An ultrastructural study of the development of the chicken perineurial sheath

Three phases of perineurial development were recognised in the chicken sciatic nerve: (1) an early primitive phase during which the embryonic perineurium appeared to organise from the surrounding mesenchyme; (2) an intermediate phase of differentiation with the formation of a multilayered cellular network around the Schwann cell-axon complexes, and (3) a final phase of maturation during which the perineurial sheath showed features correlating with those of a functional barrier. Our observations support a mesenchymal origin for the perineurium rather than a schwannian derivation with clear separation of these 2 cell populations during all stages of development. Although the embryonic perineurial cells initially showed a fibroblast-like appearance, distinctive features of perineurial differentiation were present as early as 5 1/4 days (d) (Hamburger and Hamilton stage 28 embryo). Perineurial differentiation appeared to be intimately associated with developmental events in the Schwann cell-axon complexes, particularly during the period of most active Schwann cell proliferation. It is proposed that factors released by the Schwann cell-axon complexes during this period may be responsible for perineurial differentiation and organisation from the surrounding mesenchyme. The presence of endoneurial blood vessels following the appearance of perineurial basal lamina at 17 d (stage 43) suggested the emergence of a perineurial barrier. A perineurial architecture and cytological fine structure comparable to that of the adult animal was, however, only observed in the 10 d-old-chick.Articl

An in vitro assessment of the effect of Athrixia phylicoides DC. aqueous extract on glucose metabolism

Athrixia phylicoides DC. is an aromatic shrub indigenous to the eastern parts of Southern Africa. Indigenous communities brew "bush tea" from dried twigs and leaves of A. phylicoides, which is consumed as a beverage and used for its medicinal properties. Plant polyphenols have been shown to be beneficial to Type 2 diabetes mellitus (T2D) and obesity. Aqueous extracts of the plant have been shown to be rich in polyphenols, in particular phenolic acids, which may enhance glucose uptake and metabolism. The aim of this study was to determine the phenolic composition of a hot water A. phylicoides extract and assess its in vitro effect on cellular glucose utilisation. The most abundant phenolic compounds in the extract were 6-hydroxyluteolin-7-O-glucoside, chlorogenic acid, protocatechuic acid, a di-caffeoylquinic acid and a methoxy-flavonol derivative. The extract increased glucose uptake in C2C12, Chang and 3T3-L1 cells, respectively. Intracellular glucose was utilised by both oxidation (C2C12 myocytes and Chang cells; p < 0.01 and p < 0.05, respectively) and by increased glycogen storage (Chang cells; p < 0.05). No cytotoxicity was observed in Chang cells at the concentrations tested. The effects of the extract were not dose-dependent. A. phylicoides aqueous extract stimulated in vitro glucose uptake and metabolism, suggesting that consumption of this phenolic-rich extract could potentially ameliorate metabolic disorders related to obesity and T2D. © 2012 Elsevier GmbH. All rights reserved

Carotid stenosis and carotid plaque analysis relevant to carotid endarterectomy and stent-assisted angioplasty

The primary objective of this cadaveric study was to review the morphological variations of the anatomy of the human carotid artery bifurcation relevant to carotid endarterectomy (CEA) and carotid artery stent-supported angioplasty (CSSA). We quantify carotid bifurcation plaque morphology. Results showed that the angle of deviation at the origin of the internal carotid artery (ICA), in relation to the common carotid artery (CCA), measured a mean of 21.8 degrees with a range from seven to 45 degrees. This anatomical finding is important for the interventionalist concerned with insertion of a carotid stent. The angle of the ICA origin may be an independent risk factor for early atherosclerotic changes at the ICA bulb. Carotid bifurcation plaque was observed in a small, random cohort of seven out of 13 cadavers, and contributed to a mean stenosis of 15.2% (range 5.0-34.8%). Plaque morphology (n = 7) showed haemorrhage (29%), superficial thrombosis (57%), calcification (71%), areas of focal necrosis (71%), neovascularisation (14%) and infiltrates (29%). Ulcerations were not detected. Although four out of 13 patients (31%) died of a cerebrovascular accident, the cause of cerebral apoplexy was thought not to be associated with the carotid bifurcation pathology. 'Re-boring' of occluding plaque, as in CEA, offers potential volumetric anatomical advantage over CSSA within the carotid bifurcation and bulb. In conclusion, precise and applied knowledge of carotid bifurcation anatomy is critical to reduce technical complications during CEA or CSSA. This information may reduce potential dangers of iatrogenic thrombo-embolism and ensuing neurologic deficits. Patients with low-grade carotid stenosis, evidence of focal plaque necrosis, are at risk of spontaneous plaque cap rupture, distal thrombo-embolism and stroke.Revie

