Analysis of the characteristics of mouthguards that affect isokinetic muscular ability and anaerobic power

PURPOSE

The purpose of this study was to estimate the effects of occlusal stability to identify action mechanisms of mouthguards, known to have a modulatory effect on limb muscle function.

MATERIALS AND METHODS

This study included 20 male subjects to perform the isokinetic muscle tests and the Wingate anaerobic power test on both knee joints under five closed-mouth conditions: without or with 4 types of mouthguards with thickness of 2 mm based on premolar area: (1) full-coverage, (2) anterior partial-coverage, (3) right posterior partial-coverage, and (4) left posterior partial-coverage. The obtained results were subjected to One-way ANOVA with repeated measures, followed by post hoc test of the contrast method (α=.05).

RESULTS

There was no significant difference between the closed position with and without a full-coverage mouthguard in all variables. However, significant differences were observed between with and without a partial-coverage mouthguard in muscular endurance during extension of the left knee, muscular power and endurance during flexion of the right knee. Additionally, significant differences were found between occlusal states with full- and partial-coverage mouthguards in muscular power and endurance during extension of the left knee.

CONCLUSION

These findings indicate the elevation of vertical dimension by 2 mm or the inducement of occlusal stability had little effect on isokinetic muscle strength and anaerobic performance, while uneven distribution of occlusal force might have some positive effects.     

Cognitive emotion regulation strategies contributing to resilience in patients with depression and/or anxiety disorders

Objective

Research suggests that resilience is associated with favorable treatment outcome in patients with depression and/or anxiety disorders. In this regard, the identification of specific characteristics related to resilience that could provide targets for resilience-enhancement interventions is needed. Since the type of cognitive coping strategies is a possible marker of resilience, we investigated adaptive and maladaptive cognitive emotion regulation strategies contributing to resilience in patients with depression and/or anxiety disorders.

Methods

A total of 230 outpatients with depression and anxiety disorders were consecutively recruited and completed the Cognitive Emotion Regulation Questionnaire, the Connor–Davidson Resilience Scale, the Beck Depression Inventory, and the State Anxiety Inventory. A linear regression model was used to determine which cognitive emotion regulation strategies predicted resilience after controlling for relevant covariates. Additionally, this model of resilience was compared with those of depression and anxiety symptoms.

Results

Adaptive strategies were more strongly correlated with resilience than maladaptive strategies. In the regression model, more use of refocus on planning and positive reappraisal as well as less use of rumination predicted high resilience after controlling for age, gender, marital status, depression, and anxiety. Among these strategies, refocus on planning was the common strategy contributing to resilience and depression.

Conclusion

These results suggested that the cognitive emotion regulation strategies of refocus on planning, positive reappraisal, and less rumination contribute to resilience in patients with depression and anxiety disorders. It might provide potential targets for psychotherapeutic intervention to improve resilience in these patients.     

1,25‐Dihydroxyvitamin D Alone Improves Skeletal Growth,Microarchitecture, and Strength in a Murine Model of XLH,Despite Enhanced FGF23 Expression

X‐linked hypophosphatemia (XLH) is characterized by impaired renal tubular reabsorption of phosphate owing to increased circulating FGF23 levels, resulting in rickets in growing children and impaired bone mineralization. Increased FGF23 decreases renal brush border membrane sodium‐dependent phosphate transporter IIa (Npt2a) causing renal phosphate wasting, impairs 1‐α hydroxylation of 25‐hydroxyvitamin D, and induces the vitamin D 24‐hydroxylase, leading to inappropriately low circulating levels of 1,25‐dihydroxyvitamin D (1,25D). The goal of therapy is prevention of rickets and improvement of growth in children by phosphate and 1,25D supplementation. However, this therapy is often complicated by hypercalcemia and nephrocalcinosis and does not always prevent hyperparathyroidism. To determine if 1,25D or blocking FGF23 action can improve the skeletal phenotype without phosphate supplementation, mice with XLH (Hyp) were treated with daily 1,25D repletion, FGF23 antibodies (FGF23Ab), or biweekly high‐dose 1,25D from d2 to d75 without supplemental phosphate. All treatments maintained normocalcemia, increased serum phosphate, and normalized parathyroid hormone levels. They also prevented the loss of Npt2a, α‐Klotho, and pERK1/2 immunoreactivity observed in the kidneys of untreated Hyp mice. Daily treatment with 1,25D decreased urine phosphate losses despite a marked increase in bone FGF23 mRNA and in circulating FGF23 levels. Daily 1,25D was more effective than other treatments in normalizing the growth plate and metaphyseal organization. In addition to being the only therapy that normalized lumbar vertebral height and body weight, daily 1,25D therapy normalized bone geometry and was more effective than FGF23Ab in improving trabecular bone structure. Daily 1,25D and FGF23Ab improved cortical microarchitecture and whole‐bone biomechanical properties more so than biweekly 1,25D. Thus, monotherapy with 1,25D improves growth, skeletal microarchitecture, and bone strength in the absence of phosphate supplementation despite enhancing FGF23 expression, demonstrating that 1,25D has direct beneficial effects on the skeleton in XLH, independent of its role in phosphate homeostasis. © 2016 American Society for Bone and Mineral Research.     

