Adsorption-desorption dynamics of synthetic and naturally weathered microfibers with toxic heavy metals and their ecological risk in an estuarine ecosystem.

Microfibers (MFs) in aquatic and marine ecosystems adsorb toxic heavy metals and then transfer the heavy metals enriched MFs to living organisms. In this research paper, the adsorption-desorption dynamics of heavy metals onto MFs was studied by using theoretical models and experimental investigations. The adsorption of metals onto MFs was well correlated for the Freundlich model and the adsorption kinetics follows pseudo-second order rate equation. The adsorption capacity of naturally weathered MFs was 30.8 mg g-1 which is about 35% higher than the synthetic fiber of similar range of size of MFs. The leaching of heavy metals from MFs was found that 90-95% of adsorbed metals were leached within 24 h. The leaching of Ti(II) and Al(III) were slower than the other metal ions. The salinity has shown decrease in adsorption capacity of MFs for heavy metals. Based on the Nemerov pollution index (PN), the naturally weathered MFs enriched with heavy metals in sediments became heavily polluted with PN values between 2.98 and 3.49. The risk index value of 396 represents that the bottom dwellers and other marine organisms in the Narmada estuary high risk from MFs and MFs enriched with metals. This study indicates that MFs play dominant role in fate and distribution of heavy metals in the estuarine ecosystems.

Graphene/fluorescein dye-based sensor for detecting As(III) in drinking water.

A complex of reduced graphene oxide (rGO) and fluorescein (FL) dye nanoparticles of size between 50 and 100 nm has been prepared and its sensing performance for detection of As(III) in drinking water has been reported. When As(III) binds to the rGO-FL nanoparticles the relative quenching of fluorescence was increased with increase in As(III) concentration thus provide two linear calibration ranges (0-4.0 mmol L-1 and 4.0-10 mmol L-1). The fluorescence quenching mechanism was investigated by using time-resolved fluorescence spectroscopy and molecular modeling. The detection limit of this sensor has been determined as equal to 0.96 µg L-1 which is about 10 times lower than the WHO stipulated standard for As(III) in drinking water (10 µg L-1). The analytical performance and potential application of the nanosensor was compared to commercial field kits used in arsenic monitoring. The sensor proposed in this study is fast, sensitive and accurate for detection of As(III) in drinking water and environmental samples.

Highly selective electrochemical nanofilm sensor for detection of carcinogenic PAHs in environmental samples.

A highly sensitive sensor based on molecularly imprinted polymer film was devised for determination of polycyclic aromatic hydrocarbon (PAHs) in aquatic solutions. In this paper we report, electro-polymerisation of 4-vinyl pyridine (4VP) and target, pyrene, using cyclic voltammeter in electrolyte medium, forming the pyrene imprinted polymer. After polymerisation, the pyrene was removed from imprinted polymer using methanol to produce sensory nanofilm characterised by infrared spectrometer, optical and atomic force microscopy. The mechanism of nanofilm sensing was established using atomic models and electrochemical response by differential pulse voltammeter with the redox system of ([Fe(CN)6]3-/[Fe(CN)6]4-). The π-π interaction between pyrene and 4VP was primary cause for pyrene recognition in aqueous solutions and the model binding score for this interaction was -5.10 kcal mol-1. The electrochemical sensor determined pyrene in the concentration range of 1 × 10-4 - 1 ng L-1, resulting best linear regression (r2 > 0.9) and detection limit of 0.001 ng L-1. The recovery percentage of pyrene from the nanofilm was 83-110% in water samples and the imprinting factor value was 2.67. Therefore, the novel imprinted polymer nanofilm sensor showed highest sensitivity for target pyrene in aqueous samples compared to reported sensors.

Assessment of cancer risk of microplastics enriched with polycyclic aromatic hydrocarbons.

Abundance of microplastics in aquatic and marine ecosystems is contaminating the seafood and it is leading to transfer of toxic pollutants to human beings. In this article, we report the hazardous nature and cancer risk of microplastics which originate from e-waste. Capture of carcinogenic polycyclic aromatic hydrocarbons (PAHs) onto microplastics by adsorption phenomena and an assessment of probable cancer risk of ingested PAHs enriched microplastics by human beings have been investigated. The adsorption equilibrium was well fit for the Freundlich isotherm model. The adsorption capacity of carcinogenic PAHs on microplastics was ranged from 46 to 236 µg g-1 and the maximum binding was achieved within 45 min in water. The leachate derived from microplastics of e-waste were highly hazardous in nature, for example, the sum of PAHs was 3.17 mg L-1 which is about 1000 times higher than the standard for benzo[a]pyrene, a congener of PAHs. The calculated cancer risk in terms of lifetime of microplastic ingestion would be 1.13 × 10-5 for children and 1.28 × 10-5 for adults and these values are higher than the recommended value of 106. The abundance of microplastics could transfer hazardous pollutants to seafood (e.g., fishes and prawns) leading to cancer risk in human beings.

