MR lymphography in patients with upper limb lymphedema: The GPS for feasibility and surgical planning for lympho-venous bypass.

BACKGROUND AND OBJECTIVES: Lymphedema is caused by insufficient lymphatic drainage leading to abnormal accumulation of interstitial fluid within soft tissues. Lympho-venous anastomosis (LVA), as a surgical option for selected patients, is widely applied. Through preoperative localization of functional lymphatics with indocyanine green, real time visualization of functioning lymphatic vessels is possible. This examination is time consuming and operator dependant and is not suitable to differentiate the ratio of fat hypertrophy to liquid edema. We investigated whether MR lymphangiography is accurate for imaging functional lymphatics and adjacent veins in arms. Furthermore, we investigated the accuracy and predictability of preoperative mapping for the feasibility of performing LVA and the preoperative decision making in lymphedema surgery. METHODS: A prospective study was performed in which 25 patients suffering from lymphedema of the upper extremity were examined. MR lymphography with contrast agent injection in a deep dermal plane was performed. RESULTS: Precise localization of lymphatic vessels crossing a vein was achieved in 18 of 25 arms. In 16 of the 18 patients in whom functional lymphatics were localized with an adjacent vein on MRI an LVA was performed successfully. CONCLUSIONS: MR lymphangiography is an accurate and reproducible method for imaging and mapping of lymphatic channels in the lymphedemateous limb.

A global downregulation of microRNAs occurs in human quiescent satellite cells during myogenesis.

During myogenesis, human satellite cells differentiate and form multinucleated myotubes, while a fraction of the human satellite cells enter quiescence. These quiescent satellite cells are able to activate, proliferate and contribute to muscle regeneration. Post-transcriptional regulation of myogenesis occurs through specific myogenic microRNAs, also known as myomiRs. Although many microRNAs are involved in myotube formation, little is known on the involvement of microRNAs in satellite cells entering quiescence. This current study aims to investigate microRNA involvement during differentiation of human satellite cells, specifically proliferating satellite cells entering quiescence. For this, clonally expanded human satellite cells were differentiated for 5 days, after which myotubes and quiescent satellite cells were separated through FACS sorting. Next, a microRNA microarray comparison of proliferating satellite cells, myotubes and quiescent satellite cells was performed and verified through qRT-PCR. We show that during human satellite cell differentiation, microRNAs are globally downregulated in quiescent satellite cells compared to proliferating satellite cells, in particular microRNA-106b, microRNA-25, microRNA-29c and microRNA-320c. Furthermore, we show that during myogenesis microRNA-1, microRNA-133, microRNA-206 and microRNA-486 are involved in myotube formation rather than satellite cells entering quiescence. Finally, we show an overall decrease in total mRNA in quiescent satellite cells, and an indication that RNaseL regulation plays a role in promoting and maintaining quiescence. Given the importance of quiescent satellite cells in skeletal muscle development and regenerative medicine, it is imperative to distinguish between myotubes and quiescent satellite cells when investigating skeletal muscle development, especially in microRNA studies, since we show that microRNAs are globally downregulated in quiescent human satellite cells.

MicroRNA-1 and microRNA-206 improve differentiation potential of human satellite cells: a novel approach for tissue engineering of skeletal muscle.

