Population analysis of predictors of difficult intubation with direct laryngoscopy in pediatric patients with and without thyroid disease.

PURPOSE: There are no data on the prevalence and predictors of difficult intubation (DI) in pediatric patients with thyroid disease. This study (1) assesses the prevalence of DI in patients with thyroid disease undergoing elective operations, (2) identifies other predictors of DI in children, and (3) evaluates the effect of DI on postoperative care and length-of-stay. METHODS: A single-center retrospective cohort analysis of procedures in patients assigned with an ICD-9 code for thyroid disease between June 2012 and February 2016. A comparative group was created which comprised of patients without thyroid disease receiving orthopedic or urologic surgeries to determine differences in DI prevalence. Univariate analyses compared demographics and intubation details between groups, and logistic regression identified independent variables associated with DI. Patients with and without DI were compared based on procedure duration, PACU-LOS, and escalation-of-care. RESULTS: DI prevalence was greater in the thyroid group (4.9%, 51/1046) compared to the non-thyroid group (2.6%, 33/1289) (OR 1.95, 95% CI 1.25-3.05; p = 0.003). DI was associated with younger age, higher American Society of Anesthesiologists (ASA) class, and smaller body habitus (p < 0.001 for all comparisons). Congenital hypothyroidism (OR 2.49, 95% CI 1.44-4.32; p = 0.002)) and acquired hypothyroidism (OR 2.20, 95% CI 1.42-3.41; p < 0.001) were seen in a greater proportion of DI patients. After adjustment for demographic confounders, age and ASA class were independently associated with DI (p < 0.05), while hypothyroidism did not reach statistical significance (p = 0.077). Direct laryngoscopy (DL) was most frequently used as the successful subsequent maneuver in securing the airway in DI patients. A longer PACU length-of-stay was seen after procedures with DI (p < 0.001). CONCLUSION: Elective pediatric surgical patients with thyroid-related diagnoses at our institution had a higher prevalence of DI than those without thyroid disease, but this finding could not be isolated to thyroid pathology. Repeat DL achieves successful intubation in the majority of DI patients. DI patients often require longer recovery times due to prolonged cardiopulmonary monitoring.

Induction of a stringent metabolic response in intracellular stages of Leishmania mexicana leads to increased dependence on mitochondrial metabolism.

Leishmania parasites alternate between extracellular promastigote stages in the insect vector and an obligate intracellular amastigote stage that proliferates within the phagolysosomal compartment of macrophages in the mammalian host. Most enzymes involved in Leishmania central carbon metabolism are constitutively expressed and stage-specific changes in energy metabolism remain poorly defined. Using (13)C-stable isotope resolved metabolomics and (2)H2O labelling, we show that amastigote differentiation is associated with reduction in growth rate and induction of a distinct stringent metabolic state. This state is characterized by a global decrease in the uptake and utilization of glucose and amino acids, a reduced secretion of organic acids and increased fatty acid ß-oxidation. Isotopomer analysis showed that catabolism of hexose and fatty acids provide C4 dicarboxylic acids (succinate/malate) and acetyl-CoA for the synthesis of glutamate via a compartmentalized mitochondrial tricarboxylic acid (TCA) cycle. In vitro cultivated and intracellular amastigotes are acutely sensitive to inhibitors of mitochondrial aconitase and glutamine synthetase, indicating that these anabolic pathways are essential for intracellular growth and virulence. Lesion-derived amastigotes exhibit a similar metabolism to in vitro differentiated amastigotes, indicating that this stringent response is coupled to differentiation signals rather than exogenous nutrient levels. Induction of a stringent metabolic response may facilitate amastigote survival in a nutrient-poor intracellular niche and underlie the increased dependence of this stage on hexose and mitochondrial metabolism.

Outcomes in organ transplants from donors with melanoma: a systematic review.

