Efficiency of Extraction of Nematodes by Flotation-Sieving Using Molasses and Sugar and by Elutriation

Blackstrap molasses was studied as an economical substitute for sucrose in the preparation of an extracting solution for removal of nematodes from soil by the flotation-sieving technique. The maximal number of nematodes extracted from soil was obtained with molasses solutions with specific gravity values in the range 1.000-1.073. Results of studies on the relation between size of soil sample and the amount of extracting solution are presented. In paired comparisons, a molasses solution with sp. gr. = 1.100 at 27 C extracted greater numbers of plant parasitic, dorylaimoid, mononchoid, and other soil nematodes than did the standard 1.0 M sucrose solution (sp. gr. = 1.100); the superiority of the molasses solution is attributed to its higher viscosity. The molasses method also was superior or equal in efficiency to the elutriation technique.     

Cytophotometric studies of cell populations

Technologic advances in the recording of digitized imagery have made the study of large cell populations by image analytical methods feasible. Computed image information provides quantitative, and novel, information that allows an exact measurement of minute changes in the chromatin distribution of cell nuclei, and the detection of subpopulations of cells or changes in the functional state of the cells. The sensitivity of the detection exceeds that of human observers; the specificity of the measured changes must be the subject of basic cell biologic research.     

Towards a suitable antigen for diagnosis of Gnathostoma spinigerum infection.

, , , and 1992. Towards a suitable antigen for diagnosis of Gnathostoma spinigerum infection. International Journal for Parasitology 22: 1151–1156. Advanced third-stage larvae of G. spinigerum were obtained from two separate sources, namely from cysts in the livers of naturally infected eels (L3E) and from experimentally infected mice (L3M). Morphology of the L3E was studied microscopically. The larvae were homogenized in distilled water, 1% Triton X-100 or 1% sodium deoxycholate containing protease inhibitors. Protein compositions of the three crude extracts were compared, on the same weight basis, by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie brilliant blue staining while their antigenicities were studied by Western blot analysis using serum of a patient with parasitologically confirmed gnathostomiasis. Distilled water was found to be the best extraction solution in solubilizing proteins especially the diagnostic antigen, namely the 24,000 (24 kDa) mol. wt component from the larvae. The L3E and L3M contained relatively equal amounts of the 24 kDa antigen. This diagnostic component was anatomically located in the body fluid, oesophagus and intestine of the larva.     

Age determination of Aedes cantans using the ovarian oil injection technique

A study of the age structure of a population of adult female Aedes cantans Meigen was undertaken using the ovarian oil injection technique to determine parity. Results showed that, contrary to popular opinion, ovariolar sacs do not form gonotrophic dilatations and cannot be used for physiological age determination. Dilatations were formed only by follicles which degenerate at a very early stage in the gonotrophic cycle. The proportion which consistently do degenerate (the gonotrophic diagnostic index) decreases in each successive cycle. Results showed that the mean age of the population during the study was 2.04 parous, which was one gonotrophic cycle less than expected, possibly due to scarcity of hosts in the area.     

Genetic relationships among five nemipterid fish species from the Indian coast using allozyme analysis

Based on Nei's genetic distance Nemipterus peronii and Nemipterus japonicus showed a greater affinity to Parascolopsis aspinosa than to the other Nemipterus species studied. Significant differences between the Indian west and east coast samples of N. japonicus were detected. Polymorphic (P<0.95) and diagnostic loci suitable for stock delineation and species identification were observed.