共查询到20条相似文献,搜索用时 15 毫秒
1.
Steven N. Anderson Zadok Ruben Gerge C. Fuller 《In vitro cellular & developmental biology. Plant》1990,26(1):61-66
Summary This study was conducted to identify a defined, serum-free culture medium that supports cell dependent contraction of a collagen lattice. Collagen lattices were found to contract in cultures containing human foreskin fibroblasts (HFF) or rabbit aortic smooth muscle (RASM) cells incubated in serum-free medium. HFF and RASM cells required different supplements to contract the collagen gels. HFF cultured in Dulbecco’s modified Eagle’s (DME) medium supplemented with bovine serum albumin (BSA) and either endothelial cell growth supplement (EnGS), insulin (In), or platelet derived growth factor (PDGF) supported collagen lattice contraction. Replacement of BSA with casein without the addition of other supplements improved contraction. In contrast, RASM cells supplemented with BSA, EnGS, In, and PDGF were able to contract collagen gels only minimally. Similar to HFF, RASM cells cultured in DME medium supplemented with casein, but without the addition of other supplements, contracted collagen lattices. HFF-mediated collagen contraction was inhibited by prostaglandins E1 or E2, fibronectin, or ascorbic acid. The reported serum-free model provides a useful in vitro method to investigate the role of serum and nonserum factors regulating cell mediated-contraction of insoluble collagen fibrils. Presented in part as abstract 1963 in the 1985 Federation of American Societies for Experimental Biology, April 21–26, Anaheim, California, and published in Fed. Proc. (44):747; 1985. 相似文献
2.
Tobias Hainz 《Bioethics》2015,29(7):507-515
The application of enhancement technologies to children and non‐medical infant male circumcision are both topics that enjoy the continuous attention of bioethical research but are usually discussed in isolation from each other. Yet one can show that three major arguments used by opponents of the enhancement of children are also applicable to circumcision. These arguments are based on the insecurity of these procedures, the child's right to an open future, and human nature as a foundation of human dignity. People who reject the enhancement of children because of these arguments but accept circumcision hold mutually inconsistent moral convictions or apply double moral standards to these cases. This is particularly important when legislative systems treat the enhancement of children and circumcision in a considerably different manner, which is true for many contemporary legislative systems. At least three strategies can be adopted in order to avoid such inconsistencies, two of which, however, fail for various reasons. According to a third, more promising strategy, circumcision should be subsumed under human enhancement and treated like other enhancement technologies. This strategy justifies restrictions on, but not the prohibition of circumcision. Furthermore, proponents of circumcision should be prepared for future technologies that provide similar benefits as circumcision but are not as contentious as this intervention, so that, in the future, circumcision could become more and more unacceptable. 相似文献
3.
人孤雌胚胎干细胞(human parthenogenetic embryonic stem cells,hPESCs)体外培养常需饲养层的支持以保持干细胞特性.通过原代培养获得人包皮成纤维细胞(human foreskin fibroblasts,hFFs)并将其制备成饲养层,使hPESCs在hFFs上进行体外培养及传代.倒置显微镜下观察hPESCs的生长状态,采用碱性磷酸酶(alkalinephosphatase,AKP)检测、核型分析和体内分化实验研究hPESCs的生物学特性及分化潜能,以探索hFFs能否长期支持hPESCs的生长并维持其未分化状态.经原代培养成功获得了hFFs,通过形态学观察和免疫细胞化学染色鉴定符合成纤维细胞的生物学特性;在hFFs上生长的hPESCs克隆形态规则,不易分化;已成功在体外培养20余代,hPESCs仍能够保持基本生物学特性和正常核型,在裸鼠体内可形成含有3个胚层组织成分的畸胎瘤.作为人源性饲养层,hFFs可长期支持hPESCs的生长并维持其未分化状态. 相似文献
4.
