Citations

Evaluation of tissue engineering constructs is performed by a series of different tests. In many cases it is important to match the mechanical properties of these constructs to those of native tissues. However, many mechanical testing methods are destructive in nature which increases cost for evaluation because of the need for additional samples reserved for these assessments. A wave propagation method is proposed for characterizing the shear elasticity of thin layers bounded by a rigid substrate and fluid-loading, similar to the configuration for many tissue engineering applications. An analytic wave propagation model was derived for this configuration and compared against finite element model simulations and numerical solutions from the software package Disperse. The results from the different models found very good agreement. Experiments were performed in tissue-mimicking gelatin phantoms with thicknesses of 1 and 4 mm and found that the wave propagation method could resolve the shear modulus with very good accuracy, no more than 4.10% error. This method could be used in tissue engineering applications to monitor tissue engineering construct maturation with a nondestructive wave propagation method to evaluate the shear modulus of a material.

AbstractBackgroundThe aim is to study the safety of Angioembolization on long-term sexual function and quality of life.MethodsIRB approval was gained to review the prospectively collected trauma database as well as prospective questionnaires of patients at least 1 year out from pelvic fractures that occurred between 1996 and 2009. Surveys included the SF36v2, Female Sexual Function Index and the International Index of Erectile Function. Values for each domain were compared between patients treated with AE and 2:1 case-matched control patients as well as between the national norms. Values are presented as percentages or means with 95 % CI. P < 0.05 was considered statistically significant.ResultsThirty Seven cases and 74 matched controls were identified. 42 patients completed the survey. There were 13 cases (12 males), and 29 controls (22 males). There was a higher ISS (Injury Severity Score) (32 vs 27; p = 0.048) in the cases, but no difference in pelvic AIS (Abbreviated Injury Severity Score) (3 vs 3). Both groups scored similarly in the SF36 in all domains, but the entire cohort scored lower than the national norms in the physical functioning (41.9 (37.8–46.0) vs50), role physical (40.9 (36.2–45.7) vs50), body pain 43.8 (40.7–46.9) vs50), role emotional 46.3 (42.8–49.8) vs50), and physical composite score (42.1 (38.0–46.3) vs50). All domains of the sexual function in both questionnaires showed significant impairment in our cohort compared with norms. Male cases had similar scores to the controls.ConclusionPelvic fractures portend a worse long-term QOL and sexual function than the general population. AE, however, does not have an additive affect to these indices.

SummaryAimsFibrillar aggregates of β‐amyloid protein (Aβ) are the main constituent of senile plaques and considered to be one of the causative events in the pathogenesis of Alzheimer's disease (AD). Compounds that could inhibit Aβ fibrils formation, disaggregate preformed Aβ fibrils as well as reduce their associated neurotoxicity might have therapeutic values for treating AD. In this study, the inhibitory effects of bis (heptyl)‐cognitin (B7C), a multifunctional dimer derived from tacrine, on aggregation and neurotoxicity of Aβ1‐40 were evaluated both in vitro and in vivo.MethodsThioflavin T fluorescence assay was carried out to evaluate Aβ aggregation, MTT and Hoechst‐staining assays were performed to investigate Aβ‐associated neurotoxicity. Fluorescent probe DCFH‐DA was used to estimate the accumulation of intracellular reactive oxygen stress (ROS). Morris water maze was applied to determine learning and memory deficits induced by intracerebroventricular infusion of Aβ in rats.ResultsB7C (0.1–10 μM), but not tacrine, effectively inhibited Aβ fibrils formation and disaggregated preformed Aβ fibrils following co‐incubation of B7C and Aβ monomers or preformed fibrils, respectively. In addition, B7C markedly reduced Aβ fibrils‐associated neurotoxicity in SH‐SY5Y cell line, as evidenced by the increase in cell survival, the decrease in Hoechst‐stained nuclei and in intracellular ROS. Most encouragingly, B7C (0.1 and 0.2 mg/kg), 10 times more potently than tacrine (1 and 2 mg/kg), inhibited memory impairments after intracerebroventricular infusion of Aβ in rats, as evidenced by the decrease in escape latency and the increase in the spatial bias in Morris water maze test along with upregulation of choline acetyltransferase activity and downregulation of acetylcholinesterase activity.ConclusionThese findings provide not only novel molecular insight into the potential application of B7C in treating AD, but also an effective approach for screening anti‐AD agents.

