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Biomedical subjects

A M García

Publications and source records attributed to A M García.

At least 19 recordsLinked to original sources
PubMed2006

Maternal and paternal occupational exposure to agricultural work and the risk of anencephaly.

AIMS: To evaluate the association between parental occupational exposure to agricultural work and the risk of anencephaly in three Mexican states. METHODS: A paired case control study (1:1) was done based on records of the Epidemiological Surveillance System of Neural Tube Defects in Mexico; 151 cases of anencephaly of more than 20 weeks' gestation were selected between March 2000 and February 2001. Controls were selected from the same maternity services as those of the cases and were born alive without congenital malformations. Information was obtained from both parents by means of a general questionnaire, a food frequency questionnaire, and a specific questionnaire on occupational exposure to pesticides. Exposures were analysed with emphasis on the three months before and one month after the last menstruation periods (acute risk period (ARP)), as well as exposure prior to the above mentioned period (non-acute risk period (NARP)). RESULTS: The children of mothers who worked in agriculture in the ARP had a greater risk of anencephaly (OR = 4.57, 95% CI 1.05 to 19.96). The risk of fathers having a child with anencephaly was greater in those who applied pesticides irrespective of whether it was done in the ARP or the NARP (OR = 2.50, 95% CI 0.73 to 8.64; and OR = 2.03, 95% CI 0.58 to 7.08, respectively). CONCLUSIONS: These results support the hypothesis of the effect of maternal exposure to agricultural work on anencephaly and suggest that exposure of the father to pesticides in the periconceptional period or prior to this can also increase the risk of having an anencephalic child.

Adolescent↗
PubMed2006

Histology and histochemistry of the pharyngeal cavity and oesophagus of the silverside Odontesthes bonariensis (Cuvier and Valenciennes).

The histology of the pharyngeal cavity and oesophagus of the freshwater 'silverside'Odontesthes bonariensis (Cuvier and Valenciennes) and the characteristics of their mucous cells were investigated. The histological characterization of its digestive wall revealed that the mucosa is thrown with longitudinal folds. The epithelium covering the folds was stratified with abundant mucous cells and gustative corpuscles, which are lacking in the oesophagus. The muscularis mucosa was absent. The submucosa presented the compactum stratum. The muscularis was organized in longitudinal and circular layers of muscular striated fibres. The serosa with a flat epithelium was located only in the oesophagus. Using histochemical procedures including methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cells contents of the pharyngeal cavity and those of the oesophagus. The mucous cells showed a weak periodic acid-Schiff (PAS) positive reaction in their content. The reactions for the differential analysis of sialic acids from GPs are feeble for periodic acid-Schiff at low temperature and low pH (PA*S) and KOH/PA*S and strong for periodic acid/borohydride/KOH/PAS (PA/Bh/KOH/PAS) and KOH/PA*/Bh/PAS revealing the scarce presence of C7 or C9 substituted and non-substituted sialic acids and the abundance of C7, C8 substituted sialic acids, O-acyl sugars and neutral sugars respectively. The results suggest that the pharyngeal cavity with the gustative corpuscles would induce the gastric secretion whereas the oesophagus is mainly involved in the transport of the food bolus to the stomach with the aid of abundant secretion of mucus. GPs secreted on the surface of the mucous cells, likely related to environmental conditions, would be involved in the lubrication, protection against abrasion and inhibition of microorganism proliferation.

Animals↗
PubMed2006

[Pure alexia secondary to progressive multifocal leukoencephalopathy as first manifestation of HIV infection].

INTRODUCTION: Pure alexia, or alexia without agraphia, is usually caused by disconnection between the gyrus angularis and visual areas of both hemispheres. Cerebrovascular disease is the most frequent cause of this syndrome. CLINICAL CASE: We report the first case of a patient with pure alexia secondary to progressive multifocal leukoencephalopathy (PML) as the first manifestation of Human Immunodeficiency Virus (HIV) infection. Polymerase chain reaction in cerebrospinal fluid was positive for JC virus. Despite favorable immunological and virological response to highly active antiretroviral therapy, neurological symptoms and demyelinating lesions progressed during the first months, and right homonyous hemianopsia, acalculia, and color anomia were noted. In magnetic resonance imaging (MRI) demyelinating lesions involved white matter of both occipital lobes, with left predominance, forceps major and splenium of the corpus callosum, together with white matter of the left temporal lobe and both hippocampal regions. During the following months, coinciding cidofovir treatment, the patient had partial clinical improvement, but neurological deficits persisted. The size of MRI lesions significantly improved. CONCLUSIONS: PML is frequently the first manifestation of AIDS (acquired immunodeficiency syndrome). It should be considered as a possible diagnosis of pure alexia.

