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Biomedical subjects

S Milano

Publications and source records attributed to S Milano.

At least 19 recordsLinked to original sources
PubMed2000

Interleukin-12 in human boutonneuse fever caused by Rickettsia conorii.

Interleukin (IL)-12 contributes to the resistance against a number of intracellular pathogens. We examined the potential biological role of IL-12 by studying peripheral blood mononuclear cells (PBMC), its production and its effect on cytokine synthesis in 20 Sicilian patients with boutonneuse fever (BF) caused by Rickettsia conorii. Data indicate that PBMC from acute BF patients were able to produce IL-12 in response to in vitro stimulation with rickettsial antigen (Ag): this production was higher than that detected in healed patients. Monocytes were the main source of IL-12 by PBMC from BF patients. IL-12 secretion by in vitro Ag-stimulated PBMC from BF patients was potentiated by recombinant interferon gamma (IFN-gamma) or anti-IL-10 monoclonal antibodies (MoAbs). Furthermore, the treatment with anti-IL-12 MoAbs reduced the IFN-gamma synthesis. These results indicate that treatment of PBMC from acute BF patients with IL-12 shifted the response toward a Th1-type cytokine response. Furthermore, IL-12 and IFN-gamma are interdependent and they may be associated with the immunity against rickettsias.

Boutonneuse Fever↗
PubMed1999

Differential up-regulation of circulating soluble selectins and endothelial adhesion molecules in Sicilian patients with Boutonneuse fever.

In 150 patients with Boutonneuse fever (BF), caused by Rickettsia conorii, we studied the plasma levels of soluble L-selectin (sL-selectin), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1) and E-selectin (sE-selectin) in various phases of disease to clarify their role in disease evolution. Results indicate that during the acute phase of BF there is a significant increase in the serum levels of sL-selectin, sE-selectin, sVCAM-1 and sICAM-1. sL-selectin and sVCAM-1 returned to normal levels in the third week of disease, whereas sE-selectin and sICAM-1 persisted at significantly high levels even after the third week. The secretion of these soluble CAMs in BF is mainly the result of leucocyte expression and endothelial cell activation, but secretion also appears to mediate anti-inflammatory activities, moderating leucocyte adhesion and reducing in particular lymphocyte and monocyte infiltration. Only sL-selectin serum levels were found to correlate with the acute phase of infection characterized by fever.

Adult↗
PubMed1998

Tetracycline inhibits the nitric oxide synthase activity induced by endotoxin in cultured murine macrophages.

Here we investigate the effects of tetracycline base and of a semi-synthetic tetracycline derivative, doxycycline, on the induction of inducible nitric oxide synthase and, hence, on the production of nitric oxide (NO) by lipopolysaccharide in J774 macrophage cultured in vitro. The treatment of J774 line with tetracycline base (6.25-250 microM) or doxycycline (5-50 microM) dose-dependently decreased the lipopolysaccharide-stimulated (1 microg/ml) inducible NO synthase activity and, consequently, nitrite formation. For instance, the inhibition was 70% for tetracycline base at 250 microM and 68% for doxycycline at 50 microM. The inhibitory effect of tetracyclines was due neither to a reduction in the viability of the cells, studied as colorimetric 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) reduction assay, nor to an indiscriminate inhibition of total protein synthesis, but to a specific decrease in inducible NO synthase protein content in the cells, as attested by the significant reduction of the expression of inducible NO synthase, assayed by sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. However, no effect of tetracyclines on inducible NO synthase mRNA accumulation could be demonstrated in lipopolysaccharide-stimulated macrophage line, suggesting that the inhibitory effect of tetracyclines on NO synthesis involves post-transcriptional events. The reduction in lipopolysaccharide-stimulated nitrite accumulation produced by tetracyclines was significantly less when they were applied 6 h after lipopolysaccharide and absent 12 h after lipopolysaccharide, indicating that tetracyclines modify an early event in inducible NO synthase activation operating after mRNA transcription. The findings presented in this study indicate that the modulation of NO synthesis is another possible pathway by which tetracyclines may function as anti-inflammatory compounds.

