Acute Pulmonary Embolism Following Baker's Cyst Excision - A Life Threatening Complication: A Case Report

A 55-year-old women was diagnosed with Baker's cyst and underwent open Baker's cyst excision. She had developed acute pulmonary embolism in the post-operative period. Our case report is to emphasise the sub-clinical concomitant deep vein thrombosis with Baker's cyst. Such a fatal complication has not been reported in literature and preventive measures of pre-operative venous Doppler and post-operative thrombo-prophylaxis can prevent them.

Major implications of single nucleotide polymorphisms in human carboxylesterase 1 on substrate bioavailability

The number of studies and reviews conducted for the Carboxylesterase gene is limited in comparison with other enzymes. Carboxylesterase (CES) gene or human carboxylesterases (hCES) is a multigene protein belonging to the α/β-hydrolase family. Over the last decade, two major carboxylesterases (CES1 and CES2), located at 16q13-q22.1 on human chromosome 16 have been extensively studied as important mediators in the metabolism of a wide range of substrates. hCES1 is the most widely expressed enzyme in humans, and it is found in the liver. In this review, details regarding CES1 substrates include both inducers (e.g. Rifampicin) and inhibitors (e.g. Enalapril, Diltiazem, Simvastatin) and different types of hCES1 polymorphisms (nsSNPs) such as rs2244613 and rs71647871. along with their effects on various CES1 substrates were documented. Few instances where the presence of nsSNPs exerted a positive influence on certain substrates which are hydrolyzed via hCES1, such as anti-platelets like Clopidogrel when co-administered with other medications such as angiotensin-converting enzyme (ACE) inhibitors were also recorded. Remdesivir, an ester prodrug is widely used for the treatment of COVID-19, being a CES substrate, it is a potent inhibitor of CES2 and is hydrolyzed via CES1. The details provided in this review could give a clear-cut idea or information that could be used for further studies regarding the safety and efficacy of CES1 substrate.

Describing the Structural Phenotype of the Glaucomatous Optic Nerve Head Using Artificial Intelligence

PURPOSE

To develop a novel deep-learning approach that can describe the structural phenotype of the glaucomatous optic nerve head (ONH) and can be used as a robust glaucoma diagnosis tool.

DESIGN

Retrospective, deep-learning approach diagnosis study.

METHOD

We trained a deep-learning network to segment 3 neural-tissue and 4 connective-tissue layers of the ONH. The segmented optical coherence tomography images were then processed by a customized autoencoder network with an additional parallel branch for binary classification. The encoder part of the autoencoder reduced the segmented optical coherence tomography images into a low-dimensional latent space (LS), whereas the decoder and the classification branches reconstructed the images and classified them as glaucoma or nonglaucoma, respectively. We performed principal component analysis on the latent parameters and identified the principal components (PCs). Subsequently, the magnitude of each PC was altered in steps and reported how it impacted the morphology of the ONH.

RESULTS

The image reconstruction quality and diagnostic accuracy increased with the size of the LS. With 54 parameters in the LS, the diagnostic accuracy was 92.0 ± 2.3% with a sensitivity of 90.0 ± 2.4% (at 95% specificity), and the corresponding Dice coefficient for the reconstructed images was 0.86 ± 0.04. By changing the magnitudes of PC in steps, we were able to reveal how the morphology of the ONH changes as one transitions from a "nonglaucoma" to a "glaucoma" condition.

CONCLUSIONS

Our network was able to identify novel biomarkers of the ONH for glaucoma diagnosis. Specifically, the structural features identified by our algorithm were found to be related to clinical observations of glaucoma.

The three-dimensional structural configuration of the central retinal vessel trunk and branches as a glaucoma biomarker

PURPOSE

To assess whether the 3-dimensional (3D) structural configuration of the central retinal vessel trunk and its branches (CRVT&B) could be used as a diagnostic marker for glaucoma.

DESIGN

Retrospective, deep-learning approach diagnosis study.

METHODS

We trained a deep learning network to automatically segment the CRVT&B from the B-scans of the optical coherence tomography (OCT) volume of the optic nerve head. Subsequently, 2 different approaches were used for glaucoma diagnosis using the structural configuration of the CRVT&B as extracted from the OCT volumes. In the first approach, we aimed to provide a diagnosis using only 3D convolutional neural networks and the 3D structure of the CRVT&B. For the second approach, we projected the 3D structure of the CRVT&B orthographically onto sagittal, frontal, and transverse planes to obtain 3 two-dimensional (2D) images, and then a 2D convolutional neural network was used for diagnosis. The segmentation accuracy was evaluated using the Dice coefficient, whereas the diagnostic accuracy was assessed using the area under the receiver operating characteristic curves (AUCs). The diagnostic performance of the CRVT&B was also compared with that of retinal nerve fiber layer (RNFL) thickness (calculated in the same cohorts).

