How to set up and apply reference levels in fluoroscopy at a national level.

A nationwide survey was launched to investigate the use of fluoroscopy and establish national reference levels (RL) for dose-intensive procedures. The 2-year investigation covered five radiology and nine cardiology departments in public hospitals and private clinics, and focused on 12 examination types: 6 diagnostic and 6 interventional. A total of 1,000 examinations was registered. Information including the fluoroscopy time (T), the number of frames (N) and the dose-area product (DAP) was provided. The data set was used to establish the distributions of T, N and the DAP and the associated RL values. The examinations were pooled to improve the statistics. A wide variation in dose and image quality in fixed geometry was observed. As an example, the skin dose rate for abdominal examinations varied in the range of 10 to 45 mGy/min for comparable image quality. A wide variability was found for several types of examinations, mainly complex ones. DAP RLs of 210, 125, 80, 240, 440 and 110 Gy cm2 were established for lower limb and iliac angiography, cerebral angiography, coronary angiography, biliary drainage and stenting, cerebral embolization and PTCA, respectively. The RL values established are compared to the data published in the literature.

Variable viral clearance despite adequate ganciclovir plasma levels during valganciclovir treatment for cytomegalovirus disease in D+/R- transplant recipients.

ABSTRACT: BACKGROUND: Valganciclovir, the oral prodrug of ganciclovir, has been demonstrated equivalent to iv ganciclovir for CMV disease treatment in solid organ transplant recipients. Variability in ganciclovir exposure achieved with valganciclovir could be implicated as a contributing factor for explaining variations in the therapeutic response. This prospective observational study aimed to correlate clinical and cytomegalovirus (CMV) viral load response (DNAemia) with ganciclovir plasma concentrations in patients treated with valganciclovir for CMV infection/disease. METHODS: Seven CMV D+/R- transplant recipients (4 kidney, 2 liver and 1 heart) were treated with valganciclovir (initial dose was 900-1800 mg/day for 3-6.5 weeks, followed by 450-900 mg/day for 2-9 weeks). DNAemia was monitored by real time quantitative PCR and ganciclovir plasma concentration was measured at trough (Ctrough) and 3 h after drug administration (C3h) by HPLC. RESULTS: Four patients presented with CMV syndrome, two had CMV tissue-invasive disease after prophylaxis discontinuation, and one liver recipient was treated pre-emptively for asymptomatic rising CMV viral load 5 weeks post-transplantation in the absence of prophylaxis. CMV DNAemia decreased during the first week of treatment in all recipients except in one patient (median decrease: -1.2 log copies/mL, range: -1.8 to 0) despite satisfactory ganciclovir exposure (AUC0-12 = 48 mg.h/L, range for the 7 patients: 40-118 mg.h/L). Viral clearance was obtained in five patients after a median of time of 34 days (range: 28-82 days). Two patients had recurrent CMV disease despite adequate ganciclovir exposure (65 mg.h/L, range: 44-118 mg.h/L). CONCLUSIONS: Valganciclovir treatment for CMV infection/disease in D+/R- transplant recipients can thus result in variable viral clearance despite adequate ganciclovir plasma concentrations, probably correlating inversely with anti-CMV immune responses after primary infection.

Collective victimisation and collective guilt in the former Yugoslavia : the interplay between individual, local and societal levels

