Fetal lower urinary tract obstruction: proposal for standardized multidisciplinary prenatal management based on disease severity.

OBJECTIVE: To present a single center experience of a standardized prenatal multidisciplinary management protocol for fetal lower urinary tract obstruction (LUTO) and to propose a classification of fetal LUTO based on disease severity. METHODS: This was a retrospective cohort study of 25 consecutive fetal patients with prenatal diagnosis of primary LUTO. Fetal intervention was offered after evaluation by a multidisciplinary team. Analyses were conducted using Bayesian methodology to determine predictors of survival at 6 months postpartum. Odds ratios (ORs) with 95% credibility intervals are reported. RESULTS: Fifteen (60.0%) of the 25 patients referred for assessment survived to postnatal evaluation. Fetal vesicoamniotic shunt was placed in 14 (56.0%) patients with 12 survivors. Multivariable analysis suggested that fetal intervention (OR, 6.97 (0.88-70.16), Pr(OR > 1) = 96.7%), anhydramnios (OR, 0.12 (0.04-0.35), Pr(OR < 1) = 99.9%), favorable fetal urine analysis (OR, 3.98 (0.63-25.15), Pr(OR > 1) = 92.7%) and absence of renal cortical cysts (OR, 3.9 (0.66-24.2), Pr(OR > 1) = 93.3%) were predictors of survival. CONCLUSIONS: Fetal intervention and fetal renal function were independently associated with postnatal survival of fetuses with LUTO. A classification based on the severity of disease is proposed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Congenital heart anomaly in newborns with congenital diaphragmatic hernia: a single-center experience.

OBJECTIVE: To evaluate the impact of the presence of a congenital heart anomaly (CHA) and its potential contribution to morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). METHODS: In this retrospective cohort study, prenatal and postnatal data of all newborns diagnosed with CDH between January 2004 and December 2012 in a single center were reviewed. Cases were classified into two groups: those with 'isolated' CDH and those with both CDH and CHA. Patients with CHA were further subclassified into those with a major or minor CHA based on the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1), and the Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery (STS-EACTS) scoring systems. Patients with associated non-cardiac anomalies, including 'syndromic cases', were excluded from the analysis. Primary and secondary outcomes were survival up to 1 year of age and a need for extracorporeal membrane oxygenation (ECMO), respectively. RESULTS: Of the 180 infants with CDH, 41 were excluded because of the presence of non-cardiac associated anomalies, 118 had isolated CDH and 21 had CDH with CHA (16 with minor and five with major CHA). Receiver-operating characteristics curve analysis demonstrated that the best cut-off for survival was when the score for CHA was ≤ 2 for both RACHS-1 (area under the curve (AUC), 0.74 (P = 0.04); sensitivity, 80.0%; specificity, 87.5%) and STS-EACTS (AUC, 0.83 (P = 0.03); sensitivity, 100%; specificity, 87.5%). Survival rate at 1 year was significantly lower in those with CHD and a major CHA (40.0%; P = 0.04) than in those with isolated CDH (77.1%) and those with CDH and a minor CHA (81.3%). We found no significant differences among the groups with regard to the need for ECMO. CONCLUSIONS: In general, a milder form of CHA does not appear to have a negative impact on the survival of infants with CDH. However, mortality appears to be significantly higher in infants with CDH and a major form of CHA. The scoring systems appear to be useful as predictors for classifying the effects of CHA in this population of patients.

Quantification of liver herniation in fetuses with isolated congenital diaphragmatic hernia using two-dimensional ultrasonography.

