Microstructural Changes of Tensor Fasciae Latae and Gluteus Medius Muscles Following Total Hip Arthroplasty: A Prospective Trial

PURPOSE OF THE STUDY Although total hip arthroplasty (THA) is one of the most successful orthopedic operations, the soft tissue trauma towards the periarticular musculature during surgical approaches remains a critical concern. However, the actual microstructural proof of muscle trauma on the level of the myofiber due to the surgical approach has never been claimed. MATERIAL AND METHODS Patients undergoing THA were prospectively enrolled and either operated by a direct lateral (DL) or a anterolateral minimally invasive approach (ALMI). Intraoperatively and at 6 months follow-up a needle biopsy was taken from the gluteus medius muscle and the tensor fasciae latae. Pre- and post-operative fiber diameter and composition, of gluteal medius muscle (GMM) and the tensor fasciae latae muscle (TFLM) were compared in both surgical approaches. RESULTS A total of 19 patients (12 F; 7 M) were included in this study. The average pre-operative fiber diameter or fiber type composition did not differ significantly in the GMM and TFLM, nor did it vary among patients with different approaches. The muscle fiber diameter significantly increased post-operatively in the TFLM, in both, the DL (p = 0.043) and the ALMI (p = 0.043) approach. There was a trend towards more pronounced muscle fiber changes in the DL (TFLM: p = 0.077; GMM: p = 0.150), compared to the ALMI. DISCUSSION AND CONCLUSIONS Our results show microstructural changes to the periarticular musculature following THA by a compensatory hypertrophy of the TFLM and GMM. These adaptions directly next to the surgical trauma were observed in DL and AMLI. Key words: total hip arthroplasty, skeletal muscle, muscle biopsy, iatrogenic trauma, muscle scar.

Safety, efficacy and repeatability of a novel house dust mite allergen challenge technique in the Fraunhofer allergen challenge chamber

BACKGROUND

Efficacy testing of immunotherapy in field studies is often hampered by variation of airborne allergens. Standardized allergen exposure in challenge chamber settings might be an alternative. Therefore, we developed a universal technique to create an atmosphere loaded with allergen particles of adjustable size from aqueous solutions of licensed allergen extracts.

OBJECTIVE

The aim of this study was to apply this technique and test the safety and efficacy of challenges with house dust mite (HDM) allergen in the Fraunhofer allergen challenge chamber.

METHODS

Aerosol particles carrying HDM allergen were produced by spray-drying of an aqueous solution containing HDM allergen and lactose. In a monocenter, placebo-controlled, single-blind, dose-escalation pilot study, 18 subjects with perennial allergic rhinitis and sensitization to HDM were exposed to HDM allergen for 4 h at either 250, 500, 1000 SQE/m³ or lactose alone (0 SQE/m³ ) 7 days apart. The dose of 500 SQE/m³ was repeated to investigate reproducibility. Total nasal symptom score (TNSS) was the primary endpoint.

RESULTS

Exposure to HDM increased TNSS (mean ± SD) to 3.4 ± 1.8, 3.3 ± 2.1, and 3.6 ± 2.0 at 250, 500 and 1000 SQE/m³ , respectively, while lactose alone did not change TNSS (0.7 ± 0.6). The results were reproducible at 500 SQE/m³ . Pulmonary function and adverse event frequency did not change with escalation of allergen dose.

CONCLUSION

This HDM allergen particle generation is safe, specific and reproducible and can therefore be used for efficacy testing of immunotherapy and for basic clinical research.

