Microsatellite instability and the clinicopathological features of sporadic colorectal cancer

BACKGROUND AND AIMS

In this study, we prospectively examined the clinical significance of the microsatellite instability (MSI) phenotype in sporadic colorectal cancer, and investigated methods for effective identification of these tumours in routine pathology practice.

METHODS

DNA was extracted from 310 tumours collected from 302 consecutive individuals undergoing curative surgery for sporadic colorectal cancer. Microsatellite status was determined by polymerase chain reaction amplification using standard markers, while immunostaining was used to examine expression of MLH1, MSH2, and p53.

RESULTS

Eleven per cent of tumours showed high level instability (MSI-H), 6.8% had low level instability (MSI-L), and the remainder were stable. MSI-H tumours were significantly more likely to be of high histopathological grade, have a mucinous phenotype, and to harbour increased numbers of intraepithelial lymphocytes. They were also more likely to be right sided, occur in women, and be associated with improved overall survival. In total, 25 (8%) tumours showed loss of staining for MLH1 and a further three tumours showed absence of staining for MSH2. The positive and negative predictive value of immunohistochemistry in the detection of MSI-H tumours was greater than 95%.

CONCLUSIONS

We conclude that the MSI-H phenotype constitutes a pathologically and clinically distinct subtype of sporadic colorectal cancer. Immunohistochemical staining for MLH1 and MSH2 represents an inexpensive and accurate means of identifying such tumours.

Linkage disequilibrium in the human genome

With the availability of a dense genome-wide map of single nucleotide polymorphisms (SNPs), a central issue in human genetics is whether it is now possible to use linkage disequilibrium (LD) to map genes that cause disease. LD refers to correlations among neighbouring alleles, reflecting 'haplotypes' descended from single, ancestral chromosomes. The size of LD blocks has been the subject of considerable debate. Computer simulations and empirical data have suggested that LD extends only a few kilobases (kb) around common SNPs, whereas other data have suggested that it can extend much further, in some cases greater than 100 kb. It has been difficult to obtain a systematic picture of LD because past studies have been based on only a few (1-3) loci and different populations. Here, we report a large-scale experiment using a uniform protocol to examine 19 randomly selected genomic regions. LD in a United States population of north-European descent typically extends 60 kb from common alleles, implying that LD mapping is likely to be practical in this population. By contrast, LD in a Nigerian population extends markedly less far. The results illuminate human history, suggesting that LD in northern Europeans is shaped by a marked demographic event about 27,000-53,000 years ago.

Linkage and association analysis of angiotensin I-converting enzyme (ACE)-gene polymorphisms with ACE concentration and blood pressure

Considerable effort has been expended to determine whether the gene for angiotensin I-converting enzyme (ACE) confers susceptibility to cardiovascular disease. In this study, we genotyped 13 polymorphisms in the ACE gene in 1,343 Nigerians from 332 families. To localize the genetic effect, we first performed linkage and association analysis of all the markers with ACE concentration. In multipoint variance-component analysis, this region was strongly linked to ACE concentration (maximum LOD score 7.5). Likewise, most of the polymorphisms in the ACE gene were significantly associated with ACE (P<.0013). The two most highly associated polymorphisms, ACE4 and ACE8, accounted for 6% and 19% of the variance in ACE, respectively. A two-locus additive model with an additive x additive interaction of these polymorphisms explained most of the ACE variation associated with this region. We next analyzed the relationship between these two polymorphisms (ACE4 and ACE8) and blood pressure (BP). Although no evidence of linkage was detected, significant association was found for both systolic and diastolic BP when a two-locus additive model developed for ACE concentration was used. Further analyses demonstrated that an epistasis model provided the best fit to the BP variation. In conclusion, we found that the two polymorphisms explaining the greatest variation in ACE concentration are significantly associated with BP, through interaction, in this African population sample. Our study also demonstrates that greater statistical power can be anticipated with association analysis versus linkage, when markers in strong linkage disequilibrium with a trait locus have been identified. Furthermore, allelic interaction may play an important role in the dissection of complex traits such as BP.

