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171.
Effect of pressure on the refractive index of Ge and GaAs 总被引:1,自引:0,他引:1
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RP Abratt GL McAdam AR Pontin RD Barnes HS Ball 《Canadian Metallurgical Quarterly》1997,35(4):203-5; discussion 205-6
To evaluate the efficacy and toxicity of primary chemotherapy in patients with stage 2 (retroperitoneal lymph node metastases) testis cancer, 20 consecutive patients referred to Groote Schuur Hospital between September 1992 and March 1994 were reviewed. There were 10 patients with non-bulky non-seminomatous germ cell tumour (NSGCT), 5 with bulky NSGCT and 5 with bulky seminoma. The treatment regimen consisted initially of 4 cycles of cisplatin, etoposide and bleomycin. Patients with NSGCT and a residual mass after chemotherapy subsequently underwent retroperitoneal lymph node dissection (RPLND) and those with seminoma underwent a low dose of irradiation to the mass. In 7 (70%) of the 10 patients with non-bulky NSGCT, there was a complete response to chemotherapy and 3 patients underwent limited RPLND. One patient relapsed at follow-up but remains clear of disease after salvage therapy. The survival rate is 100% at a median follow-up of 60 months (range 12-143 months). In 5 patients with bulky NSGCT there was no complete response to chemotherapy. Three have undergone limited RPLND. The survival rate is 52% at a median follow-up of 130 months (range 108-152 months). In 5 patients with bulky seminomas, the survival rate is 100% at a median follow-up of 55 months (range 29-92 months). Toxicity has been modest except for 1 patient who died postoperatively in the early part of the study. Four patients have fathered children after treatment. We conclude that primary chemotherapy is the treatment of choice for patients with stage 2 testis cancer. 相似文献
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Complete ruptures of the distal hamstring tendons rarely cause functional disability significant enough to warrant surgical intervention. Isolated ruptures of the distal semimembranosus tendon complex have not been reported previously in the literature. A case of a complete rupture of the distal semimembranosus tendon complex occurring in a professional football player with resultant functional disability is reported here. The magnetic resonance imaging scan was essential for an accurate diagnosis. Subsequent surgical repair and postoperative rehabilitation is described. Strict attention to recreating the multiple attachments of the semimembranosus tendon complex is recommended. 相似文献
176.
T Yoshikawa G Turner LE Esterling AR Sanders SD Detera-Wadleigh 《Canadian Metallurgical Quarterly》1997,2(5):393-397
Cerebral intraparenchymal cysts without communication with the ventricles are very rare. We report four such cases with no relevant past history or evidence of infection, haemorrhage, trauma, tumour or congenital neural tube defect. At operation smooth wailed cysts with an ependymal-type lining were found. To the best of our knowledge, we present the first correlation of their pathological and radiological features (including magnetic resonance imaging). We also review the literature on these cysts. 相似文献
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GL Burke DE Bild JE Hilner AR Folsom LE Wagenknecht S Sidney 《Canadian Metallurgical Quarterly》1996,1(4):327-335
Copper/zinc (Cu/ZnSOD) and manganese (MnSOD) superoxide dismutases which catalyze the dismutation of toxic superoxide anion, O(2-)-, to O2 and H2O2, play a major role in protecting cells from toxicity of oxidative stress. However, cells overexpressing either form of the enzyme show signs of toxicity, suggesting that too much SOD may be injurious to the cell. To elucidate the possible mechanism of this cytotoxicity, the effect of SOD on DNA and RNA strand scission was studied. High purity preparations of Cu/ZnSOD and MnSOD were tested in an in vitro assay in which DNA cleavage was measured by conversion of phage phi X174 supercoiled double-stranded DNA to open circular and linear forms. Both types of SOD were able to induce DNA strand scission generating single- and double-strand breaks in a process that required oxygen and the presence of fully active enzyme. The DNA strand scission could be prevented by specific anti-SOD antibodies added directly or used for immunodepletion of SOD. Requirement for oxygen and the effect of Fe(II) and Fe(III) ions suggest that cleavage of DNA may be in part mediated by hydroxyl radicals formed in Fenton-type reactions where enzyme-bound transition metals serve as a catalyst by first being reduced by superoxide and then oxidized by H2O2. Another mechanism was probably operative in this system, since in the presence of magnesium DNA cleavage by SOD was oxygen independent and not affected by sodium cyanide. It is postulated that SOD, by having a similar structure to the active center of zinc-containing nucleases, is capable of exhibiting non-specific nuclease activity causing hydrolysis of the phosphodiester bonds of DNA and RNA. Both types of SOD were shown to effectively cleave RNA. These findings may help explain the origin of pathology of certain hereditary diseases genetically linked to Cu/ZnSOD gene. 相似文献
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PURPOSE: To construct tissue-specific cDNA libraries containing copies of genes of ion transporting and receptor proteins in lens and cornea epithelia. To screen the libraries for the cDNA of these molecules and to deduce the protein sequence from the cDNA sequence. METHOD: Lens and corneal cDNA libraries are not commercially available and are difficult to prepare from microdissected single animal eyes or cadaver human eyes due to the small amount of tissue. To overcome these problems, we refined an approach for preparing high efficiency, non-PCR amplified plasmid cDNA libraries, where only nanogram quantities of poly (A) RNA are required. Plasmids were electrotransformed into DH10B bacteria and routinely yielded >10(6) independent colonies with typically >90% recombinants. Randomly selected colonies were subjected to colony PCR analysis to determine the libraries average insert size (typically approximately 1-kb). Primers to known genes were used in PCR amplification to check for representation of the genes in the cDNA libraries. RESULTS: Using libraries from rabbit cornea epithelium and endothelium, cultured human lens epithelium, and alphaTN4 cells, we have found the libraries to contain the cDNA for 3 common housekeeping proteins expected to be at high copy numbers in all cells. In addition, we identified 22 rare proteins and for many we determined the complete coding regions. These include K+ channels, Cl- channels, Ca++ channels, Na+ channels, three exchangers, the Na+-HCO3- cotransporter, and three kinds of receptors. CONCLUSION: Cornea and lens libraries have been constructed from single cornea or lens preparations. The libraries often contain the cDNA sequences for ion transporting and receptor proteins which are expected to be relatively rare in these cells. Many of these cDNA's have now been sequenced and the encoded proteins identified. 相似文献