924 resultados para Restriction ring


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BACKGROUND: The objective of this study was to compare cycle control, cycle-related characteristics and bodyweight effects of NuvaRing with those of a combined oral contraceptive (COC) containing 30 microg of ethinyl estradiol and 3 mg of drospirenone. METHODS: A randomized, multicentre, open-label trial in which 983 women were treated (intent-to-treat population) with NuvaRing or the COC for 13 cycles. RESULTS: Breakthrough bleeding or spotting during cycles 2-13 was in general less frequent with NuvaRing than that with the COC (4.7-10.4%) and showed a statistically significant odds ratio of 0.61 (95% confidence interval: 0.46, 0.80) with longitudinal analysis. Intended bleeding was significantly better for all cycles with NuvaRing (55.2-68.5%) than that with the COC (35.6-56.6%) (P < 0.01). Changes from baseline in mean bodyweight and body composition parameters were relatively small for both groups with no notable between-group differences. CONCLUSION: NuvaRing was associated with better cycle control than the COC, and there was no clinically relevant difference between the two groups in bodyweight.

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Total hip arthroplasty (THA) still carries a higher failure rate in patients with avascular necrosis of the femoral head (AVN) than in a similar patient population with THA for other reasons. This is particularly true for the acetabular component. One of the major factors accounting for this is the compromised acetabular bone quality with structural defects subsequent to collapsing of the femoral head in high-grade AVN. In this study we implanted an acetabular reinforcement ring with hook (ARRH), which had been used successfully for other indications with acetabular bone stock deficiency, in 32 consecutive THA's in 29 patients with AVN. Five patients died during the observation period of causes unrelated to the surgery, one patient was lost to follow-up and one patient could not be followed up due to chronic illness, leaving 25 hips (23 patients) with a minimum follow-up of ten years (mean: 11.8; range: 10-15). The mean Merle d'Aubigne score increased significantly from 7.7 preoperatively to 16.6 postoperatively (p < 0.001). One revision was performed for aseptic stem loosening. Of the unrevised hips, one acetabular component was classified as definitively loose. The cumulative 12-year survivorship for THA with ARRH in AVN was 95.2% (confidence interval: 86.1-100%) for both components, 100% for the cup and 95.2% for the stem (86.1-100%).

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The synthesis, biological testing, and NMR studies of several analogues of H-c[Cys (3)-Phe (6)-Phe (7)-DTrp (8)-Lys (9)-Thr (10)-Phe (11)-Cys (14)]-OH (ODT-8, a pan-somatostatin analogue, 1) have been performed to assess the effect of changing the stereochemistry and the number of atoms in the disulfide bridge on binding affinity. Cysteine at positions 3 and/or 14 (somatostatin numbering) were/was substituted with d-cysteine, norcysteine, D-norcysteine, homocysteine, and/or D-homocysteine. The 3D structure analysis of selected partially selective, bioactive analogues (3, 18, 19, and 21) was carried out in dimethylsulfoxide. Interestingly and not unexpectedly, the 3D structures of these analogues comprised the pharmacophore for which the analogues had the highest binding affinities (i.e., sst 4 in all cases).

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H-DPhe (2)-c[Cys (3)-Phe (7)-DTrp (8)-Lys (9)-Thr (10)-Cys (14)]-Thr (15)-NH2 (1) (a somatostatin agonist, SRIF numbering) and H-Cpa (2)-c[DCys (3)-Tyr (7)-DTrp (8)-Lys (9)-Thr (10)-Cys (14)]-Nal (15)-NH2 (4) (a somatostatin antagonist) are based on the structure of octreotide that binds to three somatostatin receptor subtypes (sst 2/3/5) with significant binding affinity. Analogues of 1 and 4 were synthesized with norcysteine (Ncy), homocysteine (Hcy), or D-homocysteine (DHcy) at positions 3 and/or 14. Introducing Ncy at positions 3 and 14 constrained the backbone flexibility, resulting in loss of binding affinity at all sst s. The introduction of Hcy at positions 3 and 14 improved selectivity for sst 2 as a result of significant loss of binding affinity at the other sst s. Substitution by DHcy at position 3 in the antagonist scaffold (5), on the other hand, resulted in a significant loss of binding affinity at sst 2 and sst 3 as compared to the different affinities of the parent compound (4). The 3D NMR structures of the analogues in dimethylsulfoxide are consistent with the observed binding affinities.

