Determination of antimicrobial activity of Achatina reticulata slime.

BACKGROUNDS: Snails (Gastropoda) have a mechanism for the production of a significant amount of slime and substances contained therein they use to protect themselves against bacterial or fungal pathogens. These active substances are involved in both humoral and cellular immune responses of the gastropods. The antibacterial or antifungal effect of the humoral immune component of slime lies in cytotoxic and haemagglutination activity against potential microbial pathogens. The activity of antibacterial agents present in Achatina reticulata slime against bacterial strains of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa was tested. MATERIAL AND METHODS: A total of five samples of slime from laboratory reared Achatina reticulata were tested. To eliminate potential microbial contamination, slime samples were sterilized by UV radiation. To screen slime samples for antibacterial activity, the simple diffusion method on Mueller-Hinton agar was used. Samples diluted in guaiacol glycerol ether were used in the testing. RESULTS: The results show that the biologically active substances present in Achatina reticulata slime have an antimicrobial activity which is almost commensurate with that of the conventional antibiotics used to treat bacterial infections. The results of the determination of the antimicrobial effects of Achatina reticulata slime also highlighted viridation (partial hemolysis of erythrocytes after 24 hours of slime cultivation exposed to UV light for 60 minutes on Columbia blood agar. CONCLUSIONS: The results of the antimicrobial activity testing of selected Achatina reticulata slime samples show that the gastropod slime contains biologically active substances with a relatively significant antimicrobial activity.

GABA spectra and remote distractor effect in progressive supranuclear palsy: A pilot study.

Disturbances of the gamma-aminobutyric-acid (GABA) system have been suspected of contributing to the pathophysiology of progressive supranuclear palsy (PSP). The ability to rapidly resolve competitive action decisions, such as shifting the gaze to one particular stimulus rather than another, can be predicted by the concentration of GABA in the region of the frontal cortex relevant to eye movements. For this reason, our study measured GABA levels in seven PSP patients and eight healthy controls, using proton magnetic resonance spectroscopy, and assessed the relationship of these measurements to the remote distractor effect (RDE), an eye-movement paradigm investigating competitive action decisions. No significant differences were found in either frontal-eye-field GABA levels or RDE between PSP patients and controls.

[Flow cytometry in microbiology]. / Prutoková cytometrie v mikrobiologii.

Flow cytometry is a method that allows simultaneous measurement and analysis of physical and chemical characteristics of cells or other biological particles during their passage through the laser beam. Although this method is mainly used in the study of cell differentiation and functional analysis of eukaryotic cells, the basic principles of flow cytometry can be applied to microorganisms. Methods based on the analysis of a single cell, such as flow cytometry, in combination with measurement of cell viability using special fluorescent probes allow a deeper insight into the diversity of populations and functioning of microbial communities and also facilitate understanding the phy-siological diversity of seemingly similar acting populations. When using specific fluorescent dyes for the selective labeling of selected species of microorganisms, the method is potentially very specific. The aim of this paper is a brief overview of applications of flow cytometry, which can be used in microbiology.

The age dependence of T2 relaxation times of N-acetyl aspartate, creatine and choline in the human brain at 3 and 4T.

Knowledge of the T2 age dependence is of importance for MRS clinical studies involving subject groups with a wide age range. A number of studies have focused on the age dependence of T2 values in the human brain, with rather conflicting results. The aim of this study was to analyze the age dependence of T2 values of N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) in the human brain using data acquired at 3T and 4T and to assess the influence of the macromolecule (MM) baseline handling on the obtained results. Two distinct groups of young and elderly controls have been measured at 3T (TE = 30-540 ms, 9 young and 11 elderly subjects) and 4T (TE = 10-180 ms, 18 young and 14 elderly subjects) using single-voxel spectroscopy. In addition, MM spectra were measured from two subjects using the inversion-recovery technique at 4T. All spectra were processed with LCModel using basis sets with different MM signals (measured or simulated) and also with MM signals included for a different TE range. Individual estimated T2 values were statistically analyzed using the R programming language for the age dependence of T2 values as well as the influence of the MM baseline handling. A significant decrease of T2 values of NAA and Cr in elderly subjects compared with young subjects was confirmed. The same trend was observed for Cho. Significantly higher T2 values calculated using the measured MM baseline for all studied metabolites at 4T were observed for both young and elderly subjects. To conclude, while the handling of MM and lipid signals may have a significant effect on estimated T2 values, we confirmed the age dependence of T2 values of NAA and Cr and the same trend for Cho in the human brain. Copyright © 2016 John Wiley & Sons, Ltd.

