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C Berger

Publications and source records attributed to C Berger.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Are there physical, technical and morphological limits to conformational radiotherapy?].

Conformal radiotherapy results from several technical and data processing advances. The treatment planning and the daily treatments have benefited from a significant improvement of the quality control. However, all the steps of the process contain various limitations of varying effects. It appear important to identify, describe and exploit those limits to better drive the procedures and optimise the quality. Identifying the limits of the conformal radiotherapy should be an important help to implement intensity modulation radiotherapy.

Anthropometry↗
PubMed2000

Canadian normative data for the SF-36 health survey. Canadian Multicentre Osteoporosis Study Research Group.

BACKGROUND: The Medical Outcomes Study 36-item Short Form (SF-36) is a widely used measure of health-related quality of life. Normative data are the key to determining whether a group or an individual scores above or below the average for their country, age or sex. Published norms for the SF-36 exist for other countries but have not been previously published for Canada. METHODS: The Canadian Multicentre Osteoporosis Study is a prospective cohort study involving 9423 randomly selected Canadian men and women aged 25 years or more living in the community. The sample was drawn within a 50-km radius of 9 Canadian cities, and the information collected included the SF-36 as a measure of health-related quality of life. This provided a unique opportunity to develop age- and sex-adjusted normative data for the Canadian population. RESULTS: Canadian men scored substantially higher than women on all 8 domains and the 2 summary component scales of the SF-36. Canadians scored higher than their US counterparts on all SF-36 domains and both summary component scales and scored higher than their UK counterparts on 4 domains, although many of the differences are not large. INTERPRETATION: The differences in the SF-36 scores between age groups, sexes and countries confirm that these Canadian norms are necessary for comparative purposes. The data will be useful for assessing the health status of the general population and of patient populations, and the effect of interventions on health-related quality of life.

Activities of Daily Living↗
PubMed2000

[Prevention of venous thromboembolism in polytraumatized patients. Epidemiology and importance].

OBJECTIVE: Unfractionated heparin, low-molecular-weight heparin (LMWH), mechanical compression, and vena cava filters are part of a large panel of chemical or physical methods proposed to trauma patients as prophylaxis against venous thromboembolism. This prophylactic strategy is based on a 1961 autopsy survey showing a 16.6% rate of pulmonary embolism in this population. The objective of this study was to assess the incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE) in multiple trauma patients. METHODS: A Medline and Current Contents search was conducted for prospective studies including trauma patients with ISS > 9 whose incidence of DVT and PE was evaluated by contrast venography and/or duplex scan and by ventilation/perfusion lung scan and/or pulmonary angiography and/or autopsy, respectively. RESULTS: Twelve studies met the selection criteria for DVT. Among the global population of 2,374 trauma patients (14% of all admissions) 47% suffered lower limb injury and 17% had severe head injury. Overall incidence of DVT was about 20%. It was about 38% in patients without prophylaxis (range 2 to 61.5%) and about 13% in patients with prophylaxis (range 0.8 to 37%). Similar variations were observed for proximal DVT. In comparative studies (unfractionated heparin versus LMWH or versus mechanical compression devices), the incidence of thromboembolic events varied from 3.2 to 44% in patients given unfractionated heparin, 0.8 to 31% in those given LMWH, and 3.1% to 12% with mechanical compression. Thirteen studies met the selection criteria for PE and included an overall population of 4,245 trauma patients where the diagnosis of PE was suspected only if the patient had clinical signs. The incidence of PE and fatal PE was about 1.4% and 0.3% respectively. Only one study systematically studied the presence of PE and showed an incidence of 18.7% for PE in a population of 32 patients. DISCUSSION: The current literature reports wide variability in methodology, characteristics of the study population and prophylaxis. These differences explain the wide variability from one study to another in the risk factors for venous thrombosis identified by univariate and multivariate analysis. CONCLUSION: Current methodological imperfections make it impossible to correctly assess the incidence of DVT and PE in the multiple trauma population. Studies with a rigorous methodology using a precise stratification of the trauma injuries are required to determine the real risk for DVT/PE in trauma patients and to assess the impact of early systematic prophylaxis.

Adolescent↗
PubMed2000

Estimation of the prevalence of low bone density in Canadian women and men using a population-specific DXA reference standard: the Canadian Multicentre Osteoporosis Study (CaMos).

