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Highlights: [•] The nervous system differentially activates regions of trunk muscles for posture. [•] Discrete activity of trunk muscles is likely to be based on mechanical advantage. [•] Discrete activity implies discrete force generation without lateral transmission. [ABSTRACT FROM AUTHOR]

The article focuses on efficient space dedication to bus rapid transit (BRT) and light rail systems. The authors propose efficient geometric configurations for a two-dedicated-lane BRT or light rail system that requires a minimal quantity of right-of-way along a busy commute arterial. The authors stress that the proposed configurations necessitate the conversion of only two lanes from general use.

Spitz nevi are melanocytic proliferations that are characterized by spindled and/or epithelioid nevomelanocytes. First interpreted as juvenile melanoma, these lesions were later characterized as benign and were observed to affect all age groups. Today, contrasting opinions persist regarding the fundamental benignancy versus malignancy within the spectrum of Spitz tumors. Beyond clinical outcome, this controversy has also been fueled by complex and sometimes convoluted classification schemes based on pathologic characteristics. More recently, immunophenotypic and molecular analyses have begun to clarify the etiologic nature of these tumors. Recent evidence suggests that histopathologic features that suggest more aggressiveness in Spitz tumors relate to mitoses and inflammation. [ABSTRACT FROM AUTHOR]

For dermatologists, evidence-based management guidelines for Spitz tumors have not been established. Despite the lack of a standardized approach, most dermatologists recommend the excision of Spitz tumors occurring in adults and adopt more conservative measures towards pediatric cases. The histopathologic attributes and the clinical scenario are factored into management in each case. While the metastatic behavior of certain Spitz tumors is well known, the malignant potential of these lesions remains unclear because they only rarely result in negative outcomes. The risks and benefits of adjunctive measures, such as sentinel lymph node biopsy and interferon use, remain untested and are subjects of ongoing controversy. (In part II of this continuing medical education article, we will continue to use the terminology defined in part I for purposes of continuity. "Spitz tumor" is used as the umbrella term for the entire category of lesions, "common Spitz nevi" refers to only the most typical lesions seen in pediatric cases, and "atypical Spitz tumors" encompass the "all other" category, which continues to cause debate.). [ABSTRACT FROM AUTHOR]

The incidence of primary cutaneous melanoma has been increasing dramatically for several decades. Melanoma accounts for the majority of skin cancer-related deaths, but treatment is nearly always curative with early detection of disease. In this update of the guidelines of care, we will discuss the treatment of patients with primary cutaneous melanoma. We will discuss biopsy techniques of a lesion clinically suspicious for melanoma and offer recommendations for the histopathologic interpretation of cutaneous melanoma. We will offer recommendations for the use of laboratory and imaging tests in the initial workup of patients with newly diagnosed melanoma and for follow-up of asymptomatic patients. With regard to treatment of primary cutaneous melanoma, we will provide recommendations for surgical margins and briefly discuss nonsurgical treatments. Finally, we will discuss the value and limitations of sentinel lymph node biopsy and offer recommendations for its use in patients with primary cutaneous melanoma. [ABSTRACT FROM AUTHOR]

Abstract: Acute low back pain (LBP) is associated with differential changes in motor coordination of deep and superficial trunk muscles. Whether this is related to differential changes in excitability of descending corticomotor inputs remains unclear and was investigated in nine healthy individuals. Fine-wire i.m. electrodes were inserted bilaterally into deep (transversus abdominis (TrA)) and superficial abdominal muscles (obliquus externus abdominis (OE)), and surface electrodes were placed bilaterally over obliquus internus abdominis (OI), rectus abdominis (RA) and lumbar erector spinae (LES) muscles. Corticomotor excitability was assessed as amplitude of motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) at a range of stimulator intensities, at rest and during voluntary abdominal contractions. Pain was induced by injection of hypertonic saline into interspinous ligaments of the lumbar spine. Corticomotor excitability was examined before, during and after the induction of LBP. During pain, amplitude of TrA MEPs to contralateral cortical stimulation was reduced, whereas amplitudes of OE and LES MEPs contralateral and ipsilateral to the stimulated cortex were increased. The findings highlight differential changes in excitability of corticomotor inputs to trunk muscles during acute LBP. Further work is required to reveal whether such changes involve spinal and/or supraspinal centres and their consequence for spine control. [Copyright &y& Elsevier]

