Self-Assembly of Colloidal Particles

Colloidal dispersions are suspensions of micron-sized solid particles in a solvent like water or oil. Self-assembly is a widely used approach to create ordered structures of colloidal particles by engineering the inter-colloid potential. This article illustrates how entropy drives disorder to order transitions in a colloidal assembly.     

Lead: Tiny but Mighty Poison

The documentation of lead toxicity (plumbism) dates back to the times when man learnt its various applications. This versatile heavy metal is non-degradable and its ability to get accumulated in the body that goes undiagnosed, makes it a serious environmental health hazard. Lead is now known to affect almost every organ/tissue of the human body. With irreversible effects on neurobiological development of young children and foetus, its toxicity has lasting implications on the human life. Outlining the symptoms, diagnosis and treatment therapy for lead poisoning, the present review elaborates the pathophysiological effects of lead on various organs. This will be of immense help to the health professionals so as to inculcate a better understanding of the lead poisoning which otherwise is asymptomatic. With chelation therapy being the classic path of treatment, new strategies are being explored as additive/adjunct therapy. It is now understood that lead toxicity is completely preventable. In this regard significant efforts are in place in the developed countries whereas much needs to be done in the developing countries. Spreading the awareness amongst the masses by educating them and reducing the usage of lead following stricter industry norms appears to be the only roadmap to prevent lead poisoning. Efforts being undertaken by the Government of India and other organisations are also mentioned.     

Serum lipids, lipoproteins and sex-hormone binding globulin in breast cancer

Serum levels of various lipid parameters, i.e., triglycerides, total cholesterol, alpha lipoprotein or high density lipoprotein (HDL)-cholesterol and beta lipoprotein or low density lipoprotein (LDL)-cholesterol were measured in a total of 138 histologically proven cases of breast cancer along with 146 control women. The mean levels of serum triglycerides, total cholesterol and LDL-cholesterol were found to be significantly higher in breast cancer cases as compared to controls. However, lower mean levels of serum HDL-cholesterol and sex-hormone binding glubulin (SHBG) were observed in breast cancer patients than the control subjects. The results indicate a probable relation between serum lipids and the activity of sex-hormones. Moreover, the study reflects an overall disturbance of lipid metabolism in the pathological process of breast cancer.     

On-chip microelectrode impedance analysis of mammalian cell viability during biomanufacturing

The characterization of cell viability is a challenging task in applied biotechnology, as no clear definition of cell death exists. Cell death is accompanied with a change in the electrical properties of the membrane as well as the cell interior. Therefore, changes in the physiology of cells can be characterized by monitoring of their dielectric properties. We correlated the dielectric properties of industrially used mammalian cells, sedimented over interdigitated microelectrodes, to the AC signal response across the chip. The voltage waveforms across the electrodes were processed to obtain the circuit impedance, which was used to quantify the changes in cell viability. We observed an initial decrease in impedance, after which it remained nearly constant. The results were compared with data from the dye exclusion viability test, the cell specific oxygen uptake rate, and the online viable cell density data from capacitance probes. The microelectrode technique was found to be sensitive to physiological changes taking place inside the cells before their membrane integrity is compromised. Such accurate determination of the metabolic status during this initial period, which turned out to be less well captured in the dye exclusion tests, may be essential for several biotechnology operations.     

Type-2 diabetes related intermediate phenotypic traits in north Indian diabetics

Asian Indians are known to be at a higher risk of developing T2DM, but the underlying genetic factor in this population is still not well understood. T2DM is a complex genetic trait and assessment of disease related intermediate phenotypic traits is an important initial step towards any systematic genomic study. Therefore, in the present study we have assessed diabetes related intermediate phenotypic traits of insulin secretion and insulin resistance in the patients belonging to this population. The study included 157 T2DM patients of either sex ranging in age from 45–80 years and 84 non-diabetic subjects with no family history of diabetes, ranging in age from 45 to 75 years served as controls. Intermediate phenotypic traits studied were BMI, W: H ratio, fasting free fatty acid level and Insulin resistance and secretion. Diabetics were found to have significantly higher W: H ratio (p<0.001), FFA (p<0.001) and HOMA-R (p<0.001) as compared to non-diabetics. However, there was no significant difference in their BMI and HOMA-β. There was a positive correlation between FFA level and HOMA-R among diabetics, but not among controls. These findings suggest that in abdominal obesity FFA mediated insulin resistance is an important causative factor underlying T2DM in this population. Moreover, comparable HOMA-β in diabetics reflects compensatory insulin hyper secretion in these subjects. There is a need to examine relative contribution and precise nature of genetic factor in their tendency for central obesity, free fatty acidemia and insulin resistance.