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Biomedical subjects

X Giannakopoulos

Publications and source records attributed to X Giannakopoulos.

At least 19 recordsLinked to original sources
PubMed2005

Giant simple renal cyst complicated with hypertension.

Solitary renal cysts are a common and usually asymptomatic occurrence in older patients. They may be associated with hypertension or abdominal disturbances, as they can be responsible for compression of surrounding tissues and distortion of renal vessels. This report presents an interesting case of a hypertensive patient with a solitary renal cyst of a marked size. Owing to the high risk of performing a surgical procedure in such a patient, a distinct therapeutic solution was opted for. Successful management of this case was achieved by a combination of percutaneous fluid aspiration and injection of alcohol and Vibramycin inside the cystic cavity. Percutaneous fluid evacuation combined with the administration of a sclerosing agent is suggested as a safe and effective alternative for cyst decompression and blood pressure normalisation.

Aged↗
PubMed2005

Solitary fibrous tumour of the epididymis: MRI features.

We present a case of a solitary fibrous tumour, located at the epididymis, in a 65-year-old man, presented with a scrotal mass. Ultrasound and MRI of the scrotum revealed a paratesticular mass, with rich vascularity, arising in the left epididymis. Radiological findings were non-specific and the patient underwent surgery.

Aged↗
PubMed2003

Micronuclei to detect in vivo chemotherapy damage in a p53 mutated solid tumour.

Apoptosis induction and micronuclei formation were compared following cytotoxic treatments in two rat glioma differing in p53 integrity. In vitro, micronuclei emergence but not apoptosis was linked to the p53 mutated status. In vivo, micronuclei assays were more sensitive to evaluate DNA damage induced by chemotherapy in a p53-mutated solid tumour.

Animals↗
PubMed2003

The role of ultrasonographically guided puncture of the human rete testis in the therapeutic management of nonobstructive azoospermia.

We attempted to characterize the cells collected from the rete testis via ultrasonographically guided puncture. Unilateral puncture of the rete testis was performed in nine men with obstructive azoospermia and 51 men with nonobstructive azoospermia. All the aspirated samples from the rete testis were observed via confocal scanning laser microscope and some of them after fluorescent in situ hybridization techniques. Then therapeutic testicular biopsy was performed in the punctured testis of each man. Spermatozoa were found in all rete testis samples and all biopsy samples from obstructed men. Twenty-two nonobstructed men demonstrated absence of spermatozoa in biopsy samples. Twenty-nine nonobstructed men showed spermatozoa in biopsy material and 24 of these men (82%) had demonstrated spermatozoa in rete testis samples. There were no significant differences in fertilization and cleavage rate between intracytoplasmic sperm injection trials using biopsy spermatozoa and rete testis spermatozoa both in obstructed and nonobstructed men. Considering that puncture of the rete testis does not reduce the volume of testicular parenchyma, is less invasive and apparently causes less detrimental effect on testicular vasculature than biopsy, puncture of rete testis is recommended as first line approach for the treatment of azoospermic men. If puncture is negative for spermatozoa in nonobstructed men, biopsy is indicated.

Biopsy↗
PubMed2003

Inhibition of benzo(a)pyrene-induced carcinogenesis by vitamin C alone and by vitamin C/vitamin E and selenium/glutathione.

The reduction on peroxidation caused by benzopyrenes by some naturally occurring antineoplastic agents was studied in this experimental work. Inhibition/reduction of experimental carcinogenesis induced by benzo(a)pyrene by vitamin C alone and by vitamin C/vitamin E and selenium/ glutathione was attempted in 224 female Wistar rats divided in four groups. Injected with 10.08 mL benzo(a)pyrene, the animals were treated with some naturally occurring substances like vitamin C alone and a combination of anticarcinogens. By calculating the carcinogenic potency of benzo(a)pyrene and the anticarcinogenic potency of substances used as well as histological examination of developed tumors and survival time of treated animals, it was found that vitamin C exerts a significant anticarcinogenic effect of 8.3 units and that the combination of the two anticarcinogens used produced a significant prolongation of the animals survival time with anticarcinogenic potency of 22.1 and 22.2 units, respectively. This is considered a potent anticarcinogenic effect. The question of an additional supportive administration of such agents complementary to the conventional cancer chemotherapy in humans is raised. Of course, further studies are needed.

