Evaluation of risk due to chronic low dose ionizing radiation exposure on the birth prevalence of congenital heart diseases (CHD) among the newborns from high-level natural radiation areas of Kerala coast, India.

BACKGROUND: The human population residing in monazite bearing Kerala coast are exposed to chronic low dose and low dose rate external gamma radiation due to Th232 deposits in its beach sand. The radiation level in this area varies from < 1.0 to 45.0 mGy/year. This area serves as an ideal source for conducting large-scale epidemiological studies for assessing risk of low dose and low dose rate radiation exposure on human population. The areas with a dose level of ≤1.50 mGy/year are considered as normal level natural radiation areas (NLNRAs) and areas with > 1.50 mGy/year, as high level natural radiation areas (HLNRAs). HLNRAs were further stratified into three dose groups of 1.51-3.0 mGy/year, 3.01-6.00 mGy/year and > 6.0 mGy/year. The present study evaluates the effects of chronic low dose radiation (LDR) exposure on the birth prevalence of Congenital Heart Diseases (CHD) among the live newborns monitored in hospital based prospective study from NLNRAs and HLNRAs of Kerala coast, India. METHODOLOGY: Consecutive newborns were monitored from two hospital units located in the study area for congenital malformations. Referred CHD cases among the newborns screened were confirmed by conducting investigations such as pulse oximetry, chest X-ray, electrocardiogram and echocardiogram etc. RESULTS: Among the newborns screened, 289 CHDs were identified with a frequency of 1.49‰ among 193,634 livebirths, which constituted 6.03% of overall malformations and 16.29% of major malformations. Multiple logistic regression analysis suggested that the risk of CHD among the newborns of mothers from HLNRAs with a dose group of 1.51-3.0 mGy/year was significantly lower as compared to NLNRA (OR = 0.72, 95% CI: 0.57-0.92), whereas it was similar in HLNRA dose groups of 3.01-6.00 mGy/year (OR = 0.55, 95% CI: 0.31-1.00) and ≥ 6.0 mGy/year (OR = 0.96, 95% CI: 0.50-1.85). The frequency of CHDs did not show any radiation dose related increasing trend. However, a significant (P = 0.005) reduction was observed in the birth prevalence of CHDs among the newborns from HLNRA (1.28‰) as compared to NLNRA (1.79‰). CONCLUSION: Chronic LDR exposure did not show any increased risk on the birth prevalence of CHDs from high-level natural radiation areas of Kerala coast, India. No linear increasing trend was observed with respect to different background dose groups. The frequency of CHD was observed to be 1.49 per 1000 livebirths, which was similar to the frequency of severe CHD rate reported elsewhere in India and was much less than the reported frequency of 9 per thousand.

Distinct Levels of Adhesion Energy of In-Situ Grown CuO Nanostructures.

CuO nanostructures were reported for a myriad of applications in diverse areas such as high Tc superconductors, field emitters, catalysts, gas sensors, magnetic storage, biosensors, superhydrophobic surfaces, energy materials etc. In all these applications, structural stability of the nanostructures is very important for efficient functioning of devices with a longer lifetime. Hence, it is necessary to understand the adhesion energy of these nanostructures with their substrates. In this research work, a variety of CuO nanostructures were synthesized directly on Cu foil substrate by varying only the concentration of the reagents. CuO nanostructures, thus grown, were subjected to a nano-scratch test to quantify their adhesion strength with Cu substrate. The adhesion energy was observed to be highest for nanorods and lowest for nanoribbons among all the CuO nanostructures synthesized in this work. Results of this research will be useful in predicting the service life and in improving the efficiency of CuO nanostructure-based devices.

Composite Pheochromocytoma Presenting as Severe Lactic Acidosis and Back Pain: A Case Report.

Pheochromocytoma is a rare, catecholamine secreting tumor arising from chromaffin cells. Presentation of this tumor is highly variable, the most common being hypertension, tachycardia, sweating, and headache. Lactic acidosis and back pain are rare complications of this tumor. We report a 51-year-old gentleman with composite pheochromocytoma, which is rarer than pheochromocytoma, presenting as severe back pain and lactic acidosis.

Comparative study on the efficacy of the UHMWPE surface modification by chemical etching and electrostatic spraying method for drug release by orthopedic implants.