OBJECTIVES: To describe a method of quantifying the amount of liver herniation in fetuses with isolated congenital diaphragmatic hernia (CDH) using two-dimensional ultrasonography and to correlate this finding with neonatal outcome. METHODS: Ultrasound images obtained from 77 consecutive fetuses that presented with isolated CDH between January 2004 and July 2012 were reviewed. Liver herniation and thoracic area were measured in a cross-sectional plane of the fetal chest at the level of the four-chamber view of the heart (the same section as is used to measure the lung area-to-head circumference ratio) and the ultrasound-derived liver-to-thoracic area ratio (US-LiTR) was calculated by dividing the liver herniation area by the thoracic area. Receiver-operating characteristics (ROC) curve analysis was used to evaluate the performance of US-LiTR in predicting neonatal outcome (survival to 6 months after delivery and need for extracorporeal membrane oxygenation (ECMO)). In addition, the US-LiTR was compared with the magnetic resonance imaging (MRI)-derived volume ratio (MRI-LiTR) and percentage of liver herniation (MRI-%LH). RESULTS: The overall neonatal mortality in the 77 cases with isolated CDH was 20.8% (16/77). ECMO was needed in 35.5% (27/76) of the newborns, with a survival rate of 52%. The US-LiTR was associated statistically with mortality (P < 0.01) and with the need for ECMO (P < 0.01). Good correlations were observed between US-LiTR and MRI-LiTR (r = 0.87; P < 0.001) and between US-LiTR and MRI-%LH (r = 0.90; P < 0.001). Based on ROC curve analysis, all three parameters had similar accuracy in predicting mortality (US-LiTR: area under the ROC curve (AUC), 0.78 (95% CI, 0.65-0.92), P < 0.01; MRI-LiTR: AUC, 0.77 (95% CI, 0.63-0.90), P < 0.01; MRI-%LH: AUC, 0.79 (95% CI, 0.65-0.92), P < 0.01, respectively) as well as the need for ECMO (US-LiTR: AUC, 0.72 (95% CI, 0.60-0.84), P < 0.01; MRI-LiTR: AUC, 0.73 (95% CI, 0.60-0.88), P < 0.01; MRI-%LH: AUC, 0.77 (95% CI, 0.64-0.89), P < 0.01, respectively). CONCLUSIONS: Two-dimensional ultrasound measurement of the amount of liver herniation in fetuses with isolated CDH is feasible and demonstrates a predictive accuracy for neonatal outcome similar to that of MRI.

Fetal lung volume and quantification of liver herniation by magnetic resonance imaging in isolated congenital diaphragmatic hernia.

OBJECTIVE: To determine associations between fetal lung and liver herniation volumes measured by magnetic resonance imaging (MRI) and mortality/need for extracorporeal membrane oxygenation (ECMO) in cases of isolated congenital diaphragmatic hernia (CDH). A secondary objective was to compare prenatal MRI parameters with two-dimensional ultrasound lung measurements. METHODS: A retrospective review of medical records of all fetuses with isolated CDH evaluated between January 2004 and July 2012 was performed. The following MRI parameters were measured at 20-32 weeks: observed/expected total fetal lung volume (o/e-TLV), predicted pulmonary volume (PPV), percentage of liver herniated into the fetal thorax (%LH) and the liver/thoracic volume ratio (LiTR). These were compared with the ultrasound-determined lung-to-head ratio (LHR) and the observed/expected LHR (o/e-LHR) in the same cohort. The predictive value of MRI and ultrasound parameters for mortality and the need for ECMO was evaluated by univariate, multivariate and factor analysis and by receiver-operating characteristics curves. RESULTS: Eighty fetuses with isolated CDH were evaluated. Overall mortality was 18/80 (22.5%). Two newborns died a few hours after birth. ECMO was performed in 29/78 (37.2%) newborns, with a survival rate of 48.3% (14/29). The side of the diaphragmatic defect was not associated with mortality (P = 0.99) or the need for ECMO (P = 0.48). Good correlation was observed among o/e-TLV, PPV, LHR and o/e-LHR as well as between %LH and LiTR (r = 0.89; P < 0.01); however, fetal lung measurements and measures of liver herniation were not correlated (all P > 0.05). All parameters were statistically associated with mortality or the need for ECMO. The best combination of measurements to predict mortality was o/e-TLV and %LH, with 83% accuracy. CONCLUSION: Mortality and the need for ECMO in neonates with isolated CDH can be best predicted using a combination of MRI o/e-TLV and %LH.

MNGIE with lack of skeletal muscle involvement and a novel TP splice site mutation.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive multisystem disorder caused by thymidine phosphorylase (TP) deficiency, resulting in severe gastrointestinal dysmotility and skeletal muscle abnormalities. A patient is reported with a classical MNGIE clinical presentation but without skeletal muscle involvement at morphological, enzymatic, or mitochondrial DNA level, though gastrointestinal myopathy was present. MNGIE was diagnosed by markedly raised plasma thymidine and reduced thymidine phosphorylase activity. Molecular genetic analysis showed a homozygous novel splice site mutation in TP. On immunohistochemical studies there was marked TP expression in the CNS, in contrast to what has been observed in rodents. It is important to examine the most significantly affected tissue and to measure TP activity and plasma thymidine in order to arrive at an accurate diagnosis in this condition.

