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991.
Post-traumatic axial malalignment of the lower limbs causes osteoarthrosis of the adjacent joints. Whether or not correction osteotomy is indicated depends upon the degree and the location of the deformity. Malalignment of the proximal femur should be corrected if the axis of the leg does not pass through the knee joint. If the axis is outside the central half of the tibial head, the indication for correction osteotomy is a relative one: varus deformities are more difficult to compensate and it is more urgent that these be corrected. Of 103 patients who underwent osteotomies of the proximal femur during the period 1973-1981, there were 73 in whom it was possible to follow up an average of 7 years after the realignment procedure. In nearly two-thirds of these patients the clinical symptoms noted before surgery had improved. In 10 cases of pseudarthrosis of the femoral neck, necrosis of the femoral head could not be avoided in spite of the surgical correction; nonetheless, the prognosis is better if the correction is done within the first 3 months after the trauma. 相似文献
992.
Metabolism of carcinogenic heterocyclic and aromatic amines by recombinant human cytochrome P450 enzymes 总被引:10,自引:4,他引:6
Hammons GJ; Milton D; Stepps K; Guengerich FP; Tukey RH; Kadlubar FF 《Carcinogenesis》1997,18(4):851-854
The N-hydroxylation of carcinogenic arylamines represents an initial step
in their metabolic activation. Animal studies have shown that this reaction
is catalyzed by the cytochrome P450 (P450) enzymes P450 1A1 and P450 1A2.
In this study, utilizing enzymes expressed in Escherichia coli (and
purified) or in human B-lymphoblastoid cells, the catalytic activities of
recombinant human P450 1A1, P450 1A2, and P450 3A4 for N- hydroxylation of
several carcinogenic arylamines were determined. P450 1A2 from both
expression systems catalyzed the N-hydroxylation of 4- aminobiphenyl and
the heterocyclic amines, 2-amino-3-methylimidazo[4,5- f/quinoline (IQ),
2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and
2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Rates were similar,
with values of 1.1-7.8 nmol/min/nmol P450. In contrast, P450 1A1 catalyzed
N-hydroxylation of only PhIP, and no activity was observed with P450 3A4.
Further kinetic analysis with purified P450 1A2 showed similar Km and Vmax
values for N-hydroxylation of the arylamines. Furafylline and fluvoxamine,
inhibitors of P450 1A2 activity in human liver microsomes, were found to be
inhibitory of the recombinant P450 1A2 N-hydroxylation activity. Results
from this study are supportive of a major role for human P450 1A2 in the
metabolic activation of arylamines.
相似文献
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994.
Cholangiocarcinoma complicating primary sclerosing cholangitis: cholangiographic appearances 总被引:1,自引:0,他引:1
MacCarty RL; LaRusso NF; May GR; Bender CE; Wiesner RH; King JE; Coffey RJ 《Radiology》1985,156(1):43-46
Cholangiograms from 104 patients (and serial cholangiograms in 66 patients) with primary sclerosing cholangitis (PSC) were reviewed. In 13 patients the additional diagnosis of cholangiocarcinoma was made at biopsy or autopsy. Cholangiograms from patients with both PSC and carcinoma were compared with cholangiograms from patients with PSC alone. Marked dilatation of ducts or ductal segments (100% vs. 24%) and the appearance of a polypoid mass (46% vs. 7%) were common findings in the group of patients whose disease was complicated by malignancy. In the malignant group, polypoid masses were larger, measuring 1 cm or greater in diameter. On serial cholangiograms, four of 15 patients with progressive stricture formation and four of five with progressive ductal dilatation proved to have carcinomas. The frequent occurrence of bile duct carcinoma as a complication of PSC in this group of patients indicates that PSC has a strong tendency to undergo malignant degeneration. Cholangiographic findings which suggest malignant degeneration include markedly dilated ducts or ductal segments, presence of a polypoid mass 1 cm or greater in diameter, and progressive stricture formation or ductal dilatation. 相似文献
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This case demonstrates the myelographic, CT myelographic, and MR appearance of primary lymphoma of the cauda equina. It also illustrates the utility of high-resolution CT myelography in certain lesions of the cauda equina. The authors feel that CT myelography, with its inherent ability to depict individual nerve roots and therefore any pathologic involvement as well, should be considered an adjunct to MR in imaging the cauda equina. 相似文献
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