Impact of pelvic immobilization techniques on the outcomes of primary and secondary closures of classic bladder exstrophy

INTRODUCTION

A potential determinant of successful bladder closures in patients with classic bladder exstrophy (CBE) is the postoperative pelvic immobilization technique. This study investigates the success rates of primary and secondary bladder closures based on various immobilization techniques from a high-volume exstrophy center.

METHODS

A prospectively maintained institutional exstrophy-epispadias complex database of 1336 patients was reviewed for patients with CBE who have undergone primary or secondary closures between 1975 and 2018 and subsequently had a known method of pelvic immobilization. Patients were divided into two groups: primary and secondary closures. Associations between closure outcomes and immobilization techniques were determined.

RESULTS

A total of 476 patients with primary closures and 101 patients with secondary closures met the inclusion criteria. In total, 343 (72.1%) primary closures were successful. As shown in the table, the success rates of primary closures were highest in patients immobilized with modified Buck's and Bryant's traction (95.0% and 79.3%, respectively) and lowest in those with spica cast (49.6%). A propensity score-adjusted logistic regression (adjusting for osteotomy status, period of closure, location of closure, and closure type) revealed that modified Buck's traction had a 5.60 (95% confidence interval 1.74-23.1, p = 0.008) greater odds of success compared to spica casting during the primary closure. For the secondary closure group, there were 92 (92.1%) successful secondary closures. Success rates were highest in modified Buck's traction (97.3%) and lowest with spica casting (66.7%).

DISCUSSION

This study confirms previous findings of better outcomes when patients are immobilized with external fixation and Buck's traction after adjusting for potential confounding factors. Immobilization with modified Buck's or Bryant's traction yielded significantly higher primary closure success rates when compared to spica casting. It is the authors' belief that despite a longer hospital length of stay, external fixation with Buck's traction provides the best chance of a successful closure and, thus, a financially responsible method to care for these children in the postoperative period.

CONCLUSIONS

Success rates for primary closures were highest when using modified Buck's traction with external fixation and lowest for spica casts. Similarly, for secondary closures, the best outcomes were achieved using modified Buck's traction with external fixation and the lowest success rates were associated with spica casts.

Modified Young-Dees-Leadbetter bladder neck reconstruction: new concepts about old ideas

INTRODUCTION

The modern Young-Dees-Leadbetter bladder neck reconstruction is a procedure that has evolved during the past 82 years. During this time, the modifications and contributions of several urologic surgeons have improved the procedure and ultimate patient outcomes. We review the evolution and describe in detail our version of the Young-Dees-Leadbetter bladder neck reconstruction procedure.

TECHNICAL CONSIDERATIONS

Optimally, patients should have a minimal bladder capacity of 85 mL and be mature enough to participate in a postoperative voiding program. Adequate radical exposure of the lateral aspects of the bladder and bladder neck are important. Cephalotrigonal or cross-trigonal ureteral reimplantation is typically performed to mobilize the ureters in relation to the proposed bladder neck and correct reflux. A mucosal template 15 mm wide by 30 mm long is created that will serve as the reconstituted posterior urethra and bladder neck. Triangular lateral bladder mucosal wedges are marked and demucosalized. The neourethra is closed over an 8F Firlit tube. The demucosalized flaps are brought over the urethra sequentially in a "vest-over-pants" fashion with the final layer consisting of suspension sutures. Finally, ureteral stents and a suprapubic tube are used, but no urethral catheter is left in place.

CONCLUSIONS

The modern Young-Dees-Leadbetter bladder neck reconstruction is the result of the contributions of various urologic surgeons during 82 years. When patients are appropriately selected, it is an effective method of lower urinary tract reconstruction in cases of congenital urinary incontinence.

The end of the beginning for pluripotent stem cells

Pluripotent stem cells can be expanded seemingly indefinitely in culture, maintain a normal karyotype and have the potential to generate any cell type in the body. As such they represent an incredible resource for the repair of diseased or damaged tissues in our bodies. These cells also promise to open a new window into the embryonic development of our species.