Surgery for ovarian masses in infants, children, and adolescents: 102 consecutive patients treated in a 15-year period.

BACKGROUND/PURPOSE: Ovarian pathology, although rare in children, must be included in the differential diagnosis of all girls who present with abdominal pain, an abdominal mass, or precocious puberty. METHODS: To improve clinical appreciation of these lesions, the authors reviewed the presentation, evaluation, and outcome of all patients with ovarian pathology surgically treated at their institution since 1985. RESULTS: One hundred two girls (aged 9.8 +/- 5.5 years; range, 2 days to 20 years) underwent 106 separate ovarian operations (43 salpingo-oophorectomies, 21 oophorectomies, 33 ovarian cystectomies, and 9 ovarian biopsies). Of those presenting with acute abdominal pain (n = 59), 25 (42%) had ovarian torsion (14 associated with a mature teratoma), and only 1 (2%) had a malignant tumor. In contrast, of those presenting with an abdominal mass (n = 23), 6 (26%) had malignancies. There was no age difference between those with benign disease (9.9 +/- 5.6 years; n = 96) and those with malignant tumors (8.6 +/- 3.9 years, n = 10). Nine children had 10 operations for presumed malignant tumors (3 dysgerminomas, 2 immature teratomas with foci of yolk sac tumor, 2 juvenile granulosa cell tumors, 1 yolk sac tumor, and 1 Sertoli-Leydig cell tumor). These patients all had unilateral salpingo-oophorectomy, 4 had chemotherapy, and all are now disease free at 8.4 +/- 4.1 years follow-up. CONCLUSION: Ovarian pathology remains a rare indication for surgery in girls less than 20 years of age. Because most of these lesions are benign, ovarian-preserving operations should be performed whenever feasible.

Peritoneal drainage as definitive treatment for neonates with isolated intestinal perforation.

BACKGROUND/PURPOSE: To better define the indications for peritoneal drainage (PD) in premature babies with intestinal perforation, the authors reviewed their experience with this procedure in a tertiary neonatal intensive care setting. METHODS: The charts of all neonates who underwent PD as initial treatment for intestinal perforation between 1996 and 1999 were reviewed. Those patients with pneumatosis intestinalis on abdominal radiograph had perforated necrotizing enterocolitis (NEC) diagnosed; whereas, those infants with no pneumatosis had isolated intestinal perforation diagnosed. The clinical characteristics and outcomes of these 2 groups were compared. RESULTS: Twenty-one premature neonates had primary PD between 1996 and 1999, 10 for isolated intestinal perforation and 11 for perforated NEC. Patients with isolated intestinal perforation had lower birth weights (708 v 949 g; P < .05), were less likely to have started feedings (30% v 91%, P < .05), and the perforation developed at an earlier age (10.6 v 28.0 d, P < .05) compared with the patients who had perforated NEC. Only 2 of 10 infants with isolated perforation required subsequent laparotomy (at 10 weeks for stricture and 12 weeks for a persistent fistula). For these patients, the long-term survival rate was 90%. In contrast, 8 of 11 infants with perforated NEC required laparotomy, and although the 30-day survival rate was 64%, the long-term survival rate was only 27%. CONCLUSIONS: Peritoneal drainage provides successful and definitive treatment for most premature babies with isolated intestinal perforation. For neonates with perforation caused by NEC, peritoneal drainage may provide temporary stabilization, but most of these infants require subsequent laparotomy, and few survive.

Serum hyaluronan and its association with unfavorable histology and aggressiveness of heterotransplanted Wilms' tumor.

