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O Papadopoulos

Publications and source records attributed to O Papadopoulos.

At least 19 recordsLinked to original sources
PubMed2007

p53 codon 72 Pro homozygosity increases the risk of cutaneous melanoma in individuals with dark skin complexion and among noncarriers of melanocortin 1 receptor red hair variants.

BACKGROUND: p53 has a common polymorphism at amino acid 72, encoding either arginine or proline. p53Arg and p53Pro exhibit differences in various biological activities, such as cell-cycle arrest and induction of apoptosis. Numerous epidemiological studies have examined the role of this polymorphism in several human malignancies, including cutaneous cancers, with contradictory results. OBJECTIVES: To investigate the germline frequency of p53 codon 72 polymorphism in malignant melanoma in a Mediterranean population, and to examine possible associations with various clinicopathological factors. METHODS: In this hospital-based case-control study we used allele-specific polymerase chain reaction for p53 codon 72 genotyping in blood specimens from 107 Greek patients with sporadic cutaneous melanoma and 145 healthy controls. RESULTS: After adjustment for age, sex and phototype the Pro/Pro genotype was associated with increased risk for cutaneous melanoma compared with the Arg/Arg genotype (adjusted odds ratio, OR 3.17, 95% confidence interval, CI 1.03-9.78). This correlation was more pronounced in subjects with phototypes III or IV (adjusted OR 9.56, 95% CI 1.56-58.46), dark skin (adjusted OR 10.96, 95% CI 1.64-73.28), dark eyes (adjusted OR 8.86, 95% CI 1.69-46.52) and dark hair (adjusted OR 3.17, 95% CI 1.01-9.95), and among noncarriers of melanocortin 1 receptor gene (MC1R) red hair polymorphisms (adjusted OR 2.99, 95% CI 1.02-8.78). CONCLUSIONS: p53 codon 72 Pro/Pro genotype could be a risk factor for the development of melanoma in the Greek population, especially in subgroups with darker skin pigmentation, as well as among noncarriers of the MC1R red hair polymorphic variants.

Adult↗
PubMed2006

Temozolomide in combination with celecoxib in patients with advanced melanoma. A phase II study of the Hellenic Cooperative Oncology Group.

BACKGROUND: There is now increasing evidence that a constitutive expression of cyclooxygenase (COX)-2 plays a role in the development and progression of malignant epithelial tumors. Expression of COX-2 is seen in 93% of melanomas, as determined by immunohistochemistry. Temozolomide (TMZ) has demonstrated activity against melanoma and has been investigated as single agent or in combination. We designed a phase II study to assess the efficacy and toxicity of the combination of TMZ and celecoxib (a COX-2 inhibitor) in patients with advanced melanoma. PATIENTS AND METHODS: From January 2003 to July 2004, 52 patients were enrolled in the study. Nineteen patients were M1a, six M1b and 27 M1c. Patients received TMZ 200 mg/m(2) per day p.o. for 5 consecutive days every 4 weeks and celecoxib 400 mg b.i.d. p.o. for a maximum of six cycles. Celecoxib was continued until progression. RESULTS: The median age was 63 years. There were 29 males and 23 females. Among 50 assessable patients, there were 11 (21.5%) objective responses including five complete responses and six partial responses. Twenty patients (38.5%) had stabilization of their disease, and 19 (36.5%) progressed. The median time to progression was 4.6 months and the median survival 9.5 months. Twenty-two patients (41.5%) completed all cycles of treatment. Median relative dose intensity of TMZ was 0.99 (range 0.6-1.2). Most commonly seen toxic effects included anemia (27.5%), neutropenia (17.5%), thrombocytopenia (33%), nausea/vomiting (75%), gastrointestinal (52%) and fatigue (46.5%). One patient discontinued due to severe toxicity. COX-2 was determined by immunohistochemistry and was expressed in all cases. CONCLUSION: The combination of TMZ and celecoxib is safe and potentially effective in the treatment of metastatic melanoma. Randomized studies are needed to explore the role of celecoxib in combination with chemotherapy or as maintenance treatment in these patients.

Antineoplastic Agents, Alkylating↗
PubMed2006

Lip defects due to tumor excision: apropos of 899 cases.

