Polyacrylic acid based plasma fractionation for the production of albumin and IgG: Compatibility with existing commercial downstream processes

Commercial fractionation of human plasma into immunoglobulin- and albumin-rich fractions is often initiated with sequential cold ethanol-based precipitation methods, which have changed little over the past 70 years. The required low temperature (-4 to -8°C) and high concentrations of ethanol 8-40%) necessitate large-scale fixed processing lines, and major capital investment and operating costs. The resulting fractions are then further purified by ethanol based precipitation or chromatographic procedures to obtain the purified final product. Aqueous polyacrylic acid (PAA) based precipitation, which readily interfaces with existing downstream processing, could offer advantages with respect to cost, safety, environmental impact, and flexibility. Sequential precipitation with 7%, 12%, and 20% (w/v) solutions of PAA 8000 in the presence of a kosmotropic salt (sodium citrate) gave fibrinogen-, immunoglobulin-, and albumin-rich fractions with 80-90% yield and 64%, 55%, and 82% purity, respectively. Further purification of the IgG-rich precipitate by caprylic acid precipitation and anion exchange chromatography, achieved a target purity of >99%. This was also achieved for the downstream processing of the albumin-rich precipitate using a two-step ion exchange chromatographic procedure. This work shows that PAA precipitation can be used in place of cold ethanol precipitation to generate crude IgG and albumin fractions which can be purified to final products of acceptable purity.

Ocorrência de ectoparasitas no roedor Oligoryzomys microtis em regiões ao norte do Departamento de La Paz, Bolívia

RESUMO O objetivo deste trabalho foi mapear e descrever a ocorrência de roedores e seus ectoparasitas nas regiões norte do departamento de La Paz, Bolívia. De abril a maio e julho a agosto de 2017, 80 indivíduos da espécie Oligoryzomys microtis foram capturados em armadilhas vivas. Uma amostra aleatória de 36 indivíduos foi analisada quanto à presença de ectoparasitas, encontrando um total de 458 ectoparasitas. Os roedores foram capturados em dois tipos de ambientes: floresta secundária e áreas cultivadas, sendo a área cultivada a área com maior captação de roedores. Dos ectoparasitas, Laelaps sp. foi o gênero com maior abundância e Mysolaelaps sp. o mais prevalente; o gênero Polygenis sp. é aparentemente descrito pela primeira vez na selva amazônica, exigindo estudos adicionais para entender melhor os patógenos que são transmitidos no parasitismo desta pulga em roedores devido à sua importância no ecossistema e para a saúde pública.

Antibody testing for COVID-19: A report from the National COVID Scientific Advisory Panel

Background: The COVID-19 pandemic caused >1 million infections during January-March 2020. There is an urgent need for reliable antibody detection approaches to support diagnosis, vaccine development, safe release of individuals from quarantine, and population lock-down exit strategies. We set out to evaluate the performance of ELISA and lateral flow immunoassay (LFIA) devices. Methods: We tested plasma for COVID (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2) IgM and IgG antibodies by ELISA and using nine different LFIA devices. We used a panel of plasma samples from individuals who have had confirmed COVID infection based on a PCR result (n=40), and pre-pandemic negative control samples banked in the UK prior to December-2019 (n=142). Results: ELISA detected IgM or IgG in 34/40 individuals with a confirmed history of COVID infection (sensitivity 85%, 95%CI 70-94%), vs. 0/50 pre-pandemic controls (specificity 100% [95%CI 93-100%]). IgG levels were detected in 31/31 COVID-positive individuals tested ≥10 days after symptom onset (sensitivity 100%, 95%CI 89-100%). IgG titres rose during the 3 weeks post symptom onset and began to fall by 8 weeks, but remained above the detection threshold. Point estimates for the sensitivity of LFIA devices ranged from 55-70% versus RT-PCR and 65-85% versus ELISA, with specificity 95-100% and 93-100% respectively. Within the limits of the study size, the performance of most LFIA devices was similar. Conclusions: Currently available commercial LFIA devices do not perform sufficiently well for individual patient applications. However, ELISA can be calibrated to be specific for detecting and quantifying SARS-CoV-2 IgM and IgG and is highly sensitive for IgG from 10 days following first symptoms.