BACKGROUND/PURPOSE: The sera and urine of children with Wilms' tumor (WT) often contain increased concentrations of hyaluronan (HA). The authors developed a heterotransplant model to investigate whether serum HA concentrations could predict the histology and progression of WT. METHODS: Random portions of 8 human WT specimens (7 favorable and 1 unfavorable histology findings) were heterotransplanted into the flanks of severe combined immunodeficient (SCID) mice. After 6 to 20 weeks of observation, animals were killed, and serum HA concentrations, tumor histology, and local invasion were determined. RESULTS: Sera of mice supporting tumor growth had a median HA concentration of 9,379 microg/L (range, 459 to 3,206,176 microg/L) compared with a median HA concentration of 416 microg/L (range, 204 to 782 microg/L) in animals not supporting tumor growth. The highest serum HA concentrations were detected in animals harboring unfavorable histology blastemal-predominant tumors, whereas animals supporting favorable histology epithelial- and stromal-predominant tumors had the lowest serum HA concentrations. In association with markedly increased serum HA, undifferentiated blastemal tumors showed significantly greater growth rates than the more differentiated epithelial or stromal tumors. Additionally, serum HA concentrations were greater in mice with invasive as compared with noninvasive tumors for each histological type. Complete resection of established tumors also resulted in the return of serum HA to preheterotransplant concentrations. Identification of tumor progression was further tested in SCID mice receiving subcutaneous flank injections of the human WT cell line, SK-NEP-1. Significantly greater serum HA concentrations again corresponded with more rapid growth rates and invasiveness. CONCLUSIONS: Serum HA concentrations predict the growth, invasion, and unfavorable histology findings of WT in a heterotransplant model. The authors further speculate that HA may foster an environment conducive to WT aggressiveness.

Elevated platelet-derived growth factor-B in congenital cystic adenomatoid malformations requiring fetal resection.

BACKGROUND: During lung development, platelet-derived growth factor-BB (PDGF-BB) is maximal during the canalicular stage and decreases by the saccular stage. PDGF-BB stimulates lung growth by increasing cell proliferation. Fetal CCAMs have been shown to have an elevated proliferative index, but it is not known why some CCAMs rapidly enlarge in utero and cause fetal hydrops. The authors hypothesized that the high proliferative index and rapid enlargement of some fetal CCAMs may be caused by persistently elevated PDGF-BB production compared with normal fetal lung. METHODS: To test this hypothesis, tissue was obtained at the time of resection from two fetal CCAMs (22 weeks), three full-term CCAMs, and three normal fetal lungs (21 to 22 weeks). PDGF-BB production by fetal CCAMs was compared with normal age-matched fetal lung using immunohistochemistry, reverse transcriptionase-polymerase chain reaction (RT-PCR), and Western blot analysis. RESULTS: CCAMs resulting in fetal hydrops and requiring fetal resection had strong mesenchymal immunostaining for PDGF-BB next to epithelial lined cysts, increased PDGF-B gene expression by RT-PCR, and elevated PDGF-BB protein by Western blot, compared with normal age-matched fetal lung. Term CCAMs had minimal PDGF-BB staining, PDGF-B gene expression, and PDGF-BB protein production. CONCLUSIONS: CCAMs that grew rapidly and progressed to hydrops, requiring in utero resection, demonstrated increased mesenchymal PDGF-B gene expression and PDGF-BB protein production compared with age-matched normal fetal lung, which may, in part, be responsible for the autonomous growth and proliferation seen in hydropic fetal CCAMs.

BAPS Prize--1997. Fetal gene therapy: efficacy, toxicity, and immunologic effects of early gestation recombinant adenovirus. British Association of Paediatric Surgeons.

