Workers' Compensation: The Burden on Healthcare Resource Utilization After Foot and Ankle Surgery.

INTRODUCTION: The purpose of this study is to investigate the amount of healthcare resources dedicated to patients with WC after common foot or ankle procedures compared with a procedure-matched control group. METHODS: A retrospective review was performed of patients with WC and without WC undergoing foot and ankle procedures. Measures of healthcare burden included clinical communications, documents, prescriptions, office visits, and days to return to work and clinic discharge. RESULTS: Collectively, 142 patients met the inclusion criteria. Patients with workers' compensation had increased office communication encounters (P < 0.001), processed documents (P < 0.001), medication prescriptions (P < 0.001), number of office visits (P < 0.001), number of days until return to work (P < 0.001), and days until final disposition from clinic (P < 0.001). Patients with workers' compensation were more likely to have postoperative complications (OR 2.1; 95% CI, 1.0 to 4.3; P = 0.04), secondary surgeries (OR 8.2; 95% CI, 2.3 to 29.4; P < 0.001), and new complaints during the perioperative period (OR 1.9; 95% CI, 0.9 to 4.0; P = 0.07) but were less likely to cancel appointments (OR 0.41; 95% CI, 0.19 to 0.86; P = 0.02). DISCUSSION: When undergoing common foot and ankle orthopaedic procedures, patients with WC demonstrated increased healthcare utilization of resources. This included more office staff work burden dedicated to patients with WC for longer amounts of time, effectively doubling the effort of a non-WC cohort.

Does One Size Fit All? Variations in the DNA Barcode Gaps of Macrofungal Genera.

The nuclear ribosomal internal transcribed spacer (nrITS) region has been widely used in fungal diversity studies. Environmental metabarcoding has increased the importance of the fungal DNA barcode in documenting fungal diversity and distribution. The DNA barcode gap is seen as the difference between intra- and inter-specific pairwise distances in a DNA barcode. The current understanding of the barcode gap in macrofungi is limited, inhibiting the development of best practices in applying the nrITS region toward research on fungal diversity. This study examined the barcode gap using 5146 sequences representing 717 species of macrofungi from eleven genera, eight orders and two phyla in datasets assembled by taxonomic experts. Intra- and inter-specific pairwise distances were measured from sequence and phylogenetic data. The results demonstrate that barcode gaps are influenced by differences in intra- and inter-specific variance in pairwise distances. In terms of DNA barcode behavior, variance is greater in the ITS1 than ITS2, and variance is greater in both relative to the combined nrITS region. Due to the difference in variance, the barcode gaps in the ITS2 region are greater than in the ITS1. Additionally, the taxonomic approach of "splitting" taxa into numerous taxonomic units produces greater barcode gaps when compared to "lumping". The results show variability in the barcode gaps between fungal taxa, demonstrating a need to understand the accuracy of DNA barcoding in quantifying species richness. For taxonomic studies, variability in nrITS sequence data supports the application of multiple molecular markers to corroborate the taxonomic and systematic delineation of species.

A radiologic determination of the different screw cutting patterns in cut and uncut orthopedic cortical screws using a novel imaging technique.

OBJECTIVE: We hypothesize that cut screws will deform in a manner that increases the core and outer diameters of the screw hole compared to uncut controls, and effects will be more pronounced in titanium screws. MATERIALS AND METHODS: We used biomechanical polyurethane foam blocks to simulate cortical bone. We organized four groups of stainless steel and titanium cut and uncut screws. Blocks were fitted with a jig to ensure perpendicular screw insertion. We imaged the blocks using digital mammography and measured them using PACS software. Power analysis determined a power of 0.95 and an alpha error of 0.05. RESULTS: Highly statistically significant differences in core diameter were found after cutting stainless steel and titanium screws. Cutting stainless steel screws increased core diameter by 0.30 mm (95% CI, 0.16 to 0.45; p < .001). Titanium screws' core diameter increased by 0.45 mm (95% CI, 0.30 to 0.61; p < .001). No significant differences were found in the outer diameters of stainless steel and titanium screws after cutting. CONCLUSION: Titanium and stainless steel screw tracts demonstrated screw core diameter and screw thread pattern deformation after cutting. Titanium screws demonstrated more significant effects.

