Exploratory factor analysis of the Illness Intrusiveness Rating Scale for parents of children with atypical genital appearance due to differences of sex development (DSD)

OBJECTIVE

Illness intrusiveness refers to the subjective cognitive appraisal of a chronic health condition interfering in daily, valued activities and may be highly relevant for parents of children with atypical genital appearance due to differences of sex development (DSD). However, a measure of illness intrusiveness has not been validated for this population. The current study aimed to evaluate the factor structure of the Illness Intrusiveness Scale for Parents (IIS-P) and examine convergent validity.

METHODS

Participants included 102 parents (Mage = 33.39 years, SD = 6.48; 58% mothers) of 65 children (<2 years old) diagnosed with DSD participating in a larger, longitudinal study. Parents completed the IIS-P as well as self-report measures of stigma, and anxious and depressive symptoms. An exploratory factor analysis (EFA) was conducted.

RESULTS

EFA results supported a 1-factor intrusiveness solution (α = .93), as well as a 2-factor solution measuring intrusiveness on daily living (α = .92) and community connectedness (α = .85). The 1-factor solution and both factors of the 2-factor solution demonstrated significant convergent validity with stigma as well as anxious and depressive symptoms.

CONCLUSIONS

Support emerged for both 1- and 2-factor solutions of the IIS-P in parents of children with DSD. The decision to evaluate illness intrusiveness as a total score or to examine the subscales of daily living and community connectedness should be tailored to the unique aims of researchers and clinicians. Future research should conduct a confirmatory factor analysis with both 1- and 2-factor models with larger, more diverse samples of caregivers.

Parental Uncertainty Scale Factor Structure in Pediatric DSD With Ambiguous Genitalia

OBJECTIVE

Illness uncertainty is a salient experience for caregivers of children with disorders/differences of sex development (DSD) presenting with ambiguous genitalia; however, no validated measure of illness uncertainty exists for this unique population. Thus, the current study aimed to preliminarily identify the factor structure of the Parental Perception of Uncertainty Scale (PPUS) in caregivers of children with DSD presenting with ambiguous genitalia and examine the convergent validity of the PPUS.

METHODS

Participants included 115 caregivers (Mage = 32.12 years, SD = 6.54; 57% mothers) of children (<2-year-olds) diagnosed with DSD participating in a larger, longitudinal study. Caregivers completed the PPUS as well as self-report measures of anxious, depressive, and posttraumatic stress symptoms. An exploratory factor analysis was conducted.

RESULTS

Exploratory factor analysis results indicated that a 23-item 1-factor solution was the most parsimonious and theoretically sound factor structure (α = 0.92). Convergent validity analyses demonstrated further support for the use of the 23-item 1-factor solution over the original PPUS factor structure.

CONCLUSION

These results demonstrate the preliminary clinical and research utility of the PPUS with caregivers of children with DSD presenting with ambiguous genitalia. The PPUS may benefit from further refinement through qualitative research and item adaptation to capture uncertainties unique to DSD presenting with ambiguous genitalia. In addition, future research should replicate the proposed factor structure using confirmatory factor analysis with a separate, larger sample of caregivers of children with DSD to confirm the factor structure.

Decisional Regret Among Caregivers of Infants with Differences of Sex Development Reared as Male

OBJECTIVE

Differences of sex development (DSD) are congenital conditions in which individuals are discordant in their chromosomal, phenotypic, and/or gonadal sex. Treatment of DSD can involve surgical intervention to external genitalia to make anatomy seem male-typical (i.e., male genitoplasty). Caregiver-perceived decisional regret regarding young boys with DSD was explored quantitatively and qualitatively.

METHOD

Participants (N = 39) were caregivers of infants (N = 23) diagnosed with DSD (mean age = 8.9 months, standard deviation = 5.9 months) reared male participating in a longitudinal investigation of psychosocial outcomes. Qualitative data were collected at 6 to 12 months after baseline enrollment to evaluate caregiver decision-making corresponding to levels of regret concerning their child's treatment. All but one infant received genital surgery before caregiver reporting on their decisional regret. Quantitative exploratory analyses evaluated longitudinal predictors of decisional regret at 6 to 12 months.

RESULTS

When completing a write-in item inquiring about decision-making and potential regret, most caregivers (n = 16, 76%) reported that their child's genital surgery was their first medical decision. Two caregivers referenced gender assignment as a decision point. One-third of caregivers reported some level of decisional regret (33%), with 67% reporting no regret. No hypothesized predictors of decisional regret were statistically significant.

CONCLUSION

Many caregivers of infants with DSD reared male view genital surgery as a first health care decision. Approximately one-third of caregivers reported some level of decisional regret. Further research is warranted to explore long-term decisional regret; it will be particularly important to investigate the decisional regret of patients with DSD.

Decisional regret about surgical and non-surgical issues after genitoplasty among caregivers of female infants with CAH

INTRODUCTION

Caregivers of female infants with congenital adrenal hyperplasia (CAH) often confront complex medical decision-making (e.g., early feminizing genitoplasty).

OBJECTIVE

This study aimed to evaluate the relevant medical decisions and subsequent decisional regret of caregivers following their child's genitoplasty.

STUDY DESIGN

Caregivers (N = 55) were recruited from multidisciplinary treatment programs for participation in a longitudinal study. Qualitative data was collected at 6-12 months following feminizing genitoplasty to evaluate caregiver-reported decision points across their child's treatment. Quantitative exploratory analysis evaluated pre-operative predictors of subsequent decisional regret.

DISCUSSION

When prompted about their decision-making and potential regret, most caregivers (n = 32, 80%) reported that their daughter's genital surgery was their primary medical decision. Specific themes regarding genital surgery included the timing and type of surgery. Most caregivers reported no decisional regret (62%), with 38% reporting some level of regret. Greater pre-operative illness uncertainty predicted heightened decisional regret at follow-up, p = .001.

CONCLUSION

Two-thirds of caregivers of female infants with CAH reported not regretting their decision-making. Nevertheless, over one-third of caregivers reported some level of regret, suggesting the need for improvements in shared decision-making processes. Many, but not all, families reported that this regret was related to surgical decision-making. Reducing caregiver illness uncertainty (e.g., providing clear information to families) may increase their satisfaction with decision-making. Further research is needed to determine how the evolving care practices surrounding early genitoplasty will impact families.

Factor Analysis of the Stigma Scale-Parent Version in Pediatric Disorders/Differences of Sex Development

Stigma is a salient experience for both caregivers/parents and individuals with Disorders/Differences of Sex Development (DSD) as evidenced through qualitative and preliminary quantitative reports. However, few validated measures of associative stigma (i.e., vicarious stigma experienced through close association with someone who is socially stigmatized) for parents of children with DSD exist. The present study aims to (1) determine the factor structure of the adapted Stigma Scale - Parent, and (2) examine convergent validity of the factor structure with measures of parent psychosocial adjustment. Confirmatory factor analytic results revealed two factors: a parent-focused factor and a child-focused factor. The parent-focused factor demonstrated convergent validity with parent adjustment measures, but the child-focused factor did not. Together, these results indicate that parent-focused and child-focused stigma are distinct factors, with parent-focused associative stigma being related to parent adjustment following DSD diagnosis. Future research should further refine this measure to determine predictive validity and clinical value.

Post-operative complications following masculinizing genitoplasty in moderate to severe genital atypia: results from a multicenter, observational prospective cohort study

INTRODUCTION

Differences of sex development (DSD) are congenital conditions in which there is atypical chromosomal, gonadal and/or phenotypic sex. A phenotype of severe genital atypia in patients raised as male is a relatively rare occurrence and standards for management are lacking. Decision making for early surgical planning in these rare cases includes, but is not limited to, degree of atypia, location of testes, and presence of Mϋllerian remnants. In this study we describe surgical approaches and short-term outcomes for masculinizing genitoplasty in moderate to severe genital atypia in young patients raised male, for whom parents opted for early surgery.

