Search PubMed⌕ Search

Biomedical subjects

G Pellizzer

Publications and source records attributed to G Pellizzer.

At least 19 recordsLinked to original sources
PubMed2005

Linkage of microbiology reports and hospital discharge diagnoses for surveillance of surgical site infections.

Surveillance of surgical site infections (SSIs) with feedback to surgical personnel is pivotal in decisions regarding infection control. Prospective surveillance is time and resource consuming, so we aimed to evaluate a method based on data collected routinely during care delivery. The study was carried out at three acute hospitals in North-eastern Italy, from 1 January 2001 to 31 December 2001. Hospital discharge diagnoses (selected codes from the International Classification of Diseases, 9th Revision--Clinical Modification) and electronic microbiology reports (positive cultures from surgical wounds and drainages) were linked to identify suspected SSIs. A random sample of tracked events was submitted to total chart review in order to confirm the presence of SSIs retrospectively according to Centers for Disease Control and Prevention definitions. Of 865 suspected SSIs, 64.5% were identified from the microbiological database, 27.1% from discharge codes, and 8.4% from both. Four hundred and three admissions were sampled for review; the overall positive predictive value was 72% (95%CI=69-76%). Since inpatient individual antibiotic exposure is not registered in Italy, the combined use of discharge codes and microbiology reports represents the most feasible automated method for surveillance of SSIs developing during hospital stay.

Cross Infection↗
PubMed2001

Deep tissue biopsy vs. superficial swab culture monitoring in the microbiological assessment of limb-threatening diabetic foot infection.

AIMS: The results of ulcer swabbing vs. deep tissue biopsy have been compared prospectively in 29 diabetic patients with limb-threatening foot infection, to investigate the effectiveness and reliability of each method, and to evaluate whether any of the two could be more suitable for the microbiological follow-up of severe lesions. METHODS: Microbiological samples were collected by using both methods at fixed intervals after therapy commencement (i.e. at day 0, 7, 14, and 30). Statistical comparison was performed between the results of each sampling procedure after the end of follow-up. RESULTS: At enrolment, the mean number of isolates per patient was 2.34 by swabbing and 2.07 by tissue biopsy sampling; the rate of isolation for anaerobes with the two methods was 35% and 25%, respectively; no statistical differences could be observed between the two procedures in terms of either species or frequency of isolation. Anaerobic species were never detected after the first 2 weeks of appropriate treatment, and those ulcers which were still active at day 30 yielded almost exclusively Gram-positive bacteria. At the end of follow-up, deep tissue cultures appeared to exhibit a higher diagnostic sensitivity with respect to swabs. CONCLUSIONS: Swabbing and deep tissue cultures appear to be equally reliable for the initial monitoring of antimicrobial treatment in severe diabetic foot infection. However, our experience seems to suggest that deep tissue might be more sensitive than swabbing for monitoring those isolates that have been selected for antibiotic resistance, i.e. those from ulcers that are still active after 30 days of treatment.

Adult↗
PubMed2001

Randomized prospective controlled trial of recombinant granulocyte colony-stimulating factor as adjunctive therapy for limb-threatening diabetic foot infection.

Adult diabetic patients admitted to our Diabetes Center from September 1996 to January 1998 for severe, limb-threatening foot infection were consecutively enrolled in a prospective, randomized, controlled clinical study aimed at assessing the safety and efficacy of recombinant human granulocyte colony-stimulating factor (G-CSF) (lenograstim) as an adjunctive therapy for the standard treatment of diabetic foot infection. Forty patients, all of whom displayed evidence of osteomyelitis and long-standing ulcer infection, were randomized 1:1 to receive either conventional treatment (i.e., antimicrobial therapy plus local treatment) or conventional therapy plus 263 microg of G-CSF subcutaneously daily for 21 days. The empiric antibiotic treatment (a combination of ciprofloxacin plus clindamycin) was further adjusted, when necessary, according to the results of cultures and sensitivity testing. Microbiologic assessment of foot ulcers was performed by both deep-tissue biopsy and swab cultures, performed at enrollment and on days 7 and 21 thereafter. Patients were monitored for 6 months; the major endpoints (i.e., cure, improvement, failure, and amputation) were blindly assessed at weeks 3 and 9. At enrollment, both patient groups were comparable in terms of both demographic and clinical data. None of the G-CSF-treated patients experienced either local or systemic adverse effects. At the 3- and 9-week assessments, no significant differences between the two groups could be observed concerning the number of patients either cured or improved, the number of patients displaying therapeutic failure, or the species and number of microorganisms previously yielded from cultures at day 7 and day 21. Conversely, among this small series of patients the cumulative number of amputations observed after 9 weeks of treatment appeared to be lower in the G-CSF arm; in fact, only three patients (15%) in this group had required amputation, whereas nine patients (45%) in the other group had required amputation (P = 0.038). In conclusion, the administration of G-CSF for 3 weeks as an adjunctive therapy for limb-threatening diabetic foot infection was associated with a lower rate of amputation within 9 weeks after the commencement of standard treatment. Further clinical studies aimed at precisely defining the role of this approach to this serious complication of diabetes mellitus appear to be justified.

