Thymidine is a commercially useful precursor for production of antiviral compounds such as stavudine and azidothymidine. Biosynthesis of thymidine by Escherichia coli BL21 (DE3) was studied using metabolic engineering methods. The deoA, tdk and udp of the salvage pathway were disrupted from E. coli BL21 to construct BS03 that produced 21.6 mg thymidine per liter. Additional deletion of pgi and pyrL increased the supply of thymidine precursors and the resulting strain BS05 produced 90.5 mg thymidine/L. At last, ushA, thyA, dut, ndk, nrdA and nrdB of thymidine biosynthetic pathway were overexpressed, and the resulting strain BS08 produced 272 mg thymidine/L. In fed-batch fermentation, BS08 accumulated 1248.8 mg thymidine/L. Metabolically engineered strain E. coli has potential applications for thymidine production.
Biosynthetic Pathways ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Industrial Microbiology ; Metabolic Engineering ; Thymidine ; biosynthesis

Objective To investigate the effects of Bifidobacterium infatn ison the expression of in -testinal corticotropin releasing factor ( CRF) receptors and how the peripheral CRF receptors activate mast cells in a murine model of irritable bowel syndrome (IBS).Methods Thirty BALB/c male mice were ran-domly divided into three groups including control group , model group and Bifidobacterium infantis group. The mouse model of IBS was established by using chronic restraint stress .Mice in Bifidobacterium infantis group received daily intragastrical administration of Bifidobacterium infantis for 14 days.Mice in control and model groups were treated with equal volume of saline .Then all mice were killed after the assessment of weight and abdominal withdrawal reflex ( AWR) .The levels of histamine , tryptase and tumor necrosis fac-tor-α( TNF-α) in serum samples were detected by ELISA .The expression of CRF in colonic mucosa was analyzed by immunohistochemistry .The expression of CRF-R1 and CRF-R2 in mast cells and the number of mast cells in colonic mucosa were detected by double immunofluorescence staining assay .The expression of CRF-R1 and CRF-R2 at mRNA level in colon were detected by reverse transcription polymerase chain reac-tion ( RT-PCR) .Results Compared with control group , the levels of histamine , tryptase and TNF-αin pe-ripheral blood samples , the expression of CRF-R1 and CRF-R2 at mRNA level , and the number of mast cells, CRF-R1+mast cells and CRF-R2+mast cells in colonic mucosa were increased significantly in model group (P<0.05), but were remarkably down-regulated with the treatment ofB ifidobacterium infantis (P<0.05).Conclusion Bifidobacterium infantis could reduce the activation of mast cells in a murine model of IBS by inhibiting the expression of CRF-R1 and CRF-R2 in intestinal mast cells .

Objective To explore the effect of narrative therapy on family environment and values in adolescents with emotional disorder.Methods 35 adolescents with emotional disorder and their parents from Affiliated Brain Hospital,Nanjing Medical University were enrolled and treated by narrative therapy.Family environment was assessed using Family Environment Scale-Chinese Version (FES-CV)and was compared between pre-and posttherapy.Results 28 adolescents with emotional disorder and their parents completed therapy.The cohesion,independence,intellectual orientation,active-recreation orientation and organization in FES-CV showed higher scores at post-therapy than at pre-therapy ((6.89 ± 2.56) vs.(4.21 ± 3.21) ; (5.54 ± 1.35) vs.(4.68 ± 1.51) ;(4.75±2.07)vs.(3.50±2.12);(4.07±2.65)vs.(2.50±2.32);(3.68±1.77)vs.(2.50±1.62)respectively).The contradict in FES-CV showed lower scores at post-therapy than at pre-therapy ((2.75 ± 2.44) vs (5.25 ± 2.50)).The values of adolescents with emotional disorder and their parents had a positive change after narrative therapy.Conclusion Narrative therapy is effective on the positive change of FES-CV and values of adolescents with emotional disorder and their parents.

