36 Feasibility of Resistance Exercise to Failure at Different Loads in Frail and Healthy Older Adults?

Introduction

Resistance training (RT) is the most effective way to increase muscle mass and function in older adults both with/without sarcopenia/frailty. In younger adults, when RT is performed to muscle failure the load lifted does not mediate the magnitude of response, but there are no studies in older adults. We aimed to determine the feasibility of recruitment to a RT intervention working to muscle failure at different loads in frail and healthy older adults.

Methods

We performed an 8-week randomised feasibility trial of lower limb RT to volitional muscular failure, at high and low load. Participants were recruited via hospital outpatient clinics and newspaper advertisements. Outcomes included: frailty assessment (Fried criteria); muscle strength (maximum voluntary contraction/one-repetition maximum); functional abilities (Short Physical Performance Battery); safety/adverse events were recorded via a log, and patient experiences from focus groups.

Results

110 people were assessed for eligibility, and 58 randomised (frail n = 6, prefrail n = 20, robust n = 32) to either high (n = 30) or low load (n = 28) groups. Mean age of participants was 72 years (range 65–93), 36 were female, 22 male. Session attendance was 95% (high load) and 90.4% (low load). Most participants were recruited via advertisements. All participants reported feeling safe and reassured in the RT sessions. Two participants had a serious adverse event, one related to RT (hypotension) and several had adverse events (three intervention-related). Pain was reported at both loads (high n = 9, low n = 8) yet all completed. There were no differences (P > 0.05) in effects of RT outcome variables between low and high load groups.

Conclusion

In this feasibility trial the recruitment of frail patients via clinics was limited. Performing supervised RT to muscle failure in older adults was safe/acceptable and the load at which RT was performed did not influence its efficacy. Future research into the effectiveness of such RT is warranted.

On-demand erythrocyte disposal and iron recycling requires transient macrophages in the liver

Iron is an essential component of the erythrocyte protein hemoglobin and is crucial to oxygen transport in vertebrates. In the steady state, erythrocyte production is in equilibrium with erythrocyte removal. In various pathophysiological conditions, however, erythrocyte life span is compromised severely, which threatens the organism with anemia and iron toxicity. Here we identify an on-demand mechanism that clears erythrocytes and recycles iron. We show that monocytes that express high levels of lymphocyte antigen 6 complex, locus C1 (LY6C1, also known as Ly-6C) ingest stressed and senescent erythrocytes, accumulate in the liver via coordinated chemotactic cues, and differentiate into ferroportin 1 (FPN1, encoded by SLC40A1)-expressing macrophages that can deliver iron to hepatocytes. Monocyte-derived FPN1(+)Tim-4(neg) macrophages are transient, reside alongside embryonically derived T cell immunoglobulin and mucin domain containing 4 (Timd4, also known as Tim-4)(high) Kupffer cells (KCs), and depend on the growth factor Csf1 and the transcription factor Nrf2 (encoded by Nfe2l2). The spleen, likewise, recruits iron-loaded Ly-6C(high) monocytes, but these do not differentiate into iron-recycling macrophages, owing to the suppressive action of Csf2. The accumulation of a transient macrophage population in the liver also occurs in mouse models of hemolytic anemia, anemia of inflammation, and sickle cell disease. Inhibition of monocyte recruitment to the liver during stressed erythrocyte delivery leads to kidney and liver damage. These observations identify the liver as the primary organ that supports rapid erythrocyte removal and iron recycling, and uncover a mechanism by which the body adapts to fluctuations in erythrocyte integrity.

Abstract 19: Deletion of Myeloid GSK3α Attenuates Atherosclerosis and Promotes an M2 Macrophage Phenotype

Objective: Glycogen synthase kinase (GSK)-3α/β has been implicated in the pathogenesis of diseases including diabetes, cancer, Alzheimer’s and atherosclerosis. The tissue and homolog specific functions of GSK3α and β in atherosclerosis are unknown. This study examines the effect of hepatocyte or myeloid cell specific deletion of GSK3α or GSK3β on atherosclerosis in LDLR-/- mice.

Approach and results: We ablated GSK3α or GSK3β expression in hepatic or myeloid cells of LDLR-/- mice and mice were fed a high fat diet for 10 weeks. GSK3α or GSK3β deficiency in hepatic or myeloid cells did not affect metabolic parameters, including plasma lipid levels. Hepatic deletion of GSK3α or GSK3β did not affect the development of atherosclerosis or hepatic lipid content. Myeloid deletion of GSK3α, but not GSK3β, reduced atherosclerotic lesion volume as well as lesion complexity. Mice lacking GSK3α in myeloid cells had a less inflammatory and more anti-inflammatory plasma cytokine profile. Macrophages within atherosclerotic lesions of myeloid GSK3α deficient mice, but not GSK3β deficient mice, displayed reduced expression of markers associated with M1 macrophage polarization and enhanced expression of the M2 markers. Finally, bone marrow derived macrophages were isolated and differentiated into classical M1 macrophages or alternative M2 macrophages in vitro. GSK3α deletion, but not GSK3β deletion, attenuated the expression of genes associated with M1 polarization while promoting the expression of genes associated with M2 polarization. Mechanistically, GSK3α regulated macrophage polarization by modulating the phosphorylation and activation of STAT transcription factors.

