A rapid and sensitive liquid chromatography/tandem mass spectrometry method for determination of docetaxel in human plasma

A novel, rapid and sensitive isocratic liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for quantification of docetaxel in human plasma with paclitaxel as internal standard. The high sensitivity and specificity of MS/MS detection enabled the use of a small volume of plasma (0.05 mL) and a simple liquid-liquid extraction procedure. Furthermore, a very short run-time (3 min) fulfilled the need for monitoring plasma levels of docetaxel from large-scale clinical studies. The calibration curve for docetaxel was linear over the range 5-1000 ng/mL with coefficients of correlation >0.999 using only 0.05 mL plasma. The intra- and inter-day precisions (CV) of analysis were <7%, and accuracy ranged from 96 to 110%. The applicability of the method was demonstrated in a pharmacokinetic study of a 1-h infusion of docetaxel with dosages of 75 mg/m(2). Possible conjugated metabolites of docetaxel were not detected in patients' samples.

Purification of salmon thrombin and its potential as an alternative to mammalian thrombins in fibrin sealants

A method to produce highly purified thrombin from salmon blood is described, and a series of biochemical, cell biologic, and biophysical assays demonstrate the functional similarities and some differences between salmon and human thrombins. Salmon thrombin with specific activity greater than 1000 units/mg total protein can be prepared by modifications of the methods used for purification of human thrombin. Using a synthetic substrate based on the human fibrinogen A-alpha polypeptide sequence as an indicator of enzymatic activity, salmon and human thrombin preparations contain similar specific activities per mass of purified protein. Salmon thrombin activates human fibrinogen and initiates the formation of fibrin clots whose structure and rheologic properties are indistinguishable from those of human fibrin clotted by human thrombin. Salmon thrombin also activates human platelets. Approximately 10 times higher activities are needed for the same rate of platelet aggregation compared to human thrombin, and some aspects of platelet activation, most notably phosphatidylserine exposure, are diminished relative to the effects of human thrombin. This latter finding suggests that salmon thrombin may not activate all of the receptors that are targets of human thrombin, although it does appear to activate signals that are sufficient to produce normal rates of activation and aggregation as measured by conventional aggregometry. Together with the recent purification of salmon fibrinogen and its application in mammalian wound healing, the availability of salmon thrombin allows the formulation of biological sealants devoid of any exogenous mammalian proteins and so may aid the design of materials with increased safety from infectious disease transmission.

Effect of cetrimide and ascorbic acid on in vitro human skin permeation of haloperidol

Permeation of haloperidol through the human skin in vitro was studied with two enhancers, cetrimide and ascorbic acid, at various concentrations. Amber glass Franz-type diffusion cells were used for the permeation studies and haloperidol was made soluble in aqueous solution with the aid of lactic acid. Donor solutions were prepared by adding excess of haloperidol to 0.03% (v/v) lactic acid solution with or without enhancers at concentrations 0.1, 0.3 and 0.6% (w/v) and stirred for 36 h at 32 degrees C before filtering. Ascorbic acid gradually increased the solubility of the haloperidol from that of the control where as cetrimide did not show any effect. Cetrimide concentration dependent increase in the permeability coefficient of haloperidol was observed. Mechanism of enhancement by cetrimide was probed with the diffusion profile kinetics and Fourier transform infrared (FT-IR) spectroscopy. Cetrimide was found to increase the thermodynamic activity of the drug in the skin. IR spectra of the stratum corneum treated with cetrimide showed time-dependent decrease in the intensity of the spectrum and dose-dependent decrease of lipid band but no change in the protein conformation. Cetrimide appears to interact with both the dermal keratin and lipids and this interaction was found to be irreversible. Ascorbic acid although increased the flux of haloperidol to the same extent at all concentrations from that of the control, decreased the permeability coefficient and enhancer index in a concentration dependent manner and this is due to the increased solubility of the drug in the vehicle. Both the enhancers did not change the lag time from that of the control.

Verapamil, cyproheptadine, and anisodamine antagonized [Ca2+]i elevation induced by TNFalpha in a single endothelial cell

AIM

To study the effect of tumor necrosis factor alpha (TNFalpha) on intracellular free Ca2+ concentration ([Ca2+]i) and the effects of verapamil (Ver), cyproheptadine (Cyp), and anisodamine (Ani) on TNFalpha-induced [Ca2+]i changes in single endothelial cell, and to explore the mechanisms of TNFalpha-mediated shock and antishock actions of Cyp and Ani.

