A low high density lipoprotein (HDL) level is associated with carotid artery intima-media thickness in asymptomatic members of low HDL families

Low serum high-density lipoprotein cholesterol (HDL-C) is a strong predictor of coronary heart disease (CHD). The aim of the present study was to evaluate the metabolic parameters predicting the atherosclerotic changes in asymptomatic members of low HDL-C families. We performed carotid B-mode ultrasonography with intima-media thickness (IMT) measurement for 89 asymptomatic members of Finnish low HDL-C families. The family members were categorized as affected or unaffected according to the 10th age-gender specific HDL-C percentile. In the affected group, the most marked decrease of HDL subclasses was observed for HDL2-C when compared with the unaffected (109% difference). In the partial correlation analyses, age and gender showed significant correlations with the mean IMT (for age, r=0.880, P<0.001, and for gender, r=-0.361, P=0.018). Importantly, HDL-C and HDL2-C were significantly inversely related to the mean carotid IMT, also after correction for age (for HDL-C, r=-0.186, P=0.043, for HDL2-C, r=-0.208, P=0.029, when adjusted for age). The correlation for HDL-C was significant also when adjusted for gender. In conclusion, low HDL-C is associated with increased carotid artery IMT in asymptomatic members of low HDL-C families.     

Effects of morning cortisol replacement on glucose and lipid metabolism in GH-treated subjects

OBJECTIVE: Insulin resistance is a frequent consequence of GH replacement therapy but patients on GH replacement therapy often also have replacement of other hormone deficiencies which theoretically could modify the metabolic effects of GH. In particular, cortisol replacement if given in supra physiologic doses immediately before the evaluation of insulin sensitivity could influence insulin sensitivity. The aim of this study was thus to evaluate the effect of morning cortisol replacement given prior to a euglycaemic clamp combined with infusion of [3-(3)H]glucose and indirect calorimetry on glucose and lipid metabolism. METHODS: Ten GH/ACTH-deficient adults received, in a double-blind manner, either cortisol (A) or placebo (B) before the clamp whereas five GH-deficient-ACTH-sufficient adults participated in a control (C) clamp experiment. All subjects received GH replacement therapy. RESULTS: Serum cortisol levels were significantly higher after cortisol than after placebo (324+/-156 vs 132+/-136 mmol/l; P=0.006) and similar to controls (177+/-104 mmol/l). As a measure of the biological effect of cortisol, eosinophil leukocyte counts in peripheral blood decreased (164+/-91 x 10(9)/l vs 216+/-94 x 10(9)/l; P=0.04). Cortisol replacement had no significant effect on insulin-stimulated glucose uptake (11.8+/-1.8 vs 13.2+/-3.9 micromol/kg min), either on glucose oxidation or on glucose storage. There was also no significant effect of cortisol on fasting endogenous glucose production and no effect was seen on serum free fatty acid concentrations. CONCLUSION: Administration of cortisol in the morning before a clamp cannot explain the insulin resistance seen with GH replacement therapy.     

High percentage of oral lichen planus and lichenoid lesion in oral squamous cell carcinomas

Objective: Oral lichen planus (OLP) and lichenoid lesions (OLL) are regarded as precursor lesions of oral squamous cell carcinoma (OSCC) with potential for malignant transformation. This potential is not clear due to difficulties in diagnosis of OLP and OLL. Our aim was therefore to evaluate previously identified OLP and OLL as precursor lesions in OSCC and to identify cancer related etiological factors such as smoking and alcohol consumption.

Material and methods: We retrospectively reviewed all cases (total 323, comprising 164 females and 159 males) with OSCC treated at the Department of Oral and Maxillofacial Diseases and Surgery, Helsinki University Hospital during 2015. Confirmed by histopathological biopsy, 58 (17.9%) had OLP and 13 had OLL (4.0%) as precursor lesion.

Results: Patients with OLP were slightly older than those without it. OLP was more common in females than in males (p?p?=?.006) and cancer relapses less common (p?=?.005). Smoking was less frequent in patients with OLP and OLL (p?p?Conclusion: Our findings confirm the importance of active follow-up of all patients with OLP and OLL even in patients who do not fit a traditional high-risk category for OSCC.     

