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Biomedical subjects

I Georgiou

Publications and source records attributed to I Georgiou.

52 records · Page 3Linked to original sources
PubMed1996

Evidence for high-risk haplotypes and (CGG)n expansion in fragile X syndrome in the Hellenic population of Greece and Cyprus.

The expansion of the trinucleotide repeat (CGG)n in successive generations through maternal meiosis is the cause of fragile X syndrome. Analysis of CA repeat polymorphisms flanking the FMR-1 gene provides evidence of a limited number of "founder" chromosomes and predisposing high-risk haplotypes related to the mutation. To investigate the origin of mutations in the fragile X syndrome in the Hellenic populations of Greece and Cyprus, we studied the alleles and haplotypes at DXS548 and FRAXAC2 loci of 16 independent fragile X and 70 normal control chromosomes. In addition, we studied 191 unrelated normal X chromosomes for the distribution and frequencies of CGG alleles. At DXS548, 6 alleles were found, 2 (194 and 196) of which were represented on fragile X chromosomes. At FRAXAC2, 6 alleles were found, 4 of which were present on fragile X chromosomes. Sixteen haplotypes were identified, but only 5 were present on fragile X chromosomes. The highest number of CGG repeats (> or = 33) were associated with haplotypes 194-147, 194-151, 194-153, and 204-155. The data provide evidence for founder chromosomes and high-risk haplotypes in the Hellenic population.

Cyprus↗
PubMed1996

Chromomycin A3-staining as an indicator of protamine deficiency and fertilization.

Mature mammalian spermatozoa have a compact and stable nuclear structure conferred by protamines instead of histones, which are present in all other cellular types. Chromomycin A3 (CMA3) is a useful tool for the detection of protamine deficiency in sperm chromatin. The purpose of this study was to correlate the percentage of spermatozoa staining positively for CMA3 with sperm parameters and in-vitro fertilization of human oocytes. Spermatozoa were collected from 56 fertile and 18 infertile men, and washed twice in PBS, fixed in two changes of methanol : acetic acid (3 : 1 v : v) spread on rinsed slides treated with APES and dried. Twenty-four of the semen samples were subjected to both Percoll and swim-up, and were stained subsequently with CMA3. CMA3-stained spermatozoa were expressed as a percentage in a count of 200 spermatozoa. A substantial variation in the percentage of CMA3-stained cells was observed in ejaculated human spermatozoa, varying between 8% and 77%. A strong negative correlation (r = -0.64, p < 0.001) was found between sperm count and the percentage of CMA3-stained spermatozoa. No correlation was found between CMA3-stained spermatozoa and their motility, while excessive sperm morphological abnormalities were related positively to CMA3-staining. Spermatozoa in samples exhibiting low (8-62%) CMA3-staining had significantly higher fertilizing rates in vitro than did samples exhibiting high (49-77%) CMA3-staining. The mean percentage of CMA3-stained spermatozoa after swim-up or Percoll preparation (26% vs 31%) did not differ significantly. These results demonstrate a close relationship between CMA3-staining, fertilization and sperm count, and suggest potential application of this marker for the prediction of sperm quality and fertilizing capacity.

Chromomycin A3↗
PubMed1995

High HbF in pregnancy is associated with the Xmn I polymorphism at the -158bp of the G gamma-globin gene.

HbF was measured in the peripheral blood of 354 women during the first trimester of pregnancy. In those (n = 6) with HbF > 3% and in 30 randomly selected pregnant women with normal HbF values, analysis of the G gamma content and the Xmn I polymorphism was performed. The frequency of the Xmn I polymorphism was significantly higher (P < 0.001) in the group with high HbF (0.67) compared to the control group (0.10). The G gamma chain content evaluation revealed a newborn ratio in all 6 high HbF subjects. Six months after delivery, HbF was measured in all women with high HbF during pregnancy, revealing normal values. These results suggest that the presence of the Xmn I polymorphism is a strong inducer for the elevation of HbF during pregnancy.

Deoxyribonucleases, Type II Site-Specific↗
PubMed1995

Amniotic fluid prealbumin as a potential marker of fetal abnormalities.

Normal amniotic fluid prealbumin (PAB) levels between 16 and 41 weeks of pregnancy are demonstrated in 175 samples from various gestational ages. PAB was measured quantitatively by immunonephelometry and qualitatively estimated by electrophoresis while total protein content was measured by colorimetry. The percent of PAB values in the total protein content is inversely correlated to the gestational age. Fetal abnormalities and abnormal conditions in pregnancy diagnosed in the second trimester and early third trimester (16-32 weeks) show significantly (p < 0.01) higher than expected PAB values (25.9 +/- 4.6 mg/l, range 19.5-35.6, n = 23) in comparison to normal fetuses and normal pregnancies of the same age (13.6 +/- 3.6 mg/l, range 4.3-19.8, n = 87). The remaining 65 samples of normal third trimester amniotic fluid were evaluated in comparison to the second trimester normal values, and inverse correlation in respect to advancing pregnancy was observed. PAB values were corrected for the total protein content and the resulting ratio had the lowest variation compared to PAB and total protein values. It is proposed that PAB, although not specific for a particular disorder, expressed as a ratio of the total protein content is a potential biochemical marker for certain fetal defects and complications of pregnancy.

