Search

Purpose: The purpose of this study was to compare the biomechanical effect of in-situ repair of posterior lateral meniscal root (PLMR) tear with segmental meniscal loss, with and without meniscofemoral ligament (MFL) imbrication, on anterior cruciate ligament (ACL) graft force and knee joint kinematics., Methods: Ten fresh-frozen cadaveric knee specimens underwent kinematic evaluation in five states: 1) Native, 2) ACLR, 3) Segmental PLMR loss, 4) In-situ PLMR repair, and 5) MFL augmentation. Kinematic evaluation consisted of five tests, each performed at full extension and at 30° of flexion: 1) Anterior drawer, 2) Internal Rotation, 3) External Rotation, 4) Varus, and 5) Valgus. Additionally, a simulated pivot shift test was performed. Knee kinematics and ACL graft force were measured., Results: PLMR tear did not significantly increase ACL graft force in any test. However, PLMR repair significantly reduced ACL graft force compared to the ACLR alone (over constraint -26.6 N, p = 0.001). PLMR tear significantly increased ATT during the pivot shift test (+ 2.7 mm, p = 0.0001), and PLMR repair restored native laxity. MFL augmentation did not improve the mechanics., Conclusions: In-situ PLMR repair eliminated pivot shift laxity through ATT and reduced force on the ACL graft, indicating that this procedure may be ACL graft-protective. MFL augmentation was not shown to have any effect on graft force or knee kinematics and untreated PLMR tears may place an ACL graft at higher risk. This study suggests concomitant repair to minimize additional forces on the ACL graft., (© 2023. The Author(s).)

Whip spiders (Arachnida, Amblypygi), like many other soil arthropods, transfer their spermatozoa indirectly via a stalked spermatophore. While the complex courtship behavior as well as the morphological differences of spermatophores and corresponding female genitalia between taxa have received great attention in the past, comparative research on the internal reproductive system is lacking so far. In this study, the morphology of the male whip spiders of four neoamblypygid taxa has been comparatively studied via computer tomography and subsequent 3D reconstruction. We investigated four species belonging to the Neoamblypygi, that is, the phrynichid species Damon medius (Damoninae), and Euphrynichus bacillifer (Phrynichidae), the phrynid species Phrynus hispaniolae (Phrynidae), and the charontid species Charon grayi (Charontidae). The male reproductive organs consist of paired testes and two pairs of accessory glands, the ventral and lateral glands, which project their ducts anteriorly into the ventrally located unpaired spermatophore producing organ where the respective seminal and secretory reservoirs are located. While this general organization of the male reproductive system is similar among all investigated taxa, there are some notable differences in some structures. The most surprising findings include the complete absence of ventral glands in D. medius, the presence of unique spherical ventral gland reservoirs in C. grayi as well as differences in the organization of the seminal and secretory reservoirs and their connections to the inner genital slit. In addition, the secretory products of both, ventral and lateral glands, are stored in combined secretory reservoirs in E. bacillifer and P. hispaniolae. This study is the first to show that there is some morphological variation in the male reproductive system in Neoamblypygi. These results are the basis for the reconstruction of the Bauplan for the reproductive organs of the whip spiders., (© 2022 Wiley Periodicals LLC.)

Like other arthropods, whip spiders of the arachnid order Amblypygi Thorell, 1883 protect themselves against external environmental influences. In this taxon, in addition to the epicuticle, the outermost layer of the exoskeleton, a cement layer (cerotegument) with superhydrophobic properties is deposited over certain body parts. Due to the high level of interspecific variation, the cerotegument structure and the morphology of its associated gland openings have been suggested to be informative for whip spider systematics. The first comparative study of the cerotegument is presented herein, based on a survey across 4 families, 16 genera, and 62 species of Euamblypygi Weygoldt, 1996, the suborder comprising all extant whip spiders except the rare monotypic family Paracharontidae Weygoldt, 1996. Results confirmed that the morphology of the colloidal particles and their assembly on cement globules differ considerably among taxa, but that the level of variation differs among lineages. Interspecific variation in cerotegument ultrastructure was highest among species of Neoamblypygi Weygoldt, 1996, making it an informative character in this clade. Evolutionary trends and intraspecific variation in the structure of the amblypygid cerotegument are briefly discussed., (© 2022 Wiley Periodicals LLC.)