Increased Myocardial Stiffness in Patients With High-Risk Left Ventricular Hypertrophy: The Hallmark of Stage-B Heart Failure With Preserved Ejection Fraction

BACKGROUND

Individuals with left ventricular hypertrophy (LVH) and elevated cardiac biomarkers in middle age are at high risk for the development of heart failure with preserved ejection fraction (HFpEF). However, it is unknown what the pathophysiological underpinnings of this high-risk state may be. We tested the hypothesis that patients with LVH and elevated cardiac biomarkers would demonstrate elevated left ventricular (LV) myocardial stiffness in comparison with healthy controls as a key marker for future HFpEF.

METHODS

Forty-six patients with LVH (LV septum >11 mm) and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide [>40 pg/mL] or troponin T [>0.6 pg/mL]) were recruited, along with 61 age- and sex-matched (by cohort) healthy controls. To define LV pressure-volume relationships, right heart catheterization and 3-dimensional echocardiography were performed while preload was manipulated using lower body negative pressure and rapid saline infusion.

RESULTS

There were significant differences in body size, blood pressure, and baseline pulmonary capillary wedge pressure between groups (eg, pulmonary capillary wedge pressure: LVH, 13.4±2.7 versus control, 11.7±1.7 mm Hg, P<0.0001). The LV was less distensible in LVH than in controls (smaller volume for the same filling pressure). When preload was expressed as transmural filling pressure (pulmonary capillary wedge pressure - right atrial pressure), LV myocardial stiffness was nearly 30% greater in LVH than in controls (LVH stiffness constant, 0.053±0.027 versus controls, 0.042±0.020, P=0.028).

CONCLUSIONS

LV myocardial stiffness in patients with LVH and elevated biomarkers (stage-B HFpEF) is greater than in age- and sex-matched controls and thus appears to represent a transitional state from a normal healthy heart to HFpEF. Although the LV myocardial stiffness of patients with LVH is greater than that of healthy controls at this early stage, further studies are required to clarify whether interventions such as exercise training to improve LV compliance may prevent the full manifestation of the HFpEF syndrome in these high-risk individuals.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT03476785 and NCT02039154.

Caracterización productiva y organoléptica de huevos de gallinas de campo de la región sierra del Ecuador

En la Estación Experimental Tunshi de la Escuela Superior Politécnica de Chimborazo, parroquia Licto, a 2712 msnm a una temperatura promedio de 14,92°c. Se evaluó el comportamiento productivo para huevos de gallinas de campo y se analizó las características organolépticas, en 94 aves de traspatios identificadas en la región sierra del Ecuador de las provincias: Pichincha, Bolívar, Loja, Cañar, Tungurahua, y Chimborazo, una vez adaptadas in situ, la investigación tuvo una duración de 120 días. Los datos recogidos fueron tabulados en el programa estadístico SPSS versión Statistic 19, se obtuvo estadísticos descriptivos. Los resultados para peso inicial promedio fue de 1508,78 g; peso final 1502,36 ± 247,61 g; ganancia de peso 175,26 ± 137,20 g; Los parámetros de calidad del huevo fueron: peso promedio 54,95 ± 5,24 g; masa del huevo de 48,15 ± 4,68 g; ancho del huevo de 42,25 mm; longitud del huevo de 55,40 ± 2,60 mm; peso de la cáscara de 6,80 g; grosor de la cáscara de 0,32 ± 0,02mm. Para la medición organoléptica se realizó un análisis sensorial triangular, utilizando 6 combinaciones con 3 repeticiones, total 18 catadores, estos resultados fueron sometidos a Chi-cuadrado obteniendo diferencias significativas en sabor del huevo de campo con relación al comercial. Cabe indicar que la característica de rusticidad en las gallinas, representa un factor importante para la conservación de recursos genéticos, ya que han demostrado poseer una capacidad de adaptación al medio ambiente, que aseguran buenos rendimientos productivos y que resultan interesantes para la seguridad y soberanía alimentaria.