The thesis examines the impact of collective war victimization on individuals' readiness to accept or assign collective guilt for past war atrocities. As a complement to previous studies, its aim is to articulate an integrated approach to collective victimization, which distinguishes between individual-, communal-, and societal-level consequences of warfare. Building on a social representation approach, it is guided by the assumption that individuals form beliefs about a conflict through their personal experiences of victimization, communal experiences of warfare that occur in their proximal surrounding, and the mass- mediatised narratives that circulate in a society's public sphere. Four empirical studies test the hypothesis that individuals' beliefs about the conflict depend on the level and type of war experiences to which they have been exposed, that is, on informative and normative micro and macro contexts in which they are embedded. The studies have been conducted in the context of the Yugoslav wars that attended the breakup of Yugoslavia, a series of wars fought between 1991 and 2001 during which numerous war atrocities were perpetrated causing a massive victimisation of population. To examine the content and impact of war experiences at each level of analysis, the empirical studies employed various methodological strategies, from quantitative analyses of a representative public opinion survey, to qualitative analyses of media content and political speeches. Study 1 examines the impact of individual- and communal- level war experiences on individuals' acceptance and assignment of collective guilt. It further examines the impact of the type of communal level victimization: exposure to symmetric (i.e., violence that similarly affects members of different ethnic groups, including adversaries) and asymmetric violence. The main goal of Study 2 is to examine the structural and political circumstances that enhance collective guilt assignment. While the previous studies emphasize the role of past victimisation, Study 2 tests the assumption that the political demobilisation strategy employed by elites facing public discontent in the collective system-threatening circumstances can fuel out-group blame. Studies 3 and 4 have been conducted predominantly in the context of Croatia and examine rhetoric construction of the dominant politicized narrative of war in a public sphere (Study 3) and its maintenance through public delegitimization of alternative (critical) representations (Study 4). Study 4 further examines the likelihood that highly identified group members adhere to publicly delegitimized critical stances on war. - Cette thèse étudie l'impact de la victimisation collective de guerre sur la capacité des individus à accepter ou à attribuer une culpabilité collective liée à des atrocités commises en temps de guerre. En compléments aux recherches existantes, le but de ce travail est de définir une approche intégrative de la victimisation collective, qui distingue les conséquences de la guerre aux niveaux individuel, régional et sociétal. En partant de l'approche des représentations sociales, cette thèse repose sur le postulat que les individus forment des croyances sur un conflit au travers de leurs expériences personnelles de victimisation, de leurs expériences de guerre lorsque celle-ci se déroule près d'eux, ainsi qu'au travers des récits relayés par les mass media. Quatre études testent l'hypothèse que les croyances des individus dépendent des niveaux et des types d'expériences de guerre auxquels ils ont été exposés, c'est-à-dire, des contextes informatifs et normatifs, micro et macro dans lesquels ils sont insérés. Ces études ont été réalisées dans le contexte des guerres qui, entre 1991 et 2001, ont suivi la dissolution de la Yougoslavie et durant lesquelles de nombreuses atrocités de guerre ont été commises, causant une victimisation massive de la population. Afin d'étudier le contenu et l'impact des expériences de guerre sur chaque niveau d'analyse, différentes stratégies méthodologiques ont été utilisées, des analyses quantitatives sur une enquête représentative d'opinion publique aux analyses qualitatives de contenu de médias et de discours politiques. L'étude 1 étudie l'impact des expériences de guerre individuelles et régionales sur l'acceptation et l'attribution de la culpabilité collective par les individus. Elle examine aussi l'impact du type de victimisation régionale : exposition à la violence symétrique (i.e., violence qui touche les membres de différents groupes ethniques, y compris les adversaires) et asymétrique. L'étude 2 se penche sur les circonstances structurelles et politiques qui augmentent l'attribution de culpabilité collective. Alors que les recherches précédentes ont mis l'accent sur le rôle de la victimisation passée, l'étude 2 teste l'hypothèse que la stratégie de démobilisation politique utilisée par les élites pour faire face à l'insatisfaction publique peut encourager l'attribution de la culpabilité à l'exogroupe. Les études 3 et 4 étudient, principalement dans le contexte croate, la construction rhétorique du récit de guerre politisé dominant (étude 3) et son entretien à travers la délégitimation publique des représentations alternatives (critiques] (étude 4). L'étude 4 examine aussi la probabilité qu'ont les membres de groupe fortement identifiés d'adhérer à des points de vue sur la guerre critiques et publiquement délégitimés.

