Diagnostic Value of Metagenomic Next-Generation Sequencing for Pulmonary Infection in Intensive Care Unit and Non-Intensive Care Unit Patients.

Objective: To evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) and culture in pathogen detection among intensive care unit (ICU) and non-ICU patients with suspected pulmonary infection. Methods: In this prospective study, sputum samples were collected from patients with suspected pulmonary infection for 2 consecutive days and then subjected to DNA or RNA sequencing by mNGS or culture; 62 ICU patients and 60 non-ICU patients were admitted. In the end, comparisons were made on the pathogen species identified by mNGS and culture, the overall performance of these two methods in pathogen detection, and the most common pathogens detected by mNGS between the ICU and non-ICU groups. Results: In DNA and RNA sequencing, the positive rate of pathogen detection reached 96.69% (117/121) and 96.43% (108/112), respectively. In culture tests, the positive rate of the pathogen was 39.34% (48/122), much lower than that of DNA and RNA sequencing. In general, the positive rate of pathogen detection by sputum mNGS was significantly higher than that of sputum culture in the total and non-ICU groups (p < 0.001) but did not show a significant difference when compared to the result of sputum culture in the ICU group (p = 0.08). Haemophilus spp., Candida albicans, Enterococcus spp., and viruses from the mNGS results were excluded before comparing the overall performance of these two methods in pathogen detection. Specifically, among the 10 most common bacteria implied from the mNGS results, significant differences were observed in the number of cases of Haemophilus parainfluenzae, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Staphylococcus aureus, and Enterococcus faecalis between the ICU and non-ICU groups (p < 0.05). Conclusions: This study demonstrated the superiority of mNGS over culture in detecting all kinds of pathogen species in sputum samples. These results indicate that mNGS may serve as a valuable tool to identify pathogens, especially for ICU patients who are more susceptible to mixed infections.

Differentiation of mesenchymal stem cells into neural stem cells using cerebrospinal fluid.

Optimization of a methodology for mesenchymal stem cells (MSCs) differentiation into neural stem cells (NSCs) using cerebrospinal fluid (CSF). MSCs were extracted from umbilical cord blood from healthy, full-term, newborn infants and from the bone marrow of patients. CSF was taken from healthy adult volunteers and patients. Four groups investigated were: A (n = 8) cord blood MSC induced with healthy volunteer CSF (control group); B (n = 7): patient MSCs induced with health volunteer CSF; Group C (n = 12): patient MSCs induced with their own CSF; group D (n = 6): cord blood MSCs induced with patient CSF. Following induction, cell differentiation state was examined using microscopy, flow cytometry, and immunohistochemistry. There were significantly more clinically applicable MSCs in Groups B and C than groups A and D (P < 0.05) and Group B had significantly more clinically applicable MSCs than group C (P < 0.05). The presence of NSCs was as with the MSCs. Group B had significantly more clinically applicable NSCs than all of the other groups. In addition, group B cells grew significantly faster than the other groups (P < 0.05). Upon CSF induction, MSCs differentiated into NSCs suitable for clinical treatment. The source of the MSCs and/or CSF influenced the number of NSCs produced and the NSC growth rate. Thus, the source of MSCs and CSF should be considered before initiating a stem cell clinical treatment.

An observational study of autologous bone marrow-derived stem cells transplantation in seven patients with nervous system diseases: a 2-year follow-up.

