Correction to: Gene Therapy advance online publication, 12 May 2011; doi:10.1038/gt.2011.66 Since the online publication of this paper the authors have noticed that Figure 2 is incorrect. The Doppler ...data are missing in panels i and j. The correct figure is shown below. The authors would like to apologise for this error.
This paper focuses on understanding and developing learning environments for computer science education. We present two models that we have successfully used in European and African contexts. The ...first model, Computer Science Learning Environments (CSLE), presents seven dimensions of computer science courses, which should be considered in learning environment design for computer science. The second model, Investigative Learning Environment (ILE), presents an action plan model, inspired by action research, for combining educational research and computer science teaching. In the empirical section we outline two case studies where these models were used to design and implement computer science learning environments in two different learning contexts. In the first case in University of Helsinki, Finland, we developed and studied a method of learning-by-inventing in a robotics programming course. That course was designed around problem discovery and inventing, and it employed LEGO® Mindstorms robots. In the second case in Tumaini University, Tanzania, we designed an environment for studying and improving introductory programming courses. Both models showed to be useful for designing, implementing, developing, and analyzing the courses in both learning contexts.
The aim of this study was to characterize the amino acid sequence of a selected Stachybotrys chartarum component and to investigate human IgE reactivity against components of S. chartarum and nine ...other fungal species.
Human IgE reactivity against S. chartarum and nine other fungal extracts was investigated by the immunoblotting method. For automated amino acid sequencing analyses, the S. chartarum extract was purified by ion exchange chromatography prior to in-gel alkylation and digestion with modified trypsin.
Human IgE reactivity was detected against eight components in the S. chartarum extract. Over 80% of the sera from the exposed subjects and less than 50% of the control sera recognized the 33-, 48- and 50-kD S. chartarum components. The human sera detected a 48- to 50-kD component from the extracts of eight fungal species. Nineteen peptide sequences were identified from the 48-kD component of S. chartarum. An analysis of the peptide sequences revealed homology with known fungal glycoside hydrolase enzymes (cellulases).
The data showed human IgE reactivity against several S. chartarum components, including one at 48 kD. On the other hand, the human sera recognized 48- to 50-kD components from seven other fungal species, suggesting shared antigenic components (e.g. enolase) between the fungi. Thus, to our knowledge, this is the first antigen identified from S. chartarum.
Several sources of man-made vitreous fibers (MMVFs) may exist in an office environment causing irritation symptoms among occupants. In 258 office buildings, the occurrence and density of settled ...MMVFs on surfaces were measured by two sampling methods. Altogether, 1113 samples of settled dust were collected from surfaces with plastic bags and gelatine tape and were analyzed with a scanning electron microscope and a stereomicroscope, respectively. Tape samples from 68 buildings were collected from frequently cleaned (n = 162) and seldom cleaned (n = 57) room surfaces in 56 and 29 offices, respectively, and from supply air ducts (n = 24) in 10 offices. MMVFs longer than 20 μm were counted with a stereomicroscope. Irritation symptoms were recorded with a questionnaire. More than 60% of the surface dust and almost 90% of the samples collected from supply air ducts contained MMVFs. The density of MMVFs longer than 20 μm ranged from < 0.1 to 5 fiber cm
− 2
. The mean density of the MMVFs was about two times higher on the seldom cleaned surfaces than on the frequently cleaned surfaces. The density was usually under 0.2 MMVF cm
− 2
in surface dust of offices without emission sources of MMVFs. The measurements combined with qualitative analysis of settled dust can help to localize relevant sources of fiber emissions. Altogether, in 40% of the buildings, several occupants had repeated irritation symptoms that were verified by occupational health care personnel.
This study presents a novel exposure protocol for synthesized nanoparticles (NPs). NPs were synthesized in gas phase by thermal decomposition of metal alkoxide vapors in a laminar flow reactor. The ...exposure protocol was used to estimate the deposition fraction of titanium dioxide (TiO
2
) NPs to mice lung. The experiments were conducted at aerosol mass concentrations of 0.8, 7.2, 10.0, and 28.5 mg m
−3
. The means of aerosol geometric mobility diameter and aerodynamic diameter were 80 and 124 nm, and the geometric standard deviations were 1.8 and 1.7, respectively. The effective density of the particles was approximately from 1.5 to 1.7 g cm
−3
. Particle concentration varied from 4 × 10
5
cm
−3
at mass concentrations of 0.8 mg m
−3
to 12 × 10
6
cm
−3
at 28.5 mg m
−3
. Particle phase structures were 74% of anatase and 26% of brookite with respective crystallite sized of 41 and 6 nm. The brookite crystallites were approximately 100 times the size of the anatase crystallites. The TiO
2
particles were porous and highly agglomerated, with a mean primary particle size of 21 nm. The specific surface area of TiO
2
powder was 61 m
2
g
−1
. We defined mice respiratory minute volume (RMV) value during exposure to TiO
2
aerosol. Both TiO
2
particulate matter and gaseous by-products affected respiratory parameters. The RMV values were used to quantify the deposition fraction of TiO
2
matter by using two different methods. According to individual samples, the deposition fraction was 8% on an average, and when defined from aerosol mass concentration series, it was 7%. These results show that the exposure protocol can be used to study toxicological effects of synthesized NPs.
