Sucrose Exposure Research Articles

Cumulative sucrose exposure for repeated procedural pain in preterm neonates and neurodevelopment at 18 months of corrected age: a prospective observational longitudinal study

IntroductionOral sucrose is repeatedly administered to neonates in the neonatal intensive care unit (NICU) to treat pain from commonly performed procedures; however, there is limited evidence on its long-term cumulative...

Taste aversion learning during successive negative contrast

Previous experiments found that acceptance of saccharin by rats was reduced if they had prior experience of sucrose or some other highly palatable solution. This study tested whether such successive negative contrast (SNC) effects involve acquisition of an aversion to the new taste. In three experiments, rats were switched from sucrose exposure in Stage 1 to a less palatable solution containing a new taste in Stage 2. In Experiments 1 and 2, a novel flavor was added to a saccharin solution at the start of Stage 2. In Experiment 1, preference tests revealed a weak aversion to the added vanilla flavor in the Suc-Sacch group, while in Experiment 2 an aversion was found in the Suc-Sacch group to the salty flavor that was used, compared with controls given access either saccharin or water in Stage 1. In Experiment 3, the Suc-Quin group, given quinine solution in Stage 2, displayed a greater aversion to quinine than a Water-Quin control group. These results support the suggestion that taste aversion learning plays a role in the initial suppression of intakes in a qualitative consummatory SNC effect. However, in the light of other evidence, it seems that the unusual persistence of successive negative contrast when rats are switched from sucrose to saccharin is not due to a long-lasting reduction in the value of saccharin.

Nicotine is a potent extracellular polysaccharide inducer in Fusobacterium nucleatum biofilms

The purpose of this in vitro study was to analyze the influence of nicotine on the extracellular polysaccharides in Fusobacterium nucleatum biofilm. Methods: F. nucleatum (ATCC 10953) biofilms supplemented with different concentrations of nicotine (0, 0.5, 1, 2, 4, and 8 mg/mL) were grown in two different BHI broth conditions [no sucrose and 1% sucrose]. Extracellular polysaccharides assay, pH measurements, and a spectrophotometric assay were performed. Data were submitted for ANOVA and Tukey honestly significant difference analyses (HSD) tests (α =.05). Results: Extracellular polysaccharides synthesis was influenced by an interaction between nicotine concentrations and growth medium solution containing sucrose (P<.05). The pH values declined in the sucrose-exposed biofilm were greater than in the group exposed only to nicotine (P<.05). The biofilm exposed to sucrose and nicotine had a higher total biofilm growth (P<.05) than the nicotine-treated biofilm without sucrose. Conclusions: Regardless of sucrose exposure, biofilms exposed to different nicotine concentrations influenced the amount of extracellular polysaccharides.

CO2 laser irradiation combined with fluoridated dentifrice improved its protective effect on caries lesion progression regardless of the acidulated phosphate fluoride gel application: An in situ study.

This in situ study aimed to investigate the efficacy of CO2 laser at a 10.6-µm wavelength combined with 1.23% acidulated phosphate fluoride (APF) and fluoridated dentifrice with 1100µg F/g (FD) to control enamel caries progression. Sixteen volunteers wore palatal appliances containing eight demineralized enamel specimens for four 14-day phases under sucrose exposure. These specimens were submitted to CO2 laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO2 laser, NFD + APF, NFD + CO2 laser + APF, FD, FD + CO2 laser, FD + APF, and FD + CO2 laser + APF. Mineral loss, calcium fluoride (CaF2), fluorapatite (FAp), and fluoride in the biofilm were analyzed by analysis of variance followed by the Student-Newman-Keuls test, p < 0.05. The highest mineral loss inhibition was noted when FD and CO2 laser irradiation were combined, which did not significantly differ from the FD + CO2 laser + APF group. The CaF2, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO2 laser irradiation promoted a slightly higher concentration of CaF2 in the enamel and F in the biofilm. Although APF promotes the high formation of CaF2 and FAp, the combined use of FD with CO2 laser overcomes the APF effect in inhibiting the progression of artificial caries-like lesions in situ. Under the in situ design of this study, remineralization of white spot lesions was achieved through CO2 laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.