Animals↗
PubMed1998

Modifications of general parameters of immune activation in the sera of Sicilian patients with Boutonneuse fever.

The serum levels of beta2-microglobulin (beta2-M), soluble HLA class I antigen (sHLA-I), soluble CD4 (sCD4) and CD8 (sCD8) were studied in 98 Sicilian patients with Boutonneuse fever (BF). In different stages of infection all markers were significantly increased in sera from Sicilian patients with acute BF compared with healthy controls. sCD8 and sHLA-I reached the peak in the second week after the onset of symptoms, whereas sCD4 and beta2-M reached the peak in the first week. Afterwards sCD8 decreased to the levels of controls within the third week, the other parameters decreased later and were unmodified until the third week of infection. Significant correlations were found between sCD4 and sCD8 and the sIL-2R, as well as between serum levels of beta2-M and sCD8. The reduction of CD3+ and CD4+ and the increase of CD8+ T cells in the blood indicate that these cells are involved in the response to rickettsia, and their activation might be in part responsible for the release of sCD4 and sCD8. Our data suggest that these soluble markers, indexes of immune activation of T cells both in the circulation and the affected tissues, may be used in monitoring BF evolution.

Adult↗
PubMed1998

Doxycycline reduces mortality to lethal endotoxemia by reducing nitric oxide synthesis via an interleukin-10-independent mechanism.

It was demonstrated that doxycycline protected BALB/c mice injected intraperitoneally with bacterial lipopolysaccharide (LPS) against lethal septic shock. Doxycycline (at 1.5 mg/kg) exerted its protective effect by inhibiting nitrate production by an interleukin-10-independent mechanism. Experiments carried out in vitro also indicated that doxycycline inhibited NO synthesis by LPS-activated macrophages without inducing any significant modification in interleukin-10 release. These data suggest that the direct inhibition of nitrate release is the main mechanism of the antiinflammatory activity of doxycycline in septic shock.

Animals↗
PubMed1998

Modulation of nitric oxide production by tetracyclines and chemically modified tetracyclines.

Chemically modified tetracyclines (CMTs) dose-dependently decreased inducible nitric oxide synthase (iNOS) and, consequently, nitric oxide (NO) formation by the lipopolysaccharide (LPS)-stimulated J774 line. The inhibitory effect was due to a specific reduction in the iNOS protein content in the cells, as attested by Western blot analysis and by the inhibition of iNOS mRNA accumulation. Furthermore, CMTs cause a dose-dependent increase in cell death in the J774 line mediated by the NO-independent apoptotic mechanism.

Animals↗
PubMed1997

Structure-activity relationship studies of the amide functionality in (p-O-sulfamoyl)-N-alkanoyl tyramines as estrone sulfatase inhibitors.

Recently, we reported the synthesis and biomedical studies of a series of (p-O-sulfamoyl)-N-alkanoyl tyramines as nonsteroidal estrone sulfatase inhibitors. One of the most potent inhibitors in this series is (p-O-sulfamoyl)-N-tridecanoyl tyramine 1 with an 1C50 value of 61.3 nM. In this study, we synthesized four analogs of 1 (compounds 2-5) to investigate the structure-activity relationships of the amide functionality in (p-O-sulfamoyl)-N-tridecanoyl tyramine. Replacement of the amide functionality in 1 with an ethylene moiety to form the alkyl analog 5 resulted in complete loss of sulfatase inhibitory activity (IC50 of 61.3 nM vs. > 20 microM). The keto, hydroxy, and ester analogs (inhibitors 2-4) are 8-15 times less in affinity to the sulfatase than inhibitor 1. However, their inhibitory activities are significantly higher than the alkyl analog 5. The results suggest that the amide functionality is favorable for sulfatase inhibitory activity and that there may be a hydrogen bonding component to the enzyme interaction in this region.

