A-43 Effects of Subthreshold Exercise on Post-concussive Symptom Endorsement and Cognition: A Pilot Randomized Clinical Trial

Purpose: The current study examined the effects of subthreshold exercise on symptom endorsement and neurocognitive functioning in adolescents with persisting concussion symptoms (>1 month). Methods: Sixteen participants (age M = 16.2, SD = 1.4) with persisting concussion symptoms were randomly assigned to control or subthreshold exercise intervention groups (Leddy et al., 2019). Participants engaged in concussion education before assignment to 6 weeks (3x weekly) of intervention: control (stretching) or subthreshold exercise. Both groups completed evaluations at baseline, midpoint, and follow-up, including a hybrid battery of assessments (yielding composites of processing speed and memory), a concussion symptom scale (PCS-R), and psychological inventories. Results: Both the intervention group and control group reported significant reduction in concussive symptom severity during the study period (PCS-R Change M = -21.29, SD = 13.54). Baseline endorsement of anxiety significantly differed across groups (p < 0.05); when controlling for anxiety, the intervention group demonstrated greater reduction in symptom endorsement compared to controls (F(1,13) = 7.30, p < 0.05, partial eta2 = 0.40). In contrast, after controlling for performance validity and the baseline anxiety difference, there was no significant difference (p > 0.05) in processing speed performance (partial eta2 = 0.14) or memory performance (partial eta2 = 0.11) by intervention group. Both groups remained generally intact normatively from the baseline to the follow-up evaluation across measures. Conclusions: Current results support the use of subthreshold exercise to reduce persisting symptoms of concussion post-acutely; additionally, results suggest that anxiety significantly impacted response to intervention. Lastly, there was no effect on cognitive indices by the intervention, suggesting that subthreshold exercise may have less impact on cognition than symptom endorsement in the post-acute phase of recovery.

NGF reprograms metastatic melanoma to a bipotent glial-melanocyte neural crest-like precursor

Melanoma pathogenesis from normal neural crest-derived melanocytes is often fatal due to aggressive cell invasion throughout the body. The identification of signals that reprogram de-differentiated, metastatic melanoma cells to a less aggressive and stable phenotype would provide a novel strategy to limit disease progression. In this study, we identify and test the function of developmental signals within the chick embryonic neural crest microenvironment to reprogram and sustain the transition of human metastatic melanoma to a neural crest cell-like phenotype. Results reveal that co-culture of the highly aggressive and metastatic human melanoma cell line C8161 upregulate a marker of melanosome formation (Mart-1) in the presence of embryonic day 3.5 chick trunk dorsal root ganglia. We identify nerve growth factor (NGF) as the signal within this tissue driving Mart-1 re-expression and show that NGF receptors trkA and p75 cooperate to induce Mart-1 re-expression. Furthermore, Mart-1 expressing C8161 cells acquire a gene signature of poorly aggressive C81-61 cells. These data suggest that targeting NGF signaling may yield a novel strategy to reprogram metastatic melanoma toward a benign cell type.

Summary: We identify and test the function of nerve growth factor to reprogram human metastatic melanoma cells to a less aggressive phenotype. This article has an associated First Person interview with the first author of the paper as part of the supplementary information.

DAN (NBL1) promotes collective neural crest migration by restraining uncontrolled invasion

Neural crest cells are both highly migratory and significant to vertebrate organogenesis. However, the signals that regulate neural crest cell migration remain unclear. In this study, we identify DAN as a novel factor that inhibits uncontrolled neural crest and metastatic melanoma invasion in a manner consistent with the inhibition of BMP signaling.

Neural crest cells are both highly migratory and significant to vertebrate organogenesis. However, the signals that regulate neural crest cell migration remain unclear. In this study, we test the function of differential screening-selected gene aberrant in neuroblastoma (DAN), a bone morphogenetic protein (BMP) antagonist we detected by analysis of the chick cranial mesoderm. Our analysis shows that, before neural crest cell exit from the hindbrain, DAN is expressed in the mesoderm, and then it becomes absent along cell migratory pathways. Cranial neural crest and metastatic melanoma cells avoid DAN protein stripes in vitro. Addition of DAN reduces the speed of migrating cells in vivo and in vitro, respectively. In vivo loss of function of DAN results in enhanced neural crest cell migration by increasing speed and directionality. Computer model simulations support the hypothesis that DAN restrains cell migration by regulating cell speed. Collectively, our results identify DAN as a novel factor that inhibits uncontrolled neural crest and metastatic melanoma invasion and promotes collective migration in a manner consistent with the inhibition of BMP signaling.

Dynamic interactions between cancer cells and the embryonic microenvironment regulate cell invasion and reveal EphB6 as a metastasis suppressor

Metastatic dissemination drives the high mortality associated with melanoma. However, difficulties in visualizing in vivo cell dynamics during metastatic invasion have limited our understanding of these cell behaviors. Recent evidence has revealed that melanoma cells exploit portions of their ancestral embryonic neural crest emigration program to facilitate invasion. What remains to be determined is how embryonic microenvironmental signals influence invasive melanoma cell behavior, and whether these signals are relevant to human disease. To address these questions, we interrogated the role of the neural crest microenvironment in dictating the spatiotemporal pattern of melanoma cell invasion in the chick embryo using 2-photon time-lapse microscopy. Results reveal that both permissive and inhibitory neural crest microenvironmental signals regulate the timing and direction of melanoma invasion to coincide with the neural crest migration pattern. These cues include bidirectional signaling mediated through the ephrin family of receptor tyrosine kinases. We demonstrate that EphB6 reexpression forces metastatic melanoma cells to deviate from the canonical migration pattern observed in the chick embryo transplant model. Furthermore, EphB6-expressing melanoma cells display significantly reduced metastatic potential in a chorioallantoic membrane (CAM) metastasis assay. These data on melanoma invasion in the embryonic neural crest and CAM microenvironments identify EphB6 as a metastasis suppressor in melanoma, likely acting at the stage of intravasation.

IMPLICATIONS

This article links cellular metastasis to behaviors observed in the ancestrally related embryonic neural crest and demonstrates the powerful influence of the embryonic microenvironment in regulating cell migratory behavior.

The neural crest and cancer: a developmental spin on melanoma

Neural crest (NC) cells undergo an epithelial to mesenchymal transition (EMT) in order to exit from the dorsal neural tube. Similarly, ancestrally related melanoma cells employ an EMT-like event during the initial stages of metastasis to dissociate from surrounding keratinocytes. Whether or not the molecular pathogenesis and cellular dynamics of melanoma metastasis resemble the embryonic NC invasion program is unclear. Here, we highlight advances in our understanding of tumor cell behaviors and plasticity, focusing on the relationship between melanoma and the NC invasion programs. We summarize recent discoveries of NC cell guidance and emerging in vivo imaging strategies that permit single cell resolution of fluorescently labeled tumor cells, with a focus on our recently developed in vivo chick embryo transplant model. Crucial to the molecular pathogenesis of metastasis, we highlight advances in gene profiling of small cell numbers, including our novel ability to gather gene expression information during distinct stages of melanoma invasion. Lastly, we present preliminary details of a comparison of specific genetic pathways associated with the early phases of melanoma invasion and known NC induction and migration signals. Our results suggest that malignant melanoma cells hijack portions of the NC program to promote plasticity and facilitate metastasis. In summary, there is considerable power in combining an in vivo model system with molecular analysis of gene expression, within the context of established developmental signaling pathways, to identify and study the molecular mechanisms of metastasis.

