PubMed Health⌕ Search

Biomedical subjects

I Diamantis

Publications and source records attributed to I Diamantis.

At least 19 recordsLinked to original sources
PubMed2001

Effect of oral D-tagatose on liver volume and hepatic glycogen accumulation in healthy male volunteers.

Standard toxicity tests with high levels of D-tagatose showed a reversible enlargement of the liver in Sprague-Dawley rats without increase of liver enzymes. The present study tests the hypotheses that partial substitution of dietary sucrose by D-tagatose for 28 days increases the volume of human liver and the concentration of liver glycogen. Twelve healthy, male volunteers were studied in a double-blind crossover study with ingestion of D-tagatose (3x15 g daily) and placebo (sucrose, 3x15 g daily) for periods of 28 days each. Liver volume and glycogen concentration have been determined by magnetic resonance (MR) imaging and spectroscopy, which were accompanied by routine medical examinations. MR examinations before and after the treatments revealed no effects (P>0.05) of treatment, period, or subject for changes in liver volume or glycogen concentration. A steady increase of liver volumes, independent of the D-tagatose or placebo intake, has been observed over the study in parallel with a slight increase in body weight. The treatment with D-tagatose was not associated with clinically relevant changes of the examined clinico-chemical and hematological parameters, including liver enzymes and uric acid.

Administration, Oral↗
PubMed2000

Cloning of the rat ADAMTS-1 gene and its down regulation in endothelial cells in cirrhotic rats.

AIMS: This study was undertaken in order to identify genes which are regulated during the process of liver fibrosis. METHODS: The differential display method and RNA from rat endothelial cells before and after induction of cirrhosis were used. RESULTS: A 496 bp fragment, which was down regulated in liver endothelial cells from a cirrhotic animal, was cloned. The cloned fragment showed a 95% homology with the newly cloned mouse ADAMTS-1 gene (a disintegrin and metalloproteinase with thrombospondin motifs), which is implicated in inflammation. The fragment was found to span the 3' of exon 6, the whole exon 7 and the 5' of exon 8. Sequencing of the entire coding region of the rat gene showed a 94% homology at the nucleic acid level and 96% homology at the amino acid level. The sequences responsible for the function of the protein were conserved. Northern blot analysis, using the cloned fragment as a probe, confirmed the finding that the gene was down-regulated in endothelial cells derived from livers of cirrhotic animals. In situ PCR analysis localised the ADAMTS-1 gene in the liver endothelial cells from normal animals. CONCLUSIONS: Regulation of the expression of genes which belong to the metalloproteinase family in liver endothelial cells might be important in the development of liver cirrhosis.

ADAM Proteins↗
PubMed1998

Detection of endothelin-1 and its receptors in rat liver endothelial cells by in situ reverse transcriptase-polymerase chain reaction.

BACKGROUND/AIMS: Endothelin (ET)-1 is a potent vasoconstrictor, also in the liver; it increases intrahepatic resistance by targeting hepatic stellate cells acting via the ET-A receptor. The role of the expression and regulation of ET-1 and its receptors in endothelial liver cells, an important site of ET production in normal liver, is not yet well documented. In the present study, we have developed an in situ reverse transcriptase (RT)-polymerase chain reaction method to elucidate the presence of prepro-ET-1, ET-A and ET-B receptors in isolated rat liver endothelial cells. METHODS: After in situ collagenase-pronase liver perfusion, endothelial cells were isolated using a Nycodenz gradient. RT-polymerase chain reaction and in situ RT-polymerase chain reaction were performed using specific primers for prepro-endothelin, ET-A and ET-B. RESULTS: Trypan blue exclusion test showed a viability of more than 90% in the freshly isolated non-parenchymal cells. RT-polymerase chain reaction showed expression of prepro-endothelin, ET-A and ET-B in RNA isolated from the endothelial cells. After in situ RT-polymerase chain reaction, we detected cytoplasmatic staining representing the presence of mRNA in the endothelial cells, with all sets of primers. About 60-80% of cells were positive. Negative controls, in which the RT step was omitted, did not show any cytoplasmatic staining. CONCLUSIONS: Endothelin 1 and both ET-A and ET-B receptors are expressed in rat endothelial liver cells. The expression of ET and its receptors in liver endothelial cells could be important in the development of liver diseases and the regulation of microvascular exchange.

