HIV-1 infection in this population. DESIGN: Cross-sectional seroepidemiological study of 519 non-IVDU prostitutes. SETTING: Four university hospitals. METHODS: All participants completed a questionnaire and provided a serum sample. Serum samples were tested for antibodies against HIV-1, hepatitis C virus (HCV) and Treponema pallidum. RESULTS: Twelve out of the 519 (2.31%) participants were HIV-1-seropositive. HIV-1 infection was associated with the presence of both HCV and T. pallidum antibodies, multiple sex partners, longer history of prostitution, history of genital ulcers and anal intercourse. Condom use was associated with HIV-1 seronegativity. CONCLUSIONS: The prevalence of HIV-1 infection in non-IVDU prostitutes in Spain remains relatively low. Risk increases with a higher rate of sexual exposure and practices such as anal intercourse and unprotected coitus.

Adolescent↗
PubMed1992

Visceral leishmaniasis in HIV-1-infected individuals: a common opportunistic infection in Spain?

OBJECTIVE: To investigate the epidemiological, clinical and biological features of visceral leishmaniasis (VL) in patients with HIV-1 infection. DESIGN: Retrospective study. SETTING: Three university hospitals in southern Spain. PATIENTS: Forty-seven adult patients with VL and HIV-1 infection diagnosed between January 1986 and November 1991. RESULTS: Forty-five out of the 47 (96%) cases were diagnosed in the last 2 years. Fever (87%), hepatomegaly (74%), splenomegaly (72%) and pancytopenia (77%) were the most common presenting features. Most patients (79%) were strongly immunocompromised when VL was diagnosed, and were in stage IV of the Centers for Disease Control classification; 87% had a CD4 lymphocyte count < 200 x 10(6)/l. However, VL was the first severe infection diagnosed in 10 cases. Significant titres (> 1:40) of antileishmanial antibodies were detected by indirect immunofluorescence in five out of 16 (31%) cases only. Clinical response to the therapy was difficult to assess. Microbiological response was achieved in only 38% of the patients evaluated. CONCLUSIONS: Leishmaniasis is a relatively common infection in HIV-1-infected individuals in southern Spain. Its clinical picture is quite uniform and it can be the first opportunistic infection in individuals with HIV-1. In endemic areas, a high index of clinical suspicion should be maintained in order to avoid underdiagnosis of leishmaniasis.

AIDS-Related Opportunistic Infections↗
PubMed1991

Absence of HTLV-I and HTLV-II infection in prostitutes in the area of Seville, Spain.

Infection with human retroviruses other than HIV in Spain has only been reported in isolated cases in African immigrants and intravenous drug abusers infected with HTLV-I. The status of the prostitute population is unknown. The sera of 88 prostitutes in Seville were therefore tested for HIV, HTLV-I and HTLV-II, and relevant epidemiological data were collected on the health status, sexual practices etc. In the prostitute population studied 2.5% of the non-intravenous drug abusers and 20% of the intravenous drug abusers were positive for HIV. However, infection with HTLV-I/II could not be demonstrated in any of them.

Adolescent↗
PubMed1991

Intensity-amplitude relationships in monkey event-related potentials: parallels to human augmenting-reducing responses.

In human, the amplitudes of specific event-related potential (ERP) components can increase or decrease in response to increasing stimulus intensity depending on the location of the recording site. Large increases characterize components presumably generated by modality-specific sites, while smaller increases or even decreases are associated with those originating in associational areas. Comparable data from non-human primates, which would permit invasive studies of the neural substrates underlying these intensity-amplitude differences, are limited. To more fully characterize these relationships, auditory ERPs were recorded from chronically implanted epidural electrodes in 5 squirrel monkeys (Saimiri sciureus) in response to tones (500 Hz, 300 msec duration) of varying intensities (50, 60, 70, 80 dB SPL). Squirrel monkey ERPs recorded at Fz exhibited 3 peaks during the 200 msec post-stimulus interval. These peaks included a positivity (P1), followed by a negativity (N1), and then another positivity (P2). At posterior sites, the frontal P1-N1 configuration was recorded as an N1-P1 complex. At these sites, a small negativity (N2) preceded the last positive peak (P2). Changes in polarity were independent of reference site and posterior N1-P1 peaks exhibited latencies similar to those of the frontal P1-N1 components. Amplitudes at Fz, Cz, and Pz increased substantially with increasing stimulus intensity ('augmenting'). In contrast, only small increases or even decreases in amplitude ('reducing') were evident at T3 and T4. On the other hand, peak latencies decreased with higher stimulus intensities at most sites. The site-specific amplitude responses exhibited considerable temporal stability. In one subject, for example, similar 'augmenting' profiles were recorded at Fz in 8 sessions over a 6-month period. The topography of monkey intensity-amplitude response profiles, their temporal stability, and peak latency shifts resemble observations made in humans. The data show that 'augmenting' characterizes monkey vertex potentials, which, like the analogous human potentials, may originate in primary auditory cortex. In contrast, potentials recorded over temporal cortex, which may originate in auditory association cortex, exhibit 'reducing.' Thus, the data support the hypothesis that differences in amplitude with increasing intensity may reflect differences in cortical origin.