Speckle-Tracking-Based Evaluation of Vascular Strain at Different Sites of the Arterial Tree in Healthy Adults

Purpose: Vascular ultrasound (US) allows the analysis of vascular strain by speckle-tracking. This study sought to assess the extent to which vas cular strain varies between different segments of the arterial tree. Furthermore, this study aimed to investigate the reproducibility of vascular strain determination as well as of the components that contribute to the variance of vascular strain measurements in different vascular beds. Materials and Methods: Speckle-tracking was used to determine the vascular strain of the abdominal aorta (AA), the common carotid artery (CCA), the common femoral (CFA) and the popliteal artery (PA) of healthy adults. Intra- and interday reproducibility and the components of variance of vascular strain of the respective arteries were determined. Results: A total of 589 US clips obtained in 10 healthy adults (7 males, 28.3 ± 3.2 years) were analyzable. Vascular strain was 7.2 ± 3.0 % in the AA, 5.7 ± 2.1 % in the CCA, 2.1 ± 1.1 % in the CFA and 1.9 ± 1.1 % in the PA. The intraday coefficients of variation of vascular strain were 6.2 % (AA), 3.9 % (CCA), 3.3 % (CFA) and 6.1 % (PA), and the interday coefficients of variation were 5.9 % (AA), 8.4 % (CCA), 10 % (CFA) and 4.6 % (PA). The variance of vascular strain mainly depended on the investigated vessel and subject. Individual DUS clips, the day of examination and the (right/left) body side (in paired arteries) had no impact on the variance of vascular strain. Conclusion: Vascular strain substantially varies between different sites of the arterial tree. Speckle-tracking by DUS allows the reliable determination of vascular strain at different arterial sites.

Endotoxin: physical requirements for cell activation

Lipopolysaccharide (LPS) is the eminent lipid component of the outer leaflet of the outer membrane of Gram-negative bacteria and the major initiator of innate immune response to bacterial infection. Below the critical micellar concentration (CMC), LPS is exclusively present as a monomer. Above this concentration, aggregates are formed. Increasing the concentration beyond the CMC leads to an increase in aggregate concentration, whereas the concentration of monomers remains constant or even decreases. The question how LPS activates immune cells and whether the aggregate or the monomer is the biologically active unit has been and still is controversial. To prepare clearly defined monomeric solutions, we utilized a dialysis set-up consisting of a donor and an acceptor chamber, separated by a dialysis diaphragm with a cut-off of 5 kDa, thus allowing only monomers to pass. Human mononuclear cells (MNCs) were then stimulated with equal concentrations of aggregates and monomers, respectively, of deep rough mutant LPS from Escherichia coli strain F515 (Re LPS) and TNF-α release was determined. In contrast to earlier and very recent work of others, we started with a preparation of aggregate-suspensions and pure monomer-solutions and show that monomers are significantly less active than aggregates in the absence and presence of serum proteins at identical concentrations. In our model, we propose that LPS aggregates are detected by membrane-associated LBP and intercalated into the cell membrane to bring LPS into close proximity to signaling proteins in the membrane, thus finally leading to cell activation. To support this model, we present data showing that LBP is indeed present in or at the cell membrane of human macrophages.

A double-sided fabrication process for intrafascicular parylene C based electrode arrays

After the development of a single-sided fabrication process for intrafascicular parylene C based electrode arrays tests showed that an increase in integration density can only be achieved by a double-side process. The process uses 25 μm thick platinum iridium foil, which is thinned down with the laser and sandwiched between two 10 μm thick parylene C layers. Utilizing a picosecond laser (355 nm Nd:YVO4) it was possible to fabricate 40 μm thick electrodes that can be implanted directly in the nerve without relying on additional support layers like chitosan or silk. The fabricated samples feature three 80 μm diameter electrodes on each side and a large ground electrode that is opened to both sides. Impedance mismatches from front to back side as a result of the fabrication process are compensated by electrochemical deposition of nanostructured platinum. This step makes it possible to bring the impedances of the small electrodes down to the range of just a few kΩ at 1 kHz and illustrate the additionally gained surface due to the picosecond laser ablation on the front side electrodes. The safely injectable charge per pulse was found to be 635.75 μC/cm2 for such coated electrodes. Optical investigations show that this fabrication process offers an alternative to established lithographic processes for thin and flexible electrode arrays in neural implants.

[Functional Results 3 Months after Implantation of an "Extended Range of Vision" Intraocular Lens]

PURPOSE

Evaluation of the visual and refractive results 3 months after implantation of a diffractive extended range of vision (ERV) intraocular lens (IOL) during cataract surgery.