Transversus Abdominis Plane Block as Part of a Multimodal Analgesic Regimen in Patients Undergoing Anterior Lumbar Interbody Fusion: A Retrospective Cohort Study.

BACKGROUND: Opioids are a mainstay for pain control in patients undergoing lumbar spine surgery but are associated with a high risk of dependence and significant adverse effects. Efforts continue to be made to utilize non-narcotic agents such as regional nerve block for pain control as part of a multimodal analgesia regimen. Recently, transversus abdominis plane (TAP) blocks have proven beneficial for patients undergoing lumbar fusion procedures. The purpose of this study is to evaluate the efficacy of TAP blocks for postoperative pain control and the effect on opioid consumption and hospital length of stay (LOS) in patients undergoing anterior lumbar interbody fusion (ALIF). METHODS: A retrospective review of patients undergoing elective ALIF included collection of data on demographics, LOS, pain scores using visual analog scale (VAS), opioid consumption using morphine milligram equivalents (MME) from postoperative day (POD) 0 to 5, and any complications. Patients who underwent primary ALIF or ALIF with concomitant posterolateral lumbar fusion were included. RESULTS: A total of 99 patients met inclusion criteria; 47 had a preoperative TAP block and 52 did not. Demographic data and number of levels fused were equally distributed between the groups. The TAP group had significantly lower MME consumption postoperatively during POD 0 to 2 and 0 to 5. VAS pain scores were lower for TAP block patients on POD 3 and 4; otherwise, there was no significant difference. LOS and complication rates were not significantly different. A multiple regression analysis found male sex to be a predictor of increased postoperative MME, while age and TAP block were significant predictors of decreased MME. CONCLUSIONS: The use of TAP block for patients undergoing ALIF was associated with less cumulative MME consumption in the immediate postoperative period. TAP block may be an effective tool for reducing postoperative opioid consumption in patients undergoing ALIF. CLINICAL RELEVANCE: The data in this study provide clinical relevance supporting the use of TAP blocks for patients undergoing ALIF procedures.

Postoperative Infection and Revision Surgery Rates in Foot and Ankle Surgery Without Routine Prescription of Prophylactic Antibiotics.

INTRODUCTION: Surgical site infections (SSIs) are associated with patient morbidity and increased healthcare costs. Limited literature in foot and ankle surgery provides guidance about routine administration of postoperative antibiotic prophylaxis. The purpose of this study was to examine the incidence and revision surgery rates of SSI in outpatient foot and ankle surgeries in patients not receiving oral postoperative antibiotic prophylaxis. METHODS: A retrospective review of all outpatient surgeries (n = 1517) conducted by a single surgeon in a tertiary referral academic center was conducted through electronic medical records. Incidence of SSI, revision surgery rate, and associated risk factors were determined. The median follow-up was 6 months. RESULTS: Postoperative infection occurred in 2.9% (n = 44) of the surgeries conducted, with 0.9% of patients (n = 14) requiring return to the operating room. Thirty patients (2.0%) were diagnosed with simple superficial infections, which resolved with local wound care and oral antibiotics. Diabetes (adjusted odds ratio, 2.09; 95% confidence interval, 1.00 to 4.38; P = 0.049) and increasing age (adjusted odds ratio, 1.02; 95% confidence interval, 1.00 to 1.04; P = 0.016) were significantly associated with postoperative infection. DISCUSSION: This study demonstrated low postoperative infection and revision surgery rates without the routine prescription of prophylactic postoperative antibiotics. Increasing age and diabetes are signficant risk factors for developing a postoperative infection.

Applying a modified metabarcoding approach for the sequencing of macrofungal specimens from fungarium collections.

