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Biomedical subjects

T J Williams

Publications and source records attributed to T J Williams.

At least 127 records · Page 7Linked to original sources

Scar collagen deposition in the airways of allografts of lung transplant recipients.

Collagen subtype deposition has not been studied in the airways of transplanted lungs. As part of rejection, a series of immunologic insults results in a remodeling of the allograft. In chronic rejection, changes in the airway leading to obliterative bronchiolitis syndrome (OBS) are particularly important. To better understand the mechanism of OBS occurring in chronic lung rejection, we investigated deposition of three fibrillar collagens (type I, III, V) in airway biopsies of lung allografts taken from 10 clinically well lung transplant recipients (wLTR) and eight lung transplant recipients (LTR) with OBS (OBLTR) using an immunoperoxidase method. Collagen III deposition and the ratio of collagen type III to type I were found to be significantly increased in OBLTR compared with wLTR (p < 0.05), and the latter correlated inversely with both FEF(25-75) (r = -0.69; p < 0.05) and FEV1 (r = 0.62; p = 0.05) in OBLTR. This suggests that an increased proportion of collagen III in the airway walls of transplanted lungs might be an early signal of the progression to terminal chronic lung allograft dysfunction. The changes in the ratio of type III to type I collagen in the airways of lung allografts may provide important insights into the process of airway remodeling in chronic lung rejection.

Adult↗

Quantitative detection of human cytomegalovirus DNA in lung transplant recipients.

Human cytomegalovirus (HCMV) disease remains a major cause of morbidity and mortality after lung transplantation. Currently, routine diagnostic tests for HCMV are inefficient and insensitive or nonspecific for HCMV disease. We describe an efficient, highly sensitive, quantitative polymerase chain reaction (PCR) assay for HCMV using competitive PCR and fluorescently labeled primers, and we have used this to measure HCMV DNA load in donor and recipient tissues of six lung transplant recipients at the time of transplantation, and 2 wk after transplantation when clinically stable. Total DNA yield was adequate for analysis in transbronchial biopsy, bronchoalveolar lavage, and peripheral blood leukocytes, but the endobronchial biopsy specimens did not consistently produce sufficient DNA for analysis. There was a large intersubject and intrasubject variability between tissues in HCMV DNA load, with a tendency for greater levels in lung tissue compared with BAL or peripheral blood cells. All six HCMV IgG seronegative donors or recipients were found to have HCMV DNA present. One of the three seronegative matched transplant recipients developed histopathologically proven HCMV disease, and HCMV DNA levels were shown to increase at that time point and subsequently decrease with ganciclovir treatment. This assay will allow prospective studies to confirm the predictive value of HCMV DNA load in donor and recipient tissues for HCMV disease.

Antibodies, Viral↗

Eotaxin protein and gene expression in guinea-pig lungs: constitutive expression and upregulation after allergen challenge.

Eotaxin is an eosinophil-specific chemoattractant originally identified in bronchoalveolar lavage fluid after allergen challenge of sensitized guinea-pigs. We have determined and quantified for the first time the cellular sources of guinea-pig lung eotaxin and localized gene expression in structural cells of large and small airways and in alveolar macrophages. We used anti-guinea-pig eotaxin monoclonal and polyclonal antibodies and a complementary ribonucleic acid (cRNA) probe to detect eotaxin protein and cytoplasmic messenger ribonucleic acid (mRNA) transcripts by the techniques of immunohistochemistry and in situ hybridization in: 1) naive; 2) ovalbumin-sensitized/ saline-exposed; and 3) ovalbumin-sensitized/ovalbumin-challenged animals (n = 5 for each group). Compared with the naive animals, there was a fivefold increase of eotaxin protein and a 25 fold upregulation of eotaxin gene expression in the airway epithelium 3 h after ovalbumin challenge of sensitized animals (p < 0.001). The average percentages of alveolar macrophages staining for eotaxin protein and mRNA in the naive animals were approximately 30 and 10% respectively: both increased significantly in the sensitized/ovalbumin-challenged animals to 78 and 57%, respectively (p < 0.0001). Compared with the naive animals, the procedure of sensitization and saline exposure significantly increased eotaxin gene expression in both bronchial epithelium and alveolar macrophages (p < 0.01): the upregulation at these two sites showed a strong positive association (rcorr = 0.95; p < 0.0001). The results indicate that there are multiple cellular sources of guinea-pig lung-derived eotaxin, including bronchial and bronchiolar epithelial cells, airway smooth muscle, bronchial vascular endothelium, and chondrocytes and alveolar macrophages, and that there are relatively rapid and marked increases of eotaxin protein and gene expression in airway epithelium and alveolar macrophages following allergen challenge.

