Reduced Mastication Impairs Memory Function

Mastication is an indispensable oral function related to physical, mental, and social health throughout life. The elderly tend to have a masticatory dysfunction due to tooth loss and fragility in the masticatory muscles with aging, potentially resulting in impaired cognitive function. Masticatory stimulation has influence on the development of the central nervous system (CNS) as well as the growth of maxillofacial tissue in children. Although the relationship between mastication and cognitive function is potentially important in the growth period, the cellular and molecular mechanisms have not been sufficiently elucidated. Here, we show that the reduced mastication resulted in impaired spatial memory and learning function owing to the morphological change and decreased activity in the hippocampus. We used an in vivo model for reduced masticatory stimuli, in which juvenile mice were fed with powder diet and found that masticatory stimulation during the growth period positively regulated long-term spatial memory to promote cognitive function. The functional linkage between mastication and brain was validated by the decrease in neurons, neurogenesis, neuronal activity, and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. These findings taken together provide in vivo evidence for a functional linkage between mastication and cognitive function in the growth period, suggesting a need for novel therapeutic strategies in masticatory function-related cognitive dysfunction.

Outcomes of grafting intrasynovial tendons of the toes to the hands in 10 patients: a preliminary report

Ten patients had intrasynovial tendon grafting harvested from the toes for secondary flexor tendon reconstruction in nine fingers and one thumb in our institutes from 2009 to 2014. These patients were followed for a mean of 15 (range: 8-36) months. The ranges of total active motion of the proximal and distal interphalangeal joints of these nine fingers were 143° (range: 108-175°) and of the metacarpophalangeal and interphalangeal joints of one thumb were 110°. In conclusion, this technique is feasible and gives a good result when successful but with a high complication rate. Level of Evidence IV.

Re-Examination of Arousing and De-Arousing Effects of Cigarette Smoking

An attempt was made to replicate arousing and de-arousing effects of cigarette smoking originally reported by Golding and Mangan. Changes in electrodermal activity, heart rate, and magnitude in the EEG alpha (7.5—11.5 Hz) and beta (13.5—20 Hz) bands were measured under conditions of both mild sensory isolation as well as stress induced by loud white-noise. Under both conditions, real smoking as well as sham smoking an unlit cigarette increased beta activity and the skin potential response. In contrast, only real smoking produced a significant increase in heart rate, decrease in alpha activity, and increase in skin potential. De-arousing effects reported by Golding and Mangan for white-noise stress were not replicated.

Abstract P5-16-10: Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial

BACKGROUND and AIM:

Findings from a randomized phase 2 JONIE1 trial in women with HER2-negative early breast cancer have shown that the addition of zoledronic acid (ZOL) to neoadjuvant chemotherapy (CT) has potential anticancer benefits in postmenopausal and triple-negative breast cancer patients. We report the data for the prespecified secondary endpoint of disease-free survival (DFS).

METHODS:

We enrolled women with HER2-negative early breast cancer and randomly assigned them to receive CT or CT+ZOL (CTZ). All patients received 4 cycles of FEC100 (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2), followed by 12 cycles of paclitaxel at 80 mg/m2 weekly. ZOL (4 mg) was administered 3-4 times weekly for 7 weeks to the CTZ group patients. Definitive surgery was performed 3-4 weeks after the last paclitaxel dose. The primary endpoint was pathological complete response (pCR). The secondary endpoints were the clinical response rates, rate of breast-conserving surgery, safety, and DFS (defined as the time from randomization to disease occurrence or death). The trial is registered as UMIN000003261 (www.umin.ac.jp/english/) with ongoing follow-up.

FINDINGS:

Of the 188 patients enrolled, 95 were assigned to the CT group and 93 to the CTZ group. The mean (95% CI) DFS time of the CT group was 5.15 years (4.83-5.47) and that of the CTZ group was 5.38 years (5.11-5.66). The 3-year DFS rate was 84.6% (95% CI 77.2-92.0) in the CT group and 90.7% (84.6-96.8) in the CTZ group with no significant difference (p = 0.120). The particular benefit from ZOL for the neoadjuvant CT seen as improvement of the pCR rate was indicated in the 3-year DFS period for triple-negative cancer cases (CT vs CTZ: 70.6% vs 94.1%), but not for postmenopausal cases.

CONCLUSIONS:

ZOL slightly improved DFS when combined with CT. Although a significant difference was not found in this study, plans are underway for conducting a combined analysis of 3 neoadjuvant CT trials together with ZOL. The improvement of the pCR rate may be associated with DFS in triple-negative cases. Previous studies have shown that ZOL was more efficacious in an estrogen-suppressed condition. However, the short-term application of ZOL in this study may not be sufficient to improve the outcome in postmenopausal patients.

Citation Format: Ishikawa T, Akazawa K, Hasegawa Y, Tanino H, Horiguchi J, Miura D, Hayashi M, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Kohno N. Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-10.