Innovative strategies based on regenerative medicine, in particular tissue engineering of skeletal muscle, are promising for treatment of patients with skeletal muscle damage. However, the efficiency of satellite cell differentiation in vitro is suboptimal. MicroRNAs are involved in the regulation of cell proliferation and differentiation. We hypothesized that transient overexpression of microRNA-1 or microRNA-206 enhances the differentiation potential of human satellite cells by downregulation quiescent satellite cell regulators, thereby increasing myogenic regulator factors. To investigate this, we isolated and cultured human satellite cells from muscle biopsies. First, through immunofluorescent analysis and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), we showed that in satellite cell cultures, low Pax7 expression is related to high MyoD expression on differentiation, and, subsequently, more extensive sarcomere formation, that is, muscle differentiation, was detected. Second, using qRT-PCR, we showed that microRNA-1 and microRNA-206 are robustly induced in differentiating satellite cells. Finally, a gain-of-function approach was used to investigate microRNA-1 and microRNA-206 potential in human satellite cells to improve differentiation potential. As a proof of concept, this was also investigated in a three-dimensional bioartificial muscle construct. After transfection with microRNA-1, the number of Pax7 expressing cells decreased compared with the microRNA-scrambled control. In differentiated satellite cell cultures transfected with either microRNA-1 or microRNA-206, the number of MyoD expressing cells increased, and α-sarcomeric actin and myosin expression increased compared with microRNA-scrambled control cultures. In addition, in a three-dimensional bioartificial muscle construct, an increase in MyoD expression occurred. Therefore, we conclude that microRNA-1 and microRNA-206 can improve human satellite cell differentiation. It represents a potential novel approach for tissue engineering of human skeletal muscle for the benefit of patients with facial paralysis.

No (wo)man is an island--the influence of physicians' personal predisposition to labia minora appearance on their clinical decision making: a cross-sectional survey.

INTRODUCTION: Physicians are increasingly presented with women requesting a labia minora reduction procedure. AIM: To assess the influencing factor of personal predisposition in general practitioners, gynecologists, and plastic surgeons to labia minora appearance in relation to their willingness to refer for, or perform, a surgical labia minora reduction. METHODS: Cross-sectional self-administered questionnaire survey. Between May 2009 and August 2009, 210 physicians were surveyed. Primary care: general practitioners working in the north of the Netherlands. Secondary care: gynecologists and plastic surgeons working in five hospitals in the north of the Netherlands. MAIN OUTCOME MEASURES: A five-point Likert scale appraisal of four pictures showing a vulva, each displaying different sizes of labia minora, indicating a physician's personal predisposition, manifesting as willingness to refer for, or perform, a labia minora reduction. RESULTS: A total of 164/210 (78.1%) physicians completed the questionnaire, consisting of 80 general practitioners, 41 gynecologists, and 43 plastic surgeons (96 males, 68 females). Ninety percent of all physicians believe, to a certain extent, that a vulva with very small labia minora represents society's ideal (2-5 on the Likert scale). More plastic surgeons regarded the picture with the largest labia minora as distasteful and unnatural, compared with general practitioners and gynecologists (P < 0.01), and regarded such a woman as a candidate for a labia minora reduction procedure (P < 0.001). Irrespective of the woman's labia minora size and the absence of physical complaints, plastic surgeons were significantly more open to performing a labia minora reduction procedure than gynecologists (P < 0.001). Male physicians were more inclined to opt for a surgical reduction procedure than their female colleagues (P < 0.01). CONCLUSIONS: The personal predisposition of physicians (taking account of their specific gender and specialty) concerning labia minora size and appearance influences their clinical decision making regarding a labia minora reduction procedure. Heightened awareness of one's personal predisposition vis-à-vis referral and willingness to operate is needed.

Hypoxia promotes proliferation of human myogenic satellite cells: a potential benefactor in tissue engineering of skeletal muscle.

