Comparison of Immediate Intensive Care Outcomes of Patent Ductus Arteriosus Stenting Versus Modified Blalock-Taussig-Thomas Shunt in Infants With Ductal-Dependent Pulmonary Circulation.

Patent Ductus Arteriosus (PDA) stenting is an alternative to Modified Blalock-Taussig-Thomas Shunt (BT) to increase pulmonary blood flow in ductal-dependent pulmonary circulation. The objective of this study is to compare the immediate Intensive Care Unit (ICU) outcomes of PDA stent versus BT shunt in infants with ductal-dependent pulmonary circulation. This is a single center, retrospective study in infants less than 6 months with ductal-dependent pulmonary circulation palliated with either PDA stenting or BT shunt from January 2015 till December 2023. Data were reviewed from pediatric ICU database. Demographics details, ICU parameters, mortality and morbidity were compared. The propensity score with inverse probability weighting was used to control the effect of covariates. A total of 302 patients with PDA stenting and 100 patients with BT shunt were included. Majority of the patients had intervention at first month of life. 126 (41.7%) patient underwent PDA stenting while 36 (36%) had BTS. The PDA stenting group has shorter ICU stay, 3 (2.0,6.0) days versus 8 (4.8,13.0) days (p < 0.001), shorter length of hospital stay, 9 (6.8,15.0) days versus 16 (11.0,22.0) days (p < 0.001), shorter ventilation days, 2 (1.0,4.0) days versus 3 (2.0,7.0) days (p < 0.001) and lower mortality, 7 (2.3%) versus 16 (16.0%) (p < 0.001). At 3 months follow-up, the survival was higher in the PDA stenting group (p < 0.001). Conclusion: PDA stenting in infants with ductal-dependent pulmonary blood flow has a more favorable intensive care outcomes with shorter ICU and hospital stay. PDA stenting has a better survival outcome.

Anorectal malformation and Hirschsprung's disease: a cross-sectional multicentre comparison of quality of life and bowel function to a healthy population.

PURPOSE: Children with anorectal malformation (ARM) and Hirschsprung's disease (HD) often experience bowel symptoms into adulthood, despite definitive surgery. This study evaluates the quality of life (QOL) and bowel functional outcome of children treated for ARM and HD in comparison to healthy controls. METHODS: Between December 2020 and February 2023, we recruited patients with ARM and HD aged 3-17 years at four tertiary referral centres, who had primary corrective surgery done >12 months prior. Healthy controls were age-matched and sex-matched. All participants completed the Pediatric Quality of Life Inventory Generic Core Scales 4.0, General Well-Being (GWB) Scale 3.0 and Family Impact (FI) Module 2.0 Questionnaires. Bowel Function Score (BFS) Questionnaires were also administered. We also performed subgroup analysis according to age categories. Appropriate statistical analysis was performed with p<0.05 significance. Ethical approval was obtained. RESULTS: There were 306 participants: 101 ARM, 87 HD, 118 controls. Patients with ARM and HD had significantly worse Core and FI Scores compared with controls overall and in all age categories. In the GWB Scale, only ARM and HD adolescents (13-17 years) had worse scores than controls. ARM and HD had significantly worse BFSs compared with controls overall and in all age categories. There was significant positive correlation between BFS and Core Scores, GWB Scores and FI Scores. CONCLUSION: Patients with ARM and HD had worse QOL than controls. Lower GWB Scores in adolescents suggests targeted interventions are necessary. Bowel function influences QOL, indicating the need for continuous support into adulthood.

Predictors on outcomes of cardiovascular disease of male patients in Malaysia using Bayesian network analysis.

