Corrigendum to:Genome Mining of Oxidation Modules in trans -Acyltransferase Polyketide Synthases Reveals a Culturable Source for Lobatamides (Angewandte Chemie International Edition, (2020), 59, 20, (7761-7765), 10.1002/anie.201916005)

In the abstract and on page 7763 of this Communication, the authors erroneously describe Gynuella sunshinyii as the first culturable source for lobatamides. However, Suzumura et al. reported in 1997 the isolation of the compound YM-75518, which has the same structure as lobatamide A, from Pseudomonas sp. Q38009. This error does not affect the results of any of the experiments and data in this Communication. The authors sincerely apologize for this error

children with acute neurological emergency

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Structural and functional papez circuit integrity in amyotrophic lateral sclerosis

Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuit—a circuit known to participate in memory processes—is structurally and functionally affected in ALS patients (n = 20) compared with healthy controls (n = 15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established

Impaired growth and abnormal microstructure of supratentorial gray and white matter regions in a child with Joubert syndrome

The interaction between the cerebellum and cerebrum forms the anatomic basis of the cerebellar role in neurocognitive functions. We performed whole-brain atlas-based analysis of volumetric and DTI data in a 16-month-old boy with Joubert syndrome and 5 age-matched controls. In our patient, we found a decrease in volume of multiple gray and white matter regions, and reduced fractional anisotropy in selected white matter regions. These findings result from trophic trans-synaptic effects and disconnection of the cerebellar-cerebral pathway secondary to a malformed cerebellum. In addition, we found an increase in fractional anisotropy in multiple cortical gray matter regions, which may reflect disrupted cortical neuronal radial glial cell scaffolding and neuronal laminar organization

Tecto-cerebellar dysraphism with occipital encephalocele: not a distinct disorder, but part of the Joubert syndrome spectrum?

Magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) findings in a 4-year-old child with occipital encephalocele, cerebellar vermis hypogenesis, and tectal malformation are presented. The neuroimaging findings are reminiscent of tectocerebellar dysraphism with an occipital encephalocele (TCD-OE). Additionally, elongated, thickened, and horizontally orientated superior cerebellar peduncles, an abnormally deepened interpeduncular fossa, subependymal heterotopia, and focal cortical dysplasia were noted. Color-coded fractional anisotropy (FA) maps revealed an absence of the decussation of the superior cerebellar peduncles. These findings are highly suggestive of Joubert syndrome and related disorders (JSRD). Our report and the review of the published cases suggest that TCD-OE is not a nosological entity, but may represent the structural manifestation of heterogeneous disorders such as the JSRD spectrum. DTI may be very helpful to differentiate between similar midbrain-hindbrain malformations

Feasibility of diffusion tensor tractography of brachial plexus injuries at 1.5 T.

OBJECTIVE: The objective of this study was to examine the feasibility of diffusion tensor imaging and diffusion tensor tractography (DTT) at 1.5 T for the detection of nerve root avulsions in patients with brachial plexus injuries (BPI). MATERIALS AND METHODS: We performed a 1.5-T magnetic resonance imaging on 28 patients (mean [SD] age, 25 [9.1]) with BPI using the following imaging protocol: (a) magnetic resonance myelography (MRM), (b) magnetic resonance neurography, and (c) diffusion tensor imaging. A reproducible tractography approach was developed to assess the myeloradicular continuity, which consists of multiple regions of interests placed on each hemicord, including the ventral and dorsal rootlets from C4 to T2 nerve roots. Two independent observers blindly evaluated DTT and MRM studies. The degree of agreement between DTT and MRM findings was estimated on a per-root basis on the 140 nerve roots (C5-T1) on the injured side by calculation of the κ coefficient (K value) and the Bland-Altman plot analysis. The diagnostic accuracy of DTT was assessed by comparing it with the MRM findings of the 140 nerve roots on the injured side on a per-root basis. RESULTS: Diffusion tensor tractography allowed a complete visualization of the C5-T1 intact nerve roots on the normal side in 100% of studies.Complete nerve root avulsions were recognized on DTT either as a total loss of fibers or as a very short segment of incoherent fibers in apparent continuity with the spinal cord.The MRM identified 88 intact nerve roots (62.9%), 44 completely avulsed nerve roots (31.4%), and 8 partially avulsed nerve roots (5.7%). The DTT and MRM were concordant in 127 of the 140 nerve roots (90.7%) and exhibited an excellent overall agreement (K value, 80.8). The brachial plexus DTT had an 88.1% sensitivity, 98.1% positive predictive value, 98.8% specificity, 92.6 negative predictive value, and a 94.5% overall accuracy for detecting the presence of a nerve root avulsion. The κ coefficients for the interobserver reliability of DTT and MRM were 0.85 and 0.80, respectively. CONCLUSIONS: Our results suggest that cervical nerve root avulsions can be successfully visualized at 1.5 T in patients with BPI despite the anatomical complexity and susceptibility and motion artifacts. We propose that DTT is a reliable and reproducible method for the investigation of BPI because it provides a successful anatomical and functional display of neural structures that are not otherwise attainable with conventional studies

Diffusion tensor Imaging and fiber tractography of pediatric posterior fossa malformations

Diffusion tensor imaging (DTI) is an advanced MR imaging technique that provides noninvasive qualitative and quantitative information about the white matter microarchitecture. DTI and fiber tractography have been increasingly used in the past decade to investigate the microstructural neuroarchitecture of posterior fossa malformations. This article aimed to review DTI and fiber tractography findings in several posterior fossa malformations, and highlighted the added value of DTI and fiber tractography compared with conventional MR imaging. DTI and fiber tractography may provide information that is helpful to better understand the pathogenesis of selected posterior fossa malformations. In addition, DTI may elucidate the anatomic role of the cerebellum for neurocognitive functions in children with posterior fossa malformations and DTI scalars of the cerebellar, and brain stem white matter tracts may serve as a predictive biomarker for cognitive outcome. Finally, quantitative DTI analysis of cerebellar and brain stem white matter tracts may help to select candidates for therapeutic interventions and may enable monitoring of the therapy response. Learning Objective: To recognize the utility of diffusion tensor imaging and fiber tractography to study malformations of the posterior fossa and highlight the additional information that diffusion tensor imaging and fiber tractography may provide compared with conventional MR imaging sequences

Cerebellar agenesis: An extreme form of cerebellar disruption in preterm neonates

Cerebellar agenesis (CA) may result from both a genetically mediated as well as a disruptive etiology. In preterm neonates, the cerebellum is highly susceptible to injury. Different neuroimaging findings have been reported in disrupted cerebellar development in preterm neonates. We report the association of CA and severe periventricular leukomalacia in a 7-year-old girl with spastic tetraparesis, profound cognitive impairment, epileptic seizures and posthemorrhagic hydrocephalus who was born at 25 wk of gestation. The neuroimaging studies performed during the first wk of life had shown a normal structure of the cerebellum and brainstem confirming a disruptive, rather than a malformative etiology. CA is the most severe form of cerebellar disruption in preterm neonates. Differentiation between malformative and disruptive etiologies of CA is important for prognosis and genetic counseling of the affected children and their families