Bimetallic PdAg nanoparticle arrays from monolayer films of diblock copolymer micelles

The self-assembly technique provides a highly efficient route to generate well-ordered structures on a nanometer scale. In this paper, well-ordered arrays of PdAg alloy nanoparticles on flat substrates with narrow distributions of particle size (6-7 nm) and interparticle spacing (about 60 nm) were synthesized by the block copolymer micelle approach. A home-made PS-b-P4VP diblock copolymer was prepared to obtain a micellar structure in toluene. Pd and Ag salts were then successfully loaded in the micellar core of the PS-b-P4VP copolymer. A self-assembled monolayer of the loaded micelles was obtained by dipping the flat substrate in the solution. At this stage, the core of the micelles was still loaded with the metal precursor rather than with a metal. Physical and chemical reducing methods were used to reduce the metal salts embedded in the P4VP core into PdAg nanoparticles. HRTEM and EDX indicated that Pd-rich PdAg alloy nanoparticles were synthesized by chemical or physical reduction; UV-visible spectroscopy observations confirmed that metallic PdAg nanoparticles were quickly formed after chemical reduction; XPS measurements revealed that the PdAg alloy nanoparticles were in a metallic state after a short time of exposure to O2 plasma and after hydrazine reduction.

Non-diabetic renal disease in type 2 diabetes mellitus: Study of renal - retinal relationship

Diabetic nephropathy (DN) has become the leading cause of end-stage renal disease worldwide. Non-diabetic renal disease (NDRD), is known to occur in diabetic patients. The renal and retinal relationship in type 2 diabetes mellitus (T2DM) with nephropathy is not uniform. This study was carried to study the histological spectrum of nephropathy in type 2 diabetic patients with proteinuria and its relationship with diabetic retinopathy (DR). Total 31 (males - 26; females - 5) proteinuric type 2 diabetic patients were studied. Average age of patients was 50.7 years. Nephrotic syndrome was noted in 21 (67.7%) patients. Overall, isolated DN, NDRD and NDRD superimposed on DN (mixed lesion) were observed in 12 (38.7%), 13 (41.9%) and 6 (19.4%) cases, respectively. DR was absent in 21/31 (67.7%) cases. The spectrum of nephropathy in patients without DR included: DN in 6 (28.57%), NDRD in 12 (57.14%) and mixed lesion in 3 (14.29%). Kidney histology in patients with DR (n-10) revealed DN in 6 (60%), NDRD in 1 (10%) and mixed lesion in 3 (30%) patients. Thus, absence of DR favors NDRD but does not exclude DN because isolated DN was noted in 28.57% cases in absence of DR. Similarly biopsy proven NDRD (pure NDRD; 10% and mixed lesion; 30%) was noted in 40% of cases in presence of DR. In summary, patients with T2DM had higher incidence of NDRD. DR is less frequent (32.3%) in type 2 diabetes and is a poor predictor of type of nephropathy. Hence, renal biopsy is essential for precise diagnosis of nephropathy in patients with T2DM.

Investigation of probiotic bacteria as dental caries and periodontal disease biotherapeutics

Oral diseases, specifically dental caries and periodontal disease, are characterised by increases in pathogenic microorganisms, increased demineralisation and increased inflammation and levels of inflammatory markers. Despite the therapeutic strategies, oral diseases have elevated prevalence rates. Recent work has demonstrated that probiotic bio-therapeutics can decrease oral pathogen counts, including caries-causing Streptococcus mutans and oral inflammation. The aim of this work was to investigate putative probiotic bacteria, selected for S. mutans inhibition and for their oral health-promoting characteristics. The probiotic bacteria were screened for S. mutans inhibition, probiotic bacteriocin activity, salivary pH modulation, probiotic nutrient (sucrose) competition, probiotic co-aggregation with S. mutans, bacterial attachment to oral epithelial keratinocytes, bacterial nitric oxide production and bacterial antioxidant activity. The results indicate that Lactobacillus reuteri strains NCIMB 701359, NCIMB 701089, NCIMB 702655 and NCIMB 702656 inhibited S. mutans to non-detectable levels (<10 cfu/ml). L. reuteri strains also demonstrated the highest antioxidant capacity of the tested strains (7.73-13.99 µM Trolox equivalents), suggesting their use as both caries and periodontal disease therapeutics. Although Lactobacillus fermentum NCIMB 5221 inhibited S. mutans at lower levels, it significantly buffered the pH (4.18) of saliva containing S. mutans, co-aggregated with S. mutans (10.09%), demonstrated high levels of sucrose consumption (138.11 mM) and successfully attached to gingival epithelial cells (11%). This study identified four L. reuteri strains and one L. fermentum strain to be further investigated as oral disease biotherapeutics.

