Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

[Occurrence of Giardia cysts and Cryptosporidium oocysts in swimming pools in the province of Palermo, Italy]

21 samples of waters of 7 swimming pools in the province of Palermo were investigated for the presence of Giardia cysts and Cryptosporidium oocysts. Some chemio-physical parameters (chlorine, temperature, turbidity and pH) were also evaluated as well as the presence of bacterial indicators of faecal (total coliforms, Escherichia coli and enterococci), mucocutaneous and environmental (Staphylococcus aureus and Pseudomonas aeruginosa) contamination. All samples were negative for bacterial indicators of faecal contamination; 3 were positive for the presence of coagulase-negative staphylococci, 1 was positive for Alcaligenes spp. and 2 for Pseudomonas aeruginosa. 8 samples proved to be positive for Giardia and 6 also for Cryptosporidium. All but one of them were coming from waters of 2 swimming pools of the same recreational center. In all samples the concentration of Giardia was substantially higher than that of Cryptosporidium. This study shows that the disinfection and filtering plants are not always suitable to ensure a good level of the quality of the waters of swimming pools and suggests that should be necessary to check them also for the presence of protozoa like Giardia and Cryptosporidium, which may be responsible for gastroenteritis.

[Development of a technique for recovering Giardia cysts and Cryptosporidium oocysts from fresh vegetables]

Techniques described for recovering Giardia and Cryptosporidium (oo)cysts from fruit and vegetables are generally inadequate and present variable recovery efficience and elevated costs. The aim of our study was to evaluate the recovery efficiency of a simple and economic technique to apply either to berry vegetables, like tomatoes and peppers, or to large leave vegetables, like lettuce and chicory. The method include contamination and further elution of the vegetables. Then sedimentation of (oo)cysts by centrifugation of the eluate of vegetables and their visualization by means of direct immunofluorescence. The higher recovery values for both protozoa were obtained in large leave vegetables with mean data above 70% for Giardia and 76% for Cryptosporidium, whereas the values observed in the berry vegetables were above 43% for Giardia and above 37% for Cryptosporidium on average.

[Occurrence of Giardia and Cryptosporidium in wastewater, surface water and ground water samples in Palermo (Sicily)]

This paper reports the investigation carried out on the occurrence of Cryptosporidium and Giardia (oo)cysts in water samples of two municipal treatment plants, and in surface water and ground water wells of the province of Palermo. The wastewater samples taken before and after treatment process were assayed over the course of one year Giardia cysts were detected in all samples throught the year at higher concentration levels than Cryptosporidium oocysts, with a peak observed in spring. The overall removal efficiency of (oo)cysts in the treatment plants was about of 90%. Their presence were also searched in surface waters (three artificial lakes and one river); (oo)cysts were detected in one lake at very low concentration; on the contrary, both parasites were found at high concentration levels in all the samples collected throught one year from the water of the river. The pattern of occurrence of both parasites appears temporally related to the level of rainfall trend. Cryptosporidium and Giardia were also found in ground water wells; their presence occurred only in waters taken from wells at a depth lower than 31 meters with concomitant presence of faecal bacteria. These results may provide further insight into the possible source of Cryptosporidium and Giardia in natural environmental and stress the potential risk associated with the use of waters for recreational and agricultural purposes.

Coronary stenting versus coronary bypass surgery in patients with multiple vessel disease and significant proximal LAD stenosis: results from the ERACI II study

PURPOSE

To compare percutaneous coronary intervention (PCI) using stent implantation versus coronary artery bypass graft (CABG) in patients with multiple vessel disease with involvement of the proximal left anterior descending coronary artery (LAD).

METHODS

230 patients with multiple vessel disease and severe stenosis of the proximal LAD (113 with PCI, 117 with CABG). They were a cohort of patients from the randomised ERACI (Argentine randomized trial of percutaneous transluminal coronary angioplasty versus coronary artery bypass surgery in multivessel disease) II study.

