Autologous Fat Versus Hydroxyapatite Cement for Use in Frontal Sinus Obliteration: Systematic Review and Meta-Analysis.

BACKGROUND: Frontal sinus obliteration is a possible terminus for the management of chronic sinusitis, frontal bone trauma, cancer extirpation, or mucocele. The mucosa of the sinus is stripped and space obliterated with either autogenic, allopathic, or synthetic materials. This study aimed to compare the outcomes of autologous fat and hydroxyapatite cement (HAC) for frontal sinus obliteration. METHODS: A multidatabase systematic review was conducted to collect outcomes on frontal sinus obliterations with either autologous fat or HAC. Outcomes collected included infection of the frontal sinus or obliteration material, mucocele formation, skin infection at the operative site, hematoma or seroma, cosmetic defect, donor site infection, and need for revision procedure. Prevalence of outcomes was analyzed through meta-analysis of proportions. RESULTS: Twenty studies were ultimately included in the meta-analysis. Sixteen studies reported outcomes for 667 patients obliterated with autologous fat, and 7 studies reported outcomes for 100 patients obliterated with HAC. Prevalence of infection of the frontal sinus or obliteration material, mucocele formation, skin infection at the operative site, hematoma or seroma, and cosmetic defect did not differ statistically between the cohorts. Donor site infection secondary to fat harvesting for fat obliteration had a prevalence of <0.01. Revision rate was 0.04 (95% confidence interval, 0.01-0.8) for fat obliteration and 0.10 (95% confidence interval, 0.00-0.33) for HAC obliteration. CONCLUSIONS: No statistically significant differences in the studied outcomes were detected between obliterations with autologous fat and HAC, suggesting that either is equally suitable and may be up to the surgeon's preference.

SAXS structure of homodimeric oxyHemoglobin III from bivalve Lucina pectinata.

Hemoglobin III (HbIII) is one of the two oxygen reactive hemoproteins present in the bivalve, Lucina pectinata. The clam inhabits a sulfur-rich environment and HbIII is the only hemoprotein present in the system which does not yet have a structure described elsewhere. It is known that HbIII exists as a heterodimer with hemoglobin II (HbII) to generate the stable Oxy(HbII-HbIII) complex but it remains unknown if HbIII can form a homodimeric species. Here, a new chromatographic methodology to separate OxyHbIII from the HbII-HbIII dimer has been developed, employing a fast performance liquid chromatography and ionic exchange chromatography column. The nature of OxyHbIII in solution at concentrations from 1.6 mg/mL to 20.4 mg/mL was studied using small angle X-ray scattering (SAXS). The results show that at all concentrations, the Oxy(HbIII-HbIII) dimer dominates in solution. However, as the concentration increases to nonphysiological values, 20.4 mg/mL, HbIII forms a 30% tetrameric fraction. Thus, there is a direct relationship between the Oxy(HbIII-HbIII) oligomeric form and hemoglobin concentration. We suggest it is likely that the OxyHbIII dimer contributes to active oxygen transport in tissues of L pectinata, where the Oxy(HbII-HbIII) complex is not present.

Normal pediatric prevertebral soft-tissue thickness on MDCT.

OBJECTIVE: The thickness of the prevertebral soft tissue (PVST) is instrumental in helping detect cervical spine injuries in the pediatric population. Current parameters for normal PVST thickness in that population are based on lateral radiographs because there have been no studies to date defining age-dependent normal measurements on MDCT. With the increasingly important role of MDCT in the evaluation of pediatric trauma patients, it is necessary to establish normal values for pediatric PVST thickness on MDCT images. Thus, the purpose of this study is to establish the normal thickness of PVST on MDCT of the pediatric population from 0 to 15 years old. MATERIALS AND METHODS: The thickness of the PVST was measured in 139 pediatric trauma patients (age range 0-15 years) who presented to the pediatric emergency department between 2005 and 2008. Patients included in the study were not intubated, had no congenital or acquired osseous abnormality detected on CT, and were discharged from the hospital without a diagnosis of cervical spine or soft-tissue injury. Exclusion criteria included patients with concurrent injury found on head CT or nontraumatic causes of PVST thickening, such as lymphadenopathy or retropharyngeal internal carotid arteries. Patients who were diagnosed with cervical injuries within 1 year after the initial CT examination were also excluded. Each patient was scanned with a cervical collar placing the cervical spine in a neutral or near-neutral position. RESULTS: The smallest variability and calculated SD were at C2 and C6. The upper limits of normal for PVST thickness at C2 were 7.6 mm in patients from 0 to 2 years old, 8.4 mm in patients from 3 to 6 years old, and 6.8 mm in patients from 7 to 10 years old and in those from 11 to 15 years old. At the C6 level, the upper limits were 9.0 mm in patients from 0 to 2 years old, 9.8 mm in patients from 3 to 6 years old, 12.1 mm in patients from 7 to 10 years old, and 14.5 mm in patients from 11 to 15 years old. The upper limit of normal had the highest variability at C3 and C4 for all age groups. CONCLUSION: The thickness of the PVST is important in the detection of underlying injuries to the cervical spine. MDCT is playing an increasingly important role in the evaluation of pediatric trauma patients. We propose the obtained values as the upper limits of normal for PVST thickness on MDCT images in the pediatric population from 0 to 15 years old.

