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Protein sparing therapies were developed to mitigate the harms associated with protein-calorie malnutrition and nitrogen losses induced by either acute illness or hypocaloric diets in patients with obesity. We review the development of protein sparing therapies in illness and obesity with a focus on the pioneering contributions of George Blackburn, MD, PhD. He recognized that protein-calorie malnutrition is a common and serious clinical condition and developed new approaches to its treatment in hospitalized patients. His work with stable isotopes and with animal models provided answers about the physiological nutritional requirements and metabolic changes across a spectrum of conditions with varying degrees of stress and catabolism. This led to improvements in enteral and parenteral nutrition for patients with acute illness. Blackburn also demonstrated that lean body mass can be preserved during weight loss with carefully designed very low calorie treatments which became known as the protein sparing modified fast (PSMF). We review the role of the PSMF as part of the comprehensive management of obesity. [ABSTRACT FROM AUTHOR]

Background Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) are used in the diagnosis and monitoring of plasma cell dyscrasias. IFE is considered the most sensitive method for the detection of monoclonal proteins (M-proteins), but it is not quantitative. The goal of this study was to establish the analytical sensitivity and diagnostic performance of SPE on the Sebia Hydrasys using HYDRAGEL 30 PROTEIN(E) β1-β2. Methodology Patient sera with a previously identified M-protein (IgG, IgA or IgM) were serially diluted with a normal serum pool and electrophoresed on the Sebia Hydrasys using HYDRAGEL 30 PROTEIN(E) β1-β2. The SPE gels were individually interpreted by five independent observers and IFE was performed on selected samples. Limit of detection was determined as the lowest concentration of M-protein band visible on the gel. SPE diagnostic performance was evaluated against the “gold standard” IFE according CLSI EP12-A2 guidelines. Results Detection limit was comparable among all M-proteins migrating in the gamma region, IgG-κ (0.18 ± 0.08 g/L; n = 6), IgG-λ (0.36 ± 0.25 g/L; n = 8), IgA-κ (0.40 ± 0.13 g/L; n = 7), IgA-λ (0.37 ± 0.23 g/L; n = 4), IgM-κ (0.47 ± 0.20 g/L; n = 13) and IgM-λ (0.29 ± 0.24 g/L; n = 6). Percentage agreement with IFE for IgG and IgA in the gamma region ranged from 65% to 100%, whereas IgM migrating in the gamma region and immunoglobulins co-migrating with alpha or beta globulins, showed poor (0–38%) agreement. Conclusions This study evaluates the analytical sensitivity and diagnostic performance of SPE on the Sebia Hydrasys using HYDRAGEL 30 PROTEIN(E) β1-β2. There was acceptable agreement between SPE and IFE for IgG-κ/λ and IgA-κ/λ migrating in the gamma region, suggesting that repeating IFE for samples with these isotypes, when the previous IFE and second SPE are both negative, may not be necessary. [ABSTRACT FROM AUTHOR]

Interactions between macrophages and adipocytes influence both metabolism and inflammation. Obesity-induced changes to macrophages and adipocytes lead to chronic inflammation and insulin resistance. This paper reviews the various functions of macrophages in lean and obese adipose tissue and how obesity alters adipose tissue macrophage phenotypes. Metabolic disease and insulin resistance shift the balance between numerous pro- and anti-inflammatory regulators of macrophages and create a feed-forward loop of increasing inflammatory macrophage activation and worsening adipocyte dysfunction. This ultimately leads to adipose tissue fibrosis and diabetes. The molecular mechanisms underlying these processes have therapeutic implications for obesity, metabolic syndrome, and diabetes. [ABSTRACT FROM AUTHOR]

Single-cell RNA-sequencing (scRNA-seq) was utilized to investigate the intratumoral heterogeneity of primary, recurrent, and metastatic osteosarcoma (OS) lesions. Briefly, following biopsy or surgical resection (1), tumor specimens are digested into a single-cell suspension (2) before encapsulation into emulsion droplets for scRNA-seq library construction using the 10X Genomics Chromium Controller. Libraries are evaluated for quality before sequencing (4). Standard pipelines and tools such as Cell Ranger are then used for pre-processing, integration, and cellular clustering before downstream expression analysis (5) [Figure designed at BioRender.com]. [Display omitted] • scRNA-seq has provided invaluable insight into the heterogeneity of various tumors. • Review highlights scRNA-seq on OS primary, recurrent, or metastatic lesions. • Possible target identification and association with recurrent, metastatic potential. • TIGIT expression across immune cell populations suggests exhaustion in OS TME. While primary bone malignancies make up just 0.2% of all cancers, osteosarcoma (OS) is the third most common cancer in adolescents. Due to its highly complex and heterogeneous tumor microenvironment (TME), OS has proven difficult to treat. There has been little to no improvement in therapy for this disease over the last 40 years. Even the recent success of immunotherapies in other blood-borne and solid malignancies has not translated to OS. With frequent recurrence and lung metastases continuing to pose a challenge in the clinic, recent advancements in molecular profiling, such as single-cell RNA sequencing (scRNA-seq), have proven useful in identifying novel biomarkers of OS tumors while providing new insight into this TME that could potentially lead to new therapeutic options. This review combines the analyses of over 150,000 cells from 18 lesions ranging from primary, recurrent, and metastatic OS lesions, revealing distinct cellular populations and gene signatures that exist between them. Here, we detail these previous findings and ultimately convey the intratumoral heterogeneity that exists within OS tumor specimens. [ABSTRACT FROM AUTHOR]

Background The CALIPER program has established a comprehensive database of age- and sex-stratified pediatric reference intervals for over 85 common biochemical markers, largely using the Abbott ARCHITECT assays. To allow a broader application of the CALIPER database, we examined transference to 36 Beckman Coulter Synchron Unicel DxC800 assays, based on the CLSI C28-A3/EP9-A3 guidelines. Methods Patient sample comparisons were performed for 36 biochemical assays using 200 serum specimens obtained from pediatric patients on the Abbott ARCHITECT ci8200 and the Beckman Coulter DxC800. For each analyte, R 2 values were calculated to assess the quality of correlation between the platforms. Statistical criteria used to assess transferability included a) regression analysis to create the equation of the line of best fit, b) standardized residual, c) Bland–Altman, and d) quantile–quantile plots. Transferred reference intervals were further verified by analyzing serum samples from 100 healthy children from the CALIPER cohort on the Beckman Coulter system. Results The reference intervals for most of the assessed analytes were transferable to Beckman Coulter assays (31 out of 36 studied) and the newly calculated reference intervals were verified through analysis of CALIPER reference samples (28 out of 31). Eighteen assays demonstrated excellent correlation (R 2 ≥ 0.95), and 13 assays showed strong correlation (0.77 ≤ R2 ≤ 0.94). Conclusion The current study allowed successful transference of a large number of biochemical markers from the CALIPER database to assays on the Beckman Coulter DxC800 platform. Transference should facilitate broader application of CALIPER reference intervals at pediatric centers using DxC biochemical assays. [ABSTRACT FROM AUTHOR]

• Clinical tools and diagnostic signs and symptoms remain adequate at diagnosing NAS. • There is a significant gap in knowledge whether drug testing results are being used to confirm the diagnosis of NAS. • Each matrix (meconium, umbilical cord, and urine) has its own unique advantages and limitations. • There is a lack of standardization in the cut-off value and analyte profiles. • The goal of neonatal drug testing is to support the diagnosis of NAS, provide the appropriate follow-up and treatment for the mother-neonate dyad, not to identify maternal substance use disorder. Illicit drug use during pregnancy is a concern worldwide, with many international studies describing attempted strategies to mitigate this problem. Drug misuse during pregnancy is associated with significant maternal as well as perinatal complications, which include a high incidence of stillbirths, fetal distress, neonatal abstinence syndrome (NAS) and increased neonatal mortality. Unfortunately, the identification of a drug-exposed mother or neonate is challenging. Maternal disclosure of drug use is often inaccurate, principally due to psychosocial factors including behavioral denial or the fear of the consequences resulting from such admissions. Likewise, many infants who have been exposed to drugs in utero may appear normal at birth and initially show no overt manifestations of drug effects. Thus, the identification of the drug-exposed infant requires a high index of clinical suspicion. Conversely, analytical testing is an objective means of determining drug exposure when it may be necessary to document proof of the infant's exposure to illicit drugs. The review will discuss the different matrices that are most commonly used for testing (e.g., maternal urine, neonatal urine, meconium, and umbilical cord), the strengths and limitations for each matrix, which drugs and metabolites are appropriate for testing, the various testing methods, and the advantages and disadvantages of each method. [ABSTRACT FROM AUTHOR]

Posterior percutaneous fixation (PPF) can be challenging, particularly in patients with advanced deformity, osteoporosis or prior surgeries. Sacrum S1 pedicle screws breach or misplacement can be related to the anatomic variability of the entry points and the lack of corresponding reliable radiographic landmarks. A reliable intraoperative radiographic description of the S1 pedicle entry point is, therefore, necessary for a safe and reproducible PPF. This study highlights a reproducible anatomical sacral landmark ("V" sign) for the safe localization of the S1 pedicle entry point under fluoroscopy. An anatomic cadaveric study and a retrospective review of patients who had S1 screws placed percutaneously using intraoperative radiographic "V" landmark. Human cadavers (N=14) were dissected for the anatomic description of the "V" landmark. The CT scans of 135 consecutive adult patients were evaluated for the accuracy of S1 pedicle screws percutaneously placed under fluoroscopy and "V" sign guidance. Mean distance between the bottom point of the "V" landmark and the anatomic entry point to the S1 pedicle was measured on all cadavers. Accuracy of percutaneously placed S1 screws using the "V" sign in patients who underwent PPF. Human cadavers were dissected for the anatomic description of the "V" landmark, and its relationship with the anatomic entry point of the S1 pedicle. The spatial "V" landmark was defined medially by the lateral border of the superior facet of S1 and laterally by the posterior projection of the sacral ala. The mean distance between the bottom point of the "V" landmark and the anatomic entry point to the S1 pedicle was measured on all cadavers. Subsequently, a review of CT scans of patients who underwent minimally invasive antepsoas surgery (MIS-ATP) and PPF using the "V" sign as a landmark for S1 pedicle screw placement. Postoperative CT scan S1 screws breaches were collected and graded. In 14 cadavers, the average distance between the bottom point of the "V" landmark and the anatomical entry of the S1 pedicles was 12.0 mm on the left and 11.3 mm on the right. In the medial-lateral axis, all the entry points were within a zone defined +/- 2 mm from the vertical line dropped from the base of the "V". There were no significant differences in this measurement with respect to laterality and sex. Additionally, a retrospective review of 135 patients who underwent percutaneous S1 pedicle screw placement using the "V" landmark showed 8.5% breaches. These were graded as B (5.2%), C (2.2%), D (0.7%), and E (0.4%). Identifying the anatomical entry point to the S1 pedicles under radiographic imaging is crucial for safe MIS surgery. The "V" sign serves as a reliable anatomic and radiographic landmark, situated 12 mm proximal to and on the same vertical line of the anatomical entry of S1 pedicles. This landmark helps the MIS surgeons overcome the radiographic ambiguity of the sacral anatomy, and ultimately mitigates improper S1 pedicle screws placement. S1 Pedicle screws (Approved for this indication) [ABSTRACT FROM AUTHOR]

Abstract: Background: The importance of describing, understanding and regulating multi-pollutant mixtures has been highlighted by the US National Academy of Science and the Environmental Protection Agency. Furthering our understanding of the health effects associated with exposure to mixtures of pollutants will lead to the development of new multi-pollutant National Air Quality Standards. Objectives: Introduce a framework within which diagnostic methods that are based on our understanding of air pollution mixtures are used to validate the distinct air pollutant mixtures identified using cluster analysis. Methods: Six years of daily gaseous and particulate air pollution data collected in Boston, MA were classified solely on their concentration profiles. Classification was performed using k-means partitioning and hierarchical clustering. Diagnostic strategies were developed to identify the most optimal clustering. Results: The optimal solution used k-means analysis and contained five distinct groups of days. Pollutant concentrations and elemental ratios were computed in order to characterize the differences between clusters. Time-series regression confirmed that the groups differed in their chemical compositions. The mean values of meteorological parameters were estimated for each group and air mass origin between clusters was examined using back-trajectory analysis. This allowed us to link the distinct physico-chemical characteristics of each cluster to characteristic weather patterns and show that different clusters were associated with distinct air mass origins. Conclusions: This analysis yielded a solution that was robust to outlier points and interpretable based on chemical, physical and meteorological characteristics. This novel method provides an exciting tool with which to identify and further investigate multi-pollutant mixtures and link them directly to health effects studies. [Copyright &y& Elsevier]

Abstract: Protein arginine methylation is one of the epigenetic modifications to proteins that is studied in yeast and is known to be involved in a number of human diseases. All eukaryotes produce Nη-monomethylarginine (ηMMA), asymmetric Nη1, Nη1-dimethylarginine (aDMA), and most produce symmetric Nη1, Nη2-dimethylarginine (sDMA) on proteins, but only yeast produce Nδ-monomethylarginine (δMMA). It has proven difficult to differentiate among all of these methylarginines using mass spectrometry. Accordingly, we demonstrated that the two forms of MMA have indistinguishable primary product ion spectra. However, the secondary product ion spectra of δMMA and ηMMA exhibited distinct patterns of ions. Using incorporation of deuterated methyl-groups in yeast, we determined which secondary product ions were methylated and their structures. Utilizing distinct secondary product ions, a triple quadrupole multiple reaction monitoring cubed (MRM3) assay was developed to measure δMMA, ηMMA, sDMA and aDMA derived from hydrolyzed protein. As a proof-of-concept, δMMA and ηMMA were measured using the MRM3 method in wild type and mutant strains of Saccharomyces cerevisiae and compared to the total MMA measured using an existing assay. The MRM3 assay represents the only method to directly quantify δMMA and the only method to simultaneously quantify all yeast methylarginines. [Copyright &y& Elsevier]