Clinical significance of detecting group B Streptococcus from midstream urine culture / 中国感染控制杂志

Objective To explore the clinical significance and antimicrobial resistance of group B Streptococcus(GBS)isolated from midstream urine culture,aiming to provide a basis for the diagnosis and treatment of clinical urinary tract infection(UTI).Methods Information about GBS strains isolated from midstream urine culture of in-patients and outpatient in a hospital in Nanjing from February 2020 to December 2022 were retrieved through labora-tory information system,strains with complete data were screened out.Case data,urine routine,and antimicrobial susceptibility testing results were reviewed.Results A total of 9 081 non-repetitive bacterial strains were detected from midstream urine culture,including 425 GBS strains,accounting for 4.7％,ranking sixth.Strains with incom-plete data were excluded,a total of 365 patients were included in the study.169(46.3％)were males and 196(53.7％)were females,with an average age of(55.4±15.2)years.365 patients who were detected GBS were from 17 de-partments,with the highest proportion being department of urology(n=237,64.9％).The underlying diseases of patients mainly included hypertension(n=136),diabetes(n=95),urolithiasis(n=120)and urinary tumors(n=98).211 patients underwent urological surgery,all were treated with antimicrobial agents before surgery,and 205 patients underwent indwelling urinary catheters after surgery;9 patients were detected GBS from urine during the middle and advanced stage of pregnancy.36.4％(n=133),38.9％(n=142)and 24.7％(n=90)patients had GBS colony count ≤104 CFU/mL,104-105 CFU/mL,and ≥105 CFU/mL,respectively.Patients with symptoms of UTI accounted for 24.9％(n=91),and asymptomatic bacteriuria accounted for 75.1％(n=274).The incidence of UTI symptoms in males was lower than that in females(19.5％vs 29.6％,P＜0.05).As the GBS colony count in urine culture increased,the proportion of patients with symptoms of UTI showed an upward trend(P＜0.05).On the day of urine culture,the positive rates of urine routine white blood cells,leukocyte esterase,and nitrite were 53.2％,50.1％,and 3.8％,respectively.The positive rates of urine occult blood,leukocyte esterase,white blood cells,and urine protein in patients with symptomatic UTI were all higher than those with asymptomatic bacteriuria patients(all P＜0.05).No GBS were found to be resistant to penicillin,ampicillin,vancomycin,linezolid,and tigecycline.The resistance rate to levofloxacin and moxifloxacin was about 40％,and resistance rate to tetracycline and clindamycin was over 60％.Conclusion GBS isolated from urine is more common in non-pregnant adults,and only a small percentage have symptoms of UTI.The results of urine culture and urine routine should be comprehen-sively judged based on patient's clinical symptoms and signs.GBS in urine is susceptible to multiple antimicrobial agents,and clinical medication should be adopted rationally based on antimicrobial susceptibility testing result.

Establishment and Identification of MDS Mouse Model with Irom Overload / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To establish a MDS mouse model with iron overload and to study the effect of iron overload on MDS.</p><p><b>METHODS</b>The exogenous mutant gene RUNX1-S291fs was inserted into the mice bone marrow mononuclear cell's genome in mice by retrovirus and transplanted into C57BL/6 mice irradiated by Co γ-ray. After 8 weeks,intraperitoneal injection of iron was performed to establish an MDS mouse model with iron overload. After 24 weeks of transplantation, the peripheral blood, bone marrow, femur, liver and spleen of mice were taken, then the morphological characteristics of peripheral blood and bone marrow cells were observed by Wright's staining; the liver, spleen and bone marrow were stained with Prussian blue to observe the iron deposition. The surface antigens of bone marrow cells were detected by flow cytometry. Bone marrow mononuclear cells and spleen tissue proteins were detected by Western blot to confirm the transfection of RUNX1-S291fs gene and expression of protein. The blood routine and transplanted cell chimeric rate of mice were monitored periodically.</p><p><b>RESULTS</b>Compared with the empty plasmid control mice, levels of leukocyte and hemoglobin as well as platelet were decreased in RUNX1-S291fs mutant mice; the peripheral blood cells and bone marrow cells showed pathological hematopoiesis; the liver and spleen enlarged significantly; the tissue structure of femur, liver and spleen was abnormal; the expression of bone marrow cell surface antigens was abnormal. Bone marrow cells and spleen tissue expressed the RUNX1-S291fs protein. Compared with the controlled mice injected with normal saline, iron deposition occurred in the bone marrow, liver and spleen stained with Prussian blue in the mice injected with iron agent.</p><p><b>CONCLUSION</b>Mice engineered to carry exogenous mutant gene RUNX1-S291fs and injected with iron showed pathologic features of MDS and iron overload, resulting in establishing MDS iron overloaded mouse model successfully, which lays a foundation for studying the effect of iron overload on MDS.</p>

