Matrix and modifier effects in the supercritical fluid extraction of cocaine and benzoylecgonine from human hair

The supercritical fluid extraction (SFE) behavior of cocaine and its major metabolite benzoylecgonine (BZE) was investigated and found to be highly dependent upon the chemical nature of the matrix and the manner in which the target drug analytes are incorporated into or on the matrix. The recovery of cocaine from Teflon wool, filter paper, drug-fortified hair, and drug user hair was studied using a variety of CO2/modifier mixtures. Incorporation of a triethylamine (TEA)/water modifier mixture provided dramatic improvements in the recovery of cocaine from interactive matrixes. The results suggest that the SF extractability of cocaine is not limited by analyte solubility; rather, desorption of cocaine from hair binding sites is a rate-limiting step in the SFE process. A displacement SFE mechanism is hypothesized in which TEA (as the triethylammonium cation) competes with cocaine for negatively charged hair binding sites. The dependence of extractability on hair/drug binding interactions allows the differentiation of cocaine present at different discrete sites in hair based on differences in SFE behavior. These findings suggest the potential for distinguishing exogenous (i.e., environmental) from endogenous (i.e., physiological) sources of drugs in hair. In contrast to the results observed for cocaine, SFE recoveries of BZE were poor from all matrixes and under all conditions studied. Its increased polarity, the presence of an additional binding site, and the possibility of multiple charged states suggest that poor BZE recoveries may be due to both poor analyte solubility and failure to desorb the analyte from hair binding sites under the conditions employed.

Characterization of human SHC p66 cDNA and its processed pseudogene mapping to Xq12-q13.1

SHC is an adapter protein in the Ras-MAPkinase pathway that is involved in the regulation of cell growth and differentiation. The p46 and p52 isoforms are thought to be produced by the use of two alternative translation initiation sites in a 3.4-kb transcript from the SHCA gene, which maps to chromosome 1q21. The p66 isoform could be encoded by a different 3.8- or 2.8-kb transcript of the same gene or alternatively by a SHC-related gene. To characterize other putative genes coding for SHC-like proteins, primers from the 3' UTR of the SHCA gene were used to screen a yeast artificial chromosome (YAC) library by polymerase chain reaction (PCR). Two YAC clones, 20D11B and 36D1D, were isolated and used as probes for fluorescence in situ hybridization analysis. Both these probes hybridized to chromosome Xq12-q13.1. This novel SHC-related sequence was characterized by direct sequencing of vectorette library PCR products produced from clone 20D11B. A transcript of 3.2 kb that was 85% identical to the mouse Shc cDNA encoding the p66 isoform was identified. Sequence analysis demonstrated the presence of multiple stop codons identifying this isoform of SHC as a processed pseudogene. Using primers designed on the basis of the nucleotide sequence of the pseudogene, we have now amplified and sequenced a human cDNA that encodes the SHC p66 protein. Thus, we have characterized the human SHC p66 isoform cDNA and identified a processed SHC pseudogene that maps to chromosome Xq12-q13.1.

Slow-binding inhibition: the general case

Two basic kinetic mechanisms have been described to account for the slow-binding inhibition of enzyme-catalyzed reactions. One mechanism involves the slow interaction of an inhibitor with enzyme (Mechanism A), while the other involves the rapid formation of an enzyme-inhibitor complex that undergoes a slow isomerization reaction (Mechanism B). But the initial interaction of enzyme and inhibitor may not necessarily be fast so that the free enzyme and the two forms of enzyme inhibitor complex are in steady-state equilibrium. This assumption would give rise to a more general form of Mechanism B. The present study has been concerned with attempts to determine whether it might be possible to distinguish between the three possible inhibition mechanisms by steady-state kinetic techniques. The approach to the investigation has been to derive theoretical data for the most general mechanism by using three different ratios for the two rate constants that determine which mechanism applies. The progress curve data were then fitted to the rate equations that describe the other two mechanisms. The results draw attention to the difficulties of deducing that experimental data conform to the most general mechanism. They also show how the values for the kinetic parameters, as determined from fits of the data to the equations that describe Mechanisms A and B, can be considerably in error.

