The application of PROTAC in HDAC.

Inducing protein degradation by proteolysis targeting chimera (PROTAC) has provided great opportunities for scientific research and industrial applications. Histone deacetylase (HDAC)-PROTAC has been widely developed since the first report of its ability to induce the degradation of SIRT2 in 2017. To date, ten of the eighteen HDACs (HDACs 1-8, HDAC10, and SIRT2) have been successfully targeted and degraded by HDAC-PROTACs. HDAC-PROTACs surpass traditional HDAC inhibitors in many aspects, such as higher selectivity, more potent antiproliferative activity, and the ability to disrupt the enzyme-independent functions of a multifunctional protein and overcome drug resistance. Rationally designing HDAC-PROTACs is a main challenge in development because slight variations in chemical structure can lead to drastic effects on the efficiency and selectivity of the degradation. In the future, HDAC-PROTACs can potentially be involved in clinical research with the support of the increased amount of in vivo data, pharmacokinetic evaluation, and pharmacological studies.

Molecular Epidemiology of Community-Acquired Methicillin-Resistant Staphylococcus aureus and Clinical Characteristics of Different Sites of Infection.

Purpose: Since community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized, the molecular epidemiology of CA-MRSA in China has been diverse. It is unclear whether different sites of CA-MRSA infection differ in antimicrobial resistance and clinical characteristics. The purpose of this study was to identify the molecular types, virulence factors and antimicrobial resistance of CA-MRSA strains and to analyze the clinical characteristics of different sites of CA-MRSA infection. Methods: 26 CA-MRSA strains were screened from Beijing Chao-Yang Hospital from 2014 to 2022. SCCmec type, MLST type, spa type, Panton-Valentine leukocidin (PVL), hemolysin α (Hla), phenolic soluble regulatory protein α (PSMα), toxic shock syndrome toxin-1 (TSST-1), and enterotoxin (SE) A to E were detected by PCR and gene sequencing. Antimicrobial susceptibility tests and the clinical features of CA-MRSA infection cases were collected for statistical analysis. Results: The predominant type of CA-MRSA was ST59-t437-IV. New non-epidemic types, SCCmec VII, were also found. PVL was seen in 65.4% of CA-MRSA strains and TSST-1 was only be detected in 3.8% of CA-MRSA strain which caused poor prognosis. There were three types of infections: pneumonia (61.5%), infective endocarditis (7.7%), and skin and soft tissue infections (SSTIs) (30.8%). CA-MRSA pneumonia cases were secondary to influenza infection (37.5%). Patients with CA-MRSA-associated infective endocarditis were more likely to have underlying cardiac diseases. Patients with CA-MRSA-associated SSTIs were more likely to have a history of diabetes mellitus, and strains in this group were more susceptible to erythromycin and clindamycin. Conclusion: ST59-t437-IV was the primary CA-MRSA type in our research and in China. We proposed that TSST-1 might be one of the indicators to predict the severity and prognosis of CA-MRSA infection. Different sites of CA-MRSA infection had difference in antibiotics susceptibility testing and underlying diseases of patients. It could provide a new perspective on treating different types of CA-MRSA infection.

Physiological and biochemical changes during fruit maturation and ripening in highbush blueberry (Vaccinium corymbosum L.).

The sweetness of blueberry fruit increases over time, as acids are converted to sugars, and full flavor development is formed by harvest. We comprehensively analyzed the changes and correlation in physiological and biochemical characteristics of blueberries at different maturity stages, including texture, quality, taste and energy change. Our analysis revealed that total anthocyanin content increased and firmness decreased as fruit ripened. Percent moisture, titratable acid (TA), chlorophyll and carotenoid content also decreased, while total soluble solids (TSS), pH, TSS/TA ratio, vitamin C, soluble proteins, and ethylene production all increased. Antioxidant enzyme activity gradually increased during ripening but energy-related metabolites decreased. The flavor attributes of sweetness, bitterness, and sourness were readily perceived using an electronic tongue and a total of 76 volatile compounds were detected by GC-MS. In summary, the maturation of blueberries was correlated with increases of anthocyanins, nutrients, antioxidant activity, taste and aroma, but negatively correlated with energy metabolism.