METHODS

This NIH-sponsored study is an ongoing, observational, multicenter investigation assessing medical, surgical and psychological outcomes in children and their parents affected by atypical genitalia due to DSD. Participants were prospectively enrolled from 12 children's hospitals across the United States that specialize in DSD care. Criteria for child enrollment were a Quigley score of 3-6 in those with a 46, XY or 45,X/46, XY chromosome complement, age <3 years with no previous genitoplasty; patients were included independent of whether genitoplasty was performed. Cosmesis was graded according to a 4-point Likert scale and complications per the Clavian-Dindo classification.

RESULTS

Of the 31 participants, 30 underwent hypospadias repair and 1 patient did not undergo a genitoplasty procedure. The majority of participants (22) received a staged hypospadias repair. Seventeen complications were identified in 12 of the 31 children (41%) at 12 months of follow up. Glans dehiscence and urethrocutaneous fistula were the most common complications. Orchiopexy was performed in 14 (44%) and streak gonads were removed in 4 (13%) participants. Both parents and surgeons reported improved cosmesis after surgery when compared to baseline.

CONCLUSION

Genitoplasty was chosen by parents for the majority of children eligible for study. No single surgical approach for masculinizing moderate to severe genital ambiguity in young patients with 46, XY or 45,X/46, XY DSD was adopted by all surgeons. Complications occurred in 41% of those who underwent genitoplasty for severe hypospadias. Overall, appearance of the genitals, as determined by parents and surgeons, improved following genitoplasty. Outcomes of early genitoplasty are needed to guide families when making decisions about such procedures for their young children.

Distress Trajectories for Parents of Children With DSD: A Growth Mixture Model

OBJECTIVE

This study identifies trajectories of parent depressive symptoms after having a child born with genital atypia due to a disorder/difference of sex development (DSD) or congenital adrenal hyperplasia (CAH) and across the first year postgenitoplasty (for parents who opted for surgery) or postbaseline (for parents who elected against surgery for their child). Hypotheses for four trajectory classes were guided by parent distress patterns previously identified among other medical conditions.

METHODS

Participants included 70 mothers and 50 fathers of 71 children diagnosed with a DSD or CAH with reported moderate to high genital atypia. Parents were recruited from 11 US DSD specialty clinics within 2 years of the child's birth and prior to genitoplasty. A growth mixture model (GMM) was conducted to identify classes of parent depressive symptoms over time.

RESULTS

The best fitting model was a five-class linear GMM with freely estimated intercept variance. The classes identified were termed "Resilient," "Recovery," "Chronic," "Escalating," and "Elevated Partial Recovery." Four classes have previously been identified for other pediatric illnesses; however, a fifth class was also identified. The majority of parents were classified in the "Resilient" class (67.6%).

CONCLUSIONS

This study provides new knowledge about the trajectories of depressive symptoms for parents of children with DSD. Future studies are needed to identify developmental, medical, or familial predictors of these trajectories.

Uncertainty and Posttraumatic Stress: Differences Between Mothers and Fathers of Infants with Disorders of Sex Development

Parents of children with disorders of sex development (DSD) report significant psychological distress, including posttraumatic stress symptoms (PTSS), with mothers consistently reporting higher rates of psychological distress than fathers. However, psychological factors contributing to PTSS in both parents are not well understood. The present study sought to fill this gap in knowledge by examining PTSS and illness uncertainty, a known predictor of psychological distress, in parents of children recently diagnosed with DSD. Participants were 52 mothers (M_age = 32.55 years, SD = 5.08) and 41 fathers (M_age = 35.53 years, SD = 6.78) of 53 infants (M_age = 9.09 months, SD = 6.19) with DSD and associated atypical genital development. Participants were recruited as part of a larger, multisite study assessing parents' psychosocial response to their child's diagnosis of DSD. Parents completed measures of illness uncertainty and PTSS. Mothers reported significantly greater levels of PTSS, but not illness uncertainty, than fathers, and were more likely than fathers to report clinical levels of PTSS (21.2% compared to 7.3%). Hierarchical regression revealed that parent sex, undiagnosed or unclassified DSD status, and illness uncertainty were each associated with PTSS. The overall model accounted for 23.5% of the variance associated with PTSS. Interventions targeting illness uncertainty may be beneficial for parents of children with newly diagnosed DSD.

Baseline Characteristics of Infants With Atypical Genital Development: Phenotypes, Diagnoses, and Sex of Rearing

Purpose

Little is known about the phenotypes, diagnoses, and sex of rearing of infants with atypical genital development in the United States. As part of a multicenter study of these infants, we have provided a baseline report from US difference/disorder of sex development clinics describing the diagnoses, anatomic features, and sex of rearing. We also determined whether consensus guidelines are followed for sex designation in the United States.

Methods

Eligible participants had moderate-to-severe genital atypia, were aged <3 years, and had not undergone previous genitoplasty. Karyotype, genetic diagnosis, difference/disorder of sex development etiology, family history, and sex of rearing were collected. Standardized examinations were performed.

Results

Of 92 subjects, the karyotypes were 46,XX for 57%, 46,XY for 34%, and sex chromosome abnormality for 9%. The median age at the baseline evaluation was 8.8 months. Most 46,XX subjects (91%) had congenital adrenal hyperplasia (CAH) and most 46,XY subjects (65%) did not have a known diagnosis. Two individuals with CAH underwent a change in sex of rearing from male to female within 2 weeks of birth. The presence of a uterus and shorter phallic length were associated with female sex of rearing. The most common karyotype and diagnosis was 46,XX with CAH, followed by 46,XY with an unknown diagnosis. Phenotypically, atypical genitalia have been most commonly characterized by abnormal labioscrotal tissue, phallic length, and urethral meatus location.

Conclusions

An increased phallic length was positively associated with rearing male. Among the US centers studied, sex designation followed the Consensus Statement recommendations. Further study is needed to determine whether this results in patient satisfaction.

Preliminary report: Surgical outcomes following genitoplasty in children with moderate to severe genital atypia

INTRODUCTION

Prior studies of outcomes following genitoplasty have reported high rates of surgical complications among children with atypical genitalia. Few studies have prospectively assessed outcomes after contemporary surgical approaches.

OBJECTIVE

The current study reported the occurrence of early postoperative complications and of cosmetic outcomes (as rated by surgeons and parents) at 12 months following contemporary genitoplasty procedures in children born with atypical genitalia.

STUDY DESIGN

This 11-site, prospective study included children aged ≤2 years, with Prader 3-5 or Quigley 3-6 external genitalia, with no prior genitoplasty and non-urogenital malformations at the time of enrollment. Genital appearance was rated on a 4-point Likert scale. Paired t-tests evaluated differences in cosmesis ratings.

RESULTS

Out of 27 children, 10 were 46,XY patients with the following diagnoses: gonadal dysgenesis, PAIS or testosterone biosynthetic defect, severe hypospadias and microphallus, who were reared male. Sixteen 46,XX congenital adrenal hyperplasia patients were reared female and one child with sex chromosome mosaicism was reared male. Eleven children had masculinizing genitoplasty for penoscrotal or perineal hypospadias (one-stage, three; two-stage, eight). Among one-stage surgeries, one child had meatal stenosis (minor) and one developed both urinary retention (minor) and urethrocutaneous fistula (major) (Summary Figure). Among two-stage surgeries, three children developed a major complication: penoscrotal fistula, glans dehiscence or urethral dehiscence. Among 16 children who had feminizing genitoplasty, vaginoplasty was performed in all, clitoroplasty in nine, external genitoplasty in 13, urethroplasty in four, perineoplasty in five, and total urogenital sinus mobilization in two. Two children had minor complications: one had a UTI, and one had both a mucosal skin tag and vaginal mucosal polyp. Two additional children developed a major complication: vaginal stenosis. Cosmesis scores revealed sustained improvements from 6 months post-genitoplasty, as previously reported, with all scores reported as good or satisfied.