Osteosarcoma and chondrosarcoma, the most prevalent primary malignant tumors of the bone, have been demonstrated to be potential target diseases for herpes simplex virus type 1 thymidine kinase ...(HSV-TK)/ganciclovir (GCV) suicide gene therapy. However, the utility of this gene therapy form for bone tumor cells has not been studied systematically. In this report we show, with the aid of three osteosarcoma cell lines (Saos-2, U-2-OS and MG-63) and one chondrosarcoma cell line (SW1353) that: i) these tumor cells were permissive for adenovirus- or lentivirus-mediated gene delivery; ii) the cell lines appeared to be good or excellent targets for HSV-TK/GCV gene therapy; and iii) the extent of HSV-TK/GCV cytotoxic effect correlated with the presence of the 'bystander effect' in these cells. Our results also suggest that lentiviruses are potential vectors for bone cancer gene therapy. They transduced all four cell lines with high efficiency and provided HSV-TK expression level that was sufficient for cytotoxicity and bystander effect comparable to that obtained with adenovirus vectors.
Farmers' exposure to airborne dust, fungi and possibly also to
Fusarium toxins during the drying and milling of grain and feeding of cattle was studied on eight Finnish farms. Airborne viable and ...total spores were collected on polycarbonate filters. Spore concentrations and fungal flora were determined by cultivation and epifluorescence microscope counting. Eighteen airborne dust samples were taken on glass-fiber filters with a high-volume sampler, and biological toxicity was tested from those samples. In toxic dust samples,
Fusarium toxins were analyzed with a gas chromatography-mass spectroscopy. Fungi and
Fusarium toxins were also analyzed in ten grain samples collected from the farms during the air sampling. Yeasts, as well as species of
Cladosporium, Penicillium, Aspergillus, Absidia and
Fusarium occurred in the air at all three stages of grain handling. Airborne spore concentrations ranged from 103 to 10
6 cfu m
−3 for viable fungi and from 10
5 to 10
7 spores m
−3 for total spores; airborne dust concentrations varied from 0.04 to 81.1 mg m
−3. Low deoxynivalenol concentrations (3 and 20 ng m
−3) were found in two air samples collected during milling.
Fusarium spp. were identified in eight grain samples, and DON concentrations of 0.004–11 mg kg
−1 were detected in all samples analyzed. Although any conclusion on Finnish farmers' exposure to mycotoxins cannot be done on the basis of this small data, it can be assumed that toxigenic fungi and
Fusarium toxins may occur in the air and inhalation exposure of farmers to
Fusarium toxins is possible in agricultural environment.
Lung cancer is a group of diseases that are difficult to cure and new treatment modalities, like gene therapy are actively tested to find alternatives for currently used strategies. Herpes simplex ...virus thymidine kinase/ganciclovir (HSV-TK/GCV) method is one of the most frequently utilized forms of gene therapy and it has been tested on lung cancer, but no systematic study with comparison of different lung cancer types has been published. In this study, we examined in vitro and in vivo how good targets non-small cell lung cancer (NSCLC) cell lines representing adenocarcinoma, squamous cell lung cancer and large cell lung cancer are for adenovirus-mediated HSV-TK/GCV gene therapy. By using an adenovirus vector carrying a fusion gene of HSV-TK and green fluorescent protein (GFP), we found that: a) adenoviruses were efficient gene transfer vehicles for all types of NSCLCs; b) all adenocarcinoma and large cell lung cancer cells were good targets for HSV-TK/GCV therapy, whereas one of the squamous cell carcinoma cell lines was not responsive to the treatment; c) bystander effect played a major role in the success of this gene therapy form; d) subcutaneous tumors representing all three NSCLC types were efficiently treated with adenovirus-mediated HSV-TK/GCV gene therapy. In summary, this form of gene therapy appeared to be efficient treatment for human NSCLC and these results warrant further studies with primary lung cancer cells and orthotopic lung tumor models.
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