Bone marrow mesenchymal stem cell-derived exosomes attenuate D-GaIN/LPS-induced hepatocyte apoptosis by activating autophagy in vitro.

BACKGROUND: Acute liver failure is an inflammation-mediated hepatocyte injury. Mesenchymal stem cell (MSC) transplantation is currently considered to be an effective treatment strategy for acute liver failure. Exosomes are an important paracrine factor that can be used as a direct therapeutic agent. However, the use of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) in the treatment of acute liver failure has not been reported. PURPOSE: Here, we established a model of hepatocyte injury and apoptosis induced by D-galactosamine and lipopolysaccharide (D-GalN/LPS) to study the protective effect of BMSC-Exos on hepatocyte apoptosis, and further explored its protective mechanism. METHODS: BMSC-Exos was identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and Western blot. Laser confocal microscopy was used to observe the uptake of Dil-Exos by hepatocytes. D-GalN/LPS-induced primary hepatocytes were pretreated with BMSC-Exos in vitro, and then the cells were harvested. The apoptosis of hepatocytes was observed by TUNEL staining, flow cytometry and Western blot. Electron microscopy and mRFP-GFP-LC3 and Western blot was used to observe autophagy. RESULTS: BMSC-Exos increased the expression of autophagy marker proteins LC3 and Beclin-1 and promoted the formation of autophagosomes. After BMSC-Exos treatment, the expression levels of the proapoptotic proteins Bax and cleaved caspase-3 were significantly decreased, while the expression level of the anti-apoptotic protein Bcl-2 was upregulated. However, when the autophagy inhibitor 3MA was present, the effect of BMSC-Exos on inhibiting apoptosis was significantly reversed. CONCLUSIONS: Our results showed for the first time that BMSC-Exos had the potential to reduce hepatocyte apoptosis after acute liver failure. In particular, we found that BMSC-Exos attenuated hepatocyte apoptosis by promoting autophagy.

Disease severity and clinical outcomes of community-acquired pneumonia caused by non-influenza respiratory viruses in adults: a multicentre prospective registry study from the CAP-China Network.

Although broad knowledge of influenza viral pneumonia has been established, the significance of non-influenza respiratory viruses in community-acquired pneumonia (CAP) and their impact on clinical outcomes remains unclear, especially in the non-immunocompromised adult population.Hospitalised immunocompetent patients with CAP were prospectively recruited from 34 hospitals in mainland China. Respiratory viruses were detected by molecular methods. Comparisons were conducted between influenza and non-influenza viral infection groups.In total, 915 out of 2336 adult patients with viral infection were enrolled in the analysis, with influenza virus (28.4%) the most frequently detected virus, followed by respiratory syncytial virus (3.6%), adenovirus (3.3%), human coronavirus (3.0%), parainfluenza virus (2.2%), human rhinovirus (1.8%) and human metapneumovirus (1.5%). Non-influenza viral infections accounted for 27.4% of viral pneumonia. Consolidation was more frequently observed in patients with adenovirus infection. The occurrence of complications such as sepsis (40.1% versus 39.6%; p=0.890) and hypoxaemia (40.1% versus 37.2%; p=0.449) during hospitalisation in the influenza viral infection group did not differ from that of the non-influenza viral infection group. Compared with influenza virus infection, the multivariable adjusted odds ratios of CURB-65 (confusion, urea >7 mmol·L-1, respiratory rate ≥30 breaths·min-1, blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic), age ≥65 years) ≥3, arterial oxygen tension/inspiratory oxygen fraction <200 mmHg, and occurrence of sepsis and hypoxaemia for non-influenza respiratory virus infection were 0.87 (95% CI 0.26-2.84), 0.72 (95% CI 0.26-1.98), 1.00 (95% CI 0.63-1.58) and 1.05 (95% CI 0.66-1.65), respectively. The hazard ratio of 90-day mortality was 0.51 (95% CI 0.13-1.91).The high incidence of complications in non-influenza viral pneumonia and similar impact of non-influenza respiratory viruses relative to influenza virus on disease severity and outcomes suggest more attention should be given to CAP caused by non-influenza respiratory viruses.

