Pathogenesis of COVID-19 and the quality control of nucleic acid detection.

The new coronavirus pneumonia (COVID-19) epidemic spread rapidly throughout the world. Considering the strong infectivity and clustering of COVID-19, early detection of infectious cases is of great significance to control the epidemic. Nucleic acid testing (NAT) plays an important role in rapid laboratory diagnosis, treatment assessment, epidemic prevention and control of COVID-19. However, since COVID-19 is caused by a new emerging virus and NAT for COVID-19 has not been clinically applied before, false negative results inconsistent with clinical diagnosis have appeared in clinical practice. Therefore, it is urgent to improve the sensitivity of NAT for COVID-19. This study aimed to summarize the current situation and prospect of NAT based on the latest findings on COVID-19 infection. Also, the quality control of sample collection was discussed. Hopefully, this study could help to improve the effectiveness of NAT for COVID-19.

Effect and mechanisms of reproductive tract infection on oxidative stress parameters, sperm DNA fragmentation, and semen quality in infertile males.

Recent years have seen a rising incidence of male infertility, mostly caused by the decline of sperm quality. The ratio of infertile males to infertile females has escalated from 3:7 in 2013 to current 5:5, which turns male infertility into the research focus of reproductive medicine. This study aimed to clarify the effect of reproductive tract infection by ureaplasma urealyticum (UU) and chlamydia trachomatis (CT) on the DNA integrity and routine semen parameters of infertile males. A retrospective study was performed. A total of 259 infertile males who were treated at the Andrological Laboratory Examination and Reproductive Medicine Center in our hospital were analyzed. qRT-PCR was used to examine the infection status of CT and UU. According to the eligibility criteria, we evaluated the semen parameters and biochemical data of 253 men. Based on the results of PCR, the subjects were divided into four groups: Group I (CT positive, 63 cases), Group II (UU positive, 60 cases), Group III (CT positive and UU positive, 62 cases), and Group IV (no infection, 68 cases). DNA fragmentation index (DFI), sperm count, vitality and morphology, elastase level, seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) were assessed. Compared to Group IV, three groups (Group I, Group II and Group III) showed difference in semen volume, proportion of sperm with normal morphology, sperm motility, progressive motility, and vitality (P < 0.05). Compared to Group IV, Group II and Group III showed difference in DFI (P < 0.05). Compared to Group IV, Group II and Group III showed difference in elastase level (P < 0.05). VCL, VSL, VAP, WOB, ROS, TM, HDS showed differences between groups of abnormal/normal WBC (*P < 0.01).UU infection significantly increased the level of seminal leukocytes only in Group II, but not in the other three groups, indicating that UU is a factor to increase the level of seminal leukocytes. Compared with the normal leukocyte group, there were significant differences in total motility, forward motility and normal sperm ratio between the two groups. The proportion of sperm with abnormal morphology (mostly in the head) showed obvious difference between groups of high and normal seminal leukocytic levels. At the same time, in this study, SCGE and SCD verified that leukocytes could damage sperm DNA by increasing ROS, which ultimately affects male fertility.

