Analysis of the negative rate of D-dimer and its influencing factors in patients with acute aortic dissection / 中华急诊医学杂志

Objective:To determine the epidemiological characteristics of acute aortic dissectionand the negative rate of D-dimer of type A and B acute aortic dissection, and to explore the factors related to the negative rate of D-dimer with onset time≤ 24 h.Methods:The study retrospectively analyzed the age, sex, clinical manifestations, medical history, and laboratory test data of patients with acute aortic dissection in the Emergency Department of Xiangya Hospital of Central South University from September 1, 2017 to August 31, 2020. Exclusion criteria included 1) aortic aneurysm, 2) intermural aortic hematoma, 3) penetrating aortic ulcer, and 4) patients with prior aortic dissection, but no new hairclip was shown on this CTA. Stanford typing was used for aortic dissection. The patients were divided into two groups for analysis: onset time ≤ 24 h and onset time in 1-14 days. All statistical analyses were performed using GraphPad Prism 9. Student t-test was used for normal distribution and Mann-Whitney U test for non-normally distributed continuous variables. Comparisons of ratios between groups were performed using the χ2 test or Fisher's exact test. Binary logistic regression analysis was performed to identify independent factors related to the negative rate of D-dimer. A P<0.05 was considered statistically significant. Results:A total of 352 patients with acute aortic dissection were included in this study. Male patients accounted for 79.26%, patients with a history of hypertension accounted for 70.45%, and the ratio of patients with type A:B acute aortic dissection was 2:3. The overall negative rate of D-dimer was 13.64%. The negative rate of D-dimer of type A acute aortic dissection (7.09%) was significantly lower than that of type B acute aortic dissection (7.09% vs. 18.01%, P=0.004). A total of 17 patients died in the emergency department, with an overall mortality rate of 4.83%. The mortality rate of type A acute aortic dissection patients was significantly higher than that of type B acute aortic dissection ( P<0.05). A total of 235 patients (66.76%) with acute aortic dissection had an onset time of ≤24 h. In the hyperacute phase of ≤24 h, there were no statistically significant differences in sex, age, underlying diseases, and vital signs between the normal and elevated D-dimer groups ( P>0.05). In the laboratory test results, the levels of platelet, blood urea nitrogen, creatinine, lactate dehydrogenase, myoglobin, fibrin degradation product, prothrombin time and international normalized ratio of patients in the normal D-dimer group were significantly lower than those in the elevated D-dimer group ( P<0.05). Binary logistic regression analysis showed that the level of FDP was closely related to D-dimer ( P<0.001). Conclusions:The negative rate of D-dimer of type A acute aortic dissection was significantly lower than that of type B acute aortic dissection, but the mortality rate of patients with type A acute aortic dissection was significantly higher than that of type B acute aortic dissection, and the level of FDP was closely related to D-dimer.

Discrete simulation analysis of COVID-19 and prediction of isolation bed numbers

The outbreak of COVID-19 has caused tremendous pressure on medical systems. Adequate isolation facilities are essential to control outbreaks, so this study aims to quickly estimate the demand and number of isolation beds. We established a discrete simulation model for epidemiology. By adjusting or fitting necessary epidemic parameters, the effects of the following indicators on the development of the epidemic and the occupation of medical resources were explained: (1) incubation period, (2) response speed and detection capacity of the hospital, (3) disease cure time, and (4) population mobility. Finally, a method for predicting the reasonable number of isolation beds was summarized through multiple linear regression. The prediction equation can be easily and quickly applied to estimate the demanded number of isolation beds in a COVID-19-affected city. A detailed explanation is given for the specific measurement of each parameter in the article.

Triaging patients in the outbreak of the 2019 novel coronavirus

In the end of 2019, the epidemic of a new coronavirus (SARS-CoV-2) occurred in Wuhan and spread rapidly. Changsha, a city located south to the epicenter, was soon impacted. To control the transmission of the coronavirus and avoid nosocomial infection, triage procedures based on epidemiology were implemented in a local hospital of the city. This retrospective study analyzed the data collected during the triage period and found that COVID-19 patients were enriched seven folds into the Section A designated for rapid detection and quarantine. On the other side, roughly triple amounts of visits were received at the Section B for patients without obvious epidemiological history. Eight COVID-19 cases were spotted out of 247 suspected patients. More than 50% of the suspected patients were submitted to multiple rounds of nucleic acid analysis for SARS-CoV-2 infection. Of the 239 patients who were diagnosed as negative of the virus infection,188 were successfully revisited and none was reported as a COVID-19 case. Of the eight COVID-19 patients, three were confirmed only after multiple rounds of nucleic acid analysis. Besides comorbidities, delayed sharing of epidemiological history added another layer of complexity to the diagnosis in practice. While SARS-CoV-2 epidemic is being alerted in many countries, our report will be helpful to other colleagues in rapid identification of COVID-19 cases and controlling the transmission of the disease.