Currently, autologous bone marrow-derived stem cell is one of the most innovative areas of stem cells research. Previous studies on animal models of nervous system diseases have shown that these cells have a good effect on nervous system disorders. The alternative treatment with stem cells for the nervous system diseases has also gradually reached to clinical application stage. The prospect is captivating, but the safety and efficacy of this procedure need further research. To observe the clinical efficacy and side effects of the treatment for autologous mesenchymal stem cells and neural stem/progenitor cells which are in differentiated form by inducing with cerebrospinal fluid in the patients with nervous system diseases, thirty patients were selected from our hospital (2009-10 to 2012-07) and were followed at 1 month, 3 months, 6 months, 1 year and 2 years after the treatment with autologous mesenchymal stem cells and neural stem/progenitor cells in differentiated form was introduced. In this paper, we will introduce the process to make cells accessible for the clinical application by the description of the changes observed in 7 cases were followed for 2 years. The time for bone marrow mesenchymal stem cells could be available for clinical needs is as early as 5 days, not later than 10 days, and the median time is 8 days, while neural stem/progenitor cells in differentiated form can be available for clinical needs in as early as 12 days, not later than 15 days, and the median time is 13.5 days (statistical explanation: Case 5 only uses autologous mesenchymal stem cells, and Case 7 has two times bone marrow punctures). The neurological function of the patients was improved in 1-month follow-up, and the patients have a better discontinuous trend (statistical explanation: sometimes the neurological function of the patients between two adjacent follow-ups does not change significantly). After transplantation, four patients appeared to have transient fever, but it was easily controlled by symptomatic treatment. Seven patients did not appear to show secondary tumor induced by transplantation of stem cells in 2-year follow-up. Thus, it suggests that the use of autologous bone marrow-derived stem cells transplantation in patients with nervous system diseases is a feasible, convenient, safe, and effective method.

The analog of Ginkgo biloba extract 761 is a protective factor of cognitive impairment induced by chronic fluorosis.

Ginkgo biloba extract EGb761 is widely used to treat patients with learning and memory impairment in Alzheimer's disease and Parkinson's disease in China. However, it is not yet clear whether the analog of EGb761 (EGb) has a protective effect on the learning and memory damage induced by chronic fluorosis. In this study, 30 Wistar rats were randomly divided into three groups: a control group, a sodium fluoride (NaF) + EGb group, and a NaF group. The rats were administered 0.5 ml water containing NaF (100 mg/l) and EGb (120 mg/kg) per day via gavage. After 3 months, the rats' capacity for learning and memory was tested using a Y-maze. Damage to hippocampal neurons was evaluated by histological examination of the CA3 area. Superoxide dismutase (SOD) activity and the levels of glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured. Furthermore, the expression levels of Bcl-2 and Bax and the levels of cleaved Caspase3 in the hippocampus were evaluated by RT-PCR and Western blotting. The results showed that EGb could improve learning and memory abilities, enhance the activities of SOD and GSH-Px, attenuate the level of MDA, upregulate the ratio of Bcl-2/Bax, and downregulate the level of cleaved Caspase3.

The inhibition of ERK activation mediates the protection of necrostatin-1 on glutamate toxicity in HT-22 cells.

Receptor-interacting protein 1 (RIP1), a molecular switch protein from apoptosis to necroptosis, is regarded to play an essential role in necroptotic cell death. Although the increased RIP1 activity induced by tumor necrosis factor α activates mitogen-activated protein kinases (MAPKs) including ERK and leads to apoptotic or necrotic cell death, it is unclear what is the role of ERK during the process of necroptosis. In this study, our data demonstrated that ERK inhibitors U0126 and PD98059 blocked glutamate-induced necroptosis in HT-22 cells, indicating the critical role of ERK activation in necroptosis. Further, we found glutamate treatment increased phosphorylated ERK1/2 level, but the specific necroptosis inhibitor Necrostatin-1 (Nec-1) significantly inhibited the phosphorylation of ERK1 (P44) at 5, 10, and 15 min after glutamate treatment; the phosphorylation of ERK2 (P42) level was also markedly reduced by Nec-1 at 10 min after glutamate treatment. The phosphorylation of JNK and P38, two other MAPK members, were slightly increased after glutamate treatment, but Nec-1 had no inhibitory effect on JNK and P38 activation. Our finding suggested that ERK activation may play an important role in necroptotic cell death and the inhibition of ERK activation mediated the protection of Nec-1 on glutamate-induced necroptosis. Since ERK is considered as a downstream of RIP1, the RIP1/ERK signal pathway may provide new therapeutic avenues for the treatment of ischemia-reperfusion damage and neurodegenerative diseases-containing necroptotic cell death.