Pyrazolone derivatives as potent and selective small-molecule SIRT5 inhibitors.

Sirtiun 5 (SIRT5) is a NAD+-dependent protein lysine deacylase. It is emerging as a promising target for the development of drugs to treat cancer and metabolism-related diseases. In this study, we screened 5000 compounds and identified a hit compound 14 bearing a pyrazolone functional group as a novel SIRT5-selective inhibitor. Structure-based optimization of 14 resulted in compound 47 with an IC50 value of 0.21 ± 0.02 µM and a 100-fold improved potency. Compound 47 showed substantial selectivity for SIRT5 over SIRT1-3 and SIRT6. Biochemical studies suggest that 47 does not occupy the NAD + -binding pocket and acts as a substrate-competitive inhibitor. The identified potent and selective SIRT5 inhibitors allow further studies as research tools and therapeutic agents.

(4-Picolylamino)-17ß-Estradiol derivative and analogues induce apoptosis with death receptor trail R2/DR5 in MCF-7.

In order to discover more effective and less toxic drugs in the field of anti-tumor, the backbone structure of 17ß-estradiol was modified, and 11 target compounds were synthesized. Compounds 5 and 10, which exhibited better anti-tumor activity and higher selectivity (more than 10-fold), were chosen for further biological investigation. Flow cytometry results indicated that 5 and 10 could arrest MCF-7 cells in the G2 phase and induce apoptosis. Immunohistochemical analysis revealed that 5 and 10 could bind to the estradiol receptor alpha in MCF-7 cells. Western blotting and real-time PCR assays were performed to detect the effects of compounds on apoptosis-related targets at the protein and gene levels. These results showed that both 5 and 10 could dosed-dependently increase the expression of Apaf-1, Bax, caspase-3,8,9 and reduce the expression levels of the anti-apoptotic factors Bcl-2 and Bcl-xL. Besides, the Human apoptosis array assay demonstrated the expression level of death receptor Trail R2/DR5 was upregulated obviously while the expression of TNF R1, IAPs and Hsp27/60/70 were downregulated. On the whole, 5 induced MCF-7 cell death through the endogenous pathway in mitochondria and the exogenous pathway with death receptor Trail R2/DR5.

Machine Learning Computing Migration and Management Based on Edge Computing of Multiple Data Sources in the Internet of Things.

With the implementation of the concepts of smart city and smart home, the number of user-intelligent terminal devices is increasing. The traditional computing framework cannot meet the increasing data volume and computing needs. Edge computing based on multiple data sources of the Internet of things can not only meet the computing needs of users' intelligent devices but also reduce energy consumption and user computing waiting time. Therefore, this article puts forward the research on the migration and management of deep reinforcement learning computing based on the edge computing of Internet of things multiple data sources, integrates the deep reinforcement computing technology in the edge computing of Internet of things multiple data sources, and optimizes the edge computing migration scheme and resource allocation management. The test results show that deep reinforcement learning can effectively control the cost of computing migration and enable it to complete computing tasks efficiently while maintaining stable operation. Compared with the traditional enhanced algorithm and the minimum migration scheme, the management model can complete the computing migration task with less energy consumption and shorter average computing waiting time.

Synthesis and in vitro/in vivo anticancer evaluation of pentacyclic triterpenoid derivatives linked with l-phenylalanine or l-proline.

