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A soluble TMV replicase (TMV-RNA dependent RNA polymerase) has been partially purified from systemically TMV-infected tobacco leaves. The enzyme was obtained by gel filtration on 8% agarose followed by affinity chromatography on agarose with chemically coupled RNA. The presence of Mg2+, all four nucleoside triphosphates, and an RNA were absolutely required for enzyme activity with the purified replicase, which showed some preference for the homologous viral RNA. The product was largely resistant to ribonuclease at high salt concentration. Based on the sedimentation in sucrose gradients, the molecular weight of the replicase was estimated to be 130,000.  相似文献   
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Y chromosome variation has been studied in three groups of Norwegian males: 35 boys from an adolescent psychiatric hospital; 45 men from a hospital for hard-to-manage or dangerous, psychotic men; and 26 boys from two ordinary school classes.
Y chromosomes with 1, 2, and 3 brightly fluorescing bands were found in all three groups. One boy carried a Y with no bands. The mean values of the Yf/Yq ratio were not significantly different in the three groups (Yf is the length of the distal, brightly fluorescing part of Yq). Two cases of XY/XYY mosaicism were found among the psychotic men.
The study shows that the human species is polymorphic with regard to the size of the Y chromosome, i. e. the number of fluorescent bands in the long arm. No phenotypical manifestation of this polymorphism, particuIarly as regards behaviour, was found.  相似文献   
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Hormone-independent growth and invasiveness represent phenotypic properties acquired during early progression of breast cancer. We compared human mammary adenocarcinoma cells, MCF-7, which are estrogen-dependent and poorly metastatic, with the estrogen-independent and highly metastatic subline, MCF7/LCC1, with regard to expression of tissue-degrading factors of the matrix metalloproteinase (MMP)-and urokinase (uPA)-dependent degradative pathways, as well as for their in vitro invasive properties. Both cell lines showed low constitutive mRNA expression of the MMP inhibitor TIMP-1. Baseline expression of TIMP-2 mRNA was also very low in MCF-7 cells, whereas the MCF7/LCC1 level was much higher (~10- fold). Furthermore, both cell lines revealed low constitutive capacity to migrate in an in vitro invasion assay. Treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA; 100 nM) induced the mRNAs for TIMP-1 as well as for MMP-1, MMP-9, the uPA receptor, and the uPA inhibitor PAI-1, am ongst which only the responses of MMP-9 and PAI-1 were cell-specific. The mRNA levels of MMP-9 and PAI-1 were ~10-fold and ~15-fold higher in MCF7/LCC1 cells compared to MCF-7 cells. The secretion of immuno-reactive PAI-1 was considerably elevated (. 20-fold) in TPA-treated MCF7/LCC1 cells, whereas the TPA-dependent level of 92-kDa MMP-9 was only ~2-fold higher in MCF7/LCC1 cells than in MCF-7 cells. In both cell lines treatment with TPA was associated with an increase (~10-fold) in in vitro migration, which in the MCF7/LCC1 cells was significantly attenuated by a reconstituted basement membrane extract (Matrigel). These data suggest that TPA-responsive in vitro invasive properties that are probably associ-ated with PAI-1 expression may co-vary with progression from hormone-dependent to -independent breast cancer. © Rapid Science 1998  相似文献   
15.
The purpose of the present study was to improve the quality and the effectiveness of subgingival scaling managed by dental students. A training program was developed and the scaling was performed in jaw models. The teeth of these models were modified in order to ensure a quick inspection of the scaled root surfaces. Artificial "calculus", consisting of a mixture of shellac, umbra, pumice and plaster dissolved in ethanol, was painted on the root surfaces. Following the completion of the scaling test, remaining "calculus" was evaluated by adoption of a grading system. This system had scores from 0 to 3 and was defined by illustrated and described criteria. A menu-directed computer program was developed in order to ensure a rapid transformation of surface scores into clinically-related variables. The output from this program gave valuable information about the proficiency of individual students, as well as about the whole class of students as one body. Other advantages and potentials of this system are described.  相似文献   
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In 54 cases of ruptured medial semilunar cartilages of the knee joint the bone mineral mass in the distal end of the femur was measured 0–5 years following removal of the injured cartilage. The bone mineral mass was significantly decreased. There was no tendency of restoration of the bone mass with time.Financial support was obtained from the Swedish Medical Research Council No: K69-23X-2737-01 and from the Gustav V 80: th Anniversary Foundation.  相似文献   
18.
A retrospective review is presented of 1353 consecutivepatients with histopathologically confirmed invasive breast carcinoma treatedradically with curative intent during the decade 1980–89.None had received adjuvant systemic therapy with hormonesor prolonged chemotherapy. The distribution of lymph-node negative(N–) and lymph-node positive (N+) patients was 75%and 25%, respectively.The treatment and outcome were analysed as regardsconventional prognostic parameters, in particular considering the axillarylymph-node status and the responsible hospital category (GeneralMunicipal Hospitals (MH)) versus Comprehensive Cancer Center (CC)).The most striking difference was detected as regardsthe number of examined lymph nodes. The mediannumber of nodes described at the MH was7, as compared to 14 at the CC(p < 0.001). In patients with pT1 tumoursthe highest rate of lymph-node positivity was observedwhen 10 or more axillary nodes were removed.Adjuvant radiotherapy reduced the loco-regional recurrence rate inthe N– patients, whereas only the regional recurrenceswere reduced among the N+ patients. The five-and 10-year tumor-related survival rates were 86% and76%, respectively, with no difference between the MHand the CC.As life-prolonging adjuvant hormone therapy and chemotherapy isnow available for patients with axillary lymph nodemetastases, it is important that patients with breastcancer are operated adequately with the aim toremove at least 10 axillary lymph nodes. Athorough examination of the axillary content should beperformed by the pathologist, and the number ofresected lymph nodes and metastases should be reported.The establishment of nation-wide standard criteria for themanagement of breast cancer is recommended.  相似文献   
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Background The anti-inflammatory drug etanercept may be an effective therapeutic agent in diabetic retinopathy. In order to further evaluate its potential, the pharmacokinetics and safety of this drug after intravitreal delivery were investigated.Methods After intravitreal administration of etanercept in rabbits, clinical examination, electroretinography (ERG), visually evoked potentials (VEP) and histology were evaluated. The pharmacokinetics and distribution of etanercept were analyzed using fluorescence-coupled protein at 0, 2, 4, and 8 weeks after injection in vitreous, retina, and choroid.Results No adverse effects and signs of toxicity were found. Etanercept showed peak concentrations after 4 weeks in the retina and choroid.Conclusions Intravitreally delivered etanercept is safe and results in high concentrations in the retina and choroid over a long period of time.  相似文献   
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