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Biomedical subjects

C Beguin

Publications and source records attributed to C Beguin.

30 records · Page 2Linked to original sources

Early signs and risk factors for the increased incidence of Epstein-Barr virus-related posttransplant lymphoproliferative diseases in pediatric liver transplant recipients treated with tacrolimus.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a life-threatening condition the incidence of which in pediatric solid organ transplantation may be related to the immunosuppressive load. It has been suggested that tacrolimus, a new and potent immunosuppressor, causes an increased incidence of this syndrome. METHODS: The incidence, early signs, and risk factors for lymphoproliferative disease were reviewed in a cohort of 89 pediatric liver transplant recipients treated with tacrolimus. RESULTS: Eighteen patients (20%) developed a PTLD-16 concomitant to a primary Epstein-Barr virus (EBV) infection and 2 with previous immunity against EBV. Three additional patients had preliminary signs of PTLD concomitant to primary EBV infection, but did not develop individualized lymphoid masses. Six patients died (6.7% of all tacrolimus-treated patients). Mean tacrolimus blood level during the 3 months preceding EBV infection reached 11.8+/-1.8 ng/ml in PTLD patients versus 9.4+/-3.4 ng/ml in non-PTLD patients (0.05<P<0.1). Previous OKT3 or antithymocyte globulin treatment was also significantly associated to PTLD. There was no association with age, rejection episodes, steroid-resistant rejection, prior cytomegalovirus infection, HLA mismatch, living donor or cadaveric organ transplantation, United Network for Organ Sharing status at the time of orthotopic liver transplant, and primary or rescue tacrolimus treatment. A significant increase of total gamma-globulin level occurred in PTLD patients, and mono/oligoclonal production was significantly associated to PTLD. CONCLUSION: In EBV-infected pediatric liver transplant recipients, use of OKT3 or antithymocyte globulin and high tacrolimus blood levels are risk factors for a significant increase in the incidence of PTLD. An increase in total gamma-globulin level and appearance of mono/oligoclonal immunoglobulin production are the major preliminary signs of the syndrome.

Child↗

The dramatic reality of biliary tract injury during laparoscopic cholecystectomy. An anonymous multicenter Belgian survey of 65 patients.

BACKGROUND: Most reports concerning the outcome of patients with biliary tract injury during laparoscopic cholecystectomy come from tertiary referral centers, and results could be very different in the everyday practice of community surgeons. OBJECTIVE: The objective is to define the presentation, mechanisms, results of treatment, and long-term outcome of biliary tract injuries during laparoscopic cholecystectomy in the setting of a community surgeon's practice. METHODS: An anonymous retrospective multicenter survey of 9,959 patients who underwent laparoscopic cholecystectomy was conducted by the Belgian Group for Endoscopic Surgery, composed mainly of community general surgeons. RESULTS: Sixty-five patients with bile duct injury were reported on; the incidence was 0.5%, varying from 0. 35 to 1.3% according to the experience of the surgeon. Thirty-four percent of ductal injuries occurred with experienced surgeons, often in association with local predisposing risk factors. Injury occurred in 87% of cases during dissection of the Calot triangle, with severe injury occurring in 46% of patients. Intraoperative cholangiography was performed in 34% of patients and was associated with a significantly improved operative detection rate of injury (68% vs 32%, p = 0.007). Operative detection of injury occurred in 45% of patients; diffuse bile ascitis was encountered postoperatively in 29%. The overall mortality was 9%, the postoperative biliary complication rate 31%, and the reintervention rate 14%. During a median follow-up of 49 months (range, 3-78 months), 20 of the 61 surviving patients (33%) had recurrent biliary strictures. Multivariate analysis demonstrated that the age of the patient (odds ratio: 0.893) and the presence of biliary peritonitis (odds ratio: 0.061) were independent predictive factors for mortality and that the age of the patient (odds ratio: 1.049) and the occurrence of postoperative biliary complications (odds ratio: 0.161) after the initial biliary repair were independent predictive factors for late biliary stricture. CONCLUSIONS: Biliary tract injury is associated with significant mortality and complications in the practice of Belgian community surgeons. Intraoperative detection of ductal injury by the routine use and a correct interpretation of intraoperative cholangiography improved outcome. The impact of the primary biliary repair on long-term outcome is an argument to refer these patients to specialized multidisciplinary experts. The results highlight the importance of surgical experience, proper selection of patients for laparoscopic cholecystectomy, and conversion to laparotomy in difficult cases.

Adult↗

Systematic analysis of in-patients' circumstances and causes of death: a tool to improve quality of care.

