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Dive into the research topics where Peter D. Papapetrou is active.

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Featured researches published by Peter D. Papapetrou.


Clinical Endocrinology | 2004

Bone mineral density in hyperthyroidism

Helen Karga; Peter D. Papapetrou; Areti Korakovouni; Fotini Papandroulaki; Antony Polymeris; George Pampouras

objective  To investigate whether previous hyperthyroidism is a cause of permanent secondary osteoporosis.


Journal of Bone and Mineral Metabolism | 2007

Vitamin D deficiency in the elderly in Athens, Greece

Peter D. Papapetrou; Maria Triantaphyllopoulou; Helen Karga; Panagiotis Zagarelos; Kyriakos Aloumanis; Eleni Kostakioti; George Vaiopoulos

Vitamin D deficiency characterized by low 25-hydroxyvitamin D [25(OH)D] levels has been found to be prevalent among the elderly in many regions of the world. To investigate the vitamin status in elderly community-living persons in Athens, we measured 25(OH)D and parathyroid hormone (PTH) in elderly persons and young blood donors during the winter and summer. The changes in these parameters in a subgroup of the elderly were studied longitudinally. The blood donors had mean 25(OH)D levels similar in winter and summer and twice as high in winter compared to the elderly. At the end of the winter, about 20% of the elderly had severe vitamin D deficiency, with 25(OH)D below 25 nmol/l, and only 6.5% could be judged as vitamin D sufficient with values above 80 nmol/l. The situation improved during summer, although 64.8% of the elderly continued to have levels below 80 nmol/l. Mean plasma PTH in the elderly in summer was not different from that of blood donors; however, it was doubled during the winter. Regression of PTH on 25(OH)D demonstrated that PTH starts to rise when 25(OH)D falls below approximately 80 nmol/l. We conclude that severe vitamin deficiency associated with secondary hyperparathyroidism is not uncommon in the elderly in Athens during the winter; it subsides during summer, although only one-third of the elderly population attain vitamin D sufficiency during summer. We found that a threshold value of 25(OH)D exists at approximately 80 nmol/l, below which secondary hyperparathyroidism ensues, as described previously.


Journal of Endocrinological Investigation | 2006

Heterophilic antibodies causing falsely high serum calcitonin values

Peter D. Papapetrou; Antonis Polymeris; Helen Karga; G. Vaiopoulos

Heterophilic antibodies (HA) may interfere in some immunoassays, causing falsely high hormone values, of wich practitioners should be aware when measuring calcitonin (CT) used as tumor marker for medullary thyroid carcinoma (MTC). We studied four patients with thyroid nodules, three of whom underwent surgical neck exploration, after an erroneous diagnosis of MTC because of falsely high serum CT eventually proved to be due to HA. One patient had a lingual thyroid, two autoimmune thyroiditis and the fourth a colloid goiter. The minimal incremental CT response to calcium infusion raised our suspicion of possible false high CT values due to HA. There was no linearity of the CT values obtained by testing serial dilutions of the sera in the CT assay, which employs two monoclonal mouse anti-CT antibodies. Addition of normal mouse gamma globulin eliminated the interference by HA in the sera of two patients. Serum assayed in a polyclonal radioimmunoassay using goat anti-CT antibodies gave normal CT values. Finally, incubation of the sera in Heterophilic Blocking Tubes® (HBT) eliminated the false CT immunoreactivity. A spontaneous change of the CT serum concentrations was noticed in three patients over several months, apparently due to changing titles of HA. We suggest that, in patients a) whose CT response to calcium or pentagastrin infusion is minimal despite high basal CT values, b) with autoimmune thyroiditis and c) in whom an unexpected change in serum CT concentrations occurs, the possibility of spuriously high CT values because of circulating HA should be considered.


Pathology Research and Practice | 2000

Ras oncogenes and p53 tumor suppressor gene analysis in cardiac myxomas

Helen Karga; Panayotis Papaioannou; Maria Karapanni; Konstantina Papadimitriou; Dimitris Priftis; Theodore Voujuklakis; Basiliki Migdou; John N. Nanas; Peter D. Papapetrou

Although ras oncogenes and p53 tumor suppressor gene mutations are implicated in the development of several human tumors, little is known about their role in the pathogenesis of primary cardiac tumors. Paraffin-embedded tissue from 19 cardiac myxomas were investigated for the presence of ras oncogenes and p53 tumor suppressor gene abnormalities. Immunohistochemical analysis was used to identify the accumulation of p21-ras and p53 proteins. A polymerase chain reaction was used to amplify exons 1 and 2 of the ras genes and exons 5 to 8 of the p53 gene. The PCR products were analyzed by single strand conformation polymorphism analysis and by direct DNA sequencing. Three of 19 myxomas showed strong positive staining for the ras p21 protein. In contrast, nuclear p53 was not detectable in any of the myxomas. Among the ras p21 immunopositive myxomas, 2 were heterozygous for a missense point mutation of the K-ras, Gly 12Asp. Further screening of the remaining myxomas showed no mutation or even silent polymorphism in any exon of the ras and p53. The results suggest that although genetic alterations of ras oncogenes and p53 are uncommon events in cardiac myxomas, ras mutations may be involved in the pathogenesis of a subgroup of this type of tumor.


