Publications by authors named "Catherine Cunningham"

7 Publications

  • Page 1 of 1

Callosal anisotropy predicts attentional network changes after parietal inhibitory stimulation.

Neuroimage 2021 02 13;226:117559. Epub 2020 Nov 13.

National Institute of Neurological Disorders and Stroke, Bethesda, USA.

Hemispatial neglect is thought to result from disruption of interhemispheric equilibrium. Right hemisphere lesions deactivate the right frontoparietal network and hyperactivate the left via release from interhemispheric inhibition. Support for this putative mechanism comes from neuropsychological evidence as well as transcranial magnetic stimulation (TMS) studies in healthy subjects, in whom right posterior parietal cortex (PPC) inhibition causes neglect-like, rightward, visuospatial bias. Concurrent TMS and fMRI after right PPC TMS show task-dependent changes but may fail to identify effects of stimulation in areas not directly activated by the specific task, complicating interpretations. We used resting-state functional connectivity (RSFC) after inhibitory TMS over the right PPC to examine changes in the networks underlying visuospatial attention and used diffusion-weighted imaging to measure the structural properties of relevant white matter pathways. In a crossover experiment in healthy individuals, we delivered continuous theta burst TMS to the right PPC and vertex as control condition. We hypothesized that PPC inhibitory stimulation would result in a rightward visuospatial bias, decrease frontoparietal RSFC, and increase the PPC RSFC with the attentional network in the left hemisphere. We also expected that individual differences in fractional anisotropy (FA) of the frontoparietal network and the callosal pathway between the PPCs would account for variability of the TMS-induced RSFC changes. As hypothesized, TMS over the right PPC caused a rightward shift in line bisection judgment and increased RSFC between the right PPC and the left superior temporal gyrus. This effect was inversely related to FA in the posterior corpus callosum. Local inhibition of the right PPC reshapes connectivity in the attentional network and depends significantly on interhemispheric connections.
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http://dx.doi.org/10.1016/j.neuroimage.2020.117559DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7885523PMC
February 2021

Prism Adaptation Modulates Connectivity of the Intraparietal Sulcus with Multiple Brain Networks.

Cereb Cortex 2020 07;30(9):4747-4758

Behavioral Neurology Unit, National Institute of Neurological Disorders and Stroke Bethesda, MD 20892, USA.

Prism adaptation (PA) alters spatial cognition according to the direction of visual displacement by temporarily modifying sensorimotor mapping. Right-shifting prisms (right PA) improve neglect of left visual field in patients, possibly by decreasing activity in the left hemisphere and increasing it in the right. Left PA shifts attention rightward in healthy individuals by an opposite mechanism. However, functional imaging studies of PA are inconsistent, perhaps because of differing activation tasks. We measured resting-state functional connectivity (RSFC) in healthy individuals before and after PA. When contrasted, right versus left PA decreased RSFC in the spatial navigation network defined by the right posterior parietal cortex (PPC), hippocampus, and cerebellum. Within-PA-direction comparisons showed that right PA increased RSFC in subregions of the PPCs and between the PPCs and the right middle frontal gyrus and left PA decreased RSFC between these regions. Both right and left PA decreased RSFC between the PPCs and bilateral temporal areas. In summary, right PA increases connectivity in the right frontoparietal network and left PA produces essentially opposite effects. Furthermore, right, compared with left, PA modulates RSFC in the right hemisphere navigation network.
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http://dx.doi.org/10.1093/cercor/bhaa032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526755PMC
July 2020

Local manganese chloride treatment accelerates fracture healing in a rat model.

J Orthop Res 2015 Jan 17;33(1):122-30. Epub 2014 Sep 17.

Department of Orthopaedics, Rutgers-New Jersey Medical School, 90 Bergen Street, Suite 7300, Newark, New Jersey, 07103.

This study investigated the effects of local delivery of manganese chloride (MnCl2), an insulin-mimetic compound, upon fracture healing using a rat femoral fracture model. Mechanical testing, histomorphometry, and immunohistochemistry were performed to assess early and late parameters of fracture healing. At 4 weeks post-fracture, maximum torque to failure was 70% higher (P<0.05) and maximum torsional rigidity increased 133% (P<0.05) in animals treated with 0.125 mg/kg MnCl2 compared to saline controls. Histological analysis of the fracture callus revealed percent new mineralized tissue was 17% higher (P<0.05) at day 10. Immunohistochemical analysis of the 0.125 mg/kg MnCl2 treated group, compared to saline controls, showed a 379% increase in the density of VEGF-C+ cells. In addition, compared to saline controls, the 0.125 mg/kg MnCl2 treated group showed a 233% and 150% increase in blood vessel density in the subperiosteal region at day 10 post-fracture as assessed by detection of PECAM and smooth muscle α actin, respectively. The results suggest that local MnCl2 treatment accelerates fracture healing by increasing mechanical parameters via a potential mechanism of amplified early angiogenesis leading to increased osteogenesis. Therefore, local administration of MnCl2 is a potential therapeutic adjunct for fracture healing.
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http://dx.doi.org/10.1002/jor.22733DOI Listing
January 2015

Local ZnCl2 accelerates fracture healing.