DISCUSSION

In these preliminary data from a multi-site, observational study, parents and surgeons were equally satisfied with the cosmetic outcomes 12 months after genitoplasty. A small number of patients had major complications in both feminizing and masculinizing surgeries; two-stage hypospadias repair had the most major complications. Long-term follow-up of patients at post-puberty will provide a better assessment of outcomes in this population.

CONCLUSION

In this cohort of children with moderate to severe atypical genitalia, preliminary data on both surgical and cosmetic outcomes were presented. Findings from this study, and from following these children in long-term studies, will help guide practitioners in their discussions with families about surgical management.

Parent-Rated Severity of Illness and Anxiety among Caregivers of Children Born with a Disorder of Sex Development Including Ambiguous Genitalia

BACKGROUND/AIMS

Parents of children born with disorders of sex development (DSD) often experience anxiety, but risk factors, including parental perception of the severity of their child's DSD, have not been examined. We hypothesized that severity of illness (SOI) ratings would relate to parental anxiety, and would be higher for parents of children with a potentially life-threatening DSD (e.g., 21-hydroxylase deficiency).

METHODS

Eighty-nine parents (Mage = 33.0, 56.2% mothers) of 51 children (Mage in months = 8.7) with a DSD including ambiguous genitalia were recruited from 12 specialized DSD clinics. Parents completed questionnaires prior to genitoplasty, 6 months post-genitoplasty, and 12 months post-genitoplasty (if completed). Data were analyzed with linear mixed modeling.

RESULTS

Parental anxiety decreased over time, χ2(1) = 10.14, p < 0.01. A positive relationship between SOI and anxiety was found, with SOI being a strong predictor of anxiety (b = 0.53, p < 0.01; χ2[1] = 5.33, p < 0.05). An SOI by time interaction indicated SOI had an increasing effect on anxiety over time, b = 0.06, p < 0.05; χ2(1) = 6.30, p < 0.05. There was no diagnosis by SOI interaction.

CONCLUSION

Parental anxiety decreased over time, but those with higher SOI ratings reported greater initial anxiety followed by slower resolution over time. Underlying etiology of DSD had no effect on the relationship between SOI and anxiety.

Pressure and stretch differentially affect proliferation of renal proximal tubular cells

Renal obstruction is frequently found in adults and children. Mechanical stimuli, including pressure and stretch in the obstructed kidney, contribute to damage; animal models of obstruction are characterized by increased cellular proliferation. We were interested in the direct effects of pressure and stretch on renal tubular cell proliferation. Human HKC-8 or rat NRK-52E proximal tubule cells were subjected to either pressure [0, 60 or 90 mmHg] or static stretch [0 or 20%] for 24 or 48 h. Cell proliferation was measured by cell counting, cell cycle analyzed by flow cytometry, and PCNA and Skp2 expression were determined by qPCR or western blot. Blood gases were determined in an iSTAT system. Proliferation was also assessed in vivo after 24 h of ureteral obstruction. There was a significant increase in HKC-8 cell number after 48 h of exposure to either 60 or 90 mmHg pressure. Western blot and qPCR confirmed increased expression of PCNA and Skp2 in pressurized cells. Cell cycle measurements demonstrated an increase in HKC-8 in S phase. Mechanical stretching increased PCNA protein expression in HKC-8 cells after 48 h while no effect was observed on Skp2 and cell cycle measurements. Increased PCNA expression was found at 24 h after ureteral obstruction. We demonstrate direct transduction of pressure into a proliferative response in HKC-8 and NRK-52E cells, measured by cell number, PCNA and Skp2 expression and increase in cells in S phase, whereas stretch had a less robust effect on proliferation.

Linking the degree of virilization in females with congenital adrenal hyperplasia to genotype

Mutations of CYP21A2 variably decrease 21-hydroxylase activity and result in a spectrum of disease expressions in patients with congenital adrenal hyperplasia (CAH). We examined the association between CYP21A2 mutations and virilization (Prader score) in females with CAH. The study population included 187 CAH females with fully characterized CYP21A2 mutations. One hundred fifty-eight patients were sorted into groups by expected enzyme activity (percent of normal activity) of the less severely affected allele: (A) null, 0%; (B) I2G, 1%; (C) I172N, 2%; and (D) V281L, >2%. We observed an inverse relationship between virilization and residual enzyme activity (P < 0.001). Subjects in group A or B had a significantly higher likelihood (unadjusted odds ratio: 16; P < 0.001) of developing severe virilization compared with those in group C. Surprisingly, 24% of group D patients, whose mutation is usually associated with nonclassical (NC) CAH, had severe virilization. Among subjects with the NC P30L mutation, 66% expressed unexpected virilization. Virilization, usually leading to extensive reconstructive surgery, is highly likely in patients with null or I2G mutations; however, NC mutations (P30L/V281L) may also lead to unexpected virilization. These findings have implications for prenatal counseling and highlight the need for additional investigations into other factors that influence virilization in CAH.

Surgical outcomes and complications of reconstructive surgery in the female congenital adrenal hyperplasia patient: What every endocrinologist should know

Surgical management of classical congenital adrenal hyperplasia (CAH) in 46, XX females has evolved significantly. Virilization of the genitalia of 46, XX females with CAH begins prenatally as a result of excess fetal androgen production. Improved understanding of anatomy and surgical outcomes has driven changes in surgical techniques as well as the timing of surgery. For endocrinologists treating these patients, it is important to understand the outcome of genitoplasty, identify patients who need further treatment and direct these patients to experienced surgeons. We performed a literature search on PubMed of publications addressing CAH and genital reconstruction published in the English language from 1990 to the present. In accordance with our institutional review board, we performed a retrospective analysis of clitoroplasty and/or vaginoplasty procedures performed by a single surgeon at our institution from 1996 to 2015. We found that genital reconstruction in 46, XX CAH patients is associated with few immediate post-operative, infectious, and urinary complications. Vaginal stenosis is a common complication of vaginal reconstruction and requires evaluation by an experienced surgeon. Clitoral pain or decreased sensation can be associated with clitoral recession and clitorectomy. Outcomes in sexual satisfaction and gender identity can also be impacted by surgical technique and success. Long term follow up and patient reported feedback are crucial to our understanding and management of this special group of patients. Improved awareness and understanding of the complications of genital surgery will allow endocrinologists to know what to ask patients and be ready to provide them with a resource with the understanding and experience to help them improve their quality of life.

Hydrogel coated mesh decreases tissue reaction resulting from polypropylene mesh implant: implication in hernia repair

PURPOSE

Use of polypropylene mesh (PPM) in hernia repair is associated with tissue reactivity. We examined, in a rat model, a novel non-biodegradable hydrogel coated PPM which may allow for decreased inflammation and a decreased foreign body reaction.

METHODS

Through a dorsal midline incision, a 2 cm × 2 cm section of PPM (either coated or uncoated) was placed on the fascial surface 1.5 cm from the incision on the dorsal wall of Sprague-Dawley rats. At 2 and 12 weeks after placement, the PPM and surrounding tissue were harvested. A board-certified dermatopathologist examined H&E stained slides for fibrosis and foreign body reaction. In addition, tissues were stained for apoptotic cells, oxidative damage, macrophages, fibroblasts, neovascularization and metalloproteases.