Reconstructive surgery of the lips after resection of tumors requires a complete understanding of the anatomy of this region. Most lip cancers remain localized and grow slowly, with a propensity for superficial rather than vertical spread. From January 1983 to December of 2005, 899 patients underwent reconstructive surgery for skin tumors involving the lips. SCCs were the most frequent skin tumors on male patients whereas BCCs were most common on the female patients. The lower lip was the anatomic zone most frequently involved in our series. Preoperative evaluation of the patients was performed in all cases. In the last five-years, we have performed preoperative fine needle aspiration (FNA) biopsy of the tumor. The FNA sample was then examined by ThinPrep technique (Cytolyt; Cytyc, Co, Boxborough, MA, USA). In our series, from the 550 patients who had a five-year follow-up we observed 62 recurrences of the primary tumor. The five-year recurrence rate was 11.28%. The aim of this retrospective study is to report our experience in the treatment of lips tumors with selective combination of treatment modalities.

Adult↗
PubMed2006

Genetic variability of encephalomyocarditis virus (EMCV) isolates.

In order to evaluate the variability of encephalomyocarditis virus (EMCV), field isolates originating from different European regions and inducing different clinical pictures in pigs have been molecularly characterised. The regions targeted were the poly(C) tract, a part of the 5'-UTR (360 nucleotides), the Leader gene (201 nucleotides), the complete capsid coding region (2502 nucleotides), the 2A gene (403 nucleotides), the end of the 3D polymerase gene (305 nucleotides) and the 3'-UTR (123 nucleotides). Analyses have also been performed on a virulent field isolate, which had been subjected to serial passages in vivo and in vitro resulting, in the case of the in vitro passaged virus, in attenuation, as demonstrated by animal experiments. The present study shows that different clinical pictures, such as acute fatal myocarditis or reproductive failure, may not only be caused by EMCV isolates which are genetically diverse but also by the same isolate. Thus no correlation could be demonstrated between genotype and clinical disease. However, the European isolate which showed the highest genetic divergence also gave rise to a more complex clinical picture. Despite EMCV having been isolated from cases of acute fatal myocarditis in pigs in certain areas of the world for many years, clinical disease, including a variety of clinical pictures and pathogenicity, has only been recognised in Europe since 1986 and thus it can be considered an emerging disease in this region. These findings, associated with the reported phenotype changes of the virus under environmental changes (passages), along with its wide distribution among vertebrate species (including higher primates), shows the validity of considering EMCV as a potential pathogen for recipients in xenotransplantation.

3' Untranslated Regions↗
PubMed2005

First partial characterisation of small ruminant lentiviruses from Greece.

Small ruminant lentivirus (SRLV) infections are widespread in Greece, but SRLVs have never been isolated and characterized. In this study, we present the sequence of a 574-nucleotide (191-amino acid) region of the gag gene of SRLV strains from four sheep and one goat from a single geographic area of Greece. All five sequences appeared to be closely related at both nucleotide (2.1-14.2% variation) and deduced amino acid (1.6-4.2% variation) level. Greek SRLV strains were closer to ovine prototypic strains (average divergence 16.8%) than to the caprine strain CAEV-Co (21% divergence). By amino acid composition, the Greek SRLVs were on the average more than twice as distant from CAEV-Co as from other ovine strains. Phylogenetic analysis suggested that Greek strains segregate into a unique group, separate from, but related to, other ovine prototype sequences.

Amino Acid Sequence↗
PubMed2005

Reconstructive surgery for kidney transplant recipients.

Many decades have passed since the first kidney transplantation, which is now the most common organ transplant performed worldwide. Despite the impressive advances, some patients may develop posttransplant complications that require proper management and treatment. The plastic and reconstructive surgeon, among others, may be called on to help resolve a number of reconstructive problems present in the immunosuppressed kidney recipients. This study presents our experience with 41 kidney recipients who needed plastic surgical treatment. Patients were placed into one of three study groups according to the type of posttransplant surgical condition. Group 1 included 17 patients with posttraumatic wound healing problems; group 2, 17 patients with skin tumors; and group 3, 7 patients with other posttransplant surgical complications. Only two of these patients had early posttransplant wound dehiscence; the remaining patients suffered late complications. In conclusion, the kidney recipient can successfully undergo minor or major reconstructive procedures. The possibility of surgical problems arising during the early posttransplant period presents increased complication rates, possibly due to high immunosuppressive drug levels.

Cadaver↗
PubMed2005

Immunophenotypic analysis of the p53 gene in non-melanoma skin cancer and correlation with apoptosis and cell proliferation.

