[Molecular characterization of Staphylococcus aureus ST6 and ST7 isolates from food-borne illness outbreaks]

Objective: To analyze the Staphylococcal enterotoxins, Staphylococcal enterotoxin genes, drug resistance and molecular typing of 41 Staphylococcus aureus isolates from 2 food-borne illness outbreaks on 21 August and 27 September 2020 in Guangzhou. Methods: A total of 41 Staphylococcus aureus isolates from 2 outbreaks were analyzed by multilocus sequence typing (MLST) and spa typing. The Staphylococcal enterotoxins typing and the Staphylococcal enterotoxin genes of the isolates were analyzed by ELISA and PCR, respectively. The antimicrobial susceptibility of the isolates was performed by disc diffusion. 21 Staphylococcus aureus isolates were characterized using whole genome sequencing (WGS). Based on the whole genome single nucleotide polymorphism (SNP), the phylogenetic tree was constructed by Snippy. Results: 41 Staphylococcus aureus isolates were divided into 2 types by MLST and spa typing: ST6-t701 and ST7-t091. 2 ST7-t091 isolates were identified as methicillin-resistant Staphylococcus aureus (MRSA). 25 ST7-t091 isolates and 14 ST6-t701 isolates were methicillin-sensitive Staphylococcus aureus (MSSA), and were resistant to 7 and 6 antibiotics, respectively. All isolates were positive for sea by PCR. WGS revealed all 21 isolates carried scn, sak, sea, hla, hld, hlgA, hlgB, hlgC, lukD virulence genes. The results showed the isolates contained an immune evasion cluster type D which located in bacteriophage ϕSa3. The SNP phylogenetic tree showed 2 MRSA ST7-t091 were constituted a separate clade from the 12 MSSA ST7-t091 isolates and 7 ST6-t701 isolates showed high similarity to each other. Conclusion: Base on the results of phylogenetic analysis, the 2 food-borne illness outbreaks occurred on 21 August and 27 September 2020 are caused by the combination of the MRSA ST7-t091 strain and the MSSA ST7-t091 strain, and the MSSA ST6-t701 strain, respectively. All isolates have high level of antibiotic resistance and carry high virulent genes.

Observation of High-Frequency Transverse Phonons in Metallic Glasses

Using inelastic neutron scattering and molecular dynamics simulations on a model Zr-Cu-Al metallic glass, we show that transverse phonons persist well into the high-frequency regime, and can be detected at large momentum transfer. Furthermore, the apparent peak width of the transverse phonons was found to follow the static structure factor. The one-to-one correspondence, which was demonstrated for both Zr-Cu-Al metallic glass and a three-dimensional Lennard-Jones model glass, suggests a universal correlation between the phonon dynamics and the underlying disordered structure. This remarkable correlation, not found for longitudinal phonons, underscores the key role that transverse phonons hold for understanding the structure-dynamics relationship in disordered materials.

[The impact of weight management and related diuretic medication intervention based on body weight changes on cardiac function and re-hospitalization rate in patients with chronic congestive heart failure]

Objective: To explore the impact of weight management and related medication intervention based on body weight changes on cardiac function among patients with chronic congestive heart failure (CHF). Methods: Using prospective, randomized, controlled study methods, consecutive CHF patients, who hospitalized in our department from June 2014 to June 2016 (n=350), were randomly divided into intervention group (n=175) and control group (n=175). Patients in the intervention group received weight management guidance and the post discharge diuretic drugs regimen was adjusted based on body weight changes. The control group received routine medical care post discharge. Left ventricular ejection fraction (LVEF), B type natriuretic peptide precursor (NT-proBNP), 6 minutes walk distance and NYHA classification at one day before discharge and after 6 months were compared between the two groups respectively. Results: Follow-up visit data were not available from 6 patients in the control and intervention group respectively. NYHA classification, LVEF, NT-proBNP and 6 minutes walk distance were similar between the two groups at one day before discharge (all P>0.05). After 6 months, the LVEF and 6 minutes walk distance were significantly higher while NT-proBNP level was significantly lower in the intervention group compared to the control group (all P<0.01). Meanwhile, the LVEF and 6 minutes walk distance were significantly increased, while NT-proBNP was significantly reduced at 6 months post discharge compared to one day before discharge in the intervention group (all P<0.01). The LVEF was also significantly improved (P=0.035), but the NT-proBNP and 6 minutes walk distance were similar (P were 0.328 and 0.807 respectively) at 6 months after discharge compared to one day before discharge in the control group. The NYHA classification was significantly lower in intervention group and in control group at 6 months after discharge compared to one day before discharge (Z=5.154, P<0.01 and Z=10.497, P<0.01), and the NYHA classification improved more in the intervention group than in control group at 6 months after discharge (Z=9.235, P<0.01). The re-hospitalization rate of CHF patients in intervention group was 11.83% (20/169), which was significantly lower than the control group (33.14% (56/169), χ(2)=21.99, P<0.01). At 6 months follow up, body weight remained unchanged in the intervention group, while body weight tended to be higher in the control group compared to one day before discharge. Conclusion: The weight management and diuretic drug regimen adjudgment intervention based on body weight changes can improve cardiac function and reduced re-hospitalization rate in CHF patients.