Characterization and electrochemical properties of iron-doped tetrahedral amorphous carbon (ta-C) thin films

Iron-doped tetrahedral amorphous carbon thin films (Fe/ta-C) were deposited with varying iron content using a pulsed filtered cathodic vacuum arc system (p-FCVA). The aim of this study was to understand effects of iron on both the physical and electrochemical properties of the otherwise inert sp³-rich ta-C matrix. As indicated by X-ray photoelectron spectroscopy (XPS), even ∼0.4 at% surface iron had a profound electrochemical impact on both the potential window of ta-C in H₂SO₄ and KOH, as well as pseudocapacitance. It also substantially enhanced the electron transport and re-enabled facile outer sphere redox reaction kinetics in comparison to un-doped ta-C, as measured with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) using outer-sphere probes Ru(NH₃)₆, IrCl₆, and FcMeOH. These increases in surface iron loading were linked to increased surface oxygen content and iron oxides. Unlike few other metals, an iron content even up to 10 at% was not found to result in the formation of sp²-rich amorphous carbon films as investigated by Raman spectroscopy. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) investigations found all films to be amorphous and ultrasmooth with R_q values always in the range of 0.1–0.2 nm. As even very small amounts of Fe were shown to dominate the electrochemistry of ta-C, implications of this study are very useful e.g. in carbon nanostructure synthesis, where irregular traces of iron can be readily incorporated into the final structures.

Surface iron levels as low as 0.4 at% (XPS) can considerably change the electrochemical properties of initially inert carbon surfaces.     

Pt-grown carbon nanofibers for enzymatic glutamate biosensors and assessment of their biocompatibility

Application-specific carbon nanofibers grown from Pt-catalyst layers have been shown to be a promising material for biosensor development. Here we demonstrate immobilization of glutamate oxidase on them and their use for amperometric detection of glutamate at two different potentials. At −0.15 V vs. Ag/AgCl at concentrations higher than 100 μM the oxygen reduction reaction severely interferes with the enzymatic production of H₂O₂ and consequently affects the detection of glutamate. On the other hand, at 0.6 V vs. Ag/AgCl enzyme saturation starts to affect the measurement above a glutamate concentration of 100 μM. Moreover, we suggest here that glutamate itself might foul Pt surfaces to some degree, which should be taken into account when designing Pt-based sensors operating at high anodic potentials. Finally, the Pt-grown and Ni-grown carbon nanofibers were shown to be biocompatible. However, the cells on Pt-grown carbon nanofibers had different morphology and formation of filopodia compared to those on Ni-grown carbon nanofibers. The effect was expected to be caused rather by the different fiber dimensions between the samples than the catalyst metal itself. Further experiments are required to find the optimal dimensions of CNFs for biological purposes.

Pt-grown carbon nanofibers were utilized for the fabrication of glutamate biosensors and in addition their biocompatibility was assessed.     

Fat feeding impairs glycogen synthase activity in mice without effects on its gene expression

To examine whether the effects of high-fat feeding on glycogen synthase (GS) activity and mRNA levels differ between diabetes-prone (C57BL/6J) and diabetes-resistant mice (NMRI), we measured GS activity and mRNA levels in muscle from C57BL/6J and NMRI mice fed a high-fat or normal chow diet for 3, 6, and 15 months. As compared with chow feeding, fat feeding increased plasma insulin levels in C57BL/6J mice at 15 months (464 +/- 29 v 267 +/- 47 pmol/L, P =.005), which was associated with elevated plasma glucose levels at 15 months (5.3 +/- 0.3 v 3.8 +/- 0.2 mmol/L, P =.001). Fat feeding increased plasma insulin levels also in NMRI mice at 15 months (705 +/- 145 v 275 +/- 64 pmol/L, P =.01) without, however, a rise of plasma glucose levels. In parallel with increased insulin levels, decreased muscle GS fractional velocity (FV) was observed at 6 (49.0% +/- 2.6% v 69.1% +/- 7.3%, P =.04) and 15 (45.8% +/- 1.8% v 53.4% +/- 1.6 %, P <.01) months but not at 3 months in the fat-fed C57BL/6J mice. Similarly, there was a significant decrease in GS fractional activity at 3 (57.9% +/- 4.3% v 70.4% +/- 2.6 %, P <.03) and 15 (47.3% +/- 2.4% v 56.4% +/- 2.1%, P =.02) but not at 6 months in the fat-fed NMRI mice. The decrease in GS activity was not associated with changes in mRNA levels at any time points. We conclude that (1) fat feeding results in similar elevation of plasma insulin levels and impairs GS activity in C57BL/6J and NMRI mice, and (2) the changes in GS activity do not involve effects on gene expression.