1.Application of Six-minute Walk Test in Acute Stroke Patients
Min LI ; Li WANG ; Mengyu SHI ; Wenxian GAO ; Yufang LIU ; Xuemei WANG ; Weina YU
Chinese Journal of Rehabilitation Theory and Practice 2016;22(9):1097-1100
Objective To apply Six-minute Walk Test (6MWT) in acute stroke patients and analyze the results. Methods From Novem-ber, 2014 to January, 2015, 29 acute stroke patients with multiple or single infarction accepted 6MWT. The distance, distance per minute, blood pressure and heart rate before and after test, adverse events or discomforts during the test were recorded. Weak and fatigue scores were calculated. Results The mean of distance in acute stroke patients was (240.1±17.2) m, that was (46.8±3.3)%of the predicted values in the healthy. Male patients walked (255.4±21.40) m, not different from (214.9±28.4) m in female (t=-1.151, P=0.26). The distance liked to be negatively correlated with age (r=-0.356, P=0.058). The distance was similar in each minute. Weak score was (46.8±3.3)%, fatigue score was mostly between-20 and 20, and no correlation was found between them. Blood pressure and heart rate increased significantly at the end of the test (t>2.476, P<0.05). Few of patients complained mild discomforts. Conclusion 6MWT is safe and suitable for acute stroke patients for physical mobility judgement, but adverse events need to be cared.
2.Clinical effect of Radical TUR-BT combined with intra-arterial chemotherapy for localized muscle-invasive bladder cancer
Yang GAO ; Ming LI ; Zhenfeng SHI ; Mengyu AN
International Journal of Surgery 2019;46(5):305-310,封3
Objective To evaluate the clinical efficacy of Radical TUR-BT combined with intra-arterial chemotherapy in the treatment of stage T2 N0 M0 localized muscle-invasive bladder cancer (MIRC).Methods The clinical data of 91 patients with T2 N0 M0 localized myometrial invasive bladder cancer admitted from January 2010 to December 2015 in the people's Hospital of Xinjiang Uyghur Autonomous Region were retrospectively analyzed,76 cases were males,15 cases were female,average age was 63.2 years old,age range 39-91 years old.Patients were divided into BPT group (n =34) and RC group (n =57) according to different surgical methods.Patients in the BPT group underwent Radical TUR-BT + intra-arterial chemotherapy,and patients in the RC group underwent radical cystectomy + urinary diversion.The median follow-up time,2-year progression-free survival,5-year disease-specific survival rate,overall survival and Karnofsky performance status (KPS) were compared between the two groups.Measurement data were expressed as mean ± standard deviation (Mean ± SD),t test was used for comparison between groups;and Chi-square test was used to compare the count date between groups.Using KaplanMeier method to depict disease-specific survival time in two groups.Quality of life evaluation using Karnofsky score,Evaluate the quality of life and health status of the two groups 3 months before and after treatment.Results The median follow-up time of BPT group and RC group were 35 months and 33 months.The 2-year progression-free rates in the BPT and RC groups were 73.5% and 75.4%,respectively,and the difference was not statistically significant (P =0.758).The 5-year disease-specific survival rates of the two groups were 72.4% and 74.8%,respectively,and the difference was not statistically significant (P =0.780).The overall survival rates of the two groups were 61.8% and 63.2%,respectively,and the difference was not statistically significant (P =0.103).There was no significant difference in preoperative KPS score between the two groups (P =0.652).The KPS score of the BPT group was significantly higher than that of the RC group at 3 months after surgery.The difference was statistically significant(P =0.034).Conclusions For patients with localized MIBC with clinical stage of T2 N0M0.Radical TUR-BT combined with intra-arterial chemotherapy has similar effects to RC.This treatment can effectively improve the prognosis,preserve the bladder,and improve the quality of life for patients.
