Investigation of Fiber-Driven Mechanical Behavior of Human and Porcine Bladder Tissue Tested Under Identical Conditions.

The urinary bladder is a highly dynamic organ that undergoes large deformations several times per day. Mechanical characteristics of the tissue are crucial in determining the function and dysfunction of the organ. Yet, literature reporting on the mechanical properties of human bladder tissue is scarce and, at times, contradictory. In this study, we focused on mechanically testing tissue from both human and pig bladders using identical protocols to validate the use of pigs as a model for the human bladder. Furthermore, we tested the effect of two treatments on tissue mechanical properties. Namely, elastase to digest elastin fibers, and oxybutynin to reduce smooth muscle cell spasticity. Additionally, mechanical properties based on the anatomical direction of testing were evaluated. We implemented two different material models to aid in the interpretation of the experimental results. We found that human tissue behaves similarly to pig tissue at high deformations (collagen-dominated behavior) while we detected differences between the species at low deformations (amorphous matrix-dominated behavior). Our results also suggest that elastin could play a role in determining the behavior of the fiber network. Finally, we confirmed the anisotropy of the tissue, which reached higher stresses in the transverse direction when compared to the longitudinal direction.

Absence of plateau potentials in dLGN cells leads to a breakdown in retinogeniculate refinement.

The link between neural activity and the refinement of projections from retina to the dorsal lateral geniculate nucleus (dLGN) of thalamus is based largely on studies that disrupt presynaptic retinogeniculate activity. Postsynaptic mechanisms responsible for implementing the activity-dependent remodeling in dLGN remain unknown. We tested whether L-type Ca(2+) channel activity in the form of synaptically evoked plateau potentials in dLGN cells is needed for remodeling by using a mutant mouse that lacks the ancillary ß3 subunit and, as a consequence, has highly reduced L-type channel expression and attenuated L-type Ca(2+) currents. In the dLGNs of ß3-null mice, glutamatergic postsynaptic activity evoked by optic tract stimulation was normal, but plateau potentials were rarely observed. The few plateaus that were evoked required high rates of retinal stimulation, but were still greatly attenuated compared with those recorded in age-matched wild-type mice. While ß3-null mice exhibit normal stage II and III retinal waves, their retinogeniculate projections fail to segregate properly and dLGN cells show a high degree of retinal convergence even at late postnatal ages. These structural and functional defects were also accompanied by a reduction in CREB phosphorylation, a signaling event that has been shown to be essential for retinogeniculate axon segregation. Thus, postsynaptic L-type Ca(2+) activity plays an important role in mediating the refinement of the retinogeniculate pathway.

Delivery of a massive urinary stone from an augmented bladder using obstetrical forceps.

A 48-year-old man presented for evaluation of an expanding abdominal mass. Twenty years earlier, he had developed Fournier's gangrene requiring extensive debridement. He underwent augmentation cystoplasty with a catheterizable stoma due to a proximal urethral stricture. Fifteen years later, he was found to have a 14 cm x 18 cm bladder augment calculus. Simpson obstetric forceps were passed into the augment to deliver a 1110 gram stone with minimal devitalization of the colonic augmentation tissue. This is the first report of stone management with obstetric forceps in an augmented bladder. The specimen itself is among the largest stones ever reported.

Analysis of the distal urinary tract in larval and adult zebrafish reveals homology to the human system.

Little is known about the distal excretory component of the urinary tract in Danio rerio (zebrafish). This component is affected by many human diseases and disorders of development. Here, we have undertaken multi-level analyses to determine the structure and composition of the distal urinary tract in the zebrafish. In silico searches identified uroplakin 1a (ukp1a), uroplakin 2 (upk2) and uroplakin 3b (upk3b) genes in the zebrafish genome (orthologues to genes that encode urothelium-specific proteins in humans). In situ hybridization demonstrated ukp1a expression in the zebrafish pronephros and cloaca from 96 h post-fertilization. Haematoxylin and Eosin staining of adult zebrafish demonstrated two mesonephric ducts uniting into a urinary bladder that leads to a distinct urethral opening. Immunohistochemistry identified Uroplakin 1a, Uroplakin 2 and GATA3 expression in zebrafish urinary bladder cell layers that match human urothelial expression. Fluorescent dye injections demonstrated zebrafish urinary bladder function, including urine storage and intermittent micturition, and a urethral orifice separate from the larger anal canal and rectum. Our findings reveal homology between the urinary tracts of zebrafish and humans, and offer the former as a model system to study disease.

Reelin is required for class-specific retinogeniculate targeting.

