The sigma factor AlgU (AlgT) controls exopolysaccharide production and tolerance towards desiccation and osmotic stress in the biocontrol agent Pseudomonas fluorescens CHA0.

A variety of stress situations may affect the activity and survival of plant-beneficial pseudomonads added to soil to control root diseases. This study focused on the roles of the sigma factor AlgU (synonyms, AlgT, RpoE, and sigma(22)) and the anti-sigma factor MucA in stress adaptation of the biocontrol agent Pseudomonas fluorescens CHA0. The algU-mucA-mucB gene cluster of strain CHA0 was similar to that of the pathogens Pseudomonas aeruginosa and Pseudomonas syringae. Strain CHA0 is naturally nonmucoid, whereas a mucA deletion mutant or algU-overexpressing strains were highly mucoid due to exopolysaccharide overproduction. Mucoidy strictly depended on the global regulator GacA. An algU deletion mutant was significantly more sensitive to osmotic stress than the wild-type CHA0 strain and the mucA mutant were. Expression of an algU'-'lacZ reporter fusion was induced severalfold in the wild type and in the mucA mutant upon exposure to osmotic stress, whereas a lower, noninducible level of expression was observed in the algU mutant. Overexpression of algU did not enhance tolerance towards osmotic stress. AlgU was found to be essential for tolerance of P. fluorescens towards desiccation stress in a sterile vermiculite-sand mixture and in a natural sandy loam soil. The size of the population of the algU mutant declined much more rapidly than the size of the wild-type population at soil water contents below 5%. In contrast to its role in pathogenic pseudomonads, AlgU did not contribute to tolerance of P. fluorescens towards oxidative and heat stress. In conclusion, AlgU is a crucial determinant in the adaptation of P. fluorescens to dry conditions and hyperosmolarity, two major stress factors that limit bacterial survival in the environment.

Vacuum assisted venous drainage does not increase trauma to blood cells.

Although gravity drainage has been the standard technique for cardiopulmonary bypass (CPB), the development of min imally invasive techniques for cardiac surgery has renewed interest in using vacuum assisted venous drainage (VAVD) Dideco (Mirandola, Italy) has modified the D903 Avant oxygenator to apply a vacuum to its venous reservoir. The impact of VAVD on blood damage with this device is analyzed. Six calves (mean body weight, 71.3 +/- 4.1 kg) were con nected to CPB by jugular venous and carotid arterial cannu lation, with a flow rate of 4-4.51 L/min for 6 h. They were assigned to gravity drainage (standard D903 Avant oxygen ator, n = 3) or VAVD (modified D903 Avant oxygenator, n = 3). The animals were allowed to survive for 7 days. A standard battery of blood samples was taken before bypass, throughout bypass, and 24 h, 48 h, and 7 days after bypass. Analysis of variance was used for repeated measurements. Thrombocyte and white blood cell counts, corrected by hematocrit and normalized by prebypass values, were not significantly different between groups throughout all study periods. The same holds true for hemolytic parameters (lactate dehydrogenase [LDH] and plasma hemoglobin). Both peaked at 24 hr in the standard and VAVD groups: LDH, 2,845 +/- 974 IU/L vs. 2,537 +/- 476 IU/L (p = 0.65), respectively; and plasma hemoglobin, 115 +/- 31 mg/L vs. 89 +/- 455 mg/L (p = 0.45), respectively. In this experimental setup with prolonged perfusion time, VAVD does not increase trauma to blood cells in comparison with standard gravity drainage.

Absence of ectopic epithelial inclusions in 3,904 axillary lymph nodes examined in sentinel technique.

Intraoperative examination of sentinel axillary lymph nodes can be done by imprint cytology, frozen section, or, most recently, by PCR-based amplification of a cytokeratin signal. Using this technique, benign epithelial inclusions, representing mammary tissue displaced along the milk line, will likely generate a positive PCR signal and lead to a false-positive diagnosis of metastatic disease. To better appreciate the incidence of ectopic epithelial inclusions in axillary lymph nodes, we have performed an autopsy study, examining on 100 μm step sections 3,904 lymph nodes obtained from 160 axillary dissections in 80 patients. The median number of lymph nodes per axilla was 23 (15, 6, and 1 in levels 1, 2, and 3, respectively). A total of 30,450 hematoxylin-eosin stained slides were examined, as well as 8,825 slides immunostained with pan-cytokeratin antibodies. Despite this meticulous work-up, not a single epithelial inclusion was found in this study, suggesting that the incidence of such inclusions is much lower than the assumed 5% reported in the literature.

