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Grobas S, Méndez J, Lopez BC, De BC, Mateos GG. Effect of vitamin E and A supplementation on egg yolk alpha-tocopherol concentration. Poult Sci 2002; 81:376-81. [PMID: 11902415 DOI: 10.1093/ps/81.3.376] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The objective of this study was to asses the effect of dietary dl-alpha-tocopheryl acetate (alpha-TAC) and vitamin A supplementation on egg yolk alpha-tocopherol (alpha-T) concentration. A total of 96 ISA brown hens (a brown-egg laying hen), 32 wk of age, was used. Eight concentrations of alpha-TAC (0, 20, 40, 80, 160, 320, 640, and 1,280 IU/kg diet) were included in a corn-soybean meal-based diet containing 4,000 IU of vitamin A/kg diet. Production parameters were not affected by dietary treatment. Interhen variation in yolk alpha-T concentration increased at higher dietary intakes. Logarithmic transformation stabilized variance and showed the existence of a linear relationship between dietary alpha-TAC supplementation level and alpha-T egg yolk concentration (P < 0.001). As the dietary concentration of alpha-TAC rose, efficiency of uptake of alpha-T from feed to yolk decreased linearly (P < 0.001). A parallel experiment was carried out in which four additional groups of hens were fed diets containing four levels of dietary alpha-TAC (0, 40, 160, and 640 IU/kg) and 40,000 IU vitamin A/kg diet. A significantly lower egg yolk alpha-T concentration was found in hens fed diets including the highest level of vitamin A supplementation (P < 0.001). No interaction of dietary alpha-TAC and vitamin A concentrations was observed on egg yolk alpha-T concentration. No effect of dietary treatment was observed on yolk oxidation and other egg quality characteristics.
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Insua A, Freire R, Ríos J, Méndez J. The 5S rDNA of mussels Mytilus galloprovincialis and M. edulis: sequence variation and chromosomal location. Chromosome Res 2002; 9:495-505. [PMID: 11592484 DOI: 10.1023/a:1011636714052] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The 5S ribosomal DNA of the mussels Mytilus galloprovincialis and M. edulis was amplified by PCR using contiguous primers. The most general 5S rDNA amplification pattern consisted of several products in both mussels. Two main PCR products of about 250 bp and 760 bp were cloned and sequenced, revealing two classes of 5S rDNA units. These were characterized as containing an identical coding region of 119 bp but with highly divergent spacers. Clones of each unit type exhibited minimal differences except those of the large unit of M. edulis. The sequences analysed of the two mussels possess the same coding region and only six fixed base changes on the spacers. FISH, carried out with specific probes, consistently showed hybridization signals on the largest metacentric pair (two differentiated sites) and with variable frequency on two other metacentric pairs (one site on each pair). Differences in the 5S rDNA distribution between both mussels were not found. In M. edulis, chromosomes carrying 18S-28S rDNA were also identified by FISH. These correspond to two submetacentric-subtelocentric pairs, as was previously reported in M. galloprovincialis, demonstrating that the two rDNA multigene families are located on different chromosome pairs in these mussels.