RESULTS

At 2 and 12 weeks, there was a greater than 95 % decrease in foreign body giant cells in coated PPM samples compared to uncoated; fibrosis was decreased by 50 %. At 2 and 12 weeks, oxidative damage, fibroblast accumulation, apoptosis and macrophages were significantly decreased in coated PPM samples compared to uncoated PPM.

CONCLUSION

These results demonstrate that a non-biodegradable hydrogel coating of PPM led to significant reduction in foreign body reaction, oxidative stress and apoptosis compared to uncoated PPM in vivo, and suggest that this coating could be clinically useful in hernia repair.

Congenital adrenal hyperplasia patient perception of 'disorders of sex development' nomenclature

BACKGROUND

As the benefits of patient-centered care have become more widely recognized, it is important to understand patients' sentiments regarding aspects affecting their care. In an effort to display more sensitivity to patient concerns, the term "disorders of sex development" (DSD) was proposed in 2006 as new nomenclature to replace older terms that were considered to have negative connotations.

METHODS

The objective of the study was to examine the views of congenital adrenal hyperplasia (CAH) patients and their caregivers regarding the new nomenclature. The study was observational to evaluate the views of the CAH community, and the primary endpoint was perception of the term DSD. The study was conducted as a survey about views regarding DSD nomenclature. The survey was sent via email to eligible subjects. Along with a short introduction explaining the term DSD, the survey was sent to eligible CAH patients and their caregivers. 589 CAH patients or family members participated in the survey.

RESULTS

A total of 589 responses were received (255 classical females, 104 non-classical females, 174 males, 56 not specified) (547 U.S., 42 international) (128 CAH patients, 408 parents or other family members). 70.6% had never heard the term DSD. 71.0% disliked or strongly disliked the term DSD. 83.6% stated they did not identify with the term DSD. 76.0% felt that the term DSD has a negative effect on the CAH community. There was no significant difference in opinion of DSD between classical females and other CAH patients, between US and international, between surgical and non-surgical patients, or between patients and parents. There was no correlation with patient age.

CONCLUSIONS

Our results indicate that the majority of parents and patients with CAH are dissatisfied with the term DSD. Our results highlight the challenges within the field of DSD to reach a consensus regarding a sensitive topic and to bridge the gap between current medical practice and patient satisfaction. It is the authors' belief that reconsideration of the current nomenclature and ongoing dialogue between the medical community and patients will eventually lead to removal of stigmatization, better management protocols, and improved outcomes.

Management of adolescents with congenital adrenal hyperplasia

The management of congenital adrenal hyperplasia involves suppression of adrenal androgen production, in addition to treatment of adrenal insufficiency. Management of adolescents with congenital adrenal hyperplasia is especially challenging because changes in the hormonal milieu during puberty can lead to inadequate suppression of adrenal androgens, psychosocial issues often affect adherence to medical therapy, and sexual function plays a major part in adolescence and young adulthood. For these reasons, treatment regimen reassessment is indicated during adolescence. Patients with non-classic congenital adrenal hyperplasia require reassessment regarding the need for glucocorticoid drug treatment. No clinical trials have compared various regimens for classic congenital adrenal hyperplasia in adults, thus therapy is individualised and based on the prevention of adverse outcomes. Extensive patient education is key during transition from paediatric care to adult care and should include education of females with classic congenital adrenal hyperplasia regarding their genital anatomy and surgical history. Common issues for these patients include urinary incontinence, vaginal stenosis, clitoral pain, and cosmetic concerns; for males with classic congenital adrenal hyperplasia, common issues include testicular adrenal rest tumours. Transition from paediatric to adult care is most successful when phased over many years. Education of health-care providers on how to successfully transition patients is greatly needed.

An animal explant model for the study of human cutaneous squamous cell carcinoma

We established a human tissue explant model to facilitate study of cutaneous squamous cell carcinoma. We accomplished this by implanting debulked SCC, from surgical discard, into nude rats. Human SCC remained viable and continued to proliferate for at least 4 weeks and showed evidence of neovascularization. At 4 weeks, SCC implants showed a trend toward increased PCNA positive cells compared to fresh SCC cells/mm(2) tissue) supporting continued proliferation throughout engraftment. Von Willebrand's Factor (VWF) positive cells were found within implants and likely represented rat vessel neovascularization. Human Langerhans' (Langerin+) cells, but no T cells (CD3+, CD8+, FoxP3+), macrophages (CD163), or NK cells (NKp46), were present in SCC implants at 4 weeks. These findings support the possibility that LCs fail to migrate from cutaneous SCC and thus contribute to lack of effective antitumor response. Our findings also provide a novel model system for further study of primary cutaneous SCC.

Mast cells are required for the development of renal fibrosis in the rodent unilateral ureteral obstruction model

Mast cells are associated with inflammation and fibrosis. Whether they protect against or contribute to renal fibrosis is unclear. Based on our previous findings that mast cells can express and secrete active renin, and that angiotensin (ANG II) is profibrotic, we hypothesized that mast cells play a critical role in tubulointerstitial fibrosis. We tested this hypothesis in the 14-day unilateral ureteral obstruction (UUO) model in rats and mast cell-deficient (MCD) mice (WBB6F1-W/Wv) and their congenic controls (CC). In the 14-day UUO rat kidney, mast cell number is increased and they express active renin. Stabilizing mast cells in vivo with administration of cromolyn sodium attenuated the development of tubulointerstitial fibrosis, which was confirmed by measuring newly synthesized pepsin-soluble collagen and blind scoring of fixed trichrome-stained kidney sections accompanied by spectral analysis. Fibrosis was absent in UUO kidneys from MCD mice unlike that observed in the CC mice. Losartan treatment reduced the fibrosis in the CC UUO kidneys. The effects of mast cell degranulation and renin release were tested in the isolated, perfused kidney preparation. Mast cell degranulation led to renin-dependent protracted flow recovery. This demonstrates that mast cell renin is active in situ and the ensuing ANG II can modulate intrarenal vascular resistance in the UUO kidney. Collectively, the data demonstrate that mast cells are critical to the development of renal fibrosis in the 14-day UUO kidney. Since renin is present in human kidney mast cells, our work identifies potential targets in the treatment of renal fibrosis.

Increased cyclooxygenase-2 expression and prostaglandin E2 production in pressurized renal medullary interstitial cells

Renal medullary interstitial cells (RMICs) are subjected to osmotic, inflammatory, and mechanical stress as a result of ureteral obstruction, which may influence the expression and activity of cyclooxygenase type 2 (COX-2). Inflammatory stress strongly induces COX-2 in RMICs. To explore the direct effect of mechanical stress on the expression and activity of COX-2, cultured RMICs were subjected to varying amounts of pressure over time using a novel pressure apparatus. COX-2 mRNA and protein were induced following 60 mmHg pressure for 4 and 6 h, respectively. COX-1 mRNA and protein levels were unchanged. PGE(2) production in the RMICs was increased when cells were subjected to 60 mmHg pressure for 6 h and was prevented by a selective COX-2 inhibitor. Pharmacological inhibition indicating that pressure-induced COX-2 expression is dependent on p38 MAPK and biochemical knockdown experiments showed that NF-kappaB might be involved in the COX-2 induction by pressure. Importantly, terminal deoxyneucleotidyl transferase-mediated dUTP nick-end labeling and methylthiazoletetetrazolium assay studies showed that subjecting RMICs to 60 mmHg pressure for 6 h does not affect cell viability, apoptosis, and proliferation. To further examine the regulation of COX-2 in vivo, rats were subjected to unilateral ureteral obstruction (UUO) for 6 and 12 h. COX-2 mRNA and protein level was increased in inner medulla in response to 6- and 12-h UUO. COX-1 mRNA and protein levels were unchanged. These findings suggest that in vitro application of pressure recapitulates the effects on RMICs found after in vivo UUO. This directly implicates pressure as an important regulator of renal COX-2 expression.

