Bony Plates Research Articles

Scale pattern of five species of Zeiformes (Teleostei)

AbstractThe order Zeiformes comprises a small order of predominantly deep‐sea fishes. However, little information is available on their morphology, such as squamation. Therefore, in the present study, we analysed and described the squamation pattern and scale morphology of five species of Zeiformes occurring on the Brazilian coast: Allocyttus verrucosus, Grammicolepis brachiusculus, Xenolepidichthys dalgleishi, Zenion hololepis and Zenopsis conchifer. Our analysis revealed greater morphological diversity than previously reported for this order. All species, except the scaleless Zenopsis conchifer, presented cycloid scales of spinoid subtype. Grammicolepis and Zenion presented exclusively scales of the spinoid subtype, whereas both Allocyttus and Xenolepidichthys also displayed true cycloid subtype. A. verrucosus is characterised by two distinct groups of scales of different sizes that form scale clusters. G. brachiusculus and X. dalgleishi presented a unique vertically elongated scale covering most of the body. Small bony plates were observed at the dorsal‐ and anal‐fin bases of G. brachiusculus, X. dalgleishi and Z. hololepis. The variation observed is putatively useful for the systematics of the order.

Immediate single-tooth implant placement in bony defect sites: A 10-year randomized controlled trial.

It is unclear whether an intact buccal bony plate is a prerequisite for immediate implant placement in postextraction sockets. The aim of this 10-year randomized controlled trial was to compare peri-implant soft and hard tissue parameters, esthetic ratings of, and patient-reported satisfaction with immediate implant placement in postextraction sockets with buccal bony defects ≥5mm in the esthetic zone versus delayed implant placement after alveolar ridge preservation. Patients presenting a failing tooth in the esthetic region and a buccal bony defect ≥5mm after an extraction were randomly assigned to immediate (Immediate Group, n=20) or delayed (Delayed Group, n=20) implant placement. The second-stage surgery and provisional restoration placement occurred 3months after implant placement in both groups, followed by definitive restorations 3months thereafter. During a 10-year follow-up period, marginal bone levels (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded. The mean marginal bone level change was -0.71±0.59mm and -0.36±0.39mm in the Immediate Group and the Delayed Group after 10years (p=0.063), respectively. The secondary outcomes were not significantly different between both groups. Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in postextraction sockets with buccal bony defects ≥5mm, were not statistically different to those following delayed implant placement after ridge preservation in the esthetic zone. Immediate implant placement in case of a failing tooth is a favorable treatment option for patients because it considerably shortens treatment time and the number of surgical treatments. The question is if an intact buccal bone wall is necessary for immediate implant placement. A 10-year study was performed in which 20 patients with a failing tooth in the frontal region of the upper jaw were treated with immediate implant placement and were compared with 20 patients in whom a more conventional treatment strategy was followed in which the failing tooth was first removed and the bone gap restored and the implant placed in a second step. After a 10-year follow-up period, it appeared that the bone around the implant was very stable, gums were healthy, and patients were very satisfied with the result. There was no difference between the two treatment procedures. Such results mean that professionals can discuss the procedure with the patient and apply the individual's preference.

Extraction and characterization of collagen from the skin of Pterygoplichthys spp. (armored catfish) from Chiapas

Because of its biocompatibility and safety, collagen is a valuable biomaterial that is used in various industries. While traditionally sourced from terrestrial mammals, collagen extracted from fish waste is a promising alternative due to its chemical properties and low cost. In Mexico, Pterygoplichthys spp. is considered an invasive species, inedible, and of limited commercial importance due to the low muscle content and skin covered with rigid bony plates. This study aimed to extract and characterize collagen from the skin of Pterygoplichthys spp. obtained from two communities in Chiapas, Mexico. Our results show that the extracted collagen is type 1, with a yield of 43.0% (dry weight). Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed the presence of two alpha chains (α1, α2) and a beta and gamma component, consistent with type 1 collagen. Liquid chromatography coupled to mass spectrophotometry analysis identified peptide sequences homologous to those reported in other species. This study highlights the potential of Pterygoplichthys spp. skin collagen as a viable alternative to mammalian collagen. The efficiency of the extraction process and the identification of peptides resembling those of the other species underscore the feasibility of utilizing collagen from the skin of Pterygoplichthys spp. in industrial applications, offering a sustainable solution to environmental and economic challenges. Practical Application: Collagen extracted from the skin of Pterygoplichthys spp., an invasive fish species, can serve as a sustainable alternative to mammalian collagen, offering a cost-effective biomaterial with properties suitable for various industrial applications.

