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A helminthological survey of the intestinal parasites in stray dogs was conducted in urban and suburban area of Tacuarembó, Uruguay, during winter time. Eighty stray dogs captured in the city were necropsied. Seventy nine dogs (98.8 %) were positive for helminth infection. Seventy seven (96.3 %) were parasitized by hookworms. Two species of hookworms were found: Ancylostoma caninum96.3 % and A. braziliense49.4 %. This is the first report of the prevalence of A. braziliensein Uruguay. Considering that incidences of human cutaneous larva migrans caused by the migration of hookworms larvae were restricted mainly to the northen part of Uruguay and that only A. caninumwere reported to be prevalent in the southen part, it is supposed that A. brazilienseis the primary causative agent of human cutaneous larva migrans in Uruguay.

Organically functionalized mesoporous silica films have been prepared by a novel synthetic procedure that involves spin-coating of mesostructured silica films and a vapor infiltration (VI) technique, using organosiloxanes, before the removal of surfactant. The VI-treated mesostructured films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and a field emission scanning electron microscope (FE-SEM). Nitrogen adsorption/desorption measurements were performed using films attached with a silicon substrate. The XRD and FE-SEM measurements show that the mesochannel wall, densified and modified with organosilyl groups by the VI treatment, hardly contracts under calcination. FE-SEM observations for the films' cross section support the view that organosiloxane vapor is not deposited on the surface of the film. These results show that organosiloxane molecules penetrate the film and are selectively incorporated into the silica wall. Thus, hydrophobic mesoporous silica films can be synthesized without a reduction in pore size, a result that cannot be attained by conventional grafting and co-condensation methods. The excellent high porosity and hydrophobicity of the mesostructured composite films may be of advantage for next-generation low-k dielectric films.

Nano-phase transition of an organic−inorganic nanocomposite under vapor infiltration of tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS) was found in mesoporous thin film preparation. The rearrangement into a hexagonal periodic structure implies high mobility of the surfactant−silicate composites in solid phase. The swelling of film thickness and d spacing was observed under vapor infiltration. The nano-phase transition under vapor infiltration contains two competitive processes:  (1) the penetration of TEOS or TMOS into the film and (2) the reaction of the silanol group. Film thickness and d spacing were controlled by changing synthetic temperature, silica sources (TEOS and TMOS), catalysts (HCl and NH3), and the thickness of surfactant films. The films prepared from vapor phase show superior characteristics, such as high structural stability and high resistance to water adsorption. The vapor infiltration method is a simpler process than conventional sol−gel techniques and attractive for mass production of a variety of organic−inorganic composite materials and inorganic porous films.

A mesoporous silica film was prepared on a silicon substrate using a spin-coating process followed by a tetraethyl orthosilicate (TEOS) vapor treatment. The TEOS-treated mesostructured silica film did not contract during calcination, showing high structural stability. Thermal treatment without TEOS vapor was not effective to enhance the structural stability of mesostructured films. A flat mesoporous silica film about 250 nm thick was grown from the silicon substrate. No silica particle was deposited from TEOS vapor on the surface of the film, suggesting the penetration of TEOS vapor into the film. A periodic porous structure was observed in the FE-SEM image of the cross section of the mesostructured film. This indicates that the channels run predominantly parallel to the surface of the silicon substrate. FTIR studies suggested that the silanol groups in the film significantly decreased after the TEOS treatment. TEOS molecules penetrate into an originally deposited silicate film and react with the silanol groups. The densified silica wall has high structural stability and hardly contracts under a calcination process. The developed TEOS-treated mesoporous silica film is a promising material such as chemical sensors, low-k films, and other optoelectronic devices.

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

The expanding distribution of alveolar echinococcosis in Hokkaido, Japan necessitates a search for control measures, particularly for killing Echinococcuseggs; and UV radiation is a potential tool. To determine the effective UV lamp and its optimum duration of exposure to inhibit the infectivity of taeniid eggs, three UV lamps (UVA, UVB and UVC) with peak emissions at different wavelengths were used to irradiate eggs of Taenia taeniaeformis. Irradiation was done in durations of 30, 90, 270, 810, 2,430 and 7,290 s. Infectivity of the irradiated eggs was tested by oral inoculation into rats. The inhibitory effect of the UV lamps at different exposure durations was determined by the reduction in the larval cyst establishment and by the delay of larval development. The UVC lamp (narrow peak at 254 nm) was found to be the most effective lamp at an exposure duration of more than 2,430 s (2,430 mJ/cm2), attaining 100% reduction. Also, shorter exposure durations produced a significant effect on the development of irradiated eggs in a greater percentage of small cysts (>1 mm) among the metacestodes. Irradiation delayed the development of some cysts, as observed in histopathological sections. UVA and UVB lamps were not able to attain 100% reduction. It is concluded that the UVC lamp can be used as a tool in sterilizing taeniid eggs and is thus a promising method to control echinococcosis, although it may require a higher intensity of exposure.