Gene profiling in the avian embryo using laser capture microdissection and RT-qPCR

The dynamic nature of the developing embryo makes it challenging to understand complex morphogenetic events using information from large-scale gene expression patterns. What would be more insightful is molecular profiling of small numbers of cells selectively surveyed at specific developmental stages. However, detecting gene expression profile information from small numbers of cells (<10) in homogenous tissue has remained a major challenge. Here, we describe the use of laser capture microdissection (LCM), immunohistochemistry (IHC), and RT-qPCR to extract gene profile information in distinct embryo tissue more precisely than is possible with any other method. We use the chick embryo model system and combine electroporation and dual-label IHC to specifically identify cells for harvest by LCM without significant degradation of total RNA. We describe the development of a pre-amplification protocol for small subpopulations of cells to produce sensitive RT-qPCR results. The gene-specific pre-amplification efficiently and linearly amplifies only gene transcripts of interest from the harvested material without the need for RNA isolation. By combining the above techniques with microfluidic RT-qPCR, we robustly analyze the expression of ∼300 genes from as few as 10 cells harvested by LCM. Together, this protocol presents a confident isolation and means of sensitive expression analysis of small cell numbers from tissues and overcomes a technical hurdle that limits gene profiling.

Melanoma revives an embryonic migration program to promote plasticity and invasion

Cancer cells must regulate plasticity and invasion to survive and metastasize. However, the identification of targetable mechanisms to inhibit metastasis has been slow. Signaling programs that drive stem and progenitor cells during normal development offer an inroad to discover mechanisms common to metastasis. Using a chick embryo transplant model, we have compared molecular signaling programs of melanoma and their embryonic progenitors, the neural crest. We report that malignant melanoma cells hijack portions of the embryonic neural crest invasion program. Genes associated with neural crest induction, delamination, and migration are dynamically regulated by melanoma cells exposed to an embryonic neural crest microenvironment. Specifically, we demonstrate that metastatic melanoma cells exploit neural crest-related receptor tyrosine kinases to increase plasticity and facilitate invasion while primary melanocytes may actively suppress these responses under the same microenvironmental conditions. We conclude that aberrant regulation of neural crest developmental genes promotes plasticity and invasiveness in malignant melanoma.

Abstract 3315: Malignant melanoma cells reciprocate aspects of the embryonic neural crest migration program to promote invasion and increased plasticity

Melanocytes derive from a highly invasive, multipotent embryonic cell population known as the neural crest. It has been proposed that this ancestral relationship predisposes melanocytes to having metastatic characteristics following neoplastic transformation to melanoma. In support of this hypothesis, we have previously shown that aggressive melanoma cells transplanted into the chick embryonic neural crest microenvironment respond to neural crest signaling mechanisms by emigrating along defined host neural crest pathways. To evaluate whether melanoma cells usurp aspects of the neural crest program typically silenced in differentiated melanocytes, we have employed the chick embryo transplant model coupled with laser capture microdissection to perform an in vivo molecular analysis of more than 70 neural-crest-related genes. Transplanted cells included c8161 aggressive melanoma cells, a poorly aggressive isogenic counterpart termed c81-61, and primary human melanocytes. We demonstrate that all three cell types express many neural-crest-related genes, but that aggressive cells aberrantly express some genes typically lost during melanocyte differentiation. Furthermore, the analysis revealed a significant increase in the ability of aggressive melanoma cells to respond to changing microenvironments by altering gene expression signatures, while transplanted melanocytes appeared to actively suppress these pathways. This increased responsiveness may be attributed to the dynamic regulation of Eph receptor tyrosine kinases and their cognate ephrin ligands, many of which were differentially expressed in aggressive melanoma cells versus poorly aggressive melanoma or primary melanocytes. Thus, metastatic melanoma cells usurp portions of the neural crest program to promote increased invasiveness and plasticity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3315. doi:1538-7445.AM2012-3315

Laryngotracheal reconstruction and cricotracheal resection in children: recent experience at Great Ormond Street Hospital

BACKGROUND

Surgery for paediatric airway stenosis is constantly evolving. Surgery is the primary treatment modality via either an open or endoscopic approach. The objective of this study was to review the results of laryngotracheal reconstruction (LTR) and cricotracheal resection (CTR) procedures performed at Great Ormond Street Hospital over the past 10 years.

METHODS

All patients who underwent open airway reconstruction surgery from January 2000 to December 2010 were included in this study. Patients treated entirely endoscopically were excluded. The data was collected using the electronic operating theatre database and the discharge summary database.

RESULTS

Complete data was available for 199 patients who underwent open airway reconstruction from January 2000 to December 2010. The procedures included single stage LTR (57, 28.6%), two stage LTR (115, 57.7%), single-stage stomal reconstruction (14), single-stage CTR (8) and two-stage CTR (5). The diagnoses at the initial airway endoscopy were laryngeal web (22), subglottic stenosis (151), posterior glottic stenosis (9), suprastomal collapse (15), supraglottic stenosis (1) and tracheal stenosis (1). For those with subglottic stenosis, the stenosis was grade 1 in 1 patient, grade 2 in 26 patients, grade 3 in 117 patients and grade 4 in 6 patients. At the completion of intervention 175/199 (87.9%) patients reported improvement in their symptoms. Amongst the subglottic stenosis group, post LTR success was achieved in 100% with grade 1 stenosis, 92.3% with grade 2 stenosis, 88.1% in grade 3 stenosis and 83.3% in grade 4 stenosis. Of the two-stage LTR procedures, 100/115 (86.9%) had their tracheostomy removed and 15/115 (13.1%) have failed decannulation. Of the single-stage LTR group, 50/57 (87.7%) patients were better both on airway examination and symptomatically postoperatively. Of the single-stage stomal reconstruction group, 13/14 (92.8%) were better symptomatically and on airway examination. Patients who underwent single-stage CTR had a better airway on examination and were symptomatically improved in all cases (8/8). For the patients who underwent two stage CTR, the tracheostomy was removed in 3/5 (60%) and retained in 2/5 (40%). For the whole group, 15/199 (7.5%) patients underwent a revision LTR. On further analysis, revision LTR was required in 4/57 (7.1%) single-stage LTR, 9/115 (7.8%) two-stage LTR, 1/5 (20%) two-stage CTR and 1/8 (12.5%) single-stage CTR. In this study complications occurred in 13/199 (6.5%).

CONCLUSIONS

Subglottic stenosis in children needs to be approached on the basis of the nature and severity of stenosis and the individual patient's general health. Good outcomes are achieved with both LTR and CTR. Good results are obtained both with single-stage and two-stage LTR, but restenosis remains a problem. An individual approach is required for treatment of paediatric airway stenosis to achieve good final outcomes. The overall success rate has increased only marginally in our institution over the last 20 years.

