Comparative pharmacokinetics of theophylline in camels (Camelus dromedarius) and goats (Caprus hircus)

A comparative randomized crossover study was conducted to determine the pharmacokinetics of theophylline in male and female camels (Camelus dromedarius) and goats (Caprus hircus). Theophylline is an established 'probe drug' to evaluate the drug metabolizing enzyme activity of animals. It was administered by the intravenous (i.v.) route and then intramuscularly (i.m.) at a dose of 2 mg/kg. The concentration of the drug in plasma was measured using a high-performance liquid chromatography (HPLC) technique on samples collected at frequent intervals after administration. Following i.v. injection, the overall elimination rate constant (lambda z,) in goats was 0.006 +/- 0.00076/min and in camels was 0.0046 +/- 0.0008/min (P < 0.01). The elimination half-life (t 1/2 lambda z) in goats (112 .7 min) was lower than in camels (154.7 min) (P < 0.01). The apparent volume of distribution (Vz) and the total body clearance (Cl) in goats were 1440.1 +/- 166.6 ml/kg and 8.9 +/- 1.4 ml/min/kg, respectively. The corresponding values in camels were 1720.3 +/- 345.3 ml/kg and 6.1 +/- 1.0 ml/min/kg, respectively. After i.m. administration, theophylline reached a peak plasma concentration (Cmax) of 1.8 +/- 0.1 and 1.7 +/- 0.2 microg/ml at a post-injection time (Tmax) of 67.5 +/- 8.6 and 122.3 +/- 6.7 min in goats and camels, respectively. The mean bioavailability (T) in both goats and camels was 0.9 +/- 0.2. The above data suggest that camels eliminate theophylline at a slower rate than goats.     

Effects of L-asparaginase on plasma amino acid profiles and tumor burden in cats with lymphoma

BACKGROUND: L-Asparaginase (Elspar(a)), is an Escherichia coli-derived enzyme that depletes lymphoma cells of asparagine, inhibiting protein synthesis and resulting in cell death. The single agent response rate in cats with lymphoma and impact of L-asparaginase on plasma amino acid concentrations is unknown. HYPOTHESES: L-Asparaginase significantly reduces plasma asparagine concentrations and has demonstrable efficacy against untreated lymphoma in cats. ANIMALS: Thirteen cats with confirmed lymphoma (LSA) of any anatomic site were given 1 dose 400 IU/kg IM) of L-asparaginase for initial LSA treatment. METHODS: Plasma collected at 0, 2, and 7 days after L-asparaginase therapy was assayed for ammonia, asparagine, aspartic acid, glutamine, and glutamic acid concentrations. Cats were restaged 7 days later to assess tumor response. Results: Eight cats had T-cell LSA, 4 cats had B-cell LSA, and 1 cat's immunophenotype was unknown. Two complete and 2 partial responses to L-asparaginase were seen. Four cats had stable disease, and 5 cats had progressive disease. Ammonia and aspartic acid concentrations were increased from baseline at 2 and 7 days posttreatment. Asparagine concentrations were decreased from baseline at 2 days but not 7 days posttreatment. Glutamic acid concentrations were increased at day 2 compared to day 7 posttreatment but not compared to baseline. Glutamine concentrations were unchanged. CONCLUSIONS AND CLINICAL IMPORTANCE: L-asparaginase significantly reduced asparagine concentrations within 2 days of treatment, but this effect was lost within 7 days. The apparent overall response rate of feline LSA to L-asparaginase in this study was 30%.     

The 1987 whittier narrows earthquake in the los angeles metropolitan area, california

The Whittier Narrows earthquake sequence (local magnitude, M(L) = 5.9), which caused over $358-million damage, indicates that assessments of earthquake hazards in the Los Angeles metropolitan area may be underestimated. The sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is the acceleration of gravity at sea level) within 50 kilometers of the epicenter. The distribution of the modified Mercalli intensity VII reflects a broad north-south elongated zone of damage that is approximately centered on the main shock epicenter.     

