Biomedical subjects
J Delgado
Publications and source records attributed to J Delgado.
Improvement of chronic renal failure after introduction of mycophenolate mofetil and reduction of cyclosporine dose.
Explore the source record for details and available documents.
Low levels of HIV-1 plasma viral load in patients infected with HIV-1 subtype b and advanced immunosuppression.
OBJECTIVES: Some HIV-1 infected patients show low levels of viraemia despite having advanced immunosuppression. Cases with falsely undetectable viraemia by conventional PCR have been reported when patients were infected with non-B subtypes. The aim of this study was to investigate whether this immunovirological discordance can be due to the presence of HIV-1 non-B subtypes, and whether a modified PCR procedure can yield different HIV viraemia values in these cases. METHODS: Fifteen HIV-infected patients either naive for antiretroviral drugs or under treatment, with HIV plasma viraemia below 1000 copies/mm(3)and CD4+ cell counts lesser than 500 or 300 cells/mm(3), respectively, were included. Serotyping, genotyping and HIV plasmatic viraemia determinations were performed in all individuals. RESULTS: In five out of six treatment-naive patients the virus was categorized as non-B subtype by serotyping, although only one case was confirmed by genotyping as HIV-2. Eight out of nine patients under antiretroviral therapy were subtype B carriers by serotyping and confirmed by genotyping. The remaining patient was determined as a subtype A carrier by both procedures. A modified PCR procedure (Amplicor HIV Monitor Test version 1.5) did not yield higher viral load levels than the former version. CONCLUSIONS: The presence of HIV-1 subtypes non-B can explain a minority of cases of this immunovirological discordance, but in most of them the reason is still unknown. Likewise, a PCR procedure adapted for detecting HIV-1 non-B subtypes fails to find higher plasma viraemia in patients with such a discordance.
Increased adhesiveness and internalization of Neisseria gonorrhoeae and changes in the expression of epithelial gonococcal receptors in the Fallopian tube of copper T and Norplant users.
Interaction of Neisseria gonorrhoeae with the oviductal epithelium in vitro was examined in 2 cm length segments obtained after surgical sterilization from users of copper T intrauterine device (IUD) or Norplant and control women. Segments perfused with N.gonorrhoeae suspensions were incubated from 30 min up to 4 h, fixed, frozen and cut in 6--10 microm sections. Bacteria were detected immunohistochemically with rabbit anti-gonococcal serum followed by light and confocal microscopy. Adhesion and internalization of gonococci by epithelial cells were observed at all incubation times, and both were higher in explants from users of copper T IUD or Norplant implants than controls. The epithelium of controls expressed CD66 and syndecan-1; but CD46 was found in only one out of six cases. The epithelium of copper T IUD users expressed CD66 but not syndecan-1 or CD46. Users of Norplant exhibited expression of CD46, CD66 and syndecan-1. Label was always found along the luminal border of the epithelium. There were more intraepithelial lymphocytes in users of contraceptive methods than in controls. Results indicate that (i) N.gonorrhoeae invade the oviductal epithelium from the first minutes of exposure, (ii) the epithelium is constitutively endowed with two known receptors for the gonococcus, CD66 and syndecan-1, (iii) copper T IUD and Norplant users exhibit higher rates of attachment and internalization of the gonococcus into the oviductal epithelium associated with changes in expression of gonococcal receptors.
PAF receptor and PAF acetylhydrolase expression in the endosalpinx of the human Fallopian tube: possible role of embryo-derived PAF in the control of embryo transport to the uterus.