CycleTrak: a novel system for the semi-automated analysis of cell cycle dynamics

Cell proliferation is crucial to tissue growth and form during embryogenesis, yet dynamic tracking of cell cycle progression and cell position presents a challenging roadblock. We have developed a fluorescent cell cycle indicator and single cell analysis method, called CycleTrak, which allows for better spatiotemporal resolution and quantification of cell cycle phase and cell position than current methods. Our method was developed on the basis of the existing Fucci method. CycleTrak uses a single lentiviral vector that integrates mKO2-hCdt1 (30/120), and a nuclear-localized eGFP reporter. The single vector and nuclear localized fluorescence signals simplify delivery into cells and allow for rapid, automated cell tracking and cell cycle phase readout in single and subpopulations of cells. We validated CycleTrak performance in metastatic melanoma cells and identified novel cell cycle dynamics in vitro and in vivo after transplantation and 3D confocal time-lapse imaging in a living chick embryo.

New insights into cathepsin D in mammary tissue development and remodeling

Cathepsin D (CatD) is a lysosomal aspartyl endopeptidase originally considered a "house keeping enzyme" involved in the clearance of unwanted proteins. However, recent studies have revealed CatD's involvement in apoptosis and autophagy, thus signifying an important function in the proper development and maintenance of multi-cellular organs. In the mammary gland, matrix degradation and the remodeling process are orchestrated by proteolytic enzymes, but the role of CatD at distinct developmental stages has remained mostly unexplored. Based on our previous studies we sought to address the role of this endopeptidase in mammary gland development and remodeling. By employing a mouse model, we report a previously unidentified participation of CatD in different stages of mammary gland development. Our findings reveal that CatD undergoes distinct protein processing at different stages of mammary gland development, and this customized processing results in differential enzymatic activity (constitutive and low pH activatable) best fitting particular stage(s) of development. In addition, at the onset of involution the N-glycan structure of this endopeptidase switches from a mixed high mannose and hybrid structure to an almost exclusively high mannose type, but reverts back to the original N-glycan composition by day 4 of involution. Our findings illuminate (at least in part) the "raison d'être" for CatD's numerous and highly regulated proteolytic processing steps from the pro-form to the mature enzyme. In the mammary gland, specific cleavage product(s) perform specialized function(s) befitting each stage of remodeling. It is noteworthy that deregulated synthesis, secretion and glycosylation of CatD are hallmarks of cancer progression. Thus, identifying the role of CatD in a dynamic normal tissue undergoing highly regulated cycles of remodeling could provide valuable information illuminating the deregulation of CatD associated with cancer development and metastasis.

In ovo live imaging of avian embryos

Vertebrate development is best studied in an intact embryo model, but a robust interface between time-lapse microscopy and in vivo embryo health and maintenance can be difficult to achieve in model systems that rely on external factors for life support. This protocol presents a system for in ovo culture and time-lapse imaging of fluorescently labeled cells within living avian embryos, using a Teflon membrane that is oxygen-permeable and liquid-impermeable. The protocol describes the Teflon membrane assembly (the assembly size can be changed to fit smaller eggs, such as those of the quail), its interface with the egg window, and the use of an upright microscope and heated chamber. The use of the system is demonstrated in chick embryos by following individual fluorescently labeled neural crest cells, a multipotent stem cell-like population that differentiates into a wide range of derivatives and travels extensively throughout the embryo. By combining in ovo culture with confocal or two-photon four-dimensional time-lapse imaging, embryo health can be maintained for up to 5 d, and neural crest cell behaviors can be visualized for long periods of time (approximately 36 h). This technique has been adapted to study somitogenesis.

Cranial neural crest migration: new rules for an old road

The neural crest serve as an excellent model to better understand mechanisms of embryonic cell migration. Cell tracing studies have shown that cranial neural crest cells (CNCCs) emerge from the dorsal neural tube in a rostrocaudal manner and are spatially distributed along stereotypical, long distance migratory routes to precise targets in the head and branchial arches. Although the CNCC migratory pattern is a beautifully choreographed and programmed invasion, the underlying orchestration of molecular events is not well known. For example, it is still unclear how single CNCCs react to signals that direct their choice of direction and how groups of CNCCs coordinate their interactions to arrive at a target in an ordered manner. In this review, we discuss recent cellular and molecular discoveries of the CNCC migratory pattern. We focus on events from the time when CNCCs encounter the tissue adjacent to the neural tube and their travel through different microenvironments and into the branchial arches. We describe the patterning of discrete cell migratory streams that emerge from the hindbrain, rhombomere (r) segments r1-r7, and the signals that coordinate directed migration. We propose a model that attempts to unify many complex events that establish the CNCC migratory pattern, and based on this model we integrate information between cranial and trunk neural crest development.

Abstract 5163: Does melanoma metastasis recapitulate an embryonic neural crest invasion program

Melanocytes derive from a highly invasive and pluripotent embryonic cell population called the neural crest. It has been proposed that melanocytes might be inherently predisposed to having invasive and metastatic attributes following neoplastic transformation as a result of their embryonic differentiation program. Metastatic melanoma cells are highly invasive and typically exhibit a high degree of plasticity, similar to their neural crest progenitors, but whether these cells recapitulate an embryonic invasion program related to their ancestral neural crest is unclear. We have shown that metastatic melanoma cells transplanted into the chick embryonic neural crest microenvironment invade into the host tissue, migrate along host neural crest cell migratory pathways, do not reform tumors, and can potentially be reprogrammed to a neural-crest-cell-like phenotype (Kulesa et al., 2006; Hendrix et al., 2007; Kasemeier-Kulesa et al., 2008). Here, we use the chick embryo neural crest microenvironment, combined with 2-photon photoactivation cell labeling and time-lapse microscopy, as a model to address the predisposition hypothesis in more detail. We find that melanoma cell orientation to the host cranial neural crest migratory routes and ellipticity of cell shape increase as cells stream out in distinct strand-like structures. Strand-like structures extend into the neural crest microenvironment, but give rise to individually invasive cells away from the neural tube. 2-photon photoactivation of PSCFP2, to discretely label small numbers of melanoma cells in ovo, reveals that the most invasive cells do not start at the tissue transplant periphery but may come from deep within the transplant. In vivo 2-photon time-lapse imaging confirms the unpredictable nature of melanoma dissemination and that some cells are more aggressively predisposed. These results indicate that melanoma metastasis resembles the neural crest migratory pattern but is unpredictable in the spatio-temporal order of invasion. We propose that the chick embryo transplant model is a valid, in vivo model of melanoma metastastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5163.

