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Biomedical subjects

L Negri

Publications and source records attributed to L Negri.

At least 109 records · Page 6Linked to original sources
PubMed1982

[Changes in salivary immunoglobulin levels after cryosurgery of benign and malignant lesions of the oral cavity].

The authors have evaluated variations in salivary IgA, IgG, IgM levels after cryosurgical treatment of benign and malignant oral lesions. Salivary immunoglobulin levels were measured by radial immunodiffusion before a single cryotreatment 7 and 14 days after. Seven days after cryosurgery of the lesions, there was a statistically significant increase in salivary IgG and IgM levels (p less than 0,02). These results suggest that, at the time of maximal oral cavity inflammation, 7 days after cryotreatment, there was a transudation of these immunoglobulins from serum into saliva. Salivary IgA levels decrease in a significant way (p less than 0,02) on the 14th day; this behaviour seems to be strictly connected with tumor regression after cryosurgery.

Adult↗
PubMed1982

Potent in vivo and in vitro prolactin inhibiting activity of sauvagine, a frog skin peptide.

The effect of sauvagine (SAU), a frog skin peptide, on prolactin (PRL) levels was studied in vivo and in vitro. Subcutaneous administration of SAU (20 micrograms/kg) reduced plasma PRL levels in normal adult male rats and suppressed the suckling-induced rise of PRL in lactating rats even at doses of 1 and 5 micrograms/kg. Perfusion of isolated and dispersed rat pituitary cells in vitro with increasing doses of SAU (from 5 x 10(-10) to 1.7 x 10(-8)M) induced a significant dose-related decrease of PRL secretion in the eluate. These results indicate that SAU is a potent PRL inhibiting factor and that its action is exerted at the pituitary level. If SAU or a SAU-related peptide is present in the mammalian brain, it can be tentatively hypothesized that this peptide plays an important role in the control of PRL secretion.

Amphibian Proteins↗
PubMed1982

Sauvagine-like immunoreactivity in the bony fish urophysis and caudal neurosecretory system.

Immunoperoxidase methods were used to reveal Sauvagine-Like immunoreactivity (SVLI) in the urophysis and whole caudal neurosecretory system of fresh water fish Tinca tinca and Salmo gairdneri L. Both Dahlgren cell cytoplasm and axons, which reach the urophysis, were filled with SVLI granules. The urophysis shows: a) in the medullary zone, several SVLI Dahlgren cells and a thick network of SVLI axons; b) in the cortical zone, a series of complicated neurohemal knots where SVLI axonal endings surround and penetrate the capillary and glial cell networks. An individual variability and the possibility of a release of SVLI material into the cerebrospinal fluid were also demonstrated. These observations further suggest that, besides the biological effects, sauvagine and the urophysial substance urotensin I, may also have a similar structure.

Amphibian Proteins↗
PubMed1981

[Variations of serum BuChe activity during C M F therapy].

As the Authors and Others have already demonstrated, cyclophosphamide leads to a rapid and prolonged decrease in the serum cholinesterase activity. In this work, the behaviour of the serum cholinesterase in patients subjected to C M F polychemotherapy (CTX, VCR, FU) has been studied. The grouping of patients on the basis of serum cholinesterase values before treatment has demonstrated that the enzymatic activity decrease arrives at level practically homogeneous. A month after interruption of therapy values equal to those at starting point have been observed.

Breast Neoplasms↗
PubMed1981

[Clinical and functional effects of domiodol and sobrerol in hypersecretory bronchopneumonias].

A double-blind study has been carried out in adult patients suffering from acute and chronic bronchitis, and acute exacerbation of chronic hypersecretory bronchitis, excluding the bronchorreic forms, in order to evaluate the mucolytic activity of orally given domiodol and sobrerol. Treatment with both drugs resulted in an improvement in the subjective measures of ease of expectoration, severity of coughing and sputum consistency; however, there was no improvement in respiratory functions. Moreover, domiodol resulted in a significant increase in sputum volumes, since the very first days of treatment.

Adult↗
PubMed1981

[Treatment of bronchial inflammatory disorders with guacetisal].

A comparative trial conducted on 48 male and 9 female patients suitably selected in terms of indication consisted of a first stage in which a completely random, doubleblind comparison was made between acetylsalicylic acid, guacetisal and guaiacol carbonate (preparations A, B, and C) while in the second stage an association of bromexine, acetylsalicylic acid and codeine phosphate (preparation D) was examined in terms of activity and tolerance in an open trial. Statistical analysis showed the superiority of preparation B with respect to most of the parameters taken into consideration.

Acute Disease↗
PubMed1981

Action of sauvagine on the mesenteric vascular bed of the dog.

