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Biomedical subjects

C De Simone

Publications and source records attributed to C De Simone.

At least 37 records · Page 2Linked to original sources
PubMed2001

Reduction of oxaluria after an oral course of lactic acid bacteria at high concentration.

BACKGROUND: Hyperoxaluria is a major risk factor for renal stones, and in most cases, it appears to be sustained by increased dietary load or increased intestinal absorption. Previous studies have shown that components of the endogenous digestive microflora, in particular Oxalobacter formigenes, utilize oxalate in the gut, thus limiting its absorption. We tested the hypothesis of whether oxaluria can be reduced by means of reducing intestinal absorption through feeding a mixture of freeze-dried lactic acid bacteria. METHODS: Six patients with idiopathic calcium-oxalate urolithiasis and mild hyperoxaluria (>40 mg/24 h) received daily a mixture containing 8 x 10(11) freeze-dried lactic acid bacteria (L. acidophilus, L. plantarum, L. brevis, S. thermophilus, B. infantis) for four weeks. The 24-hour urinary excretion of oxalate was determined at the end of the study period and then one month after ending the treatment. The ability of bacteria to degrade oxalate and grow in oxalate-containing media, and the gene expression of Ox1T, an enzyme that catalyzes the transmembrane exchange of oxalate, also were investigated. RESULTS: The treatment resulted in a great reduction of the 24-hour excretion of oxalate in all six patients enrolled. Mean levels +/- SD were 33.5 +/- 15.9 mg/24 h at the end of the study period and 28.3 +/- 14.6 mg/24 h one month after treatment was interrupted compared with baseline values of 55.5 +/- 19.6 mg/24 h (P < 0.05). The treatment was associated with a strong reduction of the fecal excretion of oxalate in the two patients tested. Two bacterial strains among those used for the treatment (L. acidophilus and S. thermophilus) proved in vitro to degrade oxalate effectively, but their growth was somewhat inhibited by oxalate. One strain (B. infantis) showed a quite good degrading activity and grew rapidly in the oxalate-containing medium. L. plantarum and L. brevis showed a modest ability to degrade oxalate even though they grew significantly in oxalate-containing medium. No strain expressed the Ox1T gene. CONCLUSIONS: The urinary excretion of oxalate, a major risk factor for renal stone formation and growth in patients with idiopathic calcium-oxalate urolithiasis, can be greatly reduced with treatment using a high concentration of freeze-dried lactic acid bacteria. We postulate that the biological manipulation of the endogenous digestive microflora can be a novel approach for the prevention of urinary stone formation.

Adolescent↗
PubMed2001

Probiotic bacteria enhance murine and human intestinal epithelial barrier function.

BACKGROUND & AIMS: The probiotic compound, VSL#3, is efficacious as maintenance therapy in pouchitis and ulcerative colitis. The aim of this study was to determine the efficacy of VSL#3 as a primary therapy in the treatment of colitis in the interleukin (IL)-10 gene-deficient mouse. Mechanisms of action of VSL#3 were investigated in T(84) monolayers. METHODS: IL-10 gene-deficient and control mice received 2.8 x 10(8) colony-forming units per day of VSL#3 for 4 weeks. Colons were removed and analyzed for cytokine production, epithelial barrier function, and inflammation. VSL#3 or conditioned media was applied directly to T(84) monolayers. RESULTS: Treatment of IL-10 gene-deficient mice with VSL#3 resulted in normalization of colonic physiologic function and barrier integrity in conjunction with a reduction in mucosal secretion of tumor necrosis factor alpha and interferon gamma and an improvement in histologic disease. In vitro studies showed that epithelial barrier function and resistance to Salmonella invasion could be enhanced by exposure to a proteinaceous soluble factor secreted by the bacteria found in the VSL#3 compound. CONCLUSIONS: Oral administration of VSL#3 was effective as primary therapy in IL-10 gene-deficient mice, and had a direct effect on epithelial barrier function.

Animals↗
PubMed2001

Microecology, bacterial vaginosis and probiotics: perspectives for bacteriotherapy.

Probiotics enriched in lactobacilli have been proposed as an effective and alternative tool to antibiotics for the treatment of bacterial vaginosis. The protective role of H(2)O(2)-producing lactobacilli has been strongly emphasized, but no clear-cut correlation appears to link the metabolic characteristics of administered lactobacilli with the clinical impact of probiotic therapy. On account of our review of basic mechanisms involved in bacterial vaginosis, we suggest that lactobacilli with an elevated arginine deiminase activity could have a greater therapeutic potential than strains producing only H(2)O(2). Preliminary results from our laboratory have demonstrated that treatment with probiotics containing arginine deiminase-positive lactobacilli improves clinical symptoms and is paralleled by a significant decline of polyamine levels in vaginal microenvironment. This is of outstanding interest due to the central role of polyamines in the pathogenesis of bacterial vaginosis. We should critically rethink, against this perspective, the use of probiotics for the treatment of affected women.

