Parthenogenic Blastocysts Derived from Cumulus-Free In Vitro Matured Human Oocytes

Approximately 20% of oocytes are classified as immature and discarded following intracytoplasmic sperm injection (ICSI) procedures. These oocytes are obtained from gonadotropin-stimulated patients, and are routinely removed from the cumulus cells which normally would mature the oocytes. Given the ready access to these human oocytes, they represent a potential resource for both clinical and basic science application. However culture conditions for the maturation of cumulus-free oocytes have not been optimized. We aimed to improve maturation conditions for cumulus-free oocytes via culture with ovarian paracrine/autocrine factors identified by single cell analysis..Human cumulus-free oocytes from hormone-stimulated cycles are capable of developing to blastocysts when cultured with ovarian factor supplementation. Our improved IVM culture conditions may be used for obtaining mature oocytes for clinical purposes and/or for derivation of embryonic stem cells following parthenogenesis or nuclear transfer

Direct comparison of distinct naive pluripotent states in human embryonic stem cells

Stem cells & developmental biolog

Unfolded protein response is an early, non-critical event during hepatic stellate cell activation.

Hepatic stellate cells activate upon liver injury and help at restoring damaged tissue by producing extracellular matrix proteins. A drastic increase in matrix proteins results in liver fibrosis and we hypothesize that this sudden increase leads to accumulation of proteins in the endoplasmic reticulum and its compensatory mechanism, the unfolded protein response. We indeed observe a very early, but transient induction of unfolded protein response genes during activation of primary mouse hepatic stellate cells in vitro and in vivo, prior to induction of classical stellate cell activation genes. This unfolded protein response does not seem sufficient to drive stellate cell activation on its own, as chemical induction of endoplasmic reticulum stress with tunicamycin in 3D cultured, quiescent stellate cells is not able to induce stellate cell activation. Inhibition of Jnk is important for the transduction of the unfolded protein response. Stellate cells isolated from Jnk knockout mice do not activate as much as their wild-type counterparts and do not have an induced expression of unfolded protein response genes. A timely termination of the unfolded protein response is essential to prevent endoplasmic reticulum stress-related apoptosis. A pathway known to be involved in this termination is the non-sense-mediated decay pathway. Non-sense-mediated decay inhibitors influence the unfolded protein response at early time points during stellate cell activation. Our data suggest that UPR in HSCs is differentially regulated between acute and chronic stages of the activation process. In conclusion, our data demonstrates that the unfolded protein response is a JNK1-dependent early event during hepatic stellate cell activation, which is counteracted by non-sense-mediated decay and is not sufficient to drive the stellate cell activation process. Therapeutic strategies based on UPR or NMD modulation might interfere with fibrosis, but will remain challenging because of the feedback mechanisms between the stress pathways

Retrospective observational study on the incidence of incisional hernias after colorectal carcinoma resection with follow-up CT scan

Incisional hernia (IH) is the most frequent complication after colorectal carcinoma (CRC) resection. The incidence depends on the method of follow-up, where ultrasound yields a significant number of additional hernias compared to clinical examination alone. Not many studies have evaluated the value of computed tomography (CT) to diagnose IH. The CorreCT study is a retrospective cohort study of IH after CRC surgery by clinical examination and by CT, as reported in the medical files. Additional independent reviewing of all CTs by two radiologists was performed. From the oncological database (2004-2008) of the hospital, 598 patients with CRC were identified. The data of 448 consecutive patients who underwent surgery were analyzed. Tumors were resected by laparotomy in 366 patients (81.7 %), by laparoscopy in 76 patients (17.0 %) and by laparotomy after conversion in 6 patients (1.3 %). A clinical follow-up by the surgeon in 282 patients (62.9 %) with a mean duration of 33 months, yielded 49 patients with IH (17.4 %). The mean time of IH diagnosis (T1) was 19 months. Only 16 patients (33 %) underwent a hernia repair. For 363 patients (81.0 %), CT follow-up was available for a mean period of 30 months. In 84 patients (23.1 %), an IH was diagnosed with a mean T1 of 21 months. The review of all CTs by two independent radiologists yielded additional IH in 19 and 21 patients, respectively, increasing the IH rate to 29.1 and 29.7 %, respectively, and with a decrease in mean T1 to 14 months. The inter-observer agreement between the radiologists had a Kappa-statistic of 0.73 (95 % CI 0.65-0.81). For those patients with disagreement between the radiologists, a final agreement was made during an additional reviewing session of both radiologists, increasing the IH rate to 35.0 %. Comparing clinical follow-up, routine CT follow-up, and reassessed CT follow-up we found a statistically significant difference between the three methods of IH detection (p < 0.0001). CT follow-up can identify significantly more IH than clinical examination alone, in particular if the radiologist focuses on IH development. Furthermore, we showed that focused CT evaluation diagnosed IH 7 months earlier than routine CT and 5 months earlier than clinical follow-up alone