Amides↗
PubMed1997

Effect of partially modified retro-inverso analogues derived from C-reactive protein on the induction of nitric oxide synthesis in peritoneal macrophages.

1. The ability of three modified tetrapeptides, representing fragments of the C-reactive protein (CRP) sequence and stabilized in the first peptide bond by retro-inverso modification, to affect the secretion of nitric oxide (NO) was studied in macrophages of BALB/c mice. 2. These tetrapeptides, resembling the aminoacid sequence of tuftsin (CRP 1, H-gThr-(R,S)mLys-Pro-Leu-OH, ITF 1192; CRP II, H-gGly-(R, S)mLys-Pro-Arg-OH, ITF 1127; CRP III, H-gThr-(R,S)mLys-Pro-Gln-OH. ITF 1193), were able to induce NO synthesis by peritoneal macrophages in a dose-dependent manner; the most stimulating dose was 1000 ng ml-1 for CRP II and 100 ng ml-1 for CRP I and CRP III. NO synthesis was not strictly dependent on lipopolysaccharide (LPS) activation. 3. The enhanced effect of retro-inverso CRP-related analogues on the expression of iNOS (inducible NO synthase) was confirmed by higher levels of iNOS activity in the cytosol and by the increase in iNOS protein, as evaluated by Western blot analysis, in macrophages stimulated by CPR compared with untreated ones. 4. The production of NO by retro-inverso CRP-peptide analogues was significantly inhibited by dexamethasone (20 microM), NG-monomethyl-L-arginine (L-NMMA) (500 microM) and pyrrolidine dithiocarbamate (PDTC) (100 microM). 5. Retro-inverso CRP-peptide analogues stimulated macrophages to produce high levels of interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha) in the presence of LPS. 6. Retro-inverso CRP-peptide analogues stimulated NO synthesis by the enhancement of endogenously produced IL-1 and TNF-alpha, as the treatment of peritoneal macrophages with LPS in the presence of neutralizing anti-IL-1 and anti-TNF monoclonal antibodies (mAbs) reduced retro-inverso analogue-induced NO secretion. Data indicate a predominant role for IL-1 alpha in the induction of NO secretion by retro-inverso analogues. 7. These results suggest that retro-inverso CRP derived analogues act as costimulators of NO and cytokine synthesis in macrophages. The mechanisms by which they cause iNOS induction appear to be strongly dependent on the activation of nuclear factor-kappa B (NF-kappa B).

Animals↗
PubMed1997

Intraperitoneal injection of tetracyclines protects mice from lethal endotoxemia downregulating inducible nitric oxide synthase in various organs and cytokine and nitrate secretion in blood.

We have tested whether tetracyclines (TETs) are able to protect mice from lipopolysaccharide (LPS)-induced shock, a cytokine-mediated inflammatory reaction. Mice, injected with a single dose of tetracycline base (TETb; 1.5, 10 and 20 mg/kg of body weight) or doxycycline (DOXY; 1.5 mg/kg), were significantly protected from a lethal intraperitoneal injection of LPS (500 micrograms per mouse). TETs acted in early events triggered in response to LSP; in fact, they were no longer significantly protective if injected more than 1 h after the injection of endotoxin. LPS-treated mice protected by TETs showed a significant inhibition of tumor necrosis factor alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha), and nitrate secretion in the blood, events that were directly related with the survival. In mice treated with TETs a significant decrease of inducible nitric oxide synthase (iNOS) activity was observed in spleen and peritoneal cells compared with that detected in mice treated with LPS alone. Furthermore, TETs were found to inhibit NO synthesis by peritoneal macrophages stimulated in vitro with LPS. On the contrary, TETs were unable to decrease the ability of the macrophages to synthesize IL-1 alpha and TNF-alpha in vitro. These results indicate that TETs are not able to act directly on the synthesis of these cytokines, but they may modulate other pathways that could in turn be responsible for the inhibition of IL-1 alpha and TNF-alpha synthesis. Altogether, these results indicate that TETs are advantageous candidates for the prophylaxis and treatment of septic shock in mice, having both antimicrobial activity and the ability to inhibit endogenous TNF-alpha, IL-1 alpha, and iNOS, hence, exerting, potent anti-inflammatory effects.