Choanal Atresia: Clinical Features and Factors Affecting Its Surgical Outcomes

Introduction: One of a rare congenital anomaly seen in the development of nose is choanal atresia, whose occurrence is 1 in 5000-8000 live births. This study highlights our experiences in the management of choanal atresia. Materials and methods: It is a retrospective study, which includes the systematic analysis of case files of patients who underwent surgical treatment for choanal atresia from the year 2015 to 2022. Results: Total of 11 cases (15 operated sides) which has 9 female (53%) and 8 male (47%). Majority of them were bony atretic plate (10) followed by mixed variety (5) and none purely membranous. Age at 1st surgery in bilateral cases ranged from 6th day of life to 18th day of life. For unilateral cases the age at 1st surgery ranged from 26th day of life to as late as 10 years old. Conclusion: Management of choanal atresia involves multi-disciplinary approach and preventing restenosis is a challenge. Factors effecting the outcome of surgery are age and weight of the child, as bigger the child in size, wider the choanal arches can be opened with less post-operative scarring and restenosis. Usage of nasopharyngeal airway as a stent in primary repair during early post-operative period is essential to stabilize the nasal airway.

Anatomical variations of Koerner's septum: a computed tomography-based, single-centered study.

Koerner's septum (KS) is a bony plate located at the junction of the petrous and squamous parts of the temporal bone. The reported prevalence of KS varied between studies. KS variations are associated with various pathologies and pose difficulties during surgeries. The study aims to determine the KS frequency in Omani patients and analyze its association with sex and side. The present study investigated the KS topography in 344 computed tomography (CT) scans of normal temporal bones of adult Omani patients at Sultan Qaboos University Hospital. The presence of KS and its parts (complete or incomplete), as well as its thickness at three anatomical landmarks were recorded. Additionally, sex and laterality differences in KS parameters were analyzed using a Chi-square test. The overall frequency of KS among Omani subjects was 39.5%. The complete KS was observed only in 14% of cases. The thickness of KS was 0.78 ± 0.21 mm, 0.93 ± 0.28 mm and 0.78 ± 0.21 mm at the head of the malleus (HM), the superior semicircular canal (SSC) and the tympanic sinus (TS), respectively (p<0.01). KS was present most constantly at the level of HM (64.7%), followed by SSC (57.4%), and less constantly at the level of TS (49.3%). KS frequency was similar in both males than females (41.9% vs 37.3%), with statistically insignificant difference (p = 0.38). No side differences were observed concerning KS frequency (p = 0.955). The KS frequency in Omani subjects within the range of previously reported studies. It is incomplete in most of the cases and constantly present at the level of HM. Its thickness is more at the level of SSC.

Functional reliability of means of fixation for complex pelvic fractures. Part 1: Materials and methods

Due to the military aggression of the Russian Federation against Ukraine, a large number of soldiers and civilians were wounded and injured. Along with fractures of the long bones of the limbs, skull injuries, limb amputations, the number of injuries in the pelvic area with fractures of the pelvic bones as a result of being hit by high-velocity projectiles (shrapnel, bullets) has increased.This work is devoted to the preparation and research of the characteristics of stiffness and reliability of fixation of complex fractures of the pelvic bones in the area of the sacroiliac joint and the upper and lower branches of the pubic bone, which may occur as a result of injury by high-velocity projectiles that injure.The sacroiliac area was fixed with two cancellous screws with a parallel arrangement at the intersection of the horizontal and vertical planes (a typical technique for stabilizing the posterior parts of the pelvis). The anterior parts of the pelvic bones were stabilized with rod devices of external fixation with a typical location of the rods in the upper anterior iliac spine. The upper branch of the pubic bone was synthesized with a bony reconstructive plate with a typical location.

