85 research outputs found
A probable outbreak of toxoplasmosis among boarding school students in Turkey
ABSTRACTIn total, 171 students from a boarding school in Izmir, Turkey, with mild and non-specific symptoms of toxoplasmosis, were screened during September–October 2002. All 171 students were seropositive for Toxoplasma gondii IgG and IgM. Of 43 students tested, 40 (93%) had low IgG avidity. None showed evidence of ophthalmic involvement. The data suggest that T. gondii may spread rapidly in close living conditions, possibly following exposure to cat litter. This is the largest recent outbreak of toxoplamosis described in the medical literature
Putative Nanobacteria Represent Physiological Remnants and Culture By-Products of Normal Calcium Homeostasis
Putative living entities called nanobacteria (NB) are unusual for their small sizes (50–500 nm), pleomorphic nature, and accumulation of hydroxyapatite (HAP), and have been implicated in numerous diseases involving extraskeletal calcification. By adding precipitating ions to cell culture medium containing serum, mineral nanoparticles are generated that are morphologically and chemically identical to the so-called NB. These nanoparticles are shown here to be formed of amorphous mineral complexes containing calcium as well as other ions like carbonate, which then rapidly acquire phosphate, forming HAP. The main constituent proteins of serum-derived NB are albumin, fetuin-A, and apolipoprotein A1, but their involvement appears circumstantial since so-called NB from different body fluids harbor other proteins. Accordingly, by passage through various culture media, the protein composition of these particles can be modulated. Immunoblotting experiments reveal that antibodies deemed specific for NB react in fact with either albumin, fetuin-A, or both, indicating that previous studies using these reagents may have detected these serum proteins from the same as well as different species, with human tissue nanoparticles presumably absorbing bovine serum antigens from the culture medium. Both fetal bovine serum and human serum, used earlier by other investigators as sources of NB, paradoxically inhibit the formation of these entities, and this inhibition is trypsin-sensitive, indicating a role for proteins in this inhibitory process. Fetuin-A, and to a lesser degree albumin, inhibit nanoparticle formation, an inhibition that is overcome with time, ending with formation of the so-called NB. Together, these data demonstrate that NB are most likely formed by calcium or apatite crystallization inhibitors that are somehow overwhelmed by excess calcium or calcium phosphate found in culture medium or in body fluids, thereby becoming seeds for calcification. The structures described earlier as NB may thus represent remnants and by-products of physiological mechanisms used for calcium homeostasis, a concept which explains the vast body of NB literature as well as explains the true origin of NB as lifeless protein-mineralo entities with questionable role in pathogenesis
Persistent Seroconversion after Accidental Eye Exposure to Calcifying Nanoparticles
Biosafety of nanomaterials has attracted much attention recently. We report here a case where accidental human eye exposure to biogenic nanosized calcium phosphate in the form of calcifying nanoparticles (CNP) raised a strong IgG immune response against proteins carried by CNP. The antibody titer has persisted over ten years at the high level. The IgG was detected by ELISA using CNPs propagated in media containing bovine and human serum as antigen. The exposure incident occurred to a woman scientist (WS) at a research laboratory in Finland at 1993. CNP, also termed "nanobacteria", is a unique self-replicating agent that has not been fully characterized and no data on biohazards were available at that time. Before the accident, her serum samples were negative for both CNP antigen and anti-CNP antibody using specific ELISA tests (Nanobac Oy, Kuopio, Finland). The accident occurred while WS was harvesting CNP cultures. Due to a high pressure in pipetting, CNP pellet splashed into her right eye. Both eyes were immediately washed with water and saline. The following days there was irritation and redness in the right eye. These symptoms disappeared within two weeks without any treatment. Three months after the accident, blood and urine samples of WS were tested for CNP cultures (2), CNP-specific ELISA tests, and blood cell counts. Blood cell counts were normal, CNP antigen and culture tests were negative. A high IgG anti-CNP antibody titer was detected (see Figure). The antibodies of this person have been used thereafter as positive control and standard in ELISA manufacturing (Nano-Sero IgG ELISA, Nanobac Oy, Kuopio, Finland)
Association between Randall's Plaque and Calcifying Nanoparticles
Randall's plaques, first described by Alexander Randall in the 1930s, are small subepithelial calcifications in the renal papillae (RP) that also extend deeply into the renal medulla. Despite the strong correlation between the presence of these plaques and the formation of renal stones, the precise origin and pathogenesis of Randall s plaque formation remain elusive. The discovery of calcifying nanoparticles (CNP) and their detection in many calcifying processes of human tissues has raised hypotheses about their possible involvement in renal stone formation. We collected RP and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Homogenized RP tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed RP samples. Immunohistochemical staining (IHS) was applied on the tissue samples using CNP-specific monoclonal antibody (mAb). Randall s plaques were visible on gross inspection in 11 out of 17 collected samples. Cultures of all serum samples and 13 tissue homogenates had CNP growth within 4 weeks. SEM revealed spherical apatite formations in 14 samples, with calcium and phosphate peaks detected by EDS analysis. IHS was positive in 9 out of 17 samples. A strong link was found between the presence of Randall s plaques and the detection of CNP, also referred to as nanobacteria. These results suggest new insights into the etiology of Randall's plaque formation, and will help us understand the pathogenesis of stone formation. Further studies on this topic may lead us to new approaches on early diagnosis and novel medical therapies of kidney stone formation
Prevalence of Listeria species in camel sausages from retail markets in Aydin province in Turkey and RAPD analysis of Listeria monocytogenes isolates
