Epidemiological survey on a family aggregation COVID-19 in Y County, Chenzhou City, Hunan / 上海预防医学

Objective To investigate epidemic characteristics of a family aggregation COVID-19, and to provide scientific basis for prevention and control of family aggregation epidemic. Methods] Field epidemiological methods were used to investigate the cases and close contacts of a family aggregation COVID-19 in Y County, Chenzhou City, Hunan Province. Descriptive statistical analysis was used on epidemiological data . The 2019-nCoV nucleic acid was detected by real-time fluorescence quantitative RT-PCR. Results It was found that Ms. Deng was infected with COVID-19 and became the infectious source of the family aggregation epidemic , who had lived in Wuhan Hubei Province. Her boyfriend Mr. Cao became a second-generation case of COVID-19..Another two asymptomatic but infected persons were family members living with Ms.Deng . Conclusion COVID-19 easily spreads within families. The awareness of family members' protection, the education of new coronavirus pneumonia prevention and control in key groups should be strengthened to avoid the occurrence and spread of family aggregation epidemic.

Obstetric outcome of vanishing twins syndrome: a systematic review and meta-analysis.

PURPOSE: Due to the high number of multiple embryo transfers into the uterus performed in assisted reproductive technology treatment (ART), the incidences of twin pregnancy and of vanishing twin syndrome (VTS) are correspondingly high. A number of studies have described the obstetric outcomes of the remaining fetus produced after the other twin had vanished compared with a singleton at the start following ART, but the results are mixed and contradictory. We performed a systematic review of the existing studies to explore the actual obstetric outcome of VTS to allow physicians to adequately advise their patients. METHODS: A detailed search strategy was used to conduct electronic literature searches (spanning 1978-2015) on Medline, EMBASE, the Cochrane library and Web of Science. As randomized trials are not feasible in this aspect, we included observational (cohort and case-control) studies which compared the obstetric outcomes of the VTS group and singleton at the start control group after ART. The outcomes were evaluated by two aspects, the duration of pregnancy (gestational age, preterm delivery rate, extremely preterm delivery rate) and the birth weight of the fetus [mean birth weight, low birth weight rate, very low birth weight rate and small for gestational age (SGA)]. RESULTS: 1271 publications were identified by the initial search. 499 studies were excluded following duplication checks. 760 were excluded after reviewing the abstracts. Of the remaining 12 articles, 7 were excluded after a detailed full-text review. Two case-control studies and three cohort studies were included in the final analysis. The pooled mean gestational age difference (95% confidence intervals) was -0.27 (-0.60, 0.06) and failed to demonstrate a difference between the two groups. A similar result was found in the preterm delivery rate, with a pooled risk ratio of 1.33 (0.91, 1.94). The prevalence of extremely preterm delivery rate was higher in the VTS group, with a pooled risk ratio of 3.5 (1.72, 7.12). The mean birth weight was lower in the VTS group, with a mean difference of -0.3 (-0.59, -0.01). No difference was found in low birth weight rate, very low birth weight rate and rate of small for gestational age, with risk ratio of 1.85 (0.88, 3.86), 4.86 (0.91, 25.91) and 1.29 (0.52, 3.18), correspondingly. CONCLUSIONS: There is a slight adverse effect of VTS on the remaining fetus for birth weight and extremely preterm delivery rate, but sensitivity analysis shows these effects to be statistically unstable. It is too early to draw conclusions for adverse obstetric outcomes for VTS patients. It could reduce much of the anxiety of couples who experience early embryonic loss of one of their twins. More research with rigorously designed and standardized methodologies are required that include larger, better clinically defined populations. Studies that show no correlation should be published in the future to avoid any possible impact of publication bias. After that, patients can receive the most accurate information.

Effect of unfractionated heparin on endothelial glycocalyx in a septic shock model.

