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Papers by Anneli du Plessis

Padilla J, Jenkins NT, Vieira-Potter VJ, Laughlin MH. Divergent phenotype of rat thoracic and abd... more Padilla J, Jenkins NT, Vieira-Potter VJ, Laughlin MH. Divergent phenotype of rat thoracic and abdominal perivascular adipose tissues. Am cular adipose tissue (PVAT) is implicated as a source of proatherogenic cytokines. Phenotypic differences in local PVAT depots may contribute to differences in disease susceptibility among arteries and even regions within an artery. It has been proposed that PVAT around the abdominal and thoracic aorta shares characteristics of white and brown adipose tissue (BAT), respectively; however, a detailed comparison of the phenotype of these PVAT depots has not been performed. Using young and older adult rats, we compared the phenotype of PVATs surrounding the abdominal and thoracic aorta to each other and also to epididymal white and subscapular BAT. Compared with young rats, older rats exhibited greater percent body fat (34.5 Ϯ 3.1 vs. 10.4 Ϯ 0.9%), total cholesterol (112.2 Ϯ 7.5 vs. 58.7 Ϯ 6.3 mg/dl), HOMA-insulin resistance (1.7 Ϯ 0.1 vs. 0.9 Ϯ 0.1 a.u.), as well as reduced ACh-induced relaxation of the aorta (maximal relaxation: 54 Ϯ 10 vs. 77 Ϯ 6%) (all P Ͻ 0.05). Expression of inflammatory genes and markers of immune cell infiltration were greater in abdominal PVAT than in thoracic PVAT, and overall, abdominal and thoracic PVATs resembled the phenotype of white adipose tissue (WAT) and BAT, respectively. Histology and electron microscopy indicated structural similarity between visceral WAT and abdominal PVAT and between BAT and thoracic PVAT. Our data provide evidence that abdominal PVAT is more inflamed than thoracic PVAT, a difference that was by and large independent of sedentary aging. Phenotypic differences in PVAT between regions of the aorta may be relevant in light of the evidence in large animals and humans that the abdominal aorta is more vulnerable to atherosclerosis than the thoracic aorta. brown fat; obesity; perivascular fat; vascular function; white fat Address for reprint requests and other correspondence: J. Padilla,

Schmorl's nodes are the result of herniations of the nucleus pulposus into the adjacent vertebral... more Schmorl's nodes are the result of herniations of the nucleus pulposus into the adjacent vertebral body and are commonly identified in both clinical and archaeological contexts. The current study aims to identify aspects of vertebral shape that correlate with Schmorl's nodes. Two-dimensional statistical shape analysis was performed on digital images of the lower thoracic spine (T10-T12) of adult skeletons from the late medieval skeletal assemblages from Fishergate House, York, St. Mary Graces and East Smithfield Black Death cemeteries, London, and postmedieval Chelsea Old Church, London. Schmorl's nodes were scored on the basis of their location, depth, and size. Results indicate that there is a correlation between the shape of the pos-Additional Supporting Information may be found in the online version of this article.

A LLOGENEIC FOETAL rat pancreatic transplantation (FRPT) or islet transplantation, an attractive ... more A LLOGENEIC FOETAL rat pancreatic transplantation (FRPT) or islet transplantation, an attractive tool for the study of islet and endocrine development/ morphology and maturation in situ, has been shown in isolated studies to reverse experimentally induced diabetes provided rejection can be adequately suppressed. This has been very difficult to date. Rejection after FRPT, especially in the case of transplantation across a major strain histocompatibility barrier, is very rapid with the destruction of the grafts within a few days of implantation. Combination cyclosporine (CyA) based immunosuppressive therapy regimens, at lower doses to minimize the side effects of steroids and CyA, possibly hold the promise for the future in this field of transplantation. Mycophenolate Mofetil (MMF) inhibits the de novo purine synthesis pathway by blocking the enzyme inosine monophosphate dehydrogenase. As T and B lymphocytes require this pathway of purine synthesis to proliferate when activated, they are selectively suppressed by the drug. MMF combined with cyclosporine acts synergistically and could be of great benefit in long-term immunosuppression of foetal or islet allografts.

Neuropathological changes associated with Alzheimer's disease (AD) such as amyloid plaques, cereb... more Neuropathological changes associated with Alzheimer's disease (AD) such as amyloid plaques, cerebral amyloid angiopathy, and related pathologies are reproduced in APP23 transgenic mice overexpressing amyloid precursor protein (APP) with the Swedish mutation. Magnetic resonance angiography (MRA) was applied to probe, in vivo, the cerebral arterial hemodynamics of these mice. Flow voids were detected at the internal carotid artery of 11-month-old APP23 mice. At the age of 20 months, additional flow disturbances were observed in large arteries at the circle of Willis. Vascular corrosion casts obtained from the same mice revealed that vessel elimination, deformation, or both had taken place at the sites where flow voids were detected by MRA. The detailed three-dimensional architecture of the vasculature visible in the casts assisted the identification of smaller vessels most likely formed as substitution or anastomosis within the circle of Willis. Angiograms and corrosion casts from nontransgenic, age-matched mice manifested no major abnormalities in the cerebrovascular arterial flow pattern. Because no transgene overexpression has been found in the cerebrovasculature of APP23 mice and no deposits of amyloid-␤(A␤) were observed in large arteries in the region of the circle of Willis, the present results suggest that soluble A␤ may exert deleterious effects on the vasculature. Our findings support the idea that cerebral circulatory abnormalities evolving progressively could contribute to AD pathogenesis. The study also shows the power of MRA to identify changes of vascular function in genetically engineered mice. MRA as a noninvasive technique could be applied to test new therapeutic concepts in animal models of AD and in humans.