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Biomedical subjects

J Gabriel

Publications and source records attributed to J Gabriel.

At least 19 recordsLinked to original sources
PubMed2006

Primary fluorescence (autofluorescence) of fruiting bodies of the wood-rotting fungus Fomes fomentarius.

Autofluorescence of fruiting bodies of the wood-rotting fungus Fomes fomentarius has been observed and is described among native macrofungi for the first time. The strongest yellow autofluorescence with blue excitation was displayed by pith sets, a weaker yellow, yellow-green to yellow-red fluorescence was due to generative thin-walled hyphae while the weakest yellow-reddish fluorescence was emitted by thick-walled skeletal hyphae (though their parts may emit a more intensive yellow fluorescence). This yellow, yellow-green to yellow-red autofluorescence was assessed to be more intensive than the emission described so far in bacteria and fungi (except for lysed hyphae of the fungus Trametes versicolor). With green excitation all F. fomentarius cells emitted strong red autofluorescence.

Fluorescence↗
PubMed2006

Catheter-directed percutaneous transpedicular C2/C3 vertebroplasty in a patient with fibrous dysplasia using seldinger technique.

A 35-year-old man with polyostotic fibrous dysplasia and a massively enlarged skull presented with Lhermitte sensations due to an unstable, mulitseptated, lytic C2/3 vertebral body complex. Enlarged extracranial vasculature made open surgery a high-risk option and limited percutaneous access. A 5F catheter was directed by using a guidewire into the C2/C3 vertebral body complex via a transpedicularly placed biopsy cannula to ensure polymethylmethacrylate deposition throughout the lytic compartments of the vertebral body complex.

Adult↗
PubMed2003

ARC-microscopy--a novel microscopic technique used in microbiological studies.

ARC-microscopy (azimuth relief contrast; a new method of optical microscopy in transmitted light developed in cooperation with Lambda Ltd. Prague) was used to study fungi and algae at both low and higher (480-2880x) magnification. The novel ARC condenser features a higher resolving power, higher contrast and stronger three-dimensional effect than the standard condenser particularly when studying elongated structures that are present in a random orientation in the specimen. The results of these microscopic observations can be used for both morphological (taxonomical) and ecological studies of microorganisms.

Eukaryota↗
PubMed2002

Effect of structure on antibiotic action of new 9-(ethylthio)acridines.

Six new 9-(ethylthio)acridine derivatives were examined for antibacterial and antifungal activities with 10 bacterial and 8 yeast strains. The only active compounds were 2- and 3-amino derivatives. The observed MICs (mg/L) for 2-amino-9-(ethylthio)acridine (possessing the highest biological activity) were 12 (P. mirabilis), 30 (B. subtillis), 60 (C. freundii), 90 (E. coli), 128 (E. vulneris) and 500 (S. marcescens and S. aureus). Both amino derivatives have also lowest half-wave potential (E1/2) and field Swain-Lupton constants (describing oxidoreduction behavior) what supports the importance of acridine ion formation in the mechanism of antimicrobial action.

Acridines↗
PubMed2002

Variability of laccase activity in the white-rot basidiomycete Pleurotus ostreatus.

The production of laccase in liquid cultures of the white-rot fungus Pleurotus ostreatus was highly variable. During the first days of cultivation, the relative variability was as high as 80-100% and it decreased to 30% in the course of cultivation. The main source of variability was assumed to be the independent development of enzyme activity in individual cultures. Cultures with high laccase production showed also high production of the other ligninolytic enzyme--Mn-dependent peroxidase. The variability was probably due to the source of inoculum, deactivation of the enzyme in culture liquid and genetic variations among the cultures. Variability of laccase activities was lower during solid-state fermentation on wheat straw and during the growth in nonsterile soil.

Culture Media↗
PubMed2001

Decolorization of synthetic dyes by the Fenton reagent and the Cu/pyridine/H2O2 system.

