Tomasz Sawczyn

DNA damage in grasshopper Chorthippus brunneus (Orthoptera) hatchlings following paraquat exposure

Comet assay was applied to study genotoxic damage induced by paraquat (PQ) in brain cells of Chorthippus brunneus (Insecta: Orthoptera) hatchlings. Percentage of the comet fluorescence in the tail (TDNA), length of the comet tail (TL) and Olive tail moment (OTM) were used for quantitative assessment of the DNA damage. Multiple regression analysis supplemented standard statistical elaboration of the results. Increasing PQ concentrations applied either directly to the brain cells suspension (10, 50, and 250 μM PQ final concentration--in vitro protocol) or indirectly (50, 250, and 1250 μM PQ final concentration--in vivo protocol) provoked significant increase of oxidative damage to DNA (higher median TDNA and OTM values). The damage increased with time of exposure (0, 5, 15, and 30 min) following in vitro application, but decreased in longer interval (3 vs 24 h) after in vivo administration of paraquat. On contrary, median TL values did not correlate with paraquat concentration irrespectively of the exposure protocol. Possible reason of this discrepancy in light of paraquat toxicity is discussed.

Long segment ileal transposition leads to early amelioration of glucose control in the diabetic obese Zucker rat

Introduction Fast delivery of food to the terminal ileum is thought to be pathophysiologically responsible for type 2 diabetes remission after obesity surgery. Imitating this effect, ileal transposition (IT) is designed as initiating diabetes remission for non-obese patients. Aim To date, it is not clear which length of the transposed segment achieves the best glucose lowering results. As previous rodent data mostly rely on a 10 cm IT, the current study evaluated a long segment IT (20 cm) in the diabetic obese Zucker rat. Material and methods Twenty male diabetic obese Zucker rats (Crl:ZUC-Leprfa) were randomly assigned to undergo either a long segment (20 cm; ∼ 50% of ileum) IT or sham surgery. Glucose control was determined by an oral glucose tolerance test (OGTT) on day −7, 0, 14 and 20. Analysis of the incretin hormones glucagon-like peptide 1 (GLP-1), peptide YY (PYY) and insulin was included in the first and third OGTT. Results Ileal transposition animals showed an early improvement of glucose control after 14 days (area under the curve: IT vs. baseline 314.7 ±229.0 mmol/l × min vs. 564.6 ±268.5 mmol/l × min; p < 0.05). Compared to sham animals, glucose-stimulated GLP-1 and PYY levels were raised (5.75 ±3.73 pmol/l vs. 18.52 ±14.22 pmol/l, p < 0.05; 129.7 ±64.62 pmol/l vs. 164.0 ±62.26 pmol/l, p < 0.05). Body weight gain from postoperative day 5 was greater for sham animals (50.22 ±20.93 γ vs. 16.4 ±25.93 g; p < 0.01). Conclusions Long segment IT shows a rapid rise in GLP-1 and PYY levels, thus leading to early amelioration of glucose control.

Serum FGF21 and RBP4 levels in patients with chronic hepatitis C

Abstract Introduction. Fibroblast growth factor-21 (FGF21) regulates glucose, lipid, and energy homeostasis. Retinol-binding protein-4 (RBP4) controls metabolic and proliferative cell functions. Aims and methods. Aims of the study were to assess (1) serum FGF21 and RBP4 levels in 75 non-obese chronic hepatitis C (CHC) patients and 41 healthy controls similar in age and BMI; (2) the relationship between their serum concentration and insulin resistance, liver histology, and biochemical parameters; (3) their effectiveness as diagnostic markers. Results. FGF21 levels increased significantly in CHC patients compared with controls (p = 0.04). CHC patients with steatosis had significantly higher FGF21 levels compared with those without steatosis (p = 0.01). FGF21 concentration was positively related to steatosis grade (r = 0.39, p = 0.007). RBP4 levels did not differ between CHC patients and controls, but were negatively associated with necro-inflammatory activity grade (r = (-0.34), p = 0.04), with significantly higher levels in patients with minimal inflammatory activity (G1 vs. G2/3, p < 0.001; G1 vs. G2, p = 0 < 001; G1 vs. G3, p = 0.01). After stepwise linear regression analysis adjusting for potential confounders, RBP4 levels retained their independent significance as a predictor of necro-inflammatory activity (β = -0.31; t = -2.15, p = 0.035) and FGF21 levels as a predictor of steatosis (β = 0.34; t = 2.31, p = 0.024). Serum FGF21 correlated with serum RBP4 levels (r = 0.32, p = 0.02). Conclusions. Serum FGF21 levels increased in CHC patients, especially in those with steatosis and were associated with steatosis grade. FGF21 seems to be a useful diagnostic marker in determining hepatic steatosis in CHC. A negative association between serum RBP4 and necro-inflammatory activity indicates that disease severity may determine RBP4 levels.

