Areca nut-induced metabolic reprogramming and M2 differentiation promote OPMD malignant transformation.

BACKGROUND: Betel quid and its major ingredient, areca nut, are recognized by IARC as major risk factors in oral cancer development. Areca nut extract (ANE) exposure has been linked to OPMD progression and malignant transformation to OSCC. However, the detailed mechanism through which ANE acts on other cell types in the oral microenvironment to promote oral carcinogenesis remains elusive. METHODS: Immunoprofiling of macrophages associated with OPMD and OSCC was carried out by immunohistochemical and immunofluorescence staining. Phosphokinase and cytokine arrays and western blotting were performed to determine the underlying mechanisms. Transwell assays were used to evaluate the migration-promoting effect of ANE. Hamster model was finally applied to confirm the in vivo effect of ANE. RESULTS: We reported that M2 macrophages positively correlated with oral cancer progression. ANE induced M2 macrophage differentiation, CREB phosphorylation and VCAM-1 secretion and increased mitochondrial metabolism. Conditioned medium and VCAM-1 from ANE-treated macrophages promoted migration and mesenchymal phenotypes in oral precancer cells. In vivo studies showed that ANE enhanced M2 polarization and related signaling pathways in the oral buccal tissues of hamsters. CONCLUSION: Our study provides novel mechanisms for areca nut-induced oral carcinogenesis, demonstrating that areca nut promotes M2 macrophage differentiation and secretion of oncogenic cytokines that critically activate malignant transformation of oral premalignant cells.

Well controlled maternal inflammatory bowel disease does not increase the risk of abnormal neurocognitive outcome screening in offspring.

Background: Exposure to maternal inflammation is associated with an increased risk of neurocognitive and developmental disorders in offspring. Early diagnosis and intervention improves childhood motor and cognitive functioning. Neonatal cerebral MRI and remote app-based generalised movement assessments (GMAs) are both predictive of adverse neurocognitive outcomes but have only been used in infants at significantly increased risk for these outcomes, rather than following in utero exposure to maternal inflammatory disorders. Methods: Pregnant women with inflammatory bowel disease were assessed clinically and biochemically in each trimester of pregnancy in this single centre prospective study. Neonatal cerebral MRIs were performed at 6-12 weeks post-corrected term. Two GMA videos were filmed using the 'BabyMoves' app from 12 to 16 weeks of age. MRIs and GMAs were assessed by a blinded highly qualified practitioner using validated scoring systems. Results: 40/53 of invited maternal-infant dyads were recruited. C-reactive protein was elevated antenatally in less than 13%. 5/37 neonatal MRIs had incidental or obstetric trauma related gross anatomical abnormalities, with none abnormal on validated gross abnormality scoring. 3/35 GMAs were abnormal, with one GMA abnormality being clinically significant. Of those with abnormal GMAs, 2/3 were in exposed to severely active IBD in-utero. Conclusion: Neonatal cerebral MRI and GMA for neurocognitive screening is feasible in the setting of maternal inflammatory bowel disease, where the risk of cerebral palsy is poorly defined and thus burdensome screening interventions are less appealing to parents. Larger studies are required to stratify adverse neurocognitive outcome risk in infants born to women with maternal inflammatory disorders, but these data are reassuring for women with IBD in remission antenatally.

Neural-network-based solver for vesicle shapes predicted by the Helfrich model.

That a three-dimensional vesicle morphology can be modeled by an artificial neural network is proposed and demonstrated. In the phase-field representation, the Helfrich bending energy of a membrane is equivalently cast into field-based energy, which enables a more direct representation of a deformable, three-dimensional membrane surface. The core of our method is incorporating recent machine-learning techniques to perform the required energy minimization. The versatile ability of the method, to compute axisymmetric and nonsymmetric shapes, is discussed.

FISH Still a Very Important Tool to Monitor Breast Cancer: Review of Recent Literature, Alternative Methods, and Proposed Techniques.

