Search PubMed⌕ Search

Biomedical subjects

J Blanco

Publications and source records attributed to J Blanco.

At least 55 records · Page 3Linked to original sources
PubMed2003

Application of the colloidal stability of TiO2 particles for recovery and reuse in solar photocatalysis.

TiO2-catalyst suspensions work efficiently in photocatalysis for wastewater treatment. Nevertheless, once photocatalysis is complete, separation of the catalyst from solution becomes the main problem. Catalyst recovery has been enhanced through charge neutralisation and coagulation with electrolytes at lab and pilot-plant scale (40 L) to evaluate the potential for its separation after photocatalytic degradation of pollutants. Zeta-potential analysis showed that the isoelectric point (IEP) of TiO2 suspensions is near pH 7. Settling rates and hydrodynamic diameter of TiO2 particles are maximum at the IEP. However, suspensions are stable at different pH. TiO2 was reused in solar photocatalysis pilot-plant (40 L) for treatment of tetrachloroethylene (C2Cl4) comparing two procedures: reuse of the entire suspension after destruction of the organics without separation of the catalyst, and reuse of the catalyst after it had settled to the bottom and clear water had been removed. Photocatalytic efficiency worsens with successive runs when catalyst and water are reused without separation, whereas, when TiO2 is separated, the photocatalyst is not deactivated.

Catalysis↗
PubMed2003

Genetic analysis of sperm and implications of severe male infertility--a review.

The use of fluorescence in situ hybridization (FISH) on decondensed sperm heads has allowed to analyse the chromosome constitution of spermatozoa in different populations. In controls, the mean incidence of disomy (including all chromosomes) is about 6.7 per cent; diploidy increases with age, and some individuals may show a special tendency to nondisjunction. Carriers of numerical sex chromosome anomalies show a low incidence of sex chromosome disomies (2.54-7.69 per cent), and the need to screen ICSI candidates for these conditions has to be reconsidered. Carriers of inversions produce from 0 to 54.3 per cent abnormal sperm. Carriers of Robertsonian translocations produce from 3.4 to 36.0 per cent abnormal sperm, and carriers of reciprocal translocations produce from 47.5 to 81.0 per cent abnormal spermatozoa. However, carriers of translocations usually produce more abnormal embryos than expected from these figures. This may be partly related to interchromosomal effects induced by some structural reorganizations. Males with oligoasthenozoospermia, low motility and/or high FSH concentrations show frequent synaptic anomalies, resulting in the production of aneuploid and diploid sperm. Testicular sperm show extremely high rates of chromosomal abnormalities. The risk of recurrent abortion is increased by the presence of chromosome abnormalities in sperm.

Cell Nucleus↗
PubMed2003

Prevalence and characterization of Vero cytotoxin-producing Escherichia coli isolated from diarrhoeic and healthy sheep and goats.

Faecal samples from 146 diarrhoeic lambs and goat kids, and from 511 healthy sheep and goats were screened for the presence of Vero cytotoxin-producing Escherichia coli (VTEC). In healthy sheep and goats, VTEC were isolated in 24.4 and 16.2% of the animals, respectively. Moreover, VTEC were detected in 3.1 and 5.9% of the diarrhoeic lambs and goat kids, respectively. These data suggest that VTEC seems not to be associated with diarrhoea in lambs and goat kids. Only four VTEC strains were eae-positive. The absence of the eae gene in most of these VTEC strains could indicate that these strains are less virulent for humans that the classical eae-positive enterohaemorrhagic E. coli types. However, almost half (42.9%) and 12.2% of VTEC strains isolated from healthy sheep and goats, respectively, belonged to serotypes associated with severe diseases in humans.

Adhesins, Bacterial↗
PubMed2003

Serotypes, virulence genes, and intimin types of Shiga toxin (verotoxin)-producing Escherichia coli isolates from healthy sheep in Spain.

