Effects of low-level laser treatment on mouth dryness

Mouth dryness (MD) is usually followed by inadequate mechanical cleaning of the mouth and decrease in the levels of salivary antimicrobial proteins (including secretory immunoglobulin A (sIgA)). It is accompanied by difficulties during speaking and food swallowing, with an unpleasant taste, burning sensations in the mouth and higher susceptibility to oral diseases. Low-level laser treatment (LLLT) can intensify cell metabolism and its application on salivary glands could improve salivation. The purpose of this study was to evaluate the effects of LLLT on salivation of patients suffering from MD. The study included 17 patients with MD. Their major salivary glands were treated with low intensity laser BTL2000 on 10 occasions. The whole unstimulated and stimulated saliva quantities were measured just before the 1st, after the 10th and thirty days following the last (10th) treatment. In the samples of unstimulated saliva concentrations of sIgA were estimated by using ELISA method and its quantity in the time unit was calculated. The visual analogue scale (VAS) score was used to assess burning and/or pain intensity at these three time points. Statistical tests revealed significant salivation improvement quantitatively and qualitatively, i.e. increase in the quantity of saliva and sIgA. VAS score was also significantly improved and no side effects were observed. Conclusions: According to the results of this study, application of LLLT to xerostomic patients' major salivary glands stimulates them to produce more saliva with better antimicrobial characteristics and improves the difficulties that are associated with MD. This simple non-invasive method could be used in everyday clinical practice for the treatment of MD.     

Development and validation of a risk model for prediction of hazardous alcohol consumption in general practice attendees: the predictAL study

Background

Little is known about the risk of progression to hazardous alcohol use in people currently drinking at safe limits. We aimed to develop a prediction model (predictAL) for the development of hazardous drinking in safe drinkers.

Methods

A prospective cohort study of adult general practice attendees in six European countries and Chile followed up over 6 months. We recruited 10,045 attendees between April 2003 to February 2005. 6193 European and 2462 Chilean attendees recorded AUDIT scores below 8 in men and 5 in women at recruitment and were used in modelling risk. 38 risk factors were measured to construct a risk model for the development of hazardous drinking using stepwise logistic regression. The model was corrected for over fitting and tested in an external population. The main outcome was hazardous drinking defined by an AUDIT score ≥8 in men and ≥5 in women.

Results

69.0% of attendees were recruited, of whom 89.5% participated again after six months. The risk factors in the final predictAL model were sex, age, country, baseline AUDIT score, panic syndrome and lifetime alcohol problem. The predictAL model''s average c-index across all six European countries was 0.839 (95% CI 0.805, 0.873). The Hedge''s g effect size for the difference in log odds of predicted probability between safe drinkers in Europe who subsequently developed hazardous alcohol use and those who did not was 1.38 (95% CI 1.25, 1.51). External validation of the algorithm in Chilean safe drinkers resulted in a c-index of 0.781 (95% CI 0.717, 0.846) and Hedge''s g of 0.68 (95% CI 0.57, 0.78).

Conclusions

The predictAL risk model for development of hazardous consumption in safe drinkers compares favourably with risk algorithms for disorders in other medical settings and can be a useful first step in prevention of alcohol misuse.     

Evidence for time-of-day dependent effect of neurotoxic dorsomedial hypothalamic lesions on food anticipatory circadian rhythms in rats

The dorsomedial hypothalamus (DMH) is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO) have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T(b)) rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T(b) rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T(b) rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep.     

Reversible acetylation of metabolic enzymes celebration: SIRT2 and p300 join the party

Compelling evidence suggests that metabolic pathways are coordinated through reversible acetylation of metabolic enzymes in response to nutrient availability. In this issue of Molecular Cell, Jiang et al. (2011) show that the rate-limiting enzyme in gluconeogenesis, phosphoenolpyruvate carboxykinase 1, is regulated through reversible acetylation by SIRT2 and p300.     

Association of Common Mental Disorders and Quality of Life with the Frequency of Attendance in Slovenian Family Medicine Practices: Longitudinal Study

Background

Most research on frequent attendance has been cross-sectional and restricted to one year attendance rates. A few longitudinal studies suggest that frequent attendance is self-limiting. Frequent attenders are more likely to have social and psychiatric problems, medically unexplained physical symptoms, chronic somatic diseases (especially diabetes) and are prescribed more psychotropic medication and analgesics.

Research Question

To describe the attendance rates in a longitudinal study and to test if depression, panic syndrome, other anxiety syndrome, alcohol misuse and general quality of life are associated with frequent attendance in next two consecutive years.

