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101.
Amyloid-Beta Immunization in Alzheimer's Disease Transgenic Mouse Models and Wildtype Mice 总被引:1,自引:0,他引:1
Lemere CA Spooner ET Leverone JF Mori C Iglesias M Bloom JK Seabrook TJ 《Neurochemical research》2003,28(7):1017-1027
Alzheimer's disease is the most prevalent form of dementia worldwide. Therapies are desperately needed to prevent and cure the disease. Mouse models of amyloid- deposition [APP and PSAPP transgenic (tg) mice] have been useful in determining the role of amyloid- (A) in both the pathogenesis and cognitive changes in AD. In addition, they have allowed scientists to investigate potential AD therapies in living animals. Active and passive A immunizations have been employed successfully in APP and PSAPP tg mice to lower cerebral A levels and improve cognition. Optimization of immunization protocols and characterization of immune responses in wildtype mice have been reported. Based on the promising results of A immunization studies in mice, a clinical trial was initiated for A vaccination in humans with AD. Although no adverse effects were reported in the Phase I safety trials, about 5% of AD patients in the phase II clinical trial developed meningoencephalitis, ending the trial prematurely in March 2002. Studies in AD mouse models and wildtype mice may help elucidate the mechanism for these unwanted side effects and will be useful for testing newer, safer vaccines for future use in human clinical trials. 相似文献
102.
Salmonella typhimurium vaccine strains were used as antigen delivery system for oral immunisation of chickens against two antigens of the coccidian parasite Eimeria tenella. The cDNAs of the known E. tenella proteins, SO7 and TA4, were isolated from total RNA and subcloned into the expression vectors pQE30 and pTECH2. Subcutaneous immunisation of chickens with Escherichia coli-expressed SO7 and TA4 revealed that both proteins were immunogenic. Both cDNAs were subcloned into plasmids of the pTECH2 vector system, which allows them to be expressed as fusion proteins with the highly immunogenic fragment C of the tetanus toxin under control of the anaerobically inducible nirB promoter. Plasmids were introduced into the S. typhimurium vaccine strains SL3261, C5aroD and C5htrA. SDS-PAGE and Western blot analysis revealed expression of both fusion proteins in all strains under anaerobic culture conditions. Three-week-old white leghorn chickens were orally immunised with 10(9) CFU per animal. The stability of the recombinant bacteria was revealed by recovery of viable Salmonella containing the respective plasmids from the liver of the immunised chickens at day 3 after inoculation. Specific serum IgG antibodies against the SO7-or TA4-antigens were detectable by ELISA 2 weeks after oral immunisation and remained for at least 6 weeks, while specific IgA antibodies were restricted to the bile of the birds. All chickens produced serum IgG and IgA to S. typhimurium lipopolysaccharides. Our data show that a single oral inoculation with recombinant S. typhimurium SL3261, C5aroD and C5htrA can induce specific antibody responses to heterologous Eimeria antigens in chickens, suggesting that recombinant Salmonella are a suitable delivery system for vaccines against Eimeria infections. 相似文献
103.
Aim of this study was to elaborate an efficient method for the micronization of the decapeptide cetrorelix (a GnRH-antagonist),
in order to obtain a microsuspension as basis for other pharmaceutical preparations, such as e.g. inhalation aerosols. A modified
pearl-mill coupled with a cryostat was used for the micronization of cetrorelix in fluid propellant and operated under different
conditions. The obtained cetrorelix suspensions were analyzed for particle size distribution, purity of cetrorelix, and for
metal contamination through abrasion from parts of the mill. The method allowed an effective micronization of cetrorelix.
The mean particle size of the initial cetrorelix lyophilizate bulk ware was reduced from 52.5 μ (Volume Mean Diameter, VMD)
down to 14.9, 6.1 and 3.1 μm, respectively, respectively. The HPLC analysis of all cetrorelix suspensions after micronization
did not show signs of decomposition as compared to the initial product. The elementary analysis of the suspensions performed
by inductively coupled plasma mass spectrometry revealed a negligible amount of contaminants in the suspension (Zr=max. 0.6
ppm; Fe, Cr, Ni, Ba, below limit of quantification, i.e.<0.14 ppm). The only appreciable contaminant. Aluminum (Al=1.1 ppm),
was derived from the mechanical capping of aluminum canisters prior to analysis. The Zr determination in the suspension of
0.6 ppm, is still considered to be negligible as compared to the legally tolerated limit of air contamination. By low-temperature
micronization in fluid propellant, fine drug suspensions of cetrorelix for pMDIs can be directly manufactured in one-step
procedure without destruction of the peptide structure and without appreciable product contamination.
Published: July 12, 2001. 相似文献
104.
