Oral and vaginal epithelial cell anti-Candida activity is acid labile and does not require live epithelial cells

BACKGROUND: Candida albicans is the causative agent of oral and vaginal candidiasis. Innate host defenses against C. albicans are important against each infection. Among these are oral and vaginal epithelial cells that have anti-Candida activity. The mechanism of action includes a requirement for cell contact with no role for soluble factors, and a putative role for carbohydrates based on the sensitivity of the activity to periodic acid. METHODS: Periodic acid treatment of epithelial cells as well as the property of partial resistance of antifungal activity to fixation was used to further dissect the mechanism of action. RESULTS: The results herein effectively now challenge a role for carbohydrates alone. Firstly, the putative carbohydrate(s) released into supernatants of periodic acid-treated epithelial cells could not compete with fresh epithelial cells for activity, and equivalent abrogation of activity was observed by periodic acid-treated cells irrespective of the amount of carbohydrate released. Instead, the similar abrogation of activity following treatment with other acids or when cocultured under acidic conditions suggests that the activity is acid-labile. Finally, while activity requires intact epithelial cells, it does not require live cells; activity was minimally affected by fixing epithelial cells prior to coculture where the majority of cells remained impermeable to Trypan blue but were defined as non-viable by positive nuclear staining with propidium iodide. CONCLUSION: These results suggest that antifungal activity is dependent on contact by intact, but not necessarily live, epithelial cells through an acid-labile mechanism.     

Identification of genes preferentially expressed in articular cartilage by suppression subtractive hybridization

Suppression subtractive hybridization is very effective to enrich differentially expressed genes in two different tissues or cells. We therefore used the technique to identify characteristic genes expressed in rat knee joint articular cartilage as compared to rat costal cartilage. In this study, we revealed that several genes were enriched in a subtracted articular cartilage cDNA library. The most enriched gene is lubricin that is a putative key molecule for joint lubrication. The second gene is milk fat globule epidermal growth factor (EGF) factor 8, MFG-E8 whose expression has never been observed in cartilage. Other enriched genes are known to be expressed in cartilage, however their differential expressions in cartilages have not been necessarily common. The preferential expression of characteristic genes in articular cartilage would provide unique properties to the tissue. Our findings will provide a new view of articular cartilage.     

Effects of local nicotinic activation of the superior colliculus on saccades in monkeys

To examine the role of competitive and cooperative neural interactions within the intermediate layer of superior colliculus (SC), we elevated the basal SC neuronal activity by locally injecting a cholinergic agonist nicotine and analyzed its effects on saccade performance. After microinjection, spontaneous saccades were directed toward the movement field of neurons at the injection site (affected area). For visually guided saccades, reaction times were decreased when targets were presented close to the affected area. However, when visual targets were presented remote from the affected area, reaction times were not increased regardless of the rostrocaudal level of the injection sites. The endpoints of visually guided saccades were biased toward the affected area when targets were presented close to the affected area. After this endpoint effect diminished, the trajectories of visually guided saccades remained modestly curved toward the affected area. Compared with the effects on endpoints, the effects on reaction times were more localized to the targets close to the affected area. These results are consistent with a model that saccades are triggered by the activities of neurons within a restricted region, and the endpoints and trajectories of the saccades are determined by the widespread population activity in the SC. However, because increased reaction times were not observed for saccades toward targets remote from the affected area, inhibitory interactions in the SC may not be strong enough to shape the spatial distribution of the low-frequency preparatory activities in the SC.     

Development of a food-frequency questionnaire to measure the dietary calcium intake of adult Japanese women

Assessing calcium intake is necessary for epidemiological studies on osteoporosis. This study was aimed at developing a valid food frequency questionnaire (FFQ) to estimate the dietary calcium intake of Japanese people. The FFQ contains 26 items, representing common sources of calcium. The respondents, 74 women aged 15 - 79 years living in Fukui city, whose dietary calcium intake was estimated at 638 +/- 306 (S.D.) mg based on a one-day weighted food record kept during the National Nutrition Survey of 1996, were asked to indicate their consumption frequency and usual portion size (large, medium, small) for each food item. Trained dieticians interviewed the subjects to confirm their answers to the FFQs. The mean calcium intake per day according to the FFQ (655 +/- 222 mg) did not differ significantly from that according to the one-day food record. The coefficient of correlation between these methods was 0.512, a statistically significant value. The calcium intake from dairy products showed a good correlation, r = 0.717. The coefficient of correlation between the values estimated based on two FFQ filled out three days apart was 0.900, showing good test-retest reliability. Therefore, this FFQ is valid and reliable in estimating dietary calcium intake for epidemiological studies.     

13C enriched carbonate apatites studied by ESR: Comparison with human tooth enamel apatites

Conclusions The present ESR study on the¹³C enriched carbonate apatites suggested that the doublet signal of 146 gauss disposed on either side of the asymmetric signal is a hyperfine splitting due to¹³C. The doublet signal of 170 gauss which has been observed in enamel samples by several workers is tentatively attributed to another hyperfine splitting due to¹³C.