Grit blasted aggregates of hydroxyl apatite functionalized calcium carbonate in occluding dentinal tubules.

OBJECTIVES: This study aimed to investigate the effects of using hydroxyl apatite functionalized calcium carbonate (FCC) particles on occluding dentinal tubules. METHODS: Dentine specimens extracted from eighteen human molars with exposed dentinal tubules were divided into three groups (n = 6/group): a) Cut surface with smear layer; b) EDTA (smear layer removed with 17% EDTA for 1 min); and c) Grit blasted functionalized calcium carbonate (FCC) with and air pressure of 280 kPa. Microscopic dentinal tubule occlusion, tubule diameter and tubule area were evaluated using scanning electron microscopy (SEM) before and after grit blasting. Biomineralization of specimens was carried out in a simulated body fluid (SBF). Elemental analysis of occluding materials was carried out using energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction (XRD) analysis was performed to demonstrate the crystal structure of the biomineralized layer on dentine. RESULTS: FCC particles showed penetration into the dentinal tubules by breakage of their original particle shape and size. EDTA treated surface had higher number and larger size tubules than those with smear layer or grit blasted (p < 0.005). SEM-EDX analysis revealed mineral precipitation of calcium phosphate on the SBF immersed dentin specimens. XRD analysis showed typical crystal structure of hydroxyl apatite for the biomineralized surface layer on dentine. CONCLUSIONS: Grit blasted FCC particles initially occluded effectively the opened dentinal tubules and biomineralization occurred in tubules primarily occluded by the FCC particles. However, in the optimal in vitro conditions in SBF, no difference between biomineralization was found between the grit blasted surface and the control surface. CLINICAL SIGNIFICANCE: Several materials and methods have been established for treatment of dentinal hypersensitivity although a golden standard treatment has not been discovered. Grit blasted functionalized calcium carbonate has a potential to occlude and remineralize exposed dentinal tubules. This could offer a more biological approach on treatment of dentin hypersensitivity.

Parallel genetic and proteomic screens identify Msps as a CLASP-Abl pathway interactor in Drosophila.

Regulation of cytoskeletal structure and dynamics is essential for multiple aspects of cellular behavior, yet there is much to learn about the molecular machinery underlying the coordination between the cytoskeleton and its effector systems. One group of proteins that regulate microtubule behavior and its interaction with other cellular components, such as actin-regulatory proteins and transport machinery, is the plus-end tracking proteins (MT+TIPs). In particular, evidence suggests that the MT+TIP, CLASP, may play a pivotal role in the coordination of microtubules with other cellular structures in multiple contexts, although the molecular mechanism by which it functions is still largely unknown. To gain deeper insight into the functional partners of CLASP, we conducted parallel genetic and proteome-wide screens for CLASP interactors in Drosophila melanogaster. We identified 36 genetic modifiers and 179 candidate physical interactors, including 13 that were identified in both data sets. Grouping interactors according to functional classifications revealed several categories, including cytoskeletal components, signaling proteins, and translation/RNA regulators. We focused our initial investigation on the MT+TIP Minispindles (Msps), identified among the cytoskeletal effectors in both genetic and proteomic screens. Here, we report that Msps is a strong modifier of CLASP and Abl in the retina. Moreover, we show that Msps functions during axon guidance and antagonizes both CLASP and Abl activity. Our data suggest a model in which CLASP and Msps converge in an antagonistic balance in the Abl signaling pathway.

Social support and sexually transmitted disease related healthcare utilisation in sexually experienced African-American adolescents.

OBJECTIVE: To determine whether adolescents' perceived social support predicts future utilisation of sexually transmitted disease (STD) related health care. METHODS: A longitudinal study of African-American adolescents ages 12-18 recruited from a random sample of households in the San Francisco Bay area in which baseline data were collected by telephone and follow up data were collected by telephone or in-home audio computer assisted self interview. At baseline, participants were asked about their sexual behaviours, STD history, and social support. At follow up 14-18 months later, participants were asked whether they, while asymptomatic, had sought STD related medical care within the past year. RESULTS: Asymptomatic sexually experienced adolescents who talked to their closest friend almost every day were more likely to have had STD related health care in the past year (odds ratio (OR) = 1.38; 95% confidence interval (CI) 1.09, 1.76). Closeness to female and male parents/guardians and participation in extracurricular activities were not associated with utilisation of STD related health care within the past year. After controlling for age and sex, sexually experienced adolescents who talked to or saw their closest friend almost every day were more likely to have had STD related health care within the past year (OR = 1.35; 95% CI = 1.08 to 1.70). CONCLUSIONS: These findings suggest that friends have an impact on the seeking of confidential healthcare services, such as care for STDs.

