Characterization, Antioxidant, and Antimicrobial Properties of Mulberry Lattices.

In order to find the most advantageous bioactive compounds from mulberry latex for drug development in the near future, this study was conducted to characterize and evaluate antioxidant and antimicrobial properties from four different mulberry lattices (BR-2, S-1, AR-14, and S-146). The characterization of the lattices was performed by scanning electron microscopy with energy-dispersive X-ray spectroscopy, gas chromatography coupled to mass spectroscopy, and Fourier transform infrared spectroscopy. Further, screenings of the antioxidant and antimicrobial potential of selected lattices were performed in vitro using 2,2-diphenyl-1-picrylhydrazyl assay and agar well diffusion methods, respectively. Interestingly, the outcome of the current study revealed that tested mulberry lattices contain a considerable amount of bioactive phytoconstituents, particularly antimicrobial and antioxidant compounds, as revealed by chromatographic analysis. BR-2 latex was found to have significant antioxidant activity (75%) followed by S-146 (64.6%) and AR-14 (52.9%). The maximum antimicrobial activity was found in BR-2 latex compared to other tested latex varieties. The results of this investigation showed that mulberry latex from the BR-2 type may successfully control both bacterial and fungal infections, with the added benefit of having enhanced antioxidant capabilities.

Comparison of crestal bone loss and papilla fill after conventional and immediate implant placement: A 12 month clinical and radiographic prospective study.

Background: The problem of missing teeth persists in all age groups. The main objective of implants in dentistry is to provide a restoration that reconstructs the shape and restores esthetics and functions of edentulous areas. The objectives of this study are to compare the crestal bone level changes and papillary fill after placement of implants in fresh extraction socket, i.e. immediate implant placement, and healed extraction socket, i.e. delayed or conventional implant placement, and to assess other clinical parameters such as modified plaque index (mPI), modified gingival index (mGI) and gingival biotype in between the groups and within the groups. Methods: 18 patients were recruited in the study out of which 9 patients received implants as per immediate implant placement protocol (group 1) and 9 patients received implants as per conventional implant placement protocol (group 2). All patients were evaluated for gingival biotype, mPI and mGI and papillary fill was assessed as per Jemt's papilla score as clinical parameters. Implant site was assessed for radiographic bone loss using Image J software. Statistical analysis was performed using independent t test, paired t test and chi square test. Results: At the end of 1 year, results showed that crestal bone loss was seen more in the immediate group than the conventional group. Conventional implants showed better papillary fill than implants placed in fresh extraction sockets. Plaque scores were assessed as per modified plaque index, which showed better results in the conventional group. Modified gingival index was used to assess gingival status which showed better results in the immediate group one year later. Conclusions: Findings from the study suggest that crestal bone loss was found to be increased in the immediate group than the conventional group and papillary fill was better in the conventional group than the immediate group.Registration: CTRI ( CTRI/2019/09/021340).

Transcriptional pausing factor M1BP regulates cellular homeostasis by suppressing autophagy and apoptosis in Drosophila eye.

During organogenesis cellular homeostasis plays a crucial role in patterning and growth. The role of promoter proximal pausing of RNA polymerase II, which regulates transcription of several developmental genes by GAGA factor or Motif 1 Binding Protein (M1BP), has not been fully understood in cellular homeostasis. Earlier, we reported that M1BP, a functional homolog of ZKSCAN3, regulates wingless and caspase-dependent cell death (apoptosis) in the Drosophila eye. Further, blocking apoptosis does not fully rescue the M1BPRNAi phenotype of reduced eye. Therefore, we looked for other possible mechanism(s). In a forward genetic screen, members of the Jun-amino-terminal-(NH2)-Kinase (JNK) pathway were identified. Downregulation of M1BP ectopically induces JNK, a pro-death pathway known to activate both apoptosis and caspase-independent (autophagy) cell death. Activation of JNK pathway components can enhance M1BPRNAi phenotype and vice-versa. Downregulation of M1BP ectopically induced JNK signaling, which leads to apoptosis and autophagy. Apoptosis and autophagy are regulated independently by their genetic circuitry. Here, we found that blocking either apoptosis or autophagy alone rescues the reduced eye phenotype of M1BP downregulation; whereas, blocking both apoptosis and autophagy together significantly rescues the M1BP reduced eye phenotype to near wild-type in nearly 85% progeny. This data suggests that the cellular homeostasis response demonstrated by two independent cell death mechanisms, apoptosis and autophagy, can be regulated by a common transcriptional pausing mechanism orchestrated by M1BP. Since these fundamental processes are conserved in higher organisms, this novel functional link between M1BP and regulation of both apoptosis and autophagy can be extrapolated to humans.

