National trends in the prevalence and severity of the periodontal diseases

In summary, between the 1960 to 1962 national health survey and the 1971 to 1974 national health survey, the mean periodontal index scores remained unchanged. However, the classification of adults into broad disease categories showed that those with no evidence of disease increased significantly. This improvement in the nation's experience with the periodontal diseases was restricted to those with gingivitis, and a concomitant improvement was observed in the nation's oral hygiene status; debris scores decreased substantially, whereas little change was observed in calculus scores. Hypotheses have been raised in this paper about the decline in the prevalence of gingivitis and its possible association with variables such as OHI-S scores, socioeconomic status, dental care utilization, cigarette smoking, fluorides, and antibiotics. Also noted between the two surveys was a slight decrease in the prevalence of periodontal pockets in persons younger than age 35, whereas in persons older than 35, there was either no change or a slight increase. During this same period, both total loss of teeth and number of missing teeth per person decreased for all ages. A hypothesis is proposed that links this slight increase in the more severe signs of periodontal disease in older adults to an increase in the number of teeth at risk to the disease. The modest change in the prevalence and severity of advanced periodontal disease may be an early sign of a trend that will become accentuated as a result of a distinct increase in the nation's older population coupled with the increased retention of the natural dentition. Thus, it would seem that a decline in edentulism and an increase in number of teeth per person may well contribute to circumstances that will lead to greater, not lesser, risk of advanced periodontal disease problems in the later decades of life. Although this hypothesis may or may not hold true for today's younger adults as they age, it seems to be the likely occurrence for the nation's older adults, at least for the next several decades. A third national survey, using the same indexes and more current periodontal disease measures, is needed to help to clarify the trends reported here.     

Psychotherapy supervision conducted via videoconferencing: A qualitative study of users' experiences

Forty-three patients who had been treated in hospital for major depression were studied 1 to 2 years after discharge. Patients retrospectively ranked physical exercise as the most important element in the comprehensive treatment programme. Most subjects continued with regular exercise after discharge, and most of these exercised aerobically at least 2 h a week. Exercisers tended to have lower depression scores at follow-up examination than nonexercisers.     

Mistiming Death: Modeling the Time-Domain Variability of Tumor Apoptosis and Implications for Molecular Imaging of Cell Death

Molecular Imaging and Biology - Apoptosis, in the context of cancer, is a form of programmed cell death induced by chemotherapy, radiotherapy, and immunotherapy. As this is a central pathway in...     

Use of a highly parallel microfluidic flow cell array to determine therapeutic drug dose response curves

A high-throughput, microfluidic flow cell array (MFCA) system has been modified to enable drug screening against small-volume cell-, and tissue cultures. The MFCA is composed of a 3D channel network that simultaneously flows fluids through forty-eight 830 μm by 500 μm flow cells, which physically divide and fluidically seal an existing culture into multiple compartments when docked onto the surface of a cell or tissue culture dish. The modified system provides temperature (37 °C) and CO₂/pH level controls, while continuously flowing solutions (media or other liquid such as drug suspensions) over the cells/tissues. These assays were enhanced and validated using inverted microscopy and fluorescent staining techniques which also allow real time viability and toxicity assessments. This work presents the results of this new generation in vitro drug testing assay performed using this modified MFCA system. This setup allows the testing of 48 drug combinations on 48 different cell-, tissue specimen at once under flow conditions. All 48 flow cells were utilized to test 5 different concentrations of cisplatin (CDDP). CDDP solutions in various concentrations were continually flowed over cultured human ovarian cancer cells for 48 h. Viability assessments were performed using red-orange calcein and SYTOX ® Green nucleic acid stains. Cells were imaged at the beginning and end of the experiment (48 h). In order to compare and validate MFCAs suitability as drug screening assay, MTT assays were performed on cells. We found that both, MTT and MFCA assays generated dose-response curves with similar profiles. Innovative advantages of the MFCA system include the ability of handling smaller amounts of solutions compared to conventional and current state of the art drug screening and cell viability/toxicity methods. It also provides the ability to continually deliver fresh solution to the cell samples, while eliminating wastes that are produced. Based on our here reported findings MFCA may have a strong potential of providing a more physiological model than current state of the art static MTT assays.