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Biomedical subjects

K Charalabopoulos

Publications and source records attributed to K Charalabopoulos.

At least 37 records · Page 2Linked to original sources
PubMed2005

Consequences of the discontinuation of antihypertensive treatment in successfully treated patients.

Hypertension is probably the most important public health problem in developed countries. Over the last 40 years, an increasing number of hypertensive patients have been treated with various antihypertensive drugs. If the blood pressure (BP) is controlled, the discontinuation of the antihypertensive drug may result either in a relapse of the disease or in the maintenance of normal BP for a long time. In this study, we discuss the available data regarding the consequences of antihypertensive drug withdrawal in successfully treated patients and we suggest guidelines for the application in clinical practice.

Antihypertensive Agents↗
PubMed2005

The role of E-cadherin/catenin complex in laryngeal cancer.

In this review the role of the epithelial E-cadherin/catenin complex in cases of laryngeal cancer is discussed. Cancer of the larynx remains the second most common head and neck malignancy. The E-cadherin/catenin complex expression is abnormal in laryngeal squamous cell carcinomas. Loss or reduction of E-cadherin expression is especially observed in supraglottic larynx cancer in relation with poor histological differentiation and/or lymph nodes metastases. Controversial results in some studies regarding the role of the E-cadherin/catenin complex in various anatomical parts of the larynx have been reported. Further studies are needed to establish the importance of the E-cadherin/catenin complex as a potential biomarker in laryngeal cancer diagnosis and prognosis.

Animals↗
PubMed2005

Genetic models of human cancer as a multistep process. Paradigm models of colorectal cancer, breast cancer, and chronic myelogenous and acute lymphoblastic leukaemia.

Tumour formations arise as a consequence of alterations in the control of cell proliferation as well as with disorders in interactions between cells and their environment that result in invasion and metastasis. Recent advances in understanding the genetic basis of malignant diseases have been dominated by research in colorectal cancer. Genetic alterations of several proto-oncogenes and tumor-suppressor genes (e.g. APC/MCC, RAS, DCC, p53 mutations and/or allelic losses, hyperexpression of c-MYC and RB genes), as well as other genomic alterations, appear at characteristic stages of tumor development and are observed in most neoplasms. Generally, the normal cell has multiple independent mechanisms that regulate its growth and differentiation potential, and several separate events would, therefore, be needed to override these control mechanisms, as well as induce the other aspects of the transformed phenotype, like metastasis. These signals may be either positive or negative, and the acquisition of tumorigenicity results from genetic changes that affect these control points following a multistep mode. Statistics of the frequency of cancer incidence with age in humans indicate that for the genesis of e.g. lung carcinoma, five or six steps are required. Other types of cancers, such as leukemias and sarcomas, probably require quite a different number of rate-limiting changes. One of the best characterized tumours to provide a genetic model is colorectal tumorigenesis. Mutations implicated in breast cancer tumorigenicity are also studied and used as a genetic model in the literature worldwide. Finally, activation of c-abl in chronic myelogenous leukaemia (CML) and acute lymphoblastic leukaemia could also be presented as an example, which provides probably the strongest evidence for the role of proto-oncogenes in human malignancy process.

Breast Neoplasms↗
PubMed2004

Left atrial myxoma prolapsing into the left ventricle. Case report and review of the literature.

Cardiac myxomas are rare tumors which may present differently. Left atrial myxoma is an entity from anatomopathological and clinical aspects. To the best of our knowledge, only 2 cases of infected left atrial myxomas treated surgically have been reported in the last 6 years. Herein, we present a patient with a left atrial myxoma prolapsing into the left ventricle in the diastolic phase, which was infected with Streptococcus viridans. Combined therapy, consisting of surgical management and antimicrobial therapy, was used. Clinical presentation, diagnosis and treatment are reviewed.

Anti-Bacterial Agents↗
PubMed2004

Direct endobronchial metastasis is a rare metastatic pattern in breast cancer.

Breast cancer is the most common cancer in women. Lungs represent a common site of metastases in breast cancer cases. Lung parenchyma, pleura, lymphatics, regional lymph nodes as well as trachea with bronchi are sites of metastatic involvement of the lungs in patients suffering from breast cancer. Endobronchial metastasis, especially of the direct type, is a very rare metastatic pattern in this type of cancer. We describe a case of endobronchial metastasis in a 59 years old Caucasian woman who had had a radical mastectomy 2 years before her present admission because of breast cancer. She was admitted to Joannina University hospital complaining of non-productive cough. Chest X-rays showed atelectasis of the right upper pulmonary lobe. Flexible fiberoptic bronchoscopy findings, cytologic examination of the bronchial excretions as well as the histological examination of the excised during bronchoscopy tumour specimen, strongly suggested a breast adenocarcinoma. Hereby, review data from the literature is given in brief.