Failure of fixation between bone and implant surface due to bacterial infection, is one of the key challenges in total hip arthroplasty. It might lead to poor implant stability and complex revision surgery. Surface modification of an acetabular cup liner for sustained drug delivery is an effective approach to reduce the biofilms associated infection. The aim of the study is to evaluate the influence of different surface modification technique on drug delivery, mechanical and tribological performances of the acetabular cup liner. Solvent-based etching and electrostatic spray deposition technique was individually used to engineer a thin microporous surface layer on ultra-high molecular weight polyethylene (UHMWPE), which is commercially used as acetabular cup liner in total hip implant. Porous surfaces were filled with drug (gentamicin) containing biodegradable polymer (chitosan) through impregnation process and their efficacy was compared in the intended application. The surfaces, modified by both techniques, have shown lower friction coefficient. The higher wear rates were noticed for electrostatic sprayed coating. Both the modified surfaces have shown slight decrease in hardness and elastic modulus, which may be attributed to improper impregnation of polymer inside porous surface. However, after the release of drug, the solvent-based etched surface regains its mechanical and tribological properties, in similar range to the unmodified UHMWPE surface. Both the modified surfaces have shown an impressive drug release profile and in vitro antibacterial efficacy. The drug release duration was more for electrostatic spray modified surface. Hence, these surfaces modified implant parts shown great promise for fighting against post-surgery bacterial infection.

Sustained drug release from surface modified UHMWPE for acetabular cup lining in total hip implant.

Despite sterilization and aseptic procedure, bacterial infection remains a key challenge in total hip arthroplasties. This fact emphasizes the urgent need for development of new implant systems, which should releases the drug in a controlled manner without sparing its mechanical and tribological properties. In this study, the lining material of the acetabular cup, in total hip implant, has been modified for sustained release of drugs, which should be available throughout the site of implantation to fight the post-operation bacterial infection. A modified solvent based etching and lypolization technique has been used to engineer a thin porous surface layer on ultra-high molecular weight polyethylene (UHMWPE) substrate, which is clinically used as acetabular-cup lining. Gentamicin loaded chitosan solution has been impregnated into modified surface, which suitably gets released over a long period. The main challenge was to keep the mechanical and tribological behavior of this lining material unaffected after the modification. Modified surface offers reduction in friction coefficient and wear rate, by 26% and 19%, respectively, in comparison to UHMWPE, which is encouraging towards the intended application. Hardness and elastic modulus decreases slightly, by 27% and 20%, respectively, possibly due to improper impregnation of chitosan inside porous surface. However, after drug release, the modified surface regains the mechanical and tribological behavior similar to unmodified UHMWPE. Surface modified UHMWPE have shown an impressive release profile for drug up to 26days and released >94.11% of the total drug content. In vitro antibacterial tests have proven that the modified surface of UHMWPE can effectively release the drug and fight against infection. This surface engineered acetabular cup lining is a promising candidate in the area of drug eluting implant, which can bring a significant advancement to the functionality of commercially used orthopedic implants by providing inherent capacity for fighting infections in-vivo.

Quantifying bonding strength of CuO nanotubes with substrate using the nano-scratch technique.

CuO is a narrow bandgap semiconductor demonstrating applications in/as catalysts, gas sensors, adsorbents, and superconductors, and as electrodes of photocells, super-capacitors, and lithium-ion batteries. One-dimensional (1D) CuO nanostructures are of particular interest in most of these device applications, owing to their huge surface area. Strong bonding between nanomaterials and substrate is essential for extended device life. Hence, knowledge about the strength of the nanomaterial-substrate bond is highly desired. In this research work, CuO nanotubes were synthesized directly on a Cu substrate, and its adhesion strength was quantified using the nano-scratch-based technique. The adhesion energy of CuO nanotubes (for 7 h of reaction period) on the Cu substrate was measured to be 82 Jm(-2). The bonding strength can be correlated with the structure of the material. Results of this research will be valuable in analyzing and improving the lifetime of CuO nanotube-based devices, and the technique could be further extended to other 1D transition metal oxide nanostructures.

Sequence analysis of the non-structural 3A and 3C protein-coding regions of foot-and-mouth disease virus serotype Asia1 field isolates from an endemic country.

A total of 18 foot-and-mouth disease virus (FMDV) serotype Asia1 field isolates belonging to two different lineages (including the divergent group) as delineated earlier in VP1-based phylogeny were sequenced in the non-structural 3A and 3C protein-coding regions. The phylogenetic trees representing the regions coding for the non-structural proteins were very similar to that of the structural VP1 protein-coding region. Phylogenetic comparison at 3C region revealed clustering of Asia1 viruses with the isolates of serotypes O, A and C in the previously identified clade. Comparison of amino acid sequences identified lineage-specific signature residues in both the non-structural proteins. Overall analysis of the amino acid substitutions revealed that the 3A coding region was more prone to amino acid alterations than 3C region.

