Evaluation of Fat Excision versus Sparing in Lower Blepharoplasty Using Orbital Gray Scale Analysis.

Orbital septum plication provides various benefits, including eliminating the necessity for a septal incision and the ability to relocate infraorbital fat in a more anatomically suitable manner. This study aimed to compare the results of traditional lower blepharoplasty with fat excision and the orbital septal plication method using orbital grey scale analysis as a new objective method for assessment. Methods: We conducted a prospective cohort study on patients with bilateral baggy lower eyelids who underwent traditional lower blepharoplasty with fat excision or fat-sparing technique using orbital septal plication. All patients were followed up closely for 1 week and then after 1, 3, and 6 months postoperatively to evaluate the study's outcomes. Results: The study was conducted using 40 patients (20 patients per group). The total (medial, central, and lateral) orbital grey scale analysis showed a significant reduction in the fat-sparing and traditional groups (P < 0.001, each). However, the percentage of reduction was significantly higher in the fat-sparing group (34.6 ± 2.9 versus 15.5 ± 3.3 in the traditional groups; P < 0.001). Conclusions: The application of the fat-sparing technique is associated with favorable cosmetic outcomes and a lower complication rate than those of the traditional technique with fat excision. Further studies with a longer duration of follow-up and a larger sample size are required to estimate the risk of recurrence and the need for a revision procedure.

Efficient tailoring of platinum nanoparticles supported on multiwalled carbon nanotubes for cancer therapy.

Aim: Therapeutically targeting cancer stem cells (CSCs), which play a role in tumor initiation and relapse, remains challenging. Materials & methods: Novel-formulated platinum nanoparticles (Pt-NPs) supported on polybenzimidazole (PBI)-functionalized polymers and multiwalled carbon nanotubes (MWCNT) were prepared and their effect on CSCs was evaluated. Results: Pt-NPs showed homogenous distribution on the surface of MWCNT/PBI composites, with very narrow particle size. MWCNT/PBI/Pt-NPs resulted in a dramatic decrease in the proliferation rate of CSCs but not bone marrow mesenchymal stem cells (BM-MSCs). Quantitative gene expression analysis revealed that MWCNT/PBI/Pt had a significant inhibitory effect on the epithelial-mesenchymal transition and cell cycle markers of CSCs. Conclusion: MWCNT/PBI/Pt exhibited a specific cytotoxic effect on breast CSCs but not on adult stem cells.

Characterization of embryonic cells obtained from multifetal reduction.

The multifetal reduction (MFR) procedure is usually reserved for high-order multiple pregnancies, and aspirated tissues are typically discarded. In this study, cells obtained from MFR tissue (termed multifetal reduction embryonic cells (MFR-ECs)), were characterized in vitro by genotypic and phenotypic analyses and tested in vivo by injection under the kidney capsule of nude mice. MFR-ECs were highly proliferative in culture and showed a normal karyotype by microarray CGH. Immunohistochemical analysis at day zero showed positive focal staining for desmin, S-100 protein, synaptophysin and chromogranin. Histology examination showed a mixture of cells from the three germ layers at different stages of differentiation. Markers of these stages included important developmental transcription factors, such as beta three-tubulin (ectoderm), paired box 6 (ectoderm) and alpha-smooth muscle actin (mesoderm). Quantitative polymerase chain reaction (qPCR) showed down-regulation of the mRNAs of cancer-related genes such as TP53. In vivo transplantation in nude mice showed a typical hyaline cartilage plate and no teratoma formation. Thus, MFR-ECs represent a rich, unique source for studying stem cell development, embryogenesis and cell differentiation.

Tissue regeneration: Impact of sleep on stem cell regenerative capacity.

The circadian rhythm orchestrates many cellular functions, such as cell division, cell migration, metabolism and numerous intracellular biological processes. The physiological changes during sleep are believed to promote a suitable microenvironment for stem cells to proliferate, migrate and differentiate. These effects are mediated either directly by circadian clock genes or indirectly via hormones and cytokines. Hormones, such as melatonin and cortisol, are secreted in response to neural optic signals and act in harmony to regulate many biological functions during sleep. Herein, we correlate the effects of the main circadian genes on the expression of certain stem cell genes responsible for the regeneration of different tissues, including bone, cartilage, skin, and intestine. We also review the effects of different hormones and cytokines on stem cell activation or suppression and their relationship to the day/night cycle. The correlation of circadian rhythm with tissue regeneration could have implications in understanding the biology of sleep and tissue regeneration and in enhancing the efficacy and timing of surgical procedures.