Fecal swabs obtained from 1,300 healthy lambs in 93 flocks in Spain in 1997 were examined for Shiga toxin-producing Escherichia coli (STEC). STEC O157:H7 strains were isolated from 5 (0.4%) animals in 4 flocks, and non-O157 STEC strains were isolated from 462 (36%) lambs in 63 flocks. A total of 384 ovine STEC strains were characterized in this study. PCR showed that 213 (55%) strains carried the stx(1) gene, 10 (3%) possessed the stx(2) gene, and 161 (42%) carried both the stx(1) and the stx(2) genes. Enterohemolysin (ehxA) and intimin (eae) virulence genes were detected in 106 (28%) and 23 (6%) of the STEC strains, respectively. The STEC strains belonged to 35 O serogroups and 64 O:H serotypes (including 18 new serotypes). However, 72% were of 1 of the following 12 serotypes: O5:H-, O6:H10, O91:H-, O117:H-, O128:H-, O128:H2, O136:H20, O146:H8, O146:H21, O156:H-, O166:H28, and ONT:H21 (where NT is nontypeable). Although the 384 STEC strains belonged to 95 different seropathotypes (associations between serotypes and virulence genes), 49% of strains belonged to only 11. O91:H- stx(1) stx(2) (54 strains) was the most common seropathotype, followed by O128:H- stx(1) stx(2) (33 strains) and O6:H10 stx(1) (25 strains). Three strains of serotypes O26:H11, O156:H11, and OX177:H11 had intimin type beta1; 5 strains of serotype O157:H7 possessed intimin type gamma1; and 15 strains of serotypes O49:H-, O52:H12, O156:H- (12 strains), and O156:H25 had the new intimin, intimin type zeta. The majority (82%) of ovine STEC strains belonged to serotypes previously found to be associated with human STEC strains, and 51% belonged to serotypes associated with STEC strains isolated from patients with hemolytic-uremic syndrome. Thus, this study confirms that healthy sheep are a major reservoir of STEC strains pathogenic for humans.

Adhesins, Bacterial↗
PubMed2003

[Familial focal and segmentary hyalinosis].

Focal segmental glomerulosclerosis represents a finding in several renal disorders, characterized by proteinuria and sometimes by arterial hypertension and progressive decline in renal function. There are primary (idiopathic and familial) and secundary forms. In the last 20 years several familial cases has been reported, with a great genetic heterogeneity (dominant and recessive forms) and with multiple associations with particular MHC class-I and class-II gene loci, being Al, DR3 o DR7 the most frequently reported. We described three members of same family with focal segmental hyalinosis that shared the HLA haplotype A31 B61 DR13. This association has not been described previously. We highlight that genetic and acquired factors (obesity, hypertension...) could have importance in the development of progressive renal failure in these patients.

Adult↗
PubMed2002

Depuration and anatomical distribution of the amnesic shellfish poisoning (ASP) toxin domoic acid in the king scallop Pecten maximus.

The depuration kinetics of the domoic acid of four body fractions (digestive gland, adductor muscle, gonad+kidney and gills+mantle) of the scallop Pecten maximus was studied over 295 days. The scallops, which had acquired the toxins during a Pseudo-nitzschia australis episode that took place the week before the beginning of the experiment, were maintained in tanks with running seawater. All the body fractions, except the adductor muscle, decreased their domoic acid burden throughout the experiment. The amount of toxin in the muscle dropped sharply at the start of the experiment but increased again at the end, to levels that were higher than the initial ones. Several dynamic models of depuration kinetics, which included the depuration of each fraction (excluding the adductor muscle) and the transfers between them, were constructed, implemented and fitted to the data to obtain their parameters. The estimated depuration rates were very low, both considering and not considering the transfer of toxin between organs or the effect of weight loss. There were strong differences in the domoic acid burden of the body fractions studied but not between their depuration rates. No net transfer from the digestive gland, the tissue with highest domoic acid concentration, to the other fractions was found, as the inclusion of these processes in the models produced only a marginally better fit to the data. The depuration of domoic acid was slightly, but significantly, affected by biomass. Weight loss induced domoic acid loss, suggesting that part of the depuration may be produced by the direct loss of bivalve cells. The concentration or dilution effect, due to decreases or increases in biomass, documented for other species and toxins, has little importance in Pecten maximus.

Animals↗
PubMed2002

Serobiotypes and virulence genes of Escherichia coli strains isolated from diarrheic and healthy rabbits in Brazil.

