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C López

Publications and source records attributed to C López.

At least 37 records · Page 2Linked to original sources
PubMed2004

The complete nucleotide sequence of a Spanish isolate of Citrus psorosis virus: comparative analysis with other ophioviruses.

The complete genomic sequence (11278 nt) of Citrus psorosis virus (CPsV), isolate P-121 from Spain, was determined and compared with those from isolate CPV-4 and from other ophioviruses. The three RNAs of P-121 had similar size and identical organization as those of CPV-4. The 24K and the RdRp proteins were potentially encoded in the viral complementary (vc) strand of RNA 1, the 54K protein potentially encoded in vcRNA 2 and the coat protein encoded in vcRNA 3. These four proteins from P-121 and CPV-4 had 87, 92, 93 and 94% amino acid identity, respectively, but only 22, 38, 25 and 33% identity with their homologous proteins from Mirafiori lettuce big vein virus (MLBVV), the only other ophiovirus completely sequenced. Biological and genetic differences between CPsV and MLBVV (and the other ophioviruses), would support their future allocation in different genera within a tentative family Ophioviridae.

Base Sequence↗
PubMed2004

Impact of temperature and air pollution on the mortality of children in Madrid.

This work analyzes the impact of temperature and air pollution on infant mortality in Madrid. Daily values of mortality of children younger than 10 years, maximum and minimum temperatures, and air pollutants were considered for an 11-year period. In winter, mortality was mostly associated with very low temperatures and high total suspended particles (TSP) concentrations, whereas summer mortality depended crucially on the occurrence of high TSP and nitrogen oxides concentrations. In winter, the temperature effect increases dramatically for daily maximum temperature values lower than 6degreesC. This pattern is rather different from the one obtained for older age groups in the same location, which show the well-known V relationship between temperature and mortality. The association with TSP shows 2 linear branches without threshold and a strong increase in mortality for concentrations more than 100 microg/m3.

Air Pollutants↗
PubMed2003

Polymorphism of a specific region in gene p23 of Citrus tristeza virus allows discrimination between mild and severe isolates.

The pathogenicity determinants of Citrus tristeza virus (CTV) are presently unknown, although transgenic Mexican limes over-expressing CTV p23, an RNA-binding protein involved in regulating the asymmetrical accumulation of viral RNA strands, display typical CTV symptoms. Here we compared the predominant sequence variants of gene p23 from 18 CTV isolates of different geographic origin and pathogenicity characteristics. Phylogenetic analysis of these sequences revealed three groups of isolates: i) mild, inducing only symptoms in lime and/or decline of citrus species grafted on sour orange rootstock, ii) severe, causing additionally stem pitting on sweet orange and/or grapefruit, and iii) an atypical group of isolates inciting variable symptoms. The sequences of the isolates located at the periphery of each group were recombinants. Pairwise comparisons of the predicted amino acid sequences showed that residues at positions 78-80 were characteristic of each group of isolates. Group-specific primers based on these differences allowed RT-PCR detection of each sequence type in dsRNA-rich preparations from infected tissues. While mild isolates contained only the sequence characteristic of this group, most severe isolates contained the sequences characteristic of their group, and additionally, sequences characteristic of the mild and/or the atypical groups, suggesting that the severe phenotype is associated with the presence of the severe and/or the atypical sequence types. This association can be exploited for quick detection of potentially damaging sequence variants and for monitoring cross protection.

Amino Acid Sequence↗
PubMed2003

Prevalence of natural ovine fasciolosis shown by demonstrating the presence of serum circulating antigens.

The prevalence of fasciolosis in sheep (Galicia, Northwest Spain) kept under field conditions was determined by using a sandwich-enzyme-linked immunosorbent assay (sELISA). Serum Fasciola hepatica circulating antigens were captured by means of a rabbit polyclonal IgG antibody to F. hepatica excretory/secretory products. Results were compared to those obtained by faecal sedimentation and an indirect ELISA (iELISA) and excretory/secretory antigens. Prevalences were 39.1% by sELISA, 30.4% by faecal sedimentation and 56% by iELISA; 83.3% of the sheep were positive to any one of the three tests. We observed that 59.5% of the sheep examined had active fasciolosis, 29.1% (117) had antigenaemia, 20.4% (82) passed eggs, and 40 (10%) were positive to both probes. We conclude that there is a high prevalence of fasciolosis in sheep from the studied region, and that the combination of sELISA and coprological sedimentation is extremely helpful for demonstrating current fasciolosis, so its application can be strongly recommended for epidemiological surveys.

