The effect of smoking on 30-day complications following primary repair of Achilles tendon ruptures.

PURPOSE: There exists a gap in the knowledge of the impact of smoking on Achilles tendon rupture repair. This study evaluates perioperative and postoperative complications associated with smoking to allow for a more informed evaluation and discussion with the patients when considering the surgical management of Achilles tendon repair in this patient population. METHODS: The National Surgical Quality Improvement Program database was queried for patients undergoing Achilles tendon rupture repair from 2006 to 2019. Two patient cohorts were defined in this retrospective study: smokers and patients who did not smoke. The various patient demographics, medical comorbidities, and postoperative outcomes were compared using bivariate and multivariate analyses between the smoking and non-smoking groups. RESULTS: Of 4209 patients who underwent Achilles tendon repair, 3662 patients (87%) did not smoke, whereas 547 patients (13%) were smokers. Patients who were smokers were more likely to be younger and have a higher body mass index. Following multivariate analyses, those who smoked had an increased risk of experiencing wound dehiscence (OR 3.57; p = 0.013) and urinary tract infections (OR 1.21; p = 0.033) compared to non-smoking patients. CONCLUSION: Despite the rate of complications being relatively low in the short-term perioperative period, individuals who smoke should be counseled on the surgical risks they may experience following Achilles tendon repair, including wound dehiscence and urinary tract infections. Discussion preoperatively between the physician and patient who smoke can include ways in which postoperative care will be done to minimize the risk of adverse events, ultimately reducing costs for both the patient and the hospital.

A genetic chronology for the Indian Subcontinent points to heavily sex-biased dispersals.

BACKGROUND: India is a patchwork of tribal and non-tribal populations that speak many different languages from various language families. Indo-European, spoken across northern and central India, and also in Pakistan and Bangladesh, has been frequently connected to the so-called "Indo-Aryan invasions" from Central Asia ~3.5 ka and the establishment of the caste system, but the extent of immigration at this time remains extremely controversial. South India, on the other hand, is dominated by Dravidian languages. India displays a high level of endogamy due to its strict social boundaries, and high genetic drift as a result of long-term isolation which, together with a very complex history, makes the genetic study of Indian populations challenging. RESULTS: We have combined a detailed, high-resolution mitogenome analysis with summaries of autosomal data and Y-chromosome lineages to establish a settlement chronology for the Indian Subcontinent. Maternal lineages document the earliest settlement ~55-65 ka (thousand years ago), and major population shifts in the later Pleistocene that explain previous dating discrepancies and neutrality violation. Whilst current genome-wide analyses conflate all dispersals from Southwest and Central Asia, we were able to tease out from the mitogenome data distinct dispersal episodes dating from between the Last Glacial Maximum to the Bronze Age. Moreover, we found an extremely marked sex bias by comparing the different genetic systems. CONCLUSIONS: Maternal lineages primarily reflect earlier, pre-Holocene processes, and paternal lineages predominantly episodes within the last 10 ka. In particular, genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y-chromosome lineages, a smaller fraction of autosomal genome-wide variation and an even smaller fraction of mitogenomes across a vast swathe of Eurasia between 5 and 3.5 ka.

Hydrogen Peroxide, Povidone-Iodine and Chlorhexidine Fail to Eradicate Staphylococcus aureus Biofilm from Infected Implant Materials.

Hydrogen peroxide, povidone-iodine, and chlorhexidine are antiseptics that are commonly added to irrigants to either prevent or treat infection. There are little clinical data available that demonstrate efficacy of adding antiseptics to irrigants in the treatment of periprosthetic joint infection after biofilm establishment. The objective of the study was to assess the bactericidal activity of the antiseptics on S. aureus planktonic and biofilm. For planktonic irrigation, S. aureus was exposed to different concentrations of antiseptics. S. aureus biofilm was developed by submerging a Kirschner wire into normalized bacteria and allowing it to grow for forty-eight hours. The Kirschner wire was then treated with irrigation solutions and plated for CFU analysis. Hydrogen peroxide, povidone-iodine, and chlorhexidine were bactericidal against planktonic bacteria with over a 3 log reduction (p < 0.0001). Unlike cefazolin, the antiseptics were not bactericidal (less than 3 log reduction) against biofilm bacteria but did have a statistical reduction in biofilm as compared to the initial time point (p < 0.0001). As compared to cefazolin treatment alone, the addition of hydrogen peroxide or povidone-iodine to cefazolin treatment only additionally reduced the biofilm burden by less than 1 log. The antiseptics demonstrated bactericidal properties with planktonic S. aureus; however, when used to irrigate S. aureus biofilms, these antiseptics were unable to decrease biofilm mass below a 3 log reduction, suggesting that S. aureus biofilm has a tolerance to antiseptics. This information should be considered when considering antibiotic tolerance in established S. aureus biofilm treatment.

