Solid phase microextraction as a short-term sampling technique for BTEX occupational exposure

Solid phase microextraction (SPME) has been widely used for many years in various applications, such as environmental and water samples, food and fragrance analysis, or biological fluids. The aim of this study was to suggest the SPME method as an alternative to conventional techniques used in the evaluation of worker exposure to benzene, toluene, ethylbenzene, and xylene (BTEX). Polymethylsiloxane-carboxen (PDMS/CAR) showed as the most effective stationary phase material for sorbing BTEX among other materials (polyacrylate, PDMS, PDMS/divinylbenzene, Carbowax/divinylbenzene). Various experimental conditions were studied to apply SPME to BTEX quantitation in field situations. The uptake rate of the selected fiber (75 microm PDMS/CAR) was determined for each analyte at various concentrations, relative humidities, and airflow velocities from static (calm air) to dynamic (> 200 cm/s) conditions. The SPME method also was compared with the National Institute of Occupational Safety and Health method 1501. Unlike the latter, the SPME approach fulfills the new requirement for the threshold limit value-short term exposure limit (TLV-STEL) of 2.5 ppm for benzene (8 mg/m(3))

Incidenceof out-of-hospital adult nontraumatic cardiac arrest presenting as a convulsion

Introduction: The majority of convulsions are due to an epileptic seizure or a convulsive syncope. The incidence of out-of-hospital cardiac arrest (OH-CA) presenting as a convulsion is unknown. Objective: This study aimed to measure the incidence of adult nontraumatic OH-CA presenting as a convulsion, a rate that has not been published so far, to the best of our knowledge. Methods: We prospectively collected all incoming calls with an out-of-hospital nontraumatic seizure as the chief complaint in patients >18 years old during a 24-month period. Among these calls, we collected cases identified as OH-CA by paramedics. Results: During the 24-month period, the emergency medical services (EMS) dispatch center received 561 calls for an out-of-hospital nontraumatic convulsion in an adult. Twelve cases were ultimately classified as CA. In this group, one bystander spontaneously reported that the patient was known for epilepsy. The incidence of OH-CA presenting as convulsions was therefore 2.1% of all calls for convulsion. Over the same period, the EMS dispatch center received 1,035 calls related to an adult nontraumatic OH-CA. Therefore, the rate of OH-CA presenting as a convulsion represented 1.2% of all adult nontraumatic OH-CA. Conclusion:L Only 12 cases out of the 531 calls for nontraumatic adult convulsions were confirmed OHCA (2.1%). Nevertheless, this unusual presentation of OH-CA must be recognized by dispatchers, even when a patient is reported by bystander as a known epileptic. Dispatchers should keep bystanders on the line or call them back before paramedics' arrival, and have them confirm the progressive return of a normal pat- tern of breathing and state of consciousness; if not, they should encourage the bystander to initiate CPR when necessary. An intervention should be implemented to improve the detection by dispatchers of OH-CA presenting as convulsion by the development of a specific interview and directed observation. For dispatchers, a past medical history of epilepsy should not be regarded as sufficient information to rule out OH-CA. It is mandatory that known epileptic patients should be monitored in the same way as nonepileptic patients.

Severe childhood encephalopathy with dyskinesia and prolonged cognitive disturbances: evidence for anti-N-methyl-d-aspartate receptor encephalitis.

Aim We report four cases of acquired severe encephalopathy with massive hyperkinesia, marked neurological and cognitive regression, sleep disturbance, prolonged mutism, and a remarkably delayed recovery (time to full recovery between 5 and 18mo) with an overall good outcome, and its association with anti-N-methyl-d-aspartate (anti-NMDA) receptor antibodies. Method We reviewed the four cases retrospectively and we also reviewed the literature. Results Anti-NMDA receptor antibodies (without ovarian teratoma detected so far) were found in the two children tested in this study. Interpretation The clinical features are similar to those first reported in 1992 by Sebire et al.,(1) and rarely recognized since. Sleep disturbance was not emphasized as part of the disorder, but appears to be an important feature, whereas coma is less certain and difficult to evaluate in this setting. The combination of symptoms, evolution (mainly seizures at onset), severity, paucity of abnormal laboratory findings, very slow recovery, and difficult management justify its recognition as a specific entity. The neuropathological substrate may be anatomically close to that involved in encephalitis lethargica, in which the same target functions (sleep and movement) are affected but in reverse, with hypersomnolence and bradykinesia. This syndrome closely resembles anti-NMDA receptor encephalitis, which has been reported in adults and is often paraneoplastic.