Abstract: Fibroproliferative scars in humans often demonstrate familial inheritance patterns, and genetics may contribute to healing and scarring. Genetic factors may also influence the scarring phenotype in a porcine model. Healing of full thickness excisional skin wounds in Yorkshire pigs closely resembles normal healing in humans, while identical wounds in red Duroc pigs form hypercontracted, hyperpigmented scars. The present study has evaluated the healing process in the first generation cross (F1) of red Duroc and Yorkshire pigs. Gross and histologic analysis revealed that the F1 animals exhibit an intermediate healing phenotype, with some features of each parent breed. F1 full thickness wounds were significantly hypercontracted and fibrotic, but apigmented. Analysis of mRNA expression patterns for a panel of relevant molecules (N =32) in the F1 animals revealed some similarities to each parent breed, as well as unique patterns for other molecules. Furthermore, a depth dependency to the healing response was observed at the gross, histologic, and molecular levels, with deep dermal wounds healing similar to Yorkshire wounds. These findings suggest that the genetic contribution to scar phenotype in this animal model is complex. However, the results indicate that further understanding in this model may provide insights into risk factors for hypertrophic scarring in human burn patients. [Copyright &y& Elsevier]

The problem of finding an x∈Rn such that Ax⩽b and x⩾0 arises in numerous contexts. We propose a new optimization method for solving this feasibility problem. After converting Ax⩽b into a system of equations by introducing a slack variable for each of the linear inequalities, the method imposes an entropy function over both the original and the slack variables as the objective function. The resulting entropy optimization problem is convex and has an unconstrained convex dual. If the system is consistent and has an interior solution, then a closed-form formula converts the dual optimal solution to the primal optimal solution, which is a feasible solution for the original system of linear inequalities. An algorithm based on the Newton method is proposed for solving the unconstrained dual problem. The proposed algorithm enjoys the global convergence property with a quadratic rate of local convergence. However, if the system is inconsistent, the unconstrained dual is shown to be unbounded. Moreover, the same algorithm can detect possible inconsistency of the system. Our numerical examples reveal the insensitivity of the number of iterations to both the size of the problem and the distance between the initial solution and the feasible region. The performance of the proposed algorithm is compared to that of the surrogate constraint algorithm recently developed by Yang and Murty. Our comparison indicates that the proposed method is particularly suitable when the number of constraints is larger than that of the variables and the initial solution is not close to the feasible region. [Copyright &y& Elsevier]

CDKN2A is the major melanoma susceptibility gene so far identified, but only 40% of three or more case families have identified mutations. A comparison of mutation detection rates was carried out by 'blind' exchange of samples across GenoMEL, the Melanoma Genetics Consortium, to establish the false negative detection rates. Denaturing high performance liquid chromatography (DHPLC) screening results from 451 samples were compared to screening data from nine research groups in which the initial mutation screen had been done predominantly by sequencing. Three samples with mutations identified at the local centres were not detected by the DHPLC screen. No additional mutations were detected by DHPLC. Mutation detection across groups within GenoMEL is carried out to a consistently high standard. The relatively low rate of CDKN2A mutation detection is not due to failure to detect mutations and implies the existence of other high penetrance melanoma susceptibility genes. [ABSTRACT FROM AUTHOR]

Aims of the study. – Despite the evidence of greater fatigability of the superficial cervical flexor muscles in neck pain patients, the relationship between duration of neck pain and muscle fatigue has not been investigated. This study examined the relationship between myoelectric manifestations of sternocleidomastoid (SCM) and anterior scalene (AS) muscle fatigue and duration of neck pain in a group of patients with chronic neck pain.Materials and methods. – Twenty chronic neck pain patients with a history of pain ranging between 1 and 25 years (mean 6.15, S.D. 5.48 years) participated in this study. Myoelectric signals were recorded from the SCM and AS muscles from the side of greatest pain as patients performed sustained sub-maximal isometric cervical flexion contractions at 25% and 50% of the maximum voluntary contraction (MVC). The initial value and slope of the mean frequency (MNF), average rectified value (ARV) and conduction velocity (CV) of the EMG signals were calculated. Correlation analysis was applied to determine whether a relationship existed between the duration of neck pain and estimates of EMG variables.Results and conclusions. – No significant correlation was found between duration of pain and estimates of the MNF, ARV and CV for either SCM or AS contracting at 25% and 50% MVC. The length of history of neck pain does not appear to correlate with the extent of SCM and AS muscle fatigability in patients with chronic neck pain. This finding may be due to an increase of muscle fatigability occurring within the first few years of neck pain, which is not followed by signs of increased fatigue after this time. This was supported by the finding of significant correlations between duration of pain and AS fatigability on a subgroup of patients with pain duration less than 5 years. Future studies are warranted to examine how early signs of cervical muscle fatigability are evident after the onset of neck pain as this will have implications for rehabilitation. [Copyright &y& Elsevier]