Anti-Bacterial Agents↗
PubMed2001

Abrupt-onset oculomotor paralysis: an endocrine emergency.

Pituitary apoplexy is a severe and potentially life-threatening condition that may be highly variable in its clinical presentation. We report a 37-year-old man presenting to the emergency department with diplopia that abruptly developed while he was eating canned and bottled food prepared at home. A computed tomography scanning revealed an isodense mass within the sellar region and, subsequently, a magnetic resonance imaging showed a pituitary apoplexy causing a compression of the right III and VI oculomotor nerves. There was no improvement with hydrocortisone therapy and the patient underwent a transsphenoidal excision of the mass with an uneventful course. Pituitary apoplexy may raise in the appropriate setting the suspicion of botulism. The abrupt-onset paralysis of oculomotor nerves has been described as the chief presenting sign of pituitary apoplexy in only few cases including this. A pathophysiology, differential diagnosis with botulism and other causes of multiple cranial nerve paralysis, and treatment are described.

Acute Disease↗
PubMed2001

Expression of cytokines, inducible nitric oxide synthase, and matrix metalloproteinases in pouchitis: effects of probiotic treatment.

OBJECTIVE: The efficacy of probiotic organisms in the treatment of pouchitis has been reported. In the present study, we evaluated the tissue levels of pro- and anti-inflammatory cytokines, nitric oxide synthase, and matrix metalloproteinases in control and inflamed pouches before and after antibiotic and probiotic treatment of patients with acute pouchitis. METHODS: Pouch biopsy samples were obtained from seven patients with pouchitis before and after antibiotic and probiotic treatment. Tissue samples from five patients with normal pouches were used as controls. Cytokines were determined by ELISA, matrix metalloproteinase activity was evaluated by zymograms, and nitric oxide synthase activity was determined by measuring arginine to citrulline conversion. RESULTS: Tissue levels of tumor necrosis factor a increased (p < 0.01) in pouchitis relative to uninflamed pouches and reduced after antibiotic and probiotic treatment. Also, interferon y and interleukin 1alpha (IL-1alpha) augmented in pouchitis, but their increase did not reach statistical significance. The latter, however, were lower (p < 0.05) after treatment with the antibiotics and probiotics. Tissue levels of IL-4 and IL-10 were unchanged in inflamed pouches and unaffected by antibiotic treatment. However, IL-10 increased (p < 0.05) after probiotic treatment. Moreover, inflamed pouches had higher levels of inducible nitric oxide synthase and gelatinase activities, which decreased after treatment. CONCLUSIONS: The ability of antibiotic and probiotic treatments to increase tissue levels of IL-10, at a higher level than those observed in control pouches, and to decrease, to levels present in control pouches, proinflammatory cytokine, inducible nitric oxide synthase, and matrix metalloproteinase activity may suggest a mechanism of action to explain the efficacy of this therapeutic regime in pouchitis.

Acute Disease↗
PubMed2001

Non-Herlitz junctional epidermolysis bullosa without hair involvement associated with BP180 deficiency.

Junctional epidermolysis bullosa (JEB) is a clinically and genetically heterogeneous recessively inherited blistering disease of the skin and mucous membranes due to impaired epithelial adhesion. In particular, defective expression of the 180-kD bullous pemphigoid antigen (BP180) has been correlated to a non-lethal (non-Herlitz) form of JEB, generalized atrophic benign epidermolysis bullosa (GABEB), characterized by widespread skin blistering healing with atrophy and by atrophic alopecia with onset in childhood. We report the case of a 33-year-old man suffering from a generalized blistering skin disorder since birth. He also presented nail dystrophy and tooth abnormalities. Mucosal involvement was limited to gingival erosion. Alopecia was absent and body, axillary and pubic hair were normal. Immunofluorescence analysis showed a markedly reduced expression of BP180, electron microscopy studies evidenced hypoplastic hemidesmosomes and Northern blot analysis confirmed a striking decrease in the amount of BP180 mRNA. The clinical features of our patient confirm that BP180 deficiency usually results in a non-Herlitz JEB form. However, the degree of skin, mucous membranes and hair involvement appears more variable and less typical than originally described for GABEB.

Adult↗
PubMed2001

Apoptotic effects of selected strains of lactic acid bacteria on a human T leukemia cell line are associated with bacterial arginine deiminase and/or sphingomyelinase activities.

