Biomedical subjects

C Tortorella

Publications and source records attributed to C Tortorella.

At least 19 recordsLinked to original sources

PubMed2003

Cucumber mosaic virus as carrier of a hepatitis C virus-derived epitope.

Cucumber mosaic virus (CMV) is a three component isodiametric plant virus which is common worldwide and has an extremely wide host range. A pseudorecombinant was made, derived from the RNA3 component of the CMV-S strain, carrying the coat protein (CP) gene, and the RNA1,2 components of the CMV-D strain. This system developed mild mosaic and vein clearing in Xanthi tobacco three weeks after inoculation. The CP gene was then engineered in three different positions, to encode a Hepatitis C virus (HCV) epitope. The selected peptide was the so-called R9 mimotope, a synthetic surrogate derived from a consensus profile of many hypervariable region 1 (HVR1) sequences of the putative HCV envelope protein E2. Serum samples from 60 patients with chronic hepatitis C displayed a significant immunoreactivity to crude plant extracts infected with the chimeric CMV. These results suggest that further investigation should be made into a possible vaccine function for the CMV-HCV mimotope system.

Adult↗

PubMed2002

Course and prognosis in early-onset MS: comparison with adult-onset forms.

OBJECTIVES: To establish the prognostic role of clinical and demographic factors in a hospital-based cohort of MS patients categorized by age at clinical onset and clinical course. METHODS: Eighty-three patients with MS had a clinical onset of the disease in childhood (age <16 years; early-onset MS [EOMS]) and 710 in adult age (between 16 and 65 years; adult-onset MS [AOMS]). Patients were followed for a mean period of observation of 5 years. Univariate and multivariate analyses of clinical and demographic predictors for rapid progression and disability were performed using a stepwise Cox regression model with time-dependent covariates. RESULTS: In EOMS, the Expanded Disability Status Scale (EDSS) evaluated at last clinical examination was lower than in AOMS, despite a longer disease duration. The probability to reach growth disability and progression was significantly lower in EOMS than in AOMS. Median times to reach EDSS score of 4 and secondary progression were longer in EOMS than in AOMS, but the age at both endpoints was significantly lower in EOMS. In EOMS and AOMS, an irreversible disability was related to a secondary progressive course, a sphincteric system involvement at onset, and an older age at onset (in EOMS only for the group >14 years); in AOMS, other unfavorable factors were a pyramidal involvement at onset and a high relapse frequency in the first 2 years. The risk of entering secondary progression was significantly influenced by a high number of relapses in EOMS and by a higher age at onset and a short interattack interval in AOMS. CONCLUSION: A slower rate of progression of disease characterized EOMS patients, suggesting more plasticity to recover in developing CNS, but the early clinical manifestation cannot be considered a positive prognostic factor.

Adolescent↗

PubMed2001

Axonal damage in multiple sclerosis plaques: a combined magnetic resonance imaging and 1H-magnetic resonance spectroscopy study.

The purpose of this study was to compare magnetic resonance imaging (MRI) features and proton MR spectroscopy (1H-MRS) patterns of multiple sclerosis (MS) plaques in order to define the metabolic substrate in different lesion subtypes. Combined MRI and single-voxel 1H-MRS investigation was performed in 54 MS patients (47 relapsing remitting (RR) and seven secondary progressive (SP)). Sixty-seven MS lesions were selected. Thirty-seven lesions were Gadolinium (Gd) enhancing (nine isointense and 28 hypointense on pre-contrast T(1)-weighted scans) and 30 Gd unenhancing (six isointense and 24 hypointense on pre- and post-contrast T(1)-weighted scans). Choline (Cho), creatine (Cr), N-acetyl aspartate (NAA) and lactate were evaluated in 1H spectra acquired from MS plaques and from normal white matter (NWM) of 22 neurological controls. MS lesions of RR patients were characterized by a significant increase of Cho/Cr and decrease of NAA/Cr and NAA/Cho ratios. No significant metabolite changes were found in lesions of SP patients. Gd enhancing plaques showed lactate signal with higher frequency (37.8%) than Gd unenhancing plaques (16.7%) (p=0.04). A significant increase of Cho/Cr was found in Gd enhancing lesions when compared to controls (p<0.01), and to Gd unenhancing lesions (p<0.05). In particular, there was evidence of a significant increase of Cho/Cr in pre-contrast T(1) hypointense Gd enhancing lesions (p<0.01 vs. controls). The Gd unenhancing lesions (p<0.01), in particular the T(1) hypointense group (p<0.05), showed a significant decrease of NAA/Cr only when compared to controls. These data confirm that in vivo MRS indicates key pathological features of MS plaques. The increased Cho/Cr ratio found in Gd-enhancing plaques, in particular in the T(1) hypointense lesions, may reflect increased membrane cell turnover. The T(1) hypointense Gd unenhancing plaques better reflect axonal damage, as suggested by the decrease of NAA/Cr. Nevertheless, the lack of statistical differences in NAA/Cr between plaque subgroups suggests that axonal impairment might occur even in the early stages.