OBJECTIVES: Despite extensive advances in medical and surgical treatment, cardiovascular disease (CVD) remains the leading cause of mortality worldwide. Identifying the significant predictors will help clinicians with the prognosis of the disease and patient management. This study aims to identify and interpret the dependence structure between the predictors and health outcomes of ST-elevation myocardial infarction (STEMI) male patients in Malaysian setting. DESIGN: Retrospective study. SETTING: Malaysian National Cardiovascular Disease Database-Acute Coronary Syndrome (NCVD-ACS) registry years 2006-2013, which consists of 18 hospitals across the country. PARTICIPANTS: 7180 male patients diagnosed with STEMI from the NCVD-ACS registry. PRIMARY AND SECONDARY OUTCOME MEASURES: A graphical model based on the Bayesian network (BN) approach has been considered. A bootstrap resampling approach was integrated into the structural learning algorithm to estimate probabilistic relations between the studied features that have the strongest influence and support. RESULTS: The relationships between 16 features in the domain of CVD were visualised. From the bootstrap resampling approach, out of 250, only 25 arcs are significant (strength value ≥0.85 and the direction value ≥0.50). Age group, Killip class and renal disease were classified as the key predictors in the BN model for male patients as they were the most influential variables directly connected to the outcome, which is the patient status. Widespread probabilistic associations between the key predictors and the remaining variables were observed in the network structure. High likelihood values are observed for patient status variable stated alive (93.8%), Killip class I on presentation (66.8%), patient younger than 65 (81.1%), smoker patient (77.2%) and ethnic Malay (59.2%). The BN model has been shown to have good predictive performance. CONCLUSIONS: The data visualisation analysis can be a powerful tool to understand the relationships between the CVD prognostic variables and can be useful to clinicians.

Resurgence of Dengue Virus Serotype 4 in Malaysia: A Comprehensive Clinicodemographic and Genomic Analysis.

Dengue virus serotype 4 (DENV-4) has been the rarest circulating serotype in Malaysia, resulting in it being an understudied area. A recent observation from institutional surveillance data indicated a rapid increase in DENV-4-infected cases. The present study aimed to investigate the resurgence of DENV-4 in relation to the demographic, clinical and genomic profiles of 75 retrospective dengue samples. First, the demographic and clinical profiles obtained between 2017 and July 2022 were statistically assessed. Samples with good quality were subjected to full genome sequencing on the Illumina Next Seq 500 platform and the genome data were analysed for the presence of mutations. The effect of the mutations of interest was studied via an in silico computational approach using SWISS-MODEL and AlphaFold2 programs. The predominance of DENV-4 was discovered from 2021 to 2022, with a prevalence of 64.3% (n = 9/14) and 89.2% (n = 33/37), respectively. Two clades with a genetic divergence of 2.8% were observed within the dominant genotype IIa. The majority of DENV-4-infected patients presented with gastrointestinal symptoms, such as vomiting (46.7%), persistent diarrhoea (30.7%) and abdominal pain (13.3%). Two mutations, His50Tyr and Pro144Ser, located at the wing domain of the NS1 protein were discovered to be unique to the recently sequenced DENV-4.

Application of Multilocus Sequence Typing for the Characterization of Leptospira Strains in Malaysia.

Leptospirosis is a common zoonotic disease in tropical and subtropical countries. It is considered an emerging disease in Malaysia and is a notifiable disease. This study was conducted to characterize Malaysian isolates from human, animal and environmental samples via MLST and rrs2 sequencing in an attempt to develop a Malaysian genotypic database. An existing polymerase chain reaction (PCR)-based MLST scheme was performed to facilitate subsequent sequencing. Out of 46 extracted DNA, 36 had complete MLST profiles whereby all six genes were amplified and sequenced. Most of the pathogenic Leptospira genotypes with full MLST profiles were L. interrogans serogroup Bataviae (n = 17), followed by L. borgpetersenii serogroup Javanica (n = 9), L. interrogans serogroup Sejroe (n = 2), L. interrogans serogroup Australis (n = 2), L. kirschneri (n = 2), L. interrogans serogroup Grippotyphosa (n = 1) and L. interrogans serogroup Pyrogenes (n = 3). Two samples (R3_SER/17 and R4_SER/17) were not closely related with any of the reference strains. For the samples with incomplete MLST profiles, leptospiral speciation was conducted through rrs2 analysis, in which four samples were identified as L. borgpetersenii, five samples were closely related to L. kmetyi and one sample was known as L. yasudae. This study shows that molecular approaches that combine both MLST and rrs2 sequencing have great potential in the comprehensive characterization of pathogenic Leptospira because they can be performed directly from cultured and clinical samples.

A rare case of mycotic pseudoaneurysm in a patient post Rastelli procedure with infective endocarditis.