Acoustic Stimulation↗
PubMed1991

Electrophysiological evidence for the involvement of the locus coeruleus in alerting, orienting, and attending.

In this chapter, we describe recent observations from our laboratory which support the thesis that the locus coeruleus (LC), via its massively divergent efferent projections, participates in generating a generalized brain state that can be characterized as "alertness." The first of these observations suggests that LC activation can convert the electroencephalographic (EEG) activity of the forebrain from patterns characteristic of a non-alert state to those characteristic of an alert state. The second observation indicates that LC activation alters sensory responses of individual neocortical neurons in a way that is compatible with the general thesis presented here, suggesting that LC-induced alterations in cortical neuronal activity may be an integral component of a hypothesized participation of the LC in cortically mediated attentional processes. The third observation indicates that LC may modulate forebrain components of orienting responses that are indexed by event-related potentials (ERPs). Thus, the experiments described below involve electrophysiological assessment of forebrain information processing at three different levels of organization: activity of individual neurons in the millisecond range, neuronal ensemble activity persisting for 10-200 msec as indexed by ERPs, and ensemble/regional activity sustained for seconds to minutes as indicated by EEG measures. These observations suggest that alterations induced in forebrain function by manipulations of LC activity are evident at all three of these levels.

Animals↗
PubMed1991

Therapeutic donor insemination: a prospective randomized study of scheduling methods.

OBJECTIVE: To compare basal body temperature (BBT) graphs and urinary luteinizing hormone (LH) monitoring in scheduling therapeutic donor insemination. DESIGN: Participants were prospectively randomized to the BBT or LH groups. SETTING: Participants were private patients of the Reproductive Endocrine Division at Washington University School of Medicine. PATIENTS: Inclusion criteria were designed to assure an isolated male factor. Seventy-four of 113 patients completed the study; 18 had ongoing treatment at the end of the study. INTERVENTIONS: Basal body temperature graphs were physician interpreted and appointments prospectively chosen. Luteinizing hormone patients monitored daily urine samples and scheduled an appointment the day after the detected surge. MAIN OUTCOME MEASURES: Fecundity rates, cumulative pregnancy rates, and cost per pregnancy were all prospectively evaluated. RESULTS: Life table analysis yielded a 6-month cumulative probability of pregnancy of 36.3% in the LH group and 65.1% in the BBT group (P less than 0.025). The total cost per pregnancy was lower in the BBT group (+6,212 versus +3,997; P less than 0.001). CONCLUSIONS: This randomized prospective study demonstrates significant therapeutic and economic advantages when therapeutic donor insemination is prospectively scheduled by BBT graphs.

Body Temperature↗
PubMed1990

[An evaluation of the efficacy of different commercial kits in the serological diagnosis of the early phase of human immunodeficiency virus infection].

The aim of the present study was to identify the most useful serum markers for the early identification of the infection by the human immunodeficiency virus (HIV). To this end, sequential serum samples of 19 individuals who later had seroconversion to anti-HIV were evaluated. The p24 antigen (Ag-HIV) was the earliest marker of the infection, although it could only be detected in five of the 19 individuals: in two as an isolated marker and in the remaining four associated to anti-HIV (first generation Western blot: WB-1, and recombinant enzyme immunoanalysis: EIA-2G). In 12 of the 19 individuals, WB-1G (Pasteur) was the technique which permitted the earliest detection of anti-HIV: in five cases with bands which made the unequivocal diagnosis of the infection, and in seven with indeterminate results (anti-HIV against core or envelope antigens). The second earliest test was the detection of anti-HIV against envelope antigens with a competitive EIA-2G (Abbott). WB-1G (Sorin) detected anti-HIV in a late phase, as it was the case for EIA-1G or EIA-2G for anti-HIV against antigens encoded by the GAG gene. These results indicate that there may be remarkable differences in sensitivity among the different commercial kits. The use of EIA for Ag-HIV together with WB-1G shortens the gap period of HIV infection, even if seroconversion is identified with EIA-2G for global anti-HIV.

AIDS Serodiagnosis↗
PubMed1990

[Classical heatstroke in Spain. Analysis of a series 78 cases].