Adolescent↗

PubMed2001

Proton MR spectroscopy in idiopathic spasmodic torticollis.

Single-voxel proton magnetic resonance spectroscopy (1H-MRS), localised to the basal ganglia, was used to determine changes in metabolite levels in idiopathic spasmodic torticollis (IST). We examined nine patients and 13 healthy subjects. The mean values (+/- SD) of peak area ratios were: IST: N-acetyl-aspartate (NAA)/choline-containing compounds (Cho) 1.79 +/- 0.39, NAA/creatine and phosphocreatine compounds (Cr) 1.61 +/- 0.38, Cho/Cr 0.91 +/- 0.19; controls: NAA/Cho 2.07 +/- 0.35, NAA/ Cr 1.82 +/- 0.31, Cho/Cr 0.89 +/- 0.12. Statistical analysis showed that NAA/Cho and NAA/Cr were significantly lower in patients than in controls (P = 0.0304 and 0.0431, respectively). These results indicate a reduction in NAA, and suggest striatal involvement in the pathogenesis IST.

Adolescent↗

PubMed2001

Endothelins stimulate aldosterone secretion from dispersed rat adrenal zona glomerulosa cells, acting through ETB receptors coupled with the phospholipase C-dependent signaling pathway.

Compelling evidence indicates that endothelins (ETs) stimulates aldosterone secretion from rat zona glomerulosa (ZG) cells, acting through the ETB receptor subtype. We have investigated the mechanisms transducing the aldosterone secretagogue signal elicited by the pure activation of ETB receptors. Aldosterone response of dispersed rat ZG cells to the selective ETB-receptor agonist BQ-3020 was not affected by inhibitors of adenylate cyclase/protein kinase (PK)A, tyrosine kinase-, mitogen-activated PK-, cyclooxygenase- and lipoxygenase-dependent pathways. In contrast, the inhibitor of phospholipase C (PLC) U-73122 abrogated, and the inhibitors of PKC, phosphatidylinositol trisphosphate (IP(3))-kinase and calmodulin (calphostin-C, wortmannin and W-7, respectively) partially prevented aldosterone response to BQ-3020. When added together, calphostin-C and wortmannin or W-7 abolished the secretagogue effect of BQ-3020. BQ-3020 elicited a marked increase in the intracellular Ca2+ concentration ([Ca2+]i) in dispersed rat ZG cells, and the effect was abolished by the Ca(2+)-release inhibitor dantrolene. The Ca2+ channel blocker nifedipine affected neither aldosterone nor Ca2+ response to BQ-3020. Collectively, our findings suggest that (1) ETs stimulate aldosterone secretion from rat ZG cells through the activation of PLC-coupled ETB receptors; (2) PLC stimulation leads to the activation of PKC and to the rise in [Ca2+]i with the ensuing activation of calmodulin; and (3) the increase in [Ca2+] is exclusively dependent on the stimulation of IP(3)-dependent Ca2+ release from intracellular stores.

Aldosterone↗

PubMed2001

Neutrophil oxidative metabolism in aged humans: a perspective.

