Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges

Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury.     

Shoulder impairments and their association with symptomatic rotator cuff disease in breast cancer survivors

Over 2.6 million breast cancer survivors currently reside in the United States. While improvements in the medical management of women diagnosed with breast cancer have resulted in a 5-year survival rate of 89%, curative treatments are associated with a high prevalence of shoulder and arm morbidity, which, in turn, can negatively impact a woman’s quality of life. Breast cancer survivors frequently experience shoulder and arm pain, decreased range of motion, muscle weakness, and lymphedema. These symptoms can lead to difficulties with daily activities ranging from overhead reaching and carrying objects to caring for family and returning to work.Despite health care professionals awareness of these problems, a significant number of breast cancer survivors are confronted with long-term, restricted use of their affected shoulder and upper extremity. This problem may partially be explained by: (1) an incomplete understanding of relevant impairments and diagnoses associated with shoulder/arm pain and limited upper extremity use, and (2) the limited effectiveness of current rehabilitation interventions for managing shoulder pain and decreased upper extremity function in breast cancer survivors.Because breast cancer treatment directly involves the neuromusculoskeletal tissues of the shoulder girdle, it is understandable why breast cancer survivors are likely to develop shoulder girdle muscle weakness and fatigue, decreased shoulder motion, altered shoulder girdle alignment, and lymphedema. These impairments can be associated with diagnoses such as post-mastectomy syndrome, adhesive capsulitis, myofascial dysfunction, and brachial plexopathy, all of which have been reported among breast cancer survivors. It is our belief that these impairments also put women at risk for developing symptomatic rotator cuff disease.In this paper we set forth the rationale for our belief that breast cancer treatments and subsequent impairments of shoulder girdle neuromusculoskeletal tissues place breast cancer survivors at risk for developing symptomatic rotator cuff disease. Additionally, we identify knowledge gaps related to the current understanding of relevant shoulder girdle impairments and their association with symptomatic rotator cuff disease in breast cancer survivors. Ultimately, information from studies designed to meet these gaps will provide a scientific basis for the development of new, or refinement of existing, examination, intervention, and prevention techniques, which should lead to improved clinical outcomes in this population.     

A Large‐Scale Dissemination and Implementation Model for Evidence‐Based Treatment and Continuing Care

[Clin Psychol Sci Prac 18: 67–83, 2011] Multiple evidence‐based treatments for adolescents with substance use disorders are available; however, the diffusion of these treatments in practice remains minimal. A dissemination and implementation model incorporating research‐based training components for simultaneous implementation across 33 dispersed sites and over 200 clinical staff is described. Key elements for the diffusion of the Adolescent Community Reinforcement Approach and Assertive Continuing Care were as follows: (a) 3 years of funding to support local implementation; (b) comprehensive training, including a 3.5‐day workshop, biweekly coaching calls, and ongoing performance feedback facilitated by a web tool; (c) a clinician certification process; (d) a supervisor certification process to promote long‐term sustainability; and (e) random fidelity reviews after certification. Process data are summarized for 167 clinicians and 64 supervisors.     

Does questionnaire-based patient feedback reflect the important qualities of clinical consultations? Context, benefits and risks

Objective

To explore perceptions of clinical consultations and how they relate to questionnaire-based patient feedback.

Methods

Telephone interviews with 35 junior doctors and 40 general practice patients who had used the Doctors’ Interpersonal Skills Questionnaire (DISQ).

Results

Doctors and patients had similar views of ‘good consultations’ as relying on doctors’ listening and explaining skills. Preferences for a consultation style focused on an outcome or on the doctor-patient relationship may be independent of informational and/or affective consultation content. Respondents felt the important consultation elements were similar in different contexts, and so DISQ feedback would be useful in different settings. Benefits of feedback were identified in the form of patient empowerment and doctors’ learning. Risks were identified in the inappropriate use of feedback, both inadvertent and deliberate.

Conclusion

The style and content of consultations may be considered as separate dimensions, an approach that may help doctors adapt their communication appropriately to different consultations. Patient feedback focused on communication skills is appropriate, but there are potential risks.

Practice implications

Doctors should consider the transactional or relational preference of a patient in approaching a consultation. Patient feedback can deliver benefits to doctors and patients, but risks must be acknowledged and mitigated against.     

Participation of CD11c(+) leukocytes in methicillin-resistant Staphylococcus aureus clearance from the lung

Staphylococcus aureus causes especially severe pulmonary infection, associated with high morbidity and mortality. In addition to the effects of specific virulence factors, it appears that the intensity of the host proinflammatory response, particularly in the initial stages of infection, contributes substantially to pulmonary damage. We tested the hypothesis that the CD11c(+) leukocytes are important in the host response to pulmonary infection with methicillin-resistant S. aureus (MRSA) USA300. Clodronate-induced depletion of the alveolar macrophage population resulted in increased numbers of dendritic cells (DCs) and CD4(+) cells in bronchoalveolar lavage (BAL) fluid and was associated with significantly increased mortality by 18 h following S. aureus inoculation but had no effect on bacterial load or polymorphonuclear leukocyte (PMN) numbers in the lung. These clodronate-treated mice also had increased expression of interleukin-17A/F (IL-17A/F) and CXCL10 but not of gamma interferon (IFN-γ) or tumor necrosis factor (TNF). Depletion of the dendritic cell population in mice expressing a CD11c-enhanced green fluorescent protein (EGFP)-diphtheria toxin receptor (DTR) transgene was associated with an increased bacterial load in the lung but not increased mortality. Both DCs and airway epithelial cells produced CXCL9, -10, and -11 in response to S. aureus. Pretreatment of mice with an anti-CXCR3 antibody prior to inoculation with MRSA substantially reduced CD4(+) cells and decreased pulmonary inflammation at 18 h postinfection compared to pretreatment with an IgG control. The results of these experiments suggest that CD11c(+) cells, the induction of CXCR3 ligand expression, and subsequent CD4(+) cell recruitment have an important role in the pathogenesis of severe MRSA pulmonary infection.     

Assessing the readiness of black churches to engage in health disparities research

We assessed church readiness to engage in health disparities research using a newly developed instrument, examined the correlates of readiness, and described strategies that churches used to promote health. We pilot tested the instrument with churches in a church-academic partnership (n = 12). We determined level of readiness to engage in research and assessed correlates of readiness. We also conducted interviews with participating pastors to explore strategies they had in place to support research engagement. Churches scored fairly high in readiness (average of 4.04 out of 5). Churches with a pastor who promoted the importance of good nutrition in a sermon or had a budget for health-related activities had significantly higher readiness scores than churches without such practices. Having a tool to evaluate church readiness to engage in research will inform targeted technical assistance and research projects that will strengthen church-academic partnerships and improve capacity to address health disparities.