Principal component analysis for minimal model identification of a noise-affected fermentation: application to streptokinase

Principal component analysis (PCA) has been applied to a fed-batch fermentation for the production of streptokinase to identify the variables which are essential to formulate an adequate model. To mimic an industrial situation, Gaussian noise was introduced in the feed rate of the substrate. Both in the presence and in the absence of noise, the same five variables out of seven were selected by PCA. The minimal model trained separately without and with noise was able to predict satisfactorily the course of the fermentation for a condition not employed in training. These observations attest the suitability of PCA to formulate minimal models for industrial scale fermentations.     

Detection of microRNAs in dried serum blots

We observed the preservation of microRNAs in unrefrigerated dried serum blots. Preservation was not adversely affected by drying or storing at 37, 45, or 60 °C instead of room temperature, but it was harmed when blots were dried incompletely before storage. Preservation of microRNAs in serum was not diminished if, instead of being kept frozen at −80 °C, it was stored as dried blots at room temperature for 5 months or at 37 °C for 4 weeks. Thus, dried blots can be a convenient and safer way to save, transport, and store serum for microRNA assays.     

Spectral analysis of the effect of inflow noise on a fed-batch fermentation for recombinant β-galactosidase

The fermentative production of β-galactosidase from Escherichia coli CSH50 containing the plasmid pOU140 is mechanistically complex and difficult to model in a nonideal bioreactor. A spectral analysis has been done for a fed-batch fermentation with Gaussian disturbances in the feed stream. Inflow noise converts a smooth operation into aperiodic motion, as observed in some chemical reactions also. The disturbances also cause significant differences in the frequency responses of intra-cellular (plasmid DNA and β-galactosidase) and extra-cellular (concentration and mass fraction of recombinant cells) variables, whose implications are discussed.     

Effect of picroliv on low density lipoprotein receptor binding of rat hepatocytes in hepatic damage induced by paracetamol.

Picroliv from root and rhizome of Picrorhiza kurroa showed reversal of low density lipoprotein (LDL) binding to paracetamol-induced damaged hepatocytes of rats. Changes in levels of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase, conjugated dienes and lipids of hepatocytes were significantly prevented by picroliv at different doses. The effect of picroliv on enzyme levels, LDL receptor binding and lipids in damaged hepatocytes was found to be comparable to silymarin, a known hepatoprotective agent.     

Analysis of bifurcations in continuous fermentation using recombinant microorganisms with delayed responses

When the feed rate to a fermenter is varied periodically in order to favor the growth of plasmid-containing cells, a transition may occur from the starting stationary state to another state. The resulting state may be constant or oscillatory. A generalised model based on the adaption times of plasmid-free and plasmid-harboring cells has been used. Analytical conditions have been derived for bifurcation from one nonoscillatory state to another or to an oscillatory state (Hopf bifurcation). The frequency of oscillation is shown to have an upper bound, which can be controlled by manipulating certain process parameters. The production of tryptophan synthetase by the plasmid pPLc23trpAl in E. coli is used as an example to determine the nature of the Hopf bifurcations.     

Crocodilian Nest in a Late Cretaceous Sauropod Hatchery from the Type Lameta Ghat Locality,Jabalpur, India

The well-known Late Cretaceous Lameta Ghat locality (Jabalpur, India) provides a window of opportunity to study a large stable, near shore sandy beach, which was widely used by sauropod dinosaurs as a hatchery. In this paper, we revisit the eggs and eggshell fragments previously assigned to lizards from this locality and reassign them to crocodylomorphs. Several features point to a crocodilian affinity, including a subspherical to ellipsoidal shape, smooth, uneven external surface, discrete trapezoid shaped shell units with wide top and narrow base, basal knobs and wedge shaped crystallites showing typical inverted triangular extinction under crossed nicols. The crocodylomorph eggshell material presented in this paper adds to the skeletal data of these most probably Cretaceous-Eocene dryosaurid crocodiles.     

