Post-operative reflux esophagitis as a predictor of choice of restrictive operation in patients with metabolic syndrome.

The purpose of this study was to conduct a comparative analysis of the retrospective results of laparoscopic sleeve gastrectomy (LSG), laparoscopic gastroplication (LGP) and laparoscopic fundogastroplication (LFGP) (simultaneous performance of fundoplication by Nissen and gastroplication) obtained at the follow-up period of 1 year, to evaluate and compare the effectiveness of prevention of short-term postoperative complications, which are manifested in the form of GERD, by performing preventive antireflux procedure in combination with restrictive bariatric surgery. Evaluation of the effectiveness and long-term effects of the presented restrictive operations was carried out on the basis of retrospective data obtained during the supervision of 46 patients with obesity and metabolic syndrome (men / women - 16/30, average age – 41.19±6.07, body weight – 128.26±7.37 kg, abdominal circumference – 133.4±4.71 cm, body mass index (BMI) – 42.66±2.41 kg/m2, I-III ASA). In the preoperative and postoperative periods, during consultations, in all patients measurements of anthropometric indicators were performed, laboratory data and results of instrumental research were considered. All metabolic procedures presented were performed at the basis of the Department of Surgery and Vascular Surgery of NMAPE named after P.L. Shupik in the period from 2016 to 2019. 13 patients underwent LSG, 20 – LGP and 13 - LFGP. In order to control the results, repeated consultations were carried out at 1, 3, 6 and 12 months of the postoperative period. The average duration of the operation was: LSG – 88.5±6.49 min, LGP - 120±5.42 min, LFGP – 135.38±7.48 min. The average period of hospitalization was: LSG – 3.2±0.63 days, LGP – 3.53±0.62 days, and LFGP – 3.5±0.67 days. After a year, the body mass index (BMI) was: LSG – 31.17±0.31 kg/m2, LGP – 32.48±0.23 kg/m2, LFGP – 32.43±0.21 kg/m2. According to the results of a repeated questio­ning of patients one year after the operation, 3 (23.07%) of the LSG group and 5 (25.0%) of the LGP group had symptoms of GERD, which failed to be eliminated with the help of conservative therapy, life quality of patients became significantly worse. In the group of patients who underwent LFGP, this complication was absent. After the control gastroscopy, 1 year after, de novo signs of reflux esophagitis were detected (according to the Los Angeles clas­sification): in the LSG group – 3 (23.07%) patients (2 - grade A and 1 - grade B), in the LGP group – 5 (25.0%) patients (3 – grade A and 2 – grade B). Among patients who underwent LFGP, there were no signs of reflux esophagitis. Considering the possible development of GERD and reflux esophagitis in one year after the restrictive surgery, the use of preventive measures consisting in the simultaneous performance of antireflux and metabolic operations is relevant, this is demonstrated by the example of LFGP. We recommend to give preference to simultaneous operations for the achievement of not only high rates of weight loss, but also for improvement of the quality of patients` life in the future

Optimized high gradient magnetic separation for isolation of Plasmodium-infected red blood cells

<p>Abstract</p> <p>Background</p> <p>Highly purified infected red blood cells (irbc), or highly synchronized parasite cultures, are regularly required in malaria research. Conventional isolation and synchronization rely on density and osmotic fragility of irbc, respectively. High gradient magnetic separation (HGMS) offers an alternative based on intrinsic magnetic properties of irbc, avoiding exposure to chemicals and osmotic stress. Successful HGMS concentration in malaria research was previously reported using polymer coated columns, while HGMS depletion has not been described yet. This study presents a new approach to both HGMS concentration and depletion in malaria research, rendering polymer coating unnecessary.</p> <p>Methods</p> <p>A dipole magnet generating a strong homogenous field was custom assembled. Polypropylene syringes were fitted with one-way stopcocks and filled with stainless steel wool. Rbc from <it>Plasmodium falciparum </it>cultures were resuspended in density and viscosity optimized HGMS buffers and HGMS processed. Purification and depletion results were analysed by flow cytometer and light microscopy. Viability was evaluated by calculating the infection rate after re-culturing of isolates.</p> <p>Results</p> <p>In HGMS concentration, purity of irbc isolates from asynchronous cultures consistently ranged from 94.8% to 98.4% (mean 95.7%). With further optimization, over 90% of isolated irbc contained segmented schizonts. Processing time was less than 45 min. Reinfection rates ranged from 21.0% to 56.4%. In HGMS depletion, results were comparable to treatment with sorbitol, as demonstrated by essentially identical development of cultures.</p> <p>Conclusion</p> <p>The novel HGMS concentration procedure achieves high purities of segmented stage irbc from standard asynchronous cultures, and is the first HGMS depletion alternative to sorbitol lysis. It represents a simple and highly efficient alternative to conventional irbc concentration and synchronization methods.</p