Development of visual system circuitry requires the formation of precise synaptic connections between neurons in the retina and brain. For example, axons from retinal ganglion cells (RGCs) form synapses onto neurons within subnuclei of the lateral geniculate nucleus (LGN) [i.e., the dorsal LGN (dLGN), ventral LGN (vLGN), and intergeniculate leaflet (IGL)]. Distinct classes of RGCs project to these subnuclei: the dLGN is innervated by image-forming RGCs, whereas the vLGN and IGL are innervated by non-image-forming RGCs. To explore potential mechanisms regulating class-specific LGN targeting, we sought to identify differentially expressed targeting molecules in these LGN subnuclei. One candidate targeting molecule enriched in the vLGN and IGL during retinogeniculate circuit formation was the extracellular matrix molecule reelin. Anterograde labeling of RGC axons in mutant mice lacking functional reelin (reln(rl/rl)) revealed reduced patterns of vLGN and IGL innervation and misrouted RGC axons in adjacent non-retino-recipient thalamic nuclei. Using genetic reporter mice, we further demonstrated that mistargeted axons were from non-image-forming, intrinsically photosensitive RGCs (ipRGCs). In contrast to mistargeted ipRGC axons, axons arising from image-forming RGCs and layer VI cortical neurons correctly targeted the dLGN in reln(rl/rl) mutants. Together, these data reveal that reelin is essential for the targeting of LGN subnuclei by functionally distinct classes of RGCs.

Outcomes of Ureteroscopic Stone Treatment in Patients With Spinal Cord Injury.

OBJECTIVE: To evaluate the association of clinical factors on outcomes in patients with spinal cord injury (SCI) undergoing ureteroscopy. Immobility, recurrent urinary tract infection, and lower urinary tract dysfunction contribute to renal stone formation in patients with SCI. Ureteroscopy is a commonly utilized treatment modality; however, surgical complication rates and outcomes have been poorly defined. Evidence guiding safe and effective treatment of stones in this cohort remains scarce. METHODS: Records were retrospectively reviewed for patients with SCI who underwent ureteroscopy for kidney stones from 1996 to 2014 at a single institution. Multivariate relationships were evaluated using a general estimating equation model. RESULTS: Forty-six patients with SCI underwent a total of 95 ureteroscopic procedures. After treatment, stone-free rate was 17% and 20% with <2-mm fragments. The complication rate was 21%. On multivariate analysis, SCI in cervical (C) levels was associated with higher risk of complications (C3: odds ratio [OR] 3.83, 95% confidence interval [CI] 2.17-6.98; C6: OR 3.83, 95% CI 1.08-13.53). American Spinal Injury Association Scale A classification was associated with a lower probability of stone-free status (OR 0.16, 95% CI 0.03-0.82). Patients averaged 2.2 procedures yet more procedures were associated with lower stone-free status (OR 0.83, 95% CI 0.03-0.32). Chronic obstructive pulmonary disease and bladder management modality were not associated with stone-free status or complications. CONCLUSION: In patients with SCI, higher injury level and complete SCI were associated with worse stone clearance and more complications. Stone-free rate was 17%. Overall, flexible ureteroscopy is a relatively safe procedure in this population. Alternative strategies should be considered after failed ureteroscopy.

Improving Resident and Nurse Communication Practices: Results of a Collaborative Culture Initiative.

INTRODUCTION: Paging is a critical modality for urgent hospital communication. We sought to improve overnight nurse paging practices to reduce noncritical pages, improve resident sleep practices and create a team approach to patient care between residents and overnight nursing staff. METHODS: Residents, overnight urology nurses and a communications liaison met during 2 overnight sessions in October 2014 to develop a training curriculum for overnight paging, which consisted of a paging protocol based on page urgency, and batching nonurgent communication into a cluster page. Overnight (11 p.m. to 7 a.m.) pages per night were assessed from March 2014 to March 2015. Nurses and residents categorized page messages for perceived urgency. Pre-training and post-training surveys examined physician-nurse opinion after collaboration. RESULTS: Before training the nurses and residents had variable agreement across all urgency categories (Cohen's kappa=0.25 indicating poor agreement, sample size 132 pages). On trained floors average nightly pages decreased from 2.6 during training to 1.6 after training (November to January, Mann-Whitney p=0.007). This reduction was stable 5 months after training (1.8 pages per night, p=0.994 compared to after training). There was also a paging decrease on untrained floors (7.9 from 9.8 pages per night, p=0.005) but the decrease was lost at 5 months (6.29 pages per night, p=0.0493). Paging frequency from trained floors was proportionally lower (50% reduction) than from untrained floors (29% reduction). The post-training survey demonstrated that new paging practices improved overnight communication, physician response and mutual respect. CONCLUSIONS: This nurse-physician training collaborative produced a lasting reduction in overnight pages, an improved resident response to urgent pages and an enhanced culture of mutual respect.

Determining Resident Sleep During and After Call With Commercial Sleep Monitoring Devices.