Allergens↗

Airway versus transbronchial biopsy and BAL in lung transplant recipients: different but complementary.

Lung transplantation is now an established therapeutic intervention for end-stage cardiopulmonary disease in humans. Chronic rejection, in the form of bronchiolitis obliterans syndrome (BOS), remains the commonest cause of morbidity and mortality in those surviving more than 3 months. The pathology of BOS involves airway changes. We have evaluated the potential for endobronchial biopsies (EBB) to complement existing sampling methods used in allograft monitoring and have compared the results of EBB findings with those of bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) in 18 clinically stable patients. We found that all the EBB had inflammatory cells present but that only five TBB specimens had evidence of inflammation, with airway material being present in 78% of the TBB. Paired BAL and EBB yielded different results, with no correlations between total macrophages, lymphocytes, CD4+ cells or CD8+ cells. We conclude that endobronchial biopsies are potentially useful as an additional sample for the monitoring of inflammation in lung allografts, since they yield different, and potentially complimentary, information to bronchoalveolar lavage and transbronchial biopsy.

Adult↗

The role of the eosinophil-selective chemokine, eotaxin, in allergic and non-allergic airways inflammation.

Blood eosinophilia and tissue infiltration by eosinophils are frequently observed in allergic inflammation and parasitic infections. This selective accumulation of eosinophils suggested the existence of endogenous eosinophil-selective chemoattractants. We have discovered a novel eosinophil-selective chemoattractant which we called eotaxin in an animal model of allergic airways disease. Eotaxin is generated in both allergic and non-allergic bronchopulmonary inflammation. The early increase in eotaxin paralleled eosinophil infiltration in the lung tissue in both models. An antibody to IL-5 suppressed lung eosinophilia, correlating with an inhibition of eosinophil release from bone marrow, without affecting eotaxin generation. This suggests that endogenous IL-5 is important for eosinophil migration but does not appear to be a stimulus for eotaxin production. Constitutive levels of eotaxin observed in guinea-pig lung may be responsible for the basal lung eosinophilia observed in this species. Allergen-induced eotaxin was present mainly in the epithelium and alveolar macrophages, as detected by immunostaining. In contrast there was no upregulation of eotaxin by the epithelial cells following the injection of sephadex beads and the alveolar macrophage and mononuclear cells surrounding the granuloma were the predominant positive staining cells. Eotaxin and related chemokines acting through the CCR3 receptor may play a major role in eosinophil recruitment in allergic inflammation and parasitic diseases and thus offer and attractive target for therapeutic intervention.

Animals↗

Description of an in vivo model for the assessment of eosinophil chemoattractants in the mouse.

Chemokines (chemoattractant cytokines) induce potent and selective chemotaxis of leukocyte subsets in vitro. Here, we review briefly the chemokines shown to induce eosinophil chemotaxis in vitro and describe a novel model for the study of the ability of chemokines to stimulate eosinophil migration in vivo. Eosinophils were purified from the blood of mice over-expressing the IL-5 gene and labelled with 111In. Only the C-C chemokines, eotaxin and MIP-1 alpha, but not RANTES, MCP-1, MCP-3, MCP-4, MIP-1 beta, KC and MIP-2, effectively induced the recruitment of 111 In-eosinophils in mouse skin. We suggest that this mouse model will be useful in assessing the role of endogenously-generated chemokines in mediating eosinophil migration to sites of allergic inflammation in vivo.

