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Claudio De Simone

Publications and source records attributed to Claudio De Simone.

36 records · Page 2Linked to original sources
PubMed2004

DNA from probiotic bacteria modulates murine and human epithelial and immune function.

BACKGROUND & AIMS: The intestinal epithelium must discriminate between pathogenic and nonpathogenic bacteria and respond accordingly. The aim of this study was to examine whether bacterial DNA can serve as the molecular basis for bacterial recognition. METHODS: HT-29 monolayers were treated with various bacterial DNA and interleukin (IL)-8 secretion measured by enzyme-linked immunosorbent assay, nuclear factor kappaB activation by electrophoretic mobility shift assay and reporter assays, and IkappaB levels by Western blotting. Cytokine secretion in response to bacterial DNA was measured in murine colonic segments and splenocytes. IL-10-deficient mice were fed DNA from VSL probiotic compound daily for 2 weeks. Colons were removed and analyzed for cytokine production and inflammation. RESULTS: HT-29 cells responded with IL-8 secretion to bacterial DNA in a differential manner. In the presence of proinflammatory stimuli, VSL3 DNA inhibited IL-8 secretion, reduced p38 mitogen-activated protein kinase activation, delayed nuclear factor kappaB activation, stabilized levels of IkappaB, and inhibited proteasome function. VSL3 DNA inhibited colonic interferon (IFN)-gamma secretion in mouse colons and also attenuated a Bacteroides vulgatus-induced IFN-gamma release from murine splenocytes. In mice, VSL3 DNA attenuated a systemic release of tumor necrosis factor alpha in response to Escherichia coli DNA injection. Treatment of IL-10-deficient mice with oral VSL3 DNA resulted in a reduction in mucosal secretion of tumor necrosis factor alpha and IFN-gamma and an improvement in histologic disease. CONCLUSIONS: DNA from probiotic bacteria can limit epithelial proinflammatory responses in vivo and in vitro. Systemic and oral administration of VSL3 DNA ameliorates inflammatory responses.

Animals↗
PubMed2004

Probiotics inhibit nuclear factor-kappaB and induce heat shock proteins in colonic epithelial cells through proteasome inhibition.

BACKGROUND AND AIMS: The extent and severity of mucosal injury in inflammatory bowel diseases are determined by the disequilibrium between 2 opposing processes: reparative and cytoprotective mechanisms vs. inflammation-induced injury. Probiotics may provide clinical benefit by ameliorating colitis; however, their mechanisms of action remain largely unknown. Our objective was to investigate microbial-epithelial interactions that could explain the beneficial therapeutic effects of probiotics. METHODS: The effect of VSL#3-conditioned media on the nuclear factor-kappaB pathway in young adult mouse colonic epithelial cells was assessed by using monocyte chemoattractant protein-1 enzyme-linked immunosorbent assays; IkappaBalpha, IkappaBbeta, and p105 immunoblot analysis; and nuclear factor-kappaB luciferase reporter gene and proteasome assays. Effects on heat shock proteins were determined by electrophoretic mobility shift assay and immunoblot for heat shock proteins 25 and 72 in young adult mouse colonic cells. Cytoprotection against oxidant injury was determined by chromium 51 release and filamentous and globular actin assays. RESULTS: VSL#3 produces soluble factors that inhibit the chymotrypsin-like activity of the proteasome in gut epithelial cells. Proteasome inhibition is an early event that begins almost immediately after exposure of the epithelial cells to the probiotic-conditioned media. In addition, these bacteria inhibit the proinflammatory nuclear factor-kappaB pathway through a mechanism different from the type III secretory mechanisms described for other nonpathogenic enteric flora. They also induce the expression of cytoprotective heat shock proteins in intestinal epithelial cells. CONCLUSIONS: The resulting inhibition of nuclear factor-kappaB and increased expression of heat shock proteins may account for the anti-inflammatory and cytoprotective effects reported for probiotics and may be a novel mechanism of microbial-epithelial interaction. These effects seem to be mediated through the common unifying mechanism of proteasome inhibition.

Acetylcysteine↗
PubMed2004

Carnitines and its congeners: a metabolic pathway to the regulation of immune response and inflammation.

