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1.
《Addiction biology》2017,22(1):3-43
One of the principal barriers to overcoming addiction is the propensity to relapse, even after months or years of abstinence. Relapse can be precipitated by cues and contexts associated with drug use; thus, decreasing the conditioned properties of these cues and contexts may assist in preventing relapse. The predictive power of drug cues and contexts can be reduced by repeatedly presenting them in the absence of the drug reinforcer, a process known as extinction. The potential of extinction to limit relapse has generated considerable interest and research over the past few decades. While pre‐clinical animal models suggest extinction learning assists relapse prevention, treatment efficacy is often lacking when extinction learning principles are translated into clinical trials. Conklin and Tiffany (Addiction, 2002) suggest the lack of efficacy in clinical practice may be due to limited translation of procedures demonstrated through animal research and propose several methodological improvements to enhance extinction learning for drug addiction. This review will examine recent advances in the behavioural and pharmacological manipulation of extinction learning, based on research from pre‐clinical models. In addition, the translation of pre‐clinical findings—both those suggested by Conklin and Tiffany ( 2002 ) and novel demonstrations from the past 13 years—into clinical trials and the efficacy of these methods in reducing craving and relapse, where available, will be discussed. Finally, we highlight areas where promising pre‐clinical models have not yet been integrated into current clinical practice but, if applied, could improve upon existing behavioural and pharmacological methods. 相似文献
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通过对重组人尿激酶原(rhRhpro-UK)不同剂量(8万IU/kg和16万IU/kg)对家兔纤溶功能的影响并与尿激酶(UK)(8万IU/kg)比较实验显示,rhpro-UK和UK都能明显缩短兔优球蛋白溶解时间,rhpro-UK对纤溶参数影响比UK小.rhpro-UK对体外血栓的溶解作用随剂量增加而增加,与同剂量UK比较有显著差别.rhpro-UK和UK对猪冠脉血栓都有明显的溶栓作用,对猪的纤溶指标纤维蛋白原(FG)、纤溶酶原(PLG)和α2抗纤溶酶(α2-AP)无明显影响.rhpro-UK对出血时间、凝血时间、单位时间内出血量均明显低于UK.表明rhpro-UK的副作用明显低于UK.rhpro-UK对小鼠、大鼠、犬和豚鼠回肠的一般药理学实验表明,rhpro-UK对受试动物的一般行为、状态及中枢神经系统、心血管系统、呼吸系统、消化系统等均无明显影响.仅发现犬实验中手术创面有渗血现象,对全身血液有类似肝素化状态.rhpro-UK的毒理实验表明,rhpro-UK的半数致死量为97.5mg/kg;Beagle犬接受2,8,28mg/kgrhpro-UK后,除8mg和28mg组有一过性牙龈充血,凝血时间明显延长,Tchol,TP和Alb含量有升高趋势外,未观察到明显毒性反应,病理学检查也未观察到药物造成直接的脏器损伤,2mg/kg组未观察到任何毒副反应.特殊毒性实验表明,rhpro-UK没有致突变和致畸作用. 相似文献
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Kaylend Manley Arturo Bravo-Nuevo Allyson R. Minton Summer Sedano Alice Marcy Melvin Reichman Annette Tobia Carol M. Artlett Susan K. Gilmour Lisa D. Laury-Kleintop George C. Prendergast 《Journal of cellular biochemistry》2019,120(7):12051-12062
Meglumine is a methylamino derivative of sorbitol that is an approved drug excipient. Recent preclinical studies suggest that administration of high-dose oral meglumine can exert beneficial medicinal effects to treat diabetes, obesity, and fatty liver disease (NAFLD/nonalcoholic steatohepatitis [NASH]). Here we address gaps in knowledge about the pharmacology and toxicology of this substance administered at high concentrations to explore its medicinal potential. We observed that high-dose meglumine limited secretion of proinflammatory cytokines and cell adhesion molecules from activated human THP-1 or murine RAW264.7 monocytes. Preclinical pharmacokinetic analysis in Swiss mice confirmed that meglumine was orally available. Informed by this data, oral doses of 18 to 75 mM meglumine were administered ad libitum in the drinking water of Sprague-Dawley rats and two cohorts of C57BL/6 mice housed in different vivariums. In a 32-week study, urinary isoprostane levels trended lower in subjects consistent with the possibility of anti-inflammatory effects. In full lifespan studies, there was no detrimental effect on longevity. Heart function evaluated in C57BL/6 mice using an established noninvasive cardiac imaging system showed no detrimental effects on ejection fraction, fractional shortening, left ventricle function or volume, and cardiac output in mice up to 15-month old, with a potential positive trend in heart function noted in elderly mice consistent with earlier reported benefits on muscle stamina. Finally, in a transgenic model of inflammation-associated skin carcinogenesis, the incidence, number, and growth of skin tumors trended lower in subjects receiving meglumine. Overall, the evidence obtained illustrating the long-range safety of high-dose oral meglumine support the rationale for its evaluation as a low-cost modality to limit diabetes, hypertriglyceridemia, and NAFLD/NASH. 相似文献