ZALFA A. ABDEL-MALEK VIKI B. SWOPE JAMES J. NORDLUND ESTELA E. MEDRANO 《Pigment cell & melanoma research》1994,7(2):116-122
We report the effects of two factors, donor age and anatomical site, on the proliferation and melanization of human melanocytes (MC) derived from (1) neonatal foreskins, (2) adult foreskins, or (3) adult breast or arm skin. Two different growth media have been used for this purpose. Medium I supports the long-term proliferation of neonatal MC, and medium II supports the growth of both neonatal and adult MC. We found that neonatal foreskin MC proliferated equally well in both media for more than 12 passages. However, adult MC behaved differently in the two growth media. In very early passages (passages 1-5), all three types of MC proliferated well and reached comparable final cell densities in medium I, but adult foreskin MC proliferated at a higher rate than neonatal or adult non-foreskin MC in medium II. The non-foreskin adult MC had the least proliferative rate in medium II. Unlike neonatal MC, both adult foreskin and non-foreskin MC underwent a drastic reduction in their proliferative rate after only a few (9-10) passages in culture. While the three types of MC differed in their proliferative rates, they responded similarly to melanogenic stimulation by cholera toxin (CT) and isobutyl methylxanthine (IBMX). These results demonstrate that the proliferation of human MC in standard culture media is affected by the donor age and the anatomical site from which these cells are derived. We conclude that human MC are heterogeneous, and caution must be used in extrapolating the results of studies on MC derived from different anatomical sites or age groups. 相似文献
5.
Meng GL Zur Nieden NI Liu SY Cormier JT Kallos MS Rancourt DE 《Molecular reproduction and development》2008,75(4):614-622
In embryonic stem (ES) cells, leukemia inhibitory factor (LIF)/STAT3, wnt and nodal/activin signaling are mainly active to control pluripotency during expansion. To maintain pluripotency, ES cells are typically cultured on feeder cells of varying origins. Murine ES cells are commonly cultured on murine embryonic fibroblasts (MEFs), which senesce early and must be frequently prepared. This process is laborious and leads to batch variation presenting a challenge for high-throughput ES cell expansion. Although some cell lines can be sustained by exogenous LIF, this method is costly. We present here a novel and inexpensive culture method for expanding murine ES cells on human foreskin fibroblast (HFF) feeders. After 20 passages on HFFs without LIF, ES cell lines showed normal expression levels of pluripotency markers, maintained a normal karyotype and retained the ability to contribute to the germline. As HFFs do not senesce for at least 62 passages, they present a vast supply of feeders. 相似文献
6.
To Cut or Not to Cut: A Modeling Approach for Assessing the Role of Male Circumcision in HIV Control
A recent randomized controlled trial shows a significant reduction in women-to-men transmission of HIV due to male circumcision.
Such development calls for a rigorous mathematical study to ascertain the full impact of male circumcision in reducing HIV
burden, especially in resource-poor nations where access to anti-retroviral drugs is limited. First of all, this paper presents
a compartmental model for the transmission dynamics of HIV in a community where male circumcision is practiced. In addition
to having a disease-free equilibrium, which is locally-asymptotically stable whenever a certain epidemiological threshold
is less than unity, the model exhibits the phenomenon of backward bifurcation, where the disease-free equilibrium coexists
with a stable endemic equilibrium when the threshold is less than unity. The implication of this result is that HIV may persist
in the population even when the reproduction threshold is less than unity. Using partial data from South Africa, the study
shows that male circumcision at 60% efficacy level can prevent up to 220,000 cases and 8,200 deaths in the country within
a year. Further, it is shown that male circumcision can significantly reduce, but not eliminate, HIV burden in a community.
However, disease elimination is feasible if male circumcision is combined with other interventions such as ARVs and condom
use. It is shown that the combined use of male circumcision and ARVs is more effective in reducing disease burden than the
combined use of male circumcision and condoms for a moderate condom compliance rate. 相似文献
7.
