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  • 1
    Electronic Resource
    Electronic Resource
    Weiterentwicklung des transrektalen Ultraschalls Artifizielle neuronale Netzwerkanalyse (ANNA) in der Erkennung und Stadieneinteilung des Prostatakarzinoms (2000)
    Springer
    Der Urologe 39 (2000), S. 341-347 
    Details
    ISSN: 1433-0563
    Keywords: Schlüsselwörter Prostataspezifisches Antigen ; Transrektaler Ultraschall ; Artifizielle Neuronale Netzwerkanalyse ; Key words Prostate specific antigen ; Transrectal ultrasound ; Artificial neural network analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract As a result of the enhanced clinical application of prostate specific antigen (PSA), an increasing number of men are becoming candidates for prostate cancer work-up. A high PSA value over 20 ng/ml is a good indicator of the presence of prostate cancer, but within the range of 4–10 ng/ml, it is rather unreliable. Even more alarming is the fact that prostate cancer has been found in 12–37% of patients with a “normal” PSA value of under 4 ng/ml (Hybritech). While PSA is capable of indicating a statistical risk of prostate cancer in a defined patient population, it is not able to localize cancer within the prostate gland or guide a biopsy needle to a suspicious area. This necessitates an additional effective diagnostic technique that is able to localize or rule out a malignant growth within the prostate. The methods available for the detection of these prostate cancers are digital rectal examination (DRE) and Transrectal ultasound (TRUS). DRE is not suitable for early detection, as about 70% of the palpable malignancies have already spread beyond the prostate. The classic problem of visual interpretation of TRUS images is that hypoechoic areas suspicious for cancer may be either normal or cancerous histologically. Moreover, about 25% of all cancers have been found to be isoechoic and therefore not distinguishable from normal-appearing areas. None of the current biobsy or imaging techniques are able to cope with this dilemma. Artificial neural networks (ANN) are complex nonlinear computational models, designed much like the neuronal organization of a brain. These networks are able to model complicated biologic relationships without making assumptions based on conventional statistical distributions. Applications in Medicine and Urology have been promising. One example of such an application will be discussed in detail: A new method of Artificial Neural Network Analysis (ANNA) was employed in an attempt to obtain existing subvisual information, other than the gray scale, from conventional TRUS and to improve the accuracy of prostate cancer identification.
    Notes: Zusammenfassung Das prostataspezifische Antigen (PSA) ist heutzutage der meistgenutzte Marker in der Diagnostik des Prostatakarzinoms. Hieraus resultiert eine vermehrte Anzahl von asymptomatischen Männern, die allein durch eine PSA-Werterhöhung Kandidaten für eine weiterführende Prostatadiagnostik werden. Ein deutlich erhöhter PSA-Serumwert (〉20 ng/ml) lässt mit hoher Wahrscheinlichkeit auf das Vorhandensein eines Prostatakarzinoms schließen. Im sog. Graubereich zwischen 4 und 10 ng/ml ist der Gewebemarker PSA meist durch gutartige Veränderungen beeinflusst, so dass eine Unterscheidung zwischen maligner und benigner Ursache aufgrund des PSA-Wertes allein nicht möglich ist [1–4]. Darüber hinaus findet man Karzinome bei Patienten, die ein PSA unter dem Normwert von 4 ng/ml aufweisen. Die Methoden, die bislang für die Früherkennung oder Erkennung des Prostatakarzinoms zur Verfügung standen (Tastbefund und Ultraschall) sind unzureichend. So sind ca. 70% der palpablen Tumoren nicht mehr organbegrenzt [5, 6]. Das klassische Problem der visuellen Ultraschallbeurteilung ist die mangelnde Spezifität, insbesondere bei geringer Erfahrung mit der Methode [7–11]. Um die diagnostischen Möglichkeiten des transrektalen Ultraschalls (TRUS) in der Prostatakarzinom-Früherkennung und -Stadieneinteilung zu erhöhen, wird in der hier vorgestellten Studie eine Artifizielle Neuronale Netzwerkanalyse (ANNA) eingesetzt, die zusätzliche subvisuelle, graustufendifferente Informationen des TRUS erfassen und auswerten kann [12–14]. Dieser Ansatz erscheint vielversprechend, da Artifizielle Neuronale Netzwerke die im Ultraschallbild vorhandenen komplexen Datenformationen erkennen können, sie gleichsam “lernen” und diese dann bei noch nicht gesehenen Datenformationen wiedererkennen und korrekt klassifizieren können [15].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001200050367
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  • 2
    Electronic Resource
    Electronic Resource
    Current controversies in nephron-sparing surgery for renal-cell carcinoma (1995)
    Springer
    World journal of urology 13 (1995), S. 163-165 
    Details
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of nephron-sparing surgery for renal cell carcinoma is well established in patients with an anatomical or functional solitary kidney (imperative indication) in which a radical nephrectomy would render the patient anephric with subsequent need for hemodialysis. This also encompasses patients with a unilateral renal cell carcinoma and a functioning contralateral kidney when the opposite renal unit is affected by a disease that might threaten its future function, such as renal artery stenosis, chronic pyelonephritis, stone disease or systemic conditions such as diabetes. A functioning renal remant of at least 20% of normal renal parenchyma seems to be necessary to avoid end-stage renal failure in these patients [16]. There have been several reports in the literature of excellent 5-year cancer-specific survival rates of over 80% in such circumstances [12, 15]. These results were confirmed in our institution, with a 5-year cancer-specific survival rate of 83% in over 70 patients with an imperative indication for nephron-sparing surgery. Thereby the prognosis was significantly influenced by the local tumor stage and the grade of malignancy. These data support the efficacy of nephron-sparing surgery in this clinical situation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00184872
