The effect of overweight or obesity on the negative conversion time of SARS-CoV-2 nucleic acid / 中国热带医学

@#Abstract: Objective　To investigate the relationship between the body mass index (BMI) levels and the negative conversion time of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid in adult coronavirus disease 2019 (COVID-19) patients and the asymptomatic persons. Methods　Asymptomatic infected patients and confirmed COVID-19 patients admitted to Chengdu Public Health Clinic Center from February 2021 to November 2021 were dynamically included. The epidemiological and clinical characteristics of the objects were collected, and the SARS-CoV-2 nucleic acid testing of the objects during their hospitalization was continuously monitored, and the negative nucleic acid conversion time was recorded. The t test or Wilcoxon rank sum test, χ2 test or Fisher's exact probability method examine were used to distribute characteristics of each group of variables and the connection between different variables, respectively. Then the variables showed differences in distribution (P<0.05) between different BMI groups were included in the multivariate Cox proportional risk regression model. Results　A total of 253 subjects ranged from 18 to 63 years old, with M(P25, P75) age of 37.0 (30.0, 47.0) years old, were included in this study. The male to female ratio was 4.16 to 1. The BMI was (23.97±3.33) kg/m2. 50.59% (128/253) of the objects were overweight or obese, and 78.13% (100/128) were overweight. The negative time of SARS-CoV-2 nucleic acid conversion of all subjects ranged from 1 to 71 days, with M(P25, P75) of 7.0 (2.0, 18.0) days (P<0.001). The negative time of SARS-CoV-2 nucleic acid conversion of the normal weight or the thin, and the overweight or obese were 5.00 (2.00, 19.00) and 8.00 (2.00, 17.75) days respectively. The results of multivariate Cox's proportional hazards regression model showed that the BMI levels may not be associated with the negative conversion time of SARS-CoV-2 nucleic acid (HR=1.090, 95%CI: 0.843-1.410, P=0.510). Conclusions　Adult asymptomatic persons and confirmed COVID-19 patients are mainly middle-aged and young males, and overweight or obesity is relatively common. Overweight or obesity cannot be considered as an independent factor influencing the negative conversion time of SARS-CoV-2 nucleic acid.

Detection performance of PCR for Legionella pneumophila in environmental samples: a systematic review and meta-analysis.

BACKGROUND: Legionellosis remains a public health problem. The most common diagnostic method to detect Legionella pneumophila (L. pneumophila) is culture. Polymerase chain reaction (PCR) is a fast and accurate method for this detection in environmental samples. METHODS: Four databases were searched for studies that evaluated the detection efficiency of PCR in L. pneumophila. The quality evaluation was conducted using Review Manager 5.3. We used Meta-DiSc 1.4 software and the Stata 15.0 software to create forest plots, a meta-regression, a bivariate boxplot and a Deeks' funnel plot. RESULTS: A total of 18 four-fold tables from 16 studies were analysed. The overall pooled sensitivity and specificity of PCR was 94% and 72%, respectively. The positive likelihood ratio (RLR) and negative likelihood ratio (NLR) was 2.73 and 0.12, respectively. The result of the diagnostic odds ratio (DOR) was 22.85 and the area under the curve (AUC) was 0.7884. CONCLUSION: Establishing a laboratory diagnostic tool for L. pneumophila detection is important for epidemiological studies. In this work, PCR demonstrated a promising diagnostic accuracy for L. pneumophila.

Black rice-derived anthocyanins inhibit HER-2-positive breast cancer epithelial-mesenchymal transition-mediated metastasis in vitro by suppressing FAK signaling.