Melanoma transmitted through organ transplantation is an increasingly reported event. Immunosuppression increases the risk of melanoma; however, transmission of malignancy from transplanted organs is a distinct etiology of melanoma occurrence. The risk of transmission of melanoma from an organ donor with melanoma has yet to be determined. The authors aimed to investigate this phenomenon by reviewing the outcomes of patients that received organs from donors with melanoma. A systematic literature review was conducted with emphasis on identifying organ donors with known histories of melanoma and reported information regarding recipients of their organs. The databases PubMed, MEDLINE, Embase, and JBI EBP were searched in January 2023. Search terms included "melanoma," terms for solid organs, "donor," "transplant," "transmission," and their variations as well as terms related to temporal relations. Inclusion criteria were articles that stated outcomes in organ recipients from donors that had a diagnosis of melanoma either pretransplant or postmortem. Reference lists of selected articles were hand searched for further studies. A total of 232 articles were identified from the search parameters. After applying inclusion and exclusion criteria, 13 articles were selected. Hand searching the references of these articles yielded four additional articles. Of the 75 organ recipients that received organs from donors with known melanoma, 43 developed melanoma. While a definitive quantitative risk cannot be ascertained based on our review, the numerous reported cases of melanoma in organ recipients from donors that have melanoma should still be considered by clinicians.

Isotopomer profiling of Leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth.

Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various (13)C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and (13)C NMR. [U-(13)C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD(+) consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-(13)C]aspartate and [U-(13)C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.

Effective bias removal for fringe projection profilometry using the dual-tree complex wavelet transform.

When reconstructing the three-dimensional (3D) object height profile using the fringe projection profilometry (FPP) technique, the light intensity reflected from the object surface can yield abruptly changing bias in the captured fringe image, which leads to severe reconstruction error. The traditional approach tries to remove the bias by suppressing the zero spectrum of the fringe image. It is based on the assumption that the aliasing between the frequency spectrum of the bias, which is around the zero frequency, and the frequency spectrum of the fringe is negligible. This, however, is not the case in practice. In this paper, we propose a novel (to our knowledge) technique to eliminate the bias in the fringe image using the dual-tree complex wavelet transform (DT-CWT). The new approach successfully identifies the features of bias, fringe, and noise in the DT-CWT domain, which allows the bias to be effectively extracted from a noisy fringe image. Experimental results show that the proposed algorithm is superior to the traditional methods and facilitates accurate reconstruction of objects' 3D models.

Laser-Assisted Drug Delivery: A Systematic Review of Safety and Adverse Events.

Laser-assisted drug delivery (LADD) is an increasingly studied and applied methodology for drug delivery. It has been used in a wide variety of clinical applications. Given the relatively low barrier to entry for clinicians as well as ongoing research in this area, the authors aimed to review outcomes relating to safety in laser-assisted drug delivery. A systematic review was conducted, with the databases PubMed, Medline and Embase searched in September 2022. Included articles were those that mentioned laser-assisted drug delivery in human subjects that also reported adverse effects or safety outcomes. There were no language-based exclusions. Conference abstracts and literature reviews were excluded. The results were then tabulated and categorized according to the application of LADD. In total, 501 articles were obtained. Following deduplication, screening, and full text review 70 articles of various study designs were included. Common findings were erythema, oedema, pain, and crusting following LADD. Several notably more severe adverse effects such as generalized urticaria, infection, scarring and dyspigmentation were noted. However, these events were varied depending on the clinical use of LADD. Relevant negatives were also noted whereby no studies reported life-threatening adverse effects. Limitations included limited details regarding the adverse effects within the full texts, lack of follow-up, and risk of bias. In conclusion, there were multiple adverse effects that clinicians should consider prior to carrying out LADD, where treatment goals and patient tolerability should be considered. Further evidence is needed to quantitatively determine these risks.

Hidradenitis suppurativa and association with stroke: systematic review and meta-analysis.

PURPOSE: Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful nodules, abscesses, sinus tract formation and scarring. The relationship between HS and strokes is not well established. To assess this potential association, a systematic review and meta-analysis was performed according to PRISMA guidelines. MATERIALS AND METHODS: Electronic searches were performed from six online databases. All eligible case-control studies comparing patients with HS versus non-HS were included. All studies must have included either the proportion of patients with strokes (identified via ICD-9 or ICD-10 codes) in each group, or the summary effect size for association between HS and strokes. Odds ratio (OR) with 95% confidence interval (CI) was used as the effect size. RESULTS: Through our search, we identified six case-control studies for inclusion. From pooled data, we found a significantly higher proportion of strokes in HS cases compared with controls (OR 1.74, 95% CI 1.45-2.09; p < .00001). Limitations included those studies reviewed were observational by design which are susceptible to bias and lack of randomization. CONCLUSION: Our pooled findings demonstrate that the odds of stroke are increased in patients with HS when compared with controls. Dermatologists and other clinicians should be vigilant cerebrovascular risk assessment and risk mitigation in patients with HS.

