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Biomedical subjects

A Kostakis

Publications and source records attributed to A Kostakis.

At least 55 records · Page 3Linked to original sources
PubMed1998

Hyperselective renal artery embolisation in the treatment of post-traumatic iatrogenic haematuria: report of two cases.

Angiography and selective renal artery embolisation were performed in two patients with post-traumatic iatrogenic kidney lesions and intractable haematuria. One patient presented after a nephrolithotomy with rupture of a segmental branch of the renal artery well demonstrated on selective angiography which showed intraparenchymal extravasion of contrast medium. The other presented after a renal biopsy with severe haematuria. Angiography performed 10 days later demonstrated an arteriovenous fistula at the site of the puncture. Hyperselective embolisation achieved immediate control of the haematuria in both patients, with maximal preservation of the renal parenchyma and maintenance of good renal function. At follow-up 12 months later, there had been no recurrence of the haematuria. These results suggest that transcatheter embolisation should be considered the method of first choice in renal trauma accompanied by intractable haematuria before any surgery is attempted.

Arteriovenous Fistula↗
PubMed1997

Lower urinary tract reconstruction in association with renal transplantation.

Congenital or acquired dysfunction of the lower urinary tract may result in renal failure. In this group of patients urinary diversion or lower urinary tract reconstruction is mandatory prior to renal transplantation. Avoiding creation of an external stoma offers far more better quality of life to these unfortunate patients. We present three patients in end-stage renal disease. Two of them presented with dysfunction of the lower urinary tract and the third with absence of the bladder. Reconstruction or substitution of their bladders has been performed prior to kidney transplantation. In one patient an artificial urinary sphincter was implanted simultaneously in order to achieve continence, while all the patients have to empty their neobladders or augmented bladders by clean intermittent self-catheterization. In conclusion, dysfunction or absence of the lower urinary tract does not preclude renal transplantation and however abnormal the urinary tract, transplantation can still be performed if low-pressure, high-compliance reservoir can be achieved by means of augmentation or substitution cystoplasty.

Adult↗
PubMed1997

The 10 years single center experience of using elderly donors for living related kidney transplantation.

The use of elderly donors has been advocated to expand the organ donor pool because of increased needs and organ shortage. The aim of the study was to analyse whether old age of donors affects the outcome of renal transplantation and the long term safety of retrieval for the donors. We present data of 335 consecutive living related kidney transplants, performed in our centre the last 10 years, where in 174 patients the donor was less than 60 years of age, while in the rest 161 patients the donor was more than 60 years of age. No statistical difference was noted in either group at the incidence of irreversible acute rejections, early acute tubular necrosis, vascular complications and patient deaths. The graft survival was 86.7%, 80.4% and 78.1% for the 3rd, the 5th and the 8th year for the younger group of donors, while it was 83.6%, 78.2% and 67.8% for the older group (p = 0.13). Patient survival of the younger group was 95.9%, 94.7% and 94.7%, while for the older was 94.4%, 92.0% and 89.2% for the 3rd, the 5th, and the 8th year post transplantation (p = 0.24). Functional rehabilitation and quality of life were good in donors and recipients of both groups. These results suggest that renal transplantation from elderly donors offers comparable results from those obtained from younger donors.

Adolescent↗
PubMed1997

The outcome of 2.3 mm incision combined phacoemulsification, trabeculectomy and lens implantation of non-foldable intraocular lenses.

We report the results of 100 eyes in 88 patients that underwent combined phacoemulsification and implantation of non-foldable intraocular lenses (IOLs) following enlargement of the initial 2.3 mm opening and trabeculectomy. Intraocular pressure (IOP) control (< 21 mmHg) was attained in 96% of the eyes. Visual acuity of 6/12 or better was attained in 76% of the eyes. A filtering bleb was absent in only 11% of the eyes. All these outcomes were favourable compared with previously reported series in which foldable IOLs were inserted without enlargement of the initial trabeculectomy openings. We conclude that the combination of small-incision cataract surgery and trabeculectomy with implantation of non-foldable IOLs is a successful surgical approach for visual rehabilitation and glaucoma control in patients with concurrent cataract and glaucoma.

