Bone channeling in arthroscopic rotator cuff repair: a systematic review and meta-analysis of level I studies.

BACKGROUND: There is ongoing controversy regarding the effect of bone channeling in arthroscopic rotator cuff repair. Since the most recent systematic reviews in 2019, several large high-level trials have been completed. This study assessed all available level I randomized controlled trials (RCTs) that compared arthroscopic rotator cuff repair with and without bone marrow channeling. METHODS: A systematic search of the Ovid MEDLINE, Embase, and Cochrane Library databases was conducted through mid January 2023. Two reviewers performed screening of studies meeting the eligibility criteria: English-language RCTs in patients aged ≥18 years comparing arthroscopic rotator cuff repair of full-thickness tears with and without bone marrow channeling (channeling group and control group, respectively). Functional scores, pain, healing rates, and reoperations were reviewed using pooled analysis where appropriate. The methodologic quality of included studies was assessed using the Cochrane risk-of-bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: A total of 6 randomized studies (N = 593) met the inclusion criteria. Pooled analysis of all 6 studies showed no significant mean difference in function (1.32; 95% confidence interval [CI], -0.63 to 3.26), as measured by the Constant-Murley score. Retear rates were also not statistically different between groups (risk ratio, 0.99; 95% CI, 0.57 to 1.71), with pooled retear rates of 19.6% (48 of 245) with channeling and 19.8% (51 of 257) without. The other outcomes of interest were only available for analysis in a subset of studies. There were no standardized mean differences in pain (0.09; 95% CI, -0.18 to 0.36), and there were similar reoperation rates (risk ratio, 1.19; 95% CI, 0.43 to 3.34) in the channeling and control groups. For the included studies, the overall quality of evidence by outcome was judged to be moderate (function, pain, and reoperations) or low (retear rates), mainly owing to risk of bias (all outcomes) and inconsistency (retear rates). CONCLUSION: The results of this study refute the findings of prior systematic reviews that showed that channeling reduces the retear rate when combined with arthroscopic rotator cuff repair. This meta-analysis of level I evidence, including recent larger RCTs, demonstrates that bone marrow stimulation in the setting of primary arthroscopic rotator cuff repair has no significant effect on functional outcomes, healing, pain, or reoperation rates.

What are the common factors that lead to the failure to achieve minimal clinically important difference after shoulder surgery? A scoping review.

INTRODUCTION: The goal of this research is to identify the factors that negatively impact the achievement of the minimum clinically significant change (MCID) for the American Shoulder and Elbow Surgeons (ASES) score within the realm of various orthopedic shoulder procedures. METHODS: We conducted a comprehensive review of studies published from 2002 to 2023, utilizing OvidMedline and PubMed databases. Our search criteria included terms such as "minimal clinically important difference" or "MCID" along with associated MeSH terms, in addition to "American shoulder and elbow surgeon" or "ASES." We selectively included primary investigations that assessed factors linked to the failure to achieve MCID for the ASES score subsequent to orthopedic shoulder procedures, while excluding papers addressing anatomical, surgical, or injury-related aspects. RESULTS: Our analysis identified 149 full-text articles, leading to the inclusion of 12 studies for detailed analysis. The selected studies investigated outcomes following various orthopedic shoulder procedures, encompassing biceps tenodesis, total shoulder arthroplasty, and rotator cuff repair. Notably, factors, such as gender, body mass index, diabetes, smoking habits, opioid usage, depression, anxiety, workers' compensation, occupational satisfaction, and the preoperative ASES score, were all associated with the inability to attain MCID. CONCLUSION: In summary, numerous factors exert a negative influence on the attainment of MCID following shoulder procedures, and these factors appear to be irrespective of the specific surgical technique employed. Patients presenting with these factors may perceive their surgical outcomes as less successful when compared to those without these factors. Identifying these factors can enable healthcare providers to provide more effective counseling to patients regarding their expected outcomes and rehabilitation course. Furthermore, these findings can aid in the development of a screening tool to better identify these risk factors and optimize them before surgery.

Ultrasound-determined healing rates with subscapularis tenotomy versus peel after anatomic shoulder arthroplasty.

