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Frontiers in Cell and Developmental... 2023Understanding the remarkable capacity of vertebrates to naturally regenerate injured body parts has great importance for potential translation into human therapeutic... (Review)
Review
Understanding the remarkable capacity of vertebrates to naturally regenerate injured body parts has great importance for potential translation into human therapeutic applications. As compared to other vertebrates, mammals have low regenerative capacity for composite tissues like the limb. However, some primates and rodents can regenerate the distal tips of their digits following amputation, indicating that at least very distal mammalian limb tissues are competent for innate regeneration. It follows that successful digit tip regenerative outcome is highly dependent on the location of the amputation; those proximal to the position of the nail organ do not regenerate and result in fibrosis. This distal regeneration proximal fibrosis duality of the mouse digit tip serves as a powerful model to investigate the driving factors in determining each process. In this review, we present the current understanding of distal digit tip regeneration in the context of cellular heterogeneity and the potential for different cell types to function as progenitor cells, in pro-regenerative signaling, or in moderating fibrosis. We then go on to discuss these themes in the context of what is known about proximal digit fibrosis, towards generating hypotheses for these distinct healing processes in the distal and proximal mouse digit.
PubMed: 37325560
DOI: 10.3389/fcell.2023.1217185 -
International Journal of Audiology Dec 2021This review article presents an overview of all Digit Triplet Tests (DTT) and digits-in-noise tests (DIN) and their variations in language, speech material, masking... (Review)
Review
OBJECTIVE
This review article presents an overview of all Digit Triplet Tests (DTT) and digits-in-noise tests (DIN) and their variations in language, speech material, masking noise, test procedures, and targeted population. The effects on aspects of validity, reliability, and feasibility are investigated.
DESIGN
Scoping review.
STUDY SAMPLE
All studies referring to the DTT and DIN were collected from Pubmed and Embase. Search terms "digit triplet test" and "digits in noise" were used. Citations of selected articles were scanned backwards in time (the bibliography of the already selected research article) and forward in time (articles that cited the already selected research article). The search terms yielded 95 results in total. Eventually, 39 papers were selected.
RESULTS
Analyses showed psychometric reference-curves with steep slopes and speech reception thresholds with high measurement precision which are strongly associated with pure tone audiometry. High sensitivity and specificity to detect elevated pure tone thresholds were noted for test variants. Certain procedural modifications of the DTT and DIN can further improve the test. Additionally, large-scale application of the DTT and DIN is feasible.
CONCLUSION
The DTT and DIN are a very valuable tool for screening and diagnostics for a wide variety of populations.
Topics: Audiometry, Pure-Tone; Humans; Noise; Reproducibility of Results; Speech Perception; Speech Reception Threshold Test
PubMed: 33840339
DOI: 10.1080/14992027.2021.1902579 -
British Journal of Hospital Medicine... Nov 2020Traumatic digit amputations account for 1% of all trauma admissions and are an important cause of morbidity in young, working people. It is essential that patients are... (Review)
Review
Traumatic digit amputations account for 1% of all trauma admissions and are an important cause of morbidity in young, working people. It is essential that patients are worked up appropriately and referred promptly to a specialist unit for consideration of replantation. This review summarises the acute management of a patient presenting to the emergency department with an amputated digit. It discusses the assessment, initial management in the emergency department, how to make the decision to replant and operative steps.
Topics: Amputation, Traumatic; Emergency Service, Hospital; Finger Injuries; Humans; Replantation
PubMed: 33263473
DOI: 10.12968/hmed.2020.0087 -
American Journal of Medical Genetics.... Jun 2022Limb deficiencies are a common birth defect. A malformations surveillance program among many newborns, stillborn fetuses, and malformed fetuses in elective terminations...
Limb deficiencies are a common birth defect. A malformations surveillance program among many newborns, stillborn fetuses, and malformed fetuses in elective terminations can identify a sufficient number of infants with the same set of abnormalities to characterize a specific limb deficiency phenotype. The active malformations surveillance program was carried out among 289,365 births at Brigham and Women's Hospital in Boston over a 41-year period (1972-2012). The research assistants identified the affected infants and fetuses from reading the findings recorded in each newborn's medical record by the examining pediatricians and consultants and by the pathologists in autopsies. One hundred ninety-four newborn infants and fetuses were found to have a limb deficiency either as an isolated abnormality or as one of multiple malformations. We identified three phenotypes of limb deficiency. We present here the seventeen infants and fetuses with "central digit hypoplasia," a term we suggest for this phenotype: hypoplasia of the thumb and fifth finger with nubbins of soft tissue in place of fingers 2, 3, and 4 at the level of the metacarpal-phalangeal joint. Central digit hypoplasia is to be distinguished primarily from the terminal transverse limb defect that ends at the wrist. In symbrachydactyly, the middle and distal phalanges of the fingers and toes are hypoplastic. In addition, central digit hypoplasia should be distinguished from the amniotic band syndrome, the most common and incorrect diagnosis suggested by the pediatricians and the consultants in this survey. The affected infant and her/his parents benefit from more accurate and specific counseling.
