A real-world retrospective-prospective analysis of efficacy and safety of combined ixazomib, lenalidomide, and dexamethasone in relapsed/refractory multiple myeloma: The northern Italy experience.

INTRODUCTION: Ixazomib, lenalidomide, and dexamethasone (IRd) have been approved for the treatment of relapsed/refractory multiple myeloma (RRMM) based on the results of the TOURMALINE-MM1. OBJECTIVES AND METHODS: We conducted a retrospective-prospective analysis of 106 RRMM patients (pts) treated with IRd in 21 centers in Northern Italy, with the aim to evaluate the efficacy and safety of IRd in real life. RESULTS: At IRd initiation, 34% of pts were aged ≥75 (median 72.5), 8.5% had an ECOG performance status ≥2, 54.7% of evaluable pts carried high-risk cytogenetic abnormalities [del17p and/or t(4;14) and/or t(14;16) and/or 1 g gain/amp], 60.2% had received ≥2 prior lines of therapy (pLoT), 57.5% were lenalidomide (Len)-exposed (including both Len-sensitive and Len-refractory pts), and 22% were Len-refractory. Main G ≥3 adverse events (AEs) were thrombocytopenia (16%) and neutropenia (12.3%). G ≥3 non-hematologic AEs included infections (9.4%) and GI toxicity (diarrhea 5.7%, hepatotoxicity 2.8%), VTE, skin rash, and peripheral neuropathy were mainly G1-2. The overall response rate was 56.4% (≥VGPR 30%). With a median follow-up of 38 m, median PFS (mPFS) was 16 m and the 1-year OS rate was 73%. By subgroup analysis, an extended PFS was observed for pts achieving ≥VGPR (mPFS 21.2 m), time from diagnosis to IRd ≥5 years (26.2 m), 1 pLoT (34.4 m), Len-naïve (NR), age ≥70 (20 m). In pts exposed to Len, non-refractory in any prior line and immediately prior to IRd, mPFS was 16 and 18 m, respectively. An inferior PFS was seen in Len-refractory pts (4.6 m). By multivariate analysis, independent predictors of PFS were age ≥70 (HR 0.6), time from diagnosis ≥5 years (HR 0.32), refractoriness to Len in any prior line (HR 3.33), and immediately prior (HR 4.31). CONCLUSION: IRd might be effective and safe in RRMM pts with an indolent disease, in early lines of treatment, and who proved Len-sensitive, independent of age, and cytogenetic risk.

Acute Muscle Rigidity Secondary to Tetanus: A Toxicology Simulation Case for Fourth-Year Medical Students.

Introduction: Tetanus is uncommon in the United States secondary to vaccination. However, vaccination hesitancy is increasing. This case challenges medical students to consider tetanus in the differential and understand its complications. Methods: Fourth-year medical students took a pretest on the neurotransmitter glycine and associated disease states. They received two 10-minute lectures on glycine and acid-base abnormalities. Students then participated in a simulation featuring a 27-year-old man bitten by a dog, resulting in tetanus. Required equipment included a mannequin with monitor, a defibrillator, and personal protective equipment. Critical actions consisted of learners dividing up roles amongst each other, using closed-loop communication, placing the patient on a cardiac monitor, choosing to establish IV access and intubate the patient, starting IV fluids, and administering tetanus immunoglobulin. The case ended after 20 minutes. Outcome measurements encompassed performance on a posttest and critical actions. Results: Twenty students participated. Mean pretest and posttest scores were 69.5 and 92.5, respectively (p < .001). All groups completed the items on the critical actions checklist within a 20-minute time frame. Discussion: Rising vaccine hesitancy may increase the likelihood of physicians encountering new cases of tetanus and require them to perform lifesaving management of a patient presenting with muscle rigidity. This simulation provides learners with hands-on experience caring for a patient with tetanus and muscle rigidity. It can improve their knowledge of recognition, assessment, and decision-making toward lifesaving management of tetanus by allowing them to practice their skills in a safe environment.

Cryo-EM structure of the human Asc-1 transporter complex.

The Alanine-Serine-Cysteine transporter 1 (Asc-1 or SLC7A10) forms a crucial heterodimeric transporter complex with 4F2hc (SLC3A2) through a covalent disulfide bridge. This complex enables the sodium-independent transport of small neutral amino acids, including L-Alanine (L-Ala), Glycine (Gly), and D-Serine (D-Ser), within the central nervous system (CNS). D-Ser and Gly are two key endogenous glutamate co-agonists that activate N-methyl-d-aspartate (NMDA) receptors by binding to the allosteric site. Mice deficient in Asc-1 display severe symptoms such as tremors, ataxia, and seizures, leading to early postnatal death. Despite its physiological importance, the functional mechanism of the Asc-1-4F2hc complex has remained elusive. Here, we present cryo-electron microscopy (cryo-EM) structures of the human Asc-1-4F2hc complex in its apo state, D-Ser bound state, and L-Ala bound state, resolved at 3.6 Å, 3.5 Å, and 3.4 Å, respectively. Through detailed structural analysis and transport assays, we uncover a comprehensive alternating access mechanism that underlies conformational changes in the complex. In summary, our findings reveal the architecture of the Asc-1 and 4F2hc complex and provide valuable insights into substrate recognition and the functional cycle of this essential transporter complex.

The behavioral phenotype of children and adolescents with attenuated non-ketotic hyperglycinemia, intermediate to good subtype.

AIM: We aim to describe the behavioral phenotype of children and adolescents with the good to intermediate attenuated form of non-ketotic hyperglycinemia (NKH) and to explore associations between the behavioral phenotype and age, sex, plasma glycine levels and drug treatment. METHOD: Parents of children with attenuated NKH completed questionnaires assessing maladaptive behavior, adaptive behavior, social communication, speech/language development and motor development in addition to demographic and medical questions. RESULTS AND INTERPRETATION: Twelve children, age 6 to 21y, functioned at mild to severe intellectual disability levels. Their speech/language development was in line with their developmental quotient. Relative to their intellectual functioning, their motor development and communication were weaker in comparison to their general development. Their adaptive behavior, however, appeared a relative strength. There was no evidence for autism spectrum disorder occurring more frequently than expected, rather social skills, except for communication, were rated as a relative strength. Maladaptive behaviors with ADHD-like characteristics were present in more than two thirds of children. Maladaptive behaviors were significantly related to female sex and to taking dextromethorphan, but no significant relation between plasma glycine levels and behavior was found. Future studies will need to evaluate causality in the observed relation between dextromethorphan use and maladaptive behaviors. Clinicians should reconsider the benefit of dextromethorphan when presented with disruptive behaviors in children with attenuated NKH.

Pharmacokinetics of L-theanine and the effect on amino acid composition in mice administered with L-theanine.

L-theanine, an amino acid component of the tea leaves of Camellia sinensis, is sold in Japan as a supplement for good sleep. Although several studies in humans and mice have reported the effects of L-theanine on brain function, only a few reports have comprehensively clarified the disposition of theanine administered to mice and its effects on concentrations of other blood amino acids. In this study, we aimed to determine the changes in the blood levels of L-theanine administered to mice and amino acid composition of the serum. L-theanine were administered to four-week-old Std-ddY male mice orally or via tail vein injection. L-theanine and other amino acids in serum prepared from blood collected at different time points post-dose were labeled with phenylisothiocyanate and quantified. The serum concentration of orally administered L-theanine peaked 15 min after administration. The area under the curve for tail vein injection revealed the bioavailability of L- theanine to be approximately 70%. L-theanine administration did not affect any amino acid levels in the serum, but a significant increase in the peak area overlapping the Glycine (Gly) peak was observed 30 min after administration. L-theanine administered to mice was rapidly absorbed and eliminated, suggesting that taking L-theanine as a supplement is safe without affecting its own levels or serum levels of other amino acids. However, considering that Gly, similar to L-theanine, is used as a dietary supplement for its anxiolytic effects and to improve sleep, determining the effects of L-theanine administration on Gly is important and needs further research.

Heat flows enrich prebiotic building blocks and enhance their reactivity.

The emergence of biopolymer building blocks is a crucial step during the origins of life1-6. However, all known formation pathways rely on rare pure feedstocks and demand successive purification and mixing steps to suppress unwanted side reactions and enable high product yields. Here we show that heat flows through thin, crack-like geo-compartments could have provided a widely available yet selective mechanism that separates more than 50 prebiotically relevant building blocks from complex mixtures of amino acids, nucleobases, nucleotides, polyphosphates and 2-aminoazoles. Using measured thermophoretic properties7,8, we numerically model and experimentally prove the advantageous effect of geological networks of interconnected cracks9,10 that purify the previously mixed compounds, boosting their concentration ratios by up to three orders of magnitude. The importance for prebiotic chemistry is shown by the dimerization of glycine11,12, in which the selective purification of trimetaphosphate (TMP)13,14 increased reaction yields by five orders of magnitude. The observed effect is robust under various crack sizes, pH values, solvents and temperatures. Our results demonstrate how geologically driven non-equilibria could have explored highly parallelized reaction conditions to foster prebiotic chemistry.

Influence of Molecular Design on the Tumor Targeting and Biodistribution of PSMA-Binding Tracers Labeled with Technetium-99m.

Previously, we designed the EuK-based PSMA ligand BQ0413 with an maE3 chelator for labeling with technetium-99m. It showed efficient tumor targeting, but our preclinical data and preliminary clinical results indicated that the renal excretion levels need to be decreased. We hypothesized that this could be achieved by a decrease in the ligand's total negative charge, achieved by substituting negatively charged glutamate residues in the chelator with glycine. The purpose of this study was to evaluate the tumor targeting and biodistribution of two new PSMA inhibitors, BQ0411 and BQ0412, compared to BQ0413. Conjugates were radiolabeled with Tc-99m and characterized in vitro, using PC3-pip cells, and in vivo, using NMRI and PC3-pip tumor-bearing mice. [99mTc]Tc-BQ0411 and [99mTc]Tc-BQ0412 demonstrated PSMA-specific binding to PC3-pip cells with picomolar affinity. The biodistribution pattern for the new conjugates was characterized by rapid excretion. The tumor uptake for [99mTc]Tc-BQ0411 was 1.6-fold higher compared to [99mTc]Tc-BQ0412 and [99mTc]Tc-BQ0413. [99mTc]Tc-BQ0413 has demonstrated predominantly renal excretion, while the new conjugates underwent both renal and hepatobiliary excretion. In this study, we have demonstrated that in such small targeting ligands as PSMA-binding EuK-based pseudopeptides, the structural blocks that do not participate in binding could have a crucial role in tumor targeting and biodistribution. The presence of a glycine-based coupling linker in BQ0411 and BQ0413 seems to optimize biodistribution. In conclusion, the substitution of amino acids in the chelating sequence is a promising method to alter the biodistribution of [99mTc]Tc-labeled small-molecule PSMA inhibitors. Further improvement of the biodistribution properties of BQ0413 is needed.

Circulating metabolomic markers in association with overall burden of microvascular complications in type 1 diabetes.

INTRODUCTION: Diabetic retinopathy (DR), diabetic kidney disease (DKD) and distal symmetric polyneuropathy (DSPN) share common pathophysiology and pose an additive risk of early mortality. RESEARCH DESIGN AND METHODS: In adults with type 1 diabetes, 49 metabolites previously associated with either DR or DKD were assessed in relation to presence of DSPN. Metabolites overlapping in significance with presence of all three complications were assessed in relation to microvascular burden severity (additive number of complications-ie, presence of DKD±DR±DSPN) using linear regression models. Subsequently, the same metabolites were assessed with progression to endpoints: soft microvascular events (progression in albuminuria grade, ≥30% estimated glomerular filtration rate (eGFR) decline, or any progression in DR grade), hard microvascular events (progression to proliferative DR, chronic kidney failure, or ≥40% eGFR decline), and hard microvascular or macrovascular events (hard microvascular events, cardiovascular events (myocardial infarction, stroke, or arterial interventions), or cardiovascular mortality), using Cox models. All models were adjusted for sex, baseline age, diabetes duration, systolic blood pressure, HbA1c, body mass index, total cholesterol, smoking, and statin treatment. RESULTS: The full cohort investigated consisted of 487 participants. Mean (SD) follow-up was 4.8 (2.9, 5.7) years. Baseline biothesiometry was available in 202 participants, comprising the cross-sectional cohort. Eight metabolites were significantly associated with presence of DR, DKD, and DSPN, and six with additive microvascular burden severity. In the full cohort longitudinal analysis, higher levels of 3,4-dihydroxybutanoic acid (DHBA), 2,4-DHBA, ribonic acid, glycine, and ribitol were associated with development of events in both crude and adjusted models. Adding 3,4-DHBA, ribonic acid, and glycine to a traditional risk factor model improved the discrimination of hard microvascular events. CONCLUSIONS: While prospective studies directly assessing the predictive ability of these markers are needed, our results strengthen the role of clinical metabolomics in relation to risk assessment of diabetic complications in chronic type 1 diabetes.

How hydrophobicity, side chains, and salt affect the dimensions of disordered proteins.

Despite the generally accepted role of the hydrophobic effect as the driving force for folding, many intrinsically disordered proteins (IDPs), including those with hydrophobic content typical of foldable proteins, behave nearly as self-avoiding random walks (SARWs) under physiological conditions. Here, we tested how temperature and ionic conditions influence the dimensions of the N-terminal domain of pertactin (PNt), an IDP with an amino acid composition typical of folded proteins. While PNt contracts somewhat with temperature, it nevertheless remains expanded over 10-58°C, with a Flory exponent, ν, >0.50. Both low and high ionic strength also produce contraction in PNt, but this contraction is mitigated by reducing charge segregation. With 46% glycine and low hydrophobicity, the reduced form of snow flea anti-freeze protein (red-sfAFP) is unaffected by temperature and ionic strength and persists as a near-SARW, ν ~ 0.54, arguing that the thermal contraction of PNt is due to stronger interactions between hydrophobic side chains. Additionally, red-sfAFP is a proxy for the polypeptide backbone, which has been thought to collapse in water. Increasing the glycine segregation in red-sfAFP had minimal effect on ν. Water remained a good solvent even with 21 consecutive glycine residues (ν > 0.5), and red-sfAFP variants lacked stable backbone hydrogen bonds according to hydrogen exchange. Similarly, changing glycine segregation has little impact on ν in other glycine-rich proteins. These findings underscore the generality that many disordered states can be expanded and unstructured, and that the hydrophobic effect alone is insufficient to drive significant chain collapse for typical protein sequences.

Divergence in regulatory mechanisms of GR-RBP genes in different plants under abiotic stress.

The IVa subfamily of glycine-rich proteins (GRPs) comprises a group of glycine-rich RNA binding proteins referred to as GR-RBPa here. Previous studies have demonstrated functions of GR-RBPa proteins in regulating stress response in plants. However, the mechanisms responsible for the differential regulatory functions of GR-RBPa proteins in different plant species have not been fully elucidated. In this study, we identified and comprehensively studied a total of 34 GR-RBPa proteins from five plant species. Our analysis revealed that GR-RBPa proteins were further classified into two branches, with proteins in branch I being relatively more conserved than those in branch II. When subjected to identical stresses, these genes exhibited intensive and differential expression regulation in different plant species, corresponding to the enrichment of cis-acting regulatory elements involving in environmental and internal signaling in these genes. Unexpectedly, all GR-RBPa genes in branch I underwent intensive alternative splicing (AS) regulation, while almost all genes in branch II were only constitutively spliced, despite having more introns. This study highlights the complex and divergent regulations of a group of conserved RNA binding proteins in different plants when exposed to identical stress conditions. These species-specific regulations may have implications for stress responses and adaptations in different plant species.

The impact of obesity-associated glycine deficiency on the elimination of endogenous and exogenous metabolites via the glycine conjugation pathway.

Background: Glycine is an integral component of the human detoxification system as it reacts with potentially toxic exogenous and endogenously produced compounds and metabolites via the glycine conjugation pathway for urinary excretion. Because individuals with obesity have reduced glycine availability, this detoxification pathway may be compromised. However, it should be restored after bariatric surgery because of increased glycine production. Objective: To examine the impact of obesity-associated glycine deficiency on the glycine conjugation pathway. We hypothesize that the synthesis rates of acylglycines from endogenous and exogenous sources are significantly reduced in individuals with obesity but increase after bariatric surgery. Methods: We recruited 21 participants with class III obesity and 21 with healthy weight as controls. At baseline, [1,2-13C2] glycine was infused to study the glycine conjugation pathway by quantifying the synthesis rates of several acylglycines. The same measurements were repeated in participants with obesity six months after bariatric surgery. Data are presented as mean ± standard deviation, and p-value< 0.05 is considered statistically significant. Results: Baseline data of 20 participants with obesity were first compared to controls. Participants with obesity were significantly heavier than controls (mean BMI 40.5 ± 7.1 vs. 20.8 ± 2.1 kg/m2). They had significantly lower plasma glycine concentration (168 ± 30 vs. 209 ± 50 µmol/L) and slower absolute synthesis rates of acetylglycine, isobutyrylglycine, tigylglycine, isovalerylglycine, and hexanoylglycine. Pre- and post-surgery data were available for 16 participants with obesity. Post-surgery BMI decreased from 40.9 ± 7.3 to 31.6 ± 6.0 kg/m2. Plasma glycine concentration increased from 164 ± 26 to 212 ± 38 µmol/L) and was associated with significantly higher rates of excretion of acetylglycine, isobutyrylglycine, tigylglycine, isovalerylglycine, and hexanoylglycine. Benzoic acid (a xenobiotic dicarboxylic acid) is excreted as benzoylglycine; its synthesis rate was significantly slower in participants with obesity but increased after bariatric surgery. Conclusion: Obesity-associated glycine deficiency impairs the human body's ability to eliminate endogenous and exogenous metabolites/compounds via the glycine conjugation pathway. This impairment is ameliorated when glycine supply is restored after bariatric surgery. These findings imply that dietary glycine supplementation could treat obesity-associated metabolic complications due to the accumulation of intramitochondrial toxic metabolites. Clinical trial registration: https://clinicaltrials.gov/study/NCT04660513, identifier NCT04660513.

Guanidinoacetic acid ameliorates hepatic steatosis and inflammation and promotes white adipose tissue browning in middle-aged mice with high-fat-diet-induced obesity.

Guanidinoacetic acid (GAA) is a naturally occurring amino acid derivative that plays a critical role in energy metabolism. In recent years, a growing body of evidence has emerged supporting the importance of GAA in metabolic dysfunction. Hence, we aimed to investigate the effects of GAA on hepatic and adipose tissue metabolism, as well as systemic inflammatory responses in obese middle-aged mice models and attempted to explore the underlying mechanism. We found that dietary supplementation of GAA inhibited inguinal white adipose tissue (iWAT) hypertrophy in high-fat diet (HFD)-fed mice. In addition, GAA supplementation observably decreased the levels of some systemic inflammatory factors, including IL-4, TNF-α, IL-1ß, and IL-6. Intriguingly, GAA supplementation ameliorated hepatic steatosis and lipid deposition in HFD-fed mice, which was revealed by decreased levels of TG, TC, LDL-C, PPARγ, SREBP-1c, FASN, ACC, FABP1, and APOB and increased levels of HDL-C in the liver. Moreover, GAA supplementation increased the expression of browning markers and mitochondrial-related genes in the iWAT. Further investigation showed that dietary GAA promoted the browning of the iWAT via activating the AMPK/Sirt1 signaling pathway and might be associated with futile creatine cycling in obese mice. These results indicate that GAA has the potential to be used as an effective ingredient in dietary interventions and thus may play an important role in ameliorating and preventing HFD-induced obesity and related metabolic diseases.

Preparation and Evaluation of Chitosan Coated PLGA Nanoparticles Encapsulating Ivosidenib with Enhanced Cytotoxicity Against Human Liver Cancer Cells.

Purpose: Ivosidenib (IVO), an isocitrate dehydrogenase-1 (IDH1) used for treatment of acute myeloid leukemia (AML) and cholangiocarcinoma. However, poor solubility, low bioavailability, high dose and side effects limit clinical application of IVO. Methods: Ivosidenib-loaded PLGA nanoparticles (IVO-PLGA-NPs) and Ivosidenib-loaded chitosan coated PLGA nanoparticles (IVO-CS-PLGA-NPs) were prepared using emulsification and solvent evaporation method for the treatment of liver cancer. Results: The developed IVO-PLGA-NPs were evaluated for their particle size (171.7±4.9 nm), PDI (0.333), ZP (-23.0±5.8 mV), EE (96.3±4.3%), and DL (9.66±1.1%); similarly, the IVO-CS-PLGA-NPs were evaluated for their particle size (177.3±5.2 nm), PDI (0.311), ZP +25.9±5.7 mV, EE (90.8±5.7%), and DL (9.42±0.7%). The chitosan coating of IVO-PLGA-NPs was evidenced by an increase in mean particle size and positive ZP value. Because of the chitosan coating, the IVO-CS-PLGA-NPs showed a more stable and prolonged release of IVO than IVO-PLGA-NPs. In comparison to pure-IVO, the IVO-PLGA-NPs and IVO-CS-PLGA-NPs were found to be more effective against HepG2 cells, with IC50 values for the MTT assay being approximately half of those of pure-IVO. In HepG2 cells, the expressions of caspase-3, caspase-9, and p53 were significantly (p < 0.05) elevated. Conclusion: Overall, these findings suggest that chitosan coating of IVO-PLGA-NPs improves the delivery and efficacy of ivosidenib in liver cancer treatment.

Functions and Metabolism of Amino Acids in the Hair and Skin of Dogs and Cats.

The hair and skin of domestic cats or dogs account for 2% and 12-24% of their body weight, respectively, depending on breed and age. These connective tissues contain protein as the major constituent and provide the first line of defense against external pathogens and toxins. Maintenance of the skin and hair in smooth and elastic states requires special nutritional support, particularly an adequate provision of amino acids (AAs). Keratin (rich in cysteine, serine and glycine) is the major protein both in the epidermis of the skin and in the hair. Filaggrin [rich in some AAs (e.g., serine, glutamate, glutamine, glycine, arginine, and histidine)] is another physiologically important protein in the epidermis of the skin. Collagen and elastin (rich in glycine and proline plus 4-hydroxyproline) are the predominant proteins in the dermis and hypodermis of the skin. Taurine and 4-hydroxyproline are abundant free AAs in the skin of dogs and cats, and 4-hydroxyproline is also an abundant free AA in their hair. The epidermis of the skin synthesizes melanin (the pigment in the skin and hair) from tyrosine and produces trans-urocanate from histidine. Qualitative requirements for proteinogenic AAs are similar between cats and dogs but not identical. Both animal species require the same AAs to nourish the hair and skin but the amounts differ. Other factors (e.g., breeds, coat color, and age) may affect the requirements of cats or dogs for nutrients. The development of a healthy coat, especially a black coat, as well as healthy skin critically depends on AAs [particularly arginine, glycine, histidine, proline, 4-hydroxyproline, and serine, sulfur AAs (methionine, cysteine, and taurine), phenylalanine, and tyrosine] and creatine. Although there are a myriad of studies on AA nutrition in cats and dogs, there is still much to learn about how each AA affects the growth, development and maintenance of the hair and skin. Animal-sourced foodstuffs (e.g., feather meal and poultry by-product meal) are excellent sources of the AAs that are crucial to maintain the normal structure and health of the skin and hair in dogs and cats.

Roles of Nutrients in the Brain Development, Cognitive Function, and Mood of Dogs and Cats.

The brain is the central commander of all physical activities and the expression of emotions in animals. Its development and cognitive health critically depend on the neural network that consists of neurons, glial cells (namely, non-neuronal cells), and neurotransmitters (communicators between neurons). The latter include proteinogenic amino acids (e.g., L-glutamate, L-aspartate, and glycine) and their metabolites [e.g., γ-aminobutyrate, D-aspartate, D-serine, nitric oxide, carbon monoxide, hydrogen sulfide, and monoamines (e.g., dopamine, norepinephrine, epinephrine, and serotonin)]. In addition, some non-neurotransmitter metabolites of amino acids, such as taurine, creatine, and carnosine, also play important roles in brain development, cognitive health, behavior, and mood of dogs and cats. Much evidence shows that cats require dietary ω3 (α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid) and ω6 (linoleic acid and arachidonic acid) polyunsaturated fatty acids for the development of the central nervous system. As an essential component of membranes of neurons and glial cells, cholesterol is also crucial for cognitive development and function. In addition, vitamins and minerals are required for the metabolism of AAs, lipids, and glucose in the nervous system, and also act as antioxidants. Thus, inadequate nutrition will lead to mood disorders. Some amino acids (e.g., arginine, glycine, methionine, serine, taurine, tryptophan, and tyrosine) can help to alleviate behavioral and mood disorders (e.g., depression, anxiety and aggression). As abundant providers of all these functional amino acids and lipids, animal-sourced foods (e.g., liver, intestinal mucosa, and meat) play important roles in brain development, cognitive function, and mood of dogs and cats. This may explain, in part, why dogs and cats prefer to eat visceral organs of their prey. Adequate provision of nutrients in all phases of the life cycle (pregnancy, lactation, postnatal growth, and adulthood) is essential for optimizing neurological health, while preventing cognitive dysfunction and abnormal behavior.

[Clinical Efficacy and Safety of Ixazomib-Containing Regimens in the Treatment of Patients with Multiple Myeloma].

OBJECTIVE: To investigate the clinical efficacy and safety of ixazomib-containing regimens in the treatment of patients with multiple myeloma (MM). METHODS: A retrospective analysis was performed on the clinical efficacy and adverse reactions of 32 MM patients treated with a combined regimen containing ixazomib in the Hematology Department of the First People's Hospital of Lianyungang from January 2020 to February 2022. Among the 32 patients, 15 patients were relapsed and refractory multiple myeloma (R/RMM) (R/RMM group), 17 patients who responded to bortezomib induction therapy but converted to ixazomib-containing regimen due to adverse events (AE) or other reasons (conversion treatment group). The treatment included IPD regimen (ixazomib+pomalidomide+dexamethasone), IRD regimen (ixazomib+lenalidomide+dexamethasone), ICD regimen (ixazomib+cyclophosphamide+dexamethasone), ID regimen (ixazomib+dexamethasone). RESULTS: Of 15 R/RMM patients, overall response rate (ORR) was 53.3%(8/15), among them, 1 achieved complete response (CR), 2 achieved very good partial response (VGPR) and 5 achieved partial response (PR). The ORR of the IPD, IRD, ICD and ID regimen group were 100%（3/3）, 42.9%（3/7）, 33.3%（1/3）, 50%（1/2）， respectively， there was no statistically significant difference in ORR between four groups (χ 2=3.375, P =0.452). The ORR of patients was 50% after first-line therapy, 42.9% after second line therapy, 60% after third line therapy or more, with no statistically significant difference among them (χ2=2.164, P =0.730). In conversion treatment group, ORR was 88.2%(15/17), among them, 6 patients achieved CR, 5 patients achieved VGPR and 4 patients achieved PR. There was no statistically significant difference in ORR between the IPD（100%， 3/3）, IRD（100%， 6/6）, ICD（100%， 3/3） and ID（60%， 3/5） regimen groups (χ2=3.737，P =0.184). The median progression-free survival (PFS) time of R/RMM patients was 9 months (95% CI : 6.6-11.4 months), the median overall survival (OS) time was 18 months (95% CI : 11.8-24.4 months). The median PFS time of conversion treatment group was 15 months (95% CI : 7.3-22.7 months), the median OS time not reached. A total of 10 patients suffered grade 3- 4 adverse event (AE). The common hematological toxicities were leukocytopenia, anemia, thrombocytopenia. The common non-hematological toxicities were gastrointestinal symptoms (diarrhea, nausea and vomit), peripheral neuropathy, fatigue and infections. Grade 1-2 peripheral neurotoxicity occurred in 7 patients. CONCLUSION: The ixazomib-based chemotherapy regimens are safe and effective in R/RMM therapy, particularly for conversion patients who are effective for bortezomib therapy. The AE was manageable and safe.

A molecular dynamics simulation study of glycine/serine octapeptides labeled with 2,3-diazabicyclo[2.2.2]oct-2-ene fluorophore.

The compound 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) is a versatile fluorophore widely used in Förster resonance energy transfer (FRET) spectroscopy studies due to its remarkable sensitivity, enabling precise donor-acceptor distance measurements, even for short peptides. Integrating time-resolved and FRET spectroscopies with molecular dynamics simulations provides a robust approach to unravel the structure and dynamics of biopolymers in a solution. This study investigates the structural behavior of three octapeptide variants: Trp-(Gly-Ser)3-Dbo, Trp-(GlyGly)3-Dbo, and Trp-(SerSer)3-Dbo, where Dbo represents the DBO-containing modified aspartic acid, using molecular dynamics simulations. Glycine- and serine-rich amino acid fragments, common in flexible protein regions, play essential roles in functional properties. Results show excellent agreement between end-to-end distances, orientational factors from simulations, and the available experimental and theoretical data, validating the reliability of the GROMOS force field model. The end-to-end distribution, modeled using three Gaussian distributions, reveals a complex shape, confirmed by cluster analysis highlighting a limited number of significant conformations dominating the peptide landscape. All peptides predominantly adopt a disordered state in the solvent, yet exhibit a compact shape, aligning with the model of disordered polypeptide chains in poor solvents. Conformations show marginal dependence on chain composition, with Ser-only chains exhibiting slightly more elongation. This study enhances our understanding of peptide behavior, providing valuable insights into their structural dynamics in solution.

Structure and function of GluN1-3A NMDA receptor excitatory glycine receptor channel.

N-methyl-d-aspartate receptors (NMDARs) and other ionotropic glutamate receptors (iGluRs) mediate most of the excitatory signaling in the mammalian brains in response to the neurotransmitter glutamate. Uniquely, NMDARs composed of GluN1 and GluN3 are activated exclusively by glycine, the neurotransmitter conventionally mediating inhibitory signaling when it binds to pentameric glycine receptors. The GluN1-3 NMDARs are vital for regulating neuronal excitability, circuit function, and specific behaviors, yet our understanding of their functional mechanism at the molecular level has remained limited. Here, we present cryo-electron microscopy structures of GluN1-3A NMDARs bound to an antagonist, CNQX, and an agonist, glycine. The structures show a 1-3-1-3 subunit heterotetrameric arrangement and an unprecedented pattern of GluN3A subunit orientation shift between the glycine-bound and CNQX-bound structures. Site-directed disruption of the unique subunit interface in the glycine-bound structure mitigated desensitization. Our study provides a foundation for understanding the distinct structural dynamics of GluN3 that are linked to the unique function of GluN1-3 NMDARs.

Novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and aggressive presentation.

Childhood melanoma is a rare and biologically heterogeneous pediatric malignancy. The differential diagnosis of pediatric melanoma is usually broad, including a wide variety of spindle cell or epithelioid neoplasms. Different molecular alterations affecting the MAPK and PI3K/AKT/mTOR pathways, tumor suppressor genes, and telomerase reactivation have been implicated in melanoma tumorigenesis and progression. Here, we report a novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and an aggressive clinical course.