Optical tweezers use the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from tens of nanometres to tens of micrometres. Since their introduction in 1986, the optical tweezer has become an important tool for research in the fields of biology, physical chemistry and soft condensed matter physics. Recent advances promise to take optical tweezers out of the laboratory and into the mainstream of manufacturing and diagnostics; they may even become consumer products. The next generation of single-beam optical traps offers revolutionary new opportunities for fundamental and applied research.

http://physics.nyu.edu/grierlab/nreview2c/nreview2c.pdf

A revolution in optical manipulation

Guidelines and recommendations developed and/or endorsed by the American College of Rheumatology (ACR) are intended to provide guidance for particular patterns of practice and not to dictate the care of a particular patient. The ACR considers adherence to these guidelines and recommendations to be voluntary, with the ultimate determination regarding their application to be made by the physician in light of each patient’s individual circumstances. Guidelines and recommendations are intended to promote beneficial or desirable outcomes but cannot guarantee any specific outcome. Guidelines and recommendations developed or endorsed by the ACR are subject to periodic revision as warranted by the evolution of medical knowledge, technology, and practice.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.23721

American College of Rheumatology 2008 Recommendations for the Use of Nonbiologic and Biologic Disease-Modifying Antirheumatic Drugs in Rheumatoid Arthritis

Due to the comprehensive examination of 50 patients with ovarian polycystosis the authors suggested that ultrasound, laparoscopic, hormonal and endometrial parameters should be employed as diagnostic criteria.

Diagnostic criteria for polycystic ovary syndrome

Background: The suboptimal compliance to vaccinations continues to be a major public health problem.

Factors associated with

Trisomic and monosomic (aneuploid) embryos account for at least 10% of human pregnancies and, for women nearing the end of their reproductive lifespan, the incidence may exceed 50%. The errors that lead to aneuploidy almost always occur in the oocyte but, despite intensive investigation, the underlying molecular basis has remained elusive. Recent studies of humans and model organisms have shed new light on the complexity of meiotic defects, providing evidence that the age-related increase in errors in the human female is not attributable to a single factor but to an interplay between unique features of oogenesis and a host of endogenous and exogenous factors.

/pdf/human-aneuploidy-mechanisms-and-new-insights-into-an-age-old-ikk0mrjj70.pdf

Human aneuploidy: mechanisms and new insights into an age-old problem

Chromosomal abnormalities are responsible for a greatdeal of embryo wastage, which is reﬂected, at least partially,in decreased implantation and increased miscarriage inolder women. To address this problem the transfer of onlychromosomally normal embryos previously selected bypreimplantation genetic diagnosis (PGD) has been pro-posed. We designed a multi-centre in-vitro fertilization(IVF) study to compare controls and a test group thatunderwent embryo biopsy and PGD for aneuploidy.Patients were matched retrospectively, but blindly, foraverage maternal age, number of previous IVF cycles,duration of stimulation, oestradiol concentrations on dayF1, and average mature follicles. All these parameterswere similar in test and control groups. Only embryosclassiﬁed as normal for those chromosomes were trans-ferred after PGD. The results showed that the rates of fetalheart beat (FHB)/embryo transferred between the controland test groups were similar. However, spontaneous abor-tions, measured as FHB aborted/FHB detected, decreasedafter PGD (P

Positive outcome after preimplantation diagnosis of aneuploidy in human embryos

Mosaicism was studied in good quality embryos from four different centres in order to assess the effects of follicular induction and exposure to laboratory conditions on chromosomal status. The donated embryos were fully biopsied and analysed by fluorescence in-situ hybridization using probes for chromosomes X, Y, 13, 18 and 21, simultaneously. The number of abnormal cells present indicated the division at which mosaicism first occurred (4/4 cells at first division, 2/4 cells at second, 2/8 at third). The rate of mosaicism in embryos from different centres varied greatly (P < 0.001). Most of the mosaic embryos were obtained before 1991. In one clinic increased mosaicism was found in embryos obtained before 1991 when compared to embryos obtained thereafter. The results suggest that certain culture conditions and/or hormonal stimulation protocols may induce chromosomal abnormalities and partly explain differences in pregnancy rates between in-vitro fertilization centres.

Treatment-related chromosome abnormalities in human embryos.

As early as 1985, ice-free cryopreservation of mouse embryos at -196 degrees C by vitrification was reported in an attempted alternative approach to cryostorage. Since then, vitrification techniques have entered more and more the mainstream of animal reproduction as an alternative cryopreservation method to traditional slow-cooling/rapid-thaw protocols. In addition, the last few years have seen a significant resurgence of interest in the potential benefits of vitrification protocols and techniques in human-assisted reproductive technologies. The radical strategy of vitrification results in the total elimination of ice crystal formation, both within the cells being vitrified (intracellular) and in the surrounding solution (extracellular). The protocols for vitrification are very simple. They allow cells and tissue to be placed directly into the cryoprotectant and then plunged directly into liquid nitrogen. To date, however, vitrification as a cryopreservation method has had very little practical impact on human-assisted reproduction, and human preimplantation embryo vitrification is still considered to be largely experimental. Besides the inconsistent survival rates that have been reported, another problem is the wide variety of different carriers and vessels that have been used for vitrification. Second, many different vitrification solutions have been formulated, which has not helped to focus efforts on perfecting a single approach. On the other hand, the reports of successfully completed pregnancies following vitrification at all preimplantation stages is encouraging for further research and clinical implementation. Clearly, however, attention needs to be paid to the inconsistent survival rates following vitrification.

Potential Importance of Vitrification in Reproductive Medicine

https://www.fertstert.org/article/S0015-0282(98)00205-2/pdf

Birth after cryopreservation of immature oocytes with subsequent in vitro maturation

https://www.fertstert.org/article/S0015-0282(15)02037-3/pdf

Successful elective and medically indicated oocyte vitrification and warming for autologous in vitro fertilization, with predicted birth probabilities for fertility preservation according to number of cryopreserved oocytes and age at retrieval

Michael J. Tucker

Papers

Positive outcome after preimplantation diagnosis of aneuploidy in human embryos

Treatment-related chromosome abnormalities in human embryos.

Potential Importance of Vitrification in Reproductive Medicine

Birth after cryopreservation of immature oocytes with subsequent in vitro maturation

Successful elective and medically indicated oocyte vitrification and warming for autologous in vitro fertilization, with predicted birth probabilities for fertility preservation according to number of cryopreserved oocytes and age at retrieval