Recurrent Laryngeal Nerve Reinnervation in Rats Posttransection: Neurotrophic Factor Expression over Time

OBJECTIVE

Recurrent laryngeal nerve (RLN) injury causes vocal fold paralysis from which functional recovery is typically absent due to nonselective reinnervation. This study investigates expression of axon guidance cues and their modulators relative to the chronology of reinnervation by examining the expression of glial-derived neurotrophic factor (GDNF), netrin 1, and laminin 111 (LAMA1) in nonpooled laryngeal muscles. This study is the first to describe the post-RLN injury expression pattern of LAMA1, a target of particular interest as it has been shown to switch netrin 1-mediated growth cone attraction to repulsion.

STUDY DESIGN

Animal experiment (rat model).

SETTING

Basic science laboratory.

METHODS

The right RLNs of 64 female Sprague-Dawley rats were transected, with sacrifice at 1, 3, 7, 21, 28, and 56 days postinjury (DPI). Single-animal messenger RNA was isolated from the ipsilateral posterior cricoarytenoid (PCA), lateral thyroarytenoid (LTA), and medial thyroarytenoid (MTA) for quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Immunostaining for LAMA1 expression was performed in the same muscles.

RESULTS

LAMA1 was elevated in the PCA at 3 to 56 DPI, LTA at 7 DPI, and MTA at 14 and 28 DPI. This correlates with the chronology of laryngeal reinnervation. Using a new protocol, single-animal muscle qRT-PCR possible and expression results for GDNF and netrin 1 were similar to previous pooled investigations.

CONCLUSION

Reliable qRT-PCR is possible with single rat laryngeal muscles. The expression of netrin 1 and LAMA1 is chronologically coordinated with muscle innervation in the LTA and MTA. This suggests that LAMA1 may influence netrin 1 to repel axons and delay LTA and MTA reinnervation.

SAT-LB023 Elevated Fasting Plasma Glucose Predicts Higher Odds For Becoming A Super-responder With Gelesis100 In The GLOW Pivotal Weight-loss Study

Background: In a previous pilot weight-loss study, an association was observed between baseline fasting plasma glucose (FPG) levels and the effectiveness of the Gelesis100 treatment. The aim of this subanalysis of the Gelesis Loss Of Weight (GLOW; NCT02307279) study is to further assess the association between FPG and body weight (BW) responders in subjects with overweight or obesity treated with Gelesis100, a non-systemic hydrogel. Methods: This subanalysis was conducted in subjects who were overweight or had obesity and who completed the GLOW study. GLOW was a multicenter, double-blind, placebo-controlled pivotal study with subjects randomized to 2.25 g of Gelesis100 or placebo in capsules taken with 500 mL of water before lunch and dinner while on a hypocaloric diet (-300 kcal/day) for 24 weeks. BW responders at 5% and 10% (super-responders) were analyzed using Logit model comparing Gelesis100 to placebo arms in 2 subgroups of subjects defined by their initial FPG (two consecutive consistent values). Subgroup 1 had normoglycemia (FPG < 100 mg/dL) and subgroup 2 had prediabetes (PD) (FPG ≥ 100 mg/dL and < 126 mg/dL) or untreated type 2 diabetes (T2D) (FPG ≥ 126 mg/dL). Results: The population included 206 subjects (94 males, 112 females, 138 in subgroup 1, 68 in subgroup 2, 105 on Gelesis100, 101 on placebo). In subgroup 1 (mean baseline FPG = 91 mg/dL), BW responders at 5% and 10% in Gelesis100 arm were 60% (placebo arm = 34%, adjusted odds ratio (OR) = 3.1, P = 0.0022) and 22% (placebo arm = 15%, OR = 1.5, P = 0.4254), respectively. In subgroup 2 (mean baseline FPG = 113 mg/dL), BW responders at 5% and 10% in Gelesis100 arm were 72% (placebo arm = 56%, OR = 2.2, P = 0.1509) and 44% (placebo arm = 14%, OR = 6.1, P = 0.0071), respectively. In the overall population, baseline FPG was inversely correlated with BW percent change in the Gelesis100 arm (r = -0.24, P = 0.0144). The safety and tolerability of Gelesis100 demonstrated no increased risk compared to placebo. No serious adverse events were observed in any arm. Conclusion: Gelesis100 offers a compelling new approach in the management of overweight and obesity. Notably, in Gelesis100-treated subjects with PD or untreated T2D, the odds of being super-responders are 6 times higher compared to placebo. This finding may be used as a tool for identifying subjects who are both at higher clinical risk and more likely to achieve greater levels of BW loss when treated with Gelesis100. The mechanisms underlying this finding require further investigations. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Using near-miss events to improve MRI safety in a large academic centre

