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J Mosquera

Publications and source records attributed to J Mosquera.

At least 19 recordsLinked to original sources
PubMed2003

[Sinusitis in immunocompromised patients. A multicenter study].

This paper evaluates different aspects of sinusitis in patients with a decreased immunological system, such as its prevalence and clinical evolution, its peculiar bacteriology and the altered response to treatment, and the prognosis, especially in patients with AIDS. There seems to be an increased prevalence of sinusitis in these patients, with a relationship between their immunological status and the severity and aggressiveness of the sinusitis. Bacteriological studies reveal the pressure of more aggressive species, such as P. aeruginosa, and specific sinusitis are more frequent, which may explain why the treatment with common antibiotics often remains uneffective. The simultaneous therapy of concomitant infections leads to a higher resistance towards common drugs. A standard treatment is therefore needed. The results of three studies, retrospective and prospective, on HIV-infected patients reveal a high incidence of acute sinusitis with aggressive bacteria.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Quantitative ultrasound calcaneus measurements: normative data and precision in the spanish population.

Quantitative ultrasound (QUS) assessment at the calcaneus has been found to be a safe and reliable method for evaluating skeletal status. In this study we have determined the normative QUS data in the Spanish population for the Sahara Clinical Sonometer (Hologic). Broadband ultrasound attenuation (BUA), speed of sound (SOS), quantitative ultrasound index (QUI) and estimated bone mineral density (BMD) were determined. We also studied the precision in vivo and in vitro. The short-term in vivo precision (CV) was 4.88% for BUA, 0.36% for SOS, 3.45% for QUI and 4.15% for BMD, while in vitro precision was 0.40% for SOS and 2.67% for BUA. Our results are comparable to reference population data previously published in other countries and may serve as reference normative data for both genders in Spain.

Adolescent↗
PubMed2002

In vitro interaction of terbinafine with itraconazole, fluconazole, amphotericin B and 5-flucytosine against Aspergillus spp.

We investigated the in vitro interaction of terbinafine with itraconazole, fluconazole, amphotericin B and 5-flucytosine, against Aspergillus spp. We tested three isolates of Aspergillus fumigatus (one resistant to itraconazole), and two each of Aspergillus flavus, Aspergillus niger and Aspergillus terreus. We employed a broth microdilution-based method derived from an in vivo validated method capable of detecting itraconazole resistance in A. fumigatus. We studied the effect on the MICs by calculation of the fractional inhibitory concentration (FIC) and fractional fungicidal concentration (FFC) (99.99% kill). Itraconazole and terbinafine were synergic or additive in all strains (FIC = 0.15-1.0). Fluconazole and terbinafine were synergic with A. fumigatus, A. terreus and A. flavus (FIC = 0.3-0.5) and indifferent with A. niger (FIC = 2) isolates. Amphotericin B and terbinafine were mostly indifferent or antagonistic (FIC = 1.0-4.02). Flucytosine and terbinafine were usually indifferent or antagonistic (FIC = 0.63-8.5). FFCs were generally in accord with FICs. The use of terbinafine in combination therapy for Aspergillus infections with azoles seems promising, whereas terbinafine and amphotericin B or flucytosine in combination were less effective.

Amphotericin B↗
PubMed2002

Azole cross-resistance in Aspergillus fumigatus.

We susceptibility tested 17 clinical isolates of Aspergillus fumigatus, for most of which MICs of itraconazole were elevated (MIC at which 50% of the isolates tested are inhibited, 16 microg/ml), against itraconazole, posaconazole, ravuconazole, and voriconazole. Posaconazole was the most active against itraconazole-susceptible isolates. A complex pattern of cross-resistance and hypersusceptibility was seen with voriconazole and ravuconazole, suggesting marked differences in activity and mechanisms of resistance.

Antifungal Agents↗
PubMed2001

Treatment of Absidia corymbifera infection in mice with amphotericin B and itraconazole.

The activities of amphotericin B and itraconazole were studied in a temporarily neutropenic murine model of disseminated Absidia corymbifera infection, caused by two different strains. Amphotericin B MICs were 0.25 mg/L for both strains and itraconazole MICs were 1 and 2 mg/L. Amphotericin B was effective in vivo with both isolates. Itraconazole was less effective.

