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Biomedical subjects

G Mercurio

Publications and source records attributed to G Mercurio.

At least 19 recordsLinked to original sources
PubMed2003

Using environmental stressor information to predict the ecological status of Maryland non-tidal streams as measured by biological indicators.

In Maryland. U.S., an interim framework has recently been developed for using biologically based thresholds, or 'biocriteria', to assess the health of nontidal streams statewide at watershed scales. The evaluation of impairment is based on indices of biological integrity from the Maryland Biological Stream Survey (MBSS). We applied logistic regression to quantify how the biotic integrity of streams at a local scale is affected by cumulative effects resulting from catchment land uses, point sources, and nearby transmission line rights-of-way. Indicators for land use were developed from the remote sensing National Land Cover Data and applied at different scales. We determined that the risk of local impairment in nontidal streams rapidly increases with increased urban land use in the catchment area. The average likelihood of failing biocriteria doubled with every 10% points increment in urban land, thus an increase in urban land use from 0 to 20% quadruples the risk of impairment. For the basins evaluated in this study, catchments with more than 40-50% urban land use had greater than 80% probability of failing biocriteria, on average. Inclusion of rights-of-way and point sources in the model did not significantly improve the fit for this data set, most likely because of their low numbers. The overall results indicate that our predictive modeling approach can help pinpoint stream ecosystems experiencing or vulnerable to degradation.

Ecosystem↗
PubMed2003

Efficacy and safety of continuous intravenous infusion of remifentanil in preterm infants undergoing laser therapy in retinopathy of prematurity: clinical experience.

BACKGROUND: Preterm infants often require surgery. As experimental evidence suggests that premature infants may experience pain and this could even result in fatal complications, the anaesthesiologist must face problems related to lowbirth weight, high risk of hypothermia, concomitant pulmonary disease and metabolic and receptor immaturity. Recently remifentanil has been considered an optimal analgesic drug in a preterm infant undergoing mechanical ventilation and frequent surgical manoeuvres, but no clinical studies have been reported in the literature. The aim of our study was to evaluate the efficacy of a continuous intravenous infusion of remifentanil in premature infants undergoing laser therapy for retinopathy of prematurity (ROP). METHODS: Six premature infants with ROP were scheduled for laser therapy. The procedure was performed in the neonatal intensive care unit. Transcutaneous carbon dioxide, pulse oximetry, respiratory rate, ECG and noninvasive blood pressure were continuously monitored. Infusion of remifentanil started with a dose of 0.75-1 microg x kg-1x min-1, 1 h before surgery. A midazolam bolus dose (0.20 mg x kg-1) was administered and the remifentanil infusion was increased to 3-5 microg x kg-1x min-1 taking into account haemodynamic and respiratory changes or spontaneous movements. RESULTS: Increased dosage was necessary only for 10 min during the procedure. No changes in temperature and ventilatory settings were observed and after 2 h from the surgical procedure the preterm infants were back to their preoperative status. CONCLUSIONS: A continuous infusion of remifentanil allowed optimal control of surgical stress and a return to preoperative status and ventilatory settings without side-effects.

Anesthetics, Intravenous↗
PubMed2002

Sedation in the Intensive Care Unit. The basis of the problem.

The authors briefly discuss the advantages and limits of sedation in critically ill patients. They also focus the importance of an individualized sedative approach which provides pain relief and modulates stress response, allowing patients to be easily arousable and cooperative as necessary.

Procedural Sedation↗
PubMed2001

De-escalation antimicrobial chemotherapy in critically III patients: pros and cons.

In spite of advances in critical care, nosocomial infections still have a considerable impact on Intensive Care Unit (ICU) and hospital length of stay, mortality and costs. Several authors suggest that antibiotic therapy should be instituted as soon as sepsis is suspected in critically patients. Over the last two decades the rates of occurrence for pathogens have significantly changed under selective pressure from broad-spectrum antimicrobial therapy. Shifts from predominance of gram-negative to gram-positive organisms and outbreaks of resistant pathogens address the need for appropriate empirical regimens. Agents such as ceftazidime, imipenem and, more recently, meropenem and tazobactam have been used successfully as monotherapy. Two different clinical trials have reported that meropenem monotherapy is significantly more effective than ceftazidime-based therapy. Because of the outbreak of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, some investigators suggest adding a glycopeptide to beta-lactamase inhibitor and carbapenem as initial empirical therapy. Such a regimen should be administered before definitive proof of infections and until the results of microbial investigation are available (de-escalation antimicrobial chemotherapy). On the other hand, several authors do not recommend glycopeptide administration in an attempt to limit nosocomial outbreaks of vancomycin-resistant enterococci (VRE) and staphylococci (VRS) and to avoid secondary drawbacks, such as nephrotoxicity and ototoxicity. De-escalation antimicrobial chemotherapy should be tailored to critically ill patients according to their clinical status, severity of illness and suspicion of sepsis or nosocomial pneumonia.

