1,004 research outputs found
Recent advances in the understanding and care of familial hypercholesterolaemia: significance of the biology and therapeutic regulation of proprotein convertase subtilisin/kexin type 9
No full textFamilial hypercholesterolaemia (FH) is an autosomal co-dominant disorder that markedly raises plasma low-density lipoprotein-cholesterol (LDL-C) concentration, causing premature atherosclerotic coronary artery disease (CAD). FH has recently come under intense focus and, although there is general consensus in recent international guidelines regarding diagnosis and treatment, there is debate about the value of genetic studies. Genetic testing can be cost-effective as part of cascade screening in dedicated centres, but the full mutation spectrum responsible for FH has not been established in many populations, and its use in primary care is not at present logistically feasible. Whether using genetic testing or not, cholesterol screening of family members of index patients with an abnormally raised LDL-C must be used to determine the need for early treatment to prevent the development of CAD. The metabolic defects in FH extend beyond LDL, and may affect triacylglycerol-rich and high-density lipoproteins, lipoprotein(a) and oxidative stress. Achievement of the recommended targets for LDL-C with current treatments is difficult, but this may be resolved by new drug therapies. Lipoprotein apheresis remains an effective treatment for severe FH and, although expensive, it costs less than the two recently introduced orphan drugs (lomitapide and mipomersen) for homozygous FH. Recent advances in understanding of the biology of proprotein convertase subtilisin/kexin type 9 (PCSK9) have further elucidated the regulation of lipoprotein metabolism and led to new drugs for effectively treating hypercholesterolaemia in FH and related conditions, as well as for treating many patients with statin intolerance. The mechanisms of action of PCSK9 inhibitors on lipoprotein metabolism and atherosclerosis, as well as their impact on cardiovascular outcomes and cost-effectiveness, remain to be established
Practical guidance for food consumption to prevent cardiovascular disease
No full textData source: Supplementary Data, https://doi.org/10.1016/j.hlc.2020.08.022
Link to a related website: http://www.heartlungcirc.org/article/S1443950620304765/pdf, Open Access via UnpaywallAbstract not available.Paul J. Nestel, Lawrence J. Beilin, Peter M. Clifton, Gerald F. Watts, Trevor A. Mor
Occupied City: New Orleans Under the Federals 1862–1865
No full textNew Orleans is the largest American city ever occupied by enemy forces for an extended period of time. Falling to an amphibious Federal force in the spring of 1862, the city was threatened with the possibility of Confederate recapture even as late as 1864. How this tension affected the lives of both civilians and soldiers during the occupation is here examined.
Gerald M. Capers finds that the occupation policies of General Benjamin F. Butler and General Nathaniel P. Banks were successful and that Butler’s harsh policies were by no means as vicious as legend would have it. Banks at first reversed Butler’s harsh policies, but was gradually compelled to become less lenient. Banks did succeed in establishing a civil government under Lincoln’s orders, but Congress refused to recognize the civil government and imposed a reconstruction government at war’s end.
Life for the average resident of New Orleans, Capers states, was much better during the occupation than it was for Southerners in areas still in Confederate control. Relative economic decline had begun in the 1850’s but New Orleans even enjoyed a war boom during the last two years. And although America’s only brief experience as an occupation force at the time had been in Vera Cruz during 1846, Butler and Banks performed their duties well.
Gerald M. Capers, head of the Department of History at Newcomb College, Tulane University, is the author of several books, among them Stephen A. Douglas: Defender of the Union.https://uknowledge.uky.edu/upk_united_states_history/1052/thumbnail.jp
Phytosterols and phytostanols in context: From physiology and pathophysiology to food supplementation and clinical practice
No full textPhytosterols and phytostanols are two classes of sterol derivatives naturally synthesised in plants, but not in humans. Structurally, phytosterols and phytostanols have a sterane ring in common, but phytostanols do not have a double bond between carbons 5 and 6. The therapeutic potential of phytosterols and phytostanols supplementation in cholesterol reduction is the main reason for its wide usage in an expansive food matrix, including milk, yoghurt, margarine, mayonnaise, chocolate, tartare, chips, esterification with omega-3, and recently, as a successful nutraceutical among athletes is its fortification with whey protein. The heterogeneous effect of phytosterols and phytostanols in cholesterol lowering appears to be related to whether the individuals’ inherent physiologic tendencies to “hyper-synthesise” cholesterol in the liver or “hyperabsorb” cholesterol via the small intestine. Individuals who are ‘hypersynthesizers” of cholesterol tend to have a good reduction in plasma low-density lipoprotein cholesterol (LDLc) in response to statin therapy. Conversely, “hyper-absorbers” of cholesterol show a greater LDLc lowering in response to phytosterols or phytostanols. The ratios of cholestanol to cholesterol and lathosterol to cholesterol are good biomarkers of intestinal absorption of cholesterol and hepatic cholesterol synthesis. Animal data and human observational data suggest that phytosterols and phytostanols may have anti-atherosclerotic activities, e.g. reduction of the formation of nitric oxide, antagonism to the formation of LDL aggregates and plaque formation. The absence of cardiovascular outcome trials using phytosterol or phytostanol supplementation, makes it difficult to confirm a wider use in clinical practice, especially with the rapidly expanding list of effective and safe lipid-lowering medications
A new model of care for familial hypercholesterolaemia: What is the role of cardiology?