Animals↗

Human RANTES acts as a receptor antagonist for guinea pig eotaxin in vitro and in vivo.

The guinea pig C-C chemokine, eotaxin, is a potent and selective eosinophil chemoattractant in guinea pig airways and skin in vivo, and stimulates both guinea pig and human eosinophils in vitro. The human C-C chemokine RANTES (30% homology with guinea pig eotaxin) stimulates human eosinophils in vitro, but does not stimulate guinea pig eosinophils, even though these cells bind 125I-RANTES. Similar concentrations of eotaxin and unlabeled RANTES competitively inhibit the binding of 125I-RANTES to guinea pig eosinophils, suggesting that eotaxin and RANTES share a common binding site on these cells. In the present study, we investigated the possibility that human RANTES, binding to a putative eotaxin receptor on guinea pig eosinophils, might block functional responses to eotaxin. When fura-2-loaded cells were first exposed to RANTES, which failed to elevate the intracellular calcium concentration, the response to a subsequent challenge with eotaxin was inhibited in a dose-dependent manner. Inhibition was also demonstrated when the two chemokines were added simultaneously. Another human C-C chemokine, MCP-3 (52% homology with guinea pig eotaxin), had similar inhibitory effects on the eotaxin-induced activation of guinea pig eosinophils in vitro. RANTES inhibited (111)In-eosinophil accumulation in response to intradermal eotaxin in vivo. In contrast, RANTES had no significant effect on responses to leukotriene B4 in vitro or in vivo. Thus, these experiments in the guinea pig demonstrate that human RANTES is the first prototypic antagonist of an eotaxin receptor.

Amino Acid Sequence↗

An anti-platelet-endothelial cell adhesion molecule-1 antibody inhibits leukocyte extravasation from mesenteric microvessels in vivo by blocking the passage through the basement membrane.

Platelet-endothelial cell adhesion molecule-1 (PECAM-1, CD31) plays an active role in the process of leukocyte migration through cultured endothelial cells in vitro and anti-PECAM-1 antibodies (Abs) inhibit accumulation of leukocytes into sites of inflammation in vivo. Despite the latter, it is still not clear at which stage of leukocyte emigration in vivo PECAM-1 is involved. To address this point directly, we studied the effect of an anti-PECAM-1 Ab, recognizing rat PECAM-1, on leukocyte responses within rat mesenteric microvessels using intravital microscopy. In mesenteric preparations activated by interleukin (IL)-1 beta, the anti-PECAM-1 Ab had no significant effect on the rolling or adhesion of leukocytes, but inhibited their migration into the surrounding extravascular tissue in a dose-dependent manner. Although in some vessel segments these leukocytes had come to a halt within the vascular lumen, often the leukocytes appeared to be trapped within the vessel wall. Analysis of these sections by electron microscopy revealed that the leukocytes had passed through endothelial cell junctions but not the basement membrane. In contrast to the effect of the Ab in mesenteric preparations treated with IL-1 beta, leukocyte extravasation induced by topical or intraperitoneal administration of the chemotactic peptide formyl-methionyl-leucyl-phenylalanine was not inhibited by the anti-PECAM-1 Ab. These results directly demonstrate a role for PECAM-1 in leukocyte extravasation in vivo and indicate that this involvement is selective for leukocyte extravasation elicited by certain inflammatory mediators. Further, our findings provide the first in vivo indication that PECAM-1 may have an important role in triggering the passage of leukocytes through the perivascular basement membrane.

Animals↗

An assessment of the ability of a silver-releasing device to prevent bacterial contamination of urethral catheter drainage systems.