BACKGROUND: Several techniques have been described for mobilizing the subscapularis tendon in anatomic total shoulder arthroplasty (TSA). The purpose of this study was to compare subscapularis tendon healing rates, as determined by ultrasound, in patients following anatomic TSA with either a subscapularis tenotomy or subscapularis peel. METHODS: This study was a secondary analysis of patients from a previous randomized controlled trial in which patients underwent anatomic TSA and were randomized to either a tenotomy or peel approach. The primary outcome was postoperative tendon healing rates determined on ultrasound at >12 months after surgery. Secondary outcomes included postoperative tendon thickness measured on ultrasound; elbow position (neutral alignment in the belly-press position vs. posterior); internal rotation function measured with the third and fourth questions of the American Shoulder and Elbow Surgeons questionnaire; and Western Ontario Osteoarthritis of the Shoulder index. Radiographs were analyzed in patients with torn tendons. RESULTS: One hundred patients were randomized to a tenotomy (n = 47) or peel (n = 53) approach. Postoperative ultrasound results were available in 88 patients. Tendon healing rates were 95% for tenotomy vs. 75% for peel (P = .011). The mean postoperative tendon thickness was 4 mm (standard deviation, 1.0 mm) and 4 mm (standard deviation, 1 mm) in the tenotomy and peel groups, respectively (P = .37). Internal rotation function was not associated with healing status (P = .77 and P = .22 for questions 3 and 4, respectively, of the American Shoulder and Elbow Surgeons questionnaire), nor was elbow position (P = .2) in the belly-press position. DISCUSSION: We observed that subscapularis tenotomy had a higher healing rate than peel as determined by ultrasound in TSA patients. There was no statistically significant difference in postoperative tendon thickness in intact tendons as measured on ultrasound when comparing subscapularis mobilization techniques, nor was there any association between healing status and internal rotation function or elbow position.

Discerning a smile - The intricacies of analysis of post-neck dissection asymmetry.

INTRODUCTION: Iatrogenic facial nerve palsy is distressing to the patient and clinician. The deformity is aesthetically displeasing, and can be functionality problematic for oral competence, dental lip trauma and speech. Furthermore such injuries have litigation implications. Marginal mandibular nerve (MMN) palsy causes an obvious asymmetrical smile. MMN is at particular risk during procedures such as rhytidoplasties, mandibular fracture, tumour resection and neck dissections. Cited causes for the high incidence are large anatomical variations, unreliable landmarks, an exposed neural course and tumour grade or nodal involvement dictating requisite nerve sacrifice. An alternative cause for post-operative asymmetry is damage to the cervical branch of the facial nerve or platysmal dysfunction due to its division. The later tends to have a transient course and recovers. Distinction between MMN palsy and palsy of the cervical branch of the facial nerve or platysma division should therefore be made. In 1979 Ellenbogen differentiated between MMN palsy and "Pseudo-paralysis of the mandibular branch of the facial nerve". Despite this, there is paucity in the literature & confusion amongst clinicians in distinguishing between these palsies, and there is little regarding these post-operative sequelae and neck dissections. METHOD: This article reflects on the surgical anatomy of the MMN and cervical nerve in relation to danger zones during lymphadenectomy. The authors review the anatomy of the smile. Finally, case studies are utilised to evaluate the differences between MMN palsy and its pseudo-palsy to allow clinical differentiation. CONCLUSION: Here we present a simple method for clinical differentiation between these two prognostically different injuries, allowing appropriate reassurance, ongoing therapy & management.

Position statement: nonoperative management of lateral epicondylitis in adults.

We sought to compare methods of nonsurgical treatment of lateral epicondylitis in men and women older than 18 years to develop a guideline intended for orthopedic surgeons and other health care providers who assess, counsel and care for these patients. We searched Medline, Embase and Cochrane through to Mar. 9, 2021, and included all English-language studies comparing nonsurgical approaches. We compared physiotherapy versus no active treatment, corticosteroids versus placebo, platelet-rich plasma (PRP) versus placebo, and autologous blood injection versus placebo. Outcomes of interest were pain outcomes (visual analogue scale scores) and functional outcomes. We rated the quality of the evidence and strength of recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. This guideline will benefit patients seeking nonsurgical intervention for lateral epicondylitis by improving counselling on nonsurgical treatment options and possible outcomes. It will also benefit surgical providers by improving their knowledge of various nonsurgical approaches. Data presented could be used to develop frameworks and tools for shared decision-making.

