Role of locus coeruleus heme oxygenase-carbon monoxide-cGMP pathway during hypothermic response to restraint

Central heme oxigenase-carbon monoxide (HO-CO) pathway has been shown to play a pyretic role in the thermoregulatory response to restraint. However, the specific site in the central nervous system where CO may act modulating this response remains unclear. LC is rich not only in sGC but also in heme oxygenase (HO; the enzyme that catalyses the metabolism of heme to CO, along with biliverdin and free iron). Therefore, the possible role of the HO-CO-cGMP pathway in the restraint-induced-hypothermia by LC neurons was investigated. Body temperature dropped about 0.7 degrees C during restraint. ZnDPBG (a HO inhibitor; 5 nmol, intra-LC) prevented the hypothermic response during restraint. Conversely, induction of the HO pathway in the LC with heme-lysinate (7.6 nmol, intra-LC) intensified the hypothermic response to restraint, and this effect was prevented by pretreatment with ODQ (a sGC inhibitor; given intracerebroventricularly, 1.3 nmol). Taken together, these data suggest that CO in the LC produced by the HO pathway and acting via cGMP is implicated in thermal responses to restraint. (C) 2007 Elsevier Inc. All rights reserved.

Evaluation of several protocols for the application of ultrasound during the removal of cast intraradicular posts cemented with zinc phosphate cement

To evaluate several protocols for the application of ultrasound during removal of cast posts with varying core configurations cemented with zinc phosphate. Sixty maxillary canines were distributed into three groups (n = 20): group 1 - core with 5 mm diameter/height and post diameter of 1.3 mm; groups 2 and 3 - core with the same diameter as the post (1.3 mm) and heights of 5 mm and 3 mm, respectively. Posts/cores were cemented using a standard technique with zinc phosphate cement. Each group was divided into two subgroups according to the ultrasonic vibration mode: point vibration - ultrasonic vibration applied to the core surface for 5 s, on each face totalling 25 s; alternate vibration - intermittent application of ultrasonic vibration for 10 s to the labial and lingual surfaces, 10 s to the mesial and distal surfaces and 5 s to the incisal surface, totalling 25 s. The specimens were submitted to the tensile test using an Instron machine (1 mm min(-1)) and results were analysed by anova and t-test. The failure type was also analysed. Statistical analysis showed significant differences between groups relating to the core preparations (P < 0.05). The lowest mean values of traction force were obtained for group 3 (46.1 +/- 7.7 N), followed by group 2 (89.0 +/- 2.7 N) and group 1 (160.4 +/- 7.5 N). Regarding ultrasonic vibration, the lowest mean was observed with alternate vibration (81.1 +/- 10.1 N), which was significantly lower than the point vibration (115.9 +/- 9.5 N) (P < 0.05). Cohesive failure occurred in all cases. A reduction in core diameter/height and intermittent ultrasonic application improved the removal of cast posts cemented with zinc phosphate.

Masticatory muscle activity during maximum voluntary clench in different research diagnostic criteria for temporomandibular disorders (RDC/TMD) groups

The research diagnostic criteria for temporomandibular disorders (RDC/TMD) are used for the classification of patients with temporomandibular disorders (TMD). Surface electromyography of the right and left masseter and temporalis muscles was performed during Maximum teeth clenching in 103 TMD patients subdivided according to the RDC/TMD into 3 non-overlapping groups: (a) 25 myogenous; (b) 61 arthrogenous; and (c) 17 psycogenous patients. Thirty-two control subjects matched for sex and age were also measured. During clenching, standardized total muscle activities (electromyographic potentials over time) significantly differed: 131.7 mu V/mu V s % in the normal subjects, 117.6 mu V/mu V s % in the myogenous patients, 105.3 mu V/mu V s % in the arthrogenous patients, 88.7 mu V/mu V s % in the psycogenous patients (p < 0.001, analysis of covariance). Symmetry in the temporalis muscles was larger in normal subjects (86.3%) and in myogenous patients (84.9%) than in arthrogenous (82.7%), and psycogenous patients (80.5%) (p=0.041). No differences were found for masseter muscle symmetry and torque coefficient (p>0.05). Surface electromyography of the masticatory muscles allowed an objective discrimination among different RDC/TMD subgroups. This evaluation could assist conventional clinical assessments. (C) 2007 Elsevier Ltd. All rights reserved.