M. J. Kuo C. Lewis Jr. R. A. Martin R. E. Miller R. A. Schoenfeld J. M. Schuck B. S. Wildi 《In vitro cellular & developmental biology. Plant》1981,17(10):901-906
Summary Glycine-derivatized polystyrene beads were prepared and used as microcarriers to grow normal cells of human embryonic kidney,
rhesus monkey kidney, and human foreskin fibroblasts in suspension cultures. Growth of the cells on polystyrene beads derivatized
with other amino acids, peptides, and carboxylic acids also was investigated. 相似文献
8.
Helen Frowe 《Bioethics》2020,34(9):906-911
This paper considers the moral status of bystanders affected by medical research trials. Recent proposals advocate a very low threshold of permissible risk imposition upon bystanders that is insensitive to the prospective benefits of the trial, in part because we typically lack bystanders' consent. I argue that the correct threshold of permissible risk will be sensitive to the prospective gains of the trial. I further argue that one does not always need a person's consent to expose her to significant risks of even serious harm for the sake of others. That we typically need the consent of participants is explained by the fact that trials risk harmfully using participants, which is very hard to justify without consent. Bystanders, in contrast, are harmed as a side-effect, which is easier to justify. I then consider whether the degree of risk that a trial may impose on a bystander is sensitive to whether she is a prospective beneficiary of that trial. 相似文献
9.
小鼠胚胎成纤维细胞(MEFs)是目前国际上公认的人胚胎干细胞(hESCs)体外培养的饲养层细胞,但MEFs存在寿命短、动物源性污染等问题,需要探索适于hESCs体外培养且寿命长的人源性饲养层.采用胰蛋白酶消化法和组织块法分别原代培养人包皮成纤维细胞(hFFs),探索hFFs原代培养的最佳方法,为hFFs作为饲养层在hESCs研究中的应用提供可靠的科学依据;通过倒置显微镜下观察其生长状态和免疫细胞化学染色鉴定,结果显示两种原代培养方法获得的hFFs的形态及生物学特性均符合成纤维细胞;通过测定细胞生长曲线及MTT法检测,结果显示两种原代培养方法获得的不同代数的hFFs均具有较高的增殖活性,传代10余代仍能保持较好的细胞形态,可以制备成饲养层用于hESCs的研究. 相似文献
10.
Mamidi MK Pal R Mori NA Arumugam G Thrichelvam ST Noor PJ Abdullah HM Gupta PK Das AK Zakaria Z Bhonde R 《Journal of cellular biochemistry》2011,112(5):1353-1363
11.
12.
Harrosh S 《Bioethics》2012,26(9):493-498
Moral disagreements often revolve around the issue of harm to others. Identifying harms, however, is a contested enterprise. This paper provides a conceptual toolbox for identifying harms, and so possible wrongdoing, by drawing several distinctions. First, I distinguish between four modes of human vulnerability, forming four ways in which one can be in a harmed state. Second, I argue for the intrinsic disvalue of harm and so distinguish the presence of harm from the fact that it is instrumental to or constitutive of a valued act, practice or way of life. Finally, I distinguish between harm and wrongdoing, arguing that while harm is a normative concept requiring justification, not all harmed states are automatically unjustified. The advantage of this view is that it refocuses the moral debate on the normative issues involved while establishing a common basis to which both sides can agree: the presence of harm to others. 相似文献
13.
Kopelman LM 《Developing world bioethics》2005,5(3):234-243
The Universal Draft Declaration on Bioethics and Human Rights seeks to provide moral direction to nations and their citizens on a series of bioethical concerns. In articulating principles, it ranks respect for human rights, human dignity and fundamental freedoms ahead of respect for cultural diversity and pluralism. This ranking is controversial because it entails the rejection of the popular theory, conventionalist ethical relativism. If consistently defended, this theory also undercuts other United Nations activities that assume member states and people around the world can reach trans-cultural judgments having moral authority about health, pollution, aggression, rights, slavery, and so on. To illustrate problems with conventionalist ethical relativism and the importance of rejecting it for reasons of health, human rights, human dignity and fundamental freedoms, the widespread practice of female genital circumcision or cutting is discussed. These surgeries are virtually a test case for conventionalist ethical relativism since they are widely supported within these cultures as religious and health practices and widely condemned outside them, including by the United Nations. 相似文献
14.
