Optical Tweezers-Based Measurements of Colloidal Forces between Asphaltene Thin Films: Effect of Ultrasonication.

Oil production and processing often involve the treatment of water-in-oil emulsions stabilized by asphaltenes. The asphaltenes adsorb irreversibly at the water-oil interface and, by self-association at the interface, form a viscoelastic film that stabilizes the emulsions mechanically and sterically. Hydrophobic forces associated with these films may also contribute to the emulsion stability. A key step in treating these emulsions is to weaken the asphaltene film at the interface, and one way to do so is with ultrasonic treatment. The effect of ultrasonic waves on the interactions between asphaltene films was investigated at a silica-water interface using optical tweezers. Silica microparticles were aged in asphaltene solutions to form asphaltene coatings on their surfaces. The particles were dispersed in water, and interparticle force measurements were performed with optical tweezers to capture the steric force and hydrophobic force contributions. The asphaltene coating thickness and hydrophobic coefficient (a factor resembling the strength of the hydrophobic interaction) were obtained from fitting these forces. The effect of ultrasonication on the thickness of the asphaltene films on the surfaces of the particles was investigated. No change in the hydrophobic coefficient was observed upon changing the interfacial asphaltene concentration. The asphaltene film thickness increased with the concentration of the asphaltene solution and aging time. After treatment of the dispersion with ultrasonic waves for different durations (between 5 and 40 min), a significant reduction in the coating thickness was observed. This reduction was confirmed by thermogravimetric analysis (TGA) measurements. It is hypothesized that cavitation at the interface removed part of the surface layer of asphaltenes from the coated particles. Based on these findings, we proved that a low-power ultrasound field can effectively break asphaltene-stabilized water-in-oil emulsions.

Central obesity increases risk of breast cancer irrespective of menopausal and hormonal receptor status in women of South Asian Ethnicity.

BACKGROUND: Current evidence suggests that the relationship between obesity and breast cancer (BC) risk may vary between ethnic groups. METHODS: A total of 1633 BC cases and 1504 controls were enrolled in hospital-based case-control study in Mumbai, India, from 2009 to 2013. Along with detailed questionnaire, we collected anthropometric measurements on all participants. We used unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence interval (CI) for BC risk associated with anthropometry measurements, stratified on tumour subtype and menopausal status. RESULTS: Waist-to-hip ratio (WHR) of ≥0.95 was strongly associated with risk of BC compared to WHR ≤0.84 in both premenopausal (OR = 4.3; 95% CI: 2.9-6.3) and postmenopausal women (OR = 3.4; 95% CI: 2.4-4.8) after adjustment for body mass index (BMI). Premenopausal women with a BMI ≥30 were at lower risk compared to women with normal BMI (OR = 0.5; 95% CI: 0.4-0.8). A similar protective effect was observed in women who were postmenopausal for <10 years (OR = 0.6; 95% CI: 0.4-0.9) but not in women who were postmenopausal for ≥10 years (OR = 1.8; 95% CI: 1.1-3.3). Overweight and obese women (BMI: 25-29.9 and ≥ 30 kg/m(2), respectively) were at increased BC risk irrespective of menopausal status if their WHR ≥0.95. Central obesity (measured in terms of WC and WHR) increased the risk of both premenopausal and postmenopausal BCs irrespective of hormone receptor (HR) status. CONCLUSIONS: Central obesity appears to be a key risk factor for BC irrespective of menopausal or HR status in Indian women with no history of hormone replacement therapy.

Novel biodegradable hydrogel sponge containing curcumin and honey for wound healing.