Reduction in chlorhexidine efficacy against multi-drug-resistant Acinetobacter baumannii international clone II

BACKGROUND

Nosocomial infections caused by Acinetobacter baumannii international clone II (IC II) can cause severe clinical outcomes.

AIM

Differential evaluation of bactericidal efficacy of chlorhexidine gluconate (CHX) and benzethonium chloride (BZT) disinfectants against IC II and non-IC II isolates.

METHODS

Minimum inhibitory concentrations (MICs) of CHX and BZT were determined for 137 A. baumannii IC II, 99 non-IC II and 69 non-baumannii isolates, further classified according to MIC values into disinfectant-reduced susceptible (DRS) and disinfectant-susceptible (DS) groups. Time-kill curves and minimum bactericidal concentrations (MBCs) were evaluated for representative isolates in each group.

RESULTS

CHX and BZT MIC₉₀s for IC II isolates were 100 and 175mg/L, respectively, but those for non-IC II and non-baumannii isolates were <100mg/L. Nevertheless, time-kill curves indicated that CHX and BZT reduced live bacterial cell number by 5 log₁₀ for IC II and non-IC II isolates within 30s when used at 1000mg/L, comparable to practical use concentrations. CHX MBC at 30s was 1000mg/L for IC II and non-IC II isolates, and was not influenced by addition of 3% bovine serum albumin (BSA); BZT MBC at 30s was 100mg/L without BSA and increased up to 500mg/L upon addition of BSA. No significant differences in BSA were found between DRS and DS isolates.

CONCLUSION

CHX and BZT were effective against Acinetobacter spp. including IC II at a concentration of 1000mg/L and exposure for at least 30s, but their concentrations should be considered carefully to ensure sufficient effects in both clinical and healthcare settings.

Allosteric Inhibitors against HIV-1 Reverse Transcriptase: Design and Synthesis of MKC-442 Analogues Having an Ω-Functionalized Acyclic Structure

Based on X-ray crystallographic analysis of MKC-442/human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) complex, analogues in which the N1-substituent is replaced with ω-functionalized alkyl groups were designed to improve the affinity for the enzyme. Synthesis of these compounds was carried out starting from MKC-442 by a sequence of reactions (N3-protection, removal of N1-ethoxymethyl group, alkylation, and N3-deprotection). The compounds were evaluated for anti-HIV activity. Structure–activity relationships are discussed in terms of the possible interaction with the enzyme.

Development of a Cavity Disinfectant Containing Antibacterial Monomer MDPB

An experimental cavity disinfectant (ACC) that is intended to be used for various direct and indirect restorations was prepared by adding an antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB) at 5% into 80% ethanol. The antibacterial effectiveness of ACC and its influences on the bonding abilities of resin cements were investigated. To examine the antibacterial activity of unpolymerized MDPB, the minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined for Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Parvimonas micra, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis. Antibacterial activities of ACC and the commercial cavity disinfectant containing 2% chlorhexidine and ethanol (CPS) were evaluated by agar disk diffusion tests through 7 bacterial species and by MIC and MBC measurement for S. mutans. The effects of ACC and CPS to kill bacteria in dentinal tubules were compared with an S. mutans–infected dentin model. Shear bond strength tests were used to examine the influences of ACC on the dentin-bonding abilities of a self-adhesive resin cement and a dual-cure resin cement used with a primer. Unpolymerized MDPB showed strong antibacterial activity against 7 oral bacteria. ACC produced inhibition zones against all bacterial species similar to CPS. For ACC and CPS, the MIC value for S. mutans was identical, and the MBC was similar with only a 1-step dilution difference (1:2). Treatment of infected dentin with ACC resulted in significantly greater bactericidal effects than CPS ( P < 0.05, analysis of variance and Tukey’s honest significant difference test). ACC showed no negative influences on the bonding abilities to dentin for both resin cements, while CPS reduced the bond strength of the self-adhesive resin cement ( P < 0.05). This study clarified that the experimental cavity disinfectant containing 5% MDPB is more effective in vitro than the commercially available chlorhexidine solution to eradicate bacteria in dentin, without causing any adverse influences on the bonding abilities of resinous luting cements.

Evaluation of the pharmacokinetic parameters of standard oral antibiotics in a bioequivalence study of generic products

Pharmacokinetic parameters were summarized in clinical bioequivalence studies in Japan to confirm the validity for the use of parameters obtained from the clinical studies. Pharmacokinetic parameters, including maximum plasma/serum concentrations (Cmax), area under the plasma/serum drug concentration-time curve (AUC), time to achieve Cmax (Tmax), and half life (t1/2), of the standard products (original drugs) after oral administration of antimicrobials, including respiratory quinolones, cephalosporins, macrolides, and penicillin-based antibiotics were investigated by use of interview forms and/or package inserts from the generic products and the relationship among the pharmacokinetic parameters such as Cmax, AUC, Tmax, and t1/2 were estimated. In all the studies, the standard and generic products were administrated orally to healthy fasting subjects. Although there was more than a 1.5-fold difference in the Cmax and AUC0-24 h, but not in the Tmax and t1/2 values for levofloxacin tablets and cefacrol tablets, these parameters for other antibiotics were similar in various studies. The obtained results suggested that the parameters obtained from recent bioequivalence studies would be useful in identifying pharmacokinetic behavior of the original drugs, especially early time release; however, the pharmacokinetic results obtained from the recently conducted bioequivalence studies may be superior to those obtained from studies conducted in the past.