A polyphenol-enriched fraction of Cyclopia intermedia decreases lipid content in 3T3-L1 adipocytes and reduces body weight gain of obese db/db mice.

Extracts of . Cyclopia species, indigenous South African fynbos plants used for the production of honeybush tea, have potential as anti-obesity nutraceutical ingredients. Previously, we demonstrated that aqueous extracts of . C. maculata and . C. subternata exhibited anti-obesity effects in 3T3-L1 adipocytes. In this study, we further explored these anti-obesity effects of . C. maculata and . C. subternata as well as . C. intermedia for the first time. Extracts were prepared using a 40% methanol-water mixture (40% MeOH) in order to enhance the polyphenolic content of the extracts. Moreover, these extracts were separated into aqueous and organic fractions using liquid-liquid partitioning with . n-butanol and water to further enrich the polyphenol content of the organic fractions. Extracts of all three . Cyclopia species decreased the lipid content in 3T3-L1 adipocytes, although differences in bioactivity of their aqueous and organic fractions were observed. The organic fraction of . C. intermedia was further investigated. This fraction dose-dependently decreased the lipid content in 3T3-L1 adipocytes without affecting cell viability, while increasing mRNA expression of . HSL (1.57-fold, P. &lt;. 0.05), . SIRT1 (1.5-fold, P. =0.07), . UCP3 (1.5-fold, P. &lt;. 0.05) and . PPAR&gamma; (1.29-fold, P. &lt;. 0.05). Daily treatment of obese db/db mice with 351.5. mg/kg bodyweight of the organic . C. intermedia fraction for 28. days decreased bodyweight gain by 21% (P. &lt;. 0.05) without any effect on food or water consumption. The organic fraction was enriched in phenolic content relative to the extract with neoponcirin, a flavanone not previously identified in . Cyclopia species, mangiferin, isomangiferin and hesperidin comprising 17.37% of the organic fraction of . C. intermedia compared to 4.96% of its large scale prepared 40% MeOH extract. Their specific roles as anti-obesity agents in these models needs to be studied to guide product development

Differential effects of anticoagulants on tumor development of mouse cancer cell lines B16, K1735 and CT26 in lung

Cancer progression is facilitated by blood coagulation. Anticoagulants, such as Hirudin and low molecular weight heparins (LMWHs), reduce metastasis mainly by inhibition of thrombin formation and L- and P-selectin-mediated cell-cell adhesion. It is unknown whether the effects are dependent on cancer cell type. The effects of anticoagulants on tumor development of K1735 and B16 melanoma cells and CT26 colon cancer cells were investigated in mouse lung. Tumor load was determined noninvasively each week up to day 21 in all experiments using bioluminescence imaging. Effects of anticoagulants on tumor development of the three cell lines were correlated with the fibrin/fibrinogen content in the tumors, expression of tissue factor (TF), protease activated receptor (PAR)-1 and -4 and CD24, a ligand of L- and P-selectins. Hirudin inhibited tumor development of B16 cells in lungs completely but did not affect tumor growth of K1735 and CT26 cells. Low molecular weight heparin did not have an effect on K1735 melanoma tumor growth either. TF and PAR-4 expression was similar in the three cell lines. PAR-1 and CD24 were hardly expressed by K1735, whereas CT26 cells expressed low levels and B16 high levels of PAR-1 and CD24. Fibrin content of the tumors was not affected by LMWH. It is concluded that effects of anticoagulants are dependent on cancer cell type and are correlated with their CD24 and PAR-1 expressio