The aim of the present work was, first, to analyze the apoptotic effect in vitro of sonicated preparations of selected strains of lactic acid bacteria on normal and tumor human lymphocytes. Incubation with bacterial samples led to a relevant time-dependent apoptotic cell death of Jurkat cells but not normal human peripheral blood lymphocytes. Lactobacillus brevis (CD2) samples were more efficient in inducing apoptosis of Jurkat cells than were samples of Streptococcus thermophilus (S244). In an attempt to characterize the mechanisms underlying these effects, we found that the apoptotic death-inducing ability of S244 preparations could be attributed to the ability of high levels of neutral sphingomyelinase activity to generate relevant amounts of ceramide, a known apoptotic death messenger, in Jurkat cells. On the other hand, our results indicate that apoptosis induced by CD2 samples could also be associated with high levels of arginine deiminase activity, which in turn was able to downregulate polyamine synthesis in Jurkat cells.

Apoptosis↗
PubMed2000

Apoptosis and surgical trauma: dysregulated expression of death and survival factors on peripheral lymphocytes.

BACKGROUND: Surgery and anesthesia cause depression of cell-mediated immunity in the postoperative period, including a reduction in the numbers of circulating lymphocytes. It has been claimed that this immunosuppression is associated with an increased incidence of postoperative infections. HYPOTHESIS: Lymphocytopenia following surgical trauma depends on a dysregulated expression of death/and survival factors associated with apoptosis that, in turn, interferes with the occurrence of postsurgical infections. DESIGN: Fifteen subjects undergoing elective surgery under general anesthesia entered the study. The data of the patients who had infections during the postoperative outcome were compared with the data of those who did not. The data were collected prospectively. MAIN OUTCOME MEASURES: Peripheral blood samples were drawn before the operation, and 24 hours and 96 hours after the operation. Lymphocytes were isolated and examined for quantification and phenotypic analysis of apoptosis using the 7-amino-actinomycin D method, as well as for Fas and Fas ligand, interleukin 1-converting enzyme p20/caspase-1, Bcl-2, and p35 expression. The rate of apoptotic cells was correlated with the incidence of postoperative infections. SETTING: University hospital. RESULTS: Twenty-four hours after surgery, CD4(+) and CD8(+) cells exhibited a significantly higher frequency of apoptosis as well as of Fas and Fas ligand and interleukin 1-converting enzyme p20/caspase-1 expressions than preoperatively. This increase was paralleled by a significant down-regulation of antiapoptotic factors such as Bcl-2. However, the expression of the proapoptotic factor p35 was reduced. In addition, we found a relationship between the rate of the apoptotic CD8(+) subset and the occurrence of infectious complications during the postoperative course. At 96 hours after surgery, the variables studied returned to the baseline levels. CONCLUSIONS: In the early postoperative period, surgical trauma under general anesthesia induces an intracellular perturbation on peripheral lymphocytes, resulting in both up-regulation of death-signaling factors and down-regulation of survival-signaling factors. The increased apoptosis of CD8(+) lymphocytes, but not of CD4(+) cells, seemed to be associated with a greater risk of postsurgical infections.

Analysis of Variance↗
PubMed2000

Evaluation of genotoxic and cytotoxic properties of pesticides employed in Italian agricultural practices.

In a program coordinated by the Italian Ministry of Works, we tested in vitro four pesticides widely employed in a developed agricultural region of central Italy. The four commercial agents were chosen on the basis of their diffusion in agricultural practice, knowledge of their active principle(s), and scant availability of data concerning their toxic and genotoxic activity. The agents were Cirtoxin, Decis, Tramat Combi (TC), and Lasso Micromix (LM). All substances were tested in three in vitro systems: Chinese hamster ovary (CHO) cells, a metabolically competent hamster cell line (Chinese hamster epithelial liver; CHEL), and root tips of Vicia faba (VF). The cytotoxic and genotoxic end points challenged were micronuclei and root tip length (RTL) in VF and mitotic index (MI), proliferation index (PI), cell survival (CS), cell growth (CG), cell cycle length (CCL), sister chromatid exchanges, chromosomal aberrations, and single-cell gel electrophoresis, or comet assay, in CHEL and CHO cells. Tested doses ranged from the field dose up to 200x the field dose to take into account accumulation effects. On the whole, tested agents appear to induce genotoxic damage only at subtoxic or toxic doses, indicating a low clastogenic risk. MI, PI, CS, CG, RTL, and CCL appear to be the less sensitive end points, showing no effects in the presence of a clear positive response in some or all of the other tests. Using cytogenetic tests, we obtained positive results for TC and LM treatments in CHO but not in CHEL cells. These data could be accounted for by postulating a detoxifying activity exerted by this cell line. However, cytogenetic end points appear to be more sensitive than those referring to cytotoxicity.

