PubMed Health⌕ Search

Biomedical subjects

J Papadimitriou

Publications and source records attributed to J Papadimitriou.

At least 55 records · Page 3Linked to original sources
PubMed1994

Experimental transplantation of hepatocytes in cases of toxic acute liver failure. An allograft model.

The aim of this experimental study was to modify a rat liver-cell harvesting technique and to evaluate the efficacy of allogeneic liver cell transplantation (Tx) using cyclosporin A immunosuppression in rats with N-dimethylonitrosamine (N-DMNA)-induced acute liver failure (ALF). Twenty male Wistar rats, weighing 190-320 g, were used as donors. Hepatocytes were harvested by the use of a modification of the Seglen portal vein collagenase perfusion technique (type V/1.3 mg/ml), which resulted in the isolation of a mean of 8000 viable clusters of hepatocytes per donor (viability was measured using the trypan blue exclusion test). The male Lewis recipients and controls received 20 mg/kg N-DMNA i.v., and were then divided in three groups. Group 1 (n = 5) received no treatment, group 2 (n = 10) received 5000 clusters of freshly isolated hepatocytes (FIH) in the spleen 24 h after the administration of N-DMNA- and group 3 (n = 10) received 5000 clusters of FIH beneath the renal capsule, 24 h after the administration of N-DMNA. All groups were treated with cyclosporin A 20 mg/kg per day i.p.. SGOT and bilirubin values were measured and all surviving rats were sacrificed on day 14. All rats in group 1 died of histologically confirmed liver necrosis within 72 h. The 14-day survival was 60% in group 2 and 50% in group 3. The post-Tx SGOT values reached their maximum on days 3-4 (group 2, mean 754; group 3, mean 529) and were only slightly elevated on day 14 (group 2 = 75, group 3 = 48). The post-Tx bilirubin values reached their maximum on days 3-5 (group 2 = 1.1, group 3 = 1) but failed to return to normal until day 14. Autopsy and histological examination of the surviving animals showed well-preserved hepatocellular spherical aggregates in the spleen and hepatocellular "cords" in the kidney accompanied by signs of regeneration of the native liver. We concluded that the hepatocyte Tx in a rat experimental allo-Tx model improved the survival rate and the SGOT values in cases of toxic ALF. Survival rates between the two different sites of Tx were similar.

Animals↗
PubMed1994

Combined hepatocyte-islet transplantation: an allograft model.

Experimental hepatocyte transplantation (Tx) has been shown to improve the survival rate of acute hepatic failure (AHF) in different models. Histological and biochemical data from some studies suggest more satisfactory function of hepatocytes after combined hepatocyte-islet Tx. The aim of the present study was to compare the survival rate between two different sites of Tx (kidney subcapsular and spleen) of hepatocytes alone or combined with islets of Langerhans in rats with surgically induced AHF (90% hepatectomy) accross a major histocompatibility barrier (WAG to Lewis). Rats were divided into five groups (n = 6 in each group). Group 1 consisted of AHF without treatment, group 2, AHF followed by hepatocyte Tx into the spleen, group 3, AHF followed by hepatocyte Tx subcapsular into the kidney, group 4, AHF followed by combined hepatocyte islet Tx into the spleen, and group 5, AHF followed by combined hepatocyte islet Tx subcapsular into the kidney. The number of hepatocytes was 10(7) and the number of islets was 400. All rats received cyclosporin A (CsA) i.v. (20 mg/kg on days 0-4 and 10 mg/kg on days 5-30). Hepatocytes were harvested using a modification of the portal vein collagenase perfusion (type V 1.3 mg/ml) and islets, with the collagenase digestive technique (type XI 1 mg/ml). All Tx took place 24 h after AHF. All rats in group 1 died within 48 h. In groups 2 and 3, the combined survival rate was 33% 1 month after Tx, while in groups 4 and 5, the combined survival rate was 50% at 1 month. All surviving animals were sacrificed and histological examination showed well-preserved hepatocellular aggregates in the spleen and beneath the renal capsule, as well as islets around the clusters of hepatocytes. SGOT and SGPT values were also measured. We concluded that the combined Tx in a rat experimental allo-Tx model in cases of AHF improves the survival rate in comparison with hepatocyte Tx alone. The survival rate at the two different sites for combined Tx was similar.

