Determination of fatty acid uptake and desaturase activity in mammalian cells by NMR-based stable isotope tracing

BACKGROUND

Mammalian cells both import exogenous fatty acids and synthesize them de novo. Palmitate, the end product of fatty acid synthase (FASN) is a substrate for stearoyl-CoA desaturases (Δ-9 desaturases) that introduce a single double bond into fatty acyl-CoA substrates such as palmitoyl-CoA and stearoyl-CoA. This process is particularly upregulated in lipogenic tissues and cancer cells. Tracer methodology is needed to determine uptake versus de novo synthesis of lipids and subsequent chain elongation and desaturation. Here we describe an NMR method to determine the uptake of 13C-palmitate from the medium into HCT116 human colorectal cancer cells, and the subsequent desaturation and incorporation into complex lipids.

RESULTS

Exogenous 13C16-palmitate was absorbed from the medium by HCT116 cells and incorporated primarily into complex glycerol lipids. Desaturase activity was determined from the quantification of double bonds in acyl chains, which was greatly reduced by ablation of the major desaturase SCD1.

SIGNIFICANCE

The NMR approach requires minimal sample preparation, is non-destructive, and provides direct information about the level of saturation and incorporation of fatty acids into complex lipids.

[The preliminary application of mNGS in the diagnosis of invasive fungal sinusitis]

Objective: By conducting a retrospective analysis of the clinical data of 14 patients diagnosed with invasive fungal rhinosinusitis (IFRS) confirmed by metagenomics next generation sequencing (mNGS) technology, we aim to explore the rapid diagnosis value of mNGS in IFRS. Methods: The clinical data of 14 IFRS patients admitted to TianJin First Central Hospital were retrospectively analyzed from February 2021 to October 2023. The study cohort comprised 8 males and 6 females, with ages ranging from 14 to 77 years. All patients were diagnosed as IFRS by performing mNGS sequencing technology of nasal sinus lesion biopsy specimens. Clinical data such as laboratory examination, imaging examination, histopathological examination results, treatment plan and prognosis were summarized and analyzed. Results: All 14 patients were diagnosed as IFRS, with mNGS detecting pathogens such as Rhizopus (7 cases), Aspergillus (5 cases), Trichoderma (1 case), and Scedosporium apiospermum (1 case). Follow-up evaluations were conducted for a period ranging from 2 months to 2 years post-treatment. At the end of follow-up, 11 out of 14 IFRS patients achieved a complete cure with no signs of recurrence, while the symptoms of the remaining 3 patients significantly improved with comprehensive treatment. Conclusion: mNGS emerges as a highly effective diagnostic tool for IFRS, providing valuable microbiological evidence for clinical diagnosis and demonstrating promising clinical utility.

Comparison of conventional and endoscope-assisted partial clretain-->superficial parotidectomy for benign neoplasms of the parotid gland: a matched case-control study

Long-term tumour recurrence rates and complications of endoscope-assisted partial superficial parotidectomy (PSP) are rarely reported compared to traditional open approaches. This retrospective study included 306 patients with superficial parotid benign neoplasms who were divided into an endoscopy group (endoscope-assisted PSP, n = 102) and a control group (conventional PSP, n = 204). There were no significant differences in clinical and pathological characteristics between the two groups, except age (P = 0.001). Three patients had confirmed recurrence during a mean follow-up duration of 125.1 months. Ten (9.8%) patients in the endoscopy group and 22 (10.8%) in the control group developed transient facial nerve palsy (P = 0.792), and recovered 6 months after the operation. Nine (8.8%) and 19 (9.3%) patients, respectively, suffered from Frey syndrome (P = 0.889). A sensory deficit of the auricle occurred in 24 (23.5%) and 57 (27.9%) patients respectively (P = 0.410). Patients in the endoscopy group were more satisfied with the postoperative scar than those in the control group (P < 0.001). This study demonstrated that the endoscope-assisted PSP can be curative, with better cosmetic outcomes than the conventional approach, and does not increase the incidence of postoperative complications or the local recurrence rate.

Clinical study of tirofiban compared to low molecular weight heparin in the antithrombotic treatment of progressive pontine infarction

OBJECTIVE

To investigate the efficacy and safety of tirofiban and low molecular weight heparin (LMWH) in the treatment of patients undergoing acute progressive pontine infarction.