Abstract 176: The Pathological Role of Aldose Reductase in Isolated Cardiomyocytes Undergoing Hypoxia / Reoxygenation After Prior Exposure to High Glucose Concentrations

Hyperglycemia increases the vulnerability of the cardiovascular system to ischemia/reperfusion (IR) injury. There are currently no effective therapeutic strategies. We hypothesized that hyperglycemia would increase glucose flux through the polyol pathway. Aldose reductase (AR) catalyzes the first step of this pathway by converting glucose to sorbitol. This reaction generates more oxidative stress due to the depletion of NADPH and osmotic stress caused by sorbitol accumulation, making the heart more susceptible to IR injury. This study aimed to better understand the injury mechanism in cardiomyocytes after high glucose exposure and IR injury. Confluent cardiomyocytes were exposed for 24 hours to 25, 50, or 100 mM glucose or 25 mM glucose with 25 or 75 mM sucrose concentrations added. The non-metabolizable sugar sucrose was used as an osmolarity control. Epalrestat, an AR inhibitor, was added at 0, 1, or 10 μM per well (n = 18 per group) during glucose or sucrose exposure. Cells were then subjected to 24 hours of hypoxic conditions (glucose-, sucrose- and serum-free media; 0.01% O 2 , 37 °C; hypoxic chamber) or normoxic conditions (complete media; 21% O 2 , 37 °C), followed by a 2-hour reoxygenation period in normoxic conditions. Cell injury was quantified by measurement of lactate dehydrogenase (LDH) release. Data were normalized to 25 mM glucose after control/normoxic conditions without AR inhibitor. A three-way ANOVA was conducted to compare groups, followed by the Holm-Šidák test. Increasing glucose concentrations lead to increased cell damage after hypoxia/reoxygenation. Adding the AR inhibitor during the glucose exposure period reduced LDH release after hypoxia/reoxygenation in a dose-dependent manner. The addition of sucrose did not increase cell injury. The AR inhibitor did not affect cells exposed to sucrose. The polyol pathway may play a dominant role in increased cell injury by hyperglycemia after hypoxia/reoxygenation.

Adolescent exposure to sucrose increases cocaine-mediated behaviours in adulthood via Smad3.

Adolescence, a critical period of developmental period, is marked by neurobiological changes influenced by environmental factors. Here, we show how exposure to sucrose, which is ubiquitously available in modern diets, results in changes in behavioural response to cocaine as an adult. Rats were given daily access to either 10% sucrose or water during the adolescent period (PND28-42). Following this period, rats are left undisturbed until they reach adulthood. In adulthood, rats were tested for (i) acquisition of a low dose of cocaine, (ii) progressive ratio (PR) test, and (iii) resistance to punished cocaine taking. Sucrose exposure resulted in significant alterations in all behavioural measures. To determine the neurobiological mechanisms leading to such behavioural adaptations, we find that adolescent sucrose exposure results in an upregulation of the transcription factor Smad3 in the nucleus accumbens (NAc) when compared with water-exposed controls. Transiently blocking the active form of this transcription factor (HSV-dnSmad3) during adolescence mitigated the enhanced cocaine vulnerability-like behaviours observed in adulthood. These findings suggest that prior exposure to sucrose during adolescence can heighten the reinforcing effects of cocaine. Furthermore, they identify the TGF-beta pathway and Smad3 as playing a key role in mediating enduring and long-lasting adaptations that contribute to sucrose-induced susceptibility to cocaine. Taken together, these results have important implications for development and suggest that adolescent sucrose exposure may persistently enhance the susceptibility to substance abuse.

