The cyto-protective effects of LH on ovarian reserve and female fertility during exposure to gonadotoxic alkylating agents in an adult mouse model

STUDY QUESTION

Does LH protect mouse oocytes and female fertility from alkylating chemotherapy?

SUMMARY ANSWER

LH treatment before and during chemotherapy prevents detrimental effects on follicles and reproductive lifespan.

WHAT IS KNOWN ALREADY

Chemotherapies can damage the ovary, resulting in premature ovarian failure and reduced fertility in cancer survivors. LH was recently suggested to protect prepubertal mouse follicles from chemotoxic effects of cisplatin treatment.

STUDY DESIGN, SIZE, DURATION

This experimental study investigated LH effects on primordial follicles exposed to chemotherapy. Seven-week-old CD-1 female mice were randomly allocated to four experimental groups: Control (n = 13), chemotherapy (ChT, n = 15), ChT+LH-1x (n = 15), and ChT+LH-5x (n = 8). To induce primary ovarian insufficiency (POI), animals in the ChT and ChT+LH groups were intraperitoneally injected with 120 mg/kg of cyclophosphamide and 12 mg/kg of busulfan, while control mice received vehicle. For LH treatment, the ChT+LH-1x and ChT+LH-5x animals received a 1 or 5 IU LH dose, respectively, before chemotherapy, then a second LH injection administered with chemotherapy 24 h later. Then, two animals/group were euthanized at 12 and 24 h to investigate the early ovarian response to LH, while remaining mice were housed for 30 days to evaluate short- and long-term reproductive outcomes. The effects of LH and chemotherapy on growing-stage follicles were analyzed in a parallel experiment. Seven-week-old NOD-SCID female mice were allocated to control (n = 5), ChT (n = 5), and ChT+LH-1x (n = 6) groups. Animals were treated as described above, but maintained for 7 days before reproductive assessment.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the first experiment, follicular damage (phosphorylated H2AX histone (γH2AX) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay), apoptotic biomarkers (western blot), and DNA repair pathways (western blot and RT-qPCR) were assessed in ovaries collected at 12 and 24 h to determine early ovarian responses to LH. Thirty days after treatments, remaining mice were stimulated (10 IU of pregnant mare serum gonadotropin (PMSG) and 10 IU of hCG) and mated to collect ovaries, oocytes, and embryos. Histological analysis was performed on ovarian samples to investigate follicular populations and stromal status, and meiotic spindle and chromosome alignment was measured in oocytes by confocal microscopy. Long-term effects were monitored by assessing pregnancy rate and litter size during six consecutive breeding attempts. In the second experiment, mice were stimulated and mated 7 days after treatments and ovaries, oocytes, and embryos were collected. Follicular numbers, follicular protection (DNA damage and apoptosis by H2AX staining and TUNEL assay, respectively), and ovarian stroma were assessed. Oocyte quality was determined by confocal analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

LH treatment was sufficient to preserve ovarian reserve and follicular development, avoid atresia, and restore ovulation and meiotic spindle configuration in mature oocytes exposed at the primordial stage. LH improved the cumulative pregnancy rate and litter size in six consecutive breeding rounds, confirming the potential of LH treatment to preserve fertility. This protective effect appeared to be mediated by an enhanced early DNA repair response, via homologous recombination, and generation of anti-apoptotic signals in the ovary a few hours after injury with chemotherapy. This response ameliorated the chemotherapy-induced increase in DNA-damaged oocytes and apoptotic granulosa cells. LH treatment also protected growing follicles from chemotherapy. LH reversed the chemotherapy-induced depletion of primordial and primary follicular subpopulations, reduced oocyte DNA damage and granulosa cell apoptosis, restored mature oocyte cohort size, and improved meiotic spindle properties.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This was a preliminary study performed with mouse ovarian samples. Therefore, preclinical research with human samples is required for validation.

WIDER IMPLICATIONS OF THE FINDINGS

The current study tested if LH could protect the adult mouse ovarian reserve and reproductive lifespan from alkylating chemotherapy. These findings highlight the therapeutic potential of LH as a complementary non-surgical strategy for preserving fertility in female cancer patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Regional Valencian Ministry of Education (PROMETEO/2018/137), the Spanish Ministry of Science and Innovation (CP19/00141), and the Spanish Ministry of Education, Culture and Sports (FPU16/05264). The authors declare no conflict of interest.

