Impact of a sustained, collaborative antimicrobial stewardship programme in spinal cord injury patients.

Background: In patients with spinal cord injuries (SCIs), infections continue to be a leading cause of morbidity, mortality and hospital admission. Objectives: This study evaluated the long-term impact of a weekly, multidisciplinary Spinal/Antimicrobial Stewardship (AMS) meeting for acute-care SCI inpatients, on antimicrobial prescribing over 3 years. Methods: A retrospective, longitudinal, pre-post comparison of antimicrobial prescribing was conducted at our tertiary hospital in Melbourne. Antimicrobial prescribing was audited in 6 month blocks pre- (25 April 2017 to 24 October 2017), immediately post- (27 March 2018 to 25 September 2018) and 3 years post-implementation (2 March 2021 to 31 August 2021). Antimicrobial orders for patients admitted under the spinal unit at the meeting time were included. Results: The number of SCI patients prescribed an antimicrobial at the time of the weekly meeting decreased by 40% at 3 years post-implementation [incidence rate ratio (IRR) 0.63; 95% CI 0.51-0.79; P ≤ 0.001]. The overall number of antimicrobial orders decreased by over 22% at 3 years post-implementation (IRR 0.78; 95% CI 0.61-1.00; P = 0.052). A shorter antimicrobial order duration in the 3 year post-implementation period was observed (-28%; 95% CI -39% to -15%; P ≤ 0.001). This was most noticeable in IV orders at 3 years (-36%; 95% CI -51% to -16%; P = 0.001), and was also observed for oral orders at 3 years (-25%; 95% CI -38% to -10%; P = 0.003). Antimicrobial course duration (days) decreased for multiple indications: skin and soft tissue infections (-43%; 95% CI -67% to -1%; P = 0.045), pulmonary infections (-45%; 95% CI -67% to -9%; P = 0.022) and urinary infections (-31%; 95% CI -47% to -9%; P = 0.009). Ninety-day mortality rates were not impacted. Conclusions: This study showed that consistent, collaborative meetings between the Spinal and AMS teams can reduce antimicrobial exposure for acute-care SCI patients without adversely impacting 90 day mortality.

Experimental test of the geometric model of image formation in bright-field microscopy.

In the geometric optics approximation, an image formed by an objective lens replicates the distribution of intensity at the front focal plane of the objective. Although this fact represents a fundamental optical principle, its application to analysis of bright-field microscopic images was developed only recently and has not been tested experimentally. In this paper, we applied simple ray tracing to compute an image of a glass cylinder at various positions of the objective and to compare it to the experiment. We obtained a close match between theory and observation, except for a slight underestimation of the intensity in the middle part of the cylinder. The likely reason for this minor difference was constructive interference due to lens-like properties of a cylinder, which could not be accounted for by geometric approximation. We expect that such artefacts would be negligible in imaging of live cells, and the geometric approach would successfully complement the existing quantitative phase methods.

It has become customary to analyse microscopic images in terms of diffraction theory. However, when one is not interested in resolving fine details of an image, a much simpler and more intuitive geometric analysis based on ray tracing can be adequate. We applied geometric approach to analysis of bright-field images of a small glass cylinder at different positions of the objective. Such an object would be very difficult to analyse using diffraction theory because of its high refractive index and steep boundaries. However, ray tracing produced a good match between theory and experiment. It can become a promising approach in bright-field applications, such as quantitative phase imaging.

Erythropoietin Upregulates Brain Hemoglobin Expression and Supports Neuronal Mitochondrial Activity.