Identification of elf1, a beta-spectrin, in early mouse liver development

Beta-spectrins play essential roles in cell-cell interactions and in the maintenance of cell polarity. Our aim was to identify beta-spectrin genes important for the establishment of hepatocyte polarity and differentiation. Using subtractive screening of cDNA libraries from early embryonic mouse livers (post-coital days 10, 11, and 12), we have isolated elf1 (embryonic liver fodrin 1), a differentially expressed beta-spectrin or fodrin (betaSpIIsigmaI). Elf1 encodes a 220-amino acid protein with an NH2 terminal actin-binding domain. In situ hybridization studies demonstrate elf1 expression initially in day 10 embryonic heart tissue, then in day 11-11.5 hepatic tissue. These studies suggest that elf1 may play a role in the emergence of hepatocyte polarity during liver development.

Pharmacodynamic model of the rat estrus cycle in relation to endocrine disruptors

Several strains of laboratory rats have a high background incidence of mammary tumors and develop a persistent, anovulatory estrus condition at about 12 mo of age. The increased tumor incidence is believed to be associated with elevated estradiol (E2) and prolactin during the period of persistent estrus. A pharmacodynamic estrus cycle (PD-EC) model for the Sprague-Dawley rats has been developed in an attempt to analyze the physiological basis of early-onset persistent estrus and to examine the potential sites of interactions in the hypothalamic-pituitary-ovarian axis for endocrine-modulating xenobiotics that accelerate the onset of persistent estrus. This initial estrus cycle model focused solely on cyclical changes in E2 and luteinizing hormone (LH). An LH surge was scheduled when a hypothetical estrus cycle-related protein (EC-RP) under transcriptional control by the E2 receptor reached a critical concentration. In the model, aging-related cumulative hypothalamic E2 exposure impaired the LH surge by reducing the rate of production of the EC-RP. The progressively decreasing intercycle resynthesis rate leads first to longer, variable-length cycles and finally to persistent estrus at about 12 mo of age. This model construct is consistent with early-onset persistent estrus related to neonatal E2 exposures, with acyclicity associated with high-dose E2 exposure in the adult, and with persistent estrus conditions associated with exposures to xenobiotic endocrine modulators that are either weak E2 antagonists or weak E2 agonists. With further development these pharmacodynamic estrus cycle models should be useful in aiding risk assessments for compounds causing mammary-tissue tumors associated with persistent estrus states.

Lactational transfer of volatile chemicals in breast milk

Lactational transfer of chemicals to nursing infants is a concern for occupational physicians when women who are breast-feeding return to the workplace. Some work environments, such as paint shops, have atmospheric contamination from volatile organic chemicals (VOCs). Very little is known about the extent of exposure a nursing infant may receive from the mother's occupational exposure. A physiologically based pharmacokinetic model was developed for a lactating woman to estimate the amount of chemical that a nursing infant ingests for a given nursing schedule and maternal occupational exposure. Human blood/air and milk/air partition coefficients (PCs) were determined for 19 VOCs. Milk/blood PC values were above 3 for carbon tetrachloride, methylchloroform, perchloroethylene, and 1,4-dioxane, while the remaining 16 chemicals had milk/blood PC values of less than 3. Other model parameters, such as solid tissue PC values, metabolic rate constants, blood flow rates, and tissue volumes were taken from the literature and incorporated into the lactation model. In a simulated exposure of a lactating woman to a threshold limit value concentration of an individual chemical, only perchloroethylene, bromochloroethane, and 1,4-dioxane exceeded the U.S. Environmental Protection Agency non-cancer drinking water ingestion rates for children. Very little data exists on the pharmacokinetics of lactational transfer of volatile organics. More data are needed before the significance of the nursing exposure pathway can be adequately ascertained. Physiologically based pharmacokinetic models can play an important role in assessing lactational transfer of chemicals.