Molecularly imprinted microparticles (microMIPs) embedded with reduced graphene oxide for capture and destruction of E.coli in drinking water.

In this article for the first time, we have reported, a facile way for the creation of E.coli impressions in the polymer for selective capture and to destroy E. coli in drinking water. This microporous imprinted polymer has shown the existence of micrometer size rod shape cavities with the population of 2.45 × 102 ± 60 imprints per cm2. Adsorption capacity of the polymer for E.coli was 103 CFU mg-1. This microporous imprinted polymer captured 99% of the bacteria within 30 min at initial concentration of 109 CFU mL-1. The non-imprinted polymer prepared without the bacteria imprinting reported only 40% of the bacteria removal even after 60 min. The reduced graphene oxide was embedded in the microporous imprinted polymer and it reported minimum inhibitory concentration at 7.4 mg L-1. Within 10 min, reduced graphene oxide completely kills the E.coli while microporous imprinted polymer was embedded with the reduced graphene oxide takes about 13 min to disinfect the water. The reduced graphene oxide nanoparticles were near the imprinted cavity to generate localized temperature between 180 and 210 °C to kill the bacterial cells trapped inside the imprinted cavities of the polymer. The thermal atomic force microscope with the specialized heated probe tips were used to determine the localized temperature in the polymers. The localized thermal energy would be responsible for the production of superoxides, which were as similar to photolysis reactions, and would be further improving antibacterial activity. The combination of selective capture and destruction of pathogens in a single molecular construct improves disinfection of drinking water.

Studies on synthesis of novel pyrido[2,3-d]pyrimidine derivatives, evaluation of their antimicrobial activity and molecular docking.

A series of novel pyrido[2,3-d]pyrimidine derivatives 6 were prepared starting from 2-amino-3-cyano-4-trifluoromethyl-6-phenyl pyridine 3 via Grignard's reaction, cyclization followed by coupling with aliphatic and cyclic amines. All the compounds 6 were screened for antibacterial, minimum bactericidal concentration (MBC), biofilm inhibition activity as well as antifungal and minimum fungicidal concentration (MFC) activities. Among the screened compounds, the compounds 6e, 6f, and 6m which showed exhibiting promising activity have been identified. The results reveal that the compound pyrido[2,3-d]pyrimidine derivative 6e altered the sterol profile which may exert its antifungal activity through inhibition of ergosterol biosynthesis and could be an ideal candidate for antifungal therapy. The molecular docking results also validated the antifungal results.

Use of locking plate in combination with dynamic compression plate for repair of tibial fracture in a young horse.

Grade 1 open spiral fracture of left tibia in a 1.5 year-old horse was treated using a combination of 4.5 mm locking compression plate (LCP) and a dynamic compression plate applied in a neutralization manner. The open wound was managed postoperatively by regular dressing and lavage. Radiograph at 24 days post-treatment revealed callus formation and at two months complete bridging callus was observed. At the end of six months complete healing of the fracture with functional recovery of the limb was observed.

Evaluation of persistence and distribution of intra-dermally administered PKH26 labelled goat bone marrow derived mesenchymal stem cells in cutaneous wound healing model.

The current study was designed to study the persistence and distribution of caprine bone marrow derived mesenchymal stem cells (cBM-MSCs) when administered intra-dermally in experimentally induced cutaneous wounds in rabbits. MSC's from goat bone marrow were isolated and their differentiation potential towards adipogenic and osteogenic lineages were assayed in vitro. The isolated cells were phenotypically analysed using flow cytometry for the expression of MSC specific matrix receptors (CD73, CD105 and Stro-1) and absence of hematopoietic lineage markers. Further, these in vitro expanded MSCs were stained with PKH26 lipophilic cell membrane red fluorescent dye and prepared for transplantation into cutaneous wounds created on rabbits. Five, 2 cm linear full thickness skin incisions were created on either side of dorsal midline of New Zealand white rabbits (n = 4). Four wounds in each animal were implanted intra-dermally with PKH26 labelled cBM-MSCs suspended in 500 µl of Phosphate Buffer Saline (PBS). Fifth wound was injected with PBS alone and treated as negative control. The skin samples were collected from respective wounds on 3, 7, 10 and 14 days after the wound creation, and cryosections of 6 µM were made from it. Fluorescent microscopy of these cryosections showed that the PKH26 labelled transplanted cells and their daughter cells demonstrated a diffuse pattern of distribution initially and were later concentrated towards the wound edges and finally appeared to be engrafted with the newly developed skin tissues. The labelled cells were found retained in the wound bed throughout the period of 14 days of experimental study with a gradual decline in their intensity of red fluorescence probably due to the dye dilution as a result of multiple cell division. The retention of transplanted MSCs within the wound bed even after the complete wound healing suggests that in addition to their paracrine actions as already been reported, they may have direct involvement in various stages of intricate wound healing process which needs to be explored further.