Whole-genome duplications (WGDs) have occurred multiple times during animal evolution, including in lineages leading to vertebrates, teleosts, horseshoe crabs, and arachnopulmonates. These dramatic events initially produce a wealth of new genetic material, generally followed by extensive gene loss. It appears, however, that developmental genes such as homeobox genes, signaling pathway components and microRNAs are frequently retained as duplicates (so-called ohnologs) following WGD. These not only provide the best evidence for WGD, but an opportunity to study its evolutionary consequences. Although these genes are well studied in the context of vertebrate WGD, similar comparisons across the extant arachnopulmonate orders are patchy. We sequenced embryonic transcriptomes from two spider species and two amblypygid species and surveyed three important gene families, Hox, Wnt, and frizzled, across these and 12 existing transcriptomic and genomic resources for chelicerates. We report extensive retention of putative ohnologs, further supporting the ancestral arachnopulmonate WGD. We also found evidence of consistent evolutionary trajectories in Hox and Wnt gene repertoires across three of the six arachnopulmonate orders, with interorder variation in the retention of specific paralogs. We identified variation between major clades in spiders and are better able to reconstruct the chronology of gene duplications and losses in spiders, amblypygids, and scorpions. These insights shed light on the evolution of the developmental toolkit in arachnopulmonates, highlight the importance of the comparative approach within lineages, and provide substantial new transcriptomic data for future study., (© The Author(s) 2021. Published by Oxford University Press on behalf of Genetics Society of America.)

Whip spiders (Amblypygi) represent an ancient order of tetrapulmonate arachnids with a low diversity. Their cytogenetic data are confined to only a few reports. Here, we analyzed the family Charinidae, a lineage almost at the base of the amblypygids, providing an insight into the ancestral traits and basic trajectories of amblypygid karyotype evolution. We performed Giemsa staining, selected banding techniques, and detected 18S ribosomal DNA and telomeric repeats by fluorescence in situ hybridization in four Charinus and five Sarax species. Both genera exhibit a wide range of diploid chromosome numbers (2 n = 42-76 and 22-74 for Charinus and Sarax , respectively). The 2 n reduction was accompanied by an increase of proportion of biarmed elements. We further revealed a single NOR site (probably an ancestral condition for charinids), the presence of a (TTAGG) n telomeric motif localized mostly at the chromosome ends, and an absence of heteromorphic sex chromosomes. Our data collectively suggest a high pace of karyotype repatterning in amblypygids, with probably a high ancestral 2 n and its subsequent gradual reduction by fusions, and the action of pericentric inversions, similarly to what has been proposed for neoamblypygids. The possible contribution of fissions to charinid karyotype repatterning, however, cannot be fully ruled out.

Pedipalpi Latreille, 1810 is a poorly studied clade of arachnids comprising the whip spiders (Amblypygi Thorell, 1883), short-tailed whip scorpions (Schizomida Petrunkevitch, 1945) and whip scorpions (Thelyphonida Cambridge, 1872). It has recently been shown that whip spiders coat their exoskeleton with a solid cement layer (cerotegument) that forms elaborate microstructures and turns the cuticle into a super-hydrophobic state. The amblypygid cerotegument provides taxonomic information due to its fine structural diversity, but its presence and variation in the sister groups was previously unknown. The present contribution reports the surface structure of the cuticle in species of Palpigradi, Thelyphonida, and Schizomida to determine if these taxa possess a solid epicuticular secretion coat. Scanning electron microscopy revealed that in addition to Amblypygi only species of Thelyphonida possess solid epicuticular secretion layers. Unlike in Amblypygi, in the Thelyphonida this layer does not usually form microstructures and is less rigidly attached to the underlying cuticle. A species of Typopeltis Pocock, 1894, which exhibited globular structures analogous to the amblypygid cerotegument, was an exception. Glandular structures associated with cement secretions in Amblypygi and Thelyphonida were considered homologous due to similar structure. Solid epicuticular secretion coats were absent from Schizomida, which is interpreted as a secondary loss despite the presence of slit-like glandular openings that appear to produce such epicuticular secretions. The micro-whip scorpion order Palpigradi Thorell, 1900 exhibited markedly different cuticular surface structures and lacked solid epicuticular secretions, consistent with the hypothesis that this order is not closely related to Pedipalpi. These results enhance the knowledge of the small, enigmatic orders of Arachnida., (© 2021 Wiley Periodicals LLC.)