Anti-Bacterial Agents↗
PubMed2001

[Acute respiratory failure in organ transplantation and immunodepressed patients].

Recently, noninvasive ventilation (NIV) has been introduced as a new and alternative ventilatory method. The efficacy of NIV has been reported in immunosuppressed patients, with the decrease in drawbacks related to mechanical ventilation by endotracheal intubation. The authors propose an up-date on the use of NIV in transplanted patients.

Adult↗
PubMed1998

[Magnetic resonance imaging of seronegative sacroiliitis].

INTRODUCTION: The inflammatory involvement of the sacroiliac joint is frequent during seronegative spondylarthritis. The clinical diagnosis of sacroiliitis may be very difficult, especially in the early stage, because joint motion cannot be assessed directly and the clinical picture is very similar to that of lumbar pain. Conventional radiography is negative as long as the structural change in the joint is limited to the synovial membrane and the cartilage (early stage). Computed Tomography (CT) also has many drawbacks, and thus the changes can be shown only when chondritis and enthesitis have already damaged the bone. The disease onset is usually preceded by a long latency; early diagnosis is needed for a proper and timely treatment, which can be made only with a highly sensitive and specific technique. We investigated the diagnostic accuracy of MRI in the early detection of sacroiliitis during seronegative spondylarthritis. MATERIAL AND METHODS: Forty patients with suspected sacroiliitis and negative radiographic findings were submitted to MRI; thirty-seven of them were HLA B27 positive. MRI was performed with a .5 T superconducting unit; T1-weighted SE, T2-weighted FSE, T2* GE, and STIR images were acquired on the oblique coronal plane parallel to the anterior sacrum. Ten asymptomatic volunteers were also examined as a control group. RESULTS: An irregular sacral border and marrow changes at the insertion of the sacroiliac ligaments were seen in 3/10 asymptomatic volunteers. MRI was negative in 7/40 patients, while the synovial compartment was replaced by some tissue with low signal intensity of T1 and high signal on T2 in the other 33 patients; this finding was referred to synovial pannus. Persisting low-signal foci were seen in the synovial compartment in 16/33 patients, which were referred to spared cartilage. High-signal regions were depicted at the bone periphery in 9/33 patients, which areas were consistent with bone erosion; the subchondral bone was markedly hypointense in 5 of these patients, indicating sclerosis. Finally, diffuse high signal intensity was found in the bone marrow in 3/33 patients and referred to infectious sacroiliitis. CONCLUSIONS: MRI appears the method of choice for the early detection of seronegative sacroiliitis because it can show the early changes in cartilage and subchondral bone, filling the gap between the onset of symptoms and radiographic evidence. Moreover, MRI uses no ionizing radiations and makes therefore a precious tool for the diagnosis and follow-up of young patients, hopefully decreasing the use of CT which however provides better detailing of bone and bone degeneration.

Arthritis↗
PubMed1995

[Neoadjuvant intralesional chemotherapy for breast neoplasm in advanced stage. Assessment of its efficacy with Doppler color].

Twenty women with breast cancer confirmed at cyto-histology, 4 of them with axillary lymph node metastases, were submitted to neo-adjuvant chemotherapy with the conventional systemic treatment combined with intralesion drug administration and monitored by means of color-Doppler ultrasonography (CDU). Before treatment, CDU demonstrated marked color signal increase in 18 cases. After treatment, tumor vascularity clearly decreased and response was more apparent since treatment had been local rather than systemic. In this paper, the consistent semiology of breast cancer is discussed together with the progressive changes in CDU color signal, the latter a valuable parameter for surgical timing. Histology, performed during treatment and on the surgical specimen, allowed treatment results to be monitored, showing a rich proliferation of connective tissue and the persistence of rare neoplastic nests. In 2/4 patients with lymph node metastases, the latter lesions reduced in size. The postoperative follow-up of these patients, which was the object of our study, currently ranges 4 to 36 months, in which period of time no relapses have been observed. The results obtained so far suggest the effectiveness of combined parenteral and local drug administration in the preoperative treatment of breast cancer. Moreover, this approach makes surgery feasible even in the most advanced forms (T3-T4). CDU is the most accurate method to monitor neo-adjuvant treatment effectiveness.

