A three-dimensional geometric morphometric analysis of the morphological transformation of Caiman lower jaw during post-hatching ontogeny.

Shape ontogenetic changes of the lower jaw in crocodylians are poorly understood. In order to answer some questions related to the inter- and intraspecific morphological variation of the mandible of two extant Caiman species, we performed a three-dimensional geometric morphometric approach. For this purpose, we used landmarks and semilandmarks on two ontogenetic mandibular series of 48 and 15 post-hatching specimens of C. yacare and C. latirostris, respectively. We have also examined the relationship between these anatomical transformations and ontogenetic shifts in diet. We performed a principal component analysis (PCA) for the two species, and regression and partial least squares (PLS) analyses for each species, separately. As a result, species were segregated along the PC1 with specimens of C. yacare showing more gracile mandibles, and specimens of C. latirostris more robust ones. The PC2 and regression analyses showed an age gradient and represented ontogenetic shape changes. Adult caiman mandibles are higher and wider than juvenile ones, and shape changes are more conspicuous in C. latirostris. The PLS analyses showed a significant relationship between shape and diet. Morphological changes of the PLS1 of block-1 match with those of the regression analysis for both species. We have detected morphological transformations in areas where the musculature in charge of mandibular movements is attached. Common morphological changes occurring during ontogeny seem to reflect the same mechanical properties required for crushing and killing in both species, driven by an ontogenetic shift in the diet from invertebrates to vertebrates. Additionally, interspecific differences were also found to be correlated to ontogenetic changes in diet and could be related to dissimilar feeding mechanical requirements (e.g., stiffness and toughness of the item consumed), and to different habitat preferences. Robust mandibles would be more suitable for shallow and fully vegetated environments, as it can be seen in C. latirostris, whereas slender jaws seem to be more suitable for more aquatic species such as C. yacare.

Iron, vitamins and minerals status in pediatric patients with celiac diseaseand non celiac gluten sensitivity prior to diagnosis and three months later.

AIM: Pathologies associated with gluten intake are increasingly prevalent. Diagnosis of celiac disease (CD) or non-celiac gluten sensitivity (NCGS) is based on compatible clinical alterations and in case of CD on compatible serology or intestinal biopsy. The aim was to determine the values of iron, vitamins and minerals prior to diagnosis and to verify whether a gluten-free diet treatment can cause the normalization of these parameters both in patients diagnosed with celiac disease and gluten sensitivity. METHODS: Retrospective observational study from November 2016 to November 2021. 101 celiac patients and 26 with NCGS were included, all under 18 years of age. Levels of Fe, Na+ , K+ , Cl-, Ferritin, Ca2 + , P, Vitamin B12, Vitamin D and Transferrin were determined, following the quality standards of the Hospital Clínico San Carlos laboratory. Statistical software IBM SPSS Statistics v.26 was used. RESULTS: Calcium levels in celiac patients follow a positive trend after 3 months of gluten-free diet. Ferritin levels in patients with NCGS increased in a statistically significant way (p < 0.017). CONCLUSION: Calcium in the CD group increases its values after the establishment of a gluten-free diet as treatment, as well as ferritin in patients with NCGS. No significant changes were found in the rest of the analyzed parameters. This could be due to the precocity of the diagnosis thanks to a rapid clinical suspicion that determines few analytical alterations.

Antibiotic Prescribing Patterns for Pediatric Urgent Care Clinicians.

OBJECTIVE: Previous studies have reported high rates of inappropriate antibiotic prescriptions in urgent care (UC). Specific prescribing patterns for the most common diagnoses are not known. The aim of the study is to determine the diagnoses for which antibiotics are prescribed in pediatric UC settings. METHODS: We recruited pediatric UC providers via email to participate in a national multisite quality improvement study. Participants completed a survey on 10 consecutive encounters in which an antibiotic was given between March and May 2018. Encounters in which only topical antibiotics were prescribed were excluded. We categorized the encounters into 3 previously established tiers to determine appropriateness of antibiotic use. The tiers represent a descending order for antibiotic need based on diagnoses, with the first tier representing diagnoses almost always requiring antibiotics and the third tier representing diagnoses when an antibiotic is almost never required. We reported the diagnoses and frequency of antibiotic prescription within each tier. RESULTS: The 157 providers from 20 institutions submitted a total of 2809 encounters. We excluded 339 encounters in which only topical antibiotics were prescribed. Most diagnoses fell into the tier 2 category (85.81%), with only 9.12% in tier 1 and 5.06% in tier 3. The most common diagnoses reported were acute otitis media (48.96%), pharyngitis (25.09%), and skin and soft tissue infections (7.29%). CONCLUSIONS: In this sample of pediatric UC encounters, only 5% of diagnoses receiving antibiotic prescriptions were made up of tier 3 diagnoses, determined to almost never require antibiotics. While viral respiratory infections have been reported to frequently be treated with antibiotics in general UC centers, our study of pediatric UC centers showed that this was infrequent. However, otitis media with effusion and otalgia should be further investigated. With most antibiotic prescriptions being tier 2 diagnoses, pediatric UC providers can use evidence-based prescribing practices, shared decision making, and contingency plans to reduce unnecessary antibiotic exposure.

