Novel missense mutation c.797T>C (p.Met266Thr) gives rise to the rare B(A) phenotype in a Chinese family.

BACKGROUND AND OBJECTIVES: B(A) phenotype is usually formed by nucleotide mutations in the ABO*B.01 allele, with their products exhibiting glycosyltransferases (GTs) A and B overlapping functionality. We herein report a B(A) allele found in a Chinese family. MATERIALS AND METHODS: The entire ABO genes of the probands, including flanking regulatory regions, were sequenced through PacBio third-generation long-read single-molecule real-time sequencing. 3D molecular models of the wild-type and mutant GTB were generated using the DynaMut web server. The effect of the mutation on the enzyme function was predicted by PROVEAN and PolyPhen2. The predictions of stability changes were performed using DynaMut and SNPeffect. RESULTS: Based on serological and sequencing features, we concluded the two probands as possible cases of the B(A) phenotype. Crystallization analysis showed that Thr266 substitution does not disrupt the hydrogen bonds. However, some changes in interatomic contacts, such as loss of ionic interactions and hydrophobic contacts, and addition of weak hydrogen bonds, may have affected protein stability to some extent. This mutation was predicted to have a benign effect on enzyme function and slightly reduce protein stability. CONCLUSION: The probands had the same novel B(A) allele with a c.797T>C (p.Met266Thr) mutation on the ABO*B.01 backbone.

[Cardiovascular and Cerebrovascular Diseases Induced by Air Pollution].

Air pollution has severe detrimental effects on public health.A substantial number of studies have demonstrated that air pollution exposure is a risk factor for the occurrence of cardiovascular and cerebrovascular diseases and a cause of non-communicable diseases.Both long-term and short-term exposure to air pollution are associated with respiratory diseases,stroke,coronary artery disease,and diabetes.Aiming to better understand the association,we reviewed the latest studies about the association of air pollution with cardiovascular and cerebrovascular diseases,especially stroke,coronary heart disease,arrhythmia,hypertension,and heart failure,and summarized the underlying mechanisms of the health damage caused by long-term and short-term exposure to air pollution.

[Cardiac Protection Mechanism and Clinical Application of Dexmedetomidine].

Dexmedetomidine is an α2 adrenoceptor agonist and has cardioprotective effect,the mechanism of which is being studied.Increasing studies have proved the clinical value of dexmedetomidine in reducing postoperative complications and improving the prognosis of patients.Therefore,this review summarizes the cardiac protection mechanism of dexmedetomidine based on the existing studies and expounds the application of dexmedetomidine in the perioperative period of cardiovascular surgery.

The spectrum and prevalence of arrhythmia in different clinical pulmonary hypertension groups in Chinese population.

BACKGROUND: Arrhythmia is not uncommon among pulmonary hypertension (PH) population, and may be associated with disease severity. HYPOTHESIS: To investigate different spectrums and prevalence of arrhythmias in different clinical PH groups in Chinese population. METHODS: Patients diagnosed with PH between April 15, 2019, and August 2, 2021, were enrolled prospectively. The prevalence of different types of arrhythmias in PH patients were calculated. Logistic regression analyses were conducted to determine independent predictors for arrhythmia. RESULTS: One thousand patients were enrolled. The prevalence of any arrhythmia, sinus node dysfunction, sinus tachycardia, atrial fibrillation, atrial flutter, other types of atrial tachycardia, atrioventricular block, and ventricular tachycardia is 44.4%, 12.2%, 15.2%, 8.1%, 4.1%, 10.2%, 7.1%, and 2.5%. Logistic regression analyses revealed that older age and larger right ventricle (odds ratio: 1.111 and 1.095, p < .05) were independently related with higher probability of supraventricular arrhythmia; Complicating with coronary artery disease, larger right ventricle, and increased left ventricular end-diastolic diameter (odds ratio: 19.540, 1.106, and 1.085, p < .05) were independently correlated with sinus node dysfunction/atrioventricular block in patients with pulmonary arterial hypertension. CONCLUSIONS: Nearly half of PH patients experienced at least one type of arrhythmia. The most common seen arrhythmias were supraventricular arrhythmia, sinus tachycardia, and sinus node dysfunction. Older age and larger right ventricle were independently related with higher probability of supraventricular arrhythmia; Complicating with coronary artery disease, larger right ventricle and increased left ventricular end-diastolic diameter were independently correlated with higher probability of sinus node dysfunction/atrioventricular block in patients with pulmonary arterial hypertension.

[Progress in Anticoagulation of Calf Muscle Venous Thrombosis].

With the wide application of vascular Doppler ultrasound as well as the improvement of instrument precision and personnel operation practice,calf muscular venous thrombosis(CMVT)has been more and more frequently diagnosed among patients,becoming a common clinical disease.However,it is controversial about the anticoagulant therapy for CMVT patients.In this article,we summarize the current research progress of anticoagulation therapy,aiming to provide reference for the treatment of CMVT.

[Value of Non-invasive Electrocardiologic Examination in Prediction of Sudden Cardiac Death].