METHODS

In a prospective multicentre study, patients with a calculated postoperative corneal astigmatism of ≤ 1.5 D received a diffractive ERV IOL (TECNIS Symfony, model ZXR00, Abbott Medical Optics, USA) during cataract surgery. After 3 months, the monocular and binocular corrected and uncorrected far, intermediate and near visual acuity, as well as refraction, were evaluated.

RESULTS

18 patients (36 eyes) with a mean age of 63.34 ± 4.6 years underwent bilateral cataract surgery. After 3 months, the binocular uncorrected distance visual acuity (UDVA) of logMAR was - 0.05 ± 0.11 and the corrected distance visual acuity (CDVA) of logMAR - 0.14 ± 0.05. Binocular uncorrected intermediate (UIVA) and near visual acuity (UNVA) were logMAR - 0.09 ± 0.02 and 0.19 ± 0.09, respectively. A target refraction of ± 0.75 D was reached by 89 % of the patients.

CONCLUSION

Implantation of an extended range of vision intraocular lens offers an effective way for visual rehabilitation at far and intermediate distances. Near vision is still in a functional range.

Serum Cholinesterase Levels Are Associated With 2-Year Ischemic Outcomes After Angioplasty and Stenting for Peripheral Artery Disease

PURPOSE

To prospectively investigate the associations of serum cholinesterase (CHE) levels with ischemic outcomes after angioplasty and stenting for lower limb peripheral artery disease (PAD).

METHODS

A prospective cohort study enrolled 108 patients with Rutherford category 2-3 ischemia who had successful primary unilateral angioplasty and self-expanding bare metal stent implantation for superficial femoral artery (SFA) stenosis. The primary endpoint was a composite of nonfatal myocardial infarction, nonfatal stroke or transient ischemic attack, cardiovascular death, or >80% target lesion restenosis within 2 years after peripheral angioplasty. Target lesion restenosis (restenosis endpoint) and the composite of the aforementioned atherothrombotic events (atherothrombotic endpoint) within 2-year follow-up were defined as secondary endpoints.

RESULTS

CHE levels were not available in 4 patients due to technical problems and 4 patients were lost to follow-up. The remaining 100 patients (median age 65 years; 62 men) met the minimum sample size requirement for statistical analysis. Median CHE levels were significantly lower in patients who subsequently experienced the primary endpoint compared with patients without ischemic events [7.1 (IQR 6.3-8.1) vs 8 (IQR 7-9.3) kU/L, p=0.007]. A CHE level <8.3 kU/L was identified as the best cutoff value to predict the primary endpoint, providing an 82.1% sensitivity and 44.3% specificity. The primary endpoint occurred significantly more often in patients with low CHE <8.3 kU/L than in patients with higher CHE levels (32 vs 7 patients, p=0.01). In multivariable Cox regression analysis, low CHE was associated with a 2.6-fold increased risk (95% CI 1.1 to 5.9, p=0.03) of the primary endpoint. Moreover, patients who suffered the secondary restenosis endpoint had significantly lower median CHE levels than patients without restenosis [7.1 (IQR 6.3-8.2) vs 7.9 (IQR 7-8.9) kU/L, p=0.02], and restenosis occurred more frequently in patients with low CHE compared with those with higher CHE levels (27 vs 7 patients, p=0.04).

CONCLUSION

Low CHE is associated with an increased risk of long-term adverse ischemic events following SFA angioplasty with stent implantation for PAD.

[Clinical Results After Implantation of a New Diffractive, Multifokal Intraocular Lens with a Reduced Near Add Power (+ 2.75 D)]

PURPOSE

Evaluation of the clinical data 3 months after implantation of a new diffractive multifocal intraocular lens (MIOL) with a reduced near add power of + 2.75 D.

