Handheld chromatic pupillometry can accurately and rapidly reveal functional loss in glaucoma

Background/aimsEarly detection and treatment of glaucoma can delay vision loss. In this study, we evaluate the performance of handheld chromatic pupillometry (HCP) for the objective and rapid detection of functional loss in glaucoma.MethodsIn this clinic-based, prospective study, we enrolled 149 patients (median (IQR) years: 68.5 (13.6) years) with confirmed glaucoma and 173 healthy controls (55.2 (26.7) years). Changes in pupil size in response to 9 s of exponentially increasing blue (469 nm) and red (640 nm) light-stimuli were assessed monocularly using a custom-built handheld pupillometer. Pupillometric features were extracted from individual traces and compared between groups. Features with the highest classification potential, selected using a gradient boosting machine technique, were incorporated into a generalised linear model for glaucoma classification. Receiver operating characteristic curve analyses (ROC) were used to compare the performance of HCP, optical coherence tomography (OCT) and Humphrey Visual Field (HVF).ResultsPupillary light responses were altered in glaucoma compared with controls. For glaucoma classification, HCP yielded an area under the ROC curve (AUC) of 0.94 (95% CI 0.91 to 0.96), a sensitivity of 87.9% and specificity of 88.4%. The classification performance of HCP in early-moderate glaucoma (visual field mean deviation (VFMD) > -12 dB; AUC=0.91 (95% CI 0.87 to 0.95)) was similar to HVF (AUC=0.91) and reduced compared with OCT (AUC=0.97; p=0.01). For severe glaucoma (VFMD ≤ -12 dB), HCP had an excellent classification performance (AUC=0.98, 95% CI 0.97 to 1) that was similar to HVF and OCT.ConclusionHCP allows for an accurate, objective and rapid detection of functional loss in glaucomatous eyes of different severities.

Mapping trait versus species turnover reveals spatiotemporal variation in functional redundancy in a plant-pollinator network

Functional overlap between species (redundancy) shapes competitive and mutualistic interactions, determining community responses to perturbations. Most studies view functional redundancy as static, even though individuals within species vary in traits over seasonal or spatial gradients. Consequently, we lack knowledge on trait turnover within species, how functional redundancy spatiotemporally varies, and when and where interaction networks are vulnerable to functional loss. Studying an Arctic bumblebee community, we investigated how body-size turnover with elevation and over a season shapes their host-plant interactions, and test how sensitive networks are to sequentially losing body-size groups. With trait turnover being larger than species, we found: i) late-season networks were less specialised when nodes comprised functionally similar bumblebees; ii) removal of bumblebee-body-size groups over species accelerated coextinction of host plants, with the magnitude varying in space and time. We demonstrate functional redundancy can vary spatiotemporally, and functional loss impacts interaction partners more than expected from species loss alone.

In Vitro Evolution of Cefiderocol Resistance in an NDM-Producing Klebsiella pneumoniae Due to Functional Loss of CirA

Cefiderocol, a newly approved cephalosporin agent with an extensive spectrum of activity against Gram-negative bacteria, binds siderophore and uses its receptors to access the bacterial periplasm. Loss of functional CirA, an iron transporter, has been associated with cefiderocol resistance.

Impact of severe SARS-CoV-2 infection on nutritional status and subjective functional loss in a prospective cohort of COVID-19 survivors

The nutritional sequelae of COVID-19 have not been explored in a large cohort study.ObjectivesTo identify factors associated with the change in nutritional status between discharge and 30 days post-discharge (D30). Secondary objectives were to determine the prevalence of subjective functional loss and severe disability at D30 and their associated factors.MethodsCollected data included symptoms, nutritional status, self-evaluation of food intake, Performance Status (PS) Scale, Asthenia Scale, self-evaluation of strength (SES) for arms and legs at discharge and at D30. An SES <7 was used to determine subjective functional loss. A composite criteria for severe disability was elaborated combining malnutrition, subjective functional loss and PS >2. Patients were classified into three groups according to change in nutritional status between discharge and D30 (persistent malnutrition, correction of malnutrition and the absence of malnutrition).ResultsOf 549 consecutive patients hospitalised for COVID-19 between 1 March and 29 April 2020, 130 died including 17 after discharge (23.7%). At D30, 312 patients were at home, 288 (92.3%) of whom were interviewed. Of the latter, 33.3% were malnourished at discharge and still malnourished at D30, while 23.2% were malnourished at discharge but no longer malnourished at D30. The highest predictive factors of persistent malnutrition were intensive care unit (ICU) stay (OR=3.42, 95% CI: 2.04 to 5.75), subjective functional loss at discharge (OR=3.26, 95% CI: 1.75 to 6.08) and male sex (OR=2.39, 95% CI: 1.44 to 3.97). Subjective functional loss at discharge (76.8%) was the main predictive factor of subjective functional loss at D30 (26.3%) (OR=32.6, 95% CI: 4.36 to 244.0). Lastly, 8.3% had a severe disability, with a higher risk in patients requiring an ICU stay (OR=3.39, 95% CI: 1.43 to 8.06).ConclusionPatients who survived a severe form of COVID-19 had a high risk of persistent malnutrition, functional loss and severe disability at D30. We believe that nutritional support and rehabilitation should be strengthened, particularly for male patients who were admitted in ICU and had subjective functional loss at discharge.Trial registration numberNCT04451694.

Publisher Correction: Diabetic vascular hyperpermeability: optical coherence tomography angiography and functional loss assessments of relationships among retinal vasculature changes

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Complete Loss of CASK Causes Severe Ataxia Through Cerebellar Degeneration

Heterozygous loss of X-linked genes like CASK and MeCP2 (Rett syndrome) causes neurodevelopmental disorders (NDD) in girls, while in boys loss of the only allele of these genes leads to profound encephalopathy. The cellular basis for these disorders remains unknown. CASK is presumed to work through the Tbr1-reelin pathway in neuronal migration. Here we report clinical and histopathological analysis of a deceased 2-month-old boy with a CASK-null mutation. Although smaller in size, the CASK-null human brain exhibits normal lamination without defective neuronal differentiation, migration, or axonal guidance, excluding the role of reelin. The hypoplastic cerebellum instead displayed astrogliosis, a marker for neuronal loss. We therefore hypothesized that cerebellar hypoplasia with CASK loss is a result of early neurodegeneration. We generated a mouse line where CASK is completely deleted (hemizygous and homozygous) from post-migratory neurons in the cerebellum. Data confirm that a small cerebellum in CASK-loss results from post-developmental degeneration of cerebellar granule neurons. We further demonstrate that at least in cerebellum the functional loss with CASK deletion results secondary to degeneration of granule cells rather that any acute molecular functional loss of CASK. Intriguingly, female mice with heterozygous deletion of CASK in the cerebellum did not display any neurodegeneration. We suggest that NDDs like CASK mutation and Rett syndrome are pathologically neurodegenerative; however, random X-chromosome inactivation in the heterozygous mutant girls results in 50% of cells expressing the functional gene, resulting in a non-progressive pathology, whereas complete loss of the only allele in boys leads to unconstrained degeneration and encephalopathy.