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The tropomyosin 1 isoform I/C C-terminal domain (Tm1-LC) fibril structure is studied jointly with cryogenic electron microscopy (cryo-EM) and solid state nuclear magnetic resonance (NMR). This study demonstrates the complementary nature of these two structural biology techniques. Chemical shift assignments from solid state NMR are used to determine the secondary structure at the level of individual amino acids, which is faithfully seen in cryo-EM reconstructions. Additionally, solid state NMR demonstrates that the region not observed in the reconstructed cryo-EM density is primarily in a highly mobile random coil conformation rather than adopting multiple rigid conformations. Overall, this study illustrates the benefit of investigations combining cryo-EM and solid state NMR to investigate protein fibril structure.

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Median arcuate ligament syndrome (MALS) is a rare condition in which the median arcuate ligament (MAL) exerts external compression on the celiac trunk. Most cases are asymptomatic and diagnosed incidentally on radiographic imaging; however, some patients may experience gastrointestinal (GI) symptoms related to foregut ischemia and/or celiac neuropathy. In the following case, we present a patient with hemorrhagic peptic ulcer disease of the duodenum, which resulted in episodes of hemodynamic instability requiring multiple blood transfusions. Upon attempted transarterial angioembolization of the gastroduodenal artery (GDA), celiac stenosis and retrograde arterial flow from the superior mesenteric artery confirmed the presence of MALS. This rendered GDA angioembolization a contraindication, as the GDA became the dominant arterial supply for the distal celiac organs. The patient then received open surgical MAL release with concurrent surgical ligation of the hemorrhaging duodenal artery, which resolved his symptoms without the need for further intervention.

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The phosphate-starvation response transcription-factor protein family is essential to plant response to low-levels of phosphate. Proteins in this transcription factor (TF) family act by altering various gene expression levels, such as increasing levels of the acid phosphatase proteins which catalyze the conversion of inorganic phosphates to bio-available compounds. There are few structural characterizations of proteins in this TF family, none of which address the potent TF activation domains. The phosphate-starvation response-like protein-4 (PHL4) protein from this family has garnered interest due to the unusually high TF activation activity of the N-terminal domain. Here, we demonstrate using solution nuclear magnetic resonance (NMR) measurements that the PHL4 N-terminal activating TF effector domain is mainly an intrinsically disordered domain of over 200 residues, and that the C-terminal region of PHL4 is also disordered. Additionally, we present evidence from size-exclusion chromatography, diffusion NMR measurements, and a cross-linking assay suggesting full-length PHL4 forms a tetrameric assembly. Together, the data indicate the N- and C-terminal disordered domains in PHL4 flank a central folded region that likely forms the ordered oligomer of PHL4. This work provides a foundation for future studies detailing how the conformations and molecular motions of PHL4 change as it acts as a potent activator of gene expression in phosphate metabolism. Such a detailed mechanistic understanding of TF function will benefit genetic engineering efforts that take advantage of this activity to boost transcriptional activation of genes across different organisms.

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The Tropomyosin 1 isoform I/C C-terminal domain (Tm1-LC) fibril structure is studied jointly with cryogenic electron microscopy (cryo-EM) and solid state nuclear magnetic resonance (NMR). This study demonstrates the complementary nature of these two structural biology techniques. Chemical shift assignments from solid state NMR are used to determine the secondary structure at the level of individual amino acids, which is faithfully seen in cryo-EM reconstructions. Additionally, solid state NMR demonstrates that the region not observed in the reconstructed cryo-EM density is primarily in a highly mobile random coil conformation rather than adopting multiple rigid conformations. Overall, this study illustrates the benefit of investigations combining cryo-EM and solid state NMR to investigate protein fibril structure.

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The pubic branches of the inferior epigastric and obturator arteries are subject to injury from pelvic trauma or surgery within the retropubic space. Such injuries can result in severe internal hemorrhage that can lead to hemodynamic instability if not adequately controlled. Due to their anatomical proximity and anastomosis, it is critical to determine which artery is hemorrhaging in order to provide accurate embolization. In the presented case, a geriatric patient suffered a fall from standing height that resulted in bilateral and multiple pelvic fractures. CT angiography of the abdomen demonstrated active left-sided pelvic hemorrhage and a resultant 10 cm anterior extraperitoneal hematoma, likely exacerbated by existing anticoagulant usage. Urgent embolization of the inferior epigastric artery was performed in addition to multiple transfusions. The patient recovered without any procedural complications and was later discharged for rehabilitation.

