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Biomedical subjects

C Navarro

Publications and source records attributed to C Navarro.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of risk patterns in carcinoma and melanoma of the skin in men: a multi-centre case-case-control study.

We directly compared risk factors between 214 histologically confirmed melanomas (CMM), 215 basal-cell carcinomas (BCC) and 139 squamous-cell carcinomas (SCC) in a multiple case-case-control study with 349 controls from patients without dermatological disease admitted to the same hospitals. Subjects with fair hair had a significant risk increase for all types of tumours at a comparable level (OR(adj) for blonde hair: CMM 2.3; SCC 2.4; BCC 2.3). The effect of pale eyes was significant and similar for CMM and BCC (OR(adj) 2.6). Intermittent sun exposure measured in hours spent at beach during holidays was significant for both CMM (OR(adj) 2.6 for more than 7000 lifelong hours) and BCC (OR(adj) 2.1 for more than 7000 lifelong hours), while SCC exhibited a significant risk increase for chronic exposure to sunlight measured in hours of outdoor work (OR(adj) 2.2 for more than 6000 lifelong hours). In the case-case comparison using a multinomial logistic regression model, we found a statistically significant risk difference for pale eyes, and number of naevi in the CMM group, compared to other skin cancers. For intermittent sun exposure, there was a significant risk difference of BCC when compared to the risk of SCC. Factors influencing risk of SCC are different, with chronic exposure to sun playing a major role in causing this type of carcinoma.

Adult↗
PubMed2006

Abiotic ecotypes in south-central Spanish rivers: reference conditions and pollution.

Physico-chemical water quality in five of Spain's main rivers was assessed during the years 2001-2003. A previous physiographical river typology was carried out by applying System B of the Water Framework Directive (2000/60/CE) which distinguished four main river ecotypes: calcareous headwaters, siliceous rivers, plain rivers, and large rivers. The physiographical classification into river ecotypes also corresponded to distinct hydrochemical types. Reference values of ammonium, nitrate and phosphate fitted for local river ecotypes surpassed only slightly the natural and background levels established by the European Environmental Agency (EEA, 2003). Half of the sampled sites were above the limits established as reference conditions. Additionally, concentrations of ammonium, nitrite, nitrate, and phosphate increased when more percentage of land was dedicated to agriculture and less to forest land.

Animals↗
PubMed2006

Validity of self reported diagnoses of cancer in a major Spanish prospective cohort study.

INTRODUCTION: This study aims to assess the validity of self reported diagnoses of cancer by persons recruited for the Spanish EPIC (European prospective investigation into cancer and nutrition) cohort study and to identify variables associated with correctly reporting a diagnosis of cancer. METHODS: 41 440 members of EPIC were asked at the time of recruitment whether they had been diagnosed with cancer and the year of diagnosis and site. The process of validating self reported diagnoses of cancer included comparison of the cohort database with the data from the population based cancer registries. Cancer diagnostic validity tests were calculated. The association between a correct report and certain sociodemographic, tumour related, or health related variables were analysed by logistic regression. RESULTS: The overall sensitivity of self reported diagnoses of cancer is low (57.5%; 95% CI: 51.9 to 63.0), the highest values being shown by persons with a higher level of education or with a family history of cancer and the lowest values by smokers. Breast and thyroid cancers are those with the highest diagnostic validity and uterus, bladder, and colon-rectum those with the lowest. In both sexes the variables showing a significant association with a correct report of cancer are: higher education level, number of previous pathologies, invasive tumour, and, in women, a history of gynaecological surgery. CONCLUSIONS: The overall sensitivity of self reported diagnoses of cancer is comparatively low and it is not recommended in epidemiological studies for identifying tumours. However, self reported diagnoses might be highly valid for certain tumour sites, malignant behaviour, and average to high levels of education.

Adult↗
PubMed2006

Dose reduction of intraoral dental radiography in Spain.

