Učinak vrućice uzrokovane endotoksinom bakterije E. coli na farmakokinetiku i doziranje ceftriaksona u ovaca (Ovis aries).

The effect of fever was studied on the pharmacokinetics of ceftriaxone (CTRX) following intravenous administration at the rate of 50 mg/kg b.m. in Chhotanagpuri sheep. Fever was induced by intravenous administration of E. coli serovar O126:B8 lipopolysaccharide, and plasma CTRX concentration was estimated by HPLC. The plasma drug concentration versus time curve best fitted a two compartment open model. The maximum plasma drug concentration was 16.33 per cent lower in febrile sheep (FS) in comparison to normal sheep (NS). In FS, t1/2α was lower, while t1/2β was higher than in NS. Vdarea and P: C ratio was higher in FS, but ClB and AUC did not differ significantly between the two groups. The results of the present study indicate that CTRX has greater distribution in the peripheral compartment during pyrexia. High values of K12/K /K21 ratio also indicated rapid drug distribution in various body fluids and compartments. The suitable dosage regimen of CTRX in FS by the intravenous route was calculated to be 15 mg/kg b.m. at a 5 h interval.Istraživan je učinak vrućice na farmakokinetiku ceftriaksona (CTRX) nakon njegove intravenske primjene u dozi od 50 mg/kg tjelesne mase u ovaca pasmine Chhotanagpuri. Vrućica je bila uzrokovana intravenskom primjenom lipopolisaharida serovara O126:B8 bakterije E. coli. Koncentracija cefriaksona u plazmi bila je određivana visokotlačnom tekućinskom kromatografijom. Koncentracija lijeka u plazmi u odnosu na vremensku krivulju bila je najsličnija modelu dvaju odjeljaka. Najveća koncentracija lijeka bila je 16,33% manja u febrilnih ovaca u odnosu na nefebrilne. U febrilnih je ovaca t1/2α bio manji, a t1/2β veći nego u nefebrilnih. Prividni volumen raspodjele (Vdarea) i omjer P:C bili su veći u febrilnih ovaca dok se ClB (ukupni klirens lijeka iz organizma) i AUC (površina ispod koncentracijske krivulje lijeka u plazmi) nisu značajno razlikovali između dviju skupina. Rezultati ovog istraživanja naznačuju da ceftriakson ima bolju raspodjelu u perifernom odjeljku za vrijeme vrućice. Velike vrijednosti odnosa K12/K21 također upućuju na brzu raspodjelu lijeka u različitim tjelesnim tekućinama i odjeljcima. Izračunato je da je ceftriakson u febrilnih ovaca najbolje davati intravenski u dozi od 15 mg/kg tjelesne mase u razmaku od pet sati

Utjecaj vrućice prouzročene lipopolisaharidom bakterije E. coli na kinetiku ceftriaksona u plazmi crnih bengalskih koza.

The pharmacokinetic profile of ceftriaxone was studied in healthy and febrile Black Bengal goats after its single intramuscular administration at the dose rate of 50 mg/kg body mass. The fever was induced by intravenous administration of E. coli serovar O126:B8 lipopolysaccharide (1 μg/kg, IV) and the plasma drug concentration was analyzed using HPLC. The plasma drug concentration versus time curve best fi tted the two compartment open model. At 1 min the ceftriaxone concentrations in healthy and febrile animals were 40.58 ± 0.94 μg/mL and 32.83 ± 0.92 μg/mL, respectively and the drug could be detected up to 8 h in healthy goats and up to 4 h in febrile goats. The elimination half-life of ceftriaxone in febrile animals (0.95 ± 0.02 h) was lower than healthy animals (2.30 ± 0.19 h). Volume of distribution was higher in febrile animals (0.72 ± 0.01 L/kg) in comparison to healthy animals (0.15 ± 0.07 L/kg). Total body clearances in healthy and febrile animals were 5.08 ± 0.14 and 8.82 ± 0.31 mL/kg/h, respectively, suggesting extensive clearance of the drug in febrile animals. The intramuscular dose of ceftriaxone in febrile animals was calculated as 6 mg/ kg body mass, to be repeated at a 6 h interval. Results of the present study indicated that the drug distribution is altered by fever.Istraživana je farmakokinetika ceftriaksona u zdravih i febrilnih crnih bengalskih koza nakon njegove jednokratne intramuskularne primjene u dozi od 50 mg/kg tjelesne mase. Vrućica je bila prouzročena intravenskom primjenom lipopolisaharida (1 μg/kg) serovara O126:B8 bakterije E. coli. Koncentracija lijeka u plazmi bila je određivana tekućinskom visokotlačnom kromatografijom. Koncentracija lijeka u plazmi u odnosu na vremensku krivulju najviše je odgovarala modelu dvaju otvorenih odjeljaka. Koncentracija ceftriaksona u zdravih životinja nakon minute bila je 40,58 ± 0,94 μg/mL, a u febrilnih 32,83 ± 0,92 μg/mL. Lijek se nakon primjene mogao dokazati do osam sati u zdravih te do 4 sata u febrilnih koza. Poluživot izlučivanja ceftriaksona u febrilnih koza bio je manji (0,95 ± 0,02 h) nego u zdravih (2,30 ± 0,19 h). Obujam raspodjele bio je veći (0,72 ± 0,01 L/kg) u febrilnih u usporedbi sa zdravima (0,15 ± 0,07 L/kg). Ukupan tjelesni klirens u zdravih životinja bio je 5,08 ± 0,14, a u bolesnih 8,82 ± 0,31 mL/kg/h što upućuje na ekstenzivan klirens lijeka u febrilnih životinja. Izračunato je da intramuskularna doza ceftriaksona u febrilnih životinja iznosi 6 mg/kg tjelesne mase svakih 6 sati. Rezultati istraživanja upućuju na zaključak da se raspodjela lijeka mijenja kod vrućice

