Materials used to prevent adhesion, growth, and biofilm formation of Candida species.

The species of the Candida genus are opportunistic pathogenic fungi found in humans and are responsible for ∼80% of worldwide fungal infections. Aimed at diminishing and preventing Candida adhesion to cells or implanted devices in the human host, a large diversity of materials has been developed and functionalized that have attracted much interest. Furthermore, these materials have been focused almost exclusively on Candida albicans, followed by C. glabrata, C. parapsilosis, and C. tropicalis. Although an important diversity of materials has been synthesized to prevent adherence and formation of biofilms by Candida species, it is however important to evaluate the capacity of each material in terms of its property to diminish the adherence of Candida. These materials are discussed in this review.

A review of ferric citrate clinical studies, and the rationale and design of the Ferric Citrate and Chronic Kidney Disease in Children (FIT4KiD) trial.

Pediatric chronic kidney disease (CKD) is characterized by many co-morbidities, including impaired growth and development, CKD-mineral and bone disorder, anemia, dysregulated iron metabolism, and cardiovascular disease. In pediatric CKD cohorts, higher circulating concentrations of fibroblast growth factor 23 (FGF23) are associated with some of these adverse clinical outcomes, including CKD progression and left ventricular hypertrophy. It is hypothesized that lowering FGF23 levels will reduce the risk of these events and improve clinical outcomes. Reducing FGF23 levels in CKD may be accomplished by targeting two key stimuli of FGF23 production-dietary phosphate absorption and iron deficiency. Ferric citrate is approved for use as an enteral phosphate binder and iron replacement product in adults with CKD. Clinical trials in adult CKD cohorts have also demonstrated that ferric citrate decreases circulating FGF23 concentrations. This review outlines the possible deleterious effects of excess FGF23 in CKD, summarizes data from the adult CKD clinical trials of ferric citrate, and presents the Ferric Citrate and Chronic Kidney Disease in Children (FIT4KiD) study, a randomized, placebo-controlled trial to evaluate the effects of ferric citrate on FGF23 in pediatric patients with CKD stages 3-4 (ClinicalTrials.gov Identifier NCT04741646).

A GDPase/UDPase bifunctional enzyme from Candida albicans: purification and biochemical characterization.

The most frequently isolated human fungal pathogen is Candida albicans which is responsible for about 50% of all Candida infections. In healthy individuals, this organism resides as a part of the normal microbiota in equilibrium with the host. However, under certain conditions, particularly in immunocompromised patients, this opportunistic pathogen adheres to host cells causing serious systemic infections. Thus, much effort has been dedicated to the study of its physiology with emphasis on factors associated to pathogenicity. A representative analysis deals with the mechanisms of glycoprotein assembly as many cell surface antigens and other macromolecules that modulate the immune system fall within this chemical category. In this regard, studies of the terminal protein glycosylation stage which occurs in Golgi vesicles has led to the identification of nucleotidases that convert glycosyltransferase-generated dinucleotides into the corresponding mononucleotides, thus playing a double function: their activity prevent inhibition of further glycosyl transfer by the accumulation of dinucleotides and the resulting mononucleotides are exchanged by specific membrane transporters for equimolecular amounts of sugar donors from the cytosol. Here, using a simple protocol for protein separation we isolated a bifunctional nucleotidase from C. albicans active on GDP and UDP that was characterized in terms of its molecular mass, response to bivalent ions and other factors, substrate specificity and affinity. Results are discussed in terms of the similarities and differences of this nucleotidase with similar counterparts from other organisms thus contributing to the knowledge of a bifunctional diphosphatase not described before in C. albicans.

Responses of Sporothrix globosa to the cell wall perturbing agents Congo Red and Calcofluor White.