BACKGROUND: The constituents of vascular endothelial glycocalyx, such as syndecan-1 and heparan sulphate (HS), can be detected in the plasma of patients and animals with septic shock. However, the dynamics of glycocalyx degradation and its association with inflammation remains largely unknown. In this study, we investigated the association between the biomarkers of acute endothelial glycocalyx degradation and inflammatory factors. We also evaluated the effect of unfractionated heparin (UFH) on glycocalyx shedding in a canine septic shock model. METHODS: Twenty adult beagle dogs were randomly allocated to one of the following four groups (n = 5): (1) a sham group; (2) a shock group [3.5 × 10(8) colony-forming unit (cfu) Escherichia coli (E. coli)/kg]; (3) a basic therapy group (sensitive antibiotics and 0.9% saline, 10 ml/kg/h); and (4) a heparin group (40 units/kg/h UFH plus basic therapy). After the onset of septic shock, systemic haemodynamic indices were measured. Endothelial glycocalyx degradation markers (i.e., syndecan-1, HS) and inflammatory factors [i.e., interleukin 6 (IL-6), tumour necrosis factor (TNF)-α], platelet count and activated partial thromboplastin time were measured at various time points. RESULTS: A lethal dose of E. coli induced a progressive septic shock model. We observed increased syndecan-1 and HS levels, which correlated with IL-6 and TNF-α in the septic shock model. The glycocalyx shedding was reduced by UFH, which might be regulated by the inhibition of inflammatory factors. CONCLUSIONS: A therapeutic dose of UFH can protect glycocalyx from shedding by inhibiting inflammation. Additional studies with larger sample sizes are needed to confirm our conclusions.

Analysis of interventional treatments of Budd-Chiari Syndrome and the related complications: a study of 1006 cases.

AIM: The aim of this paper was to investigate the cause of intraoperative and postoperative complications in Budd-Chiari syndrome (BCS) and its prevention. METHODS: BCS Patients (1035) who were treated between 1990 and 2009 were included in the present study. Among these patients, there were 651 cases with inferior vena cava occlusion, 273 cases with hepatic vein obstruction and 111 cases with both the symptoms. Treatment for 28 patients failed due to various causes and 1 case diagnosed of obstruction in the right hepatic vein was not treated due to the compensation from the middle and left hepatic vein. The remaining 1006 cases were resolved by the percutaneous transluminal angioplasty (PTA), of which 746 cases had only PTA and 260 cases had both PTA and stent. RESULTS: There were complications in 66 (6.56%) cases after intervention and 2 patients (0.199%) died. Accidental surgical penetration of the pericardium or cardiac tamponade (0.99%) led to the death of 10 patients, among which 4 cases had cardiac tamponade and one died due to the tamponade. In 2 (0.199%) patients there was stent migration into the right atrium from inferior vena cava. Pleural bleeding was seen in 1 case (0.099%) and abdominal bleeding in 2 cases (0.199%). Two cases (0.199%) had pulmonary obstruction. A single (0.099%) case had chocolate cyst rupture in thrombolytic process. Twenty-seven patients had acute re-stenosis after the surgery, among which 22 (2.95%, 22/746) had the stenosis after only PTA and 5 (1.92%, 5/260) had the stenosis after receiving both PTA and stent. 3 (0.298%) cases had pseudoaneurysm at the puncturing site. Puncture site bleeding and local hematoma was seen in 10 cases (0.99%), whereas 4 cases (0.398%) had leg phlebothrombosis on the same side of the puncture site. CONCLUSION: Interventional treatment is a safe and effective way to treat BCS. Various effective measures should be taken to avoid and lower the incidence of complications.

Analysis of the clinicopathological features of hepatocellular carcinoma in elderly patients.

The peak age of onset of hepatocellular carcinoma (HCC) is continually increasing worldwide. This study aims to evaluate whether there exists any significant difference in the clinicopathological features between younger- and elderly-HCC.1082 Consecutive patients with HCC who underwent liver resection at Liver Cancer Institute, Zhongshan Hospital, Fudan University from 1995 to 1998 were studied. The patients were divided into elderly-HCC (>or=65 years of age) and younger-HCC (< 65 years of age). Important clinicopathological features of the patients and postoperative survival rates were compared between these two groups. Among 1082 patients studied, 108 were elderly-HCC and 974 were younger-HCC. The resection rate of the elderly-HCC was significantly higher than that of the younger-HCC. The 1, 3 and 5-year survival rates of the elderly-HCC were not significantly different from those of the younger-HCC. Compared with the younger-HCC, the elderly-HCC had (1) less HBsAg-positive rate; (2) more frequent anti-HCV positivity ; (3) lower proportion with AFP value >or=400 microg/dl; (4) a relatively small tumor diameter; (5) higher proportion of stage I-II patients; (6) a relatively low metastasis rate. However, there were no statistically significant differences in other clinicopathological features (including gender, symptoms, tumor number, tumor venous invasion, tumor differentiation, capsular formation, type of cirrhosis) between the two groups. There is a certain extent difference in clinicopathological features between elderly and younger-HCC patients, but the postoperative survival rate is comparable between the two groups.

