Effect of vitamin B12 deficiency anemia on peripapillary retinal nerve fiber layer

AIM: To evaluate the effect of vitamin B12 deficiency anemia (BDA) on peripapillary retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT), and to determine any correlation arising thereof. METHODS: In this cross-sectional observational study, 99 eyes of 50 BDA patients of age 18-65y were compared with 100 eyes of 50 healthy control subjects. All subjects underwent comprehensive clinical, ophthalmic, and hematological evaluation, followed by peripapillary RNFLT assessment using SD-OCT. RESULTS: The mean total, inferior, nasal, and temporal RNFLT were significantly lower in BDA group as compared to control group (P<0.05). The mean total, inferior and nasal RNFLT correlated significantly (P<0.05) with serum Hb%, B12 and mean corpuscular volume (MCV) level (r=0.310, 0.435, -0.386 for total; r=0.932, 0.481, -0.513 for inferior; r=0.344, 0.254, -0.233 for nasal; respectively), while temporal and superior RNFLT quadrant did not show any correlation with any of the hematological parameters (r=0.144, 0.167, -0.096; r=0.111, 0.070, -0.099; respectively). The mean total RNFLT showed progressive thinning at par with the progression of anemia, except in very severe BDA, where an inverse relationship was documented. CONCLUSION: The mean total, inferior, nasal, and temporal peripapillary RNFLT was significantly thinner in BDA patients. Peripapillary RNFLT thinning seemed to proceed at par with the progression of severity of anemia, except in very sever grade. Early assessment of peripapillary RNFLT may be crucial in BDA patients to prevent potential blinding sequelae. Peripapillary RNFLT thinning in BDA patients should be considered in the differential diagnosis of other non-glaucomatous optic neuropathies, as well.     

Diagnostic and therapeutic endonasal rhinologic procedures generating aerosol during COVID-19 pandemic: a systematized review

IntroductionMost rhinologic procedures, particularly endoscopic sinonasal procedures, are liable to produce aerosols. The severe acute respiratory syndrome coronavirus 2 (SARS-Co V-2) transmits via respiratory droplets, but the degree of its spread through airborne routes by aerosol is unclear.ObjectiveThe aim of this article is to counsel rhinologists on how to modify their conventional practice during the COVID-19 pandemic by prioritising the need of procedures, identifying aerosol- generating procedures and using precise personal protection equipment for various endonasal procedures.MethodsWe did a review of articles indexed for MEDLINE on PubMed, ENT Cochrane, DOAJ and Web of Science databases using the keywords nasal endoscopy, SARS‐CoV‐2, COVID‐19, aerosol generating medical procedures and rhinology to formulate guidelines for the safety of healthcare workers.ResultsThe review included evidence from 28 articles from the otorhinolaryngology, surgery, infectious disease, head and neck surgery and cancer biology literature. We have provided recommendations and relevant information for rhinologists during the COVID-19 pandemic, based on the available studies and data, to warrant high-quality patient care and requisite levels of infection prevention during rhinology procedures.ConclusionIn rhinology, marked care is advised during nasal packing, electrocauterisation and use of high-speed rotating devices in potentially infected tissue as they are considerable aerosol- producing procedures. The choice of personal protective equipment is based on the risk of exposure and possible modes of aerosol generation.     

Distinct functions for the catalytic and hemopexin domains of a Drosophila matrix metalloproteinase

Human matrix metalloproteinases (MMPs) are believed to contribute to tumor progression. Therapies based on inhibiting the catalytic domain of MMPs have been unsuccessful, but these studies raise the question of whether other MMP domains might be appropriate targets. The genetic dissection of domain function has been stymied in mouse because there are 24 related and partially redundant MMP genes in the mouse genome. Here, we present a genetic dissection of the functions of the hemopexin and catalytic domains of a canonical MMP in Drosophila melanogaster, an organism with only 2 MMPs that function nonredundantly. We compare the phenotypes of Mmp1 null alleles with alleles that have specific hemopexin domain lesions, and we also examine phenotypes of dominant-negative mutants. We find that, although the catalytic domain appears to be required for all MMP functions including extracellular matrix remodeling of the tracheal system, the hemopexin domain is required specifically for tissue invasion events later in metamorphosis but not for tracheal remodeling. Thus, we find that this MMP hemopexin domain has an apparent specialization for tissue invasion events, a finding with potential implications for inhibitor therapies.     

