Non-inferiority randomized controlled trial comparing CricOid pressure and para-laryngeal pressure in parturients undergoing cesarean delivery: NiCOP trial.

BACKGROUND: Cricoid pressure has been surrounded with controversies regarding its effectiveness. Application of ultrasound-guided para-laryngeal (PL) force has been shown to occlude the esophagus effectively compared with cricoid pressure (CP) in awake patients. We hypothesized that there would be no meaningful difference in the change in antero-posterior esophageal diameter from with application of cricoid or para-laryngeal pressure in parturients undergoing cesarean delivery under general anesthesia. METHODS: In this prospective, randomized, non-inferiority trial, 40 parturients scheduled for elective cesarean delivery under general anesthesia were randomized to receive rapid sequence induction with either cricoid pressure (n = 20) or para-laryngeal pressure (n = 20). The antero-posterior diameter of the esophagus, measured by sonography, was the primary outcome. Visualization of the esophagus, its position in relation to the glottic aperture, esophageal occlusion, percentage of glottic opening (POGO), time to intubation, first pass success rate, overall success rate and adverse events like desaturation or bronchospasm were secondary outcomes. RESULTS: The mean change in anterior-posterior diameter in the CP group was 0.17 ±0.1 cm vs. 0.28 ±0.1 cm in the PL group. The mean difference (CP-para-laryngeal pressure) between the groups was -0.11 (95% CI -0.17 to -0.1) cm. As the upper limit of the 95% CI was lower than the prespecified non-inferiority margin (δ = -0.2), non-inferiority was established (P <0.001]. There was no significant difference in the POGO score (P = 0.818), time to intubation (P =0.55), or intubation attempts (P = 0.99). CONCLUSIONS: Para-laryngeal pressure was non-inferior to CP in occluding the esophagus in parturients undergoing cesarean delivery under general anesthesia and furthermore, no significant deterioration in intubation parameters was seen.

Lesion Eccentricity Plays a Key Role in Determining the Pressure Gradient of Serial Stenotic Lesions: Results from a Computational Hemodynamics Study.

PURPOSE: In arterial disease, the presence of two or more serial stenotic lesions is common. For mild lesions, it is difficult to predict whether their combined effect is hemodynamically significant. This study assessed the hemodynamic significance of idealized serial stenotic lesions by simulating their hemodynamic interaction in a computational flow model. MATERIALS AND METHODS: Flow was simulated with SimVascular software in 34 serial lesions, using moderate (15 mL/s) and high (30 mL/s) flow rates. Combinations of one concentric and two eccentric lesions, all 50% area reduction, were designed with variations in interstenotic distance and in relative direction of eccentricity. Fluid and fluid-structure simulations were performed to quantify the combined pressure gradient. RESULTS: At a moderate flow rate, the combined pressure gradient of two lesions ranged from 3.8 to 7.7 mmHg, which increased to a range of 12.5-24.3 mmHg for a high flow rate. Eccentricity caused an up to two-fold increase in pressure gradient relative to concentric lesions. At a high flow rate, the combined pressure gradient for serial eccentric lesions often exceeded the sum of the individual lesions. The relative direction of eccentricity altered the pressure gradient by 15-25%. The impact of flow pulsatility and wall deformability was minor. CONCLUSION: This flow simulation study revealed that lesion eccentricity is an adverse factor in the hemodynamic significance of isolated stenotic lesions and in serial stenotic lesions. Two 50% lesions that are individually non-significant can combine more often than thought to hemodynamic significance in hyperemic conditions.

Obstetric anaesthesiology: manpower and service provision issues in India.

Obstetric anaesthesiologists play a pivotal role as peripartum physicians steering the team of obstetric healthcare providers towards a continuum of medical education, enhanced training and safer patient care. However, in resource-limited countries, deficiency of human resources and hence services available poses challenges to those attempting to reduce maternal mortality rates. Measures to fill the gap include creating a cadre of uniformly well-trained and certified non-physician anaesthesia providers (NPAPs) supervised by a physician obstetric anaesthesiologist and well-equipped rural and urban health care facilities. The Association of Obstetric Anaesthesiologists of India needs to upscale their outreach programs with regular knowledge updates and practical skill training to the NPAPs, medical graduates and postgraduate doctors in these regions. A combination of strong local administrative will, legislation for the provision of essential supplies and a global collaborative effort using checklists and protocols may help to stem gaps in the provision of safe maternal care.

