[Bacterial meningitis in adults: a retrospective multicentric study in Tuscany (Italy)]. / Le meningiti batteriche dell'adulto: studio retrospettivo multicentrico della Toscana.

The Infectious Diseases Unit of Lucca Hospital conducted a multicentric retrospective study to evaluate the epidemiological and clinical features of adult patients affected by bacterial meningitis attending all the Infectious Diseases Units of Tuscany (Italy) from July 1999 to June 2004. A specific questionnaire was sent to all the units to collect information about each case of bacterial meningitis occurring in patients older than sixteen. Patients with meningitis by Mycobacterium tuberculosis were excluded from the analysis. Nine out of 12 Infectious Diseases Units of Tuscany took part in the study and 197 cases were identified. Most cases of meningitis occurred during 2002 with a slight reduction in cases in subsequent years. Streptococcus pneumoniae and Neisseria meningitidis were the most frequently isolated pathogens with an increase in diagnosis from 1999 to 2004; in 23.8% of patients no pathogens were isolated, with a reduction in meningitis from unknown aetiology from 1999 to 2004. Most patients were treated with a combination of two antibiotics, and corticosteroid drugs were added to the therapy; in the group of patients treated with corticosteroid drugs invalidating complications occurred in 23% of cases and 5% of patients died. In all, 27 out of 197 subjects (13.7%) developed invalidating complications and 20 out of 197 patients (10.2%) died.

Blunted inflammatory response to lipopolysaccharide endotracheal instillation due to thermal preconditioning.

AIM: Heat shock proteins (HSPs), induced by thermal stress, make the cells more resistant to following stress. We aimed to verify if rats heating reduces the production of TNF-alpha in a model of acute respiratory distress syndrome (ARDS). METHODS: We divided 34 Wistar rats in Group A and Group B. The rats of Group A received thermal shock and tracheal instillation of lipopolysaccharide (LPS), the rats of Group B only tracheal instillation of LPS. All the rats have been then subdivided in 6 subgroups sacrificed at different times after instillation of LPS: A30 and B30 at 30 min, A90 and B90 at 90 min and A180 and B180 at 180 min. We dosed the serum concentration of TNF-alpha and the values of every subgroup have been compared with the Student t-test. RESULTS: The serum concentration of TNF-alpha in the subgroup A90 resulted significantly lower than in the subgroup B90. CONCLUSIONS: The exposure to thermal stress resulting in the production of HSPs reduced the concentration of TNF-alpha in this model of ARDS.

Intraoperative positive fluid balance improves tissue diffusion of ceftizoxime.

AIM OF STUDY: To demonstrate that administration of fluids and the consequent improvement of fluid balance during a surgical procedure can modify the tissue diffusion of ceftizoxime. METHODS: Twenty-eight patients (30-79 years) undergoing major abdominal surgery of the colon were administered ceftizoxime 30 mg/kg i.v. at induction of anesthesia. A sample of arterial blood was taken before administration of the drug (t0) and then again at the time of vascular occlusion of the colon segment to be removed (t1). A sample of the segment of removed colon was taken. The patients were divided into two groups on the basis of the fluid balance between t0 and t1: group A (n = 17) with a fluid balance <1,000 ml and group B (n = 11) with a fluid balance >1,000 ml. The parameters evaluated in each group were: weight, height and age of the patients, serum and tissue antibiotic concentration, percent ratio of serum and tissue concentration, time elapsed between t0 and t1, volume of administered fluids between t0 and t1, diuresis and hourly diuresis between t0 and t1 and body fluid distribution, obtained using a bioelectrical impedance analyzer. The mean results obtained in the two groups were then compared using Student's t test. RESULTS: The balance of fluids calculated up to t1 was 675 +/- 308 ml for group A and 1,411 +/- 405 ml for group B (p < 0.01). The means of the recorded values that showed statistically significant differences were: mean percent concentration ratio (43.6 +/- 8.4 vs. 84 +/- 16%; p < 0.05), concentration in the colonic segment (16.3 +/- 7.9 vs. 37.2 +/- 25.9 mg/ml; p < 0.05), urinary volume gathered up to t1 (538 +/- 557 vs. 169 +/- 104 ml; p < 0.05), hourly urinary volume up to t1 (311.1 +/- 296 vs. 97.6 +/- 77.9 ml/h; p < 0.05), percent variation of resistance (95.1 +/- 5.1 vs. 89.7 +/- 8.6; p < 0.05). The other means did not show any significant statistical differences. CONCLUSIONS: A higher tissue water level seems to facilitate the penetration of the antibiotic into the tissue according to the pharmacokinetic characteristics of ceftizoxime: high amount of free drug (not bound to plasma proteins) and high hydrosolubility.

A novel continuous subcutaneous lactate monitoring system.

A novel continuous lactate monitoring system has been developed modifying the GlucoDay portable medical device (A. Menarini Diagnostics), already present in the European market, and used to continuously measure glucose levels. Lactate oxidase based biosensors have been developed immobilising the enzyme on nylon net and placing it on a Pt electrode. The biosensor was connected to the portable device provided with a micro-pump and coupled to a microdialysis system. It is capable to record subcutaneous lactate every 3 min. In vitro analytical results confirmed that the sensors respond linearly in the interval of concentration between 0.1 and 10 mmol/L, covering the whole physiological range. During prolonged monitoring periods, the response of the biosensors remained stable, showing a limited drift of 8%, within 60 h. Stability tests are still on route. However, preliminary results have shown a shelf life of about 10 months. In vivo experiments performed on healthy rabbits have demonstrated the good accuracy and reproducibility of the system. A correlation coefficient equal to 0.9547 (N=80) was found, which represents a good correlation between the GlucoDay and the laboratory reference analyser. A 16 h in vivo monitoring on a healthy volunteer has been also performed.