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Manuel Ruiz-Giardín J, Noguerado A, Pizarro A, Méndez J, La Hulla F, Fernández M, Hernández F, San Martín J, Hernández I, Álvarez J, Salvanes F. Estudio comparativo de los factores de riesgo y pronósticos de mortalidad en las bacteriemias-fungemias polimicrobianas de un hospital universitario: evolución en 10 años. Enferm Infecc Microbiol Clin 2002. [DOI: 10.1016/s0213-005x(02)72839-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Iglesias P, Bayón C, Méndez J, Gancedo PG, Grande C, Diez JJ. Serum insulin-like growth factor type 1, insulin-like growth factor-binding protein-1, and insulin-like growth factor-binding protein-3 concentrations in patients with thyroid dysfunction. Thyroid 2001; 11:1043-8. [PMID: 11762714 DOI: 10.1089/105072501753271734] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Thyroid hormones play a role in the regulation of insulin-like growth factor type 1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) expression, and both IGF-1 and IGFBPs have been shown to be related to the function and growth of the thyroid. Our aim was to evaluate serum concentrations of IGF-1, IGFBP-1, and IGFBP-3 in patients with thyroid dysfunction before and after normalization of thyroid function. The study was performed in 86 patients with thyroid dysfunction (43 hyperthyroid and 43 hypothyroid patients) and 17 euthyroid subjects. Serum growth hormone (GH), insulin, IGF-1, IGFBP-1, and IGFBP-3 were measured in all patients before and after normalizing serum thyroid hormone concentrations. Hyperthyroid patients showed IGF-1 (198.8 +/- 17.0 microg/L) and IGFBP-3 levels (4.2 +/- 0.2 mg/L) similar to those found in the control group (217.9 +/- 20.3 microg/L and 4.2 +/- 0.3 mg/L, respectively). After therapy these levels significantly decreased to 156.6 + 11.1 microg/L (p < 0.01) and 3.3 +/- 0.1 mg/L (p < 0.001), respectively. IGFBP-1 concentrations were clearly higher than those found in controls (22.7+/- 2.6 vs. 5.7 +/- 1.5 microg/L, p < 0.001) and exhibited a significant reduction after therapy for thyroid hyperfunction (11.0 +/- 1.7 microg/L, p < 0.001). Patients with hypothyroidism showed serum concentrations of IGF-1 (161.5 +/- 13.1 microg/L, p < 0.05) and IGFBP-3 (3.2 +/- 0.3 microg/L, p < 0.05) significantly lower than those found in healthy volunteers. However, replacement therapy with levothyroxine did not induce any significant modification of these concentrations (152.6 +/- 10.6 microg/L and 3.2 +/- 0.2 mg/L, respectively). Similarly, patients with thyroid hypofunction exhibited raised levels of IGFBP-1 (15.5 +/- 0.9 microg/L, p < 0.05 vs. control group) that were significantly decreased after therapy (8.8 +/- 1.4 microg/L, p < 0.01). The results of the present study show that thyroid status affects GH/IGF axis. Hypothyroidism is associated with significant reductions of IGF-1 and IGFBP-3, and IGFBP-1 is elevated in both hypothyroidism and hyperthyroidism.
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Garcia Páez JM, Jorge-Herrero E, Carrera A, Millán I, Rocha A, Calero P, Cordón A, Salvador J, Sainz N, Méndez J, Castillo-Olivares JL. Chemical treatment and tissue selection: factors that influence the mechanical behaviour of porcine pericardium. Biomaterials 2001; 22:2759-67. [PMID: 11545310 DOI: 10.1016/s0142-9612(01)00019-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Calcification and mechanical failure are the major causes of the loss of cardiac bioprostheses. The chemical treatments used to stabilize the tissue employed are considered to play a fundamental role in the development of these two phenomena, although the problem is multifactorial and the underlying causes are yet to be fully identified. Currently, there is an ongoing search for chemical treatments capable of reducing or eliminating the process of calcification while preserving the mechanoelastic characteristics of the tissue. One of the approaches to this effort is the elimination of the phospholipid component from the biological tissue employed in prosthesis construction. There is evidence that this component may be responsible for the precipitation of calcium salts. The present study compares two delipidating chemical treatments involving chloroform/methanol and sodium dodecyl sulfate (SDS) with the use of glutaraldehyde (GA) alone. For this purpose, porcine pericardial tissue was subjected to tensile strength testing employing a hydraulic simulator. A total of 234 samples were studied 90 treated with GA, 72 treated with chloroform/methanol and 72 treated with SDS. The mean breaking strength was significantly higher in the samples treated with GA (between 43.29 and 63.01 MPa) when compared with those of tissue treated with chloroform/methanol (29.92-42.30 MPa) or with SDS (13.49-19.06 MPa). In a second phase of the study, selection criteria based on morphological and mechanical factors were applied to the pericardial membranes employing a system of paired samples. The mathematical analysis of the findings in one fragment will aid in determining the mechanical behavior of its adjacent twin sample. In conclusion, the anticalcification chemical treatments tested in the experimental model conferred a lesser mechanical resistance than that obtained with GA. On the other hand, the utilization of paired samples was found to be useful in the prediction of the mechanical behavior of porcine pericardial tissue. Nevertheless, in order for our method of selection to be considered the most adequate approach, it will be necessary to validate these findings in dynamic studies involving a real, functional model.