RESULTS

Our segmentation network was able to efficiently segment retinal blood vessels from OCT scans. On a test set, we achieved a Dice coefficient of 0.81 ± 0.07. The 3D and 2D diagnostic networks were able to differentiate glaucoma from nonglaucoma subjects with accuracies of 82.7% and 83.3%, respectively. The corresponding AUCs for the CRVT&B were 0.89 and 0.90, higher than those obtained with RNFL thickness alone (AUCs ranging from 0.74 to 0.80).

CONCLUSIONS

Our work demonstrated that the diagnostic power of the CRVT&B is superior to that of a gold-standard glaucoma parameter, that is, RNFL thickness. Our work also suggested that the major retinal blood vessels form a "skeleton"-the configuration of which may be representative of major optic nerve head structural changes as typically observed with the development and progression of glaucoma.

Towards label-free 3D segmentation of optical coherence tomography images of the optic nerve head using deep learning

Recently proposed deep learning (DL) algorithms for the segmentation of optical coherence tomography (OCT) images to quantify the morphological changes to the optic nerve head (ONH) tissues during glaucoma have limited clinical adoption due to their device specific nature and the difficulty in preparing manual segmentations (training data). We propose a DL-based 3D segmentation framework that is easily translatable across OCT devices in a label-free manner (i.e. without the need to manually re-segment data for each device). Specifically, we developed 2 sets of DL networks: the 'enhancer' (enhance OCT image quality and harmonize image characteristics from 3 devices) and the 'ONH-Net' (3D segmentation of 6 ONH tissues). We found that only when the 'enhancer' was used to preprocess the OCT images, the 'ONH-Net' trained on any of the 3 devices successfully segmented ONH tissues from the other two unseen devices with high performance (Dice coefficients > 0.92). We demonstrate that is possible to automatically segment OCT images from new devices without ever needing manual segmentation data from them.

The Blood Brain Barrier and its Role in Alzheimer's Therapy: An Overview

BACKGROUND

Alzheimer's disease (AD) is the most frequent age related neurodegenerative disorder. It represents 70% of all dementia. Millions of people have been affected by AD worldwide. It is a complex illness characterized pathologically by accumulation of protein aggregates of amyloid and neurofibrillary tangles containing hyperphosphorylated neuronal tau protein. AD requires drugs that can circumvent the blood-brain barrier (BBB) which is not a simple physical barrier between blood and brain, but acts as an iron curtain, allowing only selective molecules to enter the brain. Unfortunately, this dynamic barrier restricts transport of drugs to the brain; due to which, currently very few drugs are available for AD treatment.

OBJECTIVE

The present review focuses mainly on strategies used for administration of drug to the CNS by-passing BBB for the treatment of AD.

RESULTS

Many studies have proved to be effective in overcoming BBB and targeting drugs to CNS by using different strategies. Here we have discussed some of the most important drug permeability and drug targeting approaches.

CONCLUSION

In conclusion, concentrating solely in development of drug discovery programs is not enough but it is important to maintain balance between the drug discovery and drug delivery systems that are more specific and effective in targeting CNS of AD patients.

DRDO E-Journal Consortium in Defence Science and Technology

<p>Defence Research and Development Organisation (DRDO) E-Journal Consortium is one of the important consortiums among other consortia existing in India. It covers multi-disciplinary subject areas to fulfill the information needs of DRDO scientific community. This paper tries to evaluate the implementation of DRDO e-journals, coverage of publishers and titles, subject-wise distribution of titles among DRDO laboratories, need of e-journal consortium among the labs, and expenditure details along with yearly growth. This is one of the unique consortiums implemented that is based on subscription model.The study also highlights the usage of e- journals publisher-wise in the consortium and would be helpful in efficient collection development policy of e-journals.</p>

Structure-Activity Relationship Studies of N- and C-Terminally Modified Secretin Analogs for the Human Secretin Receptor

The pleiotropic role of human secretin (hSCT) validates its potential use as a therapeutic agent. Nevertheless, the structure of secretin in complex with its receptor is necessary to develop a suitable therapeutic agent. Therefore, in an effort to design a three-dimensional virtual homology model and identify a peptide agonist and/or antagonist for the human secretin receptor (hSR), the significance of the primary sequence of secretin peptides in allosteric binding and activation was elucidated using virtual docking, FRET competitive binding and assessment of the cAMP response. Secretin analogs containing various N- or C-terminal modifications were prepared based on previous findings of the role of these domains in receptor binding and activation. These analogs exhibited very low or no binding affinity in a virtual model, and were found to neither exhibit in vitro binding nor agonistic or antagonistic properties. A parallel analysis of the analogs in the virtual model and in vitro studies revealed instability of these peptide analogs to bind and activate the receptor.

