Enamel erosion control by strontium-containing TiO2- and/or MgO-doped phosphate bioactive glass.

OBJECTIVES: To evaluate the effect of strontium-containing titanium- and/or magnesium-doped phosphate bioactive glass on the control of dental erosion. MATERIALS AND METHODS: Fifty fragments of human enamel were divided into five groups: negative control, 45S5 bioglass, strontium-containing Ti-doped phosphate bioactive glass (PBG-Ti), strontium-containing Mg-doped phosphate bioactive glass (PBG-Mg), and strontium-containing Ti- and Mg-doped phosphate bioactive glass (PBG-TiMg). The specimens underwent cycles of erosive challenge twice daily for 5 days with 1 mL of citric acid for 2 min followed by 1 mL of the suspension with bioactive substances for 3 min. After the cycles, profilometry, roughness and microhardness testing, and scanning electron microscopy (SEM) were performed. The following statistical tests were used: one-way ANOVA (profile, roughness, and surface microhardness (%VMS) data variation), Tukey's HSD (%VMS), Games-Howell test (profilometry), Student's t test (roughness), and Pearson's correlation between the variables. RESULTS: The lower loss of enamel surface and lower %VMS was observed in the PBG-Mg and PBG-TiMg groups, and only the PBG-Mg group showed similar roughness between baseline and eroded areas (p > 0.05). On SEM micrographs, PBG-Ti and PBG-Mg groups showed lower apparent demineralization. CONCLUSION: All bioactive materials protected the enamel against erosion. However, strontium-containing phosphate bioactive glasses showed lower enamel loss, and the presence of Mg in these bioactive glasses provided a greater protective effect. CLINICAL RELEVANCE: Experimental strontium-containing phosphate bioactive glasses are effective in controlling enamel erosion. The results obtained in this study will guide the development of new dental products.

Qualitative Analysis of the Experience of Mental Fatigue of Family Caregivers of Patients With Cancer in Phase I Trials.

PURPOSE/OBJECTIVES: To examine family caregivers' experience of mental fatigue, identify strategies they use to manage it, and ascertain the kind of help they would like from healthcare professionals.
. RESEARCH APPROACH: Descriptive, qualitative study that was part of a larger mixed-methods study.
. SETTING: Metropolitan comprehensive cancer center in the midwestern United States.
. PARTICIPANTS: 79 family caregivers of patients with advanced cancer who were participating in phase I clinical trials.
. METHODOLOGIC APPROACH: Caregivers completed a semistructured, open-ended questionnaire and demographic and health history forms.
. FINDINGS: Caregivers were able to define mental fatigue and give many examples of it. They reported that mental fatigue did not interfere with patient care, but that it did have a negative effect on their own self-care. They identified strategies to manage mental fatigue. They wanted more information and support from professionals.
. CONCLUSIONS: The majority of caregivers experienced mental fatigue, which manifested as trouble concentrating, difficulty remembering things, and irritability. The majority worked outside of the home and had health problems of their own.
. INTERPRETATION: Healthcare professionals need to assess caregivers for mental fatigue and find ways to help them reduce mental fatigue and restore their attention. Nurses are in a prime position to mobilize resources for caregivers to effectively manage burden and reduce mental fatigue.

The impact of caregiving on the psychological well-being of family caregivers and cancer patients.

OBJECTIVES: To provide an overview of patient and caregiver emotional distress; examine the sources of their distress, review evidence-based interventions that can reduce distress, and provide guidelines for assessment and intervention. DATA SOURCES: Peer-reviewed publications. CONCLUSION: There is a significant, reciprocal relationship between patient and caregiver emotional distress. Sources of distress vary by phase of illness. Evidence-based interventions can reduce distress and anxiety, but often are not implemented in practice. IMPLICATIONS FOR NURSING PRACTICE: Nurses need to assess patients and family caregivers for distress and intervene to reduce distress by fostering patient-caregiver teamwork, communication, and self-care; providing information; and referring to resources as needed.

Trastuzumab emtansine: a unique antibody-drug conjugate in development for human epidermal growth factor receptor 2-positive cancer.

Trastuzumab emtansine (T-DM1) is a human epidermal growth factor receptor (HER2)-targeted antibody-drug conjugate, composed of trastuzumab, a stable thioether linker, and the potent cytotoxic agent DM1 (derivative of maytansine), in phase III development for HER2-positive cancer. Extensive analysis of T-DM1 in preclinical studies has shown that T-DM1 combines the distinct mechanisms of action of both DM1 and trastuzumab, and has antitumor activity in trastuzumab- and lapatinib-refractory experimental models. Clinically, T-DM1 has a consistent pharmacokinetics profile and minimal systemic exposure to free DM1, with no evidence of DM1 accumulation following repeated T-DM1 doses. Although a few covariates were shown to affect interindividual variability in T-DM1 exposure and clearance in population-pharmacokinetics analyses, the magnitude of their effect on T-DM1 exposure was not clinically relevant. Phase I and phase II clinical trials of T-DM1 as a single agent and in combination with paclitaxel, docetaxel, and pertuzumab have shown clinical activity and a favorable safety profile in patients with HER2-positive metastatic breast cancer. Two randomized phase III trials of T-DM1 are recruiting patients: EMILIA (NCT00829166) is evaluating T-DM1 compared with lapatinib plus capecitabine, and MARIANNE (NCT01120184) is evaluating T-DM1 plus placebo versus T-DM1 plus pertuzumab versus trastuzumab plus a taxane. Additional combinations of T-DM1 (for example, with GDC-0941) and additional disease settings (early-stage HER2-positive breast cancer) are also under investigation. Data from the phase III trials and other studies of T-DM1-containing agents are eagerly awaited.