14 research outputs found
Application of 3-D Imaging in a Familial Case of Cleidocranial Dysplasia
Cleidocranial dysplasia (CCD) is a
rare inherited disorder affecting dental and skeletal tissues. CCD usually has
an autosomal dominant pattern of inheritance and common clinical features seen
are aplastic or hypoplastic clavicles, late closure of fontanelle, open skull
sutures, retained deciduous teeth, late eruption of permanent teeth and
presence of multiple impacted supernumerary teeth. Here, we present a case of
CCD in a female patient with positive family history. The diagnosis was
confirmed clinically and radiographically. The newer radiographic advancement,
CBCT was used to validate the radiographic findings
Interplay of Ferritin Accumulation and Ferroportin Loss in Ageing Brain: Implication for Protein Aggregation in Down Syndrome Dementia, Alzheimer's, and Parkinson's Diseases.
Iron accumulates in the ageing brain and in brains with neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Down syndrome (DS) dementia. However, the mechanisms of iron deposition and regional selectivity in the brain are ill-understood. The identification of several proteins that are involved in iron homeostasis, transport, and regulation suggests avenues to explore their function in neurodegenerative diseases. To uncover the molecular mechanisms underlying this association, we investigated the distribution and expression of these key iron proteins in brain tissues of patients with AD, DS, PD, and compared them with age-matched controls. Ferritin is an iron storage protein that is deposited in senile plaques in the AD and DS brain, as well as in neuromelanin-containing neurons in the Lewy bodies in PD brain. The transporter of ferrous iron, Divalent metal protein 1 (DMT1), was observed solely in the capillary endothelium and in astrocytes close to the ventricles with unchanged expression in PD. The principal iron transporter, ferroportin, is strikingly reduced in the AD brain compared to age-matched controls. Extensive blood vessel damage in the basal ganglia and deposition of punctate ferritin heavy chain (FTH) and hepcidin were found in the caudate and putamen within striosomes/matrix in both PD and DS brains. We suggest that downregulation of ferroportin could be a key reason for iron mismanagement through disruption of cellular entry and exit pathways of the endothelium. Membrane damage and subsequent impairment of ferroportin and hepcidin causes oxidative stress that contributes to neurodegeneration seen in DS, AD, and in PD subjects. We further propose that a lack of ferritin contributes to neurodegeneration as a consequence of failure to export toxic metals from the cortex in AD/DS and from the substantia nigra and caudate/putamen in PD brain
Structural Basis of the Substrate Specificity of Cytidine Deaminase Superfamily Guanine Deaminase
Guanine
deaminases (GDs) are important enzymes involved in purine
metabolism as well as nucleotide anabolism pathways that exhibit a
high degree of fidelity. Here, the structural basis of the substrate
specificity of GDs was investigated by determining a series of X-ray
structures of NE0047 (GD from <i>Nitrosomonas europaea</i>) with nucleobase analogues and nucleosides. The structures demonstrated
that the interactions in the GD active site are tailor-made to accommodate
only guanine and any substitutions in the purine ring or introduction
of a pyrimidine ring results in rearrangement of the bases in a catalytically
unfavorable orientation, away from the proton shuttling residue E143.
In addition, X-ray structural studies performed on cytidine revealed
that although it binds in an optimal conformation, its deamination
does not occur because of the inability of the enzyme to orchestrate
the closure of the catalytically important C-terminal loop (residues
181–189). Isothermal calorimetry measurements established that
these nucleoside moieties also disrupt the sequential mode of ligand
binding, thereby abrogating all intersubunit communication. Intriguingly,
it was recently discovered that GDs can also serve as endogenous ammeline
deaminases, although it is structurally nonhomologous with guanine.
