Anti-phytoviral Activity of Carvacrol vis-a-vis Cauliflower Mosaic Virus (CaMV)

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Viruses are causative agents of infections in plants which are found worldwide and cause a serious threat to...     

Managing therapy-associated neurotoxicity in children with ALL

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Analysis of 55 cases of adenomatoid odontogenic tumor in an Indian population and review of literature

Background This study reviews the demographic, clinical and radiographic features of adenomatoid odontogenic tumor(AOT) diagnosed in an Indian population over 50 years and also evaluate and compare follicular AOT(F-AOT) and extra-follicular AOT(EF-AOT).Material and Methods 55 diagnosed cases of AOT from 1971-2020 were studied retrospectively. The data regarding the age, sex, location, variant of AOT, duration, clinical features, radiographic appearance, treatment and recurrence were collected and analysed.Results Of the 722 odontogenic tumors diagnosed, 7.6% were AOTs with higher prevalence of extra-follicular (67.3%) than follicular (32.7%) variant. All the tumors were intraosseous with a marked predilection for maxilla over mandible, ratio 2:1. The patients mean age was 19.8 years with slightly higher female predilection (male:female ratio - 1:1.5). The anterior region (76.4%) was more frequently affected and entire quadrant was involved in 21.8% cases. Clinically, asymptomatic, slow-growing swelling was seen in 81.8% cases with duration of 15 days to 10 years. Radiographically, AOT appeared as well-corticated radiolucent lesion. Canine was the most commonly impacted tooth. Recurrence was seen in 3 cases.Conclusions Interestingly, in this series extra-follicular was twice more common than follicular AOT. Few cases involved the entire quadrant or crossed the midline of either jaws. Key words:Adenomatoid odontogenic tumor (AOT), follicular AOT, extrafollicular AOT, Indian population, odontogenic tumor.     

Orbital dermoid cyst

Background:Dermoid cyst, a developmental benign choristoma, is the most common orbital tumor of childhood, arising from ectodermal sequestration along the lines of embryonic fusion of mesodermal processes, lined by keratinized stratified squamous epithelium and expanding slowly due to constant desquamation and dermal glandular elements. Approximately 80% are found in the head and neck region and comprise 3-9% all orbital masses.Purpose:It is mandatory to know about the variable presentations of orbital dermoids and the surgical techniques that can be adopted based on the site, extent, age and aesthetic needs, presence of inflammation and possibility of intraoperative rupture.Synopsis:Orbital dermoids can be classified as juxta-sutural, sutural or soft tissue cysts; superficial or deep; intraosseous or extraosseous, and intraorbital or extraorbital. These smooth, painless, mobile or partially mobile lesions mostly present at the fronto-zygomatic suture with proptosis, displacement, ptosis or diplopia, depending on depth and extent. Therefore, it is important to understand the various presentations and the appropriate surgical techniques.Highlights:We describe the embryological origin, types and clinical features of dermoids in this video and demonstrate the surgical and minimally invasive techniques for their management.Video link: https://youtu.be/-q3xD2igjcQ     

Neuroanatomical correlates of intellectual ability across the life span

Attempts to correlate measures of intellectual ability with localized anatomical imaging features of the brain have yielded variable findings distributed across frontal, parietal, and temporal lobes. To better define the gray and white matter correlates of intellectual ability and the effects of sex and age, we analyzed the brains of 105 healthy individuals, ages 7-57 years, who had a Full Scale Intelligence Quotient (FSIQ) of 70 or higher. We examined associations of FSIQ with cortical thickness and with white matter volume throughout the cerebrum. Thinning of left ventromedial and right dorsolateral prefrontal cortices correlated significantly with FSIQ. Sex modified correlations of cortical thickness with FSIQ in the left inferior frontal, left cingulate, and right dorsomedial prefrontal cortices. Correlations of local white matter volumes with FSIQ varied by age, with adults showing inverse correlations of white matter volume with FSIQ in a large territory of right frontal white matter likely corresponding to fiber tracts of the superior corona radiata and superior longitudinal fasciculus. These findings corroborate the role of frontal and parietal association cortices and long association white matter fibers in higher intelligence and suggest ways in which the neuroanatomical correlates of higher intelligence may vary by sex and age.     