Excitatory and inhibitory A- and C-reflexes in pelvic parasympathetic efferent nerves elicited by single shock to A and C afferent fibers of perineal and limb somatic nerves in anesthetized rats

The effects of single electrical shocks to myelinated A and unmyelinated C afferent fibers of perineal and limb somatic nerves on the reflex discharges in pelvic parasympathetic (L6/S1) efferent nerves to the bladder were examined in anesthetized central nervous system (CNS)-intact and acute spinal rats. When the bladder was empty, stimulation of perineal somatic inputs to the L6 and S1 segments from the perineo-femoral branch of a pudendal nerve produced excitatory A- and C-reflex discharge components in postganglionic parasympathetic efferent nerve branches on the bladder surface. When the bladder was expanded and pelvic efferent neurons were rhythmically active, additional inhibitory A- and C-reflex components could be seen. After acute spinal transection, the same stimuli elicited excitatory A- and C-reflex discharges of similar latency as those observed before the spinal transection, but were of larger amplitude and longer duration; resting activity in the pelvic nerve was low, and no evoked inhibitory reflex components could be observed. Electrical stimulation of afferents in the tibial nerve had no effect when the bladder pressure was low, but when the bladder was distended, early and late components of reflex inhibition and excitation of parasympathetic activity were visible in CNS-intact rats; these reflex responses were abolished following spinalization.

The nitric oxide synthase inhibitor L-NAME reduces inhibitory components of somato-vesical parasympathetic reflexes in the rat

Reflex discharges of pelvic postganglionic parasympathetic efferent fibers on the bladder surface induced by afferent volleys in the hindlimb nerve have been recorded in anesthetized rats, and the effects of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME) on the reflex discharges have been investigated. Single electrical stimulation of the tibial nerve at intensities supramaximal for excitation of A- and C-afferents evoked a reflex discharge in the postganglionic parasympathetic efferents with four distinct components, i.e., two inhibitory components with latencies of 49 and 203 ms, respectively, and two excitatory components with latencies of 126 and 308 ms, respectively. These reflexes could be observed when the bladder was expanded, but not markedly when the bladder was empty. Intravenous administration of L-NAME resulted in (a) a reduction in the level of resting discharge, (b) a reduction in the size of the first inhibitory component, (c) the disappearance of the second inhibitory component and (d) the exaggeration of the late excitatory component. Intracisternal injection of L-NAME caused changes similar to those observed following intravenous injection. The results suggest that inhibitory components of the somato-pelvic parasympathetic reflex are mediated by pathways that utilize nitric oxide as a neurotransmitter or neuromodulator at the level of the brainstem.

Non random usage of T cell receptor alpha gene expression in atopy using anchored PCR

The T cell receptor (TCR) alpha beta heterodimer recognises antigenic peptide fragments presented by Class II MHC. This interaction initiates T cell activation and cytokine release with subsequent recruitment of inflammatory cells. Previous work from our group suggests a qualitative difference in variable alpha gene expression in atopy as compared to non atopic controls. In this study we examine TCR alpha repertoire using anchored PCR to provide a quantitative assessment of the V alpha and J alpha repertoire. One atopic (DRB1*0701,DRB1*15: DRB4*0101, DRB5*01: DQB1* 0303, DQB1*601/2) and one non-atopic (DRB1*0701,DRB1*03011/2: DRB4*01, DRB3*0x: DQB1* 0303, DQB1*0201/2) control were studied. Variable gene usage was markedly limited in the atopic individual. V alpha 1, 3, 8 accounted for 60% and J alpha 12, 31 30% of the gene usage. There was evidence of preferential V alpha-J alpha gene pairing and clonal expansion. We conclude that there is a marked non random TCR alpha gene distribution in atopy using both V alpha family and anchored PCR. This may be due in part to antigen driven clonal expansion.

