[Influence of clinical and pathological factors on lymph node harvesting in surgical specimens of colorectal cancer]. / Facteurs anatomo-cliniques influençant la collecte ganglionnaire dans les pièces de résection chirurgicale pour cancer colorectal.

In colorectal cancer staging, pathologic lymph node analysis is a crucial information for the clinician and must be performed with a maximal level of accuracy. Therefore, the surgical sample analysis needs harvesting of as many lymph nodes as possible from the mesentery. In this study, we analysed the influence of a series of clinical and pathological factors which could influence lymph node harvesting. A total of 239 patients were included in our study. The factors with a statistically significant influence on lymph node collection (pinferior to0.05) were the age, gender of the patient, size of the primitive neoplasm, size of the surgical specimen, expertise of the surgeon and the pathology department. The presence of a radiochimiotherapy did not have any influence on the lymph node collection. This study highlights the importance of lymph node harvesting in colorectal surgical specimens of colo-rectal cancers.

Dans la stadification de l'adénocarcinome colorectal, le statut ganglionnaire anatomopathologique constitue une information capitale pour le clinicien et doit être défini avec un maximum d'exactitude. L'analyse de la pièce de résection chirurgicale requiert la collecte au sein du méso du plus grand nombre possible de ganglions lymphatiques. Dans cette étude, nous avons analysé une série de facteurs anatomo-cliniques pouvant influencer la collecte ganglionnaire. Un total de 239 patients a été inclus dans notre étude. Les facteurs avec une influence statistiquement significative sur la collecte ganglionnaire (p inf�rieur a 0,05) ont été l'âge et le sexe du patient, la taille de la tumeur primitive, la taille de la pièce d'exérèse, le degré d'activité du chirurgien et le laboratoire d'anatomie pathologique. La présence ou non d'une radiochimiothérapie néo-adjuvante n'a pas eu d'impact sur le nombre de ganglions prélevés. Cette étude souligne l'importance de la collecte ganglionnaire au sein des pièces de résection chirurgicale d'un cancer colo-rectal.

Comparison of ActiGraph GT3X+ and Actical accelerometer data in 9-11-year-old Canadian children.

Accelerometry is the gold standard for field-based physical activity assessment in children; however, the plethora of devices, data reduction procedures, and cut-points available limits comparability between studies. This study aimed to compare physical activity variables from the ActiGraph GT3X+ and Actical accelerometers in children under free-living conditions. A cross-sectional study of 379 children aged 9-11 years from Ottawa (Canada) was conducted. Children wore the ActiGraph GT3X+ and Actical accelerometers on the hip simultaneously for 7 consecutive days (24-h protocol). Moderate-to-vigorous (MVPA), vigorous (VPA), moderate (MPA), and light (LPA) physical activity, as well as sedentary time, (SED) were derived using established data reduction protocols. Excellent agreement between devices was observed for MVPA (ICC = 0.73-0.80), with fair to good agreement for MPA, LPA and SED, and poor agreement for VPA. Bland-Altman plots showed excellent agreement for MVPA, LPA, and SED, adequate agreement for MPA, and poor agreement for VPA. MVPA derived from the Actical was 11.7% lower than the ActiGraph GT3X+. The ActiGraph GT3X+ and Actical are comparable for measuring children's MVPA. However, comparison between devices for VPA, MPA, LPA, and SED are highly dependent on data reduction procedures and cut-points, and should be interpreted with caution.

Brain lateralization probed by water diffusion at the atomic to micrometric scale.

Combined neutron scattering and diffusion nuclear magnetic resonance experiments have been used to reveal significant interregional asymmetries (lateralization) in bovine brain hemispheres in terms of myelin arrangement and water dynamics at micron to atomic scales. Thicker myelin sheaths were found in the left hemisphere using neutron diffraction. 4.7 T dMRI and quasi-elastic neutron experiments highlighted significant differences in the properties of water dynamics in the two hemispheres. The results were interpreted in terms of hemisphere-dependent cellular composition (number of neurons, cell distribution, etc.) as well as specificity of neurological functions (such as preferential networking).

Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation.

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

New irradiation geometry for microbeam radiation therapy.

Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays.

Effects of ketanserin on lipids, lipoproteins, and plasma atrial natriuretic factor in patients with essential hypertension.

The effects of ketanserin, 40 mg/day (KE40) and 80 mg/day (KE80) on mean arterial pressure, lipids, lipoproteins, and circulating atrial natriuretic factor (ANF) were investigated in a 24-week controlled study in 29 patients suffering from mild to moderate hypertension. A significant decrease in mean arterial pressure (MAP) was observed after 18 weeks of therapy, accompanied by a 64% (P less than .05) and 80% (P less than .02) increase in circulating ANF levels with KE40 and KE80, respectively. There were no significant changes in mean total cholesterol, triglycerides, or cholesterol of the high density lipoproteins (HDL), low density lipoproteins (LDL), and very low density lipoproteins (VLDL) fractions. There was a significant increase in the mean apo B levels and consequently a slight but statistically significant decrease in the ratio of LDL C/B. It is concluded that both doses of KE are effective for monotherapy of mild to moderate essential hypertension. The drug sharply increases circulating ANF levels without significantly altering the plasma lipids. In contrast, by increasing the apolipoprotein B content of the LDL fraction, the beneficial cardiovascular effect of a lowered blood pressure may be partly blunted.

