Antioxidant and Antimicrobial Potential of Natural Colouring Pigment Derived from Bixa orellana L. Seed Aril

Natural colourants with bio-potential are of great commercial demands as we are moving away from the hazardous and toxic chemical dyes. Bixa orellana L. a representative of Bixaceae is rich in bixin and nor-bixin pigments which could be explored for various applications. In the present study, extraction and characterization of bixin and its associated pigment from the aril of the B. orellana L. seeds were performed using various spectroscopic techniques. Spectroscopic analysis and Gas chromatographic profiling of the pigment were performed to understand the present pigments. Toxicity was evaluated through in silico method. The major component, bixin and nor-bixin were proved to be non-toxic, non-carcinogenic and non-mutagenic through in silico methods. The pigment was found to be a potent antioxidant as well as bactericidal against opportunistic bacteria. It was found that bixin extract was a potential antioxidant and bactericidal agent. Hence it could be used for imparting bactericidal potential for cellulosic materials like papers or textiles in biomedical applications.

     

Reliability of direct skin smear microscopy in leprosy

Skin smear direct microscopy is an important tool for diagnosis of leprosy. The study was planned to understand the reproducibility of skin smear reading by a trained technician. Skin smears were collected from known patients of leprosy from the field area. They were stained for acid fast bacilli following the standard cold staining procedure and were read following the Ridley scale. A sample of smears was re-examined on two occasions by the same technician, following blind procedure. There was a systematic under reading on the second occasion, which was attributed to the defective storage of the slides. However, the agreement between second and third examinations was very good (Concordance 81.34%, Kappa 0.74). The finding was confirmed on a repeat examination. It can be concluded that the Direct Skin Smear Microscopy is a reliable and reproducible technique under experimental conditions.     

Cancer‐associated somatic DICER1 hotspot mutations cause defective miRNA processing and reverse‐strand expression bias to predominantly mature 3p strands through loss of 5p strand cleavage

Our group recently described recurrent somatic mutations of the miRNA processing gene DICER1 in non‐epithelial ovarian cancer. Mutations appeared to be clustered around each of four critical metal‐binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3′ end of the 5p miRNA strand of a pre‐mRNA hairpin. To investigate the effects of these cancer‐associated 'hotspot' mutations, we engineered mouse DICER1‐deficient ES cells to express wild‐type and an allelic series of the mutant DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal‐binding site mutations were compared to each other and to wild‐type DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation‐carrying cells were distinct from both wild‐type and DICER1‐deficient cells. Further, miRNA profiles showed that mutant DICER1 results in a dramatic loss in processing of mature 5p miRNA strands but were still able to create 3p strand miRNAs. Messenger RNA (mRNA) profile changes were consistent with the loss of 5p strand miRNAs and showed enriched expression for predicted targets of the lost 5p‐derived miRNAs. We therefore conclude that cancer‐associated somatic hotspot mutations of DICER1, affecting any one of four metal‐binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p strand miRNA. We further propose that this resulting 3p strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Hemolytic and hemoxidative activities in Mycoplasma penetrans

Mycoplasma penetrans is a newly isolated Mollicute from the urine of patients infected with human immunodeficiency virus that demonstrates the capacity to adhere to and invade human cells. A previous report, based on assays with mouse red blood cells (RBCs), indicated that M. penetrans lacked hemolytic activity. In our studies, we incubated different isolates of M. penetrans with various RBC species and observed hemolytic zones surrounding individual mycoplasma colonies. All M. penetrans strains displayed hemolysis after 2 to 3 days of incubation. Hemolytic activity diffused from single colonies, eventually causing complete lysis. Hemolysis was most pronounced with sheep RBCs, followed by horse, chicken, and human cells. Furthermore, hemolytic activity was demonstrable in both intact mycoplasma cell preparations and spent culture supernatant. However, unlike intact mycoplasmas, the hemolytic activity in the supernatant was dependent on the reducing agent, cysteine. In addition to hemolysis, a brown precipitate was closely associated with mycoplasma colonies, suggesting oxidation of hemoglobin. Absorption spectra indicated that hemoglobin was oxidized to methemoglobin, and the addition of catalase demonstrated H(2)O(2)-mediated hemoxidation. Other experiments suggested that hemoxidation enhanced total hemolysis, providing the first evidence of both hemolytic and hemoxidative activities in M. penetrans.     

Abdominal vagotomy attenuates interleukin-1β-induced nitric oxide release in the paraventricular nucleus region in conscious rats

Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO₂⁻) and nitrate (NO₃⁻) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO₂⁻ and NO₃⁻ levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region.     