Cell surface effects of human immunodeficiency virus 总被引:3,自引:0,他引:3
Robert F. Garry A. Arthur Gottlieb Kenneth P. Zuckerman John R. Pace Thomas W. Frank Denise A. Bostick 《Bioscience reports》1988,8(1):35-48
Cell killing by human immunodeficiency virus (HIV) is thought to contribute to many of the defects of the acquired immunodeficiency syndrome (AIDS). Two types of cytopathology are observed in HIV-infected cultured cells: cell-cell fusion and killing of single cells. Both killing processes appear to involve cell surface effects of HIV. A model is proposed for the HIV-mediated cell surface processes which could result in cell-cell fusion and single cell killing. The purpose of this model is to define the potential roles of individual viral envelope and cell surface molecules in cell killing processes and to identify alternative routes to the establishment of persistently-infected cells. Elucidation of HIV-induced cell surface effects may provide the basis for a rational approach to the design of antiviral agents which are selective for HIV-infected cells. 相似文献
15.
Bell K 《Medical anthropology quarterly》2005,19(2):125-148
This article explores dominant discourses surrounding male and female genital cutting. Over a similar period of time, these genital operations have separately been subjected to scrutiny and criticism. However, although critiques of female circumcision have been widely taken up, general public opinion toward male circumcision remains indifferent. This difference cannot merely be explained by the natural attributes and effects of these practices. Rather, attitudes toward genital cutting reflect historically and culturally specific understandings of the human body. In particular, I suggest that certain problematic understandings of male and female sexuality are deeply implicated in the dominant Western discourses on genital surgery. 相似文献
16.
BETTINA SHELL-DUNCAN 《American anthropologist》2008,110(2):225-236
ABSTRACT The international campaign to eliminate female genital cutting (FGC) has, since the early 1990s, actively attempted to divorce itself from a health framework, adopting instead a human rights framework to justify intervention. Several key questions emerge regarding the prominent placement of FGC in the international human rights movement: What are the ramifications of framing FGC as a human rights violation? What actions are mandated by a human rights approach? What perils and pitfalls potentially arise from the adoption of a rights-based framework, and how might they be avoided? In exploring these questions it becomes clear that, although a human rights approach is promising, careful deliberation is required to develop action strategies that offer both protection and respect for the culture and autonomy of those women and families concerned. 相似文献
17.
Post-mortem human subjects (PMHS) are frequently used to characterize biomechanical response and injury tolerance of humans to various types of loading by means of instrumentation installed directly on the skeleton. Data extracted from such tests are often used to develop and validate anthropomorphic test devices (ATDs), which function as human surrogates in tests for injury assessment. Given that the location and orientation of installed instrumentation differs between subjects, nominally similar measurements made on different PMHS must be transformed to standardized, skeletal-based local coordinate systems (LCS) before appropriate data comparisons can be made. Standardized PMHS LCS that correspond to ATD instrumentation locations and orientations have not previously been published. This paper introduces anatomically-defined PMHS LCS for body regions in which kinematic measurements are made using ATDs. These LCS include the head, sternum, single vertebrae, pelvis, femurs (distal and proximal), and tibiae (distal and proximal) based upon skeletal landmarks extracted from whole body CT scans. The proposed LCS provide a means to standardize the reporting of PMHS data, and facilitate both the comparison of PMHS impact data across institutions and the application of PMHS data to the development and validation of ATDs. 相似文献
18.