Alexia, Pure↗
PubMed2005

Composition and antibacterial activity of essential oil of Lantana achyranthifolia Desf. (Verbenaceae).

The essential oil of the aerial parts of Lantana achyranthifolia Desf. (Verbenaceae) was examined by GC and GC-MS. Eighteen constituents were identified. Carvacrol, 1,8-cineole, isocaryophyllene, beta-bisabolene and alpha-bisabolol were found to be the major components. The oil exhibited antibacterial activity against fourteen Gram-positive and Gram-negative bacteria.

Anti-Bacterial Agents↗
PubMed2005

Ultrastructure and histochemical study of glycoconjugates in the gills of the white croaker (Micropogonias furnieri).

The ultrastructure of the primary and secondary lamellae of gills was investigated in a marine teleost, the white croaker. The following cells were identified and briefly described: pavement cells, mucous cells, mitochondria-rich cells and rodlet cells. These cell types are present throughout the length of the lamellae. They are studied by means of a series of carbohydrate histochemical methods, including lectin procedures. Neutral sugars and substituted sialic acid were detected by means of periodic acid-borohydride reduction-saponification-periodic acid Schiff reaction (PA/Bh/KOH/PAS), saponification-selective periodic acid Schiff reaction (KOH/PA*S) and saponification-selective periodic acid-borohydride reduction-periodic acid Schiff reaction (KOH/PA*/Bh/PAS) histochemical techniques. A battery of seven lectins was used to study binding on tissue sections at the light microscopic level to characterize glycoconjugates in gills. The reaction to Canavalia ensiformis agglutinin (Con-A), Triticum vulgaris agglutinin (WGA), and Ricinus cummunis agglutinin-1 (RCA-1) was weak in pavement cells; unlike Con-A, the reaction to WGA and RCA-1 was more intense in mucous cells. Arachis hypogaea agglutinin (PNA) lectin showed a strong reaction in mucous cells. Ulex europaens agglutinin-1 (UEA-1) lectin was negative in all cell types. The lectin pattern was similar for both primary and secondary lamellae, except for PNA reaction, which was weak in the pavement cells of the secondary lamella and negative in the pavement cells of the primary lamella.

Animals↗
PubMed2004

Paternal exposure to agricultural pesticides and cause specific fetal death.

AIMS: To study the association between fetal death and paternal agricultural occupation in areas and time periods with different levels of use of agricultural pesticides. METHODS: A total of 1 473 146 stillbirths and births occurring in Spain between 1995 and 1999 were analysed. RESULTS: The offspring of agricultural workers had the highest risk of fetal death from congenital anomalies in the southern and eastern area (where pesticide use is greatest) and the lowest risk in the rest of Spain. In both areas the offspring of agricultural workers had a similar excess risk of fetal death from the remaining causes of death. The relative risk of fetal death from congenital anomalies in infants conceived between April and September (the months of greater use of pesticides) in the southern and eastern area was 0.90 in manual workers and 1.62 in agricultural workers, compared to non-manual workers; in individuals who were conceived during the rest of the year, the relative risk was 0.87 and 0.85, respectively. In both periods the offspring of agricultural workers had an excess risk of fetal death from the remaining causes of death. CONCLUSIONS: Paternal agricultural work in the areas where pesticides are massively used increases the risk of fetal death from congenital anomalies. The risk is also increased for fetuses conceived during the time periods of maximum use of pesticides The higher risk of fetal death from the remaining causes of death in the offspring of agricultural workers seems unrelated to pesticide exposure.

Abnormalities, Drug-Induced↗
PubMed2003

Inhibition of growth and induction of apoptosis in human breast cancer by transfection of gef gene.

The gef gene has cell-killing functions in Escherichia coli. To evaluate the feasibility of using this gene as a new strategy for cancer therapy, we transfected it in MCF-7 cells derived from breast cancer (MCF-7TG). The gef gene was cloned in a pMAMneo vector under the control of a mouse mammary tumour virus promoter, inducible by dexamethasone (Dex), and was transfected with liposomes. After selection and induction, expression of the gef gene was confirmed by reverse transcription-polymerase chain reactions (RT-PCR) and Western blot. Cell viability was determined with a haemocytometre and the sulphorodamine B colorimetric assay, and the cell cycle was studied by propidium iodide (PI) staining. Annexin V-FITC and PI assays were used to evaluate apoptosis, which was confirmed by electron microscopy. In comparison with MCF-7 parental cells and MCF-7 cells transfected with an empty vector, MCF-7TG cells induced with Dex showed a significant decrease in proliferation rate, which was associated with evidence of apoptosis. Morphological findings confirmed apoptosis and showed a typical pattern of mitochondrial dilation. Furthermore, the cell cycle was characterised by premature progression from G(1) to S phase and G(2) delay. Our results show that the gef gene was able to decrease proliferation in a breast cancer cell line, and induce apoptosis. These findings suggest that the gef gene is a potential candidate for tumour therapy.

