Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Anim Physiol Anim Nutr (Berl) ; 102(1): e504-e508, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28983972

RESUMEN

The purpose of this study was to ascertain the composition and origin of certain gastroliths or gizzard stones from broiler breeders (Gallus gallus domesticus). Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction techniques were used as analysis tools. The main components resulted to be organic fibre and minerals referred to a pegmatite rock (quartz, feldspar albite and haematite) used as grit. Although the generally accepted purpose of gastroliths in chicken is the crushing and grinding of foodstuff in the ventriculus, the importance of mineral uptake from grit of iron and other essential elements such as Al, Ca, K, Cl, P, Ti, Mn, Mg, Cu, Zn and Zr (in ppm) as a secondary effect of the abrasion and dissolution of gastroliths should not be disregarded.


Asunto(s)
Alimentación Animal/análisis , Pollos/fisiología , Molleja de las Aves/fisiología , Silicatos de Aluminio , Animales , Dieta/veterinaria , Compuestos Férricos , Minerales , Compuestos de Potasio , Cuarzo
2.
Nat Prod Res ; : 1-8, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38742440

RESUMEN

Doryopteris raddiana (Presl) Fée, a traditional contraceptive in Mbya culture, lacks scientific scrutiny regarding its chemical composition and contraceptive efficacy. Employing X-ray fluorescence, Fourier-transform infrared spectroscopy, and thermal analysis, we explored the plant's organs. Multielemental analysis excluded toxic elements. Key phytoconstituents identified by gas chromatography-mass spectrometry in the extracts obtained through infusion were glycerine, 1,3-dimethyl propane, and catechol in leaves; glycerine, cis-13-octadecenoic acid methyl ester, and 2-deoxy-D-erythro-pentose in stems and roots. Among these chemicals, glycerine emerged as the sole constituent with contraceptive potential, particularly intravaginally. Extract activity tests conducted on ram spermatozoa exhibited a reduction in the percentage of rapid spermatozoa but no significant impact on total motility, progressive motility, or viability. The reported data would only weakly support the advocated contraceptive action of this fern upon vaginal application, not through the oral administration of its decoction.

3.
Rev Gastroenterol Mex ; 77(3): 153-6, 2012.
Artículo en Español | MEDLINE | ID: mdl-22921207

RESUMEN

Intussusception is an infrequent cause of mechanical intestinal obstruction in the adult. We present herein two clinical cases of intussusception with different etiologies. In the first case, the underlying cause was a lipoma, and in the second, it was metastasis from melanoma. In both cases the intussusception was identified through computed tomography and treatment was intestinal resection. Pathologic anatomy provided the definitive diagnosis. Etiology is diverse and it is more common for obstruction to be due to organic lesions that are malignant at the level of the colon and benign at the level of the small bowel. Currently there are more preoperative diagnoses thanks to the advances made in imaging study techniques. Intestinal resection continues to be the treatment of choice in the majority of cases, because of the high percentage of malignant lesions as the underlying cause.


Asunto(s)
Obstrucción Intestinal/etiología , Intususcepción/complicaciones , Anciano de 80 o más Años , Procedimientos Quirúrgicos del Sistema Digestivo , Femenino , Humanos , Neoplasias Intestinales/complicaciones , Neoplasias Intestinales/patología , Obstrucción Intestinal/patología , Obstrucción Intestinal/cirugía , Intususcepción/patología , Intususcepción/cirugía , Masculino , Melanoma/complicaciones , Melanoma/patología , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
4.
Artículo en Inglés, Español | MEDLINE | ID: mdl-33386282

RESUMEN

Parathyroidectomy has evolved over the years from bilateral neck exploration to a single gland approach using minimally invasive surgery. The precise presurgical localization of the problem gland, using functional techniques, such as double-phase scintigraphy with [99mTc] Tc-MIBI including SPECT-CT and PET-CT with [18F]-Choline and morphological ones, such as ultrasound have played a crucial role in this paradigm's shift. Radioguided surgery techniques have also adapted and grown with new contributions known for their indication in other fields. Thus, we currently have a wide range of techniques that have been added to the minimally invasive radioguided parathyroidectomy with [99mTc] Tc-MIBI, which was the first on the stage and for which more experience exists. Among them, in this update, we will discuss parathyroidectomy using ultrasound-guided ROLL technique as well as with the use of 125I seeds and finally, hybrid techniques that use radiotracer and fluorescence.

6.
Rev Gastroenterol Mex ; 75(3): 335-8, 2010.
Artículo en Español | MEDLINE | ID: mdl-20959187

RESUMEN

Epithelioid hemangioendothelioma is an uncommon tumor of vascular endothelial cell origin with a clinical course between hemangioma and angiosarcoma. Clinical manifestations and radiological findings are nonspecific, and histopathologic examination is required to establish a definitive diagnosis. Currently, hepatic resection or liver transplantation is the best therapeutic options. Because of its unknown biological behavior, local resection and radio-frequency ablation, although an uncommon treatment method, can be performed in the absence of extrahepatic or diffuse involvement.