Three-dimensional patient-specific dosimetry in radioimmunotherapy with 90Y-ibritumomab-tiuxetan.

Aim of the present article was to perform three-dimensional (3D) single photon emission tomography-based dosimetry in radioimmunotherapy (RIT) with (90)Y-ibritumomab-tiuxetan. A custom MATLAB-based code was used to elaborate 3D images and to compare average 3D doses to lesions and to organs at risk (OARs) with those obtained with planar (2D) dosimetry. Our 3D dosimetry procedure was validated through preliminary phantom studies using a body phantom consisting of a lung insert and six spheres with various sizes. In phantom study, the accuracy of dose determination of our imaging protocol decreased when the object volume decreased below 5 mL, approximately. The poorest results were obtained for the 2.58 mL and 1.30 mL spheres where the dose error evaluated on corrected images with regard to the theoretical dose value was -12.97% and -18.69%, respectively. Our 3D dosimetry protocol was subsequently applied on four patients before RIT with (90)Y-ibritumomab-tiuxetan for a total of 5 lesions and 4 OARs (2 livers, 2 spleens). In patient study, without the implementation of volume recovery technique, tumor absorbed doses calculated with the voxel-based approach were systematically lower than those calculated with the planar protocol, with average underestimation of -39% (range from -13.1% to -62.7%). After volume recovery, dose differences reduce significantly, with average deviation of -14.2% (range from -38.7.4% to +3.4%, 1 overestimation, 4 underestimations). Organ dosimetry in one case overestimated, in the other underestimated the dose delivered to liver and spleen. However, both for 2D and 3D approach, absorbed doses to organs per unit administered activity are comparable with most recent literature findings.

Single-metal deposition: optimization of this fingermark enhancement technique

Following the introduction of single-metal deposition (SMD), a simplified fingermark detection technique based on multimetal deposition, optimization studies were conducted. The different parameters of the original formula were tested and the results were evaluated based on the contrast and overall aspect of the enhanced fingermarks. The new formula for SMD was found based on the most optimized parameters. Interestingly, it was found that important variations from the base parameters did not significantly affect the outcome of the enhancement, thus demonstrating that SMD is a very robust technique. Finally, a comparison of the optimized SMD with multi-metal deposition (MMD) was carried out on different surfaces. It was demonstrated that SMD produces comparable results to MMD, thus validating the technique.

Multi-phase postmortem CT angiography: recognizing technique-related artefacts and pitfalls.

BACKGROUND AND PURPOSE: Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. MATERIAL AND METHODS: An experienced radiologist blinded to all clinical and forensic data retrospectively reviewed 49 MPMCTAs. Each angiographic phase, i.e. arterial, venous and dynamic, was analysed separately to identify phase-specific artefacts based on location and aspect. RESULTS: Incomplete contrast filling of the cerebral venous system was the most commonly encountered artefact, followed by contrast agent layering in the lumen of the thoracic aorta. Enhancement or so-called oedematization of the digestive system mucosa was also frequently observed. CONCLUSION: All MPMCTA artefacts observed and described here are reproducible and easily identifiable. Knowledge about these artefacts is important to avoid misinterpreting them as pathological findings.

Bénéfices de l'utilisation de la clozapine en première intention chez de jeunes patients schizophrènes : quelques données à propos de six patients.