Telomerase reverse transcriptase coordinates with the epithelial-to-mesenchymal transition through a feedback loop to define properties of breast cancer stem cells.

Telomerase and its core component, telomerase reverse transcriptase (hTERT), are critical for stem cell compartment integrity. Normal adult stem cells have the longest telomeres in a given tissue, a property mediated by high hTERT expression and high telomerase enzymatic activity. In contrast, cancer stem cells (CSCs) have short telomeres despite high expression of hTERT, indicating that the role of hTERT in CSCs is not limited to telomere elongation and/or maintenance. The function of hTERT in CSCs remains poorly understood. Here, we knocked down hTERT expression in CSCs and observed a morphological shift to a more epithelial phenotype, suggesting a role for hTERT in the epithelial-to-mesenchymal transition (EMT) of CSCs. Therefore, in this study, we systematically explored the relationship between hTERT and EMT and identified a reciprocal, bi-directional feedback loop between hTERT and EMT in CSCs. We found that hTERT expression is mutually exclusive to the mesenchymal phenotype and that, reciprocally, loss of the mesenchymal phenotype represses hTERT expression. We also showed that hTERT plays a critical role in the expression of key CSC markers and nuclear ß-catenin localization, increases the percentage of cells with side-population properties, and upregulates the CD133 expression. hTERT also promotes chemoresistance properties, tumorsphere formation and other important functional CSC properties. Subsequently, hTERT knockdown leads to the loss of the above advantages, indicating a loss of CSC properties. Our findings suggest that targeting hTERT might improve CSCs elimination by transitioning them from the aggressive mesenchymal state to a more steady epithelial state, thereby preventing cancer progression.

Cancer cell-soluble factors reprogram mesenchymal stromal cells to slow cycling, chemoresistant cells with a more stem-like state.

BACKGROUND: Mesenchymal stem cells (MSCs) play different roles in modulating tumor progression, growth, and metastasis. MSCs are recruited to the tumor site in large numbers and subsequently have an important microenvironmental role in modulating tumor progression and drug sensitivity. However, the effect of the tumor microenvironment on MSC plasticity remains poorly understood. Herein, we report a paracrine effect of cancer cells, in which they secrete soluble factors that promote a more stem-like state in bone marrow mesenchymal stem cells (BM-MSCs). METHODS: The effect of soluble factors secreted from MCF7, Hela, and HepG2 cancer cell lines on BM-MSCs was assessed using a Transwell indirect coculture system. After 5 days of coculture, BM-MSCs were characterized by flow cytometry for surface marker expression, by qPCR for gene expression profile, and by confocal immunofluorescence for marker expression. We then measured the sensitivity of cocultured BM-MSCs to chemotherapeutic agents, their cell cycle profile, and their response to DNA damage. The sphere formation, invasive properties, and in-vivo performance of BM-MSCs after coculture with cancer cells were also measured. RESULTS: Indirect coculture of cancer cells and BM-MSCs, without direct cell contact, generated slow cycling, chemoresistant spheroid stem cells that highly expressed markers of pluripotency, cancer cells, and cancer stem cells (CSCs). They also displayed properties of a side population and enhanced sphere formation in culture. Accordingly, these cells were termed cancer-induced stem cells (CiSCs). CiSCs showed a more mesenchymal phenotype that was further augmented upon TGF-ß stimulation and demonstrated a high expression of the ß-catenin pathway and ALDH1A1. CONCLUSIONS: These findings demonstrate that MSCs, recruited to the tumor microenvironment in large numbers, may display cellular plasticity, acquire a more stem-like state, and acquire some properties of CSCs upon exposure to cancer cell-secreted factors. These acquired characteristics may contribute to tumor progression, survival, and metastasis. Our findings provide new insights into the interactions between MSCs and cancer cells, with the potential to identify novel molecular targets for cancer therapy.

Clinical Efficacy of Stem Cell Therapy for Diabetes Mellitus: A Meta-Analysis.

