Biomedical subjects

R Bossi

Publications and source records attributed to R Bossi.

At least 19 recordsLinked to original sources

PubMed2006

Reduced levels of adiponectin in sleep apnea syndrome.

BACKGROUND: To investigate adiponectin levels in an obese population with and without obstructive sleep apnea syndrome (OSAS) and the acute modifications in adiponectin after a whole-night control by auto continuous positive air pressure (CPAP). METHODS: 46 obese subjects [22 males, 24 females, age 55.1+/-11.4 yr, body mass index (BMI) 38.9+/-6.5 kg/m2]: 11 OSAS with apnea/hypopnea index (AHI) from 10/h to 30/h, 14 OSAS with AHI >30/h and 21 without OSAS. Thirty-seven normal weight healthy subjects (20 males, 17 females, age 31.3+/-9.5 yr, BMI 21.5+/-1.8 kg/m2). Serum adiponectin levels, biochemical parameters, anthropometric measurements, pulmonary function, pulse-oxymetry and polisomnography. RESULTS: The 3 groups of obese patients were comparable for gender, BMI, age, fat mass, fat free mass, hip and waist circumference, waist-to-hip ratio (WHR), systolic and diastolic blood pressure and glycometabolic parameters. Adiponectin levels were significantly reduced in obese patients compared to healthy normal weight subjects (8.1+/-3.5 vs 11.3+/-4.8 microg/ml p<0.001) In particular, adiponectin showed a trend to decrease according to the severity of OSAS. No differences in adiponectin levels were found after a whole-night control by Auto CPAP. CONCLUSIONS: OSAS is associated with reduced levels of adiponectin independently of insulin-resistance and BMI. These low adiponectin levels may contribute to the increased mortality seen in such patients.

Adiponectin↗

PubMed2003

The TB structural genomics consortium: a resource for Mycobacterium tuberculosis biology.

The TB Structural Genomics Consortium is an organization devoted to encouraging, coordinating, and facilitating the determination and analysis of structures of proteins from Mycobacterium tuberculosis. The Consortium members hope to work together with other M. tuberculosis researchers to identify M. tuberculosis proteins for which structural information could provide important biological information, to analyze and interpret structures of M. tuberculosis proteins, and to work collaboratively to test ideas about M. tuberculosis protein function that are suggested by structure or related to structural information. This review describes the TB Structural Genomics Consortium and some of the proteins for which the Consortium is in the progress of determining three-dimensional structures.

Amino Acid Sequence↗

PubMed2002

Analysis of polar pesticides in rainwater in Denmark by liquid chromatography-tandem mass spectrometry.

A new LC-MS-MS method for analysis of rainwater has been developed and validated for 53 pesticides, degradation products of pesticides and selected nitrophenols. The method was used to monitor the concentration of pesticides in rainwater at one location near Roskilde, Denmark from February 2000 to August 2000. Sampling was done in periods of up to 4 weeks using a cooled wet-only sampler. Water samples were extracted by solid-phase extraction on Oasis HLB columns. The analysis of the extracts was performed by LC-MS-MS with electrospray ionization. All samples were analysed in negative and in positive ionization mode, respectively for acidic and neutral compounds. All analyses were done in the selected reaction monitoring mode in order to obtain a better signal-to-noise ratio. The method has been validated for the following parameters: recovery, detection limit, uncertainty and linearity. Atrazine, terbuthylazine, isoproturon, mechlorprop and (2-methyl-4-chlorophenoxy)acetic acid were measured at concentrations above 0.100 microg/l, mainly during the period of agricultural use. Nitrophenols were measured at high concentrations all year with peaks in the cold season (February-March).

Chromatography, High Pressure Liquid↗

PubMed2001

Mineralisation studies of 14C-labelled metsulfuron-methyl, tribenuron-methyl, chlorsulfuron and thifensulfuron-methyl in one Danish soil and groundwater sediment profile.