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During 2000 research on the pharmacology of marine chemicals involved investigators from Australia, Brazil, Canada, Egypt, France, Germany, India, Indonesia, Israel, Italy, Japan, the Netherlands, New Zealand, Phillipines, Singapore, Slovenia, South Korea, Spain, Sweden, Switzerland, United Kingdom, and the United States. This current review, a sequel to the authors 1998 and 1999 reviews, classifies 68 peer-reviewed articles on the basis of the reported preclinical pharmacologic properties of marine chemicals derived from a diverse group of marine animals, algae, fungi, and bacteria. Antibacterial, anticoagulant, antifungal, antimalarial, antiplatelet, antituberculosis, or antiviral activity was reported for 35 marine chemicals. An additional 20 marine compounds were shown to have significant effects on the cardiovascular and nervous system, and to possess anti-inflammatory or immunosuppressant properties. Finally, 23 marine compounds were reported to act on a variety of molecular targets and thus could potentially contribute to several pharmacologic classes. Thus, as in 1998 and 1999, during 2000 pharmacologic research with marine chemicals continued to contribute potentially novel chemical leads to the ongoing global search for therapeutic agents in the treatment of multiple disease categories. 相似文献
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Carleer J Karres J 《Birth defects research. Part B, Developmental and reproductive toxicology》2011,92(4):254-260
During the workshop organized by ILSI/HESI on May 5-6, 2010 on the value of juvenile animal toxicity studies, the implementation of the European Pediatric Regulation and in particular the review process of the nonclinical part of the Pediatric Investigation Plan (PIP) were described. A PIP is intended to outline the development of a medicinal product in the pediatric population (i.e. quality, safety, efficacy of the medicine and timing of studies); it is reviewed and agreed by the Pediatric Committee (PDCO) of the European Medicines Agency (EMA). The Nonclinical Working Group (NcWG) supports the PDCO in the review process of the nonclinical part of a PIP and is composed of members from the PDCO, the EMA Safety Working Party, additional experts from national competent authorities and the FDA. This article summarizes the NcWG review process and outcomes of 97 approved or ongoing PIPs, from the establishment of the NcWG in November 2008 to May 2010, as presented during the workshop. Juvenile animal studies were proposed by the applicant in 33% or required by the NcWG in 26% of the PIPs. The requirements were mainly motivated by concerns regarding potential developmental toxicities, in view of the young age of the pediatric population to be investigated, the lack of knowledge concerning the maturation of the pharmacological target, the lack of sufficient (non)clinical data, observed toxicities in the adult (non)clinical studies and the long duration of the intended treatments. Most juvenile animal studies were in the therapeutic areas of oncology, infectious diseases and endocrinology. In about 14% of the PIPs submitted, the NcWG requested either justifications of, or amendments to the study designs proposed by the applicants (e.g. justification of endpoints, study duration, species selection and timing with regards to clinical pediatric studies). Generally, only one species was selected or proposed for the juvenile studies, the rat being the most prevalent. The number of juvenile studies initially proposed by the applicant plus those requested by the NcWG was higher than the number of studies included in the \"key binding elements\" of the PIP opinions. This apparent discrepancy was mainly due to additional information or justifications submitted by the applicant during the clock stop. It was noted that the PIPs initially submitted often lacked information relevant to the nonclinical evaluation. Therefore, during the workshop, the need to provide scientifically based justifications when no juvenile animal studies are proposed in the initial PIP submission was stressed. 相似文献
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Golub MS Kaufman FL Campbell MA Li LH Donald JM 《Birth defects research. Part B, Developmental and reproductive toxicology》2006,77(5):455-470
