Site-specific MCM sumoylation prevents genome rearrangements by controlling origin-bound MCM

Timely completion of eukaryotic genome duplication requires coordinated DNA replication initiation at multiple origins. Replication begins with the loading of the Mini-Chromosome Maintenance (MCM) complex, proceeds by the activation of the Cdc45-MCM-GINS (CMG) helicase, and ends with CMG removal after chromosomes are fully replicated. Post-translational modifications on the MCM and associated factors ensure an orderly transit of these steps. Although the mechanisms of CMG activation and removal are partially understood, regulated MCM loading is not, leaving an incomplete understanding of how DNA replication begins. Here we describe a site-specific modification of Mcm3 by the Small Ubiquitin-like MOdifier (SUMO). Mutations that prevent this modification reduce the MCM loaded at replication origins and lower CMG levels, resulting in impaired cell growth, delayed chromosomal replication, and the accumulation of gross chromosomal rearrangements (GCRs). These findings demonstrate the existence of a SUMO-dependent regulation of origin-bound MCM and show that this pathway is needed to prevent genome rearrangements.

Faithful replication of the genome is essential for the survival and health of all living organisms. The eukaryotic genome presents a unique and difficult challenge: its enormous size demands the coordinated action of numerous DNA replication origins to ensure timely completion of genome duplication. Although the mechanisms that control the activation and removal of DNA replisome are partially understood, whether and how cells regulate the loading of the Mini-Chromosome Maintenance (MCM) complex, the precursor of the DNA replisome, at replication origins are not. Because mutations to MCM-loading factors and enzymes that catalyze reversible protein sumoylation cause substantial gross chromosomal rearrangements (GCRs) that characterize the cancer genome, understanding regulated MCM loading is one of the most pressing questions in the field. Here, we identified a site-specific SUMO modification of MCM and found that mutation disabling this modification causes severe growth defect and impaired DNA replication. These defects are attributable to reduced MCM at DNA replication origins, resulting in a lower DNA replisome level and a dramatic accumulation of GCRs. Thus, these findings identify a hitherto unknown regulatory mechanism: Site-specific MCM sumoylation regulates origin-bound MCM, and this prevents genome rearrangements.

High efficiency and collimated terahertz pulse from ultra-short intense laser and cone target

We propose a new, to the best of our knowledge, method to radiate a high-efficiency and collimated terahertz (THz) pulse from a relativistic femtosecond laser and cone target. Particle-in-cell simulations demonstrate that a THz source of 40 mJ, pointing at an angle of ∼20 ^∘, can be generated from a laser pulse of 1.9 J by using a cone target whose open angle is 10 ^∘. The peak power of the THz pulse is 10¹¹ W. This method, which manipulates the divergence angle and the energy conversion efficiency of the THz source, should promote THz science into the extra strong region with a compact laser system.

Clinical study of sodium bicarbonated Ringer's solution on fluid resuscitation of patients with hemorrhagic shock

OBJECTIVE

Fluid resuscitation is a crucial step in shock treatment, but the choice of crystal solution remains controversial. Sodium bicarbonated Ringer's solution can not only effectively expand blood volume, but also reduce tissue damage and acidosis. The study aims to evaluate the resuscitation effect of sodium bicarbonated Ringer's solution on patients with hemorrhagic shock.

PATIENTS AND METHODS

A total of 96 patients with hemorrhagic shock were randomly assigned to receive either normal saline solution (control group) or sodium bicarbonated Ringer's solution (experimental group). The changes in blood lactate, heart rate, arterial pH and mean arterial pressure (MAP) were measured at different time points. The 28-day survival rate, the incidence of complications, and the average length of hospital stay were recorded. Simult RESULTS: The heart rate, blood lactate, sodium, and chloride in the experimental group were significantly lower than those in the control group, while the MAP, potential of hydrogen (pH), bicarbonate, and base excess in the experimental group were significantly higher than those in the control group at every observed time point after resuscitation (p<0.05). Compared with the control group, the experimental group had a lower incidence of acute respiratory distress syndrome (ARDS) (8.3% vs. 22.9%, p<0.05), shorter mechanical ventilation time (2.2 vs. 3.5, p<0.05), and shorter intensive care unit length of stay (3.8 vs. 4.1, p<0.05). The 28-day survival rate between the two groups showed no significant differences (p>0.05).