Mycotic pseudoaneurysm secondary to infective endocarditis is an uncommon complication in CHD with conduit placement. We report a case of late presentation of bacterial infective endocarditis with pseudoaneurysm in an 8-year-old girl with underlying pulmonary atresia with ventricular septal defect, post Rastelli procedure done at the age of 3 years old.

RARE PRESENTATION OF BILATERAL CAROTID-CAVERNOUS FISTULA AS SUPRACHOROIDAL HEMORRHAGE DURING CATARACT SURGERY.

OBJECTIVE: To report a rare case of suprachoroidal hemorrhage during phacoemulsification in a patient with bilateral carotid-cavernous fistula. METHOD: Case report. RESULT: A 76-year-old woman with underlying hypertension presented left eye poor vision due to an underlying dense cataract. Her initial preoperative assessment was uneventful, and she underwent phacoemulsification. During epinucleus removal, there was sudden, unexpected anterior chamber shallowing, resulting in posterior capsule rupture. While the surgeon extended the wound to facilitate epinucleus removal, there was a further decrease of red reflex, followed by hardening of the globe, indicating a suprachoroidal hemorrhage. The corneal wound was opposed swiftly without an intraocular lens. Further evaluation after that revealed the patient had a chronic headache for several years, and ocular examination showed bilateral esophoria. A computed tomography demonstrated features suggestive of bilateral carotid-cavernous fistula, which was confirmed with computed tomography angiography later. CONCLUSION: Patients with carotid-cavernous fistula have elevated episcleral venous pressure and vortex venous pressure. Sudden decompression of the globe in these patients predisposes them to higher suprachoroidal hemorrhage risk, although this condition is generally rare in phacoemulsification.

The VEGAS Platform Is Unsuitable for Mammalian Directed Evolution.

Directed evolution uses cycles of gene diversification and selection to generate proteins with novel properties. While traditionally directed evolution is performed in prokaryotic systems, recently a mammalian directed evolution system (viral evolution of genetically actuating sequences, or "VEGAS") has been described. Here we report that the VEGAS system has major limitations that preclude its use for directed evolution. The deconstructed Sindbis virus (SINV) genome that comprises the VEGAS system could no longer promote Sindbis structural gene (SSG)-dependent viral replication. Moreover, viral particles generated using the VEGAS system rapidly lost the target directed evolution transgene, and instead, "cheater" particles, primarily containing RNA encoding SINV structural components, arose. By sequencing, we found that this contamination came from RNA provided during initial SINV packaging, not RNA derived from the VEGAS system. Of note, both the structural RNA and target transgenes used in the VEGAS system contain viral packaging sequences. The impact of SINV "cheater" particles could be potentially overcome in the context of a robust VEGAS circuit, but since SSG complementation is also defective in the VEGAS system, selection for authentic evolution products is not currently possible. Similar results have been obtained in independent laboratories. Taken together, these results show that the VEGAS system does not work as described and, without significant redesign, cannot be used for mammalian directed evolution campaigns.

Molecular, Biochemical, and Clinical Characterization of Thirteen Patients with Glycogen Storage Disease 1a in Malaysia.

Background: Glycogen storage disease type 1a (GSD1a) is a rare autosomal recessive metabolic disorder characterized by hypoglycaemia, growth retardation, lactic acidosis, hepatomegaly, hyperlipidemia, and nephromegaly. GSD1a is caused by a mutation in the G6PC gene encoding glucose-6-phosphatase (G6Pase); an enzyme that catalyses the hydrolysis of glucose-6-phosphate (G6P) to phosphate and glucose. Objective: To elaborate on the clinical findings, biochemical data, molecular genetic analysis, and short-term prognosis of 13 GSD1a patients in Malaysia. Methods: The information about 13 clinically classified GSD1a patients was retrospectively studied. The G6PC mutation analysis was performed by PCR-DNA sequencing. Results: Patients were presented with hepatomegaly (92%), hypoglycaemia (38%), poor weight gain (23%), and short stature (15%). Mutation analysis revealed nine heterozygous mutations; eight previously reported mutations (c.155 A > T, c.209 G > A, c.226 A > T, c.248 G > A, c.648 G > T, c.706 T > A, c.1022 T > A, c.262delG) and a novel mutation (c.325 T > C). The most common mutation found in Malaysian patients was c.648 G > T in ten patients (77%) of mostly Malay ethnicity, followed by c.248 G > A in 4 patients of Chinese ethnicity (30%). A novel missense mutation (c.325 T > C) was predicted to be disease-causing by various in silico software. Conclusions: The establishment of G6PC molecular genetic testing will enable the detection of presymptomatic patients, assisting in genetic counselling while avoiding the invasive methods of liver biopsy.

