Metabolic Responses Research Articles

Metastatic pancreatic and lung cancer patient in complete remission following immunotherapy: A case report and review of literature

BACKGROUND Metastatic pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with dispiriting survival data. Immunotherapy is a promising approach to many cancer types, but achieves poor outcomes in advanced PDAC due to its immunosuppressive tumor microenvironment. We describe a case of metastatic PDAC effectively treated with pembrolizumab. CASE SUMMARY We report the case of a 67-year-old woman with unresectable locally advanced PDAC, treated with gemcitabine plus nab-paclitaxel followed by radiotherapy plus capecitabine. At nine months, pancreatic tumor progression was observed at the level of the hepatic hilum with the appearance of a new pulmonary nodule suggestive of a second primary, confirmed by left lung biopsy. Systemic immunotherapy was then initiated with pembrolizumab, an immune checkpoint inhibitor targeting programmed cell death protein-1 that covers the two tumor types. The patient showed a complete metabolic response that was maintained throughout the treatment. The patient continues to be disease-free at 5.6 years since the start of immunotherapy. CONCLUSION These results suggest that the administration of pembrolizumab after chemoradiotherapy has a beneficial effect in patients with metastatic PDAC. To our knowledge, this is the first reported case of a patient with metastatic PDAC and metastatic lung cancer showing such a long-lasting complete response after pembrolizumab treatment without curative surgery. Further studies are required to determine biomarkers that identify PDAC patients most likely to benefit from this immunotherapy.

Western diet increases brain metabolism and adaptive immune responses in a mouse model of amyloidosis

Diet-induced increase in body weight is a growing health concern worldwide. Often accompanied by a low-grade metabolic inflammation that changes systemic functions, diet-induced alterations may contribute to neurodegenerative disorder progression as well. This study aims to non-invasively investigate diet-induced metabolic and inflammatory effects in the brain of an APPPS1 mouse model of Alzheimer’s disease. [18F]FDG, [18F]FTHA, and [18F]GE-180 were used for in vivo PET imaging in wild-type and APPPS1 mice. Ex vivo flow cytometry and histology in brains complemented the in vivo findings. 1H- magnetic resonance spectroscopy in the liver, plasma metabolomics and flow cytometry of the white adipose tissue were used to confirm metaflammatory condition in the periphery. We found disrupted glucose and fatty acid metabolism after Western diet consumption, with only small regional changes in glial-dependent neuroinflammation in the brains of APPPS1 mice. Further ex vivo investigations revealed cytotoxic T cell involvement in the brains of Western diet-fed mice and a disrupted plasma metabolome. 1H-magentic resonance spectroscopy and immunological results revealed diet-dependent inflammatory-like misbalance in livers and fatty tissue. Our multimodal imaging study highlights the role of the brain-liver-fat axis and the adaptive immune system in the disruption of brain homeostasis in amyloid models of Alzheimer’s disease.

Physiological and metabolic responses of Lolium perenne L. roots to acid stress in cadmium-contaminated soil

Physiological and metabolic responses of Lolium perenne L. roots to acid stress in cadmium-contaminated soil

Joint EANM-SNMMI guideline on the role of 2-[18F]FDG PET/CT in no special type breast cancer : (endorsed by the ACR,ESSO, ESTRO, EUSOBI/ESR, and EUSOMA).