Temperature variation at the external root surface during 980-nm diode laser irradiation in the root canal

Objective: To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters. Methods: The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n = 30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n = 10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n = S): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers. Results: The groups irradiated in the continuous mode (CM) presented the highest values (11.82 +/- 5.78), regardless of the canals were dry or not, which were statistically different (p < 0.01) from those obtained with 100 Hz (6.22 +/- 3.64) and 1000 Hz (6.00 +/- 3.36), which presented no statistical difference between them (p > 0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15 +/- 5.14), followed by 3.0 W (7.88 +/- 3.92) and 1.5 W (4.02 +/- 2.16), differing between them (p < 0.01). The cervical third of the root presented the highest temperature rises (9.68 +/- 5.80), followed by the middle (7.66 +/- 4.87) and apical (6.70 +/- 4.23), with statistical difference among them (p < 0.01). After 30 s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C. Conclusions: Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20 s, can safely be used in endodontic treatment, irrespective of the presence of humidity. (C) 2008 Elsevier Ltd. All rights reserved.

Temporal relationship between the auditory brainstem response and focal responses of auditory nerve root and cochlear nucleus during development in the tammar wallaby (Macropus eugenii)

Thirty-two pouch-young tammar wallabies were used to discover the generators of the auditory brainstem response (ABR) during development by the use of simultaneous ABR and focal brainstem recordings. A click response from the auditory nerve root (ANR) in the wallaby was recorded from postnatal day (PND) 101, when no central auditory station was functional, and coincided with the ABR, a simple positive wave. The response of the cochlear nucleus (CN) was detected from PND 110, when the ABR had developed 1 positive and 1 negative peak. The dominant component of the focal ANR response, the N-1 wave, coincided with the first half of the ABR P wave, and that of the focal CN response, the N-1 wave, coincided with the later two thirds. In older animals, the ANR response coincided with the ABR's N-1, wave, while the CN response coincided with the ABR's P-2, N-2 and P-3 waves, with its contribution to the ABR P-2 dominant. The protracted development of the marsupial auditory system which facilitated these correlations makes the tammar wallaby a particularly suitable model. Copyright (C) 2001 S. Karger AG, Basel.

Growth hormone (GH)/GH receptor expression and GH-mediated effects during early bovine embryogenesis

Pituitary growth hormone (GH) stimulates postnatal growth and metabolism. The role of CH and its receptor (GHR) during prenatal development, however, is still controversial. As shown by reverse transcription polymerase chain reaction (RT-PCR), bovine in vitro fertilization embryos synthesized the transcript of GHR from Day 2 of embryonic life onwards. Real time RT-PCR revealed that synthesis of GHR mRNA was increased 5.9-fold in 6-day-old embryos compared with 2-day-old embryos. Using in situ hybridization, the mRNA encoding GHR was predominantly localized to the inner cell mass of blastocysts. The GHR protein was first visualized 3 days after fertilization. GH-specific transcripts were first detected in embryos on Day 8 of in vitro culture. As shown by transmission electron microscopy, GH treatment resulted in elimination of glycogen storage in 6- to 8-day-old embryos and an increase in exocytosis of lipid vesicles. These results suggest that a functional GHR able to modulate carbohydrate and lipid metabolism is synthesized during preimplantation development of the bovine embryo and that this GHR may be subject to activation by embryonic GH after Day 8.

Age changes in personality traits and their heritabilities during the adult years: evidence from Australian Twin Registry samples

Short versions of four Eysenck personality scales had been included in questionnaires given to several adult samples from the Australian Twin Registry, comprising altogether some 5400 pairs. Means and regressions with age are compared for three samples at average ages of 23, 37, and 61 years, and for two samples of retested individuals, one tested twice at average ages of 29 and 37 years, and one tested three times at average ages of 45, 56, and 62 years, For both males and females the trends for Psychoticism (P), Extraversion (E), and Neuroticism (N) were generally downward with age, and for Lie (L), upward. However, in the longitudinal sample between ages 56 and 62 the trends for P, E, and I stopped or reversed, although N continued downward. Heritabilities were reasonably stable across age for P, E, and N, and the effects of shared environments negligible, but L showed some influence of shared environment as well as genes in all but the oldest age group. (C) 2001 Elsevier Science Ltd. All rights reserved.

