Inhibition mechanism of cordycepin and ergosterol from Cordyceps militaris Link. against xanthine oxidase and cyclooxygenase-2

Cordyceps militaris Link. (C. militaris) is an entomopathogenic fungus that parasitizes the pupa or cocoon of lepidopteran insect larvae, with various bioactive compounds. Cordycepin and ergosterol are the two active components in C. militaris. This study aimed to evaluate the inhibitory activity of cordycepin and ergosterol against xanthine oxidase (XO) and cyclooxygenase-2 (COX-2), as well as investigate the inhibition mechanism. Cordycepin could better inhibit XO (IC50 = 0.014 mg/mL) and COX-2 (IC50 = 0.055 mg/mL) than ergosterol. Additionally, surface hydrophobicity and circular dichroism (CD) spectra results confirmed the conformational changes in enzymes induced by cordycepin and ergosterol. Finally, cordycepin and ergosterol significantly decreased uric acid (UA) and inflammatory factors to normal level in mice with gouty nephropathy (GN). This study could provide theoretical evidence for utilization of C. militaris in hyperuricemia-management functional foods.

[Clinical efficacy and safety of vancomycin compared with linezolid for the treatment of neonatal gram-positive bacterial sepsis]

OBJECTIVE

To evaluate the clinical efficacy and safety of vancomycin and linezolid for the treatment of gram-positive neonatal bacterial sepsis.

METHOD

The data of neonates diagnosed as gram-positive bacterial sepsis in neonatology department of Suzhou Municipal Hospital from June 2009 to December 2015 were retrospectively collected. These neonates were divided into vancomycin group and linezolid group. Propensity score matching (PSM) on baseline variables was used to balance the two groups by identifying a comparable group of neonates who received vancomycin and linezolid therapy. Clinical and microbiologic success rates were compared by chi-square test, and changes of laboratory parameters before and after treatment at the end of treatment were then directly compared by rank-sum test between the matched groups. In vancomycin group, correlation between trough concentration of vancomycin and clinical efficacy were evaluated.

RESULT

Totally 108 and 209 cases were respectively selected in vancomycin and linezolid groups; 108 cases with well-matched baseline characteristics were included in matched linezolid group. The clinical success rates of vancomycin vs. linezolid therapy were 86.1%(93/108) and 88.9%(96/108)(P=0.681), and the microbiologic success rates were 91.7%(99/108) and 93.5%(101/108)(P=0.795). The average trough concentration of vancomycin was (12±8) mg/L. The rate of reaching the high trough concentration standard was only 33.3%(36/108). In 50 (46.3%) cases the dose was adjusted according to the initial concentration data. Compared to less than 10 mg/L, the clinical efficacy of trough concentration in 10-20 mg/L was much higher(93.9%(46/49) vs. 78.6%(33/42), P=0.031). Total bilirubin and platelet count had significant difference between the two-matched groups (34.1(14.9, 91.0)μmol/L vs. 53.0(27.0, 121.6)μmol/L, P=0.034; 301.0(198.8, 416.0)×10(9)/L vs. 195.5(94.0, 283.2)×10(9)/L, P=0.000). The incidence of linezolid related thrombocytopenia was 13.4%(28 cases).

CONCLUSION

The clinical effect of vancomycin and linezolid on gram-positive bacterial sepsis in neonates is comparable. The rate of trough concentration of vancomycin reaching the high trough concentration standard is low, and the clinical efficacy is related to trough concentration. Linezolid have an effect on bilirubin and platelet count, the risk of thrombocytopenia should be monitored closely during linezolid treatment.

