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Biomedical subjects

L Lazzarini

Publications and source records attributed to L Lazzarini.

At least 19 recordsLinked to original sources
PubMed2006

Experimental osteomyelitis: what have we learned from animal studies about the systemic treatment of osteomyelitis?

Clinical trials of systemic antibiotic treatment of osteomyelitis are difficult to perform for many reasons, such as low incidence rate of osteomyelitis, variety of anatomic locations, stage and etiologic agents. In this article, we reviewed the experimental studies on osteomyelitis available in the English medical literature since 1968, to ascertain their actual and potential impact on the treatment of human osteomyelitis. Major results are summarized and topics of major interest, such as reproducibility of animal models, predictive value of animal models, correlation of pharmacokinetics between different animals and humans, and the correlation of outcome between animal and clinical studies are discussed. Most of the reviewed animal models are reproducible and dependable. However, establishing the right dose regimen in animals appeared a critical factor, which might undermine the predictive value of the experimental study. Due to difficulties in comparing results of animal and human studies, the predictive value of animal studies about osteomyelitis is still unclear. However, animal models gave valuable information to the clinician for choosing the minimal duration of antibiotic treatment. Even though the use of antibiotic combinations was associated with better outcome in the majority of animal studies, such a finding seems to have limited impact on clinical practice.

Animals↗
PubMed2005

Human leptospirosis in the Vicenza area (Italy) from 1990 to 2003: an epidemiological and clinical study.

All cases of human leptospirosis observed at the S. Bortolo Hospital, Vicenza, Italy, in the period from September 1990 to December 2003 were retrospectively reviewed. The aim of the study was to define the epidemiological, clinical, diagnostic, and therapeutic aspects of this infection and to compare these with an earlier local study (1979-1990) in order to assess if any changes have occurred over time. The screening test was made using macroscopic agglutination and the diagnosis was definitively confirmed using the microscopic agglutination test (MAT). The etiological serotype was identified in 13 patients (68%) and Leptospira poi was the most frequent serovar. Hepatic and renal involvements were present in a high percentage of patients (71% and 74%, respectively), cardiac involvement in 39%, and hypertriglyceridemia and hepatic steatosis were observed in 68% and 43% of cases, respectively. One patient died because of acute renal and respiratory failure. Intravenous penicillin was the treatment of choice. A consistent reduction in the prevalence was observed during the time period of this study (n = 38) compared with the previous period (n = 86); males were more affected than females in both time periods. In industrialized countries the prevalence of leptospirosis is decreasing; nevertheless, this infection is no longer limited to specific occupational groups and remains a potential fatal disease that should be included in the differential diagnosis of all the patients with unexplained fever.

Adult↗
PubMed2004

Clostridial orthopedic infections: case reports and review of the literature.

Clostridia are anaerobic Gram-positive bacilli that can be isolated from the soil and the intestinal tract of humans. These microorganisms are recognized as the cause of devastating soft tissue infections, such as cellulitis, myositis, and gas gangrene. However, such bacteria may also be involved in various postoperative orthopedic infections, including prosthetic joint infection. We present three clinical cases of clostridial orthopedic infection and review the related medical literature.

Adult↗
PubMed2002

Mycobacterium tuberculosis and Mycobacterium fortuitum osteomyelitis of the foot and septic arthritis of the ankle in an immunocompetent patient.

Mycobacteria, both tuberculous and nontuberculous, are recognized as a cause of chronic bone and joint infection. However, the diagnosis of mycobacterial infection is easily missed because of the absence of systemic involvement. Moreover, specific microbiologic techniques are required to detect mycobacteria in clinical specimens. Infections due to uncommon pathogens such as mycobacteria are more likely to occur in the immunocompromised host. A case of septic arthritis of the ankle and osteomyelitis of the foot due to both tuberculous and nontuberculous mycobacteria in an immunocompetent host is reported here.

Adult↗
PubMed2002

Three-times weekly teicoplanin in the outpatient treatment of acute methicillin-resistant staphylococcal osteomyelitis: a pilot study.