Cataract↗
PubMed1996

Cell senescence and a mechanism of clonal evolution leading to continuous cell proliferation, loss of heterozygosity, and tumor heterogeneity: studies on two immortal colon cancer cell lines.

Extensive karyotypic analysis was performed on early and late passages of two continuous human cell lines, SW480 and SW620, that were derived from the same colon cancer patient. We cultivated these two cell lines in vitro for a period of 24 months and periodically examined their chromosome constitution. SW480 cells, from passage 138, were injected subcutaneously into 20 nude mice. The tumors that grew in nude mice were then cultivated in vitro for several passages to compare histopathologic findings and tumor growth patterns with clonal chromosomal profiles. Despite some karyotypic diversity, the two cell lines exhibited common marker chromosomes and followed similar patterns of evolution. During subsequent passages, acquisition of new chromosomal abnormalities gave rise to sidelines with a near-diploid genome that frequently underwent endoreduplication. Genomic instability seemed to play an important role in the emergence, growth, and subsequent elimination of the heterogenous sidelines by selection, clonal expansion, and cell death by senescence. Despite continuous growth, both the cell lines occasionally showed telomeric associations and random dicentric and multicentric formations. These lesions were considered evidence of cell senescence and were related to the disappearance of particular sidelines through evolution. Successful evolutionary steps were characterized by elimination of pre-existing marker chromosomes that were subsequently replaced in the karyotype by their cytologically intact homologous chromosomes possibly after selective endoreduplication. Frequent loss of heterozygosity for the chromosomes taking part in this process is postulated. We suggest that one of the mechanisms by which cancer cells bypass senescence may be related to their potential for continuous clonal diversification.

Animals↗
PubMed1996

Expression of bcl-2 oncoprotein in various types of glomerulonephritis and renal allografts.

BACKGROUND: Bcl-2 oncogene was identified as a transcript associated with the t (14;18) and exhibits the unique functional role of blocking apoptosis. Apoptosis as a remodelling mechanism has been reported to embryonic and adult kidney. The aim of this study was to investigate the expression of bcl-2 protein in normal and diseased renal tissue and to define any correlation with the type of renal injury. MATERIALS AND METHODS: Our material comprised of 10 normal adult kidneys, 31 renal allografts with acute (22) and chronic (9) rejection, and 70 renal biopsies with various types of primary (49) (31 proliferative and 18 non-proliferative) and secondary (21) glomerulonephritis. The immunohistochemical strept.ABC method was performed on paraffin sections for the detection of bcl-2 protein with a monoclonal antibody after microwave pretreatment. RESULTS: Bcl-2 protein was detected in all the cases of normal and diseased renal tissue, showing an analogous expression. The antigen was expressed in a few parietal epithelial cells, and in the majority of distal and collecting tubular epithelial cells, but not in the glomerular capillary tuft. No difference was found in bcl-2 expression between cases of proliferative and non-proliferative glomerulonephritis as a whole, or between primary and secondary glomerulonephritis. Bcl-2 expression in acute and chronic rejection demonstrated a similar cytoarchitectural expression to the one observed in normal kidneys and glomerulonephritis. Bcl-2 was detected in podocytes near intraglomerular fibrotic lesions and in epithelial cells of early adhesions and cellular crescents, wherever observed in cases of glomerulonephritis. However, bcl-2 expression in proximal tubular epithelial cells was significantly higher in cases of proliferative glomerulonephritis than in non-proliferative glomerulonephritis (P<0.01), while bcl-2 expression in parietal epithelial cells in cases of chronic rejection was higher than in cases of acute rejection (P<0.08). CONCLUSIONS: The absence of bcl-2 expression in normal and diseased glomeruli suggests and supports the reported notion that the mechanism of apoptosis may be available in the injured glomerulus. Moreover, bcl-2 expression in podocytes near intraglomerular fibrotic lesions and in epithelial cells of early adhesions and cellular crescents indicates the deregulation of apoptosis and its possible role in the progression of glomerular scarring. Key words: apoptosis; bcl-2 oncoprotein; glomerulonephritis; immunohistochemical; renal rejection.

