Quality of local guidelines for surgical antimicrobial prophylaxis.

Surgical antimicrobial prophylaxis (AMP) is an effective measure to prevent surgical site infections. To determine the quality and availability of local guidelines for AMP, a survey was conducted in the public hospitals of a Northern Italian region. The guidelines for "Antimicrobial Prophylaxis in Surgery" by the Scottish Intercollegiate Guidelines Network (SIGN) were used as a standard by which the quality of the local guidelines was compared. The coverage of surgical specialities by local AMP guidelines was 93.1% for hospitals where guidelines had been developed at hospital level and 47% for hospitals where guidelines had been developed by individual surgical departments. Local guidelines recommended AMP for most surgical procedures (96%), including procedures with evidence against the use of antimicrobial prophylaxis (87% of these procedures). Only 8% of all procedure-specific guidelines (PSG) recommended an incorrect timing of AMP (not administering AMP at the induction of anaesthesia), while 41% recommended an incorrect duration (additional antimicrobial doses after completion of the surgical operation). This survey showed that having written protocols at local level does not necessarily mean they comply with available scientific evidence. Thus, the quality of local guidelines needs to be improved.

Glycated low density lipoproteins modify platelet properties: a compositional and functional study.

The interaction between low density lipoproteins (LDL) and platelets might play a central role in the development of atherosclerosis in diabetes. The aim of the present study was to investigate whether the glycation of LDL is associated with modifications of their physico-chemical and functional properties and to study the action of glycated LDL (glycLDL) on platelets. LDL and platelets were isolated from 15 healthy subjects. The content of thiobarbituric acid-reactive substances and the generalized polarization of the fluorescent probe Laurdan were determined in LDL glycated in vitro. Platelets were incubated with native LDL, GlycLDL, and minimally oxidized LDL, and the following parameters were evaluated: platelet aggregation, nitric oxide production, intracellular Ca(2+) concentrations, Na(+)/K(+)-adenosine triphosphatase (Na(+)/K(+)-ATPase), and Ca(2+)-ATPase activities. GlycLDL showed increased thiobarbituric acid-reactive substance levels, a red shift of the Laurdan emission maximum, and a decrease in generalized polarization, indicating a higher polarity and a reduced molecular order compared with native LDL. GlycLDL caused a significant increase in platelet nitric oxide production, intracellular Ca(2+) concentration, and aggregating response to ADP; an inhibition of the platelet membrane Na(+)/K(+)-ATPase activity; and a stimulation of Ca(2+)-ATPase activity. Minimally oxidized LDL did not cause statistically significant changes in the parameters studied. The present work demonstrates that glycation induces compositional and structural changes in LDL and suggests that an altered interaction between glycLDL and platelets might play a role in the vascular complications of diabetes.

Coagulative modifications in patients with systemic sclerosis treated with iloprost or nifedipine.

This study compared iloprost and nifedipine to ascertain whether they could improve parameters of endothelial and platelet functions in the treatment of Raynaud's phenomenon secondary to systemic sclerosis. Thirteen patients affected by systemic sclerosis were treated with intravenous infusion of iloprost, and 7 patients were treated with oral nifedipine. Blood samples were taken at baseline and after 6 and 12 months of therapy to assess main serological indexes of endothelial damage, thrombin activation, fibrinolysis, as well as natural inhibitors of coagulation. After 12 months of therapy, the patients treated with iloprost had a significant decrease in thrombomodulin levels (p = 0.02) and a significant increase in tissue-plasminogen activator levels (p = 0.007), in comparison with the patients taking nifedipine (p = 0.007). Moreover, patients treated with nifedipine showed increased levels of thrombin-antithrombin complex after 12 months of therapy in comparison with baseline values (p = 0.03) and in comparison with the values of the patients treated with iloprost over the same period (p = 0.05). These preliminary results thus seem to indicate that iloprost plays an important, if at least partial, role in the protection and restoration of endothelial integrity in patients with systemic sclerosis.