Bacterial mineralisation of four sulfonylurea herbicides at 20 microg kg(-1) in a sandy soil from nine different depths in a sandy soil horizon (5-780 cm) was investigated in laboratory studies. Metsulfuron-methyl, chlorsulfuron, and tribenuron-methyl were 14C-labelled in the sulfonamide ring, while thifensulfuron-methyl was labelled in the thiophene ring. The highest mineralised amount in 126 days was observed for metsulfuron-methyl (40%) followed by tribenuron-methyl (25%), and thifensulfuron-methyl (11%). Chlorsulfuron showed low mineralisation in all the soils tested (<4%). Mineralisation of the herbicides metsulfuron-methyl and tribenuron-methyl varied according to soil depth (upper profile: 5-70 cm, and lower profile: 165-780 cm) and were proven faster in soil taken from depths 5-7 and 30-35 cm, and slower in depths 45-50 and 70-75 cm. Mineralisation was absent in the lower profile (165-780 cm). As an indicator of microbial activity bacterial counts were taken at the experimental start; these counts grouped in three levels: highest in the surface layer (5-7 cm), slightly lower in the depths 30-75 cm, and lowest in the lower profile (165-780 cm). Residual concentrations of metsulfuron-methyl correlated to the accumulated amount mineralised, with high residual concentrations in soil showing low mineralisation. Also chlorsulfuron showed high residual concentrations with increasing depth in the upper profile, but the relatively high dissipation at 30-35 cm and lower one at 45-50 cm could not be related with the lack of mineralisation. This shows that hydrolysis occurs, but mineralisation of the chloro-substituted sulfonamide is restricted. Tribenuron-methyl and thifensulfuron-methyl could not be detected due to interference with other compounds.

Arylsulfonates↗

PubMed2001

Isolation and characterisation of Rhodococcus erythropolis TA57 able to degrade the triazine amine product from hydrolysis of sulfonylurea pesticides in soils.

We isolated a bacterium capable of metabolising a methylated and methoxylated s-triazine ring as the only nitrogen source. On a weight basis, the s-triazine, commonly named triazine amine (TAM), constitutes approx. half of several sulfonylurea herbicides and is formed after hydrolysis of these herbicides. The isolate, strain TA57 was identified using multi-phasic taxonomy as a gram-positive Rhodococcus erythropolis. Strain TA57 mineralised over 50% 14C-labelled TAM within 4 days in growing cultures using all of the nitrogen for growth. The degradation capacity was found stable in cells grown on either tryptic soy broth agar plates or in minimal medium with NH4+. Among other s-triazines tested, only one other methylated, but de-methoxylated s-triazine amine supported growth. Inoculating 10(6) cells of TA57 per gram of soil (d.w.) resulted in 50% mineralisation of 14C labelled TAM (1 mg kg(-1)) within 25 days, in contrary to the indigenous population that mineralised only 6% in 50 days.

Biodegradation, Environmental↗

PubMed2000

Sleep disorders in peritoneal and haemodialysis patients as assessed by a self-administered questionnaire.

Sleep disorders have been reported as a frequent problem in dialysis patients. However, only one paper has compared the prevalence and possible causes of this complication in peritoneal (PD) and haemodialysis (HD) patients. We surveyed 84 PD and 87 HD patients about disordered sleep using a self-administered questionnaire. Forty-nine percent of PD and 56% of HD patients reported problems sleeping. These problems were rated as severe by 29 PD and 22 HD patients. Type of disturbances involved delayed sleeping (13 PD and 32 HD, p < 0.005), interrupted sleep (32 PD and 44 HD) and early morning awakening (25 PD and 37 HD). The number of hours of sleep varied widely among patients: it was 5 and 21 minutes in PD patients with sleep disorders and 7 and 37 min in PD pts without such problems. No statistically significant relationship was evidenced between sleep disorders and age, sex, body weight, obesity, duration of dialysis, dialysis dose, self-assessed sadness, anxiety, worry, pain, pruritus, dyspnoea, restless leg syndrome, use of cigarettes, caffeine, or sleeping pills. In conclusion, sleep disorders are a frequent problem in both PD and HD patients. Apparently the relationship with demographics, dialysis dose, lifestyle and personality traits is poor. The possible role of other causes should be investigated.