Association of prurigo nodularis and infectious disease hospitalizations: a national cross-sectional study.

BACKGROUND: Prurigo nodularis (PN) is associated with a variety of systemic comorbidities, including infectious diseases such as HIV and viral hepatitis. There are limited data on other infectious disease comorbidities in patients with PN. AIM: To characterize infectious disease hospitalizations among patients with PN and the associated cost burden. METHODS: We searched the 2016-2017 National Inpatient Sample, a cross-sectional sample of 20% of all US hospitalizations, for infectious disease hospitalizations among patients with PN. Associations of PN with infections and related costs were determined using multivariable logistic and linear regression, adjusting for age, race, sex and insurance type. RESULTS: PN was associated with any infection overall (OR = 2.98, 95% CI 2.49-3.56), and with HIV, cutaneous, hepatobiliary, central nervous system, bacterial, viral and fungal/parasitic infections and for sepsis. Patients with PN had a higher mean cost of care (US$11 667 vs. US$8893, P < 0.001) and length of stay (5.5 vs. 4.2 days, P < 0.001) for any infection overall and for 7 of 13 other infections. Adjusting for age, race, sex and insurance coverage, PN was associated with higher cost (+30%, 95% CI +17 to +44%) and higher length of stay (+30%, 95% CI +18 to +44%) for any infection overall, and for several specific infections. These associations remained with alternate regression models adjusting for severity of illness. CONCLUSION: There is a high infectious disease burden among patients with PN, corresponding to higher healthcare utilization and spending. Clinicians must be aware of these associations when treating these patients with immunomodulatory drugs.

The Use of Elbow Arthroscopy for Management of the Pediatric Elbow: A Systematic Review of Indications and Outcomes.

PURPOSE: The purpose of this review was to systematically examine the literature surrounding elbow arthroscopy for pediatric patients and to assess indications, functional outcomes, and complication rates. METHODS: This systematic review was carried out in accordance with PRISMA guidelines. EMBASE, PubMed, and MEDLINE were searched for relevant literature from inception until December 2019, and studies were screened by 2 reviewers independently and in duplicate for those investigating elbow arthroscopy in a pediatric population (<18 years). Editorials, review articles, and case reports were excluded. Demographic data and data on surgical indications, treatment outcomes, and complications were recorded. A methodological quality assessment was performed for all included studies using the Methodological Index for Non-Randomized Studies. RESULTS: Overall, 19 studies, all of level IV evidence, were identified with a total of 492 patients (513 elbows). The patient population was 22.3% female with a mean age of 14.0 years (range, 4.0-15.7) and a mean follow-up time of 33.0 months (range, 7.4-96 months). Twelve studies (263 patients) exclusively recruited patients with osteochondritis dissecans (OCD), although other indications for elbow arthroscopy included arthrofibrosis (50 patients), elbow fracture (37 patients), medial ulnar collateral ligament injury (31 patients), and posterior impingement (17 patients). All 13 reporting studies showed a significant improvement in the elbow flexion-extension arc, and 4 of 5 that reported a functional outcome score before and after surgery demonstrating a significant improvement. Last, the overall complication rates ranged from 0% to 23.8%, with a total of 8 instances of neurological injury (5 ulnar, 2 radial, 1 unspecified), all being transient and resolving within 3 to 6 months. CONCLUSION: Although elbow arthroscopy is primarily being performed for OCD in children and adolescents, there is evidence surrounding several other potential indications. Case series published to date have demonstrated significant improvements in functional outcomes and low rates of major complications. LEVEL OF EVIDENCE: Level IV, systematic review of level IV studies.

A ring system detected around the Centaur (10199) Chariklo.

Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ± 9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.

A randomized controlled trial comparing subscapularis tenotomy with peel in anatomic shoulder arthroplasty.

