COVID-19 and Guillain-Barré syndrome: A single-center prospective case series with a 1-year follow-up

Single reports of Guillain-Barré syndrome (GBS) have been reported worldwide during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. While case reports are likely to be biased toward uncommon clinical presentations, systematic assessment of prospective series can highlight the true clinical features and spectrum. In this prospective, observational study, we included all consecutive patients who developed GBS. In patients with SARS-CoV-2 infection as antecedent, the time-gap between the infection and GBS onset had to be ≤30 days. The referral was a neurological University Research Hospital, in the Italian Region more severely involved by the pandemic, and hospitalizing both COVID+ and non-COVID neurological diseases. Clinical, laboratory, cerebrospinal fluid, and electromyographic features of GBS diagnosed between March 2020 and March 2021 were compared to a retrospective series of GBS diagnosed between February 2019 and February 2020 (control population). Nasopharyngeal swab was still positive at GBS onset in 50% of patients. Mild-to-moderate COVID-related pneumonia, as assessed by X-ray (6 patients) or X-ray plus computerized tomography (2 patients) co-occurred in 6 of 10 patients. GBS diagnosed during the pandemic period, including 10 COVID-GBS and 10 non–COVID-GBS, had higher disability on admission (P = .032) compared to the GBS diagnosed between February 2019 and 2020, possibly related to later hospital referral in the pandemic context. Compared to non–COVID-GBS (n = 10) prospectively diagnosed in the same period (March 2020–2021), post–COVID-GBS (n = 10) had a higher disability score on admission (P = .028), lower sum Medical Research Council score (P = .022) and lymphopenia (P = .025), while there were no differences in GBS subtype/variant, severity of peripheral involvement, prognosis and response to treatment. Cerebrospinal fluid search for SARS-CoV-2 RNA and antiganglioside antibodies were negative in all COVID+ patients. Temporal clustering of cases, coinciding with the waves of the pandemic, and concomitant reduction of the incidence of COVID-negative GBSs may indicate a role for SARS-CoV-2 infection in the development of GBS, although the association may simply be related to a bystander effect of systemic inflammation; lack of prevalence of specific GBS subtypes in post–COVID-GBS also support this view. GBS features and prognosis are not substantially different compared to non–COVID-GBS.     

Antioxidant properties of ursodeoxycholic acid

We have investigated potential antioxidant properties of the clinically relevant bile acid UDCA, which reaches therapeutic concentrations up to 0.09 and 29 mM, respectively, in human plasma and bile. UDCA was an excellent scavenger of OHz.rad; generated by FeCl(3)-EDTA, H(2)O(2) and ascorbate in the deoxyribose oxidation test, showing IC(min) and IC(50) values of 0.02 and 0.2 mM, respectively, and a second-order rate constant for reaction with OHz.rad; of 2+/-0.1 x 10(10)M(-1)s(-1). Notably, the drug could enhance at 1.5 mM concentration the antioxidant capacity of human bile against OHz.rad;-induced deoxyribose oxidation. UDCA also showed antioxidant effects in the deoxyribose test performed with nonchelated iron ions, such as Fe(2+) plus H(2)O(2) (IC(min): 7 mM, IC(50): 20 mM) or Fe(3+) plus H(2)O(2) and ascorbate (IC(min): 0.3 mM, IC(50): 5 mM), and inhibited ferrozine-Fe(2+) and desferrioxamine-Fe(3+) complexes formation with IC(50) values of, respectively, 12 and 0.3 mM, indicating that the drug interacts more with iron(III) than with iron(II). Moreover, UDCA significantly inhibited phospholipid liposome peroxidation induced by the OHz.rad;-generating system FeCl(3)-EDTA, H(2)O(2) and ascorbate (IC(min): 0.75 mM, IC(50): 3 mM), and by peroxyl radicals generated in the aqueous phase by AAPH (IC(min): 8 mM, IC(50): 14 mM). UDCA, even at 25 mM concentration, was ineffective on the lipoperoxidation mediated by Fe(2+) alone, but at the same concentration counteracted significantly that by Fe(3+) plus ascorbate, further pointing to its preferential antioxidant interaction with iron(III).In conclusion, UDCA has direct antioxidant properties, which are especially relevant against Fe(3+)- and OHz.rad;-dependent biomolecular oxidative damage; such properties are evident at therapeutically relevant drug concentrations, suggesting that UDCA could act as an antioxidant in vivo.     