This study aimed to investigate the role of focal adhesion kinase (FAK) signaling in the inhibitory effects of black rice anthocyanins (BRACs) on human epidermal growth factor receptor-2 (HER-2)-positive human breast cancer cell metastasis, using the MCF-10A, MCF-7 and MDA-MB-453 cells. BRACs exerted an anti-metastatic effect on the HER-2-positive breast cancer cells. The effects of BRACs on the proliferation of the MDA-MB-453 cells were examined by cell counting kit-8 assay. A wound-healing assay was used to examine the effects of BRACs on the migration of the breast cancer cells. BRACs interrupted migration and invasion. BRACs decreased the migration distance of the HER-2-positive human breast cancer cells, MDA-MB-453, by 37% compared with the cells in the untreated group. They also reduced the number of invading MDA-MB-453 cells by 68%. In addition, BRACs exerted an inhibitory effect on epithelial-mesenchymal transition. Western blot analysis revealed that BRACs decreased the phosphorylation of FAK, cSrc and p130Cas. The FAK inhibitor, Y15, was also used to further evaluate the role of FAK signaling in the anti-metastatic effects of BRACs on MDA-MB-453 cells. The results of western blot analysis revealed that BRACs increased the expression of the epithelial marker, E-cadherin, and decreased the expression of the mesenchymal markers, fibronectin and vimentin, in the MDA-MB­453 cells. In addition, BRACs decreased the interaction between HER-2 and FAK, FAK and cSrc, cSrc and p130Cas, and between FAK and p130Cas. These results suggest that BRACs suppress the metastasis of HER-2-positive breast cancer in vitro, and that the cSrc/FAK/p130Cas pathway plays a vital role in this inhibitory effect.

Evodiamine suppresses proliferation of colon cancer HCT-116 cells in mice / 基础医学与临床

Objective To investigate the effect of evodiamine on proliferation of HCT-116 in balb/c nude mice, and to explore possible mechanism. Methods HCT-116 cells were injected into the right armpit of 4 week old Balb/c nude mice, the feeding had been executed at the time of the diameter of the xenografted tumor reached 0.5 cm,at the dose of 3 mg/kg (Evo), body weight and tumor diameter had been tested every three days, and made the curve of body weight and tumor diameter of the mice. All the mice were sacrificed after 22 days of feed-ing,and harvested the xenografted tumors. The morphological difference of the two groups tumor were identified by HE staining,the expression of HDAC3, NF-κB and p53 protein were detected by IHC and Western blot. Results Compared with the control groups, the volume and weight of the tumors in Evo groups were significantly lighter, and the body weight of the nude mice were heavier,the tumor cells in Evo groups were shrink,deeply staining nu-celus and their abnormal mitoses were fewer,the expression of NF-κB and p53 were increased but HDAC3 was de-creased in xenografted tumors treated with Evo(P<0.05). Conclusions Evo can change the expression of NF-κB and p53 by down-regulating HDAC3,and inhibit the proliferation of HCT-116 cells line in vivo.

Evodiamine suppresses proliferation of colon cancer HCT-116 cells in mice / 基础医学与临床

Objective To investigate the effect of evodiamine on proliferation of HCT-116 in balb/c nude mice, and to explore possible mechanism. Methods HCT-116 cells were injected into the right armpit of 4 week old Balb/c nude mice, the feeding had been executed at the time of the diameter of the xenografted tumor reached 0.5 cm,at the dose of 3 mg/kg (Evo), body weight and tumor diameter had been tested every three days, and made the curve of body weight and tumor diameter of the mice. All the mice were sacrificed after 22 days of feed-ing,and harvested the xenografted tumors. The morphological difference of the two groups tumor were identified by HE staining,the expression of HDAC3, NF-κB and p53 protein were detected by IHC and Western blot. Results Compared with the control groups, the volume and weight of the tumors in Evo groups were significantly lighter, and the body weight of the nude mice were heavier,the tumor cells in Evo groups were shrink,deeply staining nu-celus and their abnormal mitoses were fewer,the expression of NF-κB and p53 were increased but HDAC3 was de-creased in xenografted tumors treated with Evo(P<0.05). Conclusions Evo can change the expression of NF-κB and p53 by down-regulating HDAC3,and inhibit the proliferation of HCT-116 cells line in vivo.

Anti-metastasis activity of black rice anthocyanins against breast cancer: analyses using an ErbB2 positive breast cancer cell line and tumoral xenograft model.

