Pasteuria sp. Parasitizing Trophonema okamotoi in Florida

Two populations of Trophonema okamotoi parasitized by Pasteuria sp. were found on Liquidambar styraciflua (sweetgum) and on an unidentified tropical grass in north-central Florida. Endospores of this Pasteuria sp. attached to motile vermiform second-stage juveniles (J2) and males of T. okamotoi, but not to other developmental stages. Sporangia and new endospores were produced only inside the bodies of swollen and sedentary third- and fourth-stage juveniles and females that developed in the host roots. No egg masses were produced by infected T. okamotoi females. The endospore diameter from the tropical grass population was 4.93 μm and the central core diameter was 1.97 μm; measurements of endospores from the sweetgum populations were similar. Endospores that were collected from T. okamotoi and added to uninfected T. okamotoi and other plant-parasitic nematodes attached/to J2 of T. okamotoi but did not attach to juveniles and adults of Helicotylenchus pseudorotrustus, Pratylenchus brachyurus, or to J2 of either Meloidogyne arenaria race 1, M. incognita race 1, M. javanica, or Tylenchulus semipenetrans. Pasteuria sp. from T. okamotoi differed from the described Pasteuria species in endospore size, host preference, and rate of attachment.     

Primary cultures and the levels of cytochromeP450 in hepatocytes from mouse,rat, hamster,and rabbit liver

Summary Hepatocyte primary cultures (HPC) derived from rat, mouse, hamster, and rabbit liver were characterized for a variety of parameters. The conditions that maximized recovery, attachment, and survival varied between species. Hepatocytes from all four species were capable of attaching in serum-free Williams’ medium E (WME), but optimal attachment as monolayer cultures was achieved for mouse and hamster HPC in medium receiving 1% calf serum supplementation. Hamster hepatocytes required additional cations, whereas rabbit and rat hepatocytes displayed maximal attachment in medium supplemented with 10% calf serum. Survival of mouse and rabbit hepatocytes after 24 h in serum supplemented media was in the order of 90%. Rat and hamster hepatocyte 24 h survival was approximately 70 and 60%, respectively, and was not significantly affected by serum supplementation. Hepatocytes from each species varied in their content of cytochromeP450 at the time of isolation and in the rate of reduction during culture. Mouse and rat hepatocytes demonstrated the most rapid decline in content during the initial 24 h in culture, whereas concentrations in rabbit hepatocytes were virtually unchanged. The rate of decline inP450 concentrations in hamster hepatocytes was intermediate between those displayed by rat and rabbit hepatocytes. These studies have delineated conditions useful for the culture of hepatocytes from four species and have documented the status of an important parameter of their functional capability. This study was supported by EPA contract 68-01-6179. C. J. Maslansky was a recipient of a Monsanto Fund Fellowship in Toxicology.     

Binding of epithelial cells to lectin-coated surfaces

Summary Epithelial cells may relate to their basement membrane substrates via lectin-like interactions. In a model system for study of this type of interaction, lectin-coated bacteriological plastic petri dishes were presented as substrates for epithelial cell adhesion. Of 21 lectins tested by mixed agglutination against two epithelial cell types, Madin-Darby canine kidney (MDCK), and human embryonic kidney cells (HEK), nine gave less than 5% rosettes and 12 gave 5 to 50% rosettes. Wheat germ agglutinin (WGA) andGeodia cydonium lectin gave the highest percentage of rosettes. Wheat germ agglutinin was readily adsorbed to plastic surfaces and maintained specificity in binding interactions. Both MDCK and HEK cells attached as well to WGA coated petri dishes as to conventional tissue culture dishes. Furthermore, both spread over the lectin-coated surfaces. The MDCK cells grew to confluence and could be subcultured and maintained indefinitely on such surfaces, although WGA in solution was toxic to the cells in concentrations as low as 0.1 to 1.0 μg/ml. Cell attachment to WGA coated dishes was blocked by cycloheximide only if the cells had been preincubated with the inhibitor for several hours. Cell attachment was not inhibited by pretreatment of cells with neuraminidase. Precoating cells with WGA blocked binding to both WGA-coated surfaces and untreated tissue culture dishes. Cells attached to WGA-coated dishes could not be readily dislodged by trypsin-EDTA for the first 2 h after subculture. By 4 h, attachment was again trypsin sensitive, suggesting that the cells synthesized a trypsin-sensitive material that was laid down between the cell surface and the WGA-coated dish. Regeneration of trypsin sensitivity was not blocked by cycloheximide. This work was supported by Research Grant AG01986 from the National Institutes of Health, Bethesda, Maryland.     

