1,721,027 research outputs found
Homeopathy and placebo RID C-3728-2011
No full textThe foundation of homeopathic medicine is the 'Similia Principle', also known as the 'Principle of Similarity' or also as the 'Simile', which reflects the inversion of pharmacological effects in healthy subjects as compared with sick ones. This article describes the inversion of effects, a widespread medical phenomenon, through three possible mechanisms: non-linearity of dose-response relationship, different initial pathophysiological states of the organism, and pharmacodynamics of body response to the medicine. Based on the systemic networks which play an important role in response to stress, a unitary and general model is designed: homeopathic medicines could interact with sensitive (primed) regulation systems through complex information, which simulate the disorders of natural disease. Reorganization of regulation systems, through a coherent response to the medicine, could pave the way to the healing of the cellular, tissue and neuro-immuno-endocrine homeodynamics. Preliminary evidence is suggesting that even ultra-low doses and high-dilutions of drugs may incorporate structural or frequency information and interact with chaotic dynamics and physical-electromagnetic levels of regulation. From the clinical standpoint, the 'simile' can be regarded as a heuristic principle, according to which the detailed knowledge of pathogenic effects of drugs, associated with careful analysis of signs and symptoms of the ill subject, could assist in identifying homeopathic remedies with high grade of specificity for the individual case
CONFORMATIONAL-CHANGES IN PANTETHEINE HYDROLASE AS A FUNCTION OF GUANIDININM CHLORIDE CONCENTRATION
No full textThe denaturation of pantetheinase (pantetheine hydrolase, EC 3.5.1.-) was followed in guanidinium chloride using tyrosyl and tryptophanyl residues as probes in connection with change in enzymatic activity. Movements of tryptophanyl and tyrosyl residues during denaturation were studied by second-derivative and fluorescence spectroscopy and the number of these amino acids present in the protein was calculated from spectroscopic data. Pantetheinase shows a very high resistance to denaturation, being completely unfolded at guanidinium chloride concentration higher than 6.5 M. Monitoring enzymatic activity shows that inactivation of the enzyme occurred before noticeable conformational changes were detected and it is suggested that the conformation of the active site is flexible and easily perturbable compared to the protein as a whole. This inactivation is reversible, as shown by renaturation experiments. Second-derivative and fluorescence spectra showed also that tyrosyl and tryptophanyl residues are largely exposed in the native protein, confirming its hydrophobic behavior
Il Rispetto della Legge
No full textAnalisi della legge Regionale Abruzzese in materia di Protezione Civil
Circadian temperature rhythm in intact, sham operated, gonadectomized rats.
No full textThirty-six CS rats (18 females and 18 males) have been studied: 22 gonadectomized (11 males and 11 females), 6 sham operated (3 males and 3 females) and 8 intact rats (4 males and 4 females). Three series of rectal temperature measurements have been performed: in the first one the animals were housed under strictly usual environment conditions (as far as the housing and lighting regimen was concerned); in the second one the animals were housed in metabolic cages in LD 12:12; in the third one the animals were housed in metabolic cages in DD. The mesor of temperature rhythm was always lower in ovariectomized than in intact rats, and always higher in castrated than in intact rats. Z9
Is pantetheinase the actual identity of mouse and human vanin-1 proteins?
No full textPantetheinase is an amidohydrolase involved in the dissimilative pathway of CoA, allowing the turnover of the pantothenate moiety. We have determined the N-terminal sequence as well as the sequences of a number of tryptic and chymotryptic peptides of the protein isolated from pig kidney. These sequence stretches were used as probes to search in the SwissProt database and significant similarities were found with a GPI-anchored protein (mouse vanin-1, with a suggested role in lymphocyte migration), with two putative proteins encoded by human cDNAs (VNN1 and VNN2) and with human biotinidase. On the basis of sequence similarity, we propose that vanin-1 and VNN1 should be identified as pantetheinase
A KINETIC-STUDY ON PANTETHEINASE INHIBITION BY DISULFIDES
No full textThe mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Dupre, S. & Cavallini, D. (1986) Biochim Biophys. Acta 870, 82-92]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site
Ricin and Saporin: Plant Enzymes for the Research and the Clinics
No full textMany plants produce enzymes with N-glycosidase activity, also known as Ribosome Inactivating Proteins.
These proteins remove a specific adenine residue from the ribosomal RNA (28S in eukaryotes) inducing the block of protein
synthesis by inhibiting the binding of the Elongation Factor 2. Both eukaryotic and prokaryotic ribosomes (with different
sensitivity) can irreversibly be damaged by the action of these enzymes, suggesting their use as cytotoxic drugs. In
fact several applications of targeted N-glycosidases have been developed (i.e. immunotoxins) for the treatment of human
diseases such as leukaemia, but biotechnological development has furthermore suggested new applications of targeted Nglycosidases
(i.e. Ig192-saporin) that are now used as powerful tools for cell biology research. The high number of enzymes
available and the possibility to express these proteins as recombinant products, allow to predict new formulations
and applications discussed in this paper starting from the example of the model toxins ricin and saporin
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