Misleading high tobramycin plasma concentrations can be caused by skin contamination of fingerprick blood following inhalation of nebulized tobramycin (TOBI (R)) - A short report

We observed unexpected high plasma concentrations of tobrarriycin (48.5 and 28.1 mg/L) in fingerprick blood samples after the nebulization of tobramycin solution for inhalation (tobramycin 300 mg/5 mL, TOBI(R)) by 2 young children aged 3 years. To investigate whether dermal contamination could be the source of error, 3 adult volunteers were present during another nebulization by a third child (age 2 years). The volunteers had exposure to tobramycin by handling the nebulizer or the nebule and also by inhalation from holding the child and being in close proximity while TOBI(R) was being administered. Five blood samples by fingerprick and 2 by venipuncture were collected and assayed for tobramycin concentration. On each occasion the site was swabbed with alcohol wipes to mimic standard patient sampling methods. One site was resampled after cleaning of hands with 2% chlorhexidine gluconate and water. Tobramycin concentrations from venipuncture 1-2 hours after nebulization were all < 0.2 mg/L except for 1 result of 1.2 mg/L. The tobramycin concentrations from fingerpricks before hand washing varied between 6.8 and 172 mg/L, and after hand washing between 0.3 and 17.6 mg/L. Contamination of fingers with tobramycin is likely to have caused the error in the 2 initial cases and did cause misleadingly elevated levels in the adult volunteers. We caution that therapeutic drug monitoring of nebulized tobramycin should not be done by fingerprick sampling, and care should be taken to avoid contamination of the venipuncture site.

Delayed traveling ionospheric disturbances, especially in equatorial regions, following geomagnetic activity

For the Western-Pacific region spread-F has been found to occur with delays after geomagnetic activity (GA) ranging from 5 to 10 days as station groups are considered from low midlatitudes to equatorial regions. The statistical (superposed-epoch) analyses also indicate that at the equator the spread-F, and therefore associated medium-scale traveling ionospheric disturbances (MS-TIDs) occur with additional delays around 16, 22 and 28 days representing a 6-day modulation of the delay period. These results are compared with similar delays, including the modulation, for D-region enhanced hydroxyl emission (Shefov, 1969). It is proposed that this similarity may be explained by MS-TIDs influencing both the F and D regions as they travel. Long delays of over 20 days are also found near the equator for airglow-measured MS-TIDs (Sobral et al., 1997). These are recorded infrequently and have equatorward motions, while normally eastward motions are measured at the equator. Also in midlatitudes D-region absorption events have been shown (statistically) to have similar long delays after GA. It is suggested that atmospheric gravity waves and associated MS-TIDs may be generated by some of the precipitations responsible for the absorption. The recording of the delayed spread-F events depends on the GA being well below the average levels around sunset on the nights of recording. This implies that lower upper-atmosphere neutral particle densities are necessary.

The development of psychological changes following whiplash injury

Psychological distress is a feature of chronic whiplash-associated disorders, but little is known of psychological changes from soon after injury to either recovery or symptom persistence. This study prospectively measured psychological distress (General Health Questionnaire 28 GHQ-28). fear of movement/re-injury (TAMPA Scale of Kinesphobia, TSK), acute post-traumatic stress (Impact of Events Scale, IES) and general health and well being (Short Form 36, SF-36) in 76 whiplash subjects within I month of injury and then 2, 3 and 6 months post-injury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (< 8), mild pain and disability (10-28) or moderate/severe pain and disability (> 30). All whiplash groups demonstrated psychological distress (GHQ-28, SF-36) to some extent at 1 month post-injury. Scores of the recovered group and those with persistent mild symptoms returned to levels regarded as normal by 2 months post-injury, parallelling a decrease in reported pain and disability. Scores on both these tests remained above threshold levels in those with ongoing moderate/severe symptoms. The moderate/severe and mild groups showed elevated TSK scores at 1 month post-injury. TSK scores decreased by 2 months in the group with residual mild symptoms and by 6 months in those with persistent moderate/severe symptoms. Elevated IES scores, indicative of a moderate post-traumatic stress reaction, were unique to the group with moderate/severe symptoms. The results of this study demonstrated that all those experiencing whiplash injury display initial psychological distress that decreased in those whose symptoms subside. Whiplash participants who reported persistent moderate/severe symptoms at 6 months continue to be psychologically distressed and are also characterised by a moderate post-traumatic stress reaction. (C) 2003 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Improved physical performance in older adults undertaking a short-term programme of high-velocity resistance training

Background: The age-related loss of muscle power in older adults is greater than that of muscle strength and is associated with a decline in physical performance. Objective: To investigate the effects of a short-term high-velocity varied resistance training programme on physical performance in healthy community-dwelling adults aged 60-80 years. Methods: Subjects undertook exercise (EX; n = 15) or maintained customary activity (controls, CON; n = 10) for 8 weeks. The EX group trained 2 days/week using machine weights for three sets of eight repetitions at 35, 55, and 75% of their one-repetition maximum (the maximal weight that an individual can lift once with acceptable form) for seven upper- and lower-body exercises using explosive concentric movements. Results: Fourteen EX and 10 CON subjects completed the study. Dynamic muscle strength significantly increased (p = 0.001) in the EX group for all exercises (from 21.4 +/- 9.6 to 82.0 +/- 59.2%, mean +/- SD) following training, as did knee extension power (p < 0.01). Significant improvement occurred for the EX group in the floor rise to standing (10.4 &PLUSMN; 11.5%, p = 0.004), usual 6-metre walk (6.6 &PLUSMN; 8.2%, p = 0.010), repeated chair rise (10.4 &PLUSMN; 15.6%, p = 0.013), and lift and reach (25.6 &PLUSMN; 12.1%, p = 0.002) performance tasks but not in the CON group. Conclusions: Progressive resistance training that incorporates rapid rate-of-force development movements may be safely undertaken in healthy older adults and results in significant gains in muscle strength, muscle power, and physical performance. Such improvements could prolong functional independence and improve the quality of life. Copyright (C) 2005 S. Karger AG, Basel.

