The influence of ligament biomechanics on proximal junctional kyphosis and failure in patients with adult spinal deformity.

Purpose: It is unknown whether the biomechanics of the posterior ligamentous complex (PLC) are impaired in individuals undergoing surgery for adult spinal deformity (ASD). Characterizing these properties may improve our understanding of proximal junctional kyphosis (PJK; defined as proximal junctional angle [PJA] of >10 deg from UIV-1 to UIV + 2), as well as proximal junctional failure (PJF; symptomatic PJK requiring revision). The purpose of this prospective observational study is to compare biomechanical properties of the PLC in individuals with ASD who do, and do not develop PJK or PJF within 1 year of spinal fusion surgery. Methods: Intraoperative biopsies of PLC were obtained from 32 consecutive patients undergoing spinal fusions for ASD (>4 levels). Ligament peak force, tensile stress, tensile strain, and elastic modulus (EM) were measured with a materials testing system. Biomechanical properties and tissue dimensions were correlated with age, gender, BMI, vitamin D level, osteoporosis, sagittal alignment, PJA and change in PJA preoperatively, within 3 months, and at 1 year postoperatively. Results: Longer ligaments were associated with greater PJA change at 3 months (p = 0.04), and thinner ligaments were associated with greater PJA change at 1 year (r = 0.57, p = 0.01). Greater EM was associated with greater PJA at both 3 months and 1 year (p = 0.03). Five participants had a change in PJA of >10 1 year postoperatively, and three participants demonstrated PJF. EM was significantly higher in individuals who required revision surgery (p = 0.003), and ligament length was greater (p = 0.03). Preoperative sagittal alignment was not related to incidence of revision surgery (p > 0.10). Conclusions: The biomechanical properties of the PLC may be associated with higher risk for proximal failure. Ligaments that are longer, thinner, and less elastic are associated with higher postoperative PJA. Furthermore stiffer EM of the ligament is associated with the need for revision surgery.

Paraspinal muscle gene expression across different aetiologies in individuals undergoing surgery for lumbar spine pathology.

PURPOSE: The purpose of this study was to understand potential baseline transcriptional expression differences in paraspinal skeletal muscle from patients with different underlying lumbar pathologies by comparing multifidus gene expression profiles across individuals with either disc herniation, facet arthropathy, or degenerative spondylolisthesis. METHODS: Multifidus biopsies were obtained from patients (n = 44) undergoing lumbar surgery for either disc herniation, facet arthropathy, or degenerative spondylolisthesis. Diagnostic categories were based on magnetic resonance images, radiology reports, and intraoperative reports. Gene expression for 42 genes was analysed using qPCR. A one-way analysis of variance was performed for each gene to determine differences in expression across diagnostic groups. Corrections for multiple comparisons across genes (Benjamini-Hochberg) and for between-group post hoc comparisons (Sidak) were applied. RESULTS: Adipogenic gene (ADIPOQ) expression was higher in the disc herniation group when compared to the facet arthropathy group (p = 0.032). Adipogenic gene (PPARD) expression was higher in the degenerative spondylolisthesis group when compared to the disc herniation group (p = 0.013), although absolute gene expression levels for all groups was low. Fibrogenic gene (COL3A1) had significantly higher expression in the disc herniation group and facet arthropathy group when compared to the degenerative spondylolisthesis group (p < 0.001 and p = 0.038, respectively). When adjusted for multiple comparisons, only COL3A1 remained significant (p = 0.012). CONCLUSION: Individuals with disc herniation and facet arthropathy demonstrate higher COL3A1 gene expression compared to those with degenerative spondylolisthesis. Future research is required to further understand the biological relevance of these transcriptional differences.

Heating Up to Keep Cool: Benefits and Persistence of a Practical Heat Acclimation Protocol in Elite Female Olympic Team-Sport Athletes.

PURPOSE: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program. METHODS: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay). RESULTS: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41). CONCLUSIONS: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.

Paraspinal Muscle Health is Related to Fibrogenic, Adipogenic, and Myogenic Gene Expression in Patients with Lumbar Spine Pathology.

