An Open-Source Three-Dimensionally Printed Laryngeal Model for Injection Laryngoplasty Training

OBJECTIVES/HYPOTHESIS

A limited number of three-dimensionally (3D)-printed laryngeal simulators have been described in the literature, only one of which is specifically designed for percutaneous injection laryngoplasty (PIL) training and is currently of limited availability. This study describes the development and evaluation of a high-fidelity, open-source, low-cost 3D-printed simulator for PIL training, improving on existing models.

STUDY DESIGN

Simulator design and survey evaluation.

METHODS

Computed tomography scans of the upper airways were processed with 3D Slicer to generate a computer model of the endolarynx. Blender and Fusion 360 were used to refine the mucosal model and develop casts for silicone injection molding. The casted endolaryngeal structures were inserted into a modified version of a publicly available laryngeal cartilage model. The final models were evaluated by 10 expert laryngologists using a customized version of the Michigan Standard Simulation Experience Scale. Internal consistency and interrater reliability of the survey were evaluated using Cronbach's α and intraclass correlation, respectively.

RESULTS

Expert laryngologists highly rated the model for measures of fidelity, educational value, and overall quality (mean = 4.8, standard deviation = 0.5; 1 = strongly disagree, 5 = strongly agree). All reviewers rated the model as ready for use as is or with slight modifications. The filament needed for one cartilage model costs $0.96, whereas the silicone needed for one soft-tissue model costs $1.89.

CONCLUSIONS

Using 3D-printing technology, we successfully created the first open-source, low-cost, and anatomically accurate laryngeal model for injection laryngoplasty training. Our simulator is made freely available for download on Wikifactory with step-by-step tutorials for 3D printing, silicone molding, assembly, and use.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E890-E895, 2021.

Genome-wide cell-free DNA mutational integration enables ultra-sensitive cancer monitoring

In many areas of oncology, we lack sensitive tools to track low-burden disease. Although cell-free DNA (cfDNA) shows promise in detecting cancer mutations, we found that the combination of low tumor fraction (TF) and limited number of DNA fragments restricts low-disease-burden monitoring through the prevailing deep targeted sequencing paradigm. We reasoned that breadth may supplant depth of sequencing to overcome the barrier of cfDNA abundance. Whole-genome sequencing (WGS) of cfDNA allowed ultra-sensitive detection, capitalizing on the cumulative signal of thousands of somatic mutations observed in solid malignancies, with TF detection sensitivity as low as 10-5. The WGS approach enabled dynamic tumor burden tracking and postoperative residual disease detection, associated with adverse outcome. Thus, we present an orthogonal framework for cfDNA cancer monitoring via genome-wide mutational integration, enabling ultra-sensitive detection, overcoming the limitation of cfDNA abundance and empowering treatment optimization in low-disease-burden oncology care.

DNA methylation disruption reshapes the hematopoietic differentiation landscape

Mutations in genes involved in DNA methylation (DNAme; for example, TET2 and DNMT3A) are frequently observed in hematological malignancies1-3 and clonal hematopoiesis4,5. Applying single-cell sequencing to murine hematopoietic stem and progenitor cells, we observed that these mutations disrupt hematopoietic differentiation, causing opposite shifts in the frequencies of erythroid versus myelomonocytic progenitors following Tet2 or Dnmt3a loss. Notably, these shifts trace back to transcriptional priming skews in uncommitted hematopoietic stem cells. To reconcile genome-wide DNAme changes with specific erythroid versus myelomonocytic skews, we provide evidence in support of differential sensitivity of transcription factors due to biases in CpG enrichment in their binding motif. Single-cell transcriptomes with targeted genotyping showed similar skews in transcriptional priming of DNMT3A-mutated human clonal hematopoiesis bone marrow progenitors. These data show that DNAme shapes the topography of hematopoietic differentiation, and support a model in which genome-wide methylation changes are transduced to differentiation skews through biases in CpG enrichment of the transcription factor binding motif.