Application of positron emission tomography in detection of myocardial glucose metabolism in rabbit cardiac arrest models / 中南大学学报(医学版)

To investigate the changes of myocardial glucose metabolism in rabbit cardiac arrest models and the effect of hydrogen intervention by 18F-fluroro-2-deoxyglucose (18F-FDG) positron emission tomography (PET) imaging.
 Methods: Fifteen male New Zealand white rabbits were randomly divided into a hydrogen group (n=6), a control group (n=6) and a sham group (n=3). Cardiac arrest (CA) was induced by intravenous injection of potassium chloride. Conventional cardiopulmonary resuscitation (CPR) was initiated after five-minutes CA. The hydrogen group and the control group were mechanically ventilated into mixed gas with 4% hydrogen+96% oxygen and pure oxygen, respectively, for 30 minutes after CPR. Rats in the sham group was performed the same surgical procedure and was injected adrenaline and potassium chloride but did not induce CA. The vital signs at basic state and 30 min after return of spontaneous circulation (ROSC) were recorded in each group. The parameters of CPR were recorded in two CA groups. Myocardial glucose metabolism was assessed by positron emission tomography (PET) at basic state, 2 h and 24 h after ROSC. The maximum standardized uptake value (SUVmax) of 18F-FDG was measured.
 Results: There were no significant differences in the basal body weight and vital signs among the three groups. There was no significant difference in the blood glucose level before PET examination. The 18F-FDG SUVmax in the sham group at three time points was not significantly changed. In the hydrogen group and the control group, the 18F-FDG SUVmax at 2 h after ROSC were significantly higher than the basic level (1.89±0.47 vs 3.47±1.24 and 1.90±0.36 vs 4.26±0.80, respectively). Compared with the control group, the 18F-FDG SUVmax in the hydrogen group was lower at the point at 2 h after ROSC. The 18F-FDG SUVmax in the 2 CA group were down to the basic level at 24 h after ROSC (hydrogen group 2.02±0.64, control group 2.07±0.61).
 Conclusion: Myocardial glucose metabolism in CA rabbits was increased significantly after ROSC, and hydrogen intervention can reduce the degree of glucose metabolism.

A study on the relationship between intrauterine infection and early-onset neonatal sepsis / 中国新生儿科杂志

Objective To study the relationship between intrauterine infection and early neonatal sepsis.Method From October 2015 to September 2016,the clinical data of pregnant mothers and their newborns in Shenzhen Longhua District Central Hospital were collected,and data of Shenzhen People's Hospital from January 2016 to June 2016 were collected.100 pairs of pregnant mothers and their newborns with confirmed or suspected intrauterine infection were selected as the observation group,and another 100 pairs without intrauterine infection during the same period as the control group.The ratio of term infants vs.premature infants was 1∶ 1.The complete blood count (CBC),CD64,procalcitonin (PCT) and C-reactive protein (CRP) were measured in peripheral blood of all mothers on the day of delivery.The CBC,CD64,CRP,PCT,blood culture of both umbilical venous blood and peripheral blood in neonates were examined and the pathological examination of placenta was performed.Result The positive rate of placental pathology and umbilical cord blood culture in observation group were significantly higher than that in the control and the positive rate in preterms was higher than the terms in observation group (P ＜ 0.05).No significant differences existed between term and premature newborns on the positive rate of peripheral blood culture (P ＞ 0.05).The positive rate of blood culture from umbilical cord blood was higher than peripheral blood in observation group (P ＜ 0.05),but no significant difference in control group (P ＞ 0.05).The incidence of septicemia in term and premature newborns in observation group was significantly higher than the control group (P＜ 0.05).The CD64,PCT in mother's peripheral blood and umbilical cord blood,and CRP in mother's blood were all higher than the control group,the differences were statistically significant (P ＜ 0.05),but CRP in umbilical cord blood in both group were similar (P ＞ 0.05).The area under ROC curve of CD64 and PCT in mother's peripheral blood,CD64 and PCT in umbilical cord blood to diagnose early-onset septicemia in newborns was 0.755,0.793,0.852 and 0.811,respectively.Conclusion The risk of neonatal infections is significantly increased because of intrauterine infection.Combination of peripheral and umbilical blood cultures can increase the accuracy of sepsis diagnosis.Both CD64 and PCT in umbilical cord blood and maternal blood can be used as indicators of intrauterine infection with a predictive value in the diagnosis of early-onset neonatal sepsis.