Reanalysis of dose-response data from the Iraqi methylmercury poisoning episode

Applying a hockey stick parametric dose-response model to data on late or retarded development in Iraqi children exposed in utero to methylmercury, with mercury (Hg) exposure characterized by the peak Hg concentration in mothers' hair during pregnancy, Cox et al. calculated the "best statistical estimate" of the threshold for health effects as 10 ppm Hg in hair with a 95% range of uncertainty of between 0 and 13.6 ppm. A new application of the hockey stick model to the Iraqi data shows, however, that the statistical upper limit of the threshold based on the hockey stick model could be as high as 255 ppm. Furthermore, the maximum likelihood estimate of the threshold using a different parametric model is virtually zero. These and other analyses demonstrate that threshold estimates based on parametric models exhibit high statistical variability and model dependency, and are highly sensitive to the precise definition of an abnormal response. Consequently, they are not a reliable basis for setting a reference dose (RfD) for methylmercury. Benchmark analyses and statistical analyses useful for deriving NOAELs are also presented. We believe these latter analyses--particularly the benchmark analyses--generally form a sounder basis for determining RfDs than the type of hockey stick analysis presented by Cox et al. However, the acute nature of the exposures, as well as other limitations in the Iraqi data suggest that other data may be more appropriate for determining acceptable human exposures to methylmercury.

Regulated expression of an insulin-responsive glucose transporter (GLUT4) minigene in 3T3-L1 adipocytes and transgenic mice

Preliminary studies showed that up to 7 kb of 5' flanking sequence of the insulin-responsive glucose transporter (GLUT4) gene are insufficient to mediate differentiation-induced reporter gene expression in mouse 3T3-L1 preadipocytes. To locate the regulatory element(s) responsible for this function, a minigene containing the entire GLUT4 gene with substantial 5' and 3' flanking sequence and a short segment of foreign DNA (for transcript identification) was constructed and transfected into mice and 3T3-L1 preadipocytes at relatively low copy number. In transgenic mice the GLUT4 minigene exhibited a pattern of tissue-specific expression similar, but not identical, to that of the endogenous gene. In 3T3-L1 cells expression of minigene mRNA occurred upon differentiation into adipocytes, with kinetics virtually identical to that of endogenous GLUT4 mRNA. In both cultured adipocytes and transgenic mice, the level of expression of the minigene was low relative to that of the endogenous gene. Treatment of minigene-transfected 3T3-L1 adipocytes with 8-bromo-cAMP, which represses transcription of the endogenous GLUT4 gene, also repressed expression of the GLUT4 minigene. However, insulin, which down-regulates transcription of the endogenous GLUT4 gene, failed to normally down-regulate expression of the GLUT4 minigene. These findings indicate that the cis-acting elements required for directing tissue-specific expression (in heart, skeletal muscle, and brown adipose tissue), differentiation-induced activation of transcription, and cAMP-induced repression of transcription are located within the 14-kb GLUT4 minigene. However, the cis elements necessary for maximal tissue-specific expression and for insulin-induced down-regulation of expression are not located in the minigene.

A locus control region adjacent to the human red and green visual pigment genes

Deletion of sequences 5' of the human red and green pigment gene array results in blue cone monochromacy, a disorder in which both red and green cone function are absent. To test whether these sequences are required for transcription of the adjacent visual pigment genes in cone photoreceptors, we produced transgenic mice carrying sequences upstream of the red and green pigment genes fused to a beta-galactosidase reporter. The patterns of transgene expression indicate that the human sequences direct expression to both long and short wave-sensitive cones in the mouse retina and that a region between 3.1 kb and 3.7 kb 5' of the red pigment gene transcription initiation site is essential for expression. Sequences within this region are highly conserved among humans, mice, and cattle, even though the latter two species have only a single visual pigment gene at this locus. These experiments suggest a model in which an interaction between the conserved 5' region and either the red or the green pigment gene promoter determines which of the two genes a given cone expresses.

