Prevalence of aneuploidies in products of spontaneous abortion: interest of FISH and MLPA.

Spontaneous abortion (SA) is the loss of the conceptus before 22 weeks of gestation when fetal weight is less than 500 g. The genetic etiology accounts for more than two third of SA, and autosomal aneuploidies alone account for up to 70% fetal loss. The aim of this study was to highlight the most common chromosomal causes of fetal loss. In this study, 220 products of abortion and in utero fetal death were analyzed by using FISH (AneuVysion) on interphase nuclei from chorionic villus and by using MLPA (SALSA P036, P070 and P245 kits) on DNA extracted from fetal tissues. The gestational age ranged from the 7th to the 38th week of gestation. Of a total of 151 samples analyzed by using FISH, 10 chromosomal abnormalities were observed: four trisomies 21 (one of them was mosaic), a trisomy 18, a trisomy 13, three triploidies and one monosomy X (Turner). From the additional 69 samples analyzed by using MLPA, two anomalies were found: two monosomies X (Turner). FISH and MLPA are simple, rapid and sensitive tools for the detection of chromosomal aneuploidies. Avoiding the cell culture step necessary for karyotyping, they represent very interesting alternative methods to diagnose genomic disorders in products of abortion in which poor sample quality often leads to cell culture failure.

Prevalence of anaemia in pregnant women during the last trimester: consequense for birth weight.

OBJECTIVES: Iron deficiency continues to be one of the most prevalent single-nutrient deficiencies in the world. The current study aimed to estimate the prevalence of iron deficiency anemia (IDA) among pregnant women who attend Antenatal Care Centers in Sidi Bel Abbes, Algeria. The effect of anaemia on infant birth weight was also examined. MATERIALS AND METHODS: The study was conducted during the period March-Mai, 2010 and the sample consisted of 207 pregnant women (in the third trimesters) in the age group (17-41) years. The subjects were not taking iron, folate or vitamin B12 supplements at the time of the study. Blood samples were collected from each pregnant woman and a questionnaire was completed at the time of blood collection. A series of determinations was conducted to determine hemoglobin concentration (Hb); packed cell volume (PCV); corpuscular hemoglobin concentration (MCHC), corpuscular volume (MCV). The effect of anemia on the weight of new born babies was examined by calculating the correlation coefficient of birth weight and hematological indexes. RESULTS: The overall prevalence of anemia was found to be 46.86%. According to the severity anemia was 36.08% mild, 49.48% moderate and 14.43% severe anemia. The mean values (+/- SD) of haematological indexes were as follows: Hb 9.00 +/- 1.57 g/dl; PCV 27 +/- 5.37%; mean corpuscular haemoglobin concentration (MCHC) 33.75 +/- 2.69 g/dl and mean corpuscular volume (MCV) 75.7 +/- 10.4 fl. The results have shown that 46.39% of the subjects had MCV values less than standard value of 75 fl suggesting a microcytic anemia. The mean haemoglobin concentration was 9 +/- 1.57 g/dl while the mean birth weight was 3201.54 +/- 566.71 g. There was a not significant correlation between the Hb level and the birth weight of the infants (r = 0.28, p > 0.05). The prevalence of low birth weight was 9.2%. There was no statistically significant haemoglobin concentration /foetal birth weight difference among the various hemoglobin concentration (Chi square test = 0.34, p > 0.05). CONCLUSIONS: Anemia had no significant obstetric adverse effects in our pregnant population (Fischer test = 0.06, p > 0.05). There was no statistically significant difference in mean birth weight among the various haemoglobin groups suggesting that other parameters may play important roles in influencing the birth weight than the maternal haemoglobin concentration.

[Study of the behavior of the vegetative meristem of alfa (Stipa tenacissima L.). Cytological and histological approaches]. / Etude du comportement du méristème végétatif de l'alfa (Stipa tenacissima L.). Approches cytologique et histologique.

The biological and cytological studies of the vegetative meristem of Stipa tenacissima L. gave clear indication about its structure. It was similar to what was previously described in several species. This meristem showed an axial apical zone constituted by sommital cells of both tunica and corpus, a sub-apical lateral zone, very chromophilous, representing the initial ring and a medullar meristem. The cytofluorimetric determination of DNA in interphasic nuclei of these three zones revealed that the nuclei of the apical and lateral zones were in S phase, announcing the beginning of mitosis and meaning that these zones were the centers of the foliar initiation. The medullar meristem was in dormancy: all the nuclei were in G1 phase.

Lectin-binding sites in quick-frozen, freeze-substituted extracellular matrix of rabbit corneal stroma: a comparative electron microscopic study with different embedding procedures.

The efficiency of Epon, Lowicryl K4M and LR White resins for electron microscopy was tested on the reactivity of carbohydrate residues to lectins in quick-frozen, freeze-substituted extracellular matrix of rabbit corneal stroma, without the use of any chemical fixation. Three lectins conjugated to gold particles were used in a post-embedding method: Wheat germ agglutinin, Concanavalin A and Ricinus communis agglutinin 1. Best gold-labelling was obtained with Lowicryl K4M for Wheat germ agglutinin, and with both Lowicryl K4M and Epon for Concanavalin A and Ricinus communis agglutinin 1. Tissues embedded in LR White gave less intense labelling for the three lectins used in comparison with the two other resins. This study demonstrates the crucial role of resins in the optimal preservation of biological activity of carbohydrate residues in cryotechnically-processed cornea for electron microscopy.

New method of ultrastructural localization of WGA-binding sites in the rabbit cornea using quick-frozen specimens followed by freeze-substitution.

Wheat germ agglutinin (WGA) conjugated with apo-horseradish peroxidase-gold was used as a probe for ultrastructural localization of N-acetyl-glucosamine and N-acetyl-neuraminic acid residues of glycoconjugates in posterior stroma and Descemet's membrane of rabbit corneas. Ultra-thin sections of quick-frozen, freeze-substituted, and Epon or Lowicryl K4M-embedded tissue were used. Numerous WGA-binding sites were detected in the stromal matrix and Descemet's membrane in both embedding procedures. Labelling was more intense with low-temperature embedding in Lowicryl K4M than with Epon. Gold particles preferentially labelled the major collagen fibrils of the stroma but otherwise appeared uniformly distributed over both extracellular matrices, except in some areas of the stromal matrix that were barely labelled. Frequently, the inter-particle distance of gold particles on collagen fibrils corresponded to the banding period of type I collagen fibrils, suggesting that they point out keratan sulphate proteoglycans which contain WGA-binding sites. The combination of cryotechniques and post-embedding procedures may be very effective for lectin histochemistry of the cornea and other eye tissues.