Macroesthetics: facial and dentofacial analysis

Successful esthetic and prosthodontic treatment are inseparable. In esthetic treatment, the goal is an enhanced but natural-looking appearance in which all prosthodontic principles have been taken into account. By the same token, prosthodontic treatment is as much about esthetics as mechanical and biologic requirements. Using all disciplines of dentistry to create a functional and pleasing esthetic impression creates the most successful outcomes. This article reviews pertinent literature and discusses esthetic analysis from a macroesthetic perspective; i.e., taking into consideration the interrelationships of the face, lips, gingiva, and teeth.     

Does the 'average size' of women in the neighbourhood influence a woman's likelihood of body dissatisfaction?

We examined whether the 'average body size' of women within a neighbourhood was associated with the number of women reporting body dissatisfaction in that neighbourhood. Data from a random digit dialing telephone survey of 884 Canadian women (mean age 41) indicated that for a given individual body mass index (BMI) women who lived among 'thinner' women (a smaller average neighbourhood body mass index (BMI)) were more likely to feel dissatisfied with their own bodies than women who lived among 'larger' women (a larger average neighbourhood BMI). Our results are consistent with the need to consider places as well as people in explaining various health outcomes.     

Development of Ca2+-channel and BK-channel expression in embryos and larvae of Xenopus laevis

The patterns and density of channels expressed in neurons critically determine their electrical properties. We have examined developmental regulation of Ca2+-channel expression during the maturation of the spinal motor circuits in Xenopus as it develops from an embryo to a larva. In embryonic neurons approximately 60% of the current is carried by N-type channels, 8% by l-type channels and the remainder by an unidentified channel. As the embryo matures, omega-agatoxin-sensitive P/Q channels are gradually expressed and replace the unidentified HVA channel such that at stage 42 approximately 25% of the current is carried by P/Q channels. We have used fluorescent labelling of selective channel toxins to directly observe the distribution of P/Q, N and BK channels. The P/Q channel distribution was most prevalent on the cell surface proximal to the areas of the soma where processes emerge. Both N and BK channels were distributed throughout the soma but still exhibited concentration around the areas adjacent to the emergence of processes from the soma. The patterns of fluorescence labelling during development mirrored the development of the respective ionic currents. Both N and P/Q channels contribute roughly equally to activation of the BK current, suggesting that overlap in the distribution of the N, P/Q and BK channels is important in their functional interdependence. The newly expressed P/Q channels play a role in spike initiation and repetitive firing in larval spinal neurons and contribute to burst generation during swimming in the larva.     

Effects of difluoromethylornithine chemoprevention on audiometry thresholds and otoacoustic emissions

OBJECTIVES: To determine the effects of long-term, low-dose difluoromethylornithine (DFMO) on audiometric thresholds and distortion product otoacoustic emission (DPOAE) levels in humans. DESIGN: A prospective, randomized, placebo-controlled phase 2 clinical trial of DFMO in participants with a prior adenomatous colonic polyp. SETTING: Academic tertiary care referral center. PARTICIPANTS: One hundred twenty-three volunteer subjects with colorectal polyps and normal hearing for the frequencies 250 through 2000 Hz. INTERVENTIONS: Subjects were randomized to receive placebo or oral DFMO at daily dosages between 0.075 and 0.4 g/m(2) of body surface area for 12 months. OUTCOME MEASURES: Pure-tone audiometric thresholds for the frequencies 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz and DPOAE levels were measured at baseline and 1, 3, 6, 9, and 12 months after starting treatment with DFMO or placebo and 3 months after cessation of treatment if there was a suggestion of possible changes at the 12-month measurement. RESULTS: At these low dosages, there was little evidence for shifts in auditory pure-tone thresholds, and there were no statistically significant shifts in DPOAE levels. For auditory pure-tone thresholds, there was a subtle, approximately 2- to 3-dB hearing level decrease in hearing sensitivity for the 2 higher DFMO dosages, but only at the 2 lowest frequencies, 250 and 500 Hz. CONCLUSIONS: Administration of low-dose DFMO for 12 months did not produce hearing loss, in contrast to prior studies that used higher dosages.     