Animals↗
PubMed2003

Morphological and histochemical characterization of the mucosa of the digestive tract in Engraulis anchoita.

The histomorphological aspects as well as the histochemical content and distribution of glycoproteins (GPs) in the mucosa of the digestive tract of the anchovy Engraulis anchoita were studied. The buccopharyngeal cavity is lined by a squamous stratified epithelium with mucous superficial cells; the oesophagus shows two zones, cranial with a squamous stratified epithelium with mucous superficial cells and caudal with a columnar secretory epithelium. Finally, the stomach presents both the cranial and pyloric portion lined with a simple columnar epithelium. Tubular branched glands, formed by a single type of glandular cell, located along the stomach, are more numerous in the cranial portion. The GPs were identified with (1) oxidizable vicinal diols; (2) sialic acids and some of their chain variants, C7 or C9; (3) sialic acid residues with O-acyl substitution at C7 or C8; (4) carboxyl groups and (5) sulphate groups. Histochemical tests showed that the buccopharyngeal cavity presented the largest amount of the different types of mucosubstances. Epithelial secretory cells were found in the oesophagus, which synthesized a large quantity of sialosulphoglycoproteins likely to be related to a protective role. The surface epithelium of the stomach synthesizes and secretes acid and neutral GPs, probably related to the movement of fluids and to the absorption of easily digested substrates, respectively. Although great differences exist between different species, in E. anchoita as in other fish species, the wall of the digestive tract is composed of the four layers classically described for vertebrates. The GPs secreted by the epithelial cells are suggested to be important for the protection and inhibition of microorganisms. In addition, they are involved in enzymatic digestion of food, absorptive functions and lubrication of the alimentary tract.

Animals↗
PubMed2003

A glossary for research in occupational health.

This glossary includes a selection of terms pertaining to the field of research in occupational health. The glossary is mostly addressed to readers not familiarised with the more specific terms used in the study and protection of workers' health. The terms have been ordered according to their logical connections, so the glossary can be read from beginning to end giving the reader an overview on occupational health research main focuses, methods, and applications.

Humans↗
PubMed2001

Ameloblastic fibrosarcoma of the mandible: report of two cases and review of the literature.

Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumour. To date, 60 well-documented cases have been published in the English-language literature. Two additional cases located in the posterior region of the mandible are reported. The relevant clinicopathological features of these cases, as well as those previously reported are discussed. Approximately two-thirds of AFS are malignant tumors de novo, with an average age of the affected patients being 22.9 years. This age is lower than the one observed in AFS developing from a pre-existent benign lesion (mean 33 years). Although regional and distant metastases are very infrequent, AFS is a locally aggressive lesion, with 23 (37%) of the reported cases having at least one recurrence; 12 patients (19.3%) died of the disease. Wide surgical excision with long-term follow-up remains the treatment of choice for this neoplasm.

Adult↗
PubMed2001

Mucous cells in micropogonias furnieri gills: histochemistry and ultrastructure.

The characteristics of the mucous cells located in the gills of the fish Micropogonias furnieri were investigated. Using histochemical procedures that included methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cell contents of the primary and secondary lamellae. The GPs were identified with (a) oxidizable vecinal diols; (b) sialic acids and some of their chain variants, C7 or C9; (c) carboxyl groups and (d) sulphate groups. The electron microscope showed large mucous globules of different electro densities from mucous cells located deep in the epithelium between the other epithelial cells; the release of mucus by exocytosis was observed. GPs secreted on the surface of the mucous cells was suggested to be important for the lubrication, protection and inhibition of microorganisms. It is possibility that GPs could have similar roles in Micropogonias furnieri gills.

Animals↗
PubMed2000

DNA ploidy status and proliferative activity as markers of malignant potential in Barrett's esophagus: flow cytometric study using routinely paraffin-embedded tissue.

Regular endoscopic surveillance is recommended for patients with Barrett's esophagus to detect dysplasia and to diagnose carcinoma while it is in an early and possibly treatable stage. However, there are numerous unknown aspects regarding the natural history of dysplasia in this disease, and there is still a need for more accurate markers of risk of a malignant change. The aim of this study was to investigate the usefulness of DNA flow cytometry in Barrett's esophagus to define subgroups of patients showing similar histologic findings but with a different malignancy potential. Routinely formalin-fixed and paraffin-embedded tissues of 43 patients with Barrett's esophagus were processed for flow cytometric measurements (ploidy, proliferative index) and the results were compared with the histologic evolution observed in these patients. Only in the group of patients with "indefinite" dysplasia did we find statistically significant differences between the samples from patients with and without progression to more severe lesions (mean proliferative index of stable patients: 5.2% versus 8.3% in patients with progression, p = 0.001, Student's t-test). The presence in the flow cytometric analysis of a DNA aneuploid cell line is closely related to the presence of severe histologic alterations (i.e., high-grade dysplasia: p < 0.001, Fisher's exact test). Our results suggest that this procedure is at least capable of distinguishing between a real, although incipient, neoplastic process and morphologic changes of a reactive or reparative type. The increment in the tissue proliferative index could be an indicator of an early genomic instability which, with time, will develop into lesions with a more altered DNA content: aneuploidy.