The CAD triad hypothesis: a mapping between three moral emotions (contempt, anger, disgust) and three moral codes (community, autonomy, divinity).

It is proposed that 3 emotions--contempt, anger, and disgust--are typically elicited, across cultures, by violations of 3 moral codes proposed by R. A. Shweder and his colleagues (R. A. Shweder, N. C. Much, M. Mahapatra, & L. Park, 1997). The proposed alignment links anger to autonomy (individual rights violations), contempt to community (violation of communal codes including hierarchy), and disgust to divinity (violations of purity-sanctity). This is the CAD triad hypothesis. Students in the United States and Japan were presented with descriptions of situations that involve 1 of the types of moral violations and asked to assign either an appropriate facial expression (from a set of 6) or an appropriate word (contempt, anger, disgust, or their translations). Results generally supported the CAD triad hypothesis. Results were further confirmed by analysis of facial expressions actually made by Americans to the descriptions of these situations.

Expression of genes involved in calcium absorption in human duodenum.

BACKGROUND: The role of vitamin D metabolites in the regulation of expression of genes involved in dietary calcium absorption by the human intestine remains poorly understood despite much work in animals. MATERIALS AND METHODS: To investigate this, we measured the expression of transcripts for two of these genes, calbindin-D9k and the basolateral membrane calcium pumping ATPase, PMCA1, in duodenal endoscopic biopsies from 40 subjects. Northern blots were hybridized with previously characterized probes, and the signal was quantified by phosphor imaging. These transcript levels were related to circulating vitamin D metabolites and also analysed according to the vitamin D receptor gene TaqI polymorphism determined in DNA from blood. RESULTS: Plasma 1,25-dihydroxycholecalciferol correlated significantly with calbindin-D9k RNA (r = 0.4, P < 0.02) but not with PMCA1. Plasma 25-OH-cholecalciferol was not correlated with transcripts for either gene and, furthermore, the mean levels of these transcripts did not differ significantly when grouped by vitamin D receptor genotype. CONCLUSION: In normal humans, 1, 25-dihydroxycholecalciferol has a small but significant relationship to duodenal expression of calbindin-D9k, but not to PMCA1 expression.

Charting progress.

Logbooks can be considered aggregate databases that registered nurses (RNs) have the primary responsibility of completing in most health care settings. However, RNs may be unaware of the many uses for the information contained in logbooks and the importance of these entries (Paine et al., 1988). Labor and delivery (L&D) logs provide an essential source of vital statistics birth data for the medical records staff. These data bits are used for reporting statistics, projecting trends, and planning future care for pregnant women.

Varieties of disgust faces and the structure of disgust.

In 3 facial expression identification studies, college students matched a variety of disgust faces to verbally described eliciting situations. The faces depicted specific muscle action movements in accordance with P. Ekman and W. V. Friesen's (1978) Facial Action Coding System. The nose wrinkle is associated with either irritating or offensive smells and, to some extent, bad tastes. Gape and tongue extrusion are associated primarily with what we call core or food-offense disgust and also oral irritation. The broader range of disgust elicitors, including stimuli that remind humans of their animal origins (e.g., body boundary violations, inappropriate sex, poor hygiene, and death), a variety of aversive interpersonal contacts, and certain moral offenses are associated primarily with the raised upper lip. The results support a theory of disgust that posits its origin as a response to bad tastes and maps its evolution onto a moral emotion.

Variable oxygen exposure causes preretinal neovascularization in the newborn rat.