OBJECTIVES: Fluorescent in situ hybridization has been the definitive modality in testing for overexpression of the Human Epidermal Growth Factor Receptor 2 (HER2) for decades to guide the appropriate treatment for cancer patients. In more recent years innovation and new techniques have been developed to supplant or even replace FISH as a standard method for biomarker testing. Alternative testing methods such polymerase chain reaction (PCR), next-generation sequencing (NGS), and other in situ hybridization (ISH)-derived techniques such as chromogenic-ISH (CISH) have been shown in multiple publications to have high concordance with FISH in addition to advantages in economics, logistics and practicality to the point where CISH and derived methods appear to have eclipsed FISH as a testing method of choice after immunohistochemistry (IHC). This review assesses the status of FISH compared to other diagnostic techniques such as IHC, CISH, and less common and/or experimental methods. Also addressed are the updates to the guidelines from the American Society of Clinical Oncology (ASCO), College of American Pathologists (CAP), and National Comprehensive Cancer Network (NCCN) regarding FISH and IHC for HER2 testing with the updates reducing the number of equivocal diagnoses in the latest iteration. Though our findings show a constantly changing technological landscape, FISH remains an important primary tool to guide medical treatment and as a solid foundation to build upon for innovation in cancer research.

Multinuclear non-heme iron dependent oxidative enzymes (MNIOs) involved in unusual peptide modifications.

Multinuclear non-heme iron dependent oxidative enzymes (MNIOs), formerly known as domain of unknown function 692 (DUF692), are involved in the post-translational modification of peptides during the biosynthesis of peptide-based natural products. These enzymes catalyze highly unusual and diverse chemical modifications. Several class-defining features of this large family (>14 000 members) are beginning to emerge. Structurally, the enzymes are characterized by a TIM-barrel fold and a set of conserved residues for a di- or tri-iron binding site. They use molecular oxygen to modify peptide substrates, often in a four-electron oxidation taking place at a cysteine residue. This review summarizes the current understanding of MNIOs. Four modifications are discussed in detail: oxazolone-thioamide formation, ß-carbon excision, hydantoin-macrocycle formation, and 5-thiooxazole formation. Briefly discussed are two other reactions that do not take place on Cys residues.

Transcatheter Aortic Valve Replacement (TAVR) Versus Surgical Aortic Valve Replacement (SAVR): A Review on the Length of Stay, Cost, Comorbidities, and Procedural Complications.

This review provides an in-depth analysis of the effect of length of stay (LOS), comorbidities, and procedural complications on the cost-effectiveness of transcatheter aortic valve replacement (TAVR) in comparison to surgical aortic valve replacement (SAVR). We found that the average LOS was shorter for patients undergoing TAVR, contributing to lower average costs associated with the procedure, although the LOS varied between patients due to the severity of illness and comorbidities present. TAVR has also been found to improve the quality of life for patients receiving aortic valve replacement compared to SAVR. Although TAVR has a lower rate of most post-operative complications caused by SAVR, such as bleeding and cardiac complications, TAVR shows an increased rate of permanent pacemaker (PPM) implantation due to mechanical trauma on the heart's conduction system. In addition, our findings suggest that the cost-effectiveness of each procedure varies based on the types of valve, the patient history of other medical conditions, and the procedural methods. Our findings show that TAVR is preferred over SAVR in terms of cost-effectiveness across a variety of patients with other coexisting medical conditions, including cancer, advanced kidney disease, cirrhosis, diabetes mellitus, and bundle branch block. TAVR also appears to be superior to SAVR with fewer post-operative complications. However, TAVR appears to have a higher rate of PPM implantation rates as compared to SAVR. The comorbidities of the valve recipient must be considered when deciding whether to use TAVR or SAVR as cost-effectiveness varies with the patient background.

Forced extension of a wormlike chain in the Gibbs and Helmholtz ensembles.

A semiflexible polymer can be stretched by either applying a force to it or by fixing the positions of its endpoints. The two approaches generally yield different results and correspond to experiments performed in either the Gibbs or Helmholtz statistical ensembles. Here, we derive the Helmholtz force-extension relationship for the commonly used wormlike-chain model in the strongly stretched regime. By analyzing it in comparison with the Gibbs ensemble result, we show that equivalence between the two relationships is achieved only in the long-chain thermodynamic limit.

The Safety and Comparative Effectiveness of Non-Psychoactive Cannabinoid Formulations for the Improvement of Sleep: A Double-Blinded, Randomized Controlled Trial.