BACKGROUND: Controversy exists regarding the optimal technique of subscapularis tendon mobilization during anatomic shoulder arthroplasty. The purpose of this prospective, randomized, double-blind study was to compare internal rotation strength in the belly-press position and functional outcomes between the subscapularis tenotomy and subscapularis peel approaches during shoulder arthroplasty. METHODS: Patients undergoing anatomic shoulder arthroplasty were randomized to either a tenotomy or peel approach. The primary outcome was internal rotation strength in the belly-press position, measured by an electronic handheld dynamometer at 24 months postoperatively. Secondary outcomes included the Western Ontario Osteoarthritis of the Shoulder (WOOS) index score, American Shoulder and Elbow Surgeons (ASES) score, range of motion, radiographic lucencies, and adverse events. RESULTS: We randomized 100 patients to subscapularis tenotomy (n = 47) or peel (n = 53). Eighty-one percent of the cohort returned for 24 months' follow-up. Compared with baseline measures, mean internal rotation strength in the belly-press position and WOOS and ASES scores improved in both groups at final follow-up (P < .0001). Intention-to-treat analysis for internal rotation strength at 24 months revealed no significant difference (P = .57) between tenotomy (mean, 4.9 kg; SD, 3.8 kg) and peel (mean, 5.4 kg; SD, 3.9 kg). Comparison of WOOS and ASES scores demonstrated no significant differences between groups at any time point. The healing rates by ultrasound were 72% for tenotomy and 71% for peel (P = .99). DISCUSSION: No statistically significant difference in internal rotation strength was identified between the tenotomy and peel groups. The secondary outcomes were not significantly different between groups.

Ramsey Spectroscopy with Displaced Frequency Jumps.

Sophisticated Ramsey-based interrogation protocols using composite laser pulse sequences have been recently proposed to provide next-generation high-precision atomic clocks with a near perfect elimination of frequency shifts induced during the atom-probing field interaction. We propose here a simple alternative approach to the autobalanced Ramsey interrogation protocol and demonstrate its application to a cold-atom microwave clock based on coherent population trapping (CPT). The main originality of the method, based on two consecutive Ramsey sequences with different dark periods, is to sample the central Ramsey fringes with frequency jumps finely adjusted by an additional frequency-displacement concomitant parameter, scaling as the inverse of the dark period. The advantage of this displaced frequency-jump Ramsey method is that the local oscillator (LO) frequency is used as a single physical variable to control both servo loops of the sequence, simplifying its implementation and avoiding noise associated with controlling the LO phase. When tested using a CPT cold-atom clock, the DFJR scheme reduces the sensitivity of the clock frequency to variations of the light shifts by more than an order of magnitude compared with the standard Ramsey interrogation. This simple method can be applied in a wide variety of Ramsey-spectroscopy based applications including frequency metrology with CPT-based and optical atomic clocks, mass spectrometry, and precision spectroscopy.

Generation of transgenic goats by pronuclear microinjection: a retrospective analysis of a commercial operation (1995-2012).

Production of transgenic founder goats involves introducing and stably integrating an engineered piece of DNA into the genome of the animal. At LFB USA, the ultimate use of these transgenic goats is for the production of recombinant human protein therapeutics in the milk of these dairy animals. The transgene or construct typically links a milk protein specific promoter sequence, the coding sequence for the gene of interest, and the necessary downstream regulatory sequences thereby directing expression of the recombinant protein in the milk during the lactation period. Over the time period indicated (1995-2012), pronuclear microinjection was used in a number of programs to insert transgenes into 18,120, 1- or 2- cell stage fertilized embryos. These embryos were transferred into 4180 synchronized recipient females with 1934 (47%) recipients becoming pregnant, 2594 offspring generated, and a 109 (4.2%) of those offspring determined to be transgenic. Even with new and improving genome editing tools now available, pronuclear microinjection is still the predominant and proven technology used in this commercial setting supporting regulatory filings and market authorizations when producing founder transgenic animals with large transgenes (> 10 kb) such as those necessary for directing monoclonal antibody production in milk.

Open reduction internal fixation vs non-operative management in proximal humerus fractures: a prospective, randomized controlled trial protocol.

