Fatal outcome of posterior reversible encephalopathy syndrome (PRES) in a lupus nephropathy patient: A case report

Posterior reversible encephalopathy syndrome is a rare underestimated condition, that generally complicates a rise in blood pressure in an acute setting. This entity has been increasingly identified in patients with systemic lupus erythematosus disease. PRES is challenging to diagnose seeing as it presents with nonspecific neurological symptoms, such as head-aches, confusion, seizures, visual changes or a coma, and can mimic neuropsychiatric lupus. Imaging plays a necessary role in confirming this diagnosis, as it is characterized by vasogenic edema of the posterior white matter, in which the distribution is bilateral and symmetrical. Although this syndrome is rare, early diagnosis allows a prompt treatment and therefore a favorable outcome. We present a case report of PRES in a 14-year-old female previously diagnosed with lupus nephropathy, who presented to the emergency department with seizures and uncontrolled hypertension, that was unfortunately not reversible is this patient.     

Unsteady magnetohydrodynamic blood flow through irregular multi-stenosed arteries

Flow of an electrically conducting fluid characterizing blood through the arteries having irregular shaped multi-stenoses in the environment of a uniform transverse magnetic-field is analysed. The flow is considered to be axisymmetric with an outline of the irregular stenoses obtained from a three-dimensional casting of a mild stenosed artery, so that the physical problem becomes more realistic from the physiological point of view. The marker and cell (MAC) and successive-over-relaxation (SOR) methods are respectively used to solve the governing unsteady magnetohydrodynamic (MHD) equations and pressure-Poisson equation quantitatively and to observe the flow separation. The results obtained show that the flow separates mostly towards the downstream of the multi-stenoses. However, the flow separation region keeps on shrinking with the increasing intensity of the magnetic-field which completely disappears with sufficiently large value of the Hartmann number. The present observations certainly have some clinical implications relating to magnetotherapy which help reducing the complex flow separation zones causing flow disorder leading to the formation and progression of the arterial diseases.     

The sleep of Africans and Europeans in the Ivory Coast: questionnaire study

Sleep behaviour has been extensively studied with questionnaires in industrialised countries to investigate the epidemiology of sleep-wake disorders. However, only few attempts have yet been made to examine sleep behaviour of people living in Africa. Although, a large number of studies in hot or cold environments have used short-term exposures, reporting disrupted sleep for most of them, long-term exposures to stressful thermal environments are rare in the literature. Prior to the present investigation, we used questionnaires to analyse the effects of seasonal heat increase on perceived sleep behaviour and sleep quality in young native African students in Niger [7], even though these methods of investigation are by no means as accurate as polysomnographic recordings. The hypothesis was that sleep behaviour may be influenced by climatic variations in a hot dry tropical climate. Such climatic variations have been shown to induce seasonal heat acclimatisation marked by changes in body temperature rhythms in the hot versus the cool season [13]. Sleep behaviour was examined during two 7-day periods in January ("cool-dry" season, 88 subjects) and May ("hot-dry" season, 53 subjects). The questionnaire was completed after night sleep and/or naps. The subjects slept an average of 7 1/2 hours a day, most of them having afternoon naps. They experienced no major seasonal variation in their sleep behaviour, but for an increased number of awakenings during the hot season. Restorative quality of sleep scored lower after a nap than after nocturnal sleep. Therefore, general sleep characteristics were not modified by seasonal temperature variations in African native students, perhaps because of the limited changes in daylight under the low latitude of Niamey. Another investigation was carried out using the same 12-item questionnaire in Abidjan on 78 medical students who did not have a nap [9]. Contrary to the Niamey students, the Abidjan subjects adopted short duration sleep schedules, without any effect on the subjective quality of the restorative properties of their sleep.     

Lytic versus stimulatory synapse in cytotoxic T lymphocyte/target cell interaction: manifestation of a dual activation threshold

Activation of biological functions in T lymphocytes is determined by the molecular dynamics occurring at the T cell/opposing cell interface. In the present study, a central question of cytotoxic T lymphocyte (CTL) biology was studied at the single-cell level: can two distinct activation thresholds for cytotoxicity and cytokine production be explained by intercellular molecular dynamics between CTLs and targets? In this study, we combine morphological approaches with numerical analysis, which allows us to associate specific patterns of calcium mobilization with different biological responses. We show that CTLs selectively activated to cytotoxicity lack a mature immunological synapse while exhibiting a low threshold polarized secretion of lytic granules and spike-like patterns of calcium mobilization. This finding is contrasted by fully activated CTLs, which exhibit a mature immunological synapse and smooth and sustained calcium mobilization. Our results indicate that intercellular molecular dynamics and signaling characteristics allow the definition of two activation thresholds in individual CTLs: one for polarized granule secretion (lytic synapse formation) and the other for cytokine production (stimulatory synapse formation).     

