Zmpste24 is an integral membrane metalloproteinase of the endoplasmic reticulum. Biochemical studies of tissues from Zmpste24-deficient mice (Zmpste24 ؊/؊ ) have indicated a role for Zmpste24 in the processing of CAAX-type prenylated proteins. Here, we report the pathologic consequences of Zmpste24 deficiency in mice. Zmpste24 ؊/؊ mice gain weight slowly, appear malnourished, and exhibit progressive hair loss. The most striking pathologic phenotype is multiple spontaneous bone fractures-akin to those occurring in mouse models of osteogenesis imperfecta. Cortical and trabecular bone volumes are significantly reduced in Zmpste24 ؊/؊ mice. Zmpste24 ؊/؊ mice also manifested muscle weakness in the lower and upper extremities, resembling mice lacking the farnesylated CAAX protein prelamin A. Prelamin A processing was defective both in fibroblasts lacking Zmpste24 and in fibroblasts lacking the CAAX carboxyl methyltransferase Icmt but was normal in fibroblasts lacking the CAAX endoprotease Rce1. Muscle weakness in Zmpste24 ؊/؊ mice can be reasonably ascribed to defective processing of prelamin A, but the brittle bone phenotype suggests a broader role for Zmpste24 in mammalian biology.metalloproteinase ͉ knockout mice ͉ brittle bones ͉ CAAX motif T he mammalian zinc metalloproteinase Zmpste24 has attracted attention because it shares a high degree of sequence identity with Ste24p, a Saccharomyces cerevisiae enzyme required for the maturation of the farnesylated mating pheromone a-factor (1-3). Ste24p plays two distinct roles in a-factor biogenesis (2, 4). First, it acts as a CAAX endoprotease, clipping off the C-terminal three amino acids from the protein (i.e., the ϪAAX of the CAAX motif) (3). Release of the ϪAAX from a-factor can also be mediated by Rce1p, the CAAX endoprotease involved in Ras processing (3). The removal of the ϪAAX exposes a carboxyl-terminal farnesylcysteine, which is methylated by Ste14p (5). Second, Ste24p clips the amino-terminal extension of a-factor, rendering it susceptible to a final endoproteolytic cleavage by Axl1p or Ste23p (6). Aside from a-factor, no other substrates for Ste24p have been identified, but other substrates likely exist because genetic screens in yeast have demonstrated that STE24 mutations can reverse the topological orientation of membrane proteins (7) and can affect the viability of yeast with mutations in genes encoding actin cytoskeleton proteins (8).Zmpste24 faithfully carries out both of Ste24p's processing steps in a-factor biogenesis and thus is a bona fide Ste24p ortholog (2, 9). Although it would be tempting to speculate that Zmpste24 processes an ''a-factor-like'' peptide in mammals, no a-factor ortholog has yet been identified. We have previously speculated that prelamin A (a precursor to lamin A, a component of the nuclear lamina) might be a Zmpste24 substrate (2, 6) because prelamin A (like yeast a-factor) is a farnesylated CAAX protein that undergoes more than one proteolytic processing step (10). After the removal of the C-terminal ϪAAX, an additional 15 res...

The retropupillary fixation of an iris claw lens seems to have the advantages of a true posterior chamber implantation with a low intra- and postoperative risk profile. The easy implantation process with this technique could replace the normally applied sclera suture fixed implantation of a posterior chamber lens as the method of choice.

FS PDw TSE is an accurate method for detecting, grading and sizing articular cartilage lesions of the knee and yielded superior results relative to WE 3D FLASH MR imaging.

PurposeTo evaluate the relationship between duration of macular edema associated with retinal vein occlusion (RVO) and the achievement of vision gain in patients receiving dexamethasone intravitreal implant (DEX implant) in real-world clinical practice, and to define patterns of use of DEX implant and its efficacy and safety in the treatment of patients with RVO in clinical practice.MethodsThis prospective, open-label, multicenter, 6-month observational phase IV study conducted at 70 sites in Germany enrolled patients diagnosed with macular edema following branch or central RVO (BRVO, CRVO) who were given DEX implant. Follow-up visits and evaluations occurred in accordance with normal clinical practice. Re-treatment with DEX implant and use of other RVO therapies was at the discretion of the treating physician. The primary endpoint was mean change in best-corrected visual acuity (BCVA) from baseline at week 12.ResultsThe analysis population consisted of 573 patients (64 % BRVO, 36 % CRVO). Patients received a mean of 1.17 DEX implant treatments during the study period; 84.3 % of patients received a single DEX implant and 19.9 % received adjunctive other RVO treatment. Among patients with analyzable BCVA data at baseline and week 12 (n = 351), mean change from baseline BCVA at week 12 was −0.16 (standard deviation, 0.30) logMAR (+7.8 approximate Early Treatment Diabetic Retinopathy Study [ETDRS] letters) (p < 0.001), and 33.9 % of patients had gained at least 3 lines in BCVA from baseline. Mean change from baseline BCVA at week 12 was +9.5, +7.3, and +5.4 approximate ETDRS letters in patients with macular edema duration < 90 days, from 90 to 180 days, and >180 days respectively. Improvement in BCVA through week 24 and decreases in central retinal thickness were seen in both BRVO and CRVO. The most common adverse drug reaction was increased intraocular pressure. No glaucoma incisional surgeries were required.ConclusionsDEX implant was effective in improving BCVA and central retinal thickness in patients with BRVO and CRVO in real-world clinical practice. The largest gains in BCVA over 6 months occurred in patients with recent onset macular edema, confirming the benefit of early treatment. DEX implant was well tolerated and had an acceptable safety profile.

