Susceptibility to chronic immobilization stress-induced depressive-like behaviour in middle-aged female mice and accompanying changes in dopamine D1 and GABAA receptors in related brain regions.

BACKGROUND: Middle-aged females, especially perimenopausal females, are vulnerable to depression, but the potential mechanism remains unclear. Dopaminergic and GABAergic system dysfunction is involved in the pathophysiology of depression. In the current study, we used 2-month-old and 11-month-old C57BL/6 mice as young and middle-aged mice, respectively. Chronic immobilization stress (CIS) was used to induce depressive-like behaviour, and the sucrose preference test (SPT), tail suspension test (TST) and forced swim test (FST) were used to assess these behaviours. We then measured the mRNA levels of dopamine receptor D1 (DRD1) and the GABAA receptors GABRA1, GABRB2 and GABRG2 in the nucleus accumbens (NAc) and prefrontal cortex (PFC). RESULTS: We found that immobility time in the FST was significantly increased in the middle-aged mice compared with the middle-aged control mice and the young mice. In addition, the preference for sucrose water was reduced in the middle-aged mice compared with the middle-aged control mice. However, CIS did not induce obvious changes in the performance of the young mice in our behavioural tests. Moreover, the middle-aged mice exhibited equal immobility times as the young mice in the absence of stress. Decreases in the mRNA levels of DRD1, GABRA1, and GABRB2 but not GABRG2 were found in the NAc and PFC in the middle-aged mice in the absence of stress. Further decreases in the mRNA levels of DRD1 in the NAc and GABRG2 in the NAc and PFC were found in the middle-aged mice subjected to CIS. CONCLUSIONS: Our results suggested that ageing could not directly induce depression in the absence of stress. However, ageing could induce susceptibility to depression in middle-aged mice in the presence of stress. CIS-induced decreases in DRD1 and GABRG2 levels might be involved in the increase in susceptibility to depression in this context.

A comprehensive analysis of listeriosis in 13 pregnant women and 27 newborns in Xi'an from 2011 to 2020.

Background: Listeriosis is a severe foodborne infection associated with high mortality. Pregnant women and newborns are at a particularly high risk of infection. However, the data on epidemiology of maternal-neonatal listeriosis in Xi'an are little known. The aim of this study was to investigate the epidemiological and clinical features of maternal-neonatal listeriosis in Xi'an. Methods: A total of 40 cases of listeriosis confirmed by positive cultures [blood or cerebrospinal fluid (CSF)] and admitted to the Northwest Women's and Children's Hospital (NWCH) from 2011 to 2020 were enrolled. Data from all patients were collected from the hospital's electronic medical records. Data analysis and epidemiological investigation were carried out by demographic information, time of onset, clinical and laboratory characteristics. Descriptive statistical indicators were obtained using SPSS21.0 and were expressed as median, mean, standard deviation and interquartile range. Results: The incidence of maternal and neonatal listeriosis in NWCH over the last decade was 5/100,000 and 10.4/100,000 respectively and Listeriosis was more likely to occur in spring and summer. The most common symptom was as follows: (I) maternal: fever (85%), abdominal pain (77%), vaginal fluid or colporrhagia (46%); (II) neonatal: respiratory distress (52%), fever (33%). Laboratary results were as follows: (I) maternal: elevated C-reactive protein (CRP) (100%), white blood cells (WBC) or neutrophil (NEUT#) (85%), and monocyte counts (MONO#) (77%); (II) neonatal: increased WBC (81%), MONO# (81%), CRP (78%), NEUT# and lymphocytes (73%); and elevated protein (PRO) (95%) and WBC count (86%) in CSF while decreased in glucose (GLU) (73%). Compared to neonatal group, the ratio of neutrophils to lymphocytes in maternal group raise to a higher level (92% to 42%). The outcomes of maternal were favorable and 54% of them suffered acute chorioamnionitism. Yet neonatal deaths account for up to 33%. Conclusions: Listeriosis is a rare disease with extremely variable clinical characteristics in Xi'an. Our data indicated that unexplained fever, abdominal pain, signs of premature and respiratory symptoms accompanied by a progressive increase in WBC, CRP, NEUT#, MONO# even include WBC and PRO in CSF while GLU decreased, the possibility of an LM infection should be considered.

Laboratory analysis of positive rate of Mycoplasma pneumoniae antibody among 53,273 children with respiratory tract infections in Xi'an from 2017 to 2020.

Background: Mycoplasma pneumoniae (Mp) is an important pathogen that causes respiratory tract infections in children. Data on epidemiology of paediatric Mp infection in China are little known. The aim of this study was to investigate the infection of children with respiratory tract infection in Xi'an from 2017 to 2020, and to explore the epidemiological features of paediatric Mp infection in Northwest China during the past 4 years. Methods: A total of 53,273 paediatric patients diagnosed with respiratory tract infection as the first diagnosis were enrolled. Mp antibody was detected using passive agglutination method. Statistical analysis and epidemiological investigation were carried out on the test results according to different years, seasons, ages and genders. The differences among rates were analyzed by the χ2 test. The trends among the rates were analyzed by the Poisson regression. Results: A total of 14,375 Mp antibody positive patients were detected, with a total positive rate of 26.98%. The rate of Mp infection in 2017 was significantly higher than other years (χ2=431.700; P=0.000), and the rate showed a downward trend year by year [incidence rate ratios (IRR) =0.906; 95% CI: 0.892-0.921; P=0.000]. The rate of Mp infection increased gradually in the order of spring, summer, autumn and winter (IRR =1.078; 95% CI: 1.060-1.097; P=0.000), and peaked in winter (29.08%). As age increased, the positive rate of Mp infection also gradually increased (IRR =1.138; 95% CI: 1.134-1.143; P=0.000). The peak age of Mp infection was between 6 and 12 years, accounting for 51.71%, significantly more compared with other age groups (χ2=4203.000, P=0.000). Female children had significantly higher positive rates than male children (χ2=527.000; P=0.000). Conclusions: Mp infection mainly occurs related to year, season, age and gender. Understanding the epidemiological characteristics of paediatric Mp infection can contribute to timely treatment and diagnosis, and may improve the prognosis of children with Mp infection.

Interference by Rheumatoid Factor in Immunoglobulin M-Class Herpes Simplex Virus Types 1 + 2 Immunoassays.

Herpes simplex virus (HSV) types 1 + 2 immunoglobulin (Ig)M antibodies assays are important tools for diagnosing pregnant women and their newborns. However, it is unclear whether high levels of rheumatoid factor (RF) interfere with serological methods used to test for HSV types 1 + 2 type-specific IgM antibodies. We report a case of a false-positive result for HSV 1 + 2 IgM antibodies due to gross overestimation of RF by enzyme-linked immunosorbent assay (ELISA). This result occurred in a 25-year-old Han Chinese woman who was 28 weeks pregnant with a fetus (sex of fetus unknown). Antinuclear antibody (ANA) screening was performed, and RF-absorbent material was used. Test results for 3 antibodies of ANA (SSA, Ro-52, and SSB) were positive; the rest of the results were negative. Also, RF levels were significantly higher than normal, as measured by ANA screening. We observed an obvious decrease in HSV 1 + 2 IgM antibodies after removal of RF. Based on our findings, the presence of high concentrations of RF may be responsible for false-positive HSV 1 + 2 ELISA results.