Novel planar glucose biosensors for continuous monitoring use.

Novel planar glucose biosensors to be used for continuous monitoring have been developed. The electrodes are produced with the "screen printing" technique, and present a high degree of reproducibility together with a low cost and the possibility of mass production. Prior to enzyme immobilisation, electrodes are chemically modified with ferric hexacyanoferrate (Prussian Blue). This allows the detection of the hydrogen peroxide produced by the enzymatic reaction catalysed by GOD, at low applied potential (ca. 0.0 V versus Ag/AgCl), highly limiting any electrochemical interferences. The layer of Prussian Blue (PB) showed a high stability at the working conditions (pH 7.4) and also after 1 year of storage dry at RT, no loss of activity was observed. The assembled glucose biosensors, showed high sensitivity towards glucose together with a long-term operational and storage stability. In a continuous flow system, with all the analytical parameters optimised, the glucose biosensors detected glucose concentration as low as 0.025 mM with a linear range up to 1.0mM. These probes were also tested over 50-60 h in a continuous flow mode to evaluate their operational stability. A 0.5 mM concentration of glucose was continuously fluxed into a biosensor wall-jet cell and the current due to the hydrogen peroxide reduction was continuously monitored. After 50-60 h, the drift of the signal observed was around 30%. Because of their high stability, these sensors suggest the possibility of using such biosensors, in conjunction with a microdialysis probe, for a continuous monitoring of glucose for clinical purposes.

Evaluation of a rapid immunochromatographic test for the serologic diagnosis of tuberculosis in Italy.

OBJECTIVE: To determine specificity, sensitivity and predictive values of a rapid immunochromatographic assay (ICT tuberculosis) for the diagnosis of tuberculosis (TB) in an Italian clinical setting, and to identify tentative new guidance for the interpretation of test results. METHODS: The ICT tuberculosis test is an immunochromatographic test based on the detection of IgG antibodies directed against five highly purified antigens secreted by Mycobacterium tuberculosis during active growth. Sera from 60 patients with active pulmonary (48 sputum smear-positive and six sputum smear-negative cases) and extrapulmonary (six cases) TB were obtained. Personal, anamnestic and clinical data were investigated and recorded for each patient. The control groups comprised 156 subjects: 40 healthy individuals, half of them Mycobacterium bovis BCG-vaccinated, and 116 patients with mycobacterial diseases other than TB (five cases), with nonmycobacterial lung diseases (30 cases), with nonmycobacterial nonlung diseases (30 cases), with nonmycobacterial diseases and rheumatoid factors positivity (30 cases), and with asymptomatic HIV infection (21 cases). For 21 individuals the test was simultaneously performed with both serum and whole blood sample. Each positive result of the ICT test was reported with regard to the number (1-4), position (A, B, C, D) and color intensity (+ to ++++) of the evidenced lines in order to assess the quality of the antibody response. RESULTS: The overall sensitivity and specificity were 56.7% and 90.4%, respectively. The sensitivity for pulmonary TB patients was 61.1% (66.7% for smear-positive and 16.7% for smear-negative cases) and 16.7% for extrapulmonary TB patients. The difference between ICT results in pulmonary TB patients and control subjects was statistically significant (P < 0.0001). The analysis of the positive ICT tests revealed that samples with strong color intensity (>/=++) and specific antibodies bound to antigens immobilized on line D were significantly more frequent in TB patients than in controls (P = 0.001 and P= 0.027, respectively). ICT test results with the presence of at least three visible lines were more often observed in the TB patients than in controls, although not reaching statistical significance (P = 0.052). No difference was observed between the results of the ICT test performed both on serum and whole blood sample. CONCLUSIONS: The ICT tuberculosis test was confirmed to be rapid and easy to perform without requiring special equipment, both on serum and whole blood sample. Our data, in accordance with those obtained in a previous study conducted in extra-European countries, confirmed higher sensitivities for the smear-positive TB patients than for the smear-negative TB patients, and for pulmonary TB patients than for the extrapulmonary TB patients. Data obtained on the quality of antibody response in the ICT positive samples, might be used to improve the performance of the test.

Antistaphylococcal (MSSA, MRSA, MSSE, MRSE) antibiotics.

S. aureus and coagulase-negative staphylococci such as S. epidermidis are important causes of infection of the bloodstream, cardiac valves, implanted devices, and skin, with repercussions on mortality and increased economic costs. Treatment of staphylococcal infections is made difficult by the increasing emergence of resistance to beta-lactams and other antimicrobials, including reduced susceptibility to glycopeptides. Penicillin must be used for infrequent penicillin-susceptible isolates, oxacillin and nafcillin are to be considered the major option for penicillin-resistant staphylococci, and glycopeptides are the drugs of choice for infections caused by methicillin-resistant strains. Co-trimoxazole, lincosamides, macrolides, tetracyclines, and fluoroquinolones are alternative agents, primarily in subjects allergic to beta-lactams. Newly introduced or experimental drugs, such as streptogramins (quinupristin-dalfopristin), oxazolidinones (linezolid), carbapenems (LY 333328), everninomicins (SCH 27899), and derivatives of tetracyclines (glycylcyclines), could be useful for therapy of infections caused by multiresistant staphylococci.