The role of DNA damage in neural stem cells ageing.

Neural stem cells (NSCs) are pluripotent stem cells with the potential to differentiate into a variety of nerve cells. NSCs are susceptible to both intracellular and extracellular insults, thus causing DNA damage. Extracellular insults include ultraviolet, ionizing radiation, base analogs, modifiers, alkyl agents and others, while intracellular factors include Reactive oxygen species (ROS) radicals produced by mitochondria, mismatches that occur during DNA replication, deamination of bases, loss of bases, and more. When encountered with DNA damage, cells typically employ three coping strategies: DNA repair, damage tolerance, and apoptosis. NSCs, like many other stem cells, have the ability to divide, differentiate, and repair DNA damage to prevent mutations from being passed down to the next generation. However, when DNA damage accumulates over time, it will lead to a series of alterations in the metabolism of cells, which will cause cellular ageing. The ageing and exhaustion of neural stem cell will have serious effects on the body, such as neurodegenerative diseases. The purpose of this review is to examine the processes by which DNA damage leads to NSCs ageing and the mechanisms of DNA repair in NSCs.

Assessing airborne transmission risks in COVID-19 hospitals by systematically monitoring SARS-CoV-2 in the air.

IMPORTANCE: Risk management and control of airborne transmission in hospitals is crucial in response to a respiratory virus pandemic. However, the formulation of these infection control measures is often based on epidemiological investigations, which are an indirect way of analyzing the transmission route of viruses. This can lead to careless omissions in infection prevention and control or excessively restrictive measures that increase the burden on healthcare workers. The study provides a starting point for standardizing transmission risk management in designated hospitals by systemically monitoring viruses in the air of typical spaces in COVID-19 hospitals. The negative results of 359 air samples in the clean and emergency zones demonstrated the existing measures to interrupt airborne transmission in a designated COVID-19 hospital. Some positive cases in the corridor of the contaminant zone during rounds and meal delivery highlighted the importance of monitoring airborne viruses for interrupting nosocomial infection.

[Study on the extracorporeal membrane oxygenation inter-hospital transport during coronavirus disease 2019 epidemic: based on the transport experience of 6 cases of severe H1N1 influenza virus pneumonia on extracorporeal membrane oxygenation].

OBJECTIVE: To provide a reference for extracorporeal membrane oxygenation (ECMO) inter-hospital transport during coronavirus disease 2019 (COVID-19), based on the transport experience of 6 patients with severe H1N1 influenza virus pneumonia using ECMO. METHODS: Clinical data of patients with severe H1N1 influenza virus pneumonia implemented by ECMO in the First Affiliated Hospital of Wannan Medical College from October 2018 to December 2019 were retrospective analyzed, including general information, ECMO transport distance, time, clinical parameters before and after ECMO, including the patients' oxygenation index (PaO2/FiO2), respiratory rate (RR), pulse blood oxygen saturation (SpO2), arterial blood carbon dioxide partial pressure (PaCO2), and pH value, various complications during transport, mechanical ventilation time, patients' prognosis and other indicators. Experience from the aspects of personal protection, transport process and equipment, team cooperation, mid-transit monitoring, quality control, etc., was summarized to provide suggestions for patients with severe COVID-19 using ECMO during inter-hospital transport and protection. RESULTS: A total of 6 patients with severe H1N1 influenza virus pneumonia were transported on ECMO. All patients were transported to the intensive care unit (ICU) of the First Affiliated Hospital of Wannan Medical College by the ECMO transport team after the establishment of ECMO in the local hospital. The transfer distance was 11 to 197 km, with an average of (93.8±58.6) km; the transfer time was 30 to 150 minutes, with an average of (79.2±40.6) minutes. Two patients experienced a drop in ECMO flow and SpO2 during the process, and the main reason was insufficient volume, which was improved after fluid resuscitation and posture adjustment. All patients maintained SpO2 above 0.93. Six patients survived and were discharged. ECMO assisted time was 4-9 days, with an average of (6.5±1.5) days; mechanical ventilation time was 7-24 days, and median time was 10.0 (8.0, 14.5) days. No H1N1 transmission occurred in medical personnel. To achieve good therapeutic effect, the main experience was to choose the proper timing and mode of ECMO; intact transportation vehicles and equipment to reduce or avoid mechanical complications; the effective management of respiration and circulation during the transportation to avoid ventilation-associated lung injury (VALI) and serious hypoxemia; the appropriate space for the transfer team to quickly handle various critical situations; and personal protection to avoid infection. CONCLUSIONS: With an experienced ECMO transport team, good transport equipment, comprehensive protection measures, reasonable transport procedures, and a perfect emergency plan, it is safe to use ECMO transport for COVID-19 patients.

Cryosurvival and pregnancy rates: One-step protocol for freezing-thawing Shangri-la Yak (Bos grunniens) Embryos.

The yak is one of the most important and economically useful animals for highlanders. The decline in the yak population requires effective measures for the conservation and multiplication of elite germplasm. A standardized protocol will simplify the freezing and warming of yak embryos in straw and facilitate embryo transfer. In this work, we investigated a one-step protocol that uses a stable basal medium, which comprised a warming medium (1.08 M sucrose) and a freezing medium (EFS40). We also assessed the effects of the new transfer method on embryo survival. A total of 145 yak frozen embryos were thawed in a standard medium system. The one-step protocol led to a high recovery percentage (84.93) of yak embryos that survived vitrification and warming. The in vitro survival rates of these embryos significantly different from those of embryos frozen-thawed via the conventional method. The 95 embryos frozen-thawed via our one-step protocol were then implanted in selected recipients. Thirty-six singleton pregnancies were established. In conclusion, the proposed one-step method is a simple, safe, and standardized freezing-thawing protocol that ensures embryo survival and quality under field conditions. This study establishes new possibilities for the widespread use of embryo transfer in yaks.

Hemorrhagic pleural effusion related to acquired coagulation factor VIII deficiency: A case report.

A patient with acquired hemophilia A (AHA) with hemorrhagic pericardial effusions was admitted to Xiamen Chang Gung Hospital (Xiamen, China) in August 2015. The patient had been experiencing progressive dyspnea for 1 week. Bloody effusion (~6.3 l) was drained from the membrane surrounding the heart over a period of 20 days. Biochemical, cytological and radiological examinations were unable to elucidate the reason for the effusion. Coincidentally, it was discovered that activated partial thromboplastin time prolongation could not be corrected by plasma mixing. Furthermore, immunologic and functional assays identified that the patient had factor VIII-deficient plasma. Finally, the coagulopathy was treated by infusion of cryoagglutinin and steroids to eradicate the coagulation inhibitor. The production of cardiac bloody effusions did not recur. Notably, the patient was diagnosed with AHA accompanied by the rare complication of pericardial effusions. The present case was the first to report AHA with the complication of pericardial effusions.