Animals↗
PubMed2002

Cryptorchidism: seasonal variations in Greece do not support the theory of light.

To examine seasonal trends of cryptorchidism in Greece, 583 males with true isolated cryptorchidism were analyzed. All 208 912 live-born boys born during the same period were used as a comparison group. Seasonality by month of birth was evaluated using both Edwards' model with adjusted frequencies and exact theta(i), and Walter-Elwood method with exact theta(i). Both tests resulted in consistent findings. The incidence of cryptorchid births in Greece follows a documented cyclic pattern of simple harmonic type with spring being the season of statistical predominance (peak in March with a second, almost equivalent, peak in May). In contrast, in autumn the incidence of cryptorchid births was considerably lower (trough in September). Given the fact that no significant differences in daylight length are found among seasons in Greece, the detection of a significant seasonal variation suggests that factors other than light are involved in the pathogenesis of cryptorchidism. Low environmental temperature is proposed as a causative factor negatively influencing the maternal hCG profiles and the inguinoscrotal phase of testicular descent. This is further supported by: (i) the similarity of our results to those reported by other European countries of different longitude and geographical width and (ii) our data showing significantly smaller maternal hCG profiles at the 26th week of gestation during winter compared with summer.

Chorionic Gonadotropin↗
PubMed2001

Large infectious bladder stone after long delay in removing ureteral stent.

We herein present a case of formation of a large infectious bladder calculous resulted from placement of a double pigtail catheter for an extensive period. The concomitant poor function of the corresponding renal unit made selection of nephroureterectomy unavoidable in the management of our patient.

Device Removal↗
PubMed2001

Bladder cancer mortality in the Epirus district population (Greece).

OBJECTIVE: To describe the pattern of bladder cancer mortality in the Epirus district population (North-Western Greece) and to establish some relationships with cigarette smoking. PATIENTS AND METHODS: Mortality rates of bladder cancer in the Epirus district population were analysed according to the official data from the Department of Statistics of the University Hospital of Ioannina during the last decade (January 1990-January 2000). Age standardization of death rates was done by the direct method, using the world population as a standard. Fisher's test was used as a significance test for linear regression coefficient in time trend analysis of mortality. RESULTS: The average annual standardized mortality rates from bladder cancer during the study period were 5.23 per 100,000 population (96% Confidence Interval--Cl 4.02-5.63) in males and 1.63 per 100,000 population (96% Confidence Interval--CI 1.18-1.96) in females. Significantly increasing trends of the rates were observed in males (y = 2.421 + 0.231x; p < 0.01), but not in females (y = 1.263 + 0.027x: p > 0.05). The greatest increase in age - specific rates in males was observed in the age group of 70 and more years (y = 25.602 + 3.673x; p < 0.01). In females, all age--specific rates except for the group 60-69 years showed significantly increasing tendency. The increasing tendency of bladder cancer mortality is followed by the rise of per capita cigarette consumption among the Epirus district population. CONCLUSION: Further studies are needed for the explanation of the irregularities in the age-specific rates.

Adolescent↗
PubMed2000

Glutathione S-transferase null genotypes in transitional cell bladder cancer: a case-control study.

OBJECTIVES: This study was conducted (1) to examine whether the GSTM1 and GSTT1 null genotypes are risk factors for bladder cancer, and (2) to study a possible association of these genotypes with disease severity. METHODS: This case-control study was undertaken over a 21-month period and included 89 newly diagnosed transitional cell bladder cancer patients and 147 controls; both patients and controls originated from a defined population (residents of the loannina region, Northwestern Greece) and were similar with regard to mean age, male to female ratio and smoking habits. The GSTM1 and GSTT1 genotypes were identified by multiplex polymerase chain reaction on peripheral blood DNA samples. Genotype frequencies among patients and controls were assessed and the association of the genotypes with tumor grade and stage at presentation were statistically evaluated by the chi(2) test. RESULTS: The GSTM1 null genotype was strongly associated with bladder cancer. The odds ratio, attributable and population attributable risks were estimated at 2.76, 0.64 and 0.40, respectively. The correlation between the GSTM1 null genotype with stage, although not statistically significant, was estimated at an odds ratio of 2.6 for invasive disease. The correlation of GSTM1 null genotype with tumor grade did not yield a statistically significant result. The GSTT1 null genotype was not statistically associated with bladder cancer. CONCLUSION: According to our study, individuals with the GSTM1 null genotype carry a substantially higher risk for bladder carcinogenesis. The GSTM1 null genotype is not associated with more aggressive disease in terms of tumor grade, although there is a correlation between this genotype and stage of the disease.