VENUM (Vascular Education iN Undergraduate Medicine): a multicentre evaluation of undergraduate vascular education in the UK.

INTRODUCTION: Vascular surgery is a recognised surgical subspecialty covering an array of circulatory conditions predominately affecting geriatric and diabetic patients. As such, a wide breadth of clinicians will see patients with vascular pathologies, but it is unclear how detailed their knowledge base is. Key to this is the education of medical students, which has been poorly documented during undergraduate training in the UK. VENUM aimed to establish students' perceptions of vascular surgery and their confidence in performing vascular objective structured clinical examination (OCSE) skills. METHODS: During the academic year of 2022/2023, final-year medical students were invited to complete a JISC survey (collaborative authorship). Seventy-seven research leads were recruited to disseminate the survey. Quantitative and thematic analysis was used to assess the data. RESULTS: In total, 240 final-year medical students completed the survey (54% female; 26 medical schools represented). Forty-five per cent of students reported never having had a vascular placement, 24% had never completed a vascular-focused clinical examination and 26% reported low confidence in performing ankle brachial pressure index measurement. An assessment of peripheral arterial disease morbidity was answered correctly in 17% of respondents compared with 92% for angina (chi-square test p<0.001). Students perceived the specialty to be non-inclusive and that early exposure to vascular surgery was required for better engagement with the specialty. CONCLUSION: Students have experienced little exposure to vascular surgery. This may affect future recruitment to vascular surgery and overall knowledge of vascular conditions in UK-trained doctors, which may affect long-term patient management.

Transarterial radioembolization: a systematic review on gaining control over the parameters that influence microsphere distribution.

[Purpose] Transarterial radioembolization (TARE) is an established treatment modality for patients with unresectable liver cancer. However, a better understanding of treatment parameters that influence microsphere distribution could further improve the therapy. This systematic review examines and summarizes the available evidence on intraprocedural parameters that influence the microsphere distribution during TARE as investigated by in vivo, ex vivo, in vitro and in silico studies. [Methods] A standardized search was performed in Medline, Embase and Web of Science to identify all published articles investigating microsphere distribution or dynamics during TARE. Studies presenting original research on parameters influencing the microsphere distribution during TARE were included. [Results] A total of 42 studies reporting a total of 11 different parameters were included for narrative analysis. The investigated studies suggest that flow distribution is not a perfect predictor of microsphere distribution. Increasing the injection velocity may help increase the similarity between flow and microsphere distributions. Furthermore, the microsphere distributions are very sensitive to the radial and axial catheter position. [Conclusion] The most promising parameters for future research which can be controlled in the clinic appear to be microsphere injection velocity as well as the axial catheter position. Up to now, many of the included studies do not take clinical feasibility into account, limiting the translation of results to clinical settings. Future research should therefore focus on the applicability of in vivo, in vitro, or in silico research to patient specific scenarios to improve the efficacy of radioembolization as treatment for liver cancer.

A prospective observational study to identify the effectiveness of intravenous magnesium replacement in an intensive care setting.

