Integrative methods reveal multiple drivers of diversification in rice paddy snakes

Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescent demographic models to investigate the diversification of poorly known rice paddy snakes from Southeast Asia (Homalopsidae: Hypsiscopus), which have conflicting dates of origin based on previous studies. We use coalescent modeling to test the hypothesis that Hypsiscopus diversified 2.5 mya during the Khorat Plateau uplift in Thailand. Additionally, we use ecological niche analyses to identify potential differences in the niche space of the two most widely distributed species in the past and present. Our results suggest Hypsiscopus diversified ~ 2.4 mya, supporting that the Khorat Plateau may have initiated the diversification of rice paddy snakes. We also find significant niche differentiation and shifts between species of Hypsiscopus, indicating that environmental differences may have sustained differentiation of this genus after the Khorat Plateau uplift. Our study expands on the diversification history of snakes in Southeast Asia, and highlights how results from smaller multilocus datasets can be useful in developing and testing biogeographic hypotheses alongside genomic datasets.

Comparative phylogeography reveals widespread cryptic diversity driven by ecology in Panamanian birds

Widespread species often harbor unrecognized genetic diversity, and investigating the factors associated with such cryptic variation can help us better understand the forces driving diversification. Here, we identify potential cryptic species based on a comprehensive dataset of COI mitochondrial DNA barcodes from 2,333 individual Panamanian birds across 429 species, representing 391 (59%) of the 659 resident landbird species of the country, as well as opportunistically sampled waterbirds. We complement this dataset with additional publicly available mitochondrial loci, such as ND2 and cytochrome b, obtained from whole mitochondrial genomes from 20 taxa. Using barcode identification numbers (BINs), we find putative cryptic species in 19% of landbird species, highlighting hidden diversity in the relatively well-described avifauna of Panama. Whereas some of these mitochondrial divergence events corresponded with recognized geographic features that likely isolated populations, such as the Cordillera Central highlands, the majority (74%) of lowland splits were between eastern and western populations. The timing of these splits are not temporally coincident across taxa, suggesting that historical events, such as the formation of the Isthmus of Panama and Pleistocene climatic cycles, were not the primary drivers of cryptic diversification. Rather, we observed that forest species, understory species, insectivores, and strongly territorial species-all traits associated with lower dispersal ability-were all more likely to have multiple BINs in Panama, suggesting strong ecological associations with cryptic divergence. Additionally, hand-wing index, a proxy for dispersal capability, was significantly lower in species with multiple BINs, indicating that dispersal ability plays an important role in generating diversity in Neotropical birds. Together, these results underscore the need for evolutionary studies of tropical bird communities to consider ecological factors along with geographic explanations, and that even in areas with well-known avifauna, avian diversity may be substantially underestimated.

LAY SUMMARY

- What factors are common among bird species with cryptic diversity in Panama? What role do geography, ecology, phylogeographic history, and other factors play in generating bird diversity?- 19% of widely-sampled bird species form two or more distinct DNA barcode clades, suggesting widespread unrecognized diversity.- Traits associated with reduced dispersal ability, such as use of forest understory, high territoriality, low hand-wing index, and insectivory, were more common in taxa with cryptic diversity. Filogeografía comparada revela amplia diversidad críptica causada por la ecología en las aves de Panamá.

RESUMEN

Especies extendidas frecuentemente tiene diversidad genética no reconocida, y investigando los factores asociados con esta variación críptica puede ayudarnos a entender las fuerzas que impulsan la diversificación. Aquí, identificamos especies crípticas potenciales basadas en un conjunto de datos de códigos de barras de ADN mitocondrial de 2,333 individuos de aves de Panama en 429 especies, representando 391 (59%) de las 659 especies de aves terrestres residentes del país, además de algunas aves acuáticas muestreada de manera oportunista. Adicionalmente, complementamos estos datos con secuencias mitocondriales disponibles públicamente de otros loci, tal como ND2 o citocroma b, obtenidos de los genomas mitocondriales completos de 20 taxones. Utilizando los números de identificación de código de barras (en ingles: BINs), un sistema taxonómico numérico que proporcina una estimación imparcial de la diversidad potencial a nivel de especie, encontramos especies crípticas putativas en 19% de las especies de aves terrestres, lo que destaca la diversidad oculta en la avifauna bien descrita de Panamá. Aunque algunos de estos eventos de divergencia conciden con características geográficas que probablemente aislaron las poblaciones, la mayoría (74%) de la divergencia en las tierras bajas se encuentra entre las poblaciones orientales y occidentales. El tiempo de esta divergencia no coincidió entre los taxones, sugiriendo que eventos históricos tales como la formación del Istmo de Panamá y los ciclos climáticos del pleistoceno, no fueron los principales impulsores de la especiación. En cambio, observamos asociaciones fuertes entre las características ecológicas y la divergencia mitocondriale: las especies del bosque, sotobosque, con una dieta insectívora, y con territorialidad fuerte mostraton múltiple BINs probables. Adicionalmente, el índice mano-ala, que está asociado a la capacidad de dispersión, fue significativamente menor en las especies con BINs multiples, sugiriendo que la capacidad de dispersión tiene un rol importamente en la generación de la diversidad de las aves neotropicales. Estos resultos demonstran la necesidad de que estudios evolutivos de las comunidades de aves tropicales consideren los factores ecológicos en conjunto con las explicaciones geográficos. Palabras clave: biodiversidad tropical, biogeografía, códigos de barras, dispersión, especies crípticas.

Comparative phylogeography reveals widespread cryptic diversity driven by ecology in Panamanian birds

Widespread species often harbor unrecognized genetic diversity, and investigating the factors associated with such cryptic variation can help us better understand the forces driving diversification. Here, we identify potential cryptic species based on a comprehensive dataset of COI mitochondrial DNA barcodes from 2,333 individual Panamanian birds across 429 species, representing 391 (59%) of the 659 resident landbird species of the country, as well as opportunistically sampled waterbirds. We complement this dataset with additional publicly available mitochondrial loci, such as ND2 and cytochrome b, obtained from whole mitochondrial genomes from 20 taxa. Using barcode identification numbers (BINs), we find putative cryptic species in 19% of landbird species, highlighting hidden diversity in the relatively well-described avifauna of Panama. Whereas some of these mitochondrial divergence events corresponded with recognized geographic features that likely isolated populations, such as the Cordillera Central highlands, the majority (74%) of lowland splits were between eastern and western populations. The timing of these splits are not temporally coincident across taxa, suggesting that historical events, such as the formation of the Isthmus of Panama and Pleistocene climatic cycles, were not the primary drivers of cryptic diversification. Rather, we observed that forest species, understory species, insectivores, and strongly territorial species-all traits associated with lower dispersal ability-were all more likely to have multiple BINs in Panama, suggesting strong ecological associations with cryptic divergence. Additionally, hand-wing index, a proxy for dispersal capability, was significantly lower in species with multiple BINs, indicating that dispersal ability plays an important role in generating diversity in Neotropical birds. Together, these results underscore the need for evolutionary studies of tropical bird communities to consider ecological factors along with geographic explanations, and that even in areas with well-known avifauna, avian diversity may be substantially underestimated.

A new species of Bush frog (Anura, Rhacophoridae, Raorchestes) from southeastern Yunnan, China

In this study, based on morphological and molecular data, a new bush frog species is described from Yunnan, China. Eleven samples of Raorchestes malipoensissp. nov. were collected from Malipo County, southeastern Yunnan. This species can be distinguished from other congeners by a combination of 13 morphological characters. Phylogenetic analyses based on the 16S rRNA gene indicate that these individuals form a monophyletic group, and genetic divergence between this clade and its closest relatives is higher than 3.1%, which is comparable to the divergence between recognized Raorchestes species. The discovery of this new species suggests that additional extensive surveys in the southeastern Yunnan would yield more amphibian lineages yet unknown to science.