Methods

1118 consecutive family practice attendees, aged 18 to 75 years from randomly selected family medicine practices were recruited at baseline and followed up at 12 and 24 months. We identified frequent attenders in the top 10 centile within one year. Using a multivariate model, we ascertained if presence of common mental disorders and quality of life assessed at baseline in 2003 predict frequent attendance in 2004 and 2005.

Results

40% of frequent attenders continue to be frequent attenders in the following year and 20% of the frequent attenders were so for the 24 month period. Lower physical scores on the SF-12 questionnaire were strongly associated with future frequent attendance at 12 and 24 months. There was a trend for people with greater than elementary school education to be less likely to become frequent attenders at both 12 and 24 months. For other variables these effects were less consistent. Presence of major depression, panic syndrome, other anxiety syndrome and alcohol misuse were not predictive of frequent attendance in the following two years.

Conclusion

Low physical quality of life is strongly predictive of higher frequent attendance and similar finding was observed for people with lower educational level but further confirmatory research is required to establish this association.     

SIRT3 Reverses Aging-Associated Degeneration

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Highlights? SIRT3 is highly enriched in HSCs and suppressed in differentiated hematopoietic cells ? SIRT3 regulates HSC self-renewal under stress or at an old age ? SIRT3 regulates mitochondrial metabolic homeostasis and reduces ROS in HSCs ? SIRT3 is suppressed with age, and its upregulation rejuvenates aged HSCs     

The nucleolar GTP-binding proteins Gnl2 and nucleostemin are required for retinal neurogenesis in developing zebrafish

Nucleostemin (NS), a member of a family of nucleolar GTP-binding proteins, is highly expressed in proliferating cells such as stem and cancer cells and is involved in the control of cell cycle progression. Both depletion and overexpression of NS result in stabilization of the tumor suppressor p53 protein in vitro. Although it has been previously suggested that NS has p53-independent functions, these to date remain unknown. Here, we report two zebrafish mutants recovered from forward and reverse genetic screens that carry loss of function mutations in two members of this nucleolar protein family, Guanine nucleotide binding-protein-like 2 (Gnl2) and Gnl3/NS. We demonstrate that these proteins are required for correct timing of cell cycle exit and subsequent neural differentiation in the brain and retina. Concomitantly, we observe aberrant expression of the cell cycle regulators cyclinD1 and p57kip2. Our models demonstrate that the loss of Gnl2 or NS induces p53 stabilization and p53-mediated apoptosis. However, the retinal differentiation defects are independent of p53 activation. Furthermore, this work demonstrates that Gnl2 and NS have both non-cell autonomously and cell-autonomous function in correct timing of cell cycle exit and neural differentiation. Finally, the data suggest that Gnl2 and NS affect cell cycle exit of neural progenitors by regulating the expression of cell cycle regulators independently of p53.     

The ecophysiology of seed persistence: a mechanistic view of the journey to germination or demise

Seed persistence is the survival of seeds in the environment once they have reached maturity. Seed persistence allows a species, population or genotype to survive long after the death of parent plants, thus distributing genetic diversity through time. The ability to predict seed persistence accurately is critical to inform long‐term weed management and flora rehabilitation programs, as well as to allow a greater understanding of plant community dynamics. Indeed, each of the 420000 seed‐bearing plant species has a unique set of seed characteristics that determine its propensity to develop a persistent soil seed bank. The duration of seed persistence varies among species and populations, and depends on the physical and physiological characteristics of seeds and how they are affected by the biotic and abiotic environment. An integrated understanding of the ecophysiological mechanisms of seed persistence is essential if we are to improve our ability to predict how long seeds can survive in soils, both now and under future climatic conditions. In this review we present an holistic overview of the seed, species, climate, soil, and other site factors that contribute mechanistically to seed persistence, incorporating physiological, biochemical and ecological perspectives. We focus on current knowledge of the seed and species traits that influence seed longevity under ex situ controlled storage conditions, and explore how this inherent longevity is moderated by changeable biotic and abiotic conditions in situ, both before and after seeds are dispersed. We argue that the persistence of a given seed population in any environment depends on its resistance to exiting the seed bank via germination or death, and on its exposure to environmental conditions that are conducive to those fates. By synthesising knowledge of how the environment affects seeds to determine when and how they leave the soil seed bank into a resistance–exposure model, we provide a new framework for developing experimental and modelling approaches to predict how long seeds will persist in a range of environments.