Tehran University Medical Journal

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Background: Umbilical cord blood gas analysis is a useful method for assessment of oxygenation and acid-base status in neonates. Severe fetal acidemia is associated with increased perinatal mortality and increased risk of subsequent impaired neurological development. Due to high percentage of C/S in our country and the effect of anesthetic medications on umbilical blood gases which can cause neonatal acidosis and hypoxemia, the study of umbilical cord blood gas in vaginal delivery versus cesarean section is mandatory.

Methods: In this cross-sectional study one hundred samples were taken from Mostafa Khomeini hospital in summer 2004. The samples were taken immediately of umbilical vein after clamping the umbilical cord and analyzed after 10 minutes. Cases were classified in to 3 groups: vaginal delivery (n=40), elective C/S under general anesthesia (n=35) and C/S under spinal anesthesia (n=25). Duration of anesthesia and its effect on blood gas and infants apgar were assessed.

Results: In the first group (vaginal delivery) mean blood gase parameters were pH=7.3064.73, pO2=25.246.87, HCO3=20.562.03, Apgar=8.820.38 and pCO2=41.826.57. In the second group (general anesthesia) mean blood gaze parameters were: pH=7.3044.73, pO2=38.7014.02, pCO2=43.265.87, HCO3=21.1113 and apgar score=8.170.7. In the third group (spinal anesthesia) mean blood gaze parameters were: pH=7.3014.50, pCO2=44.14.99, HCO3=21.382.15, pO2=26.625.5 and apgar=8.600.62. The apgar scores and pO2 demonstrated significant relationship with type of anesthesia. The apgar score was lower and pO2 was higher in C/S under general anesthesia compared with the other two groups. There was significant relationship between duration of anesthesia and umbilical pO With increasing duration of anesthesia, pO2 was reduced. Between the type of delivery and anesthesia duration with PH, pO2, pCO2 and HCO3 were not meaningful relationship (P<0.05).

Conclusion: There was no significant difference between type of delivery and umbilical blood gas parameters. Neonatal apgar score in NVD is higher than the other groups. With increasing duration of general anesthesia in C/S, umbilical po2 is reduced.

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Background: The Biophysical Profile (BPP) is a noninvasive test that predicts the presence or absence of fetal asphyxia and, ultimately, the risk of fetal death in the antenatal period. Intervention on the basis of an abnormal biophysical profile result has been reported to yield a significant reduction in prenatal mortality, and an association exists between biophysical profile scoring and a decreased cerebral palsy rate in a given population. The BPP evaluates five characteristics: fetal movement, tone, breathing, heart reactivity, and amniotic fluid (AF) volume estimation. The purpose of study was to determine whether there are different degree of acidosis at which the biophysical activity (acute marker) are affected.

Methods: In a prospective study of 140 patients undergoing cesarean section before onset of labor, the fetal biophysical profile was performed 24h before the time of cesarean and was matched with cord arterial PH that was obtained from a cord segment (10-20cm) that was double clamped after delivery of newborn. (using cord arterial PH less than 7.20 for the diagnosis of acidosis).

Results: The fetal biophysical profile was found to have a significant relationship with umbilical blood PH. The sensitivity, specificity, positive predictive value, negative predictive value of fetal biophysical profile score were: 88.9%, 88.6%, 50%, 98.1%.

Conclusion: The first manifestations of fetal acidosis are nonreactive nonstress testing and fetal breathing loss in advanced acidemia fetal movements and fetal tone are compromised. A protocol of antepartum fetal evaluation is suggested based upon the individual biophysical components rather than the score alone.

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Background: Previous studies have suggested the presence of a relationship between the increase of NRBC and the duration and intensity of asphyxia. The purpose of this study was to evaluate the relationship of fetal heart rate pattern and the number of NRBC's in umbilical cord blood sample at birth.

Methods: We enrolled 322 pregnant women with healthy, term fetuses who referred to Mirza Kouchak Khan Hospital for pregnancy termination in 2005 in a case-control study. All patients underwent continuous FHR monitoring and based on their FHR pattern, they were divided into two groups with normal FHR pattern and at least one abnormality in FHR pattern (including absence of beat to beat variability absence of proper acceleration and early, late, variable and prolonged deceleration). Samples of umbilical cord blood were evaluated for NRBC count and pH immediately after birth. The variables were compared in these two groups.

Results: The mean NRBC count was significantly higher in patients with any kind of deceleration (late, variable, early or prolonged) in comparison with controls (respectively 11.88±4.406, 8.32±4.64, 10.58±5.366, and 4.11±4.913 vs. 0.93±1.790 in controls). Furthermore the mean NRBC count was significantly higher in patients with absence of acceleration or beat to beat variability (10.73±5.07 and 13.73±3.58 vs. 1.47±2.50). There was a negative correlation between 5^th minute Apgar score and umbilical cord blood sample with mean NRBC count of umbilical cord blood sample.

Conclusion: Any abnormality in FHR pattern is associated with a significant increase in mean NRBC count of umbilical cord blood sample. There is also a significant relationship between the 5^th minute Apgar score and umbilical cord blood sample pH, and mean NRBC count in umbilical cord blood sample.

