Chain Synthesis Research Articles

Enzymatic Modification of Starch Using Recombinant Genes from Sorghum in Escherichia coli: Insights and Potential Applications.

SBEIIb (Sobic.004G163700), SSSIIa (Sobic.010G093400), and GBSSI (Sobic.010G022600) genes that regulate starch synthesis in sorghum endosperm were transferred into Escherichia coli by transgenic technology. SBEIIb, SSSIIa, and GBSSI enzymes were separated and purified through a Ni column and analyzed by electrophoresis with molecular weights and activities of 91.57 84.57, and 66.89 kDa and 551 and 700 and 587 U/μL, respectively. Furthermore, they were applied to starch modification, yielding interesting findings: the A chain content increased from 25.79 to 89.55% for SBEIIb-treated waxy starch, while SSSIIa extended the A chain to form DPs of the B chain, with A chain content decreasing from 89.55 to 37.01%, whereas GBSSI was explicitly involved in the synthesis of B1 chain, with its content increasing from 9.59 to 48.45%. Modified starch was obtained, which could be accurately applied in various industries. For instance, we prepared a sample (containing 89.6% A chain content) with excellent antiaging and antidigestion properties through SBEIIb modification. Moreover, higher RS3 (34.25%) and SDS contents (15.75%) of starch were obtained through the joint modification of SBEIIb and SSSIIa. These findings provide valuable insights for developing sorghum starch synthesis-related enzymes and offer opportunities for improving starch properties through enzymatic approaches.

Lateral facial profile of β-thalassemia major in Javanese children: a photogrammetric analysis

BACKGROUND Impairment of globin chain synthesis in patients with β-thalassemia major causes ineffective erythropoiesis. This condition triggers bone marrow hyperplasia and can lead to craniofacial bone abnormalities. This study aimed to evaluate the lateral facial profile of β-thalassemia major, identify any differences when compared with a control group of similar age and ethnicity, and reveal the facial profile of β-thalassemia major in Javanese children.
 METHODS This cross-sectional study included 35 β-thalassemia major children aged 7–15 years. They were divided into 3 groups based on their age. Lateral facial photogrammetry was taken by measuring the forehead protrusion and nasolabial angle. Data were then mapped to the normal group of children in the same age group and descriptively analyzed using SPSS software.
 RESULTS The 1 and 2 SD group had a higher prevalence of β-thalassemia major in children aged 7–9 years for both sexes. The older age group had a closer mean value to those of children without thalassemia.
 CONCLUSIONS The forehead and maxillary profile of Javanese β-thalassemia major children tended to be protrusive, especially in the 7–9 years age group, while the older age groups had closer mean values to those of children without thalassemia.

Urinary biomarkers of early kidney injury in children with beta-thalassemia

Beta-thalassemia is considered as one of the most common genetic disorders in the world caused by the reduced or absent synthesis of b-globin chain. The aim of this work was to evaluate renal function in children with b-thalassemia using predictive biomarkers such as urinary neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl-b-D-glycosaminidase (NAG). This prospective case–control study was carried out on 80 subjects aged between 3 and 17 years. The subjects were divided into two equal groups: thalassemia group which included 40 children with b-thalassemia major, and control group which included 40 age- and gender-matched healthy, non-anemic controls without any diseases that could potentially affect renal function, who underwent routine check-ups. All thalassemia patients received chelation therapy: 35 (87.5%) of them were treated with deferasirox and 5 (12.5%) patients received deferasirox + deferoxamine. The results of echocardiography, kidney function tests (serum creatinine, urea and estimated glomerular filtration rate as well as urinary albumin/creatinine ratio and urinary NGAL/urinary albumin–creatinine ratio were insignificantly different between the two groups. Abdominal ultrasound findings were significantly different between both groups. Total WBC counts, platelet counts, the results of liver function tests (total bilirubin, direct bilirubin, alanine transaminase and aspartate aminotransferase), urinary NAG/creatinine ratios, urinary NGAL/creatinine ratios and serum ferritin levels were significantly higher in the thalassemia group, while hemoglobin, urinary NAG/urinary albumin–creatinine ratios were significantly lower in this group. Urinary markers NGAL and NAG could be used as predictive markers of renal disease in b-thalassemia major patients. The study was initiated after obtaining approval from the Ethical Committee of Menoufia University Hospital. Informed written consent was obtained from the parents of the children involved in the study.