OBJECTIVE: To investigate the ability of a silver-releasing device to protect the catheterized bladder from infection by blocking the ascending migration of bacteria from contaminated urine-drainage bags. MATERIALS AND METHODS: A simple physical model of the catheterized bladder and drainage system was used with the device located in the drainage-tube just below the sampling port. Urine was supplied to the model at 1.0 mL/min and the drainage bag was contaminated with Pseudomonas aeruginosa, Escherichia coli and Proteus mirabilis. Over 10 days, urine from the bag, catheter sampling-port and bladder were examined for contamination. RESULTS: Bacteriological analysis showed that the mean time for test organisms to reach the sampling ports of four different control bag systems ranged from 5.7 to 7.7 days. Urine from the sampling ports of the test systems incorporating the silver device remained sterile for 10 days. The device also prevented the growth of the large populations of bacteria (10(8) colony-forming units per mL) that occurred in the control bags. While scanning electron microscopy showed the formation of bacterial biofilm throughout the control drainage systems, no bacterial colonization was visible on the surfaces of the test systems. Chemical analysis established that the devices consistently generated concentrations of silver in urine ranging from 1.0 to 2.0 micrograms/mL. CONCLUSION: The incorporation of the silver-releasing device into the drainage systems produced an antibacterial barrier which protected the catheterized bladder from intraluminal contamination for at least 10 days. These in vitro tests suggest a useful role for the device in controlling infection in patients undergoing short-term indwelling bladder catheterization.

Bacterial Infections↗

Scalloped wings is the Lucilia cuprina Notch homologue and a candidate for the modifier of fitness and asymmetry of diazinon resistance.

The Scalloped wings (Scl) gene of the Australian sheep blowfly, Lucilia cuprina, is shown to be the homologue of the Drosophila melanogaster Notch gene by comparison at the DNA sequence and genetic levels. A L. cuprina genomic fragment, which shows strong identity with the Notch (N) gene at the molecular level, hybridizes to the location of the Scl gene on polytene chromosomes. The two genes are functionally homologous; the dominant and recessive Notch-like phenotypes produced by mutations in the Scl gene allow these alleles to be classed as N-like or Abruptex-like. The Scl gene is under investigation as a candidate for the fitness and asymmetry Modifier (M) of diazinon resistance. We show that M affects the penetrance of wing and bristle phenotypes associated with two Scl alleles in a manner consistent with the M being an allele of Scl. In addition, we report a phenotypic interaction between the diazinon-resistance mutation, Rop-1, and the same alleles of Scl. We propose that the product of Rop-1, an esterase, may be involved in cell adhesion in developmental processes involving the Scl gene product.

Alleles↗

Enhancement of Schistosoma mansoni infectivity by intradermal injections of larval extracts: a putative role for larval proteases.

Extracts of Schistosoma mansoni cercariae caused increased vascular permeability and edema if administered to CBA/Ca mice by intradermal injection. Percutaneous infection with cercariae over the skin site at which cercarial homogenate (CH) had been injected intradermally resulted in a significant increase in the infectivity of S. mansoni compared with that shown by worm recovery from control animals (P < .05). This effect was abrogated by inhibition of protease activity prior to injection. Injection of inflammatory mediators (bradykinin or zymosan-activated plasma) with or without prostaglandin E2 produced a similar amount of edema as did CH. Injection of these mediators did not, however, enhance infectivity of cercariae. Pancreatic elastase was found to induce edema and enhancement of infectivity comparable to those induced by CH. The protease(s) introduced into the site of infection may have facilitated larval migration directly by hydrolyzing host tissue or indirectly by inducing an inflammatory response (or both).

Animals↗

Effect of soluble P55 tumour-necrosis factor binding fusion protein on the local Shwartzman and Arthus reactions.

