Hyperbranched polyglycerol electrospun nanofibers for wound dressing applications

This study reports on the performance of electrospun hyperbranched polyglycerol nanofibers capable of providing an active agent delivery for wound dressing applications. The aim of this work was to prepare electrospun HPGL nanofibers containing Calendula officinalis as a wound-healing and anti-inflammatory agent. The morphology of the electrospun HPGL–C. officinalis nanofibers was analyzed using a scanning electron microscope. The results showed that the diameters of the fibers were in nanoscales. The release of C. officinalis from the electrospun HPGL fibers was determined by HPLC at a physiological temperature (37 °C). Rapid release of the C. officinalis from the electrospun HPGL–C. officinalis nanofibers was exhibited as result of the high swelling ability as well as the high porosity of the electrospun HPGL–C. officinalis membranes. The degree of swelling, and the mechanical and biocompatible properties of the electrospun HPGL fibers were determined. The results showed that, in physiological conditions, the water absorption into the HPGL electrospun fibers slowed down, governed by the rate at which the electrospun HPGL–C. officinalis membranes interacted with the physiological fluid. The rate of release of C. officinalis seemed to depend on the C. officinalis content in the HPGL nanofibers. From the elastic modulus, it could be seen that elastic electrospun HPGL fibers were obtained with increments of C. officinalis content in the HPGL–C. officinalis membranes. The results of in vivo experiments in rats suggested that HPGL–C. officinalis might be an interesting bioactive wound dressing material for clinical applications.     

Loading and release of doxycycline hyclate from strontium-substituted calcium phosphate cement

Novel Sr-substituted calcium phosphate cement (CPC) loaded with doxycycline hyclate (DOXY-h) was employed to elucidate the effect of strontium substitution on antibiotic delivery. The cement was prepared using as reactants Sr-substituted β-tricalcium phosphate (Sr-β-TCP) and acidic monocalcium phosphate monohydrate. Two different methods were used to load DOXY-h: (i) the adsorption on CPC by incubating the set cement in drug-containing solutions; and (ii) the use of antibiotic solution as the cement liquid phase. The results revealed that the Sr-substituted cement efficiently adsorbs the antibiotic, which is attributed to an enhanced accessibility to the drug-binding sites within this CPC. DOXY-h desorption is influenced by the initial adsorbed amount and the cement matrix type. Furthermore, the fraction of drug released from CPCs set with DOXY-h solution was higher, and the release rate was faster for the CPC prepared with 26.7% Sr-β-TCP. The analysis of releasing profiles points to Fickian diffusion as the mechanism responsible for antibiotic delivery. We can conclude that Sr substitution in secondary calcium phosphate cements improves their efficiency for DOXY-h adsorption and release. The antibiotic loading method provides a way to switch from rapid and complete to slower and prolonged drug release.     

Oncogenic KRAS is not necessary for Wnt signalling activation in APC‐associated FAP adenomas

Recent studies have suggested that APC loss alone may be insufficient to promote aberrant Wnt/β‐catenin signalling. Our aim was to comprehensively characterize Wnt signalling components in a set of APC‐associated familial adenomatous polyposis (FAP) tumours. Sixty adenomas from six FAP patients with known pathogenic APC mutations were included. Somatic APC and KRAS mutations, β‐catenin immunostaining, and qRT‐PCR of APC, MYC, AXIN2 and SFRP1 were analysed. Array‐comparative genomic hybridization (aCGH) was also assessed in 26 FAP adenomas and 24 paired adenoma–carcinoma samples. A somatic APC alteration was present in 15 adenomas (LOH in 11 and four point mutations). KRAS mutations were detected in 10% of the cases. APC mRNA was overexpressed in adenomas. MYC and AXIN2 were also overexpressed, with significant intra‐case heterogeneity. Increased cytoplasmic and/or nuclear β‐catenin staining was seen in 94% and 80% of the adenomas. β‐Catenin nuclear staining was strongly associated with MYC levels (p value 0.03) but not with KRAS mutations. Copy number aberrations were rare. However, the recurrent chromosome changes observed more frequently contained Wnt pathway genes (p value 0.012). Based on β‐catenin staining and Wnt pathway target genes alterations the Wnt pathway appears to be constitutively activated in all APC‐FAP tumours, with alterations occurring both upstream and downstream of APC. Wnt aberrations are present at both the DNA and the RNA level. Somatic profiling of APC‐FAP tumours provides new insights into the role of APC in tumourigenesis. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Outbreak caused by a multi-resistant Klebsiella pneumoniae strain of new sequence type ST341 carrying new genetic environments of aac(6′)-Ib-cr and qnrS1 genes in a neonatal intensive care unit in Spain