Alteration of carbohydrates metabolism and midgut glucose absorption in Gromphadorhina portentosa after subchronic exposure to imidacloprid and fenitrothion

This study was undertaken to test the hypothesis that following exposure to insecticides, changes take place in the metabolism of carbohydrates and absorption in the midgut of insects. The Madagascar hissing cockroach (Gromphadorhina portentosa) was chosen for the experiment as a model organism, due to it being easy to breed and its relatively large alimentary tract, which was important when preparing the microperfusion midgut bioassay. In each group of cockroaches treated with imidacloprid and fenitrothion, absorption of glucose, expressed as the area under the curve (AUC), was elevated compared to the control group. Glucose in the hemolymph of the examined insects was present in a vestigial amount, often below the threshold of determination, so the determinable carbohydrate indices were: hemolymph trehalose concentration and fat body glycogen content. The level of trehalose found in the hemolymph of insects when exposed to fenitrothion, and irrespective of the level of concentration mixed into food, were significantly lower when comparing to the control samples. Imidacloprid acted analogically with one exception at the concentration of 10 mg·kg−1 dry food where trehalose concentration did not differ from the control values. Coupling with fat body glycogen concentration was less visible and appeared only at the concentrations of 5 and 10 mg imidacloprid·kg−1 dry food. As described in this study changes in the sugar distribution and midgut glucose absorption indicate that insects cover the increased energy needs induced by insecticides; also at the gastrointestinal tract level. The result indicates that the midgut glucose absorption parameters could be considered as a non-specific biomarker of insecticide toxicity.

Serum omentin and vaspin levels in cirrhotic patients with and without portal vein thrombosis

AIM To investigate serum omentin and vaspin levels in cirrhotic patients; and to assess the relationship of these levels with hemostatic parameters, metabolic abnormalities, cirrhosis severity and etiology. METHODS Fifty-one cirrhotic patients (17 with portal vein thrombosis) were analyzed. Serum omentin and vaspin levels were measured with commercially available direct enzyme-linked immunosorbent assays (ELISAs). To assess platelet activity, the following tests were performed using a MULTIPLATE®PLATELET FUNCTION ANALYZER: (1) an ADP-induced platelet activation test; (2) a cyclooxygenase dependent aggregation test (ASPI test); (3) a von Willebrand factor and glycoprotein Ib-dependent aggregation (using ristocetin) test (RISTO test); and (4) a test for thrombin receptor-activating peptide-6 induced activation of the thrombin receptor, which is sensitive to IIb/IIIa receptor antagonists. RESULTS Omentin, but not vaspin, serum concentrations were significantly decreased in patients with portal vein thrombosis (PVT) (P = 0.01). Prothrombin levels were significantly increased in patients with PVT (P = 0.01). The thrombin receptor activating peptide (TRAP) test results were significantly lower in the PVT group (P = 0.03). No significant differences in adipokines serum levels were found regarding the etiology or severity of liver cirrhosis assessed according to the Child-Pugh or Model of End-Stage Liver Disease (MELD) scores. There was a significant increase in the TRAP (P = 0.03), ASPI (P = 0.001) and RISTO high-test (P = 0.02) results in patients with lower MELD scores. Serum omentin and vaspin levels were significantly down-regulated in patients without insulin resistance (P = 0.03, P = 0.02, respectively). A positive relationship between omentin and vaspin levels were found both when all of the patients were analyzed (r = 0.41, P = 0.01) and among those with PVT (r = 0.94, P < 0.001). CONCLUSION Serum omentin levels are increased in patients without PVT. Cirrhosis origin and grade do not affect omentin and vaspin levels. The analyzed adipokines do not influence platelet activity.