The relationship between myocardial perfusion and left ventricular longitudinal systolic function in patients with coronary slow flow / 中华超声影像学杂志

Objective To investigate whether myocardial perfusion impairment and left ventricular (LV) longituadinal systolic dysfunction had happened in patients with coronary slow flow(CSF),and to assess the relationship between them by myocardial contrast echocardiography(MCE) and speckle tracking imaging(STI).Methods A total of 55 patients underwent coronary angiography for angina were enrolled,of those 35 with coronary slow flow phenomenon as CSF group,20 patients with normal coronary angiography as control group.STI and MCE were performed from the apical 4-,3 and 2 chamber views at baseline and after low-dose dobutamine stress echocardiography (LDDSE) in CSF group and control group.STI derived LV global longitudinal strain(GLS) and GLS amplitude of variation(△GLS),and MCE derived myocardial blood flow(MBF),and myocardial flow reserve (MFR) were obtained.And the correlation between GLS/△GLS and MBF/MFR was analyzed.Results At baseline,the GLS and MBF were similar between CSF group and control group(P ＞0.05).After LDDSE,both GLS and MBF were significantly increased in two groups (P ＜0.05).The GLS,△GLS,MBF,and MFR in CSF group were significantly lower than those in control group(P ＜0.05).There was no significant correlation between GLS and MBF at baseline in the CSF group(r =-0.274,P =0.111).However,after LDDSE significant correlation existed between GLS and MBF(r =-0.630,P =0.000).Conclusions LV longituadinal systolic function is impaired in patients with CSF under dobutamine stress test,the impairment of MBF and MFR could be an important contributor to the decrease of LV longituadinal systolic function.

Experimental research of cerebral protective effect of mild hypothermia by semiconductor cooling device on the liver surface in rabbits after cardiac arrest / 中华危重病急救医学

Objective To observe the cerebral protective effect of mild hypothermia by semiconductor cooling device on the liver surface in rabbits after cardiac arrest (CA). Methods Eighteen healthy male New Zealand white rabbits were randomly and equally divided into CA control group, ice saline group and semiconductor group. CA was induced by rapid intravenous injection of potassium chloride. Five minutes after onset of CA, CPR was initiated. Compared to the control group, which was not treated by hypothermia intervention after CPR, the ice saline group was treated by 4 ℃ ice saline infusion and the semiconductor group was treated by the semiconductor refrigeration piece device cooling on the liver surface for hypothermia intervention after CPR. We recorded the changes of temperature (tympanic temperature and anus temperature), heart rate (HR), mean arterial pressure (MAP) of rabbits in each group, neurological deficit scores (NDS) at 24, 48, 72 hours after the return of spontaneous circulation (ROSC) and the changes of serum neuron specific enolase (NSE) by enzyme linked immunosorbent assay (ELISA). Pathological changes of the hippocampus tissue, liver tissue and skin tissue were obtained by HE staining. Results There was no significant difference in ROSC time in each group. Two rabbits died at 55 hours and 67 hours after ROSC respectively in the control group. The remaining rabbits survived to 72 hours after challenge. There was no significant difference in the overall survival time in groups. Two hypothermia intervention groups had significantly lower level of serum NSE at 24 hours after ROSC and lower DNS scores at 24, 48, 72 hours after ROSC than control group. And the level of serum NSE after 24 hours of ROSC in the semiconductor group were significantly lower than the ice saline group (μg/L: 6.916±1.161 vs. 8.615±1.430, P < 0.05). DNS scores at 24, 48, 72 hours after ROSC in the semiconductor group were all significantly lower than the ice saline group (scores: 1.33±0.52 vs. 2.00±0.01, 1.01±0.41 vs. 2.00±0.01, 0.92±0.40 vs. 2.10±0.52 respectively, all P < 0.05). Two hypothermia intervention groups had more minor damage of neuronal cell in hippocampus than the control group. And the semiconductor group had more minor damage than the ice saline group. There were no obvious hepatic and subcutaneous tissue injury through which the semiconductor induced hypothermia was performed at corresponding liver surface skin. Conclusion The hypothermia by semiconductor cooling device on the liver surface is a new safe way of protecting brain tissue after CA, which has better cerebral protective effect than ice saline infusion.