To understand the mechanism of dual-substrate specificity, the structure
of NE0047 in complex with ammeline was determined to a resolution
of 2.7 Ă…. The structure revealed that ammeline not only fits
in the active site in a catalytically favorable orientation but also
allows for closure of the C-terminal loop
Site-Specific Fluorescence Dynamics To Probe Polar Arrest by Fob1 in Replication Fork Barrier Sequences
Fob1 protein plays
an important role in aging and maintains genomic
stability by avoiding clashes between the replication and transcription
machinery. It facilitates polar arrest by binding to replication fork
barrier (RFB) sites, present within the nontranscribed spacer region
of the ribosomal DNA. Here, we investigate the mechanism of unidirectional
arrest by creating multiple prosthetic forks within the RFB, with
fluorescent adenine analogue 2-aminopurine incorporated site-specifically
in both the “permissible” and “nonpermissible”
directions. The motional dynamics of the RFB-Fob1 complexes analyzed
by fluorescence lifetime and fluorescence anisotropy decay kinetics
shows that Fob1 adopts a clamp-lock model of arrest and causes stronger
perturbation with the bases in the double-stranded region of the nonpermissible-directed
forks over those of the permissible directed ones, thereby creating
a polar barrier. Corroborative thermal melting studies reveal a skewed
distribution of GC content within the RFB sequence that potentially
assists in Fob1-mediated arrest
Evaluation of management practices in rice–wheat cropping system using multicriteria decision-making methods in conservation agriculture
Abstract In this study, we employed two multiple criteria decision-making (MCDM) methods, namely the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and the Analytic Hierarchic Process (AHP), to determine the best management choice for the cultivation of wheat with a regime of conservation agriculture (CA) practices. By combining alternative tillage approaches, such as reduced tillage and zero tillage, with the quantity of crop residues and fertilizer application, we were able to develop the regime of CA practices. The performance of the regimes compared to the conventional ones was then evaluated using conflicting parameters relating to energy use, economics, agronomy, plant protection, and soil science. TOPSIS assigned a grade to each alternative based on how close it was to the ideal solution and how far away it was from the negative ideal solution. However, employing AHP, we determined the weights of each of the main and sub-parameters used for this study using pairwise comparison. With TOPSIS, we found ZERO1 (0% residue + 100% NPK) followed by ZERO4 (50%residue + 100% NPK), and ZERO2 (100% residue + 50% NPK) were the best performing tillage-based alternatives. To best optimize the performance of wheat crops under various CA regimes, TOPSIS assisted the decision-makers in distinguishing the effects of the parameters on the outcome and identifying the potential for maneuvering the weak links. The outcomes of this investigation could be used to improve management techniques for wheat production with CA practices for upscaling among the farmers
Interplay of Ferritin Accumulation and Ferroportin Loss in Ageing Brain: Implication for Protein Aggregation in Down Syndrome Dementia, Alzheimer’s, and Parkinson’s Diseases
Iron accumulates in the ageing brain and in brains with neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and Down syndrome (DS) dementia. However, the mechanisms of iron deposition and regional selectivity in the brain are ill-understood. The identification of several proteins that are involved in iron homeostasis, transport, and regulation suggests avenues to explore their function in neurodegenerative diseases. To uncover the molecular mechanisms underlying this association, we investigated the distribution and expression of these key iron proteins in brain tissues of patients with AD, DS, PD, and compared them with age-matched controls. Ferritin is an iron storage protein that is deposited in senile plaques in the AD and DS brain, as well as in neuromelanin-containing neurons in the Lewy bodies in PD brain. The transporter of ferrous iron, Divalent metal protein 1 (DMT1), was observed solely in the capillary endothelium and in astrocytes close to the ventricles with unchanged expression in PD. The principal iron transporter, ferroportin, is strikingly reduced in the AD brain compared to age-matched controls. Extensive blood vessel damage in the basal ganglia and deposition of punctate ferritin heavy chain (FTH) and hepcidin were found in the caudate and putamen within striosomes/matrix in both PD and DS brains. We suggest that downregulation of ferroportin could be a key reason for iron mismanagement through disruption of cellular entry and exit pathways of the endothelium. Membrane damage and subsequent impairment of ferroportin and hepcidin causes oxidative stress that contributes to neurodegeneration seen in DS, AD, and in PD subjects. We further propose that a lack of ferritin contributes to neurodegeneration as a consequence of failure to export toxic metals from the cortex in AD/DS and from the substantia nigra and caudate/putamen in PD brain
Challenges for maintaining post elimination phase of visceral leishmaniasis control programme in India: A field-based study.