Coconut Palm: Food, Feed, and Nutraceutical Properties.

The price of traditional sources of nutrients used in animal feed rations is increasing steeply in developed countries due to their scarcity, high demand from humans for the same food items, and expensive costs of raw materials. Thus, one of the alternative sources is coconut parts or coconut as a whole fruit. Coconut is known as the 'tree of abundance', 'tree of heaven', and 'tree of life' owing to its numerous uses, becoming a very important tree in tropical areas for its provision of food, employment, and business opportunities to millions of people. Coconut contains a rich profile of macro and micronutrients that vary depending on the parts and how they are used. It is frequently chosen as an alternative source of protein and fiber. Its uses as an antibacterial agent, immunomodulant, and antioxidant further increase its importance. Using coconut oil in ruminant feed helps to minimize methane gas emissions by 18-30%, and to reduce dry matter intake up to 4.2 kg/d. The aquaculture sectors also use coconut palm as an alternative source because it significantly improves the digestion, growth, lipid metabolism, health, and antioxidative responses. However, coconut is not widely used in poultry diets although it has adequate amount of protein and carbohydrate due to anti-nutritional factors such cellulose (13%), galactomannan (61%), and mannan (26%). This review considered the importance and potential of coconut usage as an alternative ingredient in feed and supplements in various livestock sectors as it has plentiful nutrients and functional qualities, simultaneously leading to reduced feed cost and enhanced production.

Cardiogenic shock with complete heart block secondary to dengue myocarditis requiring temporary pacing.

This case illustrates acute myocarditis with complete heart block in a 13-year-old teenager as a rare complication of acute dengue illness. He required urgent temporary pacing with inotropic support and antifailure medications. Complete heart block in dengue myocarditis is an acute but reversible condition. A similar presentation in a dengue-endemic country or with a history of travelling to tropical countries warrants a suspicion of dengue infection.

Challenges in management of benign bone tumours complicated by pathological fracture in paediatric population.

BACKGROUND: Optimum treatment of pathological fractures following benign bone tumours in paediatric population is controversial. The usual difficulties encountered while dealing such cases is to establish a correct pre-operative diagnosis and to choose between conservative vs operative management. The aim of the work is to highlight the difficult aspects of diagnosis and management of pathological fractures following benign bone tumours in paediatric population. METHODS: All paediatric patients (<18 years) with pathological fractures following benign bone tumours were included. Pathological fractures due to infection, metabolic bone diseases and malignant bone tumours were excluded. Initial pre-operative diagnosis was based on clinico-radiological characteristics of the tumour and FNAC/needle biopsy, while final diagnosis was confirmed with post-operative histology. Primary outcome measure was determination of any disparity between pre-operative diagnosis and final post-operative histological diagnosis and the need of a separate open biopsy procedure for establishing the exact nature of lesion. Secondary outcome measures were determination of complications following surgery, functional grade and any recurrence at latest follow-up at 3 years. RESULTS: Out of 13 patients enrolled for the study, twelve patients met the inclusion criteria. Female to male quotient was 3:1, with average age of 12.17 years. We were able to make correct pre-operative diagnosis in 10 patients (83.3%) with systematic clinico-radiological analysis and carefully performed FNAC/needle biopsy. Disparity between pre-operative and final post-operative diagnosis was seen in two patients. In one of these two patients, initial pre-operative diagnosis was fibrous dysplasia, which turned out to be ossifying fibroma on final post-operative biopsy. While the other patient required an open biopsy to establish the nature of underlying pathology, as the pre-op histological evaluation revealed equivocal nature of bone lesion. Secondary outcome measures showed superficial infection in one, coxa vara in one, limb length discrepancy in 2 and fibular graft donor site morbidity in two. None of the patient had developed recurrence. All patients had complete healing of the fracture and lesion. CONCLUSION: A thorough clinico-radiological analysis and carefully performed FNAC/needle biopsy can establish a correct pre-operative diagnosis in majority of patients with benign bone tumours complicated by pathological fracture. This approach will avoid preventable delay in the definitive treatment of such patients, and also preclude the need of a separate operation prior to definitive management. In sight of the findings of our study along with existing literature we propose for definitive treatment in straight-forward cases and pre-treatment biopsy in cases with inconclusive FNAC/needle biopsy results and lesions with suspicion of malignancy. Proper diagnostic evaluation and differentiation of benign pathological fractures from malignant counterparts followed by extended curettage or excision of lesion and biological reconstruction with or without osteosynthesis represents a feasible approach for managing such fractures.

