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Biomedical subjects

M Ergazaki

Publications and source records attributed to M Ergazaki.

At least 19 recordsLinked to original sources
PubMed2001

Prevalence of hepatitis B and C markers in high-risk hospitalised patients in Crete: a five-year observational study.

BACKGROUND: So far the prevalence of viral hepatitis infection in hospitalized patients has not been extensively studied. Therefore we conducted the present five-year observational study to evaluate the prevalence of HBV and HCV infection in high-risk hospitalized patients of Crete, the largest Greek island, Due to the homogeneous population, epidemiological studies can be accurately done. METHODS: The study was carried out in two out of four District General Hospitals, and in the University Hospital of the island. Markers for HBV and HCV were studied and statistically evaluated according to age, sex and geographical area, in a well-defined hospitalized population. RESULTS: The total prevalence of HBsAg and anti-HCV in the three prefectures during the five-year study is 2.66% and 4.75% respectively. Overall the relative risks were higher in males than females for each hepatitis marker (p < 0.001). Higher prevalence of HBcAb was found in the 41-60 years age group for both sexes (males 36.17%, females 27.38%). Peak HBsAg prevalence was found in the age group of 21-40 and 41-60 years for males (5.4%) and females (3.09%) respectively. Anti-HCV prevalence increases with age reaching the highest prevalence in the age group of 41-60 years for males (7.19%) and in the 61-90 years age group for females (7.16%). For both sexes significant differences between the three locations were identified. For HBsAg a higher prevalence in Heraklion (3.96%) compared to Chania (2.30%, males: p < 0.0001, females: p < 0.05) and Rethymnon (1.45%, males: p < 0.01, females: p < 0.0001) was detected. For HCV a significantly higher prevalence in Heraklion (6.54%) compared to Chania (2.39%, males: p < 0.001, females: p < 0.001) but not in Rethymnon (5.15%, NS). A lower prevalence rate of HBcAb in Heraklion compared to Chania (20.07% versus 23.05%, males: p < 0.001, females: p < 0.001) was found. CONCLUSIONS: These results were possibly overestimated, but nevertheless reflect the situation of the general population within the island as shown by our previous publications in other study groups. Moreover they contribute to the mapping of viral hepatitis prevalence in a geographical area of Southern Europe and may be helpful in planning public health interventional strategies.

Adult↗
PubMed1999

Loss of heterozygosity and microsatellite instability in human non-neoplastic hepatic lesions.

AIMS/BACKGROUND: Carcinogenesis is thought to be a multistage process that occurs as a result of mutations in oncogenes and tumor suppressor genes. One way to monitor a vast range of these changes is by microsatellite PCR amplification that detects loss of heterozygosity and microsatellite instability between normal and tumor specimens of the same subject. Viral cirrhosis is considered a strong predisposing factor for the development of liver cancer. The aim of the study therefore was to examine precancerous hepatic lesions and compare them with others not considered as high risk for hepatocellular carcinoma. METHODS: We examined 43 subjects for 19 microsatellite markers spanning chromosomes 1, 9 and 17. Normal specimens were blood samples that were compared to liver needle biopsies. Samples were classified according to histological features as non-cancerous (10 cases) and pre-cancerous (33 cases, chronic hepatitis and cirrhosis). RESULTS: Our results indicate that there is a tendency of increased chromosomal alteration as lesions become chronic. Samples from patients with antibodies to antibodies for hepatitis C virus show more alterations than hepatitis B positive samples. Steatohepatitis, a disease of unknown etiology, appears to have a high number of microsatellite abnormalities. CONCLUSIONS: Microsatellite APOA2 located on chromosome 1, shows a statistically significant increase in the rate of loss of heterozygosity as liver lesions become more severe, indicating the presence of tumor suppressor genes which may be involved in the development of these lesions.

Apolipoprotein A-II↗
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

Detection of herpes simplex virus (HSV) in aborted material using the polymerase chain reaction technique.