Different pattern of viral infections and clinical outcomes in patient with acute exacerbation of chronic obstructive pulmonary disease and chronic obstructive pulmonary disease with pneumonia

Respiratory viruses are well‐known causes of acute exacerbation of chronic obstructive pulmonary disease (AE‐COPD) and also important pathogens for concomitant pneumonia in COPD (CP‐COPD). However, the differences in a viral infection pattern and clinical impacts of respiratory viruses between the two groups have not been well investigated. The clinical and microbiological data from COPD patients admitted with AE‐COPD (n = 281) or CP‐COPD (n = 284) between January 2010 and December 2012 were reviewed. After excluding 88 patients (40 with AE‐COPD and 48 with CP‐COPD) who did not undergo a multiplex RT‐PCR test for respiratory viruses, the demographic characteristics, identified viruses, and clinical outcomes of the AE‐COPD and CP‐COPD groups were compared. Respiratory viruses were identified in 41.9% of AE‐COPD group and 33.5% of the CP‐COPD groups. The most common virus was influenza virus in the AE‐COPD group (33.7%) versus human coronavirus (24.1%) in the CP‐COPD group. Influenza virus was significantly more common in the AE‐ACOPD group than in the CP‐COPD group (P < 0.01). In‐hospital mortality of AE‐COPD and CP‐COPD were 1.2% and 12.3%, respectively (P < 0.01). Among CP‐COPD patients, in‐hospital mortality of patients with only viral infection group, only bacterial infection group, and viral‐bacterial co‐infection were 2.6%, 25.8%, and 17.5%, respectively (P = 0.01). Respiratory viruses were commonly identified in both AE‐COPD and CP‐COPD, influenza virus and human coronavirus were the most common viruses identified in AE‐COPD and CP‐COPD patients, respectively. The mortality rates of only viral infection group was significantly lower than only bacterial infection or viral‐bacterial co‐infection group in CP‐COPD patients. J. Med. Virol. 88:2092–2099, 2016. © 2016 Wiley Periodicals, Inc.

     

Extrapulmonary small cell carcinoma of the liver: clinicopathological and immunohistochemical findings

Patients with primary small cell carcinoma of the liver have rarely been described in medical literature. Knowledge of clinical, pathological and immunohistochemical properties remains limited. We described an 82-year-old female patient with primary small cell carcinoma of the liver. Histologically, the tumor showed typical morphology of a pulmonary small cell carcinoma. Immunohistochemically, the tumor revealed neuroendocrine differentiation; positive reaction for chromogranin, synaptophysin, CD56, and neuron specific enolase. The tumor was also positive for TTF-1 and c-kit but completely negative for hepatocyte, carcinoembryonic antigen, cytokeratin 7; 19; and 20. Herein, we discussed the clinical, pathological and immunohistochemical findings of extrapulmonary small cell carcinoma of the liver and reviewed the relevant literature.     