Background and Aims: To estimate the incidence of hypomagnesemia and identify the effectiveness of a calculated dose of intravenous magnesium sulfate (MgSO4) in correction of hypomagnesemia and its relationship with renal function in critically ill patients. Material and Methods: All patients admitted in the adult intensive care unit were enrolled in the study and magnesium levels were monitored. Patients with serum magnesium levels <1.7 mg/dL received calculated doses of Intravenous MgSO4. The average rise in serum magnesium levels per gram of MgSO4 administered was calculated and relationship with estimated glomerular filtration rate (eGFR) was identified. Results: In total, 27.27% of patients admitted in our intensive care unit had an incidence of hypomagnesemia. The average rise of serum magnesium levels in patients with hypomagnesemia was 0.13 (±0.05) mg/dl. The average rise of serum magnesium levels was 0.10 (±0.04) mg/dL in patients with eGFR ≥ 90 mL/min/1.73 m2 and 0.15 (± 0.05) mg/dL in patients with eGFR < 90 mL/min/1.73 m2. This difference between the two groups (P-value = 0.002) and the trend of increasing average rise in serum magnesium levels with declining eGFR values (P-value = 0.013) were both statistically significant. Conclusion: Incidence of hypomagnesemia in the critically ill population is around 27.27%. Intravenous administration of 1 g of MgSO4 results in a rise of serum magnesium levels by 0.1 mg/dL in patients with normal eGFR and around 0.15 mg/dL in patients with eGFR values between 30 and 89 mL/min/1.73 m2.

Studying plaque characteristics in extracranial carotid artery disease using CT angiography - Risk predictors beyond luminal stenosis.

OBJECTIVES: Carotid atherosclerosis accounts for around 20 % of ischemic strokes. Literature on CT angiography [CTA] to study plaque morphology is limited. We studied plaque characteristics of extracranial carotid arteries using CTA to ascertain the high risk features beyond luminal stenosis. MATERIALS AND METHODS: Retrospective study design, where patients with carotid territory ischemia who underwent CTA from January 2011 till December 2015 were recruited from medical records. CT images were reviewed for plaque characteristics like attenuation, ulceration, plaque thickness and presence of intraluminal thrombus [ILT] along with percentage stenosis. RESULTS: 114 patients with 201 carotids [102 symptomatic and 99 asymptomatic] were reviewed. Mixed density plaques [p = 0.05], ulceration [p = 0.001], ILT [p = 0.004] and higher soft plaque thickness [p < 0.001] were significantly associated with symptomatic carotids whereas calcified plaques were seen in asymptomatic carotids [p = 0.005]. Plaque characteristics were comparable in symptomatic patients with moderate[50-69 %] and severe[70-99 %] stenosis. Multivariate analysis showed that increased soft plaque thickness remained significantly associated with symptomatic carotid. A cut-off value for soft plaque thickness of 2.75 mm could predict symptomatic carotid disease with a sensitivity of 85.2 % and specificity of 68.0 % [Youden's index]. An increase in soft plaque thickness of 4.0 mm significantly predicts change from asymptomatic to symptomatic carotid [p < 0.05]. CONCLUSIONS: Of the studied CTA plaque characteristics, soft plaque thickness is an independent predictor of symptomatic disease irrespective of the percentage stenosis. Soft plaque thickness over 2.75 mm and smallest detectable change[4 mm] are new measures to help ascertain the risk of ischemic events in carotid atherosclerotic disease.

Diet, Nutrition, and Oral Health: What Influences Mother's Decisions on What to Feed Their Young Children?

The purpose of this study was to learn about mothers' experiences with food choices for their pre-school children in underprivileged communities in Greater Western Sydney (GWS). A total of 20 mother-child dyads living in GWS were recruited to a qualitative study from an ongoing birth cohort study. Participants' houses were visited for semi-structured interviews, which were recorded, transcribed verbatim, and analysed thematically. The interviews yielded five main themes: (i) food choices, nutrition, and health; (ii) accessibility and availability of foods (iii) buying time for parents; (iv) child's age and their preference on food choices; (v) conditioning certain behaviours by family and cultural factors. Nutrition literacy, child's preferences, unhealthy food intake by family members, child's demand, advertising and availability of harmful foods, and time constraints were all mentioned as hurdles to mothers making appropriate meal choices for their children. However, some identified facilitators were promoting parents' knowledge, increasing access to health educational materials, upskilling mothers to providing healthier alternatives, regulating the marketing of unhealth foods. Although, the present study identified critical factors that influence mothers' food choices for their young children, making healthy food choices is a complex practice as it is shaped by individual, social and environmental influences.

Surgical Management of Thoracolumbar Spondylodiscitis in End-Stage Renal Disease.