The Sox family of transcription factors regulates many processes during metazoan development, including stem cell maintenance and nervous system specification. Characterizing the repertoires and roles of these genes can therefore provide important insights into animal evolution and development. We further characterized the Sox repertoires of several arachnid species with and without an ancestral whole-genome duplication and compared their expression between the spider Parasteatoda tepidariorum and the harvestman Phalangium opilio. We found that most Sox families have been retained as ohnologs after whole-genome duplication and evidence for potential subfunctionalization and/or neofunctionalization events. Our results also suggest that Sox21b-1 likely regulated segmentation ancestrally in arachnids, playing a similar role to the closely related SoxB gene, Dichaete, in insects. We previously showed that Sox21b-1 is required for the simultaneous formation of prosomal segments and sequential addition of opisthosomal segments in P. tepidariorum. We studied the expression and function of Sox21b-1 further in this spider and found that although this gene regulates the generation of both prosomal and opisthosomal segments, it plays different roles in the formation of these tagmata reflecting their contrasting modes of segmentation and deployment of gene regulatory networks with different architectures., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Background: Treatment of tibia diaphyseal fractures with intramedullary nail fixation has proven to be effective. An increasingly popular practice is to coat the nail with bone cement incorporating antibiotics for the purpose of treating and/or preventing infection. To date, the effect of coating on the mechanical performance of the intramedullary nail once implanted is unknown. We hypothesize that cement coating does not change the cross-sectional stiffness of the nail, so that, when fixing tibia diaphyseal fracture with gapping, cement coated intramedullary nail provide stiffness comparable to that of standard conventional uncoated ones., Methods: Tests of 4-point bending were conducted to compare the cross-sectional stiffness of uncoated to coated nails. In addition, mechanical tests of compression and torsion on tibia bone phantoms instrumented with coated and uncoated nails were performed, and the proximal-to-distal bone fragment rotations were compared., Findings: The 4-point bending tests indicated that the cross-sectional stiffness of coated nails was not significantly different from that of the uncoated ones (p-value >0.05). Mechanical tests of compression and torsion corroborated these results by showing no statistical difference in the proximal-to-distal bone rotations attained with uncoated nails when compared to those measured for the coated ones (p-value >0.05)., Interpretation: Cement coating on the nail cannot be relied upon for increased mechanical stiffness of the implant, and should be solely considered as a vehicle for topic delivery of antibiotics., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In the setting of femoroacetabular impingement, the acetabular labrum may be torn or pathologic, and it must be surgically repaired to restore the native suction seal and hip function. However, the current methods of arthroscopic suture passage commonly result in some degree of disruption of the chondrolabral junction, with penetration and shuttling of the repair sutures. Novel instrumentation and surgical techniques have aimed to repair the acetabular labrum with decreased violation of the intrasubstance fibers to provide anatomic eversion/inversion of the labrum to restore the suction seal. In this Technical Note, we describe a method of suture passage through the use of a self-grasping suture-passing device that allows for anatomic labral repair while maintaining the chondrolabral junction as well as minimizing iatrogenic damage the labrum intrasubstance fibers., (© 2020 by the Arthroscopy Association of North America. Published by Elsevier.)