BACKGROUND: Prostaglandin-E(2) and platelet-activating factor (PAF) are embryonic-derived signals that time embryo passage into the uterus in the mare and hamster respectively. PAF-like activity is detectable in the spent media of preimplantation human embryos and it has been suggested that PAF may be the embryonic signal that controls embryo transport to the uterus in our species. The actions of PAF are regulated at the level of its synthesis and degradation as well as the expression of a specific cell surface receptor (PAFr). The enzyme PAF acetylhydrolase (PAF-AH) degrades PAF. This study was undertaken to examine whether or not PAFr and PAF-AH are expressed in the human Fallopian tube and to identify the cell types in which they are expressed. METHODS: The presence of PAFr mRNA in tissue extracts was investigated using reverse transcription-polymerase chain reaction. We amplified the predicted amplicon for PAFr mRNA from RNA samples extracted from Fallopian tubes. The expression of PAF-AH was detected by Western blot and the localization of PAFr and PAF-AH proteins was detected by immunohistochemistry. RESULTS: Utilizing antibodies against PAFr and PAF-AH, co-localization of the two proteins in the epithelium and stromal cells were demonstrated. CONCLUSIONS: These observations show that the human Fallopian tube expresses PAFr and PAF-AH at a location compatible with the proposed paracrine role of early embryo-derived PAF.
Systemic and lung physiological changes in rats after intravascular activation of complement.
Systemic complement activation has been noted in a variety of shock states, and there is growing evidence that, in addition to being proinflammatory effectors, products of complement activation contribute directly to generalized manifestations of shock, such as hypotension and acidosis. To study the effects of complement activation, we examined responses in rats to systemic activation of complement with cobra venom factor (CVF), including blood pressure, metabolic acidosis, changes in vascular permeability, and lung function. High doses of CVF produced circulatory collapse (mean arterial pressure = 110 +/- 16 and 35 +/- 9 mmHg in control and with CVF, respectively, P < 0.05), metabolic acidosis (HCO concentration = 27.8 +/- 1.7 and 9.6 +/- 3.4 meq/l in control and with CVF, respectively, P < 0.05), extravasation of albumin into the lung and gut, and modest arterial hypoxemia (PO2 = 486 +/- 51 and 201 +/- 36 Torr in control and during 100% O2 breathing, respectively, P < 0.05). Prior depletion of complement protected against these abnormalities. Other interventions, including neutrophil depletion and cyclooxygenase inhibition, prevented lung injury but had much less effect on systemic hemodynamics or gut permeability, suggesting that complement activation products induce injury by neutrophil- and cyclooxygenase-dependent pathways in the lung but not in the gut. These studies underscore the significant systemic abnormalities developing after systemic activation of complement.
[Survey of the deficit of anesthesiologists in Catalonia and analysis of the situation made by 47 department heads].
Explore the source record for details and available documents.
Relapsing polychondritis and erythema elevatum diutinum: an unusual association refractory to dapsone.
Explore the source record for details and available documents.
Natural history of infection with Bartonella bacilliformis in a nonendemic population.
An investigation was performed after an outbreak of bartonellosis in a region of Peru nonendemic for this disorder. Symptoms of acute and chronic bartonellosis were recorded. Serological analysis was performed on 55% of the affected population (554 individuals), 77.5% of whom demonstrated previous infection with Bartonella bacilliformis. The attack rate of Oroya fever was 13.8% (123 cases); the case-fatality rate was 0.7%. The attack rate of verruga peruana was 17.6%. A new specific immunostain was developed and used to confirm the presence of B. bacilliformis in the biopsied skin lesions. Most seropositive individuals (56%) were asymptomatic. The symptoms that were associated with prior infection, as determined by Western blot, included fever (37.2% of the seropositive vs. 17.2% of the seronegative population; P<.001), bone and joint pain (27% vs. 9%; P<.001), headache (27% vs. 12.3%; P <.001), and skin lesions described as verruga peruana (26.8% vs. 4.9%; P<.001). Our findings suggest that infection with B. bacilliformis causes a broad spectrum of disease that is significantly milder in severity than that frequently reported.
Self-synchronization and task fulfilment in ant colonies.