Near-miss events represent an opportunity to identify and correct errors that jeopardise patient safety. The MRI environment poses potential safety threats and is frequently associated with near misses or adverse events related to improper safety screening for presence of cardiac pacemakers and other potential contraindications. At our institution, MRI safety screening lacked a formalised structure and standardisation; the process relied on a single-step safety screening process. As a result, we observed a significant number of near misses associated with improper MRI screening that resulted in ‘close calls’ in patients with incompatible metals implants. The purpose of this project was to use a quality improvement approach to analyse the near-miss pattern and create a multistep intervention to decrease the number of near misses associated with MRI screening and to ultimately decrease the potential for patient harm. Using the Plan-Do-Study-Act model, we decreased the number of MRI near misses from 22 to zero near misses in 1 year after implementation. The project demonstrates successful transformation of near misses to a never event: a reportable event that should never happen. The project also demonstrates the importance in targeting and prioritising a pattern of near misses, which are unplanned events that do not result in injury but had great potential to do so.

MON-112 Gelesis100 Reduces Insulin Resistance in Patients Who Are Overweight or Have Obesity with High Insulin Resistance: Results of the GLOW Study

Background: Overweight and obesity are predisposing conditions for the development of prediabetes and type 2 diabetes. Insulin resistance caused by excess adiposity is a key factor in this process. Methods: The effect of Gelesis100, a novel hydrogel, was assessed in patients who were overweight or had obesity, without antidiabetic medications, and who completed the Gelesis Loss Of Weight (GLOW; NCT02307279) study. GLOW was a multicenter, double-blind, placebo-controlled pivotal study with patients randomized to 2.25 g of Gelesis100 or placebo in capsules taken with 500 mL of water before lunch and dinner while on a hypocaloric diet (-300 kcal/day) for 24 weeks. Insulin resistance was measured by homeostasis model assessment-insulin resistance (HOMA-IR). Data were analyzed using analysis of covariance and Logit models comparing Gelesis100 to placebo arms in 2 subgroups of patients based on baseline HOMA-IR (subgroup 1, HOMA-IR ≥ 3.0, subgroup 2, HOMA-IR < 3.0). Results: The overall population included 290 patients (132 males, 158 females, 91 in subgroup 1, 199 in subgroup 2, 155 on Gelesis100, 135 on placebo), who were normoglycemic, had prediabetes, or had untreated type 2 diabetes. Statistically significant difference in reduction of HOMA-IR was observed in subgroup 1 (mean baseline HOMA-IR = 5.0) but not in subgroup 2 (mean baseline HOMA-IR = 1.8). Indeed, placebo-subtracted HOMA-IR changes (mean, SE) were -22.3 ± 9.5% (P = 0.0212) and -9.0 ± 9.5% (P = 0.3432) in subgroup 1 and subgroup 2, respectively. Furthermore, in subgroup 1, patients who lost < 5% body weight (n = 44, mean body weight loss = 1.3%) had a statistically significant placebo-subtracted HOMA-IR change of -27.6 ± 13.2% (P = 0.0435), while patients who lost ≥ 5% body weight (n = 47, mean body weight loss = 9.7%) had no statistically significant placebo-subtracted HOMA-IR change (-15.6 ± 13.6%, P = 0.2584). The effect on HOMA-IR decrease was driven by significant reduction in fasting serum insulin. Safety and tolerability of Gelesis100 demonstrated no increased risk compared to placebo. Conclusion: Treatment with Gelesis100 results in a significantly higher reduction in insulin resistance compared to placebo as assessed by HOMA-IR in patients who are overweight or have obesity with elevated baseline HOMA-IR. The results also suggest a potential weight-independent effect of Gelesis100 in the reduction of insulin resistance. If these findings are confirmed in future studies with larger subgroups, Gelesis100 could become a potential new treatment for insulin-resistant clinical conditions associated with overweight and obesity.

