Computed tomography of the human developing anterior skull base

Abstract The ossification of the anterior skull base, especially the lamina cribrosa, has been studied by computed tomography and histopathology. Sixteen human fetuses, (referred to our laboratory for pathological examination after spontaneous abortion between 18 and 32 weeks of gestation) and three infants, (1, 2 and 6 years of age, respectively) were examined. The cartilaginous preformation of the anterior skull base creates a ‘pseudo-defect’ on CT in the coronal plane, even with ultra thin sections and high resolution CT. By the age of 6 years of life this ‘artefact’ is no longer, as the present ossification of the lamina cribrosa is, by that time, complete

Oesophageal Perforation: A diagnostic and therapeutic challenge in a resource limited setting. A report of three cases

Oesophageal perforation is a condition associated with a high mortality. Its management is still controversial with operative treatment being favoured but a shift to conservative management is occurring. Very little exists in medical literature about its management in Sub-Saharan Africa, where the paucity of thoracic surgeons is compounded by limited diagnostic and therapeutic facilities. We report three cases of oesophageal perforation which were all treated conservatively with tube thoracostomy, nil by mouth with feeding gastrostomy, intravenous antibiotics and chest physiotherapy. Two patients achieved oesophageal healing but one died due to severe septicaemia. In a resource restricted setting, conservative management which includes enteral nutrition by feeding gastrostomy, tube thoracostomy to drain inter pleural contaminants, intravenous antibiotics and chest physiotherapy is a safe and effective treatment for oesophageal perforations

A systems approach to identifying correlated gene targets for the loss of colour pigmentation in plants

<p>Abstract</p> <p>Background</p> <p>The numerous diverse metabolic pathways by which plant compounds can be produced make it difficult to predict how colour pigmentation is lost for different tissues and plants. This study employs mathematical and <it>in silico </it>methods to identify correlated gene targets for the loss of colour pigmentation in plants from a whole cell perspective based on the full metabolic network of <it>Arabidopsis</it>. This involves extracting a self-contained flavonoid subnetwork from the AraCyc database and calculating feasible metabolic routes or elementary modes (EMs) for it. Those EMs leading to anthocyanin compounds are taken to constitute the anthocyanin biosynthetic pathway (ABP) and their interplay with the rest of the EMs is used to study the minimal cut sets (MCSs), which are different combinations of reactions to block for eliminating colour pigmentation. By relating the reactions to their corresponding genes, the MCSs are used to explore the phenotypic roles of the ABP genes, their relevance to the ABP and the impact their eliminations would have on other processes in the cell.</p> <p>Results</p> <p>Simulation and prediction results of the effect of different MCSs for eliminating colour pigmentation correspond with existing experimental observations. Two examples are: i) two MCSs which require the simultaneous suppression of genes DFR and ANS to eliminate colour pigmentation, correspond to observational results of the same genes being co-regulated for eliminating floral pigmentation in <it>Aquilegia </it>and; ii) the impact of another MCS requiring CHS suppression, corresponds to findings where the suppression of the early gene CHS eliminated nearly all flavonoids but did not affect the production of volatile benzenoids responsible for floral scent.</p> <p>Conclusions</p> <p>From the various MCSs identified for eliminating colour pigmentation, several correlate to existing experimental observations, indicating that different MCSs are suitable for different plants, different cells, and different conditions and could also be related to regulatory genes. Being able to correlate the predictions with experimental results gives credence to the use of these mathematical and <it>in silico </it>analyses methods in the design of experiments. The methods could be used to prioritize target enzymes for different objectives to achieve desired outcomes, especially for less understood pathways.</p

Pre-Stressor Interference Control and Intrusive Memories

Although intrusive imagery is a common response in the aftermath of a stressful or traumatic event, only a minority of trauma victims show persistent re-experiencing and related psychopathology. Individual differences in pre-trauma executive control possibly play a critical role. Therefore, this study investigated whether a relatively poor pre-stressor ability to resist proactive interference in working memory might increase risk for experiencing undesirable intrusive memories after being exposed to a stressful event. Non-clinical participants (N = 85) completed a modified version of a widely used test of interference control in working memory (CVLT; Kramer and Delis 1991) and subsequently watched an emotional film fragment. Following presentation of the fragment, intrusive memories were recorded in a 1-week diary and at a follow up session 7 days later. A relatively poor ability to resist proactive interference was related to a relatively high frequency of film-related intrusive memories. This relationship was independent of neuroticism and gender. These findings are consistent with the idea that a pre-morbid deficit in the ability to resist proactive interference reflects a vulnerability factor for experiencing intrusive memories after trauma exposure

Lung adenocarcinoma originates from retrovirus infection of proliferating type 2 pneumocytes during pulmonary post-natal development or tissue repair

