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C Klersy

Publications and source records attributed to C Klersy.

At least 37 records · Page 2Linked to original sources
PubMed2002

Mid term effects of pulmonary thromboendarterectomy on clinical and cardiopulmonary function status.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) can be successfully treated surgically by pulmonary thromboendarterectomy (PTE) but there are few data on mid-term cardiopulmonary function, particularly on exertion, and clinical benefits following pulmonary PTE. METHODS: A 2 year follow up study was undertaken of clinical status, haemodynamic and lung function indices, gas exchange, and exercise tolerance in 38 patients of mean (SD) age 50 (15) years who had undergone PTE. RESULTS: In-hospital mortality was about 10%. Before PTE all the patients were severely impaired (NYHA classes III-IV). There was no time difference in the improvement in the parameters: nearly all the improvement in cardiac output, gas exchange, and clinical status was achieved in the first 3 months as a result of the relief of pulmonary obstruction. At 3 months the percentage of patients with normal cardiac output and PaO(2) and of those with reduced clinical impairment increased to 97%, 59%, and 87%, respectively, without any further change. Only mean pulmonary artery pressure (mPAP), carbon monoxide transfer factor (TLCO), and exercise tolerance improved gradually during the second year, probably due to the recovery of the damaged small vessels. TLCO was overestimated before PTE but afterwards the trend was similar to that of mPAP. CONCLUSIONS: At mid term only a few patients did not have a satisfactory recovery because of lack of operative success, hypertension relapse, or the effect of preoperative hypertension on vessels in non-obstructed segments. Most of the patients, even the more compromised ones, had excellent long lasting results.

Blood Pressure↗
PubMed2002

Influence of underlying lung disease on early postoperative course after single lung transplantation.

BACKGROUND: Single lung transplantation can be a suitable therapeutic option for a wide range of end-stage lung diseases: pulmonary fibrosis, emphysema, primary pulmonary hypertension and Eisenmenger's syndrome. Yet, patients suffering from different diseases have significantly different cardiovascular and respiratory functional profiles that can exert a profound influence on their response to the perioperative procedures. Our purpose is to analyze whether the patient's underlying disease can influence the early postoperative outcome after single lung transplantation. METHODS: We carried out a retrospective analysis on perioperative charts of patients undergoing single lung transplantation during an 8-year period. We focused our attention on the following data: underlying lung disease, age, sex, baseline cardiorespiratory data (pulmonary artery pressure, cardiac index, forced expired volume, vital capacity, arterial blood gases, body mass index), intraoperative data (duration of graft ischemia, use of cardiopulmonary bypass) and indexes of adverse postoperative outcome (in-hospital death, mechanical ventilatory support >7 days). Patients were gathered in 3 groups (restrictive, obstructive and vascular) according to the kind of disease and functional data and the association between disease and outcome was assessed by means of logistic regression analysis. Moreover, we evaluated whether any of the patient's functional parameters could be considered predictive of adverse postoperative outcome. RESULTS: We observed a weak association between restrictive disease and adverse postoperative outcome while, on the other hand, obstructive and vascular forms showed a close association with an adverse outcome, with a borderline statistical significance. Among all the considered variables, only intraoperative use of CPB turned out to be predictive of adverse outcome, while other variables simply indicated a trend towards a better outcome. CONCLUSIONS: Patients with vascular and obstructive diseases have the worst postoperative course, with a higher in-hospital mortality rate and longer duration of ventilation; in particular, the perioperative course of vascular patients is heavily influenced by the intraoperative use of cardiopulmonary bypass.

Adult↗
PubMed2002

[Deep lamellar keratoplasty].

INTRODUCTION: Deep lamellar keratoplasty (DLKP) is a surgical technique in which the entire corneal stroma is removed down to the Descemet membrane. METHODS: The difference between deep lamellar keratoplasty and classic lamellar keratoplasty is qualitative rather than quantitative. In the first technique, the anatomical cleavage plane provides clear separation of the stroma and the Descemet membrane. This plane has a clear and smooth surface. On the contrary, classic lamellar dissection down to 2/3 of the stroma results in a very rough and uneven surface with a risk of low visual acuity. PURPOSE: To compare the results of 200 cases treated with deep lamellar keratoplasty and 200 cases of penetrating keratoplasty (PK). RESULTS: No rejection episodes were recorded in the 200 patients who underwent DLKP surgery, whereas rejection occurred in 4% of the patients after PK. The number of endothelial cells, measured with a Konan instrument 1 month after removal of the sutures in patients who underwent deep lamellar keratoplasty, was double that in patients who underwent penetrating keratoplasty. CONCLUSION: The number of endothelial cells does not change after DLKP, but is substantially reduced after PK. The degree of astigmatism is greatly reduced and functional recovery is faster with the first technique. These are the main reasons why we think that DLKP could replace PK as the best procedure in all cases in which no endothelial damage is involved.