A Rare Co-occurrence of Intestinal Malrotation and Hirschsprung's Disease in a Neonate with 13q21.31q33.1 Interstitial Deletion Including the EDNRB Gene

We report a rare co-occurrence of intestinal malrotation and Hirschsprung's disease (HSCR) in a male neonate with a large 38.8 Mb interstitial deletion of chromosome 13 extending from q21.31 to q33.1 including the EDNRB gene, who presented with craniofacial dysmorphic features and central nervous system malformations. The loss of EDNRB gene in addition to bilateral hearing loss and HSCR suggested an additional diagnosis of Waardenburg-Shah's syndrome. This case highlights the fact that prior knowledge of this rare association in infants with 13q deletion syndrome would enable early diagnosis and prompt interventions to prevent gastrointestinal complications.

Supine plasma NE predicts the pressor response to droxidopa in neurogenic orthostatic hypotension

OBJECTIVE

To test whether the plasma levels of norepinephrine (NE) in patients with neurogenic orthostatic hypotension (nOH) predict their pressor response to droxidopa.

METHODS

This was an observational study, which included patients with nOH. All patients had standardized autonomic function testing including determination of venous plasma catecholamine levels drawn through an indwelling catheter while resting supine. This was followed by a droxidopa titration with 100 mg increments in successive days until relief of symptoms, side effects, or the maximum dose of 600 mg was reached. No response was defined as an increase of <10 mm Hg in systolic blood pressure (BP) after 3-minute standing 1 hour after droxidopa administration. Nonlinear regression models were used to determine the relationship between BP response and plasma NE levels.

RESULTS

We studied 20 patients with nOH due to Parkinson disease, pure autonomic failure, multiple system atrophy, or autoimmune autonomic neuropathies. Their supine plasma NE levels ranged from 44 to 850 pg/mL. Lower supine plasma NE levels were associated with greater pressor effect 1 hour after dose (R² = 0.49) and higher standing BP (R² = 0.45). Patients with no pressor response to droxidopa had higher NE levels (382 ± 100 vs 115 ± 20 pg/mL, p = 0.0014). A supine NE level of <219.5 pg/mL had 83% sensitivity and 93% specificity to predict a pressor response (area under the curve = 0.95, p = 0.0023).

CONCLUSIONS

In patients with nOH, lower supine resting plasma NE levels are associated with a greater pressor effect of droxidopa treatment. This finding should help identify patients with nOH most likely to respond to standard doses of droxidopa.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that lower supine plasma NE levels accurately identify patients with nOH more likely to have a greater pressor effect from droxidopa.