Polymyxin B-functionalized phthalocyanine for chemo-photodynamic antibacterial therapy in enhanced wound healing

The rapid healing of bacteria-infected wounds was achieved via synergistic photodynamic antimicrobial therapy and chemotherapy using polymyxin B-functionalized phthalocyanine.

Contributions of Lactobacillus plantarum PC170 administration on the recovery of gut microbiota after short-term ceftriaxone exposure in mice

This study aimed to determine the impact of Lactobacillus plantarum PC170 concurrent with antibiotic treatment and/or during the recovery phase after antibiotic treatment on the body weight, faecal bacterial composition, short-chain fatty acids (SCFAs) concentration, and splenic cytokine mRNA expression of mice. Orally administrated ceftriaxone quantitatively and significantly decreased body weight, faecal total bacteria, Akkermansia muciniphila, and Lactobacillus plantarum, and faecal SCFAs concentration. Ceftriaxone treatment also dramatically altered the faecal microbiota with an increased Chao1 index, decreased species diversities and Bacteroidetes, and more Firmicutes and Proteobacteria. After ceftriaxone intervention, these changes all gradually started to recover. However, faecal microbiota diversities were still totally different from control by significantly increased α- and β-diversities. Bacteroidetes all flourished and became dominant during the recovery process. However, mice treated with PC170 both in parallel with and after ceftriaxone treatment encouraged more Bacteroidetes, Verrucomicrobia, and Actinobacteria, and the diversity by which to make faecal microbiota was very much closer to control. Furthermore, the expression of splenic pro-inflammatory cytokine tumour necrosis factor-α mRNA in mice supplemented with PC170 during the recovery phase was significantly lower than natural recovery. These results indicated that antibiotics, such as ceftriaxone, even with short-term intervention, could dramatically damage the structure of gut microbiota and their abilities to produce SCFAs with loss of body weight. Although such damages could be partly recovered with the cessation of antibiotics, the implication of antibiotics to gut microbiota might remain even after antibiotic treatment. The selected strain PC170 might be a potential probiotic because of its contributions in helping the host animal to remodel or stabilise its gut microbiome and enhancing the anti-inflammatory response as protection from the side effects of antibiotic therapy when it was administered in parallel with and after antibiotic treatment.

Incidence and Risk Factors of In-Stent Restenosis for Symptomatic Intracranial Atherosclerotic Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND

In-stent restenosis affects long-term outcome in patients with intracranial atherosclerotic stenosis.

PURPOSE

The aim of this meta-analysis was to evaluate the incidence and risk factors of in-stent restenosis.

DATA SOURCES

All literature that reported in-stent restenosis was searched on PubMed, Ovid EMBASE and Ovid MEDLINE data bases.

STUDY SELECTION

Original articles about stents for symptomatic intracranial atherosclerotic stenosis were selected.

DATA ANALYSIS

Meta-analysis was conducted to derive the pooled in-stent restenosis using a random-effects model. Meta-regression was performed to explore the risk factors predisposing to in-stent restenosis.

DATA SYNTHESIS

In total, 51 studies with 5043 patients were included. The pooled incidence rate of in-stent restenosis was 14.8% (95% CI, 11.9%-17.9%). Among the lesions with in-stent restenosis, 28.8% of them led to (95% CI, 22.0%-36.0%) related neurologic symptoms. The series in the United States had a higher in-stent restenosis rate (27.0%; 95% CI, 20.6%-33.9%) compared with those from Asia (13.6%; 95% CI, 10.3%-17.2%) and other regions as a whole (7.6%; 95% CI, 1.1%-18.1%) (P < .01). Multiregression analysis revealed that younger patient age was related to high in-stent restenosis rates (P = .019), and vertebrobasilar junction location (P = .010) and low residual stenosis (P = .018) were 2 independent risk factors for symptomatic in-stent restenosis rate.

LIMITATIONS

The heterogeneity of most outcomes was high.

