Micropropagation of Dendrocalamus asper by shoot proliferation using seeds

An efficient and reproducible procedure for the large-scale propagation of Dendrocalamus asper is described. High-frequency direct shoot proliferation was induced in aseptic seed cultures of D. asper on modified Murashige and Skoog's (1962) medium supplemented with 1.0–10.0 mg/l benzyladenine (BA). Multiple shoots (1–25) were formed within 5 weeks of seed culture without root formation. The shoot-forming capacity of seeds was influenced by the BA concentration in the medium. Proliferating shoot cultures were established by repeatedly subculturing shoots in propagules of 3 shoots each. A multiplication rate of 15–16 fold was achieved on MS medium +3.0 mg/l BA. Roots were formed on excised propagules of 3–5 shoots when transferred to MS medium containing 10.0 mg/l indole-3-butyric acid (IBA) or 3.0 mg/l 1-naphthaleneacetic acid (NAA). Plantlets were hardened, acclimatized and established in soil, where they exhibited normal growth. Received: 10 April 1998 / Revision received: 18 November 1998 / Accepted: 12 December 1998     

Sesamol alleviates diet-induced cardiometabolic syndrome in rats via up-regulating PPARγ, PPARα and e-NOS

Increased oxidative stress and inflammation in obesity are the central and causal components in the pathogenesis and progression of cardiometabolic syndrome (CMetS). The aim of the study was to determine the potential role of sesamol (a natural powerful antioxidant and anti-inflammatory phenol derivative of sesame oil) in chronic high-cholesterol/high-fat diet (HFD)–induced CMetS in rats and to explore the molecular mechanism driving this activity. Rats were fed with HFD (55% calorie from fat and 2% cholesterol) for 60 days to induce obesity, dyslipidemia, insulin resistance (IR), hepatic steatosis and hypertension. On the 30th day, rats with total cholesterol >150 mg/dl were considered hypercholesterolemic and administered sesamol 2, 4 and 8 mg/kg per day for the next 30 days. Sesamol treatment decreased IR, hyperinsulinemia, hyperglycemia, dyslipidemia, TNF-α, IL-6, leptin, resistin, highly sensitive C-reactive protein (hs-CRP), hepatic transaminases and alkaline phosphatase, along with normalization of adiponectin, nitric oxide and arterial pressures in a dose-dependent fashion. Increased TBARS, nitrotyrosine and decreased antioxidant enzyme activities were also amended in HFD rats. Similarly, sesamol normalized hepatic steatosis and ultrastructural pathological alteration in hepatocytes, although the effect was more pronounced at 8 mg/kg. Furthermore, hepatic PPARγ, PPARα and e-NOS protein expressions were increased, whereas LXRα, SERBP-1c, P-JNK and NF-κB expression were decreased by sesamol treatment. These results suggest that sesamol attenuates oxidative stress, inflammation, IR, hepatic steatosis and hypertension in HFD-fed rats via modulating PPARγ, NF-κB, P-JNK, PPARα, LXRα, SREBP-1c and e-NOS protein expressions, thereby preventing CMetS. Thus, the present study demonstrates the therapeutic potential of sesamol in alleviating CMetS.     

Flexible histone tails in a new mesoscopic oligonucleosome model

We describe a new mesoscopic model of oligonucleosomes that incorporates flexible histone tails. The nucleosome cores are modeled using the discrete surface-charge optimization model, which treats the nucleosome as an electrostatic surface represented by hundreds of point charges; the linker DNAs are treated using a discrete elastic chain model; and the histone tails are modeled using a bead/chain hydrodynamic approach as chains of connected beads where each bead represents five protein residues. Appropriate charges and force fields are assigned to each histone chain so as to reproduce the electrostatic potential, structure, and dynamics of the corresponding atomistic histone tails at different salt conditions. The dynamics of resulting oligonucleosomes at different sizes and varying salt concentrations are simulated by Brownian dynamics with complete hydrodynamic interactions. The analyses demonstrate that the new mesoscopic model reproduces experimental results better than its predecessors, which modeled histone tails as rigid entities. In particular, our model with flexible histone tails: correctly accounts for salt-dependent conformational changes in the histone tails; yields the experimentally obtained values of histone-tail mediated core/core attraction energies; and considers the partial shielding of electrostatic repulsion between DNA linkers as a result of the spatial distribution of histone tails. These effects are crucial for regulating chromatin structure but are absent or improperly treated in models with rigid histone tails. The development of this model of oligonucleosomes thus opens new avenues for studying the role of histone tails and their variants in mediating gene expression through modulation of chromatin structure.     

A phase dynamic model of systematic error in simple copying tasks

A crucial insight into handwriting dynamics is embodied in the idea that stable, robust handwriting movements correspond to attractors of an oscillatory dynamical system. We present a phase dynamic model of visuomotor performance involved in copying simple oriented lines. Our studies on human performance in copying oriented lines revealed a systematic error pattern in orientation of drawn lines, i.e., lines at certain orientation are drawn more accurately than at other values. Furthermore, human subjects exhibit “flips” in direction at certain characteristic orientations. It is argued that this flipping behavior has its roots in the fact that copying process is inherently ambiguous—a line of given orientation may be drawn in two different (mutually opposite) directions producing the same end result. The systematic error patterns seen in human copying performance is probably a result of the attempt of our visuomotor system to cope with this ambiguity and still be able to produce accurate copying movements. The proposed nonlinear phase-dynamic model explains the experimentally observed copying error pattern and also the flipping behavior with remarkable accuracy.     

Triple recognition of B-DNA

A novel conjugate of Hoechst 33258, pyrene and neomycin was synthesized and examined for its binding and stabilization of A-T rich DNA duplexes using spectroscopic and viscometric techniques. The conjugate, containing three well known ligands that bind nucleic acids albeit in different binding modes, was found to significantly stabilize DNA over parent conjugates containing only one or both of the other recognition elements. The study represents the first example of DNA molecular recognition capable of minor/major groove recognition in conjunction with intercalation.     

Development of EST SSRs in Finger Millet (Eleusine coracana ssp coracana) and their Transferability to Pearl Millet (Pennisetum glaucum)

EST-SSR markers were developed using sequence information from 1740 expressed sequence tags (ESTs) of finger millet available in the public domain. A set of 31 SSR markers were synthesized based on di, tri, tetra and penta-nucleotide repeat sequences. These were used for PCR analysis of 11 elite germplasm lines of finger millet of Indian and African origin. Out of 31 SSR markers, amplification products were obtained for 17 primer pairs. Of these nine were found polymorphic with two alleles per locus. These 17 SSR primer pairs were also tested for amplification in three varieties of pearl millet (Pennisetum glaucum) and 11 could be transferred to pearl millet. The informative EST SSR markers developed, can be used in finger millet as well as pearl millet genetic improvement projects.     

Dataset of potential targets for Mycobacterium tuberculosis H37Rv through comparative genome analysis

Mycobacterium tuberculosis is the causative agent of the disease, tuberculosis and H37Rv is the most studied clinical strain. We use comparative genome analysis of Mycobacterium tuberculosis H37Rv and human for the identification of potential targets dataset. We used DEG (Database of Essential Genes) to identify essential genes in the H37Rv strain. The analysis shows that 628 of the 3989 genes in Mycobacterium tuberculosis H37Rv were found to be essential of which 324 genes lack similarity to the human genome. Subsequently hypothetical proteins were removed through manual curation. This further resulted in a dataset of 135 proteins with essential function and no homology to human.