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  • 3
    Electronic Resource
    Electronic Resource
    Social integration, sexual behaviour and fertility in patients with bladder exstrophy – a long-term follow up (1996)
    Springer
    European journal of pediatrics 155 (1996), S. 678-683 
    Details
    ISSN: 1432-1076
    Keywords: Key words Bladder exstrophy ; Interpersonal relations ; Sexual ; behaviour ; Fertility and education
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract After primary bladder closure or urinary diversion, other factors apart from the reconstruction itself gain importance for individuals with the exstrophy-epispadias complex: social integration and, after reaching puberty, sexuality and fertility. Between 1968 and July 1994 115 patients with bladder exstrophy or incontinent epispadias underwent surgery at our institution. A total of 104 patients could be followed, 2 of whom died in the meantime. Of the remaining 102 patients 48 attend school, 4 are in college, 40 have completed or are currently undergoing vocational training, 3 are unemployed, 1 lives in a therapeutic centre and 6 are younger than 6 years of age. A total of 95% of the patients with continent urinary diversion are continent day and night, whereas only three of five patients with a sling plasty (incontinent epispadias) or with primary bladder closure followed by a Young-Dees procedure are continent. None of the patients showed deterioration of renal function. In 25 females the external genitalia were reconstructed. Fixation of the uterus was done in 13 to correct or prevent uterine prolapse. Of the 17 women older than 18 years of age with genital reconstruction, 16 are satisfied with the cosmetic result. All adults engage in sexual intercourse. Five women have delivered seven children by Caesarean section. Of the 35 male adults 32 underwent reconstruction of the external genitalia and 34 males achieve erection. One developed necrosis of the penis early in life following primary bladder closure performed at an outside hospital. Penile deviation was present in 11 of the 32 patients with genital reconstruction, which is distressing in only 2. Thirty patients are satisfied with the cosmetic result. After genital reconstruction 9 males developed epididymitis, necessitating two orchiectomies and three vasectomies. No patient with reconstruction of the external genitalia can ejaculate normally or has fathered children, whereas ejaculation was normal in the three men who did not undergo genital reconstruction and in two patients prior to post-pubertal reconstruction. Furthermore, two of these three men have fathered four children. Conclusion Education, occupation and social development of patients with urinary diversion are uneventful. The cosmetic results achieved by genital reconstruction are satisfactory. In female patients, antefixation of the uterus should be performed before or together with an introitusplasty to prevent uterine prolapse. In male patients, however, surgery is performed at the expense of fertility. Detailed discussions with the patients and their parents should include not only the question of primary bladder closure versus urinary diversion, but also the pros and cons of correction of the external and – in females – the internal genitalia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01957152
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Social integration, sexual behaviour and fertility in patients with bladder exstrophy —a long-term follow up (1996)
    Springer
    European journal of pediatrics 155 (1996), S. 678-683 
    Details
    ISSN: 1432-1076
    Keywords: Bladder exstrophy ; Interpersonal relations ; Sexual behaviour ; Fertility and education
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract After primary bladder closure or urinary diversion, other factors apart from the reconstruction itself gain importance for individuals with the exstrophy-epispadias complex: social integration and, after reaching puberty, sexuality and fertility. Between 1968 and July 1994 115 patients with bladder exstrophy or incontinent epispadias underwent surgery at our institution. A total of 104 patients could be followed, 2 of whom died in the meantime. Of the remaining 102 patients 48 attend school, 4 are in college, 40 have completed or are currently undergoing vocational training, 3 are unemployed, 1 lives in a therapeutic centre and 6 are younger than 6 years of age. A total of 95% of the patients with continent urinary diversion are continent day and night, whereas only three of five patients with a sling plasty (incontinent epispadias) or with primary bladder closure followed by a Young-Dees procedure are continent. None of the patients showed deterioration of renal function. In 25 females the external genitalia were reconstructed. Fixation of the uterus was done in 13 to correct or prevent uterine prolapse. Of the 17 women older than 18 years of age with genital reconstruction, 16 are satisfied with the cosmetic result. All adults engage in sexual intercourse. Five women have delivered seven children by Caesarean section. Of the 35 male adults 32 underwent reconstruction of the external genitalia and 34 males achieve erection. One developed necrosis of the penis early in life following primary bladder closure performed at an outside hospital. Penile deviation was present in 11 of the 32 patients with genital reconstruction, which is distressing in only 2. Thirty patients are satisfied with the cosmetic result. After genital reconstruction 9 males developed epididymitis, necessitating two orchiectomies and three vasectomies. No patient with reconstruction of the external genitalia can ejaculate normally or has fathered children, whereas ejaculation was normal in the three men who did not undergo genital reconstruction and in two patients prior to post-pubertal reconstruction. Furthermore, two of these three men have fathered four children.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01957152
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
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