The role of magnetic resonance imaging in the assessment of suspected extrinsic tracheobronchial compression due to vascular anomalies.

AIMS: To evaluate the role of magnetic resonance imaging (MRI) in the assessment of children with suspected extrinsic tracheobronchial compression due to vascular anomalies. METHODS: Retrospective case note review in a tertiary referral centre. Twenty nine children who underwent dynamic laryngotracheobronchoscopy (DLTB) and were found to have a clinical suspicion of extrinsic tracheobronchial compression were evaluated. All subsequently underwent thoracic MRI within 10 days. The findings on endoscopy were compared to those of MRI, and where performed, echocardiography, aortography, and surgery. RESULTS: There were 17 males and 12 females (mean age 5 months, range 28 weeks gestation to 60 months). The most common presenting features were stridor and cyanotic episodes. MRI showed abnormalities in 21 patients. There were five vascular rings (three double aortic arches and two right aortic arches) and 11 cases of innominate artery compression. Other vascular anomalies noted included aberrant right subclavian artery and aneurysmal left pulmonary artery. Echocardiography was generally found to be unhelpful in the diagnosis of extra-cardiac vascular abnormalities. Angiography was subsequently conducted in eight children; findings agreed with those shown on MRI. Surgery was performed on all five vascular rings, one innominate artery compression, and one aneurysmal left pulmonary artery. Surgical findings were also compatible with the preoperative MRI. CONCLUSIONS: This study shows the successful use of MRI as the initial imaging modality in endoscopically suspected extrinsic vascular compression of the upper airway. It enables accurate delineation of vascular anomalies and, unlike aortography, is non-invasive and does not require the use of contrast media.

Randomized controlled trial comparing Merocel and RapidRhino packing in the management of anterior epistaxis.

OBJECTIVES: A prospective non-blinded randomized controlled trial to compare the efficacy of Merocel and RapidRhino nasal packs in the treatment of anterior epistaxis. METHODS: Fifty-two consecutive participants admitted with anterior epistaxis refractory to digital pressure or nasal cautery were randomized to treatment using one or other of the nasal packs. Patients who required repacking because of continued bleeding, only the first packs were included in the analysis. Haemostatic properties of the packs were measured by grading bleeding during and after removal of the pack (0-4, where four is uncontrollable) and by noting if the nose was re-packed or not. The difficulty of insertion and removal (graded 0-3 by clinician where 3 is the most difficult) and the participant's perception of discomfort (graded 0-10, where 10 is the worst pain) during insertion and removal of the pack were also measured. RESULTS: For bleeding, the mean values for Merocel and RapidRhino during packing and after pack removal were not significant (P = 0.38 and 0.82 respectively). The mean values of patient discomfort on insertion were 6.9 and 5.0 (P = 0.01), and for discomfort on removal were 4.6 and 3.4 (P = 0.05) respectively. The mean values of insertion graded by the clinician were 1.7 and 0.9 (P = 0.0003), and for removal were 1.4 and 0.4 (P < 0.0001). CONCLUSIONS: RapidRhino and Merocel are equally effective in the control of anterior epistaxis but RapidRhino is significantly more comfortable for the patient and easier for the healthcare worker during insertion and removal.

A quantitative determination of multi-protein interactions by the analysis of confocal images using a pixel-by-pixel assessment algorithm.

