Intra-islet glucagon signalling regulates beta-cell connectivity, first-phase insulin secretion and glucose homoeostasis

BACKGROUND

Type 2 diabetes (T2D) is characterised by the loss of first-phase insulin secretion. We studied mice with β-cell selective loss of the glucagon receptor (Gcgrfl/fl X Ins-1Cre), to investigate the role of intra-islet glucagon receptor signalling on pan-islet calcium activity and insulin secretion.

METHODS

Metabolic profiling was conducted on Gcgrβ-cell-/- and littermate controls. Crossing with GCaMP6f (STOP flox) animals further allowed for β-cell specific expression of a fluorescent calcium indicator. These islets were functionally imaged in vitro and in vivo. Wild-type mice were transplanted with islets expressing GCaMP6f in β-cells into the anterior eye chamber and placed on a high fat diet. Part of the cohort received a glucagon analogue (GCG-analogue) for 40 days and the control group were fed to achieve weight matching. Calcium imaging was performed regularly during the development of hyperglycaemia and in response to GCG-analogue treatment.

RESULTS

Gcgrβ-cell-/- mice exhibited higher glucose levels following intraperitoneal glucose challenge (control 12.7 mmol/L ± 0.6 vs. Gcgrβ-cell-/- 15.4 mmol/L ± 0.0 at 15 min, p = 0.002); fasting glycaemia was not different to controls. In vitro, Gcgrβ-cell-/- islets showed profound loss of pan-islet [Ca2+]I waves in response to glucose which was only partially rescued in vivo. Diet induced obesity and hyperglycaemia also resulted in a loss of co-ordinated [Ca2+]I waves in transplanted islets. This was reversed with GCG-analogue treatment, independently of weight-loss (n = 8).

CONCLUSION

These data provide novel evidence for the role of intra-islet GCGR signalling in sustaining synchronised [Ca2+]I waves and support a possible therapeutic role for glucagonergic agents to restore the insulin secretory capacity lost in T2D.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

The adoption of conservation practices in the Corn Belt: the role of one formal farmer network, Practical Farmers of Iowa

Substantial evidence has shown that involvement in peer-to-peer farming networks influences whether a farmer decides to try a new practice. Formally organized farmer networks are emerging as a unique entity that blend the benefits of decentralized exchange of farmer knowledge within the structure of an organization providing a variety of sources of information and forms of engagement. We define formal farmer networks as farmer networks with a distinct membership and organizational structure, leadership that includes farmers, and an emphasis on peer-to-peer learning. This study complements existing ethnographic research on the benefits of organized farmer networking by examining farmers in one longstanding formal farmer network, Practical Farmers of Iowa. Using a nested, mixed-method research design, we analyzed survey and interview data to understand how participation and forms of engagement in the network are associated with the adoption of conservation practices. Responses from 677 farmers from a regular member survey disseminated by Practical Farmers of Iowa in 2013, 2017, and 2020 were pooled and analyzed. GLM binomial and ordered logistic regression results indicate that greater participation in the network, particularly through in-person formats, has a strong and significant association with greater adoption of conservation practices. Logistic regression results show that building relationships in the network is the most important variable for predicting whether a farmer reported adopting conservation practices as a result of participation in PFI. In-depth interviews with 26 surveyed member farmers revealed that PFI supports farmers to adopt by providing information, resources, encouragement, confidence building, and reinforcement. In-person learning formats were more important to farmers relative to independent formats because they were able to have side conversations with other farmers, ask questions, and observe results. We conclude that formal networks are a promising way to expand the use of conservation practices, particularly through targeted efforts to increase relationship building in the network through face-to-face learning opportunities.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Bystander cardiopulmonary resuscitation for paediatric out-of-hospital cardiac arrest in England: An observational registry cohort study

INTRODUCTION

Bystander cardiopulmonary resuscitation (BCPR) is strongly advocated by resuscitation councils for paediatric out-of-hospital cardiac arrests (OHCAs). However, there are limited reports on rates of BCPR in children and its relationship with return of spontaneous circulation (ROSC) or survival outcomes.

OBJECTIVE

We describe the rate of BCPR and its association with any ROSC and survival- to- hospital-discharge.

METHODS

We conducted retrospective analysis of prospectively collected paediatric (<18 years of age) OHCA cases in England; we included specialist registry patients treated by emergency medical services (EMS) with known BCPR status and outcome between January 2014 and November 2018. Data included patient demographics, aetiology, witness status, initial rhythm, EMS, season, time of day and bystander status. Associations between BCPR, and any ROSC and survival-to-hospital-discharge outcomes were explored using multivariable logistic regression.

RESULTS

There were 2363 paediatric OHCAs treated across 11 EMS regions. BCPR was performed in 69.6% (1646/2363) of the cases overall (range 57.7% (206/367) to 83.7% (139/166) across EMS regions). Only 34.9% (550/1572) of BCPR cases were witnessed. Overall, any ROSC was achieved in 22.8% (523/2289) and survival to hospital discharge in 10.8% (225/2066). Adjusted odds ratio (aOR) for any ROSC was significantly improved following BCPR compared to no BCPR (aOR 1.37, 95% CI 1.03-1.81), but adjusted odds ratio for survival-to-hospital-discharge were similar (aOR 1.01, 95% CI 0.66-1.55).

CONCLUSIONS

BCPR was associated with improved rates of any ROSC but not survival-to-hospital-discharge. Variations in EMS BCPR rates may indicate opportunities for regional targeted increase in public BCPR education.

233 Blood Tests and Radiographs After Hip and Knee Arthroplasty – We May Not Always Need Them

Aim

Routine blood tests and radiographs are routinely performed after total joint arthroplasty as a pre-discharge requirement. This study aims to explore whether there might be sub-group of patients undergoing arthroplasty for whom post-operative blood tests and radiographs might not be mandated in the absence of clinical concern.

Method

A retrospective study of 612 ASA 1 and 2 patients underwent total hip or knee arthroplasty at a single orthopaedic centre. Variables purported to be of interest were sodium and Potassium levels, Haemoglobin concentration and eGFR. Return to theatre and alterations of the routine Physiotherapy rehabilitation were matched to post-operative radiographs.

Results

42 (6.9%) patients had post-operative haemoglobin below 10 g/L. Of these 4 were symptomatic, which required treatment. Acute kidney injury was identified in 13 patients (2.1%); 11 had pre-existing renal disease. The other two had both suffered pro-longed post-operative hypotension. Two patients had severe hyponatraemia and one of whom had pre-existing renal disease. Two patients had hypokalaemia and one of whom had metabolic syndrome but normalised within 24 hours after oral supplement. No patient had abnormal post-operative radiography that altered management.

Conclusions

Our study indicates that routine post-operative blood tests and radiographs may not be necessary in ASA 1 and 2 patients with normal pre-existing blood tests. Where patient is clinically symptomatic or there is evidence of pre-operative renal dysfunction, metabolic syndrome, electrolyte imbalance or anaemia, we would suggest blood tests are necessary. If there is no surgical concern, it is safe to delay check radiography until their first post-operative follow up.

Sapphire advanced mitigation process: wet etch to expose sub-surface damage and increase laser damage resistance and mechanical strength

A novel, to the best of our knowledge, method of wet chemical etching of sapphire workpieces (such as optics, wafers, windows, and cones), called the sapphire advanced mitigation process (or sapphire AMP), has been developed that exposes sub-surface mechanical damage created during the optical fabrication process and significantly enhances the surface laser damage resistance ($ \gt {2{\times}}$>2×) and mechanical strength (up to $\sim{2.6{\times}}$∼2.6×). Sapphire AMP involves first treating the workpiece with a mixture of sulfuric and phosphoric acid $([{\rm H_{2}{\rm SO_{4}}}]:[{\rm H_{3}{\rm PO_{4}}}]=1:3)$([H₂SO₄]:[H₃PO₄]=1:3) at 220°C, followed with phosphoric acid at 160°C, then with sodium hydroxide base (NaOH) and surfactant at 40°C, and finally with a high-pressure deionized water spray rinse. Sapphire AMP has been demonstrated on both A- and C-plane sapphire workpieces. The mechanism of this etch process involves the reaction of the sapphire $({\rm Al_{2}}{\rm O_{3}})$(Al₂O₃) surface with sulfuric acid $({\rm H_{2}}{\rm SO_{4}})$(H₂SO₄) forming aluminum sulfate $[{{\rm Al}_2}{({{\rm SO}_4})_3}]$[Al₂(SO₄)₃], which has low solubility. The high phosphoric acid content in the first and second steps of sapphire AMP results in the efficient conversion of ${{\rm Al}_2}{({{\rm SO}_4})_3}$Al₂(SO₄)₃ to aluminum phosphate $({\rm AlPO_{4}})$(AlPO₄), which is very soluble, greatly reducing reaction product redeposition on the workpiece surface. Sapphire AMP is shown to expose sub-surface mechanical damage on the sapphire surface created during the grinding and polishing processes, whose etched morphology has either isotropic or anisotropic evolution depending on the nature of the initial surface damage. Sapphire AMP was also designed to remove the key known surface, laser absorbing precursors (namely, foreign chemical impurities, the fracture surface layer of preexisting sub-surface damage, and reaction product or foreign species redeposition or precipitation). Static and sliding indention induced surface microfractures on sapphire are shown after sapphire AMP to have a significant decrease in the fast photoluminescence intensity (a known metric for measuring the degree of laser damaging absorbing precursors). In addition, the onset of laser damage (at 351 nm 3 ns) on sapphire AMP treated workpieces was shown to increase in fluence from $\sim{4}$∼4 to $ \gt {9}.{5}\;{{\rm J/cm}^2}$>9.5J/cm². Finally, biaxial ball-on-ring mechanical tests on sapphire disks showed an increase in the failure stress from 340 MPa (with pre-existing 28 µm flaws) to $\sim{900}\;{\rm MPa}$∼900MPa after sapphire AMP, which is attributed to the blunting of the surface microfractures.

The Gray Matters App Targeting Health Behaviors Associated with Alzheimer's Risk: Improvements in Intrinsic Motivation and Impact on Diet Quality and Physical Activity

OBJECTIVE

We examine if the Gray Matters intervention (education and behavioral self-monitoring app targeting lifestyle risks for Alzheimer's disease [AD]) affected participants' motivation for change and whether high motivation predicts improved diet and physical activity over 6 months.

DESIGN

In this 6-month randomized controlled trial (treatment n=104; control n=42; assessed pre/post intervention) amotivation, external regulation, identified regulation, and intrinsic motivation were assessed via the Situational Motivation Scale (SIMS). Diet quality was assessed via adherence to the DASH diet, and physical activity was assessed in minutes.

PARTICIPANTS

Eligibility criteria included not having significant cognitive impairment. Participants were aged 39-64 (M = 54.17, SD = 6.9), 66% female, 81% married, 90% White, and 80% had a college degree.

INTERVENTION

Treatment included an activity tracker, Gray Matters app, access to booster sessions, contact with a student health coach, and study website.

SETTING

Participants were in the general community.

RESULTS

Independent samples t-tests determined that intrinsic motivation (IM) increased significantly for the treatment group (M = 2.09 SD = 4.82), compared to the control group (M = 1.00 SD = 5.52; t (130) = -3.04, p = .003). Comparing subgroups of people with High vs Low IM we found that High IM males increased vigorous physical activity more than Lower IM males (F(1,42)=5.053, p=.030). Comparing persons aged 58-64 years with High vs Lower IM, High IM persons had less improvement in diet quality F(1,48)=4.538; p=0.038).

CONCLUSION

RCT results support that the Gray Matters AD-focused intervention increased IM, and IM was associated with improved physical activity and diet quality for some subgroups.

Efficacy, safety and pharmacokinetics of a new high-purity factor X concentrate in women and girls with hereditary factor X deficiency

Essentials Plasma-derived factor X concentrate (pdFX) is used to treat hereditary factor X deficiency. pdFX pharmacokinetics, safety and efficacy were assessed in factor X-deficient women/girls. Treatment success rate was 98%; only 6 adverse events in 2 subjects were possibly pdFX related. On-demand pdFX 25 IU kg-1 was effective and safe in women/girls with factor X deficiency.

SUMMARY

Background A high-purity, plasma-derived factor X concentrate (pdFX) has been approved for the treatment of hereditary FX deficiency, an autosomal recessive disorder. Objective To perform post hoc assessments of pdFX pharmacokinetics, safety and efficacy in women and girls with hereditary FX deficiency. Patients/Methods Subjects aged ≥ 12 years with moderate/severe FX deficiency (plasma FX activity of < 5 IU dL-1 ) received on-demand or preventive pdFX (25 IU kg-1 ) for ≤ 2 years. Results Of 16 enrolled subjects, 10 women and girls (aged 14-58 years [median, 25.5 years]) received 267 pdFX infusions. Mean monthly infusions per subject were higher among women and girls (2.48) than among men and boys (1.62). In women and girls, 132 assessable bleeding episodes (61 heavy menstrual bleeds, 47 joint bleeds, 15 muscle bleeds, and nine other bleeds) were treated with pdFX, with a 98% treatment success rate versus 100% in men and boys. Mean pdFX incremental recovery was similar in the two groups (2.05 IU dL-1 versus 1.91 IU dL-1 per IU kg-1 ), as was the mean half-life (29.3 h versus 29.5 h). Of 142 adverse events in women and girls, headache was the most common (12 events in six subjects). Six events (two infusion-site erythema, two fatigue, one back pain, one infusion-site pain) in two subjects were considered to be possibly pdFX-related. Following the trial, pdFX was used to successfully maintain hemostasis in two subjects undergoing obstetric delivery. Conclusions pdFX was well tolerated and effective in women and girls with FX deficiency. Although women and girls had different bleeding symptoms and sites than men and boys, their pdFX pharmacokinetic profile was comparable.

The future of dementia risk reduction research: barriers and solutions

BACKGROUND

We examine why dementia prevention and risk reduction are relatively underfunded and suggest potential remediation strategies. The paper is aimed at researchers, funders and policy-makers, both within dementia and also the wider health prevention field.

METHODS

A discussion-led workshop, attended by 58 academics, clinicians, funders and policy-makers.

RESULTS

The key barriers identified were the gaps in understanding the basic science of dementia; the complex interplay between individual risk factors; variations in study methodology; disincentives to collaboration; a lack of research capacity and leadership and the broader stigma of the condition. Recommendations were made to encourage strategic leadership, provide greater support for grant applications, promote collaboration and support randomized control trials for the research field.

CONCLUSION

Having identified the barriers, the key challenge is how to implement the potential solutions. This will require engagement with decision-makers within funding, policy and research to ensure that action takes place.

Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

We identified rare coding variants associated with Alzheimer's disease in a three-stage case-control study of 85,133 subjects. In stage 1, we genotyped 34,174 samples using a whole-exome microarray. In stage 2, we tested associated variants (P < 1 × 10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, we used an additional 14,997 samples to test the most significant stage 2 associations (P < 5 × 10-8) using imputed genotypes. We observed three new genome-wide significant nonsynonymous variants associated with Alzheimer's disease: a protective variant in PLCG2 (rs72824905: p.Pro522Arg, P = 5.38 × 10-10, odds ratio (OR) = 0.68, minor allele frequency (MAF)cases = 0.0059, MAFcontrols = 0.0093), a risk variant in ABI3 (rs616338: p.Ser209Phe, P = 4.56 × 10-10, OR = 1.43, MAFcases = 0.011, MAFcontrols = 0.008), and a new genome-wide significant variant in TREM2 (rs143332484: p.Arg62His, P = 1.55 × 10-14, OR = 1.67, MAFcases = 0.0143, MAFcontrols = 0.0089), a known susceptibility gene for Alzheimer's disease. These protein-altering changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified risk genes in Alzheimer's disease. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to the development of Alzheimer's disease.

l-phenylalanine modulates gut hormone release and glucose tolerance, and suppresses food intake through the calcium-sensing receptor in rodents

OBJECTIVE

High-protein diets (HPDs) are associated with greater satiety and weight loss than diets rich in other macronutrients. The exact mechanisms by which HPDs exert their effects are unclear. However, evidence suggests that the sensing of amino acids produced as a result of protein digestion may have a role in appetite regulation and satiety. We investigated the effects of l-phenylalanine (L-Phe) on food intake and glucose homeostasis in rodents.

METHODS

We investigated the effects of the aromatic amino-acid and calcium-sensing receptor (CaSR) agonist l-phenylalanine (L-Phe) on food intake and the release of the gastrointestinal (GI) hormones peptide YY (PYY), glucagon-like peptide-1 (GLP-1) and ghrelin in rodents, and the role of the CaSR in mediating these effects in vitro and in vivo. We also examined the effect of oral l-Phe administration on glucose tolerance in rats.

RESULTS

Oral administration of l-Phe acutely reduced food intake in rats and mice, and chronically reduced food intake and body weight in diet-induced obese mice. Ileal l-Phe also reduced food intake in rats. l-Phe stimulated GLP-1 and PYY release, and reduced plasma ghrelin, and also stimulated insulin release and improved glucose tolerance in rats. Pharmacological blockade of the CaSR attenuated the anorectic effect of intra-ileal l-Phe in rats, and l-Phe-induced GLP-1 release from STC-1 and primary L cells was attenuated by CaSR blockade.

CONCLUSIONS

l-Phe reduced food intake, stimulated GLP-1 and PYY release, and reduced plasma ghrelin in rodents. Our data provide evidence that the anorectic effects of l-Phe are mediated via the CaSR, and suggest that l-Phe and the CaSR system in the GI tract may have therapeutic utility in the treatment of obesity and diabetes. Further work is required to determine the physiological role of the CaSR in protein sensing in the gut, and the role of this system in humans.

Decortication and osteotomy for the correction of multiplanar deformity in the treatment of malunion in adult diaphyseal femoral deformity: a case series and technique description

AIM

To review patients that have undergone correction of a symptomatic femoral malunion using osteotomy combined with decortication.

METHODS

A retrospective review of all patients who have undergone decortication and multiplanar osteotomy, looking at the pre-operative deformity, correction achieved, time to union and complications.

RESULTS

Seven patients underwent correction under the senior author from 2003 to 2012. Average age was 46 years (range 32-60 years). All had femoral shortening deformity (average 2.7 cm, range 2-4 cm). Each also had at least one other plane of deformity with rotation being the next most commonly encountered in 5 out of the 7 (average 33°, range 0°-45°). Two had tri-planar deformity with the five having bi-planar deformity. Average time to union was 16.3 months (range 7-39 months) with an average of 1.5 operations (range 1-3 operations) to union. One patient has a non-union after five corrective operations.

CONCLUSION

Correction of multiplanar deformity of the femur is challenging. Osteotomy with decortication provides a technique to achieve significant femoral multiplanar deformity correction in a single operation. This publication provides technical description of the operative technique, guidance and results.

Particle damage sources for fused silica optics and their mitigation on high energy laser systems

High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of damage to critical fused silica optics, which grows rapidly upon exposure to additional laser pulses. Much progress has been made in eliminating damage precursors in as-processed fused silica optics (the advanced mitigation process, AMP3), and very high damage resistance has been demonstrated in laboratory studies. However, the full potential of these improvements has not yet been realized in actual laser systems. In this work, we explore the importance of additional damage sources-in particular, particle contamination-for fused silica optics fielded in a high-performance laser environment, the National Ignition Facility (NIF) laser system. We demonstrate that the most dangerous sources of particle contamination in a system-level environment are laser-driven particle sources. In the specific case of the NIF laser, we have identified the two important particle sources which account for nearly all the damage observed on AMP3 optics during full laser operation and present mitigations for these particle sources. Finally, with the elimination of these laser-driven particle sources, we demonstrate essentially damage free operation of AMP3 fused silica for ten large optics (a total of 12,000 cm² of beam area) for shots from 8.6 J/cm² to 9.5 J/cm² of 351 nm light (3 ns Gaussian pulse shapes). Potentially many other pulsed high energy laser systems have similar particle sources, and given the insight provided by this study, their identification and elimination should be possible. The mitigations demonstrated here are currently being employed for all large UV silica optics on the National Ignition Facility.

L-arginine promotes gut hormone release and reduces food intake in rodents

AIMS

To investigate the anorectic effect of L-arginine (L-Arg) in rodents.

METHODS

We investigated the effects of L-Arg on food intake, and the role of the anorectic gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), the G-protein-coupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents.

RESULTS

Oral gavage of L-Arg reduced food intake in rodents, and chronically reduced cumulative food intake in diet-induced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. L-Arg stimulated GLP-1 and PYY release in vitro and in vivo. Pharmacological blockade of GLP-1 and PYY receptors did not influence the anorectic effect of L-Arg. L-Arg-mediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of L-Arg suppressed food intake in rats.

CONCLUSIONS

L-Arg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of L-Arg is unlikely to be mediated by GLP-1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of L-Arg suppressed food intake in rats, suggesting that L-Arg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which L-Arg suppresses food intake and its utility in the treatment of obesity.

Use of diuretics is associated with reduced risk of Alzheimer's disease: the Cache County Study

Although the use of antihypertensive medications has been associated with reduced risk of Alzheimer's disease (AD), it remains unclear which class provides the most benefit. The Cache County Study of Memory Health and Aging is a prospective longitudinal cohort study of dementing illnesses among the elderly population of Cache County, Utah. Using waves I to IV data of the Cache County Study, 3417 participants had a mean of 7.1 years of follow-up. Time-varying use of antihypertensive medications including different class of diuretics, angiotensin converting enzyme inhibitors, β-blockers, and calcium channel blockers was used to predict the incidence of AD using Cox proportional hazards analyses. During follow-up, 325 AD cases were ascertained with a total of 23,590 person-years. Use of any antihypertensive medication was associated with lower incidence of AD (adjusted hazard ratio [aHR], 0.77; 95% confidence interval [CI], 0.61-0.97). Among different classes of antihypertensive medications, thiazide (aHR, 0.7; 95% CI, 0.53-0.93), and potassium-sparing diuretics (aHR, 0.69; 95% CI, 0.48-0.99) were associated with the greatest reduction of AD risk. Thiazide and potassium-sparing diuretics were associated with decreased risk of AD. The inverse association of potassium-sparing diuretics confirms an earlier finding in this cohort, now with longer follow-up, and merits further investigation.

Vascular risk factors and neuropsychiatric symptoms in Alzheimer's disease: the Cache County Study

OBJECTIVE

Knowledge of potentially modifiable risk factors for neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) is important. This study longitudinally explores modifiable vascular risk factors for NPS in AD.

METHODS

Participants enrolled in the Cache County Study on Memory in Aging with no dementia at baseline were subsequently assessed over three additional waves, and those with incident (new onset) dementia were invited to join the Dementia Progression Study for longitudinal follow-up. A total of 327 participants with incident AD were identified and assessed for the following vascular factors: atrial fibrillation, hypertension, diabetes mellitus, angina, coronary artery bypass surgery, myocardial infarction, cerebrovascular accident, and use of antihypertensive or diabetes medicines. A vascular index (VI) was also calculated. NPS were assessed over time using the Neuropsychiatric Inventory (NPI). Affective and Psychotic symptom clusters were assessed separately. The association between vascular factors and change in NPI total score was analyzed using linear mixed model and in symptom clusters using a random effects model.

RESULTS

No individual vascular risk factors or the VI significantly predicted change in any individual NPS. The use of antihypertensive medications more than four times per week was associated with higher total NPI and Affective cluster scores.

CONCLUSIONS

Use of antihypertensive medication was associated with higher total NPI and Affective cluster scores. The results of this study do not otherwise support vascular risk factors as modifiers of longitudinal change in NPS in AD.

Delirium assessment in postoperative patients: Validation of the Portuguese version of the Nursing Delirium Screening Scale in critical care

BACKGROUND AND OBJECTIVES

The aim of this study was to validate the Portuguese version of the Nursing Delirium Screening Scale (Nu-DESC) for use in critical care settings.

METHODS

We simultaneously and independently evaluated all postoperative patients admitted to a surgical Intensive Care Unit (SICU) over a 1-month period for delirium, using the Portuguese versions of both the Nu-DESC and the Intensive Care Delirium Screening Checklist (ICDSC) within 24 hours of admission by both the research staff physician and one bedside nurse. We determined the diagnostic accuracy of the Nu-DESC using sensitivity, specificity and ROC curve analyses. We assessed reliability between nurses and the research staff physician for Nu-DESC by intraclass correlation coefficient (ICC). We assessed agreement and reliability between Nu-DESC and ICDSC by overall and specific proportions of agreement and by kappa statistics.

RESULTS

Based on the ICDSC, we diagnosed delirium in 12 of the 78 patients. Reliability between nurses and the staff physician for total Nu-DESC score was high. Agreement between nurses and staff physician in the delirium diagnosis was perfect. The proportion of overall agreement between Nu-DESC and ICDSC in the delirium diagnosis was 0.88 and the kappa ranged from 0.79 to 0.93. Nu-DESC Sensitivity was 100 and specificity was 86%.

CONCLUSIONS

The Portuguese version of the Nu-DESC appears to be an accurate and reliable assessment and monitoring instrument for delirium in critical care settings.

Residual neuromuscular block as a risk factor for critical respiratory events in the post anesthesia care unit

OBJECTIVE

Residual neuromuscular block is an important postoperative complication associated to the use of neuromuscular blocking drugs. The purpose of this study was to access the incidence of residual neuromuscular block in a post-anesthesia care unit and to evaluate its association with critical respiratory events.

MATERIAL AND METHODS

Prospective cohort study was conducted in a Post Anesthetic Care Unit (PACU) for a period of 3 weeks. Two hundred two adult patients who submitted to scheduled non-cardiac and non-intracranial surgery were eligible to the study. The primary outcome variable was residual neuromuscular block after arrival to PACU that was defined as train-of-four ratio <0.9 and objectively quantified using acceleromyography. Demographic data, perioperative variables, lengths of hospital and recovery room stay and critical respiratory events were recorded. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale 10 min after admission to the recovery room.

RESULTS

Residual neuromuscular block incidence in the post-anesthesia care unit was 29.7% (95% confidence interval: 23.4, 36.1). Patients with residual neuromuscular block had more frequently overall critical respiratory events (51% versus 16%, P<0.001), airway obstruction (10% versus 2%, P=0.029), mild-moderate hypoxemia (23% versus 4%, P<0.001), severe hypoxemia (7% versus 1%, P=0.033), respiratory failure (8% versus 1%, P=0.031), inability to breathe deeply (38% versus 12%, P<0.001) and muscular weakness (16% versus 1%, P<0.001). Residual neuromuscular block was more common after high-risk surgery (53% versus 33%, P=0.011) and was more often associated with post-operative hypoactive emergence as defined by the Richmond Agitation and Sedation Scale (21% versus 6%, P=0.001).

CONCLUSIONS

This study suggests that residual neuromuscular block is common in the PACU and is associated with more frequent critical respiratory events.

Meta-analysis of the safety, tolerability, and efficacy of lopinavir/ritonavir-containing antiretroviral therapy in HIV-1-infected women

PURPOSE

Women comprise ≯50% of HIV-infected patients, yet safety, tolerability, and efficacy data in women taking antiretrovirals (ARVs) are limited. Lopinavir/ ritonavir (LPV/r)-anchored regimens are globally the most widely prescribed HIV-1 protease inhibitor regimens. The objective was to investigate the safety and efficacy of LPV/r-based therapy in women.

METHODS

A database query yielded all available data in HIV-1-infected subjects receiving LPV/r-based triple-ARV regimens from randomized clinical trials lasting ≥48 weeks from Abbott or Abbott-supported AIDS Clinical Trials Group studies. Efficacy (HIV-1 RNA levels, CD4+ T-cell counts) and safety and tolerability (treatment discontinuation, treatment-related adverse events [AE], and clinical laboratory abnormalities) at 48 weeks were assessed for total women, women by age (≥50, <50 years) and body mass index (BMI; <25, ≥25 to <30, ≥30 kg/m2), and sex.

RESULTS

Nine hundred ninety-two women initiated LPV/r-based therapy (of whom 79.2% were ARV-naïve), with 83.6% completing 48 weeks of treatment. There were 75.5% of women who achieved a threshold of HIV RNA <400 copies/mL by intent-to-treat, non-completer equals failure (ITT, NC = F) analysis, with a mean ± SE CD4+ T-cell count increase of 191.6 ± 4.92 cells/mm3 from baseline. Women aged ≥50 versus <50 years had higher incidence of moderate-to-severe treatment-related AEs and certain laboratory abnormalities, better virologic response (HIV RNA <400 copies/mL by ITT, NC = F), similar immunologic responses, and similar overall incidence of treatment discontinuations. Higher incidences of certain moderate-to-severe treatment-related AEs and laboratory abnormalities occurred in women with BMI ≥30 kg/m2; however, no effect of BMI on efficacy or discontinuation was observed.

CONCLUSIONS

LPV/r-based regimens were efficacious and well-tolerated in women without marked differences based on age and BMI categories evaluated.

Hormone therapy and Alzheimer disease dementia: new findings from the Cache County Study

OBJECTIVES

Observational studies suggest reduced risk of Alzheimer disease (AD) in users of hormone therapy (HT), but trials show higher risk. We examined whether the association of HT with AD varies with timing or type of HT use.

METHODS

Between 1995 and 2006, the population-based Cache County Study followed 1,768 women who had provided a detailed history on age at menopause and use of HT. During this interval, 176 women developed incident AD. Cox proportional hazard models evaluated the association of HT use with AD, overall and in relation to timing, duration of use, and type (opposed vs unopposed) of HT.

RESULTS

Women who used any type of HT within 5 years of menopause had 30% less risk of AD (95% confidence interval 0.49-0.99), especially if use was for 10 or more years. By contrast, AD risk was not reduced among those who had initiated HT 5 or more years after menopause. Instead, rates were increased among those who began "opposed" estrogen-progestin compounds within the 3 years preceding the Cache County Study baseline (adjusted hazard ratio 1.93; 95% confidence interval 0.94-3.96). This last hazard ratio was similar to the ratio of 2.05 reported in randomized trial participants assigned to opposed HT.

CONCLUSIONS

Association of HT use and risk of AD may depend on timing of use. Although possibly beneficial if taken during a critical window near menopause, HT (especially opposed compounds) initiated in later life may be associated with increased risk. The relation of AD risk to timing and type of HT deserves further study.

Caregivers' relationship closeness with the person with dementia predicts both positive and negative outcomes for caregivers' physical health and psychological well-being

Closer relationships between caregivers and care recipients with dementia are associated with positive outcomes for care recipients, but it is unclear if closeness is a risk or protective factor for the health and psychological wellbeing of caregivers. We examined 234 care dyads from the population-based Cache County Dementia Progression Study. Caregivers included spouses (49%) and adult offspring (51%). Care recipients mostly had dementia of the Alzheimer’s type (62%). Linear mixed models tested associations between relationship closeness at baseline or changes in closeness prior to versus after dementia onset, with baseline levels and changes over time in caregiver affect (Affect Balance Scale, ABS), depression (Beck Depression Inventory, BDI), and mental and physical health (components of the Short-Form Health Survey, SF-12). After controlling for demographic characteristics of the caregiver, number of caregiver health conditions, and characteristics of the care recipient (type of dementia, functional ability, and behavioral disturbances), we found that higher baseline closeness predicted higher baseline SF-12 mental health scores (better mental health) and lower depression. Higher baseline closeness also predicted greater worsening over time in ABS and SF-12 mental health. In addition, caregivers who reported a loss of closeness in their relationship with the care recipient from pre- to post-dementia displayed improved scores on ABS and SF-12 mental health, but worse SF-12 physical health over the course of the study. These results suggest that closeness and loss of closeness in the care dyad may be associated with both positive and adverse outcomes for caregivers, both cross-sectionally and over time.

Prospective one-year bone loss in treatment-naïve HIV+ men and women on single or multiple drug HIV therapies

Antiretroviral therapy has decreased the rate of HIV-related mortality and extended the life span of HIV patients. Current guidelines recommend the use of a 3-drug regimen, such as two nucleoside reverse transcriptase inhibitors and a protease inhibitor, boosted by ritonavir. Osteoporosis can be associated with the HIV disease itself or with antiretroviral therapy. Many trials have been conducted employing a single drug regimen to simplify antiretroviral therapy but few studies assessed the effect of the single drug regimen on bone mineral density (BMD). The objectives of the study were to assess and compare the relative (%) changes in lumbar spine and hip BMD over 48 weeks in HIV patients treated with mono or triple antiretroviral regimens The study was conducted using data from a randomized trial (MONARK) conducted in 136 antiretroviral-naïve HIV patients (89 men and 47 women) comparing the antiviral efficacy of a single-drug protease inhibitor regimen of lopinavir/ritonavir (LPV/r) versus LPV/r in combination with zidovudine (ZDV) and lamivudine (3TC). Lumbar spine and total hip BMD were assessed in 100 patients by dual-energy X-ray absorptiometry at baseline and 48 weeks. 48 week-BMD data were available for 43 patients (mean age 37years) with a mean baseline lumbar spine Z-score of -0.1 in the LPV/r monotherapy group and for 25 patients (mean age 35.8years) with a mean baseline lumbar spine Z-score of -0.2 in the LPV/r+ZDV+3TC group. After 48weeks, lumbar spine BMD significantly decreased by 4.4% (-5.1% to -2.1%, P≤0.001) in the LPV/r group and by 4.0% (-5.0% to -1.7%, P≤0.0001) in the LPV/r+ZDV+3TC group. There was no significant difference in BMD changes between the two groups. These results suggest that bone loss is observed 48 weeks after the initiation of antiretroviral therapy, whether the patients receive a single- or triple-drug antiretroviral regimen.