Unraveling acute hemorrhagic edema of infancy in the COVID-19 era: Insights from a tribal area in Jharkhand.

Acute hemorrhagic edema of infancy (AHEI) is a benign and rare presentation of leukocytoclastic vasculitis that usually affects children between 4 months and 24 months of age. It is characterized by purpuric and ecchymotic lesions that mainly involve the distal extremities, the face, and the ears. It usually follows some viral or bacterial infection. Here, we report a case of a 25-month-old male child who presented with mild grade fever and upper respiratory tract infection symptoms. Subsequently, he developed progressive purpuric and ecchymotic lesions over his body, mainly on his lower limbs and face. Laboratory tests were done, showing elevated C-reactive protein and erythrocyte sedimentation rate with rest of normal results. In view of patients having respiratory symptoms, reverse-transcriptase polymerase chain reaction of a nasopharyngeal swab for coronavirus disease 2019 (COVID-19) was done, which came out to be positive. The baby received supportive care only. He gradually improved and was discharged successfully. AHEI may be a possible after effect of COVID-19 infection.

Determination of safe limit for arsenic contaminated irrigation water using solubility free ion activity model (FIAM) and Tobit Regression Model.

Irrigation water contaminated with arsenic acts as a potent source of contamination to humans through water-soil-crop-food transfer so quantification of safe limit for irrigation water is also critical. A pot experiment was conducted to determine the safe limit for As contaminated irrigation water with two soil types (alluvial and red) using ten levels of contaminated irrigation water (0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.50, 1.75, 2.0, 2.25 mg L-1), applied 5 times in rice (Variety: Sushak Samrat),used as a test crop. The results reveal that the different fractions of arsenic in terms of its profusion followed the order F4 > F2 > F5 > F3 > F1 and F4 > F3 > F2 > F5 > F1 across all the doses of As for alluvial soil and red soil respectively. The safe limit of irrigation water in terms of risk assessment expressed as Hazard Quotient (HQ) was at 0.75 mg L-1 and the solubility FIAM can effectively predict the As content in rice grain in both the soils. The Tobit Regression Model in alluvial soil quantified the safe limit for As in irrigation water from 1.20 to 0.10 mg L-1 for available soil As 0.25-3.0 mg kg-1 and in red soil, the range was from 0.10 to 0.40 mg L-1 for soil As 1.0 to 0.25 mg kg-1 provided that the As content in rice grain is < 0.4 mg kg-1. This proved to be an effective protocol for estimation of safe limits after proper validation and calibration.

Combating silver nanoparticle-mediated toxicity in Drosophila melanogaster with curcumin.

Nanoscale materials display unique physical and chemical properties that enable their assimilation into a variety of industrial and consumer products. Amongst the widely used nanomaterials, silver nanoparticles (AgNPs) have gained tremendous recognition for various applications, owing to their extraordinary plasmonic and bactericidal properties. Despite of the extensive usage of AgNPs in various sectors, its impact on human health remains ambiguous. Several studies have established that higher doses of AgNPs are detrimental to organismal health. In order to attain the best from these versatile nanoparticles, a recent advent of green nanotechnology, that is, employment of metal nanoparticles synthesized using plant extracts, has emerged. Here, using Drosophila as a model system, we tested if adding curcumin, a biologically active polyphenolic compound present in turmeric, having multitudes of therapeutic properties, could mitigate AgNP-mediated biotoxicity. We found that co-administration of AgNPs with curcumin in the fly food could alleviate several harmful effects evoked by AgNPs ingestion in Drosophila model. Addition of curcumin superseded reduction in feeding, pupation, eclosion, pigmentation, and fertility caused by AgNPs ingestion. Interestingly, impairment in ovary development observed in flies reared on AgNPs-supplemented food was also partially restored by co-administration of AgNPs with curcumin. Furthermore, substantial alleviation of reactive oxygen species level and cell death was observed in larval tissues upon co-supplementation of AgNPs with curcumin. We therefore propose that curcumin, when administered with AgNPs, can abrogate the toxic manifestations of AgNPs ingestion and hence can be incorporated in various consumer products encompassing it.