Agriculture↗
PubMed2000

Huriez syndrome: case report with a detailed analysis of skin dendritic cells.

We report a 60-year-old man with familial scleroatrophic syndrome of Huriez who developed squamous cell carcinomas on the affected skin of the right palm. Immunohistochemical analysis showed a marked reduction in the number of CD1a+, Lag+ and S100+ epidermal Langerhans cells, but not of CD1b+ and factor XIIIa+ dermal dendritic cells, limited to palmoplantar skin. The Langerhans cell depletion was not associated with an abnormal skin content of mRNA for factors involved in Langerhans cell development or recruitment in the epidermis, including granulocyte/macrophage colony-stimulating factor, transforming growth factor-beta1 and macrophage inflammatory protein-3alpha. The results indicate that other as yet unknown mechanisms may account for the reduced number of Langerhans cells in the affected skin of such patients.

Carcinoma, Squamous Cell↗
PubMed2000

Apoptosis and apoptosis-associated perturbations of peripheral blood lymphocytes during HIV infection: comparison between AIDS patients and asymptomatic long-term non-progressors.

This study was designed to compare the degree of lymphocyte apoptosis and Fas-Fas ligand (FasL) expression in AIDS patients and long-term non-progressors (LTNPs) and correlate these parameters with apoptosis-associated perturbations in lymphocyte function. LTNPs had a lower frequency of apoptotic CD4+ and CD8+ T cells compared with subjects with AIDS. This correlated with a lower frequency of cells expressing Fas and FasL. The frequency of selected lymphocyte populations exhibiting a disrupted mitochondrial transmembrane potential (DeltaPsim) and increased superoxide generation was lower in LTNPs than in patients with AIDS; these abnormalities were associated with lower levels of caspase-1 activation in LTNPs. The results indicate a significantly reduced level of apoptosis and apoptosis-associated parameters in LTNPs than in patients developing AIDS. Based on these findings, a crucial role for mitochondria can be predicted in the process of lymphocyte apoptosis during the evolution of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Fulminant purpuric rash.

We report on a fatal case of purpura fulminans caused by severe meningococcaemia. Despite early and aggressive treatment with the use of a specific algorithm and the maintenance of a stable haemodynamic status in the first hour since admission, purpura fulminans developed impressively over a few minutes. Necropsy showed microvascular thrombosis in the dermis but not in visceral organs, suggesting the diagnosis of meningococcal septic shock with purpura fulminans limited to the skin. Acquired deficiency of protein C, which exerts anticoagulant and antiinflammatory functions, is the central mechanism ultimately responsible for purpura fulminans. The disorder predicts a poor outcome of meningococcaemia and early and aggressive resuscitation is recommended in the emergency department with antibiotics, volume expansion, inotropic drugs, and protein C replacement. An attitude of scepticism is appropriate in the management of these patients even when early resuscitation is successful and haemodynamic parameters remain stable.

Adolescent↗
PubMed2000

Symptomatic crystalluria associated with indinavir.

OBJECTIVE: To report a case of severe and recurrent crystalluria resulting from the use of indinavir and to review the literature describing this adverse effect. CASE SUMMARY: A 26-year-old HIV-positive white woman had recurrent episodes of left-sided flank pain accompanied by dilation of the left renal collecting system while undergoing treatment with a triple-drug regimen including indinavir 1200 mg every 12 hours (full dosage). Typical indinavir crystalluria was observed, with no evidence of stones. Acute episodes were treated with intravenous fluids, diclofenac, and ciprofloxacin. Crystalluria and clinical symptoms eventually resolved with withdrawal of indinavir and substitution with a different protease inhibitor. Renal function remained normal. DISCUSSION: A wide spectrum of disorders of the urinary tract can occur in subjects taking indinavir, with potentially severe complications caused by crystalluria and stones. Indinavir is excreted in the urine; the low solubility of those crystals is the critical factor accounting for the risk of stone formation. An elevated pH with a reduced excretion of citric acid contributes to the low urinary solubility of indinavir. Pharmacokinetic interactions with other drugs, leading to elevated plasma concentrations of indinavir, and dehydration could also increase the risk of stone formation. The impact on renal function can be unfavorable over the long-term period. Cornerstones of treatment and prevention are increased fluid intake and possibly urinary acidification. Emergency drainage may be required for patients with severe obstruction. Reducing the dosage of indinavir has been proposed, but this carries the risk of viral mutations with development of resistance. CONCLUSIONS: Treatment with indinavir can result in crystalluria with potentially severe obstruction. All patients taking indinavir, not only those with documented crystalluria or renal effects from the drug, should greatly increase their fluid intake and have renal function checked at baseline and then monitored regularly. Urinalysis also should be performed regularly for appropriate monitoring and prevention.

Adult↗