PubMed Health⌕ Search

Biomedical subjects

P Korantzopoulos

Publications and source records attributed to P Korantzopoulos.

15 recordsLinked to original sources
PubMed2006

Oxidative stress in hepatic ischemia-reperfusion injury: the role of antioxidants and iron chelating compounds.

Ischemia-reperfusion (IR) injury is a multifactorial process triggered when the liver or other organs are transiently subjected to reduced blood supply followed by reperfusion. It has been shown that "reactive oxygen species" (ROS) are generated during ischemia and reperfusion and may represent pivotal mediators of the ensuing pathological complications. In some cases, however, moderate production of ROS may exert protective effects, a phenomenon presumably related to "ischemic preconditioning". This review will focus mainly on: a) describing the sources and the biochemical mechanisms of ROS generation during ischemia and reperfusion, b) discussing current developments in understanding the biochemical pathways by which ROS may induce toxic or protective effects, c) critically evaluating the results of previous attempts to counteract the toxic effects of ROS by using a variety of antioxidant and transition metal-chelating agents, and d) if feasible, proposing potential new pharmaceutical agents aimed at ameliorating ROS-inducing deleterious effects during reperfusion. It is concluded that ROS are generated from different sources, at different periods during IR, and may act by a variety of not well understood biochemical mechanisms which ultimately lead to cell damage and tissue failure.

Animals↗
PubMed2005

Propafenone added to ibutilide increases conversion rates of persistent atrial fibrillation.

OBJECTIVE: To assess the effectiveness and safety of pharmacological conversion of persistent atrial fibrillation (AF) with a combined propafenone plus ibutilide regimen. METHODS AND RESULTS: 100 consecutive patients (66 men, mean (SD) age 65 (10) years) with persistent AF (mean (SD) duration 99 (92) days) admitted for elective pharmacological cardioversion were randomly assigned to treatment with either intravenous ibutilide (1 mg plus an additional 1 mg, if required; n = 51) or oral propafenone (600 mg) plus intravenous ibutilide at the same dose (n = 49). Success rates were 41.1% (21 of 51 patients) for ibutilide alone and 71.4% (35 of 49 patients) for propafenone plus ibutilide (p = 0.0044). However, cardioversion occurred earlier in the ibutilide alone group (55 (20) minutes) compared with the combination group (81 (32) minutes, p = 0.0019). A comparable increase in the QTc interval was observed in both groups but one case of sustained torsade de pointes, requiring electrical cardioversion, was observed in the propafenone plus ibutilide group. No other complications were noted during the hospitalisation period. CONCLUSION: Concurrent administration of propafenone plus ibutilide for pharmacological cardioversion of persistent AF is safe and more effective than ibutilide alone.

Administration, Oral↗
PubMed2005

Microscopic polyangiitis complicated by the development of prostate cancer and flutamide-induced hepatitis.

We report a case of a 65-year-old man with microscopic polyangiitis who developed prostate cancer and gastric adenocarcinoma after prolonged oral use of cyclophosphamide. Acute hepatitis with jaundice and marked increase in aminotranferases occurred after 6 months of flutamide treatment for metastatic prostate carcinoma. It is suggested that patients with vasculitis or other autoimmune disorders should avoid prolonged use of cyclophosphamide and other cytotoxic drugs in order to minimize long-term adverse effects, of which the risk of cancer is by far the most important. In patients on flutamide treatment, careful monitoring of flutamide administration with repeated liver function tests should be undertaken, and the drug must be immediately discontinued in patients with abnormal results to avoid progression of liver injury.

Adenocarcinoma↗
PubMed2005

Variation of inflammatory indexes after electrical cardioversion of persistent atrial fibrillation. Is there an association with early recurrence rates?