It is well documented that disturbance of cell surface by some agents triggers compensatory responses aimed to maintain the cell wall integrity in fungi and other organisms. Here, the thermodimorphic fungus Sporothrix globosa, a member of the pathogenic clade of the Sporothrix complex, was propagated in yeast-peptone-dextrose medium under conditions to obtain the mycelium (pH 4.5, 27-28 °C) or the yeast (pH 7.8, 32-34 °C) morphotypes in the absence and presence of the wall-interacting dyes Congo Red (CR) and Calcofluor White (CFW) either alone or in combination. After different periods of time, growth, cell morphology and activity of glucosamine-6-phosphate synthase (GlcN-6-P synthase), an ubiquitous enzyme that plays a crucial role in cell wall biogenesis, were determined. CR and to a lower extent CFW affected growth and morphology of both fungal morphotypes and significantly increased enzyme activity. Notoriously, CR or CR in combination with CFW induced the transient conversion of yeasts into conidia-forming filamentous cells even under culture conditions adjusted for yeast development, most likely as a strategy to evade the noxious effect of the dye. After sometime, hypha returned to yeast cells. An hypothetical model to explain the effect of CR on morphology and enzyme activity based on the possible role of membrane-spanning proteins known as mechanosensors is proposed. Results are discussed in terms of the fungal responses to cell wall damage.

Quantification of non-structural carbohydrates in different tissues of trees with diffuse reflectance spectroscopy: Is there a benefit from a fusion of near- and mid-infrared data?

Understanding the role of non-structural carbohydrates (NSC) in tree-level carbon cycling crucially depends on the availability of NSC data in a sufficient temporal resolution covering extreme conditions and seasonal peaks or declines. Chemical analytical methods should therefore get complemented by less extensive retrieval methods. To this end, we explored the potential of diffuse reflectance spectroscopy for estimating NSC contents at a set of 180 samples taken from leaves, roots, stems and branches of different tree species in different biogeographic regions. Multiple randomized partitioning in calibration and validation data were performed with near-infrared (NIR) and mid-infrared (MIR) as well as combined data. With derivative spectra, NIR markedly outperformed MIR data for NSC estimation; mean RMSE for outer validation samples equalled 2.58 (in % of dry matter) compared to 2.90, r2 was 0.64 compared to 0.52. We found complementary information related to NSC in both spectral domains, so that a combination with high-level data fusion (model averaging) increased accuracy (RMSE decreased to 2.19, r2 equalled 0.72). Spectral variable selection with the CARS algorithm further improved results slightly (RMSE = 1.97, r2 = 0.78). On the level of tissue types, we found a marked differentiation concerning the appropriateness of datasets and approaches. High-level data fusion was successful for leaves, NIR data (together with CARS) provided the best results for wooden tissues. This suggests further studies with a greater number of samples per tissue type but only for selected (main) tree species to finally judge the sensitivities of diffuse reflectance spectroscopy (NIR, MIR) for NSC retrieval.

Neutrophil-to-lymphocyte ratio may predict complications and patency in bile duct injury repair.

BACKGROUND: Bile duct injury (BDI) repair surgery is usually associated with morbidity/mortality. The neutrophil-to-lymphocyte ratio (NLR) easily assesses a patient's inflammatory status. The study aims to determine the possible relationship between preoperative NLR (pNLR) with postoperative outcomes in BDI repair surgery. METHODS: Approved Ethics/Research Committee retrospective study, in patients who had a Bismuth-Strasberg type E BDI repair (2008-2023). Data registered was: morbidity, mortality, and long-term outcomes (primary patency and loss of primary patency) (Kaplan-Meier). Group comparison (U Mann-Whitney), receiver operator characteristic (ROC): area under curve [AUC]; cut-off value, and Youden index [J], and logistic regression analysis were used for pNLR evaluation. RESULTS: Seventy-three patients were studied. Mean age was 44.4 years. E2 was the commonest BDI (38.4%). Perioperative morbidity/mortality was 31.5% and 1.4%. Primary patency was 95.9%. 8.2% have lost primary patency (3-year actuarial patency: 85.3%). Median pNLR was higher in patients who had any complication (4.84 vs. 2.89 p = 0.015), biliary complications (5.29 vs. 2.86 p = 0.01), and patients with loss of primary patency (5.22 vs. 3.1 p = 0.08). AUC's, cut-off values and (J) were: any complication (0.678, pNLR = 4.3, J = 0.38, p = 0.007), serious complication (0.667, pNLR = 4.3, J = 0.34, p = 0.04), biliary complications (0.712, pNLR = 3.64, J = 0.46, p = 0.001), and loss of primary patency (0.716, pNLR = 3.24, J = 0.52, p = 0.008). Logistic regression was significant in any complication (Exp [B]: 0.1, p = 0.002), serious complications (Exp [B]: 0.2, p = 0.03), and biliary complications (Exp [B]: 8.1, p = 0.003). CONCLUSIONS: pNLR is associated with complications in BDI repair with moderate to acceptable predictive capacity. pNLR could potentially predict patency of a BDI repair.

