Stability and compatibility of doxofylline with phentolamine mesilate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion

WHAT IS KNOWN AND OBJECTIVE

The use of extemporaneously prepared admixtures of drugs must be supported by documentation of their chemical stability. The objective was to assess the physical compatibility and the chemical stability of doxofylline with phentolamine mesilate in 0.9% sodium chloride or 5% dextrose injection for intravenous infusion.

METHODS

Total volumes of 20 and 1 mL of doxofylline solution and phentolamine mesilate solution, respectively, were added to 250 mL polyolefin bags containing 5% dextrose injection or 0.9% sodium chloride injection. Bags were stored for 24 h at 20-25 °C. Chemical compatibility was measures with high-performance liquid chromatography, and physical compatibility was determined visually.

RESULTS

The samples were clear and colourless when viewed in normal fluorescent room light. The pH value and particulate content of the admixtures exhibited little change. The retentions of the initial concentration of doxofylline and phentolamine mesilate in the admixtures were within 97-105%. Doxofylline and phentolamine mesilate were stable in 5% dextrose injection or in 0.9% sodium chloride for up to 24 h at 20-25 °C.

WHAT IS NEW AND CONCLUSION

Doxofylline and phentolamine mesilate mixed in both 5% dextrose injection and 0.9% sodium chloride injection in 250 mL multilayer polyolefin bags at concentrations of 0.74 mg/mL and 36.9 μg/mL, respectively, were stable for up to 24 h at 20-25 °C.

Identification of nitrogen-fixing Paenibacillus from different plant rhizospheres and a novel nifH gene detected in the P. stellifer

A total of 534 isolates were selectively obtained from different plant rhizospheres based on their growth on nitrogen-free medium and their resistance to 80 degrees C for 15 min. Of the 534 isolates, 23 isolates had nifH gene and exhibited nitrogenase activities. Based on 16S rDNA sequence, G + C content assay and DNA-DNA hybridization, by the 23 isolates, which were divided into four monophyletic clusters, all belonged to the Paenibacillus genus. NifH gene deduced amino acid alignment analysis revealed that cluster I, including 15 isolates, showed the highest NifH identity with Paenibacillus genus; while cluster II identified as P stellifer by DNA-DNA hybridization was consistent with four uncultured bacterial clones. This study suggested that the nitrogen-fixing Paenibacillus were distributed in various ecosystems and prevalent in different plant rhizospheres. It was the first demonstration that nitrogen fixation existed in P. jamilae and P. stellifer. In eight isolates identified as P. stellfer species, a novel nifH gene was detected in Paenibacillus.

Strain improvement for enhanced production of cellulase in Trichoderma viride

The filamentous fungi Trichoderma species produce extracellular cellulase. The current study was carried out to obtain an industrial strain with hyperproduction of cellulase. The wild-type strain, Trichoderma viride TL-124, was subjected to successive mutagenic treatments with UV irradiation, low-energy ion beam implantation, atmospheric pressure non-equilibrium discharge plasma (APNEDP), and N-methyl-N'-nitro-N-nitrosoguanidine to generate about 3000 mutants. Among these mutants, T. viride N879 strain exhibited the greatest relevant activity: 2.38-fold filter paper activity and 2.61-fold carboxymethyl cellulase, 2.18-fold beta-glucosidase, and 2.27-fold cellobiohydrolase activities, compared with the respective wild-type activities, under solid-state fermentation using the inexpensive raw material wheat straw as a substrate. This work represents the first application of APNEDP in eukaryotic microorganisms.