PATIENTS AND METHODS

Patients with acute progressive pontine infarction who were hospitalized in the Neurology Department from June 2021 to June 2023 were included in the study and randomly divided into two groups, namely the experimental group (tirofiban group) and the control group (LMWH group). All patients in both groups were required to receive conventional comprehensive treatment and dual antiplatelet therapy with aspirin + clopidogrel at the beginning of admission. The National Institutes of Health Stroke Scale (NIHSS) score and Barthel Index (BI) were used to evaluate the neurological deficits on the first day of admission, the next day with stroke progression, and at discharge after treatment with tirofiban and LMWH, respectively in the two groups. The modified Rankin Scale was employed to assess prognosis on the 90th day after treatment. Clinical adverse events were followed up for 90 days, comparing the clinical efficacy and safety of the two treatment methods.

RESULTS

There was no statistical significance in NIHSS score and Barthel Index between the tirofiban group and the LMWH group on the first day of admission and the next day with stroke progression (p > 0.05). After stroke progression, tirofiban and LMWH were separately used for treatment in the two groups. We found that the NIHSS score of the tirofiban group was lower than that of the LMWH group, and the Barthel Index score was higher than that of the LMWH group at discharge (p < 0.05). After three months of follow-up, the mRS score of the tirofiban group was dramatically higher than that of the LMWH group (p < 0.05). No significant harmful or adverse reactions, such as bleeding events, were found in the two groups (p > 0.05).

CONCLUSIONS

Tirofiban may be more effective and safer than LMWH in controlling the progression of acute pontine infarction, but further and large-sample studies are still needed to confirm this finding.

[High-risk sexual behaviors of HIV/AIDS and related factors in young students in Guangzhou]

Objective: To explore high-risk sexual behaviors of HIV/AIDS and related factors in young students in Guangzhou. Methods: A cross-sectional survey was conducted in 5 different types of Guangzhou colleges by convenience sampling with minimum number of classes per grade and 600 samples per school from September to November 2021. The R 4.2.2 software was used to consolidate databases. Simultaneously, a logistic regression model and a decision tree algorithm model, stratifying by whether sexual behaviors had occurred before, were constructed. In each layer, the prediction performance of the two models was evaluated through area under receiver operating characteristic and the confusion matrix, and then the model with high prediction performance was retained. Results: A total of 7 346 students were surveyed. The proportion of the respondents reporting sexual experience were 9.08% (667/7 346), in whom 26.24% (175/667) had risky sexual activity in the past year. The decision tree algorithm model performs well in predicting whether high-risk sexual behaviors have occurred in the past year. When the complexity parameter value is 0.018, and nsplit reaches 4, which means there are 5 leaf nodes in the model, the cross error of the tree will be the smallest. The first best grouping variable in the decision tree was whether to use condoms throughout the first sexual behavior. If condoms were used at their sexual debut, but homosexual practices have occurred in the past year, the probability of risky sexual behavior will increase. If homosexual practices have not occurred in the past year, but the age of sexual debut was below 18 years old while the period of HIV education was after high school, the probability of risk sexual behavior will also increase. Conclusions: AIDS-related risky behaviors of young students still deserved attention. The experience of sexual debut and whether AIDS-related health education has been received before the sexual debut were significant predictors for the occurrence of high-risk sexual behavior. The decision tree algorithm model has particular applicability for predicting and screening potential risk populations.

Measures of performance and proficiency in robotic assisted surgery: a systematic review

Robotic assisted surgery (RAS) has seen a global rise in adoption. Despite this, there is not a standardised training curricula nor a standardised measure of performance. We performed a systematic review across the surgical specialties in RAS and evaluated tools used to assess surgeons' technical performance. Using the PRISMA 2020 guidelines, Pubmed, Embase and the Cochrane Library were searched systematically for full texts published on or after January 2020-January 2022. Observational studies and RCTs were included; review articles and systematic reviews were excluded. The papers' quality and bias score were assessed using the Newcastle Ottawa Score for the observational studies and Cochrane Risk Tool for the RCTs. The initial search yielded 1189 papers of which 72 fit the eligibility criteria. 27 unique performance metrics were identified. Global assessments were the most common tool of assessment (n = 13); the most used was GEARS (Global Evaluative Assessment of Robotic Skills). 11 metrics (42%) were objective tools of performance. Automated performance metrics (APMs) were the most widely used objective metrics whilst the remaining (n = 15, 58%) were subjective. The results demonstrate variation in tools used to assess technical performance in RAS. A large proportion of the metrics are subjective measures which increases the risk of bias amongst users. A standardised objective metric which measures all domains of technical performance from global to cognitive is required. The metric should be applicable to all RAS procedures and easily implementable. Automated performance metrics (APMs) have demonstrated promise in their wide use of accurate measures.