3.Inhibitory effect of RMT1-10-induced tolerogenic dendritic cells in vitro on high-risk corneal allograft rejection in mice and its mechanism
Min ZHAO ; Liuqing YANG ; Mengyu WANG ; Yu TAO ; Yongyue GUO ; Ruifeng SU ; Jing SHI ; Xiaobo TAN
Chinese Journal of Experimental Ophthalmology 2022;40(8):725-733
Objective:To investigate the inhibitory effect of RMT1-10-induced tolerogenic dendritic cells (Tol-DCs) in vitro on high-risk corneal allograft rejection in mice and its mechanism. Methods:One hundred SPF male BALB/c mice and fifty SPF male C57BL/6 mice were selected.Bone marrow-derived immature dendritic cells (imDCs) obtained from C57BL/6 mice were divided into imDCs group, mature dentritic cells (mDCs) group, RMT1-10 group, and IgG isotype control group.The imDCs in the four groups were cultured with no intervention, lipopolysaccharide, RMT1-10 and lipopolysaccharide, or IgG isotype antibody and lipopolysaccharide for 7 days according to grouping.The expression levels of different phenotypes of DCs including CD11c, CD80, CD86, major histocompatibility complex (MHC)-Ⅱ, T cell immunoglobulin and mucin domain containing molecule (Tim)-4 and CD103 in the four groups were detected by flow cytometry.The concentrations of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) in the DCs supernatants were determined by enzyme-linked immunosorbent assay.A mixed lymphocyte culture system was established, and the stimulation index (SI) of CD4 + T cell proliferation stimulated with DCs was detected by cell counting kit 8 method.Corneal neovascularization was induced by corneal stromal suture in BALB/c mice, and the 80 mice with neovascularization in 4 quadrants growing into the middle and peripheral cornea were used as recipients.The recipient mice were randomized into imDCs group, mDCs group, RMT1-10 group, and IgG isotype control group using the random number table method, with 20 mice in each group.An injection of corresponding DCs (1×10 6 cells/100 μl) was administered to the recipient mice via the tail vein according to grouping.At 7 days following the injection, C57BL/6 mice were used as donors and penetrating keratoplasty was performed.Within one month after the operation, signs of corneal grafts rejection, including opacity, edema and neovascularization, were observed by slit lamp biomicroscopy and scored every day.At 21 days after the operation, 5 recipients selected from each group were subcutaneously injected with naive C57BL/6 splenocytes (1×10 6 cells/100 μl) behind the ear.The delayed type hypersensitivity (DTH) was evaluated by ear swelling at 24 hours after the subcutaneous injection.The use and care of experimental animals complied with the Regulations on the Management of Experimental Animals promulgated by the State Science and Technology Commission.This study protocol was approved by an Ethics Committee of the Affiliated Hospital of Chengde Medical University (No.CYFYLL2020055). Results:Compared with mDCs group, the expressions of CD80, CD86 and MHC-Ⅱ, and the percentage of Tim-4-positive cells in CD11c-positive cells were significantly decreased in RMT1-10 group, showing statistically significant differences (all at P<0.001). The percentage of Tim-4-positive cells were significantly decreased in RMT1-10 group than imDCs group, and the percentage of CD103-positive cells in RMT1-10 group was significantly higher than imDCs group, mDCs group and IgG isotype control group (all at P<0.001). The concentrations of IL-10 and TGF-β in the cell culture supernatant of RMT1-10 group were significantly higher than those of the other three groups, with statistically significant differences (all at P<0.001). There were statistically significant differences in the SI of CD4 + T cell proliferation simulated by DCs ( Fgroup=1 833.00, P<0.001; Fratio=230.40, P<0.001; Finteraction=3.06, P=0.01). The SI of DCs/CD4 + T cells ratio at 1∶5, 1∶10, 1∶20 and 1∶40 were all significantly lower in imDCs group than mDCs group, and were all significantly lower in RMT1-10 group than imDCs group (all at P<0.05). There was a statistically significant difference in corneal graft survival curve among various groups ( χ2=77.69, P<0.001). The survival rate of RMT1-10 group was significantly higher than that of imDCs group ( χ2=9.74, P=0.002), and the survival rate of imDCs group was significantly higher than that of mDCs group ( χ2=31.02, P<0.001). The ear swelling of recipient mice of positive control group, mDCs group, IgG isotype control group, imDCs group and RMT1-10 group was (503.6±17.2), (475.7±17.6), (456.2±18.8), (225.2±39.4), (118.1±12.6), and (106.4±7.4) μm, with a statistically significant difference among them ( F=377.10, P<0.001). The mice ear swelling was more serious in positive control group than mDCs group, more serious in IgG isotype control group than imDCs group, and more serious in imDCs group than RMT1-10 group (all at P<0.05). Conclusions:RMT1-10 can inhibit the rejection of high-risk corneal transplantation in mice, the mechanism of which may be attributed to inducing imDCs to transform into Tol-DCs in vitro and up-regulating the expression of TGF-β and IL-10, which promotes antigen-specific immune tolerance after adoptive transfer, thereby indirectly prolongs the survival of corneal grafts.