Maximizing Molecular Data From Low-Quality Fluid-Preserved Specimens in Natural History Collections

Over the past decade, museum genomics studies have focused on obtaining DNA of sufficient quality and quantity for sequencing from fluid-preserved natural history specimens, primarily to be used in systematic studies. While these studies have opened windows to evolutionary and biodiversity knowledge of many species worldwide, published works often focus on the success of these DNA sequencing efforts, which is undoubtedly less common than obtaining minimal or sometimes no DNA or unusable sequence data from specimens in natural history collections. Here, we attempt to obtain and sequence DNA extracts from 115 fresh and 41 degraded samples of homalopsid snakes, as well as from two degraded samples of a poorly known snake, Hydrablabes periops. Hydrablabes has been suggested to belong to at least two different families (Natricidae and Homalopsidae) and with no fresh tissues known to be available, intractable museum specimens currently provide the only opportunity to determine this snake’s taxonomic affinity. Although our aim was to generate a target-capture dataset for these samples, to be included in a broader phylogenetic study, results were less than ideal due to large amounts of missing data, especially using the same downstream methods as with standard, high-quality samples. However, rather than discount results entirely, we used mapping methods with references and pseudoreferences, along with phylogenetic analyses, to maximize any usable molecular data from our sequencing efforts, identify the taxonomic affinity of H. periops, and compare sequencing success between fresh and degraded tissue samples. This resulted in largely complete mitochondrial genomes for five specimens and hundreds to thousands of nuclear loci (ultra-conserved loci, anchored-hybrid enrichment loci, and a variety of loci frequently used in squamate phylogenetic studies) from fluid-preserved snakes, including a specimen of H. periops from the Field Museum of Natural History collection. We combined our H. periops data with previously published genomic and Sanger-sequenced datasets to confirm the familial designation of this taxon, reject previous taxonomic hypotheses, and make biogeographic inferences for Hydrablabes. A second H. periops specimen, despite being seemingly similar for initial raw sequencing results and after being put through the same protocols, resulted in little usable molecular data. We discuss the successes and failures of using different pipelines and methods to maximize the products from these data and provide expectations for others who are looking to use DNA sequencing efforts on specimens that likely have degraded DNA.

Life Science Identifier (Hydrablabes periops)

urn:lsid:zoobank.org:pub:F2AA44 E2-D2EF-4747-972A-652C34C2C09D.

Ecological Divergence and the History of Gene Flow in the Nearctic Milksnakes (Lampropeltis triangulum Complex)

Many phylogeographic studies on species with large ranges have found genetic-geographic structure associated with changes in habitat and physical barriers preventing or reducing gene flow. These interactions with geographic space, contemporary and historical climate, and biogeographic barriers have complex effects on contemporary population genetic structure and processes of speciation. While allopatric speciation at biogeographic barriers is considered the primary mechanism for generating species, more recently it has been shown that parapatric modes of divergence may be equally or even more common. With genomic data and better modeling capabilities, we can more clearly define causes of speciation in relation to biogeography and migration between lineages, the location of hybrid zones with respect to the ecology of parental lineages, and differential introgression of genes between taxa. Here, we examine the origins of three Nearctic milksnakes (Lampropeltis elapsoides, Lampropeltis triangulum and Lampropeltis gentilis) using genome-scale data to better understand species diversification. Results from artificial neural networks show that a mix of a strong biogeographic barrier, environmental changes, and physical space has affected genetic structure in these taxa. These results underscore conspicuous environmental changes that occur as the sister taxa L. triangulum and L. gentilis diverged near the Great Plains into the forested regions of the Eastern Nearctic. This area has been recognized as a region for turnover for many vertebrate species, but as we show here the contemporary boundary does not isolate these sister species. These two species likely formed in the mid-Pleistocene and have remained partially reproductively isolated over much of this time, showing differential introgression of loci. We also demonstrate that when L. triangulum and L. gentilis are each in contact with the much older L. elapsoides, some limited gene flow has occurred. Given the strong agreement between nuclear and mtDNA genomes, along with estimates of ecological niche, we suggest that all three lineages should continue to be recognized as unique species. Furthermore, this work emphasizes the importance of considering complex modes of divergence and differential allelic introgression over a complex landscape when testing mechanisms of speciation. [Cline; delimitation; Eastern Nearctic; Great Plains; hybrids; introgression; speciation.].

Detection of Intracytoplasmic Cytokines by Flow Cytometry in Adenoids and Peripheral Blood Lymphocytes of Children

Cytokine flow cytometry at the single-cell level has never been utilized in the study of adenoidal lymphocytes. We describe the multiparameter capability of flow cytometry to simultaneously detect an antigen on the surface of the adenoidal and peripheral blood lymphocytes and detect Th1 and Th2 cytokines within the cytoplasm of these lymphocytes. The data suggest that the percentage of cells producing interferon (IFN)-γ are decreased in adenoidal as compared to peripheral blood lymphocytes, confirming our previous studies. The new findings show that the CD8 subset of adenoidal lymphocytes produces lower amounts of IFN-γ as compared to peripheral blood CD8 cells. The intracytoplasmic synthesis of interleukin (IL)–2, however, appears to be similar in both adenoidal and peripheral blood lymphocytes. The CD4 subset of lymphocytes in the adenoid produces more IL-2, whereas the CD8 subset produces more IFN-γ. Finally, as shown in our previous studies, the Th2 cytokines appear to be produced in similar quantities in both adenoidal and peripheral blood lymphocytes.

Lack of prognostic effect of carbonic anhydrase-9, hypoxia inducible factor-1α and bcl-2 in 286 patients with early squamous cell carcinoma of the glottic larynx treated with radiotherapy

AIMS

To evaluate the prognostic significance of potential tumour markers of hypoxia and apoptosis in early squamous cell carcinoma of the glottic larynx managed with radiotherapy.

MATERIALS AND METHODS

In total, 382 patients with T1 and T2 squamous cell carcinoma of the glottic larynx (vocal cords) received radical radiotherapy (50-55 Gy, in 16 fractions in 98% of cases). Pre-treatment haemoglobin was available for 328 patients; biopsy samples were available for 286. Immunohistochemistry was carried out for carbonic anhydrase-9 (CA-9), hypoxia inducible factor-1α (HIF-1α) and Bcl-2.

RESULTS

At 5 years, locoregional control was achieved in 88.2%, cancer-specific survival in 95.0% and overall survival in 78.7%. Adverse prognostic factors for locoregional tumour recurrence were pre-treatment haemoglobin <13.0 g/dl (P = 0.035, Log rank test; sensitivity 0.28, specificity 0.84) and stage T2 rather than T1 (P = 0.002). The effect of haemoglobin level on locoregional control was not significant when stratified by the median of 14.2 g/dl (P = 0.43) or as a continuous variable (P = 0.59). High CA-9 (P = 0.11), HIF-1α (P = 0.67) and Bcl-2 (P = 0.77) expression had no prognostic significance.

CONCLUSIONS

High CA-9, HIF-1α and Bcl-2 do not add to the prognostic significance of tumour stage and lower haemoglobin in predicting failure of local control in early glottic larynx squamous cell carcinoma managed with radiotherapy. The effect of haemoglobin was not strong enough to be useful as a prognostic biomarker.