METHODS

Human umbilical vein endothelial cell strains (ECV304) were seeded in 35-mm tissue culture dish with 2 mL DMEM culture medium. The cultured cells were loaded by Fluo-3/AM. The spatial distribution and the dynamic changes of [Ca2+]i in single endothelial cell were determined by laser scanning confocal microscopy.

RESULTS

After stimulation with TNFalpha, [Ca2+]i in single endothelial cell rapidly increased in a concentration-dependent manner and arrived at the peak value within 60 s, afterwards, decreased and kept above the basal level. The confocal scanning image showed that [Ca2+]i elevation was more obvious in nuclear than in cytoplasma and decreased slowly. Ver (1, 2 micromol/L), Cyp (30, 60 micromol/L), and Ani (20, 40 micromol/L) markedly inhibited TNFalpha 1.2 nmol/L-induced [Ca2+]i elevation.

CONCLUSION

TNFalpha markedly induces elevation of [Ca2+]i in a single endothelial cell, it may be an important mechanism of TNFalpha-induced shock and tissue injury. That Cyp and Ani obviously suppress TNFalpha-induced [Ca2+]i elevation probably is one of the mechanisms of their antishock effects.

Effect of some enhancers on the permeation of haloperidol through rat skin in vitro

The objective of this work is to enhance the permeation of haloperidol through the rat skin in vitro by using various enhancers at a concentration of 1 mg/ml in the saturated drug solution and analysing the dose-dependent diffusion profile for the enhancers which significantly increased permeation at this concentration compared with the control. Enhancers belonging to various chemical classes like the vitamins (ascorbic acid), surfactants (cetrimide, polysorbate 20), sulfoxides (dimethyl sulfoxide), glycols (polyethylene glycol 400, propylene glycol) and amides (urea) were used. Amber glass Franz-type diffusion cells were used for the permeation studies and haloperidol was made soluble in aqueous solution with the aid of lactic acid. Ascorbic acid and cetrimide increased flux and permeability coefficient significantly. From the dose-dependent permeation studies, it was concluded that ascorbic acid enhanced the permeation by increasing the solubility of the drug in the vehicle thus providing a high concentration gradient across the skin, whereas cetrimide enhanced the permeation by increasing the thermodynamic activity which may be due to solubilization of skin lipids by micelles. Polysorbate 20 decreased the enhancer index by decreasing the thermodynamic activity. None of the enhancers changed the lag time except for urea which decreased the lag time probably by its binding with keratin. Dimethyl sulfoxide, polyethylene glycol 400 and propylene glycol did not have a significant effect on haloperidol permeation compared with control.

Purification of salmon clotting factors and their use as tissue sealants

Fibrin sealant prepared from the blood of farmed Atlantic salmon (Salmo salar) represents a potential source of well-controlled natural material with utility in a variety of clinical settings. A potential advantage of this material is a lower probability of viral or bacterial infection that has limited general approval of fibrin glues made from human or bovine proteins. This report describes the purification of fibrinogen from salmon blood, the use of fibrin glues derived from this material to promote wound healing in rats, and the antigenic response to this material. While the low ambient temperature of these cold water fish significantly lessens the probability of infectious transmission to humans, fibrinogen and factor XIII derived from S. salar are activated by human thrombin at 25 degrees C and 37 degrees C to form clots equivalent to those formed by human fibrin. We compare the reactivity of salmon and human fibrinogen with human and bovine thrombin and the structure and viscoelastic properties of the resulting fibrin gels over a range of pH and salt concentrations. The efficacy of salmon fibrin glues in a wound healing assay and the low antigenic response to salmon fibrinogen suggest that this material may substitute for proteins derived from mammalian sources with lower probability of infections.

[Dynamic changes of serum lipids in patients with acute stroke]

The dynamic changes of the serum levels of total cholesterol(TC), triglyceride(TG), high density lipoprotein-cholesterol(HDL-c) and subfraction(HDL2-c), apolipoprotein(Apo) A-I, ApoB, lipoprotein(a)[Lp(a)] and fibrinogen(Fg) were measured in forty-one patients with acute[including 31 cerebral hemorrhagic patients(ICH), and 10 cerebral infraction patients(CI)]. The results showed that the serum levels of HDL-c and subfractions, ApoA-I and TC gradually decreased in ICH during acute phase, and reduced to the lowest level on the fourteenth day, while the levels of TG and ApoB had no obvious change, the serum levels of Fg and Lp(a) increased to the highest level on the seventh day. The serum levels of Lp(a), ApoB and TG had no obvious change in CI during acute phase, and the serum levels of TC, HDL-c and subfraction, ApoA-I decreased, while the level of Fg increased in CI, but there was no statistical significance. It is suggested that Lp (a) is a positive acute reactive lipoprotein in ICH, and HDL and ApoA-I are negative acute reactive substances in ICH and CI.

