Pharmacokinetics of paeoniflorin after oral administration of Shao-yao Gan-chao Tang in mice.
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Paeoniflorin, a monoterpene glycoside, is the principal bioactive component of Paeoniae Radix. The traditional prescription Shao-yao Gan-chao Tang (SGT; Kampo: Shakuyaku-Kanzo-To), which is composed of Paeoniae Radix and Glycyrrhizae Radix, has been widely used in China and Japan. Quantification of paeoniflorin in mouse plasma after oral administration of SGT (at a dose containing 10 mg/kg paeoniflorin) was achieved using a simple and rapid high-performance liquid chromatography method. The plasma concentration-time curves were fitted with mean terminal half-lives (t 1/2) of 116.17 min. The maximum plasma concentration (Cmax) of paeoniflorin was 111.56 ng/ml, time to reach maximum concentration (tmax) was 17.00 min, the area under the plasma concentration-time curve (AUC)0-t was 12293.42 ng x min/ml, clearance/bioavailability (CL/F) value was 644.74 ml/min x kg, apparent volume of distribution/ bioavailability (Vd/F) value was 103.05 l/kg, and the mean residence time (MRT) was 169.64 min. These results, together with the previously reported kinetic data of paeoniflorin after oral administration of Paeoniae Radix extract alone, indicated that absorption of paeoniflorin after oral administration of SGT was significantly greater than that after oral administration of Paeoniae Radix alone. (+info)
Covalent cross-linking of proteins without chemical reagents.
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A facile method for the formation of zero-length covalent cross-links between protein molecules in the lyophilized state without the use of chemical reagents has been developed. The cross-linking process is performed by simply sealing lyophilized protein under vacuum in a glass vessel and heating at 85 degrees C for 24 h. Under these conditions, approximately one-third of the total protein present becomes cross-linked, and dimer is the major product. Chemical and mass spectroscopic evidence obtained shows that zero-length cross-links are formed as a result of the condensation of interacting ammonium and carboxylate groups to form amide bonds between adjacent molecules. For the protein examined in the most detail, RNase A, the cross-linked dimer has only one amide cross-link and retains the enzymatic activity of the monomer. The in vacuo cross-linking procedure appears to be general in its applicability because five different proteins tested gave substantial cross-linking, and co-lyophilization of lysozyme and RNase A also gave a heterogeneous covalently cross-linked dimer. (+info)
Trachoma in the Sudan. A laboratory study.
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Out of 46 patients in the Sudan who had been diagnosed clinically as having trachoma 25 strains of the trachoma agent were isolated. Bacterial contamination was easily controlled by streptomycin and vancomycin. On repeated passaging, chick embryos lost their susceptibility to the trachoma agent during the summer. (+info)
Characterization of physical state of mannitol after freeze-drying: effect of acetylsalicylic acid as a second crystalline cosolute.
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Freeze-drying of mixed solutes is a preparative technique widely used in the pharmaceutical industry. The presence of an amorphous form or changes in the crystalline form can affect solid state stability. In this work, acetylsalicylic acid (AAS) was chosen as a model drug, and was mixed with mannitol, a commonly used bulking agent in formulation of tablets. Variations in the final freeze-dried crystalline forms were found after changing the ratios of the two co-solutes. Samples were analysed by powder X-ray diffractometry and differential scanning calorimetry. A major amorphous form and a minor crystalline delta-mannitol form were produced during the mannitol freeze-drying process. The crystal form of mannitol in the two-component system depended on the AAS:mannitol ratio. The AAS was mostly crystalline, regardless of the amount of mannitol present. A major delta-mannitol and a minor amorphous form were obtained when AAS was present in a high percentage (75% w/w). When AAS percentages of 50 and 25% (w/w) were present during the drying process, the mannitol was found in a highly crystalline form. (+info)
Effect of water on the molecular mobility of sucrose and poly(vinylpyrrolidone) in a colyophilized formulation as measured by (13)C-NMR relaxation time.
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Individual molecular mobility of sucrose and poly(vinylpyrrolidone) (PVP) in a colyophilized mixture of 1 : 1 by weight has been determined by (13)C spin-lattice relaxation times in the laboratory frame (T(1)) and in the rotating frame (T(1 rho)) for systems containing absorbed water at various levels. The T(1) of the PVP pyrrolidone ring carbon increased with storage relative humidity (RH) in lyophilized PVP alone, indicating that the MHz-order motions of PVP side chain increased with storage RH. However, in the colyophilized mixture, the side chain motions of PVP did not change with storage RH, and showed similar mobility to sucrose. This may be caused by hydrogen bonding between the PVP ring carbonyl group and hydroxyl group of sucrose, as suggested by a previous FT-Raman study. The mid-kHz-order motions of sucrose in the sucrose-PVP mixture as determined by T(1 rho) did not increase with storage RH as much as in lyophilized sucrose alone. This suggests that the molecular mobility of sucrose decreases in the presence of PVP due to hydrogen bonding between the hydroxyl group of sucrose and the carbonyl group of PVP. Inhibition of sucrose crystallization by PVP in the presence of water appears to be linked to the effect of PVP on the molecular mobility of sucrose. (+info)
The fungal sheath of ectomycorrhizal pine roots: an apoplastic barrier for the entry of calcium, magnesium, and potassium into the root cortex?