Somatic mutations and cell identity linked by Genotyping of Transcriptomes

Defining the transcriptomic identity of malignant cells is challenging in the absence of surface markers that distinguish cancer clones from one another, or from admixed non-neoplastic cells. To address this challenge, here we developed Genotyping of Transcriptomes (GoT), a method to integrate genotyping with high-throughput droplet-based single-cell RNA sequencing. We apply GoT to profile 38,290 CD34+ cells from patients with CALR-mutated myeloproliferative neoplasms to study how somatic mutations corrupt the complex process of human haematopoiesis. High-resolution mapping of malignant versus normal haematopoietic progenitors revealed an increasing fitness advantage with myeloid differentiation of cells with mutated CALR. We identified the unfolded protein response as a predominant outcome of CALR mutations, with a considerable dependency on cell identity, as well as upregulation of the NF-κB pathway specifically in uncommitted stem cells. We further extended the GoT toolkit to genotype multiple targets and loci that are distant from transcript ends. Together, these findings reveal that the transcriptional output of somatic mutations in myeloproliferative neoplasms is dependent on the native cell identity.

Capecitabine-induced cardiotoxicity: case report and review of the literature

Capecitabine, an oral prodrug of 5-fluorouracil (5fu), has been integrated into the management of multiple cancer types because of convenience of administration and efficacy comparable with 5fu. Cardiotoxicity induced by 5fu—in particular angina—has been well described in the literature, but reports of adverse cardiac events with capecitabine are also emerging. The mechanism underlying 5fu cardiotoxicity has long been thought to result from coronary vasospasm, but animal-model studies and patient echocardiographic findings both suggest a cardiomyopathic picture. Although 5fu cardiotoxicity is often reversible and can be managed supportively, presentations that are more severe—including arrhythmias, acute ischemic events, and cardiogenic shock—have been documented. In this report, we describe the case of a patient who ultimately required a pacemaker after developing symptomatic bradycardia and sinus arrest while receiving capecitabine for colon cancer.

Modification to reporting of qualitative fluorescent spot test results improves detection of glucose-6-phosphate dehydrogenase (G6PD)-deficient heterozygote female newborns

INTRODUCTION

The glucose-6-phosphate dehydrogenase (G6PD) fluorescent spot test (FST) is a useful screening test for G6PD deficiency, but is unable to detect heterozygote G6PD-deficient females. We sought to identify whether reporting intermediate fluorescence in addition to absent and bright fluorescence on FST would improve identification of mildly deficient female heterozygotes.

METHODS

A total of 1266 cord blood samples (705 male, 561 female) were screened for G6PD deficiency using FST (in-house method) and a quantitative enzyme assay. Fluorescence intensity of the FST was graded as either absent, intermediate or normal. Samples identified as showing absent or intermediate fluorescence on FST were analysed for the presence of G6PD mutations using TaqMan@SNP genotyping assays and direct nucleotide sequencing.

RESULTS

Of the 1266 samples, 87 samples were found to be intermediate or deficient by FST (49 deficient, 38 intermediate). Of the 49 deficient samples, 48 had G6PD enzyme activity of ≤ 9.5 U/g Hb and one sample had normal enzyme activity. All 38 intermediate samples were from females. Of these, 21 had G6PD activity of between 20% and 60%, and 17 samples showed normal G6PD activity. Twenty-seven of the 38 samples were available for mutation analysis of which 13 had normal G6PD activity. Eleven of the 13 samples with normal G6PD activity had identifiable G6PD mutations.

CONCLUSION

Glucose-6-phosphate dehydrogenase heterozygote females cannot be identified by FST if fluorescence is reported as absent or present. Distinguishing samples with intermediate fluorescence from absent and bright fluorescence improves detection of heterozygote females with mild G6PD deficiency. Mutational studies confirmed that 85% of intermediate samples with normal enzyme activity had identifiable G6PD mutations.