4.Causal relationship between sex steroid hormones and myopia:a Mendelian randomization study
Baohua LI ; Zefeng KANG ; Mingming ZHANG ; Xinyue HOU ; Jianquan WANG ; Danyu LI ; Mengyu LIU ; Yipeng SHI
Recent Advances in Ophthalmology 2024;44(12):961-966
Objective To analyze the causal relationship between serum sex steroid hormone levels and myopia with the Mendelian randomization(MR)methods.Methods Sex hormone genetic tools classified by sex were publicly availa-ble summarized statistical data from the Genome-wide association study(GWAS)of the UK Biobank Consortium on sex hormone-binding globulin(SHBG),total testosterone(TT),bioavailable testosterone(BT),and estradiol(E2).The GWAS summarized statistical data for myopia were obtained from publicly available data published by the FinnGen Consorti-um R10.All data were downloaded from April 18 to April 31,2024 from the corresponding databases and analyzed.All re-sults from the MR study were mainly analyzed by inverse-variance weighting(IVW)method.Results The study showed that a higher serum SHBG level in European increased the risk of myopia development in women(IVW,OR=1.152,95%CI:1.014-1.308,P=0.029);low serum TT level(IVW,OR=0.821,95%CI:0.697-0.967,P=0.018)and serum BT lev-el(IVW,OR=0.820,95%CI:0.691-0.972,P=0.022)increased the risk of myopia development in women.There was no causal relationship between serum SHBG,TT,and BT levels and myopia in men.There was no causal effect between E2 level and myopia in women and men.The stability of our findings was supported by sensitivity analysis.Conclusion In-creased serum SHBG level and decreased serum TT and BT levels are associated with an increased risk of myopia in women,whereas no such association is found in men.There is no causal relationship between E2 and myopia.