No full textFamilial hypercholesterolaemia (FH) is a co-dominantly inherited disorder that causes marked elevation in plasma cholesterol and premature coronary heart disease. There are at least 45,000 people with FH in Australia and New Zealand, but most remain undiagnosed and undertreated. To bridge this gap in coronary prevention the FH Australasia Network has developed a model of care for FH. We present the executive summary, with a commentary contrasting the recommendations with other international guidelines and highlighting the role of the cardiologist.Gerald F. Watts, David R. Sullivan, Frank M. van Bockxmeer, Nicola Poplawski, Ian Hamilton-Craig, Peter M. Clifton, Richard C. O’Brien, Warrick Bishop, Peter M. George, Christopher Semsarian, Andrew Tonkin for the Familial Hypercholesterolaemia Australasia Networ
Meiacanthus (Meiacanthus) geminatus Smith-Vaniz
No full textMeiacanthus (Meiacanthus) geminatus Smith-Vaniz The cardinal fish Chileodipterus zonatus Smith and Radcliffe is a remarkably similar appearing mimic of this species (Smith-Vaniz et al. 2001). The same color photograph of Meiacanthus vittatus given in Allen et al. (2003: 339) is here reproduced as Fig. 8. An excellent color photograph of this species also appears in Eichler and Myers (1997: 373). Two additional specimens of M. geminatus are available from Sabah, and agree well with Smith- Vaniz's (1987) expanded description of the species: WAM P. 30403 -006 (47.0 mm SL, female) and WAM P. 30409 - 0 0 4 (44.9 mm SL, male). The second author also observed this distinctive species at two additional locations at northeastern Kalimantan, Indonesia (2 ° 20.804 'N, 118 ° 11.031 'E and 1 ° 32.378 'N, 118 ° 23.443 'E) during a survey in 2003.Published as part of Smith-Vaniz, William F. & Allen, Gerald R., 2011, Three new species of the fangblenny genus Meiacanthus from Indonesia, with color photographs and comments on other species (Teleostei: Blenniidae: Nemophini), pp. 39-58 in Zootaxa 3046 on page 45, DOI: 10.5281/zenodo.27887
A model of care for familial hypercholesterolaemia: key role for clinical biochemistry
No full textFamilial hypercholesterolaemia (FH) is a dominantly inherited disorder present from birth that causes marked elevation in plasma low-density lipoprotein (LDL) cholesterol concentrations and premature coronary heart disease. There are at least 45,000 people with FH in Australia and New Zealand, but most remain unrecognised and those diagnosed remain inadequately treated. To bridge this gap in coronary prevention the FH Australasia Network has developed a model of care for FH. An executive summary of the model of care is presented, with a commentary on its recommendations and the key role of the clinical biochemistry laboratory.Gerald F. Watts, David R. Sullivan, Frank M. van Bockxmeer, Nicola Poplawski, Ian Hamilton-Craig, Peter M. Clifton, Richard C. O’Brien, Peter M. George and John R. Burnett for the Familial Hypercholesterolaemia Australasia Networ
The cost-effectiveness of coronary calcium score-guided statin therapy initiation for Australians with family histories of premature coronary artery disease
No full textObjectives: To compare the cost-effectiveness of coronary artery calcium (CAC) score-guided statin therapy criteria and American College of Cardiology/American Heart Association (ACC/AHA) guidelines (10-year pooled cohort equation [PCE] risk ≥ 7.5%) with selection according to Australian guidelines (5-year absolute cardiovascular disease risk [ACVDR] ≥ 10%), for people with family histories of premature coronary artery disease. Study design, setting: Markov microsimulation state transition model based on data from the Coronary Artery calcium score: Use to Guide management of Hereditary Coronary Artery Disease (CAUGHT-CAD) trial and transition probabilities derived from published statin prescribing and adherence outcomes and clinical data. Participants: 1083 people with family histories of premature coronary artery disease but no symptomatic cardiovascular disease. Main outcome measures: Relative cost-effectiveness over fifteen years, from the perspective of the Australian health care system, compared with usual care (Australian guidelines), assessed as incremental cost-effectiveness ratios (ICERs), with a notional willingness-to-pay threshold of 33 108 (CAC ≥ 100) and 909 241 per QALY gained) was not cost-effective. CAC score-guided selection (CAC ≥ 100) was cost-effective for people with 5-year ACVDR of at least 5%. Conclusion: Expanding the number of people at low to intermediate CVD risk eligible for statin therapy should selectively target people with subclinical atherosclerosis identified by CAC screening. This approach can be more cost-effective than simply lowering treatment eligibility thresholds.Prasanna Venkataraman, Amanda L Neil, Geoffrey K Mitchell, Tony Stanton, Stephen Nicholls, Andrew M Tonkin, Gerald F Watts, Thomas H Marwic