Seventy-eight cases of classical heat stroke (HS) seen during the summer of 1988 and 1989 have been evaluated. The diagnosis was established on the basis of classically accepted criteria (severe hyperthermia, impairment of the level of consciousness, anhydrosis, exposure to high environmental temperature). 62.8% of patients were females, with a mean age of 75 +/- 12.3 years. All patients had predisposing factors and 57.7% was taking facilitating drugs. 86% of the patients had 2 or more predisposing or facilitating factors. In 45 cases there were prodromic features. The suspicion of HS was not raised in any of the referring services. Hyperglycemia was present in 89.7% of cases, increased blood urea in 85.9%, high creatine kinase in 74.3%, abnormal coagulation in 52.9%, hypernatremia in 46.2%, hyponatremia in 37.2%, hypokalemia in 35.9%, hyperkalemia in 23.1%, metabolic acidosis in 41.1% and respiratory alkalosis in 36.9%. Electrocardiogram was abnormal in 95.4%. 31 patients (39.7%) died. Death was more common in patients with deep coma, shock, and higher blood urea levels. The present study demonstrates the occurrence of this condition in our area.

Adult↗
PubMed1990

Hepatitis C virus infection in sexually promiscuous groups.

As there is insufficient data available on the spread of hepatitis C virus (HCV) infection by sexual transmission, the prevalence of anti-HCV was determined in several sexually promiscuous groups (78 female prostitutes, 55 clients of prostitutes and 146 homosexual men) who denied intravenous drug abuse. The overall HCV infection rate was much higher in the sexually promiscuous groups (8.97%, 16.36% and 5.48% respectively) than in voluntary blood donors (0.48%), suggesting that HCV infection can be transmitted by sexual intercourse. Consequently, promiscuity may be a risk factor for this infection.

Blood Donors↗
PubMed1990

Stereospecificity of hydrogen transfer between progesterone and cofactor by human placental estradiol-17 beta dehydrogenase.

We have previously shown that human placental estradiol-17 beta dehydrogenase (EC 1.1.1.62; 17 beta-EDH) catalyzes the conversion of estradiol-17 beta to estrone and stereospecifically reduces NAD+ to [4-pro-S]NADH, [( 4-B]NADH). Subsequently, this enzyme was found to reduce the ketone function at C-20 of progesterone, and evidence indicates that both activities reside at the same active site. This study was done to further elucidate spatial arrangements of cofactor and the 21-carbon substrate as they bind at the active site. The cofactor, [4B-3H]NADPH, was generated with homogeneous 17 beta-EDH from term human placenta, utilizing [17 alpha-3H]estradiol-17 beta and NADP+. The resulting [4B-3H]NADPH was then purified by ion exchange chromatography and was separately incubated (24.4 microM) with a large molar excess of progesterone (150 microM) as substrate in the presence of the enzyme. Following incubation, the steroid reactants and products were extracted, separated by high-performance liquid chromatography and quantitated as to mass and tritium content. Oxidized and reduced cofactor were separated by ion-exchange chromatography and similarly quantitated. In all incubations, equimolar amounts of 20 alpha-hydroxy-4-pregnen-3-one (20 alpha-OHP) and NADP+ were obtained. Radioactivity was stoichiometrically transferred from [4B-3H]NADPH to the steroid product [( 3H]20 alpha-OHP). These results further substantiate a single active site for both 17 beta- and 20 alpha-dehydrogenation enzyme activities. In addition, the enzyme is B-side specific, catalyzing the transfer of the 4B-hydrogen from the dihydronicotinamide moiety of the cofactor, for both C-18 and C-21 steroid substrates. Since the 20 alpha-dehydrogenation by other enzyme sources has always been demonstrated to be an A-side specific reaction, this observation represents an important exception to the Alworth-Bentley rules of enzyme stereospecificity.

Binding Sites↗
PubMed1989

[Serum and immunological markers of progression to acquired immunodeficiency syndrome in hemophiliacs].

In a cohort of 30 randomly selected hemophiliacs who were prospectively controlled for four years the predictive value of AIDS development was evaluated for serum markers of HIV infection and for lymphocytic subpopulations in peripheral blood. The patients were evaluated with a mean of 15.79 +/- 5.74 months, and overall antibodies, specific antibodies (anti-ENV and anti-p24), HIV antigen (Ag HIV) and lymphocyte subpopulations were determined. 50% of the hemophiliacs with positive serum Ag HIV (2/4) developed AIDS during the study, whereas this progression was not recorded in any anti-HIV positive, nonantigenic patient. The presence of Ag-HIV was detected at least two years before the diagnosis in these patients, and it was associated with the absence of anti-p24 in one or more determinations. The immune regulation parameters were not significantly different, at the beginning of the study, in the hemophiliacs who developed AIDS and in those who did not. However, the progression to AIDS was associated with a significantly smaller T4/T8 ratio at least one year before the diagnosis. Our results show that the development of AIDS in hemophiliacs is associated both with the presence of Ag-HIV in the serum and a reduction in the T4/T8 ratio, although the detection of the former appears to be earlier than that of the latter in this risk group.

Acquired Immunodeficiency Syndrome↗