[Advances in research on the role of immune cells in optic nerve injury]

Optic nerve injury can result in the loss of retinal ganglion cells (RGCs) and their axons, representing a significant cause of irreversible vision impairment. Immune response is a common step following injury, and it often exhibits contrasting effects in optic nerve pathologies. Immune cells play a crucial role in this process, and understanding the differentiation of various immune cells post-injury, mitigating their neurotoxicity, and directing them towards a beneficial outcome for the protection of RGCs and axons are vital for optic nerve preservation. This paper provides a comprehensive review of the research progress on immune cells such as macrophages, microglia, T cells, and others in the field of optic nerve injury. Additionally, discussions include the identification of cell phenotypes and the exploration of the novel concept of innate immunity possibly possessing memory.

Integrated multi-omics profiling to dissect the spatiotemporal evolution of metastatic hepatocellular carcinoma

Comprehensive molecular analyses of metastatic hepatocellular carcinoma (HCC) are lacking. Here, we generate multi-omic profiling of 257 primary and 176 metastatic regions from 182 HCC patients. Primary tumors rich in hypoxia signatures facilitated polyclonal dissemination. Genomic divergence between primary and metastatic HCC is high, and early dissemination is prevalent. The remarkable neoantigen intratumor heterogeneity observed in metastases is associated with decreased T cell reactivity, resulting from disruptions to neoantigen presentation. We identify somatic copy number alterations as highly selected events driving metastasis. Subclones without Wnt mutations show a stronger selective advantage for metastasis than those with Wnt mutations and are characterized by a microenvironment rich in activated fibroblasts favoring a pro-metastatic phenotype. Finally, metastases without Wnt mutations exhibit higher enrichment of immunosuppressive B cells that mediate terminal exhaustion of CD8+ T cells via HLA-E:CD94-NKG2A checkpoint axis. Collectively, our results provide a multi-dimensional dissection of the complex evolutionary process of metastasis.

Metabolic reprogramming driven by EZH2 inhibition depends on cell-matrix interactions

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Polycomb Repressive Complex 2 (PRC2), catalyzes the trimethylation of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 inhibition can be achieved with the FDA-approved drug EPZ-6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems influences this blockade in terms of growth-related metabolic functions. Here, we show that EZH2 suppression reduced growth of human lung adenocarcinoma A549 cells in 2D cultures but stimulated growth in 3D cultures. To understand the metabolic underpinnings, we employed [13C6]-glucose stable isotope-resolved metabolomics to determine the effect of EZH2 suppression on metabolic networks in 2D versus 3D A549 cultures. The Krebs cycle, neoribogenesis, γ-aminobutyrate metabolism, and salvage synthesis of purine nucleotides were activated by EZH2 suppression in 3D spheroids but not in 2D cells, consistent with the growth effect. Using simultaneous 2H7-glucose + 13C5,15N2-Gln tracers and EPZ-6438 inhibition of H3 trimethylation, we delineated the effects on the Krebs cycle, γ-aminobutyrate metabolism, gluconeogenesis, and purine salvage to be PRC2-dependent. Furthermore, the growth/metabolic effects differed for mouse Matrigel versus self-produced A549 extracellular matrix. Thus, our findings highlight the importance of the presence and nature of extracellular matrix in studying the function of EZH2 and its inhibitors in cancer cells for modeling the in vivo outcomes.