Chi-Square Distribution↗

PubMed1999

Determination of sulfonylurea degradation products in soil by liquid chromatography-ultraviolet detection followed by confirmatory liquid chromatography-tandem mass spectrometry.

A method based on liquid extraction followed by sample enrichment on reversed-phase solid-phase extraction was developed for the extraction of five degradation products of four sulfonylurea herbicides (chlorsulfuron, metsulfuron-methyl, thifensulfuron-methyl and tribenuron-methyl) from soil. The compounds have been quantified by LC-UV and identified by tandem LC-MS with electrospray ionization or atmospheric pressure chemical ionization. The limits of detection for the five compounds were between 10 and 50 micrograms kg-1. The method has been applied to the extraction of soil samples after microbial degradation of sulfonylurea herbicides.

Chromatography, Liquid↗

PubMed1999

Analysis of metsulfuron-methyl in soil by liquid chromatography/tandem mass spectrometry. Application to a field dissipation study.

An analytical method is described for the extraction of metsulfuron-methyl from soil at sub-parts per billion levels (LOQ = 0.2 microgram kg(-1)). The herbicide was quantitatively determined and identified by ESI LC/MS/MS. The method has been applied to a field dissipation study in which metsulfuron-methyl was applied to spring barley at three dosage rates: 4, 8, and 16 g of active ingredient ha(-)(1). The results of 2 years are presented. The dissipation rate of metsulfuron-methyl in topsoil was very rapid, with a calculated half-life of 6.5 days. Laboratory mineralization studies with native soils in contrast to autoclaved soils indicated that microbial degradation of (14)C-labeled metsulfuron-methyl and (14)C-labeled 2-amino-4-methoxy-6-methyl-1,3,5-triazine in soil microcosms is an important factor for the complete degradation of metsulfuron-methyl in the field. However, the mineralization rate of the sulfonamide was much higher.

Arylsulfonates↗

PubMed1997

Degradation of ethylenethiourea (ETU) in oxic and anoxic sandy aquifers.

Ethylenethiourea is an important degradation product of ethylenebisdithiocarbamate fungicides, which are widely used in different kinds of crops. The ethylenebisdithiocarbamate group includes maneb, zineb and mancozeb. The ethylenebisdithiocarbamates are not highly toxic and degrade rapidly in the presence of moisture and oxygen, forming different compounds. One of these is the polar ethylenethiourea, which is relatively stable. Thus, this compound appears to be a potential contaminant for groundwater. Batch experiments were carried out under biotic as well as abiotic conditions to study the degradation dependence of concentration, temperature and organic matter. The decomposition of ethylenethiourea under abiotic conditions was found to be less than 5% of the degradation under biotic conditions. Further, ethylenethiourea showed to be stable over a period of 150 days at 20 degrees C in tap water as well as in batch with soil sterilized with NaN3. The degradation of ethylenethiourea depends on the concentration in the water implying first order reaction kinetics. The microbial degradation of ethylenethiourea is highly temperature dependent with aerobic Q10 between 2.9 and 4.2, and an anaerobic between 2.1 and 2.5. A minor increase in degradation rates was observed by application of nitrate and manure to the batches. The experiments show extremely complete degradation of ethylenethiourea in the presence of microbial nitrate reduction with pyrite which occurs in deeper parts of the aquifers.

Antifungal Agents↗

PubMed1994

Levodropropizine (LD) activity in allergic asthmatic patients, challenged with ultrasonically nebulized distilled water, metacholine and allergen-induced bronchospasm.

