There is considerable interest in the biology and therapeutic potential of adult stem cells from bone marrow stroma, variously referred to as mesenchymal stem cells or marrow stromal cells (MSCs). Human MSCs can expand rapidly in culture, but the rate of expansion and the yields of multipotential progenitors are inversely related to the plating density and incubation time of each passage. We have defined conditions for optimizing the yields of cultures enriched for early progenitors. Also, we developed a simple method for assessing the quality of the cultures by phase-contrast microscopy and image analysis or by forward light scatter in a flow cytometer. The cells expanded most rapidly on day 4 after plating, with a minimum average doubling time of about 10 hours for cells initially plated at 10 or 50 cells/cm(2). After plating the cells at 1 to 1000 cells/cm(2), the cultures underwent a time-dependent transition from early progenitors, defined as thin, spindle-shaped cells (RS-1A), to wider, spindle-shaped cells (RS-1B), and to still wider, spindle-shaped cells (RS-1C). Assays for adipogenesis demonstrated that the adipogenic potential of cultures was directly related to their ability to generate single-cell-derived colonies and their enrichment for RS-1A cells. In contrast, cultures enriched for RS-1B cells showed the greatest potential to differentiate into cartilage in a serum-free system. The results indicate that, when preparing cultures of human MSCs, it is necessary to compromise between conditions that provide the highest overall yields and those that provide the highest content of early progenitor cells. 相似文献
Background: EEG sleep measures in child and adolescent subjects with depression have shown considerable variability regarding group differences between depressed and control subjects. This investigation was designed to assess whether some of the observed variability is related to undifferentiated unipolar and bipolar disorders in a sample that was reported previously. Methods: Twenty-eight adolescents who met criteria for unipolar major depression and 35 controls with no lifetime psychiatric disorder participated in a cross-sectional sleep polysomnography study. Approximately 7 years later, follow-up clinical evaluations were conducted in 94% of the original cohort. Clinical course during the interval period was assessed without knowledge of subjects’ initial diagnostic and psychobiological status. Re-analysis of the original sleep data were performed with the added information of longitudinal clinical course. Results: Depressed subjects who had a unipolar course showed reduced REM latency, higher REM density, and more REM sleep (specifically in the early part of the night) compared with depressed adolescents who converted to bipolar disorder and controls who remained free from psychopathology at follow-up. In contrast to the unipolar group, depressed subjects who would later switch to bipolar disorder had demonstrated more stage 1 sleep and diminished stage 4 sleep. Conclusions: These preliminary results indicate that some of the observed variability in EEG sleep measures in adolescent depression appear to be confounded by latent bipolar illness. The findings also suggest that sleep regulatory changes associated with unipolar versus bipolar mood disorders may be different. 相似文献
In India, substantial efforts have been made to increase awareness about HIV/AIDS among female sex workers (FSWs). We assessed the impact of awareness regarding safe sex in a cohort of FSWs by studying trends in HIV prevalence, sexually transmitted diseases (STDs), and risk behaviors measured from 1993 to 2002 in Pune, India. A total of 1359 FSWs attending 3 STD clinics were screened for HIV infection, and data on demographics, sexual behaviors, and past and current STDs were obtained. The overall HIV prevalence among FSWs was 54%. Not being married (adjusted odds ratio [AOR] = 1.74, 95% confidence interval [CI]: 1.17 to 2.59), being widowed (AOR = 2.10, 95% CI: 1.16 to 3.80), inconsistent condom use (AOR = 1.60, 95% CI: 1.02 to 2.50), clinical presence of genital ulcer disease (GUD; AOR = 1.66, 95% CI: 1.07 to 2.56), and genital warts (AOR = 4.70, 95% CI: 1.57 to 14.08) were independently associated with HIV infection among FSWs. The prevalence of HIV remained stable over 10 years (46% in 1993 and 50% in 2002; P = 0.80). The prevalence of GUD decreased over time (P < 0.001), whereas that of observed genital discharge remained stable. Reported consistent condom use as well as the proportion of FSWs who refused sexual contact without condoms increased over time (P < 0.001). These data collectively suggest that safe sex interventions have had a positive impact on FSWs in Pune, India. 相似文献
Endometriosis is a well-known precursor lesion of ovarian malignancies, particularly those of endometrioid and clear-cell types and rarely of serous or mucinous types. The association of endometriosis with mucinous borderline tumors also varies. This case is of a 60 year old female, who had a long history of more than thirty years of endometriosis and developed recurrent endocervical-like mucinous borderline tumor (ELMBT) in endometriotic foci. This case highlights challenges in the management of such complications associated with endometriosis and emphasizes the importance of long-term follow-up in cases of endometriosis. 相似文献
Polymeric micelles are widely used as multifunctional drug carriers of poorly water-soluble drugs, but the role of drug loading content is often overlooked. The purpose of this study is to investigate the cellular uptake and penetration of polymeric micelles with different drug loading contents and their effects on biological activities. In this study, poly(N-(2-hydroxypropyl) methacrylamide-co-methacrylic acid)-block-poly methyl methacrylate P(HPMA-co-MAA)-b-PMMA micelles are used as a nanocarrier for the encapsulation of the potent anticancer agent ellipticine (EPT). The micelles are loaded with various amounts of EPT and the physicochemical characteristics such as particle size, morphology, and zeta potential of blank and EPT loaded nanoparticles are studied. Moreover, fluorescent lifetime studies confirm that hydrophobic EPT is indeed in the PMMA micelle core. In vitro cytotoxicity tests using the glioma cell line U87MG reveal lower IC50 values when the cells are incubated with micelle with high drug loading content. The higher toxicity in micelles with higher drug loading content is associated with higher cellular uptake, which is monitored using laser scanning confocal microscopy and flow cytometry. Moreover, higher activity of micelles with higher drug loading is also observed in U87MG multicellular tumor spheroids although the difference is not significant. 相似文献
Objectives Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide. We adapted a rat model of atherosclerosis to study brain intracranial atherosclerosis, and further investigated how omega-3 fatty acids (O3FA) attenuated the development of ICAS by reducing the generation of reactive oxygen species (ROS) and the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity.