Extensive research effort has been put in pentacyclic triterpenoids due to their numerous biological activities. However, their poor water solubility and low oral bioavailability limit their antitumor effects in vivo. To address these issues, 37 triterpenoid acid derivatives linked to l-phenylalanine or l-proline were designed and synthesized in this study. Structure-activity relationship (SAR) studies found two promising glycyrrhetinic acid (GA) derivatives 11 and 16. Compound 11 was obtained by C3-OH esterification and C30-COOH modification with l-phenylalanine while 16 was obtained by attaching C3-OH with l-phenylalanine. Compounds 11 and 16 exhibit up to 48- and 120-fold improvement respectively compared with the IC50 values of naturally occurring GA in the cellular assay. Fluorescence microscope and flow cytometric analysis suggested that both compounds 11 and 16 increased the content of ROS and Ca2+ in cancer cells, decreased mitochondrial membrane potential (JC-1), and activated the regulator caspase-3/8/9 to trigger cell apoptosis. RNA-seq analysis and western blot analysis indicated that compounds 11 and 16 may promote apoptosis by upregulating the functions of pro-apoptotic factors while inhibiting the proteasome activity.

MERS, SARS and other coronaviruses as causes of pneumonia.

Human coronaviruses (HCoVs) have been considered to be relatively harmless respiratory pathogens in the past. However, after the outbreak of the severe acute respiratory syndrome (SARS) and emergence of the Middle East respiratory syndrome (MERS), HCoVs have received worldwide attention as important pathogens in respiratory tract infection. This review focuses on the epidemiology, pathogenesis and clinical characteristics among SARS-coronaviruses (CoV), MERS-CoV and other HCoV infections.

Macrolide-resistant Mycoplasma pneumoniae prevalence and clinical aspects in adult patients with community-acquired pneumonia in China: a prospective multicenter surveillance study.

BACKGROUND: Drug resistant Mycoplasma pneumoniae (MP) is a rising issue in the management of community-acquired pneumonia (CAP). Epidemiological monitoring is essential for identifying resistant patterns of MP isolates against various antibiotics in adult CAP patients. METHODS: This is a prospectively designed multicenter study conducted on adult patients with CAP visiting six teaching hospitals in the cities of Beijing, Shanghai and Guangzhou between September 2010 and June 2012. RESULTS: A total of 520 adult patients (mean age: 45.7±26.2 years) with CAP visiting teaching hospitals in the cities of Beijing, Shanghai and Guangzhou were included. Of the 520 patients, only 75 (14.42%) were confirmed MP positive by means of culture and real-time PCR methods. Quinolones were the most common initially prescribed antimicrobial, followed by ß-lactams and ß-lactams plus quinolones. Macrolide resistance was as high as 80% and 72% against erythromycin (ERY) and azithromycin (AZM) respectively, which were associated with the A2063G transition mutation in domain V of the 23S ribosomal RNA (rRNA) gene. Six strains with mild to moderate ERY-resistant level were still susceptible to AZM. Tetracycline (TET), minocycline (MIN) and quinolones [moxifloxacin (MOX) and fluoroquinolones] had no signs of resistance. CONCLUSIONS: High resistance was observed with macrolides, whereas, none of the MP strains were resistant to fluoroquinolones and TET. Hence, macrolide resistant MP (MRMP)_infections could be well treated with fluoroquinolones. However, few isolated strains had minimal inhibitory concentration (MIC) values on the edge of resistance to quinolones, alarming a quinolone-resistant MP in the near future.

The microbiome in mechanically ventilated patients.

PURPOSE OF REVIEW: Discovery of a normal lung microbiome requires reassessment of our concepts of HAP/VAP pathogenesis and has important implications for clinical diagnosis and management. RECENT FINDINGS: Changes in the microbiome of dental plaque are associated with increased risk of HAP/VAP. A transition to a lung microbiome enriched with gut flora is found in ARDS with an increased inflammatory response in patients with this change in microbial flora. A characteristic microbiome pattern of higher amounts of bacterial DNA, lower community diversity, and greater relative abundance of a single species characterize pneumonia and occasionally identify bacteria not found in culture. The influence of the microbiome makes probiotics a logical strategy to prevent or ameliorate HAP/VAP but so far clinical support is unclear. SUMMARY: The presence of a normal lung microbiome and the interaction of that microbiome with other microbiota have an important but previously overlooked impact on the pathogenesis of HAP/VAP. Deep sequencing suggests that the repertoire of microorganisms and the pattern of bacterial communities associated with HAP/VAP remains incompletely understood but recent studies are adding greater clarity.

