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2.
Farm. comunitarios (Internet) ; 14(Supl 1): 1, junio 2022. ilus
Artículo en Español | IBECS (España) | ID: ibc-209446

RESUMEN

PRESENTACIÓN DEL CASO: varón, 88 años, refiere episodios de tos crónica e irritación de garganta que le preocupan e incapacitan. Últimamente se encuentra asténico. Se le ofrece SFT y acepta. Problemas de salud actuales: HTA, hiperlipidemia, ERGE, tos, anemia, disuria, astenia.T ratamiento actual: enalapril 10 mg + nitrendipino 20 mg (1/0/0), simvastatina 20 mg (0/0/1), omeprazol 20 mg (1-0-0, incumple), carbocisteina 50 mg/ml (10/10/10), paracetamol 1 g (si dolor), sulfato ferroso 325 mg (1-0-0, incumple). Otros datos de interés PA: 119/52. Resto de parámetros bioquímicos dentro de la normalidad.EVALUACIÓN: se detectan los siguientes PRMs y RNMs: 1.- Enalapril/nitrendipino. Sospecha de PRM: reacción adversa, posible causa de tos. RNM: inseguridad no cuantitativa 2.- Omeprazol. PRM: incumplimiento terapéutico, posible causa de tos por ERGE no controlado. RNM: inefectividad cuantitativa3.- Carbocisteína. PRM: medicamento no necesario, no existe indicación. RNM: efecto de medicamento innecesario4.- Hierro. PRM: incumplimiento terapéutico, posible causa de anemia. RNM: inefectividad cuantitativa 5.- Disuria. PRM: problema de salud no tratado, el paciente refiere dificultad al miccionar. RNM: problema de salud no tratado.INTERVENCIONES: a.- Emitimos informe al MAP proponiendo valorar tratamiento antihipertensivo (enalapril) como causa de tos, poniéndole también en antecedentes del incumplimiento terapéutico de hierro y omeprazol e informándole de la astenia y la disuria. b.- Se retira carbocisteina, medicamento no sujeto a prescripción médica y, por tanto, susceptible de indicación farmacéutica. Se plantea sustitución por comprimidos para chupar como tratamiento sintomático alternativo. c.- Para mejorar la adherencia terapéutica del paciente a su farmacoterapia se le oferta el servicio de SPD, que acepta. Resultados1. (AU)


Asunto(s)
Humanos , Masculino , Anciano de 80 o más Años , Farmacia , Servicios Farmacéuticos , Pacientes , Astenia , Terapéutica , Quimioterapia
3.
Biomaterials ; 20(6): 539-45, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10213357

RESUMEN

The use of biological materials in the construction of bioprostheses requires the application of different chemical or physical procedures to improve the mechanical performance of the material without producing any undesirable effects. A number of cross-linking methods have been tested in biological tissues composed mainly of collagen. The basis for most of them is the use of glutaraldehyde (GA), which acts on the Lys or Hyl residues. We have studied the effects of alternative chemical treatments: diphenylphosphorylazide (DPPA) and ethyldimethylaminopropyl carbodiimide (EDAC). Their mechanism of action is based on the activation of the carboxyl groups, which then permits their cross-linking to amino groups. As a control, we employed conventional treatment with GA, applying it to bovine pericardium and collagen membranes removed from bovine pericardium. The analysis of the Lys and Hyl residues showed that DPPA and EDAC produced 50% of the chemical change provoked by GA. This value was even lower in the trials with collagen. In terms of the resistance to collagenase degradation, chemical cross-linking with GA provided much greater protection in both materials (3.81 +/- 3.47 nmol of amino acid/mg dry tissue for pericardium and 4.41 +/- 1.13 nmol of amino acid/mg dry tissue for collagen). Treatment with DPPA also protected pericardium (13.11 +/- 6.57 nmol amino acid/mg dry tissue) although the values for collagen was lower (50.0 +/- 32.4 nmol amino acid/mg dry tissue). Treatment with EDAC was much less protective than the other two chemical reagents (43.28 +/- 17.4 and 55.85 +/- 14.57 nmol amino acid/mg dry tissue for pericardium and collagen, respectively). The degree of tissue calcification after implantation of the chemically treated materials into young rats was considerably greater for GA and DPPA (32.9 +/- 18.8 and 36.3 +/- 13.3 mg g(-1) dry tissue, respectively) than with EDAC (18.0 +/- 7.2 mg g(-1) dry tissue; P < 0.001). After 60 days of implantation, the values for GA and EDAC were higher(124.1 +/- 31.3 and 124.6 +/- 21.0 mg g(-1) dry tissue, respectively) versus 34.6 +/- 19.2 mg g(-1) dry tissue for DPPA. There were no significant differences in collagen levels in samples treated with GA or EDAC after 30 days of implantation, although both groups showed significant differences when compared with DPPA-treated samples (P < 0.001). After 60 days of implantation, there were no significant differences among these three treatments in terms of the calcium accumulated on samples.