Influence of low density lipoprotein from insulin-dependent diabetic patients on platelet functions.

In the present work we studied in vitro the action of low density lipoproteins (LDL) isolated from normolipemic insulin-dependent diabetic (IDDM) patients on transmembrane cation transport, nitric oxide synthase (NOS) activity, and aggregating response to stimuli of platelets from healthy subjects to elucidate whether the modified interaction between circulating lipoproteins and cells might be one of the pathogenetic mechanisms of the increased platelet activation in IDDM. LDL were obtained by discontinuous gradient ultracentrifugation from 15 IDDM out-patients and 15 sex- and age-matched healthy subjects and used for incubation experiments with control platelets. Lipid composition and hydroperoxide concentrations were studied in LDL. Platelet aggregation responses to ADP, NOS activity, cytosolic Ca2+ concentrations, and platelet membrane Na+/K+-adenosine triphosphatase (Na+/K+-ATPase) and Ca2+-ATPase activities were measured after incubation. IDDM LDL showed an increased lysophosphatidylcholine content compared with that of control LDL. IDDM LDL significantly increased the platelet aggregating response to ADP, cytosolic Ca2+ concentrations, and plasma membrane Ca2+-ATPase activity and significantly reduced NOS activity and platelet membrane Na+/K+-ATPase activity compared with those of platelets incubated in buffer or cells incubated with control LDL. The effects exerted by IDDM LDL on platelet suspensions from healthy subjects mimic the alterations observed in platelets from diabetic subjects in basal conditions. Both the decreased activity of NOS and the higher cytoplasmic concentrations of Ca2+ might cause increased platelet activation, as observed in IDDM. In conclusion, the present study suggests a new mechanism with a potential role in the early development of atherosclerosis in diabetic patients, i.e. an altered interaction between circulating lipoproteins and platelets.

Hemostatic activity of the bovine parotid gland glycoconjugates.

The bovine parotid gland was studied by means of biochemical analyses and the glycoconjugates extracted were used to investigate the activity on the human hemostatic system. Thromboelastography was unable to reveal anticoagulant properties. Conversely, the Thrombin Time (TT) was prolonged in a statistically significant way and with dose-coupling response. Reptilase Time (RT) was affected by the highest concentration of extract suggesting that the bovine parotid glycoconjugates alter the fibrinogen polymerization.

Bovine submandibular gland extracts interact with the human hemostasis factors.

Glycoconjugates were extracted from the bovine submandibular gland and their anticoagulant activity was tested on the blood coagulation of human beings. The methods employed demonstrated that the thromboelastographic parameters were only modified by the highest concentration of glycoconjugates. Activated Partial Thromboplastin Time (aPTT) and Thrombin Time (TT) were affected by dose-coupling response. Prothrombin Time (PT) and Reptilase Time (RT) were not modified.

Effects of mammal submandibular gland glycoderivatives on human hemostatic system.

The aim of this study was to investigate the effects of glycoconjugate components extracted from the submandibular glands of four mammal species (rat, mouse, rabbit, hare) on human hemostatic system. The following analyses were performed: thromboelastography and hemocoagulation screening tests (Thrombin Time, Prothrombin Time, Partial Thromboplastin Time). Findings showed that all glycoconjugates induce modifications of fibrin clot formation time, modulus of elasticity and some hemocoagulation tests (TT, PTT). The anticoagulant effects were of inhibitory type.

[Level of protection against tetanus in an outpatient population]. / Livello di protezione contro il tetano in una popolazione ambulatoriale.

Protection levels against tetanus toxin were estimated in 332 patients, at our Laboratory, by means of the passive haemagglutination with turkey erythrocyte test. The testing showed that the protection level decreases with age, it is higher among males in those over 30 yrs; roughly 10% of those who were not vaccinated were protected. Furthermore, it has been demonstrated that in some cases the protection level remains high even after a long period of time since the last vaccination, whereas a certain percentage of the recently vaccinated patients is not protected; consequently the effectiveness of the vaccination must be checked by measuring the antibody titers.