Engineering of a complex bone tissue model with endothelialised channels and capillary-like networks.

In engineering of tissue analogues, upscaling to clinically-relevant sized constructs remains a significant challenge. The successful integration of a vascular network throughout the engineered tissue is anticipated to overcome the lack of nutrient and oxygen supply to residing cells. This work aimed at developing a multiscale bone-tissue-specific vascularisation strategy. Engineering pre-vascularised bone leads to biological and fabrication dilemmas. To fabricate channels endowed with an endothelium and suitable for osteogenesis, rather stiff materials are preferable, while capillarisation requires soft matrices. To overcome this challenge, gelatine-methacryloyl hydrogels were tailored by changing the degree of functionalisation to allow for cell spreading within the hydrogel, while still enabling endothelialisation on the hydrogel surface. An additional challenge was the combination of the multiple required cell-types within one biomaterial, sharing the same culture medium. Consequently, a new medium composition was investigated that simultaneously allowed for endothelialisation, capillarisation and osteogenesis. Integrated multipotent mesenchymal stromal cells, which give rise to pericyte-like and osteogenic cells, and endothelial-colony-forming cells (ECFCs) which form capillaries and endothelium, were used. Based on the aforementioned optimisation, a construct of 8 × 8 × 3 mm, with a central channel of 600 µm in diameter, was engineered. In this construct, ECFCs covered the channel with endothelium and osteogenic cells resided in the hydrogel, adjacent to self-assembled capillary-like networks. This study showed the promise of engineering complex tissue constructs by means of human primary cells, paving the way for scaling-up and finally overcoming the challenge of engineering vascularised tissues.

Genomic and Transcriptomic Approaches to Study Cancer in Small Aquarium Fish Models.

Zebrafish and medaka that develop tumors have become valuable tools for experimental cancer research. With the advent of microarrays and new sequencing technologies it has become feasible to perform whole genome, exome, and transcriptome analyses in these fish models. Analyses that compare the two fish models with each other and with data from human tumors have revealed a plethora of important insights. An unexpected high degree of comparability of molecular features of fish and human tumors has been detected. Furthermore, analyses of the fish model data have uncovered molecules that have not received appropriate attention in studies on their human tumor counterparts and thus have provided valuable candidates for novel biomarkers and therapeutic targets.

Effects of high hydrostatic pressure and temperature increase on Escherichia coli spp. and pectin methyl esterase inactivation in orange juice.

The aim of this study was to evaluate the effect of high hydrostatic pressure treatment combined with moderate processing temperatures (25 ℃-50 ℃) on the inactivation of Escherichia coli O157: H7 (ATCC 700728), E. coli K12 (ATCC 23716), and pectin methyl esterase in orange juice, using pressures of 250 to 500 MPa with times ranging between 1 and 30 min. Loss of viability of E. coli O157:H7 increased significantly as pressure and treatment time increased, achieving a 6.5 log cycle reduction at 400 MPa for 3 min at 25 ℃ of treatment. With regard to the inactivation of pectin methyl esterase, the greatest reduction obtained was 90.05 ± 0.01% at 50 ℃ and 500 MPa of pressure for 15 min; therefore, the pectin methyl esterase enzyme was highly resistant to the treatments by high hydrostatic pressure. The results obtained in this study showed a synergistic effect between the high pressure and moderate temperatures in inactivating E. coli cells.

FT-IR product study of the reactions of NO3 radicals with ortho-, meta-, and para-cresol.