FRI386 Effects Of Maternal Sucrose Intake During Pregnancy On Steroids In The Placenta And Fetal Brain Of Rats

Abstract Disclosure: M.M. Jung: None. D.R. Seib: None. H.W. Chen: None. M. Idrissi: None. K.K. Soma: None. Intake of added sugars such as sucrose (table sugar) is high globally. Many people consume more than 20% of their daily calories as added sugars. High-sucrose consumption alters steroids and the brain. In rats, a human-relevant level of maternal sucrose intake starting 10 weeks before, during, and after pregnancy decreases maternal corticosterone in the serum but increases corticosterone in the blood and brain of the adult female offspring. Similarly, rat dams fed a high-sucrose diet starting 10 weeks before and during gestation have elevated 11-dehydrocorticosterone (DHC) in the serum and amniotic fluid and reduced testosterone and androstenedione in the labyrinth/junctional zone and decidua, respectively. Aldosterone is also elevated in the amniotic fluid, fetal blood, and fetal brain (nucleus accumbens, NAc). Thus, it is clear that maternal sucrose intake alters both maternal and offspring steroids, and has long-term, sex-specific endocrine effects. However, it is unclear how maternal sucrose consumption specifically during pregnancy impacts the offspring development. Our study investigates how maternal sucrose intake during pregnancy affects steroids in the placenta and fetal brain. We hypothesize that maternal sucrose intake is a metabolic stressor that will alter steroid signalling in the placenta and the developing brain. We fed female Long-Evans rats either a high-sucrose diet (26% kcal sucrose) or an isocaloric, macro/micro-nutrient-matched control diet (1% kcal sucrose) starting embryonic day 0 (E0; the day of pregnancy confirmation) (n=15/group). On E19, we collected maternal serum, amniotic fluid, placenta, fetal blood, and fetal brain. We will microdissect the placenta (decidua and labyrinth/junctional zone) and fetal brain (prefrontal cortex, NAc, ventral tegmental area, hippocampus, and hypothalamus) and measure a panel of 15 steroids using highly specific and sensitive liquid chromatography-tandem mass spectrometry. Maternal sucrose intake did not alter maternal food intake, body weight, and litter size, but increased the percentage of male offspring. We are currently analyzing the steroid data. We predict that maternal sucrose intake during pregnancy will increase anti-inflammatory steroids (corticosterone, DHC, and aldosterone) in the maternal blood, amniotic fluid and fetal brain, and decrease androgens in the placenta. We will also measure steroidogenic enzymes in the placenta and fetal brain. Our findings will clarify how maternal sucrose intake impacts both the placenta and fetal development. Moreover, our results will examine whether sucrose exposure during pregnancy is the underlying mechanism for the endocrine effects observed in the fetal and adult offspring. This study will provide more insight into the relationship between nutrition, the nervous system, and the endocrine system. Presentation: Friday, June 16, 2023

Antibacterial, antibiofilm and anticaries effect of BioXtra® mouthrinse for head and neck cancer (HNC) patients under a microcosm biofilm model

Background and purposeConsidering the lack of studies investigating salivary substitutes to control post-radiation caries for patients with head and neck cancer (HNC), this study aimed to evaluate the antibacterial, antibiofilm, and anticaries effects of BioXtra® on the microcosm biofilm formed on different enamel types (non-irradiated and irradiated) and from distinct saliva sources (control and HNC patients). Materials and methodsNon-irradiated and irradiated enamel specimens were treated with BioXtra®, phosphate-buffered-saline (PBS; negative control), or 0.12% chlorhexidine (CHX; positive control) for 1 min. Biofilm was produced from human saliva (healthy participants with normal salivary flow for the control group or irradiated HNC patients with hyposalivation for the HNC group), mixed with McBain saliva, under 0.2% sucrose exposure, daily submitted to the treatments (1 min), for 5 days. Bacterial metabolic activity, biofilm viability, CFU counting, and enamel demineralization were determined. ResultsBioXtra® significantly reduced the bacterial metabolic activity for both enamel types and the inoculum sources, being more effective for the irradiated enamel or for the saliva from the control group. Similarly, BioXtra® significantly reduced the biofilm viability, the CFU for total microorganisms, mutans streptococci, and lactobacilli, and was able to significantly reduce the mineral loss and the lesion depth compared to PBS. CHX was an effective treatment to significantly reduce all parameters, performing better than BioXtra® and reinforcing its reliable efficiency as a positive control. ConclusionRegardless of the enamel type and the inoculum source, BioXtra® presented antibacterial, antibiofilm, and anticaries effects under this experimental model, which should be confirmed in further clinical studies.