Cornea↗
PubMed2001

Long-term (> or =8 years) outcome after Palmaz-Schatz stent implantation.

The purpose of this single-center study was to evaluate the long-term (> or =8 years) outcome of Palmaz-Schatz intracoronary stenting and to identify independent predictors of outcome. Although short-term results of Palmaz-Schatz intracoronary stenting have been promising, with a reduction in both angiographic restenosis and clinical cardiac events up to 3 years, longer-term follow-up has not been established. We analyzed clinical outcome in 426 consecutive patients at least 8 years after coronary stenting. Demographic, clinical, and procedural predictors of restenosis, survival, and event-free survival, defined as freedom from death, myocardial infarction (MI), and coronary revascularization (target stented site, target vessel, and any revascularization) were analyzed. Before discharge, 28 patients (6.6%) sustained at least 1 major cardiovascular event: 3 deaths (0.7%), 18 MIs (4.2%), and 17 repeat revascularizations. Surviving patients were followed for 8.9 years (interquartile range 8.4 to 9.4). After discharge, 59 patients (13.9%) died, 47 (11.1%) sustained an MI, and 188 (44.4%) underwent coronary revascularization. The 8-year event-free survival (freedom from death, freedom from death/MI/target-stented site revascularization, and freedom from death/MI/any coronary revascularization) was (mean +/- SE) 0.86 +/- 0.01, 0.62 +/- 0.03, and 0.47 +/- 0.02, respectively. Unstable angina, lower left ventricular ejection fraction, and saphenous vein graft stenting were found to be independent predictors of death during follow-up. Hypertension, unstable angina, multivessel disease, and multiple stent implantation were found to be independent predictors of the composite of death/MI/any coronary revascularization during follow-up. This study provided a useful assessment of very long-term outcome in survival, event-free survival, and predictors of major cardiac events 8 to 10 years after Palmaz-Schatz stent implantation.

Coronary Angiography↗
PubMed2001

Complete or incomplete percutaneous coronary revascularization in patients with unstable angina in stent era: Are early and one-year results different?

The aim of our study was to evaluate the impact of a strategy of incomplete revascularization by PTCA, with or without stent implantation, on clinical outcome of 208 consecutive patients (171 men) with unstable angina and multivessel coronary artery disease. Mean age of the group was 63.8 +/- 10.3 years (range, 31-91). Complete and incomplete revascularization was achieved in 49 and 159 patients, respectively. A total of 226 stents were implanted in 172 patients (1.31 +/- 0.65 stent per patient), equally distributed between the two groups. Left ventricular ejection fraction < 40% and total chronic coronary occlusions were significantly more frequent in patients with incomplete revascularization than in those with complete (P = 0.014 and 0.001, respectively). In-hospital MACE occurred in 10% and 7.5% of patients with complete and incomplete revascularization, respectively (P = NS). By multivariate analysis, multiple stent implantation (OR, 5.44; 95% CI, 1.21-24.3), presence of thrombus in the treated lesion (OR, 6.3; 95% CI, 1.53-25.9), Braunwald class III (OR, 4.74; 95% CI, 1.08-20.8), and ad hoc PTCA (OR 4.51; 95% CI, 1.11-18.3) were significantly related to in-hospital outcome. At 1-year follow-up, 11.3% and 11.5% of patients with complete and incomplete revascularization, respectively, had MACE. In all patients, diabetes (OR, 3.40; 95% CI, 1.09-10.58) and presence of thrombus in the treated lesion (OR, 3.48; 95% CI, 1.12-10.84) were significant predictors of 1-year outcome by multivariate analysis. These results indicate that the strategy of incomplete revascularization in unstable angina patients with multivessel coronary disease does not expose them to a higher risk of death or other major ischemic events in comparison to those undergoing complete revascularization.

Adult↗
PubMed2001

Echocardiographic evaluation of patients cured of childhood cancer: a single center study of 117 subjects who received anthracyclines.