Development of Skin and Dermal Bone of the Shell in &lt;i&gt;Pelodiscus maackii&lt;/i&gt; (Testudines: Trionychidae)

The article is devoted to the study of the ontogenetic development of the skin and the structure of the skin-bone shell of the trionychid turtle Pelodiscus maackii (Brandt, 1858). The process of formation of the epidermis and dermis, as well as their derivatives (epidermal scales and dermal ossifications), is described. The development of epidermal scales in Pelodiscus maackii has been shown to be similar to the development of asymmetric scales in other reptiles. Five stages of formation of the definitive structure of the dermal bones have been identified. Structural differences between the internal and external parts of the bony plates (rod-shaped elements and bony callosities) are due to the previous stratification of the dermis into histologically distinct strata: hypodermal, fibrous and papillary. In particular, the fibrous stratum, consisting of several layers of orthogonally oriented collagen bundles, is a precursor to the plywood-like structure of the trionychid bony plates. The growth of bone tissue around the vascular network in the papillary layer is the reason for the formation of surface ornamentation of the trionychid callosities. Some questions of the evolutionary significance of the unique features of the trionychid shell are discussed.

Craniosynostosis-associated variants in the IL-11R complex: new insights and questions.

Skull growth involves the expansion of both the flat calvarial bones of the skull and the fibrous marginal zones, termed sutures, between them. This process depends on co-ordinated proliferation of mesenchymal-derived progenitor cells within the sutures, and their differentiation to osteoblasts which produce the bone matrix required to expand the size of the bony plates. Defects lead to premature closure of these sutures, termed craniosynostosis, resulting in heterogeneous head shape differences due to restricted growth of one or more sutures. The impact on the individual depends on how many and which sutures are affected and the severity of the effect. Several genetic loci are responsible, including a wide range of variants in the gene for the interleukin 11 receptor (IL11RA, OMIM#600939). Recent work from Kespohl and colleagues provides new insights into how some of these variants influence IL-11R function; we discuss their influences on IL-11R structure and IL-11 function as a stimulus of osteoblast differentiation.

Analysis of the anatomical relationship between the roots of three lower molars with the lingual bone plate and the mandibular canal using cone beam computed tomography

Odontectomy of the inferior wisdom teeth is considered to be one of the most frequently performed dental surgeries. It is certain that in order to prevent possible complications, the oral surgeon must have extensive knowledge regarding the anatomy of the region, possible intra– and postoperative risks, as well as treatment methods that would minimize the occurrence of complications. Of course, a key aspect in choosing the treatment technique and method is represented by the paraclinical investigations, and currently CBCT is considered to be the “golden” standard in visualizing the relationship of the third inferior molars to the neighboring anatomical structures, a fact that significantly contributes to the optimization the provision of dental surgical assistance. The purpose of this study was to reveal the role of the CBCT paraclinical radiological examination in the pre–surgical evaluation of the anatomical relationships of the roots of the lower third molars with the neighboring anatomical elements for the prophylaxis of postextractional complications. Material and methods. The prospective clinical study was based on the visualization of tomographic sections of 116 CBCTs, with a total of 160 inferior wisdom teeth, analyzing various study variables such as the relationship of the inferior wisdom teeth roots to the mandibular canal, to the lingual bony plate, root morphology, etc., with their subsequent statistical analysis. Results and discussion. The extraction of the lower wisdom teeth can be associated with the occurrence of various complications such as the association of postoperative infection, dislodging the teeth into the neighboring spaces, nerve damage. It is important to use preoperatively both the predictability scale of the difficulty of extraction of inferior third molar and the three–dimensional paraclinical investigations in order to plan a treatment plan involving low risks of intra– and postoperative complications. Conclusions. The use of three–dimensional paraclinical investigations such as CBCT are absolutely necessary both for visualizing the relationship between anatomical structures and for planning complex clinical cases.