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Gastric intramural hematoma (GIH) is a contained hemorrhage located within the layers that comprise the wall of the stomach. It is a rare condition that has a variety of etiologies. Pancreatitis-induced GIH is an even rarer phenomenon, with only a handful of documented cases in the medical literature. In the current case, a patient presented with chronic abdominal pain for the past two months, with an acute worsening of symptoms. CT imaging confirmed a large, stable GIH with concomitant pancreatitis, likely alcohol-induced. Diagnostic laparoscopy was performed in response to worsening hemodynamic status, which confirmed hemorrhagic pancreatitis as the likely cause of the GIH formation. Jackson-Pratt (JP) drains were placed, and the patient was subsequently discharged. The patient returned one month later with an acute exacerbation of pancreatitis; however, interval improvement of the GIH was observed. The patient was transferred to outpatient care for continued conservative treatment without any further return visits.

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Chronic pancreatitis has been shown to cause various pathologies, such as biliary strictures and pancreatic malignancies, which can in turn result in biliary outlet obstruction. However, a pancreatic calculus itself resulting in biliary obstruction has been far less observed. The patient in question had a documented history of chronic alcoholism and received a cholecystectomy decades prior to the onset of cholestatic symptoms. Cholangiography demonstrated no indication of biliary stricture formation, nor was there radiological evidence of pancreatic pseudocyst or malignant formation. CT evidence across a decade of time established a storyline of pancreatic calculi formation, migration, and resultant biliary obstruction. Subsequent endoscopic sphincterectomy, pancreatic calculi removal, and biliary tree stent placement resulted in laboratory value normalization and clinical symptom resolution.

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The management of complicated cholecystitis in an elderly patient can present a complex clinical decision for surgeons. There is literature supporting the use of immediate laparoscopic cholecystectomy for cases of uncomplicated cholecystitis in elderly patients and complicated cholecystitis in the general population. There are, however, no clear guidelines for treating the unique presentation of an elderly patient with complicated cholecystitis. This is likely due to the many clinical risk factors that must be considered when caring for these complex patients often with many medical comorbidities. In this report, we present the case of an 81-year-old male with complicated chronic cholecystitis leading to the exceedingly rare complication of gastric outlet obstruction. The patient was successfully treated with percutaneous cholecystostomy tube placement and interval subtotal laparoscopic cholecystectomy.

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Agenesis or dysgenesis of the corpus callosum may occur due to ischemic, toxic, traumatic, or another insult to the fetus in the first trimester. Occasionally, such a malformation is associated with an interhemispheric cyst, among other central nervous system anomalies. Holoprosencephaly tends to mimic this radiographic presentation, which is where key imaging findings are helpful to differentiate between these entities. We present a 56-year-old male patient who was found to have a monoventricle, corpus callosum agenesis, interhemispheric cyst, and a Dandy-Walker malformation. The patient presented with a right acetabular fracture with computed tomography (CT) of the brain revealing the congenital brain abnormalities. The patient's past medical history was notable for a seizure disorder identified during early adulthood. The CT scan of the head revealed a large monoventricle with an associated midline dorsal interhemispheric cyst and a Dandy-Walker malformation. The absence of both the corpus callosum and septum pellucidum was noted, with the presence of a monoventricle, leading to an initial differential of holoprosencephaly. Further review of the findings suggested instead a rare congenital presentation consisting of corpus callosum agenesis and an interhemispheric cyst. This case highlights a unique radiographic presentation of multiple brain anomalies, rarely presented in non-pediatric literature, which may help determine appropriate surgical and medical management for similarly affected adult individuals.

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The plant secondary cell wall is a thickened matrix of polysaccharides and lignin deposited at the cessation of growth in some cells. It forms the majority of carbon in lignocellulosic biomass, and it is an abundant and renewable source for forage, fiber, materials, fuels, and bioproducts. The complex structure and arrangement of the cell wall polymers mean that the carbon is difficult to access in an economical and sustainable way. One solution is to alter the cell wall polymer structure so that it is more suited to downstream processing. However, it remains difficult to predict what the effects of this engineering will be on the assembly, architecture, and properties of the cell wall. Here, we make use of Arabidopsis plants expressing a suite of genes to increase pectic galactan chain length in the secondary cell wall. Using multi-dimensional solid-state nuclear magnetic resonance, we show that increasing galactan chain length enhances pectin-cellulose spatial contacts and increases cellulose crystallinity. We also found that the increased galactan content leads to fewer spatial contacts of cellulose with xyloglucan and the backbone of pectin. Hence, we propose that the elongated galactan side chains compete with xyloglucan and the pectic backbone for cellulose interactions. Due to the galactan topology, this may result in comparatively weak interactions and disrupt the cell wall architecture. Therefore, introduction of this strategy into trees or other bioenergy crops would benefit from cell-specific expression strategies to avoid negative effects on plant growth.

