Inhibition of copper-induced aggregation of human γD-crystallin by a diimine molecule and investigations on their molecular interactions

Communicated by Ramaswamy H. Sarma     

Study of oxidative stress in isoniazid-induced hepatic injury in young rats with and without protein-energy malnutrition

The role of oxidative stress as a mechanism of hepatic injury caused by isoniazid (INH) was investigated in young growing rats. The interaction of moderate and severe degree of protein-energy malnutrition (PEM) was also investigated. Hepatic injury was produced by giving 50 mg/kg/day of INH for 2 weeks. Liver showed kupffer cell hyperplasia along with patchy sinusoidal congestion in hematoxylin (H) and eosin (E) staining. However, diffuse microglobules of oil red O′ positive fat globules could be demonstrated in frozen sections stained with oil red O′. The concomitant elevation of serum ALT/AST added support to the histopathologic injury. Electronmicroscopic analysis revealed the proliferation of rough endoplasmic reticulum in INH-treated groups. The glutathione and related thiols were decreased significantly by INH both in blood and liver tissues, indicating a decrease in protective mechanism. Glutathione reductase activity was elevated concomitantly in both the tissues. A significant decrease in the activity of glutathione peroxidase and catalase is again indicative of diminished capacity to handle the disposal of hydrogen peroxide (H₂O₂) and lipid peroxides. All these alterations indicated that the damage to the liver cell could well be operating through the inefficient disposal of superoxides (O⁻₂) and H₂O₂. A profound decrease in the protective mechanism further aggravated the picture in moderate and severe PEM, which was observed with INH alone. © 1997 John Wiley & Sons, Inc.     

Experimental and Computational Comparative Study of the Supercritical Fluid Technology (SFT) and Kneading Method in Preparing β-Cyclodextrin Complexes with Two Essential Oils (Linalool and Carvacrol)

Supercritical fluid technology (SFT) offers many advantages as a potential complexation method compared to the conventional kneading technique. Its applicability to processess in which solvents are not required is a significant benefit. The main aim of this study was to evaluate, experimentally and computationally, the applicability of SFT in the preparation of β-cyclodextrin complexes with two selected essential oils, namely, carvacrol and linalool. Preparation of the complexes was performed using kneading and SFT method. Several methods were used in the solid-state characterization. These include thermal analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, and solid-state nuclear magnetic resonance. Besides, molecular dynamics simulations of all studied systems were conducted in order to have a deeper and a detailed insight, at the atomic level, of the nature of the two used techniques. Despite all the advantages of SFT, better results of guest molecule entrapment inside β-cyclodextrin were obtained with the kneading method. The percentages of oil content for linalool samples were 70 ± 14 and 84 ± 9% for SFT and kneading method, respectively, while the drug content values for carvacrol samples were 67 ± 15 and 81 ± 13% for SFT and kneading method, respectively. Interestingly, simulation results were in perfect agreement with the experimental ones and, moreover, they provided a plausible explanation for the obtained results. In conclusion, our results showed that the SFT was unsuccessful in enhancing the stability of the studied complexes contrary to that of the conventational kneading method, and in both cases, molecular dynamics simulations correctly predicted the expected outcomes.     

Mutant huntingtin causes metabolic imbalance by disruption of hypothalamic neurocircuits

In Huntington's disease (HD), the mutant huntingtin protein is ubiquitously expressed. The disease was considered to be limited to the basal ganglia, but recent studies have suggested a more widespread pathology involving hypothalamic dysfunction. Here we tested the hypothesis that expression of mutant huntingtin in the hypothalamus causes metabolic abnormalities. First, we showed that bacterial artificial chromosome-mediated transgenic HD (BACHD) mice developed impaired glucose metabolism and pronounced insulin and leptin resistance. Selective hypothalamic expression of a short fragment of mutant huntingtin using adeno-associated viral vectors was sufficient to recapitulate these metabolic disturbances. Finally, selective hypothalamic inactivation of the mutant gene prevented the development of the metabolic phenotype in BACHD mice. Our findings establish a causal link between mutant huntingtin expression in the hypothalamus and metabolic dysfunction, and indicate that metabolic parameters are powerful readouts to assess therapies aimed at correcting dysfunction in HD by silencing huntingtin expression in the brain.     

Some measures of reducing leaching loss of nitrates beyond potential rooting zone

Summary Soil nitrate profiles under seven treatments of an experiment on intercropping in row crops were studied at sowing and the after harvesting of different crops. The estimates of NO₃ ^––N in these profiles indicate that intercropping in the row crops grown during the rainy season considerably reduced leaching loss of nitrates. Where the main crop receives the recommended fertilizer amount and the intercrop a small additional application, intercropping greatly reduced the amount of unutilized nitrates and hence their leaching beyong root zone.     

Study of semiconducting nanomaterials under pressure

The pressure induced structural and mechanical properties of nanocrystalline ZnO, ZnS, ZnSe, GaN, CoO, CdSe, CeO(2), SnO(2), SiC, c-BC(2)N, and β-Ga(2)O(3) with different grain sizes have been analyzed under high pressures. The molecular dynamics simulation model has been used to compute isothermal equation of state, volume collapse and bulk modulus of these materials in nano and bulk phases at ambient and high pressures and compared with the experimental data. It is evident from these calculations that the change in particle size affects directly the phase transition pressure and bulk modulus. The values of phase transition pressure and bulk modulus increase with decrease in grain size of the material. The equilibrium cell volume and volume collapse in parent phase is directly proportional to the grain size of the materials. Present results are in good agreement with experimental data. The model is able to explain these thermodynamic properties at varying temperatures and pressures successfully.