Motion of a non-axisymmetric particle in viscous shear flow

We examine the motion in a shear flow at zero Reynolds number of particles with two planes of symmetry. We show that in most cases the rotational motion is qualitatively similar to that of a non-axisymmetric ellipsoid, and characterised by a combination of chaotic and quasiperiodic orbits. We use Kolmogorov–Arnold–Moser (KAM) theory and related ideas in dynamical systems to elucidate the underlying mathematical structure of the motion and thence to explain why such a large class of particles all rotate in essentially the same manner. Numerical simulations are presented for curved spheroids of varying centreline curvature, which are found to drift persistently across the streamlines of the flow for certain initial orientations. We explain the origin of this migration as the result of a lack of symmetries of the particle’s orientation orbit.</jats:p

Meal patterning and the onset of spontaneous labor

Background: There is a lack of consensus in the literature about the association between meal patterning during pregnancy and birth outcomes. This study examined whether maternal meal patterning in the week before birth was associated with an increased likelihood of imminent spontaneous labor. Methods: Data came from 607 participants in the third phase of the Pregnancy, Infection, and Nutrition Study (PIN3). Data were collected through an interviewer-administered questionnaire after birth, before hospital discharge. Questions included the typical number of meals and snacks consumed daily, during both the week before labor onset and the 24-hour period before labor onset. A self-matched, case-crossover study design examined the association between skipping one or more meals and the likelihood of spontaneous labor onset within the subsequent 24 hours. Results: Among women who experienced spontaneous labor, 87.0% reported routinely eating three daily meals (breakfast, lunch, and dinner) during the week before their labor began, but only 71.2% reported eating three meals during the 24-hour period before their labor began. Compared with the week before their labor, the odds of imminent spontaneous labor were 5.43 times as high (95% CI: 3.41-8.65) within 24 hours of skipping 1 or more meals. The association between skipping 1 or more meals and the onset of spontaneous labor remained elevated for both pregnant individuals who birthed early (37-<39 weeks) and full-term (≥39 weeks). Conclusions: Skipping meals later in pregnancy was associated with an increased likelihood of imminent spontaneous labor, though we are unable to rule out reverse causality

Cystic Fibrosis Transmembrane Conductance Regulator Modulator Therapy: A Review for the Otolaryngologist

Background: Cystic fibrosis (CF) is a genetic disease that may result in multiple systemic disorders and potentially fatal severe respiratory compromise. However, the advent of CF transmembrane conductance regulator (CFTR) modulators has changed the management of CF for patients with select mutations. Although clinical trials have highlighted increased pulmonary function and decreased exacerbations as a result of these novel therapies, their effect on the sinuses has not been well-described. Objective: Our objective is to review the CFTR modulators to provide otolaryngologists, physicians who frequently care for patients with CF, a basic understanding of these drugs and their effects on chronic rhinosinusitis (CRS) in patients with CF. Methods: The clinically approved and available CFTR modulators and specific indications for their use are reviewed. Additionally, a systematic review of these therapies and effects on CRS in CF was performed. Results: Four Food and Drug Administration approved CFTR modulators are available for patients with CF. Current drugs are approved for gating, residual function, or F508del mutations. Multiple reports describe CFTR modulators’ increase in transepithelial ion transport in nasal epithelial cultures; however, clinical studies regarding effects of these modulators on sinonasal health are limited to 5 studies that present new data of the effects of CFTR modulators in CRS. Conclusions: CFTR modulators have changed management of CF. Initial studies of these medications demonstrate promising results in CF; however, there is a paucity of literature describing the effect of CFTR modulators on CF-associated CRS, although initial results are encouraging

Alteration in vaginal microflora, douching prior to pregnancy, and preterm birth

We aimed to determine the relationship of douching prior to pregnancy and bacterial vaginosis (BV) during pregnancy on preterm birth, addressing individual and joint effects. We used a prospective cohort study and assessed vaginal microflora using gram stains and Nugent’s criteria. Douching behaviour was based on self-report about the 12 months prior to pregnancy. Preterm births were categorised as spontaneous or medically indicated. A total of 2561 women provided vaginal specimens and 1492 provided self-reports on douching behaviour

Final results from the Betaseron (interferon β-1b) Pregnancy Registry: a prospective observational study of birth defects and pregnancy-related adverse events

ObjectiveWomen with multiple sclerosis are often diagnosed and treated during their reproductive years. Limited data are available on the safety of treatment during pregnancy. The Betaseron Pregnancy Registry prospectively monitored women exposed to interferon β-1b (IFNβ-1b) during pregnancy to estimate the rates of birth defects, spontaneous abortions (SABs) and other negative outcomes in this population.DesignFrom 2006 to 2011, this observational registry enrolled women exposed prior to conception or during pregnancy (but prior to or without abnormalities on prenatal screening). Follow-up continued from enrolment through the 4-month paediatric visit.SettingPatients in the USA who met these criteria were enrolled in the registry.ResultsThe registry enrolled 99 pregnant women; 3 were lost to follow-up. The earliest exposure to IFNβ-1b occurred during the first trimester for 95 pregnancies and in the third trimester for 1 pregnancy. There were 99 birth outcomes (3 twins), including 86 (86.9%) live births, 11 (11.1%) SABs and 2 (2%) stillbirths. Birth defects were reported in five (5.1%) cases. Rates of birth defects and SAB were not significantly different from population comparators. No developmental concerns were identified at the 4-month paediatric visit.ConclusionsThe small sample size limits the ability to draw definitive conclusions; however, there was no pattern to suggest increased negative outcomes with IFNβ-1b.Clinical trials registration numberNCT00317564