Prevalence and levels of IgG and IgM antibodies against Plasmodium falciparum and P. vivax in blood donors from Rondônia, Brazilian Amazon

Antibodies of IgG and IgM isotopes reacting with Plasmodium falciparum and P. vivax thick-smear antigens were searched for by the indirect fluorescent antibody test (IFAT) in a random sample of 230 blood donors at the transfusion centre of Porto Velho (HEMERON), Rondônia State, western Brazilian Amazon. A high prevalence of IgG seropositivity (32% against P. falciparum, 24% against P. vivax and 37% against either P. falciparum or P. vivax antigens) was detected among them, despite the fact that candidates reporting recent (<12 months) malaria attacks were not elegible. Only a small proportion of them had also detectable IgM antibodies to these antigens. These data suggest an intense, relatively recent exposure to malaria in such an urban population sample. However, parasitaemia (as detected by microscopical examination of Giemsa-stained thick smears) was patent in only one prospective donor. The antibody profile of blood donors was compared with that of healthy subjects of all age groups, living in a close endemic area (Candeias village, 21 km east of Porto Velho). The villagers were classified into two groups according to their history of a recent (<12 months) or a remote (>12 months) past malaria attack due to either P. falciparum or P. vivax. Extensive overlapping was observed when the distribution of antibody titres of healthy subjects from Candeias village with a recent and remote malaria history was compared. In conclusion, subjects with a recent or a remote malaria history could not be distinguished by sorological criteria alone.

Plasma levels of trimipramine and metabolites in four patients: determination of the enantiomer concentrations of the hydroxy metabolites.

A two-step high-performance liquid chromatography method is described, using a CN column and an alpha 1-acid glycoprotein column, which allows the measurement of the enantiomers of the hydroxy metabolites of trimipramine in plasma of trimipramine-treated patients. Of the four patients analyzed, three showed approximately equimolar concentrations of the (D)- and (L)-enantiomers of the hydroxy metabolites (2-hydroxy-trimipramine and 2-hydroxy desmethyltrimipramine), and one was found to have roughly twice as much of the (L)-form and of the (D)-form of 2-hydroxy trimipramine and 2-hydroxy desmethyltrimipramine. From the data available on the pharmacological effects of the enantiomers of trimipramine, it is postulated that this interindividual variability in its pharmacokinetics is another factor that could contribute to the interindividual variability in its pharmacodynamics.

Trypanosoma cruzi infection in the opossum Didelphis marsupialis: absence of neonatal transmission and protection by maternal antibodies in experimental infections

The high rate of natural Trypanosoma cruzi infection found in opossums does not always correlate with appreciable densities of local triatomid populations. One alternative method which might bypass the invertebrate vector is direct transmission from mother to offspring. This possibility was investigated in five T. cruzi infected females and their litters (24 young). The influence of maternal antibodies transferred via lactation, on the course of experimental infection, was also examined. Our results show that neonatal transmission is probably not responsible for the high rate of natural T. cruzi infection among opossums. In addition antibodies of maternal origin confer a partial protection to the young. This was demonstrated by the finding of a double prepatency period and 4,5 fold lower levels of circulating parasites, in experimentally infected pouch young from infected as compared to control uninfected mothes. On the other hand, the duration of patent parasitemia was twice as long as that observed in the control group.

Determination of human plasma levels of levo-alpha-acetylmethadol and its metabolites by gas chromatography-mass spectrometry.

A gas chromatography-mass spectrometry (GC-MS) method is presented which allows the simultaneous determination of the plasma concentrations of the levo-alpha-acetylmethadol (LAAM) and of its active metabolites (NorLAAM and DiNorLAAM), after derivatization with the reagent trifluoroacetic anhydride (TFAA). No interferences from endogenous compounds were observed following the extraction of plasma samples from 11 different human subjects. The standard curves were linear over a working range of 5-200ng/ml for the three compounds. Recoveries measured at three concentrations ranged from 47 to 67% for LAAM, from 50 to 69% for NorLAAM and from 28 to 50% for DiNorLAAM. Intra- and interday coefficients of variation determined at three concentrations ranged from 5 to 13% for LAAM, from 3 to 9% for NorLAAM and from 5 to 13% for DiNorLAAM. The limits of quantitation of the method were found to be 4ng/ml for the three compounds. No interference was noted from methadone. This sensitive and specific analytical method could be useful for assessing the in vivo relationship between LAAM's blood levels, clinical efficacy and/or cardiotoxicity