Standardized, defined serum-free culture of a human skin equivalent on fibroblast-populated collagen scaffold.

The defined, serum-free media used in the cultivation of skin equivalents are liable to inter-laboratory variations, require the preparation of multiple additives, and are potentially difficult to replicate. In this study, we assessed the use of standardized, serum-free and bovine pituitary extract-free keratinocyte culture media in the development of a human skin equivalent. After culture at the air-liquid interface for 3 weeks on a fibroblast-populated collagen lattice, an orthokeratinized, pluristratified epithelium was produced which expressed cytokeratins, cornified cell envelope precursors (involucrin, transglutaminase 1, filaggrin) and desmosomal components (desmoglein and desmocollin 1 and 3, plakophilin 1) in a differentiation-specific manner. There was also evidence of basement membrane reconstitution with collagen IV/VII, laminin 5, α6 and ß4 integrin subunit expression at the epithelial-matrix junction. Overall, our findings demonstrate that readily available, defined organotypic culture media can be used to generate a reproducible skin equivalent with hallmarks of epidermal differentiation.

Efficient fringe image enhancement based on dual-tree complex wavelet transform.

In optical phase shift profilometry (PSP), parallel fringe patterns are projected onto an object and the deformed fringes are captured using a digital camera. It is of particular interest in real time three-dimensional (3D) modeling applications because it enables 3D reconstruction using just a few image captures. When using this approach in a real life environment, however, the noise in the captured images can greatly affect the quality of the reconstructed 3D model. In this paper, a new image enhancement algorithm based on the oriented two-dimenional dual-tree complex wavelet transform (DT-CWT) is proposed for denoising the captured fringe images. The proposed algorithm makes use of the special analytic property of DT-CWT to obtain a sparse representation of the fringe image. Based on the sparse representation, a new iterative regularization procedure is applied for enhancing the noisy fringe image. The new approach introduces an additional preprocessing step to improve the initial guess of the iterative algorithm. Compared with the traditional image enhancement techniques, the proposed algorithm achieves a further improvement of 7.2 dB on average in the signal-to-noise ratio (SNR). When applying the proposed algorithm to optical PSP, the new approach enables the reconstruction of 3D models with improved accuracy from 6 to 20 dB in the SNR over the traditional approaches if the fringe images are noisy.

Development, manufacturing, and preliminary validation of a reusable half-face respirator during the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.

In vitro studies of DNA damage caused by tricyclic antidepressants: a role of peroxidase in the side effects of the drugs.

Studies show that tricyclic antidepressants prescribed for migraines, anxiety, and child enuresis have numerous adverse effects in living cells. One of the undesired outcomes observed under treatment with these drugs is DNA damage. However, the mechanisms underlying damage have yet to be elucidated. We performed in vitro studies of the DNA damage caused by four tricyclic antidepressants: imipramine, amitriptyline, opipramol, and protriptyline. We focused particularly on the DNA damage aided by peroxidases. As a model of a peroxidase, we used horseradish peroxidase (HRP). At pH 7, reactions of HRP with excess hydrogen peroxide and imipramine yielded an intense purple color and a broad absorption spectrum with the maximum intensity at 522 nm. Reactions performed between DNA and imipramine in the presence of H(2)O(2) and HRP resulted in the disappearance of the DNA band. In the case of the other three drugs, this effect was not observed. Extraction of the DNA from the reaction mixture indicated that DNA is degraded in the reaction between imipramine and H(2)O(2) catalyzed by HRP. The final product of imipramine oxidation was identified as iminodibenzyl. We hypothesize that the damage to DNA was caused by an imipramine reactive intermediate.

A Method for Rapid Selection of Randomly Induced Mutations in a Gene of Interest Using CRISPR/Cas9 Mediated Activation of Gene Expression.