Some authors have hypothesized that the observed self-synchronized activity in ant colonies provides some adaptive advantages, and, in particular, it has been suggested that task realization may benefit from this ordered temporal pattern of behaviour (Robinson, 1992, Ann. Rev. Entomol, 37, 637-702; Hatcher et al., 1992, Naturwissenschaften, 79, 32-34). In this paper, we use a model of self-synchronized activity (the fluid neural network) to suggest that with self-synchronized patterns of activity a task may be fulfiled more effectively than with non-synchronized activity, at the same average level of activity per individual.
Comparative analysis of TMV-Cg and TMV-U1 detection methods in infected Arabidopsis thaliana.
The common strain of the tobacco mosaic virus (TMV-U1), and the crucifer-infecting tobacco mosaic virus (TMV-Cg), both members of Tobamovirus genus, infect efficiently the solanaceous plants such as tomato and tobacco. The crucifer-infecting tobacco mosaic virus (TMV-Cg) also infects Arabidopsis thaliana plant, spreading systemically without causing severe symptoms. In contrast, Arabidopsis is a poor host for TMV-U1 infection. Within the past 10 years, Arabidopsis has developed into a powerful model system for studying plant-pathogen interaction. However, a detailed analysis comparing the accuracy of various viral detection methods has not been reported previously. Four detection methods were evaluated in A. thaliana (ecotype Po-1), infected with TMV-U1 or TMV-Cg. Western blots, enzyme-linked immunosorbent assay (ELISA), reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ RNA hybridization methods were used to determine viral spread at various days post inoculation (dpi) in inoculated and apical non-inoculated leaves. The detection of viral spread of TMV-U1 and TMV-Cg in Arabidopsis, using these four detection methods, supports previous studies, which demonstrate that the systemic spreads of these two viruses differ in Arabidopsis. Western blotting and ELISA detected TMV-Cg at 5dpi, and TMV-U1 at 12 dpi in systemic tissues. Viral spread was detected earlier when using RNA detection methods. Reverse transcriptase-polymerase chain reaction (RT-PCR) was very sensitive for detecting TMV-Cg in A. thaliana, but less sensitive for TMV-U1 detection. In situ RNA hybridization showed differential distribution of TMV-Cg and TMV-U1 in the inoculated leaf and systemic tissues.
Allergenic cross-reactivity in the Liliaceae family.
Explore the source record for details and available documents.
Prevalence of sensitization to Tetranychus urticae in greenhouse workers.
BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which infests a large number of plants of economic interest worldwide. It has recently been described as a cause of occupational allergic disease in greenhouse workers. However, there are no epidemiological data concerning the prevalence of TU allergy in an unselected exposed population. OBJECTIVE: The aims were to study the prevalence of TU sensitization among greenhouse workers and its relationship to the working environment and to personal factors. METHODS: We studied 246 consecutive greenhouse workers, recruited directly from the field. A clinical and epidemiological questionnaire, a skin-prick test (SPT) to TU and common allergens and TU-specific IgE (RAST) determinations were performed. Seventy-five healthy volunteers and 152 atopic patients were used as a control group. RESULTS: The prevalence of a positive SPT to TU was of 25%. Forty-five workers (19%) were TU-allergic, occurring more often in atopic greenhouse workers (P < 0.0001). Seven per cent showed asymptomatic sensitization. The time of exposure to TU was significantly greater in the TU-allergic patients (P < 0.05). The probability of sensitization to TU was 3.7 times greater in exposed than in non-exposed subjects (P < 0.0001). CONCLUSIONS: In this study, the prevalence of TU sensitization was 25%. There were significant associations with TU allergy and atopy and the time of exposure to TU.
Left circumflex coronary artery-to-left atrium fistulas detected by transesophageal echocardiography in heart transplant recipients.
Coronary fistulas are uncommon after heart transplantation. We report two cases of fistulas from an atrial branch of the circumflex coronary artery to the left atrium after heart transplantation. This has not been previously reported in the literature. They were detected with transesophageal echocardiography, and images are shown for the first time. Transesophageal echocardiography may be useful in the follow-up of heart transplant recipients.
Sonicated diagnostic immunoblot for bartonellosis.
