[Research on the framework of biosafety standards for pathogenic microbial laboratories].

Developing and implementing biosafety standards for pathogenic microbiology laboratories is essential to achieving scientific, efficient, and standardized management and operation. This article analyzes the current standardization construction in biosafety in pathogenic microbiology laboratories domestically and internationally. It proposes a framework for the biosafety standard system of pathogenic microbiology laboratories, which mainly includes four parts: basic standards, management standards, technical standards, and industry applications. It provides a reference for the standardization work of pathogenic microbiology laboratories and helps to standardize the biosafety industry in China.

[Association between anti-tissue transglutaminase antibody titers and duodenal histopathology among adults with celiac disease].

To evaluate the association between serum anti-tissue transglutaminase antibody (anti-tTG) titers and the severity of histological damage to the duodenal mucosa and to predict a possible anti-tTG cutoff value for diagnosing celiac disease (CD) and villous atrophy in the domestic population. Clinical and pathological data from 76 adult CD patients with positive anti-tTG titers and duodenal biopsy results who were treated at the People's Hospital of Xinjiang Uygur Autonomous Region from July 2017 to January 2022 were retrospectively analyzed. The correlation between anti-tTG titers and the severity of duodenal mucosal damage was statistically assessed to predict the optimal anti-tTG titer cut-off value for diagnosing CD and villous atrophy. Of the 76 patients, 10 had underlying CD, and of the 66 patients with duodenal histopathology, four were Marsh Ⅰ, six were Marsh Ⅱ, and 56 were Marsh Ⅲa-c grade. In adults with CD, anti-tTG titers were shown to be associated with the severity of histological damage to the duodenal mucosa. When the anti-tTG level was ≥5 times the upper limit of normal (ULN), the sensitivity and specificity for diagnosing CD were 83.9% and 92.9%, respectively. When the anti-tTG titer was ≥8 times the ULN, the sensitivity and specificity for diagnosing villous atrophy were 67.9% and 90.0%, respectively. Anti-tTG levels had a strong predictive value for diagnosing CD in adults when titers exceeded 10 times the ULN. Thus, the anti-tTG cut-off value can be combined with clinical judgment to diagnose CD, limiting the use of invasive endoscopy.

[Establishment and application of a clustered management plan for pulmonary care of massive burn casualties].

Objective: To establish a clustered management plan for pulmonary care of massive burn casualties (hereinafter referred to as the clustered management plan for pulmonary care), and to explore its application effects. Methods: (1) A clustered care intervention group was established, including the medical and nursing staff from the Department of Burns and Plastic Surgery, Department of Respiratory Medicine, and Department of Infection Control at the Fourth Medical Center of PLA General Hospital (hereinafter referred to as our hospital). Four major links, including pulmonary care assessment, chest and lung physical therapy, artificial airway management, and specialized infection control were sorted out according to the key points and difficulties in pulmonary care for massive burn casualties. Evidence-based nursing methods were employed to retrieve articles related to the above-mentioned four links from PubMed, Chinese Journal Full-Text Database, VIP Database and Wanfang Data using terms of " mass burn, respiratory management and airway management" and terms of ",," , and the clustered management plan for pulmonary care was established based on reading and discussion in combination with clinical practice and experience. (2) In this non-randomized controlled study, the clustered management plan for pulmonary care was applied to 73 massive burn patients (48 males and 25 females, aged 32 (25, 38) years) who were admitted to our hospital from January 2016 to December 2019 and met the inclusion criteria, and they were included into the clustered care group; 43 massive burn patients (25 males and 18 females, aged 35 (17, 45) years) who were admitted to our hospital from January 2013 to December 2015, received routine care and met the inclusion criteria were retrospectively included into routine care group. The pulmonary infection rate and mortality of patients in the two groups were recorded during the hospital stay. Data were statistically analyzed with chi-square test, Mann-Whitney U test, and independent sample t test. Results: (1) The clustered management plan for pulmonary care included a total of 12 specific measures covering four aspects of pulmonary care. The contents in pulmonary care assessment clearly stated to include the previous medical history, history of injury, respiratory status, hoarseness, pulmonary auscultation, etc. Chest and lung physical therapy included how to guide patients to effectively cough and do pursed lip breathing and abdominal breathing exercise, etc. Artificial airway management specified the preparation for the establishment of artificial airway at clinical reception, the observation index and frequency after tracheotomy, the method of humidification, the method and frequency of sputum suction, and the management of mechanical ventilation, etc. Specialized infection control required to strengthen hand hygiene and ventilator management. (2) The pulmonary infection rate and mortality of patients in the clustered care group were 2.74% (2/73) and 4.11% (3/73), respectively, significantly lower than 25.58% (11/43) and 18.60% (8/43) in routine care group (χ(2)=11.986, 5.043, P<0.05 or P<0.01). Conclusions: The clustered management plan for pulmonary care developed for massive burn casualties focuses on the major links and key points. The measures are systemic and comprehensive, simple but precise, and highly operable, covering the entire process of massive burn care, hereby reducing the pulmonary infection rate significantly and improving the success rate of treatment.

miR-125 family regulates XIRP1 and FIH in response to myocardial infarction.