1. In this study, the effects of a protein synthesis inhibitor, cycloheximide, and a soluble tumour necrosis factor (TNF) binding/IgG fusion protein, p55-sf2, on the priming and challenge stages of the local Shwartzman reaction (LSR) were assessed and compared with their effects on the acute inflammatory response induced by recombinant human tumour necrosis factor-alpha (rhTNF), lipopolysaccharide (LPS) and a reversed passive Arthus (RPA) reaction in rabbit skin. 2. The LSR was induced in skin by giving an intradermal (i.d.) priming injection of LPS followed by two i.v. challenge injections 20 h and 22 h later. Accumulation of 51-Cr-labelled red blood cells and [125I]-albumin were measured at 24 h as markers of haemorrhage and oedema formation, respectively. 3. The RPA reaction was induced in the rabbit by giving i.d. injections of Arthus anti-serum (anti-bovine-gamma-globulin, BGG) followed 5 min later by an i.v. injection of the antigen (BGG). Oedema formation and the accumulation of 111In-labelled neutrophils produced in the RPA reaction and in response to i.d. injection of rhTNF and LPS were measured over the 4 h period after inducing the responses. 4. A single local injection of cycloheximide (10 micrograms/site) did not inhibit neutrophil accumulation or oedema formation produced by 100% Arthus anti-sera. Although LPS injected i.d. induced a marked dose-dependent neutrophil accumulation, there was little associated plasma leakage. Cycloheximide (10 micrograms/site) did not significantly inhibit the neutrophil accumulation induced by LPS (0.1 microgram/site). In the LSR, priming i.d. injections of LPS caused a dose-dependent increase in haemorrhage and plasma leakage at skin sites after challenge with LPS (two injections of 100 micrograms, i.v.). Co-injection of a single dose of cycloheximide (10 micrograms/site) with LPS (30 micrograms/site) caused a marked reduction in the amount of haemorrhage. Local cycloheximide (10 micrograms/site) administered immediately before LSR challenge did not affect the responses produced in the LSR. 5. Neutrophil accumulation induced by TNF (0.17 micrograms/site) was abolished by co-administration of p55-sf2 (3 micrograms/site) whereas neutrophil accumulation induced by i.d. LPS and produced in the RPA reaction was not affected. In the LSR, haemorrhage and oedema formation were inhibited by p55-sf2 (3 micrograms/site) when it was administered i.d. with the LPS priming injection, but not when given i.d. immediately before LSR challenge. 6. These data suggest that the acute neutrophil accumulation produced in the RPA reaction and in response to i.d. LPS may not be dependent on local protein synthesis or TNF production. On the other hand, haemorrhage appears to be dependent on local protein synthesis during the priming phase but not during the challenge stage of the LSR. Importantly, haemorrhage and plasma leakage appear to be dependent on local TNF generation during the priming phase but not during the challenge stage of the LSR. Thus TNF appears to play a key role in the LSR in rabbit skin.

Animals↗

Effects of dexamethasone and cyclosporin A on the accumulation of eosinophils in acute cutaneous inflammation in the guinea-pig.

1. Eosinophils are thought to play an important role in the pathophysiology of allergic diseases and pharmacological suppression of their recruitment is considered to be of therapeutic benefit. In the present study we have assessed and compared the effects of treatment with dexamethasone and cyclosporin A on the accumulation of 111In-labelled eosinophils and local oedema formation in sites of acute inflammation in guinea-pig skin. 2. When injected locally 150 min prior to i.d. administration of antigen in a passive cutaneous anaphylactic (PCA) reaction, dexamethasone (10(-9) to 3 x 10(-7) mol per site) dose-dependently inhibited oedema formation by up to 50%. Similarly, oedema formation induced by PAF and lipopolysaccharide (LPS), but not by zymosan-activated plasma (ZAP), was significantly inhibited by dexamethasone. In contrast, 111In-eosinophil accumulation measured in response to i.d. injection of PAF, LPS and ZAP or in the PCA reaction was not altered. 3. Systemic treatment with dexamethasone (4 mg kg-1, i.v., 150 min pretreatment period) inhibited both oedema formation and 111In-eosinophil accumulation induced by PAF, ZAP, LPS and in the PCA reaction. 4. The effects of i.d. injection of cyclohexamide (2 x 10(-7) mol per site) on 111In-eosinophil accumulation and oedema formation induced by PAF, ZAP or in a PCA reaction were evaluated in order to assess the dependency of these responses on protein synthesis. Cycloheximide had no effect on the responses measured. In contrast, 111In-eosinophil accumulation, but oedema formation, induced by LPS was inhibited by 30%. 5. Acute (10 mg kg-1, i.v., 15 min pretreatment) or prolonged (10 mg kg-1, s.c. daily for 3 days) systemic treatment with cyclosporin A had no effect on 111In-eosinophil accumulation or oedema formation induced by PAF, ZAP, LPS or in the PCA reaction. 6. In conclusion, we demonstrate preferential inhibitory effects of dexamethasone on 111In-eosinophil accumulation according to its site of administration. In addition we show that dexamethasone inhibits protein synthesis-independent acute inflammation in guinea-pig skin. Finally, our results do not support the concept that eosinophils are an important cellular site of action for the inhibitory effects of cyclosporin A in a guinea-pig model of allergic inflammation.