During the last few years, several studies have pointed out the imbalance of immune responses with advancing age, this accounting for the increased susceptibility of elderly individuals to life-threatening diseases. This review is focussed on the role of neutrophil respiratory burst in the age-associated decline of cytotoxicity towards invading microorganisms. Particular emphysys is given to extracellular matrix proteins, acting as physiologic regulators of oxidative activity, as well as to neutrophil cytoskeleton, whose dysfunction is likely to be involved in the agonist-related defect of the coupling between beta2-dependent adhesive and oxidative events occurring in the aging. The role of oxidative metabolism in the increased incidence of apoptotic phenomena observed in neutrophils of aged following cell stimulation is also discussed.

Aged↗

PubMed2001

Interleukin-12 p40/p70 ratio and in vivo responsiveness to IFN-alpha treatment in chronic hepatitis C.

To evaluate the relationship between cytokine balance and responsiveness to interferon-alpha (IFN-alpha), we investigated the production of IFN-gamma, interleukin-10 (IL-10), IL-12 p70, and IL-12 p40 by peripheral blood mononuclear cell (PBMC) cultures from patients with chronic hepatitis C (CHC) before and after 1 year of IFN-alpha treatment. Before the therapy, responder (R) patients exhibited lower IFN-gamma release, higher IL-10 production, and higher values of the IL12 p40/p70 ratio compared with nonresponders (NR). Increased sensitivity to the effects of IL-12 and IL-10, as well as higher IL-12-dependent IFN-gamma secretion, were also found in the R subset. After IFN-alpha therapy, an increase in IFN-gamma production and a decrease in the IL-12 p40/p70 ratio were observed in R patients, whereas opposite results were obtained in the NR group. Finally, the therapy induced downregulation of IL-10 production and cell responsiveness to recombinant IL-12 in all patients. These findings imply that predominance of a T helper 2 (Th2) cytokine profile in CHC patients favors the beneficial effects of IFN-alpha, thus suggesting a therapeutic role for Th1-driven stimulation of immune response. The findings also stress the primary importance of the IL-12 p40 and p70 balance in the modulation of immune responses to hepatitis C virus (HCV).

Adult↗

PubMed2001

Cholecystokinin stimulates aldosterone secretion from dispersed rat zona glomerulosa cells, acting through cholecystokinin receptors 1 and 2 coupled with the adenylate cyclase-dependent cascade.

Cholecystokinin is a regulatory peptide, that acts through two subtypes of receptors, 1 and 2. RT-PCR demonstrated the expression of both cholecystokinin receptors 1 and 2 genes in the zona glomerulosa, but not the zona fasciculata-reticularis, of rat adrenals. Autoradiography demonstrated the presence of abundant [(125)I]cholecystokinin-binding sites in the zona glomerulosa, but not the zona fasciculata-reticularis, which were displaced by both cholecystokinin receptor 1- and 2-selective antagonists (cholecystokinin 1-A and 2-A). Cholecystokinin increased basal aldosterone secretion from dispersed zona glomerulosa cells without affecting corticosterone secretion from zona fasciculata-reticularis cells. The aldosterone response to cholecystokinin was blunted by cholecystokinin 1-A and 2-A, which when added together abolished it. ACTH-stimulated aldosterone production was not affected by cholecystokinin; in contrast, cholecystokinin potentiated aldosterone response to both angiotensin II and K(+). Cholecystokinin enhanced cAMP, but not IP(3), release by dispersed zona glomerulosa cells. The aldosterone response to cholecystokinin was abolished by the adenylate cyclase inhibitor SQ-22536 and the PKA inhibitor H-89, but not by either the PLC inhibitor U-73122 or the PKC inhibitor calphostin C. In conclusion, our study provides evidence that cholecystokinin, acting through cholecystokinin receptors 1 and 2 coupled with the adenylate cyclase/PKA cascade, exerts a sizeable secretagogue action on rat zona glomerulosa cells.

Adenylyl Cyclases↗

PubMed2001

Signaling pathways involved in the A and B receptor-mediated cortisol secretagogue effect of endothelins in the human adrenal cortex.