Histological recurrence and depth of loop treatment of the cervix in women of reproductive age: incomplete excision versus adverse pregnancy outcome

OBJECTIVE

Recent meta-analyses have shown that loop treatment of the cervix of > 10 mm depth may be associated with adverse outcomes in future pregnancies. The aim of this study is to assess the rate of incomplete excision and recurrent disease in relation to depth of excision in women of reproductive age undergoing loop treatment.

DESIGN

Observational cohort study.

SETTING

Colposcopy Clinic, Northern Gynaecological Oncology Centre, Gateshead, UK.

POPULATION

In all, 1558 women undergoing loop treatment for high-grade cervical intraepithelial neoplasia (HGCIN) between 1998 and 2003.

METHODS

Women were followed up until 2008. Recurrence was analysed using Kaplan-Meier plots.

OUTCOME MEASURES

Incomplete excision rates and recurrence rates. Recurrence was defined as post-treatment disease with high-grade histology. Any dyskaryotic cytology on follow-up was also documented.

RESULTS

Recurrent high-grade disease on histology was found in 57/1558 (3.7%) women. In women ≤ 35 years old, despite a greater rate of incomplete excision at the endocervical margin at loop depths < 10 mm compared with ≥ 10 mm (24.4% versus 13.3%, P < 0.01), the recurrence rate was similar between the two groups (4.3% versus 3.4%, log-rank, P = 0.52). In contrast, a loop depth < 10 mm was associated with a higher disease recurrence rate (7.5% versus 3.0%, log-rank, P = 0.05) in women > 35 years.

CONCLUSION

In women of reproductive age requiring treatment for HGCIN, colposcopists performing loop excision should aim for < 10 mm depth. This provides adequate treatment for HGCIN and minimises the potential risk of adverse outcomes in future pregnancies.

The role of the endocannabinoid system in gametogenesis, implantation and early pregnancy

Maternal use of marijuana, in which the exocannabinoid Delta(9)-tetrahydrocannabinol is the most active psychoactive ingredient, is known to have adverse effects on various aspects of reproduction including ovulation, spermatogenesis, implantation and pregnancy duration. Endogenous cannabinoids of which Anandamide is the prototype are widely distributed in the body especially in the reproductive tract and pregnancy tissues and act through the same receptors as the receptor as Delta(9)-tetrahydrocannabinol. Anandamide, has been reported to have pleiotropic effects on human reproduction and in experimental animal models. It appears to be the important neuro-cytokine mediator synchronizing the embryo-endometrial development for timed implantation, the development of the embryo into the blastocyst and transport of the embryo across the fallopian tubes. The mechanisms by which it exerts these effects are unclear but could be via direct actions on the various sites within the reproductive system or its differential actions on vascular tone dependent. In this review article we bring together the current knowledge on the role of endoccanabinoids in reproduction and postulate on the potential mechanisms on how these affect reproduction. In addition, we examine its role on the endothelium and vascular smooth muscle as a potential mechanism for adverse pregnancy outcome.

Clinicopathologic features and prognostic implications of epidermal growth factor receptor (EGFR) gene mutations detected by denaturing high-performance liquid chromatography (dHPLC) in non-small cell lung cancer (NSCLC)

7594

Background: Somatic mutations of the EGFR gene predict sensitivity to erlotinib and gefitinib and confer a favorable prognosis in patients (pts) with NSCLC. We have recently shown that dHPLC is an efficient and more sensitive method for mutation screening compared with DNA sequencing. The goal of this study was to describe the relationship between EGFR status (mutation status and type) and clinicopathologic factors. Methods: Tumor samples were analysed for EGFR exon 19 deletions and exon 21 L858R point mutations. DNA was extracted from paraffin-embedded tumor specimens and genotyped using dHPLC. The results were correlated with gender, smoking status, pathologic subtype, disease stage, and overall survival. Results: 215 NSCLC pts were genotyped. Mutations were present in 25% of cases (54 of 215). Among pts with mutations, 70% (38 of 54) had an exon 19 mutation whereas 30% had EGFR L858R. EGFR mutations were more common in women (31% vs 14%; p=0.008), in nonsmokers than ever-smokers (54% vs 17%; p<0.001), in adenocarcinomas/BAC than with other NSCLC histologies (31% vs 11%; p=0.004) and more frequently detected in advanced-stage than in early-stage disease (36% vs 15%; p=0.001). Median survival times of pts with stage IIIB-IV disease with and without EGFR mutations were 20 and 14 months, respectively. Those with exon 19 deletion mutations had a longer median survival than pts with L858R point mutations. Data describing the impact of tyrosine kinase inhibitor therapy on survival outcomes are pending and will be presented. Conclusion: dHPLC is a reliable tool for EGFR mutation detection. Mutations were preferentially observed in women, nonsmokers, adenocarcinomas/BAC and in patients with advanced disease. Pts with mutations experienced improved survival and those harboring deletions fared better than those with point mutations. These observations warrant confirmation in large prospective trials and exploration of the biological mechanisms of the differences between mutation types.