Topics: Abnormalities, Multiple; Amniotic Band Syndrome; Female; Fetus; Fingers; Humans; Infant, Newborn; Limb Deformities, Congenital
PubMed: 35234329
DOI: 10.1002/ajmg.a.62697 -
IEEE Transactions on Image Processing :... 2022Most existing studies on unsupervised domain adaptation (UDA) assume that each domain's training samples come with domain labels (e.g., painting, photo). Samples from...
Most existing studies on unsupervised domain adaptation (UDA) assume that each domain's training samples come with domain labels (e.g., painting, photo). Samples from each domain are assumed to follow the same distribution and the domain labels are exploited to learn domain-invariant features via feature alignment. However, such an assumption often does not hold true-there often exist numerous finer-grained domains (e.g., dozens of modern painting styles have been developed, each differing dramatically from those of the classic styles). Therefore, forcing feature distribution alignment across each artificially-defined and coarse-grained domain can be ineffective. In this paper, we address both single-source and multi-source UDA from a completely different perspective, which is to view each instance as a fine domain. Feature alignment across domains is thus redundant. Instead, we propose to perform dynamic instance domain adaptation (DIDA). Concretely, a dynamic neural network with adaptive convolutional kernels is developed to generate instance-adaptive residuals to adapt domain-agnostic deep features to each individual instance. This enables a shared classifier to be applied to both source and target domain data without relying on any domain annotation. Further, instead of imposing intricate feature alignment losses, we adopt a simple semi-supervised learning paradigm using only a cross-entropy loss for both labeled source and pseudo labeled target data. Our model, dubbed DIDA-Net, achieves state-of-the-art performance on several commonly used single-source and multi-source UDA datasets including Digits, Office-Home, DomainNet, Digit-Five, and PACS.
Topics: Algorithms; Neural Networks, Computer
PubMed: 35776810
DOI: 10.1109/TIP.2022.3186531 -
Journal of Morphology Sep 2022Alvarezsauroidea (Tetanurae) are nonavian theropod dinosaurs whose forelimb evolution is characterised by the overdevelopment of digit I, at the expense of the other two... (Review)
Review
Alvarezsauroidea (Tetanurae) are nonavian theropod dinosaurs whose forelimb evolution is characterised by the overdevelopment of digit I, at the expense of the other two digits, complemented by a drastic forelimb shortening in derived species (Parvicursorinae). These variations are recognised as evolutionary developmental anomalies. Evolutionary teratology hence leads to a double diagnosis with (1) macrodactyly of digit I and microdactyly of digits II and III, plus (2) anterior micromelia. The teratological macrodactyly/microdactyly coupling evolved first. Developmental mechanisms disturbing limb proportion are thought to be convergent with those of other Tetanurae (Tyrannosauridae, Carcharodontosauridae). As for the manual anomalies, both are specific to Alvarezsauroidea (macrodactyly/microdactyly) and inherited (digit loss/reduction). While considering the frame-shift theory, posterior digits develop before the most anterior ones. There would therefore be a decrease in the area devoted to digits II (condensation 3) and III (condensation 4), in connection with the Shh signalling pathway, interacting with other molecular players such as the GLI3 protein and the Hox system. Developmental independence of digit I (condensation 2) would contribute to generating a particular morphology. Macrodactyly would be linked to a variation in Hoxd-13, impacting Gli3 activity, and increasing cell proliferation. The loss/reduction of digital ray/phalanges (digits II and III), would be associated with Shh activity, a mechanism inherited from the theropodan ancestry. The macrodactyly/microdactyly coupling, and then anterior micromelia, fundamentally changed the forelimb mechanical function, compared to the 'classical' grasping structure of basal representatives and other theropods. The distal ossification of the macrodactylian digit has been identified as physiological, implying the use of the structure. However, the debate on a particular 'adaptive' use is pointless as the ecology of an organism is interactively complex, being both at the scale of the individual and dependent on circumstances. Other anatomical features also allow for compensation and different predation (cursorial hindlimbs).
Topics: Animals; Dinosaurs; Fingers; Forelimb; Hindlimb; Limb Deformities, Congenital; Teratology
PubMed: 35915891
DOI: 10.1002/jmor.21500 -
Development (Cambridge, England) Sep 2020The vertebrate limb continues to serve as an influential model of growth, morphogenesis and pattern formation. With this Review, we aim to give an up-to-date picture of... (Review)
Review
The vertebrate limb continues to serve as an influential model of growth, morphogenesis and pattern formation. With this Review, we aim to give an up-to-date picture of how a population of undifferentiated cells develops into the complex pattern of the limb. Focussing largely on mouse and chick studies, we concentrate on the positioning of the limbs, the formation of the limb bud, the establishment of the principal limb axes, the specification of pattern, the integration of pattern formation with growth and the determination of digit number. We also discuss the important, but little understood, topic of how gene expression is interpreted into morphology.
Topics: Animals; Body Patterning; Extremities; Gene Expression Regulation, Developmental; Limb Buds; Vertebrates
PubMed: 32917670
DOI: 10.1242/dev.177956