A study of community-acquired Mycoplasma pneumoniae in Yantai, China / Estudio de Mycoplasma pneumoniae adquirido en la comunidad en Yantai, China

Abstract Introduction: Community-acquired pneumonia (CAP) is a global disease responsible for a large number of deaths, with significant economic impact. As diagnostic tools have increased in sensitivity, understanding of the etiology of CAP has begun to change. Mycoplasma pneumoniae is one of the major pathogens causing CAP. Macrolides and related antibiotics are first-line treatments for M. pneumoniae. Macrolide resistance has been spreading for 15 years and now occurs in worldwide. We undertook the first study on macrolide resistance of M. pneumoniae in Yantai. This may be helpful to determine the appropriate therapy for CAP in this population. Objective: To investigate the rate and mechanism of macrolide resistance in Yantai. Methods: Pharyngeal swab samples were collected from adult CAP patients. Samples were assayed by polymerase chain reaction (PCR) and cultivated to test for M. pneumoniae. Nested PCR was used to specifically amplify M. pneumoniae 23S rRNA gene fragments containing mutations, and amplicons were analyzed by CE-SSCP for macrolide resistance mutations. Results were confirmed by sequencing. Twenty-seven strains of M. pneumoniae were isolated and the activities of nine antibiotics against M. pneumoniae were tested in vitro. Results: Out of 128 samples tested, 27 were positive for M. pneumoniae. Mycoplasma 100% macrolides resistance to Mycoplasma pneumoniae. The mechanism of macrolides resistance was A2063G point mutation in the sequence directly binding to macrolides in the 23S rRNA V domain in vitro. The mean pyretolytic time for the fluoroquinolone group was 4.7 ±2.9 d, which was significantly shorter than 8.2 ±4.1 d for the azithromycin group. Conclusions: Macrolides are not the first-line treatment for M. pneumoniae respiratory tract infections in Yantai.

Resumen Introducción: Neumonía adquirida por en la comunidad (NAC) es una enfermedad responsable por un gran número de muertes y un impacto económico importante. Debido a que el diagnostico incrementó la sensibilidad, se cambió la etiología de la NAC. Adicionalmente, Mycoplasma pneumoniae es uno de los patógenos que causan la NAC. Los macrólidos y antibióticos relacionados son la primera línea de tratamiento para M. pneumoniae. La resistencia a macrólidos se aumentó en los últimos 15 años y ahora se encuentra distribuido en todo el mundo. Nosotros realizamos el primer estudio de resitencia a M. pneumoniae a los macrólidos en Yantai. Esto podría ser útil para determinar una terapia apropiada para NAC en esta población. Objetivo: Investigar la tasa y el mecanismo para la resitencia a los macrólidos en Yantai. Métodos: Se colectaron muestras faringeas usando un hisopo. Las muestras se analizaron mediante la reacción en cadena de la polimerasa (PCR) y por cultivo para M. pneumoniae. Se uso una PCR anidad para amplificar fragmentos del gen 23S rRNA especifico con las mutaciones para M. pneumoniae. Se analizaron amplicomes por CE-SSCP para determinar la resitencia a los macrólidos. Estos resultados se confirmaron por secuenciación. Se aislaron 27 cepas de M. pneumoniae y se probaron nueve antibióticos in vitro. Resultados: De 128 muestras, 27 fueron positivas para M. pneumoniae. Se determinó una resistencia a macrólidos por Mycoplasma del 100%. Los mecanismos de esta resitencia fue una mutacion punctual A2063G en la secuencia que se une directamente a los macrólidos en el dominio 23S rRNA V in vitro. El tiempo piotolítico medio para el grupo de fluoroquinolonas fue 4.7 ±2.9 d, que fue significativamente más corto que para el grupo de azitromicina: 8.2 ±4.1 d. Conclusiones: Los macrólidos no son la primera linea de tratamiento para las infecciones del tracto respiratorio contra M. pneumoniae respiratory tract infections en Yantai.

Microbiological and clinical data analysis of 32 patients with Nocardia infections in Yantai

Background/aim: Nocardia is an opportunistic pathogen that mostly affects hosts with immune deficiencies. Recently, the widespread use of immunosuppressive agents and antitumor drugs has led to an increasing number of Nocardia infections being reported. However, it is difficult to confirm this diagnosis owing to the slow growth of the bacterium and its complex resultant clinical manifestations, potentially delaying treatment and increasing mortality. Thus, further knowledge on the clinical characteristics of Nocardia infection is required. Hence, this study aimed to review the demographics, comorbidities, clinical presentation, microbiology, treatment, and outcomes of Nocardia infections in Yantai. Materials and methods: This is a retrospective study including 32 patients identified to have Nocardia infection from the Yantai Yuhuangding Hospital. The relevant patient samples were collected by two researchers, while the other researchers analyzed the relevant data. Results: The male to female ratio among the 32 patients was 3:5, and 23 patients (71.9%) were immunocompromised. Pulmonary sites of infection were the most common (65.6% of patients). N. brasiliensis infections were present in 25.0% and N. asteroides infections were present in 21.9% of patients. Because of limited biotechnological resources, Nocardia spp. in 50.0% of cases were not classified. The TMP-SMX resistance rate among isolates was 9.4%. All isolates were susceptible to amikacin, ceftriaxone, and imipenem. Conclusion: In Yantai, immunocompromised patients predominate among cases of Nocardia infection. The rate of occurrence was higher in females than in males. Because of potential TMP-SMX resistance, treatment for Nocardia infection should be based on drug susceptibility or should include combination therapy.