BACKGROUND: Clinical evidence on the use of cannabidiol (CBD) for sleep remains limited. Even fewer studies have tested the comparative effectiveness of cannabinoid formulations found within CBD products used for sleep or how they compare to other complementary therapies such as melatonin. METHODS: Participants (N = 1,793 adults experiencing symptoms of sleep disturbance) were randomly assigned to receive a 4-week supply of 1 of 6 products (all capsules) containing either 15 mg CBD or 5 mg melatonin, alone or in combination with minor cannabinoids. Sleep disturbance was assessed over a period of 5 weeks (baseline week and 4 weeks of product use) using Patient-Reported Outcomes Measurement Information System (PROMIS™) Sleep Disturbance SF 8A, administered via weekly online surveys. A linear mixed-effects regression model was used to assess the differences in the change in sleep disturbance through time between each active product arm and CBD isolate. RESULTS: All formulations exhibited a favorable safety profile (12% of participants reported a side effect and none were severe) and led to significant improvements in sleep disturbance (p < 0.001 in within-group comparisons). Most participants (56% to 75%) across all formulations experienced a clinically important improvement in their sleep quality. There were no significant differences in effect, however, between 15 mg CBD isolate and formulations containing 15 mg CBD and 15 mg cannabinol (CBN), alone or in combination with 5 mg cannabichromene (CBC). There were also no significant differences in effect between 15 mg CBD isolate and formulations containing 5 mg melatonin, alone or in combination with 15 mg CBD and 15 mg CBN. CONCLUSIONS: Our findings suggest that chronic use of a low dose of CBD is safe and could improve sleep quality, though these effects do not exceed that of 5 mg melatonin. Moreover, the addition of low doses of CBN and CBC may not improve the effect of formulations containing CBD or melatonin isolate.

Sclerosing epithelioid fibrosarcoma associated with WRN gene variant presenting as chronic dyspnea and pathologic cervical fracture: a case report and review of the literature.

BACKGROUND: Sclerosing epithelioid fibrosarcoma is an aggressive sarcoma subtype with poor prognosis and limited response to conventional chemotherapy regimens. Diagnosis can be difficult owing to its variable presentation, and cases of sclerosing epithelioid fibrosarcoma are rare. Sclerosing epithelioid fibrosarcoma typically affects middle-aged individuals, with studies inconsistently citing gender predominance. Sclerosing epithelioid fibrosarcoma typically arises from the bones and soft tissues and often has local recurrence after resection and late metastases. Immunohistochemical staining typically is positive for mucin-4. Werner syndrome is due to an autosomal recessive mutation in the WRN gene and predisposes patients to malignancy. CASE PRESENTATION: A 37-year-old Caucasian female presented to the emergency department with 4 months of dyspnea and back pain. She had been treated for pneumonia but had persistent symptoms. A chest, abdomen, and pelvis computed tomography showed near-complete right upper lobe collapse and consolidation, mediastinal lymphadenopathy, lytic spinal lesions, and a single 15-mm hypodense liver nodule. The patient underwent a transthoracic right upper lobe biopsy, bronchoscopy, endobronchial ultrasound with transbronchial lymph node sampling, and bronchoalveolar lavage of the right upper lobe. The bronchoalveolar lavage cytology was positive for malignant cells compatible with poorly differentiated non-small cell carcinoma; however, the cell block materials were insufficient to run immunostains for further investigation of the bronchoalveolar lavage results. Consequently, the patient also underwent a liver biopsy of the liver nodule, which later confirmed a diagnosis of sclerosing epithelioid fibrosarcoma. Next-generation sequencing revealed a variant of unknown significance in the WRN gene. She was subsequently started on doxorubicin. CONCLUSION: Sclerosing epithelioid fibrosarcoma is a very rare entity, only cited approximately 100 times in literature to date. Physicians should be aware of this disease entity and consider it in their differential diagnosis. Though pulmonary involvement has been described in the context of sclerosing epithelioid fibrosarcoma, this malignancy may affect many organ systems, warranting extensive investigation. Through our diagnostic workup, we suggest a possible link between sclerosing epithelioid fibrosarcoma and the WRN gene. Further study is needed to advance our understanding of sclerosing epithelioid fibrosarcoma and its clinical associations as it is an exceedingly rare diagnosis.

A Review of the Cost Effectiveness of Transcatheter Aortic Valve Replacement (TAVR) Versus Surgical Aortic Valve Replacement (SAVR).

The cost of transcatheter aortic valve replacement (TAVR) has been studied in the context of high-risk or specific comorbidity populations; this paper provides a comprehensive overview of broader patient populations' outcomes and costs with TAVR in comparison to surgical aortic valve replacement (SAVR). In the past, SAVR had been the more cost-effective option than TAVR, but in recent years, TAVR has been becoming more cost-effective.Though the cost of TAVR can vary due to several factors the major focus of this review will focus on the surgical technique, medicare reimbursements, insertion point, and varying risk populations. In conclusion, the price of TAVR is declining as more cost-efficient valves arrive on the market. Climbing healthcare costs play a significant role in clinical decisions when deciding on which procedures are most cost-effective for the patient and healthcare system. The declining price of TAVR could lead to the preference of TAVR over SAVR for both low-risk and high-risk aortic stenosis patients.

