Non-uniform upregulation of the autogenic stretch reflex among hindlimb extensors following lateral spinal lesion in the cat.

Successful propagation throughout the step cycle is contingent on adequate regulation of whole-limb stiffness by proprioceptive feedback. Following spinal cord injury (SCI), there are changes in the strength and organization of proprioceptive feedback that can result in altered joint stiffness. In this study, we measured changes in autogenic feedback of five hindlimb extensor muscles following chronic low thoracic lateral hemisection (LSH) in decerebrate cats. We present three features of the autogenic stretch reflex obtained using a mechanographic method. Stiffness was a measure of the resistance to stretch during the length change. The dynamic index documented the extent of adaptation or increase of the force response during the hold phase, and the impulse measured the integral of the response from initiation of a stretch to the return to the initial length. The changes took the form of variable and transient increases in the stiffness of vastus (VASTI) group, soleus (SOL), and flexor hallucis longus (FHL), and either increased (VASTI) or decreased adaptation (GAS and PLANT). The stiffness of the gastrocnemius group (GAS) was also variable over time but remained elevated at the final time point. An unexpected finding was that these effects were observed bilaterally. Potential reasons for this finding and possible sources of increased excitability to this muscle group are discussed.

A microdosimetric analysis of the interactions of mono-energetic neutrons with human tissue.

Nuclear reactions induced during high-energy radiotherapy produce secondary neutrons that, due to their carcinogenic potential, constitute an important risk for the development of iatrogenic cancer. Experimental and epidemiological findings indicate a marked energy dependence of neutron relative biological effectiveness (RBE) for carcinogenesis, but little is reported on its physical basis. While the exact mechanism of radiation carcinogenesis is yet to be fully elucidated, numerical microdosimetry can be used to predict the biological consequences of a given irradiation based on its microscopic pattern of energy depositions. Building on recent studies, this work investigated the physics underlying neutron RBE by using the microdosimetric quantity dose-mean lineal energy (y‾D) as a proxy. A simulation pipeline was constructed to explicitly calculate the y‾D of radiation fields that consisted of (i) the open source Monte Carlo toolkit Geant4, (ii) its radiobiological extension Geant4-DNA, and (iii) a weighted track-sampling algorithm. This approach was used to study mono-energetic neutrons with initial kinetic energies between 1 eV and 10 MeV at multiple depths in a tissue-equivalent phantom. Spherical sampling volumes with diameters between 2 nm and 1 µm were considered. To obtain a measure of RBE, the neutron y‾D values were divided by those of 250 keV X-rays that were calculated in the same way. Qualitative agreement was found with published radiation protection factors and simulation data, allowing for the dependencies of neutron RBE on depth and energy to be discussed in the context of the neutron interaction cross sections and secondary particle distributions in human tissue.

Effects of partial maize silage substitution with microalgae on viscosity and biogas yields in continuous AD trials.

The microalga Acutodesmus obliquus was investigated as a feedstock in semi-continuously fed anaerobic digestion trials, where A. obliquus was co-digested with pig slurry and maize silage. Maize silage was substituted by both 10% and 20% untreated, and 20% ultrasonicated microalgae biomass on a VS (volatile solids) basis. The substitution of maize silage with 20% of either ultrasonicated and untreated microalgae led to significantly lower biogas yields, i.e., 560 dm³ kg-1 VScorr in the reference compared to 516 and 509 dm³ kg-1VScorr for untreated and ultrasonicated microalgae substitution. Further, the viscosities in the different reactors were measured at an OLR of 3.5 g VS dm-3 d-1. However, all treatments with microalgae resulted in significantly lower viscosities. While the mean viscosity reached 0.503 Pa s in the reference reactor, mean viscosities were 53% lower in reactors where maize was substituted by 20% microalgae, i.e. 0.239 Pa s, at a constant rotation speed of 30 rpm. Reactors where maize was substituted by 20% ultrasonicated microalgae had a 32% lower viscosity, for 10% microalgae substitution a decrease of 8% was measured. Decreased viscosities have beneficial effect on the bioprocess and the economy in biogas plants. Nonetheless, with regard to other parameters, no positive effect on biogas yields by partial substitution with microalgae biomass was found. The application of microalgae may be an interesting option in anaerobic digestion when fibrous or lignocellulosic substances lead to high viscosities of the digested slurries. High production costs remain the bottleneck for making microalgae an interesting feedstock.