The Canadian Multicentre Osteoporosis Study (CaMos) is a prospective cohort study which will measure the incidence and prevalence of osteoporosis and fractures, and the effect of putative risk factors, in a random sample of 10,061 women and men aged > or = 25 years recruited in approximately equal numbers in nine centers across Canada. In this paper we report the results of studies to establish peak bone mass (PBM) which would be appropriate reference data for use in Canada. These reference data are used to estimate the prevalence of osteoporosis and osteopenia in Canadian women and men aged > or = 50 years. Participants were recruited via randomly selected household telephone listings. Bone mineral density (BMD) of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry using Hologic QDR 1000 or 2000 or Lunar DPX densitometers. BMD results for lumbar spine and femoral neck were converted to a Hologic base. BMD of the lumbar spine in 578 women and 467 men was constant to age 39 years giving a PBM of 1.042 +/- 0.121 g/cm2 for women and 1.058 +/- 0.127 g/cm2 for men. BMD at the femoral neck declined from age 29 years. The mean femoral neck BMD between 25 and 29 years was taken as PBM and was found to be 0.857 +/- 0.125 g/cm2 for women and 0.910 +/- 0.125 g/cm2 for men. Prevalence of osteoporosis, as defined by WHO criteria, in Canadian women aged > or = 50 years was 12.1% at the lumbar spine and 7.9% at the femoral neck with a combined prevalence of 15.8%. In men it was 2.9% at the lumbar spine and 4.8% at the femoral neck with a combined prevalence of 6.6%.

Absorptiometry, Photon↗
PubMed2000

MRI and CT of a haemangioma of the mandible in Kasabach-Merritt syndrome.

Since the description in 1940 of Kasabach-Merritt syndrome (KMS) in patients with capillary haemangiomas, several other vascular tumours have been recognised as possible causes of this coagulopathy. The literature suggests a specific histological pattern of vascular tumours responsible for KMS, excluding capillary haemangioma [1]. There is an extensive literature on, haemangiomas accompanied by thrombocytopenia, and imaging of thrombosis in the lesion, especially cavernous haemangioma of the liver. However, no report has described a haemangioma of the mandible in the acute stage of the coagulopathy, or serial examinations of such a lesion. We report the features of a mandible lesion with KMS and discusses the interpretations of the changes observed.

Child, Preschool↗
PubMed2000

Flavour sulphides are produced from methionine by two different pathways by Geotrichum candidum.

We have investigated the capacities of Geotrichum candidum strains to produce sulphides from methionine. This attribute is very important in cheese technology because of the flavouring potential of sulphur compounds. A spectrophotometric procedure using 5,5'-dithiobis(2-nitrobenzoic acid) to determine sulphides was tested on a collection of G. candidum strains, and confirmed by gas chromatography-mass spectrometry. The strains were distinguished on the basis of their ability to produce methanethiol. Gas chromatography-mass spectrometry also made it possible to identify other sulphides, such as dimethyl disulphide, dimethyl trisulphide and dimethyl sulphide. Using sonicated cells, the specific production of these four sulphides was studied in presence of L-[S-methyl-2H]methionine. Both methanethiol and dimethyl sulphide were produced from methionine, but two different pathways were used by G. candidum.

Cheese↗
PubMed2000

In vitro release of vancomycin and tobramycin from impregnated human and bovine bone grafts.

In order to combine the effects of bone repair and eradication of infection, with both Gram-positive and Gram-negative pathogens, the behaviour of a compound of bone graft and antibiotics was investigated. Samples of human and bovine bone, cancellous and cortical, were processed and incubated with vancomycin and tobramycin, respectively. The compound was placed in 5% human albumin and the surrounding liquid was exchanged completely every 24 h. Concentrations of antibiotics in the fluid were measured over < or = 28 days using high pressure liquid chromatography and a bioassay. All tested combinations eluted mainly in the initial phase with a logarithmic decrease over the testing period. The concentration of antibiotics in the albumin was well above the MIC for common pathogens throughout the investigation in all tested specimens. The highest initial concentrations were measured in the compound of bovine bone together with vancomycin (24395.8 +/- 1138.9 mg/L), decreasing to 9.02 +/- 1.3 mg/L after 11 exchanges. Human and bovine bone did not have significantly different properties. The storage capability of cortical bone was generally lower than that of cancellous bone. Tobramycin concentrations were significantly lower in the initial phase; however, it eluted more steadily and over a longer period, so that from day 6 onwards, its concentration was greater than that of vancomycin. After 28 days, the tobramycin concentration was 18.09 +/- 2.46 mg/L (bovine cancellous bone). In conclusion, bone, if processed adequately, is an excellent carrier for vancomycin and tobramycin. Cortical bone is as suitable as cancellous bone. The pharmacokinetics of human and bovine bone are comparable. Using an antibiotic-graft compound, eradication of pathogens and grafting of bony defects may be accomplished in a one-stage procedure.