Oleic Acid Biosynthesis in Plasmodium falciparum: Characterization of the Stearoyl-CoA Desaturase and Investigation as a Potential Therapeutic Target

BACKGROUND:Plasmodium falciparum parasitization of erythrocytes causes a substantial increase in the levels of intracellular fatty acids, notably oleic acid. How parasites acquire this monounsaturated fatty acid has remained enigmatic. Here, we report on the biochemical and enzymatic characterization of stearoyl-CoA desaturase (SCD) in P. falciparum. METHODOLOGY/PRINCIPAL FINDINGS:Metabolic labeling experiments allowed us to demonstrate the production of oleic acid from stearic acid both in lysates of parasites incubated with [(14)C]-stearoyl-CoA and in parasite-infected erythrocytes labeled with [(14)C]-stearic acid. Optimal SCD activity was detected in schizonts, the stage of maximal membrane synthesis. This activity correlated with a late trophozoite stage-specific induction of PFE0555w transcripts. PFE0555w harbors a typical SCD signature. Similar to mammalian SCDs, this protein was found to be associated with the endoplasmic reticulum, as determined with PFE0555w-GFP tagged transgenic P. falciparum. Importantly, these parasites exhibited increased rates of stearic to oleic acid conversion, providing additional evidence that PFE0555w encodes the plasmodial SCD (PfSCD). These findings prompted us to assess the activity of sterculic acid analogues, known to be specific Delta9-desaturase inhibitors. Methyl sterculate inhibited the synthesis of oleic acid both with parasite lysates and infected erythrocytes, most likely by targeting PfSCD. This compound exhibited significant, rapid and irreversible antimalarial activity against asexual blood stages. This parasiticidal effect was antagonized by oleic acid. CONCLUSION/SIGNIFICANCE:Our study provides evidence that parasite-mediated fatty acid modification is important for blood-stage survival and provides a new strategy to develop a novel antimalarial therapeutic based on the inhibition of PfSCD

Characterization of the Plasmodium falciparum M17 leucyl aminopeptidase. A protease involved in amino acid regulation with potential for antimalarial drug development

Amino acids generated from the catabolism of hemoglobin by intra-erythrocytic malaria parasites are not only essential for protein synthesis but also function in maintaining an osmotically stable environment, and creating a gradient by which amino acids that are rare or not present in hemoglobin are drawn into the parasite from host serum. We have proposed that a Plasmodium falciparum M17 leucyl aminopeptidase (PfLAP) generates and regulates the internal pool of free amino acids and therefore represents a target for novel antimalarial drugs. This enzyme has been expressed in insect cells as a functional 320-kDa homo-hexamer that is optimally active at neutral or alkaline pH, is dependent on metal ions for activity, and exhibits a substrate preference for N-terminally exposed hydrophobic amino acids, particularly leucine. PfLAP is produced by all stages in the intra-erythrocytic developmental cycle of malaria but was most highly expressed by trophozoites, a stage at which hemoglobin degradation and parasite protein synthesis are elevated. The enzyme was located by immunohistochemical methods and by transfecting malaria cells with a PfLAP-green fluorescent protein construct, to the cytosolic compartment of the cell at all developmental stages, including segregated merozoites. Amino acid dipeptide analogs, such as bestatin and its derivatives, are potent inhibitors of the protease and also block the growth of P. falciparum malaria parasites in culture. This study provides a biochemical basis for the antimalarial activity of aminopeptidase inhibitors. Availability of functionally active recombinant PfLAP, coupled with a simple enzymatic readout, will aid medicinal chemistry and/or high throughput approaches for the future design/discovery of new antimalarial drugs