Maturation of oral feeding skills in preterm infants.

AIM: Safe and successful oral feeding requires proper maturation of sucking, swallowing and respiration. We hypothesized that oral feeding difficulties result from different temporal development of the musculatures implicated in these functions. METHODS: Sixteen medically stable preterm infants (26 to 29 weeks gestation, GA) were recruited. Specific feeding skills were monitored as indirect markers for the maturational process of oral feeding musculatures: rate of milk intake (mL/min); percent milk leakage (lip seal); sucking stage, rate (#/s) and suction/expression ratio; suction amplitude (mmHg), rate and slope (mmHg/s); sucking/swallowing ratio; percent occurrence of swallows at specific phases of respiration. Coefficients of variation (COV) were used as indices of functional stability. Infants, born at 26/27- and 28/29-week GA, were at similar postmenstrual ages (PMA) when taking 1-2 and 6-8 oral feedings per day. RESULTS: Over time, feeding efficiency and several skills improved, some decreased and others remained unchanged. Differences in COVs between the two GA groups demonstrated that, despite similar oral feeding outcomes, maturation levels of certain skills differed. CONCLUSIONS: Components of sucking, swallowing, respiration and their coordinated activity matured at different times and rates. Differences in functional stability of particular outcomes confirm that maturation levels depend on infants' gestational rather than PMA.

Temporal lobe white matter asymmetry and language laterality in epilepsy patients.

Recent studies using diffusion tensor imaging (DTI) have advanced our knowledge of the organization of white matter subserving language function. It remains unclear, however, how DTI may be used to predict accurately a key feature of language organization: its asymmetric representation in one cerebral hemisphere. In this study of epilepsy patients with unambiguous lateralization on Wada testing (19 left and 4 right lateralized subjects; no bilateral subjects), the predictive value of DTI for classifying the dominant hemisphere for language was assessed relative to the existing standard-the intra-carotid Amytal (Wada) procedure. Our specific hypothesis is that language laterality in both unilateral left- and right-hemisphere language dominant subjects may be predicted by hemispheric asymmetry in the relative density of three white matter pathways terminating in the temporal lobe implicated in different aspects of language function: the arcuate (AF), uncinate (UF), and inferior longitudinal fasciculi (ILF). Laterality indices computed from asymmetry of high anisotropy AF pathways, but not the other pathways, classified the majority (19 of 23) of patients using the Wada results as the standard. A logistic regression model incorporating information from DTI of the AF, fMRI activity in Broca's area, and handedness was able to classify 22 of 23 (95.6%) patients correctly according to their Wada score. We conclude that evaluation of highly anisotropic components of the AF alone has significant predictive power for determining language laterality, and that this markedly asymmetric distribution in the dominant hemisphere may reflect enhanced connectivity between frontal and temporal sites to support fluent language processes. Given the small sample reported in this preliminary study, future research should assess this method on a larger group of patients, including subjects with bi-hemispheric dominance.

Calcium mobilization from the endoplasmic reticulum to the mitochondria during apoptosis in prostate cancer

Previous studies have implicated Ca2+ fluxes in the control of apoptosis but their exact roles in regulating the process remain obscure. Because Ca2+ can serve as a signal for cytochrome c release from isolated mitochondria, we hypothesized that alterations in intracellular Ca2+ compartmentalization might serve as a release signal in whole cells undergoing apoptosis. Exposure of human PC-3 prostate adenocarcinoma cells to staurosporine or DNA damaging agent (doxorubicin) but not to anti-Fas antibody led to early release of Ca2+ from the endoplasmic reticulum and subsequent accumulation of Ca2+ within mitochondria. Both events were blocked in cells stably transfected with Bcl-2 but were not affected by treatment with the pancaspase inhibitor, zVADfmk. The effects of staurosporine were associated with re-localization of Bax from the cytosol to both endoplasmic reticular and mitochondrial membranes. Neither ER Ca 2+ pool depletion nor mitochondrial Ca2+ uptake were observed in DU-145 cells that possess a frameshift mutation in the Bax gene unless wild-type Bax was restored via adenoviral gene transfer. Cytochrome c release and downstream features of apoptosis were attenuated by treatment with an inhibitor of mitochondria) Ca2+ uptake (RU-360). Although, direct pharmacological ER Ca2+ pool emptying in cells treated with thapsigargin did not lead to early cytochrome c release, pretreatment of cells with staurosporine dramatically sensitized mitochondria to thapsigargin-induced cytochrome c release. Together, our data demonstrate that ER-to-mitochondrial Ca2+ fluxes promote cytochrome c release and apoptosis in cells exposed to some (but not all) pro-apoptosic stimuli. ^