Sphenoid cranial base defects in siblings presenting with cerebrospinal fluid leak

Two sisters presented to our medical center with nontraumatic cerebrospinal fluid (CSF) fistulas from left sphenoid sinocranial junction defects. One sister had recurrent meningitis over a 20-year period that prompted a skull base evaluation. Four years later, her younger sister presented with profuse CSF rhinorrhea. Transethmoid sphenoidotomy with sinus obliteration and lumbar-subarachnoid temporary CSF diversion successfully treated one sister, while the other required reoperation and permanent lumbar-peritoneal shunting. In both cases the skull base defect was identically located in the posterolateral left sphenoid sinus. Embryological considerations, evaluation and management are presented.

Resistance of Pseudomonas to ciprofloxacin: implications for the treatment of malignant otitis externa

For fifteen years oral ciprofloxacin has been the standard treatment for malignant otitis externa, a sometimes fatal osteomyelitis of the skull base usually caused by Pseudomonas aeruginosa. Resistance to ciprofloxacin is developing. Over a 16-month period, we saw five cases where malignant otitis externa progressed, with the development of cranial nerve palsies in four cases, despite oral ciprofloxacin. Prolonged intravenous antibiotic therapy became necessary. One case was managed largely as an out-patient, but four patients spent many weeks in hospital. Only two cases had diabetes and this was monitored and controlled. Pseudomonas aeruginosa was isolated in four of the five cases, but antibiotic sensitivity to ciprofloxacin was not determined. In one case a later isolate was tested and found to be ciprofloxacin resistant. Progress was monitored by serial C-reactive protein (CRP) and white cell count. For diagnosis and assessing response to treatment we considered serial magnetic resonance imaging or computed tomography more useful than isotope bone scan. There must be a readiness to use intravenous antibiotics, as a response to ciprofloxacin can no longer be assumed. Bacterial isolates must be tested for sensitivity to antibiotics including ciprofloxacin, and further biopsy and culture are essential if treatment fails.

Sore throat in adults – does the introduction of a clinical scoring system improve the management of these patients in a secondary care setting?

Objective: To audit sore throat management in adults, introduce proforma-based guidelines and to reaudit clinical practice.

Setting: Adult emergency department of an inner city teaching hospital.

Methods: A literature search was carried out to identify relevant guidelines. In stage one, patients presenting to the emergency department with sore throat were identified retrospectively from the emergency department attendance register. Proformas were completed retrospectively. In stage two, new guidelines were introduced and staff educated about the guidelines. In stage three, patients presenting with sore throat were identified at triage and proformas were completed at time of consultation.

Outcome Measures: (1) appropriate clinical assessment of the likelihood of bacterial infection using the clinical scoring system, (2) appropriateness of antibiotic prescription, (3) recommendation of supportive treatments to patients.

Results: Introduction of a clinical scoring system reduced the inappropriate prescribing of antibiotics from 44 per cent to 11 per cent. Correct antibiotic prescription rose from 60 per cent to 100 per cent. Although the variety of advice given about supportive treatment increased, the actual number of patients receiving documented supportive advice fell from 67.8 per cent in stage one to 58 per cent in stage three.

Conclusion: The introduction of clinically based guidelines for the diagnosis and management of sore throat in adults can reduce inappropriate antibiotic prescribing.

Localization and quantitation of eotaxin mRNA in human nasal polyps

Nasal Polyps (NPs) are the most common mass lesions found in the nose. NPs cause airway obstruction, prevent normal sinus function, and can lead to infection of the eye, facial bones and central nervous system. The predominant cell type inhabiting NPs is the eosinophil, and the chemokine eotaxin is believed to play an important role in NP eosinophilia. The objective of this study was to localize and quantitate expression of eotaxin mRNA in human NPs. Total RNA was isolated from NPs that were collected from 5 patients who had undergone polypectomy. Portions of these polyps were also fixed in formalin, embedded in paraffin, and sectioned onto slides for use in in situ hybridization. Total RNA from one patient was used in a reverse transcriptase polymerase chain reaction using eotaxin specific primers to generate a human eotaxin cDNA. The eotaxin cDNA was cloned and used to generate probes for Northern blot analyses and for use in in situ hybridization (ISH). Eotaxin mRNA was detected by Northern analyses in all patient samples, though the relative expression level in each patient varied. ISH localized the expression of eotaxin mRNA specifically in eosinophils in 2 of the 3 patients in the study for whom the embedded polyp tissue appeared sufficiently well preserved for mRNA localization. Our findings suggest that eosinophilia in NPs is likely a self-amplification process whereby increasing numbers of eosinophils are recruited to enter the polyp as a result of production of eotaxin by eosinophils already within the polyp.

Molecular typing of paired bacterial isolates from the adenoid and lateral wall of the nose in children undergoing adenoidectomy: implications in acute rhinosinusitis

OBJECTIVE

Recent studies have suggested that the origin of bacteria that enter the lateral wall of the nose and paranasal sinuses arise from the nasopharynx. The purpose of this study was to compare the molecular biological profiles of potential pathogens found in the nasopharynx and lateral wall of the nose concomittantly in children undergoing surgery for upper respiratory tract disease.

STUDY DESIGN AND SETTING

Fifty-two children undergoing adenoidectomy for either tonsillectomy or adenoidectomy (hypertrophy) or otitis media with effusion were studied. Bacterial cultures were taken from the crypts of the adenoids and from the lateral wall of the nose under endoscopic control after sterilization of the vestibule and inferior turbinate. Routine cultures of these areas were performed in the bacteriology laboratory of the Children's Hospital of Buffalo.

RESULTS

Bacterial pathogens were isolated from 79% of adenoids and 46% of lateral walls of the nose. Molecular typing of pairs of nontypable Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis revealed that in 16 of 18 pairs (89%) the identical strain was present in both sites simultaneously.

CONCLUSIONS

These results support the concept that when potential bacterial pathogens that may cause acute bacterial rhinosinusitis are found concomitantly in the nasopharynx and lateral wall of the nose, they are usually identical.

Fine needle aspiration biopsy of pediatric head and neck masses

OBJECTIVE

To determine if fine needle aspiration (FNA) can preclude the requirement for diagnostic open biopsy in suspicious pediatric head and neck masses.

METHODS

The records of 40 children presenting to an inner city tertiary care hospital who underwent a total of 50 FNA biopsies during the years 1988-1999 were reviewed. From these 40 patients, 17 children, aged 3 months to 18 years, underwent both clinically indicated FNA biopsy and subsequent open surgical biopsy or excision. Outcome measurements included clinical resolution or surgical pathologic diagnosis.

RESULTS

The 17 patients who underwent open surgical biopsy subsequent to the FNA had a total of 21 FNAs performed. Three of these patients had more than one needle biopsy prior to surgery. The histologic diagnosis of the surgical excision confirmed the FNA biopsy cytologic diagnosis in all but two cases. FNA cytologic diagnostic categories included reactive lymph node/non-specific inflammation (25 biopsies), benign cystic process (four), granulomatous disease (eight), malignant neoplasm (three), and benign neoplasm (one). Eight of nine FNAs initially non-diagnostic had either complete resolution of the mass or a diagnosis obtained by subsequent FNA or open biopsy.

CONCLUSIONS

FNA is a valuable diagnostic tool in the management of children with the clinical presentation of a suspicious neck mass. The technique reduces the need for more invasive and costly procedures. Early surgical biopsy, however, should be considered in rapidly enlarging masses, in the presence of persistent systemic symptoms, and when repeated FNA cytology is non-diagnostic.

