Experimental testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror

This report presents testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror. This mirror was designed to be the first mirror for the new soft X-ray beamlines to be built as part of the Advanced Light Source Upgrade. Test activities focused on fracture, heat transfer, modal response and distortion, and indicated that the mirror functions as intended.

169 Clinical Outcomes of Radial Head Arthroplasty as Primary Treatment for Post-traumatic Mason Type 3 and 4 Fractures: A Long-term Follow-up

Aim

Radial head arthroplasty (RHA) is the favoured treatment for complex radial head fractures, enabling functional restoration of elbow kinematics. However, study of long-term outcomes associated with RHA is largely neglected. This study aimed to fill the gap in the literature by firstly, assessing functional outcomes, and secondly, determining complications and rates of revision and/or removal of prosthesis associated with RHA, at our district general hospital.

Method

We retrospectively reviewed a consecutive single-surgeon series of patients receiving RHA as primary treatment for radial head fractures graded either 3 or 4 according to the Mason-Johnston classification between 2004 and 2009. Function at final follow-up was assessed using Quick Disabilities of the Arm, Shoulder and Hand (q-DASH) score and Mayo Elbow Performance Score (MEPS).

Results

16 patients identified; 12 available for final follow-up. Mean follow-up time of 12.60 years (range: 10.67-16.08). Mean q-DASH score of 8.2 (range: 0-34.1). Mean MEPS of 85.83 (range: 50-100) with 11 (91.67%) reporting excellent/good results. All complications occurred within the first year post-operatively. Stiffness was the most common (50%) complication, but additional procedures improved objective range of movement in affected patients. Only one patient required implant revision throughout follow-up, which was due to prosthesis subluxation in the first month.

Conclusions

This study is amongst the first to examine clinical outcomes associated with RHA with an average follow-up >12 years. Our results emphasise good functional restoration and low implant failure rate. Regular follow-up particularly in the early post-operative period is essential in detecting and resolving complications.

Widespread skeptic attitudes among people with epilepsy toward generic antiseizure drugs - A Swedish survey study

PURPOSE

To explore associations between the characteristics of people with epilepsy (PWE) and their attitudes toward generic substitution of antiseizure drugs (ASDs) in epilepsy.

METHODS

This was a cross-sectional survey study directed at adults with epilepsy using selected brand drugs: Keppra®, Lamictal®, Lyrica® or Topimax®. Symptoms of anxiety and depression, sense of self-efficacy, and beliefs about medicines were assessed. Caregivers were asked to answer for persons with intellectual or communicative difficulties.

RESULTS

The total response rate was 41% (n = 178). Almost half (46%) of subjects stated that they would oppose generic substitution (Gen-NEG) if suggested by their neurologist, while 71% would worry about adverse effects and/or increased seizure frequency after a putative switch. Age ≥50 increased the odds of being Gen-NEG (adjusted OR: 2.20, 95% CI: 1.18-4.11). Negative associations with both Gen-NEG and worriers were found for education level of high-school diploma or above, employment/studies, and prior experience of generic ASD switch. The proportion of worriers was much higher among caregivers (21/22) compared to subjects with epilepsy (106/156).

CONCLUSION

High proportions of PWE express concerns regarding generic substitution of ASDs. The elderly and caregivers seem to express particular concerns. Identifying ways to diminish negative outcomes and worries in connection with a switch is an important future field of research in order to ensure high quality, cost-effective health care for the most vulnerable people in our societies.

Building global development strategies for cf therapeutics during a transitional cftr modulator era

As CFTR modulator therapy transforms the landscape of cystic fibrosis (CF) care, its lack of uniform access across the globe combined with the shift towards a new standard of care creates unique challenges for the development of future CF therapies. The advancement of a full and promising CF therapeutics pipeline remains a necessary priority to ensure maximal clinical benefits for all people with CF. It is through collaboration across the global CF community that we can optimize the evaluation and approval process of new therapies. To this end, we must identify areas for which harmonization is lacking and for which efficiencies can be gained to promote ethical, feasible, and credible study designs amidst the changing CF care landscape. This article summarizes the counsel from core advisors across multiple international regions and clinical trial networks, developed during a one-day workshop in October 2019. The goal of the workshop was to identify, in consideration of the highly transitional era of CFTR modulator availability, the drug development areas for which global alignment is currently uncertain, and paths forward that will enable advancement of CF therapeutic development.

