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Biomedical subjects

M Mavrikakis

Publications and source records attributed to M Mavrikakis.

At least 37 records · Page 2Linked to original sources
PubMed1997

Immunocytochemical detection of P-glycoprotein in the management of malignant effusions.

P-glycoprotein (P-gp), a cell membrane protein, has been found in multidrug-resistant cancer cells. A total of 104 smears from patients with breast-cancer-associated pleural effusions and ovarian-cancer-related peritoneal effusions were studied for P-gp with the antibody C-219 and the avidin-biotin-immunoperoxidase method. Samples were taken before and 3 and 7 days after intracavitary bleomycin therapy and reaccumulation of effusion was assessed at 30 days. Smears that were P-gp-negative by the 7th day were associated with a good 30-day response to bleomycin in the majority of cases, while P-gp-positive smears were associated with a significant reaccumulation of fluid at 30 days. P-gp status is a valuable prognostic indicator of response to intracavitary bleomycin treatment in effusions from breast or ovarian cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Electrophysiologic abnormalities of cardiac function in progressive systemic sclerosis.

The heart has been generally recognized as a target organ in progressive systemic sclerosis. Noninvasive studies have assessed the incidence and prognostic importance of cardiac arrhythmias in these patients. However, detailed exploration of the function of impulse formation and the conduction system of the heart in these patients has never been reported. Therefore, invasive electrophysiologic studies were performed in 30 patients with systemic sclerosis, all of whom had neither obvious cardiac involvement nor cardiac arrhythmias, and in 32 subjects with no evidence of heart disease, who served as a control group. Corrected sinus node recovery time in patients with systemic sclerosis was significantly longer (P < .001) than in the control group, as was the HV interval (P < .05). Of the 30 patients with systemic sclerosis, 10 had an HV interval of 60 ms or longer. In four patients with systemic sclerosis, the recorded AH interval exceeded 125 ms. The intra-atrial conduction time tended to increase to a significant degree (P < .05) in patients with systemic sclerosis. The interatrial conduction time was much longer (P < .001), and the maximal conduction delay to the atrioventricular junction and to the distal coronary sinus was much greater in the patients with systemic sclerosis than in the control group (P < .001 for both). Supraventricular tachyarrhythmias were induced in 15 patients with systemic sclerosis versus 3 control group subjects (P < .001). With respect to corrected sinus node recovery time, AH and HV intervals, atrial vulnerability, and ventricular tachycardia, 3 of the 30 patients with systemic sclerosis had abnormal findings in one of these parameters and 14 had abnormalities in more than one. These results suggest that a broad spectrum of electrophysiologic abnormalities is present in patients with systemic sclerosis, which can be revealed only by invasive studies. Furthermore, this study provides additional support for the hypothesis that diffuse myocardial involvement is characteristic of scleroderma patients, since a number of these patients showed more than one electrophysiologic defect.

Adolescent↗
PubMed1996

Expression of insulin-like growth factor-I receptor and transferrin receptor by breast cancer cells in pleural effusion smears.

Smear preparations were made from cells harvested from pleural fluid from 90 patients with breast cancer and stained for transferrin receptor (TRFr) and insulin-like growth factor-I receptor (IGF-Ir) using an immunocytochemical technique. The results were correlated with those from 36 benign effusions smears. In malignant smears from the breast cancer cases TRFr was demonstrated in 84.4% of the cellular deposits and IGF-Ir in 91.1%. TRFr was demonstrated in two (11%) of the tuberculous effusion smears and in six (100%) effusions from patients with collagen disease. IGF-Ir was not demonstrated in any of the smears from patients with benign disease. The sensitivity and specificity of TRFr staining were 84.4% and 77.7%, respectively, and for IGF-Ir staining were 91.1% and 100%, respectively. The underlying metabolic changes in the tumour cells which give rise to positive staining with these markers are discussed.