Treating dysarthria following traumatic brain injury: Investigating the benefits of commencing treatment during post-traumatic amnesia in two participants

Primary objective: The aims of this preliminary study were to explore the suitability for and benefits of commencing dysarthria treatment for people with traumatic brain injury (TBI) while in post-traumatic amnesia ( PTA). It was hypothesized that behaviours in PTA don't preclude participation and dysarthria characteristics would improve post-treatment. Research design: A series of comprehensive case analyses. Methods and procedures: Two participants with severe TBI received dysarthria treatment focused on motor speech deficits until emergence from PTA. A checklist of neurobehavioural sequelae of TBI was rated during therapy and perceptual and motor speech assessments were administered before and after therapy. Main outcomes and results: Results revealed that certain behaviours affected the quality of therapy but didn't preclude the provision of therapy. Treatment resulted in physiological improvements in some speech sub-systems for both participants, with varying functional speech outcomes. Conclusions: These findings suggest that dysarthria treatment can begin and provide short-term benefits to speech production during the late stages of PTA post-TBI.

Mitochondrial dysmorphology in the neuroepithelium of rat embryos following a single dose of maternal hyperthermia during gestation

Hyperthermia is teratogenic to human and animal embryos and induces mainly anomalies of the nervous system. However, the teratogenic mechanism is poorly understood. Mammalian embryos are known to switch from anaerobic to aerobic metabolism around the time of neural tube closure. This critical event might be sensitive to hyperthermia. The objective of the present study was to evaluate the ultrastructural changes of the mitochondria of the neuroepithelium (NE) of rat embryos following maternal exposure to hyperthermia. Pregnant rats were heat stressed for an hour on gestation day (GD) 9 and embryos were examined by electron microscopy on GD 10. NE presented extensive apoptosis. Intercellular junctions were weakened and copious cellular debris projected into the ventricle. The mitochondria were of diverse size and shape. Most of them were swollen and had short cristae and electron dense matrix. Hydropic changes were also observed in numerous mitochondria. Lipid-laden mitochondria were found in the apical portions of neuroblasts. The mesenchyme (ME) of heat-treated embryos showed paucity of cells and only as frequent apoptosis as the controls. Their mitochondria also showed changes similar to those of the NE. Additionally extensive lipid accumulation was observed in and in the vicinity of mitochondria, often surrounded by short strands of endoplasmic reticulum. Whereas mitochondrial pathology was associated with profound apoptosis in the NE, growth restriction and lipid accumulation accompanied mitochondrial changes in the ME. The results of this study indicate that the embryonic response to maternal heat shock is tissue-specific and morphologically distinct in this species.

Short report: Lack of sex effect on the pharmacokinetics of primaquine

The pharmacokinetics of primaquine have been well defined in male volunteers, but there is little data on the disposition of the drug in women. We compared the kinetics of primaquine in nine male and nine female healthy Australian volunteers after the administration of a single oral dose (30 mg base) of primaquine. No statistical differences were observed in the following kinetic parameters of primaquine between men and women, respectively: maximum plasma concentration (93 +/- 26 and 115 +/- 38 ng/mL; 95% confidence interval [CI] of the mean difference: -55 to 10 ng/mL; P = 0.16), area under the curve (1.1 +/- 0.5 and 1.2 +/- 0.4 mu g.h/mL; 95% CI: -0.6 to 0.3 mu g.h/mL; P = 0.54), and clearance (0.34 +/- 0.12 and 0.39 +/- 0.14 L/h/kg; 95% CI: -0.17 to 0.08 L/h/kg; P = 0.46). The clinical relevance of such findings would suggest that sex does not have to be taken into account as a factor when prescribing primaquine for radical cure or terminal prophylaxis of Plasmodium vivax malaria.

Predictors of emotional well-being following a 'false positive' breast cancer screening result

Using a short-term longitudinal design, and consistent with a stress and coping perspective, this study examined the main and stress-buffering effects of social support and coping on emotional well-being following a 'false positive' breast cancer screening result. Immediately prior to obtaining results of follow-up assessment, 178 women completed measures of emotional well-being, stress appraisal, coping strategies and social support. Six weeks later, 85 women found to be cancer free completed a measure of well-being. Hierarchical regression analyses were used to examine the effects of social support and coping on well-being after controlling for initial well-being and stress appraisal. Consistent with predictions, avoidant coping was associated with higher levels of emotional well-being and social support was found to have a stress buffering effect on well-being. Active-cognitive coping strategies had a stress-buffering effect on well-being. Findings suggest that social support and coping do influence emotional well-being following recall for follow-up assessment of a 'false positive' breast cancer screening result.