A Comparison of Sphenoid Sinus Osteoneogenesis in Aspirin-Exacerbated Respiratory Disease

Background: Aspirin-exacerbated respiratory disease (AERD) is characterized by excessive leukotriene production, diffuse polyp burden and osteitic bone changes. These bony changes have not been previously characterized. Objective: The aim of this radiographic study is to characterize the bony changes noted on computed tomography (CT) scans of the sphenoid sinus in patients with AERD compared to other diseased sinonasal inflammatory states and non-diseased controls. Methods: A retrospective review of 43 patients with clinically confirmed AERD were included and compared to 22 non-diseased, 9 allergic fungal sinusitis, and 43 chronic rhinosinusitis controls (23 without polyps and 18 with polyps). Comparative measurements were performed using fine-cut CT scans. Sites of comparison were the intersinus septum, the left and right lateral sphenoid wall, the roof, and left and right floor of the sphenoid sinus. Standardized measurements were averaged by two separate rhinologists. Results: Patients with AERD had an average statistically significant increase in bone thickness compared to healthy and diseased controls in nearly every site with the most pronounced changes in the intersinus septum (p < 0.05). Conclusion: Patients with AERD have significantly increased thickness of the sphenoid bone compared to control groups with the most pronounced difference in the intersinus septum. These findings may help clinicians increase suspicion for a diagnosis of AERD who clinically have diffuse nasal polyposis

Sinonasal complications of severe acute respiratory syndrome coronavirus-2: A single center case series

Background: The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in an unprecedented global pandemic. Most infected patients are either asymptomatic or have mild upper respiratory infection symptoms. However, life-threatening sequelae have been observed. In this report, we reviewed nine cases of patients with severe complications from sinonasal disease in the setting of acute SARS-CoV-2 infection. Methods: IRB approval was obtained prior to study initiation. A retrospective chart review was performed of patients admitted to a tertiary hospital with complex sinonasal symptoms that required otolaryngologic evaluation and management in the setting of concomitant SARS-CoV-2 infection. Results: Nine patients, ranging from ages 3 to 71 years, with sinonasal disease and simultaneous SARS-CoV-2 infection were identified. Initial presentations ranged from asymptomatic infection to mild/moderate disease (nasal obstruction, cough) or more severe sequelae including epistaxis, proptosis, or neurologic changes. SARS-CoV-2 tests were positive from one to 12 days after symptom onset, with three patients receiving SARS-CoV-2-directed treatment. Complex disease presentations included bilateral orbital abscesses, suppurative intracranial infection, cavernous sinus thrombosis with epidural abscess, systemic hematogenous spread with abscess development in four distinct anatomic locations, and hemorrhagic benign adenoidal tissue. Eight of nine patients (88.8%) required operative intervention. Patients with abscesses also required prolonged, culture-directed antibiotic courses. Conclusion: Though most SARS-CoV-2 infections are asymptomatic and/or self-limited, there is significant morbidity and mortality in patients with severe disease sequela as outlined in our reported cases. This suggests early identification and treatment of sinonasal disease in this patient population is critical to minimizing poor outcomes. Further research on the pathophysiology of these atypical presentations is needed. Level of Evidence: 4 (Case Series)

Sinus Development and Pneumatization in a Primary Ciliary Dyskinesia Cohort

Background: Primary ciliary dyskinesia (PCD) is a genetically diverse disease which causes impaired mucociliary clearance, and results in pulmonary, otologic, and rhinologic disease in affected patients. Genetic mutations in multiple genes impair the ability of patients to clear mucous from the lungs, middle ear, and sinonasal cavity and lead to chronic pulmonary and sinonasal symptoms. Methods: We identified 17 PCD patients who had available CT scans. Volumes for bilateral maxillary, sphenoid, and frontal sinuses were calculated. A control population of patients who had preoperative CT scans for endoscopic endonasal resection of skull base pathology without sinonasal cavity involvement was also identified. Results: The mean age of PCD was 33 and ranged from 13 to 54 years. Patients were age- and gender-matched to a control group that underwent resection of anterior skull-base tumors and had a mean age of 35 that ranged between 17–53 years old. The volumes for all thee sinus cavities were significantly smaller (p < 0.007) compared to the control population. The average Lund-Mackay score was 10.6 in the PCD cohort (range 6–16) in comparison to an average of 0.7 in the control cohort (range 0–2). Conclusions: Overall sinus volumes were smaller in patients with PCD compared to our control population. Future studies will be aimed at understanding defects in sinus development as a function of specific genetic mutations in PCD patients. Ultimately, a better understanding of the underlying pathophysiology of PCD will allow us to identify the optimal treatment practices for this unique patient group