[The effect of oxygen on endotoxin production in bacteria of the Bacteroides fragilis group isolated from patients with colorectal carcinoma]. / Vliv kyslíku na produkci endotoxinu u bakterií ze skupiny Bacteroides fragilis group izolovaných od pacientu s kolorektálním karcinomem.

OBJECTIVE: The aim of the study was to draw attention to the risk posed by anaerobic bacteria of the Bacteroides fragilis (BAFR) group, isolated particularly from abdominal lesions, and to assess the possible role of these species in colorectal cancer. A correlation has previously been suggested between the detection of the bacteria of the genus Bacteroides in patients on a meat-based diet and intestinal and, in particular, colorectal cancer. Given that the species of the BAFR group are major producers of endotoxins, measurements and statistical analysis of endotoxin production were used to compare the Bacteroides strains isolated from clinical specimens of patients with colon cancer, rectal cancer, and other abdominal lesions. MATERIALS AND METHODS: Endotoxin production was detected in bacterial strains of the BAFR group (B. fragilis, B. thetaiotaomicron, B. distasonis, and B. vulgatus) isolated from clinical specimens of patients with rectal cancer, colon cancer, and intestinal cancer and was compared with that in strains from samples of patients with inflammatory conditions (anal abscess, appendicitis, skin abscess, etc.) under anaerobic and microaerophilic (with 5% of oxygen) culture conditions. The production of endotoxins was detected quantitatively using the Pyrosate LAL assay kit (Limulus Amoebocyte Lysate Test, BIOGENIX, CR) in four species of the BAFR group after anaerobic and microaerophilic culture. Five strains of each isolated Bacteroides species from each type of specimens were tested (in total 140 BAFR strains). The amount of endotoxin was given in endotoxin units per ml (EU/ml). RESULTS: Endotoxin production by bacteria under microaerophilic culture conditions was several times higher in comparison with strictly anaerobic culture.The difference was statistically significant (F1.269 = 160, p <0.0001). As regards the effect of oxygen on endotoxin production, the amount of endotoxins produced under microaerophilic culture conditions (average 889.1 EU/ml) was 2.5 times as high as that observed under anaerobic culture conditions (358.2 EU/ml), regardless of the bacteroides species and diagnosis. These results suggest that the amount of free oxygen in the environment affects the amount of endotoxin generated by the Bacteroides strains. CONCLUSION: The results show that endotoxin production by the Bacteroides strains under microaerophilic culture conditions is several times as high as that under strictly anaerobic culture conditions.

Analysis of EURADOS neutron intercomparison results according to new ISO standards criteria.

The European Radiation Dosimetry Group has carried out several different types of intercomparison (IC) exercises in the past that qualify as proficiency tests for different dosimetry systems and types of radiation. The first neutron dosemeter IC was held in 2012 (IC2012n) and was followed by a second in 2017/2018 (IC2017n). In sum, 31 Individual Monitoring Services (IMSs) entered 34 dosimetry systems in IC2012n, and 32 IMSs entered 33 dosimetry systems for IC2017n. Such exercises provided a rare opportunity to see how neutron dosemeters perform. For the IC2012n exercise, there were no applicable performance standards for neutron personal dosemeters. ISO/TC85/SC2 updated the ISO Standard 14146 in 2018 (ISO 14146:2018. Radiation protection-Criteria and performance limits for the periodic evaluation of dosimetry services) to include neutron dosimetry. It was thus possible to analyse the IC2017n exercise in accordance with the requirements given by this new standard. It is now of interest to reanalyse the results of IC2012n to quantify any modifications to the conclusions.