Asunto(s)
Materiales Biocompatibles/farmacología , Colágeno/química , Colágeno/efectos de los fármacos , Reactivos de Enlaces Cruzados/química , Reactivos de Enlaces Cruzados/farmacología , Pericardio/efectos de los fármacos , Análisis de Varianza , Animales , Azidas/farmacología , Materiales Biocompatibles/química , Carbodiimidas/farmacología , Bovinos , Glutaral/farmacología , Hidroxilisina/análisis , Lisina/análisis , Pericardio/química , Pericardio/fisiología , Ratas , Ratas Wistar
4.
Biomaterials ; 22(20): 2731-40, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11545307

RESUMEN

The mechanical behavior of ostrich pericardium was studied for the purpose of assessing its utility in the construction of bioprosthetic cardiac valve leaflets. The tissue was tested biaxially using a hydraulic simulator that subjected it to increasing stress until rupture. One hundred eighty trials were performed, 36 with unsutured pericardium and four series of 36 trials each with pericardium sutured with silk, Prolene, nylon or Gore-Tex. The samples were tested in pairs from three different pericardial regions. One sample from each pair (the predictive specimen) was assessed according to morphological and mechanical criteria, while the other (the predicted or selectable specimen) was subjected only to morphological analysis. The findings show that ostrich pericardium treated with glutaraldehyde according to standard methods has an excellent resistance to rupture in biaxial testing, withstanding stresses of up to 100 MPa, and never lower than 30 MPa. Its resistance to rupture is lowered by suturing, a loss that is less pronounced when silk sutures are used. The results with Gore-Tex are very homogeneous and the elastic behavior of the pericardium/suture unit appears to be similar to that of unsutured tissue, suggesting that the interaction between the two biomaterials is minor. Similar results were observed in the series sutured with Prolene and nylon. The use of paired samples makes it possible to closely estimate the mechanical behavior of the tissue in a given zone by determining that of its mate. The statistical study shows that this estimation is not conditioned by the suture employed, thus validating this approach and providing more precise criteria for tissue selection.


Asunto(s)
Materiales Biocompatibles , Bioprótesis , Prótesis Valvulares Cardíacas , Pericardio , Suturas , Animales , Ensayo de Materiales , Struthioniformes
5.
Biomaterials ; 23(16): 3473-8, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12099291

RESUMEN

Chemical modification of pericardium-based cardiac valves tends to reduce the relatively high degree of biodegradation and calcification of the implanted bioprostheses. We analysed the tissue properties of pericardium from young calves and pigs after crosslinking with different agents (glutaraldehyde. diphenylphosphorylazide (DDPA), 1-ethyl-3,3-dimethyl-aminopropyl-carbodiimide (EDAC)) and when exposed to anticalcification treatments (chloroform/methanol or ethanol) prior to glutaraldehyde (GA) crosslinking. Protein extraction after tissue homogenisation in the presence of detergents showed that crosslinking using GA or DPPA was much more effective. The amounts of protein extracted from these two groups of chemically modified pericardium were significantly lower: the other modified tissues presented only a slight reduction when compared with untreated tissue. Matrix metalloproteinases- (MMP) 2 and 9 were detected in native pericardium from calf and pig by zymography. While the MMP-9/MMP-2 activity ratio was close to 1 in pig pericardium, it was 8.5-fold higher in bovine tissue. Crosslinking with GA and with DPPA almost completely abolished gelatinase activities, even when equal amounts of solubilised protein were loaded onto the zymograms. Anticalcification treatments followed by GA crosslinking or treatment with EDAC were not as effective in reducing gelatinase activities; but, interestingly, a relative reduction of MMP-9 versus MMP-2 was detected. The presence of these gelatinase activities in pericardium may contribute to the in vivo degradability of pericardium-based cardiac valves.