Effects of transforming growth factor-beta1 on human vocal fold fibroblasts

OBJECTIVES

We studied the effect of transforming growth factor (TGF)-beta on immortalized human vocal fold fibroblasts.

METHODS

Normal human vocal fold fibroblasts were subjected to sequential lentiviral transduction with genes for human telomerase (hTERT) and SV40 large T antigen in order to produce an "immortalized" cell line of normal phenotype. After confirmation of vocal fold fibroblast transfection, these cells, referred to as HVOX, were treated with various concentrations of exogenous TGF-beta1 and assayed for collagen secretion, migration, and proliferation. In addition, components of the TGF-beta signaling pathway were examined in this cell line.

RESULTS

TGF-beta stimulated collagen secretion and migration without altering proliferation of HVOX. HVOX constitutively expressed type I and II TGF-beta receptors, as well as messenger RNA for the Smad signaling proteins and for all TGF-beta isoforms. Exogenous TGF-beta1 induced temporally dependent alterations in Smad2 and Smad3 gene expression. TGF-beta increased Smad7 expression at both 4 and 24 hours. Prolonged exposure to TGF-beta decreased TGF-beta1 gene expression.

CONCLUSIONS

Insight into the underlying pathophysiology of vocal fold fibrosis is likely to yield improved therapeutic strategies to mitigate vocal fold scarring. Our data suggest that TGF-beta signaling may be both paracrine and autocrine in this vocal fold fibroblast cell line, and we therefore propose that TGF-beta may be a reasonable target for therapies to prevent and/or treat vocal fold fibrosis, given its putative role in both acute and chronic vocal fold injury, as well as its effects on vocal fold fibroblasts.

Pressure activates epidermal growth factor receptor leading to the induction of iNOS via NFkappaB and STAT3 in human proximal tubule cells

Ureteral obstruction leads to increased pressure and inducible nitric oxide synthase (iNOS) expression. This study examined the involvement of epidermal growth factor (EGF) receptor (EGFR), nuclear factor-kappaB (NFkappaB), and signal transducers and activators of transcription 3 (STAT3) in iNOS induction in human proximal tubule (HKC-8) cells in response to pressure or EGF. HKC-8 cells were subjected to 60 mmHg pressure or treated with EGF for 0-36 h. iNOS was more rapidly induced in response to EGF than pressure. The addition of EGFR, NFkappaB, and STAT3 inhibitors significantly suppressed pressure- or EGF-stimulated iNOS mRNA and protein expression. Analysis of the activated states of EGFR, NFkappaB p65, and STAT3 after exposure to both stimuli demonstrated phosphorylation within 2.5 min. Anti-EGF antibody inhibited iNOS induction in pressurized HKC-8 cells, providing evidence that endogenous EGF mediates the response to pressure. In ureteral obstruction, when pressure is elevated, phosphorylated EGFR was detected in the apical surface of the renal tubules, validating the in vitro findings. These data indicate that EGFR, NFkappaB, and STAT3 are required for human iNOS gene induction in response to pressure or EGF, indicating a similar mechanism of activation.

A novel cell-permeable antioxidant peptide decreases renal tubular apoptosis and damage in unilateral ureteral obstruction

Unilateral ureteral obstruction (UUO) is characterized by decreases in renal function, increased interstitial fibrosis, tubular apoptosis, and cellular infiltration. It has been suggested that inhibition of tubular apoptosis may protect against renal damage in obstruction. We have recently developed a series of peptides which are concentrated in the inner mitochondrial membrane and prevent cell death. These peptides are also active in vivo, in myocardial infraction, ischemic brain injury, and amyotrophic lateral sclerosis models. We therefore used SS-31, a prototype of these peptides, and assessed its effects on renal damage and oxidative stress in a 14-day obstruction model. SS-31 (1 or 3 mg/kg) or saline was given 1 day before and throughout the 14 days of obstruction. Kidneys were harvested and assessed for apoptosis (terminal transferase-dUTP-nick-end labeling, caspase 3 expression), fibrosis (trichrome staining), macrophage infiltration, fibroblast expression (immunoperoxidase), and oxidative damage (8-OH deoxyguanosine and heme oxygenase-1 expression), cytokines, and signaling pathways (transforming growth factor-beta, CCR-1, p38-MAPK, NF-kappaB). SS-31 significantly attenuated the effects of obstruction on all aspects of renal damage which were examined, with both the 1 and 3 mg/kg doses showing efficacy. We noted increased oxidative stress in obstruction, which was also attenuated by SS-31 treatment. Signaling via NF-kappaB and p38 MAPK pathways were both affected by SS-31 treatment. This study provides a proof of concept that peptides which protect mitochondria in vitro can provide protection from renal damage in a UUO model. The mechanism by which protection is afforded requires further studies both in vitro and in vivo.

Liposome-mediated Gene Therapy in the Kidney

Gene therapy directed to the kidney has been attempted to improve renal disorders such as inherited kidney diseases and common renal diseases that cause interstitial fibrosis, tubular atrophy, and glomerulosclerosis. Viral and non-viral vectors have been tried and been modulated to obtain sufficient transgene expression. However, gene delivery to the kidney is usually difficult because of characteristics of renal cell biology. Among non-viral vectors, the liposome system is a promising procedure for kidney-targeted gene therapy. Using cationic liposome, tubular cells were effectively transduced by retrograde injection of liposome/cDNA complex. Although transgene expression was reportedly modest using cationic liposomes, this method improved renal disease models such as carbonic anhydrase II deficiency and unilateral ureteral obstruction. In contrast, HVJ-liposome system is an effective transfection method to glomerular cells using intra-renal arterial infusion and improved glomerular disease models such as glomerulonephritis and glomerulosclerosis. In addition, intra-renal pelvic injection of DNA by HVJ-liposome system showed transgene expression in interstitial fibroblasts. In kidney-targeted gene therapy, liposome-mediated gene transfer is an attractive method because of its simplicity and reduced toxicity. In spite of modest transgene expression, several renal disease models were successfully modulated by liposome system. Although one limitation of liposome-mediated gene delivery is the duration of transgene expression, the liposome/cDNA complex can be repeatedly administered due to the absence of an immune response.

Granular cell tumor of the glans penis in a 9-year-old boy

Granular cell tumor of the penis is a rare lesion, especially in the pediatric population. We present a case of a 9-year-old white boy with a granular cell tumor of the glans penis, as well as a review of literature. We also discuss clinical management and subsequent implications pertinent to lesion location.

Adeno-associated viral vector transduction of green fluorescent protein in kidney: effect of unilateral ureteric obstruction

OBJECTIVE

To evaluate adeno-associated virus (AAV) mediated renal gene transfer, by examining the localization and time course of gene expression in the kidneys of mice with unilateral ureteric obstruction (UUO) and controls. AAV is a replication-defective virus that has the potential to deliver genes into the kidney to improve renal damage after UUO.

MATERIALS AND METHODS

An AAV vector carrying a green fluorescent protein (GFP) reporter gene (rAAV-GFP) was used. In control mice, GFP expression was evaluated at 4, 7, 14 and 28 days after intrapelvic injection of rAAV or phosphate-buffered saline (PBS). In mice with UUO, the left ureter was obstructed, and 24 h later either rAAV or PBS was injected; GFP expression was evaluated 4, 7 and 14 days later by direct fluorescence.

