Low coverage sequencing provides insights into the key features of the nuclear and mitochondrial genomes of the Alligator Snapping Turtle Macrochelys temminckii.

The alligator snapping turtle Macrochelys temminckii is a culturally, ecologically, and evolutionary relevant species of conservation concern. In this study, we conducted a genome survey of M. temminckii. Using a low-coverage short read sequencing strategy, this study estimated the genome size, repetitive genome content, annotated and quantified repetitive elements, assembled the 45S rRNA DNA operon, and characterized in detail the mitochondrial genome of M. temminckii. Using a k-mer strategy, the estimated haploid genome size varied between 3.77 and 3.19 Gbp, which is within the range previously reported for other representatives of the family Chelydridae. Repetitive genome content estimates using different k-mers (21 to 51) indicated that more than 75 % of the genome of M. temminckii comprised repetitive elements. Taking into account only annotated repetitive elements, the most common repetitive elements were classified as Class I - Long Interspersed Nuclear Element (LINE) which were more abundant than Class I - Penelope and Class I - Long Terminal Repeat (LTR) Ty3 mobile elements. Less abundant repeat element families in the nuclear genome of M. temminckii included Class I - DIRS mobile elements and Satellite DNA. The nuclear ribosomal operon was partially assembled into three contigs, one encoding the complete ssrRNA gene, a second encoding the complete 5.8S rRNA gene, and a third comprising the full lsrRNA gene. The AT-rich complete mitochondrial genome was 16,570 bp long. These new genomic resources are of utmost importance to aid in the development of conservation plans for this iconic freshwater turtle.

Immune-Mediated Necrotizing Myopathy With Concurrent Statin Use After Routine COVID-19 Inoculation: A Case Report.

SARS-CoV-2 has been associated with multiple disease processes and chronic sequela. Much less understood are the neurological effects, ranging from headaches, pro-thrombotic state, encephalitis, and myopathic processes. Many case reports have documented post-SARS-CoV-2 virus effects; however, this case highlights the possibility of a less commonly described neurological manifestation possibly related to the BNT162b2 mRNA Pfizer vaccine. There is scant literature on immune-mediated necrotizing myopathy (IMNM) triggered after COVID-19 vaccination. The BNT162b2 mRNA COVID-19 vaccine (Pfizer, BioNTech) has proven to be safe and effective in reducing transmission of COVID-19, but post-vaccination neurological events, including venous sinus thrombosis, transverse myelitis, and immune-mediated diseases, such as Guillain-Barré syndrome, have been reported. We report a case of IMNM with HMG-CoA reductase antibody positivity in the setting of BNT162b2 vaccination. The patient presented with progressive muscle weakness with rhabdomyolysis and necrotizing autoimmune myopathy proven on muscle biopsy after the second dose of the BNT162b2 vaccine. Ultimately, this case report highlights the importance of clinical suspicion for early diagnosis and initiation of treatment after symptoms concerning necrotizing myopathy.

Management of Pre-existing Ventriculoperitoneal Shunt in Posterior Vault Distraction for Lambdoid Craniosynostosis: A Case Report and Technical Note.

Posterior vault distraction osteogenesis (DO) is an emerging treatment option for craniosynostosis. Operative nuances detailing surgical management are being described with increasing use and experience. In this article, we discuss the surgical management of an 8-month-old male with a ventriculoperitoneal shunt (VPS) diagnosed with bilateral lambdoid craniosynostosis and Chiari I malformation. The patient underwent successful bilateral posterior fossa DO without surgical re-implantation of the shunt. Pre- and post-operative imaging confirmed no migration of the VPS. Intracranial volume increased by 20.1% and posterior fossa volume increased by 39.9%. Our experience illustrates that posterior vault DO can be done safely in the setting of a parieto-occipital VPS, in a single operative setting, without the need of additional procedures.

Three-Dimensional Volumetric Changes in Posterior Vault Distraction With Distraction Osteogenesis.

OBJECT: Distraction osteogenesis (DO) may allow for maximal volumetric expansion in the posterior vault (PV) by overcoming viscoelastic forces of overlying soft tissues. Little evidence exists regarding surgical planning and anticipated 3D volumetric changes pre- and post-operatively. We aim to study the volumetric changes occurring in PV distraction in lambdoid craniosynostosis. METHODS: From 2007 to 2019, a single institution retrospective review revealed 232 craniosynostosis patients. Fourteen demonstrated lambdoid synostosis (6%), and of those, 11 patients were included in the study due to treatment with PVDO or representative sample. Six patients had unilateral synostosis and 5 had bilateral synostosis. Imaging protocol for PVDO patients included preoperative head CT within 1 month of surgery and 8 weeks following distraction cessation with weekly skull plain films. 3D volumetric analyses were performed on pre and postoperative head CT using 3D Slicer software. RESULTS: Posterior fossa volume (PFV) increased by 38.7% and foramen magnum area increased by 26.9% postoperatively. Unilateral lambdoid craniosynostosis patients had greater increases in PFV versus bilateral lambdoid craniosynostosis patients (63.5% versus 8.9%, P = 0.007). Osteotomy to the asterion was more effective in increasing PFV versus osteotomy to foramen magnum (P = 0.050). Placement of distractor in the inferior third of the lambdoid suture is more effective in increasing PFV versus placement in the middle or top third of the suture (P = 0.041). CONCLUSIONS: Highest volumetric increases are seen in unilateral lambdoid synostosis. Extending osteotomy beyond the asterion is not necessary for maximal PV volumetric gain. Placement of distractor in the inferior third of the suture leads to maximal PV volumetric gains.