On the homology of crocodylian post-dentary bones and their macroevolution throughout Pseudosuchia.

The lower jaw of early tetrapods is composed of several intramembranous ossifications. However, a tendency toward the independent reduction of the number of bones has been observed in the mandible of mammals, lepidosaurs, turtles, crocodiles, and birds. Regarding archosaurs, the coronoid and prearticular bones are interpreted to be lost during the evolution of stem-birds and stem-crocodiles, respectively, but the homology of the post-dentary bones retained in living pseudosuchians remains unclear. Here, we combine paleontological and embryological evidence to explore in detail the homology of the crocodylian post-dentary bones. We study the mandible embryogenesis on a sample of 71 embryos of Caiman and compare this pattern with the mandibular transformations observed across pseudosuchian evolution. In the pre-hatching ontogeny of caimans, at least five intramembranous ossification centers are formed along the margins of the internal mandibular fenestra (perifenestral centers) and, subsequently, merge to form the coronoid (three intramembranous centers), angular (one intramembranous center), and articular (one intramembranous and one chondral center). In the fossil record, an independent prearticular is lost around the base of Mesoeucrocodylia (optimized as reappearing in Thalattosuchia if they are placed within Neosuchia), and the coronoid is apomorphically lost in notosuchians. The integration of embryological and paleontological data indicates that most perifenestral centers are involved in the origin of the prearticular of non-mesoeucrocodylian pseudosuchians. These centers are rearranged during the evolution to contribute to different post-dentary bones in mesoeucrocodylians bolstering the idea that the coronoid and the articular of Crocodylia are not completely homologous to those of other diapsids.

New embryological and palaeontological evidence sheds light on the evolution of the archosauromorph ankle.

The homology and evolution of the archosaur ankle is a controversial topic that has been deeply studied using evidence from both extinct and extant taxa. In early stem archosaurs, the astragalus and calcaneum form the ancestral proximal tarsus and a single ossification composes the centrale series. In more recent stem archosaurs, the centrale is incorporated to the proximal row of tarsals laterally contacting the astragalus. This bone is subsequently lost as an independent ossification before the last common ancestor of birds and crocodilians, but the evolutionary fate of this element remains mostly unexplored. Here, we integrate embryological and palaeontological data with morphogeometric analyses to test the hypothesis of loss of the centrale or, alternatively, its incorporation into the archosaurian astragalus. Our results support the latter hypothesis, indicating that the astragalus developed ancestrally from two ossification centres in stem archosaurs and that the supposed tibiale of bird embryos represents a centrale. This conclusion agrees with previous embryological studies that concluded that the tibiale never develops in diapsids.

Cranial shape variation in jacarean caimanines (Crocodylia, Alligatoroidea) and its implications in the taxonomic status of extinct species: The case of Melanosuchus fisheri.

Melanosuchus niger (Crocodylia, Alligatoroidea) is one of the six living caimanine species widely distributed throughout the Amazon River basin today. Although there is only one extant species of Melanosuchus, fossil material assigned to this genus, represented by M. fisheri, has been reported from the late Miocene in South America. However, the validity of this taxon has been questioned and a recent investigation indicates that the referred specimen of M. fisheri (MCZ 4336) actually belongs to Globidentosuchus brachyrostris, while those diagnostic characters present in the holotype (MCNC 243) fall into the spectrum of intraspecific variation of M. niger. Here, we compare the skull shape of the holotype of M. fisheri with the ontogenetic series of the four jacarean species (M. niger, Caiman yacare, Caiman crocodilus, and Caiman latirostris) using 2D-geometric morphometric analyses in two different views. The analyses indicate that MCNC 243 falls into the morphospace of M. niger and C. latirostris. Despite strong shape similarities between juveniles of C. latirostris and MCNC 243, further anatomical comparisons reveal notable differences between them. In contrast, no concrete anatomical differences can be found between MCNC 243 and M. niger, although shape analyses indicate that MCNC 243 is relatively robust for its size. Thus, this study is able to confirm that the genus Melanosuchus was present in the late Miocene, but it still remains unclear if MCNC 243 should be treated as a junior synonym or probably a sister species of M. niger. Its Miocene age favors the second option, but as the shape analyses were also not able to extract any diagnostic characters, it should be retained as Melanosuchus cf. niger.