Rats subjected to chronic-intermittent hypoxia have increased density of noradrenergic terminals in the trigeminal sensory and motor nuclei

Rodents subjected to chronic intermittent hypoxia (CIH) are used to investigate the mechanisms underlying the consequences of the obstructive sleep apnea (OSA) syndrome. Following CIH, rats have an increased density of noradrenergic terminals in the hypoglossal motor nucleus which innervates lingual muscles that protect the upper airway from collapse in OSA patients. Here, we investigated whether such an increase also occurs in other brainstem nuclei. Six pairs of male Sprague-Dawley rats were exposed to CIH or sham treatment for 10 h/day for 35 days, with O₂ level oscillating between 24% and 7% every 3 min. Brainstem sections were immunohistochemically processed for dopamine-β-hydroxylase, a marker for norepinephrine. Noradrenergic terminal varicosities were counted in the center of the trigeminal motor nucleus (Mo5) and the interpolar part of the spinal trigeminal sensory nucleus (Sp5). In the Mo5, noradrenergic varicosities tended to be 9% more numerous in CIH- than sham-treated rats, and in the Sp5 they were 18% more numerous in CIH rats (184 ± 9 vs. 156 ± 8 per 100 × 100 μm counting box; p = 0.03, n = 18 section pairs).These data suggest that CIH elicits sprouting of noradrenergic terminals in multiple motor and sensory regions of the lower brainstem. This may alter motor and cardiorespiratory outputs and the transmission of cardiorespiratory and motor reflexes in CIH rats and, by implication, in OSA patients.     

Knowledge of Evidence‐Based Urinary Catheter Care Practice Recommendations Among Healthcare Workers in Nursing Homes

OBJECTIVES: To assess the knowledge of recommended urinary catheter care practices among nursing home (NH) healthcare workers (HCWs) in southeast Michigan. DESIGN: Self‐administered survey. SETTING: Seven NHs in southeast Michigan. PARTICIPANTS: HCWs. MEASUREMENTS: The survey included questions about respondent characteristics and knowledge about indications, care, and personal hygiene pertaining to urinary catheters. The association between knowledge measures and occupation (nurses vs aides) was assessed using generalized estimating equations. RESULTS: Three hundred fifty‐six of 440 HCWs (81%) responded. More than 90% of HCWs were aware of measures such as cleaning around the catheter daily, glove use, and hand hygiene with catheter manipulation. They were less aware of research‐proven recommendations of not disconnecting the catheter from its bag (59% nurses, 30% aides, P<.001), not routinely irrigating the catheter (48% nurses, 8% aides, P<.001), and hand hygiene after casual contact (60% nurses, 69% aides, P=.07). HCWs were also unaware of recommendations regarding alcohol‐based hand rub (27% nurses and 32% aides with correct responses, P=.38). HCWs reported informal (e.g., nurse supervisors) and formal (in‐services) sources of knowledge about catheter care. CONCLUSION: Significant discrepancies remain between research‐proven recommendations pertaining to urinary catheter care and HCWs' knowledge. Nurses and aides differ in their knowledge of recommendations against harmful practices, such as disconnecting the catheter from the bag and routinely irrigating catheters. Further research should focus on strategies to enhance dissemination of proven infection control practices in NHs.     