Animals↗
PubMed1993

Role of early and extensive surgery in the treatment of severe necrotizing soft tissue infection.

Forty-two patients with necrotizing soft tissue infection are reviewed. Bacterial culture revealed between two and seven types of micro-organism in each patient. All patients were treated with radical surgical debridement and a combination of antibiotics. In 30 patients, early diagnosis and treatment resulted in only two deaths. Delayed surgical intervention in 12 patients transferred from outside hospitals was followed by nine deaths. Predisposing factors and site of infection did not affect outcome. Of 26 patients with systemic manifestations of sepsis, 16 survivors responded well to initial surgical debridement.

Connective Tissue Diseases↗
PubMed1993

Endoscopic drainage of acute obstructive cholecystitis in patients with increased operative risk.

Emergency biliary surgery for acute obstructive cholecystitis in the elderly is associated with an increased hospital mortality. We therefore attempted to drain the obstructed gallbladder via the transpapillary route in 18 patients (mean age: 67 years) who had cystic duct obstruction on ERC and who were at an increased surgical risk. A cholecystonasal catheter was successfully introduced after a small EPT in sixteen of them (89%). This resulted in effective bile drainage, obviating the need for emergency surgery in all patients. No procedure-associated morbidity or mortality was found. Following clinical remission, elective treatment consisted of ESWL/direct stone dissolution (n = 10) or elective surgery (n = 3). Three patients received no further therapy. Our results show that endoscopic gallbladder drainage may be a valuable alternative to emergency surgery in high risk patients with acute obstructive cholecystitis.

Acute Disease↗
PubMed1993

Immunohistochemical demonstration of nerve fibers in pelvic adhesions.

OBJECTIVE: To demonstrate the presence of nerve fibers in pelvic adhesions potentially capable of conducting pain stimuli. METHODS: Pelvic adhesions from 17 patients, ten of whom had a history of pelvic pain, were examined histologically. Routine hematoxylin and eosin stains and immunoperoxidase stains for S100 protein, B lymphocytes, and T lymphocytes were performed. Mesothelial proliferation, presence of calcification and/or psammoma bodies, edema, vascularization, inflammation, fibroblastic proliferation, and collagenization were graded from 0 (absent) to 3 (extensive); their prevalences were compared between patients with and without pelvic pain. RESULTS: Nerve fibers were present in specimens from ten of the 17 patients (five of ten patients with and five of seven without pain). There was no statistically significant difference in the numbers with nerve fibers or in the presence of mesothelial proliferation, calcification and/or psammoma bodies, edema, vascularization, inflammation, fibroblastic proliferation, or collagenization between the groups. In all cases, the infiltrating lymphocytes were T lymphocytes. CONCLUSION: We were able to demonstrate the presence of nerve fibers in pelvic adhesions; however, their presence was not more prevalent among patients with pelvic pain. These findings support the concept that the formation of adhesions has different stages, with the final formation of mature connective tissue with its own vascularization and innervation.

Cell Division↗
PubMed1992

Two malignant peripheral primitive neuroepithelial tumor cell lines established from consecutive samples of one patient: characterization and cytogenetic analysis.

A 6-year-old girl presented with a tumor of the right shoulder involving bone, adjacent soft tissue, and regional lymph nodes. The conventional histologic diagnosis was ambiguous, initially suggesting lymphoma. After relapse on lymphoma therapy, reevaluation with additional multiple diagnostic techniques performed on the biopsy tissue and on two cell lines derived from the biopsies established the diagnosis of a primitive neuroepithelial tumor of bone and soft tissue. This was strongly supported by 1) focal rosette formation by the tumor cells and positive immunostaining for neuron-specific enolase and synaptophysin, with absent staining for leukocyte common antigen; 2) at the ultrastructural level, formation of cellular processes containing microtubules, a paucity of neurosecretory granules, absence of synaptic junctions, formation of long "intermediate" junctions between cells, and, in culture, widespread development of rosettes; 3) marked surface positivity to W 6/32 and negativity to HSAN 1.2 antibodies; and 4) elevated expression of MYC and lack of overexpression of MYCN oncogenes. Numerical and structural abnormalities were present in the karyotype, but the expected t(11;22)(q24;q12) was not present in the tumor-involved marrow or in either of the established tumor cell lines, although there was an interstitial deletion of 11q involving breakpoints in q21 and q23.