BACKGROUND: Proximal humerus fractures are the third most common fracture in the elderly population and are expected to increase due to the aging population. Surgical fixation with locking plate technology has increased over the last decade despite a lack of proven superiority in the literature. Three previous randomized controlled trials have not shown a difference in patient-centered outcomes when comparing non-operative treatment with open reduction and internal fixation. Low patient enrollment and other methodological concerns however limit the generalizability of these conclusions and as a result, management of these fractures remains a controversy. By comparing the functional outcomes of locked plate surgical fixation versus non-operative treatment of displaced three and four-part proximal humerus fractures in the elderly population with a large scale, prospective, multi-centered randomized controlled trial, the optimal management strategy for this common injury may be determined. METHODS: We will conduct a prospective, single blind randomized controlled parallel arm trial to compare non-operative management of proximal humerus fractures with open reduction and internal fixation using locked plating technology. One-hundred and sixty patients > age 60 with acute 3- or 4- part proximal humerus fractures will be randomized to either open reduction and internal fixation with locked plating technology or non-operative management treatment arms. The primary outcome measure is the Constant Score at 24 months post-operative. Secondary outcome measures include the American Shoulder and Elbow Surgeon's Score (ASES), EuroQol EQ-5D-5 L Health Questionnaire Score, short form PROMIS upper extremity score and IPAQ for the elderly score. Further outcome measures include assessment of the initial classification, displacement and angulation and the quality of surgical reduction via a standard computed tomography (CT) scan; rates of non-union, malunion, arthrosis, osteopenia or other complications including infection, nerve injury, intra-articular screw penetration, reoperation rates and hospital re-admission rates. DISCUSSION: The results of this trial will provide Level 1 evidence to guide decision-making in the treatment of proximal humerus fractures in the elderly population. TRIAL REGISTRATION: ClinicalTrials.gov NCT02362100 . Registered 5 Feb 2015.

In vivo anticancer activity of rhomboidal Pt(II) metallacycles.

The development of novel antitumor agents that have high efficacy in suppressing tumor growth, have low toxicity to nontumor tissues, and exhibit rapid localization in the targeted tumor sites is an ongoing avenue of research at the interface of chemistry, cancer biology, and pharmacology. Supramolecular metal-based coordination complexes (SCCs) have well-defined shapes and geometries, and upon their internalization, SCCs could affect multiple oncogenic signaling pathways in cells and tissues. We investigated the uptake, intracellular localization, and antitumor activity of two rhomboidal Pt(II)-based SCCs. Laser-scanning confocal microscopy in A549 and HeLa cells was used to determine the uptake and localization of the assemblies within cells and their effect on tumor growth was investigated in mouse s.c. tumor xenograft models. The SCCs are soluble in cell culture media within the entire range of studied concentrations (1 nM-5 µM), are nontoxic, and showed efficacy in reducing the rate of tumor growth in s.c. mouse tumor xenografts. These properties reveal the potential of Pt(II)-based SCCs for future biomedical applications as therapeutic agents.

Pharmacokinetics of an extended-release formulation of eprinomectin in healthy adult alpacas and its use in alpacas confirmed with mange.

The study objective was to determine the pharmacokinetics and clinical effects of an extended-release 5% eprinomectin formulation (Longrange® ) following subcutaneous (s.c.) injection in healthy (n = 6) and mange-infected (n = 4) adult alpacas. High-performance liquid chromatography was used to analyze plasma samples obtained at regular intervals for 161 days following a single 5 mg/kg injection s.c. in healthy alpacas, and for 5 days following each dose (3 treatments, 2 months apart) in mange-affected animals. Skin scrapings and biopsies were performed pre- and post-treatment at two comparable sites in alpacas with mange. Four alpacas served as healthy controls. Eprinomectin plasma concentrations showed a biphasic peak (CMAX -1: 5.72 ± 3.25 ng/mL; CMAX -2: 6.06 ± 2.47 ng/mL) in all animals at 3.88 ± 5.16 days and 77 ± 12.52 days, respectively. Eprinomectin plasma concentrations remained above 1.27 ± 0.96 ng/mL for up to 120 days. Hematocrit (35.8 vs. 31.3%, P < 0.003) and albumin (3.5 vs. 2.8 g/dL P < 0.006) reduced significantly over 6 months in multidose animals, while fecal egg counts did not differ between groups. Self-limiting injection site reactions occurred in 9 of 10 animals. Pre- and post-treatment skin biopsies showed reduced hyperkeratosis, but increased fibrosis, with 1 of 4 alpacas remaining positive on skin scraping for mange. In conclusion, alpacas require a higher eprinomectin dose (5.0 mg/kg s.c.) than cattle, to reach comparable plasma concentrations.

Formation of asteroid pairs by rotational fission.