Animals↗
PubMed1998

Genotype distribution of hepatitis C virus infection in Greece: correlation with different risk factors and response to interferon therapy.

The aim of this study was to investigate the prevalence of HCV genotypes among Greek patients with chronic hepatitis C and to assess the influence of genotypes and quasi-species populations on efficacy of interferon therapy. Genotypes were determined in 65 patients (18 patients after kidney transplantation, 16 with thalassemia and 31 with no known risk factor) with elevated ALT for more than 6 months and histologically proven chronic hepatitis, using the Inno-Lipa strip assay. The quasi-species were determined using the fluorescence single-strand conformational polymorphism method. Most patients were infected with genotype 3a, namely 61% of patients with kidney transplants (n = 18), 50% of patients with thalassemia (n = 16) and 48% of patients without known risk factors (n = 31). Other genotypes were found including coinfection with different genotypes. In all patients with mixed infection, genotype 3a was present. Thirty-six patients from the last two groups received interferon (3Mio U 3x week) for 1 year. Biochemical and/or virological and histological responses were found in 11/19 patients with genotype 3a (58%), 3/5 with mixed infection, 2/4 with genotype 1b, 2/5 with genotype 2a, 1/4 with genotype 1a and 1/1 with genotype 4. The virus found in non-responders with genotype 3a was genetically more heterogeneous than in responders. These data indicate that (1) the genotype 3a is prevalent in Greek patients (68% of all patients), (2) there is no significant difference regarding genotypes among patients with different risk factors and (3) although based on a small number of patients, the genotype 3a seems to respond better to interferon therapy. Finally, the number of quasi-species may be a factor predictive of response.

Adult↗
PubMed1997

High prevalence and coinfection rate of hepatitis G and C infections in intravenous drug addicts.

BACKGROUND/AIMS: The hepatitis G virus is a newly discovered RNA virus which is possibly transmitted parenterally. Hepatitis G virus is associated with acute or chronic hepatitis and may lead to cirrhosis and liver cancer, characteristics shared by the hepatitis C virus. Hepatitis C virus is prevalent in drug users, but the frequency and role of hepatitis G virus is not yet well established. METHODS: One hundred and seventeen heavy i.v. drug users were enrolled in a prospective, controlled, randomized study for i.v. administration of heroin and/or methadone. Hepatitis G virus was detected using a hot start polymerase chain reaction followed by an ELISA polymerase chain reaction assay. Hepatitis C virus genotyping was done using the Inno-Lipa strip assay. RESULTS: Hepatitis G virus infection was detected in 35% (41/117) of the study population and hepatitis C virus infection in 95.7% (112/117). Ninety-seven percent of hepatitis G virus positive patients were coinfected with hepatitis C virus, of whom 75% were infected with hepatitis C virus genotype 3a. This genotype was prevalent in 48.3% of patients infected with hepatitis C virus alone. The presence or absence of hepatitis G virus infection had no influence on chronic hepatitis. Twenty-two percent of patients who started injecting heroin before 1980 and 40% of those who started after 1980 were hepatitis G virus positive. Overall, 16 patients were infected with human immunodeficiency virus, six were coinfected with hepatitis G virus and hepatitis C virus, and 10 only with hepatitis C virus. CONCLUSIONS: Hepatitis G virus infection is highly prevalent in i.v. drug users, but less frequent than hepatitis C virus infection. The fact that all but two patients were coinfected with hepatitis C virus, 75% with one genotype, supports a common route of transmission for both viruses. The course of hepatitis C virus infection is not altered by hepatitis G virus infection.

Enzyme-Linked Immunosorbent Assay↗
PubMed1995

p53 protein expression in colorectal adenomas: an immunohistochemical study using an antigen retrieval system.