Gene expression of microbial gelatinase activity for porcine gelatine identification.

In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.

Base-Mediated Intramolecular Cyclization of α-Nitroethylallenic Esters as a Synthetic Route to 5-Hydroxy-3-pyrrolin-2-ones.

An unprecedented Cs2CO3-mediated intramolecular cyclization/rearrangement cascade that transforms α-nitroethylallenic esters to functionalized pyrrolin-2-ones has been uncovered. This reaction provides a new and practical approach for the synthesis of medicinally privileged 5-hydroxy-3-pyrrolin-2-ones under mild conditions. The broad potential of this new method was demonstrated by an efficient Au/Ag-catalyzed heteroarylation of 5-hydroxy-3-pyrrolin-2-ones employing electron-rich heteroarenes to furnish heteroaryl-lactam derivatives.

Case report: Ballotable abdominal mass in a child - Definitely renal in origin?

INTRODUCTION AND IMPORTANCE: The differential diagnosis of a paediatric abdominal mass can be extensive, as it potentially involves multiple organs including gastrointestinal, genitourinary, endocrine, and gynaecological systems. Hence, a systematic approach to history taking and physical examination is needed to clinch the diagnosis. Specifically, the approach for assessing, investigating, and managing a ballotable left hypochondrial mass in a child can be challenging. CASE PRESENTATION: We report a 10-year-old Dusun girl presenting with left hypochondrial pain and noted a left hypochondrial mass on examination. This report highlights the role of clinical imaging during the pre-operative and post-operative phases. CLINICAL DISCUSSION: Ultrasound and CT imaging was useful in determining that the tumor originated from the tail of the pancreas. The presence of a definite capsule with internal solid-cystic components helped narrowed the differential diagnosis to solid pseudopapillary neoplasm (SPN) of the pancreas. MR liver was useful to rule out liver metastasis in this child. INTERVENTION AND OUTCOME: The patient was scheduled for laparotomy and tumour excision at a regional paediatric centre. Successful excision of the tumor en-mass was performed and the child's subsequent recovery was uneventful. CONCLUSION: Clinical imaging plays a critical role in the diagnosis and management of paediatric solid organ tumours. Other than renal origin, suspicion of pancreatic tail origin should be considered by clinicians when encountering a ballotable left abdominal mass.

Utilization of Unsymmetric Diaryliodonium Salts in α-Arylation of α-Fluoroacetoacetamides.

The use of unsymmetric diaryliodonium salts as a versatile class of arylating agents has been demonstrated by developing a novel strategy to quickly access α-arylated α-fluoroacetoacetamides. The protocol provides a convenient metal-free method for the α-arylation of a diverse class of fluorinated acetoacetamides, and the products are obtained in good yields. The strategy, upon use of electron-deficient diaryliodonium salts as an arylating agent, provides α-fluoroacetamides through a spontaneous arylation/deacylation cascade.

Engineering domain-inlaid SaCas9 adenine base editors with reduced RNA off-targets and increased on-target DNA editing.