Pairs of asteroids sharing similar heliocentric orbits, but not bound together, were found recently. Backward integrations of their orbits indicated that they separated gently with low relative velocities, but did not provide additional insight into their formation mechanism. A previously hypothesized rotational fission process may explain their formation-critical predictions are that the mass ratios are less than about 0.2 and, as the mass ratio approaches this upper limit, the spin period of the larger body becomes long. Here we report photometric observations of a sample of asteroid pairs, revealing that the primaries of pairs with mass ratios much less than 0.2 rotate rapidly, near their critical fission frequency. As the mass ratio approaches 0.2, the primary period grows long. This occurs as the total energy of the system approaches zero, requiring the asteroid pair to extract an increasing fraction of energy from the primary's spin in order to escape. We do not find asteroid pairs with mass ratios larger than 0.2. Rotationally fissioned systems beyond this limit have insufficient energy to disrupt. We conclude that asteroid pairs are formed by the rotational fission of a parent asteroid into a proto-binary system, which subsequently disrupts under its own internal system dynamics soon after formation.

A randomized, double-blind sham-controlled trial on the efficacy of arthroscopic tennis elbow release for the management of chronic lateral epicondylitis.

BACKGROUND: Tennis elbow is a common elbow pathology typically affecting middle-aged individuals that can lead to significant disability. Most cases resolve within 2 years of symptom onset, but a subset of patients will develop persistent symptoms despite appropriate conservative management. There are several surgical approaches used to treat chronic tennis elbow, with arthroscopic surgery becoming an increasingly popular approach to address this pathology in North America. This procedure involves the arthroscopic release of the extensor carpi radialis brevis tendon (ECRB) origin at the elbow. The potential benefit of arthroscopic treatment of this condition is improved patient outcomes and shorter recovery time following surgery. The results of this technique have been reported only in the context of case series, which have shown positive results. However, in order to justify its widespread use and growing popularity, a high level of evidence study is required. The purpose of this prospective, randomized sham-controlled trial is to determine whether arthroscopic tennis elbow release is effective at treating chronic lateral epicondylitis. METHODS: We will conduct a prospective single center, double-blind, randomized sham-controlled parallel arm trial evaluating the efficacy of arthroscopic tennis elbow release in adult patients with symptoms for at least 6 months. Patients will undergo intraoperative randomization after diagnostic arthroscopy of the elbow to receive either ECRB release (through the creation of a lateral portal) or a sham lateral portal and no ECRB release. The primary outcome will be the Mayo Elbow Performance Score (MEPS) at 1 year follow-up. Secondary outcomes will be the abbreviated Disability of the Shoulder and Hand (DASH) score, American Shoulder and Elbow Surgeons elbow (ASES-e) score and grip strength at 3, 6, 12 and 24 months as well as return-to-work time, ability to return to full duty and adverse outcomes. DISCUSSION: Results of this study will provide empirical high quality evidence to guide clinical decision-making in patients with chronic tennis elbow. TRIAL REGISTRATION: NCT02236689 (September 8, 2014).

Obesity is associated with more activated neutrophils in African American male youth.

BACKGROUND: There is emerging evidence suggesting the role of peripheral blood leukocytes in the pathogenesis of obesity and related diseases. However, few studies have taken a genome-wide approach to investigating gene expression profiles in peripheral leukocytes between obese and lean individuals with the consideration of obesity-related shifts in leukocyte types. METHOD: We conducted this study in 95 African Americans (AAs) of both genders (age 14-20 years, 46 lean and 49 obese). Complete blood count with differential test (CBC) was performed in whole blood. Genome-wide gene expression analysis was obtained using the Illumina HumanHT-12 V4 Beadchip with RNA extracted from peripheral leukocytes. Out of the 95 participants, 64 had neutrophils stored. The validation study was based on real-time PCR with RNA extracted from purified neutrophils. RESULTS: CBC test suggested that, in males, obesity was associated with increased neutrophil percentage (P=0.03). Genome-wide gene expression analysis showed that, in males, the majority of the most differentially expressed genes were related to neutrophil activation. Validation of the gene expression levels of ELANE (neutrophil elastase) and MPO (myeloperoxidase) in purified neutrophils demonstrated that the expression of these two genes--important biomarkers of neutrophils activation--were significantly elevated in obese males (P=0.01 and P=0.02, respectively). CONCLUSION: The identification of increased neutrophil percentage and activation in obese AA males suggests that neutrophils have an essential role in the pathogenesis of obesity-related disease. Further functional and mechanistic studies on neutrophils may contribute to the development of novel intervention strategies reducing the burden associated with obesity-related health problems.