Breast Neoplasms↗
PubMed2004

Fatal meningitis due to Listeria monocytogenes in elderly patients with underlying malignancy.

Adult patients with malignancies are considered to be at a high risk for Listeria monocytogenes meningitis. The Microbiology Laboratory's database of the University Hospital of Ioannina, Greece, was searched for cases of L. monocytogenes during the period from January 1990 to December 2002. Listerial meningitis occurred in three patients: one with brain tumour, one with chronic lymphocytic leukaemia, and one with non-Hodgkin's lymphoma. All the patients were older than 70 and they were actively receiving therapy for their malignancy. L. monocytogenes type 4b was isolated from blood and cerebrospinal fluid. All were treated with ampicillin and gentamicin, but they died shortly after the initiation of the treatment. Experience with the three present cases indicated the high mortality rate due to listerial meningitis in this immunosuppressed population. So, listeriosis should be suspected in patients with meningitis and underlying malignancy. Since meningitis due to L. monocytogenes is not distinguishable clinically from other types of bacterial meningitis, it is recommended to cover Listeria in the initial empirical therapy of bacterial meningitis in immunosuppressed patients.

Aged↗
PubMed2004

Infectious mononucleosis, diffuse pneumonia and acute respiratory failure in an elderly woman.

Infectious mononucleosis (IM) is a benign disease and is frequently associated with mild respiratory symptoms. The pulmonary manifestations rarely dominate the clinical picture. We report a case of an older adult patient with IM who developed diffuse pneumonia and acute respiratory failure. The diagnosis of IM was confirmed serologically, whereas other possible causes of pneumonia were excluded in this study. Pulmonary manifestations of IM are discussed, and the atypical features that may be seen in older adults are simultaneously reviewed.

Acute Disease↗
PubMed2004

Eosinophilic gastroenteritis: presentation of two patients with unusual affect of terminal ileum and caecum with manifestations of acute abdomen and literature review.

Eosinophilic gastroenteritis is a rare disease; the long-term personal history with digestive symptoms and the course of the disease with relapses and remissions is the key for the disease to be suspected. Endoscopy, CT scan and sonographic studies may provide important indirect signs of the disease and in combination with histological examination the diagnosis can be achieved. The administration of corticosteroids is an important factor for the treatment or the remission of the disease. In this study two cases with unusual location of the disease, on the terminal ileum and caecum, are presented and a literature review is attempted. The disease process, clinical and laboratory findings as well as the surgical approach used are described. Eosinophilic gastroenteritis is a very rare disease with its surgical complications. The disease is a non-surgical disease, thus presurgical diagnosis is important because the entity discussed can be under control by conservative treatment. A high disease suspicious index must be kept in the physicians' mind.

Abdomen, Acute↗
PubMed2004

Giardia lamblia intestinalis: a new pathogen with possible link to Kikuchi-Fujimoto disease. An additional element in the disease jigsaw.

A 16-year-old Caucasian girl of Albanian origin was admitted to the hospital complaining of intermittent fever (38 degrees C) for a week, nausea, vomiting, and abnormal laboratory findings (elevated serum aminotransferases levels AST/ALT 77/40 U/l and erythrocyte sedimentation rate 80 mm/first hour, as well as leukopenia 2.5 x 10(3)/mm3), which were found in a blood examination. Physical examination revealed slight hepatomegaly and splenomegaly, as well as cervical and axillary lymphadenopathy. A diagnostic open lymph node biopsy was performed and Kikuchi-Fujimoto disease (KFD) was established based on the characteristic histological pattern. Other abnormal laboratory findings were C-reactive protein 6.8 mg/dl and serum lactate dehydrogenase 900 U/l. Her history included a diarrhoea syndrome 2 months before the present admission, during the summer holidays, for which she was treated with metronidazole. At that time, characteristic cysts of giardia lamblia intestinalis were observed in the stools. Herein, we present this case hypothesising that the protozoal infection caused by the giardia lamblia intestinalis was probably triggering an immune response leading to KFD. The patient's age in combination with this firstly reported protozoal pathogen, as a triggering agent leading to KFD, consist a very interesting originality. Additionally, some review data is also given.