Antihistaminic activity of quinethindole: a 2-substituted pyrazinopyridoindole derivative.

Quinethindole, a 2-substituted pyrazinopyridoindole, showed specific antihistaminic (H1) activity in various in vivo and in vitro test models. It also inhibited antigen-induced contraction of ileum of sensitized guinea pig. The antihistaminic activity was of competitive nature.     

Metabolic Syndrome Is Associated with Increased Oxo-Nitrative Stress and Asthma-Like Changes in Lungs

Epidemiological studies have shown an increased obesity-related risk of asthma. In support, obese mice develop airway hyperresponsiveness (AHR). However, it remains unclear whether the increased risk is a consequence of obesity, adipogenic diet, or the metabolic syndrome (MetS). Altered L-arginine and nitric oxide (NO) metabolism is a common feature between asthma and metabolic syndrome that appears independent of body mass. Increased asthma risk resulting from such metabolic changes would have important consequences in global health. Since high-sugar diets can induce MetS, without necessarily causing obesity, studies of their effect on arginine/NO metabolism and airway function could clarify this aspect. We investigated whether normal-weight mice with MetS, due to high-fructose diet, had dysfunctional arginine/NO metabolism and features of asthma. Mice were fed chow-diet, high-fat-diet, or high-fructose-diet for 18 weeks. Only the high-fat-diet group developed obesity or adiposity. Hyperinsulinemia, hyperglycaemia, and hyperlipidaemia were common to both high-fat-diet and high-fructose-diet groups and the high-fructose-diet group additionally developed hypertension. At 18 weeks, airway hyperresponsiveness (AHR) could be seen in obese high-fat-diet mice as well as non-obese high-fructose-diet mice, when compared to standard chow-diet mice. No inflammatory cell infiltrate or goblet cell metaplasia was seen in either high-fat-diet or high-fructose-diet mice. Exhaled NO was reduced in both these groups. This reduction in exhaled NO correlated with reduced arginine bioavailability in lungs. In summary, mice with normal weight but metabolic obesity show reduced arginine bioavailability, reduced NO production, and asthma-like features. Reduced NO related bronchodilation and increased oxo-nitrosative stress may contribute to the pathogenesis.     

Size- and Age-Dependent Neurotoxicity of Engineered Metal Nanoparticles in Rats

Earlier we showed that chronic administration of engineered nanoparticles (NPs) from metals, e.g., Cu, Ag, or Al (50–60 nm, 50 mg/kg, i.p. daily for 1 week) alter blood–brain barrier (BBB) disruption and induce brain pathology in adult rats (age 18 to 22 weeks). However, effects of size-dependent neurotoxicity of NPs in vivo are still largely unknown. In present investigation, we examined the effects of different size ranges of the above-engineered NPs on brain pathology in rats. Furthermore, the fact that age is also an important factor in brain pathology was also investigated in our rat model. Our results showed that small-sized NPs induced the most pronounced BBB breakdown (EBA +480 to 680 %; radioiodine +850 to 1025 %), brain edema formation (+4 to 6 %) and neuronal injuries (+30 to 40 %), glial fibrillary acidic protein upregulation (+40 to 56 % increase), and myelin vesiculation (+30 to 35 % damage) in young animals as compared to controls. Interestingly, the oldest animals (30 to 35 weeks of age) also showed massive brain pathology as compared to young adults (18 to 20 weeks old). The Ag and Cu exhibited greater brain damage compared with Al NPs in all age groups regardless of their size. This suggests that apart from the size, the composition of NPs is also important in neurotoxicity. The very young and elderly age groups exhibited greater neurotoxicity to NPs suggests that children and elderly are more vulnerable to NPs-induced brain damage. The NPs-induced brain damage correlated well with the upregulation of neuronal nitric oxide synthase activity in the brain indicating that NPs-induced neurotoxicity may be mediated via increased production of nitric oxide, not reported earlier.