Design and development of hydrogel nanoparticles for mercaptopurine

Hydrogel nanoparticles have gained attention in recent years as they demonstrate the features and characters of hydrogels and nanoparticles at the same time. In the present study chitosan and carrageenan have been used, as hydrogel nanoparticles of mercaptopurine are developed using natural, biodegradable, and biocompatible polymers like chitosan and carrageenan. As these polymers are hydrophilic in nature, the particles will have a long life span in systemic circulation. Hydrogel nanoparticles with mercaptopurine is form an antileukemia drug by the counter polymer gelation method. Fourier-Transform Infrared (FT-IR) studies have shown a compatibility of polymers with the drug. The diameter of hydrogel nanoparticles was about 370 – 800 nm with a positive zeta potential of 26 – 30 mV. The hydrogel nanoparticles were almost spherical in shape, as revealed by scanning electron microscopy (SEM). Drug loading varied from 9 to 17%. Mercaptopurine released from the nanoparticles at the end of the twenty-fourth hour was about 69.48 – 76.52% at pH 7.4. The drug release from the formulation was following zero order kinetics, which was evident from the release kinetic studies and the mechanism of drug release was anomalous diffusion, which indicated that the drug release was controlled by more than one process.

Dual epidermal growth factor receptor (EGFR)/insulin-like growth factor-1 receptor (IGF-1R) inhibitor: a novel approach for overcoming resistance in anticancer treatment

Small molecule inhibitors of epidermal growth factor receptors (EGFR) have been found to show a good initial response in cancer patients but during the course of treatment, patients develop resistance after a few weeks of time. Development of secondary mutations or over-activation of insulin like growth factor (IGF-1R) pathway are a few of the several mechanisms proposed to explain the resistance. To study the effect of dual inhibition of EGFR and IGF-1R in overcoming the resistance, three strategies were envisaged and are reported in this manuscript: 1) a virtual predictive tumor model, 2) in vitro experimental data using a combination of EGFR and IGF-1R inhibitors and 3) in vitro experimental data using in house dual inhibitors. Findings reported in this manuscript suggest that simultaneous inhibition of IGF-1R and EGFR either by combination of two inhibitors or by dual kinase inhibitors is more efficacious compared to single agents. In vitro cell based experiments conducted using epidermoid cancer cell line, A431 and an EGFR mutant cell line, H1975 along with virtual predictions reported here suggests that dual inhibition of EGFR and IGF-1R is a viable approach to overcome EGFR resistance.

Studies on the Preparation and Evaluation of Chitosan Nanoparticles containing Cytarabine

The activity of cytarabine was decreased by its rapid deamination to the biologically inactive metabolite uracil arabinoside. This rapid deamination is the reason for the ongoing research for effective formulation of cytarabine that can not be deaminated and exhibit better pharmacokinetic parameters. Protection of cytarabine from fast degradation and elimination was investigated by encapsulating the drug into chitosan nanoparticles. Cytarabine loaded nanoparticles prepared by ionotropic gelation were characterized by SEM and was found to in the range of 200 nm.The mechanism by which drug is being released is non-Fickian(anomalous) solute diffusion mechanism. It is evident from the result that initial burst release was retarded or delayed due to adsorption of coating material. The in vivo biodistribution study results showed that the nanoparticles were having better distribution of drug compared to free drug in different organs like spleen, lungs, kidney etc.

Withanolide induces apoptosis in HL-60 leukemia cells via mitochondria mediated cytochrome c release and caspase activation

The present study is on the growth inhibitory effect of Withania somnifera methanolic leaf extract and its active component, withanolide on HL-60 promyelocytic leukemia cells. The decrease in survival rate of HL-60 cells was noted to be associated with a time dependent decrease in the Bcl-2/Bax ratio, leading to up regulation of Bax. Both the crude leaf extract and the active component activated the apoptotic cascade through the cytochrome c release from mitochondria. The activation of caspase 9, caspase 8 and caspase 3 revealed that caspase was a key mediator in the apoptotic pathway. DNA fragmentation analysis revealed typical ladders as early as 12h indicative of caspase 3 role in the apoptotic pathway. Flow cytometry data demonstrated an increase of sub-G1 peak upon treatment by 51% at 24h, suggesting the induction of apoptotic cell death in HL-60 cells.