Asunto(s)
Materiales Biocompatibles , Reactivos de Enlaces Cruzados/farmacología , Gelatinasas/metabolismo , Animales , Azidas/farmacología , Carbodiimidas/farmacología , Bovinos , Gelatina/química , Gelatina/metabolismo , Glutaral/farmacología , Pericardio/efectos de los fármacos , Pericardio/enzimología , Porcinos
6.
Biomaterials ; 22(20): 2759-67, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11545310

RESUMEN

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.


Asunto(s)
Pericardio , Animales , Ensayo de Materiales , Porcinos , Resistencia a la Tracción
7.
Theriogenology ; 56(4): 671-6, 2001 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11572447

RESUMEN

In ruminants, glycoproteins synthesized in the outer layers of the trophoblast enter the maternal bloodstream. The assay of their concentration in plasma or in serum can be used for pregnancy diagnosis and to indicate feto-placental health status. In this study, concentrations of the pregnancy-associated glycoprotein (PAG) were investigated in the milk of dairy goats. The mean concentrations of PAG in milk were significantly higher in pregnant than in non-pregnant goats throughout the sampling period. Positive milk PAG levels were found in all pregnant animals from Day 32 after breeding, but remained at negative values in nonpregnant ones. This study reports for the first time a pregnancy diagnosis based on milk concentrations of PAG, that could be of great use on the farm.


Asunto(s)
Glicoproteínas/biosíntesis , Cabras/fisiología , Leche/química , Proteínas Gestacionales/biosíntesis , Pruebas Inmunológicas de Embarazo/veterinaria , Animales , Femenino , Glicoproteínas/análisis , Masculino , Embarazo , Proteínas Gestacionales/análisis , Pruebas Inmunológicas de Embarazo/métodos , Radioinmunoensayo/veterinaria
8.
Theriogenology ; 52(4): 717-25, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10734369

RESUMEN

Different RIA systems available for measuring the concentrations of pregnancy-associated glycoproteins (PAGs) in dairy goats were compared in order to evaluate their accuracy in early pregnancy diagnosis. Plasma concentrations of PAGs were determined by 3 heterologous RIA systems with a bovine PAG standard and tracer in combination with antisera anti-ovine PAG (RIA 1), anti-caprine PAG55 + 62 (RIA 2), anti-caprine PAG55 + 59 (RIA 3), and by 2 homologous RIA systems that employed caprine PAG55 + 62 and caprine PAG55 + 59 and their specific antisera (RIAs 4 and 5, respectively). In all of the RIAs, the mean concentrations of PAGs were significantly higher (P < 0.01) in pregnant than in nonpregnant goats from Day 21 onwards after breeding. On Day 21, the accuracy rates of early pregnancy diagnoses were 56% (RIA 1), 96% (RIA 2), 99% (RIA 3), 95% (RIA 4) and 90% (RIA 5), whereas on Day 28 these rates were > 99% for RIAs 2, 3, 4 and 5. The RIAs for PAGs depend on proteins from the placenta being present in maternal plasma and require only a single sample of blood, to distinguish pregnant goats from those that fail to return to estrus for other reasons. The homologous and semi-heterologous assays are highly accurate as early as Day 21 of pregnancy.


Asunto(s)
Proteínas Gestacionales/sangre , Pruebas de Embarazo/veterinaria , Animales , Cruzamiento , Bovinos , Femenino , Glicoproteínas/sangre , Cabras , Embarazo , Pruebas de Embarazo/métodos , Radioinmunoensayo , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Factores de Tiempo
9.
Can Vet J ; 41(7): 562-4, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10907580

RESUMEN

Anatomical, behavioral, histological, endocrinological, and cytogenetic characteristics were determined in a horned intersex goat. Histology of the gonads confirmed that the goat was a true hermaphrodite. Cytogenetic analysis showed that it was a chimera (60XX/60XY). Use of laparoscopy allowed determination of characteristics of the internal gonads.


Asunto(s)
Quimera , Trastornos del Desarrollo Sexual/veterinaria , Enfermedades de las Cabras/genética , Animales , Trastornos del Desarrollo Sexual/genética , Femenino , Cabras , Gónadas/anomalías , Masculino , Cromosoma X/genética , Cromosoma Y/genética
10.
Transplant Proc ; 43(3): 755-7, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21486592

RESUMEN

We report a 66-year-old woman who underwent emergency orthotopic liver transplantation due to acute liver failure. The donor's liver graft displayed extensive arteriosclerosis, involving the celiac trunk and hepatic artery. Arterial revascularization of the graft could not be achieved, requiring an arterioportal shunt between the gastroduodenal artery and the portal vein of the recipient. During the early postoperative period, the patient's clinical condition and liver function tests improved rapidly; the patient was discharged on postoperative day 30. Two months later, she developed acute cholangitis. Ischemic-type stenosis of the intrahepatic biliary tree was present, so successful elective retransplantation was undertaken at the ninth postoperative month. In our experience, portal vein arterialization may be useful as a bridging therapy in extreme situations.


