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Biomedical subjects

A Martinelli

Publications and source records attributed to A Martinelli.

69 records · Page 4Linked to original sources
PubMed1977

[Accidental hypothermia in man].

Accidental hypothermia, in contrast to medical hibernation, corresponds to a sudden, unforeseen lowering of the body temperature below 35 degrees C. This may occur endogenously in association with various diseases. On the other hand, it may be due to the exogenous influences of very low environmental temperatures. An impressive observation of accidental hypothermia is described and the pathophysiological findings in accidental hypothermia are reviewed.

Accidents↗
PubMed1977

Molecular orbital studies on the mechanism of drug-receptor interaction. 2. beta-Adrenergic drugs. An approach to explain the role of the aromatic moiety.

The role of the aromatic moiety of beta-adrenergic drugs in the interaction with the receptor was investigated using the quantum mechanical ab initio SCF-MO-LCAO method. The structure-activity relationship was essentially discussed by analyzing the electrostatic molecular potential of three compounds which constitute meaningful portions of isoproterenol, INPEA, and doberol, the first drug having a stimulating activity and the others a blocking one. The results obtained point out the different roles played in the drug-receptor interaction by the various regions of the drugs and they also show that the aromatic moiety influences both the affinity and the intrinsic activity of the drugs. Indeed, the spatial correspondence among zones with negative potentials, which are localized on the phenyl substitutents of isoproterenol and INPEA and on the phenyl ring of doberol, could contribute to the affinity. On the other hand, the intrinsic activity of isoproterenol might be associated both with the proton-donor tendency of one phenolic OH group and with the wide zone of negative potential which spreads on a large part of the aromati moiety.

Ethanolamines↗
PubMed1975

A multicenter double blind clinical trial on 3.4.5-trimethoxybenzoiyl-epsilon-aminocaproic acid (C-3) in acute myocardial infarction.

186 out of 391 patients with acute myocardial infarction were treated with C-3 and 205 with placebo in a multicenter, double-blind clinical trial. Ensuing complications were treated in the same way in both groups. C-3 was injected i.v. slowly at the dose of 2 g statim plus 6 g by continuous drip infusion over 24 hrs for 5 days. During treatment, clinical progress was influenced only in regard to cardiac failure since in the C-3 group the improvement was more significant than in the placebo one (P less than 0.0025). Mortality rates were 8.1% and 11.2% for the C-3 and placebo groups, respectively. The difference in mortality was significant (P less than 0.05) for patients treated with C-3 for more than 24 hours. Mortality in male patients treated with C-3 for more than 12 hours was significantly lower (P less than 0.025). In patients less than 60 years old mortality rate was significantly lower (P less than 0.05) and was more so in patients receiving C-3 for more than 12 hours (P less than 0.025). Mortality due to complications was lower in the C-3 group, with arrhythmias (9.8% vs 14.2%), cardiogenic shock (69.2% vs 75%), and cardiac failure (9% vs 19.4%). Results agree with the hypothesis that C-3 may be effective in acute myocardial infarction by improving the action of traditional antiarrhythmic drugs, and augmenting myocardial contraction energy.

Acute Disease↗
PubMedDate not supplied

Toward the rational development of peptidomimetic analogs of the C-terminal endothelin hexapeptide: development of a theoretical model.

In an early report on the structure-activity relationship of endothelin (ET) peptides, it was reported that the C-terminal hexapeptide ET(16-21), His-Leu-Asp-Ile-Ile-Trp, is the minimum ET fragment which maintains biological activity in some, but not all the tissues responding to ETs. Subsequently, other authors described a series of analogs of this peptide, in which the His 16 residue was replaced by non-natural amino acids, characterized by bulky aromatic side chains. Among them, two well-characterized non-selective ETA/ETB antagonists were PD 142893 and PD 145065; interest in these potent ET antagonists was, however, reduced by their peptidic structure which was likely to lead to undesirable properties such as poor bioavailability and short duration of action. On the basis of these premises, our previous studies led to the development of a peptidomimetic ligand of ET receptors (compound 3), based on the replacement of the His 16 residue of ET(16-21) with an (E)-N-(benzyloxy)iminoacyl moiety; compound 3 proved to possess a certain affinity for ET receptors, albeit lower than that shown by PD 142893 and PD 145065. We report here on ETA/ETB binding affinity of compounds 4-12, designed as a new series of ET(16-21) analogs. Compounds 4 and 5 were practically devoid of any affinity; derivatives 6-12 exhibited appreciable affinity indices for ETB receptors higher than that shown by 3, even if still lower than that obtained for PD 145065. This paper also describes the development of a pharmacophoric model able to explain the ET receptor binding properties of our hexapeptide analogs compared with those of PD 142893 and PD 145065 and IRL2500, recently reported as a potent ETB selective endothelin antagonist.

Amino Acid Sequence↗
PubMedDate not supplied

Predictors of participation in a smoking cessation intervention group among low-income women.