Courtship song genes and speciation in sand flies

Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) is a vector of visceral leishmaniasis in the Americas and it might represent a complex of sibling species. Reproductive isolation between closely related species often involves differences in courtship behaviour. cacophony (cac) and period (per) are two Drosophila genes that control features of the "lovesong" males produce during courtship that has been implicated in the sexual isolation between closely related species. We are using gene fragments from L. longipalpis' homologues of these two genes to study the speciation process in this putative species complex.

Environmentally defined frames of reference: their time course and sensitivity to spatial cues and attention

In a Simon task the effects of spatial cues and attention on spatial stimulus coding were explored. Participants made speeded responses corresponding to the direction of target arrows that were preceded by peripherally presented cues. Cue validity varied across experiments as did the percentage of trials on which the target appeared peripherally or centrally. The data indicate (a) that targets are coded relative to multiple reference frames, (b) that spatial coding of a target is not affected when attention is shifted to the target, and (c) that an object serves as a referent for spatial coding of other objects even after its spatial code no longer activates responses.

Electrolytic ablation of colorectal liver metastases: 1-year histological patient follow-up

Whilst up to 50% of patients with colorectal carcinoma will develop liver metastases, only 20% of those patients will be amenable to potentially curative liver resection. There is therefore great need for other effective therapies, and we report complete ablation of a colorectal liver metastasis using electrolysis, which was histologically confirmed at 1 year. The clinical impact of complete tumour ablation at 1 year means that a proportion of those patients currently deemed inoperable and therefore incurable, may be suitable for curative treatment.

Asthmagenicity of coal mine roof-bolting resins: an assessment using inhalation provocation tests

Inhalation provocation tests were used to assess whether the volatile products of an activated resin had caused occupational asthma in a non-random sample of six asthmatic coal miners. The resin system uses the polymerization of polyester and styrene under the influence of the cross-linking agent dibenzoyl peroxide to secure roof, wall and floor bolts in mine tunnels. The tests were conducted sequentially in a double-blind fashion over a 'dose' range which extended just beyond the maximum likely to have been experienced occupationally during a single day's work. The tests were monitored by symptoms, changes in the forced expiratory volume in 1 s (FEV1) and changes in airway responsiveness. All subjects completed the series of tests without any significant decrements in FEV1 or significant increases in airway responsiveness. We conclude that the use of this resin system is not likely to have been the cause of the asthma in the test subjects, nor in the larger group of miners of which they were a sample, but neither possibility is fully excluded and the participants may not have been adequately representative of other asthmatic coal miners.

mtDna and the islands of the North Atlantic: estimating the proportions of Norse and Gaelic ancestry

A total of 1,664 new mtDNA control-region sequences were analyzed in order to estimate Gaelic and Scandinavian matrilineal ancestry in the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye and to investigate other aspects of their genetic history. A relative excess of private lineages in the Icelanders is indicative of isolation, whereas the scarcity of private lineages in Scottish island populations may be explained by recent gene flow and population decline. Differences in the frequencies of lineage clusters are observed between the Scandinavian and the Gaelic source mtDNA pools, and, on a continent-wide basis, such differences between populations seem to be associated with geography. A multidimensional scaling analysis of genetic distances, based on mtDNA lineage-cluster frequencies, groups the North Atlantic islanders with the Gaelic and the Scandinavian populations, whereas populations from the central, southern, and Baltic regions of Europe are arranged in clusters in broad agreement with their geographic locations. This pattern is highly significant, according to a Mantel correlation between genetic and geographic distances (r=.716). Admixture analyses indicate that the ancestral contributions of mtDNA lineages from Scandinavia to the populations of Iceland, Orkney, the Western Isles, and the Isle of Skye are 37.5%, 35.5%, 11.5%, and 12.5%, respectively.