RESULTS

Both groups had similar baseline characteristics. There were no significant differences in 30 day major adverse cardiac events (death, myocardial infarction, stroke, and repeat procedures) between the strategies (PCI 2.7% v CABG 7.6%, p = 0.18). There were no significant differences in survival (PCI 96.4% v CABG 95%, p = 0.98) and survival with freedom from myocardial infarction (PCI 92% v CABG 89%, p = 0.94) at 41.5 (6) months' follow up. However, freedom from new revascularisation procedures (CABG 96.6% v PCI 73%, p = 0.0002) and frequency of angina (CABG 9.4% v PCI 22%, p = 0.025) were superior in the CABG group.

CONCLUSION

Patients with multivessel disease and significant disease of the proximal LAD randomly assigned in the ERACI II trial to PCI or CABG had similar survival and survival with freedom from myocardial infarction at long term follow up. Repeat revascularisation procedures were higher in the PCI group.

Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. ERACI II Investigators

OBJECTIVE

The purpose of this study was to compare percutaneous transluminal coronary revascularization (PTCR) employing stent implantation to conventional coronary artery bypass graft surgery (CABG) in symptomatic patients with multivessel coronary artery disease.

BACKGROUND

Previous randomized studies comparing balloon angioplasty versus CABG have demonstrated equivalent safety results. However, CABG was associated with significantly fewer repeat revascularization procedures.

METHODS

A total of 2,759 patients with coronary artery disease were screened at seven clinical sites, and 450 patients were randomly assigned to undergo either PTCR (225 patients) or CABG (225 patients). Only patients with multivessel disease and indication for revascularization were enrolled.

RESULTS

Both groups had similar clinical demographics: unstable angina in 92%; 38% were older than 65 years, and 23% had a history of peripheral vascular disease. During the first 30 days, PTCR patients had lower major adverse events (death, myocardial infarction, repeat revascularization procedures and stroke) compared with CABG patients (3.6% vs. 12.3%, p = 0.002). Death occurred in 0.9% of PTCR patients versus 5.7% in CABG patients, p < 0.013, and Q myocardial infarction (MI) occurred in 0.9% PTCR versus 5.7% of CABG patients, p < 0.013. At follow-up (mean 18.5 +/- 6.4 months), survival was 96.9% in PTCR versus 92.5% in CABG, p < 0.017. Freedom from MI was also better in PTCR compared to CABG patients (97.7% vs. 93.4%, p < 0.017). Requirements for new revascularization procedures were higher in PTCR than in CABG patients (16.8% vs. 4.8%, p < 0.002).

CONCLUSIONS

In this selected high-risk group of patients with multivessel disease, PTCR with stent implantation showed better survival and freedom from MI than did conventional surgery. Repeat revascularization procedures were higher in the PTCR group.

Inhibition of neutral endopeptidase potentiates bronchoconstriction induced by neurokinin A in asthmatic patients

The endogenous tachykinins exhibit a range of properties which may be relevant in the pathophysiology of asthma. Their effects on the airways seem to be modulated by a variety of lung peptidases, including neutral endopeptidase (NEP). In order to evaluate the potential role of endogenous NEP activity in modulating tachykinins-induced bronchoconstriction in man in vivo, six atopic asthmatic patients, with a mean FEV1 value of 3.38 +/- 0.76 l, and a histamine PD20 mean value of 0.024 mg, were studied. The influence of inhaled phosphoramidon (a potent NEP inhibitor) was examined against the NKA-induced bronchospasm in a double-blind, placebo-controlled randomized study. Changes in airway calibre were followed as FEV1 and agonists responsiveness expressed as PD20 and PD15 for histamine and NKA respectively. Patients received nebulized phosphoramidon sodium salt (10(-5) M) or a control solution 10 min prior to the bronchoprovocation test with NKA. No significant difference was noticed between any of the study days and after inhaled phosphoramidon on baseline FEV1 values (3.29 +/- 0.90 l) in comparison with the control solution (3.31 +/- 0.79 l). Inhaled NKA produced a dose-dependent fall in FEV1 values in all the subjects studied with a mean PD15 value of 20.91 x 10(-9) mol. Phosphoramidon administered by inhalation elicited a significant (P < 0.01 vs baseline and control solution) potentiation in the airway responsiveness to inhaled NKA, the NKA PD15 value decreasing to 9.45 x 10(-9) mol. The present study confirms that inhaled NKA induces a dose-related bronchoconstriction in asthmatic patients and demonstrates that inhaled phosphoramidon potentiates NKA-induced bronchoconstriction.