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Vizoso F, Plaza E, Vázquez J, Serra C, Lamelas ML, González LO, Merino AM, Méndez J. Lysozyme expression by breast carcinomas, correlation with clinicopathologic parameters, and prognostic significance. Ann Surg Oncol 2001; 8:667-74. [PMID: 11569783 DOI: 10.1007/s10434-001-0667-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Here we evaluate the expression and prognostic value of lysozyme, a milk protein that is also synthesized by a significant percentage of breast carcinomas, in women with breast cancer. METHODS Lysozyme expression was examined by immunohistochemical methods in a series of 177 breast cancer tissue sections. Staining was quantified by using the HSCORE system, which considers both the intensity and the percentage of cells staining at each intensity. The prognostic value of lysozyme was retrospectively evaluated by multivariate analysis that took into account conventional prognostic factors. RESULTS A total of 126 of 177 carcinomas (69.4%) stained positive for this protein, but there were clear differences among them with regard to the intensity and percentage of stained cells. Lysozyme values were higher in well-differentiated and moderately differentiated tumors than in poorly differentiated tumors (P < .05). Similarly, lysozyme levels were higher in small and node-negative tumors than in large and node-positive tumors (P < .05). Moreover, results indicated that low lysozyme content predicted shorter relapse-free survival and overall survival (P < .005). Separate Cox multivariate analysis in subgroups of patients as defined by node status showed that lysozyme expression was an independent prognostic factor able to predict both relapse-free survival and overall survival in node-negative patients (P < .05). CONCLUSIONS Tumoral expression of lysozyme is associated with lesions of favorable evolution in breast cancer. This milk protein may be a new prognostic factor in patients with breast cancer.
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Jiménez G, Hasegawa M, Rodríguez M, Estrada O, Méndez J, Castillo A, Gonzalez-Mujica F, Motta N, Vásquez J, Romero-Vecchione E. Biological screening of plants of the Venezuelan Amazons. JOURNAL OF ETHNOPHARMACOLOGY 2001; 77:77-83. [PMID: 11483381 DOI: 10.1016/s0378-8741(01)00271-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A total of 21 extracts derived from 17 different plant species collected in Venezuelan Amazons have been tested for the following biological activities: cardiovascular activity, brine shrimp lethality, and inhibitory effects on the hydrolysis of glucose-6-phosphate in intact and disrupted microsomes. Eight extracts diminished rat blood pressure with or without changes in heart rate. The fruit extract of Swartzia leptopetala and the leaf and twig extract of Connarus lambertii resulted in death of experimental animals. The majority of extracts (17 extracts) showed significant toxicity against Artemia salina. Concerning the hydrolysis of glucose-6-phosphate, better inhibitory effects were observed in intact microsomes than in disrupted ones for all the extracts, suggesting that these extracts intervene with variable potency in glucose-6-phosphate transport through the microsomal membrane.