No significant financial relationships to disclose.

Diabetes and the maternal resistance vasculature

Diabetes is the most common endocrine disorder worldwide, with complications that include the development of both macro- and micro-vascular disease that contribute significantly to patient morbidity and mortality. The severity of diabetic complications is amplified during pregnancy, resulting in a higher incidence of adverse pregnancy outcomes such as pre-eclampsia, placental insufficiency and stillbirth than in non-diabetics. Vascular dysfunction is thought to underlie many of these complications, with the greatest impact occurring at the level of the resistance vasculature, where alterations in vascular reactivity can significantly affect blood flow and tissue perfusion. It is likely that problems associated with diabetic pregnancies are related, in part, to abnormal vascular function, particularly dysfunction of the vascular endothelium.

The effect of type 1 diabetes mellitus on vascular responses to endothelin-1 in pregnant women

Diabetes is associated with vascular dysfunction, which may be due in part to altered vascular responses to endogenous peptides such as endothelin-1. These altered responses may also contribute to the decreased maternal peripheral resistance in pregnancy. The aim of this study was to examine the effect of diabetes on the vasoconstrictor response to endothelin-1 in pregnant women. Small arteries were isolated from nine healthy pregnant, seven type 1 diabetic pregnant women, and five healthy nonpregnant women. Contraction curves were performed on a wire myograph for noradrenaline (1 nM to 30 microM) and endothelin-1 (1 pM to 0.3 microM). Maximum responses and sensitivity were compared by t test. No differences in maximum response to noradrenaline or potassium were seen among the three groups. The maximum response to endothelin-1 was significantly increased in pregnancy (P < 0.05), whereas endothelin-1 sensitivity was reduced in the diabetic compared with the nondiabetic pregnant women (P < 0.05). Pregnant women have an increased maximum vasoconstriction response to endothelin-1 compared with nonpregnant women, whereas diabetic pregnant women demonstrate reduced sensitivity to endothelin-1. These observations suggest that endothelin-1 may play a role in maintaining peripheral vascular tone in normal pregnancy, and the decreased sensitivity seen in pregnant women with diabetes may reflect abnormal vascular reactivity.

Insulin-mediated vasorelaxation in pregnancy

OBJECTIVE

To investigate insulin-mediated vasorelaxation in pregnancy, and the role of nitric oxide in this response.

DESIGN

In vitro study of isolated subcutaneous resistance arteries from pregnant and non-pregnant women.

METHODS

Small arteries (mean vessel diameter <300 microm) were isolated from biopsies of subcutaneous fat from 14 pregnant and seven non-pregnant women. Insulin-mediated attenuation of the vasoconstriction response to noradrenaline, before and after nitric oxide synthase inhibition, was studied in isolated arteries using wire myography. Vessel responses to noradrenaline following incubation with insulin were also tested after endothelial denudation. Maximum responses were compared using one-way ANOVA and Bonferroni's post hoc test for multiple comparisons.

