Development of a Tabletop Soft Gel Encapsulation Machine

Currently, to test new formulations of gel capsules at Pfizer, they must use the large-scale machine that requires a minimum of 25 kg of gel melt and produce hundreds of capsules per run. Production at a smaller scale to enable rapid changeover for research and development is desired. The team’s goal was to achieve continuous production of sealed capsules with 80% fill capacity. Capsule sealing was the prime consideration. Preliminary trials using the existing system and heat transfer analysis indicated localized heating was necessary to promote capsule sealing. To provide localized heating, a brass wedge was designed based on the pilot scale machine. The machined wedge was integrated with a PID control system. Using pre-made gelatin ribbons, the appropriate process parameters to achieve sealed capsules were determined. The critical, coupled parameters were die roll temperature, wedge temperature, wedge height, and die roll speed. Capsule sealing efficiency was highest at a speed of 4 capsules/min. For air-filled capsules, a sealing efficiency of 100% was achieved. For PEG-400-filled capsules, a sealing efficiency of 50% was achieved. Future work will include integration with the gelatin feed system and addition of a vacuum during capsule formation to increase fill capacity.https://scholarscompass.vcu.edu/capstone/1151/thumbnail.jp

Genome-wide association mapping of leaf mass traits in a Vietnamese rice landrace panel

Leaf traits are often strongly correlated with yield, which poses a major challenge in rice breeding. In the present study, using a panel of Vietnamese rice landraces genotyped with 21,623 single-nucleotide polymorphism markers, a genome-wide association study (GWAS) was conducted for several leaf traits during the vegetative stage. Vietnamese landraces are often poorly represented in panels used for GWAS, even though they are adapted to contrasting agrosystems and can contain original, valuable genetic determinants. A panel of 180 rice varieties was grown in pots for four weeks with three replicates under nethouse conditions. Different leaf traits were measured on the second fully expanded leaf of the main tiller, which often plays a major role in determining the photosynthetic capacity of the plant. The leaf fresh weight, turgid weight and dry weight were measured; then, from these measurements, the relative tissue weight and leaf dry matter percentage were computed. The leaf dry matter percentage can be considered a proxy for the photosynthetic efficiency per unit leaf area, which contributes to yield. By a GWAS, thirteen QTLs associated with these leaf traits were identified. Eleven QTLs were identified for fresh weight, eleven for turgid weight, one for dry weight, one for relative tissue weight and one for leaf dry matter percentage. Eleven QTLs presented associations with several traits, suggesting that these traits share common genetic determinants, while one QTL was specific to leaf dry matter percentage and one QTL was specific to relative tissue weight. Interestingly, some of these QTLs colocalize with leaf- or yield-related QTLs previously identified using other material. Several genes within these QTLs with a known function in leaf development or physiology are reviewed

Cytochrome b Mutations That Modify the Ubiquinol-binding Pocket of the Cytochrome bc 1 Complex and Confer Anti-malarial Drug Resistance in Saccharomyces cerevisiae

Atovaquone is a new anti-malarial agent that specifically targets the cytochrome bc1 complex and inhibits parasite respiration. A growing number of failures of this drug in the treatment of malaria have been genetically linked to point mutations in the mitochondrial cytochrome b gene. To better understand the molecular basis of atovaquone resistance in malaria, we introduced five of these mutations, including the most prevalent variant found in Plasmodium falciparum (Y268S), into the cytochrome b gene of the budding yeast Saccharomyces cerevisiae and thus obtained cytochrome bc1 complexes resistant to inhibition by atovaquone. By modeling the variations in cytochrome b structure and atovaquone binding with the mutated bc1 complexes, we obtained the first quantitative explanation for the molecular basis of atovaquone resistance in malaria parasites

A 'combined framework' approach to developing a patient decision aid: the PANDAs model

Background There is a lack of practical research frameworks to guide the development of patient decision aids [PtDAs]. This paper described how a PtDA was developed using the International Patient Decision Aids (IPDAS) guideline and UK Medical Research Council (UKMRC) frameworks to support patients when making treatment decisions in type 2 diabetes mellitus. Methods This study used mixed methods to develop a PtDA for use in a UK general practice setting. A 10-member expert panel was convened to guide development and patients and clinicians were also interviewed individually using semi-structured interview guides to identify their decisional needs. Current literature was reviewed systematically to determine the best available evidence. The Ottawa Decision Support Framework was used to guide the presentation of the information and value clarification exercise. An iterative draft-review-revise process by the research team and review panel was conducted until the PtDA reached content and format `saturation’. The PtDA was then pilot-tested by users in actual consultations to assess its acceptability and feasibility. The IPDAS and UKMRC frameworks were used throughout to inform the development process. Results The PANDAs PtDA was developed systematically and iteratively. Patients and clinicians highlighted the needs for information, decisional, emotional and social support, which were incorporated into the PtDA. The literature review identified gaps in high quality evidence and variations in patient outcome reporting. The PtDA comprised five components: background of the treatment options; pros and cons of each treatment option; value clarification exercise; support needs; and readiness to decide. Conclusions This study has demonstrated the feasibility of combining the IPDAS and the UKMRC frameworks for the development and evaluation of a PtDA. Future studies should test this model for developing PtDAs across different decisions and healthcare contexts

