Xylitol Chewing Gums and Caries Rates: A 40-month Cohort Study

Dental caries is a pandemic infectious disease which can affect the quality of life and consumes considerable health care resources. The chewing of xylitol, sorbitol, and even sugar gum has been suggested to reduce caries rates. No clinical study has simultaneously investigated the effectiveness of these gums when compared with a group receiving no chewing gum. A 40-month double-blind cohort study on the relationship between the use of chewing gum and dental caries was performed in 1989-1993 in Belize, Central America. One thousand two hundred and seventy-seven subjects (mean age, 10.2 years) were assigned to nine treatment groups: one control group (no supervised gum use), four xylitol groups (range of supervised xylitol consumption: 4.3 to 9.0 g/day), two xylitol-sorbitol groups (range of supervised consumption of total polyols: 8.0 to 9.7 g/day), one sorbitol group (supervised consumption: 9.0 g/day), and one sucrose group (9.0 g/day). The gum use during school hours was supervised. Four calibrated dentists performed the caries registrations by means of a modified WHO procedure. The primary endpoint was the development of an unequivocal caries lesion on a non-cavitated tooth surface. Compared with the no-gum group, sucrose gum usage resulted in a marginal increase in the caries rate (relative risk, 1.20; 95% confidence interval, 0.96 to 1.49; p = 0.1128). Sorbitol gum significantly reduced caries rates (relative risk, 0.74; 95% confidence interval, 0.6 to 0.92; p = 0.0074). The four xylitol gums were most effective in reducing caries rates, the most effective agent being a 100% xylitol pellet gum (relative risk, 0.27; 95% confidence interval, 0.20 to 0.36; p = 0.0001). This gum was superior to any other gum (p < 0.01). The xylitol-sorbitol mixtures were less effective than xylitol, but they still reduced caries rates significantly compared with the no-gum group. DMFS analyses were consistent with these conclusions. The results suggest that systematic usage of polyol-based chewing gums reduces caries rates in young subjects, with xylitol gums being more effective than sorbitol gums.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68231/2/10.1177_00220345950740121501.pd

Hearing and tinnitus in head and neck cancer patients after chemoradiotherapy

Peer reviewe

Cerebrospinal fluid cytokines in Lyme neuroborreliosis

Background: Lyme neuroborreliosis (LNB) is one of the manifestations of Lyme disease. Although it is known that immune reaction of LNB patients is dominated by Th1 and Th2 responses and patients have elevated numbers of B cells in their cerebrospinal fluid (CSF), not all the cells involved in inflammation and cytokine secretion have been characterized. The current diagnostics of LNB is based on intrathecal production of antibodies. In recent years, the measurement of chemokine CXCL13 concentration from the CSF has been introduced as a new promising diagnostic tool for LNB to complement the antibody-based diagnostic methods. A few other cytokines have also been analyzed as possible diagnostic markers. However, multiplex analyses simultaneously evaluating the concentrations of a large number of different cytokines in the CSF of LNB patients have been lacking thus far. Extensive cytokine profiling CSF samples of LNB patients would also help in understanding the complex immunopathogenesis of LNB.Methods: CSF samples were analyzed from 43 LNB patients, 19 controls, 18 tick-borne encephalitis patients, and 31 multiple sclerosis patients. In addition, CSF samples from 23 LNB patients obtained after the antibiotic treatment were examined. Altogether, the concentrations of 49 different cytokines were determined from all of the samples. The concentrations of 48 different cytokines were analyzed by magnetic bead suspension array using the Bio-Plex Pro Human Cytokine 21- and 27-plex panels, and the concentration of CXCL13 was analyzed by an ELISA based method.Results: Distinct cytokine profiles which were able to distinguish LNB patients from controls, tick-borne encephalitis patients, multiple sclerosis patients, and LNB patients treated with antibiotics were identified. LNB patients had elevated concentrations of all major T helper cell type cytokines (Th1, Th2, Th9, Th17, and Treg) in their CSF.Conclusions: Despite the great differences in the CSF cytokine profiles of different patient groups, CXCL13 still remained as the best marker for LNB. However, IL-1ra might also be helpful as a marker for the antibiotic treatment response. Concerning the immunopathogenesis, this is the first report suggesting the involvement of Th9 cells in the immune response of LNB

Collagenolytic and phosphatase activity in the rat mandible after functional protrusion

The effect of chronic mandibular protrusion on the collagenolytic and phosphatase activity of several mandibular bone sites and the condylar cartilage was evaluated. Ninety-three male Sprague-Dawley rats were equally divided into two experimental and one control group. One experimental group wore a protrusive appliance for 2 weeks, the other for 4 weeks. All animals were killed at 59 days of age. Collagenolytic, alkaline and acid phosphatase activities were determined in the condylar cartilage, the subchondral bone and condylar neck, and in the gonial angle and coronoid process. In the cartilage and subchondral bone, the protrusive appliance caused a reduction in collagenolytic and alkaline phosphatase activity. In the condylar neck, it caused a large increase in collagenolytic activity and a decrease in alkaline phosphatase activity in both experimental groups. In the gonial angle and coronoid process, the appliance increased the collagenolytic activity only in the 2-week group. In the 4-week group, the alkaline phosphatase and collagenolytic activities were not different from the activities in those tissues in the control animals. Thus a protrusive appliance induced quantitative changes in enzyme activities in condylar cartilage and mandibular bone. The increase in collagenolytic activity (representing increased bone resorption) occurred typically in areas of muscle attachment and might have been the result of the neuromuscular changes induced by the protrusive appliance. The recovery to normal values of collagenolytic activity in the coronoid process and gonial angle of the 4-week group suggests that at these sites the muscles (and subperiosteal bone) might have adapted to their new biomechanical environment after the longer period of appliance wear.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28165/1/0000617.pd

