Hypoxic preconditioning (HPC) refers to exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that is able to result in a resistance to subsequent severe hypoxia/ischemia in tissues and cells. The effects exerted by HPC are well documented. The original local in situ (LiHPC) is now broadened to remote ectopic organs-tissues (ReHPC) and extended crossly to cross pluripotential HPC(CpHPC) induced by a variety of stresses other than hypoxia/ischemia, including cancer, for example. We developed a unique animal model of repetitive autohypoxia in adult mice, and studied systematically on the effects and mechanisms of HPC on the model in our laboratory since the early 1960s. The tolerances to hypoxia and protection from injury increased significantly in this model. The adult mice behave like hypoxia-intolerant mammalian newborns and hypoxia-tolerant adult animals during their exposure to repetitive autohypoxia. The overall energy supply and demand decreased, the microorganization of the brain maintained and the spacial learning and memory ability improved but not impaired, the detrimental neurochemicals such as free radicals down-regulated and the beneficial neurochemicals such as adenosine(ADO) and antihypoxic gene(s)/factor(s) (AHGs/AHFs) up-regulated. Accordingly, we hypothesize that mechanisms for the tolerance/protective effects of HPC are fundamentally depending on energy saving and brain plasticity in particular. It is thought that these two major mechanisms are triggered by exposure to hypoxia/ischemia via oxygen sensing-transduction pathways and HIF-1 initiation cascades. We suggest that HPC is an intrinsic mechanism developed in biological evolution and is a novel potential strategy for fighting against hypoxia-ischemia and other stresses. Motivation of endogenous antihypoxic potential, activation of oxygen sensing--signal transduction systems and supplement of exogenous antihypoxic substances as well as development of HPC appliances and HPC medicines such as AHFs are encouraged based on our basic research on HPC. HPC may result in therapeutic augmentation of the endogenous cytoprotection in hypoxic-ischemic or suffering from other diseases' patients. Evolutionary consideration of HPC and clinical implications of HPC are both discussed to guide future research. The product of AHF is expected to be one of the most effective first aid medicines to rescue patients in critical condition. HPC is beginning to be used in surgery and is expected to be developed into a feasible adaptive medicine in the near future.
Animals ; Brain ; physiology ; Disease Models, Animal ; Hypoxia, Brain ; physiopathology ; Hypoxia-Inducible Factor 1 ; Ischemic Preconditioning ; Mice ; Signal Transduction

Objective To evaluate the value of combining PCT, BNP, D-Dimer and PCIS score in predicting the prognosis of pediatric severe pneumonia in the early stage. Methods 80 cases of children with severe pneumonia were selected, 49 cases were boys , 31 cases were girls, with a median age of 7.5 months (1 month to 156 months). According to the final outcome, the cases are divided into treatment group and poor prognosis group. The score of PCIS, PCT, BNP and D-dimer within 24 hours after admission were recorded. According to the indicators, ROC curve was drawn independently and integrated with the four indicators,and the corresponding areas under ROC curve (AUC) were calculated to compare the accuracy of the assessment. Results The AUC of PCIS, PCT, BNP and D-dimer were between 0.7 and 0.9. The ROC curve integrated the four indicators showed the AUC were 0.932, which improved sensitivity and specificity. Conclusions The integration of PCIS, PCT, BNP and D-Dimer could improve the accuracy of prediction in the prognosis of severe pediatric pneumonia.

Objective: To understand the epidemiological characteristics of the norovirus epidemics in Haidian District, Beijing Municipality from 2015 to 2022, so as to provide insights into epidemic prevention and control. Methods: The epidemiological characteristics, case data, and laboratory testing of norovirus epidemics were collected in Haidian District from 2015 to 2022, and the temporal distribution, spatial distribution, population distribution, and norovirus detection were analyzed using a descriptive epidemiological method. Results: A total of 208 norovirus epidemics involving 3 530 cases were reported in Haidian District from 2015 to 2022, with a median attack rate of 25.00% (interquartile range, 18.35%). The main pathogens detected were type GⅡ, accounting for 87.98% (183 cases), and the main transmission mode was interpersonal transmission, accounting for 93.27% (194 cases). Norovirus epidemics peaked from March to June and October to December, accounting for 44.71% (93 epidemics) and 44.23% (92 epidemics), and predominantly occurred in schools and preschool institutions, accounting for 51.92% (108 epidemics) and 40.38% (84 epidemics). The median age of norovirus infected cases was 8 (interquartile range, 13) years. There were 1 920 males and 1 610 females, with a ratio of 1.19︰1. The positive rates of case specimens, key population specimens and environment smeared specimens in epidemic units were 74.32%, 13.91% and 5.86%, respectively. Conclusions The norovirus epidemics in Haidian District from 2015 to 2022 was mainly caused by type GⅡ and spread from person to person. The epidemics peaked in winter and spring, and schools and preschool institutions were the key units of prevention and control.