BACKGROUND: A variety of progestational agents have been used therapeutically and evaluated for adverse effects over the last 50 years. However, progesterone itself has come into use as a therapeutic agent only recently with the development of an orally bioavailable \"micronized\" preparation. METHODS: The current review examines progesterone adverse effects as identified in the larger literature on the toxicity of progestational agents and pharmacokinetics. RESULTS: Progesterone has cytoplasmic and membrane receptors in a variety of reproductive and nonreproductive tissues including the brain and is a potent inhibitor of GnRH. Limited information is available on progesterone receptors and actions in the fetus. Concern about exogenous progestagen effects on fetal reproductive tract development have led to considerable human research over the years, but this literature review demonstrates that contemporary developmental toxicology research on progesterone is lacking. CONCLUSIONS: Progesterone is a potent, multi-faceted endocrine agent with an expanding therapeutic profile and a minimal scientific database for evaluating safe use during pregnancy. 相似文献
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Jeanette Bierwolf Marc Lutgehetmann Kai Feng Johannes Erbes Steffen Deichmann Eva Toronyi Christina Stieglitz Bjoern Nashan Peter X. Ma Joerg M. Pollok 《Biotechnology and bioengineering》2011,108(1):141-150
Primary rat hepatocytes are a widely used experimental model to estimate drug metabolism and toxicity. In currently used two‐dimensional (2D) cell culture systems, typical problems like morphological changes and the loss of liver cell‐specific functions occur. We hypothesize that the use of polymer scaffolds could overcome these problems and support the establishment of three‐dimensional (3D) culture systems in pharmaceutical research. Isolated primary rat hepatocytes were cultured on collagen‐coated nanofibrous scaffolds for 7 days. Cell loading efficiency was quantified via DNA content measurement. Cell viability and presence of liver‐cell‐specific functions (albumin secretion, glycogen storage capacity) were evaluated. The activity of liver‐specific factors was analyzed by immunofluorescent staining. RNA was isolated to establish quantitative real‐time PCR. Our results indicate that primary rat hepatocytes cultured on nanofibrous scaffolds revealed high viability and well‐preserved glycogen storage. Albumin secretion was existent during the entire culture period. Hepatocytes remain HNF‐4 positive, indicating highly preserved cell differentiation. Aggregated hepatocytes re‐established positive signaling for Connexin 32, a marker for differentiated hepatocyte interaction. ZO‐1‐positive hepatocytes were detected indicating formation of tight junctions. Expression of cytochrome isoenzymes was inducible. Altogether the data suggest that nanofibrous scaffolds provide a good in vitro microenvironment for neo tissue regeneration of primary rat hepatocytes. Biotechnol. Bioeng. 2011; 108:141–150. © 2010 Wiley Periodicals, Inc. 相似文献
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石墨烯是一种新型的二维碳纳米材料,由于具有优异的电子、光学、机械等特性,已经被广泛应用于电子器件、复合材料、能源储存等领域.近年来,石墨烯在生物医药领域崭露头角,其在诸如生物传感器、细胞成像、药物输运、抗菌材料等方面的广泛应用,为生物医药技术带来了突破,也为人体健康带来了福音.然而,随着石墨烯以不同途径进入人们的生活,其对人体及其他生物体的安全构成潜在威胁,引发的健康风险正受到广泛关注.本文从石墨烯对生物体的影响及其同生物体的相互作用方面入手,综述了近年来石墨烯健康风险的研究进展,并且总结归纳了人体抵御石墨烯健康风险的途径及机制,最后指出了未来石墨烯健康风险方面的研究方向. 相似文献
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John F. Leatherland 《Environmental Biology of Fishes》1982,7(1):83-110
Synopsis Recent studies of thyroid hormone function are reviewed as they relate to the environmental physiology of teleost fish. In addition, reports dealing with the apparent interdependence of thyroid gland function with that of other endocrine glands are discussed with emphasis on the interrelated endocrine response associated with changing physiological status of teleosts.Seasonal changes in thyroid gland activity are described in several species. Although seasonal alterations in apparent thyroid status are concomitant with changes in ambient temperature, photoperiod and/or gonadal status, their biological significance is not fully understood and direct relationships are for the most part, not proven. Similarly, most reports of thyroid involvement in gonadal development or maturation are based on indirect evidence of the relationship. The exception to this is a study in immature or hypophysectomized goldfish in which thyroxine (T4) was shown to promote ovarian development and maturation, possibly acting collateralistically or synergistically with gonadotropin. Even in this study it is not clear whether the T4 effect is a direct action on the ovarian tissue or an indirect action via the regulation of metabolites necessary for gonad metabolism. Integumentary silvering and retinal porphyropsin formation in salmonids are stimulated by administration of T4 or thyroid extracts. Administration of T4 or triiodothyronine (T3) enhances skeletal and somatic growth in some teleostean species, although the effect on somatic growth is most pronounced when these hormones act synergistically with somatotropin (STH) or androgens. The growth-promoting effects of T4 and T3 may be linked to their apparent involvement