Influence of human impacts on Albeluvisol analysed by X-ray microfluorescence: relative evolution of the transforming front at the tongue scale.

In this paper we studied the nature and hierarchy of the processes responsible for soil evolution as a function of land use (forest and culture). Albeluvisols were chosen as a pedological model for this study. Iron, manganese, calcium, potassium and trace elements were used as indicators of the soil processes. Their spatial distribution was mapped along tongues of Albeluvisols at a pluri-centimetric scale, using X-ray microfluorescence. In both land use, Fe distribution was shown to be closely related to the soil colour variation along the tongues. Nickel and Cu followed the same distribution. Zinc was almost functioning as Fe with the difference that this element was not lost from the transition zone identified between the bleached tongues and the ochre volumes representative of the illuvial horizon. Under forest, the Fe and Mn redox fronts were closely associated that allows mapping them on the same thin section. Manganese disappeared from the neighbourhood of the iron redox front under agriculture. This was interpreted as a slow down of the iron redox process due to pH increase while Mn redox process was not modified. In addition, under forest, Ca seems totally leached. Liming causes an increase of Ca concentrations in the whole soil profile. This Ca is in an exchangeable form principally located at the interface between white and ochre volumes. We concluded that by liming, Man induced drastic changes in the kinetic of redox process in Albeluvisols over 200 years showing at the same time the extreme rapidity of these processes.

Diagnostic accuracy of endoscopy in periradicular surgery - a comparison with scanning electron microscopy.

AIM: To compare the accuracy of endoscopic diagnostics with the scanning electron microscope (SEM) in evaluating elements of periradicular surgery. METHODOLOGY: The material consisted of 22 extracted human molars, which were subjected to the following treatments: orthograde root-canal obturation, root-end resection and root-end cavity preparation with diamond-coated sonic microtips. After each step, the cut root face was inspected with an endoscope, and subsequently, the roots were duplicated for SEM evaluation. Endoscope findings were compared to those obtained with SEM serving as the 'gold standard' with a blinded observer. The presence of the following structures was assessed including specificity and sensitivity: isthmuses, accessory canals, obturation gaps, microfractures and chipping of cavity margins. RESULTS: The specificity and sensitivity of the identification of isthmuses or accessory canals was 100% each for the endoscope compared to SEM. The sensitivity of identification of obturation gaps, crack formation or chipping ranged between 73 and 95% (except intradentine cracks with only 36% sensitivity). The specificity of the same parameters ranged between 77 and 100% for the endoscope compared to SEM. CONCLUSIONS: With the exception of intradentine cracks, the endoscope accurately identified microstructures following root-end resection and root-end preparation. The endoscope could be considered for use during intraoperative diagnostics in periradicular surgery.

Re-evaluating selective screening criteria for chlamydial infection among women in the U S Pacific Northwest.

OBJECTIVES: Screening women for Chlamydia trachomatis (CT) infection using selective screening criteria has been operational in the northwestern United States (Region X) since 1988. Changes in the field, including declines in CT prevalence, introduction of sensitive laboratory tests, and budgetary pressures necessitate reevaluating the selective screening approach to ensure program credibility and efficiency. GOALS: The goals of this study were to assess 1). performance of screening criteria in Region X, 2). predictors of CT infection, and 3). optimization of these criteria. STUDY DESIGN: We conducted cross-sectional analysis of 409882 CT test records of women from 1998 to 2000 using multivariate logistic regression and sensitivity and efficiency analyses. RESULTS: Young age (<25 yrs), cervical signs of infection, and recent exposure to or history of chlamydial infection were strongly associated with testing positive. Behavioral risks showed a weak association with infection. Currently used selective screening criteria were sensitive but not efficient. Criteria weighted toward young age, exposure to chlamydia, or cervicitis would increase criteria efficiency by nearly 25% in some settings while detecting >90% of infections. CONCLUSION: Evaluating selective screening criteria can result in modifications that could increase screening efficiency.

The use of a transyndesmotic bolt in the treatment of tibiofibular diastasis: two case studies.

The authors present a brief overview of tibiofibular diastasis and the mechanisms of injury associated with it. This type of injury is frequently misdiagnosed or improperly treated. Two case studies are presented with specific emphasis placed on the use of a transyndesmotic bolt in the reduction of the tibiofibular diastasis. The authors have found this to be more beneficial in the treatment of this condition, as opposed to the traditional use of a transmalleolar screw.

Effect of dietary phytic acid on zinc absorption in the healthy elderly, as assessed by serum concentration curve tests.

Zn absorption was investigated in healthy elderly subjects aged 71-78 years and in young subjects aged 23-43 years using serum concentration curve (SCC) tests. Both groups had similar Zn and protein status. The increase in serum Zn was monitored for 180 min after ingestion of 200 ml of soya milk enriched with 50 mg of Zn. Three levels of phytic acid were used: 0 g/200 ml (totally dephytinized soya milk), 0.13 g/200 ml (half dephytinized), and 0.26 g/200 ml (natural phytic acid content). In a first study the effect of 0 v. 0.26 g/200 ml phytic acid was compared in 10 elderly and 10 young subjects, each subject receiving both treatments. In a second study soya milks with 0 and 0.13 g/200 ml were tested in nine elderly and ten young subjects, again receiving both treatments. Mean areas under the curve of the SCC tests conducted with the 0 g/200 ml soya milk were found to be the same in both studies. Phytic acid strongly depressed Zn absorption in both studies (P < or = 0.05), but to a greater extent at the 0.26 g/200 ml level. No difference was found between the groups of young and elderly subjects. Therefore, no significant effect of aging on Zn absorption, as evaluated by the SCC test, or on the inhibitory effect of phytic acid was detected.