Adenocarcinoma↗
PubMed2000

Association between M467T and 114 C-->A variants within the SLC3A1 gene and some phenotypical traits in cystinuria patients from Spain.

Cystinuria is an inherited metabolic disease characterized by an abnormal urinary excretion of cystine and dibasic amino acids. Formation of renal calculi, recurrent infections and renal failure are the main complications of this disease. The SLC3A1 gene, which codes for a dibasic amino acid transporter protein, is involved in the pathogenesis of cystinuria. We investigated the possible association between molecular variants (M467T, E483X, T216 M and 114 C-->A) within the SLC3A1 gene and some phenotypical traits in a Spanish area. The study population consisted of 45 cystinuria patients, 42 cystinuria relatives and 81 healthy control subjects. Only the M467T mutation was found in chromosomes of cystinuria patients and relatives. However, the 114 C-->A polymorphism was detected in cystinuria patients, in relatives and in control subjects but with different prevalences. Moreover, a statistically significant association between this polymorphism and urinary amino acid levels was found in cystinuria patients (P<0.05). Subjects with the C/C genotype showed significantly higher urinary levels of cystine, arginine and their sum as compared with carriers of the A allele (P<0.05). When multiple linear regression analysis was performed in cystinuria patients, the 114 C-->A polymorphism remained significantly associated (P=0.047) with cystine levels even after controlling for age, gender and the M467T mutation. Furthermore, we also found a statistically significant interaction term (P=0.028) between M467T and 114 C-->A in determining urinary cystine levels. According to our results, the 114 C-->A polymorphism might be a marker of a functional variant in the SLC3A1 gene or in other genes related to urinary amino acid excretion in cystinuria patients.

Adult↗
PubMed2000

Childhood cancer survival in Cuba.

Reports dealing with childhood cancer population-based survival have not yet been published in Cuba. A survival study including cases reported to the National Cancer Registry in the period 1988-1989 have been accomplished in the National Cancer Registry of Cuba. A comprehensive view of its results in childhood cancer is intended to be shown in this paper. All sites childhood cancer cases aged below 15 years (400) and reported in this period were included derived from a total of 578 incident cases. Vital status of cases was checked-up to December of 1994 by a mixed follow-up. Survival analysis was achieved by the life-table method using the SPSS for Windows software. Relative survival rates were not included because no differences were appreciated with the observed ones. Cases between 0-4 years and females account for the highest frequencies. Leukaemia accounts for 27% of the cases, followed by lymphomas and tumours of the central nervous system. Lymphoid and non-lymphoid acute leukaemia had 41 and 9% 5-year survival rate respectively being the latter comparable with Bangalore, India (10%). For lymphomas, Hodgkin's disease present better prognosis compared with non-Hodgkin lymphoma with 73 and 35% 5-year survival rates, respectively. Figures are comparable to the corresponding to Bangalore, India (72 and 33%, respectively). For time trends survival distribution were compared by period of diagnosis (1982/1988-1989). In all cases differences resulted statistically non-significant with lower rates for 1988-1989 except for lymphomas. International reports show increasing time trends for childhood cancer. Nevertheless, these results may serve as a milestone for future comparisons, corresponding with the creation of the National Program for Childhood Cancer Control and future studies will confirm the success of its measures.

Adolescent↗
PubMed2000

Experts' assessment of probability and level of pesticide exposure in agricultural workers.

The occupational history of the parents of 261 infants with congenital malformations and 261 matched controls was collected. During the relevant time period before the birth of their child, 183 parents were involved in agricultural activities, 49% of them having directly applied pesticides. Two experts assessed the probability and the level of exposure to each quoted pesticide (582 observations) by using 4-point scales. Interrater agreement was estimated. Kappa-weighted values for probability and level of exposure were, respectively, kappa = 0.36 and kappa = 0.39. In the analysis of some categories of exposure (non-applicators, herbicides) very low interrater agreement was observed. In epidemiological studies, detailed assessment of pesticide exposure (product-by-product) is needed to investigate the effects of pesticides on health. But the application of experts' judgment in this area needs more research in assessing the validity of this approach.

Abnormalities, Drug-Induced↗