Anesthesia management during hallux valgus surgery trends toward multimodal pain control. Locoregional anesthesia with peripheral nerve blocks and wound instillation increase pain control. Peripheral nerve blocks as first-line analgesia are effective with minimal side effects. Local wound instillation has a variable but positive effect with minimal negative side effects. Nonsteroidal anti-inflammatory drugs in bone-to-bone healing remain controversial; however, they reduce opiate requirements and enhance patient satisfaction. Opiate agonists remain the mainstay for postoperative pain; long-acting formulations minimize pain crises. Multimodal analgesia with locoregional anesthesia facilitate the progress of hallux valgus surgery as an outpatient procedure., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Fungi and arthropods represent some of the most diverse organisms on our planet, yet the ecological relationships between them remain largely unknown. In animals, fungal growth on body surfaces is often hazardous and is known to cause mortality. In contrast, here we report the presence of an apparently non-harmful mycobiome on the cuticle of whip spiders (Arachnida: Amblypygi). The associations are not species-specific and involve a diversity of fungal species, including cosmopolitan and local decomposers as well as entomopathogens. We discuss the ecology of the detected fungal species and hypothesize that the thick epicuticular secretion coat of whip spiders (the cerotegument) promotes fungal growth. It is possible that this relationship is beneficial towards the host if it leads to parasite control or chemical camouflage. Our findings, which are the first from this arthropod lineage, indicate that non-pathogenic interactions between arthropods and fungi may be much more widespread than predicted and call for more studies in this area., (Copyright © 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

A new species of Charinus Simon, 1892 from the Dominican Republic is described. With the addition of Charinus magua sp. nov. from the Monseñor Nouel province, the number of known members of the genus Charinus occurring on the island Hispaniola is increased to three. The frontal process, the trichobothria on leg IV, the number and shape of the articles of leg I and the shape of the tarsomers of legs II-IV are often included in taxonomical descriptions of Charinus species. We present these characters in the detailed description of C. magua sp. nov. and illustrate these for the first time for the two other known Charinus from Hispaniola, Charinus dominicanus and Charinus bahoruco. Furthermore, we present and discuss the cerotegument ultrastructure of all three species.

Background: Nintedanib, an oral tyrosine kinase inhibitor, has been shown to slow down the progression of idiopathic pulmonary fibrosis (IPF) in two randomised placebo-controlled trials by reducing the annual decline in forced vital capacity (FVC). However, real-world experience is limited., Objective: To assess the efficacy and safety of nintedanib in a large cohort of patients treated at a tertiary referral site for interstitial lung diseases., Methods: The records of patients with a confirmed diagnosis of IPF were reviewed. Full medical history, pulmonary function, and adverse events (AEs) were recorded from each clinic visit. Disease progression was defined as a reduction in FVC ≥5% and/or in diffusing capacity of the lung for carbon monoxide ≥15% according to recent publications. Only patients with a treatment duration ≥3 months were included in the efficacy evaluation., Results: A total of 64 patients were treated. Mean ± standard deviation (SD) FVC was 71 ± 21% predicted, and the mean time from diagnosis to initiation of nintedanib treatment was 23.8 months. Nearly half of patients (n = 30, 47%) had received prior pirfenidone treatment. The mean duration of follow-up was 11 months. At 6 months following initiation of nintedanib, 67% of the patients were stable. The mean ± SD change in percent predicted FVC from baseline was 0.2 ± 7.8% at 3 months, -1.3 ± 7.9% at 6 months, and -2.1 ± 9% at 9 months. Diarrhoea was the most common AE experienced by 33% of patients and was generally manageable., Conclusion: The results from this real-world clinical setting support findings from previously conducted clinical trials and show that nintedanib is effective for the management of IPF and is associated with disease stabilisation. Nintedanib is generally well tolerated., (© 2018 The Author(s) Published by S. Karger AG, Basel.)

