Exercise training-induced PPARβ increases PGC-1α protein stability and improves insulin-induced glucose uptake in rodent muscles

This study aimed to investigate the long-term effects of training intervention and resting on protein expression and stability of peroxisome proliferator-activated receptor β/δ (PPARβ), peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1α), glucose transporter type 4 (GLUT4), and mitochondrial proteins, and determine whether glucose homeostasis can be regulated through stable expression of these proteins after training. Rats swam daily for 3, 6, 9, 14, or 28 days, and then allowed to rest for 5 days post-training. Protein and mRNA levels were measured in the skeletal muscles of these rats. PPARβ was overexpressed and knocked down in myotubes in the skeletal muscle to investigate the effects of swimming training on various signaling cascades of PGC-1α transcription, insulin signaling, and glucose uptake. Exercise training (Ext) upregulated PPARβ, PGC-1α, GLUT4, and mitochondrial enzymes, including NADH-ubiquinone oxidoreductase (NUO), cytochrome c oxidase subunit I (COX1), citrate synthase (CS), and cytochrome c (Cyto C) in a time-dependent manner and promoted the protein stability of PPARβ, PGC-1α, GLUT4, NUO, CS, and Cyto C, such that they were significantly upregulated 5 days after training cessation. PPARβ overexpression increased the PGC-1α protein levels post-translation and improved insulin-induced signaling responsiveness and glucose uptake. The present results indicate that Ext promotes the protein stability of key mitochondria enzymes GLUT4, PGC-1α, and PPARβ even after Ext cessation

Hole density dependence of effective mass, mobility and transport time in strained Ge channel modulation-doped heterostructures

We performed systematic low-temperature (T = 350 mK–15 K) magnetotransport measurements on the two-dimensional hole gas with various sheet carrier densities Ps = (0.57–2.1)×1012 cm–2 formed in the strained Ge channel modulation-doped (MOD) SiGe heterostructures grown on Si substrates. It was found that the effective hole mass deduced by temperature dependent Shubnikov–de Hass oscillations increased monotonically from (0.087±0.05)m0 to (0.19±0.01)m0 with the increase of Ps, showing large band nonparabolicity in strained Ge. In contrast to this result, the increase of the mobility with increasing Ps (up to 29 000 cm2/V s) was observed, suggesting that Coulomb scattering played a dominant role in the transport of the Ge channel at low temperatures. In addition, the Dingle ratio of the transport time to the quantum lifetime was found to increase with increasing Ps, which was attributed to the increase of remote impurity scattering with the increase of the doping concentration in MOD SiGe layers

Extremely high room-temperature two-dimensional hole gas mobility in Ge/Si0.33Ge0.67/Si(001) p-type modulation-doped heterostructures

To extract the room-temperature drift mobility and sheet carrier density of two-dimensional hole gas (2DHG) that form in Ge strained channels of various thicknesses in Ge/Si0.33Ge0.67/Si(001) p-type modulation-doped heterostructures, the magnetic field dependences of the magnetoresistance and Hall resistance at temperature of 295 K were measured and the technique of maximum entropy mobility spectrum analysis was applied. This technique allows a unique determination of mobility and sheet carrier density of each group of carriers present in parallel conducting multilayers semiconductor heterostructures. Extremely high room-temperature drift mobility (at sheet carrier density) of 2DHG 2940 cm2 V–1 s–1 (5.11×1011 cm–2) was obtained in a sample with a 20 nm thick Ge strained channel

Relationship Between Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases Following High-fat Diet and Acute Exercise

Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the tissue and inflammation. Several tissue inhibitors of MMPs (TIMPs) are known to inhibit the activity of MMPs. PURPOSE: The current study investigated the responses of MMP-1, -2, -9, and -10 and TIMP-1, -2, -3, and -4 after a 3-week high-fat, low-carbohydrate (HFLC) diet following an acute aerobic exercise. METHODS: Physically active (unprofessional, competitive marathon runners) male subjects (N=8, age= 39.5 ± 9.9 years) volunteered for the study. Subjects maintained their habitual high carbohydrate (HC) diets before switching to the HFLC diet (70% total caloric intake from fat, not exceeding 50 g of carbohydrates) for 3 weeks. Subjects performed an acute bout of aerobic exercise before and 24 hours after each HC and HFLC diet trial. The exercise protocol consisted of treadmill running at varying paces (personal race paces) for 50 minutes (split into 5, 10-minute periods with 2 minutes of rest in between). Following a 20-minute recovery, subjects additionally performed a 5-km time trial on an outdoor course. Overnight fasting blood samples were collected at pre- and 24-hours post-exercise for each diet trial to analyze changes in MMPs and TIMPs. The data were analyzed using an ANOVA [(HC and HFLC) X (pre- and post-exercise)]. If a significant interaction was found, a Tukey’s post-hoc test was performed (p \u3c 0.05). RESULTS: There was no significant difference in MMPs or TIMPs between the HC and HFLC diet trials, and an acute bout of aerobic exercise did not alter MMPs or TIMPs. There were, however, significant positive correlations between MMP-2 and TIMP-2 (r (14) = 0.51, p = 0.01) and MMP-9 and TIMP-2 (r (14) = 0.49, p = 0.01). Additionally, a significant negative correlation was found between TIMP-4 and MMP-4 (r (14) = -0.57, p = 0.02). CONCLUSION: A relatively short-term high-fat diet and an acute aerobic exercise did not influence serum MMPs or TIMPs in healthy, trained male runners. The activity of MMP-4 may be related to TIMP-4, while the activity of both MMP-2 and -9 may be dependent on TIMP-2. It is highly recommended that future studies focus on examining the effects of a long-term HFLC diet on metabolic pathways of circulating or tissue MMPs and TIMPs in a variety of populations