Predictors of the Pressor Response to the Norepinephrine Transporter Inhibitor, Atomoxetine, in Neurogenic Orthostatic Hypotension

[Figure: see text].

Routine third-trimester ultrasound for the detection of small-for-gestational age in low-risk pregnancies (ROTTUS study): randomized controlled trial

OBJECTIVE

To compare the proportion of small-for-gestational-age (SGA) infants detected by routine third-trimester ultrasound vs those detected by selective ultrasound based on serial symphysis-fundus height (SFH) measurements (standard care) in low-risk pregnancy.

METHODS

This was an open-label randomized controlled trial conducted at a hospital in Kenya between May 2018 and February 2020. Low-risk pregnant women were randomly allocated (ratio of 1:1) to routine ultrasound for fetal growth assessment between 36 + 0 and 37 + 6 weeks' gestation (intervention group) or to standard care, which involved a selective growth scan on clinical suspicion of fetal growth abnormality based on serial SFH measurements (control group). During ultrasound examination, fetal growth was assessed by measurement of the abdominal circumference (AC), and AC < 10^th centile was used to diagnose a SGA fetus. The main prespecified outcomes were the detection of neonatal SGA, defined as birth weight < 10^th centile, and of severe neonatal SGA, defined as birth weight < 3^rd centile. The predictive performance of routine third-trimester ultrasound and selective ultrasound based on serial SFH measurements was determined using receiver-operating-characteristics (ROC)-curve analysis.

RESULTS

Of 566 women assessed for eligibility, 508 (89.8%) were randomized, of whom 253 were allocated to the intervention group and 255 to the control group. Thirty-six babies in the intervention group and 26 in the control group had a birth weight < 10^th centile. The detection rate of SGA infants by routine third-trimester ultrasound vs that by standard care was 52.8% (19/36) vs 7.7% (2/26) (P < 0.001) and the specificity was 95.5% (191/200) and 97.9% (191/195), respectively (P = 0.08). The detection rate of severe SGA was 66.7% (12/18) by routine ultrasound vs 8.3% (1/12) by selective ultrasound based on SFH measurements (P < 0.001), with specificities of 91.7% (200/218) and 98.1% (205/209), respectively (P = 0.006). The area under the ROC curve of routine third-trimester ultrasound in prediction of SGA was significantly greater than that of selective ultrasound based on SFH measurements (0.92 (95% CI, 0.87-0.96) vs 0.68 (95% CI, 0.58-0.77); P < 0.001).

CONCLUSIONS

In low-risk pregnancy, routine ultrasound performed between 36 + 0 and 37 + 6 weeks is superior to selective ultrasound based on serial SFH measurements for the detection of true SGA, with high specificity. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Case Series: Exacerbation of Insulin Resistance With Active COVID 19 Infection

Background: Severe hyperglycemia due to insulin resistance is associated with increased mortality due to induction of pro-inflammatory cytokines, immunodepression, impairing cellular function and healing. We describe 6 patients admitted with COVID19 pneumonia complicated with DKA requiring high dose insulin infusion.

# 1 19 yo African American (AA) male with history of pre-DM and obesity (BMI 41 kg/m2) presented with polyuria, polydipsia, obtunded and intubated in ER. Labs showed pH 7.35, serum sodium (Na) 138 mmol/L, potassium (K) 6.8 mmol/L, chloride (Cl) 85 mmol/L, bicarbonate (HCO3) 10 mmol/L, glucose 1140 mg/dL, lactate 1.4 mmol/L, anion gap (AG) 43, Beta Hydroxybutyrate (BOH) &gt; 4.50 mmol/L. A1c 13.4%. Placed on insulin drip at 29.5 U/hr or 5.7 U/kg/hr. Discharged on Detemir 60 U TID and Novolog 20 U TID ac.

# 2 55 yo female with T2DM and obesity (BMI 37.42 kg/m2) presented with shortness of breath, intubated for hypoxia in ER. Labs showed pH 7.21, serum Na 138 mmol/L, K 5.6 mmol/L, Cl 101 mmol/L, HCO3 13 mmol/L, glucose 557 mg/dL, lactate 5 mmol/L, AG 24, BOH &gt; 0.27 mmol/L. A1c 7.8%. Placed on insulin drip at 23 U/hr or 5 U/kg/hr. Died from multiorgan failure on day 7.

