Human C7(Complement component C7) ELISA Kit

Rationale: cMyBP-C (cardiac myosin-binding protein-C) is a critical regulator of heart contraction, but the mechanisms by which cMyBP-C affects actin and myosin are only partly understood. A primary obstacle is that cMyBP-C localization on thick filaments may be a key factor defining its interactions, but most in vitro studies cannot duplicate the unique spatial arrangement of cMyBP-C within the sarcomere. Objective: The goal of this study was to validate a novel hybrid genetic/protein engineering approach for rapid manipulation of cMyBP-C in sarcomeres in situ. Methods and Results: We designed a novel cut and paste approach for removal and replacement of cMyBP-C N '-terminal domains (C0-C7) in detergent-permeabilized cardiomyocytes from gene-edited Spy-C mice. Spy-C mice express a TEVp (tobacco etch virus protease) cleavage site and a SpyTag (st) between cMyBP-C domains C7 and C8. A cut is achieved using TEVp which cleaves cMyBP-C to create a soluble N '-terminal gamma C0C7 (endogenous [genetically encoded] N '-terminal domains C0 to C7 of cardiac myosin binding protein-C) fragment and an insoluble C '-terminal SpyTag-C8-C10 fragment that remains associated with thick filaments. Paste of new recombinant (r)C0C7 domains is achieved by a covalent bond formed between SpyCatcher (-sc; encoded at the C '-termini of recombinant proteins) and SpyTag. Results show that loss of gamma C0C7 reduced myofilament Ca2+ sensitivity and increased cross-bridge cycling (k(tr)) at submaximal [Ca2+]. Acute loss of gamma C0C7 also induced auto-oscillatory contractions at submaximal [Ca2+]. Ligation of rC0C7 (exogenous [recombinant] N '-terminal domains C0 to C7 of cardiac myosin binding protein-C)-sc returned pCa(50) and k(tr) to control values and abolished oscillations, but phosphorylated (p)-rC0C7-sc did not completely rescue these effects. Conclusions: We describe a robust new approach for acute removal and replacement of cMyBP-C in situ. The method revealed a novel role for cMyBP-C N '-terminal domains to damp sarcomere-driven contractile waves (so-called spontaneous oscillatory contractions). Because phosphorylated (p)-rC0C7-sc was less effective at damping contractile oscillations, results suggest that spontaneous oscillatory contractions may contribute to enhanced contractility in response to inotropic stimuli.

Study Design. Case-control study. Objective. To examine factors influencing cervical alignment after corrective surgery for adult patients with adolescent idiopathic scoliosis (AdIS) Summary of Background Data. Corrective surgery for spinal deformity influences postoperative cervical spinal alignment, but changes in the cervical alignment in adults with AdIS are scarcely reported. Methods. We retrospectively examined 85 patients with AdIS who underwent posterior corrective surgery for thoracic or lumbar major curve and were followed up for 2 years. Clinical characteristics, radiographic parameters, and health-related quality of life (HRQOL) were evaluated. Cervical deformity (CD) was defined as one of the following cases: (1) T1 tilt minus C2-C7 angle more than 20 degrees, (2) C2-C7 SVA more than 40 mm, (3) and C2-C7 angle less than -10 degrees. Patients were divided into those with and without CD based on the defined criteria; statistically relevant factors were analyzed. Results. There were 19 patients in the postoperative CD group. The average age at the time of surgery was lower in the CD group (26.5vs. 31.4). In the CD group, the average preoperative T1 tilt was smaller (1.1 degrees vs. 12.5 degrees), and the C2-C7 angle was kyphotic (-16.1 degrees vs. 3.0 degrees). The average kyphotic angle at thoracic spine (T5-T12) was lower in the CD group preoperatively (12.5 degrees vs. 19.5 degrees) and postoperatively (15.2 degrees vs. 20.8 degrees). HRQOL outcomes were comparable between the groups. Of the patients with preoperative CD, 51.5% (n = 17) maintained their deformity at the final follow-up, and baseline C2-C7 angle was lower than those who converted to non-CD following surgery (n = 16) (-17.0 degrees vs. -10.3 degrees). Conclusion. More than half of the patients with baseline CD maintained their cervical malalignment postoperatively. Patients with postoperative CD presented cervical kyphotic and thoracic hypokyphotic alignments before surgery. Because CD has the potential to lead to cervical degeneration, careful follow-up observation is necessary for these young patients.