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83
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García Páez JM, Jorge-Herrero E, Carrera A, Millán I, Rocha A, Cordón A, Salvador J, Sainz N, Méndez J, Castillo-Olivares JL. A new method for selecting calf pericardium for use in cardiac bioprostheses on the basis of morphological and mechanical criteria. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2001; 12:665-671. [PMID: 15348235 DOI: 10.1023/a:1011252022303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The durability of existing calf pericardium bioprostheses is limited by phenomena such as mechanical stress and calcification, the factors most frequently implicated in valve failure. Varying the preferred direction of the collagen fibers influences the mechanical behavior of the pericardial membrane. Given this possible variation, a strict control of the selection of the biomaterial employed in the construction of valve leaflets is essential, but a reliable method of selection has yet to be established. This study describes the development of a new system of in vitro selection involving a hydraulic simulator that reproduces the mechanical behavior of pericardial membranes subjected to the stress of continuous flow. By combining morphological criteria such as thickness and homogeneity with those of mechanical behavior, and by selecting paired samples from different parts of the pericardium, we obtained excellent mathematical fits. Linear regression analysis provided the mode of predicting the tensile strength in a given sample when this value had been determined in its twin. The upper zones of calf pericardium, corresponding to either right or left ventricle but at a distance from ligamentous structures, showed the best mean results at rupture (60 MPa) and permitted the most reliable prediction. The expected stress for an elongation of 30% was 1.12 MPa, as was previously observed, with a 95% confidence interval of between 1.11 and 1.14 MPa. These trials, together with the careful selection of the pairs, should help to establish definitive selection criteria.
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84
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Grobas S, Méndez J, Lázaro R, de Blas C, Mateo GG. Influence of source and percentage of fat added to diet on performance and fatty acid composition of egg yolks of two strains of laying hens. Poult Sci 2001; 80:1171-9. [PMID: 11495470 DOI: 10.1093/ps/80.8.1171] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We conducted a trial to study the influence of strain of hen (white vs. brown) and source and percentage of added fat to diet on productive performance and fatty acid (FA) profile of the egg yolk. There were nine dietary treatments: a control diet without added fat and eight diets arranged as a 2 x 4 factorial (5 vs. 10% added tallow, olive, soy, or linseed oil). Each treatment was replicated five times, and the trial lasted 12 wk. White hens produced yolks with more saturated FA (P < 0.001) and less monounsaturated FA (P < 0.001) and polyunsaturated FA (P < 0.05) than brown hens. Fat supplementation improved egg mass output (P < 0.05) and feed efficiency of hens (P < 0.001). Linseed and soy oil diets produced greater egg mass than diets based on tallow or olive oil (59.6, 59.4, 57.9, and 57.1%, respectively; P < 0.001). The proportion of saturated FA in the yolk decreased as the percentage of added fat increased (36.5, 32.3, and 31.0% for diets containing 0, 5, and 10% added fat, respectively; P < 0.001). When the alpha-linolenic acid content of the diets increased from 0 to 0.8%, the arachidonic, docosapentanoic, and docosahexanoic acids in the egg yolk increased. Increases in the alpha-linolenic acid content of the diet over 2.3% did not further augment the concentration of docosapentanoic or docosahexanoic acid of the yolk and, in fact, decreased that of arachidonic acid. Only diets supplemented with linseed oil produced eggs with measurable amounts of eicosapentanoic acid. Diets supplemented with soy oil, with moderate levels of alpha-linolenic acid and high levels of linoleic acid, increased arachidonic and docosahexanoic acids in the egg yolk but not eicosapentanoic acid.
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Laffon B, Lema M, Méndez J. Simultaneous high-performance liquid chromatographic determination of urinary mandelic and phenylglyoxylic acids as indirect evaluation of styrene exposure. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 753:385-93. [PMID: 11334354 DOI: 10.1016/s0378-4347(00)00583-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Styrene is rapidly metabolised to mandelic acid (MA) and phenylglyoxylic acid (PGA), which are excreted in urine. In this work, we have developed a simple, sensitive and specific high-performance liquid chromatographic method with minor sample preparation procedures for the simultaneous determination of MA and PGA in urine of workers exposed to styrene. Moreover, urine samples from workers of two plastic factories were analysed, styrene exposure levels of the workers were estimated and data obtained from the two factories were compared.
