PubMed Health⌕ Search

Biomedical subjects

G Karatzas

Publications and source records attributed to G Karatzas.

At least 37 records · Page 2Linked to original sources
PubMed1998

Level of alpha-catenin expression in colorectal cancer correlates with invasiveness, metastatic potential, and survival.

BACKGROUND AND OBJECTIVES: Decreased expression of the E-cadherin/alpha-catenin cell-cell adhesion complex is considered to elicit detachment of tumor cells from primary lesions and development of metastases. The immunohistochemical profile of alpha-catenin in colorectal cancer, as well as its correlation with differentiation, lymph node/liver metastasis and patient survival is presented in this study. METHODS: Alpha-Catenin expression was investigated with immunohistochemistry technique, in 85 paraffin-embedded and 21 fresh frozen specimens, including 82 colon adenocarcinomas, 10 adenomas, 10 lymph nodes, and 3 liver metastases. Preserved alpha-catenin expression was considered for those tumors that demonstrated more than 90% alpha-catenin(+) cancer cells and reduced alpha-catenin expression for those tumors with less than 90% alpha-catenin(+) cancer cells. The chi2-test was used to calculate the statistical correlation of alpha-catenin expression with grade of differentiation and metastatic potential and the log-rank test for the correlation with survival rate. RESULTS: Normal mucosa, as well as 8/10 of the colon adenomas, showed strong membranous alpha-catenin expression. Reduced alpha-catenin expression was found in 32/82 (39%) colorectal cancers examined, which was associated with de-differentiation (P < 0.01), lymph node metastasis (P < 0.025), and poor clinical outcome (P < 0.012). Alpha-Catenin expression was preserved in 3 liver metastases and their corresponding primary tumors. By contrast, 6/10 of lymphogenous metastases showed decreased alpha-catenin expression. CONCLUSIONS: Our findings demonstrate a significant down-regulation of alpha-catenin expression in colorectal cancer which is associated with poor differentiation, higher metastatic potential and unfavorable prognosis. These preliminary results suggest that alpha-catenin may be a useful marker of invasiveness, metastatic potential, and survival in colorectal cancer patients.

Adenocarcinoma↗
PubMed1998

Massive intraperitoneal hemorrhage caused by a giant exogastric leiomyoblastoma.

Leiomyoblastomas account for a small percentage of smooth muscle tumors of the stomach. Intraperitoneal bleeding is an unusual and unexpected presenting sign. We herein present a 43-year-old woman who was urgently operated on due to signs of collapse. A large hemorrhagic mass measuring 25 x 18 x 15 cm was found arising from the greater curvature of the stomach. A histologic examination demonstrated rounded and spindle cells, and rare mitoses were also seen. Although the number of mitoses was small, the lesion was nevertheless felt to be consistent with malignant leiomyoblastoma because of its large size. Three years later the patient is doing well with no evidence of tumor recurrence. We conclude that intraperitoneal bleeding due to leiomyoblastoma of the gastrointestinal tract is an extremely rare phenomenon and has been described only in a few reports, and only one other previous case presented with signs of collapse.

Adult↗
PubMed1998

Combined epirubicin, 5-fluorouracil and folinic acid vs no treatment for patients with advanced pancreatic cancer: a prospective comparative study.

The combination of 5-fluorouracil (5-FU) and folinic acid (FA) has demonstrated activity in most gastrointestinal tumors. The addition of epirubicin (EPI) may increase the efficacy of the combination for cancers of the upper gastrointestinal tract, such as advanced pancreatic cancer. We examined two groups of patients, explaining the potential benefits and limitations of therapy, and those patients who agreed to undergo chemotherapy formed Group A and the remaining formed Group B. Therefore, the study was a non-randomized prospective comparison between patients receiving chemotherapy and those offered the best supportive care. Group A consisted of 42 patients; 19 underwent Roux-en-Y operation, and 23 were inoperable. Group B consisted of 48 patients who refused chemotherapy; 18 underwent Roux-en-Y operation, and 30 were considered inoperable. Chemotherapy consisted of FA 200 mg/m2/day, 5-FU 600 mg/m2/day both for 5 days, and EPI 35 mg/m2/day before FA-5-FU administration on days 1 and 2, every 28 days. All patients were evaluable for response and toxicity. Objective tumor responses (partial responses) in Group A were seen in 8 patients (19%) (6 women and 2 men), and 6 (14%) had stable disease. The estimated median survival was 27.6 weeks (mean 27.5) for Group A and 22.5 weeks (mean 24) (p=0.01) for Group B. From the onset of therapy, median duration of response was 16.6 weeks and median time to progression 11.8 weeks in Group A. Toxicity consisted primarily of myelosuppression, nausea and vomiting, diarrhea, alopecia, and mucositis. In Group A 12/42 patients became free from pain for a median duration of 10 months, 14/42 had improved appetite, and 15/42 had improved performance status in comparison to Group B, where no patients had improved performance status or symptoms. We conclude that the combination of EPI+FA+5-FU has moderate activity and increased toxicity in the treatment of advanced pancreatic cancer.

