Synframe: a preliminary report

Both endoscopic lumbar spinal surgery and the non-standardized and unstable retractor systems for the lumbar spine presently on the market have disadvantages and limitations in relation to the minimally invasive surgical concept, which have been gradually recognized in the last few years. In an attempt to resolve some of these issues, we have developed a highly versatile retractor system, which allows access to and surgery at the lumbar, thoracic and even cervical spine. This retractor system – Synframe – is based on a ring concept allowing 360° access to a surgical opening in anterior as well as posterior surgery. The ring is concentrically laid over the surgical opening for the approach and is used as a carrier for retractor arms, which are instrumented with either different sizes or types of blades and/or different sizes of Hohmann hooks. In posterior surgery, nerve root retractors can also be installed. This ring also functions as a carrier for fiberoptic illumination devices and different sizes of endoscopes, used to transmit the surgical procedure out of the depth of the surgical exposure for both teaching purposes and for the surgical team when it has no longer direct visual access to the procedure. The ring is stable, being fixed onto the operating table, allowing precise minimally open approaches and surgical procedures under direct vision with optimal illumination. This ring system also opens perspectives for an integrated minimally open surgical concept, where the ring may be used as a reference platform in computer-navigated surgery.     

Synframe: a preliminary report

Both endoscopic lumbar spinal surgery and the non-standardized and unstable retractor systems for the lumbar spine presently on the market have disadvantages and limitations in relation to the minimally invasive surgical concept, which have been gradually recognized in the last few years. In an attempt to resolve some of these issues, we have developed a highly versatile retractor system, which allows access to and surgery at the lumbar, thoracic and even cervical spine. This retractor system - Synframe - is based on a ring concept allowing 360° access to a surgical opening in anterior as well as posterior surgery. The ring is concentrically laid over the surgical opening for the approach and is used as a carrier for retractor arms, which are instrumented with either different sizes or types of blades and/or different sizes of Hohmann hooks. In posterior surgery, nerve root retractors can also be installed. This ring also functions as a carrier for fiberoptic illumination devices and different sizes of endoscopes, used to transmit the surgical procedure out of the depth of the surgical exposure for both teaching purposes and for the surgical team when it has no longer direct visual access to the procedure. The ring is stable, being fixed onto the operating table, allowing precise minimally open approaches and surgical procedures under direct vision with optimal illumination. This ring system also opens perspectives for an integrated minimally open surgical concept, where the ring may be used as a reference platform in computer-navigated surgery.     

Oncological validation of bone turnover markers c-terminal telopeptide of type I collagen (1CTP) and peptides n-terminal propeptide of type I procollagen (P1NP) in patients with prostate cancer and bone metastases

BackgroundBone formation markers c-terminal telopeptide of type I collagen (1CTP) and peptides n-terminal propeptide of type I procollagen (P1NP) were reported to be increased in patients with prostate cancer (PC) and bone metastases. The objective of the presented study was to investigate the utility of serum 1CTP and P1NP values in the diagnosis of bone metastases and in predicting oncological outcome in patients with PC.MethodsIn total, serum samples of 186 patients were included retrospectively including 53 (28.50%) benign prostatic hyperplasia (BPH) patients and 133 (71.50%) PC-patients. The group of patients with PC consisted of 58 patients with non-metastatic PC (cM0) (43.61%) and 70 (52.63%) patients with bone metastases (cM1b). Serum 1CTP and P1NP were measured by radioimmunoassay (RIA). Results were compared to clinical variables including oncologic follow-up data by univariate and multivariate analyses.ResultsMedian 1CTP concentrations were significantly higher in patients with PC compared to the BPH group [5.08 (range, 1.73–158.00) vs. 4.00 (range, 2.18–34.19) µg/L, P=0.019]. However, no significant difference of P1NP levels could be shown for these groups. With median values of 6.04 (1.73–158.00) and 3.91 µg/L (2.04–34.51) for 1CTP and 48.60 (9.12–1,074.37) and 33.90 (8.72–149.30) for P1NP both markers were altered in cM1b patients compared to cM0 patients (P=0.001 each). Furthermore, cancer-specific survival (CSS) and overall survival (OS) were significantly shorter in cM1b patients with higher 1CTP concentrations (P=0.037 and P=0.019, respectively), whereas no associations of P1NP and outcomes were observed.ConclusionsThe present study confirms that increased levels of 1CTP and P1NP concentrations are associated with presence of metastatic disease in the bone. Moreover, these markers are able to predict clinical course in PC patients with bone metastases. The potential use of these markers for treatment selection in advanced PC remains to be determined.     