Studies on drug metabolism by fungi colonizing decomposing human cadavers. Part I: DNA sequence-based identification of fungi isolated from postmortem material.

Cadavers can be colonized by a wide variety of bacteria and fungi. Some of these microbes could change the concentration or the metabolic pattern of drugs present in postmortem samples. The purpose of this study was to identify fungi from human postmortem material and to further assess their potential role in the metabolism of drugs. Aliquots of 252 postmortem samples (heart blood, liver, kidney, and lung) taken from 105 moderately to severely decomposed bodies were streaked on Sabouraud agar for isolation of fungal species. One part of the samples was worked up immediately after autopsy (group I). The second part had previously been stored at -20 °C for at least 1 year (group II). Identification of the isolates was achieved morphologically by microscopy and molecularly by polymerase chain reaction amplification and sequencing of markers allowing species identification of the respective genera. Depending on the genus, different gene fragments were used: calmodulin for Aspergillus, ß-tubulin for Penicillium, translation elongation factor 1α for Fusarium, and the internal transcribed spacer region of the ribosomal DNA for all remaining genera. A total of 156 fungal strains were isolated from 62% of the postmortem materials. By using these primers, 98% of the isolates could be identified to the species level. The most common genera were Candida (60.0%-six species), Penicillium (10.3%-two species), Rhodotorula (7.1%-one species), Mucor (6.4%-four species), Aspergillus (3.2%-four species), Trichosporon (3.2%-one species), and Geotrichum (3.2%-one species). Group I samples contained 53% more fungal species than stored samples suggesting some fungi did not survive the freezing process. The isolated fungi might be characteristic for decomposed bodies. The proposed methodology proved to be appropriate for the identification of fungi in this type of material.

Fungal Glycosidases in Sporothrix Species and Candida albicans.

Glycoside hydrolases (GHs) are enzymes that participate in many biological processes of fungi and other organisms by hydrolyzing glycosidic linkages in glycosides. They play fundamental roles in the degradation of carbohydrates and the assembly of glycoproteins and are important subjects of studies in molecular biology and biochemistry. Based on amino acid sequence similarities and 3-dimensional structures in the carbohydrate-active enzyme (CAZy), they have been classified in 171 families. Members of some of these families also exhibit the activity of trans-glycosydase or glycosyl transferase (GT), i.e., they create a new glycosidic bond in a substrate instead of breaking it. Fungal glycosidases are important for virulence by aiding tissue adhesion and colonization, nutrition, immune evasion, biofilm formation, toxin release, and antibiotic resistance. Here, we review fungal glycosidases with a particular emphasis on Sporothrix species and C. albicans, two well-recognized human pathogens. Covered issues include a brief account of Sporothrix, sporotrichosis, the different types of glycosidases, their substrates, and mechanism of action, recent advances in their identification and characterization, their potential biotechnological applications, and the limitations and challenges of their study given the rather poor available information.

Excess protein O-GlcNAcylation and the progression of diabetic cardiomyopathy.

We examined the role that enzymatic protein O-GlcNAcylation plays in the development of diabetic cardiomyopathy in a mouse model of Type 2 diabetes mellitus (DM2). Mice injected with low-dose streptozotocin and fed a high-fat diet developed mild hyperglycemia and obesity consistent with DM2. Studies were performed from 1 to 6 mo after initiating the DM2 protocol. After 1 mo, DM2 mice showed increased body weight, impaired fasting blood glucose, and hyperinsulinemia. Echocardiographic evaluation revealed left ventricular diastolic dysfunction by 2 mo and O-GlcNAcylation of several cardiac proteins and of nuclear transcription factor Sp1. By 4 mo, systolic dysfunction was observed and sarcoplasmic reticulum Ca(2+) ATPase expression decreased by 50%. Fibrosis was not observed at any timepoint in DM2 mice. Levels of the rate-limiting enzyme of the hexosamine biosynthetic pathway, glutamine:fructose-6-phosphate amidotransferase (GFAT) were increased as early as 2 mo. Fatty acids, which are elevated in DM2 mice, can possibly be linked to excessive protein O-GlcNAcylation levels, as cultured cardiac myocytes in normal glucose treated with oleic acid showed increased O-GlcNAcylation and GFAT levels. These data indicate that the early onset of diastolic dysfunction followed by the loss of systolic function, in the absence of cardiac hypertrophy or fibrosis, is associated with increased cardiac protein O-GlcNAcylation and increased O-GlcNAcylation levels of key calcium-handling proteins. A link between excessive protein O-GlcNAcylation and cardiac dysfunction is further supported by results showing that reducing O-GlcNAcylation by O-GlcNAcase overexpression improved cardiac function in the diabetic mouse. In addition, fatty acids play a role in stimulating excess O-GlcNAcylation. The nature and time course of changes observed in cardiac function suggest that protein O-GlcNAcylation plays a mechanistic role in the triggering of diabetic cardiomyopathy in DM2.