Static and Rotordynamic Characteristics of Liquid Annular Seals with a Circumferentially-Grooved Stator and Smooth Rotor using Three Levels of Circumferential Inlet-Fluid Rotation
No full textOriginal Equipment Manufacturers (OEMs) increase pump efficiency by reducing process fluid leakage from high-pressure stages into low-pressure ones. Smooth, liquid annular seals are used between pump stages to achieve this goal. In an effort to reduce leakage, OEMs sometimes machine circumferential grooves in the stators of annular liquid seals. Unfortunately, grooved seals do more than improve pump efficiency; they sometimes help degrade the system’s (pump, motor) rotordynamics, causing adverse effects that overshadow its helpful qualities. The rotordynamic community recognizes that fluid rotating in the shaft direction, at the entrance of the seal, is a source instability. The relevant literature lacks test results showing how high levels of inlet-fluid rotation affect a grooved seal’s performance, and how this effect changes as the shaft operates very close to the stator. The present study addresses this lack. Supplied with VG2 oil @ 46 ⁰C (115 ⁰F), the grooved seal used for this investigation has a length-to-diameter ratio L/D of 0.5, and a minimum radial clearance Cr of 203 ?m (8 mil). It features 15 circumferential grooves with a length Gl, and depth Gd of 1.52 mm (60 mils), which are equally-spaced by a land length of 1.52 mm (60 mils). The experimenter conducts tests at shaft angular speeds w of 2, 4, and 6 krpm, eccentricity ratios e0 of 0.00, 0.27, 0.53, and 0.80, and axial pressure drops ?P of 2.1, 4.1, 6.2, 8.3 bar (30, 60, 90, 120 PSI). Using 3 distinct inlet-fluid rotation inserts, the author induces increasing levels of circumferential fluid velocity at the seal’s inlet. Pre-swirl ratio (PSR) and outlet swirl ratio (OSR) are defined as the ratio of circumferential velocity at the seal’s inlet and outlet, respectively, to the rotor’s tangential surface velocity. To assess the seal’s static performance, the author measures leakage rate Q, eccentricity ratio e0, PSR, and OSR. To assess the seal’s dynamic performance, the author measures stator-rotor relative displacement, stator acceleration, and dynamic excitations. The author uses the dynamic measurements to calculate the seal’s rotordynamic coefficients and Whirl Frequency Ratio (WFR). Finally, the author calculates effective stiffness and damping coefficients to compare the grooved seal’s rotordynamic performance to that of a smooth seal with the same Cr, L/D, and operating conditions. In regards to static performance, the grooved seal’s leakage rate ranges from a low 15.64 LPM (4.13 GPM) at w = 6 krpm, and ?P = 2 bar (30 PSI), to a high 56.36 LPM (14.16 GPM) at w = 2 krpm, and ?P = 8 bar (120 PSI). When compared to the smooth seal, the grooved seal provides a 20% Q reduction at w = 2 krpm, and a 6% reduction at w = 6 krpm. Test results show all of the smooth seal’s rotordynamic coefficients increase markedly for e0 > 0.50, while those of the grooved seal generally remain unchanged through the entire eccentricity range. In essence, the grooves eliminate the seal’s dependency on eccentricity. Next, the grooved seal generally produces lower-magnitude cross-coupled stiffness and damping coefficient values than the smooth seal. Furthermore, the only positive effective stiffness values arise from the smooth seal operating at w = 2 krpm. The smooth seal consistently produces higher Keff than the grooved seal. Specifically, the smooth seal’s effective stiffness is higher than that of the grooved seal by at least 30% at w = 6 krpm, across the ?P range, for e0 = 0.00. Also, the grooved seal’s measured OSR is lower than that of the smooth seal by at least 10%, across the test matrix, suggesting that the grooves effectively slow down circumferential flow. For the grooved seal, the test program measures PSR values ranging from ?0 to 0.98, and OSR values bounded between 0.21 and 0.34. At w = 2 krpm, increasing PSR across its range reduces the grooved seal’s direct stiffness and damping, drives its cross-coupled stiffness and damping away from zero, increases its whirl frequency ratio (WFR) from ?0 to 0.8, and reduces its effective damping by a factor of approximately 3.5 when operating at ?P = 8.3 bar [120 PSI]. In general, the smooth seal produces larger effective stiffness and damping coefficients than the grooved seal, highlighting the grooves’ adverse effect on seal rotordynamics. Using XLCGvr, a code that calculates Q and rotordynamic coefficients for centered, circumferentially-grooved annular seals, the author performs a measurement-vs.-prediction comparison. The code over predicts Q by at least 15%. The stiffness, damping, and virtual mass coefficients are all under predicted by at least 50%. While the author used the code’s default empirical parameters, modifying them could have improved its accuracy
- …