We have developed a CRISPR/Cas9 based method for isolating randomly induced recessive lethal mutations in a gene of interest (GOI) by selection within the F1 progeny of a single genetic cross. Our method takes advantage of the ability to overexpress a GOI using CRISPR/Cas9 mediated activation of gene expression. In essence, the screening strategy is based upon the idea that if overexpression of a wild type allele can generate a phenotype, then overexpression of a newly induced loss-of-function allele will lack this phenotype. As a proof-of-principle, we used this method to select EMS induced mutations of the Drosophila gene hindsight (hnt). From approximately 45,000 F1 progeny we recovered 8 new EMS induced loss-of-function hnt alleles that we characterized as an allelic series of hypomorphic mutations. This new method can, in theory, be used to recover randomly induced point mutants in a GOI and can be applied to any circumstance where CRISPR/Cas9 mediated activation of gene expression is associated with lethality or a visible phenotype.

Personalized Ventilation to Multiple Patients Using a Single Ventilator: Description and Proof of Concept.

OBJECTIVES: To design and test a ventilator circuit that can be used for ventilation of two or more patients with a single ventilator, while allowing individualization of tidal volume, fractional concentration of oxygen, and positive end-expiratory pressure to each patient, irrespective of the other patient's respiratory system mechanics. DESIGN: Description and proof of concept studies. SETTINGS: Respiratory therapy laboratory. SUBJECTS: Ventilation of mechanical test lungs. INTERVENTIONS: Following a previously advocated design, we used components readily available in our hospital to assemble two "bag-in-a-box" breathing circuits. Each patient circuit consisted of a flexible bag in a rigid container connected via one-way valve to a test lung, along with an inline positive end-expiratory pressure valve, connected to the ventilator's expiratory limb. Compressed gas fills the bags during "patient" exhalation. During inspiration, gas from the ventilator, in pressure control mode, enters the containers and displaces gas from the bags to the test lungs. We varied tidal volume, "respiratory system" compliance, and positive end-expiratory pressure in one lung and observed the effect on the tidal volume of the other. MEASUREMENTS AND MAIN RESULTS: We were able to obtain different tidal volume, dynamic driving pressure, and positive end-expiratory pressure in the two lungs under widely different compliances in both lungs. Complete obstruction, or disconnection at the circuit connection to one test lung, had minimal effect (< 5% on average) on the ventilation to the co-ventilated lung. CONCLUSIONS: A secondary circuit "bag-in-the-box" system enables individualized ventilation of two lungs overcoming many of the concerns of ventilating more than one patient with a single ventilator.

Subject validation of reusable N95 stop-gap filtering facepiece respirators in COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic has unveiled widespread shortages of personal protective equipment including N95 respirators. Several centers are developing reusable stop-gap respirators as alternatives to disposable N95 respirators during public health emergencies, using techniques such as 3D-printing, silicone moulding and plastic extrusion. Effective sealing of the mask, combined with respiratory filters should achieve 95% or greater filtration of particles less than 1um. Quantitative fit-testing (QNFT) data from these stop-gap devices has not been published to date. Our team developed one such device, the "SSM", and evaluated it using QNFT. METHODS: Device prototypes were iteratively evaluated for comfort, breathability and communication, by team members wearing them for 15-30min. The fit and seal were assessed by positive and negative pressure user seal checks. The final design was then formally tested by QNFT, according to CSA standard Z94.4-18 in 40 volunteer healthcare providers. An overall fit-factor >100 is the passing threshold. Volunteers were also tested by QNFT on disposable N95 masks which had passed qualitative fit testing (QLFT) by institutional Occupational Health and Safety Department. RESULTS: The SSM scored 3.5/5 and 4/5 for comfort and breathability. The median overall harmonic mean fit-factors of disposable N95 and SSM were 137.9 and 6316.7 respectively. SSM scored significantly higher than disposable respirators in fit-test runs and overall fit-factors (p <0.0001). Overall passing rates in disposable and SSM respirators on QNFT were 65% and 100%. During dynamic runs, passing rates in disposable and SSM respirators were 68.1% and 99.4%; harmonic means were 73.7 and 1643. CONCLUSIONS: We present the design and validation of a reusable N95 stop-gap filtering facepiece respirator that can match existent commercial respirators. This sets a precedence for adoption of novel stop-gap N95 respirators in emergency situations.

Human umbilical cord epithelial cells express Notch1: implications for its epidermal-like differentiation.