Endothelins (ETs) are a family of 21-amino acid hypertensive peptides, which together with their receptors ETA and ETB are expressed in human adrenal cortex. Evidence has been provided that ETs exert a potent secretagogue effect on human adrenocortical cells, acting through both ETA and ETB receptors. Therefore, it seemed worthwhile to study the signaling cascades mediating the cortisol secretagogue effect of the two receptor subtypes. Normal adrenal glands were obtained from consenting patients undergoing unilateral nephrectomy with ipsilateral adrenalectomy for renal cancer. Dispersed zona fasciculata-reticularis (ZF/R) cells were obtained by collagenase digestion and mechanical disaggregation. The selective activation of ETA and ETB receptors was obtained by exposing dispersed cells to ET-1 plus the ETB receptor antagonist BQ-788 and to the selective ETB receptor agonist BQ-3020, respectively. ETA and ETB receptors about equally contributed to the cortisol response of dispersed ZF/R cells to ETs. The phospholipase (PL) C inhibitor U-73122 abolished ETA-mediated secretory response, but only partially prevented the ETB-mediated one. The phosphatidylinositol 3-kinase inhibitor wortmannin and the protein kinase (PK) C inhibitor calphostin-C significantly blunted the secretory responses ensuing from the activation of both receptor subtypes, while the Ca(2+)-channel blocker nifedipine was ineffective. The ETB receptor-, but not the ETA receptor-mediated cortisol response was partially reversed by the cyclooxygenase (COX) inhibitor indomethacin, which when added together with U-73122 abolished it. The inhibitors of adenylate cyclase, PKA, tyrosine kinase and lipoxygenase did not affect the secretory response to the activation of either receptor subtype. ETA-receptor activation raised inositol triphosphate (IP3) production from dispersed ZF/R cells, while ETB-receptor stimulation enhanced both IP3 and prostaglandin-E(2) production. Collectively, our findings indicate that ETs stimulate cortisol secretion from human ZF/R cells, acting through ETA receptors exclusively coupled with PLC/PKC-dependent pathway and ETB receptors coupled with both PLC/PKC- and COX-dependent cascades.

Adenine↗

PubMed2001

Calcitonin gene-related peptide (CGRP), acting via CGRP type 1 receptors, inhibits potassium-stimulated aldosterone secretion and enhances basal catecholamine secretion from rat adrenal gland.

Calcitonin gene-related peptide (CGRP) is a potent hypotensive peptide, that acts via two main subtypes of receptors, named CGRP1 and CGRP2. CGRP belongs to a regulatory-peptide family, that includes adrenomedullin (ADM) whose aldosterone antisecretagogue and catecholamine secretagogue actions are well demonstrated. Quantitative autoradiography showed the presence of [125I]CGRP binding sites in both rat adrenal zona glomerulosa (ZG) and medulla. Binding was displaced by the CGRP1-receptor antagonist CGRP(8-37), but not by the CGRP2-receptor agonist [cys(Et)2,7]-alphaCGRP (CGRP2-A). CGRP concentration-dependently inhibited 10 mM-stimulated (but not basal) aldosterone secretion from dispersed rat ZG cells, and enhanced basal catecholamine secretion from rat adrenomedullary fragments. The responses to the maximal effective concentration of CGRP (10-8 M) were blocked by 10-7 M CGRP(8-37). CGRP2-A (10-7 M) neither altered aldosterone response to 10 mM K+ nor enhanced basal catecholamine secretion. The conclusion is drawn that CGRP, like ADM, inhibits agonist-stimulated aldosterone secretion and stimulates basal catecholamine release in the rat, exclusively acting via CGRP1 receptors.

Adrenal Glands↗

PubMed2001

Neutrophil apoptotic cell death: does it contribute to the increased infectious risk in aging?

During the last few years, several studies have pointed out the imbalance of immune response with advancing age, which accounts for the increased susceptibility of elderly individuals to life-threatening diseases. This review is focused on the role of neutrophil apoptosis in the age-associated decline of cytotoxicity towards invading micro-organisms. The results indicate that the overall intrinsic mechanisms regulating neutrophil cell death are unaffected by age. Neutrophils from aged humans exhibit a diminished ability to be rescued by proinflammatory mediators, as well as a weak buffer capacity towards proapoptotic reactive oxygen species (ROS) generated during cell stimulation. Such events may hamper in vivo the accumulation of functionally active cells in inflammatory areas, thus contributing to the increased infection-related risk of morbidity and mortality with advanced age. The impact of these new findings in terms of therapeutic applications is discussed.