OBJECTIVE: To develop and evaluate a biodegradable superporous hydrogel based wound healing composite of chitosan and alginate incorporated with curcumin and honey. METHOD: A 3(2) factorial design was adopted to optimise the honey-curcumin hydrogel composite sponge (CHS). Sodium alginate and chitosan were dissolved in deionised water and 1% aqueous acetic acid solution at room temperature, respectively. Ethanolic solution of curcumin was poured into the chitosan solution followed by an addition of sodium alginate solution. In situ polymerisation was carried out by adding acrylamide base components to the polymeric solution of curcumin. Finally, honey was added with slow stirring and a sponge was cast on a glass surface by solvent evaporation at 45ºC. The produced sponge was assessed for swelling capacity, moisture loss, tensile strength, biocompatibility, bioadhesion, biodegradation, drug diffusion and wound healing properties. The morphology of CHS was studied by scanning electron microscopy (SEM). RESULTS: The optimised CHS demonstrated a high swelling capacity (111.05 ± 05%), tensile strength (4323gm/mm(2)), in vitro drug diffusion (75.03 ± 3.59%/20days), bioadhesion (20 ± 0.2mg force) and ability of water vapour transmission. A rapid induction of tissue granulation and re-epithelialisation was observed. Time to complete healing (94.14 ± 1.04% wound contraction) was 7 ± 2 days. CONCLUSION: This study has shown that honey-curcumin hydrogel composite sponge can be formulated by a simple mixing and in situ polymerisation method. The hydrogel base provided a dry wound bed due to excellent fluid absorption capacity. Chitosan and honey contributed to effective faster wound healing. We recommend further clinical studies of the soft sponge wound healing composite for diabetic foot or pressure ulcers.

Enhancing neonatal survival: what can we do today?

OBJECTIVE: Neonatal deaths account for 44% of the world's under-5 child mortality. Over half of all neonatal deaths globally occur in preterm babies. Therefore, improving care of a preterm baby is particularly important to reduce under-5 mortality. The objective of this study was to spell out components of care of preterm/low birth weight babies at first level health facility and at first referral unit (FRU) in low resource settings. STUDY DESIGN: We have analyzed weight-wise survivals at two hospitals attached to medical colleges, J.J. Hospital, Mumbai and General Hospital, Talegaon, and at Rural Hospital, Dahanu. There were three-tier interventions: (i) warmth+ feeding and antibiotics, (ii) improved care at birth plus increased oxygen availability and (iii) use of dopamine. J.J. Hospital went through all these stages one after another; General Hospital had all three going simultaneously. The Rural Hospital had a 1+2. RESULTS: During 1978 to 1984, J.J. Hospital saved 50 to 55% very low birth weight (VLBW) babies by providing warmth, feeding and antibiotics. This percentage increased to 56 to 58%, when adequate oxygen and good care at birth was available (1984 to 1989). For babies in the moderately low birth weight category (MLBW), 1500 to 2000 g at birth, the corresponding figures were 56 to 58% and 84 to 86%. The same interventions led to statistically significant decline in MLBW and VLBW categories at General Hospital, Talegaon (2010 to 2013). The Rural Hospital, Dahanu (1987 to 1992) achieved better survival rates in VLBW (61.5%) and MLBW (92.5%) categories with identical interventions and less staff. CONCLUSION: On the basis of our results, we suggest that in resource-limited settings, the first level health facility may be able to look after short-stay babies that weigh more than 1500 g and that have no respiratory distress. The FRU may look after MLBW babies, with or without respiratory distress, and VLBW babies without respiratory distress by giving special care.

Place of birth and risk of gallbladder cancer in India.

CONTEXT: Within India, the incidence of gallbladder cancer (GBC) is characterized by marked geographical variation; however, the reasons for these differences are unclear. AIMS: To evaluate the role of place of birth, length of residence, and effect of migration from high- to low-risk region on GBC development. SETTINGS AND DESIGN: Population-based cancer registries (PBCRs); case-control study. SUBJECTS AND METHODS: Data of PBCRs were used to demonstrate geographical variation in GBC incidence rates. A case-control study data examined the role of birth place, residence length, and effect of migration in etiology of GBC. STATISTICAL ANALYSIS: Rate ratios for different PBCRs were estimated using Chennai Cancer Registry as the reference population. Odds ratios (ORs) for developing GBC in a high-risk region compared to a low-risk region and associated 95% confidence interval (CI) were estimated through unconditional logistic regression models using case-control study. RESULTS: GBC shows marked variation in incidence with risk highest in Northeast regions and lowest in South India. OR of 4.82 (95% CI: 3.87-5.99) was observed for developing GBC for individuals born in a high-risk region compared to those born in a low-risk region after adjusting for confounders. A dose-response relationship with increased risk with increased length of residence in a high-risk region was observed (OR lifetime 5.58 [95% CI: 4.42-7.05]; Ptrend ≤ 0.001). The risk persisted even if study participant migrated from high- to low-risk region (OR = 1.36; 95% CI: 1.02-1.82). CONCLUSIONS: The present study signifies the importance of place of birth, length of stay, and effect of migration from high- to low-risk region in the development of GBC. The data indicate role of environmental and genetic factors in etiology of disease.

