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991.
The RNase mismatch cleavage method was examined for its efficiency of indicating single-base sequence differences in the capsid protein-coding regions of different foot-and-mouth disease virus subtype O1 strains. The method was found suitable for indicating such differences. RNase A as well as RNase T1 contributed to substrate conversion. Examples for the cleavage of eleven different single-base mismatches in RNA double-strands are now known. All virus genomes found to differ from each other exhibited three or more non-neighboured single-base sequence differences. Other genomes found to be indistinguishable by this method were those of a recent field isolate adapted to cell culture, and those of a vaccine production strain; its progeny was transmitted to pig and cow and then analyzed. The results suggest that host change does not necessarily select for antigenic variant virus, and that virus submitted to some kind of selection pressure is changed at more than one position.  相似文献   
992.
Fragile Corners     
Haight  Richard O. 《JAMA》2003,289(12):1477
  相似文献   
993.
Localized 1H NMR spectra of glutamate in the human brain.   总被引:2,自引:0,他引:2  
Localized 1H NMR spectra at TE = 12 ms were obtained from cerebral cortex of human subjects using ISIS with surface suppression. The 2.29-ppm resonance was assigned to C4 glutamate with contributions from C4 glutamine and GABA using in vivo spectral editing and comparison of chemical shift with pure compounds. The measured intensity ratio between the 2.29 resonance and the creatine resonance at 3.03 ppm was in good agreement with the ratio predicted from previously reported measurements of glutamate, glutamine, and GABA concentrations in biopsied human brain tissue.  相似文献   
994.
OBJECTIVE: This study analyzed the incidence and timing of biliary tract complications after orthotopic liver transplantation (OLTx) in 1792 consecutive patients. These results were then compared with those of previously reported series. Finally, recommendations were made on appropriate management strategies. SUMMARY BACKGROUND DATA: Technical complications after OLTx have a significant impact on patient and graft survival. One of the principal technical advances has been the standardization of techniques for biliary reconstruction. Nonetheless, biliary complications still occur. A 1983 report from the University of Pittsburgh reported biliary complications in 19% of all transplants, and an update in 1987 reported biliary complications in 13.2% of transplants. METHODS: The medical records of all patients who underwent liver transplantation and were hospitalized between January 1, 1988 and July 31, 1991 were reviewed. The case material consisted of the medical records of 217 patients treated for 245 biliary complications. RESULTS: Primary biliary continuity was established by either choledochocholedochostomy over a T-tube (C-C, n = 129) or a Roux-en-Y choledochojejunostomy with an internal stent (C-RY, n = 85). The overall incidence for biliary complication in this large series was 11.5%. Strictures (n = 93) and bile leak (n = 58) were the most common complications (69.6%). Most biliary complications (n = 143, 66%) occurred within the first 3 months after surgery. In general, leaks occurred early, and strictures developed later. Bile leaks were equally frequent in both C-C and C-RY (27.1% and 25.9%, respectively); strictures were more common after a C-RY type of reconstruction (36.4% and 52.9%, respectively). Twenty-one patients died, an incidence of 9.6%. Fifteen of the 21 biliary-related deaths were among patients treated for rejection before the recognition of biliary tract pathologic findings. CONCLUSIONS: Progress has been made on improving the results of biliary reconstruction after OLTx. Nonetheless, patients continue to experience biliary complications after OLTx, and these complications cause considerable loss of grafts and life. If significant additional improvement in patient and graft survival are to be obtained, the technical performance of OLTx must continue to improve.  相似文献   
995.
Atherosclerotic renovascular disease (ARD) is an increasinglyimportant cause of renal failure. However, important featuresof the clinical presentation are not fully described, and theoutcome after intervention by angioplasty remains controversial.Ninety-four patients with ARD diagnosed at angiography werereviewed. Twenty-four patients were diabetic. Thirty-nine patientshad unilateral renal artery stenosis or occlusion (group A),28 had bilateral stenosis (group B), and 27 had unilateral occlusionplus contralateral occlusion or stenosis (group C), Two yearsafter presentation, actuarial patient survival was 96%, 74.3%and 47.1% in groups A, B and C, respectively (p<0.001 forall differences); actuarial renal survival in surviving patientswas 97.3%, 82.4% and 44.7%, respectively (p<0.001 for alldifferences). Percutaneous transluminal balloon angioplasty(PCTA) was performed in 74 patients. Renal function improvedin only a minority of cases, but was stable in 73% of nondiabeticpatients 12 months after PCTA. Angioplasty was less effectivein diabetic subjects, with only 53.3% having stable renal functionat 12 months follow-up. Renal and patient survival were stronglyrelated to the initial angiographic findings. In nondiabeticsubjects, PCTA resulted in stabilization of renal function forat least one year in nearly threequarters of cases, which suggestsa benefit from intervention in this disease whose natural historyis otherwise of progression.  相似文献   
996.
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed.  相似文献   
997.
The results of treatment of 107 young and middle aged sufferers with mild craniocerebral trauma have been analysed. The regimen for use of hyperbaric oxygenation contributing to normalization of general cerebral, focal disorders in high nervous and psychic activity, prevention of certain posttraumatic complications has been developed.  相似文献   
998.
The authors report on 14 patients with epidermoid carcinoma of the glottic region, classified T1, T2 and T3, operated upon by a hemilaryngectomy (9 cases) with reconstruction using a Plathysma myocutaneous flap. The oncological results over a follow-up period of 1 to 6 years and the functional results are analyzed. The authors conclude that this method does not compromise the carcinological result and provides a good functional result with low ratings for complications, with in addition an adequate support for the organ, favouring increased resections.  相似文献   
999.
A prospective study of school girls in a mixed Nigerian population revealed that the mean menarcheal age was 13.98 +/- 1.30 years. The mean menarcheal age was influenced by the social class of the parents, being higher in the lower social class, there were considerable variations in the biologic measurements (height, weight and body mass index) among girls who attained menarche.  相似文献   
1000.
Assessment of attitudes amongst health care professionals to suicide prevention reveals a considerable degree of doubt with regards to its feasibility and appropriateness. The various professional groups may vary considerably in the degree of negative attitudes which they exhibit. Such findings suggest that there is an urgent need to ensure that health care professionals are fully informed about the key facts concerning suicide and preventive strategies. Key elements of clinical practice and service organization with regards to suicide prevention are discussed.  相似文献   
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