Breast cancer survival and in vitro tumor response in the extreme drug resistance assay

Purpose. To determine whether in vitro extreme drug resistance (EDR) assay results for patients with breast carcinoma were associated with clinical outcome after chemotherapy. Patients and methods. EDR assays were performed on tumor tissue obtained from 103 newly diagnosed breast cancer cases. EDR scores of 2 for low, 1 for intermediate, or 0 for extreme drug resistance were determined for each agent tested. In vitro EDR scores for 4-hydroxycyclophosphamide (4HC) and doxorubicin were summed for patients treated with AC, or for 4HC and 5-FU for patients treated with CMF. Treatment selection was blinded to assay results. Results. Median time to progression was significantly shorter for patients with extreme or intermediate in vitro resistance (n=55, 48 months), compared to patients with low in vitro resistance, (n=41, 100 months, p=0.022). Patients demonstrating extreme to intermediate drug resistance also showed poorer survival than the low resistance group (49.5 months vs. not reached, median follow-up 48 months, p=0.011). Summed EDR scores, stage, and number of lymph nodes were significantly associated with survival in univariate and multivariate analysis. Compared to EDR scores of 4, summed EDR scores of 0–1 and summed EDR scores of 2–3 were associated with a relative risk of death of 3.09 (95%, CI 1.05–9.06, Cox proportional hazards model, p=0.040) and 2.35 (95%, CI 1.07–5.15, Cox proportional hazards model, p=0.033), respectively. Conclusion. Extreme drug resistance testing identified patients with individual patterns of drug resistance prior to therapy. In this cohort of breast cancer patients treated with chemotherapy, summed EDR scores were significantly associated with time to tumor progression and overall survival. EDR results may offer a method for optimizing treatment selection.     

The role of perfectionism and excessive commitment to exercise in explaining dietary restraint: replication and extension

The etiological complexity of the eating disorders has incited researchers to examine how personality characteristics and other variables operate jointly in the development of deviant eating patterns. OBJECTIVE: This study investigated the independent, interactive, and indirect prediction of dietary restraint by perfectionism and excessive commitment to exercise. METHOD: Multiple regression analyses designed to test moderating and mediating models were conducted on a sample of female university students (n = 269). RESULTS: Several dimensions of perfectionism, as well as excessive commitment to exercise, significantly and independently predicted dietary restraint in these women. There was no evidence for an interaction effect. Mediation analyses suggested that for selected dimensions of perfectionism, the direct relationship between perfectionism and dietary restraint is partially explained by excessive commitment to exercise. DISCUSSION: Interventions aimed at challenging perfectionistic standards in the context of dieting need to address not only one's self-standards, but one's perceptions of standards held by others. The mediating role of excessive exercise commitment pinpoints this variable as an alternative intervention target in the prevention of excessive dieting.     

Expression and integrity of DNA topoisomerase II isoforms does not explain generic drug resistance in malignant mesothelioma

PURPOSE: Malignant mesothelioma is a tumour that is highly resistant to a number of different chemotherapy agents, yet the mechanisms by which resistance occurs are poorly understood. The pattern of resistance is consistent with disruption of topoisomerase function or expression. Coupled with this, we have previously noted a common serological reaction to the beta isoform of topoisomerase II, suggesting that it may be aberrantly expressed in patients with mesothelioma. METHODS: We assessed the expression of topoisomerase II isoforms in sections of primary tumour. We tested a panel of five mesothelioma cell lines for sensitivity to the known topoisomerase-targeting drugs, doxorubicin and etoposide. We sequenced expressed segments of the topoisomerase genes from these cell lines that have previously been associated with drug resistance. We then investigated other potential resistance mechanisms. RESULTS: We found that the beta isoform of topoisomerase II was more frequently expressed in primary tumours. Only one of the five cell lines was highly resistant to etoposide and this cell line was found to have a point mutation in the gene for topoisomerase IIalpha. Protein levels of topoisomerase IIalpha and beta did not correlate with sensitivity to either doxorubicin nor to etoposide. Semiquantitative analysis suggested that there was marked variation in the levels of mRNA expression of MRP, gamma-GCS and MDR1. None of these findings could be associated with resistance to chemotherapy. CONCLUSION: We conclude that mutations in topoisomerase IIalpha can be associated with extreme resistance of mesothelioma to etoposide. The generic drug resistance of this tumour requires further investigation.     

Gamma-knife radiosurgery for trigeminal neuralgia

Gamma knife was installed at the PD Hinduja National Hospital and Medical Research Centre, Mumbai, India, in January 1997. In the first year of gamma-knife radiosurgery to January 1998, we treated 110 patients, of whom six had medically refractory trigeminal neuralgia. Seven treatments were administered to this group of six patients (one had bilateral neuralgia). This report evaluates the effectiveness of radiosurgery treatment in these patients. The median age of the patients was 56 years and there were five males and one female. Following Leksell stereotactic frame fixation, a magnetic resonance imaging scan was done in all. The Leksell gamma plan was used for planning. A radiosurgery dose of 70–80 Gy was delivered to the trigeminal root entry zone, 2–4 mm anterior to the junction of the pons and trigeminal nerve with a single 4 mm collimator helmet. Complete pain relief was achieved in four patients. Two had partial relief. No patient developed any radiosurgery related morbidity during the follow-up period of 5–16 months. Radiosurgery seems to be an effective approach for medically or surgically refractory trigeminal neuralgia.