Effects of Aryl Hydrocarbon Receptor Deficiency on PCB-77-Induced Impairment of Glucose Homeostasis during Weight Loss in Male and Female Obese Mice

BACKGROUND

Lipophilic polychlorinated biphenyls (PCBs) accumulate with obesity, but during weight loss, liberated PCBs act as ligands of the aryl hydrocarbon receptor (AhR) to negatively influence health. Previous studies demonstrated that PCB-77 administration to obese male mice impaired glucose tolerance during weight loss. Recent studies indicate higher toxic equivalencies of dioxin-like PCBs in exposed females than males.

OBJECTIVES

We compared effects of PCB-77 on weight gain or loss and glucose homeostasis in male vs. female mice. We defined effects of AhR deficiency during weight gain or loss in male and female mice exposed to PCB-77.

METHODS

Study design was vehicle (VEH) or PCB-77 administration while fed a high-fat (HF) diet for 12 wk, followed by weight loss for 4 wk. The following groups were examined: male and female C57BL/6 mice administered VEH or PCB-77, female [Formula: see text] and [Formula: see text] mice administered VEH or PCB-77, and male [Formula: see text] and [Formula: see text] mice administered PCB-77. Glucose tolerance was quantified during weight gain (week 11) and loss (week 15); liver and adipose AhR and IRS2 (insulin receptor substrate 2) mRNA abundance, and PCB-77 concentrations were quantified at week 16.

RESULTS

PCB-77 attenuated development of obesity in females but not males. During weight loss, PCB-77 impaired glucose tolerance of males. AhR-deficient females (VEH) were resistant to diet-induced obesity. Compared with VEH-treated mice, HF-fed [Formula: see text] females treated with PCB-77 has less weight gain, and [Formula: see text] females had greater weight gain. During weight loss, [Formula: see text] females but not [Formula: see text] males treated with PCB-77 exhibited impaired glucose tolerance. In [Formula: see text] females administered PCB-77, IRS2 mRNA abundance was lower in adipose tissue compared with VEH-treated mice.

CONCLUSION

Male and female mice responded differently to PCB-77 and AhR deficiency in body weight (BW) regulation and glucose homeostasis. AhR deficiency reversed PCB-77-induced glucose impairment of obese males losing weight but augmented glucose intolerance of females. These results demonstrate sex differences in PCB-77-induced regulation of glucose homeostasis of mice. https://doi.org/10.1289/EHP4133.

Abstract 519: Mineralocorticoid Receptor Agonists and Salt Induce Aortic Aneurysms in C57BL/6 Mice

In an independent study in which we used 10-12 month old male C57BL/6 mice to investigate deoxycorticosterone Acetate (DOCA) and salt (1% saline) induced hypertension, we unexpectedly found that a numbers of mice died of aortic aneurysm rupture. Since aortic aneurysm affects 4-8% elderly men and elevated plasma aldosterone (ALDO) concentrations in patients have been linked to a spectrum of cardiovascular diseases, we therefore tested the possibility that activation of the mineralocorticoid receptor (MR) by DOCA and salt may be involved in aortic aneurysm formation. We reported here that that administration of 10-month-old male C57BL/6 mice with DOCA and salt, but neither DOCA nor salt alone, potently induced abdominal aortic aneurysm (AAA, 62%), thoracic aortic aneurysm (TAA, 44%), and aortic rupture (18%). ALDO and salt also induced similar high rates of AAA (58%), TAA (50%), and aortic rupture (42%). Histological and immunohistological examinations of cross-sections of AAA and TAA at the elastin degradation site demonstrated that DOCA and salt or ALDO and salt induced aortic aneurysm resembled human aortic aneurysm with respect to elastin degradation, macrophage infiltration, smooth muscle cell degeneration and apoptosis, and oxidative stress. Moreover, DOCA and salt also induced aortic aneurysm in 10-week-old mice but with lower incidence and less severe than that in 10-month-old mice. Interestingly, aortic aneurysm formation did not correlate with the increase in blood pressure induced by DOCA and salt. Systemic administration of the angiotensin converting enzyme inhibitor, enalapril, or angiotensin type 1 receptor antagonist, losartan, did not affect DOCA and salt-induced aortic aneurysm. In contrast, the MR antagonist spironolactone significantly attenuated DOCA and salt induced aortic aneurysm. In summary, our study describes a novel aortic aneurysm animal model induced by MR agonist and high salt, and reveals a previously unrecognized but potentially significant role of aldosterone in the pathogenesis of aortic aneurysm. These findings imply that MR antagonists may be effective in the treatment of some aortic aneurysms.

