Application of cell culture toxicity tests to the development of implantable biosensors

Cell culture toxicity testing methods were modified and applied to the development of implantable glucose microsensors, and positive and negative control materials suitable for the microsensor assessment were established. The location, source and degree of the toxic effect in a multi-component biosensor was spatially visualized with cell monolayers. A freshly prepared sensor showed moderate toxicity, mainly as a result of the presence of glutaraldehyde and the residual solvents in the polymer layers. However, it was possible to reduce the toxicity by removing the leachable toxic substances through extraction in phosphate, buffer, and a non-toxic sensor was readily obtained.     

Cone penetrometer testing,hydropunch®, and borehole geophysics applications for environmental investigations

An effective groundwater monitoring system can be implemented by the combined utilization of cone penetrometer (CPT), HydroPunch^® sampling, and borehole geophysical methods. The combined techniques provide a cost‐effective method for the design of a groundwater monitoring system for geologists or hydrogeologists assessing a site. With the relatively high costs associated with determining groundwater quality for site assessments, coupled with regulatory agency compliance, these combined methods can provide an effective edge in an increasingly competitive environmental industry. CPT combined with HydroPunch sampling can delineate the horizontal and vertical extent and concentration of a contaminant plume, define the extent and thickness of a free product plume, define soil and aquifer characteristics, and aid in the proper selection of well location and screen placement. The use of borehole geophysics further enhances the interpretation provided from the CPT. The interpretation of borehole geophysics provides additional information about the deposition regime of the area of investigation and a more detailed investigation of the stratigraphy. The CPT and HydroPunch can be used in unconsolidated sediments, and HydroPunch sampling can be combined with a hollow‐stem auger system. Borehole geophysics can be run in almost any environment. CPT and borehole geophysics provide information on specific lithologic characteristics necessary to obtain a groundwater sample from vertically separated aquifers. The HydroPunch can obtain a discrete, chemically representative groundwater sample from the targeted aquifer. CPT and borehole geophysics can also be used to determine lithology and for correlation of equivalent stratas from one borehole or well to the next. Borehole geophysical interpretation also provides a means of determining not only the stratigraphy and lithology but also the aquifer parameters and the type of fluids in the aquifer. Hydrogeologic and geologic data obtained from using these three methods can be employed to maximize the cost‐effectiveness and design efficiency of a groundwater monitoring system. Proper location of wells and screened interval placements are determined by a coherent design process rather than by random chance. Two studies demonstrating the combined applications of CPT, HydroPunch, and borehole geophysics for the design and placement of groundwater monitoring wells are presented in the following discussion.     

Application of enzyme-linked immunosorbent assay for mass examination of strongyloidiasis in okinawa, Japan

The enzyme-linked immunosorbent assay was tested to evaluate whether it could be applicable in screening for mass examination of strongyloidiasis. A total of 2906 inhabitants in three areas (858 in Gushikawa Village, 849 in Nakazato Village and 1199 in Sashiki Town) were screened by the enzymatic assay and approximately 11–30% (11.8% in Gushikawa, 17.0% in Nakazato and 27.7% in Sashiki) were considered to be antibody positive. In the parasitological follow-up examinations of those who were antibody positive, actual infection was found in more than half (51%) the subjects. The overall infection rates estimated from the results reached 5.8% in Gushikawa, 9.1% in Nakazato and 14.0% in Sashiki (mean = 10.4%). The infection rates were significantly higher than those in previous surveys conducted in the same areas. The ELISA technique was found to be useful for strongyloidiasis screening and for seroepidemiological purposes in Okinawa.     

Schistosoma japonicum: Immediate hypersensitivity reactions to egg antigen in humans and rodents

Immediate hypersensitivity reactions in schistosoma japonicum infections were examined in both man and experimental animals. In man higher reaction to soluble egg antigen than to adult worm antigen was detected by the use of the radioallergosorbent test (RAST). Blood-collecting filter paper can be used in RAST for seroepidemiological study in place of a skin test. Reaginic antibody formation against egg antigen was detected at the approximate time of egg deposition in strains of mice, Mongolian gerbils, cotton rats, and laboratory rats by the use of passive cutaneous anaphylaxis or Prausnitz-Küstner-type skin tests. At the same time circumoval precipitin tests were positive. Results with athymic nude mice suggest that these reactions are T-cell dependent. No detectable reagin synthesis against adult worm antigen was found in the animals so far examined, confirming stronger allergenic reaction to egg antigen than to that of adult worms in S. japonicum infections in man and animals.     

