228 research outputs found
The Value of a Chest CT in the Evaluation of a Newly Detected Brain Tumor
OBJECTIVE: To create a care pathway for patients with a newly detected brain tumor, by examining common diagnostic pathways for patients diagnosed with a primary brain tumor or a central nervous system metastasis.
MATERIALS AND METHODS: All patients diagnosed atMGH between 1/1/95 and 12/31/97 with a primary brain tumor or a central nervous system metastasis were studied. Only patients who displayed one or two brain lesions and presented to the MGH emergency ward or transferred in from another emergency ward were included in the study. Clinical characteristics, use and results of radiological testing, and final diagnostic procedures were evaluated.
RESULTS: Forty-eight patients were selected for the study. The most common ancillary test performed was a chest x-ray; 97.9% of the patients received a chest x-ray, while only 18.8% received a chest CT. None of the chest CT examinations showed a diagnostically significant different from the chest x-ray. Other ancillary scanning was done infrequently.
DISCUSSION: A relatively small proportion of patients with a newly detected brain lesion received any type of ancillary testing beyond a chest x-ray. A chest x-ray appeared to change the biopsy site from the brain to another site in about 50% of the cases. Not enough chest CT examinations were done to determine their effectiveness. However, the resuhs seem to indicate that the preliminary diagnosis of the admitting physician is not necessarily based upon the results of a chest x-ray or other ancillary testing
Brainstem ischemic syndrome in juvenile NF2.
Objective: A new case of brainstem ischemic necrosis in a young woman with de novo neurofibromatosis type 2 (NF2) is reported, and given notable similarities to 7 prior cases of brainstem stroke in the literature, features defining a possible syndrome were sought.
Methods: Case review including detailed clinical assessment, neuroimaging analysis, genetic testing, and brain biopsy, followed by a multicase analysis.
Results: Brainstem ischemia in juvenile NF2 typically occurs in teenagers without previously known NF2 as an acute, monophasic presentation with restricted diffusion in the midbrain or pons following a recent hypoperfusion event, normal vascular imaging, obvious intracranial imaging features of NF2, typical inactivating
Conclusions: Brainstem ischemia in juvenile NF2 is a rare syndrome of unclear etiology, possibly reflecting an unknown underlying vascular abnormality; a digenic effect is not excluded
Wage Distribution Impacts of Higher Education Faculty Unionization
The literature on the effects of unions on the distribution of wages at the macroeconomic and inter-industry levels has given little attention to the effects at the firm level. At the same time, research on collective bargaining impacts in higher education has focused on the overall wage level rather than on the distribution of salaries. Using panel data on individual faculty members, we find faculty unionization to be associated with a significant flattening of the wage distribution across academic disciplines. This has implications for why faculty might choose to unionize, even in the absence of an overall wage premium
Erratum to "A watershed model of individual differences in fluid intelligence" [Neuropsychologia 91 (2016) 186-198].
The publisher regrets that due to an error the full text of Appendix A
was missing in the original publication. The missing text is included
below.
The publisher would like to apologise for any inconvenience caused
Central spindle self-organization and cytokinesis in artificially activated sea urchin eggs
Author Posting. © Marine Biological Laboratory, 2016. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 230, no.2 (2016): 85-95.The ability of microtubules of the mitotic apparatus
to control the positioning and initiation of the cleavage
furrow during cytokinesis was first established from
studies on early echinoderm embryos. However, the identity
of the microtubule population that imparts cytokinetic signaling
is unclear. The two main––and not necessarily mutually
exclusive–– candidates are the central spindle and the
astral rays. In the present study, we examined cytokinesis in
ammonia-activated sea urchin eggs, which lack paternally
derived centrosomes and undergo mitosis mediated by unusual
anastral, bipolar mini-spindles. Live cell imaging and
immunolabeling for microtubules and the centralspindlin
constituent and kinesin-related protein, MKLP1, demonstrated
that furrowing in ammonia-activated eggs was associated
with aligned arrays of centralspindlin-linked, opposed
bundles of antiparallel microtubules. These autonomous, zipper-
like arrays were not associated with a mitotic apparatus,
but did possess characteristics similar to the central spindle
region of control, fertilized embryos. Our results highlight the
self-organizing nature of the central spindle region and its
ability to induce cytokinesis-like furrowing, even in the absence
of a complete mitotic apparatus.This research was
supported by student/faculty summer research grants from
the Dickinson College Research and Development Committee
to JHH; Laura and Arthur Colwin Summer Research
Fellowships from the MBL to JHH and CBS; a National
Science Foundation Major Research Instrumentation grant
to JHH (MRI-0320606); and a NSF collaborative research
grant to JHH (MCB-1412688) and to CBS (MCB-
1412734)
Wage Distribution Impacts of Higher Education Faculty Unionization
The literature on the effects of unions on the distribution of wages at the macroeconomic and inter-industry levels has given little attention to the effects at the firm level. At the same time, research on collective bargaining impacts in higher education has focused on the overall wage level rather than on the distribution of salaries. Using panel data on individual faculty members, we find faculty unionization to be associated with a significant flattening of the wage distribution across academic disciplines. This has implications for why faculty might choose to unionize, even in the absence of an overall wage premium
Distinct aspects of frontal lobe structure mediate age-related differences in fluid intelligence and multitasking.
Ageing is characterized by declines on a variety of cognitive measures. These declines are often attributed to a general, unitary underlying cause, such as a reduction in executive function owing to atrophy of the prefrontal cortex. However, age-related changes are likely multifactorial, and the relationship between neural changes and cognitive measures is not well-understood. Here we address this in a large (N=567), population-based sample drawn from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) data. We relate fluid intelligence and multitasking to multiple brain measures, including grey matter in various prefrontal regions and white matter integrity connecting those regions. We show that multitasking and fluid intelligence are separable cognitive abilities, with differential sensitivities to age, which are mediated by distinct neural subsystems that show different prediction in older versus younger individuals. These results suggest that prefrontal ageing is a manifold process demanding multifaceted models of neurocognitive ageing
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