A disease-associated gene desert directs macrophage inflammation through ETS2.

Increasing rates of autoimmune and inflammatory disease present a burgeoning threat to human health1. This is compounded by the limited efficacy of available treatments1 and high failure rates during drug development2, highlighting an urgent need to better understand disease mechanisms. Here we show how functional genomics could address this challenge. By investigating an intergenic haplotype on chr21q22-which has been independently linked to inflammatory bowel disease, ankylosing spondylitis, primary sclerosing cholangitis and Takayasu's arteritis3-6-we identify that the causal gene, ETS2, is a central regulator of human inflammatory macrophages and delineate the shared disease mechanism that amplifies ETS2 expression. Genes regulated by ETS2 were prominently expressed in diseased tissues and more enriched for inflammatory bowel disease GWAS hits than most previously described pathways. Overexpressing ETS2 in resting macrophages reproduced the inflammatory state observed in chr21q22-associated diseases, with upregulation of multiple drug targets, including TNF and IL-23. Using a database of cellular signatures7, we identified drugs that might modulate this pathway and validated the potent anti-inflammatory activity of one class of small molecules in vitro and ex vivo. Together, this illustrates the power of functional genomics, applied directly in primary human cells, to identify immune-mediated disease mechanisms and potential therapeutic opportunities.

Cefepime-Induced Generalized Fixed Drug Eruption With Morbilliform Rash.

Fixed drug eruption (FDE) is a cutaneous reaction that characteristically recurs in the same locations upon re-exposure to the offending drug(s). The typical presentation of FDEs is single or multiple violaceous plaques with hyperpigmentation due to inflammation. The causative agents for FDEs include antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, barbiturates, and anticonvulsants. We present an interesting case of a generalized fixed drug eruption secondary to cefepime that resolved with the cessation of the offending drug and the institution of antihistamines and topical steroids.

Epiescleritis y edema periorbitario secundario a síndrome VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) / Episcleritis and periorbital edema secondary to VEXAS syndrome

El síndrome vacuolas, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) es una nueva entidad autoinflamatoria descrita recientemente, producida por una mutación del gen UBA-1. Entre los síntomas más frecuentes están la fiebre, las citopenias, la policondritis, los infiltrados pulmonares y hasta en un 40% afectación ocular en forma de edema periorbitario, uveítis, epiescleritis, escleritis y vasculitis retiniana. Los pacientes responden a altas dosis de corticoterapia, sin embargo muchos terminan siendo refractarios a las mismas y a los inmunosupresores clásicos. Se describe el caso de un paciente varón de 77 años con afectación ocular en forma de epiescleritis y edema periorbitario que posteriormente fue diagnosticado de síndrome VEXAS. El paciente, tras fracasar al tratamiento con inmunosupresores, en la actualidad está en tratamiento con esteroides orales y tocilizumab. Los especialistas en oftalmología deben estar al corriente de la afectación oftalmológica de las enfermedades autoinflamatorias, y en especial de esta nueva entidad descrita, como es el síndrome VEXAS (AU)

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly described autoinflammatory entity caused by a UBA-1 gene mutation. Among the most frequent symptoms it produces fever, cytopenias, polychondritis, pulmonary infiltrates and up to 40% ocular involvement such as periorbital edema, uveitis, episcleritis, scleritis and retinal vasculitis. Patients respond to high doses of corticosteroids, however, many end up being refractory to them and to the classic immunosuppressants. We described the case of a 77-year-old male patient with ocular involvement in the form of episcleritis and periorbital edema who was later diagnosed with VEXAS syndrome. The patient, after failing treatment with immunosuppressants, is currently receiving treatment with oral steroids and tocilizumab. Ophthalmologist must be aware of the ophthalmological affectation of autoinflammatory diseases and especially of this new entity described as the VEXAS syndrome (AU)

Differences in the transcriptome response in the gills of sea lamprey acutely exposed to 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide or a TFM:niclosamide mixture.

Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America makes use of two pesticides: 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide, which are often co-applied. Sea lamprey appear to be vulnerable to these agents resulting from a lack of detoxification responses with evidence suggesting that lampricide mixtures produce a synergistic effect. However, there is a lack of information pertaining to the physiological responses of sea lamprey to niclosamide and TFM:niclosamide mixtures. Here, we characterized the transcriptomic responses of the sea lamprey to TFM, niclosamide, and a TFM:niclosamide (1.5 %) mixture in the gill. Along with a control, larval sea lamprey were exposed to each treatment for 6 h, after which gill tissues were extracted for measuring whole-transcriptome responses using RNA sequencing. Differential gene expression patterns were summarized, which included identifying the broad roles of genes and common expression patterns among the treatments. While niclosamide treatment resulted in no differentially expressed genes, TFM- and mixture-treated fish had several differentially expressed genes that were associated with the cell cycle, DNA damage, metabolism, immune function, and detoxification. However, there was no common differential expression among treatments. For the first time, we characterized the transcriptomic response of sea lamprey to niclosamide and a TFM:niclosamide mixture and identified that these agents impact mRNA transcript abundance of genes associated with the cell cycle and cellular death, and immune function, which are likely mediated through mitochondrial dysregulation. These results may help to inform the production of more targeted and effective lampricides in sea lamprey control efforts.

Episcleritis and periorbital edema secondary to VEXAS syndrome.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly described autoinflammatory entity caused by a UBA-1 gene mutation. Among the most frequent symptoms it produces fever, cytopenias, polychondritis, pulmonary infiltrates and up to 40% ocular involvement such as periorbital edema, uveitis, episcleritis, scleritis and retinal vasculitis. Patients respond to high doses of corticosteroids, however, many end up being refractory to them and to the classic immunosuppressants. We described the case of a 77-year-old male patient with ocular involvement in the form of episcleritis and periorbital edema who was later diagnosed with VEXAS Syndrome. The patient, after failing treatment with immunosuppressants, is currently receiving treatment with oral steroids and tocilizumab. Ophthalmologist must be aware of the ophthalmological affectation of autoinflammatory diseases and especially of this new entity described as the VEXAS Syndrome.

Transcriptomic impacts and potential routes of detoxification in a lampricide-tolerant teleost exposed to TFM and niclosamide.

Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America often relies on the application of 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide mixtures to kill larval sea lamprey. Selectivity of TFM against lampreys appears to be due to differential detoxification ability in these jawless fishes compared to bony fishes, particularly teleosts. However, the proximate mechanisms of tolerance to the TFM and niclosamide mixture and the mechanisms of niclosamide toxicity on its own are poorly understood, especially among non-target fishes. Here, we used RNA sequencing to identify specific mRNA transcripts and functional processes that responded to niclosamide or a TFM:niclosamide mixture in bluegill (Lepomis macrochirus). Bluegill were exposed to niclosamide or TFM:niclosamide mixture, along with a time-matched control group, and gill and liver tissues were sampled at 6, 12, and 24 h. We summarized the whole-transcriptome patterns through gene ontology (GO) term enrichment and through differential expression of detoxification genes. The niclosamide treatment resulted in an upregulation of several transcripts associated with detoxification (cyp, ugt, sult, gst), which may help explain the relatively high detoxification capacity in bluegill. Conversely, the TFM:niclosamide mixture resulted in an enrichment of processes related to arrested cell cycle and growth, and cell death alongside a diverse detoxification gene response. Detoxification of both lampricides likely involves the use of phase I and II biotransformation genes. Our findings strongly suggest that the unusually high tolerance of bluegill to lampricides is due to these animals having an inherently high capacity and flexible detoxification response to such compounds.

Variation in the Transcriptome Response and Detoxification Gene Diversity Drives Pesticide Tolerance in Fishes.

Pesticides are critical for invasive species management but often have negative effects on nontarget native biota. Tolerance to pesticides should have an evolutionary basis, but this is poorly understood. Invasive sea lamprey (Petromyzon marinus) populations in North America have been controlled with a pesticide lethal to them at lower concentrations than native fishes. We addressed how interspecific variation in gene expression and detoxification gene diversity confer differential pesticide sensitivity in two fish species. We exposed sea lamprey and bluegill (Lepomis macrochirus), a tolerant native species, to 3-trifluoromethyl-4-nitrophenol (TFM), a pesticide commonly used in sea lamprey control. We then used whole-transcriptome sequencing of gill and liver to characterize the cellular response in both species. Comparatively, bluegill exhibited a larger number of detoxification genes expressed and a larger number of responsive transcripts overall, which likely contributes to greater tolerance to TFM. Understanding the genetic and physiological basis for pesticide tolerance is crucial for managing invasive species.