Representative azo, triphenylmethane, heterocyclic and polymeric synthetic dyes have been decolorized by two biological non-ezymatic systems, copper/pyridine/H2O2 and the Fenton reagent. With the former system, intensive decolorization measured after 1 h was obtained with phenol red (89%), tropaeolin 00 (58%), Evans blue (95%), eosin yellowish (84%), and Poly B-411 (92%). The rate of decolorization was not affected by pH in the range of 3-9 and increased with increasing temperature. The use of the radical scavengers thiourea and superoxide dismutase showed that hydroxyl radicals rather than superoxide anions are involved in the reaction. Omission of pyridine led to a substantial decrease in the extent of decolorization (20-50% decolorization). The use of organic peroxide instead of H2O2 resulted in slightly slower decolorization, similar values of decolorization being obtained only after a 2-h incubation. Decolorization of the dyes by the Fenton reagent was also very effective but slower than that obtained with the first system. Except for phenol red and eosin yellowish, (decolorization 8% and 52%, respectively) the dyes were decolorized up to 99% after 1-day incubation.

Coloring Agents↗
PubMed2001

Copper sorption by native and modified pellets of wood-rotting basidiomycetes.

AIMS: The aim of this study was to investigate the biosorption of copper to the pellets of different wood-rotting fungal species. METHODS AND RESULTS: Copper sorption was studied in both batch and column arrangements. The optimum pH for copper sorption was between 3.5 and 4. In 100 mg l(-1) Cu (II), maximum qe values were found for Oudemansiella mucida (8.77 mg g(-1) dry wt), Lepista nuda (6.29 mg g(-1)), Pycnoporus cinnabarinus (5.08 mg g(-1)) and Pleurotus ostreatus (4.77 mg g(-1)). Both biomass yield and specific sorption were influenced by the composition of the fermentation broth. The results of column experiments showed that mycelial pellets of wood-rotting fungi can be considered as promising biosorbent material. CONCLUSIONS: Pellets of wood-rotting fungi showed the same or better copper sorption properties as those previously reported for lower fungi or filamentous bacteria, as well as good mechanical properties.

Basidiomycota↗
PubMed2000

Antifungal properties of substituted 1-phenyl-5-mercaptotetrazoles and their oxidation product, 5-bis-(1-phenyltetrazolyl)disulfide.

The antifungal effect of substituted 1-phenyl-5-mercaptotetrazoles was tested with Candida tropicalis, C. pseudotropicalis, C. mogii, Trichosporon cutaneum, Cryptococcus albidus and S. cerevisiae. Candida strains exhibited the lowest sensitivity to the compounds; the most sensitive was S. cerevisiae. The MIC values ranged from 40 to > 1000 mg/mL. The antifungal effect of halogenated compounds decreased in the series of bromo > chloro > fluoro derivatives. The electrochemical oxidation of substituted 1-phenyl-5-mercaptotetrazole derivatives in an acetonitrile medium was studied as a model for the enzymic oxidation of the substance, including study of the effect of water, perchloric and trifluoromethanesulfuric acids on E1/2 and I1. 5-Bis-(1-phenyltetrazolyl)disulfide, the compound with no antifungal effect, has been identified as the main oxidation product of 1-phenyl-5-mercaptotetrazole.

Acetonitriles↗
PubMed2000

Degradation of polycyclic aromatic hydrocarbons by the copper(II)-hydrogen peroxide system.

A non-enzymic system containing CuSO4 (10 mmol/L) and hydrogen peroxide (100 mmol/L) was used for the degradation of three polycyclic aromatic hydrocarbons: phenanthrene, fluoranthene, and pyrene (all at 10 mmol/L). The system degraded the compounds rapidly and efficiently. After 1 d at room temperature, more than 80% of pyrene, phenanthrene, and fluoranthene disappeared. Several products are formed during the reaction including a black precipitate.

