Biomedical subjects

C Simopoulos

Publications and source records attributed to C Simopoulos.

At least 37 records · Page 2Linked to original sources

PubMed2003

Prognostic significance of HLA-DR antigen in serous ovarian tumors.

The antigens encoded by the major histocompability complex (HLA-DR) are cell glycoproteins that play a fundamental role in the regulation of the immune response. The prognosis of ovarian cancer is dependent on the histological type and on the clinical stage at diagnosis. Our study reports the value of HLA-DR antigen as a prognostic marker of ovarian serous adenocarcinoma. We studied 31 cases of serous ovarian cystadenoma, 12 cases of serous ovarian borderline cystadenoma, and 39 cases of well-differentiated cystadenocarcinoma for HLA-DR monoclonal antigen. We also studied the T helper marker (CD4) in the tumor stroma of the relevant cases, given that it is now known that the dependence of immune responsiveness on the class II antigens reflects the central role of these molecules in presenting antigen to T helper cells. HLA-DR was expressed in 20 of 31 cystadenomas (64.5%), 4 of 12 borderline tumors (33.3%), and in 10 of 39 invasive carcinomas (25.6%). CD4 was expressed in 9 of 31 cystadenomas (29%), 5 of 12 borderline tumors (42%), and in 26 of 39 invasive carcinomas (67%). There was a statistically significant difference for the two examined antigens in cystadenomas ( p<0.001) and invasive carcinomas ( p<0.001), whereas there was no statistical difference in borderline tumors ( p<0.5). The results showed decreased expression of HLA-DR and increased expression of CD4 as the lesion progressed to malignancy. The aberrant expression of HLA-DR by epithelial cells of cystadenomas, of borderline tumors, and of invasive adenocarcinomas agrees with the hypothesis of the adenoma/adenocarcinoma sequence. The immune attraction mechanism by low HLADR signaling seems to be of minor importance in the malignant and metastatic potential of serous ovarian tumors.

CD4 Antigens↗

PubMed2003

Endotoxinemia in the portal and the systemic circulation in obstructive jaundice.

Endotoxinemia in patients with obstructive jaundice is linked to acute renal failure and sepsis and remains a major cause of complications during postoperative treatment. The current study examines the mechanisms of endotoxinemia in the portal and the systemic circulation in obstructive jaundice. As an experimental model of the disease we used rabbits subjected to sham operation. Serum total bilirubin aminotransferases and endotoxin concentrations were determined at 2, 5, 8, and 13 days after operation. Endotoxin concentrations were estimated by the limulus lysate endotoxin test. A high frequency of portal or systemic endotoxinemia is observed in obstructive jaundice, but no difference between endotoxinemia levels in the portal and systemic circulation was observed.

Animals↗

PubMed2003

Vascular endothelial growth factor (VEGF) expression in operable gallbladder carcinomas.

AIM: To investigate the angiogenic and prognostic role of vascular endothelial growth factor (VEGF) in operable gallbladder carcinomas. METHODS: Sixty patients with early gallbladder carcinomas, treated with surgery alone, were investigated immunohistochemically for the expression of VEGF, thymidine phosphorylase (TP) and new blood vessel formation. The results were correlated with clinico-pathological features and prognosis. RESULTS: An increased VEGF secretion in gallbladder carcinomas was significantly associated with increased angiogenesis but not with patients survival, although high angiogenesis did relate with poor prognosis. TP was also associated with angiogenesis, but only the combined VEGF/TP expression was associated with unfavourable survival. Histological grade was another independent factor of prognosis. CONCLUSION: Both VEGF and TP expression are associated with high rate of angiogenesis, a factor directly associated with prognosis. The combined expression of these angiogenic factors confer a particularly poor post-operative outcome, speculature.

Adult↗

PubMed2003

Fine-needle aspiration cytology of a para-aortical solitary plasma-cell tumor.

Extramedullary plasma-cell tumor (EMP) is a very rare disease and mainly arises in the head and neck area. An EMP arising in the paraaortical space was diagnosed by fine needle aspiration cytology and immunocytochemistry, in a 48-year-old male. Smears were cellular and showed dissociated monomorphic plasma cells. Immunocytochemistry demonstrated monoclonal expression of kappa-light immunoglobulin chain and CD38 positivity. Cytomorphology and immunocytochemical profile allowed a definitive diagnosis of plasmacytoma.