Treating scaphoid nonunions presents difficulties particularly when there is bone loss, significant humpback deformity or avascular necrosis. We describe a new type of fixation with a volar scaphoid plate that adds to the methods of internal fixation that are available for the treatment of recalcitrant scaphoid nonunions. We will also discuss 'lessons learned' from a cases series. The case series includes 20 consecutive patients treated with volar buttress plating and a pedicled vascularized bone graft from the ipsilateral volar distal radius. There was clinical and radiographic evidence of union in 18 of 20 patients, 13 of which were verified by computed tomographic scan. The range of motion was improved in all patients post-operatively. Four patients with radiographic union experienced intermittent clicking with maximal wrist flexion, believed to be due to the impingement of the plate on the volar aspect of the radioscaphoid articulation and underwent removal at approximately 1 year after the index procedure. Volar scaphoid plating is a useful alternative to headless scaphoid screw fixation in the treatment of unstable scaphoid waist fractures and nonunions., Level of Evidence: IV.

Certain arachnids exhibit complex coatings of their exoskeleton, consisting of globular structures with complex surface features. This, so-called, cerotegument is formed by a multi-component colloidal secretion that self-assembles and cures on the body surface, and leads to high water repellency. Previous ultrastructural studies revealed the involvement of different glandular cells that contribute different components to the secretion mixture, but the overall process of self-assembly into the complex regular structures observed remained highly unclear. Here we study this process from a theoretical point of view, starting from the so-called Tammes-problem. We show that slight changes of simple parameters lead to a variety of morphologies that are highly similar to the ones observed in the species specific cerotegument structures of whip-spiders. These results are not only important for our understanding of the formation of globular hierarchical structures in nature, but also for the fabrication of novel surface coatings by colloidal lithography., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The ability to learn is ubiquitous in animals but highly variable within and between species, populations and individuals. Diet-related circumstances, such as diet quantity and quality can influence both long-term constitutive (genetic; by selection) and short-term operational (non-genetic; by the immediate circumstances) learning performance. Here, we scrutinized the causes of loss of learning ability, following multi-generational feeding on pollen, in a line of the predatory mite Amblyseius swirskii, which was previously well able to learn prey during early life, enhancing foraging later in life. We investigated whether, and, if so, how quickly, a transgenerational diet switch to live prey restores the early learning ability of foraging predatory mites. The first experiment shows that the early learning ability was restored after switching the diet of the pollen-fed predator line to live spider mites for two generations before conducting the behavioral assay. The second experiment reveals that offspring regained their learning ability if the diet of their mothers was switched from pollen to spider mites for 3 or 10 days before offspring production. Both experiments in concert suggest transgenerational, pollen-induced operational loss of learning ability in the predatory mite A. swirskii. Maternally-transmitted nutrient deficiency and/or maternally-induced epigenetic changes are the most plausible explanations for the pollen diet-induced loss of learning ability. Our study represents a key example for maternal diet-induced variation in learning ability.

Here Stygophrynus orientalis sp. nov. is described, a new charontid whip spider from Banggai Island, Indonesia, representing the most eastern record of the genus exceeding the formerly postulated restriction of its distribution western of the Wallace Line. In addition, the third known spermatophore of a Stygophrynus species is presented, which differs remarkably from those previously described from the genus. Finally, the cerotegument structure of the new species is depicted and compared with that of other Charontidae and Charinidae.

