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The main purpose of this study is to establish an effective cryopreservation protocol for the umbilical cord tissue as a source of mesenchymal stem cells (MSCs). In this context, it was aimed to use a cryoprotectant that could be an alternative to dimethyl sulfoxide (DMSO) which is commonly used despite the toxic side effects. Therefore, two different cryopreservation solutions were prepared using 10% DMSO and 10% 1,2 propanediol (PrOH). The fresh tissue group that was not performed cryopreservation was used as the control group. Following the cryopreservation step, MSCs were isolated from all groups and compared with each other to assess the efficiency of the cryopreservation solutions. The comparison was performed in terms of followings: morphology, immunophenotypes, growth kinetics, differentiation, and ultrastructural features. Based on the results, there were no significant morphological and immunophenotypic differences between the MSCs isolated from cryopreserved tissue groups and the MSCs isolated from the fresh tissue group. According to the growth kinetic analysis, the cells isolated from the PrOH group had a lower proliferation rate than the cells isolated from the fresh tissue. However, there was no significant difference between the cryopreserved groups in this respect. Osteogenic and adipogenic differentiation was observed in all groups. Upon comparison of the cryopreserved groups, PrOH group was discovered to hold a minor superiority in terms of these modes of differentiation. These results suggest that PrOH, which is considered as a cryoprotectant with low toxicity, could be used as a preferred cryoprotectant instead of DMSO concerning the process of cryopreservation of the umbilical cord.  相似文献   
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Statement of problem. The initial fit of porcelain fused to metal restorations deteriorates during the firing cycle of porcelain. Purpose. This study evaluated thermal cycling distortion of 3-unit porcelain fused to metal frameworks at different firing stages. Material and methods. A master model was designed to represent the 2 abutments of a 3-unit fixed partial denture replacing a missing mandibular molar. Standard techniques were used to fabricate 10 castings. Half of the copings were cast in a Ni-Cr alloy and the other half in a Pd-Cu alloy. Framework distortion was measured by means of inner fit changes, horizontal linear measurements of the framework length, and vertical fit changes of each retainer. Measurements were made (1) initially, (2) after degassing firing, and (3) after glaze firing. Differences between the firing cycles created distortion values of the retainers in 3 dimensions. Repeated measures ANOVA was used to analyze data statistically. Results. Measured differences between the 2 firing stages ranged from –47 to 81.7 μm. For both alloy groups, retainers showed increase in vertical gap that implied poorer vertical fit after porcelain application. Mean values of inner fit change recorded for porcelain application firing were higher in magnitude than the values of metal-conditioning firing. In addition, no statistically significant differences were found among alloy types. Conclusions. A 3-dimensional distortion was observed both in Pd-Cu and Ni-Cr frameworks during porcelain firing cycle. The distortion seen after porcelain application firing was significantly greater than that seen after metal-conditioning firing. This result can be attributed to these factors, contamination of porcelain to the inner surface of metal coping and reduction in resilience of metal. (J Prosthet Dent 1998;80:654-60.)  相似文献   
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Neuromyelitis optica (NMO, Devic’s syndrome), long considered a clinical variant of multiple sclerosis, is now regarded as a distinct disease entity. Major progress has been made in the diagnosis and treatment of NMO since aquaporin-4 antibodies (AQP4-Ab; also termed NMO-IgG) were first described in 2004. In this review, the Neuromyelitis Optica Study Group (NEMOS) summarizes recently obtained knowledge on NMO and highlights new developments in its diagnosis and treatment, based on current guidelines, the published literature and expert discussion at regular NEMOS meetings. Testing of AQP4-Ab is essential and is the most important test in the diagnostic work-up of suspected NMO, and helps to distinguish NMO from other autoimmune diseases. Furthermore, AQP4-Ab testing has expanded our knowledge of the clinical presentation of NMO spectrum disorders (NMOSD). In addition, imaging techniques, particularly magnetic resonance imaging of the brain and spinal cord, are obligatory in the diagnostic workup. It is important to note that brain lesions in NMO and NMOSD are not uncommon, do not rule out the diagnosis, and show characteristic patterns. Other imaging modalities such as optical coherence tomography are proposed as useful tools in the assessment of retinal damage. Therapy of NMO should be initiated early. Azathioprine and rituximab are suggested as first-line treatments, the latter being increasingly regarded as an established therapy with long-term efficacy and an acceptable safety profile in NMO patients. Other immunosuppressive drugs, such as methotrexate, mycophenolate mofetil and mitoxantrone, are recommended as second-line treatments. Promising new therapies are emerging in the form of anti-IL6 receptor, anti-complement or anti-AQP4-Ab biologicals.  相似文献   
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Background

The aim of this study was to present our experience with six cases of fetal intracranial hemorrhage (ICH) in terms of prenatal diagnostic features, and postnatal outcome.

