The antibacterial activity of photocatalytic titanium dioxide (TiO 2 ) thin films with photodeposited silver on the surface of sanitary ware was studied. Samples were prepared by coating a TiO 2 sol that was calcined at 8801-9801C and photodeposited with silver ions onto the glazed layer of the sanitary ware. The relationships between the antibacterial activity and the fabrication conditions were investigated by X-ray diffractometry, scanning electron microscopy, and colorimetry. The phase of TiO 2 identified in the thin films was a mixture of anatase and rutile. The amount of rutile phase increased as the calcination temperature increased, and grain growth of the TiO 2 particles was observed. The activity was dependent on the TiO 2 thickness, the calcination temperature, and the amount of silver. These results suggest that the antibacterial activity was strongly affected by the amount of anatase in the thin films. 9801C for 1 h in a muffle furnace (Model FP-31, Yamato Science Company, Ltd., Tokyo, Japan). Sample tiles with a TiO 2 thin-film coating on the glaze were obtained.
95J ournal
The staphylococcal Panton-Valentine leukocidin (PVL) genes [lukS-PV-lukF-PV] existed in a hexagonal phage-like particle (phi PVL) isolated from mitomycin C-induced Staphylococcus aureus V8 (ATCC 49775). The genome packed in phi PVL was a linear double-stranded 40-kb DNA with single-stranded cohesive ends (cos). The [lukS-PV-lukS-PV], attP, and int (integrase gene) of phi PVL were all located very close to one another within a 4.0 kb-segment on the genome in the order given, and the segment is located at the center from the left and the right cos sites. In addition, the [lukS-PV-lukF-PV]-attP-int region contains 5 direct repeat sequences that show high similarity with the recombinase-binding sites of bacteriophages of S. aureus.
The amounts of volatile substances responsible for the malodor of human waste (feces and urine) obtained from the storage tank of a community waste-water treatment plant were determined. Thus far, there has been little systematic research on malodor-causing substances of human waste. These substances were collected using Tenax-TA, and their concentrations were determined by the usual thermal-desorption coldtrap injector/gas chromatography/mass spectrometry (TCT/GC/MS). About 90% of the malodor-causing substances were fatty acids: acetic acid, propionic acid and butyric acid. The proportion of ammonia was 6.5%. Other malodor-causing and minor substances detected were indole, skatole, pyridine, pyrrole, hydrogen sulfide, and methyl mercaptan. In addition, a small amount of paradichlorobenzene used as a deodorizer in household toilets was also recognized.
Various malodorous substances generated from human feces were analyzed immediately after the use of a Western-style toilet by 50 subjects. The types and amounts of these malodorous components varied slightly between individuals, depending on the food that they had eaten and their state of health. Hydrogen sulfide was detected at concentrations of 5-26 ppb, methyl mercaptan at 2-15 ppb, ammonia at less than 100 ppb, propylaldehyde, fatty acids, and pyridine at about 10 ppb, and trimethylamine at around trace levels. When subjects had diarrhea, the amounts of fatty acids, particularly acetic acid, in feces were more than 100000-fold higher than in feces of those in normal health.
A combinatorial immunoglobulin gene library was constructed from lymphocytes in peripheral blood of a patient with toxoplasmosis and screened for production of human monoclonal antibody Fab fragments to recombinant surface antigen 1 (SAG1) of Toxoplasma gondii. Two Fab clones, Tox203 and Tox1403, which consisted of a common heavy chain and different light chains, showed positive staining on the entire surface of tachyzoites in confocal microscopy. Sequence analysis of the heavy-chain gene revealed that the closest germ line V segments were VH3-23. The germ line D segment was D1-7, and the closest germ line J segment was JH4. In the light-chain genes, the closest germ line V segment was V1-17 with the J1 or J4 segments. The dissociation constants of these Fab fragments with recombinant SAG1 were 3.09 ؋ 10 ؊9 M for Tox203 and 2.01 ؋ 10 ؊8 M for Tox1403, indicating that the affinity of Tox203 was 7 times higher than that of Tox1403. Preincubation of T. gondii tachyzoites with Tox203 significantly inhibited their attachment to cultured MDBK cells. Passive immunization of mice with Tox203 also significantly reduced mortality after challenge with T. gondii tachyzoites. This is the first report of bacterial expression of human monoclonal antibody Fab fragments to SAG1 of T. gondii. These results also demonstrate that human Fab fragments to SAG1 might be applicable for immunoprophylaxis of toxoplasmosis.Toxoplasma gondii is an obligate intracellular parasite in the phylum Apicomplexa and infects a variety of warm-blooded domestic and wild animals worldwide. It is an important foodborne parasite transmitted primarily from animals to humans through meat, as well as through oocysts shed by cats into the environment (25). Infection in humans is usually asymptomatic in immunocompetent hosts. However, primary infection during pregnancy can result in severe neonatal malformations and ocular complications in the fetus. In immunocompromised hosts such as patients with human immunodeficiency virus/ AIDS, reactivation of the latent infection results in symptomatic diseases such as toxoplasmic encephalitis (14,22). Transmission of T. gondii by organ transplantation from a seropositive donor to a seronegative recipient is also an important potential cause of disease in heart, heart-lung, kidney, liver, and liver-pancreas transplant patients (25).The surface of T. gondii is the first component to contact the host cells. The T. gondii surface is coated by closely related antigens that belong to the surface antigen 1 (SAG1)-related sequences (SRS) superfamily (13, 16). SAG1 is the most abundant and immunogenic of these antigens and is important for the process of invasion. Treatment of T. gondii with mouse monoclonal or rabbit polyclonal antibodies to SAG1 inhibits parasite attachment to host cells (24). Fab fragments derived from a mouse monoclonal antibody also showed dose-dependent inhibition of parasite attachment (23). Therefore, human monoclonal antibodies to SAG1 may be applicable for prevention of transmission and reactivation ...
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