5.Microwave ablation combined with percutaneous fixation and open decompression treat oppressive spinal metastasis
Shi CHENG ; Jin KE ; Jielong ZHOU ; Xuqiong CHEN ; Mengyu YAO ; Guangtao FU ; Tao YANG ; Yu ZHANG
Chinese Journal of Orthopaedics 2020;40(16):1054-1062
Objective:To evaluate the safety and efficacy of the treatment for oppressive spinal by microwave ablation combined with percutaneous fixation and open decompression.Methods:From January 2015 to September 2018, 20 patients with 26 spinal metastatic were treated with microwave ablation combined with percutaneous fixation and open decompression, including 13 males and 7 females with an average age of 43.85±18.67 years (range, 16-79 years). The locations of the lesions included: 9 in the thoracic, 11 in the lumbar. The tumors' type: myeloma 2 cases, leukemia 1 case, liver cancer 4 cases, osteosarcoma 2 cases, lung cancer 5 cases, kidney cancer 1 case, esophagus cancer 1case, cervical cancer 1 case, intestinal cancer 1 case, prostate cancer 1 case, adenoid cystic cancer 1case. Preoperatively all the patients suffered with the local pain and the spinal cord or nerve root compression symptoms. All 20 cases were examined with CT or MRI to determine the lesions and the sizes of metastasis, as well as to evaluate the ablation zone. The entry of the pedicle screws were performed by Wiltse method through paravertebral muscles. After that the lesions were treated with partial resection for decompression of spinal cord or nerve root, and followed with microwave ablation at the metastasis site. Thermometer was used to monitor the temperature at the central and posterior edges of the vertebral body. The surrounding important tissue were cooled by ice saline. 13 patients were performed with vertebroplasty for enhancement the intensity of the vertebral body. The visual analogue scale (VAS) score was used to evaluate the effect of pain relief after surgery. The postoperative neurological function and performance status were evaluated using Frankel grading and Eastern Cooperative Oncology Group (ECOG).Results:Each lesion was heated for 5.43±2.07 min (range, 3-10 min). The power of microwave ablation was 40-60 W. The mean blood loss during operation was 852.50±514.40 ml (range, 100-1 700 ml). The mean operating time was 4.11±0.99 h (range, 2.5-6.0 h). The temperature inside the lesion was 70-85 ℃. The temperature of the surrounding tissue was maintained at<43 ℃ by repeated frozen saline flush. All cases were followed up for 8.45±2.01 months (range, 6-14 months) without any recurrence. The VAS score of the 20 patients at 48 h, 1 month, 3 months and 6 months after operation were 1.55±1.23, 2.70±0.87, 2.40±1.14 and 3.05±1.00 points, which were all statistically lowerthan the preoperative score 5.95±1.18 ( P<0.05). The Frankel grading of 14 patients had at least one grade improvement 6 months after operation. There were 8 patients shown markedly improved ECOG score 6 months after surgery. Only one case suffered from reduced myodynamiaof lower limb and covered in one month after system treatment. Conclusion:The microwave ablation combined with percutaneous fixation and open decompression could resolve the spinal and nerve compression, relieve the pain in metastatic spinal oppression, reconstruct the stability, and improve the quality of lives, which is a safe and effective palliative surgical method.
6.Survival evaluation and external validation of prognostic scores in postoperative patients with spinal metastasis of lung cancer
Guoqing ZHONG ; Xiaolan WANG ; Jielong ZHOU ; Yue HE ; Longhui ZENG ; Juning XIE ; Huahao LAI ; Yuan YAN ; Mengyu YAO ; Shi CHENG ; Yu ZHANG
Chinese Journal of Orthopaedics 2022;42(24):1605-1614
Objective:To analyze the prognostic factors and evaluate the accuracy of existing survival prediction models in patients with lung cancer-derived spinal metastases who have undergone open surgery.Methods:According to the inclusion criteria, the data of 76 patients with spinal metastasis of lung cancer who underwent open surgery in the department of Orthopedics in Guangdong Provincial People's Hospital were collected from January 2019 to November 2021. The relationship between the number of bone metastasis, pathological type, visceral metastasis, epidermal growth factor receptor mutation, serum alkaline phosphatase (ALP), hemoglobin (Hb), Frankel grade and postoperative survival time in 76 cases was analyzed by Cox logical regression analysis and Kaplan-Meier method to determine the potential prognostic factors. The accuracy of Tomita score, Tokuhashi revised score, Katagiri New score, New England Spinal Metastasis Score score (NESMS) and Skeletal Oncology Research Group (SORG) machine learning algorithm in predicting postoperative survival time was verified by drawing receiver operating characteristic (ROC) curve.Results:The median follow-up time of the patients was 18.0 months (2.3-36.0 months). The median survival time was 12.6 months [95% CI (10.8, 14.4)]. The survival rates at 6 and 12 months after operation were 71.6% and 52.0%, respectively. Multivariate regression analysis showed that ALP [ HR=0.23, 95% CI (0.11, 0.48), P<0.001], Hb [ HR=4.48, 95% CI (2.07, 9.70), P< 0.001] and EGFR mutation [ HR=2.22, 95% CI (1.04, 4.76), P=0.040] were independent predictors of prognosis. The accuracy of Tomita score, Tokuhashi revised score (2005), Katagiri New score and NESMS score in predicting 1-year mortality was 58.7%, 65.7%, 70.5% and 65% respectively, and the accuracy in predicting 6-month mortality was 63.7%, 62.2%, 61.2% and 56.8% respectively. The accuracy of SORG machine learning algorithm in predicting 1-year and 90 d mortality was 81.1%, 67.5%, respectively. Conclusion:No EGFR mutation, ALP>164 U/L and Hb≤125 g/L were risk factors affecting the survival of patients with spinal metastasis of lung cancer. SORG machine learning algorithm has good accuracy in predicting the postoperative survival rate of patients with lung cancer spinal metastasis.
