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Biomedical subjects

G Toma

Publications and source records attributed to G Toma.

15 recordsLinked to original sources
PubMed2005

Prolonged gemcitabine infusion in advanced non-small-cell lung cancer with stable disease after gemcitabine 30-min infusion.

BACKGROUND: Although 30-min gemcitabine infusion has become the standard administration, pre-clinical and clinical studies have suggested the possibility that an infusion rate of 10 mg/m(2) per minute may be more effective. The main objective of this study was to investigate whether the pursuance of gemcitabine, administered at a prolonged infusion rate, was able to convert stable disease to objective response after two or three cycle of standard administration. The secondary end-point was the evaluation of the new schedule toxicity. PATIENTS AND METHODS: Thirty-eight patients, with stage IIIA-B and IV NSCLC already treated by two or three cycles of 30-min gemcitabine infusion, alone or in combination with cisplatin, were enrolled: 26 patients (aged <70 years) were treated with cisplatin 80 mg/m(2) on day 1 plus gemcitabine 1200 mg/m(2) over 120 min on day 1 and 8 every three weeks and 12 patients (aged > or =70 years) were treated with gemcitabine alone 1200 mg/m(2) over 120 min on day 1 and 8 every three weeks, for two courses. Simon's two stage minimax design was applied to calculate the sample size. Assuming p(0) (low conversion rate) 5%, p(1) (target conversion rate of interest) 20%, alpha error 0.05, beta error 0.10 a total of 29 evaluable patients had to be accrued during stage 1. In case at least one objective response was observed, a further nine evaluable patients had to be enrolled into the study during stage 2. The regimen was considered promising if > or =4 objective responses out of 38 evaluable patients were observed. RESULTS: Thirty-eight patients were evaluable for response and in five patients (with stable disease after two courses of gemcitabine 30' infusion) a partial response was observed (conversion rate 13.1%, 95% confidence interval 4.4-28%). Toxicities were more frequently observed with cisplatin plus 120-min gemcitabine infusion: grade 3-4 neutropenia, thrombocytopenia and anaemia in 28, 22 and 16% of the courses, respectively. CONCLUSIONS: The prolongation of gemcitabine infusion time is able to convert stable disease to partial response in 13% of the cases. The haematological toxicity seems enhanced with cisplatin plus gemcitabine prolonged infusion.

Aged↗
PubMed2005

Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

Journal Article↗
PubMed1994

Uromodulin (Tamm-Horsfall protein) is a leukocyte adhesion molecule.

Uromodulin (Tamm-Horsfall protein), the most abundant constituent of human urine, is synthesized exclusively in the kidney tubular epithelium and its amino acid sequence suggests a capacity for cell adhesion. We investigated adhesion between human uromodulin and neutrophils by allowing uromodulin, immobilized on microtiter plates, to interact with neutrophils. It was found that neutrophils attached to uromodulin in a saturable manner. The binding was inhibited by uromodulin in solution. It required metabolically active cells, was calcium sensitive and could be inhibited by arginine-glycine- aspartate-containing peptides in solution. These data suggest that uromodoulin can act as a specific ligand for neutrophils. This interaction is potentially important in leukocyte trafficking in the kidney and in the pathogenesis of interstitial nephritis.

Amino Acid Sequence↗
PubMed1984

Specific IgE antibodies in twenty-eight workers with diisocyanate-induced bronchial asthma.

A specific IgE-mediated response was evaluated in twenty-eight workers exposed to TDI or MDI, with diagnosis of occupational asthma and positive to bronchial provocative challenge. The presence of anti-diisocyanate IgE was observed in 27% of subjects exposed to TDI and 83% of those exposed to MDI, particularly in individuals who experienced an acute massive exposure. An immediate-type response to bronchial provocative test was found in 66% of individuals with specific antibodies. Specific IgE are prevalent (91%) in subjects who developed symptoms before 6 years of exposure to isocyanates. The results suggest an association between the presence of specific IgE, early asthmatic symptoms and heavy episodic exposure.

Asthma↗
PubMed1984

[Role of tobacco smoking in the determination of CO diffusion impairment in silicotic patients].

Alveolar-capillary diffusion of CO was evaluated in 48 silicotics with predominantly small irregular opacities at low profusion. The mean value of CO diffusion lay between 82 and 87% of the reference values, except for DLCOSS2 which was slightly reduced (74% of theoretical). There was no correlation between the functional data and duration of work but there was a significant reduction of the CO diffusion values according to smoking, which was greatest in those smoking more than 15 pack-years. Subjects with small irregular opacities presented lower values than those with small "p" or "q" opacities, but this difference was not apparent when only non-smokers were considered.

Adult↗
PubMed1983

Absence of IgG antibodies to TDI-HSA in a radioimmunological study.