OBJECTIVES: To assess the influence of new European Union (EU) legislation on radiation doses in intraoral dental radiography in Spain. METHODS: A total of 10 109 official reports from Spanish dental offices covering the period 1996-2003 were analysed. RESULTS: The results point to a dose reduction of 19% in 7 years, with a mean dose of 3.11 mGy being administered in 2003. The third quartile value in 2002 was 4.8 mGy. Taking the EU recommended dose of 4 mGy as standard, 73.3% (2002) and 77.3% (2003) of installations are in compliance with the EU recommendations in Spain. However, there has been no further reduction in the last 3 years. The results showed that Ultraspeed dental X-ray film was used by 77.6% of the dentists in 1996-1997 and 82.3 in 2003. There was infrequent use of E-speed films (0.6%) and F-speed films (9.6%) in 2003. Statistical analysis pointed to significant differences between the doses administered and the type of processing used, the lowest exposures being measured in digital systems, which used significantly lower doses than both manual and automatic development, and when conventional radiographic films were used. CONCLUSION: The introduction of new legislation has resulted in a gradual reduction in the dose administered in intraoral dental radiology in Spain.

Analysis of Variance↗
PubMed2005

Autosomal dominant congenital fibre type disproportion: a clinicopathological and imaging study of a large family.

Congenital fibre type disproportion (CFTD) is considered a non-progressive or slowly progressive muscle disease with relative smallness of type 1 fibres on pathological examination. Although generally benign, CFTD has a variable natural course and severe progression has been observed in some patients. The pathogenesis of the disorder is unknown and many authors consider CFTD a syndrome with multiple aetiologies rather than a separate clinical entity. A positive family history has been reported in about 40% of cases, but the inheritance pattern is not clear. Both autosomal recessive and dominant modes of inheritance have been suggested. The present paper describes a large, multigenerational kindred that has an inherited myopathy fulfilling the histological criteria of CFTD, with autosomal dominant transmission and high penetrance. The clinical picture, remarkably similar in all affected family members, started in early infancy with mild limb muscle weakness. There was slow progression of symptoms into adulthood, with moderate to severe, mainly proximal, muscle weakness without loss of ambulation. Muscle biopsy from two affected individuals demonstrated predominance of small type 1 muscle fibres without other significant findings. Nerve conduction studies were normal and needle electromyography showed a myopathic pattern. MRI examination performed on three patients from successive generations showed involvement of proximal limb and paraspinal muscles. The clinical and pathological homogeneity in the present family, together with the lack of additional histological abnormalities after decades of disease progression in two affected individuals, supports this being a distinct myopathy with fibre type disproportion. Whether the disease in this family can be regarded as a form of the congenital myopathy known as CFTD or rather a unique condition sharing histological features with CFTD needs further investigation. This is, to our knowledge, the largest kindred with muscle fibre type disproportion reported to date. Our data confirm autosomal dominant inheritance, and this is the first MRI document of this disorder.

Adult↗
PubMed2005

Genetic resource impacts of habitat loss and degradation; reconciling empirical evidence and predicted theory for neotropical trees.

The theoretical impacts of anthropogenic habitat degradation on genetic resources have been well articulated. Here we use a simulation approach to assess the magnitude of expected genetic change, and review 31 studies of 23 neotropical tree species to assess whether empirical case studies conform to theory. Major differences in the sensitivity of measures to detect the genetic health of degraded populations were obvious. Most studies employing genetic diversity (nine out of 13) found no significant consequences, yet most that assessed progeny inbreeding (six out of eight), reproductive output (seven out of 10) and fitness (all six) highlighted significant impacts. These observations are in line with theory, where inbreeding is observed immediately following impact, but genetic diversity is lost slowly over subsequent generations, which for trees may take decades. Studies also highlight the ecological, not just genetic, consequences of habitat degradation that can cause reduced seed set and progeny fitness. Unexpectedly, two studies examining pollen flow using paternity analysis highlight an extensive network of gene flow at smaller spatial scales (less than 10 km). Gene flow can thus mitigate against loss of genetic diversity and assist in long-term population viability, even in degraded landscapes. Unfortunately, the surveyed studies were too few and heterogeneous to examine concepts of population size thresholds and genetic resilience in relation to life history. Future suggested research priorities include undertaking integrated studies on a range of species in the same landscapes; better documentation of the extent and duration of impact; and most importantly, combining neutral marker, pollination dynamics, ecological consequences, and progeny fitness assessment within single studies.