Carnitine and its congeners may regulate the immune networks, and their influence on functions of immune cells predominantly or exclusively relies on carnitine-dependent energy production from fatty acids. A reduced pool of carnitines has been demonstrated in either serum or tissues, or both, from patients with a wide spectrum of disorders characterized by unregulated or impaired immune responses ranging from sepsis syndrome to systemic sclerosis, infection with human immunodeficiency virus, and chronic fatigue syndrome. Furthermore, experimental studies have consistently reported that the deranged immune responses and the less efficient inflammation towards infectious organisms associated with aging may be enhanced or modulated by treatment with carnitines. There is also evidence that carnitine deprivation could adversely affect the course of the sepsis syndrome, at least in experimental models, and preliminary studies suggest that carnitine deficiency is ultimately implicated in the pathophysiology of endotoxin-mediated multiple organ failure. Several data indicate that carnitine deficiency is a contributing factor to the progression of infection with human immunodeficiency virus, and carnitine therapy in those patients could counteract the unregulated process of lymphocyte apoptosis and improve CD4 counts. Some case reports have suggested the use of carnitine for the treatment of the severe lactic acidosis that complicates in some patients the use of reverse transcriptase inhibitors.

Animals↗
PubMed2003

Kikuchi Fujimoto lymphadenitis: case report and literature review.

We describe a young woman with two severe episodes of Kikuchi Fujimoto disease occurring 16 years apart. Both episodes were proven by biopsy, and on the second occasion the patient remained dependent on high-dose prednisone for more than 6 months in order to control inflammation and achieve a reduction in cervical lymph node size. The second lymph node biopsy showed leukocytoclastic vasculitis in addition to the typical features of Kikuchi Fujimoto disease, but, even though the clinical interpretation of this finding was unclear, we documented no clinical or laboratory evidence of the development of other serious systemic disease over 20 years of follow-up. Kikuchi Fujimoto disease is considered a disorder with a self-limited course and a favorable outcome. However, on the basis of our experience with this patient and data from peer-reviewed literature, we suggest that this generally accepted postulate should be revised.

Adult↗
PubMed2003

Jaundice and the sepsis syndrome: a neglected link.

The relationship between the sepsis syndrome and the development of jaundice is intriguing, with jaundice having been described as the presenting sign of septicaemia in very few cases. We describe a patient who developed a deep jaundice with conjugated hyperbilirubinaemia caused by Staphylococcus aureus during the early course of septicaemia, when no other sign of the sepsis syndrome could be recognised. It is generally accepted that a mild jaundice may complicate the course of the sepsis syndrome, but it is most unusual to observe such a protracted phase of jaundice before the emergence of other specific clinical signs and laboratory abnormalities. Clinicians should be aware of this presentation of the sepsis syndrome in order to avoid a potentially harmful delay in diagnosis and treatment.

Journal Article↗
PubMed2003

Effect of the lactic acid bacterium Streptococcus thermophilus on stratum corneum ceramide levels and signs and symptoms of atopic dermatitis patients.

A reduced amount of total ceramides could be responsible for functional abnormalities of the skin of atopic dermatitis (AD) patients. The ability of an experimental cream containing sonicated Streptococcus thermophilus to increase skin ceramide levels in healthy subjects has been previously reported. The aim of the present work was to investigate the effects of the topical administration of a S. thermophilus-containing cream on ceramide levels of stratum corneum from AD patients. A 2-week application of the cream, containing a sonicated preparation of the lactic acid bacterium S. thermophilus, in the forearm skin of 11 patients led to a significant and relevant increase of skin ceramide amounts, which could have resulted from the sphingomyelin hydrolysis through the bacterial sphingomyelinase. Moreover, in all patients the topical application of our experimental cream also resulted in the improvement of the signs and symptoms characteristic of AD skin (i.e. erythema, scaling, pruritus).

Administration, Topical↗
PubMed2003

Probiotic lactobacilli: a new perspective for the treatment of inflammatory bowel disease.

Inflammatory bowel disease, such as ulcerative colitis and Crohn's disease, results from an interaction between susceptibility genes, the host's bacterial environment, gut barrier defects, and immunological factors. New management approaches have been evolved from advances in our understanding of the pathobiology of this common gut disorder In particular, the therapeutic manipulation of the bacterial microenvironment in the gut seems to offer an innovative tool for the treatment of those patients. Since the gut is a highly sensitizing organ that contributes to the systemic immune response, potent treatments need to be developed to reduce gut inflammation in this disorder. Recent studies have demonstrated that probiotic lactobacilli, and also immunostimulatory DNA sequences from those same bacteria have an important anti-inflammatory potential in this context. Future research should better define among patients with inflammatory bowel disease the various clinical phenotypes with the greatest potential of response to probiotic treatment. Identification of the genes leading to the disease and a rather better understanding of the underlying immunoregulatory abnormalities will be crucial steps to define the different profiles of interaction between endogenous digestive bacterial flora and the immune system in each individual patient. Such advances will probably lead to targeting of effective treatments, including bacteriotherapy with probiotic lactobacilli, to subsets of patients with inflammatory bowel disease.

