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Biomedical subjects

G Miragliotta

Publications and source records attributed to G Miragliotta.

At least 37 records · Page 2Linked to original sources
PubMed1996

[The importance of microbiological study in the therapy of odontogenic abscesses. A report of a clinical case].

INTRODUCTION: The medical treatment (i.e. antibiotic therapy) of orofacial infections sometimes proves inadequate for the recovery of the patients. Therefore, aside the antibacterial treatment, both incision and drainage are necessary to remove the causal factors. CLINICAL CASE: In our report we show that in case of failure of classic antibacterial therapy, surgical treatment alone does not allow by itself the recovery of the patient if microorganisms developed resistance to antibiotics. CONCLUSION: Recent studies have demonstrated a prevalence of anaerobes in orofacial abscesses. On this basis it appears important that in the analysis of the bacterial flora the handling of samples is carried out in the proper way in order to ensure the isolation of both aerobic and anaerobic species as well as the antibiotic sensitivity.

Abscess↗
PubMed1995

Preliminary evidence of endotoxic activity of Bilophila wadsworthia.

In this study we describe two properties of the Gram-negative bacterium Bilophila wadsworthia, namely the ability to clot Limulus lysate and the capacity to induce the production of tissue factor-like procoagulant activity by human mononuclear cells in vitro. Although exhibited at a lower degree when compared with those of typical Gram-negative bacteria or Gram-negative endotoxin those activities may account in part for Bilophila's pathogenicity. The capacity indeed to induce fibrin formation through the interaction with mononuclear cells suggests one mechanism by which the microorganism might cause abscess formation in the host. Moreover, since this activity is dependent on the number of Bilophila interacting with mononuclear cells, we hypothesize that this biological activity is closely influenced by growth environment.

Journal Article↗
PubMed1994

Possible significance of antibodies to Legionella pneumophila in HIV-1 infected patients with acute respiratory illness.

Eighty-six serum samples from 52 HIV-1 infected patients with complicating pneumonia illness were assayed for the presence of antibodies to Legionella pneumophila. In 25 of these patients Pneumocystic carinii has been previously diagnosed. Among all patients investigated only 4 had antibodies to L. pneumophila of significant titer of 128. In one patient L. pneumophila was demonstrated coexisting with P. carinii. Despite of a small proportion of patients with a significant titer of antibodies against L. pneumophila, the presence of this microorganism should be carefully investigated in AIDS patients with complicating pneumonia especially when the aetiological diagnosis is not defined; the reason is to improve the therapeutic treatment.

AIDS-Related Opportunistic Infections↗
PubMed1993

Human high molecular weight kininogen binds to human umbilical vein endothelial cells via its heavy and light chains.

High molecular weight kininogen (HK) is a multifunctional plasma glycoprotein that occupies a critical position in pathways that link inflammation and coagulation. Excision of the vasoactive peptide bradykinin by plasma kallikrein results in kinin-free HK that consists of a 65-Kd N-terminal heavy chain (HK-HC) linked to the C-terminal 45-Kd light chain (HK-LC) by a disulfide bridge. HK-HC is an inhibitor of SH-proteases and HK-LC contains the binding sites for coagulation cofactors prekallikrein and factor XI. HK has previously been shown to bind specifically to human umbilical vein endothelial cells (HUVEC) in a zinc(2+)-dependent manner by a single class of high-affinity binding sites. We have further characterized that interaction in order to determine the cell-binding regions of HK. Competition binding experiments have indicated that either HK-LC or HK-HC was able to inhibit the binding of labeled HK with a 50% inhibitory concentration (IC50) of 77 nmol/L and 89 nmol/L, respectively. Cleaved two-chain HK (HKa) had an IC50 of 73 nmol/L, whereas uncleaved HK had an IC50 of 335 nmol/L. Direct binding experiments have indicated that HUVEC bind both purified [125I]HK-HC and [125I]HK-LC in a zinc(2+)-dependent manner and that HK-LC did not displace bound HK-HC. The light chain of low molecular weight kininogen or prekallikrein-binding region of HK did not inhibit the binding of HK to HUVEC. Our results, therefore, indicate that (1) HK is capable of binding to endothelial cells via both heavy and light chain moieties, (2) HKa has a higher affinity to HUVEC, and (3) purified heavy and light chains are capable of directly binding to HUVEC. The data are consistent with the presence of a single high-affinity site for HK on endothelial cells within which are subsites that bind to heavy and light chains.

Binding Sites↗
PubMed1993

Clinical efficacy of azithromycin in lower respiratory tract infections.

A total of 51 patients with acute exacerbation of chronic bronchitis and pneumonia were enrolled: 27 treated with azithromycin (500 mg once a day for 3 days), and 24 with roxithromycin (150 mg every 12 hours for 7 days). The two regimens were equally effective, with clinical cure in 80% and 72% of patients respectively. Bacteriological eradication on day 19-23 was obtained in 7/11 cases (64%) and in 6/13 cases (46%) in the two groups, respectively. No side effects occurred in patients treated with azithromycin, while they occurred in the roxithromycin group (2 vomiting and 1 gastritis). Clinical and bacteriological efficacy, excellent tolerability, simplified dosage (single daily dose) and short-course (3 days) therapeutic regimen make azithromycin, in our experience, efficacious for the treatment of acute exacerbation of chronic bronchitis and community-acquired pneumonia.