CONCLUSIONS

Early resuscitation with sodium bicarbonated Ringer's solution could better maintain acid-base balance and hemodynamic stability and reduce the risk of related complications.

Transcriptomic analysis of spleen B cell revealed the molecular basis of bursopentin on B cell differentiation

The bursa of Fabricius, the acknowledged humoral immune organ unique to birds, plays a vital role in B cell development. Bursopentin (BP5) derived from the bursa is reported to induce the development and formation of B cells. However, the mechanism of BP5 on B cell differentiation is still unclear. In this paper, total B lymphocytes from mice immunized with H9N2 subtype AIV vaccine were stimulated with BP5. The results show that BP5 at the experimental dosages promoted B cell differentiation, including the total B cells, activated B cells, differentiated B cells, mature B cells and plasma cells. Then, the in vivo immune experiment proved that the percentages of activated and differentiated B cells from mice immunized with AIV vaccine and 0.25 mg/mL BP5 were increased. To investigate the molecular mechanism of BP5 on B cell differentiation, the gene expression profiles of B cells purified from the spleen cells of mice immunized with AIV vaccine and BP5 were detected following RNA sequencing technology. The results show that BP5 at 0.05 and 0.25 mg/mL induced the enrichment of various biological functions, and stimulated five common significant enrichment pathways in B cells from the immunized mice. Additionally, 120 and 59 differentially expressed genes (DEG) represented transcriptional factors in B cells following 0.05 and 0.25 mg/mL BP5 immunization, respectively. In summary, these results suggest that BP5 regulates various gene expression involved in regulation of B cell development, which provides the knowledge required for additional studies on B cell differentiation in response to bursal-derived peptides and also provides an important experimental basis for improving vaccine immunity.

Development and internal validation of a diagnostic prediction model for COVID-19 at time of admission to hospital

BACKGROUND

Early coronavirus disease 2019 (COVID-19) diagnosis prior to laboratory testing results is crucial for infection control in hospitals. Models exist predicting COVID-19 diagnosis, but significant concerns exist regarding methodology and generalizability.

AIM

To generate the first COVID-19 diagnosis risk score for use at the time of hospital admission using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) checklist.

DESIGN

A multivariable diagnostic prediction model for COVID-19 using the TRIPOD checklist applied to a large single-centre retrospective observational study of patients with suspected COVID-19.

METHODS

581 individuals were admitted with suspected COVID-19; the majority had laboratory-confirmed COVID-19 (420/581, 72.2%). Retrospective collection was performed of electronic clinical records and pathology data.

RESULTS

The final multivariable model demonstrated AUC 0.8535 (95% confidence interval 0.8121-0.8950). The final model used six clinical variables that are routinely available in most low and high-resource settings. Using a cut-off of 2, the derived risk score has a sensitivity of 78.1% and specificity of 86.8%. At COVID-19 prevalence of 10% the model has a negative predictive value (NPV) of 96.5%.

CONCLUSIONS

Our risk score is intended for diagnosis of COVID-19 in individuals admitted to hospital with suspected COVID-19. The score is the first developed for COVID-19 diagnosis using the TRIPOD checklist. It may be effective as a tool to rule out COVID-19 and function at different pandemic phases of variable COVID-19 prevalence. The simple score could be used by any healthcare worker to support hospital infection control prior to laboratory testing results.

Treatment of oil-based drilling cuttings using the demulsification separation-Fenton oxidation method

In this study, demulsification separation-Fenton oxidation technology was employed as a combined technology to treat total petroleum hydrocarbons (TPH) in oil-based drill cuttings (OBDC). Batch experiments were carried out to optimize the technology parameter. Under the optimal condition, 70% and 51% TPH removal rate was obtained for demulsification technology and Fenton oxidation technology, respectively. Eighty-five percent of TPH removal rate was obtained using combination technology of demulsification separation and Fenton oxidation. Multiple characterizations were used to analyze the physical and chemical properties of treated OBDC. The result of XRD pattern indicated the combination technology had no obvious effect for structure phase of OBDC. The results of FTIR, GC-MS, TG-DTG and SEM were used to characterize the treated OBDC. This paper provides an efficient and feasible combined technology for OBDC treatment, which expands a new strategy for the removal of TPH from solid waste.