Molecular epidemiology of multi- and extensively-drug-resistant Mycobacterium tuberculosis in Ireland, 2001-2014.

OBJECTIVES: The primary objective of this work was to examine the acquisition and spread of multi-drug resistant (MDR) tuberculosis (TB) in Ireland. METHODS: All available Mycobacterium tuberculosis complex (MTBC) isolates (n = 42), from MDR-TB cases diagnosed in Ireland between 2001 and 2014, were analysed using phenotypic drug-susceptibility testing, Mycobacterial-Interspersed-Repetitive-Units Variable-Number Tandem-Repeat (MIRU-VNTR) genotyping, and whole-genome sequencing (WGS). RESULTS: The lineage distribution of the MDR-TB isolates comprised 54.7% Euro-American, 33.3% East Asian, 7.2% East African Indian, and 4.8% Indo-Oceanic. A significant association was identified between the East Asian Beijing sub-lineage and the relative risk of an isolate being MDR. Over 75% of MDR-TB cases were confirmed in non-Irish born individuals and 7 MIRU-VNTR genotypes were identical to clusters in other European countries indicating cross-border spread of MDR-TB to Ireland. WGS data provided the first evidence in Ireland of in vivo microevolution of MTBC isolates from drug-susceptible to MDR, and from MDR to extensively-drug resistant (XDR). In addition, they found that the katG S315T isoniazid and rpoB S450L rifampicin resistance mutations were dominant across the different MTBC lineages. CONCLUSIONS: Our molecular epidemiological analyses identified the spread of MDR-TB to Ireland from other jurisdictions and its potential to evolve to XDR-TB.

Racial/ethnic subgroup differences in outcomes and acceptability of an Internet-delivered intervention for substance use disorders.

The Therapeutic Education System (TES), an Internet version of the Community Reinforcement Approach plus prize-based motivational incentives, is one of few empirically supported technology-based interventions. To date, however, there has not been a study exploring differences in substance use outcomes or acceptability of TES among racial/ethnic subgroups. This study uses data from a multisite (N = 10) effectiveness study of TES to explore whether race/ethnicity subgroups (White [n = 267], Black/African American [n = 112], and Hispanic/Latino [n = 55])moderate the effect of TES. Generalized linear mixed models were used to test whether abstinence, retention, social functioning, coping, craving, or acceptability differed by racial/ethnic subgroup. Findings demonstrated that race/ethnicity did not moderate the effect of TES versus TAU on abstinence, retention, social functioning, or craving. A three-way interaction (treatment, race/ethnicity, and abstinence status at study entry) showed that TES was associated with greater coping scores among nonabstinent White participants (p = .008) and among abstinent Black participants (p < .001). Acceptability of the TES intervention, although high overall, was significantly different by race/ethnicity subgroup with White participants reporting lower acceptability of TES compared to Black (p = .006) and Hispanic/Latino (p = .008) participants. TES appears to be a good candidate treatment among a diverse population of treatment-seeking individuals with substance use disorders.

True rifampicin resistance missed by the MGIT: prevalence of this pheno/genotype in the UK and Ireland after 18 month surveillance.

