Prognostic Factors for the Development of Biochemical Recurrence after Radical Prostatectomy

Prostate cancer is one of the most common cancers in Western countries and is associated with a considerable risk of mortality. Biochemical recurrence following radical prostatectomy is a relatively common finding, affecting approximately 25% of cases. The aim of our paper was to identify factors that can predict the occurrence of biochemical recurrence, so the patient can be properly counselled pre- and postoperatively. Medline review of the literatures was done followed by a group discussion on the chosen publications and their valuable influence. Preoperative serum total PSA and clinical stage, together with prostatectomy Gleason grade, tumour volume, and perineural and vascular invasions, were the most important variables found to influence outcome

Clinical ROC Studies of Digital Stereo Mammography

The objective of this study was to explore and document the diagnostic utility of digital stereo mammography for the detection of localized breast cancer in women. In it we character­ized the ability of experienced mammographers, general radiologists, and non-radiologists to detect three types of tumor masses embedded within a heterogeneous background of normal tis­sue elements in numerically simulated digital mammograms. The simulated mammograms were displayed to the subjects on a high resolution video display, both in stereo mode and in mono mode. Half of the mammograms contained a single tumor, ranging from 0.3 to 0.8 cm in maxi­mal diameter. Each reader rated 120 images (60 in stereo and 60 in mono) as to the probability of abnormality on scale of 1-5. Observer responses were evaluated using receiver operating characteristic (ROC) analysis to characterize any difference in diagnostic performance between the two viewing modes. The synthesized mammograms and the digital display were highly rated by the participant radiologists as promising tools for future research. The results of ROC analysis, however, indicated no significant difference in tumor detection when the same readers utilized the stereo mode versus the mono mode (Az mono = 0.833 versus, Az stereo = 0.826). The results were similar for readers of all 3 experience levels--mammographers, general radiolo­gists, and non-radiologists

Classification of Focal Prostatic Lesions on Transrectal Ultrasound (TRUS) and the Accuracy of TRUS to Diagnose Prostate Cancer

Objective: To improve the diagnostic efficacy of transrectal ultrasound (TRUS)-guided targeted prostatic biopsies, we have suggested the use of a new scoring system for the prediction of malignancies regarding the characteristics of focal suspicious lesions as depicted on TRUS. Materials and Methods: A total of 350 consecutive patients with or without prostate cancer who underwent targeted biopsies for 358 lesions were included in the study. The data obtained from participants were randomized into two groups; the training set (n = 240) and the test set (n = 118). The characteristics of focal suspicious lesions were evaluated for the training set and the correlation between TRUS findings and the presence of a malignancy was analyzed. Multiple logistic regression analysis was used to identify variables capable of predicting prostatic cancer. A scoring system that used a 5-point scale for better malignancy prediction was determined from the training set. Positive predictive values for malignancy prediction and the diagnostic accuracy of the scored components with the use of receiver operating characteristic curve analysis were evaluated by test set analyses. Results: Subsequent multiple logistic regression analysis determined that shape, margin irregularity, and vascularity were factors significantly and independently associated with the presence of a malignancy. Based on the use of the scoring system for malignancy prediction derived from the significant TRUS findings and the interactions of characteristics, a positive predictive value of 80% was achieved for a score of 4 when applied to the test set. The area under the receiver operating characteristic curve (AUC) for the overall lesion score was 0.81. Conclusion: We have demonstrated that a scoring system for malignancy prediction developed for the characteristics of focal suspicious lesions as depicted on TRUS can help predict the outcome of TRUS-guided biopsies.This study was supported by the Seoul National University Bundang Hospital Research Fund (Grant No. 02-2006-031).Mitterberger M, 2007, J UROLOGY, V178, P464, DOI 10.1016/j.juro.2007.03.107Djavan B, 2007, WORLD J UROL, V25, P11, DOI 10.1007/s00345-007-0151-1Shim HB, 2007, TUMORI, V93, P178Toi A, 2007, J UROLOGY, V177, P516, DOI 10.1016/j.juro.2006.09.061Lee HJ, 2006, J ULTRAS MED, V25, P815Elabbady AA, 2006, EUR UROL, V49, P49, DOI 10.1016/j.eururo.2005.08.013Halpern EJ, 2005, CANCER, V104, P2373, DOI 10.1002/cncr.21440Ozden E, 2005, J CLIN ULTRASOUND, V33, P5, DOI 10.1002/jcu.20080Kuligowska E, 2001, RADIOLOGY, V220, P757Lavoipierre AM, 1998, AM J ROENTGENOL, V171, P205Plawker MW, 1997, J UROLOGY, V158, P1853Cornud F, 1997, UROLOGY, V49, P709NEWMAN JS, 1995, RADIOLOGY, V195, P86LITTRUP PJ, 1992, CA-CANCER J CLIN, V42, P198HAMPER UM, 1991, RADIOLOGY, V180, P101LEE F, 1991, CANCER, V67, P1132RIFKIN MD, 1988, RADIOLOGY, V166, P619

An unsupervised map of excitatory neuron dendritic morphology in the mouse visual cortex