Diversity of funnel plasmodesmata in angiosperms: the impact of geometry on plasmodesmal resistance.

In most plant tissues, threads of cytoplasm, or plasmodesmata, connect the protoplasts via pores in the cell walls. This enables symplasmic transport, for instance in phloem loading, transport and unloading. Importantly, the geometry of the wall pore limits the size of the particles that may be transported, and also (co-)defines plasmodesmal resistance to diffusion and convective flow. However, quantitative information on transport through plasmodesmata in non-cylindrical cell wall pores is scarce. We have found conical, funnel-shaped cell wall pores in the phloem-unloading zone in growing root tips of five eudicot and two monocot species, specifically between protophloem sieve elements and phloem pole pericycle cells. 3D reconstructions by electron tomography suggested that funnel plasmodesmata possess a desmotubule but lack tethers to fix it in a central position. Model calculations showed that both diffusive and hydraulic resistance decrease drastically in conical and trumpet-shaped cell wall pores compared with cylindrical channels, even at very small opening angles. Notably, the effect on hydraulic resistance was relatively larger. We conclude that funnel plasmodesmata generally are present in specific cell-cell interfaces in angiosperm roots, where they appear to facilitate symplasmic phloem unloading. Interestingly, cytosolic sleeves of most plasmodesmata reported in the literature do not resemble annuli of constant diameter but possess variously shaped widenings. Our evaluations suggest that widenings too small for unambiguous identification on electron micrographs may drastically reduce the hydraulic and diffusional resistance of these pores. Consequently, theoretical models assuming cylindrical symmetries will underestimate plasmodesmal conductivities.

Synthesis and Performance of Aromatic Polyamide Ionenes as Gas Separation Membranes.

Here, we report the synthesis and thermophysical properties of seven primarily aromatic, imidazolium-based polyamide ionenes. The effects of varied para-, meta-, and ortho-connectivity, and spacing of ionic and amide functional groups, on structural and thermophysical properties were analyzed. Suitable, robust derivatives were cast into thin films, neat, or with stoichiometric equivalents of the ionic liquid (IL) 1-benzy-3-methylimidazolium bistriflimide ([Bnmim][Tf2N]), and the gas transport properties of these membranes were measured. Pure gas permeabilities and permselectivities for N2, CH4, and CO2 are reported. Consistent para-connectivity in the backbone was shown to yield the highest CO2 permeability and suitability for casting as a very thin, flexible film. Derivatives containing terephthalamide segments exhibited the highest CO2/CH4 and CO2/N2 selectivities, yet CO2 permeability decreased with further deviation from consistent para-linkages.

Midterm follow-up of total hip arthroplasty in a patient with contralateral Van Nes rotationplasty for congenital proximal femoral focal deficiency.

Total hip arthroplasty is a durable and effective operation in those with normal gait patterns. However, to our knowledge, there is no current literature on longevity in patients who have had a contralateral Van Nes rotationplasty for proximal femoral focal deficiency. We found evidence that patients who underwent rotationplasty have increased demands on the contralateral extremity and higher percentage of their gait cycle on the unaffected extremity. Here, we present a unique case report of a 59-year-old male patient with a 6-year follow-up status after left total hip arthroplasty and a right-sided rotationplasty performed during adolescence. Upon chart and radiograph review, we found no early signs of wear of his hip arthroplasty and a fully functioning lower extremity. In our limited experience, we found that total hip arthroplasty was a safe and durable operation for our patient who underwent a contralateral Van Nes rotationplasty at the 6-year follow-up period.

Quasi-Resonance Fluorine-19 Signal Amplification by Reversible Exchange.