The immunohistochemical expression of the p53 gene product was examined in 91 colorectal adenomas from patients without (group 1, 50 cases) or with (group 2, 41 cases) concurrent sporadic colorectal carcinoma, and in 15 additional cases of randomly selected carcinomas from group 2 patients. Immunohistochemical reactions were performed with the DO-7 monoclonal and the CM1 polyclonal antibodies, following microwave irradiation of the tissues in an antigen retrieval solution, and the proportion of the immunoreactive cells was semiquantitatively assessed. p53 protein immunoreactivity was present in 46.1% (42, of 91, i.e., 20 out of 50 of group 1 and 22 out of 41 of group 2) and 33% (30 of 91, i.e. 14 out of 50 of group 1 and 16 out of 41 of group 2) of the adenomas using DO-7 and CM1 antibody, respectively. High p53 expression (i.e. immunolabelling of more than 30% of the tumour cell nuclei) was found in 13.2% of the adenomas (12 of 91, i.e. three out of 50 of group 1 and nine out of 41 of group 2; P = 0.025 using the chi 2 test) using the DO-7 antibody, and in 6.6% of the cases (six of 91, i.e. two out of 50 of group 1 and four out of 41 of group 2) using the CM1 antibody. In carcinomas, 80% of the cases (i.e. 12 of 15) were found to express p53 protein with both antibodies. p53 immunoreactivity in colorectal adenomas increased with the degree of dysplasia: only five (17.8%) of the 28 adenomas with mild dysplasia were found to be DO-7 positive, while all of them remained CM1 negative. From the 50 adenomas exhibiting moderate dysplasia, 28 (56%) were DO-7 positive, and 22 (44%) were CM1 positive. Finally, from the 13 adenomas with severe dysplasia, nine (69.2%) and eight (61.5%) were found to be positive with the DO-7 and the CM1 antibody, respectively. Our results indicate that an increased number of group 2 adenomas express p53 protein, when compared with group 1 adenomas, and suggest that a strong correlation exists between p53 protein expression and the degree of dysplasia in colorectal neoplasms.

Adenoma↗
PubMed1995

p53 protein immunoreactivity in extrahepatic bile duct and gallbladder cancer: correlation with tumor grade and survival.

Forty-five extrahepatic bile duct carcinomas (i.e., tumors of the region proximal to the duct junction, including Klatskin tumors, tumors of the lower mid-region, and tumors of the ampulla of Vater) and 11 gallbladder carcinomas were immunohistochemically examined for p53 protein expression, using the DO-7 monoclonal (mAb) and the CM-1 polyvalent (pAb) antibodies and an antigen retrieval method. Because the DO-7 mAb was found to be significantly more reliable than the CM-1 pAb in detecting p53 immunoreactivity, the immunohistochemical results obtained with the former antibody were used for comparing p53 protein immunoreactivity with tumor site, tumor grade, and survival of patients. Approximately one third (3 of 10) of the proximal tumors were found to express weak p53 immunopositivity, whereas moderate immunopositivity and higher rate (18 of 29) was observed in tumors of the lower mid-region. Finally, moderate and marked p53 immunopositivity was observed in tumors of the ampulla (5 of 6) and gallbladder (8 of 11). In tumors of the lower mid-region of the ampulla and the gallbladder, a significantly higher p53 positivity was noted in high-grade compared with low-grade neoplasms. For the cases in which complete follow-up was available (11 tumors of the low mid-region), median survival of patients with p53-negative tumors was 25.7 months, whereas survival of those with p53-positive tumors was 5.2 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Ampulla of Vater↗
PubMed1994

Ki-67 immunoreactivity in human central nervous system tumors: a study with MIB 1 monoclonal antibody on archival material.