Animals↗
PubMed2000

Expression of herpes simplex virus ICP47 and human cytomegalovirus US11 prevents recognition of transgene products by CD8(+) cytotoxic T lymphocytes.

The in vivo persistence of gene-modified cells may be limited by the development of a host immune response to vector-encoded proteins. Herpesviruses evade cytotoxic T-lymphocyte (CTL) recognition by expressing genes which interfere selectively with presentation of viral antigens by class I major histocompatibility complex (MHC) molecules. Here, we studied the use of retroviral vectors encoding herpes simplex virus ICP47, human cytomegalovirus (HCMV) US3, or HCMV US11 to decrease presentation of viral proteins and transgene products to CD8(+) CTL. Human fibroblasts and T cells transduced to express the ICP47, US3, or US11 genes alone exhibited a decrease in cell surface class I MHC expression. The combination of ICP47 and US11 rendered fibroblasts negative for surface class I MHC and allowed a class I MHC-low population of T cells to be sorted by flow cytometry. Fibroblasts and T cells expressing both ICP47 and US11 were protected from CTL-mediated lysis and failed to stimulate specific memory T-cell responses to transgene products in vitro. Our findings suggest that expression of immunoregulatory viral gene products could be a potential strategy to prolong transgene expression in vivo.

Animals↗
PubMed2000

LMCE3 treatment strategy: results in 99 consecutively diagnosed stage 4 neuroblastomas in children older than 1 year at diagnosis.

PURPOSE: To tailor postinduction therapy for stage 4 neuroblastoma in children who are older than 1 year at diagnosis according to status after induction. PATIENTS AND METHODS: From March 1987 to December 1992, 99 patients who were consecutively admitted were included in the Lyon-Marseille-Curie East of France (LMCE)3 strategy. After induction with the French Society of Pediatric Oncology NB87 regimen and surgery, patients who were in complete remission immediately proceeded to consolidation therapy with vincristine, melphalan, and fractionated total-body irradiation (VMT). All other patients underwent a postinduction strategy before VMT, either an additional megatherapy regimen or further chemotherapy with etoposide/carboplatin. RESULTS: The progression-free survival (PFS) is 29% at 7 years from diagnosis, which compares favorably with that of a similar cohort of 72 patients previously reported by our group (LMCE1; PFS of 20% at 5 years and 8% at 14 years, P =.004). In the multivariate analysis, only age younger than 3 years at diagnosis (P =.0085) and achievement of complete or very good partial remission after NB87 and surgery (P =.00024) remained significant. The PFS of the 87 patients who were included in the postinduction strategy was significantly better than that of the comparable 62 patients on the LMCE1 study (32% v 11% at 7 years; P =.005). CONCLUSION: The progressive improvements in the LMCE results over the last 10 years suggest that improvements in supportive care measures and increases in each component of this strategy (induction, postinduction, consolidation) may all contribute to increased survival rates.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Latent membrane protein 1 associated signaling pathways are important in tumor cells of Epstein-Barr virus negative Hodgkin's disease.

The latent membrane protein 1 (LMP1) oncogene of Epstein-Barr virus (EBV) is selectively expressed in the Reed-Sternberg (RS) cells of EBV-associated Hodgkin's disease (HD). However, no differences in clinical presentation and course are found between EBV positive and EBV negative forms of HD suggesting a common pathogenetic mechanism. We have studied the LMP1 associated signaling pathways and their dominant negative inhibition in the myelomonocytic HD-MyZ and the B-lymphoid L-428 HD cell lines. In both EBV negative cell lines expression of LMP1 is associated with the formation of multinuclear RS cells. Dominant negative inhibition of NF-kappa B mediated signaling at the step of I kappa B-alpha phosphorylation results in increased cell death with only a few typical RS cells resistant to overexpression of the dominant negative inhibitor I kappa B-alpha-N delta 54. However, dominant negative inhibition of NF-kappa B mediated signaling at the early step of TRAF2 interaction results in the formation of multinuclear cells in both cell lines and, in addition, in clusters of small mononuclear cells in the HD-MyZ cell line. In HD-MyZ cells overexpression of the powerful JBD-inhibitor of the JNK signal transduction pathway is restricted to small cells and never observed in RS cells. These small cells undergo apoptosis as shown by the TUNEL technique. Apoptosis of small cells is still observed after co-transfection of JBD and LMP1 but in addition a few apoptotic HD-MyZ cells with large fused nuclear masses are identified suggesting that specific inhibition of JNK leads also to apoptosis of LMP1 induced RS cells. Thus, activation of the JNK signaling pathway is also important in the formation of Reed-Sternberg cells. Our findings are consistent with a model where all three LMP1 associated functions, i.e. NF-kappa B mediated transcription, TRAF2 dependent signaling, and c-Jun activation act as a common pathogenetic denominator of both EBV negative and EBV positive HD.