Expression and Significance of HIF-1α in Erythropoiesis of Secondary Iron Overload Disease after Irradiation Damage / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the expression of hypoxia inducible factor 1α(HIF-1α) of iron-overloaded in irradiated mice and its effect on erythropoiesis.</p><p><b>METHODS</b>Twenty mice were randomly divided into 4 groups: Ctrl (control group), IR (irradiation group), IO (irradiation + iron overload group), and RAPA (rapamycin treatment group). The iron overload model was verified. The CFU-E (colony forming unit-erythroid) and BFU-E(burst colony forming unit-erythroid) were cultured; flow cytometry was used to detect the ratios of early stage (Ter119CD71) to late stage (Ter119CD71) of primitive erythroblasts; RT-PCR was used to detect the mRNA expression of HIF-1α and its related signal molecules in bone marrow cells.</p><p><b>RESULTS</b>The expression of HIF-1α in IR and IO group was significantly higher than that in Ctrl group, and that in IO group was significantly higher than IR group (P<0.05). The ratio of late stage primitive erythroblasts, the number of CFU-E and BFU-E in both IR and IO group were lower than those in Ctrl group, and those in IO group were significantly lower than those in IR group (P<0.05). Compared with Ctrl group, the expression of HIF-1α related signal pathway molecules in both IR and IO group was significantly decreased (P<0.05). Compared with IO group, the expression of HIF-1α and its related signal molecules in RAPA(mTOR inhibitor) group was decreased significantly (P<0.05), the number of BFU-E was increased significantly(P<0.05).</p><p><b>CONCLUSION</b>Irradiation induces the increase of HIF-1α and the decrease of the ability of hematopoietic colony formation and the ratio of late stage primitive erythroblasts. Iron overload can aggravate the injury. mTOR inhibitor rapamycin can partially alleviate the injury, suggesting that iron overload can lead to injury of erythropoiesis through HIF-1α.</p>

Effects of Iron Overload on the Apoptosis and Function of Splenic CD8+ T Cells in Mice / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of iron overload on apoptosis and function of splenic CD8+ T cells in mice.</p><p><b>METHODS</b>Forty C57BL/6 mice were randomly divided into control groups, Iron overload (IO), IO+NAC and IO+DFX groups. The iron overload model was established by intraperitoneal injection of iron dextran, and saline was injected as the control. The levels of intracellular reactive oxygen species (ROS) and labile iron pool (LIP) were analyzed by measuring the mean fluorescence intensity (MFI) of 2-7 dichlorofluorescein (DCF) or calcein. The ratio of CD8+ T cells and the levels of IFN-γ, TNF-α, Granzyme-B, and perforin in CD8+ T cells were detected by flow cytometry. The CD8+ T cell apoptosis was determined by flow cytometry with Annexin V/PI double staining. Real-time PCR was used to detect the expression of IFN-γ, TNF-α, Granzyme-B, perforin, BCL-2, and bax at mRNA level in CD8+ T cells.</p><p><b>RESULTS</b>Iron overload was found by spleen iron staining and flow cytometry. The level of intracellular ROS in iron overload (IO) groups was higher than that of the control groups (P<0.01). The percentage of CD8+ T cells in spleen from mice with IO was lower than that in control groups (P<0.05). The expression of IFN-γ and Granzyme-B in CD8+ T cells in IO group were lower than that in control group, the expression of IFN-γ and Granzyme-B at mRNA level in CD8+ T cells was lower than that of control group (P<0.05). CD8+ T cell apoptosis in iron overload group was significantly higher than that in control groups (P<0.01); the expression of BCL-2 at mRNA level was lower than that in control group, but the expression of BAX at mRNA level was higher than that in control group (P<0.05). These effects could be reversed after treating iron-overloaded mice with DFX or NAC.</p><p><b>CONCLUSION</b>Iron overload can inhibit the ratio of CD8+ T cells of splenic cells in mice, decrease the expression of IFN-γ, Granzyme-B, increase the apoptosis of CD3+ CD8+/CD8-. These effects may be regulated through increasing the intracellular ROS level, and can be partially reversed after treating iron-overloaded mice with DFX or NAC.</p>

Study on the correlation between contrast-enhanced ultrasonographic characteristics and microvessel density in breast cancer / 中华医学超声杂志（电子版）

Objective To investigate the relation of contrast-enhanced ultrasound ( CEUS ) characteristics and microvessel density ( MVD ) in the breast cancer .Methods From October 2010 to February 2012, 45 cases of patients with breast cancer were studied in Yantai Yuhuangding Hospital , Affiliated to Qingdao University Medical College .All lesions were examined by CEUS before surgery .The blood perfusion parameters such as rising time (RT),peak intensity(PI),time to peak(TTP),wash-in slope (WIS) and mean transit time ( MTT) were obtained by time-intensity curve ( TIC).Immunohistochemical staining for anti-factor CD34 was performed on surgery specimen and the MVD was evaluated .The CEUS characteristics and blood perfusion parameters between different MVD groups of breast cancer were compared.Results In 45 cases of breast cancer,mean MVD was(47.6 ±14.2)/high power field(HPD). Twenty-one cases(46.7%) were classified as high MVD group(MVD>48/HPD) and 24 cases(53.3%) were classified as lower MVD group ( MVD≤48/HPD) .Besides two cases without contrast agent perfusion in CEUS imaging, blood perfusion was observed in 43 cases (95.6%).Heterogeneous enhancement was observed in 25 cases(55.6%).Local blood perfusion defect was observed in 27 cases(60.0%).Irregular shape was observed in 37 cases(82.2%).Centripetal enhancement was observed in 25 cases(55.6%). Penetrating surrounding vessels was observed in 32 cases(71.1%).Poorly-defined margin was observed in 34 cases(75.6%).Compared with the surrounding normal breast tissue ,RT and TTP of center region of neoplasms was shorter[(9.3 ±3.3)s vs (11.1 ±3.7)s and (25.3 ±5.9)s vs (27.5 ±6.4)s],PI was higher[(12.1 ±4.6)dB vs (9.2 ±2.8)dB],WIS was higher(1.0 ±0.4 vs 0.8 ±0.3) and differences were significant(t =-3.001, -4.785,6.987 and 5.438,all P 0.05).Conclusion CEUS characteristics of breast lesions were associated with MVD ,which may reflect the microvessel distributional characteristics of neoplasm and may be one of bases used to evaluate neoplasm angiogenesis .