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The effect of serum-clot contact time on laboratory results was studied by dividing each blood specimen into four blood collection tubes. The control sera were separated from the clot within 30 min of the collection. The other tubes were incubated at 32 °C, and the sera were separated at 3, 6, and 24 h. The sera were stored at 4 °C and analyzed at the same time. The stability of the tests was determined by comparing the results of the 3-, 6-, and 24-h samples with the values from the 30-min samples. The acceptable limits around the 30-min values were derived from the analytical and intraindividual biological variation of the tests. A total of 63 analytes were studied. Potassium, phosphorous, and glucose were the least stable, and the serum should be separated from the clot within 3 h for these analytes. Albumin, bicarbonate, chloride, C-peptide, HDL-cholesterol, iron, LDL-cholesterol, and total protein should be separated within 6 h. The other analytes were stable for 24 h of serum-clot contact.

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Objective. In a randomized trial of women with early stage breast cancer undergoing adjuvant chemotherapy, two stress management interventions, tai chi training and spiritual growth groups, were compared to a usual care control group, to evaluate psychosocial functioning, quality of life (QOL), and biological markers thought to reflect cancer- and treatment-specific mechanisms. Method. The sample consisted of 145 women aged 27–75 years; 75% were Caucasian and 25% African American. A total of 109 participants completed the study, yielding a 75% retention rate. Grounded in a psychoneuroimmunology framework, the overarching hypothesis was that both interventions would reduce perceived stress, enhance QOL and psychosocial functioning, normalize levels of stress-related neuroendocrine mediators, and attenuate immunosuppression. Results. While interesting patterns were seen across the sample and over time, the interventions had no appreciable effects when delivered during the period of chemotherapy. Conclusions. Findings highlight the complex nature of biobehavioral interventions in relation to treatment trajectories and potential outcomes. Psychosocial interventions like these may lack sufficient power to overcome the psychosocial or physiological stress experienced during the chemotherapy treatment period. It may be that interventions requiring less activity and/or group attendance would have enhanced therapeutic effects, and more active interventions need to be tested prior to and following recovery from chemotherapy.

The purpose of this report is to investigate sample size requirements for both equivalence and superiority studies investigating products used in regeneration. The goal of a superiority clinical trial is to determine if a new therapy is superior to an established therapy or placebo. In contrast to superiority trials, equivalence trials are used to determine if a new product has similar therapeutic properties to an established product. The sample sizes for the two different types of clinical trials were based on the following assumptions: an alpha of 0.05, a power of 0.80, a 2 group parallel arm study, and equal variances and sample sizes for both groups. Separate sample size calculations were done for both intrabony defects and Class II furcation defects. Sample sizes for the equivalence and superiority trials using the same criteria were the same. However, criteria for estimating sample sizes for equivalence clinical trials require much smaller differences between groups, resulting in much larger sample sizes. A criterion of a 20% difference between groups of the total therapeutic effect resulted in sample sizes which ranged from 64 to 127 in equivalence clinical trials. These samples sizes are much larger than have been generally used in clinical trials investigating periodontal regeneration.