Multiple mechanisms of heterologous beta-adrenoceptor regulation in rat uterus

The inhibitory effects of catecholamines on rat myometrium mediated by beta-adrenoceptors are modulated by ovarian steroids. Previously reported findings of radioligand binding studies on myometrial membranes have demonstrated changes in the numbers of beta-adrenergic binding sites following ovarian steroid treatment. However, these changes were not accompanied by parallel functional changes. In the present study, we have investigated possible mechanisms of heterologous beta-adrenoceptor regulation by ovarian steroids. Binding studies were performed on myometrial membrane and cytosolic preparations from rats which had been ovariectomized and subsequently received no hormonal treatment or had been treated with oestradiol, progesterone or combined oestradiol and progesterone. The beta-adrenergic antagonist [125I]iodocyanopindolol and the unlabelled competing agonist, isoprenaline, were used in the present studies. Hormonal treatment had no effect on the concentration of beta-adrenergic binding sites in the myometrium (i.e. the number of membrane-bound and cytosolic binding sites per mg protein). However, significant changes were found in the total number of binding sites; these were associated with the hormone-induced tissue hypertrophy. In myometrium from ovariectomized-alone rats, approximately 50% of beta-adrenergic binding sites were present in the cytosolic fraction. Oestradiol treatment, either on its own or in combination with progesterone, resulted in the translocation of binding sites to the cell membrane. However, in the absence of progesterone only 33% of the membrane-bound binding sites bound the beta-adrenergic agonist, isoprenaline, with a high affinity, suggesting that the majority of these membrane-bound binding sites represented non-functional beta-adrenoceptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokine expression in normal, atopic, and asthmatic subjects using the combination of sputum induction and the polymerase chain reaction

BACKGROUND

The importance of cytokines in the asthmatic inflammatory response is becoming apparent. The aim of this study was to determine whether the non-invasive method of induced sputum combined with the polymerase chain reaction would allow the detection of messenger RNA (mRNA) encoding a range of cytokines on a qualitative basis.

METHODS

Four groups were studied comprising 10 normal subjects, six atopic, 10 mild and five moderately severe asthmatic subjects. Sputum was induced by the inhalation of nebulised 3.5% saline and total RNA extracted from the expectorated cells. Expression of cytokine message within induced sputum was examined by reverse transcription and the polymerase chain reaction (PCR) using primers specific for a range of cytokines (IL-1 alpha, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, RANTES, TNF alpha, IFN alpha, IFN gamma). Presence or absence of the signal was determined at 35 and 70 cycles of PCR by electrophoretic size fractionation on ethidium bromide stained agarose gels.

RESULTS

Cytokine message was detectable in sputum by this method. All samples showed a positive result for actin control. Analysis of signal for the cytokines in all subjects showed that, at 70 cycles, IL-1, IL-5, IL-8, and TNF alpha were detected in more subjects than would be expected by chance. IL-5 mRNA was detected in more of the asthmatic patients (moderate 80%, mild 40%) than in the atopic subjects (33%), who in turn showed expression of this cytokine in more individuals than nonatopic subjects (10%).

CONCLUSIONS

The combination of sputum induction and PCR appears to be a useful, non-invasive tool to explore the chronic inflammation of asthma and possibly other lung disorders. It should enable differences between normal and asthmatic subjects to be identified for future confirmation by quantitative techniques.

Effects of denervation on muscarinic receptors in the rat bladder

OBJECTIVE

To demonstrate the specific distribution of muscarinic receptors in the rat urinary bladder and to investigate the effects of afferent and efferent denervation on the density and distribution of muscarinic receptors.

MATERIALS AND METHODS

Urinary bladders were obtained from female rats which had been injected with vehicle (control), or neonatally with capsaicin (NC, afferent denervation) or which had their pelvic plexus removed (post-ganglionic denervation, PGD, efferent denervation). Tissue sections were used in radioligand-binding studies and for autoradiography with the muscarinic receptor ligand l-quinuclidinyl[phenyl-4-3H]benzilate (QNB).

