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Royal Society Open Science Apr 2017All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I...
All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I demonstrate that the Late Triassic turtles, which represent successive stages of the shell evolution, indicate that the shift of the boundary between the cervical and dorsal sections of the vertebral column occurred over the course of several million years after the formation of complete carapace. The more generalized reptilian formula of at most seven cervicals and at least 11 dorsals is thus plesiomorphic for Testudinata. The morphological modifications associated with an anterior homeotic change of the first dorsal vertebra towards the last cervical vertebra in the Triassic turtles are partially recapitulated by the reduction of the first dorsal vertebra in crown-group Testudines, and they resemble the morphologies observed under laboratory conditions resulting from the experimental changes of gene expression patterns. This homeotic shift hypothesis is supported by the, unique to turtles, restriction of expression domains, somitic precursors of scapula, and brachial plexus branches to the cervical region, by the number of the marginal scute-forming placodes, which was larger in the Triassic than in modern turtles, and by phylogenetic analyses.
PubMed: 28484613
DOI: 10.1098/rsos.160933 -
European Journal of Trauma and... Dec 2022Complex intraarticular distal radius fractures are common, and treatment with open reduction and internal fixation (ORIF) can be done through either the palmar or dorsal...
INTRODUCTION
Complex intraarticular distal radius fractures are common, and treatment with open reduction and internal fixation (ORIF) can be done through either the palmar or dorsal approach. There is scant evidence, however, indicating which approach is more suitable. We compared clinical and radiological outcomes of patients with AO 2R3 C3 fractures surgically treated with one of these approaches.
MATERIALS AND METHODS
From January 2015 to November 2018, 72 surgically treated patients with AO 2R3 C3 fractures were radiologically (12 months) and clinically (mean 26 months) evaluated. Forty-one patients underwent ORIF using the palmar approach (Group 1), and the dorsal approach was used in 31 patients (Group 2). Radiological parameters were measured using the AO scoring system immediately following surgery and 12 months later. Clinical assessments included the range of motion, PRWE and DASH scores.
RESULTS
At the immediate postoperative assessment, the median AO score was 5.5 (IQR 2-9.5, range 0-30.5) for Group 1 and 8 (IQR 5-15, range 0-27) for Group 2, and 12-month follow-up results were 4.5 (IQR 1.5-10, range 0-41) and 6.5 (IQR 5-11, range 0-29.5), respectively. Group 1 had more favorable results for the flexion, extension, radial abduction, PRWE and DASH parameters. The plate removal and reoperation rates were higher in Group 2.
DISCUSSION
When treating complex intraarticular distal radius fractures, we found the palmar approach was more advantageous for this fracture pattern. Nevertheless, a dorsal approach may still be suitable for intraarticular comminuted distal radius fractures with dorsally displaced joint fragments.
Topics: Humans; Radius Fractures; Retrospective Studies; Fracture Fixation, Internal; Bone Plates; Fractures, Comminuted; Range of Motion, Articular; Treatment Outcome
PubMed: 32415367
DOI: 10.1007/s00068-020-01389-y -
Journal of the European Academy of... Oct 2015The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the...
BACKGROUND
The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the great toe.
MATERIAL AND METHODS
Fifty fresh-frozen human cadaver great toes with no evidence of trauma (average age, 62.5 years; 29 males and 21 females) were used for this study. Under 25X magnification, the proximal limit of the nail matrix and the terminal bony insertion of the extensor hallucis longus tendons were identified. The distance from the terminal tendon insertion to the nail matrix was ascertained using precision calipers, an optical microscope, and autocad(®) software for windows. Twenty-five great toes were placed in a neutral formalin solution and further analysed by histological longitudinal-sections. The specimens were stained with haematoxylin and eosin and examined microscopically to determine the presence of the extensor hallucis longus tendon along the dorsal aspect of the distal phalanx of each great toe.
RESULTS
The main result we found in great toes was that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx in all, 100%, specimens. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of the distal phalanx as is the case for fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone.
CONCLUSIONS
We have found that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of distal phalanx as is the case in fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Our anatomic study demonstrates that the proximal limit of the matrix and nail bed of the human great toe are dorsal and overlapping the terminal extensor hallucis longus tendon until its distal bony insertion in all specimens.