Complete mitochondrial genome sequences of two extinct moas clarify ratite evolution

The origin of the ratites, large flightless birds from the Southern Hemisphere, along with their flighted sister taxa, the South American tinamous, is central to understanding the role of plate tectonics in the distributions of modern birds and mammals. Defining the dates of ratite divergences is also critical for determining the age of modern avian orders. To resolve the ratite phylogeny and provide biogeographical data to examine these issues, we have here determined the first complete mitochondrial genome sequences of any extinct taxa--two New Zealand moa genera--along with a 1,000-base-pair sequence from an extinct Madagascan elephant-bird. For comparative data, we also generated 12 kilobases of contiguous sequence from the kiwi, cassowary, emu and two tinamou genera. This large dataset allows statistically precise estimates of molecular divergence dates and these support a Late Cretaceous vicariant speciation of ratite taxa, followed by the subsequent dispersal of the kiwi to New Zealand. This first molecular view of the break-up of Gondwana provides a new temporal framework for speciation events within other Gondwanan biota and can be used to evaluate competing biogeographical hypotheses.

Internet skills for nurses

As the internet becomes increasingly accessible to more people, it is important to understand its relevance to nursing. Rod Ward discusses its benefits and drawbacks, and the need for evaluating web information.

The distribution of NPY-like immunoreactivity in the chameleon brain

The distribution of neuropeptide Y (NPY) immunoreactivity was studied in the brain of the chameleon. Cell bodies and fibers displaying NPY-like immunoreactivity were widely dispersed throughout the brain and at the highest density in the telencephalon and diencephalon. Immunolabeled cell bodies were numerous in the medial and dorsomedial cortex and in the dorsal ventricular ridge, while the striatum and basal telencephalon only contained sparsely scattered NPY-positive somata. Immunopositive neurons were densely distributed in the dorsal thalamus (particularly in the perirotundal belt), the area triangularis, the nucleus geniculatus lateralis pars dorsalis, the periventricular hypothalamus and the medial eminence. In the pretectum, NPY-immunoreactive cell bodies were limited to the nucleus posterodorsalis, while in the mesencephalon immunolabeled somata were found in the stratum album centrale of the optic tectum and in the substantia nigra. Immunopositive fibers and terminals were particularly dense in the dorsomedial cortex, the periventricular hypothalamus, the nuclei accumbens, suprachiasmaticus and griseus tectalis, in the substantia nigra and in the torus semicircularis. These findings show that the NPY system in the chameleon has the same basic organization as in other vertebrate species, and indicate that this peptide could be also implicated in the regulation of several aspects of cerebral functions. In addition, and of particular interest, is the observation of numerous NPY-immunoreactive neurons and fibers in several visual nuclei, suggesting an important involvement of this substance in the visual function.

Regression of gastric T cell lymphoma with eradication of Helicobacter pylori

Helicobacter pylori is thought to be important in the pathogenesis of chronic active gastritis, peptic ulceration, gastric adenocarcinoma, and gastric B cell lymphoma of mucosa associated lymphoid tissue. The mechanism of evolution from chronic gastritis to monoclonal B cell proliferation is not known but is thought to be dependent on antigen specific T cells to H pylori and its products. Here, we report a case of gastric T cell lymphoma associated with chronic H pylori gastritis which regressed with eradication of the organism. This is the first report of a gastric T cell lymphoma regressing with H pylori eradication, and suggests a causal link between primary gastric T cell lymphoma and this organism.

Commitment to change statements: a way of understanding how participants use information and skills taught in an educational session

BACKGROUND

Commitment to change has gained increasing use in assessing short course effectiveness. This study examined the changes that learners intended to make in practice following an intensive day-long course offered at multiple sites, counted changes relative to the curriculum's focus, and analyzed which changes were implemented in practice.