Detection of pancreatic islet allograft impairment in advance of functional failure using magnetic resonance imaging.

This study evaluated the ability of magnetic resonance imaging (MRI) to predict failure of pancreatic islets (PI) transplanted into the hepatic portal vein. Brown-Norway (n = 18) and Lewis (n = 6) rats received islets isolated from Lewis donors. The rejection process in Brown-Norway recipients was mitigated by two different immunosuppressive regimens [tacrolimus + hydrocortisone for 3 months (n = 6) or tacrolimus for 12 days (n = 12)]. Longitudinal MRI monitoring of recipients at post-transplantation weeks 1, 2, 3, 4, 6, 8, 10, and 12 confirmed the ability to detect SPIO labeled PI after transplantation into the liver. The relative number of MRI signals related to PI isografts remained stable up to study completion. Recipients of PI allografts were normoglycemic until the end of study; signals declined gradually to 44 ± 17% in these animals. In animals with islets failure during post-transplant week 12, the number of signals decreased to 25 ± 10% of initial values. The difference between groups (islet function/failed) became significant post-transplant week 3. Our data demonstrate that the MRI changes attributable to rejection become apparent within 3 weeks after transplantation, i.e. at least 8 weeks before functional allograft failure.

Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes.

AIMS: The aim of this study was to compare the effects of calorie-restricted vegetarian and conventional diabetic diets alone and in combination with exercise on insulin resistance, visceral fat and oxidative stress markers in subjects with Type 2 diabetes. METHODS: A 24-week, randomized, open, parallel design was used. Seventy-four patients with Type 2 diabetes were randomly assigned to either the experimental group (n = 37), which received a vegetarian diet, or the control group (n = 37), which received a conventional diabetic diet. Both diets were isocaloric, calorie restricted (-500 kcal/day). All meals during the study were provided. The second 12 weeks of the diet were combined with aerobic exercise. Participants were examined at baseline, 12 weeks and 24 weeks. Primary outcomes were: insulin sensitivity measured by hyperinsulinaemic isoglycaemic clamp; volume of visceral and subcutaneous fat measured by magnetic resonance imaging; and oxidative stress measured by thiobarbituric acid reactive substances. Analyses were by intention to treat. RESULTS: Forty-three per cent of participants in the experimental group and 5% of participants in the control group reduced diabetes medication (P < 0.001). Body weight decreased more in the experimental group than in the control group [-6.2 kg (95% CI -6.6 to -5.3) vs. -3.2 kg (95% CI -3.7 to -2.5); interaction group × time P = 0.001]. An increase in insulin sensitivity was significantly greater in the experimental group than in the control group [30% (95% CI 24.5-39) vs. 20% (95% CI 14-25), P = 0.04]. A reduction in both visceral and subcutaneous fat was greater in the experimental group than in the control group (P = 0.007 and P = 0.02, respectively). Plasma adiponectin increased (P = 0.02) and leptin decreased (P = 0.02) in the experimental group, with no change in the control group. Vitamin C, superoxide dismutase and reduced glutathione increased in the experimental group (P = 0.002, P < 0.001 and P = 0.02, respectively). Differences between groups were greater after the addition of exercise training. Changes in insulin sensitivity and enzymatic oxidative stress markers correlated with changes in visceral fat. CONCLUSIONS: A calorie-restricted vegetarian diet had greater capacity to improve insulin sensitivity compared with a conventional diabetic diet over 24 weeks. The greater loss of visceral fat and improvements in plasma concentrations of adipokines and oxidative stress markers with this diet may be responsible for the reduction of insulin resistance. The addition of exercise training further augmented the improved outcomes with the vegetarian diet.

Positive contrast visualization of SPIO-labeled pancreatic islets using echo-dephased steady-state free precession.

