[Effects of bifidobacteria on respiratory and gastrointestinal tracts in neonates receiving mechanical ventilation].

OBJECTIVE: To study the effects of bifidobacterium on respiratory and gastrointestinal tracts in neonates receiving mechanical ventilation. METHODS: The eligible neonates were randomly assigned into two groups: observed (n=38) and control (n=43). The observed group was given bifidobacteria daily (one capsule per time, for 7 days) by nasal feeding from the next day after mechanical ventilation. Gastric pH, gastric bacteria colonization, feeding intolerance, weight gain, the incidence of ventilator-associated pneumonia (VAP), and the homology between the bacteria isolated from intra-gastric colonization with those causing VAP were observed. RESULTS: The incidence of gastric pH≤3 in the observed group was significantly higher than that in the control group 3, 5 and 7 days after mechanical ventilation (P<0.01). The rate of gastric bacteria colonization in the observed group was significantly lower than that in the control group 5 and 7 days after mechanical ventilation (P<0.01). The incidences of feeding intolerance and VAP in the observed group were significantly lower than those in the control group (P<0.05, P<0.01, respectively). The rate of homology of the bacteria isolated from intra-gastric colonization with those causing VAP in the observed group was significantly lower than that in the control group (P<0.01). There were no significant differences in the weight gain between the two groups. CONCLUSIONS: Bifidobacterium can decrease gastric pH, gastric bacteria colonization and feeding intolerance, thus blocks the infection route "stomach-oropharynx-respiratory tract" indirectly and decreases the incidence of endogenous VAP in neonates receiving mechanical ventilation.

Tumor-targeting peptide conjugated pH-responsive micelles as a potential drug carrier for cancer therapy.

Herein, we prepared tumor-targeting peptide (AP peptide; CRKRLDRN) conjugated pH-responsive polymeric micelles (pH-PMs) in cancer therapy by active and pH-responsive tumor targeting delivery systems, simultaneously. The active tumor targeting and tumoral pH-responsive polymeric micelles were prepared by mixing AP peptide conjugated PEG-poly(d,l-lactic acid) block copolymer (AP-PEG-PLA) into the pH-responsive micelles of methyl ether poly(ethylene glycol) (MPEG)-poly(beta-amino ester) (PAE) block copolymer (MPEG-PAE). These mixed amphiphilic block copolymers were self-assembled to form stable AP peptide-conjugated and pH-responsive AP-PEG-PLA/MPEG-PAE micelles (AP-pH-PMs) with an average size of 150 nm. The AP-pH-PMs containing 10 wt % of AP-PEG-PLA showed a sharp pH-dependent micellization/demicellization transition at the tumoral acid pH. Also, they presented the pH-dependent drug release profile at the acidic pH of 6.4. The fluorescence dye, TRITC, encapsulated AP-pH-PMs (TRITC-AP-pH-PMs) presented the higher tumor-specific targeting ability in vitro cancer cell culture system and in vivo tumor-bearing mice, compared to control pH-responsive micelles of MPEG-PAE. For the cancer therapy, the anticancer drug, doxorubicin (DOX), was efficiently encapsulated into the AP-pH-PMs (DOX-AP-pH-PMs) with a higher loading efficiency. DOX-AP-pH-PMs efficiently deliver anticancer drugs in MDA-MB231 human breast tumor-bearing mice, resulted in excellent anticancer therapeutic efficacy, compared to free DOX and DOX encapsulated MEG-PAE micelles, indicating the excellent tumor targeting ability of AP-pH-PMs. Therefore, these tumor-targeting peptide-conjugated and pH-responsive polymeric micelles have great potential application in cancer therapy.

Dark tea extracts: Chemical constituents and modulatory effect on gastrointestinal function.

Processing of dark tea varieties, such as Fu brick tea, Liupao tea, Qianliang tea, and Qing brick tea, includes solid-state fermentation involving microorganisms. In this study, we analyzed the major chemical constituents of dark tea extracts and evaluated their modulatory effect on the gastrointestinal function in normal mice, including the improvement of gastrointestinal transit and intestinal microbial, as well as the attenuation of intestinal microbial dysbiosis and intestinal pathological damage, and the adjustment of immune function in antibiotic-treated mice. Substantial differences in major chemical constituents, including total polyphenols, total organic acids, water extract content, 18 free amino acids, gallic acid, and six tea catechins, were observed among Fu brick tea, Qianliang tea, Qing brick tea, and Liupao tea extracts. Extracts from the four dark tea varieties significantly promoted gastrointestinal transit and colonization of beneficial Bifidobacterium and Lactobacillus, and inhibited the growth of harmful Escherichia coli and Enterococcus in normal mice. In addition, Qianliang tea, Qing brick tea, and Liupao tea extracts significantly accelerated the reversal of the ampicillin sodium-induced pathological damage in the ileum, intestinal bacterial dysbiosis (Bifidobacterium, Lactobacillus, E. coli, and Enterococcus), and low immunity.

Effect of combining different calcium concentration dialysate on calcium balance in peritoneal dialysis patients.

BACKGROUND: Calcium and phosphorus metabolic disturbance are common in dialysis patients and associated with increased morbidity and mortality. Therefore, maintaining the balance of calcium and phosphate metabolism and suitable intact parathyroid hormone (iPTH) level has become the focus of attention. We investigated the effects of different peritoneal dialysate calcium concentrations on calcium phosphate metabolism and iPTH in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: Forty stable CAPD patients with normal serum calcium were followed for six months of treatment with 1.25 mmol/L calcium dialysate (DCa1.25, PD4, 22 patients) or a combination of 1.75 mmol/L calcium dialysate (DCa1.75, PD2) and PD4 (18 patients) twice a day respectively. Total serum calcium (after albumin correction), serum phosphorus, iPTH, alkaline phosphatase (ALP) and blood pressure were recorded before and 1, 3 and 6 months after treatment commenced. RESULTS: No significant difference was found in baseline serum calcium, phosphorus between the two patient groups, but the levels of iPTH were significantly different. No significant changes were found in the dosage of calcium carbonate and active vitamin D during 6 months. In the PD4 group, serum calcium level at the 1st, 3rd, 6th months were significantly lower than the baseline (P < 0.05). There was no significant difference in serum phosphorus after 6 months treatment. iPTH was significantly higher (P < 0.001) at the 1st, 3rd, and 6th months compared with the baseline. No differences were seen in ALP and blood pressure. In the PD4+PD2 group, no significant changes in serum calcium, phosphorus, iPTH, ALP and BP during the 6-month follow-up period. CONCLUSIONS: Treatment with 1.25 mmol/L calcium dialysate for six months can decrease serum calcium, increase iPTH, without change in serum phosphorus, ALP, and BP. The combining of PD4 and PD2 can stabilize the serum calcium and avoid fluctuations in iPTH levels.