Adjuvants, Immunologic↗
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

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↗
PubMed2000

Role of antigenemia assay in the early diagnosis and treatment of CMV infection in renal transplant patients.

AIM: CMV antigenemia by direct pp65 antigen detection and quantification was monitored on a weekly basis during the first 3 months after kidney transplantation. SUBJECTS AND METHODS: Preemptive therapy with ganciclovir was started according to the following criteria: any positive antigemia in CMV-NEG subjects, a single determination > or = 30 cell or a two fold increase of positive cells in two consecutive specimens in CMV-POS and continued until pp65 was cleared. Overall, 109 patients were monitored. RESULTS: Among the 24 CMV-NEG patients, 13 (54%) developed a pp65 positive assay without symptoms and were treated. Ten patients remained CMV-infection free and one patient developed late onset (7 months) CMV disease (hepatitis). Among the 85 POS patients 15 (17%) developed a pp65 positive assay and were treated. Two of them developed CMV disease within 7 days of the onset of positive antigenemia and 13 were asymptomatic. The other 70 patients remained CMV-infection free. The interval between transplant and the onset of CMV infection was 39 +/- 13 days in the CMV-NEG group and 64 +/- 20 days in the CMV-POS group (p < 0.001). The peak antigenemia level was 193 +/- 175 cells in the CMV-NEG group and 55+/- 78 cells in the CMV-POS group (p < 0.001). The duration of treatment did not differ in the two groups (22 +/- 7days). A second course of therapy, due to a relapse of asymptomatic infection was performed in 11/13 (85%) treated CMV-NEG patients and in 2/15 (13%) treated CMV-POS patients. CONCLUSIONS: Among the total 28 treated patients, we observed only 6 episodes of mild creatinine increase and 9 episodes of mild neutropenia. In the overall population, we observed 8 systemic infections not related to CMV.

Antigens, Viral↗
PubMed1999

Motor cortical encoding of serial order in a context-recall task.

The neural encoding of serial order was studied in the motor cortex of monkeys performing a context-recall memory scanning task. Up to five visual stimuli were presented successively on a circle (list presentation phase), and then one of them (test stimulus) changed color; the monkeys had to make a single motor response toward the stimulus that immediately followed the test stimulus in the list. Correct performance in this task depends on memorization of the serial order of the stimuli during their presentation. It was found that changes in neural activity during the list presentation phase reflected the serial order of the stimuli; the effect on cell activity of the serial order of stimuli during their presentation was at least as strong as the effect of motor direction on cell activity during the execution of the motor response. This establishes the serial order of stimuli in a motor task as an important determinant of motor cortical activity during stimulus presentation and in the absence of changes in peripheral motor events, in contrast to the commonly held view of the motor cortex as just an "upper motor neuron."

Analysis of Variance↗
PubMed1999

Drawing under visuomotor incongruence.

Six human subjects were asked to draw ellipses presented on a screen by moving a manipulandum that controlled the position of a cursor. Six visual templates were used, which comprised three different ellipses displayed either horizontally or vertically; the ratio between the major and minor axes was 2, 4, or 5. For each visual template, the gains were set such that the movement trajectories required to trace the template with the cursor corresponded to one of six ellipses. Thus these movement ellipses were horizontal or vertical with a ratio between major and minor axes of 2, 4, or 5. All 36 combinations of six visual ellipses and six required movement ellipses were used. Therefore, in some conditions the required movement ellipse had a different orientation (with respect to the major axis) than the visual template. These conditions were called orientation incongruent, whereas, when the orientation of the required movement ellipse matched the orientation of the visual template, the conditions were called orientation congruent. Similarly, eccentricity incongruent referred to conditions where the eccentricities of the visual ellipse and the required movement ellipse were different, as opposed to eccentricity congruent. The main results were as follows: (a) The perimeter of the traced ellipse always tended to be larger than that of the visual template. In addition, it was significantly larger in the orientation incongruent conditions than in the orientation congruent conditions. Nevertheless, the perimeter of the traced figure increased with the template in both orientation congruent and incongruent conditions. (b) The shape of the traced figure varied appropriately with the visual template, but differed significantly between the orientation congruent and incongruent conditions. It was closer to the one of the template in the orientation congruent than in the incongruent conditions. Finally, (c) the instantaneous speed was significantly correlated with curvature but more tightly so in the orientation congruent than in the orientation incongruent conditions. The parameters defining the relation between speed and curvature were affected by the required movement ellipse, but not by the particular visuomotor condition. These results showed that although spatial motor performance was affected by changes in the correspondence between visual and movement coordinates, the relation between the speed and curvature of the movement trajectory was stable despite drastic changes in this correspondence.