BACKGROUND/PURPOSE: Advancements in gene transfer technology and prenatal diagnosis have allowed investigators to consider an in utero gene therapy approach for fatal genetic diseases. The authors sought to develop fetoscopic techniques for gene delivery and investigate the efficacy and safety of recombinant adenoviral vectors in the fetus. METHODS: Fetal sheep between 60 and 130 days' gestation (dGA) underwent either fetoscopic intratracheal injection or umbilical vein (UV) injection of recombinant adenovirus, AdCMVlacZ. At death, fetal organs were examined for beta-galactosidase expression, histopathology, and CD45 immunostaining. Fetal serum was compared with preimmune serum for transaminase levels and the presence of antiadenoviral neutralizing antibodies. RESULTS: Fetoscopic intratracheal delivery of AdCMVlacZ in late-gestation sheep fetuses resulted in efficient alveolar gene transfer, but, antiadenoviral immunologic reactions limited the longevity of transgene expression to 14 days. This prompted an examination of whether early gestational exposure could induce tolerance in the fetus to adenoviral and transgene antigens. AdCMVlacZ (1 x 10(11) particles) was injected via UV into fetuses at 60 dGA. Within 3 days, beta-galactosidase expression was localized to the fetal liver, adrenal glands, kidneys, and endocardium. Although adrenal expression was nearly constant over 28 days, expression in fetal liver disappeared within 14 to 28 days. Loss of hepatic expression did not appear to be immune mediated because there was no evidence of hepatic inflammation or appearance of antiadenoviral neutralizing antibodies. Fetuses injected with AdCMVlacZ at 60 dGA were reinjected with 1 x 10(13) particles at 125 dGA and antiadenoviral humoral immune responses were recorded. Despite early-gestation adenovirus injection, fetuses still responded to the late-gestation adenoviral exposure, developing antiadenoviral neutralizing antibodies similar to control fetuses. CONCLUSIONS: The authors developed fetoscopic access for pulmonary adenovirus delivery in late-gestation sheep. Although initial alveolar transduction was highly efficient, antiadenoviral immune responses limited the duration of transgene expression. In contrast, early-gestation adenoviral delivery did not elicit antiadenoviral immune responses despite achieving efficient transduction of many fetal tissues. Furthermore, early-gestation adenovirus delivery did not affect late-gestation antiadenoviral immune responses. These findings suggest that the early-gestation sheep fetus is not amenable to adenoviral tolerance induction by UV injection and that it is incompetent of immunologic response to adenovirus. For the purposes of in utero gene therapy, recombinant adenovirus may be applied optimally to genetic diseases requiring transient in utero expression.

Hyaluronan receptor expression increases in fetal excisional skin wounds and correlates with fibroplasia.

BACKGROUND/PURPOSE: The midgestation fetus heals incisional skin wounds scarlessly, whereas large excisional wounds scar. High concentrations of hyaluronan (HA) are associated with scarless fetal as opposed to scar-forming adult wound repair. Because expression of the HA receptors, CD44 and RHAMM (Receptor for HA-Mediated Motility), has been associated with adult wound fibroplasia, the authors postulated that fetal excisional wounds would show increased expression of CD44 and RHAMM as compared with incisional wounds. METHODS: Two models of fetal wound healing were examined. Fetal skin from human abortuses was heterotransplanted subcutaneously into severe combined immunodeficient (SCID) mice. Fourteen days after grafting, incisional or 2-mm excisional wounds were created (n = 6 per time-point). In addition, incisional and excisional (6 to 10 mm) wounds (n = 5 per time-point) were created on the backs of 70- to 75-day fetal lambs (term, 145 days). Tissue from both models was harvested at sequential time-points after injury. Wounds were studied histologically for fibroplasia and assayed for their HA content. CD44 and RHAMM expression were analyzed by immunohistochemistry and immunoblotting. RESULTS: As expected, in both models, incisional wounds healed scarlessly, whereas excisional wounds showed fibroplasia. Incisional wounds of fetal lambs maintained a significantly higher HA content than excisional wounds 3 days after injury. Between 1 and 7 days in either human or sheep fetal wounds, immunostaining for CD44 and RHAMM markedly increased along the margins of excisional wounds as compared with incisional wounds and unwounded skin. Immunoblot analysis confirmed this increased HA receptor expression in both models. CONCLUSIONS: HA receptor expression increased in both human and sheep fetal excisional wounds and correlated with fibroplasia and a reduced HA content. The authors speculate that strategies to limit the expression or function of HA receptors during postnatal wound repair may modify the development of scar.

Increased cell proliferation and decreased apoptosis characterize congenital cystic adenomatoid malformation of the lung.

BACKGROUND/PURPOSE: Congenital cystic adenomatoid malformations (CCAM) are lung lesions that demonstrate abnormalities of both mesenchymal and epithelial tissues. The pathogenesis of these tumors remains unknown. Because normal organogenesis requires a balance between cell proliferation and programmed cell death (apoptosis), the authors hypothesized that CCAM results from an increase in cell proliferation or a decrease in apoptosis within the developing lung, possibly mediated by keratinocyte growth factor (KGF). METHODS: To examine cell cycle control in CCAM, we measured indices of cell proliferation and apoptosis in lesions requiring fetal (n = 4) or neonatal (n = 8) resection compared with those of normal fetal (14 to 28 weeks' gestation; n = 14) and neonatal (n = 3) human lung. Cell proliferation was analyzed by immunostaining for a proliferation marker (Ki-67). Apoptosis was examined using an in situ digoxigenin end-labeling technique to localize apoptotic bodies. The expression of KGF protein and KGF mRNA in CCAM and normal lung was examined using immunohistochemistry and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: CCAM lesions in general showed a twofold increase in cell proliferation index (19.2% +/- 1.4% v 9.6% +/- 0.7%, P < .00005) and a fivefold decrease in apoptotic bodies (0.9 +/- 0.2 v 4.5 +/- 0.5, P < .0005) compared with age-matched normal lung. CCAMs that required resection before birth had the highest cell proliferation index. There were no differences in the expression of KGF protein or KGF mRNA in CCAM and normal lung. CONCLUSIONS: These results demonstrate that CCAM differs from normal lung by increased cell proliferation and decreased apoptosis. The increased proliferation does not appear to be mediated by the pneumocyte mitogen KGF. An examination of factors that control cell proliferation and apoptosis in CCAM may provide further insight into the pathogenesis of this tumor.