An inhibition ELISA to determine alpha macroglobulin levels in mouse plasma

A sensitive method for quantifying mouse plasma alpha-macroglobulins (AM) using an inhibition ELISA is described. AM are important plasmaproteinase inhibitors that possibly act also as immunomodulatory molecules. The standard protocol develope in our experiments involves coating well with 10 µg/ml A2M in carbonate buffer, followed by incubation with a 1:1 (v/v) mixture of the plasma to be tested (diluted 1/1000) and goat anti-AM (diluted 1/1250). This is followed by further incubation, first with the enzyme-conjugated antibody and with the substrate prior to the reading of absorbance levels of the reaction products. Standard curve samples must be included in each plate, employing known amounts of the purified Murine Alpha-2-Macroglobulin (MuA2M) used for coating, with concentrations ranging from 0.001 to 10 µg/ml. Using test samples in triplicates and a 6-point standard curve in a single ELISA plate, 25 plasma samples can be tested accurately. The method offers an useful tool for establishing AM levelsin small samples of mouse plasma.

No role for CSF myelin basic protein levels in patients treated for childhood acute lymphoblastic leukemia

RESUME Introduction : La prophylaxie du système nerveux central lors d'un diagnostic de leucémie lymphoblastique aiguë de l'enfant a permis de réduire le risque de rechute mais a été associée dans certains cas à des neurotoxicités cliniques ou des anomalies radiologiques. Des moyens de prédire ces neurotoxicités font défaut, en particulier en raison de l'absence de corrélation claire entre les signes cliniques et les images radiologiques. Quelques auteurs ont suggéré que les taux de protéine basique de la myéline (MBP) mesurés dans le liquide céphalo-rachidien pouvaient avoir un intérêt dans ce contexte. Uné étude rétrospective de ces taux en relation avec des données cliniques et radiologiques est présentée dans ce travail. Matériel et Méthodes : Les taux de MBP mesurés dans le liquide céphalo-rachidien lors d'administration de chimiothérapie intrathécale, les examens cliniques neurologiques et les rapports radiologiques ont été rétrospectivement étudiés chez nos patients. Les données concernant des difficultés académiques éventuelles, ainsi que le niveau académique atteint ont été récoltées par l'intermédiaire de contacts téléphoniques réguliers organisés dans le cadre du suivi à long terme de nos patients. Résultats : Un total de 1248 dosages de MBP chez 83 patients, 381 examens neurologiques chez 34 patients et 69 rapports d'investigations neuroradiologiques chez 27 patients ont été analysés. Cinquante-deux patients ont eut au moins un taux anormal de MBP. Des anomalies radiologiques ont été décrites chez 47% de ces patients, parmi lesquels 14% ont présenté des difficultés scolaires sous une forme ou sous une autre. La proportion de patients ayant présenté des difficultés scolaires dans les groupes avec taux de MBP normal mais sans anomalies radiologiques décrites ou sans investigations radiologiques étaient respectivement de 0% et 3%, inférieurs dans tous les cas au groupe avec des taux normaux de MBP (100%, 22% and 5% respectivement). Discussion : Tout en prenant en compte les limitations dues à l'aspect rétrospectif de cette étude, nous avons conclu à une utilité limitée de ces dosages systématiques comme indicateur d'une neurotoxicité induite parle traitement dans le contexte de nos patients oncologiques. ABSTRACT Introduction : Central nervous system (CSF) prophylaxis of childhood acute lymphoblastic leukemia has dropped rates of relapses but has been associated wíth neurotoxicity and imaging abnormalities. Predictors of neurotoxícity are lacking, because of inconsistency between clinical symptoms and imaging. Some have suggested CSF Myelin Basic Protein (MBP) levels to be of potential interest. A retrospective analysis of MBP levels in correlation with clinical and radiological data is presented. Materials and Methods : MBP levels obtained at the time of intrathecals, charts, and neuroradiology reports were retrospectively analyzed. Academic achievement data were obtained from phone contacts with patients and families. Results : We retrieved 1248 dosages of MBP in 83 patients, 381 neurological exams in 34 patients and 69 neuroradiological investigations in 27 patients. Fifty-two patients had abnormal MBP levels. Radiological anomalies were present in 47% of those investigated, 14% of them having school difficulties. Proportions of patients with school difficulties in the groups with abnormal MBP levels but no radiological anomalies or with no radiological investigations were 0% and 3% respectively, which was lower than in the group of patients with normal MBP levels (100%, 22% and 5% respectively). Discussion : Notwithstanding the retrospective character of our study, we conclude that there is limited usefulness of systematic dosage of MBP as indicator of treatment-induced neurotoxicity in ALL patients.