Histological and ultrastructural characterization of the dorso-ventral skin of the juvenile and the adult starry puffer fish (Arothron stellatus, Anonymous 1798)

BackgroundThe starry puffer fish (Arothron stellatus, Anonymous, 1798) is a poisonous tetradontidae fish inhabiting the Red sea. The skin constitutes an important defense against any external effects. The study aims to characterize the dorso-ventral skin of the juvenile and the adult starry puffer fish using light and scanning electron microscopies. Twenty specimens of juvenile and adult fresh fishes were used.ResultsThe scanning electron microarchitecture of the skin of the juvenile and adult fish showed delicate irregular-shaped protrusions, and well-defined bricks-like elevations on the dorsal side and interrupted folds as well as irregular-shaped protrusions on the ventral side. In adult fish, the patterned microridges of the superficial and deep epithelial cells (keratinocytes) were larger and well-defined in the dorsal skin than in the ventral side, the contrary was seen in the juvenile fish. The microridges were arranged in a fingerprint or honeycomb patterns. The openings of the mucous cells were more numerous in the dorsal skin in both age stages but more noticeable in adult. Furthermore, the sensory cells were more dominant in the juveniles than the adults. The odontic spines were only seen in adult. Histologically, few taste buds were observed in the epidermis of the dorsal skin surface of the adult fish. Both mucous and club cells were embedded in the epidermis of the juvenile and adult fish with different shapes and sizes. Melanophores were observed at the dorsal skin of both juvenile and adult fishes while fewer numbers were noticed at the ventral surfaces. Several dermal bony plates with different shapes and sizes were demonstrated in the skin of both adult and juvenile fishes.ConclusionThe structural variations of skin of the juvenile and adult fishes may reflect the various environmental difficulties that they confront.

Inferring the lifestyles of extinct Crocodyliformes using osteoderm ornamentation.

Osteoderms are bony plates formed within the dermis of diverse vertebrate groups. They are present in all crocodylomorphs but Metriorhynchidae. Most of them show typical bone ornamentation consisting of pits and ridges on their outer surface. The most widely discussed functional hypothesis suggests that the ornamentation of osteoderms influences heat exchange with the environment through the adjacent vascular network, facilitating the absorption of solar radiation. This process allows semiaquatic crocodiles to compensate for heat loss resulting from the high thermal conductivity of surrounding water. In order to test this assertion, we conducted a phylogenetic logistic regression analysis to evaluate the relationship between osteoderm relative area of pits (RAP) and lifestyle (terrestrial versus aquatic) in a sample of crocodyliforms. Our results revealed that lifestyle is significantly explained by RAP: the lower the degree of ornamentation (RAP), the higher the probability of a terrestrial lifestyle. We used this model to infer the lifestyle of two extinct taxa, Peirosaurus torminni and Microsuchus schilleri. We concluded that terrestrial notosuchians may have lost osteoderm ornamentation due to the lower thermal conductivity of air and reduced heat loss in a terrestrial environment compared to what happens in water. Among these notosuchians, we hypothesize that large terrestrial baurusuchids maintained a stable body temperature due to thermal inertia, whereas small notosuchians took advantage of the early morning sun exposure to warm up and stayed in terrestrial burrows during periods of intense solar radiation. Finally, unlike the almost motionless behavior of freshwater crocodiles, fully marine Metriorhynchidae probably lost osteoderms because they constantly swim, generating heat by muscular contraction, so osteoderms with a thermoregulatory function for heat absorption were no longer positively selected.

The first full body diffusible iodine-based contrast-enhanced computed tomography dataset and teaching materials for a member of the Testudines.

