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Biomedical subjects

E Koumantakis

Publications and source records attributed to E Koumantakis.

At least 37 records · Page 2Linked to original sources
PubMed2000

Human papillomavirus infection of non-melanoma skin cancers in immunocompetent hosts.

Human papilloma viruses (HPVs) consist of more than 70 different types and are known to be associated with numerous malignant tumors, including carcinomas of the mucosal and cutaneous epithelium. Non-melanoma skin carcinoma (NMSC) is the most frequently occurring malignancy worldwide in the Caucasian population. Most studies examining the involvement of papillomaviruses in the development of cutaneous carcinomas have been performed on lesions from patients with epidermodysplasia verruciformis or from immunosuppressed patients. Our specimens were obtained from 108 immunocompetent patients with benign and malignant skin lesions, and HPVs were detected in 27%. HPV 8 and HPV 18 were the most frequent types (62 and 48%, respectively). Our results suggest that HPVs, particularly the oncogenic potential of certain types such as HPV 8, 18, and 5 could contribute to the development of NMSCs.

Basal Cell Carcinoma↗
PubMed2000

Th1- and Th2-type lymphokine-assisted induction and release of chemokine receptors from primary human trophoblast cells.

Chemokine receptors (CCRs) have been demonstrated to facilitate the entry of HIV in different cell types of infected individuals, including CD4(+) T cells and dendritic cells. The natural or inducible expression of CCRs on trophoblast cells could provide a valid mechanism for the in utero transmission of HIV from mother to fetus. Because of the rapid turnover of these receptors, we attempted to define the natural and inducible expression of surface CCR3 and CXCR4 on primary human trophoblasts during short periods of cell culture. In the absence of any external stimulus the expression of CCR3 and CXCR4 varied from 1% to 24%. Kinetic experiments show that the levels of both CCR3 and CXCR4 reach a peak of expression after 6 h of culture, whereas by 24 h they have almost disappeared. In the presence of IFN-gamma, CCR3 is showing an increasing pattern of expression after 4 h of incubation, reaching highest levels after 24 h of culture, whereas CXCR4 is kept at lower levels as compared with nontreated cells. Furthermore, in the presence of IL-4, CCR3 expression declines from 2 to 8 h of culture to increase again at 24 h, where 50% of the cell population is expressing the receptors. Under the IL-4 stimulus, CXCR4 shows a peak of expression at 8 h of culture. An interesting feature of this study is that we were able to detect soluble CCR activity in the culture supernatants of trophoblast cells, which followed an inverse pattern of this of surface expression. Thus, the inability of many laboratories to detect high levels of CCRs in placentae of HIV infected mothers may be due on these fast turnover of these receptors, which by the assaying time have either been released in the culture medium or been internalized to the cell.

Cells, Cultured↗
PubMed2000

Factors that may predispose to rupture of tubal ectopic pregnancy.

OBJECTIVE: The purpose of our study was to evaluate factors that may predispose to rupture of tubal ectopic pregnancy. The study included 99 cases of ectopic pregnancies that were treated during the 5-year period 1992-1996. RESULTS: It was found that: (1) tubal rupture is encountered more often in women with no history of ectopic pregnancy and in those who have full-term pregnancy, suggesting that ectopic pregnancy is less suspected in these women; (2) tubal rupture is encountered less often in lower age ectopic pregnancy; and (3) serum beta-hCG level does not predict tubal rupture. CONCLUSIONS: Rupture of the tube is more often observed in women with a history of ectopic pregnancy and in women with full-term pregnancy. Such observations suggest that ectopic pregnancy is less suspect in these cases.

Adult↗
PubMed2000

Cervical cancer screening in Greece.

The aim of this study was to describe the state of the art in cervical cancer screening in Greece by presenting the two regionally organised screening programmes that currently operate in the country. Both programmes were initiated in 1991 and are partly funded by the European Union. The Ormylia screening programme covers the population of Halkidiki (Northern Greece), a predominantly rural area. The second programme covers the regions of Messinia and Ilia (Southern Greece). Both programmes are targeted at women aged 25-64 years of age and a Papanicolaou (Pap) smear test is recommended every 2-3 years. Electoral and municipal registries are used to identify the target population and personal invitations are sent to the eligible women in the screening programme. The Ormylia programme is based at the Centre 'Our Lady Who Loves Mankind', whereas mobile units are used by the Messinia and Ilia programme. Slide reading for the Ormylia programme is performed in the cytology laboratory of Alexandra Hospital in Athens and epidemiological support is provided by the Department of Hygiene and Epidemiology (Medical School, University of Athens). A specifically designed database is used for data recording. Over 80% of the target population in the region have already been screened. Communication of results is by means of a personal letter upon a negative result and in person upon a suspicious result. Quality assurance in both programmes is based on the European protocol. These two programmes are the sole organised cervical cancer screening activities in Greece in the absence of a national programme. They employ well-trained personnel, they use modern equipment and have strict quality assurance procedures.

