[A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies]

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

A cellular mechanism underlying the restoration of thermo/photoperiod-sensitive genic male sterility

During anther development, the transformation of the microspore into mature pollen occurs under the protection of first the tetrad wall and later the pollen wall. Mutations in genes involved in this wall transition often lead to microspore rupture and male sterility; some such mutants, such as the reversible male sterile (rvms) mutant, are thermo/photoperiod-sensitive genic male sterile (P/TGMS) lines. Previous studies have shown that slow development is a general mechanism of P/TGMS fertility restoration. In this study, we identified restorer of rvms-2 (res2), which is an allele of QUARTET 3 (QRT3) encoding a polygalacturonase that shows delayed degradation of the tetrad pectin wall. We found that MS188, a tapetum-specific transcription factor essential for pollen wall formation, can activate QRT3 expression for pectin wall degradation, indicating a non-cell-autonomous pathway involved in the regulation of the cell wall transition. Further assays showed that a delay in degradation of the tetrad pectin wall is responsible for the fertility restoration of rvms and other P/TGMS lines, whereas early expression of QRT3 eliminates low temperature restoration of rvms-2 fertility. Taken together, these results suggest a likely cellular mechanism of fertility restoration in P/TGMS lines, that is, slow development during the cell wall transition of P/TGMS microspores may reduce the requirement for their wall protection and thus support their development into functional pollens, leading to restored fertility.

The Identification and Genetic Characterization of Parechovirus Infection Among Pediatric Patients With Wide Clinical Spectrum in Chongqing, China

Human parechoviruses (HPeVs) are important causes of infection in children. However, without a comprehensive and persistent surveillance, the epidemiology and clinical features of HPeV infection remain ambiguous. We performed a hospital-based surveillance study among three groups of pediatric patients with acute respiratory infection (Group 1), acute diarrhea (Group 2), and hand, foot and mouth disease (Group 3) in Chongqing, China, from 2009 to 2015. Among 10,212 tested patients, 707 (6.92%) were positive for HPeV, with the positive rates differing significantly among three groups (Group 1, 3.43%; Group 2, 14.94%; Group 3, 3.55%; P < 0.001). The co-infection with other pathogens was detected in 75.2% (531/707) of HPeV-positive patients. Significant negative interaction between HPeV and Parainfluenza virus (PIV) (P = 0.046, OR = 0.59, 95% CI = 0.34–0.98) and positive interactions between HPeV and Enterovirus (EV) (P = 0.015, OR = 2.28, 95% CI = 1.23–4.73) were identified. Among 707 HPeV-positive patients, 592 (83.73%) were successfully sequenced, and 10 genotypes were identified, with HPeV1 (n = 396), HPeV4 (n = 86), and HPeV3 (n = 46) as the most frequently seen. The proportion of genotypes differed among three groups (P < 0.001), with HPeV1 and HPeV4 overrepresented in Group 2 and HPeV6 overrepresented in Group 3. The spatial patterns of HPeV genotypes disclosed more close clustering of the currently sequenced strains than those from other countries/regions, although they were indeed mixed. Three main genotypes (HPeV1, HPeV3, and HPeV4) had shown distinct seasonal peaks, highlighting a bi-annual cycle of all HpeV and two genotypes (HPeV 1 and HPeV 4) with peaks in odd-numbered years and with peaks in even-numbered years HPeV3. Significantly higher HPeV1 viral loads were associated with severe diarrhea in Group 2 (P = 0.044), while associated with HPeV single infection than HPeV-EV coinfection among HFMD patients (P = 0.001). It’s concluded that HPeV infection was correlated with wide clinical spectrum in pediatric patients with a high variety of genotypes determined. Still no clinical significance can be confirmed, which warranted more molecular surveillance in the future.