OBJECTIVES: To point out actions improving quality of care from a systematic analysis of causes and circumstances of death of hospital patients. DESIGN: All in-hospital patient deaths during 1993 and 1994. SETTING: Saint Luc University hospital. MAIN OUTCOME MEASURES: Immediate and original causes of death, other diagnoses or procedures, circumstances of death, place, members of hospital staff, family or friends with the patient, mention of "do not resuscitate", of unexpected death, of problems during the process of care and of autopsy performed. RESULTS: The mean age of the patients was 60 years. The proportion of men was 57%. The majority of patients died in their room. No family or friends, or members of hospital staff were observed for 17%. "Do no resuscitate" was mentioned for 38% of the patients and the proportion of unexpected death and autopsy was 15% and 28% respectively. The most frequent causes of death were malignant and cardiovascular diseases. At least one of the following diseases was mentioned on 14% of the forms; complications during care, septicaemia, pulmonary embolism, adverse effects of drugs or pressure ulcer. Mean length of hospital stay was 14.7 days. CONCLUSIONS: A systematic analysis of the causes and circumstances of death reveals the epidemiology of hospital deaths and highlights specific diseases, complications or circumstances that could be changed. This study creates the opportunity for possible further action, such as improvement in prevention of pulmonary embolism and support of the members of staff or the friends and family of the patient at the time of death.

Aged↗

Fifteen years of inpatient care in an academic division of general internal medicine: 1980-1994. Trends over time in patient's diagnoses, case-severity, case-complexity and mortality rate.

We describe the trends over time in patient's diagnoses, case-complexity, case-severity, length of stay and mortality rate during the last 15 years in an academic division of general internal medicine (GIM). Our study shows that GIM patients presented with a broad spectrum of diseases. Moreover, important changes were observed in the patient characteristics, i.e. a progressive increase in urgent admissions, severe medical conditions and elderly population. This evolution was associated with a significant rise in case-severity and case-complexity which explains the observed increase in hospital mortality rate. These variables should be accounted for when analyzing processes and outcomes of inpatient medical care in internal medicine.

Academic Medical Centers↗

Metabolization of iron by plant cells using O-Trensox, a high-affinity abiotic iron-chelating agent.

A synthetic siderophore, O-Trensox (L), has been designed and synthesized to improve iron nutrition of plants. The affinity for iron of this ligand [pFe(III) = 29.5 and pFe(II) = 17.9] is very high compared with EDTA. In spite of its high and specific affinity for iron, O-Trensox was found to be able to prevent, and to reverse, iron chlorosis in several plant species grown in axenic conditions. It also allows the iron nutrition and growth of Acer pseudoplatanus L. cell suspensions. The rate of iron metabolization was monitored by 59Fe radioiron. Ferritins, the iron storage proteins, are shown to be the first iron-labelled proteins during iron metabolization and to be able to further dispatch the metal. Using Fe(III)-Trensox, the rate of iron incorporation into ferritin was found to be higher than when using Fe-EDTA, but slower than with Fe-citrate, the natural iron carrier in xylem. During a plant cell culture, the extracellular concentrations of iron complex and free ligand were measured; changes in their relative amounts showed that the iron complex is dissociated extracellularly and that only iron is internalized. This suggests a high affinity for iron of a putative carrier on the plasmalemma. In contrast with Fe-citrate and Fe-EDTA complexes, Fe(III)-Trensox is not photoreducible. Its ability to induce radical damage as a Fenton reagent was tested using supercoiled DNA as target molecule. Unlike Fe-citrate and Fe-EDTA, Fe(II)-Trensox and Fe(III)-Trensox were proven to be harmless even during ascorbate-driven reduction, while Fe-EDTA and Fe-citrate generate heavy damage to DNA.

Chemical Phenomena↗

Development of standards and data quality control.

Health care expenses represent 6 to 10% of the Gross National Product in most European countries. This budget exceeds by far those devoted to Defence or Education. The rising cost of health care concerns all governments. In each country of the European Community, measures were and will further be taken in order to increase efficiency in the delivery of health care. Recent advances in information technology offer new opportunities to collect, process and exchange data to document health practices. In Belgium the Ministry of Public Health collects uniform medical summaries for all acute care hospital inpatients, while detailed health care activities are documented for each patient through a very precise billing system. The use of Minimal Clinical Data and Minimal Nursing Data Sets in hospitals became mandatory four years ago. The fundaments for any data collection is reliability, no matter what the preconceived aim was.

Belgium↗

Hospital comparisons using a Euro Health Data Base for resource management and strategic planning.

A European approach for resource management and strategic planning has been implemented in the HOSCOM project of AIM by defining information standards needed across countries, as well as a methodology to measure resources and costs at the institutional and interinstitutional level. A Euro Health Data Base (EHDB) has been obtained in order to test data availability and comparability as well as to validate models through macrocomparisons using case-mix (DRG's, refined grouping, disease staging) and microcomparisons based on three diseases (cardiac valve replacement, diabetes mellitus and hip fracture). The EHDB's presently based on 274 164 medical record summaries sampled from 7 countries allowed us to build prototypes (using Clipper, Prolog and SQL) in order to export uniform aggregates in the different countries, with standard software tools for statistical comparisons. It showed the present feasibility of using case-mix based on the European Minimum Basic Data Set (MBDS) and the difficulty of obtaining uniform data on resources and costs other than length of stay across countries. Medical data confidentiality was assured but not yet population-based representativity. Given the present state of the EHDB, problems have been clearly identified in order to be solved by international research and development projects in the near future.