Overview of antimicrobial options for Mycoplasma pneumoniae pneumonia: focus on macrolide resistance.

BACKGROUND AND AIMS: Community-acquired pneumonia (CAP) is a common infectious disease affecting children and adults of any age. Mycoplasma pneumoniae has emerged as leading causative agent of CAP in some region, and the abrupt increasing resistance to macrolide that widely used for management of M. pneumoniae has reached to the level that it often leads to treatment failures. OBJECTIVE: We aim to discuss the drivers for development of macrolide-resistant M. pneumoniae, antimicrobial stewardship and also the potential treatment options for patients infected with macrolide-resistant M. pneumonia. METHODS: The articles in English and Chinese published in Pubmed and in Asian medical journals were selected for the review. RESULTS: M. pneumoniae can develop macrolide resistance by point mutations in the 23S rRNA gene. Inappropriate and overuse of macrolides for respiratory tract infections may induce the resistance rapidly. A number of countries have introduced the stewardship program for restricting the use of macrolide. Tetracyclines and fluoroquinolones are highly effective for macrolide-resistant strains, which may be the substitute in the region of high prevalence of macrolide-resistant M. pneumoniae. CONCLUSION: The problem of macrolide resistant M. pneumonia is emerging. Antibiotic stewardship is needed to inhibit the inappropriate use of macrolide and new antibiotics with a more acceptable safety profile for all ages need to be explored.

Antibiotic Resistance in Community-Acquired Pneumonia Pathogens.

The overwhelming majority of cases of community-acquired pneumonia (CAP) can be treated with the standard antibiotic regimens of a macrolide and cephalosporin or a fluoroquinolone. Despite high rates, current levels of ß-lactam resistance generally do not result in treatment failure for patients with CAP when appropriate agents and doses are used. Following the introduction of the pneumococcal conjugate vaccines, the incidence of invasive pneumococcal disease declined drastically, coinciding with a decrease in penicillin resistance. Risk factors for methicillin-resistant S. aureus follow two patterns: (1) healthcare-associated risk factors and (2) pneumonia from exotoxin-producing community-acquired strains. The latter is associated with need for antibiotics which inhibit protein synthesis for optimal management. Since 2000, macrolide-resistance in M. pneumoniae has rapidly emerged worldwide, especially in Asian countries. The inability to routinely culture H. influenzae suggests that macrolide and ß-lactam resistance, while present, is not a big issue. Unless risk factors for a hospital-associated strain are present, the most common Enterobacteriaceae to cause CAP, including Escherichia coli and Klebsiella, are generally susceptible to usual CAP antibiotics. Given the limited role of antibiotic resistance in CAP, a strong rationale is needed for use of antibiotics other than the standard ß-lactam/macrolide or fluoroquinolone regimens.

Specific multilocus variable-number tandem-repeat analysis genotypes of Mycoplasma pneumoniae are associated with diseases severity and macrolide susceptibility.