CONCLUSIONS

Our study showed promising results of in-stent restenosis for symptomatic atherosclerotic stenosis. Studies are needed to further expatiate on the mechanisms by which younger patient age, vertebrobasilar junction location, and low residual stenosis could increase in-stent restenosis and symptomatic in-stent restenosis, respectively.

Landscape-level validation of allometric relationships for carbon stock estimation reveals bias driven by soil type

Mitigation of climate change depends on accurate estimation and mapping of terrestrial carbon stocks, particularly in carbon dense tropical forests. Allometric equations can be used to robustly estimate biomass of tropical trees, but often require tree height, which is frequently unknown. Researchers and practitioners must, therefore, decide whether to directly measure a subset of tree heights to develop diameter : height (D:H) equations or rely on previously published generic equations. To date, studies comparing the two approaches have been spatially restricted and/or not randomly allocated across the landscape of interest, making the implications of deciding whether or not to measure tree heights difficult to determine. To address this issue, we use inventory data from a systematic-random forest inventory across Gabon (102 forest sites; 42,627 trees, including 7,036 height-measured trees). Using plot-specific models of D:H as a benchmark, we compare the performance of a suite of locally fitted and commonly used generic models (parameterized national, georegional, and pantropical equations) across a variety of scales, and assess which abiotic, anthropogenic, and topographical covariates contribute the most to bias in height estimation. We reveal marked spatial structure in the magnitude and direction of bias in tree height estimation using all generic models, due at least in part to soil type, which compounded to substantial error in site-level AGB estimates (of up to 38% or 150 Mg/ha). However, two generic pantropical models (Chave 2014; Feldpausch 2012) converged to within 2.5% of mean AGB at the landscape scale. Our results suggest that some (not all) pantropical equations can extrapolate AGB across large spatial scales with minimal bias in estimated mean AGB. However, extreme caution must be taken when interpreting the AGB estimates from generic models at the site-level as they fail to capture substantial spatial variation in D:H relationships, which could lead to dramatic under- or over-estimation of site-level carbon stocks. Validated allometric models derived at site- or soil-type-levels may be the best way to reduce such biases arising from landscape-level heterogeneity in D:H model fit in the Afrotropics.

Effect of dual versus mono antiplatelet therapy on recurrent stroke modulated by activated partial thromboplastin time

BACKGROUND AND PURPOSE

The efficacy of dual antiplatelet treatment may be modified by many factors. The aim was to assess whether the effect of clopidogrel plus aspirin versus aspirin alone on recurrent stroke would be affected by admission activated partial thromboplastin time (aPTT).

METHODS

Data were derived from the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. A total of 5074 patients were categorized into three groups based on the aPTT distribution according to the 15th and 85th percentile. The primary outcome was any stroke within 90 days. The interaction of aPTT with antiplatelet therapy on stroke risk was assessed with a Cox proportional hazards model with adjustment for covariates.

RESULTS

In the high aPTT group (defined as ≥35.9 s), stroke occurred in 6.7% of patients in the clopidogrel-aspirin arm and 11.9% in the aspirin arm [adjusted hazard ratio (HR) 0.50; 95% confidence interval (CI) 0.29-0.85]. In the medium aPTT group (24.6-35.8 s), stroke occurred in 7.7% of patients in the clopidogrel-aspirin arm and 11.8% in the aspirin arm (adjusted HR 0.62; 95% CI 0.50-0.75). Furthermore, in the low aPTT group (≤24.5 s), stroke occurred in 11.2% of patients in the clopidogrel-aspirin arm and 9.9% in the aspirin arm (adjusted HR 1.07; 95% CI 0.65-1.62). The interaction P value of antiplatelet therapy with aPTT level at the cut-point of approximately 25 s or below was significant (P < 0.05).

CONCLUSIONS

Dual antiplatelet therapy was superior to single antiplatelet therapy in the high or medium aPTT group but not in the low aPTT group.