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The apoplastic permeability of the fungal sheath of two different ectomycorrhizal associations of Pinus sylvestris L. was analysed by laser microprobe mass analysis (LAMMA) and energy-dispersive X-ray spectroscopy (EDXS) after stable isotope labelling with 25Mg, 41K and 44Ca. Entry of 25Mg and 44Ca into the outer cortical apoplast of non-mycorrhizal roots was detected after 4 min of labelling. After a longer exposure time the endodermis with its Casparian band acted as an efficient apoplastic diffusion barrier for the radial movement of 25Mg and 44Ca into the stele. A fraction of approximately one-third of the apoplastic cations of the root cortex could not be exchanged against the external label even after longer exposure times. The ectomycorrhizal sheath of the two fungal species used, Pisolithus tinctorius (Pers.) Coker & Couch and Suillus bovinus (L. ex Fr.) Kuntze, does not completely inhibit the apoplastic movement of ions into the mycorrhizal root cortex, but retarded the penetration of isotopes into the cortical apoplast. In roots inoculated with S. bovinus, a clear labelling of the cortical apoplast could first be detected after 24 h of exposure to the stable isotope solution. At this time the labelling of the cortical apoplast in these mycorrhizal roots was higher than those of non-mycorrhizal roots and, with EDXS, changes in the element composition of the apoplast were detected. The results indicated that possibly hydrophobins localized in the fungal cell wall might be involved in the increased hydrophobicity of mycorrhizal roots and the lower permeability of the ectomycorrhizal sheath. (+info)
Lyophilized apple counteracts the development of hypercholesterolemia, oxidative stress, and renal dysfunction in obese Zucker rats.
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Apples may have selective effects on abnormalities associated with the plurimetabolic syndrome. Therefore, the effects of 20% lyophilized apple supplementation on plasma and tissue lipids and on protection against susceptibility to oxidative stress and renal dysfunction were investigated in Zucker lean (Fa/-) or obese (fa/fa) rats. The experimental diets were equilibrated for sugar supply, contained 0.25 g/100 g cholesterol and provided only one third of the vitamin E requirement. Obese Zucker rats were hypercholesterolemic with cholesterol accumulation in LDL and HDL fractions. The apple diet lowered plasma and LDL cholesterol (-22 and -70%, respectively, P < 0.01) in obese Zucker rats and, in parallel, reduced triglyceride accumulation in heart and liver. Zucker rats fed the apple diet also had a larger intestinal pool and greater fecal excretion of bile acids. The heart concentration and urinary excretion of malondialdehyde were reduced by apple consumption in obese Zucker rats, suggesting better protection against peroxidation. Glucosuria and proteinuria in obese Zucker rats were also suppressed by the apple diet. In conclusion, despite their moderate fiber content, apples improve substantially the lipid status and peroxidative parameters in obese Zucker rats, suggesting that other plant constituents such as polyphenols are involved in these effects. (+info)
Bovine blastocyst development from oocytes injected with freeze-dried spermatozoa.
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Pronuclear formation, and the chromosomal constitution and developmental capacity of bovine zygotes formed by intracytoplasmic sperm injection with freeze-dried (lyophilized) spermatozoa were evaluated. Frozen-thawed spermatozoa were selected, freeze-dried, and stored at 4 degrees C until use. After 22-24 h of in vitro maturation oocytes were denuded and injected singly with a lyophilized spermatozoon. Injected oocytes were activated by treatment with 10 microM ionomycin (5 min) alone and in combination with 1.9 mM 6-dimethylaminopurine (DMAP) for 4 h. Ionomycin plus DMAP activation treatment resulted in a significantly higher proportion of sperm-injected oocytes with two pronuclei than was found after activation with ionomycin alone (74% vs. 56%; P < 0.03). The rates of cleavage, morula, and blastocyst development of sperm-injected oocytes treated with ionomycin plus DMAP were higher than after activation with ionomycin alone (63.3%, 34.2%, and 29.6% vs. 44.7%, 18.7%, and 10.6%, respectively; P < 0.05). Seventy-three percent of blastocysts produced with lyophilized sperm were diploid. These results demonstrate that in vitro-matured bovine oocytes can be fertilized with freeze-dried sperm cells, and that resultant zygotes can develop into karyotypically normal blastocysts. (+info)