# 3 75 yo Hispanic female with T2DM, HCV, post liver-kidney transplant on immunosuppressants, HTN presented with weakness. Intubated on day 6 for hypoxemia. Placed on stress dose steroids for transplant failure. BMI 30 kg/m2. Labs on day 6 showed pH 6.98, serum Na 140 mmol/L, K 3.5 mmol/L, Cl 100 mmol/L, HCO3 20 mmol/L, glucose 590 mg/dL, AG 20, BOH 1.40 mmol/L. A1c 6.6% a year ago. Placed on insulin drip at 34 U/hr or 10.9 U/kg/hr. She developed ESRD requiring CRRT dialysis. She was made comfort care. Died on day 7.

# 4 38 yo AA male with obesity (BMI 59.5 kg/m2) presenting with confusion, polyuria, polydipsia. Labs showed pH 7.22. serum Na 133 mmol/L, K 6.8 mmol/L, Cl 81 mmol/L, HCO3 15 mmol/L, glucose 1760 mg/dL, lactate 3.8 mmol/L, AG 37, BOH &gt; 4.50 mmol/L. A1c 12.6%. Placed on insulin drip at 36 U/hr or 6 U/kg/hr. Discharged on Detemir 20 U qhs.

# 5 27 yo AA female with T2DM, HTN and obesity (BMI 51 kg/m2), pituitary adenoma presented with seizures. Labs showed pH 7.15, serum Na 133 mmol/L, K 7.0 mmol/L, Cl 84 mmol/L, HCO3 7 mmol/L, serum glucose 951 mg/dL, lactate 1.6 mmol/L, AG 24, BOH &gt;2.45 mmol/L. A1c &gt;15%. Placed on insulin drip at 24 U/hr or 5 U/kg/hr. Died on day 5 from multiorgan failure.

# 6 74 yo Hispanic female with T2DM, HTN and asthma presented with altered mental status. BMI 28 kg/m2. Labs showed pH 7.25, serum Na 155 mmol/L, K 4.6 mmol/L, Cl 125 mmol/L, HCO3 17 mmol/L, serum glucose 779 mg/dL, lactate 2.6 mmol/L, AG 13, BOH &gt;2.45 mmol/L. A1c &gt; 15%. Placed on insulin drip at 24 U/hr or 3.5 U/kg/hr. Died on day 5.

Conclusion: Patients with DM and obesity admitted with Covid19 infection presented with severe insulin resistance and poor outcomes. Cconsideration should be given to assessing therapeutic interventions to enhance insulin sensitivity and improve outcomes.

Need for Screening Triglyceride Levels in Women on Oral Contraceptives

Introduction: Oral contraceptive pills (OCPs) are the most used form of reversible contraceptives by women. Major risks are cardiovascular but OCPs also cause secondary hypertriglyceridemia (HTG) through effects of estrogen, which decreases hepatic triglyceride lipase and lipoprotein lipase activity. This causes increased triglycerides, cholesterol and free fatty acids,¹ which then in turn can lead to life-threatening acute pancreatitis.

Case Description: A 23-year-old morbidly obese (BMI 38.2 mg/kg²) female presented with severe epigastric pain, nausea and vomiting. She had a history of mild intermittent asthma, recently diagnosed pre-diabetes and recently started on OCPs. Initial labs were consistent with diabetic ketoacidosis with glucose 528 mg/dL (65-115 mg/dL), anion gap 21 mEq/L (5-15 mEq), and beta-hydroxybutyrate 2.00 mmol/L (0.02-0.27 mmol/L); and acute pancreatitis with triglyceride 4,425 mg/dL (30-200 mg/dL) and lipase >600 U/L (8-78 UL), confirmed on imaging.

She rapidly deteriorated, developing acute hypoxemic respiratory distress requiring intubation and distributive shock requiring three vasopressors. She progressed into multi-organ failure with acute respiratory distress syndrome, ischemic liver and acute renal failure despite insulin drip, colloidal fluid resuscitation, continuous veno-venous hemofiltration and high positive end-exploratory pressures. She developed rhabdomyolysis, followed by abdominal compartment syndrome requiring decompressive laparotomy that resulted in large volume blood loss and retroperitoneal necrosis needing multiple laparotomies. Ultimately, she became non-responsive off sedation, attributed to malignant cerebral edema that progressed to brain herniation.

While HTG was likely the cause of her pancreatitis, she had normal triglyceride levels on prior routine lab work while not on OCPs.