Directional differentiation of chicken primordial germ cells into adipocytes, neuron-like cells, and osteoblasts

Primordial germ cells (PGCs) are useful for producing transgenic chickens and preserving genetic material in avian species. In this study, we investigated the in vitro differentiation potential of chicken PGCs into different cell types. For differentiation into adipocytes, chicken PGCs were cultured for 21 days in induction media containing dexamethasone, insulin and/or 3-isobutyl-1-methylxanthine (IBMX), and differentiation rates ranging from 74% to 91% were identified by oil red-O and alkaline phosphatase (ALP) staining. For differentiation into neuron-like cells, chicken PGCs were cultured for 3 or 7 days in the induction media containing retinoic acid (RA) and IBMX, and differentiation rates ranging from 71% to 87% were identified by toluidine blue staining and immunohistochemical staining. For differentiation into osteoblasts, chicken PGCs were cultured for 15 or 21 days in the induction media containing desamethasone, beta-glycerol phosphate and/or vitamin C, and differentiation rates ranging from 47% to 79% were confirmed by Von Kossa, cytochemical and immunohistochemical staining. These data suggest that, like mammalian PGCs, chicken PGCs can differentiate into different cell types in vitro.

Clinicopathological implications of tumour-associated macrophages and vascularization in sinonasal melanoma

This study investigated tumour-associated macrophages (TAMs) and their effects on tumour vascularization in sinonasal melanoma (SNM). Data on 45 patients with SNM undergoing surgery were reviewed retrospectively. Tumour sections were analysed immunohistochemically for TAMs, microvessels, lymph vessels, and vasculogenic mimicry in both intra- and peritumoural areas. The density of intratumoural TAMs was associated with tumour thickness and with overall survival in SNM stages I and II but there were no correlations between micro- or lymph vessel density and TAM infiltration. Greater TAM infiltration was observed in tumour tissues with vasculogenic mimicry although this was not statistically significant. These data suggest that high intratumoural TAM infiltration is associated with tumour aggressiveness and a poor prognosis for SNM, and that activation of macrophages can be polarized by different micro-environments. TAMs could be potential prognostic indicators for patients with SNM.

Meta-analysis of epidemiological studies of association of P53 codon 72 polymorphism with bladder cancer

Although there have been many studies investigating a possible association between p53 codon 72 polymorphism and risk of bladder cancer, the results have been inconsistent. We conducted a meta-analysis of six epidemiological studies, which included 597 bladder cancer cases and 731 controls. Patients with bladder cancer had a significantly lower frequency of Pro/Arg [odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.64-0.99], when compared to controls. Stratifying for race, we found that among Caucasians, patients with bladder cancer had a significantly higher frequency of Arg/Arg (OR = 1.64, 95%CI = 1.18-2.28) and a lower frequency of Pro/Arg (OR = 0.62, 95%CI = 0.44-0.86), compared to controls. Stratifying various studies by the stage of bladder cancer, we found that invasive bladder cancers had a significantly lower frequency of Arg/Arg (OR = 0.58, 95%CI = 0.36-0.93) and a higher frequency of Pro/Arg (OR = 0.62, 95%CI = 0.44-0.86) than did non-invasive bladder cancers. No significant association was found between this genotype and human papilloma virus. Based on our meta-analysis, we suggest that p53 codon 72 polymorphism is associated with bladder cancer and that genotypic distribution of this polymorphism varies with the stage of bladder cancer.

Molecular cloning of the duck MyoG and MRF4 genes coding region sequence and their differential expression patterns in the breast and leg muscle during fetal development

The MyoG and MRF4 genes encode for transcription factors that play key roles in muscle formation during embryonic and fetal development. Due to the unique functions of these two genes, they have a specific expression pattern in the same muscle tissues. In order to investigate the different developmental expression patterns of the two genes, the coding region sequences of duck MyoG and MRF4 were cloned and their mRNA expression patterns in the duck breast and leg muscles were measured using real-time quantitative polymerase chain reaction (qPCR). The duck MyoG and MRF4 both have a basic helix-loop-helix (bHLH) domain with high homology to several other species. In addition, there is a low homology region at the carboxy-terminus of these two proteins. The mRNA expression of MyoG reaches a peak at embryonic day 14 (E14d) in both the breast muscle and the leg muscle of duck. The peak mRNA expression of MRF4 appears at E14d in the breast muscle and at E18d in the leg muscle. The expression patterns of MyoG and MRF4 were different between the breast muscle and the leg muscle of duck. In the fetal duck, the leg muscle develops earlier than the breast muscle, which may better accommodate the newborn duck to a new environment postnatally.Key words: Duck, MyoG and MRF4, expression pattern, fetal development

Incidence, management and mortality of acute hypoxemic respiratory failure and acute respiratory distress syndrome from a prospective study of Chinese paediatric intensive care network

AIM

To investigate the incidence, clinical management, mortality and its risk factors, major outcome and costs of acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) in a Chinese network of 26 paediatric intensive care unit (PICU).