Product analyses of the NO3 radical-initiated oxidation of ortho-, meta-, and para-cresol have been performed in large-volume chamber systems at the University of Wuppertal (1080 L quartz glass reactor: QUAREC) and the European Photoreactor (EUPHORE), Valencia, Spain. The reaction of O3 with NO2 was used for the in situ generation of NO3 radicals in both QUAREC and EUPHORE. In the QUAREC experiments the gas-phase reaction of ortho-cresol isomer with NO3 yielded (11.5 ± 0.8) % 6-methyl-2-nitrophenol (6M2NP), (4.4 ± 0.3) % methyl-1,4-benzoquinone (MQUIN) and (77.2 ± 6.3) % HNO3. The reaction of NO3 radicals with meta-cresol yielded (21.2 ± 1.4) % 3-methyl-2-nitrophenol (3M2NP), (22.8 ± 1.8) % 3-methyl-4-nitrophenol (3M4NP), (23.5 ± 1.8) % 5-methyl-2-nitrophenol (5M2NP), (4.2 ± 0.7) % MQUIN and (72.3 ± 6.4) % HNO3. In the reaction of NO3 radicals with para-cresol, 4-methyl-2-nitrophenol (4M2NP) and HNO3 were identified as products with yields of (41.3 ± 3.7) % and (85.0 ± 10.2) %, respectively. In the EUPHORE chamber not all products were formed at levels above the detection limit, however, in cases where detection was possible similar product yields were observed. The product formation yields determined in both chambers are compared with available literature data and a gas-phase mechanism is proposed to explain the formation of the products observed from the reaction of NO3 and with cresol isomers.

In vivo corrosion, tumor outcome, and microarray gene expression for two types of muscle-implanted tungsten alloys.

Tungsten alloys are composed of tungsten microparticles embedded in a solid matrix of transition metals such as nickel, cobalt, or iron. To understand the toxicology of these alloys, male F344 rats were intramuscularly implanted with pellets of tungsten/nickel/cobalt, tungsten/nickel/iron, or pure tungsten, with tantalum pellets as a negative control. Between 6 and 12 months, aggressive rhabdomyosarcomas formed around tungsten/nickel/cobalt pellets, while those of tungsten/nickel/iron or pure tungsten did not cause cancers. Electron microscopy showed a progressive corrosion of the matrix phase of tungsten/nickel/cobalt pellets over 6 months, accompanied by high urinary concentrations of nickel and cobalt. In contrast, non-carcinogenic tungsten/nickel/iron pellets were minimally corroded and urinary metals were low; these pellets having developed a surface oxide layer in vivo that may have restricted the mobilization of carcinogenic nickel. Microarray analysis of tumors revealed large changes in gene expression compared with normal muscle, with biological processes involving the cell cycle significantly up-regulated and those involved with muscle development and differentiation significantly down-regulated. Top KEGG pathways disrupted were adherens junction, p53 signaling, and the cell cycle. Chromosomal enrichment analysis of genes showed a highly significant impact at cytoband 7q22 (chromosome 7) which included mouse double minute (MDM2) and cyclin-dependant kinase (CDK4) as well as other genes associated with human sarcomas. In conclusion, the tumorigenic potential of implanted tungsten alloys is related to mobilization of carcinogenic metals nickel and cobalt from corroding pellets, while gene expression changes in the consequent tumors are similar to radiation induced animal sarcomas as well as sporadic human sarcomas.

Organic aerosol formation during the atmospheric degradation of toluene.

Organic aerosol formation during the atmospheric oxidation of toluene was investigated using smog chamber systems. Toluene oxidation was initiated by the UV irradiation of either toluene/air/NOx or toluene/air/CH3ONO/NO mixtures. Aerosol formation was monitored using scanning mobility particle sizers and toluene loss was monitored by in-situ FTIR spectroscopy or GC-FID techniques. The experimental results show that the reaction of OH radicals, NO3 radicals and/or ozone with the first generation products of toluene oxidation are sources of organic aerosol during the atmospheric oxidation of toluene. The aerosol results fall into two groups, aerosol formed in the absence and presence of ozone. An analytical expression for aerosol formation is developed and values are obtained for the yield of the aerosol species. In the absence of ozone the aerosol yield, defined as aerosol formed per unit toluene consumed once a threshold for aerosol formation has been exceeded, is 0.075 +/- 0.004. In the presence of ozone the aerosol yield is 0.108 +/- 0.004. This work provides experimental evidence and a simple theory confirming the formation of aerosol from secondary reactions.