OBJECTIVES: To characterize rifampicin-resistant strains missed by the Mycobacteria Growth Indicator Tube (MGIT) 960 system but not by egg-based media in the UK and Ireland and to ascertain their prevalence. METHODS: All strains sent for second-line susceptibility testing were prospectively collected. Drug Susceptibility Testing was performed by Resistance Ratio (RR), Proportion Method (PM), MGIT 960 and MIC determination by microdilution. Rifampicin-resistance-conferring mutations were detected with line probe assays and sequencing. At the end of the study period, retrospective archived strains from 2010 to 2014 showing key mutations were analysed phenotypically and genotypically. RESULTS: Seventeen of 7234 prospective isolates were included. All of them were susceptible by MGIT. One was borderline by RR (MIC to rifampicin of 4 mg/L) and was resistant by PM. Eight were resistant and eight were highly resistant on RR. These 16 isolates had MICs between 1 and 8 mg/L on microdilution. With PM, 16/17 were susceptible to rifampicin. 17/17 had mutations in the rpoB gene. D516Y was the mutation most frequently found (13/17). Retrospectively, ten additional strains with key genotypes were found in our collection: 6/10 were susceptible in the MGIT and resistant in RR. Of the 27 studied strains, the MGIT only detected resistance in four. CONCLUSIONS: Rifampicin resistance is missed by the MGIT system. In the UK and Ireland the prevalence of these strains is low. The introduction of routine molecular testing would detect false susceptibility. Further research is needed to ascertain the role of these strains in clinical failure and their prevalence in other settings.

Blood: tests used to assess the physiological and immunological properties of blood.

The properties of blood and the relative ease of access to which it can be retrieved make it an ideal source to gauge different aspects of homeostasis within an individual, form an accurate diagnosis, and formulate an appropriate treatment regime. Tests used to determine blood parameters such as the erythrocyte sedimentation rate, hemoglobin concentration, hematocrit, bleeding and clotting times, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean cell volume, and determination of blood groups are routinely used clinically, and deviations outside the normal range can indicate a range of conditions such as anemia, pregnancy, dehydration, overhydration, infectious disease, cancer, thyroid disease, and autoimmune conditions, to mention a few. As these tests can be performed relatively inexpensively and do not require high levels of technical expertise, they are ideally suited for use in the teaching laboratory, enabling undergraduate students to link theory to practice. The practicals described here permit students to examine their own blood and that of their peers and compare these with clinically accepted normal ranges. At the end of the practicals, students are required to answer a number of questions about their findings and to link abnormal values to possible pathological conditions by answering a series of questions based on their findings.

A scoping review of the literature on the involvement of service users in personality disorder services.

BACKGROUND: Service user involvement is receiving increasing support from mental health policy makers, service planners and research commissioners. However, we lack a good understanding of the nature and extent to which service users are involved in personality disorder (PD) services and the effects of involvement in these services. OBJECTIVES: To review and appraise published sources; increase understanding about service user involvement in PD services; and highlight knowledge gaps and related issues. METHODS: A scoping review methodology was adopted. Data were 'charted' to illustrate the landscape of writings and views and a qualitative analysis synthesized the results in terms of key emergent themes. RESULTS: Only a small amount of published work was identified with significant gaps in the literature. Effects were reported mostly in terms processes and emotional and practical benefits for service users. Emergent themes were wellness and health, recruitment and support for service users. CONCLUSIONS: This scoping review uncovered a lack of published work despite service user involvement being a key strand of health policy. There is a need for outcomes-focused research regarding service user involvement. Successful user involvement in PD services requires attention to be focused on the context, recruitment, support and 'wellness' of service users.

The emerging role of IG-IMRT for palliative radiotherapy: a single-institution experience.

Many modern radiotherapy centers now have image-guided intensity-modulated radiotherapy (IG-IMRT) tools available for clinical use, and the technique offers many options for patients requiring palliative radiotherapy. We describe a single-institution experience with IG-IMRT for short-course palliative radiotherapy, highlighting the unique situations in which the technique can be most effectively used.

Total scalp radiation using image-guided IMRT for progressive cutaneous T cell lymphoma.

Modern radiotherapy has advanced dramatically over the past decade and it is now possible to focus radiotherapy with extreme precision. This allows the radiation dose to be targeted to the area(s) of tumour while sparing adjacent normal tissues even in seemingly complicated and difficult parts of the body. The case report presented here will illustrate how it is possible to irradiate the entire scalp for extensive cutaneous T cell lymphoma while minimising radiotherapy to the underlying brain, orbits and other critical structures.