Effect of oral terfenadine on bronchoconstrictor response to inhaled neurokinin A and histamine in asthmatic subjects

Neurokinin A (NKA) elicits a potent contractile effect in asthmatic airways. Its mechanism of action in bronchial asthma is still unknown. Recent work supports the view that NKA may stimulate mediator release from mast cells. To investigate the relative contribution of mast cell degranulation to the action of NKA, a randomized, double-blind study has been undertaken, to evaluate the effect of a potent and selective histamine H1-receptor antagonist, terfenadine (180 mg q.d., for three days), on bronchoconstriction provoked by inhaled NKA in six asthmatic subjects. Bronchial provocation tests with histamine were included in this study as control challenge. In the subjects studied, oral terfenadine, when compared to placebo, significantly increased the geometric mean (range) provocation dose of inhaled histamine required to reduce forced expiratory volume in one second (FEV1) by 20% of baseline (PD20) from 0.05 (0.03-0.08) mg (0.16 (0.10-0.26) mumol) to 1.19 (0.63-2.04) mg (3.88 (2.05-6.64) mumol). However, terfenadine failed to increase the airway responsiveness to NKA in all of the subjects studied, the geometric mean (range) PD15 NKA value being 0.94 (0.47-2.49) micrograms (8.36 (4.14-21.9 nmol) and 0.75 (0.48-1.59) micrograms (6.62 (4.23-14.0) nmol) after placebo and terfenadine, respectively. We conclude that NKA is a potent bronchoconstrictor agonist in asthma, being approximately 19 times more potent than histamine in molar terms. In this study on a small number of subjects, pharmacological intervention with oral terfenadine failed to achieve significant protection of the airways against the constrictor effect of NKA.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of oral terfenadine on bronchoconstrictor response to inhaled neurokinin A and histamine in asthmatic subjects

Neurokinin A (NKA) elicits a potent contractile effect in asthmatic airways. Its mechanism of action in bronchial asthma is still unknown. Recent work supports the view that NKA may stimulate mediator release from mast cells. To investigate the relative contribution of mast cell degranulation to the action of NKA, a randomized, double-blind study has been undertaken, to evaluate the effect of a potent and selective histamine H1-receptor antagonist, terfenadine (180 mg q.d., for three days), on bronchoconstriction provoked by inhaled NKA in six asthmatic subjects. Bronchial provocation tests with histamine were included in this study as control challenge. In the subjects studied, oral terfenadine, when compared to placebo, significantly increased the geometric mean (range) provocation dose of inhaled histamine required to reduce forced expiratory volume in one second (FEV1) by 20% of baseline (PD20) from 0.05 (0.03-0.08) mg (0.16 (0.10-0.26) mumol) to 1.19 (0.63-2.04) mg (3.88 (2.05-6.64) mumol). However, terfenadine failed to increase the airway responsiveness to NKA in all of the subjects studied, the geometric mean (range) PD15 NKA value being 0.94 (0.47-2.49) micrograms (8.36 (4.14-21.9 nmol) and 0.75 (0.48-1.59) micrograms (6.62 (4.23-14.0) nmol) after placebo and terfenadine, respectively. We conclude that NKA is a potent bronchoconstrictor agonist in asthma, being approximately 19 times more potent than histamine in molar terms. In this study on a small number of subjects, pharmacological intervention with oral terfenadine failed to achieve significant protection of the airways against the constrictor effect of NKA.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effects of inhaled ipratropium bromide on bronchoconstriction induced by adenosine and methacholine in asthma

Although adenosine-induced bronchoconstriction is mainly due to mast cell mediator release, vagal reflexes have also been implicated in this response. We have investigated the effect of a specific muscarinic-receptor antagonist, ipratropium bromide, on methacholine- and adenosine-induced bronchoconstriction in a randomized, placebo-controlled, double-blind study of 12 asthmatic subjects. Airway response was evaluated as forced expiratory volume in one second (FEV1). Inhaled ipratropium bromide (40 micrograms), administered 20 min prior to bronchoprovocation, increased the provocation dose of inhaled methacholine and adenosine required to reduce FEV1 by 20% from baseline (PD20) from 0.11 to 0.79 mg (p less than 0.01) and from 0.57 to 1.27 mg (p less than 0.01), respectively. The mean baseline FEV1 values after administration of ipratropium bromide were significantly higher than after placebo administration (p less than 0.05). However, there was no correlation between the degree of bronchodilatation and dose-ratios for methacholine and adenosine. The findings of the present study implicate vagal reflexes in the bronchospastic response induced by inhaled adenosine in asthma.