Discriminatory alteration of carbohydrate homeostasis by gold nanoparticles ingestion in Drosophila.

With the extensive usage of gold nanoparticles (AuNPs) in various industrial sectors and biomedical applications, evaluation of their possible effects on human health becomes imperative. Therefore, the present study was aimed toward assessing the dose-dependent impact of AuNPs ingestion on metabolic homeostasis using Drosophila melanogaster as a model system. We found that larval ingestion of higher dose of AuNPs significantly reduced body weight. Further analysis of the crucial energy reservoir showed selective alteration in carbohydrate levels without any change in the lipid and protein levels. Transcriptional downregulation of glycogen synthase further supported impaired glycogen metabolism in flies supplemented with higher dose of AuNPs. Additionally, ingestion of higher dose of AuNPs in larvae results in significantly increased levels of reactive oxygen species (ROS) in the peripheral tissues, suggestive of stress condition. Our findings clearly imply that supplementing higher doses of AuNPs at an early developmental stage can potentially cause weight loss, impair glycogen metabolism, and elevate ROS production. Therefore, determination of a biologically effective dose is critical for the safety of mankind and vulnerable populations at the workplace.

Motif 1 Binding Protein suppresses wingless to promote eye fate in Drosophila.

The phenomenon of RNA polymerase II (Pol II) pausing at transcription start site (TSS) is one of the key rate-limiting steps in regulating genome-wide gene expression. In Drosophila embryo, Pol II pausing is known to regulate the developmental control genes expression, however, the functional implication of Pol II pausing during later developmental time windows remains largely unknown. A highly conserved zinc finger transcription factor, Motif 1 Binding Protein (M1BP), is known to orchestrate promoter-proximal pausing. We found a new role of M1BP in regulating Drosophila eye development. Downregulation of M1BP function suppresses eye fate resulting in a reduced eye or a "no-eye" phenotype. The eye suppression function of M1BP has no domain constraint in the developing eye. Downregulation of M1BP results in more than two-fold induction of wingless (wg) gene expression along with robust induction of Homothorax (Hth), a negative regulator of eye fate. The loss-of-eye phenotype of M1BP downregulation is dependent on Wg upregulation as downregulation of both M1BP and wg, by using wgRNAi, shows a significant rescue of a reduced eye or a "no-eye" phenotype, which is accompanied by normalizing of wg and hth expression levels in the eye imaginal disc. Ectopic induction of Wg is known to trigger developmental cell death. We found that upregulation of wg as a result of downregulation of M1BP also induces apoptotic cell death, which can be significantly restored by blocking caspase-mediated cell death. Our data strongly imply that transcriptional regulation of wg by Pol II pausing factor M1BP may be one of the important regulatory mechanism(s) during Drosophila eye development.

Influence of high hydrostatic pressure on solid supported DPPC bilayers with hyaluronan in the presence of Ca2+ ions.

The molecular mechanisms responsible for outstanding lubrication of natural systems, like articular joints, have been the focus of scientific research for several decades. One essential aspect is the lubrication under pressure, where it is important to understand how the lubricating entities adapt under dynamic working conditions in order to fulfill their function. We made a structural investigation of a model system consisting of two of the molecules present at the cartilage interface, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and hyaluronan, at high hydrostatic pressure. Phospholipid layers are found at the cartilage surfaces and are able to considerably reduce friction. Their behavior under load and varied solution conditions is important as pressures of 180 bar are encountered during daily life activities. We focus on how divalent ions, like Ca2+, affect the interaction between DPPC and hyaluronan, as other investigations have indicated that calcium ions influence their interaction. It could be shown that already low amounts of Ca2+ strongly influence the interaction of hyaluronan with DPPC. Our results suggest that the calcium ions increase the amount of adsorbed hyaluronan indicating an increased electrostatic interaction. Most importantly, we observe a modification of the DPPC phase diagram as hyaluronan absorbs to the bilayer which results in an Lα-like structure at low temperatures and a decoupling of the leaflets forming an asymmetric bilayer structure.

Sedentary behavior and altered metabolic activity by AgNPs ingestion in Drosophila melanogaster.

