Nuclear immobilization of DsRed1 tagged proteins: A novel tool for studying DNA–protein interactions?

AbstractDsRed1 is a red fluorescent protein that can be used as a fusion partner with other proteins to determine their subcellular localization, similarly to the popular green fluorescent proteins (GFP). Here, we report that fusion of DsRed1 to estrogen receptor α (ERα) renders the transcription factor immobile within the nucleus. Furthermore, we show that the immobilization is dependent on DNA interaction and that the binding to the DNA can be direct as well as indirect for DsRed to immobilize with its fusion partners. This observation could provide a new tool to be used for the identification of target genes containing low affinity binding sites for several transcription factors including ERα. In addition, it could be employed for studies on protein–DNA interactions as well as protein–protein interactions during protein complex formation on chromatin in the event of transcription initiation and regulation

Current trends in operative treatment of carpometacarpal osteoarthritis: a survey of European hand surgeons

Background: Surgical practice patterns in operative treatment of carpometacarpal (CMC-1) osteoarthritis (OA) have been evaluated in the USA repeatedly. This study evaluates the current surgical patterns in the treatment of isolated CMC-1 OA among hand surgeons in Europe. Methods: An online survey was distributed to hand surgeons of participating member states of the Federation of European Societies for Surgery of the Hand (FESSH). Information regarding country of practice, years of experience and surgical treatment of choice was collected. Statistical analyses of correlations between demographics and treatment preferences were done using chi-squared testing. Results: A total of 444 replies were recorded. Trapeziectomy with ligament reconstruction and tendon interposition (LRTI) was opted by 46% of the respondents as a procedure of first choice, followed by prosthetic joint replacement (25%) and trapeziectomy with interpositional arthroplasty (23%). Among surgeons practicing in the Netherlands, 35% mentioned trapeziectomy without any complementary procedures as a surgical treatment of first choice. Prosthetic joint replacement is chosen by respectively 96% and 72% of the respondents in Belgium and France as a preferred surgical procedure. Conclusions: This European-wide study provides insight in the prevailing surgical management for isolated CMC-1 OA. Trapeziectomy with LRTI is the most popular procedure among the participating hand surgeons in Europe. Geographical trends seem to play an important role in the choice of preferred technique. Factors influencing the decision-making among surgeons practicing in different countries should be explored more closely in future studies. Level of evidence: Level IV, prognostic study

Distal Pole Resection of the Scaphoid for the Treatment of Scaphotrapeziotrapezoid Osteoarthritis

Background: Distal pole resection of the scaphoid is one of the surgical techniques applied for the treatment of painful scaphotrapeziotrapezoid osteoarthritis (STT-OA). Methods: In this retrospective study, we evaluated midterm outcomes in a consecutive series of patients who underwent distal pole resection of the scaphoid: 13 patients (15 wrists) with a mean follow-up of 4.1 years. We examined objective functional and patient-reported outcome measures. In addition, we assessed the degree of dorsal intercalated segment instability (DISI) and postoperative complications. Results: All patients scored within a normal range on objective functional and patient-reported outcome measures. We observed a mild postoperative DISI deformity with an average lunocapitate angle of 22° (range, 0°-44°), which did not correlate with pain scores. In the opposite wrists, with and without STT-OA, the average lunocapitate angle was 6° (range, 0°-20°). Conclusions: According to this study, midterm results for distal pole resection of the scaphoid are satisfactory

MRI Findings in Patients Undergoing Triangular Fibrocartilage Complex Repairs Versus Patients Without Ulnar-Sided Wrist Pain

Background: The clinical picture of ulnar-sided wrist pain is oftentimes confusing because various pathologies may be coexistent. In this study, we aimed: (1) to compare the prevalence of potential causes of ulnar-sided wrist pain on magnetic resonance imaging (MRI) in patients who underwent triangular fibrocartilage complex (TFCC) repair and control subjects: and (2) to evaluate whether inferior clinical results were associated with specific patient characteristics or other potential causes of ulnar-sided wrist pain. Methods: We included 67 patients who underwent a TFCC repair and 67 control subjects. The MRI scans were examined for sources of ulnar-sided wrist pain. After TFCC repair, 42 patients (63%) completed surveys, including Quick Disabilities of the Arm, Shoulder and Hand and pain scores. Bivariate analysis was performed to compare our groups and to identify factors associated with our outcomes. Results: We found significantly higher rates of distal radioulnar joint (DRUJ) arthritis (P =.033), extensor carpi ulnaris (ECU) pathology (P =.028), and ulnar styloid fractures (P =.028) in patients with TFCC repairs. With increasing age, increasing pathology in the pisotriquetral joint (P =.040), more ulnocarpal abutment (P =.0081), and more degenerative tears (P <.001) were seen in both groups. No demographic characteristics or MRI findings were significantly associated with our outcomes. Conclusions: We observed higher rates of DRUJ arthritis and ECU pathology in patients with TFCC tears undergoing repair compared with age- and sex-matched controls. This may be due to damage to the TFCC itself altering relationships of the DRUJ and the ECU subsheath, or it may reflect various pathologies that cause ulnar-sided wrist pain and drive patients toward surgery