Studies on the metabolism of five model drugs by fungi colonizing cadavers using LC-ESI-MS/MS and GC-MS analysis.

It is well-known that cadavers may be colonized by microorganisms, but there is limited information if or to what extent these microbes are capable of metabolizing drugs or poisons, changing the concentrations and metabolic pattern of such compounds in postmortem samples. The aim of the present study was to develop a fungal biotransformation system as an in vitro model to investigate potential postmortem metabolism by fungi. Five model drugs (amitriptyline, metoprolol, mirtazapine, promethazine, and zolpidem) were each incubated with five model fungi known to colonize cadavers (Absidia repens, Aspergillus repens, Aspergillus terreus, Gliocladium viride, and Mortierella polycephala) and with Cunninghamella elegans (positive control). Incubations were performed in Sabouraud medium at 25 °C for 5 days. After centrifugation, a part of the supernatants was analyzed by liquid chromatography-tandem mass spectrometry with product ion scanning. Another part was analyzed by full scan gas chromatography-mass spectrometry after extraction and derivatization. All model drugs were metabolized by the control fungus resulting in two (metoprolol) to ten (amitriptyline) metabolites. Of the model fungi, only Abs. repens and M. polycephala metabolized the model drugs: amitriptyline was metabolized to six and five, metoprolol to two and two, mirtazapine to five and three, promethazine to six and nine, and zolpidem to three and four metabolites, respectively. The main metabolic reactions were demethylation, oxidation, and hydroxylation. The presented in vitro model is applicable to studying drug metabolism by fungi colonizing cadavers.

Cell compensatory responses of fungi to damage of the cell wall induced by Calcofluor White and Congo Red with emphasis on Sporothrix schenckii and Sporothrix globosa. A review.

The cell wall (CW) of fungi exhibits a complex structure and a characteristic chemical composition consisting almost entirely of interacting crystalline and amorphous polysaccharides. These are synthesized by a number of sugar polymerases and depolymerases encoded by a high proportion of the fungal genome (for instance, 20% in Saccharomyces cerevisiae). These enzymes act in an exquisitely coordinated process to assemble the tridimensional and the functional structure of the wall. Apart from playing a critical role in morphogenesis, cell protection, viability and pathogenesis, the CW represents a potential target for antifungals as most of its constituents do not exist in humans. Chitin, ß-glucans and cellulose are the most frequent crystalline polymers found in the fungal CW. The hexosamine biosynthesis pathway (HBP) is critical for CW elaboration. Also known as the Leloir pathway, this pathway ends with the formation of UDP-N-GlcNAc after four enzymatic steps that start with fructose-6-phosphate and L-glutamine in a short deviation of glycolysis. This activated aminosugar is used for the synthesis of a large variety of biomacromolecules in a vast number of organisms including bacteria, fungi, insects, crustaceans and mammalian cells. The first reaction of the HBP is catalyzed by GlcN-6-P synthase (L-glutamine:D-fructose-6-phosphate amidotransferase; EC 2.6.1.16), a critical enzyme that has been considered as a potential target for antifungals. The enzyme regulates the amount of cell UDP-N-GlcNAc and in eukaryotes is feedback inhibited by the activated aminosugar and other factors. The native and recombinant forms of GlcN-6-P synthase has been purified and characterized from both prokaryotic and eukaryotic organisms and demonstrated its critical role in CW remodeling and morphogenesis after exposure of some fungi to agents that stress the cell surface by interacting with wall polymers. This review deals with some of the cell compensatory responses of fungi to wall damage induced by Congo Red and Calcofluor White.

Thyroid hormone inhibits ERK phosphorylation in pressure overload-induced hypertrophied mouse hearts through a receptor-mediated mechanism.