Résumé : La clozapine (Leponex®) est un neuroleptique atypique utilisé depuis une quarantaine d'années (synthétisée en 1959) dans le traitement de la schizophrénie résistante. Son utilisation a fait l'objet de controverses importantes en raison de son profil d'effets secondaires, potentiellement fatals (agranulocytose), et a entraîné son retrait de certains pays pendant de nombreuses années, malgré certaines caractéristiques qui en font une molécule très intéressante sur le plan clinique. On peut citer à cet égard une efficacité antipsychotique importante tant sur les symptômes positifs que sur les symptômes négatifs de la maladie, ainsi que l'absence d'effets secondaires extrapyramidaux, tels que ceux entraînés par les neuroleptiques classiques. Depuis la réadmission de la clozapine par la FDA aux Etats-Unis en 1990, suite notamment aux travaux montrant l'amélioration, grâce à cette molécule, des dyskinésies tardives induites par les neuroleptiques classiques, on assiste à un regain d'intérêt marqué pour ses possibilités thérapeutiques. L'indication reste toutefois limitée à l'heure actuelle au traitement de la schizophrénie résistante à d'autres neuroleptiques, donc un traitement en deuxième intention. Sachant que l'évolution de la schizophrénie est influencée, entre autres facteurs, par la durée des manifestations symptomatiques, il nous a semblé intéressant d'évaluer le devenir de jeunes patients schizophrènes mis d'emblée au bénéfice d'un traitement par la clozapine. C'est le sujet de la présente étude. Cette étude a été initialement conçue comme une étude de cohorte, randomisée, en double aveugle, multi-site à l'échelle romande, avec un suivi des patients sur une année. Les difficultés rencontrées, qui ont abouti à une interruption précoce ne permettant le relevé que des observations de six patients, sont détaillées. Après une brève introduction sur la schizophrénie et sur la clozapine, ce travail décrit l'historique de l'étude, ses buts et sa méthodologie. Suit une description des six patients et leur évolution au cours de l'étude. Dans le chapitre IV, les résultats sont analysés et discutés dans une perspective descriptive. Précédant la bibliographie et les annexes, la conclusion fournit l'opportunité de discuter les apports et les limites de ce travail, en le resituant dans le contexte international actuel de regain d'intérêt pour l'utilisation de la clozapine dans le traitement de la schizophrénie.

Resting metabolic rate in six- to ten-year-old obese and nonobese children.

The resting metabolic rate (RMR) and body composition of 130 obese and nonobese prepubertal children, aged 6 to 10 years, were assessed by indirect calorimetry and skin-fold thickness, respectively. The mean (+/- SD) RMR was 4619 +/- 449 kJ.day-1 (164 +/- 31 kJ.kg body weight-1 x day-1) in the 62 boys and 4449 +/- 520 kJ.day-1 (147 +/- 32 kJ.kg body weight-1 x day-1) in the 68 girls. Fat-free mass was the best single predictor of RMR (R2 = 0.64; p < 0.001). Step-down multiple regression analysis, with independent variables such as age, gender, weight, and height, allowed several RMR predictive equations to be developed. An equation for boys is as follows: RMR (kJ.day-1) = 1287 + 28.6 x Weight(kg) + 23.6 x Height(cm) - 69.1 x Age(yr) (R2 = 0.58; p < 0.001). An equation for girls is as follows: RMR (kJ.day-1 = 1552 + 35.8 x Weight (kg) + 15.6 x Height (cm) - 36.3 x Age (yr) (R2 = 0.69; p < 0.001). Comparison between the measured RMR and that predicted by currently used formulas showed that most of these equations tended to overestimate the RMR of both genders, especially in overweight children.

Laparoscopic inguinal hernia repair with extraperitoneal double-mesh technique.

Totally extraperitoneal laparoscopic hernia repair is an efficient but technically demanding procedure. As mechanisms of hernia recurrence may be related to these technical difficulties, we have modified a previously described double-mesh technique in an effort to simplify the procedure. Extraperitoneal laparoscopic hernia repairs were performed in 82 male and 17 female patients having inguinal, femoral, and recurrent bilateral hernias. A standard propylene mesh measuring 15 x 15 cm was cut into two pieces of 4 x 15 cm and 11 x 15 cm. The smaller mesh was placed over both inguinal rings without splitting. The larger mesh was then inserted over the first mesh and stapled to low-risk zones, reinforcing the large-vessel area and the nerve transition zone. The mean procedure duration was 60 minutes for unilateral and 100 minutes for bilateral hernia repair. Patients were discharged from the hospital within 48 hours. The mean postoperative follow-up was 22 months, with no recurrences, neuralgia, or bleeding complications. Over a 2-year period, this technique was found to be satisfactory without recurrences or significant complications. In our hands, this technique was easier to perform: it allows for a less than perfect positioning of the meshes and avoids most of the stapling to crucial zones.

Low-pressure environment and remodelling of the forearm vein in Brescia-Cimino haemodialysis access.