Simultaneous treatment of multiple basal cell carcinoma lesions.

We present a rare case of advanced basal cell carcinoma where multiple large lesions, located on the anterior chest wall and back, were treated simultaneously using tomotherapy (TomoTherapy HiArt; TomoTherapy Inc, Madison, WI). A 74-year-old man presented with seven to eight separate extensive lesions on his body, some with a duration of 7 years or more. The image-guidance component of tomotherapy allowed daily verification of the position of the target and critical structures, enabling accurate targeting in the vicinity of sensitive critical structures. Intensity-modulated radiotherapy on a conventional linear accelerator would have required junctioning of multiple complex plans, owing to the large treatment area, and most likely sequential treatment strategies to target anterior and posterior lesions. Helical tomotherapy allowed the three largest lesions to be treated simultaneously and thus eliminated the need for multiple courses of treatment.

Study of quadrant high-dose intraoperative radiation therapy for early-stage breast cancer.

BACKGROUND: Partial breast irradiation has been tested in limited pilot studies and shown to provide acceptable cosmesis, minimal toxicity and adequate local control. The aim of this study was to determine the feasibility of using quadrant high-dose intraoperative radiation therapy (IORT) for the treatment of early-stage breast cancer. METHODS: Fifty-two women with early-stage breast cancer were treated with breast-conserving therapy and IORT between October 2002 and January 2006. The first 18 women received a radiation dose of 20 Gy. The protocol was then amended and the remaining 34 women were treated with 18 Gy. Each patient was evaluated after surgery, and at 3, 6 and 12 months; complications, toxicity and cosmetic outcomes were recorded by the breast surgeon. RESULTS: Women treated with 18 Gy appeared to have a more favourable cosmetic outcome compared with the earlier treatment group. At last follow-up, none of the women treated on the protocol had a breast recurrence. CONCLUSION: Experience suggests that this IORT technique is feasible, although further follow-up is necessary to assess its therapeutic value.

Poster - Thurs Eve-30: Investigation of a patient immobilization system for breast tomotherapy.

Using tomotherapy to deliver adjuvant radiation therapy for breast cancer treatment requires more precise immobilization than can be achieved using gravity alone. We evaluated the use of a thermoplastic shell to immobilize the patient's torso during breast cancer treatment. To measure intrafraction breathing motion, 4DCT scans were performed for eight post-lumpectomy or post-mastectomy breast cancer patients with the thermoplastic shell in place. The 4DCT scans were then analyzed to determine the magnitude of motion of the breast surface, chest wall, and heart over the breathing cycle. Maximum surface motion was typically less than 2mm, with a maximum of 4mm. Maximum displacement of the chest wall was less than 3mm with a maximum of 5mm in a single patient. Comparison with the setup errors recorded prior to repositioning the patients suggests that, with the thermoplastic shell in place, patient setup error will be a more significant source of uncertainty in patient position than breathing motion.

Comparison of upper limb volume measurement techniques and arm symptoms between healthy volunteers and individuals with known lymphedema.

Lymphedema is a problem for breast cancer survivors. The proliferation of limb measurement techniques makes it difficult to know how best to measure an at-risk limb. Using a sample of healthy volunteers and individuals with lymphedema, this study: 1) examined the relationship between more commonly used circumferential limb measurement methods and newer measurement methods of infrared laser perometry and bioelectrical impedance; 2) compared self-reported arm symptoms in healthy volunteers and breast cancer survivors with known lymphedema; and 3) explored the relationships among self-reported arm symptoms and circumferential tape measurement, infrared laser (perometry), and single and multi-frequency bioelectrical impedance. Lymphedema index ratios were calculated to allow comparison among measurement methods. Measurement methods correlated strongly with each other. Fourteen symptoms were reported by one or more participants in the lymphedema group while participants in the healthy volunteer group reported only eight symptoms over the same time frames. Using p < 0.001, all measurement methods correlated with self-reported arm swelling in the past year, while only circumferential and impedance measurements correlated with firmness. Future research needs to include serial arm measurements to explore arm volume variation in healthy and lymphedema volunteers and to further investigate possible lymphedema index ratios cut points as lymphedema diagnostic criteria.