Premise: Fungaria are an underutilized resource for understanding fungal biodiversity. The effort and cost of producing DNA barcode sequence data for large numbers of fungal specimens can be prohibitive. This study applies a modified metabarcoding approach that provides a labor-efficient and cost-effective solution for sequencing the fungal DNA barcodes of hundreds of specimens at once. Methods: We applied a two-step PCR approach using nested, barcoded primers to sequence the fungal nrITS2 region of 766 macrofungal specimens using the Illumina platform. The specimens represent a broad taxonomic sampling of the Dikarya. Of these, 382 Lactarius specimens were analyzed to identify molecular operational taxonomic units (MOTUs) using a phylogenetic approach. The raw sequences were trimmed, filtered, assessed, and analyzed using the DADA2 amplicon de-noising toolkit and Biopython. The sequences were compared to the NCBI and UNITE databases and Sanger nrITS sequences from the same specimens. Results: The taxonomic identities derived from the nrITS2 sequence data were >90% accurate across all specimens sampled. A phylogenetic analysis of the Lactarius sequences identified 20 MOTUs. Discussion: The results demonstrate the capacity of these methods to produce nrITS2 sequences from large numbers of fungarium specimens. This provides an opportunity to more effectively use fungarium collections to advance fungal diversity identification and documentation.

Topical Antibiotic Powder and Nonunion Risk in Surgically Treated Tibial Plateau and Pilon Fractures.

INTRODUCTION: High-energy periarticular tibia fractures are challenging injuries with a significant risk of complications. Postoperative infection rates, although improved, remain unacceptable. Intrawound topical antibiotic (TA) application has been popularized to reduce postoperative infections. Although TA may minimize infections, it remains unclear whether TAs have any impact on the development of nonunion. Recent investigations of TA use in fracture care have questioned its efficacy in vivo and suggested a potentially deleterious effect on fracture healing. This study investigates the impact of TA on nonunion rates in surgically treated high-energy periarticular tibia fractures. METHODS: Retrospective analysis of surgically treated periarticular tibia fractures at a single Level 1 trauma center was conducted. Intervention in question was the clinical effect of intrawound TA powder application at definitive closure. A total of 222 high-energy periarticular tibia fractures were included, 114 with TA use and 108 without. The primary outcome was the occurrence of nonunion, with secondary outcomes being superficial and deep postoperative surgical site infections. RESULTS: Twenty-seven patients (12.1%) were diagnosed with nonunions (14 pilons and 13 plateaus). There was no statistically significant difference in nonunion rates among patients who received topical antibiotics (15.8%) versus the group of patients who did not (8.3%) ( P = 0.23). Odds of developing nonunion was significant for open injuries (odds ratio 6.16, P < 0.001) and patients with a provisional external fixator (odds ratio 8.72, P = 0.03) before definitive fixation. No notable difference in the number of superficial and deep infections was identified between groups. CONCLUSION: The use of TA in high-energy periarticular tibia fractures showed no statistically significant increase in nonunion rates but did not conclusively rule out nonunion as a possible effect of intrawound TA. Additional large-scale multicenter prospective studies are needed to confirm these findings. The current body of literature regarding high-energy periarticular tibia fractures does suggest that TAs lower the risk of postoperative infections, but the nonunion risk remains unclear. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Intraoperative Methadone Reduces Postoperative Opioid Requirements in Nuss Procedure for Pectus Excavatum.