Computer Simulation↗
PubMed2005

Monitoring genetic diversity in tropical trees with multilocus dominant markers.

Since no universal codominant markers are currently available, dominant genetic markers, such as amplified fragment length polymorphism (AFLP), are valuable tools for assessing genetic diversity in tropical trees. However, the measurement of genetic diversity (H) with dominant markers depends on the frequency of null homozygotes (Q) and the fixation index (F) of populations. While Q can be estimated for AFLP loci, F is less accessible. Through a modelling approach, we show that the monolocus estimation of genetic diversity is strongly dependent on the value of F, but that the multilocus diversity estimate is surprisingly robust to variations in F. The robustness of the estimate is due to a mechanistic effect of compensation between negative and positive biases of H by different AFLP loci exhibiting contrasting frequency profiles of Q. The robustness was tested across contrasting theoretical frequency profiles of Q and verified for 10 neotropical species. Practical recommendations for the implementation of this analytical method are given for genetic surveys in tropical trees, where such markers are widely applied.

Genes, Dominant↗
PubMed2004

Adult onset thalamocerebellar degeneration in dogs associated to neuronal storage of ceroid lipopigment.

Late onset of hereditary cerebellar cortical abiotrophy has been described in a large variety of canine breeds. In some reported conditions, the cerebellar lesion is combined with degeneration of other systems. Here we describe a new hereditary cerebellar cortical degeneration in eight adult American Staffordshire and Pit Bull Terriers. The neuronal degeneration in these animals not only affects Purkinje cells of the cerebellum but also certain thalamic nuclei. In addition, nerve cell loss appears to be associated with a lysosomal storage disease, which is restricted to the affected cell populations. The stored material was histologically and ultrastructurally identified as fluorescent lipopigment. Since animals were euthanized at various stages of the disease, it could be shown that lysosomal storage preceded neuronal loss. Selective involvement of restricted neuronal populations is highly unusual in ceroid lipofuscinoses. It remains to be determined if the present neurodegenerative disease is caused by a primary or secondary neuronal ceroid lipofuscinosis.

Age Factors↗
PubMed2004

Determinants of patient delay among tuberculosis cases in Spain.

BACKGROUND: Patient delay was investigated in a cohort of TB patients identified from May 1996 until April 1997 in 13 Autonomous Regions in Spain. The study covered almost 67% of the total Spanish population. METHODS: Data were collected from clinical records. Using unconditional logistic regression with two different cut-off points to define 'patient delay' (the median and 75th percentile), the association between patient delay and different factors was estimated. RESULTS: A total of 7,037 cases were included. Median and 75th percentile delays were 22 and 57 days respectively. Factors associated with patient delay greater than the median (p<0.05) were: non-respiratory symptoms of TB and age over 14 years, although the effect of age was not linear. Furthermore, an interaction was observed between intravenous drug user (IDU) and HIV status, in that, whereas patient delay was greater in IDUs than in non-IDUs among cases whose HIV status was either negative or unknown, among HIV-positive patients no such IDU-related differences were in evidence. Factors associated with extreme patient delay (greater than the 75th percentile) were essentially the same, but the above-described interaction disappeared, with IDU status showing no direct effect. In addition, likelihood of extreme patient delay increased in the case of alcoholism and female gender and decreased in the case of chronic renal failure, corticoid treatment, prison inmates and residents of old age homes. CONCLUSION: Although there is a universally enjoyed right to health care in Spain, some groups of TB patients could nevertheless be experiencing problems in seeking medical attention.

Adolescent↗
PubMed2004

[Myopathology. New concept. New laboratory].

