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.

Optimization of diarylamines as non-nucleoside inhibitors of HIV-1 reverse transcriptase

Following computational analyses, potential non-nucleoside inhibitors of HIV-1 reverse transcriptase have been pursued through synthesis and assaying for anti-viral activity. The general class Het-NH-Ph-U has been considered, where Het is an aromatic heterocycle and U is an unsaturated, hydrophobic group. Results for compounds with Het=2-thiazoyl and 2-pyrimidinyl are the focus of this report.

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.

Bioinformatics, genomics and evolution of non-flagellar type-III secretion systems: a Darwinian perpective

We review the biology of non-flagellar type-III secretion systems from a Darwinian perspective, highlighting the themes of evolution, conservation, variation and decay. The presence of these systems in environmental organisms such as Myxococcus, Desulfovibrio and Verrucomicrobium hints at roles beyond virulence. We review newly discovered sequence homologies (e.g., YopN/TyeA and SepL). We discuss synapomorphies that might be useful in formulating a taxonomy of type-III secretion. The problem of information overload is likely to be ameliorated by launch of a web site devoted to the comparative biology of type-III secretion ().

Bioinformatics analysis of the locus for enterocyte effacement provides novel insights into type-III secretion

Background

Like many other pathogens, enterohaemorrhagic and enteropathogenic strains of Escherichia coli employ a type-III secretion system to translocate bacterial effector proteins into host cells, where they then disrupt a range of cellular functions. This system is encoded by the locus for enterocyte effacement. Many of the genes within this locus have been assigned names and functions through homology with the better characterised Ysc-Yop system from Yersinia spp. However, the functions and homologies of many LEE genes remain obscure.

Results

We have performed a fresh bioinformatics analysis of the LEE. Using PSI-BLAST we have been able to identify several novel homologies between LEE-encoded and Ysc-Yop-associated proteins: Orf2/YscE, Orf5/YscL, rORF8/EscI, SepQ/YscQ, SepL/YopN-TyeA, CesD2/LcrR. In addition, we highlight homology between EspA and flagellin, and report many new homologues of the chaperone CesT.

Conclusion

We conclude that the vast majority of LEE-encoded proteins do indeed possess homologues and that homology data can be used in combination with experimental data to make fresh functional predictions.

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.

The ETT2 gene cluster, encoding a second type III secretion system from Escherichia coli, is present in the majority of strains but has undergone widespread mutational attrition

ETT2 is a second cryptic type III secretion system in Escherichia coli which was first discovered through the analysis of genome sequences of enterohemorrhagic E. coli O157:H7. Comparative analyses of Escherichia and Shigella genome sequences revealed that the ETT2 gene cluster is larger than was previously thought, encompassing homologues of genes from the Spi-1, Spi-2, and Spi-3 Salmonella pathogenicity islands. ETT2-associated genes, including regulators and chaperones, were found at the same chromosomal location in the majority of genome-sequenced strains, including the laboratory strain K-12. Using a PCR-based approach, we constructed a complete tiling path through the ETT2 gene cluster for 79 strains, including the well-characterized E. coli reference collection supplemented with additional pathotypes. The ETT2 gene cluster was found to be present in whole or in part in the majority of E. coli strains, whether pathogenic or commensal, with patterns of distribution and deletion mirroring the known phylogenetic structure of the species. In almost all strains, including enterohemorrhagic E. coli O157:H7, ETT2 has been subjected to varying degrees of mutational attrition that render it unable to encode a functioning secretion system. A second type III secretion system-associated locus that likely encodes the ETT2 translocation apparatus was found in some E. coli strains. Intact versions of both ETT2-related clusters are apparently present in enteroaggregative E. coli strain O42.

Defining a molecular mechanism of synergy between nucleoside and nonnucleoside AIDS drugs

Combination therapies treating human immunodeficiency virus type 1 (HIV-1) infection delay the emergence of drug-resistant virus and exhibit synergistic inhibition. This synergy is observed within the two classes of inhibitors that target the essential viral reverse transcriptase (RT): the chain-terminating nucleoside analogs (NRTIs) and the allosteric nonnucleosides (NNRTIs) that bind in a pocket distinct from the active site. A general mechanism to define the molecular basis for synergy between these two classes remains to be elucidated. Previous mechanistic studies from our laboratory (Spence, R. A., Kati, W. M., Anderson, K. S., and Johnson, K. A. (1995) Science 267, 988-993) have shown that the natural deoxynucleoside triphosphate and the NNRTI can simultaneously bind to their respective sites. This work also suggests communication between the two sites, since the inhibition of RT by NNRTIs is manifested through a remote effect on the chemical step. This interplay between the two sites offers a plausible hypothesis for understanding synergy in which binding of NNRTIs modulates the chain termination by NRTIs. The present study supports this hypothesis by illustrating that the clinically approved NNRTIs, nevirapine and efavirenz, inhibit the ATP-mediated removal of AZTMP, d4TMP, ddCMP, (-)3TCMP, (-)FTCMP, and (+)3TCMP, thereby prolonging the effectiveness of chain termination. This inhibition is mediated through an effect on both the rate of the chemical step and binding of ATP, resulting in an overall decrease in efficiency of removal. This work substantiates communication between the two binding pockets, the sustained use of combination therapy to treat HIV infection, and a molecular basis for understanding synergy.

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.