RESULTS

In the control mice, at least 7 days was required to detect GFP expression, whereas after UUO, GFP expression was already evident at 4 days after injection. GFP was localized mainly to the medullary tubules.

CONCLUSIONS

This study shows successful transduction of GFP into mouse kidney using an AAV vector; GFP was expressed sooner in UUO kidneys than in the controls. These results show the feasibility of using AAV to transduce GFP into the obstructed kidney, and suggest that it might be useful in transducing therapeutically active agents.

Nerve Sparing Ventral Clitoroplasty: Analysis of Clitoral Sensitivity and Viability

PURPOSE

Enlargement of the clitoris is often a prominent manifestation of virilizing congenital adrenal hyperplasia and other disorders of sexual development. Controversy persists regarding the viability and sensitivity of the clitoris following clitoroplasty. We present 51 consecutive cases of nerve sparing ventral clitoroplasty performed by a single surgeon.

MATERIALS AND METHODS

Nerve sparing ventral clitoroplasty was performed in all patients. Postoperative evaluation for clitoral viability included gross examination and capillary perfusion testing. Patients older than 5 years were evaluated for clitoral sensory testing and vibratory sensory testing.

RESULTS

A total of 51 patients 4 months to 24 years old (mean age +/- SD 4.6 +/- 6.8 years) with clitorimegaly underwent nerve sparing ventral clitoroplasty. Of the patients 41 had capillary perfusion testing of the clitoris, of whom all had a viable clitoris. Ten of the 41 patients underwent clitoral sensory testing. Patients reported an average degree of sensation of 3.6 +/- 0.9 at the labia minora and 4.8 +/- 0.4 at the clitoris. Nine of the 10 patients also underwent vibratory sensory testing. Average values for the introitus, clitoris, labia and thigh were 3.56, 1.61, 5.08, and 5.83, respectively. Mean time after surgery for the patients who underwent clitoral sensory testing/vibratory sensory testing was 2.0 +/- 0.8 years. No variations in the sensitivity results were reported at followup in 2 patients.

CONCLUSIONS

To our knowledge this is the largest report of followup testing of clitoral viability and sensation after clitoroplasty. Continued long-term followup is ongoing to document long-term sexual function using this nerve sparing ventral approach for clitoroplasty.

Early upregulation of iNOS mRNA expression and increase in NO metabolites in pressurized renal epithelial cells

Pressure is an important physiological regulator, but under abnormal conditions it may be a critical factor in the onset and progression of disease in many organs. In vivo, proximal tubular epithelial cells are subjected to pressure as a result of ureteral obstruction, which may influence the production of nitric oxide (NO), a ubiquitous multifunctional cytokine. To directly explore the effect of pressure on the expression and activity of NO synthase (NOS) in cultured proximal tubular epithelial cells, a novel pressure apparatus was developed. Cells were subjected to pressures of 20-120 mmHg over time (5 min-72 h). RT-PCR demonstrated an increase in inducible NOS (iNOS) and sGC, while endothelial NOS remained unchanged. Real-time PCR (qPCR) confirmed an earlier induction of iNOS transcript subjected to 60 mmHg compared with cytokine mix. iNOS protein expression was significantly increased following 60 mmHg of pressure for 24 h. Use of nuclear factor-kappaB inhibitors was shown to prevent the increase in iNOS expression following 60 mmHg for 2 h. NO and cGMP were increased with the application of pressure. The addition of the irreversible iNOS inhibitor (1400W) was shown to prevent this increase. We demonstrate that with the use of a simply designed apparatus, pressure led to an extremely early induction of iNOS and a rapid activation of NOS activity to increase NO and cGMP in proximal tubule epithelial cells. The rapid effects of pressure on iNOS may have important implications in the obstructed kidney.

Nerve sparing ventral clitoroplasty preserves dorsal nerves in congenital adrenal hyperplasia

PURPOSE

Masculinization of the female genitalia observed in patients with classic congenital adrenal hyperplasia often results in clitorimegaly. Reduction clitoroplasty is the most widely practiced corrective surgery for clitorimegaly, yet reservations about surgical intervention exist based on fears of nerve destruction during surgical removal of excess erectile tissue. In this study, we modified the reduction clitoroplasty and examined excised erectile tissue for the presence of dorsal nerves.

MATERIALS AND METHODS

We describe the development of the nerve sparing ventral clitoroplasty. Nerves were examined in situ using optical coherence technology. In addition, erectile tissue removed from 27 female patients with congenital adrenal hyperplasia was examined immunohistochemically for the presence of nerves by staining for neurofilament. Nerves outside of the tunica albuginea were counted and measured. Tissue from 2 adult females was also examined by immunohistochemistry.

RESULTS

Optical coherence technology visualized dorsal nerves in 3 patients with congenital adrenal hyperplasia (size 600 to 800 microm). In 4 of 27 patients undergoing nerve sparing ventral clitoroplasty, no dorsal nerve branches were visualized in excised erectile tissue. In another 18 patients 10 or fewer nerve branches were found. In patients who underwent nerve sparing ventral clitoroplasty 92% of dorsal nerves detected were 90 microm or less. In contrast, 88% of dorsal nerves found in the 2 adult specimens were 120 microm or greater. The maximum nerve fiber size observed in patient specimens was significantly smaller than the maximum nerve fiber size observed in control specimens.

CONCLUSIONS

Scarcity of large dorsal nerves in histological specimens excised using nerve sparing ventral clitoroplasty likely reflects their preservation within the congenital adrenal hyperplasia patients. This preservation is vital to future somatosensory and motor function of the clitoris.

Effect of combination therapy with enalapril and the TGF-β antagonist 1D11 in unilateral ureteral obstruction

In unilateral ureteral obstruction (UUO), the kidney is characterized by increased fibrosis and apoptosis. Both transforming growth factor-β (TGF-β) and ANG II have been implicated, and ANG II may mediate its effects through TGF-β. Previous studies demonstrated amelioration of renal damage when either TGF-β or ANG II has been individually targeted. In this study, we sought to determine whether combining 1D11 (monoclonal antibody to TGF-β) and an ACE inhibitor, enalapril, would be more effective in UUO than either individual treatment, as has been shown in diabetic and glomerulonephritic models. Rats underwent UUO and were given either control monoclonal antibody, 1D11 or enalapril, or 1D11/enalapril combination, for 14 days. Kidneys were harvested and examined for fibrosis [trichrome; collagen (real-time PCR, Sircol assay) and fibroblast-specific protein expression (immunohistochemistry), apoptosis (TUNEL), macrophage infiltration (immunohistochemistry), and TGF-β expression (real-time PCR and tubular localization with immunohistochemistry)]. UUO was found to induce fibrosis, apoptosis, macrophage infiltration, and TGF-β expression in the obstructed kidney. Administration of either 1D11 or enalapril individually significantly decreased all these changes; when 1D11 and enalapril were combined, there was little additive effect, and the combination did not provide full protection against damage. The results demonstrate that, for the most part, combination therapy is not additive in UUO. This could be due to the continued presence of a physical obstruction or to biochemical differences between UUO and other renal disease models. Furthermore, it suggests that other targets may be amenable to pharmacological manipulation in UUO.

Dietary arginine supplementation attenuates renal damage after relief of unilateral ureteral obstruction in rats

BACKGROUND

Progression of renal injury after relief of unilateral ureteral obstruction (UUO) has been demonstrated. Nitric oxide (NO) may be an effective intervention due to its vasodilatory, antifibrotic, and anti-apoptotic effects. Herein, we used dietary L-arginine (ARG) supplementation in a UUO relief model.

