Association between circulating irisin levels and epicardial fat in patients with treatment-naïve overt hyperthyroidism

Abstract

Background: Hyperthyroidism is associated with increased metabolic activity and thermogenesis. Irisin is a key molecule in thermogenesis and energy expenditure via adipose tissue browning. Epicardial fat was previously defined as brown-like fat. Thus, here we aimed to evaluate the association between serum irisin level and epicardial fat thickness (EFT) in patients with hyperthyroidism.

Methods: A total of 25 hyperthyroid patients and 24 age-, sex- and BMI-matched healthy controls were enrolled. Serum irisin levels, thyroid hormone levels, and body compositions were compared. EFT was measured via transthoracic echocardiography.

Results: Serum irisin level and EFT were significantly higher in the hyperthyroid group (p?<?0.001 and p?=?0.001, respectively). The distributions of fat-free mass, muscle mass and fat mass were similar between the study groups. Serum irisin level was negatively correlated with TSH (p?<?0.001) and positively correlated with fT3 (p?<?0.001), fT4 (p?<?0.001) and TSH receptor antibody (p?=?0.002) levels and EFT (p?=?0.001). In multivariate linear regression analysis, TSH (β?=??0.475, p?<?0.001) and EFT (β?=?0.290, p?=?0.023) levels were significantly associated with serum irisin levels.

Conclusions: An increased serum irisin level associated with EFT might contribute to metabolic derangement in hyperthyroidism. Further studies are needed to elucidate whether irisin levels and EFT are affected by hyperthyroidism or vice versa.     

The interaction between breathing and swallowing in healthy individuals

In this article, we aimed at investigating the interaction between breathing and swallowing patterns in normal subjects. Ten healthy volunteers were included in the study. Diaphragm EMG activity was recorded by a needle electrode inserted into the 7th or 8th intercostal space. Swallowing was monitored by submental EMG activity, and laryngeal vertical movement was recorded by using a movement sensor. A single voluntary swallow was initiated during either the inspiration or expiration phases of respiration, and changes in EMG activity were evaluated. When a swallow coincided with either inspiration or expiration, the duration of the respiratory phase was prolonged. Normal subjects were able to voluntarily swallow during inspiration. During the inspiration phase with swallowing, diaphragmatic activity did not ceased and during the expiration phase with swallowing, there was a muscle activity in the diaphragm muscle.     

Fusarium Species Isolated from Common Weeds in Eggplant Fields and Symptomless Hosts of Fusarium oxysporum f. sp. melongenae in Turkey

Thirteen species of weed plants were collected between May and September in 2010 and 2011 from eggplant fields representing 11 distinct locations covering a wide geographical area of Turkey. Weeds are potential hosts of many plant pathogens and may not exhibit disease symptoms when colonized. Fusarium spp. were isolated from five monocotyledonous species and eight dicotyledonous species. A total of 212 isolates recovered from weeds were assigned to eight Fusarium species on the basis of morphological characteristics. F. oxysporum was the most frequently isolated species (29.7%), followed by F. solani (19.8%), F. graminearum (13.7%), F. verticillioides (12.7%), F.equiseti (9.9%), F. avenacearum (8.0%), F. proliferatum (3.8%) and F. subglutinans (2.4%). The F. oxysporum isolates from different weed hosts were characterized by means of pathogenicity and vegetative compatibility grouping (VCG) tests. Among these, 29 isolates were found to be pathogenic to eggplant cv. Kemer and re‐isolated as Fusarium oxysporum Schlecht. f. sp. melongenae (Fomg) as evidenced. These isolates from weed hosts were assigned to VCG 0320. This study is the first report of Fomg isolated from weeds in eggplant fields in Turkey. None of the weed species tested showed symptoms of wilting in pot experiments, and F. oxysporum was isolated with greater frequency from all inoculated weeds. The results of this study indicate that several weed plants may serve as alternative sources of inoculum for Fomg, during the growing season.     

The 8-oxoguanine DNA N-glycosylase 1 (hOGG1) Ser326Cys variant affects the susceptibility to Graves' disease

Oxidative DNA damage, caused by either endogenous or exogenous sources of reactive oxygen species (ROS), has been linked several diseases including Graves' disease (GD). 7,8‐Dihydro‐8‐oxoguanine (8‐oxoG) is a major lesion produced by ROS and is considered a key biomarker of oxidative DNA damage. In humans, 8‐oxoG is mainly repaired by 8‐oxoguanine DNA N‐glycosylase‐1 (hOGG1), which is an essential component of the base excision repair (BER) pathway. The functional studies showed that hOGG1 Ser326Cys polymorphism is associated with the reduced DNA repair activity and increased risk for some oxidative stress‐related diseases. In this study, we firstly investigated hOGG1 Ser326Cys polymorphism in GD. According to our results, Cys/Cys genotype frequency in the GD patients (23.4%) was significantly higher than the controls (9.2%). Cys/Cys genotype had an 3.5‐fold [95% CI (confidence interval): 2.10–6.01, p < 0.001] the Cys allele had 1.83‐fold (95% CI: 1.43–2.34, p < 0.001) increase in the risk for developing GD. Our results suggest that Ser326Cys polymorphism of the hOGG1 gene is associated with GD risk. Copyright © 2011 John Wiley & Sons, Ltd.     

Psephellus yusufeliensis sp. nov. from north-east Anatolia, Turkey

Psephellus yusufeliensis O. Tugay & Uysal sp. nov. (Asteraceae) from Yusufeli (B7 Artvin-Turkey) is described and illustrated. It is closely related to P. aucheriana (DC) Wagenitz & F. H. Hellw. Diagnostic morphological characters are provided and the relationship to other Psephellus species in Turkey is discussed. The geographical distribution of the new species and other related species are mapped. Notes are also presented on the ecology, biogeography and conservation status of the new species.     