Diminished interleukin-8 (IL-8) production in the fetal wound healing response.

BACKGROUND: Fetal skin wound healing results in scarless repair with minimal cellular inflammatory response. Interleukin-8 (IL-8) stimulates inflammation in postnatal wound healing but little is known about its role in fetal wounds. We hypothesized that fetal tissues have diminished IL-8 during wound repair and in response to platelet-derived growth factor (PDGF), a growth factor central to wound healing. MATERIALS AND METHODS: To examine the IL-8 response of fibroblasts to PDGF, cultures of human fetal (17-18 weeks) and adult dermal fibroblasts were incubated 8 h with PDGF (0, 0.1, 1, or 10 ng/mL) and supernatants and cells were collected for IL-8 ELISA and IL-8 RT-PCR. To evaluate the IL-8 response to wounding, human adult and fetal skin was placed subcutaneously in the SCID mouse, wounded, and the wound cleft excised after 4, 12, 24, or 72 h for IL-8 RT-PCR. RESULTS: Fetal fibroblasts produced less IL-8 protein at baseline (50 +/- 6 pg/mL versus 450 +/- 115 pg/mL, P < 0.001) and in response to all concentrations of PDGF examined (P < 0.001). IL-8 mRNA was detected in unstimulated adult fibroblasts but not in fetal fibroblasts. Much less IL-8 mRNA was detected in stimulated fetal fibroblasts than in adult fibroblasts. IL-8 mRNA was detected 4 h after wounding in fetal and adult wounds. By 12 h no IL-8 mRNA was detected in fetal wounds, whereas adult wounds had IL-8 mRNA persisting to 72 h. CONCLUSIONS: Diminished inflammatory cytokine response by fetal tissues may be responsible for the lack of cellular recruitment and inflammation seen in fetal wound healing and may contribute to scarless wound repair.

Modulation of the human homeobox genes PRX-2 and HOXB13 in scarless fetal wounds.

Scarless healing of cutaneous wounds occurs in humans during the first two trimesters of development, but by birth all wounds are repaired with scar formation. To search for transcriptional regulatory genes that might mediate fetal tissue regeneration, we surveyed homeobox gene expression in proliferating fetal fibroblasts and in wounded and unwounded skin. Two novel human homeobox genes, PRX-2 and HOXB13, were identified that were differentially expressed during fetal versus adult wound healing. Both genes were predominantly expressed in proliferating fetal fibroblasts and developing dermis, and PRX-2 was downregulated in adult skin. In a model of scarless fetal skin regeneration, PRX-2 expression was strongly increased compared with unwounded skin and the signal was localized to the wounded dermis, the site of scarless repair. Conversely, in adult skin weak epidermal PRX-2 expression was observed, mRNA levels were not increased by wounding, and no dermal expression was detected. HOXB13 expression was decreased in wounded fetal tissue relative to unwounded fetal controls or wounded adult skin. Thus both HOXB13 and PRX-2 are expressed in patterns consistent with roles in fetal skin development and cutaneous regeneration.

Epidermal integrin expression is upregulated rapidly in human fetal wound repair.