Animals↗
PubMed1996

Raphe 5-HT1A autoreceptors, but not postsynaptic 5-HT1A receptors or beta-adrenoceptors, restrain the citalopram-induced increase in extracellular 5-hydroxytryptamine in vivo.

In vivo microdialysis in rat ventral hippocampus was used (i) to verify the importance of 5-HT1A autoreceptors in the raphe as targets for drugs that enhance the citalopram-induced elevation of forebrain 5-hydroxytryptamine (5-HT), and (ii) to further examine the specificity of (-)-penbutolol in this regard. The selective 5-HT1A receptor antagonist WAY100635 (s.c., or intra-raphe) or the mixed 5-HT1A/1B/beta-adrenoceptor antagonist (-)-penbutolol (s.c.), potentiated the citalopram-induced 5-HT rise, whereas local "reverse' dialysis of WAY100635 into the ventral hippocampus did not. Furthermore, the (-)-penbutolol-induced augmentation proved stereoselective and not mediated by beta-adrenoceptors (no effect of s.c. (+)-penbutolol, or beta 1- and beta 2-adrenoceptor blockers (betaxolol, ICI118.551)). These data provide direct evidence that increased stimulation of 5-HT1A autoreceptors in the midbrain raphe impedes the effect of citalopram on forebrain extracellular 5-HT, whereas neither postsynaptic 5-HT1A receptors nor beta-adrenoceptors appear to be involved.

Adrenergic beta-Antagonists↗
PubMed1996

Activity of dorsal respiratory group inspiratory neurons during laryngeal-induced fictive coughing and swallowing in decerebrate cats.

Membrane potential changes and/or discharges from 36 inspiratory neurons were recorded intracellularly in the dorsal respiratory group (DRG; i.e., the ventrolateral subdivision of the nucleus tractus solitarii) in decerebrate, paralyzed, and ventilated cats. Electrical activities were recorded from both somata (n = 10) and axons (n = 26). Activities during quiet breathing were compared with those observed during fictive coughing and swallowing evoked by repetitive electrical stimulation of afferent fibers of the superior laryngeal nerve (SLN). These nonrespiratory behaviors were evident in paralyzed animals as characteristic discharge patterns of the phrenic, abdominal, and hypoglossal nerves. Twenty-six neurons exhibiting antidromic action potentials in response to electrical stimuli applied to the cervical (C3-5) spinal cord were classified as inspiratory bulbospinal neurons (IBSNs). These neurons were considered as premotoneurons. The remaining 10 inspiratory neurons (I-NAA) were not antidromically activated by electrical stimuli applied to either cervical spinal cord or ipsilateral cervical vagus. These neurons are thought to be propriobulbar neurons. We recorded the activity of 31 DRG inspiratory neurons (24 IBSNs and 7 I-NAA) during coughing. All but one (a late-recruited IBSN) discharged a burst of action potentials during the coughing-related phrenic nerve activity. Typically, ramp-like membrane depolarization trajectories and discharge frequencies during coughing were similar to those observed during inspiration. We recorded the activity of 33 DRG inspiratory neurons (23 IBSNs and 10 I-NAA) during swallowing. Most (28/33) neurons were briefly activated, i.e., discharged a burst of action potentials during swallowing, but peak discharge frequency decreased compared with that measured during inspiration. The membrane potentials of nine somata exhibited a brief bell-shaped depolarization during swallowing, the amplitude of which was similar to that observed during inspiration. These results suggest that some inspiratory premotoneurons and propriobulbar neurons of the DRG might be involved in nonrespiratory motor activities, even if clearly antagonistic to breathing (e.g., swallowing). We postulate the existence in the medulla oblongata of adult mammals of neurons exhibiting a "functional flexibility".