Structural Dynamics of E6AP E3 Ligase HECT Domain and Involvement of a Flexible Hinge Loop in the Ubiquitin Chain Synthesis Mechanism.

Ubiquitin (Ub) ligases E3 are important factors in selecting target proteins for ubiquitination and determining the type of polyubiquitin chains on the target proteins. In the HECT (homologous to E6AP C-terminus)-type E3 ligases, the HECT domain is composed of an N-lobe and a C-lobe that are connected by a flexible hinge loop. The large conformational rearrangement of the HECT domain via the flexible hinge loop is essential for the HECT-type E3-mediated Ub transfer from E2 to a target protein. However, detailed insights into the structural dynamics of the HECT domain remain unclear. Here, we provide the first direct demonstration of the structural dynamics of the HECT domain using high-speed atomic force microscopy at the nanoscale. We also found that the flexibility of the hinge loop has a great impact not only on its structural dynamics but also on the formation mechanism of free Ub chains.

Synthesis of Long Chain Oxygenates via Aldol Condensation of Furfural and Acetone over Metal-Organic Frameworks.

Enormous efforts have been made to convert biomass to liquid fuels and products catalytically. Long molecules with a suitable structure are ideal precursors for fuels and value-added products. Here, a C21 oxygenate was synthesized for the first time in one step through aldol condensation of furfural and acetone over the amine-functionalized zirconium-based metal-organic framework (MOF), UiO-66-NH2. Structural changes of UiO-66-NH2 were investigated to improve the yield and evaluate the role of the ligand, cluster node, defectiveness, modulator, surface area, and textural properties on the product distribution. We demonstrate the possibility of making long-chain oxygenates without using vegetable oil-derived fatty acids toward 100% waste biomass-derived renewable fuels, lubricants, and surfactants.

Sir David John Weatherall. 9 March 1933—8 December 2018

Sir David Weatherall was the outstanding, internationally recognized, clinician scientist of his generation. His lifelong interest in the haemoglobinopathies first came from studying a child that he recognized as having beta thalassaemia while working as an army physician in Malaya. His interest in these diseases further developed as he undertook his PhD in the Department of Haematology under the supervision of Lockard Conley and Victor McKusick in Baltimore. There, together with John Clegg (FRS 1999), he developed the technology to directly measure the synthesis of the alpha and beta globin chains of haemoglobin, and his subsequent work at the University of Liverpool showed that thalassaemia resulted from imbalanced globin chain synthesis. Importantly, using the globin genes as their model, David's laboratory went on to make many of the first discoveries of how expression of the globin genes and mammalian genes in general could be perturbed to cause human genetic diseases. As professor of medicine in Oxford, he established one of the first institutes to develop the use of molecular biology in medicine and he trained many of the world's leading clinician scientists in this area of biomedical research. He also established worldwide networks to apply molecular biology to the haemoglobinopathies and infectious diseases, making a unique contribution to global medicine. He had outstanding qualities as a clinician, a scientist, and a leader, all of which he achieved with great humility and humanity.

A Novel Beta Globin Frameshift Mutation Causing Autosomal Dominant Beta Thalassemia