OBJECTIVE: To demonstrate that commercial activity monitoring devices (CAMDs) are practical for monitoring resident sleep while on call. Studies that have directly monitored resident sleep are limited, likely owing to both cost and difficulty in study interpretation. The advent of wearable CAMDs that estimate sleep presents the opportunity to more readily evaluate resident sleep in physically active settings and "home call," a coverage arrangement familiar to urology programs. METHODS: Twelve urology residents were outfitted with Fitbit Flex devices during "home call" for a total of 57 (out of 64, or 89%) call or post-call night pairs. Residents were surveyed with the Stanford Sleepiness Scale (SSS), a single-question alertness survey. Time in bed (TIB) was "time to bed" to "rise for day." Fitbit accelerometers register activity as follows: (1) not moving; (2) minimal movement or restless; or (3) above threshold for accelerometer to register steps. Total sleep time (TST) was the number of minutes in level 1 activity during TIB. Sleep efficiency (SE) was defined as TST divided by TIB. RESULTS: While on call, 10 responding (of 12 available, 83%) residents on average reported TIB as 347 minutes, TST as 165 minutes, and had an SE of 47%. Interestingly, SSS responses did not correlate with sleep parameters. Post-call sleep demonstrated increases in TIB, SE, and TST (+23%, +15%, and +44%, respectively) while sleepiness was reduced by 22%. CONCLUSION: We demonstrate that urologic residents can consistently wear CAMDs while on home call. SSS did not correlate with Fitbit-estimated sleep duration. Further study with such devices may enhance sleep deprivation recognition to improve resident sleep.

Extreme sensitivity of adult neurogenesis to low doses of X-irradiation.

Therapeutic irradiation of the brain is associated with a number of adverse effects, including cognitive impairment. Although the pathogenesis of radiation-induced cognitive injury is unknown, it may involve loss of neural precursor cells from the subgranular zone (SGZ) of the hippocampal dentate gyrus and alterations in new cell production (neurogenesis). Young adult male C57BL mice received whole brain irradiation, and 6-48 h later, hippocampal tissue was assessed using immunohistochemistry for detection of apoptosis and numbers of proliferating cells and immature neurons. Apoptosis peaked 12 h after irradiation, and its extent was dose dependent. Forty-eight h after irradiation, proliferating SGZ cells were reduced by 93-96%; immature neurons were decreased from 40 to 60% in a dose-dependent fashion. To determine whether acute cell sensitivity translated into long-term changes, we quantified neurogenesis 2 months after irradiation with 0, 2, 5, or 10 Gy. Multiple injections of BrdUrd were given to label proliferating cells, and 3 weeks later, confocal microscopy was used to determine the percentage of BrdUrd-labeled cells that showed mature cell phenotypes. The production of new neurons was significantly reduced by X-rays; that change was dose dependent. In contrast, there were no apparent effects on the production of new astrocytes or oligodendrocytes. Measures of activated microglia indicated that changes in neurogenesis were associated with a significant inflammatory response. Given the known effects of radiation on cognitive function and the relationship between hippocampal neurogenesis and associated memory formation, our data suggest that precursor cell radiation response and altered neurogenesis may play a contributory if not causative role in radiation-induced cognitive impairment.

Head circumference in young children with autism: the impact of different head circumference charts.

The hypothesis that the presence of macrocephaly might vary with the specific growth chart used was tested by using the Nellahus, CDC, and recent Rollins et al revision head circumference charts to plot the head circumferences of 253 children with neurodevelopmental disorders and with ages between 12 to 36 months; of these children, 59 had a diagnosis of autism spectrum disorder. The CDC and Rollins et al head circumference charts identified more cases of macrocephaly and fewer cases of microcephaly than did the older Nellhaus chart but did not significantly differ in their identification of macrocephaly in children with autism.

The role of Gß5 in vision.

Recent advances in our understanding of R7RGS proteins have benefited from studies involving the fifth member of the Gß family (Gß5) that is found throughout the visual system. Unlike conventional Gßsthat form dimers with Gγ, Gß5 partners with R7RGS proteins, which contain the G-protein gamma-like (GGL) domain, to act as a GTPase accelerating protein (GAP) complex on certain Gα subunits. Recent studies in the retina underscore the necessity of Gß5 for normal recovery in photoreceptors and light responses in ON-bipolar cells. Gß5 may also be important for the generation and propagation of spontaneous retinal waves in retina and proper synapse formation in lateral geniculate nucleus (LGN). Here, we review these findings and discuss future investigative directions concerning Gß5's function in vision.

Alterations in hippocampal neurogenesis following traumatic brain injury in mice.