RESULTS

Binding of QNB was saturable and specific to a single population of binding sites, with a mean dissociation constant (Kd) of 1.05 +/- 0.14 nM in controls and 0.90 +/- 0.13 nM in rats with PGD. Post-ganglionic denervation caused a 37% increase in maximal binding (Bmax) of QNB from 437.1 +/- 39.1 fmol/mg protein (control group) to 599.1 +/- 4.5 fmol/mg protein (P < 0.02). Autoradiograms revealed muscarinic binding sites over the smooth muscle, but none over the epithelium. Smooth muscle binding sites were doubled after PGD but were unchanged after NC treatment.

CONCLUSION

Muscarinic receptors were localized over the smooth muscle of the rat bladder and were increased after post-ganglionic denervation. This increase may be responsible for the increased sensitivity to muscarinic agonists reported to occur after bladder denervation.

Long-lasting facilitation and depression of periurethral skeletal muscle following acupuncture-like stimulation in anesthetized rats

The effects of acupuncture-like stimulation on the tone of the partially filled bladder and on the periurethral electromyogram (EMG) were examined in urethane-anesthetized rats. Acupuncture-like stimuli were usually applied to the skin and underlying muscles (or other structures), either separately or together, for a period of 1 min; the effects were studied in spinal cord intact and in spinalized animals. Maps have been constructed showing the effects of acupuncture-like stimulation at different sites on the body surface and of similar stimulation applied to individual muscles, the urethra and the testis. When acupuncture-like stimuli were applied to the skin and underlying structures, in the rostral half of the body and the hindpaw, testis or urethra, these stimuli usually induced excitation of periurethral EMG activity. Depression of EMG activity was seen predominantly during stimulation of structures close to the urethra, but not opposed to it. When acupuncture-like stimuli were applied only to structure beneath the skin, depression of EMG activity usually occurred. Acupuncture-like stimulation of the bulbocavernosus, which partly overlies the proximal urethra produced depression of EMG activity in 50% of trials, but the incidence of similar effects from the more distant pubococcygeus, or the dorsal or ventral sacrococcygeal muscles was about 90-100%. Acupuncture-like stimulation for 1 min could produce either excitation or depression of periurethral EMG activity lasting about 5 or 6 min, depending on the site of insertion and rotation of the acupuncture needles. Excitation of short duration (less than 3 min) was consistently observed from areas of the body distant to the bladder, i.e. the nose, forepaw, forelimb, chest, abdominal wall and hindpaw. Longer lasting excitation of EMG activity was often seen from the penile urethra, perineal area and hindlimb. Depression of EMG activity with a duration of more than 3 min was consistently seen from the muscles at the base of the tail (sacrococcygeus) and perineal area (pubococcygeus and bulbocavernosus). The bladder was partially filled in these experiments, so that micturition contractions were never seen; acupuncture-like stimulation of the perineal area induced some increase in bladder tone in 40% of trials. In spinalized animals, the pattern of activity induced by acupuncture-like stimulation was similar to that seen in spinal cord intact animals and the durations of the effects were not significantly different in these two groups. The distribution of sites from which acupuncture-like stimuli can influence the activity of the lower urinary tract is discussed.

The influence of afferent inputs from skin and viscera on the activity of the bladder and the skeletal muscle surrounding the urethra in the rat