Herpesvirus 4, Human↗
PubMed1999

Nucleotide binding to creatine kinase: an isothermal titration microcalorimetry study.

We investigated the binding of ATP in the presence and absence of Mg(2+) to dimeric muscle creatine kinase (CK) by isothermal titration microcalorimetry as a function of pH and temperature. The thermodynamic parameters for these events show that (1) binding of nucleotide to the CK active site does not involve proton exchange with the buffer and (2) the active sites are the only nucleotide binding sites on CK. Interdependence of the active sites in the dimer could not be demonstrated. As CK undergoes major structural changes upon Mg-nucleotide binding, a thermodynamic cycle was employed to calculate the contributions of domain movements to the observed enthalpies.

Animals↗
PubMed1999

Sequence polymorphisms between latent membrane proteins LMP1 and LMP2A do not correlate in EBV-associated reactive and malignant lympho-proliferations.

The latent membrane proteins LMP1 and LMP2A are co-expressed in most malignancies associated with Epstein-Barr virus (EBV). In contrast with the transforming LMP1 oncoprotein, LMP2A is expressed in lymphocytes of healthy EBV carriers and considered to maintain viral latency. Critical for these LMP2A functions are a transmembranous epitope recognized by specific cytotoxic T lymphocytes (CTLs) and the N-terminal immunoreceptor tyrosine-based activation motif (ITAM), blocking B-cell receptor signaling. To characterize ITAM and CTL motifs of LMP2A and to correlate them with C-terminal variants of LMP1 including the 30-bp deletion variant (LMP1delta), comparative sequence analysis was performed on 76 samples from patients with reactive and malignant lympho-proliferation (infectious mononucleosis, n=21; tonsillar hyperplasia, n=16, chronic lympho-proliferation, n = 9; Hodgkin's disease, n = 8; Non-Hodgkin's lymphoma, n = 5; AIDS-related large-cell lymphoma, n=17). The CTL motif was conserved in all but 2 cases (C426-->S). The ITAM motif was characterized by strictly conserved YXXL sequences in all cases, with a sequence polymorphism in between. The B95.8 prototype was found in 17% (13/76) of cases, while in 72% a variant with 3 point mutations (166796 C-->A, 166805 C-->A, 166810 C-->T) was detected; 11% had 1 or 2 of these mutations in addition to G-->A at 166793. In the C terminus of LMP1, a hypervariable region including LMP1delta was described in 61% of cases. There was no significant association of a particular LMP2A variant with either malignant phenotype or LMP1delta, demonstrating that the functional domains of LMP2A are conserved and that the sequence polymorphisms in LMP1 and LMP2A are independent.

Conserved Sequence↗
PubMed1999

Antigen recognition by conformational selection.

Conformational adaptation between antigen and antibody can modulate the antibody specificity. The phenomenon has often been proposed to result from an 'induced fit', which implies that the binding reaction induces a conformational change in the antigen and the antibody. Thus, an 'induced fit' requires initial complex formation followed by a conformational change in the complex. However, an antibody may select those antigen molecules that happen to be in a fitting conformational state. This leads to the same end result as an induced fit. Here, we demonstrate conformational selection by a single chain antibody fragment, raised against a random coil variant of the leucine zipper domain of transcription factor GCN4, when it cross-reacts with the wild-type dimeric leucine zipper. Kinetic and equilibrium data show that the single chain antibody fragment fragment selects monomeric peptides from the population in equilibrium with the leucine zipper dimer.

Amino Acid Sequence↗
PubMed1999

Monitoring regional lung ventilation by functional electrical impedance tomography during assisted ventilation.

A new approach in discriminating the regional air volume changes in the lungs associated with either spontaneous or mechanical ventilation during assisted ventilation is presented. Impedance data are obtained by conventional electrical impedance tomography (EIT). The data are filtered in the range of either the spontaneous or the ventilator rate and processed by the functional EIT (f-EIT) evaluation technique, whereby the variation of the respective EIT data with time is determined and imaged. EIT measurements performed in an infant during synchronized intermittent mandatory ventilation were evaluated with this method and indicated that the specific local lung volume swings related to spontaneous and mechanical inhalations can be separated and imaged as tomograms. This noninvasive approach may become useful in optimizing the ventilatory pattern during advanced forms of artificial ventilation and may help the clinician in the therapy management of individual patients.

Blood Gas Analysis↗