BACKGROUND: The risk of cardiomyopathy following exposure to anthracycline in asymptomatic long-term survivors of childhood cancer is still hard to predict and precisely quantify. To identify the impact of different cumulative doses, even within a non-high dose range, and the echocardiographic parameters suitable for evaluating cardiac function, we studied diastolic and systolic echocardiographic parameters in a cohort of patients followed in a single center. PROCEDURE: A total of 117 subjects were studied at a median time of 7 years after treatment completion. A complete M-mode, two-dimensional and Doppler echocardiographic study was obtained at rest in all patients according to the standard recommendations of the American Society of Echocardiography. RESULTS: Ninety-nine patients (85%) had completely normal cardiac function, while 18 had abnormal echocardiographic findings: 12 had one abnormal value, 5 had two, and 1 had three abnormal values. All the changes were in left ventricular dimensions, wall thickness or indices of systolic function; no alterations in left ventricular diastolic function parameters were found. None of the echocardiographic parameters correlated significantly with the cumulative dose of anthracyclines administered either at univariate analysis or after adjusting for sex, body surface area or considered risk factors. CONCLUSIONS: Subjects exposed to a median cumulative dose of 214 mg/m(2) had no echographic abnormalities a median of 7 years later. We did not find any correlation between cumulative anthracycline dose and the echocardiographic parameters tested. We now offer echocardiographic follow-up to patients with mildly reduced fractional shortening and/or ejection fraction to rule out late onset dysfunction.

Antibiotics, Antineoplastic↗
PubMed2001

The role of histological investigation in prognostic evaluation of advanced gastric cancer. Analysis of histological structure and molecular changes compared with invasive pattern and stage.

The relative contribution of tumour histology or molecular changes, compared with invasion pattern or stage, to prognostic assessment of gastric cancer was investigated in a series of 185 advanced (T2 to T4, stage IB to IV) cancers that had undergone intentionally curative surgery at Varese General Hospital. Survival analysis of the histological types considered in commonly used classifications, such as Lauren, Kubo, the World Health Organization (WHO) and related classifications, allowed separation of a small high-grade (Hg, 12 cases) group of adenosquamous, anaplastic and small cell endocrine carcinomas from a large cohesive group (C, 86 glandular or solid cancers) and from another large (87 cases) group of tumours with dissociated cells [29 diffuse (D) and 58 mixed (M) tumours]. Univariate and multivariate analysis showed the independent prognostic value of this C/M+D/Hg classification approach, which proved superior to other classifications and to cell dissociation at the growing front or angio, lympho and neuro-invasion. Expression of sialyl Lewis(c), the DUPAN-2 antigen, proved to be an independent predictor of worse survival among tumours beyond stage I, showing an exclusively or predominantly cohesive structure. Microsatellite instability (MSI) predicted favourable survival in purely cohesive tumours of intermediate (II) stage, especially of solid/medullary and lymphoid stroma/lympho-epithelioma-like structure, among which two distinct tumour subsets were characterised, one MSI-positive and the other Epstein-Barr virus positive. T2NOM0 (stage IB) tumours showed mostly favourable survival independently from histological type, invasive pattern, DUPAN-2 or MSI status. It is concluded that an appropriate histological evaluation, coupled with sialylated glycoproteins histochemistry and, for stage-II tumours, MSI tests may contribute significantly to prognostic assessment of tumours beyond stage I. However, the stage itself, with special reference to lymph-node metastases and invasion level beyond subserosa, remains the most important prognostic clue for gastric cancer.

Adenocarcinoma↗
PubMed2001

Independent and additive prognostic value of right ventricular systolic function and pulmonary artery pressure in patients with chronic heart failure.

OBJECTIVES: We sought a better understanding of the coupling between right ventricular ejection fraction (RVEF) and pulmonary artery pressure (PAP), as it might improve the accuracy of the prognostic stratification of patients with heart failure. BACKGROUND: Despite the long-standing view that systolic function of the right ventricle (RV) is almost exclusively dependent on the afterload that this cardiac chamber must confront, recent studies claim that RV function is an independent prognostic factor in patients with chronic heart failure. METHODS: Right heart catheterization was performed in 377 consecutive patients with heart failure. RESULTS: During a median follow-up period of 17 +/- 9 months, 105 patients died and 35 underwent urgent heart transplantation. Pulmonary artery pressure and thermodilution-derived RVEF were inversely related (r = 0.66, p < 0.001). However, on Cox multivariate survival analysis, no interaction between such variables was found, and both turned out to be independent prognostic predictors (p < 0.001). It was found that RVEF was preserved in some patients with pulmonary hypertension, and that the prognosis of these patients was similar to that of the patients with normal PAP. In contrast, when PAP was normal, reduced RV function did not carry an additional risk. CONCLUSIONS: These observations emphasize the necessity of combining the right heart hemodynamic variables with a functional evaluation of the RV when trying to define the individual risk of patients with heart failure.