RESULTS

In pregnancy, the maximum vasoconstriction produced by noradrenaline was increased (P < 0.01). Insulin significantly reduced this response in pregnant women (P < 0.01), while inhibition of nitric oxide synthase with Nomega-nitro-L-arginine methyl ester (L-NAME) resulted in potentiation (P < 0.05). Following inhibition of nitric oxide synthase with L-NAME, addition of the insulin was still able to produce a significant attenuation in maximum vasoconstriction to noradrenaline in pregnant women (P < 0.01). Furthermore, the absence of functioning endothelium did not abolish the attenuating effect of the insulin on noradrenaline-induced vasoconstriction in pregnant women (P < 0.01).

CONCLUSIONS

The vasodilatory effect of insulin is not diminished in pregnancy, despite the development of insulin resistance. Furthermore, the attenuation of vasoconstrictor tone is via an endothelium-independent mechanism. This suggests that the vascular dysfunction associated with diabetes mellitus does not occur with physiological insulin resistance.

Tropisetron reduces vomiting after tonsillectomy in children

Nausea and vomiting are common after adenotonsillectomy. Tropisetron is a new, long-acting serotonin antagonist that is an effective antiemetic in adults. Its effect on postoperative nausea and vomiting in children is unknown. We carried out a randomized, double-blind study of the effects of a single i.v. dose of tropisetron on vomiting after tonsillectomy with or without adenoidectomy in children. Forty-eight children undergoing tonsillectomy or adenotonsillectomy received at induction of anaesthesia either tropisetron 0.1 mg kg-1 or placebo. The incidence of vomiting was recorded for the first 24 h after surgery by nursing staff and then by parents after discharge from hospital. Children received metoclopramide 0.15 mg kg-1 as a rescue antiemetic. We found that tropisetron reduced the overall incidence of emetic episodes after surgery (29% compared with 65% in control group; P = 0.019) and the incidence of severe vomiting (0% compared with 52% in control group; P < 0.001). We conclude that tropisetron is an effective antiemetic for children undergoing tonsillectomy.

Anti-glomerular basement membrane (GBM)-antibody-mediated disease with normal renal function

BACKGROUND

This study compared the clinical and laboratory characteristics of patients with anti-glomerular basement membrane (GBM) disease and normal renal function, with those of patients with anti-GBM disease where there was renal impairment.

METHODS

The medical records of the 14 patients who had presented with anti-GBM disease to our hospital in the past 20 years were reviewed.

RESULTS

Five (36%) had a normal serum creatinine or creatinine clearance at presentation. Other features were haemoptysis (2/5, 40%), macroscopic haematuria (2/5, 40%) or systemic symptoms (1/5, 20%). All five (100%) had some degree of haematuria, four (80%) had proteinuria of at least 1 g/day, and none was hypertensive. Anaemia, a raised WCC, or elevated ESR (> 35 mm/h) occurred less often than in patients with impaired renal function (P<0.05). Two of the five (40%) with normal renal function had circulating anti-GBM antibodies, which were present at low or moderate levels; but seven of the nine with renal impairment (77%) had circulating antibodies, with high levels in five. Renal biopsies from patients with normal renal function were normal (1/5, 20%), showed mesangial proliferation (4/5, 80%) or had more than 20% glomeruli sclerosed (1/5, 20%). Complement deposition was present in 2/4 biopsies (50%). The kidneys from patients with renal impairment had crescents in more than 50% glomeruli (9/9, 100%), and four had more than 20% glomeruli sclerosed (44%). All four kidneys from patients with renal impairment that were examined had complement deposits (100%). Treatment was identical in both groups; patients with normal renal function were followed for a median of 48 months, and those with renal impairment for 180 months. There were no further episodes of haemoptysis, haematuria, or other symptoms of relapse in either group. All five patients with normal renal function are alive, and the serum creatinine is less than 0.2 mmol/l in all (100%), but haematuria persists in one (20%), and proteinuria >1 g/day in two (40%). Eight of the nine (89%) patients with impaired renal function survive, but all are currently being dialysed or have had a renal transplant.

CONCLUSION

Patients with anti-GBM disease with normal renal function are not uncommon, and often have a good prognosis. There is less renal damage, possibly because of lower levels of circulating anti-GBM antibodies and less glomerular complement deposition.

