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Biomedical subjects

A Franco

Publications and source records attributed to A Franco.

At least 55 records · Page 3Linked to original sources

Postnatal development of female sheep pineal gland under natural inhibitory photoperiods: an immunocytochemical and physiological (melatonin concentration) study.

The purpose of this study was to determine structural and immunocytochemical changes taking place during the day and at night in developing sheep pineal gland under natural non-stimulatory photoperiods (summer solstice). Additionally, the diurnal cycle of plasma melatonin levels was charted and differences between diurnal and nocturnal pineal melatonin concentrations were analyzed. 36 ewes of three different ages were examined: infants (1-6 months old), pubertal and early fertile age (9-24 months old) and adults (36-60 months old). Plasma and pineal gland melatonin levels were higher in pubertal sheep than in infants or adults. Pubertal sheep pineal glands were also heavier, contained a larger number of pinealocytes and interstitial cells and displayed more evident innervation and vascularisation than infants or adults. There was no difference in the number of pinealocytes and interstitial cells between animals killed during daylight or at night. Gland weight, pinealocyte nuclear profile areas and plasma melatonin concentrations were all significantly higher at night than during the day.

Analysis of Variance↗

Improvement of the properties of granular sludge in UASB reactors by flow pulsation.

The objective of this work is to improve the characteristics of granular sludge by modification of the hydraulics of the bed through flow pulsation. Three UASB reactors, two operated with pulsing flow (P1 and P2) and a third without pulsation (NP), were started-up. Both recycling and feeding flow were pulsed in the reactor P1, while in reactor P2, only the feeding was pulsed. A high increase in the removal capacity and stability were achieved by applying pulsation in reactors P1 and P2 when compared to the non-pulsed one. Besides, pulsation promotes the formation of particles of smaller size and higher porosity, thus increasing the specific surface of the bed and consequently, the specific activity. In fact, while reactors P1 and P2 had a 95% COD removal when working at high organic loading rates (12 kg COD/m3 x d), reactor NP only reached 6 kg COD/m3 x d with 85% of removal capacity.

Biomass↗

SHP-1 expression in peripheral T cells from patients with Sezary syndrome and in the T cell line HUT-78: implications in JAK3-mediated signaling.

SHP-1 is a key tyrosine phosphatase that acts as a negative regulator of signal transduction in lymphocytes, which has been found down-regulated in several T cell lines derived from human T cell malignancies. The standardization of a sensitive ELISA for the quantification of SHP-1 protein in peripheral T and B lymphocytes has enabled us to quantify the SHP-1 content of freshly isolated T cells from patients with Sezary syndrome and in the Sezary T cell line HUT-78. In all cases, a dramatic decrease in the content of this protein, when compared with the content in healthy volunteer controls, was observed. These results were corroborated when the expression of SHP-1 mRNA was analyzed. In order to study whether there was any correlation between SHP-1 protein expression and tyrosine phosphorylated state of JAK3, the state of phosphorylation of JAK3 was studied in the T cell line HUT-78, and found to be highly phosphorylated. These results suggest that SHP-1 might be involved in maintaining the IL-2R/JAK3 signaling pathway under control and point towards a role of SHP-1 in the pathogenesis of the disease.

Enzyme Induction↗

Influence of pulsation on start-up of UASB reactors.

The aim of this work is to study the influence of pulsation on the start-up of lab-scale UASB reactors. Pulsation was produced by an Elastic Membrane Pulsator (EMP). The application of this device in previous works improved the performance of continuous fixed-bed fermentors and reduced the formation of preferential pathways, the retention of gas metabolites within the bed and the resistance to mass transfer. These characteristics seem to be suitable for feeding UASB reactors. In this work, the influence of pulsation frequency was studied in two pulsed UASB reactors operated in parallel with a non-pulsed one. One of them (P1) operated at high frequencies (periods of 50 and 200 s between each pulsation) and the other (P2) at low frequencies (periods of 3600 and 900 s between each pulsation). An important improvement of the removal efficiency for pulsed reactors with respect to the non-pulsed one was obtained. The structure of the biomass was observed at the end of the process by scanning electron microscopy. In general, granulation of biomass was improved when operating in pulsing form.

Bacteria, Anaerobic↗

[Changing profiles of proteinuria in renal transplantation. Predictive factors for its appearance].