Retrospective observational study on the incidence of incisional hernias after reversal of a temporary diverting ileostomy following rectal carcinoma resection with follow-up CT scans

Wounds resulting from the closure of temporary stomas have a high risk of developing an incisional hernia (IH) with incidences around 30 % in studies designed to investigate this outcome. A temporary diverting ileostomy (TDI) is often used in patients after low anterior resection (LAR) for rectal cancer. The OSTRICH study is a retrospective cohort study of rectal cancer patients who had a LAR with a reversed TDI and at least one CT scan during follow-up. Two radiologists independently evaluated all abdominal CT scans to diagnose IH at the ileostomy wound and additionally, IH at the laparotomy site. From the oncological database of rectal cancer patients treated from 2003 till 2012 (n = 317) a cohort of 153 patients that fulfilled the inclusion criteria was identified. Rectal cancer resection was performed by laparoscopy in 53 patients (34.6 %) and by laparotomy in 100 patients (65.4 %). A total of 17 IH (11.1 %) was diagnosed at the former stoma site after a mean follow-up of 2.6 years. Of these, 8 IH were in patients who had a laparoscopic LAR (15.1 %) and 9 IH in patients who had an open LAR (9.0 %) (Fisher's exact test; p = 0.28). IH on the other abdominal wall incisions was reported in 69 patients (45.1 %). Of these, 10 patients underwent laparoscopic rectal surgery (18.9 %) and in 59 patients had open rectal surgery (59.0 %) (Fisher's exact test; p < 0.0001). We found a lower number of incisional hernias (11.1 %) after reversal of ileostomies than expected from the literature. In contrast to the findings at the ileostomy site, a very high frequency of IH (59.0 %) after LAR by laparotomy was found, which was significantly higher than after laparoscopic LAR

The role of the reprogramming method and pluripotency state in gamete differentiation from patient-specific human pluripotent stem cells

The derivation of gametes from patient-specific pluripotent stem cells may provide new perspectives for genetic parenthood for patients currently facing sterility. We use current data to assess the gamete differentiation potential of patient-specific pluripotent stem cells and to determine which reprogramming strategy holds the greatest promise for future clinical applications. First, we compare the two best established somatic cell reprogramming strategies: the production of induced pluripotent stem cells (iPSC) and somatic cell nuclear transfer followed by embryonic stem cell derivation (SCNT-ESC). Recent reports have indicated that these stem cells, though displaying a similar pluripotency potential, show important differences at the epigenomic level, which may have repercussions on their applicability. By comparing data on the genetic and epigenetic stability of these cell types during derivation and in-vitro culture, we assess the reprogramming efficiency of both technologies and possible effects on the subsequent differentiation potential of these cells. Moreover, we discuss possible implications of mitochondrial heteroplasmy. We also address the ethical aspects of both cell types, as well as the safety considerations associated with clinical applications using these cells, e.g. the known genomic instability of human PSCs during long-term culture. Secondly, we discuss the role of the stem cell pluripotency state in germ cell differentiation. In mice, success in germ cell development from pluripotent stem cells could only be achieved when starting from a naive state of pluripotency. It remains to be investigated if the naive state is also crucial for germ cell differentiation in human cells and to what extent human naive pluripotency resembles the naive state in mouse