Animals↗

Minimisation of aminoglycoside toxicity in patients with cystic fibrosis.

BACKGROUND: There is evidence that administration of higher doses of aminoglycosides given less frequently improves the bactericidal effect and reduces the potential to cause side effects. To investigate this, a prospectively randomised open label therapeutic trial was undertaken in stratified groups of patients with cystic fibrosis to examine the efficacy and toxic potential of an aminoglycoside dosing regimen designed to generate high peak drug concentrations at 12 hourly intervals compared with conventional dosing at eight hourly intervals. METHODS: Patients in group A received tobramycin eight hourly using a dose aimed at generating a peak concentration of 10 mg/l with trough concentrations below 2 mg/l, and those in group B received the total daily dose required to achieve eight hourly target concentrations administered as two equal 12 hourly doses. Clinical outcomes measured and assessed included vestibular symptoms, hearing and renal function, length of hospital stay, readmission rate, and mortality. RESULTS: Twenty nine patients were recruited during a six month period, 20 to group A and nine to group B. The average peak tobramycin level was higher in group B (12.5 (2.2) mg/l) than in group A (7.9 (1.9) mg/l), whilst the average trough level was higher in group A (0.8 (0.3) mg/l) than in group B (0.5 (0.2) mg/l). There was a difference in the number of ototoxic events between patients in group A (seven of 18, 38.9%) and group B (none of eight), but no difference was found in other outcome measures assessed. CONCLUSIONS: These results suggest that 12 hourly high peak aminoglycoside dosing may be less toxic than equivalent eight hourly dosing, without any apparent difference in efficacy.

Adult↗

A role for the beta2 integrin CD11b in mediating experimental lung injury in mice.

We have investigated the requirement of neutrophil emigration and the role for CD11b/CD18-mediated events in the experimental induction of acute lung injury. BALB/c mice received lipopolysaccharide (LPS) (3 mg/kg) intravenously (i.v.) 2 h prior to i.v. zymosan (10 mg/kg) and extravascular albumin accumulation was assessed after 30 min. Compared with saline-treated controls, zymosan alone caused a 6-fold increase in the accumulation of 125I-human serum albumin in whole lung tissue (P<0.05). Combined treatment with LPS and zymosan further increased extravascular albumin accumulation (P<0.05 compared with zymosan alone). The monoclonal antibody 5C6, directed against murine CD11b, was injected, 1 mg i.v. 15 min prior to LPS or 15 min before the zymosan, and compared with immunoglobulin G-injected controls. Albumin accumulation was significantly reduced by 5C6 when given prior to the LPS (P<0.01), but not when given before zymosan in the combined LPS and zymosan treatment. Interestingly, albumin accumulation induced by zymosan alone was not reduced by 5C6. The lungs of the mice treated with LPS and zymosan showed a marked, diffuse accumulation of inflammatory cells which, by light microscopy, appeared to be interstitial. Foci of neutrophil aggregates were seen in noncapillary microvessels, and pretreatment with 5C6 appeared to reduce their frequency. In the animals treated with zymosan alone, LPS alone, or LPS and zymosan in combination, electron microscopy established that approximately 25% of all nucleated cells were neutrophils: 99% of the neutrophils were restricted to the intravascular compartment. Pretreatment with 5C6 prior to LPS and zymosan treatment reduced the increase in percentage of neutrophils by half. These results indicate a disassociation between induction of permeability and neutrophil emigration in our murine model and suggest that the release of neutrophil-derived factors such as platelet-activating factor, proteases, or oxidants may be involved.