Proteinuria is a risks factor that accelerates the progression of renal insufficiency by several mechanisms. In the renal transplant proteinuria is a predictor of progressive renal insufficiency and it is associated with poor patient and graft survival. We have performed a longitudinal observational case-control study to defect and quantify proteinuria in a group of 100 cadaveric renal transplant recipients and to evaluate the influence of several factors on its appearance. We have considered the variables age and sex of the donor and recipient, number of HLA-DR, A and B mismatches, cold ischemia time, basal renal disease, initial immunosuppression, immediate versus delayed graft function and acute rejection. Three patients who did with a functioning graft were excluded from the analysis of the data. All variables were analysed in a regression model of multivariate analysis. Proteinuria in the moths 1, 3, 6, 9 and 12 was: 0.38 +/- 0.27 g/day, 0.38 +/- 0.32 g/day, 0.44 +/- 0.99 g/day, 0.42 +/- 0.58 g/day and 0.37 +/- 0.54 g/day, respectively. We analysed the profile of the proteinuria in each patient individually. Fifty three patients (54.6%) did not develop proteinuria, 12 patients (12.4%) had transient initial proteinuria, 23 patients (23.7%) had persistent proteinuria and 9 patients (9.3%) had progressive proteinuria. The renal function differed between groups. Higher creatinine levels were found in the patients with persistent proteinuria and those with progressive proteinuria. We analysed the patients according to several variables. The age of the donor was higher in the group of patients with persistent proteinuria and the incidence of acute rejection was higher in the group of patients who developed progressive proteinuria, with differences statistically significant. There was no difference in the univariate analysis in the other variables considered. The multivariate analysis confirms that the age of the donor and the basal glomerular disease predict persistent proteinuria and acute rejection predicts progressive proteinuria. According to our study, proteinuria is frequent in the renal transplant recipient with different evolutionary profiles. Two types are associated with bad renal function and have different predictive factors. We encourage the use of drugs which reduce proteinuria.

Adult↗

[Diffuse lymphoproliferative disease after renal transplantation and its relation with Epstein-Barr virus. Experience at one center].

Post-transplant lymphoproliferative disorders (PTLD) are a group of heterogeneous lymphoid proliferations in chronic immunosuppressed recipients which appear to be related to Epstein Barr Virus (EBV). Receptor EBV seronegativity, use of antilymphocyte antibodies and CMV disease have been identified as risk factors that may tigger development of PTLD. We have studied the incidence of PTLD and its relationship with EBV in 588 adult renal transplant recipients who were transplanted in our hospital from 1988 to 2001. We have also evaluated the diagnostic and therapeutic methods used, the risk factors and outcome of the patients who developed PTLD. We identified 8 recipients (4 males and 4 females), range from 18 to 67 years (mean age 45.6 years) with a median time between grafting and PTLD of 4.1 years (0.1-7 years), who developed PTLD (1.3%). Only 1 patient received OKT3 and had CMV disease, two of them (25%) had been treated with hight doses of prednisolone, another was EBV seronegative, but the rest of them (50%) had no risk factors. Two patients were diagnosed at autopsy, the diagnosis of 5 was based on the histology of biopsy and the last one by CT scans of chest-abdomen and cytology. The presence of EBV in the lymphoproliferative cells was assessed in 5 out of the 7 studied patients (71.4%). The outcome of our recipients was poor. Five out of 8 patients died shortly after diagnosis as a direct consecuence of PTLD and another of an infectious complication of the treatment (75%). The 2 patients alive started dialysis and 1 of them died 2 years later of a non-related cause. In conclusion, PTLD is a relatively frequent disease with a poor prognosis in renal transplant patients. It seems to have a close relationship with EBV and can develop in the absence of the classical risk factors.

Adolescent↗

[Acceptability of computerized prescription writing in the hospital. Survey of 44 drug-prescribing physicians].

OBJECTIVES: The purpose of this work was to assess the acceptability of computerized prescriptions delivered by hospital prescribers. METHODS: The study was conducted in four clinical units of the Grenoble University Hospital that have a computerized prescription system. Forty-four physicians using the system responded to a questionnaire concerning the act of prescribing and the benefits or drawbacks of the system. RESULTS: Generally, the computerized prescription system was well accepted. The first drawback mentioned was the time spent manipulating the software. Safe prescription was noted as one of the advantages. Overall, organizational rather than technical factors appeared to condition the development of computerized prescription writing. CONCLUSION: Optimization of computerized prescription writing requires a reorganization of the care unit. Consultation schedules and working relations between the prescriber and other healthcares and hospital pharmacies will have to be adapted.

Attitude of Health Personnel↗

Tranexamic acid in off-pump coronary surgery: a preliminary, randomized, double-blind, placebo-controlled study.

BACKGROUND: We evaluated the hemostatic effects of tranexamic acid, a synthetic antifibrinolytic drug, in patients undergoing beating-heart coronary surgery. METHODS: Forty consecutive patients were in a double-blind manner, prospectively randomized into two groups: 20 patients received tranexamic acid (bolus of 1 g before skin incision, followed by continuous infusion of 400 mg/hr during surgery), and 20 patients received saline. As primary outcomes, bleeding and allogeneic transfusions were considered. D-dimer and fibrinogen plasma levels were also evaluated to monitor the activation of fibrinolysis. Major postoperative thrombotic events, as a potential consequence of antifibrinolytic treatment, were recorded. RESULTS: The treatment group had significantly lower postoperative bleeding (median [25th to 75th percentiles]: 400 mL [337 to 490 mL] vs 650 ml [550 to 862 mL], p < 0.0001), lower need for allogeneic blood products (1,200 vs 5,300 mL, p < 0.001), and lower postoperative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. CONCLUSIONS: In this initial series of patients undergoing off-pump coronary surgery, tranexamic acid appears to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Aged↗

[Thoracic empyema in very old patients: two types of clinical presentation].