Aorta↗

PubMed2003

Pre- and postsurgical biomagnetic activity in malt-type gastric lesions. A case report.

PURPOSE: To evaluate the biomagnetic activity of a low-grade mucosa-associated lymphoid tissue (MALT-) type gastric lymphoma, and to determine if this procedure could be an adjunct to endoscopic ultrasonography (EUS) in the assessment of the disease pre- and postsurgically. MATERIAL AND METHODS: A 47-year-old female with a 2-year clinical history of a low-grade MALT-type gastric lymphoma associated with Helicobacter pylori was examined. The disease showed no histologic remission after eradication of the H. pylori infection and subsequent treatment with chemotherapy and the patient was classified as stage II EA. A decision for surgical resection was made. Biomagnetic waveform recordings were made in the target area before and after surgery and the Fourier analysis of these recordings was performed. RESULTS: The gastric lymphoma biomagnetic waveforms showed high amplitudes (1.8 pT) before and low amplitudes (0.6 pT) after resection. The corresponding Fourier analysis demonstrated that the maximum spectral power of the presurgical measurement was elevated (mean 235 +/- 847 pT2/Hz) compared with that obtained postsurgically (mean 725 +/- 89 pT2/Hz). The difference was of statistical significance ( p < 0.0001, t-test). CONCLUSION: Biomagnetic monitoring of gastric lymphoma, which is an entirely new diagnostic modality, could be a supplement to EUS for assessing remission or persistence of disease with medical treatment during follow up.

Female↗

PubMed2003

Hypoxia inducible factor 1alpha and 2alpha overexpression in inflammatory bowel disease.

AIMS: Hypoxia inducible factors 1alpha and 2alpha (HIF1alpha and HIF2alpha) are hypoxia regulated transcriptional factors, which control the expression of a variety of genes responsible for angiogenesis, glycolysis, and the inhibition of apoptosis. Because angiogenesis and tissue regeneration are integral components of the inflammatory process, this study was designed to investigate the role of HIFalpha molecules in inflammatory bowel disease. METHODS: Surgical specimens from patients with active ulcerative colitis (UC) and Crohn's disease (CD) were assessed immunohistochemically for HIF1alpha and HIF2alpha reactivity, and the expression of these molecules was compared with the expression of the angiogenic factors thymidine phosphorylase (TP), vascular endothelial growth factor (VEGF), and VEGF-KDR activated vasculature. The vascular density of the lesions was also assessed using anti-CD31 immunostaining. RESULTS: HIF1alpha was expressed focally (epithelial cells, stromal fibroblasts, and myocytes) in both UC and CD, whereas HIF2alpha was expressed focally in UC and diffusely in CD. TP expression was uniformly positive in both diseases. VEGF expression was absent in CD, and weakly positive in UC. The VEGF-KDR reactivity of the submucosal vasculature was only slightly increased in UC and CD compared with normal tissue. The inflammatory cells stained with HIF2alpha and TP in all cases, but the reactivity was generalised in CD and focal in UC. In both diseases, vascular density was significantly higher than that seen in normal tissue. CONCLUSIONS: The discordant expression of HIF2alpha and VEGF in CD suggests an inherent deficiency of the intestine to respond to various stresses by the induction of VEGF. This finding should be investigated further.

Adult↗

PubMed2003

Phytobezoars as a cause of small bowel obstruction associated with a carcinoid tumor of the ileocecal area.

Carcinoid tumors are slowly growing malignant neoplasms associated with an indolent clinical course. About 60% of such tumors are located within the gastrointestinal tract. We describe an unusual case of small bowel obstruction associated with a carcinoid tumor of the ileum. A 70-year-old woman was presented with abdominal pain, vomiting, and clinical signs of mechanical bowel obstruction. X-ray and CT-scan of the abdomen showed hydroaeric levels and the presence of intraluminal hyperdense "stones", presumably of gallbladder origin. A diagnostic laparotomy revealed that a large part of the terminal ileus was edematous, with prominent evidence of intestinal loop adhesions. The edematous part of the ileum was resected. Incision of the intestinal wall revealed a 2-cm soft mass at 8 cm from the ileocecal valve, where the presence of ten fruit pits obstructed the intestinal cavity. Histopathological examination confirmed the diagnosis of a carcinoid tumor. An interesting case of small-bowel obstruction with a double cause is presented: an ileal carcinoid and fruit pit bezoars. The pathophysiology of the obstruction is discussed.