MOTIVATION: Recent advances in confocal microscopy have allowed scientists to assess the expression, and to some extent, the interaction/colocalization of multiple molecules within cells and tissues. In some instances, accurately quantifying the colocalization of two or more proteins may be critical. This can require the acquisition of multiple Z plane images (Z stacks) throughout a specimen and, as such, we report here the successful development of a freeware, open-source image analysis tool, IMAJIN_COLOC, developed in PERL (v. 5.8, build 806), using the PERLMagick libraries (ImageMagick). Using a pixel-by-pixel analysis algorithm, IMAJIN_COLOC can analyze images for antigen expression (any number of colors) and can measure all possible combinations of colocalization for up to three colors by analyzing a Z stack gallery acquired for each sample. The simultaneous (i.e. in a single pass) analysis of three-color colocalization, and batch analysis capabilities are distinctive features of this program. RESULTS: A control image, containing known individual and colocalized pixel counts, was used to validate the accuracy of IMAJIN_COLOC. As further validation, pixel counts and colocalization values from the control image were compared to those obtained with the software packaged with the Zeiss laser-scanning microscope (LSM AIM, version 3.2). The values from both programs were found to be identical. To demonstrate the applicability of this program in addressing novel biological questions, we examined the role of neurons in eliciting an immune reaction in response to viral infection. Specifically, we successfully examined expression of the chemokine RANTES in measles virus (MV) infected hippocampal neurons and quantified changes in RANTES production throughout the disease period. The resultant quantitative data were also evaluated visually, using a gif image created during the analysis. AVAILABILITY: PERL (ActivePerl, version 5.8) is available at activestate.com; the PERLMagick libraries are available at imagemagick.org, and IMAJIN_COLOC, the source code and user documentation can be downloaded from http://www.fda.gov/cber/research/imaging/imageanalysis.htm.

Expression of somatostatin receptors in arginine vasopressin hormone-secreting olfactory neuroblastoma--report of two cases.

OBJECTIVE: Arginine vasopressin hormone-secreting olfactory neuroblastomas are extremely rare, with fewer than twenty cases reported in the literature. Two of these cases, both initially presenting with the syndrome of inappropriate antidiuretic hormone, are presented. The second tumour was successfully identified using somatostatin receptor (octreotide) radiographic scintography. METHOD: The pathological specimens from both cases were examined immunohistochemically for somatostatin receptors. RESULTS: Samples from both cases demonstrated positivity for somatostatin receptors. CONCLUSIONS: This report demonstrates the potential use of somatastatin analogues in the investigation, follow-up and treatment of patients with olfactory neuroblastoma.

Histiocytic necrotising lymphadenitis (Kikuchi's disease): a rare cause of cervical lymphadenopathy.

Both Head and Neck Surgeons and General Surgeons are frequently referred patients with cervical lymphadenopathy. An uncommon but important cause is histiocytic necrotising lymphadenitis. This is a benign self-limiting disease that has been confused with malignant lymphomas. Some patients may also experience distressing and debilitating symptoms which can last for months. We describe four cases to illustrate the varied clinical presentation of this disease and present new signs seen in association with it. A remarkable therapeutic response to a short course of oral corticosteroids was observed in one case.

Transient quadriplegia following re-puncture of tracheo-oesophageal fistula.

We present a case of a laryngectomized patient who underwent re-puncture of tracheo-oesophageal fistula for speaking valve voice restoration, resulting in a previously unreported inherent complication of this procedure: extradural abscess of the cervical spine with transient quadriplegia.

Transcriptional repression and developmental functions of the atypical vertebrate GATA protein TRPS1.

Known vertebrate GATA proteins contain two zinc fingers and are required in development, whereas invertebrates express a class of essential proteins containing one GATA-type zinc finger. We isolated the gene encoding TRPS1, a vertebrate protein with a single GATA-type zinc finger. TRPS1 is highly conserved between Xenopus and mammals, and the human gene is implicated in dominantly inherited tricho-rhino-phalangeal (TRP) syndromes. TRPS1 is a nuclear protein that binds GATA sequences but fails to transactivate a GATA-dependent reporter. Instead, TRPS1 potently and specifically represses transcriptional activation mediated by other GATA factors. Repression does not occur from competition for DNA binding and depends on a C-terminal region related to repressive domains found in Ikaros proteins. During mouse development, TRPS1 expression is prominent in sites showing pathology in TRP syndromes, which are thought to result from TRPS1 haploinsufficiency. We show instead that truncating mutations identified in patients encode dominant inhibitors of wild-type TRPS1 function, suggesting an alternative mechanism for the disease. TRPS1 is the first example of a GATA protein with intrinsic transcriptional repression activity and possibly a negative regulator of GATA-dependent processes in vertebrate development.