Adult↗
PubMed1997

Fertility of fresh and frozen-thawed goat semen during the nonbreeding season.

A total of 4109 does of a local Greek breed (Capra prisca) were synchronized with intravaginal MPA-sponges and PMSG, and 24 bucks of Alpine (n = 8), Saanen (n = 8) and Damascus (n = 8) breeds were used for studying the fertility of nonfrozen and frozen-thawed semen during the nonbreeding season (June to August). Artificial insemination (AI) was performed once (50 to 55 h after sponge withdrawal) or twice (36 and 60 h after sponge withdrawals with fresh semen (collected during the nonbreeding season, stored at 16 degrees C and inseminated within 6 h) or frozen semen (prepared from the same bucks during the preceding breeding season). The induction of estrus was successful, varying between 91.0 and 95.0%. The form of semen (fresh or frozen-thawed used for inseminating the synchronized does affected their fertility: the overall kidding rate with fresh semen (65.5%) was higher (P < 0.05) than that with frozen-thawed semen (53.4%). The fertility level was also affected by the number of inseminations performed: the overall kidding rate was significantly higher (P < 0.001) in the does inseminated twice with fresh or frozen-thawed semen (70.4 and 59. 1%, respectively) than in those inseminated only once (48.9 and 44.9%, respectively). Finally, the breed of the buck used for preparing the fresh or the frozen-thawed semen affected the fertility level of the does. The kidding rate was higher in does inseminated with fresh semen prepared from bucks of the Damascus breed than from bucks of Saanen or Alpine breed. However, when frozen-thawed semen was used the kidding rate was lower in does inseminated with semen prepared from bucks of the Damascus breed than from bucks of the Alpine or Saanen breed. It is concluded that the fresh semen of Alpine, Saanen and Damascus breed bucks, born and raised under the climate conditions prevailing in Greece (34 degrees to 41 degrees N), can be used successfully during the nonbreeding season (June to August) for inseminating does.

Journal Article↗
PubMed1997

Systemic stress response after laparoscopic or open cholecystectomy: a randomized trial.

BACKGROUND: Surgical injury induces a systemic endocrine-metabolic response which is proportional to the severity of surgical stress. Laparoscopic cholecystectomy is associated with a favourable clinical outcome compared with open cholecystectomy suggesting that surgical injury is reduced. METHODS: In a randomized clinical trial of 41 patients undergoing laparoscopic cholecystectomy and 42 patients undergoing open cholecystectomy, the neuroendocrine and metabolic stress responses were compared. Plasma levels of cortisol, adrenaline, noradrenaline, glucose, interleukin (IL) 6 and C-reactive protein (CRP) were measured before, during and at 4, 8 and 24 h after operation. RESULTS: Plasma levels of cortisol and catecholamines increased during and after both laparoscopic and open cholecystectomy; however, their postoperative responses during and after both laparoscopic and open cholecystectomy; however, their postoperative responses were significantly higher (P < 0.05) after open cholecystectomy. Glucose, IL-6 and CRP levels also increased after operation and were significantly higher (P < 0.05) in the open cholecystectomy group. CONCLUSION: The neuroendocrine stress response and inflammatory response following laparoscopic cholecystectomy were significantly reduced compared with those after open cholecystectomy.

Blood Glucose↗
PubMed1997

Management of foreign bodies of the rectum: report of 21 cases.

This is a report of 21 patients treated for non-therapeutic introduction of rectal foreign bodies in our institution. Nine out of 18 patients had manual transanal extractions performed under general anaesthesia while eight patients required insertion of retractors and gynaecological forceps. In three patients the vacuum from the hollow objects was abolished by passing a catheter through the anus to a point above the object. One of the patients required colotomy for retrieval of a wooden object. In three patients free perforations were obvious clinically with peritoneal signs and free air on plain abdominal radiographs. Treatment was end-sigmoid colostomy and mucous fistula, oversewing of the perforation and peritoneal irrigation. There were no deaths and only one complication occurred, a rectovaginal fistula.