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Laffon B, Pásaro E, Méndez J. Genotoxic effects of styrene-7,8-oxide in human white blood cells: comet assay in relation to the induction of sister-chromatid exchanges and micronuclei. Mutat Res 2001; 491:163-72. [PMID: 11287309 DOI: 10.1016/s1383-5718(01)00135-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Styrene is used in the production of plastics, resins and rubber. The highest human exposures to styrene take place by inhalation during the production of fiberglass reinforced plastics. Styrene is metabolized mainly in the liver to styrene-7,8-oxide (SO), its principal in vivo mutagenic metabolite. In this study, human peripheral white blood cells were exposed to several SO concentrations (10-200 microM) in order to evaluate its genotoxic properties by means of comet assay, sister-chromatid exchanges (SCE) and cytokinesis-blocked micronucleus (MN) test, in addition to determine its clastogenic or aneugenic properties by combining MN with fluorescence in situ hybridization (FISH) procedures. Our results show that SO induces DNA damage, SCE and MN in human leukocytes in vitro at concentrations above 50 microM, and that there is a strong relationship between DNA damage, as measured by the comet assay, and cytogenetic damage induced by SO at the doses employed. SO shows preferentially a clastogenic activity and produces a cytostatic effect at high doses, reflected by the significant decrease of the calculated proliferation indices. A good dose-effect relationship is obtained in the three tests performed at the concentration range assayed.
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Araujo R, Muniesa M, Méndez J, Puig A, Queralt N, Lucena F, Jofre J. Optimisation and standardisation of a method for detecting and enumerating bacteriophages infecting Bacteroides fragilis. J Virol Methods 2001; 93:127-36. [PMID: 11311351 DOI: 10.1016/s0166-0934(01)00261-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A method for the detection and enumeration of bacteriophages infecting Bacteroides fragilis has been standardised. The recommended host strain is RYC2056 (ATCC 700786) because of the relatively high counts (10(4)-10(5) PFU/100ml) that it recovers in sewage from very different geographical areas. The addition of 0.25% bile to the culture and assay media and the manipulation of the host strain under strict anaerobic conditions resulted in a significant increase (more than 100%) in the number of phages detected. No other changes in the media and culture conditions resulted in changes in the phage counts detected. However, these increases do not justify changing the culture conditions and media described, taking into consideration that bile renders the media cloudy making it difficult to follow the host growth and that most laboratories do not have the facilities to work under strict anaerobic conditions. Nalidixic acid (100 microg/ml) and kanamycin (100 microg/ml) in the assay medium significantly reduce the background flora from polluted samples without affecting the phage counts. Freezing cultures just before the end of the log-phage growth at (-70+/-10) degrees C with BSA-sucrose as cryoprotector, storing of 1-2 ml in glass vials at (-70+/-10) degrees C and using them directly to inoculate fresh broth allows the obtention of cultures ready for phage enumeration in about 2.5 h. All these developments have been incorporated into a procedure that makes the method for detecting phages infecting B. fragilis as workable as the standardised methods available for the detection of coliphages.
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Laffon B, Pásaro E, Méndez J. Effects of styrene-7,8-oxide over p53, p21, bcl-2 and bax expression in human lymphocyte cultures. Mutagenesis 2001; 16:127-32. [PMID: 11230554 DOI: 10.1093/mutage/16.2.127] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Styrene is one of the most important organic chemicals in use today. The highest human exposures to styrene take place by inhalation during the production of fibreglass-reinforced plastics. Styrene is oxidized by hepatic cytochrome P450 to styrene-7,8-oxide (SO), an epoxide that has been shown to induce chromosome aberrations, sister chromatid exchanges and micronuclei in many cell systems. In this work, the effect of SO on the expression of some genes involved in the cell cycle and apoptosis regulation in human white blood cells was studied. Lymphocyte cultures from four donors were exposed to 50 and 200 microM SO, 1% DMSO being the control. Aliquots of the cultures were taken at six different time points (30, 36, 42, 48, 60 and 72 h), total mRNA was extracted in each one of them and RT-PCR was carried out to analyze the expression of the genes p53, p21, bcl-2 and bax. Moreover, a cytokinesis block assay was performed to estimate cell proliferation kinetics by calculating the cytokinesis block proliferation index (CBPI), and to evaluate the number of cells undergoing apoptosis. Furthermore, apoptotic events were detected by the DNA fragmentation assay. In our results, a high interindividual variation in the expression of the studied genes was observed. Expression curves obtained for the four genes, together with the data from the CBPI and apoptotic cells scored, suggest that exposure to high levels of SO may induce a delay in the cell cycle, probably directed to allowing repair systems to act on the genotoxic damage produced, more than driving cells towards programmed cell death.