Clinical relevance of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) in patients with community-acquired pneumonia (CAP) by Mycoplasma pneumoniae (M. pneumoniae) is unknown. A multi-center, prospective study was conducted from November 2010 to April 2012. Nine hundred and fifty-four CAP patients were consecutively enrolled. M. pneumoniae clinical isolates were obtained from throat swabs. MLVA typing was applied to all isolates. Comparison of pneumonia severity index (PSI) and clinical features among patients infected with different MLVA types of M. pneumoniae were conducted. One hundred and thirty-six patients were positive with M. pneumoniae culture. The clinical isolates were clustered into 18 MLVA types. One hundred and fourteen (88.3%) isolates were resistant to macrolide, covering major MLVA types. The macrolide non-resistant rate of M. pneumoniae isolates with Mpn13-14-15-16 profile of 3-5-6-2 was significantly higher than that of other types (p ≤ 0.001). Patients infected with types U (5-4-5-7-2) and J (3-4-5-7-2) had significantly higher PSI scores (p<0.001) and longer total duration of cough (p = 0.011). Therefore it seems that there is a correlation between certain MLVA types and clinical severity of disease and the presence of macrolide resistance.

Multiple-locus variable-number tandem-repeat analysis of 201 Mycoplasma pneumoniae isolates from Beijing, China, from 2008 to 2011.

A total of 201 Mycoplasma pneumoniae clinical isolates from Beijing, China, isolated from 2008 to 2011, were clustered into 16 multiple-locus variable-number tandem-repeat analysis (MLVA) types, of which 6 new MLVA types have never been reported previously. Type 1 isolates based on p1 gene genotyping were mainly MLVA types E, J, P, U, and X. There was no correlation between macrolide-resistant Mycoplasma pneumoniae and their MLVA type.

Surveillance of macrolide-resistant Mycoplasma pneumoniae in Beijing, China, from 2008 to 2012.

Macrolide resistance rates of Mycoplasma pneumoniae in the Beijing population were as high as 68.9%, 90.0%, 98.4%, 95.4%, and 97.0% in the years 2008 to 2012, respectively. Common macrolide-resistant mobile genetic elements were not detected with any isolate. These macrolide-resistant isolates came from multiple clones rather than the same clone. No massive aggregation of a particular clone was found in a specific period.

[Survey of macrolide resistance in Mycoplasma pneumoniae in adult patients with community-acquired pneumonia in Beijing, China].

OBJECTIVE: To explore the tendency of macrolide resistance in Mycoplasma pneumoniae infection in community-acquired pneumonia (CAP) patients in Beijing. METHODS: Adult CAP patients of ≥ 18 yrs were enrolled in 3 medical centers in Beijing , China. Throat swab samples were taken from all the patients to perform the culture of M. pneumoniae . All the isolated M. pneumoniae strains were subjected to susceptibility evaluation for 6 agents, including macrolides such as erythromycin and azithromycin. In strains showing macrolide resistance, the 23S rRNA gene was analyzed. RESULTS: A total 53 strains of M. pneumoniae were isolated from 321 enrolled patients. Thirty-eight of the isolated strains (71.7%) were resistant to erythromycin and 32 of them (60.4%) were resistant to azithromycin. Six strains with moderate or low level of erythromycin-resistance were still susceptible to azithromycin. No fluoroquinolone-resistant or tetracycline-resistant strains were observed in our study. Point transition of A2063G in the 23S ribosomal RNA gene was the main reason for the high prevalence of macrolide resistance. CONCLUSIONS: The prevalence of macrolide resistance in M. pneumoniae is very high in adult CAP patients in Beijing. Studies are needed to clarify the clinical meaning of prevalence of macrolide-resistant M. pneumoniae in adults CAP patients.

Evaluation of the Japanese Respiratory Society guidelines for the identification of Mycoplasma pneumoniae pneumonia.