Conclusions: Our findings suggest that deletion of myeloid GSK3α attenuates the progression of atherosclerosis by regulating STAT activation and promoting an M2 macrophage phenotype.

Abstract 659: PKR-Like Endoplasmic Reticulum Kinase and Glycogen Synthase Kinase-3α/ß Signaling Regulates Endoplasmic Reticulum Stress-Induced Foam Cell Formation

Background: Evidence suggests a causative role for endoplasmic reticulum (ER) stress in the development of atherosclerosis. The molecular mechanisms by which conditions of ER stress promote pro-atherogenic processes are not understood. We have found that ER stress-inducing agents can activate glycogen synthase kinase (GSK)-3α/β, a protein involved in many metabolic pathways. The objective of this study is to investigate the role of GSK3α/β in pro-atherogenic ER stress signaling.

Methods and Results: Thp1-derived macrophages were treated with the ER stress-inducing agents, glucosamine, thapsigargin or palmitate, in the presence or absence of the GSK3α/β inhibitor CT99021. GSK3α/β inhibition did not affect the adaptive unfolded protein response (UPR), but did block ER stress-induced lipid accumulation as well as the up regulation of genes associated with lipid biosynthesis and uptake. Using small molecule inhibitors of specific UPR pathways, we found that PERK, but not IRE1 or ATF6, is required for the activation of GSK3α/β by ER stress. GSK3α/β inhibition attenuated ER stress-induced expression of distal components of the PERK pathway, including CHOP and ATF4. Atherosclerotic plaques from ApoE-/- mice, fed a diet supplemented with the GSK3α/β inhibitor valproate, had reduced levels of CHOP within the macrophage foam cells. In primary mouse macrophages PERK inhibition blocked ER stress induced lipid accumulation whereas the overexpression of constitutively active S9A-GSK3β promoted foam cell formation and CHOP expression, even in cells treated with a PERK inhibitor.

Conclusions: Pharmacological inhibition of GSK3α/β attenuates ER stress-induced lipid accumulation and macrophage foam cell formation. These findings indicate that GSK3α/β is an important factor in the ER stress-PERK signaling pathway and may play a central role in the pro-atherogenic dysregulation of lipid metabolism.

Abstract 79: Examining the Role of Endoplasmic Reticulum Stress Induced Glycogen Synthase Kinase-3a/ß in Accelerated Atherosclerosis

Introduction

Cardiovascular disease accounts for a third of all deaths in the western world, however our understanding of the molecular mechanisms of atherosclerosis development is incomplete. Our previous findings have suggested that endoplasmic reticulum (ER) stress plays a causative role in atherogenesis. The objective of this study is to investigate how ER stress promotes atherosclerosis with a specific focus on ER stress-induced Glycogen Synthase Kinase (GSK)-3α and β.

Methods and Results

Established mouse models of accelerated atherosclerosis including hyperglycemia, hyperhomocysteinemia and relative dyslipidemia in female ApoE-/- mice were examined. A subset of mice from each group was supplemented with valproate (625 mg/kg), a compound with GSK3α/β inhibitory properties. Hyperglycemia, hyperhomocysteinemia and high fat diet elevated ER stress levels in multiple tissues, enhanced GSK3β activity, increased atherosclerotic plaque size, and induced hepatic steatosis. Valproate-supplementation significantly attenuated GSK3 activation, aortic plaque development and hepatic steatosis without altering ER stress levels. ER stress and valproate appears to modulate GSK3 activity by altering its phosphorylation status.

To examine the mechanism linking ER stress to the activation of pro-atherogenic pathways, cultured THP1-derived macrophages were treated with the ER stress inducing agents, glucosamine (5mM), thapsigargin (1.5μM) or palmitate (800μM). GSK3α/β activity was inhibited with the specific inhibitor CT99021 (4μM). In macrophages, ER stress upregulated the mRNA expression of genes controlling lipid biosynthesis while GSK3α/β inhibition attenuated lipid synthesis. The expression of downstream targets of the PERK ER stress signaling pathway, CHOP and ATF4, were downregulated by GSK3α/β inhibition. Further, PERK-/- mouse embryonic fibroblasts (MEFs) had significantly attenuated lipid accumulation while expression of constitutively active GSK3β-S9A restored the ability of PERK deficient cells to accumulate lipids.

Conclusions

These findings support the a common pathway that links cardiovascular risk factors to the activationof pro-atherogenic pathways by a mechanism involving ER stress-induced GSK3α/β.

Combining child welfare and substance abuse services: a blended model of intervention

Montgomery County, Maryland's Child Welfare Services (CWS) and Adult Addiction Services (AAS) developed an initiative to address the requirements of the Adoption and Safe Families Act (ASFA) while meeting the needs of families and the community of providers. A blended model of intervention was determined to be the best strategy to achieve the dual mandates of CWS and alcohol and other drugs (AOD) providers. Drawing from criminal justice, systems theory, social work, and addiction treatment, the approach made use of graduated sanctions or levels of intensity in providing services, engaging client participation, and engendering motivation. This article proposes strategies at client and organizational levels to understand the process of adaptation to ASFA and to guide planning for blending services.

Medical complications after stroke: a multicenter study

BACKGROUND AND PURPOSE

This prospective, multicenter study was performed to determine the frequency of symptomatic complications up to 30 months after stroke using prespecified definitions of complications.

METHODS

We recruited 311 consecutive stroke patients admitted to hospital. Research nurses reviewed their progress on a weekly basis until hospital discharge and again at 6, 18, and 30 months after stroke.

RESULTS

Complications during hospital admission were recorded in 265 (85%) of stroke patients. Specific complications were as follows: neurological-recurrent stroke (9% of patients), epileptic seizure (3%); infections-urinary tract infection (24%), chest infection (22%), others (19%); mobility related-falls (25%), falls with serious injury (5%), pressure sores (21%); thromboembolism-deep venous thrombosis (2%), pulmonary embolism (1%); pain-shoulder pain (9%), other pain (34%); and psychological-depression (16%), anxiety (14%), emotionalism (12%), and confusion (56%). During follow-up, infections, falls, "blackouts, " pain, and symptoms of depression and anxiety remained common. Complications were observed across all 3 hospital sites, and their frequency was related to patient dependency and duration after stroke.

CONCLUSIONS

Our prospective cohort study has confirmed that poststroke complications, particularly infections and falls, are common. However, we have also identified complications relating to pain and cognitive or affective symptoms that are potentially preventable and may previously have been underestimated.

Recognition of facial expressions of emotion by persons with mental retardation. A matched comparison study

Children and adults with mental retardation were tested on their ability to recognize facial expressions of emotion. The sample consisted of 80 children and adults with mental retardation and a control group of 80 nonhandicapped children matched on mental age and gender. Ekman and Friesen's normed photographs of the six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) were used in a recognition task of facial expressions. Subjects were individually read two-sentence stories identifying a specific emotion, presented with a randomized array of the six photographs of the basic facial expressions of emotion, and then asked to select the photograph that depicted the emotion identified in the story. This procedure was repeated with 24 different stories, with each of the six basic emotions being represented four times. Results showed that, as a group, individuals with mental retardation were not as proficient as their mental-age-matched nonhandicapped control subjects at recognizing facial expressions of emotion. Although adults with mild mental retardation were more proficient at this task than those with moderate mental retardation, this finding was not true for children. There was a modest difference between the children with moderate mental retardation and their nonhandicapped matched controls in their ability to recognize facial expression of disgust.

Enhancing the ability of adults with mental retardation to recognize facial expressions of emotion

The ability to recognize accurately and respond appropriately to facial expressions of emotion is essential for interpersonal interaction. Individuals with mental retardation typically are deficient in these skills. The ability of 7 adults, 1 with severe and 6 with moderate mental retardation, to recognize facial expressions of emotion correctly was assessed. Then, they were taught this skill using a combination of a discrimination training procedure for differentiating facial movements, directed rehearsal, and Ekman and Friesen's "flashing photograph" technique. Their average increase in accuracy over baseline was at least 30% during the course of the training and over 50% during the last 5 days of the training phase. Further, these individuals were able to generalize their skills from posed photographs to videotaped role plays and were able to maintain their enhanced skills during the 8 to 9 months following the termination of training. This is the first study to show that individuals with mental retardation can be taught skills that enhance their ability to recognize facial expressions of emotion.

Recognition of facial expressions of emotion by persons with mental retardation

A sample of 511 children and adults with mental retardation or borderline intelligence (1 SD below the mean IQ) and children of average intelligence were tested on their ability to recognize the six basic facial expressions of emotion as they are exemplified in Ekman and Friesen's (1975) normed photographs. Each subject was shown four sets of six photographs, one of each emotion. Subjects were read 24 short stories; after each one they were asked to point to the photograph that depicted the emotion described. Children and adults with mental retardation or borderline intelligence were less proficient at identifying facial expressions of emotion than were children of average intelligence. Among individuals with mental retardation or borderline intelligence, recognition of accuracy of facial emotion increased with IQ. Among individuals with average intelligence, recognition accuracy increased with age.