Biomedical subjects
Publications and source records attributed to A Verdaguer.
We present an analytical model that explains how, in humid environments, the electric field near a sharp tip enhances the formation of water menisci and bridges between the tip and a sample. The predictions of the model are compared with experimental measurements of the critical distance where the field strength causes bridge formation.
Explore the source record for details and available documents.
In a population-based study, the consumption of resources for treating adult patients with community-acquired pneumonia was determined. During a 2-yr period, all cases with a clinical and radiological suspicion of community-acquired pneumonia that occurred in patients aged > 14 yrs in a community of 74,610 inhabitants were investigated prospectively. Of 292 cases with a suspicion of community-acquired pneumonia, 224 were included (18.5% misdiagnoses). The mean number of visits per patient was 4.5 (72% in the primary care setting). Inpatient care was recommended in 59.8% of cases; after discharge, 44% of patients were managed in outpatient clinics. The mean direct cost of pneumonia treated in the hospital setting was [symbol: see text] (euros) 1,553, whereas the mean cost of cases treated as outpatients was [symbol: see text] 196. A total of 15.7% of admissions were considered inappropriate and the length of stay could have been reduced by 3.5 days in the most severe cases. A reduction in inappropriate admissions and lengths of hospital stay would result in a decrease in cost of 17.4%. Community-acquired pneumonia in Maresme, Spain, occurs at a low incidence, although with a high percentage of hospitalisations (in part inappropriate), resulting in considerable costs.
PURPOSE: Infants with acute leukemia have a poor prognosis when treated with conventional chemotherapy. It is still unknown if stem-cell transplantation (SCT) can improve the outcome of these patients. In the present study, we review our experience with SCT in infant acute leukemia to clarify this issue. PATIENTS AND METHODS: We report the results of 26 infants who were submitted to a SCT for acute leukemia. There were 15 cases of acute myeloid leukemia and 10 cases of acute lymphoid leukemia. One patient had a bilineal leukemia. Twenty-two patients were in their first complete response (CR1), three were in their second CR, and one was in relapse. Eight patients were submitted to allogeneic SCT, and 18 underwent autologous SCT. RESULTS: With a median follow-up of 67 months, the 5-year overall survival and disease-free survival (DFS) are 64% (SE = 9%) and 63% (SE = 10%), respectively. Autologous and allogeneic SCT offered similar outcome. There was not any transplant-related mortality, and all deaths were caused by relapse in the first 6 months after SCT. In multivariate analysis, the single factor associated with better DFS was an interval between CR1 and SCT of less than 4 months (P: <.025). CONCLUSION: SCT is a valid option in the treatment of infant acute leukemia, and it may overcome the high risk of relapse with conventional chemotherapy showing very reduced toxicity. This study suggests that SCT should be performed in CR1 in the early phase of the disease.
Time correlation functions between the velocity of a tagged particle and velocities of particles within specified ranges of initial separations have been obtained by molecular dynamics simulation. These correlation functions have allowed us to analyze the momentum transfer between particles in different coordination shells. Two simple liquids at very different densities and two purely repulsive potentials with very different softnesses have been considered. The longitudinal correlations, which are the velocity cross-correlations along the initial direction defined by the centers of two given particles, have been calculated separately. It has been proven that these correlations should be attributed to particles both in front of and behind the central one. As with propagating longitudinal modes, they are strongly dependent on the softness of the potential core. Some characteristic features of the velocity correlation functions after the initial rise should be related to nonlongitudinal correlations. It has been shown that velocity cross-correlations between distinct particles cannot only be attributed to the direct interactions among particles, but also to the motions induced by the movement of a tagged particle on their neighbors.
We report a retrospective analysis on 46 pediatric patients (median age 9 years, range 1-17 years) with non-Hodgkin's lymphoma (NHL), transplanted in six Spanish centers. Fourteen patients underwent allogeneic bone marrow transplantation (BMT) and 32 autologous BMT. Most patients were boys (36 of 46). Twenty one cases were of lymphoblastic lymphoma, 19 Burkitt's lymphoma and six diffuse large cell lymphoma. Maximal Murphy's stage any time before BMT was stage III in 17 cases and stage IV in 29 cases. At BMT, 13 cases were in first CR, 21 in second CR, seven in third CR, four with sensitive active disease and one with refractory disease. All patients transplanted in CRl were considered candidates for BMT because of delayed CR (two cases), failure of the first-line therapy (seven cases) or central nervous system (CNS) or BM infiltration at diagnosis (four cases). Conditioning therapy included TBI in 33 patients and 13 cases were conditioned with chemotherapy alone. Toxic mortality was 13% (three of 14 in the allogeneic BMT group and three of 32 in the autologous group). No toxic deaths were registered in 13 patients undergoing BMT in CR1 (three allogeneic BMT and ten autologous BMT). Twelve patients relapsed 1-7 months after BMT. Overall event-free survival (EFS) was 58% (42-73%; confidence interval (CI) 95%), with a median follow-up of 33 months. EFS was similar for allogeneic BMT and autologous patients. Disease status at BMT was the only predictive factor for EFS (P < 0.01). There were no significant differences between patients in CR1 (82.5%) and CR2 (68%).(ABSTRACT TRUNCATED AT 250 WORDS)
This one year prospective multicentre study was designed to determine the incidence of community-acquired pneumonia in adults. It was carried out in primary health care centres and three reference hospitals, located in the 'Maresme' region (Barcelona, Spain) serving a population of 39,733 subjects over 13 years of age. Patients suspected of having contracted community-acquired pneumonia were visited by their family doctors and referred to the three reference hospitals for confirmation of the diagnosis. Patients attending the emergency services of these hospitals were also included. Urine and blood samples were obtained for culture, antigen detection, blood count, serological tests, blood gases and biochemical profile. The diagnosis of community-acquired pneumonia was made in 105 patients. Forty-six patients had an identifiable microbial etiology. Chlamydia pneumoniae was the most common pathogen (16 cases) followed by Streptococcus pneumoniae (13 cases) and Mycoplasma pneumoniae (8 cases). In conclusion; the annual incidence rate of community-acquired pneumonia in adults in this area was 2.6 cases per 1,000 inhabitants and Chlamydia pneumoniae was the most frequent causative pathogen.