A trend analysis of the relative value of blue dye and isotope localization in 2,000 consecutive cases of sentinel node biopsy for breast cancer.

BACKGROUND: Among the advocates of blue dye, isotope, or combined dye-isotope mapping of the sentinel lymph node (SLN) for breast cancer, there is no universal consensus as to which technique is optimal and whether the relative value of each method changes with increasing experience. The objective of this study was to examine the relative contributions of blue dye and radioisotope to successful identification of the SLN as the SLN-mapping technique evolved over our first 2,000 consecutive cases. STUDY DESIGN: Using the first 2,000 consecutive SLN biopsy procedures for breast cancer, performed by eight surgeons (none previously experienced in SLN techniques) at one institution, using a combined technique of blue dye and isotope mapping, we report the institutional learning curve and the relative contributions of dye and isotope to identifying both the SLN and the positive SLN, by increments of 500 cases. RESULTS: Comparing the first 500 with the most recent 500 cases, success in identifying the SLN by blue dye did not improve with experience, although success in isotope localization steadily increased, from 86% to 94% (p < 0.00005). With the increasing success of isotope mapping, the marginal benefit of blue dye (the proportion of cases in which the SLN was identified by blue dye alone) steadily declined, from 9% to 3% (p = 0.0001). Parallel to this trend, the proportion of positive SLNs identified by blue dye did not change with experience (89% to 90%), but isotope success steadily increased, from 88% to 98% (p = 0.0015). The proportion of positive SLNs identified by blue dye alone declined from 12% to 2% (p = 0.0015). CONCLUSIONS: Using a combined technique of blue dye and radioisotope mapping, and with refinement of the radioisotope technique, we report 97% success identifying the SLN. Although we continue to recommend the use of both methods in SLN mapping for breast cancer, we observe with experience a declining marginal benefit for blue dye.

Intradermal isotope injection is superior to intramammary in sentinel node biopsy for breast cancer.

BACKGROUND: The optimal sentinel lymph node (SLN) biopsy technique remains undefined in breast cancer. Injecting radiotracer or blue dye by a variety of routes seems to stage the axilla with comparable accuracy, and we have hypothesized that the dermal and the parenchymal lymphatics of the breast drain to the same SLN in most patients. Two previous studies from our institution support this concept: (1) a single-surgeon series of 200 consecutive SLN biopsy procedures demonstrating a high dye-isotope concordance for both intradermal (ID) and intraparenchymal (IP) isotope injection, and (2) a series of 100 procedures validated by a backup axillary dissection (ALND) in which the false-negative rate following ID isotope injection was comparable to that of our previous results with IP injection. Here, we directly compare the results of SLN biopsy using either ID or IP isotope injection for our entire experience of SLN biopsy procedures in which a backup ALND was done. METHODS: This is a retrospective, nonrandomized study of 298 clinical stage I to II breast cancer patients having SLN biopsy with a backup ALND planned in advance, comparing the results of ID (n = 164) and IP (n = 134) isotope injection. All patients had IP injection of blue dye. Endpoints included (1) successful SLN identification, (2) false-negative rate, (3) dye-isotope concordance, and (4) the SLN/axillary background isotope count ratio. RESULTS: ID isotope was more successful than IP, identifying the SLN in 98% versus 89% of cases, respectively. False-negative results (4.8% vs 4.4%) and dye-isotope concordance (92% vs 93%) were comparable between the 2 groups, and SLN/axillary background isotope count ratios were significantly higher with ID than with IP injection (288/1 vs 59/1). CONCLUSIONS: ID isotope injection identifies the SLN more often than IP, stages the axilla with comparable accuracy, and is associated with higher levels of SLN isotope uptake. The dermal and parenchymal lymphatics of the breast drain to the same axillary SLN in most breast cancer patients, and ID isotope injection is the procedure of choice in this setting.

