[A comparative study on early childhood caries detection by using international caries detection and assessment system-â ¡ and WHO criteria].

Objective: To investigate and compare the sensitivities of early childhood caries detection by using international caries detection and assessment system (ICDAS)-Ⅱ and WHO criteria. Methods: A total of 449 3-year-old children from four day care kindergartens in Beijing were enrolled in this study. Both ICDAS-Ⅱ and WHO criteria were used to assess the prevalence of caries in the given subjects. The decayed, missing, and filled teeth (dmft) index scores were calculated. In ICDAS-Ⅱ system, four cut-off points (D1, D2, D3 and D4) were employed to differentiate sound and decayed teeth: D1 (score 0 as sound, scores 1-6 as caries); D2 (0-1 sound, 2-6 caries); D3 (0-2 sound, 3-6 caries) and D4 (0-3 sound, 4-6 caries). SPSS software was used to analyze the data to decide the significance of differences. Results: The caries prevalence using ICDAS-Ⅱ were 76.6% (344/449), 71.3% (320/449), 52.8% (237/449) and 46.1% (207/449) for D1 to D4, respectively; the corresponding mean dmft scores were 4.95±4.85, 4.41±4.77, 2.54±3.69 and 1.97±3.10. The sites with highest caries prevalence were occlusal surface of mandibular molars in groups of D1 and D2 and proximal surface of maxillary anterior teeth in groups D3 and D4. In contrast, the caries prevalence was 48.8% (219/449) and the mean dmft was 2.27±3.54 when using WHO criteria, significantly lower than the detection rates by using ICDAS-Ⅱ (D1-D2) (P=0.00). This suggested that ICDAS-Ⅱ system was a more sensitive method in detecting early childhood caries. Conclusions: ICDAS-Ⅱ system might be superior in detection of incipient caries and be of specific value in prevention of early childhood caries.

Analyzing urban ecosystem variation in the City of Dongguan: A stepwise cluster modeling approach.

In this study, a stepwise cluster modeling approach (SCMA) is developed for analyzing urban ecosystem variation via Normalized Difference Vegetation Index (NDVI). NDVI is an indicator of vegetation growth and coverage and useful in reflecting urban ecosystem. SCMA is established on a cluster tree that can characterize the complex relationship between independent and dependent variables. SCMA is applied to the City of Dongguan for simulating the urban NDVI and identifying associated drivers of human activity, topography and meteorology without specific functions. Results show that SCMA performances better than conventional statistical methods, illustrating the ability of SCMA in capturing the complex and nonlinear features of urban ecosystem. Results disclose that human activities play negative effects on NDVI due to the destruction of green space for pursuing more space for buildings. NDVI reduces gradually from the south part to the north part of Dongguan due to increased gross domestic product and population density, indicating that the ecosystem in Dongguan is better in the south part. NDVI in the northeast part (dominated by agriculture) is sensitive to the growth of economy and population. More attention should be paid to this part for sustainable development, such as increasing afforestation, planting grass and constructing parks. Precipitation has a positive effect on NDVI due to the promotion of soil moisture that is beneficial to plants' growth. Awareness of these complexities is helpful for sustainable development of urban ecosystem.

Multiple ephrins regulate hippocampal neurite outgrowth.

Increasing evidence indicates that the eph family of ligands and receptors guides the formation of topographic maps in the brain through repulsive interactions. For example, we have recently found that in the hippocamposeptal system, the ligand ephrin-A2, which is expressed in an increasing gradient from dorsal to ventral septum, selectively induces pruning of topographically inappropriate medial hippocampal axons. The recent detection of ephrins A3 and A5, as well as A2, in the septum raised critical functional questions. Do the ligands act combinatorially, ensuring appropriate three-dimensional spatiotemporal projection, or do they exert entirely distinct actions in addition to guidance mechanisms? To approach these alternatives, we cloned mouse ephrin-A2 and compared the activities of the three ligands. Here, we show that these ligands reduce the number of hippocampal neurites in a similar fashion. The effect was regionally specific; medial hippocampal neurites were reduced 1.5- to 1.8-fold, whereas lateral hippocampal neurites were not significantly affected, conforming to topographic projection in vivo. Furthermore, we found that ephrins regulated neurite number in a stage-specific fashion, affecting E19 hippocampal neurites more than E16 neurites. Our observations suggest that all three septal ephrins, A2, A3, and A5, play spatiotemporally specific roles in guiding topographic projections from the hippocampus.