Dynamic changes to the plant cuticle include the production of volatile cuticular wax-derived compounds.

The cuticle is a hydrophobic structure that seals plant aerial surfaces from the surrounding environment. To better understand how cuticular wax composition changes over development, we conducted an untargeted screen of leaf surface lipids from black cottonwood (Populus trichocarpa). We observed major shifts to the lipid profile across development, from a phenolic and terpene-dominated profile in young leaves to an aliphatic wax-dominated profile in mature leaves. Contrary to the general pattern, levels of aliphatic cis-9-alkenes decreased in older leaves following their accumulation. A thorough examination revealed that the decrease in cis-9-alkenes was accompanied by a concomitant increase in aldehydes, one of them being the volatile compound nonanal. By applying exogenous alkenes to P. trichocarpa leaves, we show that unsaturated waxes in the cuticle undergo spontaneous oxidative cleavage to generate aldehydes and that this process occurs similarly in other alkene-accumulating systems such as balsam poplar (Populus balsamifera) leaves and corn (Zea mays) silk. Moreover, we show that the production of cuticular wax-derived compounds can be extended to other wax components. In bread wheat (Triticum aestivum), 9-hydroxy-14,16-hentriacontanedione likely decomposes to generate 2-heptadecanone and 7-octyloxepan-2-one (a caprolactone). These findings highlight an unusual route to the production of plant volatiles that are structurally encoded within cuticular wax precursors. These processes could play a role in modulating ecological interactions and open the possibility for engineering bioactive volatile compounds into plant waxes.

A Randomized, Double-Blind, Placebo-Controlled Decentralized Trial to Assess Sleep, Health Outcomes, and Overall Well-Being in Healthy Adults Reporting Disturbed Sleep, Taking a Melatonin-Free Supplement.

Inadequate sleep is a global health concern. Sleep is multidimensional and complex; new multi-ingredient agents are needed. This study assessed the comparative effects of two multi-ingredient supplements on sleep relative to placebo. Adults (N = 620) seeking better sleep were randomly assigned to receive one of three study products. Sleep A (contained lower (0.35 mg THC and higher levels of botanicals (75 mg each hops oil and valerian oil), Sleep B (contained higher THC (0.85 mg) and lower botanicals (20 mg each hops oil and valerian oil) or placebo) for 4 weeks. Sleep disturbance was assessed at baseline and weekly using NIH's Patient-Reported Outcomes Measurement Information System (PROMIS™) Sleep Disturbance SF 8A survey. Anxiety, stress, pain, and well-being were assessed using validated measures at baseline and weekly. A linear mixed-effects regression model was used to assess the change in health outcome score between active product groups and the placebo. There was a significant difference in sleep disturbance, anxiety, stress, and well-being between Sleep A and placebo. There was no significant difference in any health parameter between Sleep B and placebo. Side effects were mild or moderate. There were no significant differences in the frequency of side effects between the study groups. A botanical blend containing a low concentration of THC improved sleep disturbance, anxiety, stress, and well-being in healthy individuals that reported better sleep as a primary health concern.

Female Pattern Hair Loss: An Overview with Focus on the Genetics.

Pattern hair loss can occur in both men and women, and the underlying molecular mechanisms have been continuously studied in recent years. Male androgenetic alopecia (M-AGA), also termed male pattern hair loss, is the most common type of hair loss in men. M-AGA is considered an androgen-dependent trait with a background of genetic predisposition. The interplay between genetic and non-genetic factors leads to the phenotype of follicular miniaturization. Although this similar pattern of phenotypic miniaturization can also be found in female pattern hair loss (FPHL), the corresponding genetic factors in M-AGA do not account for the phenotype in FPHL, indicating that there are different genes contributing to FPHL. Therefore, the role of genetic factors in FPHL is still uncertain. Understanding the genetic mechanism that causes FPHL is crucial for the future development of personalized treatment strategies. This review aims to highlight the differences in the ethnic prevalence and genetic background of FPHL, as well as the current genetic research progress in nutrition, Wnt signaling, and sex hormones related to FPHL.

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review.