Temporal and spatial expression patterns for the tumor suppressor Maspin and its binding partner interferon regulatory factor 6 during breast development

Interferon regulatory factor 6 (IRF6) is a non-canonical member of the interferon regulatory factor family of transcription factors. We recently identified IRF6 as a novel Maspin-interacting protein in mammary epithelial cells. Maspin is a tumor suppressor in the breast and has also been implicated in mammary gland morphogenesis. To explore a possible role for IRF6 in conjunction with Maspin during mammary gland growth and differentiation, we examined the expression of IRF6 and Maspin during post-utero mammary gland development using a combination of in vitro and in vivo approaches. The data revealed that the expression of IRF6 and Maspin is temporally and spatially regulated throughout mammary gland development, with maximal expression of both proteins occurring in fully differentiated, lactating lobuloalveolar cells. We further show that IRF6 adopts a lumenal localization pattern following complete epithelial cell polarization and present new evidence for the secretion of IRF6 into the milk. These results support the hypothesis that IRF6 and Maspin are important for mammary epithelial cell differentiation, and advance our understanding of the Maspin-IRF6 partnership during normal mammary gland development.

IFN-gamma regulation of vacuolar pH, cathepsin D processing and autophagy in mammary epithelial cells

In this study we examined the ability of interferon-gamma (IFN-gamma) to regulate mammary epithelial cell growth and gene expression, with particular emphasis on two genes: Maspin (a member of serine protease inhibitor superfamily), and the lysosomal aspartyl endopeptidase cathepsin D (CatD). The protein products of these genes are critically involved in regulation of multitude of biological functions in different stages of mammary tissue development and remodeling. In addition, the expression of Maspin is down-regulated in primary breast cancer and is lost in metastatic disease, while CatD is excessively produced and aberrantly secreted by breast cancer cells. We report that IFN-gamma receptors are expressed in mammary epithelial cells, and receptor engagement by IFN-gamma transduces the IFN-gamma signal via Stat-1 resulting in decreased vacuolar pH. This change in vacuolar pH alters CatD protein processing and secretion concurrent with increased Maspin secretion. In addition, IFN-gamma exerts a suppressive effect on cell growth and proliferation, and induces morphological changes in mammary epithelial cells. Our studies also reveal that breast cancer cells, which are devoid of Maspin, are refractory to IFN-gamma with respect to changes in vacuolar pH and CatD. However, Maspin transfection of breast cancer cells partially sensitizes the cells to IFN-gamma's effect, thus providing new therapeutic implications.

Chronic suppurative otitis media following paediatric cochlear implantation

The objective of this study was to report and discuss the management of chronic suppurative otitis media (CSOM) following cochlear implantation in children. The study was a retrospective review of 650 patients receiving an implant at two paediatric tertiary referral centres for cochlear implantation. Nine patients were identified who developed CSOM following cochlear implantation (incidence 1.38%). The mean time interval between implantation and symptom development was 3.66 years (range 2-8 years) and the mean time interval between implantation and CSOM surgery was 5.02 years (range 2.2-8 years). All patients presented with otorrhoea and/or abscess formation over the implant site. Two patients underwent a modified radical mastoidectomy and seven underwent a combined approach tympanoplasty, three of whom required posterior canal wall reconstruction with cortical bone and one with cartilage. In four cases it was possible to remove the cholesteatoma without removing the implant. All but two patients were fitted with a contralateral implant. In the explanted ears the cochlear implant electrode was cut at the cochleostomy site, which was then covered with muscle. Chronic suppurative otitis media following cochlear implantation may occur either as a result of a posterior canal wall defect related to surgery or possibly de novo. Attempts should be made to save the implant, but explantation with reimplantation of the contralateral ear may be the only option. In these cases the intracochlear part of the electrode array should be left in situ to facilitate possible future reimplantation. Surgical options for management of CSOM should be individualized and may include both canal-wall up and canal-wall down techniques. To reduce the incidence of CSOM following implantation the authors recommend: (1) prompt treatment and careful follow-up of patients with a history of otitis media with effusion, (2) avoidance of excessive thinning of the posterior canal wall during mastoidectomy and (3) reconstruction of any accidental trauma to the annulus or posterior canal wall during posterior tympanotomy.

IRF6 in development and disease: a mediator of quiescence and differentiation

Post utero development of the mammary gland is a complex developmental process characterized by states of rapid cell proliferation (branching morphogenesis) followed by functional differentiation (lactation) and the consequent apoptosis (involution) of the secretory mammary epithelial cell. This process is cyclical, such that involution returns the mammary gland to a near-virgin-like state capable of responding to morphogenic cues with each consecutive pregnancy. Importantly, many of the regulatory processes which oversee mammary gland development are corrupted or otherwise compromised during the development of breast cancer. For example, Interferon Regulatory Factor 6 (IRF6) is a novel protein with growth inhibitory properties that was initially identified in mammary epithelial cells through its interaction with maspin, a known tumor suppressor in normal breast tissue. Recent findings from our laboratory suggest that IRF6 functions synergistically with maspin to regulate mammary epithelial cell differentiation by acting on the cell cycle. This perspective focuses on the possible involvement of IRF6 in promoting differentiation by regulating exit from the cell cycle and entry into the G(0) phase of cellular quiescence, and how these new findings shed light on normal mammary gland development and the initiation and progression of breast cancer.

The epigenetic influence of tumor and embryonic microenvironments: how different are they?

The microenvironment is being increasingly recognized as a critical component in tumor progression and metastases. As such, the bi-directional signaling of extracellular mediators that promote tumor growth within the microenvironment is a focus of intense scrutiny. Interestingly, there are striking similarities between the phenotypes of aggressive tumor and embryonic stem cells, particularly with respect to specific signaling pathways underlying their intriguing plasticity. Here, we demonstrate the epigenetic influence of the hESC microenvironment on the reprogramming of aggressive melanoma cells using an innovative 3-D model. Specifically, our laboratory has previously demonstrated the redifferentiation of these melanoma cells to a more melanocyte-like phenotype (Postovit et al., Stem Cells 24(3):501–505, 2006), and now we show the loss of VE-Cadherin expression (indicative of a plastic vasculogenic phenotype) and the loss of Nodal expression (a plasticity stem cell marker) in tumor cells exposed to the hESC microenvironment. Further studies with the 3-D culture model revealed the epigenetic influence of aggressive melanoma cells on hESCs resulting in the down-regulation of plasticity markers and the emergence of phenotype-specific genes. Additional studies with the aggressive melanoma conditioned matrix microenvironment demonstrated the transdifferentiation of normal melanocytes into melanoma-like cells exhibiting a vasculogenic phenotype. Collectively, these studies have advanced our understanding of the epigenetic influence associated with the microenvironments of hESCs and aggressive melanoma cells, and shed new light on their therapeutic implications. Moreover, we have a better appreciation of the convergence of embryonic and tumorigenic signaling pathways that might stimulate further consideration of targeting Nodal in aggressive tumor cells resulting in a down-regulation of tumorigenic potential and plasticity.

Treatment of piriform fossa sinuses with monopolar diathermy

Introduction:

Embryological remnants of third or fourth branchial pouches are a rare but important cause of recurrent neck abscesses in children. They are characterised by an internal opening in the piriform fossa. Traditional management involves surgical excision of the entire tract. We present our experience with the use of monopolar diathermy applied to the internal sinus opening as a treatment modality for this condition.