Adenocarcinoma↗
PubMed1996

Retinal toxicity in long term hydroxychloroquine treatment.

OBJECTIVE: To report clinical experience from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who were receiving recommended doses of hydroxychloroquine for more than six years, and were monitored for evidence of hydroxychloroquine related retinopathy every six months. METHODS: A prospective (and continuing) evaluation was made of the potential retinal toxicity of hydroxychloroquine in a cohort of 360 Greek patients followed for RA and SLE, 58 of whom have received long term treatment ( > six years). Fundoscopy, colour vision tests, dark adaptation tests, visual field testing, automated perimetry, and electroretinogram were performed every six months. RESULTS: Among 58 patients receiving hydroxychloroquine for more than six years, two relatively young women (3.5%), one treated for RA and the other treated for SLE, developed characteristic hydroxychloroquine related toxic retinal lesions after cumulative doses of 700 g (6.5 years) and 730 g (8 years) of hydroxychloroquine, respectively. Bilateral visual acuity was 6/6 and 6/7.5, respectively; both patients had normal colour perception. Despite an early diagnosis and cessation of treatment, permanent visual field paracentral scotomata in both patients, and persisting lesions in fluorescein angiography in the patient with SLE, were observed at 4.5 and 3 years of follow up, respectively. No other specific cases of hydroxychloroquine related retinopathy have to date been identified in the remaining 302 patients. CONCLUSION: Cases of irreversible, hydroxychloroquine related retinopathy in patients who did not receive overdoses have not been reported previously. The present observations in two relatively young patients should raise our concern regarding the long term usage of an increasingly popular medication in rheumatology practice.

Adult↗
PubMed1992

Proarrhythmic effects of reactive hypoglycemia.

A patient with refractory atrioventricular nodal reentry tachycardia is reported in whom it was possible to document that reactive hypoglycemia was the trigger for aggravation of arrhythmia. Over a period of 6 years, a series of electrophysiological studies revealed that, when the patient was in a hypoglycemic state, initiation of tachycardia was easy and most importantly that tachycardla termination by extra-stimulus pacing always failed. Furthermore, atrial fibrillation was inducible or spontaneously occurred only when the blood glucose level was reduced by IV insulin administration.

Blood Glucose↗
PubMed1992

Small airways dysfunction in systemic sclerosis. A controlled study.

A debate exists regarding the importance of small airways disease in systemic sclerosis, while smoking seems to have a major effect on the exact prevalence. In order to evaluate small airways dysfunction (SAD) in a pure systemic sclerosis population, we performed pulmonary function studies in 31 nonsmoking patients and 31 age- and sex-matched nonsmoking control subjects. Patients' FVC, TLC, and Dco mean values were significantly lower compared with the corresponding values of the controls (p less than 0.05), while there was no difference in MEF25, RV, and RV/TLC. Seven (22.6 percent) of 31 patients and four controls (a nonsignificant difference) had evidence of SAD, namely a maximum expiratory flow at 25 percent of vital capacity (MEF25) less than 60 percent of predicted. Positive correlation (p less than 0.001) was found between MEF25 and FEV1/FVC in the patients. Moreover, no differences were found in abnormal lung function patients with and those without SAD in demographic, clinical, roentgenologic, and serologic features and results of pulmonary function tests. These findings suggest that SAD in our patients is not a characteristic and early manifestation of systemic sclerosis and that, when present, it is not correlated with the severity of the pulmonary involvement in scleroderma.

Female↗
PubMed1990

Electrophysiologic studies of the heart in patients with rheumatoid arthritis.