Treatment of osteomyelitis requires prolonged hospital stay, lengthy antibiotic therapy and adequate surgical debridement. Outpatient parenteral antibiotic therapy (OPAT) is a new approach to reduce patient discomfort and hospital costs. Teicoplanin, a glycopeptide antibiotic with a long half-life (72 hours), is one of the most useful drugs for OPAT. We performed a pilot study to assess the safety and efficacy of three-times weekly teicoplanin in the treatment of methicillin-resistant (MR) acute staphylococcal osteomyelitis. Ten patients with acute post-traumatic osteomyelitis were enrolled. Pathogens were MR Staphylococcus aureus (5 patients) and MR coagulase-negative staphylococci (5 patients). After a loading dose of 400 mg b.i.d. for 3 days, patients were treated with an intravenous dose of 1000 mg on Mondays and Wednesdays and with a 1200 mg dose on Fridays. Teicoplanin trough levels were maintained within a 10 to 20 mg/L range. If hardware removal had been possible at enrollment, treatment was carried out for at least 4 weeks. If, on the contrary, hardware removal had not been possible, teicoplanin was administered as suppressive therapy until hardware removal. Treatment was successfully performed in 9 out of 10 patients, whereas in one patient only improvement was achieved. Side effects were not recorded. Three times weekly teicoplanin seems to be a valuable option in the treatment of acute MR staphylococcal osteomyelitis. Further studies are warranted in order to better define the role of this new administration schedule in this field.

Acute Disease↗
PubMed2002

The application of cost effectiveness analysis to derive a formulary for urinary tract infections.

According to economic principles an inappropriate prescription is the choice of an antimicrobial with higher/equivalent cost and lower effectiveness (or higher cost and equivalent/lower efficacy) than an alternative (in this case, the former is specified as a "dominated" drug). To identify cost-effective antibiotics we applied the principles of incremental cost-effectiveness analysis (ICEA) to microbiological data of San Bortolo Hospital. Its 27 wards were grouped in 9 functional areas. The resistance patterns of 8 urinary pathogens in the 1997 microbiology data base were assessed. The measure of antibiotic effectiveness was expressed as the percentage of isolates susceptible to each antibiotic tested. The difference in cost (i.e. the incremental change) between each antibiotic and the next more expensive alternative was calculated, and compared with the incremental change in effectiveness. Calculations were made for each pathogen. The antibiotics remaining after exclusion of all "dominated" antibiotics were pooled on a list defined as "Specific Area Formulary". The implications of the use of economic principles within a general antimicrobial policy are discussed.

Anti-Bacterial Agents↗
PubMed2001

Social "status" and biological "status": a comparison of grave goods and skeletal indicators from Pontecagnano.

Comparison of funerary treatment and skeletal biology can be very informative about the interplay of social status and meanings and actual life conditions in ancient communities, but such comparison is rarely done, due in part to the disciplinary separation of bioanthropology and social archaeology in many archaeological traditions. In this paper, we analyze relations between skeletal pathologies and grave goods in a sample of 94 individuals from Pontecagnano (Salerno, Italy, seventh-third centuries BC). The results show that the relationship between health, activity, and social status as expressed in grave goods was complex. Some biological indicators considered typical of "stress" or biological status (enamel hypoplasia, cribra orbitalia, adult stature) bore no relation to social status. Other indicators, particularly those of activity and stress in adult life (trauma, Schmorl's nodes, periostitis), covaried with grave assemblage and help to outline a possible division of labor. As this analysis shows, when skeletal and archaeological data are used in conjunction, the result is a deeper picture of the social and economic life of the community than can be obtained from either source.

Adult↗
PubMed2001

Postoperative infections following total knee replacement: an epidemiological study.

From January 1991 to June 1997 217 patients undergoing monolateral or bilateral total knee replacement (TKR) were consecutively enrolled in a prospective study on the incidence of postoperative infections and related risk factors. Regional antimicrobial prophylaxis (teicoplanin 400 mg) was used in 263 (95%) prostheses implanted; in the remaining 14 implants (5%) perioperative antibiotic prophylaxis (teicoplanin 800 mg) was administered as usual by systemic route. None of the patients experienced local or systemic adverse effects. Over the 2-year follow-up period, 8 (2.9%) primary site infectious complications were recorded, i.e. 4 superficial infections, which were cured without involvement of the prostheses, and 4 deep infections, which required prosthesis removal. Six infections occurred in patients who had undergone previous surgery of the same knee joint, and 2 in patients undergoing primary TKR (p= 0.0005); diabetic patients had infections (13%) more frequently than non-diabetic patients (1.9%, p=0.01). Staphylococci were the leading organisms isolated from infections; however 3 strains of Escherichia coli were isolated from patients who had undergone a previous prosthesis implantation at the same knee joint. Regional administration of teicoplanin appears to be a safe and valuable prophylactic technique; however, in patients at risk of infection a prophylactic regimen which is also active against gram-negative bacteria should probably be considered.