Objective To observe the efficacy of electroacupuncture in improving discomforts during and after oocyte retrieval, for providing scientific and significant clinical evidence for the application of electroacupuncture to oocyte retrieval.Method A hundred and thirty-four outpatients receiving IVF-ET fertility treatment were randomized into a treatment group and a control group, 67 in each group. The two groups both received muscular injection with Sauteralgyl 50 mg. Additionally, the treatment group was also given acupuncture at Baihui (GV20), Uterus (MA-TF, right ear), Tengtong (Extra, right), Sanyangluo (TE8, right), and Zusanli (ST36). When needling qi arrived, Tengtong (Extra) and Sanyangluo (TE8) were connected to SDZ-2 electroacupuncture apparatus. The needles were removed at the end of oocyte retrieval. For patients in the control group, oocyte retrieval was conducted 30 min after injection with Sauteralgyl. The operation duration was recorded; blood pressures before injection and at the end of surgery were measured; discomforts including dizziness, nausea, vomiting, perspiration, dry mouth, palpitation, and abdominal distension during operation were observed; discomforts (dizziness, nausea, vomiting, abdominal pain, and lassitude) 0.5 h, 1.5 h, and 2 h after operation were observed.Result The difference in comparing oocyte retrieval duration was statistically significant between the two groups (P＜0.05); there were significant differences in comparing the occurrence rates of dizziness, perspiration, nausea, and palpitation during operation between the two groups (P＜0.05); there were significant differences in comparing dizziness, vomiting, nausea, abdominal pain, and lassitude between the two groups 0.5 h, 1 h, 1.5 h, and 2 h after operation (P＜0.05). The inter-group differences in dizziness, vomiting, nausea, abdominal pain, and lassitude were statistically significant after operation (P＜0.05).Conclusion Electroacupuncture is effective in relieving discomforts during and after oocyte retrieval under transvaginal ultrasound.

Objective To investigate the utility of diffusion weighted imaging (DWI) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the assessment of renal hypoxia in an experimental model of mice with lupus nephritis (LN).Methods MRL/lpr mice (n=13) were studied and C57BL/6 mice (n=10) served as controls.Urinary albumin to creatinine ratio (ACR),serum creatinine (Scr),anti-ds-DNA antibody,and complement C3 levels were measured.The mice underwent coronal echo-planar DWI and BOLD MRI of the kidneys when they were 14-16 weeks old.Hypoxyprobe was administered intraperitoneally to the mice 1 hour before they were sacrificed.The distribution of HypoxyprobeTM-1,hypoxia-inducible factor 1 α (HIF-1 o) and heme oxygenase-1 (HO-1) in renal tissues was detected by immunohistochemical analysis and Western blotting.Results Urinary ACR,Scr and anti-ds-DNA antibody levels in MRL/lpr mice were significantly higher than that in C57BL/6 mice.It was found that HypoxyprobeTM-1,HIF-1o and HO-1 distributed widely in the renal tissue of MRL/lpr mice,and closely associated with the renal tubulointerstitial lesion.The mean apparent diffusion coefficient (ADC) value of kidneys in MRL/lpr mice was (1.52±0.27) × 10-3 mm2/s,and the mean R2* values of the renal cortex and medulla were (30.95 ±4.59)/s and (23.43± 3.06)/s respectively,all significantly lower than that in C57BL/6 mice (P=0.037,P=0.030 and P=0.043,respectively).The ADC of medulla was negatively correlated with urinary albumin to creatinine ratio (r=-0.364,P=0.032;r=-0.329,P=0.050),the ADC of cortex was negatively correlated with the level of serum creatinine (r=-0.814,P=0.014;r=-0.755,P=0.031) when b value was 500 s/mm2 and 800 s/mm2,and the mean R2* value was negatively correlated with the degree of tubulointerstitial lesions and the expression of hypoxia parameters (all P ＜ 0.05).Conclusions Renal hypoxia may play an important role in renal tubulointerstitial lesion.Functional MRI may be used to monitor renal function changes,pathological injuries and renal hypoxia in LN.

