Relationships between cranial base synchondroses and craniofacial development: a review

Abstract: Synchondrosis is defined as the development of a union between two bones by the formation of either hyaline cartilage or fibro-cartilage. This paper reviews the relationship between cranial base synchondroses and craniofacial development. The cranial base synchondroses are important growth centers of the craniofacial skeleton. Their abnormalities lead to numerous growth and developmental conditions in the craniofacial region. In dentofacial orthopedics, mechanical forces are commonly applied to cranial bones for growth modification to treat such conditions. Molecular biology and genetics provide tools to investigate the molecular mechanisms, genes and transcription factors responsible for synchondrosis and craniofacial development.published_or_final_versio

Die behoefte aan ’n wyer artikel 2(3) van die Wet op Testamente 7 van 1953 (soos gewysig): ’n Kritiese beskouing

Uit teks: Die Hoogste Hof van Appél se uitspraak in Bekker v Naude en Andere 2003(5) SA 173 (HHA) het die posisie aangaande die toepassing van artikel 2(3) van die Wet op Testamente 7 van 1953 (soos gewysig) duidelik uiteengesit en alle onsekerheid uit die weg geruim

Immune reconstitution inflammatory syndrome in children

Paradoxical deterioration due to immune reconstitution inflammatory syndrome (IRIS) occurs in up to 21% of children initiating antiretroviral therapy. Mycobacterial diseases are the most common, with BCG-vaccine adenitis predominating in infants and Mycobacterium tuberculosis (TB) in older children. The difficulty of diagnosing TB in HIV-infected children and the increasing risk of drug-resistant TB complicate the diagnosis and  management of both paradoxical IRIS and post-antiretroviral therapy TB. History and clinical assessment remain key strategies in the management of these infants and children. There are no prospective studies investigating diagnostic criteria and therapeutic strategies in children

MOLD-SHAPED, NANOFIBER SCAFFOLD-BASED CARTILAGE ENGINEERING USING HUMAN MESENCHYMAL STEM CELLS AND BIOREACTOR

Background Mesenchymal stem cell (MSC)-based tissue engineering is a promising future alternative to autologous cartilage grafting. This study evaluates the potential of using MSCs, seeded into electrospun, biodegradable polymeric nanofibrous scaffolds, to engineer cartilage with defined dimensions and shape, similar to grafts used for subcutaneous implantation in plastic and reconstructive surgery. Materials and methods Human bone marrow derived MSCs seeded onto nanofibrous scaffolds and placed in custom-designed molds were cultured for up to 42 days in bioreactors. Chondrogenesis was induced with either transforming growth factor-β1 (TGF-β1) alone or in combination with insulin-like growth factor-I (IGF-I). Results Constructs exhibited hyaline cartilage histology with desired thickness and shape as well as favorable tissue integrity and shape retention, suggesting the presence of elastic tissue. Time-dependent increase in cartilage matrix gene expression was seen in both types of culture; at Day 42, TGF-β1/IGF-I treated cultures showed higher collagen type II and aggrecan expression. Both culture conditions showed significant time-dependent increase in sulfated glycosaminoglycan and hydroxyproline contents. TGF-β1/IGF-I treated samples were significantly stiffer; with equilibrium compressive Young’s modulus values reaching 17 kPa by Day 42. Conclusions The successful ex vivo development of geometrically defined cartilaginous construct using customized molding suggests the potential of cell-based cartilage tissue for reconstructive surgery

Abacavir pharmacokinetics in African children living with HIV: A pooled analysis describing the effects of age, malnutrition and common concomitant medications