Pressure overload-induced cardiac hypertrophy results in a pathological type of hypertrophy with activation of signaling cascades like the extracellular signal-regulated kinase (ERK) pathway, which promotes negative cardiac remodeling and decreased contractile function. In contrast, thyroid hormone mediates a physiological type of hypertrophy resulting in enhanced contractile function. In addition, thyroid hormone action is diminished in pressure overload-induced cardiac hypertrophy. We hypothesized that thyroid hormone status modulates ERK activity and that administration of thyroid hormone could alter the activity of this kinase in cardiac hypertrophy induced by pressure overload. ERK is activated by phosphorylation; accordingly, we investigated phosphorylation of ERK in hearts of control, hypothyroid, and hyperthyroid mice. In addition, the effect of T3 treatment on ERK phosphorylation in hypertrophied hearts from transverse aortic-constricted (TAC) mice was investigated. Results showed that phosphorylated ERK (p-ERK) was decreased by 25% in hyperthyroid mice. In contrast, hypothyroid mice presented increased p-ERK by 80%. TAC mice presented a greater than fourfold increase of p-ERK compared with control mice. Interestingly, T3 administration dramatically canceled TAC-induced ERK phosphorylation (36% lower compared with control). Raf-1 is upstream of the ERK pathway. TAC mice presented a 45% increase in phospho-Raf-1 (Ser338). T3 treatment inhibited this effect of pressure overload and further decreased p-Raf-1 (Ser338) by 37%, compared with control. Overexpression of thyroid hormone receptor-α in cultured cardiomyocytes potentiated the inhibitory effect of T3 on ERK phosphorylation. We concluded that thyroid hormone has an inhibitory effect on the Raf-1/ERK pathway. Furthermore, treatment of TAC mice with T3 inhibited Raf-1/ERK pathway by a thyroid hormone receptor-dependent mechanism.

Analytical toxicology of emerging drugs of abuse.

The emergence of ever new drugs of abuse on the illicit drug market is an ongoing challenge for analytical toxicologists. Because most of these new drugs or drug classes are not detected by established analytical methods targeting classic drugs of abuse, analytical procedures must be adapted or new procedures must be developed to cover these new compounds. This review summarizes the analytical toxicology of the following classes of emerging drugs of abuse: piperazines, phenethylamines (2Cs and FLYs), 4-substituted amphetamines, ß-keto-amphetamines, 2,5-dimethoxy-amphetamines, pyrrolidinophenones, and synthetic cannabinoids.

Complex Above- and Below-Ground Growth Responses of Two Urban Tree Species Following Root, Stem, and Foliage Damage-An Experimental Approach.

Urban trees are subjected to numerous biotic and mechanical damages, which can affect their growth rates and health. However, for most species, a systematic analysis of tree above- and below-ground growth reactions to a variety of damages is still lacking. Under a fully factorial experimental setup, using two common urban trees (Celtis occidentalis, Fraxinus pennsylvanica), we tested the effects of various degrees of frequently occurring damage as defoliation, root reduction, and stem injuries for a total of 18 treatments. We hypothesized that (i) an increasing amount of damage would proportionally negatively affect both root and stem growth; (ii) there would be a lag or lasting effect on growth; and (iii) both species would react similarly to the treatments. Contrary to our expectation, increasing levels of single or combined damage did not have an incremental effect on either stem or root growth. Although Celtis was significantly less vigorous than Fraxinus, it did not react strongly to damage treatments compared to the control. Interestingly, Celtis that experienced stem damage alone or in combination with other damages showed higher growth rates than the control. For Celtis, root injury was the treatment having the most impact, decreasing both root and stem growth consistently throughout the 5 years following treatments, whereas defoliation decreased growth only in the first 2 years. All damage treatments negatively affected stem and root growth of Fraxinus trees. Stem growth was affected the most by defoliation in the first year following the treatment, while root injury became the driving factor in subsequent years. For both species, stem injury showed the least influence on growth rates. The control and low-level damage treatments often affected growth rates in a similar way, suggesting that low-intensity stress triggers compensatory reactions stimulating photosynthetic rates and nutrient utilization. The slower-growing tree species, Celtis, showed a less negative reaction to all damage treatments compared to Fraxinus. This study illustrates that various types of above- and below-ground injuries do not have a simple additive effect on tree growth and that trees are capable of compensating for the loss of foliage, roots, or phloem to meet their metabolic demand.