[Diagnosis of adult Philadelphia chromosome-like acute lymphoblastic leukemia by fluorescence in situ hybridization]

目的

建立应用荧光原位杂交技术（FISH）筛查成人Ph样急性淋巴细胞白血病（ALL）的体系。

方法

根据Ph样ALL的遗传学特征，设计了针对ABL1、ABL2、JAK2、EPOR、CRLF2、CSF1R、PDGFRB、P2RY8等基因断裂重排的FISH探针；对BCR-ABL1、ETV6-RUNX1、MLL基因断裂重排和E2A断裂重排均阴性的B-ALL，采用FISH进行Ph样ALL筛查，并结合流式免疫表型、靶向二代测序突变检测和RNA测序进行Ph样ALL诊断分析。

结果

2016年1月至2019年4月，南方医院血液科收治189例成人B-ALL，经FISH和（或）PCR检测，BCR-ABL1、ETV6-RUNX1、MLL断裂重排或E2A断裂重排阳性者共83例；其余106例患者接受Ph样ALL FISH探针筛查，其中，12例（11.3％）检出典型的Ph样ALL特异基因断裂重排，2例检出基因缺失。经RNA测序进一步验证，FISH检测Ph样ALL基因断裂重排结果灵敏度为71.4％，特异度为95.8％。综合免疫表型、靶向二代测序突变检测和RNA测序，共诊断融合基因阳性Ph样ALL 14例（13.2％）。

结论

FISH技术检测Ph样ALL具有较高的特异性，结合免疫表型和测序技术可完善诊断体系。

[The effect of booster dose vaccination 21- to 32-years after primary vaccination with hepatitis B vaccine in the population born from 1986 to 1996 in Zhengding County of Hebei Province]

Objective: Aanalysis the effect of booster one dose of hepatitis B vaccine after 21-32 years of primary immunization in Zhengding Country of Hebei Province. Methods: A total of 322 participants who were born between 1986 and 1996, received a full course of primary vaccination with plasma-derived hepatitis B vaccine (HepB), had no experience with booster vaccination, were HBsAg, anti-HBcnegative, had anti-HBs<10 mIU/ml, completed the booster and had laboratory results were enrolled between August 2017 to February 2018. A simple random method was uesd to randomly assigned 322 subjects to two groups, receiving a booster dose of HepB derived from either Saccharomyces cerevisiae ［HepB (SC), (151 cases)］ or Chinese hamster ovary-derived HepB ［HepB (CHO), (171 cases)］, the dose was 20 μg. Blood samples were collected 30 days after boosting and quantitatively tested for the geometric mean concentration (GMC) of anti-HBs to assess immunological effect. The related influencing factors of GMC and seroconversion rates of anti-HBs were analyzed by multiple linear regression and multivariate logistic regression models. Results: The 266 subjects (82.61%) had anti-HBs≥ 10 mIU/ml, and GMC was (131.63±12.94) mIU/ml.The seroconversion rates of anti-HBs in the anti-HBs<2.5 mIU/ml group and 2.5-10 mIU/ml group were 74.54% (161 cases) and 99.06% (105 cases), respectively (P<0.001).The seroconversion rates of anti-HBs after one dose of HepB (CHO) was higher than that of one dose of HepB (SC), the seroconversion rates were 87.13% (149 cases) and 77.48% (117 cases), respectively (P=0.023). Participants boostered with HepB (CHO) was the factor influencing the effect of strengthening immunization compared with boostered with HepB (SC), and OR (95%CI) was 1.91 (1.02-3.56) (P=0.042).Compared with anti-HBs<2.5 mIU/ml, prebooster anti-HBs was between 2.5 mIU/ml and 10 mIU/ml was the related factor of seroconversion rates of anti-HBs after booster immunization, and OR (95%CI) was 36.15 (4.91-266.02) (P<0.001). Conclusion: Participants boostered withone dose of HepB had a good immune response. Pre-booster anti-HBs concentration and a variety of vaccine were related factors of immune response.