Guided self-help concreteness training as an intervention for major depression in primary care: a Phase II randomized controlled trial

BACKGROUND

The development of widely accessible, effective psychological interventions for depression is a priority. This randomized trial provides the first controlled data on an innovative cognitive bias modification (CBM) training guided self-help intervention for depression.

METHOD

One hundred and twenty-one consecutively recruited participants meeting criteria for current major depression were randomly allocated to treatment as usual (TAU) or to TAU plus concreteness training (CNT) guided self-help or to TAU plus relaxation training (RT) guided self-help. CNT involved repeated practice at mental exercises designed to switch patients from an unhelpful abstract thinking habit to a helpful concrete thinking habit, thereby targeting depressogenic cognitive processes (rumination, overgeneralization).

RESULTS

The addition of CNT to TAU significantly improved depressive symptoms at post-treatment [mean difference on the Hamilton Rating Scale for Depression (HAMD) 4.28, 95% confidence interval (CI) 1.29-7.26], 3- and 6-month follow-ups, and for rumination and overgeneralization post-treatment. There was no difference in the reduction of symptoms between CNT and RT (mean difference on the HAMD 1.98, 95% CI -1.14 to 5.11), although CNT significantly reduced rumination and overgeneralization relative to RT post-treatment, suggesting a specific benefit on these cognitive processes.

CONCLUSIONS

This study provides preliminary evidence that CNT guided self-help may be a useful addition to TAU in treating major depression in primary care, although the effect was not significantly different from an existing active treatment (RT) matched for structural and common factors. Because of its relative brevity and distinct format, it may have value as an additional innovative approach to increase the accessibility of treatment choices for depression.

Frequency of abdominal wall hernias: is classical teaching out of date?

Objectives

Abdominal wall hernias are common. Various authors all quote the following order (in decreasing frequency): inguinal, femoral, umbilical followed by rarer forms. But are these figures outdated? We investigated the epidemiology of hernia repair (retrospective review) over 30 years to determine whether the relative frequencies of hernias are evolving.

Design

All hernia repairs undertaken in consecutive adult patients were assessed. Data included: patient demographics; hernia type; and operation details. Data were analysed using Microsoft Excel 2007 and SPSS.

Setting

A single United Kingdom hospital trust during three periods: 1985–1988; 1995–1998; and 2005–2008.

Main outcome measures

Frequency data of different hernia types during three time periods, patient demographic data.

Results

Over the three time periods, 2389 patients underwent 2510 hernia repairs (i.e. including bilateral and multiple hernias in a single patient). Inguinal hernia repair was universally the commonest hernia repair, followed by umbilical, epigastric, para-umbilical, incisional and femoral, respectively. Whereas femoral hernia repair was the second commonest in the 1980s, it had become the fifth most common by 2005–2008. While the proportion of groin hernia repairs has decreased over time, the proportion of midline abdominal wall hernias has increased.

Conclusion

The current relative frequency of different hernia repair type is: inguinal; umbilical; epigastric; incisional; para-umbilical; femoral; and finally other types e.g. spigelian. This contrasts with hernia incidence figures quoted in common reference books.