Aged↗
PubMed1995

[Biomechanics and semeiotics of traumatic lesions of the posterior cruciate ligament using magnetic resonance].

The authors reviewed 458 MR examinations of the knee to assess the potentials of this technique in the study of traumatic injuries of the posterior cruciate ligament (PCL) and to investigate the frequency of their association with injuries of other knee joints. MR images were acquired with an 0.5-T super-conductive unit with an extremity coil. T1-weighted spin-echo (SE) and T2*-weighted gradient-echo (GE) sequences were used on sagittal, coronal and, in some cases, axial planes, with 3-mm slice thickness and 0-1 mm slice gap. The following parameters were studied to diagnose partial or complete PCL tears: PCL thickness and outline, disruption of ligamentous fasci and signal intensity features. The injuries were classified as proximal, intermediate and distal according to their site. Thirteen PCL tears were detected, 5 of them complete and 8 partial. Complete tears were found in 4/5 patients in the middle third and one patient had a distal intersection tear with tibial bone avulsion. Partial tears were found in the distal tract in 5/8 patients, in the proximal tract in one patient and in the middle third in 2 patients. In 12/13 patients capsuloligamentous knee tears were associated. Overall MR rate of PCL tears was 2.8%; of them, 92.3% were associated with other capsuloligamentous injuries. MR diagnosis was confirmed at arthroscopy in 12/13 patients. The sagittal plane was best in optimally demonstrating the whole PCL and its injuries. GE T2* sagittal sequences demonstrated the site of PCL tears better than SE sagittal ones. Relative to other authors, we found MRI an extremely reliable method to distinguish partial from complete PCL tears. This was probably due to the thinner slices (3 mm) we used. MRI can accurately assess the extent of traumatic injuries of the PCL and of other capsuloligamentous parts of the knee, which is relevant from the clinical point of view. Indeed, MRI allows useless diagnostic arthroscopy to be avoided and yields major indications to choose the correct treatment.

Adult↗
PubMed1990

[Short- and long-term effects of enalapril on the left ventricular function in patients with congestive heart insufficiency].

Several studies have demonstrated that enalapril causes a clinical and hemodynamic improvement in patients with congestive heart failure. Nevertheless, the drug capability of influencing left ventricular systolic and diastolic indexes has not been evaluated. In 12 patients with severe congestive heart failure (NYHA class III-IV), treated with digitalis and diuretics, we performed a baseline evaluation through a right heart catheterization, echocardiography and radionuclide ventriculography. The effects on left ventricular systolic and diastolic function indexes after the administration of enalapril 5 mg by oral route have been evaluated. After 3 months of chronic therapy with enalapril 5 mg twice daily, we performed a further evaluation through echocardiography and radionuclide ventriculography. At the acute test we observed a significant improvement of left ventricular ejection fraction (EF), left ventricular stroke index (LVSI), and peak of filling rate (PFR), with a significant reduction of pulmonary wedge pressure (PWP) and peripheral vascular resistance (PVR). After 3 months of chronic therapy EF was significantly increased with respect to baseline values (37 +/- 6.9% vs 28.7 +/- 7.9%, p less than 0.05) and showed a further increase after the drug administration (from 37 +/- 6.9% to 48 +/- 5.4%, p less than 0.001). PFR showed a similar behaviour and reached at the follow-up evaluation normal values (from 1.97 +/- 0.7 edv/s to 2.57 +/- 0.6 efv/s, p less than 0.001). Furthermore, the echocardiographic dimensions of the left ventricle decreased significantly with a significant increase of shortening fraction. In conclusion, our study demonstrates that in patients with severe congestive heart failure enalapril improves the left ventricular systolic and diastolic function indexes and this improvement is persistent.

Aged↗