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Quevedo I, Rodríguez JA, Gejman R, Méndez J. [Silent adenoma type 3: the importance of the ultrastructural study in the differential diagnosis of pituitary adenoma associated with hyperprolactinemia in a case]. Rev Med Chil 2001; 129:295-8. [PMID: 11372297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
The association of hyperprolactinemia over 100 ng/ml and a pituitary adenoma is usually diagnostic of prolactinoma. However type 3 pituitary adenomas can occur with similar serum prolactin values. We report a 31 years old woman that consulted due to headache and photopsiae. She had a serum prolactin level of 148 ng/ml and imaging studies showed a solid tumor that occupied the sellar region and most of the left temporal fossa. The tumor was partially resected and the patient recovered her lost visual field. Light microscopy showed an acidophilic and in part chromophobe adenoma. Immuno-histochemistry was positive for prolactin and growth hormone. Electron microscopy disclosed features of a silent type 3 adenoma such as big cells with cytoplasmic prolongations, pleomorphic nuclei and a greatly developed rough endoplasmic reticulum.
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Iturburu IM, Emparan C, Ezpeleteta C, Escobar A, Méndez J. Surgical microbiology in risk patients undergoing abdominal surgery. REVISTA ESPANOLA DE ENFERMEDADES DIGESTIVAS : ORGANO OFICIAL DE LA SOCIEDAD ESPANOLA DE PATOLOGIA DIGESTIVA 2001; 93:77-86. [PMID: 11471231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
INTRODUCTION Incidence of surgical infection is greater among elderly patients undergoing surgery than among the general population, with a serious compromise regarding morbidity and mortality in this group of patients with increased risk. AIM OF THE STUDY To determine the microbiological features of surgical infections in patients over 65 years of age compared with those younger than 65. PATIENTS AND METHODS Over the past 2 years, 2,064 patients underwent surgery in our Department. One thousand three hundred sixty seven of those patients (66.7%) had 65 years of age or less and 688 (33.3%) were over 65. Patient characteristics regarding the type of surgery (degree of contamination) and the nature and type of the condition requiring surgery are reported. One hundred five hundred sixty two samples were submitted for microbiological study. The microbiological infectious pathogens and their characteristics were determined. The Chi-square test was used for the analysis of potential differences related to the age of the patient. RESULTS The rate of samples sent for microbiological study is higher among patients over 65. In addition, these patients show both quantitative and qualitative differences in their infectious microbiological spectrum, mainly in clean-contaminated, contaminated and dirty surgical procedures. Fungal infections play a significant role in this group of patients. CONCLUSIONS Facultative gram-negative bacilli, aerobic gram-positive cocci, and fungi are the main pathogens responsible of surgical infections in elderly patients, compared to all other patients, thus requiring specific antibiotic prophylactic and therapeutic regimes.
