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Biomedical subjects

C De Simone

Publications and source records attributed to C De Simone.

At least 163 records · Page 9Linked to original sources
PubMed1982

Vitamins and immunity: II. Influence of L-carnitine on the immune system.

Vitamin A affects the antibody responses and may affect phagocytic function and properdin levels. Pyridoxine deficiency impairs nucleic acid synthesis and depresses antibody formation, delayed hypersensitivity reactions and the ability of phagocytes to kill bacteria. Pantothenic acid deficiency impairs antibody formation. Vitamin C deficiency increases the incidence of infection, primary by a negative influence on reparative processes. Deficiencies of other vitamins either have not been sufficiently studied or have a variable effect. Moreover, even substances which for their biosynthesis require an adequate vitamin supplementation may exert immunomodulatory influences. With this respect the authors report their results on the influence of L-carnitine on the immune system. L-carnitine increases the proliferative responses of both murine and human lymphocyte following mitogenic stimulation and increase polymorphonuclear chemotaxis. Furthermore, L-carnitine, even at minimal concentrations, neutralizes the lipid induced immunosuppression.

Animals↗
PubMed1982

Reversibility by L-carnitine of immunosuppression induced by an emulsion of soya bean oil, glycerol and egg lecithin.

Experimental and clinical data appear to indicate that Intralipid--an emulsion of soya bean oil, glycerol and egg lecithin--which is usually employed to improve caloric intake of parenteral nutrition regimens, may compromise human host defence mechanisms and therefore expose patients to an increased incidence of infectious diseases. Since from a biochemical point of view it has been suggested that a possible way whereby the somewhat poor reputation of Intralipid--attributable to the liver damage and the persistent lipaemia which attend its use--might be improved is to give supplementary carnitine which acts as a rate-limiting factor in the removal of the fat emulsion from blood, we hypothesized that the addition of carnitine to Intralipid could also result in a improvement of the immune responses both "in vitro" and "in vivo". Our results lend some support to the hypothesis in favour of a metabolic basis for some of the immunosuppressive properties of Intralipid and justify the inclusion of L-carnitine in parenteral nutrition regimens which, by abrogating some co-factor limitation, improves the immune responses of the host.

Carnitine↗
PubMed1982

Human eosinophils and parasitic diseases. II. Characterization of two cell fractions isolated at different densities.

A new procedure, based on centrifugation through multiple discontinuous gradients of polyvinylpyrrolidone-coated silica particles has been developed for the separation of almost pure eosinophils from blood samples of healthy donors. When this technique is employed for the purification of eosinophils from the peripheral blood of patients with parasitic diseases, two cell fractions almost pure in eosinophil granulocytes are harvested at different densities. Preliminary results, concerning the characterization of these cell fractions, indicate that in the terms of detectable membrane receptors and K cell activity, two distinct eosinophil subpopulations can be recognized.

Amebiasis↗
PubMed1980

[Effect of antibiotics on spontaneous and direct migration of human leukocytes. Preliminary findings].

Like other human blood cells, neutrophiles can travel enter tissues spontaneously. This apparently casual journeying is arrested in the presence of infection and they migrate to the site of the lesion. Experiments in vitro have shown that tetracycline, rifamycin, chloramphenicol, and cefuroxine inhibit such migration. In the present paper, it is demonstrated that ampicillin and tauglycolcillin, a new semi-synthetic penicillin, exert no significant influence on either direct or spontaneous neutrophile migration.

Adult↗
PubMed1980

[Influence of antibiotics on leukocyte migration].

Polymorphonuclear granulocytes play an important role in the immediate unspecific host response, and a depression of their functions can be found in many patients with severe or recurrent infections. Therefore administration of drugs causing such impairment in PMN function may be regarded as an additional risk for negative side effects to the patient. In our report the influence of 13 antibiotics--amphotericin B, ampicillin, tauglicolcillin, amoxicillin, cloxacillin, dicloxacillin, cephaloridine, cefalexin, cefuroxime, chloramphenicol, gentamicin, rifamycin, fosfomycin--on the granulocyte spontaneous and induced migration is investigated under in vitro experimental conditions. Human PMN preincubated with the antibiotics appropriately brought to the desired concentrations (therapeutic dose, 1/10 and 10X) in Hepes-Medium 199-water solution pH 7.2, were washed three times and tested for spontaneous and induced migration under agarose. Our experiments demonstrate that amphotericin B, cefalexin, cephaloridine, cefuroxime, chloramphenicol, dicloxacillin, gentamicin and rifamycin can inhibit in vitro human PMN chemotaxis and/or random migration. Inhibition of intracellular respiratory enzyme synthesis, presence of inactive metabolites of the drug, alterations of cyclic AMP and GMP or of the membrane bound divalent cations can be responsible of the phenomenon.

Anti-Bacterial Agents↗
PubMed1980

[Effect of vitamin B6 on some immune responses in chronic uremia (author's transl)].

Patients with chronic uremia undergoing periodic haemodialysis were found to have low levels of vitamin B6 (12 out of 18 patients). The same subjects also showed a reduction of the immunocompetence. The AA. report that the administration of pyridoxine (100 mg/die for 4 weeks) can induce a normalization of the vitamin levels and of some immunological parameters.

Adult↗
PubMed1978

[Inhibition of EA and EAC rosette formation by sera of patients with vesical schistosomiasis].