BACKGROUND AND OBJECTIVE: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Mycoplasma pneumoniae is one of the major causative pathogens of CAP. Early diagnosis of M. pneumoniae pneumonia is crucial for initiating appropriate antibiotic therapy. The aim of this study was to determine whether the Japanese Respiratory Society (JRS) guidelines on CAP are effective for diagnosing M. pneumoniae pneumonia. METHODS: Between August 2008 and July 2009, adult outpatients with CAP were consecutively enrolled. The aetiology of CAP was determined by culture and real-time polymerase chain reaction (PCR) methods to detect M. pneumoniae, urine antigen tests to detect Streptococcus pneumoniae and Legionella pneumoniae, blood and sputum culture for bacteria and real-time PCR for eight common respiratory viruses. The predictive value of the JRS guidelines for differentiating M. pneumoniae pneumonia from typical bacterial and viral pneumonias was determined. RESULTS: Data from 215 adult CAP outpatients was analyzed. An aetiological diagnosis was made for 105 patients (48.8%), including 62 patients with M. pneumoniae pneumonia, 17 patients with typical bacterial pneumonia and 23 patients with viral pneumonia. According to the JRS criteria for differential diagnosis of atypical pneumonia, 55 of 62 patients were correctly diagnosed with M. pneumoniae pneumonia (sensitivity 88.7%), and 31 of 40 patients with bacterial and viral pneumonia were correctly excluded (specificity 77.5%). CONCLUSIONS: The JRS guidelines on CAP provide a useful tool for the identification of M. pneumoniae pneumonia cases and differentiating these from cases of typical bacterial or viral pneumonia.

Sequence analysis of the p1 adhesin gene of Mycoplasma pneumoniae in clinical isolates collected in Beijing in 2008 to 2009.

The p1 genes of 60 Mycoplasma pneumoniae clinical isolates were sequenced and compared to previously reported p1 gene sequences. An AGT trinucleotide variable-number tandem repeat was identified that ranged in copy number from 5 to 14 among the isolates. In addition, a novel p1 gene variant named 2c was identified in 6 of the isolates.

Clinical features of pneumonia caused by 2009 influenza A(H1N1) virus in Beijing, China.

BACKGROUND: Data on symptoms and radiographic changes in patients with pandemic 2009 influenza A(H1N1) (A[H1N1]) pneumonia during convalescence have not been reported. METHODS: During October 26, 2009, and January 23, 2010, adult patients with pneumonia with laboratory-confirmed or clinically suspected A(H1N1) infections were observed for clinical characteristics, high-resolution chest CT scan, and lung function test changes during acute and 3-month convalescent phases. RESULTS: Of the 65 case subjects, the median age was 41 (interquartile range [IQR], 28-57) years, 60.0% were men, and 55.4% had at least one underlying medical condition. Sixty-two patients started oseltamivir therapy within a median of 5 (IQR, 4-6) days from the onset of illness, and 31 received IV corticosteroids. ARDS developed in 33 patients, and 24 were treated initially with noninvasive positive pressure ventilation (NPPV). In this group, NPPV was successful in 13 patients (54.2%). Nine patients died at a median of 16 (IQR, 10-24) days after onset of illness. Multivariate Cox regression identified two independent risk factors for death: progressive dyspnea after resolution of fever (relative risk, 5.852; 95% CI, 1.395-24.541; P = .016) and a higher APACHE (Acute Physiology and Chronic Health Evaluation) II score on presentation (relative risk for each point, 1.312; 95% CI, 1.140-1.511; P < .001). At 3-month follow-up of survivors with A(H1N1), ground-glass opacities were still present, although diminished, in 85.7%, and diffusing capacity for carbon monoxide was mildly reduced in 61.5%. CONCLUSIONS: Ground-glass opacities and decreased diffusing capacity were the main abnormalities observed at 3-month follow-up of survivors of A(H1N1).

High prevalence of macrolide resistance in Mycoplasma pneumoniae isolates from adult and adolescent patients with respiratory tract infection in China.

The resistance rate of 67 Mycoplasma pneumoniae isolates from 356 ambulatory adult patients with respiratory tract infection was 69% (46 of 67). All 46 macrolide-resistant strains harbored point mutations in the 23S ribosomal RNA gene. Patients infected with macrolide-resistant M. pneumoniae required significantly longer durations of antibiotic therapy and had longer time to resolution of fever.