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101.
The changes in chromaticities were measured, in a dark-adapted state, when monochromatic lights were moved from the fovea to 2.5° and 7.5° temporally. In order to analyze the contributions of the rod and cone mechanisms to these changes, the chromaticities were measured during dark adaptation following high light adaptation. For several min during the cone-plateau period, the colourmixture functions remained invariant and the outlines of the test field appeared distinct and clearcut. Just prior to the cone-rod break of the dark-adaptation curve, however, the chromaticities generally started to change and the shape of the test field became somewhat blurred. The evidence is judged to indicate that the chromaticities measured during the period of invariance are due to pure cone activity, while the shift in chromaticities measured during the further stay in the dark is due to the effect of rod intrusion. 相似文献
102.
Pseudomonas aeruginosa exoenzyme S: an adenosine diphosphate ribosyltransferase distinct from toxin A. 总被引:37,自引:3,他引:34 下载免费PDF全文
B H Iglewski J Sadoff M J Bjorn E S Maxwell 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(7):3211-3215
Pseudomonas aeruginosa exoenzyme S is an adenosine diphosphate ribosyltransferase distinct from Pseudomonas toxin A. Exoenzyme S catalyzes the transfer of radioactivity from all portions of radiolabeled NAD+ except nicotinamide. Digestion of the radiolabeled product(s) formed in the presence of [adenine-14C]NAD+ and exoenzyme S with snake venom phosphodiesterase yields only AMP, suggesting that ADP-ribose is present as monomers and not as poly(ADP-ribose). Exoenzyme S does not catalyze the transfer of ADP-ribose from NAD+ to elongation factor 2, as do toxin A and diphtheria toxin, but to one or more other proteins present in crude extracts of wheat germ or rabbit reticulocytes and in partially purified preparations of elongation factor I. The ADP-ribosyltransferase activity of exoenzyme S is distinct from toxin A by several tests: it is not neutralized by toxin A antibody, it is destroyed rather than potentiated by pretreatment with urea, and it is more heat stable. These latter observations and the substrate specificity suggest that exoenzyme S is different from any previously described prokaryotic ADP-ribosyltransferase. 相似文献
103.
Hultling Claes; Rosenlund Bjorn; Tornblom Magnus; Sjoblom Peter; Garoff Leena; Nyman Claes; Hillensjo Torbjorn 《Human reproduction (Oxford, England)》1995,10(4):847-850
Treatment of non-seminomatous testicular cancer often leadsto infertility due to anejaculation/retrograde ejaculation andpoor sperm quality. In these men spermatozoa may be obtainedby transrectal electroejaculation (TE), but the optimal strategyfor assisted procreation in these couples is not known. Ouraim was to examine whether TE and conventional in-vitro fertilization(IVF) would be successful. A total of 10 couples, with long-standinginfertility due to anejaculation or retrograde ejaculation aftertreatment for testicular cancer 514 years earlier, werereferred to our unit. All men underwent diagnostic TE undergeneral anaesthesia. Spermatozoa were recovered in nine cases.The antegrade fraction was prepared and used for IVF. Spermquality was variable and conventional IVF was considered impossiblein three cases. Altogether six IVF treatment cycles in six couplesresulted in five pregnancies, of which four resulted in a deliveryand one resulted in a spontaneous abortion. One additional pregnancyis ongoing after transfer of cryopreserved embryos. The fertilizationrate was 54% (33/61) and the cleavage rate was 97% (32/33).No complications relating to the procedure have been encountered. 相似文献
104.
Evaluation of monoclonal antibodies for the development of breast cancer immunotoxins 总被引:5,自引:0,他引:5
Eighty-five antibodies recognizing breast cancer-selective antigens were conjugated to ricin toxin A-chain using a disulfide linkage. The cytotoxicities of the resulting immunotoxins were determined on breast cancer cells and normal human fibroblasts. Twenty-four antibodies formed immunotoxins that were toxic to at least one breast cancer cell line at concentrations of 10 nM or less but were nontoxic to human fibroblast lines used as negative controls. Some of the breast tumor-selective immunotoxins were as toxic as a conjugate between monoclonal anti-transferrin receptor and ricin toxin A-chain (50% inhibition of cellular protein synthesis at approximately 0.1 nM). Another set of four immunotoxins were indiscriminately toxic to human breast tumor cell lines, two human fibroblast cell lines, and a human lymphoblastoid line. Several of the antibodies the toxin conjugates of which specifically killed breast cancer cell lines may be useful in cancer therapy, since they show a wide range of binding to individual breast tumors and cell lines and a limited range of binding to normal tissue types. 相似文献
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OBJECTIVES: In muscle-invasive bladder cancer, the risk of developing a urethral recurrence after cystectomy varies between 4% and 18%, especially when an ileal conduit is performed. For this reason, some authors advocate a urethrectomy in these indications. At our center, we developed the technique of prepubic urethrectomy. We assessed the feasibility and implications of this technique over 20 yr of use. PATIENTS AND METHODS: We retrospectively analyzed the medical files of 180 consecutive male patients who underwent a urethrectomy simultaneously with cystectomy for invasive bladder cancer between 1985 and 2005. We describe our technique step-by-step, and present possible technical difficulties and complications of urethrectomy. RESULTS: The mean increase in operative time with the prepubic urethrectomy over cystoprostatectomy alone was 17min (range: 15-25). Postoperative complications occurred in 10 (5.5%) patients. A subcutaneous penile haematoma was noted in four (2.2%) patients, two of whom needed a circumcision later on. A scrotal haematoma was seen in five (2.7%) patients; two needed a surgical drainage and three were treated conservatively. A prepubic collection was noted in one patient who was also treated conservatively. No thromboembolic or neurologic complications were encountered. CONCLUSIONS: When a urethrectomy is indicated, it can best be performed by using the prepubic approach, because it is easier and less time-consuming than the perineal approach, and has very limited and easily manageable complications. 相似文献