Genetic comparison of large fragment of the 5'untranslated region among foot-and-mouth disease viruses with special reference to serotype Asia1.

Foot-and-mouth disease (FMD), the most economically important disease of cloven-hoofed animals, is endemic in India. Sequence analysis revealed that phylogenetic grouping of type Asia1 field isolates on the basis of the large fragment of the 5'untranslated region (5'LF-UTR) was quite similar to that based on the sequences of the capsid-coding (VP1) region of the same viruses. The existence of two distinct lineages of type Asia1 suggested by the study on the VP1 region was further supported by the detection of a difference in length and predicted secondary structure of the 5'LF-UTR between the two lineages. Sequence variability between the isolates of the two lineages was also observed within the different domains of the internal ribosome entry site (IRES) around conserved motifs like the GNRA,- RAAA,- and the polypyrimidine tract. Certain group and lineage-specific signature nucleotides pertaining to FMDV type Asia1 in the 5'LF-UTR have been identified. The present study shows that the 5'LF-UTR of FMDV serotype Asia1 field isolates are variable in relation to the length and probable secondary structure of the IRES.

Sequence variability in the structural protein-encoding region of foot-and-mouth disease virus serotype Asia1 field isolates.

A total of 30 field isolates of foot-and-mouth disease virus (FMDV) serotype Asia1 belonging to two different lineages and five isolates belonging to a divergent group as delineated earlier in 1D (encodingVP1 protein) gene-based phylogeny were sequenced in the structural protein (P1) coding region. Phylogenetic comparison of these isolates along with some of the published exotic sequences revealed the presence of five different lineages around the world. Similar grouping pattern was observed for the P1 region and 1D gene-based phylogeny, where the Indian isolates were clustered in two genetic lineages. The recently identified divergent group of virus falls into a separate sub-cluster. Similar grouping was also observed in L gene-based phylogeny. Comparison of amino acid sequences identified lineage-specific signature residues in all the structural proteins. Comparison of Asia1 field isolates at the identified key residues of other FMD viruses involved in the formation of the heparan sulfate-binding ligand confirmed many of them to be conserved and the presence of VP3(56) Arg suggested their cell culture adaptation. Although a considerable genetic variation was observed among the isolates of present study, all of them tested in micro-neutralization test were serologically related to the vaccine strain.

Mutation in the 1D gene (VP1) of Foot-and-mouth disease virus serotype Asia1 during serial cytolytic infections in cell culture.

Changes in the nucleotide sequence of the 1D gene of two vaccine strains (IND 63/72 and IND 491/97) of Foot-and-mouth disease virus (FMDV) serotype Asia1 during serial cytolytic infections in cell culture have been analyzed. Sequence comparisons revealed a majority of transition mutations in IND 491/97. The mutation frequency of the 1D gene of IND 491/97 was about 4.5 to 6.0 fold higher than that of IND 63/72. At the amino acids 40-60 and 140-160 regions the mutation frequency was higher compared to the whole VP1. Both viruses showed a constant change at certain residues of the G-H loop region with an accumulation of amino acid replacements during serial cytolytic passages in cell culture. The critical residues (145 and 153) identified previously using mAbs recognizing trypsin-sensitive epitopes were not substituted in the absence of immune selection but changes were observed at positions 142 and 148. Non-reactivity of IND 63/72 after 50(th) passage level onwards with a panel of mAbs indicated an alteration in the antigenic specificity of the virus. Comparison of amino acid sequences in the entire capsid coding region of the naturally occurring field isolates with that of the 50(th) and 100(th) passage level viruses of IND 63/72 revealed that the residues 56 and 74 of VP2 could be involved in mAb binding. The results suggest that fixation of amino acid replacements occurs in VP1 of Asia1 virus, which could play an important role in antigenic variation by modulating different antigenic epitopes located on the surface of the virus.

Spontaneous tendon ruptures in alkaptonuria.

Ochronosis, the musculoskeletal manifestation of alkaptonuria, is known to lead to degenerative changes of the spine and weight-bearing joints. Symptoms related to degeneration of tendons or ligaments with spontaneous ruptures have not previously been reported. Three patients are described with four spontaneous ruptures of either the patellar tendon or tendo Achillis as the first symptom of alkaptonuria.