METHODS

In a consecutive 12-month period, AHRF and ARDS were identified and followed up for 90 days or until death or discharge.

RESULTS

From a total of 11 521 critically ill patients, 461 AHRF were identified in which 306 developed ARDS (66.4%), resulting in incidences of 4% and 2.7%, respectively, with pneumonia (75.1%) and sepsis (14.7%) as main underlying diseases and 83% were 5 years and 1 month-old. In-hospital mortality of AHRF was 41.6% (44.8% for ARDS), accounted for 15.5% of all PICU deaths. For those of pneumonia or sepsis with AHRF and ARDS, mortality and its relative risk were significantly higher than those without. Relatively lower tidal volume and total fluid balance, adequate upper limit of PaCO(2) in the early PICU days, and family affordability, tended to result in better outcome.

CONCLUSION

In this prospective study, AHRF had high possibilities to develop ARDS and death risk, as impacted by ventilation settings and fluid intake in the early treatment, as well as socioeconomic factors, which should be considered for implementation of standard of care in respiratory therapy.

Substrate specificity of family 5, 6, 7, 9, 12, and 45 endoglucanases

Endoglucanases are important enzymes for biomass conversion and other industrial processes. Determining the specificity of endoglucanases from various glycoside hydrolase families is of interest for bioinformatic functional prediction and substrate-tailored enzyme development. To do so, we characterized approximately 30 endoglucanases from six glycoside hydrolase families. For p-nitrophenyl cellobioside and lactoside, only family 7 enzymes showed significant activity. For xyloglucan, both family 7 and 12 enzymes showed significant activity. For xylan and arabinoxylan, only family 7 enzymes showed significant activity. For mannan and galactomannan, both family 5 and 9 enzymes showed significant activity. The difference in specificity was preliminarily attributed mainly to the structural difference of the enzymes' active sites. For family 7 endoglucanases, difference in thermal stability might affect their performance in hydrolyzing various (hemi)cellulose substrates. Phylogenetic analysis on the subfamily distribution of family 5 endoglucanases (in relation with mannanases) suggested that their mannanase side-activity might be the remnant of an ancestral multi-function enzyme. Similar analysis was also made with the xyloglucanase or arabionxylans side-activity of family 12 and 7 endoglucanases. The apparent dependence of the specificity on family (primary/tertiary structure) might assist us in better understanding the structure-function relationship of the enzymes, and developing more versatile biocatalysts for the utilization of biomass.

A droplet-based building block approach for bladder smooth muscle cell (SMC) proliferation

Tissue engineering based on building blocks is an emerging method to fabricate 3D tissue constructs. This method requires depositing and assembling building blocks (cell-laden microgels) at high throughput. The current technologies (e.g., molding and photolithography) to fabricate microgels have throughput challenges and provide limited control over building block properties (e.g., cell density). The cell-encapsulating droplet generation technique has potential to address these challenges. In this study, we monitored individual building blocks for viability, proliferation and cell density. The results showed that (i) SMCs can be encapsulated in collagen droplets with high viability (>94.2 +/- 3.2%) for four cases of initial number of cells per building block (i.e. 7 +/- 2, 16 +/- 2, 26 +/- 3 and 37 +/- 3 cells/building block). (ii) Encapsulated SMCs can proliferate in building blocks at rates that are consistent (1.49 +/- 0.29) across all four cases, compared to that of the controls. (iii) By assembling these building blocks, we created an SMC patch (5 mm x 5 mm x 20 microm), which was cultured for 51 days forming a 3D tissue-like construct. The histology of the cultured patch was compared to that of a native rat bladder. These results indicate the potential of creating 3D tissue models at high throughput in vitro using building blocks.