Asunto(s)
Arteria Hepática/fisiopatología , Trasplante de Hígado , Vena Porta/fisiopatología , Anciano , Femenino , Humanos
14.
Histol Histopathol ; 24(12): 1487-98, 2009 12.
Artículo en Inglés | MEDLINE | ID: mdl-19795347

RESUMEN

The purpose of this study was to assess the effects of the addition of Nitroglycerin or Nicorandil to University of Wisconsin solution in long-term myocardial preservation. In a model of heterotopic heart transplantation in pigs, the donor heart was preserved for 24 hours by means of continuous perfusion in this solution, in the presence or absence of these drugs. During this period, the oxygenation and pH of the solution were measured, as were lactate concentrations and enzyme release. At regular intervals following reperfusion we measured the concentrations of enzymes, antioxidants, glutathione peroxidase, glutathione reductase, malondialdehyde, endothelin and nitrite, and, two hours later, samples of both ventricles were taken for a morphological study. In the treated groups there was a higher lactate production during preservation and, during reperfusion, the signs of contracture and the elevation of enzyme levels were more marked than in the untreated groups. In contrast, the glutathione reductase concentrations did not decrease during the first phase of reperfusion and were directly correlated with those of antioxidants, endothelin levels increased less than in the untreated groups and, in the case of nitroglycerin, the nitrite concentration was significantly greater than in the remaining groups. We conclude that nitroglycerin and nicorandil improved the oxidative state and endothelial function and did not produce substantial morphological changes, but increased cell necrosis and contracture, possibly due to the duration of ischemia.


Asunto(s)
Endotelio/efectos de los fármacos , Nicorandil/farmacología , Nitroglicerina/farmacología , Preservación de Órganos/métodos , Vasodilatadores/farmacología , Adenosina , Alopurinol , Animales , Antioxidantes/metabolismo , Calcio/análisis , Dióxido de Carbono/análisis , Creatina Quinasa/análisis , Endotelina-1/efectos de los fármacos , Endotelio/fisiología , Técnica del Anticuerpo Fluorescente Indirecta , Glucosa/análisis , Glutatión , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Trasplante de Corazón/métodos , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/ultraestructura , Concentración de Iones de Hidrógeno , Inmunohistoquímica , Insulina , L-Lactato Deshidrogenasa/análisis , Ácido Láctico/análisis , Malondialdehído/análisis , Miocardio/metabolismo , Miocardio/ultraestructura , Nitritos/análisis , Soluciones Preservantes de Órganos , Oxígeno/análisis , Soluciones Farmacéuticas/farmacología , Rafinosa , Distribución Aleatoria , Porcinos , Factores de Tiempo
15.
Reprod Domest Anim ; 40(3): 191-5, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15943690

RESUMEN

Goat semen is different from that of other domestic species in its limited tolerance to the inclusion of egg yolk in the freezing medium, and this tolerance depends on the presence of enzymes in the seminal plasma that react with egg yolk, producing toxic compounds to the spermatozoa. Moreover, the goat is a seasonal breeder that shows variations in semen quality throughout the year, and those variations may affect semen freezability; hence in freezing protocols, for instance, removal of seminal plasma (washing) yields varying results. This work was designed to study this problem in Canary goats: semen from six males was collected in spring, autumn or winter, washed or non-washed, diluted in a freezing extender with 1.5, 6 or 12% egg yolk, frozen, and thawed after 2 days, 2 or 6 months of cryopreservation. The effect of egg yolk concentration in the freezing extender was far more important than the effect of washing or season on sperm cryosurvival. The quality of frozen-thawed semen tended to improve as egg yolk concentration increased regardless of the effects of season, washing or period of cryopreservation. Washing produced a positive effect on frozen-thawed semen collected during spring or autumn, but the difference decreased as the concentration of yolk increased. However, washing produced a negative effect on frozen-thawed semen collected during winter, diluted with either 6 or 12% egg yolk. There was no apparent seasonal effect on gross measures of sperm production but the seasonal effect was ever present and was reinforced by freezing.