Detection methods and dynamic characteristics of specific antibodies in patients with COVID-19: A review of the early literature.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic. Early and accurate diagnosis and quarantine remain the most effective mitigation strategy. Although reverse transcriptase polymerase chain reaction (RT-qPCR) is the gold standard for COVID-19 diagnosis, recent studies suggest that nucleic acids were undetectable in a significant number of cases with clinical features of COVID-19.Serological assays for SARS-CoV-2 play a role in diagnosis of COVID-19, in understanding viral epidemiology and screening convalescent sera for therapeutic and prophylactic purposes, to better understand the immune response to the virus, and to assess the degree and duration of the response of specific antibodies. In this article, we retrieved PubMed, Embase, China National Knowledge Infrastructure (CNKI) and WEB OF SCI databases for articles and reviews published before December 1, 2022. Using "IgM, IgG,IgA, neutralizing antibody, specific antibody,COVID-19, dynamic characteristics" as keywords, and comprehensively reviewed on their basis.According to the authors' criteria, only articles deemed relevant were included, covering original articles, case series, experimental studies, reviews, and case reports. Articles on performance evaluation, opinion pieces, and technical issues were excluded. From the onset of COVID-19 symptoms, the median time of seroconversion was 11 days for immunoglobulin A (IgA), the median time of peak antibody titer was 23 (16-30 days) for IgA.Immunoglobulin M (IgM) is detected prior to immunoglobulin G (IgG), peaking 2-5 weeks post symptom onset and detectable for a minimum of 8 weeks in the immunocompetent.Neutralizing antibodies were earliest detectable within 6-7 days following disease onset, with levels increasing until days 14-22 before levelling and then decreasing, but titres were lower in clinically mild disease. Different clinical types of patients showed different antibody responses to SARS-CoV-2, with severe COVID-19 patients > non-severe COVID-19 patients > asymptomatic infected persons, but no difference in the early stage of the disease. Usually, IgM and IgA antibodies are detectable earlier than IgG antibodies.IgA antibodys plays an important role in local mucosal immunity.Detection of IgM antibodies tends to indicate recent exposure to SARS-CoV-2, whereas the detection of COVID-19 IgG antibodies indicates virus exposure some time ago. The detection of potent neutralizing antibodies in convalescent plasma is important in the context of development of therapeutics and vaccines.With the emergence of immune escape variants of SARS-CoV-2, humoral immunity is being challenged, and a detailed understanding of Specific antibodies is critical to guide vaccine design strategies and antibody-mediated therapies.

Blood lead levels during pregnancy and its influencing factors in Nanjing, China.

OBJECTIVE: To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery, and analyze the influencing factors of BLLs in healthy pregnant women. METHODS: Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital. Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group, and 120 healthy non-pregnant women as the control group. BLLs during pregnancy were determined by flame atomic absorption spectroscopy. RESULTS: BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3, 55.4±20.1, 55.9±19.7, and 67.6±17.4 µg/L, respectively, and the mean BLL in control group was 67.5±21.3 µg/L. BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043, 0.021, and 0.028). Furthermore, occupations, nutrients supplementation, and time of house/apartment painted were associated with BLLs in pregnant women. Lead-related occupations, cosmetics use, and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women, while calcium, iron, zinc, and milk supplements are protective factors. CONCLUSION: Supplementing calcium, iron, zinc, and milk, or avoiding contact with risk factors may help people, especially pregnant women, to reduce lead exposure.

Neurotoxicity and biomarkers of lead exposure: a review.

Appropriate selection and measurement of lead biomarkers of exposure are critically important for health care management purposes, public health decision making, and primary prevention synthesis. Lead is one of the neurotoxicants that seems to be involved in the etiology of psychologies. Biomarkers are generally classified into three groups: biomarkers of exposure, effect, and susceptibility.The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer's disease, Parkinsons disease, and schizophrenia. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children and adults.

Breast milk lead and cadmium levels in suburban areas of Nanjing, China.

OBJECTIVE: To evaluate levels of lead (Pb) and cadmium (Cd) in the breast milk in the second postpartum month, to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters, and to explore whether these levels affect the infants' physical status or the mothers' psychological status (postpartum depression). METHODS: A cross-sectional study was conducted between November 2009 and December 2010. Altogether 170 healthy mothers were enrolled from Nanjing Maternity and Child Health Care Hospital. The inclusion criteria were: voluntary to participate in this study, healthy, with no chronic disease, breastfeeding in the second postpartum month, living in a suburban but not non-industrial area of Nanjing, and not occupationally exposed to toxic metals. All the mothers completed a questionnaire and were evaluated based on the Edinburgh Postpartum Depression Scale (EPDS) to identify the risk of postpartum depression. Pb and Cd levels in breast milk were determined by inductively coupled plasma mass spectroscopy. The infants of these mothers were examined for their z scores of weight for age, length for age, head circumference for age, and body mass index for age. RESULTS: The median breast milk levels of Pb and Cd were 40.6 µg/L and 0.67 µg/L, respectively. In 164 (96.5%) of the 170 samples, Pb levels were higher than the limit reported by the World Health Organization (> 5 µg/L). Breast milk Cd level was > 1 µg/L in 54 (31.8%) mothers. The mothers with a history of anemia had a higher breast milk Pb level than those without a history of anemia (41.1 µg/L vs. 37.9 µg/L, P = 0.050). The median breast milk Cd level in those who were active and passive smokers during pregnancy was significantly higher than that in non-smokers (0.88 µg/L vs. 0.00 µg/L, P = 0.025). The breast milk Cd level in the mothers not taking iron and vitamin supplements for 2 months postpartum was higher than in those taking the supplements (iron supplement: 0.74 µg/L vs. 0.00 µg/L, P = 0.025; vitamin supplement: 0.78 µg/L vs. 0.00 µg/L, P = 0.005). Breast milk Cd level at the second postpartum month was negatively correlated with the z scores of head circumference (r = - 0.248, P = 0.042) and weight for age at birth (r =- 0.241, P = 0.024) in girls. No correlation was found between the breast milk Pb/Cd levels and the EPDS scores. CONCLUSION: Considering the high levels of Pb and Cd in breast milk in this study, breast milk monitoring programs are necessary.