Inflammation has been recently implicated in the pathophysiology of atrial fibrillation (AF). The aim of this study was to examine the variation of inflammatory indexes during the first week after successful electrical cardioversion of persistent AF. Successive measurements of white blood cell (WBC) count, C-reactive protein (CRP) and fibrinogen levels were performed in 30 cardioverted patients. At the end of the 7-day follow-up period, AF had recurred in 30% of patients. A significant variance was found in serial measurements of fibrinogen levels in the two groups (non-relapse and relapse, p = 0.005). Fibrinogen levels increased significantly in patients who relapsed into AF, but remained stable in patients who remained in sinus rhythm. In the latter patients, CRP values tended to decrease post-cardioversion, but WBC count was significantly lower (p < 0.001) on the 7th day (6083 +/- 1335), compared with baseline values (6648 +/- 1395). The variation of inflammatory indices post-cardioversion might have prognostic implications with regard to sinus rhythm maintenance.

Aged↗
PubMed2005

Physical activity and stroke risk.

Stroke represents a leading cause of morbidity and mortality especially among the elderly people, and therefore the need for effective preventive strategies is imperative. The value of physical activity for stroke prevention is not as well established as for other cardiovascular diseases. Despite some conflicting results, the majority of published studies have demonstrated a negative association between physical activity and stroke risk. In this article, we provide a concise overview of the epidemiological studies that investigate this association as well as a comprehensive analysis of the most relevant underlying pathophysiological mechanisms.

Aged↗
PubMed2004

Subdural empyema and cerebellar abscess due to chronic otitis media.

The infratentorial variety of the subdural empyema, with or without coexisting cerebellar abscess, is a rare clinical entity that carries a high mortality rate. We briefly describe the case of a 49-year-old man presented with severe debility, fever and an obviously neglected chronic otitis media. The patient had refused surgical treatment several months ago. After admission, his level of consciousness began to deteriorate, and the radiological studies showed infratentorial subdural suppuration extending into the right cerebellar hemisphere, along with chronic pyogenic infection of the middle ear and the mastoid process. Radical mastoidectomy was performed first, followed by extensive right posterior fossa craniectomy. The two subdural collections and the cerebellar abscess were successfully evacuated. Subsequently, he received post-operative antibiotic treatment for 6 weeks. At follow-up, 10 months after surgery, his neurological recovery was complete except for a minor residual cerebellar dysfunction on the right. This unusual case highlights that in patients presented with severe intracranial complications of chronic otitis media, early diagnosis and radical surgical intervention may be life saving.

Abscess↗
PubMed2004

Disseminated tuberculosis complicating anti-TNF-alpha treatment.

An unusually large number of cases of tuberculosis, often of miliary or disseminated form, have been reported in patients receiving infliximab therapy for rheumatoid arthritis or Crohn's disease. We describe a patient with rheumatoid arthritis who was treated with infliximab and became systemically ill with Mycobacterium tuberculosis-disseminated infection. Patients who are candidates for treatment with tumour necrosis factor-alfa inhibitors should be evaluated for the presence of latent or active

Antibodies, Monoclonal↗
PubMed2003

Acute rhabdomyolysis due to prolonged exposure to the cold.

Rhabdomyolysis represents an acute skeletal muscle injury and may be accompanied by acute renal failure due to myoglobinuria. This disorder has many potential causes. We describe the case of a 75-year-old man who developed rhabdomyolysis after prolonged exposure to cold but without associated hypothermia. This unusual case highlights that an appropriate investigation for rhabdomyolysis such as serum CK measurement should be performed in patients presenting with a history of prolonged exposure to cold, even in the absence of an obvious precipitating factor.

Acute Disease↗
PubMed2003

Solitary extramedullary plasmacytoma of the maxillary sinus. Case report.

Solitary extramedullary plasmacytomas are rare tumors that often affect head and neck region. Because of the non-specific associated symptomatology, they frequently are misdiagnosed. We briefly describe a 69-year-old woman who developed solitary plasmacytoma in the left maxillary sinus and was initially treated as having sinusitis. We also report the diagnostic work-up that is necessary to establish a correct diagnosis in such cases. This case highlights that an appropriate investigation for neoplastic disease should be performed in patients presenting with persistent symptoms that resemble those of sinusitis, especially if these do not resolve after conservative medical treatment.