Regional heart motion abnormality detection: An information theoretic approach

Tracking regional heart motion and detecting the corresponding abnormalities play an essential role in the diagnosis of cardiovascular diseases. Based on functional images, which are subject to noise and segmentation/registration inaccuracies, regional heart motion analysis is acknowledged as a difficult problem and, therefore, incorporation of prior knowledge is desirable to enhance accuracy. Given noisy data and a nonlinear dynamic model to describe myocardial motion, an unscented Kalman smoother is proposed in this study to estimate the myocardial points. Due to the similarity between the statistical information of normal and abnormal heart motions, detecting and classifying abnormality is a challenging problem. We use the Shannon’s differential entropy of the distributions of potential classifier features to detect and locate regional heart motion abnormality. A naive Bayes classifier algorithm is constructed from the Shannon’s differential entropy of different features to automatically detect abnormal functional regions of the myocardium. Using 174 segmented short-axis magnetic resonance cines obtained from 58 subjects (21 normal and 37 abnormal), the proposed method is quantitatively evaluated by comparison with ground truth classifications by radiologists over 928 myocardial segments. The proposed method performed significantly better than other recent methods, and yielded an accuracy of 86.5% (base), 89.4% (mid-cavity) and 84.5% (apex). The overall classification accuracy was 87.1%. Furthermore, standard kappa statistic comparisons between the proposed method and visual wall motion scoring by radiologists showed that the proposed algorithm can yield a kappa measure of 0.73.     

Localization of the full‐thickness cartilage lesions in medial and lateral unicompartmental knee osteoarthritis

This study's aim was to determine the patterns of osteoarthritis (OA) in both unicompartmental medial and lateral OA of the knee. Forty patients with medial and 20 with lateral unicompartmental knee osteoarthritis were studied to determine the location of full‐thickness cartilage lesions. Intraoperatively, the distance between margins of the lesion and reference lines were measured. The femoral measurements were transposed onto lateral radiographs to determine the relationship between the lesion site and knee flexion angles. Both tibial and femoral lesions were significantly (p < 0.01) more posterior in lateral OA than medial OA. In medial OA, the lesion center was, on average, at 11° (SD 3°) of flexion, whereas in lateral OA, it was at 40° (SD 3°). The smallest medial femoral lesions were near full extension and, as they enlarged, they extended posteriorly. The smallest lateral femoral lesions extended from 20° to 60° flexion. As these lesions enlarged, they extended both anteriorly and posteriorly. There was a well‐defined relationship between the site of the lesions and their size, suggesting that they develop and progress in a predictable manner. The relationship was different for medial and lateral OA, suggesting that different mechanical factors are important in initiating the different types of OA. The lesions in medial OA occur in extension, perhaps initiated by events occurring at heel strike. The lesions in lateral OA begin at flexion angles above those occurring during the single leg stance phase of the gait cycle, so activities other than gait are likely to induce lateral OA. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1339–1346, 2009     

VIPdb,a genetic Variant Impact Predictor Database

Genome sequencing identifies vast number of genetic variants. Predicting these variants’ molecular and clinical effects is one of the preeminent challenges in human genetics. Accurate prediction of the impact of genetic variants improves our understanding of how genetic information is conveyed to molecular and cellular functions, and is an essential step towards precision medicine. Over one hundred tools/resources have been developed specifically for this purpose. We summarize these tools as well as their characteristics, in the genetic Variant Impact Predictor Database (VIPdb). This database will help researchers and clinicians explore appropriate tools, and inform the development of improved methods. VIPdb can be browsed and downloaded at https://genomeinterpretation.org/vipdb.     

Identification of Human Case of Avian Influenza A(H5N1) Infection,India

A 11-year-old boy with acute myeloid leukemia was brought for treatment of severe acute respiratory infection in the National Capital Region, New Delhi, India. Avian influenza A(H5N1) infection was laboratory confirmed. Complete genome analysis indicated hemagglutinin gene clade 2.3.2.1a. We found the strain to be susceptible to amantadine and neuraminidase inhibitors.     

Intraspinal MDL28170 microinjection improves functional and pathological outcome following spinal cord injury

Although calpain (calcium-activated cysteine protease) inhibition represents a rational therapeutic target for spinal cord injury (SCI), few studies have reported improved functional outcomes with post-injury administration of calpain inhibitors. This reflects the weak potency and limited aqueous solubility of current calpain inhibitors. Previously, we demonstrated that intraspinal microinjection of the calpain inhibitor MDL28170 resulted in greater inhibition of calpain activity as compared to systemic administration of the same compound. In the present study, we evaluated the ability of intraspinal MDL28170 microinjection to spare spinal tissue and locomotor dysfunction following SCI. Contusion SCI was produced in female Long-Evans rats using the Infinite Horizon impactor at the 200-kdyn force setting. Open-field locomotion was evaluated until 6 weeks post-injury. Histological assessment of tissue sparing was performed at 6 weeks after SCI. The results demonstrate that MDL28170, administered with a single post-injury intraspinal microinjection (50 nmoles), significantly improves both locomotor function and pathological outcome measures following SCI.