The antitussive compound Levodropropizine (LD) is active in animal bronchoconstriction induced by histamine and capsaicin and in man protects from bronchoconstriction induced by capsaicin. The primary objective of this study was to evaluate the mechanism of action of LD given at 60 mg t.i.d. as oral drops, for 8 days by means of specific bronchial challenges (allergens) and of aspecific challenges acting via different receptors and fibers (i.e. metacholine via cholinergic receptors and ultrasonically nebulized distilled water (UNDW) via histamine and neuropeptide release). The study design is randomized, double-blind, cross-over versus placebo in 30 allergic asthmatic patients. Baseline bronchial tone and bronchoconstrictor response to metacholine (MCh) were not modified by active treatment nor by placebo. On the contrary, in airway responsiveness to UNDW, the active treatment showed an antagonist effect against induced bronchoconstriction of 59% [activity ratio (AR) as antilog = 0.41; 95% confidence interval 0.35-0.54; p < or = 0.05] in comparison to no effect for placebo. Similarly, in airway responsiveness to specific allergen, active treatment antagonized the bronchoconstrictor effect of grass pollen by 83% and of various allergens (dermatophagoides and grass pollen) by 72%, i.e. AR of 0.17 (95% confidence interval 0.045-0.65; p < 0.01) and of 0.28 (95% confidence interval 0.07-1.04; p < 0.05), respectively. No antagonist effect was evident with placebo at all times. Besides inhibiting cough, LD is also partially effective in inhibiting bronchial hyperreactive response against specific allergen and UNDW bronchoconstriction. Hence, LD might act by partly inhibiting histamine and neuropeptide release.

Administration, Oral↗

PubMed1993

Antitussive effect of oxatomide on citric acid-induced cough in conscious guinea pig. Preliminary communication.

Oxatomide (CAS 60607-34-3), a diphenylmethyl-piperazine benzimidazole derivative is a new oral antiallergic drug useful in asthma in preventing allergic attacks. Using the model of citric acid-induced coughing in the unanesthetized, unrestrained guinea pig the antitussive effect of oxatomide was investigated. The animals were treated with logarithmically increasing doses of oxatomide (0.5, 1, 2 mg/kg, suspended in 0.5 ml of polyethylene glycol 200 + 0.5 ml of saline) and with the vehicle alone administered intraperitoneally (1 ml) 45 min before the challenge. Oxatomide reduced the number of coughs during the 3 min of challenge, lengthened the time of onset and reduced the number of coughs after cessation of the challenge significantly and a linear dose-effect regression was observed.

Animals↗

PubMed1989

Identification of subpopulations of bronchitic patients for suitable therapy by a dynamic rheological test.

The rheological properties of bronchial mucus samples, collected from randomly selected patients with chronic bronchitis by protected expectoration, under steady-state conditions without any exacerbation, were investigated in a double-blind multicentre study before and after five days of treatment with 4.5 g/day carbocysteine or with glucose as a placebo. Viscous and elastic properties of the mucus were measured with a rheometer fitted with coaxial cylinders set up in an oscillating instead of a rotating mode. The shapes of the ellipses obtained characterized the rheological properties of each bronchial mucus sample before and after treatment. Two different rheological patterns were observed. In the group of patients with initial viscosity greater than or equal to 10,000 mPa.s-1, carbocysteine treatment reduced viscosity and elasticity more than those of the placebo-treated patients. In the group of patients with viscosity lower than 10,000 mPa.s-1, the rheological modifications were the same for both groups. These results are discussed in terms of both the efficacy of carbocysteine and the necessity of rheological characterization of the patients before treatment into different groups, according to the rheological properties of their secretions, for better and targetted therapy with mucus modifying drugs.

Adult↗

PubMed1988

Clinical trials with the new antitussive levodropropizine in adult bronchitic patients.

The results of 6 clinical trials involving a total of 174 patients are reported. Levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526) was compared in double-blind manner with placebo, morclofone and cloperastine. The antitussive activity and therapeutic efficacy of the drug were shown to be greater than those of placebo and morclofone and similar to those of cloperastine. Levodropropizine was effective in about 80% of patients; in responders, cough frequency was reduced by an average of 33-51%. Levodropropizine was generally well tolerated and mild side-effects were reported for only 3% of patients.

