No abstract

Azithromycin is a macrolide antibiotic used extensively in medicine for the treatment of a wide range of infections such as upper respiratory tract infections, middle ear infections, sexually transmitted infections and trachoma. It is also effective against the most common periodontopathogens. The versatility of the macrolides extends beyond their antibiotic properties as a result of their well-documented immune-modulating/anti-inflammatory effects. Macrolides, including azithromycin, are therefore used to treat diseases not associated with bacteria, such as severe asthma, chronic obstructive pulmonary diseases and, more recently, cystic fibrosis. Azithromycin is concentrated in neutrophils, macrophages and particularly fibroblasts; all of these cells are central players in the pathogenesis of most periodontal diseases. This paper reviews the diverse properties of azithromycin and the clinical periodontal studies of its effects in both the treatment of periodontitis and in resolving drug-related gingival overgrowth. Evidence exists to support the use of a single course of azithromycin in the treatment of advanced periodontal diseases. Azithromycin could have a triple role in the treatment and resolution of periodontal diseases: suppressing periodontopathogens, anti-inflammatory activity and healing through persistence at low levels in macrophages and fibroblasts in periodontal tissues, even after a single course of three tablets. If future periodontal research confirms these properties, it could become a valuable host-modulator in periodontal treatment.

Suboptimal temperature stress often causes heavy yield losses of vegetables by suppressing plant growth during winter and early spring. Gibberellin acid (GA) has been reported to be involved in plant growth and acquisition of mineral nutrients. However, no studies have evaluated the role of GA in the regulation of growth and nutrient acquisition by vegetables under conditions of suboptimal temperatures in greenhouse. Here, we investigated the roles of GA in the regulation of growth and nitrate acquisition of cucumber (Cucumis sativus L.) plants under conditions of short-term suboptimal root-zone temperatures (Tr). Exposure of cucumber seedlings to a Tr of 16°C led to a significant reduction in root growth, and this inhibitory effect was reversed by exogenous application of GA. Expression patterns of several genes encoding key enzymes in GA metabolism were altered by suboptimal Tr treatment, and endogenous GA concentrations in cucumber roots were significantly reduced by exposure of cucumber plants to 16°C Tr, suggesting that inhibition of root growth by suboptimal Tr may result from disruption of endogenous GA homeostasis. To further explore the mechanism underlying the GA-dependent cucumber growth under suboptimal Tr, we studied the effect of suboptimal Tr and GA on nitrate uptake, and found that exposure of cucumber seedlings to 16°C Tr led to a significant reduction in nitrate uptake rate, and exogenous application GA can alleviate the down-regulation by up regulating the expression of genes associated with nitrate uptake. Finally, we demonstrated that N accumulation in cucumber seedlings under suboptimal Tr conditions was improved by exogenous application of GA due probably to both enhanced root growth and nitrate absorption activity. These results indicate that a reduction in endogenous GA concentrations in roots due to down-regulation of GA biosynthesis at transcriptional level may be a key event to underpin the suboptimal Tr-induced inhibition of root growth and nitrate uptake. These findings may have important practical implications in effective mitigation of suboptimal temperature-induced vegetable loss under greenhouse conditions.

Emergent resistance to antibiotics among Streptococcus pneumoniae isolates is a severe problem worldwide. Antibiotic resistance profiles for S pneumoniae isolates identified from pediatric patients in mainland China remains to be established. The clinical features, antimicrobial resistance, and multidrug resistance patterns of S pneumoniae were retrospectively analyzed at 10 children's hospitals in mainland China in 2016. Among the collected 6132 S pneumoniae isolates, pneumococcal diseases mainly occurred in children younger than 5 years old (85.1%). The resistance rate of S pneumoniae to clindamycin, erythromycin, tetracycline, and trimethoprim/sulfamethoxazole was 95.8%, 95.2%, 93.6%, and 66.7%, respectively. The resistance rates of S pneumoniae to penicillin were 86.9% and 1.4% in non-meningitis and meningitis isolates, while the proportions of ceftriaxone resistance were 8.2% and 18.1%, respectively. Pneumococcal conjugate vaccine was administered to only 4.1% of patients. Penicillin and ceftriaxone resistance, underling diseases, antibiotic resistant risk factors, and poor prognosis appeared more frequently in invasive pneumococcal diseases. The incidence of multidrug resistance (MDR) was 46.1% in patients with invasive pneumococcal disease which was more than in patients with non-invasive pneumococcal disease (18.3%). Patients with invasive pneumococcal disease usually have several MDR coexistence. S pneumoniae isolates showed high resistance to common antibiotics in mainland China. Penicillin and ceftriaxone resistance rate of invasive streptococcal pneumonia patients were significantly higher than that of non-invasive S pneumoniae patients. Alarmingly, 46.1% of invasive clinical isolates were multidrug resistant, so it is important to continued monitor the resistance of S pneumoniae when protein conjugate vaccine (PCV13) is coming in mainland China.

In China, the responsibility of protecting the environment lies largely with local governments.Within the framework of spatial econometrics, we investigate empirically the consequence of such an institutional setting. Using city-level data for China, the present study finds that city governments behave strategically in making spending decisions regarding environmental protection. This paper finds that a city government appears to cut its own spending as a response to the rise in environmental protection spending by its neighbors. Hence, environmental protection tends to be underprovided. As a result, we suggest that centralizing the environmental protection responsibility to a higher level of government would be beneficial in terms of controlling pollution in China.