Diffusible iodine-based contrast-enhanced Computed Tomography (diceCT) is now a widely used technique for imaging metazoan soft anatomy. Turtles present a particular challenge for anatomists; gross dissection is inherently destructive and irreversible, whereas their near complete shell of bony plates, covered with keratinous scutes, presents a barrier for iodine diffusion and significantly increases contrast-enhanced CT preparation time. Consequently, a complete dataset visualizing the internal soft anatomy of turtles at high resolution and in three dimensions has not yet been successfully achieved. Here we outline a novel method that augments traditional diceCT preparation with an iodine injection technique to acquire the first full body contrast-enhanced dataset for the Testudines. We show this approach to be an effective method of staining the soft tissues inside the shell. The resulting datasets were processed to produce anatomical 3D models that can be used in teaching and research. As diceCT becomes a widely employed method for nondestructively documenting the internal soft anatomy of alcohol preserved museum specimens, we hope that methods applicable to the more challenging of these, such as turtles, will contribute toward the growing stock of digital anatomy in online repositories.

The Flexible Armor of Chinese Sturgeon: Potential Contribution of Fish Skin on Fracture Toughness and Flexural Response.

Fish skin is a biological material with high flexibility and compliance and can provide good mechanical protection against sharp punctures. This unusual structural function makes fish skin a potential biomimetic design model for flexible, protective, and locomotory systems. In this work, tensile fracture tests, bending tests, and calculation analyses were conducted to study the toughening mechanism of sturgeon fish skin, the bending response of the whole Chinese sturgeon, and the effect of bony plates on the flexural stiffness of the fish body. Morphological observations showed some placoid scales with drag-reduction functions on the skin surface of the Chinese sturgeon. The mechanical tests revealed that the sturgeon fish skin displayed good fracture toughness. Moreover, flexural stiffness decreased gradually from the anterior region to the posterior region of the fish body, which means that the posterior region (near the tail) had higher flexibility. Under large bending deformation, the bony plates had a specific inhibition effect on the bending deformation of the fish body, especially in the posterior region of the fish body. Furthermore, the test results of the dermis-cut samples showed that the sturgeon fish skin had a significant impact on flexural stiffness, and the fish skin could act as an external tendon to promote effective swimming motion.

The effectiveness of resistance to torsional loads of various options for osteosynthesis of bone fragments of the tibia for fractures in the upper third of the diaphysis (mathematical modeling)

The treatment of patients with tibial fractures and overweight has certain peculiarities due to the increased load on the osteosynthesis device. Objective. To compare the stress-strain state of models of the lower leg with a fracture of the tibia in the upper third of the diaphysis under the influence of torsional load under different options of osteosynthesis depending on the patient's weight. Methods. Using the finite element method, a fracture in the upper third of the tibia and three types of osteosynthesis were modeled: using an external fixation device (EFD), a bone plate, and an intramedullary rod. A torque of 7 Nm and 12 Nm was applied to the tibial plateau. The results. The highest indicators of the stress level in the fracture zone (6.3‒10.8 MPa) and on the metal structure (251.0‒430.2 MPa) were determined in the model with a bony plate. In the model with osteosynthesis with the help of EFD, a fairly low stress level (0.2‒0.3 MPa) was established in the fracture zone, but a high one in the proximal part of the tibia (6.7‒11.5 MPa). The lowest values of stresses in the fracture zone (0.1‒0.2 MPa) and the proximal fragment of the tibia (0.6‒1.0 MPa) were determined under the conditions of reproduction of osteosynthesis using an intramedullary rod, but in the distal part of the tibia the stresses remained quite high — 11.1‒19.0 MPa. Conclusions. The values of stresses in the fracture zone in the models with EFD and intramedullary rod were significantly lower than the values of the intact bone, with the periosteal plate - only at a load of 7 Nm. In the distal fragment of the tibia, the highest stress level was determined in the model with osteosynthesis with an intramedullary rod, in the proximal one — with EFD. Among the metal structures, the greatest stresses were found in the periosteal plate and around the fixing screws and rods under the conditions of its use. The function of the dependence of the amount of stress on the weight of the patient in the elements of the model turned out to be linear and directly proportional.

Orphan gene expressed in flame cone cells uniquely found in seahorse epithelium.