Objective: To investigate the status of iodine nutrition and prevalence of goiter among children at ages of 8 to 10 years in Zhejiang Province in 2021, so as to provide insights into the management of iodine deficiency in children. Methods : A total of 90 counties (districts) were sampled as field survey sites from 11 cities of Zhejiang Province using a multi-stage stratified random sampling method in 2021, and non-residential children at ages of 8 to 10 years in these sites were sampled as study subjects. Subjects' household edible salt samples and random urine samples were collected. The iodine content in salt and urinary iodine level were determined using the direct titration method and arsenic-cerium catalytic spectrophotometry for evaluation of iodine nutrition among children. In addition, the lateral lobe of the thyroid gland was measured using ultrasound, and the prevalence of goiter was estimated. Results: A total of 19 363 children were recruited, including 9 710 male children and 9 653 female children, with a male to female ratio of 1.01︰1, and there were 10 704 urban children (55.28%) and 8 659 rural children (44.72%), 9 149 children living in coastal areas (47.25%) and 10 214 children in inland regions (52.75%). The mean iodine content was (19.79±9.25) mg/kg in salt, and the coverage of qualified iodized salt (15 252) was 78.77%. The coverage of qualified iodized salt was significantly lower in urban children than in rural children (76.70% vs. 81.21%; χ2=68.301, P<0.001), and was lower in children living in coastal regions than in inland regions (68.05% vs. 88.27%; χ2=1 270.769, P<0.001). The median urinary iodine concentration was 195.1 μg/L, and the household iodine content in salt correlated positively with urinary iodine concentration in children (rs=0.383, P<0.001). There were 2 885 children with iodine deficiency (14.90%), 7 137 children with adequate iodine (36.86%), 5 414 children with excessive iodine intake (27.96%), and 3 927 children with iodine overdose (20.28%), and the distribution of iodine nutrition in children varied significantly in regions (χ2=283.277, P<0.001) and gender (χ2=126.349, P<0.001). The prevalence of goiter was 2.45% among 7 195 children receiving ultrasound examinations, and a higher prevalence rate of goiter was detected in urban children than in rural children (2.76% vs. 2.00%; χ2=3.962, P=0.047). Conclusions The overall urinary iodine nutrition was adequate among children at ages of 8 to 10 years in Zhejiang Province in 2021, and the prevalence of goiter in children fell within the threshold defined in the criteria of elimination of iodine deficiency. However, the supervision of the iodized salt quality remains to be improved and iodine deficiency control remains to be reinforced.