INTRODUCTION: Surgical correction of pectus excavatum by Nuss procedure, commonly referred to as minimally invasive repair of pectus excavatum (MIRPE), often results in significant postoperative pain. This study investigated whether adding intraoperative methadone would reduce the postoperative opioid requirement during admission for patients undergoing MIRPE. METHODS: A retrospective cohort chart review was conducted for 40 MIRPE patients between 2018 and 2020. Patients were stratified into 2 groups: those who received multimodal anesthesia (MM, n = 20) and those who received multimodal anesthesia with the addition of intraoperative methadone (MM + M, n = 20). Data collected included total opioid consumption during hospital stay (morphine milligram equivalents [MMEs]), hospital length of stay (LOS), pain scores, time to ambulation, and time to tolerating solid food. RESULTS: Addition of intraoperative methadone for patients undergoing MIRPE significantly reduced postoperative opioid requirements (MME/kg) during admission (P = .007). On average, patients in the MM group received 1.61 ± .55 MME/kg while patients in the MM + M group received 1.16 ± .44 MME/kg. Hospital opioid (non-methadone) total was also significantly reduced between the MM (1.87 ± .54) and MM + M group (1.37 ± .46), P = .003. There was no significant difference in hospital opioid total MME/kg administered between the groups. There were no significant differences observed in hospital LOS, pain scores, time to ambulation, or time to toleration of solid food. DISCUSSION: Incorporating intraoperative methadone for patients undergoing MIRPE reduced postoperative opioid requirements and hospital opioid (non-methadone) totals without a significant change in pain scores. Patients undergoing the Nuss procedure may benefit from the administration of intraoperative methadone.

Ultrasound may safely replace chest radiograph after tube thoracostomy removal in trauma patients.

INTRODUCTION: A chest radiograph (CXR) is routinely obtained in trauma patients following tube thoracostomy (TT) removal to assess for residual pneumothorax (PTX). New literature supports the deference of a radiograph after routine removal procedure. However, many surgeons have hesitated to adopt this practice due to concern for patient welfare and medicolegal implications. Ultrasound (US) is a portable imaging modality which may be performed rapidly, without radiation exposure, and at minimal cost. We hypothesized that transitioning from CXR to US following TT removal in trauma patients would prove safe and provide superior detection of residual PTX. MATERIALS AND METHODS: A practice management guideline was established calling for the performance of a CXR and bedside US 2 h after TT removal in all adult trauma patients diagnosed with PTX at a level 1 trauma center. Surgical interns completed a 30-minute, US training course utilizing a handheld US device. US findings were interpreted and documented by the surgical interns. CXRs were interpreted by staff radiologists blinded to US findings. Data was retrospectively collected and analyzed. RESULTS: Eighty-nine patients met inclusion criteria. Thirteen (15%) post removal PTX were identified on both US and CXR. An additional 11 (12%) PTX were identified on CXR, and 5 (6%) were identified via US, for a total of 29 PTX (33%). One patient required re-intervention; the recurrent PTX was detected by both US and CXR. For all patients, using CXR as the standard, US displayed a sensitivity of 54.2%, specificity of 92.3%, negative predictive value of 84.5%, and positive predictive value of 72.2%. The cost of care for the study cohort may have been reduced over $9,000 should US alone have been employed. CONCLUSION: Bedside US may be an acceptable alternative to CXR to assess for recurrent PTX following trauma TT removal.

Quadruple Hamstring Autograft Technique for Anterior Cruciate Ligament Reconstruction Reduces Allograft Augmentation.

Purpose: To assess the discrepancy in graft diameter between double- and quadruple-folded hamstring autografts and the need for allograft augmentation to obtain an adequate graft diameter during arthroscopic anterior cruciate ligament reconstruction. Methods: All patients undergoing anterior cruciate ligament reconstruction with hamstring autograft between 2017 and 2021 at a single institution by a single surgeon were identified. The surgeon changed from double-folded hamstring autograft to quadruple-folded hamstring autograft within the study period. Results: A total of 191 patients were identified, of whom 57 received double-folded autografts and 134 quadruple-folded autografts. Patient characteristics between cohorts were similar. Median double-folded graft size (7.5 mm; interquartile range, 7.0-8.0 mm) was significantly thinner than the quadruple-folded graft size (9 mm; interquartile range, 8.5-9.5 mm, P = .001). Quadruple-folded autograft was less likely to require an allograft augmentation than the double-folded autograft (0.7% vs 26.3%) (odds ratio 0.02; 95% confidence interval 0.00-0.16; P < .001). Conclusions: Quadruple-folded hamstring autograft provides a larger graft diameter and reduced need for allograft augmentation. Level of Evidence: Level III, retrospective comparative study.