Joanne Blanchfield Julie Dutton Ron Hogg David Craik David Adams Richard Lewis Paul Alewood Istvan Toth 《Letters in Peptide Science》2001,8(3-5):235-239
The -conotoxin MII is a 16 amino acid long peptide toxinisolated from the marine snail, Conus magus. This toxinhas been found to be a highly selective and potent inhibitorof neuronal nicotinic acetylcholine receptors of the subtype32. To improve the bioavailability of this peptide, we havecoupled to the N-terminus of conotoxin MII, 2-amino-D,L-dodecanoic acid (Laa) creating a lipidic linear peptide whichwas then successfully oxidised to produce the correctly foldedconotoxin MII construct. 相似文献
105.
Enzyme replacement therapy has been shown to be particularly effective for patients with type 1 (non-neuronopathic) Gaucher disease. However, intravenously administered glucocerebrosidase does not reverse or halt the progression of brain damage in patients with type 2 (acute neuronopathic) Gaucher disease. A previous investigation revealed that intracerebral infusion of mannose-terminal glucocerebrosidase was safe in experimental animals. The enzyme had a comparatively long half-life in the brain. It was transported by convection from the site of infusion along white matter fiber tracts to the cerebral cortex where it was endocytosed by neurons. In anticipation of intracerebral administration of mannose-terminal glucocerebrosidase to patients with type 2 Gaucher disease, it was important to learn the mechanism involved in its cellular uptake. We therefore compared the endocytosis of this enzyme by J774 macrophage cells with that in two human neuronal cell lines and a human astrocyte cell line. Mannose-terminal glucocerebrosidase was taken up by cholinergic LA-N-2 cells, but to a much lower extent than by macrophages. Considerably less of the enzyme was endocytosed by dopaminergic SH-SY5Y cells. It was not taken up by NHA astrocytes. The findings provide encouragement for an exploration of intracerebral administration of glucocerebrosidase in patients with type 2 Gaucher disease. 相似文献
106.
From circadian rhythms to cancer chronotherapeutics 总被引:14,自引:0,他引:14
Lévi F 《Chronobiology international》2002,19(1):1-19
Mammalian circadian rhythms result from a complex organization involving molecular clocks within nearly all “normal” cells and a dedicated neuroanatomical system, which coordinates the so-called “peripheral oscillators.” The core of the central clock system is constituted by the suprachiasmatic nuclei that are located on the floor of the hypothalamus. Our understanding of the mechanisms of circadian rhythm generation and coordination processes has grown rapidly over the past few years. In parallel, we have learnt how to use the predictable changes in cellular metabolism or proliferation along the 24h time scale in order to improve treatment outcome for a variety of diseases, including cancer. The chronotherapeutics of malignant diseases has emerged as a result of a consistent development ranging from experimental, clinical, and technological prerequisites to multicenter clinical trials of chronomodulated delivery schedules. Indeed large dosing-time dependencies characterize the tolerability of anticancer agents in mice or rats, a better efficacy usually results from treatment administration near the least toxic circadian time in rodent tumor models. Programmable in time multichannel pumps have allowed to test the chronotherapy concepts in cancer patients and to implement chronomodulated delivery schedules in current practice. Clinical phase I and II trials have established the feasibility, the safety, and the activity of the chronotherapy schedules, so that this treatment method has undergone further evaluation in international multicenter phase III trials. Overall, more than 2000 patients with metastatic disease have been registered in chronotherapy trials. Improved tolerability and/or better antitumor activity have been demonstrated in randomized multicenter studies involving large patient cohorts. The relation between circadian rhythmicity and quality of life and even survival has also been a puzzling finding over the recent years. An essential step toward further developments of circadian-timed therapy has been the recent constitution of a Chronotherapy cooperative group within the European Organization for Research and Treatment of Cancer. This group now involves over 40 institutions in 12 countries. It is conducting currently six trials and preparing four new studies. The 19 contributions in this special issue reflect the current status and perspectives of the several components of cancer chronotherapeutics. 相似文献
107.
Pharmaco-economic comparative evaluation of combination chronotherapy vs. standard chemotherapy for colorectal cancer 总被引:6,自引:0,他引:6
Focan C 《Chronobiology international》2002,19(1):289-297
Results of recent trials comparing combination chemotherapy consisting of 5-fluorouracil (5-FU), folinic acid (FOL), and oxaliplatin, given either as flat (A) or chronomodulated (B) infusion for metastatic colorectal cancer, were subjected to pharmaco-economic evaluation. The overall cost of treatment with the flat and chronomodulated protocols was equivalent. The expense of the delivery of medications with the chronotherapeutic arm (B) was greater than with the standard arm (A) because it was feasible to administer more courses (requiring more frequent doctor visits) and higher doses (high cost of medications) with containment of toxic reactions. Chrono-arm B was definitively more cost-effective than standard flat-arm A treatment since it made the outcome of treatment more effective; there was greater tumor response rate and longer time to progression with less treatment-associated toxicity. Finally, selection of the Melodie brand infusion pump to deliver the chronotherapy resulted in a further 18% reduction of overall costs and made it possible for patients to enjoy increased autonomy and improved quality of life. 相似文献
108.
