Assessment of dental maturity of western Chinese children using Demirjian's method.

Age estimation plays an important role in forensic medicine and orthodontics. Dental maturity, expressed as dental age, is one of the common indices for age estimation. Demirjian's method, first described in 1973 and based on a large number of French-Canadian samples, is one of the most widely used methods for dental age assessment. The aim of this study is to evaluate the applicability of Demirjian's method for dental age estimation in western Chinese children. Digital panoramic radiographs of 445 children of western Chinese origin, ranging from 8 to 16 years old, were assessed in Demirjian's method. The dental maturity scores (DMSs) and dental ages of all the subjects were calculated by a single observer. The dental ages were compared to the chronological ages with a paired t-test. The general trend in this research showed that the western Chinese children demonstrated a more advanced dental age compared to French-Canadian children as previously presented by Demirjian. The mean difference in each age group between the dental age and chronological age ranged from 0.0071 to 1.2500 years in girls and from -1.0000 to 1.3000 years in boys. The standards of dental age assessment provided by Demirjian for French-Canadian children may be not suitable for western Chinese children. As a result, specific standards of dental age assessment should be established for this population.

Specialist community palliative care services--a survey of general practitioners' experience in Eastern Sydney.

The role of the general practitioner (GP) in providing palliative care in the community is of increasing importance. Concomitantly, there is more interaction between the palliative care support services and the GP. Even when there is input from the palliative care support services, there can be barriers that impede effective delivery of palliative care by the GP. These include poor communication between the GP and the supporting team, inaccessibility of the service and inadequate after-hours coverage. We carried out a postal survey to assess what experiences and perceptions GPs working within the Eastern Sydney Area had of our palliative care support service. The response was generally favourable, with most GPs finding the level of communication, accessibility, usefulness of advice given and degree of follow-up visits by the service to be adequate. However, an important number felt that we tended to over-hospitalise our patients.

Polymorphonuclear neutrophils and their mediators in gingival tissues from generalized aggressive periodontitis.

BACKGROUND: Impaired polymorphonuclear neutrophil (PMN) functions were generally considered to be related to the onset of generalized aggressive periodontitis (GAgP). However, some research has indicated that the hyperreactivity of PMN seems to be involved in the inflammatory response of GAgP. The present study's main purpose was to provide more evidence about the role of PMN in the pathogenesis of GAgP by surveying PMN infiltration in gingiva and its relationship with the expression of their mediators including intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha). The inflammatory response in GAgP was also compared with that in adult periodontitis (AP) and periodontally healthy subjects. Since these PMN mediators were reported to be produced mainly by macrophages, the association between the expression of these PMN mediators and the distribution of macrophages was also investigated. METHODS: A total of 25 gingival specimens were obtained from 10 GAgP patients, 10 AP patients, and 5 periodontally healthy subjects. Serial sections were obtained from each specimen, and the following techniques were adopted to investigate the distribution and interrelation of different cells and cytokines. Infiltration of PMN was observed by using hematoxylin and eosin staining. Distribution of the macrophages, identified as CD68+, was shown by using immunohistochemistry. Immunohistochemistry and in situ hybridization were used to detect the expression of ICAM-1, IL-8, IL-1beta, and TNF-alpha in gingival tissues. These techniques were performed in serial sections from each individual specimen. RESULTS: Large numbers of infiltrating PMNs were observed in gingiva from GAgP. In gingiva from both GAgP and AP, the strongest protein and mRNA expression of IL-8, ICAM-1, IL-1beta, and TNF-alpha were located in pocket epithelium and adjacent connective tissue with large numbers of infiltrating PMNs. In tissues without abundant PMN infiltration, the appearance of positive cells expressing IL-8, ICAM-1, IL-1beta, and TNF-alpha was scattered. CD68+ was distributed sparsely in connective tissue and was hardly seen in pocket epithelium with large numbers of PMN infiltration. The degree of leukocyte infiltration and connective tissue destruction in gingiva from GAgP patients was not distinctly different from that in gingiva from AP. The gingival specimens with heavy PMN infiltration from both GAgP and AP patients presented strong expressions of IL-1beta and TNF-alpha; showed more extensive inflammatory cell infiltration; had severe connective tissue destruction; and presented severe elongation and ulceration of pocket epithelium. In gingiva from healthy subjects, inflammation was minor with visually no PMN, CD68+, or the positive cells of IL-8, ICAM-1, IL-1beta and TNF-alpha expression. CONCLUSIONS: Enhanced accumulation of PMN, which is associated with the upregulation of IL-8, ICAM-1, IL-1beta, and TNF-alpha expression, relates to the severity and activity of GAgP. In addition to macrophages, PMN and/or epithelial cells might also be important sources of IL-8, IL-1beta, and TNF-alpha production in gingiva.