AA-amyloidosis caused by visceral leishmaniasis in a human immunodeficiency virus-infected patient.

AA-amyloidosis in the setting of chronic visceral leishmaniasis (VL) has been reported in animal models but documentation in humans is unavailable. Here, we report on a Portuguese man who in 1996 was diagnosed with both human immunodeficiency virus (HIV)-infection and VL. Antiretroviral treatment led to sustained suppression of HIV viremia but CD4+ lymphocytes rose from 8 to only 160 cells/mL. Several courses of antimony treatment did not prevent VL relapses. Renal failure developed in 2006 and renal biopsy revealed AA-amyloidosis. The patient had cryoglobulinemia and serum immune complexes containing antibodies directed against seven leishmanial antigens. Antimony plus amphotericin B, followed by oral miltefosine resulted in a sustained VL treatment response with elimination of circulating Leishmania infantum DNA and CD4+ recovery. The concomitant reduction of serum AA levels and disappearance of circulating leishmanial immune complexes suggests that prolonged VL may lead to AA-amyloidosis in immunocompromised humans.

Induction of circulating tumor-reactive CD8+ T cells after vaccination of melanoma patients with the gp100 209-2M peptide.

Patients with stage I-III melanoma were vaccinated with the modified HLA-A2-binding gp100(209-2M)-peptide after complete surgical resection of their primary lesion and sentinel node biopsy. Cytoplasmic interferon-gamma production by freshly thawed peripheral blood mononuclear cells (direct ex vivo analysis) or by peripheral blood mononuclear cells subjected to 1 cycle of in vitro sensitization with peptide, interleukin-2, and interleukin-15 was measured following restimulation with the modified and native gp100 peptides, and also A2gp100 melanoma cell lines. Peptide-reactive and tumor-reactive T cells were detected in 79% and 66% of selected patients, respectively. Patients could be classified into 3 groups according to their vaccine-elicited T-cell responses. One group of patients responded only to the modified peptide used for immunization, whereas another group of patients reacted to both the modified and native gp100 peptides, but not to naturally processed gp100 antigen on melanoma cells. In the third group of patients, circulating CD8 T cells recognized A2gp100 melanoma cell lines and also both the modified and native peptides. T cells with a low functional avidity, which were capable of lysing tumor cells only if tumor cells were first pulsed by the exogenous administration of native gp100(209-217) peptide were identified in most patients. These results indicate that vaccination with a modified gp100 peptide induced a heterogeneous group of gp100-specific T cells with a spectrum of functional avidities; however, high avidity, tumor-reactive T cells were detected in the majority of patients.

Recombinant erythropoietin in acute chemotherapy-induced anemia of children with cancer.

