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991.
The Spemann organizer induces neural tissue, dorsalizes mesoderm and generates a second dorsal axis. We report the isolation and characterization of Smad10, which has all three of these Spemann activities. Smad10 is expressed at the appropriate time to transduce Spemann signals endogenously. Like the organizer, Smad10 generates anterior and posterior neural tissues. Smad10 appears to function downstream of the Spemann organizer, consistent with a role in mediating organizer-derived signals. Interestingly, Smad10, unlike previously characterized mediators of Spemann activity, does not appear to block BMP signals. This finding, coupled with the functional activity and expression profile, suggests that Smad10 mediates Spemann action in a novel manner.  相似文献   
992.
Developmental changes in relative amounts of peripheral nerve proteins and glycoproteins have been correlated with the degree of morphological myelination at various ages during the first 25 postnatal days in rat sciatic nerve. At birth there is virtually no major myelin glycoprotein (P0), but there is a protein which migrates to the same point on sodium dodecyl sulphate (SDS) polyacrylamide gels as the small myelin basic protein (P2). During the time myelin is being formed in the nerve, the P0 protein increases and the P2 protein appears to decrease in relative amount in the nerve. The accumulation of P0 protein in the nerve correlates extremely well with the degree of myelination in sciatic nerve. At 4-6 days postnatal, smooth membrane profiles are observed which are located within axons and in the inner Schwann cell cytoplasm. Such profiles are also observed to fuse with the axolemma-Schwann cell interface. The profiles may represent membrane material being added to or deleted from the axolemma or myelin during myelination.  相似文献   
993.
In a series of 1334 consecutive pneumoencephalographies in children 0-15 years, there were 2 deaths, 3 severe apneas and 1 pneumomediastinum. Respiratory insufficiency, due to contention of the patient with resulting impairment of the motion of thoracic muscles was an important mechanism and pneumoencephalography is contra-indicated in children with respiratory difficulties prior to the examination. In 90 consecutive patients submitted to pneymoencephalography CSF changes and fundus oculi abnormalities were studied prospectively. Aseptic meningitis of a mild degree is common following the examination, whereas significant meningeal haemorrhage is rare. Haemorrhages in the fundi were noted in 10% of the patients. The general tolerance of the examination was good.  相似文献   
994.
995.
The effects of combined high pressure (300 and 400 MPa) and low temperature (50°C) treatments on the microbial contamination of duck foie gras samples were compared with those of classical thermal pasteurization (85°C at the coldest point). A multilayer packaging film (PE/PA/PE) was selected from two films commonly used for these types of food, by preliminary tests showing its ability to limit microbiological development in such samples. In each experiment, microbiological contamination was analysed on treated and untreated samples, and results were systematically compared with those obtained from a classically pasteurized sample of the same liver. A pasteurization type effect (drastic reduction of vegetative mesophilic and psychrophilic contaminations, destruction of coliforms and of Staphylococcus aureus ) was obtained at this temperature with samples pressurized at 400 MPa for at least 10 min.  相似文献   
996.
The dexamethasone-modified adrenal scintiscan, a noninvasive procedure, is described for the preoperative distinction between primary aldosteronism (aldosterone-producing ademona) and idiopathic aldosteronism (bilateral hyperplasia) and for the preoperative localization of aldostersone-producing adenomas. This procedure has been carried out on 17 subsequently proved cases of primary aldosteronism and nine cases (four unexplored) of idiopathic aldosteronism. In the tumor cases, it indicated correctly the side of the tumor in 88 per cent. It was correct in predicting the existence of bilateral hyperplasia in all of the five cases explored. It produced the same response in four more cases believed to have bilateral hyperplasia, in which surgical exploration has not been carried out. Many of the same patients had, in addition, standard adrenal scintiscans (SS), adrenal venography, and determinations of aldosterone in adrenal venous blood. These results are compared with those of the dexamethasone scintiscan (DS). In tumor localization, the 88 per cent figure for the DS was only moderately better than that of the other three (71 per cent, SS; 80 per cent, venography; 80 per cent, adrenal venous aldosterone levels). However, in predicting bilateral hyperplasia, the DS was 100 per cent correct, as were the levels of aldosterone in adrenal venous blood. The SS and adrenal venography failed in bilateral hyperplasia and gave many false-positive results indicating tumor. The DS, a relatively simple outpatient procedure, appears to be at least as effective, both in lateralizing tumors and distinguishing between tumor and bilateral hyperplasia, as the more difficult, expensive, and sometimes hazardous invasive procedure of bilateral adrenal vein catheterization.  相似文献   
997.
Human platelets survival curves make it possible to estimate two factors which could be held responsible for the disappearance of cells: a) random destruction b) ageing of the platelets. This study was devoted to non-thrombocytopenic patients with chronic vascular disease. In 40% of the cases, the platelet destruction was found to be due to normal ageing of the cells combined with a random destruction process. The estimation of both of these parameters is of interest for the clinical survey of these patients. The statistical analysis of the remaining 60% of the cases presented here has demonstrated a pure linear disappearance of the labelled platelets. This obsveration favours ageing as the cause of the destruction of the platelets.  相似文献   
998.
Ten patients with patent urethral duplication are presented. Nine patients had two independent patient channels originating from the bladder or the posterior urethra. Both voiding cystourethro and retrograde urethrography are necessary to completely evaluate this anomaly. In each instance the ventral channel, regardless of the position of its meatus, proved to be the more functional urethra. In those patients whose dorsal channel was in an epispadiac position, the symphysis pubis was abnormally wide. A functionally and anatomically accurate classification is proposed, and the embryology of these anomalies is discussed.  相似文献   
999.
1000.
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