OBJECTIVE: MRI has recently been introduced as a promising method of monitoring the transplanted pancreatic islets labelled with superparamagnetic iron oxide (SPIO). However, the traditional [Formula: see text]-weighted approach frequently yields ambiguous results because of the negative contrast of the SPIO particles on the background of other body components. This obstacle could be overcome with the use of a novel method known as echo-dephased steady state free precession (SSFP), generating positive contrast in the presence of paramagnetic material. METHODS: In phantoms, we achieved exact localisation and clear positive contrast visualisation of human SPIO labelled islets. Using the proposed method we demonstrated the ability to detect even a single pancreatic islet against a homogeneous background. RESULTS: In vivo experiments in rats confirmed reliable and accurate localisation of transplanted SPIO labelled islets. CONCLUSION: The echo-dephased SSFP technique could successfully visualise SPIO-labelled human and rat pancreatic islets yielding a positive contrast.

Acute responses of hepatic fat content to consuming fat, glucose and fructose alone and in combination in non-obese non-diabetic individuals with non-alcoholic fatty liver disease.

We have recently demonstrated that a high-fat load can induce immediate increase in hepatic fat content (HFC) and that such an effect can be modified differently by co-administration of fructose or glucose in healthy subjects. Therefore, we addressed the question how consumption of these nutrients affects changes in HFC in subjects with non-alcoholic fatty liver disease (NAFLD). Eight male non-obese non-diabetic patients with NAFLD underwent 6 experiments each lasting 8 hours: 1. fasting, 2. high-fat load (150 g of fat (dairy cream) at time 0), 3. glucose (three doses of 50 g at 0, 2, and 4 hours), 4. high-fat load with three doses of 50 g of glucose, 5. fructose (three doses of 50 g at 0, 2, and 4 hours), 6. high-fat load with three doses of 50 g of fructose. HFC was measured using magnetic resonance spectroscopy prior to meal administration and 3 and 6 hours later. Plasma triglycerides, non-esterified fatty acids, glucose and insulin were monitored throughout each experiment. HFC increased by 10.4 ± 6.9% six hours after a high-fat load and by 15.2 ± 12.5% after high-fat load with fructose. When co-administering glucose with fat, HFC rose only transiently to return to baseline at 6 hours. Importantly, NAFLD subjects accumulated almost five times more fat in their livers than healthy subjects with normal HFC. Consumption of a high-fat load results in fat accumulation in the liver of NAFLD patients. Fat accumulation after a fat load is diminished by glucose but not fructose co-administration.

CHARACTERISATION OF RADIOPHOTOLUMINESCENCE DOSIMETRY SYSTEM FOR INDIVIDUAL MONITORING.

Performance evaluation is typically assessed as part of the approval procedure to verify that a dosimetry system fulfils specified national or international type-test requirements under representative exposure conditions that are expected to mimic workplace fields from the radiological activities being monitored. The International Atomic Energy Agency Radiation Safety Technical Services Laboratory has recently implemented an integrated radiophotoluminescence (RPL) personal dosimetry system developed by Chiyoda Technol Corporation. This paper reports on the successful verification of dosimetric performance properties of the RPL dosimetry system to IEC 62387:2020, in which the badges were exposed to a range of radiation energies and angles of incidence as well as other influence parameters. Characteristics under test included the coefficient of variation, non-linearity of response due to dose dependence as well as the energy and angular response to photon and beta radiation.

[Septic shock in a patient with the Fournièr gangrene with fatal outcome]. / Septický sok u pacienta s Fournièrovou gangrénou s fatálním koncem.

AIM: The authors present a case of a patient with developed Fournièr gangrene and septic shock. Fournièr gangrene belongs to the group of local non-specific infection of soft tissues (NSTI). Its incidence is relatively low, but the infection is extraordinary aggressive with a possible lethal end. MATERIAL AND METHOD: 39 years old patient with 4 days history of Fournier gangrene's development was admitted in irreversible septic shock. The initial APACHE II score was 36. The delay in treatment was an important factor in the further course of illness with lethal end. RESULTS: Above the mentioned 39 years old patient died because of septic shock. The hemorrhagic cystitis was the original source of infection with further development of Fournièr gangrene according to the pathological record. CONCLUSION: We often come across all different kinds of stages of sepsis from the MODS to the septic shock for patients with Fournièr gangrene. Causal treatment should be started early. The local surgical excision and wide broad antibiotic administrations are basic treatments in the context of other treatment modalities according to the current patient's needs. The adjuvant hyperbaric oxygen treatment takes place in patients with Fournièr gangrene as well and is beneficial. The following factor even worsens the illness prognosis: delay in diagnostic, higher age, anorectal origin of infection, the amount of organ with dysfunction or failure, diabetes mellitus and significant immunodeficiency.