Multiple sclerosis (MS) is a neuro-inflammatory and demyelinating disease. Downregulation of neuronal mitochondrial gene expression and activity have been reported in several studies of MS. We have previously shown that hemoglobin-ß (Hbb) signals to the nucleus of neurons and upregulates H3K4me3, a histone mark involved in regulating cellular metabolism and differentiation. The present study was undertaken to evaluate the effect of erythropoietin (EPO) on the upregulation of hemoglobin and mitochondrial-associated neuroprotection. We found that administering EPO (5000 IU/kg intraperitoneally) to mice upregulated brain Hbb expression, levels of H3K4me3, expression of mitochondrial complex III, complex V, and mitochondrial respiration. We also found that the neuronal mitochondrial metabolite N-acetylaspartate (NAA), a marker of neuronal mitochondrial activity, was increased with EPO treatment. Further, we measured the effects of EPO on preventing mitochondrial deficits in the cuprizone toxic demyelinating mouse model of MS. We found that EPO prevented cuprizone-mediated decreases in Hbb, complex III, and NAA. Our data suggest that EPO mediated regulation of Hbb supports neuronal energetics and may provide neuroprotection in MS and other neurodegenerative diseases where a dysfunction of mitochondria contributes to disease.

Liquid crystal elastomer foams with elastic properties specifically engineered as biodegradable brain tissue scaffolds.

Tissue regeneration requires 3-dimensional (3D) smart materials as scaffolds to promote transport of nutrients. To mimic mechanical properties of extracellular matrices, biocompatible polymers have been widely studied and a diverse range of 3D scaffolds have been produced. We propose the use of responsive polymeric materials to create dynamic substrates for cell culture, which goes beyond designing only a physical static 3D scaffold. Here, we demonstrated that lactone- and lactide-based star block-copolymers (SBCs), where a liquid crystal (LC) moiety has been attached as a side-group, can be crosslinked to obtain Liquid Crystal Elastomers (LCEs) with a porous architecture using a salt-leaching method to promote cell infiltration. The obtained SmA LCE-based fully interconnected-porous foams exhibit a Young modulus of 0.23 ± 0.07 MPa and a biodegradability rate of around 20% after 15 weeks both of which are optimized to mimic native environments. We present cell culture results showing growth and proliferation of neurons on the scaffold after four weeks. This research provides a new platform to analyse LCE scaffold-cell interactions where the presence of liquid crystal moieties promotes cell alignment paving the way for a stimulated brain-like tissue.

Dysregulation of methionine metabolism in multiple sclerosis.

We report a significant reduction in plasma methionine concentrations in relapse remitting multiple sclerosis (MS) patients compared to controls. In vivo studies demonstrate that changes in peripheral methionine levels in mice can regulate histone H3 methylation and expression of DNA methyltransferase 3A (DNMT3A) centrally, in the cerebral cortex. Therefore, we propose that decreases in circulating methionine represent one of the earliest manifestations of dysregulated methionine metabolism in MS with potential impacts on both histone H3 and DNA methylation in the central nervous system.

Exploratory analysis of factors associated with venous thromboembolism in Victorian acute traumatic spinal cord-injured patients 2010-2013.

STUDY DESIGN: A retrospective medical records audit. OBJECTIVES: To investigate the presence of venous thromboembolism (VTE) events following acute traumatic spinal cord injury (SCI) and the association between VTE events and a number of postulated risk factors. SETTING: The state-wide SCI service in Victoria Australia (Victorian Spinal Cord Service) located at Austin Hospital Melbourne Australia. METHODS: A retrospective electronic medical records file audit was performed of all patients admitted to VSCS between 2010 and 2013 with an acute traumatic SCI. The outcome measure was the presence of VTE (deep venous thrombosis (DVT), pulmonary embolism (PE) or both). Data were also collected on a variety of established and postulated risk factors for VTE post SCI. RESULTS: VTE events occurred in 21.2% of acute SCI patients during the hospitalisation of the patient. Statistically significant associations were found between the presence of VTE events and increased weight, male sex, completeness of motor paralysis, length of stay (LOS), associated pelvic or lower limb fracture and delayed admission to the state-wide spinal cord service. CONCLUSION: Further studies are warranted to investigate whether in other SCI centres the risk of VTE in acute SCI patients is similarly associated with the risk factors identified in our study. A study exploring whether giving acute SCI patients of heavier weight a larger dose of chemical thromboprophylaxis is safe and efficacious is also warranted.