Adolescent↗
PubMed2004

Cell proliferation and cell cycle control: a mini review.

Tumourigenesis is the result of cell cycle disorganisation, leading to an uncontrolled cellular proliferation. Specific cellular processes-mechanisms that control cell cycle progression and checkpoint traversation through the intermitotic phases are deregulated. Normally, these events are highly conserved due to the existence of conservatory mechanisms and molecules such as cell cycle genes and their products: cyclins, cyclin dependent kinases (Cdks), Cdk inhibitors (CKI) and extra cellular factors (i.e. growth factors). Revolutionary techniques using laser cytometry and commercial software are available to quantify and evaluate cell cycle processes and cellular growth. S-phase fraction measurements, including ploidy values, using histograms and estimation of indices such as the mitotic index and tumour-doubling time indices, provide adequate information to the clinician to evaluate tumour aggressiveness, prognosis and the strategies for radiotherapy and chemotherapy in experimental researches.

Cell Cycle↗
PubMed2004

Integrin receptors in primary lung cancer.

In the present review recent data regarding the role of integrins--an important category of adhesion molecules mediating interactions among cells and components of the extracellular matrix--in lung cancer development is discussed. Investigations have shown that down-regulation of alpha3 integrin subunit may contribute to enhanced tumorigenicity of c-myc-overexpressing small cell lung carcinoma, while the loss of an integrin expression is correlated with recurrence in node-negative lung carcinoma. Increased expression of alpha1beta1 and alpha2beta1 integrins have been shown to be positively correlated with increased metastatic ability in squamous cell carcinoma. alpha3beta1 integrin is a most critical integrin for pulmonary development and epithelium integrity and its reduced expression in small cell lung cancer is probably related to the increased aggressiveness of this type. Pulmonary cancer cells generally express fewer integrin receptors than the normal epithelium. Additionally, since the ability of malignant cells to interact with extracellular matrix components is thought to be important, integrin dependent migration of lung cancer cells is a crucial process.

Animals↗
PubMed2004

Expression patterns of cyclins D1, E in laryngeal epithelial lesions: correlation with other cell cycle regulators (p53, pRb, Ki-67 and PCNA) and clinicopathological features.

The expression of cell-cycle progression molecules cyclin D1 and cyclin E were immunohistochemically examined in a series of 64 squamous cell invasive carcinomas of the larynx, 10 in situ carcinomas, 34 cases of dysplasia, 11 papillomas and 23 cases of keratosis. The results of their expression were compared with two cell-cycle implicated tumor suppressor proteins p53 and pRb as well as with two proliferation associated indices PCNA and Ki-67 in an attempt to elucidate their potential role in the pathogenesis and progression of these lesions. Nuclear staining for cyclin D1 and E (>5% positive cells) was observed in 19% and 39.7% of the laryngeal carcinomas, respectively. Significantly elevated levels of cyclin D1 and E in invasive laryngeal carcinomas compared with in situ carcinomas were revealed (p=0.045 and p=0.0003, respectively). High levels of cyclin D1 and E expression were correlated with increased Ki-67 score (p=0.037 and 0.017 respectively). A significant positive correlation between cyclin D1 and E was also detected in carcinomas (p=0.018). Decreased levels of cyclins D1 and E in the group of in situ carcinomas compared with those of dysplastic cases and papillomas were also observed. In the dysplastic lesions cyclin D1 expression was correlated with pRb expression (p=0.02). In the cases of keratosis cyclins D1 and E expression were correlated with pRb (p=0.002 and p=0.036, respectively), while cyclin D1 was associated with PCNA (p=0.008) and Ki-67 score (p=0.009). The prognostic significance of cyclins D1, E in determining the risk of recurrence and overall survival with both univariate (long-rang test) and multivariate (Cox regression) methods of analysis showed no statistically significant differences. We conclude that the expression of cyclins D1 and E in squamous cell carcinomas of the larynx does not seem to have a prognostic significance. In addition, their expression may be involved in the development of laryngeal lesions, implicated in cell proliferation, with other cell cycle related proteins, probably by different molecular pathways.

Adult↗
PubMed2004

Cadherin superfamily of adhesion molecules in primary lung cancer.