Safety and efficacy of topiramate in neonates with hypoxic ischemic encephalopathy treated with hypothermia (NeoNATI)

ABSTRACT: BACKGROUND: Despite progresses in neonatal care, the mortality and the incidence of neuro-motor disability after perinatal asphyxia have failed to show substantial improvements. In countries with a high level of perinatal care, the incidence of asphyxia responsible for moderate or severe encephalopathy is still 2--3 per 1000 term newborns. Recent trials have demonstrated that moderate hypothermia, started within 6 hours after birth and protracted for 72 hours, can significantly improve survival and reduce neurologic impairment in neonates with hypoxic-ischemic encephalopathy. It is not currently known whether neuroprotective drugs can further improve the beneficial effects of hypothermia. Topiramate has been proven to reduce brain injury in animal models of neonatal hypoxic ischemic encephalopathy. However, the association of mild hypothermia and topiramate treatment has never been studied in human newborns. The objective of this research project is to evaluate, through a multicenter randomized controlled trial, whether the efficacy of moderate hypothermia can be increased by concomitant topiramate treatment. METHODS: Term newborns (gestational age >= 36 weeks and birth weight >= 1800 g) with precocious metabolic, clinical and electroencephalographic (EEG) signs of hypoxic-ischemic encephalopathy will be randomized, according to their EEG pattern, to receive topiramate added to standard treatment with moderate hypothermia or standard treatment alone. Topiramate will be administered at 10 mg/kg once a day for the first 3 days of life. Topiramate concentrations will be measured on serial dried blood spots. 64 participants will be recruited in the study. To evaluate the safety of topiramate administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of topiramate, the neurologic outcome of enrolled newborns will be evaluated by serial neurologic and neuroradiologic examinations. Visual function will be evaluated by means of behavioural standardized tests. DISCUSSION: This pilot study will explore the possible therapeutic role of topiramate in combination with moderate hypothermia. Any favourable results of this research might open new perspectives about the reduction of cerebral damage in asphyxiated newborns. Trial registration Current Controlled Trials ISRCTN62175998; ClinicalTrials.gov Identifier NCT01241019; EudraCT Number 2010-018627-25.     

Targeted agents for HER2-positive breast cancer in older adults: current and future perspectives

ABSTRACT

Introduction: One-third of breast cancer (BC) cases worldwide occur in women aged 65 years and older, with 10 to 15% overexpressing the human epidermal growth factor receptor 2 (HER2). Although several HER2-targeted therapies have been developed, the lack of data regarding their use in older patients hampers evidence-based decision-making for this population.

Areas Covered: We review current evidence on the efficacy and safety of HER2-targeted therapies in older adults with BC, focusing on approved therapies such as trastuzumab, lapatinib, pertuzumab, ado-trastuzumab-emtansine, and neratinib. Additionally, we discuss drugs under development to target the HER2-receptor, and to overcome resistance to existing therapies. Finally, we highlight the cardiotoxicity of HER2-targeted drugs among older adults.

Expert Opinion: Older adults are underrepresented in trials of HER2-targeted therapies in BC. We propose strategies to increase recruitment of older adults in clinical trials in order to increase the evidence base to treat this growing population.     

Vitrectomy for optic disc pit maculopathy: a long-term follow-up study

Graefe's Archive for Clinical and Experimental Ophthalmology - To evaluate the clinical outcomes of vitrectomy with induction of posterior vitreous detachment for the treatment of optic disc...     

Preseptostomy Myocardial Infarction in a Patient with Complex Transposition of the Great Arteries

In transposition of the great arteries, systemic venous return is preferentially routed to the aorta, and any spontaneous or iatrogenic emboli may therefore cause organ infarction. We present a patient with transposition of the great arteries who developed myocardial infarction prior to balloon septostomy and, also, was later documented to have sustained brain infarction despite adequate precautionary measures. Minimal handling of venous sites in these patients is crucial.     