1664-P: High Fat High Sucrose Exposure during Lactation but Not during the Post-Weaning Period Programs Impaired Glucose Homeostasis

Nutrition during critical developmental windows plays a pivotal role in shaping long-term metabolic health. Exposure to a Western diet in early life may lead to altered metabolic programing, potentially influencing the risk to develop obesity and type 2 diabetes. In particular, an early exposure to an obesogenic diet may induce a metabolic program that only emerges upon dietary challenges later in life. Accordingly, understanding the long-term impact of nutritional insults in different stages of early life may provide strategies for primary prevention. Therefore, the present study aimed to determine which time window in the post-natal period is most critical for long-term metabolic health. To this end, pups born to lean mouse dams were exposed to a high-fat-high-sucrose (HFHS) diet for 3 weeks during lactation or in the post-weaning period. Thereafter, mice were either fed a regular chow diet until the age of 30 weeks or exposed to a second bout of HFHS diet for the last 12 weeks. Metabolic health and development of obesity was assessed by regular monitoring of glucose homeostasis and body weight gain. At the age of 12 weeks, mice with lactational exposure to a HFHS diet revealed a significantly impaired glucose tolerance compared to control mice, while glucose tolerance of post-weaning exposed mice was similar to the control group. Moreover, a second bout of HFHS diet impaired glucose tolerance and increased body and adipose tissue weight in mice with lactational exposure to a significant greater extent than in post-weaning exposed mice. Preliminary data suggests that increased adipose tissue inflammation might be mechanistically involved in impaired glucose tolerance of lactation exposed mice. Hence, exposure to HFHS during lactation but not during the post-weaning period programs impaired glucose homeostasis, suggesting that the lactational window may be the most critical in terms of metabolic programing. Disclosure A.Goergen: None. S.Wueest: None. D.Konrad: Research Support; Novo Nordisk A/S.

Influence of Different Types of Carbon Sources on Glucosinolate and Phenolic Compounds in Radish Sprouts

Radish sprouts are valued as a key nutrient-dense food in Asian countries. In the current study, we examined how radish sprouts responded to treatments with various carbon sources. The influence of those treatments in parameters such as plant growth and glucosinolate and phenolic compounds levels were analyzed. A positive correlation between plant growth and the accumulation of glucosinolates and phenolics was observed. In this study, except for galactose treatment, all other carbon-exposed radish sprouts showed the highest shoot and root length and fresh weight. Seven different glucosinolate and five phenolic compounds were identified in radish sprouts. The total glucosinolates and phenolic compound content were increased after treatments with different carbon sources. Radish sprouts exposed to sucrose showed the highest total glucosinolates and phenolics content, which was 1.22-fold and 1.45-fold higher than that of untreated sprouts, respectively. Moreover, sucrose exposure led to a higher production of glucoiberin, gluconapoleiferin, 4-hydroxyglucobrassicin, glucoerucin, glucoraphasatin, glucobrassicin, gallic acid, sinapic acid, rutin, and p-coumaric acid compared to that of untreated sprouts. The results obtained in this study will be helpful for researchers around the world to enhance specific glucosinolate and phenolic compounds by treating the radish sprout plants with suitable carbon sources.

Soybean Root Transcriptomics: Insights into Sucrose Signaling at the Crossroads of Nutrient Deficiency and Biotic Stress Responses.