Systemic and Eosinophilic Lesions in Rats with Spontaneous Eosinophilia (mes Rats)

The mes rat is from an inbred mutant colony of rats with spontaneous eosinophilia. In order to investigate the pathogenesis of the mes rat, the histopathology and hematology for 76 mes rats were examined at several weeks of age. Tissue eosinophilia developed at 8 weeks of age when the blood eosinophil was 500 cells per microliter or more. Subsequently, eosinophilia progressed with age, and splenic eosinophilopoiesis and erythropoiesis appeared simultaneously. Many inflammatory lesions were induced after 10 weeks of age when the blood eosinophils became 1,000 cells per microliter or more. Gastroenteritis and mesenteric lymphadenitis were seen in 44 of 47 (94%) and 31 of 47 (66%) rats, respectively, after 10 weeks of age. Aortitis that deteriorated with age was found in 19 of 39 (49%) rats after 12 weeks of age. Hepatic fibrosis was found in four rats that exhibited severe eosinophilia and anemia. These results are comparable to the features of a hypereosinophilic syndrome in humans and other animals.

Do Recent Advances in MR Technologies Contribute to Better Gamma Knife Radiosurgery Treatment Results for Brain Metastases?

The detection of intracerebral lesions has improved greatly with advancements in MR imaging, especially the greater sensitivity of the 1.5 Tesla unit versus the older 1.0 Tesla unit. We aimed to determine whether improvements in MR imaging have actually improved diagnostic capabilities and treatment outcomes in gamma knife radiosurgery (GKRS) for brain metastases (METs). Ours was a retrospective study of a consecutive series of 1179 patients (441 females, 738 males, mean age: 63 years, range: 19–92 years) with brain METs who underwent GKRS from 1998 to 2004. Our treatment policy was to irradiate all lesions visible on MR images during a single GKRS session. Mean and median tumor numbers were seven and three (range; 1–74). The 1179 patients were divided into two groups: a 1.0 T-group of 660 patients examined using a 1.0 Tesla MR unit before August, 2002, and a 1.5 T-group of 519 examined using a 1.5 Tesla MR unit after September 2002. In the 1.5 T-group, lesion volumes as small as 0.004 cc were detected with a 5 mm slice thickness. The corresponding lesion size was 0.013 cc in the 1.0 T-group. One or more lesions invisible on a 5 mm slice study were additionally detected on a 2 mm slice study in 47.8% of patients in the 1.0 T-group and 25.2% in the 1.5 T-group (p<.0001). The median survival time (MST) in the 1.5 T-group was significantly longer than that in the 1.0 T-group (8.4 vs. 6.3 months, p=.0004). Due to biases in patient numbers between the two groups, we analyzed subgroups with KPS of 80% or better, no neurological deficits, stable primary tumors, lung cancer, tumor numbers of four or less and tumor volumes of 10.0 cc or smaller. In every subgroup analysis, the MSTs of the 1.5-Tesla group were significantly longer than those of the 1.0-Tesla group. The prognosis of a cancer patient is undoubtedly influenced by multiple factors. Nevertheless, we conclude that application of the 1.5 Tesla MR unit has had a favorable impact on diagnosis and GKRS treatment results in patients with brain METs.

Skin pigmentation is inversely associated with insulin resistance in healthy Japanese women

AIM

As a low-pigment skin type is prevalent in men and women with type 1 diabetes, it is possible that skin pigmentation may be associated with insulin resistance. This study aimed to cross-sectionally examine this association in healthy women.

METHODS

Study participants were 792 Japanese women who attended a health examination and were not taking any medication for diabetes. Skin pigmentation on the inner upper and lower arms and forehead was measured using a Mexameter^® skin colorimeter, a narrow-band reflective spectrophotometer. Data are expressed as a melanin index, which quantifies melanin content. Fasting blood glucose and insulin levels were also measured, and homoeostasis model assessment for insulin resistance (HOMA-IR) scores were calculated. Information on medical history and lifestyle factors were obtained by a self-administered questionnaire, while data on sun exposure were collected through interviews. Plasma 25-hydroxyvitamin D levels were measured in a subsample of women (n=464).

RESULTS

Melanin indices at the inner upper and lower arms were significantly and inversely associated with fasting insulin levels and HOMA-IR after controlling for age, body mass index, smoking status, indicators for rater effects, cumulative sun exposure and season at the time of measurement. Additional adjustment for plasma 25-hydroxyvitamin D levels did not alter the results.

CONCLUSION

These data suggest that skin pigmentation is associated with insulin resistance, and encourage future studies into the potential role of melanin and related factors in glucose homoeostasis.