Influence of different methods of bed compression on protein separation in process chromatography

This thesis examines the effects of hydrodynamic and mechanical compression on process chromatography. Poorly packed columns can have serious consequences on the performance of chromatography and efforts to understand the impact of different methods of compression on protein separation is limited in the literature. By understanding this impact, there is significant potential for facilitating better decisions in chromatographic operations, minimising batch failures while achieving high chromatographic performance. Conventional methods were used to quantify five different structural properties of chromatographic resins; the column efficiency was used to assess the quality of packing and porosity tests was used to determine the interparticle and intraparticle porosity of the packed bed. The influence of bed length, column diameter, and average particle size on the extent of bed compression were examined. The results showed better asymmetry and reduced plate height with both increasing levels of hydrodynamic and mechanical compression. There were practical limitations in using the conventional approaches to investigate the quality of packing; column efficiency and porosity tests only provide an overall indication of the whole column. The reverse-flow technique using an acetone tracer was therefore developed as a novel technique in this field to quantify the microscopic dispersion effects due to bed compression on defined axial sections within a packed bed. This technique allows reversible macroscopic factors to be separated from irreversible microscopic factors. The results showed higher levels of compression towards the bottom of the column with hydrodynamic compression and higher levels of compression towards the top of the column with mechanical compression. This technique has shown to be a simple, non-intrusive method for investigating microscopic factors along the different sections of the column. The breakthrough curves were used to determine the dynamic binding capacities for three different anion exchange resins using BSA as a model protein. Q Sepharose Fast Flow, Q Sepharose High Performance and Capto Q were selected to cover a range of bead rigidity and particles sizes. The shape and position of the breakthrough curves were used to assess quantitatively the impact of bed compression on binding capacity and mass transfer properties. In particular, a range of rigidity and particle sizes of AEX chromatography resins were examined. The results showed the overall impact of compression on breakthrough performance depended heavily on the method of compression applied to the bed. For both hydrodynamic and mechanical compression, the dynamic binding capacity (DBC) increased by 60% for Capto Q. However, when Q Sepharose FF, a softer resin was hydrodynamically compressed the DBC decreased by 10% at 0.15 CF. By contrast, when Q Sepharose HP (2 – 3 times smaller than Q Sepharose FF) was hydrodynamically compressed to the equivalent compression factor, the DBC increased by 20%. This suggests that the particle size distribution (PSD) also influenced changes in breakthrough behaviour when compressed. For all three resins tested, mechanical compression produced the largest increases in DBC. Finally, purification factor vs. yield (PFY) diagrams were used to relate directly the effects of bed compression to the maximum purity and yield at each compression factor. In this study, fractionation diagrams were adapted to describe the elution profiles of the product and its various impurities to show the relationships between bed compression and overall chromatographic performance. A protein mixture was used to challenge three AEX resins (Q Sepharose Fast Flow, Q Sepharose High Performance, and Capto Q) and subsequently a gel filtration resin (Sepharose CL-6B). In particular, the effects of one-step vs. multiple incremental step compression were also examined. The results showed one-step hydrodynamic compression caused flow instability, due to the formation of regions of higher compaction towards the bottom of the packed bed which together resulted in poor protein separation. With mechanical compression via multiple incremental steps, an even distribution of pressure was applied from the top column diameter which gave greater levels of product purity and yield for all resins

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

A prospective study of the health effects of alcohol consumption in middle-aged and elderly men. The Honolulu Heart Program

BACKGROUND: The study objective was to determine the association between reported alcohol consumption and total mortality, mortality from selected causes, and incident nonfatal chronic disease events in middle-aged (51 to 64 years old) and elderly (65 to 75 years old) men during an approximate 15-year follow-up period. METHODS AND RESULTS: We conducted a prospective epidemiological study of Japanese-American men who were participating in the Honolulu Heart Program and were free from coronary heart disease, cerebrovascular disease, and cancer at baseline examination and at subsequent reexamination 6 years later. Self-reported alcohol consumption was determined twice: at the baseline examination in 1965 through 1968 and at reexamination approximately 6 years later (1971 through 1974). Four primary alcohol consumption groups who reported similar alcohol intake at the time of these two clinical examinations were considered: abstainers and light (1 to 14 mL of alcohol per day), moderate (15 to 39 mL of alcohol per day), and heavy (\u3e or = 40 mL of alcohol per day) drinkers. Study end points were also determined in very light (1 to 4.9 mL of alcohol per day) drinkers and in men who reported a change in their alcohol intake between examinations. Longitudinal follow-up was carried out through the end of 1988 with determination of selected fatal and nonfatal events according to alcohol intake. After controlling for several potentially confounding factors, total mortality exhibited a J-shaped pattern in relation to alcohol consumption in middle-aged and elderly men. There was a trend for lower rates of occurrence of combined fatal and nonfatal coronary heart disease events with increasing alcohol consumption in both middle-aged and elderly men. Increasing alcohol consumption was related to an increased risk of fatal and nonfatal strokes in middle-aged men, whereas elderly light and moderate drinkers were at increased risk for fatal and nonfatal strokes. Heavy drinkers were at increased risk for fatal and nonfatal malignant neoplasms in the two age groups examined. CONCLUSIONS: The results of this long-term prospective study provide a balanced perspective of the health effects of alcohol consumption in middle-aged and elderly men. High levels of alcohol consumption were shown to be related to an increasing risk of diseases of considerable public health importance. These findings suggest that caution be taken in formulating population-wide recommendations for increases in the population levels of alcohol consumed given the associated significant social and biological problems of high consumption levels

