China
Africa
Explore chapters and articles related to this topic
Tissue Engineering and Application in Tropical Medicine
Published in Rajesh K. Kesharwani, Raj K. Keservani, Anil K. Sharma, Tissue Engineering, 2022
Urinary bladder carcinoma is another important cancer in urinary tract. The tropical infection, blood fluke, Schistosoma haematobium, is confirmed as a carcinogenic factor for urinary bladder carcinoma. The management of urinary bladder cancer usually requires surgical management. The use of tissue engineering and stem cell therapy in management of urinary bladder carcinoma is the new approach (Singh et al., 2018). The neourinary conduit is the good example of tissue engineering application. The neourinary conduit is constructed by novel tissue engineering technology and grafting implantation is needed for therapeutic application. The aim of implantation of neourinary conduit is to regain appropriate biological and mechanical properties for storage and transportation of urine (Singh et al., 2018). Nevertheless, there are still many present problems in using graft from tissue engineering technology. Graft ischemia is a big problem and if the ischemia occurs, it might result in fibrosis or perforation (Alberti, 2016).
Designing for Lower Torso and Leg Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Bladder control and emptying problems are common. In addition to urinary retention, discussed in Section 5.3.1, voiding difficulties, which tend to increase with age for both men and women, include overactive bladder (OAB) and three classes of urinary incontinence: (a) urgency urinary incontinence (urgency UI), (b) stress urinary incontinence (stress UI), and (c) mixed urinary incontinence (mixed UI). The much longer male urethra may make men less prone to incontinence than women—from all incontinence causes (Irwin, Kopp, Agatep, Milsom, & Abrams, 2011; Tennstedt, Link, Steers, & McKinlay, 2008). The volume and duration of the urine loss with each of these problems can vary, from person to person as well as from one incontinent episode to another. A best-case scenario for IMPs for urinary incontinence would be gender-specific products to effectively collect variable urine amounts over variable periods of time. Extrapolating from 2008 data; Irwin et al. (2011) estimate that worldwide, as of 2018, 423 million people will suffer some form of incontinence (p. 1132).
Hydrostatic Pressure and Its Role in Physiology and Pathology
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
The urinary bladder serves as a storage vessel for urine until it is expelled from the body. Typically, urine is stored for 4–5 hour intervals at low pressure. As the volume of urine increases within the bladder lumen, the storage pressure also increases until a threshold pressure is achieved, initiating activation of afferent nerves signaling the brain that the bladder is full (30). Upon voiding, contraction of bladder smooth muscle produces a sharp escalation in intravesical pressure (55). A urodynamic study conducted on 38 healthy human patients determined the storage pressure at bladder capacity (threshold pressure) to be between 3 and 16 cmH2O, while the intravesical pressure at maximum flow rate (PdetQmax) (voiding pressure) ranged between 17 and 48 cmH2O (35). However, diseases such as benign prostate hyperplasia (BPH) restrict the diameter of the urethra, resulting in partial bladder outlet obstruction (pBOO), characterized by elevated pressures during storage (3–25 cmH2O) and voiding (35–88 cmH2O) (35).
Association between high-heeled shoes of varied heel height and bladder neck elevation in women: an exploratory study
Published in Footwear Science, 2019
Priya Kannan, Brigitte Fung, Regina W.C. Leung, Ravindra Goonetilleke, Stanley J. Winser
Pelvic floor muscle (PFM) laxity can result in hypermobility of bladder neck (Balmforth, Mantle, Bidmead, & Cardozo, 2006; Hung, Hsiao, Chih, Lin, & Tsauo, 2011). Correct positioning of the bladder neck is crucial for equal transmission of increasing intra-abdominal pressure to the bladder and urethra (Balmforth et al., 2006; Enhorning, 1961; Hung et al., 2011). Increases in intra-abdominal pressure that occur during strenuous activities (strenuous exercise, sneezing, coughing or laughing) are transmitted to urethra and can enhance urethral closure, provided the bladder neck position is above the pelvic floor (Enhorning, 1961; Hung et al., 2011; McLean et al., 2013). However, if the pelvic floor is higher than the bladder neck position, greater pressure is transmitted to the bladder than to the urethra, reducing the urethral closure and continence status (Enhorning, 1961; Hung et al., 2011).
A two way fully coupled fluid structure simulation of human ureter peristalsis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Ahmed Tasnub Takaddus, Abhilash J. Chandy
The ureter is approximately a 30 cm long tube that connects the kidney to the bladder (Guyton and Hall 2006). Urine is carried through the ureter with isolated boluses moving from kidney to the bladder (van Mastrigt and Tauecchio 1984), known as the peristalsis mechanism. Understanding the peristaltic mechanism is critical, considering the improvement of treatment procedures for anomalies related to ureter peristalsis; say for instance, back-flow of urine from bladder to kidney known as vesicoureteric reflux or, malfunctioning of ureterobesical junction due to congentinal defects (Marieb et al. 2013). Various numerical studies have been performed to understand the urine transport mechanism. Earlier studies only included the fluid domain, and the ureter was modeled as channels or pipes. A lot of these studies modeled ureter peristalsis as a continuous series of sinusoidal waves (Burns and Parkes 1967; Fung and Yih 1968; Yin and Fung 1969; Chow 1970; Shapiro et al. 1969; Jimenez Lozano 2009; Najafi 2015; Najafi et al. 2016). Lykoudis and Roos 1970 was the first to point out that, peristalsis is not a sinusoidal function, and they presented it as an algebraic expression. Griffiths 1987; Griffiths 1989 studied the peristaltic motion and described it as a series of compression waves.
Effect of bladder and rectal loads on the vaginal canal and levator ani in varying pelvic floor conditions
Published in Mechanics of Advanced Materials and Structures, 2018
Arnab Chanda, Vinu Unnikrishnan
The effect of bladder and rectal loads were studied for the pelvic floor muscle (levator ani) in normal pelvic floor conditions. With increased bladder loading and no rectal loading, the stress concentration and displacements on the levator ani (Figure 13) were found to increase with maximum displacement going up from 0.22 mm to 0.49 mm. The maximum displacement concentration zone was observed to be close to the posterior attachment of the levator ani at the coccyx. This finding indicated that in severe bladder loading conditions due to prolapse, there might be a high chance of pelvic floor failure initiating at the coccyx region. Also, a high stress and displacement region observed close to the anterior puborectalis section of the levator ani (which supports the urethra, vaginal and rectal hiatus) may indicate high-induced obstructions at the bladder, vaginal and rectal hiatus regions leading to pressure and hence difficulty emptying the bladder and SUI [7].