INTRODUCTION: Primitive thoracic empyema or empyema secondary to pneumonia represents a significant medical problem necessitating prolonged hospitalizations and increasing the rates of morbidity and mortality. Average patient age is 55 years and remains rare in very old patients (> 85). We report here two observations in very old patients, pointing out the diversity of the clinical presentation. EXEGESIS: Empyema thoracis is classically associated with underlying diseases. It is often polymicrobial but Gram-positive bacteria and anaerobes are more frequent than Gram-negative bacteria. The clinical presentation may be aspecific without any parameters in favor of infectious disease: the rapidity of pleural drainage and antibiotic therapy are the main prognostic factors. CONCLUSION: Because of the diversity of clinical presentation in the elderly population, and because of the efficiency of rapid treatment, geriatric physicians should perform an examination of pleural fluid when pleural effusion is unknown.

Aged↗

Localization of Trichinella spiralis in muscles of commercial and parasitologic interest in pork.

Trichinellosis is widespread around the world with different representatives of the genus Trichinella found in almost every continent. In Argentina the main source of transmission for the disease to humans is pig meat infected with Trichinella spiralis. The object of this work was to determine the distribution of Trichinella larvae in fresh meat cuts which are sold for human consumption and in the muscles traditionally used for the disease diagnosis at meat-packing plants. Cranial muscles to the last rib showed more Trichinella spiralis larvae than those with a caudal location (p < 0.01). No significant differences were found (p > 0.05) between bilateral left and right muscles. Significant larval concentrations were found in the neck muscles, even in carcasses with a low parasitic load; these muscles are used to prepare cold meats (boston butt). Commercial cuts of meat had a substantial larval burdens in animals experimentally infected with 500 to 5,000 Trichinella spiralis larvae, with parasite burdens similar to infection levels in muscles evaluated at the meat packing plant.

Animals↗

Teleconsultation in psychology: the use of videolinks for interviewing and assessing elderly patients.

Although elderly people are one of the major target groups for telemedicine applications, they remain under-represented in studies of teleconsultation. Videolinks appear to be easily used by many elderly people as a means of communicating with health-care staff, including psychologists and doctors. To date, studies of psychometric teleconsultation have been confined to screening tests, or have used very small numbers of patients. There is a need to examine the reliability of more complex psychometric batteries and to use larger samples of older people. Some recommendations for conducting clinical interviews and psychometric tests are presented, based on clinical experience and a review of the literature. The importance of ergonomic considerations, patient comfort and professional preparation are explained.

Aged↗

Tranexamic acid administration after cardiac surgery: a prospective, randomized, double-blind, placebo-controlled study.

BACKGROUND: Many different doses and administration schemes have been proposed for the use of the antifibrinolytic drug tranexamic acid during cardiac surgery. This study evaluated the effects of the treatment using tranexamic acid during the intraoperative period only and compared the results with the effects of the treatment continued into the postoperative period. METHODS: Patients undergoing elective cardiac surgery with use of cardiopulmonary bypass (N = 510) were treated intraoperatively with tranexamic acid and then were randomized in a double-blind fashion to one of three postoperative treatment groups: group A: 169 patients, infusion of saline for 12 h; group B: 171 patients, infusion of tranexamic acid, 1 mg x kg(-1) x h(-1) for 12 h; group C: 170 patients, infusion of tranexamic acid, 2 mg x kg(-1) x h(-1) for 12 h. Bleeding was considered to be a primary outcome variable. Hematologic data, allogeneic transfusions, thrombotic complications, intubation time, and intensive care unit and hospital stay duration also were evaluated. RESULTS: No differences were found among groups regarding postoperative bleeding and outcomes; however, the group treated with 1 mg x kg(-1) x h(-1) tranexamic acid required more units of packed red blood cells because of a significantly lower basal value of hematocrit, as shown by multivariate analysis. CONCLUSIONS: Prolongation of treatment with tranexamic acid after cardiac surgery is not advantageous with respect to intraoperative administration alone in reducing bleeding and number of allogeneic transfusions. Although the prevalence of postoperative complications was similar among groups, there is an increased risk of procoagulant response because of antifibrinolytic treatment. Therefore, the use of tranexamic acid during the postoperative period should be limited to patients with excessive bleeding as a result of primary fibrinolysis.

Adult↗

Activation of coagulation and fibrinolysis during coronary surgery: on-pump versus off-pump techniques.

BACKGROUND: The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques. METHODS: Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, alpha(2) antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively. RESULTS: Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93-98%, P = 0.002, and 91.7% of baseline, 88-95%, P = 0.0001), respectively, whereas alpha(2)-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66-85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91-99%, P = 0.011), and increased D-dimer formation (476%, 309-741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups. CONCLUSIONS: Coronary surgery causes a net consumption of antithrombin and fibrinogen. A transient decrease in platelet counts, with plasminogen activation and increased D-dimer formation, however, is only observed with CABG. Twenty-four hours after surgery, the hemostatic profiles of patients in both groups are similar.

Blood Coagulation↗