The molecular biology of nasal polyposis

The molecular biologic events in the development of nasal polyps are now becoming unraveled. It appears that eosinophils are the dominant inflammatory cell present in this tissue. The events leading up to the extravasation of eosinophils into the lamina propria nasal polyps are regulated by the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-1 beta. These cytokines upregulate very late antigen-4 on the surface of eosinophils and vascular cell adhesion molecule-1 on the surface of the endothelial blood vessel. Chemokines such as RANTES (regulated upon activation, normal T-cell expressed and secreted) and eotaxin are responsible for the movement of eosinophils into the lamina propria of the nasal polyp. The release of major basic protein has an effect on alteration of the epithelial architecture and on the sodium and chloride flux into and out of the apical epithelial cell of the tissue. Finally, the alteration of the surface epithelium results in a defect in the migration of the cystic fibrosis transmembrane regulator protein to the apical surface. These two events, the release of major basic protein from the eosinophil and the alteration of the architecture of the surface epithelium, lead to an increase in sodium absorption and resultant edema: the hallmark of the pathology of the nasal polyp.

Intracranial complications of acute mastoiditis

OBJECTIVE

Oral antibiotic use may have changed the incidence and microbiology of otitic intracranial complications. We reviewed cases of acute mastoiditis to document: (1) incidence of intracranial complications; (2) risk factors; and (3) identify pathologic organisms.

METHODS

A retrospective study of children at a tertiary care children's hospital with acute mastoiditis from July, 1986 through June, 1998.

RESULTS

118 children with acute mastoiditis were identified. Eight patients (6.8%), ages 20 months to 14 years, had intracranial complications related to acute mastoiditis. Three children had a sigmoid sinus thrombosis, two children had an epidural abscess, and two children had both complications of sigmoid sinus thrombosis and epidural abscess, and a sigmoid sinus thrombosis and meningitis was present in one child. Pre-admission oral antibiotics were administered for an average of 10 days in seven of the eight patients. Persistent otorrhea and/or otalgia were present in all patients. Intraoperative cultures were negative in four cases (50%). Organisms isolated included: Streptococcus pneumoniae (2); Proteus mirabilis (1); Pseudomonas aeruginosa (1); and coagulase negative Staphylococcus (1). Multi-drug resistant organisms were documented in only one case. All patients underwent a contrast enhanced CT of the temporal bones and brain. Surgical management included complete mastoidectomy in all patients and a pressure equalization tube in seven of the eight cases.

CONCLUSIONS

Our review did not document an increase in the incidence of otitic intracranial complications. Persistent otalgia or otorrhea while on oral antibiotics with associated neurologic symptoms are ominous signs suggestive of a complication. Multi-drug resistant organisms are uncommon whereas negative intraoperative cultures are common.

Bacteria-mucin interaction in the upper aerodigestive tract shows striking heterogeneity: implications in otitis media, rhinosinusitis, and pneumonia

The mucociliary system of the upper and lower respiratory tracts is a critical nonspecific pathway for the elimination of bacteria and other particulate matter. The interaction between bacteria and purified mucin of the upper and lower respiratory tracts has been a major focus of our laboratory for the past decade. We have previously demonstrated that nontypable Haemophilus influenzae and Moraxella catarrhalis adhere to human purified nasopharyngeal mucin and human middle ear mucin by a very limited number of specific outer membrane proteins. There have been no previous studies on the interaction of Streptococcus pneumoniae and purified mucin. Such information would be of extreme importance in identifying specific mechanisms of preventing colonization of this important pathogen to nasopharyngeal mucin. Using an overlay technique of purified radiolabeled mucins of the upper and lower respiratory tracts in a solid phase assay with 4 predominant pathogens of the upper and lower respiratory tracts, we found a striking heterogeneity of bacteria-mucin interaction. The implications of these interactions in the development of otitis media, rhinosinusitis, and lower respiratory infections are briefly discussed.

Geographic variation in allergic fungal rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) has a worldwide distribution. This survey of 20 otolaryngologic practices throughout the United States confirmed a variation in the frequency of AFRS relative to endoscopic sinus procedures performed for all other diagnoses. The highest incidence occurred in Memphis, Tennessee at 23%, with three other southern practices reporting a frequency of at least 10%. In the northern locations the frequency ranged from 0 to 4%. No correlation with mould counts was demonstrated, possibly because of incomplete mould data relative to most of the surgical locations.

Management and complications of congenital dacryocele with concurrent intranasal mucocele

INTRODUCTION

The association of dacryocele and intranasal mucocele has been previously reported. Its incidence and optimal treatment are unknown.

PATIENTS AND METHODS

A retrospective review of 22 patients with 30 dacryoceles was performed to determine the mean age at presentation, sex distribution, and prevalence of associated intranasal mucocele, associated dacryocystitis, and respiratory distress. The components of the examination, ancillary tests, treatment modalities, and treatment outcomes were then summarized.

RESULTS

Unilateral dacryoceles were seen in 16 (73%) of the infants, and bilateral dacryoceles were seen in 6 (27%) of the infants. Four (25%) of the 16 patients who initially had unilateral dacryoceles later developed bilateral dacryoceles. Dacryocystitis, preseptal cellulitis, or both were present on presentation or developed in 18 (60%) of 30 dacryoceles. Nasal endoscopy was performed on 13 (59%) of 22 patients. Nasal examination with nasal speculum and headlight was performed on 7 patients (32%). A concurrent intranasal mucocele was diagnosed in 23 (77%) of 30 dacryoceles. Respiratory distress arose in 5 (71%) of 7 patients with bilateral intranasal mucoceles and in 2 (22%) of 9 patients with a unilateral intranasal mucocele. Thirty-four procedures were performed. Seven dacryoceles (21%) were treated with nasolacrimal duct probing under topical anesthesia. Another one (3%) was treated with needle aspiration with later definitive therapy. All other procedures were managed under general anesthesia. These included 2 nasolacrimal duct probings (6%), 2 probings with silicone tube placement (6%), 10 probings with intranasal mucocele marsupialization and silicone tube placement (29%), and 12 probings with marsupialization alone (35%). Two (29%) of the 7 probings performed under topical anesthesia failed, whereas all other procedures were successful. One dacryocele spontaneously resolved.

CONCLUSIONS

Congenital dacryoceles are commonly associated with intranasal mucoceles, dacryocystitis, and preseptal cellulitis. Respiratory distress is common in bilateral cases. Bilateral nasolacrimal duct probing should be considered in unilateral cases because of the high incidence of occult contralateral involvement.

Waldeyer's ring and otitis media: the nasopharyngeal tonsil and otitis media

This overview of the relationship between the nasopharyngeal tonsil and otitis media will review three important concepts: (1) Adenoid inflammation leads to inflammatory obstruction of the Eustachian tube; (2) early colonization of the adenoid with the three major bacterial pathogens of otitis media is the most important factor in the early pathogenesis of otitis media; (3) the local immune system in the adenoid particularly specific secretory IgA directed against both viruses and bacterial pathogens are probably genetically controlled and represent the immunological factor in protecting the host against invasion of these agents in the Eustachian tube and middle ear. This overview of the relationship between the adenoid and the development of otitis media emphasizes that nasopharyngeal colonization with the three major middle ear pathogens is among the most important risk factors in the pathogenesis of otitis media. Inasmuch as these pathogens normally reside in the nasopharynges of most healthy children, the factors which trigger development of otitis media need to be carefully evaluated. Among these two triggers are viral infections and upper respiratory tract allergy.

