The primary objectives of this study were 1) to determine the functional relationship between microvascular blood flow (Q) and arteriolar internal diameter (D) and 2) to determine whether this relationship conformed to a theoretical optimality prediction--that blood flow is proportional to the cube of the diameter (Q = kD3). Paired blood velocity and arteriolar diameter measurements in the cremaster muscle microvasculature of eight normotensive (WKY) and eight hypertensive (SHR) rats were made under control conditions and following maximal dilation of the microvasculature with topically applied adenosine. A total of 160 paired flow-diameter measurements were made in arteriolar vessels with diameters ranging from 6 to 108 micron. Analysis of this data showed that Q and D were functionally linked by Q = kDm with k = 417 and m = 3.01 with D expressed in centimeters. Confidence intervals at the 99.9% level were 331-503 and 2.86-3.14 for k and m, respectively. A theoretical development based on the minimization of the energy cost of blood volume and arteriolar wall volume led to a theoretical estimate for the range of k to be 92-132 and a value for m to be 3. Predicted pressure gradients in single vessels of the cat mesentery and shear rates in the rat cremaster based on Q = kD3 compared well with measured data reported in the literature and that determined in the present study. On the basis of the direct and predictive evidence, it is concluded that the relationship Q = kD3 represents a general average property of the microvasculature.

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Unmanaged emotional reactions to stress not only lead to behavior problems in young people but also create physiological conditions that inhibit learning and potentially increase the risk of disease later in life. For these reasons, the integration of emotional self-management skills training programs has become an increased priority in some schools. In this study, middle school students enrolled in a course in emotional competence skills learned techniques designed to intercept stressful responses during emotionally challenging situations. Behavioral outcomes were assessed using the Achievement Inventory Measure and autonomic function was measured by heart rate variability (HRV) analysis during and after a stressful interview. Following the program, students exhibited significant improvements in areas including stress and anger management, risky behavior, work management and focus, and relationships with family, peers and teachers. These improvements were sustained over the following six months. Students using the skills taught in the course to recover from acute emotional stress were also able to positively modulate their physiological stress responses. As compared to a control group, trained students demonstrated significantly increased HRV and more rhythmic, sine wave-like heart rhythm patterns during recovery. This response pattern reflects increased parasympathetic activity, heart rhythm coherence, and entrainment of other biological oscillatory systems to the primary heart rhythm frequency. Increased physiological coherence is associated with improved cognitive performance, emotional balance, mental clarity and health outcomes. These physiological shifts could promote the sustained psychological and behavioral improvements associated with the use of emotional management skills. It is suggested that learning emotional competence skills in childhood establishes healthier physiological response patterns which can benefit learning and long-term health. Results provide support for the integration in school curricula of courses designed to teach effective self-management skills to children.

PurposePneumatic compression devices (PCDs) are used in the home setting as adjunctive treatment for lymphedema after acute treatment in a clinical setting. PCDs range in complexity from simple to technologically advanced. The objective of this prospective, randomized study was to determine whether an advanced PCD (APCD) provides better outcomes as measured by arm edema and tissue water reductions compared to a standard PCD (SPCD) in patients with arm lymphedema after breast cancer treatment.MethodsSubjects were randomized to an APCD (Flexitouch system, HCPCS E0652) or SPCD (Bio Compression 2004, HCPCS E0651) used for home treatment 1 h/day for 12 weeks. Pressure settings were 30 mmHg for the SPCD and upper extremity treatment program (UE01) with standard pressure for the APCD. Thirty-six subjects (18 per group) with unilateral upper extremity lymphedema with at least 5% arm edema volume at the time of enrollment, completed treatments over the 12-week period. Arm volumes were determined from arm girth measurements and suitable model calculations, and tissue water was determined based on measurements of the arm tissue dielectric constant (TDC).ResultsThe APCD-treated group experienced an average of 29% reduction in edema compared to a 16% increase in the SPCD group. Mean changes in TDC values were a 5.8% reduction for the APCD group and a 1.9% increase for the SPCD group.ConclusionThis study suggests that for the home maintenance phase of treatment of arm lymphedema secondary to breast cancer therapy, the adjuvant treatment with an APCD provides better outcomes than with a SPCD.