Materials and methods:

A retrospective, case report review was performed.

Results:

Four cases of piriform fossa sinus were treated with monopolar diathermy to the sinus opening via an endoscopic approach. The first three cases were treated in this way for recurrence, following external tract excision, while the fourth case had simultaneous excision of the tract and diathermy to the piriform fossa opening. There were no serious complications and no recurrence within a follow-up period ranging from nine to 27 months.

Discussion:

Obliteration of the internal opening of these sinuses by endoscopic diathermy is a safe and effective management option for this condition, either as an alternative to or as an adjunct to external surgical excision of the tract.

The Great Ormond Street Hospital paediatric cochlear implant programme 1992-2004. A review of surgical complications

The authors present a review of surgical complications following cochlear implantation at Great Ormond Street Hospital, since inception of the programme in 1992 until June 2004. Complications are defined as major (resulting in re-operation, explantation, re-implantation or which resulted in permanent serious morbidity or mortality) or minor (where the implant was not threatened). A comparison of surgical complication rates is made both with an earlier study in the same institution and also with other cochlear implantation centres worldwide. The decrease in surgical complication rates is discussed along with the difficulties inherent in cochlear implantation in the paediatric population with coexisting medical complaints.

Updated surgical experience with bone-anchored hearing aids in children

BACKGROUND

We present the results of a retrospective review of children undergoing implantation with bone-anchored hearing aids (BAHAs) at the Great Ormond Street Hospital for Children.

METHODS

The case notes of 71 children undergoing BAHA placement at the Great Ormond Street Hospital for Children between December 1990 and August 2002 were reviewed. Outcome measures included hearing thresholds, incidence of fixture loss, skin reaction and need for revision. Quality of life outcomes were also measured.

RESULTS

Eighty-five ears had been implanted. Fifty-four per cent of children had experienced no complications, 42 per cent had required revision surgery and 26 per cent had experienced fixture loss at some point. Young age at implantation was associated with an adverse outcome. Trauma and failure of osseointegration had been the commonest reasons for failure. A skin reaction around the abutment had occurred at some point in 37 per cent of children but had persisted for longer than six months in only 9 per cent; this had been associated with fixture loss. The use of fixture site split skin grafts had reduced problems with skin hypertrophy and hair overgrowth. Hearing thresholds when using BAHAs had been comparable to those when using bone conduction hearing aids. However, BAHAs had significant additional benefits in terms of sound quality, ease of use and overall quality of life.

CONCLUSION

Bone-anchored hearing aids provide significant benefits over other types of hearing aid, both audiologically and in terms of quality of life. Careful selection of candidates and meticulous follow up are required in order to minimize complications.

Subglottic haemangioma in children: experience with open surgical excision

Subglottic haemangioma is a potentially life-threatening condition for which various treatment modalities are available. The objective of this study was to evaluate our results for open excision of subglottic haemangioma. The study assessed 18 patients who had been treated at a paediatric tertiary referral centre. Most of these patients (83.3 per cent) had undergone open surgical excision without post-operative tracheostomy and had been intubated for several days post-operatively (single-stage procedure). In most of these patients (66.7 per cent), an anterior cartilage graft had been used for reconstruction. The average follow up in this study was 25 months. All the patients in this series had achieved an adequate airway after the procedure. One patient had developed a recurrence of haemangioma in the trachea at a later date. The results of open surgical excision in this study were very encouraging. Seventeen out of 18 (94.4 per cent) patients had avoided tracheostomy or had been decannulated as a direct result of surgery. One of these 18 patients (5.6 per cent) had required a temporary post-operative tracheostomy for 13 months as the subglottis cleared; this was classed as a partial success. Our experience is that open excision is a highly successful ‘one stop’ treatment for subglottic haemangioma, which avoids prolonged use of steroids and multiple endoscopic procedures. No patient in this series developed subglottic stenosis, which can be a significant complication of laser application.

Third and fourth branchial pouch anomalies

Congenital sinuses arising from the pyriform fossae are rare. They may present as neck cysts, recurrent neck abscesses, thyroiditis or neonatal stridor. Children typically undergo multiple surgical procedures before the diagnosis is made.

We present our recent experience of five third-pouch sinuses and four fourth-pouch sinuses, including one bilateral case. The median age at presentation was four years. The mean number of operations prior to diagnosis was six (range 0-13), with a mean delay to diagnosis of six years. The diagnosis was made by barium swallow, by ultrasound, at pharyngoscopy or at open surgery. The median age at definitive surgery was 10 years. Definitive treatment involved complete excision of the sinus and neck mass in seven cases. Two sinuses were treated with endoscopicdiathermy to their internal opening.

Adoption of the correct nomenclature, diagnostic tools and operative requirements for these cases will help reduce the significant morbidity.

The midfacial degloving approach to sinonasal tumours in children

The midfacial degloving approach was originally described by Denker and Kahler in 1926 but has been little used in the paediatric population. The procedure allows access to benign and malignant lesions of the sinonasal region with the avoidance of an external scar. The advantages and application of this technique are presented in 9 paediatric patients, ranging from 3 months to 15 years of age with a mean follow-up of 7 months. Eight children had benign pathology. There were two juvenile angiofibromas, two nasal gliomas, one ossifying fibroma, one fibroma, one fibrous dysplasia and one benign myofibroblastic proliferation. One child had malignant disease in the form of recurrent embryonal rhabdomyosarcoma. All had excellent cosmetic results and no complications were encountered during follow-up.

Biological functions of maspin

Maspin (Mammary Serine Protease Inhibitor) was first reported in 1994 as a serpin with tumor suppressive properties. Maspin was initially isolated through subtractive hybridization and differential display analysis as a 42-kDa protein that is expressed in normal mammary epithelial cells but reduced or absent in breast carcinomas (Zou et al., 1994). Further research led to maspin's characterization as a class II tumor suppressor based on its ability to inhibit cell invasion, promote apoptosis, and inhibit angiogenesis (Sheng et al., 1996; Zhang et al., 2000b; Jiang et al., 2002). Since then, efforts have been made to characterize maspin's tumor suppressive mechanisms. In particular, researchers have studied maspin localization, the regulation of maspin expression, and more recently, maspin protein interactions. By elucidating these mechanisms, researchers are beginning to understand the complex, pleiotropic nature of maspin and the pathways through which maspin exerts its tumor suppressive properties. These new findings not only further enhance our understanding of cancer biology but also provide an avenue to develop maspin's potential as a diagnostic marker for cancer progression, and as a potentially powerful therapeutic agent in the fight against breast cancer.

How we do it: BAHA positioning in patients with microtia requiring auricular reconstruction

Keypoints * Bilateral microtia is a challenging problem as these patients require both reconstruction of the auricle and rehabilitation of hearing. * Our aim was to find the optimal position for bone-anchored hearing aids (BAHA) in patients requiring reconstruction of the auricle on the same side. * From an analysis of five such operated patients, it was found that siting a BAHA 6.5-7.0 cm from the position of the external auditory meatus is probably the correct distance to facilitate optimal auricular reconstruction. * Using these criteria, a group of another five patients with BAHA awaiting auricular reconstruction were reviewed. Of these only three (60%) have been satisfactorily sited.