Asunto(s)
Ablación por Catéter/métodos , Hemangioendotelioma Epitelioide/cirugía , Neoplasias Hepáticas/cirugía , Hemangioendotelioma Epitelioide/patología , Humanos , Inmunohistoquímica , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
11.
Dalton Trans ; 44(3): 1264-72, 2015 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-25415492

RESUMEN

The magnetic properties of two similar Er(3+) complexes have been investigated. [Er(tpm)3(bipy)] (Htpm = 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and bipy = 2,2'-bipyridine) displays thermally activated slow relaxation of magnetisation under a zero direct-current (DC) field. Under an applied HDC field of 1000 G, [Er(tpm)3(bipy)] exhibits two thermally activated processes with energy barriers of 9 and 40 K, while [Er(tfa)3(bipy)] (Htfa = 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione) shows only one activated process with a barrier of 15 K. Both compounds are luminescent in the solid state, emitting in the near IR region.

12.
Res Microbiol ; 144(9): 729-40, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8190999

RESUMEN

Differential scanning calorimetry (DSC) was used to investigate the thermal stability and behaviour of the lipopolysaccharides (LPS) of the outer membrane of Gram-negative bacteria and their lipid portion. DSC curves of LPS show thermal features between 200 and 129 degrees C (depolymerization) and between -13 and -36 degrees C (cooling phase transition). Both effects were related to the relative strength of the linkage types in the O-chain structure and to their capacity for intermolecular hydrogen bonding. DSC curves of lipids A show endotherm peaks between 40 and 24 degrees C, around 15 degrees C and between -23 and -4 degrees C. Based on these effects, strong differences in thermal behaviour can be observed between that of Brucella and Vibrio cholerae on the one hand, and that of Escherichia coli and Shigella flexneri on the other. Fluidity of the acyl chains and lyotropism, which are important parameters in expression of biological activities, are discussed using the above data. To explain some properties, fluidity could be related to the temperature of the gel<==>liquid crystalline (beta<==>alpha) phase transition, which occurs at physiological temperature. Nevertheless, fluidity could be related to temperature of the previous thermal effect (between 6 and 20 degrees C), for which a softening or partial melting of the sample has been evidenced. The thermal effect measured between -23 degrees C and -4 degrees C indicates a greatly reduced water concentration of lipid A from Brucella, thus explaining its early fusion process and its activity by means of hydrophobic interactions.


Asunto(s)
Rastreo Diferencial de Calorimetría/métodos , Bacterias Gramnegativas/química , Lípido A/química , Lipopolisacáridos/química , Brucella abortus/química , Escherichia coli/química , Técnicas In Vitro , Shigella flexneri/química , Temperatura , Vibrio cholerae/química
13.
Biotechnol Prog ; 7(6): 526-33, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1367753

RESUMEN

The present work constitutes an entirely novel contribution in the scope of microbiology and especially in taxonomy, introducing thermolysis curves as a rapid method of characterization of fungal polysaccharides and bacterial lipopolysaccharides. The thermal analysis techniques applied were thermogravimetry and derivative thermogravimetry (TG-DTG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). Each thermogram of a sample is represented by one or a few temperatures and, in DSC, by complementary enthalpy data. The temperatures of the thermograms from structurally unknown polysaccharides are compared with those used as references, and thus, information on their composition, linkage types, and anomeric configuration can be deduced. The situation is more complicated for bacterial lipopolysaccharides, but in whatever mode, a structural estimation is always possible. In the course of the development and validation of the thermal method, structural findings on relative stabilities of linkage types (valuable in carbohydrate research) have been recognized and are therefore also described in this work.


Asunto(s)
Lipopolisacáridos/química , Polisacáridos/química , Biotecnología , Rastreo Diferencial de Calorimetría , Conformación de Carbohidratos , Secuencia de Carbohidratos , Análisis Diferencial Térmico , Hongos/química , Hongos/clasificación , Bacterias Gramnegativas/química , Bacterias Gramnegativas/clasificación , Datos de Secuencia Molecular , Termogravimetría
14.
Laryngoscope ; 110(9): 1505-10, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10983951

RESUMEN

OBJECTIVE/HYPOTHESIS: The objective of this study was to evaluate the morphological and microchemical changes that affect sclerotic stapes in otospongiosis and van der Hoeve syndrome. METHODS: A scanning electron microscope equipped with an energy-dispersive x-ray analyzer was used in the experiments. RESULTS: In otosclerosis, focal lesions are poorly mineralized, with low calcium salt and reduced calcium-to-phosphorus (Ca/P) ratio (1.9:1). This finding correlates with a spongiotic type of lesion and indicates unstable mineralization with possible change from hydroxyapatite to calcium triphosphate. In van der Hoeve syndrome the presence of magnesium in stapes suggests osteoclastic function stimulation. The osteoclasts secrete many protons, causing an acidified microenvironment. Brushite is formed, and Ca/P ratio decreases in comparison with that of control patients (2.0:1 vs. 2.6:1).