Adult↗
PubMed2000

Corticotrophin-releasing hormone (CRH) interacts with inflammatory prostaglandins and interleukins and affects the decidualization of human endometrial stroma.

The hypothalamic neuropeptide, corticotrophin-releasing hormone (CRH), which is also produced by human endometrium, has been shown to induce its decidualization in vitro. This process, induced mainly by progesterone, has characteristics of an aseptic inflammatory reaction, and is modulated by locally produced pro-inflammatory factors. In humans, prostaglandin E(2) (PGE(2)) enhances while interleukin (IL)-1 inhibits the decidualizing effect of progesterone. The aim of the present work was to test the hypothesis that CRH might affect the decidualization of human endometrium interacting with these factors. Therefore, we studied its effects on the production of pro-inflammatory interleukins IL-1, IL-6 and of PGE(2) from human endometrial stromal cells in primary culture. The results strongly suggest that CRH decidualizes stromal cells, as judged by the appearance of cytokeratins and the production of prolactin, two established markers of decidualization. In parallel to its effect on decidualization, CRH also decreased the production of PGE(2), while it increased the production of IL-1 and IL-6. Exposure of endometrial stromal cells to IL-6 also caused decidualization. The data presented here suggest that endometrial CRH regulates the production of local modulators of decidualization, i.e. PGE(2), IL-1 and IL-6. We postulate that, through the regulation of these factors, CRH acts as a local fine-tuner of decidualization initiated by progesterone.

Cell Differentiation↗
PubMed2000

Nitric oxide production by pre-implantation embryos in response to embryotoxic factors.

In this report, we examined whether nitric oxide (NO) is involved in early embryo death. We have chosen various experimentally defined embryotoxic stimuli in mice and determined their ability to induce NO production by 2-cell stage embryos. The embryotoxic factors used were interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), 5-Azacytidine (5-AzaC) and the murine embryotoxic antibody DF4. We showed that in all cases the embryotoxic stimuli induced NO production by early stage embryos that correlated with the induction of the inducible and/or endothelial isoforms of NO synthase. This study was also extended to the human system where sera from women who aborted were tested for their ability to act embryotoxically by inducing NO in early mouse embryos and mature murine placenta. The results obtained confirmed the embryotoxic character of NO found in these particular sera leading to the hypothesis that NO plays a potential role in early embryo death.

Abortion, Spontaneous↗
PubMed2000

The influence of long-term administration of conjugated estrogens and antiandrogens to serum leptin levels in women with polycystic ovary syndrome.

It is well known that a strong exponential relationship exists between leptin levels and body mass index (BMI). The different serum leptin levels, however, that are observed for each BMI value, suggest that other factors, as well, interfere with leptin secretion. This study was designed in order to estimate serum leptin levels in patients with polycystic ovary syndrome (PCOS), before and after long-term treatment with conjugated estrogens and antiandrogens. Sixteen women with PCOS were included in the study. They were divided into two groups: the first group comprised 11 non-obese women (BMI 21.6 +/- 0.5 kg/m2), aged 23.5 +/- 1.1 years; the second consisted of five obese women (BMI 28.9 +/- 1.5 kg/m2), aged 22.8 +/- 1.9 years. Blood samples for leptin measurement were drawn before and 2, 4, 6, 9 and 12 months after administration of conjugated estrogens and antiandrogens. Our results showed that obese women exhibited higher serum leptin levels in all blood samples. Moreover, the administration of conjugated estrogens and antiandrogens caused an increase in serum leptin levels in the 2nd, 4th, 6th and 9th month in both groups of women. Finally, leptin concentrations during the 12th month of the treatment returned to basic levels in both groups of women with PCOS. Our results support the view that BMI is the main variable that influences serum leptin levels, and that the effect of conjugated estrogens and antiandrogens on serum leptin concentrations is poor.

Adolescent↗
PubMed1999

Detection and clinical correlations of ras gene mutations in human ovarian tumors.