The introduction of molecular genetics in medicine, specifically in the field of neuromuscular pathology, has created a drastic change in the diagnostic approach used for neuromuscular disorders. Diagnosis of muscle biopsy is based on important aspects such as morphology and histochemistry, but nowadays immunohistochemistry and Western blot analysis of certain proteins is of utmost importance for a correct diagnosis in a large number of neuromuscular disorders and is crucial to direct the genetic study, which is also necessary. To date, more than 30 muscular dystrophy types have been genetically characterized, and the protein product is known in most of them as well as its structural location in the muscle fiber and its relation with other muscle proteins and the extracellular matrix. With the diagnostic specificity conferred by the absence of expression by a specific protein or a mutation of a specific gene, we have learned that similar clinical phenotype may occur in different diseases, such as Duchenne muscular dystrophy and gamma-sarcoglycanopathy, but also that mutations in the same gene may cause different clinical phenotypes, as occurs in Miyoshi distal myopathy and limb girdle muscular dystrophy 2B, both caused by mutations in the dysferlin gene. Herein we describe the recommendable diagnostic methodology and strategy to be employed in the study of the large group of the < >, especially focused on the autosomal recessive dystrophies, taking the study of dystrophinopathies as an example.

Chromosomes, Human, Pair 12↗
PubMed2004

Beta-sarcoglycanopathy (LGMD 2E) in a Spanish family.

Out of 10 autosomal recessive limb-girdle muscular dystrophies reported, 4 are caused by mutations in the genes encoding for sarcoglycans (alpha-, beta-, gamma- and delta-SG). Beta-sarcoglycanopathy (limb-girdle muscular dystrophy 2E) is a genetically heterogeneous disorder which usually presents a severe progressive clinical course. A complete immunohistochemical evaluation of the sarcoglycan complex should be carried out to direct the mutation analysis approach. The present report concerns a Spanish family with a genetically confirmed beta-sarcoglycanopathy. The patient, a 16-year-old female, offspring of a consanguineous marriage, developed a severe limb-girdle muscular dystrophy with a Duchenne-like phenotype. Muscle biopsy showed dystrophic changes and complete absence of the four sarcoglycans. Genetic analysis demonstrated homozygosis for the M100K missense mutation in exon 3, encoding for the proximal extracellular domain. The parents and one sister were found to be carriers. Missense mutations affecting this domain result in the instability of the entire sarcoglycan complex and lead to severe phenotypes as seen in non-sense mutations.

Adolescent↗
PubMed2003

An increased expression of nucleolin is associated with a physiological nucleolar segregation.

Nucleolar segregation is the most striking cellular phenotypic feature of cold-acclimatized carp and depicts the cyclical reprogramming that the physiology of the fish undergoes between summer and winter, where a clear differential expression of some nucleolar related genes occurs. We characterized carp nucleolin, a nucleolar protein involved in multiple steps of ribosome biogenesis, and evaluated its expression upon fish acclimatization. We show that the carp cDNA deduced amino acid sequence exhibits the same tripartite structural organization found in other species. Nevertheless, we observed that nucleolin mRNA expression was strongly induced in the cold-adapted carp as was the nuclear protein content, assessed by immunocytochemistry in liver sections. The physiological up-regulation of nucleolin in the cold-acclimatized carp, where rRNA transcription and processing are depressed concomitantly with the nucleolus segregation, is consistent with the notion that nucleolin plays a fundamental role in repressing rRNA synthesis.

Acclimatization↗
PubMed2003

Outcome results of two levels of intervention in low-income women with depressive symptoms.

The effectiveness of 2 levels of intervention in reducing depressive symptoms in women was evaluated using a comparison design for a group condition (6 2-hr weekly sessions) and a minimum individual condition (20-min individual orientation plus psychoeducational material) with pretreatment, posttreatment, and follow-up assessments (93 in the group and 42 in the individual condition). A multivariate analysis of variance showed significant differences, in the expected direction, within the groups but not between conditions. Further comparisons showed a significant reduction from pretreatment to posttreatment and from pretreatment to follow-up assessment. Similar results were found for criteria-related variables (somatic and anxiety symptoms); an increase in self-esteem was observed as well.