Comparative study on characterization and wound healing potential of goat (Capra hircus) mesenchymal stem cells derived from fetal origin amniotic fluid and adult bone marrow.

Caprine amniotic fluid (cAF) and bone marrow cells (cBM) were isolated, expanded and phenotypically characterized by mesenchymal stem cells (MSCs) specific cell surface markers. Both cell types were compared for multilineage differentiation potential by flow cytometry using specific antibodies against lineage specific markers. Furthermore, in vitro expanded cAF-MSCs showed higher expression of trophic factors viz. VEGF and TGF-ß1 as compared to cBM-MSCs. Full-skin thickness excisional wounds created on either side of the dorsal midline (thoracolumbar) of New Zealand White rabbits were randomly assigned to subcutaneous injection of either fetal origin cAF-MSCs (n=4) or adult cBM-MSCs (n=4) or sterile PBS (control, n=4). The rate of wound closure was found faster (p<0.05) in cAF-MSCs treated wounds as compared with cBM-MSCs and PBS treated wounds especially on 21st day post-skin excision. Histomorphological examination of the healing tissue showed that wound healing was improved (p<0.05) by greater epithelialization, neovascularization and collagen development in cAF-MSCs as compared to cBM-MSCs and PBS treated wounds.

Molecular cloning and characterization of arginine kinase gene of Toxocara canis.

Toxocara canis is an important gastrointestinal nematode of dogs and also a causative agent of visceral larva migrans in humans. Arginine kinase (AK) gene is one of the important biomolecule of phosphagen kinase of T. canis which is emerging as an exciting novel diagnostic target in toxocarosis. The present study was carried out to clone and characterize AK gene of T. canis for future utilization as a diagnostic molecule. Total RNA was extracted from intact adult worms and reverse transcription was done with oligo dT primers to obtain complementary DNA (cDNA). Polymerase chain reaction (PCR) was carried out using cDNA as template with specific primers which amplified a product of 1,202 bp. The amplicon was cloned into pDrive cloning vector and clone was confirmed by colony PCR and restriction endonuclease analysis. Sequence analysis of the gene showed 99.8 and 77.9 % homology with the published AK gene of T. canis (EF015466.1) and Ascaris suum respectively. Structural analysis shown that the mature AK protein consist of 400 amino acids with a molecular wt of 45360.73 Da. Further expression studies are required for producing the recombinant protein for its evaluation in the diagnosis of T. canis infection in humans as well as in adult dogs.

In vitro biomechanical testing of different configurations of acrylic external skeletal fixator constructs.

OBJECTIVE: To evaluate the in vitro biomechanical properties of four different configurations of acrylic external skeletal fixator constructs. MATERIALS AND METHODS: Simulated bone constructs were prepared using two segments of 20 mm ultra-high-density polyethylene rods with a gap of 5 mm. The full pins (1.5 mm) were passed through the proximal and distal segments of ultra-high-density polyethylene rods, in the same plane, parallel to each other in configuration U, and were crossed in the M1, M2 and C configurations at a 90° angle to each other. Configuration U was a single bilateral uniplanar construct, M1 was a double orthogonal bilateral construct, M2 was a double orthogonal bilateral construct with proximal and distal connecting articulations, and C was a double orthogonal bilateral construct with proximal and distal circumferential articulations. Temporary scaffolds of different external skeletal fixator configurations were constructed using commercially available polyvinyl chloride pipes (20 mm) connected and secured to the fixation pins at a fixed distance from the rods. Acrylic powder (polymer) mixed with liquid (monomer) was poured into the pipes and allowed to solidify to form the side bars and rings. The external skeletal fixator constructs were then subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters, namely stress, strain, modulus of elasticity, stiffness and bending moment of fixator constructs, were determined from load-displacement curves. RESULTS: Configuration U was the weakest and configuration C was the strongest under all the testing modes. Under compression, the M1, M2 and C configurations were similar. Under bending, a significant difference was observed among the uniplanar, multiplanar and circular configurations with no difference between M1 and M2. However, under torsion, all the external skeletal fixator configurations differed significantly. CLINICAL SIGNIFICANCE: The freeform external skeletal fixator using acrylic as a replacement for a metallic bar may be useful to treat bone fractures and luxations in small animals, as it is mechanically strong, lightweight, economical, and pins can be passed from any direction depending upon the clinical situation.

Nasal Oestrosis in a Jamunapari goat.