METHODS

This study comprised group 1, control (no treatment). All other rats were subject to 3-day UUO, which was then relieved, and the rats maintained for 7 additional days. Group 2, no additional treatment; group 3, L-ARG; group 4, L-NAME, NO synthase inhibitor; group 5, ARG and L-NAME. Urinary NO(2/3) was quantified. GFR and ERPF were measured at day 10. Interstitial fibrosis and fibroblast expression, macrophage infiltration, tubular apoptosis, and proliferation, NOS expression, and the levels of tissue TGF-beta were evaluated.

RESULTS

Urinary NO(2/3) was significantly increased by ARG treatment and decreased by L-NAME. GFR and ERPF measured 7 days following relief were not significantly different in the previously obstructed kidneys (POK) of groups 2 and 3. L-NAME significantly reduced GFR and ERPF in the POK. ARG significantly reduced apoptosis, macrophage infiltration, and fibroblast expression in the POK. L-NAME exacerbated the effects on apoptosis and fibroblasts. Fibrosis was minimal in groups 1 through 3, but was significantly increased by L-NAME. ARG did not affect renal NOS expression and tissue TGF-beta1 levels.

CONCLUSION

Dietary ARG supplementation during UUO relief did not improve ERPF or GFR. However, renal damage, including fibrosis, apoptosis, and macrophage infiltration was significantly improved by ARG treatment. This suggests that increasing NO availability could be beneficial in the setting of UUO relief.

Cyclooxygenase-2 Inhibitor Decreases Extracellular Matrix Synthesis in Stretched Renal Fibroblasts

BACKGROUND/AIMS

Both TGF-beta and cyclooxygenase-2 have been implicated in the pathogenesis of interstitial fibrosis in unilateral ureteral obstruction (UUO). Cyclic tensile stretch has been used in vitro to mimic the changes in intrarenal pressure in UUO. We sought to determine the effect of meloxicam (a selective cyclooxygenase-2 inhibitor) on extracellular matrix and TGF-beta synthesis in stretched renal fibroblasts (NRK-49F).

METHODS

NRK-49F cells were subject to cyclic stretch (6 cycles/min, 15% elongation) using a Flexcell apparatus. Cells were stretched in the absence or presence of meloxicam for 48 h, and then cells and supernatants were isolated. Collagen was quantified by the Sircol assay; fibronectin and laminin were visualized using immunofluorescence. TGF-beta was quantified by ELISA, and protease activity determined by a colorimetric assay.

RESULTS

Both collagen and TGF-beta synthesis were increased following a 48-hour stretch of NRK-49F. Meloxicam significantly decreased the collagen and TGF-beta response to stretch. Stretch-induced fibronectin and laminin synthesis was also decreased by meloxicam. NRK-49F protease activity was decreased by stretch; this was unaffected by meloxicam.

CONCLUSIONS

Stretch of NRK-49F results in extracellular matrix synthesis, a process which may be activated in UUO and contribute to interstitial fibrosis. Inhibition of cyclooxygenase-2 may reduce fibrosis through a TGF-beta-dependent process.

Liposome-mediated transfer of nitric oxide synthase gene improves renal function in ureteral obstruction in rats

BACKGROUND

The protective effect of nitric oxide has been demonstrated in several renal disease models. We augmented renal nitric oxide production by transfer of the inducible nitric oxide synthase (iNOS) gene into rat kidney in controls and in unilateral ureteral obstruction (UUO).

METHODS

The human iNOS gene was inserted into a pcDNA 3.1-backbone plasmid with the FLAG epitope (FLAG-iNOS). In vitro, transduction of FLAG-iNOS was confirmed by Western blot and Griess reaction. In vivo, we transfected either FLAG-iNOS or control plasmid (CMV-LacZ), using cationic liposomes. Urinary nitric oxide metabolites and immunohistochemistry confirmed iNOS transduction. Renal function was also assessed.

RESULTS

In vitro, increased iNOS expression was demonstrated in human embryonic kidney (HEK293) cells, along with increased release of nitric oxide metabolites, NO(2)/NO(3). In vivo, FLAG-iNOS was detected by polymerase chain reaction (PCR) up to 35 days after the transfection. Urine collection documented increased urinary NO(2)/NO(3). Immunohistochemistry localized iNOS to collecting ducts, distal tubules, and glomerulus of the injected kidney. Renal function measured up to 21 days after transfection in control animals was not significantly different between the two groups. In contrast, renal function after 24 hours of UUO was significantly improved in FLAG-iNOS-treated animals.

CONCLUSION

This study demonstrates the feasibility of liposome-mediated iNOS gene transfer into the kidney. Furthermore, the improvement of renal function in UUO demonstrates that the transfected iNOS gene is active and suggests that decreased iNOS activity contributes to the decreased renal function in UUO. This iNOS construct may have therapeutic utility in the pathophysiologic sequelae of UUO and other renal diseases.

PATHOPHYSIOLOGY OF UNILATERAL URETERAL OBSTRUCTION: STUDIES FROM CHARLOTTESVILLE TO NEW YORK

PURPOSE

More than 30 years ago the decreased renal blood flow and glomerular filtration rate characteristic of unilateral ureteral obstruction (UUO) was described. In the ensuing time, much has been learned about the involvement of nitric oxide (NO) and transforming growth factor-beta (TGF-beta) in the pathophysiology of UUO.

MATERIALS AND METHODS

We measured renal blood flow and glomerular filtration rate in dogs and rats, and assessed the effect of altering the availability of NO on these parameters. In rats and mice we used an antibody to TGF-beta, NO synthase gene deletion and inducible nitric oxide synthase gene therapy to assess the role of TGF-beta and NO in renal fibrosis.

RESULTS

Results of our studies suggest 2 strategies that have the potential to be incorporated into clinical trials. The first would be replenishment of the NO system with arginine (or a NO donor) to decrease renovascular resistance and increase renal nitric oxide. Either in addition to the first strategy or separately, interstitial fibrosis could be targeted. Strategies for inhibiting fibrosis include antibody to TGF-beta, use of antisense oligonucleotides to TGF-beta, use of drugs that inhibit other pro-fibrotic mediators or gene therapy to inhibit fibrosis.

CONCLUSIONS

While these studies have primarily centered on acute UUO, the findings in this model of renal injury may potentially be transferable to other entities that are characterized by decreased renal function and increased renal fibrosis such as different forms of interstitial nephropathy or diabetic glomerulopathy.

Nerve sparing extravesical repair of bilateral vesicoureteral reflux: description of technique and evaluation of urinary retention

PURPOSE

Prolonged urinary retention remains a controversial and feared complication following bilateral extravesical ureteral reimplantation. We report a modified approach to limit detrusor nerve damage during extravesical correction of bilateral ureteral reflux that significantly reduces this adverse outcome.

MATERIALS AND METHODS

A modified approach to the distal detrusor dissection and ureteral mobilization, along with limited periureteral dissection, was used to perform this technique. A retrospective review of 50 patients undergoing bilateral nerve sparing extravesical ureteral reimplantation (NSEVR) by a single surgeon between 1997 and 2002 was completed. Patient age, vesicoureteral reflux (VUR) grade, length of hospital stay, length of surgery and outcome were evaluated.

RESULTS

The study included 36 girls and 14 boys, with an average age of 4 years 11 months (range 1 to 14 years). Average preoperative VUR grade was 2.61 (range 1 to 5). Average length of surgery when NSEVR was the only procedure performed was 105 minutes (range 54 to 185) and average length of hospital stay was 1.76 days (0 to 3). Transient urinary retention developed in 1 child on postoperative day 1, with a successful trial of voiding the next day. The rate of immediate urinary retention was 2%. There was no long-term urinary retention, voiding dysfunction or urinary tract infections.

