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Biomedical subjects

C De Simone

Publications and source records attributed to C De Simone.

At least 127 records · Page 7Linked to original sources
PubMed1990

Role of bacterial lipopolysaccharides in the development of natural antibacterial activity mediated by human peripheral blood T lymphocytes.

The role of bacterial lipopolysaccharides (LPS) has been evaluated for their influence on the human T cell-mediated anti-Salmonella typhi activity. In nonendemic areas for salmonellosis this activity is exerted by CD4+ lymphocytes armed by IgA, whereas in endemic zones besides these cells also CD8+ lymphocytes armed by IgG display an elevated anti bacterial activity. These results suggest that, in endemic regions, continuous antigenic challenge and, in particular, that exerted by lipid A (the active moiety of LPS) may play a role in triggering this activity. In other series of experiments, pretreatment of endemic peripheral blood lymphocytes (PBL) with smooth and rough (Rb and Re) forms of Salmonella LPS leads to the inhibition of antibacterial activity. In this respect, Re-LPS, which contains lipid A covalently linked to the core-chetodeoxyoctonate, gives rise to the maximum of inhibition. Finally, fractionation of PBL by means of S. minnesota R345 (Rb) cytoadherence has led to the conclusion that anti bacterial activity is present in the Rb-unbound population, thus indicating that bacterial adherence to PBL is a distinct phenomenon from natural anti-S. typhi activity. The overall results suggest that lipid A is able to modulate the expression of antibacterial activity exerted by human peripheral blood T cells.

Adult↗
PubMed1989

Influence of methisoprinol (isoprinosine) on HIV-infected human lymphocytes: in vitro immunological, virological, and ultrastructural studies.

Methisoprinol (isoprinosine) is a synthetic compound with reported antiviral and immunomodulating properties. Results of the present study showed that methisoprinol at concentrations greater than or equal to 200 micrograms/ml reduces the p24 and gp120 viral antigen expression on the surface of human immunodeficiency virus (HIV)-infected lymphocytes and the reverse transcriptase levels. In addition, cell viability, the number of the CD4+ cells, and the CD4+/CD8+ cell ratio are higher in methisoprinol-pretreated cell suspensions than in untreated HIV-infected cell cultures. A quantitative freeze-fracture study on the density of the intramembranous particles (IMP) present on both fracture faces of the plasma membrane of lymphocytes has shown that pretreatment with methisoprinol induces a different molecular organization resulting in a nearly three times increase of IMP density.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Humoral and cellular immune responses to Salmonella typhi in patients with typhoid fever.

Humoral and cellular immune responses to Salmonella typhi have been studied in nine children with typhoid fever. By using dot immunobinding assay, anti-O-polysaccharide chain and antilipid A antibody titers have been evaluated during the course of the disease. Anti-O-polysaccharide chain antibody titers are lower at the first week and increase up to the third week of the infection. On the other hand, antilipid A antibody levels, which are already higher at the beginning of the disease, progressively augment during the following weeks. Concerning cellular immunity to S. typhi, antibacterial activity mediated by typhoid peripheral mononuclear cells has been determined. Results show this function to be depressed in the initial phase of typhoid, increasing with the time. Together, these data bring new insight on immunity in typhoid patients.

Antibodies, Bacterial↗
PubMed1989

Effects of substance P on the spontaneous binding of Salmonella minnesota R345 (Rb) to human peripheral blood lymphocytes.

The effects of substance P (SP) on Salmonella minnesota R345 (Rb) binding to human peripheral blood lymphocytes (PBL) were evaluated. Two parameters of bacterial cytoadherence were considered, namely the binding lymphocytes (BL) and the number of bound-bacteria/lymphocyte (BB). The results showed that SP inhibits both BL and BB in a significant manner. Furthermore, distribution of Salmonella binding to CD4+ and CD8+ lymphocytes was studied following SP pretreatment of lymphoid cells. This neuropeptide is able to hamper the bacterial cytoadherence to both T-cell subpopulations and, in particular, the inhibitory effect on the T-suppressor/cytotoxic subset was more pronounced. These findings are discussed in terms of SP intervention in the mechanism of host protection against invading microorganisms.

Antigens, CD↗
PubMed1989

Clinical and immunological assessment in HIV+ subjects receiving inosine-pranobex. A randomised, multicentric study.

Inosine-pranobex (methisoprinol, isoprinosine; INPX) is the p-acetamidobenzoic salt of N,N-dimethylamino-2-propanol and inosine in a 3:1 molar ratio. In early studies, INPX was found to partially inhibit human immunodeficiency virus (HIV) and to increase the immunocompetence of HIV-infected subjects in vitro. We report the results of a randomised, multicentric clinical trial carried out on 553 HIV+ patients. 261 individuals were treated with INPX (two 500 mg tablets every 6 h for 3 months) and the remaining 292 constituted the untreated control group. INPX treatment was associated with a slightly improved clinical condition or with a trend in that direction, as compared to the untreated group. A preservation of the CD4/CD8 cell ratio values, a decrease in the CD8+ cells and an increase in the Leu 2-7+ cell number better than in the untreated individuals was also observed in the patients taking INPX. No serious or adverse effects of INPX have been observed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Intravenous immunoglobulins in association with antibiotics: a therapeutic trial in septic intensive care unit patients.

The therapeutic use of iv immunoglobulins of the G class in association with antibiotics in patients with severe sepsis is reported. As compared to the randomized control group of patients treated with antibiotics alone, patient survival was only slightly improved (from 25% to 42%; NS); however, the defervescence time was significantly shorter (10 vs. 16 days), and a greater percentage of microbiologically positive cultures became negative (40% vs. 8%; p less than .01). The percentage of days on antibiotic treatment during ICU hospitalization was consequently reduced (38% vs. 95%; p less than .01). The therapeutic use of iv immunoglobulin G is discussed in terms of antibody substitution and modulation of the immune system.