[Retrospective analysis of diagnosis and treatment of breast cancer in pregnancy]

Objective: To investigate the principles of diagnosis and treatment of breast cancer during pregnancy. Methods: Clinical data of patients with breast cancer during pregnancy admitted to Obstetrics and Gynecology Hospital of Fudan University between January 2012 to July 2017 were analyzed retrospectively. A total of 17 patients were diagnosed with breast cancer in pregnancy, the median age was 32 years (range from 25 to 45 years old), pathological staging revealed 2 patient with stage 0, 1 with stage Ⅱa, 7 with stage Ⅱb, 1 with stage Ⅲa, 2 with stage Ⅲc, 4 with stage Ⅳ. Results: Thirteen patients received surgical treatment in pregnancy, the gestational age at surgery was (27.7±4.6) weeks; 2 patients with ductal carcinoma in situ received mastectomy, 11 patients with breast cancer underwent modified radical mastectomy. In patients undergoing surgery during pregnancy, no prophylactic contractions were used in 4 patients who had been treated earlier, there were 2 patients with frequent contractions within 24 hours after operation in these patients. Follow-up 9 patients were given oral nifedipine to prevent contractions, no obvious contractions occurred after the operation. Seven patients received chemotherapy during pregnancy; the chemotherapy of 4 cases of triple negative breast cancer was weekly paclitaxel sequential epirubicin and cyclophosphamide, the chemotherapy of the other three patients was docetaxel sequential epirubicin and cyclophosphamide. Fifteen patients underwent cesarean section to terminate pregnancy, 2 patients underwent spontaneous labor. The gestational age of birth was (36.9 ±1.3) weeks. Less than 35 weeks of termination of pregnancy occurred in one patient, the fetus was delivered to the neonatal intensive care unit due to neonatal respiratory distress syndrome, and suffered from congenital dysaudia. The prognosis of the other 16 survived infants was good. The median follow-up time was 10 months (range from 4 to 27) months, in 13 patients of stage 0 to Ⅲc, one patient were diagnosed with bone metastasis at 12 months after surgery, the remaining 12 patients had no disease progression, the progression free survival rate was 12/13, the overall survival rate was 13/13. Among the 4 patients with stage Ⅳ, one died in 7 months after delivery, one had new liver metastasis in 8 months after delivery. The remaining 2 patients were in stable condition. Conclusions: Breast cancer in pregnancy can be treated effectively, multidisciplinary cooperation and detailed assessment of maternal-fetal risks and benefits are necessary. Chemotherapy during pregnancy is safe for maternal-fetal, but it needed a large sample of clinical studies and long-term follow-up. The neonatal outcome was associated with gestational age, and therefore premature delivery was avoided as much as possible during treatment.

Cloning and characterization of a novel betaine aldehyde dehydrogenase gene from Suaeda corniculata

Glycine betaine is an important quaternary ammonium compound that is produced in response to several abiotic stresses in many organisms. The synthesis of glycine betaine requires the catalysis of betaine aldehyde dehydrogenase (BADH), which can convert betaine aldehyde into glycine betaine in plants, especially in halotolerant plants. In this study, we isolated the full-length cDNA of BADH from Suaeda corniculata (ScBADH) using reverse transcriptase-polymerase chain reaction and rapid amplification of cDNA ends. Next, we analyzed the expression profile of ScBADH using real-time PCR. The results showed that ScBADH expression was induced in the roots, stems, and leaves of S. corniculata seedlings under salt and drought stress. Next, ScBADH was overexpressed in Arabidopsis, resulting in the transgenic plants exhibiting enhanced tolerance over wild-type plants under salt and drought stress. We then analyzed the levels of glycine betaine and proline, as well as superoxide dismutase (SOD) activity, during salt stress in WT and transgenic Arabidopsis. The results indicated that overexpression of ScBADH produced more glycine betaine and proline, and increased SOD activity under NaCl treatment. Our results suggest that ScBADH might be a positive regulator in plants during the response to NaCl.