The seahorse is one of the most unique teleost fishes in its morphology. The body is surrounded by bony plates and spines, and the male fish possess a brooding organ, called the brood pouch, on their tail. The surfaces of the brood pouch and the spines are surrounded by characteristic so-called flame cone cells. Based on our histological observations, flame cone cells are present in the seahorse Hippocampus abdominalis, but not in the barbed pipefish Urocampus nanus or the seaweed pipefish Syngnathus schlegeli, both of which belong to the same family as the seahorse. In the flame cone cells, we observed expression of an "orphan gene" lacking homologs in other lineages. This gene, which we named the proline-glycine rich (pgrich) gene, codes for an amino acid sequence composed of repetitive units. In situ hybridization and immunohistochemical analyses detected pgrich-positive signals from the flame cone cells. Based on a survey of the genome sequences of 15 teleost species, the pgrich gene is only found from some species of Syngnathiformes (namely, the genera Syngnathus and Hippocampus). The amino acid sequence of the seahorse PGrich is somewhat similar to the sequence deduced from the antisense strand of elastin. Furthermore, there are many transposable elements around the pgrich gene. These results suggest that the pgrich gene may have originated from the elastin gene with the involvement of transposable elements and obtained its novel function in the flame cone cells during the evolution of the seahorse.

Osteoderms in a mammal the spiny mouse Acomys and the independent evolution of dermal armor

Osteoderms are bony plates found in the skin of vertebrates, mostly commonly in reptiles where they have evolved independently multiple times, suggesting the presence of a gene regulatory network that is readily activated and inactivated. They are absent in birds and mammals except for the armadillo. However, we have discovered that in one subfamily of rodents, the Deomyinae, there are osteoderms in the skin of their tails. Osteoderm development begins in the proximal tail skin and is complete 6weeks after birth. RNA sequencing has identified the gene networks involved in their differentiation. There is a widespread down-regulation of keratin genes and an up-regulation of osteoblast genes and a finely balanced expression of signaling pathways as the osteoderms differentiate. Future comparisons with reptilian osteoderms may allow us to understand how these structures have evolved and why they are so rare in mammals.

Clinical and radiographic evaluation of transalveolar two-step osteotome-mediated sinus floor elevation versus sinus augmentation with displacement of the palatal wall in lateral direction coupled to alveolar ridge split technique: A 3-year retrospective study

IntroductionThe present study aimed to examine the middle-term effects of transcrestal double-sinus elevation (TSFE) versus alveolar/palatal split expansion technique (APS) and simultaneous implant placement in the augmented sinus. Null hypothesis: there were no differences between groups. Material & methodsMagnetoelectric device was used for bone augmentation and expansion techniques in long-standing edentulous patients with a deficiency in vertical height in the posterior maxilla (3mm to 4mm residual bone height): TSFE group, or two-stage process with a first transcrestal sinus floor augmentation and a second sinus floor elevation with immediate implant placement; APS group, or “dual split and dislocation” of the two cortical bony plates towards the sinus and palatal side. Volumetric and linear analyses were performed on the superimposed preoperative and postoperative 3-year computed tomography scans. The level of significance was set at 0.05. ResultsThirty patients were selected for the present analysis. For both groups significant differences were found in the volume outcomes between baseline and 3-year follow-up, showing a gain of about +0.28±0.06cm3 for the TSFE group, and +0.43±0.12cm3 for the APS group, with p-values < 0.0001. However, an effective increase of the volume of the alveolar crest was registered just in the APS group (+0.22±0.09cm3).A significant increase in bone width was found in the APS group (+1.45±0.56mm with p-value < 0.0001); on the contrary, a slight width reduction of the alveolar crest was observed in the TSFE group (-0.63±0.21mm). DiscussionTSFE procedure seemed to not affect the shape of the alveolar crest. APS procedures led to a higher increase of the volume available for dental implant placement and could be used in horizontal bone defects too.