J Orthop Res 2014 Jun 26;32(6):834-41. Epub 2014 Feb 26.

Rutgers New Jersey Medical School, Department of Orthopaedics, 90 Bergen Street, Suite 7300, Newark, New Jersey, 07103.

This study evaluated the effect of local zinc chloride (ZnCl2 ), an insulin mimetic agent, upon the early and late parameters of fracture healing in rats using a standard femur fracture model. Mechanical testing, radiographic scoring, histomorphometry, qualitative histological scoring, PCNA immunohistochemistry, and local growth factor analysis were performed. Fractures treated with local ZnCl2 possessed significantly increased mechanical properties compared to controls at 4 weeks post fracture. The radiographic scoring analysis showed increased cortical bridging at 4 weeks in the 1.0 (p=0.0015) and 3.0 (p<0.0001) mg/kg ZnCl2 treated groups. Histomorphometry of the fracture callus at day 7 showed 177% increase (p=0.036) in percent cartilage and 133% increase (p=0.002) in percent mineralized tissue with local ZnCl2 treatment compared to controls. Qualitative histological scoring showed a 2.1× higher value at day 7 in the ZnCl2 treated group compared to control (p = 0.004). Cell proliferation and growth factors, VEGF and IGF-I, within fracture calluses treated with local ZnCl2 were increased at day 7. The results suggest local administration of ZnCl2 increases cell proliferation, causing increased growth factor production which yields improved chondrogenesis and endochondral ossification. Ultimately, these events lead to accelerated fracture healing as early as 4 weeks post fracture.
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http://dx.doi.org/10.1002/jor.22593DOI Listing
June 2014

Local vanadium release from a calcium sulfate carrier accelerates fracture healing.

J Orthop Res 2014 May 30;32(5):727-34. Epub 2013 Dec 30.

Department of Orthopaedics, Rutgers New Jersey Medical School, 90 Bergen Street, Suite 7300, Newark, New Jersey, 07103.

This study evaluated the efficacy of using calcium sulfate (CaSO4 ) as a carrier for intramedullary delivery of an organic vanadium salt, vanadyl acetylacetonate (VAC) after femoral fracture. VAC can act as an insulin-mimetic and can be used to accelerate fracture healing in rats. A heterogenous mixture of VAC and CaSO4 was delivered to the fracture site of BB Wistar rats, and mechanical testing, histomorphometry, micro-computed tomography (micro-CT) were performed to measure healing. At 4 weeks after fracture, maximum torque to failure, effective shear modulus, and effective shear stress were all significantly higher (p < 0.05) in rats treated with 0.25 mg/kg VAC-CaSO4 as compared to carrier control rats. Histomorphometry found a 71% increase in percent cartilage matrix (p < 0.05) and a 64% decrease in percent mineralized tissue (p < 0.05) at 2 weeks after fracture in rats treated with 0.25 mg/kg of VAC-CaSO4 . Micro-CT analyses at 4 weeks found a more organized callus structure and higher trending maximum connected z-ray. fraction for VAC-CaSO4 groups. Evaluation of radiographs and serial histological sections at 12 weeks did not show any evidence of ectopic bone formation. As compared to previous studies, CaSO4 was an effective carrier for reducing the dose of VAC required to accelerate femoral fracture healing in rats.
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http://dx.doi.org/10.1002/jor.22570DOI Listing
May 2014

Reversal of laryngotracheal separation in paediatric patients.

Int J Pediatr Otorhinolaryngol 2010 Nov;74(11):1251-3

Department of Paediatric Otolaryngology, Our Lady's Hospital for Sick Children, Drimnagh Road, Crumlin, Dublin 12, Ireland.

Objective: Laryngotracheal separation (LTS) is an effective and reliable definitive treatment for intractable aspiration. A major advantage of this treatment for intractable aspiration is its' potential reversibility. Should the underlying disorder improve, a reversal of the procedure may be attempted. This has been successfully achieved in the adult population. To our knowledge, no previous cases have been reported of successful reversal of LTS in children.