Potentiation of temozolomide and topotecan growth inhibition and cytotoxicity by novel poly(adenosine diphosphoribose) polymerase inhibitors in a panel of human tumor cell lines

Potent poly(ADP-ribose) polymerase (PARP) inhibitors have been developed that potentiate the cytotoxicity of ionizing radiation and anticancer drugs. The biological effects of two novel PARP inhibitors, NU1025 (8-hydroxy-2-methylquinazolin-4-[3H]one, Ki = 48 nM) and NU1085 [2-(4-hydroxyphenyl)benzamidazole-4-carboxamide, Ki = 6 nM], in combination with temozolomide (TM) or topotecan (TP) have been studied in 12 human tumor cell lines (lung, colon, ovary, and breast cancer). Cells were treated with increasing concentrations of TM or TP +/- NU1025 (50, 200 microM) or NU1085 (10 microM) for 72 h. The potentiation of growth inhibition by NU1025 and NU1085 varied between the cell lines from 1.5- to 4-fold for TM and 1- to 5-fold for TP and was unaffected by p53 status. Clonogenic assays undertaken in two of the cell lines confirmed that the potentiation of growth inhibition reflected the potentiation of cytotoxicity. NU1025 (50 microM) was about as effective as 10 microM NU1085 at potentiating growth inhibition and cytotoxicity, consistent with the relative potencies of the two molecules as PARP inhibitors. Potentiation of cytotoxicity was obtained at concentrations of NU1025 and NU1085 that were not toxic per se; however, NU1085 alone was 3-fold more cytotoxic (LC50 values ranged from 83 to 94 microM) than NU1025 alone (LC50 > 900 microM). These data demonstrate that PARP inhibitors are effective resistance-modifying agents in human tumor cell lines and have provided a comprehensive assessment protocol for the selection of optimum combinations of anticancer drugs, PARP inhibitors, and cell lines for in vivo studies.

Measurement of the total cross section for hadronic production by e(+)e(-) annihilation at energies between 2.6-5 GeV

Using the upgraded Beijing Spectrometer, we have measured the total cross section for e(+)e(-) annihilation into hadronic final states at center-of-mass energies of 2.6, 3.2, 3.4, 3.55, 4.6, and 5.0 GeV. Values of R, sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->&mgr;(+)&mgr;(-)), are determined.

[The expression of adhesion molecules in human salivary adenoid cystic carcinoma cell line]

OBJECTIVE:The aim of this study was to investigate the expression of the adhesion molecules in human salivary adenoid cystic carcinoma(ACC) cell lines (ACC-2 line and ACC-M strain) which had different metastatic ability.METHODS:The expression of adhesion molecules,which included CD44s,CD44v6,E cadherin,alph-catenin and beta-catenin in two human salivary ACC cell lines and Scid mice neoplasm models was investigated by immunohistochemistry. RESULTS: (1)Positive staining of adhesion molecules in lung metastatic foci of ACC was higher than that in subcutaneous implanted tumor mass.(2)The growing of ACC-M was slower in the cells of abdominal cavity implanted tumor,and also the differentiation of the former was better than the latter.(3)Weaker Positive staining of CD44v6 in ACC cells in vitro was showed,however,no positive staining was detected in lung metastatic foci cells of ACC M and the cells of subcutaneous tumor.CONCLUSION: The expression of CD44s in ACC cells was influenced by cell differentiation,and may affect the growth conditions;The expression levels of E cad/cat was positively correlative to the differentiation of ACC tumor cells;No significant correlation was revealed between the expression of CD44v6 and metastatic ability of ACC.

Attenuation of morphine tolerance and dependence in scopolamine-treated rats

Morphine tolerance and dependence were investigated in scopolamine-treated rats. The results showed that scopolamine treatment (up to 2 mg/kg) did not affect basal line or morphine-induced latency in the tail-flick test but significantly increased the escape latency in the Morris water-maze task. Co-administration of scopolamine could considerably attenuate development of morphine tolerance and naloxone-precipitated withdrawal syndrome. Pretreatment of scopolamine for 7 days prior to morphine administration also significantly reduced the tolerance and withdrawal symptoms. Scopolamine treatment was further shown to attenuate morphine-induced conditioned place preference, an indicator of morphine psychological dependence. The present study demonstrated the attenuation of morphine tolerance and dependence in scopolamine-treated animals, probably related to scopolamine-produced learning and memory impairment.