We report on an extension of the quasi-resonance (QUASR) pulse sequence used for signal amplification by reversible exchange (SABRE), showing that we may target distantly J-coupled 19F-spins. Polarization transfer from the parahydrogen-derived hydrides to the 19F nucleus is accomplished via weak five-bond J-couplings using a shaped QUASR radio frequency pulse at a 0.05 T magnetic field. The net result is the direct generation of hyperpolarized 19F z-magnetization, derived from the parahydrogen singlet order. An accumulation of 19F polarization on the free ligand is achieved with subsequent repetition of this pulse sequence. The hyperpolarized 19F signal exhibits clear dependence on the pulse length, irradiation frequency, and delay time in a manner similar to that reported for 15N QUASR-SABRE. Moreover, the hyperpolarized 19F signals of 3-19F-14N-pyridine and 3-19F-15N-pyridine isotopologues are similar, suggesting that (i) polarization transfer via QUASR-SABRE is irrespective of the nitrogen isotopologue and (ii) the presence or absence of the spin-1/2 15N nucleus has no impact on the efficiency of QUASR-SABRE polarization transfer. Although optimization of polarization transfer efficiency to 19F (P19F ≈ 0.1%) was not the goal of this study, we show that high-field SABRE can be efficient and broadly applicable for direct hyperpolarization of 19F spins.

Synthesis and Characterization of Ionene-Polyamide Materials as Candidates for New Gas Separation Membranes.

A new family of six ionenes containing aromatic amide linkages has been synthesized from ready available starting materials at scales up to ~50 g. These ionene-polyamides are all constitutional isomers and vary only in the regiochemistry of the amide linkages (para, meta) and xylyl linkages (ortho, meta, para) which are present in the polymer backbone. This paper details the synthesis of these ionenes and associated characterizations. Ionene-polyamides exhibit relatively low melting points (~150 oC) allowing them to be readily processed into films and other objects. These ionene-polyamide materials are being developed for further study as polymer membranes for the separations of gases such as CO2, N2, CH4 and H2.

Temporal characteristics of exercise-induced diaphragmatic fatigue.

There is evidence suggesting diaphragmatic fatigue (DF) occurs relatively early during high-intensity exercise; however, studies investigating the temporal characteristics of exercise-induced DF are limited by incongruent methodology. Eight healthy adult males (25 ± 5 yr) performed a maximal incremental exercise test on a cycle ergometer on day 1. A constant-load time-to-exhaustion (TTE) exercise test was conducted on day 2 at 60% delta between the calculated gas exchange threshold and peak work rate. Two additional constant-load exercise tests were performed at the same intensity on days 3 and 4 in a random order to either 50 or 75% TTE. DF was assessed on days 2, 3, and 4 by measuring transdiaphragmatic twitch pressure (Pdi,tw) in response to cervical magnetic stimulation. DF was present after 75 and 100% TTE (≥20% decrease in Pdi,tw). The magnitude of fatigue was 15.5 ± 5.7%, 23.6 ± 6.4%, and 35.0 ± 12.1% at 50, 75, and 100% TTE, respectively. Significant differences were found between 100 to 75 and 50% TTE (both P < 0.01), and 75 to 50% TTE ( P < 0.01). There was a significant relationship between the magnitude of fatigue and cumulative diaphragm force output ( r = 0.785; P < 0.001). Ventilation, the mechanical work of breathing (WOB), and pressure-time products were not different between trials ( P > 0.05). Our data indicate that exercise-induced DF presents a relatively late onset and is proportional to the cumulative WOB; thus the ability of the diaphragm to generate pressure progressively declines throughout exercise. NEW & NOTEWORTHY The notion that diaphragmatic fatigue (DF) occurs relatively early during exercise is equivocal. Our results indicate that DF occurs during high-intensity endurance exercise in healthy men and its magnitude is strongly related to the amount of pressure and work generated by respiratory muscles. Thus we conclude that the work of breathing is the major determinant of exercise-induced DF.

Reliability of the diaphragmatic compound muscle action potential evoked by cervical magnetic stimulation and recorded via chest wall surface EMG.