CONCLUSIONS

NSEVR for the correction of bilateral VUR is a simple modification that provides a reproducible and minimally invasive approach to treatment. We believe that limited distal ureteral dissection, preservation of the medial ureterovesical hiatus and judicious manipulation of the surrounding tissues result in elimination of long-term urinary retention.

Testosterone treatment of human foreskin in a novel transplant model

OBJECTIVES

To determine whether testosterone would increase angiogenesis in human foreskin, because of the known effects of testosterone on endothelial cells and vascular endothelial growth factor expression. Surgical management of complex hypospadias in a patient who has undergone multiple procedures is technically very challenging. It is possible that therapy to increase the blood supply to this tissue could be beneficial.

METHODS

We used a newly developed model of human skin transplantation, in which full-thickness human foreskin is transplanted subcutaneously onto the dorsum of a nude rat. At 10 days after transplantation, tissue was treated with either testosterone gel or vehicle control. After an additional 7 days, the tissue was harvested, embedded in paraffin, stained for factor VIII to assess vascularity, and examined histologically.

RESULTS

The testosterone-treated tissue demonstrated increased factor VIII staining (31.14 +/- 1.53 vessels per high-power field) compared with the control group (18.25 +/- 2.3 vessels per high-power field; P <0.0005). Histologic analysis revealed less collagen in the testosterone-treated group compared with the control group.

CONCLUSIONS

Treatment of human foreskin with testosterone, in a transplant model, increased vascularity and decreased early fibrosis. Testosterone treatment may improve the surgical management of complex hypospadias repair.

Renal damage progresses despite improvement of renal function after relief of unilateral ureteral obstruction in adult rats

Progression of renal damage after relief of unilateral ureteral obstruction (UUO) has been demonstrated, especially in neonatal rats. We evaluated renal function and renal damage after relief of 3-day UUO in five groups of adult rats: group 1, no treatment; group 2, 3-day UUO; groups 3-5, 3-day UUO followed by relief; group 3, 7-day relief; group 4, 14-day relief; and group 5, 28-day relief. Glomerular filtration rate (GFR), renal blood flow (RBF), tissue transforming growth factor-beta (TGF-beta), interstitial fibrosis and fibroblast expression, tubular apoptosis, macrophage infiltration, expression of nitric oxide synthases (NOS), and urinary nitrate/nitrite (NO(2)/NO(3)) were evaluated. RBF and GFR were decreased to <10% of baseline by 3 days of UUO. GFR and RBF in a previously obstructed kidney (POK) returned to baseline by 14 days after relief. Both tissue TGF-beta(1) and interstitial fibrosis were significantly higher in POK of groups 3-5 compared with groups 1 and 2 . In group 5, the numbers of infiltrating macrophages, fibroblasts, and apoptotic tubular cells were higher in POK compared with group 1. Urinary NO(2)/NO(3) was significantly higher than baseline from 3 to 27 days after relief of UUO. Expression of NOS isoforms was increased in tubules. As interstitial fibrosis contributes to decreased renal function, these results suggest that the acute recovery in function may be compromised in the long term by the progressive renal fibrosis which was found. Furthermore, pharmacological intervention at the time of relief of UUO, targeted to fibrotic processes, may contribute to long-term recovery of renal function.

Effect of UUO on D1aR expression reveals a link among dopamine, transforming growth factor-β, and nitric oxide

Interactions between transforming growth factor-β (TGF-β) and nitric oxide (NO) are important in the pathophysiology of unilateral ureteral obstruction (UUO). Dopamine (DA) is a vasoactive renal mediator active at the D1Areceptor (D1AR), which has not been studied in UUO; therefore, we examined the interactions among DA, TGF-β, and NO in UUO. In vivo, UUO was carried out in rats with or without concurrent treatment with 1D11, a monoclonal antibody to TGF-β, for 14 days. In vitro, NRK-52E cells (normal rat kidney tubules) were treated with DA, and NO and TGF-β release were examined. UUO resulted in a 70% decrease in the expression of renal D1AR, confirmed by both Western blot analysis and immunohistochemistry. 1D11 treatment restored expression to 60% of control values. DA treatment decreased NRK-52E release of TGF-β by 80%; conversely, DA significantly increased NO release from NRK-52E cells. These results suggest that DA modulates the release of cytokines, which are involved in the fibrotic and apoptotic sequelae of UUO, and that these effects are independent of DA's known vasoactive properties.

Dietary L-Arginine Supplementation Improves the Glomerular Filtration Rate and Renal Blood Flow After 24 Hours of Unilateral Ureteral Obstruction in Rats

PURPOSE

Unilateral ureteral obstruction (UUO) results in a significant change in renal blood flow (RBF) and glomerular filtration rate (GFR) by 24 hours. The intake of L-arginine, a substrate of nitric oxide (NO) synthase (NOS), can augment NO production. NO can maintain renal function through its vasodilatory action. Therefore, we examined the effect of dietary arginine supplementation on renal function in UUO.

MATERIALS AND METHODS

GFR and RBF were measured by inulin and para-aminohippurate clearance, respectively, in control rats and in rats 24 hours after UUO. Rats were given arginine with or without the concomitant administration of N-nitro-L-arginine methyl ester. Urinary nitrate/nitrite (NO2/NO3) was measured by the Griess reaction and urinary cyclic guanosine monophosphate was determined by enzyme-linked immunosorbent assay. The expression of renal inducible NOS was determined by immunohistochemistry.

RESULTS

Urinary NO2/NO3 was significantly increased after 2 weeks of arginine, confirming increased NO production. In control rats GFR and RBF were not significantly different in untreated vs arginine treated groups. In contrast, arginine treatment significantly increased GFR in the obstructed kidney (0.06 +/- 0.01 to 0.14 +/- 0.02 ml per minute per 100 gm) and the contralateral kidney compared with control UUO. RBF was also significantly increased by arginine. The increases in renal function with arginine were blunted by a NOS inhibitor in obstructed and contralateral kidneys. Inducible NOS expression was increased in obstructed and contralateral kidneys.

CONCLUSIONS

This study demonstrates that L-arginine supplementation can improve renal function in acute UUO. This finding suggests that NO system may be a future site of pharmacological intervention for UUO.

Full-thickness human foreskin transplantation onto nude rats as an in vivo model of acute human wound healing

Current wound-healing models do not fully duplicate the in vivo human environment. The feasibility of grafting human full-thickness foreskin onto nude rats, as a model of acute wound healing, was evaluated. Incisions were then created on the grafted skin, and wound healing was evaluated. Full-thickness human skin was obtained after elective circumcision and was grafted subcutaneously onto the dorsal thorax of nude rats. At 10 days after transplantation, graft beds were judged for graft viability, on the basis of gross appearance, texture, and adherence. Full-thickness wounds were then made in the foreskin. Graft wounds were left to close by secondary intention. The wounds were allowed to heal for 7 days. Wounds were excised and tested for breaking stress. Histological evaluations included proliferating cell nuclear antigen, factor VIII, hematoxylin and eosin, and trichrome staining. Twenty grafts were performed, with 100 percent viability. Upon incision, all grafts bled freely, indicating a rich vascular supply and tissue viability. Graft viability was confirmed by the presence of proliferating cells in the parabasal stratum of the epithelium. Furthermore, there was evidence of angiogenesis, as confirmed by staining for factor VIII. Breaking stress was evaluated by tensiometry, 7 days after wounding. Histological evaluations revealed viable grafts and active wound-healing events. Full-thickness human skin can be successfully transplanted onto nude rats, providing a larger, more physiological model of human wound healing. This model closely parallels the in vivo situation, providing a promising model for study of the complex biological processes of acute human wound healing, in a reproducible manner.