Methods: A retrospective review from 2003 to 2010 identified four cases of intractable aspiration treated with LTS in our department. Two of these patients displayed objective evidence of sufficient recovery of their underlying aspiration to consider reversal. Patient selection for reversal was dependent upon successful oral intake for 9 months along with videofluoroscopic evidence of normal or minimally impaired swallow.

Results: Two children who were successfully treated for intractable aspiration with LTS demonstrated objective evidence of recovery sufficient to attempt reversal. Both children underwent successful surgical reversal of LTS using a cricotracheal resection with end-to-end anastamosis, similar to that used in treatment of subglottic stenosis. Both children can now tolerate oral diet and their speech and language development is in line with their overall developmental level.

Conclusions: Laryngotracheal separation is an effective and reliable definitive treatment for intractable aspiration facilitating protection of the airway and allowing safe swallowing with unimpeded respiration, but with the major drawback of loss of phonation. To our knowledge, we document the first two cases of successful LTS reversal in children.
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http://dx.doi.org/10.1016/j.ijporl.2010.07.024DOI Listing
November 2010

Randomized study of the safety and efficacy of fish oil (omega-3 fatty acid) supplementation with dietary and exercise counseling for the treatment of antiretroviral therapy-associated hypertriglyceridemia.

Clin Infect Dis 2005 Nov 11;41(10):1498-504. Epub 2005 Oct 11.

Division of Infectious Diseases, University of North Carolina, Chapel Hill, NC 27599, USA.

Background: Omega-3 fatty acids (fish oils) reduce fasting serum triglyceride levels and cardiovascular disease risk in individuals without HIV infection. Whether omega-3 fatty acid supplementation can reduce hypertriglyceridemia associated with antiretroviral therapy is not known.

Methods: We conducted an open-label, randomized trial that enrolled 52 patients receiving > or =3 active antiretrovirals who had fasting triglyceride levels of >200 mg/dL and were randomized to receive nutritionist-administered dietary and exercise counseling with or without fish oil supplementation for 16 weeks.

Results: Patients assigned to receive fish oil experienced a 25% mean decline in fasting triglyceride levels at week 4 (95% CI, -34.6% to -15.7% change), compared with a 2.8% mean increase among patients assigned to receive counseling alone (95% CI, -17.5% to +23.1% change) (P=.007). By week 16, the mean reduction in triglyceride levels in the fish oil arm remained significant, at 19.5% (95% CI, -34.9% to -4.0% change), whereas the mean decrease in the diet and exercise only arm was 5.7% (95% CI, -24.6% to +13.2% change); however, the difference between study arms was no longer statistically significant (P=.12). Low-density lipoprotein cholesterol levels had increased by 15.6% (95% CI, +4.8% to +26.4% change) at week 4 and by 22.4% (95% CI, +7.91% to +36.8% change) at week 16 in the fish oil arm but did not change in the diet and exercise only group. Fish oil was well tolerated; only 1 patient experienced treatment-limiting toxicity. Patients assigned to receive fish oil experienced a 25% mean decline in fasting triglyceride levels at week 4 (95% CI, -34.6% to -15.7% change), compared with a 2.8% mean increase in patients assigned to receive counseling alone (95% CI, -17.5% to 23.1% change) (P=.007). By week 16, the mean reduction in triglyceride levels in the fish oil arm remained significant, at 19.5% (95% CI, -34.9% to -4.0% change), whereas the mean decrease in the diet and exercise only arm was 5.7% (95% CI, -24.6% to 13.2% change); however, the difference between study arms was no longer statistically significant (P=.12). Low-density lipoprotein cholesterol levels had increased by 15.6% (95% CI, 4.8%-26.4% change) at week 4 and by 22.4% (95% CI, 7.91%-36.8% change) at week 16 in the fish oil arm but did not change in the diet and exercise only group. Fish oil was well tolerated; only 1 patient experienced treatment-limiting toxicity.

Conclusions: Supplementation with omega-3 fatty acids in combination with dietary and exercise counseling was well tolerated and reduced fasting triglyceride levels in patients receiving antiretrovirals. To what extent the increase in low-density lipoprotein cholesterol levels observed in patients assigned this intervention is attributable to omega-3 fatty acid supplementation and whether this increase attenuates any benefit in lowering triglyceride levels is unclear. Given these results, further investigation of omega-3 fatty acid supplementation for the treatment of hypertriglyceridemia in HIV-infected patients is warranted.
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http://dx.doi.org/10.1086/497273DOI Listing
November 2005