Cadherins are Ca(2+-)dependent cell-cell adhesion molecules which interact with intracellular proteins called catenins. Cadherins are the most interesting adhesion molecules and among them most important is epithelial E-cadherin. Loss of the function or/and the expression of any of the elements of E-cadherin/catenins complex make the cell incapable to adhere resulting to a loss of the normal architecture of tissues. Reduced, absent or disorganised expression of E-cadherin has been found in several carcinomas, including lung cancer. Soluble E-cadherin found in serum from patients with lung cancer could be a tumor marker, while alterations observed in non-small cell lung cancer probably play a role in manifestation of a malignant phenotype. Reduced expression of E-cadherin is a key event in tumorgenicity and metastasis and possible therapeutic strategies are based on that conclusion. In addition, E-cadherin has a role as a marker of differential diagnosis between bronchioloalveolar carcinoma and conventional pulmonary carcinoma as well as between mesothelioma and metastatic pulmonary adenocarcinoma. Small cell lung cancer cells express several types of cadherins too. In conclusion, many studies are in process and it is very possible that soon some cadherins will be used as useful biomarkers and theraupeutic targets in cases of primary lung cancer.

Adenocarcinoma↗
PubMed2003

Lung, pleural and colon actinomycosis in an immunocompromised patient: a rare form of presentation.

Actinomycosis is caused by gram-positive filamentous organisms of the genus Actinomyces, which may spread through trauma. Most commonly, it is a cervicofacial disease due to dental infection or a thoracic disease secondary to aspiration of foreign bodies. Primary abdominal infection usually follows some form of mucosal disruption. Any organ of the human body may be involved so that a wide range of symptoms may be present. We report a rare form of actinomycosis involving the lung, pleura and colon concomitantly in an immunocompromised patient. A fine needle aspiration from a lung lesion detected the characteristic sulfur granules, and a pleural effusion culture confirmed the diagnosis. Clinical manifestations and treatment are discussed. Actinomycetes are rarely opportunistic agents in immunocompromised patients; thus the disease deserves special attention in those patients.

Actinomycosis↗
PubMed2003

Inhibition of benzo(a)pyrene-induced carcinogenesis by vitamin C alone and by vitamin C/vitamin E and selenium/glutathione.

The reduction on peroxidation caused by benzopyrenes by some naturally occurring antineoplastic agents was studied in this experimental work. Inhibition/reduction of experimental carcinogenesis induced by benzo(a)pyrene by vitamin C alone and by vitamin C/vitamin E and selenium/ glutathione was attempted in 224 female Wistar rats divided in four groups. Injected with 10.08 mL benzo(a)pyrene, the animals were treated with some naturally occurring substances like vitamin C alone and a combination of anticarcinogens. By calculating the carcinogenic potency of benzo(a)pyrene and the anticarcinogenic potency of substances used as well as histological examination of developed tumors and survival time of treated animals, it was found that vitamin C exerts a significant anticarcinogenic effect of 8.3 units and that the combination of the two anticarcinogens used produced a significant prolongation of the animals survival time with anticarcinogenic potency of 22.1 and 22.2 units, respectively. This is considered a potent anticarcinogenic effect. The question of an additional supportive administration of such agents complementary to the conventional cancer chemotherapy in humans is raised. Of course, further studies are needed.

Animals↗
PubMed2002

Antitumour and toxic effects on Wistar rats of two new platinum complexes.

BACKGROUND: Cancer chemotherapy in humans based on metal complexes started at the clinical level in the late 1970s with the use of cisplatin, which forms intra-strand cross-links with DNA. METHODS: Two new platinum complexes of cis-geometry with the amino acids inosine (ino) and l-alanine (ala), Pt(ino)2Cl2 and cis-[Pt(NH3)2(ala)](NO3), respectively, were synthesized and pure samples were obtained by means of flash chromatography. These complexes were tested on benzo(a)pyrene-induced tumours in Wistar rats to detect their antitumour and toxic effects. RESULTS: There was a statistically significant prolongation of the mean survival time of the animals in the two groups tested (272 +/- 18 days and 246 +/- 26 days, respectively) compared to the control group (195 +/- 22 days) (P < 0.001). Toxic effects included a decrease in leucocyte cell count, mild haemolysis, mild haematuria, mild hepatotoxicity, elevated body temperature and hair loss. All of these effects were reversible after drug discontinuation. CONCLUSIONS: The two new platinum complexes described here appear to have an effective antitumour activity without severe toxicity when tested on Wistar rats.

Animals↗