Gnathotrichus sulcatus: synergistic response to enantiomers of the aggregation pheromone sulcatol.

In laboratory and field bioassays, Gnathotrichus sulcatus responded to sulcatol (6-methyl-5-hepten-2-ol) only when both enantiomers were present. Response was greater to racemic sulcatol than to a mixture (65 : 35) of S-(+) and R-(-) enantiomers, the naturally occurring isomeric ratio. Enantiomer-specific active sites on receptor proteins in the same or different cells are implicated.

Cognitive dietary restraint is associated with higher urinary cortisol excretion in healthy premenopausal women.

BACKGROUND: Cognitive dietary restraint, assessed by the Three-Factor Eating Questionnaire restraint subscale, is associated with subclinical menstrual cycle disturbances. This association may be mediated by stress-activated cortisol release. OBJECTIVE: We assessed whether 24-h urinary cortisol excretion differs between women with high and low restraint scores. DESIGN: Participants (aged 21.6+/-2.5 y; n = 62) with normal-length menstrual cycles and high (n = 33) or low (n = 29) restraint scores completed a questionnaire describing weight history, dietary practices, and exercise. Cortisol, calcium, and creatinine were measured in urine collected over 24 h on a day when all food and beverages were provided and measured. Previously, 3-d food records and anthropometric measurements were obtained. RESULTS: Age, height, weight, body mass index, and length of menstrual cycle were similar between groups. The reported amount of exercise was higher (3.4+/-1.7 compared with 2.2+/-1.8 h/wk; P<0.05) and energy intakes (assessed from 3-d and 24-h food records) were lower in the high- than in the low-restraint group. Ratios of urinary cortisol (nmol) to creatinine (mmol) were higher in the high-restraint than in the low-restraint group (42.9+/-12.9 compared with 36.3+/-8.9; P<0.05), whereas ratios of urinary calcium (mmol) to creatinine were lower (0.3+/-0.1 compared with 0.4+/-0.2; P<0.05) in the high-restraint group. Urinary cortisol was not associated with exercise, nutrient intakes, or anthropometric measurements. CONCLUSIONS: High dietary restraint scores are associated with urinary cortisol, a biological marker of stress, and high cortisol excretion may affect bone health. Our results suggest that further research is warranted to clarify these associations and to determine whether they persist over time.

Aspirin-sensitive asthma.

Aspirin intolerance is particularly common in asthmatic patients who additionally have chronic rhinitis and/or nasal polyps. These individuals differ in several respects from patients who experience urticaria and/or angioedema after aspirin administration, and differing mechanisms may be involved. Data regarding the latter are indirect and incomplete, but suggest that ASA-sensitive asthma is most likely to be related in some manner to the capacity of ASA to inhibit cyclooxygenases, enhanced lipoxygenase metabolism perhaps playing a crucial role. Current research employing ASA "desensitization" may help to elucidate these enigmas.

Elimination rate of 65Zn as a measure of food intake: a validation study in the mouse (Mus sp.).

We measured elimination of 65Zn in white mice (Mus musculus) using daily whole body counting. Thirteen male mice were randomly divided into three groups, each maintained at a different temperature. Each animal was labeled with 65Zn on day 0 and monitored over days 0-48 postinjection. Daily food intake and body masses of all the animals were measured. We evaluated the ability of derived components of the 65Zn elimination curves to predict food intake over different phases of the measurement period. Food intake was significantly different between temperature groups; temporal variation in food intake was not intercorrelated between groups. Whole body elimination of 65Zn involved a rapid decline over days 0-1, followed by a biexponential decline in counts over days 1-48. Components of the first phase of the biexponential elimination curve were not significantly related to food intake. The rate (k2) of isotope elimination in the second phase was significantly related to mean food intake over days 25-48, 13-24, and 37-48. Rate of turnover in the second phase of elimination, incorporating the variation in zinc body pool size (k2 x 1/N2), where N2 is the constant of the second phase of elimination, was the best predictor of food intake and accounted for 60% of the variability over days 37-48.

Sensitive quantitation of chromium-DNA adducts by inductively coupled plasma mass spectrometry with a direct injection high-efficiency nebulizer.

A novel method is described for the sensitive detection of chromium-DNA adducts. Chromium-DNA adducts were determined in 1 microgram of DNA from normal human lung fibroblasts exposed to sodium chromate using microscale flow injection analysis with a direct injection high-efficiency nebulizer and inductively coupled plasma mass spectrometry detection. The frequency of Cr-DNA adducts increased in a dose-dependent sigmoidal manner, indicating saturation and toxicity. The low detection limits (on the order of parts per trillion) allows the detection of as few as two Cr adducts per 10,000 bases, which, coupled with the small DNA sample requirement, makes this technique suitable for measuring metal-DNA adducts as biomarkers of exposure to toxic and carcinogenic metals such as Cr, in cultured cells, animals, and humans.