Topics: Aged; Aged, 80 and over; Cadaver; Female; Hallux; Humans; Male; Middle Aged; Nails; Tendons; Toe Phalanges
PubMed: 25807869
DOI: 10.1111/jdv.13108 -
Acta Neurologica Belgica Jun 2024Medial medullary infarction (MMI) is a rare type of posterior circulation stroke. We aim to examine the clinical and radiological features, etiology, and prognosis of...
BACKGROUND AND AIM
Medial medullary infarction (MMI) is a rare type of posterior circulation stroke. We aim to examine the clinical and radiological features, etiology, and prognosis of patients with MMI.
METHOD
MMI patients registered consecutively in the stroke databank of the Istanbul Medical Faculty between January 1999 and April 2022 were included in the study. Medullary lesions were rostrocaudally classified as rostral, middle, and caudal, and ventrodorsally as ventral, middle, and dorsal. The etiological classification was performed, and functional outcome was assessed based on the modified Rankin Scale (mRS). Overall survival was estimated using the Kaplan-Meier technique.
RESULTS
We examined 48 cases of MMI including 9 with bilateral MMI. There were 34 men (70%), and mean age was 62.9 (± 12.8) years. The median NIHSS score was 7 (IQR; 4.5-10.5). The most common symptom was motor dysfunction. The medullary lesions were located caudally in 4 patients, rostrally in 30, rostromedially in 10, and rostro-medio-caudally in 2 patients. On ventro-dorsal classification; unilateral lesions were found ventrally in 19, ventromedially in 11, and ventro-medio-dorsally in 4 patients. The median follow-up duration was 20 months (interquartile range (IQR); 1-60). According to the third-month mRS, 39% of the patients were considered to have a good prognosis.
CONCLUSION
The most common etiology was distal vertebral artery atherosclerosis. More than 50% of the patients could walk unassisted in the long-term follow-up, and stroke recurrence was infrequent. Patients with bilateral MMI had poor outcomes.
Topics: Humans; Male; Middle Aged; Female; Aged; Prognosis; Medulla Oblongata; Brain Stem Infarctions; Retrospective Studies
PubMed: 38010575
DOI: 10.1007/s13760-023-02427-3 -
Zootaxa Mar 2023We provide a morphological and molecular-based description of the eumonostiliferous hoplonemertean Oerstedia fuscosparsa sp. nov. based on two specimens dredged from a...
We provide a morphological and molecular-based description of the eumonostiliferous hoplonemertean Oerstedia fuscosparsa sp. nov. based on two specimens dredged from a depth between 11 and 18 m off Kouyatsu, Tateyama, Chiba, Japan. This Oerstedia differs from its congeners by having a deep brownish pigmentation in the head, four orange ocelli, and imprecise dorsal and ventral transverse bands composed of numerous small brown spots. One of the specimens, herein designated as the holotype, has deep brown spots situated mid-dorsally onto the transverse bands running throughout the body. These dorsal markings are absent in the other specimen designated as a paratype. Internally, the species has accessory lateral nerves, and the proboscis nerves are not distinct. Molecular phylogenetic analyses based on partial sequences of the 16S, 18S, 28S rRNA, cytochrome c oxidase subunit I, and histone H3 gene markers along with the sequences from 22 Oerstedia species available in public databases confirmed that our species is sister to Oerstedia phoresiae (Kulikova, 1987) and belongs to the recently established Paroerstediella clade within the genus Oerstedia.
Topics: Animals; Phylogeny; Japan; Acanthocephala; RNA, Ribosomal, 28S; Pigmentation
PubMed: 37044743
DOI: 10.11646/zootaxa.5249.5.6 -
Journal of Orthopaedics Dec 2016Fracture of the distal radius is a common clinical problem. Complex fracture requires open reduction and stabilization with plating to restore anatomy. Dorsal plating...
INTRODUCTION
Fracture of the distal radius is a common clinical problem. Complex fracture requires open reduction and stabilization with plating to restore anatomy. Dorsal plating has advantages of buttressing the fracture better but often complicated with tendon problems as per literature. The rate of complications however, was not compared between the low-profile dorsal and the volar plates.
METHODOLOGY
This was a retrospective study on seventy one patients with dorsally angulated or displaced distal radius fractures, who underwent fixation of fractures with either dorsal or volar locking plate from Jan - Nov 2012. Preoperative radiographs were classified based on Universal and Fernandez classification. Postoperative radiographs were assessed for anatomical restoration of Radial length, radial inclination and volar tilt. Tendon and nerve related complications were assessed and functional evaluation was performed on the basis of PRWE (Patient related wrist evaluation) score.
