A soluble guanylate cyclase stimulator, BAY 41-8543, preserves pulmonary artery endothelial function in experimental pulmonary embolism

Background: BAY 41-8543 reduces pulmonary vascular resistance and right ventricle injury in experimental PE. Objective: Test if BAY 41-8543 protects pulmonary artery (PA) endothelial function in PE. Methods: PE was induced (anesthetized, Sprague-Dawley rats, 25 µm polystyrene microspheres, 1.95 million/100g, IV) with BAY 41-8543 (50 ug/kg, IV) or solvent treatment. Controls had vehicle for microspheres. Rings isolated from primary PA branches (5hr. PE) were contracted (phenylephrine, 10-6M) and dilation was endothelium-dependent (acetylcholine, 10-7M – 10-5M) or with BAY 41-8543 (10-8M – 10-6M). Oxidant stress was assessed: PA tissue 4-hydroxynoneal (4-HNE) immunohistochemistry; plasma malondialdehyde (MDA). Other Control rings received red blood cell (RBC) lysate. Results: PE inhibited dilation to acetylcholine vs. Control (dose x group interaction p=0.001), while dilation to BAY 41-8543 was minimally changed. PE raised plasma hemoglobin (30-fold, p=0.003), 4-HNE stain and plasma MDA (2.2-fold, p=0.009). Treating PE rats with BAY 41-8543 reduced plasma hemoglobin, 4-HNE and MDA to levels not different from Control. Dilation to acetylcholine significantly improved in PE + BAY 41-8543 rats vs. PE (dose x group interaction p=0.04). Addition of RBC lysate to Control rings reduced dilation to acetylcholine, while BAY 41-8543 responses remained strong. Conclusion: PE caused PA endothelial dysfunction, elevated plasma hemoglobin and oxidant stress. Treating rats with BAY 41-8543 lowered plasma hemoglobin, oxidant stress and endothelial dysfunction in PE. Treating isolated rings with BAY 41-8543 bypassed endothelial dysfunction with PE or RBC lysate

Quantitative analysis of behaviour of grazing dairy cows

This research thesis describes the quantitative analysis of behaviour of grazing dairy cows in terms of sward height (SH) in combination with the length of the grazing session (grazing duration, GD), the time of allocation of fresh pasture and the type of carbohydrate supplement offered. A review of the literature (Chapter 2) identified that there was limited information on the combined affects of SH and GD on behaviour, herbage dry matter intake (DMI) and intake rate (IR) of dairy cows grazing sub-tropical pastures and how these interact to influence sward structure. Also, there was limited information on how SH x GD, time of allocation of fresh pasture and type of carbohydrate supplement offered affects the temporal patterns of behaviour and the subsequent time-dependent probabilities. In this current study, 2 levels of SH (10 and 13cm) and 5 levels of GD (1, 2, 4, 8 and 15h) were used to quantify the effects of SH and GD on dairy cow grazing behaviour, IR and herbage DMI. Sward height significantly (P70% of their total herbage DMI within the first 4h GD. Quantification of the sward profiles after each SH x GD combination showed that dairy cows grazing kikuyu using the management described in this current study did not graze at random. ... The results from this current thesis highlight the factors that either encourage or discourage grazing by dairy cows and should also help to improve decision tools used for pasture rotation, supplementary feeding and stocking density

Identification of elongated cilia and chiral malformation in TMEM67 mutant brains

poster abstractTransmembrane protein 67 (TMEM67) is encoded by one of four syndromic encephalocele genes. In humans a mutation in TMEM67 causes Meckel Gruber Syndrome, type 3 (MKS3) which is characterized by severe encephalocele and cystic kidneys and is usually fatal in the neonatal period. MKS3 is one of a spectrum of diseases known as ciliopathies because the proteins responsible for the disease are found in cells with the primary cilia. Primary cilia are a single, hair-like organelle that is found on the apical membrane of polarized cells and is thought to be involved in formation of left-right asymmetry during development as well as mechano- and chemo-reception. Here we characterize previously unreported details of cerebral phenotype in the Wistar polycystic kidney (Wpk) rats with a TMEM67 mutation. In choroid plexus (CP) epithelia of wild type animals, TMEM67 localizes to the plasma membrane and to a region close to the basal side of CP primary cilia. In a choroid plexus cell line that forms an epithelial sheet, the TMEM67 is found intracellularly but also localizes to the junctional complexes as evidenced by β catenin co-localization. Absence of normal TMEM67 leads to elongation of primary cilia in the ependymal cells lining the cerebral ventricles of the TMEM67-/- animals indicating that this protein is involved in the regulation of cilia length. Reduced aqueduct, bilateral dilatation with fusion of lateral ventricles, swelling of the hippocampus, and altered hindbrain histoarchitecture are noted in the TMEM67-/- rats. In the heterozygous animals mild asymmetric ventriculomegaly primarily on the left side is observed during early postnatal periods and continues into adulthood. These results suggest that TMEM67 is required for cilia length control and normal development of cerebral midline that maintains the symmetry of the left and right hemispheres. The Wpk rat model, orthologous to human MKS3, provides a unique model in which to study the development of both severe (TMEM67-/-) and mild (TMEM67+/-) hydrocephalus and other developmental abnormalities that are commonly found in human patients with ciliopathies