Prevalence of circulating antibodies to p10, a non-structural protein of the Borna disease virus in cats with ataxia.

Japanese domestic cats were surveyed for circulating antibodies to the plO and p24 proteins of the Borna disease virus (BDV) by Western blotting. Twenty-four of 52 cats (46.2%) with ataxia and other neurologic symptoms of unknown cause were positive for antibodies to BDV p10 and/or p24. In contrast, cats without neurological symptoms gave a significantly lower prevalence of anti-BDV antibodies to p10 and/or p24 (36 of 152 cats, 23.7%). Thirty specific pathogen-free (SPF) cats tested as controls were uniformly negative to BDV pl0 and p24 antigens. These results suggest that BDV may play a role in ataxia in cats. Additionally, our results suggest that it is necessary to use both p10 and p24 as antigens to detect circulating antibodies to BDV in cats.

Incidental findings on magnetic resonance imaging screening for cerebellopontine angle tumours.

The otolaryngologist who requests magnetic resonance imaging (MRI) scans to exclude cerebellopontine angle (CPA) tumours may discover incidental pathologies. We retrospectively reviewed the results of 644 consecutive MRI screening scans with the aim of identifying findings other than CPA tumours. Two hundred and eighty-nine (45 per cent) scans featured one or more anomalies or abnormalities, including CPA tumour (23, four per cent), vascular loop (30, five per cent), basilar artery ectasia (13, two per cent), multiple high signal areas (135,21 per cent), brain atrophy (52, eight per cent), sinus findings (56, nine per cent), middle ear/mastoid disease (34, five per cent), and a variety of other findings (39, six per cent) including clinically serious lesions (11, two per cent). The significance and management of these incidental findings is discussed. The majority were not clinically significant but the occasional presence of a serious incidental pathology should be borne in mind. Basilar artery ectasia and multiple high signal areas may be responsible for the symptoms investigated by MRI, and screening for cerebrovascular disease risk factors in such patients may be appropriate.

Structure and expression of a novel frizzled gene isolated from the developing mouse gut.

The Wnt/APC (adenomatous polyposis coli)/beta-catenin pathway plays a central role in the pathogenesis of colorectal cancer and probably also in normal development of the gastrointestinal tract. Frizzled proteins function as cell-surface receptors for the Wnt family of extracellular ligands. Many components of the Wnt signalling pathway are expressed widely, and determinants of tissue-specific functions are poorly understood. A better understanding of how Wnt signalling regulates tissue-specific development and gut epithelial homoeostasis requires characterization of the many components of this signalling pathway. We therefore wished to identify frizzled genes with limited tissue distribution of expression and isolated Mfz10, a novel member of the mouse family of frizzled genes, from the developing fetal gut. Highest levels of Mfz10 mRNA are detected throughout late embryonic development, in the brain, heart, lung and digestive tract. In adult mice Mfz10 mRNA is detected at highest levels in the heart, brain and lung. Expression in the adult gastrointestinal tract is much weaker, with higher levels in foregut derivatives (oesophagus and stomach) compared with regions derived from the fetal midgut and hindgut; particularly strong mRNA expression is observed in the squamous epithelium of the oesophagus. The amino acid sequence of Mfz10 is nearly identical to that of human FzE2 (also known as FzD2). Interestingly, mRNA levels of human FzD2 are reported to be up-regulated in oesophageal squamous cell carcinomas. These findings suggest a likely role for Mfz10 in the developing and adult foregut.

Action of the Caenorhabditis elegans GATA factor END-1 in Xenopus suggests that similar mechanisms initiate endoderm development in ecdysozoa and vertebrates.