[Degree of cellular proliferation in the first-time bone marrow smear and its significance in the diagnosis of aplastic anemia].

According to the cellularity in the first bone marrow aspirate, 541 cases of aplastic anemia (AA) diagnosed in the Peking Union Medical College Hospital were divided into two groups--hypoplastic and hyperplastic. Comparison of the transformation, remission and long-term survival rates in the two groups showed the following results. (1) Transformation: In the hypoplastic group, 60% of the cases maintained the original degree of proliferation, 34% was transformed to hyperplastic, 3% had repeated transformation and 3% became leukemic. In the hyperplastic group, 44% maintained the original degree of proliferation, 44% was transformed to hypoplastic, 9.3% had repeated transformation and 2.7% became leukemic. (2) Remission rate: The total remission rate was 15.9% in the hypoplastic and 14.6% in the hyperplastic group. (3) Long-term survival rate: The 1-, 5- and 10-year survival rates were 70.43%, 57.66% and 51.51% in the hypoplastic group, while they were 86.7%, 71.24% and 63.34% respectively in the hyperplastic with statistical significance (P less than 0.01). It is emphasized that AA can not be ruled out if there is hyperplasia in the bone marrow smear taken for the first time or in several smears taken from the same site. Smears taken periodically from different sites are essential for correct diagnosis.

The effect of dietary restriction of varying duration on survival, tumor patterns, immune function, and body temperature in B10C3F1 female mice.

Seven groups of mice were maintained on different dietary programs varying with respect to restriction at various stages of life. Restriction was associated with less age-related decline in T-dependent immunological function and a slight but significant lowering of body temperature. The best mean and maximum survival and the lowest late-life mortality rate was found in the group restricted throughout life, but restriction during any part of the lifespan enhanced survival to some degree. The mean life spans of tumor-bearing animals tended to be greater in restricted than in nonrestricted groups, corresponding to an age-decelerating effect. Tumor frequency varied with the period of life during which restriction took place and was not always decreased in restricted animals. These latter results suggest that the mechanisms whereby dietary restriction influences the aging rate and tumor susceptibility may not be entirely identical.

Effect of temperature-transfer on growth of laboratory populations of a South American annual fish Cynolebias bellottii.

Previous observation had shown that annual fish living at 15 degrees C grow faster and live longer than those at 20 degrees C. We now demonstrate that when populations of these fish undergo reciprocal transfer between these two temperatures, their growth rates change to that of animals living at the temperature into which they have been transferred. These growth rates do not entirely correlate with the longevity patterns observed in annual fish subjected to temperature-transfer, nor to certain other observations of the relationships among growth, temperature and longevity as reported in the literature.

Mid-life temperature-transfer effects on life-span of annual fish.

When annual fish are transferred from 20 C. to 15 C. at slightly less than the midpoint of lifespan of those kept throughout life at 20 C., the survival of the transferees exceeds theoretical expectations. They live longer than those maintained throughout life at 15 C., which had previously manifested the longest survival. These results indicate that the influence of temperature on life-span is not uniform throughout the life of a poikilothermic vertebrate. The phenomenon of partial temperature-independency had been previously demonstrated in invertebrates.

Immune function and survival in a long-lived mouse strain subjected to undernutrition.

Functional immune changes were monitored in populations of the long-lived C57BL/6J strain of mice which were subjected to dietary restriction from time of weaning or subjected to such restriction both before and after weaning, along with the appropriate control populations. Responses to T and B cell mitogens (PHA, Con-A, pokeweed, bacterial lipopolysaccharide, and PPD), to injected sheep red blood cells, and measurement of skin allograft rejection rates were followed. Early in life, restricted mice appear immunosuppressed, as judged by all these parameters. Skin allograft rejection remained suppressed until relatively late in life. Other responses tended to reverse from the earlier pattern; by mid-life restricted mice responded better than controls. Dietary restriction profoundly affects the immune system. Mice on such regimes display anatomic and certain immune functional changes which suggest that the immune system may mature less rapidly and stay "younger" longer than in the controls. Furthermore, dietary restriction results in prolongation of life span.