[Study on the effects of DNA damage induced by cigarette smoke in male mice testicular cells using comet assay].

The mainstream whole smoke was collected using atmosphere collector-U shape glass plate absorption tube with poly-hole, and both dimethyl sulfoxide(DMSO) and phosphate buffer solution (PBS) were used as absorbents respectively. Comet assay was used to detect the effects of DNA damage of the two solutions of cigarette smoke in male mice testicular cells. The results showed that both the two solutions of cigarette smoke contained some DNA damage agents that could induce the DNA single strand breakage in male mice testicular cells. Besides, the solution of cigarette smoke absorbed by DMSO had stronger cytotoxicity and genotoxicity than the solution of cigarette smoke absorbed by PBS. The research also suggested that collecting cigarette smoke like this paper and detecting DNA damage effects using comet assay might be an ideal measure in studying male reproducible toxicity.

[Studies on the specificity of target organs and repair dynamics of DNA damage induced by 1,2-dichloroethane].

In order to investigate the genotoxicity of 1,2-dichloroethane (DCE) and to determine its carcinogenic targets, the DNA damage and repair dynamics were detected by using comet assay in the isolated nuclei with tissue-homogenization. Liver, lung, kidney, spleen, bone marrow, testicle, stomach, colon, bladder, and peripheral lymphocytes of mice were isolated at 3 h, 8 h, 24 h after DCE being gavaged. The results showed that: a) liver, lung, kidney, bone marrow, colon, stomach and peripheral lymphocytes were the genotoxic target organs of DCE in mice; b) DNA damage and repair dynamics were obviously different among the test organs, and the organs with DNA damage and slow repaired (lung, stomach and hemocyte) were in accordance with the carcinogenic targets. The results indicate that multiple organ comet assay in vivo is very useful for the evaluation of genotoxicity and prediction of carcinogenic target organ. The comet tail of peripheral lymphocyte is suitable as a biomarker for DNA damage in the target organs of living creatures and population exposed to DCE. It is suggested that in vivo comet assay is also very important to select right marker cells and biomarker in the epidemiological studies on genotoxicity.

[Detection of DNA crosslinks with comet assay].

A simple and rapid method for the detection of DNA cross-links was explored. DNA cross-links was induced by formaldehyde (FA) in TK6 cells. Hydrogen peroxide was used as a standard DNA breakage agent. Two protocols on detecting DNA cross-links with comet assay were tested and compared. The results showed that with increasing FA, the length of DNA migration caused by H2O2 was decreased. When the level of FA was 1000 mumol/L, no any tailed cell could be observed, the migration of DNA was inhibited completely even H2O2 was used. The detection of DNA cross-link could be tested by both protocols. However, when the DNA cross-link agent (FA) was added to the cells before the treatment with DNA breakage agent (H2O2), the result of the scheme was much better than that in the opposite order. The former scheme was much easy to be manipulated, with no influence from DNA repair and had better dose-response relationship in the detection of DNA cross-links. The comet assay is indeed a sensitive, convenient and rapid method for the detection of DNA cross-link.

[Distinguishing apoptotic cells from DNA strand-broken cells by comet assay].

Apoptosis of immature thymocyte of mice induced by dexamethasone and DNA strand-broken cells induced by K2Cr2O7 were tested by comet assay. The results showed that the morphology of apoptotic cells assayed by comet was special. Under the same condition, the time of apoptotic cells running on electrophoresis was shorter than DNA-broken cells. The length of comet tail of DNA strand-broken cells increased in a dose-response relation with the increase of K2Cr2O7, whereas, the apoptotic index increased with the dosage of dexamethasone. While DNA damage was repairing, apoptosis continued to process. The DNA strand-broken cells could be obviously seen while DNA damage was repairing. It was suggested that comet assay could be used to detect DNA strand break sensitively, but also could distinguish different grades of DNA damage, which is helpful for studies on the etiology, progressing and outcome of cancer.

