Evaluation of decellularized human umbilical vein (HUV) for vascular tissue engineering - comparison with endothelium-denuded HUV.

Human umbilical vessels have been recognized as a valuable and widely available resource for vascular tissue engineering. Whereas endothelium-denuded human umbilical veins (HUVs) have been successfully seeded with a patient-derived neoendothelium, decellularized vessels may have additional advantages, due to their lower antigenicity. The present study investigated the effects of three different decellularization procedures on the histological, mechanical and seeding properties of HUVs. Vessels were decellularized by detergent treatment (Triton X-100, sodium deoxycholate, IGEPAL-CA630), osmotic lysis (3 m NaCl, distilled water) and peroxyacetic acid treatment. In all cases, nuclease treatments were required to remove residual nucleic acids. Decellularization resulted in a partial loss of fibronectin and laminin staining in the subendothelial layer and affected the appearance of elastic fibres. In addition to removing residual nucleic acids, nuclease treatment weakened all stainings and substantially altered surface properties, as seen in scanning electron micrographs, indicating additional non-specific effects. Detergent treatment and osmotic lysis caused failure stresses to decrease significantly. Although conditioned medium prepared from decellularized HUV did not severely affect endothelial cell growth, cells seeded on decellularized HUV did not remain viable. This may be attributed to the partial removal of essential extracellular matrix components as well as to changes of surface properties. Therefore, decellularized HUVs appear to require additional modifications in order to support successful cell seeding. Replacing the vessels' endothelium may thus be a superior alternative to decellularization when creating tissue-engineered blood vessels with non-immunogenic luminal interfaces.

Induction of labor in twin pregnancies with oral misoprostol versus vaginal dinoprostone--is it effective and safe?

OBJECTIVE: To compare the effectiveness and safety of oral misoprostol versus vaginal dinoprostone for the induction of labor in twin pregnancies. METHODS: All twin pregnancies ≥ 34 weeks 0 days that were induced with either misoprostol or dinoprostone in St. Hedwig Hospital between 2002 and 2013 were included in this retrospective study. Length of induction, mode of delivery, maternal and neonatal outcomes were compared between the two groups. RESULTS: After identifying 186 twin mothers matching the inclusion criteria, 154 women were induced with misoprostol (group A) and 32 with dinoprostone (group B). There were no differences in demographic data between the groups. Rates of successful vaginal delivery (53.9% versus 56.3%) and length of induction to delivery (30.2 h versus 26.9 h) were also similar. There were slightly higher rates of postpartum hemorrhage in group B (16.6% versus 10.8%), but without reaching statistical significance. Neonatal outcomes regarding umbilical artery pH <7.20 and one minute Apgar also were without significant differences. CONCLUSIONS: Study data indicate that oral misoprostol and vaginal dinoprostone are similarly effective and safe for the induction of labor in twin gestations. Further trials with larger series are needed to confirm these results.

Development of endothelium-denuded human umbilical veins as living scaffolds for tissue-engineered small-calibre vascular grafts.

Tissue-engineered small-calibre vessel grafts may help to alleviate the lack of graft material for coronary and peripheral bypass grafting in an increasing number of patients. This study explored the use of endothelium-denuded human umbilical veins (HUVs) as scaffolds for vascular tissue engineering in a perfusion bioreactor. Vessel diameter (1.2 ± 0.4 mm), wall thickness (0.38 ± 0.09 mm), uniaxial ultimate failure stress (8029 ± 1714 kPa) and burst pressure (48.4 ± 20.2 kPa, range 28.4-83.9 kPa) were determined in native samples. The effects of endothelium removal from HUVs by enzymatic digestion, hypotonic lysis and dehydration were assessed. Dehydration did not significantly affect contractile function, tetrazolium dye reduction, mechanical strength and vessel structure, whereas the other methods failed in at least one of these parameters. Denudation by dehydration retained laminin, fibronectin, collagen and elastic fibres. Denuded HUVs were seeded in a perfusion bioreactor with either allogeneic HUVs endothelial cells or with saphenous vein endothelial cells harvested from patients with coronary artery disease. Seeding in a perfusion bioreactor resulted in a confluent monolayer of endothelial cells from both sources, as judged by histology and scanning electron microscopy. Seeded cells contained von Willebrand factor and CD31. In conclusion, denuded HUVs should be considered an alternative to decellularized blood vessels, as the process keeps the smooth muscle layer intact and functional, retains proteins relevant for biomechanic properties and for cell attachment and provides a suitable scaffold for seeding an autologous and flow-resistant endothelium.