Oestrus ovis is a well-known parasite of the nasal cavities and adjoining sinuses in sheep and goats. A 3-year-old female Jamunapari goat was presented with a history of anorexia, weight loss, in-coordinated movements, nasal discharge since 10 days and two nasal bots expelled during sneezing 3 days back. Upon clinical examination the animal was dull, dysphonic, unsteady gait and having blocked nostrils with thick mucoid discharge along with an increased respiratory rate. Parasitiological examination revealed it as an O. ovis (nasal bots). The occurrence of nasal bots in a goat and its successful therapeutic management and public health significance have been reported and discussed in the present communication.

Coenurus gaigeri cyst in the thigh of a goat and its successful management.

A 11 month old female goat was presented to Polyclinic, IVRI with the history of swelling in the left hind leg on the inner aspect of thigh and inguinal region. Physical and radiological examination revealed a large fluctuating fluid filled bladder with distinct dimension. The cyst was successfully removed along with its membrane and parasitological examination revealed it as a Coenurus gaigeri, the intermediate stage of T. multiceps gaigeri. The animal recovered completely by 10th postoperative day without any complications. This is being described in detail as under.

Molecular characterization and xenogenic application of Wharton's jelly derived caprine mesenchymal stem cells.

Aim of the present study was in vitro expansion and characterization of caprine wharton's jelly derived mesenchymal stem cells (cWJ-MSCs) to investigate their tissue healing potential in xenogenic animal model. Plastic adherent fibroblastoid cell populations with distinctive homogeneous morphology were isolated from caprine Wharton's jelly explants. These Wharton's jelly derived cells were found positive for the surface markers CD-73, STRO-1 and CD-105, whereas they were negative for hematopoetic stem cell marker CD-34. In vitro cultured cWJ-MSCs also showed differentiation properties into osteogenic, adipogenic and chondrogenic lineages as demonstrated by von Kossa, Oil Red-O and Alcian blue staining respectively, which was further confirmed and quantified by flow cytometric analysis. Furthermore, these well characterized cWJ-MSCs were evaluated for the wound-healing potential in full-thickness skin wounds in rabbit model for 28 days. Caprine WJ- MSCs treated skin wounds showed significantly (P < 0.05) higher percentage of wound contraction especially at the 21(st) day post transplantation when compared to PBS treated control group animals. Further, we observed better healing potential of cWJ-MSCs in terms of histo-morphological evaluation, epithelialisation and collagenization with matured vascularization stage by day 28 as compared to control. In conclusion, cWJ- MSCs provide an alternative inexhaustible source of mesenchymal stem cells and also unravel new perspectives pertaining to the therapeutic use of these cells in different species.

Levalbuterol versus racemic albuterol in the treatment of acute exacerbation of asthma in children.

OBJECTIVE: To compare levalbuterol and racemic albuterol for the treatment of acute exacerbation of asthma in pediatric population. DESIGN: Prospective, double-blind, randomized research trial in a pediatric emergency department of an urban tertiary care hospital. PARTICIPANTS: Children 5 to 21 years with a history of asthma presenting to the emergency department in acute exacerbation. INTERVENTIONS: As per a computer-generated randomization sequence, patients received either 1.25 mg of levalbuterol or albuterol 2.5 mg via nebulization along with ipratropium hydrochloride. Patients received 3 back-to-back treatments as needed every 20 minutes, maximum of 3; 2 mg/kg of oral prednisone was administered to the patients after the second treatment. Baseline respiratory parameters such as oxygen saturations, respiratory rates, and peak flow rates were measured and repeated after every treatment.The decision for further treatments and or hospitalization was made by the treating emergency department physician as per his/her clinical judgement of the respiratory parameters at the end of 3 treatments. RESULTS: Seventy patients completed the study. Most of the patients were in moderate severity of asthma exacerbation. All patients in both groups showed improvement in oxygen saturations, respiratory rates, and peak flow rates. However, no statistically significant difference was observed in the 2 groups regarding the respiratory parameters (P > 0.05). CONCLUSION: Levalbuterol is not more efficacious than racemic albuterol in improving respiratory parameters in children presenting with acute exacerbation of asthma.

Emergency department presentations of a rare tumor--extraosseous cervical paraspinal Ewing's sarcoma.

We report the case of a 9-year-old boy who presented to our community-based Pediatric Emergency Department with complaints of neck pain, stiffness and upper extremity weakness. The symptoms were later identified to be due to cervical extraosseous paraspinal Ewing's sarcoma. The patient had a fatally aggressive clinical course. Cervical extraosseous Ewing's sarcoma is rarely reported in pediatrics. Ewing's sarcoma should be considered in the differential diagnosis of children presenting with complaints of unremitting or recurring non-specific back or neck pain or neurological deficits. Appropriate diagnostic evaluation and treatment should be actively pursued.