Soybean (Glycine max) is an important agricultural crop, but nutrient deficiencies frequently limit soybean production. While research has advanced our understanding of plant responses to long-term nutrient deficiencies, less is known about the signaling pathways and immediate responses to certain nutrient deficiencies, such as Pi and Fe deficiencies. Recent studies have shown that sucrose acts as a long-distance signal that is sent in increased concentrations from the shoot to the root in response to various nutrient deficiencies. Here, we mimicked nutrient deficiency-induced sucrose signaling by adding sucrose directly to the roots. To unravel transcriptomic responses to sucrose acting as a signal, we performed Illumina RNA-sequencing of soybean roots treated with sucrose for 20 min and 40 min, compared to non-sucrose-treated controls. We obtained a total of 260 million paired-end reads, mapping to 61,675 soybean genes, some of which are novel (not yet annotated) transcripts. Of these, 358 genes were upregulated after 20 min, and 2416 were upregulated after 40 min of sucrose exposure. GO (gene ontology) analysis revealed a high proportion of sucrose-induced genes involved in signal transduction, particularly hormone, ROS (reactive oxygen species), and calcium signaling, in addition to regulation of transcription. In addition, GO enrichment analysis indicates that sucrose triggers crosstalk between biotic and abiotic stress responses.

The effects of sucrose and arsenic on muscular insulin signaling pathways differ between the gastrocnemius and quadriceps muscles.

Insulin resistance in muscle can originate from a sedentary lifestyle, hypercaloric diets, or exposure to endocrine-disrupting pollutants such as arsenic. In skeletal muscle, insulin stimulates glucose uptake by translocating GLUT4 to the sarcolemma. This study aimed to evaluate the alterations induced by sucrose and arsenic exposure in vivo on the pathways involved in insulinstimulated GLUT4 translocation in the quadriceps and gastrocnemius muscles. Male Wistar rats were treated with 20% sucrose (S), 50 ppm sodium arsenite (A), or both (A+S) in drinking water for 8 weeks. We conducted an intraperitoneal insulin tolerance (ITT) test on the seventh week of treatment. The quadriceps and gastrocnemius muscles were obtained after overnight fasting or 30 min after intraperitoneal insulin injection. We assessed changes in GLUT4 translocation to the sarcolemma by cell fractionation and abundance of the proteins involved in GLUT4 translocation by Western blot. Male rats consuming S and A+S gained more weight than control and Atreated animals. Rats consuming S, A, and A+S developed insulin resistance assessed through ITT. Neither treatments nor insulin stimulation in the quadriceps produced changes in GLUT4 levels in the sarcolemma and Akt phosphorylation. Conversely, A and A+S decreased protein expression of Tether containing UBX domain for GLUT4 (TUG), and A alone increased calpain-10 expression. All treatments reduced this muscle's protein levels of VAMP2. Conversely, S and A treatment increased basal GLUT4 levels in the sarcolemma of the gastrocnemius, while all treatments inhibited insulin-induced GLUT4 translocation. These effects correlated with lower basal levels of TUG and impaired insulin-stimulated TUG proteolysis. Moreover, animals treated with S had reduced calpain-10 protein levels in this muscle, while A and A+S inhibited insulin-induced Akt phosphorylation. Arsenic and sucrose induce systemic insulin resistance due to defects in GLUT4 translocation induced by insulin. These defects depend on which muscle is being analyzed, in the quadriceps there were defects in GLUT4 retention and docking while in the gastrocnemius the Akt pathway was impacted by arsenic and the proteolytic pathway was impaired by arsenic and sucrose.