in lipid, carbohydrate, protein and vitamin metabolism. alterations in apparent thyroid activity concomitant with changes in ambient temperature have been reported (for example correlated with seasonal ambient thermal changes), although there are marked contradictions in data presented by different investigators. Reported temperature-related effects on thyroid function are probably secondary responses of thyroid metabolism to altered temperatures. Evidence of a direct rate of thyroid hormones in the regulation of migration (and associated behavioural modifications), salmonid smoltification, oxygen consumption, and osmotic or ionic regulation although highly suggestive in a number of areas is inconclusive and requires further critical experimental evaluation.The pituitary control (by thyrotropin) of thyroid secretion of T4 is convincingly shown in several teleosts, and evidence of an inhibitory hypothalamic control of thyrotrop activity is highly suggestive in some species. A thyrotropic effect of somatotropin preparations is well established in several teleostean species; the effect does not appear to be related to contamination of the somatotropin preparations with thyrotropin, and may be an important consideration in explaining the apparently related involvement of T4 (or T3) and somatotropin in growth and metabolism. The apparent thyrotropic property of some gonadotropin preparations, shown in several teleostean species, requires further investigation before the doubts regarding hormone preparation purity can be satisfied. Recent studies of effects of prolactin on thyroid function are highly suggestive of an inhibitory role of prolactin in peripheral monodeiodination of T4 to T3 which secondarily affects thyroid activity in some species. There is no evidence of a direct involvement of corticotropin, melanotropin or fractions of these molecules on thyroid function in teleosts. Moreover, the little evidence in support of a role of gonadal or adrenocortical steroids in thyroid control is either often contradictory or indirect and needs to be evaluated further.Interlake epizootiological studies of thyroid dysfunction in Great Lakes salmonids provide substantive evidence for the presence of a ubiquitous waterborne goitrogen(s) in the Great Lakes environs. The nature of the goitrogen(s), whether naturally-occurring or a man-introduced toxicant, remains to be determined but the possible existence of waterborne goitrogens in natural water systems and their possible effects on experimental studies of teleostean thyroid function have to be evaluated further. If goitrogens are a common component of aquatic environments their presence could explain some of the data discrepancy among different groups of investigators, and could account for some of the apparent seasonal change in teleost thyroid physiology. 相似文献
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Objectives: To investigate the recall of oral health knowledge and confidence by nursing personnel in special housing facilities for the elderly, three years after an education programme. Design: A cross sectional design using a questionnaire. Sample: All nursing personnel, a total of 2,901 subjects, in five municipalities in south‐western Sweden; of whom 950 had attended the programme. The response rate was 67% (1930 subjects). Intervention: An oral health education programme consisting of four one‐hour lessons. Results: The oral health education programme still had an effect on the participants' attitudes towards oral health three years later. When comparing the trained group (OHEP+) which attended the programme with those who did not have training (OHEP‐), the perceived ability, opportunity and the knowledge of oral health were significantly better in the former group, p<0.01 Eurther, within the OHEP‐ group who did not attend the programme there was a significant difference in the perceived ability, opportunity and the knowledge of oral health between those with a higher level of health care education, p<0.01. Conclusions: The effect of an oral health education programme on the participants' attitudes towards oral health persists at least for three years. The data indicate that trainees with a low level of health care education benefit most. 相似文献