Clinical Significance of FLT3 in patients with AML / 现代检验医学杂志

Objective To explore the expression of FLT3 on the cells from acute myeloblastic leukemia (AML)and its clinical signficance.Methods The expression of FLT3 from 80 AML cases was measured by FISH.All cases were indentified by karyotyping,40 cases were normal karyotye,and the other 40 cases were abnormal.Results The FLT3 expression level was different in different AML cases.The expression rate in normal karyotype cases was 5.0%,but in abnormal cases 30.7%,in refractory relapse cases 43.3%,in continual complete remission cases 4.5%.The patients’DFS (Disease-Free survival)and OS (overall survival)without FLT3 expression were 65% and 86% in 24 months’following investigation,but the patients’ DFS and OS with FLT3 expression were 20% and 40% respectively.The difference was distinct between them(P<0.05). Conclusion FLT3 can be thought as a new marker for worse prognosis of AML patients,and its expression level is associat-ed with maglignacy-grade.

Effects of antisense oligonucleotides targeting miRNA-214 on human leukemia U937 cells / 白血病·淋巴瘤

Objective To explore the inhibitory effect of anti-miRNA-214 oligonucleotide on leukemia U937 cells.Methods U937 cells were transfected with anit-miRNA-214 oligonucleotide,cell viability was analyzed by MTT assay.Apoptosis was detected by flow cytometry.The expression of miRNA214 in the U937 cells were measured by real-time PCR.Results The MTT result showed that the growth of U937 cells treated with AMO-miRNA-214 in 24 h,48 h,72 h was obviously inhibited (0.812±0.001,0.770±0.002,0.541±0.001),compared with those in control groups (randomized control 1.011±0.002,1.112±0.003,1.111±0.003,blank control 1.112±0.001,1.023±0.001,1.101±0.001),the differences had statistical significance (F =2.782,3.659,2.735,P =0.021,0.018,0.036).The flow cytometry results showed that the apoptosis detected in AMO-miRNA-214 group at 48 h,72 h (15.12±0.02,19.14±0.01) had significant differences compared with those in control groups (randomized control 2.04±0.02,2.45±0.03,blank control 1.19±0.02,2.02±0.01) (F =3.683,3.762,P =0.013,0.015).The expression of miRNA-214 was downregulated significantly in U937 cells after treated with oligonucleotide (31.1±0.2) compared with those in control groups (randomized control 25.8±0.1,blank control 25.6±0.2) (P ＜ 0.05).Conclusion Targeted inhibition of miRNA-214 with oligonucleotide can suppress U937 cells growth and induce apoptosis.

Effects of hydrogen inhalation on brain injury after intestinal ischemia/reperfusion in rats / 中华麻醉学杂志

Objective To investigate the effects of hydrogen inhalation on the brain injury after intestinal ischemia/reperfusion (I/R) in rats.Methods Fifty-four healthy male Sprague-Dawley rats aged 6-8 months,weighing 285-350 g,were randomly allocated to one of 3 groups (n =18 each):sham operation group (group S),intestinal I/R group (group I/R) and hydrogen inhalation group (group H2).Intestinal I/R was produced by occlusion of the superior mesenteric artery for 90 min followed by reperfusion.2％ hydrogen was inhaled for 3 h starting from the end of ischemia.The cognitive function was detected at 1,2 and 5 days of reperfusion using Morris water maze test.The animals were sacrificed after the test and brains were isolated for detection of the cerebral edema and morphology in brain tissues.The cerebral water content ((wet weight-dry weight)/ wet weight × 100％) was measured.The pathological changes in the prefrontal cortex was observed under light microscope.The neuronal apoptosis was detected by TUNEL.Results Compared with the S group,the number of normal neurons in the prefrontal cortex was significantly decreased,the latency and swimming distance were both prolonged,the frequency of crossing the original platform was decreased,and the cerebral water content and the number of apoptotic neurons were increased in groups I/R and H2 (P ＜ 0.05).Compared with I/R group,the number of normal neurons in the prefrontal cortex was significantly increased,the latency and swimming distance were both shortened,the frequency of crossing the original platform was increased,the cerebral water content and the nunber of apoptotic neurons were decreased in group H2 (P ＜ 0.05).The pathological changes were obvious in I/R group,however,they were significantly attenuated in H2 group.Conclusion H2 inhalation can reduce the brain damage and improve the cognitive dysfunction after intestinal I/R in rats.

The Clinical Characteristics of Elderly Sleep Apnea Syndrome / 中国医师杂志

Objective To study the clinical characteristics of elderly sleep apnea syndrome (ASA). Methods 329 SAS patients diagnosed by 7-hour polysomnography(PSG) were classified into the aged and the middle aged groups. Results Both the body mass index(BMI) and neck circumference were significantly lower in the aged group than those in the middle aged group(P