Ammonium sulfate supplementation enhances erythromycin biosynthesis by augmenting intracellular metabolism and precursor supply in Saccharopolyspora erythraea.

In this study, the cellular metabolic mechanisms regarding ammonium sulfate supplementation on erythromycin production were investigated by employing targeted metabolomics and metabolic flux analysis. The results suggested that the addition of ammonium sulfate stimulates erythromycin biosynthesis. Targeted metabolomics analysis uncovered that the addition of ammonium sulfate during the late stage of fermentation resulted in an augmented intracellular amino acid metabolism pool, guaranteeing an ample supply of precursors for organic acids and coenzyme A-related compounds. Therefore, adequate precursors facilitated cellular maintenance and erythromycin biosynthesis. Subsequently, an optimal supplementation rate of 0.02 g/L/h was determined. The results exhibited that erythromycin titer (1311.1 µg/mL) and specific production rate (0.008 mmol/gDCW/h) were 101.3% and 41.0% higher than those of the process without ammonium sulfate supplementation, respectively. Moreover, the erythromycin A component proportion increased from 83.2% to 99.5%. Metabolic flux analysis revealed increased metabolic fluxes with the supplementation of three ammonium sulfate rates.

Responses of nitrogen and phosphorus resorption of understory plants to microscale soil nutrient hetero-geneity in Chinese fir plantation.

We compared the interspecific differences in leaf nutrient resorption of two dominant understory species (Lophatherum gracile and Oplimenus unulatifolius), and analyzed the correlations between the intraspecific efficiency of leaf nutrient resorption and nutrient properties of soil and leaves in Chinese fir plantation. The results showed high soil nutrient heterogeneity in Chinese fir plantation. Soil inorganic nitrogen content and available phosphorus content varied from 8.58 to 65.29 mg·kg-1 and from 2.43 to 15.20 mg·kg-1 in the Chinese fir plantation, respectively. The soil inorganic nitrogen content in O. undulatifolius community was 1.4 times higher than that in L. gra-cile community, but there was no significant difference in soil available phosphorus content between the two communities. Both leaf nitrogen and phosphorus resorption efficiency of O. unulatifolius was significantly lower than that of L. gracile under the three measurement bases of leaf dry weight, leaf area, and lignin content. Resorption efficiency in L. gracile community expressed on leaf dry weight was lower than that expressed on leaf area and lignin content, while resorption efficiency expressed on leaf area was the lowest in O. unulatifolius community. The intraspecific resorption efficiency was significantly correlated with leaf nutrient contents, but was less correlated with soil nutrient content, and only the nitrogen resorption efficiency of L. gracile had significant positive correlation with soil inorganic nitrogen content. The results indicated that there was significant difference in the leaf nutrient resorption efficiency between the two understory species. Soil nutrient heterogeneity exerted a weak effect on the intraspecific nutrient resorption, which might be attributed to high soil nutrient availability and potential disturbance from canopy litter in Chinese fir plantation.

A cyclic brush zwitterionic polymer based pH-responsive nanocarrier-mediated dual drug delivery system with lubrication maintenance for osteoarthritis treatment.

Enhanced joint synergistic lubrication combined with anti-inflammatory therapy is an effective strategy to delay the progression of early osteoarthritis (OA) but has been rarely reported. The hydration lubrication of zwitterions and inherent super-lubrication properties of the cyclic brush, as well as the enhancement of the steric stability of the cyclic topology, can effectively improve the drug loading and utilization; herein we report a pH-responsive cyclic brush zwitterionic polymer (CB) with SBMA and DMAEMA as brushes and a cyclic polymer (c-P(HEMA)) as the core template, possessing a low coefficient of friction (0.017). After loading with hydrophobic curcumin and hydrophilic loxoprofen sodium it demonstrates high drug-loading efficiency. In vitro and in vivo experiments confirmed the triple function of the CB on superlubrication, sequence controlled release and anti-inflammatory effects demonstrated by Micro CT, histological analysis and qRT-PCR. Overall, the CB is a promising long-acting lubricating therapeutic agent, with potential for OA treatment or other diseases.

Garlic-derived allyl sulfides in cancer therapy.

Garlic (Allium sativam L.) is widely used in traditional herbal remedies and alternative medicine. The potential health benefits of garlic are largely attributed to its metabolic byproducts. Extensive in vivo and in vitro studies has demonstrated that the garlic derivatives possess anti-cancer effects, but the underlying mechanisms are not completely understood. In this mini-review, we aim to summarize the reported biological effects of garlic products as anti-tumor agents, and present the possible molecular mechanisms responsible for the anti-carcinogenesis effects of garlic and its derivatives.