Clinical and experimental data show that traumatic brain injury (TBI)-induced cognitive changes are often manifest as deficits in hippocampal-dependent functions of spatial information processing. The underlying mechanisms for these effects have remained elusive, although recent studies have suggested that the changes in neuronal precursor cells in the dentate subgranular zone (SGZ) of the hippocampus might be involved. Here, we assessed the effects of unilateral controlled cortical impact on neurogenic cell populations in the SGZ in 2-month-old male C57BL6 mice by quantifying numbers of dying cells (TUNEL), proliferating cells (Ki-67) and immature neurons (Doublecortin, Dcx) up to 14 days after TBI. Dying cells were seen 6 h after injury, peaked at 24 h and returned to control levels at 14 days. Proliferating cells were decreased on the ipsilateral and contralateral sides at all the time points studied except 48 h after injury when a transient increase was seen. Simultaneously, immature neurons were reduced up to 84% relative to controls on the ipsilateral side. In the first week post-TBI, reduced numbers of Dcx-positive cells were also seen in the contralateral side; a return to control levels occurred at 14 days. To determine if these changes translated into longer-term effects, BrdU was administered 1 week post-injury and 3 weeks later the phenotypes of the newly born cells were assessed. TBI induced decreases in the numbers of BrdU-positive cells and new neurons (BrdU/NeuN) on the ipsilateral side without apparent changes on the contralateral side, whereas astrocytes (BrdU/GFAP) were increased on the ipsilateral side and activated microglia (BrdU/CD68) were increased on both ipsi- and contralateral sides. No differences were noted in oligodendrocytes (BrdU/NG2). Taken together, these data demonstrate that TBI alters both neurogenesis and gliogenesis. Such alterations may play a contributory role in TBI-induced cognitive impairment.

Radiation-induced impairment of hippocampal neurogenesis is associated with cognitive deficits in young mice.

Advances in the management of pediatric brain tumors have increased survival rates in children, but their quality of life is impaired due to cognitive deficits that arise from irradiation. The pathogenesis of these deficits remains unknown, but may involve reduced neurogenesis within the hippocampus. To determine the acute radiosensitivity of the dentate subgranular zone (SGZ), 21-day-old C57BL/J6 male mice received whole brain irradiation (2-10 Gy), and 48 h later, tissue was assessed using immunohistochemistry. Proliferating SGZ cells and their progeny, immature neurons, were decreased in a dose-dependent fashion. To determine if acute changes translated into long-term alterations in neurogenesis, mice were given a single dose of 5 Gy, and 1 or 3 months later, proliferating cells were labeled with 5-bromo-2'-deoxyuridine (BrdU). Confocal microscopy was used to determine the percentage of BrdU-labeled cells that showed mature cell phenotypes. X-rays significantly reduced the production of new neurons at both time points, while glial components showed no change or small increases. Measures of activated microglia and infiltrating, peripheral monocytes indicated that reduced neurogenesis was associated with a chronic inflammatory response. Three months after irradiation, changes in neurogenesis were associated with spatial memory retention deficits determined using the Morris water maze. Behavioral training and testing increased the numbers of immature neurons, most prominently in irradiated animals. These data provide evidence that irradiation of young animals induces a long-term impairment of SGZ neurogenesis that is associated with hippocampal-dependent memory deficits.

Long-term persistence of infection in chimpanzees inoculated with an infectious hepatitis C virus clone is associated with a decrease in the viral amino acid substitution rate and low levels of heterogeneity.

Two chimpanzees, 1535 and 1536, became persistently infected following inoculation with RNA transcripts from cDNA clones of hepatitis C virus (HCV). Analysis of the HCV genomes from both animals showed an accumulation of amino acid substitutions over time. The appearance of substitutions in the envelope genes was associated with increased antienvelope antibody titers. However, extensive mutations were not incorporated into hypervariable region 1 (HVR1). A comparison of the nonsynonymous substitution rate/synonymous substitution rate was made at various time points to analyze selective pressure. The highest level of selective pressure occurred during the acute phase and decreased as the infection continued. The nonsynonymous substitution rate was initially higher than the synonymous substitution rate but decreased over time from 3.3 x 10(-3) (chimpanzee 1535) and 3.2 x 10(-3) (chimpanzee 1536) substitutions/site/year at week 26 to 1.4 x 10(-3) (chimpanzee 1535) and 1.7 x 10(-3) (chimpanzee 1536) at week 216, while the synonymous substitution rate remained steady at approximately 1 x 10(-3) substitutions/site/year. Analysis of PCR products using single-stranded conformational polymorphism indicated a low level of heterogeneity in the viral genome. The results of these studies confirm that the persistence of infection is not solely due to changes in HVR1 or heterogeneity and that the majority of variants observed in natural infections could not arise simply through mutation during the time period most humans and chimpanzees are observed. These data also indicate that immune pressure and selection continue throughout the chronic phase.