Effect of Probiotic Yogurt and Xylitol-Containing Chewing Gums on Salivary S Mutans Count.

BACKGROUND AND AIMS: In addition to improving gastrointestinal health and intestinal microflora, probiotic bacteria have been recently suggested to decrease cariogenic agents in the oral cavity. The aim of this study was to investigate the effects of probiotic yogurt and xylitol-containing chewing gums on reducing salivary Streptococcus mutans levels. STUDY DESIGN: This randomized clinical trial recruited 50 female students with over 105 colony forming units S. mutans per milliliter of their saliva. The participants were randomly allocated to two equal groups to receive either probiotic yogurt containing Lactobacillus acidophilus ATCC 4356 andBifidobacteriumbifidum ATCC 29521 (200 g daily) or xylitol-containing chewing gums (two gums three times daily after each meal; total xylitol content: 5.58 g daily) for three weeks. At baseline and one day, two weeks, and four weeks after the interventions, saliva samples were cultured on mitis-salivarius-bacitracin agar and salivary S. mutans counts were determined. Data were analyzed with independent t-tests, analysis of variance, and Fisher's least significant difference test. RESULTS: In both groups, S. mutans counts on the first day, second week, and fourth weeks after the intervention were significantly lower than baseline values (P < 0.05). The greatest level of reduction in both groups was observed in the second week after the intervention. Moreover, although the reduction was greater in probiotic yogurt consumers, the difference between the two groups was not statistically significant. CONCLUSION: Probiotic yogurt and xylitol-containing chewing gums seem to be as effective in reduction of salivary S. mutans levels. Their constant long-term consumption is thus recommended to prevent caries.

Facile preparation of a pH-sensitive biocompatible nanocarrier based on magnetic layered double hydroxides/Cu MOFs-chitosan crosslinked к-carrageenan for controlled doxorubicin delivery to breast cancer cells.

Recently, the biocompatibility of hydrogel nanoparticles has gained considerable research attention in the field of drug delivery. In this regard, we design a pH-controlled nanocarrier based on magnetic layered double hydroxides/copper metal-organic framework-chitosan crosslinked к-carrageenan hydrogel nanoparticles (LDH-Fe3O4/Cu MOF-DOX-CS@CAR) for targeted release from DOX to breast cancer cells. FT-IR, EDX, XRD, FE-SEM, VSM, and Zeta potential investigated the chemical structure of hydrogel nanoparticles. The encapsulation efficiency and drug loading capacity of the DOX were obtained to be 96.1 % and 9.6 %, respectively. The cumulative release of DOX from LDH-Fe3O4/Cu MOF-DOX-CS@CAR at pH 5.5 and 7.4 after 72 h was 60.3 % and 22.6 %, respectively. These in vitro release results confirmed the controlled release and pH-response behavior of hydrogel nanoparticles. Also, the mechanism of DOX release from LDH-Fe3O4/Cu MOF-DOX-CS@CAR hydrogel nanoparticles showed that the Korsmeyer-Peppas model with Fickian diffusion is the best-fitting model for describing the release behavior of DOX from hydrogel nanoparticles. The cellular cytotoxicity and DAPI tests of the prepared LDH and LDH-Fe3O4/Cu MOF toward L929 non-cancerous cells and MCF-7 breast cancer cells confirm its relative biocompatibility and safety. Whereas, LDH-Fe3O4/Cu MOF-DOX-CS@CAR hydrogel nanoparticles toward MCF-7 breast cancer cells had higher cytotoxicity effects due to the targeted and controlled release of DOX to MCF-7 cells. The in vitro DPPH, hemolysis assay, colloidal stability, and enzymatic degradation proved the excellent antioxidant activity (71.81 %), blood compatibility (less than 5 %), better stability, and biodegradation behavior of hydrogel nanoparticles. On these findings, the present study suggests the potential of the prepared LDH-Fe3O4/Cu MOF-DOX-CS@CAR hydrogel nanoparticles as a pH-controlled drug delivery system for cancer treatment and various biomedical uses.

Executive Dysfunction in Klinefelter Syndrome: Associations With Brain Activation and Testicular Failure.

CONTEXT: Executive dysfunction is a well-recognized component of the cognitive phenotype of Klinefelter syndrome (KS), yet the neural basis of KS-associated cognitive weaknesses, and their association with testicular failure is unknown. OBJECTIVE: We investigated executive function, brain activation, and pubertal development in adolescents with and without KS. METHODS: Forty-three adolescents with KS (mean age 12.3 ± 2.3 years) and 41 typically developing boys (mean age 11.9 ± 1.8 years) underwent pubertal evaluation, behavioral assessment, and completed functional magnetic resonance imaging (fMRI) as they performed an executive function task, the go/no-go task. Group differences in activation were examined. Associations among activation, executive function, and pubertal development measures were tested in secondary analyses. RESULTS: Boys with KS exhibited reduced executive function, as well as lower activation in brain regions subserving executive function, including the inferior frontal gyrus, anterior insula, dorsal anterior cingulate cortex, and caudate nucleus. Secondary analyses indicated that the magnitude of activation differences in boys with KS was associated with severity of pubertal developmental delay, as indexed by lower testosterone (t(36) = 2.285; P = .028) and lower testes volume (t(36) = 2.238; P = .031). Greater parent-reported attention difficulties were additionally associated with lower testicular volume (t(36) = -2.028; P = .050). CONCLUSION: These findings indicate a neural basis for executive dysfunction in KS and suggest alterations in pubertal development may contribute to increased severity of this cognitive weakness. Future studies that examine whether these patterns change with testosterone replacement therapy are warranted.

Oral health status, salivary pH status, and Streptococcus mutans counts in dental plaques and saliva of children with acute lymphoblastic leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL), accounting for 23% of all malignancies in children, is the most prevalent pediatric malignancy. This study compared dental caries, oral hygiene status, salivary pH, and Streptococcus mutans counts in dental plaques and saliva of children with leukemia with those of healthy controls. MATERIALS AND METHODS: This case-control cross-sectional study assessed 32 children with ALL and 32 healthy children (4-9-year-old) for gingival bleeding index (GBI), decayed, missing, and filled/decayed, missing, and filled surfaces (DMF/dmfs), and plaque index (PI). Sampling was performed to determine salivary pH and S. mutans counts of the participants. The two groups matched in terms of age, gender, and socioeconomic status. The groups were compared using independent t-test, Mann-Whitney test, Chi-square test, and Spearman's and Pearson's correlation analyses. RESULTS: The mean DMF/dmfs and GBI were significantly higher in the ALL group (PDMF/dmfs= 0.03; PGBI= 0.04). However, the two groups were not significantly different in the mean PI values (P = 0.47). The mean S. mutans counts in dental plaques and saliva of the children with leukemia were significantly lower than the healthy controls (P < 0.01). Moreover, the mean salivary pH was significantly lower in the ALL group compared to the control group (P < 0.01). CONCLUSION: Higher caries and gingival bleeding rates, higher dental plaque accumulation in children with ALL, decreased salivary pH, and cumulative effects of other risk factors highlight the significance of oral hygiene training programs (for the parents of these children) and regular dental examinations for these children.