Adolescent↗
PubMed1993

Influence of short-chain fatty acids produced by anaerobic bacteria on procoagulant activity produced by Escherichia coli and Bacteroides fragilis-stimulated leucocytes: possible role in intra-abdominal abscess formation.

The effect of selected short-chain fatty acids (SCFA) produced by anaerobic bacteria on the production in vitro of procoagulant activity (PCA) by human mononuclear cells stimulated by either Escherichia coli or Bacteroides fragilis which are common pathogens in intra-abdominal infections was investigated. In particular, acetic, propionic, succinic, butyric, and isobutyric acids were evaluated. Acetic, butyric, and isobutyric acids were able to inhibit significantly the production of PCA by bacteria-stimulated mononuclear cells. Since the production of PCA leads to the deposition of fibrin which is considered critical to the establishment of intra-abdominal abscesses, the inhibitory effect exerted by SCFA present in the inflammatory environment might play an important modulating role in the development of abscesses complicating intra-abdominal infections.

Bacteroides fragilis↗
PubMed1992

Legionellosis associated with artesian well excavation.

In October 1990 pneumonia due to Legionella pneumophila was diagnosed in two employees working in the area of Apulia, southern Italy, where artesian wells were in construction. Although the exposure to excavation has been associated with Legionnaires' disease, in our investigation the illness occurred only in those employees who were present when the water emerged from the ground under high pressure. On the basis of this report, water appears as the most likely reservoir of the organism and the main route of infection.

Adult↗
PubMed1991

Endotoxin release after antibiotic treatment and its potential pathogenetic role in coagulative disorders of patients with gram-negative sepsis.

The liberation of endotoxin by gram-negative bacteria upon antibiotic treatment might be of clinical relevance in terms of adverse effects of antibiotic therapy in patients with gram-negative infections. In this paper we have taken into consideration the endotoxic material released by Salmonella typhimurium SH9178 after treatment with either ofloxacin and norfloxacin (which act as DNA-gyrase inhibitors) or imipenem (which affects the bacterial cell wall) in its capacity to induce in-vitro production of procoagulant activity, tissue factor-like, by human mononuclear cells. Endotoxin released from Salmonella typhimurium after treatment with the above antibiotics behaves as the typical endotoxin of gram-negative bacteria in its capacity to induce procoagulant production. Indeed human mononuclear cells after prolonged incubation with supernatants of antibiotic-treated Salmonella were able to shorten the recalcification time of normal but not Factor VII deficient plasma (tissue factor-like activity). On this basis we hypothesize that this mechanism, leading to the activation of blood coagulation through the extrinsic pathway, might be closely involved in thrombohemorrhagic disorders sometimes complicating the antimicrobial therapy of gram-negative sepsis.

Anti-Infective Agents↗
PubMed1990

Inhibition of neutrophil functions by scrapie prion protein: description of some inhibitory properties.

The effect of scrapie prion protein (PrP) either in the native or in the denatured form was studied on in vitro responses of human neutrophils. Incubation of neutrophils with native PrP caused an inhibition of their aggregation induced by cytochalasin B. Moreover, the denatured form was in itself a strong aggregation inducer. When evaluating the effect on generation of neutrophil superoxide anion (O2) we found that neutrophils released O2 in response to the denatured from only but the native form was ineffective. Similarly, neutrophil discharge of beta-glucuronidase which represents the azurophilic granule marker was stimulated in a dose-dependent form by the denatured PrP 27-30 whereas the native form was almost completely devoid of any activity. These results indicate that several aspects of neutrophil function can be altered by the native form of prion protein PrP 27-30. This might be responsible for the impaired phagocytic cell activity explaining, at least in part, the absence of any inflammatory reaction during scrapie infection.

Cell Aggregation↗
PubMed1989

The ability of mononuclear cells to coagulate blood in response to Coxiella burnetii.

Endocarditis is a rather frequent complication of Q fever caused by Coxiella burnetii. We examined the ability of phase I (virulent) or phase II (avirulent) C. burnetii to coagulate blood in the presence of human blood mononuclear cells in vitro. After incubation for 4 h, virulent phase I C. burnetii was an effective stimulant for mononuclear cells. Since this interaction is a potent trigger of blood coagulation through the extrinsic pathway, it could be responsible for the local deposition of fibrin on the surface of infected valves and the development of large vegetations in cases of endocarditis complicating Q fever.

Blood Coagulation↗
PubMed1989

Different priming on human neutrophil respiratory burst by lipopolysaccharides from phase I and phase II Coxiella burnetii.

Human neutrophils produce small amounts of superoxide anion when stimulated with the chemotactic peptide FMLP; preincubating neutrophils with low concentrations of lipopolysaccharides (LPS) markedly increases this response, an effect referred to as priming. In this work LPS from Coxiella burnetii either phase I (virulent) or phase II (avirulent) were examined for their ability to induce priming. Results clearly show that only LPS from phase II microorganism was able to increase the release from neutrophils upon subsequent stimulation with FMLP. This effect was abolished by preincubation of LPS with polymyxin B. This finding may account for the ability of Coxiella burnetii phase I to escape intracellular phagocyte killing during persistent infections.

Coxiella↗