Search Results

You are looking at 1 - 3 of 3 items for :

  • Author or Editor: G. Lengyel x
  • Biology and Life Sciences x
  • Refine by Access: All Content x
Clear All Modify Search

The effect of plasma glucose concentration on the cerebral uptake of [18 F]-fluorodeoxy-D-glucose (FDG) was studied in a broad concentration range in a rabbit brain model using dynamic FDG PET measure- ments. Hypoglycemic and hyperglycemic conditions were maintained by manipulating plasma glucose applying i.v. glucose or insulin load. FDG utilization (K) and cerebral glucose metabolic rate (CGMR) were evaluated in a plasma glucose concentration range between 0.5 mM and 26 mM from the kinetic constant k1, k2, k3 obtained by the Sokoloff model of FDG accumulation. A decreasing set of standard FDG uptake values found with increasing blood glucose concentration was explained by competition between the plasma glucose and the radiopharmacon FDG. A similar trend was observed for the forward kinetic constants k1, and k3 in the entire concentration range studied. The same decreasing tendency of k2 was of a smaller magnitude and was reverted at the lowest glucose concentrations where a pronounced decrease of this backward transport rate constant was detected. Our kinetic data indicate a modulation of the kinetics of carbohydrate metabolism by the blood glucose concentration and report on a special mechanism compensating for the low glucose supply under conditions of extremely low blood glucose level.

Restricted access
Acta Alimentaria
Authors: T. Ábel, A. Blázovics, A. Wimmer, G. Bekő, B. Gaál, B. Blazics, M. Eldin, J. Fehér, I. Szabolcs, and G. Lengyel

The effect of moderate alcohol consumption on insulin sensitivity is actually a topic of intense research nowadays. In this study we investigated the effect of moderate consumption of white wine in subjects with metabolic syndrome. Thirty-two patients with metabolic syndrome participated in this prospective, randomised, double-blind study. The subjects received either Müller-Thurgau (n=14) or Pintes (n=18) sort of wine for 4 weeks. Male and female subjects consumed 300 ml wine (30 g alcohol) and 200 ml wine (20 g alcohol) per day, respectively. Clinical and laboratory parameters were determined before and after the period of wine consumption. The HOMA-IR showed a significant decrease upon the consumption of both sorts of wine as compared to the baseline (Müller-Thurgau group: 1.85±2.1 vs. 1.06±0.6; P=0.03; Pintes group: 2.28±2.04 vs. 1.08±0.6; P=0.002). Four weeks of wine consumption lead to significant decreased of ALT (alanine aminotransferase; Müller-Thurgau group: P=0.003; Pintes group: P=0.002) and AST (aspartate aminotransferase; Müller-Thurgau group: P=0.003; Pintes group: P=0.02). Epidermal growth factor (EGF) levels increased significantly in both groups (Müller-Thurgau group: P=0.004; Pintes group: P=0.001). The plasma reducing capacity increased significantly upon the consumption of both sorts of wine (Müller-Thurgau group: P=0.002; Pintes group: P=0.001). In patients consuming Müller-Thurgau there was a significant decrease of total cholesterol (5.4±1.4 vs. 4.9±1.2 mmol l−1; P=0.006) and LDL-cholesterol (3.9±1.1 vs. 3.6±1.2 mmol l−1; P=0.04) levels. In the Pintes group we found no significant difference either in total cholesterol (5.1±0.6 vs. 5.0±0.7 mmol l−1; P=0.25) or LDL-cholesterol (3.6±0.6 vs. 3.6±0.6 mmol l−1; P=0.5) concentrations. The results of our study confirm that moderate consumption of white wine increases insulin sensitivity and EGF levels in persons with metabolic syndrome.

Restricted access
Agrokémia és Talajtan
Authors: Péter Csathó, E. Osztoics, J. Csillag, T. Lengyel, L. Gonda, L. Radimszky, G. Baczó, M. Magyar, K. R. Végh, M. Karátsonyi, T. Takács, A. Lukács, and T. Németh

Depending on their origin, sedimentary phosphate rocks (PRs) may differ in their P solubility, and, as a consequence, in their agronomic effectiveness. The effect of six phosphate rocks (PR) - originating from Algeria (ALG), North Florida (FLO), North Carolina (NCA), Senegal (SEN) Morocco (MOR) and Hyperphosphate (HYP) with various P solubility (evaluated by 2% formic acid, 2% citric acid, and neutral ammonium citrate) - as well as single superphosphate (SSP) and superphosphate + lime (SSP + Ca) (each P source on 4 P levels, with doses of 0, 100, 400 and 1600 mg P 2 O 5 ·kg -1 soil) on the shoot yield of tillering stage spring barley, soil available P (i.e. H 2 O, Olsen, Bray1, Lakanen-Erviö (LE) and ammonium lactate (AL) extractable P contents) were studied in pot experiments set up with acidic sandy soil (Nyírlugos, Hungary) and acidic clay loam soil (Ragály, Hungary), both with low P supplies.  The average spring barley shoot yield at the beginning of shooting was 95% higher on the colloid-rich acidic (pH KCl : 4.5) clay loam soil than on the colloid-poor acidic (pH KCl : 3.8) sandy soil. The differences in the solubility of phosphate rocks showed close correlation to the differences in P responses. On both soils, the correlation between total PR-P added and P responses in spring barley shoot yield was much weaker than that between neutral ammonium citrate soluble PR-P added and P responses in spring barley shoot yield. When phosphate rocks were applied as P sources, the comparison of soil test P methods showed a different picture on the two soils. In the case of the acidic sandy soil (Nyírlugos), the strongly acid LE-P (r² = 0.83) and AL-P (r² =0.74) tests gave the highest correlation coefficients with spring barley responses to P, while on the acidic clay loam soil (Ragály) these were achieved by the Olsen-P (r² = 0.88) and Bray1-P (r² =0.88) methods. 

Restricted access