Flood risk (d)evolution: Disentangling key drivers of flood risk change with a retro-model experiment.

Flood risks are dynamically changing over time. Over decades and centuries, the main drivers for flood risk change are influenced either by perturbations or slow alterations in the natural environment or, more importantly, by socio-economic development and human interventions. However, changes in the natural and human environment are intertwined. Thus, the analysis of the main drivers for flood risk changes requires a disentangling of the individual risk components. Here, we present a method for isolating the individual effects of selected drivers of change and selected flood risk management options based on a model experiment. In contrast to purely synthetic model experiments, we built our analyses upon a retro-model consisting of several spatio-temporal stages of river morphology and settlement structure. The main advantage of this approach is that the overall long-term dynamics are known and do not have to be assumed. We used this model setup to analyse the temporal evolution of the flood risk, for an ex-post evaluation of the key drivers of change, and for analysing possible alternative pathways for flood risk evolution under different governance settings. We showed that in the study region the construction of lateral levees and the consecutive river incision are the main drivers for decreasing flood risks over the last century. A rebound effect in flood risk can be observed following an increase in settlements since the 1960s. This effect is not as relevant as the river engineering measures, but it will become increasingly relevant in the future with continued socio-economic growth. The presented approach could provide a methodological framework for studying pathways for future flood risk evolvement and for the formulation of narratives for adapting governmental flood risk strategies to the spatio-temporal dynamics in the built environment.

[Development of a computer program to simulate the predictions of the replaced elements model of Pavlovian conditioning]. / Desarrollo de un programa computacional para simular las predicciones del modelo de elementos reemplazados (REM) de condicionamiento pavloviano.

Despite of the apparent simplicity of Pavlovian conditioning, research on its mechanisms has caused considerable debate, such as the dispute about whether the associated stimuli are coded in an "elementistic"(a compound stimuli is equivalent to the sum of its components) or a "configural" (a compound stimuli is a unique exemplar) fashion. This controversy is evident in the abundant research on the contrasting predictions of elementistic and the configural models. Recently, some mixed solutions have been proposed, which, although they have the advantages of both approaches, are difficult to evaluate due to their complexity. This paper presents a computer program to conduct simulations of a mixed model ( replaced elements model or REM). Instructions and examples are provided to use the simulator for research and educational purposes.

Effect of selection for growth rate on the ageing of myofibrils, meat texture properties and the muscle proteolytic potential of m. longissimus in rabbits.

The effect of selection for growth rate on the degradation of the myofibrillar proteins and on meat texture properties of rabbit longissimus muscle at two ageing times (1 and 7 days) was studied as well as its effect on the proteolytic potential of the muscle. Two groups of contemporary animals (20 rabbits per group), one selected for growth rate (S) for 14 generations and the other unselected control group (C) were compared. The control group was formed from the offspring of the embryos belonging to the 7th generation and was compared with selected animals belonging to 21st generation. Myofibrillar protein degradation was studied by SDS-PAGE electrophoresis (12.5% and 4-15% polyacrylamide gels) followed by densitometric analysis of the pherograms. Texture properties were evaluated by Warner-Bratzler (WB) test and Texture profile analysis (TPA). The activities of proteolytic enzymes calpains and cathepsins and of their inhibitors were determined in the muscle at 24h. Densitometric analysis of the pherograms of samples aged 7 days showed an extra 30kDa band and the disappearance of a band with higher molecular weight than the myosin heavy chain with respect to samples aged 24h in both groups of rabbits. TPA results showed that cohesiveness was significantly lower in meat at 7 days than at 24h (P<0.0001), whereas springiness and chewiness presented a clear tendency to be lower at 7 days than at 24h (P=0.0646 and P=0.0764, respectively). Regarding the genetic type, S animals presented higher hardness and chewiness than C rabbits. Shear firmness (WB test) was significantly (P<0.0001) higher for S group, whereas no significant differences in shear force and area were found. No significant effect (P>0.05) of ageing time was detected using WB test. Selection for growth rate did not affect the activities of proteolytic enzymes or their inhibitors.

Search for fungi-specific metabolites of four model drugs in postmortem blood as potential indicators of postmortem fungal metabolism.