Among several nanoparticles, silver nanoparticles (AgNPs) are extensively used in a wide variety of consumer products due to its unique antimicrobial property. However, dosage effect of AgNPs on behavior and metabolic activity in an in vivo condition is not well studied. Therefore, to elucidate the impact of AgNPs on behavior and metabolism, systematic and detailed dosages study of AgNPs was performed by rearing Drosophila melanogaster on food without and with AgNPs. We found that dietary intake of AgNPs at early larval stage leads to behavioral abnormalities such as poor crawling and climbing ability of larvae and adults respectively. Interestingly, intake of higher dosage of AgNPs at larval stage significantly altered metabolic activity that includes lipid, carbohydrate and protein levels in adult flies. Further, detailed analysis revealed that AgNPs causes remarkable reduction in the number of lipid droplets (LDs) which are lipid storage organelles in Drosophila. We also observed an increased production of reactive oxygen species (ROS) in AgNPs ingested larval tissues. These results strongly imply that higher dosage of AgNPs ingestion from early larval stage of Drosophila is inimical and thereby draws concern towards the usage of AgNPs in consumer goods.

Dose-dependent effect of silver nanoparticles (AgNPs) on fertility and survival of Drosophila: An in-vivo study.

Silver nanoparticles (AgNPs) containing consumer products have been proliferating in the market due to its unique antimicrobial property, however, lack of in-depth knowledge about their potential effect on human health in a longer run is of great concern. Therefore, we investigated dose-dependent in vivo effect of AgNPs using Drosophila as a model system. Drosophila, a genetically tractable organism with distinct developmental stages, short life cycle and significant homology with human serves as an ideal organism to study nanomaterial-mediated toxicity. Our studies suggest that ingestion of AgNPs in Drosophila during adult stage for short and long duration significantly affects egg laying capability along with impaired growth of ovary. Additionally, dietary intake of AgNPs from larval stage has more deleterious effects that result in reduced survival, longevity, ovary size and egg laying capability at a further lower dosage. Interestingly, the trans-generational effect of AgNPs was also observed without feeding progeny with AgNPs, thereby suggesting its impact from previous generation. Our results strongly imply that higher doses of AgNPs and its administration early during development is detrimental to the reproductive health and survival of Drosophila that follows in generations to come without feeding them to AgNPs.

Molecular synergy in biolubrication: The role of cartilage oligomeric matrix protein (COMP) in surface-structuring of lubricin.

HYPOTHESIS: Synovial surfaces are lubricated by biomolecular aggregates that act in synergy, and lubricin is one key biolubricant. Its molecular structure allows extensive hydration and this is conducive to its lubrication performance. However, in order to fullfil its lubrication function it needs to be anchored and oriented on the surface in a proper way. We suggest that cartilage oligomeric matrix protein (COMP) is one of the biomolecules that promotes anchoring of lubricin in a fashion that facilitates lubrication. EXPERIMENTS: Weakly hydrophobic poly(methyl methacrylate) (PMMA) surfaces were coated by COMP and lubricin, individually and in combinations. Adsorption was investigated using a quartz crystal microbalance, and friction between the biopolymer-coated surfaces was determined by employing the atomic force microscope-colloidal probe technique. FINDINGS: It was found that COMP facilitated firm directed attachment of lubricin in a manner that resulted in low friction forces, significantly lower than what was achieved when lubricin was directly adsorbed to PMMA. Evidently, COMP provides means for lubricin to attach strongly and in a favourable conformation for efficient lubrication of this surface. We suggest that our findings can be extrapolated to cartilage surfaces, where co-localization of COMP and lubricin has been demonstrated.

Lubrication synergy: Mixture of hyaluronan and dipalmitoylphosphatidylcholine (DPPC) vesicles.

Phospholipids and hyaluronan have been implied to fulfil important roles in synovial joint lubrication. Since both components are present in synovial fluid, self-assembly structures formed by them should also be present. We demonstrate by small angle X-ray scattering that hyaluronan associates with the outer shell of dipalmitoylphophatidylcholine (DPPC) vesicles in bulk solution. Further, we follow adsorption to silica from mixed hyaluronan/DPPC vesicle solution by Quartz Crystal Microbalance with Dissipation measurements. Atomic Force Microscope imaging visualises the adsorbed layer structure consisting of non-homogeneous phospholipid bilayer with hyaluronan/DPPC aggregates on top. The presence of these aggregates generates a long-range repulsive surface force as two such surfaces are brought together. However, the aggregates are easily deformed, partly rearranged into multilayer structures and partly removed from between the surfaces under high loads. These layers offer very low friction coefficient (<0.01), high load bearing capacity (≈23MPa), and self-healing ability. Surface bound DPPC/hyaluronan aggregates provide a means for accumulation of lubricating DPPC molecules on sliding surfaces.