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Méndez J, Vega A, Ruiz P, Nombela L, Parajón A. 7. Fístula carótido-cavernosa como debut de síndrome de Ehlers-Danlos. Neurocirugia (Astur) 2001. [DOI: 10.1016/s1130-1473(01)70892-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Dufour E, Méndez J, Lázaro JM, de Vega M, Blanco L, Salas M. An aspartic acid residue in TPR-1, a specific region of protein-priming DNA polymerases, is required for the functional interaction with primer terminal protein. J Mol Biol 2000; 304:289-300. [PMID: 11090274 DOI: 10.1006/jmbi.2000.4216] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A multiple sequence alignment of eukaryotic-type DNA polymerases led to the identification of two regions of amino acid residues that are only present in the group of DNA polymerases that make use of terminal proteins. (TPs) as primers to initiate DNA replication of linear genomes. These amino acid regions (named terminal region (TPR protein-1 and TPR-2) are inserted between the generally conserved motifs Dx(2)SLYP and Kx(3)NSxYG (TPR-1) and motifs Kx(3)NSxYG and YxDTDS (TPR-2) of the eukaryotic-type family of DNA polymerases. We carried out site-directed mutagenesis in two of the most conserved residues of phi29 DNA polymerase TPR-1 to study the possible role of this specific region. Two mutant DNA polymerases, in conserved residues AsP332 and Leu342, were purified and subjected to a detailed biochemical analysis of their enzymatic activities. Both mutant DNA polymerases were essentially normal when assayed for synthetic activities in DNA-primed reactions. However, mutant D332Y was drastically affected in phi29 TP-DNA replication as a consequence of a large reduction in the catalytic efficiency of the protein-primed reactions. The molecular basis of this defect is a non-functional interaction with TP that strongly reduces the activity of the DNA polymerase/TP heterodimer.
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González-Tizón AM, Martínez-Lage A, Rego I, Ausió J, Méndez J. DNA content, karyotypes, and chromosomal location of 18S-5.8S-28S ribosomal loci in some species of bivalve molluscs from the Pacific Canadian coast. Genome 2000; 43:1065-72. [PMID: 11195339 DOI: 10.1139/g00-089] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The DNA content of 10 species of bivalve molluscs from British Columbia coast was determined by image analysis, and the karyotypes of the horse clam Tressus capax, the bent-nose macoma Macoma nasuta, and the nuttall's mahogany clam Nuttallia nuttallii are described here for the first time. We also have analyzed the location of rDNA loci using a 28S-5.8S-18S probe in four of these species: Mytilus californianus, M. trossulus, Macoma nasuta and N. nuttallii. Results obtained report new data about cytogenetic characteristics of bivalve molluscs.
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Méndez J, Stillman B. Chromatin association of human origin recognition complex, cdc6, and minichromosome maintenance proteins during the cell cycle: assembly of prereplication complexes in late mitosis. Mol Cell Biol 2000; 20:8602-12. [PMID: 11046155 PMCID: PMC102165 DOI: 10.1128/mcb.20.22.8602-8612.2000] [Citation(s) in RCA: 745] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evidence obtained from studies with yeast and Xenopus indicate that the initiation of DNA replication is a multistep process. The origin recognition complex (ORC), Cdc6p, and minichromosome maintenance (MCM) proteins are required for establishing prereplication complexes, upon which initiation is triggered by the activation of cyclin-dependent kinases and the Dbf4p-dependent kinase Cdc7p. The identification of human homologues of these replication proteins allows investigation of S-phase regulation in mammalian cells. Using centrifugal elutriation of several human cell lines, we demonstrate that whereas human Orc2 (hOrc2p) and hMcm proteins are present throughout the cell cycle, hCdc6p levels vary, being very low in early G(1) and accumulating until cells enter mitosis. hCdc6p can be polyubiquitinated in vivo, and it is stabilized by proteasome inhibitors. Similar to the case for hOrc2p, a significant fraction of hCdc6p is present on chromatin throughout the cell cycle, whereas hMcm proteins alternate between soluble and chromatin-bound forms. Loading of hMcm proteins onto chromatin occurs in late mitosis concomitant with the destruction of cyclin B, indicating that the mitotic kinase activity inhibits prereplication complex formation in human cells.