Prospective Activity of PLG0206, an Engineered Antimicrobial Peptide, on Chronic Periprosthetic Joint Infection Total Knee Arthroplasty Components Ex Vivo: The Knee Explant Analysis (KnEA) Study.

PLG0206 is an engineered antimicrobial peptide that has completed phase 1 clinical studies. A prospective study was completed on explanted implants from chronic periprosthetic joint infections (n = 17). At a concentration of 1 mg/mL for 15 min, there was a mean 4-log10 reduction (range, 1 to 7) in the bacterial CFU identified from the implants. IMPORTANCE Chronically infected prosthetics of the knee were exposed to PLG0206, an engineered antimicrobial peptide, at a concentration of 1 mg/mL for 15 min. A mean 4-log10 reduction (range, 1 to 7) in the number of bacteria occurred, which may translate to improved clinical outcomes for persons with prosthetic joint infection of the knee.

Direct antimicrobial activity of cationic amphipathic peptide WLBU2 against Staphylococcus aureus biofilms is enhanced in physiologic buffered saline.

Periprosthetic joint infection of total knee arthroplasties represents a major challenge to the field of orthopedic surgery. These infections are commonly associated with antibiotic-tolerant Staphylococcus aureus biofilms. Engineered cationic amphipathic peptide WLBU2 has shown the ability to kill antibiotic-resistant pathogens and drug-tolerant bacterial biofilms. The novelty of using WLBU2 during the direct irrigation and debridement of periprosthetic joint infections led our group to investigate the optimal washout conditions for treatment of S. aureus biofilms. S. aureus mature biofilms were grown on metal implant material and treated with WLBU2 dissolved in differing irrigation solvents. Mature biofilms were treated both in vitro as well as in a periprosthetic joint infection murine model. WLBU2 activity against S. aureus biofilms was increased when dissolved in diphosphate-buffered saline (dPBS) with pH of 7.0 compared with normal saline with pH of 5.5. WLBU2 activity was decreased in acidic dPBS and increased in alkaline dPBS. WLBU2 activity could be decreased in hypertonic dPBS and increased in hypotonic dPBS. WLBU2 dissolved in less acidic dPBS displayed increased efficacy in treating periprosthetic joint infection (PJI) implants ex vivo. WLBU2 demonstrated the ability to eliminate PJI associated S. aureus biofilms on arthroplasty material. The efficacy of engineered cationic amphipathic peptide WLBU2 for intraoperative elimination of S. aureus biofilms can be further optimized when kept in a less acidic and more physiologic pH adjusted saline. Understanding optimal physical washout conditions are vital for the success of WLBU2 in treating S. aureus biofilms in PJI clinical trials going forward.

A Curriculum to Increase Resident Scholarly Activity.

BACKGROUND AND OBJECTIVES: Scholarly activity (SA) is an Accreditation Council of Graduate Medical Education (ACGME) requirement for family medicine residents. Engaging residents in scholarly activity can be challenging. Naval Hospital Jacksonville Family Medicine Residency (NHJ) pioneered a curriculum that led to a dramatic, sustained increase in resident SA. We sought to implement the curriculum in other family medicine residency programs. METHODS: The curriculum was implemented at two additional family medicine residencies. Three curricular interventions were identified: a 3-hour case report workshop, a written practical guide to scholarly activity, and a resident peer research leader. One program implemented all three elements. The other implemented the workshop and written guide, but did not identify a resident peer leader. SA was measured using the annual ACGME program director report and compared the intervention year to the previous 3 years of SA using a 2-sample test for equality of proportions with continuity correction. We used pre- and postintervention surveys to evaluate resident attitudes about SA. RESULTS: The program implementing all three interventions increased residents' conference presentation 302% (n=34, P<.001). The program that did not identify a resident peer leader had no significant change in SA as reported to the ACGME. CONCLUSIONS: The curriculum was implemented in two additional residencies with promising results. We recommend further implementation across multiple sites to determine the extent to which the results are generalizable.