Surgical management of primary and metastatic sarcoma of the mobile spine

OBJECT: Sarcomas of the spine are a challenging problem due to their frequent and extensive involvement of multiple spinal segments and high recurrence rates. Gross-total resection to negative margins, with preservation of neurological function and palliation of pain, is the surgical goal and may be achieved using either intralesional resection or en bloc excision. The authors report outcomes of surgery for primary and metastatic sarcomas of the mobile spine in a large patient series. METHODS: A retrospective review of patients undergoing resection for sarcomas of the mobile spine between 1993 and 2005 was undertaken. Sarcomas were classified by histology study results and as either primary or metastatic. Details of the surgical approach, levels of involvement, and operative complications were recorded. Outcome measures included neurological function, palliation of pain, local recurrence, and overall survival. RESULTS: Eighty patients underwent 110 resections of either primary or metastatic sarcomas of the mobile spine. Twenty-nine lesions were primary sarcomas (36%) and 51 were metastatic sarcomas (64%). Intralesional resections were performed in 98 surgeries (89%) and en bloc resections were performed in 12 (11%). Median survival from surgery for all patients was 20.6 months. Median survival for patients with a primary sarcoma of the spine was 40.2 months and was 17.3 months for patients with a metastatic sarcoma. Predictors of improved survival included a chondrosarcoma histological type and a better preoperative functional status, whereas osteosarcoma and a high-grade tumor were negative influences on survival. Multivariate analysis showed that only a high-grade tumor was an independent predictor of shorter overall survival. American Spinal Injury Association scale grades were maintained or improved in 97% of patients postoperatively, and there was a significant decrease in pain scores postoperatively. No significant differences in survival or local recurrence rates between intralesional or en bloc resections for either primary or metastatic spine sarcomas were found. CONCLUSIONS: Surgery for primary or metastatic sarcoma of the spine is associated with an improvement in neurological function and palliation of pain. The results of this study show a significant difference in patient survival for primary versus metastatic spine sarcomas. The results do not show a statistically significant benefit in survival or local recurrence rates for en bloc versus intralesional resections for either metastatic or primary sarcomas of the spine, but this may be due to the small number of patients undergoing en bloc resections.     

Head movements of children in MEG: quantification, effects on source estimation, and compensation

Head movements during magnetoencephalography (MEG) recordings may lead to inaccurate localization of brain activity. This can be particularly problematic for studies with children. We quantified head movements in 8- to 12-year-old children performing a cognitive task and examined how the movements affected source estimation. Each child was presented auditory word stimuli in five 4-min runs. The mean change in the MEG sensor locations during the experiment ranged from 3 to 26mm across subjects. The variation in the head position was largest in the up-down direction. The mean localization error in equivalent current dipole (ECD) simulations was 12mm for runs with the most head movement, with the frontal cortex appearing to be most prone to errors due to head movements. In addition, we examined the effect of head movements on two types of source estimates, ECDs and minimum-norm estimates (MNE), for an auditory evoked response. Application of a recently introduced signal space separation (SSS) method to compensate for the head movements was found to increase the goodness-of-fit of the ECDs, reduce the spatial confidence intervals of the ECDs, and enhance the peak amplitude in the MNE. These results are indicative of the SSS method being able to compensate for the spatial smoothing of the signals caused by head movements. Overall, the results suggest that MEG source estimates are relatively robust against head movements in children, and that confounds due to head movements can be successfully dealt with in MEG studies of developmental cognition.     

Range of movements of lower limb joints in cross-legged sitting posture

Cross-legged sitting posture is integral to activities of daily living in Eastern and Asian cultures. This posture has not been studied or defined in any significant detail from an orthopedic view point. The movements of right lower limb joints were measured in cross-legged sitting posture in 44 volunteers from the Indian population with no prior history of problems related to the knee or hip joint. Flexion at the hip joint ranged from 82 degrees to 100 degrees , with a mean of 91 degrees . Abduction at the hip joint ranged from 19 degrees to 57 degrees , with a mean of 39 degrees . The external rotation ranged from 42 degrees to 58 degrees , with a mean of 49 degrees . Flexion at the knee ranged from 126 degrees to 142 degrees , with a mean of 135 degrees .Equinus at the ankle ranged from 17 degrees to 34 degrees , with a mean of 29 degrees . The resultant data would be useful in understanding kinematics of the knee and hip in the healthy and post-total joint arthroplasty population. The data could be used for design features of prosthetic joints, surgical technique, and rehabilitation protocols. Such data have not been available hitherto in any relevant published literature.