The cuticle of arthropods is usually composed of layers of a chitin-protein-microcomposite, a proteinaceous epicuticle and a thin lipid coating. However, in some instances a thick cement layer (cerotegument) covers the cuticle and may produce elaborate microstructures. This has previously been described for millipedes and mites. Here we report the previously unknown presence of a superhydrophobic cerotegument in whip-spiders (Ambypygi) and reveal its variation in ultrastructure and water-repellence between species. We discuss the relevance of found micro-morphological and physical characters for taxonomy and phylogenetics of this group, and the potential biological functions., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Glenoid bone loss can affect the outcome and treatment for posttraumatic recurrent anterior glenohumeral instability. Clinical presentation in the adolescent age group with shoulder instability and glenoid bone loss is largely unknown. On the basis of this information, we believe there will be a high incidence of glenoid bone loss in adolescent patients with recurrent glenohumeral instability. We hypothesize that high-impact injuries, sports injuries, and reductions requiring sedation will be factors associated with glenoid bone loss., Methods: We performed a retrospective cross-sectional cohort study reviewing consecutive adolescent patients (n=114) with recurrent traumatic glenohumeral instability between 2004 and 2012. Chart analysis included demographic, presenting, and radiographic data. Glenoid bone loss was interpreted from plain radiographs, computed tomography (2D and/or 3D), magnetic resonance imaging, and/or arthroscopy. We compared possible risk factors between subjects with and without glenoid bone defects using the χ test or 2 sample t tests., Results: Glenoid bone loss was seen in 55 patients (48.2%) with 15 of these patients (27%) having critical bone loss. Forty-five percent of appreciated glenoid bone loss was not visualized on plain radiographs. The average age was 15.1 years (range, 6.5 to 18.1) with male to female ratio 3.7:1. Male sex, older age, and taller stature were all statistically associated with glenoid bone loss (P=0.02, 0.01, and 0.02, respectively). Primary dislocations that occurred during sports were more likely to have glenoid bone loss (55.9% vs. 78.2%, P=0.01). The presence of an apprehension sign on physical examination was positively correlated with bone loss (P=0.008)., Conclusions: The presence of glenoid bone loss in primary traumatic glenohumeral instability in the adolescent population is high, however, not as high as previously reported. Factors associated with glenoid bone loss include male sex, older age, taller stature, sports injuries, and the presence of apprehension on physical examination., Level of Evidence: This study establishes patients who may be at high risk for glenoid bone loss based on mechanism of injury and physical examination findings. This prognostic study is a level II retrospective study.

Background: Among both plants and arthropods, super-hydrophobic surfaces have evolved that enable self-cleaning, locomotion on water surfaces, or plastron respiration. Super-hydrophobicity is achieved by a combination of non-polar substances and complex micro- and nano-structures, usually acquired by growing processes or the deposition of powder-like materials., Results: Here we report on a multi-phasic secretion in whip spiders (Arachnida, Amblypygi), which externally forms durable, hierarchical microstructures on the basically smooth cuticle. The solidified secretion crust makes the previously highly wettable cuticle super-hydrophobic. We describe the ultrastructure of secretory cells, and the maturation and secretion of the different products involved., Conclusion: Whip spiders represent intriguing objects of study for revealing the mechanisms of the formation of complex microstructures in non-living systems. Understanding the physical and chemical processes involved may, further, be of interest for bio-inspired design of functional surface coatings.

Learning is widely documented across animal taxa but studies stringently scrutinizing the causes of constitutive or operational variation of learning among populations and individuals are scarce. The ability to learn is genetically determined and subject to constitutive variation while the performance in learning depends on the immediate circumstances and is subject to operational variation. We assessed variation in learning ability and performance of plant-inhabiting predatory mites, Amblyseius swirskii, caused by population origin, rearing diet, and type of experience. Using an early learning foraging paradigm, we determined that homogeneous single prey environments did not select for reduced learning ability, as compared to natural prey-diverse environments, whereas a multi-generational pollen diet resulted in loss of learning, as compared to a diet of live prey. Associative learning produced stronger effects than non-associative learning but both types of experience produced persistent memory. Our study represents a key example of environmentally caused variation in learning ability and performance., Competing Interests: The authors have declared that no competing interests exist.

All records of the two amblypygid species occurring in the Western Palaearctic are mapped and both species (Charinus ioanniticus and Musicodamon atlanteus) are discussed. Charinus ioanniticus is known from the Eastern Mediterranean (Greece, Turkey, Israel and Egypt) from 10 localities and Musicodamon atlanteus is known from the Maghreb (Morocco, Algeria) from three localities. All records are mapped.