Cord Blood Karyotyping: A Safe and Non-Invasive Method for Postnatal Testing of Assisted Reproductive Technology Children

Background:

To verify the hypothesis that the incidence of chromosomal abnormalities increases in babies conceived by different assisted reproduction procedures. The availability of the umbilical cord blood encouraged us to study this hypothesis via this method.

Materials and Methods:

This is a descriptive study, umbilical cord blood samples of assisted reproductive technology (ART) children were analyzed with standard cytogenetic techniques (G banding). Karyotyping was possible in 109 cases.

Results:

The number of abnormal cases was four (3.7%), among which, three cases (2.8%) were inherited and only 1 case (0.9%) was a de novo translocation. In total, the incidence of de novo chromosomal abnormalities was in the range observed in all live births in the general population (0.7-1%).

Conclusion:

No significant difference in the incidence of chromosomal abnormality was found between ART and naturally conceived babies. To date, several studies have examined the medical and developmental outcome of ART children and still have not reached a definite conclusion. Genetic counseling is recommended as an integral part of planning of treatment strategies for couples wishing to undergo ART.

Generation of Rat Embryonic Germ Cells via Inhibition of TGFß and MEK Pathways

OBJECTIVE

Embryonic germ (EG) cells are the results of reprogramming primordial germ cells (PGC) in vitro. Studying these cells can be of benefit in determining the mechanism by which specialized cells acquire pluripotency. Therefore in the current study we have tried to derive rat EG cells with inhibition of transforming growth factor-β (TGFβ) and mitogen-activated protein kinase kinase (MEK) signaling pathways.

MATERIALS AND METHODS

In this experimental study, rat PGCs were cultured under feeder free condition with two small molecules that inhibited the above mentioned pathways. Under this condition only two-day presence of stem cell factor (SCF) as a survival factor was applied for PGC reprogramming. Pluripotency of the resultant EG cells were further confirmed by immunofluorescent staining, directed differentiation ability to neural and cardiac cells, and their contribution to teratoma formation as well. Moreover, chromosomal stability of two different EG cells were assessed through G-banding technique.

RESULTS

Formerly, derivation of rat EG cells were observed solely in the presence of glycogen synthase kinase-3 (GSK3β) and MEK pathway inhibitors. Due to some drawbacks of inhibiting GSK3β molecules such as increases in chromosomal aberrations, in the present study we have attempted to assess a feeder-free protocol that derives EG cells by the simultaneous suppression of TGFβ signaling and the MEK pathway. We have shown that rat EG cells could be generated in the presence of two inhibitors that suppressed the above mentioned pathways. Of note, inhibition of TGFβ instead of GSK3β significantly maintained chromosomal integrity. The resultant EG cells demonstrated the hallmarks of pluripotency in protein expression level and also showed in vivo and in vitro differentiation capacities.

CONCLUSION

Rat EG cells with higher karyotype stability establish from PGCs by inhibiting TGFβ and MEK signaling pathways.

Survey of early complications of primary skin graft and secondary skin graft (delayed) surgery after resection of burn waste in hospitalized burn patients

INTRODUCTION

Burning is the second most common cause of home injuries in Iran that is often the cause of conflicts between children and young adults. Burning can lead to early and late complications that scar and contracture are the most common. Burn waste treatment is done by two methods: excision and then skin graft after the formation of granulation tissue; and excision and graft simultaneously that in this study, these two methods are compared.

METHODS

This was performed as a quasi-experimental analysis and retrospective study on all patients who were hospitalized for burn scar. All patients who have associated with weak eningimmune diseases such as diabetes, acquired immunodeficiency or congenital, taking steroids and patients undergoing chemotherapy etc. are excluded. The method of grafting in patients is primary graft procedure that was compared with patients who are treated using secondary graft. Data collected through review of patients' hospital and clinic chart.