The neuronal metabolite NAA regulates histone H3 methylation in oligodendrocytes and myelin lipid composition.

The neuronal mitochondrial metabolite N-acetylaspartate (NAA) is decreased in the multiple sclerosis (MS) brain. NAA is synthesized in neurons by the enzyme N-acetyltransferase-8-like (NAT8L) and broken down in oligodendrocytes by aspartoacylase (ASPA) into acetate and aspartate. We have hypothesized that NAA links the metabolism of axons with oligodendrocytes to support myelination. To test this hypothesis, we performed lipidomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance thin-layer chromatography (HPTLC) to identify changes in myelin lipid composition in postmortem MS brains and in NAT8L knockout (NAT8L-/-) mice which do not synthesize NAA. We found reduced levels of sphingomyelin in MS normal appearing white matter that mirrored decreased levels of NAA. We also discovered decreases in the amounts of sphingomyelin and sulfatide lipids in the brains of NAT8L-/- mice compared to controls. Metabolomic analysis of primary cultures of oligodendrocytes treated with NAA revealed increased levels of α-ketoglutarate, which has been reported to regulate histone demethylase activity. Consistent with this, NAA treatment resulted in alterations in the levels of histone H3 methylation, including H3K4me3, H3K9me2, and H3K9me3. The H3K4me3 histone mark regulates cellular energetics, metabolism, and growth, while H3K9me3 has been linked to alterations in transcriptional repression in developing oligodendrocytes. We also noted the NAA treatment was associated with increases in the expression of genes involved in sulfatide and sphingomyelin synthesis in cultured oligodendrocytes. This is the first report demonstrating that neuronal-derived NAA can signal to the oligodendrocyte nucleus. These data suggest that neuronal-derived NAA signals through epigenetic mechanisms in oligodendrocytes to support or maintain myelination.

A Simplified Protocol for the Treatment of Alcohol Withdrawal.

OBJECTIVES: The aim of the study was to evaluate a novel simplified tool for symptom-triggered treatment of alcohol withdrawal. METHODS: This retrospective cohort study involved inpatients in a county hospital with an International Classification of Diseases, Ninth Revision, Clinical Modification discharge diagnosis of alcohol withdrawal syndrome (AWS) or delirium tremens between January 1, 2007 and December 31, 2008. The study used the Highland Alcohol Withdrawal Protocol (HAWP)-a simplified derivative of the Revised Clinical Institute Withdrawal Assessment for Alcohol. Multivariable regression analysis was performed to compare severity of withdrawal to hospital length of stay, total dose of sedative given, and risk of complications. RESULTS: The study identified 442 patients with a primary diagnosis of AWS or delirium tremens, and those with another primary medical diagnosis complicated by alcohol withdrawal. After adjusting for demographic variables, each one-point increase in the initial and maximum HAWP scores correlated with an increase in the hospital length of stay of 0.3 days [95% confidence interval (95% CI), 0.17 to 0.43 days] and 0.45 days (95% CI, 0.32-0.57 days), and a 15.8 mg (95% CI, 6.6-25.1 mg) and 19.8 mg (95% CI, 11.1-28.5 mg) increase in the total dose of lorazepam given, respectively. The complication rate of seizures, intubations, pneumonia, and death was 13.1%, 12.9%, 6.1% and 0.9%, respectively; a composite endpoint of these outcomes also correlated with initial and maximum HAWP scores (odds ratio 1.09, 95% CI, 1.03%-1.14%). CONCLUSIONS: The HAWP correlates with medication received and complications, and as such appears to give an indication of AWS severity. It is feasible and shorter than prior scales, and merits further study to confirm its effectiveness as part of symptom-triggered protocols to manage alcohol withdrawal in the hospital.

Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex.

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids.

Prostate MRI: who, when, and how? Report from a UK consensus meeting.