Research progress on Th22 cells and related cytokines in tumors: current status and future perspectives.

Th22 cells are a newly identified subpopulation of CD4+ T lymphocytes distinct from Th1, Th2, and Th17 cells, which secretes mainly interleukin-22 (IL-22), in addition to a variety of other cytokines. The function of Th22 cells in tumors is mainly realized through IL-22, which can activate JAK/STAT and MAPK cell signaling pathways, thereby regulating the anti-tumor immune response of the body. The main function of Th22 cells is to participate in mucosal defense, tissue repair, and wound healing. However, controversial data have shown that overexpression of IL-22 can lead to pathological changes under inflammatory conditions and tumor progression. In this review, we searched the PubMed and Web of Science databases for articles and reviews published before May 6, 2022, using the keywords "Th22 cells, T helper 22 cells, cancer, tumor", and conducted a comprehensive review of the relevant literature. In addition, this article offers an overview of the relevant findings on the function of Th22 cells in tumors published in recent years, along with a more comprehensive analysis of the functions and mechanisms of Th22 cells in tumors. This article will hopefully inspire new future directions in the research on cancer therapy.

Correlation analysis of sperm DNA fragmentation index with semen parameters and the effect of sperm DFI on outcomes of ART.

Routine semen analysis provides limited information about a man's male reproductive potential and can not always fully explain male infertility. Many male infertilities are caused by sperm DNA defects that routine semen quality analyses fail to detect. In this study, we analyzed the association of sperm DNA fragmentation index (DFI) with the semen routine, sperm morphology, in vitro fertilization embryo transfer (IVF-ET)/intracytoplasmic sperm injection (ICSI). Further, we explored the predictive value of sperm DFI in evaluating male fertility and the outcome of IVF-ET/ICSI. Data on sperm DFI, sperm routine, and sperm morphology were collected from 1462 males with infertility. According to DFI levels, there were 468 cases in group I (DFI ≤ 15%), 518 cases in group II (15% < DFI < 30%), and 476 cases in group III (DFI ≥ 30%). The correlations of sperm DFI with semen routine and malformation rate were analyzed. Seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) were assessed. Sperm DFI, semen routine, and sperm morphology were detected in male patients of 101 pairs of IVF-ET/ICSI infertile couples and subdivided into IVF-I group (DFI ≤ 15%), IVF-II group (15% < DFI < 30%), IVF-III group (DFI ≥ 30%), ICSI-I group (DFI ≤ 15%), ICSI-II group (15% < DFI < 30%) and ICSI-III group (DFI ≥ 30%) according to DFI value. The effect of sperm DFI on the outcome of IVF-ET/ICSI was analyzed. There were significant differences in sperm survival rate, sperm concentration, and PR% between groupIII and group II (P < 0.01). There were significant differences in sperm survival rate, sperm concentration and PR% between group III and group I (P < 0.01). There was no significant difference in semen volume, age, abstinence days, or percentage of normal sperm between the three groups (P > 0.05). DFI was positively correlated with MDA content ( P < 0.01) and negatively correlated with TAC (P < 0.01). Sperm DFI was negatively correlated with sperm survival rate, sperm concentration, and PR% (P < 0.01). There was no correlation with age, abstinence days, semen volume, or percentage of normal-form sperm (r = 0.16, 0.05, 0.04, -0.18, p > 0.05). Compared with IVF-I group, the sperm concentration and PR were decreased in IVF-III group. The sperm malformation rate was higher in IVF-III group than that in IVF-II group. Comparatively, the PR was decreased in ICSI-III group. The sperm malformation rate was higher in ICSI-III group than that of the ICSI-I group (P < 0.05). There were no statistically significant differences in fertilization rate, cleavage rate, embryo rate, and clinical pregnancy rate between IVF group or ICSI group, and between all subgroups (P > 0.05). Sperm DFI is negatively associated with sperm survival rate, sperm concentration, and PR%. Antioxidants can decrease the rate of DNA fragmentation. Sperm DFI has proven to be very valuable in the male fertility evaluation, but its significance as a predictor of pregnancy outcomes following assisted reproductive technology. (ART) requires further investigation.