Objective To detect the modification levels of H2AKll9 ubiquitination (H2AK119ub) and H2BK120ub,and to analyze the relationship between the levels of H2AK119ub,H2BK120ub and arsenic exposure.Methods A cross-sectional study was conducted in typical areas of drinking water type of endemic arsenicosis in Shanxi and Jilin provinces.Totally 281 residents who had drank local water for more 10 years were enrolled in this study,these participants were divided into control group (water arsenic content ＜ 0.01 mg/L),low arsenic exposure group (water arsenic content ranged 0.01-0.05 mg/L),medium arsenic exposure group (water arsenic content ranged ＞ 0.05-0.10 mg/L) and high arsenic exposure group (water arsenic content ＞ 0.10 mg/L).Among them,including 60 subjects in control group (20 males and 40 females),61 subjects in low arsenic exposure group (27 males and 34 females),50 subjects in medium arsenic exposure group (17 males and 33 females),and 110 subjects in high arsenic exposure group (40 males and 70 females).Drinking water and urine samples were collected and the arsenic content was detected by the method of atomic fluorescence spectrometry.After extracting leukocytes histone from the peripheral venous blood that collected from the subjects,the levels of H2AK119ub and H2BK120ub were detected by dot blotting.The levels of water arsenic,urinary arsenic,water arsenic accumulative intake,H2AK119ub and H2BK120ub were expressed as medium and quartile [M (P25,P75)].Results Age,body mass index (BMI),gender,smoking and alcohol drinking between control group and water arsenic exposure groups had no statistical differences (x2 =3.780,3.572,1.938,4.937,6.025,all P ＞ 0.05).Compared the contents of water arsenic [0.005 (0.003,0.006),0.024 (0.017,0.037),0.076 (0.057,0.084),0.150 (0.124,0.185) mg/L],the contents of urinary arsenic [0.011 (0.006,0.017),0.018 (0.004,0.072),0.061 (0.032,0.124),0.134 (0.069,0.223) mg/L],the water arsenic accumulative intake [0.342 (0.248,0.477),1.641 (1.012,2.324),5.273 (3.690,7.036),7.716 (5.608,12.053) mg] among the control,low,medium and high arsenic exposure groups,the differences were statistically significant (Hc =256.041,88.615,218.610,all P ＜ 0.01).Compared the levels of H2AK119ub [1.231 (0.856,1.817),1.244 (0.792,1.884),1.376 (0.743,1.981),1.390 (0.906,2.045)],H2BK120ub [0.350 (0.186,0.589),0.363 (0.152,0.678),0.428 (0.134,0.788),0.276 (0.146,0.453)] in human peripheral blood leukocytes among control,low,medium and high arsenic exposuregroups,the differences were not statistically significant (Hc =2.130,4.330,all P ＞ 0.05).There were no correlations between H2AK119ub and water arsenic content,water arsenic accumulative intake (r =0.104,-0.008,all P ＞ 0.05);there was a positive correlation between H2AK119ub and urinary arsenic content (r =0.166,P ＜ 0.05).There were negative correlations between H2BK120ub and water arsenic content,water arsenic accumulative intake (r =-0.183,-0.159,all P ＜ 0.05);there was no correlation between H2BK120ub and urinary arsenic content (r =-0.101,P ＞ 0.05).There was a negative correlation between H2AK119ub and H2BK120ub (r =-0.127,P ＜ 0.05).Conclusion External exposure to arsenic may change the levels of H2BK120ub in human peripheral blood leukocytes.

Objective:To summarize the clinical features and treatment of pneumocystis jirovecii pneumonia(PCP) in children with non-human immunodeficiency virus(HIV) infection.Methods:A retrospective study was performed on seven cases of severe PCP children with non-HIV infection who were admitted to PICU of The University of Hong Kong-Shenzhen Hospital and PICU of Xianyang Rainbow Hospital from May 1, 2015 to May 1, 2021.The risk factors, clinical manifestations, laboratory results, pulmonary radiological features, treatment and outcomes were observed.Results:Seven children with PCP, including four males and three females, aged from 13 months to 85 months[(42.4±26.8) months], were all associated with underlying diseases, and most of which was hematological malignancies.Six children had a history of using TMP-SMX for PCP prevention, but four of them stopped by themselves and infected PCP in 2 to 4 weeks.All children had hypoxic respiratory failure, whose OI was 30.6±3.4, and presented with fever, dry cough, progressive dyspnea but no lung rales in the early stage.LDH[(745.7±317.0) U/L] and β-D-glucan[(513.8±225.0) pg/mL] increased in all patients.Chest CT showed diffused interstitial changes in bilateral lung fields associated with multiple exudative lesions.Among the anti-Pneumocystis Jirovecii treatment regimens, all cases began the treatment in the first three days during the admission, five cases were treated with intravenous TMP-SMX, and two cases were treated with oral TMP-SMX + caspofungin, with a course of 21 days.All children were also treated with glucocorticoid at the same time.Three days after the treatment of PCP, two children were worsened and one of them died, while another one started to recover on the 6th day of the regimen.The remaining five cases began to show clinical improvement after 3~7 days of PCP treatment.Finally six children were cured and one was died.Conclusion:PCP infection of children without HIV has high risk of destruction in immune system.TMP-SMX can prevent PCP effectively.In the severe PCP cases, early commencement of intravenous TMP-SMX can reduce the mortality rate.In the absence of intravenous TMP-SMX, oral TMP-SMX can be used with caspofungin.