In order to assess the infection risk of alveolar echinococcosis among urban residents of Sapporo, the capital of Hokkaido, Japan, a survey was conducted on fox distribution in the urban area and on the prevalence of Echinococcus multilocularis among the foxes. The fox distribution, evaluated from fox footprints left on the snow in parks and woodlands, and from locations of fox carcasses recorded by the Sapporo municipality, was concentrated along the border of the urban area and in the southwestern part of the city, facing the mountain. Fox faeces were collected around active fox dens, and analysed by a coproantigen detection assay and parasite egg examination for the Echinococcus infection. Thirty-three out of 155 faeces were coproantigen positive. Coproantigen-positive faeces were collected from 11 den sites (57·9% of total den sites), and all except 1 were located in the urban fringe. A high intensity of taeniid eggs (>100 eggs per 0·5 g) containing faeces were also collected in the 3 sites of them. Although Echinococcus infection in rodents was not observed from the necropsy of 23 rodents captured around active fox dens, arvicolid rodents, a suitable intermediate host for E. multilocularis, were captured in the urban fringe. Therefore, the urban fringe offers suitable conditions in which the life-cycle of E. multilocularis could be maintained. Prompt measures to control echinococcus infection should be taken, even in urban areas.

Abstract Background The low attenuation areas on computed tomographic (CT) scans have been reported to represent emphysematous changes of the lung. However, the regional distribution of emphysema between the inner and outer segments of the lung has not been adequately studied. In this study the regional distribution of low attenuation areas has been compared by quantitative CT analysis and the contribution of the regional distribution to pulmonary function tests evaluated in patients with chronic obstructive pulmonary disease (COPD). Methods Chest CT images and the results of pulmonary function tests were obtained from 73 patients with COPD. The lung images were divided into inner and outer segments in the upper (cranial), middle, and lower (caudal) sections. The percentage ratio of low attenuation area to corresponding lung area (LAA%) was then calculated. The LAA% of each segment was also compared with the results of pulmonary function tests. Results The mean (SD) LAA% of the inner segment was 39.1 (18.5) compared with 28.1 (13.2) for the outer segment (p<0.0001). Linear and multiple regression analyses revealed that airflow limitation is closely correlated with the inner segment LAA% of the lower lung. In contrast, the carbon monoxide transfer factor is closely correlated with the inner segment LAA% of the upper lung. Conclusion Low attenuation areas on CT scans are more often found in the inner segment of the lung than in the outer segment, and the contribution of the inner segment to pulmonary function tests may be greater than the outer segment.

Octanol-induced changes in the kinetics of glycinergic inhibitory postsynaptic currents (IPSCs) were investigated by whole-cell recording from hypoglossal motoneurons in mouse brainstem slices. Octanol (1 mM) prolonged the decay time constants (_decay) of stimulus-evoked IPSCs (e-IPSCs) by 20267% (SE). The depression of e-IPSC amplitudes was dose-dependent with an EC₅₀ of 475 µM. Octanol also reduced the amplitude and prolonged the decay time constant of glycinergic currents evoked by local pressure ejection of glycine (I_gly). Replacement of extracellular Na⁺ by choline and application of the specific glycine transporter GLYT1 inhibitor, sarcosine, lengthened _decay of I_gly, but did not change the decay time constants of e-IPSCs. Intracellular acidification by the weak organic acid salt sodium propionate (30 mM) reduced the e-IPSC amplitude by 229% and prolonged by 186%. Sodium propionate also prolonged the decay time constants of I_gly by 2811%. The observed effects on decay kinetics were much smaller than those caused by octanol. The data show that octanol prolongs the decay time course of glycinergic synaptic currents by mechanisms independent of glycine uptake or intracellular acidification. We conclude that the effects were most probably due to direct action on postsynaptic glycine receptors.

Following the oral administration of metacestodes of two isolates ofTaenia crassiceps, the enteral establishment and survival of the strobilar stage were examined in golden hamsters (Mesocricetus auratus), Mongolian gerbils (Meriones unguiculatus) and laboratory mice. The origin of the isolates wasMicrotus montebelli caught in Japan in 1985 orClethrionomys rutilus captured on St. Lawrence Island, Bering Sea, in 1988 (abbreviated as JPN and SLI isolates), respectively. The enteral establishment of the SLI isolate was distinctly higher than that of the JPN isolate in golden hamsters and mice, whereas the difference was marginal in Mongolian gerbils. All initially-established parasites survived to become gravid adults in prednisolone-treated golden hamsters and Mongolian gerbils; the average recovery of cestodes of the SLI and JPN isolates were 55.8%–76.7% vs 11.7%–35.0% in the former and 28.0%–52.7% vs 25.8%–32.2% in the latter. The distinctly higher level of enteral establishment of the SLI isolate in golden hamsters makes available a model for quantitative studies on parasite-host relationships in experimental taeniasis.

Higher infection rates were observed in gerbils and voles than in ICR mice after oral inoculation with eggs of a Japanese isolate ofTaenia crassiceps. Asexual reproduction ofT. crassiceps cysticerci was observed in all gerbils and voles infected i.p. with the cysticerci. However, ICR mice and Wistar rats were not suitable for the asexual proliferation ofT. crassiceps. The hooks of cysticerci from mice were smaller than those from gerbils. In experimentally infected puppies, parasite development was noted as follows: strobilation and initial differentiation of the genital primordia on day 7 postinoculation (p.i.), appearance of the testes on day 9, observation of the ovaries on day 10, and development of the lateral branches of the uterus on day 15. The prepatent period was 27–31 days. After day 15 p.i., most of the worms were recovered from the middle third of the small intestine. The number of proglottids shed per day by each strobila was about 1. The number of eggs contained in a gravid segment was about 13000.