Protective effects of inhaled ipratropium bromide on bronchoconstriction induced by adenosine and methacholine in asthma

Although adenosine-induced bronchoconstriction is mainly due to mast cell mediator release, vagal reflexes have also been implicated in this response. We have investigated the effect of a specific muscarinic-receptor antagonist, ipratropium bromide, on methacholine- and adenosine-induced bronchoconstriction in a randomized, placebo-controlled, double-blind study of 12 asthmatic subjects. Airway response was evaluated as forced expiratory volume in one second (FEV1). Inhaled ipratropium bromide (40 micrograms), administered 20 min prior to bronchoprovocation, increased the provocation dose of inhaled methacholine and adenosine required to reduce FEV1 by 20% from baseline (PD20) from 0.11 to 0.79 mg (p less than 0.01) and from 0.57 to 1.27 mg (p less than 0.01), respectively. The mean baseline FEV1 values after administration of ipratropium bromide were significantly higher than after placebo administration (p less than 0.05). However, there was no correlation between the degree of bronchodilatation and dose-ratios for methacholine and adenosine. The findings of the present study implicate vagal reflexes in the bronchospastic response induced by inhaled adenosine in asthma.

Protection of nedocromil sodium on bronchoconstriction induced by inhaled neurokinin A (NKA) in asthmatic patients

Neurokinin A (NKA) has been shown to exert a potent contractile action on bronchial smooth muscles both in vitro and in vivo. Although this effect seems to be due either to a direct action of this peptide on specific muscular receptors or to an indirect effect on mast cells and/or nerves, its mechanism of action in bronchial asthma is still unknown. In the present study we have investigated the airway response to inhaled NKA in 10 asthmatic subjects and the activity of the novel pyranoquinoline dicarboxylic acid drug, nedocromil sodium, on this response. Ten asthmatic patients with stable asthma took part in the study consisting of four separate visits. On the first two occasions we derived histamine and NKA PD15 values in absence of any drug treatment. On the following two visits the inhalation challenge with NKA was performed after administration of either nedocromil sodium or matched placebo administered as pressurized aerosols via metered dose inhalers in a randomized double-blind order. Inhaled NKA produced a dose-related fall in FEV1 in all the subjects studied. Inhaled nedocromil sodium had a significant effect on the FEV1 response to NKA inhalation, the geometric mean PD15 value increasing from 16.6 to 32.2 x 10(-9) mol. We conclude that nedocromil sodium attenuates subsequent responsiveness to inhaled NKA in asthmatic subjects.

Influence of antihistamine (astemizole) and anticholinergic drugs (ipratropium bromide) on bronchoconstriction induced by substance P

Several studies have demonstrated that neuropeptides are present in bronchial tissue. The aim of this study was to evaluate in vivo the influence of antihistamine in comparison to an anticholinergic drug on bronchospasm induced by inhalation of substance P (SP). Seven moderate asthmatic patients (mean age = 34.4 +/- 8.9), five being female, were studied. The acetate salt of SP was prepared in 0.9% saline to produce a dose range of 23 to 184 x 10(-6) mol. Patients were studied on three separate days with an interval of 3 weeks between challenges. On the first day the dose of SP producing a 20% change in FEV1 was calculated from the individual semilogarithmic dose-response curve. On subsequent days, in a randomized double-blind manner, the patients were treated either with astemizole (20 mg BID for three days) and placebo ipratropium bromide or with placebo of astemizole (twice a day for three days) and with pressurized aerosol of ipratropium bromide (IB) (40 micrograms 20 minutes before the challenge). Two way analysis of variance was used for statistical analysis. Our results demonstrated that inhaled SP is able to produce a dose-response curve of bronchoconstriction with a geometric mean of PD20 of 50.51 x 10(-6) moles (37.38 to 68.19 x 10(-6) mol). Treatment with astemizole induced a geometric mean PD20 of 65.51 x 10(-6) mol (33.02 to 130.21 x 10(-6) mol) and the premedication with the IB induced a significant (P less than .05) shift of dose-response curve to SP (geometric mean PD20 = 109.1 x 10(-6) mol; 58.67 to 204.05 x 10(-6) mol). Our results demonstrated that bronchoconstriction induced by SP could be attributed to a weak cholinergic activation and not to histamine release.