Adult↗
PubMed2000

Nosocomial candidemia in non-neutropenic patients at an Italian tertiary care hospital.

In a retrospective study conducted in an Italian tertiary care hospital, the incidence of nosocomial candidemia was evaluated together with causative pathogens, treatment, and risk factors for death. Over a 6-year period (1992-1997), a total of 189 episodes of candidemia occurred in 189 patients (mean age 58+/-19 years), accounting for an average incidence of 1.14 episodes per 10,000 patient-days per year. The most common reasons for hospitalization were solid neoplasia (21%), trauma (17%), abdominal diseases requiring surgery (13%), and cardiovascular diseases (13%). No patient was neutropenic within 3 weeks prior to the onset of candidemia. One hundred thirty patients were hospitalized in intensive care units, 47 patients in surgical wards, and 12 patients in medical wards. Candida albicans was the most frequently isolated pathogen, accounting for 54% of fungal isolates, followed by Candida parapsilosis (23%), Candida glabrata (7%), Candida tropicalis (5%), Candida pelliculosa (4%), Candida lusitaniae (1%), Candida humicula (1%), and other non-albicans Candida spp. (5%). Seventy-six (41%) patients received adequate antifungal therapy. Seventy-one (58%) of the 123 evaluable patients with central venous catheters underwent line removal; 51 of them had catheter-related candidemia. The 30-day crude mortality rate was 45%. Older age, hospitalization in an intensive care unit, a longer duration of candidemia, retention of central lines, and inadequate antifungal therapy were significantly associated with poor outcome. In the present study, nosocomial candidemia was a frequent and relatively underestimated illness. Adequate antifungal therapy and central line removal independently reduced the high mortality of the disease.

Adolescent↗
PubMed2000

Antiphase disorder in GaAs/Ge heterostructures for solar cells

Antiphase disorder in metal organic vapour phase epitaxy grown GaAs/(100)Ge heterostructures has been studied both in as-grown materials and in GaAs solar cells by chemical etching, transmission electron microscopy, and cathodoluminescence. All the samples are single domains at the surface due to the self-annihilation of antiphase domains whose size decreases as the misorientation angle increases. Completely antiphase domain-free epitaxy has been achieved for substrate miscuts greater than 3 degrees off towards [111]. A reversal in sublattice location has been found in the GaAs layers varying the misorientation angle and the growth temperature. A model to explain this result has been proposed based on the role of surface steps in the nucleation process. Strong interaction between antiphase boundaries and misfit dislocations has been found in all the heterostructures. In solar cells antiphase domains have been observed in high densities in the initial layer of GaAs deposited on Ge. The successful realisation of high efficiency solar cells is due to the overgrowth of these domains by single phase material over most of the wafer area.

Journal Article↗
PubMed2000

Low-temperature spectrally resolved cathodoluminescence study of degradation in opto-electronic and microelectronic devices

This study reports on the microcharacterization of devices for optoelectronic and for microelectronic applications using low temperature (T = 5 and 77 K) spectrally resolved cathodoluminescence (SCL). The mechanisms leading to compositional inhomogeneities in the regrowth regions of InP-based butt-coupled laser-waveguide devices for semiconducting optical amplifiers (SOAs) and for defect generation in the active and cladding layers of GaAs based pump lasers for erbium-doped optical fibre amplifiers (EDFAs) were studied. Beryllium outdiffusion in the base regions of GaAs-based heterojunction bipolar transistors (HBTs) after bias ageing was also studied. By comparing the CL results with TEM, SIMS and HRXRD studies and with the existing literature, the observed growth and operation induced defects were attributed, respectively, to the following mechanisms: recombination-enhanced defect glide (REDG) in the pump lasers, recombination enhanced impurity diffusion (REID) in the HBTs and electrostatically induced growth flux instabilities in the butt-coupled laser-waveguide devices.

Journal Article↗
PubMed2000

Successful treatment of Castleman's disease with HAART in two HIV-infected patients.