Melanopsin as a sleep modulator: circadian gating of the direct effects of light on sleep and altered sleep homeostasis in Opn4(-/-) mice.

Light influences sleep and alertness either indirectly through a well-characterized circadian pathway or directly through yet poorly understood mechanisms. Melanopsin (Opn4) is a retinal photopigment crucial for conveying nonvisual light information to the brain. Through extensive characterization of sleep and the electrocorticogram (ECoG) in melanopsin-deficient (Opn4(-/-)) mice under various light-dark (LD) schedules, we assessed the role of melanopsin in mediating the effects of light on sleep and ECoG activity. In control mice, a light pulse given during the habitual dark period readily induced sleep, whereas a dark pulse given during the habitual light period induced waking with pronounced theta (7-10 Hz) and gamma (40-70 Hz) activity, the ECoG correlates of alertness. In contrast, light failed to induce sleep in Opn4(-/-) mice, and the dark-pulse-induced increase in theta and gamma activity was delayed. A 24-h recording under a LD 1-hratio1-h schedule revealed that the failure to respond to light in Opn4(-/-) mice was restricted to the subjective dark period. Light induced c-Fos immunoreactivity in the suprachiasmatic nuclei (SCN) and in sleep-active ventrolateral preoptic (VLPO) neurons was importantly reduced in Opn4(-/-) mice, implicating both sleep-regulatory structures in the melanopsin-mediated effects of light. In addition to these acute light effects, Opn4(-/-) mice slept 1 h less during the 12-h light period of a LD 12ratio12 schedule owing to a lengthening of waking bouts. Despite this reduction in sleep time, ECoG delta power, a marker of sleep need, was decreased in Opn4(-/-) mice for most of the (subjective) dark period. Delta power reached after a 6-h sleep deprivation was similarly reduced in Opn4(-/-) mice. In mice, melanopsin's contribution to the direct effects of light on sleep is limited to the dark or active period, suggesting that at this circadian phase, melanopsin compensates for circadian variations in the photo sensitivity of other light-encoding pathways such as rod and cones. Our study, furthermore, demonstrates that lack of melanopsin alters sleep homeostasis. These findings call for a reevaluation of the role of light on mammalian physiology and behavior.

Chromosomal gene movements reflect the recent origin and biology of therian sex chromosomes

Mammalian sex chromosomes stem from ancestral autosomes and have substantially differentiated. It was shown that X-linked genes have generated duplicate intronless gene copies (retrogenes) on autosomes due to this differentiation. However, the precise driving forces for this out-of-X gene "movement" and its evolutionary onset are not known. Based on expression analyses of male germ-cell populations, we here substantiate and extend the hypothesis that autosomal retrogenes functionally compensate for the silencing of their X-linked housekeeping parental genes during, but also after, male meiotic sex chromosome inactivation (MSCI). Thus, sexually antagonistic forces have not played a major role for the selective fixation of X-derived gene copies in mammals. Our dating analyses reveal that although retrogenes were produced ever since the common mammalian ancestor, selectively driven retrogene export from the X only started later, on the placental mammal (eutherian) and marsupial (metatherian) lineages, respectively. Together, these observations suggest that chromosome-wide MSCI emerged close to the eutherian-marsupial split approximately 180 million years ago. Given that MSCI probably reflects the spread of the recombination barrier between the X and Y, crucial for their differentiation, our data imply that these chromosomes became more widely differentiated only late in the therian ancestor, well after the divergence of the monotreme lineage. Thus, our study also provides strong independent support for the recent notion that our sex chromosomes emerged, not in the common ancestor of all mammals, but rather in the therian ancestor, and therefore are much younger than previously thought

Cessation of alcohol drinking, tobacco smoking and the reversal of head and neck cancer risk.