(1) Somato-visceral and viscero-visceral reflex interactions have been studied in the bladder branches of the pelvic nerve and in the electromyographic (EMG) activity of the periurethral skeletal muscles of the anesthetized rat, and by observations of changes in bladder motility. (2) Slow distensions of the bladder caused some elevation of intravesical pressure, and culminated in a micturition contraction. Periurethral EMG activity increased gradually during the bladder distension, and showed an oscillatory marked increase during the bladder contraction. There was a small increase in pelvic nerve efferent activity during slow distension, and there was a substantial increase before, or at the start, of a micturition contraction. (3) Oscillatory bursting activity occurred in recordings of the EMG activity from periurethral skeletal muscle during the rising phase of micturition contraction; this was particularly so during the most rapid rise in intravesical pressure, and periods of electrical silence lasting 80-270 ms alternated with bursts of activity in the periurethral EMG. (4) In the present experiments, the switching mechanism activated by pelvic afferent signals related to intravesical pressure reversed the behavior of a number of reflex pathways. When the bladder pressure was low, nociceptive pinching of the perineal skin usually caused bladder contraction and a rise in pelvic nerve efferent activity and in periurethral EMG activity. When the bladder was full, micturition contractions were present and reduced in size and frequency by pinching of the perineal skin. The pelvic nerve efferent activity was correspondingly reduced, while the EMG activity increased during and following the nociceptive stimulus. Cooling the scrotal skin with ice also decreased the frequency of bladder contractions. (5) When the bladder pressure was low, distension of the anus and colon increased periurethral EMG activity, but did not affect bladder tone. However, when the bladder was full, these stimuli reduced the size and frequency of bladder contractions, associated with a reduction in the pelvic nerve efferent activity. There was usually a simultaneous reduction in the EMG activity in periurethral muscles. Similar results were obtained during distension of the seminal vesicles or vagina, or following injection of 20-60 microliters of saline into the lumen of the vas deferens. Reversal of the responses at extremes of intravesical pressure was observed in every case. (6) Following spinal transection at the upper cervical or thoracic level, micturition contractions were absent at high bladder volumes. However the effects described when the neuraxis was intact and the bladder pressure was low were still observed.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of pregnancy and parturition on the substance P content of the rat uterus: uterine growth is accompanied by hypertrophy of its afferent innervation

The afferent innervation of the uterus might be expected to grow during pregnancy as the size of the uterus increases. Substance P-like immunoreactivity (SPLI) has been measured as a means of monitoring the changes in the afferent innervation of the urogenital tract of rats during pregnancy and following parturition. The great growth of uterine tissue during pregnancy causes an overall decrease in SPLI concentrations during pregnancy, but it has been found that the amount of SPLI present per uterine horn increases nearly 3-fold by the end of pregnancy. This increase is greater in uterine horns that contain more fetuses, suggesting that the SPLI innervation expands to a greater extent in uterine horns that undergo greater degrees of hypertrophy. There is a significant correlation between SPLI content and the number or total weight of fetuses throughout the latter two-thirds of pregnancy. There is a fall in SPLI content of uterine horns following parturition, but not to a statistically significant degree, and this may be related to the release of the peptide during parturition.

The effects of pregnancy and parturition on the levels of substance P-like immunoreactivity in different areas of the hypothalamus

1. The concentrations of substance P-like immunoreactivity (SPLI) have been measured in the rostral and caudal areas of the hypothalamus of male rats and of virgin, pregnant and puerperal female rats. 2. The rostral:caudal ratio of SPLI is similar in males and virgin females, but diminishes in pregnancy and decreases further during the puerperium. In the pre-optic area, the SPLI concentration fell significantly during parturition, from 241.8 to 177.2 pmols/g wet weight (P < 0.05), and in the medio-basal hypothalamus, the concentration rose during pregnancy and parturition, from 87.4 to 145.5 pmols/g wet weight (P < 0.001). 3. The results are discussed in relation to the endocrine and nociceptive aspects of pregnancy and parturition.