Background: Dominantly inherited β-Thalassemia (β-thal) is a rare condition that results from a heterozygous mutation in the β-globin gene ( HBB), leading to the synthesis of an unstable β-globin chain, most frequently an elongated protein. Although heterogeneous, it presents not as β-thalassemia trait but rather with a more severe phenotype, resembling β-thal major or intermedia, with chronic hemolytic anemia and splenomegaly. There are approximately 150 known dominantly inherited α- and β-globin gene mutations (http://globin.cse.psu.edu/). We present a case of a novel HBB mutation leading to a dominant form of β-thalassemia, outlining our approach to attaining an appropriate diagnosis and management leading to transfusion independence. Case: A 32-year-old Caucasian female was referred to our center with a diagnosis of congenital dyserythropoietic anemia type II (CDA-II), based on bone marrow studies at 12 years of age which had demonstrated a hypercellular marrow with erythroid hyperplasia and 10% binucleated red cells. Molecular testing had not been performed. Her history was negative for developmental delay, growth retardation, or family history of anemia. She had presented to medical attention at age 11 with symptomatic anemia. Prior treatments included steroids, IVIG, and erythropoietin, with no significant improvement of her anemia. She underwent splenectomy at 19 years of age due to the hemolytic component of her anemia with the clinical diagnosis of CDA-II, with a mild improvement in baseline hemoglobin from 70-80g/L to 80-90g/L. Spleen pathology demonstrated splenomegaly (weight of 1kg) and mild iron deposition. At the time of presentation at our centre, her predominant symptom was fatigue, for which she was initiated on a chronic transfusion protocol, to maintain a pretransfusion hemoglobin of 90 g/L; she received a total of 53 units from October 2018 to November 2022. She subsequently developed worsening iron overload (ferritin 888, TSAT 80%, and LIC of 8.1mg of iron per gram of liver dry weight) requiring initiation of iron chelation therapy. Given her presumptive diagnosis of CDA-II she was later enrolled in the Congenital Dyserythropoietic Anemia Registry (CDAR) for North America (https://www.clinicaltrials.gov/study/NCT02964494). Molecular testing by next generation sequencing (NGS) on a CDA gene-panel at that time failed to identify a causative CDA mutation. Further testing with whole exome sequencing revealed a one base-pair deletion in exon 2 of the β-globin gene, creating a frameshift variant at codon 96 and ending in a premature STOP, 63 codons downstream p.(Lys 96Asnfs*63) (Figure 1). This mutation led to an elongated β-globin chain and an unstable hemoglobinopathy predicted to be the cause of her presentation. Hemoglobinopathy screen revealed HBF 8.7%, HBA 87.5%, and HBA2 3.8%. Based on the above testing, a diagnosis of dominant β-thalassemia intermedia due to HBB NM_00518.4, c.288delG, p.K96fs, recognizing that she had been previously misdiagnosed with CDA-II. Based on the revised diagnosis, the patient was initiated on Luspatercept 1mg/kg SC q3 weeks, with rapid improvement in her pre-transfusion hemoglobin to >100g/L as well as in her symptomatology and quality of life (Figure 2), rendering her transfusion independent. Discussion: This case report, to our knowledge, demonstrates a novel β-globin gene mutation leading to dominant β-thalassemia, with the phenotype of β-thal-intermedia. The latency between presentation and diagnosis demonstrates the challenges associated with diagnosing rare hemolytic anemias and highlights the importance of molecular testing to confirm the diagnosis, especially before proceeding to splenectomy which may predispose to vasculopathies in some of these diseases, such as congenital dyserythropoietic anemia type I and unstable hemoglobinopathies.

Topolectrical Circuit Correspondence Design of Polyacetylene

In cis and trans geometrical configurations of the polyacetylene molecule, one-dimensional chain is constructed by attaching a number of identical –HC=CH– units one-by-one. We attach as many units as required to obtain the chain of the desired length. In case of a very long polyacetylene chain, which is practically considered infinite in length, a periodic unit is defined, so that its band structure would be calculable. Then, the electronic properties and topological properties of the chain can be predicted. Since experimental synthesis of single-layer polyacetylene chain has lots of limitations, in an alternative approach, emulation of a tight-binding model is used to describe the electron transfer in polyacetylene polymer chain. In case of either synthesis or testing the polyacetylene molecule, it is necessary to improvise a one-to-one correspondence between polyacetylene polymer and topological circuit, which is introduced for the first time in the present study. To this aim, the outputs of density functional theory calculations alongside with the calculations based on the physical chemistry formalisms are used. Here, we observed that the electronic response of the circuit is topologically sustained at frequencies where the coupling was pre-determined via high precision quantum system equivalent topolectrical circuit, as an alternative classical system, to study electron transfer of trans-polyacetylene polymer quantum chain by the precision of one-electron.