Adaptive induction of NF-E2-related factor-2-driven antioxidant genes in endothelial cells in response to hyperglycemia

Hyperglycemia in diabetes mellitus promotes oxidative stress in endothelial cells, which contributes to development of cardiovascular diseases. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor activated by oxidative stress that regulates expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes. This study was designed to elucidate the homeostatic role of adaptive induction of Nrf2-driven free radical detoxification mechanisms in endothelial protection under diabetic conditions. Using a Nrf2/antioxidant response element (ARE)-driven luciferase reporter gene assay we found that in a cultured coronary arterial endothelial cell model hyperglycemia (10-30 mmol/l glucose) significantly increases transcriptional activity of Nrf2 and upregulates the expression of the Nrf2 target genes NQO1, GCLC, and HMOX1. These effects of high glucose were significantly attenuated by small interfering RNA (siRNA) downregulation of Nrf2 or overexpression of Keap-1, which inactivates Nrf2. High-glucose-induced upregulation of NQO1, GCLC, and HMOX1 was also prevented by pretreatment with polyethylene glycol (PEG)-catalase or N-acetylcysteine, whereas administration of H(2)O(2) mimicked the effect of high glucose. To test the effects of metabolic stress in vivo, Nrf2(+/+) and Nrf2(-/-) mice were fed a high-fat diet (HFD). HFD elicited significant increases in mRNA expression of Gclc and Hmox1 in aortas of Nrf2(+/+) mice, but not Nrf2(-/-) mice, compared with respective standard diet-fed control mice. Additionally, HFD-induced increases in vascular ROS levels were significantly greater in Nrf2(-/-) than Nrf2(+/+) mice. HFD-induced endothelial dysfunction was more severe in Nrf2(-/-) mice, as shown by the significantly diminished acetylcholine-induced relaxation of aorta of these animals compared with HFD-fed Nrf2(+/+) mice. Our results suggest that adaptive activation of the Nrf2/ARE pathway confers endothelial protection under diabetic conditions.

Resveratrol confers endothelial protection via activation of the antioxidant transcription factor Nrf2

Epidemiological studies suggest that Mediterranean diets rich in resveratrol are associated with reduced risk of coronary artery disease. Resveratrol was also shown to confer vasoprotection in animal models of type 2 diabetes and aging. However, the mechanisms by which resveratrol exerts its antioxidative vasculoprotective effects are not completely understood. Using a nuclear factor-E(2)-related factor-2 (Nrf2)/antioxidant response element-driven luciferase reporter gene assay, we found that in cultured coronary arterial endothelial cells, resveratrol, in a dose-dependent manner, significantly increases transcriptional activity of Nrf2. Accordingly, resveratrol significantly upregulates the expression of the Nrf2 target genes NAD(P)H:quinone oxidoreductase 1, gamma-glutamylcysteine synthetase, and heme oxygenase-1. Resveratrol treatment also significantly attenuated high glucose (30 mM)-induced mitochondrial and cellular oxidative stress (assessed by flow cytometry using MitoSox and dihydroethidine staining). The aforementioned effects of resveratrol were significantly attenuated by the small interfering RNA downregulation of Nrf2 or the overexpression of Kelch-like erythroid cell-derived protein 1, which inactivates Nrf2. To test the effects of resveratrol in vivo, we used mice fed a high-fat diet (HFD), which exhibit increased vascular oxidative stress associated with an impaired endothelial function. In HFD-fed Nrf2(+/+) mice, resveratrol treatment attenuates oxidative stress (assessed by the Amplex red assay), improves acetylcholine-induced vasodilation, and inhibits apoptosis (assessed by measuring caspase-3 activity and DNA fragmentation) in branches of the femoral artery. In contrast, the aforementioned endothelial protective effects of resveratrol were diminished in HFD-fed Nrf2(-/-) mice. Taken together, our results indicate that resveratrol both in vitro and in vivo confers endothelial protective effects which are mediated by the activation of Nrf2.

Comparison of the MMSE and RUDAS cognitive screening tools in an elderly inpatient population in everyday clinical use

We compared test score and performance times of Folstein's Mini Mental State Examination (MMSE) and the Rowland Universal Dementia Assessment Scale (RUDAS). Forty-six patients were recruited. The mean score was 20.6 for the MMSE and 20.5 for the RUDAS. Linear regression analysis revealed an r value of 0.83 (P < 0.05). The mean performance time was 9.4 min for both the MMSE and the RUDAS. Patient satisfaction was similar for both tests. Surveyed clinicians preferred the MMSE because of greater familiarity. We concluded that the RUDAS correlates well with the MMSE and is no more time-consuming to perform. It has good clinical utility as a cognitive screening tool.