The temporal and cellular expression of c-fos and c-jun in mechanically stimulated rabbit latissimus dorsi muscle

The levels of c-fos and c-jun mRNA were measured by reverse transcription PCR in the rabbit latissimus dorsi muscle following three separate training regimes, i.e. passive stretch, 10 Hz electrical stimulation or a combination of the two. Both c-fos and c-jun mRNA expression peaked at around 1 h after imposing stretch and at around 4.5-6 h after the initiation of electrical stimulation. The combined stretch/electrical stimulation regime induced biphasic expression of both c-fos and c-jun mRNA, with peaks coinciding temporally with those for the individual regimes. Immunostaining with anti-Fos and anti-Jun antibodies revealed the accumulation of these proteins in both myofibre and interstitial cell nuclei following passive stretch. In contrast, following electrical stimulation the localization of immunoreactive c-Fos and c-Jun proteins was predominantly in interstitial cell nuclei. c-Fos and c-Jun immunoreactivity was also clearly colocalized in a proportion of myonuclei from stretched muscle. These findings suggest that the rapid induction of c-fos and c-jun is an early event in response to mechanical stretch and might trigger [via activator protein-1 (AP-1) transcriptional factors] events leading to muscle fibre hypertrophy. However, the involvement of AP-1 in inducing the phenotypic changes in muscle fibres as a result of electrical stimulation appears less clear.

Yeast artificial chromosome cloning of the beta-catenin locus on human chromosome 3p21-22

beta-Catenin has emerged as an important component of the adherens junctions between epithelial cells. As a result of studies of its interaction with the APC gene product, it has been implicated in the development of colorectal cancer. alpha-Catenin, beta-catenin, E-cadherin and APC appear to mediate contact inhibition in epithelia. As part of the study of the organization of the beta-catenin gene, we have isolated yeast artificial chromosomes (YACs) to characterize its intron/exon structure. YAC fluorescence in situ hybridization analysis and polymerase chain reaction analysis of somatic cell hybrid DNAs show that beta-catenin maps in the 3p21-22 region, the location of tumour-suppressor genes deleted in small-cell lung cancer (SCLC) and other disorders. beta-Catenin YACs will provide a source of microsatellite markers useful in loss of heterozygosity studies to assess the importance of beta-catenin deletions in SCLC.

The effects of aging on the rat bladder and its innervation

1) Measurements of the cystometrogram, of the responsiveness of bladder muscle to pelvic nerve efferent stimulation and of the sensitivity of the pelvic nerve afferents to pressure and volume during distensions have been made in the bladders of young adult (2-3 months) and aged (26-29 months) rats, anesthetized with mixtures of urethane and chloralose. 2) The pressure-volume relationship differed in young adult and aged rats. The bladders of the aged rats held up to nearly six times the volume of the young animals, and these volumes were accommodated at lower pressures in the aged animals. The pressure at which micturition contractions appeared was similar in young adult and aged animals. 3) The passive pressure associated with each of a series of distending volumes was recorded when a pelvic nerve was cut unilaterally. The distal cut end of this cut pelvic nerve was stimulated for 10 s at 20 Hz, using square wave pulses of 10 V and 1.0 ms. The active pressure-volume relationship was constructed from this data. Both the active and the passive relationships were shifted to the right in the aged animals, and it was evident that aging was associated with a reduction in the maximal pressure generated during pelvic nerve stimulation. Also the change in intravesical pressure induced by bladder contraction was less in aged animals. 4) The most sensitive mechanoreceptor afferents appear to have pressure and volume thresholds that do not change significantly during aging. While the distension-sensitive afferents in the pelvic nerve appear to have a similar sensitivity to intravesical pressure in young adult and aged rats, they were less able to monitor volume in the aged animals. The stimulus response relationship for volume was often less steep in the aged animals. 5) In this study, aging was shown to be associated with a large increase in bladder volume and a reduced sensitivity of pelvic nerve afferents to volume, and a reduced ability to raise bladder pressure during contraction of bladder smooth muscle. The changes in bladder function associated with aging are discussed.