Microdialysis and response during regional chemotherapy by isolated limb infusion of melphalan for limb malignancies

This study sought to use a microdialysis technique to relate clinical and biochemical responses to the time course of melphalan concentrations in the subcutaneous interstitial space and in tumour tissue (melanoma, malignant fibrous histiocytoma, Merkel cell tumour and osteosarcoma) in patients undergoing regional chemotherapy by Isolated Limb Infusion (ILI). 19 patients undergoing ILI for treatment of various limb malignancies were monitored for intra-operative melphalan concentrations in plasma and, using microdialysis, in subcutaneous and tumour tissues. Peak and mean concentrations of melphalan were significantly higher in plasma than in subcutaneous or tumour microdialysate. There was no significant difference between drug peak and mean concentrations in interstitial and tumour tissue, indicating that there was no preferential uptake of melphalan into the tumours. The time course of melphalan in the microdialysate could be described by a pharmacokinetic model which assumed melphalan distributed from the plasma into the interstitial space. The model also accounted for the vascular dispersion of melphalan in the limb. Tumour response in the whole group to treatment was partial response: 53.8% (n = 7); complete response: 33.3% (n = 5); no responses 6.7% (n = 1). There was a significant association between tumour response and melphalan concentrations measured over time in subcutaneous microdialysate (P < 0.01). No significant relationship existed between the severity of toxic reactions in the limb or peak plasma creatine phosphokinase levels and peak melphalan microdialysate or plasma concentrations. It is concluded that microdialysis is a technique well suited for measuring concentrations of cytotoxic drug during ILI. The possibility of predicting actual concentrations of cytotoxic drug in the limb during ILI using our model opens an opportunity for improved drug dose calculation. The combination of predicting tissue concentrations and monitoring in microdialysate of subcutaneous tissue could help optimise ILI with regard to post-operative limb morbidity and tumour response. (C) 2001 Cancer Research Campaign http:,//www.bjcancer.com.

Biophysical characterization of interactions involving importin-alpha during nuclear import

Proteins containing the classical nuclear localization sequences (NLSs) are imported into the nucleus by the importin-alpha/beta heterodimer. Importin-alpha contains the NLS binding site, whereas importin-beta mediates the translocation through the nuclear pore. We characterized the interactions involving importin-alpha during nuclear import using a combination of biophysical techniques (biosensor, crystallography, sedimentation equilibrium, electrophoresis, and circular dichroism). Importin-alpha is shown to exist in a monomeric autoinhibited state (association with NLSs undetectable by biosensor). Association with importin-beta (stoichiometry, 1:1; K-D = 1.1 x 10(-8) m) increases the affinity for NLSs; the importin-alpha/beta complex binds representative monopartite NLS (simian virus 40 large T-antigen) and bipartite NLS (nucleoplasmin) with affinities (K-D = 3.5 x 10(-8) m and 4.8 x 10(-8) m, respectively) comparable with those of a truncated importin-alpha lacking the autoinhibitory domain (T-antigen NLS, K-D = 1.7 x 10(-8) m; nucleoplasmin NLS, K-D = 1.4 x 10(-8) m). The autoinhibitory domain (as a separate peptide) binds the truncated importin-alpha, and the crystal structure of the complex resembles the structure of full-length importin-alpha. Our results support the model of regulation of nuclear import mediated by the intrasteric autoregulatory sequence of importin-alpha and provide a quantitative description of the binding and regulatory steps during nuclear import.

Energy expenditure during 2nd week of an ultra-endurance run around Australia

Purpose: For ultra-endurance athletes, whose energy expenditure is likely to be at the extremes of human tolerance for sustained periods of time, there is increased concern regarding meeting energy needs. Due to the lack of data outlining the energy requirements of such athletes, it is possible that those participating in ultra-endurance exercise are compromising performance, as well as health, as a result of inadequate nutrition and energy intake. To provide insight into this dilemma, we have presented a case study of a 37-yr-old ultra-marathon runner as he runs around the coast of Australia. Methods: Total energy expenditure was measured over a 2-wk period using the doubly labeled water technique. Results: The average total energy expenditure of the case subject was 6321 kcal.d(-1). Based on the expected accuracy and precision of the doubly labeled water technique the subject's total energy expenditure might range between 6095 and 6550 kcal.d(-1). The subject's average daily water turnover was 6.083 L over the 14-d period and might range between 5.9 L and 6.3 L.d(-1). Conclusions: This information will provide a guide to the energy requirements of ultra-endurance running and enable athletes, nutritionists, and coaches to optimize performance without compromising the health of the participant.