OBJECTIVE: To investigate the contribution of HSV to the aetiopathogenesis of spontaneous abortion. DESIGN: A hospital-based, case-control study. SETTING: Department of Obstetrics and Gynecology, University Hospital and Laboratory of Clinical Virology, Medical School, University of Crete, Heraklion, Crete, Greece. POPULATION AND METHODS: Abortion material from 102 cases of women with spontaneous abortion was analysed for the presence of HSV DNA applying the PCR technique. Serological assays were used for the detection of specific IgM and IgG antibodies in the maternal sera of 90 pregnant women with successful outcome of their pregnancy while 70 non-pregnant women at reproductive age were also examined as control. RESULTS: The HSV genome was detected by PCR amplification in 3 cases of spontaneous abortion, 2 of them exhibited serological markers of virus reactivation while the 3rd showed a past infection. There were no obvious clinical manifestations indicating a current herpes infection. Both groups of pregnant women, either with spontaneous abortion or with a successful outcome of pregnancy, displayed serological markers of HSV reactivation at higher rates compared with non-pregnant women (chi2, p < 0.05). CONCLUSIONS: Using the PCR technique we were able to detect the HSV genome in gestational tissues of spontaneous abortions, even in cases without any clinical symptoms or seropositivity for a primary infection. Serological assays were not very useful for the elucidation of the role of HSV in inducing spontaneous abortions, although they indicate that the state of pregnancy predisposes to HSV reactivation. However, the detection of HSV in 3 out of a total number of 102 cases does not support HSV infection as a major abortion-related factor.

Abortion, Spontaneous↗
PubMed1996

Loss of heterozygosity and microsatellite instability in human atherosclerotic plaques.

Several lines of evidence suggest that mutation events may be involved in the development of atherosclerosis. The aim of the present investigation was to perform an allelotype analysis in 30 atherosclerotic lesions in order to reveal any deletions involved in the development of the disease. Eighteen chromosomal arms were tested by one microsatellite marker located on each arm and allelic imbalance in at least one marker was observed in 7 (23%) cases. Furthermore, the analysis revealed the presence of microsatellite instability (MI) in 10 (33%) cases, suggesting that an increase in the mutation rate may be involved in the formation of the plaque. These results highlight the mutation concept for the atherogenesis and suggest that LOH and MI may be involved in the development of the disease.

Arteriosclerosis↗
PubMed1996

Microsatellite instability in human atherosclerotic plaques.

The aetiopathology of atherosclerosis remains obscure. Although histologically the accumulation of lipids and the proliferation of the smooth muscle cells represents the main feature of the disease, little is known as regards the molecular alterations associated with the atherosclerotic lesions. In the present study we investigated whether an elevated mutational rate is detectable in human atheromatous plaques. Thirty specimens were assessed for microsatellite instability (MI) by 7 microsatellite markers and MI, in at least one marker, was apparent in 6 (20%) cases. Our data suggest that decreased fidelity in DNA replication and repair may be associated with the development of the disease.

Aged↗
PubMed1996

Mutations and expression of the ras family genes in leukemias.

The levels of expression and the incidence of codon 12 point mutations of the ras family genes were studied in 18 cases of leukemia, seven with acute myeloblastic leukemia (AML), three with acute lymphoblastic leukemia (ALL), four cases with chronic myelogenic leukemia (CML) and four cases with chronic lymphocytic leukemia (CLL). Elevated expression of the ras genes was found for 39%, 61% and 67% of the specimens for the H-ras, K-ras and N-ras, respectively. A trend was found between the overexpression of the N-ras gene and the acute leukemias: all 10 acute leukemias exhibited overexpression of the N-ras gene, while only two of the CML cases, both in blastic crisis, showed elevated levels of the N-ras gene. Codon 12 point mutations at the N-ras gene were found in two of seven cases (28%) with AML and one of four cases (25%) with CML. The only K-ras codon 12 point mutation was found in a patient with CLL. No mutations were found in the codon 12 of H-ras. Our data suggest that apart from the point mutations, overexpression of the ras family genes is important in the development of the disease.

Codon↗
PubMed1996

Glucocorticoid and estrogen receptors have elevated activity in human endometrial and ovarian tumors as compared to the adjacent normal tissues and recognize sequence elements of the H-ras proto-oncogene.

We examined the level of receptor binding in H-ras elements, using nuclear extracts derived from human endometrial and ovarian lesions and from adjacent normal tissue in gel retardation assays. We found increased binding of the glucocorticoid receptor (GR) to the H-ras GR element in more than 90% of endometrial tumors and in all ovarian tumors tested, as compared to the corresponding adjacent normal tissue. Additionally, we found elevated binding of the estrogen receptor (ER) in H-ras ER element in all pairs of ovarian tumor/normal tissue tested, whereas in ER-negative control breast tumor/normal tissue pairs, no differences in ER DNA-binding levels were observed. These results suggest that steroid hormone receptor binding could directly activate the H-ras oncogenic potency in human endometrial and ovarian lesions, providing additional evidence for the role of H-ras expression in hormonally responsive human cancers.

DNA, Neoplasm↗
PubMed1996

The association of the H-ras oncogene and steroid hormone receptors in gynecological cancer.