Sudden cardiac death(SCD),a serious public health problem facing China and the world,causes heavy social burden.It is reported that SCD accounts for 15%-20% of all the deaths and the proportion of SCD patients with non-cardiac disease is as high as 50%.Finding effective predictors to identify SCD early is particularly important for clinical practice.To date,non-invasive electrocardiologic examination has been the first choice for predicting the risks of fatal ventricular arrhythmias and SCD because of its safety and feasibility.This review summarizes the available relevant studies to expound the value of non-invasive electrocardiologic examination and indicators in predicting SCD.

The chromatin modification by SUMO-2/3 but not SUMO-1 prevents the epigenetic activation of key immune-related genes during Kaposi's sarcoma associated herpesvirus reactivation.

BACKGROUND: SUMOylation, as part of the epigenetic regulation of transcription, has been intensively studied in lower eukaryotes that contain only a single SUMO protein; however, the functions of SUMOylation during mammalian epigenetic transcriptional regulation are largely uncharacterized. Mammals express three major SUMO paralogues: SUMO-1, SUMO-2, and SUMO-3 (normally referred to as SUMO-1 and SUMO-2/3). Herpesviruses, including Kaposi's sarcoma associated herpesvirus (KSHV), seem to have evolved mechanisms that directly or indirectly modulate the SUMO machinery in order to evade host immune surveillance, thus advancing their survival. Interestingly, KSHV encodes a SUMO E3 ligase, K-bZIP, with specificity toward SUMO-2/3 and is an excellent model for investigating the global functional differences between SUMO paralogues. RESULTS: We investigated the effect of experimental herpesvirus reactivation in a KSHV infected B lymphoma cell line on genomic SUMO-1 and SUMO-2/3 binding profiles together with the potential role of chromatin SUMOylation in transcription regulation. This was carried out via high-throughput sequencing analysis. Interestingly, chromatin immunoprecipitation sequencing (ChIP-seq) experiments showed that KSHV reactivation is accompanied by a significant increase in SUMO-2/3 modification around promoter regions, but SUMO-1 enrichment was absent. Expression profiling revealed that the SUMO-2/3 targeted genes are primarily highly transcribed genes that show no expression changes during viral reactivation. Gene ontology analysis further showed that these genes are involved in cellular immune responses and cytokine signaling. High-throughput annotation of SUMO occupancy of transcription factor binding sites (TFBS) pinpointed the presence of three master regulators of immune responses, IRF-1, IRF-2, and IRF-7, as potential SUMO-2/3 targeted transcriptional factors after KSHV reactivation. CONCLUSION: Our study is the first to identify differential genome-wide SUMO modifications between SUMO paralogues during herpesvirus reactivation. Our findings indicate that SUMO-2/3 modification near protein-coding gene promoters occurs in order to maintain host immune-related gene unaltered during viral reactivation.

¹H NMR study of monocrotaline and its metabolites in human blood.

Monocrotaline (MCT) is a naturally occurring hepatotoxic pyrrolizidine alkaloid found in plants. This investigation is aimed at furthering the understanding of the role of blood in mediating the transport of MCT and its reactive metabolites in humans. Reactions of monocrotaline and its metabolites, dehydromonocrotaline (DHM), retronecine (RET) and dehydroretronecine (DHR) with human blood plasma, red blood cells (RBCs), and whole blood were studied in vitro by proton nuclear magnetic resonance spectroscopy. In plasma MCT remained intact and weakly associated with plasma proteins, and DHM was rapidly hydrolyzed releasing necic and lactone acids, and the reactive pyrrolic metabolite. MCT and its metabolite DHM were internalized in RBCs to the extent of 46.0% and 48.9% respectively in 30 min. No polymerization of DHR was observed when incubated with plasma and RBCs. The data clearly showed that both human plasma and RBCs could be the carriers for the transportation of MCT and its metabolites, DHM, RET and DHR between organs and could stabilise the reactive MCT metabolite DHR.

A novel fast disintegrating tablet fabricated by three-dimensional printing.

BACKGROUND: Based on computer-aided models, three-dimensional printing (3DP) technology can exercise local control over the material composition, microstructure, and surface texture during it layer-by-layer manufacturing process to endow the products with special properties. It can be a useful tool in the development of novel solid dosage forms. METHOD: In this study, a novel fast disintegrating tablet (FDT) with loose powders in it was designed and fabricated using 3DP process. The inner powder regions were formed automatically by depositing the binder solutions onto selected regions during the layer-printing processes. RESULTS: Environmental scanning electron microscope images clearly showed that the printed regions were bound together. The particle size was reduced or individual particles could no longer be distinguished. In contrast, the unprinted regions were uncompacted with cracks and fissures among the loose powders. The tablets had a hardness value of 54.5 N/cm(2) and 0.92% mass loss during the friability tests. The disintegration time of the tablets was 21.8 seconds and the wetting time was 51.7 seconds. The in vitro dissolution tests showed that 97.7% acetaminophen was released in the initial 2 min. CONCLUSION: 3DP process is able to offer novel methods for preparing FDTs.