Synovial chondromatosis of the flexor hallucis longus tendon sheath.

This case report discusses a rare case of secondary tenosynovial chondromatosis of the flexor hallucis longus (FHL). Synovial chrondomatosis is a rare, benign proliferative cartilaginous lesion arising from the synovial tissue or bursal lining of or near joints. When it is extra-articular, it is considered tenosynovial chondromatosis. The diagnosis is often delayed given the rarity of presentation and non-specific symptoms. The case was highly unusual in that hindfoot pain was caused by several centimetre-sized osteochondral bodies within the FHL tendon sheath. Anterior cheilectomy was performed. The patient returned to full activity following surgery without recurrence of the disease. The condition can be successfully treated operatively.

Host Shift Speciation of the Ectomycorrhizal Genus Suillus (Suillineae, Boletales) and Biogeographic Comparison With Its Host Pinaceae.

Suillus is a genus of ectomycorrhizal fungi associated almost exclusively with Pinaceae. Lack of sample collections in East Asia and unresolved basal phylogenetic relationships of the genus are the major obstacles for better understanding the Suillus evolution. A resolved phylogeny of Suillus representing global diversity was achieved by sequencing multiple nuclear ribosomal and protein coding genes and extensive samples collected in East Asia. Fungal fossils are extremely rare, and the Eocene ectomycorrhizal symbiosis (ECM) fossil of Pinus root has been widely used for calibration. This study explored an alternative calibration scenario of the ECM fossil for controversy. Ancestral host associations of Suillus were estimated by maximum likelihood and Bayesian Markov chain Monte Carlo (MCMC) analyses, inferred from current host information from root tips and field observation. Host shift speciation explains the diversification of Suillus major clades. The three basal subgenera of Suillus were inferred to be associated with Larix, and diverged in early Eocene or Upper Cretaceous. In the early Oligocene or Paleocene, subgenus Suillus diverged and switched host to Pinus subgenus Strobus, and then switched to subgenus Pinus four times. Suillus subgenus Douglasii switched host from Larix to Pseudotsuga in Oligocene or Eocene. Increased species diversity occurred in subgenus Suillus after it switched host to Pinus but no associated speciation rate shifts were detected. Ancestral biogeographic distributions of Suillus and Pinaceae were estimated under the Dispersal Extinction Cladogenesis (DEC) model. Ancestral distribution patterns of Suillus and Pinaceae are related but generally discordant. Dispersals between Eurasia and North America explain the prevalence of disjunct Suillus taxa.

Perceptual-Motor Efficiency and Concussion History Are Prospectively Associated With Injury Occurrences Among High School and Collegiate American Football Players.

BACKGROUND: After a sport-related concussion (SRC), the risk for lower extremity injury is approximately 2 times greater, and the risk for another SRC may be as much as 3 to 5 times greater. PURPOSE: To assess the predictive validity of screening methods for identification of individual athletes who possess an elevated risk of SRC. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Metrics derived from a smartphone flanker test software application and self-ratings of both musculoskeletal function and overall wellness were acquired from American high school and college football players before study participation. Occurrences of core or lower extremity injury (CLEI) and SRC were documented for all practice sessions and games for 1 season. Receiver operating characteristic and logistic regression analyses were used to identify variables that provided the greatest predictive accuracy for CLEI or SRC occurrence. RESULTS: Overall, there were 87 high school and 74 American college football players included in this study. At least 1 CLEI was sustained by 45% (39/87) of high school players and 55% (41/74) of college players. Predictors of CLEI included the flanker test conflict effect ≥69 milliseconds (odds ratio [OR], 2.12; 90% CI, 1.24-3.62) and a self-reported lifetime history of SRC (OR, 1.70; 90% CI, 0.90-3.23). Of players with neither risk factor, only 38% (29/77) sustained CLEI compared with 61% (51/84) of players with 1 or both of the risk factors (OR, 2.56; 90% CI, 1.50-4.36). SRC was sustained by 7 high school players and 3 college players. Predictors of SRC included the Overall Wellness Index score ≤78 (OR, 9.83; 90% CI, 3.17-30.50), number of postconcussion symptoms ≥4 (OR, 8.35; 90% CI, 2.71-25.72), the Sport Fitness Index score ≤78 (OR, 5.16; 90% CI, 1.70-15.65), history of SRC (OR, 4.03; 90% CI, 1.35-12.03), and the flanker test inverse efficiency ratio ≥1.7 (OR, 3.19; 90% CI, 1.08-9.47). CONCLUSION: Survey responses and smartphone flanker test metrics predicted greater injury incidence among individual football players classified as high-risk compared with that for players with a low-risk profile.