Amniotic Fluid↗
PubMed1995

Gamma-chain heterogeneity in Greek (delta beta)zero-thalassemia.

A molecular and biochemical population study of (delta beta)zero thalassemia in central Greece is described. The molecular study was focused on the type of the deletion and the status of G gamma-XmnI polymorphism, whereas the biochemical approach was centered on the G gamma/A gamma ratio as well as the frequency of the A gamma T chain in the fetal hemoglobin of 19 delta beta-thalassemia heterozygotes and 3 homozygotes. This study includes individuals from the mountainous district of Epirus (northwestern Greece) where the trait was found to be concentrated along the river Arachthos. The Sicilian (delta beta)zero thalassemia deletion was found in all subjects tested by direct PCR. The levels for the G gamma-chain presented values ranging from 29 to 83% of the total gamma-chain content. Thirteen heterozygotes had the adult G gamma/A gamma ratio (mean G gamma: 35% +/- 10) of whom 10 were XmnI-negative (- / -), 6 had the newborn ratio (mean G gamma: 70% +/- 9) and were XmnI-positive, while homozygotes had equal amounts of G gamma and A gamma. Five of the 19 heterozygotes were A gamma T-positive with low levels of this A gamma-chain variant, suggesting an in-trans to the delta beta-thalassemia determinant production.

Adolescent↗
PubMed1995

Seckel syndrome in a family with three affected children and hematological manifestations associated with chromosome instability.

In the present communication we report on a family with three children affected by Seckel-syndrome with mental deficiency, microcephaly, micrognathia and severe growth deficiency. All patients had chromosome instability, which was employed for the prenatal diagnosis of a fourth fetus suspected as a potential Seckel syndrome patient, and one of them had additional hematological disorders. As this condition has been previously characterized as a Seckel syndrome subgroup we report our data concerning this distinct entity.

Abnormalities, Multiple↗
PubMed1994

Fetal globin stimulation during a short-term trial of erythropoietin in HbS/beta-thalassemia patients.

Six sickle cell/beta-thalassemia patients (3 males and 3 females) were treated with 500 U/kg body weight human recombinant erythropoietin (h-rEPO) along with 300 mg/day iron sulfate in two phases, for a period of 90 days. Fetal hemoglobin (HbF) was assayed every 2 weeks and the gamma-chain ratio at three successive intervals during the treatment. All patients showed a moderate to high increase in their HbF values (1.25- to 12-fold). The gamma-chain ratio, as determined by high performance liquid chromatography was found to be unaffected by the HbF increase. Two patients with the newborn gamma-chain ratio, responded faster to the h-rEPO treatment and achieved higher HbF values than the rest of the group. The h-rEPO treatment was very well tolerated and had a positive effect on the general clinical condition of all the patients.

Adolescent↗
PubMedDate not supplied

Increased nuchal translucency thickness in a fetus at risk for beta-thalassaemia.

In Greece and other Mediterranean countries up to 10% of the population are carriers of beta-thalassaemia and this is the most common indication for chorion villus sampling (CVS): Cytogenetic analysis of the samples is not carried out routinely, but is confined only to women aged 35 years or more. In this report we present a case that illustrates how the measurement of fetal nuchal translucency may be useful in selecting the cases where in addition to the DNA analysis for beta-thalassaemia the samples can be tested for chromosomal defects.

Adult↗
PubMedDate not supplied

Fetal heart rate following coelocentesis.

For psychological reasons, coelocentesis was performed in 20 women prior to termination of pregnancy, at 6-11 weeks of gestation. The fetal heart rate (FHR) was measured immediately before the procedure and at 1, 5, and 10 min afterward. There was no significant difference between FHR before coelocentesis compared to the values at 1 min (mean = 158, range 114-178; z = -0.629, P = 0.529), 5 min (mean = 160, range 121-179; z = -0.191, P = 0.848), or 10 min (mean 159, range 117-183; z = -0.214, P = 0.83) after the procedure. These findings suggest that coelocentesis does not have a major effect on the fetal cardiovascular system.

Female↗
PubMedDate not supplied

Effect of Percoll gradient and swim-up preparation on the chromomycin A3 staining of normal and abnormal semen samples.