Flexor tendon repair using shape memory alloy suture: a biomechanical evaluation

The purpose of the current study was to test in vitro a new shape memory alloy suture for flexor tendon repair. Forty fresh-frozen human anatomic flexor superficialis and profundus tendons were divided and repaired via the cruciate four-strand technique using one of two suture materials (the shape memory alloy suture and the 4-0 Ethibond suture). The forces required to cause a 1, 2, and 3 mm gap, ultimate load to failure, and repair stiffness were compared. Twenty specimens of each suture material also were tensile tested for load to failure, tensile strength, and elongation at failure. The shape memory alloy suture had a significantly higher mean resistance force to 1, 2, and 3 mm gap formation than the 4-0 Ethibond suture (47 N versus 31 N, 51 N versus 36 N, and 57 N versus 41 N, respectively). The shape memory alloy suture repair was 40% stronger than the 4-0 Ethibond suture (61.9 +/- 8.8 N versus 44.3 +/- 10.6 N). Repair with the shape memory alloy suture was significantly stiffer than repair with the 4-0 Ethibond suture (8.1 +/- 1.0 N/mm versus 6.1 +/- 0.9 N/mm). The load to failure and tensile strength of the shape memory alloy suture were significantly higher than that of the 4-0 Ethibond suture. The values of elongation for the two materials were not significantly different. The results of the current study suggest that the shape memory alloy suture may be superior to the 4-0 Ethibond suture in resisting gap formation in the range of forces generated in the early rehabilitation protocol and may be the future material of choice for tendon repairs.     

Evaluation of the viability and validity of an instrument to measure community activation

OBJECTIVE: This study examines psychometric properties of a community activation assessment scale used for the evaluation of the Quebec project within the Federal Provincial Heart Health Initiative. The scale is composed of three sub scales, one for each of the intervention target risk factors. METHODS: Data were collected by telephone interviews conducted with 199 key informants from the 24 communities of the project. Reliability was studied using Cronbach's alpha coefficients and intraclass correlations. Validity was explored with factor analysis techniques. RESULTS: Subscales' internal consistency were very good, ranging from 0.71 to 0.83, but intraclass correlations between informants from the same communities were low. Factor analyses indicated a unidimensional structure for each scale. INTERPRETATION: These results show that the scale seems to provide reasonable assessments of the opinion of key informants regarding activation in their community. However, ranking communities based on the aggregated scores from local key informants may lead to classification problems.     

Technical skills for weight loss: preliminary data from a randomized trial

BACKGROUND: Optimal behavioral interventions for sustainable weight loss are uncertain. We therefore conducted a study among overweight/obese women comparing conventional dietary counseling of individuals (counseling-based intervention) to a novel, group-based skill-building intervention. METHODS: Eighty subjects were randomly assigned to either the counseling-based or to the skill-building intervention. Outcomes included weight loss, dietitian hours per group and per unit weight loss, and dollars spent per group and per unit weight lost. RESULTS: Weight loss at 6 months (follow-up rate 61.3%) in the counseling-based group was 8.8 lb (P = 0.0001), and in the skill-building group was 3.8 lb (P = 0.01). A total of 160 dietitian hours were required for the counseling-based group, and 131 for the skilled-building group. The counseling-based group cost an average of $21 per pound lost, while the skill-building cost an average of $48 per pound lost (P = 0.16). CONCLUSIONS: At 6 months, individualized office-based counseling produced more weight loss than a skill-building approach and cost less than half as much per pound of weight loss. Longer-term follow-up is required to determine if, as hypothesized, the skill-building intervention produces more sustainable weight loss.     

The Plk3-Cdc25 circuit

Polo-like kinases (Plks) are key regulators of the cell cycle, especially in the G2 phase and mitosis. They are incorporated into signaling networks that regulate many aspects of the cell cycle, including but not limited to centrosome maturation and separation, mitotic entry, chromosome segregation, mitotic exit, and cytokinesis. The Plks have well conserved 30-amino-acid elements, designated polo boxes (PBs), located in their carboxyl-termini, which with their flanking regions constitute a functional Polo-box domain (PBD). Members of the Plk family exist in a variety of organisms including Polo in Drosophila melanogaster; Cdc5 in Saccharomyces cerevisiae; Plo1 in Schizosaccharomyces pombe; Plx1 in Xenopus laevis; and Plk1, Snk/Plk2, Fnk/Prk/Plk3, and Sak in mammals. Polo, Cdc5, and Plo1 are essential for viability. The Plks can be separated into two groups according to their functions. The first group (Polo, Cdc5, plo1, Plx1, and Plk1) primarily performs mitotic functions, whereas the second group (Plk2 and Plk3) appears to have additional functions during the G1, S, and G2 phases of the cell cycle. Several contributions to this issue will discuss different aspects of Plk involvement in cell-cycle regulation. This review, therefore, will focus on the role of Plk3 in regulating Cdc25 phosphatase function and its effect on the cell cycle.     

Successful use of levosimendan in a patient with cardiogenic shock complicating acute myocardial infarction

Levosimendan is a new inodilator that improves cardiac contractility by sensitizing troponin C to calcium. This drug has proved to be effective in treating advanced congestive heart failure but has not been evaluated in cardiogenic shock. We present the case of a 54-year-old male patient treated successfully with levosimendan for cardiogenic shock following acute myocardial infarction. Treatment with dobulamine. revascularisation and itra-aortic balloon conterpulsation had first failed to improve his hemodynamic variables. Levosimendan induced a steady decline of increased pulmonary capillary wedge pressure, followed by an increase in cardiac index and mixed venous oxygen saturation. Left ventricular ejection fraction improved from 25% to 47%. Infusion of levosimendan can be used in cardiogenic shock without side effects and to improve hemodynamics and left ventricular function.