The influence of hyaluronan on the structure of a DPPC-bilayer under high pressures.

The superior lubrication properties of synovial joints have inspired many studies aiming at uncovering the molecular mechanisms which give rise to low friction and wear. However, the mechanisms are not fully understood yet, and, in particular, it has not been elucidated how the biolubricants present at the interface of cartilage respond to high pressures, which arise during high loads of joints. In this study we utilize a simple model system composed of two biomolecules that have been implied as being important for joint lubrication. It consists of a solid supported dipalmitoylphosphatidylcholin (DPPC) bilayer, which was formed via vesicles fusion on a flat Si wafer, and the anionic polysaccharide hyaluronan (HA). We first characterized the structure of the HA layer that adsorbed to the DPPC bilayers at ambient pressure and different temperatures using X-ray reflectivity (XRR) measurements. Next, XRR was utilized to evaluate the response of the system to high hydrostatic pressures, up to 2kbar (200MPa), at three different temperatures. By means of fluorescence microscopy images the distribution of DPPC and HA on the surface was visualized. Our data suggest that HA adsorbs to the headgroup region that is oriented towards the water side of the supported bilayer. Phase transitions of the bilayer in response to temperature and pressure changes were also observed in presence and absence of HA. Our results reveal a higher stability against high hydrostatic pressures for DPPC/HA composite layers compared to that of the DPPC bilayer in absence of HA.

Structure of DPPC-hyaluronan interfacial layers - effects of molecular weight and ion composition.

Hyaluronan and phospholipids play an important role in lubrication in articular joints and provide in combination with glycoproteins exceptionally low friction coefficients. We have investigated the structural organization of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir layers at the solution-air interface at different length scales with respect to the adsorption of hyaluronan (HA). This allows us to assemble a comprehensive picture of the adsorption and the resulting structures, and how they are affected by the molecular weight of HA and the presence of calcium ions. Brewster angle microscopy and grazing incident diffraction were used to determine the lateral structure at the micro- and macro scale. The data reveals an influence of HA on both the macro and micro structure of the DPPC Langmuir layer, and that the strength of this effect increases with decreasing molecular weight of HA and in presence of calcium ions. Furthermore, from X-ray reflectivity measurements we conclude that HA adsorbs to the hydrophilic part of DPPC, but data also suggest that two types of interfacial structures are formed at the interface. We argue that hydrophobic forces and electrostatic interactions play important rules for the association between DPPC and HA. Surface pressure area isotherms were used to determine the influence of HA on the phase behavior of DPPC while electrophoretic mobility measurements were used to gain insight into the binding of calcium ions to DPPC vesicles and hyaluronan.

The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: structure and lubrication performance.

Phospholipids fulfill an important role in joint lubrication. They, together with hyaluronan and glycoproteins, are the biolubricants that sustain low friction between cartilage surfaces bathed in synovial fluid. In this work we have investigated how the friction force and load bearing capacity of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers on silica surfaces are affected by temperature, covering the temperature range 25-52°C. Friction forces have been determined utilizing the AFM colloidal probe technique, which showed that DPPC bilayers are able to provide low friction forces over the whole temperature interval. However, the load bearing capacity is improved at higher temperatures. We interpret this finding as being a consequence of lower rigidity and higher self-healing capacity of the DPPC bilayer in the liquid disordered state compared to the gel state. The corresponding structure of solid supported DPPC bilayers at the silica-liquid interface has been followed using X-ray reflectivity measurements, which suggests that the DPPC bilayer is in the gel phase at 25°C and 39°C and in the liquid disordered state at 55°C. Well-defined bilayer structures were observed for both phases. The deposited DPPC bilayers were also imaged using AFM PeakForce Tapping mode, and these measurements indicated a less homogeneous layer at temperatures below 37°C.