Animals↗

Cytolytic therapy for the bronchiolitis obliterans syndrome complicating lung transplantation.

UNLABELLED: The bronchiolitis obliterans syndrome (BOS) is the major cause of late morbidity and mortality after lung transplant (LTx). Previous studies suggest cytolytic therapy may be effective for the BOS but this therapy has not been proved effective or safe. METHOD: A retrospective study of a predetermined treatment regimen to determine if the rate of fall in FEV1 can be reduced by corticosteroids and cytolytic therapy. Since August 1992, 10 to 65 long-term survivors of LTx (5 men, 5 women; mean age 36 +/- 10 years) developed BOS. All had previously had lymphocyte immune globulin, antithymocyte globulin (equine) (ATGAM sterile solution; Upjohn Pty Ltd; Sydney, Australia) induction therapy and corticosteroid avoidance for the first 7 to 10 days post-LTx. Therapy for the BOS was initiated with pulse methylprednisolone and ATGAM (aiming for an absolute CD3 count of < or - 100 cells per microliter for 5 days). ATGAM therapy was initiated at a mean 657 +/- 323 days post-LTx. Subsequent follow-up has been for 310 +/- 110 days (range, 163 to 530 days). RESULTS: Nine of ten patients had a response with tolerable side effects. Preintervention, there was a linear fall in FEV1 of 0.22 +/- 0.15% predicted FEV1 per day (mean +/- SD) (range, 0.06 to 0.56%) compared with a postintervention linear fall of 0.036 +/- 0.019% predicted per day (range, 0 to 0.13%) (paired t test; p<0.005). This effect is sustained over the follow-up period. CONCLUSION: The fall off in FEV1 that characterizes the BOS may be altered usefully by augmented immunotherapy. This effect can be rapid and sustained although it is neither completely arrested nor ever reversed. These data are preliminary but encourage a randomized control trial in the BOS.

Adult↗

RS-17053 (N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro-alpha, alpha-dimethyl-1H-indole-3-ethanamine hydrochloride), a selective alpha 1A-adrenoceptor antagonist, displays low affinity for functional alpha 1-adrenoceptors in human prostate: implications for adrenoceptor classification.

Norepinephrine (NE) contracts smooth muscle cells within the human lower urinary tract (LUT) (bladder neck, prostate, and urethra). Receptor distribution and pharmacological evidence have implicated activation of alpha 1A-adrenoceptors. We disclose the pharmacological properties of the novel, selective alpha 1A-adrenoceptor antagonist N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro- alpha,alpha-dimethyl-1H-indole-3-ethanamine hydrochloride (RS-17053) and examine critically the pharmacological identity of the alpha 1-adrenoceptor mediating contractions to NE in human LUT tissues. In several tissues from rat and cloned adrenoceptors, RS-17053 displayed high affinity for the alpha 1A-adrenoceptor (pKi and pA2 estimates of 9.1-9.9) and a 30-100-fold selectivity over the alpha 1B- and the alpha 1D-adrenoceptor subtypes (pK1 and pA2 estimates of 7.7-7.8). However, in isolated smooth muscle preparations from human LUT tissues, RS-17053 antagonized responses to NE only at high concentrations. Estimates of affinity (pA2) at alpha 1-adrenoceptors mediating NE-induced contractions were 7.5 in prostatic periurethral longitudinal smooth muscle (compared with 8.6 for prazosin), 6.9 in anterior fibromuscular stroma (prazosin, 8.9), and 7.1 in bladder neck (prazosin, 8.5). These findings indicate that contractile responses to NE in human LUT tissues are mediated by a receptor displaying pharmacological properties that are clearly different from those of the defined alpha 1A-adrenoceptor and raise the possibility that multiple forms of the alpha 1A-adrenoceptor may exist in human LUT that are discriminated by RS-17053. In this regard, the affinity estimates obtained with RS-17053 and other alpha 1-adrenoceptor antagonists in human LUT tissues are identical to those described for the putative alpha 1L-adrenoceptor.

Adrenergic alpha-Antagonists↗