A Trimodal Imaging Platform for Tracking Viable Transplanted Pancreatic Islets In Vivo: F-19 MR, Fluorescence, and Bioluminescence Imaging.

PURPOSE: Combining specific and quantitative F-19 magnetic resonance imaging (MRI) with sensitive and convenient optical imaging provides complementary information about the distribution and viability of transplanted pancreatic islet grafts. In this study, pancreatic islets (PIs) were labeled with positively charged multimodal nanoparticles based on poly(lactic-co-glycolic acid) (PLGA-NPs) with encapsulated perfluoro-15-crown-5-ether and the near-infrared fluorescent dye indocyanine green. PROCEDURES: One thousand and three thousand bioluminescent PIs were transplanted into subcutaneous artificial scaffolds, which served as an alternative transplant site. The grafts were monitored using in vivo F-19 MR, fluorescence, and bioluminescence imaging in healthy rats for 2 weeks. RESULTS: Transplanted PIs were unambiguously localized in the scaffolds by F-19 MRI throughout the whole experiment. Fluorescence was detected in the first 4 days after transplantation only. Importantly, in vivo bioluminescence correlated with the F-19 MRI signal. CONCLUSIONS: We developed a trimodal imaging platform for in vivo examination of transplanted PIs. Fluorescence imaging revealed instability of the fluorescent dye and its limited applicability for longitudinal in vivo studies. A correlation between the bioluminescence signal and the F-19 MRI signal indicated the fast clearance of PLGA-NPs from the transplantation site after cell death, which addresses a major issue with intracellular imaging labels. Therefore, the proposed PLGA-NP platform is reliable for reflecting the status of transplanted PIs in vivo.

Clinical and (31)P magnetic resonance spectroscopy characterization of patients with critical limb ischemia before and after autologous cell therapy.

Autologous cell therapy (ACT) is a new treatment method for diabetic patients with critical limb ischemia (CLI) not eligible for standard revascularization. After intramuscular injection of bone marrow-derived mononuclear cells local arteriogenesis in the ischemic tissue occurs. Studies assessing visualization of this therapeutic vasculogenesis after ACT by novel imaging techniques are lacking. The aim of our study was to assess the effect of ACT on possible metabolic changes and perfusion of critically ischemic limbs using (31)P magnetic resonance spectroscopy ( (31)P MRS) and its possible correlation with changes of transcutaneous oxygen pressure (TcPO(2)). Twenty-one patients with diabetes and no-option CLI treated by ACT in our foot clinic over 8 years were included in the study. TcPO(2) as well as rest (phosphocreatine, adenosine triphosphate and inorganic phosphate) and dynamic (mitochondrial capacity and phosphocreatine recovery time) (31)P-MRS parameters were evaluated at baseline and 3 months after cell treatment. TcPO(2) increased significantly after 3 months compared with baseline (from 22.4±8.2 to 37.6±13.3 mm Hg, p=0.0002). Rest and dynamic (31)P MRS parameters were not significantly different after ACT in comparison with baseline values. Our study showed a significant increase of TcPO(2) on the dorsum of the foot after ACT. We did not observe any changes of rest or dynamic (31)P MRS parameters in the area of the proximal calf where the cell suspension has been injected into.

Do we really apply fast-track surgery?