BACKGROUND: Lumbar spine pathology is a common feature of lower back and/or lower extremity pain and is associated with observable degenerative changes in the lumbar paraspinal muscles that are associated with poor clinical prognosis. Despite the commonly observed phenotype of muscle degeneration in this patient population, its underlying molecular mechanisms are not well understood. The aim of this study was to investigate the relationships between groups of genes within the atrophic, myogenic, fibrogenic, adipogenic, and inflammatory pathways and multifidus muscle health in individuals undergoing surgery for lumbar spine pathology. METHODS: Multifidus muscle biopsies were obtained from patients (n = 59) undergoing surgery for lumbar spine pathology to analyze 42 genes from relevant adipogenic/metabolic, atrophic, fibrogenic, inflammatory, and myogenic gene pathways using quantitative polymerase chain reaction. Multifidus muscle morphology was examined preoperatively in these patients at the level and side of biopsy using T2-weighted magnetic resonance imaging to determine whole muscle compartment area, lean muscle area, fat cross-sectional areas, and proportion of fat within the muscle compartment. These measures were used to investigate the relationships between gene expression patterns and muscle size and quality. RESULTS: Relationships between gene expression and imaging revealed significant associations between decreased expression of adipogenic/metabolic gene (PPARD), increased expression of fibrogenic gene (COL3A1), and lower fat fraction on MRI (r = -0.346, p = 0.018, and r = 0.386, p = 0.047 respectively). Decreased expression of myogenic gene (mTOR) was related to greater lean muscle cross-sectional area (r = 0.388, p = 0.045). CONCLUSION: Fibrogenic and adipogenic/metabolic genes were related to pre-operative muscle quality, and myogenic genes were related to pre-operative muscle size. These findings provide insight into molecular pathways associated with muscle health in the presence of lumbar spine pathology, establishing a foundation for future research that addresses how these changes impact outcomes in this patient population.

Sex Differences in Injection Drug Risk Behaviors Among Hospitalized Persons.

OBJECTIVES: As opioid use increases, it remains important to assess factors that contribute to injection drug risk behaviors, as sharing needles and other drug use equipment contributes to the spread of human immunodeficiency virus and hepatitis C virus. Such risks may differ by sex and injecting with others. The current study examined factors that contribute to increased injection drug risk separately for men and women. METHODS: People who inject drugs were recruited at an academic safety-net hospital that reported recent injection drug use. Two main injection outcomes were assessed: (1) human immunodeficiency virus drug risk behaviors as assessed by the Risk Assessment Battery and (2) the number of times participants injected drugs with a needle used by someone else. For each outcome, different models for women and men were conducted to detect differences by sex. RESULTS: Both men and women were more likely to inject with a needle used by someone else if they used drugs within a sexual relationship (incidence rate ratio (IRR) = 14.61, P < 0.01; IRR = 7.17, P < 0.05). Being employed was associated with lower risk assessment battery scores among men, and lower mean rates of using a needle used by someone else among women (IRR = 0.22, P < 0.05). Women with post-traumatic stress disorder (PTSD) and men with higher depression scores had higher rates of injecting with a needle used by someone else. CONCLUSIONS: People who inject drugs who are in intimate relationships report higher injection drug risk behaviors. We found benefits to employment among both men and women. Identifying factors associated with increased injection risk behaviors can be useful for creating interventions tailored by sex.

Comparison of anesthetic management and outcomes of robot-assisted versus open radical cystectomy.