Effect of early dietary energy restriction and phosphorus level on subsequent growth performance, intestinal phosphate transport, and AMPK activity in young broilers

We aimed to determine the effect of low dietary energy on intestinal phosphate transport and the possible underlying mechanism to explain the long-term effects of early dietary energy restriction and non-phytate phosphorus (NPP). A 2 × 3 factorial experiment, consisting of 2 energy levels and 3 NPP levels, was conducted. Broiler growth performance, intestinal morphology in 0–21 days and 22–35 days, type IIb sodium-phosphate co-transporter (NaP_i-IIb) mRNA expression, adenylate purine concentrations in the duodenum, and phosphorylated adenosine monophosphate-activated protein kinase (AMPK-α) activity in 0–21 days were determined. The following results were obtained. (1) Low dietary energy (LE) induced a high feed conversion ratio (FCR) and significantly decreased body weight gain in young broilers, but LE induced significantly higher compensatory growth in low NPP (LP) groups than in the high or medium NPP groups (HP and MP). (2) LE decreased the villus height (VH) in the intestine, and LE-HP resulted in the lowest crypt depth (CD) and the highest VH:CD ratio in the initial phase. However, in the later period, the LE-LP group showed an increased VH:CD ratio and decreased CD in the intestine. (3) LE increased ATP synthesis and decreased AMP:ATP ratio in the duodenal mucosa of chickens in 0–21 days, and LP diet increased ATP synthesis and adenylate energy charges but decreased AMP production and AMP:ATP ratio. (4) LE led to weaker AMPK phosphorylation, higher mTOR phosphorylation, and higher NaP_i-IIb mRNA expression. Thus, LE and LP in the early growth phase had significant compensatory and interactive effect on later growth and intestinal development in broilers. The effect might be relevant to energy status that LE leads to weaker AMPK phosphorylation, causing a lower inhibitory action toward mTOR phosphorylation. This series of events stimulates NaP_i-IIb mRNA expression. Our findings provide a theoretical basis and a new perspective on intestinal phosphate transport regulation, with potential applications in broiler production.

Regulation of phosphate transport and AMPK signal pathway by lower dietary phosphorus of broilers

Lower available P (aP) was used as a base value in nutritional strategies for mitigating P pollution by animal excreta. We hypothesized that the mechanism regulating phosphate transport under low dietary P might be related with the AMPK signal pathway. A total of 144 one-day-old Arbor Acres Plus broilers were randomly allocated to control (HP) or trial (LP) diets, containing 0.45 and 0.23% aP, respectively. Growth performance, blood, intestinal, and renal samples were tested in 21-day-old broilers. Results shown that LP decreased body weight gain and feed intake. Higher serum Ca and fructose, but lower serum P and insulin were detected in LP-fed broilers. NaPi-IIb mRNA expression in intestine and NaPi-IIa mRNA expression in kidney were higher in the LP group. AMP: ATP, p-AMPK: total AMPK, and p-ACC: total ACC ratios in the duodenal mucosa were decreased in the LP group, whereas the p-mTOR: total mTOR ratio increased. These findings suggested that the increase in phosphate transport owing to LP diet might be regulated either directly by higher mTOR activity or indirectly by the suppressive AMPK signal, with corresponding changes in blood insulin and fructose content. A novel viewpoint on the regulatory mechanism underlying phosphate transport under low dietary P conditions was revealed, which might provide theoretical guidelines for reducing P pollution by means of nutritional regulation.

Effects of age on intestinal phosphate transport and biochemical values of broiler chickens

OBJECTIVE

The objective of this experiment was to characterize the mRNA expression profile of type IIb sodium-inorganic phosphate cotransporter (NaPi-IIb) and the biochemical values of serum alkaline phosphatase (AKP), calcium, inorganic phosphorus, tibial ash and minerals of broiler chickens with aging.

METHODS

A total of 56 one-day-old Arbor Acres male broiler chickens were used. Broiler chickens were weighed and samples were collected weekly from day 1.