Fungi colonizing cadavers are capable of drug metabolism and may thus change the metabolite pattern or concentration of drugs in forensic postmortem samples. The purpose of this study was to check for the presence of such changes by searching fungi-specific metabolites of four model drugs (amitriptyline, metoprolol, mirtazapine, and zolpidem) in decomposed postmortem blood samples from 33 cases involving these drugs. After isolation and identification of fungal strains present in the samples, each isolate was incubated in Sabouraud medium at 25°C for up to 120h with each model drug. One part of the supernatants was directly analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), another after liquid-liquid extraction with chlorobutane and concentration. From 21 out of 33 decomposed postmortem blood samples (64%) a total of 30 different strains could be isolated, one from the class of Ascomycete and the rest belonging to 15 species from 8 different genera (number of species): Aspergillus (2), Botrytis (1), Candida (8), Fusarium (1), Mucor (1), Penicillium (1), and Rodothorula (1). In the in vitro studies, these microorganisms were found capable of N-demethylation and N-oxidation of amitriptyline and mirtazapine, O-demethylation followed by side chain oxidation of metoprolol as well as hydroxylation of all four-model drugs. In two of the postmortem blood samples, from which the fungi Aspergillus jensenii, Candida parapsilosis. and Mucor circinelloides had been isolated, a fungi-specific hydroxy zolpidem metabolite was detected. The presence of this metabolite in postmortem samples likely indicates postmortem fungal biodegradation.

Studies on drug metabolism by fungi colonizing decomposing human cadavers. Part II: biotransformation of five model drugs by fungi isolated from post-mortem material.

The present study investigated the in vitro metabolic capacity of 28 fungal strains isolated from post-mortem material towards five model drugs: amitriptyline, metoprolol, mirtazapine, promethazine, and zolpidem. Each fungal strain was incubated at 25 °C for up to 120 h with each of the five models drugs. Cunninghamella elegans was used as positive control. Aliquots of the incubation mixture were centrifuged and 50 µL of the supernatants were diluted and directly analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with product ion scanning. The remaining mixture was analyzed by full scan gas chromatography-mass spectrometry (GC-MS) after liquid-liquid extraction and acetylation. The metabolic activity was evaluated through the total number of detected metabolites (NDM) produced in each model and fungal strains and the percentage of parent drug remaining (%RPD) after up to five days of incubation. All the tested fungal strains were capable of forming mammalian phase I metabolites. Fungi from the normal fungal flora of the human body such as Candida sp., Geotrichum candidum, and Trichosporon asahii) formed up to seven metabolites at %RPD values greater than 52% but no new fungal metabolites (NFM). In contrast, some airborne fungal strains like Bjerkandera adusta, Chaetomium sp, Coriolopsis sp., Fusarium solani and Mucor plumbeus showed NDM values exceeding those of the positive control, complete metabolism of the parent drug in some models and formation of NFM. NFM (numbers in brackets) were detected in four of the five model drugs: amitriptyline (18), metoprolol (4), mirtazapine (8), and zolpidem (2). The latter NFM are potential candidates for marker substances indicating post-mortem fungal metabolism.

Acute Kidney Injury and Fluid Overload in Neonates Following Surgery for Congenital Heart Disease.

BACKGROUND: Acute kidney injury (AKI) and fluid overload have been shown to increase morbidity and mortality. The reported incidence of AKI in pediatric patients following surgery for congenital heart disease is between 15% and 59%. Limited data exist looking at risk factors and outcomes of AKI or fluid overload in neonates undergoing surgery for congenital heart disease. METHODS: Neonates aged 6 to 29 days who underwent surgery for congenital heart disease and who were without preoperative kidney disease were included in the study. The AKI was determined utilizing the Acute Kidney Injury Network criteria. RESULTS: Ninety-five neonates were included in the study. The incidence of neonatal AKI was 45% (n = 43), of which 86% had stage 1 AKI. Risk factors for AKI included cardiopulmonary bypass time, selective cerebral perfusion, preoperative aminoglycoside use, small kidneys by renal ultrasound, and risk adjustment for congenital heart surgery category. There were eight mortalities (five from stage 1 AKI group, three from stage 2, and zero from stage 3). Fluid overload and AKI both increased hospital length of stay and postoperative ventilator days. CONCLUSION: To avoid increased risk of morbidity and possibly mortality, every attempt should be made to identify and intervene on those risk factors, which may be modifiable or identifiable preoperatively, such as small kidneys by renal ultrasound.