Inhibition of calcium/calmodulin-dependent protein kinase II in rat hippocampus attenuates morphine tolerance and dependence

Learning and memory have been suggested to be important in the development of opiate addiction. Based on the recent findings that calcium/calmodulin-dependent protein kinase II (CaMKII) is essential in learning and memory processes, and morphine treatment increases CaMKII activity in hippocampus, the present study was undertaken to examine whether inhibition of hippocampal CaMKII prevents morphine tolerance and dependence. Here, we report that inhibition of CaMKII by intrahippocampal dentate gyrus administration of the specific inhibitors KN-62 and KN-93 to rats significantly attenuated the tolerance to the analgesic effect of morphine and the abstinence syndrome precipitated by opiate antagonist naloxone. In contrast, both KN-04 and KN-92, the inactive structural analogs of KN-62 and KN-93, failed to attenuate morphine tolerance and dependence, indicating that the observed effects of KN-62 and KN-93 are mediated through inhibition of CaMKII. Furthermore, administration of CaMKII antisense oligonucleotide into rat hippocampal dentate gyrus, which decreased the expression of CaMKII specifically, also attenuated morphine tolerance and dependence, while the corresponding sense oligonucleotide of CaMKII did not exhibit such inhibitory effect. Moreover, the KN-62 treatment abolished the rewarding properties of morphine as measured by the conditioned place preference. These results suggest that hippocampal CaMKII is critically involved in the development of morphine tolerance and dependence, and inhibition of this kinase may have some therapeutic benefit in the treatment of opiate tolerance and dependence.

Measurement of the spatial coherence of light influenced by turbulence

To evaluate the Earth's surface with a sensor on a satellite, it is important for one to use a correction factor such as atmospheric turbulence. The spatial coherence of light influenced by turbulence was measured in the laboratory by use of a simulator equipped with a multiple reflection system. The turbulence was generated by changing the ambient temperatures from 32 to 48 degrees C. It was found that the spatial coherence of light that passed through the turbulent region decreased when the temperature increased. Double-slit interference fringes were analyzed by a photographic method. The visibility of the interference fringes is the degree of coherence.

Effects of dexamethasone, cyproheptadine, anisodamine, and dinoprostone on TNF alpha production in endotoxic shock

AIM

To study the effects of dexamethasone (Dex), cyproheptadine (Cyp), anisodamine (Ani), and dinoprostone (Din) on lipopolysaccharides (LPS)-induced tumor necrosis factor alpha (TNF alpha) gene expression and antishock effects of inhibiting TNF alpha production.

METHODS

Endotoxic shock in rats was produced by i.v. injection of LPS (E coli O111B4, 5 mg.kg-1). TNF alpha mRNA accumulation was assessed by Northern blot. Plasma TNF alpha contents were determined by radioimmunoassay.

RESULTS

The TNF alpha mRNA levels in rat liver at 2 h after LPS challenge was increased obviously (autoradiograms analyzed by scanning were 38 +/- 10 vs saline control 11 +/- 8, P < 0.01). The plasma TNF alpha contents were markedly increased [(22 +/- 3) micrograms.L-1 vs saline control (2.2 +/- 1.0) micrograms.L-1, P < 0.01]. Dex 5, Cyp 5, Ani 10, or Din 2 mg.kg-1 immediately injected after i.v. LPS markedly decreased the TNF alpha mRNA levels in rat liver and plasma TNF alpha contents. The Dex, Cyp, Ani, and Din improved the mouse survival rate 24 h after LPS 20 mg.kg-1 challenge.

CONCLUSION

Dex, Cyp, Ani, and Din strongly inhibit LPS-induced TNF alpha gene expression, and have a beneficial antishock effects.

[The observation of the acute toxicity of the lanthanum and cerium to the buccal mucosa and systemic conditions of mice]

OBJECTIVE:The present study was to investigate the systemic and local acute toxicity of the lanthanum(La) and cerium(Ce) to the mice. METHODS: 0.2% and 1% La and Ce solutions were applied to buccal mucoa of mice.The systemic conditions and local histopathological changes were observed. RESULTS: The mice hadn't any systemic acute toxic reactions. Histological observation found that mucosal structures of most mice were almost normal,only a few mice showed the slight inflammation,but there were no significant differences between experimental and control groups. CONCLUSION: It was safe for local use of 0.2%,1% La and Ce to the buccal mucosa of mice. La and Ce may become a kind of safe caries-preventive drugs for local application.

