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Biomedical subjects

Nikolaos Papadopoulos

Publications and source records attributed to Nikolaos Papadopoulos.

15 recordsLinked to original sources

Intraoperative touch imprint cytological analysis of sentinel lymph nodes for the presence of metastases in breast cancer.

BACKGROUND: Imprint cytology may provide a fast and accurate method for intraoperative screening of sentinel lymph nodes, so a decision can be made regarding whether to perform axillary clearance during primary surgery. If the findings are negative, in many cases axillary dissection can be omitted. PATIENTS AND METHODS: 128 sentinel nodes from a cohort of 87 patients that had been identified using technetium-99m nanocolloid as a radioactive tracer and Patent blue dye were dissected for rapid Diff-Quick stained touch preparations. Intraoperative evaluation of sentinel node status by imprint cytology was correlated with histopathological results of permanent sections. Tumor-negative nodes in routine paraffin sections were further investigated with the employment of an anti-cytokeratin antibody. RESULTS: 36 of all sentinel nodes harbored metastases in the paraffin sections, of which 32 were identified by imprint cytology (sensitivity 88.8%). 3 sentinel nodes were positive by imprint cytology and negative by histopathology of the paraffin sections. Comparison of the results of the touch preparations with the final histopathology (hematoxylin-eosin and anticytokeratin antibody stains) demonstrated a sensitivity of 83.3% and a negative predictive value of 92.5%. The specificity and positive predictive value were 100% each. CONCLUSIONS: Touch imprint cytology is potentially useful for intraoperative evaluation of sentinel lymph nodes in breast cancer patients.

Adult↗

Mesna protects intestinal mucosa from ischemia/reperfusion injury.

BACKGROUND: Mesna is a thiol used for the prevention of oxazaphosphorine-induced hemorrhagic cystitis. However, its antioxidant properties on renal and hepatorenal oxidative damage, as well as its mucoprotective effect on the intestinal epithelium have also been shown. The aim of this study was to investigate the potential beneficial effect of mesna on ischemia/reperfusion (I/R)-induced oxidant damage of the intestinal mucosa. MATERIALS AND METHODS: Wistar rats were subjected to intestinal I/R for 30 min, induced by occlusion of the superior mesenteric artery, followed by 60 min reperfusion. Mesna was administered at 3 time points relative to ischemia; 60 min before ischemia, at the onset of ischemia or at the onset of reperfusion. At the end of the study period, jejunal segments were excised and assessed for histopathologic score, apoptotic index using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) assay and glutathione/glutathione disulfide (GSH/GSSG) ratio, as a marker of oxidative stress. RESULTS: I/R caused deterioration of histological characteristics and induction of apoptosis and oxidative stress in the intestinal mucosa. Changes regarding histology and apoptosis were prevented when mesna was administered 60 min before ischemia, but were attenuated when mesna was administered at the onset of ischemia or reperfusion. In all mesna groups, oxidative stress was reduced. CONCLUSIONS: Mesna can ameliorate or even prevent intestinal I/R injury by reducing oxidative stress.

Animals↗

Corticotropin-releasing factor (CRF) receptor type 2 in the human stomach: protective biological role by inhibition of apoptosis.

Corticotropin-releasing factor agonists exert inhibitory effects in stomach functions possibly through peripheral routes. We have previously reported the expression of Urocortin (Ucn) I, an endogenous ligand of both CRF receptor types CRF(1) and CRF(2), in the human stomach. We examined CRF(1) and CRF(2) expression in the same tissue. Using RT-PCR, CRF(2) but not CRF(1) transcripts were detected in RNA extracts from normal human stomach. In addition, immunohistochemical analysis revealed receptor protein in epithelial gastric cells. In order to investigate the biological role of CRF(2) in these cells, an in vitro model was established, using the gastric cancer cell line AGS transiently transfected to express functional CRF(2). The effect of the CRF(2) endogenous ligands CRF, Ucns I and II on the growth parameters of the AGS/CRF(2) was examined. After 1 day of exposure, all three ligands reduced the degree of apoptosis (16%-19%, n = 9, P < 0.05) compared to non-treated controls and this effect was observed for 3 days of treatment. No such effect was detected in non-transfected cells, suggesting mediation through CRF(2) receptors. Administration of CRF, Ucns I and II had no effect on the proliferation rate of AGS/CRF(2) cells or on the release of PGE(2) by them. Our results demonstrate CRF(2) expression in the human gastric mucosa and indicate a physiological role of this receptor type in regulating apoptosis, an important parameter of gastric cell regeneration. Paracrine effects exerted by locally expressed endogenous ligands, such as Ucn I, support a significant role of the peripheral CRF system in gastric physiology. J. Cell. Physiol. 209: 905-911, 2006. (c) 2006 Wiley-Liss, Inc.