The In Vitro Efficacy of Doxycycline over Vancomycin and Penicillin in the Elimination of Cutibacterium Acnes Biofilm.

Cutibacterium acnes (formerly Propionibacterium acnes) is a significant pathogen in periprosthetic joint infections (PJIs) in total shoulder arthroplasty. Poor outcomes seen in PJIs are due to the established C. acnes bacterial biofilms. The prolonged nature of C. acnes infections makes them difficult to treat with antibiotics. The goal of this study was to determine the relative efficacy of vancomycin compared with penicillin and doxycycline against planktonic and mature biofilms. Clinical isolates from PJI patients as well as a laboratory strain of C. acnes were tested. Planktonic minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were obtained using modified clinical laboratory standard index assays. Biofilm MICs and MBCs were also obtained. The MIC was determined for both using the PrestoBlue viability stain. The MBC was determined using differential reinforced clostridial medium agar plates for colony-forming unit analysis. Using the PrestoBlue viability reagent, the planktonic MIC values for vancomycin were significantly higher than doxycycline. Across 10 strains of C. acnes, all three antibiotics had decreased efficacy when comparing planktonic and biofilm cultures. Although effective antibiotic doses ranged from 1 to 1,000 µg/mL, only doxycycline achieved inhibitory and bactericidal concentrations in all tested strains. Penicillin failed to achieve the minimum biofilm inhibitory concentration (MBIC) in 60% of tested strains, whereas vancomycin failed in 80% of tested strains. Penicillin, doxycycline, and vancomycin have similar abilities in inhibiting C. acnes growth planktonically. The MBIC for doxycycline was within the clinical dosing range, suggesting C. acnes biofilm offers minimal tolerance to these antibiotics. The MBIC for penicillin was within clinical dosing ranges in only 60% of trials, suggesting the relative tolerance of C. acnes to penicillin. The minimum biofilm bactericidal concentration (MBBC) of doxycycline showed efficacy in 90% of trials, whereas penicillin and vancomycin achieved MBBC in 15% of samples.

Staphylococcus epidermidis Biofilms Have a High Tolerance to Antibiotics in Periprosthetic Joint Infection.

Both Staphylococcus aureus and Staphylococcus epidermidis are commonly associated with periprosthetic joint infections (PJIs). The treatment of PJI can be challenging because biofilms are assumed to have an increased intolerance to antibiotics. This makes the treatment of PJI challenging from a clinical perspective. Although S. aureus has been previously demonstrated to have increased biofilm antibiotic tolerance, this has not been well established with Staphylococcus epidermidis. A prospective registry of PJI S. epidermidis isolates was developed. The efficacy of clinically relevant antibiotics was quantified against these isolates. S. epidermidis planktonic minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were collected using clinical laboratory standard index (CLSI) assays for eight antibiotics (doxycycline, vancomycin, daptomycin, clindamycin, rifampin, nafcillin, and trimethoprim/sulfamethoxazole). Mature biofilms were grown in vitro, after which minimum biofilm inhibitory concentration (MBIC) and minimum biofilm bactericidal concentration (MBBC) were quantified. Only rifampin and doxycycline had a measurable MBIC across all tested isolates. Based on MBBC, 64% of S. epidermidis biofilms could be eliminated by rifampin, whereas only 18% by doxycycline. S. epidermidis biofilm was observed to have a high tolerance to antibiotics as compared to planktonic culture. Isolate biofilm antibiotic tolerance varied to a larger degree than was seen in planktonic cultures.

Large variations in clinical antibiotic activity against Staphylococcus aureus biofilms of periprosthetic joint infection isolates.