Effect of mechanical stimulation of the skin on the external urethral sphincter muscles in anesthetized cats

Experiments were performed using anesthetized cats to examine the effects of cutaneous stimuli on the external urethral sphincter (EUS) activity and bladder motility, 1) when the bladder volume was changed from low to high, and in the latter case, in the presence or absence of micturition contractions, 2) in different neurological states, viz., in animals with an intact neuraxis and in acute or chronic spinal preparations. In animals with an intact neuraxis, when the volume of the bladder was low, the bladder was quiescent and noxious mechanical stimulation of the perineal skin produced abrupt and marked increases both in vesical pressure and EUS activity. Similar results were observed in acute spinal as well as chronic spinal animals. The effect of the stimulus was particularly potent in chronic spinal animals. In animals with an intact neuraxis, when the volume of the bladder was increased, rhythmic micturition contractions were produced and noxious stimulation of the perineal skin slowed the frequency of the large rhythmic micturition contractions of the bladder and increased the EUS activity. These effects in animals with an intact neuraxis were substantially similar to those in chronic spinal cats showing synergic states. The effects of these somatic stimuli on the integration and coordination of bladder motility (controlled mainly by the parasympathetic pelvic efferent nerves) and EUS activity (controlled by somatic pudendal efferent nerves) are discussed.

Bambuterol: effective in nocturnal asthma

Bambuterol was compared with placebo in 28 patients with nocturnal asthma in a randomized, double-blind cross-over study. All patients were symptomatic despite taking inhaled beta 2-agonists, inhaled corticosteroids (in 26 patients the median daily dose was 1500 micrograms) and oral corticosteroids (in eight patients the median daily dose was 10 mg). Patients demonstrated > or = 20% overnight fall in peak expiratory flow (PEF) for at least half of the 14-day run-in period. They then entered two treatment periods lasting 14 days when bambuterol 20 mg nocte and placebo were given in random order. Compared to placebo, bambuterol produced a 16% improvement in mean PEF on waking (271 l min-1 vs. 239 l min-1 P = 0.0002) and a 10% improvement in evening PEF measured 24 h after drug intake (318 l min-1 vs. 296 l min-1 P = 0.01). Bambuterol significantly reduced frequency of nocturnal awakening from 1.1 to 0.7 per night (P = 0.01) and nocturnal beta 2-agonist use from 2.7 to 2.1 puffs (P = 0.0004). Other nocturnal symptoms: cough, wheeze and dyspnoea were also significantly reduced during bambuterol treatment and patients quality of sleep was improved. The results indicate bambuterol (20 mg nocte) provides effective nocturnal bronchodilation with sustained effect for 24 h and may have a useful therapeutic role in the control of symptomatic nocturnal asthma.

Effects of inhaled capsaicin in heart-lung transplant patients and asthmatic subjects

We have studied the effects on FEV1 of inhaled capsaicin in concentrations of 3 x 10(-6) to 3 x 10(-1) mg/ml and methacholine (1 to 16 mg/ml) in 15 heart-lung transplant (HLT) patients who had undergone recent transbronchial lung biopsy to determine the relationships in chronically denervated lungs between these different forms of airway hyperreactivity and inflammation. A total of 10 normal subjects and 17 asthmatic subjects were included for comparison. Capsaicin caused bronchodilation in eight HLT patients (FEV1 rising by 6.4 to 26.8%) and bronchoconstriction in two (fall in FEV1 of 7.2 and 7.6%). By contrast, seven asthmatic subjects developed bronchoconstriction after capsaicin (fall in FEV1 5.6 to 40.4%); the remaining 10 asthmatic subjects showed no response. Bronchial hyperresponsiveness to methacholine was most evident in the asthmatic subjects, but six HLT patients demonstrated a > or = to 20% fall in FEV1 with < or = 8 mg/ml of methacholine. All normal subjects were nonresponsive to both agents, and all normal and asthmatic subjects, unlike HLT patients, coughed with capsaicin. No relationship existed between the methacholine and capsaicin responses. In the HLT patients neither form of airway responsiveness was related to the degree of inflammation seen on transbronchial lung biopsy. The results suggest that in normal subjects, although it provokes cough, inhaled capsaicin causes little airway narrowing.(ABSTRACT TRUNCATED AT 250 WORDS)