METHODS

Participants at a course on the management of male sexual dysfunction were asked to identify the changes to which they would commit. Six months after the course, they were asked to indicate which changes they implemented fully, partially, or not at all.

RESULTS

A total of 352 physicians attended the courses held in 21 centers. A majority of attendees (344 or 97.7%) completed forms at the end of the course, providing 1,635 commitment statements. Six months later, 197 (57.3%) physicians provided follow-up data about 935 (55.4%) of the commitment statements originally submitted. Of these, 602 (66.52%) were completely implemented. Many of the changes related to two specific aspects of the course, namely, sexual history taking and medical intervention, accounting for 45.93% of the intended commitments and 47.67% of the changes completely implemented. Slightly over half (58%) of the course time was devoted to these two areas. There was a significant correlation between the number of changes and the amount of time allocated to that content within the course.

FINDINGS

Commitment to change statements offered by course participants can be used to examine the impact of a course relative to its learning focus. Continuing medical education providers must take a critical look at commitment to change statements as an "intervention" in their own right and determine how the tool can best be used as a continuing medical education intervention.

Sputum eosinophilia and short-term response to prednisolone in chronic obstructive pulmonary disease: a randomised controlled trial

BACKGROUND

Some patients with chronic obstructive pulmonary disease (COPD) respond to corticosteroid therapy. Whether these patients have different airway pathology from other COPD patients is unclear. We tested the hypothesis that response to prednisolone is related to the presence of eosinophilic airway inflammation.

METHODS

We did a randomised, double-blind, crossover trial. Patients who had COPD treated with bronchodilators only were assigned placebo and 30 mg prednisolone daily for 2 weeks each, in a random order, separated by a 4-week washout period. Before and after each treatment period, we assessed patients with spirometry, symptom scores, the chronic respiratory disease questionnaire (CRQ), incremental shuttle walk test, and induced sputum. Analysis was done by intention to treat.

FINDINGS

83 patients were recruited, of whom 67 were randomised. The geometric mean sputum eosinophil count fell significantly after prednisolone (from 2.4% to 0.4%; mean difference six-fold [95% CI 3.1-11.4]) but not after placebo. Other sputum cell counts did not change. After stratification into tertiles by baseline eosinophil count, postbronchodilator forced expiratory volume in 1 s (FEV1) and total scores on the CRQ improved progressively after prednisolone from the lowest to the highest eosinophilic tertile, compared with placebo. The mean change in postbronchodilator FEV1, total CRQ score, and shuttle walk distance with prednisolone compared with placebo in the highest tertile was 0.19 L (0.06-0.32), 0.62 (0.31-0.93), and 20 m (5-35), respectively.

INTERPRETATION

Our findings suggest that eosinophilic airway inflammation contributes to airflow obstruction and symptoms in some patients with COPD and that the short-term effects of prednisolone are due to modification of this feature of the inflammatory response. The possibility that sputum eosinophilia identifies a subgroup of patients who particularly respond to long-term treatment with inhaled corticosteroids should be investigated.

Isolation of antibodies which neutralise the activity of early pregnancy factor

Early pregnancy factor (EPF) is a secreted protein with growth regulatory and immunomodulatory properties. It functions as an autocrine growth factor for tumour cells and as an autocrine or paracrine growth factor for regenerating normal cells. Anti-EPF antibodies have demonstrable anti-tumour activity and, as a result, hybridomas which produce such antibodies are unstable. In this study, the phage display antibody techniques have been investigated as a means of producing recombinant anti-EPF antibodies. Mice were immunised with synthetic peptides which correspond to the N or C terminal regions of EPF, and their splenic tissue was used to make combinatorial antibody libraries. The Fab repertoire was displayed on the surface of phage and panned over recombinant EPF. Reactive Fabs were identified by ELISA and their binding was characterised by BIAcore analysis and functional studies. Three libraries with a size of greater than 5x10(7)cfu were constructed and a total of 26 unique Fabs with specific reactivity against EPF were identified. Three Fabs were purified and of these one demonstrated strong EPF neutralising activity, one had intermediate activity and the other was not neutralising. Phage display has provided the means of circumventing the problems of anti-EPF hybridoma development and has resulted in the production of antibodies with potential applications in the diagnosis of pregnancy and the diagnosis and therapy of cancer.