Sauvagine, a linear peptide of 40 amino acids, produced hypotension when administered intravenously to anesthetized dogs. Diastolic pressure was always more affected than systolic pressure. Aortic blood flow and venous return both increased to the same extent. The mechanism of the hypotensive response was mainly, if not exclusively, due to dilatation of the superior and inferior mesenteric arteries. Intravenous infusion of sauvagine in doses ranging from 3 to 10 ng . kg-1 . min-1 produced a dose-related increase of mesenteric blood flow up to 400% control values. Mucosal-submucosal blood flow of ileum and colon was increased, while blood flow in muscle was unaffected or slight decreased. The mesenteric vasodilator response was not prevented by adrenergic or muscarinic receptor blockade. The hypotensive response was more marked and sustained in dibenamine-propranolol treated dogs.

Amphibian Proteins↗
PubMed1981

The brain-gut-skin triangle: new peptides.

New data on tachykinins and bombesins are displayed and the present situation of research on the novel amphibian skin peptides sauvagine and dermorphin is illustrated. The potent stimulant effect of sauvagine on ACTH and beta-endorphin release has been confirmed both in vivo and on columns of isolated and dispersed rat pituitary cells, and similarly the potent inhibitory effect on PRL and GH release, both in the rat and man. Particular emphasis is laid on the occurrence of sauvagine-like immunoreactivity in fish urophysis and in amphibian nervous structures, including the retina. It is suggested that the long-searched corticotropin releasing factor and PRL release-inhibiting factor may be a sauvagine-like peptide. Dermorphin, in its turn, has been found to cause, by intracerebroventricular injection, not only analgesia and catalepsy, but also conspicuous EEG and behavioral changes in the rabbit and chick, as well as a sharp reduction in gastric emptying time and gastric acid output in the rat, together with marked stimulation of PRL release.

Adrenocorticotropic Hormone↗
PubMed1981

Radioimmunoassay of dermorphin-like peptides in mammalian and non-mammalian tissues.

A selective RIA for D-Ala2-Dermorphin (Der), a natural peptide extracted from amphibian skin, has been developed using an antibody raised in rabbits against Der which has been coupled to BSA through its phenolic hydroxyl groups of tyrosine residues with 2,4-Dichloro-6-methoxy-1,3,5-triazine. The cross-reactivity of this antibody with dermorphin analogs, C- and N-terminal fragments of dermorphin molecule, some opioid and gastrointestinal peptides was tested. Der-like immunoreactivity has been identified in tissue extracts of rats, frog and cephalopoda. Der-like peptides were purified by passing methanol extracts of the tissues through a Sephadex G25 column (16 x 100 cm) eluted with 0.1 M acetic acid at 4 degrees C. Der-like immunoreactivity from neural tissue of Dosidicus gigas, Eledone moscata, and rat brain showed a good agreement with an authentic sample of synthetic dermorphin.

Animals↗
PubMed1980

Sauvagine, a new polypeptide from Phyllomedusa sauvagei skin. Occurrence in various Phyllomedusa species and pharmacological actions on rat blood pressure and diuresis.

1. The occurrence of sauvagine, a new polypeptide from amphibian skin, and its actions on rat blood pressure and diuresis were studied. 2. Sauvagine was found to be present in the skin of all the 10 Phyllomedusa species so far studied, amounts ranging from a few micrograms to 240 micrograms per g fresh skin. 3. The polypeptide displayed in the rat an intense, long-lasting hypotensive action accompanied by tachycardia. Hypotension was not modified by either atropine or propranolol, excluding the participation of the autonomic nervous system in its production. Tachycardia, on the contrary, was partially inhibited by propranolol. 4. Hypotension is probably the main cause of the intense antidiuresis seen in hydrated rats following sauvagine administration. Reduction in urina volume was accompanied by a decrease in GFR and an increase in tubular NA+ reabsorption.

Amphibian Proteins↗
PubMed1979

Occurrence and polymorphism of bombesin-like peptides in the gastrointestinal tract of birds and mammals.

The gastrointestinal tract of mammals and birds, especially stomach and upper small intestine, contains bombesin-like peptides. This has been unequivocally demonstrated by radioimmunoassay and bioassay. Concentrations of bombesin-like activity may range from a few ng to 500-600 ng per g fresh tissue. Last values refer to the chicken proventriculus, which has been the object of a more thorough investigation. The bombesin-like peptide of the chicken proventriculus showed a marked heterogeneity. All forms probably stem from a pro-bombesin, a large precursor molecule which is insoluble in methanol, acetone, and even boiling water, but may be cleaved by acid hydrolysis. Methanol extracts contain at least two forms of the bombesin-like peptide; HCl extracts at least three forms; HCl extracts of the residue of methanol extraction at least four forms. Whereas some forms--for example, the methanol extractable forms--probably pre-exist in the tissue, other forms may be artefacts arising from acid treatment. The various forms may be distinguished from each other not only by their elution profile, but also by bioassay. In fact, though all forms show the activity spectrum characteristic for the amphibian bombesin-like peptides, they present considerable quantitative differences in activity. Pro-bombesin(s) probably occur also in the rat and guinea-pig stomach; similarly, a clear-cut heterogeneity is appreciable for the bombesin-like peptide of the human gastric mucosa.

Animals↗