Autologous chondrocyte implantation (ACI) is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We have performed a prospective, randomised comparison of ACI-C and MACI for the treatment of symptomatic chondral defects of the knee in 91 patients, of whom 44 received ACI-C and 47 MACI grafts. Both treatments resulted in improvement of the clinical score after one year. The mean modified Cincinnati knee score increased by 17.6 in the ACI-C group and 19.6 in the MACI group (p = 0.32). Arthroscopic assessments performed after one year showed a good to excellent International Cartilage Repair Society score in 79.2% of ACI-C and 66.6% of MACI grafts. Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43.9% of the ACI-C and 36.4% of the MACI grafts after one year. The rate of hypertrophy of the graft was 9% (4 of 44) in the ACI-C group and 6% (3 of 47) in the MACI group. The frequency of re-operation was 9% in each group. We conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI. While MACI is technically attractive, further long-term studies are required before the technique is widely adopted.

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8 for the iStent inject Study Group* Purpose: Evaluate the safety and effectiveness of an ab interno implanted (iStent inject) Trabecular Micro-Bypass System (Glaukos Corporation, San Clemente, CA) in combination with cataract surgery in subjects with mild to moderate primary open-angle glaucoma (POAG). Design: Prospective, randomized, single-masked, concurrently controlled, multicenter clinical trial. Participants: Eyes with mild to moderate POAG and preoperative intraocular pressure (IOP) 24 mmHg on 1 to 3 medications, unmedicated diurnal IOP (DIOP) 21 to 36 mmHg, and cataract requiring surgery. Methods: After uncomplicated cataract surgery, eyes were randomized 3:1 intraoperatively to ab interno implantation of iStent inject (Model G2-M-IS; treatment group, n ¼ 387) or no stent implantation (control group, n ¼ 118). Subjects were followed through 2 years postoperatively. Annual washout of ocular hypotensive medication was performed. Main Outcome Measures: Effectiveness end points were !20% reduction from baseline in month 24 unmedicated DIOP and change in unmedicated month 24 DIOP from baseline. Safety measures included best spectacle-corrected visual acuity (BSCVA), slit-lamp and fundus examinations, gonioscopy, pachymetry, specular microscopy, visual fields, complications, and adverse events. Results: The groups were well balanced preoperatively, including medicated IOP (17.5 mmHg in both groups) and unmedicated DIOP (24.8AE3.3 mmHg vs. 24.5AE3.1 mmHg in the treatment and control groups, respectively, P ¼ 0.33). At 24 months, 75.8% of treatment eyes versus 61.9% of control eyes experienced !20% reduction from baseline in unmedicated DIOP (P ¼ 0.005), and mean reduction in unmedicated DIOP from baseline was greater in treatment eyes (7.0AE4.0 mmHg) than in control eyes (5.4AE3.7 mmHg; P < 0.001). Of the responders, 84% of treatment eyes and 67% of control eyes were not receiving ocular hypotensive medication at 23 months. Furthermore, 63.2% of treatment eyes versus 50.0% of control eyes had month 24 medication-free DIOP 18 mmHg (difference 13.2%; 95% confidence interval, 2.9e23.4). The overall safety profile of the treatment group was favorable and similar to that in the control group throughout the 2-year follow-up. Conclusions: Clinically and statistically greater reductions in IOP without medication were achieved after iStent inject implantation with cataract surgery versus cataract surgery alone, with excellent safety through 2 years.

We have studied the processes which are elaborated by hippocampal neurons in dissociated cell culture. Nerve cells, which were obtained from fetal rats at 18 to 20 days of gestation, were plated at very low density onto polylysine-treated coverslips and were maintained in serum-free medium. Under such conditions, some cells develop without contacting any neighboring neurons or glial cells. Examples of such isolated cells which had developed for 1 week in culture were studied first by light microscopy, then they were sectioned parallel to the substratum so that all portions of the cell and its processes could be examined by electron microscopy. Dendrites and axons could be clearly distinguished by both light and electron microscopy. Dendrites were rather thick at the base but tapered rapidly to a minimum diameter of about 0.5 micron and contained polyribosomes throughout their length. Axons, which were several times longer than the dendrites, were thinner at the origin, tapered much less, and were essentially ribosome-free. These ultrastructural differences were particularly obvious at branch points, where cytoplasmic organelles tend to accumulate. Clusters of polyribosomes were invariably present at dendritic branch points, but they were never observed at axonal branch points. The axons most commonly arose from the proximal portion of a dendrite rather than directly from the cell body as they typically do in situ. These observations show that the fundamental differences in form and in the distribution of ribosomes between axons and dendrites can be established in cell culture. Contact with afferent fibers or with target cells during the period of process outgrowth is unnecessary for the expression of these features of axonal and dendritic differentiation.

We investigated the prognostic indicators for collagen-covered autologous chondrocyte implantation (ACI-C) performed for symptomatic osteochondral defects of the knee. We analysed prospectively 199 patients for up to four years after surgery using the modified Cincinnati score. Arthroscopic assessment and biopsy of the neocartilage was also performed whenever possible. The favourable factors for ACI-C include younger patients with higher pre-operative modified Cincinnati scores, a less than two-year history of symptoms, a single defect, a defect on the trochlea or lateral femoral condyle and patients with fewer than two previous procedures on the index knee. Revision ACI-C in patients with previous ACI and mosaicplasties which had failed produced significantly inferior clinical results. Gender (p = 0.20) and the size of the defect (p = 0.97) did not significantly influence the outcome.