Cellular immune response of adenoidal and tonsillar lymphocytes to the P6 outer membrane protein of non-typeable Haemophilus influenzae and its relation to otitis media

Cellular immune responses to the P6 outer membrane protein of non-typeable Haemophilus influenzae (NTHi) were determined in vitro by measuring immunoglobulin (Ig) secreting cells and lymphocyte proliferation in adenoidal and tonsillar lymphocytes from 19 children. Preliminary tests showed that P6 did not stimulate naive cells such as cord blood lymphocytes, but did stimulate sensitized cells in adenoids and tonsils. Cellular proliferation was significantly higher in adenoidal lymphocytes than in tonsillar lymphocytes (median: quadratile of stimulation index = 3.7:2.3-5.5 vs. 1.2:1.0-2.1, p < 0.02). A comparison between children with or without otitis media revealed that proliferative responses to P6 of adenoidal lymphocytes from children with otitis media were significantly decreased (2.0:1.8-3.6 vs. 3.7:2.3-5.5, p < 0.04). P6-specific antibody secreting cells were identified in a total of 14 adenoids and the number of cells secreting IgA was decreased in the otitis media group compared to controls (median: quadratile/10(6) cells = 435:359-499 vs. 755:593-1870, p < 0.05). Cultivation with P6 stimulated IgA secretion in children without otitis media, while no response was seen in children with otitis media (median: quadratile/10(6) cells = 1323:915-2410 vs. 2240:1900-2830, p < 0.02). These preliminary data demonstrate that lymphocytes from adenoids and tonsils recognize P6 as a specific antigen and that the adenoid is the more reactive of the two organs. Impaired P6-specific cellular immune responses of adenoids in children with otitis media may explain the recurrent nature of otitis media due to NTHi in the otitis prone population.

Treatment of community-acquired pneumonia--IDSA guidelines. Infectious Diseases Society of America

The Infectious Diseases Society of America (IDSA) has published guidelines for the treatment of community-acquired pneumonia (CAP). Although Streptococcus pneumoniae remains the most common etiologic agent, Chlamydia pneumoniae and Legionella pneumophila are also important causes. For all suspected CAP patients, particularly those requiring hospitalization, chest radiographs are strongly recommended to confirm the diagnosis. The IDSA guidelines, in contrast to those published by the American Thoracic Society, emphasize the use of sputum Gram's stain and culture in all patients, whenever possible, to establish etiology. This information can be used not only to guide therapy but also to track trends in the etiologic pathogens for CAP and their antibiotic susceptibility. In light of the better outcomes with the earliest possible interventions, the IDSA recommends initial empiric antimicrobial therapy until laboratory results can be obtained to guide more specific therapy. Macrolides, doxycycline, and fluoroquinolones are suggested for primary empiric therapy, since each has activity against common bacterial pathogens and atypical agents. Detailed antibiotic recommendations are made for various pathogens. For inpatients, attempts should be made to cover Legionella and other common pathogenic bacteria. Alternative antibiotics are recommended for patients with structural diseases of the lung, penicillin allergy, or suspected aspiration pneumonia. Switch to an appropriate oral antibiotic is recommended as soon as the patient's condition is stable and he or she can tolerate oral therapy, often within 72 h.

Stenotrophomonas maltophilia infection and colonization in the intensive care units of two community hospitals: A study of 143 patients

STUDY OBJECTIVE

To study the epidemiology of Stenotrophomonas maltophilia infections in the intensive care units (ICUs) of community general hospitals.

DESIGN

Retrospective chart review of 143 patients with cultures positive for S. maltophilia over a 2-year period.

SETTING

Intensive care units of 2 community general hospitals.

RESULTS

Patients with S. maltophilia infection or colonization were elderly (mean age 62.4 years), intubated for a mean of 11.8 days, and had a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 16.6. A tracheostomy was present in 22.4%, and underlying chronic respiratory disease and malignancy were found in 25.9% and 15.4%, respectively. Only 2 patients (1.4%) were neutropenic. Most isolates (89.5%) were from the respiratory tract and were part of a polymicrobial culture in 52. 5% of patients. Only a slightly higher APACHE II score (mean = 18.0, SD 7.8 vs mean = 15.6, SD 6.2, P = 0.052) differentiated patients with infection from those with colonization. All but 2 patients were exposed to antibiotics before their positive culture. Crude mortality rate was 41.3% overall and was significantly higher in those with an APACHE II score of 15 or more (48.8% vs 30.5%, P = 0. 028).

CONCLUSION

S. maltophilia is emerging as an important cause of nosocomial infection, especially pneumonia, in ICUs of community general hospitals. Patients tend to be elderly, intubated for a mean of about 12 days, have high APACHE II scores, and frequently have a tracheostomy or underlying chronic respiratory disease. In contrast to earlier reports, neutropenia and underlying malignancy are uncommon in our ICU population. We found prior antibiotic exposure was almost universal and similar to previous reports, but use of imipenem was much less common in our community hospital patients. Patients with a high APACHE II score should be considered infected rather than colonized, but differentiation of infection from colonization remains problematic. Isolation of S. maltophilia from a patient carries a crude mortality rate of 41.3%, and patients with an APACHE II score of 15 or more have a significantly higher mortality rate than those with lesser scores, approaching 50%. Trimethoprim-sulfamethoxazole (TMP-SMX) remains the drug of choice for infections caused by S. maltophilia.

Bacteriologic findings from the nose, ethmoid, and bloodstream during endoscopic surgery for chronic rhinosinusitis: implications for antibiotic therapy

This study addresses the bacterial flora of chronic rhinosinusitis at the time of endoscopic sinus surgery. We used the consensus definition of chronic rhinosinusitis as the presence of paranasal sinus inflammation present for greater than 12 weeks. In our patient study group, all cases of chronic rhinosinusitis had failed to respond to antibiotic therapy and had not been treated previously with surgery. By microscopic examination, chronic inflammatory changes were confirmed in the resected sinus lining of all study patients. Intraoperative cultures were obtained from the nasal vestibule, the middle meatus, ethmoid lining, and peripheral blood during and after the endoscopic procedure. We found approximately 30% of the patients with sterile sinuses, 50% with coagulase-negative staphylococci, and the remainder with a mixed group of "nonpathogenic" organisms. Anaerobes were conspicuously rare. The blood cultures were positive in 7% of cases and were consistent with an organism of the operative site. This is the first time bacteremia has been reported in association with endoscopic sinus surgery. The results suggest that chronic rhinosinusitis is not a bacterial disease, but rather the result of chronic inflammation produced by a previous acute inflammation. The incidence of positive blood cultures, while relatively low and cleared quickly, should alert the physician for the possible need for prophylactic antibiotics in patients with cardiac, prosthetic, or systemic conditions that could lead to metastatic infection.

Initial report on postoperative healing after endoscopic sinus surgery with the microdebrider

Synechiae formation is a frequent occurrence after endoscopic sinus surgery and may cause symptomatic sinus outflow tract obstruction. Various means are used to reduce the incidence of synechiae formation. These include meticulous operative technique, partial middle turbinate resection, middle meatus spacers or stents, and postoperative debridement. The microdebrider is a powered rotary shaving device that precisely resects tissue, minimizing inadvertent mucosal trauma and stripping. We present 40 cases of endoscopic sinus surgery performed with the microdebrider. Patients had at least a 5-month follow-up and demonstrated rapid mucosal healing, minimal crust formation, and a low incidence of synechiae formation. These initial data suggest that the microdebrider may be advantageous in surgery for chronic sinusitis.