Circulating immune complexes were investigated by the E.A. and E.A.C. rosette inhibition test in sera samples from patients infested by Schistosoma haematobium. About 60% of the patients demonstrated significantly higher inhibition values than controls. The material inhibiting E.A.C. rosette formation was precipitated by 3.5% polyethilene glycol, thus excluding the role of C3 fragments and suggesting that inhibition was due to immune complexes.

Antigen-Antibody Complex↗
PubMedDate not supplied

Effect of adherence to plastic on peripheral blood monocyte and alveolar macrophage chemiluminescence.

The chemiluminescence of peripheral blood monocytes and alveolar macrophages was determined in the presence of luminol and lucigenin, either before or after the cell adherence to the luminometer curvettes. In the case of monocytes, cell adherence induces an increase of luminol-dependent chemiluminescence and has almost no effect on the lucigenin-dependent chemiluminescence. However, it shows a strong inhibition of the lucigenin-dependent chemiluminescence and almost no effect on luminol-dependent chemiluminescence, in the case of alveolar macrophages. These results show that adhesion to plastic alters the metabolic burst of both monocytes and alveolar macrophages. Although the mechanisms are poorly understood, they seem to be related to the modifications that take place during the differentiation of peripheral monocytes to alveolar macrophages.

Acridines↗
PubMedDate not supplied

Human eosinophil heterogeneity.

The aim of this review is to examine some of the most important findings pointing toward human eosinophil heterogeneity. Special importance is given to cell density, surface receptors, metabolism and response to biological products or synthetic compounds.

Eosinophils↗
PubMedDate not supplied

Shuttle walking test and 6-minute walking test induce a similar cardiorespiratory performance in patients recovering from an acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: The incremental shuttle walking test (SWT) has recently been proposed as a more valid and reproducible alternative to the conventional 6-min walking test (6MWT) in the evaluation of exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To compare the cardiorespiratory performance obtained during two sessions of SWT with that obtained during two sessions of 6MWT. METHODS: We examined 18 patients (forced expiratory volume in 1 s: 48 +/- 14%) recovering from an acute exacerbation of COPD that had required hospitalization. In the same afternoon, each patient performed two SWT and two 6MWT, with an interval of at least 30 min between each test; the sequence of the tests was randomized. RESULTS: Mean walking distance was greater in the second SWT test than in the first SWT. The changes from baseline in systolic blood pressure, heart rate, respiratory rate, oxygen saturation and dyspnea Borg index at the end of the test were similar between the two 6MWT and the two SWT. There was a highly significant correlation between walking distances measured during SWT and during 6MWT (rho: 0.85, p < 0.0005). Neither SWT nor 6MWT correlated with functional data of COPD. CONCLUSIONS: SWT, though being considered to be closer to a submaximal exercise test than 6MWT, does not induce a greater cardiorespiratory performance than 6MWT in patients recovering from acute exacerbation of COPD.

Acute Disease↗
PubMedDate not supplied

Effect of Bifidobacterium infantis on Interferon- gamma- induced keratinocyte apoptosis: a potential therapeutic approach to skin immune abnormalities.

Current management of atopic dermatitis is mainly directed to the reduction of cutaneous inflammation. Since patients with atopic dermatitis show abnormalities in immunoregulation, a therapy aimed to adjust their immune function could represent an alternative approach, particularly in the severe form of the disease. Indeed, T-lymphocytes constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated T-cell induced keratinocyte apoptosis appears to be an important pathogenetic factor of the eczematous disease. In recent years, attention has been focused on the interaction between host and probiotics which may have anti-inflammatory properties and immunomodulatory activities. The aim of the present work is to investigate the effect of a selected probiotic extract, the Bifidobacterium infantis extract, on a human keratinocyte cell line (HaCaT) abnormal apoptosis induced by activated-T-lymphocyte. An in vitro model of atopic dermatitis was used to assess the ability of the probiotic extract to protect HaCaT from apoptosis induced by soluble factors (IFN-gamma and CD95 ligand) released by human T-lymphocytes in vitro activated with anti-CD3/CD28 mAbs or Phytohemoagglutinin. Evidence is given that the bacterial extract treatment was able to totally prevent T lymphocyte-induced HaCaT cell apoptosis in vitro. The mechanism underlying this inhibitory effect has been suggested to depend on the ability of the bacterial extract to significantly reduce anti-CD3/CD28 mAbs and mitogen-induced T-cell proliferation, IFN-gamma generation and CD95 ligand release. These preliminary results may represent an experimental basis for a potential therapeutic approach mainly targeting the skin disorders-associated immune abnormalities.

Apoptosis↗
PubMedDate not supplied

Acute cholecystitis and pancreatitis in a patient with biliary sludge associated with the use of ceftriaxone: a rare but potentially severe complication.

Ceftriaxone may precipitate in the bile leading to the formation of biliary sludge. Biliary complications, even serious ones, have rarely been described in patients treated with this antibiotic. A 71-year-old woman presented to the emergency room with biliary sludge complicated by acute cholecystitis and pancreatitis after 10 days of treatment with ceftriaxone (2 g, 40 mg/kg per day). There had been no evidence of sludge or gallstones on a transabdominal ultrasonography performed 6 months earlier. The patient underwent open cholecystectomy and recovered fully. Ceftriaxone should be kept in mind as a potential cause of biliary sludge. In most cases, resolution of sludge occurs after interruption of ceftriaxone. Young subjects, patients receiving a prolonged course and a daily dose > or = 40 mg/kg, and subjects with impaired gallbladder emptying have a greater risk of ceftriaxone-associated sludge. Cholecystectomy is the definitive therapy for severe complications.

Acute Disease↗