Adult↗
PubMed2001

Does ethnicity predict lactation? A study of four ethnic communities.

Human lactation is influenced by a variety of interrelated factors. The purpose of the study was to see whether the racial/ethnic factor is predictive of the onset of lactation and of the volume of breast milk. We planned a prospective study enrolling 269 women who were classified into four ethnic groups: Group 1 Arabs, Group 2 Africans, Group 3 Eastern Europeans, Group 4 Italians. Data regarding the women's habits, medical history and pregnancy were collected. After delivery we recorded the onset of lactogenesis and volume of milk output up until the fifth post-delivery day. A Cox model was fitted in order to assess the independent role that ethnicity has on the time to lactation; a general linear model was used to relate ethnicity to the overall amount of milk produced. Mean age was 27 years and was similar in all groups; half of the women were primiparae. All babies were exclusively breast-fed. Median time to lactation was 36 hours (20-36) and the median daily amount of milk produced was 173.5 ml (119-215). The earliest onset of lactation and the highest milk output was registered among Arab and Eastern European women. On Cox regression analysis ethnicity appeared to be an independent predictor of earlier lactogenesis: breast milk output occurred significantly earlier in the immigrant population than it did in the Italian population. No difference was observed among the immigrants. The multiple regression model showed that ethnicity independently predicts the overall amount of milk production: the Immigrant population produced a significantly higher milk output than the Italian population. No differences were observed within the immigrant groups. Ethnicity has been shown to be associated with the characteristics of breast-feeding. Further research is needed to understand the underlying mechanism.

Adult↗
PubMed2001

Factors influencing post-transfusional platelet increment in pediatric patients given hematopoietic stem cell transplantation.

Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) always require platelet transfusions, but the increase in platelet count is often less than expected. Since factors responsible for poor response to platelet transfusions in this clinical setting are largely unknown, we performed a prospective study in 87 consecutive children transplanted in a single institution. The mean 16-h corrected count increment (CCI) of 598 platelet transfusions was 5.76 +/- 8.32 x 10(9)/l. Both before and after HSCT, 13.8% of patients had antibodies against HLA and/or platelet-specific antigens. Univariate analysis identified 12 factors significantly associated with a lower post-transfusion CCI, but only four reached statistical significance in the multivariate analysis. These four factors were concomitant therapy with vancomycin, alloimmunization, use of an Autopheresis cell separator for preparation of platelet concentrates and cytomegalovirus infection. We, therefore, suggest that a better response to platelet transfusions could be obtained by choosing a suitable cell separator, by avoiding the use of vancomycin and by adopting measures that reduce alloimmunization and CMV infection. Moreover, screening patients for HLA and platelet-specific antibodies before HSCT would identify the majority of subjects who will develop alloimmune refractoriness after transplantation and would allow the search for a compatible donor in advance.

Analysis of Variance↗
PubMed2001

Donor-recipient incompatibility at CD31-codon 563 is a major risk factor for acute graft-versus-host disease after allogeneic bone marrow transplantation from a human leucocyte antigen-matched donor.

Disparities at minor histocompatibility antigens (mHA) are thought to be responsible for acute graft-versus-host disease (aGVHD) in patients receiving bone marrow transplantation (BMT) from a human leucocyte antigen (HLA)-matched donor. Although some mHA have been identified in humans, their role in aGVHD has not. Patients (n = 150) receiving a BMT from an HLA-matched donor were investigated for a correlation between aGVHD and donor/recipient incompatibility for seven polymorphisms previously proposed for mHA (HA-1, H-Y, CD31-codon 125, CD31-codon 563, HPA-1, HPA-3 and HPA-5). Only mismatch at CD31-codon 563 predicted grade II-IV aGVHD. The risk derived from CD31-codon 563 mismatch was the same as that derived from the use of bone marrow from an unrelated donor. We suggest that donor/recipient compatibility at CD31-codon 563 should be added to HLA-typing for donor selection and/or adjustment of aGVHD prophylaxis.

Acute Disease↗
PubMed2001

Doppler velocimetry in superior vena cava provides useful information on the right circulatory function in patients with congestive heart failure.