Asunto(s)
Criopreservación/veterinaria , Yema de Huevo/fisiología , Cabras , Estaciones del Año , Preservación de Semen/veterinaria , Semen/fisiología , Acrosoma/ultraestructura , Animales , Membrana Celular/ultraestructura , Masculino , Motilidad Espermática , Espermatozoides/ultraestructura
16.
J Pediatr Gastroenterol Nutr ; 23(1): 29-33, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8811520

RESUMEN

One hundred forty-one children with insulin-dependent diabetes mellitus were screened for serum immunoglobulin A (IgA) antigliadin antibodies by means of an enzyme-linked immunosorbent assay (ELISA) method. None of them had gastrointestinal symptoms, and no major nutritional disturbances were detected except for a girl with moderate growth delay. Twelve patients with positive IgA antigliadin antibodies on two or more consecutive measurements underwent a small intestinal biopsy; four of them had a subtotal villous atrophy, and celiac disease was diagnosed; in another patient, a partial villous atrophy was observed. Children suffering from both diabetes and celiac disease showed an onset of diabetes at a younger age than did nonceliac patients. Prevalence of celiac disease in the screened population is 2.85%, which is higher than in the general population of the Comunidad Valenciana (one in 2,500 live births).


Asunto(s)
Enfermedad Celíaca/diagnóstico , Diabetes Mellitus Tipo 1/complicaciones , Gliadina/inmunología , Inmunoglobulina A/sangre , Adolescente , Biomarcadores/sangre , Enfermedad Celíaca/complicaciones , Enfermedad Celíaca/epidemiología , Niño , Preescolar , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoglobulina A/inmunología , Incidencia , Masculino , Prevalencia , Estudios Prospectivos
17.
Reprod Domest Anim ; 36(3-4): 147-51, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11555360

RESUMEN

Ovaries of unilaterally ovulated goats (n=21) were used to study follicular morphological features (proportion and degree of atresia, oestradiol production in vitro and progesterone production of granulosa cells in culture). Follicles were dissected out and classified as small (1-2 mm), medium (2-4 mm) and large (>4 mm). Morphological and physiological features were compared in each size class between ovaries bearing and not bearing corpora lutea (CLO and NCLO, respectively). Within the same size class, there was no difference in proportion or in degree of atresia, between CLO and NCLO. A significant effect of follicular size on oestradiol production in vitro was detected, but no effect of the corpus luteum was found. Finally, progesterone production of granulosa cells in culture was significantly higher in CLO than in NCLO after 24 h (p < 0.05) and also after 90 h (p < 0.01) of culture. This higher progesterone production by CLO granulosa cells in culture could be explained by local influence of the corpus luteum stimulating the steroidogenic activity but not aromatase activity. Further studies are needed to clarify possible factors and pathways for this local effect of the corpus luteum upon follicular physiology.


Asunto(s)
Cuerpo Lúteo/fisiología , Cabras/fisiología , Folículo Ovárico/fisiología , Animales , Supervivencia Celular , Células Cultivadas , Estradiol/biosíntesis , Femenino , Atresia Folicular/fisiología , Células de la Granulosa/metabolismo , Folículo Ovárico/anatomía & histología , Folículo Ovárico/patología , Progesterona/biosíntesis
18.
Reprod Domest Anim ; 37(6): 375-8, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12464078

RESUMEN

The effects of bilateral vasectomy on the seminal characteristics were assessed in six bucks of the Canarian breed. In addition, we tried to establish the effects of vasectomy on the plasmatic concentrations of testosterone and the libido of the bucks. Semen samples were collected once a week from 8 weeks before to 16 weeks after vasectomy; blood samples were collected prior to vasectomy, and then at once and 1 week after vasectomy and every 2 weeks from the week 4 to the end of the experiment. One week after the vasectomy, ejaculated spermatozoa were non-motile and the percentage of live spermatozoa was below 5% in all vasectomized males; in addition, the total number of cells/ejaculate was 3100 x 106 and 30 x 106 spermatozoa in the control and vasectomized males, respectively. Our results suggest that the vasectomized males may be used as oestrus detectors, without risks of accidental fecundating, only 1 week after vasectomy. Before vasectomy, no significant differences were observed in plasma levels of testosterone between the vasectomized and control males (5.4 +/- 1.2 and 3.9 +/- 1.4 ng/ml, respectively); from 4 to 12 weeks after vasectomy, a marked decrease in the testosterone concentration in all males (vasectomized and control bucks) was observed. From 12 weeks after vasectomy until the end of the experiment, four of the vasectomized males and the control males recovered their normal libido. The results suggest that vasectomy did not exert a remarkable effect on the steroidogenic functionality of the testicle.