Introduction to DOK2 and its potential role in cancer

Cancer is a complex, multifactorial disease that modern medicine ultimately aims to overcome. Downstream of tyrosine kinase 2 (DOK2) is a well-known tumor suppressor gene, and a member of the downstream protein DOK family of tyrosine kinases. Through a search of original literature indexed in PubMed and other databases, the present review aims to extricate the mechanisms by which DOK2 acts on cancer, thereby identifying more reliable and effective therapeutic targets to promote enhanced methods of cancer prevention and treatment. The review focuses on the role of DOK2 in multiple tumor types in the lungs, intestines, liver, and breast. Additionally, we discuss the potential mechanisms of action of DOK2 and the downstream consequences via the Ras/MPAK/ERK or PI3K/AKT/mTOR signaling pathways.

Oxidation Characteristics of Water Soluble Fractions of Agro-Stalks with Focus on Function of Reactive Inorganics

In order to deepen the understanding of the thermochemical behavior of reactive inorganics, which play an important role in slagging and fouling during combustion of agro-stalks, the oxidation behavior of the water-soluble fraction of corn stover, wheat straw and rice straw was examined using a simultaneous thermogravimetric analyzer. The oxidation characteristics were discussed in combination with elemental analysis of water-soluble fractions. Results showed that reactive inorganics elements account for 30–40% in water-soluble fractions of the three agro-stalks and carbon was oxidized at two separate stages. Four stages were found during oxidation of water-soluble fractions – (1) devolatilisation of organics (100‒400 °C); (2) oxidation of char (400–650 °C); (3) oxidation of char with melting of salts or decomposition of carbonate (650–800 °C); (4) vaporization of KCl (800–1000 °C). This work provides a base study for an optimized design of combustion for agro-stalks and pharmaceutical waste.

[Research Progress on the Effect of Synthetic Cathinones on Animal Behavior]

Abstract

Synthetic cathinones are a class of new psychoactive substances with a structure similar to amphetamine drugs, which can produce excitatory effects similar to drugs such as amphetamine and cocaine after being taken. In recent years, the abuse of synthetic cathinones worldwide has become increasingly serious, posing a serious threat to social security and public health. This article focuses on several common synthetic cathinones, collects their research results in animal autonomous activity experiments and drug dependence model experiments and summarizes their relevant experimental conclusions in animal body temperature regulation, learning and memory, and anxiety, in order to provide data reference and method guidance for the domestic development of related drug research.

Identification of BRAF p. V600E-Mutant and Wild-Type by MR Imaging in Pleomorphic Xanthoastrocytoma and Anaplastic Pleomorphic Xanthoastrocytoma

BACKGROUND AND PURPOSE

Compared with BRAF p. V600E wild-type pleomorphic xanthoastrocytoma, BRAF p. V600E-mutant pleomorphic xanthoastrocytoma showed a higher survival rate. In this study, we focused on finding preoperative MR imaging differences between BRAF p. V600E mutant and wild-type in pleomorphic xanthoastrocytoma and anaplastic pleomorphic xanthoastrocytoma.

MATERIALS AND METHODS

Twenty-three patients with pathologically confirmed pleomorphic xanthoastrocytoma or anaplastic pleomorphic xanthoastrocytoma in our hospital were retrospectively analyzed from January 2015 to December 2020. They were divided into a BRAF p. V600E-mutant group (including 6 pleomorphic xanthoastrocytomas and 5 anaplastic pleomorphic xanthoastrocytomas) and a wild-type group (including 8 pleomorphic xanthoastrocytomas and 4 anaplastic pleomorphic xanthoastrocytomas). The preoperative MR imaging characteristics of these groups were statistically compared.