Clinical Endocrinology | 2012

Changes in TNM stage, reoperation and 131‐I ablation rate during the use of newer methods for the preoperative diagnosis of differentiated thyroid carcinoma

Helen Karga; K. Mavroudis; Irene Giagourta; Maria Triantaphyllopoulou; V. Ktena; Georgia Kassi; H. Veloutsou; Peter D. Papapetrou

Objective  To define and discuss the changes of important risk factors and TNM staging over the last 40 years in patients operated on for differentiated thyroid carcinoma (DTC), resulting from the introduction of newer sensitive diagnostic procedures in the preoperative evaluation of thyroid nodules.


Journal of Clinical Neuroscience | 2007

Corpus callosum aplasia in a young patient with a parathyroid adenoma

Kyriakos Aloumanis; Peter D. Papapetrou

A young man with primary hyperparathyroidism due to a parathyroid adenoma and aplasia of the corpus callosum is presented. We hypothesize a possible genetic association of the two pathologies: a proportion of the sporadic parathyroid adenomas are associated with genetic abnormalities of chromosome 11 and in some cases of corpus callosum aplasia, aneuploidy or polyploidy of this chromosome has been described.


Metabolism-clinical and Experimental | 2003

L-thyroxine therapy attenuates the decline in serum triiodothyronine in nonthyroidal illness induced by hysterectomy

Helen Karga; Peter D. Papapetrou; Sakellaris Karpathios; Fotini Papandroulaki; Constantinos N Tsompos; Garyphallia Papaioannou; Kyriakos Aloumanis; Panayotis Papaioannou

It is controversial whether the administration of thyroid hormone to patients with nonthyroidal illness has any beneficial effect. Two groups of patients undergoing abdominal hysterectomy under the same general anesthesia were studied. Group A consisted of 15 women taking chronically l-thyroxine therapy (1.8 mug/kg daily), and group B (control) consisted of 16 apparently healthy euthyroid women taking placebo. Thyroid hormones, cortisol, and interleukin (IL)-6 were measured 1 day before and 1, 2, 3, and 6 days after surgery. Total triiodothyronine (TT(3)) decreased to a significantly greater degree (P <.05) and for a longer period of time in group B than in group A. The significant increase of reverse T(3) (rT(3)) noted early in group B failed to reach the baseline levels until the end of the study, whereas in group A, rT(3) returned to the preoperative values by day 2. Both groups had similar free thyroxine (FT(4)) at baseline. FT(4) increased significantly at day 1 and remained significantly elevated throughout the postoperative period in group B only. Serum TT(4), thyroid-stimulating hormone (TSH), and cortisol did not change significantly in either group. In all patients, IL-6 increased significantly to a peak value at day 1, showing a slow decrease thereafter. A stronger negative correlation was found between T(3) and IL-6 in group B than in group A (r = -.66, P <.0001 v r = -.38, P <.001, respectively) and a strong positive correlation was observed between rT(3) and IL-6 in group B only (r =.57, P <.001). The long-term treatment with T(4) seems to attenuate the decrease of serum T(3), which occurs during the development of nonthyroidal illness postoperatively. The elevation of IL-6 accounted for a greater proportion of the variations of the T(3) and rT(3) in the control group B than in the T(4)-treated group A.


Hormones (Greece) | 2014

The philosopher Socrates had exophthalmos (a term coined by Plato) and probably Graves' disease.

Peter D. Papapetrou

According to a previously published theory, Socrates was afflicted with temporal lobe epilepsy since his childhood. Plato, Xenophon, and Aristoxenus described Socrates as having exophthalmos, probably diplopia, and some symptoms compatible with hyperthyroidism. Using these data, we theorize that Socrates had Graves’ disease. In order to determine a cause of his temporal lobe epilepsy, we speculate that the philosopher also had autoimmune thyroiditis and Hashimoto encephalopathy during his childhood and his epilepsy may have been a sequel to this hypothesized encephalopathy.


Advances in Medicine | 2014

An Average Body Circumference Can Be a Substitute for Body Mass Index in Women

Antonis Polymeris; Peter D. Papapetrou; Georgios Katsoulis

Introduction. Significant correlations between BMI and some body circumferences have been previously reported. In this study we investigated if the average of the sum of eight body circumferences can be a substitute for BMI. Patients and Methods. BMI and eight body circumferences (neck, waist, hip, arm, forearm, wrist, thigh, and ankle) were measured in 193 apparently healthy women aged 20–83, and within a wide range of BMI. Women with BMI ≤ 24.9 were designated as normal, with BMI 25–29.9 as overweight and with BMI ≥ 30 as obese. The relationship of the average body circumference (ABC) of the sum of the eight circumferences, and of each individual circumference with BMI, was evaluated. Results. ABC had the strongest correlation with BMI (r = 0.95, P < 0.001) among all the circumferences tested. Hip circumference had the strongest correlation with BMI (r = 0.89, P < 0.001) among the circumferences of individual body sites. Receiver-Operator Characteristic analysis showed that women with ABC > 44.0 cm could be recognized as having BMI ≥ 25 with sensitivity 90.2% and specificity 88.5%, while women with ABC > 47.1 cm could be diagnosed as having BMI ≥ 30 with sensitivity 92.2% and specificity 91.5%. Conclusion. An average body circumference strongly correlated with BMI in women and can serve as a surrogate of BMI.


Hormones (Greece) | 2013

Maximinus Daia, a Roman emperor who may have had Graves’ disease and died of a thyrotoxic crisis

Peter D. Papapetrou

Evidence is presented that the Roman emperor Maximinus Daia had Graves’ disease and died of severe thyrotoxicosis. The information about this emperor’s terminal illness is drawn from the writings of the 4th century writers Eusebius and Lactantius. An existing statue indicates that the emperor had bilateral Graves’ ophthalmopathy.

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