Staphylococcus aureus biofilms have a high tolerance to antibiotics, making the treatment of periprosthetic joint infection (PJI) challenging. From a clinical perspective, bacteria from surgical specimens are cultured in a planktonic state to determine antibiotic sensitivity. However, S. aureus exists primarily as established biofilms in PJI. To address this dichotomy, we developed a prospective registry of total knee and hip arthroplasty PJI S. aureus isolates to quantify the activity of clinically important antibiotics against isolates grown as biofilms. S. aureus planktonic minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using clinical laboratory standard index assays for 10 antibiotics (cefazolin, clindamycin, vancomycin, rifampin, linezolid, nafcillin, gentamicin, trimethoprim/sulfamethoxazole, doxycycline, and daptomycin). Mature biofilms of each strain were grown in vitro, after which biofilm MIC (MBIC) and biofilm MBC (MBBC) were determined. Overall, isolates grown as biofilms displayed larger variations in antibiotic MICs as compared to planktonic MIC values. Only rifampin, doxycycline, and daptomycin had measurable biofilm MIC values across all S. aureus isolates tested. Biofilm MBC observations complemented biofilm MIC observations; rifampin, doxycycline, and daptomycin were the only antibiotics with measurable biofilm MBC values. 90% of S. aureus biofilms could be killed by rifampin, 50% by doxycycline, and only 15% by daptomycin. Biofilm formation increased bacterial antibiotic tolerance nonspecifically across all antibiotics, in both MSSA and MRSA samples. Rifampin and doxycycline were the most effective antibiotics at killing established S. aureus biofilms. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1604-1609, 2019.

Understanding the Impact of Hazardous and Harmful Use of Alcohol and/or Other Drugs on ARV Adherence and Disease Progression.

The objective of this study was to understand the impact of hazardous and harmful use of alcohol and/or other drugs on ARV adherence and disease progression among HIV patients. A cross-sectional study design was used. A total of 1503 patients attending HIV clinics in Cape Town, South Africa were screened for problematic substance use. A sub-sample of 607 patients (303 patients who screened positive for problematic substance use and 304 who did not) participated in this study. Hazardous or harmful alcohol use and problematic drug use predicted missing and stopping ARVs which, in turn, was associated with a decrease in CD4 counts and more rapid HIV-disease progression and poorer health outcomes in people living with HIV/AIDS (PLWHA). The findings of this study underscore the need for an integrated approach to managing substance-use disorders in PLWHA.

Contrasting physiological responses of two co-occurring eucalypts to seasonal drought at restored bauxite mine sites.

This study describes the physiological response of two co-occurring tree species (Eucalyptus marginata and Corymbia calophylla) to seasonal drought at low- and high-quality restored bauxite mine sites in south-western Australia. Seasonal changes in photosynthesis (A), stomatal conductance (g(s)), leaf water potential (ψ), leaf osmotic potential (ψ), leaf relative water content (RWC) and pressure-volume analysis were captured over an 18-month field study to (i) determine the nature and severity of physiological stress in relation to site quality and (ii) identify any physiological differences between the two species. Root system restriction at the low-quality site reduced maximum rates of gas exchange (g(s) and A) and increased water stress (midday ψ and daily RWC) in both species during drought. Both species showed high stomatal sensitivity during drought; however, E. marginata demonstrated a higher dehydration tolerance where ψ and RWC fell to -3.2 MPa and 73% compared with -2.4 MPa and 80% for C. calophylla. Corymbia calophylla showed lower g(s) and higher ψ and RWC during drought, indicating higher drought tolerance. Pressure-volume curves showed that cell-wall elasticity of E. marginata leaves increased in response to drought, while C. calophylla leaves showed lower osmotic potential at zero turgor in summer than in winter, indicating osmotic adjustment. Both species are clearly able to tolerate seasonal drought at hostile sites; however, by C. calophylla closing stomata earlier in the drought cycle, maintaining a higher water status during drought and having the additional mechanism of osmotic adjustment, it may have a greater capacity to survive extended periods of drought.

Lumbar flexion and dynamic EMG among persons with single level disk herniation pre- and postsurgery with radicular low-back pain.

OBJECTIVE: The paraspinal muscles often fail to relax on forward flexion in many persons with low-back pain. The goal of this prospective study was to determine whether this abnormal lack of a flexion-relaxation phenomenon corrects after lumbar diskectomy for symptoms of radiculopathy with low-back pain. DESIGN: Electromyographic testing was performed on 17 patients before and 30 days after lumbar diskectomy. RESULTS: Although pain improved significantly (P < 0.05), the flexion-relaxation phenomenon did not improve. CONCLUSIONS: Failure to recover muscle relaxation while pain is relieved suggests another mechanism for paraspinal activity.