Objective To synthesize 99Tcm- (hydrazinonictinamide- [Lys3] -bombesin) (tricine)(trisodium triphenylphosphine-3,3',3"-trisulfonate) ((HYNIC-[Lys3]-BBS) (tricine) (TPPTS)) and evaluate its biodistribution and binding capability with tumor tissue in Balb/c nude mice bearing human pancreatic cancer xenografts. Methods HYNIC was conjugated to the [Lys3] -BBS at pH = 9.0 with SnCl2 as reducing agent and both tricine and TPPTS as coligands for 99Tcm-labeling. 99Tcm-HYNIC-[Lys3]-BBS)(tricine) (TPPTS) was purified by Sep-Pak C18 cartridge and was analysed by HPLC. The radiochemical purity and radiolabeling yield were measured. The stability of 99Tcm-(HYNIC-[Lys3]-BBS) (tricine)(TPPTS) in serum, biodistribution (% ID/g) in the normal mice and imaging of the Balb/c nude mice bearing human pancreatic cancer xenografts in vivo were studied. Results The radiolabeling yield was (90 ±2)% and the radiochemical purity was over 95%. The radiochemical purity after 4 h in serum was over 85%. The distribution in normal mice showed rapid clearance from blood (the uptake was (0.07 ±0.01) %ID/g at 2 h postinjection). 99Tcm-(HYNIC-[Lys3]-BBS) (tricine) (TPPTS) was excreted mainly via the kidney with little radioactivity accumulation in the liver and gastrointestinal tract (the uptake of liver, stomach, intestine was (0.27 ±0.03), (0.06 ±0.03), (0.04 ±0.00) %ID/g at 2 h postinjection). Marked uptake of radioactivity was found in tumor tissue of the Balb/c nude mice bearing human pancreatic cancer with maximum T/NT ratio of 3.71 ± 0.57 at 2 h postinjection. Conclusions 99Tcm-(HYNIC-[Lys3]-BBS)(tricine) (TPPTS) can be easily prepared with high radiolabeling yield and radiochemical purity. The stability in serum and good biodistribution charateristics make it useful for the diagnosis of human pancreatic cancer with over-expression of the gastric-releasing peptide(GRP) receptor.

Purpose To analyze EGFR exon 18 ~21 gene mutations in lung cancer, and compare xTAG liquidchip technology and Sanger sequencing technology in clinical practice. Methods 1 139 tumor tissue samples from phaseⅠtoⅣlung cancer patients were randomly collected. DNA was extracted from the samples. EGFR gene mutation status in exon 18~21 was detected by xTAG liquidchip technology and Sanger sequencing technology respectively. Results The mutation status of EGFR was obtained by xTAG liquidchip technology in 1 134 patients, and 1 105 by Sanger sequencing technology, detection success rate was 99. 56% and 97. 01% respective-ly. The sensitivity and specificity of xTAG liquidchip technology Comparing with Sanger sequencing was 99. 59% and 94. 54%. Sever-al cases of multiple mutations were detected by both methods. All mutation types detected by two methods are fully consistent. Conclu-sions Comparing with Sanger sequencing technology, xTAG liquidchip technology, which is able to detect mutations of exon 18~21 simultaneously, is more convenient and efficient for EGFR gene mutation detection in lung cancer.

Objective To detect the effect of hypoxia preconditioning on HIF-1α expression in the hippocampus of mice during acute and repeated hypoxia exposures. Methods Mice were randomly divided into 3 groups and were exposed to hypoxia for 4 runs ( H4 group) , 1 run ( H1 group) and 0 run ( control group). RT-PCR, Western blot and EMSA were used to examine the HIF-1α expression in the mouse hippocampus following exposure to hypoxia. Total mRNA,total protein and nuclear protein were extracted from the mouse hippocampus for RT-PCR, Western blot and EMSA respectively. Results HIF-1α mRNA levels were found to be increased in H1 and decreased in H4 (vs H1 ). HIF-1 α protein levels and HIF-1 DNA binding activities were increased in H1 and markedly increased in H4. Conclusion HIF-1 activation may be involved in the protection of the brain of hypoxia-preconditioned mice.