Absidia↗
PubMed2001

Susceptibility testing of Aspergillus flavus: inoculum dependence with itraconazole and lack of correlation between susceptibility to amphotericin B in vitro and outcome in vivo.

We have attempted to validate in Aspergillus flavus the main in vitro methodologies that have been used to detect resistance in Aspergillus fumigatus. We developed a murine model with two A. flavus isolates, one that was apparently resistant in vitro to amphotericin B (AFL5) and another that was resistant to itraconazole (AFL8). No correlation was found for amphotericin B in AFL5, since the in vivo response was compatible with a susceptible isolate. Modification of the in vitro susceptibility test methodology for amphotericin B was unsuccessful. Although AFL8 was apparently resistant to itraconazole in vitro, it was found to be susceptible in vivo. Additional in vitro work has detected weaknesses in the in vitro susceptibility methodology validated for A. fumigatus when applied to A. flavus. The principal problems are that changes in the inoculum have a large effect on the MICs of itraconazole for some A. flavus strains and that a trailing end point and spore sediment often appear when an inoculum with a higher colony count is used. We propose a modified method using a final inoculum of 2.5 x 10(4) CFU per ml of RPMI 1640 medium with 2% glucose buffered to pH 7.0 in a microtiter format, incubated for 48 h with no growth end point. Validation of this methodology requires one or more itraconazole-resistant A. flavus isolates, which have yet to be identified.

Amphotericin B↗
PubMed2000

Using parasites as biological tags of fish populations: a dynamical model.

A simple model of macro-parasitic infections has been used to evaluate the potential use of parasites as biological tags of fish populations. In the model, the parasite-host interaction is regulated by a birth-death process, and parasites can only be acquired by the non-specific migratory host population in a particular area of the space domain. In this case, we show that parasites can be successfully used for stocks identification and to describe the migratory routes taken by some marine fish species.

Animals↗
PubMed2000

Kinetics of accelerated solid-state fermentation of organic-rich municipal solid waste.

Biotransformation of landfill solid wastes is a slow process requiring decades for completion. Accelerated anaerobic fermentation in modulated landfill environments may alleviate or eliminate pollution of land, water and air. This research was undertaken to demonstrate the application of biphasic fermentation to a simulated laboratory-scale landfill to effect rapid biomethanation of biodegradable solids. The biphasic process consisted of solid-state, acidogenic fermentation of the organic fraction of MSW followed by biomethanation of acidic hydrolysates in a separate methane fermenter. Solid-state fermentation of the MSW with effluent recirculation resulted in rapid hydrolysis, acidification and denitrification, with soluble COD and VFA concentrations accumulating to inhibitory levels of 60,000 mg/l and 13,000 mg/l, respectively, at a pH of 4.5. The landfill gas methane concentration reached a maximum of 55 mol.%. By comparison, the methanogenic reactor produced high methane-content (70-85 mol.%) gases. The biphasic process effected carbohydrate, lipid, and protein conversion efficiencies of 90%, 49%, and 37%, respectively. Development of a Monod-type product-formation model was undertaken to predict methane formation and to determine kinetic parameters for the methanogenic processes in the simulated landfill and separate methane reactors. A first-order solids hydrolysis rate constant of 0.017 day-1 was evaluated to show that landfill solids hydrolysis was slower than the inhibited methanogenesis rate.

Bacteria, Anaerobic↗
PubMed1999

Erythrogenic toxin type B and its precursor isolated from nephritogenic streptococci induce leukocyte infiltration in normal rat kidneys.

