Replication timing properties of the human HPRT locus on active, inactive and reactivated X chromosomes.

X chromosome inactivation is associated with a highly asynchronous pattern of DNA replication at most X-linked loci in females. We studied the human HPRT locus, which is subject to X inactivation and expressed from only the active homolog, with the goal of comparing replication properties between the active and inactive homologs in this region using a fluorescence in situ hybridization approach. We found that in normal female lymphoblasts this locus is replicated in a highly asynchronous manner across a broad, discrete 500-600 kb zone with earliest replication appearing at the gene coding sequence.

Physico-chemical profile of ammi majus.

whole part and mother tincture of Ammi majus were chemically analyzed for setting the standards in Homoeopathic system of medicine. Extractive value, Ash value, TLC UV study and the absorbance spectra in the range of 200-500 nm can be taken as parameters to fix standards.

Large domains of apparent delayed replication timing associated with triplet repeat expansion at FRAXA and FRAXE.

Trinucleotide repeat expansions have been implicated in the causation of a number of neurodegenerative disorders. In the case of fragile X syndrome, full expansion of the FMR1 repeat element (CGG)n has also been correlated with replication timing delay of the locus and proximal flanking sequences in male lymphoblasts. To define more extensively this altered region of DNA replication, as well as to extend these studies to female cells containing premutant and mutant alleles, study of the replication timing properties of a >2-Mb zone in the FRAXA region (Xq27.

Diazepam modulates the period of locomotor rhythm in mice (Mus booduga) and attenuates light-induced phase advances.

Experiments were carried out on the continuous action of diazepam (benzodiazepine) offered through drinking water in 2% ethanol on psi and tau of the activity rhythms under LD (12:12) and DD conditions. Under entraining conditions diazepam failed to evoke striking changes in psi. On the other hand, under free-running conditions period-lengthening and period-shortening effects were observed.

Utilization of peptide carrier system to improve intestinal absorption: targeting prolidase as a prodrug-converting enzyme.

The feasibility of targeting prolidase as a peptide prodrug-converting enzyme has been examined. The enzymatic hydrolysis by prolidase of substrates for the peptide transporter L-alpha-methyldopa-pro and several dipeptide analogues without an N-terminal alpha-amino group (phenylpropionylproline, phenylacetylproline, N-benzoylproline, and N-acetylproline) was investigated. The Michaelis-Menten parameters Km and Vmax for L-alpha-methyldopa-pro are 0.

Rapid mapping of Escherichia coli::Tn5 insertion mutations by REP-Tn5 PCR.

We describe a novel method to map chromosomal Escherichia coli::Tn5 insertion mutations rapidly. This method utilizes the ends of Tn5 and the E. coli REP sequence as primer binding sites for the polymerase chain reaction (PCR).

Structural requirements for the intestinal mucosal-cell peptide transporter: the need for N-terminal alpha-amino group.

The requirement for a free alpha-amino group for the intestinal peptide carrier-mediated transport was investigated. A series of dipeptide analogues without the N-terminal alpha-amino group [including phenylpropionylproline, phenylacetylproline, N-benzoylproline, phenylacetyl-alpha-methyldopa, and hippuric acid (N-benzoylglycine)] were studied in the perfused rat intestinal segment. The absorption of phenylpropionylproline, phenylacetyl-alpha-methyldopa, and N-benzoylproline was concentration dependent.

Seasonality in the flight activity of the tropical bat Rhinopoma hardwickei under natural photoperiod.

The activity cycle of a colony of about 1500 bats Rhinopoma hardwickei was studied in 1978-1979 in Madurai, India. Variations in the times of emergence of foraging paralleled variations in sunset and return to the roosting paralleled sunrise. The releasing stimulus for departure of the first outflyer on clear evenings is the crossing of a lower threshold value of its relative decrease.

Theoretical account of the 'spine of hydration' in the minor groove of duplex d(CGCGAATTCGCG).

The hydration of B-form DNA involves a novel sequence of ordered water molecules in the minor groove known as the spine of hydration. The positions of the ordered waters in the AATT region have been determined and indicate water bridges between the A-N3 and T-O2 acceptor sites. Theoretical calculation on hydration based on Monte Carlo simulation show that the water bridges are more sensitive to the prescription for intermolecular potentials than the choice of canonical vs.

A Monte Carlo simulation study of the aqueous hydration of r(GpC)2: comparison with crystallographic ordered water sites.

Monte Carlo computer simulation is described for the dinucleotide duplex rGpC together with 562 water molecules at an environmental density of 1 g/cc in a cubic cell under periodic boundary conditions. Water-water interactions were treated using the TIP4P potential and the solute water interactions by TIP4P spliced with the nonbonded interactions from the AMBER 3.0 force field.

A theoretical study of the aqueous hydration of canonical B d(CGCGAATTCGCG): Monte Carlo simulation and comparison with crystallographic ordered water sites.

Monte Carlo computer simulation is described for the dodecamer d(CGCGAATTCGCG) together with 1777 water molecules at an environmental density of 1 gm/cc in a cubic cell under periodic boundary conditions. Water-water interactions were treated using the TIP4P potential and the solute water interactions by TIP4P spliced with the non-bonded interactions from the AMBER 3.0 force field.

Use of the peptide carrier system to improve the intestinal absorption of L-alpha-methyldopa: carrier kinetics, intestinal permeabilities, and in vitro hydrolysis of dipeptidyl derivatives of L-alpha-methyldopa.

Intestinal permeabilities of five dipeptidyl derivatives of L-alpha-methyldopa (I) were studied by an in situ intestinal perfusion method. The dipeptides displayed a significant increase in their permeabilities compared to L-alpha-methyldopa. The increases ranged from 4 to 20 times.

Fatal hemoptysis in acute bacterial endocarditis.

Massive hemoptysis is a rare complication of bacterial endocarditis. When seen, it is most often due to septic pulmonary emboli with infarction or rupture of a mycotic aneurysm of the pulmonary artery; these conditions are usually associated with endocarditis of the tricuspid valve. We report a case of fatal hemorrhage into the lung from a mycotic aneurysm of the subclavian artery, which eroded into the left upper lobe; this condition arose as a sequela of staphylococcal endocarditis involving the mitral valve.

Theoretical considerations on the "spine of hydration" in the minor groove of d(CGCGAATTCGCG).d(GCGCTTAAGCGC): Monte Carlo computer simulation.

A theoretical description of aqueous hydration in the minor groove of a B-form DNA is presented on the basis of a liquid-state Monte Carlo computer simulation on a system consisting of the oligonucleotide duplex d(CGCGAATTCGCG).d(GCGCTTAAGCGC) in a canonical B-form together with 1777 water molecules contained in a hexagonal prism cell and treated under periodic boundary conditions. The results are analyzed in terms of solvent density distributions.

Enantioselective synthesis of (R)- and (S)-2-methyl-[3,3,2-2H3] alanines.

The synthesis of optically pure (R)- and (S)-2-methyl-[3,3,3-2H3] alanines of biological interest is described. The stereochemistry of the reaction of the lithio derivative of (R)-(-)-2,5-dimethoxy-3-benzyl-3-methyl-3,6-dihydropyrazine with alkyl and deuterated alkyl iodides is discussed. The configuration of the newly formed center of chirality in (R)- and (S)-2-methyl-[3,3,3-2H3] alanines is derived from 1H NMR.