Biomedical subjects

E Ragazzoni

Publications and source records attributed to E Ragazzoni.

At least 19 recordsLinked to original sources

PubMed2003

Validation of 8-isoprostane and prostaglandin E(2) measurements in exhaled breath condensate.

OBJECTIVE: To qualitatively validate radioimmunoassays for 8-isoprostane and prostaglandin (PG) E(2) in exhaled breath condensate. SUBJECTS: Twenty-two subjects with different lung diseases attended the outpatient clinic on one occasion for exhaled breath condensate collection. METHODS: Samples were pooled together and purified by reverse phase high performance liquid chromatography (RP-HPLC). The eluted fractions were assayed for 8-isoprostane-like immunoreactivity and PGE(2)-like immunoreactivity by radioimmunoassays. In addition, simultaneous measurements of exhaled breath condensate unextracted samples with two anti-8-isoprostane and anti-PGE(2) sera with different cross-reactivity were performed. RESULTS: A single peak of 8-isoprostane-like immunoreactivity and PGE(2)-like immunoreactivity co-eluting with 8-isoprostane (retention time: 13 min) and PGE(2) (retention time: 21 min) standards, respectively, was identified by radioimmunoassays. Testing with two different antisera showed similar results for both 8-isoprostane-like immunoreactivity (limits of agreement = 4.5 pg/ml and - 4.1 pg/ml, n = 12) and PGE(2)-like immunoreactivity (limits of agreement = 6.1 pg/ ml and - 6.1 pg/ml, n = 12). CONCLUSION: This study provides evidence for the specificity of the radioimmunoassays for 8-isoprostane and PGE(2) in exhaled breath condensate. This is critical for proposing these markers as a non-invasive way for monitoring airway inflammation.

Breath Tests↗

PubMed2003

Validation of leukotriene B4 measurements in exhaled breath condensate.

OBJECTIVE: To qualitatively validate an enzyme immunoassay to measure leukotriene B4 in exhaled breath condensate. Exhaled breath condensate is a new non-invasive method to monitor airway inflammation. SUBJECTS: Twenty-two subjects with different lung diseases attended the outpatient clinic on one occasion for exhaled breath condensate collection. METHODS: Samples were pooled together and purified by reverse-phase high-performance liquid chromatography. The fractions eluted were assayed for leukotriene B4 by enzyme immunoassay. RESULTS: A single peak of leukotriene B4-like immunoreactivity co-eluting with leukotriene B4 standard (retention time: 24 min) was identified by enzyme immunoassay. Reverse phase-high performance liquid chromatography peak of leukotriene B4 was clearly separated from those of 6-trans-leukotriene B4 (retention time: 14 min) and leukotriene B5 (retention time: 18 min) for which the antiserum used in the enzyme immunoassay had the highest cross-reactivity. Leukotriene B4 recovery was 64%. CONCLUSIONS: This study provides evidence for the presence of leukotriene B4 in the exhaled breath condensate and the specificity of the enzyme immunoassay used.

Breath Tests↗

PubMed2000

A possible prolactin-related adverse effect of certain antineoplastic anthracyclines.

Nonhormonal antineoplastic therapy can affect the endocrine system with consequent effects on the growth of hormone-sensitive tumors. Amongst anthracycline antibiotics, we have found daunorubicin and epirubicin able to acutely stimulate prolactin (PRL) secretion both in vivo, in the rat, and in vitro, from rat anterior pituitary cell cultures. Despite a similar structure, doxorubicin showed no such activity. Considering the possible role of PRL in breast cancer cell proliferation, the effects of certain anthracyclines might be viewed as an adverse drug reaction involving the anterior pituitary gland.

Animals↗

PubMed2000

Evidence that hydrogen sulphide can modulate hypothalamo-pituitary-adrenal axis function: in vitro and in vivo studies in the rat.

