To investigate cytotoxic secondary metabolites of Micrococcus sp. R21, an actinomycete isolated from a deep-sea sediment (-6 310 m; 142 degrees 19. 9' E, 10 degrees 54. 6' N) of the Western Pacific Ocean, column chromatography was introduced over silica gel, ODS, and Sephadex LH-20. As a result, eight compounds were obtained. By mainly detailed analysis of the NMR data, their structures were elucidated as cyclo(4-hydroxy-L-Pro-L-leu) (1), cyclo(L-Pro-L-Gly) (2), cyclo( L-Pro-L-Ala) (3), cyclo( D-Pro-L-Leu) (4), N-β-acetyltryptamine (5), 2-hydroxybenzoic acid (6), and phenylacetic acid (7). Compound 1 exhibited weak cytotoxic activity against RAW264. 7 cells with IC50 value of 9.1 μmol x L(-1).
Animals ; Biological Factors ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Cell Survival ; drug effects ; Macrophages ; cytology ; drug effects ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Mice ; Micrococcus ; chemistry ; genetics ; isolation & purification ; metabolism ; Molecular Structure ; Phylogeny ; RAW 264.7 Cells ; Seawater ; microbiology ; Secondary Metabolism

OBJECTIVETo investigate the incidence and clinical features of mixed infections in children with Mycoplasma pneumoniae (MP) pneumonia.

METHODA total of 201 cases diagnosed as MP pneumonia were investigated for mixed infections by sputum bacterial culture, respiratory virus antigen detection and serum Chlamydia pneumoniae antibody test. For those with the indications for bronchoscopy, we also did bronchoalveolar lavage and lavage bacterial culture.

RESULTA high incidence (103/201, 51.2%) of mixed infections in children with MP pneumonia was revealed. The most frequent co-infected pathogen was Chlamydia pneumoniae (52, 25.9%), followed by viruses (29, 14.4%), and bacteria (22, 10.9%). Among viruses, respiratory syncytial virus was the most common (17, 8.5%), followed by adenovirus (6, 3.0%), parainfluenza virus type III (4, 2.0%) and influenza virus type B (2, 1.0%). Sputum bacterial culture was positive in 14/201 (7.0%) cases, Streptococcus pneumonia being most common (6, 3.0%). BALF culture yielded positive results in 11.6% (8/69), Streptococcus pneumonia was also common (5, 7.3%). Among 29 cases with MP and virus coinfection, 26 were younger than 3 years (89.7%), while for MP and Chlamydia pneumoniae coinfection, most of them were older than 3 years (40/52, 76.9%). Compared with non-mixed infections, those with mixed infections had longer fever duration (24.5% and 40.8% longer than 10 d), more frequently developed pleural effusion (11.2%, 23.3%) and large area of shadow in chest imaging (35.7%, 51.5%). White blood cell [(14.28 ± 4.99) × 10(9)/L], C-reactive protein (CRP) [69(32.5 - 99.5) mg/L] and neutrophil ratio in BALF [0.86 (0.63 - 0.91)] were much higher in children with mixed bacterial infections than that in non-mixed infections [(9.06 ± 3.47) × 10(9)/L, 3 (0 - 31.0) mg/L, 0.44 (0.03 - 0.88)]. But no significant difference was found in peripheral blood neutrophil proportion between mixed bacterial infections (0.38 ± 0.25) and non-mixed infections (0.51 ± 0.19).

CONCLUSIONMore than half of cases with MP pneumonia had mixed infections, most commonly caused by Chlamydia pneumonia followed by viruses. The incidence of mixed infections with bacteria was low. Mixed infections with virus were more common in young children, while mixed infection with Chlamydia pneumoniae was more common in older ones. Bacterial infections should be paid more attention, especially those caused by Streptococcus pneumoniae, for those with high peripheral white blood cell counts, high CRP levels and high proportion of neutrophils in BALF.

Adolescent ; Child ; Child, Preschool ; Chlamydophila pneumoniae ; isolation & purification ; Coinfection ; Female ; Humans ; Infant ; Inpatients ; Male ; Mycoplasma pneumoniae ; isolation & purification ; Pneumonia, Mycoplasma ; diagnosis ; microbiology ; virology ; Pneumonia, Viral ; diagnosis ; Respiratory Syncytial Viruses ; isolation & purification

Chronic hypoxic lung diseases are major causes of disability and mortality worldwide, which are typically aggravated by hypoxic pulmonary hypertension.The pathogenesis of hypoxic pulmonary hypertension is complex, and its mechanism has not been fully elucidated.The previous studies have shown abnormally elevated levels of free Ca + in the cytoplasm of pulmonary artery smooth muscle cells to be the predominant drivers of pulmonary hypertension , causing continuous contraction and remodeling of the pulmonary vessels.This article briefly summarizes the mechanism of hypoxia-induced imbalance in calcium homeostasis in pulmonary artery smooth muscle cells, together with its related drug research, based on the existing literature.Hypoxia induces an imbalance in calcium homeostasis in pulmonary artery smooth muscle cells by regulating hypoxia-inducible factor-1, K+ , store-operated calcium channel, receptor-operated calcium channel, the Ca +-sensing myosin contractile mechanism by binding to calmodulin, leading to pulmonary vasoconstriction.Ca + can also activate PKC/ MAPKs and PI3K/Akt/mTOR pathways, leading to pulmonary vascular remodeling.

OBJECTIVEMycoplasma pneumoniae (MP) is an important pathogen for community-acquired pneumonia in children. MP infection was considered to be self-limited, but many severe refractory MP pneumonia cases have been reported in recent years. The reason for variation in severity of MP pneumonia remains unclear. MP virulence including drug-resistance and host immunologic function are important influencing factors. The present study aimed to clarify relationship between local MP load and severity of MP pneumonia.