Dynamics of microRNA-mediated motifs

In the past, most research on gene regulation has focused on transcriptional regulation and post-translational regulation. Recently, the post-transcriptional regulation by small non-coding RNAs has drawn much attention. This mode of regulation was found in both prokaryotes and eukaryotes. In this study, the authors integrate transcriptional and post-transcriptional regulation into four different kinds of microRNA-mediated motifs and investigate the mechanism of microRNAs regulation from the viewpoints of dynamics. Theoretical analysis and numerical simulations show that all the four motifs exhibit strong robustness to external and stochastic perturbations.

Strain rate sensitivity of skin tissue under thermomechanical loading

There have been limited studies addressing the thermally dependent mechanical properties of skin tissue, although this can contribute to a variety of medical applications. To address this, an experimental study on the tensile behaviour of pig skin tissue under different thermal loading conditions and different mechanical stretching rates was performed. The results indicate that there is a significant variation among skin tensile behaviours under different temperatures and loading rates, which is correlated with dermal collagen denaturation. The Ogden model was used to summarize the effect of the strain rate and the temperature upon the measured constitutive response through two parameters (alpha and mu). These results can be used in future models to improve clinical thermal treatments for skin tissue.

Development of boron-efficient near isogenic lines of Brassica napus and their response to low boron stress at seedling stage

Rapeseed (Brassica napus) is sensitive to low boron (B) stress and plentiful variation exists in response to B deficiency. One major QTL, BE1, and three minor loci controlling B efficiency in Brassica napus were previously detected. To fine map and clone the B-efficient gene (s), the development of B-efficient NILs in Brassica napus was conducted, combining the identification of B efficiency at seedling stage with genetic background selection using random AFLP markers. The molecular marker assisted background selection proved its optimum and necessary in an early backcrossing generation to select the backcross individuals with high genetic background similarity to accelerate the construction of NILs. Based on B efficiency investigated at seedling stage under the low B conditions, the B-efficient backcross line can produce biomass twice about the B-inefficient parent's and show low B concentration and effective utilization of B under low B condition. Thus, the B efficiency of the B efficient NILs might be attributed to the higher B utilization efficiency or less demand for B.

Molecular and enzymatic profiles of mammalian DNA methyltransferases: structures and targets for drugs

DNA methylation is an epigenetic event involved in a variety array of processes that may be the foundation of genetic phenomena and diseases. DNA methyltransferase is a key enzyme for cytosine methylation in DNA, and can be divided into two functional families (Dnmt1 and Dnmt3) in mammals. All mammalian DNA methyltransferases are encoded by their own single gene, and consisted of catalytic and regulatory regions (except Dnmt2). Via interactions between functional domains in the regulatory or catalytic regions and other adaptors or cofactors, DNA methyltransferases can be localized at selective areas (specific DNA/nucleotide sequence) and linked to specific chromosome status (euchromatin/heterochromatin, various histone modification status). With assistance from UHRF1 and Dnmt3L or other factors in Dnmt1 and Dnmt3a/Dnmt3b, mammalian DNA methyltransferases can be recruited, and then specifically bind to hemimethylated and unmethylated double-stranded DNA sequence to maintain and de novo setup patterns for DNA methylation. Complicated enzymatic steps catalyzed by DNA methyltransferases include methyl group transferred from cofactor Ado-Met to C5 position of the flipped-out cytosine in targeted DNA duplex. In the light of the fact that different DNA methyltransferases are divergent in both structures and functions, and use unique reprogrammed or distorted routines in development of diseases, design of new drugs targeting specific mammalian DNA methyltransferases or their adaptors in the control of key steps in either maintenance or de novo DNA methylation processes will contribute to individually treating diseases related to DNA methyltransferases.