Discussion: Severe acute pancreatitis is a life-threatening complication of HTG which may be precipitated by use of OCPs. We believe that there is a need for more research in this field and even propose periodic monitoring of HTG in women taking OCPs given the severity of the consequences. While there are currently no guidelines for monitoring lipid levels in women on OCP, appropriate clinical awareness of physicians prescribing OCPs to patients may prevent fatal outcomes.

References: 1. Stumpf, M., Kluthcovsky, A., Okamoto, J., Schrut, G., Cajoeiro, P., Chacra, A. and Bizeli, R. (2018). Acute pancreatitis secondary to oral contraceptive-induced hypertriglyceridemia: a case report. Gynecological Endocrinology, 34(11), pp.930-932.

A haemagglutination test for rapid detection of antibodies to SARS-CoV-2

Serological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests do not require special equipment, are read by eye, have short development times, low cost and can be applied at the Point of Care. Here we describe a quantitative Haemagglutination test (HAT) for the detection of antibodies to the receptor binding domain of the SARS-CoV-2 spike protein. The HAT has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. We will supply aliquots of the test reagent sufficient for ten thousand test wells free of charge to qualified research groups anywhere in the world.

Exploiting hierarchy in medical concept embedding

Objective

To construct and publicly release a set of medical concept embeddings for codes following the ICD-10 coding standard which explicitly incorporate hierarchical information from medical codes into the embedding formulation.

Materials and Methods

We trained concept embeddings using several new extensions to the Word2Vec algorithm using a dataset of approximately 600,000 patients from a major integrated healthcare organization in the Mid-Atlantic US. Our concept embeddings included additional entities to account for the medical categories assigned to codes by the Clinical Classification Software Revised (CCSR) dataset. We compare these results to sets of publicly released pretrained embeddings and alternative training methodologies.

Results

We found that Word2Vec models which included hierarchical data outperformed ordinary Word2Vec alternatives on tasks which compared naïve clusters to canonical ones provided by CCSR. Our Skip-Gram model with both codes and categories achieved 61.4% normalized mutual information with canonical labels in comparison to 57.5% with traditional Skip-Gram. In models operating on two different outcomes, we found that including hierarchical embedding data improved classification performance 96.2% of the time. When controlling for all other variables, we found that co-training embeddings improved classification performance 66.7% of the time. We found that all models outperformed our competitive benchmarks.

Discussion

We found significant evidence that our proposed algorithms can express the hierarchical structure of medical codes more fully than ordinary Word2Vec models, and that this improvement carries forward into classification tasks. As part of this publication, we have released several sets of pretrained medical concept embeddings using the ICD-10 standard which significantly outperform other well-known pretrained vectors on our tested outcomes.

Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia

PURPOSE

Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

METHODS

Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.

RESULTS

We identified 16 unique variants in GNAI1 in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.

CONCLUSION

This collaboration establishes GNAI1 variants as a cause of NDDs. GNAI1-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.

Ten-year experience of protocol-based management of small-for-gestational-age fetuses: perinatal outcome in late-pregnancy cases diagnosed after 32 weeks

OBJECTIVE

To report our 10-year experience of protocol-based management of small-for-gestational-age (SGA) fetuses, based on standardized clinical and Doppler criteria, in late-pregnancy cases.

METHODS

A retrospective cohort was constructed of consecutive singleton pregnancies referred for late-onset (> 32 weeks) SGA (defined as estimated fetal weight (EFW) < 10^th centile) that were classified as fetal growth restriction (FGR) or low-risk SGA, based on the severity of smallness (EFW < 3^rd centile) and the presence of Doppler abnormalities (uterine artery pulsatility index (UtA-PI) ≥ 95^th centile or cerebroplacental ratio (CPR) < 5^th centile). Low-risk SGA pregnancies were followed at 2-week intervals and delivered electively at 40 weeks. FGR pregnancies were followed at 1-week intervals, or more frequently if there were signs of fetal deterioration, and were delivered electively after 37 + 0 weeks' gestation. The occurrence of stillbirth and composite adverse outcome (CAO; defined as neonatal death, metabolic acidosis, need for endotracheal intubation or need for admission to the neonatal intensive care unit) was analyzed in low-risk SGA and FGR pregnancies.

