Compensatory changes in the hippocampus of somatostatin knockout mice: upregulation of somatostatin receptor 2 and its function in the control of bursting activity and synaptic transmission

Somatostatin-14 (SRIF) co-localizes with gamma-aminobutyric acid (GABA) in the hippocampus and regulates neuronal excitability. A role of SRIF in the control of seizures has been proposed, although its exact contribution requires some clarification. In particular, SRIF knockout (KO) mice do not exhibit spontaneous seizures, indicating that compensatory changes may occur in KO. In the KO hippocampus, we examined whether specific SRIF receptors and/or the cognate peptide cortistatin-14 (CST) compensate for the absence of SRIF. We found increased levels of both sst2 receptors (sst2) and CST, and we explored the functional consequences of sst2 compensation on bursting activity and synaptic responses in hippocampal slices. Bursting was decreased by SRIF in wild-type (WT) mice, but it was not affected by either CST or sst2 agonist and antagonist. sst4 agonist increased bursting frequency in either WT or KO. In WT, but not in KO, its effects were blocked by agonizing or antagonizing sst2, suggesting that sst2 and sst4 are functionally coupled in the WT hippocampus. Bursting was reduced in KO as compared with WT and was increased upon application of sst2 antagonist, while SRIF, CST and sst2 agonist had no effect. At the synaptic level, we observed that in WT, SRIF decreased excitatory postsynaptic potentials which were, in contrast, increased by sst2 antagonist in KO. We conclude that sst2 compensates for SRIF absence and that its upregulation is responsible for reduced bursting and decreased excitatory transmission in KO mice. We suggest that a critical density of sst2 is needed to control hippocampal activity.     

PTA Versus Carbofilm-Coated Stents in Infrapopliteal Arteries: Pilot Study

Purpose: To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study. Methods: Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47–80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan–Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions. Results: The inter-reader agreement was high (κ = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05). Conclusion: Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.     

Changes of gait patterns and muscle activity after intraarticular treatment of patients with osteoarthritis of the knee: A prospective, randomised, doubleblind study

Evaluation of gait performance and muscle activity patterns as well as clinical efficacy and safety after intraarticular injections with hyaluronan (Ostenil) compared with triamcinolone (Volon A10) injections in patients with knee osteoarthritis.This was a prospective, randomised, double-blind clinical trial evaluating the influence of five injections of hyaluronan or triamcinolone on gait pattern and muscle activity. For the clinical evaluation visual analogue scale, Lequesne index, and Knee Society Score were used. Quality of life was estimated with the SF-36.The definitive analysis was performed on the population who received all five injections and were examined in the two follow-up visits. Fifteen patients were treated with triamcinolone and 20 with hyaluronan. Significant improvement could be demonstrated for pain scale and clinical scores in both groups. Gait patterns showed significant differences only for Knee Abduction Moment (p = 0.007) in the hyaluronan group and for Maximum Vertical Force 1 and 2 between the both groups in the follow up visit (p = 0.018) (p = 0.019). In both groups there was no significant difference regarding to muscle activity. Quality of life showed no changes in all visits between the groups.Hyaluronan was not superior to triamcinolone. The results suggest that treatment with hyaluronan can reduce pain and improve knee function. A significant short term improvement in gait and muscle activity patterns, however, was not observed, in either hyaluronan or triamcinolone.     

Fracture of the femur head--description of four cases

Fracture of the femur head is most ofen caused by car accidents and a falls from a height. Treatment of these fractures is hard and is burden risk of aseptic necrosis of the femoral head and arthritis of the hip joint. In the paper are presented four cases of femur head fracture. Two of them were treated by surgical procedure, one using conservative therapy and one using total hip replacement for reason arthritis of the hip joint.     

Chondrocyte function after osteochondral transfer: comparison of concave and plane punches

Background  

An incongruity between instrument and articular surfaces in osteochondral transfer (OCT) results in unevenly distributed impact forces exerted on the cartilage which may cause a loss of functional chondrocytes. We tested whether a plane instead of a concave design of the punch of an osteotome can reduce these cartilage damages.     

Single-molecule spectroscopy of protein folding in a chaperonin cage

Molecular chaperones are known to be essential for avoiding protein aggregation in vivo, but it is still unclear how they affect protein folding mechanisms. We use single-molecule Förster resonance energy transfer to follow the folding of a protein inside the GroEL/GroES chaperonin cavity over a time range from milliseconds to hours. Our results show that confinement in the chaperonin decelerates the folding of the C-terminal domain in the substrate protein rhodanese, but leaves the folding rate of the N-terminal domain unaffected. Microfluidic mixing experiments indicate that strong interactions of the substrate with the cavity walls impede the folding process, but the folding hierarchy is preserved. Our results imply that no universal chaperonin mechanism exists. Rather, a competition between intra- and intermolecular interactions determines the folding rates and mechanisms of a substrate inside the GroEL/GroES cage.