BACKGROUND: Sunlight precipitates a series of genetic events that lead to the development of skin cancers such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The p53 tumour suppressor gene, which plays a pivotal role in cell division and apoptosis, is frequently found mutated in sunlight-induced skin tumours. OBJECTIVE: To investigate the immunoreactivity of the p53 gene in non-melanoma skin cancers and to correlate its expression with apoptotic and cell proliferation markers. METHODS: We analysed 35 non-melanoma tumours including 19 BCCs and 16 SCCs from sun-exposed skin areas. p53 protein expression was studied immunohistochemically using the DO7 monoclonal antibody against wild-type and mutant p53 forms. The percentage of p53-immunopositive nuclei was measured by image analysis. Cell proliferation and apoptosis were also assessed by image analysis following Ki-67 immunostaining and application of the TUNEL method on paraffin sections, respectively. RESULTS: The percentage of p53-expressing cells varied from 3.5 to 90 in BCCs (median value 54.4%) and from 3.7 to 94 in SCCs (median value 40.3%). The mean value of Ki-67-positive cells was comparable in both groups of tumours with a mean value of 40.6% in BCCs and 34.6% in SCCs. Conversely, the TUNEL assay showed sporadic staining of apoptotic cells within the tumours with a mean value of 1.12% in BCCs and 1.8% in SCCs. p53 protein expression was correlated positively with cell proliferation (r = 0.75, P = 0.000001) and negatively with apoptosis (r = -0.23, P = 0.05). CONCLUSION: p53 immunoreactivity was high in the majority of the skin carcinomas examined and correlated positively with cell proliferation and negatively with apoptosis. The p53 protein overexpression appears to be related to an inactivated protein resulting from mutations of the p53 gene or other unclear molecular mechanisms.

Aged↗
PubMed2004

Effect of challenge dose and age in experimental infection of pigs with encephalomyocarditis virus.

Two experiments were performed to compare the severity of encephalomyocarditis virus (EMCV) infection in pigs. The pigs were challenged with the Greek myocardial strain, at different ages and with different doses. In the first experiment, nineteen susceptible pigs, 40 days old, were divided into three groups and were experimentally infected with 10(6) TCID(50), 10(4) TCID(50) or 10(2) TCID(50) of the Greek EMCV strain. In the second experiment, 10 susceptible pigs, of either 20 or 105 days, were divided into two groups according to age and were experimentally infected with 10(6) TCID(50) of the Greek EMCV strain. In addition, five piglets, each one the same age as its experimental group, were used as uninfected controls. No clinical signs were observed after infection, except a transient temperature rise in some pigs. Another important observation was the difference in mortality between groups. The survival rate of the 40-day-old pigs was inversely related to the viral dose. In these pigs, a positive association between the viral dose and the severity of macroscopical and histopathological lesions of the heart was also evident. Viral isolations from various organs of the challenged 40-day-old pigs increased with the increasing dose level. When challenged with 10(6) TCID(50) of EMCV, there was no difference in the fatality rate of the 20- and 40-day-old pigs, but none of the 105-day-old pigs died. The severity of the macroscopical and the histopathological heart lesions was inversely related to the age of the pigs. Furthermore, viral isolations from the various organs were higher in 20- and 40-day-old pigs than in the older ones. In 40-day-old pigs, neutralizing antibodies linearly increased as the dose increased. These antibodies were consistently lower in 20-day-old pigs. Viraemia, and nasal and faecal excretions were detected in all groups and lasted 1-3 days, except for the 105-day-old pigs whose symptoms lasted for an additional day.

Age Factors↗
PubMed2004

Minor species/minor indications: legal provisions, definition criteria and policies to be considered.

The problem of availability of immunological products in minor species and minor indications/uses is complex and should be well defined. Data for species are available, but not for minor uses. "Case-by-case" decisions should be avoided, as far as possible. The following categories can be recognized: (a) a vaccine has not been authorized anywhere; (b) a vaccine is authorized for major species/indications only; (c) an authorized vaccine exists in another Member State and (d) a vaccine has been withdrawn. Old, well established products, with limited data for an updated dossier could be the problem in categories "c" and "d". Proposed measures and incentives include: "cascade" (not recommended), human orphan-like drug policy, provisional authorization, acceptance of bibliographical data (if justified), procedural and financial assistance. Standards of quality, safety and efficacy cannot be minimized, but specific tests can be considered.

Animals↗
PubMed2003

Evaluation of cytology in the diagnosis of acute canine monocytic ehrlichiosis (Ehrlichia canis): a comparison between five methods.