The effects of sucrose and arsenic on muscular insulin signaling pathway differ between gastrocnemius and quadriceps muscles

Background: Muscle insulin resistance can originate from a sedentary lifestyle, hypercaloric diets or, the exposure to endocrine-disrupting pollutants such as arsenic. In skeletal muscle, insulin stimulates glucose uptake by translocating GLUT4 to the sarcolemma. This study aimed to evaluate the alterations induced by sucrose and arsenic exposure in vivo on the pathways involved in insulin-stimulated GLUT4 translocation in the quadriceps and gastrocnemius muscles. Methods: Male Wistar rats were treated with 20 % sucrose (S), 50 mg/L sodium arsenite (A), or both (A+S) in drinking water for 8 weeks. The intraperitoneal insulin tolerance (ITT) test was on the seventh week of treatment. Quadriceps and gastrocnemius muscles were obtained after overnight fasting or after 30 min of intraperitoneal insulin injection. We assessed changes in GLUT4 translocation to the sarcolemma by cell fractionation and abundance of the proteins involved in GLUT4 translocation by Western blot. Results: Male rats consuming S and A+S gained more weight than control and A-treated animals. Rats consuming S, A, and A+S developed insulin resistance assessed through ITT. Neither treatments nor insulin stimulation in the quadriceps produced changes in GLUT4 levels in sarcolemma and Akt phosphorylation. Conversely, A and A+S decreased protein expression of Tether containing Ubx domain for GLUT4 (TUG), and A alone increased calpain-10 expression. All treatments reduced this muscle's protein levels of VAMP2. Conversely, S and A-treatment increased basal GLUT4 levels in the sarcolemma of the gastrocnemius, while all treatments inhibited insulin-induced GLUT4 translocation. These effects correlated with lower basal levels of TUG and impaired insulin-stimulated TUG proteolysis. Moreover, animals treated with S had reduced capn10 protein levels in this muscle, while A and A+S inhibited insulin-induced Akt phosphorylation. Conclusion: Arsenic and sucrose act through different pathways to impair GLUT4 trafficking, and the effects differ between the quadriceps and gastrocnemius. CONACYT-Fronteras #568492, DGAPA-PAPIIT-UNAM #IN20872 and DGAPA-PAPIIT-UNAM #IN205621 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Whole-brain tracking of cocaine and sugar rewards processing

Natural rewards, such as food, and sex are appetitive stimuli available for animals in their natural environment. Similarly, addictive rewards such as drugs of abuse possess strong, positive valence, but their action relies on their pharmacological properties. Nevertheless, it is believed that both of these kinds of rewards activate similar brain circuitry. The present study aimed to discover which parts of the brain process the experience of natural and addictive rewards. To holistically address this question, we used a single-cell whole-brain imaging approach to find patterns of activation for acute and prolonged sucrose and cocaine exposure. We analyzed almost 400 brain structures and created a brain-wide map of specific, c-Fos-positive neurons engaged by these rewards. Acute but not prolonged sucrose exposure triggered a massive c-Fos expression throughout the brain. Cocaine exposure on the other hand potentiated c-Fos expression with prolonged use, engaging more structures than sucrose treatment. The functional connectivity analysis unraveled an increase in brain modularity after the initial exposure to both types of rewards. This modularity was increased after repeated cocaine, but not sucrose, intake. To check whether discrepancies between the processing of both types of rewards can be found on a cellular level, we further studied the nucleus accumbens, one of the most strongly activated brain structures by both sucrose and cocaine experience. We found a high overlap between natural and addictive rewards on the level of c-Fos expression. Electrophysiological measurements of cellular correlates of synaptic plasticity revealed that natural and addictive rewards alike induce the accumulation of silent synapses. These results strengthen the hypothesis that in the nucleus accumbens drugs of abuse cause maladaptive neuronal plasticity in the circuitry that typically processes natural rewards.

Habituation of Sugar-Induced Proboscis Extension Reflex and Yeast-Induced Habituation Override in Drosophila melanogaster.