Animals↗
PubMed2002

Modulation of apoptosis and improved redox metabolism with the use of a new antioxidant formula.

Oxidative stress is involved in the pathogenesis of a wide spectrum of diseases, implicating that strategies directed at counterbalancing oxidative processes could have a role in clinical medicine. There is also an evidence that oxidative stress acts as a major determinant of apoptotic cell death. Many studies have reported favourable effects of antioxidant formulas on several parameters of the oxidant-antioxidant balance, but none of them has focused whether antioxidant formulas could modulate apoptosis. We investigated in 20 healthy individuals the effect of supplementation with a formula containing alpha-tocopherol, alpha-lipoic acid, coenzyme Q(10), carnitines, and selenomethionine, on plasma oxidant status and peroxide levels, erythrocyte antioxidant enzymes, lymphocyte apoptosis, and generation of ROS at the mitochondrial level. Control subjects received only carnitines or an incomplete formula with alpha-tocopherol, alpha-lipoic acid, coenzyme Q(10), and selenomethionine. Supplementation with the complete formula resulted in a significant increase in the plasma antioxidant status that was mirrored by a decrease in blood peroxide levels and a reduced generation of ROS at the mitochondrial level. This was associated with a significant decrease in the frequency of peripheral blood lymphocytes, with either CD4 or CD8 phenotype, undergoing apoptosis. Less consistent results were found when either incomplete formula was used. Our study suggests that supplementation with antioxidant formulas can modulate the process of apoptosis under in vivo conditions. The clinical potential of this strategy in the treatment of diseases with an elevated commitment to apoptosis should be explored.

Adult↗
PubMed2002

Carboxymethylcellulose improves the antimutagenic activity of sodium selenite against maleic hydrazide in Vicia faba seedlings.

In this study the genotoxic effects induced by a treatment with different doses of sodium selenite in Vicia faba seedlings were evaluated with or without the addition of carboxymethylcellulose. A further objective of this study was to verify whether the adduct selenite-carboxymethylcellulose was also able to reduce the genotoxic damages induced by the herbicide maleic hydrazide, a strong mutagenic agent in plants, at a higher extent than selenite alone. The results obtained showed a genotoxic activity of sodium selenite at concentrations up to 8.6 mg L-1. In the treatments with selenite-carboxymethylcellulose, the genotoxicity induced by the complex was significantly lower in comparison to how much was observed in the treatment with selenite only. When sodium selenite's protective activity against the genotoxic effects induced by the herbicide maleic hydrazide was tested, a reduction of mutagenic damages was observed at the highest application doses of selenite (from 86 mg L-1). The treatments with selenite-carboxymethylcellulose resulted in a further increase of selenium protective activity, which was observable for all doses used. These findings suggest a possible role played by carboxymethylcellulose in the regulation of the genotoxic activity of selenium.

Antimutagenic Agents↗
PubMed2002

L-carnitine reduces lymphocyte apoptosis and oxidant stress in HIV-1-infected subjects treated with zidovudine and didanosine.

Apoptosis is critical to the progression of human immunodeficiency virus-1 (HIV-1) infection. It appears reasonable that antiretroviral therapies may not achieve a full control of the infection in the absence of an impact on apoptosis. We assigned 20 asymptomatic HIV-infected subjects with advanced immunodeficiency to receive either zidovudine (AZT), and didanosine (DDI) or the same regimen plus L-carnitine, a known antiapoptotic drug, for 7 months. Immunologic and virologic parameters were measured at baseline and after 15, 60, 120, and 210 days of treatment. We assessed on each time point the following: (a) the frequency of peripheral blood apoptotic CD4 and CD8 lymphocytes, CD4 and CD8 cells with disrupted mitochondrial membrane potential, and CD4 and CD8 cells undergoing oxidant stress; (b) the expression of the molecular markers of apoptosis Fas and caspase-1; and (c) the expression of p35/cdk-5 regulatory subunit that is involved in regulating cell survival and apoptosis. Absolute CD4 and CD8 counts and plasma viremia were also measured. Apoptotic CD4 and CD8 cells, lymphocytes with disrupted mitochondrial membrane potential, and lymphocytes undergoing oxidant stress were greatly reduced in subjects treated with AZT and DDI plus L-carnitine compared with those who did not receive L-carnitine. Fas and caspase-1 were down-expressed and p35 over-expressed in lymphocytes from patients of the L-carnitine group. No difference was found in CD4 and CD8 counts and viremia between the groups. No toxicity of L-carnitine was recognized. The addition of L-carnitine is safe and allows apoptosis and oxidant stress to be greatly reduced in lymphocytes from subjects treated with AZT and DDI.