Action Potentials↗
PubMed1996

Histopathological grading of response to induction chemotherapy in non-small cell lung cancer: a preliminary study.

Management of locally advanced NSCLC is controversial. Induction chemotherapy followed by surgery has become an accepted approach for Stage III disease. However, the clinical assessment of the efficacy of preoperative treatment is inaccurate. We propose a four-grade histopathological evaluation of the response to chemotherapy based on the analysis of 20 evaluable cases and compared with clinical outcome. Follow-up ranged from 12 to 68 months. Correlation between different grading of necrosis and survival is statistically significant. Based on these preliminary results, we suggest that grading of response is a valid parameter to evaluate standard regimens and novel drug associations in larger trials.

Aged↗
PubMed1996

Synthesis and sulfatase inhibitory activities of non-steroidal estrone sulfatase inhibitors.

About one-third of breast cancers are classified as estrogen-dependent breast cancers. In the past 10 years, numerous reports have suggested the importance of estrone sulfate and estrone sulfatase in regulating the supply of estrogens to these cancers. Estrone sulfatase inhibitors may thus prove to be useful for the treatment of these diseases. Several research groups have reported the development of estrone sulfatase inhibitors, and estrone-3-O-sulfamate has been shown to be the most potent sulfatase inhibitor. However, a recent report indicated that estrone may be released during the inactivation of sulfatase by estrone-3-O-sulfamate and rendered the inhibitor to be estrogenic. Therefore, there is a need for a potent non-steroidal sulfatase inhibitor that is metabolically stable, more selective, and lacking estrogenic activity. We developed a series of (p-O-sulfamoyl)-N-alkanoyl tyramines, and they proved to be potent estrone sulfatase inhibitors. Using human placental microsome as the enzyme source, the best inhibitor in this series, compound 18, has an IC50 of 55.8 nM. Another potent inhibitor in this series, compound 17, exhibited time-dependent inactivation of sulfatase when incubated at various concentrations (0.2-1.0 microM) of the inhibitor. Estrone sulfate partially blocked the inactivation of the enzyme by the compound, indicating that the compound inactivated sulfatase at the active site. The irreversible nature of the enzyme-inhibitor interaction was supported by irreversibility studies. Thus, (p-O-sulfamoyl)-N-alkanoyl tyramines represent a new series of non-steroidal estrone sulfatase inhibitor.

Binding Sites↗
PubMed1996

Ex vivo evidence for PGE2 and LTB4 involvement in cutaneous leishmaniasis: relation with infection status and cytokine production.

Ex vivo culture of spleen cells from BALB/c mice infected with 2 x 10(6) Leishmania major (L. major) promastigotes were cultured with ConcanavalinA (ConA) or leishmanial antigen (L. Ag) and tested for prostaglandin E2 (PGE2) and for leukotriene B4 (LTB4), in order to study their involvement in the evolution of cutaneous leishmaniasis and the connexion with lymphokine-mediated responses. The data were compared with those obtained in BALB/c mice protected against L. major by sublethal irradiation (550 rad; cured mice). In the unprotected BALB/c mice the levels of PGE2 that were responsible for the depression of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF alpha) Th1-associated cytokines and for the relative increase in the interleukin-4 (IL-4) became higher and higher as the lesion progressed. On the contrary, the cured mice produced levels of PGE2 similar to normal uninfected controls, high levels of TNF alpha and IFN-gamma and low levels of IL-4. Elevated levels of LTB4 were detected in the early stage of infection in the unprotected mice compared to cured ones, a sign of more intense inflammation and a stimulus for the recruitment of inflammatory cells. The observation that exogenous LTB4 was able to enhance in vitro both Th1 cytokines in cured mice and Th2 cytokines in unprotected ones suggests that LTB4 could act in the recruitment of the T cells already committed to Th1 or Th2 phenotype.