Ephrins stimulate or inhibit neurite outgrowth and survival as a function of neuronal cell type.

The Eph family of tyrosine kinase receptors and ligands play key roles in cell segregation and axon targeting in the developing nervous system. Interactions between the ligands and receptors cause repulsion or degeneration of receptor-positive axons from several brain regions including the retina, hippocampus, thalamus, and midbrain dopaminergic system. We extend these previous observations by showing that three A-ephrins also negatively regulate the growth of neurites from striatal and olfactory neurons. In addition to negative effects, however, we also report a trophic activity of the A-ephrins: Ephrin-A2 and A5 promote survival and neurite outgrowth of sympathetic neurons. These observations provide support to the notion that ephrins may function as either negative or positive signals in the developing nervous system.

A randomized double-blind placebo-controlled study to assess the effect of oral contraceptive pills on the outcome of medical abortion with mifepristone and misoprostol.

This was a randomized double-blind placebo-controlled trial to determine the effect of oral contraceptive (OC) pills taken immediately after medical abortion on the duration of bleeding and complete abortion rate. Two hundred women in the first 49 days of pregnancy were given 200 mg mifepristone orally followed by 400 microg misoprostol vaginally 48 h later. One day later, they were randomized to receive either OC pills (30 microg of ethinyl oestradiol and 0.15 mg of levonorgestrel per tablet) or placebo for 21 days. The complete abortion rates were 98% in the OC group and 99% in the placebo group. The median duration of bleeding was similar: 17 (range: 5-57) days in the OC group and 16 (range: 6-55) days in the placebo group. In the OC group there was a small but significant fall in the haemoglobin concentration by 14 days (5.3 g/dl) after administration of mifepristone. The incidence of side-effects was similar in the two groups. We conclude that the use of OC pills does not decrease the duration of bleeding after medical abortion nor does it affect the abortion rate.

Ephrin-dependent growth and pruning of hippocampal axons.

Neuronal connections are arranged topographically such that the spatial organization of neurons is preserved by their termini in the targets. During the development of topographic projections, axons initially explore areas much wider than the final targets, and mistargeted axons are pruned later. The molecules regulating these processes are not known. We report here that the ligands of the Eph family tyrosine kinase receptors may regulate both the initial outgrowth and the subsequent pruning of axons. In the presence of ephrins, the outgrowth and branching of the receptor-positive hippocampal axons are enhanced. However, these axons are induced later to degenerate. These observations suggest that the ephrins and their receptors may regulate topographic map formation by stimulating axonal arborization and by pruning mistargeted axons.

Regulation of thalamic neurite outgrowth by the Eph ligand ephrin-A5: implications in the development of thalamocortical projections.

The cerebral cortex is parcellated into different functional domains that receive distinct inputs from other cortical and subcortical regions. The molecular mechanisms underlying the specificity of connections of cortical afferents remain unclear. We report here that the Eph family tyrosine kinase receptor EphA5 and the ligand ephrin-A5 may play a key role in the exclusion of the limbic thalamic afferents from the sensorimotor cortex by mediating repulsive interactions. In situ hybridization shows that the EphA5 transcript is expressed at high levels in both cortical and subcortical limbic regions, including the frontal cortex, the subiculum, and the medial thalamic nuclei. In contrast, ephrin-A5 is transcribed abundantly in the sensorimotor cortex. Consistent with the complementary expression, the ligand inhibited dramatically the growth of neurites from neurons isolated from the medial thalamus but was permissive for the growth of neurites from lateral thalamic neurons, which is primarily nonlimbic. Similarly, the growth of neurites from Eph-A5-expressing neurons isolated from the subiculum was inhibited by ephrin-A5. Our studies suggest that the Eph family ligand ephrin-A5 serves as a general inhibitor of axonal growth from limbic neurons, which may serve to prevent innervation of inappropriate primary sensorimotor regions, thus contributing to the generation of specificity of thalamic cortical afferents.

Dual action of a ligand for Eph receptor tyrosine kinases on specific populations of axons during the development of cortical circuits.