Biodegradation, Environmental↗
PubMed2000

Screening of Pleurotus ostreatus isolates for their ligninolytic properties during cultivation on natural substrates.

Thirteen basidiospore-derived isolates of Pleurotus ostreatus f6 strain differing in the level of ligninolytic enzyme production and other characteristics (mycelium extension rate, colony morphology) from the parental strain were cultivated on natural substrates. Under these conditions ligninolytic enzyme activity, loss of organic mass, polycyclic aromatic hydrocarbons (PAHs) degradation and colonization of sterile and nonsterile soil were studied. The activity of ligninolytic enzymes was substantially higher in straw than in liquid culture, although the differences between the isolates were less pronounced on this substrate. Some of the isolates showed a very good ability to decompose the lignocellulosic substrate (straw) and a relatively high loss of organic mass was found after 50 days of cultivation in these strains. The original strain f6 and isolates B13 and B26 successfully degraded all seven tested PAH compounds present in experimental soil samples, but the higher or lower ligninolytic enzyme production of isolates tested had no substantial effect on the extent of the degradation. In our screening, six basidiospore-derived isolates growing well in nonsterile soil were found, which could be suitable for the prospective biotechnological exploitation.

Biodegradation, Environmental↗
PubMed2000

Influence of cadmium and mercury on activities of ligninolytic enzymes and degradation of polycyclic aromatic hydrocarbons by Pleurotus ostreatus in soil.

The white-rot fungus Pleurotus ostreatus was able to degrade the polycyclic aromatic hydrocarbons (PAHs) benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, and benzo[ghi]perylene in nonsterile soil both in the presence and in the absence of cadmium and mercury. During 15 weeks of incubation, recovery of individual compounds was 16 to 69% in soil without additional metal. While soil microflora contributed mostly to degradation of pyrene (82%) and benzo[a]anthracene (41%), the fungus enhanced the disappearance of less-soluble polycyclic aromatic compounds containing five or six aromatic rings. Although the heavy metals in the soil affected the activity of ligninolytic enzymes produced by the fungus (laccase and Mn-dependent peroxidase), no decrease in PAH degradation was found in soil containing Cd or Hg at 10 to 100 ppm. In the presence of cadmium at 500 ppm in soil, degradation of PAHs by soil microflora was not affected whereas the contribution of fungus was negligible, probably due to the absence of Mn-dependent peroxidase activity. In the presence of Hg at 50 to 100 ppm or Cd at 100 to 500 ppm, the extent of soil colonization by the fungus was limited.

Biodegradation, Environmental↗
PubMed1999

Bacterial degradation of the herbicide bromoxynil by Agrobacterium radiobacter in biofilm.

The bromoxynil-degrading soil microorganism Agrobacterium radiobacter was used for degradation of the herbicide under nonsterile batch and continuous conditions. From four types of carrier particles, beech shavings showed the best stability of the bacterial biofilm, bromoxynil concentration in a column reactor decreasing to 65% after 5 d. The efficacy of degradation was enhanced by addition of ferrous, cobaltous or cupric ions.

Bacterial Adhesion↗
PubMed1999

Age of transfused blood is an independent risk factor for postinjury multiple organ failure.