Animals↗
PubMed1996

Depression of CD4 T cell subsets and alteration in cytokine profile in boutonneuse fever.

Interferon (IFN)-gamma, interleukin (IL)-10, IL-6, and tumor necrosis factor (TNF)-alpha were significantly increased in sera from Sicilian patients with acute boutonneuse fever (BF) compared with those of healthy controls. IFN-gamma levels dropped sharply within the second week after infection. IL-6, IL-10, and TNF-alpha levels gradually declined; in convalescent patients only were they in the normal range. In contrast, peripheral blood mononuclear cells (PBMC) stimulated in vitro with phytohemagglutinin (PHA) produced low levels of IL-10 and IFN-gamma in acute BF that were compatible with the reduction in the levels of CD4+, CD4+/CD45RO+, and CD4+/CD45RA+ cells. In vitro production of TNF-alpha and IL-6 from PBMC stimulated with PHA was not significantly modified during the various phases of the infection compared with control PBMC, which could be due to the persistence of high levels of CD14+ monocytes compensating for the decrease in CD20+ B cells.

Adult↗
PubMed1996

Repeated administration of the 5-HT3 receptor antagonist granisetron reduces the incidence of delayed cisplatin-induced emesis in the piglet.

We analyzed the effects of the 5-HT3 receptor antagonist granisetron on both acute and delayed phases of cisplatin-induced emesis in the conscious piglet. Animals that received a high dose of cisplatin (5.5 mg/kg i.v.) were observed continuously for 60 h. Seventeen piglets were treated with cisplatin only and acted as controls. In experimental animals, granisetron (administered before cisplatin) was administered either as a single initial injection (7 mg/kg), alone or in combination with dexamethasone (40 mg), or as multiple injections (1 mg/kg) given every 5 h during the first 30 h of the experiment (cumulative dose: 7 mg/kg). Two other groups of piglets were treated with dexamethasone (40 mg) alone or with multiple injections of ondansetron (7 injections at 3.5 mg/kg), respectively. The latency to the first emetic episode was significantly increased in all groups that received a 5-HT3 receptor antagonist, whatever the agent and the protocol of administration. Piglets treated solely with dexamethasone exhibited a latency similar to that of controls. The total number of emetic events during the 60 h was significantly reduced only in the group of piglets treated repeatedly with granisetron and in the group that received an initial dose (7 mg/kg) of granisetron in combination with dexamethasone. We observed that 3 out of 8 piglets treated repeatedly with granisetron did not vomit throughout the experiment. These results demonstrate that granisetron, when administered repeatedly, is efficacious against delayed emesis. They also suggest that serotonin may be involved in the production of the delayed phase of cisplatin-induced emesis.

Animals↗
PubMed1996

[Pulsating tumor of the sternum: enlarged exeresis and reconstruction with marlex-methylmethacrylate prosthesis].

The authors report on a rare case of pulsating tumor of the sternum. En bloc resection was carried out with removal of the sternal manubrium and body, tracts of the I-II-III rib with the intercostal muscles and part of the left pectoralis major. Reconstruction of the thoracic wall was performed with a marlex MMA sandwich prosthesis. From a histological viewpoint, the carcinoma was well differentiated and compatible with thyroid primitivity. Non complementary antiblastic therapies were provided as all the examinations carried out were negative and the intervention was radical. The patient had been followed-up with serial controls and three complete stagings at one, three and five years after intervention (CT, echography and function tests of the thyroid, bone scintigraphy). At follow-up of more than six years the patient is doing well and is event free. The authors believe, even with the help of reports from the literature that, in sternal metastases from thyroid carcinomas, especially when single and large, surgical therapy is required.

Carcinoma↗