Aged↗
PubMed2001

Acute renal dysfunction associated with selective COX-2 inhibitor therapy.

The recent release of the selective cyclooxygenase-2 (COX-2) enzyme inhibitors for the treatment of various inflammatory disorders and pain syndromes has been associated with a clear-cut decrease in adverse gastrointestinal effects. The nephrotoxic effect of selective COX-2 inhibitors has not yet been firmly established. We report a case of reversible acute renal failure due to rofecoxib treatment in an elderly patient with several risk factors associated with traditional nonselective nonsteroidal anti-inflammatory drug (NSAID)-related nephrotoxicity. It is prudent to approach therapy with selective COX-2 inhibitors cautiously and in a fashion similar to traditional NSAID therapy for patients with risk factors that induce prostaglandin-dependent renal function.

Acute Kidney Injury↗
PubMed1997

On the molecular mechanism of metmyoglobin-catalyzed reduction of hydrogen peroxide by ascorbate.

Hydrogen peroxide induces rapid oxidation of metmyoglobin with an apparent second order rate constant, k1 = 3.4 x 10(4) M-1 min-1. The product of this interaction is ferrylmyoglobin with an unstable free radical on the globin moiety. This activated form of myoglobin is able: (a) to initiate the peroxidation of erythrocyte membranes and (b) to form intra- and intermolecular covalent crosslinkings. The presence of ascorbic acid in amounts stoichiometric to H2O2 efficiently prevents all the above processes. Moreover, in the presence of ascorbic acid a cyclic process is taking place leading to H2O2 reduction, ascorbic acid oxidation, and unmodified metmyoglobin formation (reaction 1).

Acetylation↗
PubMedDate not supplied

An epidemiologic study of acute coronary syndromes in northwestern Greece.

Acute coronary syndromes (ACS) represent the most common cause of morbidity and mortality in the Western world. Relative epidemiologic data for Greece, a Mediterranean country, are sparse. The aim of the study was to determine the incidence and the clinical presentations of ACS. Over a 1-year period we conducted a prospective, population-based survey of ACS cases in an isolated area of northwestern (NW) Greece with 170,000 inhabitants. Every patient living in the study area, aged <80 years, without history of coronary artery disease, who presented with symptoms suspicious for ACS and was hospitalized for at least 24 hours was eligible for inclusion in the study. For sudden cardiac deaths, relative information was obtained from the autopsy report or the physician who documented death. Additional information regarding timing and associated conditions was obtained from relatives. The diagnosis and classification of the studied cases was performed according to World Health Organization and European Society of Cardiology criteria. The authors identified 352 patients (265 men, 87 women, mean age 62.5 +/-10 and 68 +/-9.5 years, respectively) with first-appeared ACS (174 non-ST elevation, 105 ST elevation, 73 sudden cardiac deaths). Fifty-six patients with other forms of ischemic heart disease (stable angina, heart failure, and silent ischemia) were not included in the analysis. Moreover, 154 patients with chest pain and normal appearing EGG at rest, normal values for enzymes (CK, troponin), and negative exercise testing, as well as 77 patients with normal findings from coronary angiography studies, were also excluded. The annual incidence for the age group of 30-79 was 39/10,000 inhabitants (60.6 for men and 19 for women). The incidence of ACS increased with age in both sexes and was higher in men even after the age of 70. About one third of the ACS and half of the sudden cardiac deaths occurred in the age group of 70-79. Only 3 patients were successfully resuscitated. ACS are common in this area of NW Greece and the majority of them present in a form amenable to therapeutic manipulations. Twenty percent of patients died suddenly, and a very small percentage of these were successfully resuscitated. Preventive measures and acute management facilities need to be improved, even in a Mediterranean country where the incidence of ischemic heart disease is relatively lower than in northern European countries.

Acute Disease↗