A clinical,randomized study on the influence of dental whitening on Streptococcus mutans population

Background

Dental whitening with peroxides has been popularized through the at‐home technique, which employs low concentrations of peroxide applied in individual trays. However, there are few clinical trials reporting the effects of its continuous use on oral microbiota. Thus, the purpose of the present clinical, randomized study was to evaluate the influence of at‐home whitening treatment on Streptococcus mutans in saliva, buccal mucosa, and subgingival and supragingival plaque.

Methods

Thirty volunteers were randomly divided into two study groups (N = 15) according to the whitening therapy: G CP, whitening using 10% carbamide peroxide 4 h daily for 21 days; and G HP, whitening using 6% hydrogen peroxide 1.5 h daily for 21 days. Samples from the predetermined locations were collected at three evaluation periods: T1, before; T2, immediately after; and T3, 30 days after the beginning of the treatment. The microbiological evaluation was made using conventional and molecular methods.

Results

Student's t‐test demonstrated a statistically significant decrease in S. mutans population in the subgingival and supragingival plaque for HP samples between T1 and T2 no difference was found between T1 and T3 regardless of the location and the whitening product used (α = 0.05).

Conclusions

Although HP reduced S. mutans during treatment, the levels returned to baseline when assessed 30 days after the treatment.     

Quantitation and properties of the active and latent plasminogen activator inhibitors in cultures of human endothelial cells

Human endothelial cells release two forms of a plasminogen activator- specific inhibitor: an active form that readily binds to and inhibits plasminogen activators and an inactive or latent form that has no anti- activator activity but which can be activated by denaturation. Latent and active forms of plasminogen activator-specific inhibitor were measured in cultures of human umbilical vein endothelial cells. Latent inhibitor was activated by treatment with 1% sodium dodecyl sulfate (SDS), and both forms were assayed by the 125I-fibrin plate method. After 16 hours, the conditioned medium contained 104.6 U/mL latent inhibitor activity and 2.6 U/mL active inhibitor. The level of each form in the culture medium increased with time although the activity associated with the latent form rose more rapidly: the ratio of latent to active inhibitor activity was 12 at four hours (10.3 U/mL v 0.86 U/mL) and reached 56 at 24 hours (155.3 U/mL v 2.80 U/mL). Intracellular inhibitor activity was associated with the active form only; no additional inhibitor activity was observed following SDS treatment of cell extracts. A decline in active inhibitor activity occurred during incubation at 37 degrees C with a 50% reduction in activity occurring in two hours. Treatment of conditioned medium with 10 U/mL thrombin also resulted in a loss of active inhibitor activity. The latent inhibitor, however, was not affected by either of these conditions. The inhibitor activity lost during incubation at 37 degrees C or thrombin treatment could be regenerated by SDS treatment, suggesting that the loss of the active inhibitor activity represented a conversion of this form to its latent counterpart. Thus, the concentration, stability, and regulation of these two forms of plasminogen activator inhibitor in human endothelial cell cultures differ significantly.     

Egg sharing and egg donation: attitudes of British egg donors and recipients

The question of payment to egg donors has recently focused the attention of both the Human Fertilisation and Embryology Authority (HFEA) and licensed clinics. An acute shortage of egg donors and the rising costs of assisted conception treatment are matters of grave concern to many patients. To understand the emotional and social effects of egg sharing and egg donation, we conducted a survey of attitudes in a group of women who had some knowledge or experience of egg donation. A total of 750 questionnaires were sent out of which 217 were returned within the specified time limit. From these, 107 respondents had experience of egg donation and 110 had made enquiries about donation. The data from these questionnaires were collated and tabulated by the National Opinion Polls (NOP) Research Group. An analysis of the data produced the following key findings: (i) donating or sharing eggs is a social issue, 94% discuss it with partners/family/friends; (ii) altruistic motives are not the prerogative of non-patient volunteers-egg share donors felt that helping the childless was as important as having a chance of in-vitro fertilization (IVF) for themselves; (iii) the treatment procedure causes the most anxiety for egg donors. The recipients were most concerned about delays, donor characteristics and how the eggs were allocated; (iv) most respondents (65%) with prior experience of egg sharing would do it again - 63% of egg share donors, 72% of egg share recipients; (v) cash rewards to egg donors and outright advertising for donors were rejected by 64 and 62% of the sample respectively; and (vi) counselling was highly valued and there were no instances of 'shattered lives' after treatment. The findings do not support the recently announced intentions of the HFEA to disallow payment to gamete donors on the grounds of devalued consent. There is no precedent in modern medicine for egg sharing. The patients surveyed drew a clear distinction between egg sharing and financial rewards. As long as egg donation is not covered by the National Health Service, it is fairer to offer egg sharing than to refuse treatment to those unable to pay.      

Taking tissue seriously means taking communities seriously

Background  

Health research is increasingly being conducted on a global scale, particularly in the developing world to address leading causes of morbidity and mortality. While research interest has increased, building scientific capacity in the developing world has not kept pace. This often leads to the export of human tissue (defined broadly) from the developing to the developed world for analysis. These practices raise a number of important ethical issues that require attention.     

Pregnancy following intracytoplasmic sperm injection treatment with dead husband's spermatozoa: ethical and policy considerations

This paper describes the first pregnancy in a childless widow after intracytoplasmic sperm injection (ICSI) treatment with her deceased husband's spermatozoa which had been stored for nearly 3 years before use. Before his death the husband had received treatment for testicular cancer and he had given the appropriate written consent for the future use of his spermatozoa. Of the 10 eggs injected, six resulted in normal embryos. Three embryos were transferred and the remaining three embryos are currently stored for possible future use. The treatment resulted in a continuing singleton pregnancy. The case demonstrated the suitability of ICSI in those difficult cases where the sperm quality is extremely poor. This success is also compared with a widely debated case of another widow who was refused permission to use her deceased husband's spermatozoa. It is concluded that in the case of posthumous use of frozen spermatozoa, the current laws are conveniently applicable in a chronic illness but not so in an acute illness leading to death. In the light of the wide public debate on the issues raised by this legal case, the UK Government has also decided to conduct a review of consent procedures involving the storage and use of genetic material.