Epistatic,additive and dominance variation in a triple test cross of bread wheat (Triticum aestivum L.)

Summary Triple test cross progenies resulting from the crossing of three testers (Kloka, UP 368 and an f₁ intermediate between them) and 24 varieties of bread wheat have been studied for plant height (cm), peduncle length (cm), ear length (cm), number of spikelets per spike and harvest index (ratio between economic and total yield). Epistasis was not significant for any of the characters studied. The testers were inadequate for plant height and for peduncle length although the testers varied considerably for these traits. Additive variance played a significant role in the inheritance of all the characters except number of spikelets per spike. The dominance variance was important for plant height, ear length and harvest index. The degree of dominance was in the over-dominance range for plant height. Complete dominance was operative for ear length, number of spikelets per spike and harvest index whereas for peduncle length only partial dominance was observed. The possibility of the isolation of the recombinants with high harvest index has been stressed.     

The antimutagenic effect of selenium on 7,12-dimethylbenz(a)anthracene and metabolites in the amesSalmonella/microsome system

The antimutagenic effect of selenium as sodium selenite, sodium selenate, selenium dioxide, and seleno-methionine was studied in the AmesSalmonella/microsome mutagenicity test using 7,12-dimethylbenz(a)anthracene (DMBA) and some of its metabolites. Selenium (20 ppm) as sodium selenite reduced the number of histidine revertants on plates containing up to 100 μg DMBA/plate. Increasing concentrations of selenium as sodium selenite, sodium selenate, and selenium dioxide up to 40 ppm Se progressively decreased the number of revertants caused by 50 μg DMBA. DMBA and its metabolites 7-hydroxymethyl-12-methylbenz(a)anthracene, 12-hydroxymethyl-7-methylbenz(a)anthracene, and 3-hydroxy-7,12-dimethylbenz(a)anthracene were mutagenic forSalmonella typhimurium TA100 in the presence of an S-9 mixture. Selenium supplementation as Na₂SeO₃ reduced the number of revertants induced by these metabolites to background levels. The antimutagenic effect of inorganic selenium compounds cannot be explained by toxicity of selenium as determined by viability tests withSalmonella typhimurium TA100. Selenium supplementation in all forms examined, except sodium selenate, decreased the rate of spontaneous reversion. Selenium as sodium selenate was slightly mutagenic at concentrations of 4 ppm or less. Higher concentration of Na₂SeO₄ inhibited the mutagenicity of DMBA. The present studies support the anticarcinogenic potential of selenium and indicate that form and concentration are important factors in this trace element's efficacy.     

Seroimmunological and parasitological surveys of leucocytozoon caulleryi infection in chickens in several asian countries

Epizootiological surveys of Leucocytozoon caulleryi infection in chickens in Japan, Taiwan, Philippines, Singapore, Malaysia and Thailand were undertaken by means of the immunodiffusion test. The rate of infection of L. caulleryi confirmed by the examination of parasites in the peripheral blood of chickens coincided with that of positive antibody response in the immunodiffusion test. Antibodies against L. caulleryi were found in chickens in all the countries surveyed in the present investigation. The prevalence of L. caulleryi infection in chickens was confirmed by the immunodiffusion test. Several chickens in each country showed the presence of serum antigens of L. caulleryi at the times of serum sample collection. These results seemed to indicate that the immunodiffusion test is a method efficient enough to be applicable to the epizootiological surveys and diagnosis of L. caulleryi infection in chickens in the field. As a result, the antibodies or soluble antigens in the sera of chickens infected with L. caulleryi present, respectively, in each country may have the same immunological characters.