BACKGROUND: Quitting tobacco or alcohol use has been reported to reduce the head and neck cancer risk in previous studies. However, it is unclear how many years must pass following cessation of these habits before the risk is reduced, and whether the risk ultimately declines to the level of never smokers or never drinkers. METHODS: We pooled individual-level data from case-control studies in the International Head and Neck Cancer Epidemiology Consortium. Data were available from 13 studies on drinking cessation (9167 cases and 12 593 controls), and from 17 studies on smoking cessation (12 040 cases and 16 884 controls). We estimated the effect of quitting smoking and drinking on the risk of head and neck cancer and its subsites, by calculating odds ratios (ORs) using logistic regression models. RESULTS: Quitting tobacco smoking for 1-4 years resulted in a head and neck cancer risk reduction [OR 0.70, confidence interval (CI) 0.61-0.81 compared with current smoking], with the risk reduction due to smoking cessation after >/=20 years (OR 0.23, CI 0.18-0.31), reaching the level of never smokers. For alcohol use, a beneficial effect on the risk of head and neck cancer was only observed after >/=20 years of quitting (OR 0.60, CI 0.40-0.89 compared with current drinking), reaching the level of never drinkers. CONCLUSIONS: Our results support that cessation of tobacco smoking and cessation of alcohol drinking protect against the development of head and neck cancer.

Risk determinants of acute mountain sickness in trekkers in the Nepali Himalaya: a 24-year follow-up.

OBJECTIVE: Exposure to altitude may lead to acute mountain sickness (AMS) in nonacclimatized individuals. We surveyed AMS prevalence and potential risk factors in trekkers crossing a 5400-m pass in Nepal and compared the results with those of 2 similar studies conducted 12 and 24 years earlier. METHODS: In April 2010, 500 surveys were distributed to English-speaking trekkers at 3500 m on their way to 5400 m, of which 332 (66%) surveys were returned complete. Acute mountain sickness was quantified with the Lake Louise Scoring System (LLSS, cutoff ≥3 and ≥5) and the Environmental Statistical Questionnaire III AMS-C score (ESQ-III, cutoff ≥0.7). We surveyed demographics, body mass index (BMI), smoking habit, rate of ascent, awareness of AMS, and acetazolamide use. RESULTS: Prevalence of AMS was 22%, 23%, and 48% (ESQ-III ≥0.7, LLSS ≥5, and LLSS ≥3, respectively) lower when compared with earlier studies. Risk factors for AMS were younger age, female sex, higher BMI, and smoking habit. Forty-two percent had elementary knowledge about the risk and prevention of AMS. Forty-four percent used acetazolamide. Trekkers took longer to climb from 3500 to 5400 m than in earlier studies. CONCLUSIONS: Prevalence of AMS continued to decline over a period of 24 years, likely as a result of slower ascent and increased use of acetazolamide. The AMS risk factors of younger age, female sex, and high BMI are consistent with prior studies. Awareness of risk and prevention of AMS remains low, indicating an opportunity to better educate trekkers and potentially further reduce AMS prevalence.

Exploring triangulation in infancy : Two contrasted cases.