Flaviviruses isolated from mosquitoes collected during the first recorded outbreak of Japanese encephalitis virus on Cape York Peninsula, Australia

In response to an outbreak of Japanese encephalitis (JE) virus on Cape York Peninsula, Australia, in 1998, mosquitoes were collected using CO2 and octenol-baited Centers for Disease Control and Prevention light traps. A total of 35,235 adult mosquitoes, comprising 31 species, were processed for virus isolation. No isolates of JE virus were recovered from these mosquitoes. However, 18 isolates of Kokobera virus, another flavivirus were obtained from Culex annulirostris. Twelve isolates were from western Cape York (minimum infection rate (MIR) of 0.61: 1,000 mosquitoes) and 6 were from the Northern Peninsula Area (MIR of 1.0:1,000). Potential explanations for the failure to detect JE virus in mosquitoes collected from Cape York Peninsula include the timing of collections, the presence of alternative bloodmeal hosts, differences in pig husbandry, asynchronous porcine seroconversion, and the presence of other flaviviruses.

Molluscan stable isotope temperature estimates of the southwestern Ross Sea during the early oligocene and early miocene, CRP-2/2A and CRP-3, Victoria Land Basin, Antarctica

Stable isotope analyses of marine bivalve growth increment samples have been used to estimate early Oligocene (29.4 - 31.2) Ma and early Miocene (24.0 Ma) seafloor palaeotemperatures from the southwestern continental margin of the Ross Sea. Measured δ18O values average +2.5‰ in the early Miocene and range between +1.26 to +3.24‰ in the early Oligocene. The results show that palaeoceanographic conditions in McMurdo Sound during the mid-Cenozoic were significantly different from those of today. The minimum estimated spring through late summer seasonal temperature range was 3°C during the early Miocene and between 1 and 5°C during the early Oligocene. This compares to the equivalent modern day range of

Blink startle modulation during anticipation of pleasant and unpleasant stimuli

The present research investigated blink startle modulation during the anticipation of pleasant, unpleasant, or neutral pictures. In Experiment 1 (N = 18), participants were presented with three different tone-picture pairings. Tones differed in pitch and were followed by pleasant, neutral or unpleasant pictures. Acoustic blink reflexes were elicited during some tones and during stimulus free intervals. Blink facilitation during tones that preceded pleasant and unpleasant pictures was larger than during the tone that preceded neutral pictures. Experiment 2 (N = 10) assessed whether this difference was due to a difference in the presentation frequency of the three conditions. No difference in blink facilitation between the conditions was found when pictures of flowers and mushrooms replaced the pleasant and unpleasant pictures, indicating that picture content was instrumental in causing the differential blink facilitation in Experiment 1. The results from Experiment 1 seem to indicate that startle modulation during the anticipation of pictorial material reflects the interest in or the arousal associated with the pictures rather than picture valence.

Fluid shifts resulting from exercise in rats as detected by bioelectrical impedance

Purpose: This study was designed to investigate the immediate effect of exercise intensity and duration on body fluid volumes in rats throughout a 3-wk exercise program. Methods: Changes in the extracellular water (ECW) and total body water (TBW) volumes of rats were measured preexercise and postexercise using multiple frequency bioelectrical impedance analysis. Groups of rats were exercised at two intensities (6 m.min(-1) and 12 m.min(-1)) for two exercise times (60 min and 90 min) 5 d.wk(-1) during a 3-wk period. Changes in plasma electrolytes, glucose, and lactate resulting from the exercise were also measured on 3 d of each week. Results: Each group of animals showed significant losses in ECW and TBW as a direct result of daily exercise. The magnitude of fluid loss was directly related to the intensity of the exercise, bur not to exercise duration; although the magnitude of daily fluid loss at the higher intensity exercise (12 m.min(-1)) decreased as the study progressed, possibly indicating a training effect. Conclusion: At low-intensity exercise, there is a small bur significant loss in both TBW and ECW fluids, and the magnitude of these losses does not change throughout a 3-wk exercise program. At moderate levels of exercise intensity, there is a greater loss of both TBW and ECW fluids. However, the magnitudes of these losses decrease significantly during the 3-wk exercise program, thus demonstrating a training effect.