There is much literature about the role of 2-[18F]FDG PET/CT in patients with breast cancer (BC). However, there exists no international guideline with involvement of the nuclear medicine societies about this subject. To provide an organized, international, state-of-the-art, and multidisciplinary guideline, led by experts of two nuclear medicine societies (EANM and SNMMI) and representation of important societies in the field of BC (ACR, ESSO, ESTRO, EUSOBI/ESR, and EUSOMA). Literature review and expert discussion were performed with the aim of collecting updated information regarding the role of 2-[18F]FDG PET/CT in patients with no special type (NST) BC and summarizing its indications according to scientific evidence. Recommendations were scored according to the National Institute for Health and Care Excellence (NICE) criteria. Quantitative PET features (SUV, MTV, TLG) are valuable prognostic parameters. In baseline staging, 2-[18F]FDG PET/CT plays a role from stage IIB through stage IV. When assessing response to therapy, 2-[18F]FDG PET/CT should be performed on certified scanners, and reported either according to PERCIST, EORTC PET, or EANM immunotherapy response criteria, as appropriate. 2-[18F]FDG PET/CT may be useful to assess early metabolic response, particularly in non-metastatic triple-negative and HER2+ tumours. 2-[18F]FDG PET/CT is useful to detect the site and extent of recurrence when conventional imaging methods are equivocal and when there is clinical and/or laboratorial suspicion of relapse. Recent developments are promising. 2-[18F]FDG PET/CT is extremely useful in BC management, as supported by extensive evidence of its utility compared to other imaging modalities in several clinical scenarios.

Comparative Analysis of Circulating Metabolomic Profiles Identifies Shared Metabolic Alterations Across Distinct Multi-Stressor Military Training Operations.

Military training provides insight into metabolic responses under unique physiological demands that can be comprehensively characterized by global metabolomic profiling to identify potential strategies for improving performance. This study identified shared changes in metabolomic profiles across three distinct military training exercises varying in magnitude and types of stress. Blood samples collected before and after three real or simulated military training exercises were analyzed using the same untargeted metabolomic profiling platform. Exercises included a three-week survival school course (ST, n=36), a four-day arctic cross country ski march (AT, n=24), and a 28-day controlled diet- and exercise-induced energy deficit (CED, n=26). Log2-fold changes of >±1 in 191, 121 and 64 metabolites were identified in the ST, AT and CED datasets, respectively. Most metabolite changes were within lipid (57-63%) and amino acid metabolism (18-19%) pathways, and changes in 87 were shared across studies. The largest and most consistent increases in shared metabolites were found in acylcarnitine, fatty acid, ketone, and glutathione metabolism pathways, whereas the largest decreases were in diacylglycerol and urea cycle metabolism pathways. Multiple shared metabolites were consistently correlated with biomarkers of inflammation, tissue damage, and anabolic hormones across studies. These three studies of real and simulated military training revealed overlapping alterations in metabolomic profiles despite differences in environment and the stressors involved. Consistent changes in metabolites related to lipid metabolism, ketogenesis and oxidative stress suggest a potential common metabolomic signature associated with inflammation, tissue damage and suppression of anabolic signaling that may characterize unique physiological demands of military training.

Dynamic Arabidopsis P5CS filament facilitates substrate channelling.

In plants, the rapid accumulation of proline is a common response to combat abiotic stress1-7. Delta-1-pyrroline-5-carboxylate synthase (P5CS) is a rate-limiting enzyme in proline synthesis, catalysing the initial two-step conversion from glutamate to proline8. Here we determine the first structure of plant P5CS. Our results show that Arabidopsis thaliana P5CS1 (AtP5CS1) and P5CS2 (AtP5CS2) can form enzymatic filaments in a substrate-sensitive manner. The destruction of AtP5CS filaments by mutagenesis leads to a significant reduction in enzymatic activity. Furthermore, separate activity tests on two domains reveal that filament-based substrate channelling is essential for maintaining the high catalytic efficiency of AtP5CS. Our study demonstrates the unique mechanism for the efficient catalysis of AtP5CS, shedding light on the intricate mechanisms underlying plant proline metabolism and stress response.

A biofloc system avoids the adverse effects of diets with suboptimal protein levels on zootechnical performance, intestinal histomorphometry, and protein metabolism of Nile tilapia juvenile fed Spirulina biomass (Arthrospira platensis) as an alternative protein source.