Clinical significance of regulatory T cells and T lymphocyte subsets in peripheral blood in neoadjuvant chemotherapy for breast cancer.

The impact of the immune response on the therapeutical efficacy of neoadjuvant chemotherapy for breast cancer remains largely unknown. To characterize the role of regulatory T cells (CD4+CD25+CD127lowTreg), T lymphocyte subsets (CD3+, CD4+, CD4+/CD8+) and NK cells in neoadjuvant chemotherapy, we investigated the correlation patterns of these immune cell subsets with the progression of breast cancer. A total of 120 breast cancer patients receiving neoadjuvant chemotherapy in Nanjing Maternal and Child Health Hospital from May 2019 to November 2021 were retrospectively collected as the breast cancer group, and 46 healthy women were selected as the control group. The number of regulatory T cells, T lymphocyte subsets and NK cells in the peripheral blood were analyzed by flow cytometry. Compared with the control group, CD3+, CD4+, CD4+/CD8+ ratio and NK cells were significantly decreased in patients with breast cancer (P < 0.05), while the levels of Treg and CD8+ cells were significantly increased (P < 0.05). In addition, the status of the immune response among breast cancer patients at different clinical stages was obviously different. In higher tumor stages, the level of CD3+, CD4+, CD4+/CD8+ ratio and NK cell were reduced, while the level of Treg and CD8+ T cells gradually increased. Furthermore, we found a lower percentage of CD3+, CD4+, CD4+/CD8+ and NK cells in association with lymph node metastasis, accompanied by a higher number of CD8+ T cells. Interestingly, after treatment with neoadjuvant chemotherapy, the levels of Tregs, CD3+, CD4+ and CD4+/CD8+ ratio of patients were all upregulated compared with the levels before treatment, indicating the recovery of cytotoxic lymphocytes and a consolidation of the immunosuppressive microenvironment at the same time (P < 0.05). Immune dysfunction is commonly observed in breast cancer patients, which is closely associated with tumor progression and lymph node metastasis. Neoadjuvant chemotherapy was found to highly influence the number of T lymphocytes and improve the immune function of T lymphocyte subsets in breast cancer patients. At the same time, as immunosuppressive cells, the proportion of Tregs (CD4+CD25+CD127lowTreg) also increased after treatment with neoadjuvant chemotherapy. Our results provide guidance for the development of new combination strategies during neoadjuvant chemotherapy to reverse the immunosuppressive microenvironment and achieve better clinical outcomes.

Ferroptosis, a new form of cell death: mechanisms, biology and role in gynecological malignant tumor.

Ferroptosis, a term coined by Dixon et al. in 2012, refers to an iron-dependent form of regulated cell death driven by an overload of lipid peroxides on cellular membranes. It is morphologically and mechanistically distinct from apoptosis and other types of regulated cell death. Many studies have confirmed that ferroptosis is involved in the occurrence and development of many diseases, such as neurodegenerative diseases, chronic cardiovascular diseases, respiratory diseases and even tumors. While in the systemic diseases of obstetrics and gynecology, the related researches are still limited. In this article, we retrieved PubMed and WEB OF SCI databases for articles and reviews published before May 6, 2022, using "ferroptosis, ferroptosis regulator, gynecological tumors" as keywords, and comprehensively reviewed on their basis. Here, we systematically summarize the studies on the mechanism and characteristics of ferroptosis, investigate the role of ferroptosis in clinical systemic diseases of obstetrics and gynecology, evaluate the research status, unsolved problems and further research directions of ferroptosis, so as to let people learn more about ferroptosis and establish a research foundation for the exploration of the treatment strategies for ferroptosis-mediated diseases.