PURPOSE: To test the hypothesis that variable hyperoxia potentiates preretinal neovascularization in newborn rats, and to establish a more reliable animal model of ROP in which therapies designed to inhibit abnormal angiogenesis can be tested. METHODS: Immediately after birth, litters of Sprague Dawley albino rats and mothers were placed in an incubator containing 40% oxygen. After 12 hours, the oxygen was increased to 80% with a transition time of less than 1 min. For the ensuing 7, 10, or 14 days, the oxygen was altered between 40% and 80% every 12 hr in a stepwise fashion. Other litters were kept in constant 80% oxygen or in room air for the same three time periods. After exposure, rats were either killed or placed in room air for an additional 2, 4, or 7 days before being killed. RESULTS: When rats were killed immediately after oxygen exposure, the resulting vessel loss in rats exposed to 40%/80% oxygen was identical to that of animals exposed to 80% (vessels constituted 12.2 +/- 2.2% of total retinal area in cyclic oxygen vs 12.0 +/- 1.2% in constant oxygen). However, preretinal neovascularization subsequently occurred in 66% (63/96) of all rats exposed to cyclic oxygen followed by a room air period but in no rats (0/50) exposed to constant oxygen followed by room air. Preretinal vascular proliferation consisted of glomerular tufts of endothelial cells, or mature, lumenized vessels containing red blood cells. CONCLUSIONS: Consistency of oxygen therapy is more important than overall oxygen level in inducing retinopathy. Consideration should be given to tighter control of intended oxygen therapy in premature infants, regardless of the target saturation level.

Oxygen-induced retinopathy in the rat: hemorrhages and dysplasias may lead to retinal detachment.

Rearing neonatal rats in hyperoxia induces the development of retinal hemorrhages and retinal dysplasia. Albino rats were placed in 80% oxygen immediately after birth and were exposed for either 5, 10, or 14 days, followed by sacrifice or exposure to normoxia for an additional 2, 4, 5, 7, 8, 10, 38, 45 or 56 days. Control rats were simultaneously raised in room air and sacrificed at the same times. All animals were enucleated and their eyes processed for light and electron microscopy. Eyecups were trimmed to facilitate cross-sectioning of the retina in the vertical meridian. No control rats showed signs of retinal hemorrhages or of dysplastic folds or rosettes. Nor did the retinas of rats killed immediately after oxygen exposure contain hemorrhages, but the incidence of retinal folds or rosettes in this group was 54%. For rats exposed to combinations of hyperoxia and brief normoxia (10 days or less), 40% suffered hemorrhages and 50% developed retinal folds or rosettes. Although hemorrhages were more prominent in rats subjected to longer periods of oxygen (73% of all rats exposed for 14 days followed by brief normoxia vs. 6% of those exposed for 5 days followed by brief normoxia), the incidence decreased with time post-exposure in room air. Hemorrhages occurred in 100% of the rats raised in oxygen for 14 days followed by 2 days in room air, and decreased to 50% by 7 days in room air and to 0% by 38 days, indicating a spontaneous resolution with time. In each case, the blood appeared to leak from the newly-forming vessels of the deep capillary net, with most of the red blood cells migrating to the subretinal space. Retinal fold or rosette formation, indicative of developmental dysplasia, occurred in a fraction of virtually all groups of exposed rats, and persisted at the longest post-exposure periods. These two manifestations of oxygen-induced retinopathy are emphasized because they lead to an abnormal separation of the retina from the epithelial layer, which may increase the likelihood of the most serious consequence of ROP--retinal detachment. In fact, all rats that endured post-exposure periods of 38 days or longer before sacrifice exhibited retinal detachment.

Virus-dependent cytostatic activity to mammary tumor cells of lymphocytes from normal mice.

A cytostasis assay has been used to study the natural immunity of mice to murine mammary tumor virus (MTV). Spleen cells from adults of all strains tested were found to be cytostatic to a variety of MTV-positive mammary tumor cell lines. Newborn spleen cells were unreactive in the same cytostasis assay. The degree of reactivity to the target cells was greater in spleen cell preparations from low MTV expressors than from syngeneic, high MTV expressors. The cytostasis was specific, since MTV antigens prepared from gradient-purified whole MT virions significantly blocked the reaction. In addition, spleen cells were totally nonreactive to MTV-negative cell lines. Other types of lymphoid cells, such as lymph node cells as well as peritoneal macrophages, were highly cytostatic under similar conditions. Spleen cells from nude athymic donors were not cytostatic. Since depletion of splenic T-lymphocytes by use of anti-theta serum also did not significantly affect cytostasis, it was concluded that T-cells were required for initiation of immunity to MTV but that the effector cells were not theta positive. Blocking factors were found to exist in the sera of mammary tumor-bearing animals that prevented cytostasis by reactive spleen cells.