BACKGROUND: In recent times due to the advancement of haemodialysis techniques, there is increase in the life span of the patients with end-stage renal disease, which tends to increase the risk of complications of bacteraemia due to skin penetration for blood access and leading to propensity for more skeletal and spinal complications. Hence, early diagnosis of spine infection and early initiation of appropriate therapy are important in ensuring successful treatment and preventing further morbidity. MATERIALS AND METHODS: The study included 22 males and 12 females who were known case of end-stage renal disease undergoing haemodialysis therapy and diagnosed with spondylodiscitis based on the clinical and radiological signs. The included patients required surgical stabilization based on the instability, neurological status, and epidural abscess, and non-responsive to medical line of treatment. To measure the degree of pain, Visual Analog Scale was used and British Medical Research Council grading system was used for motor evaluation. Radiography was undertaken one immediately and later at 1, 3, 9, and 12 months and at yearly interval thereafter. Fusion assessment was done by features of consolidation of graft and absence of loosening of implants in both anteroposterior and lateral views will be an indirect evidence of fusion in short-term follow-up. RESULT: Average age of the patients was 62 years (range 40-75 years). Twenty-two patients were male (64.7%) and twelve (35.3%) were female. Sixteen patients had diabetes mellitus and fifteen patients had chronic glomerulonephritis with various underlying causes. All patients presented with back pain with a duration range from 3 to 8 weeks. 13 patients gave a history of on/off fever which was mild grade and 3 patients with high-grade fever. Eighteen patients presented with neurological deficits. The most common organism isolated was Methicillin-Resistant Staphylococcus Aureus (MRSA). At the final follow-up, radiographs revealed a good interbody fusion in 30 of the 34 cases, with 3 cases showed delayed fusion. The mean hemoglobin (Hb) level was 8.8 g/dl and elevated total leucocyte level with mean of 14,425; mean C-reactive protein (CRP) level was 55.6 mg/dl and erythrocyte sedimentation rate (ESR) was 47.5. All patients showed improvement in back pain. Preoperatively, the VAS had a mean of 8.5; post-operatively on day 2, the mean VAS was 3.2, and on 1 month follow-up mean VAS was 2.4. CONCLUSION: In end-stage renal disease patients presenting with back pain, the diagnosis and treatment of spondylodiscitis becomes difficult. Where fever may not be a presenting feature even in cases with severe destructive osteomyelitis, and at times presenting as latent infection. Hence, spinal infection should be suspected as a possible cause of back pain in patients presenting with ESRD, even if they are presenting without fever and MRI study should be performed for the early diagnosis. Surgical intervention with debridement and posterior instrumentation should be considered as a modality of treatment in all cases of spondylodiscitis, with improved clinical outcome in terms of functionality, disability, and rehabilitation and acceptable complication rates in the perioperative period which can be adjusted to the individual cases.

Ultrasound-guided sacral multifidus plane block for analgesia following excision of sacrococcygeal teratoma in two neonates.

Peri-operative pain management in the neonate with a sacrococcygeal teratoma poses significant challenges to the anaesthetist. Involvement of the sacrococcygeal area by the tumour often prevents the use of conventional regional anaesthetic techniques such as caudal or epidural analgesia, with a subsequent reliance on intravenous opioids and paracetamol. Since opioids are associated with respiratory depression, constipation and urinary retention, there is high incidence of opiophobia with consequent inappropriate dosage prescription, particularly in the paediatric population. We describe the use of an ultrasound-guided sacral multifidus plane block in two neonates undergoing surgical excision of sacrococcygeal teratoma. The block is technically easy to perform and also avoids traversing critical structures. Hence, it may be regarded as a promising analgesic technique for painful interventions in the sacrococcygeal area.

Long-term use of 5-alpha-reductase inhibitors is safe and effective in men on active surveillance for prostate cancer.