Hepatic chemerin mRNA in morbidly obese patients with nonalcoholic fatty liver disease

The aim of this study was to investigate hepatic chemerin mRNA, serum chemerin concentration, and immunohistochemical staining for chemerin and and chemokine receptor-like 1 (CMKLR1) in hepatic tissue in 56 morbidly obese women with nonalcoholic fatty liver disease (NAFLD) and to search for a relationship with metabolic and histopathological features. Chemerin mRNA was assessed by quantitative real-time PCR, chemerin, and CMKLR1 immunohistochemical expression with specific antibodies, while serum chemerin concentration was assessed with commercially available enzyme-linked immunosorbent assays. Serum chemerin concentration reached 874.1 ±234.6 ng/ml. There was no difference in serum chemerin levels between patients with BMI < 40 kg/m2 and ≥ 40 kg/m2. Serum chemerin concentration tended to be higher in patients with hepatocyte ballooning, greater extent of steatosis, and definite nonalcoholic steatohepatitis (NASH). Liver chemerin mRNA was observed in all included patients and was markedly, but insignificantly, higher in those with BMI ≥ 40 kg/m2, hepatocyte ballooning, greater extent of steatosis, and definite NASH. Hepatic chemerin mRNA might be a predictor of hepatic steatosis, hepatocyte ballooning, and NAFLD activity score (NAS) but seemed not to be a primary driver regulating liver necroinflammatory activity and fibrosis. The lack of association between serum chemerin and hepatic chemerin mRNA may suggest that adipose tissue but not the liver is the main source of chemerin in morbidly obese women.

Ileal transposition in rats influenced glucosemetabolism and HSP70 levels

Abstract Objective: Ileal transposition procedure (IT), in combination with sleeve gastrectomy, is widely used to induce diabetes remission and to control related metabolic abnormalities. A transposition of a long segment of distal ileum in obese Zucker rats improved glucose tolerance 6 months after IT. The premise of our study was to to examine the long - term effects of ileum transposition on the liver glycolytic enzymes content in a euglycemic group of operated Zucker rats. Methods: Twenty male Zucker rats underwent either the transposition of 50% distal ileum or a sham surgery. Six months after surgery, liver tissue concentrations of glycogen synthase kinase alpha (GSK-3α), glucose 6-phosphatase (G6PC), glycogen phosphorylase (PYGM) and phosphofructokinase (PFK) and HSP70 were assessed by immunoenzymatic methods. Results: HSP70 values were significantly higher in the IT group compared to SHAM. G6PC liver concentrations in the IT group were almost 1.45-fold lower than in the SHAM operated rats. Statistical analyses (F-test) showed HSP70 levels were significantly related to caveolin-1and SHAM group. Conclusions: Lowered glycolytic enzyme concentrations assessed in the liver suggest positive effects on glucose metabolism in long-term observations.

Changes of Plasma FABP4, CRP, Leptin, and Chemerin Levels in relation to Different Dietary Patterns and Duodenal-Jejunal Omega Switch Surgery in Sprague–Dawley Rats

