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Biomedical subjects

C Grieco

Publications and source records attributed to C Grieco.

At least 19 recordsLinked to original sources
PubMed1990

[The prognostic assessment of dental reimplantations and autotransplants. Clinico-statistical studies].

The identification of prognostic factors which influence the long-term results of dental retransplantation and autotransplantation is one of the main aims of clinical research whose principal scope is remove or alter those factors which have a negative influence on outcome, and to identify the causes of failure and areas for improvement. The paper reports the most significant results of a clinical survey which was carried out on 135 patients who had undergone retransplantation and/or autotransplantation and were then followed for 8 years.

Follow-Up Studies↗
PubMed1980

QSAR in a series of muscarinic agents. Note II - Pyridine and furan derivatives.

Two sets of substantial picolyl and furfuryltrimethylammonium salts have been synthesized and their affinities (expressed as pD2) have been studied with the aim of characterizing muscarinic receptor spaces to which the ligand structural features bind. The new data were combined with those relative to a set of substituted benzyltrimethylammonium salts previously studied to formulate an overall QSAR which showed that the pD2 value is strongly dependent on hydrophobic and steric parameters of the ring substituent. Moreover, two indicator variables were considered to take into account the extra-activity associated with special structural features of the heterocyclic system and the further increase in activity associated with a "cooperative interaction" between the lipophilic binding of the substituent and a polar interaction of the ring heteroatom. The results confirm our earlier predictions and offer a model for ligand binding which gives a consistent view of the topology of the ligand attachment points on the receptor.

Animals↗
PubMed1979

QSAR in a series of muscarinic agents.

The results of a pharmacological investigation on a series of 3-substituted benzyltrimethylammonium salts possessing muscarinic activity are reported. Correlative analysis shows that the pharmacodynamic activity is a function of the hydrophobic-lipophilic and steric parameters associated with the substituents. In particular, it is revealed that a lipophilic pocket of limited size is present in the muscarinic receptor at an optimal distance from the electron--rich site with which the cationic termination interacts.

Animals↗
PubMed1979

Physicochemical parameters in biological correlation analysis: meaning and limits.

Correlation analysis assumes that the physicochemical factors governing the transport, metabolism and drug-receptor interaction can be factored into hydrophobic-lipophilic component, polarizability and dispersion forces, electronic and steric effects and into indeterminate factors. Using computerized regression analysis, a generalized equation can be formulated to correlate the biological response of a set of compounds with their chemical structures in terms of physicochemical parameters of substituents. In order to explore the scope of each defined physicochemical parameter, correlations between biological effects and some combination of substituent indices are discussed.

Chemical Phenomena↗
PubMed1978

[Correlative analysis in the study of enzyme-ligand interactions].

A comprehensive study on enzyme ligand interactions by QSAR techniques is discussed. Thirteen correlation equations are presented which relate activity of 1086 ligands of isolated chloroplasts, chymotrypsin, dihydrofolate reductase, xanthine oxidase and guanine deaminase to their chemical structures. Two kinds of space within and on the surface of an enzyme are defined by means of pi and MR constants. Emphasis is put on the use of indicator variables as a means of rationalizing special enzyme-ligand interactions. The use of such studies for drug development is discussed.

Chloroplasts↗
PubMed1977

Quantitative structure-activity relationship of chymotrypsin-ligand interactions.

Quantitative structure-activity relationships (QSAR) have been formulated for the interactions of a variety of ligands with chymotrypsin. The parameters Km, k2, k3, kcat, and Ki are found to be strongly dependent on molar refractivity as well as steric and electronic character of the substituents in structures of the type R2CH(COOR3)NHCOR1 where R may be H. A model for binding of D and L esters is presented which gives a consistent view of the binding step, acylation, and deacylation. The model suggests new avenue for exploration.

Acylation↗
PubMed1977

Structure-activity correlations for antibacterial 1,5-benzodiazepine derivatives on gram-positive cells.

The antibacterial activity of a set of 1,5-benzodiazepine derivatives against Staph, aureus and Strep, pyogenes has been correlated with structural features of the compounds examined. It is shown by means of substituent constants and regression analysis that the lipophilic character of the molecule is the most important factor in determining its activity. Electronic and steric effects appear to be quite important.

Benzodiazepines↗
PubMed1976

[Correlative analysis of chemical structure - biological activity using Hansch's method: principles and development of the method].

The basic principles and developments on which the Hansch multiple parameter approach depends are described. A correlation analysis on the antibacterial activity of 2-Y-4-(X-phenyl)-3H-1,5-benzodiazepines is discussed. The use of indicator varioables is shown to greatly increase one's ability to formulate quantitative structure-activity relationships. This approach allows one to carry out objective studies of massive amounts of chemical and biological data.

Bacteria↗
PubMed1976

[Retrospective analysis of drug projection using correlative technics].

The problem of choosing substituents to allow correct correlative analysis according to the "Hausch Approach" is discussed. The problem of colinearity among parameters is considered in a case study on 296 anilides which inhibit the Hill reaction. The difficulty in of determining whether, pi or MR is the important variable in changes in activity is shown. "Cluster analysis" is discussed and proposed as a rational method for the selection of substituents to be introduced into biologically active structure in order to explore the scope of each defined physico-chemical parameter. An example of the use of this method conerning auxin activity of 1- and 2-benzotriazole derivatives is given.

Anilides↗