BACKGROUND: Although 5-alpha-reductase inhibitors (5ARIs) have been shown to benefit men with prostate cancer (PCa) on active surveillance (AS), their long-term safety remains controversial. Our objective is to describe the long-term association of 5ARI use with PCa progression in men on AS. MATERIALS/SUBJECTS AND METHODS: The cohort of men with low-risk PCa was derived from a prospectively maintained AS database at the Princess Margaret (1995-2016). Pathologic, grade, and volume progression were the primary end points. Kaplan-Meier time-to-event analysis was performed and Cox proportional hazards regression was used to determine predictors of progression where 5ARI exposure was analyzed as a time-dependent variable. Patients who came off AS prior to any progression events were censored at that time. RESULTS: The cohort included 288 men with median follow-up of 82 months (interquartile range: 37-120 months). Among non-5ARI users (n = 203); 114 men (56.2%) experienced pathologic progression compared with 24 men (28.2%) in the 5ARI group (n = 85), (p < 0.001). Grade and volume progression were higher in the non-5ARI group compared with the 5ARI group (n = 82; 40.4% vs. n = 19; 22.4% respectively, p = 0.003 for grade progression; n = 87; 43.1% and n = 15; 17.7%, respectively for volume progression p < 0.001). Lack of 5ARI use was independently positively associated with pathologic progression (HR: 2.65; CI: 1.65-4.24), grade progression (HR: 2.75; CI: 1.49-5.06), and volume progression (HR: 3.15; CI: 1.78-5.56). The frequency of progression to high-grade (Grade Group 4-5) tumors was not significantly different between the groups. CONCLUSIONS: Use of 5ARIs diminished both grade and volume progression without an increased risk of developing Grade Groups 4-5 disease.

Efficacy of influenza vaccine (Fluvax) in cancer patients on treatment: a prospective single arm, open-label study.

PURPOSE: Influenza virus infection has significant morbidity and mortality in patients with medical co-morbidities who are also immunosuppressed. The efficacy of the seasonal influenza vaccine has not been well studied in patients receiving chemotherapy. We assessed the efficacy of seasonal influenza vaccine in patients with non-haematological malignancy on active treatment (chemotherapy and targeted therapy). METHODS: A prospective single arm, open label study with 53 patients with non-haematological cancers recruited during the 2011 and 2012 influenza seasons. Participants had one dose of 2011/2012 trivalent vaccine containing strains A/California/7/2009(H1N1), A/Perth/16/2009 (H3N2) and B/Brisbane/60/2008 (Fluvax) prior to or in-between treatment cycles. Haemagglutination inhibition antibody (HIA) titres in serum were measured at baseline 3, 6 and 24 weeks. Primary endpoint: seroconversion rate (SCR) at 3 weeks. Secondary endpoints: late SCR at 6 weeks. rate of sustained sero-protection titres (SPR) at 24 weeks. Seroconversion was defined as postvaccination ≥ 4-fold increase in HIA titre and sero-protection defined as a HIA ≥ 1:40. RESULTS: The SCR at 3 weeks were 35%, 30% and 22.5% to the H1N1, H3N2 and B/Bris strains, respectively. There were no new cases of late SC at 6 weeks or 24 weeks. The SPR at 3 weeks were 72.5%, 65% and 40%, respectively, to H1N1, H3N2 and B/Bris. The SPR at 24 weeks to H1N1, H3N2 and B/Bris were 40%, 52.5% and 17.5%, respectively. CONCLUSIONS: Patients on various solid tumour treatments achieve sero-protection rate congruent with the general population. The sero-protection HIA titres were not sustained at 24 weeks postvaccination.

Expression and activity of key lipases during the larval development of walking catfish (Clarias magur).