Rural urban differences in breast cancer in India.

Context: Breast cancer incidence rates are high in developed countries and much lower in less developed countries including India. Aims: The aim of the following study is to compare breast cancer incidence rates in rural, urban and metro regions of India and to estimate risk of developing breast cancer associated with residence in a rural area. Settings and Design: Descriptive and analytical study design. Materials and Methods: We extracted age adjusted incidence rate from 26 population-based cancer registries and data from hospital-based case-control study to estimate rate and risk ratio for developing breast cancer in an urban region compared with a rural residence. Statistical Analysis: The rate ratios and 95% confidence interval (CI) for developing breast cancer in the urban and metro region compared with rural registry of Barshi were estimated. The odds ratio (OR) and 95% CI for developing breast cancer in women residing in a rural region was estimated by fitting unconditional logistic regression using hospital-based case-control study data. Average annual percentage change in most recent 15 years (1996-2010) for Barshi (rural), Aurangabad (urban), and Mumbai (metro) cancer registry was obtained by fitting a log-linear model using joint point regression. Results: Living first 20 years of life in a rural area reduces the risk of breast cancer (OR = 0.65, 95% CI: 0.56-0.76). Conclusions: The current study demonstrates that lifestyle operative in a rural area is protective against risk of developing breast cancer.

Stability of a charged drop near a conductor wall.

The effect of conductor boundaries on the deformation and stability of a charged drop is presented. The motivation for such a study is the occurrence of a charged conductor drop near a conductor wall in experiments (Millikan-like set-up in studies on Rayleigh break-up) and applications (such as electrospraying, ink-jet printing and ion mass spectroscopy). In the present work, analytical (linear stability analysis (LSA)) and numerical methods (boundary element method (BEM)) are used to understand the instability. Two kinds of boundaries are studied: a spherical, conducting, grounded enclosure (similar to a spherical capacitor) and a planar conducting wall. The LSA of a charged drop placed at the center of a spherical cavity shows that the Rayleigh critical charge (corresponding to the most unstable l = 2 Legendre mode) is reduced as the non-dimensional distance ̂d = (b - a)/a decreases, where a and b are the radii of the drop and spherical cavity, respectively. The critical charge is independent of the assumptions of constant charge or constant potential conditions. The trans-critical bifurcation diagram, constructed using BEM, shows that the prolate shapes are subcritically unstable over a much wider range of charge as [Formula: see text] decreases. The study is then extended to the stability of a charged conductor drop near a flat conductor wall. Analytical theory for this case is difficult and the stability as well as the bifurcation diagram are constructed using BEM. Moreover, the induced charges in the conductor wall lead to attraction of the drop to the wall, thereby making it difficult to conduct a systematic analysis. The drop is therefore assumed to be held at its position by an external force such as the electric field. The case when the applied field is much smaller than the field due to inherent charge on the drop ((a(3)ρg)/(3ε(0)Ψ(2)) ≪ 1 is considered. The wall breaks the fore-aft symmetry in the problem, and equilibrium, predominantly prolate shapes corresponding to the legendre mode, l = 2 , are observed. The deformation increases with increasing charge on the drop. The breakup of the prolate equilibrium shapes is independent of the legendre modes of the initial perturbations. The prolate perturbations are subcritically unstable. Since the equilibrium prolate shapes cannot continuously exchange instability with equilibrium oblate shapes, an imperfect transcritical bifurcation is observed. A variety of highly deformed equilibrium oblate shapes are predicted by the BEM calculations.