Tachyphylaxis to repeated challenges with inhaled adenosine in asthmatic subjects

Adenosine, when administered as an aerosol to asthmatic subjects, provokes a prompt dose-dependent bronchoconstriction. The aim of this study was to establish whether tachyphylaxis in response to repeated inhalations with adenosine occurs in asthmatic subjects. Eight asthmatic patients were studied on three separate days (days A, B, and C) at the same time of day for each subject. Three inhalation tests were performed, separated by one hour, on each study day. The study was conducted in a double-blind fashion and performed in random order. On day A, three adenosine inhalation tests were performed to assess adenosine tachyphylaxis. On day B, a saline inhalation test was carried out between two adenosine challenges to assess the time course of the adenosine tachyphylaxis. On day C, three methacholine inhalation tests were performed to confirm that tachyphylaxis does not occur to methacholine. Repeated inhalation with adenosine, but not methacholine, produced a progressive loss of responsiveness to the nucleoside, which was particularly manifest with the third challenge.

Effect of indomethacin on adenosine-induced bronchoconstriction

The exact mechanism of adenosine-induced bronchoconstriction in patients with asthma is unknown. Adenosine contraction of guinea pig trachea was antagonized by inhibitors of cyclooxygenase. The aim of this study was to investigate the effect of indomethacin (100 mg/day) on adenosine-induced bronchoconstriction in 14 asymptomatic patients with asthma. Airway response was evaluated as FEV1, and adenosine was administered as an aerosol diluted in 0.9% saline to produce a concentration range of 0.125 to 4 mg/ml. The dose of adenosine producing a 20% change in FEV1 (PD20) was calculated from the individual semilogarithmic dose-response curve; the results of PD20 were converted to log values for statistical analysis (Student's paired t test). The study was performed on 3 separate days. On the first day, the adenosine challenge was performed, and on subsequent days patients were pretreated with either placebo or indomethacin in a randomized, double-blind manner. Inhaled adenosine caused bronchoconstriction with a geometric mean PD20 of 0.71 mg (95% confidence limits, 0.44 to 1.16). After placebo, a geometric mean PD20 of 0.91 mg (95% confidence limits, 0.53 to 1.58) was obtained. Indomethacin pretreatment decreased adenosine hyperresponsiveness and shifted the dose-response curves of adenosine challenge to the right with a geometric mean PD20 of 1.28 mg (95% confidence limits, 0.64 to 2.56). The effect of indomethacin on adenosine bronchoconstriction (p less than 0.01 versus baseline; p less than 0.05 versus placebo) suggests an indirect mechanism of adenosine on inducing release of arachidonic acid derivatives. Inflammatory mediators inhibited by indomethacin may be involved in adenosine bronchoconstriction, even if this mechanism is not relevant.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung permeability in smokers after ambroxol treatment

There is evidence suggesting the involvement of the surfactant system in the development of lung diseases in cigarette smokers. The aim of the present study was to evaluate the effect of Ambroxol on lung epithelial permeability (LEP) in healthy smokers. Ambroxol is known to stimulate surfactant production. Twenty male patients aged between 20 and 60 years participated in the study. They all smoked at least 15 cigarettes daily for 10 years. We carried out a random double-blind study versus placebo: the drug (Ambroxol 75 mg) or the placebo were given once a day after breakfast for 30 days. Lung permeability was evaluated through scanning pulmonary scintigraphy by inhalation of the polydispersed liquid aerosol diethylenetriaminepentaacetic acid (DTPA), labelled with 99Tc, and delivered by a 'Venticis' system. LEP was expressed as the half-time clearance from the lung of 99Tc-DTPA (T50). The significance of the differences between the two treatments was determined by the Student's test for unpaired data. LEP was not different from the baseline value (T50 = 18.49 min) after placebo administration (T50 = 19.57 min). The patients receiving Ambroxol showed an increased LEP mean value (T50 = 18.36 min) in comparison with the baseline mean value (T50 = 16.41 min). Our results demonstrate that the treatment with Ambroxol was able to decrease LEP in 6 subjects, though not significantly.