Attachment and Short-Term Maintenance of Motility and Viability of Entamoeba Histolytica In A Defined Medium*

Organic requirements for attachment to glass, elongation, and motility of Entamoeba histolytica, have been determined. the trophozoite, which has been grown axenically only in highly complex media with reduced oxygen tensions, remains rounded and detached when placed in a Tris-HCl buffered solution containing NaCI, KCI, MgCI₂, and CaCI₂. A maintenance medium in which the amebae could attach to glass, elongate, and remain motile and viable for 12 to 24 h was devised with the addition of cysteine, ascorbic acid, bovine serum albumin, and the vitamin solution of medium NCTC #107. Tris-HCI was the most effective buffer tested and the optimal pH was 6.9 to 7.0. Survival, but not attachment, of the amebae was decreased at osmolalities ranging between 110 and 180 milliosmoles/kg, whereas both functions were decreased above ～260 milliosmoles/kg. Bovine serum albumin, the most effective of the proteins tested, and the vitamin solution helped maintain attachment of some ameba strains, but were not required by other strains. the requirements for cysteine and ascorbic acid were absolute and highly specific. During incubation in the maintenance medium, cell volumes decreased. Sensitivity of the organisms to agglutination by concanavalin A, wheat germ agglutinin, soybean agglutinin and fucose binding protein remained unchanged.     

Abstracts

ABSTRACT

The normal development of empathy has been proposed to be imperative to the healthy emotional and social functioning of youths. In contrast, compromised levels of empathy have been linked to an increased propensity to engage in antisocial behaviors, including animal cruelty. Previous findings have revealed parent attachment to be intrinsically linked to the development of empathy. This association has been shown to play a role in predicting the expression of various outcome behaviors, including both those which are prosocial in nature, and those which are antisocial, and potentially aggressive. This study examines these associations in a sample of 281 12- to 18-year-old students. The aims included the investigation of the direct predictive roles played by attachment and empathy for prosocial and antisocial behaviors directed at both humans and animals. We also investigated the mediating role played by empathy in these relationships. Attachment and empathy significantly predicted prosocial and antisocial behaviors, both individually, and in combination. Furthermore, empathy was found to serve a mediating role in the associations between attachment and: human-directed prosocial behavior, the humane treatment of animals, and animal cruelty. These findings expand upon existing literature by demonstrating that it is, at least partially, through empathy that attachment to parents predicts prosocial and antisocial behaviors during adolescence. This is in contrast to the direction of relationships implied by some previous findings and proposals, which have suggested that treating animals humanely fosters the normal development of empathy, for example. Notwithstanding the promising findings revealed by the current study, we recommend that replicating this research using a larger sample will assist in addressing the limited generalizability identified in the current study. It is further proposed that the use of a lie scale could limit the influence of social desirability responding. Future research is also needed to determine the direction of the demonstrated relationships.     

Association of age with class VI composite restoration

Dental caries is the major oral health problem in most of the countries, affecting 60-90% of school children and a vast majority of adults. Therefore, it is of interest to evaluate the association of age with Class VI defects restored with composite restorations. We used 102 cases with data regarding Class VI composite restorations in a datasheet of 86,000 records at Saveetha Dental College, India for this study. Data shows that Class VI restorations were commonly seen in upper anterior teeth in the age group of 51 and above. The cavities prepared to receive Class VI restoration followed a conservative design of caries removal and used direct restoration techniques for reconstruction of the lost tooth structure.     

Species specificity and sexual dimorphism in tooth shape among the three sympatric haplochromine species in Lake Kivu cichlids

Tooth shape is used to differentiate between morphologically similar species of vertebrates, including fish. This study aimed to quantify tooth shape of three sympatric species: Haplochromis kamiranzovu, H. insidiae, and H. astatodon endemic to Lake Kivu, whose existing identification criteria are currently only qualitative. A quantitative tooth shape analysis was performed based on digitized tooth outline data with a subsequent elliptic Fourier analysis to test for differences among the three species. We looked at crown shape and size differences within H. kamiranzovu and H. insidiae at geographical, habitat, and gender levels. No comparison at habitat level was done for H. astatodon because it is found only in littoral zone. The analysis revealed significant tooth shape differences among the three species. Haplochromis astatodon had a significantly longer major cusp height and a longer and larger minor cusp than that of H. insidiae. It had also a longer major cusp height and a longer and larger minor cusp than that of H. kamiranzovu. Tooth shape differences of H. kamiranzovu and H. insidiae species were not significantly different between littoral and pelagic fish (p > .05) while differences were significant between southern and northern Lake Kivu populations (p < .05). Tooth sizes in H. kamiranzovu and H. insidiae were significantly different, both in height and width as well as in their ratios, and this was true at sex and geographic levels (p < .05), but not at habitat level (p > .05). Tooth shape was also significantly different with sharp teeth for males compared with females of southern populations versus northern ones. These shape‐ and size‐related differences between sexes suggest differences in the foraging strategies toward available food resources in the lake habitat. Further research should explain the genetic basis of the observed pattern.