The structural basis of cortical columns are radially oriented axon collaterals that form precise connections between distinct cortical layers. During development, these connections are highly specified from the initial outgrowth of collateral branches. Our previous work provided evidence for positional cues confined to individual layers that induce and/or prevent the formation of axon collaterals in specific populations of cortical neurons. Here we demonstrated with in situ hybridization techniques that mRNA of the Eph receptor tyrosine kinase EphA5 and one of its ligands, ephrin-A5, are present in distinct cortical layers, at a time when intrinsic connections are being formed in the cortex. Axonal guidance assays indicate that ephrin-A5 is a repellent signal for a populations of axons that in vivo avoid the cortical layer expressing ephrin-A5. In contrast to its established role as a repulsive axonal guidance signal, ephrin-A5 specifically mediates sprouting of those cortical axons that target the ephrin-A5-expressing layer in vivo. These results identify a novel function of ephrin-A5 on axonal arbor formation. The laminar distribution and the dual action on specific populations of axons suggest that ephrin-A5 plays a role in the assembly of local cortical circuits.

Pilot study on the use of a two-week course of oral misoprostol in patients after termination of pregnancy with mifepristone and misoprostol.

Twenty women who requested early first trimester termination of pregnancy were recruited to study the tolerability of a 2-week course of oral misoprostol after termination of pregnancy by mifepristone and vaginal misoprostol. Ten patients (50%) complained of mild diarrhea during the 2-week course of misoprostol. Otherwise, there were no other significant side effects. The 2-week course of misoprostol was well tolerated by women who underwent early first trimester termination of pregnancy with mifepristone and misoprostol.

PIP: A pilot study was conducted to assess whether prolonged use of misoprostol is well tolerated by women who have undergone termination of an early pregnancy with mifepristone and misoprostol and if this regimen increases the complete abortion rate and decreases the duration of bleeding. Enrolled were 20 women from Hong Kong and Shanghai with a menstrual delay of 21 days or less; the mean duration of pregnancy was 40.8 +or- 4.7 days. Women were given 200 mg of oral mifepristone, followed 48 hours later by 400 mcg of vaginal misoprostol. Oral misoprostol (400 mcg) was continued twice daily for 2 weeks. 11 women (55%) aborted during the initial 4-hour observation period and all had complete abortion. The mean duration of bleeding was 25.2 +or- 4.3 days. Nausea, diarrhea, and lower abdominal pain were the most common side effects of misoprostol, but all women were able to complete the 2-week course of treatment. On the basis of the findings of this pilot study, a prospective, randomized study with a larger number of patients is recommended to confirm whether a 2-week course of misoprostol can increase the abortion rate and decrease the duration of postabortal bleeding.

Clinical study on the termination of 388 high-risk early pregnancies with mifepristone and misoprostol.

PIP: The safety, efficacy, and acceptability of a mifepristone-misoprostol combination for the termination of high-risk early pregnancies were documented in a study conducted at International Peace Maternity and Child Hospital in Shanghai, China, in 1993-96. The 388 study participants required pregnancy termination for reasons including scarred uterus, reproductive tract malformations, uterine fibroids, history of repeated abortions, or pregnancy during lactation. All pregnancies were under 70 days of gestation (mean, 46.7 days). Women received 150 mg of oral mifepristone followed, on the 3rd day, by 600 mcg of misoprostol. The complete abortion rate was 92.3%, the incomplete abortion rate was 6.2%, and the pregnancy rate was 1.5%. The complete abortion rate was significantly higher in women with amenorrhea of 49 days or less (95.5%) than in those with amenorrhea of 50-69 days of duration (83.3%). In 11 of the 12 cases in which heavy bleeding necessitated emergency management, the pregnancy exceeded 49 days of gestation. 92% of study participants were satisfied with this regimen. In cases of method failure, the softening and dilatation of the cervix induced by the drugs made vacuum aspiration easier and less painful.^ieng

Regulation of topographic projection in the brain: Elf-1 in the hippocamposeptal system.

The hippocampus and septum play central roles in one of the most important spheres of brain function: learning and memory. Although their topographic connections have been known for two decades and topography may be critical for cognitive functions, the basis for hippocamposeptal topographic projection is unknown. We now report for the first time that Elf-1, a membrane-bound eph family ligand, is a candidate molecular tag for the genesis of the hippocamposeptal topographic projection. Elf-1 is expressed in an increasing gradient from dorsal to ventral septum. Furthermore, Elf-1 selectively allows growth of neurites from topographically appropriate lateral hippocampal neurons, while inhibiting neurite outgrowth by medial hippocampal neurons. Complementary to the expression of Elf-1, an eph family receptor, Bsk, is expressed in the hippocampus in a lateral to medial gradient, consistent with a function as a receptor for Elf-1. Further, Elf-1 specifically bound Bsk, eliciting tyrosine kinase activity. We conclude that the Elf-1/Bsk ligand-receptor pair exhibits traits of a chemoaffinity system for the organization of hippocamposeptal topographic projections.