Bi-level fuzzy optimization model of an algae-sugarcane-based eco-industrial park

Eco-industrial parks (EIPs) are designed to serve as effective measures in mitigating resource depletion and improving the environmental footprint of industrial processes. The system implements the concept of industrial symbiosis wherein an exchange of resources is conducted among the plants to achieve mutual economic and environmental benefit. The park authority has an objective of minimizing the environmental footprints of the EIP, and each respective plant aims to maximize its annual net profit while satisfying product demand. Thus, the design of the multiple resource type exchange network within the EIP can be adopted as a bi-level fuzzy optimization model, with the park authority designated as the upper-level decision-maker. The study investigates the impact of environmental footprint limits set by the park authority in the optimal design of the resource exchange networks between the plants in the EIP. A case study involving an algae-sugarcane-based eco-industrial park is considered to demonstrate the model. The results indicate that a compromise can be achieved between the levels of decision-makers at an overall degree of satisfaction of 0.189. This suggests the feasibility of the proposed EIP model accounting for the objectives of both levels of decision-makers. © 2017, AIDIC Servizi S.r.l

Lifestyle and biologic factors associated with atherosclerotic disease in middle-aged men. 20-year findings from the Honolulu Heart Program

OBJECTIVES: To examine the association between a variety of baseline lifestyle and biologic factors in a middle-aged cohort of Japanese-American men and the 20-year incidence rates of total atherosclerotic end points and each of the initial clinical manifestations of this disease, including fatal and nonfatal coronary heart disease, angina pectoris, thromboembolic strokes, and aortic aneurysms. DESIGN: Prospective epidemiologic study. POPULATION: Japanese-American men (N = 2710) between the ages of 55 and 64 years at the time of the initial clinical examination of the Honolulu Heart Program (1965 through 1968) free from evidence of coronary heart disease, cerebrovascular disease, cancer, or aortic aneurysms. RESULTS: Among the men studied, 602 atherosclerotic events developed during the 23-year period of follow-up (1965 through 1988). After adjustment for each of the baseline characteristics examined, significant positive associations between quartile cutoffs of body mass index, systolic blood pressure, serum levels of cholesterol, triglycerides, glucose, and uric acid, as well as cigarette smoking, and the occurrence of any atherosclerotic end point were seen, while an inverse association with alcohol consumption was observed. Characteristics associated with the development of other fatal and nonfatal clinical events in this cohort, including coronary heart disease, thromboembolic stroke, and aortic aneurysms are presented with accompanying relative and attributable risks. CONCLUSIONS: The results of this prospective epidemiologic study provide insights to the long-term predictive utility of the commonly accepted risk factors for coronary heart disease in relation to the different clinical manifestations of atherosclerosis in a middle-aged male cohort followed up for approximately 20 years. These results provide additional support for risk factor modification in middle-aged men and for the encouragement of positive long-term lifestyle changes

Estimation of fetal lung volume using enhanced 3-dimensional ultrasound: a new method and first result

Objective To measure fetal lung volume using a computer based, enhanced, 3-dimensional ultrasound imaging system.Design An observational studySetting The Fetal Medicine Unit at Guys Hospital, LondonParticipants Twenty healthy women with a singleton pregnancy between 24 and 36 weeks of gestation were scanned on one occasion during pregnancy using an ultrasound based 3-dimensional imaging system. All delivered at term with weights above the 10th centile for gestation.Results Total lung volume increased exponentially with gestational age. Right lung volume measured consistently greater than left lung volume.Conclusions The use of this new enhanced 3-dimensional imaging system allows for estimations of fetal lung volume. Preliminary data confirm that fetal lung volume, measured by a computerised 3-dimensional ultrasound imaging system increased exponentially with gestational age. The use of this system has obvious application in the further study of lung growth in utero and possible clinical application in disease states where fetal lung growth may be impaired