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INTRODUCTION: We report the results of a titanium acetabular reinforcement ring with a hook (ARRH) in primary total hip arthroplasty (THA), which was introduced in 1987 and continues to be used routinely in our center. The favorable results of this device in arthroplasty for developmental dysplasia and difficult revisions motivated its use in primary THA. With this implant only minimal acetabular reaming is necessary, anatomic positioning is achieved by placing the hook around the teardrop and a homogenous base for cementing the polyethylene cup is provided. MATERIALS AND METHODS: Between April 1987 and December 1991, 241 THAs with insertion of an ARRH were performed in 178 unselected, consecutive patients (average age 58 years; range 30-84 years) with a secondary osteoarthrosis in 41% of the cases. RESULTS: At the time of the latest follow-up, 33 patients (39 hips) had died and 17 cases had been lost to follow-up. The median follow-up was 122 months with a minimum of 10 years. Eight hips had been revised, leaving 177 hips in 120 living patients without revision. Six cups were revised because of aseptic loosening. Two hips were revised for sepsis. The mean Merle d'Aubigné score for the remaining hips was 16 (range 7-18) at the latest follow-up. For aseptic loosening, the probability of survival of the cup was 0.97 (95% confidence interval, 0.94-0.99). However, analysis of radiographs implied loosening in seven other cups without clinical symptoms. CONCLUSIONS: The results of primary THA using an acetabular reinforcement ring parallel the excellent results of these implants often observed in difficult primary and revision arthroplasty at a minimum of 10 years. Survivorship is comparable to modern cementless implants. Medial migration that occurs with loosening of the acetabular component seems to be prevented with this implant. Radiographic loosening signs can exist without clinical symptoms.

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The B-box motif is the defining feature of the TRIM family of proteins, characterized by a RING finger-B-box-coiled coil tripartite fold. We have elucidated the crystal structure of B-box 2 (B2) from MuRF1, a TRIM protein that supports a wide variety of protein interactions in the sarcomere and regulates the trophic state of striated muscle tissue. MuRF1 B2 coordinates two zinc ions through a cross-brace alpha/beta-topology typical of members of the RING finger superfamily. However, it self-associates into dimers with high affinity. The dimerization pattern is mediated by the helical component of this fold and is unique among RING-like folds. This B2 reveals a long shallow groove that encircles the C-terminal metal binding site ZnII and appears as the defining protein-protein interaction feature of this domain. A cluster of conserved hydrophobic residues in this groove and, in particular, a highly conserved aromatic residue (Y133 in MuRF1 B2) is likely to be central to this role. We expect these findings to aid the future exploration of the cellular function and therapeutic potential of MuRF1.

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Two novel bicyclo nucleoside isomers carrying the base thymine in the furanose ring and an ester substituent in the carbocyclic ring were synthesized from a common bicyclic sugar precursor via a cyclopropanation/fragmentation pathway in nine steps. The relative configuration of the ester substituent in both isomers as well as the anomeric configuration in one nucleoside was determined by 1H-NMR difference NOE spectroscopy.

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OBJECTIVES: To study the expression and the function of the 11beta-hydroxysteroid dehydrogenase enzyme 1 (11beta-HSD1) and 2 (11beta-HSD2) in placenta and the fetal membranes from pregnancies with intrauterine growth restriction (IUGR) and from controls. METHODS: Amnion, chorion, decidua and cotyledon were separated from placenta; mRNA was analyzed by TaqMan real-time technology and proteins by Western blot; enzyme activities were measured by the conversion of 3H-cortisol to 3H-cortisone and vice versa. RESULTS: Predominant mRNA expression (p < 0.001) was found for 11beta-HSD1 in chorion and for 11beta-HSD2 in decidua and cotyledon. In pregnancies with IUGR, 11beta-HSD1 was upregulated in chorion (mean DeltaCt 11beta-HSD:18S mRNA 193.5 vs. 103.0 in controls respectively, p < 0.05) and 11beta-HSD2 was downregulated in decidua (mean DeltaCt 11beta-HSD2:18S mRNA 0.18 vs. 15.88 in controls respectively, p < 0.05). 11beta-HSD1 protein levels were reduced in amnion and 11beta-HSD1 and 11beta-HSD2 oxidase activity in decidua and cotyledon were reduced from pregnancies with IUGR. CONCLUSION: Reduced synthesis or activity of 11beta-HSD1 or 2 in cases of IUGR is shown in some but not in all tissues. The local mRNA expression of 11beta-HSD1 in chorion may reflect a mechanism on the post-transcriptional gene regulation to stimulate the formation of cortisone in IUGR. To provoke increasing activity with oxidase stimulators could be a future therapy in cases of IUGR.

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A regioselective synthesis of unsymmetrical biaryls with electron withdrawing or donating substituents is described and illustrated by carbanion-induced ring transfonnation of 6-aryl-a-pyrones with methoxyacetone in excellent yield. Our methodology is an alternative to classical organometal-catalyzed aryl-aryl coupling reactions and can be applied to the synthesis of functionally demanding naphthyl biaryls for the development of new ligands for asymetric synthesis