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

Macrocyclization and Backbone Rearrangement During RiPP Biosynthesis by a SAM-Dependent Domain-of-Unknown-Function 692.

The domain of unknown function 692 (DUF692) is an emerging family of post-translational modification enzymes involved in the biosynthesis of ribosomally synthesized and post-translationally modified peptide (RiPP) natural products. Members of this family are multinuclear iron-containing enzymes, and only two members have been functionally characterized to date: MbnB and TglH. Here, we used bioinformatics to select another member of the DUF692 family, ChrH, that is encoded in the genomes of the Chryseobacterium genus along with a partner protein ChrI. We structurally characterized the ChrH reaction product and show that the enzyme complex catalyzes an unprecedented chemical transformation that results in the formation of a macrocycle, an imidazolidinedione heterocycle, two thioaminals, and a thiomethyl group. Based on isotopic labeling studies, we propose a mechanism for the four-electron oxidation and methylation of the substrate peptide. This work identifies the first SAM-dependent reaction catalyzed by a DUF692 enzyme complex, further expanding the repertoire of remarkable reactions catalyzed by these enzymes. Based on the three currently characterized DUF692 family members, we suggest the family be called multinuclear non-heme iron dependent oxidative enzymes (MNIOs).

A remarkable transformation catalyzed by a domain-of-unknown-function 692 during the biosynthesis of a new RiPP natural product.

The domain of unknown function 692 (DUF692) is an emerging family of posttranslational modification enzymes involved in the biosynthesis of ribosomally-synthesized and posttranslationally modified peptide (RiPP) natural products. Members of this family are multinuclear iron-containing enzymes and only two members have been functionally characterized to date: MbnB and TglH. Here, we used bioinformatics to select another member of the DUF692 family, ChrH, that is ubiquitously encoded in the genomes of the Chryseobacterium genus along with a partner protein ChrI. We structurally characterized the ChrH reaction product and show that the enzyme catalyzes an unprecedented chemical transformation that results in the formation of a macrocycle, an imidazolidinedione heterocycle, two thioaminals, and a thiomethylation. Based on isotopic labeling studies, we propose a mechanism for the four-electron oxidation and methylation of the substrate peptide. This work identifies the first SAM-dependent DUF692 enzyme, further expanding the repertoire of remarkable reactions catalyzed by these enzymes.

Plumbagin induces the apoptosis of drug-resistant oral cancer in vitro and in vivo through ROS-mediated endoplasmic reticulum stress and mitochondrial dysfunction.

BACKGROUND: Oral cancer is one of the leading causes of cancer-related deaths worldwide. Chemotherapy is widely used in the treatment of oral cancer, but its clinical efficacy is limited by drug resistance. Hence, novel compounds capable of overcoming drug-resistance are urgently needed. PURPOSE: Plumbagin (PG), a natural compound isolated from Plumbago zeylanica L, has been used to treat various cancers. In this study, we investigated the anticancer effects of PG on drug-resistant oral cancer (CR-SAS) cells, as well as the underlying mechanism. METHODS: MTT assays were used to evaluate the effect of PG on the viability of CR-SAS cells. Apoptosis and reactive oxygen species (ROS) production by the cells were determined using flow cytometry. Protein expression levels were detected by western blotting. RESULTS: The results show that PG reduces the viability and causes the apoptosis of CR-SAS cells. PG is able to induce intracellular and mitochondrial ROS generation that leads to mitochondrial dysfunction. Furthermore, endoplasmic reticulum (ER) stress was triggered in PG-treated CR-SAS cells. The inhibition of ROS using N-acetylcysteine (NAC) abrogated the PG-induced ER stress and apoptosis, as well as the reduction in cell viability. Meanwhile, similar results were observed both in zebrafish and in murine models of drug-resistant oral cancer. CONCLUSION: Our results indicate that PG induces the apoptosis of CR-SAS cells via the ROS-mediated ER stress pathway and mitochondrial dysfunction. It will be interesting to develop the natural compound PG for the treatment of drug-resistant oral cancer.

The Incidence of Alopecia Areata in a COVID-19-Vaccinated Population: A Single-Center Review.