[Involvement of Src kinase in the down-regulation of ultra-rapid delayed rectifier K(+)current induced by tumor necrosis factor-α in cardiomyocytes]

Objective: To investigate whether inflammatory factor tumor necrosis factor-α (TNF-α) is involved in the electrical remodeling of cardiomyocytes by regulating ultra-rapid delayed rectifier K(+) current (I(kur)) and the role of Src kinase. Methods: H9c2 cells, embryonic cardiomyocytes of rat, were cultured in Dulbecco's modified Eagle's medium (DMEM) and atrium-derived HL-1 cells were cultured in Claycomb medium. Both H9c2 and HL-1 cells were cultured at 37 ℃ with 5% CO(2). Cells cultured in normal conditions without additional treatment served as control group. Experimental groups were treated with different concentration of TNF-α (25 or 50 or 100 ng/ml) for 24 hours. To study whether Src specific inhibitor PP1 could abrogate the effect of TNF-α, cells were pre-treated with 10 μmol/L PP1 for 1 hour, followed by TNF-α (100 ng/ml) for 24 hours. Western blot and the whole cell patch clamp technique were used to detect the protein expression of Kv1.5 and Src and I(kur) in each group. Results: (1) In H9c2 cells, high concentration of TNF-α treatment (100 ng/ml) significantly reduced the Kv1.5 protein expression compared with control group and TNF-α 25 ng/ml group (both P<0.05). Compared with control group, the expression of p-Src protein was higher in 25 ng/ml, 50 ng/ml, 100 ng/ml TNF-α group (all P<0.05), but there was no statistical difference in the expression of Src protein among groups (P>0.05). In addition, the current density of I(kur) was decreased in 50 ng/ml, 100 ng/ml TNF-α group (both P<0.05). Furthermore, the expression of Kv1.5 protein and the current density of I(kur) were increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (both P<0.05). There was no statistical difference in the expression of Kv1.5 protein and the current density of I(kur) between the control group and PP1+TNF-α group (both P>0.05). (2) In atrium-derived HL-1 cells, the expression of Kv1.5 protein was reduced in 100 ng/ml TNF-α group compared with control group and TNF-α 25 ng/ml group (both P<0.01). In addition, the expression of p-Src protein was increased in TNF-α 100 ng/ml group compared with control group (P<0.05), but there was no statistical difference in the protein expression of Src among groups (P>0.05). The expression of Kv1.5 protein was increased in PP1+TNF-α group compared with TNF-α 100 ng/ml group (P<0.05). Conclusion: TNF-α is involved in the pathogenesis of atrial fibrillation, probably via decreasing I(kur) current density in atrium-derived myocytes through the activation of Src kinase.

Positive regulation of AMS by TDF1 and the formation of a TDF1-AMS complex are required for anther development in Arabidopsis thaliana

Tapetum development and pollen production are regulated by a complex transcriptional network that consists of a group of tapetum-specific Arabidopsis transcription factors (TFs). Among these TFs, DEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION 1 (TDF1) encodes an R2R3 MYB factor, and ABORTED MICROSPORE (AMS) encodes a basic helix-loop-helix (bHLH) factor. However, knowledge regarding the regulatory role of TDF1 in anther development remains limited. Here, we discovered that TDF1 directly regulates AMS via an AACCT cis-element. We found the precocious AMS transcript and absence of AMS protein in ams^-/- gpTDF1:AMS-FLAG lines, suggesting the timing of the TDF1-regulated AMS expression is a prerequisite for AMS functioning. We found that TDF1 interacts with AMS. Additionally, the TDF1-AMS complex additively promotes the expression of AMS-regulated genes, suggesting that TDF1 and AMS regulate the downstream genes through a feed-forward loop. EPXB5, encoding a beta-expansin family protein, is another direct target of TDF1, and it is highly expressed in the tapetum and pollen grains. The TDF1-AMS complex acts in concert to activate EXPB5 expression through a feed-forward loop. The identification of the regulatory pathway between TDF1 and AMS provides an interlocked feed-forward loop circuit that precisely regulates the transcriptional cascades that support anther development.