This study aimed to evaluate the effect of the biofloc technology (BFT) system and the replacement of fish meal with Spirulina biomass on productive performance, intestinal histomorphometry, plasma biochemistry, and oxidative stress of Nile tilapia juveniles (Oreochromis niloticus) fed suboptimal levels of protein. Two factors were evaluated: production systems (clear water × BFT) and replacement of fish meal with Spirulina (0, 33, 66 e 100%). The design was in a 2 × 4 randomized factorial scheme with four replications, and the fish were evaluated for 48days. Four isoproteic (28% crude protein) diets were formulated with gross energy values close to 4300kcalkg-1. Nile tilapia juveniles (0.23 ± 0.01g) were distributed in 16 circular tanks (70 L) at seven fish/tank. The diets were formulated with protein levels approximately 20% below that required for the species and life stage. No interaction was observed between the factors evaluated (production systems × Spirulina inclusion). Rearing the fish in the BFT system avoided the adverse effects of diets with suboptimal protein levels on performance, intestinal histomorphometry, and protein metabolism. Lower values lower lipid peroxidation and higher antioxidant capacity were observed in fish reared in the BFT system, showing evidence of improvements in antioxidant responses and lower levels of physiological oxidative stress. Spirulina completely replaced fish meal in the diets of Nile tilapia juveniles without adverse effects on intestinal morphometry, protein metabolism, and antioxidant response. Replacing 66% of fish meal with Spirulina improved the productive performance, regardless of the rearing system.

Heterologous expression of the maize transcription factor ZmbHLH36 enhances abiotic stress tolerance in Arabidopsis

AbstractBasic helix-loop-helix (bHLH) transcription factors are widely distributed in eukaryotes, and in plants, they regulate many biological processes, such as cell differentiation, development, metabolism, and stress responses. Few studies have focused on the roles of bHLH transcription factors in regulating growth, development, and stress responses in maize (Zea mays), even though such information would greatly benefit maize breeding programs. In this study, we cloned the maize transcription factor gene ZmbHLH36 (Gene ID: 100193615, GRMZM2G008691). ZmbHLH36 possesses conserved domains characteristic of the bHLH family. RT-qPCR analysis revealed that ZmbHLH36 was expressed at the highest level in maize roots and exhibited different expression patterns under various abiotic stress conditions. Transgenic Arabidopsis (Arabidopsis thaliana) plants heterologously expressing ZmbHLH36 had significantly longer roots than the corresponding non-transgenic plants under 0.1 and 0.15 mol L−1 NaCl treatment as well as 0.2 mol L−1 mannitol treatment. Phenotypic analysis of soil-grown plants under stress showed that transgenic Arabidopsis plants harboring ZmbHLH36 exhibited significantly enhanced drought tolerance and salt tolerance compared to the corresponding non-transgenic plants. Malondialdehyde contents were lower and peroxidase activity was higher in ZmbHLH36-expressing Arabidopsis plants than in the corresponding non-transgenic plants. ZmbHLH36 localized to the nucleus when expressed in maize protoplasts. This study provides a systematic analysis of the effects of ZmbHLH36 on root growth, development, and stress responses in transgenic Arabidopsis, laying a foundation for further analysis of its roles and molecular mechanisms in maize.

A Dangerous Couple: Sequential Effect of Phosphorus Flame-Retardant and Polyurethane Decrease Locomotor Activity in Planarian Girardia tigrina

Understanding the interplay among organophosphorus flame retardants (OPFRs), microplastics, and freshwater organisms is crucial for unravelling the dynamics within freshwater environments and foreseeing the potential impacts of organic pollutants and plastic contamination. For that purpose, the present research assessed the exposure impact of 10 mg L−1 flame-retardant aluminium diethylphosphinate (ALPI), 10 μg mg−1liver microplastics polyurethane (PU), and the combination of ALPI and PU on the freshwater planarian Girardia tigrina. The exposure to both ALPI and PU revealed a sequential effect, i.e., a decrease in locomotor activity, while oxidative stress biomarkers (total glutathione, catalase, glutathione S-transferase, lipid peroxidation) and metabolic responses (cholinesterase activity, electron transport system, and lactate dehydrogenase) remained unaffected. Despite this fact, it was possible to observe that the range of physiological responses in exposed organisms varied, in particular in the cases of the electron transport system, cholinesterase activity, glutathione S-transferase, catalase, and levels of total glutathione and proteins, showing that the energetic costs for detoxification and antioxidant capacity might be causing a lesser amount of energy allocated for the planarian activity. By examining the physiological, behavioural, and ecological responses of planarians to these pollutants, insights can be gained into broader ecosystem-level effects and inform strategies for mitigating environmental risks associated with OPFRs and microplastic pollution in freshwater environments.