Quantitative Analysis of Hydrogenated DLC Films by Visible Raman Spectroscopy

The correlations between properties of hydrogenated diamond like carbon films and their Raman spectra have been investigated. The films are prepared by plasma deposition technique, keeping different hydrogen to methane ratio during the growth process. The hydrogen concentration, sp$^3$ content, hardness and optical Tauc gap of the materials have been estimated from a detail analysis of their Raman spectra. We have also measured the same parameters of the films by using other commonly used techniques, like sp$^3$ content in films by x-ray photoelectron spectroscopy, their Tauc gap by ellipsometric measurements and hardness by micro-hardness testing. The reasons for the mismatch between the characteristics of the films, as obtained by Raman measurements and by the above mentioned techniques, have been discussed. We emphasize on the importance of the visible Raman spectroscopy in reliably predicting the above key properties of DLC films.Comment: 19 pages, 8 figure

Analytic formulas for frequency and size dependence of absorption and scattering efficiencies of astronomical polycyclic aromatic hydrocarbons

In a series of two recent papers, the frequency and size distribution dependence of extinction spectra for astronomical silicate and graphite grains was analyzed by us in the context of MRN type interstellar dust models. These grains were taken to be homogeneous spheres following the power law $(a^{-3.5})$ size distribution which is very much in use. The analytic formulas were obtained for the graphite and silicate grains in wavelength range 1000\AA - 22,500\AA and their utility was demonstrated. In this paper of the series, we present analytic formulas for the scattering and absorption spectrum of another important constituent of interstellar dust models, namely, the polycyclic aromatic hydrocarbons (PAHs). Relative contribution of the PAHs to extinction {\it vis a vis} carbonaceous classical grains has been examined.Comment: 19 pages, 4 figures, to appear in JQSRT 201

Alteration in haematological and biochemical parameters of Catla catla exposed to sub-lethal concentration of cypermethrin

A 60-day experiment was carried out to study the effect of sub-lethal concentration of cypermethrin (1/10th of LC50) exposure on haematological and biochemical parameters of the Indian major carp, Catla catla fingerlings. Under exposure, the total erythrocyte count, total leucocyte count, haemoglobin content and haematocrit were decreased. All the studied serum parameters viz. total serum protein, albumin, globulin contents and albumin–globulin ratio were significantly decreased in cypermethrin-exposed fishes. A marked increase was recorded in alanine aminotransferase and aspartate aminotransferase activities in liver, whereas lactate dehydrogenase activity of muscle and acetylcholine esterase activity in brain were inhibited in cypermethrin-exposed fish. The membrane transport enzymes (total adenosine triphosphatase, sodium–potassium adenosine triphosphatase and magnesium adenosine triphosphatase) activities were decreased significantly in the gills of C. catla exposed to sub-lethal concentration of cypermethrin. The present study indicates that sub-lethal exposure of C. catla fingerlings to cypermethrin alters the haematological and biochemical parameters

pH Dependent surface enhanced Raman study of Phe + Ag Complex and DFT calculations for spectral analysis