BACKGROUND: Stem cell therapy is a promising therapeutic modality for advanced diabetes mellitus (DM). This study presents a meta-analysis of relevant clinical trials to determine the efficacy of stem cell therapy in DM. We aim to critically evaluate and synthesize clinical evidence on the safety and efficiency of different types of stem cell therapy for both T1DM and T2DM. METHODS AND FINDINGS: We pooled participant-level data from twenty-two eligible clinical trials that satisfied our inclusion criteria, with a total of 524 patients. There were significant differences in the outcome based on the type and source of the infused cells. Out of all T1DM patients who received CD34+ hematopoietic stem cell (HSC) infusion, 58.9% became insulin independent for a mean period of 16 months, whereas the results were uniformly negative in patients who received umbilical cord blood (UCB). Infusion of umbilical cord mesenchymal stem cells (UC-MSCs) provided significantly beneficial outcome in T1DM, when compared to bone-marrow mesenchymal stem cells (BM-MSCs) (P<0.0001 and P = 0.1557). Administration of stem cell therapy early after DM diagnosis was more effective than intervention at later stages (relative risk = 2.0, P = 0.0008). Adverse effects were observed in only 21.72% of both T1DM and T2DM stem cell recipients with no reported mortality. Out of all poor responders, 79.5% were diagnosed with diabetic ketoacidosis. CONCLUSIONS: Stem cell transplantation can represent a safe and effective treatment for selected patients with DM. In this cohort of trials, the best therapeutic outcome was achieved with CD34+ HSC therapy for T1DM, while the poorest outcome was observed with HUCB for T1DM. Diabetic ketoacidosis impedes therapeutic efficacy.

The cell cycle as a brake for ß-cell regeneration from embryonic stem cells.

The generation of insulin-producing ß cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic ß cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle machinery. Both ß cells and ES cells possess unique cell cycle machinery yet with significant contrasts. In this review, we compare the cell cycle control mechanisms in both ES cells and ß cells, and highlight the fundamental differences between pluripotent cells of embryonic origin and differentiated ß cells. Through critical analysis of the differences of the cell cycle between these two cell types, we propose that the cell cycle of ES cells may act as a brake for ß-cell regeneration. Based on these differences, we discuss the potential of modulating the cell cycle of ES cells for the large-scale generation of functionally mature ß cells in vitro. Further understanding of the factors that modulate the ES cell cycle will lead to new approaches to enhance the production of functional mature insulin-producing cells, and yield a reliable system to generate bona fide ß cells in vitro.

Mesenchymal stem cells growth and proliferation enhancement using PLA vs PCL based nanofibrous scaffolds.

Electrospinning of polymers is the most commonly used technique for nanofiber fabrication. polylactic acid (PLA) and polycaprolactone (PCL) have been shown to be ideal for nanofiber preparation in various biomedical applications, due to characteristics such as biodegradablity and their ability to promote the cell growth, similar to native tissues. The aim of this study was to develop biocompatible and biodegradable PLA and PCL-based nanofibrous scaffolds for enhancing stem cell growth and proliferation. The scaffolds were prepared by electrospinning, and their physicochemical properties were studied using Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The surface morphology of the developed scaffolds was determined using scanning electron microscopy (SEM). Mesenchymal stem cells (MSCs), derived from both adipose tissue and bone marrow, were seeded onto the prepared nanofibrous scaffolds. The effect of scaffold type, and structural characteristics on survival and proliferation of MSCs were evaluated. Our results show that after full physicochemical characterization of PCL and PLA nanofibrous scaffolds both were safe and non-toxic to the evaluated cells and both scaffolds supported cell attachment and proliferation of bone marrow and adipose tissue-derived MSCs.

Adipose Stem Cells Display Higher Regenerative Capacities and More Adaptable Electro-Kinetic Properties Compared to Bone Marrow-Derived Mesenchymal Stromal Cells.

Adipose stem cells (ASCs) have recently emerged as a more viable source for clinical applications, compared to bone-marrow mesenchymal stromal cells (BM-MSCs) because of their abundance and easy access. In this study we evaluated the regenerative potency of ASCs compared to BM-MSCs. Furthermore, we compared the dielectric and electro-kinetic properties of both types of cells using a novel Dielectrophoresis (DEP) microfluidic platform based on a printed circuit board (PCB) technology. Our data show that ASCs were more effective than BM-MSCs in promoting neovascularization in an animal model of hind-limb ischemia. When compared to BM-MSCs, ASCs displayed higher resistance to hypoxia-induced apoptosis, and to oxidative stress-induced senescence, and showed more potent proangiogenic activity. mRNA expression analysis showed that ASCs had a higher expression of Oct4 and VEGF than BM-MSCs. Furthermore, ASCs showed a remarkably higher telomerase activity. Analysis of the electro-kinetic properties showed that ASCs displayed different traveling wave velocity and rotational speed compared to BM-MSCs. Interestingly, ASCs seem to develop an adaptive response when exposed to repeated electric field stimulation. These data provide new insights into the physiology of ASCs, and evidence to their potential superior potency compared to marrow MSCs as a source of stem cells.

Programmed death-1/programmed death-L1 signaling pathway and its blockade in hepatitis C virus immunotherapy.