BACKGROUND: Although flow velocities curves recorded with pulsed-wave Doppler in systemic vein are known to provide functional data on the right circulatory function, little information is available on the relationship between right heart filling dynamics and right ventricular function. METHODS: Consecutive patients with chronic heart failure due to severe systolic left ventricular dysfunction and in sinus rhythm underwent echocardiography and right heart catheterization. In the initial part of the study, the hemodynamic correlates of different flow velocity patterns recorded into the superior vena cava were evaluated in 120 patients. The accuracy of the prediction of different right heart hemodynamic profiles by means of the different venous flow patterns was then prospectively tested in a subsequent series of 86 patients. RESULTS: The venous flow pattern was closely related to right heart hemodynamics. A normal Doppler pattern identified patients with normal right heart hemodynamics (sensitivity 86%, specificity 78%); a "predominant systolic wave" pattern identified patients with a reduced thermodilution-derived right ventricular ejection fraction (< 30%) and normal or slightly elevated right atrial pressure (< or = 8 mmHg) (sensitivity 69%, specificity 81%); a "predominant diastolic wave" pattern identified patients with a reduced right ventricular ejection fraction (< 3 0%) and elevated right atrial pressure (> 8 mmHg) (sensitivity 52%, specificity 95%). The observed and the predicted hemodynamic profiles turned out to be concordant in 80% of patients. CONCLUSIONS: The analysis of the flow velocity pattern into the superior vena cava is a useful tool to estimate the extent of the right circulatory impairment in patients with congestive heart failure.

Adult↗
PubMed2001

Dilated intercellular spaces as markers of reflux disease: histology, semiquantitative score and morphometry upon light microscopy.

BACKGROUND AND AIMS: A recent electron microscopy study suggested that dilated intercellular spaces (DIS) are specific for acid reflux-damaged esophageal epithelium. Electron microscopy is, however, expensive and difficult to apply to routine biopsies. The aims of this study are to establish a method for assessing DIS on light microscopy of esophageal biopsies and to estimate its association with current clinicopathological parameters of esophagitis. MATERIALS AND METHODS: 21 patients with reflux symptoms were investigated. Light microscopy biopsies were assessed for DIS size by a semiquantitative method and computer-assisted, static morphometry. A DIS score accounting for DIS size and distribution was assigned to each patient and its association with 30 clinicopathological variables investigated by univariate and multivariate logistic regression. RESULTS: Both the semiquantitative method and static morphometry identified 4 different classes of DIS size. The DIS score was significantly and independently associated with the esophageal symptoms score, the histological score of esophagitis and the relevant morphometry data. CONCLUSIONS: DIS may be efficiently assessed during light microscopy of routine esophageal biopsies. Since correlation with both the histology and the symptoms of esophagitis, the DIS score may be considered a novel parameter of esophagitis and is suggested for the routine evaluation of esophageal biopsies in patients with reflux disease.

Adult↗
PubMed2001

Risk of type 1 diabetes development in children with incidental hyperglycemia: A multicenter Italian study.

OBJECTIVE: The aim of our study was to determine whether children with incidental hyperglycemia are at an increased risk of developing type 1 diabetes. RESEARCH DESIGN AND METHODS: A total of 748 subjects, 1-18 years of age (9.04 +/- 3.62, mean +/- SD), without family history of type 1 diabetes, without obesity, and not receiving drugs were studied and found to have incidental elevated glycemia defined as fasting plasma glucose >5.6 mmol/l confirmed on two occasions. Subjects were tested for immunological, metabolic, and immunogenetic markers. RESULTS: Islet cell antibodies >5 Juvenile Diabetes Foundation units were found in 10% of subjects, elevated insulin autoantibody levels in 4.6%, GAD antibody in 4.9%, and anti-tyrosine phosphatase-like protein autoantibodies in 3.9%. First-phase insulin response (FPIR) was <1st centile in 25.6% of subjects. The HLA-DR3/DR3 and HLA-DR4/other alleles were more frequent in hyperglycemic children than in normal control subjects (P = 0.012 and P = 0.005, respectively), and the HLA-DR other/other allele was less frequent than in normal control subjects (P = 0.000027). After a median follow-up of 42 months (range 1 month to 7 years), 16 (2.1%) subjects (11 males and 5 females), 4.1-13.9 years of age, became insulin dependent. All had one or more islet autoantibodies, and the majority had impaired insulin response and genetic susceptibility to type 1 diabetes. Diabetes symptoms were recorded in 11 patients and ketonuria only in 4 patients. The cumulative risk of type 1 diabetes was similar in males and females, and it was also similar in subjects under or over 10 years, whereas the cumulative risk of type 1 diabetes was increased in subjects with one or more autoantibodies and in those with FPIR <1st centile. CONCLUSIONS: Children with incidental hyperglycemia have a higher-than-normal frequency of immunological, metabolic, or genetic markers for type 1 diabetes and have an increased risk of developing type 1 diabetes.