Body Iron Status and Its Complications in Patients With Beta Thalassemia Major: A Cross-Sectional Study

Introduction: Thalassemia is a genetic condition and is one of the commonest single-gene hereditary disorders. As it is among a group of hemoglobinopathies, it consists of a decrease in either alpha or beta globin chain synthesis. This eventually leads to the inappropriate ratio of alpha or beta globin chains causing ineffective erythropoiesis. Ineffective erythropoiesis thus causes chronic anemia and haemopoietic expansion to compensate for it.
 Aims & Objectives: This study aimed to investigate the serum ferritin levels of patients with beta thalassemia major presenting in a tertiary care hospital in Lahore, Pakistan and study the complications that occur with an abnormal iron load.
 Place and Duration of Study: It was conducted at CMH Hospital, Lahore, and completed over a period of one and a half year, from June 2021 to January 2023.
 Material & Methods: It was a descriptive cross-sectional study. The sample size of 32 was calculated using Raosoft calculator, with 90% Confidence Interval, 9% margin of error and 10.5% response distribution.Data was collected using an interviewer-administered questionnaire that compromised of 4 parts, demographics and socio-economic background of patient and caretakers; medical history and anthropometric measurement of the patient; details regarding serum ferritin levels and chelation; and lastly, laboratory (for example, TSH, T4, HbA1c and ALT for all patients, as well as FSH and LH for only those patients greater than 10 years of age), ultrasound, and cardiac echocardiography findings.Collected data was entered and analyzed in SPSS version 24. P value of <0.05 was taken as significant.
 Results: In this study, thirty-two patients with beta thalassemia major were included with mean age of 7.79 ± 4.57 years. Mean serum ferritin was 3410±2629µg/l and lack of compliance to chelation had significant association with serum ferritin values (p=0.05). Serum ALT levels showed that hepatic dysfunction was the most common endocrine complication in 17 (53.1%) patients. There was a significant association between compliance and echocardiography findings (p=0.04). No significant association of compliance was found with ultrasound findings, serum TSH and T4 levels, serum ALT levels and serum FSH and LH levels.
 Conclusion: This study concluded that high ferritin levels ultimately lead to significant complications.

The Spectrum of α-Thalassemia Mutations in Syrian Patients

α-Thalassemia (α-thal) is a globally prevalent genetic disorder of hemoglobin (Hb) structure where the rate of α-globin chain synthesis is reduced or absent due to the presence of α-globin mutation(s). The aim of this study is to define the spectrum of α-globin gene mutations and evaluate their allele frequency in a group of α-thal carriers. A total of 55 individuals with possible α-thal patients were referred from the thalassemia centers in Syria. They have unexplained hypochromia and microcytosis. All patients were genetically tested for 21 common α-globin gene mutations using reverse hybridization kit. Seven different α-globin gene mutations and 13 different genotypes were detected in 55 patients. The two most frequently encountered mutations were -α3.7 deletion (47.1%) and --MED mutation (21.4%). The most commonly observed genotype was -α3.7/αα (40%), followed by --MED/αα genotype (21.8%). We determined the most common α thalassemia mutations in the Syrian patients. α-Thalassemia mutations with deletions were mostly observed in our study.

Translating an HPFH-Mechanism into Oral Small Molecule Therapy for Beta-Hemoglobinopathies: Clinical Proof-of-Principle