Effect of an aerosol delivery system on bronchodilator activity

Metered dose inhalers (MDIs) are often used incorrectly by patients who find difficulty using MDI for drug inhalation. The study was performed in 11 asthmatic patients in four days in order to evaluate the efficiency of a new Drug Delivery System (DDS-InspirEase) for metered dose inhalers. Clenbuterol was administered via DDS and via conventional MDI in a randomized manner. On the first two days, DDS and MDI were used by patients without any physician's help. On the subsequent days, clenbuterol was administered via DDS and via conventional MDI directly by the physician. FEV1 and MEF75 values were measured 15', 30', one hour, and two hours post-drug inhalation. Statistical analysis (ANOVA) showed that clenbuterol delivered by DDS, administered by patients or by physician, produced a greater increase in FEV1 values (P less than .05) and MEF75 values (P less than .01) in comparison to the conventional MDI on each test day. No significant differences existed between physician or patient administration of clenbuterol with DDS and MDI. The results showed a greater bronchodilator effect obtained by clenbuterol delivered by DDS.

Comparative study of the effects of nedocromil sodium (4 mg) and sodium cromoglycate (10 mg) on adenosine-induced bronchoconstriction in asthmatic subjects

The effect of nedocromil sodium (4 mg; 7.8 X 10(-6) M) on adenosine-induced bronchoconstriction was compared with that of a higher dose of sodium cromoglycate (10 mg; 24.1 X 10(-6) M). Eleven allergic asthmatic patients (mean age 26.28 +/- 12.21 years) were studied. Adenosine (0.03-4.00 mg) was administered as nebulized aerosol. The dose of adenosine producing a 20% change in FEV1(PD20) was calculated from the individual semi-logarithmic dose-response curves. Patients were studied on 4 separate days. On the first day the adenosine challenge was performed; on subsequent days patients were pretreated (20 min before challenge) with either placebo or test drug (nedocromil sodium 2 x 2 mg or sodium cromoglycate 2 x 5 mg) administered by pressurized aerosol in a randomized, double-blind manner. Statistical analysis was performed by two-way analysis of variance. Neither sodium cromoglycate nor nedocromil sodium showed a significant bronchodilator effect. In patients treated with placebo, inhalation of adenosine produced a dose-related bronchoconstriction with a geometric mean PD20 of 0.42 mg. After drug administration the mean PD20 values were 1.29 mg with sodium cromoglycate and 2.30 mg with nedocromil sodium. Both drugs produced a significant increase in mean PD20 value in comparison with placebo and baseline (P less than 0.01). These results demonstrate that nedocromil sodium (4 mg) is significantly more potent than a larger dose of sodium cromoglycate (10 mg) in inhibiting adenosine-induced bronchoconstriction (P less than 0.05).

Effect of nedocromil on bronchospasm induced by inhalation of substance P in asthmatic subjects

Several studies have demonstrated that neuropeptides are present in peptidergic fibres of bronchial tissue. The aim of the present study was to evaluate in vivo the effect of nedocromil sodium (2 x 2 mg) on bronchospasm induced by inhalation of substance P. Six moderate asthmatic patients, mean age 25.17 years, were studied. Airway response was measured as FEV1 and the dose of substance P (using a dose range of 23-736 nmol) producing a 20% decrease in FEV1 (PD20) was calculated from the individual semilogarithmic dose-response curves. Patients were studied on 3 separate days in a randomized, double-blind manner. On the first day a baseline PD20 value was determined. On subsequent days substance P challenge was performed after pretreatment (20 min before challenge) with either placebo or nedocromil sodium. Student's paired t-test and Wilcoxon's test were used for statistical analysis. The results of this study demonstrated that inhalation of substance P causes a dose-dependent bronchoconstriction and that the bronchoconstriction induced by substance P can be prevented by pre-treatment with nedocromil sodium.