7.Clinical and genetic characteristics of young patients with myeloproliferative neoplasms
Mengyu ZHANG ; Mei BAO ; Dayu SHI ; Hongxia SHI ; Xiaoli LIU ; Na XU ; Minghui DUAN ; Junling ZHUANG ; Xin DU ; Ling QIN ; Wuhan HUI ; Rong LIANG ; Meifang WANG ; Ye CHEN ; Dongyun LI ; Wei YANG ; Gusheng TANG ; Weihua ZHANG ; Xia KUANG ; Wei SU ; Yanqiu HAN ; Limei CHEN ; Jihong XU ; Zhuogang LIU ; Jian HUANG ; Chunting ZHAO ; Hongyan TONG ; Jianda HU ; Chunyan CHEN ; Xiequn CHEN ; Zhijian XIAO ; Qian JIANG
Chinese Journal of Hematology 2023;44(3):193-201
Objectives:To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN) .Methods:In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients.Results:1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion:Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.
8.Autophagy Abnormalities in PCOS and Targeted Treatment with Traditional Chinese Medicine: A Review
Xinxin YANG ; Zhicheng JIA ; Mengyu SHI ; Yongqian LI ; Peixuan WANG ; Ying GUO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(3):313-322
Polycystic ovary syndrome (PCOS) is a common gynecological endocrine and reproductive disorder,with the main clinical manifestations including ovulation failure,insulin resistance,hyperandrogenism,and obesity. Its occurrence and development are closely related to cellular regulatory mechanisms such as apoptosis,autophagy,oxidative stress,and inflammatory response. Autophagy,as a clearance mechanism that maintains cellular homeostasis,plays a crucial role in maintaining the growth,development,and maturation of oocytes. Exploring the mechanism of autophagy during the occurrence and development of diseases can help develop treatment methods for PCOS by regulating autophagy. Studies have shown that autophagy plays an important role in the pathogenesis of PCOS,and it can affect the occurrence and development of PCOS through multiple pathways,levels,and targets. Traditional Chinese medicine (TCM) regulates autophagy in ovarian granulosa cells or endometrium of patients with PCOS by targeting the expression of autophagy signaling pathways,regulatory factors,and non-coding single-stranded RNA molecules,thereby alleviating inflammation,regulating metabolism disorders,and balancing hormone levels in PCOS. Accordingly,TCM can ameliorate pathological conditions such as insulin resistance,hyperandrogenism,and ovulation failure in PCOS. This article summarizes the TCM formulas and extracts for the treatment of PCOS,as well as the main autophagy pathways and regulatory factors involved,aiming to provide reference and suggestions for the future treatment of PCOS with TCM by regulating autophagy.