Investigation of the effects of α-tocopherol on the levels of Fe,Cu, Zn,Mn, and carbonic anhydrase in rats with bleomycin-induced pulmonary fibrosis

This study was designed to examine the effects of vitamin E on the levels of Zn, Mn, Cu, Fe, and carbonic anhydrase in rats with bleomycin-induced pulmonary fibrosis. Twenty-one male Wistar albino rats were randomly divided into three groups: bleomycin alone, bleomycin+vitamin E, and saline alone (control group). The bleomycin group was given 7.5 mg/kg body weight (single dose) bleomycin hydrochloride intratracheally. The bleomycin+vitamin E group was also instilled with bleomycin hydrochloride but received injections of α-tocopherol twice a week. The control group was treated with saline alone. Animals were sacrified 14 d after intratracheal instillation of bleomycin. Tissue Zn, Mn, Cu, Fe, and carbonic anhydrase activities were measured in the lung and liver. Lung Cu, Fe, and carbonic anhydrase activity increase in both experimental groups. Zn and Mn levels decreased, except for the Mn level in the bleomycin group. Liver Zn, Mn, and Cu levels decreased in both experimental groups compared to the control group, whereas Fe and carbonic anhydrase activity increased in comparison to the control group. However, the liver tissue Fe level decreased compared to the control group. In the histopathologic assesment of lung sections in the bleomycin+vitamin E group, partial fibrotic lesions were observed, but the histopathologic changes were much less severe compared to the bleomycin-treated group.     

Hypoglycemia due to ectopic release of insulin from a paraganglioma

Insulin-secreting pancreatic tumors and insulin-like growth hormone-secreting non-islet cell tumors can cause hypoglycemia. However, insulin-releasing paraganglioma or pheochromocytoma has almost never been reported. A 67-year-old female patient was admitted to our hospital because of headache, palpitation, perspiration, faintness, frequent sense of hunger and absent-mindedness. These intermittent symptoms had begun approximately a year before admission. On physical examination, she had high blood pressure of 150/90 mm Hg. Hormonal studies demonstrated increased urinary norepinephrine levels, and hyperinsulinemic hypoglycemia was confirmed while the patient was symptomatic. Abdominal MRI revealed a retroperitoneal mass measuring 4.5 cm in the pancreatic region. She was treated with an alpha-blocking agent to control blood pressure preceding the removal of the mass. Histopathological diagnosis was paraganglioma, and immunohistochemically insulin staining in the neoplastic cells was demonstrated. Her blood pressure normalized and hypoglycemia relieved after the operation. The patient did not have recurrence of hypoglycemia after a year of follow-up. Paraganglioma is a rare tumor of the neural crest, and co-secretion of insulin and catecholamines has been reported only by a single case report in the literature. The present patient is another case with this co-secretion.     

A quantitative colorimetric method of measuring alkaline phosphatase activity in eukaryotic cell membranes

Alkaline phosphatase (ALP) is glycoprotein structured metalophosphatase with several defined functions. It is present in many tissues of all living beings from bacteria to mammals. The enzyme may catalyse the hydrolysis of various monophosphate esters at alkaline pH. The objective of this study was to quantify ALP functioning particularly in the membranes of eukaryotic cells. The membranes of seven different cells (myeloma cells; hybrid cells; erythroleukaemia cells; lymphocytes and erythrocytes) were tested for ALP activity using a cellular enzyme assay, which is based on the conversion of para-nitrophenylphosphate (p-NPP) to para-nitrophenol and the colorimetric determination of the resulting coloured product. The test system was optimised with respect to substrate concentration, reaction time and the number of cells used as a source of enzyme. The obtained values were converted to quantitative results through a standard curve created using commercial ALP. In order to determine the effect of serum concentration on enzyme activity, 1G2 hybridoma, which is among the cells used in this study and which synthesizes monoclonal antibody against human serum albumin, was produced in different serum concentrations ranging from 0 to 15%.     

Mitochondrial dynamic alterations regulate melanoma cell progression

Research on mitochondrial fusion and fission (mitochondrial dynamics) has gained much attention in recent years, as it is important for understanding many biological processes, including the maintenance of mitochondrial functions, apoptosis, and cancer. The rate of mitochondrial biosynthesis and degradation can affect various aspects of tumor progression. However, the role of mitochondrial dynamics in melanoma progression remains controversial and requires a mechanistic understanding to target the altered metabolism of cancer cells. Therefore, in our study, we disrupted mitochondrial fission with mdivi-1, the reported inhibitor of dynamin related protein 1 (Drp1), and knocked down Drp1 and Mfn2 to evaluate the effects of mitochondrial dynamic alterations on melanoma cell progression. Our confocal study results showed that mitochondrial fission was inhibited both in mdivi-1 and in Drp1 knockdown cells and, in parallel, mitochondrial fusion was induced. We also found that mitochondrial fission inhibition by mdivi-1 induced cell death in melanoma cells. However, silencing Drp1 and Mfn2 did not affect cell viability, but enhanced melanoma cell migration. We further show that dysregulated mitochondrial fusion by Mfn2 knockdowns suppressed the oxygen consumption rate of melanoma cells. Together, our findings suggest that mitochondrial dynamic alterations regulate melanoma cell migration and progression.     

Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?

Biological Trace Element Research - Magnesium is an element of great importance functioning because of its association with many cellular physiological functions. The magnesium content of foods is...