Background Cases of alopecia areata (AA) attributed to the coronavirus disease 2019 (COVID-19) vaccination have been reported in recent literature. However, these reports are reflective of specific geographic areas, and whether this phenomenon is observed in other regions remains to be investigated. This study focused on the association between AA and COVID-19 vaccination among patients from a large single-center safety net hospital in California. Methodology In this study, using electronic health records of patients and publicly available vaccination data, the demographics of patients including age group, sex, and race along with the vaccination status were carefully reviewed. Results A total of 73 cases of AA in the period from the release of the COVID-19 vaccination on December 17, 2020, to February 10, 2023, were identified. The odds ratios (ORs) for developing AA among the vaccinated and unvaccinated for each demographic level were calculated. Among all vaccinated individuals, the OR for developing AA was 0.58 (95% confidence interval (CI) = 0.35-0.94, p-value = 0.02). Conclusions This investigation noted no apparent increase in the incidence of AA among the vaccinated population compared to the unvaccinated population.

Imaging volumes during COVID-19: A Victorian health service experience.

BACKGROUND: The World Health Organisation declared the coronavirus disease 2019 (COVID-19) a pandemic on March 11, 2020. While globally, the relative caseload has been high, Australia's has been relatively low. During the pandemic, radiology services have seen significant changes in workflow across modalities and a reduction in imaging volumes. AIM: To investigate differences in modality imaging volumes during the COVID-19 pandemic across a large Victorian public health network. METHODS: A retrospective analysis from January 2019 to December 2020 compared imaging volumes across two periods corresponding to the pandemic's first and second waves. Weekly volumes across patient class, modality and mobile imaging were summed for periods: wave 1 (weeks 11 to 16 for 2019; weeks 63 to 68 for 2020) and wave 2 (weeks 28 to 43 for 2019; weeks 80 to 95 for 2020). Microsoft Power Business Intelligence linked to the radiology information system was used to mine all completed examinations. RESULTS: Summed weekly data during the pandemic's first wave showed the greatest decrease of 29.8% in adult outpatient imaging volumes and 46.3% in paediatric emergency department imaging volumes. Adult nuclear medicine demonstrated the greatest decrease of 37.1% for the same period. Paediatric nuclear medicine showed the greatest decrease of 47.8%, with angiography increasing by 50%. The pandemic's second wave demonstrated the greatest decrease of 23.5% in adult outpatient imaging volumes, with an increase of 18.2% in inpatient imaging volumes. The greatest decrease was 28.5% in paediatric emergency department imaging volumes. Nuclear medicine showed the greatest decrease of 37.1% for the same period. Paediatric nuclear medicine showed the greatest decrease of 36.7%. Mobile imaging utilisation increased between 57.8% and 135.1% during the first and second waves. A strong correlation was observed between mobile and non-mobile imaging in the emergency setting (Spearman's correlation coefficient = -0.743, P = 0.000). No correlation was observed in the inpatient setting (Spearman's correlation coefficient = -0.059, P = 0.554). CONCLUSION: Nuclear medicine was most impacted, while computed tomography and angiography were the least affected by the pandemic. The impact was less during the pandemic's second wave. Mobile imaging shows continuous growth during both waves.

Evolution and molecular basis of substrate specificity in a 3-ketoacyl-CoA synthase gene cluster from Populus trichocarpa.

Very long chain fatty acids (VLCFAs) are precursors to sphingolipids, glycerophospholipids, and plant cuticular waxes. In plants, members of a large 3-ketoacyl-CoA synthase (KCS) gene family catalyze the substrate-specific elongation of VLCFAs. Although it is well understood that KCSs have evolved to use diverse substrates, the underlying molecular determinants of their specificity are still unclear. In this study, we exploited the sequence similarity of a KCS gene cluster from Populus trichocarpa to examine the evolution and molecular determinants of KCS substrate specificity. Functional characterization of five members (PtKCS1, 2, 4, 8, 9) in yeast showed divergent product profiles based on VLCFA length, saturation, and position of the double bond. In addition, homology models, rationally designed chimeras, and site-directed mutants were used to identify two key regions (helix-4 and position 277) as being major determinants of substrate specificity. These results were corroborated with chimeras involving a more distantly related KCS, PtCER6 (the poplar ortholog of the Arabidopsis CER6), and used to show that helix-4 is necessary for the modulatory effect of PtCER2-like5 on KCS substrate specificity. The role of position 277 in limiting product length was further tested by substitution with smaller amino acids, which shifted specificity toward longer products. Finally, treatment with KCS inhibitors (K3 herbicides) showed varying inhibitor sensitivities between the duplicated paralogs despite their sequence similarity. Together, this work sheds light on the molecular mechanisms driving substrate diversification in the KCS family and lays the groundwork for tailoring the production of specific VLCFAs.