Introduction: Hereditary persistence of fetal hemoglobin (HPFH) down-modulates co-inherited sickle cell disease (SCD) severity, encouraging characterization of HPFH-mechanisms for interventional reprise. One HPFH mechanism is polymorphisms in DNA methyltransferase 1( DNMT1) that decrease DNMT1 protein stability (Gong et al, Blood 2021), agreeing with biochemical observations that DNMT1 mediates repression of fetal hemoglobin (HbF) genes by BCL11A. Here we describe translation of this HPFH-mechanism into oral therapy for SCD patients at high-risk for early mortality (Steinberg et al, JAMA 2004) despite standard-treatments. Methods and Results: The small molecule decitabine (Dec) contains a pyrimidine ring modification that binds and depletes DNMT1 and a natural deoxyribose that incorporates into DNA without terminating chain synthesis: minimum biologically effective doses of Dec, to deplete DNMT1 without cytotoxicity, can thus be found (reviewed in Zavras et al, Clin Ca Res, 2021). Other key properties of Dec are tropism to hematopoietic precursors, driven by high expression in these cells of deoxycytidine kinase that phosphorylates Dec, and rapid catabolism in vivo by cytidine deaminase (CDA), that severely restricts Dec bioavailability and half-life. We therefore combined Dec with a CDA-inhibitor tetrahydrouridine (THU): dose and schedule of THU/Dec that depleted DNMT1 without cytotoxicity to hematopoietic precursors in vivo were identified in non-human primate studies and Phase 1 clinical trials (Molokie et al, PLoS Med 2017), and here we describe interim results from proof-of-principle study in patients with SCD ( Table 1). Study interventions were oral THU/Dec (~10/0.2 mg/kg) 1X/week with or without oral nicotinamide (vitamin B3) 1 g/day. B3 was studied because it is a direct precursor of NADH, a fundamental antioxidant currency and also a cofactor for epigenetic enzymes that channel hematopoiesis to erythropoiesis vs megakaryopoiesis, to potentially counter an expected side-effect of THU/Dec of increasing platelets. Randomization was to THU/Dec vs B3 for 12 weeks, followed by THU/Dec + B3 for 12 weeks, then option to extend therapy for a further 24 weeks. Standard clinical and laboratory parameters were measured. Six patients enrolled, were randomized equally to THU/Dec or B3, and opted to extend. Dose-limiting toxicities (DLTs), including neutropenia or thrombocytosis, did not occur ( Table 1). In the year preceding study-treatment, 15 vaso-occlusive crises (VOC) requiring hospitalization were documented ( Table 1). By comparison, during 52 weeks on-study (48 weeks on-therapy, 4 weeks follow-up), the grade 3/4 adverse events were VOC hospitalizations x3 (1 during follow-up without therapy, 1 during B3 alone, 1 during B3 + THU/Dec therapy), hyperkalemia x2, and non-cardiac chest pain x1 ( Table 1)(p=0.04, paired t-test 2-sided). THU/Dec dose (7.6/0.15 mg/kg) was below the Phase 1 identified minimum biologically effective dose window (8-12/0.16-0.25 mg/kg, protocol since amended to accommodate high body weights) in one patient (TDN04) who accordingly did not have HbF% or hemoglobin increases ( Fig.1). In the 5 other patients, HbF increases (pre-treatment to maximum) were: 9.4 to 17.3, 5.9 to 11, 3.4 to 9.3, 3.3 to 16.3 and 5.7 to 10 % ( Fig.1). There were corresponding improvements in hemolysis and coagulation pathway parameters (LDH, total bilirubin, D-Dimer), and total hemoglobin increased from 9.9 to 11.5, 8.7 to 10.6, 6.6 to 7.7, 5.7 to 7.1 and 8 to 9.7 g/dL respectively. TDN01 and 06, the two patients with lowest pre-treatment hemoglobin, requested and resumed THU/Dec post-study by Expanded Access. Conclusions: This is the longest-term treatment to date of oral THU/Dec to target DNMT1 in patients with SCD, with or without B3. Subjective and objective improvements were sustained without DLTs in high-risk patients who displayed known negative prediction markers for response to hydroxyurea (HbF% <7.5%, reticulocyte count <300 x10 9/L - Steinberg et al, Blood 1997). The safety and efficacy signals align with scientific target validation data, and together with accessibility, support relevance to SCD patient needs and goals worldwide, bearing in mind major study limitations of single-site enrollment and only 6 patients.

Family Psychoeducation to Improve Parents' Coping Strategies in Caring for Thalassemia Children

Thalassemia is a genetic disorder of the synthesis of alpha or beta globin chains, either in whole or in part. Families who care for children with thalassemia will experience psychosocial problems. Ignorance is the reason why families find it difficult to adapt. Therefore, it is necessary to provide knowledge and the ability to adapt to stressors so that family coping is positive. This study aims to determine the effect of Family Psychoeducation on parents' coping strategies in caring for children with thalassemia. The research design used a "Quasi experiment pre-post-test with a control group." The purposive sampling technique was used with a sample of 44 people divided into two groups. The instrument used is Brief COPE. The results showed that in the intervention group, there was a significant difference in the average score with a p-value of 0.000. Meanwhile, in the control group, there was no significant difference in the average score with a p-value of 0.492. There is a difference in the average score between the intervention group and the control group, with a p-value of 0.023. In conclusion, there is an influence of family psychoeducation on parents' coping strategies in caring for children with thalassemia.