A total of 178 Escherichia coli isolates from diarrheic and healthy rabbits in the São Paulo State (Brazil) were serobiotyped and investigated by PCR for the presence of virulence genes. Among the 90 (50.6%) isolates which possessed the eae gene, 74 were from diarrheic animals and all but one encoded intimin beta. Sixty five (72.2%) of the eae+ isolates had insertion of the locus of enterocyte effacement locus in the pheU locus, 11 (12.2%) in the selC and 14 (15.6%) did not insert in either of these loci. All isolates were negative for genes of the E. coli enterotoxins, Stx1, Stx2, CNF1, CNF2 and EHEC hemolysin. The O132:H2 serotype was dominant, being present in 63 isolates (70%) of the 90 eae+ isolates, and 57 of the 63 isolates of this serotype belonged to biotype 30. PCR detected the gene for AF/R2 fimbriae in 75 (83.3%) of the 90 eae+ isolates. Adherence to HeLa cells was best detected following 6h incubation and a positive fluorescence actin staining (FAS) test was given by 52 isolates. These data show that isolates of E. coli associated with diarrhea in rabbits in Brazil possess the genotype and phenotype typically associated with rabbit enteropathogenic E. coli (EPEC). We conclude that EPEC that possess the eae gene are a common cause of diarrhea in Brazilian rabbit farms and that the pathogenic eae+ AF/R2+ isolates of O132:H2:B30 serobiotype are especially predominant.

Animals↗
PubMed2002

Examination of Escherichia coli from poultry for selected adhesin genes important in disease caused by mammalian pathogenic E. coli.

A collection of 1601 extraintestinal and intestinal Escherichia coli isolated from chickens, turkeys and ducks, in Belgium, France and Spain, was hybridised with gene probes specific for fimbrial and afimbrial adhesins (F17, F18, S , Bfp, Afa, Cs31A, Intimin , Aida-1) of intestinal, urinary and invasive E. coli of mammals and with a probe specific for the P (Pap/Prs) fimbrial adhesin of urinary and invasive E. coli of mammals and birds. Three hundred and eighty-three strains (23.9%) were P-positive, 76 strains (4.8%) were Afa-positive, 75 strains (4.7%) were F17-positive, 67 strains (4.2%) were S-positive, 23 (1.4%) were Intimin-positive, and all were F18-, Cs31A-, Aida1- and Bfp-negative. The 75 F17-positive strains harboured different major subunit A-encoding gene variants, but the f17Ac variant was the most frequent (52 strains, 69.3%) and seven strains (9.3%) were not typeable. The f17G gene variant coding for the GII adhesin was the most frequent (56 strains, 75.0%), whereas the f17GI gene variant was present in four strains (5%) and 15 strains (20.0%) were not typeable. All Afa-positive strains harboured the afa-8 variant. The 23 Intimin-positive E. coli tested positive for the beta-variant (16 strains; 69.6%) or for the gamma-variant (seven strains; 30.4%) of the eae gene. Chicken and turkey E. coli were more frequently probe-positive (43.6 and 43.1%, respectively) than duck E. coli (31.5%) and extraintestinal E. coli were also more frequently probe-positive (48.4%) than intestinal strains (18.5%). Different combinations of probe positive hybridisation results were observed in 72 of the 540 probe-positive E. coli (13.3%). The most frequent combinations were between AfaE-8 and F17 probes (47 strains; 8.7%) and between P and S probes (13 strains; 2.4%). Although f17- and afa-8-related DNA sequences can be plasmid-located in mammalian E. coli, they were not in avian E. coli. Besides the P fimbrial adhesins, F17 and S fimbrial and Afa-VIII and Intimin afimbrial adhesins may thus represent colonisation factors of avian pathogenic E. coli.

Adhesins, Bacterial↗
PubMed2002

[Submental abscess by Lactobacillus acidophilus/jensenii].

The different species of Lactobacillus genus are bacteria of a low pathogenicity. They are found in the gastrointestinal tract, the female genitourinary tract, and also as part of the anaerobic flora in the mouth. Due to this low pathogenicity, they are generally related with infections together with other with more virulent microorganisms, or in immunocompromised patients. In our case, Lactobacillus appears alone as an etiological agent in an immunocompetent patient with a submental abscess.