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We present the case of a pregnant 32-year-old woman who presented with a giant fetal facial tumour at 22 weeks. The mass, initially 4 × 3.5 × 3 cm in size, was largely cystic with a small solid component. It subsequently increased to 9 × 9 × 10 cm. Significant compression effects on the fetal orbit, temple and infratemporal fossa, with potential compression of the optic nerve, were noted on ultrasound and MRI. The cyst required drainage twice in the pregnancy: firstly to reduce the compression effects and secondly to facilitate caesarean delivery. Postnatally, the baby had significant compression and displacement of the craniofacial skeleton from the mass effect. Postnatal histology revealed a diagnosis of a teratoma. This case highlights the complexities and challenges surrounding the diagnosis and management of a giant fetal facial tumour.

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Protein domains biased toward a few amino acid types are vital for the formation of biomolecular condensates in living cells. These membraneless compartments are formed by molecules exhibiting a range of molecular motions and structural order. Missense mutations increase condensate persistence lifetimes or structural order, properties that are thought to underlie pathological protein aggregation. In the context of stress granules associated with neurodegenerative diseases, this process involves the rigidification of protein liquid droplets into ß-strand rich protein fibrils. Here, we characterize the molecular mechanism underlying the rigidification of liquid droplets for the low complexity domain of the Cytotoxic granule associated RNA binding protein TIA1 (TIA1) stress granule protein and the influence of a disease mutation linked to neurodegenerative diseases. A seeding procedure and solid state nuclear magnetic resonance measurements show that the low complexity domain converges on a ß-strand rich fibril conformation composed of 21% of the sequence. Additional solid state nuclear magnetic resonance measurements and difference spectroscopy show that aged liquid droplets of wild type and a proline-to-leucine mutant low complexity domain are composed of fibril assemblies that are conformationally heterogeneous and structurally distinct from the seeded fibril preparation. Regarding low complexity domains, our data support the functional template-driven formation of conformationally homogeneous structures, that rigidification of liquid droplets into conformationally heterogenous structures promotes pathological interactions, and that the effect of disease mutations is more nuanced than increasing thermodynamic stability or increasing ß-strand structure content.

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Retroperitoneal lymphatic malformations are rare, benign, cystic tumors of the lymphatic system, accounting for 1% of all lymphatic malformation manifestations. Lymphatic malformations are often asymptomatic, but may clinically present with abdominal pain and a palpable mass. Initial diagnostic workup is challenging due to the difficulty of differentiating from masses that may arise from the pancreas, liver, and kidney. This report describes a recurrent retroperitoneal lymphatic malformation in a 15-year-old male. The patient presented with abdominal pain and radiological imaging demonstrated abdominal fluid collection. Following conservative management using aspiration, the patient presented three months later with recurrent abdominal pain. Radiological imaging identified a large thin-walled cystic lesion in the right hemiabdomen containing minimal thin internal septations. Histological analysis confirmed the lymphatic malformation following computed tomography-guided biopsy. The patient underwent aspiration and was referred for outpatient sclerotherapy to prevent future abdominal fluid collection. This case highlights conservative management of recurrent retroperitoneal lymphatic malformation, both on the initial and subsequent presentation.

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Background: Systematic reviews have identified the need for a patient-reported outcome measure for facial nerve paralysis (FNP). The aim of this study was to determine the psychometric properties of FACE-Q Craniofacial module scales when used in a combined sample of children and older adults with FNP. Methods: Data were collected between December 2016 and December 2019. We conducted qualitative interviews with children and adults with FNP. FACE-Q data were collected from patients aged 8 years and older with FNP. Rasch measurement theory analysis was used to examine the reliability and validity of the relevant scales in the FNP sample. Results: Twenty-five patients provided 2052 qualitative codes related to appearance, physical, psychological, and social function. Many patient concerns were common across age. The field-test sample included 235 patients aged 8-81 years. Of the 13 scales examined, all 122 items had ordered thresholds and good item fit to the Rasch model. For 12 scales, person separation index values were ≥0.79 and Cronbach's alpha values were ≥0.82. The 13th scale's reliability values were ≥0.71. Conclusion: The FACE-Q Craniofacial module scales described in this study can be used to collect and compare evidence-based outcome data from children and adults with FNP.