Th1/Th2 cytokine profiles in the nasopharyngeal lymphoid tissues of children with recurrent otitis media

The cytokine profile in adenoidal lymphoid tissue was studied in 22 patients. Lymphocytes from adenoid tissues and peripheral blood were submitted for cytokine assays using an enzyme-linked immunosorbent assay kit for interferon-gamma, interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10. Adenoidal lymphocytes appear to produce significantly less Th1 cytokines (IL-2, interferon gamma) compared to the patient's peripheral blood lymphocytes, whereas IL-4 and IL-5 (Th2 cytokines) appear to be synthesized to the same extent as, if not slightly more than, in the homologous peripheral blood lymphocytes. Because the relationship between Th1 and Th2 cytokines is extremely important in modulating the immune response, it is advisable to determine the role of the cytokine profiles of T-lymphocytes in the nasopharynx and its relationship to the development of inflammation of the eustachian tube and middle ear.

The microbial ecology and immunology of the adenoid: implications for otitis media

The nasopharyngeal tonsil, or adenoid, is a major inductive site for the synthesis of J-chain-positive B cells that may migrate to other areas of the upper respiratory tract, such as the nasal mucosa, the parotid gland, the lacrimal gland, and the middle ear during inflammation. The production of secretory IgA by both the nasopharyngeal tonsil and the nasal mucosa plays a major role in local immune protection against bacteria and viruses. The release of cytokines from Th1 and Th2 lymphocytes must be appropriate for B cells to produce IgA. The factors or mechanisms responsible for this are not, at present, known, but it appears that there is a difference in the profiles of cytokine secretion by Th1 and Th2 lymphocytes in the adenoids in both otitis-prone, as well as nonotitis-prone children. We have suggested that if this specific immune system does not protect the host from invasion by potential pathogens, there are other modalities of therapy to protect the nasopharynx from colonization with pathogenic bacteria or viruses. These include the production of specific antibodies against bacterial surface proteins that have been identified as mucin-binding proteins. Alteration of the microbial flora with commensal organisms such as viridans streptococci can be utilized. These alpha-hemolytic streptococci probably function by producing an acid environment that prevents colonization of organisms such as nontypeable H. influenzae. Finally, the induction of specific SIgA by conserved outer membrane protein antigens of potential pathogens may be another strategy in the prevention of colonization of potential bacterial pathogens in the nasopharynx.

Analysis of isolates recovered from multiple sites of the nasopharynx of children colonized by nontypeable Haemophilus influenzae

To determine whether the nasopharynx of children is colonized by a single or multiple strains of nontypeable Haemophilus influenzae, cultures were obtained from six nasopharyngeal sites in five children. For each child, all isolates yielded identical polymerase chain reaction fingerprints. The results indicate that these children were colonized in the nasopharynx with a single strain of nontypeable Haemophilus influenzae at one time.

Urinary tract infections

Urinary tract infections (UTIs) are still the precipitating cause for 7 million patient visits per year with total costs exceeding one billion dollars. Diagnostic modalities have become more "friendly" for the smaller laboratory with "dip stick" culture tests providing a rapid method of isolation of pathogens. In many cases, empiric therapy is more cost effective than culture in uncomplicated UTIs in women. The etiologic organisms implicated in UTIs have not changed dramatically over the past two decades, with E. coli still accounting for the majority of cases. Antibiotic susceptibility patterns have changed dramatically, with ampicillin losing utility die to the emergence of resistance. Quinolones, which have been exceedingly active against gram-negative enteric pathogens, are no longer universally active and more pathogenic organisms, such as pseudomonas, may be resistant. The emergence of other highly resistant organisms, such as Enterococcus faecium, must be watched for.

Immunoglobulin G Subclass Response to Major outer Membrane Proteins of Nontypable Haemophilus Influenzae in Children with Acute Otitis Media

Children with acute otitis media as the result of nontypable Haemophilus influenzae often develop serum bactericidal and/or opsonic IgG antibodies to this organism during convalescence. Outer membrane proteins appear to be the principal targets for such antibodies. In this study we characterized the IgG subclass responses to major outer membrane proteins of nontypable H. influenzae in otitis-prone children in whom this organism had colonized. Three of the major outer membrane proteins (P2, P5, and P6) were isolated from the homologous nontypable H. influenzae strain recovered from the middle ear at the time of acute infection. Sera were obtained during the acute phase and at 1 and 6 months thereafter. The outer membrane proteins, which were isolated by preparative sodium dodecylsulfate-polyacrylamide gel electrophoresis, were used as test antigens in a quantitative IgG subclass enzyme immunoassay. The results of this analysis indicate that the temporal characteristics and distribution of IgG subclass antibodies were found to differ for each of the outer membrane proteins. Moreover, substantial variation between patients was observed with respect to both temporal characteristics and subclass distribution of the IgG response to the three outer membrane proteins. Significantly, sera from two of three otitis-prone subjects contained detectable levels of IgG antibody to the conserved P6 outer membrane protein at the time of acute infection, with serum from one subject also containing detectable levels of lgG3 antibody to this same protein. Nevertheless, the organism persisted in the middle ears of these patients. The results of this study indicate that otitis-prone children manifest a highly variable IgG subclass response to both conserved (P6) and variable (P2) outer membrane proteins of nontypable H. influenzae. Further study is required to ascertain whether these IgG subclass antibodies are biologically efficacious and whether otitis-prone children possess the immunologic maturity to respond to nontypable H. influenzae outer membrane protein-based vaccines in a predictable manner.

Middle ear mucin glycoprotein: purification and interaction with nontypable Haemophilus influenzae and Moraxella catarrhalis

Nontypable Haemophilus influenzae and Moraxella catarrhalis are important pathogens in children and adults. The mechanisms of their adherence to the epithelial cell surface and colonization are not clear. For the pathogen to adhere to the epithelial cell, it must first attach to and penetrate the mucus barrier. Mucin glycoproteins of the mucus layer generally are thought to be involved in bacterial attachment. To understand the precise mechanisms of middle ear mucin-bacterial interactions, we used an overlay binding assay with a highly purified middle ear mucin and outer membrane proteins of both nontypable H. influenzae and M. catarrhalis. Outer membrane proteins P2 and P5 were identified as the major components that medicate the binding between nontypable H. influenzae and human middle ear mucin. Moreover, the 57 kDa protein, CD, of the outer membrane protein of M. catarrhalis was found to be the only protein binding human middle ear mucin. Finally, it appears that a protein-oligosaccharide interaction is responsible for binding because asialo-mucin does not bind to either of the bacteria. Knowledge of the specific bacterial-mucin interaction may provide an understanding of the bacterial-epithelial cell colonization. Conversely, comprehension of this interaction between bacteria and purified mucin may be a strategy to prevent colonization of potential pathogens that cause otitis media and sinusitis in children.

Nasal polyposis: immunohistochemistry and bioelectrical findings (a hypothesis for the development of nasal polyps)

Nasal polyps and turbinates were obtained from individuals undergoing surgery for symptomatic nasal obstruction caused by nonatopic rhinosinusitis or allergic rhinosinusitis. One part of the tissue from each patient was fixed in neutral buffered formalin and prepared for study by histochemical and immunohistochemical methods. Monoclonal antibodies were used to identify macrophages, lymphocytes, and plasma cells. In most cases (12 of 16, 75%) the remainder of the polyp and turbinate samples was treated with protease to achieve disaggregation of the epithelial cells. Those cells were cultured on permeable collagen matrix supports. Transepithelial potential difference and resistance were measured daily. At the time of maximal transepithelial potential difference, the epithelial cells were mounted in modified. Ussing chambers and exposed to a sodium-positive channel blocker (amiloride hydrochloride) and to selected chloride-negative channel agonists (isoproterenol bitartrate and adenosine triphosphate). Middle turbinates and polyps were found to have more macrophages, lymphocytes, plasma cells, HLA-DR-positive cells, and eosinophils than the inferior turbinates. Epithelial cells obtained from polyps exhibited higher transepithelial potential differences and equivalent short-circuit currents than turbinate cell cultures. The responses to amiloride, isoproterenol, and adenosine triphosphate were also greater for polyp than for turbinate cultures. A theory for the pathogenesis of nasal polyps is proposed. Local release of inflammatory mediators could cause sodium absorption and chloride permeability to be higher in polyps than in turbinate epithelia. Increased sodium absorption is consistent with the hypothesis that epithelial fluid absorption contributes to the development of nasal polyps and is a result of the increased recruitment of inflammatory cells, which are present in nasal polyps.