Biomarkers, Tumor↗
PubMed1990

The autogenic ligament procedure: a technique for planned formation of an artificial neo-ligament.

A new surgical principle which can safely result in the formation of an artificial neo-ligament, and induce the adhesion of tissues is described. Under certain conditions, an implanted Mersilene tape may act as a template, provoking a controlled linear deposition of collagen which remained unchanged, even after removal of the tape. This was proven by retropubic implantation of Mersilene tapes in female dogs, in the position of the pubo-urethral ligament. The procedure relies on the normally negative aspects of wound healing for its effect, such as foreign body reaction, bacterial colonization, and continued tissue breakdown and regeneration.

Animals↗
PubMed1987

Nuclear DNA content and prognosis in human breast cancer: a static cytophotometric study.

Nuclear DNA content was measured by static cytophotometry in smears from breast carcinomas from 80 women, and the results were correlated with other prognostic variables and survival using multivariate statistical analysis. 49% of patients had diploid tumors and 51% hyperdiploid tumors. There was a strong correlation between DNA ploidy and axillary lymph node status, tumor size, ER status, and short term survival (median follow-up 40 months). Of all parameters measured, ploidy showed the strongest correlation with survival, and was a significant prognostic indicator even when other prognostic factors were taken into account.

Age Factors↗
PubMed1987

Pancreatic abscess due to infected hydatid disease.

A 35-year-old man sought treatment for acute epigastric pain, mild jaundice, and high fever. The patient was alcoholic and had been treated for a week in another hospital, at which time the clinical findings and indirect laboratory test indicated an attack of acute pancreatitis. At admission to the surgical intensive care unit of Aretaieon Hospital, the patient was in a septic condition; a computed tomographic scan of the upper abdomen revealed an abscess at the head of the pancreas. Surgical exploration showed an infected hydatid cyst at the head of the pancreas and pancreatic edema. The cyst was evacuated and drained, which resulted in formation of an external pancreatic fistula. Fistulography showed a communication of the residual cavity with the main pancreatic duct. The patient was begun on a regimen of somatostatin infusion, and the fistula closed within 3 days. The patient was discharged on the sixteenth postoperative day and has remained in good health for a year.

Abscess↗
PubMed1985

Mesothelial healing: morphological and kinetic investigations.

By using structural, kinetic and irradiation techniques it is possible to show that mesothelial healing is a local event. Initially, macrophages occupy the surface of a wound on the injured visceral layer, while mesothelial proliferation proceeds at the edge of the wound and the opposing parietal surface. Fibrin is formed on the wound surface within 24 h, even in the absence of much haemorrhage. Mesothelial ingrowth begins with isolated cells migrating from the wound edge as well as from the serosal surface apposing the wound where mesothelial cells are actively replicating. The cells presumably slide over a bridge of fibrin and macrophages, a process likely to be enhanced by the serosal fluid. Early colonization by macrophages results in the removal of debris and probably prevents the formation of adhesions during mesothelial restoration.

Animals↗
PubMed1985

Fractures of the coronoid process of the mandible. An analysis of 52 cases.

Fractures of the coronoid process occur infrequently. In the present study, 52 cases of fracture of the coronoid process are presented and analysed and the relevant literature is reviewed. Coronoid fractures constituted 2.9% of all facial fractures. Of the 52 cases, 12 were isolated coronoid fractures (23%), whereas in the remaining 40 cases, coronoid fractures coexisted with other maxillofacial injuries. The clinical picture, diagnosis and therapeutic modalities of coronoid fractures are discussed.

Adolescent↗