Predicting late-onset preeclampsia by detecting ELABELA content using an immunochromatographic colloidal gold test strip: Blood ELABELA content predicts the risk of pre-eclampsia.

Preeclampsia is a pregnancy disorder that seriously affects the outcome of mothers and infants and lacks effective prediction and diagnosis methods. ELABELA is the second endogenous ligand of the apelin receptor (APJ) and is associated with the pathogenesis of preeclampsia. In a previous study, the authors found that the downregulation of ELABELA expression is closely related to late-onset preeclampsia, which may be a marker for the clinical diagnosis of late-onset preeclampsia. In this study, the authors again collected 120 maternal blood samples, including 60 pregnant women with a medical diagnosis of late-onset preeclampsia. ELISA results showed that the serum ELABELA concentration in late-onset preeclampsia pregnant women (12.57 ± 7.77 ng/mL) was significantly lower than that in normal pregnant women (36.99 ± 23.58 ng/mL), which was consistent with previously reported results. Therefore, the authors used an ELABELA monoclonal antibody to label four colloidal gold nanoparticles with different diameters (15, 30, 55, and 150 nm) and developed a transverse-flow immunochromatographic band for the rapid and accurate detection of serum ELABELA levels. The strip test shows that colloidal gold with a diameter of 30 nm can be used as a good ELABELA detection marker and had more than 90% positive detection effect. Therefore, the authors hope that the colloidal gold strip with ELABELA as the diagnostic index developed by us will be popularized and applied in clinical diagnosis.

The globular heads of the C1q receptor regulate apoptosis in human cervical squamous carcinoma cells via a p53-dependent pathway.

BACKGROUND: The globular heads of the human C1q receptor (gC1qR) localize predominantly to the mitochondrial matrix. gC1qR mediates many biological responses, including growth perturbation, morphological abnormalities and the initiation of apoptosis. The purpose of this study was to investigate the relationship between mitochondrial dysfunction, p53 status and gC1qR expression and the regulation of apoptosis in human cervical squamous carcinoma cells (C33a and SiHa). METHODS: Here, gC1qR expression was examined in human cervical tissues using real-time PCR and Western blot analysis. Apoptotic death of C33a and SiHa cells was assessed by flow cytometric analysis that detected the subG1 population. Mitochondrial function was assessed via ROS generation, the content of cytosolic Ca2+, and the change in mitochondrial membrane potential (Δψm). The viability and migration of C33a and SiHa cells were detected via the water-soluble tetrazolium salt (WST-1) assay and the transwell assay, respectively. RESULTS: gC1qR expression was decreased in cervical squamous cell carcinoma tissues compared with normal tissues. C33a and SiHa cells transfected with a vector encoding gC1qR displayed mitochondrial dysfunction and apoptosis, which was abrogated by the addition of a mutant form of p53 or p53 small interference RNA (siRNA). Furthermore, upon overexpression of gC1qR, cell viability and migration were significantly enhanced, and the apoptosis of C33a and SiHa cells were decreased when cells were treated with mutant p53 or p53 siRNA. CONCLUSIONS: These data support a mechanism whereby gC1qR induces apoptosis through the mitochondrial and p53-dependent pathways in cervical squamous cell carcinoma.

Advances in immunotherapy and molecular targeted therapy of gestational trophoblastic tumor: current practice and future perspectives.