BACKGROUND: The aim of the study was to determine which, and to what extent, haemodynamic parameters contribute to the remodelling of the venous limb of the Brescia-Cimino haemodialysis access. METHODS: The dimensions of the radial artery and the venous limb of the haemodialysis access were measured by an echo-tracking technique. In six ESRD patients undergoing primary arteriovenous fistula (AVF) formation, vessel diameter, wall thickness, blood pressure and blood flow were measured after the operation, and at 1 and 3 months follow-up. The contralateral forearm vessels in their native position served as baseline values for comparison. RESULTS: The diameter of the proximal antecubital vein progressively increased over the study period without reaching significant differences (4430, 5041 and 6620 microm at weeks 1, 4 and 12 respectively), whereas the intima-media thickness remained unchanged. The venous dilatation was associated with a reduction of the mean shear stress that culminated after the operation and progressively returned to normal venous values at 3 months (24.5 vs 10.4 dyne/cm(2), P<0.043). Thus the venous limb of the AVF undergoes eccentric hypertrophy as demonstrated by the increase in wall cross-sectional area (4.42 vs 6.32 mm(2) at week 1 vs week 12, P<0.028). At the time of the operation, the blood pressure in the AVF was 151+/-14/92.4+/-11 mmHg vs 49+/-19/24.5+/-6 mmHg (means+/-SEM) for the radial artery and the venous limb of the vascular access, respectively. One year after the operation the blood pressure in the venous limb had not changed: 42+/-14/25.3+/-7 mmHg (means+/-SEM). Under these conditions, the systolo-diastolic diameter changes observed in the radial artery and the antecubital vein were within a similar range at all time points: 56+/-17 vs 90+/-26 microm (means+/-SEM) at week 12. CONCLUSIONS: The increased circumferential stress resulting from the flow-mediated dilatation rather than the elevation of blood pressure appears to represent the main contributing factor to the eccentric hypertrophy of the venous limb of Brescia-Cimino haemodialysis access.

Reconstructing mid-to-recent Holocene paleoenvironments in the vicinity of ancient Amarynthos (Euboea, Greece).

This article examines the shoreline evolution and human occupation in the vicinity of the important archeological site of Amarynthos (Euboea Island, Greece) over the last six millennia. Archeological evidence indicates a continuous occupation of the site from the Bronze Age to the Roman period and the site is well-known, thanks to the existence of a sanctuary dedicated to the goddess Artemis. Based on the study of four boreholes, a paleogeographic reconstruction of the coastal landscape is proposed. Facies were determined based on mollusc identification, and sedimentology based on grain-size measurements (hand sieving for the fraction above 2 mm and LASER technique for particles below 2 mm) and loss-on-ignition. In addition, a series of 12 AMS radiocarbon dates define a reliable chronostratigraphy. Results suggest the presence of a fully marine environment from the early Holocene to ca. 2600-2400 cal. BC, which developed into a brackish environment from ca. 2600-2400 cal. BC to ca. 750 cal. BC due to the deltaic progradation of the nearby stream (Sarandapotamos River). From ca. 750 cal. BC onward, coastal swamps prevailed in the study area. Human-environmental interaction is discussed and particular attention is paid to the paleolandscape configuration of Amarynthos.

Quantitative monitoring of tamoxifen in human plasma extended to 40 metabolites using liquid-chromatography high-resolution mass spectrometry: new investigation capabilities for clinical pharmacology.

Liquid-chromatography (LC) high-resolution (HR) mass spectrometry (MS) analysis can record HR full scans, a technique of detection that shows comparable selectivity and sensitivity to ion transitions (SRM) performed with triple-quadrupole (TQ)-MS but that allows de facto determination of "all" ions including drug metabolites. This could be of potential utility in in vivo drug metabolism and pharmacovigilance studies in order to have a more comprehensive insight in drug biotransformation profile differences in patients. This simultaneous quantitative and qualitative (Quan/Qual) approach has been tested with 20 patients chronically treated with tamoxifen (TAM). The absolute quantification of TAM and three metabolites in plasma was realized using HR- and TQ-MS and compared. The same LC-HR-MS analysis allowed the identification and relative quantification of 37 additional TAM metabolites. A number of new metabolites were detected in patients' plasma including metabolites identified as didemethyl-trihydroxy-TAM-glucoside and didemethyl-tetrahydroxy-TAM-glucoside conjugates corresponding to TAM with six and seven biotransformation steps, respectively. Multivariate analysis allowed relevant patterns of metabolites and ratios to be associated with TAM administration and CYP2D6 genotype. Two hydroxylated metabolites, α-OH-TAM and 4'-OH-TAM, were newly identified as putative CYP2D6 substrates. The relative quantification was precise (<20 %), and the semiquantitative estimation suggests that metabolite levels are non-negligible. Metabolites could play an important role in drug toxicity, but their impact on drug-related side effects has been partially neglected due to the tremendous effort needed with previous MS technologies. Using present HR-MS, this situation should evolve with the straightforward determination of drug metabolites, enlarging the possibilities in studying inter- and intra-patients drug metabolism variability and related effects.