The present study validates the expert system PNEUMON-IA. The aim of PNEUMON-IA is assessing the etiology of community-acquired pneumonias from clinical, radiological, and laboratory data obtained at the onset of the disease. Validation was performed using data from medical records of 76 patients with proven clinical diagnosis of pneumonia. The etiological diagnoses provided by PNEUMON-IA were compared to those established by five specialists unrelated to the development of the expert system. For each etiological possibility, both PNEUMON-IA and the experts provided a causal possibility, expressed as a linguistic label (i.e., "almost impossible"). Linguistic labels were then converted to numeric values. In the majority of cases, an etiological diagnosis was unavailable to be used as a gold standard. To overcome this limitation, distances between arrays of etiological possibilities given by specialists and by PNEUMON-IA were considered as an agreement measure between diagnoses. Cluster analysis based on those distances was used to classify PNEUMON-IA among experts. Results showed the same differences between specialists and PNEUMON-IA as among the specialists themselves. The method used to validate PNEUMON-IA could prove useful to assess the performance of expert systems in fields where no gold standard is available.
Ninety nine patients suffering of acute pyelonephritis are prospectively analyzed. Mean age was 39.8 +/- 18.2 (mean +/- DE), 72 of them were females and 19 were males. The most frequent clinical manifestations were fever and side pain in 97% of the cases and lower urinary syndrome in 78%. The duration of symptoms previous to the visit was 3.5 +/- 2.9 days. Bacteremia was confirmed in 99% of cases, it affected the oldest patients (p less than 0.001) and provoked the lasting of fever (p less than 0.05). E. coli was the most frequently isolated microorganism with an incidence of 91% in the isolated samples. Gentamicin was the initial treatment and the definitive treatment was prolonged to a total of 14 days. Fifteen percent of patients were classified after the evaluation as carriers of complicated pyelonephritis and had to undergo afterwards a urologic treatment. Follow up over a minimum of 6 weeks showed a treatment failure in 2% of cases and recurrency in 22%.
The effectiveness of a clinical and a microbiological follow-up systems for the detection of hospital-acquired infection (HI), both independently and simultaneously applied, were prospectively evaluated. The observed incidence rate was 11.4%. The clinical follow-up detected 81.3% of HI while microbiological follow-up detected 59.7%. This difference was statistically significant (p less than 0.001). It took 43 and 45 minutes to detect each instance of HI with the clinical and microbiological methods, respectively. Clinical methods are the most adequate to obtain maximal sensitivity in the overall surveillance of hospital-acquired infection, whereas microbiological follow-up may be useful for the detection of some types of HI such as bacteremia or urinary tract infection.
This is the report of a case of breakage and detachment in the pleural cavity of the tip of a nearly new Abrams needle during performance of a pleural biopsy. We have not found any reference in the literature to similar accidents and do not know what later complications may be produced by the metal body in the pleural cavity. In this case, there have been no complications 12 months after the incident.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A prospective four-year study on the infection rate of clean operative wounds is presented. From January 1982 to June 1985, a nurse epidemiologist and a medical team assessed 4,468 operative procedures, from the day of surgery to the patients' discharge from the hospital. The infection rate was 3.2%. A higher incidence of wound infection was detected in patients requiring emergency operations (5.1%), in drained wounds (5.4%), and in patients with conditions thought to predispose to infection, such as advanced cancer, hepatic cirrhosis, diabetes, nephrotic syndrome, previous splenectomy, and treatment with immunosuppressive drugs (7.8%). Age over 65 did not influence infection rates. There were up to tenfold differences in infection indices between surgeons performing the same clean procedures. The continued monitoring of clean wound infection rates allowed the early detection and control of infection outbreaks. Providing periodic information on infection rates to the different surgical services was associated with decreasing infection rates over time.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.