Choice of autogenous conduit for lower extremity vein graft revisions

AbstractBackground: Surgical revision to repair stenosis is necessary in about 20% of lower extremity vein grafts (LEVGs). Alternate conduit, especially arm vein, is often necessary to achieve a policy of all-autogenous revisions. Although basilic vein harvest necessitates deep exposure in proximity to major nerves, it typically uses a large vein unaffected by prior intravenous lines and as such appears ideally suited for revisions in which a segmental interposition conduit is needed for revision within the graft or for extension to a more proximal inflow or distal outflow site. In this report, we describe our experience with the use of the basilic vein for LEVG revisions compared with other sources of autogenous conduit. Methods: All patients who underwent LEVG were placed in a duplex scan surveillance program. LEVGs that developed a focal area of increased velocity or uniformly low velocities throughout the graft with appropriate lesions confirmed with angiography were candidates for revision. All patients who underwent graft revision with basilic vein segments from January 1, 1990, to September 1, 2001, were identified, and their courses were reviewed for subsequent adverse events (further revision or occlusion) and complications of harvest. These revisions were compared with revisions in which cephalic and saphenous vein were used. Results: One hundred thirty basilic veins were used to revise 122 LEVGs. The mean follow-up period after revision was 28 ± 27 months. Ninety-three grafts (71%) remained patent with no further revision, and 37 grafts (29%) either needed additional revisions (22 grafts) or were occluded (15 grafts). Only four of these adverse events (11%) were directly attributed to the basilic vein segment. Ten of 43 grafts revised with cephalic vein (23%) were either revised or occluded, of which three were related to the cephalic vein segment (P = not significant, compared with basilic vein). Twenty-four of 81 grafts revised with saphenous vein (30%) were either revised or occluded, of which 11 were attributed to the saphenous vein segment (P < .01, compared with basilic vein). Two patients (1.5%) had complications from basilic vein harvest (one hematoma, one arterial injury). No neurologic injuries resulted from basilic vein harvest. Conclusion: The basilic vein is a reliable and durable conduit when used to segmentally revise LEVGs. Stenoses rarely occur within interposed basilic vein segments, and excellent freedom from subsequent revision or occlusion is possible. We conclude the basilic vein can be safely harvested with minimal complications and is ideally suited for use as a short segment interposition graft for LEVG revision. (J Vasc Surg 2002;36:238-44.

Neuromuscular training improves lower extremity biomechanics associated with knee injury during landing in 11-13 year old female netball athletes: A randomized control study

The purpose of this study was to examine the effects of a neuromuscular training (NMT) program on lower-extremity biomechanics in youth female netball athletes. The hypothesis was that significant improvements would be found in landing biomechanics of the lower-extremities, commonly associated with anterior cruciate ligament (ACL) injury, following NMT. Twenty-three athletes (age = 12.2 ± 0.9 years; height = 1.63 ± 0.08 m; mass = 51.8 ± 8.5 kg) completed two testing sessions separated by 7-weeks and were randomly assigned to either a experimental or control group. Thirteen athletes underwent 6-weeks of NMT, while the remaining 10 served as controls and continued their regular netball training. Three-dimensional lower-extremity kinematics and vertical ground reaction force (VGRF) were measured during two landing tasks, a drop vertical jump and a double leg broad jump with a single leg landing. The experimental group significantly increased bilateral knee marker distance during the bilateral landing task at maximum knee-flexion range of motion. Knee internal rotation angle during the unilateral landing task at maximum knee flexion-extension range of motion was significantly reduced (p ≤ 0.05, g \u3e 1.00). The experimental group showed large, significant decreases in peak vertical ground reaction force in both landing tasks (p ≤ 0.05, g \u3e −1.30). Control participants did not demonstrate any significant pre-to-post-test changes in response to the 6-week study period. Results of the study affirm the hypothesis that a 6-week NMT program can enhance landing biomechanics associated with ACL injury in 11–13 year old female netball athletes

The genetic basis for adaptation of model-designed syntrophic co-cultures.