Adult↗
PubMed1996

Biochemical modulation of fluorouracil: comparison of methotrexate, folinic acid, and fluorouracil versus folinic acid and fluorouracil in advanced colorectal cancer: a randomized trial.

Recent advances in biochemical pharmacology have revealed the basis for the biological modulation of 5-fluorouracil (5-FU) by methotrexate (MTX) and folinic acid (FA). Sequential use of MTX given 24 h prior to 5-FU has resulted in enhanced cell kill in vitro and in vivo. In addition, administration of FA prior to 5-FU has led to potentiation of 5-FU action by stabilization of the ternary complex of thymidine synthase. In the present randomized study, two groups of patients with advanced colorectal cancer were treated as follows: 43 patients (pts) in group A received 5-FU + FA, whereas 45 pts in group B received 5-FU + FA + MTX. The dosage was as follows: group A received FA i.v. at 300 mg/m2 per day, prior to i.v. 5-FU at 500 mg/m2 per day on days 1-4; group B was given MTX i.v. at 130 mg/m2 per day on day 0, followed 24 h later by FA at 15 mg q6h x 6, and 5-FU + FA was started on day 1 and given at the same doses and schedule described for group A. Objective responses were achieved by 8/43 pts in group A (1 complete response and 7 partial responses) and by 18/45 pts in group B (3 complete and 15 partial responses), all occurring in the liver. There was no significant difference in the median time to progression (group A 6.1 months, group B 6.8 months) or the median survival (group A 9.2 months, group B 10.3 months). Toxicity was significantly greater in group B [grade 2-3 mucositis 20% versus only 2% in group A (P < 0.0001); grade 3 diarrhea in group B 15% versus 3% in group A (P < 0.001)]. According to our results, double biological modulation of 5-FU with MTX + FA led to an enhanced response rate with increased toxicity as compared with the 5-FU + FA regimen given at less than its maximally tolerated dose.

Adenocarcinoma↗
PubMed1996

Postoperative pulmonary function after laparoscopic and open cholecystectomy.

In this prospective, randomized study, we compared 42 patients undergoing laparoscopic cholecystectomy and 40 undergoing open cholecystectomy to determine if laparoscopic cholecystectomy results in less respiratory impairment and fewer respiratory complications. Pulmonary function tests, arterial blood-gas analysis and chest radiographs were obtained in both groups before operation and on the second day after operation. Postoperative pain scores and analgesic requirements were also recorded. After operation, a significant reduction in total lung capacity, functional residual capacity (FRC), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and mid-expiratory flow (FEF25-75%) occurred after both laparoscopic and open cholecystectomy. The reductions in FRC, FEV1, FVC and FEF25-75% were smaller after laparoscopic (7%, 22%, 19% and 23%, respectively) than after open (21%, 38%, 32% and 34%, respectively) cholecystectomy. Laparoscopic cholecystectomy was also associated with a significantly lower incidence (28.6% vs 62.5%) and less severe atelectasis, better oxygenation and reduced postoperative pain and analgesia use compared with open cholecystectomy. We conclude that postoperative pulmonary function was impaired less after laparoscopic than after open cholecystectomy.

Adult↗
PubMed1996

Cystic dilatations of the common bile duct in adults.

Cystic dilatations of the common bile duct are believed to be of congenital etiology with most cases presenting in childhood. During the last 20 years, 10 patients with cystic dilatations of the bile duct were treated in our Department. There were 5 men and 5 women with an age range of 35-81 years. Clinical presentation consisted of right hypohondrial pain, nausea, vomiting and a history of obstructive jaundice. Diagnosis was established by ultrasound, cholangiography and ERCP in most cases. According to the Todani classification system, 5 patients had type I cysts, 4 had type II and one had type III. At the time of surgery, main associated diseases were choledocholithiasis in 3 cases and cholangitis in 2 cases. One patient (type III) underwent endoscopic sphincterotomy; 4 patients underwent internal drainage and 2 of them developed mild cholangitis postoperatively; 5 patients underwent excision of the cyst and a biliary-enteric bypass and developed no main complications. Patients remained in good health during long-term follow-up. We conclude that cyst excision is the treatment of choice for adults in order to reduce postoperative morbidity and the potential risk of malignancy.

Adult↗
PubMed1995

Therapeutic strategies for pancreatic pseudocysts.