Buttock cellulitis as a presentation of psoas abscess: a clinical reminder

Cellulitis is a common condition that is frequently managed by the general physicians on an acute medical take. This case report describes buttock cellulitis as a presentation of an iliopsoas abscess and illustrates the importance of considering a deep abscess when there are atypical features, when the cellulitis is in an unusual location or when the patient fails to improve with standard anti-microbial therapy.

Resveratrol induces mitochondrial biogenesis in endothelial cells

Pathways that regulate mitochondrial biogenesis are potential therapeutic targets for the amelioration of endothelial dysfunction and vascular disease. Resveratrol was shown to impact mitochondrial function in skeletal muscle and the liver, but its role in mitochondrial biogenesis in endothelial cells remains poorly defined. The present study determined whether resveratrol induces mitochondrial biogenesis in cultured human coronary arterial endothelial cells (CAECs). In CAECs resveratrol increased mitochondrial mass and mitochondrial DNA content, upregulated protein expression of electron transport chain constituents, and induced mitochondrial biogenesis factors (proliferator-activated receptor-coactivator-1alpha, nuclear respiratory factor-1, mitochondrial transcription factor A). Sirtuin 1 (SIRT1) was induced, and endothelial nitric oxide (NO) synthase (eNOS) was upregulated in a SIRT1-dependent manner. Knockdown of SIRT1 (small interfering RNA) or inhibition of NO synthesis prevented resveratrol-induced mitochondrial biogenesis. In aortas of type 2 diabetic (db/db) mice impaired mitochondrial biogenesis was normalized by chronic resveratrol treatment, showing the in vivo relevance of our findings. Resveratrol increases mitochondrial content in endothelial cells via activating SIRT1. We propose that SIRT1, via a pathway that involves the upregulation of eNOS, induces mitochondrial biogenesis. Resveratrol induced mitochondrial biogenesis in the aortas of type 2 diabetic mice, suggesting the potential for new treatment approaches targeting endothelial mitochondria in metabolic diseases.

The population-based prevalence of achondroplasia and thanatophoric dysplasia in selected regions of the US

There have been no large population-based studies of the prevalence of achondroplasia and thanatophroic dysplasia in the United States. This study compared data from seven population-based birth defects monitoring programs in the United States. We also present data on the association between older paternal age and these birth defects, which has been described in earlier studies. The prevalence of achondroplasia ranged from 0.36 to 0.60 per 10,000 livebirths (1/27,780-1/16,670 livebirths). The prevalence of thanatophoric dysplasia ranged from 0.21 to 0.30 per 10,000 livebirths (1/33,330-1/47,620 livebirths). In Texas, fathers that were 25-29, 30-34, 35-39, and > or =40 years of age had significantly increased rates of de novo achondroplasia among their offspring compared with younger fathers. The adjusted prevalence odds ratios were 2.8 (95% CI; 1.2, 6.7), 2.8 (95% CI; 1.0, 7.6), 4.9 (95% CI; 1.7, 14.3), and 5.0 (95% CI; 1.5, 16.1), respectively. Using the same age categories, the crude prevalence odds ratios for de novo cases of thanatophoric dysplasia in Texas were 5.8 (95% CI; 1.7, 9.8), 3.9 (95% CI; 1.1, 6.7), 6.1 (95% CI; 1.6, 10.6), and 10.2 (95% CI; 2.6, 17.8), respectively. These data suggest that thanatophoric dysplasia is one-third to one-half as frequent as achondroplasia. The differences in the prevalence of these conditions across monitoring programs were consistent with random fluctuation. Birth defects monitoring programs may be a good source of ascertainment for population-based studies of achondroplasia and thanatophoric dysplasia, provided that diagnoses are confirmed by review of medical records.