Mammary serine protease inhibitor (Maspin) binds directly to interferon regulatory factor 6: identification of a novel serpin partnership

Since its reported discovery in 1994, maspin (mammary serine protease inhibitor) has been characterized as a class II tumor suppressor by its ability to promote apoptosis and inhibit cell invasion. Maspin is highly expressed in normal mammary epithelial cells but reduced or absent in aggressive breast carcinomas. However, despite efforts to characterize the mechanism(s) by which maspin functions as a tumor suppressor, its molecular characterization has remained somewhat elusive. Therefore, in an attempt to identify maspin-interacting proteins and thereby gain insight into the functional pathways of maspin, we employed a maspin-baited yeast two-hybrid system and subsequently identified Interferon Regulatory Factor 6 (IRF6) as a maspin-binding protein. IRF6 belongs to the IRF family of transcription factors, which is best known for its regulation of interferon and interferon-inducible genes following a pathogenic stimulus. Although many of the IRF family members have been well characterized, IRF6 remains poorly understood. We report that IRF6 is expressed in normal mammary epithelial cells and that it directly associates with maspin in a yeast two-hybrid system and in vitro. The interaction occurs via the conserved IRF protein association domain and is regulated by phosphorylation of IRF6. We have shown that, similar to maspin, IRF6 expression is inversely correlated with breast cancer invasiveness. We further demonstrated that the transient re-expression of IRF6 in breast cancer cells results in an increase of N-cadherin and a redistribution of vimentin commensurate with changes in cell morphology, suggestive of an epithelial-to-mesenchymal transition event. Concomitantly, we showed that maspin acts as a negative regulator of this process. These findings help to elucidate the molecular mechanisms of maspin and suggest an interactive role between maspin and IRF6 in regulating cellular phenotype, the loss of which can lead to neoplastic transformation.

Laryngeal ultrasound to assess vocal fold paralysis in children

The purpose of this study was to assess the practicality and validity of laryngeal ultrasound to establish vocal fold movement in children with suspected vocal fold palsy. Fifty-five consecutive patients (age range three days to 12 years) with suspected vocal fold palsy underwent both laryngoscopy and laryngeal ultrasound. Ultrasonographic findings correlated with endoscopic findings in 81.2 per cent of cases. This, however, rose to a concordance rate of 89.5 per cent in patients aged over 12 months. Laryngeal ultrasound is well-tolerated, safe and non-invasive and the authors feel that it is a useful adjunct to endoscopy in the diagnosis of vocal fold palsy.

An update on choanal atresia surgery at Great Ormond Street Hospital for Children: preliminary results with Mitomycin C and the KTP laser

We present the results of transnasal choanal atresia correction in 46 children, as an update to the published Great Ormond Street Hospital series. Females outnumbered males 2-1, and half the cases in our series were bilateral. Eight of the children with bilateral atresia had the CHARGE association. The median number of procedures required was three over a period of up to 3 years. Eighty-two percent of children with unilateral atresia and 78% of those with bilateral atresia were asymptomatic at the time of their last follow up. Four deaths occurred, all but one in children with CHARGE association. We were not able to demonstrate any benefit from the use of Mitomycin C, the KTP laser, betamethasone nasal drops or (in unilateral cases) stents.

Type IV laryngotracheoesophageal clefts -- recent 5 year experience at Great Ormond Street Hospital for Children

This article summarises a 5 year experience of type IV laryngotracheoesophageal clefts from Great Ormond Street Hospital for Children, London. We present six infants who had type IV clefts, two of whom are long-term survivors, and we review the literature. The recognition of specific complicating issues may lead to a standardised approach, which can result in successful repair and long-term survival. Increased awareness of the condition and early diagnosis combined with aggressive, planned surgical intervention in centres of paediatric expertise should result in a significant reduction of current mortality.

Aryepiglottoplasty for laryngomalacia: 100 consecutive cases

A retrospective review of the notes of 100 consecutive patients who had undergone aryepiglottoplasty for laryngomalacia, at Great Ormond Street Hospital for Children, was undertaken. Fifty-six were male, 44 female and 47 were under three months of age. Indications for surgery were oxygen desaturation below 92 per cent and feeding difficulties causing failure to thrive. Forty-seven patients had other pathology contributing to their airway compromise or feeding problems. Improvement in stridor after one month was achieved in 86/91 (94.5 per cent) being abolished completely in 50/91 (55 per cent). Of the 25 per cent of patients whose symptoms took more than one week to resolve, 16/22 (63.6 per cent) were later found to have a serious neurological condition. Feeding was improved in 42 of 58 patients (72.4 per cent) who had a pre-operative feeding difficulty. The complication rate was low, with only five out of 86 (10 per cent) experiencing initial worsening of the airway and six per cent having aspiration of early feeds before improvement occurred. Endoscopic aryepiglottoplasty remains the operation of choice for patients with severe laryngomalacia, however, in the presence of neurological disease surgery is less likely to be successful.

Management and outcome of choanal atresia correction

OBJECTIVES

Outcome analyses of factors that may either maximize success or predict a better outcome following choanal atresia correction.

METHODS

A retrospective review of children undergoing choanal atresia correction at Great Ormond Street Hospital for Children, London between January 1990 and April 1998. Children with unilateral or bilateral choanal atresia were studied. In all cases, correction was by a transnasal approach under endoscopic control. A 120 degrees Hopkins rod telescope was used to visualize the atretic plate from the nasopharynx. Straight urethral sounds were used to perforate the plate followed by use of an air drill to remove the bony component. Portex endotracheal tubes were subsequently inserted as nasal stents.

RESULTS

Sixty-five children (19 M, 46 F: age range 1 day to 17 years) presented with choanal atresia and the outcomes for 46 were included in the study. Twenty-six patients (40%) had other major anomalies. In children with unilateral atresia neither duration of stenting nor presence of facial anomalies had an impact on outcome. Of those children with bilateral choanal atresia and associated facial anomalies (n=9), 56% were asymptomatic following correction. In children with isolated bilateral choanal atresia (n=19), 74% were asymptomatic following correction; 29% (n2.3 kg (n3. 5 mm (n=6) had an 83% chance of a good outcome. Those patients stented with a tube </=3.5 mm (n=22) had only a 64% success rate. None of the patients who were stented for at least 12 weeks remained symptomatic.

CONCLUSIONS

Neonates with bilateral choanal atresia who were stented for at least 12 weeks with the largest Portex tube that comfortably passed through the anterior nares had the best outcome. If they had either associated anomalies or low weight at surgery, they were less likely to become asymptomatic. For patients with unilateral choanal atresia, neither the presence of facial anomalies nor stent duration had an impact on outcome.