Anti-HIV Agents↗
PubMed2002

Evaluation of commercial compost quality.

Ten commercial composts were evaluated on the basis of chemical, physical and biological characteristics and compared with a compost produced by a safe matrix in controlled conditions. FT-IR spectra, (13)C CP-MAS NMR spectra and molecular weights were also assayed on humic acids extracted from the composts. The results show that the origin of the starting materials affects the quality of the end products especially for their heavy metal content and genotoxic effect. The presence of a high percentage of low molecular weight fractions generally recorded in the humic acids from commercial composts could be due to uncorrected composting process. FT-IR and (13)C CP-MAS NMR spectra agree with functional group assignments, characterising the level of humification. The results show that commercial composts can display harmful properties probably due to the origin of the starting material, therefore a regulation about both compost production and characterisation should be suitable.

DNA Damage↗
PubMed2002

Nephrotoxicity and purpura associated with levofloxacin.

OBJECTIVE: To report a patient with lung cancer and idiopathic myelofibrosis with myeloid metaplasia who developed purpura and acute renal failure while receiving levofloxacin, and review the existing literature on quinolone nephrotoxicity. CASE SUMMARY: A 73-year-old white man, with a medical history of non-small-cell lung cancer and idiopathic myelofibrosis with myeloid metaplasia, was prescribed levofloxacin because of a lower urinary tract infection. Three days later, he presented with palpable purpura and erythematous skin lesions over the lower limbs and trunk, with a markedly reduced urinary output. Serum creatinine and urea nitrogen were 6.4 and 190 mg/dL, respectively. Levofloxacin was discontinued, and prednisone, furosemide, and intravenous fluids were given. The patient fully recovered over the ensuing 4 weeks. CONCLUSIONS: Nephrotoxicity associated with levofloxacin is uncommon. Allergic interstitial nephritis or vasculitis is believed to be the underlying pathologic process. Definitive diagnosis requires performance of renal biopsy, although this is not always feasible. In this case, a return of renal function to normal, with the disappearance of purpura following the discontinuation of levofloxacin and corticosteroid treatment, supports the presumptive diagnosis of a hypersensitivity reaction to levofloxacin.

Acute Kidney Injury↗
PubMedDate not supplied

Flutamide-associated acute liver failure.

The nonsteroidal antiandrogenic drug flutamide [4'-nitro-3'-(trifluoromethyl)isobutyranilide] is a safe and generally well-tolerated drug used for the treatment of prostate cancer. We describe the case of a 74-year-old male who developed life-threatening acute liver failure during flutamide therapy. Other causes of acute liver failure were appropriately ruled out and there was no evidence of active prostate cancer or liver metastases. The use of the Naranjo probability scale indicated a highly probable relationship between the development of acute liver failure and flutamide therapy. Severe liver dysfunction has been rarely documented in patients treated with flutamide, even though cases of fulminant liver failure have been described. A few cases have been reported also among patients with hirsutism being treated with flutamide. The mechanisms responsible for the occurrence of hepatotoxicity during treatment with flutamide are unknown. Mitochondrial dysfunction seems to be implicated. The potential of flutamide to act as a potent hepatotoxin should be borne in mind when treatment with this drug is being planned.

Acute Kidney Injury↗
PubMedDate not supplied

Effects of probiotic bacteria (VSL#3) on the polyamine biosynthesis and cell proliferation of normal colonic mucosa of rats.

BACKGROUND: Probiotics seem to possess tumour inhibitory properties, but few studies have investigated their actions on the cell proliferation of normal colonic mucosa. The effects of a probiotic mixture (VSL#3) on polyamine biosynthesis, Ki-67 levels and apoptosis in the normal colon of rats were studied. MATERIALS AND METHODS: For a 4-week period, 20 rats were fed a VSL#3 solution and 20 rats a saline solution. Samples from the colonic mucosa were collected at the end of treatment. Polyamines were detected by HPLC, ornithine decarboxylase activity by a radiometric technique, and apoptosis and Ki-67 by histochemical and immunohistochemical methods. RESULTS: VSL#3 caused a significant decrease in colonic polyamine levels, ornithine decarboxylase activity and Ki-67 compared to controls. A significant increase in the apoptotic index was also observed. CONCLUSION: Probiotics could also reduce proliferation rates in a condition not affected by hyperproliferative or neoplastic growth, when the normal control mechanisms are still completely effective.

Animals↗