99 resultados para Saliva Cortisol
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We used exome sequencing of blood DNA in four unrelated patients to identify the genetic basis of metaphyseal chondromatosis with urinary excretion of D-2-hydroxy-glutaric acid (MC-HGA), a rare entity comprising severe chondrodysplasia, organic aciduria, and variable cerebral involvement. No evidence for recessive mutations was found; instead, two patients showed mutations in IDH1 predicting p.R132H and p.R132S as apparent somatic mosaicism. Sanger sequencing confirmed the presence of the mutation in blood DNA in one patient, and in blood and saliva (but not in fibroblast) DNA in the other patient. Mutations at codon 132 of IDH1 change the enzymatic specificity of the cytoplasmic isocitrate dehydrogenase enzyme. They result in increased D-2-hydroxy-glutarate production, α-ketoglutarate depletion, activation of HIF-1α (a key regulator of chondrocyte proliferation at the growth plate), and reduction of N-acetyl-aspartyl-glutamate level in glial cells. Thus, somatic mutations in IDH1 may explain all features of MC-HGA, including sporadic occurrence, metaphyseal disorganization, and chondromatosis, urinary excretion of D-2-hydroxy-glutaric acid, and reduced cerebral myelinization.
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In order to evaluate the effect of head injury in severely traumatized patients on the response of plasma cortisol, glucagon, insulin, glucose, and FFA as well as urinary N and catecholamines excretions, 36 patients were prospectively studied over 5 consecutive days following injury. They were divided into three groups: group I, severe isolated head injury (n = 14); group II, multiple injury combined with severe head injury (n = 12); group III multiple injury without head injury (n = 10). The results demonstrate similar hormonal and metabolic changes between these three groups of patients, characterized by elevated urinary adrenaline, noradrenaline excretion, increased cortisol, glucagon, insulin plasma levels throughout the study and elevated N urinary excretion with strongly negative N balances during the first 5 days postinjury. A significant correlation was observed between N intake and 5 day cumulated N balance (r = 0.63, p less than 0.001). In addition, N balance was negatively correlated with urinary excretion of adrenaline (r = -0.47, p less than 0.01) and noradrenaline (r = -0.44, p less than 0.05) as well as plasma levels of glucagon (r = -0.44, p less than 0.05). Isolated severe head injury seems to induce a full response in the secretion of the catabolic counterregulatory hormones comparable to that encountered in patients with multiple injury and associated with a marked increase in protein catabolism; additional noncranial major injury does not seem to enhance these responses.
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Objectif Un bolus unique d'étomidate inhibe une enzyme mitochondriale impliquée dans la synthèse du cortisol. Au sein de notre institution, tout patient candidat à une chirurgie cardiaque reçoit de l'étomidate à l'induction de l'anesthésie. L'objectif de cette étude a été de déterminer l'incidence des dysfonctions surrénaliennes chez les patients bénéficiant d'une chirurgie cardiaque et nécessitant de hautes doses de noradrénaline au cours de la période postopératoire. Type d'étude Étude rétrospective descriptive dans l'unité de réanimation d'un centre hospitalier universitaire. Patients et méthodes Soixante-trois patients admis en réanimation après chirurgie cardiaque nécessitant plus de 0,2μg/kg par minute de noradrénaline au cours des premières 48 heures postopératoires ont été étudiés. L'insuffisance surrénalienne absolue a été définie par un cortisol basal inférieur à 414nmo/l (15μg/dl), l'insuffisance surrénalienne relative par un cortisol basal entre 414nmo/l (15μg/dl) et 938nmo/l (34μg/dl) avec une augmentation de la cortisolémie (à 60 minutes après un test de stimulation par 250μg de corticotropine de synthèse) inférieure à 250nmo/l (9μg/dl). Résultats Quatorze patients (22 %) ont présenté une fonction surrénalienne normale, 10 (16 %) une insuffisance surrénalienne absolue et 39 (62 %) une insuffisance surrénalienne relative. Tous les patients ont reçu une substitution stéroïdienne, sans aucune différence d'évolution clinique entre les différents groupes. Conclusion L'incidence de l'insuffisance surrénalienne chez les patients qui ont reçu un bolus d'étomidate à l'induction, lors d'une chirurgie cardiaque avec circulation extracorporelle, et présenté une défaillance circulatoire postopératoire, est élevée.