Enhancing effect of dipyridamole inhalation on adenosine-induced bronchospasm in asthmatic patients

The study was performed on 13 asthmatic patients to determine whether inhaled dipyridamole would act directly by inducing bronchoconstriction or indirectly by potentiating the adenosine-induced bronchoconstriction. The study was performed in 3 consecutive days. On the first day adenosine challenge was performed and the PD20 value calculated. On the other days the adenosine challenge was done 5 min after randomized inhalations of dipyridamole or a control solution. The mean percent change in FEV1 after dipyridamole (delta % = 2.0) and control solution (delta % = 1.0) was not significant. Inhaled adenosine caused bronchoconstriction with a geometric mean PD20 of 1.09 mg. After control solution inhalation, a mean PD20 value of 1.31 mg was observed. Dipyridamole inhalation increased adenosine hyperresponsiveness and in all subjects shifted the dose-response curves of adenosine challenge to the left with a mean PD20 value of 0.40 mg. This enhancing effect of dipyridamole was significant when compared with the baseline value (P less than 0.01) and control solution (P less than 0.01). The study demonstrated that dipyridamole inhalation increased airway responsiveness to adenosine in all subjects. This effect is due to indirect activity of dipyridamole on airways without changes in baseline airway caliber.

Bronchospasm induced by inhalation of substance P: effect of sodium cromoglycate

The aim of this study was to evaluate in vivo the effect of inhaled substance P (SP) and to determine the effect of sodium cromoglycate (SCG) on bronchospasm induced by its inhalation in 6 asthmatic patients. At the beginning of the study, all patients were asymptomatic, with an FEV1 value not less than 20%. SP was administered as aerosol, prepared in 0.9% saline to produce a dose range of 0.03-1 mg. Airway response was measured as FEV1 using a pulmonary system 47120A Hewlett-Packard instrument. The dose of SP producing a 20% change in FEV1 was calculated from the individual semi-logarithmic dose-response curve (PD20). After administration of the placebo, SP produced a dose-related bronchoconstriction with a geometric mean PD20 of 0.15 mg. After SCG, the mean PD20 value was of 0.64 mg (p less than 0.01). These results confirmed the bronchospasm induced by inhalation of SP and demonstrated that SCG is able to prevent this effect although it is impossible to define the exact mechanism of the drug.

Effect of sodium cromoglycate and nifedipine on adenosine-induced bronchoconstriction

Inhaled adenosine causes bronchoconstriction in asthmatic patients. In 7 symptom-free asthmatics a study was performed to investigate the effect of sodium cromoglycate and nifedipine on adenosine-induced bronchoconstriction. All patients were challenged with increasing doses (from 0.03 to 2 mg) of nebulized adenosine to assess airway reactivity. The same procedure was repeated on different days at the same time each morning after administration of placebo and drugs in a randomized double-blind study. Airway response was measured as the forced expiratory volume in 1 s (FEV1). The PD20 value and the fall of FEV1 at the provocative dose were calculated. The PD20 data were modified in log values and the statistical analysis was performed by two-way analysis of variance. Mean decrease of FEV1 after adenosine challenge was 26.02 and 28.87% with placebo sodium cromoglycate and placebo nifedipine, respectively. Sodium cromoglycate and nifedipine gave a mean decrease of FEV1 of 6.44% (p less than 0.05) and 22.22%, respectively. PD20 values (geometric mean) after adenosine inhalation were 0.72 and 0.74 mg for placebo sodium cromoglycate and placebo nifedipine and 0.86 mg for nifedipine. Sodium cromoglycate gave a significant protection against adenosine in all subjects and in no case did the maximum dose used (2 mg) result in a fall in FEV1 value greater than 20%. Adenosine antagonism could be considered as a possible factor contributing to the pharmacologic efficacy of sodium cromoglycate in asthmatic patients. No protective effect was noticed with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of different antihypertensive drugs on left ventricular function