Adolescent↗

PubMed1988

Antitussive activity and respiratory system effects of levodropropizine in man.

Antitussive activity of the new antitussive drug, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in healthy volunteers by the classical method of citric acid-induced coughing. Levodropropizine dose-dependently reduced cough frequency. Maximal inhibition was observed at 6 h after administration. Cough intensity was also reduced, as shown by the analysis of cough noise. Levodropropizine, at the dosage of 60 mg t.i.d., had no adverse effects on respiratory function nor on airway clearance mechanisms: in fact, it did not affect spirometric parameters. Levodropropizine had no effects on the rheological properties of mucus nor on ciliary activity of airway epithelium.

Adult↗

PubMed1987

Review on sobrerol as a muco-modifying drug: experimental data and clinical findings in hypersecretory bronchopulmonary diseases.

Sobrerol is an agent with a terpenic structure used to modify mucus characteristics in patients with hypersecretory bronchopulmonary diseases and this review is aimed at listing and discussing all the scientific evidence on this drug. All the toxicological findings testify its excellent tolerability and very low toxicity. In the pharmacological section of the review the effects of sobrerol on mucus production and its characteristics are discussed together with its effect on experimental models. A number of open clinical trials suggesting a therapeutic potential activity of the drug is examined together with a series of randomized double-blind clinical trials confirming its efficacy in relieving obstructive symptoms in chronic bronchitic patients.

Animals↗

PubMed1987

Rheological modifications of mucus in chronic bronchitic patients after treatment with stepronine-lysine salt.

To investigate the characteristics of bronchial mucus in bronchopneumopathic patients before and after stepronine-lysine salt treatment, a rheological double-blind randomised study has been performed. The assessment of the rheological behaviour of bronchial secretions was performed using a coaxial cylinder rheometer set up for dynamic test with sinusoidal oscillation. While the placebo group did not show significant modifications in the viscosity and elasticity parameters, in the stepronine group a significant viscosity reduction was found.

Adult↗

PubMed1986

Simple and precise method for counting ciliary beats directly from the TV monitor screen.

The modern optical microscopic technique together with the use of the small perfusion chamber allows the maintenance and observation of isolated ciliated epithelia for many hours in vitro. Counting ciliary beats is a good means for evaluating the behavior of these cells immediately under different environmental conditions and also for evaluating the pharmacologic or toxic action of drugs. Using a TV camera joined to a microscope equipped with the Nomarsky differential interference contrast set, it is possible to see on a TV monitor an image of the cilia at a very high magnification (over 1000 X), with a good resolution. This paper describes a method and an instrument, with a digital readout purposely designed to receive and count signals from a phototransistor placed directly on the protective screen of the TV monitor to correspond exactly with the point of passage of the coming and going movement of the selected cilia. In this way, it is possible to obtain (in real time and in a simple way through visual observation of the beat) the final count, which consists of the number of passages, in a prefixed time, in front of the phototransistors of the dark area which represents the ciliary body on the light background.

Cilia↗

PubMed1986

A method for maintaining, in vitro, TV-monitoring and counting ciliary beat frequency of samples from human ciliated respiratory epithelium brushing.

"Mucociliary clearance", from a clinical point of view, is one of the most important defense mechanisms of the respiratory mucosa. Clinicians, pneumologists and pharmacologists are greatly interested in methods investigating the cilia, considered the biological engine that continuously moves the physiological and/or pathological bronchial mucous secretions. This paper describes a method for the study of ciliary activity in man. By a simple brushing technique it is possible to obtain samples of ciliated respiratory epithelium, and the ciliary beat can be observed immediately by microscopy (Nomarsky differential interference contrast) in a small thermostatic perfusion chamber. The ciliary image is visualized on a TV monitor by means of a TV camera. Using a new type of digital counter with a phototransistor probe, the beat rate of a single cilium can be measured directly by the monitor screen under physiological or pathological conditions or under drug perfusion.

Bronchi↗