Methods Adult male Sprague-Dawley rats were divided into control normal-cholesterol or high-cholesterol diet groups with or without O3FA for up to 6 weeks. NG-nitro-L-arginine methyl ester (L-NAME, 3 mg/mL), a nitric oxide synthase inhibitor, was added to the drinking water of the high-cholesterol groups during the first 2 weeks. The rats received supplementation with O3FA (5 mg/kg/day) by gavage. At 3 and 6 weeks, we measured blood lipid levels, including low-density lipoprotein (LDL), cholesterol (CHO), triglycerides (TG), and high-density lipoprotein (HDL) as atherosclerotic blood markers. The lumen of middle cerebral artery (MCA) and the thickness of the vessel wall were assessed histologically. ROS production was measured. NOX activity and mRNA and protein expression of NOX subunits (p47phox, gp91phox, p22phox, and p67phox) were measured.
Results A high-cholesterol diet exhibited a significant increase in the classic blood markers (LDL, CHO, and TG) for atherosclerosis, as well as a decrease in HDL. These markers were found to be progressively more severe with time. Additionally, increased lumen stenosis and intimal thickening were observed in the MCA for this group. Rats given O3FA demonstrated attenuation of blood lipid levels with an absence of morphological changes.O3FA significantly reduced ROS production and NOX activity in the brain. Moreover, O3FA decreased the mRNA and protein expression of the NOX subunits p47phox, gp91phox, and p67phox.
Conclusions Long-term O3FA dietary supplementation prevents the development of intracranial atherosclerosis. This O3FA effect appears to be mediated by its attenuation of NOX subunit expression and NOX activity, therefore reducing ROS production. O3FA dietary supplement shows promising results in the prevention of ICAS. 相似文献
AbstractObjective:Protein kinase B (PKB/Akt), which is phosphorylated and activated by upstream activators, exerts critical neuroprotective effects by phosphorylating downstream targets after traumatic brain injury (TBI). Studies on the regulation of Akt will be crucial for our understanding of neuronal survival. The goal of this study is to investigate the effects of carboxyl-terminal modulator protein (CTMP) on phosphorylation of Akt and neurological function in a mouse model of TBI.Methods:Traumatic brain injury in mice was performed by a controlled cortical impact device. The expression of Akt, phospho-Akt, and CTMP was examined in the injured cortices by immunohistochemistry and Western blot analysis. To determine the effects of CTMP, small interfering RNAs (siRNAs) directed against CTMP were injected in mice with TBI, and the expression of phosphorylated Akt and neurological function were evaluated.Results:Phospho-Akt significantly increased at 4 hours post-TBI in the nucleus (P < 0·01) and remained at high levels until 72 hours after TBI, as shown by Western blot analysis. In the cytosol, the expression of phospho-Akt reached its peak at 4 hours post-TBI, but decreased markedly at 24 hours and maintained below pre-TBI levels until 72 hours post-TBI. Interestingly, the expression of CTMP significantly increased 4 hours after TBI (P < 0·01) and sustained those levels until 72 hours without dramatic changes. Treatment with CTMP siRNA effectively augmented the phosphorylation of Akt and significantly improved the neurological functional recovery up to 28 days post-TBI.Conclusion:We conclude that Akt is phosphorylated and translocated to nucleus after TBI to exert neuroprotective effects. However, CTMP is simultaneously triggered to inhibit the phosphorylation of Akt. Inhibition of CTMP by siRNA improves the recovery of neurological functions after TBI. 相似文献
Lasers in Medical Science - The evaluation of pigmented lesions on tattooed skin poses a diagnostic challenge for dermatologists, as a nevus may be partially or completely obscured by tattoo... 相似文献