AMPATH surgical app: Low-cost simulator for the open appendectomy.

BACKGROUND: Due to a shortage and maldistribution of surgeons within Kenya, doctors with limited formal surgical training often perform emergency surgical procedures such as appendectomy. This lack of training can compromise patient outcomes and complicate care delivery. Our aim was to develop a low-cost simulator and skills curriculum to effectively teach open appendectomy. METHODS: Surgeons from 4 countries participated in semi-structured interviews to define the steps and technique of open appendectomy using cognitive task analysis. Using this input, our Academic Model Providing Access to Healthcare surgical team developed a curriculum, including a simulator and feedback mechanism. Surgeons and surgical trainees from Kenya and the United States tested the simulator prototype and provided feedback for its refinement based on clarity, utility, and realism. RESULTS: Instructions for a self-constructed simulator were developed at the cost of 70 Kenyan shillings (0.64 US dollars). Fifteen surgeons and surgical residents gave feedback on the simulator and curriculum, and each was presented with an updated version based on feedback. Overall, the curriculum was clear, with each sub-step receiving a median score of ≥83.5 out of 100 for clarity; however, through iterative design, the utility of sub-steps on the simulator improved. CONCLUSION: A comprehensive open appendectomy curriculum, including a low-cost appendectomy simulator model, was developed and refined using surgeon feedback. Such curricula may benefit trainees in low-resource settings who may otherwise have limited access to quality training material.

Two-step counterdiffusion protocol for the crystallization of haemoglobin II from Lucina pectinata in the pH range 4-9.

Lucina pectinata haemoglobin II (HbII) transports oxygen in the presence of H(2)S to the symbiotic system in this bivalve mollusc. The composition of the haem pocket at the distal site includes TyrB10 and GlnE7, which are very common in other haem proteins. Obtaining crystals of oxyHbII at various pH values is required in order to elucidate the changes in the conformations of TyrB10 and GlnE7 and structural scenarios induced by changes in pH. Here, the growth of crystals of oxyHbII using the capillary counterdiffusion (CCD) technique at various pH values using a two-step protocol is reported. In the first step, a mini-screen was used to validate sodium formate as the best precipitating reagent for the growth of oxyHbII crystals. The second step, a pH screen typically used for optimization, was used to produce crystals in the pH range 4-9. Very well faceted prismatic ruby-red crystals were obtained at all pH values. X-ray data sets were acquired using synchrotron radiation of wavelength 0.886 A (for the crystals obtained at pH 5) and 0.908 A (for those obtained at pH 4, 8 and 9) to maximum resolutions of 3.30, 1.95, 1.85 and 2.00 A for the crystals obtained at pH 4, 5, 8 and 9, respectively. All of the crystals were isomorphous and belonged to space group P4(2)2(1)2.

COVID-19 in children: what did we learn from the first wave?

A pandemic caused by the novel coronavirus, severe acute respiratory syndrome - coronavirus 2 (SARS-CoV-2), has caused high rates of mortality, predominantly in adults. Children are significantly less affected by SARS-CoV-2 with far lower rates of recorded infections in children compared to adults, milder symptoms in the majority of children and very low mortality rates. A suspected late manifestation of the disease, paediatric inflammatory multisystem syndrome - temporally associated with SARS-CoV-2 (PIMS-TS), has been seen in small numbers of children and has a more severe disease course than acute SARS-CoV-2. The pandemic has meant that children around the world have been kept off school, isolated from their extended family and friends and asked to stay inside. The UK has been declared as being in an economic recession and unemployment rates are increasing. These indirect effects of SARS-CoV-2 are likely to have a significant impact on many children for years to come. Consolidating the knowledge that has accumulated during the first wave of this pandemic is essential for recognising the clinical signs, symptoms and effective treatment strategies for children; identifying children who may be at increased risk of severe SARS-CoV-2 infection; planning the safe delivery of healthcare and non-health related services that are important for childrens' wellbeing; and engaging in, and developing, research to address the things that are not yet known. This article summarises the evidence that has emerged from the early phase of the pandemic and offers an overview for those looking after children or planning services.

Crystallization and diffraction patterns of the oxy and cyano forms of the Lucina pectinata haemoglobins complex.