Cysteine protease activity is up‐regulated in inflamed ankle joints of rats with adjuvant‐induced arthritis and decreases with in vivo administration of a vinyl sulfone cysteine protease inhibitor

Objective

Cysteine proteases are postulated to play a role in tissue destruction in the joints of animals with arthritis. The purpose of the present study was to confirm the concept that cysteine proteases are enzymes involved in the pathology of rheumatoid arthritis (RA).

Methods

Arthritis was induced in Lewis rats by adjuvant injection (adjuvant‐induced arthritis [AIA] model) and scored for inflammation. At necropsy, the rear paws were either fixed in formalin and assigned a histologic score (based on synovial cell proliferation, cartilage erosion, bone erosion, and fibroproliferative pannus) or frozen, cryosectioned, and assayed for enzyme activity either by in situ cytochemical staining with a post‐azo‐coupling method using a chromogenic substrate (Z‐arg‐arg‐MNA) or by a novel assay placing the tissue section directly in a cuvette using the fluorogenic substrate Z‐arg‐arg‐AMC.

Results

Enzymatic activity, measured either in frozen sections in situ or in the cuvette assay, was positively correlated with joint destruction (r = 0.7) and inflammation (r = 0.8). Activity was not inhibited significantly by Pefabloc (a serine protease inhibitor), EDTA (a metalloprotease inhibitor), or pepstatin A (an aspartyl protease inhibitor) but was inhibited by E‐64 and vinyl sulfone irreversible inhibitors of cysteine proteases. The effect of one of the vinyl sulfone cysteine protease inhibitors, Mu‐Leu‐HomoPhe‐vinylsulfone, was tested in vivo by dietary administration at 2.2 mg/kg/day in the AIA model; this resulted in a significant decrease in inflammation and in the amount of cysteine protease activity measured in the joint tissue.

Conclusion

Cysteine protease activity levels increase in the diseased state and may be an important target for designing small molecule inhibitors to reduce the inflammation and tissue destruction associated with RA.

     

Structural changes of cellulose dissolved in molten salt hydrates

The behavior of cellulose in molten salt hydrates, e. g., LiClO₄*3 H₂O, ZnCl₂*4 H₂O, LiCl*5 H₂O and mixtures of thiocyanates was investigated. Melts, which give rise to a swelling or dissolution of the cellulose were the focus of interest. The melt composition and species, the water amount and the structure of the coordination sphere of the cation of the molten salt hydrate as well as the acidity influence the solubility of the cellulose in molten salt systems. The interactions between cellulose and species of the melts were determined by solution state ¹³C NMR measurements at temperatures between 65°C and 140°C. Each regenerated cellulose showed other but specific properties which were characterized by wide angle X‐ray Scattering (WAXS), solid‐state NMR (¹³C CP/MAS NMR), molecular weight distribution, surface‐area determinations and scanning electron microscopy (SEM).     

Central retinal artery occlusion as a first sign of atrial fibrillation: A 3‐year retrospective single‐center analysis

BackgroundCentral retinal artery occlusion ((C)RAO) is known to be associated with stroke and/or atrial fibrillation (AF). Nevertheless, patients often present at the ophthalmologist initially and it is unknown how many of these receive an adequate cardiological/neurological work‐up (CWU/NWU), including a 24 h‐Holter‐ECG.HypothesisHypothesis of this study was that patients with (C)RAO do not undergo CWU on regular basis and that new‐onset AF is more often detected in patients with CWU.Methods and resultsWe performed a retrospective analysis of n = 292 consecutive patients who presented at an ophthalmology department with the diagnosis of (C)RAO during a 3‐year period. After excluding patients with known AF, meeting exclusion criteria, inability to comply with the protocol, missed land phoneline, or death during follow‐up a total of 174 patients were enrolled; mean follow‐up was 20 ± 12 months. The CHA₂DS₂‐VASc score of the cohort was 5.3 ± 1.4. Our analysis revealed that only 50.6% of patients received a CWU including a single Holter‐ECG after the index‐event. In 12.6% cases new‐onset AF was diagnosed, while the rate was higher in patients with CWU compared to patients without CWU (18.2 vs. 7.0%; p = 0.26). Evaluation of oral anticoagulation (OAC) therapy showed that only 66% of patients with AF were treated according to guidelines.ConclusionOnly half of patients with (C)RAO underwent CWU. Despite minimal monitoring, rate of new diagnosed AF was high. Our results confirm that (C)RAO identifies a high‐risk population for AF. These results illustrate the importance to implement standardized CWU in (C)RAO patients presenting at the ophthalmologist.