The predictors of participation in a smoking cessation group among low-income women were examined. Fifty smokers were recruited from a Midwestern community primary care setting serving an uninsured, underinsured, and Medicaid population. Participants completed a questionnaire before the intervention, and eleven women chose to participate in the 6-week sessions. There were few differences between the control group (nonparticipants) and the intervention group. The intervention group had significantly higher intention-to-quit scores. Logistic regression analysis was used to predict group membership with age, self-efficacy, optimism, social support, nicotine dependence, intention-to-quit, and other smokers in the home as the predictor variables. The only two significant predictors of participation in the cessation intervention were self-efficacy and intention-to-quit smoking. The higher the intention-to-quit score and the lower the self-efficacy score (the belief that one can be successful in not smoking); the more likely these women were to participate in the group intervention. Results are discussed in terms of their clinical relevance as well as future research in the area.

Adult↗
PubMedDate not supplied

A new regimen of cisplatin, epirubicin and methotrexate (PEM-3) as primary chemotherapy for locally advanced bladder cancer.

In this phase II study, 41 patients with locally advanced urothelial bladder cancer (T2-4, N0, M0) were treated with primary chemotherapy (cisplatin, epirubicin, methotrexate: PEM-3). All the patients were assessable for response and toxicity. Clinical monitoring was performed with computerized tomography and cystoscopy. Nineteen clinical complete remissions (46%) and 10 partial remissions (24.5%) were obtained (CR + PR, 70.5%; 95% confidence interval, 57%-85%). Ten patients were considered to have clinically stable disease (24.5%), and 2 patients progressed (5%). Surgery after chemotherapy was performed in 22 cases: in 6 patients (27%) a pathologic complete response was achieved. The pathologic stage was lower than the initial clinical stage in 13 patients (59%). After a median follow-up of 3 years (range, 1-4), the median time to progression was 104 weeks. At this writing, 20 patients, 12 of which were submitted to surgery and 8 were not operated, are disease-free. The 3-year survival rate is 52%. No one had to interrupt the treatment because of toxicity. In conclusion, the PEM-3 regimen is a very active and well-tolerated regimen in locally advanced bladder cancer.

Aged↗
PubMedDate not supplied

Quantitation of HCV RNA in liver of patients with chronic hepatitis C.

BACKGROUND/AIMS: Liver HCV RNA has been quantitated in few studies and the feasibility and the role of this parameter in the evaluation of patients with chronic HCV hepatitis still warrant study. Our aim was to determine the concentrations of HCV RNA in the liver of chronic HCV patients and to correlate the results with serum viral load. We also studied the relation of levels of HCV RNA in the liver with serum aminotransferases levels and with the presence of cirrhosis. METHODS: Twenty patients (14 males, aged 28 to 61 years) were studied. Twelve were infected by HCV type 1, six by type 3 and one by type 5. Percutaneous liver biopsy samples were obtained from 14 patients, and the remainder from liver explant in patients undergoing OLT. Twelve had chronic hepatitis and eight cirrhosis. HCV RNA levels were determined by bDNA. RESULTS: HCV RNA levels below the detection limit were found in one liver and in five serum samples. HCV RNA (mean +/- SD) was 2.1 x 10(8) +/- 2.2 x 10(8) Eq/gm in the liver and 94 x 10(5) +/- 93 x 10(5) Eq/mL in serum, with a significant correlation between these values (r = 0.89; P < 0.0001). Serum HCV RNA levels were significantly lower (P = 0.001) in cirrhotic than in chronic hepatitis patients, while the groups did not differ in liver HCV RNA levels. No correlation was observed between liver or serum HCV RNA and serum ALT or AST. CONCLUSIONS: Quantitation of HCV RNA is possible even in small liver samples. Although average levels are more than one log higher than those observed in serum, hepatic concentrations correlate with those observed in serum. The application of this technology to monitoring antiviral therapy and understanding the pathogenesis of the disease remains to be determined.

Adult↗
PubMedDate not supplied

Synthesis and beta-adrenergic activity of a series of 3-(substituted-benzylideneaminoxy)propanolamine derivatives.

In an attempt to change the beta-adrenergic properties of completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives, from antagonist to agonist, while still retaining the beta 2-selectivity, we described, in a previous paper, the synthesis of a series of such derivatives possessing a hydroxy or methoxy group linked to the aliphatic substituent present on the oximic carbon. However, pharmacological tests indicated that these compounds maintain the competitive antagonism on beta receptors. In this paper, the synthesis and the results of functional tests on isolated preparations are reported for a new series of 3-(substituted-benzylideneaminoxy)propanolamine derivatives in which either the hydroxy or the methoxy group is linked to a phenyl ring present on the oximic carbon. The results obtained are then discussed, taking into account the conformational and reactivity properties of these compounds, determined by means of theoretical calculations.

Adrenergic beta-1 Receptor Agonists↗