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Biomedical subjects

G Privitera

Publications and source records attributed to G Privitera.

At least 19 recordsLinked to original sources

Cellular and molecular effects of protons: apoptosis induction and potential implications for cancer therapy.

Due to their ballistic precision, apoptosis induction by protons could be a strategy to specifically eliminate neoplastic cells. To characterize the cellular and molecular effects of these hadrons, we performed dose-response and time-course experiments by exposing different cell lines (PC3, Ca301D, MCF7) to increasing doses of protons and examining them with FACS, RT-PCR, and electron spin resonance (ESR). Irradiation with a dose of 10 Gy of a 26,7 Mev proton beam altered cell structures such as membranes, caused DNA double strand breaks, and significantly increased intracellular levels of hydroxyl ions, are active oxygen species (ROS). This modified the transcriptome of irradiated cells, activated the mitochondrial (intrinsic) pathway of apoptosis, and resulted in cycle arrest at the G2/M boundary. The number of necrotic cells within the irradiated cell population did not significantly increase with respect to the controls. The effects of irradiation with 20 Gy were qualitatively as well as quantitatively similar, but exposure to 40 Gy caused massive necrosis. Similar experiments with photons demonstrated that they induce apoptosis in a significantly lower number of cells and in a temporally delayed manner. These data advance our knowledge on the cellular and molecular effects of proton irradiation and could be useful for improving current hadrontherapy protocols.

Apoptosis↗

Three scenarios of clinical claim reimbursement for nosocomial infection: the good, the bad, and the ugly.

We studied the extent to which hospitals can expect to receive reimbursement for costs relating to nosocomial infections (NI) under the diagnosis-related groups (DRG) system of clinical claims and calculated the loss of reimbursement due to missed or incorrect registration of infective complications on hospital discharge records (HDR). We calculated clinical claim reimbursement in three scenarios: the good, in which all NI are recorded on HDR; the bad, in which a proportion of NI recorded on HDR observed at the 41 participating hospitals; the ugly, in which none of the NI are recorded on HDR. We analysed in which patients the recording of infective complications changed the DRG clinical claim and the economic consequences on reimbursements. Compared with the ugly scenario, the bad scenario, which is closest to what actually occurs, with only 55.9% of NI (180/322) properly recorded, produced an increased DRG clinical claim in 30 cases, of on average 403 for every NI. Compared with the ugly scenario, the good scenario, produced an increased DRG clinical claim in 45 cases with an average reimbursement of 618. The difference between the bad and the good scenarios shows an average loss of 215 for every case. Our calculated good scenario could cover only 3.8% of direct costs per case attributable to NI. Real, tangible benefits in health, both social and economic, will only accrue from the monitoring and control of NI in hospitals.

Cross Infection↗

Aetiology and prognosis of bacteraemia in Italy.

A prospective multi-centre study was conducted to assess the microbiological pattern and prognostic factors of bacteraemia and their impact on clinical outcome. All patients admitted to 41 Italian hospitals over 2 months, from whom one or more clinically significant organisms were isolated from blood culture, were studied according to a standardized protocol and case definition. A total of 156 episodes of bacteraemia were identified in 20,601 patients. There were 3.9 episodes of nosocomially acquired bacteraemia and 3.7 episodes of community-acquired bacteraemia per 1000 admissions. The most frequent pathogens isolated were Gram-negative bacteria (44.9%) but Gram-positive species accounted for 40.4 % of episodes. Fungal infections due to Candida spp. were found in 3.8 % of episodes, and multiple pathogens were recovered from 9.6% of episodes. The clinical response to bacteraemia was classified as sepsis in 90 episodes (577%), severe sepsis in 21 (13.5%) and septic shock in 26 (167%); 19 episodes (12.2%) showed no clinical response. The total in-hospital mortality was 25.0%. By multivariate logistic regression, the variables which independently predicted mortality were increasing age, the presence of septic shock, infection with Gram-positive bacteria or fungi and nosocomial acquisition.

Adolescent↗

Prevalence of nosocomial infections in Italy: result from the Lombardy survey in 2000.