Gestational trophoblastic neoplasia (GTN) is a rare pregnancy-related gynecological malignancy caused by abnormal proliferation of placental trophoblastic cells. It can invade the uterine muscle layer and metastasize early, more common in women of childbearing age. GTN is invasive and can destroy surrounding tissues and blood vessels, causing massive bleeding in uterus and metastatic sites (such as lung, liver, brain, etc.) through blood transfer. Chemotherapy is the main treatment for GTN, and the disease is extremely sensitive to chemotherapy and can be cured by chemotherapy. However, in clinical practice, a large number of patients have failed chemotherapy or even multiple treatments due to drug resistance, recurrence or metastasis of special sites. Therefore, how to individually select the initial chemotherapy regimen and reduce the occurrence of drug resistance is the key to the treatment of high-risk GTN. With the remarkable efficacy of immunotherapy in endometrial cancer, cervical cancer and other diseases, the research on GTN has been further deepened. Therefore, this review discusses the mechanism, methods and efficacy of GTN immunotherapy and molecular targeted therapy, in order to provide new ideas for the diagnosis and treatment of GTN.

Laboratory detection of SARS-CoV-2: A review of the current literature and future perspectives.

Nowadays, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), whose infectivity is awfully strong, has been a major global threat to the public health. Since lung is the major target of SARS-CoV-2, the infection can lead to respiratory distress syndrome (RDS), multiple organ failure (MOF), and even death. The studies on viral structure and infection mechanism have found that angiotensin-converting enzyme 2 (ACE2), a pivotal enzyme affecting the organ-targeting in the RAS system, is the receptor of the SARS-CoV-2 virus. Currently, the detection of SARSCoV-2 is mainly achieved using open plate real-time reverse-transcription polymerase chain reaction (RT-PCR). While open plate method has some limitations, such as a high false-negative rate, cumbersome manual operation, aerosol pollution and leakage risks. Therefore, a convenient method to rapidly detect SARS-CoV-2 virus is urgently and extremely required for timely epidemic control with the limited resources. In this review, the current real-time methods and principles for novel coronavirus detection are summarized, with the aim to provide a reference for real-time screening of coronavirus in areas with insufficient detection capacity and inadequate medical resources. The development and establishment of a rapid, simple, sensitive and specific system to detect SARS-CoV-2 is of vital importance for distinct diagnosis and effective treatment of the virus, especially in the flu season.

Immunotherapy and immunobiomarker in breast cancer: current practice and future perspectives.

Among the new cancer cases and resulting deaths among women worldwide, breast cancer is the most significant threat to women's health. In recent years, immunotherapy was initially used to treat patients with metastatic breast cancer, where it demonstrated its unique value by providing a novel way to improve therapeutic effects and prolong survival time. With the development of clinical trials related to immunotherapy for breast cancer, tumour vaccines, such as DNA vaccines, have been observed to improve the disease-free survival (DFS) and overall survival (OS) of patients. Monoclonal antibodies have also shown good efficacy, and adoptive cell therapies, such as CAR-T, exhibit strong tumour killing ability and good safety, and thus, these therapies may comprise a new strategy for the treatment of breast cancer. These breakthrough successes have promoted the achievement of "individualized" breast cancer treatment. Moreover, a recent study showed that patients with various cancer types with a higher tumour mutational burden (TMB) are more likely to benefit from immunotherapy. As research progresses, TMB may also demonstrate a certain clinical significance in the treatment of breast cancer. This paper reviews the latest research progress on breast cancer immunotherapy and the predictive value and application status of TMB in immunotherapy regimens for breast cancer patients to provide a reference for further in-depth studies of breast cancer immunotherapy.

Research progress in breast cancer stem cells: characterization and future perspectives.