METHODMP DNA was quantitatively detected by fluorescent real-time PCR in bronchoalveolar lavage fluid (BALF) from 77 children with MP pneumonia. They were classified into groups of low MP load ( < 10(3)/ml, n = 14) , moderate MP load (10(3)-10(6)/ml, n = 22) and high MP load ( > 10(6)/ml, n = 41) . Clinical symptoms, main laboratory and imaging results of children among the three groups were compared.

RESULTWhen compared with low load group and moderate load group, high load group had longer fever duration (7 d, 10 d vs. 12 d) , longer time to normalization of temperature with macrolide administration (4 d, 8 d vs. 10 d) , more patients with high fever (50.0%, 68.2% vs. 87.8%) and longer duration of fever than 10 d (35.7%, 50.0% vs. 73.2%).Statistically significant difference existed in CRP among the three groups (1.0 mg/L, 11.5 mg/L, 34 mg/L). Large field of consolidation or atelectasis were found in 58.5% of high load patients, much higher than 22.7% in moderate load and 14.3% in low load patients. Bilateral or massive pleural effusion was not found in low load group, while in moderate load and high load group, they were 13.6% and 24.4%. However, no significant difference was found in symptoms and main laboratory and imaging results among different age groups in high load patients.

CONCLUSIONThere is a close relationship between MP load in BALF and clinical characteristics in children with MP pneumonia. Those with high MP load have a more severe process.

Adolescent ; Bacterial Load ; Bronchoalveolar Lavage Fluid ; microbiology ; Child ; Child, Preschool ; Colony Count, Microbial ; DNA, Bacterial ; genetics ; Female ; Humans ; Infant ; Male ; Mycoplasma pneumoniae ; genetics ; isolation & purification ; Pneumonia, Mycoplasma ; microbiology ; pathology ; Real-Time Polymerase Chain Reaction ; Severity of Illness Index

Objective To study biomechanical properties such as range of motion (ROM), intervertebral disc stress, ligament tension of inferior cervical spinal segment after the treatment of Discover, Prodisc-C artificial intervertebral disc replacement, and anterior cervical discectomy and fusion (ACDF), as well as mechanical property changes of the prosthesis after implantation. Methods Three kinds of operation plan on C5-6 cervical disc degeneration were established: Discover model, Prodisc-C model and ACDF model, as well as C4-7 segment original model of cervical vertebra. Biomechanical property changes after operation in cervical spine C4-7 segment in sagittal, coronal and transverse section were analyzed. Results ROM changes of cervical segment C5-C6 were as following: in Discover model it increased by 12.7%-73.1%, Prodisc-C model increased by 74%-98%, ACDF decreased by 55.8%-71.8%. The stress of C4-5 intervertebral disc after Discover artificial disc replacement showed no obvious increase, while the stress of C6-7 intervertebral disc decreased by 33.2%-54.2% under flexion, extension and axial rotation conditions. The amplification of ligament tension in Discover model decreased by 30%-40% as compared to that in Prodisc-C model. The maximum stress of Discover model (36.72 MPa) appeared under flexion condition, which was smaller than that in Prodisc-C model. Conclusions Artificial disc replacement can help to keep movement performance for segment after surgery. As a newly developed artificial intervertebral disc prosthesis, Discover makes some progress in the aspect of decreasing ligament stress and maintaining spinal stability. The research findings will provide theoretical basis for the clinical study on ACDF and artificial cervical intervertebral disc replacement surgeries.

OBJECTIVETo investigate the effect of premature rupture of the membrane (PROM) on neonatal complications in premature infants.

METHODSThe registration information of 7684 preterm infants with gestational age <37 weeks were collected from the cooperative units in the task group between January 1, 2014 to December 31, 2014. Specially trained personnel from each cooperative units filled in the unified form in a standardized format to record the gender, gestational age, birth weight, PROM, placental abruption, antenatal corticosteroid, Apgar score, amniotic fluid pollution, and complications of the infants. The data were analyzed comparatively between the cases with PROM and those without (control).

RESULTSThe preterm mortality rate was significantly lower but the incidences of ICH, NEC, ROP and BPD were significantly higher in PROM group than in the control group (P<0.05). The 95% confidence interval of the OR value was <1 for mortality, and was >1 for ICH, NEC, ROP and BPD. After adjustment for gestational age, birth weight, gender, mode of delivery, placental abruption, placenta previa, prenatal hormones, gestational diabetes mellitus (GDM), gestational period hypertension and 5-min Apgar score <7, the incidences of NEC, ROP and BPD were significantly different between the two groups (P<0.05) with 95% confidence interval of OR value >1, but the mortality rate and incidence of ICH were not significantly different between the two groups (P>0.05).

CONCLUSIONPROM is a risk factor for NEC, ROP and BPD in preterm infants, and adequate intervention of PROM can reduce the incidences of such complications as NEC, ROP and BPD in the infants.

Apgar Score ; Birth Weight ; Female ; Fetal Membranes, Premature Rupture ; pathology ; Gestational Age ; Humans ; Incidence ; Infant, Newborn ; Infant, Newborn, Diseases ; etiology ; Infant, Premature ; Pregnancy ; Risk Factors

The technology of lipid-drug conjugates is developed on the basis of prodrug principle, which overcomes some drawbacks of drugs via increasing the lipophilicity of hydrophilic or poorly soluble drugs to promote the absorption of drugs and enhance the curative effect. This article sums up the research progress of lipid-drug conjugates from the chemical synthesis methods of conjugates, the types of conjugates, the influence on biological activity of drugs, the application in nanoparticles for drug delivery and the mechanism of absorption and degradation.