Animals↗
PubMed2003

Serum antibodies to Dicrocoelium dendriticum in sheep from Sardinia (Italy).

An indirect enzyme-linked immunosorbent assay (ELISA) with Dicrocoelium dendriticum excretory/secretory antigens was used to evaluate the presence of serum antibodies against the trematode in 738 sheep randomly chosen in Sardinia (Italy). Coprological sedimentation was used to discover egg-output. Seropositivity was detected in 86.2% tested sheep, whereas faecal prevalence was 6.7%; all that were faecal-positive also were ELISA-positive.

Animals↗
PubMed2003

Neoplastic transformation and tumour-like lesions in Paget's disease of bone: a pictorial review.

The development of a sarcoma is the most serious complication of Paget's disease of bone. Although its incidence is <1% of those with the underlying disease, it is important to recognise the imaging features of these tumours as Paget's disease of bone is relatively common in the ageing population in certain parts of the world. The purpose of this pictorial review is to present the imaging features of Paget's sarcoma based on one orthopaedic oncology centres experience in 49 patients; however, not all masses or destructive lesions arising in association with Paget's disease are sarcomas and not all the tumours are malignant. This review also includes other malignancies which may arise in pagetic bone as well as tumour-like manifestations of Paget's disease.

Adult↗
PubMed2003

Diagnosis of parasitic zoonoses by immunoenzymatic assays--analysis of cross-reactivity among the excretory/secretory antigens of Fasciola hepatica, Toxocara canis, and Ascaris suum.

Several parasitic infections such fasciolosis, toxocariosis or ascariosis are important zoonoses. During the infection with Fasciola hepatica, Toxocara canis and Ascaris suum, an important intraorganic phase in their hosts takes place, releasing antigens responsible for a humoral immune response, which enables the diagnosis of that parasitosis. A study to identify the existence of cross-reactivity among the excretory/ secretory antigens of F. hepatica, T. canis and A. suum was developed. One group of Sprague-Dawley rats was infected with 20 metacercariae of F. hepatica and another group remained uninfected as control. By means of an Indirect-ELISA, the rat humoral immune response (IgG and IgM) against the excretory/secretory antigens of F. hepatica was analysed and measured for cross reactivity with T. canis and A. suum. IgM cross-reaction was mainly observed in the first 10 weeks post-infection. IgG cross-reaction was observed throughout the study, and was maximal at the 2-3 weeks and 3-6 weeks post-infection, which corresponds to the intraorganic migratory phase of these parasites. The western-blot showed that the rat IgG recognised three proteins of 190, 160 and 33 kDa in the antigens from F. hepatica, T. canis and A. suum. The existence of cross-reactivity among these antigens seems to demonstrate also the presence of structural similarities, such as tegumental proteins. These results should be consider when immunoassay probes are used in the diagnosis of parasitic infections.

Animals↗
PubMed2003

[Exoftalmos and palpebral ptosis in the immunocompromised patient].

The mucormycosis is an opportunistic mycosis which has a high rate of global mortality with a bad prognosis. The present clinical case shows a patient attended in the Intensive Care Unit because of a breathing insufficiency secondary to a pneumonia. Among his antecedents there is a larynx carcinoma totally remittent after chemo- and radiotherapy. He develops an infrapalpebral injury which spreads rapidly in a bilateral way acquiring a necrotic look that it did not have initially. Having that evolution, it is implemented a treatment with liposomal amphotericin B and granulocyte colony-stimulating factors after an injury biopsy, whose posterior cultive shows growing of Mucor. This kind of pathology must be initially suspected in all the patients with a neoplasia and its treatment must be early and agressive. At the moment the diagnosis is suspected there is a great tissue destruction and for that reason the patients usually die in spite of the instauration of aggressive therapies

Blepharoptosis↗
PubMed2003

[Campylobacteriosis in a low-income community in Buenos Aires, Argentina].

The authors describe the problem of campylobacteriosis in a low-income community located in southern Buenos Aires. Homes in the area were classified according to their total number of inhabitants, the number of children and animals living in the house and the amount of poultry meat consumed. Samples were taken from all the different types of homes that had been identified in order to isolate, identify and type Campylobacter sp., using the modified Skirrow technique, bio-chemical tests and the Lior technique respectively. The prevalences found were 16.96% in dogs, 20% in cats and 40% in poultry. The pathogens isolated were Campylobacter jejuni type II in 94.44% of the cases and Campylobacter upsaliensis in 5.55% of the cases. In poultry meat, 92.85% of the samples were positive (23.07% for type I and 76.92% for type II). The incidence of diarrhoea in children caused by C. jejuni was 0.4/1000 children/month (type I in all cases). A high prevalence of C. jejuni type II was detected in pets and in poultry meat. The source of infection in children may have been poultry meat.