More and more studies have proved that there are a small number of cells with self-renewal and differentiation ability in breast tumors, namely breast cancer stem cells. Such cells play a key role in the initiation, development and migration of breast tumors. The properties of breast tumor stem cells are regulated by a range of intracellular and extracellular factors, including important signaling pathways, transcription factors, non-coding RNAs, and cytokines such as Hedgehog, Wnt, Notch, microRNA93, microRNA100, and IL-6. Tumor microenvironment (such as mesenchymal stem cells, macrophages and cytokines) plays an important role in the regulation of breast tumor stem cells. Using the keywords including "breast cancer stem cells", "signal pathway", "chemotherapy tolerance", and "non-coding RNA", "triple negative breast cancer", "inhibitors", this study retrieved the original articles and reviews published before October 3, 2021, from PubMed and WEB OF SCI database and this study performed a comprehensive review of them. After treatment, there is a correlation between the metastasis-prone nature and recurrence with breast cancer stem cells. The signaling pathway of breast cancer stem cells plays a significant role in activating the function of breast cancer cells, regulating the differentiation of breast cancer cells and controlling the division of breast cancer cells. This imbalance leads to the uncontrolled growth and development of breast cancer cells. Targeted therapy that blocks the corresponding pathway may become a new perspective for breast cancer treatment. In addition, corresponding therapeutic strategies can be used according to the expression characteristics of different molecular types of breast cancer stem cells. For ER-positive breast cancer, simultaneous endocrine therapy and targeted therapy of tumor stem cells may improve the efficacy of endocrine therapy. Trastuzumab therapy significantly reduces the risk of recurrence of HER2-positive breast cancer. For drug-resistant patients, combination therapy is required due to the different phenotypes of epithelial-mesenchymal transforming tumor stem cells. This study briefly reviews the research progress of breast cancer stem cell-related signaling pathways and their inhibitors, in order to provide a reference for breast cancer patients to obtain more effective clinical treatment.

Long non­coding RNA TTN­AS1 regulates the proliferation, invasion and migration of triple­negative breast cancer by targeting miR­211­5p.

Increasing evidence has demonstrated that long non­coding RNAs (lncRNAs) serve important roles in numerous malignancies, including triple­negative breast cancer (TNBC). The lncRNA titin­antisense RNA1 (TTN­AS1) has previously been reported to promote tumorigenesis in various types of cancer. The present study aimed to investigate the potential role of TTN­AS1 in breast cancer and the associated underlying mechanisms. Following prediction by Starbase and confirmation by dual­luciferase reporter assay, TINCR was demonstrated to be a target gene for microRNA (miR)­211­5p. The expression levels of TTN­AS1 and miR­211­5p, which was predicted to be targeted by TTN­AS1, in TNBC tissues and in the breast cancer cell lines MDA­MB­453 and MDA­MB­231 were measured using reverse transcription­quantitative PCR. Following TTN­AS1­knockdown, cell proliferation was measured using a Cell Counting Kit­8 assay and colony formation assay, whereas cell invasion and migration were measured using Transwell and wound healing assays, respectively. Luciferase reporter assay was performed to verify the potential interaction between TTN­AS1 and miR­211­5p. In addition, rescue assays were conducted to investigate the effects of TTN­AS1 and miR­211­5p on TNBC development. The results demonstrated that TTN­AS1 expression was significantly upregulated, whereas that of miR­211­5p was found to be downregulated in TNBC tissues and cell lines compared with the matched adjacent normal tissues and normal breast epithelial cell line MCF­10A, respectively. Furthermore, TTN­AS1­knockdown inhibited the proliferation and invasive and migratory abilities of MDA­MB­453 and MDA­MB­231 cells, which was reversed following co­transfection with the miR­211­5p inhibitor. The results from luciferase reporter assay confirmed that miR­211­5p was a direct target of TTN­AS1, suggesting that TTN­AS1 may bind directly to miR­211­5p to negatively regulate its expression. In conclusion, the findings from the present study demonstrated that TTN­AS1 regulated the proliferation and invasive and migratory abilities of TNBC by targeting miR­211­5p. This study may provide some insights into the regulatory mechanism of TNBC and help the development of novel therapeutic interventions for TNBC.

Application of leukocyte subsets and sperm DNA fragment rate in infertile men with asymptomatic infection of genital tract.