Evaluating organic compound migration in poly(ethylene terephthalate): a simple test with implications for polymer recycling

The safety of recycled plastics for food contact use is largely dictated by the ability of post-consumer organic contaminants to absorb into recycled materials and later diffuse from containers made from recycled plastics into the food supply. Diffusion and solubility data for organic contaminants in poly(ethylene terephthalate) (PET) are scarce. An approach for determining permeability constants, diffusion coefficients and solubility constants of slowly migrating contaminants in PET is described. Compounds (neat or in admixture) were heat-sealed in packets made from thin (0.00127 cm) PET films. Packets were placed in containers with GC sampling closures. Headspace (volatile compounds) or an external liquid medium (non-volatile compounds) was analysed for emergence of the compound. Diffusion coefficients were determined from non-steady state diffusion equations, permeability constants were determined from steady state permeation, and solubility constants were calculated from diffusion and permeability values. Diffusion coefficients (25 degrees C) ranged from 10(-9) to < 10(-16) cm2/s. The diffusion coefficient of benzene increased dramatically with concentration. Compounds with high permeation increased the transport rate of slower permeating volatiles.

Type B dissection involving a right-sided aortic arch

Type B dissection involving a right-sided aortic arch is a very rare condition. Here we describe such an occurrence in an elderly patient who was initially managed medically but later underwent successful surgical repair after developing symptoms of expanding dissection. The dissection was approached through a right thoracotomy. Because of the unusual origin of the arch vessels and the direction of the dissected segment, aortic clamps could not be positioned satisfactorily, necessitating the use of full cardiopulmonary bypass and deep hypothermic circulatory arrest for the repair. The indications for surgery in Type B dissection and the modifications in the surgical strategy necessitated by the abnormal anatomy are discussed.

Diffuse optics determination of hemoglobin derivatives in red blood cells and liposome encapsulated hemoglobin

High resolution optical absorption spectra of hemoglobin derivatives in red blood cells and phosphatidylcholine liposomes were calculated from diffuse reflection and transmission spectra by means of the one-dimensional diffusion approximation. The numerical technique of singular value decomposition was used to calculate the composition of red cell and liposome mixtures.

Hypericin photosensitization in aqueous model systems

Photosensitization of lysozyme, liposomes, ghosts and intact red blood cells (RBC) was investigated for aqueous hypericin. The effects of azide ion, 1,4-diazabicyclo(2.2.2)octane, and superoxide dismutase on photosensitized inactivation of lysozyme in 0.5% Triton X-100 indicate that singlet oxygen is the major inactivating intermediate with a contribution from superoxide. The singlet oxygen quantum yield (phi delta) scaled to methylene blue is 0.49 +/- 0.06 at monochromatic wavelengths from 514 to 600 nm. Relative values of phi delta based on lysozyme inactivation for different vehicles are: 0.5% Triton X-100 (1.13), human serum albumin (0.65), Cremophor-EL (0.76), Cremophor-RH40 (0.98), egg phosphatidylcholine (EPC) liposomes (0.04), hydrogenated soy phosphatidylcholine (HSPC) liposomes (< 0.01). Hypericin photosensitized lipid peroxidation of EPC liposomes and RBC ghosts. Extensive cross-linking of ghost membrane proteins occurred during the initial stages of lipid peroxidation. Prompt photohemolysis was used as the assay of RBC membrane damage. The photohemolysis curves are modeled with multihit target theory based on the "hit number" (n) and the target cross section (v). The values of v and the conventional "1/t50" parameter are equivalent determinants of the photohemolysis rate. The photohemolysis curves are in good agreement with n = 15 for incubation in phosphate-buffered saline at different hypericin concentrations and with additives. The measurements for other vehicles led to n = 19 for Cremophor-EL and n = 3 for EPC and HSPC liposomes, indicating that the kinetics of photohemolysis depend on the conditions of incubation.

Photosensitization of aqueous model systems by hypericin

Absorption and fluorescence measurements of purified hypericin (HY) were made in various media. Photosensitization of two aqueous systems was investigated: resealed red blood cell membranes (ghosts) and hen lysozyme (Lys). Solubilization of HY by ghost membranes was shown by means of diffuse reflectance spectroscopy. Visible light irradiation of the ghosts incorporating HY led to lipid peroxidation with evidence of singlet oxygen involvement. A binding model applicable for insoluble ligands is indicative of strong HY binding to HSA. The HY-HSA complex photosensitized inactivation of Lys. The pseudo-first-order reaction kinetics with protection by azide ion are consistent with a Type II mechanism mediated by singlet oxygen. The results are discussed in the context of the HY photodynamic and antiretroviral activities.