Robot-assisted cystectomy surgery may be advantageous for patients. The purpose of this study was to compare anesthetic management and outcomes in patients undergoing robot-assisted versus open radical cystectomy. In a retrospective review of 256 cystectomy procedures, procedure duration, blood loss, respiratory parameters, recovery room opiate consumption, pain scores and antiemetic use in the recovery room, and hospital length of stay were compared. After exclusions, 96 robot-assisted and 102 open procedures were analyzed. Anesthesia and surgery duration were significantly longer in the robot-assisted group, while the length of hospital stay was significantly shorter in the robot-assisted group: 7.1 ± 5.8 versus 9.8 ± 5.03 days, p = 0.0005. Estimated blood loss was 601.8 ± 491.4 ml in the open group versus 257.7 ± 164.3 ml in the robot-assisted group, p < 0.0001. Recovery room opiate consumption was significantly less in the robot-assisted group: 9.5 ± 8.9 versus 12.6 ± 9.9 mg (morphine equivalents), p = 0.02. The highest recorded respiratory rate was significantly higher in the robot-assisted group, as was the highest recorded peak airway pressure. Among patients with arterial blood gas data, the highest arterial partial pressure of CO2 was significantly greater in the robot-assisted group than in the open surgery group: 42.6 ± 5.6 versus 37.4 ± 4.8 mmHg CO2, p = 0.0001. Surgeons and anesthesia providers can expect robot-assisted radical cystectomy surgery to last longer than traditional open surgery, but to be associated with less pain and blood loss. Positioning and abdominal insufflation for robot-assisted surgery may contribute to ventilation challenges.

A brief description of the biomechanics and physiology of a strongman event: the tire flip.

The purpose of this study was to (a) characterize the temporal aspects of a popular strongman event, the tire flip; (b) gain some insight into the temporal factors that could distinguish the slowest and fastest flips; and (c) obtain preliminary data on the physiological stress of this exercise. Five resistance-trained subjects with experience in performing the tire flip gave informed consent to participate in this study. Each subject performed 2 sets of 6 tire flips with a 232-kg tire with 3 minutes of rest between sets. Temporal variables were obtained from video cameras positioned 10 m from the tire, perpendicular to the intended direction of the tire flip. Using the "stopwatch" function in Silicon Coach, the duration of each tire flip and that of the first pull, second pull, transition, and push phases were recorded. Physiological stress was estimated via heart rate and finger-prick blood lactate response. Independent T-tests revealed that the 2 faster subjects (0.38 +/- 0.17 s) had significantly (p < 0.001) shorter second pull durations than the 3 slower subjects (1.49 +/- 0.92 s). Paired T-tests revealed that the duration of the second pull for each subject's fastest 3 trials (0.55 +/- 0.35 s) were significantly (p = 0.007) less than their 3 slowest trials (1.69 +/- 1.35 s). Relatively high heart rate (179 +/- 8 bpm) and blood lactate (10.4 +/- 1.3 mmol/L(-1)) values were found at the conclusion of the second set. Overall, the results of this study suggest that the duration of the second pull is a key determinant of tire flip performance and that this exercise provides relatively high degrees of physiological stress.

Assessing the severity of hazardous drinking and related consequences among incarcerated women.

BACKGROUND: Recent epidemiological efforts have demonstrated the utility of measuring individual differences in the severity of alcohol use along a single severity continuum marked by alcohol-related problems, symptoms of alcohol dependence, and the social consequences of drinking. Translation of this utility to specialized clinical populations is not assured. The expected inter-relationships among problems, symptoms and consequences, and enhanced sensitivity of combined assessments require confirmation in applied clinical settings. METHOD: Subjects were 245 incarcerated women who met Alcohol Use Disorders Identification Test criteria for hazardous use of alcohol. Participants were recruited from a statewide adult correctional facility for an ongoing clinical trial testing the effectiveness of brief motivational interviewing on alcohol use and HIV risk behaviors. Participants ranged in age from 18 to 56 (M = 34.1, SD = 8.9), 71.4% were Caucasian, and 65.7% reported <12 years of education. RESULTS: Analyses suggested that the 6 problems of alcohol abuse, 7 symptoms for alcohol dependence, and 14 alcohol-related social consequences loaded to a single factor (0.38 to 0.85) that formed a continuum of alcohol severity. Contrary to epidemiological studies, physical fights and being arrested were the most prevalent consequences and were associated with lower alcohol severity in this population. Three of the five items that discriminated best between higher and lower alcohol severity were related to familial and relationship consequences. CONCLUSIONS: Consistent with epidemiological studies, alcohol severity can be measured among incarcerated hazardously drinking women on a single continuum that includes alcohol problems, symptoms, and social consequences. Replication of the expected alignment of problems and symptoms supports the construct validity of the continuum and further challenges the proposed hierarchical structure of abuse/dependence distinction. Large differences in rates of specific consequences and observed effectiveness of tailored social consequence items suggest the benefits of cross-sample validation to improve evaluation of clinical outcomes.