Plasma Glucose and Lipid Profiles Following High-Fat Diet and Acute Aerobic Exercise

PURPOSE: To examine the effects of a 3-week high-fat (HF) diet on plasma glucose, lipids, and lipoproteins following an acute bout of aerobic exercise in middle-aged men. METHODS: Physically active (non-elite, competitive marathon runners), male participants (N=8, age=39.5±9.9 years) volunteered for the study. Participants maintained their habitual high-carbohydrate (HC) diet (60-70% caloric intake from carbohydrate) prior to switching to the HF diet (70% caloric intake from fat, not exceeding 50g of carbohydrates) for 3 weeks. At the end of each diet trial, participants performed an acute bout of aerobic exercise, which consisted of running at varying paces (personal race paces) on a treadmill for 50 minutes (split into 5, 10-minute periods with 2 minutes of rest in between). Following a 20-minute recovery from the treadmill exercise, participants additionally ran a 5-km time trial (average run time = 23.69±2.41 minutes) on an outdoor road course. Overnight fasting blood samples were collected before and 24 hours after exercise for the HC and HF diet trial to analyze glucose, triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), lipoprotein(a), very low-density lipoprotein cholesterol (VLDL-C), low-density lipoprotein-cholesterol (LDL-C). The data were analyzed using a two-way ANOVA [2 (diet: HC and HF) X 2 (time: pre and post-exercise)]. Any significant interactions were further analyzed using a Tukey’s post-hoc test. A p-value was set at \u3c 0.05. RESULTS: A glucose level was higher (p=0.046) in the HC diet (96.81±2.45 mg/dL) than the HF diet (89.6±2.45 mg/dL). As compared with the HC diet, the HF diet showed a higher level of TC (142.58±4.75 vs. 171.71±4.75 mg/dL, p=0.001), HDL-C (49.26±3.01 vs. 58.58±3.01 mg/dL, p=0.037), and LDL-C (91.51±4.91 vs. 111.20±4.91 mg/dL, p=0.008), respectively. TG significantly decreased (p=0.03) from 65.68±5.93 to 38.46±5.93 mg/dL at 24 hours of post-exercise. CONCLUSION: The 3-weeks of HF diet modestly increased plasma lipids and lipoproteins within the desirable range. Implementing a relatively short-term HF diet does not appear to significantly elicit negative cardiovascular disease risk markers in non-elite, healthy middle-aged male runners. However, it is strongly recommended for future studies to investigate the safety and beneficial effects of a long-term HF diet on cardiovascular disease risk factors in a variety of population including the untrained

Clinical Characteristics and Treatment Outcomes of Mycobacterium kansasii Lung Disease in Korea

*These authors contributed equally to this work. ∙The authors have no financial conflicts of interest. Purpose: While Mycobacterium kansasii is a common cause of nontuberculous mycobacterial (NTM) lung disease in many developed countries, M. kansasii is infrequently isolated in Korea. We investigated the clinical and radiological features and treatment outcomes of M. kansasii lung disease in Korea retrospectively. Materials and Methods: We identified 41 patients with M. kansasii lung disease who met the diagnostic criteria for NTM lung disease in two tertiary referral hospitals in Seoul, Korea, between January 1998 and December 2007. Results: Their median age was 63 years [interquartile range (IQR) 51-75 years] and 33 (81%) were men. Twenty-three patients (56%) were smokers and 13 patients (32%) had previous pulmonary tuberculosis. The most common radiographic findings were nodules (n = 22, 54%) and consolidation (n = 22, 54%). Cavitation was present in 13 patients (32%). Thirty-one patients (76%) were treated with isoniazid, rifampin, and ethambutol. The median treatment duration was 16 months (IQR 9-18 months). The negative conversion rate after 12 months of treatment was 95%. Conclusion: Clinicians should be aware of the various radiographic manifestations of M. kansasii lung disease. With appropriate treatment, these patients have a good prognosis

Aspects of Quantum Gravity in Cosmology

We review some aspects of quantum gravity in the context of cosmology. In particular, we focus on models with a phenomenology accessible to current and near-future observations, as the early Universe might be our only chance to peep through the quantum gravity realm.Comment: 15 pages, 1 figure. Invited review for Modern Physics Letter A. Version 2: minor typos corrected, few references adde

Diagnosis and Treatment of Nontuberculous Mycobacterial Pulmonary Diseases: A Korean Perspective

The incidence of pulmonary disease caused by nontuberculous mycobacteria (NTM) appears to be increasing worldwide. In Korea, M. avium complex and M. abscessus account for most of the pathogens encountered, whilst M. kansasii is a relatively uncommon cause of NTM pulmonary diseases. NTM pulmonary disease is highly complex in terms of its clinical presentation and management. Because its clinical features are indistinguishable from those of pulmonary tuberculosis and NTMs are ubiquitous in the environment, the isolation and identification of causative organisms are mandatory for diagnosis, and some specific diagnostic criteria have been proposed. The treatment of NTM pulmonary disease depends on the infecting species, but decisions concerning the institution of treatment are never easy. Treatment requires the use of multiple drugs for 18 to 24 months. Thus, treatment is expensive, often has significant side effects, and is frequently not curative. Therefore, clinicians should be confident that there is sufficient pathology to warrant prolonged, multidrug treatment regimens. In all of the situations, outcomes can be best optimized only when clinicians, radiologists, and laboratories work cooperatively