RESULTS
Both groups were matched for their demographic profile and fracture types (p 0.033). Dorsal plating group had 89% excellent/good restoration and fair in 11%. Volar group had 96% excellent/good restoration and fair in 4%. Statistical analysis was performed with unpaired t test for radiographic parameters. Three patients had tendon related complications in dorsal plating group; two patients in volar group had nerve related complications. Functional outcome with PRWE was comparable between two groups.
CONCLUSION
Results with low profile dorsal plating were comparable to volar plating. Therefore dorsal plating can be used as an alternative method when dorsal buttressing of comminuted fracture is required, especially with concomitant osteoporosis.
PubMed: 27504057
DOI: 10.1016/j.jor.2016.06.017 -
Veterinary and Comparative Orthopaedics... Sep 2023The aim of this study was to define landmarks of the intermetatarsal channel of the dorsal pedal artery and to assess whether damage to the dorsal pedal artery during...
OBJECTIVES
The aim of this study was to define landmarks of the intermetatarsal channel of the dorsal pedal artery and to assess whether damage to the dorsal pedal artery during metatarsal screw placement in dogs undergoing pan- and partial-tarsal arthrodesis (PanTA/ParTA) could be a mechanism in the development of plantar necrosis.
STUDY DESIGN
This study was divided in to two parts: (1) ex-vivo anatomical study: 19 canine cadavers, (2) retrospective clinical study: 39 dogs. Cadaveric dissection documented the mean intermetatarsal channel position. Metatarsal screw position was evaluated on postoperative radiographs of dogs after PanTA or ParTA. Screw position, arthrodesis type and surgical approach were assessed for their impact on complications, including plantar necrosis.
RESULTS
The mean proximal and distal extent of the intermetatarsal channel lies between 4.3% ± 1.9 and 22.8% ± 2.9 the length of metatarsal III (MTIII) respectively. The intermetatarsal channel lies within the most proximal 25% of MTIII in 95% of cases. At least one screw risked damaging the mean intermetatarsal channel position in 92% of dogs; 8% of these dogs went on to develop plantar necrosis. The mean screw position did not differ between ParTA cases with or without plantar necrosis ( > 0.05).
CONCLUSION
Violation of the intermetatarsal channel is possible during metatarsal screw placement. Care should be taken when placing screws in the proximal 25% of the metatarsals, specifically avoiding exiting dorsally between MTII and MTIII and across the distal region of the intermetatarsal channel, where the perforating metatarsal artery passes interosseously, as damage may contribute to the aetiology of plantar necrosis.
Topics: Dogs; Animals; Retrospective Studies; Metatarsal Bones; Metatarsus; Risk Factors; Arthrodesis; Cadaver; Dog Diseases
PubMed: 37142232
DOI: 10.1055/s-0043-57222 -
American Journal of Veterinary Research Jan 2024To describe the acquisition and pitfalls of a 3-view transesophageal echocardiography (TEE) protocol in anesthetized, dorsally recumbent dogs.
OBJECTIVE
To describe the acquisition and pitfalls of a 3-view transesophageal echocardiography (TEE) protocol in anesthetized, dorsally recumbent dogs.
ANIMALS
8 beagles, 1 to 2 years old, 7.4 to 11.2 kg.
METHODS
Dogs were anesthetized, mechanically ventilated, and placed in dorsal recumbency. A TEE probe was advanced, and 3 views were performed: midesophageal 4-chamber and long axis (ME 4C and ME LAX) and caudal esophageal short axis (CE SAX) at the level of the papillary muscles. Probe insertion depth, flexion, omniplane angle, and image acquisition time were recorded. Two observers assessed 24 video clips each and identified anatomical structures.
RESULTS
The ME 4C and ME LAX were obtained at 35 (30 to 40) cm insertion depth, omniplane at 0° and 103° (90 to 116), respectively. Views were obtained in ≤30 seconds once the TEE was in the cervical esophagus. Left-sided structures were identified in all cases, whereas right-sided structures were not always simultaneously obtained in the ME 4C, requiring further probe manipulation. All structures were identified on ME LAX. CE SAX was obtained at 40 (35 to 45) cm, omniplane at 0°, and in 15 (10 to 90) seconds. A true SAX view (circular left ventricle at the level of papillary muscles) could not be obtained in all dogs.