DA-EPOCH-R in Aggressive CD 20 Positive B Cell Lymphomas: Real-World Experience

Recent reports have shown that excellent survival outcomes can be achieved in adult Burkitt’s lymphoma with the use of DA-EPOCH-R regimen. When compared to earlier intense pediatric-type protocols, this regimen is less toxic. There are limited reports available on the use of this regimen outside the context of clinical trials. We analyzed the outcomes of patients who were treated with the DA-EPOCH-R regimen [Burkitt’s lymphoma (BL), primary mediastinal B cell lymphoma (PMBCL) and HIV-positive patients with diffuse large B cell lymphoma (DLBCL)] at our center over a 3 year period. Baseline characters, responses, and toxicity data was captured from records. Event-free survival (EFS—from therapy initiation till occurrence of event (non-achievement of complete response or relapse) and overall survival (OS—from therapy initiation till death due to any cause) were estimated using Kaplan–Meier method. Among 41 patients [median age 40 years (18–76)], the following diagnoses were included-HIV negative patients (N = 29): BL (N = 24), PMBCL (N = 5); HIV positive patients (N = 12): BL (N = 8), and DLBCL (N = 4). Among those with BL, majority had stage III/IV disease (N = 21/32, 65%). At the completion of planned therapy, 33 had achieved CR (81%). One patient died due to toxicity. The actuarial EFS and OS at 2 years were 80 and 77% respectively for all patients. The OS at 2 years was 100% for PMBCL, 80% for BL and 50% for HIV-positive DLBCL. Majority of the failures in BL were in patients with advanced disease. DA-EPOCH-R can be used in real-world setting and allows treatment of older patients with BL.     

Flowering in bursting bubbles with viscoelastic interfaces

The lifetime of bubbles, from formation to rupture, attracts attention because bubbles are often present in natural and industrial processes, and their geometry, drainage, coarsening, and rupture strongly affect those operations. Bubble rupture happens rapidly, and it may generate a cascade of small droplets or bubbles. Once a hole is nucleated within a bubble, it opens up with a variety of shapes and velocities depending on the liquid properties. A range of bubble rupture modes are reported in literature in which the reduction of a surface energy drives the rupture against inertial and viscous forces. The role of surface viscoelasticity of the liquid film in this colorful scenario is, however, still unknown. We found that the presence of interfacial viscoelasticity has a profound effect in the bubble bursting dynamics. Indeed, we observed different bubble bursting mechanisms upon the transition from viscous-controlled to surface viscoelasticity-controlled rupture. When this transition occurs, a bursting bubble resembling the blooming of a flower is observed. A simple modeling argument is proposed, leading to the prediction of the characteristic length scales and the number and shape of the bubble flower petals, thus paving the way for the control of liquid formulations with surface viscoelasticity as a key ingredient. These findings can have important implications in the study of bubble dynamics, with consequences for the numerous processes involving bubble rupture. Bubble flowering can indeed impact phenomena such as the spreading of nutrients in nature or the life of cells in bioreactors.

When residing in Newtonian fluids, bubble rupture proceeds with features that are shown in Fig. 1. Different dynamics are observed depending on the capillary number, Ca=u η/γ, where u is the experimentally measured characteristic retraction speed of the film, η is the liquid viscosity, and γ is the surface tension between the liquid and gas, and the Reynolds number, Re=ρuRbubble/η, where ρ is the liquid density, and Rbubble is the bubble radius (1–7). Fig. 1 A–D report observed bubble ruptures in the different regimes previously discussed in the literature: 1) for Re≪1, viscous forces are larger than inertial and surface forces, resulting in a very slow hole opening (8) (Fig. 1A); 2) when Re>1, the hole opens up much more quickly (9), and a toroidal rim (Fig. 1B) is subjected to an azimuthal instability, which leads to fingering and, possibly, jetting (Fig. 1 B–D), depending on the corresponding Ca value. If Ca≫1, the rim is stable and folds upward (10); otherwise, inertial instabilities break it into pieces with a characteristic length scale, d=Rbubbleh, where h is the film thickness (11).Open in a separate windowFig. 1.Bubble bursting dynamics. (A) Low Re. (B and C) High Ca and high Re. (D) Low Ca and high Re. (E) Low Ca and high Re with intermediate interfacial viscoelasticity (20 mg/mL of BSA). (F) Low Ca and high Re with high interfacial viscoelasticity (50 mg/mL of BSA). (G) Bubble rupture as functions of time for different concentrations of BSA. Increasing the concentration of BSA leads to an increase in the surface viscoelasticity, and the bubble bursting dynamics change. The concentration of 20 mg/mL is identified as the limit above which flowering occurs. The number of petals, 10 at 20 mg/mL, decreases to 5 when the concentration of BSA is increased to 50 mg/mL. The bursting time (from the puncture to complete film retraction) increases when BSA is added, and it changes from 1.5 ms at 0.1 mg/mL to 2.7 ms at 50 mg/mL.Here, we report evidence of the effect of surface viscoelasticity in bubble rupture dynamics. Surface viscoelasticity is adjusted by adding a surface-active material to the bulk and modulating its concentration and chemistry. We chose bovine serum albumin (BSA) proteins (12, 13), as they are known to form highly viscoelastic surface layers. At low concentrations, BSA molecules are adsorbed at the air/water interface with their major axis parallel to the surface. No protein denaturation occurs, and the molecules retain their globular conformation. As the concentration of BSA increases, a primary monolayer achieves full surface coverage, and a secondary monolayer appears, extending into the aqueous phase (14, 15). Adsorbed protein molecules are connected by interprotein contacts forming an interconnected network within the adsorbed layers (16). Upon compression, globular proteins, such as BSA, respond as deformable spheres, thereby being capable of storing elastic energy (yielding high storage moduli) (17). Many examples can be found in the literature in which the addition of surfactants to the protein solution can drastically change surface properties, giving an unlimited variety of model systems to achieve desired surface properties with a straightforward tuning of the surfactant concentration (18).     