RESULTS

The result showed that before the growth inflection point, ash, calcium, and phosphorus content in the tibia of broiler chickens increased with growth (before 3 weeks of age), although there were no significant differences in chicks at different ages in the later period of the experiment and weight gain rate was relatively slow at this stage (4 to 6 weeks). NaPi-IIb gene expression in the small intestine in the early growth stage was higher than that in the later growth stage. Expression of calbindin and the vitamin D receptor protein in the intestinal mucosa increased with age in the duodenum and jejunum. Serum AKP activity first increased and subsequently decreased after peaking at 1 week of age, but there was no significant difference after 3 weeks of age.

CONCLUSION

These results show that compared with the early growth stage, the weight-gain rate of broiler chickens in the late growth stage gradually decreased with gradual tibia maturation, along with weaker positive transport of phosphorus in the intestine and reinforced re-absorption of phosphorus in the kidney, which might be the reason that phosphorus requirement in the late growth stage was decreased.

Effect of Dietary Nutrient Density on Small Intestinal Phosphate Transport and Bone Mineralization of Broilers during the Growing Period

A 2 × 4 factorial experiment was conducted to determine the effects of dietary nutrient density on growth performance, small intestinal epithelial phosphate transporter expression, and bone mineralization of broiler chicks fed with diets with different nutrient densities and nonphytate phosphorus (NPP) levels. The broilers were fed with the same starter diets from 0 to 21 days of age. In the grower phase (day 22 to 42), the broilers were randomly divided into eight groups according to body weight. Relatively high dietary nutrient density (HDND) and low dietary nutrient density (LDND) diets were assigned metabolic energy (ME) values of 3,150 and 2,950 kcal/kg, respectively. Crude protein and essential amino acid levels were maintained in the same proportion as ME to prepare the two diet types. NPP levels were 0.25%, 0.30%, 0.35%, and 0.40% of the diets. Results showed that a HDND diet significantly increased the body weight gain (BWG) of broilers and significantly decreased the feed conversion ratio and NPP consumed per BWG. HDND significantly decreased tibial P content of the broilers. Conversely, mRNA expression of NaPi-IIb and protein expression of calbindin were significantly increased in the intestine of broilers fed a HDND diet. HDND also increased vitamin D receptor (VDR) expression, especially at a relatively low dietary NPP level (0.25%). The mRNA expression of NaPi-IIa in the kidneys was significantly increased at a relatively low dietary NPP level (0.25%) to maintain P balance. Tibial P, calcium, and ash content were significantly decreased, as were calbindin and VDR expression levels in the intestine at a low NPP level. Therefore, HDND improved the growth rate of broilers and increased the expression of phosphate and calcium transporter in the small intestine, but adversely affected bone mineralization.

Bioinformatics analysis of miRNA expression profile between primary and recurrent glioblastoma

OBJECTIVE

Glioblastoma (GBM) is the most malignant brain tumor with rapid relapse. The goal of this study is to identify microRNAs (miRNAs) involved in recurrent GBM.

MATERIALS AND METHODS

miRNA transcription profile data (GSE32466) were downloaded, including 12 primary GBM samples and 12 recurrent GBM samples. Then, limma package was utilized to identify differentially expressed miRNAs (DEMs) with the criteria of false discovery rate < 0.05 and |log2 fold change| ≥ 1. Thereafter, miTarget and TargetScan databases were used to predict the potential target genes of DEMs. Regulatory co-expression network was constructed based on co-expressed genes and potential miRNA-gene pairs, and then, pathway analysis was conducted. Furthermore, database miRWalk was used to screen out known GBM-associated miRNAs from the identified DEMs.

RESULTS

A total of 71 DEMs were identified between primary and recurrent GBM samples, and 2684 potential target genes were found. Besides, regulatory co-expression network was constructed, including 12 DEMs and 81 potential target genes. These genes significantly enriched in ECM-receptor interaction, ribosome, and focal adhesion pathways, and DEMs like hsa-miR-320a, hsa-miR-139-5p, has-miR-128, hsa-miR-140-5p, and hsa-miR-146b-5p had high degree. Notably, 7 DEMs in network were known GBM-associated miRNAs recorded in database miRWalk.