Dominance of iminopeptidase activity in the human oral bacterium Treponema denticola ATCC 35405

Treponema denticola ATCC 35405, a human oral spirochete associated with periodontal disease, was shown to contain three enzymes (I, II, and III) with proline iminopeptidase activity. II and III were considered to be true iminopeptidases, whereas enzyme I was found to be a benzoylarginine peptidase with iminopeptidase activity. Enzyme III, the dominant proline iminopeptidase of T. denticola in terms of its activity toward N - l -prolyl-2-naphthylamine, was considered to be a sulfhydryl peptidase: 0.167 μ M p -chloromercuribenzoic acid totally inactivated the enzyme, and 1.0 m M dithiothreitol restored 92% of activity. The activity of this enzyme was not affected by metal chelators. Chemical modification of enzyme III suggests that tyrosyl (or histidyl) and carboxyl groups may be necessary for its activity. The hydrolysis of N - l -prolyl-2-naphthylamine was found to be very characteristic of T. denticola ATCC 35405; out of 24 different N - l -aminoacyl-2-naphthylamines tested, only the proline derivative was hydrolyzed at a high rate. The substrate specificity of the enzymes discovered indicates that they may be important for the nutrition of T. denticola . The iminopeptidase activity may be related to the pathogenicity of this organism in periodontal disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41330/1/284_2005_Article_BF01568701.pd

Results of international standardised beekeeper surveys of colony losses for winter 2012-2013 : analysis of winter loss rates and mixed effects modelling of risk factors for winter loss.

This article presents results of an analysis of winter losses of honey bee colonies from 19 mainly European countries, most of which implemented the standardised 2013 COLOSS questionnaire. Generalised linear mixed effects models (GLMMs) were used to investigate the effects of several factors on the risk of colony loss, including different treatments for Varroa destructor, allowing for random effects of beekeeper and region. Both winter and summer treatments were considered, and the most common combinations of treatment and timing were used to define treatment factor levels. Overall and within country colony loss rates are presented. Significant factors in the model were found to be: percentage of young queens in the colonies before winter, extent of queen problems in summer, treatment of the varroa mite, and access by foraging honey bees to oilseed rape and maize. Spatial variation at the beekeeper level is shown across geographical regions using random effects from the fitted models, both before and after allowing for the effect of the significant terms in the model. This spatial variation is considerable

Esidiabetes lisää valtimotautien riskiä – entä hoidon kustannuksia?

Lähtökohdat Esidiabetekseen liittyy suurentunut riski sairastua tyypin 2 diabetekseen sekä sydän- ja ­verisuonitauteihin. Diabeteksen ja sen lisäsairauksien hoitoon liittyy suuria kustannuksia. Menetelmät Esidiabeetikot tunnistettiin terveyskeskuksen potilasrekisteristä poikkeavien ­verensokeriarvojen perusteella. Heidän hoitoaan, lisäsairauksien määrää ja hoidon kustannuksia verrattiin saman alueen tyypin 2 diabeetikoiden ja vertailuryhmän potilaiden hoitoon ja kustannuksiin. Tulokset Esidiabeteksen esiintyvyys oli kaikissa ikäryhmissä lähes kaksinkertainen verrattuna ­tyypin 2 ­diabeteksen esiintyvyyteen. Lisäsairauksien esiintyvyys ja potilaskohtaiset kustannukset olivat e­sidiabeetikoilla suuremmat kuin vertailuryhmän potilailla, mutta pienemmät kuin tyypin 2 diabeetikoilla ­lähes kaikissa ­diagnoosiryhmissä. Päätelmät Esidiabetes ja lisäsairaudet lisäävät hoidon kustannuksia verrattuna potilaisiin, joilla on normaali sokeriaineenvaihdunta. Koska potilasmäärä on suurempi, kokonaiskustannukset ovat jopa suuremmat kuin tyypin 2 diabeetikoilla ja ne painottuvat enemmän erikoissairaanhoitoon. Hoito ja seuranta ei ole yhtä intensiivistä kuin diabeetikoilla.</p

The seeding of ice algal blooms in Arctic pack ice: The multiyear ice seed repository hypothesis

Source at http://dx.doi.org/10.1002/2016JG003668 During the Norwegian young sea ICE expedition (N-ICE2015) from January to June 2015 the pack ice in the Arctic Ocean north of Svalbard was studied during four drifts between 83° and 80°N. This pack ice consisted of a mix of second year, fi rst year, and young ice. The physical properties and ice algal community composition was investigated in the three different ice types during the winter-spring-summer transition. Our results indicate that algae remaining in sea ice that survived the summer melt season are subsequently trapped in the upper layers of the ice column during winter and may function as an algal seed repository. Once the connectivity in the entire ice column is established, as a result of temperature-driven increase in ice porosity during spring, algae in the upper parts of the ice are able to migrate toward the bottom and initiate the ice algal spring bloom. Furthermore, this algal repository might seed the bloom in younger ice formed in adjacent leads. This mechanism was studied in detail for the dominant ice diatom Nitzschia frigida . The proposed seeding mechanism may be compromised due to the disappearance of older ice in the anticipated regime shift toward a seasonally ice-free Arctic Ocean