Sera of ninety-one workers with respiratory symptoms related to occupational exposure to toluene diisocyanate (TDI) were tested by a solid phase radioimmunoassay using polyvinyl plates, in an attempt to demonstrate specific IgG antibodies to a conjugate of TDI with human serum albumin (TDI-HSA). Different conjugates were prepared. In our radioimmunoassay a TDI-HSA 1600 (1600 micrograms TDI/mg HSA), obtained at alkaline pH with borate buffer, was used; this conjugate was immunologically reactive and did not contain protein macro-aggregates. No difference in percent of binding of radiolabelled anti-human IgG to TDI-HSA coated on plastic plates was found between exposed workers (asthmatic and non-asthmatic) and fifteen normal subjects. This may suggest that either TDI-induced bronchial asthma is not mediated by IgG antibodies, or TDI-HSA conjugate is unsuitable to be detected by anti-isocyanate IgG.

Animals↗
PubMed1981

Bronchial asthma due to inhaled wood dust: Tanganyika aningré.

Three cases of bronchial asthma due to wood dust from Tanganyika anigré are reported. All patients were woodworkers and had symptoms of dyspnoea, cough and wheezing, and sometimes itchiness and rhinorrhoea, after exposure to Tanganyika aningré. The intradermal skin tests were positive for antigenic extract of Tanganyika aningré. In two patients the bronchial provocation test with the wood dust and with the soluble extract inhaled by aerosol was positive showing an immediate reaction; in the same patients bronchial hyperreactivity was also found. Atopy was present in one subject. No precipitins or specific IgE were found in patient sera by the immunodiffusion technique or by RAST.

Adult↗
PubMed1981

A study of short-term effect of rehabilitative therapy in chronic obstructive pulmonary disease.

51 male patients with mild degree chronic airway obstruction underwent detailed evaluation of pulmonary function tests, blood gas analysis and exercise tolerance test before and after a short-term therapy. The patients were randomly assigned to medical therapy alone or to medical and rehabilitative therapy. 23 patients treated with medical and rehabilitative therapy showed a significant decrease of respiratory rate and PaCO2 and a significant increase of TV, FEV 1.0, FEV 0.75 x 40, PaO2, SaO2 and exercise tolerance after a month of therapy. 28 patients treated with medical therapy alone showed a significant increase of VC and FEV 0.75 x 40. These data suggest that rehabilitative therapy is a valid adjunct to medical therapy in the short-term treatment of chronic airway obstruction.

Blood Gas Analysis↗
PubMed1979

Bronchial asthma and dermatitis due to spiramycin in a chick breeder.

A case of bronchial asthma and dermatitis due to spiramycin is described in a non-atopic woman who worked as a chick breeder and handling poultry feed containing antibiotic or chemoterapic drugs including spiramycin, chlortetracycline and sulfadimethoxine. Patch tests showed a vigorous delayed reaction to spiramycin. Inhalation challenge test with the chick feed containing spiramycin reproduced symptoms of late asthmatic response (FEV1 fell by 14% and FEF25-75 by 25% within the 4th and 6th hour) with leucocytosis. No significant modification of FEV1 and FEF25-75 was observed within 24 hours after challenge with chick feeds containing other antibiotic or chemotherapeutic agents but not spiramycin. On leaving her job, the patient had no further skin reactions or bronchial asthma episodes. This case suggests that allergic reactions to a chemical product may involve both type III and IV hypersensitivity.

Adult↗
PubMedDate not supplied

[Exposure to lead in workers in highway toll booths].

200 workers of the pay-toll stations of a Tuscan motorway were examined for PbB, FEP and urinary delta-ALA. The mean value of PbB was 37 +/- mcg/100 ml R.B.C., but in 39 subjects (19.4%) it was over 50 mcg/100 ml R.B.C. FEP showed a mean value of 23.3 +/- 8.9 mcg/100 ml and in 8 subjects (4.4%) it exceeded 40 mcg/100 ml. Urinary delta-ALA was always in the normal range. There was a light difference in the mean value of PbB in comparison with a group of 50 normal subjects; no difference was found in FEP levels. The distribution of PbB and FEP values was also studied in workers and in non exposed subjects.

Humans↗
PubMedDate not supplied

[Specific bronchostimulation tests in occupational medicine].

A review of the literature about specific bronchial provocation tests in occupational asthma was made. The Authors focus on some problems related to the methods of exposure; furthermore, in separate chapters the bissynosis and the relationship between specific and aspecific hyperresponsivity are dealt with. The Authors conclude that it is necessary a standardization of the methods for the reproducibility of the tests, and, as in aspecific hyperresponsivity, so also the specific responsivity may be quantified in dose-response curves.

Allergens↗