RESULTS

The mean burn percentage in the primary repair group was 14.4% and in the delayed repair group was 16.6%, respectively. The incidence of hematoma in both groups was zero. Skin necrosis and graft rejection and infection in the primary repair group was in 3.7% of patients and in the delayed repair group was in 1.2% of cases (P=0.5) CONCLUSION: Based on the findings of this study, no difference was observed between the two methods of excision and primary graft with delayed graft in the incidence of graft rejection. Due to the shorter treatment of primary graft and patient satisfaction and also according to the findings of this study excision and primary graft method seems appropriate method for treating old waste burning. 

Production of transgenic goats expressing human coagulation factor IX in the mammary glands after nuclear transfer using transfected fetal fibroblast cells

There are growing numbers of recombinant proteins that have been expressed in milk. Thus one can consider the placement of any gene of interest under the control of the regulatory elements of a milk protein gene in a dairy farm animal. Among the transgene introducing techniques, only nuclear transfer (NT) allows 100 % efficiency and bypasses the mosaicism associated with counterpart techniques. In this study, in an attempt to produce a transgenic goat carrying the human coagulation factor IX (hFIX) transgene, goat fetal fibroblasts were electroporated with a linearized marker-free construct in which the transgene was juxtaposed to β-casein promoter designed to secret the recombinant protein in goat milk. Two different lines of transfected cells were used as donors for NT to enucleated oocytes. Two transgenic goats were liveborn. DNA sequencing of the corresponding transgene locus confirmed authenticity of the cloning procedure and the complementary experiments on the whey demonstrated expression of human factor IX in the milk of transgenic goats. In conclusion, our study has provided the groundwork for a prosperous and promising approach for large-scale production and therapeutic application of hFIX expressed in transgenic goats.

A new efficient protocol for directed differentiation of retinal pigmented epithelial cells from normal and retinal disease induced pluripotent stem cells

We describe a new, efficient protocol that involves the serial addition of noggin, basic fibroblast growth factor (bFGF), retinoic acid, and sonic hedgehog (Shh) for the differentiation of human induced pluripotent stem cells (hiPSC) to retinal pigmented epithelium (RPE) in a serum- and feeder-free adherent condition. hiPSC-RPE cells exhibited RPE morphology and specific molecular markers. Additionally, several hiPSC lines were generated from retinal-specific patients with Leber's congenital amaurosis, Usher syndrome, two patients with retinitis pigmentosa, and a patient with Leber's hereditary optic neuropathy. The RPE cells generated from these disease-specific hiPSCs expressed specific markers by the same RPE lineage-directed differentiation protocol. These findings indicate a new short-term, simple, and efficient protocol for differentiation of hiPSCs to RPE cells. Such specific retinal disease-specific hiPSCs offer an unprecedented opportunity to recapitulate normal and pathologic formation of human retinal cells in vitro, thereby enabling pharmaceutical screening, and potentially autologous cell replacement therapies for retinal diseases.

Long-term self-renewable feeder-free human induced pluripotent stem cell-derived neural progenitors

Human induced pluripotent stem cells (hiPSCs) have led to an important revolution in stem cell research and regenerative medicine. To create patient-specific neural progenitors (NPs), we have established a homogenous, expandable, and self-renewable population of multipotent NPs from hiPSCs, using an adherent system and defined medium supplemented with a combination of factors. The established hiPSC-NPs highly expressed Nestin and Sox1. These NPs were continuously propagated for ~1 year without losing their potential to generate astrocytes, oligodendrocytes, and functional neurons and maintained a stable chromosome number. Voltage clamp analysis revealed outward potassium currents in hiPSC-NPs. The self-renewal characteristic of the NPs was demonstrated by a symmetrical mode of Nestin-positive cell division. Additionally, these hiPSC-NPs can be easily frozen and thawed in the presence of Rho-associated kinase (ROCK) inhibitor without losing their proliferation, karyotype stability, and developmental potential. The characteristics of our generated hiPSC-NPs provide the opportunity to use patient-specific or ready-to-use hiPSC-NPs in future biomedical applications.