Pretectal connections in turtles with special reference to the visual thalamic centers: a hodological and gamma-aminobutyric acid-immunohistochemical study

Projections of the pretectal region to forebrain and midbrain structures were examined in two species of turtles (Testudo horsfieldi and Emys orbicularis) by axonal tracing and immunocytochemical methods. Two ascending gamma-aminobutyric acid (GABA)ergic pathways to thalamic visual centers were revealed: a weak projection from the retinorecipient nucleus lentiformis mesencephali to the ipsilateral nucleus geniculatus lateralis pars dorsalis and a considerably stronger projection from the nonretinorecipient nucleus pretectalis ventralis to the nucleus rotundus. The latter is primarily ipsilateral, with a weak contralateral component. The interstitial nucleus of the tectothalamic tract is also involved in reciprocal projections of the pretectum and nucleus rotundus. In addition, the pretectal nuclei project reciprocally to the optic tectum and possibly to the telencephalic isocortical homologues. Comparison of these findings with previous work on other species reveals striking similarities between the pretectorotundal pathway in turtles and birds and in the pretectogeniculate pathway in turtles, birds, and mammals.

Estimating Scandinavian and Gaelic ancestry in the male settlers of Iceland

We present findings based on a study of Y-chromosome diallelic and microsatellite variation in 181 Icelanders, 233 Scandinavians, and 283 Gaels from Ireland and Scotland. All but one of the Icelandic Y chromosomes belong to haplogroup 1 (41.4%), haplogroup 2 (34.2%), or haplogroup 3 (23.8%). We present phylogenetic networks of Icelandic Y-chromosome variation, using haplotypes constructed from seven diallelic markers and eight microsatellite markers, and we propose two new clades. We also report, for the first time, the phylogenetic context of the microsatellite marker DYS385 in Europe. A comparison of haplotypes based on six diallelic loci and five microsatellite loci indicates that some Icelandic haplogroup-1 chromosomes are likely to have a Gaelic origin, whereas for most Icelandic haplogroup-2 and -3 chromosomes, a Scandinavian origin is probable. The data suggest that 20%-25% of Icelandic founding males had Gaelic ancestry, with the remainder having Norse ancestry. The closer relationship with the Scandinavian Y-chromosome pool is supported by the results of analyses of genetic distances and lineage sharing. These findings contrast with results based on mtDNA data, which indicate closer matrilineal links with populations of the British Isles. This supports the model, put forward by some historians, that the majority of females in the Icelandic founding population had Gaelic ancestry, whereas the majority of males had Scandinavian ancestry.

Induced sputum inflammatory mediator concentrations in eosinophilic bronchitis and asthma

Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but in contrast to asthma there is no variable airflow obstruction or airway hyperresponsiveness. Our hypothesis was that the differences in airway pathophysiology maybe due to less active airway inflammation in eosinophilic bronchitis, with reduced release of important effector mediators. We measured the concentration of various proinflammatory mediators in induced sputum cell-free supernatant in eight patients with eosinophilic bronchitis, 17 patients with asthma matched for sputum eosinophil count, and 10 normal subjects. Cysteinyl-leukotrienes (cys-LT) were measured by enzyme immunoassay, eosinophilic cationic protein (ECP) by fluoroimmunoassay, prostanoids (PGE(2), PGD(2), TXB(2), and PGF(2alpha)) by gas chromatography-negative ion chemical ionization-mass spectroscopy, and histamine by radioenzymic assay. The geometric mean sputum eosinophil count was similar in asthma (13.4%) and eosinophilic bronchitis (12.5%). Sputum cys-LT and ECP were a mean (95% CI) 1.6-fold (1.1, 2.5) and 6.4-fold (1.4, 28) higher in eosinophilic bronchitis and 1.9-fold (1.3, 2.9) and 7.7-fold (1.2, 46) higher in asthma compared with that in control subjects (geometric mean, 5.9 and 95 ng/ml, respectively). In eosinophilic bronchitis the mean concentration of sputum PGD(2) (0.79 ng/ml) and histamine (168 ng/ml) were significantly higher than in asthma (mean absolute difference in PGD(2) concentration, 0.47 ng/ml [95% CI, 0.19 to 0. 74] and mean-fold difference in histamine concentration, 6.7 [95% CI 1.7 to 26]) and normal subjects (0.64 ng/ml [0.36 to 0.90] and 11-fold [3.3 to 36]), respectively. In conclusion, eosinophilic bronchitis is associated with active airway inflammation with increased release of vasoactive and bronchoconstrictor mediators.

Symmetry, repetition, and figural goodness: an investigation of the weight of evidence theory

Considerable evidence has accumulated on the superiority of symmetry over repetition in the study of figural goodness. The Weight of Evidence theory of figural goodness (WoE) provides a mathematically rigorous, elegant, and testable account of how factors like symmetry and repetition affect figural goodness. In this study we investigate implications of the WoE approach. More specifically, we examine (1) embedded patterns versus simple elements, (2) the number of elements in a pattern, and (3) long-range dependencies within a pattern. Data from two experiments illustrate cases in which figures made of simple repetitions have higher figural goodness than some kinds of symmetrical patterns; thus, the generality of the symmetry over repetition phenomenon is questioned. We discuss our results with respect to WoE and suggest ways to further develop the theory.

Tongue reduction in Beckwith-Weidemann syndrome

OBJECTIVE

To review our experience with patients with macroglossia as a component of Beckwith-Weidemann Syndrome (BWS).

DESIGN

Chart review of six patients treated with BWS.

SETTING

Tertiary care teaching hospital.

PATIENTS

Six patients diagnosed with BWS and macroglossia.

INTERVENTIONS

Four patients underwent at least one surgical procedure to address their macroglossia. The surgical options and potential complications are discussed.

RESULTS

Three patients who have undergone tongue reduction have a functioning tongue with normal mobility. Two patients have required tracheotomy as apart of their management and still have significant tongue enlargement.

CONCLUSIONS

Macroglossia as a part of BWS may present a difficult management problem. Various methods of tongue reductions have been reported with mixed results.

In vitro and in vivo spin echo diffusion imaging characteristics of synovial fluid: potential non-invasive differentiation of inflammatory and degenerative arthritis

OBJECTIVE

This study was undertaken to analyse the diffusion characteristics of synovial fluid in degenerative and inflammatory arthropathies.

DESIGN AND PATIENTS

Ten in vitro specimens of synovial fluid from patients with both degenerative and inflammatory arthropathy were studied at body temperature with a navigator-corrected spin echo diffusion sequence (B values 0-512 s/mm2), on a Philips 1.5-T Gyroscan. Subsequently synovial fluid from knee joint effusions of 25 patients (10 patients with osteoarthritis, 10 patients with effusions following trauma and 5 patients with effusions secondary to inflammatory arthritis) was evaluated with the same navigator-corrected spin echo diffusion sequence.

RESULTS

Both in vitro and in vivo study demonstrated decreased diffusion in patients with effusions secondary to degenerative joint disease (less than 2.40 x 10(-5) cm2/s) relative to patients with effusions accompanying knee trauma (greater than 2.75 x 10(-5) cm2/s) and inflammatory arthritis (in vitro and in vivo greater than 3.00 x 10(-5) cm2/s).