Regeneration of ammonia borane spent fuel by direct reaction with hydrazine and liquid ammonia

Ammonia borane (H(3)N-BH(3), AB) is a lightweight material containing a high density of hydrogen (H(2)) that can be readily liberated for use in fuel cell-powered applications. However, in the absence of a straightforward, efficient method for regenerating AB from dehydrogenated polymeric spent fuel, its full potential as a viable H(2) storage material will not be realized. We demonstrate that the spent fuel type derived from the removal of greater than two equivalents of H(2) per molecule of AB (i.e., polyborazylene, PB) can be converted back to AB nearly quantitatively by 24-hour treatment with hydrazine (N(2)H(4)) in liquid ammonia (NH(3)) at 40°C in a sealed pressure vessel.     

Carbon nanotube flow sensors

We report that the flow of a liquid on single-walled carbon nanotube bundles induces a voltage in the sample along the direction of the flow. The voltage that was produced fit a logarithmic velocity dependence over nearly six decades of velocity. The magnitude of the voltage depended sensitively on the ionic conductivity and on the polar nature of the liquid. Our measurements suggest that the dominant mechanism responsible for this highly nonlinear response involves a direct forcing of the free charge carriers in the nanotubes by the fluctuating Coulombic field of the liquid flowing past the nanotubes. We propose an explanation based on pulsating asymmetric ratchets. Our work highlights the device potential for nanotubes as sensitive flow sensors and for energy conversion.     

High dietary protein combats the stress of Labeo rohita fingerlings exposed to heat shock

The amelioration effect of high dietary protein against stress was evaluated in Labeo rohita fingerlings, exposed to heat shock. Two hundred and forty fingerlings (6.57 ± 0.04 g, average weight ± SE) were randomly distributed into 4 treatment groups, each with 4 replicates was fed with either of four diets containing different levels of protein (20, 30, 40 or 45%). Water temperatures of all the treatments were within the range of 25.5–26.5°C throughout the experimental period of 30 days. After 30 days of feeding, fish were given heat shock by exposing to 38°C for 2 h. Heat shock significantly decreased (P < 0.05) liver glycogen content in treatment groups fed with 20 and 30% dietary protein, whereas unaffected in the 40 and 45% protein-fed groups. Heat shock significantly increased (P < 0.05) serum glucose and cortisol level in all the treatments. The 40 and 45% dietary protein–fed groups registered significantly higher survival (%) after the heat shock compared with their lower-protein counterparts. Heat shock increased the glycolytic, gluconeogenic, protein metabolic and antioxidative enzymes to cope up with thermal stress. Our results indicate that high-protein diet (≥40%) combats the stress due to heat shock in Labeo rohita.     

Est1p as a cell cycle-regulated activator of telomere-bound telomerase

In Saccharomyces cerevisiae, the telomerase components Est2p, TLC1 RNA, Est1p, and Est3p are thought to form a complex that acts late during chromosome replication (S phase) upon recruitment by Cdc13p, a telomeric DNA binding protein. Consistent with this model, we show that Est1p, Est2p, and Cdc13p are telomere-associated at this time. However, Est2p, but not Est1p, also binds telomeres before late S phase. The cdc13-2 allele has been proposed to be defective in recruitment, yet Est1p and Est2p telomere association persists in cdc13-2 cells. These findings suggest a model in which Est1p binds telomeres late in S phase and interacts with Cdc13p to convert inactive, telomere-bound Est2p to an active form.     

Reproductive isolation of two tortricid moth species by different ratios of a two-component sex attractant

Two tortricid mitoth species, Adoxophyes orana and Clepsis spectrana, utilize the samne two isomers, cis-9- and cis-l1-tetradecenyl acetate, as their sex attractant. Commnlunication between the sexes of each species is separated effectively by a different blendinig of both compounds by the females and a different response to these blends by the males.