The native oxygen-carrier haemoglobins complex (HbII-III) is composed of haemoglobin II (HbII) and haemoglobin III (HbIII), which are found in the ctenidia tissue of the bivalve mollusc Lucina pectinata. This protein complex was isolated and purified from its natural source and crystallized using the vapour-diffusion and capillary counter-diffusion methods. Oxy and cyano derivatives of the complex crystallized using several conditions, but the best crystals in terms of quality and size were obtained from sodium formate pH 5 using the counter-diffusion method in a single capillary. Crystals of the oxy and cyano complexes, which showed a ruby-red colour and nonsingular prismatic shapes, scattered X-rays to resolution limits of 2.15 and 2.20 A, respectively, using a 0.886 A synchrotron-radiation source. The crystals belonged to the tetragonal system, space group P4(2)2(1)2, with unit-cell parameters a = b = 74.07, c = 152.07 and a = b = 73.83, c = 152.49 A for the oxy and cyano complexes, respectively. The asymmetric unit of both crystals is composed of a single copy of the heterodimer, with Matthew coefficients (V(M)) of 3.08 and 3.06 A(3) Da(-1) for the oxy and cyano complexes, respectively, which correspond to a solvent content of approximately 60.0% by volume.

Neuromyelitis optica in child: diagnostic and therapeutic challenges.

Neuromyelitis optica (NMO) is a rare syndrome of severe inflammatory demyelination of the central nervous system, causing attacks of optic neuritis and transverse myelitis. Although uncommon, attention should be given to the proper identification and management of the affected patients. We present a case of a 13-year-old girl with severe neuromyelitis optica. The patient's initial presentation consisted of encephalopathy and optic neuritis. Approximately 2 months later, coinciding with the weaning of steroid treatment, she presented with ascending paralysis and respiratory failure. She was seropositive for NMO-IgG. Treatment included intravenous immune globulin, steroids, plasmapheresis, and rituximab and was complemented with proper nutrition, vitamins, minerals, and intense rehabilitation. Two years after the initial presentation and one short relapse, the patient has made a remarkable recovery without neurologic deficit. This report underscores the difficulty in making the initial diagnosis, choosing the best treatment, and the need for more streamlined pediatric guidelines for diagnosis, treatment, and prevention of relapses of pediatric NMO.

Movement of abdominal structures on magnetic resonance imaging during positioning changes related to lateral lumbar spine surgery: a morphometric study: Clinical article.

OBJECT: The minimally invasive lateral interbody fusion of the lumbar spine through a retroperitoneal transpsoas approach has become increasingly used. Although preoperative imaging is performed supine, the procedure is performed with the patient in the lateral decubitus position. The authors measured the changes in location of the psoas muscle, aorta, inferior vena cava (IVC), iliac vessels, and kidneys with regard to the fixed lumbar spine when moving from a supine to a lateral decubitus position. METHODS: Unenhanced lumbar MRI scans were performed using a 3T magnet in 10 skeletally mature volunteers in the supine, left lateral decubitus (LLD), and right lateral decubitus (RLD) positions. Positional changes in the aorta, IVC, iliac vessels, and kidneys were then analyzed at all lumbar levels when moving from supine to RLD and supine to LLD. Values are presented as group means. RESULTS: When the position was changed from supine to RLD, both the aorta and the IVC moved up to 6 mm to the right, with increased movement caudally at L3-4. The aorta was displaced 2 mm anteriorly at L1-2, and the IVC moved 3 mm anteriorly at L1-2 and L2-3 and 1 mm posteriorly at L3-4. The left kidney moved 22 mm anteriorly and 15 mm caudally, while the right kidney moved 9 mm rostrally. When the position was changed from supine to LLD, the aorta moved 1.5 mm to the left at all levels, with very minimal anterior/posterior displacement. The IVC moved up to 10 mm to the left and 12 mm anteriorly, with increased movement rostrally at L1-2. The left kidney moved 3 mm anteriorly and 1 mm rostrally, while the right kidney moved 20 mm anteriorly and 5 mm caudally. The bifurcation of the aorta was an average of 18 mm above the L4-5 disc space, while the convergence of the iliac veins to form the IVC was at the level of the disc space. The iliopsoas did not move in any quantifiable direction when the position was changed from supine to lateral; its shape, however, may change to become more flat or rounded. When the position was changed from supine to RLD, the right iliac vein moved posteriorly an average of 1.5 mm behind the anterior vertebral body (VB) line (a horizontal line drawn on an axial image at the anterior VB), while the other vessels stayed predominantly anterior to the disc space. When the position was changed from supine to LLD, the right iliac vein moved to a position 1.4 mm anterior to the anterior VB line. There was negligible movement of the other vessels in this position. CONCLUSIONS: The authors showed that the aorta, IVC, and kidneys moved a significant distance away from the surgical corridor with changes in position. At the L4-5 level, a left-sided approach may be riskier because the right common iliac vein trends posteriorly and into the surgical corridor, whereas in a right-sided approach it trends anteriorly.