Differential fadE28 expression associated with phenotypic virulence of Mycobacterium tuberculosis

Ability to persist in human macrophages is central to the virulence of Mycobacterium tuberculosis and is not invariable among various strains. Differential gene expression that is associated with phenotypic virulence may provide additional information of virulent genes involved in the pathogenesis of M. tuberculosis, which is not fully elucidated. Three hypervirulent strains of M. tuberculosis isolated from patients suffering with tuberculous meningitis were shown to grow more rapidly inside human macrophages in a previous study. In the current investigation, expression of 7 mycobacterial genes (fadE28, mce1A, mymA, acr, sigA, sugC, and Rv3723) of these strains during ex vivo macrophage challenge and in vitro acid shock was quantified by real-time PCR. Using rrs gene as a normalisation gene, fadE28 gene exhibited differential gene expression that is associated with phenotypic virulence, whereas the other 6 genes showed indistinguishable expression patterns. Up-regulation of fadE28 gene in the hypervirulent strains may account for virulence by increasing the efficiency of beta-oxidation, which is important for the persistence in macrophages as M. tuberculosis uses fatty acids preferably inside phagosome of macrophages. The fadE28 gene, together with its adjacent genes may also be critical in the process of lipid modification that could facilitate parasitism in human macrophages.

Molecular characterization of clinical isolates of Mycobacterium tuberculosis and their association with phenotypic virulence in human macrophages

Among 125 clinical isolates of Mycobacterium tuberculosis collected in Hong Kong and Shanghai, China, between 2002 and 2004, IS6110 typing revealed that 71 strains (57%) belonged to the Beijing family. The intracellular growth of the strains in human peripheral blood monocyte-derived macrophages was measured ex vivo on days 0, 3, 6, and 10. Among all tested strains, three hypervirulent strains showed significant increases in intracellular growth after 10 days of incubation. With an initial bacterial load of 10(4) CFU, most of the clinical isolates and H37Ra (an avirulent strain) exhibited no intracellular survival on day 10, while the three hypervirulent strains together with H37Rv (a virulent strain) showed on average a two- to fourfold rise in CFU count. These three hypervirulent strains belonging to a non-Beijing family were isolated from patients suffering from tuberculosis meningitis. Cytokines secreted by gamma interferon-activated macrophages were measured daily after challenge with selected strains of M. tuberculosis. The levels of tumor necrosis factor alpha were elevated after 24 h of infection among all strains, but the levels were significantly lower among the three hypervirulent strains, whereas interleukin 10 (IL-10) and IL-12 were not detected. Results were concordant with the differential expression of the corresponding cytokine genes in activated macrophages, as monitored by real-time PCR. Our findings highlighted that these three hypervirulent strains may possess an innate mechanism for escaping host immunity, which accounts for their characteristic virulence in patients presenting with a more severe form of disease.

Antibody response to four secretory proteins from Mycobacterium tuberculosis and their complex antigen in TB patients

OBJECTIVE

To evaluate antibody responses to a panel of four protein antigens secreted from Mycobacterium tuberculosis, CFP-21, ESAT-6, MPT-63 and MPT-64, and their complex antigen.

DESIGN

Seventy-eight samples of serum and cerebral spinal fluid were tested by ELISA.

RESULTS

Serum IgM antibody positive rates of protein antigens CFP-21, ESAT-6, MPT-63 and MPT-64 and their multi-antigen complex were respectively 34.6%, 60.3%, 52.6%, 78.2% and 96.2%; IgG antibody positive rates were respectively 46.2%, 64.1%, 93.6%, 57.7% and 84.6%. The specificity of the antibodies to the four proteins secreted from M. tuberculosis and its mixture antigen was 100%; sensitivity to the multi-antigen complex was higher than for the four single antigens. Among the IgM positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6, MPT-63 and MPT-64 were significant (P < 0.01); among the IgG positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6 and MPT-64 were significant (P < 0.01). Although the IgG positive rate for MPT-63 was higher than for the multi-antigen complex, the difference was not significantly different (P > 0.05).

CONCLUSION

These findings indicate that the multi-antigen complex composed of CFP-21, ESAT-6, MPT-63 and MPT-64 may be useful in the diagnosis of TB.

[Investigation of anti-Toxoplasma gondii antibodies in immunodeficient patients]

OBJECTIVE

To investigate the presence of anti-Taxoplasma gondii antibodies in immunodeficient patients.