A one-day survey was carried out in 88 out of 113 public hospitals in Lombardy to obtain prevalence rates of hospital-acquired infections (HAIs) by hospital departments and to identify the pathogens more frequently involved. In total 18667 patients were surveyed, representing 72% of the average daily total of occupied beds in public hospitals in Lombardy. The overall prevalence of HAI was 4.9%. The highest prevalence was observed in intensive care units and in spinal units. The prevalence of bloodstream infections was 0.6%; pneumonia 1.1%; urinary tract infections 1.6% and gastrointestinal infections 0.4%. In surgical patients the prevalence of surgical site infections was 2.7%. The most frequently isolated pathogen from all sites of infections was Escherichia coli (16.8%), followed by Staphylococcus aureus (15.0%), Pseudomonas aeruginosa (13.2%) and Candida spp. (8.7%). Methicillin-resistant S. aureus accounted for 23% of all isolated S. aureus. The results provide baseline data for rational priorities in allocation of resources, for further studies and for infection control activities.

Candidiasis↗

Prevalence and patterns of antibiotic prescribing in Italian hospitals.

Use of antimicrobial drugs is associated with the emergence of resistant bacteria, increasing hospital expenditures and requires an assessment of appropriateness. The aim of this study was to investigate prevalence and patterns of antibiotic prescribing and expenditures in Italian hospitals. A prevalence survey was performed in 15 Italian hospitals. Data on antimicrobial use and expenditures in the year 2000 and 1-day point prevalence information on antibiotic prescription, type and sources of infections and expenditures were obtained through a review of pharmacy records and charts of 2,165 inpatients. 45.5% of the patients surveyed were receiving at least one antibiotic: 148 for hospital-acquired infections (HAI), 262 for community-acquired infections (CAI). No active infection was recorded for 575 patients (58.4%). 57.3% of prescriptions for HAI and 65.9% for CAI were based on empiric and presumptive criteria, while 39% of HAI and 15.8% of CAI were oriented by microbiology and susceptibility testing results. Guidelines were followed in choosing the antimicrobial drugs for 22.8% of therapeutic and 46.8% of prophylactic courses. High rates of antibiotic usage were observed in Italian hospitals. Areas for improvement, both for the use of diagnostic resources and the prescribing habits, were identified. The 1-day prevalence survey of antimicrobial use may be a tool of feedback to prescribers for more appropriate drug selection.

Anti-Bacterial Agents↗

Totally implantable venous access devices implanted surgically: a retrospective study on early and late complications.

BACKGROUND: The techniques used for the implantation of totally implantable venous access devices (TIVADs) are the percutaneous approach and surgical cutdown; however, the choice is still controversial. HYPOTHESIS: The surgical cutdown approach may be beneficial to reduce the rate of complications. DESIGN: Retrospective review. SETTING: A university hospital and a tertiary referral center. PATIENTS: Patients undergoing a TIVAD implant at the First Surgical Clinic of the University of Catania in Catania, Italy, between January 1995 and December 1999, were considered for the study. All of the devices were implanted in an operating room under fluoroscopic control. The vein of choice was the cephalic vein. When the cephalic vein was not suitable for implantation, the external jugular vein or the axillary vein and its branches were used. The percutaneous approach to the subclavian vein or internal jugular vein was considered a last resort to implant a catheter. RESULTS: During the study period, 346 TIVADs were implanted in 344 patients. The procedure was performed with local anesthesia in 341 cases (98.5%), and only 2 patients (0.6%) required sedation for psychological reasons. Three patients (0.9%) had their TIVAD placed during a laparotomy. In 326 patients (94.2%), the devices were implanted in the cephalic vein. In the remaining cases, other veins were used with surgical cutdown. The mean time for the procedure was 15 minutes. Percutaneous access was never used, and no early mechanical complications were recorded. Only 6 patients (1.8%) in our study group had late complications (1 case of migration of the catheter, 2 cases of infection, and 3 cases of withdrawal occlusion). The catheter life ranged from 6 to 1487 days (mean time, 348 days). CONCLUSION: Our results confirm the safety, speed, and low cost of the open cutdown technique. This surgical procedure avoids both early and late complications that frequently occur with percutaneous access. Surgical cutdown should be considered the technique of choice to implant the TIVAD, especially in cancer patients.