Facial paralysis is a physically, psychologically, and socially disabling condition. Innovative treatment strategies based on regenerative medicine, in particular tissue engineering of skeletal muscle, are promising for treatment of patients with facial paralysis. The natural source for tissue-engineered muscle would be muscle stem cells, that is, human satellite cells (SC). In vivo, SC respond to hypoxic, ischemic muscle damage by activation, proliferation, differentiation to myotubes, and maturation to muscle fibers, while maintaining their reserve pool of SC. Therefore, our hypothesis is that hypoxia improves proliferation and differentiation of SC. During tissue engineering, a three-dimensional construct, or implanting SC in vivo, SC will encounter hypoxic environments. Thus, we set out to test our hypothesis on SC in vitro. During the first five passages, hypoxically cultured SC proliferated faster than their counterparts under normoxia. Moreover, also at higher passages, a switch from normoxia to hypoxia enhanced proliferation of SC. Hypoxia did not affect the expression of SC markers desmin and NCAM. However, the average surface expression per cell of NCAM was downregulated by hypoxia, and it also downregulated the gene expression of NCAM. The gene expression of the myogenic transcription factors PAX7, MYF5, and MYOD was upregulated by hypoxia. Moreover, gene expression of structural proteins α-sarcomeric actin, and myosins MYL1 and MYL3 was upregulated by hypoxia during differentiation. This indicates that hypoxia promotes a promyogenic shift in SC. Finally, Pax7 expression was not influenced by hypoxia and maintained in a subset of mononucleated cells, whereas these cells were devoid of structural muscle proteins. This suggests that during myogenesis in vitro, at least part of the SC adopt a quiescent, that is, reserve cells, phenotype. In conclusion, tissue engineering under hypoxic conditions would seem favorable in terms of myogenic proliferation, while maintaining the quiescent SC pool.

Current opportunities and challenges in skeletal muscle tissue engineering.

The purpose of this article is to give a concise review of the current state of the art in tissue engineering (TE) of skeletal muscle and the opportunities and challenges for future clinical applicability. The endogenous progenitor cells of skeletal muscle, i.e. satellite cells, show a high proneness to muscular differentiation, in particular exhibiting the same characteristics and function as its donor muscle. This suggests that it is important to use an appropriate progenitor cell, especially in TE facial muscles, which have a exceptional anatomical and fibre composition compared to other skeletal muscle. Muscle TE requires an instructive scaffold for structural support and to regulate the proliferation and differentiation of muscle progenitor cells. Current literature suggests that optimal scaffolding could comprise of a fibrin gel and cultured monolayers of muscle satellite cells obtained through the cell sheet technique. Tissue-engineered muscle constructs require an adequate connection to the vascular system for efficient transport of oxygen, carbon dioxide, nutrients and waste products. Finally, functional and clinically applicable muscle constructs depend on adequate neuromuscular junctions with neural cells. To reach this, it seems important to apply optimal electrical, chemotropic and mechanical stimulation during engineering and discover other factors that influence its formation. Thus, in addition to approaches for myogenesis, we discuss the current status of strategies for angiogenesis and neurogenesis of TE muscle constructs and the significance for future clinical use.

Female attitudes regarding labia minora appearance and reduction with consideration of media influence.

BACKGROUND: Labia minora (LM) appearance and reduction have gained increasing media attention in The Netherlands. OBJECTIVE: To determine the prevailing female view about LM appearance and reduction and the role of the media in shaping that view. METHODS: From October 2007 to January 2008, questionnaires designed to elicit prevailing female opinion were distributed to and completed by several groups of females. Survey participants included female medical students at the University of Groningen (n = 394; average age, 22 +/- 3 yrs); patients visiting the outpatient Department of Obstetrics and Gynaecology of the Medical Centre Leeuwarden (n = 51; average age, 40 +/- 13 yrs); and female patients visiting Heerenveen, a private clinic (n = 37; average age, 41 +/- 10 yrs). RESULTS: Most participants (95%) frequently examined their own LM. Almost half of the participants (43%) found the appearance of their LM important and 71% thought that their appearance was normal. Almost all participants (95%) have known about the possibility of LM reduction for the past 2.2 years. Most participants (78%) heard about LM reduction through a media source. Fourteen percent of the total sample found the appearance of their LM to be abnormal, 7% had considered LM reduction, and 0.42% had undergone such a procedure. CONCLUSIONS: Our survey demonstrates that the appearance of LM is important to women and that almost all women surveyed have heard about LM reduction during the past 2.2 years. Our findings probably reflect the influence of increased media attention on this issue in The Netherlands.