CLINICAL RELEVANCE
A 3-view TEE protocol using core views as those described in humans may be applicable to dogs under general anesthesia and in dorsal recumbency. The CE SAX view at the level of the papillary muscles appears more difficult to obtain with consistency than midesophageal views.
Topics: Humans; Animals; Dogs; Echocardiography, Transesophageal; Anesthesia, General; Heart Ventricles
PubMed: 38035479
DOI: 10.2460/ajvr.23.07.0176 -
BioRxiv : the Preprint Server For... Apr 2024Recent studies in vertebrates and have reshaped models of how the axon guidance cue UNC-6/Netrin functions in dorsal-ventral axon guidance, which was traditionally...
Recent studies in vertebrates and have reshaped models of how the axon guidance cue UNC-6/Netrin functions in dorsal-ventral axon guidance, which was traditionally thought to form a ventral-to-dorsal concentration gradient that was actively sensed by growing axons. In the vertebrate spinal cord, floorplate Netrin1 was shown to be largely dispensable for ventral commissural growth. Rather, short range interactions with Netrin1 on the ventricular zone radial glial stem cells was shown to guide ventral commissural axon growth. In , analysis of dorsally-migrating growth cones during outgrowth has shown that growth cone polarity of filopodial extension is separable from the extent of growth cone protrusion. Growth cones are first polarized by UNC-6/Netrin, and subsequent regulation of protrusion by UNC-6/Netrin is based on this earlier-established polarity (the Polarity/Protrusion model). In both cases, short-range or even haptotactic mechanisms are invoked: in vertebrate spinal cord, interactions of growth cones with radial glia expressing Netrin-1; and in a potential close-range interaction that polarizes the growth cone. To explore potential short-range and long-range functions of UNC-6/Netrin, a potentially membrane-anchored transmembrane UNC-6 (UNC-6(TM)) was generated by genome editing. was hypomorphic for dorsal VD/DD axon pathfinding, indicating that it retained some function. Polarity of VD growth cone filopodial protrusion was initially established in , but was lost as the growth cones migrated away from the source in the ventral nerve cord. In contrast, ventral guidance of the AVM and PVM axons was equally severe in and . Together, these results suggest that retains short-range functions but lacks long-range functions. Finally, ectopic expression from non-ventral sources could rescue dorsal and ventral guidance defects in and . Thus, a ventral directional source of UNC-6 was not required for dorsal-ventral axon guidance, and UNC-6 can act as a permissive, not instructive, cue for dorsal-ventral axon guidance. Possibly, UNC-6 is a permissive signal that activates cell-intrinsic polarity; or UNC-6 acts with another signal that is required in a directional manner. In either case, the role of UNC-6 is to polarize the pro-protrusive activity of UNC-40/DCC in the direction of outgrowth.
PubMed: 38712249
DOI: 10.1101/2024.04.23.590737 -
Consciousness and Cognition Sep 2015With the introduction of continuous flash suppression (CFS) as a method to render stimuli invisible and study unconscious visual processing, a novel hypothesis has... (Review)
Review
With the introduction of continuous flash suppression (CFS) as a method to render stimuli invisible and study unconscious visual processing, a novel hypothesis has gained popularity. It states that processes typically ascribed to the dorsal visual stream can escape CFS and remain functional, while ventral stream processes are suppressed when stimuli are invisible under CFS. This notion of a CFS-specific "dorsal processing bias" has been argued to be in line with core characteristics of the influential dual-stream hypothesis of visual processing which proposes a dissociation between dorsally mediated vision-for-action and ventrally mediated vision-for-perception. Here, we provide an overview of neuroimaging and behavioral studies that either examine this dorsal processing bias or base their conclusions on it. We show that both evidence for preserved ventral processing as well as lack of dorsal processing can be found in studies using CFS. To reconcile the diverging results, differences in the paradigms and their effects are worthy of future research. We conclude that given the current level of information a dorsal processing bias under CFS cannot be universally assumed.
Topics: Brain; Functional Neuroimaging; Humans; Perceptual Masking; Visual Perception
PubMed: 25649867
DOI: 10.1016/j.concog.2014.12.010