BACKGROUND: Notch1 receptor, a member of the Notch signaling pathway, is involved in the terminal differentiation process of epidermal keratinocytes. Human umbilical cord epithelia are continuous with embryonic and fetal epidermis during development, display cellular stratification and express differentiation markers related to the epidermis. As such, we hypothesized that Notch1 may be present in human umbilical cord epithelial cells (HUCEC). OBJECTIVE: To investigate the expression of Notch1 in HUCEC in vivo and in vitro. METHODS: Umbilical cord sections were probed with antibodies specific for Notch1, -2, -3, and -4. Expression of Notch transcripts in HUCEC in vitro was examined by RT-PCR analysis and protein expression was identified using immunocytochemistry and western blotting analysis. Using a three-dimensional organotypic culture system that promotes epidermal terminal differentiation, Notch1 expression was examined and changes in expression level were analysed using real-time quantitative PCR. RESULTS: Immunostaining of cord epithelia revealed expression of all four Notch receptors, with differential spatial distribution. Notch mRNA and protein were expressed in HUCEC in vitro. Specifically, western blotting revealed the presence of the transmembrane unit of the mature Notch1 heterodimeric receptor in HUCEC and epidermal keratinocytes. In organotypic culture, Notch1 mRNA was expressed in HUCEC with protein localised to the upper epithelial layers. Interestingly, Notch1 gene expression was down-regulated in HUCEC in organotypic culture compared to cells in submerged monolayer culture. CONCLUSION: HUCEC express Notch1 as in epidermal keratinocytes. The presence of Notch1 has implications for its involvement in the differentiation program of cord epithelia as a stratified epithelial tissue.

Success of rechallenging dabrafenib and trametinib combination therapy after trametinib-induced rhabdomyolysis: a case report.

The mitogen-activated protein kinase pathway regulates cell growth and differentiation and is activated by BRAF mutations. BRAF mutations are present in about 40-50% of cutaneous melanomas. More than 90% of BRAF mutations are the V600E type. BRAF inhibitor (dabrafenib or vemurafenib) and MEK inhibitor (trametinib or cobimetinib) combination therapies are effective for BRAF-mutant advanced melanomas. A variety of side effects have been observed with combination therapy including pyrexia, fatigue, nausea, and vomiting. Rhabdomyolysis is one of the most severe adverse events, but it is very rare. Only two cases of rhabdomyolysis have been reported in clinical trials. A 41-year-old Japanese woman with cutaneous melanoma was started on a combination of dabrafenib and trametinib therapy after failure of immune checkpoint therapy. One month later, she complained of myalgia and fatigue and was shifted to our hospital. She was diagnosed with trametinib-induced rhabdomyolysis and showed improvement only with a high volume of fluid infusion. We stopped combination therapy, but there were no useful treatment options for her. After resuming dabrafenib, followed by trametinib, she did not have any problems. This is the first case of a patient with metastatic cutaneous melanoma who could recommence combination therapy after trametinib-associated rhabdomyolysis. We assume that not all patients experience recurrence of rhabdomyolysis in trametinib-induced rhabdomyolysis. As few cases have been reported, more information is needed. We have to evaluate safety carefully if rechallenging combination therapy.

Automated multiple ligand screening by frontal affinity chromatography-mass spectrometry (FAC-MS).

High-throughput screening (HTS) efforts to discover "hits" typically rely on the large-scale parallel screening of individual compounds with attempts to screen mixtures of compounds typically and, unfortunately, giving rise to false positives and false negatives due to the nature of the HTS readout (% inhibition/activation above a defined threshold) that makes deconvolution virtually intractable. Bioaffinity screening methods have emerged as an alternative or orthogonal method to classic HTS. One of these methods, frontal affinity chromatography coupled to mass spectrometry detection (FAC-MS), although still a relatively new technique, is turning out to be a viable screening tool. However, to push FAC-MS more to the forefront as a moderate primary HTS system (or a secondary screening assay), automation needs to be addressed. An automated FAC-MS system is described using 2 columns containing immobilized hERbeta, whereby while 1 column is being regenerated, the other is being used. The authors are extrapolating that in a continuous 24-h operation, the number of ligands screened could potentially approach 10,000. In addition, preliminary structure-activity relationship binding information (typically not seen in early primary HTS) can be obtained by observing the rank order of the library members in the various mixtures.