Middle Ear Mucin Glycoprotein: Purification and Interaction with Nontypable Haemophilus Influenzae and Moraxella Catarrhalis

Nontypable Haemophilus influenzae and Moraxella catarrhalis are important pathogens in children and adults. The mechanisms of their adherence to the epithelial cell surface and colonization are not clear. For the pathogen to adhere to the epithelial cell, it must first attach to and penetrate the mucus barrier. Mucin glycoproteins of the mucus layer generally are thought to be involved in bacterial attachment. To understand the precise mechanisms of middle ear mucin-bacterial interactions, we used an overlay binding assay with a highly purified middle ear mucin and outer membrane proteins of both nontypable H. influenzae and M. catarrhalis. Outer membrane proteins P2 and P5 were identified as the major components that mediate the binding between nontypable H. influenzae and human middle ear mucin. Moreover, the 57 kDa protein, CD, of the outer membrane protein of M. catarrhalis was found to be the only protein binding human middle ear mucin. Finally, it appears that a protein-oligosaccharide interaction is responsible for binding because asialo-mucin does not bind to either of the bacteria. Knowledge of the specific bacterial-mucin interaction may provide an understanding of the bacterial-epithelial cell colonization. Conversely, comprehension of this interaction between bacteria and purified mucin may be a strategy to prevent colonization of potential pathogens that cause otitis media and sinusitis in children.

Further observations on the role of the MHC genes and certain hearing disorders

The pathogenetic mechanism of many hearing disorders have not been fully defined. Studies of certain hearing disorders in man have suggested a role for the major histocompatibility complex (MHC)-encoded genes in disease pathogenesis. In a cohort of unrelated patients with Meniere's Disease, otosclerosis and strial presbycusis as well as other types of sensorineural hearing losses, we have identified an extended MHC haplotype common to the majority of these patients, supporting a hypothesis that a gene(s) within the MHC domain may confer susceptibility to these hearing ailments. In addition, a preliminary study of 27 individuals with various hearing maladies, a striking finding is that 44% of the patients express the following extended MHC haplotype in contrast to only 7% of the general population: DQw2-DR3-C4BSf-C4A0-G11:15-Bf:0.4-C2a-HSP70:7.5-TNF a5-B8-Cw7-A1. The expression of this haplotype by subsets of patients with hearing loss is significant in comparison to regional and international controls.

Morphologic and motility changes of nasal cilia in primary culture caused by Haemophilus influenzae

We focused on the pathogenicity of otitis media with effusion (OME) with respect to the susceptibility of the upper respiratory tract mucosa to Haemophilus influenzae. Human nasal polyps in outgrowth culture were used to study H influenzae disturbance of the ciliary beat frequency (CBF) and the morphology of cilia. The CBF of control primary culture was 11.7 +/- 2.7 Hz. The CBF slowed down significantly, to 8.5 +/- 5.7 Hz, after incubation with the filtrate of 10(8) CFU/mL of H influenzae, and to 4.1 +/- 4.1 Hz with a suspension of 10(8) CFU/mL of H influenzae (p<.05). In the morphologic study, we classified the shapes of the cilia into five types: normal cilia, immotile cilia, swollen cilia, clumped cilia, and exfoliated ciliated cells. The abnormal shapes of cilia increased after incubation with the suspension or the filtrate of H influenzae. By scanning electron microscopy, we saw that aggregated bacteria tended to associate with cilia. Thus, the findings suggest that H influenzae disturbs the ciliary clearance of nasal cells and makes them more susceptible to infections.

Role of allergy in eustachian tube blockage and otitis media with effusion: a review

Recent studies continue to support a role for allergy in the pathogenesis of otitis media with effusion. Although a variety of mechanisms have been proposed to relate these two disease conditions causally, none has been completely validated by experimental or clinical studies. This review suggests that the observed relationship between allergy and otitis media with effusion is caused by mediators of inflammation and cytokines and colony-stimulating factors released by mucosal mast cells and other inflammatory and epithelial cells in the nose and nasopharynx. These mediators produce blockage of the eustachian tube through a number of mechanisms, which may include local injury or vascular- or neural-mediated changes in the eustachian tube opening pressure and in middle ear perfusion. It is likely that the nasal allergic response in patients predisposes to eustachian tube blockage and, if prolonged, causes changes in gas absorption in the middle ear space. This gas exchange primarily involves nitrogen absorption, which may take several days to develop. This persistent underpressure will then lead to middle ear effusion. Irrespective of the theoretical mechanism, the relationship between allergy and otitis media with effusion will remain controversial until well-controlled clinical studies are conducted documenting that in select populations antiallergy therapy is efficacious in preventing or limiting the duration of otitis media with effusion.

Role of Allergy in Eustachian Tube Blockage and Otitis Media with Effusion: A Review

Recent studies continue to support a role for allergy in the pathogenesis of otitis media with effusion. Although a variety of mechanisms have been proposed to relate these two disease conditions causally, none has been completely validated by experimental or clinical studies. This review suggests that the observed relationship between allergy and otitis media with effusion is caused by mediators of inflammation and cytokines and colony-stimulating factors released by mucosal mast cells and other inflammatory and epithelial cells in the nose and nasopharynx. These mediators produce blockage of the eustachian tube through a number of mechanisms, which may include local injury or vascular- or neural-mediated changes in the eustachian tube opening pressure and in middle ear perfusion. It is likely that the nasal allergic response in patients predisposes to eustachian tube blockage and, if prolonged, causes changes in gas absorption in the middle ear space. This gas exchange primarily involves nitrogen absorption, which may take several days to develop. This persistent underpressure will then lead to middle ear effusion. Irrespective of the theoretical mechanism, the relationship between allergy and otitis media with effusion will remain controversial until well-controlled clinical studies are conducted documenting that in select populations antiallergy therapy is efficacious in preventing or limiting the duration of otitis media with effusion.

Binding between outer membrane proteins of nontypeable Haemophilus influenzae and human nasopharyngeal mucin

Bacterial colonization of the epithelial cells precedes infection. Mucins of the epithelial cell secretions modulate bacterial colonization. This study was designed to understand the mechanism of mucin-bacterial interactions and in particular binding between nontypeable Haemophilus influenzae and nasopharyngeal mucin(s). In an overlay assay, binding appears to be mediated by outer membrane proteins P2 and P5 of bacteria and sialic acid-containing oligosaccharides of mucin.