Two contrasted father-mother-infant interactions are observed longitudinally during trilogue play. They illustrate the contribution of recent research to the exploration of triangulation in infancy: namely, the infant's capacity to handle triangular interactions and share her affects with her two parents, and the way that this capacity is recruited in functional versus problematic alliances. It is likely that an infant under stress when interacting with one parent will protest at that parent and also at the other. Such is the case when, for example, the father acts intrusively while playing with his baby. The infant is then driven to avert and turns to the mother. The regulation of this dyadic intrusion-avoidance pattern at family level depends on the family alliance. When coparenting is supportive, the mother validates the infant's bid for help without interfering with the father. Thus, the problematic pattern is contained in the dyad, and the infant's triangular capacities remain in the service of her own developmental goals. But when coparenting is hostile-competitive, the mother ignores the infant's bid or engages with her in a way that interferes with her play with her father. In this case, the infant's triangular capacities are used to relieve the tension between the parents. The importance of tracing family process back to infancy for family therapy is discussed.

Neuroanatomical and neuropsychological features of euthymic patients with bipolar disorder.

OBJECTIVE: Previous studies reported that the severity of cognitive deficits in euthymic patients with bipolar disorder (BD) increases with the duration of illness and postulated that progressive neuronal loss or shrinkage and white matter changes may be at the origin of this phenomenon. To explore this issue, the authors performed a case-control study including detailed neuropsychological and magnetic resonance imaging analyses in 17 euthymic elderly patients with BD and 17 healthy individuals. METHODS: Neuropsychological evaluation concerned working memory, episodic memory, processing speed, and executive functions. Volumetric estimates of the amygdala, hippocampus, entorhinal cortex, and anterior cingulate cortex were obtained using both voxel-based and region of interest morphometric methods. Periventricular and deep white matter were assessed semiquantitatively. Differences in cognitive performances and structural data between BD and comparison groups were analyzed using paired t-test or analysis of variance. Wilcoxon test was used in the absence of normal distribution. RESULTS: Compared with healthy individuals, patients with BD obtained significantly lower performances in processing speed, working memory, and episodic memory but not in executive functions. Morphometric analyses did not show significant volumetric or white matter differences between the two groups. CONCLUSIONS: Our results revealed impairment in verbal memory, working memory, and processing speed in euthymic older adults with BD. These cognitive deficits are comparable both in terms of affected functions and size effects to those previously reported in younger cohorts with BD. Both this observation and the absence of structural brain abnormalities in our cohort do not support a progressively evolving neurotoxic effect in BD.

Nanoparticle usage and protection measures in the manufacturing industry : a representative survey

Addressing the risks of nanoparticles requires knowledge about release into the environment and occupational exposure. However, such information currently is not systematically collected; therefore, this risk assessment lacks quantitative data. The goal was to evaluate the current level of nanoparticle usage in Swiss industry as well as health, safety, and environmental measures, and the number of potentially exposed workers. A representative, stratified mail survey was conducted among 1626 clients of the Swiss National Accident Insurance Fund (SUVA), which insures 80,000 manufacturing firms, representing 84% of all Swiss manufacturing companies (947 companies answered the survey for a 58.3% response rate). The extrapolation to all Swiss manufacturing companies results in 1309 workers (95% confidence interval [CI]: 1073 to 1545) potentially exposed to nanoparticles in 586 companies (95% CI: 145 to 1027). This corresponds to 0.08% of workers (95% CI: 0.06% to 0.09%) and to 0.6% of companies (95% CI: 0.2% to 1.1%). The industrial chemistry sector showed the highest percentage of companies using nanoparticles (21.2%). Other important sectors also reported nanoparticles. Personal protection equipment was the predominant protection strategy. Only a few applied specific environmental protection measures. This is the first nationwide representative study on nanoparticle use in the manufacturing sector. The information gained can be used for quantitative risk assessment. It can also help policymakers design strategies to support companies developing a safer use of nanomaterial. Notingthe current low use of nanoparticles, there is still time to proactively introduce protective methods. If the predicted "nano-revolution" comes true, now is the time to take action. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of occupational and Environmental Hygiene for the following free supplemental resource: a pdf file containing a detailed description of the approach to statistical analyses, English translation of the questionnaire, additional information for Figure 1, and additional information for the SUVA-code.] [Authors]

Documenting a time-bound, circular view of hierarchies: a microanalysis of parent-infant dyadic interaction.