Adult↗
PubMed1999

An experimental comparison of neural algorithms for independent component analysis and blind separation.

In this paper, we compare the performance of five prominent neural or adaptive algorithms designed for Independent Component Analysis (ICA) and blind source separation (BSS). In the first part of the study, we use artificial data for comparing the accuracy, convergence speed, computational load, and other relevant properties of the algorithms. In the second part, the algorithms are applied to three different real-world data sets. The task is either blind source separation or finding interesting directions in the data for visualisation purposes. We develop criteria for selecting the most meaningful basis vectors of ICA and measuring the quality of the results. The comparison reveals characteristic differences between the studied ICA algorithms. The most important conclusions of our comparison are robustness of the ICA algorithms with respect to modest modeling imperfections, and the superiority of fixed-point algorithms with respect to the computational load.

Algorithms↗
PubMed1999

Genotypes of N-acetyltransferase-2 and risk of bladder cancer: a case-control study.

PURPOSE: This study was conducted to examine whether certain slow N-acetylation genotypes could be risk factors for bladder cancer, and the possible association between specific genotypes and the severity of the disease at first diagnosis. MATERIALS AND METHODS: This case-control study included 89 patients with transitional cell bladder cancer (diagnosed over a period of 21 months) and 147 controls. N-acetyltransferase-2 (NAT-2) genotypes were identified by allele specific polymerase chain reaction (PCR) on peripheral blood DNA samples. The x2 test was used for statistical evaluation to compare the differences observed between patients and controls and the different genotypes with tumor grading and local staging at presentation. Relative, attributable and population attributable risks were estimated for the genotypes found to present a significantly increased frequency for bladder cancer. RESULTS: A statistically significant difference in the frequency of genotypes was found between the two groups. The patient group had the higher frequency of slow acetylation genotypes (p = 0.0016). Among slow acetylators, homozygotes 341C/341C and compound heterozygotes 341C/857A had the most excessive risk for bladder cancer (p = 0.0041 and 0.0031, respectively). The 341C/341C genotype was found to be associated with more aggressive disease, in terms of tumor grading at presentation (p <0.05). CONCLUSIONS: According to our data, slow acetylators with 341C/341C and 341C/857A genotypes carry a substantially higher odds ratio (3.73 and 12.46, respectively) for bladder carcinogenesis. Additionally, among the slow acetylators, 341C/341C homozygotes are likely to have a higher risk for more aggressive disease.

Adult↗
PubMed1997

Human bladder urine oxygen content: implications for urinary tract diseases.

Urine dissolved oxygen (DO) was measured in 40 healthy subjects and 115 patients divided into 4 groups according to their disease. Group 1 (20 patients) had lower urinary tract infection (UI), Group 2 (30 patients) had urinary stone disease (USD), Group 3 consisted of 50 end-stage chronic renal failure patients (CRF) and 15 patients in Group 4 were affected by influenza viral infection (IVI). Urinary and arterial PO2, PCO2 and pH were also measured in 20 healthy subjects. The other 20 healthy volunteers were subjected to submaximal exercise and afterwards urinary DO was estimated. Results revealed that in healthy subjects urinary DO or PO2 is not correlated with urinary pH or arterial pH, PO2 and PCO2. Also, urinary DO did not significantly vary on consecutive days. Urinary DO reflects mainly the renal metabolic state, being increased in conditions of decreased kidney metabolism such as CRF. Submaximal physical exercise, fever or urinary tract infection may significantly reduce urinary DO, whereas DO remains unaffected in uncomplicated USD. Human urinary DO is related to serum creatinine and urine volume. Our results indicate that urinary DO may be a useful indicator in clinical practice.

Adult↗
PubMed1997

Massive haemorrhage of inoperable bladder carcinomas: treatment by intravesical formalin solution.