Adult↗
PubMed1999

Fibrogenesis serum markers in patients with chronic hepatitis C treated with alpha-IFN.

The correlation between therapeutic response and liver fibrogenesis was studied in serum and liver specimens taken from 31 patients treated with alpha-interferon (IFN) (14 sustained responders and 17 non-responders) for chronic hepatitis C. Serum samples, collected before therapy, and at further 6-month intervals over 2 years, were tested for markers of liver neofibrogenesis. Serum N-terminal procollagen III peptide (PIIINP) displayed a significant and persistent decrease (P < 0.05) in sustained responders but not in non-responders; significantly lowered (P < 0.05) mean levels of C-terminal procollagen I peptide (PICP) were transiently observed in both patient groups, apparently as a result of IFN administration. Serum laminin (Lam) levels remained unchanged. One year after the cessation of treatment, liver biopsy re-testing showed an improvement in necro-inflammatory scores only in sustained responders, with the histological fibrosis scores remaining unaltered in both groups. IFN treatment seemed to exert an influence on serum levels of markers of hepatic connective tissue turnover even in patients that did not respond to therapy, while no effect was observed on preexistent liver fibrosis.

Adult↗
PubMed1999

Effect of ursodeoxycholic acid administration in patients with acute viral hepatitis: a pilot study.

BACKGROUND: Ursodeoxycholic acid (UDCA) is able to improve biochemical markers of cholestasis, with a parallel decrease in transaminases, in various cholestatic liver diseases. AIM: To evaluate the effects of UDCA administration on acute viral hepatitis-related cholestasis and the course of acute viral hepatitis. METHODS: Seventy-nine consecutive patients with acute viral hepatitis (HBV: 43, HCV: 11, HAV: 15, HEV: 3, Non A-E: 7) were randomized to receive either UDCA for 3 weeks or no treatment. Liver biochemistry and serum bile acid determinations were run at weekly intervals. RESULTS: No significant differences were observed in mean percentage decreases in transaminases between treated and untreated patients. By contrast, cholestatic indexes decreased significantly more quickly in patients treated with UDCA than in controls, and this effect was more evident in patients with increasing alanine transaminase levels at admission. After a peak at the end of the first week of therapy, serum levels of conjugated ursodeoxycholic acid (CUDCA) showed a gradual decrease. Conjugated cholic acid (CCA) and chenodeoxycholic acid (CCDCA) showed a progressive decrease with the resolution of viral hepatitis, but no influence of UDCA administration was observed. CONCLUSIONS: Our study demonstrates that UDCA significantly improves cholestatic indices in patients with acute viral hepatitis, but this effect does not seem to affect the course of the illness.

Acute Disease↗
PubMed1997

Transformation of the intended direction of movement during continuous motor trajectories.

Chronometric and neurophysiological studies have demonstrated that mentally transforming the intended direction of a pointing movement is a time-consuming process, the duration of which increases with the angle of rotation. If the same time-consuming process occurred while tracing a curved trajectory, it would affect the time course of the movement. The data from subjects drawing simple figures match well the predictions made, and support the hypothesis that a time-consuming process of transformation of the intended movement direction operates during the production of continuous trajectories. This biologically inspired hypothesis provides a functional explanation for the relation between speed of the movement and curvature of the path. In addition, it contrasts with the view of continuous movements as essentially oscillatory motions.

Adult↗
PubMed1996

Visuo-manual aiming movements in 6- to 10-year-Old children: evidence for an asymmetric and asynchronous development of information processes.