INTRODUCTION: Stimulation of the phrenic nerve via cervical magnetic stimulation (CMS) elicits a compound muscle action potential (CMAP) that allows for assessment of diaphragm activation. The reliability of CMS to evoke the CMAP recorded by chest wall surface EMG has yet to be comprehensively examined. METHODS: CMS was performed on healthy young males (n=10) and females (n=10). Surface EMG electrodes were placed on the right and left hemi-diaphragm between the 6-8th intercostal spaces. CMAPs were analysed for: latency, duration, peak-to-peak amplitude, and area. Reliability within and between experimental sessions was assessed using intraclass correlation coefficients (ICC). Bilateral (right-left) and sex-based (male-female) comparisons were also made (independent samples t-test). RESULTS: All CMAP characteristics demonstrated high reproducibility within (ICCs>0.96) and between (ICCs>0.89) experimental sessions. No statistically significant bilateral or sex-based differences were found (p>0.05). DISCUSSION: CMS is a reliable and non-invasive method to evaluate phrenic nerve conduction.

Nomenclature and classification of vasculitis - update on the ACR/EULAR diagnosis and classification of vasculitis study (DCVAS).

Classification of vasculitis remains unsatisfactory. This is largely because the pathogenetic mechanisms of this family of related disorders have not been fully understood. Existing classification criteria are useful but limited. This has become more apparent with the advent of more effective and more specific therapies. A rational basis for classification could significantly improve our approach to treatment. The development of diagnostic criteria in vasculitis is an even greater challenge but may ultimately provide more useful for the non-specialist clinician. International efforts are underway to provide more effective classification and diagnostic criteria.

Histone deacetylase inhibitors induce remission in transgenic models of therapy-resistant acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is associated with chromosomal translocations, invariably involving the retinoic acid receptor alpha (RAR alpha) gene fused to one of several distinct loci, including the PML or PLZF genes, involved in t(15;17) or t(11;17), respectively. Patients with t(15;17) APL respond well to retinoic acid (RA) and other treatments, whereas those with t(11;17) APL do not. The PML-RAR alpha and PLZF-RAR alpha fusion oncoproteins function as aberrant transcriptional repressors, in part by recruiting nuclear receptor-transcriptional corepressors and histone deacetylases (HDACs). Transgenic mice harboring the RAR alpha fusion genes develop forms of leukemia that faithfully recapitulate both the clinical features and the response to RA observed in humans with the corresponding translocations. Here, we investigated the effects of HDAC inhibitors (HDACIs) in vitro and in these animal models. In cells from PLZF-RAR alpha/RAR alpha-PLZF transgenic mice and cells harboring t(15;17), HDACIs induced apoptosis and dramatic growth inhibition, effects that could be potentiated by RA. HDACIs also increased RA-induced differentiation. HDACIs, but not RA, induced accumulation of acetylated histones. Using microarray analysis, we identified genes induced by RA, HDACIs, or both together. In combination with RA, all HDACIs tested overcame the transcriptional repression exerted by the RAR alpha fusion oncoproteins. In vivo, HDACIs induced accumulation of acetylated histones in target organs. Strikingly, this combination of agents induced leukemia remission and prolonged survival, without apparent toxic side effects.

Trial of a two-channel hearing aid (low-frequency compression-high-frequency linear amplification) with school age children.

OBJECTIVE: The study was designed to investigate the efficacy of a 2-channel hearing aid with low-frequency compression and high-frequency linear amplification on a group of school-age hearing aid wearers. DESIGN: The study was a single-center, 2-way crossover design in which 25 children (age 6 to 15 yr) were fitted with 2-channel hearing aids for 12 wk and with their own (single-channel) hearing aids for 12 wk, refitted according to published protocols. Speech perception in quiet and in noise was measured at the end of each 12 wk period; in addition, questionnaires were given to teachers, parents, and children. RESULTS: Two-channel hearing aids showed significantly higher mean scores for speech perception in noise and significantly higher composite questionnaire scores (reflecting aspects of satisfaction and benefit). Final choice of hearing aids at the end of the study by parents and children also favored the 2-channel device. CONCLUSIONS: The 2-channel hearing aids appear to be an acceptable management option for audiometrically suitable children. The results provide support for the 2-channel design rationale and suggest the need for further trials.

Comparison of depression in the community-dwelling and assisted-living elderly.

Depressive affect in assisted living (n = 351) and community dwelling (n = 102) elderly was compared by means of the state and trait forms of Set 1 of the Depression Adjective Check Lists (DACL). Four separate analyses of covariance (age as covariate) showed the main effects of living arrangement and form to be significant on each of the four lists. Assisted living and the state form were significantly higher. Sex was not significant on any of the lists, and none of the two-way and three-way interactions reached significance. Implications of the findings for program planning for the elderly in assisted living arrangements are discussed.