Novel Laccaria Species From Juglandaceae Forest in Panama With Notes on Their Ecology.

Since 2013 there have been 22 new species of Laccaria described worldwide. Only three of these represent species from the neotropics. In Panama, Laccaria is abundant in monodominant Oreomunnea mexicana (Juglandaceae) forests based on sporocarps and environmental sequencing of roots. This study uses a combination of morphological and phylogenetic evidence to document up to seven species of Laccaria from these forests, one previously described, three described as new, and three requiring more data before being formally described. Molecular data used for phylogenetic analysis include the nuclear ribosomal ITS and 28S regions, along with TEF1 and RPB2. Laccaria stellata, has previously been reported from O. mexicana cloud forests of Panama. Laccaria dallingii sp. nov., L. nitrophila sp. nov., and L. fortunensis sp. nov. are described as new based on morphology and phylogenetic analysis of multiple collections. A taxon referred to as "PAN sp3" is resolved sister to L. stellata. Phylogenetic analysis also resolved two separate clades of Panamanian Laccaria as sister to L. roseoalbescens, a species previously described from Mexico. These three taxa are not described in this paper as there is too little material from which to make effective morphological descriptions even though their placement in phylogenetic analysis identify them as being unique. Ecologically, all described species except for L. fortunensis were amplified from O. mexicana ectomycorrhizal root tips. L. nitrophila was one of the most recovered species from the roots of O. mexicana in a previous study, and it has been shown to respond positively to long term nitrogen addition. Our results expand the knowledge of Laccaria diversity for Central America and highlight that at least some species of Laccaria are nitrophilic in neotropical Juglandaceae forests as well as in temperate forests.

Cigarette Smoking Is Associated With Lower Quadriceps Cross-sectional Area and Attenuation in Older Adults.

INTRODUCTION: In addition to well-established links with cardiovascular and respiratory diseases, cigarette smoking may affect skeletal muscle; however, associations with quadriceps atrophy, density, and function are unknown. This study explored the associations of current and former smoking with quadriceps muscle area and attenuation as well as muscle force (assessed as knee extension peak torque) and rate of torque development-a measure of muscle power in older adults. METHODS: Data from 4469 older adults, aged 66-95 years at baseline in the Age, Gene/Environment Susceptibility-Reykjavik Study with measurements of thigh computed tomography, isometric knee extension testing, self-reported smoking history, and potential covariates were analyzed. RESULTS: Sex differences were observed in these data; therefore, our final analyses are stratified by sex. In men, both former smokers and current smokers had lower muscle area (with ß= -0.10, 95% confidence interval [CI] = -0.17 to -0.03 and ß = -0.19, 95% CI = -0.33 to -0.05, respectively) and lower muscle attenuation (ie, higher fat infiltration, ß = -0.08, 95% CI = -0.16 to -0.01 and ß = -0.17, 95% CI = -0.34 to -0.01, respectively) when compared with never smokers. Smoking status was not associated with male peak torque or rate of torque development. In women, current smoking was associated with lower muscle attenuation (ß = -0.24, 95% CI = -0.34 to -0.13) compared to never smoking. Among female smokers (current and former), muscle attenuation and peak torque were lower with increasing pack-years. CONCLUSIONS: Results suggest that cigarette smoking is related to multiple muscle properties at older age and that these relationships may be different among men and women. IMPLICATIONS: This article presents novel data, as it examined for the first time the relationship between smoking and computed tomography-derived quadriceps muscle size (cross-sectional area) and attenuation. This study suggests that current cigarette smoking is related to higher muscle fat infiltration, which may have significant health implications for the older population, because of its known association with poor physical function, falls, and hip fractures.