Apoptosis↗

Topography-guided surface ablation for forme fruste keratoconus.

PURPOSE: To evaluate the efficacy of customized surface ablation in cases of forme fruste keratoconus. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Eleven eyes of 8 contact lens-intolerant patients with forme fruste keratoconus treated at the Institute of Refractive and Ophthalmic Surgery and the University Eye Clinic Zurich. INTERVENTION: Topography-guided customized surface ablation by means of a scanning spot excimer laser. MAIN OUTCOME MEASURES: Visual acuity, refraction, quality of vision (ghosting), corneal topography including the Zernike parameter Z3. RESULTS: Statistically significant reduction of manifest refractive error, corneal irregularity, and ghosting. The spherical equivalent was reduced by -2.8+/-0.62 diopters (D) (P = 0.0007), the cylinder by 1.34 +/- 0.18 D (P = 0.015), Z3 was reduced by 41% (P<0.001), and all patients had less ghosting compared to their preoperative status. No eye lost > or =1 lines in best spectacle-corrected visual acuity; however, 7 of 11 eyes gained > or = 1 line. CONCLUSION: Topography-guided surface ablation is a promising option to rehabilitate vision in contact lens-intolerant patients with forme fruste keratoconus.

Adult↗

Intraoperative cytological evaluation of Marjolin ulcers.

BACKGROUND: Marjolin ulcers are malignant neoplasia developing in chronic open wounds and pathological scars. A definitive diagnosis is made by histological examination of permanent sections. Frozen section biopsy has been widely used for intraoperative diagnosis and evaluation of surgical excision safety margins. This preliminary study aims to discuss the reliability of a simpler and faster method -- intraoperative cytology -- in the diagnosis of Marjolin ulcers. PATIENTS AND METHODS: Touch or scrape smears of 76 Marjolin ulcers from 22 patients were assessed, and features were compared to the histological appearance of permanent sections. RESULTS: Cytology revealed squamous cell carcinoma (SCC) in 45 ulcers from 11 patients. Histology confirmed SCC in 48 ulcers from 12 patients. No false-positive and one false-negative results were found. Cytology was found to have a 98.7% accuracy, 98% sensitivity and 100% specificity in the intraoperative diagnosis of Marjolin ulcers. CONCLUSIONS: Cytology is a fast and reliable alternative in the intraoperative diagnosis of Marjolin ulcers.

Adult↗

Evidence of haematopoiesis within the developing human diencephalon. Correlations with vertebrate phylogeny.

AIM: The sites of haematopoiesis during human ontogeny can be correlated to the sites where haematopoiesis occurs in vertebrate phylogeny. As haematopoiesis has been described in the diencephalon and pituitary gland of water-inhabiting vertebrates we wanted to find out whether such a phenomenon also occurs in human embryos. MATERIAL AND METHODS: Paraffin-embedded specimens from the diencephalon and pituitary gland of human embryos at the 7th to 22nd gestational week and from adults were investigated by conventional histology and immunohistology for the presence of haematopoietic cells. RESULTS: Cellular accumulations predominantly of erythroid and megakaryocytic lineage were identified in the floor of the developing diencephalon of the 7th/8th gestational week. At the older developmental stages of the 18th to 22nd gestational week loose aggregates of haematopoietic cells within the leptomeningeal spaces adjacent to the hypophyseal infundibulum were detected in 2 out of 7 cases analyzed. CONCLUSIONS: As it has been proposed that lymphohaematopoietic clusters occasionally occur within the brain in bone marrow-less vertebrates as a response to noxious agents, we speculate that this temporal appearance of haematopoietic cell clusters within the diencephalon floor in early human ontogeny could also be due to fetal immunomodulations.

Animals↗

Metachronous extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) and peripheral T-cell lymphoma unspecified: histologic, immunophenotypic, and molecular documentation.