Interaction of apolipoprotein AIV with cholecystokinin on the control of food intake

Apolipoprotein AIV (apo AIV) and cholecystokinin (CCK) are peptides that act both peripherally and centrally to reduce food intake by decreasing meal size. The present study examined the effects of intraperitoneally administered bolus doses of recombinant apo AIV, CCK-8, and a combination of subthreshold doses of apo AIV and CCK on 4-h food intake in rats that were fasted overnight. Apo AIV at 100 μg/kg reduced food intake significantly relative to the saline control for 1 h, as did doses of CCK-8 at or above 0.125 μg/kg. Doses of apo AIV (50 μg/kg) or CCK (0.06 μg/kg) alone had no effect on food intake. However, when these subthreshold doses of apo AIV and CCK were administered together, the combination produced a significant inhibition of food intake relative to saline controls ( P < 0.001), and the duration of the effect was longer than that caused by the administration of either apo AIV or CCK alone. The satiation effect produced by CCK-8 + apo AIV was attenuated by lorglumide, a CCK1 receptor antagonist. We conclude that, whereas the intraperitoneal administration of doses of either recombinant apo AIV or CCK at or above threshold levels reduces food intake, the coadministration of subthreshold doses of the two peptides is highly satiating and works via CCK1 receptor.

Bacterial expression and characterization of rat apolipoprotein E

Apolipoprotein (apo) E is a protein involved in both lipid metabolism and neuroprotection. Recently, it has been suggested that apoE may play a role in the regulation of food intake and body weight in rodents. However, rodent plasma apoE is difficult to purify in reasonable amounts due to numerous time-consuming steps. To circumvent this, we created a bacterial expression system for the efficient production of large amounts of rat apoE. We inserted rat apoE DNA into the pET30 expression vector and overexpressed the proteins in Escherichia coli strain BL21 (DE3). A histidine tag present at the N-terminus allowed for easy purification of the recombinant protein. The tag was removed with an IgA protease (Igase) from Neisseria gonorrhoeae leaving the mature form of the protein. The use of Igase was important as several more common proteases routinely cleave apolipoproteins at undesired sites. The recombinant protein was then compared both structurally and functionally to rat plasma apoE. This expression system will be highly useful for probing the ability of rat apoE to mediate food intake in rats.

The biotin-capture lipid affinity assay: a rapid method for determining lipid binding parameters for apolipoproteins

The lipid affinity of plasma apolipoproteins is an important modulator of lipoprotein metabolism. Mutagenesis techniques have been widely used to modulate apolipoprotein lipid affinity for studying biological function, but the approach requires rapid and reliable lipid affinity assays to compare the mutants. Here, we describe a novel method that measures apolipoprotein binding to a standardized preparation of small unilamellar vesicles (SUVs) containing trace biotinylated and fluorescent phospholipids. After a 30 min incubation at various apolipoprotein concentrations, vesicle-bound protein is rapidly separated from free protein on columns of immobilized streptavidin in a 96-well microplate format. Vesicle-bound protein and lipid are eluted and measured in a fluorescence microplate reader for calculation of a dissociation constant and the maximum number of potential binding sites on the SUVs. Using human apolipoprotein A-I (apoA-I), apoA-IV, and mutants of each, we show that the assay generates binding constants that are comparable to other methods and is reproducible across time and apolipoprotein preparations. The assay is easy to perform and can measure triplicate binding parameters for up to 10 separate apolipoproteins in 3.5 h, consuming only 120 microg of apolipoprotein in total. The benefits and potential drawbacks of the assay are discussed.

Specific Sequences in the N and C Termini of Apolipoprotein A-IV Modulate Its Conformation and Lipid Association

Apolipoprotein (apoA-IV) is a 376-residue exchangeable apolipoprotein that may play a number of important roles in lipid metabolism, including chylomicron assembly, reverse cholesterol transport, and appetite regulation. In vivo, apoA-IV exists in both lipid-poor and lipid-associated forms, and the balance between these states may determine its function. We examined the structural elements that modulate apoA-IV lipid binding by producing a series of deletion mutants and determining their ability to interact with phospholipid liposomes. We found that the deletion of residues 333-343 strongly increased the lipid association rate versus native apoA-IV. Additional mutagenesis revealed that two phenylalanine residues at positions 334 and 335 mediated this lipid binding inhibitory effect. We also observed that residues 11-20 in the N terminus were required for the enhanced lipid affinity induced by deletion of the C-terminal sequence. We propose a structural model in which these sequences can modulate the conformation and lipid affinity of apoA-IV.