BACKGROUND: Leukocyte infiltration is a common feature in renal biopsies from patients with acute poststreptococcal glomerulonephritis (APSGN). Cationic streptococcal erythrogenic toxin type B (ETB) and its precursor (ETBP) have been implicated in the pathogenesis of the disease, and the presence of ETB has been evidenced in renal biopsies from patients with APSGN. The present studies were performed to determine the effect of the ETBP and ETB on renal leukocyte infiltration and the mechanism(s) implicated in the phenomenon. METHODS: Male Sprague-Dawley rats were injected intrarenally with 100 microg of ETB or ETBP. Animals were sacrificed at 1, 6 and 24 h after injection and renal samples were studied by indirect immunofluorescence for the presence of leukocyte common antigen (LCA+) cells, C3, monocyte chemotactic protein-1 (MCP-1) and intercellular adhesion molecule-(ICAM-1), and by direct immunofluorescence for the presence of immunoglobulins. ETB and ETBP were tested for chemotactic effect and migration inhibition factor (MIF) activity by chemotaxis under agarose and agarose microdroplet methods, respectively. Streptococcal proteins were also tested for the capacity to induce MIF activity in rat glomerular cultures. To test for the influence of cationic charge on renal LCA+ cell infiltration, rats were injected with cationized ferritin or polyethyleneimine (PEI) and sacrificed 1 h later. RESULTS: An increased number of LCA+ cells was found in glomeruli and interstitial areas in ETB- or ETBP-injected animals. ETB and ETBP showed chemotactic and MIF activity on neutrophils and macrophages, and ETBP induced MIF activity in supernatants of glomerular cultures. Data obtained from C3, MCP-1, ICAM-1 or immunoglobulin renal staining in experimental animals were not significantly different when compared to control values. Cationized compounds failed to induce LCA+ cell infiltration; however, an increased number of glomerular LCA+ cells was observed after PEI perfusion. CONCLUSIONS: ETB and ETBP induce renal LCA+ cell infiltration during a short period after intrarenal injection, and this finding could be mediated by chemotactic and MIF activities. These observations could be relevant in the early events of pathogenesis of APSGN.

Animals↗
PubMed1998

Evolution of virulence: a unified framework for coinfection and superinfection.

Models of the evolution of parasite virulence have focused on computing the evolutionarily stable level of virulence favored by tradeoffs within a host and by competition for hosts, and deriving conditions under which strains with different virulence levels can coexist. The results depend on the type of interaction between disease strains, such as single infection (immunity of infected individuals to other strains), coinfection (simultaneous infection by two strains), and superinfection (instantaneous takeover of host by the more virulent strain). We present a coinfection model with two strains and derive the superinfection model as the limit where individuals are rapidly removed from the doubly-infectious class. When derived in this way, the superinfection model includes not only the takeover of hosts infected by the less virulent strain, but new terms which take into account the possibility of increased mortality of doubly-infected individuals. Coinfection tends to favor higher virulence and support more coexistence than the single infection model, but the detailed results depend sensitively on two factors: (1) whether and how the model is near the superinfection limit, and (2) the shape of the coinfection function (the function describing the rate at which a more virulent strain can infect a host). If the superinfection limit arises due to rapid mortality of doubly-infected hosts, there is a region of uninvadable virulence levels rather than coexistence. When the coinfection function is discontinuous, as in many previous models, neither the coinfection model nor the superinfection limit can support an evolutionarily stable virulence level. Piecewise differentiable and differentiable coinfection functions produce qualitatively different results, and we propose that these more general cases should be used to study evolution of virulence when other mechanisms like space, population dynamics, and stochasticity interact.

Animals↗
PubMed1997

A simple method to identify NBT-positive cells in isolated glomeruli.

BACKGROUND: Reactive oxygen radicals are probably involved in the pathogenesis of human and experimental models of renal disease, yet current methods are inadequate to quantify and identify the cells producing reactive oxygen radicals. METHODS AND RESULTS: We used the nitroblue tetrazolium reaction to determine superoxide anion production in glomerular cells in phorbol myristate-stimulated glomerular suspensions and in isolated glomeruli from rats with nephrotoxic nephritis, ureteral obstruction, and puromycin aminonucleoside nephrosis. We were also able to identify these nitroblue tetrazolium + cells using specific appropriate antibodies. When the technique was tested in conditions known to increase reactive oxygen radicals, as phorbol myristate-stimulated glomeruli and glomeruli from animals with nephrotoxic nephritis and ureteral obstruction, increased number of nitroblue tetrazolium + cells were found. These cells were identified as glomerular intrinsic cells (Thy-1 +) or infiltrating leukocytes (leukocyte common antigen + or antineutrophil +). CONCLUSION: This method may be useful to determine cells participating in glomerular damage induced by reactive oxygen radicals.