Aged↗

PubMed2003

Prognostic significance of HLA-DR antigen in dysplasia, carcinoma in situ and invasive carcinoma of the gallbladder.

OBJECTIVE: Prognosis of gallbladder carcinoma is poor. The two most important factors having the greatest effect on survival are pathologic stage of disease and histologic grade of the tumour. Our study points towards the value of HLA-DR antigen in the prognosis of gallbladder carcinoma. DESIGN: Thirty one cases of dysplasia of the gallbladder, 12 cases of carcinoma in situ, and 39 cases of invasive carcinoma for the detection of HLA-DR monoclonal antigen were studied. T helper (TH) marker (CD4) in the tumour stroma of the relevant cases was also studied, given that it is now known that the dependence of immune responsiveness on the class II antigens reflects the central role of these molecules in presenting antigen to TH cells. SETTING: Pathology Departments of Drama General Hospital and Ippokration Hospital of Salonica in twelve years period (1990-2002). RESULTS: HLA-DR was expressed in 20 of 31 dysplasias (64.5%), four of 12 in situ (33.3%), and in 10 of 39 invasive carcinomas (25.6%). CD4 was expressed in nine of 31, dysplasias (29%), five of 12 in situ (42%), and in 26 of 39 invasive carcincomas (67%). CONCLUSIONS: The results showed decreased expression of HLA-DR and increased expression of CD4 as the lesion progressed to malignancy. The aberrant expression of HLA-DR by epithelial cells of dysplasias, of carcinomas in situ and of invasive carcinomas agrees with the hypothesis of the dysplasia-carcinoma in situ sequence as the usual route for the development of invasive carcinoma. The immune attract mechanism by low HLA-DR signalling seems to be of minor importance in the malignant and metastatic potential of the gallbladder, epithelial tumours.

CD4 Antigens↗

PubMed2003

Nucleolar organizer regions (NORs). Their significance in the determination of the origin of the lymphoid vessels.

AIM: The aim of this study is the evaluation of the cellular activity of the embryonal mesenchyme in order to investigate if the primitive lymph vessels are derived from clefts of the mesenchyme or from capillary offshoots from the endothelium of the veins. For this reason we applied the quantitative estimation of nucleolar organizer regions (NORs) in the endothelial cells of the lymph and blood vessels, as well as in the mesenchymal cells that surround these vessels. METHODS: Our material consisted of the histological sections from the proper mesenterium of 30 embryos in different stages of development (10th, 12th, 15th, 20th, 23th and 30th week). RESULTS: A statistically significant difference in the average AgNORs value in the endothelial (ANOVA, p<0.0001) and the mesenchymal cells (ANOVA, p<0.0001) between lymph vessels, blood vessels at close and blood vessels at distant regions (10th, 12th, 15th week) was found. There was no statistically significant difference of the average AgNORs value in the endothelial (ANOVA, p=0.55) and the mesenchymal cells (ANOVA, p=0.49) between lymph vessels, blood vessels at close and blood vessels at distant regions (20th, 23th, 30th week). CONCLUSION: The above results suggest that the development of the lymph vessels follows that of the blood vessels. Furthermore, the intense protein synthesis that is expressed by means of NORs in the mesenchymal cells surrounding lymph vessels from the 10th to the 15th week of development is an additional proof of the view that the primitive lymph vessels are derived from clefts into the embryonal mesenchyma and not from capillary offshoots of the endothelium of the blood vessels.

Gestational Age↗

PubMed2003

Detection of chromosome 1p deletion using FISH on meningioma touch imprints suggest a region outside chromosome 22 as important in tumor recurrence.

BACKGROUND: Atypical and anaplastic meningiomas tend to recur and to invade adjacent brain, bone, and skin. They can also metastasize to extracranial organs such as the lung, liver, or bone causing death. The classic genetic abnormality is loss in chromosome 22. Recent reports have indicated that allelic deletion of chromosome 1p is associated with malignant progression of meningiomas. METHODS: Cytogenetic analysis of 4 meningiomas was performed using double target fluorescent in situ hybridization and focusing on chromosomes 1 and 22. The meningioma series included 4 patients whose tumors were histologically benign. RESULTS: One patient's tumor had recurred. FISH was performed on 500 nuclei/tumors. All our cases showed a loss of chromosome 22q while only 1 meningioma showed an additional loss of chromosome 1p, and this was the recurred one. CONCLUSIONS: The results of this study support the existence of tumor suppressor gene(s) on 1p associated with recurrence in meningiomas and suggest that status of chromosome 1p by FISH may assist physicians in predicting prognosis of patients affected by this tumor. However more in-vestigation is needed in this direction, as our re-sults refer to a small number of subjects studied.