The current pathway for men suspected of having prostate cancer [transrectal biopsy, followed in some cases by magnetic resonance imaging (MRI) for staging] results in over-diagnosis of insignificant tumours, and systematically misses disease in the anterior prostate. Multiparametric MRI has the potential to change this pathway, and if performed before biopsy, might enable the exclusion of significant disease in some men without biopsy, targeted biopsy in others, and improvements in the performance of active surveillance. For the potential benefits to be realized, the setting of standards is vital. This article summarizes the outcome of a meeting of UK radiologists, at which a consensus was achieved on (1) the indications for MRI, (2) the conduct of the scan, (3) a method and template for reporting, and (4) minimum standards for radiologists.

Human primary gastric dendritic cells induce a Th1 response to H. pylori.

Adaptive CD4 T-cell responses are important in the pathogenesis of chronic Helicobacter pylori gastritis. However, the gastric antigen-presenting cells that induce these responses have not yet been identified. Here we show that dendritic cells (DCs) are present in the gastric mucosa of healthy subjects and are more prevalent and more activated in the gastric mucosa of H. pylori-infected subjects. H. pylori induced gastric DCs isolated from noninfected subjects to express increased levels of CD11c, CD86 and CD83, and to secrete proinflammatory cytokines, particularly interleukin (IL)-6 and IL-8. Importantly, gastric DCs pulsed with live H. pylori, but not control DCs, mediated T-cell secretion of interferon-gamma. The ability of H. pylori to induce gastric DC maturation and stimulate gastric DC activation of Th1 cells implicates gastric DCs as initiators of the immune response to H. pylori.

High resolution stereoscopic volume visualization of the mouse arginine vasopressin system.

New imaging technologies have increased our capabilities to resolve three-dimensional structures from microscopic samples. Laser-scanning confocal microscopy is particularly amenable to this task because it allows the researcher to optically section biological samples, creating three-dimensional image volumes. However, a number of problems arise when studying neural tissue samples. These include data set size, physical scanning restrictions, volume registration and display. To deal with these issues, we undertook large-scale confocal scanning microscopy in order to visualize neural networks spanning multiple tissue sections. We demonstrate a technique to create and visualize a three-dimensional digital reconstruction of the hypothalamic arginine vasopressin neuroendocrine system in the male mouse. The generated three-dimensional data included a volume of tissue that measures 4.35 mm x 2.6 mm x 1.4mm with a voxel resolution of 1.2 microm. The dataset matrix included 3508 x 2072 x 700 pixels and was a composite of 19,600 optical sections. Once reconstructed into a single volume, the data is suitable for interactive stereoscopic projection. Stereoscopic imaging provides greater insight and understanding of spatial relationships in neural tissues' inherently three-dimensional structure. This technique provides a model approach for the development of data sets that can provide new and informative volume rendered views of brain structures. This study affirms the value of stereoscopic volume-based visualization in neuroscience research and education, and the feasibility of creating large-scale high resolution interactive three-dimensional reconstructions of neural tissue from microscopic imagery.

Influence of complications and extent of weight loss on quality of life after laparoscopic Roux-en-Y gastric bypass.

INTRODUCTION: Obesity decreases health-related quality of life, but bariatric surgery improves it. This study evaluates the effect of laparoscopic Roux-en-Y gastric bypass, postoperative complications, and percentage of excess body weight loss on quality of life. METHODS: SF-36v.1 questionnaires were administered preoperative (n = 505), 1 year (n = 237) and 2 years (n = 106) following laparoscopic Roux-en-Y gastric bypass. Analysis was performed using Student's t-test and multiple logistic regression analysis. Complications were defined as requiring additional intervention or hospitalization. SF-36 responses were normalized to 1998 US norms. RESULTS: Bariatric patients scored significantly lower on all scales compared to the normal population. Health-related quality of life notably improves after surgery. At 1 year, scores not only improved from baseline, but were higher than those of the non-obese reference population regardless of complications. Compared to patients at 2 years without complications, patients experiencing complications reported decreased scores, but scores remained higher than preoperative scores in five scales. At 1 and 2 years, < or = 50% excess body weight loss decreased scores; however, scores were significantly improved from baseline. CONCLUSIONS: Health-related quality of life in bariatric patients is worse than in controls, but it improves 1 and 2 years after laparoscopic Roux-en-Y gastric bypass. Complications or < or = 50% excess body weight loss slightly decreases this improvement.

Cuffed endotracheal tube use in paediatric prehospital intubation: challenging the doctrine?

Questioning traditional doctrines is essential if patient care is to improve and progress. Historically accepted teaching is to use uncuffed tubes in all children up to puberty. This has been the practice in anaesthesia, intensive care and paediatric resuscitation both in and out of hospital. The use of cuffed endotracheal tubes (ETTs) in pre-pubertal children is evolving in general anaesthesia and intensive care in hospital practice. In contrast, uncuffed tubes are still widely recommended for use in the prehospital environment in this age group. There are a number of good reasons why a cuffed tube should be considered in preference to an uncuffed tube in children intubated out of hospital, regardless of their age or size. There are also some counterarguments which are worthy of consideration. This article presents the arguments for and against the use of cuffed tubes in children in prehospital care with a view to stimulating open discussion and debate.

Water-soluble upper GI based on clinical findings is reliable to detect anastomotic leaks after laparoscopic gastric bypass.

Anastomotic leak after laparoscopic Roux-en-Y gastric bypass (LGB) is a major complication that must be recognized and treated early for best results. There is controversy in the literature regarding the reliability of upper GI series (UGI) in diagnosing leaks. LGB was performed in patients meeting NIH criteria for the surgical treatment of morbid obesity. All leaks identified at the time of surgery were repaired with suture and retested. Drains were placed at the surgeon's discretion. Postoperatively, UGI was performed by an experienced radiologist if there was a clinical suspicion of leak. From September 2001 until October 2004, a total of 553 patients (age 40.4 +/- 9.2 years, BMI 48.6 +/- 7.2) underwent LGB at UAB. Seventy-eight per cent (431 of 553) of patients had no clinical evidence suggesting anastomotic leak and were managed expectantly. Twenty-two per cent (122 of 553) of patients met at least one inclusion criteria for leak and underwent UGI. Four of 122 patients (3.2%) had a leak, two from anastomosis and two from the perforation of the stapled end of the Roux limb. No patient returned to the operating room without a positive UGI. High clinical suspicion and selectively performed UGI based on clinical evidence is reliable in detecting leaks.

Facilitation of brain stimulation reward by MK-801 (dizocilpine) may be independent of D2-like dopamine receptor stimulation in rats.

RATIONALE: Dopamine (DA) and glutamate (Glu) interactions in the mesocorticolimbic pathway may regulate motivation and reward and contribute to schizophrenia and drug abuse. We have recently demonstrated synergistic effects of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor blockade and D(2/3) DA receptor stimulation in brain stimulation reward (BSR). OBJECTIVES: This study was conducted to explore interactions between DA and Glu systems in BSR using the NMDA receptor antagonist MK-801 and the DA receptor agonists 7-OH-DPAT and apomorphine. METHODS: Systemic effects of these compounds were measured in male Sprague-Dawley rats using rate-frequency threshold analysis of ventral tegmental area (VTA) BSR (n=27). Effects of bilateral applications of MK-801 and 7-OH-DPAT into the nucleus accumbens (NAS) shell subregion were also investigated (n=10). RESULTS: MK-801 (0.03 or 0.13 mg kg(-1) i.p. or 0.66 mug intra-NAS) reduced reward thresholds while 7-OH-DPAT (0.03 mg kg(-1) s.c. or 5.0 microg intra-NAS) or apomorphine (0.05 mg kg(-1), s.c.) increased this measure. MK-801 combined with apomorphine or with 7-OH-DPAT, systemically or in the NAS shell, induced additive effects. CONCLUSIONS: Lack of interaction between DA agonists and MK-801 in this study contrasts with our previous work showing synergistic reward-decreased effects of AMPA/kainate receptor blockade and D(2/3) DA receptor stimulation in the NAS shell, and indicates possible independence of DA and N-methyl-D-aspartate (NMDA) receptor effects in VTA electrical self-stimulation.