The Operculum-Plug Area and Membranous Structure of the Eggs of Trichuris Trichiura

Eggs of Trichuris trichiura were prepared for scanning electron microscopy (SEM) by the dimethylsulfoxide freeze-cracking method. The egg-shell and oocyte were examined by SEM. The egg has a chitinous shell which consists of more than 10 layers of dense lamellae. The shell is bordered by a limiting membrane. An operculum and a collar made of chitinous shell together form the opercular area. The operculum is an empty cavity. The chitinous fibers of the egg-shell in this area are diffuse and loose, with numerous micropores or spaces. The egg-shell in this area therefore appears to form a fine tubular network. The oocyte is an undifferentiated cell with a biconcave drum-like shape. The perivitelline space is conspicuous at both ends of the cell

Determination of ketamine in rabbit plasma by gradient elution liquid chromatography/electrospray mass spectrometry

A sensitive and simple liquid chromatography/electrospray mass spectrometry (LC-ESI-MS) method for determination of ketamine in rabbit plasma using one-step protein precipitation was developed and validated. After addition of methadone as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographically separation was achieved on an SB-C18 (2.1 mm × 50 mm, 3.5 μm) column with methanol-0.1 % formic acid as the mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 237.7 → 219.7 for ketamine and m/z 309.9 → 264.8 for the IS. Calibration plots were linear over the range of 5-1000 ng/mL for ketamine in rabbit plasma. Lower limit of quantification (LLOQ) for ketamine was 5 ng/mL. Mean recovery of ketamine from plasma was in the range of 97.5-100.1 %. RSD of intra-day and inter-day precision were both less than 11 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of ketamine in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of ketamine in rabbit plasma by gradient elution liquid chromatography/electrospray mass spectrometry

A sensitive and simple liquid chromatography/electrospray mass spectrometry (LC-ESI-MS) method for determination of ketamine in rabbit plasma using one-step protein precipitation was developed and validated. After addition of methadone as internal standard (IS), protein precipitation by acetonitrile was used as sample preparation. Chromatographically separation was achieved on an SB-C18 (2.1 mm × 50 mm, 3.5 μm) column with methanol-0.1 % formic acid as the mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used to quantification using target fragment ions m/z 237.7 → 219.7 for ketamine and m/z 309.9 → 264.8 for the IS. Calibration plots were linear over the range of 5-1000 ng/mL for ketamine in rabbit plasma. Lower limit of quantification (LLOQ) for ketamine was 5 ng/mL. Mean recovery of ketamine from plasma was in the range of 97.5-100.1 %. RSD of intra-day and inter-day precision were both less than 11 %. This method is simple and sensitive enough to be used in pharmacokinetic research for determination of ketamine in rabbit plasma.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Dietary calcium requirements of bighead carp (Aristichthys nobilis)

To investigate dietary calcium requirement of bighead carp (Aristichthys nobilis), six purified diets were formulated to contain different concentrations of calcium (0.09% (control), 0.43%, 0.76%, 1.12%, 1.44%, and 1.79% of dry diets). Each diet was hand-fed to triplicate 30 fish with an average initial body weight (3.31 ± 0.09 g) for 60 days. The results showed that weight gain (WG) and specific growth rate (SGR) significantly increased when dietary calcium level was from 0.09% to 0.76% (P < 0.05). The phosphorus and calcium contents of whole fish body were highest in the 0.76% and 1.12% group, respectively (P < 0.05). The serum phosphorus content in the 1.79% group was significantly lower than those in other groups (P < 0.05). As dietary calcium content was from 0.09% to 0.76%, the activities of lipase and proteinase in the intestine had a significant increase (P < 0.05), while the glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities were significantly decreased (P < 0.05). Based on quadratic curve model analysis with WG and WGR as the appraising criteria, the appropriate dietary requirement of calcium for the bighead carp larvae (3.31 ± 0.09 g) was 1.01% - 1.02%