MicroRNAs (miRNAs) are powerful regulators of protein expression. Many play important roles in cardiac development and disease. While several miRNAs and targets have been well characterized, the abundance of miRNAs and the numerous potential targets for each suggest that the vast majority of these interactions have yet to be described. The goal of this study was to characterize miRNA expression in the mouse heart after coronary artery ligation (LIG) and identify novel mRNA targets altered during the initial response to ischemic stress. We performed small RNA sequencing (RNA-Seq) of ischemic heart tissue 1 day and 3 days after ligation and identified 182 differentially expressed miRNAs. We then selected relevant mRNA targets from all potential targets by correlating miRNA and mRNA expression from a corresponding RNA-Seq data set. From this analysis we chose to focus, as proof of principle, on two miRNAs from the miR-125 family, miR-125a and miR-351, and two of their potential mRNA targets, Xin actin-binding repeat-containing protein 1 (XIRP1) and factor inhibiting hypoxia-inducible factor (FIH). We found miR-125a to be less abundant and XIRP1 more abundant after ligation. In contrast, the related murine miRNA miR-351 was substantially upregulated in response to ischemic injury, and FIH expression correspondingly decreased. Luciferase reporter assays confirmed direct interactions between these miRNAs and targets. In summary, we utilized a correlative analysis strategy combining miRNA and mRNA expression data to identify functional miRNA-mRNA relationships in the heart after ligation. These findings provide insight into the response to ischemic injury and suggest future therapeutic targets.

Tuning interfacial Dzyaloshinskii-Moriya interactions in thin amorphous ferrimagnetic alloys.

Skyrmions can be stabilized in magnetic systems with broken inversion symmetry and chiral interactions, such as Dzyaloshinskii-Moriya interactions (DMI). Further, compensation of magnetic moments in ferrimagnetic materials can significantly reduce magnetic dipolar interactions, which tend to favor large skyrmions. Tuning DMI is essential to control skyrmion properties, with symmetry breaking at interfaces offering the greatest flexibility. However, in contrast to the ferromagnet case, few studies have investigated interfacial DMI in ferrimagnets. Here we present a systematic study of DMI in ferrimagnetic CoGd films by Brillouin light scattering. We demonstrate the ability to control DMI by the CoGd cap layer composition, the stack symmetry and the ferrimagnetic layer thickness. The DMI thickness dependence confirms its interfacial nature. In addition, magnetic force microscopy reveals the ability to tune DMI in a range that stabilizes sub-100 nm skyrmions at room temperature in zero field. Our work opens new paths for controlling interfacial DMI in ferrimagnets to nucleate and manipulate skyrmions.

Sitagliptin improves cardiac function after myocardial infarction through activation of autophagy in streptozotocin-induced diabetic mice.

OBJECTIVE: The aim of this study was to investigate the protective effect of sitagliptin on cardiac function in mice with diabetes and myocardial infarction (MI), and to explore its possible mechanism using the mouse models of diabetes and MI. MATERIALS AND METHODS: The models of diabetes and MI were established using C57BL/6 mice. All mice were randomly divided into 5 groups, including the control sham (CS) group, the control MI (CMI) group, the diabetes sham (DS) group, diabetes + MI (DMI) group and the DMI + sitagliptin (DMI+SGL) group. After modeling, mice in the DMI+SGL group were intragastrically administrated with sitagliptin (10 mg/kg/day) for 21 d and the survival rate of mice was recorded. Before and 7, 14, 21 days after MI, the cardiac function of mice in each group was detected via ultrasound. 21 days after MI, the area of MI was measured via 2,3,5-triphenyl tetrazolium chloride (TTC). Meanwhile, the degree of fibrosis in the peripheral region of MI was determined via Masson staining. Moreover, myocardial autophagosomes of mice in each group were observed by transmission electron microscope (TEM). 7 days after MI, the expressions of autophagy-related proteins LC3II and P65 were detected via Western blotting. The expressions of myocardial inflammatory factors, interleukin-1ß (IL-1ß), IL-6 and tumor necrosis factor-α (TNF-α) were detected via enzyme-linked immunosorbent assay (ELISA). In addition, the expression of nuclear factor-κB (NF-κB) was also detected via Western blotting. RESULTS: Sitagliptin increased survival rate, improved cardiac function, reduced infarction area, alleviated myocardial fibrosis, enhanced autophagy in the peripheral region and inhibited inflammation in the peripheral region in mice with diabetes after MI. CONCLUSIONS: Sitagliptin can improve cardiac function and reduce the mortality rate in diabetic rats after MI. The possible underlying mechanism may be related to the fact that sitagliptin activates autophagy and inhibits inflammatory response in diabetes after MI.