Habituation, the process by which animals learn to ignore insignificant stimuli, facilitates engagement with salient features of the environment. However, neural mechanisms underlying habituation also allow responses to familiar stimuli to be reinstated when such stimuli become potentially significant. Thus, the habituated state must allow a mechanism for habituation override. The remarkably precise knowledge of cell identity, connectivity, and information coding in Drosophila sensory circuits, as well as the availability of tools to genetically target these cells, makes Drosophila a valuable and important organism for analysis of habituation and habituation-override mechanisms. Studies of olfactory and gustatory habituation in Drosophila suggest that potentiation of GABAergic neurons underlies certain timescales of habituation and have specified some elements of a gustatory habituation-override pathway. More detailed understanding of gustatory habituation and habituation-override mechanisms will benefit from access to robust behavioral assays for (a) the proboscis extension reflex (PER) elicited by a sweet stimulus, (b) exposure paradigms that result in PER habituation, and, most critically, (c) manipulations that result in PER-habituation override. Here, we describe simple protocols for persistent sucrose exposure of tarsal hairs that lead to habituation of proboscis extension and for presentation of a novel appetitive stimuli that reinstate robust PER to habituated flies. This detailed protocol of gustatory habituation provides (a) a simple method to induce habituation by continuous exposure of the flies to sucrose for 10 min without leading to ingestion and (b) a novel method to override habituation by presenting yeast to the proboscis. Key features • A protocol for stimulation of Drosophila's taste (sugar) sensory neurons that induces gustatory habituation without satiation due to ingestion. • A chemical (yeast) stimulation protocol that rapidly induces habituation override/dishabituation in sugar-habituated Drosophila.

Activity of Sodium Trimetaphosphate Nanoparticles on Cariogenic-Related Biofilms In Vitro.

In light of the promising effect of sodium trimetaphosphate nanoparticles (TMPn) on dental enamel, in addition to the scarce evidence of the effects of these nanoparticles on biofilms, this study evaluated the activity of TMPn with/without fluoride (F) on the pH, inorganic composition and extracellular matrix (ECM) components of dual-species biofilms of Streptococcus mutans and Candida albicans. The biofilms were cultivated in artificial saliva in microtiter plates and treated with solutions containing 1% or 3% conventional/microparticulate TMP (TMPm) or TMPn, with or without F. After the last treatment, the protein and carbohydrate content of the ECM was analyzed, and the pH and F, calcium (Ca), phosphorus (P), and TMP concentrations of the biofilms were determined. In another set of experiments, after the last treatment, the biofilms were exposed to a 20% sucrose solution, and their matrix composition, pH, and inorganic component contents were evaluated. 3% TMPn/F significantly reduced ECM carbohydrate and increased biofilm pH (after sucrose exposure) than other treatments. Also, it significantly increased P and F levels before sucrose exposure in comparison to 3% TMPm/F. In conclusion, 3% TMPn/F affected the biofilm ECM and pH, besides influencing inorganic biofilm composition by increasing P and F levels in the biofilm fluid.

Long-Term Memory Function Impairments following Sucrose Exposure in Juvenile versus Adult Rats.

We previously described that excessive consumption of sucrose during youth produces fear memory and anxiety-like behavior in adulthood. Here, we evaluated whether high cognitive function is also affected by studying early sucrose consumption in object recognition memory (NOR). Male Sprague Dawley rats were tested for short-term, long-term, and consolidated NOR after 25 days of unlimited sucrose access in juvenile (PD 25-50) or adult age (PD 75-100). All rats spent equal time exploring the two objects during the sample phase T1. When animals were exposed for 2, 24 h or 7 days later to a copy of the objects presented in T1 and a novel object, the sucrose-exposed juvenile group failed to distinguish between the familiar and the novel objects in contrast with the rest of the groups. Sucrose-exposed animals developed hypertriglyceridemia and glucose intolerance, but juvenile animals showed increased fasting glycemia and sustained the glucose intolerance longer. Moreover, sucrose decreased hippocampal proBDNF expression in juveniles while it was increased in adults, and sucrose also increased RAGE expression in adults. The NOR exploration ratio correlated negatively with basal glycemia and positively with proBDNF. Taken together, these data suggest that sucrose-induced alterations in glucose metabolism may contribute to a long-term decline in proBDNF and impaired recognition memory.