Alterations of F wave parameters after exercise in symptomatic lumbar spinal stenosis.

OBJECTIVES: The purpose of the study is to investigate changes in F wave parameters after exercise in subjects with symptomatic lumbar spinal stenosis. DESIGN: A total of 19 older patients with lumbar spinal stenosis and neurogenic claudication participated in this cohort study. No one withdrew for adverse effects. All subjects underwent physical therapy, with half performing additional interval-walking exercises. Groups were treated for eight sessions, returning for follow-up at weeks 4 and 8. Changes in F wave indices--minimal latency, chronodispersion, and persistence--were calculated. The treatment group demonstrated worsening of F wave persistence at 8-wk follow-up (P < 0.01). CONCLUSIONS: F wave indices worsened after an interval-walking exercise program. Subjects in the treatment group demonstrated worsening of F wave persistence at 8-wk follow-up.

Diversity of mycorrhizal fungi of terrestrial orchids: compatibility webs, brief encounters, lasting relationships and alien invasions.

The diversity of mycorrhizal fungi associated with an introduced weed-like South African orchid (Disa bracteata) and a disturbance-intolerant, widespread, native West Australian orchid (Pyrorchis nigricans) were compared by molecular identification of the fungi isolated from single pelotons. Molecular identification revealed both orchids were associated with fungi from diverse groups in the Rhizoctonia complex with worldwide distribution. Symbiotic germination assays confirmed the majority of fungi isolated from pelotons were mycorrhizal and a factorial experiment uncovered complex webs of compatibility between six terrestrial orchids and 12 fungi from Australia and South Africa. Two weed-like (disturbance-tolerant rapidly spreading) orchids - D. bracteata and the indigenous Australian Microtis media, had the broadest webs of mycorrhizal fungi. In contrast, other native orchids had relatively small webs of fungi (Diuris magnifica and Thelymitra crinita), or germinated exclusively with their own fungus (Caladenia falcata and Pterostylis sanguinea). Orchids, such as D. bracteata and M. media, which form relationships with diverse webs of fungi, had apparent specificity that decreased with time, as some fungi had brief encounters with orchids that supported protocorm formation but not subsequent seedling growth. The interactions between orchid mycorrhizal fungi and their hosts are discussed.

Paraspinal electromyography that compares concentric with monopolar needles: a blinded study.

OBJECTIVE: To establish interrater reliability for paraspinal muscle needle electromyography study with both monopolar and concentric needles in symptomatic and asymptomatic persons and to further establish normative data for paraspinal needle study. DESIGN: At a university spine center, participants with and without radiating low back pain were evaluated with the mini-paraspinal mapping paraspinal needle technique by an unblinded and a blinded electromyographer. RESULTS: In the symptomatic group, the intraclass correlation coefficient between concentric and monopolar needles was 0.793; between monopolar needles, it was 0.876; and between concentric needles, it was 0.966. In the asymptomatic group, the mean total score was 0.25. CONCLUSIONS: The good interrater reliability with the same needle type helps support the validity of the needle electromyography study of the paraspinal muscles. The good correlation between the concentric and monopolar needles shows the data published using monopolar needle data also apply to studies using paraspinal needle electromyography with concentric needles. The low score with the asymptomatic group reaffirms that using a cutoff score of >2 as abnormal has a false-positive rate of <5%.

Effects of atmospheric ozone on microarray data quality.

A data anomaly was observed that affected the uniformity and reproducibility of fluorescent signal across DNA microarrays. Results from experimental sets designed to identify potential causes (from microarray production to array scanning) indicated that the anomaly was linked to a batch process; further work allowed us to localize the effect to the posthybridization array stringency washes. Ozone levels were monitored and highly correlated with the batch effect. Controlled exposures of microarrays to ozone confirmed this factor as the root cause, and we present data that show susceptibility of a class of cyanine dyes (e.g., Cy5, Alexa 647) to ozone levels as low as 5-10 ppb for periods as short as 10-30 s. Other cyanine dyes (e.g., Cy3, Alexa 555) were not significantly affected until higher ozone levels (> 100 ppb). To address this environmental effect, laboratory ozone levels should be kept below 2 ppb (e.g., with filters in HVAC) to achieve high quality microarray data.