Methods

The database of prenatal diagnosis unit was searched for antenatally diagnosed ICH cases. Maternal characteristics, ultrasound (US), and magnetic resonance imaging (MRI) findings, clinical course, and postnatal outcome were noted.

Results

We evaluated six consecutive cases of fetal ICH. One case was terminated at 24 weeks, and remaining five cases were delivered between 34 and 38 weeks. Five cases (5/6) had intraventricular, and one (1/6) had intraparenchymal hemorrhage. Hemorrhages were right sided in five cases (5/6), left sided in one case (1/6). Dilated and echogenic ventricular wall were the common US findings. No predisposing factor was detected in four of the cases, and intrauterine growth restriction was an underlying factor in two fetuses. Intrauterine progression of the hydrocephaly, and parenchymal thinning was seen in four cases (4/6). In three of four cases (3/4) with progressive grade 3–4 hemorrhage and hydrocephaly, postnatal outcome were dismal, and one case had mild neurological impairment at three months. In one case which had non-progressive mild ventriculomegaly, the lesion regressed after 4 weeks, and had normal short-term outcome

Conclusion

Fetal ICH can be accurately identified and categorized by antenatal sonography, and fetal MRI. Although intrauterine regression or normal short-term postnatal outcome is possible, the outcome is usually poor for fetuses with high grade and/or progressive lesions. Therefore, further studies assessing long-term postnatal outcome are needed  相似文献   
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Mesenchymal stem cells (MSCs) are considered as an important tool for regenerative medicine and experimental treatments. Unveiling the ultrastructural changes during the differentiation of MSCs might help us to understand the nature of the process and to develop novel therapeutic approaches. For this purpose, human umbilical cord (hUC) was chosen as MSC source. In the first place, MSCs were isolated from sub-amniotic, intervascular and perivascular areas of hUC by enzymatic and tissue explant method to determine the most favorable region of hUC and technique for further processing. Therefore, microscopic and growth kinetics analyses showed that there was no clear difference in the morphologies and proliferation rates among the hUC-MSC groups. Flow cytometric analysis showed that CD44 and CD90 MSC markers were highly expressed, while CD34 and CD45 hematopoietic stem cells markers were expressed at low degree. Because our preliminary results showed that there was no conspicuous superiority among the hUC-MSCs groups, whole UC was utilized as a source, and tissue explant method was applied to isolate MSCs for further differentiation analysis. At the 1st and 3rd week of osteogenic and adipogenic differentiation, ultrastructural analysis showed an increase in the number of secondary lysosomes in comparison with the undifferentiated status. Increase in the mitochondrial content was also detected at the 1st week of adipogenic differentiation. Consequently, ultrastructural changes including increase in the number of mitochondria and secondary lysosomes during the adipogenic and osteogenic differentiation could be attributed to the switch in energy metabolism of the MSCs and increment in the lysosomal activity respectively.  相似文献   
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Introduction: Although multiple sclerosis (MS) remains incurable, interferon beta (IFNβ) has been at the forefront of treatment for many years. Different formulations of IFNβ allow for different levels of exposure: low-dose/frequency with some agents, and high-dose/frequency with others.

Areas covered: This review article discusses existing and emerging efficacy and safety data for IFNβ in MS. Clinical evidence of IFNβ efficacy has been generated and accumulated over many decades. During this time, key clinical trials have demonstrated the benefits of high-dose and/or high-frequency dosing of IFNβ-1a or β-1b, compared with lower levels of exposure, on outcome measures such as relapse rates, disability progression, disease progression and magnetic resonance imaging lesion outcomes.

IFNβ therapy is well tolerated and has one of the best characterized safety profiles of all first line therapies. The overall severity of adverse events (AEs) does not appear to be affected by different IFNβ exposures. Typical AEs that patients may experience with IFNβ are mild, reversible and manageable.

Expert commentary: IFNβ is one of the best characterized treatments for MS, with a large body of clinical and real-world evidence supporting the risk-benefit profile. High-dose/frequency regimens may provide better long-term outcomes.  相似文献   

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