METHODS

In a prospective study, patients who underwent cataract surgery or refractive lens exchange with implantation of an MIOL (Tecnis ZKB00, Abbott Medical Optics, Santa Ana, California, USA) were included. Three months postoperative corrected and uncorrected visual acuities at different distances were measured and evaluated. Those patients that underwent bilateral MIOL implantation additionally filled out a questionnaire 3 months postoperatively.

RESULTS

Between October 2013 and August 2014, 115 eyes of 62 patients were implanted with the ZKB00 IOL. Mean postoperative refractions were - 0.27 ± 0.44 D for the spherical equivalent, respectively. Mean binocular CDVA was - 0.01 ± 0.3 logMAR with a mean binocular UDVA of 0.06 ± 0.08 logMAR. For near distance in 40 cm, an UNVA of 0.07 ± 0.10 logMAR three months postoperatively was measured.

CONCLUSION

The ZKB00 IOL belongs to a group of novel MIOL with an increased intermediate visual performance. Our study shows good visual acuity at all distances, as well as a high rate of satisfaction and subjectively good image quality.

Robust set-point regulation for ecological models with multiple management goals

Population managers will often have to deal with problems of meeting multiple goals, for example, keeping at specific levels both the total population and population abundances in given stage-classes of a stratified population. In control engineering, such set-point regulation problems are commonly tackled using multi-input, multi-output proportional and integral (PI) feedback controllers. Building on our recent results for population management with single goals, we develop a PI control approach in a context of multi-objective population management. We show that robust set-point regulation is achieved by using a modified PI controller with saturation and anti-windup elements, both described in the paper, and illustrate the theory with examples. Our results apply more generally to linear control systems with positive state variables, including a class of infinite-dimensional systems, and thus have broader appeal.

Consensus on Recording Deep Endometriosis Surgery: the CORDES statement

STUDY QUESTION

Which essential items should be recorded before, during and after endometriosis surgery and in clinical outcome based surgical trials in patients with deep endometriosis (DE)?

SUMMARY ANSWER

A DE surgical sheet (DESS) was developed for standardized reporting of the surgical treatment of DE and an international expert consensus proposal on relevant items that should be recorded in surgical outcome trials in women with DE.

WHAT IS KNOWN ALREADY

Surgery is an important treatment for symptomatic DE. So far, data have been reported in such a way that comparison of different surgical techniques is impossible. Therefore, we present an international expert proposal for standardized reporting of surgical treatment and surgical outcome trials in women with DE.

STUDY DESIGN, SIZE, DURATION

International expert consensus based on a systematic review of literature.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Taking into account recommendations from Consolidated Standards of Reporting Trials (CONSORT), the Innovation Development Exploration Assessment and Long-term Study (IDEAL), the Initiative on Methods, Measurement and Pain Assessment in Clinical trials (IMMPACT) and the World Endometriosis Research Foundation Phenome and Biobanking Harmonisation Project (WERF EPHect), a systematic literature review on surgical treatment of DE was performed and resulted in a proposal for standardized reporting, adapted by contributions from eight members of the multidisciplinary Leuven University Hospitals Endometriosis Care Program, from 18 international experts and from audience feedback during three international meetings.

MAIN RESULTS AND THE ROLE OF CHANCE

We have developed the DESS to record in detail the surgical procedures for DE, and an international consensus on pre-, intra- and post-operative data that should be recorded in surgical outcome trials on DE.

LIMITATIONS, REASONS FOR CAUTION

The recommendations in this paper represent a consensus among international experts based on a systematic review of the literature. For several items and recommendations, high-quality RCTs were not available. Further research is needed to validate and evaluate the recommendations presented here.

WIDER IMPLICATIONS OF THE FINDINGS

This international expert consensus for standardized reporting of surgical treatment in women with DE, based on a systematic literature review and international consensus, can be used as a guideline to record and report surgical management of patients with DE and as a guideline to design, execute, interpret and compare clinical trials in this patient population.

STUDY FUNDING/COMPETING INTERESTS

None of the authors received funding for the development of this paper. M.A. reports personal fees and non-financial support from Bayer Pharma outside the submitted work; H.T. reports a grant from Pfizer and personal fees for being on the advisory board of Perrigo, Abbvie, Allergan and SPD.

