Christos E. Constantinou

Learn More
We localized the temporal and spatial distribution of pressures in the urethra to identify their contribution to continence. With the data obtained we resolved the timing between the passively transmitted and actively generated urethral pressures. Data were obtained from 11 healthy female volunteers, with a mean age of 22 years. Simultaneous measurements of(More)
The age related effects of 17beta-estradiol (E) supplementation on micturition and contractility of ovariectomized rats (OVX) were evaluated. Studies were carried out in young, 2 month, and mature, 10 month old rats which were distributed into three groups: Sham-operated (SHAM), (OVX), and (OVX+E). Following treatment, urodynamic studies were performed(More)
BACKGROUND Current measurement tools have difficulty identifying the automatic physiologic processes maintaining continence, and many questions still remain about pelvic floor muscle (PFM) function during automatic events. OBJECTIVE To perform a feasibility study to characterise the displacement, velocity, and acceleration of the PFM and the urethra(More)
We present a biosensor intended to evaluate prostatic stiffness. The stiffness of the prostate was modulated using hormonal induction and adrenergic stimulation. The results show that the sensor can be sufficiently accurate to discriminate between soft prostates used as controls and those stiffened with hormones. The modulation produced by an adrenergic(More)
Real time ultrasound imaging is one of the many ways to clinically evaluate the anatomical and functional condition of female pelvic floor in patients with urinary incontinence. Reflex arc testing of the displacement of uro-gynecological structures during imaging provides a non-invasive way of visualizing their motility. The response from such tests(More)
CONSTANTINOU, c. E. Renal pelvic pacemaker control of ureteral peristaltic rate. Am. J. Physiol. 226(6): 1413-1419. l974.-To gain insight into the mechanism responsible for the generation of ureteral peristalsis, a canine experimental model was constructed using manometric methods in the evaluation of the fundamental renal pelvic rhythm and the(More)
The pacemaker properties of the various regions of isolated segments of the rabbit renal pelvis were examined. The results show that pacemaker frequency and waveform of contraction change significantly within the renal pelvis. The highest frequency was encountered at the fornix, while the ureteropelvic junction is lowest.
PURPOSE The pelvic tissue of women with pelvic organ prolapse is stiffer than that of controls but there are scant data on the collagen composition that corresponds to these mechanical properties. We evaluated human vaginal wall stiffness using the novel scanning haptic microscope and correlated these measurements to collagen expression in women with and(More)
The characteristics of spontaneous contractility in the renal pelvis were examined in the unicalyceal kidney of the rabbit. In vitro isometric studies were done on whole as well as renal pelvic segments dissected longitudinally and radially. The results show that the contractile frequency of isolated segments was highest in the proximal region (4.188 +/-(More)
In this review the diagnostic potential of evaluating female pelvic floor muscle (PFM) function using magnetic and ultrasound imaging in the context of urodynamic observations is considered in terms of determining the mechanisms of urinary continence. A new approach is used to consider the dynamics of PFM activity by introducing new parameters derived from(More)