The protamination of spermatozoa recovered by Percoll gradient and swim-up was investigated by means of chromomycin A3 (CMA3) staining. A total of 34 semen samples from patients undergoing IVF treatment were divided in two groups: normal (A) and oligoasthenozoospermic (B). Samples were divided in fractions, subjected to both techniques of preparation, and stained by CMA3. The percentage of CMA3 positive spermatozoa recovered by Percoll was comparable to swim-up in the normal group. In the abnormal group Percoll resulted in significantly lower CMA3 percentage. It is concluded that the degree of protamination in recovered spermatozoa is influenced by the technique of preparation.

Cell Separation↗
PubMedDate not supplied

A case of fetal intestinal tract distensions: prenatal biochemical and ultrasound evaluation.

Fetal intestinal tract abnormalities can be pregnancy complications at all maternal ages. There have been reports of ultrasound identification of these abnormalities, particularly of fetal intestinal obstructions. We report the first case to our knowledge of elevated levels of the intestinal isozyme, alkaline phosphatase, in the amniotic fluid and blood serum and also the presence of prealbumin in the amniotic fluid of a fetus with extensive intestinal distension and polyhydramnios. It was revealed that the alkaline phosphatase intestinal isozyme as well as protein electrophoresis for abnormal albumin bands in the amniotic fluid are valuable markers for the early diagnosis of the above-mentioned fetal abnormalities.

Abnormalities, Multiple↗
PubMedDate not supplied

Rapid fetal hemoglobin estimation assay during cordocentesis.

A method for rapid estimation of fetal blood content during cordocentesis is described. This procedure gives an opportunity to determine the contamination of the fetal sample by maternal blood as soon as possible. The method is based on the ability of fetal hemoglobin to resist denaturation in alkaline conditions, and can be used routinely. Fetal blood samples show a lower degradation rate (range 1.2-8.2%) compared to the maternal samples (range 25.0-52.5%). The method has the capacity to discriminate fetal and maternal samples with regard to their fetal hemoglobin content.

Cordocentesis↗
PubMedDate not supplied

Spontaneous evolution of human papillomavirus infection in the uterine cervix.

BACKGROUND: Little is known about the natural history and the malignant potential of low-grade cervical intraepithelial neoplasia associated with human papillomavirus (HPV) infection. Cervical cancer remains the second most frequent cause of death in women across the world. Epidemiologic and molecular studies have shown that human papillomavirus (HPV) is associated with cervical carcinogenesis. In this prospective study we examined the behavior of low-grade cervical intraepithelial lesions associated with HPV infection over a 6-year period. MATERIAL AND METHODS: During 1992, women with Papanicolaou smears reporting koilocytotic atypia (HPV effect) with or without grade 1 cervical intraepithelial neoplasia (HPV +/- CINI, low grade squamous intraepithelial lesions, LgSIL), along with colposcopic impression of LgSIL were included to the study. Between 1992 and 1998 all women underwent repeat Papanicolaou smears, colposcopic evaluation and HPV DNA testing every six months. HPV typing of cervical scrapes was done by PCR. RESULTS: A total of 330 women completed at least 6 years of follow up. Among women with high-risk HPV types (16/18), the presence of dysplasia (grade 1 cervical intraepithelial neoplasia) was significantly correlated with the progression of the lesion; 29% of cases with HPV + CINI (15 out of 75) progressed to more severe lesions versus only 9% of cases with HPV infection (18 out of 225), P < 0.001, chi-square test. The incidence of histologically confirmed progressive lesions was significantly greater in women with mild dysplasia (18 out of 75, 24%) compared to women without dysplasia (13 out of 255, 5%), P < 0.001, chi-square test. CONCLUSIONS: In our study HPV typing was not predictive of the evolution of low-grade intraepithelial lesions associated with HPV infection. Standard cytologic screening and colposcopy are the most effective means of monitoring low-grade lesions.

Cervix Uteri↗
PubMedDate not supplied

Oral focal epithelial hyperplasia.

Focal epithelial hyperplasia (FEH) or Heck disease, is a rare viral infection of the oral mucosa caused by HPV 13 or HPV 32. In Caucasians there have been only a few cases reported. We present the first case in Greece in a young Caucasian girl in which HPV 13 was detected with PCR analysis. The patient was successfully treated with CO2 laser.

Adolescent↗
PubMedDate not supplied

Quantitation of HBF gamma-chain types by HPLC in patients with myelodysplastic syndrome.

High levels of HbF were found in patients with myelodysplastic syndrome (MDS), as well as a possible switching of the ratio of the gamma chains from the adult to the newborn type in 25% of our patients. These abnormalities in general were not present in the parents. The possibility of having thalassemia or other hemoglobinopathies was excluded. The fetal hemoglobin percentage was quantitated by alkali denaturation of the hemolysate, and the gamma chain content was determined in blood hemolysate by HPLC following HbF isolation. A 7/3 ratio of fetal Gy/Ay was found in three patients. Since the survival of MDS patients with high HbF levels was longer than that of patients with low levels of HbF, this finding may be used as a potential prognostic factor.

Adult↗