Effect of oviductus ranae and oviductus ranae eggs on bone metabolism and osteoporosis / 中国结合医学杂志

<p><b>OBJECTIVE</b>To evaluate the roles or effects of oviductus ranae (OR) or oviductus ranae eggs (ORE) in preventing and treating postmenopausal osteoporosis.</p><p><b>METHODS</b>In vivo experiment: Sixty female adult Wistar rats were randomly divided into 5 groups of 12. To provide an osteoporosis model 4 groups of rats were ovariectomized (OVX), with the 5th being sham operated. Medication commenced 7 days after the operation and lasted continuously for 12 weeks. Sham operated and OVX groups were given equivalent volumes of 5% Tween-80. The other three groups intragastrically received conjugated estrogens (CE), OR or ORE of the corresponding doses. At the 12th week, serum estrogen, bone gla protein (BGP), serum calcium, phosphorus, and alkaline phosphatase (ALP) were assayed; bone mineral densities (BMD) were measured and bone scanning was conducted; uteri were weighed, and weight, volume and length of the femoral bones were determined; and cortical thickness of femoral heads and area of bone trabecula were measured by image analyzer. In vitro experiment: Eighty 10-month old SD rats, with equal numbers of males and females, were randomly divided into 8 groups. Osteoblasts were isolated from neonatal rat calvariae, and the cells were exposed to various concentrations of serum from OR and ORE groups to study the impact of these sera on osteoblastic proliferation, ALP activity and mineralization. Osteoclastic numbers were determined using tartrate resistant acid phosphatase (TRAP).</p><p><b>RESULTS</b>In vivo experiment: The body weight of the four OVX groups increased significantly (P<0.01). Uterine weight of the CE group was the highest (P<0.01); Compared with the model group, estrogen level, BMD, bone scanning/bone imaging index weight of the femoral bones, cortical thickness of femoral heads in the OR and ORE groups increased significantly (P<0.05, P<0.01); femoral volume in the ORE group increased significantly (P<0.05); and the content of osteocalcin, phosphorus, and ALP in serum decreased significantly (P<0.05, P<0.01). In vitro experiment: Sera from OR and ORE groups had notable effects on the proliferation of osteoblasts (P<0.05 and P<0.01, repsectively) and stimulated the formation of calcium nodes (P<0.05, P<0.01), while the enhancement of ALP activity in osteoblasts was significant (P<0.05, P<0.01). The number of TRAP-positive cells was significantly reduced as well (P<0.01).</p><p><b>CONCLUSIONS</b>OR and its eggs could effectively suppress OVX-induced osteoporosis in rats, and increase bone turnover possibly by both an increase in osteoblastic activity and a decrease in osteoclastic activity. The present study provides evidence that OR and its eggs could be considered a complementary and alternative medicine for the treatment of postmenopausal osteoporosis.</p>

Therapeutic effects of endoscopic therapy combined with enteral nutrition on acute severe biliary pancreatitis.

BACKGROUND: Acute severe biliary pancreatitis (ASBP) is a severe and fatal disease, and the expenditure is huge and therapeutic effects are still not satisfactory. This study aimed to improve the therapeutic effects and reduce the expenditure of ASBP treatment. METHODS: One hundred and five patients diagnosed with ASBP were referred to our department from January 2004 to July 2009. Diagnosis was based on the 2007 criteria of the Chinese Society of Surgery. Patients were divided into two groups; the E group: 50 patients who underwent endoscopic retrograde choledochopancreatography (ERCP) + endoscopic sphincterotomy (EST) + endoscopic lithotripsy basket (ESR) + endoscopic retrograde biliary drainage (ERBD) and enteral nutrition (EN), and the R group: 55 patients who underwent traditional treatment without ERCP. Subsequently, subjective symptoms, signs, biochemical analysis, serum endotoxin, tumor necrosis factor a, grades by computed tomography (CT), cost of hospitalization and length of stay were compared between the two groups. RESULTS: All enrolled patients complied well with all therapeutic regimens. Endoscopic therapy that combined EN could significantly improve symptoms, clinical signs, laboratory values, tumor necrosis factor a and endotoxin while significantly reducing hospital expenditure and length of hospital stay. The experimental findings revealed that there were obvious advantages in the E group compared with the R group. CONCLUSIONS: Endoscopic therapy combined with EN is an effective, safe and economic therapeutic regimen of ASBP.

Therapeutic effects of endoscopic therapy combined with enteral nutrition on acute severe biliary pancreatitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acute severe biliary pancreatitis (ASBP) is a severe and fatal disease, and the expenditure is huge and therapeutic effects are still not satisfactory. This study aimed to improve the therapeutic effects and reduce the expenditure of ASBP treatment.</p><p><b>METHODS</b>One hundred and five patients diagnosed with ASBP were referred to our department from January 2004 to July 2009. Diagnosis was based on the 2007 criteria of the Chinese Society of Surgery. Patients were divided into two groups; the E group: 50 patients who underwent endoscopic retrograde choledochopancreatography (ERCP) + endoscopic sphincterotomy (EST) + endoscopic lithotripsy basket (ESR) + endoscopic retrograde biliary drainage (ERBD) and enteral nutrition (EN), and the R group: 55 patients who underwent traditional treatment without ERCP. Subsequently, subjective symptoms, signs, biochemical analysis, serum endotoxin, tumor necrosis factor a, grades by computed tomography (CT), cost of hospitalization and length of stay were compared between the two groups.</p><p><b>RESULTS</b>All enrolled patients complied well with all therapeutic regimens. Endoscopic therapy that combined EN could significantly improve symptoms, clinical signs, laboratory values, tumor necrosis factor a and endotoxin while significantly reducing hospital expenditure and length of hospital stay. The experimental findings revealed that there were obvious advantages in the E group compared with the R group.</p><p><b>CONCLUSIONS</b>Endoscopic therapy combined with EN is an effective, safe and economic therapeutic regimen of ASBP.</p>