The gas hydrogen sulphide (H2S) is normally produced in large amounts in the central nervous system during the metabolism of sulphur-containing aminoacids. H2S was recently shown to influence long-term potentiation in the rat hippocampus; this finding suggested that the gas may act as a neuromodulator in the brain. We therefore tested the effect of the gas on the release of corticotropin-releasing hormone (CRH) from rat hypothalamic explants. CRH immunoreactivity in the incubation media was taken as a marker of peptide release. We found that the addition of NaHS to incubation media was consistently associated with a concentration-dependent decrease in KCl-stimulated CRH release, whereas basal secretion was unaffected. Increased endogenous H2S production may be also obtained using an indirect precursor of H2S formation, S-adenosyl-L-methionine (SAMe). The latter mimicked the effects of NaHS, since it reduced potassium-stimulated CRH release. In vivo, SAMe showed no effect on hypothalamo-pituitary-adrenal (HPA) function under resting conditions, but inhibited stress-related glucocorticoid increase.

Adrenal Glands↗

PubMed2000

[Safety in dialysis rooms. Biologic risks].

The search for quality in the health service cannot lead aside the safety of its operators and users, subject to the well defined parameters of Law 626. This study makes a preliminary examination of the accidents occurring in our Health District which comprises three hospitals, 600 beds and 1,800 employees. A total of 172 accidents have been reported. The percentages can be broken down between the various sectors: 73% of accidents involve nurses, 9% involve doctors and 1% administrative personnel. The greatest risk in hemodialysis is the biological factor (through accidental cuts or pricks which account for 67% of the accidents reported) and involves humans (both patients and personnel), monitors and environments as the sources of pathogens. The most frequently isolated germs are E. coli and Pseudomonas. It has been shown that prevention is above all based on the accuracy with which procedures are followed. The risk of hepatitis C has not yet been resolved, as is affinned in a review reported in the study. The HIV risk gives the greatest cause for concern, even if only 0.2% after exposure compared to 15-36 for HbsAg. Compliance with universal rules for prevention and post-exposure procedures provides an adequate guarantee for prevention.

Hazardous Substances↗

PubMed2000

Circulating interleukin-1-beta levels after acute and prolonged exposure to low temperatures: human and rat studies.

In this study we have investigated whether IL-1 acts as a mediator of stress responses elicited by exposure to low temperatures. We also sought whether IL-1 is released from the adrenal gland under basal conditions or after exposure to low temperatures. Normal and adrenalectomized (ADX) rats were used for acute studies, whereas the effects of a prolonged exposure were investigated in a group of human subjects during a 45-day stay in Antarctica. Circulating levels of interleukin-1beta (IL-1beta) were taken as a marker of systemic IL-1 production both in humans and rats. In the latter, serum corticosterone (Cort) was also estimated. In intact rats, exposure to low temperatures (-25 or -35 degrees C) for 30 or 90 min did not modify circulating IL-1beta levels with respect to controls taken at +20 degrees C. Adrenalectomy was associated with an increase in cytokine levels only in the group exposed to -35 degrees C for 90 min; such increase is statistically significant compared to all groups of normal rats, whatever the experimental condition, as well as to ADX rats exposed to +20 degrees C and -25 degrees C for 30 and 90 min. In normal rats, the increase in circulating Cort levels was already maximal after exposure to -25 degrees C for 30 min. In humans, circulating IL-1beta levels after 45 days in Antarctica were significantly lower than those measured on arrival in the same subjects. Thus, no change in circulating IL-1beta was associated with acute low-temperature stress in rats, whereas a marked decrease in serum cytokine was observed in humans after prolonged exposure to a cold environment. Experiments with ADX rats indicated that the contribution of the adrenal glands to total-body IL-1beta production is negligible or absent.

Adrenalectomy↗

PubMed1999

Inhibition of heme oxygenase in the central nervous system potentiates endotoxin-induced vasopressin release in the rat.