Hua Huang Xiangyu Zou Liang Zhong Yanping Hou Jin Zhou Zhiyuan Zhang Xiaoyu Xing Jie Sun 《Journal of cellular and molecular medicine》2019,23(9):6072-6084
Recently, Leydig cell (LC) transplantation has been revealed as a promising strategy for treating male hypogonadism; however, the key problem restricting the application of LC transplantation is a severe lack of seed cells. It seems that targeted activation of endogenous genes may provide a potential alternative. Therefore, the aim of this study was to determine whether targeted activation of Nr5a1, Gata4 and Dmrt1 (NGD) via the CRISPR/dCas9 synergistic activation mediator system could convert human foreskin fibroblasts (HFFs) into functional Leydig‐like cells. We first constructed the stable Hsd3b‐dCas9‐MPH‐HFF cell line using the Hsd3b‐EGFP, dCas9‐VP64 and MS2‐P65‐HSF1 lentiviral vectors and then infected it with single guide RNAs. Next, we evaluated the reprogrammed cells for their reprogramming efficiency, testosterone production characteristics and expression levels of Leydig steroidogenic markers by quantitative real‐time polymerase chain reaction or Western blotting. Our results showed that the reprogramming efficiency was close to 10% and that the reprogrammed Leydig‐like cells secreted testosterone rapidly and, more importantly, responded effectively to stimulation with human chorionic gonadotropin and expressed Leydig steroidogenic markers. Our findings demonstrate that simultaneous targeted activation of the endogenous NGD genes directly reprograms HFFs into functional Leydig‐like cells, providing an innovative technology that may have promising potential for the treatment of male androgen deficiency diseases. 相似文献
19.
硒是人体必需微量元素,硒与癌症、动脉硬化、心脏病的关系已为人们所熟悉.近年来硒在艾滋病发生发展中的作用越来越引起人们的关注.在HIV感染者及AIDS病人具有渐进性硒衰竭的症状,而病毒及T细胞有可能具有编码硒蛋白的功能,其中一种病毒编码的硒蛋白可能对HIV的表达起抑制作用.在体外,硒对HIV-1的复制具有调节作用.这些为硒的临床应用提供了潜在的前景. 相似文献
20.
Gabrielle Bui Joseph Buckwalter V Jason Wilken John Davison Jeffrey Palmer Don Shurr Nathan Davidson Ignacio Gracia-Fleury Michael Willey 《The Iowa orthopaedic journal》2022,42(1):89
BackgroundHigh energy, lower extremity trauma is associated with longstanding pain and functional limitations. The clinical decision to proceed with early amputation or limb salvage is often controversial. This study was designed to compare differences in complications, costs, and clinical outcomes of below knee amputation (BKA) performed early after injury or after attempted limb salvage in a hospital with standardized prosthetic care following amputation.MethodsThis is a retrospective comparative study of subjects who underwent BKA for a traumatic injury at a single level 1 trauma center and received standardized prosthetic care from a single manufacturer from 1999-2016 with minimum 2-year post-amputation follow up. Outcomes collected included demographics, surgical management, unplanned re-operations, and hospital and prosthetic cost data 2 years from time of injury.ResultsOverall, 79 subjects met criteria. Early amputation (EA) was defined by median duration between injury and amputation (6 weeks) with 41 subjects in the EA group and 38 subjects in the late amputation (LA) group. Subjects in the EA group were more likely to have open fractures, high energy mechanism, and less likely to have medical comorbidities. Post-amputation infection was common in both groups (17/41 (42%) vs 17/38 (45%), p=0.77). Subjects undergoing EA were more likely to require unplanned post-amputation revision, 22/41 (54%) versus 10/38 (27%), p=0.017. Hospital costs and prosthetics/orthotics costs from the time of injury to two years following amputation were comparable, with mean hospital EA costs $136,044 versus LA costs $125,065, p=0.38. Mean prosthetics/orthotics costs of EA subjects were $33,252 versus LA costs $37,684, p=0.59.ConclusionUnplanned post-amputation revision surgeries were more common when BKA was performed early after trauma. Otherwise, outcomes and cost were comparable when amputation was performed early versus late. Level of Evidence: IV 相似文献