Paraffin-embedded surgical specimens from 136 primary human central nervous system (CNS) tumors, including 50 meningiomas, 24 astrocytomas, 26 anaplastic astrocytomas, 9 glioblastomas, 8 oligodendrogliomas, 4 ependymomas, 1 anaplastic ependymoma, 2 subependymomas, 9 medulloblastomas, and 3 paragangliomas, were immunostained, following microwave processing, using a streptavidin/peroxidase method and the MIB 1 monoclonal antibody (mAb) against the Ki-67 antigen. The following mean Ki-67 labeling index (LI) values +/- SD were found: meningiomas, 2.47 +/- 1.83; astrocytomas, 2.03 +/- 2.03; anaplastic astrocytomas, 12.80 +/- 6.29; glioblastomas, 14.57 +/- 6.77; oligodendrogliomas, 5.06 +/- 4.78; ependymomas, 2.63 +/- 2.58; anaplastic ependymoma, 6.89; subependymomas, 1.79 +/- 1.54; medulloblastomas, 18.77 +/- 9.65; and paragangliomas, 2.19 +/- 2.51. Our findings indicate that while malignant CNS tumors always exhibited high Ki-67 LI values, and benign CNS tumors generally displayed lower values, increased immunoreactivity for Ki-67 epitopes (Ki-67 LI higher than 4) was noted in a number of meningiomas, astrocytomas, ependymomas, oligodendrogliomas and paragangliomas, contrasting with their benign histological features. Further investigations of the Ki-67 immunoreactivity in CNS tumors and systematic correlation with the postoperative follow-up of patients are necessary to determine the value of Ki-67 LI in predicting the biological behavior of CNS neoplasms.

Antibodies, Monoclonal↗
PubMed1994

[Detection of bcr-abl transcripts in "minimal residual disease" in chronic myelogenous leukemia by nested polymerase chain reaction (PCR)].

We compared two non-radioactive PCR methods, a single step PCR and a nested PCR, for detecting bcr-abl transcripts in patients with chronic myelogenous leukemia (CML). The nested PCR assay was about thousand times more sensitive than the single step PCR. In 75 clinical samples tested in parallel, the sensitivity for the single step PCR and the nested PCR was 43.2% and 91.9%, respectively. In all 17 samples of 9 patients before bone marrow transplantation (BMT), bcr-abl transcripts were detected by the single step PCR. After BMT, 5 (9.8%) of 51 samples of 4 patients were positive by the single step PCR and 17 (33.3%) of 7 patients by the nested PCR. These data indicate that single step PCR may miss minimal residual disease whereas nested PCR is a sensitive alternative to the use of radioactive probes.

Bone Marrow Transplantation↗
PubMed1993

p53 protein expression in central nervous system tumors: an immunohistochemical study with CM1 polyvalent and DO-7 monoclonal antibodies.

Formalin-fixed, paraffin-embedded surgical specimens from 137 primary central nervous system tumors, including 26 astrocytomas (21 fibrillary, 1 protoplasmic, 1 gemistocytic and 3 pilocytic), 26 anaplastic astrocytomas, 9 glioblastomas, 1 gliosarcoma, 8 oligodendrogliomas, 4 ependymomas, 1 anaplastic ependymoma, 2 subependymomas, 3 paragangliomas, and 57 meningiomas, were immunostained with the CM1 polyclonal (pAb) and the DO-7 monoclonal (mAb) antibodies against the p53 protein, using the streptavidin/peroxidase method. In addition, two series of 17 and 9 medulloblastomas were also immunostained with the above pAb and mAb, respectively. p53 protein expression was observed in 7 fibrillary astrocytomas, 17 anaplastic astrocytomas, 5 glioblastomas, 1 gliosarcoma, 1 oligodendroglioma, 1 anaplastic ependymoma, and 4 meningiomas with the CM1 pAb. An additional 10 cases (i.e., 3 anaplastic astrocytomas and 7 meningiomas) were found to be p53 protein positive with the DO-7 mAb. Of the medulloblastomas, 8 (of the 17) and 4 (of the 9) were found to express p53 protein with CM1 pAb and DO-7 mAb, respectively. Our results indicate that p53 protein is expressed in a number of central nervous system neoplasms, and suggest that in astrocytic tumors a possible association may exist between p53 protein expression and tumor progression through increasing histological grades of malignancy.

Antibodies, Monoclonal↗