[The effect of fluoride on bone extracellular matrix proteins expression in rat calvarial osteoblast in culture]

OBJECTIVE:The expression of various non-collagenous proteins and collagen protein on the rat fetal calvarial osteoblast cultured in low doses fluoride condition in vitro had been studied.METHODS:Our study applied the immunohistochemistry technique to detect the expression of bone sialoprotein, osteocalcin, osteopontin, alkaline phosphatase and type I collagen expressed in the bone matrix.RESULTS:They demonstrated that there were difference in the location and function of the collagenous and non-collagenous proteins in the development of bone matrix.CONCLUSION:The present results revealed that fluoride might enhance the proliferation activity of osteoblast precursors; simultaneously, fluoride might accelerate the phenotypic development of osteoblast and the expression of collagenous and non-collagenous proteins. As a result,low doses fluoride played a favorable role in the development of bone extracellular matrix.

[The influence of fluoride on the development of the osteoblast phenotype in rat calvarial osteoblasts: an in vitro study]

OBJECTIVE:The effects of low doses fluoride on the phenotypic development of rat fetal calvarial osteoblast were studied because the cellular mechanism of fluoride promotes the increasing of bone volume clinically is unclear. METHODS:The influence of fluoride on the rat first passage osteoblast were valuated by histochemistry, enzyme-histochemistry and electron microanalysis in vitro.RESULTS:The study had revealed that not only the bone tubular and the degree of mineralization, but also the activity expression of alkaline phosphatase of osteoblasts in fluoride group were better than the control group. CONCLUSION:The results suggested that low doses fluoride might not only increase the proliferation and differentiation of osteoblast precursors as well as the production and activity of alkaline phosphatase; but also favored the mineralized formation of osteoblast nodules.

Effects of recombinant human endothelial-derived interleukin-8 on hemorrhagic shock in rats

AIM

To study the effects of recombinant human endothelial-derived interleukin-8 (IL-8) on hemorrhagic shock.

METHODS

A profound hemorrhagic shock in rats was produced by exsanguination from femoral artery with mean arterial blood pressure (MABP) maintained at 5.32 kPa for 90 min. After transfusion, IL-8 250 micrograms.kg-1 was i.v. injected. Plasma endothelin-1 (ET-1) and 6 ketoprostaglandin F1 alpha (6-KPGF1 alpha) contents were determined with radioimmunoassay.

RESULTS

After i.v. IL-8, the MABP in IL-8 group was elevated obviously (P < 0.01), the rat survival 2 h after infusion was increased (P < 0.05). During profound shock the plasma ET-1 levels were higher (21 +/- 4 vs 8.2 +/- 1.8 ng.L-1, P < 0.01) and the plasma 6-KPGF1 alpha contents lower than those in normal rats (107 +/- 12 vs 157 +/- 11 ng.L-1, P < 0.01). IL-8 remarkably reduced the plasma ET-1 levels (10 +/- 4 ng.L-1, P < 0.01) and enhanced plasma 6-KPGF1 alpha contents (368 +/- 16 ng.L-1, P < 0.01).

CONCLUSION

IL-8 has beneficial antishock effects.

[The effects of LTA and plaque on the periodontal tissue of the Guinea pig]

40 Guinea pigs were divided into 4 groups.The gingival sulcus of 2 mandibular incisors were irrigated with LPS(Lipopolysaccharide),LTA (Lipoteichoicacid),PL(Subgingival plaque) and NS(Normal saline solution) respectively.2 animals were sacrificed in group of 5 successively at 1,2,3,6,8 week after irrigation.Microscopic examination demonstrated:Only a few penetration of inflammatory cells lay in the gingival tissue in NS control group.Significant infiltrate associated with evident crystal resorption were noted at 1st week and active remodeling took place at 4th,5th week in LPS group.Enhancing accumulations of plaque calculus with weak inflammation could be seen in LTA group.Not only accumulations of plaque and calculus but also penetration of inflammation with resorption of bone were seen in PL group.Their effects on the periodontal tissue of Guinea pig showed evident different.These findings served further expression the possible mechanisms of periodontal diseases.

Anti-shock effect of cyproheptadine in rabbit

Twenty four New Zealand rabbits were equally divided into a cyproheptadine (Cyp) treated group and a control group. Profound hemorrhagic shock was produced by exsanguination via carotid artery until mean arterial pressure (MAP) = 5.3 kPa (40 mm Hg) for a period of 90 min. After given Cyp 10 mg.kg-1, the MAP and central venous pressure (CVP) of the treated group rose obviously (P less than 0.01) and the mesenteric microcirculation improved markedly. After 1 h, all indices returned nearly to the preshock state. The survival rate 2 h after Cyp increased to 12 (P less than 0.01) in comparison with the control group (7). The results showed that Cyp, which dilates the vasculature and improves the microcirculation through blocking serotonin S2 and histamine H1 receptors, has a beneficial anti-shock effect.