The purpose of this study was the comparison of the diagnostic sensitivity between buffy coat (BC), peripheral blood (PB), lymph node (LN), bone marrow (BM) and short-term culture (P-D) cytology that has been based on the detection of Ehrlichia canis morulae, in the acute phase of canine monocytic ehrlichiosis (CME). Their cellular localization, total numbers and microscopic differentials were also investigated. The highest sensitivities were achieved after evaluating 1000 oil immersion fields (OIFs) in BC (66%) and an equal number in LN (60.9%) smears, separately or together (74%). The morulae were more often detected into lymphocytes than monocytes. The highest total number of morulae (n=143) were found in P-D smears. Finally, to avoid false positive diagnoses, platelets, lymphocytic azurophilic granules, lymphoglandular bodies and phagocytosed nuclear material should not be confused with the morulae.

Animals↗
PubMed2003

Full dose paclitaxel plus vinorelbine as salvage chemotherapy in anthracycline-resistant advanced breast cancer: a phase II study.

This phase II trial studied the efficacy and toxicity of full dose paclitaxel plus vinorelbine, as salvage chemotherapy in patients with metastatic breast cancer resistant to anthracyclines. Patients received vinorelbine (30 mg/m2) followed 1 hour later by full dose paclitaxel (175 mg/m2) every 3 weeks for a maximum of 8 cycles or until disease progression. Because of the heavy pretreatment of the patients, prophylactic granulocyte-colony stimulating factor (5 microg/kg) was administered daily for 5-10 days. To minimize potentially cumulative neurotoxicity due to both agents, amifostine was given prior to chemotherapy. Thirty-four patients: 8 with tumors primary resistant and 26 with tumors recurring within 3-6 months after anthracycline treatment, were evaluable for efficacy and toxicity. Objective responses occurred in 11 patients [32%; 95% confidence interval (CI): 16.3-47.7%), all partial responses. Responses were observed in lung and liver. The median response duration was 4 months (range 3-7), median time to progression was 5 months (range 3-9) and median overall survival was 8 months (range 4-24). Neutropenia was dose limiting (35% grade 3-4 toxicity). The left ventricular ejection fraction, measured and followed in 18 patients, fell less than 20% below baseline level in 9 patients (50%), but only one patient developed congestive cardiac failure. The paclitaxel-vinorelbine regimen was moderately tolerated and moderately effective in poor prognosis breast cancer patients with visceral metastases and tumors resistant to anthracyclines. The combination at these doses and schedules should be considered in the design of regimens for advanced breast cancer.

Adult↗
PubMed2001

Experimental infection of pregnant ewes with enteric and abortion-source Chlamydophila abortus.

Two groups of pregnant ewes were experimentally infected oronasally in midpregnancy. A faecal and an abortion-source isolate of Chlamydophila abortus were used. They were derived from a healthy ewe from a flock with no history of abortion, and from an aborted foetus in a farm with enzootic abortion. As assessed by modified Ziehl-Neelsen (MZN) staining, egg culture, antigen ELISA, the Clearview test and immunohistochemistry, inoculation resulted in placental and/or foetal infection in all ewes. Histopathology revealed placentitis in two and four ewes inoculated with the enteric or abortion-source isolate, respectively, in addition, these samples were immunohistochemically positive for chlamydial antigen. All six ewes infected with the enteric isolate and five of seven ewes infected with the abortion-source isolate showed evidence for a serological response by an indirect ELISA or CFT. Neither chlamydiae nor lesions were detected in the placentae and lambs of the uninfected control ewes, which remained seronegative. Our results suggest that enteric C. abortus can be associated with placental and foetal lesions in sheep.

Abortion, Veterinary↗
PubMed2001

A randomised, blinded, placebo-controlled clinical trial with allopurinol in canine leishmaniosis.

A total of 45 non-uremic dogs, with clinical signs indicating leishmaniosis, entered the study. Diagnosis was confirmed by indirect immunofluorescence assay (IFA) on serum and polymerase chain reaction (PCR) on bone marrow samples. The dogs were randomly allocated into Group A (n=37) that received allopurinol (10mg/kg B.W., per os, twice daily) for 4 consecutive months, and Group B (n=8) that were placebo-treated. Clinical signs were scored just before and at monthly intervals throughout the study period, in a blinded and independent fashion. Complete blood count, serum biochemistry profile, urinalysis, lymph node and bone marrow parasitology, IFA and enzyme-linked immunosorbent assay (ELISA) serology and bone marrow PCR were carried out at the beginning and at the end of the trial. A total of three Group A and one Group B dogs died of end stage kidney disease that developed during the trial. In Group A animals that endured the trial there was a significant improvement in the general body condition, conjunctivitis, peripheral lymphadenopathy, splenomegaly, masticatory muscle atrophy, ulcerative stomatitis, epistaxis, exfoliative dermatitis, cutaneous ulcerations, blepharitis and nasodigital hyperkeratosis. The same observation was made for anemia, lymphopenia, hyperproteinemia, hyperglobulinemia, hyperphosphatemia, increased alkaline phosphatase activity and the low albumin/globulin ratio. By contrast, no improvement of any kind was seen in Group B dogs. Lymph node and bone marrow parasite numbers were significantly decreased in Group A animals. In Group B, that occurred only in the lymph nodes. Apart from remission of clinical signs and restoration to normal of clinicopathological abnormalities, allopurinol did not eliminate Leishmania organisms, as the PCR result on bone marrow was still positive in all the dogs that finished the trial.