Animals↗
PubMed2002

Enzymatic membrane reactors for biodegradation of recalcitrant compounds. Application to dye decolourisation.

Membrane bioreactors are being increasingly used in enzymatic catalysed transformations. However, the application of enzymatic-based treatment systems in the environmental field is rather unusual. The aim of this paper is to overview the application of enzymatic membrane reactors to wastewater treatment, more specifically to dye decolourisation. Firstly, the basic aspects such as different configurations of enzymatic reactors, advantages and disadvantages associated to their utilisation are revised as well as the application of this technology to wastewater treatment. Secondly, dye decolourisation by white-rot fungi and their oxidative enzymes are discussed, presenting an overall view from for in vivo and in vitro systems. Finally, dye decolourisation by manganese peroxidase in an enzymatic membrane reactor in continuous operation is presented.

Azo Compounds↗
PubMed2002

[HIV prevalence among homosexual and bisexual men in Spain, 1992-2000].

BACKGROUND: Our purpose was to describe the time trend in HIV seroprevalence among homo/ bisexual men. SUBJECTS AND METHOD: We analyzed 9,383 homo/ bisexual men who had a first voluntary test for HIV in 10 Spanish clinics from 1992 to 2000. RESULTS: HIV prevalence decreased from 20.3% in 1992 to 8.4% in 2000. In the multivariate analysis this decline appeared independently associated with the testing year and the birth cohort. CONCLUSIONS: New generations of voluntarily tested homo/bisexual men are less infected by HIV, but it is yet necessary to intensify the prevention programs.

Adolescent↗
PubMed2002

Effects of extremely hot days on people older than 65 years in Seville (Spain) from 1986 to 1997.

The effects of heat waves on the population have been described by different authors and a consistent relationship between mortality and temperature has been found, especially in elderly subjects. The present paper studies this effect in Seville, a city in the south of Spain, known for its climate of mild winters and hot summers, when the temperature frequently exceeds 40 degrees C. This study focuses on the summer months (June to September) for the years from 1986 to 1997. The relationships between total daily mortality and different specific causes for persons older than 65 and 75 years, of each gender, were analysed. Maximum daily temperature and relative humidity at 7.00 a.m. were introduced as environmental variables. The possible confounding effect of different atmospheric pollutants, particularly ozone, were considered. The methodology employed was time series analysis using Box-Jenkins models with exogenous variables. On the basis of dispersion diagrams, we defined extremely hot days as those when the maximum daily temperature surpassed 41 degrees C. The ARIMA model clearly shows the relationship between temperature and mortality. Mortality for all causes increased up to 51% above the average in the group over 75 years for each degree Celsius beyond 41 degrees C. The effect is more noticeable for cardiovascular than for respiratory diseases, and more in women than in men. Among the atmospheric pollutants, a relation was found between mortality and concentrations of ozone, especially for men older than 75.

Aged↗
PubMed2002

A recombinant envelope protein from Dengue virus purified by IMAC is bioequivalent with its immune-affinity chromatography purified counterpart.

Semi-purified DEN-4 envelope protein, obtained in Pichia pastoris, was capable of generating neutralising and protecting antibodies after immunisation in mice. Here we compared two purification processes of this recombinant protein using two chromatographic steps: immune-affinity chromatography and immobilised metal ion adsorption chromatography (IMAC). The protein purified by both methods produced functional antibodies reflected by titres of haemagglutination inhibition and neutralisation. IMAC could be used as an alternative for high scale purification.

Animals↗
PubMed2002

Heat waves in Madrid 1986-1997: effects on the health of the elderly.