Proper placement of the distal biceps tendon during repair improves supination strength--a biomechanical analysis.

BACKGROUND: Anatomic repair of the distal biceps tendon can be difficult to achieve. This study was designed to compare the effect of anatomic and nonanatomic repairs on forearm supination torque. A nonanatomic repair re-establishes the footprint radial and more anterior to the tuberosity apex, whereas an anatomic repair re-establishes the footprint ulnar and more posterior to the tuberosity apex. METHODS: Eight fresh frozen cadaver arms were surgically prepared and mounted on an elbow simulator. Controlled loads were applied to the long head and short head in positions of pronation, neutral, and supination. This was done with intact tendons and then repeated with repaired tendons that were repaired either anatomically (ulnar position) or nonanatomically (radial position). RESULTS: All anatomic repairs showed no difference compared with intact tendon measurements. In comparing anatomic and nonanatomic repairs, we found no differences in the supination torque when the forearm was in 45° of pronation. However, when the arm was in neutral rotation, we found that 15% less supination torque was generated by the nonanatomic repair. When the arm was tested in 45° of supination, we found that 40% less supination torque was generated in the nonanatomic repair (P = .01). CONCLUSION: This study supports the idea that an anatomic repair of the biceps tendon onto the ulnar side of the radial tuberosity is important. If the tendon is repaired too radially, the biceps will lose the cam effect and may not be able to generate full supination torque when the forearm is in neutral rotation or in supination.

Responsive supramolecular polymer metallogel constructed by orthogonal coordination-driven self-assembly and host/guest interactions.

An emerging strategy for the fabrication of advanced supramolecular materials is the use of hierarchical self-assembly techniques wherein multiple orthogonal interactions between molecular precursors can produce new species with attractive properties. Herein, we unify the spontaneous formation of metal-ligand bonds with the host/guest chemistry of crown ethers to deliver a 3D supramolecular polymer network (SPN). Specifically, we have prepared a highly directional dipyridyl donor decorated with a benzo-21-crown-7 moiety that undergoes coordination-driven self-assembly with a complementary organoplatinum acceptor to furnish hexagonal metallacycles. These hexagons subsequently polymerize into a supramolecular network upon the addition of a bisammonium salt due to the formation of [2]pseudorotaxane linkages between the crown ether and ammonium moieties. At high concentrations, the resulting 3D SPN becomes a gel comprising many cross-linked metallohexagons. Notably, thermo- and cation-induced gel-sol transitions are found to be completely reversible, reflecting the dynamic and tunable nature of such supramolecular materials. As such, these results demonstrate the structural complexity that can be obtained when carefully controlling multiple interactions in a hierarchical fashion, in this case coordination and host/guest chemistry, and the interesting dynamic properties associated with the materials thus obtained.

Anatomic repair of the distal biceps tendon cannot be consistently performed through a classic single-incision suture anchor technique.

BACKGROUND: Distal biceps tendon ruptures commonly occur in active men, and surgical repair through a single-incision technique using suture anchors has become common. The current study assessed whether an anatomic repair of the biceps to the radial tuberosity can be consistently achieved through a single-incision technique. METHODS: Acute distal biceps tendon repairs using the single-incision technique were retrospectively reviewed. Computed tomography (CT) scans were obtained to investigate tuberosity dimensions and the position of the suture anchors. An isokinetic dynamometer was used to obtain flexion and supination strength. Disabilities of the Arm, Shoulder and Hand (DASH) scores were collected. RESULTS: CT scans were performed in 27 patients, of which, 21 underwent strength testing. The suture anchor placement averaged 50° radial to the apex of the tuberosity. Strength testing showed flexion strength of the repaired side was equal (97%-106%) to the normal side. Supination strength (80%-86%) and work (66%-75%) performed were both weaker on the repaired side (66%-75%; P < .05). The average DASH score was 10.7. CONCLUSIONS: Ideal suture anchor placement, in the ulnar aspect of the tuberosity, could not be reliably achieved through this single-incision technique. This could have clinical importance because supination strength was not fully restored in this group of patients.