[Study of interventricular septal defects with equal aortic and pulmonary artery pressures. Classification by clinical and computer methods of 70 cases]. / Etude des communications interventriculaires avec égalité de pression aortique et artérielle pulmonaire. Classification par méthode clinique et informatique de 70 observations

Application of various methods of classification to a group of 70 cases of ventricular septal defect with high pulmonary artery hypertension allowed a comparative study between the various methods aiming at distinguishing the forms with low from high pulmonary artery resistance. The reference clinical classification provides supplementary informations derived from the natural or post-operative course and eventually from the microscopic examination. The first automatic classification relies on the study of a single criterion: the pulmonary arteriolar resistance and the systemic resistance ratio. A second classification is based on the attribution of points to some clinical or haemodynamic signs resulting in a score orienting the classification of every individual. Multifactorial analysis methods deal with all the available informations for the overall group, and suppose the use of a computer. The informatic methods make it possible to study the classifying value of every sign. Correlations were established between these various techniques and the medical classification.

Objectively measured physical activity, sedentary time and sleep duration: independent and combined associations with adiposity in canadian children.

OBJECTIVE: To examine independent and combined associations among objectively measured movement/non-movement behaviors (moderate-to-vigorous-intensity physical activity (MVPA), total sedentary time and sleep duration) and adiposity indicators in a sample of Canadian children. METHODS: A cross-sectional study was conducted on 507 children aged 9-11 years from Ottawa, Canada. Movement/non-movement behaviors were assessed using an Actigraph GT3X+ accelerometer over 7 days (24-h protocol). Outcomes included percentage body fat (bioelectrical impedance) and waist-to-height ratio. RESULTS: After adjustment for age, sex, ethnicity, maturity offset, fast food consumption, annual household income and highest level of parental education, MVPA was inversely and sedentary time positively associated with adiposity indicators, whereas sleep duration was not. However, only MVPA remained significantly associated with adiposity indicators after additional adjustment for the other movement/non-movement behaviors. Combined associations using tertiles of the three movement/non-movement behaviors showed that higher levels of MVPA were associated with lower adiposity indicators, irrespective of total sedentary time and sleep duration. CONCLUSIONS: Higher levels of MVPA were associated with lower adiposity in this sample of children regardless of sedentary time and sleep duration. Although correlational in nature, these findings suggest that future efforts of obesity reduction should focus more on increasing MVPA than on reducing sedentary time or increasing sleep duration to maximize the effectiveness of interventions.

Effects of metoprolol and propranolol on lipid metabolism.

Treatment of five hypertriglyceridemic and one normolipemic patients with propranolol, a non-selective beta-blocking agent, and metoprolol, which is generally considered to be a cardioselective beta-adrenoceptor antagonist, was observed to produce a further elevation in their triglyceride levels. The subjects were followed for 20 weeks, during which they received propranolol for eight weeks, a placebo for four weeks and metoprolol for eight weeks in a crossover design. The analysis suggested that the increase in triglyceride levels was less pronounced with the more cardioselective agent. Moreover, alpha-cholesterol decreased significantly after propranolol but remained constant while on metoprolol. Both drugs decreased beta-cholesterol whereas chylo- and pre- beta-cholesterol increased, particularly with propranolol. Considering the contradictory evidence regarding the clinical importance of chronic elevation of plasma triglyceride and decreased alpha- und beta-cholesterol concentrations, it is suggested that a cardioselective drug would be presently preferable in hyperlipidemic subjects.

Chronic cyanide poisoning of rainbow trout and its effects on growth, respiration, and liver histopathology.

Cyanide markedly affected growth and resting metabolic rate while causing degenerative hepatic necrosis in juvenile rainbow trout (Salmo gairdneri, Richardson). This was revealed during two experiments performed in continuously renewed water at 12.5 degree C with fish fed a restricted artificial diet and exposed to assayed cyanide concentrations of 0.00, 0.01, 0.02, or 0.03 mg/L hydrogen cyanide (HCN) for 18 days. At 0.02 and 0.03 mg/L, HCN growth was reduced by 40 to 95% after 18 days. At all concentrations, cyanide caused a severe initial repression of specific growth rate, followed by a highly significant increase which was insufficient to compensate for the original repression. Previous exposure to cyanide promoted a higher resting metabolic rate during the six days following exposure, the effect increasing with cyanide concentration. At all concentrations tested, widespread cyanide-induced degenerative necrosis of hepatocytes was observed; it was more intense at higher cyanide concentrations and well established even at 0.01 mg/L HCN.