The study was conducted to investigate the expression and activity of key lipolytic enzymes during the ontogenetic development of Clarias magur. After partial characterization, the messenger RNA (mRNA) expression analysis of lipoprotein lipase (LPL), pancreatic triacylglycerol lipase (PL), and bile salt-activated lipase (BAL) genes along with the specific lipase activity were performed in larvae from Day 1 after hatching till 34-day posthatch (dph). Heterogeneous patterns of mRNA expression were shown by the important lipolytic enzymes and were detected before first exogenous feeding during the yolk-sac stage. LPL started increasing from 13 dph and peaked at 16 dph followed by a declining trend till 34 dph. However, the PL observed to be peaking at 9, 22, and 30 dph. Similarly, BAL showed an increasing trend from 11 to 22 dph with a significantly high level of mRNA expression at 16 dph. Later, the specific lipase activity was evaluated which appears at Day 1 after hatching with a progressive increase from 7 to 16 dph and a further declining trend afterwards with a peak at 22 dph. The results indicated the development of exocrine pancreas at 16 dph. Furthermore, the transcript levels and the activity of lipases were regulated with the age. Hence, the present study can be helpful in devising different strategies containing optimum lipid levels at a suitable stage of development for improving the survival during larval rearing. Furthermore, the study could be a baseline for elucidating the optimized dietary lipid levels of this catfish during its larval rearing.

Characterizing autonomic response to arousing visual-auditory multi-modal task in Autism Spectrum Disorder (ASD).

Sensory abnormalities are widespread in Autism Spectrum Disorder (ASD). However, their definition is still quite subjective and vague. Here we propose a novel approach for characterization of Autonomic Nervous System responses to sensory stimulation based on electrocardiogram (ECG) assessment. In particular, we develop a preliminary study where autonomic responses of both autistic (ASD = 5) and neurotypical (NT = 5) participants have been evaluated in terms of changes in responsiveness to repeated stimuli. Autonomic control has been estimated via high-frequency heart rate variability (HF-HRV) and low-frequency HRV (LF-HRV). Results show significant differences among groups for the HRV measures (p value = 0.0158), supported by expected changes of HF (p value = 0.0079) and LF (p value = 0.0079) trends over stimulations. We thus conclude that an overall decrease in autonomic arousal can give important insights for devising new habituation metrics in NT and ASD individuals.

Effects of dietary synbiotic on innate immunity, antioxidant activity and disease resistance of Cirrhinus mrigala juveniles.

The dietary supplementation of synbiotic in Cirrhinus mrigala juvenile (with initial body weight ranging from 2.87 ±â€¯0.01 g to 3.26 ±â€¯0.05 g) was evaluated in terms of changes in innate immunity, antioxidant activity and disease resistance against Aeromonas hydrophilla infection. One hundred eighty acclimatized juveniles of mrigal were randomly distributed in the three replicates of each of four experimental groups i.e. control (without Probiotic and Prebiotic), T1 (High Probiotic + Low Prebiotic), T2 (Low Probiotic + High Prebiotic) and T3 (High Probiotic + High Prebiotic), using completely randomized design (CRD). At the end of the feeding trial for 60 days, fish were challenged by Aeromonas hydrophila and survival rate was recorded for the next 15 days. Bacillus subtilis used as a probiotic source and MOS used as a prebiotic source in the experiment. Results showed that innate immunity was comparatively improved in T3 group. Lysozyme activity and respiratory burst activity (NBT) were significantly (P < 0.05) affected in T3 group. Highest activities of antioxidant enzymes (P < 0.05) were reported in T3 group. Cumulative mortality % was found to be lower in the fish fed dietary synbiotic on T3 group after challenging with Aeromonas hydrophilla infection. The results of this study showed that under the experimental conditions, dietary supplementation of synbiotic had a synergestic effect on enhancing innate immunity and disease resistance of Cirrhinus mrigala (P < 0.05).

The effect of spinal hyperbaric bupivacaine-fentanyl or hyperbaric bupivacaine on uterine tone and fetal heart rate in labouring women: a randomised controlled study.

