Single-cell analysis reveals the function of lung progenitor cells in COVID-19 patients

The high mortality of severe 2019 novel coronavirus disease (COVID-19) cases is mainly caused by acute respiratory distress syndrome (ARDS), which is characterized by increased permeability of the alveolar epithelial barriers, pulmonary edema and consequently inflammatory tissue damage. Some but not all patients showed full functional recovery after the devastating lung damage, and so far there is little knowledge about the lung repair process1. Here by analyzing the bronchoalveolar lavage fluid (BALF) of COVID-19 patients through single cell RNA-sequencing (scRNA-Seq), we found that in severe (or critical) cases, there is remarkable expansion of TM4SF1+ and KRT5+ lung progenitor cells. The two distinct populations of progenitor cells could play crucial roles in alveolar cell regeneration and epithelial barrier re-establishment, respectively. In order to understand the function of KRT5+ progenitors in vivo, we transplanted a single KRT5+ cell-derived cell population into damaged mouse lung. Time-course single-cell transcriptomic analysis showed that the transplanted KRT5+ progenitors could long-term engrafted into host lung and differentiate into HOPX+ OCLN+ alveolar barrier cell which restored the epithelial barrier and efficiently prevented inflammatory cell infiltration. Similar barrier cells were also identified in some COVID-19 patients with massive leukocyte infiltration. Altogether this work uncovered the mechanism that how various lung progenitor cells work in concert to prevent and replenish alveoli loss post severe SARS-CoV-2 infection.

Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCov

A novel coronavirus SARS-CoV-2 was identified in Wuhan, Hubei Province, China in December of 2019. According to WHO report, this new coronavirus has resulted in 76,392 confirmed infections and 2,348 deaths in China by 22 February, 2020, with additional patients being identified in a rapidly growing number internationally. SARS-CoV-2 was reported to share the same receptor, Angiotensin-converting enzyme 2 (ACE2), with SARS-CoV. Here based on the public database and the state-of-the-art single-cell RNA-Seq technique, we analyzed the ACE2 RNA expression profile in the normal human lungs. The result indicates that the ACE2 virus receptor expression is concentrated in a small population of type II alveolar cells (AT2). Surprisingly, we found that this population of ACE2-expressing AT2 also highly expressed many other genes that positively regulating viral entry, reproduction and transmission. This study provides a biological background for the epidemic investigation of the COVID-19, and could be informative for future anti-ACE2 therapeutic strategy development.

Design and application of medical electric leg-raising machine / 中华危重病急救医学

Passive leg raising is widely used in clinic, but it lacks of specialized mechanical raise equipment. It requires medical staff to raise leg by hand or requires a multi-functional bed to raise leg, which takes time and effort. Therefore we have developed a new medical electric leg-raising machine. The equipment has the following characteristics: simple structure, stable performance, easy operation, fast and effective, safe and comfortable. The height range of the lifter is 50-120 cm, the range of the angle of raising leg is 10°-80°, the maximum supporting weight is 40 kg. Because of raising the height of the lower limbs and making precise angle, this equipment can completely replace the traditional manner of lifting leg by hand with multi-functional bed to lift patients' leg and can reduce the physical exhaustion and time consumption of medical staff. It can change the settings at any time to meet the needs of the patient;can be applied to the testing of PLR and dynamically assessing the hemodynamics; can prevent deep vein thrombosis and some related complications of staying in bed; and the machine is easy to be cleaned and disinfected, which can effectively avoid hospital acquired infection and cross infection; and can also be applied to emergency rescue of various disasters and emergencies.

Diagnosis value on four biochemical indicator detection for the early renal impairment in multiple myeloma patients / 国际检验医学杂志

Objective To explore the changes and comparisons of the four biochemical indicator detection for the early renal im‐pairment in multiple myeloma patients .Methods The 54 patients with multiple myeloma of early onset(MM group) and 54 healthy peoples(control group) were retrospectively analyzed .The levels of serum Cystatin C(Cys C) ,creatinine(Cr) ,β2‐microglobulin(β2‐MG) ,and lactate dehydrogenase(LDH) were detected .And the results for statistical analysis .Results The levels of serum Cys C , Cr ,β2‐MG and LDH were higher significantly in the MM group than in the control group ,the difference was statistically significant (P<0 .05) .In the MM group ,the positive rate of Cys C ,Cr ,β2‐MG ,LDH ,combined detection of Cys C and Cr ,combined detection of β2‐MG and LDH ,combined detection of Cys C ,Cr ,β2‐MG and LDH was 63 .0% ,42 .6% ,74 .1% ,61 .1% ,66 .7% ,85 .2% and 96 .3% respectively .The positive rate of Cys C was higher than Cr ,the difference was statistically significant(P<0 .05) .Between the positive rate of combined detection of β2‐MG ,LDH and Cys C ,Cr ,the difference was statistically significant(P<0 .05) .The positive rate of combined detection of the four biochemical tests was the most highest .Conclusion In the early stage of the renal in‐jury in the patients with MM ,the combined detection of the four biochemical tests is most sensitive to discovery the early stage of the renal glomerular function injury .