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BACKGROUND: Blood loss and subsequent transfusion are key concerns in the surgical management of craniosynostosis, and have been associated with increased morbidity, requirement for intensive care admission and increased length of hospital stay. Patient blood management guidelines advocate treatment of anemia before elective surgical procedures where significant blood loss is anticipated. At present there is little evidence in the literature investigating the clinical value of this practice in pediatric craniofacial surgery. AIMS: The authors examined the effect of preoperative oral iron supplementation on blood loss and transfusion rates in a national pediatric craniofacial unit. METHODS: A total of 157 patients were included in a retrospective and prospective observational cohort study conducted between July 2011 and November 2016. Eighty-five (85) patients included in the preoperative iron supplementation group were prescribed oral ferrous fumarate before total cranial vault reconstruction, frontal-orbital advancement or extended strip cranial vault remodeling procedures. This cohort was retrospectively compared to seventy-two (72) consecutive patients who did not receive iron supplementation. RESULTS: Calculated blood loss was 51.3 mL/kg in the intervention group, and 56.65 mL/kg in the control group. Transfusion rate and mean volumes for the intervention group were 85.9% and 25 mL/kg. The control group had transfusion rate of 86.1% with mean transfused volume of 24.7 mL/kg. These differences were not statistically significant. Intraoperative tranexamic acid was associated with significantly reduced transfusion volumes overall. CONCLUSIONS: This study did not show a statistically significant benefit to preoperative iron supplementation. Secondary outcomes of this study showed a statistically significant difference in estimated versus calculated intraoperative blood loss. Further research in to specific iron supplementation protocols is indicated.

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ABSTRACT: A multitude of operations exists for the treatment of patients with sagittal craniosynostosis presenting after 6 months of age, of which total cranial vault remodeling now provides the most reliable aesthetic outcome. As our national craniofacial center evolved and began to develop a comprehensive multi-disciplinary team to manage complex surgical cases, we offered cranial vault distraction as an alternative to more invasive surgery for late presentation nonsyndromic scaphocephaly. The authors conducted a retrospective review of all patients undergoing this procedure.An average distraction distance of 39.4 mm was achieved in 15 patients aged 1 to 9 years. As a result, the cephalic index changed an average of 4%. The mean transfusion volume in the perioperative period was 32.47% of estimated blood volume. There were 2 complications requiring further operative intervention and distraction was stopped early in 1 patient.The authors propose that internal calvarial distraction is a viable alternative to total cranial vault remodeling for the management of late presentations of sagittal craniosynostosis.

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BACKGROUND: Resorbable plates are commonly used in cranial vault reconstruction surgery. There are few published papers examining their safety profile. The authors examined the prevalence of wound complications associated with the use of resorbable plates (Inion CPS Fixation System) in pediatric patients undergoing cranial vault reconstruction. METHODS: A retrospective review of patients (n = 182) who underwent cranial vault reconstruction using resorbable plate fixation was undertaken. All procedures were performed by a single Craniofacial Surgeon at the National Pediatric Craniofacial Center from 2008 to 2016. Wound complications were identified from a prospectively maintained database and medical note review. Several key patient characteristics and surgical variables were also recorded and tested for associations with wound complications. RESULTS: A total of 58.8% (107 of 182) of patients were male with a median age at surgery of 16.2 months. Overall, 12.1% (22 of 182) experienced a postoperative wound complication requiring hospital admission. A total of 2.73% (5 of 182) of the patients that returned to theatre had remnants of plates removed. The authors had a mean time from primary operation to secondary reoperation of 103 days. In univariate statistical analysis, females were more likely to develop a wound complication. However, in stratified analyses excluding patients with an underlying genetic syndrome, increasing age, and lower weight but not gender were associated with wound complications. CONCLUSIONS: A 12.1% (22 of 182) wound complication rate with the use of the Inion CPS Fixation System was observed. Inion plates appear to have an equivalent safety profile to other fixation devices. Increasing age and lower weight were associated with an increased risk of wound complications in nonsyndromic patients.

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BACKGROUND: The CLEFT-Q includes 12 independently functioning scales that measure appearance (face, nose, nostrils, teeth, lips, jaws), health-related quality of life (psychological, social, school, speech distress), and speech function, and an eating/drinking checklist. Previous qualitative research revealed that the CLEFT-Q has content validity in noncleft craniofacial conditions. This study aimed to examine the psychometric performance of the CLEFT-Q in an international sample of patients with a broad range of facial conditions. METHODS: Data were collected between October 2016 and December 2019 from 2132 patients aged 8 to 29 years with noncleft facial conditions. Rasch measurement theory (RMT) analysis was used to examine Differential Item Function (DIF) by comparing the original CLEFT-Q sample and the new FACE-Q craniofacial sample. Reliability and validity of the scales in a combined cleft and craniofacial sample (n=4743) were examined. RESULTS: DIF was found for 23 CLEFT-Q items when the datasets for the two samples were compared. When items with DIF were split by sample, correlations between the original and split person locations showed that DIF had negligible impact on scale scoring (correlations ≥0.995). In the combined sample, RMT analysis led to the retention of original content for ten CLEFT-Q scales, modification of the Teeth scale, and the addition of an Eating/Drinking scale. Data obtained fit with the Rasch model for 11 scales (exception School, p=0.04). Person Separation Index and Cronbach alpha values met the criteria. CONCLUSION: The scales described in this study can be used to measure outcomes in children and young adults with cleft and noncleft craniofacial conditions.

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