Castleman's disease is a heterogeneous group of lymphoproliferative disorders of unknown aetiology. Recently, human herpesvirus type 8 (HHV-8) has been associated with various diseases in individuals with HIV infection, including Kaposi's sarcoma, B cell non Hodgkin's lymphomas, and Castleman's disease. In Castleman's disease it has been hypothesized that HHV-8, encoding a number of various virokines, can be responsible for clinical manifestations of the disease.Previously, two reports have described a clinical recovery from HIV-associated Castleman's disease: by administration of a monoclonal antibody neutralizing human IL-6 in one case, and in another case by treatment with highly antiretroviral therapy and anti-herpesvirus therapy, following splenectomy. We report two cases where HAART alone led to clinical recovery from Castleman's disease. In both the cases reported here, although follow-up biopsy was not performed, it is likely that the inhibition of HHV-8 replication and of virokine release, through the restoration of immunity by HAART, was the basis for the disappearance of the clinical symptoms.

Adult↗
PubMed2000

Safety and efficacy of recombinant granulocyte colony-stimulating factor as an adjunctive therapy for Streptococcus pneumoniae meningitis in non-neutropenic adult patients: a pilot study.

Twenty-two non-neutropenic adult patients with Streptococcus pneumoniae meningitis received granulocyte-colony stimulating factor (G-CSF) (300-450 Ig/day subcutaneously for 6 days) in addition to cefotaxime plus dexamethasone (9-12 g/day for 10 days and 16 mg/day for 3 days iv, respectively). Patients recovered without evident sequelae in all cases but one (with bilateral hearing deficit). No adverse event was recorded. Improvement of inflammation indices in the cerebrospinal fluid was rapid. The most rapid improvement was seen in glucose concentration, which returned to normal ranges within 24-48 h of treatment. In this study G-CSF administration appeared to be safe and effective; further controlled clinical trials are justified.

Adult↗
PubMed2000

Linear classification of low-resolution EEG patterns produced by imagined hand movements.

Electroencephalograph (EEG)-based brain-computer interfaces (BCI's) require on-line detection of mental states from spontaneous EEG signals. In this framework, surface Laplacian (SL) transformation of EEG signals has proved to improve the recognition scores of imagined motor activity. The results we obtained in the first year of an European project named adaptive brain interfaces (ABI) suggest that: 1) the detection of mental imagined activity can be obtained by using the signal space projection (SSP) method as a classifier and 2) a particular type of electrodes can be used in such a BCI device, reconciling the benefits of SL waveforms and the need for the use of few electrodes. Recognition of mental activity was attempted on both raw and SL-transformed EEG data from five healthy people performing two mental tasks, namely imagined right and left hand movements.

Adult↗
PubMed2000

Regional prophylaxis with teicoplanin in monolateral or bilateral total knee replacement: an open study.

From January 1991 to June 1997, patients undergoing primary elective monolateral or bilateral total knee replacement (TKR) were consecutively enrolled in a prospective, open clinical study on the efficacy and safety of regional prophylaxis with teicoplanin (TEC). Those scheduled for monolateral TKR (115 patients) received 400 mg of TEC in 100 ml of saline as a 5-min infusion into a foot vein of the leg to be operated on immediately after the tourniquet was inflated to 400 mm Hg (ca. 50 kPa). For patients undergoing bilateral surgery (45 patients), regional administration of TEC was also repeated for the second knee operation. Follow-up ranged from a minimum of 2 years to 8 years. None of the patients experienced local or systemic adverse effects following regional administration of TEC. In the immediate postoperative and 2-year follow-up periods, only one superficial infection of the primary site attributable to intraoperative contamination (prophylaxis failure) out of the 205 prostheses implanted was observed. Deep infections involving the prosthesis did not occur. Infectious complications at distant sites were observed in nine cases (urinary tract infection due to Escherichia coli in eight cases, and Salmonella enteritidis gastroenteritis in one case) in the immediate postoperative period; they all were rapidly cured after antibiotic treatment. A delayed prosthetic infection, related to hematogenous spread of the etiological agent and therefore not considered a prophylactic failure, was observed in a patient who had undergone TKR 5 years before. Regional administration of TEC in monolateral and bilateral TKR appears to be a safe and valuable prophylactic technique.

Adult↗