[Detection of apoptotic cells by comet assay].

Comet assay is a method measuring DNA strand beaks on single cell level, which has been developed for about 10 years. Theoretically, apoptotic cells with extensive DNA internucleosomal fragments can be detected by this method. On the basis that apoptosis in immature mice thymocytes could be induced by dexamethasone(DEX), the detection of apoptotic cells by comet assay was studied and compared with agarose gel electrophoresis, morphological observations with Giemsa staining and TUNEL assay. Apoptotic cells showed a comet feature with a very small head, and a large and wide tail. The optimal conditions for electrophoresis in comet assay was 20 volt in 15 minutes. Comet assay is sensitive, valid, rapid and simple and is highly correlated with Giemsa staining and TUNEL assay in detecting apoptotic cells.

In vitro and in vivo transformation in rat tracheal epithelial cells exposed to diesel emission particles and related compounds.

The rat tracheal epithelial (RTE) cell transformation assay was performed to determine the transforming activity of diesel emission particles (DEPs) and two related compounds, 1-nitropyrene (1-NP) and dibenzo(a,i)pyrene (DBP). RTE cells were treated with these agents in vitro and in vivo. Transformed cells from foci induced by these agents were passaged over 20 times to establish immortal cell lines. Results show that (1) DEPs- and 1-NP-induced cell transformation only with the in vivo exposure (30-75 mg/kg bw DEPs and 15-60 mg/kg bw 1-NP); (2) positive dose-related responses to DBP were found with both in vitro (0.05-0.50 microg/ml) and in vivo (7.5-30 mg/kg bw) exposures; (3) the fraction of transformed foci becoming cell lines was in the order of 1-NP(25/48) > DBP(8/28) > DEPs(0/30). These results indicate that (1) DEPs, 1-NP and DBP are capable of transforming rat tracheal epithelial cells, however, the transforming activity of DEPs and -NP may be dependent on metabolic activation, and (2) transformed cells induced by DEPs have a very low probability, if any, of becoming cell lines.

[Effects of low temperature storage on DNA migration assayed by single cell gel electrophoresis].

V79 cells treated with potassium dichromate and control cells were stored at 4 degrees C, -20 degrees C, -80 degrees C and -196 degrees C. Single cell gel electrophoresis (SCGE) was carried out after preserving cells for 0, 4, 24, 48 and 168 hours. The results showed that there was no difference on DNA migration between cells processing immediately after trypsinization and cells preserving for 24 h at different low temperatures. Longer storage (48 h or 168 h) resulted in a significant increase in the length of DNA migration and decrease in cell viability. The results suggested that 4 degrees C is more convenient for less than 24 h storage without influence on DNA migration and -80 degrees C is better for longer storage to minimize the influence on DNA migration.

[Study on the mechanism for fetal asphyxia in intrahepatic cholestasis of pregnancy].

OBJECTIVE: To investigate the cause of fetal asphyxia of mothers with intrahepatic cholestasis of pregnancy (ICP). METHODS: The cord plasma erythropoietin (EPO) concentrations were measured in 37 infants of mothers with ICP and 46 control infants after elective cesarean section. Furthermore, the transfer of oxygen across the placental membranes in ICP group (n = 7) were compared with controls (n = 8) by dual perfusion of the human placental lobule in vitro. RESULTS: The oxygen transfer across the placental membrane in ICP was similar to the controls (P < 0.05). However cord venous EPO was lower in infants delivered by elective cesarean section from women with ICP (13.58 +/- 8.88 IU/L, P < 0.05) than that in control infants (20.43 +/- 14.15 IU/L). CONCLUSION: The transfer of oxygen across the placental membrane in ICP may be normal. The lower cord venous EPO value in ICP may be mainly responsible for the fetal asphyxia.

In vitro studies on the genotoxicity of 2,4-dichloro-6-nitrophenol ammonium (DCNPA) and its major metabolite.