Understanding the fundamental characteristics of microbial communities could have far reaching implications for human health and applied biotechnology. Despite this, much is still unknown regarding the genetic basis and evolutionary strategies underlying the formation of viable synthetic communities. By pairing auxotrophic mutants in co-culture, it has been demonstrated that viable nascent E. coli communities can be established where the mutant strains are metabolically coupled. A novel algorithm, OptAux, was constructed to design 61 unique multi-knockout E. coli auxotrophic strains that require significant metabolite uptake to grow. These predicted knockouts included a diverse set of novel non-specific auxotrophs that result from inhibition of major biosynthetic subsystems. Three OptAux predicted non-specific auxotrophic strains-with diverse metabolic deficiencies-were co-cultured with an L-histidine auxotroph and optimized via adaptive laboratory evolution (ALE). Time-course sequencing revealed the genetic changes employed by each strain to achieve higher community growth rates and provided insight into mechanisms for adapting to the syntrophic niche. A community model of metabolism and gene expression was utilized to predict the relative community composition and fundamental characteristics of the evolved communities. This work presents new insight into the genetic strategies underlying viable nascent community formation and a cutting-edge computational method to elucidate metabolic changes that empower the creation of cooperative communities

The influence of biological maturity on dynamic force–time variables and vaulting performance in young female gymnasts

Purpose: This cross-sectional study investigated dynamic force–time variables and vaulting performance in young female gymnasts of different maturity status. Methods: 120 gymnasts aged 5–14 years were sub-divided into maturity groupings using percent of predicted adult height (%PAH) attained. Participants performed three jumping protocols, the squat jump (SJ), countermovement jump (CMJ) and drop jump (DJ), before completing straight jump vaults that were recorded using two-dimensional video. Results: Jumping performance improved with biological maturity evidenced by the most mature gymnasts’ producing significantly more absolute force (P \u3c 0.05; all d \u3e 0.78), impulse (P \u3c 0.05; all d \u3e 0.75) and power (P \u3c 0.05; all d \u3e 0.91) than the least mature group, resulting in the greater jump heights (P \u3c 0.05; all d \u3e 0.70). While, no significant differences were observed in relative peak force across multiple tests, measures of relative peak power did significantly increase with maturity. Based upon regression analyses, maturation was found to influence vertical take-off velocity during vaulting, explaining 41% of the variance in each jumping protocol. Across all tests, the DJ was found to have the highest predictive ability of vaulting vertical take-off velocity, explaining 55% of the total variance. Conclusion: Biological maturation impacts jump height and underpinning mechanical variables in young female gymnasts. Vaulting vertical take-off velocity appears to be influenced by maturation and various dynamic force–time variables, particularly those during DJ, which had the highest explained total variance

An Analytic Variational Study of the Mass Spectrum in 2+1 Dimensional SU(3) Hamiltonian Lattice Gauge Theory

We calculate the masses of the lowest lying eigenstates of improved SU(2) and SU(3) lattice gauge theory in 2+1 dimensions using an analytic variational approach. The ground state is approximated by a one plaquette trial state and mass gaps are calculated in the symmetric and antisymmetric sectors by minimising over a suitable basis of rectangular states

Bayesian approach to cyclic activity of CF Oct

Bayesian statistical methods of Gregory-Loredo and the Bretthorst generalization of the Lomb-Scargle periodogram have been applied for studying activity cycles of the early K-type subgiant star CF Oct. We have used a ~45 year long dataset derived from archival photographic observations, published photoelectric photometry, Hipparcos data series and All Sky Automated Survey archive. We have confirmed the already known rotational period for the star of 20.16 d and have shown evidences that it has exhibited changes from 19.90 d to 20.45 d. This is an indication for stellar surface differential rotation.The Bayesian magnitude and time--residual analysis reveals clearly at least one long-term cycle. The cycle lenght's posterior distributions appear to be multimodal with a pronounced peak at a period of 7.1 y with FWHM of 54 d for time-residuals and at a period of 9.8 y with FWHM of 184 d for magitude data. These results are consistent with the previously postulated cycle of 9+/-3 years.Comment: The paper contains 6 figures and 3 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa