Residual Activity Research Articles

Developing Strategies to Mitigate Squash Injury from the Soil Residual Activity of Glyphosate in Bareground Systems

Fresh market vegetables are an essential component of the human diet. Maximizing yield is critical, and to achieve this goal, fields must be weed-free when vegetable crops are planted. Historically, removing emerged weeds just before planting has been accomplished using the herbicide glyphosate. However, recent research has indicated that glyphosate applied to sandy, low-organic-matter soils just before transplanting vegetables can be injurious. Two field experiments investigated 1) the response of transplanted squash to the residual activity of glyphosate, and 2) the effects of implementing tillage, irrigation, or extending the plant-back interval after application and before planting to mitigate injury from glyphosate. Glyphosate applied at 1.3, 2.5, or 3.8 kg ae/ha 1 day before transplanting injured squash 13%, 29%, and 53%, respectively; extending the interval between application and planting to 7 days reduced injury to 1%, 11%, and 28% at the same rates. An interaction between application rate and planting interval was also observed on squash plant widths and biomass, as well as early-season and total marketable fruit numbers and weights. Total marketable fruit number was reduced 29% and 52% by glyphosate at 2.5 or 3.8 kg ae/ha, respectively, and a reduction in fruit production of 36%, 28%, and 23% was observed when glyphosate was applied 1, 4, or 7 days before transplanting, respectively. In a separate study, light tillage (5 cm deep) was the most effective cultural practice evaluated because it eliminated damage by glyphosate. Overhead irrigation of 0.6 cm was not beneficial in mitigating injury by glyphosate. Recommendations from this research will help vegetable growers avoid injury from the residual activity of glyphosate through a FIFRA 2(ee) recommendation label.

EXPRESS: The lexical boost is not an automatic part of sentence production: Evidence from Japanese structural priming.

The lexical boost is an increase in structural priming with overlapping elements like verbs. Residual activation priming theories argue that the boost is an automatic side effect of sentence planning. In contrast, explicit memory theories of the boost argue that it is the result of a non-automatic explicit memory retrieval. These theories were contrasted in Japanese by including a prime memory task in a structural priming study. Structural priming was found for both datives and passives, but no lexical boost was found and one possible reason was that explicit memory for the prime structure was weak. In a follow-up study, priming was found in a sentence completion task, but there was no lexical boost. The existence of abstract priming and the lack of a lexical boost in these studies falsifies theories that argue that verb overlap automatically creates a boost under conditions that exhibit abstract priming.

Photo‐and Electrochemical Modification of Amino Acids, Peptides and Proteins through Cysteine: Recent Advances and Future Perspectives

AbstractChemical modification of peptides and proteins has emerged as an efficient strategy to study and manipulate the physical and chemical properties and biological functionalities of proteins. Among the 20 proteinogenic amino acids, cysteine is one of the most frequently targeted residues for chemical modification of peptides and proteins due to its unique thiol group and its relatively low natural abundance. Cysteine is able to partake in radical and atom‐, electron‐ and hydride‐transfer reactions taking the benefit of redox activity of thiol side chain. Recently, photo‐ and electrochemistry have emerged as influential methodologies for enabling novel transformations in organic synthesis. These two fields both involve the generation of radical intermediates through single electron transfer processes, which align well with the redox activity of cysteine residue. Furthermore, the mild and controllable features are suitable for solving the chemo‐ and regioselective problems of the existing bioconjugation strategies. Given the intrinsic benefits of photo‐ and electrochemical redox catalysis, the application of developing novel cysteine‐based bioconjugation methods is increasingly compelling. This review provides a comprehensive overview of recent advancements in photo‐ and electrochemical approaches for modifying cysteine amino acid residues, cysteine‐containing peptides, and proteins. The advantages of photo‐ and electrochemical redox catalysis and its applicability in developing novel biocompatible methods are discussed. Additionally, the current limitations of these methods and the challenges that need to be addressed in the future are also explored.

The Residual Activity of Fatty Acyl-CoA Reductase Underlies Thermo-Sensitive Genic Male Sterility in Rice.

Photoperiod/thermo-sensitive genic male sterility (P/TGMS) is critical for rice two-line hybrid system. Previous studies showed that slow development of pollen is a general mechanism for sterility-to-fertility conversion of TGMS in Arabidopsis. However, whether this mechanism still exists in rice is unknown. Here, we identified a novel rice TGMS line, ostms16, which exhibits abnormal pollen exine under high temperature and fertility restoration under low temperature. In mutant, a single base mutation of OsTMS16, a fatty acyl-CoA reductase (FAR), reduced its enzyme activity, leading to defective pollen wall. Under high temperature, the mOsTMS16M549I couldn't provide sufficient protection for the microspores. Under low temperature, the enzyme activity of mOsTMS16M549I is closer to that of OsTMS16, so that the imperfect exine could still protect microspore development. These results indicated whether the residual enzyme activity in mutant could meet the requirement in different temperature is a determinant factor for fertility conversion of P/TGMS lines. Additionally, we previously found that res2, the mutant of a polygalacturonase for tetrad pectin wall degradation, restored multiple TGMS lines in Arabidopsis. In this study, we proved that the osres2 in rice restored the fertility of ostms16, indicating the slow development is also suitable for the fertility restoration in rice.

Recessive Variants in PIGG Cause a Motor Neuropathy with Variable Conduction Block, Childhood Tremor, and Febrile Seizures: Expanding the Phenotype.

Biallelic variants in phosphatidylinositol glycan anchor biosynthesis, class G (PIGG) cause hypotonia, intellectual disability, seizures, and cerebellar features. We present 8 patients from 6 families with a childhood-onset motor neuropathy and neurophysiology demonstrating variable motor conduction block and temporal dispersion. All individuals had a childhood onset tremor, 5 of 8 had cerebellar involvement, and 6 of 8 had childhood febrile seizures. All individuals have biallelic PIGG variants, including the previously reported pathogenic variant Trp505*, plus 6 novel variants. Null enzyme activity is demonstrated via PIGO/PIGG double knockout system for Val339Gly and Gly19Glu, and residual activity for Trp505* due to read-through. Emm negative blood group status was confirmed in 1 family. PIGG should be considered in unsolved motor neuropathy. ANN NEUROL 2024.

Clinical impact of TP53 functional mutations in patients with metastatic colorectal cancer treated with bevacizumab and chemotherapy.

Clinical and experimental studies indicate that the tumor protein p53 (TP53) gene loss of function due to missense mutations (MMs) may confer sensitivity to anti-angiogenics. This effect seems to be linked to cross-talk mechanisms among TP53, vascular endothelial growth factor (VEGF), and VEGF receptors. We investigated whether specific TP53 MMs are associated with clinical outcomes of patients with metastatic colorectal cancer (mCRC) treated with first-line chemotherapy plus Bevacizumab. The study focused on KRAS-mutated, liver-only mCRC cases as a homogeneous subgroup that may represent a relevant setting for exploring this association. MMs were identified on primary tumors. MMs were classified by mutant-specific residual transcriptional activity scores (TP53RTAS) as transcriptionally inactive (TP53inactive = TP53RTAS 0%) or active (TP53active = TP53RTAS ≥ 1%) and used for stratifying patients in progression-free survival (PFS), response rate, and overall survival (OS) analyses. The study population consisted of 62 patients. MMs were found in 39 cases (62%) with 16 having TP53inactive and 23 TP53active MMs. Patients with TP53inactive MMs showed better PFS in comparison with the remaining groups (wild-type and TP53active). This effect was retained in the multivariate model. A similar clinical impact was observed in the OS analysis. There was a significant difference in the overall response rate and rate of post-treatment resection of liver metastases between the TP53inactive and the wild-type or TP53active MMs cases. Specific TP53 MMs may identify sub-groups of patients who benefit from Bevacizumab-based systemic therapy and these findings could lead to novel tailored treatment strategies in this setting.

Cutting-Edge Technology Without Cutting: Treating Skin Cancer in This Era—A Case Series

Background: Traditional treatment methods for non-melanoma skin cancer (NMSC) include surgical excision with histological evaluation, yet advancements such as reflectance confocal microscopy (RCM) and superficial radiation therapy (SRT) offer non-invasive management alternatives. This study aims to evaluate the use of RCM for the evaluation of treatment outcomes after SRT in managing localized NMSC. Methods: A prospective interventional case series study was conducted on patients treated for NMSC with SRT between March 2020 and December 2023. Suspected NMSC lesions were initially evaluated with a handheld dermoscope and then imaged at multiple depths using a VivaScope 1500 RCM. Two dermatologists trained in RCM reviewed the images. Confirmed NMSC lesions were biopsied and treated with SRT, followed by RCM imaging at six months post-treatment to assess cancer clearance, scarring, and inflammation. Results: Of the 38 lesions (composed of SCC (24) and BCC (14)) treated affecting the 29 patients, all lesions showed no residual tumor activity upon conducting follow-up RCM (100% clearance). Scarring and mild erythema were noted clinically. Six lesions demonstrated moderate to severe inflammation at a 6-month follow-up. Conclusions: This study demonstrates successful non-invasive management of localized NMSC using RCM and SRT. RCM was able to non-invasively demonstrate complete tumor clearance achieved by SRT with minimal adverse effects. These findings support considering the use of RCM and SRT as primary diagnostic, monitoring, and treatment options for NMSC without the need for biopsies, especially for elderly patients or those unsuitable for surgery due to medical conditions.

Cold-adapted characteristics and gene knockout of alkyl hydroperoxide reductase subunit C in Antarctic Psychrobacter sp. ANT206.

Alkyl hydroperoxide reductase subunit C (AhpC) contributes to the cellular defense against reactive oxygen species. However, it remains understudied in psychrophiles. Amino acid comparison demonstrated that AhpC from Psychrobacter sp. ANT206 (ANT206) (PsAhpC) revealed fewer numbers of Lys and more numbers of Gly, which might have favored higher flexibility at low temperature. The recombinant PsAhpC (rPsAhpC) was most active at 25°C and retained 35% of its residual activity at 0°C, indicating that it was a cold-adapted enzyme. Additionally, rPsAhpC demonstrated significant salt tolerance, sustaining its activity in the presence of 4.0M NaCl. Molecular dynamics simulations indicated that PsAhpC had comparatively loose conformation, which facilitated reactions at low temperatures. Subsequently, an ahpc knockout mutant was constructed, and the growth rate of the knockout mutant significantly decreased, suggesting that ahpc might be crucial for the growth of ANT206 at low temperatures. The findings provide a robust foundation for further investigation into the structural features and catalytic characterization of cold-adapted AhpC. The structural characteristics of PsAhpC and its cold tolerance and salt tolerance may be applied to stress resistance breeding of various organisms.

Expression study of Krabbe Disease GALC missense variants - Insights from quantification profiles of residual enzyme activity, secretion and psychosine levels.

Krabbe disease (KD) is an autosomal recessive lysosomal storage disorder caused by loss-of-function mutations in the GALC gene, which encodes for the enzyme galactosylceramidase (GALC). GALC is crucial for myelin metabolism. Functional deficiency of GALC leads to toxic accumulation of psychosine, dysfunction and death of oligodendrocytes, and eventual brain demyelination. To date, 46 clinically-relevant, pathogenic GALC missense mutations (MMs) have been identified in KD patients. These MMs are present in ∼70% of KD cases reported over 8 published studies between 1996 - 2019. However, the mechanisms by which these MMs lead to GALC functional deficiency and their correlations with clinical phenotype remain poorly understood. To address this, we generated a GALC -knockout human oligodendrocytic cell line (MO3.13/ GALC -KO) using CRISPR-Cas9 method to assess GALC function and GALC secretion. We evaluated 5 polymorphic and 31 clinically-relevant MM variants (MMVs) using transient expression assays. Our results showed that 26 MMVs, including 10 co-variants with p.I562T, reduced GALC activity by 92% - 100% compared to wild-type GALC (WT-GALC). MMVs from infantile-onset KD patients produced < 2% of WT activity, whereas those associated with juvenile- and adult-onset cases retained up to 7% of WT activity. Residual GALC activity was correlated with mature, lysosomal GALC protein levels (Pearson r = 0.93, P<0.0001). Many low-activity MMVs did not correspondingly impair GALC secretion. Twenty-one of the 26 low-activity MMVs showed a 21% - 100% reduction in sec-GALC levels, indicating varying degrees of GALC mis-trafficking among these variants. Importantly, GALC activity among MMVs strongly correlates with clinical disease severity, based on the age of symptom onset in patients with either homozygous MM (Pearson r = 0.98, P<0.0001, n = 7) or compound heterozygous (Pearson r = 0.94, P<0.0001, n = 12) MM-null mutation genotypes. Thus, our data suggests that GALC activity could serve as a prognostic disease indicator under specific experimental conditions. We further investigated the impact of pathogenic MMVs on psychosine accumulation, a key biomarker for KD. Psychosine levels were 21-fold higher in mock control cells compared to WT-GALC transfected cells (mock = 0.349 pmol/mg, WT-GALC = 0.016 pmol/mg), but negatively correlated with GALC activity among pathogenic MMVs (Pearson r = -0.63, P < 0.01, n = 15). Although psychosine levels were higher in most MMVs associated with infantile-onset KD, no significant correlations with clinical onset were detected. Overall, our study provides a comprehensive quantitative analysis of the functional deficits and mis-trafficking associated with clinically-relevant GALC MMVs, enhancing our understanding of the molecular genetics and genotype-phenotype correlations of the GALC gene in Krabbe disease.

SUPREM: an engineered non-site-specific m6A RNA methyltransferase with highly improved efficiency.

N 6-Methyladenine(m6A) RNA methylation plays a key role in RNA processing and translational regulation, influencing both normal physiological and pathological processes. Yet, current techniques for studying RNA methylation struggle to isolate the effects of individual m6A modifications. Engineering of RNA methyltransferases (RNA MTases) could enable development of improved synthetic biology tools to manipulate RNA methylation, but it is challenging due to limited understanding of structure-function relationships in RNA MTases. Herein, using ancestral sequence reconstruction, we explore the sequence space of the bacterial DNA methyltransferase EcoGII (M.EcoGII), a promising target for protein engineering due to its lack of sequence specificity and its residual activity on RNA. We thereby created an efficient non-specific RNA MTase termed SUPer RNA EcoGII Methyltransferase (SUPREM), which exhibits 8-fold higher expression levels, 7°C higher thermostability and 12-fold greater m6A RNA methylation activity compared with M.EcoGII. Immunofluorescent staining and quantitativeliquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis confirmed SUPREM's higher RNA methylation activity compared with M.EcoGII in mammalian cells. Additionally, Nanopore direct RNA sequencing highlighted that SUPREM is capable of methylating a larger number of RNA methylation sites than M.EcoGII. Through phylogenetic and mutational analysis, we identified a critical residue for the enhanced RNA methylation activity of SUPREM. Collectively, our findings indicate that SUPREM holds promise as a versatile tool for in vivo RNA methylation and labeling.

Characteristic study of Candida rugosa lipase immobilized on lignocellulosic wastes: effect of support material.

For the first time is reported the comparison of solid biocatalysts derived from Candida rugosa lipase (CRL) immobilized on different lignocellulosic wastes (rice husk, brewer's spent grain, hemp tea waste, green tea waste, vine bark, and spent coffee grounds) focusing on the characterization of these materials and their impact on the lipase-support interaction. The wastes were subjected to meticulous characterization by ATR-FTIR, BET, and SEM analysis, besides lignin content and hydrophobicity determination. Investigating parameters influencing immobilization performance revealed the importance of morphology, textural properties, and hydrophobic interactions revealed the importance of morphology, textural properties and especially hydrophobic interactions which resulted in positive correlations between surface hydrophobicity and lipase immobilization efficiency. Hemp tea waste and spent coffee grounds demonstrated superior immobilization performances (7.20 U/g and 8.74 U/g immobilized activity, 102.3% and 33.5% efficiency, 13.4% and 15.4% recovery, respectively). Moreover, they demonstrated good temporal stability (100% and 92% residual activity after 120days, respectively) and retained 100% of their immobilized activity after five reuses in the hydrolysis of p-nitrophenyl palmitate in hexane. In addition, the study of enzymatic desorption caused by ionic strength and detergent treatments indicated mixed hydrophobic and electrostatic interactions in rice husk, vine bark, and spent coffee grounds supports, while hemp tea waste and green tea waste were dominated by hydrophobic interactions.

Assessment of Gastric Remnant Activity, Symptoms, and Quality of Life Following Gastric Bypass.

While most gastric bypass patients recover well, some experience long-term complications, including nausea, abdominal pain, food intolerance, and dumping. This study aimed to evaluate symptoms and quality of life (QoL) in association with the residual activity of the remnant stomach. Patients undergoing gastric bypass and conversion-to-bypass were recruited. The Gastric Alimetry® System (Auckland, NZ) was employed, comprising a high-resolution electrode array, wearable reader, and validated symptom logging app. The protocol comprised 30-min fasting baseline, a 218-kCal meal stimulus, and 4-h of post-prandial recordings. Symptoms and QoL were evaluated using validated questionnaires. Remnant gastric electrophysiology evaluation included frequency, BMI-adjusted amplitude, and Gastric Alimetry Rhythm Index (GA-RI, reflecting pacemaker stability), with comparison to validated reference intervals and matched controls. Thirty-eight participants were recruited with mean time from bypass 46.8 ± 28.6months. One-third of patients showed moderate to severe post-prandial symptoms, with patients' median PAGI-SYM 28 ± 19 vs controls 9 ± 17 (p < 0.01); PAGI-QOL 37 ± 31 vs 135 ± 22 (p < 0.0001). Remnant gastric function was markedly degraded shown by undetectable frequencies in 84% (vs 0% in controls) and low GA-RI (0.18 ± 0.08 vs 0.51 ± 0.22 in controls; p < 0.0001; reference range > 0.25). Impaired GA-RI and amplitude were correlated with worse PAGI-SYM and PAGI-QOL scores. One-third of post-bypass patients suffered significant upper GI symptoms with reduced QoL. The bypassed remnant stomach shows highly deranged electrophysiology in-situ, reflecting disuse degeneration. These derangements correlated with QoL; however, causality is not implied by the present study.

Chitinase and Deacetylase-Based Chitin-Degrading Bacteria: One-Pot Cascade Bioconversion of Chitin to Chitooligosaccharides.

Cascade conversion of chitin into soluble and functional chitooligosaccharides has gained great attention. However, the biotransformation route is still limited to the low catalytic performances of chitin deacetylases (CDAs) and complicated procedures. In this study, a CDA from Arthrobacter sp. Jub115 (ArCDA) was identified and characterized, which showed a higher catalytic stability than the reported CDAs, with residual activity of 80.49%, 71.12%, and 56.09% after incubation at 30, 35, and 40 °C for 24 h, respectively. Additionally, ArCDA was identified to have a broad substrate spectrum toward β-chitin and N-acetyl chitooligosaccharides. Moreover, an engineered chitin-degrading bacteria (CDB) with cell-surface-displayed deacetylase ArCDA and chitinase SaChiB was constructed to simplify catalysis procedures, facilitating the chitobiose production of 294.30 ± 16.43 mg/L in 10 h. This study not only identified a CDA with the desirable catalytic performance but also provided a strategy for constructing CDB, facilitating the high-value utilization of chitin.

Characterizing and optimizing glutamate decarboxylase from Priestia flexa for efficient biosynthesis of γ-aminobutyric acid from l-glutamic acid powder

Gamma-aminobutyric acid (GABA) is widely applied in the food and pharmaceutical industries, and is experiencing a continually growing market demand. Nevertheless, the efficient and stable production of GABA confronts challenges, especially the instability of its core enzyme, glutamate decarboxylase (GAD). GAD exhibits high activity under acidic conditions but very poor stability. This limitation severely restricts its application in large-scale industrial production. In this study, we identified and characterized a GAD from Priestia flexa (PfGAD) with high activity. We further developed a variant with significantly enhanced acidic st ability. The specific activity of the variant achieved 139.8 U/mg, and its residual activity remained approximately 90 % after overnight incubation in pH 3.0 buffer. Moreover, we engineered a strain by overexpressing a transporter protein for GABA and l-glutamic acid, while deleting the pepD gene. The yield of GABA led to 251.8 g L−1, accompanied by a conversation rate of 97.8 %, meanwhile the cell growth maintained normal. Our approach successfully addresses the challenge of balancing cell growth and GABA accumulation. Our findings offer valuable insights into acid resistance modification of the enzyme, and optimizing GABA production through strain modification, holding significant potential for the industrial application of GABA.

The antibacterial activity of a novel highly thermostable endolysin, LysKP213, against Gram-negative pathogens is enhanced when combined with outer membrane permeabilizing agents.

Phages and phage-encoded lytic enzymes are promising antimicrobial agents. In this study, we report the isolation and identification of bacteriophage KP2025 from Klebsiella pneumoniae. Bioinformatics analysis of KP2025 revealed a putative endolysin, LysKP213, containing a T4-like_lys domain. Purified LysKP213 was found to be highly thermostable, retaining approximately 44.4% of its lytic activity after 20 h of incubation at 95°C, and approximately 57.5% residual activity after 30 min at 121°C. Furthermore, when administered in combination with polymyxin B or fused at the N-terminus with the antimicrobial peptide cecropin A (CecA), LysKP213 exhibited increased antibacterial activity against Gram-negative pathogens, including K. pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli, both in vitro and in vivo. These results indicated that LysKP213 is a highly thermostable endolysin that, when combined with or fused with an outer membrane permeabilizer, has enhanced antibacterial activity and is a candidate agent for the control of infections by Gram-negative pathogens.

Shelf life and storage stability of cold plasma treated kiwifruit juice: kinetic models

ABSTRACT This study examined the quality changes and shelf life of cold plasma (Cold plasma-optimized, S2: 30 kV/5 mm/6.7 min and Cold plasma-extreme, S3: 30 kV/2 mm/10 min) and thermally-treated (S4: 90°C/5 min) kiwifruit juice packed in glass and polyethylene terephthalate bottles stored at 5, 15, and 25°C. Cold plasma and thermally treated juice samples were analyzed for peroxidase activity, microbial enumeration, bioactive compounds degradation, and sensory quality for up to 120 days. The residual activity of peroxidase enzyme in S2 sample after cold plasma treatment was 23.85%, decreasing with increase in storage time and temperature. After cold plasma and thermal treatment, the aerobic mesophiles and yeasts and molds count were below detectable limits in kiwifruit juice. Aerobic mesophiles and yeasts & molds emerged in S2, S3, and S4 samples stored at 5°C after 70, 70, and 90 days, respectively. The total color change increased with increase in storage time and temperature, whereas ascorbic acid, total phenolic content, total antioxidant capacity, and overall acceptability decreased. The shelf life of S2 in glass bottles was 100, 80, and 60 days at 5, 15, and 25°C based on total color change ≥ 12, ascorbic acid loss ≥ 50%, microbial count ≥ 6 Log CFU/mL, or overall acceptability < 5. Quality indices, including total color change, overall sensory acceptability, and ascorbic acid, were modeled, and zero-order model performed better than first and second-order reaction models. Furthermore, Arrhenius, Eyring, and Ball models were employed to model temperature-dependent reaction rates, and the Ball model performed better. So, the zero-order reaction and Ball model were combined to predict kiwifruit juice’s shelf life.

Experience in Using 99mTc-Technephyt Esophageal Transit Scintigraphy for Assessing Pneumatic Dilation Outcome in Patients with Achalasia Cardia

Objective: to show the possibility of using 99mTc-technephyt esophageal transit scintigraphy (ETS) to assess the effect of cardiodilation in patients with achalasia cardia.Material and methods. We examined 7 patients (6 males and 1 female) aged 44–73 years (mean age 57.8 years) diagnosed with achalasia cardia, who were treated in Department of Thoracic Surgery No. 2 at Republican Clinical Hospital from June 2022 to January 2023. The disease duration before admission to the hospital ranged from 2 to 17 years (mean 9.2 years).Results. The analysis of ETS results showed a decreased radiopharmaceutical residual activity percentage in cardia for all patients after treatment compared with the initial data. It indicated a positive effect of cardiodilation and coincided with X-ray examination data. The obtained results demonstrate the possibility of ETS using and its practical significance to assess the effect of therapeutic measures, in particular cardiodilation, in patients with achalasia cardia.Conclusion. Performed according to the described protocol, ETS is a physiological and safe method for both the diagnosis of achalasia and the subsequent assessing therapeutic effect, including cardiodilation, myotomy, conservative treatment, and long-term dynamic monitoring. It is a physiological and safe procedure, which can be recommended in cases of difficulties in evaluating the esophageal function by X-ray, endoscopic and manometric methods or when their use is impossibile.

Elevating anthocyanin extraction from mangosteen pericarp: A comparative exploration of conventional and emerging non-thermal technology

Mangosteen pericarp (MP) is abundant in bioactive compounds but is often discarded as waste, leading to environmental pollution. This study compared the extraction of dried MP using maceration and high-pressure processing (HPP). HPP at 10 min (500 MPa/20 °C) resulted in the highest ACNs, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities. It also significantly reduced residual enzyme activities (REA) of polyphenol oxidase (PPO) and peroxidase (POD) by 33.90 % and 8.27 %, respectively. Fourier-transform infrared spectroscopy (FT-IR) analysis revealed a new wavelength at 2665.25 cm−1, and scanning electron microscopy (SEM) showed significant pore formation in MP cells, indicating cell damage. HPP-10 min enhanced the extraction of bioactive compounds, which significantly elevated the thermal stability of ACNs at 60 °C. This suggests that HPP is a promising method for extracting and preserving ACNs and other bioactive compounds from dried MP, with potential applications as natural colorants.

6850 A Case of Anaplastic Thyroid Carcinoma With a Complete Metabolic Response to Pembrolizumab

Abstract Disclosure: E. Tirthani: None. J.T. Kung: None. Background: Anaplastic thyroid carcinoma (ATC) is an aggressive disease with limited therapeutic options and generally poor prognosis. Post-surgery, most patients are treated with a combination of chemotherapy, radiation, and tyrosine kinase inhibitors +/- immune checkpoint inhibitors. We describe a unique case of ATC with a complete metabolic response to pembrolizumab, a selective PD-1 inhibitor, as evidenced by imaging. Clinical Case: A 69-year-old female presented to the clinic for evaluation of a rapidly enlarging neck mass. The initial ultrasound showed a large mixed cystic-solid right thyroid nodule with irregular margins with micro- and macrocalcifications, which was biopsied. Cytology showed discohesive high-grade malignant tumor cells with enlarged nuclei, nuclear hyperchromasia in the background of necrosis, and dense neutrophilic infiltration concerning for ATC. A CT scan of the neck and chest showed a complex cystic thyroid mass with central necrosis and calcification with paratracheal, supraclavicular, and mediastinal lymphadenopathy. MRI of the brain was negative for metastatic disease. The patient underwent a total thyroidectomy with right and left level 6 and 7 neck dissection. Intra-operatively, gross extrathyroidal extension of the tumor was noted to the right carotid, larynx, right recurrent laryngeal nerve, and esophagus, with residual tumor left behind near the larynx. Pathology confirmed stage IVC ATC, positive for PIK3CA, NF1, p53 mutations, and BRAF negative. 90% of tumor cells showed PD-L1 expression on immunohistochemical staining. The post-surgical PET scan showed two discrete, well-defined foci of very intense FDG uptake, corresponding to the right lower cervical and para-esophageal lymph nodes with no evidence of distant metastasis. Systemic chemotherapy with carboplatin and paclitaxel (5 cycles) was initiated with concurrent intensity modulated radiation therapy (total 60 Gy/40 fractions to thyroid bed and bilateral neck). Repeat imaging showed minimal change in the size of the PET-positive lymph nodes. Immunotherapy was initiated and with just 2 cycles of 400 mg IV pembrolizumab, a repeat PET scan was obtained, which showed a complete metabolic response to therapy. Minimal residual FDG activity in the right supraclavicular region was thought to be secondary to posttreatment changes. The patient was able to resume her activities of daily living and had an improvement in appetite. The plan is to continue 400 mg IV pembrolizumab every 6 weeks while cautiously assessing for adverse effects from immunotherapy. Conclusion: It is rare to see a complete metabolic response to therapy with pembrolizumab without concurrent use of tyrosine kinase inhibitors in patients with ATC. A high tumoral PD-L1 expression may be the key to having this kind of dramatic response. Presentation: 6/3/2024

Periodic Paralysis in a Child With Thermosensitive Mitochondrial Trifunctional Protein Deficiency.

Mitochondrial trifunctional protein (MTP) deficiency is a fatty acid oxidation disorder associated with a spectrum of phenotypes. Patients with high residual enzyme activity tend to have milder phenotypes, and recently, fever-induced episodic myopathy was reported in association with a thermosensitive form of MTP deficiency. We report a 10-year-old male with recurrent episodes of acute flaccid paralysis involving upper and lower extremities in association with bulbar muscle weakness in the context of febrile illness, a phenotype reminiscent of recurrent periodic paralysis. The episodes started at the age of 3 years and have always been followed by full recovery within 1-2 weeks with no residual weakness. Whole exome sequencing revealed a homozygous c.2132C > T, p.(Pro711Leu) variant in HADHA. The variant leads to mildly reduced long-chain hydroxyacyl-CoA dehydrogenase (LCHAD) and long-chain ketoacyl-CoA thiolase (LCKAT) enzyme activities and reduced MTP protein expression in patient's fibroblasts when cultured at 37°C. Enzyme activities and MTP protein expression diminished when fibroblasts were cultured at 40°C. This is the first published report of confirmed recurrent periodic paralysis as a manifestation of a thermosensitive form of MTP deficiency, and it calls for this condition to be considered when evaluating patients with recurrent periodic paralysis given therapeutic implications.