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Biomedical subjects

S Ferri

Publications and source records attributed to S Ferri.

At least 73 records · Page 4Linked to original sources
PubMed1993

Thyroid involvement in chronic inflammatory rheumatological disorders.

The association between rheumatological and thyroid disorders has long been known, the most common being the association of rheumatoid arthritis and autoimmune thyroiditis. Little is known as to possible thyroid involvement in other rheumatological disease of possible autoimmune aetiology, such as psoriatic arthritis and ankylosing spondylitis. We measured thyroid volume and function as well as the prevalence of anti-microsome and anti-thyroglobulin antibodies in 107 consecutive patients with rheumatoid arthritis, 42 patients with psoriatic arthritis, and 12 male patients with ankylosing spondylitis. Fifty-two normal subjects were used as controls. The average thyroid volume, measured at ultrasounds, was increased in all groups of patients, and the prevalence of thyroid enlargement (A-P diameter > 20 mm) was 2-3 fold higher in rheumatological disorders in comparison to controls. Both, patients with rheumatoid arthritis and psoriatic arthritis had higher-than-normal fT4 levels and an increased prevalence of anti-microsome antibodies. In the rheumatoid arthritis group alterations in thyroid volume and function were present irrespective of disease activity, whereas in psoriatic arthritis thyroid involvement was confined to patients with active disease. Our data are consistent with a significant thyroid involvement in rheumatological disorders, which is not limited to diseases with a definite autoimmune aetiology.

Adult↗
PubMed1993

Immunoreactive dynorphin A-like material in extracted human hypothalamic-hypophysial plasma.

Immunoreactive dynorphin A-like material (ir-dyn A) in human plasma was measured by a validated radioimmunoassay. In peripheral plasma extracts mean concentrations between 20 and 40 fmol/ml were determined in volunteers and in patients with pituitary adenomas. In this latter group superimposable levels were detected three days before and during transsphenoidal microsurgery. Interestingly, ir-dyn A levels evaluated in extracts of hypothalamic-hypophysial plasma obtained during surgery, just after tumor removal, were 4-5 times higher than in peripheral plasma. Reverse-phase high performance liquid chromatography (rp-HPLC) of extracts of peripheral plasma samples revealed two immunoreactive peaks. The major form had the same retention time of dyn A-(1-32); whereas a second, more lipophilic, peak eluted later and was not further characterized. In contrast, rp-HPLC analysis of extracts of plasma collected from the suprapituitary region displayed only one peak eluting in the position of synthetic dyn A-(1-17). The presence of dyn-related peptides in hypothalamic-hypophysial plasma supports the hypothesis that they may play a part in the regulation of hypothalamic and/or pituitary functions in humans.

Adenoma↗
PubMed1993

Polycyclic guanidine alkaloids from the marine sponge Crambe crambe and Ca++ channel blocker activity of crambescidin 816.

Four pentacyclic guanidine derivatives (crambescidin 800 [5], crambescidin 816 [6], isocrambescidin 800 [9], and crambine [10]) related to ptilomycalin A [11] have been isolated from the Mediterranean sponge Crambe crambe. Isocrambescidin 800 and crambidine are new derivatives, the structures of which have been determined on the basis of their spectral properties. The absolute configuration of crambescidin 816 at the stereogenic center C-43 has been determined by applying Mosher's method. Pharmacological and biological activities of the Crambe crambe alkaloids are reported. In particular, crambescidin 816 was found to have a potent Ca++ antagonist effect and to inhibit the acetylcholine-induced contraction of guinea pig ileum at very low concentrations.

Acetylcholine↗
PubMed1993

Scanning electron microscopy, chemical and histologic analysis in human periarthritic shoulder biopsy.

In the present study biopsies were analyzed, taken from the left shoulder of a patient who, according to the radiological diagnosis, was suffering from calcific periarthritis. In both optical and electronic microscopy the mineralogical observations showed crystalline aggregations, while the chemical analysis, carried out with an Edax EDS spectrophotometer, confirmed the presence of Ca and P in them, in the ratio typical of biological apatites. The histological observations clearly indicate a change in the metabolism of the tissues present. In the samples observed the damage to the muscular tissues is easily seen while the connective tissue, though apparently less compromised, shows the presence of numerous calcifications whose damage cannot be revealed solely through histologic observations. The authors, linking the structural histologic alterations observed to the presence of hydroxyapatite granules as well as to the patient's painful symptoms, believe all these observations are the result of a chronic process.

Adult↗
PubMed1993

Studies on the anti-phospholipase A2 and anti-inflammatory activities of a uteroglobin fragment and related peptides.

The nonapeptide antiflammin P1 (H-Met-Gln-Met-Lys-Lys-Val-Leu-Asp-Ser-OH), its isoAsp8 analogue and the corresponding aminosuccinyl peptide were prepared, characterized and tested for inhibition of phospholipase A2 (PLA2) in vitro and for anti-inflammatory activity in vivo under assay conditions recently recommended. All peptides are devoid of PLA2 inhibitory and anti-inflammatory activity.