Gene order comparisons for phylogenetic inference: evolution of the mitochondrial genome.

Detailed knowledge of gene maps or even complete nucleotide sequences for small genomes leads to the feasibility of evolutionary inference based on the macrostructure of entire genomes, rather than on the traditional comparison of homologous versions of a single gene in different organisms. The mathematical modeling of evolution at the genomic level, however, and the associated inferential apparatus are qualitatively different from the usual sequence comparison theory developed to study evolution at the level of individual gene sequences. We describe the construction of a database of 16 mitochondrial gene orders from fungi and other eukaryotes by using complete or nearly complete genomic sequences; propose a measure of gene order rearrangement based on the minimal set of chromosomal inversions, transpositions, insertions, and deletions necessary to convert the order in one genome to that of the other; report on algorithm design and the development of the DERANGE software for the calculation of this measure; and present the results of analyzing the mitochondrial data with the aid of this tool.

Effects of chlorthalidone and metoprolol alone or in combination (logroton) on blood pressure, lipids, lipoproteins and circulating plasma ANF levels in essential hypertension.

The effects of chlorthalidone (mean dose 25 mg/day), metoprolol (mean dose 200 mg/day) or their combination (logroton) on blood pressure, lipids, lipoproteins and circulating atrial natriuretic factor (ANF) were evaluated in a controlled trial of 42-week duration in 33 hypertensive patients. There was a significant reduction in mean arterial pressure after chlorthalidone and metoprolol treatments. This effect was more pronounced with the chlorthalidone/metoprolol combination (logroton). There were no significant changes in mean ANF levels after any drug regimen, although a tendency to increase was observed after six weeks of treatment with metoprolol. Both chlorthalidone and metoprolol as monotherapy increased the total triglycerides. This effect was less pronounced with logroton. During metoprolol treatment, HDL cholesterol decreased significantly, whereas VLDL-C increased. When combined drug therapy was administered, the unfavorable effects on HDL-C were partially blunted and VLDL-C returned to baseline. LDL-cholesterol did not change significantly during any drug regimen nor did the ratio of LDL-C/HDL-C. Logroton significantly increased the VLDL apo B levels in patients who had received chlorthalidone as monotherapy but had no effect in patients already treated with metoprolol. Neither treatment had a significant influence on the ratio of LDL-C/B. There were no serious adverse events reported throughout the study. It is concluded that logroton may be an effective combination therapy that produces less adverse effects on lipid and lipoprotein metabolism than chlorthalidone or metoprolol monotherapies.

Screening programs for hypertension.

MAJOR SCREENING PROGRAMS FOR HYPERTENSION ARE NECESSARY FOR THE FOLLOWING REASONS: (a) the 12 to 15% prevalence of hypertension in the North American population; (b) the high proportion of hypertensive patients who are inadequately treated or whose disease is not even recognized; (c) the fact that in too many medical centres hypertension is poorly investigated or considered an insignificant finding; (d) the demonstration by many groups, especially the Framingham study, of hypertension as the major factor in the occurrence of severe cardiovascular disease; and (e) the achievement of a marked decrease in severe cardiovascular complications following adequate treatment. But such screening programs are of little value if unaccompanied by a major educational effort directed not only to the public but also to the medical profession, and a parallel increase in the funding of biomedical research into the basic physiopathological mechanisms of hypertension.

Leisure physical activity is associated with quantitative ultrasound measurements independently of bone mineral density in postmenopausal women.

The purpose of this study was to assess the magnitude of the relationship between leisure physical activity and bone status as measured either by an Achilles ultrasound bone densitometer (QUS) or dual-energy X-ray absorptiometry (DXA) in postmenopausal women. We studied 1162 French Canadian postmenopausal women, aged 33-84 years (mean age 58 years), for QUS parameters [broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI)] measured at the right calcaneus, and bone mineral density (BMD) measured at the lumbar spine and femoral neck. Multivariate regression analyses revealed that leisure physical activity level was an independent predictor of the heel QUS parameters and of femoral neck BMD. No such association was observed for BMD of the lumbar spine. Heel QUS parameters (BUA, SOS, SI) and femoral neck BMD adjusted for interfering covariables showed a statistically significant difference between sedentary (less than three sessions/month) and active women (three or more sessions/week) (P < or = 0.001). Furthermore, after adjusting each heel QUS parameters for the mean lumbar spine BMD value, the association observed between leisure physical activity and QUS remained significant. These results suggest that regular leisure physical activity could influence QUS parameters, independently of BMD, and that quantitative ultrasound could be a suitable outcome measure in exercise studies in postmenopausal women.