Salivary cortisol and self-reported stress among persons with environmental annoyance

OBJECTIVES: Increased vulnerability to stress has been suggested as a possible mechanism behind medically unexplained conditions such as sensitivity to electricity and common smells. This study examined whether subjective environmental annoyance among the general population is associated with increased physiological reactivity or subjective stress scores. METHODS: Four groups were studied (N=141): an electrically annoyed (N=17), a smell-annoyed (N=29), and a generally annoyed group (N=39) and a reference group matched for age, gender, and socioeconomic status (N=56). Over 5 days, the participants collected saliva for cortisol determination at awakening, 30 minutes after awakening, 8 hours after awakening, and at 9 o'clock in the evening. On the evening preceding the fifth day, the participants ingested a 0.5-mg dexamethasone tablet so that possible differential suppression of the hypothalamic-pituitary-adrenal (HPA) axis could be assessed. Each day, the participants also rated their subjective stress and health complaints. RESULTS: No significant differences were found between the groups regarding cortisol secretion over 5 days. The dexamethasone suppression test showed inhibited cortisol secretion in all four groups. No associations were found between the cortisol concentrations and the self-reported stress scores or subjective health complaints. CONCLUSIONS: Although the environmentally annoyed groups showed no signs of increased HPA-axis activation, being annoyed by both electrical devices and smells seems to be related to increased psychological activation in terms of self-reported stress. Because the participants were otherwise healthy and recruited from the general population, the results imply that subtle psychological stress processes may be important in the early development of environmental annoyance.     

Neuroblastoma cell death in response to docosahexaenoic acid: sensitization to chemotherapy and arsenic-induced oxidative stress

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid vital for the developing nervous system and significantly decreased in neuroblastoma cells compared to nontransformed nervous tissue. We investigated whether supplementation of DHA affects the susceptibility of neuroblastoma cells to oxidative stress generated endogenously and in response to cytotoxic therapy. DHA, but not the monounsaturated oleic acid (OA), induced dose- and time-dependent neuroblastoma cell death. DHA supplementation was associated with depolarization of the mitochondrial membrane potential, production of reactive oxygen species (ROS) and accumulation of DNA in sub-G1 phase of the cell cycle. The antioxidant, vitamin E, inhibited mitochondrial depolarization and subsequent cell death induced by DHA, whereas, the mitochondrial pore inhibitor, cyclosporin A, partly inhibited DHA-induced neuroblastoma cell death. Depletion of glutathione by L-buthionine-sulfoximine significantly enhanced the cytotoxic effects of DHA. Nontransformed fibroblasts were not substantially affected by DHA. DHA, but not OA, significantly enhanced the cytotoxicity of cisplatin, doxorubicin and irinotecan both in chemosensitive and in multidrug-resistant neuroblastoma cells. DHA potently sensitized neuroblastoma cells to a clinically relevant concentration (1 microM) of arsenic trioxide (As2O3) and enhanced the effect of the nonsteroidal antiinflammatory drug (NSAID), diclofenac. These findings provide experimental evidence that the omega-3 fatty acid, DHA, is cytotoxic to drug-resistant neuroblastoma. The potent action of DHA with arsenic trioxide, NSAID and chemotherapeutic agents suggests clinical testing of this therapeutic concept in children with neuroblastoma.     

24-h Systolic blood pressure and heart rate recordings in lean and obese adolescents

OBJECTIVE: We assessed the hypothesis that differences in day and night-time systolic blood pressure (SBP) and heart rate (HR) recordings were smaller in obese versus lean children and adolescents, and whether measurements obtained during a school week or during weekends or holidays influenced these nocturnal falls. We also wanted to determine whether the results were influenced by gender. METHODS: Ambulatory 24-h BP and HR measurements were performed in 80 subjects, 51 girls and 29 boys. Lean (n = 25) and obese (n = 55) subjects were classified according to body mass index (BMI)-standard deviation (SD) criteria. Forty-eight subjects had their 24-h recordings performed during a school week and 32 during leisure time. RESULTS: The SBP nocturnal dipping response was less pronounced in obese subjects (16.2 +/- 6.3 mmHg) compared with lean controls (21.1 +/- 5.7 mmHg) (P < 0.01) of which the girls constituted most of the difference. HR change between day and night was similar in both groups being approximately 15 b/min. A small but statistical negative correlation was observed between BMI-SD and nocturnal fall in SBP (r = -0.3, P = 0.0065). In all subjects, regardless of BMI-SD, daytime SBP was higher when readings were obtained during a school week (123 +/- 7 mmHg) than during weekends or holidays (119 +/- 7 mmHg) (P = 0.029). CONCLUSION: Obese children and adolescents showed smaller nocturnal falls in SBP compared with lean subjects. This pattern may cause increased cardiovascular loading; thus, it may reflect an early sign of high blood pressure development and adds to cardiovascular risk in young obese individuals.     

Predicting spontaneous termination of atrial fibrillation using the surface ECG

By recognizing and characterizing conditions under which atrial fibrillation (AF) is likely to terminate spontaneously or be sustained, improved treatment of sustained AF may result and unnecessary treatment of self-terminating AF avoided. Time-frequency measures that characterize AF, such as fibrillatory frequency, amplitude, and waveform shape (exponential decay), are extracted from the residual ECG following QRST cancellation. Three complexity measures are also studied, characterizing the degree of organization of atrial activity. All measures are analysed using a training set, consisting of 20 recordings of AF with known termination properties, and a test set of 30 recordings. Spontaneous termination was best predicted by a low and stable fibrillatory frequency and a low exponential decay. Using these predictors, 90% of the test set was correctly classified into terminating and sustained AF. Neither fibrillation amplitude nor the complexity measures differed significantly between the two sets.     

The phenomenon of the inducement of demand and various concepts in the economics of health

The article looks at the behaviour of practitioners and patients from an economic point of view, in particular at supplier-induced demand (SID). The objective is to be able to describe the factors which impact on the market for health care. To define the market for health care/dental care in general and the SID concept in particular, the following economic terminology is relevant. uncertainty, asymmetric information, moral hazard, and the agency relationship between practitioner and patient. Essentially SID results from the existence of asymmetric information (information "gap") on the health care market. The patient is less informed than the practitioner and cannot accurately assess his need for medical care. Hence decision-making authority is delegated to the practitioner who acts as the patient's agent to determine the optimal (amount of) care. This enables the practitioner to influence the demand for medical/dental care. If the practitioner is more interested in the rate of return than in the patient s need for care, a difference might arise between the care recommended by the practitioner and the care the patient would have asked for if he had the same level of information as the practitioner. This difference is called the amount of SID.     

Streptococcal Infections in Patients with Chronic Granulomatous Disease: Case Report and Review of the Literature

Streptococcus intermedius caused a liver abscess in a patient with chronic granulomatous disease (CGD). In contrast to typical staphylococcal abscesses in CGD, this abscess was liquid, easily drained, and resolved without surgery or steroids. This case and literature review provide insight into this organism's pathogenesis, including in CGD.