Previous in vitro studies have shown that increases in endogenous carbon monoxide (CO) generation via activation of the enzyme heme oxygenase (HO) within the rat hypothalamus are associated with the reduced release of the neuropeptides, vasopressin (AVP) and oxytocin, while evidence concerning corticotrophin-releasing hormone (CRH) is controversial. The present study investigated whether there is also a functional relationship between the HO-CO pathway and AVP and corticosterone (Cort) in vivo. Male Wistar rats were challenged with bacterial lipopolysaccharide (LPS) at doses producing significant activation of the hypothalamo-pituitary-adrenal (HPA) axis. LPS was given alone or after pretreatment with the HO inhibitor Sn-protoporphyrin-9 (SnPP9). The latter was injected either intraperitoneally (i.p.) or by intracerebroventricular (i.c.v.) route. SnPP9 given i.p. failed to modify either basal or LPS-stimulated levels of AVP and Cort. On the contrary, i.c.v. SnPP9 strongly potentiated LPS-induced AVP release and significantly enhanced basal serum Cort levels, although it failed to potentiate stimulation by LPS. The LPS + i.c.v. SnPP9 also significantly reduced the hypothalamic stores of AVP compared to controls, correlating with increased circulating levels of AVP. Taken collectively, these data are in concordance with previous in vitro observations showing that the HO-CO pathway acts centrally to attenuate endotoxin-stimulated AVP release, while having less effects on the pituitary-adrenal axis.

Animals↗

PubMed1999

Leptin stimulates prostaglandin E2 and F2alpha, but not nitric oxide production in neonatal rat hypothalamus.

Leptin, an adipocyte-derived 16 kDa polypeptide hormone, has been found to regulate food intake and thermogenesis by modulating stimulatory and inhibitory pathways in the feeding circuitry of the hypothalamus, among which corticotropin releasing hormone (CRH). Nitric oxide (NO) and prostaglandins have been shown to be involved in both CRH neurosecretion and feeding regulation. We have investigated the role of NO, prostaglandin E2 and prostaglandin F2alpha as mediators of the hypothalamic effects of leptin and their possible involvement in leptin-stimulated CRH secretion. Using primary cultures of neonatal (5- to 6-day-old) rat hypothalamic cells, we confirmed that leptin (0.1-10 nM) stimulates CRH secretion. This effect was not blocked by L-N(G)-nitro-methyl-arginine (L-NAME, 100 microM), a NO-synthase competitive inhibitor; and leptin did not stimulate NO production. Cyclooxygenase inhibition by indomethacin (10 microM) did not modify leptin-induced CRH secretion, while leptin stimulated prostaglandin E2, and prostaglandin F2alpha secretion. In conclusion, leptin-induced hypothalamic CRH secretion is not modulated by NO-synthase- or cyclooxygenase-mediated mechanisms; leptin does not stimulate NO production, but it stimulates prostaglandin E2 and F2alpha production, which could add to the growing list of mediators of leptin signaling in the hypothalamus.

Animals↗

PubMed1999

Anaphylaxis increases 8-iso-prostaglandin F2alpha release from guinea-pig lung in vitro.

8-Iso-prostaglandin F2alpha, release from isolated and perfused guinea-pig lung was measured by radioimmunoassay. 8-Iso-prostaglandin F2alpha release was detectable under basal conditions and increased 10-fold during antigen-induced bronchoconstriction, concomitant with the increase of thromboxane B2 and prostaglandin E2. The anti-8-iso-prostaglandin F2alpha serum used in the radioimmunoassay seems to be quite specific for this compound. Pretreatment of lungs with indomethacin (a non-selective inhibitor of cyclooxygenase) reduced 8-iso-prostaglandin F2alpha release under basal conditions and completely abolished the increase observed during lung anaphylaxis. Pretreatment of lungs with NS 398 (N-[2-cyclohexyl]-4-nitrophenyl methanesulphonamide), a selective inhibitor of cyclooxygenase-2, did not change basal or antigen-induced 8-iso-prostaglandin F2alpha release at all. We conclude that under basal conditions guinea-pig lung perfusates contain low levels of 8-iso-prostaglandin F2alpha-like immunoreactivity, which increase 10-fold during antigen-induced bronchoconstriction. This isoprostane seems to be derived from the cyclooxygenation of arachidonic acid via the constitutive form of cyclooxygenase.