BACKGROUND: Coexistence of B- and T-cell lymphoid malignancies has been reported sporadically. CASE REPORT: A 68-year-old woman developed a lymphoid neoplasm in the large intestine and a second lymphoid neoplasm in the esophagus, 24 months after the diagnosis of the first lymphoma. Immunophenotypic analyses were consistent with extranodal marginal zone B-cell mucosa-associated lymphoid tissue type (MALT type) and peripheral T-cell unspecified lymphomas in the large intestine and the esophagus, respectively. The molecular analysis confirmed the B-clonal genotype of the first lymphoma, and disclosed a biclonal genotype of the second one (composite T- and B-cell lymphoma). No evidence of Epstein-Barr virus (EBV) association was shown in either tumor. CONCLUSION: B- and T-cell neoplasms represent two distinct malignancies rather than progression of the same neoplastic clone.

Aged↗

ALK-positive neutrophil-rich variant of anaplastic large cell lymphoma diagnosed after head trauma.

BACKGROUND: Anaplastic lymphoma kinase (ALK) expression has not been described in neutrophil-rich anaplastic large cell lymphoma (NR-ALCL). CASE REPORT: A 12-year old female with a 4-weeks history of a non-resolving bump over the forehead resulting from injury, was diagnosed of stage IE cutaneous T-cell lymphoma, and radiation was employed. Shortly after completion of therapy, there was progress of the disease on the soft tissue of the right hand, and bone marrow involvement was also found. A fine-needle aspiration of the hand mass was performed, and a diagnosis of CD30+/ALK+ NR-ALCL, was rendered. METHODS: We studied the morphological characteristics of CD30+/ALK+ NR-ALCL using histological methods. A panel of antibodies were used to establish diagnosis and subtyping. In addition EBV status and molecular cytogenetics were determined. CONCLUSIONS: ALK-ALCL arising in the skin represents a single disease with a broad spectrum of morphology; clinicians and pathologists should be aware of this neutrophil-rich (NR) variant with aggressive clinical presentation.

Anaplastic Lymphoma Kinase↗

Efficacy and safety of ibutilide for cardioversion of atrial flutter and fibrillation in patients receiving amiodarone or propafenone.

AIM: The effectiveness and safety of ibutilide (IB) use in patients receiving amiodarone or propafenone for atrial flutter (AFL) and atrial fibrillation (AF) were compared to IB alone. METHODS AND RESULTS: In 104 consecutive patients with AF (65%) or AFL (35%), receiving amiodarone (n = 46), propafenone (n = 30), or no specific antiarrhythmic drug (n = 28), IB was given for cardioversion. Fifteen patients in amiodarone group were loaded with 1.2 g intravenously before IB administration. The mean duration of arrhythmia episode was 23 +/- 65 days, while 85% of patients had structural heart disease. The left ventricle ejection fraction was 57 +/- 10% and the left atrium size was 4.2 +/- 0.6 cm. The conversion efficacy did not differ among groups (62% for amiodarone vs 55% for propafenone vs 64% for IB alone). The QTc intervals were significantly prolonged, at 10 minutes and 30 minutes after IB administration, in amiodarone group (from 449 +/- 88 to 496 +/- 92 ms, 508 +/- 52 ms; P = 0.001) and in the group where IB was used alone (from 434 +/- 45 to 517 +/- 74 ms, 492 +/- 65 ms; P < 0.001), while it remained unchanged in propafenone group (from 464 +/- 52 to 471 +/- 80 ms, 489 +/- 93 ms; P = 0.536). The only predictor of conversion was the presence of AFL (P = 0.009). Five patients developed ventricular tachycardias after IB administration (two in propafenone, one in amiodarone, and two in IB group). CONCLUSIONS: The use of IB in patients receiving amiodarone or propafenone for AFL or AF is equally effective and safe as the use of IB alone. The presence of AFL is the stronger predictor factor for cardioversion.

Adult↗

Biodegradation of phenol by acclimatized Pseudomonas putida cells using glucose as an added growth substrate.

Biodegradation of phenol, a pollutant derived from many industrial processes, was achieved through acclimatized Pseudomonas putida cells. The strategy to overcome the inhibitory effect of phenol on microbial growth involved the addition of glucose, a conventional carbon source. A factorial experimental design was employed in order to optimize the initial phenol and glucose concentrations. The optimum conditions found were applied in 2-lt bioreactors. The development of acclimatized cells and the use of glucose as an added growth substrate resulted in a significant phenol degradation rate of 60.7 mg L(-1) h(-1) with a complete removal of 1200 mg L(-1) phenol.