In epithelial ovarian neoplasms K-ras codon 12 gene mutations show a wide variation fluctuating between 4-39% in invasive carcinomas and 20-48% in borderline malignant tumors. In this study, we showed the pattern of point mutations in codon 12 of the K-ras, H-ras and N-ras genes, using polymerase chain reaction restriction fragment length polymorphism analysis in 74 tissue specimens of Greek patients with epithelial ovarian tumors. K-ras and H-ras gene mutations were detected in 11/48 (23%) and 3/48 (6%) cases with primary invasive ovarian carcinomas, respectively, while N-ras gene mutations were not found. No mutation of K-, H- and N-ras genes was detected in 23 ovarian cystadenomas. In 1 out of 3 borderline ovarian tumors (33%) we found an H-ras gene mutation. The prevalence of mutations in K-ras gene was 1/8 (13%) in mucinous, 7/29 (24%) in serous, 1/3 (33%) in endometrioid and 2/8 (25%) in clear-cell adenocarcinomas and in H-ras gene 1/8 (13%) in mucinous and 2/29 (7%) in serous adenocarcinomas. Analysis of the results revealed no significant correlation between ras gene mutations and clinicopathological parameters or clinical outcome of this primary invasive ovarian carcinoma population. Our present data suggest that ras gene mutations in invasive ovarian carcinomas occur in 29% of Greek patients and are not associated with the differentiation of the epithelial cells or the response of patients to adjuvant platinum-based chemotherapy.

Adenocarcinoma↗
PubMed1999

Serum soluble CD23 and TNF-alpha in women with spontaneous abortion in the first trimester.

The present study was designed to investigate the participation of sCD23 and TNF-alpha in pregnant women in the first trimester. One hundred and forty-one patients were enrolled in the study. Women were classified into two groups. Serum sCD23 and TNF-alpha were measured in 73 normal pregnant women in the first trimester (Group I) and in 68 women with spontaneous abortion (Group II). We found that the mean values of TNF-alpha levels were higher in women with normal pregnancy than in women with spontaneous abortion (p < 0.05), whereas sCD23 levels of women in group II did not differ statistically from the controls. These results sustain the opinion that women with spontaneous abortion seem to have reduced TNF-alpha levels. However, determination of these immunological parameters provides no useful clinical information about disease activity and management.

Abortion, Induced↗
PubMed1999

Infantile myofibromatosis: a case study and review of literature.

Infantile myofibromatosis is an unusual condition generally presenting in the newborn period. The case being reported is that of a female newborn who had multiple lesions that involved skin, subcutaneous tissue, skeletal muscles, bone, and lungs. The disease was diagnosed because of the easily palpable skin tumors and subcutaneous nodules that were obvious immediately after birth. The diagnosis was established by histopathological examination of one nodule that showed a spindle-celled mesenchymatogenic lesion demonstrating the morphological and immuno-phenotype characteristics of myofibroblastic differentiation. The histologic picture, combined with the clinical manifestations and the imaging findings, are consistent with infantile myofibromatosis. The physical condition of the newborn was excellent and remains so six months later. The tumors of the skin and the subcutaneous nodules have gradually regressed without therapy. At the age of six months, four (4) nodules are palpable; the infant is under continuous observation.

Bone Neoplasms↗
PubMed1999

Disposition of pesticides and toxicants in the human reproductive system in cases of acute poisoning.

The aim of this study was to estimate the penetration of some of the pesticides and toxicant substances in the human reproductive system. This knowledge is valuable because of the possible adverse influence of these substances on the human reproduction system and the development of the foetus during pregnancy. The existing data is mainly concerned with the results of experimental studies on animals or epidemiological studies. Here we report data concerning the disposition of several toxic xenobiotics (pesticides and solvents) in the tissues of the human reproductive system as well as in other organs and glands. Data was collected from cases of acute poisonings and derived mostly from autopsy materials. Xenobiotics were found to penetrate sampled tissues such as the testes, ovaries, epididymis, uterus, thyroid gland, as well as other human tissues. Further studies will clarify and confirm peculiarities of the penetration of a wide range of substances in various body tissues and will be the base of the estimation of the role of these toxicants in human reproductive ability and the outcome of pregnancy in humans.

Acute Disease↗
PubMed1998

Microsatellite mutations in spontaneously aborted embryos.

OBJECTIVE: To evaluate the incidence of microsatellite instability in spontaneously aborted embryos. DESIGN: Retrospective study. SETTING: Laboratory of Clinical Virology and Department of Obstetrics and Gynecology, University Hospital, Medical School, University of Crete. PATIENT(S): Thirty-five women in whom spontaneous abortions occurred between the 6th and 20th weeks of pregnancy. INTERVENTION(S): Thirty-five aborted embryonic tissues were analyzed with seven microsatellite markers, and their haplotypes were compared with the corresponding pattern of their parents. MAIN OUTCOME MEASURE(S): Microsatellite DNA. RESULT(S): Microsatellite instability was observed in 8 of 35 cases (23%). In 7 of 8 positive cases, microsatellite instability was restricted to one of the seven microsatellite markers, whereas in one case, three microsatellite markers were affected by instability. A statistically significant association was found between microsatellite instability and a previous normal childbirth. CONCLUSION(S): Genetic instability is a detectable phenomenon in spontaneous abortions, representing a significant increase in the mutational rate of the embryo and providing evidence for a mechanism associated with the phenomenon of spontaneous abortion. We conclude that this elevated mutational rate affects active genomic sequences that play a critical role in the viability of the embryo, leading to cell death and abortion.