[Perception of HIV-related behavior and influencing factors among young students in Guangzhou]

Objective: To investigate the risk perception for risky behavior of HIV/AIDS infection among young students and to analyze the related influencing factors. Methods: A cross-sectional survey was conducted in 5 different types of Guangzhou colleges from September to November 2021, in which convenience sampling and a minimum number of classes per grade and 600 samples per school were used according to the national unity program. Disordered multi-classification logistic regression was used to construct a risk perception model and analyze influencing factors in different risk perception levels. Results: A total of 7 346 young students were surveyed, and most rated themselves at low risk of HIV/AIDS infections (90.58%, 6 654/7 346). A total of 89.10% (6 545/7 346) of subjects' perception of their HIV/AIDS infection risk was consistent with their risk behavior, while 10.90% (801/7 346) was inconsistent. Among those inconsistent subjects, 19.10% (153/801) showed underestimating their risk , while 80.90% (648/801) seen overestimating their risk. Disordered multi-classification logistic regression analysis showed that, after controlling for other factors, compared with the non-sexual group, respondents whose first sex age under 18 had a higher rate of underestimating their risk of infection (OR=129.39, 95%CI: 73.28-228.48), as well as a higher rate of overestimated their risk of infection (OR=1.76, 95%CI: 1.04-2.99). First sexual intercourse at age 18 or older was a risk factor for underestimating risk (OR=70.56, 95%CI: 42.72-116.53), but was not statistically associated with overestimating risk. Being female, other school type, non-heterosexual orientation, and self-rated HIV-related knowledge as fair or no knowledge were risk factors for overestimating risk but were not statistically associated with underestimating risk. Conclusions: Overall, young students in universities of Guangzhou have a good risk perception of HIV/AIDS infection. Individual factors, education factors and sexual experience will influence students' risk perception of HIV/AIDS infection. Raising the awareness rate of HIV/AIDS knowledge and delaying the age of first sexual intercourse will improve the risk perception ability of young students.

Sugary and salty former food products in pig diets affect energy and nutrient digestibility, feeding behaviour but not the growth performance and carcass composition

Former foodstuff products (FFPs) are promising alternative ingredients for reducing the waste of natural resources and the environmental impact of food production. This study investigates the effects of salty and sugary FFPs on growth performance, apparent total tract digestibility (ATTD), and growing-finishing pigs' empty body and carcass composition. Thirty-six Swiss Large White male castrated pigs were assigned to three growing (G) and finishing (F) diets: (1) standard diet (ST), 0% FFPs; (2) 30% conventional ingredients replaced by sugary FFPs (SU); and (3) 30% conventional ingredients replaced by salty FFPs (SA). Faecal samples from 24 selected pigs were collected to assess the ATTD of gross energy, crude fibres, and CP. The BW was measured weekly, while feed intake was determined daily. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), and ATTD were calculated for both the growing and finishing periods. Pigs' body composition was determined at ≥20 and ≥98 kg using dual-energy X-ray absorptiometry. In the growing but not finishing period, the FCR was lower (P < 0.05) in ST compared to SA and SU pigs. Considering the entire growing and finishing period, neither the inclusion level nor the type of FFPs influenced (P > 0.05) ADG, ADFI, FCR, or BW at slaughter. In both the growing and finishing periods, the gross energy ATTD was higher (P < 0.05) in the SA than in the ST group, with intermediate values in the SU group. In the growing period, the CP ATTD was higher (P < 0.05) in the SA than in the SU and ST groups. In the finishing period, the crude fibre ATTD was lower (P < 0.05) in the SA and SU than in the ST group. Throughout the overall period, the average daily fat intake was higher (P < 0.05) in pigs fed an SU diet, even though both categories of FFPs had no (P > 0.05) effects on the parameters related to the pigs' body composition (e.g., average daily fat weight gain). Finally, the carcasses of the SU group had the thickest belly fat, even though the total fat content was similar among the groups. This study confirms that including FFPs has no detrimental effects on growth performance or live body/carcass composition in growing and finishing pigs.

Review: Pig-based bioconversion: the use of former food products to keep nutrients in the food chain

The primary challenge of agriculture and livestock production is to face the growing competition between food, feed, fibre, and fuel, converting them from resource-intensive to resource-efficient. A circular economy approach, using agricultural by-products/co-products, in the livestock production system would allow to reduce, reuse, and redistribute the resources. Former food products (FFPs), also named ex-foods, could represent a valid option in strengthening resilience in animal nutrition. FFPs have a promising potential to be included regularly in animal diets due to their nutritive value, although their potential in animal nutrition remains understudied. A thorough investigation of the compositional and dietary features, thus, is essential to provide new and fundamental insights to effectively reuse FFPs as upgraded products for swine nutrition. Safety aspects, such as the microbial load or the presence of packaging remnants, should be considered with caution. Here, with a holistic approach, we review several aspects of FFPs and their use as feed ingredients: the nutritional and functional evaluation, the impact of the inclusion of FFPs in pigs' diet on growth performance and welfare, and further aspects related to safety and sustainability of FFPs.

HExpPredict: In Vivo Exposure Prediction of Human Blood Exposome Using a Random Forest Model and Its Application in Chemical Risk Prioritization

BACKGROUND

Due to many substances in the human exposome, there is a dearth of exposure and toxicity information available to assess potential health risks. Quantification of all trace organics in the biological fluids seems impossible and costly, regardless of the high individual exposure variability. We hypothesized that the blood concentration (CB) of organic pollutants could be predicted via their exposure and chemical properties. Developing a prediction model on the annotation of chemicals in human blood can provide new insight into the distribution and extent of exposures to a wide range of chemicals in humans.

OBJECTIVES

Our objective was to develop a machine learning (ML) model to predict blood concentrations (CBs) of chemicals and prioritize chemicals of health concern.

METHODS

We curated the CBs of compounds mostly measured at population levels and developed an ML model for chemical CB predictions by considering chemical daily exposure (DE) and exposure pathway indicators (δij), half-lives (t1/2), and volume of distribution (Vd). Three ML models, including random forest (RF), artificial neural network (ANN) and support vector regression (SVR) were compared. The toxicity potential or prioritization of each chemical was represented as a bioanalytical equivalency (BEQ) and its percentage (BEQ%) estimated based on the predicted CB and ToxCast bioactivity data. We also retrieved the top 25 most active chemicals in each assay to further observe changes in the BEQ% after the exclusion of the drugs and endogenous substances.

RESULTS

We curated the CBs of 216 compounds primarily measured at population levels. RF outperformed the ANN and SVF models with the root mean square error (RMSE) of 1.66 and 2.07μM, the mean absolute error (MAE) values of 1.28 and 1.56μM, the mean absolute percentage error (MAPE) of 0.29 and 0.23, and R2 of 0.80 and 0.72 across test and testing sets. Subsequently, the human CBs of 7,858 ToxCast chemicals were successfully predicted, ranging from 1.29×10-6 to 1.79×10-2 μM. The predicted CBs were then combined with ToxCast in vitro bioassays to prioritize the ToxCast chemicals across 12 in vitro assays with important toxicological end points. It is interesting that we found the most active compounds to be food additives and pesticides rather than widely monitored environmental pollutants.

DISCUSSION

We have shown that the accurate prediction of "internal exposure" from "external exposure" is possible, and this result can be quite useful in the risk prioritization. https://doi.org/10.1289/EHP11305.

[Clinical efficacy and prognostic risk factors of salvage liver transplantation, rehepatectomy, and local ablation in the treatment of postoperative recurrence of hepatocellular carcinoma]

Objective: To investigate and analyze the clinical efficacy of salvage liver transplantation (SLT), rehepatectomy (RH), local ablation (LA), and prognostic risk factors in patients with postoperative recurrence of hepatocellular carcinoma. Methods: Clinical data of 145 patients with recurrent liver cancer in the 900th Hospital of the Joint Logistics Support Force of the People's Liberation Army from January 2005 to June 2018 were retrospectively collected. SLT group, RH group, and LA group included 25, 44, and 76 cases, respectively. Follow-up and statistics were recorded on the overall survival rate, relapse-free survival rate, and complications of the three groups of patients at 1, 2, and 3 years after surgery. Univariate and multivariate COX analyses were used to analyze the prognostic risk factors in patients with recurrent HCC. Results: The overall survival rates of 1, 2, and 3 years following surgery in the SLT, RH, and LA groups were 100.0%, 84.0%, 72.0%, 95.5%, 77.3%, 65.9%, 90.8%, 76.3%, and 63.2%, respectively, when the recurrence of liver cancer met the Milan criteria. The overall survival rate did not differ statistically between SLT and RH (P = 0.303) or between RH and LA (P = 0.152). There were statistically significant differences in recurrence-free survival between SLT and RH or RH and LA (P = 0.046). There was no statistically significant difference in the incidence of complications between SLT and RH or RH and LA (P > 0.017). Age > 65 years was an independent risk factor affecting the overall survival rate in patients with recurrent HCC. Age > 65 years and recurrence time < 24 months were independent risk factors affecting the recurrence-free survival rate in patients with recurrent HCC. Conclusion: SLT is the best treatment option when the recurrence of HCC meets Milan's criteria. RH and LA are the appropriate treatment plans for recurrent HCC when the liver source is limited.

[Influence factors of poor efficacy after flap repair operation in patients with pressure ulcers]

Objective: To investigate the influence factors of poor efficacy after flap repair operation in patients with pressure ulcers. Methods: The retrospective case series study was conducted. From January 2011 to June 2021, 125 patients with stage Ⅲ and Ⅳ pressure ulcers treated in Hainan General Hospital met the inclusion criteria. There were 82 males and 43 females, aged 15-90 (57±20) years. According to the postoperative effects, the patients were divided into poor efficacy group (47 cases) and good efficacy group (78 cases). The clinical data of patients in the two groups were collected, including the age, gender, location, stage, size, and bone exposure of pressure ulcers, preoperative microorganism culture results of wound exudate sample, whether combined with osteomyelitis, diabetes, lower limb paroxysmal myospasm, and gatism or not, the number of surgical debridement combined with negative-pressure wound therapy, type of surgical flap, postoperative position, and preoperative albumin, leukocyte, C-reactive protein (CRP), and hemoglobin. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The binary multivariate logistic regression analysis was conducted to screen the independent risk factors influencing the poor efficacy after flap repair operation in 125 patients with stage Ⅲ and Ⅳ pressure ulcers. Results: The ratio of patients with lower limb paroxysmal myospasm in poor efficacy group was 22/47, which was significantly higher than 3/78 in good efficacy group (χ2=33.83, P<0.01). The preoperative hemoglobin level of patients in poor efficacy group was (102±17) g/L, which was significantly lower than (113±20) g/L in good efficacy group (t=-3.24, P<0.01). The preoperative CRP level of patients was 39.1 (14.1, 91.6) mg/L in poor efficacy group, which was significantly higher than 15.3 (6.6, 42.0) mg/L in good efficacy group (Z=-3.04, P<0.01). There were no statistically significant differences in other indexes between patients in the two groups (P>0.05). Multivariate logistic regression analysis showed that age, lower limb paroxysmal myospasm, and preoperative hemoglobin level were the independent risk factors for poor efficacy after flap repair operation in patients with pressure ulcers (with odds ratios of 1.03, 40.69, and 0.97, 95% confidence intervals of 1.00-1.06, 9.18-180.39, and 0.95-1.00, respectively, P<0.05 or P<0.01). Conclusions: Poor efficacy after flap repair operation in patients with pressure ulcers is affected by many factors, among which the age, lower limb paroxysmal myospasm, and preoperative hemoglobin level are the independent risk factors.

Polarization and β-Glucan Reprogram Immunomodulatory Metabolism in Human Macrophages and Ex Vivo in Human Lung Cancer Tissues

Immunomodulatory (IM) metabolic reprogramming in macrophages (Mϕs) is fundamental to immune function. However, limited information is available for human Mϕs, particularly in response plasticity, which is critical to understanding the variable efficacy of immunotherapies in cancer patients. We carried out an in-depth analysis by combining multiplex stable isotope-resolved metabolomics with reversed phase protein array to map the dynamic changes of the IM metabolic network and key protein regulators in four human donors' Mϕs in response to differential polarization and M1 repolarizer β-glucan (whole glucan particles [WGPs]). These responses were compared with those of WGP-treated ex vivo organotypic tissue cultures (OTCs) of human non-small cell lung cancer. We found consistently enhanced tryptophan catabolism with blocked NAD+ and UTP synthesis in M1-type Mϕs (M1-Mϕs), which was associated with immune activation evidenced by increased release of IL-1β/CXCL10/IFN-γ/TNF-α and reduced phagocytosis. In M2a-Mϕs, WGP treatment of M2a-Mϕs robustly increased glucose utilization via the glycolysis/oxidative branch of the pentose phosphate pathway while enhancing UDP-N-acetyl-glucosamine turnover and glutamine-fueled gluconeogenesis, which was accompanied by the release of proinflammatory IL-1β/TNF-α to above M1-Mϕ's levels, anti-inflammatory IL-10 to above M2a-Mϕ's levels, and attenuated phagocytosis. These IM metabolic responses could underlie the opposing effects of WGP, i.e., reverting M2- to M1-type immune functions but also boosting anti-inflammation. Variable reprogrammed Krebs cycle and glutamine-fueled synthesis of UTP in WGP-treated OTCs of human non-small cell lung cancer were observed, reflecting variable M1 repolarization of tumor-associated Mϕs. This was supported by correlation with IL-1β/TNF-α release and compromised tumor status, making patient-derived OTCs unique models for studying variable immunotherapeutic efficacy in cancer patients.

NMR-based isotope editing, chemoselection and isotopomer distribution analysis in stable isotope resolved metabolomics

NMR is a very powerful tool for identifying and quantifying compounds within complex mixtures without the need for individual standards or chromatographic separation. Stable Isotope Resolved Metabolomics (or SIRM) is an approach to following the fate of individual atoms from precursors through metabolic transformation, producing an atom-resolved metabolic fate map. However, extracts of cells or tissue give rise to very complex NMR spectra. While multidimensional NMR experiments may partially overcome the spectral overlap problem, additional tools may be needed to determine site-specific isotopomer distributions. NMR is especially powerful by virtue of its isotope editing capabilities using NMR active nuclei such as 13C, 15N, 19F and 31P to select molecules containing just these atoms in a complex mixture, and provide direct information about which atoms are present in identified compounds and their relative abundances. The isotope-editing capability of NMR can also be employed to select for those compounds that have been selectively derivatized with an NMR-active stable isotope at particular functional groups, leading to considerable spectral simplification. Here we review isotope analysis by NMR, and methods of chemoselection both for spectral simplification, and for enhanced isotopomer analysis.

GAB functions as a bioenergetic and signalling gatekeeper to control T cell inflammation

γ-Aminobutyrate (GAB), the biochemical form of (GABA) γ-aminobutyric acid, participates in shaping physiological processes, including the immune response. How GAB metabolism is controlled to mediate such functions remains elusive. Here we show that GAB is one of the most abundant metabolites in CD4+ T helper 17 (TH17) and induced T regulatory (iTreg) cells. GAB functions as a bioenergetic and signalling gatekeeper by reciprocally controlling pro-inflammatory TH17 cell and anti-inflammatory iTreg cell differentiation through distinct mechanisms. 4-Aminobutyrate aminotransferase (ABAT) funnels GAB into the tricarboxylic acid (TCA) cycle to maximize carbon allocation in promoting TH17 cell differentiation. By contrast, the absence of ABAT activity in iTreg cells enables GAB to be exported to the extracellular environment where it acts as an autocrine signalling metabolite that promotes iTreg cell differentiation. Accordingly, ablation of ABAT activity in T cells protects against experimental autoimmune encephalomyelitis (EAE) progression. Conversely, ablation of GABAA receptor in T cells worsens EAE. Our results suggest that the cell-autonomous control of GAB on CD4+ T cells is bimodal and consists of the sequential action of two processes, ABAT-dependent mitochondrial anaplerosis and the receptor-dependent signalling response, both of which are required for T cell-mediated inflammation.

Resolving Enantiomers of 2-Hydroxy Acids by Nuclear Magnetic Resonance

Biologically important 2-hydroxy carboxylates such as lactate, malate, and 2-hydroxyglutarate exist in two enantiomeric forms that cannot be distinguished under achiral conditions. The D and L (or R, S) enantiomers have different biological origins and functions, and therefore, there is a need for a simple method for resolving, identifying, and quantifying these enantiomers. We have adapted and improved a chiral derivatization technique for nuclear magnetic resonance (NMR), which needs no chromatography for enantiomer resolution, with greater than 90% overall recovery. This method was developed for 2-hydroxyglutarate (2HG) to produce diastereomers resolvable by column chromatography. We have applied the method to lactate, malate, and 2HG. The limit of quantification was determined to be about 1 nmol for 2HG with coefficients of variation of less than 5%. We also demonstrated the method on an extract of a renal carcinoma bearing an isocitrate dehydrogenase-2 (IDH2) variant that produces copious quantities of 2HG and showed that it is the D enantiomer that was exclusively produced. We also demonstrated in the same experiment that the lactate produced in the same sample was the L enantiomer.

[Predictive value of blood cell parameters in the diagnosis of vasovagal syncope in children]

Objective: To investigate the predictive value of blood cell parameters in children with vasovagal syncope (VVS). Methods: In this case-control study, the VVS group included 111 patients with unexplained syncope or prodromata who were diagnosed with VVS by head-up tilt test in the Second Xiangya Hospital, Central South University from January 2018 to October 2020, and 111 healthy children were enrolled as control. The differences in blood cell parameters between the 2 groups were compared by t test and Mann-Whitney U test. Multivariate binary Logistic regression was used to analyze the independent correlation factors of VVS, and receiver operating characteristic (ROC) curve to explore the predictive value of blood cell parameters for diagnosing VVS. Results: Sex composition ratios were consistent in the 2 groups (51 males vs. 60 females), while the age of the VVS group was higher than that of the control group (11.0 (8.0, 12.5) vs. 8.0 (7.0, 11.0) years, Z=4.39, P<0.001). Compared with the control group, VVS group had lower level of white blood cell (WBC) (6.0 (5.3, 7.1)×10⁹ vs. 8.6 (6.7, 10.1)×10⁹/L, Z=-7.96, P<0.001), lymphocyte (LY) (2.3 (1.9, 2.7)×10⁹ vs. 4.0 (2.8, 6.3)×10⁹/L, Z=-8.49, P<0.001), lymphocyte ratio (0.39 (0.33, 0.44) vs. 0.52 (0.37, 0.69), Z=-5.59, P<0.001), monocyte (0.3 (0.3, 0.4)×10⁹ vs. 0.4 (0.3, 0.6)×10⁹/L, Z=-6.19, P<0.001), eosinophil (0.1 (0.1, 0.2)×10⁹ vs. 0.2 (0.2, 0.4)×10⁹/L, Z=-5.75, P<0.001), mean corpuscular-hemoglobin concentration (MCHC) ((328±12) vs. (333±11) g/L, t=-3.27, P<0.001) and blood platelet (263 (235, 313)×10⁹ vs. 341 (295, 409)×10⁹/L, Z=-2.69, P<0.001), but higher neutrophil ratio (0.53 (0.48, 0.58) vs. 0.37 (0.22, 0.54), Z=5.86, P<0.001), hematocrit (0.39±0.04 vs. 0.37±0.04, t=2.75, P=0.006), mean corpuscular volume (MCV) (85 (82, 88) vs. 81 (78, 84) fl, Z=5.56, P<0.001), mean corpuscular hemoglobin (28 (27, 29) vs. 27 (26, 28) pg, Z=3.39, P=0.001), red cell distribution width (39 (37, 41) vs. 37 (36, 40) fl, Z=4.02, P<0.001) and mean platelet volume (11 (10, 11) vs. 10 (9, 11) fl, Z=2.81, P=0.005) levels. After adjusting for confounding factors such as sex and age, LY (OR=0.42, 95%CI 0.29-0.62, P<0.001), WBC (OR=0.75, 95%CI 0.59-0.95, P=0.015), MCHC (OR=0.94, 95%CI 0.91-0.97, P<0.001) were independent negative correlation factors of VVS, while MCV (OR=1.08, 95%CI 1.01-1.15, P=0.021) was independent positive correlation factor. ROC curve showed that the combination of LY, WBC, MCV and MCHC had acceptable predictive value for the diagnosis of VVS, with area under curve of 0.88, sensitivity of 0.80, specificity of 0.83, and Youden index of 0.63. Conclusions: Compared with healthy children, the blood cell parameters usually change in those with VVS. Combination of LY, WBC, MCHC and MCV can facilitate the diagnosis of VVS in children with unexplained syncope or prodromata.