RESULTS

A total of 1197 pregnancies with EFW < 10^th centile were identified and classified at diagnosis as low-risk SGA (n = 619; 51.7%) or FGR (n = 578; 48.3%). Of these, 160 were delivered before 37 weeks' gestation; for obstetric reasons in 93 (58.1%) cases, severe pre-eclampsia in 33 (20.6%), FGR with severe hypoxia in 47 (29.4%) and stillbirth in four (2.5%) (indications are non-exclusive). During follow-up, 52/574 (9.1%) low-risk SGA pregnancies were reclassified as FGR, whereas 22/463 (4.8%) FGR pregnancies were reclassified as low-risk SGA. Overall, there were no stillbirths in the low-risk SGA group and four in the FGR group, all of which occurred before 37 weeks. There were no instances of neonatal death in pregnancies delivered ≥ 37 weeks. The risk of CAO was higher in those meeting antenatal criteria for FGR at 37 weeks than in those classified as low-risk SGA (32/493 (6.5%) vs 15/544 (2.8%); odds ratio, 2.5 (95% CI, 1.3-4.6)). In FGR pregnancies, the adjusted odds ratio (95% CI) for CAO was 6.3 (1.8-21.1) in those with EFW < 3^rd centile, while it was 3.2 (1.5-6.8) and 4.2 (1.9-8.9) in those with UtA-PI ≥ 95^th centile and CPR < 5^th centile, respectively, as compared to FGR pregnancies without each of these criteria.

CONCLUSION

Protocol-based risk stratification with different management and monitoring schemes for late pregnancy with a suspected SGA baby, based on clinical and Doppler criteria, enables identification and tailored assessment of high-risk FGR, while allowing expectant management with safe perinatal outcome for low-risk SGA fetuses. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Performance characteristics of five immunoassays for SARS-CoV-2: a head-to-head benchmark comparison

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic in 2020. Testing is crucial for mitigating public health and economic effects. Serology is considered key to population-level surveillance and potentially individual-level risk assessment. However, immunoassay performance has not been compared on large, identical sample sets. We aimed to investigate the performance of four high-throughput commercial SARS-CoV-2 antibody immunoassays and a novel 384-well ELISA.

METHODS

We did a head-to-head assessment of SARS-CoV-2 IgG assay (Abbott, Chicago, IL, USA), LIAISON SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Saluggia, Italy), Elecsys Anti-SARS-CoV-2 assay (Roche, Basel, Switzerland), SARS-CoV-2 Total assay (Siemens, Munich, Germany), and a novel 384-well ELISA (the Oxford immunoassay). We derived sensitivity and specificity from 976 pre-pandemic blood samples (collected between Sept 4, 2014, and Oct 4, 2016) and 536 blood samples from patients with laboratory-confirmed SARS-CoV-2 infection, collected at least 20 days post symptom onset (collected between Feb 1, 2020, and May 31, 2020). Receiver operating characteristic (ROC) curves were used to assess assay thresholds.

FINDINGS

At the manufacturers' thresholds, for the Abbott assay sensitivity was 92·7% (95% CI 90·2-94·8) and specificity was 99·9% (99·4-100%); for the DiaSorin assay sensitivity was 96·2% (94·2-97·7) and specificity was 98·9% (98·0-99·4); for the Oxford immunoassay sensitivity was 99·1% (97·8-99·7) and specificity was 99·0% (98·1-99·5); for the Roche assay sensitivity was 97·2% (95·4-98·4) and specificity was 99·8% (99·3-100); and for the Siemens assay sensitivity was 98·1% (96·6-99·1) and specificity was 99·9% (99·4-100%). All assays achieved a sensitivity of at least 98% with thresholds optimised to achieve a specificity of at least 98% on samples taken 30 days or more post symptom onset.

INTERPRETATION

Four commercial, widely available assays and a scalable 384-well ELISA can be used for SARS-CoV-2 serological testing to achieve sensitivity and specificity of at least 98%. The Siemens assay and Oxford immunoassay achieved these metrics without further optimisation. This benchmark study in immunoassay assessment should enable refinements of testing strategies and the best use of serological testing resource to benefit individuals and population health.

FUNDING

Public Health England and UK National Institute for Health Research.