Surface enhanced Raman spectra of Phenylalanine (Phe) in Ag colloidal solution have been recorded for Phe solutions of different pH. Spectral line-shape analyses of the enhanced modes, at 1005, 1380 and 1582 cm-1, between pH 4.5 and 10.5, have been carried out. The variation of spectral line-width with pH reveals two possible mechanisms in solution: (i) the fluctuation of pH in microscopic volume in an overall uniform pH solution and/or (ii) the motional narrowing caused by the intermolecular ionic interaction. We suggest that different charge states of the reference molecule are responsible for the observed bond softening with decrease in pH. The observed Raman shift and the Raman activity of the vibrational modes with maximum enhancement have been explained by carrying out DFT calculations.Comment: 17 pages, 5 figure

High-throughput screening and whole genome sequencing identifies an antimicrobially active inhibitor of Vibrio cholerae

BACKGROUND: Pathogenic serotypes of Vibrio cholerae cause the life-threatening diarrheal disease cholera. The increasing development of bacterial resistances against the known antibiotics necessitates the search for new antimicrobial compounds and targets for this pathogen. RESULTS: A high-throughput screening assay with a Vibrio cholerae reporter strain constitutively expressing green fluorescent protein (GFP) was developed and applied in the investigation of the growth inhibitory effect of approximately 28,300 structurally diverse natural compounds and synthetic small molecules. Several compounds with activities in the low micromolar concentration range were identified. The most active structure, designated vz0825, displayed a minimal inhibitory concentration (MIC) of 1.6 μM and a minimal bactericidal concentration (MBC) of 3.2 μM against several strains of V. cholerae and was specific for this pathogen. Mutants with reduced sensitivity against vz0825 were generated and whole genome sequencing of 15 pooled mutants was carried out. Comparison with the genome of the wild type strain identified the gene VC_A0531 (GenBank: AE003853.1) as the major site of single nucleotide polymorphisms in the resistant mutants. VC_A0531 is located on the small chromosome of V. cholerae and encodes the osmosensitive K(+)-channel sensor histidine kinase (KdpD). Nucleotide exchange of the major mutation site in the wild type strain confirmed the sensitive phenotype. CONCLUSION: The reporter strain MO10 pG13 was successfully used for the identification of new antibacterial compounds against V. cholerae. Generation of resistant mutants and whole genome sequencing was carried out to identify the histidine kinase KdpD as a novel antimicrobial target

Long-term adoption of bed planted conservation agriculture based maize/cotton-wheat system enhances soil organic carbon stabilization within aggregates in the indo-gangetic plains

Sustainability of contemporary crop establishment and management practices is questioned due to soil degradation, higher carbon emission and declining soil productivity. Hence, this study was conducted to address the impacts of conservation agriculture (CA) practices like permanent broad beds (PBB), permanent narrow beds (PNB) and zero tilled flat beds (ZT) with residue retention on soil organic carbon (SOC) protection within aggregates in the Indo-Gangetic Plains (IGP). Compared to conventionally tilled (CT) plots, the total SOC content was ∼27%–33% higher in the CA plots on equivalent mass basis. The soil physical properties, such as soil aggregation and mean weight diameter were considerably improved under the CA practices. The macroaggregates were ∼41, 37% and 27% higher in the PBB with residue (PBB + R), PNB with residue (PNB + R) and ZT with residue (ZT + R) plots (CA plots), respectively, than the CT plots in the surface soil (0–15 cm). The plots under PBB + R had ∼31% higher microaggregates within macroaggregates than the CT plots (24.4 g 100 g−1) soil. An increase in SOC content by ∼72, 55% and 69% was observed in the PBB + R, PNB + R and ZT + R plots over the CT plots in microaggregates within macroaggregates (3.02 Mg ha−1). However, plots under PBB + R, PNB + R and ZT + R had only ∼11, 3% and 23% more SOC within silt + clay fraction, respectively, than CT plots (5.85 Mg ha−1). Thus, SOC stabilization within microaggregates inside macroaggregates was the major mechanism, and not the chemical stabilization within silt + clay, of C sequestration under CA. As aggregate-associated carbon is an ecosystem property that strongly affects organic carbon stabilization, water holding capacity and resistance to erosion, growing maize/cotton–wheat system under PBB + R practice is a viable option for carbon sequestration in the IGP and similar agro-ecologies