Driving experience and the risk of traffic accident among motorcyclists.

In a case-control study on the risk of traffic accidents among motorcyclists in Singapore, we demonstrated an inverse monotonic relationship between accident risk and driving experience. As compared to drivers with less that 1 yr of driving experience, the odds ratios (adjusted for race, age and frequency of riding) for those with driving experience of 1-4, 5-9 and 10 yr or more were 0.60, 0.50 and 0.36, respectively. We propose that intensive in-circuit training of learner motorcyclists should replace the conventional on-the-road training on the basis that the former serves to increase their driving experience without subjecting the learner motorcyclists to the risk of sustaining road accident.

Dietary restraint, exercise, and bone density in young women: are they related?

PURPOSE: Women with high scores for dietary restraint have been found to have higher 24-h urinary cortisol excretion and a higher prevalence of subclinical ovulatory disturbances, both of which may be risk factors for bone loss. The purpose of this study was to explore relationships between dietary restraint and bone health in regularly menstruating young women. METHODS: 62 women (age: 21.7 +/- 2.5 yr) had body composition and total body and lumbar spine bone mineral density (BMD) and content (BMC) assessed using dual-energy x-ray absorptiometry. Dietary restraint was assessed using the restraint subscale from the Three-Factor Eating Questionnaire: 29 women had low restraint (LR; restraint score 0--5), 33 had high restraint (HR; restraint score 13--21). Exercise (h x wk(-1)) was assessed by questionnaire on two occasions. RESULTS: LR and HR women were similar in age and body composition (fat mass = 15.0 +/- 4.7 kg, lean mass = 40.9 +/- 4.9 kg), but HR women exercised more (3.4 +/- 1.7 vs 2.2 +/- 1.8 h x wk(-1), P < 0.05). Exercise was correlated with BMD and BMC, and when it was included as a covariate, total body BMC was significantly lower in HR than LR women. In multiple regression analysis, weekly hours of exercise and restraint score were significant predictors of total body BMD and BMC. CONCLUSION: The observations of this cross-sectional study suggest that high levels of cognitive dietary restraint, or associated factors such as higher cortisol, may attenuate the positive effects of exercise on bone in young women.

Efficacy of feedback training in long-standing facial nerve paresis.

An efficacious treatment has not been available to patients with aberrant regeneration of the facial nerve as a result of Bell's palsy or after acoustic neuroma excision. This prospective controlled trial examines the efficacy of electromyographic feedback versus mirror feedback as treatment strategies for patients suffering from long-standing (18 months minimum) facial nerve paresis. Twenty-five patients were randomly assigned to electromyography with mirror feedback or mirror feedback alone. Seven rural patients who did not undergo treatment served as controls. At 0, 6, and 12 months, facial motor function was objectively quantified by linear measurement of facial movement, visual assessment of voluntary movement, and electrical measurement of facial nerve response to maximal stimulation. Statistically significant improvements were noted in both electromyography and mirror-feedback groups with respect to symmetry of voluntary movement (P less than .03) and linear measurement of facial expression (P less than .01). The positive results of this controlled trial demonstrate that feedback training in combination with a structured home rehabilitation program is a clinically efficacious treatment for patients with facial nerve paresis.

Somatosensory evoked potentials in acute spinal cord injury: prognostic value.

The somatosensory evoked potential is absent in patients with complete motor and sensory loss below the level of spinal cord injury. When spinal cord injury is incomplete, these alterations in potential may be elicited from stimulation of a nerve entering the cord below the level of injury. The presence of such potentials soon after injury, or their early return, and progressive normalization of the wave form are sensitive early indications of favorable prognosis. Indeed, recovery of the somatosensory evoked potentials frequently precedes major clinical improvement and may occur in advance of clinical recovery or posterior column function.

Effects of body mass and reproduction on the basal metabolic rate of brown long-eared bats (Plecotus auritus).

