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81.
An unusual congenital tracheal anomaly is described. Complete (closed) tracheal rings, occupying the entire length of the trachea, have seldom been reported. Most affected patients succumb to respiratory infections in early infancy. Diagnosis of this anomaly is difficult during life, but radiographic and endoscopic examinations may be revealing. There is no known definitive treatment, although the airway may be managed long enough for body growth to relieve the obstruction. This rare anomaly should be considered in those cases of intermittent respiratory obstruction that are not associated with other more common causes of stridor.  相似文献   
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A subclone of rat pituitary tumor cells, designated GH3/C14, was isolated from the parent population of GH3 pituitary cells and was estrogen-dependent for growth in vivo. GH3/C14 cells inoculated into host animals formed tumors in intact females, estrogen-treated ovariectomized females, and estrogen-treated males, but not in untreated intact or castrated males, or untreated ovariectomized females. Exogenous treatment with estrogens supported tumor formation in male animals. Radioimmunoassay of the average serum estradiol concentrations that support tumor growth in intact females, estradiol-treated intact females, and estradiol-treated intact males gave values of 41 +/- 4, 1,130 +/- 150, and 730 +/- 140 pg/ml, respectively. Tumor formation by GH3/C14 cells inoculated into male animals was not supported by either exogenous progesterone or hydrocortisone acetate. Further, these two steroid hormones had no significant effect on the estrogen-promoted growth in males or females. Exogenous testosterone treatment promoted tumor formation in males and ovariectomized females, but dihydrotestosterone was completely ineffective. Radioimmunoassay of the serum from tumor-bearing animals and the medium from the cells in culture showed that the cells produced growth hormone in vivo and in vitro but did not produce measurable amounts of luteinizing hormone or follicle-stimulating hormone. The groth of GH3/C14 cells in culture was examined in medium without added estrogen, and with estradiol added to the level of either the normal intact female rat or the estradiol-treated animals. No direct growth stimulation by estrogens could be detected in culture; the data suggested an indirect growth control mechanism.  相似文献   
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Peripheral blood basophils from normal human subjects responded chemotactically to the complement component C5a and also to the supernatant fluid from cultured human lymphocytes stimulated by mitogens or specific antigen. Basophil chemotactic factor (BCF) was detected in stimulated lymphocyte cultures within 24 hr and increased for the first 3 days. BCF was found after stimulation of lymphocytes by B or T cell mitogens as well as by specific antigen. The amount of BCF in culture fluids was independent of cell proliferation. Monocyte chemotactic factor (MCF) and BCF could not be separated from one another by Sephadex or DEAE chromatography. Both activities were eluted from Sephadex G-100 columns in a m.w. region of about 15,000 daltons and were found after ion exchange chromatography on DEAE in a peak eluted by 0.1 M NaCl. These findings suggest that mitogen or antigen-stimulated lymphocytes secrete a molecule that is chemotactic for both monocytes and basophils. Thus, in the absence of a basophil-specific chemotactic molecule, the preferential accumulation of basophils in certain types of delayed hypersensitivity skin reactions must be due to additional factors such as basophil chemotaxis augmentation factor.  相似文献   
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Streptomyces coelicolar A3(2) synthesizes a second antibiotic, in addition to the plasmid-determined methylenomycin A. It was identified, primarily on the evidence of mass spectroscopy of its diethyl ester, as actinorhodin, which has been described previously in other strains. It inhibited most Gram-positive bacteria tested, but only at a comparatively high concentration. Five independent mutations leading to lack of actinorhodin synthesis were located between cysD and strA on the chromosome.  相似文献   
89.
The reaction between 2-chloro-N-methylpyridinium iodide and bovine insulin at pH 8.5 afforded a trisubstituted derivative as main product. Following purification on DEAE-Sephadex A-25, this derivative crystallized from a citrate buffer in the form of large rhombohedra very similar to native insulin. This observation was confirmed by zero-layer X-ray precession photography. Amino acid analysis indicated substitution at the B1-terminus and on two of the four tyrosine residues. In the mouse convulsion assay the derivative showed no biological activity.  相似文献   
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Because of renewed interest in a possible connection between carnitine, lipid disorders, and myopathy, an automated method of analysis is desirable. Deproteinization of serum by use of membrane filter cones and automated assay with a bichromatic analyzer (the ABA-100) substantially increases efficiency without sacrificing the specificity and accuracy of the original manual enzymatic method. The described procedure allows for analysis of 80 speciments a day and is thus suitable for screening of selected populations. Normal values found in blood sera of adults were in the range of 25.0-73.8 mu mol/liter and the method has sufficient sensitivity to accurately measure concentrations as small as 10 mu mol/liter.  相似文献   
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