Prescribing practice for malaria following introduction of artemether-lumefantrine in an urban area with declining endemicity in West Africa

<p>Abstract</p> <p>Background</p> <p>The decline in malaria coinciding with the introduction of newer, costly anti-malarials has prompted studies into the overtreatment for malaria mostly in East Africa. The study presented here describes prescribing practices for malaria at health facilities in a West African country.</p> <p>Methods</p> <p>Cross-sectional surveys were carried out in two urban Gambian primary health facilities (PHFs) during and outside the malaria transmission season. Facilities were comparable in terms of the staffing compliment and capability to perform slide microscopy. Patients treated for malaria were enrolled after consultations and blood smears collected and read at a reference laboratory. Slide reading results from the PHFs were compared to the reference readings and the proportion of cases treated but with a negative test result at the reference laboratory was determined.</p> <p>Results</p> <p>Slide requests were made for 33.2% (173) of those enrolled, being more frequent in children (0-15 yrs) than adults during the wet season (p = 0.003). In the same period, requests were commoner in under-fives compared to older children (p = 0.022); however, a positive test result was 4.4 times more likely in the latter group (p = 0.010). Parasitaemia was confirmed for only 4.7% (10/215) and 12.5% (37/297) of patients in the dry and wet seasons, respectively. The negative predictive value of a PHF slide remained above 97% in both seasons.</p> <p>Conclusions</p> <p>The study provides evidence for considerable overtreatment for malaria in a West African setting comparable to reports from areas with similar low malaria transmission in East Africa. The data suggest that laboratory facilities may be under-used, and that adherence to negative PHF slide results could significantly reduce the degree of overtreatment. The "peak prevalence" in 5-15 year olds may reflect successful implementation of malaria control interventions in under-fives, but point out the need to extend such interventions to older children.</p

The MOBI-Kids Study Protocol: Challenges in Assessing Childhood and Adolescent Exposure to Electromagnetic Fields from Wireless Telecommunication Technologies and Possible Association with Brain Tumor Risk

The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF). MOBI-Kids, a multinational case-control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10-24 years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure and brain tumor risk in young people in a large number of countries is complex and poses methodological challenges. This manuscript discusses the design of MOBI-Kids and describes the challenges and approaches chosen to address them, including: (1) the choice of controls operated for suspected appendicitis, to reduce potential selection bias related to low response rates among population controls; (2) investigating a young study population spanning a relatively wide age range; (3) conducting a large, multinational epidemiological study, while adhering to increasingly stricter ethics requirements; (4) investigating a rare and potentially fatal disease; and (5) assessing exposure to EMF from communication technologies. Our experience in thus far developing and implementing the study protocol indicates that MOBI-Kids is feasible and will generate results that will contribute to the understanding of potential brain tumor risks associated with use of mobile phones and other wireless communications technologies among young people

Estrogen Receptor β-Selective Agonists Stimulate Calcium Oscillations in Human and Mouse Embryonic Stem Cell-Derived Neurons

Estrogens are used extensively to treat hot flashes in menopausal women. Some of the beneficial effects of estrogens in hormone therapy on the brain might be due to nongenomic effects in neurons such as the rapid stimulation of calcium oscillations. Most studies have examined the nongenomic effects of estrogen receptors (ER) in primary neurons or brain slices from the rodent brain. However, these cells can not be maintained continuously in culture because neurons are post-mitotic. Neurons derived from embryonic stem cells could be a potential continuous, cell-based model to study nongenomic actions of estrogens in neurons if they are responsive to estrogens after differentiation. In this study ER-subtype specific estrogens were used to examine the role of ERα and ERβ on calcium oscillations in neurons derived from human (hES) and mouse embryonic stem cells. Unlike the undifferentiated hES cells the differentiated cells expressed neuronal markers, ERβ, but not ERα. The non-selective ER agonist 17β-estradiol (E2) rapidly increased [Ca2+]i oscillations and synchronizations within a few minutes. No change in calcium oscillations was observed with the selective ERα agonist 4,4′,4″-(4-Propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT). In contrast, the selective ERβ agonists, 2,3-bis(4-Hydroxyphenyl)-propionitrile (DPN), MF101, and 2-(3-fluoro-4-hydroxyphenyl)-7-vinyl-1,3 benzoxazol-5-ol (ERB-041; WAY-202041) stimulated calcium oscillations similar to E2. The ERβ agonists also increased calcium oscillations and phosphorylated PKC, AKT and ERK1/2 in neurons derived from mouse ES cells, which was inhibited by nifedipine demonstrating that ERβ activates L-type voltage gated calcium channels to regulate neuronal activity. Our results demonstrate that ERβ signaling regulates nongenomic pathways in neurons derived from ES cells, and suggest that these cells might be useful to study the nongenomic mechanisms of estrogenic compounds