Objective To assess the cross-sectional association between meniscal status and joint effusion on magnetic resonance imaging (MRI) in knees without radiographic osteoarthritis. Design Knees without osteoarthritis (Kellgren/Lawrence grade 0) from the Framingham and MOST studies were examined by MRI. Meniscal status was assessed with a score of 0–4 in the anterior horn/body/posterior horn of the medial/lateral meniscus and effusion was assessed using a score of 0 to 3. The odds ratios (OR) of joint effusion in those with meniscal damage were estimated using a logistic regression model. A subanalysis was performed for knees without MRI detected cartilage damage. Results Of 1368 knees, 296 (21.6%) showed meniscal pathology in at least one subregion. Effusion was present in 133 (44.9%) of knees with meniscal damage vs. 328 (30.6%) in those without meniscal damage. The adjusted OR of effusion in a knee with meniscal damage was 1.8, 95% confidence intervals (CI) [1.4, 2.4]. The OR of effusion for the group with meniscal pathology in two compartments was 5.4, 95% CI [2.1, 14.3]. For knees without any cartilage lesions but with meniscal damage in any compartment the OR was 2.3, 95% CI [1.1, 4.5]. Conclusions Knees without osteoarthritis but with meniscal pathology exhibit joint effusion to a significantly higher degree than knees without meniscal damage. The association persists for knees without cartilage damage. The prevalence of effusion is further increased when present in two compartments. Concomitant occurrence of synovial activation and meniscal damage contributes to understanding the pathophysiology of early degenerative joint disease.

Objectives To describe the association of osteophytes with concomitant cartilage damage in a population-based cohort using semiquantitative MRI assessment and to describe the prevalence of atrophic and hypertrophic phenotypes of tibio-femoral knee osteoarthritis. Methods Participants of the Framingham Knee Osteoarthritis Study were examined with a 1.5 T MRI system using triplanar intermediate-weighted fat suppressed sequences. Cartilage and osteophytes were assessed according to the WORMS scoring system. Overall prevalence of knees with severe cartilage damage and concomitant osteophyte status was described. The odds ratios of severe cartilage damage according to osteophyte size were estimated using a logistic regression model. An additional analysis assessed knees with absent or only tiny osteophytes (≤2 on a 0-7 scale) in all 10 tibio-femoral subregions but with severe cartilage damage (atrophic phenotype) and knees with large osteophytes (≥5 on a 0-7 scale) and without substantial cartilage damage (hypertrophic phenotype) in regard to radiographic osteoarthritis status. Results 1597 knees of 1248 subjects were included. 54 of 67 (80.6%) knees with large osteophytes exhibited severe cartilage damage. The risk of severe cartilage damage increased markedly with increasing osteophyte size. 21 knees (1.3%) showed an atrophic phenotype. Only 3 knees (0.2%) exhibited a hypertrophic phenotype. Conclusions The majority of knees with severe tibio-femoral cartilage damage exhibit moderate to large osteophytes. The larger the osteophyte, the more likely there was severe cartilage damage. A minority of knees exhibits the so-called atrophic phenotype, which also includes knees without radiographic osteoarthritis. The hypertrophic phenotype is extremely rare

Aim of this study was to develop a time-efficient sequence protocol for a 1.0 T dedicated MR system to be used for whole-organ scoring of osteoarthritis (OA). Thirty-four knees were examined using a protocol that included fat suppressed fast spin echo proton density weighted sequences (PDFS) in three planes plus a coronal STIR sequence. Two radiologists scored each knee by consensus for five OA features. In separate sessions, all knees were scored using three different combinations of sequences: (1) all four sequences (reference protocol, 16 min 31 s scanning time), (2) three PDFS sequences without STIR ("No STIR", 12 min 25 s scanning time) and (3) sagittal and axial PDFS sequences plus a coronal STIR sequence ("No PDFS", 11 min 49 s scanning time). Agreement of the readings using both subsets of sequences compared to the reference protocol was evaluated using weighted kappa statistics. kappa-coefficients showed good or excellent agreement for both sequence subsets in comparison to the reference protocol for all assessed features. kappa-coefficients for No PDFS/No STIR: bone marrow abnormalities (0.74/0.67), subarticular cysts (0.84/0.63), marginal osteophytes (0.77/0.71), menisci (0.75/0.79), tibial cartilage (0.71/0.78). Optimization of sequence protocols consisting of three sequences results in time savings and cost efficiency in imaging of knee OA without loss of information over a more time consuming protocol.

For short incubation times, all dyes appear equally safe. For longer incubation times, TB preparations were more toxic than BBG preparations. The toxicity of TB was reduced by the addition of PEG. Further studies are required to determine the clinical impact of this finding.