Increasing weight-bearing physical activity and calcium-rich foods to promote bone mass gains among 9–11 year old girls: outcomes of the Cal-Girls study

BACKGROUND: A two-year, community-based, group-randomized trial to promote bone mass gains among 9–11 year-old girls through increased intake of calcium-rich foods and weight-bearing physical activity was evaluated. METHODS: Following baseline data collection, 30 5th-grade Girl Scout troops were randomized to a two-year behavioral intervention program or to a no-treatment control group. Evaluations were conducted at baseline, one year, and two years. Measures included bone mineral content, density, and area (measured by DXA), dietary calcium intake (24-hour recall), and weight-bearing physical activity (physical activity checklist interview). Mixed-model regression was used to evaluate treatment-related changes in bone mineral content (g) for the total body, lumbar spine (L1-L4), proximal femur, one-third distal radius, and femoral neck. Changes in eating and physical activity behavioral outcomes were examined. RESULTS: Although the intervention was implemented with high fidelity, no significant intervention effects were observed for total bone mineral content or any specific bone sites. Significant intervention effects were observed for increases in dietary calcium. No significant intervention effects were observed for increases in weight-bearing physical activity. CONCLUSION: Future research needs to identify the optimal dosage of weight-bearing physical activity and calcium-rich dietary behavior change required to maximize bone mass gains in pre-adolescent and adolescent girls

Role of TC21/R-Ras2 in enhanced migration of neurofibromin-deficient Schwann cells

The neurofibromatosis type 1 tumor suppressor protein neurofibromin, is a GTPase activating protein for H-, N-, K-, R-Ras and TC21/R-Ras2 proteins. We demonstrate that Schwann cells derived from Nf1-null mice have enhanced chemokinetic and chemotactic migration in comparison to wild-type controls. Surprisingly, this migratory phenotype is not inhibited by a farnesyltransferase inhibitor or dominant-negative (dn) (N17)H-Ras (which inhibits H-, N-, and K-Ras activation). We postulated that increased activity of R-Ras and/or TC21/R-Ras2, due to loss of Nf1, contributes to increased migration. Mouse Schwann cells (MSCs) express R-Ras and TC21/R-Ras2 and their specific guanine exchange factors, C3G and AND-34. Infection of Nf1-null MSCs with a dn(43N)R-Ras adenovirus (to inhibit both R-Ras and TC21/R-Ras2 activation) decreases migration by approximately 50%. Conversely, expression of activated (72L)TC21/R-Ras2, but not activated (38V)R-Ras, increases migration, suggesting a role of TC21/R-Ras2 activation in the migration of neurofibromin-deficient Schwann cells. TC21/R-Ras2 preferentially couples to the phosphatidylinositol 3-kinase (PI3-kinase) and MAP kinase pathways. Treatment with a PI3-kinase or MAP kinase inhibitor reduces Nf1-null Schwann cell migration, implicating these TC21 effectors in Schwann cell migration. These data reveal a key role for neurofibromin regulation of TC21/R-Ras2 in Schwann cells, a cell type critical to NF1 tumor pathogenesis

Development of a parental feeding goal measure: the family mealtime goals questionnaire