TRIAL REGISTRATION NUMBER

N/A.

Phase stabilization of spatiotemporally multiplexed ultrafast amplifiers

Actively stabilized, simultaneous spatial and temporal coherent beam combination is a promising power-scaling technique for ultrafast laser systems. For a temporal combination based on optical delay lines, multiple stable states of operation arise for common stabilization techniques. A time resolved Jones' calculus is applied to investigate the issue. A mitigation strategy based on a temporally gated error signal acquisition is derived and demonstrated, enabling to stabilize laser systems with arbitrary numbers of amplifier channels and optical delay lines.

Differences in Medical and Life-style Risk Factors for Malnutrition in Limited-Resource Older Adults in a Rural U.S. State: A Descriptive Study

OBJECTIVES

Medical and life-style factors are associated with malnutrition in older adults. This study assessed the presence of these risk factors in limited-resource, community-dwelling older adults to inform the development of a nutrition education interventions.

DESIGN

Quantitative descriptive study.

SETTING

A total of 24 randomly selected congregate nutrition sites (where limited-resource older adults can receive one hot meal/day, five days/week) in the rural state of South Carolina, USA.

PARTICIPANTS

Data were collected from 477 older adults (of the 407 who reported race, 219 were African American and 171 were White).

MEASUREMENTS

Extension Educators who work for the Cooperative Extension Service (a formalized educational outreach system associated with some U.S. universities) read aloud a 27-item instrument designed to assess risk factors for malnutrition. Response frequencies were tabulated and chi-square tests were performed using SAS 9.3.

RESULTS

More African Americans reported having a chronic illness or condition (81.2 vs. 68.3%; p=0.003), eating alone (66.2 vs. 53.6%; p=0.012), having a refrigerator that sometimes did not keep food cold (31.8 vs. 8.4%; p<0.0001), and sometimes not having enough money to buy food (38.9 vs. 18.5%; p<0.0001) compared to White older adults.

CONCLUSION

Rural older adults who attend congregate nutrition sites, especially African Americans, could be at risk for malnutrition due to health status and food preparation-related factors. Evidence-based, tailored programs are needed to minimize malnutrition among limited-resource older adults living in rural areas in the U.S.

Relation of Nailfold Capillaries and Autoantibodies to Mortality in Patients With Raynaud Phenomenon

BACKGROUND

In incipient Raynaud phenomenon, nailfold capillaroscopy and autoantibody tests are obtained to screen for an emerging connective tissue disease. Whether the presence of abnormal nailfold capillaries and autoantibodies are related to mortality in patients with incipient Raynaud phenomenon is not known.

METHODS AND RESULTS

In 2958 consecutive patients (78% women, median age 45 years) with incipient Raynaud phenomenon without previously known connective tissue disease, nailfold capillaroscopy and laboratory tests for antinuclear antibodies (ANA) and ANA subsets were obtained at initial presentation. During a median follow-up period of 9.3 years, 227 women (9.9% of female patients) and 129 men (20% of male patients) with Raynaud phenomenon died. In comparison with a demographically matched standard population, survival was poorer in patients with Raynaud phenomenon (log-rank test P<0.0001). In patients with Raynaud phenomenon, mortality was higher in men than in women (P<0.0001, Cox proportional hazards model). In women, the presence of abnormal nailfold capillaries, ANA, and anti-Scl-70 antibodies were related to an increase in all-cause mortality. The conjoint presence of abnormal nailfold capillaries and autoantibodies was associated with the highest mortality rates. In men, abnormal nailfold capillaries, and ANA and ANA subsets, as well, were not related to survival. In both sexes, patients' age and serum creatinine were associated with mortality.

CONCLUSIONS

In Raynaud phenomenon, male sex, age, and serum creatinine are related to mortality. Abnormal nailfold capillaries and autoantibodies are associated with an increase in all-cause mortality in female patients, but not in male patients with Raynaud phenomenon.