BACKGROUND/PURPOSE: The fetus heals skin wounds rapidly and scarlessly. The mechanisms that mediate the rapid reepithelialization that is seen in this process are unknown. Integrins are a family of cell surface receptors that bind fibronectin, tenascin, collagen, and other extracellular matrix proteins that are deposited rapidly in fetal wounds. The authors hypothesized that epidermal integrin receptors specific for fibronectin and other wound matrix proteins are upregulated rapidly during human fetal repair. METHODS: To investigate the spatial and temporal expression of integrins in scarless fetal repair, fetal skin from six human abortuses (16 to 23 weeks' gestation) was transplanted subcutaneously into severe combined immunodeficient mice. After graft take, full-thickness incisional wounds were made in the grafts, and grafts were harvested at various time-points from 4 hours to 28 days after wounding. Integrin receptor protein expression was analyzed at each time-point using immunohistochemistry with monoclonal antibodies specific for the receptors that bind fibronectin, tenascin, collagen, and laminin (alpha5, alpha(v), beta6, alpha2, alpha3, alpha6, and beta4). RESULTS: In this model, wounded human fetal skin grafts reepithelialized rapidly (within 24 to 36 hours) and healed scarlessly. Within 4 hours of wounding, the grafts showed increased, suprabasal expression (alpha2, alpha3, alpha6, beta4) or neoexpression (alpha5, alpha(b), beta6) of integrins at the epidermal wound edge. This increased expression persisted until reepithelialization was complete. CONCLUSIONS: Early upregulation of integrins in fetal wounds may permit rapid keratinocyte migration and reepithelialization, and may be important in limiting the induction of inflammatory mediators and scar.

A new in vivo model for the study of fetal wound healing.

We have developed a new in vivo model for the study of fetal wound healing. Fetal ICR mice (total gestation, 21 days) received a full-thickness incisional wound in the hind limb at gestational day 14 (N = 100). The wound was made with a 28.5-gauge needle that was passed transplacentally into the amniotic cavity. The wounds were analyzed histologically on postoperative days 0, 1, 3, and 5 by hematoxylin-eosin and Mallory's trichrome stains. Once the wounding technique was mastered, the overall mortality rate for this model was 20% by postwounding day 5. Each fetus healed their wound without scar by postwounding day 3. In 3 animals, 5 microliters of human transforming growth factor beta 1 (25 micrograms per microliter) was injected into the wound site, resulting in scar and an inflammatory cell infiltrate, indicating that the 14-day-gestation fetal mouse can be manipulated if necessary. This model offers the advantages of an in vivo system that can be studied at an early gestational age. Furthermore, it is inexpensive, easy to manipulate, and can be studied with commercially available murine probes.

Scar wars: implications of fetal wound healing for the pediatric burn patient.

Scar formation and fibrosis often cause devastating disabilities in children suffering severe burn injury. In contrast to the child, the fetus has the ability to heal skin injury without scar formation, and instead with regeneration of epithelial and mesenchymal tissues and restoration of normal skin architecture. In this paper we review those unique features of the fetus and fetal wound healing that may contribute to the scarless repair process. It is hoped that an understanding of these remarkable reparative capabilities may lead to the development of new wound healing therapies that reduce or prevent scar formation and fibrosis in the management of children with burns.

Fetoscopic gene therapy for congenital lung disease.

Fetal gene therapy offers the promise of cure for certain genetic diseases, like cystic fibrosis and surfactant protein B deficiency. The authors hypothesized that a fetoscopic approach could attain a high level of organ-specific gene transfer to the fetal lung late in gestation. To test this hypothesis the authors examined the efficacy, specificity, and toxicity of recombinant adenovirus-mediated transfer of the beta-galactosidase marker gene to the lung of late gestation fetal sheep using a fetoscopic technique. Twelve fetal sheep of 125 to 135 days' gestation (term, 145 days) underwent fetoscopic bronchoscopy and intratracheal administration of a replication-deficient adenoviral vector that transduces the beta-galactosidase marker gene. Escape of administered virus was prevented by the fetoscopic deployment of a detachable silicone balloon in the fetal trachea. All fetuses survived until being killed at 2 days after vector delivery for the histopathologic assessment of vector efficacy and specificity. Optimal beta-galactosidase transgene expression was observed at a viral titer of 2 x 10(12) particles per milliliter of administered volume. Expression was greatest in the distal pulmonary parenchyma, particularly in type II pneumocytes, and extended out to the pleura. There was no evidence of gene transfer in either the large conducting airways or in any other fetal organ. The authors have developed a minimally invasive technique for the specific pulmonary delivery of gene therapy vectors to the fetus with no associated acute toxicity. Gene transfer to the late gestation fetus for the treatment of congenital pulmonary disease may be feasible through fetoscopy.