Abscess↗
PubMed2002

New large solar photocatalytic plant: set-up and preliminary results.

A European industrial consortium called SOLARDETOX has been created as the result of an EC-DGXII BRITE-EURAM-III-financed project on solar photocatalytic detoxification of water. The project objective was to develop a simple, efficient and commercially competitive water-treatment technology, based on compound parabolic collectors (CPCs) solar collectors and TiO2 photocatalysis, to make possible easy design and installation. The design, set-up and preliminary results of the main project deliverable, the first European industrial solar detoxification treatment plant, is presented. This plant has been designed for the batch treatment of 2 m3 of water with a 100 m2 collector-aperture area and aqueous aerated suspensions of polycrystalline TiO2 irradiated by sunlight. Fully automatic control reduces operation and maintenance manpower. Plant behaviour has been compared (using dichloroacetic acid and cyanide at 50 mg l(-1) initial concentration as model compounds) with the small CPC pilot plants installed at the Plataforma Solar de Almería several years ago. The first results with high-content cyanide (1 g l(-1)) waste water are presented and plant treatment capacity is calculated.

Automation↗
PubMed2002

Diploid sperm and the origin of triploidy.

Trisomy 16, the 45,X monosomy and triploidy are the more frequent chromosome anomalies in spontaneous abortions. Earlier estimations, based on frequencies of diandric triploidy at conception, resulted in a good correlation with the frequencies of diploid sperm in infertile males (up to 1.9%). Recent data have shown that most diandric triploids originate by dispermy, although 8.3% of them are produced by diploid sperm resulting from meiotic errors. Using these data, the estimated frequency of diploid sperm is still in good correlation with the percentage above. Furthermore, analysis of male pronuclei (PN) in 3PN zygotes produced by ICSI with sperm from oligo-, crypto- and azoospermic males revealed that 33.3% of them were diploid, while none of the PN produced by normozoospermic males by IVF was. The estimated frequency of diploid sperm in these infertile males is also in good correlation with the previous figures. The data suggest that most diandric triploids are produced by normozoospermic males by dispermy, while most diandric triploids produced by oligozoospermic males would result from fertilization by unreduced, diploid sperm.

Abortion, Spontaneous↗
PubMed2002

Risk assessment and segregation analysis in a pericentric inversion inv6p23q25 carrier using FISH on decondensed sperm nuclei.

Fluorescent in situ hybridization (FISH) in decondensed sperm nuclei has been used to determine the percentage of normal/balanced or unbalanced spermatozoa produced by an inv(6)(p23q25) carrier, and the possible interchromosomal effect (ICE) of the reorganized chromosomes on other chromosome pairs. A dual color FISH with specific subtelomeric probes for the 6p and 6q regions was performed to determine the segregation pattern of the inverted chromosome. ICE on chromosomes 18, X and Y was assessed using a triple color FISH assay. In the segregation analysis 10,049 spermatozoa were analyzed, and only 45.7% of them were normal/balanced. The high number of unbalanced gametes in our carrier could be the consequence of the large size of the inverted segment. This situation could facilitate the formation of an inversion loop, where formation of an odd number of chiasmata (usually one) result in the production of 50% normal and 50% unbalanced sperm. Furthermore, an increase in the disomy rate for chromosome 6 was also observed. In the screening for ICE, 10,007 spermatozoa were analyzed. The disomy rate for the sex chromosomes and chromosome 18 were not significantly different from those found in our controls, suggesting no evidence of interchromosomal effects in this patient. The use of FISH in decondensed sperm nuclei has proved once more to be an accurate approach to determine the chromosome anomalies in sperm and could help to better establish a reproductive prognosis.

Adult↗
PubMed2001

Chromosomal abnormalities in sperm.

The use of FISH (fluorescent in situ hybridization) in decondensed sperm nuclei has allowed, during the last decade, to indirectly study the chromosome constitution of human spermatozoa. Studies in control populations have been used to set up the basal level of aneuploidy for all human chromosomes and, based on conservative estimates, the percentage of chromosomally abnormal sperm in the general population could be considered to be at least 6.7%. In carriers of sex chromosome numerical anomalies and in severe oligozoospermic males (both frequent candidates for intracytoplasmic sperm injection), in structural chromosome carriers (enrolled in preimplantation genetic diagnosis programs) and in couples with recurrent miscarriage, sperm chromosome analyses by FISH could help to better establish a reproductive prognosis.