Anaphylaxis↗

PubMed1999

[Chronic pain during dialysis. Pharmacologic therapy and its costs].

BACKGROUND: There is very little research into the problem of chronic pain in dialysed patients, despite the fact that pain is a widely diffused phenomena amongst these patients. This work proposes to evaluate the intensity of pain, supply a scale of levels of intervention, with an indication of the consumption and relative costs of pharmacological therapies. METHODS: 37 out of 100 patients undergoing haemodialysis suffer chronic pain. Aetiological research has shown that osteoarticular pain (24 cases), is the most common, peripheral vascular pain (3 cases), is subjectively and indirectly considered to be the most serious form. Nine cases have presented pain of a neuromuscular origin, whilst one case of a neoplastic origin. The degree of personal invalidism shows serious invalidism in 11 cases. RESULTS: The therapeutic file that forsaw four levels of pharmacological intervention (1st levels: FANS, 2nd level: Codeine+paracetamol, 3rd level: Buprenorphine, 4th level: Morphine for os), accompanied by instrumental and pharmacological support intervention, has proved to be indispensable in confronting the problem. Through pharmacy data, we have noticed a progressive increase over the year in the use of analgesic medicines, of which we can confirm the effectiveness, tolerability, low level of side-effects, at low costs. CONCLUSIONS: In our opinion chronic pain in dialysed patients should not be neglected. The perfection of diagnostic techniques, the discovery of pain-killers with reduced side-effects, the multidisciplinary approach, and reduced costs of treatment, are all valid arguments in favour of an intervention that improves the quality of life of these patients, already so compromised by the nature of the illness itself.

Acetaminophen↗

PubMed1999

[Nephrotic syndrome refractory to conventional therapy].

BACKGROUND: Prednisone is the choice medicine in Nephrotic Syndrome (NS) treatment, possibly associated with immunosuppressor medicines (cyclophosphamide or chlorambucil), either in case of NS resistance at cortisone therapy or with frequent relapses. Cyclosporin A (CyA) use has been recently proposed, due to its inhibitory effect on the IL2 and lymphokine release, with a permeabilizing effect on the glomerular membrane. The purpose of this study is to evaluate the CyA antiproteinuric effectiveness with NS conventional therapy refractory patients. METHODS: Six patients (3 females and 3 males) have been treated with CyA (4 +/- 0.5 mg/Kg/die) associated with low corticosteroid dosages. RESULTS: During the treatment, proteinuria reduced in 5 patients, at less than 1/3 of pre-treatment values, for 4 patients this happened starting from the 2nd month of therapy, while after the 12th for the fifth patient. The sixth patient has now a 2/3 reduction compared to the initial one and he is at the 3rd month of therapy. During the CyA treatment, further to the proteinuria reduction, a total proteinemia values increase and a cholesterolemia and tryglyceridemia reduction has been observed, while creatinine and PA have not changed. CONCLUSIONS: Four out of the six treated patients have been respectively under therapy for 2,3,12,30 months. Two stopped CyA therapy: one after 18 months due to clinical stability, still present after 2 years from interruption; one after 9 months with a stable clinical picture for just three months, since she was longing for a pregnancy, achieving a quick proteinuria relapse.

Adolescent↗

PubMed1998

Antipyrine clearance in chronic and neoplastic liver diseases: a study of 518 patients.