Chemotherapy-induced anemia in children with cancer is usually of acute onset. To investigate an alternate treatment to transfusion (Tx), we undertook a phase I-II clinical trial of daily administrations of recombinant erythropoietin (rHuEPO). Patients with a hemoglobin (Hgb) value < 75 g/l were treated for 14 days in cohorts of 3 at escalating daily doses of 25, 50, 70, 80, 90, and 100 U/kg respectively. The maximum-tolerated dose was not encountered. Of 18 courses given to 15 children aged 0.5-18 years, 7 (39%) were associated with increased or stable Hgb levels (courses without Tx), while 11 (61%) were terminated by a Tx, without evidence of a dose-response relationship. Changes in mean Hgb levels and absolute reticulocyte counts were paralleled by those of mean white blood cell, platelet, and absolute neutrophil counts during the first 7 days and when the end-points of the study were reached. Numbers of circulating burst-forming units-erythroid remained low throughout courses without Tx. No cumulative increase of serially determined serum EPO levels was observed and serum ferritin levels were elevated in both groups of courses. We conclude that daily administration of rHuEPO were safe but ineffective in our trial. Recovery of chemotherapy-induced myelosuppression appeared to be the rate-limiting factor for the outcome, without evidence of an enhanced stimulation of erythropoiesis. The lack of a proliferative response of specific progenitor cells suggested a mechanism of transient primary resistance to rHuEPO.

Loss of connexin40 is associated with decreased endothelium-dependent relaxations and eNOS levels in the mouse aorta.

Upon agonist stimulation, endothelial cells trigger smooth muscle relaxation through the release of relaxing factors such as nitric oxide (NO). Endothelial cells of mouse aorta are interconnected by gap junctions made of connexin40 (Cx40) and connexin37 (Cx37), allowing the exchange of signaling molecules to coordinate their activity. Wild-type (Cx40(+/+)) and hypertensive Cx40-deficient mice (Cx40(-/-)), which also exhibit a marked decrease of Cx37 in the endothelium, were used to investigate the link between the expression of endothelial connexins (Cx40 and Cx37) and endothelial nitric oxide synthase (eNOS) expression and function in the mouse aorta. With the use of isometric tension measurements in aortic rings precontracted with U-46619, a stable thromboxane A(2) mimetic, we first demonstrate that ACh- and ATP-induced endothelium-dependent relaxations solely depend on NO release in both Cx40(+/+) and Cx40(-/-) mice, but are markedly weaker in Cx40(-/-) mice. Consistently, both basal and ACh- or ATP-induced NO production were decreased in the aorta of Cx40(-/-) mice. Altered relaxations and NO release from aorta of Cx40(-/-) mice were associated with lower expression levels of eNOS in the aortic endothelium of Cx40(-/-) mice. Using immunoprecipitation and in situ ligation assay, we further demonstrate that eNOS, Cx40, and Cx37 tightly interact with each other at intercellular junctions in the aortic endothelium of Cx40(+/+) mice, suggesting that the absence of Cx40 in association with altered Cx37 levels in endothelial cells from Cx40(-/-) mice participate to the decreased levels of eNOS. Altogether, our data suggest that the endothelial connexins may participate in the control of eNOS expression levels and function.

Der Radioimmunoassay zur Ermittlung des carcinoembryonalen Antigens (CEA), seine Bedeutung und Limitierung während der postoperativen Kontrollperiode von Patienten mit colorectalem Carcino

Carcinoembryonic antigen (CEA) is a tumor marker defined by specific heterologous antisera. Elevated levels of circulating CEA can be detected by radioimmunoassay in most cases of colorectal carcinoma, depending on the degree of tumor spread. The fact that elevation of CEA level can also be observed in other types of carcinomas and in several nonmalignant conditions greatly limits the value of the CEA test for the early diagnosis of colorectal carcinomas. Repeated CEA measurements and their critical interpretation, however, appear to be of importance after tumor resection for the detection of tumor recurrence during the postoperative follow-up period.

Comparison of Some Molecular-genetic Techniques for Identification of Leishmania Circulating in Natural Foci of Zoonotic Cutaneous Leishmaniasis in the Central Asia Region

Different molecular-genetic methods were used to identify a cohort of Leishmania strains from natural foci of zoonotic cutaneous leishmaniasis located in Central Asia, on the former USSR territory. The results obtained using isoenzymes, PCR, restriction fragment length polymorphisms of kDNA and molecular hybridization techniques are discussed in terms of their applicability, discrimination power and feasibility for answering questions related to molecular epidemiological research and for detecting mixed Leishmania infections