Biodegradation, Environmental↗

Polymorphous low grade adenocarcinoma of the parotid gland. Cytological, histological and immunohistochemical features and review of the literature.

AIM: Polymorphous low grade adenocarcinoma of the salivary glands (PLGA) is a low grade neoplasm that predominantly occurs in the minor salivary glands. In this site is amenable to biopsy and histologic diagnosis. However, experience with cytological findings in these tumors is limited. We describe the cytology of this entity. EXPERIMENTAL DESIGN: Touch imprint cytology of a primary parotid PLGA is specified and correlated with histology. RESULTS: Smears were hypercellular showing branching papillae, sheets and clusters of uniform cells with bland nuclei, dispersed chromatin and no nucleoli. The cells had a scant to moderate amount of eosinophilic cytoplasm. They formed tubular structures containing hyaline globules. CONCLUSIONS: The cytologic differential diagnosis of PLGA includes adenoid cystic carcinoma, pleomorphic adenoma, and monomorphic adenoma. PLGA should be considered in the differential diagnosis of head and neck tumors, where the cytology suggests on of the above mentioned tumors, even when the clinical findings (involvement of a major salivary gland, lymph node metastasis) is not typical of PLGA.

Adenocarcinoma↗

Pancreatic-polypeptide in the human pancreas: expression and quantitative variation during development and in ductal adenocarcinoma.

AIM: To determine the immunoreactivity of pancreatic-polypeptide (PP) during the development of the human fetal pancreas and ductal pancreatic adenocarcinoma, given that, PP positive cells were demonstrated either into its embryonic anlage or into pancreatic cancer. METHODS: Tissue sections from 15 pancreatic fetal specimens, and equal number of ductal adenocarcinoma specimens, were assessed. RESULTS: The density of positive cells in the primitive exocrine ductal epithelium and endocrine epithelium was significantly higher than the relevant density in the neoplastic pancreatic tissue of mixed (ductal - endocrine) and pure ductal type (p1 = 0.001, p2 < 0.0005, p3 = 0.046 and p4 < 0.0005 respectively). The above values were estimated during the 10th to 12th week. There was no significant difference in the density of positive cells in the mantle zone of the islets from the 13th to the 24th week, and the neoplastic tissue of mixed (p5 = 0.11) and pure ductal type (p6 = 0.23). CONCLUSION: The immunostaining for PP identifies a subgroup of pancreatic ductal adenocarcinomas with a neuroendocrine component, initially considered as pure ductal tumors, and mixed ductal and neuroendocrine tumors. This pattern of expression in neoplasms recapitulates the normal pattern during the embryonal development of the organ, raising the question of therapeutic efficacy of PP and analogues as potential adjuvant treatment of pancreatic cancer.

Adenocarcinoma↗

Prevalence of CD8/CD4 ratio in the fetal thymic parenchyme in Down's syndrome.

AIM: The maturation of most T-lymphocyte precursors takes place within the meshwork of thymic epithelial cells. Different steps of this process can be defined by immunologic phenotyping. The prothymocytes are positive for the terminal deoxynucleotidyl transferase (TdT) and give rise to cortical thymocytes, which express CD1, CD2, CD3, CD5, and both CD4 and CD8. These CD4 and CD8 double-positive cortical thymocytes differentiate into two lineages: CD4+ or CD8+ lymphocytes of the thymic medulla, by the tenth week of gestation. Our study points towards the determination of the CD8 cytotoxic/suppressor capacity of the fetal thymus in Down's syndrome. EXPERIMENTAL DESIGN: A quantitative comparison of T-lymphocytes (CD3, CD4, and CD8) in the thymic parenchyme in embryos after voluntary abortion during 2nd trimester of gestation and embryos with Down's syndrome, respectively, was performed. RESULTS: Our results showed: 1) A statistically significant depletion in the total number of T-cells (CD3 positive) in the cases of embryos with Down's syndrome over those after voluntary abortion, during the second trimester of gestation (p<0.0001, t-test). 2) A significant difference in the CD8/CD4 ratio in the cases of embryos with Down's syndrome, during the second trimester of gestation which was numerically stronger with the progress of fetal development (20th week: p<0.025; 24th week: p<0.01, chi-square). CONCLUSIONS: The occurrence of increased CD8/CD4 ratio in the cases with Down's syndrome, in the second trimester of gestation, underlines the cytotoxic/suppressor property of the thymus in the affected fetuses.

CD4-CD8 Ratio↗