Carbidopa for Afferent Baroreflex Failure in Familial Dysautonomia: A Double-Blind Randomized Crossover Clinical Trial

Afferent lesions of the arterial baroreflex occur in familial dysautonomia. This leads to excessive blood pressure variability with falls and frequent surges that damage the organs. These hypertensive surges are the result of excess peripheral catecholamine release and have no adequate treatment. Carbidopa is a selective DOPA-decarboxylase inhibitor that suppresses catecholamines production outside the brain. To learn whether carbidopa can inhibit catecholamine-induced hypertensive surges in patients with severe afferent baroreflex failure, we conducted a double-blind randomized crossover trial in which patients with familial dysautonomia received high dose carbidopa (600 mg/day), low-dose carbidopa (300 mg/day), or matching placebo in 3 4-week treatment periods. Among the 22 patients enrolled (13 females/8 males), the median age was 26 (range, 12-59 years). At enrollment, patients had hypertensive peaks to 164/116 (range, 144/92 to 213/150 mm Hg). Twenty-four hour urinary norepinephrine excretion, a marker of peripheral catecholamine release, was significantly suppressed on both high dose and low dose carbidopa, compared with placebo (P=0.0075). The 2 co-primary end points of the trial were met. The SD of systolic BP variability was reduced at both carbidopa doses (low dose: 17±4; high dose: 18±5 mm Hg) compared with placebo (23±7 mm Hg; P=0.0013), and there was a significant reduction in the systolic BP peaks on active treatment (P=0.0015). High- and low-dose carbidopa were similarly effective and well tolerated. This study provides class Ib evidence that carbidopa can reduce blood pressure variability in patients with congenital afferent baroreflex failure. Similar beneficial effects are observed in patients with acquired baroreflex lesions.

An Intramolecular Salt Bridge Linking TDP43 RNA Binding, Protein Stability, and TDP43-Dependent Neurodegeneration

The majority of individuals with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) exhibit neuronal cytoplasmic inclusions rich in the RNA binding protein TDP43. Even so, the relation between the RNA binding properties of TDP43 and neurodegeneration remains obscure. Here, we show that engineered mutations disrupting a salt bridge between the RNA recognition motifs of TDP43 interfere with RNA binding and eliminate the recognition of native TDP43 substrates. The same mutations dramatically destabilize TDP43, alter its subcellular localization, and abrogate TDP43-dependent neuro-degeneration. Worms harboring homologous TDP-1 mutations phenocopy knockout strains, confirming the necessity of salt bridge residues for TDP43 function. Moreover, the accumulation of functional TDP43, but not RNA binding-deficient variants, disproportionately affects transcripts encoding ribo-some and oxidative phosphorylation components. These studies demonstrate the significance of the salt bridge in sustaining TDP43 stability and RNA binding properties, factors that are crucial for neurodegeneration arising from TDP43 deposition in ALS and FTD.

Flores et al. uncover essential roles for an intramolecular salt bridge in the function of TDP43, an RNA binding protein implicated in neurodegenerative diseases. Salt bridge interruption attenuates TDP43 RNA binding affinity and specificity, destabilizes the protein, and prevents TDP43-mediated neurotoxicity arising from misprocessing of ribosomal and mitochondrial transcripts.

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.