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The aim of this study was to evaluate the forensic protocol recently developed by Qiagen for the QIAsymphony automated DNA extraction platform. Samples containing low amounts of DNA were specifically considered, since they represent the majority of samples processed in our laboratory. The analysis of simulated blood and saliva traces showed that the highest DNA yields were obtained with the maximal elution volume available for the forensic protocol, that is 200 ml. Resulting DNA extracts were too diluted for successful DNA profiling and required a concentration. This additional step is time consuming and potentially increases inversion and contamination risks. The 200 ml DNA extracts were concentrated to 25 ml, and the DNA recovery estimated with real-time PCR as well as with the percentage of SGM Plus alleles detected. Results using our manual protocol, based on the QIAamp DNA mini kit, and the automated protocol were comparable. Further tests will be conducted to determine more precisely DNA recovery, contamination risk and PCR inhibitors removal, once a definitive procedure, allowing the concentration of DNA extracts from low yield samples, will be available for the QIAsymphony.
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Caprine and ovine IgA were identified by cross-reaction with anti-human and anti-bovine IgA sera in colostrum, mature milk, saliva, urine and serum. Secretory component (SC) was shown in the free form and associated with polymeric serum IgA in secretions. Mean molecular weights were determined for the IgA and the free secretory components. The high IgA content of saliva suggested that it was a major secretory immunoglobulin in these species. Traces of secretory IgA were also found in normal sera but most of the serum IgA had no secretory determinant. Secretory IgA, serum IgA and free secretory component were purified. Levels of the sheep and goat immunoglobulins were measured in various fluids.
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Different interactions have been described between glucocorticoids and the product of the ob gene leptin. Leptin can inhibit the activation of the hypothalamo-pituitary-adrenal axis by stressful stimuli, whereas adrenal glucocorticoids stimulate leptin production by the adipocyte. The present study was designed to investigate the potential direct effects of leptin to modulate glucocorticoid production by the adrenal. Human adrenal glands from kidney transplant donors were dissociated, and isolated primary cells were studied in vitro. These cells were preincubated with recombinant leptin (10(-10)-10(-7) M) for 6 or 24 h, and basal or ACTH-stimulated cortisol secretion was subsequently measured. Basal cortisol secretion was unaffected by leptin, but a significant and dose-dependent inhibition of ACTH-stimulated cortisol secretion was observed [down by 29 +/- 0.1% of controls with the highest leptin dose, P < 0.01 vs. CT (unrelated positive control)]. This effect of leptin was also observed in rat primary adrenocortical cells, where leptin inhibited stimulated corticosterone secretion in a dose-dependent manner (down by 46 +/- 0.1% of controls with the highest leptin dose, P < 0.001 vs. CT). These effects of leptin in adrenal cells are likely mediated by the long isoform of the leptin receptor (OB-R), because its transcript was found to be expressed in the adrenal tissue and leptin had no inhibitory effect in adrenal glands obtained from db/db mice. Therefore, leptin inhibits directly stimulated cortisol secretion from human and rat adrenal glands, and this may represent an important mechanism to modulate glucocorticoid levels in various metabolic states.
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Refractory status epilepticus (RSE)-that is, seizures resistant to at least two antiepileptic drugs (AEDs)-is generally managed with barbiturates, propofol, or midazolam, despite a low level of evidence (Rossetti, 2007). When this approach fails, the need for alternative pharmacologic and nonpharmacologic strategies emerges. These have been investigated even less systematically than the aforementioned compounds, and are often used, sometimes in succession, in cases of extreme refractoriness (Robakis & Hirsch, 2006). Several possibilities are reviewed here. In view of the marked heterogeneity of reported information, etiologies, ages, and comedications, it is extremely difficult to evaluate a given method, not to say to compare different strategies among them. Pharmacologic Approaches Isoflurane and desflurane may complete the armamentarium of anesthetics,' and should be employed in a ''close'' environment, in order to prevent intoxication of treating personnel. c-Aminobutyric acid (GABA)A receptor potentiation represents the putative mechanism of action. In an earlier report, isoflurane was used for up to 55 h in nine patients, controlling seizures in all; mortality was, however, 