Asunto(s)
Cabras/fisiología , Semen/fisiología , Testosterona/sangre , Vasectomía/veterinaria , Animales , Conducta Animal , Estudios de Casos y Controles , Cabras/sangre , Masculino , Recuento de Espermatozoides/veterinaria , Vasectomía/métodos
19.
J Mater Sci Mater Med ; 12(10-12): 1013-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-15348357

RESUMEN

The purpose of this study was to evaluate the influence of two anticalcification pre-treatments (chloroform/methanol and ethanol) and serum conditioning of glutaraldehyde-crosslinked bovine pericardium on the calcification degree and the presence of gelatinase activities in a subcutaneous implantation model in rats. Regarding calcification of the implants, glutaraldehyde control treatments showed a significatively higher calcification degree than pericardium treated with anticalcification reagents. Serum conditioning of glutaraldehyde treated tissues did not influence the calcification degree; moreover, no differences were found in these samples with the time of implantation (30 and 90 days). On the other hand, anticalcification treatments resulted in a very significant decrease in the calcium content in the implanted membranes. Gelatinase activities were detected by gelatin zymography in almost all the implanted samples. However, control tissues with and without serum conditioning showed less gelatinase activities than those samples pre-treated with anticalcification treatments. Metalloproteinase (MMP-2) activity was detected in all the samples analyzed but a higher expression of MMP-9 was detected in those implants treated with chloroform/methanol and ethanol. Additional gelatinase activities showing lower molecular weight than MMP-2 were also detected in both anticalcification treated samples. The presence of these gelatinase activities is probably due to host cellular infiltrates and could contribute to the biomaterial degradation.

20.
J Biomed Mater Res ; 62(1): 73-81, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12124788

RESUMEN

The mechanical behavior of sutured ostrich pericardium was studied by uniaxial tensile testing. One hundred forty-four tissue specimens were assessed: 96 sutured samples (48 in which a centrally located suture was placed at an angle of 90 degrees with respect to the longitudinal axis, whereas in the remaining 48, a centrally located suture was placed at a 45 degrees angle to the longitudinal axis, in sets of 12 samples each, sewn with sutures made of Gore-Tex, nylon, Prolene, or silk), and 48 unsutured controls. Each group of 24 samples sewn at one angle or the other with the different suture materials was assayed together with a corresponding control group of 12 unsutured samples. The mean tensile strengths in the unsutured controls ranged between 30.16 MPa and 43.42 MPa, whereas those of the sutured sets ranged from 14.68 MPa to 21.91 MPa. The latter presented a statistically significant loss of resistance (p < 0.01) when compared with the unsutured tissue samples. The angle of the suture with respect to the longitudinal axis influenced the degree of shear stress produced by the suture, as well as the behavior of the different suture materials used. The set of samples sewn with Prolene appeared to be that most sensitive to changes in the angle of the suture, whereas tissue sewn at a 45 degrees angle with Gore-Tex presented lower shear stress values in comparison with samples in which the other three materials were used. A method of tissue selection based on morphological and mechanical criteria was used to ensure the homogeneity of the results in such a way that the coefficients of determination (R2) for the stress/strain curve fitting equation ranged between 0.888 and 0.995. This excellent fit made it possible, applying regression analysis, to predict the mechanical behavior of a specimen by determining that of a contiguous tissue sample. Thus, it should be possible, at least theoretically, to characterize the behavior of a specific region or zone of the biomaterial. In conclusion, ostrich pericardium exhibits strong resistance to rupture, even when sutured. The selection method used ensures the homogeneity of the samples and, thus, of the results. The angle of the suture with respect to the longitudinal axis, where the load is centered, determines the shear stress produced by the suture and the mechanical behavior of each suture material.


Asunto(s)
Pericardio/lesiones , Suturas/efectos adversos , Animales , Materiales Biocompatibles , Fenómenos Biomecánicos , Modelos Lineales , Polipropilenos , Politetrafluoroetileno , Rotura , Estrés Mecánico , Struthioniformes , Técnicas de Sutura , Suturas/normas , Resistencia a la Tracción
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