During the last 15 years, a total of 26 patients were treated for pancreatic pseudocysts, at the 2nd Department of Propaedeutic Surgery, University of Athens. There were 16 (61.5%) men and 10 (38.5%) women aged between 19 and 82 years old (mean age 61 years). Dominating symptoms in most patients were epigastric mass and pain, nausea, vomiting, mild fever and leucocytosis, and persistent elevation of serum amylase. Imaging studies, such as ultrasound, CT scan, and ERCP, were mostly helpful in establishing diagnosis. In most cases, attack of acute pancreatitis preceded with the exception of two cases where there was chronic pancreatitis and another which was post-traumatic. Rapid progression of underlying pancreatitis led to urgent laparotomy in two patients (7.7%). Elective surgery was performed in 22 patients (84.6%), 1-7 months after onset of pancreatitis (median 2 months). Selection of operative procedure depended on the patient and cyst condition. Cystogastrostomy was performed in 18 patients (69.2%), cystojejunostomy in three patients (11.5%), and external drainage in three patients (11.5%). There were three postoperative deaths (11.5%). Haemorrhage and infection were the main complications. Percutaneous drainage was performed in two cases (7.7%) (one for a cyst remnant after an operative procedure), and medical treatment with somatostatin in another case (3.8%) with excellent clinical results. In conclusion, conservative treatment of pancreatic pseudocysts has good clinical results, but it is not always indicated. Surgical drainage remains the preferred method of treatment.

Adult↗
PubMed1980

Percutaneous arterial embolization in the kidneys of dogs: a comparative study of eight different materials.

Forty-one dogs were subjected to percutaneous arterial embolization of branches of the renal artery or its main trunk with or without prior injury to the kidney, with eight different materials, i.e., homologous blood clot, muscle, fat, fascia, barium sulphate, plain catgut, gelfoam and polyvinyl alcohol (Ivalon). From the immediate observations made, as well as the haemodynamic, angiographic and histological studies over a period ranging from 24 h to several weeks, it was concluded that Ivalon was the best material for arterial embolization.

Animals↗
PubMed1978

A comparative study between direct testicular and pedal lymphography in dogs. (A preliminary report).

In 20 dogs, 12 bilateral and 8 unilateral pedal and direct testicular lymphographies were performed. Comparison between the two methods showed that pedal lymphography failed to visualize some of the regional lymph nodes of the testicle. Histological examinations of the excised testicles two months after the injection of the contrast material failed to show any significant abnormalities. The potential applications of direct testicular lymphography are discussed.

Animals↗
PubMed1976

Treatment of hypersplenism by embolus placement in the splenic artery.

In a patient with liver cirrhosis and severe hypersplenism resistent to corticosteroids splenectomy was attempted but proved impossible. Embolisation of the splenic artery with tiny fragments of absorbable gelatin sponge induced gradual restitution of haematological function to normal after 6 wk. Abdominal pain, paralytic ileus of short duration, transient pyrexia, and pleural effusion ensued but were well tolerated. The patient has remained well, 2 1/2 mo later. It is suggested that this simple method may prove rewarding and could safely be used, if necessary, more than once in patients for whom other treatments are unsuitable or have failed.

Angiography↗
PubMedDate not supplied

Expression of PDGF-A, TGFb and VCAM-1 during the developmental stages of experimental atherosclerosis.

PURPOSE: A considerable number of growth factors, cytokines, and adhesion molecules are implicated in the development of atherosclerotic lesions. These molecules interact in a complex network influencing the evolution of several processes, such as lipid metabolism, cellular proliferation and tissue repair. The aim of this study was to evaluate the expression of the growth factors PDGF-A, and TGFb, and the adhesion molecule VCAM-1 in the sequential steps of experimental atherogenesis. METHODS: Forty-two New Zealand white male rabbits were divided into 4 groups. The group A rabbits (n = 8) received normal diet and served as control animals. The remaining groups were fed with a diet enriched with 1% cholesterol and 6% corn oil. The rabbits of group B (n = 9) were sacrificed 1 month after the beginning of the study, of group C (n = 15) after 2 months and of group D (n = 10) after 3 months. In tissue sections of the aortic arch the antibodies of the prementioned factors were detected immunohistochemically. RESULTS: In group A only TGFb and PDGF-A were detectable. In lesions of the first month PDGF-A expression was high but declined towards the third month. VCAM-1 expression was getting more intense up to the second month and subsided thereafter. TGFb expression intensified towards the third month. Changes in the expression of these factors were statistically significant. CONCLUSION: PDGF-A, responsible for the uncontrollable growth of smooth muscle cells, and VCAM-1, regulating monocyte recruitment in the intima, acts mainly during the early stages of atherogenesis. TGFb, one of the main factors controlling the formation of connective tissue matrix, has a gradually increasing expression towards the third month contributing probably to the fibrous plaque formation.

Animals↗