Adenoid lymphocyte responses to outer membrane protein P6 of nontypable Haemophilus influenzae in children with and without otitis media

The cellular immune responses to nontypable Haemophilus influenzae in adenoids were determined in children by measuring lymphocyte blast transformation and antibody secretion in response to the P6 outer membrane protein. In the lymphocyte transformation assay, stimulation index of adenoid lymphocytes stimulated by P6 in otitis children (2.34 +/- 0.25) was significantly lower than that in non-otitis children (3.91 +/- 0.64, p <0.05). The number of IgM as well as IgA secreting cells after 8 days' culture with P6 were significantly smaller in otitis children (IgM: 7,534 +/- 2,843/10(6) lymphocyte; IgA: 1,573 +/- 620/10(6) lymphocyte) than those in non-otitis children (IgM: 12,994 +/- 2,533, p <0.05; IgA: 2,828 +/- 528, p <0.05). These data suggest that P6 protein is a target for the cellular immune response of the adenoid, and failure of adenoid lymphocytes to recognize it as a specific immunogen may be one of the causes of recurrent otitis media.

Role of allergy in nasal polyposis: a review

We propose a multivariate theory for the pathogenesis of nasal polyps. Turbulent flow of air in the lateral wall of the nose or viral-bacterial-host interactions produce an inflammatory change in the mucosa of the lateral wall of the nose. Ulceration and prolapse of the submucosa with reepithelialization and new gland formation may then follow. The structural cells of the nasal polyp, including epithelial cells and fibroblasts, have the ability to produce messenger RNA for granulocyte-monocyte colony-stimulating factor and other cytokines. Stimulation of such an effector capability by structural cell-derived cytokines would undoubtedly represent a major amplification pathway of the inflammatory response in nasal polyps. Allergy may be one mechanism for the development of this cascade of events. This microenvironmental structural inflammatory response in the nasal polyp, in turn, can affect the bioelectric integrity of the Na+ and Cl- channels at the luminal surface of the respiratory epithelial cell. The change in the Na+ absorption, which has been demonstrated in our studies, may result in an increased movement of water into the cell and into the interstitial fluid. The resultant edema can lead to growth and enlargement of the nasal polyp. Finally, the rapid recurrence of nasal polyps despite adequate surgery may reflect some intrinsic phenotypic characteristic of nasal epithelial cells in the lateral wall of the nose, which is likely to be under genetic control.

Increased ion transport in cultured nasal polyp epithelial cells

OBJECTIVE

To measure transepithelial bioelectric properties of cultured human nasal polyp and turbinate epithelial cells to test the hypothesis that nasal polyps have increased rates of ion transport.

DESIGN

Cohort study.

SETTING

Private referral center.

PATIENTS

Individuals undergoing surgery for symptomatic nasal obstruction due to polyps caused by cystic fibrosis, nonatopic rhinosinusitis, or allergic rhinosinusitis.

METHODS

Epithelial cells were removed from separated polyp and turbinate samples by protease disaggregation and cultured on permeable collagen matrix supports. Transepithelial potential difference and resistance were measured daily. At the time of maximal transepithelial potential difference, the cultures were mounted in modified Ussing chambers and exposed to a sodium-positive channel blocker (amiloride hydrochloride) and to selected chloride-negative channel agonists (isoproterenol bitartrate, adenosine triphosphate).

OUTCOME MEASURES

Maximal transepithelial potential difference, resistance, and equivalent short-circuit current. Bioelectric responses to amiloride, isoproterenol, and adenosine triphosphate.

RESULTS

Polyp cultures had higher transepithelial potential difference and equivalent short-circuit current than turbinate cultures. The mediator responses were greater for polyp than for turbinate cultures.

CONCLUSIONS

Polyp epithelia have increased Na+ absorption and Cl- permeability relative to turbinate epithelia. These results are consistent with the hypothesis that increased epithelial fluid absorption contributes to the development of nasal polyps.

Involvement of the eyebrow fat pad in Graves' orbitopathy

Involvement of the eyebrow fat pad in Graves' disease has never been reported. We noted that Graves' orbitopathy patients had bulkier eyebrows due to a larger eyebrow fat pad not associated with the preaponeurotic fat. A cadaver model was used to show that the eyebrow fat could be identified with magnetic resonance imaging (MRI) scans. Then, a series of Graves' orbitopathy patients were sent for orbital MRI scans, and the eyebrow fat was measured with maximum lengths and widths. The averages were compared to two groups of patients, one without orbital pathology, and one with orbital pathology causing proptosis but not due to Graves' disease. Graves' patients with early orbitopathy and incipient optic neuropathy or congestive orbits where optic neuropathy had to be ruled out had statistically significant larger eyebrow fat pads than either comparison group. This has clinical significance: The eyebrow fat may need to be debulked during operations such as blepharoplasty. Furthermore, periorbital fat may play a larger role in the disease process than previously thought.

Analysis of respiratory syncytial virus F, G, and SH proteins in cell fusion

Recombinant expression of the human respiratory syncytial virus (RSV) fusion (F) glycoprotein, receptor-binding glycoprotein (G), and small hydrophobic (SH) protein was performed to determine the role(s) of these proteins in syncytia formation. These studies used a vaccinia virus expressing the bacteriophage (T7) RNA polymerase gene and plasmid vectors containing the RSV genes under the control of a T7 promoter. Within the context of this expression system, expression of any individual RSV gene, or coexpression of F+G genes, did not elicit the formation of syncytia. However, at plasmid input levels which were 10-fold higher than those normally used, coexpression of F+G induced low but detectable levels of cell fusion. In contrast, coexpression of F, G, and SH together elicited extensive cell fusion resembling that of an authentically infected cell monolayer. In addition, coexpression of F and SH elicited significant cell fusion, although to a lesser extent than was observed when G was included. Cell fusion induced by coexpression of F+SH was found to be specific to the RSV proteins, since coexpression of SH with the analogous F proteins from human parainfluenza virus type 3, human parainfluenza virus type 2, Sendai virus, or simian virus type 5 (SV5) did not elicit cell fusion. Finally, coexpression of the SV5 SH protein with the RSV or SV5 glycoproteins also failed to induce syncytia, suggesting type-specific restrictions between the two sets of viral proteins.

Role of IgE-mediated hypersensitivity in otitis media with effusion: pathophysiologic considerations

A pathophysiologic model of otitis media with effusion secondary to IgE-mediated hypersensitivity is described. Specific mediators of inflammation are released by mucosal mast cells in the nasal mucosa following the interaction of antigen and specific IgE antibody. These mediators increase vascular permeability, mucosal blood flow, and, most important, mucus production. Furthermore, accessory cell types are recruited by colony-stimulating factors that in turn provide an autocrine-positive feedback for the influx of further inflammatory cells. The eustachian tube is then effectively obstructed by both intrinsic venous engorgement and extrinsic mucus plugs, isolating the middle ear space from the ambient environment. The net result is the increased exchange of nitrogen into the middle ear mucosa from the middle ear cavity. This causes the development of a significant middle ear underpressure that disrupts tight junctions and allows for transudation of fluids into the middle ear space. The prolonged obstruction of the eustachian tube with mucus results in middle ear inflammation, mucosal metaplasia, and increased glandular activities, all of which are hallmarks of chronic otitis media with effusion.

Are thymus-derived lymphocytes (T cells) defective in the nasopharyngeal and palatine tonsils of children?

The present study was conducted to evaluate the response of adenoidal T cells and B cells in the production of immunoglobulins. There appears to be a consistent inability of adenoidal T cells to turn on B cells to mature into immunoglobulin-secreting plasma cells. This phenomenon did not appear to be due to suppressor activity of adenoidal T cells because T cells from other sources appeared to effectively result in adenoidal B cell maturation, even in the presence of adenoidal T cells. Both tonsils and adenoids appear to have defective IL-2 production, in response to both mitogens and specific antigens. It is hypothesized that a cytokine(s) may be released in adenoids that downregulate IL-2 production and result in immune suppression in the adenoids of children with recurrent otitis media and chronic sinusitis.