Phosphatidylcholine attenuated docetaxel-induced peripheral neurotoxicity in rats

Docetaxel is a taxane chemotherapeutic agent used in the treatment of breast cancer, prostate cancer and gastric cancer, but several side effects such as peripheral neurotoxicity could occur. The present study was designed to investigate the therapeutic potential of phosphatidylcholine (PC) on docetaxel-induced peripheral neurotoxicity. Rats were randomly divided into three groups and treated for 4 weeks. Behavioral tests were conducted to measure the effects of PC on docetaxel-induced decreases in mechanical & thermal nociceptive threshold. Biochemical tests were conducted to measure the level of oxidative stress on sciatic nerve. Histopathological and immunohistochemical experiments were also conducted to assess neuronal damage and glial activation. PC treatment significantly attenuated docetaxel-induced changes in mechanical & thermal nociceptive response latencies. PC decreased oxidative stress in sciatic nerve by increasing antioxidant levels (glutathione, glutathione peroxidase and superoxide dismutase activity). In immunohistochemical evaluation, PC treatment ameliorated docetaxel-induced neuronal damage and microglial activation in the sciatic nerve and spinal cord. Thus, PC showed protective effects against docetaxel-induced peripheral neurotoxicity. These effects may be attributed to its antioxidant properties and modulation of microglia.     

The RANTES -403G>A promoter polymorphism in Korean men: association with serum RANTES concentration and coronary artery disease

In the present study we investigated the association of the RANTES (regulated upon activation, normal T-cell expressed and secreted) -28C>G and -403G>A promoter polymorphisms with the concentration of serum RANTES and CAD (coronary artery disease) in Korean men. We included 553 male CAD patients with (n=176) or without (n=377) Type 2 diabetes, aged 40-65 years with previous myocardial infarction ( approximately 50%) or angiographically confirmed CAD ( approximately 50%), and 416 aged-matched healthy male controls. The main outcome measures were the OR (odds ratio) of CAD risk and the serum RANTES concentration evaluated by sandwich ELISA. Although the RANTES -28C>G genotype had no significant association with CAD risk, the presence of the minor allele of the RANTES -403G>A single nucleotide polymorphism was associated with a lower risk of CAD {OR 0.70 [95% CI (confidence interval) 0.54-0.92], P=0.011} after adjusting for age, BMI (body mass index), cigarette smoking and alcohol consumption. Serum RANTES concentrations were significantly associated with the -403G>A genotype in controls (G/G: 44.7+/-3.3 ng/ml, G/A: 36.5+/-2.0 ng/ml, A/A: 28.7+/-2.5 ng/ml; P<0.001), non-diabetic CAD patients (G/G: 50.9+/-3.0 ng/ml, G/A: 42.2+/-2.6 ng/ml, A/A: 41.3+/-4.4 ng/ml; P<0.05) and diabetic CAD patients (G/G: 58.5+/-3.5 ng/ml, G/A: 49.6+/-4.1 ng/ml, A/A: 42.2+/-4.3 ng/ml; P<0.05); however, such associations were not observed in the subgroup of CAD patients taking lipid-lowering medication. Moreover, serum RANTES was positively correlated with C-reactive protein (r=0.289, P<0.001) and platelet counts (r=0.253, P<0.001). The results of the present study demonstrate that the RANTES -403A allele is associated with lower serum RANTES concentrations and consequently with reduced CAD risk.     

Mechanistic Model for Blood Pressure and Heart Rate Changes Produced by Telmisartan in Human Beings

Telmisartan, an angiotensin receptor blocker (ARB), is indicated for the treatment of essential hypertension. This study aimed to develop a mechanistic model of telmisartan drug effect in human beings using non‐invasive markers. Data were acquired from a previous study where telmisartan 80 mg was given once daily for 6 days. Systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were measured before dosing for days 1–5 and serially after the last dose. Mean arterial pressure (MAP) and pulse pressure (PP) were calculated from SBP and DBP. Relationships between MAP, PP, HR and total peripheral resistance (TPR) were developed. Circadian variation was incorporated into PP and HR, and TPR was assumed to adjust itself in response to changes in PP and HR based on baroreflex mechanism. Drug effects were then described as lowering the set point of MAP through TPR with a physiological feedback effect stimulating HR and PP. Drug concentrations were described by a two‐compartment disposition model with first‐order absorption and lag time, and first‐order elimination. Circadian variation was described by cosine functions, having periods of 12 and 24 hr. A log‐linear model was used to describe drug effect, with estimated drug effect parameter of 0.051/hr. Estimated fractional turnover rate of PP, HR and TPR was 11.2 hr. The model successfully described the time courses of these cardiovascular variables. This work demonstrated the feasibility of using non‐invasive cardiovascular measurements to derive a mechanistic model for telmisartan in human beings. The model may be suitable for other ARBs.