rbcS SRS4 promoter from Glycine max and its expression activity in transgenic tobacco

The regulatory region of the ribulose-1,5-bisphosphate carboxylase small subunit gene SRS4 from soybean (Glycine max) was cloned using TAIL-PCR and general PCR, and named the rbcS promoter. The promoter was fused with the GUS gene and introduced into Nicotiana tabacum via Agrobacterium-mediated leaf disk transformation. In 4-week-old transgenic tobacco plants, the highest GUS expression levels were observed in the leaves, GUS activity was 7.13- and 7.40-fold higher in leaves than in stems and roots, respectively. Moreover, GUS activity was stimulated by light. In conclusion, spatial and light regulation of the soybean rbcS promoter was observed in N. tabacum, thus illustrating a leaf-specific and light-induced promoter.

MiR-29c mediates epithelial-to-mesenchymal transition in human colorectal carcinoma metastasis via PTP4A and GNA13 regulation of β-catenin signaling

BACKGROUND

Distant metastasis is the major cause of cancer-related death, and epithelial-to-mesenchymal transition (EMT) has a critical role in this process. Accumulating evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-29c has been implicated as a tumor suppressor in several human cancers. However, the role of miR-29c in the progression of colorectal cancer (CRC) metastasis remains largely unknown.

PATIENTS AND METHODS

The expression of miR-29c was examined by qRT-PCR in a cohort of primary CRC (PC) and distant liver metastasis (LM) tissues. A series of in vivo and in vitro assays were carried out in order to elucidate the functions of miR-29c and the molecular mechanisms underlying the pathogenesis of metastatic CRC.

RESULTS

miR-29c was markedly downregulated in PCs with distant metastasis and determined to be an independent predictor of shortened patient survival. But LM tissues showed higher levels of miR-29c than that in PC tissues. In CRC cells, miR-29c dramatically suppressed cell migration and invasion abilities in vitro and cancer metastasis in vivo. In addition, miR-29c inhibited EMT and negatively regulated Wnt/β-catenin signaling pathway. Guanine nucleotide binding protein alpha13 (GNA13) and protein tyrosine phosphatase type IVA (PTP4A) were identified as direct targets of miR-29c, which acted through ERK/GSK3β/β-catenin and AKT/GSK3β/β-catenin pathways, respectively, to regulate EMT. Furthermore, significant associations between miR-29c, its target genes (GNA13 and PTP4A) and EMT markers were validated in both PC and LM tissues.

CONCLUSION

Our findings highlight the important role of miR-29c in regulating CRC EMT via GSK-3β/β-catenin signaling by targeting GNA13 and PTP4A and provide new insights into the metastatic basis of CRC.

Clinical effects and safety review of self-expanding stent surgery for extracranial carotid artery stenosis treatment

This study aimed to investigate the clinical effects and safety review of self-expanding stent surgery in the treatment of extracranial carotid artery stenosis. Seventy-eight patients with carotid artery stenosis were applied with the self-expanding stent for endovascular interventional therapy. Eighty-one stents were implanted into 80 blood vessels of the 78 patients, in which protective umbrellas were used in 56 cases, and the success rate of stent implantation was 100%. The stenosis degree decreased from the preoperative (86.72 ± 9.5%) to the postoperative (13.43 ± 5.62%) stage, and the blood peak velocity of the stenosed vessels decreased from 189.58 ± 13.5 to 83.73 ± 5.61 cm/s. Transient blood pressure and heart rate decreases occurred in 21 cases, continuously low blood pressure and heart rate decreasing occurred in 29 cases, and acute occlusion of the ipsilateral middle cerebral artery occurred in 1 case, which was resolved through thrombolysis and thrombus breaking in time. Over-perfusion symptoms were observed in 13 cases, although without serious complications such as cerebral hemorrhage. The follow-up period continued for 6-32 months, and ultrasonography revealed that 77 cases had no stent-restenosis, while 1 case had restenosis. The application of self-expanding stents had good clinical effects, with fewer complications and higher safety for the treatment of extracranial carotid artery stenosis.