Investigation and treatment of thyroglossal cysts in children

Thyroglossal cysts are the commonest midline neck masses in children. To evaluate current practice questionnaires were sent to all ear, nose and throat (ENT) and paediatric surgeons in the UK and 72% responded. The commonest investigation requested was an ultrasound scan (54%) and the commonest operation was a variant of Sistrunk's procedure (78%). Paediatric surgeons did fewer investigations than ENT surgeons and tended to excise more of the thyroglossal tract. Review of the published work suggests that ultrasound scanning and Sistrunk's procedure are the best management policy. The scan can avoid inadvertent excision of an ectopic thyroid gland. Extensive thyroglossal tract excisions give lower recurrence rates.

Laparostomy for severe intra-abdominal infection complicating colorectal disease

PURPOSE

The aim of this study was to evaluate the use of laparostomy in the management of patients with severe intra-abdominal infection resulting from colorectal disease.

METHODS

Seven patients, four with inflammatory bowel disease, two with colorectal carcinoma, and one with diverticular perforation, underwent laparostomy during a six-year period for postoperative, severe, intra-abdominal infection.

RESULTS

The median age was 42 years, the mean Acute Physiology and Chronic Health Evaluation II score was 22.7, and the observed mortality was 28.6 percent (2/7 patients). In one patient the laparostomy was closed at 11 days; in all the others the wound was left to heal by granulation and contraction, and two of these later required reconstructive surgery. The median follow-up was three years and seven months.

CONCLUSION

Laparostomy is an effective and practical method of managing patients with severe intra-abdominal infection as a result of colorectal disease.

Pediatric vocal fold paralysis: a long-term retrospective study

OBJECTIVE

To review our experience of pediatric vocal fold paralysis (VFP), with particular emphasis on etiological factors, associated airway pathologic conditions, and treatment and prognostic outcomes.

DESIGN

Retrospective case review of a cohort of patients presenting with VFP.

SETTING

Tertiary referral center.

PATIENTS

A consecutive sample of 102 patients presenting with VFP to Great Ormond Street Hospital for Children, London, England, over a 14-year period from 1980 to 1994.

RESULTS

There was an almost equal distribution of unilateral (52% [n = 53]) and bilateral (48% [n = 49]) VFP. Iatrogenic causes (43% [n = 44]) formed the largest group, followed by idiopathic VFP (35% [n = 36]), neurological causes (16% [n = 16]), and finally birth trauma (5% [n = 5]). Associated upper airway pathologic conditions were noted in 66% (n = 23) of patients who underwent tracheotomy. Tracheotomy was necessary in only 57% (n = 28) of children with bilateral VFP. Prognosis was variable depending upon the cause, with neurological VFP having the highest rate of recovery (71% [5/7]) and iatrogenic VFP the lowest rate (46% [12/26]).

CONCLUSION

Recovery after an interval of up to 11 years was seen in idiopathic bilateral VFP; this has significant implications when considering lateralization procedures in these patients.

An inquiry-based teaching tool for understanding arterial blood pressure regulation and cardiovascular function

Educators are placing a greater emphasis on the development of cooperative laboratory experiences that supplement the traditional lecture format. The new laboratory materials should encourage active learning, problem-solving, and inquiry-based approaches. To address these goals, we developed a laboratory exercise designed to introduce students to the hemodynamic variables (heart rate, stroke volume, total peripheral resistance, and compliance) that alter arterial pressure. For this experience, students are presented with "unknown" chart recordings illustrating pulsatile arterial pressure before and in response to several interventions. Students must analyze and interpret these unknown recordings and match each recording with the appropriate intervention. These active learning procedures help students understand and apply basic science concepts in a challenging and interactive format. Furthermore, laboratory experiences may enhance the students' level of understanding and ability to synthesize and apply information. In conducting this exercise, students are introduced to the joys and excitement of inquiry-based learning through experimentation.

Late Cenozoic Reverse Faulting in the Fall Zone, Southeastern Virginia

A set of en-echelon reverse faults cut Paleozoic metamorphosed igneous rocks of the Piedmont and overlying late Cenozoic sediments at the Old Hickory Heavy Mineral Deposit in the Fall Zone of southeastern Virginia. Diorite of the eastern Slate Belt was faulted over nearshore to shore-face deposits of the Pliocene Yorktown Formation. These NW-SE-striking faults experienced oblique dip-slip movement with a maximum displacement of up to 6 m on individual faults. Faults tip out along strike and are overlain by distinct cobble beds, suggesting that sediment deposition and faulting were contemporaneous. Deformation at Old Hickory may have been formed by reactivation of existing Paleozoic structures under a regionally extensive compressional stress field parallel to the modern one.

Prenatal care for low-income women enrolled in a managed-care organization

OBJECTIVE

To determine barriers to prenatal care among managed-care enrollees who receive Medicaid.

METHODS

In-person interviews were conducted with women 13-45 years old who were members of the Prudential HealthCare Community Plan in Memphis, Tennessee. Interview data were linked to medical chart reviews for 200 women who were currently pregnant or had delivered a baby since enrollment in Prudential. Factors related to untimely entry to prenatal care and inadequate prenatal visits were examined.

RESULTS

More than half of the respondents had either untimely entry to or inadequate prenatal care. Overall, 89% of respondents had favorable attitudes about prenatal care. Several system and personal factors were associated with receipt of early or adequate prenatal care. Multivariate analysis showed that one system and two personal factors remained significantly related to entry to prenatal care. Women who entered Prudential during pregnancy were 2.4 times more likely (95% CI 1.1, 5.0) to receive late care than women who enrolled before pregnancy. Women who felt too tired to go for care were 2.2 times more likely (95% CI 1.0, 4.9) to receive late care. Women who experienced physical violence during pregnancy were 3.5 times more likely (95% CI 1.0, 12.0) to receive late care. Multivariate analysis with adequacy of prenatal care as the outcome showed several personal factors that increased odds of receiving inadequate prenatal care; however, only help from the infant's father was significantly related to adequacy of prenatal care. Women who did not have much help from the infant's father were 1.9 times more likely not to have adequate care (95% CI 1.0, 3.6).

CONCLUSION

Even when affordable care was available, many low-income women did not avail themselves of it. Although women knew the importance of prenatal care, there was a gap between attitudes and actually seeking appropriate care. System and personal factors need to be addressed to overcome barriers to prenatal care.

Educational puzzles for understanding gastrointestinal physiology

We developed four innovative, creative, and fun educational tools to promote active learning, enhance problem-solving skills, and encourage small group discussion. Furthermore, the tools encourage deductive reasoning and critical thinking rather than passive memorization of material. The tools include crossword puzzles, hidden messages, word scrambles, and word searches. These tools were developed using two computer programs: the Crossword Construction Kit and The New Puzzle Factory. Instructors are encouraged to optimize the value of the tools by using the additional options presented at the end of each of the puzzles. The additional options encourage students to become active learners by creating their own tools. Although the principles of these four tools can be adapted to many disciplines, these specific games focused on gastrointestinal physiology. Our goal was to create tools that can be used either inside or outside the classroom to complement and enhance the lecture.