Objective To investigate surgical technique and clinical efficacy of Sky bone ex- pander kyphoplasty in the treatment of osteoporotic vertebral body compression fractures.Methods Eighteen cases with osteoporotic vertebral body compression fractures were treated with Sky bone expander kyphoplasty from August 2004 to November 2005.Under the local anesthesia,3.5-5ml of bone cements were injected into each pathologic vertebral body through unipedicle approach after reduction procedure was done with Sky bone expander.Results The postoperative follow-up ranged from 3 to 11 months, with an average of 4.5 months.Back pain was effectively relieved after the operation in all cases.No complications occurred.Conclusion The Sky bone expander kyphoplasty has the advantages of safe- ty,easy operation,minimal invasion,effective restoration of the vertebral body height and fast relief of pain.

Objective To study the placental vascular distribution of monochorionic (MC) twins with twin-to-twin transfusion syndrome (TTTS) or hirth weight discordance.Methods Twenty-eight MC placentas were injected in Peking University Third Hospital between Feb.2010 and Feb.2011.The vascular distribution type (parallel,crossed,mixed and monoamniotic),the anastomosis of vessels and the placental sharing were recorded.The outcome of pregnancy and the placental characteristics of birth weight discordance (birth weight discordance ≥ 20％) in non-TTTS MC twins were analyzed.Results (1) The outcome of pregnancy:the miscarriage or gestational weeks of 28 MC twins were 20 to 38 weeks (median of 35 weeks).Six cases were TTTS,3 of which received fetoscopic laser occlusion of communicating vessels (FLOC).There were 48 live births,with an average birth weight of (2036 ± 623) g.(2) Type of placental vascular distribution:in the 28 MC placentas,number of parallel,crossed,mixed and monoamniotic type of placental vascular distribution were 4 (14％),14 (50％),6 (21％) and 4 (14％) cases,respectively.No parallel type was found in TTTS.There was no significant difference of vascular anastomosis or unequal placental sharing among the different placental vascular distribution types (P ＞ 0.05).(3) Characteristics of placental vascular distribution in birth weight discordance twins:there were 20 non-TTTS MC twin pregnancies,all of which got live births of both babies.Birth weight discordance equal to or more than 20％ was found in 6 pairs of newborns,while birth weight discordance less than 20％ was found in the rest 14 cases.Ratio of unequal placental sharing was significantly different between the two groups (P ＜ 0.01).There was no significant difference of umbilical cord insertion,placental vascular distribution and anastomosis in the two groups (P ＞0.01).Conclusions Vascular distribution type of MC twins might be related to TTTS.Unequal placental sharing is a risk factor of birth weight discordance in non-TTTS MC twins.

Objective To assess the analytical performance of hs-cTnT and biological variations in healthy population as well as establish hs-cTnT reference intervals. Methods The serum samples from 100 acute myocardial infraction patients and 474 apparently healthy subjects were collected. The functional sensitivity,within- and between-run imprecision were determined. The hs-cTnT assay and con-cTnT assay were evaluated. The serum hs-cTnT levels were detected in apparently healthy subjects to establish reference intervals. Moreover,the long-term and short-term biological variations for hs-cTnT in healthy volunteers were assessed. Results The functional sensitivity of hs-cTnT was 0. 005 μg/L. The within- and between-run precision for lower level control(0. 014 μg/L) and higher level control(2. 500 μg/L) was 2. 97% vs 3. 64%and 0. 66% vs 1.01% ,respectively. The correlation between hs-cTnT assay and con-cTnT assay was good ( R2 =0. 972 ,P ＜0. 01 ). The 99th percentile in apparently healthy subjects was 0. 003 μg/L for women less than60 years, 0.008 μg/L for men less than 60 years, 0.015 μg/L for women above 60 years and 0. 021 μg/L for men above 60 years. The CVa, CVi, CVg and CVt of short-term biological variations in detecting hs-cTnT from 22 apparently healthy subjects were 3.8%, 4. 8%, 49.9% and 58.5%,respectively. The CVa,CVi ,CVg and CVt of long-term biological variations were 5. 3% ,6. 4% ,56. 6% and 68. 3% respectively. Conclusions The analytical performance of the hs-cTnT is better than con-cTnT assay,achieving acceptable level according to guideline. Our experimental result could provide the basis for the new high sensitivity cTnT assay in the diagnosis of acute myocardial infarction.

Brucellosis ; diagnosis ; drug therapy ; Child ; Child, Preschool ; Female ; Humans ; Male