SUN-LB88 Thyrotoxic Periodic Paralysis in Hispanic Patients

BACKGROUND: Thyrotoxic periodic paralysis (TPP) presents as acute intermittent attacks of weakness related to hypokalemia, commonly reported in Asians and rare in Hispanics(1). Patients with TPP will have triiodothyronine (T3) triggered increased Na+/K+ ATPase pump activity and transcription of the KCNJ18 gene that encodes for the Kir2.6 channel(2). This permits insulin, catecholamines, stress and alcohol(3) to increase cellular intake of potassium, which causes depolarization and leads to weakness and paralysis. We report a case of TPP in a young Hispanic man who presented with lower extremity weakness and falls. CASE PRESENTATION: A 34-year-old Hispanic man with Graves’ disease, non-adherent to medications presented with generalized weakness, more pronounced in legs, and recurrent falls. Physical examination was unremarkable except for mild enlargement of thyroid gland and abnormal gait due to weakness. Laboratory data showed hypokalemia of 1.8 mmol/L (3.7-5.1 mmol/L) and a TSH level of &lt;0.004 mIU/L (0.34-5.6 mIU/L). Free T4 3.74 ng/dL (0.6-1.6 ng/dL), free T3 597 pg/dL (230-420 Pg/dL), thyroid stimulating Ig 148 (&lt;130). Electrocardiogram did not show U waves. Radio iodine 123 scan of thyroid revealed diffusely increased 24-hour radioactive uptake of 66.5% (10-30%). The patient was diagnosed with TPP and supplemented with three doses of potassium 40 mEq IV infusion. Methimazole and metoprolol were started. He made a good clinical recovery within days. After discharge, he was treated with I-131 (13 mci) and developed postablative hypothyroidism on long term. He was euthyroid on levothyroxine. He did not have any recurrence of weakness at 7-year follow-up. CONCLUSION: TPP is uncommonly seen in Hispanics patients as opposed to Asians(3). Physicians should consider TPP as part of the differential diagnosis in young hyperthyroid Hispanic men presenting with weakness or paralysis, as early recognition and treatment can reduce recovery time and potentially prevent tachyarrhythmia or death. REFERENCES: 1. Matta A, Koppala J, Gossman W. Thyrotoxic hypokalaemic periodic paralysis: a rare presentation of Graves’ disease in a Hispanic patient. BMJ Case Rep. 2014;2014. 2. Ryan DP, Ptacek LJ. Mutations in Potassium Channel Kir2.6 Cause Susceptibility to Thyrotoxic Hypokalemic Periodic Paralysis. Cell, 140(1), pp.88-98. 3. Amblee, A. and Gulati, S. (2016). Thyrotoxic Periodic Paralysis: Eight Cases in Males of Hispanic Origin from a Single Hospital. AACE Clinical Case Reports, 2(1), pp.e58-e64.

Impact of depressive symptoms on self-perceived severity of autonomic dysfunction in multiple system atrophy: relevance for patient-reported outcomes in clinical trials

PURPOSE

To assess the relationship between depressive symptoms and self-perceived severity of autonomic dysfunction in patients with multiple system atrophy (MSA).

METHODS

Cross-sectional evaluation of patients with MSA who underwent autonomic testing, Unified MSA Rating Scale (UMSARS)-1 and -2, rating of the presence and severity of depressive symptoms (Zung scale), quality of life (SF-36), body vigilance, anxiety (Spielberger's anxiety scale), severity of autonomic dysfunction with the Composite Autonomic Symptoms Score (COMPASS-31), and severity of orthostatic hypotension (OH) symptoms with the Orthostatic Hypotension Questionnaire (OHQ).

RESULTS

Fifty-eight patients (32 women) with probable MSA (aged 61.8 ± 8.6 years; disease duration 4.3 ± 2.1 years) were studied. Forty patients (69%) had symptoms of depression in the Zung scale. Age, disease duration, and motor disability were similar in those with and without symptoms of depression. Despite a similar orthostatic blood pressure fall, the severity of orthostatic symptoms was higher in patients with symptoms of depression (p = 0.004). Depression scores were associated with higher burden of autonomic symptoms (R = 0.401, p = 0.02), specifically with the COMPASS-31 items related to orthostatic intolerance (R = 0.337, p = 0.045), and with the OHQ (R = 0.529; p < 0.001). A multivariable regression model including age, sex, UMSARS, and drop in systolic blood pressure upon head-up tilt as covariates showed that the burden of depressive symptoms was independently associated with the OHQ score: for every 1-unit increase in the Zung depression score, there was a 1.181-point increase in the total OHQ score.

CONCLUSIONS

In patients with MSA, depressive symptoms worsen the perceived severity of autonomic symptoms in general and orthostatic hypotension in particular. Our findings have implications for clinical trial design.

Molecular detection of Rickettsia species in ticks collected in the Mexico-USA transboundary region

Zoonotic tick-borne diseases, including those caused by Rickettsia species, continue to have serious consequences for public health worldwide. One such disease that has emerged as a major problem in several countries of the American continent is the Rocky Mountain Spotted Fever (RMSF) caused by the bacterium Rickettsia rickettsii. Several tick species are capable of transmitting R. rickettsia, including Amblyomma cajennense, A. aureolatum, A. imitator, Rhipicephalus sanguineus, Dermacentor andersoni, D. variabilis and possibly A. americanum. Despite previous reports in Mexico linking new outbreaks of RMSF to the presence of these tick species, no robust measures have tackled transmission. In the present study, we amplified R. rickettsii from 109 test DNA samples extracted from ticks collected from several animals and humans of Tamaulipas, Mexico, between November 2015 and December 2017. Our analysis revealed the presence of R. rickettsii in six samples and these findings contribute to a spatial distribution map that is intended to minimize the risk of transmission to humans.

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.