Influenza A virus exposure may cause increased symptom severity and deaths in coronavirus disease 2019 / 中华医学杂志(英文版)

BACKGROUND@#The coronavirus disease 2019 (COVID-19) outbreak occurred during the flu season around the world. This study aimed to analyze the impact of influenza A virus (IAV) exposure on COVID-19.@*METHODS@#Seventy COVID-19 patients admitted to the hospital during January and February 2020 in Wuhan, China were included in this retrospective study. Serum tests including respiratory pathogen immunoglobulin M (IgM) and inflammation biomarkers were performed upon admission. Patients were divided into common, severe, and critical types according to disease severity. Symptoms, inflammation indices, disease severity, and fatality rate were compared between anti-IAV IgM-positive and anti-IAV IgM-negative groups. The effects of the empirical use of oseltamivir were also analyzed in both groups. For comparison between groups, t tests and the Mann-Whitney U test were used according to data distribution. The Chi-squared test was used to compare disease severity and fatality between groups.@*RESULTS@#Thirty-two (45.71%) of the 70 patients had positive anti-IAV IgM. Compared with the IAV-negative group, the positive group showed significantly higher proportions of female patients (59.38% vs. 34.21%, χ = 4.43, P = 0.035) and patients with fatigue (59.38% vs. 34.21%, χ = 4.43, P = 0.035). The levels of soluble interleukin 2 receptor (median 791.00 vs. 1075.50 IU/mL, Z = -2.70, P = 0.007) and tumor necrosis factor α (median 10.75 vs. 11.50 pg/mL, Z = -2.18, P = 0.029) were significantly lower in the IAV-positive group. Furthermore, this group tended to have a higher proportion of critical patients (31.25% vs. 15.79%, P = 0.066) and a higher fatality rate (21.88% vs. 7.89%, P = 0.169). Notably, in the IAV-positive group, patients who received oseltamivir had a significantly lower fatality rate (0 vs. 36.84%, P = 0.025) compared with those not receiving oseltamivir.@*CONCLUSIONS@#The study suggests that during the flu season, close attention should be paid to the probability of IAV exposure in COVID-19 patients. Prospective studies with larger sample sizes are needed to clarify whether IAV increases the fatality rate of COVID-19 and to elucidate any benefits of empirical usage of oseltamivir.

Effects of epithelial cell injury of the lower respiratory tract in the pathogenesis of allergic responses in a rat model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Asthma is a complex disease involving genetic and environment interactions. Atopy is a strong risk factor for asthma. The airway epithelium not only forms a physical barrier but also provides immune defense against harmful materials. To explore the effects of airway epithelium on asthma, we hypothesized that environmental injuries could act on bronchial epithelial cells and damage the physical barrier, which might facilitate allergens to stimulate immunoreactions and play an important role in the pathogenesis of asthma.</p><p><b>METHODS</b>Thirty eight-week-old male Wistar rats were randomly divided into five groups with six rats in each group: control group, asthma group, ovalbumin (OVA) + OVA group, lipopolysaccharide (LPS) group and LPS + OVA group. In the control group, 0.9% saline was injected intraperitoneally on day 1. Fourteen days later, the rats were exposed to aerosolized 0.9% saline. In the asthma group, the rats were sensitized with an injection of 10 mg of OVA, followed by an aerosolized 2% OVA challenge 14 days later. The OVA + OVA group was sensitized by an inhalation 2% OVA, 20 minutes a day, from day 1 to day 7, and then OVA challenged in the same way as the asthma group. In the LPS group, LPS (200 µl, 1 µg/µl) was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with saline as in the control group. While in the LPS + OVA group, LPS (200 µl, 1 µg/µl) was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with OVA as in the asthma group. The expression of interleukin (IL)-4, interferon-gamma (IFN-γ) and thymic stromal lymphopoietin (TSLP) in the lungs was detected by reverse transcription polymerase chain reaction (RT-PCR) and the pulmonary pathological changes were also observed. The level of IL-4, IFN-γ and IgE in plasma was detected by enzyme-linked immunosorbent assay (ELISA). Bronchoalveolar lavage fluid (BALF) was collected to conduct differential cell counts. Flow cytometry analysis was also used to count Th1 and Th2 cells.</p><p><b>RESULTS</b>The pathological changes in the LPS + OVA group were similar to the asthma group, while in other groups, the pathological changes were not obvious. The ratio of lymphocytes in BALF, IL-4/IFN-γ in plasma and the expression of the TSLP and IL-4 in the asthma and LPS + OVA groups were higher than in the control group and the OVA + OVA group (P < 0.05). The level of IgE was higher in the asthma, LPS and LPS + OVA groups than in the control group and the OVA + OVA group (P < 0.05). By flow cytometry analysis, the Th1/Th2 ratio was lower in the LPS + OVA and asthma groups than in other groups (P < 0.05).</p><p><b>CONCLUSIONS</b>The experiment results show that the injury to the bronchial epithelial layer may be the initial event of allergic responses. This finding implies that a rational approach to therapeutics would be to increase the resistance of the airways to environmental injuries rather than concentrating on suppressing inflammation.</p>