Neonatal outcome using ultrathin fetoscope for laser coagulation in twin-to-twin-transfusion syndrome.

OBJECTIVE: To improve neonatal outcome using ultrathin fetoscope for laser treatment of twin-to-twin transfusion syndrome. METHODS: Retrospective cohort study of a series of 80 cases of twin-to-twin-transfusion syndrome prior to 26-weeks' gestation subjected to laser coagulation by means of a 1.0/1.2 mm fiber fetoscope with a sheath sectional area 2.65 mm(2)/3.34 mm(2) (n=27) and a 2.0 mm classic lens fetoscope with a sheath sectional area: 6.63 mm(2)/11.27 mm(2) (n=53). RESULTS: The survival rates of at least one twin in the compared groups were 94.4% (classic optic) and 100% (ultrathin optic), for both twins: 75.5% and 83.3%, respectively. By decreasing sheath diameter a pregnancy was prolonged by an average of 21.3 days (P=0.0045), with a resulting increase in the recipient's weight of 389 g (P=0.0049) and an increase in the donor's Apgar score. However, the intervention with ultrathin optic took 11 min longer (P=0.031). CONCLUSION: The reduction of the iatrogenic damage of the amniotic membrane using ultrathin fetoscope with a small sheath, significantly improves the neonatal outcome after laser treatment of twin-to-twin-transfusion syndrome. The operator should only commence working with the 1 mm fetoscope after the learning curve has been accomplished.

Advantages of human umbilical vein scaffolds derived from cesarean section vs. vaginal delivery for vascular tissue engineering.

The current study investigated whether the mode of delivery and the mode of sample collection affect the functional properties of umbilical veins as scaffolds for vascular tissue engineering purposes. Human umbilical vein (HUV) from planned cesarean-sections (PCS) showed a 1.7-fold higher maximum contraction with potassium chloride compared to spontaneous vaginal deliveries (VDs, p=0.029). The maximum contractions with histamine were 2.0- and 2.9-fold higher in the PCS and emergency c-section (ECS) groups, respectively, compared to the VD group (p=0.003). The dose-response curves of serotonin were shifted to the right approx. 6- and 5-fold in the VD group compared to PCS and ECS, respectively (p=0.009). There were no differences between the birth groups in terms of tetrazolium dye reduction, platelet adhesion, and the structural integrity. The release of the antithrombotic compound prostacyclin from vessels of the PCS and ECS groups was 6.6- and 3.5-fold higher, respectively, than in the VD group (p<0.001). There was no correlation between the duration of ischemia and any of the functional parameters. This study provides evidence that vessels obtained from PCS are to be preferred for tissue engineering purposes, as they can be harvested in a sterile fashion and show superior vasoconstrictor responses and antithrombotic properties. The data also support a once-per-day pickup schedule for umbilical cords without a deterioration of the functional properties.

Prenatal medicine related to stress and depressive reactions of pregnant women and their partners.

OBJECTIVE: Our study analyses the emotional mood of pregnant women and their partners before various prenatal diagnostic procedures (amniocentesis, ultrasound, chorion villus sampling), and their psychological stress both before and after the diagnostic procedures. METHODS: We studied 472 pregnant women and 308 partners. 88 women (18.6%) had an amniocentesis, 344 (72.8%) had ultrasound and 40 (8.5%) a chorionic villus sampling. The German version of the Center for Epidemiological Studies-Depression Scale of Hautzinger and the short questionnaire of actual situative perceived stress of Müller were used. RESULTS: Before prenatal examination, the mean level of depression and strain was equal in women and men in all groups (ultrasound, amniocentesis, chorionic villus sampling). Before the start of the prenatal examination the pregnant women had a significantly higher depressive feature on the depression-scale and significantly higher stress score than their partners. After prenatal examination the couples' stress differed significantly in the three groups for women and for men. Comparing the stress experienced before and after the prenatal diagnosis revealed both for women and men statistically significant differences. DISCUSSION: The individual experience of prenatal diagnosis is not determined by the invasivity of the procedure.

Expectations for success in fertility treatment involving assisted reproduction.

We carried out a prospective investigation recording how 115 couples estimated their chances for successful in-vitro fertilization. The couples were asked to predict the success of in-vitro fertilization on a scale ranging from 0% to 100%. The somatic findings and the social background variables (age, education, length of time of trying to get pregnant, causes of infertility and experience of treatment) were also recorded. Of these couples, 57% of the women and 61% of the men hoped for success. The expectations for success bore no relation to age, duration of infertility, education, experience with treatment or the causes of infertility.