[Cheyletiella dermatitis: an uncommon cause of vesiculobullous eruption]. / La cheyletellose: une etiologie inhabituelle d'eruption vésiculo- bulleuse.

BACKGROUND: Species of Cheyletiella mites are parasites hosted by dogs, cats and rabbits. In humans, they cause a dermatosis not well known by dermatologists. We report a case of an unusual, purely vesiculobullous eruption due to Cheyletiella blakei acquired from an infected cat. CASE REPORT: A 76-year-old woman presented a very pruritic eruption of vesicles and bullous lesions located on the trunk and external areas of the arms. Biopsy showed dermoepidermal cleavage and polynuclear infiltrate with prominent eosinophils, consistent with the diagnosis of bullous pemphigoid. We suspected a Cheyletiella dermatitis due to the aspect and distribution of the elementary lesions and the fact that prior to the eruption the patient had acquired a cat that sometimes slept in her bed. The diagnosis was confirmed by a veterinary examination and isolation of Cheyletiella blakei from the cat's skin. The cat was treated successfully with ivermectin, while the household was disinfected with permethrin. A treatment with benzyl benzoate (Ascabiol) resolved all the patient's symptoms. DISCUSSION: This case is particularly interesting due to the purely vesiculobullous pattern of the rash and by the difficulty and considerable delay of diagnosis. Patients who have recently acquired a cat or dog before developing a pruritic dermatosis may indeed have cheyletiellosis.

[Self assessment and actual intelligibility of speech audiometry test material]. / Selbstgeschätzte und tatsächliche Verständlichkeit sprachaudiometrischen Testmaterials.

Self-estimated and measured intelligibility were compared using different instructions in speech audiometric tests. The results of 69 tested persons reveal that there exist speech levels in both test procedures where the intelligibility reaches 0% or 100%, respectively. In general, self-estimated intelligibility was significantly higher than real identification. Therefore, the self-estimation of intelligibility does not appear as an appropriate procedure to automated speech audiometry. The results are a speech audiometric equivalent of the subject's to have correctly understood speech in daily life in which in fact was misunderstood. Connections to central speech processing seem to be possible. Audiologists might be influenced by the effect of overestimation of speech intelligibility as well. However, preliminary investigations concerning pseudohypacusis show different results.

[Extrapulmonary intrathoracic pneumocystosis. Apropos of 4 cases in HIV positive patients]. / Pneumocystoses intra-thoraciques extra-pulmonaires.

The authors report 4 cases of intrathoracic extrapulmonary pneumocystosis; 3 of them involved the pleura and 1 the mediastinal lymph nodes. As in other rare but apparently increasingly frequent cases, everything seemed to incriminate the use of prophylactic Pentamidine aerosols, but only a prospective study of systemic versus aerosol prophylaxis can confirm this suspicion.

Changes in the central ANF-system of renovascular hypertensive rats.

The central atrial natriuretic peptides (ANF)-system was investigated in volume-dependent, one-kidney, one-clip (1K1C) and renin-dependent two-kidney, one-clip (2K1C) renovascular hypertensive rats by radioimmunological measurement of ANF concentration in 18 selected brain areas. Significant changes were found in nine brain areas of 1K1C and in eight brain areas of 2K1C hypertensive rats. Except undirectional changes in the organum vasculosum laminae terminalis and the supraoptic nucleus, ANF concentration was changed in the opposite direction in all other brain areas, with an activation of the central ANF system in 1K1C and an inhibition in 2K1C hypertension. The localization of the alterations (circumventricular organs, anteroventral third ventricle region, hypothalamo hypophyseal system, brain stem) implies major differences in the central regulation of blood pressure and electrolyte and fluid homeostasis between these two models. The activation of the central ANF system in 1K1C hypertension may be a compensatory mechanism to prevent further increments in blood pressure and plasma volume. In contrast, the depression of the central ANF system in 2K1C hypertension may promote the elevation of the blood pressure.