Choice of treatment improves quality of life. A study on patients undergoing dialysis

BACKGROUND

Quality of life (QOL) is an important measure of the success of medicine. Choice of treatment is an important variable influencing QOL. We studied QOL in patients undergoing treatment for end-stage renal failure. Until June 1993 our patients needing dialysis could freely choose continuous ambulatory peritoneal dialysis (CAPD); however, since that time most patients have been forced to undergo CAPD because the hemodialysis program is full.

METHODS

We compared QOL in patients accepted before or after June 1993. Forty-five patients undergoing CAPD were studied during the period of choice compared with 44 who had no choice. Quality of life was studied by Bradburn Affect Scale, Mental Health Scale, Campbell Life Satisfaction, Perceived Health, Karnofsky Scale, Activity Scale, Physical Symptoms Scale, and desire for treatment change.

RESULTS

The patients undergoing CAPD in the no-choice group had a lower score than the choice population in 4 of the 7 QOL scales. The Mental Health Scale mean score was 18.4 compared with 15.5, and the patients ranking highest on the Mental Health Scale decreased from 33% to 18%, while those ranking lowest increased 7-fold from 2% to 14% comparing choice with no-choice group. The Bradburn Affect Scale score was +0.7 in the choice group compared with -0.3 in the no-choice group. There were no differences in age, sex, race, or treatment that explained the difference. Influence of other time-related factors is unlikely as there were no similar lower scores with time in the QOL reported by patients in the in-center or assisted self-care hemodialysis or transplant groups.

CONCLUSIONS

Once the freedom of choice of treatment is gone from the patients undergoing CAPD their psychological QOL deteriorates.

The effects of hyperthermia on human endothelial monolayers: modulation of thrombotic potential and permeability

The effects of hyperthermia on potentially prothrombotic endothelial function were investigated by measuring levels of von Willebrand factor, thrombospondin, tissue plasminogen activator and plasminogen activator inhibitor-1 secreted by unstimulated human umbilical vein endothelial cells cultured at 37 degrees C, 39 degrees C, 41 degrees C and 43 degrees C for 24 h. Endothelial barrier function at 43 degrees C was compared with that at 37 degrees C by measuring permeability to radiolabelled human serum albumin and low density lipoprotein. Thrombospondin levels were unaffected by a temperature of 39 degrees C; they increased after 3 h at 41 degrees C and subsequently declined to values significantly below the 37 degrees C control. At 43 degrees C, secretion exhibited a time-dependent decrease. Secretion of von Willebrand factor was not discernibly affected by exposure to 39 degrees C or 41 degrees C. Its response to 43 degrees C resembled that of thrombospondin to 41 degrees C. In contrast, elevated temperatures markedly increased plasminogen activator inhibitor-1 while decreasing t-PA secretion, though after prolonged exposure to 43 degrees C the levels of both returned to control values. After 12-24 h at 43 degrees C, endothelial permeability to both albumin and low density lipoprotein increased markedly. Vascular endothelium may contribute to the thrombotic tendency associated with heat stroke by increasing access to the prothrombotic subendothelium and reducing fibrinolysis.

15-hydroxyeicosatetraenoic acid synthesis from exogenous arachidonate by bronchial mucosa

Arachidonate metabolism in bronchial mucosa was investigated. Bronchial biopsies from four asthmatics and three non-asthmatic controls were challenged with 300, 465, 650 and 960 mOsm/kg saline in the presence of [3H]arachidonate. Supernatants were analysed by reverse-phase high-performance liquid chromatography. The major arachidonate metabolite was identified as 15-monohydroxyeicosatetraenoic acid (15-HETE), with significantly higher production in biopsies from asthmatics than controls. Statistical analysis of the full model explained 81% of the variation (F = 14.8; df = 6, 21; P less than 0.001). Hyperosmolarity and the presence of sarcoid had no significant effect on 15-HETE synthesis, reducing R2 by only 6%.