Radiation Exposure to Surgeon and Assistant During Flat Panel Mini C-Arm Fluoroscopy in Hand and Wrist Surgical Procedures

Purpose: During mini C-arm fluoroscopy, both the patient and surgical team are exposed to scatter radiation. The objective of this study was to quantify body, thyroid, and hand radiation exposure to surgeon and assistant during intraoperative use of flat panel mini C-arm fluoroscopy in hand and wrist surgical procedures. Methods: Over 5 months, the surgeon's and assistant's radiation exposure was recorded during all osseous hand and wrist surgical procedures. Whole-body and thyroid radiation exposure were measured with 2 types of dosimeters: a photon thermoluminescence detector and a RaySafe i2 real-time dosimeter. Ring dosimeters were used to quantify hand radiation exposure. Results: Mini C-arm fluoroscopy was used in 94 surgical procedures. Total fluoroscopy time was 1,996 seconds and varied between surgical procedures (range, 1-152 seconds; median, 11 seconds). No thermoluminescence detector photon dosimeter exceeded the threshold limit of 0.1 mSv. The RaySafe i2 real-time dosimeters recorded a cumulated dose of 0.029 mSv for the body and 0.012 mSv for the thyroid position of the surgeon. The assistant received a cumulated dose of 0.011 mSv for the body and 0.011 mSv for the thyroid position. The ring dosimeters showed a cumulated dosage of 1.28 mSv for the surgeon and 0.20 mSv for the assistant. Conclusions: Our results show that the surgeon's and assistant's body, thyroid, and hands were exposed to acceptable levels of scatter radiation during intraoperative use of the flat panel mini C-arm. The surgeon received the highest radiation exposure: 2.9% of the yearly radiation limits for the body, 0.05% for the thyroid position, and 2.56% for the hands. The assistant was exposed to less scatter radiation: 1.1% for the body, 0.04% for the thyroid, and 0.4% for the hands. Clinical relevance: This study quantified radiation levels to which surgeon and assistant are exposed during mini C-arm fluoroscopy in hand and wrist surgical procedures

Interobserver reliability of the Mallet score

The interobserver reliability of the Mallet score for active shoulder function was assessed by three experienced observers in a group of 30 children with an obstetric brachial plexus lesion (mean age 7.1 years, range 4.5-10 years). Interobserver reliability, measured using weighted κ, was good. Kappa varied between 0.37 and 0.84 and differed between the different aspects of the Mallet score and different pairs of observers. In decreasing order, mean weighted κ was 0.75 for abduction, 0.73 for hand to neck, 0.67 for hand to spine, 0.6 for external rotation and 0.53 for hand to mouth

Scaphoid kinematics in vivo

The purpose of this study was to quantify 3-dimensional (3-D) in vivo scaphoid kinematics during flexion-extension motion (FEM) and radial-ulnar deviation (RUD) of the hand. The right wrists of 11 healthy volunteers were imaged by spiral computed tomography during RUD and 5 of those wrists also during FEM. With a matching technique, relative translations and rotations of the scaphoids were traced. Our results showed a broad spectrum of kinematic patterns of the scaphoid during RUD, with small intercarpal motions within the proximal carpal row. Some scaphoids rotated basically around the flexion-extension axis only whereas others rotated almost entirely around the deviation axis during RUD. During FEM we found highly uniform scaphoid motion patterns with large intercarpal motions within the proximal carpal row. These findings suggest that current theories cannot sufficiently explain wrist kinematics and stress the need for more in vivo studies on 3-D carpal kinematics

Rotational stability of the carpus relative to the forearm

To perform rotational tasks adequately, the rotational laxity between the radius and the carpus must be constrained within a certain limit. The contribution of nine individual capsuloligamentous structures to the rotational stability of the radiocarpal joint was studied using 14 freshfrozen human cadaveric specimens. Torque-rotation curves, with sequential section of the soft-tissue structures, were used to calculate the percentage contribution of each individual structure. The primary pronation constraint was the palmar radioscaphocapitate ligament. The contributions to supination constraint were more complex; the dorsal radiotriquetral ligament was dominant, assisted by the palmar ulnolunate ligament. Structures originating from the ulna changed their major constraint contribution with forearm orientation, whereas those with a radial origin had a constant contribution independent of forearm rotation. Injury of these structures may lead to rotational instability at the radiocarpal level and should be considered when treating carpal instabilities

Axial loading induces rotation of the proximal carpal row bones around unique screw-displacement axes

The changes in carpal bone alignment secondary to the aplication of an axial compressive load through the major wrist motor tendons while the wrist is kept in neutral position (isometric loading) have been investigated on 13 fresh cadaver specimens using a biplanar radiographic method of kinematic analysis. The scaphoid, lunate and triquetrum rotate an average of 5.1, 4.2 and 3.8°, respectively, around different 'screw displacement axes', all implying flexion, radial deviation and supination. Based on these findings, a new interpretation of the mechanism by which the wrist remains stable under physiologic loads is provided