Addressing the diversity of Xylodon raduloides complex through integrative taxonomy.

In this study, the taxonomic diversity of the Xylodon raduloides species complex (Hymenochaetales, Basidiomycota) is examined. Specimens were studied using an integrative taxonomic approach that includes molecular phylogenetic and morphological analyses, and environmental niche comparisons. Four different species were found inside the Xylodon raduloides complex, with a biogeographic distribution pattern bound by geographic regions: Europe, North America, Patagonia, and Australia-New Zealand. Molecular, morphological, and environmental evidences delimit two lineages within this complex: a Northern Hemisphere clade with longer basidiospores and wider ranges in temperature and precipitation tolerance, and a Southern Hemisphere clade with smaller and more spherical basidiospores, and an isothermal and more humid climate preference. The integrative taxonomic approach used in this study demonstrates congruence between data sets and shows how morphological and environmental characteristics contribute to the differentiation of fungal species complexes. By combining various sources of taxonomic information, three new species are described: Xylodon laurentianus, X. novozelandicus, and X. patagonicus.

A systematic revision of the ectomycorrhizal genus Laccaria from Korea.

Species of Laccaria (Hydnangiaceae, Basidiomycota) are important in forest ecosystems as ectomycorrhizal fungi. Nine of the 75 described Laccaria species worldwide been reported from Korea. Most of these have European and North American names, and their identities are based solely on morphological features. To evaluate the taxonomy of Korean Laccaria, we used 443 specimens collected between 1981 and 2016 in a phylogenetic analysis based on sequence data from nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 rDNA (ITS) region, nuc 28S rDNA (28S), RNA polymerase II subunit 2 (rpb2), and translation elongation factor 1-α (tef1). Ten Laccaria species were identified. Three of these were previously reported from Korea: L. bicolor, L. tortilis, and L. vinaceoavellanea. Laccaria alba, L. japonica, and L. murina are confirmed as new reports from Korea. Lastly, four new Laccaria species are described: L. araneosa, L. parva, L. torosa, and L. versiforma. This study supports the general contention that Asian species of ectomycorrhizal fungi may not be conspecific with morphologically similar species from Europe and North America. Furthermore, identification based on morphology alone is often unreliable in Laccaria due to considerable overlap of characters among species. Thus, use of molecular methods is necessary for effective identification. Illustrations of the four newly described species and a taxonomic key to species of Laccaria in Korea are provided.

Associations Between Lean Mass, Muscle Strength and Power, and Skeletal Size, Density and Strength in Older Men.

Studies examining the relationship between muscle parameters and bone strength have not included multiple muscle measurements and/or both central and peripheral skeletal parameters. The purpose of this study was to explore the relationship between lean mass, muscle strength and power, and skeletal size, bone density, and bone strength. We studied the association between appendicular lean mass (ALM), grip strength, and leg power, and central quantitative computed tomography (QCT) parameters in 2857 men aged 65 years or older; peripheral QCT was available on a subset (n = 786). ALM, grip strength, and leg power were measured by dual-energy X-ray absorptiometry (DXA), Jamar dynamometer, and the Nottingham Power Rig, respectively. Multivariable models adjusting for potential confounders including age, race, study site, BMI, and muscle measurements were developed and least squares means were generated from linear regression models. For the multivariable model, percent differences of bone parameters between lowest (Q1) and highest quartiles (Q4) of ALM, grip strength, and leg power were reported. ALM was significantly associated with central and peripheral QCT parameters: percent higher values (Q4 versus Q1) ranging from 3.3% (cortical volumetric bone mineral density [vBMD] of the femoral neck) to 31% (vertebral strength index of the spine). Grip strength was only significantly associated with radial parameters: percent higher values (Q4 versus Q1) ranging from 2.5% (periosteal circumference) to 7.5% (33% axial strength index [SSIx]). Leg power was associated with vertebral strength and lower cross-sectional area with percent lower values (Q4 versus Q1) of -11.9% and -2.7%, respectively. In older men, stronger associations were observed for ALM compared to muscle strength and power. Longitudinal studies are needed to examine the relationship between independent changes in muscle measurements and skeletal size, density and strength. © 2018 American Society for Bone and Mineral Research.