Chronic hepatitis C virus (HCV) infection is a public health issue that often progresses to life-threatening complications, including liver cirrhosis, fibrosis, and hepatocellular carcinoma. Impaired immune responses to HCV are key features of chronic HCV infection. Therefore, intervention strategies usually involve enhancing the immune responses against HCV. Cytotoxic CD8(+) T lymphocytes (CTLs) play a critical role in the control of HCV infection. However, their cytolytic function can be impaired by the expression of co-inhibitory molecules. Programmed death-1 (PD-1) receptor and its ligand PD-L1 function in a T cell co-inhibitory pathway, which either blocks the function of CTLs or the differentiation of CD8(+) T cells. During chronic HCV infection, the immune inhibitory receptor PD-1 is upregulated on dysfunctional HCV-specific CD8(+) T cells. As such, blockade of the PD-1/PD-L1 pathway in these CD8(+) T cells might restore their functional capabilities. Indeed, clinical trials using therapies to block this pathway have shown promise in the fostering of anti-HCV immunity. Understanding how chronic HCV infection induces upregulation of PD-1 on HCV specific T cells and how the PD-1/PD-L1 interaction develops HCV specific T cell dysfunction will accelerate the development of an efficacious prophylactic and therapeutic vaccination against chronic HCV infections, which will significantly improve HCV treatments and patient survival. In this review, we discuss the relationship between PD-1 expression and clinical responses and the potential use of PD-1 blockade for anti-HCV therapy.

Regulators of pluripotency and their implications in regenerative medicine.

The ultimate goal of regenerative medicine is to replace damaged tissues with new functioning ones. This can potentially be accomplished by stem cell transplantation. While stem cell transplantation for blood diseases has been increasingly successful, widespread application of stem cell therapy in the clinic has shown limited results. Despite successful efforts to refine existing methodologies and to develop better ones for reprogramming, clinical application of stem cell therapy suffers from issues related to the safety of the transplanted cells, as well as the low efficiency of reprogramming technology. Better understanding of the underlying mechanism(s) involved in pluripotency should accelerate the clinical application of stem cell transplantation for regenerative purposes. This review outlines the main decision-making factors involved in pluripotency, focusing on the role of microRNAs, epigenetic modification, signaling pathways, and toll-like receptors. Of special interest is the role of toll-like receptors in pluripotency, where emerging data indicate that the innate immune system plays a vital role in reprogramming. Based on these data, we propose that nongenetic mechanisms for reprogramming provide a novel and perhaps an essential strategy to accelerate application of regenerative medicine in the clinic.

Immunobiology and signaling pathways of cancer stem cells: implication for cancer therapy.

Cancer stem cells (CSCs) need to survive cancer treatments with a specific end goal to provide new, more differentiated, metastatic-prone cancerous cells. This happens through diverse signals delivered within the tumor microenvironment where ample evidence indicates that altered developmental signaling pathways play an essential role in maintaining CSCs and accordingly the survival and the progression of the tumor itself. This review summarizes findings on the immunobiological properties of CSCs as compared with cancerous non-stem cells involving the expression of immunological molecules, cytokines and tumor antigens as well as the roles of the Notch, Wnt and Hedgehog pathways in the brain, breast and colon CSCs. We concluded that if CSCs are the main driving force behind tumor support and growth then understanding the molecular mechanisms and the immunological properties directing these cells for immune tolerance is of great clinical significance. Such knowledge will contribute to designing better targeted therapies that could prevent tumor recurrence and accordingly significantly improve cancer treatments and patient survival.

Biogenic amine contents in selected Egyptian fermented foods as determined by ion-exchange chromatography.

Biogenic amines in foods may pose a public health problem. Therefore, histamine, tyramine, putrescine, cadaverine, spermine, and spermidine concentrations were measured in selected food items commonly consumed in Egypt. Foods examined were dairy products (blue cheese and Mesh cheese), meats (fermented and smoked cooked sausage), and fish (smoked and salted fermented fish [Feseekh], salted sardines, and anchovies). Egyptian fermented sausage had the highest concentration of total biogenic amines (2,482 mg/kg), followed by Mesh cheese (2,118 mg/kg) and blue cheese (2,084 mg/kg). The lowest concentration was found in smoked cooked sausage (111 mg/kg). Histamine was found at a high level (521 mg/kg) in Feseekh, and tyramine was highest (2,010 mg/kg) in blue cheese. These results indicate that some traditional Egyptian foods may pose a health risk due to the concentration of biogenic amines, especially histamine.