Neurodegenerative diseases as a class do not have effective pharmacotherapies. This is due in part to a poor understanding of the pathologies of the disease processes, and the lack of effective medications. Gene delivery is an attractive possibility for treating these diseases. For the paradigm to be effective, efficient, safe and versatile vectors are required. In this study we evaluated three plasmid delivery systems for transgene expression in the rat hippocampus. Two of these systems were designed to have enhanced intracellular biodegradability. It was hypothesized that this system would be less toxic and could increase the free (non-vector) associated plasmids within the cell, leading to increased transgene activity. Polyethylenimine (PEI) and r-AAV-2 (recombinant adeno associated virus-2) were used as positive, non-viral and viral controls respectively, in the in vivo experiments. The results from the studies indicate there is a distinct difference between the various vectors in terms of total cells transfected, type of cell transfected, and toxicity. Non-viral systems were effective at transfecting both neurons and glia cells within the hippocampus, while the r-AAV-2 transfected mainly neurons. In summary, plasmid-mediated systems are effective for transgene expression within the brain and deserve further study. 相似文献
109.
Cyotomedical therapy for insulinopenic diabetes using microencapsulated pancreatic beta cell lines 总被引:3,自引:0,他引:3
Suzuki R Okada N Miyamoto H Yoshioka T Sakamoto K Oka H Tsutsumi Y Nakagawa S Miyazaki J Mayumi T 《Life sciences》2002,71(15):1717-1729
Current therapy for type 1 diabetes mellitus involves a daily regimen of multiple subcutaneous or intramuscular injections of recombinant human insulin. To achieve long-term insulin delivery in vivo, we investigated the applicability of cytomedical therapy using beta TC6 cells or MIN6 cells, both of which are murine pancreatic beta cell lines that secrete insulin in a subphysiologically or physiologically regulated manner, respectively. We examined this therapy in the insulinopenic diabetic mice intraperitoneally injected with beta TC6 cells or MIN6 cells microencapsulated within alginate-poly(L)lysine-alginate membranes (APA-beta TC6 cells or APA-MIN6 cells). The diabetic mice treated with APA-beta TC6 cells fell into hypoglycemia, whereas those injected with APA-MIN6 cells maintained normal blood glucose concentrations for over 2 months without developing hypoglycemia. In addition, we also conducted an oral glucose tolerance test using these mice. The blood glucose concentrations of normal and of diabetic mice injected with APA-MIN6 cells similarly changed over time, although the blood insulin concentration increased later in the injected diabetic mice than in the former. These results suggest that cytomedicine utilizing microencapsulated pancreatic beta cell lines with a physiological glucose sensor may be a beneficial and safe therapy with which to treat diabetes mellitus. 相似文献
110.
Response surface methodology for the optimization of ubiquinone self-nanoemulsified drug delivery system 总被引:1,自引:0,他引:1
The aim of the present study was to prepare and evaluate an optimized, self-nanoemulsified drug delivery system of ubiquinone.
A 3-factor, 3-level Box-Behnken design was used for the optimization procedure with the amounts of Polyoxyl 35 castor oil
(X1), medium-chain mono- and diglyceride (X2), and lemon oil (X3) as the independent variables. The response variable was the cumulative percentage of ubiquinone emulsified in 10 minutes.
Different ubiquinone release rates were obtained. The amount released ranged from 11% to 102.3%. Turbidity profile revealed
3 regions that were used to describe the progress of emulsion formation: lag phase, pseudolinear phase, and plateau turbidity.
An increase in the amount of surfactant decreased turbidity values and caused a delay in lag time. Addition of cosurfactant
enhanced the release rates. Increasing the amount of the eutectic agent was necessary to overcome drug precipitation especially
at higher loading of surfactants and cosurfactants. Mathematical equations and response surface plots were used to relate
the dependent and independent variables. The regression equation generated for the cumulative percentage emulsified in 10
minutes was Y1=90.9–22.1X1+5.03X2+13.95X3+12.13X1X2+15.13X1X3-14.40X1
2-6.25X3
2. The optimization model predicted a 93.4% release with X1, X2, and X3 levels of 35, 35, and 30 respectively.
The observed responses were in close agreement with the predicted values of the optimized formulation. This demonstrated the
reliability of the optimization procedure in predicting the dissolution behavior of a self-emulsified drug delivery system.
Published: February 8, 2002. 相似文献