Associations of Quadriceps Torque Properties with Muscle Size, Attenuation, and Intramuscular Adipose Tissue in Older Adults.

Background: Atrophy and fatty infiltration of muscle with aging are associated with fractures and falls, however, their direct associations with muscle function are not well described. It was hypothesized that participants with lower quadriceps muscle attenuation, area, and greater intramuscular adipose tissue (IMAT) will exhibit slower rates of torque development (RTD) and lower peak knee extension torques. Methods: Data from 4,842 participants (2,041 men, 2,801 women) from the Age Gene/Environment Susceptibility Reykjavik Study (mean age 76 ± 0.1 years) with complete thigh computed tomography and isometric knee testing. Regression models were adjusted for health, behavior, and comorbidities. Muscle attenuation was further adjusted for muscle area and IMAT; muscle area adjusted for IMAT and attenuation; and IMAT adjusted for muscle area and attenuation. Standardized betas (ß) indicate association effect sizes. Results: In the fully-adjusted models, attenuation (men ß = 0.06, 95% CI: 0.01, 0.11; women ß = 0.07, 95% CI: 0.03, 0.11) and muscle area (men ß = 0.13, 95% CI: 0.07, 0.19; women ß = 0.10, 95% CI: 0.06, 0.15) were associated with knee RTD. Attenuation (men ß = 0.12, 95% CI: 0.08, 0.16; women ß = 0.12, 95% CI: 0.09, 0.16) and muscle area (men ß = 0.38, 95% CI: 0.33, 0.43; women ß = 0.33, 95% CI: 0.29, 0.37) were associated with peak torque. Conclusions: These data suggest that muscle attenuation and area are independently associated with RTD and peak torque; and that area and attenuation demonstrate similar contributions to RTD.

Evolution of ectomycorrhizas as a driver of diversification and biogeographic patterns in the model mycorrhizal mushroom genus Laccaria.

A systematic and evolutionary ecology study of the model ectomycorrhizal (ECM) genus Laccaria was performed using herbarium material and field collections from over 30 countries covering its known geographic range. A four-gene (nrITS, 28S, RPB2, EF1α) nucleotide sequence dataset consisting of 232 Laccaria specimens was analyzed phylogenetically. The resulting Global Laccaria dataset was used for molecular dating and estimating diversification rates in the genus. Stable isotope analysis of carbon and nitrogen was used to evaluate the origin of Laccaria's ECM ecology. In all, 116 Laccaria molecular species were identified, resulting in a near 50% increase in its known diversity, including the new species described herein: Laccaria ambigua. Molecular dating indicates that the most recent common ancestor to Laccaria existed in the early Paleocene (56-66 million yr ago), probably in Australasia. At this time, Laccaria split into two lineages: one represented by the new species L. ambigua, and the other reflecting a large shift in diversification that resulted in the remainder of Laccaria. L. ambigua shows a different isotopic profile than all other Laccaria species. Isotopes and diversification results suggest that the evolution of the ECM ecology was a key innovation in the evolution of Laccaria. Diversification shifts associated with Laccaria's dispersal to the northern hemisphere are attributed to adaptations to new ecological niches.