Expression of the ras family of cellular oncogenes is associated with tumorigenicity, invasiveness and metastatic potential in a variety of human carcinomas. Additionally, H-ras cooperates with glucocorticoids and with ovarian hormones in cell transformation and in the development of mammary carcinomas. Steroids are considered to be tumor promoters and their levels influence the cure rates and survival of the patients with gynecological lesions. It is proposed that they exert tumor promoting activity by transcriptional regulation of nuclear proto-oncogenes, such as c-fos, c-jun, and c-myc. The human H-ras gene contains within its first and fourth introns, sequences that are specifically recognized by glucocorticoid and estrogen receptors, respectively. Using gel retardation assays, the level of steroid receptor binding in H-ras elements has been compared, employing nuclear extracts from human endometrial and ovarian lesions and from the adjacent normal tissue. Elevated binding of the glucocorticoid and estrogen receptors in the corresponding H-ras elements in almost all tissue pairs tested has been found. It is suggested that the H-ras proto-oncogene is hormonally regulated and directly implicated in human gynecological cancer through elevated, steroid-induced gene expression.

Female↗
PubMed1995

Loss of heterozygosity at 9p and 17q in human laryngeal tumors.

Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour suppressor genes (TSGs) with an important role in multistage carcinogenesis. At the 9p arm is located the p16 (MTS1) TSG and probably others with an effect on various human tumours such as acute lymphoblastic leukaemia, bladder cancer, gliomas, malignant mesotheliomas, melanomas and non-small cell lung carcinomas. In addition, the 17q arm harbours BRCA1 TSG which is responsible for approximately 80% of the familial breast/ovarian cancer cases. In order to investigate the implication of these performed a loss of heterozygosity (LOH) analysis with 10 polymorphic microsatellite markers (three at the 17q arm surrounding the BRCA1 region and seven at the 9p arm). Fourteen of the 17 (82%) tumours exhibited deletions at 9p. The highest incidence of LOH (6/13, 46%) was found for the marker D9S157 at 9p22. One sample exhibited deletion of all the informative markers tested indicating deletion of the complete 9p arm. No homozygous deletions were found. LOH at the 17q arm near the BRCA1 locus was found in 6 (35%) among 17 specimens. The results of this study indicate that allelic deletions at 9p are frequent in the development of laryngeal tumours. The highest incidence of LOH was found for the marker D9S157 which is near, but distinct from the location of p16 (MTS1) tumour suppressor gene, indicating the presence of multiple tumour suppressor genes within this chromosomal region. In addition, BRCA1 TSG is implicated in the development of laryngeal tumours.

Carcinoma, Squamous Cell↗
PubMed1995

Association of herpesvirus infection with the development of genital cancer.

Clinical observations and epidemiological studies on genital cancer have revealed an association with sexual behavior, thus motivating research into sexually transmitted agents which may be responsible for the neoplasia. In this study, we used the PCR technique to examine the presence of CMV, HSV and EBV viruses in 187 cases of human genital lesions and found that infection with CMV or HSV was associated with cervical cancer. When we stratified according to HPV status this association was found only for HPV-DNA-negative cases. These findings indicate that past infection with CMV or HSV could be interpreted as a surrogate marker of HPV infection. However, these viruses may play an important role themselves in cervical cancer.

Amino Acid Sequence↗
PubMed1995

Instability at the H-ras minisatellite is associated with the spontaneous abortion of the embryo.

Recently we have shown that microsatellite instability (MI) is a detectable phenomenon in aborted embryonic tissues. In the present study we investigated if instability is also detectable in a minisatellite located at the 3'-end of the H-ras proto-oncogene, affecting either the repetition number of the 28-bp core generating larger or smaller alleles or its sequence creating a detectable restriction fragment length polymorphism (RFLP). Among 30 aborted embryonic tissues, alterations at the repetition number of the core were found in 3 (10%) while point mutations were detected in 7 (23%) cases. These results indicate that structural alterations of the H-ras minisatellite may be associated with the rejection of the embryo.

Abortion, Spontaneous↗
PubMed1995

Detection of Epstein-Barr virus and human papillomavirus in nasopharyngeal carcinoma by the polymerase chain reaction technique.