Antipyrine metabolism is widely used as an index of the drug-metabolizing reserve of the liver. It is well known that metabolism of this drug is impaired in subjects with acute hepatitis or cirrhosis, but conflicting data have been reported regarding patients with chronic postinfectious hepatitis or liver cancer. We studied conventional liver-function parameters and antipyrine metabolism (antipyrine per o.s. 18 mg/kg) in 518 subjects. One hundred and one patients had liver metastases (various primaries). Based on the number and size of lesions, the hepatic involvement was considered minimal in 47 and massive in 54 (groups B1 and B2, respectively). One hundred and two had chronic active hepatitis (CAH); 51 patients with histological evidence of fibrosis/early cirrhosis and 51 patients were without histological evidence of fibrosis/early cirrhosis. Ninety-two had histologically confirmed cirrhosis (group D), and the remaining 120 had cirrhosis and hepatocellular carcinoma (group E). The control group was composed of 103 subjects with healthy livers (group A). Antipyrine clearance (AP Cl) in CAH patients with fibrosis (0.246 +/- 0.98 mL/min per kg) was similar to that observed in patients with cirrhosis (0.223 +/- 0.148 mL/min per kg), and both values were significantly lower than that found in CAH patients without fibrosis (0.406 +/- 0.159 mL/min per kg, P < 0.01). Antipyrine clearance in patients with liver metastases (0.426 +/- 0.174 mL/min per kg) was similar to that of the healthy group (0.489 +/- 0.210 mL/min per kg). Cirrhotics and cirrhotics with hepatocellular carcinoma (HCC) presented similar degrees of impairment. Antipyrine clearance was positively correlated with serum albumin (r2 = 0.10, P = 0.01) and prothrombin time (r2 = 0.129, P < 0.01) in all groups, except those with liver metastases. In patients with CAH, the presence of fibrosis/cirrhosis is associated with impaired antipyrine metabolism. The lack of impairment in groups with liver metastases suggests that the functional hepatic reserve is maintained even in the presence of massive neoplastic invasion.

Adolescent↗

PubMed1998

[Heart failure resistant to drug therapy. Nephrologic approach].

BACKGROUND: The congestive heart failure (IV cl. NYHA) refractory to medical therapy, can be treated with ultrafiltrative method such as extracorporeal ultrafiltration (UF), intermittent veno-venosus hemofiltration, intermittent peritoneal dialysis (IPD) or chronic ambulatory peritoneal dialysis (CAPD). METHODS: Sixty-one patients suffering from SCC have been managed by combining medical therapy with ultrafiltrative treatment. RESULTS: 28% (17 patients) died within a week from ultrafiltrative therapy beginning. 39% (24 patients) took up to respond to medical therapy (responders). 33% (20 patients) didn't give a proper response to pharmacological therapy (non responders), therefore a ultrafiltration program with chronic ambulatory peritoneal dialysis (CAPD) has been undertaken. Among ultrafiltrative methods applied to patients, IVVH is the most effective. Clinical parameters analysis, relevant to dehydration acute phase, points out: an evident loss of corporeal weight between dehydration pre-post phases in all 3 groups, with statistically significant results; a SAP values reduction between the beginning and the end of treatment in all 3 groups; a PAD values reduction in the group of deceased and non responders. This value remains stable in responders group. Non responders patients, inserted in a ultrafiltration program with CAPD present the following survival rate: 55%: 6 months; 35%: 1 years; 15%: 4 years. These patients maintain a good self-management in 50%, sufficient in 35% and totally partner-dependent in 15%. CONCLUSIONS: Ultrafiltration method together with pharmacological therapy allows a resetting of neuro-endocrine and electrolytic system in refractory congestive heart failure patients and a recovery of a pharmacological response. Without such a response a cardio-circulatory balance can be maintained through a CAPD method.

Acute Kidney Injury↗

PubMed1997

Assessment of the acrylic resin Technovit 7200 VLC for studying the gingival mucosa by light and electron microscopy.

Technovit 7200 VLC is an acrylic resin formulated for embedding undecalcified hard tissues which are prepared for light microscopy according to a cutting-grinding technique. To employ this resin for embedding and cutting soft tissues by ultramicrotomy, we carried out a qualitative study on biopsies of canine gingival mucosa using light and transmission electron microscopy. For a critical evaluation of this resin, some biopsies were embedded in Agar 100, an epoxy resin widely used in morphological studies. At the light microscopic level the samples embedded in Technovit 7200 VLC showed good morphology and excellent toluidine blue staining of different cell types and extra cellular matrix. At the ultrastructural level, nuclei, cytoplasmic organelles, collagen fibrils and ground substance appeared well preserved and showed high electron density. The acrylic resin was stable under the electron beam and its degree of shrinkage appeared to be very low. We conclude that Technovit 7200 VLC can be employed for ultramicrotomy for both light and electron microscopic investigation of soft tissues.