Two simple Bartonella bacilliformis immunoblot preparation methods were developed. Antigen was prepared by two different methods: sonication of whole organisms or glycine extraction. Both methods were then tested for sensitivity and specificity. Well-defined control sera were utilized in the development of these diagnostic immunoblots, and possible cross-reactions were thoroughly examined. Sera investigated for cross-reaction with these diagnostic antigens were drawn from patients with brucellosis, chlamydiosis, Q fever, and cat scratch disease, all of whom were from regions where bartonellosis is not endemic. While both immunoblots yielded reasonable sensitivity and high specificity, we recommend the use of the sonicated immunoblot, which has a higher sensitivity when used to detect acute disease and produces fewer cross-reactions. The sonicated immunoblot reported here is 94% sensitive to chronic bartonellosis and 70% sensitive to acute bartonellosis. In a healthy group, it is 100% specific. This immunoblot preparation requires a simple sonication protocol for the harvesting of B. bacilliformis antigens and is well suited for use in regions of endemicity.
Pattern formation and optimization in army ant raids.
Army ant colonies display complex foraging raid patterns involving thousands of individuals communicating through chemical trails. In this article we explore, by means of a simple search algorithm, the properties of these trails in order to test the hypothesis that their structure reflects an optimized mechanism for exploring and exploiting food resources. The raid patterns of three army ant species, Eciton hamatum, Eciton burchelli, and Eciton rapax, are analyzed. The respective diets of these species involve large but rare, small but common, and a combination of large but rare and small but common food sources. Using a model proposed by Deneubourg et al. [4], we simulate the formation of raid patterns in response to different food distributions. Our results indicate that the empirically observed raid patterns maximize return on investment, that is, the amount of food brought back to the nest per unit of energy expended, for each of the diets. Moreover, the values of the parameters that characterize the three optimal pattern-generating mechanisms are strikingly similar. Therefore the same behavioral rules at the individual level can produce optimal colony-level patterns. The evolutionary implications of these findings are discussed.
4-Pyridin-5-yl-2-(3,4,5-trimethoxyphenylamino)pyrimidines: potent and selective inhibitors of ZAP 70.
Activation of the tyrosine kinase ZAP 70 has been shown to be crucial to the transduction of the T-cell receptor signalling pathway, which leads ultimately to proliferation, cytokine gene expression and T-cell effector functions. A series of 2-phenylaminopyrimidines have been identified as potent and selective inhibitors of ZAP 70.
Measurement of sarcoplasmic reticulum Ca2+-ATPase activity and E-type Mg2+-ATPase activity in rat heart homogenates.
The presence of a high and nonlinear Ca2+-independent (or basal) ATPase activity in rat heart preparations makes difficult the reliable measurement of sarcoplasmic reticulum (SR) Ca2+-ATPase activity by usual methods. A spectrophotometric assay for the accurate determination of SR Ca2+-ATPase activity in unfractionated homogenates from rat heart is described. The procedure is based on that reported by Simonides and van Hardeveld (1990, Anal. Biochem. 191, 321-331) for skeletal muscle homogenates. To avoid overestimation of the Ca2+-ATPase activity of cardiac homogenates that occurs when sequential measurements of total and basal ATPase activities are performed, two parallel and independent assays are required: one with low (micromolar) and other high (millimolar) calcium concentration. Addition of thapsigargin (0.2 microM) blocked totally the activity considered as Ca2+-ATPase activity. Using this method, the rat heart homogenate Ca2+-ATPase activity was 10.5 +/- 2.0 micromol. min-1 x g-1 tissue wet weight (n = 8). Likewise, a spectrophotometric assay for measuring E-type Mg2+-ATPase activity in cardiac total homogenates has been developed, comparing the following characteristics of the enzymatic activity in homogenate and a membrane-enriched fraction: first-order rate constant for ATP-dependent inactivation, Km for ATP, and effects of concanavalin A, Triton X-100, and specific inhibitors.