The "time-window" effect of early allergen exposure on a rat asthma model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The hygiene hypothesis has been proposed to explain the pathogenesis of asthma. Allergen exposure was shown to inhibit asthma in an animal model. But the optimal timing of allergen exposure remains unclear. This study aims to explore the time effcct of allergen exposure and the possible mechanisms.</p><p><b>METHODS</b>Neonate Wistar rats were randomly divided into asthma group, control group and day 1, day 3, day 7, and day 14 groups. The day 1, day 3, day 7 and day 14 groups were injected with ovalbumin (OVA) subcutaneously on days 1, 3, 7 and 14 after birth, respectively. Six weeks later, all groups, except the control group, were sensitized and stimulated with OVA to make the asthma model. We observed the pulmonary pathologic changes, detected the regulatory T cells, and CD28 expression level in thymus and spleen by flow cytometry.</p><p><b>RESULTS</b>The asthmatic inflammation in the day 1, day 3 and day 7 groups, but not the day 14 group, was alleviated. The asthma group and day 14 group had lower proportions of regulatory T cells in the thymus compared with the control group, day 1, day 3, and day 7 groups. There was no significant difference in the CD28 expression levels on the regulatory and conventional T cells among groups. But the control group and the day 1, day 3, and day 7 groups had relatively higher proportions of CD28 positive regulatory T cells in the thymus than the day 14 group and the asthma group.</p><p><b>CONCLUSIONS</b>There is a "time-window" for early allergen exposure. The impairment of regulatory T cells may promote the development of asthma. Allergen exposure in the "time-window" can make the thymus produce normal quantity of regulatory cells. The CD28 signal on regulatory T cells may participate in the production of regulatory T cells.</p>

Evaluation of intracranial aneurysms using dual-source computed tomographic angiography and digital subtraction angiography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the values of dual-source computed tomographic angiography (DSCTA) and digital subtraction angiography (DSA) in evaluating intracranial aneurysms in patients with nontraumatic subarachnoid hemorrhages (SAH) .</p><p><b>METHODS</b>Totally 80 nontraumatic SAH patients were evaluated with both DSCTA and DSA. With the results of DSA as the gold standards, the sensitivity, specificity, and accuracy of DSCTA was calculated, and the agreement between these two modes was analyzed.</p><p><b>RESULTS</b>A total of 73 aneurysms were detected by DSCTA in 65 patients, 74 aneurysms were detected by DSA in 63 patients. 2 cases were false positive and 3 aneurysms were missed by DSCTA. The sensitivity, specificity and accuracy of DSCTA were 95.5%, 88.2%, and 94% on a per-patient basis and were 95.9%, 88.2%, and 94.5% on a per-aneurysm basis.</p><p><b>CONCLUSION</b>For patients with nontraumatic SAH, DSCTA and DSA have comparable abilities in detecting and displaying aneurysms.</p>