Adult↗

Cefotaxime in the treatment of prophylaxis of surgical infections.

Cefotaxime has retained its broad-spectrum activity against the key pathogens in surgical infection, despite 15 years of widespread use. It has good activity against a wide range of Gram-positive and Gram-negative aerobes and most anaerobes, except Bacteroides fragilis but, combined with metronidazole, it offers clinically complete coverage of B. fragilis and Escherichia coli, the two most important species involved in intra-abdominal infections. For mixed infections involving B. fragilis, 500 mg metronidazole 12-hourly should be added to the cefotaxime regimen. Cefotaxime therapy is simple, generally inexpensive and has a relatively broad spectrum of activity compared to many other antimicrobials used for postoperative nosocomial pneumonia. Treatment with cefotaxime at 1 g or 2 g can be 12-hourly. Surgical prophylaxis with single-dose cefotaxime (1 g or 2 g) is as effective as with many other agents, with no documented selection of resistance. Clinical experience gained worldwide strongly supports the use of cefotaxime for the treatment of prophylaxis and surgical infections.

Bacterial Infections↗

Postoperative enteral feeding does not prevent intestinal bacterial translocation, but reduces the rate of pulmonary infections in pigs undergoing total orthotopic small bowel transplantation.

OBJECTIVE: To assess the effects of a non-elemental liquid diet on nutritional state, composition of bowel flora, intestinal translocation, and pulmonary infections after small bowel transplantation in pigs. DESIGN: Prospective randomised experiment. SETTING: Teaching hospital, Italy. MATERIAL: 32 female Large White pigs. INTERVENTIONS: Group 1 (n = 6) underwent small bowel transplantation, were treated with immunosuppression, and fed on commercial chow. Group 2 (n = 6) were treated similarly except that they were fed with an enteral feed through a tube gastrostomy starting on day 4 postoperatively. Group 3 (n = 6) were treated similarly to group 1 except that they had no immunosuppression, and Group 4 (n = 6) underwent orthotopic small bowel autotransplantation; 8 further pigs underwent a sham operation only to act as controls. MAIN OUTCOME MEASURES: Signs of rejection, graft-versus-host-disease, luminal bacterial overgrowth, bacterial translocation, pneumonia, and the pigs' nutritional state. RESULTS: All animals in group 3 showed signs of acute rejection. There was appreciable overgrowth of aerobic and anaerobic bacteria in all three groups after allotransplantation compared with controls. The counts of anaerobic bacteria were significantly lower in group 2 (enterally fed animals) compared with those given free access to commercial chow [mean (SD) 2.81 (1.39) log CFU/cm2 compared with 4.80 (1.65), p = 0.047]. Bacterial translocation developed to a similar degree after autografts and allografts and pneumonia developed in fewer animals after enteral feeding (1/6) than after conventional feeding (5/6) but the difference was not significant (p = 0.08, odds ratio 25.0, 95% confidence interval of odds ratio 1.20 to 521.13). Enterally fed animals also lost less weight than conventionally fed animals [2.32 (1.23) kg compared with 4.53 (1.74), p = 0.016]. CONCLUSIONS: Enteral feeding for up to a month slightly reduced the rate of pneumonia and resulted in a better nutritional state in pigs after small bowel transplantation. It had no effect on luminal bacterial overgrowth or translocation.

Animals↗

Parenteral antibiotics and selective intestinal decontamination do not prevent enteric bacterial overgrowth or translocation observed in a swine model of small bowel transplantation.