Cover Image

Fluorescence photo of a juvenile seahorse (Hippocampus erectus) one day post-birth with Alizarin Red staining indicating mineralization/ossification. At this stage, the characteristic joined bony plates are already forming and once fully developed, combine into a both rigid and flexible body armor and provide stability to the pectoral fin apparatus, amongst others. From: A comparative analysis of the ontogeny of syngnathids (pipefishes and seahorses) reveals how heterochrony contributed to their diversification; Ralf F. Schneider, Joost M. Woltering, Dominique Adriaens, Olivia Roth; Developmental Dynamics. 2023;252(5); 553–588.

The skin mucosal barrier of lumpfish (Cyclopterus lumpus L.) is weakened by exposure to potential aquaculture production-related stressors.

Various cleaner fish species, such as the lumpfish (Cyclopterus lumpus L.), are used in the sea cage production of Atlantic salmon (Salmo salar L.) as a control measure against the ectoparasitic salmon louse (Lepeophtheirus salmonis). Nonetheless, during severe lice infestation, alternative treatments are required to control parasitic burden. The aim of this study was to gain insight into how lumpfish skin responds to different chemicals used to treat parasites. The authors collected skin from lumpfish from both research facilities (tank-reared fish) and commercial production (cage-reared fish) and used operational welfare indicators, in vitro models, histology and transcriptomics to study how the skin responded to two anti-parasitic oxidative chemicals, hydrogen peroxide (H2 O2 ) and peracetic acid. Lumpfish sampled from the farm were classified as clinically healthy or weak based on their morbidity status, and fish from each category were used to gain insight into how the therapeutics affect the skin barrier. Differences between healthy and weakened (moribund) fish, and between treated fish from each of the two groups, were observed. Histological examination showed an overall reduced skin quality in fish characterized as moribund, including different grades of exposed bony plates. In vitro oxidant-treated lumpfish skin had reduced the migration capacity of keratocytes, a weakened epidermal barrier, and altered gene transcription, changes that are known predisposing factors to secondary infections. Skin from non-treated, healthy fish sampled from commercial farms exhibited similar features and attributes to oxidant-exposed tank-reared fish from a research facility, suggesting that apparently healthy cage-held lumpfish exhibited stress responses in the epidermal barrier. The results of the study outline the risks and consequences lumpfish can face if accidentally subjected to potential anti-parasitic oxidant treatments aimed at Atlantic salmon. It also strengthens the evidence behind the requirement that lumpfish should be removed from the cages before being potentially exposed to this type of treatment and outlines the potential risks of differing husbandry practices upon lumpfish health, welfare and resilience.

Anatomical variation of the sacroiliac joints: an MRI study with synthetic CT images

BackgroundSynthetic computed tomography (sCT) images are magnetic resonance imaging (MRI)-based images, generated using artificial intelligence. This study aimed to determine the prevalence of anatomical variants of sacroiliac joints (SIJ) on sCT images and the correlation with age, sex and body weight.MethodsMRI of the SIJ including sCT images of 215 patients clinically suspected for sacroiliitis were retrospectively analyzed. The presence of anatomical variants of the SIJ was assessed. Age, sex and body mass index at the time of the MRI were recorded.ResultsSIJ variants were found in 82.8% (356/430) of the evaluated joints. The most frequent variants were iliosacral complex (27.7%), bipartite iliac bony plate (27.2%) and crescent iliac bony plate (27%). One new variant was identified, consisting of an accessory facet of the SIJ on the superior side. Overall, SIJ variants were slightly more frequent in women (85.8% vs. 77.8%), but iliosacral complex was significantly more frequent in men. Isolated synostosis was more prevalent with advancing age, in contrast to semicircular defect and unfused ossification center. The occurrence of iliosacral complex was associated with higher BMI, while crescent iliac bony plate occurred more in patients with lower BMI.ConclusionOver 80% of patients in this study, who were all suspected of sacroiliitis, had at least one SIJ variant. These variants may actually represent subtypes of the normal SIJ. sCT enables detection of very small or subtle findings including SIJ variants.