Dosimetry of gamma chamber blood irradiator using Gafchromic EBT film.

Gafchromic films are increasingly being used for dosimetry in medical and industrial applications of ionizing radiation because of their favorable characteristics such as self developing in nature, easy to handle, dose rate independent response, insensitivity to normal room lights, high resolution and insensitivity to variation in the environment conditions. The dosimetry measurements using Gafchromic EBT film, Fricke dosimeter and thermoluminescence (TL) dosimeter were carried out on gamma blood irradiators to establish the suitability of Gafchromic EBT film in such applications. The dose rates determined by Gafchromic EBT film, Fricke dosimeter and TL dosimeter powder are found in good agreement to one another within the uncertainty of measurement. The two-dimensional dose distributions determined using Gafchromic EBT film reflects the expected dose distribution inside the sample compartment of the blood irradiator. The results of this study establish Gafchromic EBT film a suitable dosimeter for routine dosimetry on gamma blood irradiators.

Infant palatal obturator.

The occurrence of a congenital cleft palate greatly impedes the habituation of efficient deglutition of an infant, causing aspiration of fluids in the air passage which may lead to complications like bronchopneumonia and infection of the airway and lungs. Inadequate nourishment due to difficulty in feeding affects the health and acts as a stumbling block in the milestones of normal development. Severe nutritional deficiencies further complicate surgical closure at the right time. A palatal obturator given to the infant effectively separates the oral cavity from the nasal cavity and is of great help in feeding till the defect can be surgically repaired.

A humanized, bispecific immunoadhesin-antibody that retargets CD3+ effectors to kill HIV-1-infected cells.

We have developed a humanized, bispecific immunoadhesin-antibody (BsIAb) that targets and kills HIV-infected cells. Comprised of CD4-IgG and humanized anti-CD3-IgG, this BsIAb is bifunctional. First, in targeting, it exploits the natural affinity of CD4 for gp120 to target the BsIAb to HIV-infected cells, and second, it recruits and activates, through its anti-CD3 moiety, cytotoxic T lymphocytes (CTL) to lyse target cells in a non-MHC restricted manner. To produce purified BsIAb from supernantants of transfected mammalian cells, we designed a three-step recovery scheme based on the structural elements of this heterotrimeric protein. The ability of purified BsIAb to specifically lyse HIV-infected target cells was demonstrated using CTL from two different sources: whole peripheral blood lymphocyte (PBL) fractions and pure CTL preparations. In contrast, a human anti-gp120 antibody mediated lysis of HIV-infected target cells only with PBL fractions and not with purified CTL. Moreover, lysis observed in the presence of the human anti-gp120 antibody was completely blocked in the presence of human serum (which competes for Fc gamma receptor binding), whereas BsIAb-mediated lysis of target cells was not affected. We measured the monovalent affinities of BsIAb for HIV-gp120 on infected cells and for CD3 epsilon on CTL. Relative to the bivalent parent molecules, CD4/gp120 affinity in the BsIAb is unchanged, whereas anti-CD3/CD3 is substantially decreased. We further demonstrated by fluorescence microscopy that physical association of CD3+ cells with gp120-expressing cells occurs only in the presence of BsIAb. Thus, the cytocidal activity of BsIAb in the presence of serum reflects its unique ability to recruit CTL as effector cells and highlights a potentially important advantage of this type of construct over antibodies for HIV-directed therapy.

A humanized, bispecific immunoadhesin-antibody that retargets CD3+ effectors to kill HIV-1-infected cells.