CONCLUSIONS

DEMs like hsa-miR-320a, hsa-miR-139-5p, has-miR-128, hsa-miR-146b-5p, hsa-let-7c, hsa-miR-128, and hsa-let-7a might participate in recurrent GBM. These results would pave ways for further study of recurrent GBM mechanism, and for the prevention and treatment of recurrent GBM. However, more experimental verifications are required to prove these predictions.

The inhibition of Cdk5 activity after hypoxia/ischemia injury reduces infarct size and promotes functional recovery in neonatal rats

Recent studies indicate that over-activation of Cdk5 is a crucial pro-death signal and Cdk5 activity inhibition provides neuroprotection in animal stroke models. However, Cdk5 inhibitors are reported to affect physiological functions of Cdk5 and lead to serious side effects. Therefore, targeting Cdk5 or its activators without affecting physiological functions of Cdk5 is a therapeutic strategy for ischemic brain injury. In this study, we examined Cdk5 activity in a rat hypoxia/ischemia (HI) injury model. Cdk5 expression was not changed after HI injury, but Cdk5 activity significantly increased, which was demonstrated by the increased phorsphorylation-phosphorylation of Tau and glucocorticoid receptor (GR), two downstream signals of Cdk5. We further showed that the levels of Cdk5 activators p35 and p39 decreased after HI injury, while p25, which is converted from p35 and has a higher activator activity on Cdk5, increased markedly after HI injury. P5, a 24-residue mimetic peptide of p35, was reported to specifically inhibit the p25/Cdk5 signal pathway in an Alzheimer's disease model. P5-TAT, which can cross the blood-brain barrier and cell membrane facilitated by TAT protein, was used in our study. We found that p5-TAT treatment did not change the levels of p35, p39, and p25, but reduced the phorsphorylation of Tau and GR, suggesting the inhibition of the p25/Cdk5 by the peptide p5-TAT. This was supported by the fact that p5 interacted with Cdk5, but not with Cdk5 activators. In addition, p5-TAT reduced cleaved caspase-3 level, a marker of neuronal apoptosis. We further demonstrated that p5-TAT pre-treatment reduced cerebral infarct volume; even when p5-TAT was delayed to be administered at 24h after HI injury, p5-TAT still promoted long-term functional recovery. Therefore, Cdk5 inhibition by the small peptide p5-TAT or its derivatives is a promising therapeutic strategy for the treatment of ischemic brain injury including hypoxic-ischemic encephalopathy and stroke.

CD29 of human umbilical cord mesenchymal stem cells is required for expansion of CD34(+) cells

OBJECTIVES

Human umbilical cord mesenchymal stem cells (hUCMSCs) play a critical role in expanding haematopoietic stem cells (HSCs) by providing the essential microenvironment for haematopoiesis. In this study, we sought to investigate whether CD29 of hUCMSCs would play a key role in the ability of hUCMSCs to help expand HSCs in vivo and in vitro.

MATERIAL AND METHODS

To investigate whether CD29 of hUCMSCs would play a key role for the ability of hUCMSCs to expand HSCs, soluble anti-CD29 antibody was added to co-cultures of hUCMSCs and cord blood (CB) CD34(+) cells. It significantly blocked expansion of CB CD34(+) cells induced by hUCMSCs. Using CD29-deficient hUCMSCs models, long-term culture-initiating cell and non-obese diabetic/severe combined immunodeficient disease mouse repopulating cell assay, revealed that CB CD34(+) cells co-cultured with CD29-deficient hUCMSCs only retained the capacity of multipotent differentiation for 5 weeks at the most.

RESULTS

Soluble anti-CD29 antibody significantly blocked expansion of CB CD34(+) cells induced by hUCMSCs. CB CD34(+) cells co-cultured with CD29-deficient hUCMSCs only retained the capacity of multipotent differentiation for 5 weeks at the most.

CONCLUSIONS

CB CD34(+) cells co-cultured with CD29-deficient hUCMSCs gave rise to all major haematopoietic lineages, but failed to engraft long term.