Adolescent↗
PubMed2001

Biochemical markers of bone disease in asymptomatic early stage multiple myeloma. A study on their role in identifying high risk patients.

BACKGROUND AND OBJECTIVES: Skeletal involvement is typical of multiple myeloma (MM) and its occurrence increases with the progression of the disease. We performed a study to evaluate the clinical importance of osteocalcin (bone gla-protein, BGP) and bone alkaline phosphatase (b-AP) as indices of osteoblastic activity, and deoxypyridoline (DPD) as a marker of bone resorption. DESIGN AND METHODS: Fifty-two MM patients, 39 patients with monoclonal gammopathy of undetermined significance (MGUS), and 30 normal controls entered the study. Of the 52 MM patients, 10 showed lytic lesions at standard X-rays and 42 did not; 21 were untreated and 31 had been treated with chemotherapy (combined with bisphophonates in 15). Of these last, 12 had progressive disease and 19 were in plateau phase. RESULTS: DPD levels were higher in MM patients than in patients with MGUS or healthy controls (p = 0.0001 and p = 0.0008, respectively). No statistical differences were seen between patients with MGUS and healthy controls. BGP serum levels were significantly lower in MM patients than in MGUS patients (p = 0.001) or healthy controls (p = 0.001). b-AP was significantly higher in MGUS patients than in MM patients (p = 0.04). Biochemical parameters were analyzed in a continuous fashion and after dichotomization into low and high values with respect to normal ones. Abnormal high values of DPD showed statistically significant correlations with presence of osteolysis (p = 0.008), advanced stage (p = 0.03) and abnormal beta2-microglobulin (beta2M) values (p = 0.03), while DPD as a continuous variable correlated significantly only with the presence of osteolysis (p = 0.02). In contrast, neither BGP nor b-AP showed statistical correlations with the presence of lytic lesions, or with other clinical or laboratory parameters. In 15 patients followed with serial controls, modifications of DPD levels reflected bone disease status well. Of the 42 patients without radiologic evidence of skeletal lesions, 15 had abnormal DPD values. Spinal magnetic resonance imaging (MRI) showed initial lytic lesions in 10 of them. INTERPRETATION AND CONCLUSIONS: Biochemical markers of bone metabolism are useful in evaluating and monitoring skeletal involvement in MM patients. They may help clinicians to identify: 1) from among patients without radiologic evidence of lytic lesions, those who deserve more accurate radiologic examinations (namely MRI); 2) from among asymptomatic patients, and in association with spinal MRI, those patients at higher risk of progression who might benefit from early treatment.

Adult↗
PubMed2001

Impact factor and electronic versions of biomedical scientific journals.

BACKGROUND AND OBJECTIVES: The development of electronic editions of scientific journals and the rapid spread of scientific information might modify the pattern the bibliographic citations, and thus the impact factor and quality of journals. We assessed changes in the impact factor over years of a number of journals and whether the presence of an electronic version of the journal was associated with the impact factor score. DESIGN AND METHODS: This is a retrospective longitudinal study. The availability of journals (table of contents (TOC), abstracts, full text and free full text) on Internet, in years 1995-2000, was assessed between December 2000 and January 2001. The first 20 top-journals from 8 subject categories were included. Changes in impact factor over time and association with Internet availability were modeled. RESULTS: Overall, 118/139 journals (85%) had their TOC on the Internet, of these 107 (77%) had abstracts, 97 (70%) had full text and 33 (24%) free full text. The median impact factor for all journals was 1.65, 2.08, 2.10, 2.21 and 2.35 for the years from 1995 to 1999, respectively. This increase was statistically significant, with differences among subject categories. The presence of TOC, abstracts and full text on the Internet was also significantly associated with higher impact factor, after accounting for time and subject category. INTERPRETATION AND CONCLUSIONS: The impact factor has been used for assessing the quality of journals. We identified a new limitation of this indicator: the impact factor seems to be related to the amount of circulation of information through Internet. This could be a temporary limitation, associated with diffusion of journals on, and spread of Internet.

Bibliometrics↗