Molecular authentication of Gynostemma pentaphyllum through development and application of random amplification polymorphic DNA sequence-characterized amplified region marker.

Due to the morphological similarities of aerial parts, it is difficult to distinguish Gynostemma pentaphyllum from Cayratia japonica, which is usually an adulterant of the former. To develop a reliable method for the identification and authentication of G. pentaphyllum, a combination of random amplification polymorphic DNA (RAPD) technique with sequence-characterized amplified region (SCAR) markers was studied. Twenty-five samples of G. pentaphyllum and two samples of C. japonica were collected from different regions in Guangxi or bought from different provinces in China. Through the RAPD analysis, significant genetic polymorphism was observed among the intraspecies samples of G. pentaphyllum. Furthermore, a specific marker, J-750, was obtained for authentication. Therefore, the SCAR marker for G. pentaphyllum (359 bp) was developed from the RAPD amplicon. With PCR amplification using the SCAR primers, a specific band of 359 bp was distinctly visible for all tested samples of G. pentaphyllum, but was absent in the samples of C. japonica. Furthermore, the results revealed that the SCAR marker was useful for the identification and authentication of G. pentaphyllum irrespective of whether samples were fresh, dry, or of commercial origin. The SCAR marker obtained in this study successfully authenticated G. pentaphyllum through an integrated PCR system containing SCAR and control primer combinations of two pairs. In addition, it was also used for simultaneous discrimination of G. pentaphyllum from C. japonica.

[Effects of hypoxia on proliferation of pulmonary arterial smooth muscle cells].

AIM: To investigate the effects of hypoxia on the proliferation of different diameter intra-pulmonary artery smooth muscle cells (PASMCs), and to study the possible signal transduction pathway in proliferation caused by hypoxia. METHODS: PASMCs were isolated from three different size of pulmonary arteries (>1 000 microm, 500-800 microm, 300-400 microm diameter) and cultured separately. 3H-TdR incorporation and cell number were used to measure cell proliferation. RESULTS: 3H-TdR incorporation and cell number of PASMCs from three sizes of pulmonary artery (> 1 000 microm, 500-800 microm, 800-400 microm diameter) increased 23.5% and 11.1%, 60.0% and 33.8%, 141.4% and 52.0%, respectively. Calcium antagonist (verapamil), PKC inhibitor (staurosporine), and Na(+)-H+ exchange inhibitor (amiloride) were used in PASMCs isolated from 300-400 microm diameter pulmonary artery. The results showed that verapamil, staurosporine and amiloride could notably block hypoxia-induced increase 3H-TdR incorporation and cell number. CONCLUSION: Proliferation of pulmonary artery smooth muscle cell responded to hypoxia differently according to the artery size; activation of calcium channel, PKC and Na(+)-H+ exchange might mediate the proliferation initiated by hypoxia.

Effects of angiotensin-converting enzyme and angiotensin II on hypoxia-induced proliferation of cultured intra-pulmonary artery smooth muscle cells.

AIM: To investigate whether local angiotensin-converting enzyme (ACE) and endogenous angiotensin II (ANG II) are involved directly in the proliferation of intra-pulmonary artery smooth muscle cells (PASMC) induced by hypoxia. METHODS: Smooth muscle cells isolated from rabbit intra-pulmonary artery (300-400 microns-diameter) were cultured and used in the 3-8 passages. [3H]Thymidine incorporation and cell counts were used to measure PASMC proliferation. RESULTS: Exposure of PASMC to hypoxia for 24 h resulted in an increase in the [3H]thymidine incorporation and cell number by 166.6% and 52.0% as compared with normoxia (P < 0.01). Treatment with either captopril or losartan markedly inhibited the increase, compared with the control, [3H]thymidine incorporation was inhibited by 51.3% (P < 0.01) and 49.8% (P < 0.01) and cell number was inhibited by 22.2% (P < 0.01) and 17.9% (P < 0.01), respectively, while PD-123319 showed no significant effect. CONCLUSION: Local overexpression of PASMC ACE and ANG II play an important role in the proliferation of PASMC induced by hypoxia.