67% (Kofke et al., 1989). More recently, the use of these inhalational anesthetics was described in seven subjects with RSE, for up to 26 days, with an endtidal concentration of 1.2-5%. All patients required vasopressors, and paralytic ileus occurred in three; outcome was fatal in three patients (43%) (Mirsattari et al., 2004). Ketamine, known as an emergency anesthetic because of its favorable hemodynamic profile, is an N-methyl-daspartate (NMDA) antagonist; the interest for its use in RSE derives from animal works showing loss of GABAA efficacy and maintained NMDA sensitivity in prolonged status epilepticus (Mazarati & Wasterlain, 1999). However, to avoid possible neurotoxicity, it appears safer to combine ketamine with GABAergic compounds (Jevtovic-Todorovic et al., 2001; Ubogu et al., 2003), also because of a likely synergistic effect (Martin & Kapur, 2008). There are few reported cases in humans, describing progressive dosages up to 7.5 mg/kg/h for several days (Sheth & Gidal, 1998; Quigg et al., 2002; Pruss & Holtkamp, 2008), with moderate outcomes. Paraldehyde acts through a yet-unidentified mechanism, and appears to be relatively safe in terms of cardiovascular tolerability (Ramsay, 1989; Thulasimani & Ramaswamy, 2002), but because of the risk of crystal formation and its reactivity with plastic, it should be used only as fresh prepared solution in glass devices (Beyenburg et al., 2000). There are virtually no recent reports regarding its use in adults RSE, whereas rectal paraldehyde in children with status epilepticus resistant to benzodiazepines seems less efficacious than intravenous phenytoin (Chin et al., 2008). Etomidate is another anesthetic agent for which the exact mechanism of action is also unknown, which is also relatively favorable regarding cardiovascular side effects, and may be used for rapid sedation. Its use in RSE was reported in eight subjects (Yeoman et al., 1989). After a bolus of 0.3 mg/kg, a drip of up to 7.2 mg/kg/h for up to 12 days was administered, with hypotension occurring in five patients; two patients died. A reversible inhibition of cortisol synthesis represents an important concern, limiting its widespread use and implying a careful hormonal substitution during treatment (Beyenburg et al., 2000). Several nonsedating approaches have been reported. The use of lidocaine in RSE, a class Ib antiarrhythmic agent modulating sodium channels, was reviewed in 1997 (Walker & Slovis, 1997). Initial boluses up to 5 mg/kg and perfusions of up to 6 mg/kg/h have been mentioned; somewhat surprisingly, at times lidocaine seemed to be successful in controlling seizures in patients who were refractory to phenytoin. The aforementioned dosages should not be overshot, in order to keep lidocaine levels under 5 mg/L and avoid seizure induction (Hamano et al., 2006). A recent pediatric retrospective survey on 57 RSE episodes (37 patients) described a response in 36%, and no major adverse events; mortality was not given (Hamano et al., 2006 Verapamil, a calcium-channel blocker, also inhibits P-glycoprotein, a multidrug transporter that may diminish AED availability in the brain (Potschka et al., 2002). Few case reports on its use in humans are available; this medication nevertheless appears relatively safe (under cardiac monitoring) up to dosages of 360 mg/day (Iannetti et al., 2005). Magnesium, a widely used agent for seizures elicited by eclampsia, has also been anecdotally reported in RSE (Fisher et al., 1988; Robakis & Hirsch, 2006), but with scarce results even at serum levels of 14 mm. The rationale may be found in the physiologic blockage of NMDA channels by magnesium ions (Hope & Blumenfeld, 2005). Ketogenic diet has been prescribed for decades, mostly in children, to control refractory seizures. Its use in RSE as ''ultima ratio'' has been occasionally described: three of six children (Francois et al., 2003) and one adult (Bodenant et al., 2008) were responders. This approach displays its effect subacutely over several days to a few weeks. Because ''malignant RSE'' seems at times to be the consequence of immunologic processes (Holtkamp et al., 2005), a course of immunomodulatory treatment is often advocated in this setting, even in the absence of definite autoimmune etiologies (Robakis & Hirsch, 2006); steroids, adrenocorticotropic hormone (ACTH), plasma exchanges, or intravenous immunoglobulins may be used alone or in sequential combination. Nonpharmacologic Approaches These strategies are described somewhat less frequently than pharmacologic approaches. Acute implantation of vagus nerve stimulation (VNS) has been reported in RSE (Winston et al., 2001; Patwardhan et al., 2005; De Herdt et al., 2009). Stimulation was usually initiated in the operation room, and intensity progressively adapted over a few days up to 1.25 mA (with various regimens regarding the other parameters), allowing a subacute seizure control; one transitory episode of bradycardia/asystole has been described (De Herdt et al., 2009). Of course, pending identification of a definite seizure focus, resective surgery may also be considered in selected cases (Lhatoo & Alexopoulos, 2007). Low-frequency (0.5 Hz) transcranial magnetic stimulation (TMS) at 90% of the resting motor threshold has been reported to be successful for about 2 months in a patient with epilepsia partialis continua, but with a weaning effect afterward, implying the need for a repetitive use (Misawa et al., 2005). More recently, TMS was applied in a combination of a short ''priming'' high frequency (up to 100 Hz) and longer runs of low-frequency stimulations (1 Hz) at 90-100% of the motor threshold in seven other patients with simple-partial status, with mixed results (Rotenberg et al., 2009). Paradoxically at first glance, electroconvulsive treatment may be found in cases of extremely resistant RSE. A recent case report illustrates its use in an adult patient with convulsive status, with three sessions (three convulsions each) carried out over 3 days, resulting in a moderate recovery; the mechanism is believed to be related to modification of the synaptic release of neurotransmitters (Cline & Roos, 2007). Therapeutic hypothermia, which is increasingly used in postanoxic patients (Oddo et al., 2008), has been the object of a recent case series in RSE (Corry et al., 2008). Reduction of energy demand, excitatory neurotransmission, and neuroprotective effects may account for the putative mechanism of action. Four adult patients in RSE were cooled to 31_-34_C with an endovascular system for up to 90 h, and then passively rewarmed over 2-50 h. Seizures were controlled in two patients, one of whom died; also one of the other two patients in whom seizures continued subsequently deceased. Possible side effects are related to acid-base and electrolyte disturbances, and coagulation dysfunction including thrombosis, infectious risks, cardiac arrhythmia, and paralytic ileus (Corry et al., 2008; Cereda et al., 2009). Finally, anecdotic evidence suggests that cerebrospinal fluid (CSF)-air exchange may induce some transitory benefit in RSE (Kohrmann et al., 2006); although this approach was already in use in the middle of the twentieth century, the mechanism is unknown. Acknowledgment A wide spectrum of pharmacologic (sedating and nonsedating) and nonpharmacologic (surgical, or involving electrical stimulation) regimens might be applied to attempt RSE control. Their use should be considered only after refractoriness to AED or anesthetics displaying a higher level of evidence. Although it seems unlikely that these uncommon and scarcely studied strategies will influence the RSE outcome in a decisive way, some may be interesting in particular settings. However, because the main prognostic determinant in status epilepticus appears to be related to the underlying etiology rather than to the treatment approach (Rossetti et al., 2005, 2008), the safety issue should always represent a paramount concern for the prescribing physician. Conclusion The author confirms that he has read the Journal's position on issues involved in ethical publication and affirms that this paper is consistent with those guidelines.
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PURPOSE: Nonvisual light-dependent functions in humans are conveyed mainly by intrinsically photosensitive retinal ganglion cells, which express melanopsin as photopigment. We aimed to identify the effects of circadian phase and sleepiness across 24 hours on various aspects of the pupil response to light stimulation. METHODS: We tested 10 healthy adults hourly in two 12-hour sessions covering a 24-hour period. Pupil responses to narrow bandwidth red (635 ± 18 nm) and blue (463 ± 24 nm) light (duration of 1 and 30 seconds) at equal photon fluxes were recorded, and correlated with salivary melatonin concentrations at the same circadian phases and to subjective sleepiness ratings. The magnitude of pupil constriction was determined from minimal pupil size. The post-stimulus pupil response was assessed from the pupil size at 6 seconds following light offset, the area within the redilation curve, and the exponential rate of redilation. RESULTS: Among the measured parameters, the pupil size 6 seconds after light offset correlated with melatonin concentrations (P < 0.05) and showed a significant modulation over 24 hours with maximal values after the nocturnal peak of melatonin secretion. In contrast, the post-stimulus pupil response following red light stimulation correlated with subjective sleepiness (P < 0.05) without significant changes over 24 hours. CONCLUSIONS: The post-stimulus pupil response to blue light as a marker of intrinsic melanopsin activity demonstrated a circadian modulation. In contrast, the effect of sleepiness was more apparent in the cone contribution to the pupil response. Thus, pupillary responsiveness to light is under influence of the endogenous circadian clock and subjective sleepiness.