AIM: The aim of this study is to show the current view on fast-track programs optimizing the perioperative care. METHODS: Authors searched Medline databases and identified current trials regarding all factors of fast-track programs. They analyzed these trials and identified the most important principles of fast-track programs based on trial analysis. RESULTS: The most important principles are consistent in all individual trials. Most of authors recommend 10-12 issues. All authors emphasize early mobilization of patients after surgery and early introduction of peroral nutrition. Fast-track programs shorten the duration of hospitalisation and decrease morbidity. CONCLUSION: The perioperative care is characterized by a range of trussing traditions. Fast-track surgery optimizes the perioperative care. It is a safe method according to the trials. The implementation of single fast-track surgery factors is very slow (Tab. 2, Ref. 49).

Differences in muscle metabolism in patients with type I diabetes - influence of gender and nephropathy studied by (31)P MR spectroscopy.

Type I diabetes mellitus (DM1) is a complex disease with adverse effects on organs and tissues despite compensation by insulin treatment. The goal of our study was to study how kidney diseases change (31)P MR parameters of muscle metabolism in DM1 patients with respect to gender. 51 DM1 patients (19 m/14 f without and 13 m/5 f with nephropathy) and 26 (14 m/12 f) healthy volunteers were examined using (31)P magnetic resonance spectroscopy at 3T tomograph at rest, and during and after a calf muscle exercise. The exercise consisted of a six-minute plantar flexion using a pedal ergometer followed by a six-minute recovery. It is reflected by reduced relative beta-ATP and increased Pi and phosphodiester signals to phosphocreatine (PCr) at rest and prolongation of the PCr recovery time after the exercise. Measurement on healthy volunteers indicated differences between males and females in pH at the rest and after the exercise only. These differences between patients groups were not significant. We have proven that nephropathy affects the metabolism in diabetic patients and our results confirm significant difference between patients with and without nephropathy. Gender differences in pH were observed only between male and female healthy volunteers.

Lesion evolution after gamma knife irradiation observed by magnetic resonance imaging.

PURPOSE: Our study is focused on the magnetic resonance imaging (MRI) observation of lesion development and hippocampus related functional impairments in rats after irradiation with a Leksell Gamma knife (LGK). MATERIALS AND METHODS: We exposed 32 three-month-old Long-Evans rats to various radiation doses (25 Gy, 50 Gy or 75 Gy). The rats were scanned by a 4.7 T magnetic resonance (MR) spectrometer at several timepoints (1 - 18 months) after irradiation. The lesion size was evaluated by manual segmentation; the animals were behaviorally tested in a Morris water maze and examined histologically. RESULTS: We found that a dose of 25 Gy induced no edema, necrosis or behavioral change. The response of the rats to higher doses was not uniform; the first occurrence of lesions in the rat brains irradiated with 50 and 75 Gy was detected six months post-irradiation. Functional impairment correlated well with the lesion size and histology. CONCLUSIONS: Rat brains showed the development of expanding delayed lesions after 50 or 75 Gy doses from the LGK during the first year after irradiation.

Composite hyaluronate-type I collagen-fibrin scaffold in the therapy of osteochondral defects in miniature pigs.

The potential of novel scaffold containing sodium hyaluronate, type I collagen, and fibrin was investigated in the regeneration of osteochondral defects in miniature pigs. Both autologous chondrocyte-seeded scaffolds and non-seeded scaffolds were implanted into two defects located in the non-weight-bearing zone of the femoral trochlea (defect A was located more distally and medially, defect B was located more proximally and laterally). Control defects were left untreated. Twelve weeks after the operation, the knees were evaluated in vivo using MRI. Six months after the implantation, the defects were analyzed using MRI, histological, and immunohistochemical analysis. In the A defects of chondrocyte-seeded scaffold group, hyaline cartilage and fibrocartilage was formed, containing type II collagen, acidic and neutral glycosaminoglycans while the non-seeded scaffold group was predominantly filled with fibrocartilage. Defects in the control group were predominantly filled with fibrous tissue. Histomorphometric analysis of photomicrographs revealed a significantly higher amount of hyaline cartilage in the cell-seeded scaffold group in A defects than in other groups. Both scaffold groups in A defects showed significantly less fibrous tissue than cell-seeded defects B and the control group. Both histological and MRI analysis proved that the novel composite scaffold has a potential to regenerate osteochondral defects within six months.