We measured basal metabolic rate (BMR) of nonreproductive and of breeding (pregnant and lactating) female brown long-eared bats (Plecotus auritus) to investigate the effects of intra- and interindividual variation in body mass and of reproduction on metabolism. The BMR of six nonreproductive females was measured between five and seven times at approximately 2-wk intervals over a period of 2.5 mo. There was a highly significant effect (P<0.001) of body mass on BMR of these nonreproductive females. The pooled within-individual scaling exponent (1.88) significantly exceeded the established mammalian interspecific exponent (0.75). In addition, we made single observations on 14 nonreproductive females to establish the effects of differences in mass between individuals. The mean BMR across all 14 individuals was 82 mW (+/-24 SD). There was a significant positive relationship between BMR and body mass across these individuals (r2=0.39), with a between-individual scaling exponent of 0.75. Inter- and intraindividual effects of mass on BMR were combined in a regression analysis that included mean body mass and deviation from mean mass on any given day as predictors. This regression model explained 55% of the variation in BMR. We made longitudinal measurements of BMR throughout reproduction and compared these with the predicted BMR of nonreproductive bats of the same body mass. Reproductive females exhibited temporal flexibility in BMR. BMR during pregnancy increased on a whole-animal basis but was significantly lower (by, on average, 15%) than BMR predicted for nonreproductive females of the same mass. Over a period of 1-75 d following birth, whole-animal BMR was greater than that during pregnancy, even though body mass declined after parturition. Hence, postbirth BMR was greater than the level predicted for nonreproductive females of the same mass. This study indicates that the scaling of BMR with body mass differs significantly within and between individuals and that there is a reduction of BMR in pregnancy and an elevation of BMR during lactation.

Effect of ammonia on nasal resistance in atopic and nonatopic subjects.

Nasal airway resistance (NAR) was assessed from the slope of pressure-glow curves obtained during normal nasal breathing. Volunteers were classified as atopic or nonatopic according to strict critera. 100 ppm NH3 was introduced into each nostril for periods ranging from 5 to 30 seconds with frequent NAR monitoring. A progressive increase in NAR responses was obtained with incremental NH3 exposure, but no significant difference was noted between the mean response of atopic and nonatopic subjects. Control exposures to compressed air under the same pressure generally produced only a small change in NAR, while aerosolized buffered saline increased NAR more than compressed air. The nasal response to NH3 was effectively inhibited by intranasal atropine administration but not by chlorpheniramine. The nasal response to NH3 was effectively inhibited by intranasal atropine administration but not by chlorpheniramine. The described procedure provides a safe and simple method for studying semiquantitatively the short-term effects of inhaled irritants on the nose.

Distribution and clearance of radioactive aerosol on the nasal mucosa.

The distribution and clearance of aerosolized radioactive technetium 99m pertechnate in physiologic buffered saline was analyzed in four human adult asymptomatic volunteers following delivery into one nostril in the same manner as for nasal challenge testing (i.e., 0.1 ml via a 251 DeVilbiss atomizer powered by a compressor delivering 0.10 +/- 0.01 gm/spray). For comparison, squeeze bottles and spray bottles from commercial sources, a 114 and a 127 DeVilbiss atomizer, and a pipette were employed. Lateral imagery via minicomputer processing was used to determine both distribution and clearance of the radiotracer. The counts after 1 minute were lower following pipette delivery than with the other devices. None yielded discernable , wide-spread distribution of aerosol throughout the nasal cavity. Following delivery from the 251 atomizer, mean clearance at 17 minutes was 60.0%. Similar clearance rates were obtained with the other spraying methods except for lower values with the squeeze bottle. Analysis of six hour clearance studies by linear regression showed a relatively rapid initial phase, which is probably due largely to mucociliary clearance, and a prolonged late phase related to the very slow disappearance of residual material located far anteriorly in the nose. Achieving good initial retention and rapid clearance of material deposited anteriorly in the nose are desirable attributes of devices employed for administering materials intranasally.

Blood diseases in old age.

There is an increased incidence of chronic disease in old age, and blood disorder is not uncommon. Some diseases are more frequent in the latter half of life, while others -- such as the hereditary disorders -- are rare and occur only in a mild degree. Diagnosis of blood disease is more difficult in the elderly because symptoms of anaemia such as weakness, shortness of breath and mental disorder are often attributed to old age.

Towards monitoring real-time cellular response using an integrated microfluidics-matrix assisted laser desorption ionisation/nanoelectrospray ionisation-ion mobility-mass spectrometry platform.

The combination of microfluidic cell trapping devices with ion mobility-mass spectrometry offers the potential for elucidating in real time the dynamic responses of small populations of cells to paracrine signals, changes in metabolite levels and delivery of drugs and toxins. Preliminary experiments examining peptides in methanol and recording the interactions of yeast and Jurkat cells with their superfusate have identified instrumental set-up and control parameters and online desalting procedures. Numerous initial experiments demonstrate and validate this new instrumental platform. Future outlooks and potential applications are addressed, specifically how this instrumentation may be used for fully automated systems biology studies of the significantly interdependent, dynamic internal workings of cellular metabolic and signalling pathways.