Antibacterial and xanthine oxidase inhibitory cerebrosides from Fusarium sp. IFB-121, and endophytic fungus in Quercus variabilis

Two antibacterial and xanthine oxidase inhibitory cerebrosides, one of which is chemically new, were characterized from the chloroform-methanol (1:1) extract of Fusarium sp. IFB-121, an endophytic fungus in Quercus variabilis. By means of chemical and spectral methods [IR, electrospray ionization MS (ESI-MS), tandem ESI-MS, 1H and 13C NMR, distortionless enhancement by polarization transfer, COSY, heteronuclear multiple-quantum coherence, heteronuclear multiple-bond correlation, and 2-D nuclear Overhauser effect correlation spectroscopy], the structure of the new metabolite named fusaruside was established as (2S,2'R,3R,3'E,4E,8E,10E)-1-O-beta-D-glucopyranosyl-2-N-(2'-hydroxy-3'-octadecenoyl)-3-hydroxy-9-methyl-4,8,10-sphingatrienine, and the structure of the other was identified as (2S,2'R,3R,3'E,4E,8E)-1-O-beta-D-glucopyranosyl-2-N-(2'-hydroxy-3'-octadecenoyl)-3-hydroxy-9-methyl-4,8-sphingadienine. Both new and known cerebrosides, although inactive to Trichophyton rubrum and Candida albicans, showed strong antibacterial activities against Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens, with their minimum inhibitory concentrations being 3.9, 3.9, and 1.9 microg/mL, and 7.8, 3.9, and 7.8 microg/mL, respectively. Furthermore, both metabolites were inhibitory to xanthine oxidase, with the IC50 value of fusaruside being 43.8 +/- 3.6 microM and the known cerebroside being 55.5 +/- 1.8 microM.

A prospective evaluation of angiography-guided coronary stent implantation with high versus very high balloon inflation pressure

BACKGROUND

High inflation pressure (HP) after coronary stent deployment has become a standard approach because it has been associated with a decreased subacute stent thrombosis (SAT) rate. However, the impact of HP on long-term outcomes is still unclear. We compared the long-term results of a strategy of increasing HP (>/=12 atm) until the achievement of angiographic success (<20% residual stenosis) with a prespecified very high inflation pressure (VHP) strategy of 20 atm without intermediate inflations.

METHODS AND RESULTS

We conducted a parallel-group, nonrandomized study to evaluate the short- and long-term results in 136 consecutive eligible patients who underwent successful single Palmaz-Schatz stent implantation in vessels >/=3 mm. Major adverse cardiac events (MACE), that is, death, myocardial infarction, and target lesion revascularization (TLR), were monitored for a minimum of 6 months. No significant differences were observed between the two strategies in terms of final minimal lumen diameter (HP, 3.0 +/- 0.5 vs VHP, 3. 1 +/- 0.5 mm) and acute gain (HP, 2.1 +/- 0.7 vs VHP, 2.2 +/- 0.6). The overall rate of subacute stent thrombosis was 0.7%. During a 405 +/- 148-day follow-up, 21 (28.8%) patients in the VHP group and 6 (9. 5%) in the HP group (P =.005) had MACE, with a TLR rate of 27.4% versus 7.9% (P =.009), respectively. By multivariate analysis, the use of VHP increased the odds of long-term MACE by a factor of 3.48 (P =.009). Among patients undergoing TLR, those treated with VHP had a greater lumen loss (HP, 1.83 +/- 0.57 vs VHP, 2.15 +/- 0.36 mm, P =.02) and a more frequent pattern of diffuse restenosis (71% vs 16%, P =.06).

CONCLUSIONS

In our study, the two strategies had similar acute and short-term results, but VHP was associated with a poorer long-term outcome. These data provide a rationale for a less aggressive strategy for stent deployment by optimizing rather than attempting to maximize inflation pressure and stent expansion.

A novel, simple method of functional spleen volume calculation by liver-spleen scan

Spleen enlargement is commonly associated with portal hypertension from cirrhosis and may cause thrombocytopenia. Thus, accurate assessment of spleen size may be helpful in the clinical evaluation. Spleen length is not a precise estimate of spleen size because of the variation in spleen configuration, and spleen volumes measured by edging techniques can be tedious. We present a new method of measuring the functional spleen volume by liver-spleen scan (LSSs), validation experiments and some clinical data.

METHODS

The method involves measurement of the total spleen counts by SPECT and dividing by a representative voxel concentration on a single frame to obtain the organ volume. Validation included phantom studies and clinical evaluation in 443 consecutive patients, including 216 with histologic assessments of chronic liver disease (CLD) and 11 healthy volunteers.