A new asset for pathogen informatics--the Enteropathogen Resource Integration Center (ERIC), an NIAID Bioinformatics Resource Center for Biodefense and Emerging/Re-emerging Infectious Disease.

ERIC (Enteropathogen Resource Information Center) is one of the National Institute of Allergy and Infectious Diseases (NIAID) Bioinformatics Resource Centers for Biodefense and Emerging/Re-emerging Infectious Disease. ERIC serves as a comprehensive information resource for five related pathogens: Yersinia enterocolitica, Yersinia pestis, diarrheagenic E. coli, Shigella spp., and Salmonella spp. ERIC integrates genomics, proteomics, biochemical and microbiological information to facilitate the interpretation and understanding of ERIC pathogens and select related non-pathogens for the advancement of diagnostics, therapeutics, and vaccines. ERIC (www.ericbrc.org) is evolving to provide state-of-the-art analysis tools and data types, such as genome sequencing, comparative genomics, genome polymorphisms, gene expression, proteomics, and pathways as well as expertly curated community genome annotation. Genome sequence and genome annotation data and a variety of analysis and tools for eight strains of Yersinia enterocolitica and Yersinia pestis pathogens (Yersinia pestis biovars Mediaevalis KIM, Mediaevalis 91001, Orientalis CO92, Orientalis IP275, Antiqua Angola, Antiqua Antiqua, Antiqua Nepal516, and Yersinia enterocolitica 8081) and two strains of Yersinia pseudotuberculosis (Yersinia pseudotuberculosis IP32953 and IP31758) are currently available through the ERIC portal. ERIC seeks to maintain a strong collaboration with the scientific community so that we can continue to identify and incorporate the latest research data, tools, and training to best meet the current and future needs of the enteropathogen research community. All tools and data developed under this NIAID contract will be freely available. Please contact info@ericbrc.org for more information.

Adverse short-term effects of attention-control treatment on hypnotizability: a challenge in designing controlled hypnosis trials.

Characteristics of patients in test and attention-control groups should be comparable and be unaffected by the intervention to be tested in clinical trials. The authors assessed whether this is the case for measures of hypnotizability in the postoperative period. One hundred and forty-six patients undergoing percutaneous peripheral vascular or renal interventions were randomized into 2 groups. One group received structured empathic attention during their procedures; the other was guided to self-hypnotic relaxation. Hypnotizability was assessed postoperatively by the Hypnotic Induction Profile. The eye-roll scores, which measure the biological hypnotic potential, were not significantly different, but the average induction scores, which measure the expression of the hypnotic performance, were significantly lower in the attention group than the hypnosis group (4.9 vs. 5.9). The authors conclude that patients who were aided by an external focus intraoperatively are postoperatively less able or willing to follow suggestions measuring hypnotizability than patients who had guidance to self-hypnotic relaxation.

Shaping the experience of behavior: construct of an electronic teaching module in nonpharmacologic analgesia and anxiolysis.

RATIONALE AND OBJECTIVES: The authors' purpose was to develop an electronic teaching module in nonpharmacologic analgesia and anxiolysis for use in the radiology department. MATERIALS AND METHODS: The teaching document was derived from previous training courses validated by patient outcome. Skills in structured empathic attention and guidance of self-hypnotic relaxation were tested in a previous prospective, randomized study with 241 patients and shown to affect positively patients' perception of pain and anxiety. Patients undergoing hypnosis had the greatest relief and most hemodynamic stability. The skills applied also saved, on average, 17 minutes of procedure time and approximately $340 in sedation cost per case. With these validated behavioral skills, an electronic teaching module was constructed. RESULTS: The mode of teaching reflected the content of teaching, which was achieved through a multimedia format containing text, audio, video, pictures, and animation. Advanced navigation tools put the students in control of their learning experience. Inclusion of experiential components, congruity of language with Ericksonian syntax, and provision of an electronic journal catered to the development of greater biobehavioral awareness. CONCLUSION: Electronic teaching modules for biobehavioral skill training are feasible and promise to reduce the time need for life interactions with instructors.