Amino Acid Sequence↗
PubMed1992

Alterations in vasoactive intestinal polypeptide-related peptides after pentylenetetrazole-induced seizures in rat brain.

The possible involvement of vasoactive intestinal polypeptide-related peptides in pentylenetetrazol (PTZ)-induced seizures in rats was investigated. The chemoconvulsant PTZ was administered (45 mg/kg i.p.) either acutely or chronically for three days. The detailed time course of changes in VIP-(1-28) and VIP-(22-28) was examined in several rat brain areas 5 and 20 min and 24 h after acute treatment and after three days chronic treatment. Ir-VIP levels dramatically decreased in all areas 5 min after PTZ injection, remained low after 20 min and progressively increased back to control values after 24 h and after three days of repeated treatment (except for the cortex). Chromatographic analysis of extracts prepared from PTZ-treated rats revealed a concomitant decrease in VIP-(1-28) and increase in VIP-(22-28). Thus VIP-(22-28) might be a product of the internal cleavage of the precursor VIP-(1-28) after its neuronal release; alternatively, VIP-(22-28) might be generated by post-transcriptional processing of VIP-(1-28), and thus be an 'independent' neuropeptide. The results suggest that VIP-(1-28)/VIP-(22-28)-containing neurons might be involved in PTZ-induced seizures in rat brain, and that VIP-(22-28) might play a role in these experimental seizures.

Amino Acid Sequence↗
PubMed1992

Dynorphin B-like immunoreactivity in gastroduodenal biopsy specimens from gallstone patients.

Dynorphin B-like immunoreactivity (ir-dyn B) was measured by a validated radio-immunoassay in gastroduodenal biopsy specimens from control and gallstone patients. Levels were significantly lower in acetic acid extracts of specimens of the transverse portion of the duodenum from gallstone patients. Gel permeation chromatography showed that almost all ir-dyn B in duodenal samples corresponded to a molecular form co-eluting with authentic dyn B. Duodenal extracts from gallstone patients had less of this form. Reverse-phase high performance liquid chromatography of the pooled gel chromatography fractions showed up a molecular form with the same retention time as synthetic dyn B which was significantly less in fractions from duodenal extracts of gallstone patients. These results indicate the occurrence of dyn B in the human gastrointestinal tract; however, at this stage of our understanding, no causal relationship can be demonstrated with functional alterations of the biliary tree.

Adult↗
PubMed1992

Dynorphin A-(1-17) and dynorphin B are released from in vitro superfused rat hypothalami. Effects of depolarizing agents and ovariectomy.

We measured the release of immunoreactive (ir) dynorphin (dyn) A-(1-17) and dyn B from the rat hypothalamus by an in vitro superfusion technique. The system was validated on the basis of the recovery and stability of radiolabeled peptides added to the superfused hypothalami. These were detected as authentic peptides by reverse-phase high-performance liquid chromatography (rp-HPLC) only in the presence of a cocktail of peptidase inhibitors added to the superfusion medium. We observed spontaneous release of ir-dyn B, evaluated by a validated radioimmunoassay in the superfusates, that was increased by potassium and veratridine depolarization. It was calcium-dependent and tetrodotoxin-sensitive. We could not evaluate ir-dyn A-(1-17) directly in the superfusates, because the peptidase inhibitors added to the medium significantly altered the tracer-antibody reaction. To obviate this problem, pooled superfusate samples were purified on C18 cartridges and assayed by rp-HPLC. Rp-HPLC analysis of superfusates revealed two molecular forms with the same retention time as authentic dyn A-(1-17) and dyn B which were four times higher in K(+)-stimulated fractions. We could not detect dyn A-(1-32), comprising dyn A-(1-17) and dyn B, even though this peptide is recognized by the antibodies used in this study and is detected in acetic acid extracts of the rat hypothalamus. The spontaneous and K(+)-evoked release of ir-dyn A-(1-17) and ir-dyn B were significantly higher in 2-week ovariectomized rats, in parallel with the increase of their content in the anterior hypothalamus preoptic area.

Animals↗
PubMed1991

Chronic opiate agonists down-regulate prodynorphin gene expression in rat brain.

The effects of long-term administration of opioid agonists on the regulation of prodynorphin gene expression in rat brain were investigated. Chronic intracerebroventricular treatment with the synthetic opioid agonist acting on the kappa receptor, U-50,488H, and the classic mu agonist morphine markedly decreased prodynorphin mRNA levels in hypothalamus, hippocampus and striatum of tolerant rats. Levels of ir-Dynorphin A remained unchanged except in two cases. Chronic exposure to opiates thus appears to induce modifications of the endogenous opioid system, as regards gene expression regulation.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1991

Heterogeneity of immunoreactive dynorphin B-like material in human, rat, rabbit and guinea-pig heart.