RESULTS

The wild-type pleomorphic xanthoastrocytoma group presented with more aggressive conventional and advanced MR imaging features than the mutant pleomorphic xanthoastrocytoma group, including greater mean maximum tumor diameter (3.1 [SD, 0.9] cm versus 1.7 [SD, 0.4 ] cm, P < .05), more frequent heterogeneous contrast enhancement of solid portions (100% versus 0%, P < .001), more obvious peritumoral edema (mean, [2.1 SD, 0.7] cm versus 0.6 [SD, 0.2] cm, P < .01), and lower mean minimum relative ADC (896 [SD, 86] versus 988 [SD, 73], P < .05) and mean relative ADC (1060 [SD, 159] versus 1248 [SD, 116], P < .05) on DWI. However, there was no significant difference in either conventional or advanced MR imaging features between the wild-type anaplastic pleomorphic xanthoastrocytoma group and the mutant anaplastic pleomorphic xanthoastrocytoma group.

CONCLUSIONS

Neurosurgeons should carefully interpret MR images before an operation and select appropriate surgical strategies according to genotype prediction.

[Analysis of prescription and rationality of anti-hypertensive medication among community health centers in Beijing]

Objective: Explore the usage of anti-hypertension drugs and the rationality of hypertension prescription among the primary health centers in Dongcheng District, Beijing. Method: This cross-sectional and retrospective study was applied to analyze the hypertension prescriptions from the 8 community health centers in Dongcheng District. The anatomical, therapeutic and chemical classification (ATC) codes were used to determine the drug category. ATC information was used to filter data containing antihypertensive drugs, and group the number and proportion of ATC categories. The type of drug was judged by its generic name. According to the diagnosis information in the prescription, the prescription containing the Western medicine diagnosis of hypertension was screened out. The comorbidities of hypertension in the study included 7 types of diseases including diabetes, chronic kidney disease, coronary heart disease, heart failure, atrial fibrillation, stroke, and dyslipidemia. The analysis of prescription rationality included rationality of combination medication, rationality of drug dosage and rationality of drug price. The agreed daily dose (DDD) method was used to analyze the rationality of drug dosage. The drug utilization index (DUI) was used as a quantitative indicator to estimate the rationality of medication, and overdose was expressed by DUI>1. The reasonableness of the drug price was judged based on the price of the drug and whether it was a drug in the "4+7" plan. Results: A total of 658 140 prescriptions were extracted as the final data set, involving 7 categories and 60 commonly used anti-hypertensive drugs, and the corresponding cost of medication was ￥96.58 million. Drugs were prescribed according to comorbidities, and the choice followed the international guidelines. Calcium channel blockers (CCB) were the most prescribed drugs in the prescriptions of patients with comorbidities, and α-adrenergic receptor antagonists were the least prescribed drugs. The proportion of diuretics prescribed in hypertensive patients complicating with heart failure was 21.17% (505/2 385), which was much higher than that of patients complicating with other comorbidities (P<0.05). The proportion of diuretics prescribed in hypertension patients complicating with dyslipidemia was lower than that of patients with other comorbidities (2 639 (0.94%), P<0.05), and β-blockers (BB) or angiotensin Ⅱreceptor blockers (ARB) were more likely to be selected (BB: 59 348 (21.08%), ARB: 51 356 (18.24%))in these patients. The proportion of BB in prescriptions for hypertension patients with chronic kidney disease was lower than that of patients with other comorbidities (P<0.05). The proportion of BB in prescriptions for hypertension patients with coronary heart disease was higher than that of other comorbidities (P<0.05). Hypertension patients with atrial fibrillation or stroke accounted for a higher proportion of CCB prescriptions (P<0.05). Single antihypertensive drug prescriptions accounted for the highest proportion, 61.19% (402 745/658 140). Two-combination prescriptions accounted for the highest proportion of combination prescriptions, 72.19% (184 392/255 395). CCB based two-combination prescriptions accounted for the highest proportion, 122 350(66.36%). ARB-based tri-combination prescriptions accounted for the highest proportion, 48 915(89.50%),followed by CCB based tri-combination prescriptions (44 732(81.85%)).There were 2 174 (0.33%) prescriptions with unreasonable combination therapies and DUI>1 were found in 48 out of 60 commonly used drugs. In all possible antihypertensive drugs, only 40.92% (109 227/266 993)followed the "4+7" plan. Conclusions: The anti-hypertensive agents from these prescriptions in the primary health centers are diverse, and the choice is generally complied with the guidelines, but some unreasonable situations existed, especially on the combined anti-hypertensive medication, overdose, and"4+7"plan is not followed completely.