Aging↗

PubMed2001

Cladribine. Ortho Biotech Inc.

Cladribine, an adenosine deaminase inhibitor, has been developed and launched by Ortho Biotech in collaboration with The Scripps Research Institute for the treatment of several neoplasms, including acute myelogenous leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, cutaneos T-cell lymphoma, hairy-cell leukemia and non-Hodgkin's lymphoma. It was first launched in the US in February 1993. Ortho Biotech and The Scripps Research Institute have since been developing the compound for its potential use in multiple sclerosis (MS). In 1997, Ortho filed air NDA in the US for the use of cladribine in the treatment of relapsing-remitting and secondary progressive MS. An FDA drug advisory committee was planning to meet in January 1999 to discuss the NDA. However, Ortho cancelled the meeting. Following an FDA inspection during December 1998 and January 1999, the Scripps Clinic received a warning letter from the FDA in April 1999 regarding violations in the clinical studies of cladribine for MS, and Ortho withdrew the NDA after concluding that further clinical studies would be necessary. Cladribine has been known since the 1960s as an intermediate for the synthesis of 2-deoxynucleotides and its potential for the treatment of leukemia was disclosed in 1984. The Scripps Research Institute and the Johnson & Johnson group hold several patents claiming preparation methods (US 05208327), and additional indications, such as multiple sclerosis (WO-09316706) and rheumatoid arthritis (US-05310732). The associated patent, WO-09323508, is the only one among those patents that claims the use of unmodified cladribine for the treatment of leukemia, but it focuses particularly on a specific form of the disease, chronic myelogenous leukemia. Analysts at UBS Warburg predicted in October 2001, that the product would make US sales of $50 million in 2004 for its MS indication.

Adenosine Deaminase Inhibitors↗

PubMed2000

Regulatory role of extracellular matrix proteins in neutrophil respiratory burst during aging.

Neutrophil respiratory burst was assessed on plates coated with fibronectin (FN) or laminin (LM), both used at dosages inhibiting polystyrene-triggered cell activation in young healthy volunteers. Under these conditions, a low, yet significant, spontaneous superoxide anion (O(2)(-)) production, matching with enhanced levels of basal adherence, was detected in FN-plated neutrophils of elderly donors. In contrast, although neutrophil stimulation with tumor necrosis factor (TNF)-alpha, granulocyte macrophage-colony stimulating factor (GM-CSF), fMLP or phorbol myristate acetate (PMA) gave rise to a massive and prolonged FN-primed O(2)(-) release, a significant impairment of oxidative response occurred in the aged group as a result of GM-CSF or fMLP cell challenge. Such an effect was not associated to an age-related imbalance of stimulant-triggered neutrophil adhesiveness to FN, even though a larger contribution of CD18-dependent versus CD18-independent pathways was observed in old as compared to young individuals. Notably, within the aged group, anti-CD18 monoclonal antibody cell pretreatment resulted in a higher suppression of FN-primed O(2)(-) release following TNF-alpha with respect to GM-CSF stimulation, thus implying that an agonist-related defect of the coupling between beta2 integrin-dependent adhesive and oxidative events is likely to occur as a feature of age. All physiological mediators failed to activate the respiratory burst of neutrophils plated on LM-coated wells in both young and aged donors. This effect appears to be the result of an active process, since neutrophils from either group of subjects adhered to LM-coated surfaces and LM inhibited in a dose-dependent manner the FN-priming effect on neutrophil O(2)(-) production. All together the findings provide additional evidence for an imbalance of neutrophil-mediated functions in the elderly.

Aged↗

PubMed2000

A magnetization transfer histogram study of normal-appearing brain tissue in MS.