We investigated the electrophysiological properties of the heart in patients with definite or classical rheumatoid arthritis using programmed electrical stimulation techniques. Twelve patients with rheumatoid arthritis and without evidence of organic heart disease or arrhythmia detectable with serial electrocardiograms and 24-hour ambulatory electrocardiographic monitoring were compared with 12 control subjects. Stimulation was performed from the high right atrium and right ventricular apex at a drive cycle length of 600 msec and the recording sites included high right atrium, atrioventricular junction and distal coronary sinus. There was no statistically significant difference in the corrected sinus node recovery time between the study and control group of patients. Similarly, no differences from normal were found in the AH and HV intervals or in the atrial and ventricular refractoriness, whereas the atrioventricular nodal effective refractory period was higher in patients with rheumatoid arthritis, compared with the control group (338 +/- 38 vs 286 +/- 29, P less than 0.02). The atrial conduction time during basic cycle length had a tendency to increase from high right atrium to atrioventricular junction in the study group and reached statistical significance from high right atrium to coronary sinus (92 +/- 15 vs 74 +/- 14, P less than 0.05). Electrophysiologic differences between the study and control patients also included a greater increase in maximal intraatrial (40 +/- 13 vs 27 +/- 16, P less than 0.05) and interatrial conduction delay (54 +/- 16 vs 31 +/- 12, P less than 0.01) of early premature stimuli in patients with rheumatoid arthritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Thyroid and parathyroid response to subtotal thyroidectomy.

Hypocalcemia occurring a few days after total subtotal thyroidectomy has been attributed either to parathyroid insufficiency or to calcitonin release. To investigate this matter further, we measured serum calcium, phosphate, T3, T4, TSH, parathormone (PTH), calcitonin (CT) and cAMP, in 27 women aged 23 to 63 years, before and also 3 and 7 days after subtotal thyroidectomy for multinodular nontoxic goiter. Ca, T3 and T4 decreased, whereas TSH increased appropriately to the decrease in T4 and T3. There was no increase in PTH appropriate to the Ca decrease. In contrast, PTH, cAMP and CT showed statistically unsignificant tendency to decrease. It was concluded that hypocalcemia after thyroidectomy is not due to CT release, but rather to a relative PTH insufficiency.

Adult↗
PubMed1985

Unilateral ureteric ligation in diabetic rats: a pathologic and morphometric study.

We studied the combined effect of unilateral ureteral ligation on the morphology and pathology of the contralateral kidney in normal and streptozotocin induced diabetic rats. In the diabetic group that underwent ligation of the right ureter the weight and volume of the left kidney was far greater, the tissue specific gravity far lower, while the percentage of affected glomeruli was significantly greater compared with control rats and those undergoing only ureteric ligation.

Animals↗
PubMed1983

Cerebrospinal fluid cyclic adenosine 3',5'-monophosphate in cases of severe cerebral ischemia and meningitis.

The concentration of cyclic adenosine 3',5'-monophosphate (cAMP) in cerebrospinal fluid was measured in 45 samples from 45 subjects, one sample per subject. 12 of the studied persons were (control group) neurologically normal, 11 were suffering from acute cerebral ischemia with deep coma, and 22 from meningitis of different types. The mean value obtained in the control group was 21.4 +/- (SEM) 3.3 nmol/l, in the group of acute cerebral ischemic attack with deep coma it was 7.00 +/- 0.81 nmol/l and in the group of meningitis 5.5 +/- 0.4 nmol/l. These values are significantly lower than the control group (p less than 0.001). These low levels, observed in the two groups of patients, may be attributed to the altered cAMP metabolism in the central nervous system because of deep coma and bacterial infections.

Adolescent↗
PubMed1980

The cerebrospinal fluid C4 complement component in different meningeal and neurological diseases.

The C4 complement component was measured in CSF from 10 patients without CNS involvement (controls) and 71 with various meningeal and neurological diseases. Serum C4 was also measured in the control group and in 46 of the 71 neurological patients. A significant increase of CSF C4 was observed in all neurological diseases with meningeal involvement independent of the causative agent. Inversely, serum C4 values were within normal limits. Increased CSF C4 with normal serum levels might indicate increased diffusion across the blood-brain barrier, decreased ability for immunocomplex production or increased local production.

Brain Diseases↗