OBJECTIVE: The objective of this paper is to analyse and quantify the effects exerted on summer mortality by extremes of heat, particularly among persons aged 65-74 and 75 years and over, groups in which mortality is higher. METHODS: The study included the period from 1 January 1986 to 31 December 1997, for all people aged over 65 years resident in Madrid, based on mortality due to all causes except accidents (ICD-9 codes 1-799), and circulatory (390-459) and respiratory (460-487) causes. Meteorological variables analysed were: daily maximum temperature, daily minimum temperature and relative humidity. To control the effect of air pollution on mortality we considered the daily mean values of sulphur dioxide (SO2), total suspended particulate (TSP), nitric oxides (NOx), nitrogen dioxide (NO2) and tropospheric ozone (O3). Univariate and multivariate ARIMA models were used. Box-Jenkins pre-whitening was performed. RESULTS: The results yielded by this study indicate a mortality increase up to 28.4% for every degree the temperature rises above 36.5 degrees C, with particular effect in women over the age of 75 years and circulatory-cause mortality. The first heat wave that leads to the greatest effects on mortality, due to the higher number of susceptible people and the duration of the heat wave, show an exponential growth in mortality. Furthermore, low relative humidity enhances the effects of high temperature, linking dryness to air pollutants, ozone in particular. CONCLUSIONS: Since a warmer climate is predicted in the future, the incidence of heat wave should increase, and more comprehensive measures, both medical and social, should be adopted to prevent the effects of extreme heat on the population, particularly the elderly.

Aged↗
PubMed2002

Multidrug resistance in the protozoan parasite Entamoeba histolytica.

In this review we discuss the mechanisms and molecules involved in the multidrug resistance (MDR) of the protozoan parasite Entamoeba histolytica. Drug resistant mutants exhibited the main characteristics presented by the MDR mammalian cells. They showed cross-resistance to several unrelated drugs that is reverted by calcium channel blockers. MDR phenotype in E. histolytica is regulated at a transcriptional level by the EhPgp1 gene, which is constitutively expressed and by the EhPgp5 gene, whose expression is induced in the presence of the drug. Transcription factors participate in the expression regulation of these genes. After over transcription, the EhPgp genes are amplified, cooperating to produce the MDR phenotype. Post-transcriptional mechanisms such as mRNA stability seem to be involved in this phenomenon. As for other mdr gene products, the EhPGP5 protein functions as a chloride current inductor or as a regulator of cellular regulatory volume decrease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Influence of age and breed on natural bovine fasciolosis in an endemic area (Galicia, NW Spain).

An analysis was undertaken of the effect of breed and age on bovine fasciolosis using antibody and antigen detection ELISAs. A total of 84.3% of the 1284 serum samples examined had positive antibody values and 20.4% exhibited antigenaemia. The seroprevalence of antibodies in crossbred cattle was higher than that in autochthonous Rubia Gallega, Friesian or Brown Swiss cows. The highest percentage antigenaemia occurred in the Brown Swiss cattle, but the breed differences were not statistically significant. Cattle aged 3-5 years had the highest antibody and circulating antigen prevalence and the age differences were significant. It was concluded that the apparent influence of breed was probably closely associated with the husbandry system. The autochthonous Rubia Gallega may be better adapted to fasciolosis as its percentage of antigenaemia was the lowest.

Aging↗
PubMed2002

Gastric gross and microscopic lesions caused by the UNAM-97 variant strain of infectious bronchitis virus after the eighth passage in specific pathogen-free chicken embryos.

Herein we report a description of gross and microscopic lesions found in specific pathogen-free chicken embryos caused by UNAM-97 infectious bronchitis virus (IBV) variant strain after the eighth passage. Embryos were divided into three groups and were inoculated in the chorioallantoic sac with 0.2 mL of UNAM-97, Mass 41 IBV (positive control), or sterile PBS (negative control). Forty-eight hours later the allatoic fluid was taken and used to start a cycle of eight passages through 9-d-old embryos. Seven days after the last passage, embryos were harvested and macroscopic lesions in all organs were recorded. Proventriculus and gizzard samples were obtained from all embryos and routinely processed for microscopic and ultrastructural examinations. The UNAM-97 IBV variant strain caused two macroscopic lesions uncommon for Mexican strains: thin-walled proventriculus and gizzard, as well as urate accumulation within an extra-embryonic peritoneal sac, leaving the body through the umbilical duct and accompanied by the yolk sac. At microscopic level, two relevant findings were observed to be produced by this variant. In the proventriculus, there was a decrease in the gland papillary branching, while the gizzard showed a significant reduction in mucosa thickness and tubular-to-proliferative-cell ratio, as well as an absence of hyaline secretion in the lumen. Electrodense material scattered in proventricular and gizzard cells was observed, with a structure consistent with that of coronaviruses. These pathological chicken embryo findings have not been reported as being caused by other IBV strains in Mexico.

Animals↗