Left ventricular hypertrophy (LVH) is a response by the heart to haemodynamic overload. It is frequently observed in hypertension as a consequence of work overload secondary to an increased systemic resistance. This increase is not the only cause of LVH; there are other factors which can have a significant effect on its incidence. LVH in arterial hypertension acts initially as a useful compensatory mechanism against increased peripheral resistance. However after a certain amount of time it produces changes of variable intensity which have important consequences for the heart and some of them impair cardiac performance: 1. It affects both systolic and diastolic ventricular function; 2. It reduces coronary reserve; 3. It increases the incidence of angina and heart failure; 4. It increases the incidence of ventricular arrhythmias and sudden death. It therefore seems reasonable to include the reduction of LVH among the basic aims of antihypertensive treatment. Antisympathetic drugs (methyldopa, prazosin, urapidil), adrenergic beta-blockers, calcium antagonists and the converting enzyme inhibitors have proven to have a variable degree of efficacy in effecting a regression of LVH.

Bronchodilator effect of Aerochamber and Inspirease in comparison with metered dose inhaler

This trial was performed in a randomized double-blind manner on four different days in 13 asthmatic patients in order to compare the bronchodilator efficacy of two different inhalation devices, Inspirease (IP) and Aerochamber (AC), to the conventional metered dose inhaler (MDI). The results showed that clenbuterol determined a significant FEV1 increase inhaled either via MDI or via IP and AC. IP caused a greater bronchodilatation than AC, 30 min after clenbuterol administration. IP caused a greater mean increase (P less than 0.05) in FEV1 than the MDI at all time intervals; AC provided an improvement in bronchodilator response over directly administered MDI. Such responses are only marginally clinically relevant when patients use MDI correctly. These devices are mainly indicated in patients with poor hand-lung coordination.

Relationship of serum theophylline concentrations to histamine-induced bronchospasm

This study was performed in a randomized double-blind manner on 6 separate days in 10 asthmatic patients to investigate the effect of a sustained theophylline on baseline bronchial hyperreactivity to histamine in relation to the theophylline serum levels and the degree of bronchodilatation produced. No significant bronchodilatation was seen after theophylline administration at every time of evaluation. An improvement of PD20 values of histamine was observed after 4 h (p less than 0.05), 8 h (p less than 0.01) and 12 h (p less than 0.05) from theophylline administration versus respective PD20 values obtained with placebo at the same times. No significant correlation was found between serum theophylline levels and percentage change of PD20 values after drug administration (r = 0.250). We observed an improvement of PD20 mean values in relation to the maximal serum theophylline concentration but our study failed to correlate the degree of protection with serum concentration.

Effect of nifedipine on allergen-induced bronchoconstriction

The effect of nifedipine on allergen-induced asthma in nine asthmatic subjects was studied. All subjects had a history of asthma and positive Prick test; lyophilized allergen extracts of Dermatophagoides Pteronyssinus were used. All solutions were inhaled through DeVilbiss nebulizer. On the first day baseline FEV1 value was measured, allergen extracts were inhaled at increasing doses. The procedure was repeated until a 20% fall from the baseline FEV1 was obtained. Nifedipine or placebo capsules were administered sublingually in a randomized double blind manner. Antigen challenge was given 30 minutes later by using provocating dose of allergen. The change in FEV1 value was calculated from the post nifedipine administration. A significant negative correlation (p less than 0.01) was found between the percentage of protection and the baseline PD20. Nifedipine produced a significant mean change of the bronchial reactivity threshold (p less than 0.01).

[Epidemic of viral hepatitis in a mountain community of western Sicily]

Epidemiological investigations were carried out during and after a viral hepatitis A outbreak in a mountain town, Geraci Siculo, in western Sicily. Blood samples were obtained through finger prick or by venipuncture from patients, their family contacts and from healthy school children of different age groups (3 to 15 year old). Serum markers for hepatitis A (anti HAV and IgM anti HAV) and hepatitis B (HBsAg and anti HBs) were tested. All but two of 36 cases, which occurred from August through March with a peak in November and December were under 15; 33 of them, in which laboratory data were available, were due to HAV. Seroepidemiological investigations, performed in December 1979 and in May 1980, have shown a low prevalence of anti HAV antibodies: 11.5% only of the children tested were positive in the first sampling and 22% in the second one. Also prevalence of HBV markers was low, as compared with similar observations carried out previously in other different area of Western Sicily.