Altered airway responsiveness in CD38-deficient mice

Cyclic ADP-ribose (cADPR) mobilizes calcium from intracellular stores and contributes to agonist-induced intracellular calcium elevation in airway smooth muscle (ASM). In this study we determined the functional role of CD38/cADPR signaling in the regulation of airway tone using CD38 deficient (cd38(-/-)) mice. The responsiveness to different doses of methacholine, as determined by changes in lung resistance and dynamic compliance, was significantly (P < or = 0.05) lower in cd38(-/-) mice compared with wild-type controls. To determine the mechanism responsible for the reduced responsiveness, we measured the intracellular calcium responses to contractile agonists in ASM cells. In ASM cells isolated from cd38(-/-) mice, the intracellular calcium responses to acetylcholine and endothelin-1 were significantly lower than in controls. Pretreatment of ASM cells with a cADPR antagonist resulted in attenuated intracellular calcium responses to endothelin-1 in cells isolated from wild-type mice, but not in those isolated from the cd38(-/-) mice. Very low cADPR levels and no detectable ADP-ribosyl cyclase activity were observed in lung tissue from cd38(-/-) mice, suggesting that CD38 is a critical source for cADPR synthesis. The results of the present study demonstrate that CD38/cADPR contributes to airway smooth muscle tone and responsiveness through its effects on agonist-induced elevation of intracellular calcium in ASM cells.     

Multisite Study of Cryptosporidiosis in Children with Diarrhea in India

Cryptosporidium spp., a common cause of diarrhea in children, were investigated in the first multisite study in India. Diarrheal stools from hospitalized children aged <5 years from Delhi, Trichy, and Vellore were analyzed by microscopy, PCR-restriction fragment length polymorphism (RFLP), and/or sequencing at the small-subunit (SSU) rRNA and Cpgp40/15 loci for species determination and subgenotyping, respectively. Seventy of 2,579 (2.7%) children, 75% of whom were <2 years old, had cryptosporidial diarrhea as determined by microscopy. Genotyping and subgenotyping showed that Cryptosporidium hominis was the most commonly identified species (59/67 children), and subgenotypes Ie, Ia, Ib, and Id were common in all centers. A novel C. parvum subgenotype, IIn, was identified in Vellore. Meteorological analysis revealed a higher rate of cryptosporidial positivity during hotter and drier weather in Delhi.Cryptosporidium spp. are an important cause of endemic parasitic diarrhea in children in developing countries. In addition to causing symptoms associated with watery diarrhea, vomiting, and weight loss, early childhood cryptosporidiosis has been shown by studies to be associated with subsequent faltering of growth (reviewed in reference 11). Cryptosporidium hominis and C. parvum cause the majority of infections in children in developing countries, with C. hominis predominating and occasional reports of infection with zoonotic species such as C. felis, C. canis, C. meleagridis, and C. muris (30). C. hominis infection has been found to be associated with greater levels of oocyst shedding (4) and longer durations of oocyst shedding (31) and diarrhea (15) than C. parvum infection. In a recent community-based study in Vellore, we found increased levels of severity of diarrhea in C. hominis-infected children compared to the levels observed in children infected with other species (1).Cryptosporidium spp. have been classified into several distinct subgenotypes based on extensive polymorphisms in the Cpgp40/15 (also referred to as GP60) locus by use of PCR-restriction fragment length polymorphism (RFLP) or sequencing of PCR products (reviewed in reference 30).A number of studies from India have reported Cryptosporidium spp. in diarrheal stool samples from children, with positivity rates of up to nearly 20% (17) and asymptomatic infection rates of up to 10% (19), using stool microscopy for detection. However, only three studies have used molecular techniques for identification of cryptosporidiosis in children in India (9, 13, 22), suggesting that the actual infection rates may be significantly higher. In a previous hospital-based study in Vellore, we that found that PCR (15.2%) identified more than 3 times the number of cases of cryptosporidial diarrhea than microscopy (4.4%) (2). The aim of the present study was to identify the Cryptosporidium species and Cpgp40/15 subgenotypes associated with cryptosporidial diarrhea in hospitalized children from 3 centers in the country, since no studies have examined cryptosporidiosis using the same methods in more than one location.