[Effect of hypoxia on angiotensin-converting enzyme activity and gene expression of intrapulmonary artery smooth muscle cells].

In order to observe the effect of hypoxia on pulmonary artery smooth muscle cells (PASMC), angiotensin-converting enzyme (ACE) activity was measured by colometry and the expression of ACE mRNA was detected by Northern blot, using rabbit isolated and cultured PASMC. The main results are as follows: (1) under normoxia both ACE activity and gene expression could be detected in PASMC; and (2) the expression level of ACE mRNA, after an initial latent period of 6 h hypoxia, began to show a marked increase with time in the next 12, 24 and 48 h. Exposure to hypoxia for 24 h resulted in an increase in either culture medium or cell ACE activity, as compared with that under normoxia. The results suggest that PASMC ACE increased by hypoxia might play an important role in the development of hypoxic pulmonary hypertension.

[Effects of hypoxia and anisodamine on products of TXA2 and PGI2 in cultured intra-pulmonary arteriolar smooth muscle cells].

The changes of contents of TXB2 and 6-Keto-PGF1a were studied in severely acute hypoxic cultured intra-pulmonary arteriolar smooth muscle cells (PASMCs) under the action of anisodamine. The results demonstrated that the contents of TXB2 and 6-Keto-PGF1a and their ratio were significantly increased in severe acute hypoxic PASMCs' medium. The content of TXB2 decreased significantly, but the content of 6-Keto-PGF1a was hardly affected by anisodamine under normoxia and hypoxia. These findings suggest that acute and severe hypoxia results in pulmonary vascular constriction through increased production of PASMCs and liberation of TXA2, or PGI2, and increased TXA2/PGI2 ratio. The latter effect of hypoxia could be prevented by anisodamine, which antagonized the effect of hypoxia induced pulmonary vasoconstriction.

[Effect of platelet activating factor on TxA2, PGI2 and Ca(2+)-ATPase activity in the intra-pulmonary artery smooth muscle cells].

The effects of exogenous platelet activating factor (PAF), BN52021 (an antagonist of PAF receptor), indomethacin and verapamil on the production of TxA2, PGI2 and activity of Ca(2+)-ATPase were investigated in rabbit intra-pulmonary smooth muscle cells (PASMCs). The results were as follows: (1) Under basic condition, active AA metablism was present in PASMCs. (2) Significant increase of TxA2 and PGI2 but not their ratio may result from binding of PAF receptor and activation of cyclooxgenase. (3) Activity of Ca(2+)-ATPase could be inhibited by exogenous PAF. (4) The inhibitory effect of PAF on PASMCs Ca(2+)-ATPase could be reversed by verapamil.

[Variation of plasma platelet activating factor during development and reversal of hypoxic pulmonary hypertension in conscious sheep].

A model of hypoxic pulmonary hypertension was made in conscious sheep, and plasma platelet activating factor (PAF) were measured by radioimmunoassay method during the beginning, progression and reversal of hypoxic pulmonary hypertension. The main results were as follows: (1) Under hypoxic condition for 4 days, the conscious sheep develops hypoxemia and marked hypoxic pulmonary vasoconstriction (HPV). These response were reversible. (2) At the beginning of hypoxia, plasma PAF increased, but did not continually increase with hypoxic prolongation and development of HPV. (3) Upon cessation of hypoxia with reversal of pulmonary hypertension, plasma PAF did not show any parallel decrease. These results indicate that plasma PAF is in no way involves in the development of HPV in conscious sheep.

Optical heteroassociative memory using spatial light rebroadcasters.

A new device, a spatial light rebroadcaster, is described that can have optical disk resolution and high speed. Experimental results demonstrate resolution, speed, linearity, logic operation, and arithmetic computation. The device is suitable for optical computing, in particular for memory systems. Optical masking for controlling memory recall and 100 x 100 matrix-vector multiplication are demonstrated. A one pass optical heteroassociative memory system was assembled that uses an optical outer product formulation to store associated 32-bit vectors. Recall is achieved by optical matrix-vector multiplication. The results show the suitability of these devices for memory systems in optical computers.