Numerous modalities of treatment have been used in the past to control massive bladder haematuria, with varying degrees of success. Formalin has been used in urology only for the treatment of intractable haematuria of inoperable bladder carcinomas, usually as the last resort when all other nonsurgical attempts have failed and before more aggressive surgical measures are considered. Eight patients with bladder tumours classified T2 (2 cases), T3 (2 cases) or T4 (4 cases) and 2 patients with radiation cystitis were assessed as being beyond the scope of even palliative surgery, severe haemorrhage being present in all cases. The treatment was instituted in all cases by intravesical instillation of a 10 per cent formalin solution under general anaesthesia. Four patients received 4 and 6 instillations, respectively, the former over 4 weeks and the latter over 10 months. The bladder was filled completely and an indwelling-catheter introduced, the formalin solution being left in the bladder for 5 to 30 min (mean: 12 min). Haematuria was absent after 1 to 25 days (mean: 11 days) in 9 cases. The 10th patient died before arrest of haemorrhage. Survival after instillation was 65 days to 27 months (mean: 11.5 months). The outcome was fatal within 4 months or less in 3 cases and 4 patients died of renal failure within 3 months, one within 65 days after instillation. In 4 cases, treatment with formalin reduced bladder capacity to less than 100 ml. Other complications included retroperitoneal fibrosis (1 case), urinary incontinence (3 cases) and severe frequency and nocturia (3 cases). This procedure should therefore be reserved for terminal cases unable to support more aggressive therapy.

Administration, Intravesical↗
PubMed1997

Sachse urethrotomy versus endoscopic urethrotomy plus transurethral resection of the fibrous callus (Guillemin's technique) in the treatment of urethral stricture.

OBJECTIVES: Advances in endoscopic instrumentation and technique have expanded the urologist's armamentarium for effective and safe treatment of urethral strictures. This prospective study included 80 patients who presented with single, iatrogenic, annular strictures of the bulbar urethra. The length of the stricture was 1 to 2 cm, with an average of 1.5 cm. METHODS: Patients were randomly divided into two groups: group A, 40 patients who underwent direct-optical endoscopic urethrotomy with a guide catheter via cold-knife incision at the 12 o'clock position (Sachse urethrotomy), and group B, 40 patients who underwent double direct-optical endoscopic urethrotomy with a guide catheter via cold-knife incisions at the 11 and 1 o'clock positions, followed by transurethral resection of all scar tissues (Guillemin's technique). The results obtained were analyzed and compared at 6 months, 12 months, 24 months, 3 years, and 5 years postoperatively by clinical evaluation, uroflowmetry, and retrograde and voiding urethrographies. RESULTS: Group A obtained 95% good results at 6 months, 85% at 12 months, 55% at 24 months, 45% at 3 years, and 25% at 5 years. Group B obtained 98% good results at 6 months, 95% at 12 months, 90% at 24 months, 80% at 3 years, and 70% at 5 years. CONCLUSIONS: The differences between the two groups are not significant at 6 and 12 months (P > 0.05). They are statistically significant after 24 months, 3 years, and 5 years (P < 0.05).

Aged↗
PubMed1997

Six cases of prenatal and neonatal torsion of the spermatic cord.

Torsions of the spermatic cord occurring from the intrauterine period to the end of the first year of life are termed perinatal. These are divided into prenatal and postnatal torsions, depending on their occurrence in the intrauterine or postuterine period. From January 1984 to January 1996, 6 cases were identified at our institution, involving 4 prenatal and 2 postnatal extravaginal torsions of the spermatic cord. These cases are reviewed with regard to optimal therapeutic approaches for the treatment of both the affected gonad as well as the contralateral one, and whether the event occurred prenatally or postnatally. The authors also propose several clinical indications useful for obstetricians, pediatricians, urologists and nurses.

Age of Onset↗
PubMed1996

Squamous cell carcinoma of the penis arising from balanitis xerotica obliterans.

Penile squamous cell carcinoma arising from balanitis xerotica obliterans is rarely reported. We describe a 58-year-old man in whom penile squamous cell carcinoma developed after 25 years of observation for balanitis xerotica obliterans. It is important to recognize the possibility of this uncommon complication of balanitis xerotica obliterans, because survival of patients with squamous cell carcinoma depends on early diagnosis and treatment.

Balanitis↗