2,4-dichloro-6-nitrophenol ammonium (DCNPA) is used as a herbicide. However, information on the potential health hazards of DCNPA is limited. In a previous study, we found that DCNPA is genotoxic to Bacillus subtilis and yeast. Further studies were performed to determine whether DCNPA and its major metabolite, 2,4-dichloro-6-aminophenol (DCAP), can induce reverse mutations in Salmonella, gene mutations at the HPRT locus, sister chromatid exchanges (SCEs) and micronuclei (MN) in V79 cells. Results show that DCNPA does not produce a positive response for any endpoint at concentrations tested. However, treatment of V79 cultures with DCAP caused a significant increase in SCEs and MN in a concentration-dependent manner. These results indicate that DCAP damages DNA and causes chromosomal aberrations in V79 cells. Therefore, DCNPA could pose potential health hazards to populations exposed to this herbicide.

Induction of chromosomal aberrations by 2,4-dichloro-6-aminophenol in cultured V79 cells.

2,4-Dichloro-6-aminophenol (DCAP) is a major metabolite of the herbicide 2,4-dichloro-6-nitrophenol ammonium (DCNPA). In our previous studies this metabolite, but not the parent compound, was found to induce sister chromatid exchanges (SCEs) and micronucleus (MN) formation in Chinese hamster lung fibroblasts (V79 cells). Further studies were carried out to determine whether DCAP can also induce structural chromosomal aberrations (CAs) in cultured V79 cells. The assay was performed under three different treatment conditions: 1) 3 h treatment followed by 17 h post-treatment incubation. 2) 12 h treatment, and 3) 20 h treatment with multiple sampling times. Results showed that CAs were induced by DCAP in V79 cells. The aberrations were mainly chromatid types (gaps, breaks, and deletions), triradials, quadriradials, and complex rearrangements. However, induction of CAs appears to be dependent on the treatment condition. The 3 h treatment following a 17 h post-treatment incubation gave rise to 24% aberrant cells (excluding gaps) and a total of 44 aberrations per 100 metaphases, while the 12 h treatment only gave a borderline response and the 20 h treatment did not yield a significant increase of CAs at any concentration tested. It seems that a short-term treatment with higher concentrations is a better treatment protocol for genotoxicity studies of certain cytotoxic chemicals such as DCAP. Results of this study further indicate that the herbicide DCNPA is potentially hazardous to the exposed population.

The phase transition in annealed mechanically alloyed Fe - Cu.

Using Mössbauer spectra and x-ray diffraction patterns, annealed mechanically alloyed Fe - Cu has been investigated in this paper. It is found that in [Formula: see text], after it has been milled, fcc-Cu has transformed into bcc-Cu, and some Cu atoms have diffused into the Fe. After the alloy has subsequently been annealed, it is found that bcc-Cu has transformed back into fcc-Cu, while the Cu atoms in the Fe have been separated. In [Formula: see text], after being milled, an fcc-Fe-rich phase has been formed, and after the alloy has subsequently been annealed, this has transformed back to bcc-Fe. The shorter the milling time and the higher the annealing temperature, the faster the transformation. In [Formula: see text], after it has been annealed, the fcc-Fe-rich phase has transformed to bcc-Fe also, and the fcc-Cu-rich phase remains when the annealing temperature increases. All of these results show that the fcc-Fe-rich phase in the milled samples is a metastable phase - it will transform to stable bcc-Fe when it is annealed - while the long-milling-product fcc-Cu-rich phase is a stable phase.

[Genotoxicity of herbicide 83-1 in yeast assay system].

The genotoxicity of Herbicide 83-1 (Dichloronitrophenolamide, DCNPA) was detected by the yeast D61.M and D7 assay with multi-endpoint. We noted that the frequency of cyhR (resistance to cycloheximide) colonies of D61.M treated with DCNPA on cycloheximide medium was much higher than that of the control (P < 0.01) and that there was a dose-response relationship. These showed that the positivity responsed to the mitotic crossing-over endpoint. To the remaining endpoints in the D61.M and D7 assay, however, the negative response was obtained. The results have demonstrated that Herbicide 83-1 is a DNA damage agent.