Precision genome engineering has dramatically advanced with the development of CRISPR/Cas base editing systems that include cytosine base editors and adenine base editors (ABEs). Herein, we compare the editing profile of circularly permuted and domain-inlaid Cas9 base editors, and find that on-target editing is largely maintained following their intradomain insertion, but that structural permutation of the ABE can affect differing RNA off-target events. With this insight, structure-guided design was used to engineer an SaCas9 ABE variant (microABE I744) that has dramatically improved on-target editing efficiency and a reduced RNA-off target footprint compared to current N-terminal linked SaCas9 ABE variants. This represents one of the smallest AAV-deliverable Cas9-ABEs available, which has been optimized for robust on-target activity and RNA-fidelity based upon its stereochemistry.

Substrate-controlled, PBu3-catalyzed annulation of phenacylmalononitriles with allenoates enables tunable access to cyclopentenes.

Divergence in the PBu3-catalyzed [3+2] annulation of phenacylmalononitriles with allenoates, controlled by the γ-substitution on allenoates, offers a tunable synthesis of multifunctionalized cyclopentene carboxamides and cyclopentenols. An unprecedented formation of cyclopentene carboxamide was observed when allenic esters bearing a substitution at the γ-position were employed, while unsubstituted allenoates produced cyclopentenols. The former reaction likely involves a Michael/aldol/nucleophilic cyclization sequence in a domino manner.

Performance comparison of EasyFix G26 and HYDRASYS 2 SCAN for the detection of serum monoclonal proteins.

BACKGROUND: Serum protein electrophoresis (SPE) is a widely used laboratory technique to diagnose patients with multiple myeloma (MM) and other disorders related to serum protein. In patients with MM, abnormal monoclonal protein can be detected by SPE and further characterized using immunofixation electrophoresis (IFE). There are several semi-automated agarose gel-based systems available commercially for SPE and IFE. In this study, we sought to evaluate the analytical performance of fully automated EasyFix G26 (EFG26) and semi-automated HYDRASYS 2 SCAN (H2SCAN) for both SPE and IFE. METHODS: Both instruments were operated according to manufacturer's instructions. Samples used include a commercially available normal control serum (NCS) and patients' specimens. The following were evaluated: precision and comparison studies for SPE, and reproducibility and comparison studies for IFE. Statistical analyses were performed using Microsoft Excel. RESULTS: For SPE repeatability study, our results showed that EFG26 has higher coefficient of variation (%CV) compared with H2SCAN for both samples except for monoclonal component with %CV of 0.97% and 1.18%, respectively. Similar results were obtained for SPE reproducibility study except for alpha-1 (4.16%) and beta (3.13%) fractions for NCS, and beta fractions (5.36%) for monoclonal sample. Subsequently, reproducibility for IFE was 100% for both instruments. Values for correlation coefficients between both instruments ranged from 0.91 to 0.98 for the five classic bands. CONCLUSION: Both instruments demonstrated good analytical performance characterized by high precision, reproducibility and correlation.

A functionally-distinct carboxylic acid reductase PcCAR4 unearthed from a repertoire of type IV CARs in the white-rot fungus Pycnoporus cinnabarinus.

Carboxylic acid reductases (CARs) are attracting burgeoning attention as biocatalysts for organic synthesis of aldehydes and their follow-up products from economic carboxylic acid precursors. The CAR enzyme class as a whole, however, is still poorly understood. To date, relatively few CAR sequences have been reported, especially from fungal sources. Here, we sought to increase the diversity of the CAR enzyme class. Six new CAR sequences from the white-rot fungus Pycnoporus cinnabarinus were identified from genome-wide mining. Genome and gene clustering analysis suggests that these PcCAR enzymes play different natural roles in Basidiomycete systems, compared to their type II Ascomycete counterparts. The cDNA sequences of all six Pccar genes were deduced and analysis of their corresponding amino acid sequence showed that they encode for proteins of similar properties that possess a conserved modular functional tri-domain arrangement. Phylogenetic analyses showed that all PcCAR enzymes cluster together with the other type IV CARs. One candidate, PcCAR4, was cloned and over-expressed recombinantly in Escherichia coli. Subsequent biotransformation-based screening with a panel of structurally-diverse carboxylic acid substrates suggest that PcCAR4 possessed a more pronounced substrate specificity compared to previously reported CARs, preferring to reduce sterically-rigid carboxylic acids such as benzoic acid. These findings thus present a new functionally-distinct member of the CAR enzyme class.