Oral health and dental attendance patterns of Pacific people in Christchurch, New Zealand

OBJECTIVES: To determine levels of self-reported oral health, dental attendance patterns and barriers to seeking dental care among a Pacific community in New Zealand. DESIGN: Cross-sectional study using a self-completed questionnaire. SETTING: A Pacific Island Health Trust in Christchurch. PARTICIPANTS AND METHODS: Adults affiliated to the Pacific Trust Canterbury, who were in contact with any of the Trust's health services within a four-week period, were invited to complete a dental self-report questionnaire. RESULTS: One hundred and twenty-one Pacific adults took part in the study. The mean age of the sample was 38.7 years, with an age range of 17 to 77 years. Over half the respondents had not attended a dentist within the previous two years, and more than three-quarters had last attended a dentist because of pain. Most respondents had paid for their last treatment themselves, and over half had received an extraction because of infection. Participants who received a Government benefit were more likely to have used a public dental service than those in paid employment. Those who had not received education beyond secondary school were more likely to have used a public dental service than those who had achieved higher education levels. Males were more likely to have had a tooth removed due to infection than females; and Cook Island, Niuean and other Pacific groups were more likely to have had a tooth removed than Samoans. CONCLUSIONS: Most Pacific people among this sample were episodic dental attenders, usually presenting because of pain. Many depended on hospital dental departments, particularly beneficiaries, those with community services cards, and those in low socioeconomic occupations. Tooth loss was a common occurrence among this population. Further information on Pacific people's oral health in New Zealand would be beneficial.     

The red cell mass-arterial oxygen relationship in normal man: Application to patients with chronic obstructive airway disease

The normal relationship between red cell mass measured, with (51)chromium-labeled red cells, and arterial oxygen saturation (Sa(O2)) over the range from 97.3 to 83.4% was examined by studying 73 normal men residing at sea level and altitudes of 1600 and 3100 m. A simple, linear relationship between Sa(O2) and red cell mass was found over the entire range (r = - 0.7524, P < 0.001). In contrast, a correlation between red cell mass and arterial O(2) tension was found only over the lower half of the range of O(2) tensions where Sa(O2) was also decreased (r = - 0.7731, P < 0.005). This suggested that O(2) saturation rather than tension is the more important determinant of the erythropoietic response to chronic hypoxia. If this response is regulated by tissue O(2) tension, then it will be influenced by O(2) transport, which, in turn, is a function of blood flow and arterial O(2) content, and hence Sa(O2). In nine patients with chronic obstructive airway disease the relationship between red cell mass and Sa(O2) was also determined and was found to be steeper than in the normal subjects (P < 0.05).     

T cell memory. Long-term persistence of virus-specific cytotoxic T cells

This study documents that virus-specific CTL can persist indefinitely in vivo. This was accomplished by transferring Thy-1.1 T cells into Thy-1.2 recipient mice to specifically identify the donor T cell population and to characterize its antigenic specificity and function by using a virus-specific CTL assay. Thy-1.1+ T cells from mice previously immunized with lymphocytic choriomeningitis virus (LCMV) were transferred into Thy-1.2 mice persistently infected with LCMV. The transferred LCMV-specific CTL (Thy-1.1+ CD8+) eliminate virus from the chronically infected carriers and persist in the recipient mice in small numbers, comprising only a minor fraction of the total T cells. Upon re-exposure to virus, these long-lived "resting" CD8+ T cells proliferate in vivo to become the predominant cell population. These donor CD8+ T cells can be recovered up to a year post-transfer and still retain antigenic specificity and biological function. They kill LCMV infected H-2-matched cells in vitro and can eliminate virus upon transfer into a second infected host. In addition, these long-lived CD8+ T cells appear not to be dependent on help from CD4+ T cells, since depletion of CD4+ T cells has minimal or no effect on their biological properties (proliferation, CTL response, viral clearance). These donor CTL also exhibit an immunodominance over the host-derived LCMV-specific CTL response. When both host and donor T cells are present, the donor CTL response is dominant over the potential CTL response of the cured carrier host. Taken together, these results suggest that virus-specific CTL can persist for the life span of the host as memory cells.