AIMS: Abacavir is part of WHO-recommended regimens to treat HIV in children under 15 years of age. In a pooled analysis across four studies, we describe abacavir population pharmacokinetics to investigate the influence of age, concomitant medications, malnutrition and formulation. METHODS: A total of 230 HIV-infected African children were included, with median (range) age of 2.1 (0.1-12.8) years and weight of 9.8 (2.5-30.0) kg. The population pharmacokinetics of abacavir was described using nonlinear mixed-effects modelling. RESULTS: Abacavir pharmacokinetics was best described by a two-compartment model with first-order elimination, and absorption described by transit compartments. Clearance was predicted around 54% of its mature value at birth and 90% at 10 months. The estimated typical clearance at steady state was 10.7 L/h in a child weighing 9.8 kg co-treated with lopinavir/ritonavir, and was 12% higher in children receiving efavirenz. During co-administration of rifampicin-based antituberculosis treatment and super-boosted lopinavir in a 1:1 ratio with ritonavir, abacavir exposure decreased by 29.4%. Malnourished children living with HIV had higher abacavir exposure initially, but this effect waned with nutritional rehabilitation. An additional 18.4% reduction in clearance after the first abacavir dose was described, suggesting induction of clearance with time on lopinavir/ritonavir-based therapy. Finally, absorption of the fixed dose combination tablet was 24% slower than the abacavir liquid formulation. CONCLUSION: In this pooled analysis we found that children on lopinavir/ritonavir or efavirenz had similar abacavir exposures, while concomitant TB treatment and super-boosted lopinavir gave significantly reduced abacavir concentrations

Graphene on Ir(111): Physisorption with chemical modulation

The nonlocal van der Waals density functional (vdW-DF) approach is applied to calculate the binding of graphene to Ir(111). The precise agreement of the calculated mean height h = 3.41 Å ; of the C atoms with their mean height h = (3.38 ± 0.04) Å ; as measured by the X-ray standing wave (XSW) technique provides a benchmark for the applicability of the non-local functional. We find bonding of graphene to Ir(111) to be due to the van der Waals interaction with an antibonding average contribution from chemical interaction. Despite its globally repulsive character, in certain areas of the large graphene moiré unit cell charge accumulation between Ir substrate and graphene C atoms is observed, signaling a weak covalent bond formation

The Lingering Environmental Impact of Repressive Governance: The Environmental Legacy of the Apartheid Era for the New South Africa

This article aims to explore the historical link between contemporary environmental problems and the environmental, economic and political policies of the apartheid government. The analysis draws on an examination of the detrimental environmental impacts of the apartheid era and how international isolation impacted on governmental environmental management in the country, before turning attention to the way in which the ANC government has managed the South African natural and human environments in the period after 1994. The article shows that despite many important new developments since 1994, that there are high levels of continuity between the environmental management practices of the old and the new regimes. This state of affairs negatively impacts on the ability of the ANC government to provide every South African citizen with the clean and safe environment guaranteed to all within the 1996 Bill of Rights.This article also appeared unchanged as a chapter in the following edited collection: Jan Oosthoek and Barry K. Gills (eds), _The Globalization of Environmental Crisis_ (Abingdon: Routledge, 2008), pp. 109-120

A full privacy-preserving distributed batch-based certificate-less aggregate signature authentication scheme for healthcare wearable wireless medical sensor networks (HWMSNs)

The dynamic connectivity and functionality of sensors has revolutionized remote monitoring applications thanks to the combination of IoT and wireless sensor networks (WSNs). Wearable wireless medical sensor nodes allow continuous monitoring by amassing physiological data, which is very useful in healthcare applications. These text data are then sent to doctors via IoT devices so they can make an accurate diagnosis as soon as possible. However, the transmission of medical text data is extremely vulnerable to security and privacy assaults due to the open nature of the underlying communication medium. Therefore, a certificate-less aggregation-based signature system has been proposed as a solution to the issue by using elliptic curve public key cryptography (ECC) which allows for a highly effective technique. The cost of computing has been reduced by 93% due to the incorporation of aggregation technology. The communication cost is 400 bits which is a significant reduction when compared with its counterparts. The results of the security analysis show that the scheme is robust against forging, tampering, and man-in-the-middle attacks. The primary innovation is that the time required for signature verification can be reduced by using point addition and aggregation. In addition, it does away with the reliance on a centralized medical server in order to do verification. By taking a distributed approach, it is able to fully preserve user privacy, proving its superiority