Nanoscale analysis of magnetic chains consisting of cobalt mesospheres by full‐field transmission x‐ray tomography

AbstractFull‐field transmission x‐ray tomography can obtain 3D morphology and configurations of nanoscale materials. In this study, we further demonstrate the feasibility of this technique using magnetic chains consisting of cobalt mesospheres. The preliminary images presented in this article clearly reveal that three types of cobalt nanoparticles, namely, hollow, core–shell, and solid were found for magnetic chain synthesis. Furthermore, the tomographic analyses revealed the growth mechanism of magnetic chains self‐assembled by cobalt nanoparticles. We may claim that the spatial resolution and contrast characteristics of the full‐field transmission x‐ray tomography can satisfy the research requirements of nanomaterial science. Hence, transmission x‐ray tomography could be a powerful complementary method for imaging and analysis of nanoscale materials.

Clinical Profile of Children with Thalassemia Admitted for Blood Transfusion at a Tertiary Health Care Center

IntroductionThalassemia is a prevalent hereditary hematological disorder that is characterized by a reduction or absence of globin chain synthesis. The objective of this study is to determine the clinical profile of children with thalassemia who undergo repeated packed cell transfusions.MethodsA prospective cross-sectional observational study was conducted from January 1, 2023, to May 31, 2023, in the Pediatric ward at Bharatpur Hospital. Ethical clearance was obtained from the Institutional Review Committee of Bharatpur Hospital (Ref: 078/79-018). A total of 53 cases of Thalassemia, who were receiving regular blood transfusions, were included in this study.ResultsThe prevalence of thalassemia was 3.68% (with 95% CI 2.7% to 4.65%). The average age at diagnosis was 15.58 months, with a range of 2 to 97 months. The majority of cases, 32 (60.37%), were diagnosed before the age of one year, with a male-to-female ratio of 1.2:1. Thalassemia was more prevalent in the Tharu community (58.5%) compared to other communities. ConclusionsThalassemia is a hematological disorder that predominantly affects the Tharu community. Common clinical manifestations of transfusion-dependent thalassemia in children include pallor, hepatomegaly, splenomegaly, and facial deformities. Therefore, it is imperative to monitor serum ferritin levels to detect iron overload early and initiate chelation therapy promptly to prevent complications. Such measures can significantly improve the quality of life of affected individuals and reduce the burden of this genetic disorder on affected communities.

Efficient Synthesis of Highly Crystalline One-Dimensional CrCl3 Atomic Chains with a Spin Glass State.

One-dimensional (1D) magnetic material systems have attracted widespread interest from researchers because of their peculiar physical properties and potential applications in spintronics devices. However, the synthesis of 1D magnetic atomic chains has seldom been investigated. Here, we developed an iodine-assisted vacuum chemical vapor-phase transport (I-VCVT) method, utilizing single-walled carbon nanotubes (SWCNTs) with 1D cavities as templates, and high-quality and high-efficiency fabrication of 1D atomic chains of CrCl3 was achieved. Furthermore, the structure of CrCl3 atomic chains in the confined space of SWCNTs was analyzed in detail, and the charge transfer between the 1D atomic chains and SWCNTs was investigated through spectroscopic characterization. A comprehensive study of the dynamic magnetic properties revealed the existence of spin glass states and freezing of the 1D CrCl3 atomic chains at around 3 K, which has never been seen in bulk CrCl3. Our work established an effective strategy for the control synthesis of 1D magnetic atomic chains with promising potential applications in further magnetic-based spintronics devices.

Beta thalassemia trait with priapism A unique presentation

Beta thalassemias are characterized by decreased to absent beta globin chain synthesis. These are autosomal recessive disorders caused commonly due to point mutations in the beta globin gene on chromosome 11.

Synthesis of the C28-C41 Side Chain of (Proposed) Neaumycin B: AContiguous Stereohextet.

The C28-C41 side-chain of the proposed structure of neaumycin B, which encompasses a contiguous stereohextet, is prepared in 8 steps (longest linear sequence). Convergency is maximized via Williams' Felkin-Anh-selective triorganozincate-mediated vinylation of an α,β-stereogenic aldehyde. The relative stereochemical assignment of the C33-C35 stereotriad was accomplished via the 13C NMR analysis of the related acetonide. Relative stereochemistry of C33 carbinol and C36-C37 glycidol was determined by comparative NOE analysis of the related diastereomeric furans.