Objective:To evaluate the current situation of prevention and control of iodine deficiency disorders (IDD), and to describe the iodine nutrition level of pregnant women in key population in Zhejiang Province.Methods:In 2021, a cross-sectional survey on iodine nutrition status of the population was conducted in all 90 counties (cities, districts) in Zhejiang Province. Each county (city, district) was divided into five districts: east, west, south, north, and central. One township (street) was selected from each district, and 20 pregnant women were selected from each township (street) to collect edible salt samples and one random urine sample for salt and urinary iodine testing. The above indicators were stratified and analyzed according to urban, rural, coastal, inland, early pregnancy, mid pregnancy, and late pregnancy.Results:A total of 9 679 pregnant women's salt samples were tested, with a salt iodine content of (20.2 ± 9.2) mg/kg, an iodized salt coverage rate of 84.2% (8 153/9 679), and a qualified iodized salt consumption rate of 80.4% (7 785/9 679). Among them, the qualified iodized salt consumption rate of pregnant women in coastal areas was 69.4% (3 175/4 575), significantly lower than that in inland areas [90.3% (4 610/5 104)]; and the proportion of non iodized salt consumption in coastal areas [25.8% (1 181/4 575)] was significantly higher than inland areas [6.8% (345/5 104)]. A total of 9 679 pregnant women's urine samples were tested, with a median urinary iodine of 133.0 μg/L ( < 150 μg/L). In urban areas, the median urinary iodine (129.8 μg/L) was lower than that in rural areas (135.0 μg/L). Likewise, the median urinary iodine was 126.0 μg/L, lower than inland areas (140.3 μg/L). And as pregnancy progressed, the iodine nutrition level of pregnant women gradually decreased (the median urinary iodine: 137.0 μg/L in early pregnancy, 134.1 μg/L in mid pregnancy, and 129.4 μg/L in late pregnancy).Conclusion:In 2021, pregnant women in Zhejiang Province are in a state of iodine deficiency, and there is a greater risk in urban areas compared to rural areas and coastal areas compared to inland areas.

Objective: To improve the understanding of high calcium risk in patients with diffuse large B-cell lymphoma (DLBCL) during the chemotherapy. Methods: The diagnosis and treatment of high calcium risk in one patient with DLBCL during the chemotherapy in the Second Affiliated Hospital of Anhui Medical University was retrospectively analyzed, and the relevant literatures were reviewed. Results: A 52-year-old man who was diagnosed with DLBCL (non-specific, non-germinal center source; stage Ⅳ group A; International prognosis index score 4 points, high-risk group) in June 2017. Two times R-CHOP chemotherapy was performed before diagnosis. This patient was admitted to the hospital for the third chemotherapy, and the disease assessment showed that the enlarged lymph nodes were not significantly smaller than before, and the tumor burden was still high. Therefore, the chemotherapy regimen was adjusted to R-GDP regimen. However, on the 8th day after the end of rituximab treatment, the patient had head pain, which might be related to the patient's poor sleep and primary invasion of the primary disease (blood calcium: 2.94 mmol/L). And then the ibuprofen and diuresis treatments were given, but the symptoms were still gradually worsening, and vomiting appeared on the 9th day, systemic fatigue with drowsiness and irritability appeared on the 12th day. Review blood calcium: 5.02 mmol/L. Adequate fluid hydration, diuretic, renal replacement treatments were given, and the level of blood calcium gradually returned to normal. Finally, the patient's symptoms were improved significantly, and he successfully completed R-GDP chemotherapy. Conclusion If a DLBCL patient has symptoms such as headache, lethargy, irritability or even coma during the chemotherapy, it is necessary to alert the possibility of hypercalcemia and to timely improve the relevant examination and make symptomatic treatment.