Cell Nucleus↗
PubMed2001

Human immunodeficiency virus 1 envelope glycoprotein complex-induced apoptosis involves mammalian target of rapamycin/FKBP12-rapamycin-associated protein-mediated p53 phosphorylation.

Syncytia arising from the fusion of cells expressing a lymphotropic human immunodeficiency virus (HIV)-1-encoded envelope glycoprotein complex (Env) gene with cells expressing the CD4/CXCR4 complex undergo apoptosis through a mitochondrion-controlled pathway initiated by the upregulation of Bax. In syncytial apoptosis, phosphorylation of p53 on serine 15 (p53S15) precedes Bax upregulation, the apoptosis-linked conformational change of Bax, the insertion of Bax in mitochondrial membranes, subsequent release of cytochrome c, caspase activation, and apoptosis. p53S15 phosphorylation also occurs in vivo, in HIV-1(+) donors, where it can be detected in preapoptotic and apoptotic syncytia in lymph nodes, as well as in peripheral blood mononuclear cells, correlating with viral load. Syncytium-induced p53S15 phosphorylation is mediated by the upregulation/activation of mammalian target of rapamycin (mTOR), also called FKBP12-rapamycin-associated protein (FRAP), which coimmunoprecipitates with p53. Inhibition of mTOR/FRAP by rapamycin reduces apoptosis in several paradigms of syncytium-dependent death, including in primary CD4(+) lymphoblasts infected by HIV-1. Concomitantly, rapamycin inhibits p53S15 phosphorylation, mitochondrial translocation of Bax, loss of the mitochondrial transmembrane potential, mitochondrial release of cytochrome c, and nuclear chromatin condensation. Transfection with dominant negative p53 has a similar antiapoptotic action as rapamycin, upstream of the Bax upregulation/translocation. In summary, we demonstrate that phosphorylation of p53S15 by mTOR/FRAP plays a critical role in syncytial apoptosis driven by HIV-1 Env.

Animals↗
PubMed2001

Stromal-cell-derived factor 1 prevents the emergence of the syncytium-inducing phenotype of HIV-1 in vivo.

In a correlative study, the mean plasma level of the chemokine stromal-cell-derived factor 1 (SDF-1) was lower in subjects with syncytium-inducing (SI) than in subjects with non-syncytium-inducing (NSI) HIV isolates, regardless of the CD4 cell count or when compared with HIV-negative individuals. Individuals with high SDF-1 had an 81% probability of having an NSI virus phenotype compared with individuals with lower SDF-1. Increased expression of SDF-1 may help explain why the more pathogenic SI HIV-1 variants do not appear in some individuals.

Chemokine CXCL12↗
PubMed2001

CD4(+) and CD8(+) T cell death during human immunodeficiency virus infection in vitro.

We have evaluated the death of CD4(+) and CD8(+) T cells during in vitro human immunodeficiency virus (HIV) infection of peripheral blood mononuclear cells (PBMC) and tonsilar tissue. Acute infections with several X4 and R5 HIV isolates induced a decrease in cell viability that was higher in infections with X4 viruses and correlated with an increased rate of CD4(+) T-cell death. In CD4(+) T cells, the primary X4 isolate AOM induced higher levels of death than the laboratory X4 isolates IIIB and NL4-3 or the R5 isolates BaL and MDM. An effect on CD8(+) T-cell viability was exclusively observed in infections by X4 viruses, including the NL4-3 strain, in both PBMC and tonsilar tissue. This effect was dependent on the env gene of the infecting isolate and required productive HIV replication in CD4(+) but not in CD8(+) T cells. Our results suggest that X4 and R5 HIV isolates depleted CD4(+) T cells to a different extent and that CD8(+) T-cell viability may also be affected by mechanisms other than those acting in CD4(+) T cells.

CD4-Positive T-Lymphocytes↗