An outbreak due to a Klebsiella pneumoniae clone occurred in a neonatal intensive care unit of a Spanish Hospital in which three newborns were infected (all with gestational age ≤29 weeks; two of them died) and seven were colonized (gestational age >32 weeks; none died). One K. pneumoniae strain per patient was further characterized. The 10 strains showed an indistinguishable pulsed-field-gel-electrophoresis pattern, were typed in the phylogenetic group KpI and were ascribed into a new sequence type registered as ST341. All 10 strains presented the same multiple-antibiotic-resistant phenotype, showed extended-spectrum-beta-lactamase production, and harbored the bla_CTX-M-15, bla_SHV-11, bla_OXA-1,aac(6′)-Ib-cr, qnrS1, aac(3)-II, aph(3′)-Ia and aadA5 resistance genes. No class 1 or class 2 integrons were detected. The bla_CTX-M-15 gene presented the following genetic environment: ISEcp1-bla_CTX-M-15-orf477. These strains contained two copies of the aac(6′)-Ib-cr gene included in the following new genetic environments: aac(3)-II-IS26-aac(6′)-Ib-cr-bla_OXA-1 and aac(3)-II-IS26-ΔcatB3-bla_OXA-1-aac(6′)-Ib-cr (registered at GenBank with accession numbers GQ438247 and GQ438248, respectively). The genetic environment of the qnrS1 gene (IS26-ΔISEcl2-qnrS1) (GenBank accession number GQ438249) was also not described previously. The aac(6′)-Ib-cr, qnrS1, bla_CTX-M-15, aac(3)-II, and bla_OXA-1 genes, located in a plasmid of 33.5 kb, could be transferred to Escherichia coli by transformation.     

Temporal parameters of the foot roll-over during walking: Influence of obesity and sarcopenic obesity on postmenopausal women

Objectives

The purpose of this study was to establish a reference dataset for temporal parameters on postmenopausal women during walking and to explore the effect of obesity and sarcopenic obesity on the same parameters.

Methods

Based on plantar pressure data collected from 239 postmenopausal women, the initial contact, final contact, time to peak pressure and the duration of contact at the 10 anatomical areas of the foot considered were measured. Body composition was evaluated by octopolar bioimpedance.

Results

Non-obese and non-sarcopenic started with heel contact followed by a latero-medial contact of the metatarsals and finally the hallux (the sarcopenic obese group ended in the toes 2–5). After heel off, the forefoot started to push off at the lateral metatarsals, followed by a more central push off and finally over the hallux (the sarcopenic obese group presented a greater oscillation in the metatarsals). The stance phase was divided into four distinct phases: initial contact (22.30%), forefoot contact (19.98%), foot flat (13.40%) and forefoot push off (44.32%). Sarcopenic obese spent more time in the forefoot contact phase (relative and absolute) and less time in the initial contact phase (%).

Conclusions

These findings provide a reliable and representative reference dataset for temporal characteristics of foot roll-over during walking of postmenopausal women. Sarcopenic obesity affects significantly the temporal characteristics of foot roll-over during walking in this population. Such findings are of concern to clinicians interested in the promotion of activity to reduce obesity and gain or maintain muscle, since sarcopenic obesity affects normal walking, which might increase injuries.     

Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63

Waanders E, Venselaar H, te Morsche RHM, de Koning DB, Kamath PS, Torres VE, Somlo S, Drenth JPH. Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63. Polycystic liver disease (PCLD) is characterized by intralobular bile duct cysts in the liver. It is caused by mutations in PRKCSH, encoding hepatocystin, and SEC63, encoding Sec63p. The main goals of this study were to screen for novel mutations and to analyze mutations for effects on protein structure and function. We screened 464 subjects including 76 probands by direct sequencing or conformation‐sensitive capillary electrophoresis. We analyzed the effects of all known and novel mutations using a combination of splice site recognition, evolutionary conservation, secondary and tertiary structure predictions, Poly Phen , and p Mut and sift . We identified a total of 26 novel mutations in PRKCSH (n = 14) and SEC63 (n = 12), including four splice site mutations, eight insertions/ deletions, six non‐sense mutations, and eight missense mutations. Out of 48 PCLD mutations, 13 were predicted to affect splicing. Most mutations were located in highly conserved regions and homology modeling for two domains of Sec63p showed severe effects of the residue substitutions. In conclusion, we identified 26 novel mutations associated with PCLD and we provide in silico analysis in order to delineate the role of these mutations.     

Mapping the Spatiotemporal Dynamics of Calcium Signaling in Cellular Neural Networks Using Optical Flow

An optical flow gradient algorithm was applied to spontaneously forming networks of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling with single pixel resolution. Optical flow estimates the direction and speed of motion of objects in an image between subsequent frames in a recorded digital sequence of images (i.e., a movie). Computed vector field outputs by the algorithm were able to track the spatiotemporal dynamics of calcium signaling patterns. We begin by briefly reviewing the mathematics of the optical flow algorithm, and then describe how to solve for the displacement vectors and how to measure their reliability. We then compare computed flow vectors with manually estimated vectors for the progression of a calcium signal recorded from representative astrocyte cultures. Finally, we applied the algorithm to preparations of primary astrocytes and hippocampal neurons and to the rMC-1 Muller glial cell line in order to illustrate the capability of the algorithm for capturing different types of spatiotemporal calcium activity. We discuss the imaging requirements, parameter selection and threshold selection for reliable measurements, and offer perspectives on uses of the vector data.     

Mutagenicity,antioxidant potential,and antimutagenic activity against hydrogen peroxide of cashew (Anacardium occidentale) apple juice and cajuina

Fresh and processed cashew (Anacardium occidentale) apple juice (CAJ) are among the most popular drinks in Brazil. Besides their nutritional benefits, these juices have antibacterial and antitumor potential. The chemical constituents of both the fresh juice and the processed juice (cajuina) were analyzed and characterized as complex mixtures containing high concentrations of vitamin C, various carotenoids, phenolic compounds, and metals. In the present study, these beverages exhibited direct and rat liver S9-mediated mutagenicity in the Salmonella/microsome assay with strains TA97a, TA98, and TA100, which detect frameshifts and base pair substitution. No mutagenicity was observed with strain TA102, which detects oxidative and alkylating mutagens and active forms of oxygen. Both CAJ and cajuina showed antioxidant activity as determined by a total radical-trapping potential assay. To test whether this antioxidant potential might result in antimutagenesis, we used a variation of the Salmonella/microsome assay that included pre-, co-, and posttreatment of hydrogen peroxide-exposed Salmonella typhimurium strain TA102 with the juices. CAJ and cajuina protected strain TA102 against mutation by oxidative damage in co- and posttreatments. The antimutagenic effects during cotreatment with hydrogen peroxide may be due to scavenging free radicals and complexing extracellular mutagenic compounds. The protective effects in posttreatment may be due to stimulation of repair and/or reversion of DNA damage. The results indicate that CAJ and cajuina have mutagenic, radical-trapping, antimutagenic, and comutagenic activity and that these properties can be related to the chemical constituents of the juices.     

Clinical aspects of Candida species carriage in saliva of xerotomic subjects.

In order to investigate the clinical factors that might influence the diversity and the degree of Candida species carriage in saliva, we conducted a cross-sectional study with 133 patients with complaints of xerostomia. Anamnesis, oral examination and collection of chewing-stimulated whole saliva were performed. The samples of saliva were kept refrigerated until they were plated onto CHROMagar Candida; cfu were counted and Candida species were identified by standard methods. There was a high prevalence of mixed Candida colonization. No relationship was found between total Candida cfu counts and variables like gender, age, place of origin, underlying diseases, exposure to medications (except antibiotics), daily habits and salivary flow rates. Oral candidiasis, antibiotic exposure and dental prosthesis wearing were associated with relatively high Candida counts in saliva. Low salivary flow rates predisposed to intense colonization by C. albicans and C. parapsilosis.