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Conventional noncancer assessment involves the computation of hazard quotients (HQ), simple ratios of an individual’s or a population’s estimated chemical intake, and a reference dose (the RfD) that is held to reflect a safe level of exposure. HQs?>?1, indicating RfD exceedance, have considerable uncertainty for two reasons. It is not known that the critical effect of the animal study that supports the RfD is adverse (i.e., harmful), and it is unclear at what dose higher than an RfD, truly health compromising effects are triggered. Through methodically reviewing critical studies of the U.S. EPA’s IRIS database, we investigated the efficacy of the present assessment scheme with its considerable emphasis on RfD development. Aside from noted inconsistencies in reporting, and a substantial percentage of oral noncarcinogens having a less than ideal toxicological review source, our analysis found numerous instances of absent toxicological information to fuel HQ computation, with this largely a function of the dated nature of the supporting studies. In light of our analysis, we propose a recommended replacement scheme for noncancer assessment. In place of estimating the degree to which RfDs are exceeded, we recommend determining whether Truly Adverse Doses (TADs), to be newly developed, are approached. 相似文献
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Jack H Dean Harry M Olson 《Biology of the cell / under the auspices of the European Cell Biology Organization》1993,77(1):3-8
Summary— Integrating toxicology early in the drug discovery process adds value by providing the earliest possible identification of a compound's potential for toxicological and pathological effects relevant to intended clinical use. With this approach true ‘lead’ candidates, with a high probability of clinical success, are identified and advanced while reducing effort and resources expended on compounds without the requisite therapeutic index. Resources are focussed on the speed of getting a discovery ‘lead’ into early clinical development, defining the mechanisms of observed preclinical toxicity and their relevance to human use, and developing early safety data with in vitro test systems ahead of in vivo systems where possible, thus reducing animal use. 相似文献
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Xinguang Chen 《The Yale journal of biology and medicine》2014,87(3):231-240
The concept of “global health” that led to the establishment of the World Health Organization in the 1940s is still promoting a global health movement 70 years later. Today’s global health acts first as a guiding principle for our effort to improve people’s health across the globe. Furthermore, global health has become a branch of science, “global health science,” supporting institutionalized education. Lastly, as a discipline, global health should focus on medical and health issues that: 1) are determined primarily by factors with a cross-cultural, cross-national, cross-regional, or global scope; 2) are local but have global significance if not appropriately managed; and 3) can only be efficiently managed through international or global efforts. Therefore, effective global health education must train students 1) to understand global health status; 2) to investigate both global and local health issues with a global perspective; and 3) to devise interventions to deal with these issues. 相似文献
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Yuzhe Du Yoshiko Nomura Boris S. Zhorov Ke Dong 《The Journal of biological chemistry》2016,291(9):4638-4648
1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), the first organochlorine insecticide, and pyrethroid insecticides are sodium channel agonists. Although the use of DDT is banned in most of the world due to its detrimental impact on the ecosystem, indoor residual spraying of DDT is still recommended for malaria control in Africa. Development of resistance to DDT and pyrethroids is a serious global obstacle for managing disease vectors. Mapping DDT binding sites is necessary for understanding mechanisms of resistance and modulation of sodium channels by structurally different ligands. The pioneering model of the housefly sodium channel visualized the first receptor for pyrethroids, PyR1, in the II/III domain interface and suggested that DDT binds within PyR1. Previously, we proposed the second pyrethroid receptor, PyR2, at the I/II domain interface. However, whether DDT binds to both pyrethroid receptor sites remains unknown. Here, using computational docking of DDT into the Kv1.2-based mosquito sodium channel model, we predict that two DDT molecules can bind simultaneously within PyR1 and PyR2. The bulky trichloromethyl group of each DDT molecule fits snugly between four helices in the bent domain interface, whereas two p-chlorophenyl rings extend into two wings of the interface. Model-driven mutagenesis and electrophysiological analysis confirmed these propositions and revealed 10 previously unknown DDT-sensing residues within PyR1 and PyR2. Our study proposes a dual DDT-receptor model and provides a structural background for rational development of new insecticides. 相似文献
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