The Cytobrush effect on Pap smear adequacy

One hundred twenty-four Papanicolaou smears were studied to compare the yield of endocervical cells obtained with the Cytobrush/Ayre spatula method to that of the cotton-tipped applicator/Ayre spatula method. Forty-nine of the 62 Pap smears (79%) obtained with the combination Cytobrush/Ayre spatula method contained endocervical cells, compared to 22 of the 62 smears (35%) obtained with the cotton swab/Ayre spatula method (chi 2 = 24.02, P less than 0.0001). The Cytobrush/Ayre spatula method obtained endocervical cells in 14 of 17 (82.4%) of the patients with stenotic ora, compared to 0 of 12 (0%) patients for the cotton swab/Ayre spatula method (P less than 0.001). The Cytobrush/Ayre spatula method obtained endocervical cells in 8 of 11 (72.7%) postmenopausal patients, compared to 4 of 14 (28.6%) patients for the cotton swab/Ayre spatula method (P = 0.05). Using the cervical Cytobrush for Pap smears increases the recovery rate of endocervical cells, which may improve the detection of cervical dysplasia in the patient population as a whole, in postmenopausal women, and in women with stenotic cervical ora.

Unusual topography of bovine rhodopsin promoter-lacZ fusion gene expression in transgenic mouse retinas

To define the cis-acting DNA elements required for rhodopsin expression, we generated lines of transgenic mice carrying sequences upstream of the bovine rhodopsin gene fused to the E. coli beta-galactosidase gene (lacZ). Upstream sequences extending from -2174 to +70 bp, from -734 to +70 bp, and from -222 to +70 bp direct photoreceptor-specific expression. All three -2174 lines demonstrate a superior-temporal to inferior-nasal gradient of expression across the retina, whereas lines carrying the shorter constructs demonstrate either spatially continuous expression across the retina, discrete clusters of expression, or both. As a complementary approach to defining regulatory elements, we compared DNA sequences 5' of the murine, bovine, and human rhodopsin genes. Significant homology between all three species was found just upstream of the transcription start site and at approximately 1.5 kb upstream.

Conserved chromosomal positions of dual domains of the ets protooncogene in cats, mice, and humans

The mammalian protooncogene homologue of the avian v-ets sequence from the E26 retrovirus consists of two sequentially distinct domains located on different chromosomes. Using somatic cell hybrid panels, we have mapped the mammalian homologue of the 5' v-ets-domain to chromosome 11 (ETS1) in man, to chromosome 9 (Ets-1) in mouse, and to chromosome D1 (ETS1) in the domestic cat. The mammalian homologue of the 3' v-ets domain was similarly mapped to human chromosome 21 (ETS2), to mouse chromosome 16 (Ets-2), and to feline chromosome C2 (ETS2). Both protooncogenes fell in syntenic groups of homologous linked loci that were conserved among the three species. The occurrence of two distinct functional protooncogenes and their conservation of linkage positions in the three mammalian orders indicate that these two genes have been separate since before the evolutionary divergence of mammals.

Morphologic and neurochemical studies of embryonic brain development in murine trisomy 16

Telencephalic and diencephalic/brainstem regions from embryonic trisomy-16 mice (Ts16) between gestational days 15-18 were analyzed for alterations of morphologic and neurochemical parameters and compared to phenotypically normal littermates. Mean trisomic wet weights from both regions were significantly diminished (greater than 20%) and total protein content was reduced. Ratios of the thickness of the ventricular (germinal) zone to the thickness of the whole cortex were increased, suggesting a delay in neuronal differentiation. Pre- and postsynaptic markers for GABAergic, cholinergic, catecholaminergic and serotonergic transmitter systems were compared. A significant impairment of the trisomic brain catecholaminergic and serotonergic system development was observed, based upon regional reductions in norepinephrine, dopamine and serotonin content. Choline acetyltransferase activity in the diencephalon/brainstem was reduced by 21-26% in contrast to normal levels within the cerebral hemispheres. Presynaptic GABAergic markers were not affected in the Ts16 embryos. It is concluded that although a genetic imbalance involving chromosome 16 in the mouse embryo produces a delay in neurogenesis, it has a more selective effect on the catecholaminergic, serotonergic and cholinergic systems than on GABAergic neurons.