"Virtual rat": a tool for understanding hormonal regulation of gastrointestinal function

This manuscript describes a "dry laboratory" using the "virtual rat" to help students understand the hormonal regulation of gastrointestinal function. The laboratory was modeled after a recent exercise that used the virtual rat to teach basic endocrine physiology. The virtual rat concept avoids the many obstacles associated with animal experimentation (for example, lack of adequate animal facilities, expense, equipment, and limited teacher experience). Our goal was to create a fun and educational experience while avoiding the complications associated with laboratory experimentation. No additional materials are required to complete this exercise. After finishing this laboratory, the students should have a greater understanding and appreciation for experimental design and the collection, analysis, and interpretation of data.

Plummer-Vinson syndrome--a rare presentation in a child

Plummer-Vinson (Paterson, Brown-Kelly) syndrome refers to the association of iron-deficiency anaemia with dysphagia secondary to a post-cricoid web. Only seven cases of Plummer-Vinson syndrome in children and adolescents between the ages of 14 and 19 have been reported in the world literature. We report a case of the syndrome occurring in a child of 14 years and provide a short review of the present knowledge concerning the symptom complex.

Long-term follow-up of submandibular duct rerouting for the treatment of sialorrhea in the pediatric population

OBJECTIVE

To determine the long-term control of sialorrhea in children who underwent submandibular duct rerouting (SMDR) and to identify potential preoperative predictors of outcome.

DESIGN

Retrospective chart review of children who underwent SMDR; information updated by discussion with the permanent caregiver.

SETTING

Tertiary care center.

PATIENTS

Children who had significant sialorrhea resulting from a variety of neuromuscular disabilities between January 1980 and December 1995.

OUTCOME

We report the outcome on 59 patients who underwent SMDR for the treatment of sialorrhea. Patients were ascribed a preoperative sialorrhea and global neurologic deficit score. Postoperative outcome was scored as marked, moderate, no improvement, or worse. Twenty-eight of 59 (47.4%), 28 of 59 (47.4%), and 3 of 59 (5.1%) of the patients had preoperative sialorrhea scores of 3 (profuse), 2 (moderate), and 1 (mild), respectively. Twenty of 59 (33.9%), 29 of 59 (49.2%), and 10 of 59 (16.9%) had preoperative scores of 3 (severe), 2 (moderate), and 1 (mild) neurologic impairment, respectively. Mean time to follow-up of the 59 patients was 5.46 years. Postoperative improvement scores were as follows: 50.8% had marked, 28.8% had moderate, and 20% had no to minimal improvement in their sialorrhea. Two patients were transiently worse. A complication rate of 11.3% (9 of 79) was demonstrated: 7 ranulae, 1 transient swelling of the floor of the mouth, and 1 submandibular gland infection. The preoperative global neurologic deficit score was found to be more predictive of surgical outcome than sialorrhea score.

Update on paediatric tracheostomy tubes

In the recent past there has been a significant expansion in the range of paediatric tracheostomy tubes available. This has mainly been in response to clinicians' requests. This article reviews those now available and the situations in which they are useful. A sizing chart is included for easy reference.

Laryngeal paraganglioma in a five-year-old child--the youngest case ever recorded

A paraganglioma is a neuroendocrine neoplasm that originates from the paraganglion cells of the parasympathetic system. The average age of presentation is in the fifth decade. We report a case of laryngeal paraganglioma in a five-year-old child, the youngest case ever recorded. The features of paraganglioma which differentiate it from other tumours are also discussed.

Labyrinthine involvement in Langerhans' cell histiocytosis

BACKGROUND

Langerhans' cell histiocytosis, a rare condition caused by the proliferation of abnormal Langerhans' cells ('LCH cells') and an accompanying granulomatous infiltrate, can affect several organs including the ear. External and middle ear involvement are common with a reported incidence as high as 61%. The bony labyrinth is resistant to erosion by the granulation tissue, thereby protecting the cochlea and vestibular structures. Probably for this reason, involvement of the inner ear is rare, with few case reports in the literature.

PATIENTS

We report two girls, one with bilateral and the other with unilateral mastoid involvement, in whom there was invasion of the labyrinth. The first girl had 'single system' LCH affecting only bone and developed an acute hearing loss due to invasion of the cochlea, while the second had both bone and skin involvement and labyrinthine involvement was diagnosed on imaging prior to the onset of labyrinthine symptoms.

CONCLUSION

Inner ear involvement can lead to permanent deafness, which may be prevented by early institution of treatment. Threatened inner ear involvement requires urgent systemic medical therapy with steroids, possibly combined with chemotherapy.

Nurse case management to improve glycemic control in diabetic patients in a health maintenance organization. A randomized, controlled trial

BACKGROUND

Control of hyperglycemia delays or prevents complications of diabetes, but many persons with diabetes do not achieve optimal control.

OBJECTIVE

To compare diabetes control in patients receiving nurse case management and patients receiving usual care.

DESIGN

Randomized, controlled trial.

SETTING

Primary care clinics in a group-model health maintenance organization (HMO).

PATIENTS

17 patients with type 1 diabetes mellitus and 121 patients with type 2 diabetes mellitus.

INTERVENTION

The nurse case manager followed written management algorithms under the direction of a family physician and an endocrinologist. Changes in therapy were communicated to primary care physicians. All patients received ongoing care through their primary care physicians.

MEASUREMENTS

The primary outcome, hemoglobin A1c (HbA1c) value, was measured at baseline and at 12 months. Fasting blood glucose levels, medication type and dose, body weight, blood pressure, lipid levels, patient-perceived health status, episodes of severe hypoglycemia, and emergency department and hospital admissions were also assessed.

RESULTS

72% of patients completed follow-up. Patients in the nurse case management group had mean decreases of 1.7 percentage points in HbA1c values and 43 mg/dL (2.38 mmol/L) in fasting glucose levels; patients in the usual care group had decreases of 0.6 percentage points in HbA1c values and 15 mg/dL (0.83 mmol/L) in fasting glucose levels (P < 0.01). Self-reported health status improved in the nurse case management group (P = 0.02). The nurse case management intervention was not associated with statistically significant changes in medication type or dose, body weight, blood pressure, or lipids or with adverse events.

CONCLUSIONS

A nurse case manager with considerable management responsibility can, in association with primary care physicians and an endocrinologist, help improve glycemic control in diabetic patients in a group-model HMO.

Management of subglottic haemangioma

Two contrasting methods of treatment for paediatric subglottic haemangioma are presented. Dr Hoeve describes his results using intralesional steroids and short-term intubation, and Dr Froehlich discusses his outcomes with open surgical excision. Mr Bailey then reviews the currently available therapeutic options with special reference to each of the above techniques, and suggests an optimum plan of management given our current state of knowledge. The conclusion is that very small haemangiomas may not require treatment, or may be amenable to CO2 laser vaporization. Medium-sized lesions seem suitable for intra-lesional steroids and intubation, but large ones are probably best managed by primary submucous resection. Very large haemangiomas, and especially those which are circumferential or in which magnetic resonance imaging (MRI) shows extension down into the trachea and/or through the tracheal wall into the surrounding tissues, may be more safely dealt with by performing a tracheostomy and awaiting spontaneous involution.