OBJECTIVE: To evaluate 1) the ability of magnetization transfer ratio (MTR) histogram analysis to detect the extent of changes occurring outside MS lesions seen on conventional scans, 2) whether such changes vary in the different MS clinical phenotypes, 3) whether the changes are associated with the extent and severity of the macroscopic lesion load, and 4) the contribution to brain atrophy. METHODS: Dual-echo, T1-weighted, and MT scans of the brain were obtained from 77 patients with varying MS courses and 20 age- and sex-matched control subjects. To create MT histograms of the normal-appearing cerebral tissue, MS lesions were segmented from dual-echo scans, superimposed automatically, and nulled out from the coregistered and scalp-stripped MTR maps. Average MTR, peak height, and peak position were considered. T2 and T1 lesion loads, average lesion MTR, and brain volume were also measured. RESULTS: Average histogram MTR (p<0.0001) and peak position (p<0.0001) from patients with relapsing-remitting MS (RMMS) were lower than those from control subjects. Patients with primary progressive MS (PPMS) had lower average histogram MTR (p = 0.002) and histogram peak height (p = 0.01) than control subjects. Patients with secondary progressive MS (SPMS) had a lower peak height (p = 0.05) than those with RRMS. Average lesion MTR (p<0.0001) correlated highly with the histogram MTR. Average histogram MTR (p<0.0001) and T2 lesion load (p = 0.001) correlated highly with brain volume. CONCLUSIONS: The amount of microscopic changes account for an important fraction of the lesion load in MS. They may contribute to the development of brain atrophy and tend to be more evident in patients with secondary progressive MS.

Adult↗

PubMed2000

Transforming growth factor beta1 and soluble Fas serum levels in hepatocellular carcinoma.

In this study we assessed the usefulness of serum Transforming Growth Factor-beta1 (TGF-beta1) and soluble Fas (sFas) in distinguishing liver cirrhosis (LC) with and without hepatocellular carcinoma (HCC) as compared with alpha-fetoprotein (AFP). Serum TGF-beta1 and sFas levels were measured by ELISA in 51 LC patients, 54 patients with HCC and 30 healthy donors. Considering as a cut-off limit (mean+1SD of controls) 74 pg/ml and 637 pg/ml for TGF-beta1 and sFas, respectively, we computed serum concentrations of TGF-beta1 and sFas as a score (mean+/-SD). The positive frequency of serum TGF-beta1 levels in HCC patients (54%) was greater than in LC patients (26%) and healthy donors (3%). TGF-beta1 levels were higher in HCC (1.6+/-0.5) than in LC (1.1+/-0.2) (P<0.0001) and healthy donors (0.6+/-0.2). Using a cut-off limit of 82 pg/ml (mean+2SD), the positive frequency of TGF-beta1 was 20% in HCC patients. None of the controls and LC patients had TGF-beta1 levels higher than 82 pg/ml. The positive frequency of serum sFas levels was 100% in HCC patients, 98% in LC patients and 3% in healthy controls. Serum sFas levels were higher in HCC (2.5+/-0.7) than in LC (1.9+/-0.5) (P<0. 001) and healthy donors (0.6+/-0.3). No significant change of positive frequency was obtained by setting sFas cut-off at higher levels. sFas values did not correlate with TGF-beta1 levels. No relationship was found between TGF-beta1 amounts and AFP levels. However, in the 23% of HCC patients, with normal AFP values TGF-beta1 levels were higher than the cut off. These findings suggest the potential usefulness for TGF-beta1 assay in AFP-negative HCC.

Adult↗

PubMed2000

Early onset multiple sclerosis.

Multiple sclerosis (MS) onset is usually in adult life (age 20-40 years). Discordant data have been reported concerning the frequency of early onset MS (EOMS) that ranges from 2.7% to 5%, whereas there is a general agreement on prevalence of female sex, particularly after puberty. The initial symptoms in EOMS are frequently characterized by visual loss whereas the other functional systems are involved with a variable frequency. Literature data show that EOMS tends to have a relapsing-remitting course, a high rate of recovery from the initial attack, a long time interval between the first and second attacks and a slow progression rate. A poor prognosis is reported in a few cases of EOMS and seems to be related to number of relapses and to the delay between the first and second attacks.