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García Páez JM, Carrera A, Cordón A, Jorge-Herrero E, Rocha A, Salvador J, Méndez J, Castillo-Olivares JL, Millán I, Sainz N. Uniaxial and biaxial tensile strength of calf pericardium used in the construction of bioprostheses: biomaterial selection criteria. J Biomater Appl 2000; 15:47-64. [PMID: 10972159 DOI: 10.1106/77v6-pmk9-duh4-llr8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Using morphological and mechanical criteria and applying a method involving paired samples that is widely employed in epidemiology, we obtained an excellent prediction of the mechanical behavior of the calf pericardium used in the construction of cardiac bioprostheses. The method of selection employed in this study may be a highly useful tool for guaranteeing the mechanical resistance of calf pericardium, with a very low level of error.
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96
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Méndez J. A three years following of a sample of 420 elderly subjects regarding their blood pressure levels and their degree of control of HTA. Am J Hypertens 2000. [DOI: 10.1016/s0895-7061(00)01006-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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97
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Méndez J. Predictor factors of evolution to hypertension (HT) of normotensive elderly subjets. Am J Hypertens 2000. [DOI: 10.1016/s0895-7061(00)01005-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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98
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Méndez J. Is hyperuricemia an independent cardiovascular risk factor in the elderly? Am J Hypertens 2000. [DOI: 10.1016/s0895-7061(00)00519-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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99
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Iglesias P, Selgas R, Méndez J, Fernández-Reyes MJ, Bajo MA, Aguilera A, Díez JJ. Short-term recombinant human growth hormone therapy does not modify growth hormone, thyrotropin and prolactin responses to thyrotropin-releasing hormone in adult dialysis patients. Nephrol Dial Transplant 2000; 15:856-61. [PMID: 10831641 DOI: 10.1093/ndt/15.6.856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND We recently have reported the first randomized, controlled study on the effects of short-term recombinant human growth hormone (rhGH|| therapy on the nutritional status of a group of malnourished adult dialysis patients. In order to evaluate whether rhGH administration exerts any influence on GH, thyrotropin (TSH|| and prolactin (PRL|| responses to TSH-releasing hormone (TRH||, we assessed these responses before and after rhGH therapy. METHODS GH, PRL and TSH responses to TRH before and 1 month after rhGH therapy in a group of adult dialysis patients were evaluated. Seventeen dialysis patients (11 on continuous ambulatory peritoneal dialysis/six on haemodialysis|| were studied (rhGH group, n=8; control group, n=9||. In the rhGH group, 0.2 IU/kg/day rhGH was administered subcutaneously. Each patient was tested with TRH (400 microg bolus i.v.|| on two separate occasions, just before and immediately after the treatment period. RESULTS rhGH treatment did not modify baseline serum GH concentrations (6.6+/-2.7 vs 4.1+/-1.1 microg/l||, paradoxical GH responses to TRH (six out of eight patients||, GH peak (11.9+/-4.6 vs 11.2+/-5.3 microg/l, NS|| or area under the secretory curve of GH (GH AUC; 19.1+/-4.5 vs 12.1+/-3.1 microg/h/l||. Both basal PRL (35.5+/-7.1 vs 36.7+/-8.6 microg/l|| and TSH (2.3+/-1.1 vs 2.8+/-1.7 mU/l|| concentrations, as well as their responses to TRH stimulation (PRL peak, 59.9+/-16.6 vs 59. 5+/-11.8 microg/l; TSH peak, 6.2+/-2.6 vs 7.1+/-3.9 mU/l||, were also unaffected by rhGH therapy. CONCLUSION These results suggest that short-term rhGH therapy does not significantly influence the magnitude of the somatotropic, lactotropic or thyrotropic response to TRH in adult dialysis patients. However, this finding has to be interpreted with caution due to the two different patient groups included in this study.
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100
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González-Tizón A, Martínez-Lage A, Ausio J, Méndez J. Polyploidy in a natural population of mussel, Mytilus trossulus. Genome 2000; 43:409-11. [PMID: 10791832 DOI: 10.1139/gen-43-2-409] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have analyzed natural polyploidy in a population of Mytilus trossulus from Vancouver Island (British Columbia, Canada) by means of cytogenetic techniques. Results obtained are the first reporting on this type of numerical chromosome aberrations in mussels.
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