Acrylic Resins↗

PubMed1997

A procedure for preparing undecalcified and unembedded bone sections for light microscopy.

We have developed a procedure for light microscopic investigation of undecalcified and unembedded bone sections. Biopsy samples of human metatarsus and femur and rat femur were fixed in aldehydes and sectioned with a cutting machine equipped with a diamond saw blade. Free sections 100-150 microns thick, stained with toluidine blue and von Kossa, did not show artifacts following the cutting, and the spatial relations of mineralized and nonmineralized components remained intact. Compact and trabecular bone, bone marrow and all cell types appeared well preserved and easily recognizable. Our procedure provides a simple and rapid method for preparing bone sections which undergo no chemical treatment other than fixation. This method is a useful alternative to standard histological protocols for studying bone specimens.

Animals↗

PubMed1997

A comparative light microscopic study of human midpalatal suture and periodontal ligament.

In order to provide information on the morphological features of both human midpalatal suture and periodontal ligament, bioptic samples were obtained from patients whose age was between 10 and 30 years. The samples were embedded in epoxy resin, sectioned, stained with toluidine blue and observed by light microscopy. The periodontal ligament and the midpalatal suture appeared very similar with regard to the histological characteristics of the connective tissue but differed in the nature of the bone tissue associated to it. The alveolar bone lining the periodontal ligament was a bundle bone whereas the bone lining the connective tissue of the sutures was both lamellar and bundle bone. The absence of osteoblasts, osteoclasts or undifferentiated cells in the sutures under examination suggests that they are subjected to a slow bone turnover during their life cycle. On the contrary, the presence of mesenchymal cells in the periodontal ligament supports the notion that these cells are precursors of osteogenic cells involved in the high rate of bone remodelling that characterizes the alveolar bundle bone. The present results are discussed taking into account physiologic and therapeutic aspects of the two structures under examination.

Humans↗

PubMed1996

Interleukin-1 beta specifically stimulates nitric oxide production in the hypothalamus.

In previous experiments we have shown the role of nitric oxide (NO) in basal and interleukin-1 beta (IL-1 beta)-induced CRH and ACTH release in vitro. Now, we have studied the possible production of NO from hypothalamic cell cultures, particularly after IL-1 beta stimulation or L-NOArg inhibition, by high performance liquid chromatographic (HPLC) assay of L-citrulline production, adding further evidence for a role of NO in IL-1 beta activity in the hypothalamus.

Animals↗

PubMed1996

Interleukin-1 beta release from rat gastric fundus.

Interleukin-1 (IL-1) is known to regulate gastric functions via a central action at the hypothalamic level, and it has also been shown that this cytokine can directly modulate rat gastric motility. This study was conducted to determine whether IL-1 beta is produced and released by rat gastric fundi in vitro. IL-1 beta immunoreactivity was released in measurable amounts from explanted rat gastric tissue. This release was not affected by electrical stimulation of the gastric strips or by agents that induce IL-1 biosynthesis. It could be inhibited only by the glucocorticoid dexamethasone. Ex vivo experiments confirmed the inhibitory role of glucocorticoids and showed that IL-1 beta release can be inhibited by agents that reduce gastric acid secretion, suggesting that the latter might stimulate IL-1 beta synthesis and release. In light of the well-established gastroprotection exerted by IL-1, H(+)-induced IL-1 beta release might serve as a protection against mucosal injuries caused by acid secretion, and the inhibition of this release by glucocorticoids might be involved in the pathogenesis of gastric damage associated with severe stress or steroid therapy.

Adrenalectomy↗