Adult↗

PubMed2003

Spontaneous pneumomediastinum: is a chest X-ray sufficient?

Spontaneous pneumomediastinum (SPM) is an uncommon disease defined as a non-traumatic presence of free air in the mediastinum, without underlying disease. We present a 13-year- old boy who was previously in a perfect health, who was presented with subcutaneous cervical emphysema, dysphagia, chest and neck pain. The chest roentgenogram revealed the presence of subcutaneous emphysema without any other abnormal findings. A computer tomography (CT) scan was obtained, and this confirmed the existence of subcutaneous cervical emphysema and also the presence of pneumomediastinum. The child's progress was uneventful and after 6 days he was discharged from the hospital in excellent clinical condition. We propose that chest CT is useful, in less obvious cases of SPM, to detect the free air in the mediastinum and probably SPM is underdiagnosed in clinical practice in the young people.

Adolescent↗

PubMed2003

Fetal thymic medulla functional alterations in Down's syndrome.

AIM: Although the thymus is usually considered a specifically T cell organ, occasional mature B lymphocytes, B cell germinal centres and rarely plasma cells can be found in this organ, particularly in children. Ultrastructural studies have shown that these lie outside the epithelial enclosure and within the perivascular spaces of the medulla, the corticomedullary junction and septa, and this has led to a concept of 2 functional compartments of the thymus, namely an intraepithelial compartment and an extraepithelial (perivascular) compartment. These cells do not originate from the thymus but enter the organ via the bloodstream, at the 16th week of gestation. Our study points towards possible alterations in the functional histology of this lymphoid organ associated with immunization. METHODS: A quantitative comparison of B lymphocytes in the thymic medulla in embryos after involuntary abortion during the 1(st) and 2(nd) trimester of gestation and embryos with Down's syndrome, respectively, was performed. RESULTS: Our results showed: 1) A statistically significant difference in the number of B cells together with infrequent primary follicles in the cases of embryos with Down's syndrome over those after voluntary abortion, during the 20(th) week of gestation (p=0.013). 2) No statistically significant difference in the number of B cells in both categories during the 1(st) trimester of gestation (p=0.34) and the 24(th) week of gestation (p=0.14). CONCLUSION: The occurrence of increased number of B cells along with primary follicles in the cases with Down's syndrome, in the 2(nd) trimester of gestation imply that the thymic medulla - at least part of it - works and behaves as a peripheral lymphoid organ receiving mature lymphocytes, and turning them from inactive to immunoefficient cells, in the affected fetuses.

B-Lymphocytes↗

PubMed2002

Laparoscopic cholecystectomy in a patient with previous open cholecystostomy.

We report the case of a successful elective interval laparoscopic cholecystectomy in a patient with a previous tube cholecystostomy that had been performed surgically 8 weeks earlier for an attack of acute calculous cholecystitis. At surgery, the major omentum was adherent to the right lateral abdominal wall, completely covering the liver edge, the gallbladder, and the inserted tube. The gallbladder and the tube within it were dissected free from the abdominal wall and the greater omentum, the cholecystostomy tube was removed, and the operation was completed successfully without any further difficulties.

Aged↗

PubMed2002

An unusual cause of delayed presentation of laparoscopic common bile duct injury.

We describe an unusual case of a laparoscopic common bile duct (CBD) injury that presented with cholangitis 2 years after an apparently uneventful laparoscopic cholecystectomy. Preoperative ultrasound and endoscopic retrograde cholangiography suggested choledocholithiasis, showing proximal and intrahepatic duct dilatation with an inability to relieve the obstruction. At surgery, a lateral injury of the CBD wall with partial wall loss was found, adherent to an amorphous pigmented mass with the appearance of a knitted fabric causing CBD obstruction. The CBD was successfully reconstructed with a Roux-en-Y end-to-side hepaticojejunostomy, where the end of the Roux loop was anastomosed to the lateral CBD defect.

Aged↗

PubMed2002

Serum E-cadherin concentrations and their response during laparoscopic and open cholecystectomy.