Animals↗
PubMed1997

Apoptosis in proliferative glomerulonephritis: decreased apoptosis expression in lupus nephritis.

BACKGROUND: Apoptosis is a mechanism of cellular death involved in the deletion of cells in hyperplasic processes which has been observed in proliferative glomerulonephritis. Patients with systemic lupus erythematosus (SLE) are known to have defective apoptosis but there is scarce information about apoptosis in the renal lesions of this disease. The present studies were done to evaluate apoptosis in relation to the intensity of proliferation in several glomerulonephritis and the possible association between this relationship and the chronic histologic changes in lupus nephritis. METHODS: Studies were done in renal biopsies from 19 patients with lupus nephritis (types, IV, Va, Vb) classified with respect to chronicity and activity indexes, five patients with acute poststreptococcal glomerulonephritis, five with idiopathic mesangioproliferative glomerulonephritis, four with membranous glomerulonephritis, four with minimal-change nephrotic syndrome, and three patients with focal segmental sclerosis. Seven normal kidneys which could not be used for transplantation were used as a control group. Apoptosis was determined by in situ DNA nick-end labelling techniques and proliferating cells were identified with a monoclonal antibody antiproliferating cell nuclear antigen (PCNA). RESULTS: Decreased number of apoptotic cells and a high ratio of PCNA: apoptosis were observed in glomerulus and tubulointerstitium of patients with lupus nephritis when compared to other proliferative glomerulonephritis and controls. In lupus nephritis, glomerular apoptosis had a negative correlation with the chronicity index (r = -0.606 P = 0.005). The number of apoptotic cells in the glomeruli was not correlated with the number of PCNA positive cells in lupus nephritis, in contrast with a striking linear correlation observed in acute poststreptococcal nephritis (r = 0.925, P = 0.024), a disease with excellent prognosis. CONCLUSIONS: Apoptosis is decreased in proliferative lupus nephritis. Intense proliferation without increment in apoptosis (a high PCNA: apoptosis ratio) is a characteristic of lupus nephritis associated with chronic renal histological changes.

Adolescent↗
PubMed1997

Histological evidence of neuraminidase involvement in acute nephritis: desialized leukocytes infiltrate the kidney in acute post-streptococcal glomerulonephritis.

Serum neuraminidase (NA, sialidase) activity has been demonstrated in acute poststreptococcal glomerulonephritis (APSGN) and implicated in the pathogenesis of the disease. Recent investigations show that neuraminidase-treated leukocytes accumulate preferentially in kidneys; therefore, we were interested in knowing if desialized cells infiltrate the kidney in APSGN. We first tested the capacity of peanut agglutinin lectin (PNA) to detect injected NA-treated leukocytes in the kidney of rats. NA-treated leukocytes were transfused and desialized cells were identified with fluorescein-conjugated peanut lectin (FITC-PNA) in renal tissue. PNA positive cells were identified in rat kidneys 3 hours after injection (glomeruli: 1.67 +/- 0.19 cells/g.c.s.; interstitium: 0.50 +/- 0.12 cells/int). Sections from available renal biopsy material of APSGN (n = 11), other glomerulonephritis (n = 28) and normal kidneys (n = 5) were double-stained with FITC-PNA and with monoclonal antibody to the CD11b molecule, which is expressed on polymorphonuclear and monocytes the main types of infiltrating cells during APSGN. Desialized (FITC-PNA positive) cells were found in the glomeruli (2.17 +/- SEM 0.22 cells per glomerular cross section, g.c.s.) and interstitium (0.61 +/- 0.15 cells per 0.0625 mm2, int) in all biopsies of APSGN. Only in 2 of 28 other glomerulonephritis showed desialized cells. More than 80% of the PNA positive cells in APSGN expressed the CD11b molecule and the infiltration was more intense in early biopsies. In conclusion, desialized leukocytes represent a significant part of the inflammatory infiltrate in APSGN. This finding gives support for a role of NA in the disease and provides clinical validation for a mechanism of renal cellular infiltration suggested by experimental observations.

Animals↗
PubMed1995

Amyloid goitre: CT and MR findings.