9.Analysis of image features of fundus blood vessel in healthy human eye based on deep learning techniques
Mengyu HUI ; Jinglin SHI ; Xiaohan YU ; Jian LI ; Yan ZHANG ; Zhengli TANG ; Shanghai YU ; Yue GAO ; Ping LIU ; Hua ZHANG
International Eye Science 2024;24(10):1542-1550
AIM:To explore the fundus vascular characteristics of healthy individuals based on deep learning techniques, with a view to discovering the range of normal values of the fundus arteries and veins, as well as the relationship between physiological factors, such as gender, age, body mass index(BMI), blood pressure, and fundus vasculature characteristics.METHODS:Fundus images of healthy people were taken from a professional fundus camera, and the subject's blood pressure and laboratory test was collected. Additionally, the fundus arteries and veins were segmented by the improved U-Net model, and the color, morphology and Haralick texture features of the vessels were extracted from computer vision technology.RESULTS:A total of 4 487 cases fundus images were taken and 326 cases with healthy and clear fundus images were screened, including 200 males and 126 females. There were differences in the morphology, color, and textural characteristics of the left and right eyes, as well as of the fundus arterioles and veins, with a mean vessel width(width)of 1.146 in the arteries and 1.430 in the veins, and an arteriovenous ratio about 4:5. Fundus artery and vein characteristics in healthy individuals of different ages(21-30, 31-40, 41-50): compared with the healthy population aged 21-30 and 31-40 years, arterial and venous inverse difference moment(idm), f12 and venous angular second moment(asm)values increased, and arterial and venous contrast(con), entropy(ent), difference entropy(den), and venous sum entropy(sen)values decreased in 41-50 years. Compared with the 21-30 years age group, arterial f12 values increased and venous con values decreased in 31-40 years(all P<0.05). Fundus vascular characteristics of healthy individuals of different sexes: compared with male, fundus arterial and venous sum average(sav), sum variance(sva)values, arterial curved values, and venous b mean, bsd, variance(var), sen, ent values increased in female, while venous area value of female decreased(all P<0.05). There were no statistically significant differences in fundus arteriosus and venous features in healthy subjects with different levels of BMI(all P>0.05). Fundus characteristics of healthy people with different degrees of blood pressure: there were statistically significant differences in fundus arteriosus area, width, and venous con, idm, dva, and den values between the normal blood pressure and high blood pressure groups(all P<0.05).CONCLUSION: The characteristics of the left and right eyes as well as the fundus arteries and veins differ in healthy individuals and correlate with physiological factors such as gender, age and blood pressure, which have the value of a potential microcirculation marker.
10.Characteristics of Participants for Developing Emergency Health Systems Guidance Based on AGREE-HS
An LI ; Gezhi ZHANG ; Xue CHEN ; Fangqi LIU ; Danping ZHENG ; Weixuan BAI ; Wei YANG ; Dongfeng WEI ; Nannan SHI ; Mengyu LIU
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(22):157-163
The formulation method of emergency health systems guidance (HSG) is crucial, directly impacting the efficiency and effectiveness of responses in emergencies. A scientifically sound, systematic, and easily executable guidance document can assist health institutions at all levels in quickly coordinating resources, standardizing emergency response processes, and safeguarding public health. This study employed the Appraisal of Guidelines for Research and Evaluation for Health Systems (AGREE-HS) to analyze the characteristics of participants in developing emergency HSGs represented by the COVID-19 emergency HSG. The results showed that in the 34 HSGs included in this study, the item participants received the lowest score. Within this item, criterion 1 (diversity of development group) scored the highest (3.13±1.55), while criterion 5 (prevention of funding agency influence) scored the lowest (1.21±0.47). There were differences (P<0.05) in measures taken to mitigate funding agency influence between the six standard HSGs developed by the World Health Organization (WHO) and the four emergency HSGs. Additionally, differences (P<0.05) existed in the development group members, background, conflicts of interest, and preventive measures between the six WHO standard HSGs and the 34 emergency HSGs, as well as between the HSGs developed by the WHO and those developed by countries. The participants in developing emergency HSGs were influenced by various factors, including limited time for guideline development, modes of participation, scarce evidence, and uncertainties in expected outcomes. There is a need to downplay extensive requirements concerning the composition of group members, institutional diversity, and conflicts of interest, emphasizing the roles of key participants like government officials and professionals who can provide rapid, practical guidance in emergency situations.