[Clinical analysis of adult Philadelphia chromosome-positive acute lymphoblastic leukemia with p16 gene deletion]

目的

探讨p16基因缺失在成人Ph染色体阳性急性淋巴细胞白血病（Ph⁺ ALL）中的临床意义。

方法

回顾性分析80例Ph⁺ALL伴p16基因缺失患者的临床特征、免疫表型、细胞遗传学、分子生物学改变及其预后。

结果

31.3% Ph⁺ALL患者合并p16基因缺失；p16基因缺失组与非缺失组相比，初诊时高白细胞计数（WBC≥30×10⁹/L）更常见，高表达CD20，更易出现附加染色体异常，其中以累及7、8、19号染色体以及der（22）较为常见；两组诱导缓解率比较差异无统计学意义（P=0.033），p16基因缺失组患者治疗3个疗程后获BCR-ABL融合基因主要分子学反应（MMR）率和完全分子学反应（CMR）率均明显低于非缺失组（P值分别为0.034和0.036），且复发率明显高于非缺失组（P=0.033）；p16基因缺失组使用伊马替尼联合化疗者和使用达沙替尼联合化疗者的MMR、CMR率及复发率差异均无统计学意义（P值均>0.05）；p16基因缺失组患者3年总体生存（OS）率及无病生存（DFS）率分别为37.1%和12.4%，显著低于非缺失组的54.1%和45.9%（P值分别为0.037和0.026）；25例p16基因缺失患者中14例行异基因造血干细胞移植（allo-HSCT），其中位OS时间为21个月，明显长于非移植组患者的12个月（P=0.030）。

结论

成人Ph⁺ALL伴p16基因缺失患者预后相对较差，二代酪氨酸激酶抑制剂不能明显改善其疗效，但allo-HSCT能够改善部分患者的生存，明确p16基因缺失状态对于评估预后和指导临床治疗有重要意义。

Detection and study of plasma D-dimer change in patients with acute exacerbation of chronic obstructive pulmonary disease

The purpose of this study was to observe the change in plasma D-dimer of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The patients were divided into three groups, i.e., AECOPD group, stable COPD group (COPD kept stable after treatment) and a healthy control group. The content of plasma fibrinogen (FIB) and D-dimer of all research subjects was detected and the difference between groups was analyzed. Moreover, pulmonary functions of patients in the AECOPD group and the stable COPD group, including forced expiratory volume in 1 second (FEV1%) and forced vital capacity rate of 1 second (FEV1/FVC), and blood gas (oxygen partial pressure (PO₂) and partial pressure of carbon dioxide (PaCO₂), were detected; and the differences between the two groups and the possible correlation were analyzed. Compared to the COPD stable group and the control group, the AECOPD group had a statistically significant higher content of plasma FIB and D-dimer (p less than 0.05); the content of plasma FIB and D-dimer of the COPD stable group was much higher than that of the healthy control group, but the difference had no statistical significance (p > 0.05); the content of D-dimer of AECOPD patients was in a negative correlation with FEV1 and PO₂ (p smaller than 0.05) and in a positive correlation with PCO₂ (p smaller than 0.05). It can be concluded that D-dimer is correlated to the severity of AECOPD; hence, it can be used as an evaluation index for the severity of AECOPD.

Overexpression of HSP27 in cultured human aortic smooth muscular cells reduces apoptosis induced by low-frequency and low-energy ultrasound by inhibition of an intrinsic pathway

We investigated in vitro the effect of low-frequency and low-energy ultrasound (LFLEU) on apoptosis of an overexpressed HSP27 human aortic smooth muscle cell (HASMC) line. A frequency of 42.6 kHz was used in all experiments. HASMC were exposed to ultrasound and cell viability was evaluated by MTT reduction. Overexpressed HSP27-HASMC was constructed on a pcDNA3.1 vector. Apoptosis was determined 24 h after treatment by flow cytometry; gene display was evaluated with Affimax chips, and HSP27 mRNA and protein expression levels were measured by RT-PCR and Western blotting. The apoptosis rate (at 30 s) was significantly lower in HASMC transfected with HSP27 (7.14 ± 1.73%), compared with cells transfected with a mock plasmid (17.31 ± 2.72%) or a control group (14.23 ± 2.77%), indicating a protective function for apoptosis induced by LFLEU. Gene display analysis showed that caspase-9 expression in HSP27 cell lines was downregulated and caspase-3 upregulated. However, RT-PCR and Western blotting analysis indicated that both caspase-9 and caspase-3 were inhibited at both the mRNA and protein levels. We suggest that overexpressed HSP27 is capable of protecting the LFLEU from apoptosis and that the pathway for this protection is via downregulated caspase-9 and caspase-3 expression.