Abstracting and Indexing↗

A new bacterial alcohol dehydrogenase active on degraded lignin and several low molecular weight aromatic compounds.

A new intracellular bacterial dehydrogenase has been purified. It was active in the reversible reduction by NADH of conjugated carbonyl groups in partially degraded lignin. It was also active on various aromatic aldehydes such as vanillin, syringaldehyde and cinnamaldehyde, but had no effect on acetovanillone and lignin models carrying a conjugated ketone. It is proposed that this enzyme functions as a broadly specific lignin dehydrogenase at the level of aldehydic groups that are present in the lignin preparations.

Acrolein↗

A new bacterial dehydrogenase oxidizing the lignin model compound guaiacylglycerol beta-O-4-guaiacyl ether.

A lignin model compound, named in short guaiagylglycerol beta-guaiacyl ether (GGE), contains the beta-0-4 ether linkage that is common in the chemical structure of lignin. A Pseudomonas sp. (GU5) had been isolated as an organism able to grow with GGE as the sole source of carbon and energy. When grown on vanillate, the bacteria contained a NAD+ -dependent dehydrogenase converting GGE to a 355 nm absorbing product. The enzyme, named GGE-dehydrogenase, was purified about 160-fold using gel permeation, ion exchange on DEAE-Sephadex, and dye-ligand affinity chromatography. The new protein was about 52 kDa in apparent size with but one polypeptide chain after denaturation and reduction. According to several criteria, the product of GGE oxidation (Km = 12 microM) was identified as the corresponding conjugated ketone at the alpha-carbon of the C3 side-chain. The secondary alcohol function in GGE was apparently the sole target of the enzyme action. However the conversion of GGE into ketone catalyzed by the enzyme was only partial, and did not exceed 50%, probably because only one of the alpha-enantiomers was susceptible to enzyme attack. In contrast the ketone, either made by organic synthesis or by enzymic oxidation of GGE, could be totally reduced back to GGE (Km = 13 microM at pH 8.4, 8 microM at neutral pH), with NADH as the reductant, as confirmed by UV absorption and NMR spectra. Other model compounds with no primary alcoholic function, ether linkage or phenolic group were also substrates for the enzyme, confirming the specificity of GGE-dehydrogenase for the alpha-carbon position. Conjugation of the alpha-ketone with an adjacent phenolic nucleus interfered strongly with equilibrium constants and redox potentials of the system according to pH, and the enzyme displayed widely different optima with pH over 9 when oxidizing GGE, below 7 when reducing the ketone. Equilibrium studies showed that the ketone/GGE potential was -0.37 volt at pH 8.7, -0.23 volt at pH 7 (30 degrees C). The significance of this new dehydrogenase and its properties are discussed, especially in the general concern of lignin biodegradation.

Bacteria↗

Predictive factors of thyroid carcinoma in non-toxic multinodular goitre.

The management of nontoxic multinodular goitre (NMNG) remains controversial. The challenge for the clinician is to identify the small proportion of NMNG patients with associated thyroid carcinoma who would thus benefit from surgery. We studied retrospectively the medical records of 80 patients with NMNG and coexisting thyroid carcinoma who underwent total thyroidectomy. Eighty total thyroidectomy patients with NMNG whose histology was benign were then randomnly chosen as controls. In univariate analysis, the following parameters were significantly more frequent in the carcinoma group: rapid growth of the goitre (p = 0.002), presence of microcalcifications (p = 0.01), hypoechogenicity (p = 0.02), firm consistency of a nodule (p = 0.03), and presence of a dominant cold nodule on scintigraphy (p = 0.03). In the multiple regression analysis, the variables significantly associated with carcinoma were rapid growth (Odds ratio (OR) = 4.13, 95% confidence interval(CI): 1.72-9.89), hypo-echogenicity (OR = 3.11, 95% CI: 1.13-8.51) and the presence of a dominant nodule (OR = 2.26, 95% CI: 1.06-4.79)). In the cancer group, tumour size was positively correlated with compression signs (p = 0.01), age (p = 0.02), the presence of a dominant nodule on scintigraphy (p = 0.02), and with rapid growth (p = 0.04). Concerning nodule size estimated on US (ultrasound), the majority (65%) of patients without carcinoma had nodules < 3 cm, whereas 73% of patients with clinical thyroid carcinoma (> or = 1 cm on histology) had nodules with a diameter of > or = 3 cm on US (p = 0.02). In conclusion, our study suggests that surgical treatment of NMNG should be proposed in the presence of rapid nodular growth, compression signs, dominant nodule on scintigraphy, nodule size > or 3 cm and hypo-echogenicity.

Adult↗