CONCLUSION

Synovial fluid in degenerative arthritis shows less diffusion or free water movement than synovial fluid in inflammatory arthritis. Diffusion characteristics of synovial fluid may be used to predict the nature of the underlying form of arthritis in patients presenting with knee joint effusions.

Heritability of angiotensin-converting enzyme and angiotensinogen: A comparison of US blacks and Nigerians

Angiotensinogen (AGT) and angiotensin I-converting enzyme (ACE) are heritable traits, but whether the environmental context influences heritability has not been examined. Known genetic factors explain only a portion of variation in AGT and ACE, and levels of both proteins are influenced by the environment. The African diaspora provides an opportunity to compare these traits in genetically related populations in contrasting environments. As part of a study of the genetics of hypertension, we examined families that included 1449 Nigerians and 1147 African Americans. Body mass index (weight [kg]/height [m](2)) was 21 kg/m(2) in Nigeria and 29 kg/m(2) in the United States, which is consistent with a large environmental contrast. AGT was considerably higher among African Americans (1919 versus 1396, P<0.01), whereas ACE was higher in Nigerians (630 versus 517, P<0.01). A household effect was observed among the Nigerian families (spouse correlations 0.30 for AGT, 0.18 for ACE), and correlations among first-degree relatives were large (0.42 to 0. 51 and 0.36 to 0.38 for AGT and ACE, respectively). Among African Americans, the familial aggregations of AGT and ACE were very limited, and the familial correlation for AGT was not different from zero. Heritability was 77% for AGT and 67% for ACE in Nigeria and 18% for AGT and ACE in the United States. The familial patterns of body mass index and blood pressure were similar among both family sets. In conclusion, less familial aggregation was observed for AGT and ACE in the United States than in Nigeria, most likely reflecting a greater random individual environmental effect on these traits. Variation in heritability of traits could influence the power of epidemiological studies to identify genetic effects.

Airway inflammation, airway responsiveness and cough before and after inhaled budesonide in patients with eosinophilic bronchitis

Eosinophilic bronchitis is a common cause of chronic cough, characterized by sputum eosinophilia similar to that seen in asthma, but unlike asthma the patients have no objective evidence of variable airflow obstruction or airway hyperresponsiveness. The reason for the different functional associations is unclear. The authors have tested the hypothesis that in eosinophilic bronchitis the inflammation is mainly localized in the upper airway. In an open study the authors measured the lower (provocative concentration causing a 20% fall in forced expiratory volume in one second (PC20)) and upper (PC25 MIF50) airway responsiveness to histamine, lower and upper airway inflammation using induced sputum and nasal lavage, in II patients with eosinophilic bronchitis. The authors assessed changes in these measures and in cough reflex sensitivity to capsaicin and cough severity after 400 microg of inhaled budesonide for 4 weeks. A nasal eosinophilia was present in only three patients with one having upper airway hyperresponsiveness. Following treatment with inhaled corticosteroids the geometric mean sputum eosinophil count decreased from 12.8% to 2.9% (mean difference 4.4-fold, 95% confidence interval (CI) 2.14-10.02), the mean +/- sem cough visual analogue score on a 100 mm scale decreased from 27.2 +/- 6.6 mm to 12.6 +/- 5.7 mm (mean difference 14.6, 95% CI 9.1-20.1) and the cough sensitivity assessed as the capsaicin concentration required to cause two coughs (C2) and five coughs (C5) improved (C2 mean difference 0.75 doubling concentrations, 95% CI 0.36-1.1; C5 mean difference 1.3 doubling concentration, 95% CI 0.6-2.1). There was a significant positive correlation between the fold change in sputum eosinophil count and doubling dose change in C5 after inhaled budesonide (r=0.61). It is concluded that upper airway inflammation is not prominent in eosinophilic bronchitis and that inhaled budesonide improves the sputum eosinophilia, cough severity and sensitivity suggesting a causal link between the inflammation and cough.