It is well established that parents’ feeding practices predict children’s eating behaviors. However, there has been little research into parents’ mealtime goals – their desired outcomes for family mealtimes. These goals, and potential conflicts between them, may be important both in explaining parents’ feeding practices and improving children’s eating behaviors, as health behavior change is more likely to be achieved by programmes and interventions that are aligned with an individual’s goals. The objectives of this study were to develop a reliable and valid measure that captures parental mealtime goals, and to describe parents’ endorsement of these goals. Online questionnaire methods were used to design and test the Family Mealtime Goals Questionnaire with 1,140 parents and carers of at least one child aged from 1 to 16 years. Exploratory qualitative analysis, Principal Components Analysis, Confirmatory Factor Analysis and test-retest analysis (using intraclass correlations) were conducted to establish the psychometric properties of the instrument. An 18-item questionnaire was produced with seven dimensions: stress/conflict avoidance, homemade food, shared family food, family involvement in mealtimes, price, occasional treats, and high/low fat regulation. Some differences were found in the goal structure of parents of children of different ages but stress/conflict avoidance was the most strongly endorsed mealtime goal for all age groups. The Family Mealtime Goals Questionnaire provides a useful measure of parents’ feeding motivations. It will facilitate large-scale research into the relationships between parents' feeding goals and practices and could inform the design of more effective healthy eating interventions that target specific feeding goals

Plants Modify Biological Processes to Ensure Survival following Carbon Depletion: A Lolium perenne Model

BACKGROUND: Plants, due to their immobility, have evolved mechanisms allowing them to adapt to multiple environmental and management conditions. Short-term undesirable conditions (e.g. moisture deficit, cold temperatures) generally reduce photosynthetic carbon supply while increasing soluble carbohydrate accumulation. It is not known, however, what strategies plants may use in the long-term to adapt to situations resulting in net carbon depletion (i.e. reduced photosynthetic carbon supply and carbohydrate accumulation). In addition, many transcriptomic experiments have typically been undertaken under laboratory conditions; therefore, long-term acclimation strategies that plants use in natural environments are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: Perennial ryegrass (Lolium perenne L.) was used as a model plant to define whether plants adapt to repetitive carbon depletion and to further elucidate their long-term acclimation mechanisms. Transcriptome changes in both lamina and stubble tissues of field-grown plants with depleted carbon reserves were characterised using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The RT-qPCR data for select key genes indicated that plants reduced fructan degradation, and increased photosynthesis and fructan synthesis capacities following carbon depletion. This acclimatory response was not sufficient to prevent a reduction (P<0.001) in net biomass accumulation, but ensured that the plant survived. CONCLUSIONS: Adaptations of plants with depleted carbon reserves resulted in reduced post-defoliation carbon mobilization and earlier replenishment of carbon reserves, thereby ensuring survival and continued growth. These findings will help pave the way to improve plant biomass production, for either grazing livestock or biofuel purposes

Thromboelastography-Guided Anticoagulant Therapy for the Double Hazard of Thrombohemorrhagic Events in COVID-19: A Report of 3 Cases

BACKGROUND: The novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), often manifests a coagulopathy in severely ill patients, which may cause hemorrhage and/or thrombosis of varying severity. This report comprises the cases of 3 patients with COVID-19-associated coagulopathy who were evaluated with thromboelastography (TEG) and activated partial thromboplastin time (aPTT) to enable personalized anticoagulant therapy. CASE REPORT: Three patients presented with COVID-19 pneumonia, confirmed by reverse transcription-polymerase chain reaction, who developed thrombohemorrhagic coagulopathy. Case 1: A 72-year-old woman on long-term warfarin therapy for a history of venous thromboembolism developed a right upper lobe pulmonary embolus, despite an international normalized ratio of 6.4 and aPTT of 120.7 s. TEG enabled successful anticoagulation with heparin, and her pulmonary infarct was no longer present 2 weeks later. Case 2: A 55-year-old woman developed a rectus sheath hematoma while on heparin, and TEG demonstrated increased fibrinolysis despite COVID-19 patients more commonly undergoing fibrinolytic shutdown. Case 3: A 43-year-old woman had significant thrombus burden while severely hypocoagulable according to laboratory testing. As the venous thrombi enlarged in a disseminated intravascular coagulopathic-like state, the heparin dose was escalated to achieve a target aPTT of 70 to 80 s, resulting in a flat line TEG tracing. CONCLUSIONS: These 3 cases of COVID-19 pneumonia with complex and varied clinical histories demonstrated the clinical value of TEG combined with the measurement of aPTT to facilitate personalized anticoagulation, resulting in good clinical outcomes