RESUMEN
Individual motor endplates in the skeletal muscles of chickens genetically homozygous for muscular dystrophy have been compared with those in normal chickens. Measurements were made there, by specific autoradiographic techniques, of the numbers of total cholinesterase-like molecules and of acetylcholinesterase molecules. The acetylcholinesterase is distinctly decreased at the endplates in dystrophic muscles. The various data available on these muscles are compatible with the concept that a neural factor which determines the synaptic acetylcholinesterase, along with a number of other characters in the muscle cell, is defective in this disorder.
Asunto(s)
Acetilcolinesterasa/análisis , Distrofia Muscular Animal/enzimología , Unión Neuromuscular/enzimología , Animales , Autorradiografía , Pollos , Colinesterasas/análisis , Homocigoto , Distrofia Muscular Animal/genética , Isótopos de Fósforo , TritioRESUMEN
Management of obstructive uropathy diagnosed in utero would be markedly enhanced by the availability of a simple, safe and quantitative fetal renal function test to predict postnatal renal function. In order to allow experimental evaluation of such a parameter, we adjusted a model of complete urethral obstruction with urachal ligation in 30 fetal lambs at 79 or 99 days of gestation. The method described allows obstruction in male and female fetuses as early as 79 days of gestation, with an overall high survival rate (control: 12/14; obstructed: 23/29), although lower (6/12) when obstruction is performed early (79 days) during gestation. Consequences of obstruction were examined on the 121st day of gestation. Severe hydronephrosis, ureteral and calyceal dilatation, with or without ascites and pulmonary hypoplasia were observed in all fetuses; creatinine clearance determined in utero was decreased in both groups with obstruction (early and late) vs control group: 1.15 +/- 0.5, NS, and 0.58 +/- 0.4, p < 0.01 vs 1.61 +/- 0.8 ml/min/kg respectively. In both obstructed groups, fetuses with ascites displayed lower plasma creatinine concentration and higher creatinine clearance values when compared to fetuses without ascites. In conclusion, the experimental model of obstructive uropathy described appears efficient and easily reproducible, allowing therefore the evaluation of a predictive parameter of postnatal renal function. Our preliminary results suggest that renal fetal function is more dependent on the degree of obstruction than on the term of its creation.
Asunto(s)
Pruebas de Función Renal , Obstrucción Uretral/embriología , Animales , Creatinina/sangre , Modelos Animales de Enfermedad , Femenino , Edad Gestacional , Tasa de Filtración Glomerular/fisiología , Hidronefrosis/embriología , Hidronefrosis/fisiopatología , Masculino , Intercambio Materno-Fetal/fisiología , Embarazo , Ovinos , Obstrucción Uretral/fisiopatologíaRESUMEN
The most frequently used methods are discussed of small intestine transplantation (SIT) in experimental models. The advantages and drawbacks of various operational techniques are characterized. The problems are presented associated with the intensity of graft rejection reaction. The presently used methods of preservation of small intestine taken for transplantation are discussed.
Asunto(s)
Intestino Delgado/trasplante , Animales , Rechazo de Injerto , Conservación de Tejido/métodosRESUMEN
The basic immunological problems are discussed associated with small transplantation (SIT) in experimental models. The types of immunological reactions are characterized. The status is presented of studies on the used methods of immunosuppression and the decrease of immunogenicity of graft. The role is stressed of histological monitoring of graft rejection reaction.
Asunto(s)
Intestino Delgado/trasplante , Inmunología del Trasplante , Animales , Terapia de Inmunosupresión/métodos , Intestino Delgado/patologíaRESUMEN
Three stages in development of small bowel transplantation (SBT) in a human are discussed. Indications to SBT in adults and children are mentioned. Clinical experiences in SBT in humans with particular presentation of actual problems, difficulties and future of SBT are discussed.
Asunto(s)
Intestino Delgado/trasplante , Adulto , Niño , Femenino , HumanosRESUMEN
Seventy one patients with ectopic testis of age between 2 and 11.5 years were treated with human chorionic gonadotropin (HCG) at doses recommended by the International Health Foundation. The descent of testis to the scrotum was achieved in almost half of the treated boys (49.3%). The descent was successful mainly in cases of lower inguinal position of the undescended testicle, and only rarely when the testicle was situated higher. The descent was never successful in cases when the scrotum was small and underdeveloped.
Asunto(s)
Gonadotropina Coriónica/uso terapéutico , Criptorquidismo/tratamiento farmacológico , Factores de Edad , Niño , Preescolar , Gonadotropina Coriónica/administración & dosificación , Humanos , Masculino , Escroto/anomalíasRESUMEN
We have reinforced local superconductivity in ferromagnetic Fe(67)Cr(18)B(15) metallic glasses by ion irradiation. Superconductivity in this medium appears due to the presence of large-scale layered clusters of metallic Fe-Cr phase, 150-230 Å in size, with a ferromagnetic (or superparamagnetic) Fe-rich core and nonmagnetic Cr-rich superconducting shell. Here we show that due to the intensification of concentration phase separation in the Fe-Cr clusters under ion (Ar(+)) irradiation, the volume of the superconducting phase increases from the initial 0.4-0.5% up to 7-8%. After irradiation, the resistivity jump Δρ/ρ in the temperature range T=3.1-3.6 K increases â¼14 times, reaching 19%, as compared to 1.36% for the initial sample. In the interval of T=3.1-3.6 K, the rate of resistance change reaches 79% K(-1) for the irradiated sample instead of 3.6% K(-1) for the initial sample. In the same temperature interval, the rate of magnetoresistance change increases from 3% K(-1) for the initial sample up to 70% K(-1) after irradiation.
RESUMEN
Investigation of the conductivity mechanisms in ferromagnetic Fe(67)Cr(18)B(15) metallic glasses with clusterized structure reveals anomalies in the behaviour of resistance and magnetoresistance (MR) in a narrow temperature interval, T = 3.6-3.1 K. The anomalies are seen as a sharp decrease of the sample resistivity in this range, with a rate equal to 3.6% K(-1), i.e. 200-500 times more than the rate 0.008-0.021% K(-1) in the range of 300-4 K. MR in the same range increases with a rate 1000 times larger (4% K(-1) at T â¼ 3.1-3.6 K) than in the 300-4 K range (<0.0015% K(-1)). We explain this result by the appearance of local superconductivity in the large-scale layered clusters of metallic Fe-Cr phase, 150-200 Å in size, with ferromagnetic Fe(2)Cr core and nonmagnetic FeCr(2) superconducting shell. The superconducting phase, which occupies 0.4-0.5% of the sample volume, provides a resistance jump Δρ/ρ≈1.5% that corresponds to calculation. The superconducting state of the clusters collapses if the magnetic field exceeds 20 kOe.
Asunto(s)
Potenciales de Acción/efectos de los fármacos , Unión Neuromuscular/fisiología , Receptores Colinérgicos/efectos de los fármacos , Acetilación , Animales , Autorradiografía , Sitios de Unión , Bungarotoxinas/farmacología , Depresión Química , Estimulación Eléctrica , Técnicas In Vitro , Cinética , Masculino , Potenciales de la Membrana/efectos de los fármacos , Microelectrodos , Músculos/fisiología , Unión Neuromuscular/efectos de los fármacos , Ratas , Factores de Tiempo , TritioAsunto(s)
Intestino Delgado/trasplante , Adulto , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
A pilot home care program for lung disease patients has been set up by a lung association, in conjunction with local hospitals and home care agencies. The emphasis is on long-term care and support of services for which home care agencies would not ordinarily be reimbursed.