[ABDOMINAL OBESITY AND GUT MICROBIOTA (REVIEW)]

In review provides data on pathophysiological relationships of intestinal microbiota with body weight regulation in patients with abdominal obesity. In manuscript discusses the leading mechanisms by which the gut microbiota can contribute to obesity and metabolic diseases, analyzes its components, including gastrointestinal peptides, short-chain fatty acids, bile acids, farnesoid receptors, etc. Western diet high in salt, dysbiosis and endotoxemia can be powerful pro-inflammatory factors responsible for the development of insulin resistance and weight gain. It is promising to prescribe agonists of gastrointestinal peptides, probiotics and prebiotics, which in abdominal obesity are able to inhibit dysbiosis, regulate immune functions, and protect the organism from low-intensity chronic inflammation.

Macrophages and dendritic cells in the development of liver injury leading to liver failure

Liver failure (LF) continues to be a serious problem due to different underlying disorders. Not only hepatocytes but Kupffer cells (KCs) and dendritic cells (DCs) are of importance in this instance. We wanted to investigate the possible role of KCs and liver DCs in the development of liver injury in patients with liver failure. Liver specimens from 23 patients who died after liver failure were examined for the presence and distribution of CD68-positive KCs and CD83-positive DCs by immunohistochemistry. The distribution of the CD83-positive DC in the sinusoidal and the periportal spaces was not even. While 39.1% of patients had a high sinusoidal density of CD83-positive cells, 60.9% demonstrated a high density of CD83-positive cells in the periportal tract. The number of CD83-positive DCs in periportal tracts in patients with advanced liver fibrosis (n=5) were high, while those with mild liver fibrosis (n=18) had low numbers of mature dendritic cells (χ2=4.107; p=0.043). In addition, all patients with intensive fibrosis had low counts of CD68-positive KC’s in portal tracts vs patients with mild fibrosis of which 67% had high counts (χ2=6.97; p=0.008). In seven of the patients with moderate steatosis (87.5%) low numbers of CD68-positive KCs were found in sinusoids, in contrast to those with severe steatosis, where 12 patients (80%) had high KC counts (χ2=13.4; p less than 0.001). The distribution and number of CD68-positive KC and CD83-positive DC reflect the progression of liver fibrosis leading to liver failure.

Escherichia coli exhibits a membrane-related response to a small arginine- and tryptophan-rich antimicrobial peptide

Since multiresistant bacterial strains are more widespread and the victim numbers steadily increase, it is very important to possess a broad bandwidth of antimicrobial substances. Antibiotics often feature membrane-associated effect mechanisms. So, we present a membrane proteomic approach to shed light on the cellular response of Escherichia coli as model organism to the hexapeptide MP196, which is arginine and tryptophan rich. Analyzing integral membrane proteins are still challenging, although various detection strategies have been developed in the past. In particular, membrane proteomics in bacteria have been conducted very little due to the special physical properties of these membrane proteins. To obtain more information on the cellular response of the new compound group of small peptides, the tryptophan- and arginine-rich hexapeptide MP196 was subject to a comprehensive quantitative membrane proteomic study on E. coli by means of metabolic labeling in combination with membrane lipid analyses. This study provides in total 767 protein identifications including 185 integral membrane proteins, from which 624 could be quantified. Among these proteins, 134 were differentially expressed. Thereby, functional groups such as amino acid and membrane biosynthesis were affected, stress response could be observed, and the lipid composition of the membrane was significantly altered. Especially, the strong upregulation of the envelope stress induced protein. Spy indicates membrane damage, as well as the downregulation of the mechano-sensitive channel MscL beside others. Finally, the exceptional downregulation of transport systems strengthens these findings.

Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

A series of small synthetic arginine and tryptophan containing peptides was prepared and analyzed for their antibacterial activity. The effect of N-terminal substitution with metallocenoyl groups such as ferrocene (FcCO) and ruthenocene (RcCO) was investigated. Antibacterial activity in different media, growth inhibition, and killing kinetics of the most active peptides were determined. The toxicity of selected derivatives was determined against erythrocytes and three human cancer cell lines. It was shown that the replacement of an N-terminal arginine residue with a metallocenoyl moiety modulates the activity of WRWRW-peptides against Gram-positive and Gram-negative bacteria. MIC values of 2–6 µM for RcCO-W(RW)₂ and 1–11 µM for (RW)₃ were determined. Interestingly, W(RW)₂-peptides derivatized with ferrocene were significantly less active than those derivatized with ruthenocene which have similar structural but different electronic properties, suggesting a major influence of the latter. The high activities observed for the RcCO-W(RW)₂- and (RW)₃-peptides led to an investigation of the origin of activity of these peptides using several important activity-related parameters. Firstly, killing kinetics of the RcCO-W(RW)₂-peptide versus killing kinetics of the (RW)₃ derivative showed faster reduction of the colony forming units for the RcCO-W(RW)₂-peptide, although MIC values indicated higher activity for the (RW)₃-peptide. This was confirmed by growth inhibition studies. Secondly, hemolysis studies revealed that both peptides did not lead to significant destruction of erythrocytes, even up to 500 µg/mL for (RW)₃ and 250 µg/mL for RcCO-W(RW)₂. In addition, toxicity against three human cancer cell lines (HepG2, HT29, MCF7) showed that the (RW)₃-peptide had an IC₅₀ value of ~140 µM and the RcW(RW)₂ one of ~90 µM, indicating a potentially interesting therapeutic window. Both the killing kinetics and growth inhibition studies presented in this work point to a membrane-based mode of action for these two peptides, each having different kinetic parameters.

[The treatment of reflux esophagitis in patients with a Helicobacter infection of the gastric mucosa]

Among the pathogenetic mechanisms for the occurrence of gastroesophageal reflux disease, Helicobacter pylori infection is indicated. The conclusions are absolutely opposite. The object of our work was to assume ex juvantibus to what extent the eradication of the Helicobacter pylori infection would accelerate the healing of patients with reflux oesophagitis and would reduce the number of relapses. To investigation were submitted 42 patients with reflux oesophagitis with confirmed Helicobacter pylori infection, classified according to Savary-Miller. A group of 22 patients was treated 10 days with triple drug combination of omeprazole, amoxillin and metronidazol with the purpose of eradication of the infection, after which they continued with ranitidin up to 30 days, and a second group of 20 patients treated only with ranitidine for 30 days. The subjective complaints, endoscopic finding and present infection were followed up. A considerably higher number of recovered patients after eradication of the Helicobacter infection was established and the number of relapses for the six-month period of observation was considerably reduced.

[The prevention of ulcer relapses in patients with an ulcerative anamnesis in clinical and endoscopic remission following the eradication of Helicobacter infection of the gastric mucosa]

The contemporary scientific consensus recommends treatment of the Helicobacter pylori infection in patients with history of peptic ulcer independently of the stage of activity. The object of the study was to confirm the necessity for treatment of Helicobacter pylori infection in patients with duodenal peptic ulcer in stage of clinical and endoscopic remission. To investigation were submitted 55 patients divided into in two groups--30 patients treated with triple medicinal combination of metronidasol 2 x 20 mg, amoxycillin 2 x 1000 mg and metronidasol 3 x 500 mg for 7 days. The second group of 25 patients was without medicinal therapy. The observation continued for 12 months. The patients with eradicated Helicobacter pylori infection underwent significantly less relapses, while the quality of their life considerably improved.