Two cases of amyloid goitre presented as an enlarged thyroid mass with cystic components. Solid parts of the goitre showed high attenuation on computed tomography (CT) and moderate hypointensity on T1 and T2-weighted images. Fine needle aspiration was negative for amyloid, but pathological studies of surgical specimens demonstrated amyloid infiltration of the thyroid interstitium and regressive colloid cysts. In a patient at risk for systemic amyloidosis, thyroid enlargement with a cystic component suggests amyloid goitre. In this case, needle biopsies should be directed to solid areas of the mass because amyloid material may not be present in the cysts.

Adult↗
PubMed1995

Neuraminidase promotes neutrophil, lymphocyte and macrophage infiltration in the normal rat kidney.

Neuraminidase (NA) is an enzyme produced by several microorganisms, which is capable of liberating sialic acid from glycoproteins and modifying cellular adhesion mechanisms. NA is considered a virulence factor in some bacterial species and has been implicated in the pathogenesis of acute poststreptococcal glomerulonephritis, a disease in which glomerular leukocyte infiltration is a prominent feature. We examined the effect of NA on kidney infiltration by neutrophils (PMN), T lymphocytes (TL) and monocyte-macrophages (MM). Intravenous injection of NA resulted in an early increase in the number of PMN (1 hr, 3.42 +/- 0.19 cells/cgs, mean +/- SEM; 3 hr, 3.63 +/- 0.13; 6 hr, 2.9 +/- 0.24; controls, 1.53 +/- 0.18; P < 0.001) and MM (1 hr, 3.49 +/- 0.16; 3 hr, 4.02 +/- 0.2; 6 hr, 3.88 +/- 0.27; controls 1.43 +/- 0.14; P < 0.001) in the glomeruli, while TL increased later (24 hr, 2.29 +/- 0.14; 48 hr, 2.4 +/- 0.2; 72 hr, 2.16 +/- 0.15; controls 0.7 +/- 0.07; P < 0.001). PMN and TL were also increased in the interstitium (up to ninefold for PMN and up to threefold for TL). Following i.v. injection of 51Cr-labeled NA-treated leukocytes, renal radioactive uptake was significantly increased at all times tested (percent radioactivity/gram of tissue after PMN injection, 3 hr, 5.57 +/- 0.46, mean +/- SEM; 12 hr, 5.38 +/- 0.77; 60 hr, 6.51 +/- 1.1; controls, 1.26 +/- 0.17, 1.75 +/- 0.25, and 2.46 +/- 0.08, respectively; P < 0.001 in each case.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Nutritional status and cutaneous leishmaniasis in rural Ecuadorian children.

The relationship between nutritional status and cutaneous leishmaniasis (CL) was evaluated in 230 children living in a rural subtropical rainforest in Northwest Ecuador. One-third of the subjects had evidence of either current (13 per cent) or past CL infection (21 per cent). Subjects with current (4.71 +/- 0.44 mg) or previous disease (4.29 +/- 0.35 mg) had lower mean daily dietary iron intakes than non-infected children (5.45 +/- 0.2 mg; chi 2 = 0.048), but not energy, protein, or other micronutrients. The low dietary iron intake data was corroborated by the reduced mean haemoglobin values observed in children with current (11.7 +/- 0.3 mg/dL) or past infection (11.3 +/- 0.2 mg/dL) compared to non-infected subjects (12.7 +/- 0.15 mg/dL; F-ratio = 17.0, P < 0.0001). Mean hematocrit values were also lower in the two infected groups (37.4 +/- 0.9 per cent and 37.4 +/- 0.6 per cent v. 39.5 +/- 0.5 per cent; F-ratio = 4.23, P = 0.0175). Furthermore, they were more likely to suffer from iron-deficiency anaemia than their non-infected counterparts (chi 2 = 4.64, P = 0.03). However, the children with active disease accounted for most of the excess risk for anemia (Fisher's exact test P = 0.009; OR = 10.0, exact 95 per cent CI = 1.37-111.8). Finally, growth stunting (< -2SD height-for-age) was more common in subjects with current (54 per cent) or past infection (51 per cent) compared to those without CL history (31 per cent; chi 2 = 8.03, P = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Iron-Deficiency↗