Jaagsiekte sheep retrovirus (JSRV) is a unique oncogenic virus with distinctive biological properties. JSRV is the only virus causing a naturally occurring lung cancer (ovine pulmonary adenocarcinoma, OPA) and possessing a major structural protein that functions as a dominant oncoprotein. Lung cancer is the major cause of death among cancer patients. OPA can be an extremely useful animal model in order to identify the cells originating lung adenocarcinoma and to study the early events of pulmonary carcinogenesis. In this study, we demonstrated that lung adenocarcinoma in sheep originates from infection and transformation of proliferating type 2 pneumocytes (termed here lung alveolar proliferating cells, LAPCs). We excluded that OPA originates from a bronchioalveolar stem cell, or from mature post-mitotic type 2 pneumocytes or from either proliferating or non-proliferating Clara cells. We show that young animals possess abundant LAPCs and are highly susceptible to JSRV infection and transformation. On the contrary, healthy adult sheep, which are normally resistant to experimental OPA induction, exhibit a relatively low number of LAPCs and are resistant to JSRV infection of the respiratory epithelium. Importantly, induction of lung injury increased dramatically the number of LAPCs in adult sheep and rendered these animals fully susceptible to JSRV infection and transformation. Furthermore, we show that JSRV preferentially infects actively dividing cell in vitro. Overall, our study provides unique insights into pulmonary biology and carcinogenesis and suggests that JSRV and its host have reached an evolutionary equilibrium in which productive infection (and transformation) can occur only in cells that are scarce for most of the lifespan of the sheep. Our data also indicate that, at least in this model, inflammation can predispose to retroviral infection and cancer

Financial Evaluation of Different Vaccination Strategies for Controlling the Bluetongue Virus Serotype 8 Epidemic in the Netherlands in 2008

Background: Bluetongue (BT) is a vector-borne disease of ruminants caused by bluetongue virus that is transmitted by biting midges (Culicoides spp.). In 2006, the introduction of BTV serotype 8 (BTV-8) caused a severe epidemic in Western and Central Europe. The principal effective veterinary measure in response to BT was believed to be vaccination accompanied by other measures such as movement restrictions and surveillance. As the number of vaccine doses available at the start of the vaccination campaign was rather uncertain, the Dutch Ministry of Agriculture, Nature and Food Quality and the Dutch agricultural industry wanted to evaluate several different vaccination strategies. This study aimed to rank eight vaccination strategies based on their efficiency (i.e. net costs in relation to prevented losses or benefits) for controlling the bluetongue virus serotype 8 epidemic in 2008 Methodology/Principal Findings: An economic model was developed that included the Dutch professional cattle, sheep and goat sectors together with the hobby farms. Strategies were evaluated based on the least cost - highest benefit frontier, the benefit-cost ratio and the total net returns. Strategy F, where all adult sheep at professional farms in the Netherlands would be vaccinated was very efficient at lowest costs, whereas strategy D, where additional to all adult sheep at professional farms also all adult cattle in the four Northern provinces would be vaccinated, was also very efficient but at a little higher costs. Strategy C, where all adult sheep and cattle at professional farms in the whole of the Netherlands would be vaccinated was also efficient but again at higher costs. Conclusions/Significance: This study demonstrates that a financial analysis differentiates between vaccination strategies and indicates important decision rules based on efficienc

The human immunodeficiency virus antigen Nef forms protein bodies in leaves of transgenic tobacco when fused to zeolin

Protein bodies (PB) are stable polymers naturally formed by certain seed storage proteins within the endoplasmic reticulum (ER). The human immunodeficiency virus negative factor (Nef) protein, a potential antigen for the development of an anti-viral vaccine, is highly unstable when introduced into the plant secretory pathway, probably because of folding defects in the ER environment. The aim of this study was to promote the formation of Nef-containing PB in tobacco (Nicotiana tabacum) leaves by fusing the Nef sequence to the N-terminal domains of the maize storage protein γ-zein or to the chimeric protein zeolin (which efficiently forms PB and is composed of the vacuolar storage protein phaseolin fused to the N-terminal domains of γ-zein). Protein blots and pulse–chase indicate that fusions between Nef and the same γ-zein domains present in zeolin are degraded by ER quality control. Consistently, a mutated zeolin, in which wild-type phaseolin was substituted with a defective version known to be degraded by ER quality control, is unstable in plant cells. Fusion of Nef to the entire zeolin sequence instead allows the formation of PB detectable by electron microscopy and subcellular fractionation, leading to zeolin–Nef accumulation higher than 1% of total soluble protein, consistently reproduced in independent transgenic plants. It is concluded that zeolin, but not its γ-zein portion, has a positive dominant effect over ER quality control degradation. These results provide insights into the requirements for PB formation and avoidance of quality-control degradation, and indicate a strategy for enhancing foreign protein accumulation in plants