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Objectives: Ethanol is well-known to impair driving ability. The major aim of this study was to evaluate the number of drivers driving under the influence of ethanol in a population of randomly controlled drivers. Methods: 1016 drivers were randomly controlled at 27 different locations in Western Switzerland from October 2006 to April 2008. Drivers were controlled for alcohol consumption with a breathalyzer according to the Swiss Road traffic law. If the result was equal or higher than an equivalent of a blood alcohol concentration of 0.8 g/kg, a blood sample was taken; otherwise, a saliva sample was obtained. Blood and saliva were analysed for ethanol by Head-space gas chromatography coupled with a FID detector. Results: Among the controlled drivers, men (69%) predominated over female (31%). The mean age was 41 (range: 16 90). For 968 drivers (95.3%) ethanol was not detected in blood or saliva. These drivers were not under the influence of ethanol. Ethanol was detected in saliva or blood of 48 drivers (4.7%). Among these drivers, blood alcohol concentration (BAC) was above the legal limit of 0.8 g/kg (serious offence) in 14 cases (1.4% of the total population). BAC were in the range of 0.91 to 2.43 g/kg (mean: 1.32 g/kg, median: 1.11 g/kg). Among these 14 cases, men (13 cases, 93%) were over represented. No ethanol was found in the population of truck drivers (17 cases). 986 drivers were car drivers and 46 of them have drunk ethanol (5%). 13 bikers were controlled and 2 of them have drunk ethanol (15%). Conclusion: Driving under the influence of ethanol concerned about 5% of a population of randomly controlled drivers, and 1,4% of the drivers had a blood alcohol concentration higer than 0.8 g/kg (legale limit for a serious offence).
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A passive sampling device called Monitor of NICotine or "MoNIC", was constructed and evaluated by IST laboratory for determining nicotine in Second Hand Tobacco Smoke (SHTS) or Environmental Tobacco Smoke (ETS). Vapour nicotine was passively collected on a potassium bisulfate treated glass fibre filter as collection medium. Analysis of collected nicotine on the treated filter by gas chromatography equipped with Thermoionic-Specific Detector (GC-TSD) after liquid-liquid extraction of 1mL of 5N NaOH : 1 mL of n-heptane saturated with NH3 using quinoline as internal standard. Based on nicotine amount of 0.2 mg/cigarette as the reference, the inhaled Cigarette Equivalents (CE) by non-smokers can be calculated. Using the detected CE on the badge for non-smokers, and comparing with amount of nicotine and cotinine level in saliva of both smokers and exposed non-smokers, we can confirm the use of the CE concept for estimating exposure to ETS. The regional CIPRET (Center of information and prevention of the addiction to smoking) of different cantons (Valais (VS), Vaud (VD), Neuchâtel (NE) and Fribourg (FR)) are going to organize a big campaign on the subject of the passive addiction to smoking. This campaign took place in 2007-2008 and has for objective to inform clearly the Swiss population of the dangerousness of the passive smoke. More than 3'900 MoNIC badges were gracefully distributed to Swiss population to perform a self-monitoring of population exposure level to ETS, expressed in term of CE. Non-stimulated saliva was also collected to determine ETS biomarkers nicotine/cotinine levels of participating volunteers. Results of different levels of CE in occupational and non-occupational situations in relation with ETS were presented in this study. This study, unique in Switzerland, has established a base map on the population's exposure to SHTS. It underscored the fact that all the Swiss people involved in this campaign (N=1241) is exposed to passive smoke, from <0.2 cig/d (10.8%), 1-2 to more than 10 cig/d (89.2%). In the area of high exposure (15-38 cig/d), are the most workers in public restaurant, cafe, bar, disco. By monitoring ETS tracer nicotine and its biomarkers, salivary nicotine and cotinine, it is demonstrated that the MoNIC badge can serve as indicator of CE passive smoking. The MoNIC badge, accompanied with content of salivary nicotine/cotinine can serve as a tool of evaluation of the ETS passive smoking and contributes to supply useful data for future epidemiological studies. It is also demonstrated that the salivary nicotine (without stimulation) is a better biomarker of ETS exposure than cotinine.