BACKGROUND: About 15% of male infertility is due to genital tract infection and inflammation, some of them have no clinical symptoms, but manifested as leukocytospermia (LCS). Leukopenia will lead to functional impairment of male sperm and integrity damage of sperm morphology. A large amount of reactive oxygen species (ROS) produced by leukocytes can damage sperm nuclear DNA. The aim of this study was to investigate the correlation between leukocyte subsets and sperm DNA fragmentation rate in semen of infertile men with asymptomatic infection of genital tract. METHODS: One hundred and eight cases of infertile men were enrolled, who were admitted to our hospital from May 2016 to September 2018, and all had genital tract infections. After routine sperm analysis, realtime PCR was performed for detecting the infection of chlamydia trachoma (CT) and Ureaplasma urealyticum (UU). Furthermore, total leukocyte count in semen was evaluated by detection of CD45 molecules using immunocytochemistry. Flow cytometry was used for subset analysis, monocyte/macrophages were evaluated by CD14, and activated macrophages were evaluated by HLA-DR antigen. Sperm DNA fragmentation index (DFI) were evaluated by SCD method and 8-hydroxydeoxyguanosine (8-OHdG) expression were evaluated by chromatin diffusion method and TUNEL method; the correlation analysis was conducted between semen leukocyte subsets, sperm DNA fragment rate and conventional semen parameters. RESULTS: There was a significant correlation among the concentrations of cells expressing HLA-DR antigen and those expressing CD14 (P<0.01), but the concentrations of differential leukocyte subsets all had no significant correlation with sperm DFI, the percentage of 8-OHdG-expressing cells and routine semen parameters. The percentage of 8-OHdG-expressing sperm was positively correlated with the percentage of sperm fragments (r=0.42, P<0.01), and negatively correlated with sperm concentration (r=-0.32, P<0.01). After adjustment for possible confounders including age, abstinence time and smoking, the percentage of 8-OHdG-expressing sperms independently associated with sperm concentration (ß=-0.30; P=0.006) and DFI (ß=0.180, P=0.06). CONCLUSIONS: Among infertile men with genital tract infection, the sperm DFI is associated with decreased semen quality and not the concentration of differential leukocyte subsets.

Potential effects of COVID-19 on reproductive health: a mini review.

Coronavirus disease 2019 (COVID-19) is now a major public health problem worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity is extremely strong. One major target of the virus is the lung, which can lead to death due to the development of respiratory distress syndrome and even multiple system organ failure. The possible pathophysiology by which SARS-CoV-2 affects the object is by way of the receptor, angiotensin-converting enzyme 2 (ACE2). From the study of the viral structure and infection mechanisms, researchers have discovered that the ACE2 acts as a receptor for SARS-CoV-2. According to previous studies, ACE2 is one of the key enzymes in the RAS system. Physiological functions can be found in angiosarcomas and in the kidney, liver, intestine and so on. Whether SARS-CoV-2 infection leads to male fertility impairment has recently received attention. Nevertheless, the association between SARS-CoV-2 infection and reproductive health is currently poorly understood. Using key words including "SARS-CoV-2", "reproductive health", "ACE2" and "2019-nCoV", we retrieved original articles and reviews from the PubMed and WEB OF SCI databases published before December 16, 2020 and performed a thorough review of them. Compared with females, we discovered that infected person with SARS-CoV-2 was higher in males. Men who were infected with SARS-CoV-2 may be easy to suffer from impaired reproductive health. These investigations would help for a comprehensive grasp of the relationship between SARS-CoV-2 infection and reproductive health.

Research progress in molecular biology related quantitative methods of MicroRNA.

MicroRNAs (miRNAs) are small RNAs of 18-25 nucleotides in length that are widely distributed in eukaryotes and are produced by DNA transcription. As regulators of post-transcriptional gene expression, it plays an important role in the physiological processes of cells. As some miRNAs in the body are abnormally expressed at different and earlier stages of diseases, this phenomenon suggests that accurate, sensitive and specifical detection of them can be helpful for early and differential diagnosis. To expound the technological progress of miRNA detection, we reviewed all the related articles in PubMed database published before May 6, 2019, with the following keywords: "miRNA", "real-time fluorescent quantitative PCR", "electrochemical detection", "next-generation sequencing", "digital PCR technology". Original articles and reviews on the topics were selected. The present methods established for quantitative detection of miRNAs mainly relies on various probe design and labeling techniques, and the improvement of the sensitivity and specificity of detection is often through combination of microarray chips, real-time fluorescent quantitative PCR, high-throughput sequencing and other techniques. This paper combines the existing microRNA detection methods to provide a reference for researchers to choose the best detection method.