Background Pathophysiological links between inflammation, obesity, and adipokines can be used for the treatment of metabolic dysregulation. Aims To examine the influence of duodenal-jejunal omega switch surgery in combination with different diet patterns on plasma concentrations of fatty acid-binding protein 4 (FABP4), C-reactive protein (CRP), leptin, and chemerin. Methods After 8 weeks on a high-fat diet (HF) or control diet (CD), rats underwent surgery. Duodenal-jejunal omega switch (DJOS) with an exclusion of one-third of intestinal length and SHAM surgery were performed. For the next 8 weeks, 50% of DJOS/SHAM animals were kept on the same diet as before (HF/DJOS/HF, HF/SHAM/HF, CD/DJOS/CD, and CD/SHAM/CD), and 50% had a changed diet (HF/DJOS/CD, HF/SHAM/CD, CD/DJOS/HF, and CD/SHAM/HF). FABP4, CRP, leptin, and chemerin were assessed using ELISA kits. Results FABP4: significant differences between DJOS and SHAM were observed in animals maintained on CD/CD; CRP: varied between DJOS and SHAM groups maintained on HF/HF, CD/CD, and CD/HF; leptin and chemerin levels: DJOS lowered leptin and chemerin plasma levels versus SHAM, while HF/HF, CD/HF, and HF/CD significantly increased leptin and chemerin plasma levels when compared to CD/CD. Conclusions The beneficial effect of DJOS surgery is stronger than proinflammatory conditions caused by an HF obesogenic diet.

Antioxidant Status in the Soleus Muscle of Sprague-Dawley Rats in Relation to Duodenal-Jejunal Omega Switch and Different Dietary Patterns

Background Obesity and chronic ingestion of lipid-rich meals are related to an enhanced oxidative stress (OS). Aims To examine the influence of duodenal-jejunal omega switch surgery in combination with different diets on the antioxidative status in the soleus muscle of rats. Methods After 8 weeks on a high-fat diet (HF) or control diet (CD), rats underwent duodenal-jejunal omega switch (DJOS) or SHAM (control) surgery. After surgery, for the next 8 weeks, half of DJOS/SHAM animals were kept on the same diet as before, and half had a changed diet. The total superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR) activity as well as malondialdehyde (MDA) concentration were measured in the soleus of rats. Results CAT and GPx activity were significantly lower after DJOS surgery versus SHAM, regardless of the type of diet. The activity of CAT, SOD, GR, CuZnSOD, and GPx was altered in the CD/HF or HF/CD groups. After DJOS, the lowest muscle concentration of MDA was observed in the CD/CD group and the highest in CD/HF. Conclusions DJOS surgery significantly decreases the antioxidative system in soleus muscles of rats. CD/HF and HF/CD dietary patterns lead to an increase in antioxidative activity, while remaining on unchanged diet (CD or HF) is associated with a reduced oxidative stress.

Ileal Transposition (IT) Surgery Changing the Ultrastructure of the Transposed Segment as well as Jejunum. Histomorphometric and Electron Microscopy Analysis

ObjectiveIleal transposition (IT) procedure leads to higher secretion of incretin hormones what is associated with a beneficial metabolic effect. However, IT will also have an influence on the related jejunum and ileum function. The aim of this research was to investigate the morphology of the jejunum and transposed ileum with the use of light and transmission electron microscopy (TEM) in order to determine the local alternations in the intestine resulting from the transposition.MethodsTwenty male, 8-week-old, obese Zucker rats underwent IT and six of them sham surgery. To compare both groups, the transection was made at all corresponding ileum positions among both groups of animals. The ileal anastomoses among the rats of sham procedure were subsequently formed accordingly without IT. Three months following the surgery, the tissue samples of jejunum and ileum were harvested.ResultsA significant increase in villus length, a decrease in the crypt depth, and an increased thickness of mucosa-muscularis-serosa (MMS) as well as cellular hyperplasia, with increased mitochondrial density of the transposed ileum segment, were observed among the group of rats which underwent IT comparing to the ones undergoing sham surgery. In rats undergoing IT, microvillus degeneration in jejunum regions was observed.ConclusionsIleal transposition alters the morphology and ultrastructure of the ileum as well as the jejunum. Given that the microvillus membrane represents an important aspect of the enterocyte functions, a further biochemical and molecular research is necessary in order to assess whether the observed changes are beneficial or not and to explore the phenomenon of gut adaptability after metabolic surgery.