BACKGROUND: Increasing evidence from animal, epidemiological and clinical investigations suggest that dietary anthocyanins have potential to prevent chronic diseases, including cancers. It is also noteworthy that human epidermal growth factor receptor 2 (ErbB2) protein overexpression or ErbB2 gene amplification has been included as an indicator for metastasis and higher risk of recurrence for breast cancer. MATERIALS AND METHODS: The present experiments investigated the anti-metastasis effects of black rice anthocyanins (BRACs) on ErbB2 positive breast cancer cells in vivo and in vitro. RESULTS: Oral administration of BRACs (150 mg/kg/day) reduced transplanted tumor growth, inhibited pulmonary metastasis, and decreased lung tumor nodules in BALB/c nude mice bearing ErbB2 positive breast cancer cell MDA-MB-453 xenografts. The capacity for migration, adhesion, motility and invasion was also inhibited by BRACs in MDA-MB-453 cells in a concentration dependent manner, accompanied by decreased activity of a transfer promoting factor, urokinase-type plasminogen activator (u-PA). CONCLUSIONS: Together, our results indicated that BRACs possess anti-metastasis potential against ErbB2 positive human breast cancer cells in vivo and in vitro through inhibition of metastasis promoting molecules.

Direction and extent of organelle DNA introgression between two spruce species in the Qinghai-Tibetan Plateau.

A recent model has shown that, during range expansion of one species in a territory already occupied by a related species, introgression should take place preferentially from the resident species towards the invading species and genome components experiencing low rates of gene flow should introgress more readily than those experiencing high rates of gene flow. Here, we use molecular markers from two organelle genomes with contrasted rates of gene flow to test these predictions by examining genetic exchanges between two morphologically distinct spruce Picea species growing in the Qinghai-Tibetan Plateau. The haplotypes from both mitochondrial (mt) DNA and chloroplast (cp) DNA cluster into two distinct lineages that differentiate allopatric populations of the two species. By contrast, in sympatry, the species share the same haplotypes, suggesting interspecific genetic exchanges. As predicted by the neutral model, all sympatric populations of the expanding species had received their maternally inherited mtDNA from the resident species, whereas for paternally inherited cpDNA introgression is more limited and not strictly unidirectional. Our results underscore cryptic introgressions of organelle DNAs in plants and the importance of considering rates of gene flow and range shifts to predict direction and extent of interspecific genetic exchanges.

Mycotoxin Ochratoxin A-induced cell death and changes in oxidative metabolism of Arabidopsis thaliana.

We evaluated the phytotoxicity of mycotoxin ochratoxin A (OTA) from Aspergillus and Penicillium strains on Arabidopsis thaliana. The results demonstrate that the growth of Arabidopsis thaliana on media containing OTA was inhibited significantly. Moreover, OTA induced necrotic lesions in detached leaves, which are reminiscent of hypersensitive response lesions that are activated during plant-pathogen interactions and other abiotic stress factors. From our study, we can see that OTA exposure stimulated a biphasic oxidative burst in the leaves, resulting in the generation of hydrogen peroxide (H2O2) and superoxide anion radicals (O2(.-)) and in the concomitant down-regulation of antioxidant enzyme defense responses and up-regulation of lipid peroxidation. These results suggested that OTA damage might result from reactive oxygen species pathways. Our experiments provide a useful model plant system for research on OTA-induced plant cell death.

[Effect of soy isoflavone on gene expression of leptin and insulin sensibility in insulin-resistant rats].

OBJECTIVE: To explore the effects of soy isoflavone (SIF) on gene expression of leptin and insulin sensibility in insulin-resistant (IR) rats induced by high-fat, and to reveal the mechanisms of SIF in ameliorating insulin sensibility. METHODS: IR rats were randomly divided into four groups based on their insulin-resistant indexes (IRI): one model control group and three SIF groups that were gavaged with water solutions with SIF at doses of 0 mg/kg, 50 mg/kg, 150 mg/kg, and 450 mg/kg, respectively. After one month, fasting glucose, fasting insulin, leptin in serum, and leptin mRNA in the perirenal adipocyte were detected by enzymic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time quantitative RT-PCR, respectively. RESULTS: The model control group was used to compare against the other groups: (1) Insulin and IRI were lower in the 150 mg/kg and 450 mg/kg groups; (2) In the 450 mg/kg group, body weight and leptin mRNA expression were lower, serum leptin content was higher. CONCLUSION: These results indicate that soy isoflavone might decrease body weight of rats and leptin mRNA, increase serum leptin level, and ameliorate leptin and insulin sensitivities.