Suboptimal blood pressure control and associated risk for cardiovascular mortality among stroke survivors in China

Background

Elevated blood pressure (BP) is associated with substantial morbidity and mortality in stroke survivors. China has approximately 7.5 million stroke survivors, and accounts for one third of stroke mortality worldwide, but little is known about the prevalence and management of elevated BP as well as its effect on cardiovascular death at the national level.

Purpose

We aim to describe the prevalence and treatment of elevated BP and assess the cardiovascular mortality attributable to elevated BP among stroke survivors in China.

Methods

Based on 3 million participants aged 35–75 years from all 31 provinces in mainland China recruited from September 2014 through August 2019, we assessed the prevalence and treatment of elevated BP (systolic BP ≥140mmHg or diastolic BP ≥90mmHg) among those with self-reported stroke. Cardiovascular death was recorded before December 31st 2019. The age- and sex- specific population attributable fractions of cardiovascular death from elevated BP were estimated based on hazard ratios derived by Cox regression analysis.

Results

Among 91,628 stroke survivors, the mean (SD) age was 62 (8) years, 49% were male sex. The median (IQR) stroke duration was 4 (2,7) years. 61.3% of the individuals had elevated BP, and the prevalence increased with age (from 47.6% at 35–44 years of age to 64.7% at 65–75 years of age) and was slightly higher in rural area (63.2%) than urban area (58.8%). 32.7% of the overall population were treated, and 23.4% of those with elevated BP were treated. Among stroke survivors, elevated BP accounted for 26% of cardiovascular death at 35–75 years of age, and about one third at 35–54 years of age. The age- and sex- specific results were shown in the Table.

Conclusions

In this nationwide cohort of stroke survivors from China, over 60% had elevated BP, and about one third were treated. Elevated BP was associated with particularly substantial cardiovascular mortality for young and middle-aged stroke survivors. National strategies targeting elevated BP are required to improve the prognosis of stroke survivors in China.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Key Research and Development Program from the Ministry of Science and Technology of China Age- and sex-specific HRs and PAFs

Using Proanthocyanidin as a Root Dentin Conditioner for GIC Restorations

Glass ionomer cements (GICs) are considered the material of choice for restoration of root carious lesions (RCLs). When bonding to demineralized dentin, the collapse of dentinal collagen during restorative treatment may pose challenges. Considering its acidic nature and collagen biomodification effects, proanthocyanidin (PAC) could be potentially used as a dentin conditioner to remove the smear layer while simultaneously acting to biomodify the dentinal collagen involved in the bonding interface. In this study, 6.5% w/v PAC was used as a conditioner for sound (SD) and laboratory demineralized (DD) root dentin before bonding to resin-modified GIC (FII), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified GIC (FVII), or a high-viscosity GIC (FIX). Root dentin conditioned with deionized distilled water (DDW) or polyacrylic acid (PAA) served as controls. Results indicated FII showed higher shear bond strength (SBS) on SD than the other 2 GICs, especially in PAA-conditioned samples; FIX showed significantly higher SBS than FII and FVII on PAA- or PAC-conditioned DD. In each category of GIC, PAA and PAC did not have a significant influence on SBS in most cases compared to DDW except for a significant decrease in PAC-conditioned SD bonded to FII and a significant increase in PAA-conditioned DD bonded to FIX. The bonding interface between GIC and SD was generally more resistant to the acid-base challenge than DD. Although the alterations in failure modes indicated a compromised interfacial interaction between GICs and PAC-treated root dentin, biomodification effects of PAC on dentin were observed from Raman microspectroscopy analysis in terms of the changes in mineral-to-matrix ratio and hydroxyproline-to-proline ratio of dentin adjacent to the bonding interface, especially of DD. Results from this study also indicated the possibility of using in situ characterization such as Raman microspectroscopy as a complementary approach to SBS test to investigate the integrity of the bonding interface.