In ecdysozoan protostomes, including arthropods and nematodes, transcription factors of the GATA family specify the endoderm: Drosophila dGATAb (ABF/Serpent) and Caenorhabditis elegans END-1 play important roles in generating this primary germ layer. end-1 is the earliest expressed endoderm-specific gene known in C. elegans and appears to initiate the program of gene expression required for endoderm differentiation, including a cascade of GATA factors required for development and maintenance of the intestine. Among vertebrate GATA proteins, the GATA-4/5/6 subfamily regulates aspects of late endoderm development, but a role for GATA factors in establishing the endoderm is unknown. We show here that END-1 binds to the canonical target DNA sequence WGATAR with specificity similar to that of vertebrate GATA-1 and GATA-4, and that it functions as a transcriptional activator. We exploited this activity of END-1 to demonstrate that establishment of the vertebrate endoderm, like that of invertebrate species, also appears to involve GATA transcriptional activity. Like the known vertebrate endoderm regulators Mixer and Sox17, END-1 is a potent activator of endoderm differentiation in isolated Xenopus ectoderm. Moreover, a dominant inhibitory GATA-binding fusion protein abrogates endoderm differentiation in intact embryos. By examining these effects in conjunction with those of Mixer- and Sox17beta-activating and dominant inhibitory constructs, we further establish the likely relationships between GATA activity and these regulators in early development of the vertebrate endoderm. These results suggest that GATA factors may function sequentially to regulate endoderm differentiation in both protostomes and deuterostomes.

Characterization of the P protein-binding domain on the 10-kilodalton protein of Borna disease virus.

The Borna disease virus (BDV) is the prototype member of the Bornaviridae, and it replicates in the cell nucleus. The BDV p24P and p40N proteins carry nuclear localization signals (NLS) and are found in the nuclei of infected cells. The BDV p10 protein does not have an NLS, but it binds with P and/or N and is translocated to the nucleus. Hence, p10 may play a role in the replication of BDV in the cell nucleus. Here, we show that the P-binding domain is located in the N terminus of p10 and that S(3) and L(16) are important for the interaction.

Nuclear localization of the protein from the open reading frame x1 of the Borna disease virus was through interactions with the viral nucleoprotein.

Previous studies have predicted the presence of a small open reading frame (ORFx1) located between ORF-1 and ORF-2 of the Borna disease viral (BDV) genome. The ORFx1 is expressed as a p10 protein that is localized in the nucleus and cytoplasm of BDV-infected cells. In this study, we cloned the nucleotide sequence of ORFx1 into expression vectors and showed that it is expressed as p10. An anti-p10 serum gave nuclear and cytoplasmic staining of cells persistently infected with BDV. Immunoprecipitation of p10 from BDV-infected cells coprecipitated the p40 nucleoprotein N and the 24-kDa viral phosphoprotein P. Transient transfection of noninfected cells showed that p10 and p40 can be coprecipitated and revealed that p10 localized in the cytoplasm was imported into the nucleus in the presence of the BDV p40 N. In vitro protein-protein interaction studies on solid phase showed the direct interaction of the p10 with the BDV N protein. The subcellular distribution of p10 and its interaction with p40 suggest that this protein may play a role in the nuclear replication and/or transcription of BDV.

The use of inhalers in patients with tracheal stomas or tracheostomy tubes.

Patients with chronic obstructive airways disease (COAD) or asthma who have a tracheostomy tube or tracheal stoma have difficulty using metered dose inhalers (MDIs) because of a failure to achieve a good seal between the tracheostomy tube or stoma and the MDI or spacer device mouthpiece. Many such patients therefore utilize nebulizers. MDIs in comparison to nebulizers have the advantages of being more compact, portable, easy to use, less time-consuming, and cheaper. We present the case of a 74-year-old man who underwent a laryngectomy with tracheal stoma formation who had a poor response with nebulizers and required oral steroids. He was subsequently, with the help of a number of attached devices, able to use his MDIs to good effect. We describe a number of devices and adaptors to enable patients with laryngectomy stomas or tracheostomy tubes to utilize MDIs and undergo respiratory function tests. We recommend that all such patients should have the benefit of a consultation with a dedicated respiratory nurse who can provide the appropriate MDIs, devices and adaptors to optimize the treatment of their lower respiratory tract condition.