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There is anecdotal evidence that athletes use the banned substance Synacthen because of its perceived benefit with its associated rise in cortisol. To test the performance-enhancing effects of Synacthen, eight trained cyclists completed two, 2-day exercise sessions separated by 7-10 days. On the first day of each 2-day exercise session, subjects received either Synacthen (0.25 mg, TX) or placebo (PLA) injection. Performance was assessed by a 20-km time trial (TT) after a 90-min fatigue period on day 1 and without the fatiguing protocol on day 2. Plasma androgens and ACTH concentrations were measured during the exercise bouts as well as the rate of perceived exertion (RPE). Spot urines were analyzed for androgens and glucocorticoids quantification. Basal plasma hormones did not differ significantly between PLA and TX groups before and 24 h after the IM injection (P > 0.05). After TX injection, ACTH peaked at 30 min and hormone profiles were significantly different compared to the PLA trial (P < 0.001). RPE increased significantly in both groups as the exercise sessions progressed (P < 0.001) but was not influenced by treatment. The time to completion of the TT was not affected on both days by Synacthen treatment. In the present study, a single IM injection of synthetic ACTH did not improve either acute or subsequent cycling performance and did not influence perceived exertion. The investigated urinary hormones did not vary after treatment, reinforcing the difficulty for ACTH abuse detection.
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MicroRNAs (miRs) are involved in the pathogenesis of several neoplasms; however, there are no data on their expression patterns and possible roles in adrenocortical tumors. Our objective was to study adrenocortical tumors by an integrative bioinformatics analysis involving miR and transcriptomics profiling, pathway analysis, and a novel, tissue-specific miR target prediction approach. Thirty-six tissue samples including normal adrenocortical tissues, benign adenomas, and adrenocortical carcinomas (ACC) were studied by simultaneous miR and mRNA profiling. A novel data-processing software was used to identify all predicted miR-mRNA interactions retrieved from PicTar, TargetScan, and miRBase. Tissue-specific target prediction was achieved by filtering out mRNAs with undetectable expression and searching for mRNA targets with inverse expression alterations as their regulatory miRs. Target sets and significant microarray data were subjected to Ingenuity Pathway Analysis. Six miRs with significantly different expression were found. miR-184 and miR-503 showed significantly higher, whereas miR-511 and miR-214 showed significantly lower expression in ACCs than in other groups. Expression of miR-210 was significantly lower in cortisol-secreting adenomas than in ACCs. By calculating the difference between dCT(miR-511) and dCT(miR-503) (delta cycle threshold), ACCs could be distinguished from benign adenomas with high sensitivity and specificity. Pathway analysis revealed the possible involvement of G2/M checkpoint damage in ACC pathogenesis. To our knowledge, this is the first report describing miR expression patterns and pathway analysis in sporadic adrenocortical tumors. miR biomarkers may be helpful for the diagnosis of adrenocortical malignancy. This tissue-specific target prediction approach may be used in other tumors too.
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Leishmaniases are vector-borne diseases due to the protozoan parasite Leishmania . Since no prevention method is available and as current therapy is costly, often poorly tolerated and not always efficacious, the development of alternative therapies, including vaccines, constitutes the priority in the fight of Leishmania infection. This review focuses on recent advances in the development of vaccines against leishmaniasis, with emphasis on the cutaneous form. Indeed, the fact that recovery from leishmaniasis is associated with immunity against new infection provides a rational basis for the development of vaccination strategy against infection with Leishmania . Evidence from animal studies demonstrate that protection can be achieved following infection with live-attenuated Leishmania as well as through immunization with purified proteins or DNA vaccines. In addition, recent results have shown that immunization against the saliva of the insect vector could have synergistic effects with conventional vaccination. Finally, vaccination using dendritic cells was recently demonstrated as a possible tool for Leishmania vaccination.
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The goal of this study was to compare the quantity and purity of DNA extracted from biological tracesusing the QIAsymphony robot with that of the manual QIAamp DNA mini kit currently in use in ourlaboratory. We found that the DNA yield of robot was 1.6-3.5 times lower than that of the manualprotocol. This resulted in a loss of 8% and 29% of the alleles correctly scored when analyzing 1/400 and 1/800 diluted saliva samples, respectively. Specific tests showed that the QIAsymphony was at least 2-16times more efficient at removing PCR inhibitors. The higher purity of the DNA may therefore partlycompensate for the lower DNA yield obtained. No case of cross-contamination was observed amongsamples. After purification with the robot, DNA extracts can be automatically transferred in 96-wellsplates, which is an ideal format for subsequent RT-qPCR quantification and DNA amplification. Lesshands-on time and reduced risk of operational errors represent additional advantages of the robotic platform.
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Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.