Adult↗
PubMed1994

Hamartoma of Brunner's glands causing massive haematemesis.

BACKGROUND: Brunner's gland hamartomas are very uncommon lesions and are usually asymptomatic. METHODS: A 77-year-old man was urgently operated on for massive upper gastrointestinal bleeding, associated with haematemesis. RESULTS: A 3.5 x 3 x 3 cm mass arising from the anterior aspect of the first part of the duodenum was found. Histologic examination showed groups of Brunner-type glands without atypia; these coexisted with heterotopic pancreatic acini and ducts. CONCLUSIONS: This is a very rare cause of massive upper gastrointestinal bleeding and may easily be confused with bleeding from a peptic ulcer.

Aged↗
PubMed1994

Immunohistochemical study of epidermal growth factor receptor (EGFR) in various types of renal injury.

Epidermal growth factor (EGF), a polypeptide with a potent mitogen activity, and its receptor [EGFR] have been previously identified in the kidney, but their expression in normal and diseased kidneys has not been fully elucidated. In order to evaluate EGFR in various histological types of renal injury, EGFR expression was studied by the immunohistochemical avidin-biotin complex (ABC) method with a monoclonal antibody EGFR1 on paraffin sections from 10 normal kidneys, 56 renal biopsies with various types of glomerulonephritis (GN), and 20 renal grafts with rejection. EGFR expression was observed in (a) 3 of 10 (30%) normal kidneys, (b) 17 of 39 (43.6%) renal biopsies with various types of GN mainly in membranous GN (57%) and in focal segmental glomerulosclerosis (FSG) (62.5%), (c) 6 of 17 (35.3%) biopsies with various types of systemic lupus erythematosus GN, and (d) 12 of 20 (60%) renal grafts with acute (42.9%) and chronic (69.2%) rejection. EGFR was mainly localized to the epithelial cells of the distal and collecting tubules and extraglomelar vessels, while it was observed less frequently in parietal epithelial cells and along glomerular basement membranes. Notably EGFR was detected in the epithelial cells adjacent to adhesions with Bowman's capsule and in the connective tissue of fibrocellular crescents. In conclusion, EGFR expression was observed more frequently in diseased than in normal kidneys. The increased incidence of EGFR expression in FSG, in chronic rejection, in small adhesions with Bowman's capsule and fibrocellular crescents suggest that EGF/EGFR may be correlated with a disturbed extracellular matrix production resulting in formation of early sclerotic lesions.

Basement Membrane↗
PubMed1993

Hepatitis C virus infection among Greek renal transplant patients.

In this study, the prevalence of hepatitis C virus (HCV) infection among renal transplant recipients was high, directly proportional to the haemodialysis time before transplant and inversely proportional to the time after this. There was evidence of previous infection with hepatitis B virus (HBV), and a high prevalence of abnormal liver function tests. Virus induced chronic hepatitis lesions were rare, probably as a result of immunosuppression.

Female↗
PubMed1992

Antibodies against hepatitis C virus among renal transplant patients in Greece.

To evaluate the prevalence of hepatitis C virus (HCV) infection in Greek renal transplant (RT) patients and its association with abnormal liver function tests (LFTs), serum anti-HCV was determined (Ortho-ELISA test system) in 206 RT and 245 haemodialysis patients (HD) as controls. The prevalence (10.2%) of anti-HCV in RT patients was significantly higher (P < 0.0001) than in the Greek general population (0.7%) and lower (P < 0.0001) than in the HD patients (23.8%), and was not related to the patients' age, post-transplant time or pre-transplant HD time. None of the anti-HCV RT patients was HBsAg+, whereas 13 (62%) and 12 (57%) of them were anti-HBsAg+ and anti-HBc+, respectively. The incidence of abnormal LFTs in anti-HCV+ HBsAg- and anti-HCV- HBsAg+ RT patients was similar. Our findings indicate that: (a) the prevalence of serum anti-HCV in the Greek RT population is high, although considerably lower than in HD pts; (b) anti-HCV+ RT patients have a high incidence of abnormal LFTs, comparable to that seen in HBsAg+ RT patients; and (c) in a substantial proportion of anti-HCV+ RT patients there is evidence of previous HBV infection.