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Background: True umbilical cord knot is one of the abnormalities of the umbilical cord. Active fetal movements create cord knotting. True umbilical cord knots are rare but may be associated with fetal distress and stillbirth. True umbilical cord knots are capable of impeding blood flow to the fetus.
Case presentation: A 26-year old primigravid woman was first treated for genital herpes simplex virus (HSV type 2) at 36 weeks of gestational age. She received oral acyclovir (400 mg three times daily for 10 days). At the gestational age of 38 weeks and 5 days, fetal activity decreased and NST was nonreactive. She was delivered by cesarean section and a true umbilical cord knot was found. Four years later, in her second pregnancy, another true knot was seen.
Conclusion: Excessively long umbilical cords are more likely to be associated with true knots. Genetics has an important role in determining cord length and occurrence of true knots.

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Background: Hematopoietic stem cell transplantation (HSCT) is a therapeutic approach in treatment of hematologic malignancies and incompatibility of bone marrow. Umbilical cord blood (UCB) known as an alternative for hematopoietic stem/ progenitor cells (HPSC) for in allogenic transplantation. The main hindrance in application of HPSC derived from umbilical cord blood is the low volume of collected samples. So, ex vivo expansion of HPSCs is the useful approach to overcome this restriction. Synthetic biomaterials such as nanofibers is used to produce synthetic niches. The aim of this study was the ex vivo expansion of hematopoietic stem cells on biocompatible nanofiber scaffolds. Methods: This study was done at Tarbiat Modares University from November 2012 to June 2013 and was a research study. Umbilical cord blood CD133+ hematopoietic stem cells were separated using MidiMacs (positive selection) system by means of monocolonal antibody (microbeads) CD133. Flow cytometry was used to assess the purity of cells. Cell culture was done on plate (2 Dimensional) and fibronectin conjougated polyether sulfone nanofiber scaffold (3 Dimensional). Colony assay test was used to asses the ability of colonization of cells. Results: Cell count analysis revealed the expansion of hematopoietic stem cells in cell culture plate (2D environment) and on nanofiber scaffold (3D environment) after 2 weeks. Expansion of cells in 2D environment was greater than 3D condition. Colony assay test revealed that the colonization ability of cells decreased after 2 weeks, but this decrease was lower in scaffold culture than plate culture. Conclusion: This study demonstrated that umbilical cord blood CD133+ hematopoietic stem cells can expand on fibronectin conjugated polyether sulfone scaffold and we can use this system for expanding of cells in vitro situation.

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Background: Telomerase as an enzyme with reverse transcriptase activity has an essential role in telomere maintenance by adding a telomere repeat sequence to the 3' end of chromosome and is important for regulating of many processes in embryonic development including cell proliferation and differentiation. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) with a self-renewal capacity are cells that can differentiate into various germ layer derivatives including neural cells and cardiomyocytes, and undergo biological changes during long-term cultivation. Hence, the passage number in which the cells expanded seems to be very important for proliferating and differentiating. This study was aimed at investigating the relationship between the telomerase activity and the growth rate of (hUC-MSCs) at different passages.

Methods: This experimental study was performed in Ardabil University of Medical Sciences, Iran, from March 2014 to December 2014. The umbilical cord samples were obtained from full-term neonate hospitalized in Alavi’s Hospital in Ardabil under sterile conditions. The umbilical vessels were clear off and the small pieces of the umbilical cord were cultured in Dulbecco's modified eagle's medium (DMEM) supplemented with 20% fetal bovine serum (FBS). Then, the hUC-MSCs were harvested from passage one to three to calculate the population doubling time (PDT) and extract proteins by using CHAPS lysis buffer. Finally, the telomerase activity of the cells at different passages was measured by telomeric repeat amplification protocol (TRAP) and qRT-TRAP assays.

Results: The hUC-MSCs population doubling time at passage from 1 to 3 were calculated as the average of 54.68±1.92, 55.03±1.71 and 69.41±2.54 hours, respectively, suggesting the higher cell passage number, the more extended PDT. The threshold cycles (CTs) for the telomerase activity also showed 30.58±0.51, 27.24±0.74 and 32.13±0.75 for the cell passage from one to three, respectively, representing the significant increasing in telomerase activity at passage two compared with the other passages (P= 0.021).

Conclusion: Analysis of the growth curve, PDT determination and measurement of telomerase activity of the human umbilical cord-derived mesenchymal stem cells showed that the long-term cell culture can affect on the cell proliferation and the telomerase activity.

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Results: Injection of mesenchymal stem cells caused faster closing of the wound. The results of biometric measurement of wound skin in rats showed that skin thickness and density on days 7, 14 and 21 in the Wharton jelly mesenchymal stem cell injection group had a significant increase compared to the control group. Conclusion: The results of cell analysis showed that the isolated cells are the same as mesenchymal stem cells. The cells were of the required health and quality. Intradermal injection of mesenchymal stem cells in diabetic wound area caused faster healing in diabetic rats, according to which, such stem cells can be considered in cell therapy, especially in the field of chronic wound healing.