Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Front Hum Neurosci ; 14: 191, 2020.
Article in English | MEDLINE | ID: mdl-32676015

ABSTRACT

Essential tremor (ET) is the most prevalent movement disorder in adults, and can often be medically refractory, requiring surgical intervention. MRI-guided focused ultrasound (MRgFUS) is a less invasive procedure that uses ultrasonic waves to induce lesions in the ventralis intermedius nucleus (VIM) to treat refractory ET. As with all procedures for treating ET, optimal targeting during MRgFUS is essential for efficacy and durability. Various studies have reported cases of tremor recurrence following MRgFUS and long-term outcome data is limited to 3-4 years. We present a tractography-based investigation on a case of DBS rescue for medically refractory ET that was treated with MRgFUS that was interrupted due to the development of dysarthria during the procedure. After initial improvement, her hand tremor started to recur within 6 months after treatment, and bilateral DBS was performed targeting the VIM 24 months after MRgFUS. DBS induced long-term tremor control with monopolar stimulation. Diffusion MRI tractography was used to reconstruct the dentatorubrothalamic (DRTT) and corticothalmic (CTT) tracts being modulated by the procedures to understand the variability in efficacy between MRgFUS and DBS in treating ET in our patient. By comparing the MRgFUS lesion and DBS volume of activated tissue (VAT), we found that the MRgFUS lesion was located ventromedially to the VAT, and was less than 10% of the size of the VAT. While the lesion encompassed the same proportion of DRTT streamlines, it encompassed fewer CTT streamlines than the VAT. Our findings indicate the need for further investigation of targeting the CTT when using neuromodulatory procedures to treat refractory ET for more permanent tremor relief.

2.
Proc Biol Sci ; 284(1867)2017 Nov 29.
Article in English | MEDLINE | ID: mdl-29167357

ABSTRACT

Teleost fishes evolved livebearing via egg retention 14 times. Matrotrophy has evolved within 12 of those lineages. By contrast, squamate reptiles evolved livebearing over 115 times, but only two to four of those lineages are known to have evolved matrotrophy. Is the discrepancy between these organisms in the probability of this transition caused by differences in their eggs? We show that the eggs of oviparous species in the superorder Atherinomorpha can acquire small organic molecules from their surrounding environment against a concentration gradient via mechanisms of active transport. Uptake rates were inhibited by competing radiolabelled amino acids against unlabelled versions of themselves. Transport was non-specific as uptake rates were similar for l-leucine and its biologically uncommon enantiomer d-leucine. Eggs are also capable of transporting larger microspheres across the membrane, but transport is inhibited at temperatures below 4°C, suggesting active transport occurs via pinocytosis. Conflict theory predicts that the ability of the egg to acquire maternal resources will facilitate the embryo-parent arms race that leads to the evolution of matrotrophy following the transition to livebearing. The shelled eggs of amniotes lack such access to maternal resources when retained in the evolution of viviparity.


Subject(s)
Adaptation, Biological , Biological Evolution , Cyprinodontiformes/physiology , Ovum/physiology , Viviparity, Nonmammalian , Amino Acids/metabolism , Animals , Female , Pinocytosis
3.
Nephrol Dial Transplant ; 32(9): 1549-1558, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-27789782

ABSTRACT

BACKGROUND: Incident hemodialysis patients may experience rapid weight loss in the first few months of starting dialysis. However, trends in weight changes over time and their associations with survival have not yet been characterized in this population. METHODS: In a large contemporary US cohort of 58 106 patients who initiated hemodialysis during 1 January 2007-31 December 2011 and survived the first year of dialysis, we observed trends in weight changes during the first year of treatment and then examined the association of post-dialysis weight changes with all-cause mortality. RESULTS: Patients' post-dialysis weights rapidly decreased and reached a nadir at the 5th month of dialysis with an average decline of 2% from baseline, whereas obese patients (body mass index ≥30 kg/m 2 ) did not reach a nadir and lost ∼3.8% of their weight by the 12th month. Compared with the reference group (-2 to 2% changes in weight), the death hazard ratios (HRs) of patients with -6 to -2% and greater than or equal to -6% weight loss during the first 5 months were 1.08 (95% confidence interval, 1.02-1.14) and 1.14 (1.07-1.22), respectively. Moreover, the death HRs with 2-6% and ≥6% weight gain during the 5th to 12th months were 0.91 (0.85-0.97) and 0.92 (0.86-0.99), respectively. CONCLUSIONS: In patients who survive the first year of hemodialysis, a decline in post-dialysis weight is observed and reaches a nadir at the 5th month. An incrementally larger weight loss during the first 12 months is associated with higher death risk, whereas weight gain is associated with greater survival during the 5th to 12th month but not in the first 5 months of dialysis therapy.


Subject(s)
Body Weight , Kidney Failure, Chronic/mortality , Obesity/physiopathology , Renal Dialysis/mortality , Body Mass Index , Cohort Studies , Female , Humans , Kidney Failure, Chronic/therapy , Male , Middle Aged , Survival Rate , Weight Gain , Weight Loss
4.
Tob Regul Sci ; 2(2): 153-165, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27517061

ABSTRACT

OBJECTIVE: Restricting tobacco marketing is a key element in the US Food and Drug Administration's (FDA) public health framework for regulating tobacco. Given the dearth of empirical data on direct marketing, the objective of this study was to assess the reach and impact of promotions on sales through snuff websites. METHODS: Nine brands of snuff, representing more than 90% of market share, were monitored for content of coupons, sweepstakes, contests, and other promotions on their respective websites. Monthly sales data and website traffic for the 9 brands, corresponding to the 48-month period of January 2011 through December 2014, were obtained from proprietary sources. A time-series analysis, based on the autoregressive, integrated, moving average (ARIMA) method, was employed for testing the relationships among sales, website visits, and promotions. RESULTS: Website traffic increased substantially during the promotion periods for most brands. Time-series analyses, however, revealed that promotion periods for 5 of 7 brands did not significantly correlate with monthly snuff sales. CONCLUSIONS: The success in attracting tobacco consumers to website promotions demonstrates the marketing reach of snuff manufacturers. This form of direct marketing should be monitored by the FDA given evidence of adolescents' exposure to cigarette brand websites.

SELECTION OF CITATIONS
SEARCH DETAIL
...