Patient reluctance toward tamoxifen use for breast cancer primary prevention.

BACKGROUND: The National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 trial demonstrated that tamoxifen reduces the incidence of new breast cancers by 49% in women at increased risk for breast cancer development. Tamoxifen does have side effects, however, including marginally increased risks of endometrial cancer and thromboembolic events. In this study, women at increased risk for breast cancer development were offered tamoxifen. Their knowledge of tamoxifen as a chemopreventive agent was assessed, and factors influencing their acceptance of tamoxifen and willingness to take it were determined. METHODS: Forty-three patients were identified who qualified to take tamoxifen for primary prevention. Patients qualified by having at least a 1.7% 5-year risk of developing breast cancer, the criteria for entry into the NSABP P-1 trial. Patients initially completed questionnaires designed to assess their knowledge of tamoxifen and its associated risks and benefits. Patients were then provided neutral educational sessions and literature delineating the actual risks and benefits of tamoxifen. Subsequently, patients' decisions regarding taking tamoxifen were reassessed. RESULTS: Mean patient age was 52.8 years, with a range of 39 to 74 years. Ten patients (23.2%) qualified based on the presence of lobular carcinoma in situ (LCIS), seven patients (16.3%) qualified based on increased risk secondary to age >60 years, and 26 patients (60.5%) age range 35 to 59 qualified based on risk profiles demonstrating significantly increased risk. Of the total 43 patients, two (4.7%) elected to start taking tamoxifen. Fifteen patients (34.8%) declined immediately, and 26 patients (60.5%) were undecided initially but ultimately declined. Educational sessions did not influence patients' decisions. Fear of side effects, including endometrial cancer, thromboembolic events, and menopausal symptoms, was the most commonly cited reason for declining to take tamoxifen. CONCLUSIONS: In this study, the vast majority of patients at increased risk for breast cancer perceived that the risks of taking tamoxifen outweighed the benefits and declined to take it.

What every nurse needs to know about nocturnal sleep-related eating disorder.

This article provides information about a bizarre pattern of eating while asleep called nocturnal sleep-related eating disorder. People with this disorder, which has begun to be studied only recently, demonstrate features of both a sleep disorder and an eating disorder. Many clients are reluctant to initiate discussions regarding this condition because of feelings of powerlessness and shame. Other clients do not discuss their symptoms because nurses and other clinicians fail to gather accurate assessment data due to lack of knowledge within the professional community regarding the disorder. This review includes the historical background, definition of terms, and clinical manifestations of nocturnal sleep-related eating. In addition, emphasis on assessment and clinical management are included. Safety issues, the need to educate health care providers, and the role of the nurse in advocating for appropriate diagnosis, treatment, and referral are addressed.

The role of calcium in ABA-induced gene expression and stomatal movements.

There is much interest in the transduction pathways by which abscisic acid (ABA) regulates stomatal movements (ABA-turgor signalling) and by which this phytohormone regulates the pattern of gene expression in plant cells (ABA-nuclear signalling). A number of second messengers have been identified in both the ABA-turgor and ABA-nuclear signalling pathways. A major challenge is to understand the architecture of ABA-signalling pathways and to determine how the ABA signal is coupled to the appropriate response. We have investigated whether separate Ca2+-dependent and -independent ABA-signalling pathways are present in guard cells. Our data suggest that increases in [Ca2+]i are a common component of the guard cell ABA-turgor and ABA-nuclear signalling pathways. The effects of Ca2+ antagonists on ABA-induced stomatal closure and the ABA-responsive CDeT6-19 gene promoter suggest that Ca2+ is involved in both ABA-turgor signalling and ABA-nuclear signalling in guard cells. However, the sensitivity of these pathways to alterations in the external calcium concentration differ, suggesting that the ABA-nuclear and ABA-turgor signalling pathways are not completely convergent. Our data suggest that whilst Ca2+-independent signalling elements are present in the guard cell, they do not form a completely separate Ca2+-independent ABA-signalling pathway.