[Establishment of immunomagnetic capture-fluorescent PCR detection method for Campylobacter jejuni].

In order to develop a rapid method which can check Campylobacter jejuni in animal and poultry foods nicely, an immunomagnetic capture-fluorescent PCR (IMC-FPCR) method was established in this paper. The reported method involves isolation of the target pathogen by immunocapture prior to the fluorescent PCR step, therefore the immunomagnetic-beads for Campylobacter were developed, and two groups of primer/probe, which targeted for the species special sequence of flaA gene and hipO gene for Campylobacter jejuni were designed. The immunomagnetic capture-fluorescent PCR assay amplification of the hipO gene and flaA gene for detection of Campylobacter jejuni was firstly reported in this paper. Result indicated that IMC-FPCR method permits direct detection of the pathogen without an enrichment step and can be performed in approximately 24 h. The assay results are positive for all of the isolates of Campylobacter jejuni (3 isolates, including type strain ATCC 33560 and ATCC8341) with a detection limit of approximately 10 cfu/mL, are negative for Campylobacter coli and several other bacteria. IMC-FPCR assay provide not only a rapid, sensitive method for quantitative detection of Campylobacter jejuni, but also an important method for detecting of Campylobacter jejuni of viable but non-culturerable (VNC) state.

Effects of intravenous Injections Paederiae and Stauntonia on spontaneous pain, hyperalgesia and inflammation induced by cutaneous chemical tissue injury in the rat.

To study whether commercial traditional Chinese medicinal preparations Injection Paederiae (IP) or Injection Stauntonia (IS) has anti-nociceptive and/or anti-inflammatory effects, we used two persistent pain models (bee venom and formalin test) to evaluate the systemic effects of IP or IS on the chemical tissue injury-induced persistent spontaneous pain-related responses (PSPR), primary thermal/mechanical hyperalgesia and inflammation in conscious rats. Injection of bee venom (BV, 0.1 mg, 50 microl) into the plantar surface of one hind paw resulted in not only a 1-h monophasic PSPR such as flinching reflex in the injected paw and a subsequent period of 3-4 days primary heat and mechanical hyperalgesia, but also a marked sign of inflammation, including redness and swelling of the plantar surface in the injected paw. Intraplantar injection of formalin produced two phases of PSPR as reported previously. Systemic pre-treatment with three doses of IP (0.32, 1.6 and 9.0 ml/kg, 500%) or IS (0.32, 1.6 and 9.0 ml/kg, 250%) produced a dose-dependent suppression of the BV- or formalin-induced flinching reflex of 1 h time course as compared with the saline control group. Post-treatment with IP or IS 5 min after BV injection also produced a significant suppression of the flinching reflex in both BV test and formalin test respectively, as compared with the control group. However, neither pre- nor post-treatment with IP or IS produced any significantly suppressive effect on the BV-induced primary heat and mechanical hyperalgesia and inflammation. The analgesia produced by IP or IS was not mediated by the endogenous opioid receptors since naloxone, a non-selective opioid receptor antagonist, had no reversal effect on the IP and IS-produced analgesia in the BV-induced PSPR. Our present results suggest that IP or IS might prevent and relieve clinical persistent spontaneous pain, but without any anti-nociceptive and anti-inflammatory effects on the primary heat hyperalgesia, mechanical hyperalgesia, as well as inflammatory responses. The BV test might be a useful model of pain to evaluate and screen anti-nociceptive and anti-inflammatory effects of certain compounds of the Chinese medicinal herbs on the pathological origins of pain.