Iterative computational design and crystallographic screening identifies potent inhibitors targeting the Nsp3 macrodomain of SARS-CoV-2

The nonstructural protein 3 (NSP3) of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) contains a conserved macrodomain enzyme (Mac1) that is critical for pathogenesis and lethality. While small-molecule inhibitors of Mac1 have great therapeutic potential, at the outset of the COVID-19 pandemic, there were no well-validated inhibitors for this protein nor, indeed, the macrodomain enzyme family, making this target a pharmacological orphan. Here, we report the structure-based discovery and development of several different chemical scaffolds exhibiting low- to sub-micromolar affinity for Mac1 through iterations of computer-aided design, structural characterization by ultra-high-resolution protein crystallography, and binding evaluation. Potent scaffolds were designed with in silico fragment linkage and by ultra-large library docking of over 450 million molecules. Both techniques leverage the computational exploration of tangible chemical space and are applicable to other pharmacological orphans. Overall, 160 ligands in 119 different scaffolds were discovered, and 153 Mac1-ligand complex crystal structures were determined, typically to 1 Å resolution or better. Our analyses discovered selective and cell-permeable molecules, unexpected ligand-mediated conformational changes within the active site, and key inhibitor motifs that will template future drug development against Mac1.

The macrodomain of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) nonstructural protein 3 (NSP3) (Mac1) presents an intriguing target for drug discovery (1–5). Upon viral infection, host cells initiate an innate interferon-mediated immune response leading to the expression of poly-(ADP-ribose)-polymerases (PARPs), which catalyze the antiviral posttranslational addition of ADP-ribose (ADPr) to a large range of target proteins (6). Mac1 enzymatically reverses this mono-ADP-ribosylation, counteracting immune signaling (7). Promisingly, inactivation of Mac1 by single-point mutations in the ADPr-binding site significantly reduced lethality and pathogenicity in mice after SARS-CoV infection (8). Small-molecule inhibitors of SARS-CoV-2 Mac1 should therefore offer novel therapeutics to mitigate COVID-19 (9, 10).A challenge for the development of such inhibitors has been the lack of small-molecule modulators of macrodomain activity, other than ADPr; indeed, only recently have quantitative assays been developed (10, 11). This is true not only for Mac1 from SARS-CoV-2, but also for the overall family of enzymes, which lack good chemical matter by which their activity can be probed, despite their importance in several areas of health and diseases. Accordingly, to map the recognition determinants of Mac1, we adopted a biophysical approach, screening for fragment ligands using protein crystallography, molecular docking, isothermal titration calorimetry (ITC), differential scanning fluorimetry (DSF), and a binding assay based on homogeneous time-resolved fluorescence (HTRF) (12). Mac1 proved to be unusually amenable to structure determination, enabling us to determine the structures of over 230 fragment complexes, typically to ultra-high resolution (often better than 1.1 Å), affording us a detailed map of enzyme hot spots with chemical matter of sufficient potency with which to optimize a quantitative assay (12, 13).Nevertheless, our best fragments remained of modest potency, with none more potent than 180 µM. Here, we describe the discovery and optimization of potent macrodomain ligands using two strategies (Fig. 1). In the first, we sought to link and merge pairs of fragments to create larger molecules that exploited multiple hot spots, so reaching higher affinities. This used a fragment-linking method (12), adapted to explore a virtual library of 22 billion readily synthesizable molecules (14). In the second approach, we exploited the hot spots revealed by the initial fragments to guide computational docking of ultra-large chemical libraries of lead-like molecules, potentially more potent than the fragments docked in our original study (12). Both approaches ultimately led to compounds with IC₅₀ values as low as 0.4 µM for the merged fragments and as low as 1.7 µM for the docking hits (Fig. 1). These represent the most potent inhibitors reported for any member of the broad family of macrodomains. Furthermore, the many X-ray crystal structures determined here provide an extensive resource for drug development campaigns against this promising antiviral target.Open in a separate windowFig. 1.Overview of the structure-based strategies used to discover ligands that bind to the NSP3 macrodomain of SARS-CoV-2 (Mac1).