The mechanism for fetal heart rate abnormalities following spinal opioids remains controversial. We evaluated uterine tone, using an intra-uterine pressure catheter, and fetal heart rate abnormalities in 30 women in spontaneous labour with cervical dilation of 3-5 cm having combined spinal-epidural analgesia. Women were randomly assigned to receive a spinal with 2.0 mg hyperbaric bupivacaine plus 15 µg fentanyl, or 2.5 mg hyperbaric bupivacaine. The primary outcome measure was an increase > 10 mmHg in baseline uterine tone in the 30-min period following spinal injection. Only three (20%) women who had a bupivacaine-fentanyl spinal showed a > 10 mmHg increase in baseline tone vs. none who had bupivacaine (p = 0.63). The mean (SD) baseline uterine tone after the spinal injection was 13.3 (7.0) mmHg in the bupivacaine-fentanyl group and 7.7 (2.5) mmHg in the bupivacaine group (p = 0.01). Seven (47%) in the bupivacaine-fentanyl group showed new onset fetal heart rate changes during the 30-min period after the spinal, compared with two (13%) in the bupivacaine group (p = 0.04); however, these were transient and responded to intra-uterine resuscitation. Pain scores, sensory and motor block as well as neonatal outcomes were comparable between the groups. We found that raised baseline uterine tone was not more frequent when using bupivacaine-fentanyl rather than bupivacaine in the spinal component of combined spinal-epidural, although absolute values of baseline tone were higher, and fetal heart rate changes more frequent, in the former group.

Airway changes following labor and delivery in preeclamptic parturients: a prospective case control study.

BACKGROUND: Preeclampsia is associated with greater narrowing of the airway than normal pregnancy, but it is not known if these changes worsen during labor and delivery. The aim of the study was to evaluate the airway during and after labor in women with or without preeclampsia. METHODS: Twenty-five normal and 25 severely preeclamptic pregnant women in early labor were recruited in this single-center, prospective, case-control study. Airway assessment was performed (a) before active labor (b) within one hour of delivery and (c) 24-48 h postpartum. The Mallampati grade was the primary outcome. Sonographic measurements of tongue thickness, anterior neck soft tissue at the level of the hyoid bone and the vocal cords, thyromental distance, and neck circumference, were secondary outcomes. RESULTS: The Mallampati score increased from the pre-labor to the post-labor period in both preeclamptic and normotensive patients (P=0.001 and P=0.002 respectively). A significant difference in tissue thickness at the hyoid level was observed between preeclamptic and normotensive patients pre-labor (P=0.035), post-labor (P=0.05) and postpartum (P=0.05). There was no significant difference in thyromental distance or neck circumference between groups at any time. The total duration of labor and a Mallampati change by one grade correlated (Spearman correlation coefficient 0.473). CONCLUSION: Airway sonography may provide useful bedside anatomical information for prediction of difficult laryngoscopy. The change in airway dimensions and the Mallampati score during labor may persist for 48 h postpartum in both groups. Those with prolonged labor are more susceptible to changes in airway dimensions.

Characterization of epitope specificities of reference antibodies used for the quantification of the birch pollen allergen Bet v 1.

BACKGROUND: Accurate allergen quantification is needed to document the consistency of allergen extracts used for immunotherapy. Herein, we characterize the epitope specificities of two monoclonal antibodies used in an ELISA for the quantification of the major birch pollen allergen Bet v 1, established as a reference by the BSP090 European project. METHODS: The ability of mAbs 5B4 and 6H4 to recognize Bet v 1 isoforms was addressed by immunochromatography. The capacity of each mAb to compete with patients' IgE for binding to Bet v 1 was measured by ELISA inhibition. Epitope mapping was performed by pepscan analysis, site-directed mutagenesis, and hydrogen/deuterium exchange-mass spectrometry. RESULTS: The 5B4 epitope corresponds to a peptide sequence (I56-K68) overlapping with the binding sites of patients' serum IgEs. Mutation of residues P59, E60, and K65 abolishes 5B4 binding to Bet v 1 and reduces the level of IgE recognition. In contrast, 6H4 recognizes a conformational epitope lying opposite to the 5B4 binding site, involving residues located in segments I44-K55 and R70-F79. Substitution of E45 reduces the binding capacity of 6H4, confirming that it is critical for the interaction. Both mAbs interact with >90% of Bet v 1 content present in the birch pollen extract, while displaying a weak cross-reactivity with other allergens of the PR-10 family. CONCLUSIONS: MAbs 5B4 and 6H4 recognize structurally distinct epitopes present in the vast majority of Bet v 1 isoforms. These results support the relevance as a reference method of the Bet v 1-specific quantitative ELISA adopted by the European Pharmacopoeia.