scholarly journals Plicidentine and the repeated origins of snake venom fangs

2021 ◽  
Vol 288 (1956) ◽  
pp. 20211391
Author(s):  
Alessandro Palci ◽  
Aaron R. H. LeBlanc ◽  
Olga Panagiotopoulou ◽  
Silke G. C. Cleuren ◽  
Hyab Mehari Abraha ◽  
...  

Snake fangs are an iconic exemplar of a complex adaptation, but despite striking developmental and morphological similarities, they probably evolved independently in several lineages of venomous snakes. How snakes could, uniquely among vertebrates, repeatedly evolve their complex venom delivery apparatus is an intriguing question. Here we shed light on the repeated evolution of snake venom fangs using histology, high-resolution computed tomography (microCT) and biomechanical modelling. Our examination of venomous and non-venomous species reveals that most snakes have dentine infoldings at the bases of their teeth, known as plicidentine, and that in venomous species, one of these infoldings was repurposed to form a longitudinal groove for venom delivery. Like plicidentine, venom grooves originate from infoldings of the developing dental epithelium prior to the formation of the tooth hard tissues. Derivation of the venom groove from a large plicidentine fold that develops early in tooth ontogeny reveals how snake venom fangs could originate repeatedly through the co-option of a pre-existing dental feature even without close association to a venom duct. We also show that, contrary to previous assumptions, dentine infoldings do not improve compression or bending resistance of snake teeth during biting; plicidentine may instead have a role in tooth attachment.

2000 ◽  
Vol 42 (3) ◽  
pp. 473
Author(s):  
Dae Sik Ryu ◽  
Kun Sang Kim ◽  
Kil Hyen Kang ◽  
Haing Sup Chung ◽  
Bung Wok Lee ◽  
...  

2000 ◽  
Vol 42 (5) ◽  
pp. 757
Author(s):  
Myung Hee Chung ◽  
Hae Giu Lee ◽  
Won Jong Yu ◽  
Hong Jun Chung ◽  
Bo Sung Yang ◽  
...  

2014 ◽  
Author(s):  
Jaime Pena ◽  
Graeme Campbell ◽  
Timo Damm ◽  
Reinhard Barkmann ◽  
Sonja Waldhausen ◽  
...  

Author(s):  
Alina S. Kovaleva ◽  
Igor V. Bukhtiyarov ◽  
Natalya S. Serova ◽  
Tatyana B. Burmistrova

Respiratory system diseases are one of the main problems in contemporary occupational medicine and exceed one fifth of all occupational diseases. Objective of the review was search and analysis of literature on diagnosis of silicosis as an important occupational disease of respiratory organs, by computed tomography and high-resolution computed tomography, from evidence-based medicine viewpoint.


1990 ◽  
Vol 31 (1) ◽  
pp. 27-31
Author(s):  
M. Isono ◽  
K. Murata ◽  
F. Ohta ◽  
A. Yoshida ◽  
O. Ishida

Author(s):  
Marco Tana ◽  
Silvio di Carlo ◽  
Marcello Romano ◽  
Massimo Alessandri ◽  
Cosima Schiavone ◽  
...  

Background:18F-fluorodeoxyglucose positron emission tomography integrated with computed tomography (18-F-FDG-PET/CT) is getting wide consensus in the diagnosis and staging of neoplastic disorders and represents a useful tool in the assessment of various inflammatory conditions. </P><P> Discussion: Sarcoidosis is an uncommon disease characterized by the systemic formation of noncaseating granulomas. Lungs are the sites most often affected, and investigation with high resolution computed tomography and biopsy is essential to achieve a correct diagnosis. 18-F-FDGPET/ CT is effective in the assessment of pulmonary sarcoidosis by demonstrating pulmonary and extrathoracic involvement and findings correlate well with pulmonary function in patients affected.Conclusion:This review would illustrate the usefulness and limits of 18-F-FDG-PET/CT in the assessment of pulmonary sarcoidosis.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1598.2-1599
Author(s):  
I. Rusu ◽  
L. Muntean ◽  
M. M. Tamas ◽  
I. Felea ◽  
L. Damian ◽  
...  

Background:Interstitial lung disease (ILD) is a common manifestation of connective tissue diseases (CTDs), and is associated with significant morbidity and mortality. Chest high-resolution computed tomography (HRCT) play an important role in the diagnosis of ILD and may provide prognostic information.Objectives:We aimed to characterize the clinical profile and chest HRCT abnormalities and patterns of patients diagnosed with CTDs and ILD.Methods:In this retrospective, observational study we included 80 consecutive patients with CTDs and ILD referred to a tertiary rheumatology center between 2015 and 2019. From hospital charts we collected clinical data, immunologic profile, chest HRCT findings. HRCT patterns were defined according to new international recommendations.Results:Out of 80 patients, 64 (80%) were women, with a mean age of 55 years old. The most common CTD associated with ILD was systemic sclerosis (38.8%), followed by polymyositis (22.5%) and rheumatoid arthritis (18.8%). The majority of patients had dyspnea on exertion (71.3%), bibasilar inspiratory crackles were present in 56.3% patients and 10% had clubbing fingers. Antinuclear antibodies (ANA) were present in 78.8% patients, and the most frequently detected autoantibodies against extractable nuclear antigen were anti-Scl 70 (28.8%), followed by anti-SSA (anti-Ro, 17.5%), anti-Ro52 (11.3%) and anti-Jo (7.5%). Intravenous cyclophosphamide therapy for 6-12 months was used in 35% of patients, while 5% of patients were treated with mycophenolate mofetil.The most frequent HRCT abnormalities were reticular abnormalities and ground glass opacity. Non-specific interstitial pneumonia (NSIP) was identified in 46.3% CTDs patients. A pattern suggestive of usual interstitial pneumonia (UIP) was present in 32.5% patients, mainly in patients with systemic sclerosis. In 21.3% patients the HRCT showed reticulo-nodular pattern, micronodules and other abnormalities, not diagnostic for UIP or NSIP pattern.Conclusion:Nonspecific interstitial pneumonia (NSIP) is the most common HRCT pattern associated with CTDs. Further prospective longitudinal studies are needed in order to determine the clinical and prognostic significance of various HRCT patterns encountered in CTD-associated ILD and for better patient management.References:[1]Ohno Y, Koyama H, Yoshikaua T, Seki S. State-of-the-Art Imaging of the Lung for Connective Tissue Disease (CTD). Curr Rheumatol Rep. 2015;17(12):69.[2]Walsh SLF, Devaraj A, Enghelmeyer JI, Kishi K, Silva RS, Patel N, et al. Role of imaging in progressive-fibrosing interstitial lung diseases. Eur Respir Rev. 2018;27(150)Disclosure of Interests:None declared


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