RESULTS

A calibration factor determined from phantoms was used to convert the calculated volume (CV) to the "true" volume (V): V = CV (0.956) - 66.5 (r = 0.9991; P < 0.001). The volume calculations were validated in a second group of phantoms (r= 0.981; P < 0.0001). Spleen volumes were expressed as volume (cm3) and as volume per pound ideal body weight (IBW) (cm3/lb) (the conversion factor to convert cm3/lb IBW to cm3/kg IBW is 2.2). Clinical studies of reproducibility included demonstration of a significant (P < 0.0001) linear correlation between volumes calculated from repeat LSSs within 9 mo of the initial LSS in 11 healthy volunteers and 32 patients with CLD: y = 1.02x - 25; r = 0.968. The correlation with spleen volumes from autopsy or splenectomy was significant: y = 0.766x + 57; r = 0.845; P < 0.001. The normal spleen volume in 11 patients was 201 +/- 77 cm3 and 1.43 +/- 0.68 cm3/lb IBW (upper limits of normal: 335 cm3 or 2.5 cm3/lb IBW). In 443 consecutive LSSs over 15 mo, half of the patients had spleen volumes above the upper limits of healthy volunteers, and CLD was present in 90.9% of these patients. In 216 patients with histologically proven liver disease, a progressive increase in the percentage of spleen volumes above the upper limits of normal was noted from no fibrosis (10%) to mild to moderate fibrosis (36.7%) to early cirrhosis (52%) to advanced liver disease (75%). The correlation of spleen volume with platelet count was excellent (r = 0.7635; P < 0.005).

CONCLUSION

This novel spleen volume measurement detects serious liver disease and correlates with splenic hyperfunction.

Increased ferritin gene expression in atherosclerotic lesions

To identify genes potentially implicated in atherogenesis, a cDNA library was constructed from human atherosclerotic aorta and differentially screened with 32P-labeled-cDNAs prepared from human normal and atherosclerotic aortas. Two cDNA clones exhibiting higher hybridization to the 32P-labeled cDNAs from atherosclerotic vessels were isolated and identified to be genes encoding L-ferritin and H-ferritin, respectively. Northern blot analysis confirmed that the expression of both ferritin genes was notably higher in human and rabbit atherosclerotic aortas than in their normal counterparts. A time-course study illustrated that both L- and H-ferritin mRNAs were markedly increased in aortas of rabbits after feeding with a high cholesterol diet for 6 wk, which was also the time period after which the formation of lesions became evident. In situ hybridization revealed that both L- and H-ferritin mRNAs were induced in endothelial cells and macrophages of human early lesions. The signals were also detected in the smooth muscle cells of advanced lesions. Immunostaining further identified the presence of ferritin protein in atherosclerotic lesions. On the other hand, Prussian blue stain revealed the presence of iron deposits in advanced lesions but not in early human or rabbit lesions. Further experiments with cultured human monocytic THP-1 cells and aortic smooth muscle cells demonstrated that ferritin mRNAs were subjected to up-regulation by treatment with IL-1 or TNF, while TGF, PDGF, and oxidized LDL did not affect the expression of either ferritin gene in both cell lines. Collectively, these results clearly demonstrate that ferritin genes are susceptible to induction in the course of plaque formation.

Diagnosis of myocardial contusion. Quantitative analysis of single photon emission computed tomographic scans

Prior studies from our institution have shown that single photon emission computed tomography is sensitive (100%) in predicting patients at risk for serious arrhythmias. However, the positive predictive value is low (15% to 20%). The purpose of this study was to determine if quantitative analysis of single photon emission computed tomographic defects could improve predictive value. One hundred seventy-five patients with positive single photon emission computed tomographic scans were studied. One hundred two patients developed arrhythmias, 42 of which were ventricular. Arrhythmias were associated with all defect loci and all defect sizes. The incidence of arrhythmias did increase with increasing size. Patients were at risk for arrhythmias up to 72 hours after trauma. The value of single photon emission computed tomography is its ability to predict patients at risk for arrhythmias. This study shows that any single photon emission computed tomographic defect, regardless of location or size, is a significant predictor of arrhythmias.

Frictional properties of dilute block-copolymer solutions and homopolymer solutions. Application to molecular weight determination

An equation for the translational diffusion coefficient of block copolymers in dilute solution has been obtained by modifying Zimm's equation for homopolymers to take into account the existence of dissimilar segments in block copolymers. Illustrative calculations for homopolymers and block copolymers have been made and the results for homopolymers have been compared with experiments and with the calculations of Yamakawa and Fujii. A procedure has been proposed to determine the molecular weight of a block copolymer from measurements of its limiting viscosity number and its sedimentation coefficient or translational diffusion coefficient.