Effects of N-acetylcysteine on Clara cells in rats with cigarette smoke exposure / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The number of Clara cells and the Clara cell 16-kDa protein (CC16) levels of the lung decrease in patients with chronic obstructive pulmonary disease (COPD). N-acetylcysteine (NAC) is a powerful antioxidant and can reduce the frequency of acute exacerbations of COPD. But the exact mechanism is unclear. The present study was designed to investigate the effects of NAC on Clara cells in rats with cigarette smoke exposure.</p><p><b>METHODS</b>Eighteen adult male Wistar rats were randomly divided into 3 groups, 12 exposed to cigarette smoke (CS) thrice a day, 10 cigarettes for 30 minutes each time for 1 week, without (CS group) or with (CS + NAC group) oral intake of NAC 80 mg x kg(-1) x d(-1), and another 6 rats exposed to fresh air (control group). Clara cells were observed by an electron microscope. The mRNA expression of CC16 and CC16 protein in lungs were determined by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry respectively. The glutathion (GSH) level in plasma and lung tissue were tested by fluorimetry assay.</p><p><b>RESULTS</b>Compared with the controls, the pathologic score of small airways significantly increased in the CS exposed rats (20.3 +/- 14.7 vs. 53.7 +/- 11.5, P < 0.05). The Clara cell particles in cytoplasm decreased in the CS group (P < 0.05). The percentage of CC16-positive cells in bronchioles in the CS group (27.8 +/- 4.3 and 29.5 +/- 2.4 in terminal bronchioles and respiratory bronchioles, respectively) significantly decreased as compared with the control group (37.1 +/- 3.8 and 43.8 +/- 5.8 in terminal bronchioles and respiratory bronchioles, respectively) (P < 0.05). No significant difference was observed in GSH level ((181 +/- 26) nmol/L in the control group vs. (170 +/- 18) nmol/L in the CS group) between the two groups. After treatment with NAC, the pathologic score of small airways (24.1 +/- 17.5) decreased (P < 0.05). Clara cell particles in cytoplasm of Clara cells increased and GSH level in plasma ((213 +/- 40) nmol/L vs. (170 +/- 18) nmol/L in the CS group) increased too (P < 0.05), while the increase in the proportions of CC16 positive cells in bronchioles (30.1 +/- 6.4 and 34.3 +/- 6.3 in terminal bronchioles and respiratory bronchioles, respectively) did not reach the statistical significance (P > 0.05). No significant difference was found in the expression of CC16 mRNA among the three groups. Correlation analysis indicated that the percentage of CC16-positive cells in bronchioles negatively correlated with the pathologic score of small airways (r = -0.592, P < 0.05), but not with GSH level.</p><p><b>CONCLUSIONS</b>One-week CS exposure decreased the number of Clara cells and the expression of CC16 in bronchioles in rats. NAC might provide protection of the Clara cells from oxidative damage and possibly through the elevation of the synthesis and secretion of CC16. These data indicate that NAC decreases airway inflammation induced by CS via induction of CC16.</p>

Nifedipine modifies plasma membrane functional integrity and inhibits osmosensitive calcium influx in human sperm / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of nifedipine of therapeutic dosage on the plasma membrane functional integrity and osmosensitive calcium influx in human sperm in vitro.</p><p><b>METHODS</b>Sperm samples were aseptically obtained from 10 healthy fertile men by masturbation and prepared by swim-up technique to produce a spermatozoal solution of high motility. The solution was then incubated with nifedipine of 20, 100 and 20 x 10(3) ng/ml respectively at 37 degrees C in vitro. The hypo-osmotic swelling (HOS) test was done to assess the sperm function. Intracellular calcium concentration was measured by fluorescent probe fura-2/AM before and after sperm medium dilution in distilled water.</p><p><b>RESULTS</b>The 20 x 103 ng/ml group showed significantly lower HOS scores than the control (P < 0.01). The 20, 100 and 20 x 10(3) ng/ml groups all showed significantly lower Ca2+ fluorescence D-value than the control (P < 0.01).</p><p><b>CONCLUSION</b>Nifedipine can modify plasma membrane functional integrity and inhibit osmosensitive calcium influx in human sperm and affect male fertility in vitro in therapeutic dose.</p>