Characterization of ZmSnRK1 genes and their response to aphid feeding, drought and cold stress

AbstractThe SnRK1 complex in plants regulates metabolism in response to environmental stresses and glucose depletion, for stress adaptation and energy homeostasis. Through phosphorylation of various targets, SnRK1 orchestrates intricate regulatory mechanisms involved in autophagy, nutrient remobilization, and TOR activity inhibition, showcasing its pivotal role in coordinating plant metabolism and stress responses. The present study aimed to identify members of the SnRK1 gene family in the maize genome and characterize them using bioinformatics and expression analyses under aphid feeding, drought, and cold stress. The focus of the study was to conduct a comprehensive analysis towards determining gene diversity of ZmSnRK1 genes, constructing intricate 3D structures, and identifying stress-related cis-elements. Four SnRK1 genes were identified, which were named ZmSnRK1.1, ZmSnRK1.2, ZmSnRK1.3, and ZmSnRK1.4. The SnRK1 proteins were found to have a distribution of conserved motifs; however, the distinction between monocots and dicots in the phylogenetic tree was clearly demonstrated. Analysis of the promoter region revealed that the ZmSnRK1 genes contain stress-related cis-elements. Compared to the control, ZmSnRK1.3 significantly upregulated in response to aphid feeding and cold stress, while ZmSnRK1.2 showed elevated expression under drought conditions. The expression of the other two genes under these treatments was generally unperturbed. The findings of this study are poised to establish a valuable scientific foundation for future research on the roles of the SnRK1 gene family in plants, providing valuable insights for enhancing genetic resilience to stress and optimizing yield traits.

Genomic landscapes of divergence among island bird populations: Evidence of parallel adaptation but at different loci?

When populations colonise new environments, they may be exposed to novel selection pressures but also suffer from extensive genetic drift due to founder effects, small population sizes and limited interpopulation gene flow. Genomic approaches enable us to study how these factors drive divergence, and disentangle neutral effects from differentiation at specific loci due to selection. Here, we investigate patterns of genetic diversity and divergence using whole-genome resequencing (>22× coverage) in Berthelot's pipit (Anthus berthelotii), a passerine endemic to the islands of three north Atlantic archipelagos. Strong environmental gradients, including in pathogen pressure, across populations in the species range, make it an excellent system in which to explore traits important in adaptation and/or incipient speciation. First, we quantify how genomic divergence accumulates across the speciation continuum, that is, among Berthelot's pipit populations, between sub species across archipelagos, and between Berthelot's pipit and its mainland ancestor, the tawny pipit (Anthus campestris). Across these colonisation timeframes (2.1 million-ca. 8000 years ago), we identify highly differentiated loci within genomic islands of divergence and conclude that the observed distributions align with expectations for non-neutral divergence. Characteristic signatures of selection are identified in loci associated with craniofacial/bone and eye development, metabolism and immune response between population comparisons. Interestingly, we find limited evidence for repeated divergence of the same loci across the colonisation range but do identify different loci putatively associated with the same biological traits in different populations, likely due to parallel adaptation. Incipient speciation across these island populations, in which founder effects and selective pressures are strong, may therefore be repeatedly associated with morphology, metabolism and immune defence.

Effects of dietary nitrogen and/or phosphorus reduction on mineral homeostasis and regulatory mechanisms in young goats

IntroductionThe reduction of nitrogen (N) and phosphorus (P) in ruminant feed is desirable due to costs and negative environmental impact. Ruminants are able to utilize N and P through endogenous recycling, particularly in times of scarcity. When N and/or P were reduced, changes in mineral homeostasis associated with modulation of renal calcitriol metabolism occurred. The aim of this study was to investigate the potential effects of dietary N- and/or P-reduction on the regulatory mechanisms of mineral transport in the kidney and its hormonal regulation in young goats.ResultsDuring N-reduction, calcium (Ca) and magnesium (Mg) concentrations in blood decreased, accompanied by a lower protein expression of cytochrome P450 family 27 subfamily B member 1 (CYP27B1) (p = 0.016). The P-reduced fed goats had low blood phosphate concentrations with simultaneously high Ca and Mg levels. The insulin-like growth factor 1 concentrations decreased significantly with P-reduction. Furthermore, gene expression of CYP27B1 (p < 0.001) and both gene (p = 0.025) and protein (p = 0.016) expression of the fibroblast growth factor receptor 1c isoform in the kidney were also significantly reduced during a P-reduced diet. ERK1/2 activation exhibited a trend toward reduction in P-reduced animals. Interestingly, calcitriol concentrations remained unaffected by either restriction individually, but interacted significantly with N and P (p = 0.014). Additionally, fibroblast growth factor 23 mRNA expression in bone decreased significantly with P-restriction (p < 0.001).DiscussionThese results shed light on the complex metabolic and regulatory responses of mineral transport of young goats to dietary N and P restriction.

Functional characterization of helminth-associated Clostridiales reveals covariates of Treg differentiation

BackgroundParasitic helminths influence the composition of the gut microbiome. However, the microbiomes of individuals living in helminth-endemic regions are understudied. The Orang Asli, an indigenous population in Malaysia with high burdens of the helminth Trichuris trichiura, display microbiotas enriched in Clostridiales, an order of spore-forming obligate anaerobes with immunogenic properties. We previously isolated novel Clostridiales that were enriched in these individuals and found that a subset promoted the Trichuris life cycle. In this study, we aimed to further characterize the functional properties of these bacteria.ResultsClostridiales isolates were profiled for their ability to perform 57 enzymatic reactions and produce short-chain fatty acids (SCFAs) and hydrogen sulfide, revealing that these bacteria were capable of a range of activities associated with metabolism and host response. Consistent with this finding, monocolonization of mice with individual isolates identified bacteria that were potent inducers of regulatory T-cell (Treg) differentiation in the colon. Comparisons between variables revealed by these studies identified enzymatic properties correlated with Treg induction and Trichuris egg hatching.ConclusionWe identified Clostridiales species that are sufficient to induce high levels of Tregs. We also identified a set of metabolic activities linked with Treg differentiation and Trichuris egg hatching mediated by these newly isolated bacteria. Altogether, this study provides functional insights into the microbiotas of individuals residing in a helminth-endemic region.-EyM7p7tfAvrAjtAePB85JVideo

Surviving a Double-Edged Sword: Response of Horticultural Crops to Multiple Abiotic Stressors

Climate change-induced weather events, such as extreme temperatures, prolonged drought spells, or flooding, pose an enormous risk to crop productivity. Studies on the implications of multiple stresses may vary from those on a single stress. Usually, these stresses coincide, amplifying the extent of collateral damage and contributing to significant financial losses. The breadth of investigations focusing on the response of horticultural crops to a single abiotic stress is immense. However, the tolerance mechanisms of horticultural crops to multiple abiotic stresses remain poorly understood. In this review, we described the most prevalent types of abiotic stresses that occur simultaneously and discussed them in in-depth detail regarding the physiological and molecular responses of horticultural crops. In particular, we discussed the transcriptional, posttranscriptional, and metabolic responses of horticultural crops to multiple abiotic stresses. Strategies to breed multi-stress-resilient lines have been presented. Our manuscript presents an interesting amount of proposed knowledge that could be valuable in generating resilient genotypes for multiple stressors.

Phoenixin knockout mice show no impairment in fertility or differences in metabolic response to a high-fat diet, but exhibit behavioral differences in an open field test.

Phoenixin (PNX) is a conserved secreted peptide that was identified 10 years ago with numerous studies published on its pleiotropic functions. PNX is associated with estrous cycle length, protection from a high-fat diet, and reduction of anxiety behavior. However, no study had yet evaluated the impact of deleting PNX in the whole animal. We sought to evaluate a mouse model lacking the PNX parent gene, small integral membrane protein 20 (Smim20), and the resulting effect on reproduction, energy homeostasis, and anxiety. We found that the Smim20 knockout mice had normal fertility and estrous cycle lengths. Consistent with normal fertility, the hypothalamii of the knockout mice showed no changes in the levels of reproduction-related genes, but the male mice had some changes in energy homeostasis-related genes, such as melanocortin receptor 4 (Mc4r). When placed on a high-fat diet, the wildtype and knockout mice responded similarly, but the male heterozygous mice gained slightly less weight. When placed in an open field test box, the female knockout mice traveled less distance in the outer zone, indicating alterations in anxiety or locomotor behavior. In summary, the homozygous knockout of PNX did not alter fertility and modestly alters a few neuroendocrine genes in response to a high-fat diet, especially in the female mice. However, it altered the behavior of mice in an open field test. PNX therefore may not be crucial for reproductive function or weight, however, we cannot rule out possible compensatory mechanisms in the knockout model. Understanding the role of PNX in physiology may ultimately lead to an enhanced understanding of neuroendocrine mechanisms involving this enigmatic peptide.

Driving Role of Zinc Oxide Nanoparticles with Different Sizes and Hydrophobicity in Metabolic Response and Eco-Corona Formation in Sprouts (Vigna radiata).

Zinc oxide nanoparticles (ZnO NPs) cause biotoxicity and pose a potential ecological threat; however, their effects on plant metabolism and eco-corona evolution between NPs and organisms remain unclear. This study clarified the molecular mechanisms underlying physiological and metabolic responses induced by three different ZnO NPs with different sizes and hydrophobicity in sprouts (Vigna radiata) and explored the critical regulation of eco-corona formation in root-nano systems. Results indicated that smaller-sized ZnO inhibited root elongation by up to 37.14% and triggered oxidative burst and apoptosis. Metabolomics confirmed that physiological maintenance after n-ZnO exposure was mainly attributed to the effective stabilization of nitrogen fixation and defense systems by biotransformation of the flavonoid pathway. Larger-sized or hydrophobic group-modified ZnO exhibited low toxicity in sprouts, with 0.89-fold upregulation of citrate in central carbon metabolism. This contributed to providing energy for resistance to NP stress through amino acid and carbon/nitrogen metabolism, accompanied by changes in membrane properties. Notably, smaller-sized and hydrophobic NPs intensely stimulated the release of root metabolites, forming corona complexes with exudates. The hydrogen-bonded wrapping mechanism in protein secondary structure and hydrophobic interactions of heterogeneous functional groups drove eco-corona formation, along with the corona evolution intensity of n-ZnO > s-ZnO > b-ZnO based on higher (α-helix + 3-turn helix)/β-sheet ratios. This study provides crucial insight into metabolic and eco-corona evolution in bionano fates.

Adverse Outcome Phenomena and Toxicity Mechanisms of Micro and Nanoplastics in Human Health

The ubiquitous presence of micro and nanoplastics (MNPs) in the environment has become a pressing global concern, particularly regarding the potential impacts on human health. This review underscores the urgent need for an integrative research framework that bridges the gap between epidemiological observations and toxicological insights. Human exposure to MNPs occurs predominantly through ingestion, inhalation and dermal contact pathways. Epidemiological findings have consistently demonstrated the presence of MNPs in diverse human tissues, signaling a broad exposure and emphasizing the imperative to explore potential health risks. Population surveys have shown that the concentration of MNPs in the feces of people using disposable plastic tableware reaches 24.65 items/g. These results are associated with changes in microbiota composition and metabolite levels relevant to central nervous system disorders, energy metabolism and inflammatory responses. The detectable abundance of MNPs in the nasal mucus of individuals wearing N95 masks was measured to be 10.6 ± 2.3 items/mg. Moreover, population-based studies have linked MNP exposure to adverse health outcomes, suggesting correlation relationships between exposure levels and specific diseases such as inflammatory bowel disease (IBD) and human pulmonary ground-glass nodules (GGN). These associations underscore the necessity for in-depth toxicological investigations to elucidate the toxicity mechanisms of MNPs. Meanwhile, laboratory-based toxicological studies have the potential to reveal causative relationships and various in vitro and in vivo models have been used to explore the mechanisms of the toxicity of MNPs in the gastrointestinal tract, lungs and cardiovascular system. However, early studies failed to reflect on the complexity of the real environment. To foster interdisciplinary collaborations, this paper aims to reconcile the disparities between exposure risks and human health impacts. By critically reviewing recent advancements in understanding the exposure risks of MNPs, epidemiological observations and organ-specific toxicity, this work furnishes a comprehensive perspective on the health implications of MNPs.

Exercise Influences the Brain’s Metabolic Response to Chronic Cocaine Exposure in Male Rats

Cocaine use is associated with negative health outcomes: cocaine use disorders, speedballing, and overdose deaths. Currently, treatments for cocaine use disorders and overdose are non-existent when compared to opioid use disorders, and current standard cocaine use disorder treatments have high dropout and recidivism rates. Physical exercise has been shown to attenuate addiction behavior as well as modulate brain activity. This study examined the differential effects of chronic cocaine use between exercised and sedentary rats. The effects of exercise on brain glucose metabolism (BGluM) following chronic cocaine exposure were assessed using Positron Emission Tomography (PET) and [18F]-Fluorodeoxyglucose (FDG). Compared to sedentary animals, exercise decreased metabolism in the SIBF primary somatosensory cortex. Activation occurred in the amygdalopiriform and piriform cortex, trigeminothalamic tract, rhinal and perirhinal cortex, and visual cortex. BGluM changes may help ameliorate various aspects of cocaine abuse and reinstatement. Further investigation is needed into the underlying neuronal circuits involved in BGluM changes and their association with addiction behaviors.

Disappearance of "Elongated Pony Tail Sign" Following Chemoradiotherapy in a Case of Primary Cerebellopontine Angle Ependymoma With Spinal Drop Metastasis: 18F-FDG PET/CT Scan Findings.

Ependymomas are rare glial tumors that commonly arise from the lining cells of ventricular system and constitute ~10% of intracranial pediatric malignancies. The incidence of ependymoma in adults is rare. Due to close approximation with the ventricular system, subtentorial ependymomas are more prone to show cerebrospinal fluid metastasis compared with supratentorial ependymomas. We present a case of subtentorial cerebellopontine angle ependymoma with diffuse spinal drop metastases showing "elongated pony tail appearance" in a 69-year-old man with complete metabolic response on 18F-FDG PET/CT imaging following chemoradiotherapy.

Compartmental analysis: a new approach to estimate protein breakdown and meal response in health and critical illness

Purpose of reviewThis study aimed to discuss the use of the pulse stable isotope tracer approach to study changes in metabolism in healthy individuals and critically ill patients.Recent findings and conclusionWe found that in the postabsorptive state and healthy condition, intracellular protein breakdown and net intracellular protein breakdown, when calculated using the pulse tracer approach, are about double what has previously been reported using the more traditional primed-constant and continuous stable isotope approaches (600 versus 300 grams of protein/day). In critically ill patients, protein breakdown is even higher and calculated to be approximately 900 grams of protein/day, using the pulse tracer approach. Based on these data, we hypothesize that reducing protein breakdown in the postabsorptive state is key when trying to improve the condition of critically ill patients. Moreover, we also used the pulse tracer approach during feeding to better estimate the intracellular metabolic response to feeding. Our first observation is that endogenous protein breakdown does not seem to be reduced during feeding. We also have shown that when consuming a meal with a certain amount of protein, the biological value of that protein meal can be calculated with the pulse tracer approach. In conclusion, using the pulse stable isotope tracer approach to study protein kinetics in the postabsorptive state and during feeding expands our understanding of how dietary proteins can affect human protein metabolism. The intracellular protein synthesis stimulatory effect of a meal is an important factor to consider when calculating the exact protein requirements and needs, particularly in critical illness.