Cymbopogon citratus Essential Oil Increases the Effect of Digluconate Chlorhexidine on Microcosm Biofilms.

The aim of this study was to evaluate the effect of the Cymbopogon citratus essential oil and its association with chlorhexidine on cariogenic microcosm biofilm composition and acidogenicity. Minimum inhibitory and bactericide concentrations from the essential oil and chlorhexidine were determined by broth microdilution assay. Microcosms (polymicrobial) biofilms were produced on glass coverslips, using inoculum from human saliva in McBain culture medium (0.5% sucrose exposure for 6 h/day) for 3 days in 24-well plates. The biofilms were treated twice a day and their composition was evaluated by microorganism quantification. The acidogenicity was evaluated by measuring the pH of the spent culture medium in contact with the biofilm. Overall, the association of C. citratus and chlorhexidine reduced total bacterial counts and aciduric bacteria (maximum reduction of 3.55 log UFC/mL) in microcosm biofilms. This group also presented the lowest acidogenicity even when exposed to sucrose-containing medium. C. citratus essential oil increases the effect of digluconate chlorhexidine on microcosm biofilms. Based on these findings, this study can contribute to the development of new formulations that might allow for the use of mouthwashes for a shorter period, which may reduce undesirable effects and increase patient compliance to the treatment.

Early childhood caries, obesity and anthropometric measurements: Is there a relationship?

This brief research report explored the relationship among obesity, anthropometric measurements, and early childhood caries (ECC), in 3–5 years-old children. Three hundred and ninety-one Brazilian preschoolers were given anthropometric examinations for the assessment of general, peripheral, and central adiposity, by the following measures: body mass index (BMI), hip circumference, and waist circumference. Obesity status was determined by BMI according to WHO standards. Parent's age and BMI were assessed by questionnaire, and sucrose exposure was tracked by means of a food diary. For the assessment of ECC, dental examinations were performed according to modified WHO criteria. Also, the presence of dental biofilm in maxillary incisors was detected. A direct association between BMI and ECC was found in the bivariate analysis and the best possibility of logistic regression model showed that hip circumference (HC) values ≥62 centimeters (OR = 1.63; p = 0.033) jointly with the presence of dental biofilm (OR = 2.38; p = 0.000), children's ages ≥37 months (OR = 5.09; p = 0.012), and mothers younger than 35 years (OR = 1.96; p = 0.004) were significantly connected with ECC. In conclusion, peripheral adiposity (represented by HC) in young children was in fact associated with ECC. Thus, hip circumference might be a valuable tool for exploring the relationship between caries and obesity in the early years of life.

Effect of experimental and commercial artificial saliva formulations on the activity and viability of microcosm biofilm and on enamel demineralization for irradiated patients with head and neck cancer (HNC)

The effect of different artificial saliva formulations on biofilm activity and viability, and on enamel demineralization for head and neck cancer (HNC) patients was evaluated. Irradiated enamel samples were treated (1 min) with BioXtra® or with experimental formulations containing carboxymethylcellulose plus inorganic constituents alone (AS) or containing 0.1 mg mL−1 CaneCPI-5 (AS + Cane), 1.0 mg mL−1 hemoglobin (AS + Hb) or combination of both (AS + Cane + Hb). Phosphate-buffered-saline and chlorhexidine (0.12%) were negative and positive control, respectively. Biofilm was produced from the saliva of five male HNC patients, under 0.2% sucrose exposure for 5 days, and daily treated with the formulations (1 min). No significant effects were observed for the different experimental treatments. BioXtra® significantly reduced lactobacilli, demonstrating antibacterial potential for this group. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent. Future in vitro studies must be performed using a new approach for the design of the experimental formulations.