Immunoreactive dynorphin B-like material (ir-dyn B) was detected in acetic acid extracts of human atrial specimens and of rat, rabbit and guinea-pig atria and ventricles by a validated radioimmunoassay. Levels were high in rabbit atrium (66.76 +/- 7.04 pmol/g) but lower and superimposable in human and rat atria (28.18 +/- 3.20 and 30.22 +/- 2.45 pmol/g, respectively). Gel permeation chromatography revealed ir-dyn B eluting close to column exclusion and in forms with an apparently higher molecular weight than authentic dyn B in human and rat samples. In contrast, almost all the immunoreactivity from rabbit and guinea-pig acetic extracts eluted as a single peak in the region of standard dyn B. Reverse-phase high performance liquid chromatography of the pooled gel chromatography fractions of this peak showed up a molecular form with the same retention time as authentic dyn B and a second minor peak of unknown immunoreactive material eluting three fractions earlier. Digestion with carboxypeptidase B excluded the hypothesis that this latter could be dyn B-Arg14. Therefore, it might be a metabolite of endogenous dyn B recognized by the antibody used in this study.

Animals↗
PubMed1991

Pharmacology of spinal peptides affecting sensory and motor functions: dynorphins, somatostatins and tachykinins.

In recent years, the pharmacological activity of dynorphins and somatostatins on spinal sensory transmission has been intensively investigated with a view to developing new agents for pain control. Similarly, a series of tachykinin-related peptides with apparent receptor antagonist activity on endogenous substance P and neurokinins has been investigated. However, a number of observations suggest that these peptides, injected intrathecally in laboratory animals, not only exert a direct effect on nociceptive transmission but also affect a broader range of spinal somatomotor and autonomic functions and may cause peculiar neurotoxic effects that are not elicited by a large number of peptides affecting spinal neurotransmission. This article makes a critical review of their pharmacological activity on spinal sensory and motor functions and briefly touches on their anatomical and functional organization in the spinal cord.

Amino Acid Sequence↗
PubMed1990

Gi proteins and calcium in dynorphin-induced hypothermia and behaviour.

The intracerebroventricular (i.c.v.) administration of pertussis toxin (0.5 microgram) to rats significantly reduced the hypothermic and behavioural effects (episodic bizarre postures characterized by limb rigidity and followed by barrel rolling) induced by i.c.v. dynorphin A (10 micrograms). These central effects of dynorphin A thus appear to be initiated at a receptor site that interacts with G proteins substrates sensitive to pertussis toxin. Dynorphin A-induced hypothermia was also significantly reduced by i.c.v. pretreatment with the Ca2+ antagonist, verapamil (10 micrograms), although verapamil per se did not modify the behavioural effects elicited by the peptide.

Animals↗
PubMed1990

Antinociceptive profile of intracerebroventricular salmon calcitonin and calcitonin gene-related peptide in the mouse formalin test.

The effects of intracerebroventricularly administered salmon calcitonin (sCT) and calcitonin gene-related peptide (CGRP) on the behavioural response of the mouse to formalin injections were investigated. Mice lick their hindpaws for 5 min after formalin injections, then stop, and resume intensive licking for another 10 min beginning 20 min after the injections. Both peptides reduced the nociceptive response in the two phases of the test (0-5 and 20-30 min after formalin injection). Antinociceptive A50 values were 3.3 micrograms/mouse and 4.7 micrograms/mouse respectively in the first phase for sCT and CGRP. The effects of sCT and CGRP appeared to be dose-dependent in the first phase. Since in the second phase sCT appeared more effective and CGRP gave a bell-shaped curve, possible differences in the mechanisms of action of the peptides in the two response intervals of the test are suggested.

Analgesia↗
PubMed1990

Distribution and characterization of VIP-related peptides in the rat spinal cord.

The possible existence in the rat spinal cord of a peptide related to VIP, VIP(22-28), has been evaluated. VIP contains paired basic aminoacid residues at which posttranslational cleavage of these peptides might occur. The lumbo-sacral region of rat spinal cord had the most VIP(22-28)-like immunoreactivity (ir-VIP(22-28]. Chromatographic analysis of spinal extracts showed that ir-VIP(22-28) consisted of two major peaks, one eluting as authentic VIP(1-28) and the other as VIP(22-28). HPLC confirmed these results, revealing the presence of intact VIP(1-28) and two or more less hydrophobic peptides, one of which corresponded to authentic VIP(22-28). The other two components found have not yet been identified. Further studies are necessary to provide information on the biological significance of VIP(22-28).

Animals↗
PubMed1990

Pored domes in the capillary endothelial cells of teleost (Prochilodus scrofa) intestinal mucosa.

The mucosal capillaries of the proximal intestine in a freshwater teleost (Prochilodus scrofa) are lined by an endothelial sheet with several fenestrated or pored domes, which are observed both in the thinner and thicker cytoplasmic extensions of the endothelium. These domes sometimes communicate between the inner and the outer side of the capillary wall, forming a transendothelial channel-like structure with internal diaphragms. The pored domes seem to be a frequent structure in fishes. Their ultrastructure in the proximal segment of the intestine, where the flow of substances through the endothelium is intense, is described.

Animals↗