Neurons in the neocortex exhibit astonishing morphological diversity, which is critical for properly wiring neural circuits and giving neurons their functional properties. However, the organizational principles underlying this morphological diversity remain an open question. Here, we took a data-driven approach using graph-based machine learning methods to obtain a low-dimensional morphological “bar code” describing more than 30,000 excitatory neurons in mouse visual areas V1, AL, and RL that were reconstructed from the millimeter scale MICrONS serial-section electron microscopy volume. Contrary to previous classifications into discrete morphological types (m-types), our data-driven approach suggests that the morphological landscape of cortical excitatory neurons is better described as a continuum, with a few notable exceptions in layers 5 and 6. Dendritic morphologies in layers 2–3 exhibited a trend towards a decreasing width of the dendritic arbor and a smaller tuft with increasing cortical depth. Inter-area differences were most evident in layer 4, where V1 contained more atufted neurons than higher visual areas. Moreover, we discovered neurons in V1 on the border to layer 5, which avoided deeper layers with their dendrites. In summary, we suggest that excitatory neurons’ morphological diversity is better understood by considering axes of variation than using distinct m-types

TRANSRECTAL ULTRASOUND-GUIDED BIOPSY A PROSPECTIVE STUDY OF PATIENTS TOLERANCE AND COMPLICATIONS

Objectives To determine the morbidity and patient tolerance of TRUS-guided biopsy from suspected malignant prostate or pelvic recurrence after radical cystectomy. Patients and Methods This prospective study comprised 113 patients who underwent TRUS-guided biopsy from the prostate or from pelvic recurrence following radical cystectomy. The patients' tolerance was assessed by scoring the severity of discomfort during the procedure and their acceptance was estimated by questionnaires following it. Results Most patients (56.6%) experienced either no discomfort at all or only mild pain during the procedure. Intravenous sedation was needed in 31% of the patients and general anaesthesia was necessary in two patients. Haematuria was the commonest complication (59.6%) followed by rectal bleeding and haemospermia, which occurred in 36.7% and 17.4% of the patients, respectively. A vasovagal attack occurred in one patient. There was one major complication, a prostatic abscess which resulted in a temporary urethro-rectal fistula. Conclusion TRUS-guided core biopsy is safe with frequent minor but` very rare major complications. The majority of the patients tolerate the procedure with accepted discomfort but a considerable number of patients need sedation to complete the procedure effectively. African Journal of Urology Vol. 7 No. 2 (May 2001): pp 57-61Biopsie Transrectale Echoguidée: Etude Prospective de la Tolérance des Patients et des ComplicationsObjectif Evaluer la tolérance et l'acceptance des patients de la biopsie transrectale échoguidée. Patients et Méthodes Cette étude prospective comprenait 113 patients qui ont bénéficié d'une biopsie transrectale échoguidée de la prostate ou d'une récurrence pelvienne après cystectomie radicale. La tolérance des patients était évaluée en cotant la sévérité du disconfort pendant la procé-dure et leur acceptance était estimée par des questionnaires ensuite. Résultats La plupart des patients (56,6%) ne ressentaient pas du tout de disconfort ou ressentaient seulement une douleur mineure pendant la procédure. Une sédation intraveineuse a été nécessaire chez 31% des patients et une anesthésie générale a été nécessaire dans 2 cas. L'hématurie était la complication la plus fré-quente, suivie de rectorragies et d'hématospermie survenues chez 36,7% et 17,4% des patients, respectivement. Une attaque vaso-vagale est survenue chez un patient. Il y avait une complication majeure: un abcès prostatique ayant évolué à une fistule uréthro-rectale temporaire. Conclusion La biopsie transrectale échoguidée est anodine, ses complications mineures sont fréquentes mais les complications majeures sont très rares. La majorité des patients tolèrent la procédure avec disconfort accepté mais un nombre considérable de patients nécessitent une sédation pour compléter efficace-ment la procédure. African Journal of Urology Vol. 7 No. 2 (May 2001): pp 57-6

A computer model to predict strength-duration curve parameters from measured data

The threshold strength for an electric or magnetic (electrodeless) stimulus is related to its duration by the strength-duration (s-d) curve. Two common mathematical expressions are used to describe the s-d curve; the first is exponential in form while the second is hyperbolic in form. Classically, the rectangular pulse has been used to determine strength-duration curves. However, recent applications have required the use of more complex waveforms, and the ability of these s-d curves to adequately describe tissue response to more complex waveforms has been questioned. Single-axon and single-cell models, first introduced by Hodgkin and Huxley (1952), were used in several computer models to simulate the process of tissue excitation. The single-cell models contain parameters empirically derived from voltage-clamped measurements on single-cells. It may be inappropriate to use the parameters derived from single-cells to model excitation in more complex geometry tissue. These observations have caused us to re-examine the classical view of stimulation, and in particular, to appreciate the need for a more sophisticated framework in which to interpret results. Our goal is to simplify the existing models based on single-cell and single-axon responses and use it to extend the s-d model in its exponential form to enable prediction of the s-d curve for non-rectangular stimuli. Our new model is called The Extended and Simplified Non-Linear (ESN) model for tissue stimulation . The ESN model contains parameters, analogous to those forming the basis of the single-cell and single-axon models, but differs from the existing models in that the value of key parameters are calculated directly from data measured in complex vital systems. In a subsequent effort we adapt the parameters extracted from the experimental data to build a computer program to predict thresholds for complex stimulus waveforms. A view of the proposed model can be divided in two sections, the first is a backward direction one in which values for the parameters are extracted from measured data. The second part of the model is a forward direction model, in which the parameters from the first part have been adapted in a special formulation to be used in predicting stimulation thresholds for complex waveforms