Structure of Human Apolipoprotein A-IV: A Distinct Domain Architecture among Exchangeable Apolipoproteins with Potential Functional Implications

Apolipoprotein A-IV (apoA-IV) is an exchangeable apolipoprotein that shares many functional similarities with related apolipoproteins such as apoE and apoA-I but has also been implicated as a circulating satiety factor. However, despite the fact that it contains many predicted amphipathic alpha-helical domains, relatively little is known about its tertiary structure. We hypothesized that apoA-IV exhibits a characteristic functional domain organization that has been proposed to define apoE and apoA-I. To test this, we created truncation mutants in a bacterial system that deleted amino acids from either the N- or C-terminal ends of human apoA-IV. We found that apoA-IV was less stable than apoA-I but was more highly organized in terms of its cooperativity of unfolding. Deletion of the extreme N and C termini of apoA-IV did not significantly affect the cooperativity of unfolding, but deletions past amino acid 333 on the C terminus or amino acid 61 on the N terminus had major destabilizing effects. Functionally, apoA-IV was less efficient than apoA-I at clearing multilamellar phospholipid liposomes and promoting ATP-binding cassette transporter A1-mediated cholesterol efflux. However, deletion of a C-terminal region of apoA-IV, which is devoid of predicted amphipathic alpha helices (amino acids 333-376) stimulated both of these activities dramatically. We conclude that the amphipathic alpha helices in apoA-IV form a single, large domain that may be similar to the N-terminal helical bundle domains of apoA-I and apoE but that apoA-IV lacks the C-terminal lipid-binding and cholesterol efflux-promoting domain present in these apolipoproteins. In fact, the C terminus of apoA-IV appears to reduce the ability of apoA-IV to interact with lipids and promote cholesterol efflux. This indicates that, although apoA-IV may have evolved from gene duplication events of ancestral apolipoproteins and shares the basic amphipathic helical building blocks, the overall localization of functional domains within the sequence is quite different from apoA-I and apoE.

Updated CCPS Investigation Guidelines book

Incident investigation standards and performance criteria continue to improve. In recognition, the Center for Chemical Process Safety (CCPS) undertook a major project to upgrade and update the Incident Investigation Guidelines originally published in 1992. These significantly expanded guidelines provide a practical resource for effective investigation of process-related incidents, and reflect changes in good practices and expectations of regulators. This paper highlights the content of the new guidelines with special emphasis on what is new and improved. Entirely new chapters address the topics of legal considerations, the near-miss event, and continuous improvement of the investigation system. The objective of the guidelines is to allow chemical process organizations to develop and implement an incident investigation management system that is effective in identifying underlying causes.

The early molecular response to imatinib predicts cytogenetic and clinical outcome in chronic myeloid leukaemia

Real-time quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) is increasingly used to monitor responses in chronic myeloid leukaemia (CML). The peripheral blood BCR-ABL/ABL ratio, as assessed by Q-RT-PCR, has been shown to correlate with the contemporary cytogenetic response in patients receiving imatinib (Glivec, Gleevec). We have used Q-RT-PCR to monitor the early molecular response to 4 weeks and 3 months of imatinib therapy, in 47 patients with established CML. After 4 weeks of imatinib therapy, patients whose BCR-ABL/ABL ratio had fallen to less than 50% that of baseline had a significantly higher probability of achieving a major cytogenetic response after 6 months of therapy, when compared with those whose ratio did not fall by this amount (P < 0.001). Similarly, patients whose ratio at 3 months was less than 10% of that at baseline had a significantly higher probability of achieving a major cytogenetic remission at 6 months (P < 0.001). Patients who achieved these falls in their BCR-ABL/ABL ratio at either 4 weeks or 3 months had a superior progression-free survival at a median follow-up of 16.5 months (P = 0.01 and 0.003 respectively). These effects were independent of patient age and disease stage. The occurrence of peripheral blood cytopenias sufficiently severe to interrupt therapy was unrelated to progression-free survival. In conclusion, the data suggest that the early trend in the BCR-ABL/ABL ratio may be clinically useful for the early identification of patients destined to fare poorly on imatinib.