BACKGROUND: Blood transfusion has repeatedly been demonstrated to be an independent risk factor for postinjury multiple organ failure (MOF). Previously believed to represent a surrogate for shock, packed red blood cell (PRBC) transfusion has recently been shown to result in neutrophil priming and pulmonary endothelial cell activation. We have previously observed that the generation of inflammatory mediators is related to the length of PRBC unit storage. The purpose of this study was to determine if age of transfused PRBC is a risk factor for the development of postinjury MOF. METHODS: Using our prospective database of trauma patients at risk for developing MOF, we identified patients who developed MOF (MOF+) and received 6 to 20 units of PRBCs in the first 12 hours following injury. A similar cohort of patients, matched for ISS and transfusion requirement, who did not develop MOF (MOF-) were also identified. The age of each unit of PRBC transfused in the first 6 hours was determined. Multiple logistic regression was performed to determine if age of transfused blood is an independent risk factor. RESULTS: Sixty-three patients were identified, 23 of whom were MOF+. There was no difference in ISS and transfusion requirement between MOF+ and MOF- groups. MOF+ patients, however, were significantly older (46+/-4.7 years versus 33+/-2.3 years). Moreover, mean age of transfused blood was greater in the MOF+ patients (30.5+/-1.6 days versus 24+/-0.5 days). Similarly, the mean number of units older than 14 and 21 days old were greater in the MOF+ patients. Multivariate analysis identified mean age of blood, number of units older than 14 days, and number of units older than 21 days as independent risk factors for MOF. CONCLUSION: The age of transfused PRBCs transfused in the first 6 hours is an independent risk factor for postinjury MOF. This suggests that current blood bank processing and storage technique should be reexamined. Moreover, fresh blood may be more appropriate for the initial resuscitation of trauma patients requiring transfusion.

Adult↗
PubMed1999

First clinical application of a newly developed device for intragastric surgery for the treatment of pancreatic pseudocysts.

BACKGROUND: Instruments that have been used during GI endoscopy have always been confined to the accessory channel of the endoscope. We have therefore developed a device that allows transabdominal manipulation in the stomach under gastroscopic control. Here we report the first clinical application of this device, which was used for the drainage of pancreatic pseudocysts. METHODS: The device is similar to a PEG tube and consists of a 7 mm polyethylene tube that is inserted by the "thread pull through" method. A trocar valve is mounted at the external tip of the tube. Four pseudocysts were treated in three patients. The retrogastric pseudocysts were punctured through the device under endoscopic (n = 2) and CT (n = 2) guidance. External drainage was used for 3 to 5 days; thereafter the drain was cut and internalized. The device was also cut and sealed. After 10 days it was removed as with a standard PEG tube. RESULTS: No complications related to the device occurred. In two patients the pseudocysts resolved completely. One patient had to undergo pseudocystojejunostomy for an infected pseudocyst containing large amounts of necrotic material. CONCLUSIONS: We believe that our new device is valuable to the further development of intragastric surgery and can be used to safely perform pseudocystogastrostomy.

Adult↗
PubMed1999

Neutrophils are primed for cytotoxicity and resist apoptosis in injured patients at risk for multiple organ failure.

BACKGROUND: Postinjury multiple organ failure (MOF) is the result of a dysregulated systemic inflammatory response in which primed neutrophils (PMNs) are sequestered in tissues, vulnerable to activation through secondary insults. Apoptosis is critical to the normal clearance of these sequestered PMNs. Conversely, dysfunctional apoptosis prolongs the PMN functional life span, potentially exacerbating PMN-mediated tissue injury and the development of MOF. We hypothesized that severe trauma, in addition to priming PMNs, provokes dysfunctional PMN apoptosis. METHODS: Neutrophils were harvested daily from 12 severely injured patients at high risk for MOF, cultured for 24 hours, and assessed for apoptosis with use of acridine orange-ethidium bromide staining and fluorescence microscopy. Priming for elastase release was measured in freshly isolated patient PMNs. Plasma from patients was assessed for its ability to delay apoptosis of normal PMNs. RESULTS: Four patients (33%) had MOF. Neutrophil apoptosis was profoundly delayed in severely injured patients throughout the 5-day study period. Priming for elastase release was augmented concomitantly. Patients' plasma delayed apoptosis of normal PMNs. CONCLUSION: In patients at high risk for postinjury MOF, PMNs are not only primed for cytotoxicity but also resist apoptosis. The dysfunctional apoptosis is attributed, at least in part, to a plasma-borne mediator. The net effect may facilitate hyperinflammatory organ injury.

Adolescent↗