Abortion, Spontaneous↗
PubMed1998

Phenotypic characteristics of cord blood hemopoietic cells.

Bone marrow transplantation is limited due to the lack of HLA-matched donors and to the frequent occurrence of GvHD. Hemopoietic transplants using cord blood cells are being increasingly used in pediatric patients. In this study, the immunophenotypic characteristics of cord blood cells have been investigated by one or two-color flow cytometric analysis. The CB cells were characterized by a low proportion of CD3+ T-cells, increased CD4/CD8 and CD45RA/CD45RO ratios, minimal expression of HLA-DR, increased proportion of CD5CD19 double positive B-cells, while CD3- CD8+ and CD3- CD7+ subsets, not usually found in adult PB, were detected. These data reflect the immaturity of CB cells as assessed by immunophenotypic analysis suggesting that it could be a valuable alternative source of transplantable hematopoietic progenitor cells and might alleviate some of the problems associated with bone marrow or peripheral blood transplantation.

Antigens, CD↗
PubMed1998

Evaluation of Parvo B19, CMV and HPV viruses in human aborted material using the polymerase chain reaction technique.

OBJECTIVE: To investigate the role of human parvovirus B19 (Parvo B19), cytomegalovirus (CMV) and human papilloma virus (HPV) viruses in the aetiopathogenesis of spontaneous abortions. STUDY DESIGN: Abortion material from 102 cases of women with spontaneous abortions were analysed for the presence of Parvo B19, CMV and HPV DNA using the polymerase chain reaction (PCR) technique. Serological assays were used for the detection of specific IgM and IgG antibodies against Parvo B19 virus and CMV in the maternal sera. RESULTS: Parvo B19 virus genome was detected in two cases of spontaneous abortion, by PCR amplification, while CMV and HPV genomes were not observed. Serological markers were indicative for Parvo B19 virus and CMV infection in ten and four cases, respectively. CONCLUSIONS: PCR is a useful method for investigating the viral contribution to the aetiopathogenesis of spontaneous abortions and for detecting the viral genome in the abortion material. This study of 102 cases of spontaneous abortion does not implicate CMV and HPV in the aetiopathogenesis of spontaneous abortion, although it indicates a possible abortional role for Parvo B19 virus.

Abortion, Spontaneous↗
PubMed1998

The sperm deformity and the sperm multiple anomalies indexes in patients who underwent unilateral orchectomy and preventive radiotherapy.

Two new indices, the sperm deformity and the sperm multiple anomalies index, were assessed in 16 male patients who underwent unilateral orchectomy owing to seminoma and in preventive radiotherapy of paraortic and of the iliac lymph glands homolateral to the testis excised. The aim was to assess the value of these two morphological sperm parameters in distinguishing the semen between the above mentioned group of men from the semen of men with other causes of infertility. It was found that: (1) the values of the sperm deformity index and those of the sperm multiple anomalies index were not significantly different between men who underwent unilateral orchectomy and preventive radiotherapy and the men with other causes of subfertility and (2) the values of the above indices were significantly higher in the semen specimens of men who underwent unilateral orchectomy and preventive radiotherapy and in the semen specimens of men with other causes of subfertility than in the semen specimens of fertile men. It is concluded that testicular response, as far as sperm morphology is concerned, is the same irrespective of the cause exerting a negative effect on spermatogenesis.

Adult↗
PubMed1998

Headless spermatozoa in fertile men.

Headless or unucleated spermatozoa were evaluated in semen specimens of 52 fertile men in order to investigate the frequency and the percentage of this morphological abnormality and to estimate the probable correlation of the abnormality with other semen parameters, since there are no available data. The only sperm parameter which correlated with the number of headless spermatozoa was the number of micro round-headed spermatozoa (r= + 0.4432, P<0.001). It is concluded that the high frequency of headless or unucleated spermatozoa in the semen specimens of fertile men, albeit in low percentage, does not seem to have any biological significance. Moreover headless and round-headed spermatozoa could be the outcome of the same pathogenetic mechanism.

Journal Article↗
PubMed1998

Congenital capillary hemangioma and its therapeutic approach in infants: a case report.

Hemangiomas, common congenital lesions in infants and children, are thought to arise when islands of angioblastic tissue fail to connect with the developing vascular system. They are not usually life-threatening. A case of congenital capillary hemangioma in an infant, which was surgically excised, is reported, and therapeutic approaches are discussed.

Blood Vessels↗