Biomedical subjects
Publications and source records attributed to B D Joyner.
A novel circumcision technique using the Plastibell as a template is described. This technique is fast and ensures excellent cosmesis compared with the standard sleeve circumcision. It is easy to perform and allows the urologist to achieve consistently excellent cosmetic results. We describe the technique in detail.
PURPOSE: Loss of bladder compliance from hypercontractility and fibrosis may represent an injury response to excessive intravesical pressure. Together, interactions between cell and extracellular matrix components regulate cell response to injury and extracellular matrix remodeling. The receptor for hyaluronic acid mediated motility (RHAMM) is a recently described hyaluronic acid binding protein known to influence multiple types of cell extracellular matrix interaction in development, injury and cancer. We evaluate the role of RHAMM in mediating early events in bladder stretch injury. MATERIALS AND METHODS: An acute stretch injury model was used. The rat bladder was injured by hydrodistention inducing gross hematuria. Tissues were analyzed for temporal and spatial expression of RHAMM in the mucosa and detrusor regions by immunostaining, western and reverse transcriptase polymerase chain reaction analyses. The contractile activity of smooth muscle cell primary cultures was analyzed using a gel contraction assay in the presence of peptide fragments known to block RHAMM function. RESULTS: Acute hydrodistention caused immediate and significant injury to the bladder, with fracturing of smooth muscle cell bundles, edema and hemorrhage. RHAMM immunolocalized to the mucosa and detrusor within 2 hours of injury, peaking by 5 to 10 hours. A shift from low molecular weight (55 kD.) to high (120 kD.) receptor isoforms was prominent during the peak expression period noted by immunolocalization. RHAMM messenger ribonucleic acid increased only slightly (40%) by 5 hours after injury. Smooth muscle cell primary cultures actively initiated and maintained the contraction of collagen gels by more than 75% of baseline in vitro. Blocking RHAMM function significantly inhibited the ability to less than 25% of smooth muscle cells to contract the gels in vitro. CONCLUSIONS: Increased expression of RHAMM is an early event precipitated by stretch injury to the bladder. Since extracellular matrix hyaluronic acid is found early in tissue repair responses, its receptor RHAMM may be mediating initial bladder responses to stretch injury, some of which (contraction) may be experimentally blocked in vitro. Since the receptor directly regulates protein kinase signaling which in turn mediates smooth muscle cell contraction and collagen synthesis, further studies of RHAMM function in bladder pathology are warranted.
Recent advancements in surgical and medical therapies have improved the life expectancy of children with myelomeningocele. Yet, there has been a contrasting lack of improvement with regards to sexual function and reproductive issues that continue to infantilize this population. This article identifies five major risk factors that contribute to these delays which invariably lead to irreversible emotional trauma if they are not addressed early in childhood. Adequate psychosexual education of myelomeningocele patients and their families is a tremendous societal challenge. But, only with education will there be trends away from policies of isolation to those that reinforce community integration of the physically disabled.
The endoscopic treatment of reflux, like that of urinary incontinence, is effective. Several materials and endoscopic delivery systems are currently under evaluation for the treatment of reflux and incontinence. These include silicone microimplants, glass particles, collagen, dextranomer microspheres, a detachable balloon system, chondrocytes, and muscle cells. Although the endoscopic treatment is rendered in a similar fashion for both urinary incontinence and reflux, the acceptable safety and efficacy parameters of the bulking agents may differ, depending on the condition treated and the age of the patient. A review of the endoscopic bulking substances and systems currently available is presented.
PURPOSE: Resolution of reflux in meningomyelocele patients is a reflection of improved bladder storage. We correlated resolution of reflux with changes observed in sequential urodynamic studies. MATERIALS AND METHODS: The study included 27 children with meningomyelocele born between 1975 and 1985 who presented with or developed vesicoureteral reflux. Resolution of reflux was observed during the 10-year followup period as they were treated with a regimen of clean intermittent catheterization and pharmaco-therapy. Urodynamic studies were performed when vesicoureteral reflux was present and subsequent to its resolution. The urodynamic parameters compared in the 2 studies included bladder capacity, pressure specific bladder volume, bladder compliance and leak point pressure. RESULTS: Significant increases in bladder capacity, pressure specific bladder volume and bladder compliance were noted. Leak point pressure appeared to be decreased subsequent to resolution of reflux. CONCLUSIONS: Resolution of reflux in meningomyelocele patients correlates with changes in parameters of bladder storage observed on sequential urodynamic studies.
Dense masses of spores of Dictyostelium mucoroides var. stoloniferum have the ability to germinate and aggregate rapidly in the absence of food. This is made possible by the presence of a dominant, self-produced spore germination activator. The germination-aggregation cycle can be repeated in as many as six successive generations. In each generation the spore size is reduced so that ultimately they are only a fraction of the size of those produced by the parental, bacteria-fed amoebae.