We used the PCR technique to detect the Epstein-Barr virus (EBV) and human papillomavirus (HPV) DNA in paraffin-embedded tissues from Greek patients with nasopharyngeal carcinoma (NPC). The oligonucleotide primers used for the detection of EBV amplify a 375-bp long sequence from the EcoRI B fragment of the viral genome, whereas for HPV the primers amplify a 151-bp long sequence of the viral genome. The PCR products were analysed by agarose gel electrophoresis and visualised by UV illumination after staining with ethidium bromide. Sixty-three specimens were examined. EBV specific sequence was amplified in 20 (32%) and HPV in 12 (19%) out of the 63 samples. There was no co-infection with EBV and HPV. Although there is a high correlation of EBV infection with poorly differentiated NPC in patients from Southern China and South-East Asia, the restricted distribution suggests genetic or environmental cofactors in the development of the neoplasm. Our results confirm this suggestion since there was only a 32% correlation of EBV with NPC in Greece. HPV may also be involved in the carcinogenesis of EBV-negative squamous cell nasopharyngeal carcinomas.

Base Sequence↗
PubMed1995

Detection and analysis of hepatitis C virus by a combined RT-PCR method: variation in the 5' non-coding region of the viral genome.

A combined reverse transcription-polymerase chain reaction (RT-PCR) method was employed for the detection of hepatitis C virus (HCV) RNA in serum from patients with chronic active hepatitis, with primers corresponding to the 5' non-coding region. The diagnosis was based on serological and biochemical methods and on liver biopsy. HCV-RNA was detected in 27 (90%) of 30 sera examined. The nucleotide sequence of PCR-amplified HCV cDNAs (256 bp) was determined from five specimens and heterogeneity varying between 0.58% and 2.89% among the clinical samples and the prototype HCV-1 was found.

Base Sequence↗
PubMedDate not supplied

ras gene mutations in human endometrial carcinoma.

The purpose of this study was to assess the extent of involvement of the ras oncogene activation by point mutations in endometrial carcinoma in the Greek population. The PCR technique was employed, followed by RFLP analysis to identify the point mutations in codon 12 of the K-ras, H-ras and N-ras genes. K-ras gene point mutations were detected in 8 of the 55 cases (15%) of primary endometrial carcinoma, H-ras in 4 (7.3%), while no mutations were found for the N-ras gene. No correlation was found between the presence of ras gene mutations and the clinicopathological parameters, or patient survival. The only association found was between H-ras mutations and the FIGO stage of the tumor (Fisher's exact test, p = 0.011). These results indicate a possible role of ras gene activation in a small subset of endometrial carcinomas.

Carcinoma↗
PubMedDate not supplied

Detection of Epstein-Barr virus genome in squamous cell carcinomas of the larynx.

Epstein-Barr virus (EBV) is a B-lymphotropic virus with a tumorigenic potential. EBV infection has been recognized as the main cause of nasopharyngeal carcinoma and Burkitt's lymphoma. The aim of our study was to determine the incidence of EBV in squamous cell carcinomas of the larynx. We employed for our analysis a sensitive polymerase chain reaction (PCR) assay, followed by restriction fragment length polymorphism (RFLP) for further confirmation of the specificity of the PCR-amplification reaction. Our analysis revealed that 9 of 27 (33%) specimens harbored the EBV genome in the tumor tissue while only 4 (15%) specimens from adjacent normal tissue exhibited evidence of EBV infection. Three were EBV positive for both normal and tumor tissue. No association has been found with disease stage, histological differentiation and nodes at pathology. The relatively high incidence of EBV in the tumor tissue (33%) of patients with laryngeal cancer, as compared to the low (15%) incidence of the virus genome detected in the adjacent normal tissue of the patients, indicates a probable role of EBV in the development of the disease.

Base Sequence↗
PubMedDate not supplied

Transcriptional activation of the human immunodeficiency virus long terminal repeat sequences by retinoic acid in human epithelial and fibroblast tumor cell lines.

We employed a recombinant plasmid, pBHIV1, carrying the long terminal repeat (LTR) sequences of HIV-1 linked to the reporter chloramphenicol acetyl transferase (CAT) gene and to the aminoglycoside phosphotransferase (aph) gene as a selectable marker. We introduced pBHIV1 into human epithelial and fibroblast tumor cell lines (HeLa and MRCSV40TGR), and obtained stable geneticin-resistant HLHIV1-A and SVTGHIV1-A cells, respectively. The response to the retinoic acid was studied on the LTR regulated CAT activity in both cell lines. It was found that retinoic acid at a concentration of 1x10(-5) effects a 3.2 -fold increase in CAT expression compared to HIV LTR in HLHIV1-A, but requires a concentration of 5x10(-5) M to enhance this expression 4.6-fold in SVTGHIV1-A cells. These data show that retinoic acid may play a critical role in HIV-1 expression in human epithelial and fibroblast cell lines.

Cell Division↗