HIV infection depletes the immune system of the coordinating functions of CD4+ T cells and APCs, whereas the population of CD8+ CTLs remains largely intact: functional but undirected. We have developed a humanized bispecific immunoadhesin-antibody (BIA) that redirects these remaining T cells to kill HIV-infected cells. This BIA expresses effector cell retargeting via a targeting activity that exploits the natural affinity of CD4 for gp120, and a recruiting activity that employs an anti-CD3 moiety to engage CTLs. The resultant molecule is 97% human in origin. In functional tests, this BIA mediated killing of HIV-infected cells using either pure CTL preparations, or whole PBL fractions that additionally include Fc gamma receptor-bearing large granular lymphocyte effectors. In contrast, a human anti-gp120 Ab induced target lysis via Ab-dependent cellular cytotoxicity (ADCC) only with large granular lymphocyte-containing fractions and not with CTLs. ADCC with this Ab was blocked in human serum, whereas BIA-mediated effector cell retargeting lysis of HIV-infected cells by CTLs was preserved. The affinity of the BIA for HIV-gp120 on infected cells and for CD3 epsilon on CTLs was derived in a flow cytometric Scatchard procedure. Relative to the bivalent parent molecules, CD4/gp120 affinity on cells was unchanged in the BIA (Ka 7 x 10(7) M-1), whereas the anti-CD3 affinity was diminished 50-fold (Ka 2 x 10(6) M-1 vs 1 x 10(8) M-1). Physical association of CD3+ effectors and gp120-expressing targets was confirmed by fluorescence microscopy and was dependent upon the presence of BIA and expression of target gp120. The unimpaired cytocidal activity of the BIA in the presence of serum highlights a potentially important advantage of this type of construct over native Abs for HIV-directed therapy.

An advanced solid support for immunoassays and other affinity applications.

A 6-mm diameter glass bead that has a hydrophilic coating containing epoxy groups has been developed for immunoassays and other affinity applications. These QuantAffinity beads covalently bind protein in the range of 200-400 ng per bead. Derivatization with protein in the presence of high concentrations of potassium phosphate (pH 7.0-8.0) generally gives complete coupling in 16 hours. No preactivation of the support or the protein is necessary. Low nonspecific binding and high retention of bound protein activity are inherent in the system due to the special surface chemistry. Several enzymatic and radioactive immunoassays as well as a biotin-avidin-based assay are described. A use of QuantAffinity beads in small-scale purification is also presented.

From equal access to health care to equitable access to health: a review of Canadian provincial health commissions and reports.

Having achieved equality of access to health care, Canadian policymakers are setting new policy goals, within resource constraints, primarily to achieve equity of access to health. Across the country, provincial royal commissions have explored a number of policy options to achieve this goal. These options are reviewed and critically analyzed within the context of such challenges in health policy as insufficient access to high-technology care and the limits of medical care, and such external challenges as economic and demographic trends, federal-provincial disputes, and ideological beliefs. Particular attention is given to the implications of a broader definition of health and the concept of regional health authorities. Based on the provincial reviews, the authors conclude that Canada wants to achieve equitable access to health. With the shift of health policy away from the formerly protected arena of medical care, achieving equitable access to health will require both an alteration of priorities and values and considerable political will. Canada will be forced to meet these new challenges to maintain current achievements and to make its system even more successful.

Uncoupling of oxidative phosphorylation in rat liver mitochondria following the administration of dimethyl sulphoxide.

A single intraperitoneal injection of 275 mg of dimethyl sulphoxide (DMSO) to rats (100-125 g body weight) effectively uncouples oxidative phosphorylation in liver mitochondria during the period from 2 hr to 5 day post-injection. Higher doses of DMSO are inhibitory to mitochondrial respiration. DMSO has however no uncoupling action on oxidative phosphorylation in vitro. On the other hand, dimethyl sulphide (DMS), a known metabolite of DMSO, brings about the uncoupling effect in vitro. The uncoupling of oxidative phosphorylation by normal mitochondria could also be achieved if these are pre-incubated (30 min at 0 degrees C) with the post-mitochondrial liver supernatant derived from rat injected with DMSO, 2-24 hr prior to sacrifice. These results provide explanation for the observed uncoupling effect exerted by DMSO in vivo.