Adolescent↗

PubMed2000

Evidence for a paracrine role of adrenomedullin in the physiological resetting of aldosterone secretion by rat adrenal zona glomerulosa.

Adrenomedullin (ADM) has been recently found to directly inhibit agonist-stimulated aldosterone secretion by dispersed zona glomerulosa (ZG) cells and to stimulate basal catecholamine release by adrenomedullary fragments. In light of the fact that catecholamines enhance aldosterone secretion acting in a paracrine manner, we have investigated whether these two effects of ADM may interact when the integrity of the adrenal gland is preserved. ADM increased basal aldosterone output by adrenal slices containing a core of adrenal medulla, and the effect was blocked by the beta-adrenoceptor antagonist l-alprenolol. In contrast, ADM evoked a moderate inhibition of K(+)-stimulated aldosterone production, and the blockade was complete in the presence of l-alprenolol. The in vivo bolus injection of ADM did not affect plasma aldosterone concentration (PAC) in rats under basal conditions. Conversely, when rat ZG secretory function was enhanced (by sodium restriction or infusion with angiotensin-II [ANG-II]) or depressed (by sodium loading or infusion with the angiotensin-converting enzyme inhibitor captopril), ADM evoked a sizeable decrease or increase in PAC, respectively. The prolonged infusion with the ADM receptor antagonist ADM(22-52) caused a further enhancement of PAC in sodium-restricted or ANG-II-treated rats, and a further moderate decrease of it in sodium-loaded or captopril-administered animals. RIA showed that ADM plasma concentration did not exceed a concentration of 10(-11) M in any group of animals. Under basal conditions, ADM adrenal content was 1.2-2.0 pmol/g, which may give rise to local concentrations higher than 10(-8) M (i.e. well above the minimal effective ones in vitro). ADM adrenal concentration was markedly increased (from two-fold to three-fold) by both ZG stimulatory and suppressive treatments. Collectively, our findings suggest that in vivo 1) ADM, in addition to directly inhibit aldosterone secretion, may enhance it indirectly by eliciting catecholamine release, the two actions annulling each other under basal conditions; 2) under conditions leading to enhanced aldosterone secretion, the direct inhibitory effect of ADM prevails over the indirect stimulatory one, and the reverse occurs when aldosterone secretion is decreased; and 3) the modulatory action of ADM on the aldosterone secretion has a physiological relevance, endogenous ADM being locally synthesized in adrenals.

Adrenomedullin↗

PubMed2000

Relationship between interferon-gamma, interleukin-10, and interleukin-12 production in chronic hepatitis C and in vitro effects of interferon-alpha.

In the current study, increased interferon (IFN)-gamma, interleukin (IL)-10, and IL-12 p40 serum levels were observed in patients with chronic hepatitis C (CHC) compared to controls. Patients also displayed an increased spontaneous IFN-gamma release but a deficient peripheral blood mononuclear cells (PBMC) IFN-gamma production following stimulation with Staphylococcus aureus Cowan I strain (SAC). No difference was found with reference to spontaneous or phytohaemagglutinin (PHA)-induced IL-10 release between patients and controls, whereas a higher IL-12 p70 and IL-12 p40 secretion triggered by SAC was observed in patients. Moreover, IL-12 p40/p70 ratio following SAC stimulation was higher in patients compared to controls and a negative correlation was found between this ratio and IFN-gamma amounts. Recombinant IL-12 (rIL-12) as well as neutralizing anti-IL-10 monoclonal antibodies (mAbs) were able to restore the compromised IFN-gamma production. Of note, anti-IL-10 supplementation induced a lower IL-12 p40/p70 ratio in HCV subjects as compared to controls. Finally, IFN-alpha upregulated in vitro IFN-gamma, IL-10, and IL-12 p70 release but not IL-12 p40 secretion, this giving rise to a normalization of IL-12 p40/p70 ratio. The data suggest the occurrence of an enhanced responsiveness to IL-10 modulating effects, likely mediated by an imbalance of IL-12 p40/p70 ratio, in chronic HCV infection. Cytokine balance restoration might thus contribute to achieve therapeutical results in chronic hepatitis C.

Adult↗