Adult↗
PubMed1988

Inhibition of lymphocyte-mediated antibacterial activity by human seminal plasma.

Seminal plasma displays a suppressive function on many immunological responses. In light of recent findings on the antibacterial activity mediated by different lymphocyte subsets, we have assessed the effect of male inhibitory material (MIM) in this system. Results provide evidence that MIM pretreatment of peripheral blood lymphocytes (PBL) leads to a significant inhibition of antibacterial activity against Salmonella typhi and S. minnesota R345 (Rb). Both CD4+ and CD8+ cell-mediated activities are reduced by this treatment, while another defense mechanism (bacterial binding to PBL) is unaffected. Taken together, these results indicate a role for MIM in the depression of immune response and suggest that lymphocytes mediating antibacterial activity and bacterial cytoadherence are different entities.

Blood Bactericidal Activity↗
PubMed1988

Pharmacokinetics of zidovudine and concomitant inosine-pranobex in AIDS patients.

3'-azido-3'-deoxythymidine (AZT) was administered orally to 8 AIDS patients at a dose of 100 mg every 6 hours for 14 days. On days 8 - 14 the patients were also given 1 g inosine-pranobex (INPX) every 6 hours. On day 7, while the subjects were taking AZT alone and on day 14 while they were receiving AZT + INPX, blood samples were obtained over a 6-hour dosing interval for measurement of AZT by a specific AZT radioimmunoassay. AZT levels on day 14 were significantly higher than the corresponding levels on day 7, resulting in a 2-fold increase of the area under the serum concentration-time curve (AUC) and a prolongation of the mean half-life of AZT (44 to 70 min) during the INPX treatment. INPX is an immunomodulatory drug with an inhibitory effect on HIV. The potential advantages of a combined treatment AZT + INPX are: 1) need for lower dose of AZT for maintaining a therapeutic anti-retroviral level; 2) a longer interval period between AZT treatments; 3) a potential to enhance immunological response resulting from INPX treatment; 4) reduced costs of care for patients.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Enhancement of host resistance against Salmonella typhimurium infection by a diet supplemented with yogurt.

The effect of a diet supplemented with yogurt containing live lactobacilli (LAB) - Lactobacillus bulgaricus and Streptococcus thermophilus - on the response of inbred mice to infection with Salmonella typhimurium was elaborated. The results of our experiments were consistent with the hypothesis that modifications of the microflora influence the adherence of S. typhimurium to intestinal mucosa, the natural antibacterial activity of the Peyer's patches lymphocytes, the accumulation of the macrophages in the liver, the proliferative responses of the splenocytes. The relationship between modifications of the immune response following ingestion of yogurt with live LAB and increased defense mechanisms was confirmed by the bacterial counts in livers and spleens and by the reduced mortality to S. typhimurium infection.

Animals↗
PubMed1988

Treatment of severe psoriasis with somatostatin: four years of experience.

Over a period of 4 years, 20 patients suffering from severe forms of psoriasis (erythrodermic, sub-erythrodermic, resistant generalized forms and/or forms associated with acute arthropathy) were treated with 96 h of continuous i.v. infusion of somatostatin (Stilamin, Serono) diluted in D5W at 250 micrograms/h. In addition to the usual blood chemistry parameters, circadian levels of growth hormone (GH) and epidermal growth factor (EGF) were measured before, during, and after therapy. Approximately 2-3 weeks after termination of therapy, erythrodermic and suberythrodermic symptoms had disappeared. In some patients, a few lesions of psoriasis vulgaris remained, although they were much less severe. Remission of acute arthropathy was impressive. Blood chemistry parameters were unchanged after therapy. Circadian levels of GH and EGF, normal before therapy, were significantly decreased after therapy. The infusion was well-tolerated. Infusion rates of greater than 250 micrograms/h caused only some complaints of abdominal pain, nausea, and vomiting. During the 4 years, erythrodermic symptoms reappeared only in seven patients, three of whom were also arthropathic. After 6-8 months, they underwent a second course of somatostatin therapy with good results. The other patients are still able to control their disease with tar-based products alone or with low-dose 8-methoxypsoralen + UVA (PUVA) or UV therapy. The arthropathic patients control their symptoms with periodic low-dose nonsteroidal antiinflammatory drug therapy.

Epidermal Growth Factor↗
PubMed1988

The treatment of onychomycosis with a new form of tioconazole.

The difficulties encountered in the treatment of onychomycosis are primarily related to the necessity of prolonged systemic therapy. Many of these difficulties could, then, be avoided by the use of an effective local treatment. The present study compared the effectiveness and tolerability of two topical ungual preparations: a 28% solution of tioconazole and a 2% tincture of miconazole. The therapeutic results and tolerability of both preparations were found to be satisfactory. The tioconazole preparation proved to be slightly more effective although the difference was not statistically significant.

Adult↗
PubMed1988

Adherence of specific yogurt micro-organisms to human peripheral blood lymphocytes.

Yogurt lactic-acid-bacteria (LAB) consisting of Lactobacillus bulgaricus and Streptococcus thermophilus were evaluated for their capacity to bind to human peripheral blood lymphocytes (PBL). These micro-organisms adhere to human T lymphocytes, and bind to B lymphocytes, in high and low frequencies, respectively. In addition, a quantitative analysis of LAB binding to PBL was carried out using the same parameters previously applied to a Salmonella model. The effect of yogurt LAB on the natural anti-bacterial activity exerted by PBL was examined. Lymphocyte pretreatment with bacteria did not affect such functions. These findings are discussed in the light of the well known ability of yogurt LAB to modulate the immune response.

B-Lymphocytes↗