Sixty children from 6 to 10 years old participated in an open-loop visuo-manual aiming task (Experiment 1). They were asked to point as fast and accurately as possible toward lateralized visual targets. Responses were wrist flexion-extension movements. Results showed non-monotonic changes with age of constant error, reaction time, and movement time. Constant error for targets presented in the right visual field increased between 6 and 8 years and decreased afterward. Reaction time and movement time decreased with age except at 8 years where they tended to increase. The same subjects participated in two control tasks. One task was designed to test the spatial localization of the lateralized visual targets (Experiment 2). Results showed that subjects localized very accurately the targets at all ages. The second control task was designed to test simple reaction time to the same visual stimuli used in the previous tasks (Experiment 3). Results indicate that reaction time decreased linearly with age when no spatial processing is required for the production of the response. The results of the three experiments showed different developmental functions according to the processes involved in each task. Moreover, they suggest that the conversion from visual to motor coordinates undergo a qualitative change at 8 years of age, and that the prevailing process of this conversion is located in the left cerebral hemisphere.

Age Factors↗
PubMed1996

Intercepting real and path-guided apparent motion targets.

Human subjects were instructed to intercept with a cursor real and apparent motion targets presented on a computer screen. Targets traveled counterclockwise (CCW) in a circle at one of five angular velocities (180, 300, 420, 480 and 540 deg/s), either smoothly (real motion) or in path-guided apparent motion. Subjects operated a computer mouse and were instructed to intercept targets at the 12 o'clock position; there were no constraints on when to initiate the response, which was a movement from the center of the screen towards and past 12 o'clock. We found the following: (a) for both motion conditions and all target velocities, subjects were late in intercepting the target, especially at higher target velocities; (b) for both motion conditions, the directional variability of the response increased as a linear function of the target velocity; (c) the directional variability of the response was systematically higher for the apparent than the real motion condition; there was no significant interaction between target velocity and target motion type; (d) the response time did not vary significantly with velocity, but was consistently longer for apparent than real motion targets; (e) the movement time was very similar for different target velocities; and (f) the moment of initiation of the interception movement was delayed appreciably at higher target velocities, relative to that dictated for perfect interception at a given target velocity. This delay was greater for the apparent motion target. These results demonstrated the following: (a) for both target motion conditions, interception was not fully predictive but lagged the target in spite of the constant target velocity and the unconstrained time allowed for initiating the interception movement; (b) subjects can intercept an apparent motion target but, compared with real motion, the performance is somewhat degraded overall; (c) the similarities in performance between the two target motion conditions, and the fact that target velocity influenced performance in a similar fashion, suggest that the motor system can access the visual information provided by the moving target; and (d) since movement time was similar for different target velocities, the strategy for interception relied on controlling the moment of initiation of the interception movement. This was successful for low target velocities but became unsuccessful at higher target velocities.

Adult↗
PubMed1996

Mental transformations in the motor cortex.

The behavioral and neural correlates of processing of motor directional information are described for two visuomotor tasks: mental rotation and context-recall. Psychological studies with human subjects suggested that these two tasks involve different time-consuming processes of directional information. Analyses of the activity of single cells and neuronal populations in the motor cortex of behaving monkeys performing in the same tasks provided direct insight into the neural mechanisms involved and confirmed their different nature. In the mental rotation task the patterns of neuronal activity revealed a rotation of the intended direction of movement. In contrast, in the context-recall task the patterns of neural activity identified a switching process of the intended direction of movement.

Cues↗
PubMed1995

Motor cortical activity in a context-recall task.

A monkey was trained to respond on the basis of the serial position of a test stimulus in a sequence. First, three stimuli were presented successively on a circle. Then one of them (except the last) changed color (test stimulus) and served as the go signal: The monkey was required to produce a motor response in the direction of the stimulus that followed the test stimulus. When the test stimulus was the second in the sequence, there was a change in motor cortical activity from a pattern reflecting the direction of this stimulus to the pattern associated with the direction of the motor response. This change was abrupt, occurred 100 to 150 milliseconds after the go signal, and was evident both in the activity of single cells and in the time-varying neuronal population vector. These findings identify the neural correlates of a switching process that is different from a mental rotation described previously.

Animals↗
PubMed1995

The mental and the neural: psychological and neural studies of mental rotation and memory scanning.

In this article we review studies pertaining to psychophysical measurements and neural correlates of tasks requiring the processing of directional information in spatial motor tasks. The results of psychological studies in human subjects indicate that time-consuming processes underlie mental rotation and memory scanning. Other studies have suggested that these processes may rely on different basic mechanisms. A direct insight into their neural mechanisms was obtained analyzing the activity of single cells and neuronal populations in the brain of behaving monkeys performing the same tasks. These studies revealed the nature of the neural processes underlying mental rotation and memory scanning and confirmed their different nature.

Cerebral Cortex↗