Adolescent↗
PubMed1991

Tumor markers in patients undergoing hemodialysis or kidney transplantation.

The following tumor markers, AFP, CEA, CA 19-9, CA-125 and CA 15-3 were studied in 50 healthy volunteers (group A), in 23 patients on chronic hemodialysis (group B) and in 30 successfully transplanted individuals (group C) who did not present any clinical symptoms or signs of neoplasia. The levels of AFP, CEA and CA 15-3 were significantly higher in group B when compared to groups A and C. The levels of CA 19-9 and CA-125 did not differ significantly among the three groups. Transplanted individuals (group C) presented significantly lower levels of CEA and AFP and higher levels of CA 15-3 when compared to group B patients. The levels of all markers were not influenced by sex or time on dialysis. It is concluded that: (1) CA 19-9 and CA-125 can be considered as reliable tumor markers in patients undergoing hemodialysis or kidney transplantation. (2) The elevation of CEA and AFP levels in hemodialysis and their decline to normal levels found in the group of successfully transplanted individuals, suggest a possible active role of functioning renal tissue in their clearance. (3) The etiology of CA 15.3 elevation following successful kidney transplantation remains obscure and requires further evaluation.

Adult↗
PubMed1985

Pentoxifylline in the treatment of experimental peritonitis in rats.

The objective of this study was to determine the effect of pentoxifylline on the clinical and pathologic course of experimentally induced peritonitis in rats. This drug is a methyxanthine derivative that has vasodilating properties and may decrease platelet aggregation. Peritonitis was induced in 40 Wistar rats by creating a closed ileal loop 4 cm long 5 cm from the ileocecal valve. The animals were divided into two groups of 20 animals each. The first group served as controls, while each animal of the second group received 17 mg/kg/day of pentoxifylline intramuscularly from the day of operation until 30 days postoperatively. The survival rate was significantly increased in the group receiving pentoxifylline and adhesion or abscess formation was considerably reduced. We concluded that the administration of pentoxifylline prolongs significantly the survival of animals with experimental peritonitis and reduces the development of adhesions and abscesses in the peritoneal cavity. This beneficial effect may be attributed to decreased fibrinogen deposits and increased fibrinolytic activity within the peritoneal cavity, thus rendering the bacteria more susceptible to cellular and noncellular clearing mechanisms.

Abscess↗
PubMed1985

Effect of aprotinin on fibrinopurulent peritonitis in rats.

The effect of aprotinin on the clinical and pathologic course of experimentally induced peritonitis in the rat was studied. Peritonitis was induced in 40 rats by creating a closed ileal loop 4 cm long 5 cm from the ileocecal valve. The rats were divided into two groups of 20 rats each. Group 1 served as a control group, whereas each animal in Group 2 received a bolus dose of aprotinin (10 ml) intraperitoneally immediately after closing the laparotomy. In the aprotinin-treated group, survival was drastically increased (p less than 0.01) and formation of adhesions and abscesses was considerably reduced. The results of peritoneal cultures showed a decreased incidence of Escherichia coli and Clostridia in the aprotinin-treated group. We conclude that the administration of aprotinin significantly prolongs the survival time of animals with peritonitis and reduces the development of adhesions and abscesses in the peritoneal cavity. This beneficial effect can be attributed to decreased fibrinogen deposits within the peritoneal cavity and the stabilization of the organism after bacterial shock. Thus, bacteria were more susceptible to cellular and noncellular clearing mechanisms.

Abscess↗