Maternal nutrition and oral health factors in early childhood caries

Background. Early Childhood Caries (ECC) is the most common chronic infectious disease of childhood worldwide. Seven of ten American children have one or more decayed or filled primary teeth by age five. ECC prevalence is especially high in lower socio-economic ethnic populations. Commonly recognized as a diet-induced disease, focal etiological factors include cariogenic bacteria, fermentable carbohydrates, and a susceptible newly erupted tooth. Sequencing of breast and/or bottle feeding and introduction of beikost come at a time when children's defense mechanisms and, perhaps maternal direction of children's dietary patterns, are not yet fully developed or mature. To date, most research has examined biological factors, while maternal factors, especially psychosocial ones, have received scant attention. Objective. To examine the association of psychosocial factors in terms of maternal nutrition and oral health knowledge, attitudes, and beliefs, as well as social support and self-efficacy (KABS2) in a population of socio-economically disadvantaged infants and young children. A secondary aim was to describe ECC prevalence in this population. Methods. This study examined cross-sectionally the relationship between selected maternal psychosocial variables and ECC in a convenience sample of Mexican-American women and very young children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in San Antonio, Texas. Mothers were surveyed by use of a criteria- and content-valid, reliable questionnaire, and dental examinations were conducted on 191 children, aged 5 to 47 months old. Results. Thirty-nine percent of the children had ECC. As assessed on a 30-question scale, women in whose children were diagnosed with ECC were found to demonstrate lower Knowledge ( p=0.03), Attitudes (p=0.02), Beliefs (p=0.04), and Social Support (p<0.01) scores, compared to women whose children were found to be caries-free. No differences in Self-Efficacy scores were found between the groups. Conclusions. These data indicate that current etiological model depicting relevant factors associated with ECC in Mexican-American infants and children of low socio-economic status should be broadened to include consideration of maternal psychosocial factors such as nutrition and oral health knowledge, attitudes, beliefs, and social support, and that these factors should be considered when planning educational approaches to reduce the occurrence of ECC. ^

Correlation between dental care utilization and oral cavity cancer in a large sample of community-based United States residents

Cancer of the oral cavity and pharynx remains one of the ten leading causes of cancer death in the United States (US). Besides smoking and alcohol consumption, there are no well established risk factors. While poor dental care had been implicated, it is unknown if the lack of dental care, implying poor dental hygiene predisposes to oral cavity cancer. This study aimed to assess the relationship between dental care utilization during the past twelve months and the prevalence of oral cavity cancer. A cross-sectional design of the National Health Interview Survey of adult, non-institutionalized US residents (n=30,475) was used to assess the association between dental care utilization and self reported diagnosis of oral cavity cancer. Chi square statistic was used to examine the crude association between the predictor variable, dental care utilization and other covariates, while unconditional logistic regression was used to assess the relationship between oral cavity cancer and dental care utilization. There were statistically significant differences between those who utilized dental care during the past twelve months and those who did not with respect to education, income, age, marital status, and gender (p < 0.05), but not health insurance coverage (p = 0.53). Also, those who utilized dental care relative to those who did not were 65% less likely to present with oral cavity cancer, prevalence odds ratio (POR), 0.35, 95% Confidence Interval (CI), 0.12–0.98. Further, higher income advanced age, people of African heritage, and unmarried status were statistically significantly associated with oral cavity cancer, (p < 0.05), but health insurance coverage, alcohol use and smoking were not, p > 0.05. However, after simultaneously controlling for the relevant covariates, the association between dental care and oral cavity cancer did not attenuate nor persist. Thus, compared with those who did not use dental care, those who did wee 62% less likely to present with oral cavity cancer adjusted POR, 0.38, 95% CI, 0.13-1.10. Among US adults residing in community settings, use of dental care during the past twelve months did not significantly reduce the predisposition to oral cavity cancer. However, due to the nature of the data used in this study, which restricts temporal sequence, a large sample prospective study that may identify modifiable factors associated with oral cancer development namely poor dental care, is needed. ^

Soft tissue oral wound healing in diabetic patients

This prospective observational cohort study investigated whether diabetic dental patients with poor glycemic control experience a higher risk of post-operative complications and diminished wound healing abilities after an oral surgical procedure such as implant placement. This study compared soft tissue oral wound healing complications between poorly controlled diabetic patients, well controlled diabetic patients and non-diabetic patients following surgical implant placement in the mandible with a total of 131 patients. A one week post-surgical follow-up visit involved an oral wound examination that consisted of evaluating for edema, erythema, exudate, oral pain, problems with flap closure, infection, and hematoma. Analyses were performed to determine significance differences in frequency of oral wound complications between the 3 diabetic groups. Two-by-two contingency tables using chi-square analysis were used to evaluate for significant differences in the proportion of each post-operative oral wound healing complication. This was done separately between non-diabetics and diabetics and between well-controlled and poorly controlled diabetics to calculate odds ratios. Confidence intervals were also calculated. This preliminary study showed that many of the complications were found not to be associated with diabetic status. Other complications such as edema and problems with flap closure were found to be less likely to occur in diabetics compared to non-diabetics and even in poorly controlled diabetics when compared to well-controlled diabetics. The results did not support the hypothesis that diabetic dental patients experience a higher risk than non-diabetic patients of post-operative soft tissue oral wound complications.^