BACKGROUND: Elevated serum levels of the cell adhesion molecule E-cadherin have been associated with the presence of tissue injury and inflammation. We compared soluble E-cadherin response during laparoscopic and open cholecystectomy. METHODS: The E-cadherin response to surgery was studied in 16 patients undergoing laparoscopic cholecystectomy and 12 patients undergoing open cholecystectomy. Serum E-cadherin levels were measured by an enzyme immunoassay (ELISA) preoperatively, 10 and 30 min after the commencement of surgery, and at 6 and 24 h following the operation. RESULTS: Serum E-cadherin levels decreased progressively during laparoscopic cholecystectomy; their concentrations at 24 h after surgery were significantly lower when compared with preoperative values. In the open cholecystectomy group, serum E-cadherin levels did not differ from preoperative values at any time point. Serum E-cadherin concentrations at 24 h after surgery and the cumulative E-cadherin response were significantly higher in the open cholecystectomy group than in the laparoscopic group. CONCLUSION: Compared with open cholecystectomy, the cumulative E-cadherin response is significantly reduced following laparoscopic cholecystectomy.

Cadherins↗

PubMed2002

Laparoscopic cholecystectomy in a patient with situs inversus totalis and previous abdominal surgery.

Situs inversus totalis is a rare congenital defect that can present difficulties during laparoscopic surgery due to the mirror-image anatomy. We report a patient with symptomatic cholelithiasis and previous abdominal surgery in whom a chest X-ray revealed a right-sided heart, whereas abdominal ultrasound revealed that his gallbladder was located in the left hypochondrium. At surgery, the surgeon and the camera assistant were standing on the right-hand side of the patient, and the first assistant was standing on the left. The camera was introduced through an umbilical incision, and laparoscopy confirmed the situs inversus. The other 10-mm trocar was placed in the midline left of the falciform ligament and two 5-mm trocars were placed in the left subcostal midclavicular line and anterior axillary line, respectively. After dissection of multiple adhesions caused by previous abdominal surgery, a standard laparoscopic cholecystectomy was performed successfully. This report suggests that situs inversus is not a contraindication for laparoscopic surgery. However, the procedure is more difficult and potentially hazardous due to the mirror-image anatomy (particularly the transposition of biliary ducts) causing difficulties in orientation, so that extreme care is required to avoid iatrogenic injuries. Despite these factors, laparoscopic cholecystectomy can be performed safely in patients with situs inversus totalis.

Abdomen↗

PubMed2002

Spontaneous pneumothorax resulting from congenital cystic adenomatoid malformation in a pre-term infant: case report and literature review.

In the literature there are only three reported cases of spontaneous pneumothorax resulting from congenital cystic adenomatoid malformation in children under 1 year and for whom any resuscitative efforts were made. We present here a fourth case of a pre-term baby girl who was in perfect health, until she suffered a spontaneous pneumothorax as the initial manifestation of congenital cystic adenomatoid malformation of the lung at 10 weeks of age. Atypical segmentectomy with the use of stapling devices was successful. The characteristics of this particular manifestation are discussed.

Cystic Adenomatoid Malformation of Lung, Congenita↗

PubMed2002

Prognostic role of angiogenesis in operable carcinoma of the gallbladder.

The prognostic significance of intratumoral angiogenesis was investigated in 62 patients with stage I-III carcinomas of the gallbladder treated with simple cholecystectomy. Microvessel density (MVD) was assessed immunohistochemically, using the alkaline phosphatase/anti-alkaline phosphatase method and the monoclonal antibody CD31. The mean MVD was 30.5 vessels per x 200 optical field. Using the thirty-third and the sixty-sixth percentile, the patients were grouped into three MVD categories: low (MVD 9-18; 20 patients), medium (MVD 19-31; 20 patients), and high (MVD 32-86; 22 patients). A high MVD was more frequent in well-differentiated adenocarcinomas compared with moderately and poorly differentiated tumors (p = 0.04), but there was no statistically significant association between MVD and T stage, or patients' age or sex. Multivariate analysis, including MVD, T stage, and histologic grade, showed that MVD was a significant independent prognostic factor in carcinomas of the gallbladder (p = 0.001, t ratio 3.3). It is believed that the assessment of intratumoral angiogenesis in patients with operable gallbladder carcinomas may be useful in predicting prognosis and, perhaps, in decision making for postoperative adjuvant treatment.

Adult↗