Immunoreactivity of the two common allozymes of murine glucosephosphate isomerase

There are two common electrophoretic variants (allozymes) of murine glucosephosphate isomerase (GPI). In order to develop immunocytochemical procedures that are allozyme-specific, the two variants (GPI-1A and GPI-1B) were purified from skeletal muscle of several mouse strains and used as antigens for the elicitation of antibodies. The allozymes were purified to a specific activity of 800 units/mg by substrate elution from cellulose phosphate. When the purified allozymes were presented as antigens to goats, rabbits, and mice (both syngeneically and allogeneically), the goats and rabbits produced high titers of anti-GPI antibody, but no humoral antibody was detected in the mice, as determined by radioimmunoassays. Antisera specific for the GPI-1B variant were enriched by absorbing selected sera with GPI-1A conjugated to Sepharose 4B. No antisera specific for GPI-1A were detected following the immunizations. The specificity of the anti-GPI-1B antisera provides a unique opportunity for the development of immunocytochemical procedures for studying the distribution fo this allozyme in chimeric mouse tissues.

Age-related pigmentation changes in the coats of allophenic mice

Hair pigmentation and patterns of pigmentation change with age in the coats of BALB/cByJ in equilibrium C57BL/6J allophenic mice. These changes are particularly evident on the dorsum where there is an increase in the proportion of white areas at the expense of agouti and black areas. The most plausible explanation for these changes is that they represent a continuous selection for one of the two genotypes of cells from which the melanoblasts and hair follicles of these animals are derived.

An immunofluorescence procedure for the tissue localization of glucosephosphate isomerase

Anti-glucosephosphate isomerase antibodies have been used to reveal the presence of the glycolytic and gluconeogenic enzyme, glucosephosphate isomerase (GPI) in mouse tissues by an indirect immunofluorescence technique. The enzyme was localized in 6-micron sections from tissues embedded in paraffin. GPI was observed in the sarcoplasm of skeletal muscle, all hepatocytes of the liver, and in the granulosa cells and oocytes of growing ovarian follicles. The immunofluorescence procedure circumvents the problems associated with the conventional localization of GPI by histochemistry and appears to be a more sensitive procedure for the detection of low concentrations of GPI, as demonstrated by the staining of the ovarian follicles.

Immunofluorescence and histochemical localization of glucosephosphate isomerase in neural tissues

The distribution of glucosephosphate isomerase (GPI, D-glucose-6-phosphate ketol isomerase) in mouse nervous tissue has been determined at the light microscopic level by immunofluorescence and histochemical procedures. The fluorescence procedure, which utilizes anti-GPI antibodies, detected lower levels of GPI than the histochemical procedure, which relies upon the catalytic activity of the enzyme. The distribution of GPI in nervous tissue is very similar to that of hexokinase. High levels of GPI were found in the Purkinje cells, the molecular layer, and the glomeruli of the granular layer in the cerebellar cortex; the pontine nuclei and the inferior olivary nuclei of the pons and medulla; the neurons of the thalamus and hypothalamus; the pyramidal cells, the dentate nuclei, and Ammons' horn of the cerebral cortex; the ventral horn cells of the spinal cord; and ventricular cells, choroid plexus cells, and the leptomeninges. The neuropil throughout the central nervous system (CNS) stained uniformly with moderately high levels of GPI. No GPI was observed in the myelin sheaths of the CNS.