Allopurinol↗
PubMed2001

Bluetongue virus diagnosis of clinical cases by a duplex reverse transcription-PCR: a comparison with conventional methods.

A duplex reverse transcription polymerase chain reaction (RT-PCR) assay for the detection of bluetongue virus (BTV) in clinical samples was developed. This assay, which detects the highly conserved S10 region of BTV, was assessed for sensitivity and application as a rapid and dependable diagnostic tool by comparison with standard assays of virus detection, such as virus isolation in embryonated chicken eggs and cell culture. Simultaneous detection of BTV and host beta-actin RNAs minimizes the possibility of false negative results. The sensitivity of the assay was found to be equal to five cell culture infectious dose (CCID(50)) units and its specificity was confirmed as no RT-PCR product was detected with RNAs from two closely related orbiviruses, i.e. epizootic haemorrhagic disease virus (serotypes 1, 2 and 318) and African horse sickness virus, serotype 9, or RNAs from uninfected BHK-21 cells and blood samples from uninfected sheep or goats. In this study, 36 blood samples from naturally infected mixed flocks of sheep and goats were examined. Seventeen animals were identified as BTV-positive by RT-PCR, whereas only 13 were found positive by virus isolation in embryonated chicken eggs and nine by cell culture assays. These results indicate that the duplex RT-PCR could be a useful technique for monitoring BTV infection in the field.

Animals↗
PubMed2001

Evaluation of ultrastructural changes associated with encephalomyocarditis virus in the myocardium of experimentally infected piglets.

OBJECTIVE: To evaluate the ultrastructural changes and localization of encephalomyocarditis virus (EMCV) and viral pathogenesis in the myocardium of experimentally infected piglets. ANIMALS: Eight 20-day-old piglets. PROCEDURE: Six piglets were inoculated oronasally with 5 ml (10(6) median tissue culture infective dose/ml) of EMCV suspension, and 2 were used as uninfected controls. Piglets were euthanatized or died between postinoculation days 1 and 3. Samples of heart tissue from all piglets were evaluated histologically, by virus isolation, and by use of immunohistochemistry and electron microscopy. RESULTS: All infected piglets had gross or microscopic lesions of interstitial myocarditis. immunohistochemically, EMCV antigen was detected in the cytoplasm of cardiac muscle cells, Purkinje fibers, and endothelial cells and in the nucleus of cardiac muscle cells and Purkinje fibers. Ultrastructural lesions were characterized by degeneration and necrosis of cardiac muscle cells and Purkinje fibers. Virus was present intracytoplasmically in cardiac muscle cells, Purkinje fibers, and endothelial cells of capillaries and intranuclearly in cardiac muscle cells. The cell membranes of the Purkinje fibers and endothelial cells had distinct protrusions that contained virus particles. In control piglets, no lesions were found, and no EMCV antigen was detected. CONCLUSIONS: Localization of EMCV intracytoplasmically or intranuclearly in various myocardial cells may well reflect the sites of viral proliferation. The presence of virus particles in cell membrane protrusions and in vacuoles within the lumen of capillaries indicates that virus is released not only by disintegration of the host cell but also via exocytosis.

Animals↗
PubMed2000

Detection of sheep poxvirus in skin biopsy samples by a multiplex polymerase chain reaction.

The development of a multiplex polymerase chain reaction (PCR) method with amplification of capripoxvirus in a single-step procedure from skin biopsies using three primer pairs, two specific for capripoxvirus and one specific for alpha-tubulin is described. A sensitive multiplex PCR was achieved by optimization of parameters such as the primer concentrations, magnesium and dNTPs concentrations. False negative results that sometimes arise due to inhibitors of DNA amplification may be avoided by the inclusion in the assay of alpha-tubulin primers. The results reported on 42 skin biopsies from sheep suspected to have poxvirus infection, indicated that the assay could monitor simultaneously DNA extraction from skin biopsy samples and allow improved detection of capripoxvirus within 24 h of specimen receipt in the laboratory.

Animals↗