Asunto(s)
Osteogénesis Imperfecta/patología , Otosclerosis/patología , Estribo/ultraestructura , Microanálisis por Sonda Electrónica , Humanos , Magnesio/análisis , Microscopía Electrónica de Rastreo , Minerales/análisis , Osteoclastos/fisiología , Osteogénesis Imperfecta/diagnóstico por imagen , Osteogénesis Imperfecta/metabolismo , Otosclerosis/diagnóstico por imagen , Otosclerosis/metabolismo , Radiografía , Espectroscopía Infrarroja por Transformada de Fourier , Estribo/química , Estribo/diagnóstico por imagen , Estribo/patología , Síndrome
15.
Acta Crystallogr C ; 56 (Pt 9): 1132-5, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10986508

RESUMEN

In the title compounds, C(6)H(5)NH(3)(+).H(2)PO(3)(-) and C(6)H(5)NH(3)(+).C(2)HO(4)(-).0.5H(2)O, the NH(3)(+) groups of the anilinium ion are ordered at room temperature. The rotation of these groups along the N-C(aryl) bond, which is often observed at room temperature in other anilinium compounds, is prevented by hydrogen bonds between the NH(3)(+) group and the anions. In both compounds, the geometry of the cation is significantly distorted from D(6h) to a symmetry close to C(2v). The angle ipso to the substituent is significantly larger than 120 degrees, as expected from the sigma-electron-withdrawing character of the NH(3)(+) group.

19.
An Med Interna ; 21(8): 378-81, 2004 Aug.
Artículo en Español | MEDLINE | ID: mdl-15373720

RESUMEN

BACKGROUND: Few information about descriptive studies of autoimmunity in diabetes mellitus type 1 onset patients and family exist. The aim of our study was to analyze clinical and biochemical parameters of onset diabetes mellitus type 1 patients and first degree families. PATIENTS AND METHODS: Forty seven onset diabetes mellitus type 1 patients and 148 first degree families were studied, between January 1999 and December 2002, in the west area of Valladolid. In all cases and families an anthropometric study and biochemical determination with autoimmunity levels were performed. RESULTS: Average age in onset diabetes mellitus type 1 patients was 16.09 (9.36) years, without differences between males (32 cases, 68%) and females (15 cases, 32%), with an incidence of 4.66 cases/100,000 habs./year. Average values of peroxidase antibodies (antiPTO) and glutamic descarboxilase antibodies (antiGAD) were higher in diabetic patients than in families. No differences were detected in insulin antibodies (IAA) and tiroglobuline antibodies (antiTG). No correlation was detected between anti TPO and anti pancreas. Autoantibodies did not influence in glycemic control. Average dose of NPH insulin and regular insulin were 27.58 (13.88) UI/d y 3.05 (4.90) UI/d, respectively. CONCLUSIONS: Average age of onset diabetes mellitus type 1 patients was similar than other studies, with a high frequency of males. Values of antiGAD y antiTPO were higher in diabetic patients than families. No correlation between autoimmunity and glycemic control was detected.


Asunto(s)
Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/genética , Adolescente , Adulto , Distribución por Edad , Edad de Inicio , Autoanticuerpos/análisis , Niño , Preescolar , Diabetes Mellitus Tipo 1/sangre , Familia , Femenino , Glutamato Descarboxilasa/inmunología , Humanos , Lactante , Insulina/inmunología , Yoduro Peroxidasa/inmunología , Masculino , Factores Sexuales , España/epidemiología
20.
Acta Otorrinolaringol Esp ; 52(2): 85-93, 2001 Mar.
Artículo en Español | MEDLINE | ID: mdl-11428276

RESUMEN

Morphological and microchemical changes that effect to the otosclerotic stape in the Van der Hoeve's syndrome were examined with a scanning electron microscope equipped with an energy dispersive X-ray fluorescence. Using the Ca/P ratio as criterion--measured by the characteristic x-ray fluorescence--it was shown that the Van der Hoeve stape had a higher Ca/P ratio (2.6:1) as compared to the normal stape (2:1). The Van der Hoeve's syndrome lesions as poorly mineralized, with low calcium salt and apparent increase of phosphates. This finding indicates a possible change from hydroxyapatite (or apatite) to brushite, which imply an acidification of bone.


Asunto(s)
Otosclerosis/genética , Otosclerosis/patología , Estribo/ultraestructura , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Densidad Ósea , Niño , Femenino , Humanos , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Linaje , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Estribo/química , Síndrome
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA