Depletion of systemic macrophages by liposome-encapsulated clodronate attenuates striatal macrophage invasion and neurodegeneration following local endotoxin infusion in gerbils

CNS-localized inflammation with microglial activation and macrophage infiltration contributes to the pathogenesis of a broad spectrum of neurologic diseases. A direct injection of lipopolysaccharide (LPS) into the striatum of gerbils induced lectin-positive macrophage parenchymal invasion, minimal local microglial staining but extensive neurodegeneration (cresyl violet and silver staining) when evaluated 4 days later. In mice, LPS activated microglia (increased lectin staining of morphologically identified cells) with substantially less macrophage invasion but no neurodegeneration was seen at 4 days post LPS infusion. To evaluate the role of infiltrating macrophages in the neurodegenerative response in gerbils, peripheral macrophages were depleted by an intravenous injection of liposome-encapsulated clodronate. This preparation depleted spleen and liver macrophages (>95%), decreased blood monocytes by 55% and attenuated striatal macrophage infiltration (32 to 73% in five representative sections). Notably, the liposome-encapsulated clodronate reduced the severity of LPS-induced neurodegeneration, as visualized by cresyl violet staining and quantified in 20 serially stained silver sections (total volume, 1.32+/-0.41 mm(3) in liposome-encapsulated clodronate-treated versus 3.04+/-0.72 mm(3) in saline-treated controls). These results indicate that a local LPS infusion in gerbil brain may be a useful model in which to investigate the role of invading macrophages and other inflammatory responses in neurodegeneration in inflammatory neurological disease.

Characteristics and outcomes of AED use in pediatric cardiac arrest in public settings: The influence of neighborhood characteristics

BACKGROUND

Automated external defibrillators (AEDs) are critical in the chain of survival following out-of-hospital cardiac arrest (OHCA), yet few studies have reported on AED use and outcomes among pediatric OHCA. This study describes the association between bystander AED use, neighborhood characteristics and survival outcomes following public pediatric OHCA.

METHODS

Non-traumatic OHCAs among children less than18 years of age in a public setting between from January 1, 2013 through December 31, 2017 were identified in the CARES database. A neighborhood characteristic index was created from the addition of dichotomous values of 4 American Community Survey neighborhood characteristics at the Census tract level: median household income, percent high school graduates, percent unemployment, and percent African American. Multivariable logistic regression models assessed the association of OHCA characteristics, the neighborhood characteristic index and outcomes.

RESULTS

Of 971 pediatric OHCA, AEDs were used by bystanders in 10.3% of OHCAs. AEDs were used on 2.3% of children ≤1 year (infants), 8.3% of 2-5 year-olds, 12.4% of 6-11 year-olds, and 18.2% of 12-18 year-olds (p < 0.001). AED use was more common in neighborhoods with a median household income of >$50,000 per year (12.3%; p = 0.016), <10% unemployment (12.1%; p = 0.002), and >80% high school education (11.8%; p = 0.002). Greater survival to hospital discharge and neurologically favorable survival were among arrests with bystander AED use, varying by neighborhood characteristics.

CONCLUSIONS

Bystander AED use is uncommon in pediatric OHCA, particularly in high-risk neighborhoods, but improves survival. Further study is needed to understand disparities in AED use and outcomes.

Evaluating the interactions between red stingray (Dasyatis akajei) melanocortin receptors and elephant shark (Callorhinchus milii) MRAP1 and MRAP2 following stimulation with either stingray ACTH(1-24) or stingray Des-Acetyl-αMSH: A pharmacological study in Chinese Hamster Ovary cells

Previous studies on bony vertebrate MC2R orthologs (i.e., ray finned fishes, amphibians, reptiles, birds, and mammals) have shown that these MC2R orthologs have an obligatory requirement for interaction with bony vertebrate MRAP1 orthologs to a) allow for the trafficking of the MC2R ortholog to the plasma membrane; and b) to allow activation by ACTH, but not by any MSH-sized ligand. In addition, previous studies have found that co-expression of teleost and mammalian MC4R orthologs with corresponding MRAP2 has positive effects on sensitivity to stimulation by αMSH or ACTH. MRAP1 and MRAP2 paralogs have been detected in the genome of a cartilaginous fish (elephant shark), yet two cartilaginous fish MC2R orthologs (elephant shark and red stingray) do not apparently require MRAP1 for trafficking to the plasma membrane when expressed in Chinese Hamster Ovary (CHO) cells, and both orthologs can be activated by either ACTH or MSH-sized ligands. This study was done to determine whether sensitivity to stimulation by ACTH(1-24) or Des-Acetyl-αMSH is affected when stingray (sr) MC1R, MC2R, MC3R, MC4R or MC5R were co-expressed in CHO cells with either elephant shark (es) MRAP1 or esMRAP2. The results indicated that co-expression with heterologous MRAP1 increased the sensitivity of all five stingray melanocortin receptors for srACTH(1-24), but had not statistically significant effect on stimulation by srDes-Acetyl-αMSH for any of the stingray melanocortin receptors. Conversely, co-expression with esMRAP2 only enhanced sensitivity for srDes-Acetyl-αMSH for srMC4R, but had no effect on the other stingray orthologs, and there was no increase in sensitivity for srACTH(1-24) for any of the stingray melanocortin receptors. It appears then that some stingray melanocortin receptors have retained the ability to interact with a cartilaginous MRAP1 paralog. These results are discussed with reference to radiation of MRAP-related accessory proteins in cartilaginous fishes.

Hemispatial factors in mirror writing

The effect of the hemispace in which writing was performed was assessed in two left hemisphere stroke patients who demonstrated left-handed mirror writing. Both patients produced significantly more mirrored words when writing in right, as compared to left (body) hemispace. We suggest that writing in the right hemispace activates the left hemisphere. Further, we propose that mirror writing in the right hemispace is attributable to activation of the damaged left hemisphere spatial system, which fails to assist in the translation of right hand motor programs into those appropriate to the left hand. Writing in left hemispace, in contrast, activates the intact right hemisphere based spatial system which guides the execution or monitoring of motor productions in left hemispace. The result is writing which remains directionally correct when the left hand is used in left hemispace.

Anaesthesia for isolated lung transplantation

The anaesthetic management of a patient undergoing successful, left-sided orthotopic single lung transplantation is presented. Problems, specific to the operation, are featured and discussed.

Azathioprine Monotherapy Is Equivalent to Dual Therapy in Maintaining Remission in Autoimmune Hepatitis

BACKGROUND

Standard of care treatment for AIH includes prednisone monotherapy or dual therapy prednisone-azathioprine. However, many hepatologists alternatively use azathioprine monotherapy to avoid side effects of long-term corticosteroids.

AIMS

To determine whether azathioprine monotherapy is comparable to dual prednisone-azathioprine for maintenance of remission in AIH.

METHODS

A retrospective chart review of 260 individuals with AIH from a single institution was performed; 45 individuals were included. Exclusion criteria included concomitant PBC or PSC, use of alternative treatment regimen, and/or failure to reach remission. Treatment regimen received was guided by clinician standard of practice, not patients' clinical factors. Initial remission was defined as normalization of serum ALT for at least two consecutive blood draws. Data were analyzed for 5 years post-remission, recording outcome and dose of prednisone and/or azathioprine.

RESULTS

83% of individuals were female, and average age was 65 years. Median dose of prednisone and azathioprine for the dual-therapy group was 5 mg and 100 mg, respectively, while median azathioprine dose for the monotherapy group was 75 mg. Considering overall outcome, 93% of all patients maintained remission. 80% of the dual-therapy group, and 95% of the azathioprine monotherapy group maintained remission. Using Chi-square analysis to compare the maintenance of remission between dual therapy and azathioprine monotherapy, a p value of 0.28 was calculated.

CONCLUSIONS

AASLD guidelines recommend dual prednisone-azathioprine as standard of care for maintenance of remission in AIH. Our results suggest that azathioprine monotherapy is equivalent to prednisone-azathioprine. Azathioprine monotherapy offers a significant advantage in mitigating risks of long-term corticosteroid therapy.

Fibrosis-4 Index Score Predicts Concomitant Coronary Artery Diseases Across the Spectrum of Fatty Liver Disease

BACKGROUND

25% of US adults have nonalcoholic fatty liver disease (NAFLD). The independent association between hepatic fibrosis and cardiovascular disease remains controversial. Metabolic dysfunction-associated fatty liver disease (MAFLD) precisely characterizes hepatic steatosis.

AIM

We aimed to determine if degree of hepatic fibrosis, with differing metabolic risk factors, is associated with presence of coronary artery disease (CAD).

METHODS

Retrospective review of patients with hepatic steatosis at a single center from January 2016-October 2020 was performed. MAFLD diagnosis was based on presence of fatty liver disease and metabolic factors. Descriptive statistics and stepwise multivariable logistic regression were performed.

RESULTS

5288 patients with hepatic steatosis were included. 2821 patients with steatosis and metabolic risks were classified as NAFLD-MAFLD. 1245 patients with steatosis without metabolic risks were classified as non-MAFLD NAFLD. 812 patients with metabolic risks and other liver disease and were classified as non-NAFLD MAFLD. On Multivariate analysis, Fib-4 ≥ 2.67 was an independent risk factor for CAD in the overall fatty liver disease and NAFLD-MAFLD groups. Fib-4 as a continuous variable showed linear association with CAD risk in the overall fatty liver disease, Non-MAFLD NAFLD and NAFLD-MAFLD groups, at Fib-4 values below 2.67.

CONCLUSION

Fib-4 ≥ 2.67 is independently predicts concomitant CAD in patients with hepatic steatosis. Fib-4, at levels below 2.67, is significantly associated with concomitant CAD in the all fatty liver disease, Non-MAFLD NAFLD, and NAFLD-MAFLD groups. Emphasizing clinical phenotypes and Fib-4 levels may help target those with an increased risk for CAD.

Low and high frequency isometric handgrip exercise training similarly reduce resting blood pressure in young normotensive adults: A randomised controlled trial

We investigated the effects of low and high frequency isometric handgrip exercise training (IHGT) on resting blood pressure, and the affective/perceptual responses during training. Sixty young normotensive adults were randomised to either a no-intervention control group (CON: n = 20; 12 female) or a group performing either two (LOW: n = 20; 18 female) or four (HIGH: n = 20; 13 female) sessions/week of IHGT for 4 weeks. IHGT involved 4 × 2-min holds at 30% maximal voluntary contraction using the dominant hand. Resting blood pressure was measured before and after training. Affective valence was measured during the first session of each training week. Systolic blood pressure was reduced following both LOW (adjusted mean change [95% CI]: -4.5 [-6.8, -2.2] mmHg) and HIGH (-5.3 [-7.6, -3.0] mmHg) frequency IHGT groups compared to CON (+0.5 [-1.8, 2.8] mmHg; p < 0.01), with no difference between LOW and HIGH. There were no changes in diastolic blood pressure. During the first session, affective valence decreased by 2.5 ± 2.6 units and became negative (lowest affect: -0.75 ± 1.84 units). However, affective responses improved as training progressed. Low and high frequency IHGT similarly reduce resting blood pressure in young normotensive adults. Negative affective responses in the early phase of training improve as the intervention progresses.

Theory and design of photon correlation and light-scattering experiments

The inversion of photon correlation functions, angular light-scattering intensities, and spectral turbidity measurements to recover particle-size distributions and the inversion of photon-counting distributions to determine underlying intensity fluctuation distributions are all ill-conditioned problems whose solutions depend sensitively on noise in the data. The special techniques and precautions required for obtaining reliable results and the implications for experimental design are discussed. An example is presented that shows the weakness of the positivity constraint on the solution of ill-conditioned problems such as these.

Cholestatic liver diseases: modern therapeutics

INTRODUCTION

Cholestatic liver disease encompasses a broad group of disorders related to impaired normal bile formation, secretion, or excretion. These diseases present with symptoms of fatigue, jaundice, pruritus, and biochemical changes.

AREAS COVERED

We focus on updates in the management of autoimmune cholestatic liver disease. The mainstay therapy in PBC is UDCA (ursodeoxycholic acid), but OCA (obeticholic acid) can be considered if suboptimal response or intolerance. Fibrates have shown some promising effects in PBC patients who have not responded to or are intolerant of UDCA and/or OCA; however, they are not FDA approved. Peroxisome Proliferator-Activated Receptor Agonists (PPARs) have emerged as a promising new class of oral agents in PBC. Also, Ileal Bile Acid Transporter (IBAT) inhibitors are being investigated for the treatment of pruritus related to PBC. There are no available treatments for PSC; however, there have been previous investigations into many agents. There are ongoing clinical trials investigating the role of various antibiotics, PPARs, and immunomodulators for the treatment of PSC.

EXPERT OPINION

Ongoing investigations into the treatment of both PBC and PSC are essential. We anticipate that alternative management strategies for PBC and PSC will continue to arise in the next 5-10 years.

Juvenile idiopathic arthritis and exposure to fine particulate air pollution

OBJECTIVES

Inhalation of fine particulate matter, including particles with an aerodynamic diameter less than or equal to a 2.5-microm cut point (PM2.5), has been associated with systemic inflammation and the clinical presentation of various cardiopulmonary heath events. The urban area along Utah's Wasatch Mountains has high PM2.5 concentrations during periods of stagnant air conditions. Short-term inhalation exposures may trigger inflammatory events presenting as symptom onset in new patients with juvenile idiopathic arthritis (JIA). This study evaluated potential associations between JIA symptom onset and temporal changes in regional air pollution measured by stagnant air conditions and PM2.5 concentrations.

METHODS

A case-crossover design was used to analyze associations of regional ambient PM2.5 concentrations with onset date of 338 JIA cases living on Utah's Wasatch Front. Patients were drawn from the Intermountain States Database of Childhood Rheumatic Diseases (1993-2006). Time trends, seasonality, month, and weekday were controlled for by matching. Selected exposure windows of PM2.5 and stagnant air days were used in the model to determine the effect of short term cumulative exposure on JIA symptom onset.

RESULTS

Increased concentrations of PM2.5 and stagnant air conditions in the preceding 14 days were associated with significantly elevated risk of JIA onset in preschool aged children (RR=1.60, 95% CI 1.00-2.54) but not older children. Elevated risk was larger in males and in systemic onset JIA.

CONCLUSION

Exposure to stagnant polluted air may be an environmental risk factor for JIA in young children, potentially triggered by pollution-induced pulmonary mediated inflammation.