Predominance of endothelinA (ETA) receptors in ovine airway smooth muscle and their mediation of ET-1-induced contraction.

1. Autoradiographic studies were conducted to investigate the receptor subtypes for endothelin-1 (ET-1) that were present in the ovine respiratory tract. In addition, the receptor subtypes mediating contraction of airway smooth muscle and the possible involvement of extracellular Ca2+ and inositol phosphate generation in intracellular signal transduction were assessed. 2. Specific [125I]-ET-1 binding in ovine trachea increased in a time- and concentration-dependent manner. Autoradiographic studies demonstrated that significant binding was associated with airway smooth muscle, although higher densities of specific binding were associated with submucosal glands and with cells immediately below the epithelial basement membrane (lamina propria). The ETA receptor-selective antagonist, BQ 123 (1 microM), virtually abolished specific binding to airway smooth muscle. Quantitative analyses of autoradiographic data describing the time-dependence of specific [125I]-ET-1 binding in ovine airway smooth muscle in the presence and absence of BQ 123 or sarafotoxin S6c, revealed a homogeneous population of ETA receptors. BQ 123 (1 microM) also abolished specific binding to structures associated with submucosal glands, whereas the ETB receptor selective agonist, sarafotoxin S6c (100 nM) had little effect on this binding, indicating the predominance of ETA receptors at these sites. In contrast, ETB receptors predominated in the lamina propria, since sarafotoxin S6c abolished specific binding in this tissue. 3. High levels of specific [125I]-ET-1 binding were also detected in the alveoli and in the walls of blood vessels and small airways in ovine peripheral lung. Specific binding associated with alveoli was reduced to similar extents by BQ 123 (1 MicroM; 54%) and sarafotoxin S6c (100 nM; 40%), suggesting the coexistence of both ETA and ETB receptors in approximately equal proportions in this tissue. In contrast,specific binding to blood vessels and to peripheral bronchial smooth muscle was abolished in the presence of BQ 123 (1 MicroM), but was unaffected by sarafotoxin S6c, indicating the presence of only ETA receptors at these sites.4. ET-1 caused concentration-dependent contractions of ovine tracheal smooth muscle which were inhibited in the presence of BQ 123 (1 MicroM). ET-1 also caused concentration-dependent contraction of ovine lung parenchyma strips. In contrast, the ETB receptor-selective agonists, sarafotoxin S6c and BQ 3020, were virtually inactive as spasmogens in both tracheal smooth muscle and lung strip preparations.Thus contraction was mediated by ETA receptors in ovine tracheal smooth muscle and this is consistent with binding and autoradiographic data demonstrating a homogeneous population of these binding sites in this tissue. Contraction of parenchymal lung strip preparations to ET-1 was mediated via non-ETB receptors, presumably ETA receptors, with contributions to this response perhaps coming from airway and vascular smooth muscle and from alveolar wall contractile cells.5. ET-1-induced contraction of tracheal smooth muscle was not significantly altered in the presence of indomethacin (5 MicroM), indicating that cyclo-oxygenase metabolites of arachidonic acid were not involved in this response. Contraction induced by ET-1 was virtually abolished in Ca2+-free medium containing 0.1 mM EGTA, indicating that this response was dependent upon the influx of extracellular Ca2 .Contraction was inhibited by about 50% in the presence of nicardipine (1 MicroM), indicating that a significant component of this response was mediated via the activation of L-type Ca2+ channels.6. ET-1 caused poorly defined increases in the accumulation of intracellular inositol phosphates in ovine tracheal smooth muscle. The maximal response to ET-1 was less than 20% of that to the cholinoceptor agonist, carbachol. Furthermore, sarafotoxin S6c was inactive. These data, when taken together with the results of autoradiographic and contraction studies, indicate that ovine airway smooth muscle contraction in response to ET-1 is mediated via ETA receptors which are linked to the influx of extracellular Ca2+, partly through voltage-dependent channels. ETB receptors also exist in the lamina propria of ovine trachea and in peripheral alveoli, perhaps residing in vascular endothelial cells.