Expression of biologically active rat apolipoprotein AIV in Escherichia coli

Rat apolipoprotein AIV (apo AIV) is a 43-kDa intestinal apolipoprotein that is important in lipid metabolism and the suppression of food intake. In this study, a full-length rat apo AIV was expressed in Escherichia coli and purified in a bioactive form. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometric analysis revealed that the isolated recombinant protein has a molecular mass of approximately 43 kDa, similar to that of natural rat apo AIV. Immunoblot analysis and N-terminal amino acid sequencing confirmed the identity of the recombinant apo AIV protein as natural rat apo AIV. The recombinant protein was functional in lipoprotein binding assays. Biological activity was assessed behaviorally in that the recombinant protein suppressed food intake of fasted rats comparably to natural rat apo AIV. Neither native nor recombinant apo AIV elicited a conditioned taste aversion (CTA) at doses that suppress feeding. These results indicate that the recombinant apo AIV is structurally and functionally indistinguishable from rat natural apo AIV, making this overexpression and purification scheme a powerful tool for future structure and function studies.

Serial monitoring of BCR-ABL by peripheral blood real-time polymerase chain reaction predicts the marrow cytogenetic response to imatinib mesylate in chronic myeloid leukaemia

Imatinib mesylate (trade name Glivec or Gleevec) is emerging as an important therapy in the management of chronic myeloid leukaemia (CML). It is clinically useful to monitor the cytogenetic response to imatinib, although frequent marrow examinations are inconvenient. We have used serial real-time reverse transcription-polymerase chain reaction (RT-PCR) to monitor the ratio of peripheral blood BCR-ABL to normal ABL transcripts in 43 patients receiving imatinib, and compared the results to concurrent conventional bone marrow (BM) cytogenetics. After 6 months of treatment, 13 cases were complete cytogenetic responders, defined as all BM metaphases negative for the Philadelphia (Ph) chromosome. In these patients, the BCR-ABL/ABL ratio was less than 0.08%. Six cases achieved a partial cytogenetic response (1-35% Ph-positive BM metaphases) and their BCR-ABL/ABL ratio was between 0.08 and 10%. In total, 24 cases were cytogenetic non-responders, and their BCR-ABL/ABL ratio exceeded 11%. The data suggested that the 6-month BCR-ABL/ABL ratio may reliably predict the contemporary marrow cytogenetic response. It was concluded that serial real-time RT-PCR may offer a convenient surrogate assessment of the marrow cytogenetic response to imatinib therapy in CML.

Motor systems

The field of motor control has broadened considerably over the past decade. Increasingly detailed information has accrued about the cellular and molecular processes involved in motor pattern generation and motor learning while, at the other extreme, the comparison of studies in humans and monkeys has begun to bridge the gap between cognitive and motor functions. The most striking feature of recent research has been the intense use of electrophysiological procedures in behaving monkeys and non-invasive imaging procedures in humans to elucidate details of sensory-motor transformations and the functional roles of different brain regions in the learning, planning and execution of movements.

Chimpanzee (Pan troglodytes) handedness: variability across multiple measures of hand use

This study examined intertask consistency in handedness across multiple measures of hand use in a sample of 187 chimpanzees (Pan troglodytes). Hand preferences for 2 to 6 measures were collected from the sample, and hand preference scores were derived on the basis of the individual hand preferences for each measure. Seven of 15 possible intratask correlations were significant, with some degree of clustering depending on the motor demands of the tasks. Two overall measures of handedness revealed population-level right-handedness in the chimpanzees, although the degree of bias was reduced for chimpanzees tested on more than 3 measures of hand use. The results are interpreted in the context of several recent studies that proposed theoretical models of handedness in nonhuman primates.