Carbon dioxide reduction incentive for eco-industrial parks using bilevel fuzzy programming

A potential approach in improving the sustainability of microalgae biofuels is through eco-industrial parks. Eco-industrial parks implement industrial symbiosis to generate economic and environmental benefits. The operation of an eco-industrial park involves the interaction of the park authority and the industry plants. Their conflicting objectives lead to the determination of a compromise solution between them. However, the industrial plants may not cooperate since the compromise solution is generally suboptimal for their respective objectives. The situation results to increased emissions of carbon dioxide which has the highest contribution to climate change among the greenhouse gases. Thus, a bi-level fuzzy optimization model for algae-based eco-industrial parks under carbon dioxide reduction incentives was proposed to address these. The results of the case study showed that the use of carbon dioxide reduction incentives improved both the environmental and economic aspects of the compromise solution obtained between the park authority and the industrial plants. The obtained cost savings per industrial plant were increased beyond their respective optimal values. It was noteworthy that the incentive used did not exceed its upper limit. Overall, the incentives enhanced the cost savings and carbon dioxide reduction of the algae-based eco-industrial park. In addition, the developed model can aid the decision-makers in designing algae-based eco-industrial parks and determining the appropriate regulatory frameworks to enhance the industrial symbiosis. Measures aside from carbon dioxide can also be used. © 2017 IEEE

Are We Getting It Right? A Scoping Review of Outcomes Reported in Cell Therapy Clinical Studies for Cerebral Palsy

Cell therapies are an emergent treatment for cerebral palsy (CP) with promising evidence demonstrating efficacy for improving gross motor function. However, families value improvements in a range of domains following intervention and the non-motor symptoms, comorbidities and complications of CP can potentially be targeted by cell therapies. We conducted a scoping review to describe all outcomes that have been reported in cell therapy studies for CP to date, and to examine what instruments were used to capture these. Through a systematic search we identified 54 studies comprising 2066 participants that were treated with a range of cell therapy interventions. We categorized the reported 53 unique outcome instruments and additional descriptive measures into 10 categories and 12 sub-categories. Movement and Posture was the most frequently reported outcome category, followed by Safety, however Quality of Life, and various prevalent comorbidities and complications of CP were infrequently reported. Notably, many outcome instruments used do not have evaluative properties and thus are not suitable for measuring change following intervention. We provide a number of recommendations to ensure that future trials generate high-quality outcome data that is aligned with the priorities of the CP community

Combined effects of HDL cholesterol, triglyceride, and total cholesterol concentrations on 18-year risk of atherosclerotic disease

BACKGROUND: Whether the combination of a low level of HDL cholesterol (HDL-C) and high level of triglyceride (TG) confers increased risk of cardiovascular disease and whether risk varies across levels of total cholesterol (TC) are not well established. Combined effects of HDL-C, TG, and TC on the incidence of atherosclerotic disease were examined prospectively in Japanese-American men from the Honolulu Heart Program. METHODS AND RESULTS: Among 1,646 men aged 51 to 72 years who were free of coronary heart disease (CHD), stroke, and cancer and were not taking lipid-lowering medication, 318 developed atherosclerotic events (angina, coronary insufficiency, aortic aneurysm, definite CHD, or thromboembolic stroke) and 170 developed definite CHD between 1970 and 1988. Subjects were stratified by TC level (desirable, \u3c 200 mg/dL; borderline high, 200 to 239 mg/dL; high, \u3e or = 240 mg/dL), HDL-C level (\u3c 35 and \u3e or = 35 mg/dL), and TG level (\u3c 200 and \u3e or = 200 mg/dL). With Cox regression with high HDL-C and low TG as reference, age-adjusted relative risks (RR) of atherosclerotic events were significantly elevated in men with low HDL-C and high TG at borderline-high (RR, 2.46; 95% CI, 1.48 to 4.09) and high (RR, 2.21; 95% CI, 1.34 to 3.66) TC levels but not in men with desirable TC levels (RR, 0.89; 95% CI, 0.38 to 2.09). Elevated risks were independent of blood pressure, obesity, fat distribution, diabetes, smoking, and alcohol. Results were not materially altered by exclusion of subjects with angina alone and were similar but somewhat weaker for CHD. CONCLUSIONS: Risk of atherosclerotic disease appears elevated in subjects with low HDL-C and high TG levels when TC is borderline high or high, independent of other cardiovascular risk factors. These findings support recent cholesterol screening recommendations and suggest that joint effects of HDL-C and TG may be important to consider