Association analyses identify six new psoriasis susceptibility loci in the Chinese population

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻⁸) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.

Selective replication of E1B55K-deleted adenoviruses depends on enhanced E1A expression in cancer cells

E1B55K-deleted dl1520 could selectively replicate in cancer cells and has been used in clinical trials as an antitumor agent. The mechanism of virus selective replication in cancer cells, including a possible role of p53, is unclear. Studies with established cancer cell lines have demonstrated that some cancer cells are resistant to dl1520 replication, regardless of the p53 status. Hep3B cells supported the E1b-deleted adenoviruses to replicate, whereas Saos2 cells were resistant to viral replication. We applied p53-null Hep3B and Saos2 cells as models to clarify the replication ability of E1B55K-deleted adenoviruses with different expression levels of E1a. We show that lower E1A expression in Saos2 may be the reason for the poor replication in some cancer cells due to the fact that E1a promoter was less activated in Saos2 than in Hep3B. We also demonstrate that the E1B55K protein can increase E1A expression in Saos2 cells for efficient virus replication. In addition, the upstream regions of the E1a promoter have transcriptional activity in Hep3B cells but not in Saos2 cells. The viral E1B55K protein may activate cancer cellular factor(s) that targets the upstream regions of the E1a gene to increase its expression. This is the first study demonstrating that E1B55K protein affects the E1A production levels that is related to cancer selective replication. Our studies have suggested that increase of E1A expression from E1b-deleted adenoviruses may enhance killing cancer cells that otherwise are resistant to viral replication.

Traumatic thrombophlebitis of the superficial dorsal vein of the penis: an occupational hazard

Several cases of thrombophlebitis of the superficial dorsal vein of the penis (TSDVP) have been reported in the literature. Etiologies may include any of the following: trauma associated with vigorous sexual intercourse; penile strangulation caused by a multitude of entities; penile injection; infection; neoplasm; or surgery. We report a rare case of traumatic TSDVP in a cab driver following repeated injury to the penis by a coin-filled pouch. We review the etiologies, mechanism, and treatment of traumatic TSDVP, and attempt to identify men who may be at similar occupational risk.

Probing the activation of the replicative origin of broad host-range plasmid R1162 with Tus, the E.coli anti-helicase protein

The E.coli Tus protein is an anti-helicase involved in the termination of chromosome replication. The binding site for this protein, ter, was cloned into derivatives of the broad host-range plasmid R1162. The ter site caused the orientation-specific termination of plasmid replication fork movement in cell extracts containing Tus. Plasmids were constructed so that two sites for initiation of R1162 replication flanked the iteron-containing domain of the origin. In these plasmids, the site next to the AT-rich region within the iteron-containing domain was more active. In addition, when ter was placed between the more active site and the iterons, initiation of replication from this site was specifically inhibited. The data support a model for entry of the essential, plasmid-encoded helicase at one side of the direct repeats, and for its movement primarily in one direction away from these repeats to activate the initiation sites for DNA replication.

Deletion of sites for initiation of DNA synthesis in the origin of broad host-range plasmid R1162

The origin of replication of the broad host-range plasmid R1162 contains two, oppositely facing initiation sites for DNA synthesis. Either of these sites can be deleted from an R1162 plasmid derivative. However, the resulting plasmids are unstable, maintained at a lower copy-number in the cell, and form dimers and other recombinants that are required for propagation of the plasmid. In vitro, a derivative lacking one initiation site is deficient in synthesis of the strand normally initiated from that site. The properties of the intact origin are restored if it contains two oppositely facing sites; one initiation site may substitute for the other, and each site need not be in its original orientation. Overall, the results suggest that synthesis of each strand of R1162 DNA is initiated at a single site, and that there is no efficient system for initiation of lagging strand synthesis during transit of the replication forks.