This article presents a new theory that separates the levels of communication and relates them circularly, namely, by separating time from space/meaning variables. Documenting this proposition requires sequential microdescriptions--a far-out project in the field of family therapy. In an extensive study of clinical and nonclinical families, starting with available microanalytic data on nonverbal parent-infant dialogue, distinct time organizations have been found to modify the degree of circularity between the levels of interaction according to the observed types of engagement, that is, consensual, conflictual, and paradoxical. The double description of the dyad as a totality versus the dyad as a framing/developing organization imparts crucial information on how development proceeds in dyadic, co-evolutive systems, and presumably in larger ones too. In this perspective, a model is elaborated and then applied to a case description in our therapeutic consultation.

Traitement de l'hypertension artérielle chez le sujet obèse [Treatment of hypertension in obese patients].

Prevalence of obesity and hypertension has increased these last decades. Around 60 to 70% of the incidence of hypertension is related to obesity. The relationship between obesity and hypertension is now well established. The sympathetic nervous system and the renin-angiotensin-aldosterone (RAA) system are activated in obese patients, mostly by insulin, and predispose the kidney to reabsorb sodium and water. In obese patients with hypertension, it is recommended to target a blood pressure < 140/90 mmHg. Lifestyle changes (weight loss, physical activity, low-salt diets) are useful to decrease blood pressure but are difficult to maintain in the long-term. When drugs are necessary, drugs that are metabolically neutral should be used, and often need to be combined to other drug classes in order to achieve blood pressure target.

First episode schizophrenia and schizoaffective disorder: A psychiatric nosology

A nosological issue that has yet to be resolved relates to the diagnostic and clinical overlap of schizophrenia and schizoaffective disorder. Thus, the aim of this study was to compare, within a treated epidemiological cohort of first episode patients, the clinical characteristics of patients with schizophrenia (FES) or schizoaffective disorder (FESA). Medical fi le audit methodology was employed to collect information on 704 first episode psychosis patients (FEP), among which 283 patients had a fi nal diagnosis of FES and 64 patients with a fi nal diagnosis of FESA. These patients were treated at the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia. Patients with FES were signifi cantly more likely to have a longer prodrome (P = .020), longer duration of untreated psychosis (P < .001), and earlier age of onset (P = .004) compared to FESA. At service entry, FESA patients had more severe levels of psychopathology (P = .020), which was due to the presence of manic symptoms (P < .001); consequently, requiring a greater number of inpatient admissions (P = .017). At discharge, depressive symptoms were more severe in those with FESA (P = .011). There are signifi cant differences in the phenomenology of schizophrenia and schizoaffective disorder during early illness course; supporting the notion that these are two discernable disorders.

Emergence of young human genes after a burst of retroposition in primates.

The origin of new genes through gene duplication is fundamental to the evolution of lineage- or species-specific phenotypic traits. In this report, we estimate the number of functional retrogenes on the lineage leading to humans generated by the high rate of retroposition (retroduplication) in primates. Extensive comparative sequencing and expression studies coupled with evolutionary analyses and simulations suggest that a significant proportion of recent retrocopies represent bona fide human genes. We estimate that at least one new retrogene per million years emerged on the human lineage during the past approximately 63 million years of primate evolution. Detailed analysis of a subset of the data shows that the majority of retrogenes are specifically expressed in testis, whereas their parental genes show broad expression patterns. Consistently, most retrogenes evolved functional roles in spermatogenesis. Proteins encoded by X chromosome-derived retrogenes were strongly preserved by purifying selection following the duplication event, supporting the view that they may act as functional autosomal substitutes during X-inactivation of late spermatogenesis genes. Also, some retrogenes acquired a new or more adapted function driven by positive selection. We conclude that retroduplication significantly contributed to the formation of recent human genes and that most new retrogenes were progressively recruited during primate evolution by natural and/or sexual selection to enhance male germline function.