Samples were taken from 100 camel sausages from the different retail markets in Aydin province in the south-west of Turkey and they were tested for the presence of Listeria spp by biochemical methods. Samples were enriched using Listeria Enrichment Broth and they were inoculated onto Listeria Selective Agar. Listeria monocytogenes was isolated from nine samples (9%), Listeria innocua from 14 samples (14%) and Listeria welshimeri from two samples(2%). A 701 bp fragment of listeriolysin O sequence for L. monocytogenes was amplified using specific primers by polymerase chain reaction (PCR) for confirmation of the identification. A random primer (OPA-11) was used in a random amplified polymorphic DNA (RAPD) assay. This detected five different band profiles amongst the L. monocytogenes isolates, indicating a relatively large amount of genetic heterogeneity amongst the nine isolates. The study has highlighted the need for improved strategies for food safety, in particular appropriate hygienic precautions to avoid contamination of sausage during the manufacturing process and appropriate preservation techniques during storage and transport, to prevent transmission of Listeria spp to consumers at home and abroad
Thermomagnonic spin transfer and Peltier effects in insulating magnets
We study the coupled magnon energy transport and collective magnetization
dynamics in ferromagnets with magnetic textures. By constructing a
phenomenological theory based on irreversible thermodynamics, we describe
motion of domain walls by thermal gradients and generation of heat flows by
magnetization dynamics. From microscopic description based on magnon kinetics,
we estimate the transport coefficients and analyze the feasibility of
energy-related applications in insulating ferromagnets, such as yttrium iron
garnet and europium oxide.Comment: 6 pages, 2 figure
Characterization of Granulations of Calcium and Apatite in Serum as Pleomorphic Mineralo-Protein Complexes and as Precursors of Putative Nanobacteria
Calcium and apatite granulations are demonstrated here to form in both human and
fetal bovine serum in response to the simple addition of either calcium or
phosphate, or a combination of both. These granulations are shown to represent
precipitating complexes of protein and hydroxyapatite (HAP) that display marked
pleomorphism, appearing as round, laminated particles, spindles, and films.
These same complexes can be found in normal untreated serum, albeit at much
lower amounts, and appear to result from the progressive binding of serum
proteins with apatite until reaching saturation, upon which the mineralo-protein
complexes precipitate. Chemically and morphologically, these complexes are
virtually identical to the so-called nanobacteria (NB) implicated in numerous
diseases and considered unusual for their small size, pleomorphism, and the
presence of HAP. Like NB, serum granulations can seed particles upon transfer to
serum-free medium, and their main protein constituents include albumin,
complement components 3 and 4A, fetuin-A, and apolipoproteins A1 and B100, as
well as other calcium and apatite binding proteins found in the serum. However,
these serum mineralo-protein complexes are formed from the direct chemical
binding of inorganic and organic phases, bypassing the need for any biological
processes, including the long cultivation in cell culture conditions deemed
necessary for the demonstration of NB. Thus, these serum granulations may result
from physiologically inherent processes that become amplified with calcium
phosphate loading or when subjected to culturing in medium. They may be viewed
as simple mineralo-protein complexes formed from the deployment of
calcification-inhibitory pathways used by the body to cope with excess calcium
phosphate so as to prevent unwarranted calcification. Rather than representing
novel pathophysiological mechanisms or exotic lifeforms, these results indicate
that the entities described earlier as NB most likely originate from calcium and
apatite binding factors in the serum, presumably calcification inhibitors, that
upon saturation, form seeds for HAP deposition and growth. These calcium
granulations are similar to those found in organisms throughout nature and may
represent the products of more general calcium regulation pathways involved in
the control of calcium storage, retrieval, tissue deposition, and disposal
The effect of Sb substitution of Cu in Bi1.7Pb0.3Sr2Ca2Cu3-xSbxOy superconductors
The effect of partial substitution of Cu in Bi1.7Pb0.3Sr2Ca2Cu3-xSbxOy at x = 0.0, 0.05, 0.1, 0.15, and 0.2 levels on the electrical and structural properties was investigated in this work. X-ray diffraction analysis shows that these materials have a multiphase structure. Two different:types of particles with different morphologies were observed in scanning electron micrographs. The T-c values decreased from 103.5 to 87 K for x = 0.1 Sb substitution level with a subsequent increase to 101K at x = 0.2
Real-time measurement of perceptual qualities in conceptual design
Implications of design decisions are hard to oversee for designers. This is the case in particular with respect to decisions, which influence perception related qualities of designs. Such qualities are for example visual openness, visual privacy, and spatial intimacy. They are difficult to measure because of their subjective and soft nature. Measurements of such qualities are important because they are basis for user-oriented, optimal decisions in architectural and interior design. Existing attempts in the architecture domain to assess such qualities systematically are not based on models of visual space perception. Their ability to assess perception aspects of designs is limited. In this paper a novel real-time measurement system for design is presented, which is based on a computational model of visual space perception. This perception model consists of a vision model and a space cognition model. The vision model is based on retrieval of spatial depth data in scattered form. This process is termed random direction distance sampling (RDDS). The space cognition model consists of sample-wise mapping of depth data to perception data, which is space cognition, and exponential averaging, which is a time-series analysis method, for integration of the perception data to perception information, which is the measurement outcome.Architectural Engineering +TechnologyArchitecture and The Built Environmen
Intelligent Design Support
Design is a complex process that is information and communication intensive. In a design context, the use of knowledge technologies can assist designers in making informed design decisions. This paper reports on an educational experiment that implements an intelligent urban design aid. This experiment facilitates students to do research in a systematic way by using ICKT methods, techniques and tools in order to improve the quality of their urban design. We outline the process, describe the intelligent techniques, discuss the results of the educational experiment, and explore the approachÂ’s potential for real-life design practices
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