Alterations in the luminal microflora and increased intestinal translocation have been reported to occur following experimental and clinical small bowel transplantation (SBT). Selective intestinal decontamination (SID) has been used to prevent luminal overgrowth and bacterial translocation. Despite the wide use of SID in clinical SBT, there are no data supporting its usefulness in this situation. Thus, the aim of this investigation was to examine the effects of cyclosporine A (CsA) and SID upon bacterial overgrowth and translocation in a swine model of SBT. Nineteen Large White female pigs weighing 30 +/- 2 kg underwent a total orthotopic SBT and were randomly allocated to one of the following experimental groups as follows: Group 1 (No. 8) CSA 25 mg/kg body weight (b.w.)/day administered subcutaneously and Cefazolin 2 g/day im. Group 2 (No. 6) received the identical immunosuppression but the Cefazolin 2 g/day im was discontinued on the 5th Postoperative Day (pod) and switched to a SID regimen consisting of Vancomycin, 1 g, Nystatin, 500,000 IU, Colistin, 1,500,000 IU, and Tobramycin, 100 mg, given through a gastrostomy tube. Group 3 (No. 5) received no immunosuppression but antibiotic consisting of Cefazolin 2 g im/day. Group 4 (No. 7) underwent a small bowel autotransplantation. Group 4 received SID as in group 2 but no immunosuppression was given. Finally, 17 normal animals were sham-operated and were used as normal controls (N group). The animals in groups 1, 2, and 4 were sacrificed on the 29th pod. Those in group 3 were sacrificed on the 7th pod.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Luminal bacterial overgrowth and intestinal translocation in pigs given either cyclosporin A or 15-deoxyspergualin after small bowel transplantation.

OBJECTIVE: To examine the effects of two immunosuppressant regimens on composition of the bowel flora and rate of translocation after transplantation of the small bowel in pigs. DESIGN: Randomised controlled study. SETTING: University hospital, Italy. MATERIAL: 35 female Large White pigs. INTERVENTIONS: 9 Animals were not operated on (normal controls). 19 Animals underwent total orthotopic small bowel allotransplantation and were then randomised to receive: group A (n = 8) cyclosporin A 25 mg/kg subcutaneously and cephazolin 2 g intramuscularly daily; group B (n = 6) 15-deoxyspergualin (15-dos) 3 mg/kg for 7 days then 1.5 mg/kg, cephazolin 2 g intramuscularly daily for 4 days then selective intestinal decontamination with colistin 1.5 million U, tobramycin 100 mg, vancomycin 1 g, and nystatin 500,000 U daily; and group C (n = 5) cephazolin 2 g intramuscularly daily for 8 days. A further group (D, n = 7) underwent orthotopic autotransplantation and received the same antibiotic and selective decontamination regimens as group B. Animals in group C were killed on day 8, and the rest on day 29. MAIN OUTCOME MEASURES: Signs of rejection, graft versus host disease, luminal overgrowth, and evidence of translocation to mesenteric lymph nodes. RESULTS: All animals in group C, and 2 in group B, showed signs of acute rejection. There was a significant overgrowth of both aerobic and anaerobic bacteria in all 3 groups after allotransplantation compared with normal controls. Bacterial translocation was similar in autografted and allotransplanted animals. Mesenteric lymph nodes were colonised in 4/9 controls, 7/8 in group A, 4/4 in group B, 5/5 in group C, and 7/7 in group D. CONCLUSION: Neither cyclosporin A nor 15-dos prevented luminal overgrowth or bacterial translocation to mesenteric nodes up to one month after operation. The rate of translocation was similar in autotransplantation and allotransplantation, suggesting that non-immunological factors (for example, denervation and interruption of lymphatics) may have a role in these alterations.

Animals↗

Penicillin resistance among Streptococcus pneumoniae in Europe.

Penicillin resistance in Streptococcus pneumoniae, which has been occasionally described in European isolates since the early 1970s, presently constitutes a general problem, although its rate may vary largely between countries and areas. Spain and Hungary show the highest rates of resistance and were probably the starting point for further dissemination to adjacent and distant countries. In Europe, resistant strains belong predominantly to serotypes 6, 9, 14, 19, and 23, and are isolated more frequently from pediatric than from adult patients, and from respiratory and CSF samples rather than blood. Although penicillin resistance in pneumococci is usually a well-recognized problem, some difficulties, mainly related to methodologic aspects of in vitro susceptibility testing, still subsist for its proper surveillance, but may be overcome through the adoption of adequate diagnostic protocols and tools.

Adult↗