Acute kidney injury in patients with human immunodeficiency virus infection

Acute kidney injury (AKI) is an important cause of hospitalization and morbidity in human immunodeficiency virus (HIV)-positive patients. However, the data on AKI in such patients is limited. The aim of the present study was to analyze the incidence, causes and outcome of AKI in HIV-positive patients from our antiretroviral therapy centre. All HIV-positive patients were evaluated for evidence of clinical AKI. AKI was noted in 138/3540 (3.9%) patients. Of 138 AKI patients, 96 (69.6%) had acquired immuno deficiency syndrome and 42 (30.4%) were HIV seropositive. Majority of AKI patients belonged to AKI network (AKIN) Stage II (42%) or III (48.5%) at presentation. Prerenal, intrinsic and postrenal AKI were noted in 53.6%, 44.2% and 2.2% of cases, respectively. Hypovolemia (44.2%) and sepsis (14.5%) contributed to AKI in vast majority of cases. AKI was multifactorial (volume depletion, sepsis and drugs) in 39% of patients. Acute tubular necrosis (ATN) was the most common intrinsic lesion. Acute interstitial nephritis and diffuse endocapillary proliferative glomerulonephritis were noted in five and two cases, respectively. In-hospital mortality was 24.64%. Lower CD4 count, decreased serum albumin level and Stage 4 WHO disease were associated with higher mortality. At 3 months or more follow-up complete recovery of renal function, chronic kidney disease Stage 3-5 and progression to end stage renal disease were noted in 58.69%, 14.5% and 2.2% of cases, respectively. Thus, prerenal factors and ischemic ATN were the most common cause of AKI in HIV-infected patients. Recovery of renal function was seen in 59% of cases, but AKI had high in-hospital mortality.

Impact of killer immunoglobulin-like receptor-human leukocyte antigens ligand incompatibility among renal transplantation

Killer immunoglobulin-like receptor (KIR) gene shows a high degree of polymorphism. Natural killer cell receptor gets activated once they bind to self-human leukocyte antigens (HLAs) with specific ligand. KIR gene and HLA ligand incompatibility due to the presence/absence of KIR in the recipient and the corresponding HLA ligand in the allograft may impact graft survival in solid organ transplantation. This study evaluates the effect of matches between KIR genes and known HLA ligands. KIR genotypes were determined using sequence specific primer polymerase chain reaction. Presence of certain KIR in a recipient, where the donor lacked the corresponding HLA ligand was considered a mismatch. The allograft was considered matched when both KIR receptor and HLA alloantigen reveald compatibility among recipient and donor. The data revealed better survival among individuals with matched inhibitory KIR receptors and their corresponding HLA ligands (KIR2DL2/DL3-HLAC2, KIR3DL1-HLABw4). On the contrary, no adverse effect was seen for matched activating KIR receptors and their corresponding HLA ligands. One of the activating gene KIR2DS4 showed risk (P = 0.0413, odds ratio = 1.91, 95% confidence interval = 1.02-3.57) association with renal allograft rejection. We conclude that the presence of inhibitory KIR gene leads to better survival; whereas activating motifs show no significant role in renal allograft survival.

Ex vivo electrical impedance measurements on excised hepatic tissue from human patients with metastatic colorectal cancer

Point-wise ex vivo electrical impedance spectroscopy measurements were conducted on excised hepatic tissue from human patients with metastatic colorectal cancer using a linear four-electrode impedance probe. This study of 132 measurements from 10 colorectal cancer patients, the largest to date, reports that the equivalent electrical conductivity for tumor tissue is significantly higher than normal tissue (p < 0.01), ranging from 2-5 times greater over the measured frequency range of 100 Hz-1 MHz. Difference in tissue electrical permittivity is also found to be statistically significant across most frequencies. Furthermore, the complex impedance is also reported for both normal and tumor tissue. Consistent with trends for tissue electrical conductivity, normal tissue has a significantly higher impedance than tumor tissue (p < 0.01), as well as a higher net capacitive phase shift (33° for normal liver tissue in contrast to 10° for tumor tissue).

Histone demethylases and control of gene expression in plants

Covalent histone modifications, chromatin remodeling and incorporation of histone variants regulate the dynamics of chromatin structure. Among covalent histone modifications, histone methylation mediates by histone methylases that influence the gene expression in heterochromatin silencing, genomic imprinting and transcription. In contrast to methylases, histone demethylases remove the methyl groups from lysine or arginine residues of histones and have enormous impact on gene expression via modified chromatin structures. Two types of histone lysie demethylases have been identified, including lysine specific demethylases 1 (LSD1) and Jmj (Jumonji) domain containing family proteins. The human demethyliminase (PADI4) converts monomethyl arginine residue to citrulline by the arginine demethylimination. In this review we summarize recent advances to understand the mechanism of demethylases in regulation of plant gene expression. In addition we are highlighting the function of four human like LSD1 (LDL) and jmj domain containing genes of Arabidopsis that regulate the defense related, flowering controlling and brassinosteroid response genes.

Protective effects of Eugenia jambolana extract versus N-acetyl cysteine against cisplatin-induced damage in rat testis

To assess the protective effects of Eugenia jambolana extract (EJE) or N-acetyl cysteine (NAC) on testis, cisplatin (CIS, 5 mg kg(-1) bw, single dose) was administered either alone or along with EJE (25 mg kg(-1) bw, alternate day) or NAC (150 mg kg(-1) bw, Day 1 and 4) for 7 days. Significant alterations in serum LH, FSH and testosterone were observed in CIS group which were effectively modulated by EJE or NAC supplementation. Upregulation of 3β-HSD gene indicated the rise in functional Leydig cells. This was further confirmed from the identical improvement in hCG-stimulated testosterone production in isolated Leydig cells. Reduction in oxidative stress was associated with restoration of total antioxidant capacity and glutathione levels, and activation of antioxidant enzymes, SOD, catalase, glutathione s-transferase (GST) and glutathione reductase (GR). CIS-induced apoptosis of germ and Leydig cells was contained by both NAC and EJE intervention by effective modulation of apoptotic markers in the extrinsic, intrinsic and other pathways of metazoan apoptosis. Taken together, the study findings establish the potential of EJE as a therapeutically better antioxidant than NAC for use in curtailing the adverse effects of anticancer drugs on testicular function.