METHODS

T. gondii-specific immunoglobulin G (IgG) antibodies in serum samples from 371 immunodeficient patients were detected by enzyme-linked immunosorbent assay (ELISA). The patients were with solid malignancies (including untreated digestive system malignancies and solid malignancies received chemotherapy), chronic liver diseases, patients received immunosuppressant therapy (dermatomyositis, psoriasis, pemphigus, post-renal transplantation, systemic lupus erythematosus and other miscellanies), lymphoma, leukemia and diabetes. 100 normal serum samples served as controls.

RESULTS

The positive rate of patients with solid malignancies received chemotherapy, solid malignancies received chemotherapy, chronic liver diseases, systemic lupus erythematosus and leukemia was 19.0%, 33.3%, 16.5%, 45.4% and 20.0%, respectively, being significantly higher than that of the control group(P < 0.05).

CONCLUSION

The immunosuppressed patients are highly predisposing to secondary T. gondii infection.

Chinese herbal formula XQ-9302: pilot study of its clinical and in vitro activity against human immunodeficiency virus

OBJECTIVES: To evaluate the effectiveness of XQ-9302--a purified, precise mixture of 20 Chinese herbs--against infection with human immunodeficiency virus in vitro and in the clinic. DESIGN: In vitro cell culture assay, heavy metal content analysis, and pilot non-randomised clinical trial. SETTING: Drug rehabilitation centre and municipal surveillance centre, Shanghai, China. PATIENTS: Forty-eight patients who had various clinical histories, such as drug abuse, cancer, and infection with human immunodeficiency virus, participated in the clinical study. INTERVENTION: During the clinical trial, multiple 15-day courses of XQ-9302 10.8 g/d were given to participants. MAIN OUTCOME MEASURES: CD4 count, P24 antigen level, level of antibody against human immunodeficiency virus, number of copies per millilitre of human immunodeficiency virus in the plasma (viral load), and any side effects. RESULTS: XQ-9302 protected cultured MT4 cells from infection with human immunodeficiency virus in vitro. Clinical tests showed that the herbal formula relieved the symptoms of acquired immunodeficiency syndrome and enhanced CD4 counts in patients infected by the human immunodeficiency virus. There were no observable side effects, even after taking the drug for several months. In three patients who had acquired immunodeficiency syndrome, treatment with XQ-9302 reduced the magnitude of the viral load by more than 1 log. CONCLUSION: XQ-9302 not only improves the immune function of patients infected with the human immunodeficiency virus, but also interrupts viral replication and slows the progression of the disease without detectable side effects. In addition, the heavy metal content of XQ-9302 is well within safety levels set by the Government of China.

[Extracellular ATP: effects, sources and fate]

The change of extracellular adenosine triphosphate (ATP) concentration affects many important physiological functions significantly. As a transmitter, ATP acts on neuro-effector junction directly and/or modulates the release of other neurotransmitters. By acting on the various P2-purinoceptors or ionic channels on the membrane, ATP also has some striking effects on cell activities. This review focused on the latest advances on the research of extracellular ATP in the respects of discovering and confirming ATP as a transmitter, the source, subtypes of P2-purinoceptors, the receptor-mediated reactions, and the degradation of extracellular ATP.

[Experimental study and case control study of nosocomial infection caused by Pseudomonas aeruginosa]

144 strains of Pseudomonas aeruginosa (Ps.a) were serotyped and phage-typed. Antibiotic sensitivity test and case control study of nosocomial infection caused by Ps.a were also done for these strains. Three epidemic strains were collected from the ICU in a neurosurgical ward. The etiology of a cross infection among tracheotomy patients was two epidemic strains isolated from the hands of a nurse and an attendant. Hospitalization days longer than 56 days, tracheotomy and indwelling catheterization were 3 risk factors for Ps.a infection shown by logistic analysis. The sensitivity rate of Ps.a to antibiotics was highest with ceftazidine, followed by amikacin and piperacillin. The most common resistant antibiogram was Gentamycin and tobramycin Resistance to gentamicin increased obviously.