Viral etiology of community-acquired pneumonia among adolescents and adults with mild or moderate severity and its relation to age and severity.

BACKGROUND: Better knowledge of distribution of respiratory viruses (RVs) in adolescents and adults with community-acquired pneumonia (CAP) is needed. METHODS: To investigate the RVs etiology among adolescents and adults with CAP, according to age and pneumonia severity index (PSI), a multi-center, prospective study was conducted from November 2010 to April 2012. Fifteen RVs were tested by polymerase chain reaction (PCR). Bacteria were detected by urinary antigen, conventional culture and PCR. RESULTS: Mean (SD) age and median (IQR) PSI score of 954 patients enrolled was 45.2 (19.5) years (range 14-94) and 42 (36). RVs were found in 262 patients (27.5%): influenza virus A (IFV A, 9.9%) comprised of pandemic H1N1 (6.7%) and seasonal H3N2 (3.5%), human rhinovirus (4.3%), adenovirus (4.2%), human metapneumovirus (1.8%), parainfluenza virus 1, 3 and 2 (1.7%, 1.5% and 1.2%). Influenza virus B, enterovirus, respiratory syncytial virus, human coronavirus and parainfluenza virus 4 were rarely detected (<1%). Frequency of IFV A was highest among patients aged between 45-64 years (p < 0.001), while adenovirus among patients aged 14-17 years (p < 0.001), no differences was found in other RVs. The proportion of pandemic H1N1 increased with severity of pneumonia evaluated by PSI (P < 0.05). CONCLUSIONS: The proportion of RVs in CAP is higher than previously reported. IFV A pneumonia are usually found in patients older than 45 years, while, adenovirus pneumonia are common in adolescents and young adults. Pandemic H1N1 virus is still recognized by PSI as a high-severity pathogen. The findings contribute baseline data on viral CAP study in China.

Clinical data analysis of 19 cases of community-acquired adenovirus pneumonia in immunocompetent adults.

The aim of this study was to investigate the characteristics of clinical manifestations, laboratory tests and imaging changes of community-acquired adenovirus pneumonia in immunocompetent adults. A retrospective study was performed on 19 adult community-acquired adenovirus pneumonia cases in Yantai, whereby the clinical data were collected and analyzed. Of 19 cases, 14 (73.68%) had fever and 17 (89.47%) had cough symptoms. Moreover, 14 cases (73.68%) had normal white blood cell counts, while 11 cases (57.89%) exhibited a reduction in lymphocyte proportion. Among the 19 cases, 17 cases exhibited lesions in a single lung, while 2 cases involved bilateral lungs. The lesions predominantly exhibited ground glass-like changes. The clinical manifestations of adult community-acquired adenovirus pneumonia patients with normal immune functions were mild, with such presenting symptoms as fever, cough, and sputum; most patients did not exhibit high levels of white blood cells or low lymphocyte counts, and the imaging features (ground glass-like effusion) were indicative of single-lung involvement.

Emergence of community-acquired adenovirus type 55 as a cause of community-onset pneumonia.

BACKGROUND: Since 2008, severe cases of emerging human adenovirus (HAdV) type 55 (HAdV-55) were reported sporadically in China. But no comparative studies had been conducted to discern the differences in epidemiologic and clinical abnormalities between HAdV-55 and other types (HAdV-7, HAdV-3, HAdV-14, HAdV-50, and HAdV-C). METHODS: A multicenter surveillance study for adult and adolescent community-acquired pneumonia (CAP) was conducted prospectively in Beijing and Yan Tai between November 2010 and April 2012. A standardized data form was used to record clinical information. The viral DNA extracted from the clinical samples or adenovirus viral isolates was sequenced. RESULTS: Among 969 cases, 48 (5%) were identified as adenovirus pneumonia. Six branches were clustered: HAdV-55 in 21, HAdV-7 in 11, HAdV-3 in nine, HAdV-14 in four, HAdV-50 in two, and HAdV-C in one. Most HAdV-55 cases were identified during February and March. All the hypervariable regions of the hexon genes of the 21 HAdV-55 strains were completely identical. Patients who had HAdV-55 were about 10 years older ( P = .027) and had higher pneumonia severity index scores ( P = .030) compared with those with other types (HAdV-7, HAdV-3, HAdV-14, HAdV-50, and HAdV-C). Systemic BP was also higher among patients in the HAdV-55 group ( P = .006). Unilateral or bilateral consolidations were the most common radiologic findings in both patients with HAdV-55 and those with other types (57.9% vs 36%). More than one-half of the patients were admitted to hospital; oxygen therapy was given to 29.2% of the 48 patients, and two needed mechanical ventilation. CONCLUSIONS: HAdV-55 has established itself as a major pneumonia pathogen in the Chinese population, and further surveillance and monitoring of this agent as a cause of CAP is warranted.