Workload experienced by health care workers continues to be a challenge to define and quantify. The purpose of the current study is to present descriptive data on the application of sociometers in an emergency care environment during simulated hand-off scenarios and discuss their potential and limitations for quantifying individual’s workload in health care settings. Sociometer devices, worn by nine actors, collected body movement, interactions, and speech data during four simulated hand-off scenarios in the emergency department wards. Results found that sociometers distinguished body movement differences between sitting, standing, lying, and walking individuals. Interactions quantified by the devices were limited by obstructions, distance, and angles between the sociometer devices. The data collected by these devices show promise in providing human factors researchers a tool for quantifying the dynamic exposures experienced by health care workers over time.

In complex health care situations, teamwork becomes immensely integral to favorable patient outcomes. This study examines an unusual prolonged resuscitation case to understand elements that contributed to the successful outcome of this patient. Through use of the Shared Mental Model Framework (SMMF), we highlighted the importance of multidisciplinary teamwork during resuscitation efforts by analyzing team members’ perceptions through surveys. An 11-item open-ended questionnaire was administered to clinicians (N=9) involved in the resuscitation effort. A case analysis technique was used to identify four key themes that contributed to the success of this resuscitation effort: (1) clear goals are essential to the team’s functioning; (2) strong and effective communication solidified longitudinally among team members; (3) provider’s expertise was paramount to the case’s success; and (4) resources readily available helped manage the team’s cohesiveness. Identifying key teamwork elements in successful resuscitation efforts further informs the valuable need for team cohesiveness in health care.

Surgical trainees undergo demanding training to achieve high surgical task proficiency. Abounding clinical and educational responsibilities mandate efficient and effective training. This research measured resident workload during laparoscopic skills training to identify excessive workload and how workload impacted task performance. Twenty-eight surgical trainees performed a standardized surgical training task and completed a workload questionnaire while observers measured physiological stress, posture risk assessment, and task performance. Participants self-reported mental demands, physical demands, temporal demands, performance, effort, and frustration. Effort (12±4) and frustration (12±5) were the highest subscales while physical demand (8±4) was the lowest. All participants were observed performing the task in at-risk postures, with 21% exhibiting risk levels requiring immediate intervention. Physical demand was associated with posture risk assessment scores (p<0.05). Mental demand was positively (R 2 =0.20, p<0.05) and frustration was negatively (R 2 =0.18, p<0.05) associated with skin conductance range. A point increase in physical demand was associated with a six second increase in performance time (β=6.0, p=0.01). These results support the fact that human factors and ergonomic tools can be used to relate surgical skills performance with workload, stress, and posture risks.

Laparoendoscopic single site surgery (LESS) can provide potential patient benefits beyond conventional laparoscopy (CL). However, LESS further exacerbates current ergonomic disadvantages of CL. LESS practices to compensate for the constraints include intracorporeal crossing of instruments (UL) for improved manipulation of instrumentation and extracorporeal crossing of hands (PL) for illusion mitigation. Preliminary results from this study involving 12 medical students (7 males) performing a simulated surgical task found statistical difference between CL, PL, and UL for physical demand (P<0.001), task complexity (P=0.002) and performance times (P<0.001) with no difference for mental demand (P=0.106). These initial findings show that the PL technique cannot currently compensate for the limitations of LESS to make UL more similar to CL. Further research is needed to determine if PL or another LESS compensatory practice can allow surgeons to more effectively perform procedures with a single port and therefore ensure patients reap its benefits.

Prior to the initiation of menopausal hormone treatment (MHT), genetic variations in the innate immunity pathway were found to be associated with carotid artery intima-medial thickness (CIMT) and coronary arterial calcification (CAC) in women ( n = 606) enrolled in the Kronos Early Estrogen Prevention Study (KEEPS). Whether MHT might affect these associations is unknown. The association of treatment outcomes with variation in the same 764 candidate genes was evaluated in the same KEEPS participants 4 yr after randomization to either oral conjugated equine estrogens (0.45 mg/day), transdermal 17β-estradiol (50 μg/day), each with progesterone (200 mg/day) for 12 days each month, or placebo pills and patch. Twenty SNPs within the innate immunity pathway most related with CIMT after 4 yr were not among those associated with CIMT prior to MHT. In 403 women who completed the study in their assigned treatment group, single nucleotide polymorphisms (SNPs) within the innate immunity pathway were found to alter the treatment effect on 4 yr change in CIMT (i.e., significant interaction between treatment and genetic variation in the innate immunity pathway; P < 0.001). No SNPs by treatment effects were observed with changes of CAC >5 Agatston units after 4 yr. Results of this study suggest that hormonal status may interact with genetic variants to influence cardiovascular phenotypes, specifically, the pharmacogenomic effects within the innate immunity pathway for CIMT.