[Trend analysis on morbidity and mortality of pancreatic cancer in China, 2005-2015]

Objective: To analyze the trend of morbidity and mortality of pancreatic cancer in China from 2005 to 2015 and estimate the related age, period and cohort effect, respectively. Methods: Joinpoint regression analysis was used to analyze the trend of morbidity rate and mortality rate of pancreatic cancer during 2005-2015 and calculate the annual percentage change and average annual percentage change based on the data in the annual report of China Cancer Registry. Population aged 20-84 years was fitted by the Age-Period-Cohort model to estimate the effect parameters of age, period and cohort. Results: The trend variations of the crude morbidity rate and crude mortality rate of pancreatic cancer were consistent. The morbidity rate of pancreatic cancer firstly increased before 2008 and then decreased. The morbidity rate and mortality rate of pancreatic cancer were higher in men than women, and higher in urban areas than in rural areas. From 2005 to 2015, the overall age-standardized morbidity rate of pancreatic cancer increased by 2.78% annually and the overall age standardized mortality rate of pancreatic cancer increased by 2.24% annually. The age standardized morbidity of pancreatic cancer in rural men changed more rapidly, with an average annual increase of 3.74%, and the age standardized mortality rate of pancreatic cancer in urban men changed more rapidly, with an average annual increase of 3.57%. The age effect on the morbidity and mortality of pancreatic cancer increased with age, and the effect was most obvious in age group 70-80 years, the period effect increased over time and the cohort effect decreased with year, but rebound or fluctuation was observed after 1976. Conclusions: The morbidity rate and mortality rate of pancreatic cancer in China increased slightly in past decades. Strategies on effective prevention and control of pancreatic cancer should be developed in the future.

Comparison of the effects of short-term feeding of sodium acetate and sodium bicarbonate on milk fat production

Supplementation with sodium acetate (NaAcet) increases milk fat production through an apparent stimulation of de novo lipogenesis in the mammary gland. Sodium acetate increases acetate supply to the mammary gland, but it also increases dietary cation-anion difference, which can also increase milk fat yield. The objective of this study was to determine if the effect of NaAcet on milk fat production was due to an increase in acetate supply or an increase in dietary cation-anion difference. The study included 12 multiparous cows in a replicated 3 × 3 Latin square design balanced for carryover effects, with 14-d experimental periods. Treatments were a basal total mixed ration (31.8% neutral detergent fiber, 14.8% crude protein, 25.5% starch, and 4.4% fatty acids on a dry matter basis) as a no-supplement control, acetate supplemented at 3.25% of dry matter as NaAcet, and sodium bicarbonate (NaHCO₃) providing an equal amount of sodium to the NaAcet treatment. The NaAcet and NaHCO₃ were mixed into the basal diet before feeding. Milk samples were taken at each milking during the last 3 d of each period. Plasma samples were taken every 9 h during the last 3 d (a total of 8 times) to determine concentrations of plasma metabolites and hormones. Eating behavior was monitored during the last week of each period using an automated system. The NaAcet and NaHCO₃ treatments increased milk fat concentration and yield compared to the no-supplement control. The NaAcet treatment increased milk fat production predominantly by increasing the yield of de novo and mixed-source fatty acids. The NaHCO₃ treatment increased the yield of preformed and de novo fatty acids, suggesting different mechanisms for the 2 treatments. The NaAcet treatment increased plasma acetate concentration in a period of the day concurrent with the highest dry matter intake. The NaAcet treatment increased milk fat production by stimulating the production of de novo fatty acids, a mechanism consistent with previous reports, possibly by increasing acetate supply to the mammary gland. The NaHCO₃ treatment increased milk fat production by increasing the production of all biological categories of fatty acids, except for odd and branched-chain fatty acids, possibly by increasing overall diet digestibility.