Measurement of Erythrocyte Lifespan Using a CO Breath Test in Patients with Thalassemia and the Impact of Treatment.

Background: Thalassemia comprises a diverse group of genetic disorders that affects the synthesis of globin chains, with a global distribution. The use of erythrocyte lifespan (ELS) to assess differences among patients with different types of thalassemia and the efficacy of splenectomy has not been implemented.

Efficacy and safety evaluation of Azvudine in the prospective treatment of COVID-19 based on four phase III clinical trials.

Azvudine (FNC) is a synthetic nucleoside analog used to treat adult patients living with human immunodeficiency virus-1 (HIV-1) infection with high viral load. After phosphorylation, Azvudine inhibits RNA-dependent RNA polymerase, leading to the discontinuation of RNA chain synthesis in viruses. In addition, Azvudine is the first dual-target nucleoside oral drug worldwide to simultaneously target reverse transcriptase and viral infectivity factors in the treatment of HIV infection. On 9 August 2022, Azvudine was incorporated into the Guidelines for the Diagnosis and Treatment of Coronavirus Disease 2019 (version ninth) issued by the National Health Commission and the National Administration of Traditional Chinese Medicine. The recommended oral dose of Azvudine for the treatment of moderate coronavirus disease 2019 (COVID-19) is 5mg once daily, and the duration of Azvudine treatment should not exceed 14days. Four phase III clinical trials were performed during 2020-2022 to evaluate the efficacy and safety of Azvudine in the treatment of COVID-19. The results revealed that Azvudine could reduce nucleic acid-negative conversion time, viral load, and time to improvement in clinical conditions in patients with moderate COVID-19. In addition, Azvudine exhibited good safety and tolerance. Thereafter, Azvudine was incorporated into the Chinese guidelines and expert consensus for the treatment of COVID-19 and was highly approbated. Furthermore, Azvudine was also included in the Chinese guidelines for HIV infection.

Growth of Enterococcus faecalis ∆plsX strains is restored by increased saturated fatty acid synthesis.

The Enterococcus faecalis acyl-acyl carrier protein (ACP) phosphate acyltransferase PlsX plays an important role in phospholipid synthesis and exogenous fatty acid incorporation. Loss of plsX almost completely blocks growth by decreasing de novo phospholipid synthesis, which leads to abnormally long-chain acyl chains in the cell membrane phospholipids. The ∆plsX strain failed to grow without supplementation with an appropriate exogenous fatty acid. Introduction of a ∆fabT mutation into the ∆plsX strain to increase fatty acid synthesis allowed very weak growth. The ∆plsX strain accumulated suppressor mutants. One of these encoded a truncated β-ketoacyl-ACP synthase II (FabO) which restored normal growth and restored de novo phospholipid acyl chain synthesis by increasing saturated acyl-ACP synthesis. Saturated acyl-ACPs are cleaved by a thioesterase to provide free fatty acids for conversion to acyl-phosphates by the FakAB system. The acyl-phosphates are incorporated into position sn1 of the phospholipids by PlsY. We report the tesE gene encodes a thioesterase that can provide free fatty acids. However, we were unable to delete the chromosomal tesE gene to confirm that it is the responsible enzyme. TesE readily cleaves unsaturated acyl-ACPs, whereas saturated acyl-ACPs are cleaved much more slowly. Overexpression of an E. faecalis enoyl-ACP reductase either FabK or FabI which results in high levels of saturated fatty acid synthesis also restored the growth of the ∆plsX strain. The ∆plsX strain grew faster in the presence of palmitic acid than in the presence of oleic acid with improvement in phospholipid acyl chain synthesis. Positional analysis of the acyl chain distribution in the phospholipids showed that saturated acyl chains dominate the sn1-position indicating a preference for saturated fatty acids at this position. High-level production of saturated acyl-ACPs is required to offset the marked preference of the TesE thioesterase for unsaturated acyl-ACPs and allow the initiation of phospholipid synthesis.