The effect of mutation in the stem of the MicroROSE thermometer on its thermosensing ability: insights from molecular dynamics simulation studies

A large number of bacteria have been found to govern virulence and heat shock responses using temperature sensing RNAs known as RNA thermometers (RNATs). They repress translation initiation by base pairing to the Shine–Dalgarno (SD) sequence at low temperature. Increasing the temperature induces the RNA duplex to unfold and expose the SD sequence for translation. A prime example is the ROSE thermometer module known to regulate the production of the ROSE heat shock protein in Bradyrhizobium japonicum. The unfolding of a 29-nucleotide long MicroROSE RNA element which forms a critical component encompassing the SD sequence, and three mutants that differ from it by deletion of a guanine nucleotide or mutations near the SD and stem regions have been studied using high temperature molecular dynamics simulations. The simulations reveal the progressive manner in which a biologically functional RNA thermometer unfolds. Our simulations reveal that deletion of the highly conserved G10 residue, opposite to the SD region leads to the formation of a stable RNA helix that has lost its thermosensing ability. Mutations of bases A5 → U5 and U25 → A25 near the stem increase the thermosensing ability due to the allosteric effect which leads to a global destabilization effect on the structure. The temperature-dependant regulation of this thermometer has been investigated by estimation of differences in the unfolding paths by calculating individual residue fluctuation, stacking energy, the contact map plot and the lifetime dynamics plot of non-Watson–Crick hydrogen bonds at three different temperatures. Results reveal that partial unfolding at higher temperature starts from the hairpin tetra loop end and terminates at the stem region through the SD associated region. Two canonical hydrogen bonds between U9–A22 and four non-canonical hydrogen bonds between G10–G21 and U6–U24 around the internal loop play an important role in partial melting of the RNA helix. These results demonstrate how small alterations in RNA structure can regulate gene expression and illuminate the molecular basis of the function of an important bacterial regulatory motif.

Mutation induced thermosensing ability of MicroROSE thermometer.     

Kinetics and Characterization of Non-enzymatic Fragmentation of Monoclonal Antibody Therapeutics

Purpose

To understand non-enzymatic hydrolytic fragmentation of a monoclonal antibody therapeutic under temperature stressed conditions and investigating possible mechanism for the same.

Methods

The mAb therapeutic was incubated at 50°C in phosphate buffer at pH 6.5 and fragmentation was monitored at different ionic strengths under stressed conditions. The incubated mAb was sampled at regular time intervals by analytical Size Exclusion Chromatography (SEC).

Results

It was observed that 57% of the mAb product fragmented over 4 days into two fragment species – Fc-Fab and Fab with molecular weights of 97 KDa and 47 KDa, respectively, as measured by mass spectrometry (MS) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The fragmentation rate was slow initially and then accelerated with time. No change in % aggregate level was observed in this duration, implying that degradation was primarily via fragmentation at high temperature. Kinetics of hydrolytic fragmentation was hypothesized and SEC data was fitted to estimate the kinetic rate constants. While degradation of the monomer into fragment species was non-Arrhenius with a negative activation energy, further degradation of Fab-Fc fragments into Fab or Fc fragments followed Arrhenius Law with an activation energy of 2.1 and 15.38 kcal/mol, respectively.

Conclusion

High temperature (50°C) causes mAb to cleave at the hinge region to form Fab-Fc and Fab/Fc, as confirmed by dynamic light scattering, SDS-PAGE, SEC, and MS. A kinetic model for hydrolytic fragmentation has been proposed. The results are expected to assist end users in formulation development as well as in monitoring stability of biotherapeutic products.