BackgroundIndia is going through the maintenance phase of VL elimination programme which may be threatened by the persistence of hidden parasite pools among asymptomatic leishmanial infection (ALI) and PKDL. The present work was designed to determine the burden of VL, PKDL, and ALI and to assess the role of treatment of ALI in maintaining post-elimination phase.Methods and findingThe study was undertaken in Malda district, West Bengal, India during October 2016 to September 2021. Study areas were divided into 'Study' and 'Control' arms. VL and PKDL cases of both the arms were diagnosed by three active mass surveys with an interval of one year and treated as per National guideline. ALI of 'Study' arm was treated like VL. ALI of 'Control' arm was followed up to determine their fate. Fed sand-fly pools were analysed for parasitic DNA. No significant difference was noted between the incidence of VL and PKDL in both the arms. Incidence of ALI declined sharply in 'Study' arm but an increasing trend was observed in 'Control' arm. Significantly higher rate of sero-conversion was noted in 'Control' arm and was found to be associated with untreated ALI burden. Parasitic DNA was detected in 22.8% ALI cases and 2.2% sand-fly pools.ConclusionPersistence of a significant number of PKDL and ALI and ongoing transmission, as evidenced by new infection and detection of leishmanial DNA in vector sand-flies, may threaten the maintenance of post-elimination phase. Emphasis should be given for elimination of pathogen to prevent resurgence of VL epidemics
Fluorescence Quenching Studies of γ‑Butyrolactone Binding Protein (CprB) from <i>Streptomyces coelicolor</i> A3(2)
Quorum sensing is a cell density
dependent phenomenon that utilizes
small molecule inducers like Îł-butyrolactones (GBLs) and their
receptor proteins for adaptation to the environment. The cognate GBLs
that bind to several of this GBL receptor family of proteins remain
elusive. Here, using CprB protein from <i>Streptomyces coelicolor</i> A3(2) as a model system, we devise a method suited for ligand screening
that would be applicable to the entire family of GBL receptors. Docking
studies were performed to confirm the identity of the ligand binding
pocket, and it was ascertained that the common Îł-butyrolactone
moiety interacts with the conserved tryptophan residue (W127) residing
in the ligand binding pocket. The presence of W127 in the cavity was
exploited to monitor its fluorescence quenching on the addition of
two chemically synthesized GBLs. Analysis of the data with both the
native and W185L mutant versions of the protein confirmed that the
compounds used as quenchers reside in the ligand binding pocket. Furthermore,
fluorescence lifetime and potassium iodide (KI) quenching studies
established that the quenching is static in nature and that the tryptophan
residue is buried and inaccessible to surface quenchers. Additionally,
a combination of concentration dependent fluorescence quenching and
dynamic light scattering experiments revealed that the binding properties
of the protein are concentration dependent and it was concluded that
the most efficient binding of the ligand is evoked by working at the
lowest concentration of protein, providing a sufficient signal, where
the aggregation effects are negligible
Lifetime measurement in Ba and Cs using Doppler Shift Attenuation Method (DSAM)
International audienceThe nuclear structure exhibits transitional behaviour in the A'125 mass region as the nuclei lie between the spherical (Sn, Z=50) and deformed (Ce, Z=58) structures. Here exists a unique parity intruder subshell, h11/2, which can be accessed by both the protons and the neutrons. These h11/2 nucleons have opposite deformation driving effects which lead to an interplay of prolate, oblate or triaxial nuclear shapes[1]
Evidence of fungal decay in petrified legume wood from the Neogene of the Bengal Basin, India
Silicified fossil legume woods of Cynometroxylon Chowdhury & Ghosh collected from the Neogene (late Miocene) sediments of the Bengal Basin, eastern India, exhibit fungal decay seldom found in the fossil record. The wood possesses numerous perforate areas on the surface that seem to be the result of extensive fungal activity. In transverse section, the decayed areas (pockets) appear irregular to ellipsoidal in outline; in longitudinal section these areas of disrupted tissue are somewhat spindle-shaped. Individual pockets are randomly scattered throughout the secondary xylem or are restricted to a narrow zone. The aforesaid patterns of decay in fossil wood show similarities with that of white rot decay commonly produced by higher fungi, specifically basidiomycetes and ascomycetes. The host fossil wood harbors abundant ramifying and septate fungal hyphae with knob like swellings similar to pseudoclamps in basidiomycetes, and three-celled conidia-like reproductive structures. This record expands our current knowledge of wood decaying fungi-host plant interaction in the Neogene tropical forests of Peninsular India. [Abstract copyright: Copyright © 2020 British Mycological Society. Published by Elsevier Ltd. All rights reserved.