Adult↗
PubMed2003

Fine-scale genetic structure and gene flow within Costa Rican populations of mahogany (Swietenia macrophylla).

Fine-scale structure of genetic diversity and gene flow were analysed in three Costa Rican populations of mahogany, Swietenia macrophylla. Population differentiation estimated using AFLPs and SSRs was low (38.3 and 24%) and only slightly higher than previous estimates for Central American populations based on RAPD variation (20%). Significant fine-scale spatial structure was found in all of the surveyed mahogany populations and is probably strongly influenced by the limited seed dispersal range of the species. Furthermore, a survey of progeny arrays from selected mother trees in two of the plots indicated that most pollinations involved proximate trees. These data indicate that very little gene flow, via either pollen or seed, is occurring between blocks of mahogany within a continuous or disturbed forest landscape. Thus, once diversity is removed from a forest population of mahogany, these data suggest that recovery would be difficult via seed or pollen dispersal, and provides an explanation for mahogany's apparent susceptibility to the pressures of logging. Evidence is reviewed from other studies of gene flow and seedling regeneration to discuss alternative extraction strategies that may maintain diversity or allow recovery of genetic resources.

Biological Evolution↗
PubMed2003

Chloroplast DNA phylogeography reveals colonization history of a Neotropical tree, Cedrela odorata L., in Mesoamerica.

Spanish Cedar (Cedrela odorata L.) is a globally important timber species which has been severely exploited in Mesoamerica for over 200 years. Using polymerase chain reaction-restriction fragment length polymorphisms, its chloroplast (cp) DNA phylogeography was studied in Mesoamerica with samples from 29 populations in six countries. Five haplotypes were characterized, phylogenetically grouped into three lineages (Northern, Central and Southern). Spatial analysis of ordered genetic distance confirmed deviation from a pattern of isolation by distance. The geographically proximate Northern and Central cpDNA lineages were genetically the most differentiated, with the Southern lineage appearing between them on a minimum spanning tree. However, populations possessing Southern lineage haplotypes occupy distinct moist habitats, in contrast to populations possessing Northern and Central lineage haplotypes which occupy drier and more seasonal habitats. Given the known colonization of the proto-Mesoamerican peninsula by South American flora and fauna prior to the formation of the Isthmus of Panama, it seems most likely that the observed population structure in C. odorata results from repeated colonization of Mesoamerica from South American source populations. Such a model would imply an ancient, pre-Isthmian colonization of a dry-adapted type (possessing the Northern lineage or a prototype thereof), with a secondary colonization via the land bridge. Following this, a more recent (possibly post-Pleistocene) expansion of moist-adapted types possessing the Southern lineage from the south fits the known vegetation history of the region.

Cedrela↗
PubMed2003

Two levels of intervention in low-income women with depressive symptoms: compliance and programme assessment.

AIMS: This study reports on the evaluation of a brief group intervention for women of limited means with depressive symptoms. METHOD: A comparison design was used with pre-, post- and four-month follow-up assessments for 93 women in the group intervention condition who were given six two-hour sessions of psycho-educational intervention, and 42 women in a minimum individual condition who received a 20-minute explanation in addition to the educational material, which yielded the following results. RESULTS: Both conditions were effective in motivating participants to engage in self-help activities (making time for themselves every week, using writing as a means of sorting out problems, talking to someone about their problems and carrying out the reflection and cognitive behavioural exercises) and to seek further professional help when necessary. The intervention condition was more positively evaluated since participants regarded it as having a greater influence on their life and problems. Influence was related to better understanding and coping with problems, mood improvement, changes in the way they thought about things, knowing themselves better and being more accepting of themselves. CONCLUSIONS: The results suggest that both interventions tackle important issues related to depression in women but further data are needed for a better understanding of this relationship.

Adult↗