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Engine oil forms a complex system with a number of features. These features consist of hydrocarbons, various natural, or synthetic polymers. The irradiation of polymers becomes an integral part of modern industry. The lubrication, charge, thermal and cleaning requirements, which engine oils are expected to meet, are often chemically contradictory and manufacturers have to decide to compromise. Electron accelerators are widely used to enhance polymer properties. By applying radiation technology, it is possible to increase the desirable properties of polymers while leaving other properties at their original value. The paper focuses on combustion engine oil modified by e-beam. The assessed engine oil has a hydrocarbon base, which, from the chemical point of view, is processed as a polymer during the irradiation process. In this paper we have compared selected properties of the conventional and the irradiated engine oil during two exchange intervals. We have examined appropriate dose, dose rate, irradiation volume and a container on a single accelerated electrons energy. The examined oil properties were of a physical and physico-chemical nature, and included mainly kinematic viscosity, viscosity index, the total base number, soot content, oxidation, sulfation, significant chemical elements and wear particles. Every oil attribute is compared with its original value. The main objective of this paper is to demonstrate that the application of e-beam is an adequate method used to enhance engine oil properties to achieve cleaner engine running, and extend engine oil lifetime. [ABSTRACT FROM AUTHOR]

Syntrophic cooperation among prokaryotes is ubiquitous and diverse. It relies on unilateral or mutual aid that may be both catalytic and metabolic in nature. Hypotheses of eukaryotic origins claim that mitochondrial endosymbiosis emerged from mutually beneficial syntrophy of archaeal and bacterial partners. However, there are no other examples of prokaryotic syntrophy leading to endosymbiosis. One potential reason is that when externalized products become public goods, they incite social conflict due to selfish mutants that may undermine any mutualistic interactions. To rigorously evaluate these arguments, here we construct a general mathematical framework of the ecology and evolution of different types of syntrophic partnerships. We do so both in a general microbial and in a eukaryogenetic context. Studying the case where partners cross-feed on each other's self-inhibiting waste, we show that cooperative partnerships will eventually dominate over selfish mutants. By contrast, systems where producers actively secrete enzymes that cross-facilitate their partners' resource consumption are not robust against cheaters over evolutionary time. We conclude that cross-facilitation is unlikely to provide an adequate syntrophic origin for endosymbiosis, but that cross-feeding mutualisms may indeed have played that role. [ABSTRACT FROM AUTHOR]

Proteolytic activation of the renal epithelial sodium channel (ENaC) is increased by aldosterone. The aldosterone-sensitive protease remains unidentified. In humans, elevated circulating aldosterone is associated with increased urinary extracellular vesicle (uEVs) excretion of mannan-binding lectin associated serine protease-2 (MASP-2). We hypothesized that MASP-2 is a physiologically relevant ENaC-activating protease. It was confirmed that MASP2 mRNA is abundantly present in liver but not in human and mouse kidneys. Aldosterone-stimulation of murine cortical colleting duct (mCCD) cells did not induce MASP-2 mRNA. In human kidney collecting duct, MASP-2 protein was detected in AQP2-negative/ATP6VB1-positive intercalated cells suggestive of MASP2 protein uptake. Plasma concentration of full-length MASP-2 and the short splice variant MAp19 were not changed in a cross-over intervention study in healthy humans with low (70 mmol/day) versus high (250 mmol/day) Na+ intake despite changes in aldosterone. The ratio of MAp19/MASP-2 in plasma was significantly increased with a high Na+ diet and the ratio correlated with changes in aldosterone and fractional Na+ excretion. MASP-2 was not detected in crude urine or in uEVs. MASP2 activated an amiloride-sensitive current when co-expressed with ENaC in Xenopus oocytes, but not when added to the bath solution. In monolayers of collecting duct M1 cells, MASP2 expression did not increase amiloride-sensitive current and in HEK293 cells, MASP-2 did not affect γENaC cleavage. MASP-2 is neither expressed nor co-localized and co-regulated with ENaC in the human kidney or in urine after low Na+ intake. MASP-2 does not mediate physiological ENaC cleavage in low salt/high aldosterone settings. [ABSTRACT FROM AUTHOR]

Patient knowledge of risk factors, signs and symptoms associated with oral cancers is crucial for increasing the likelihood of patient presentation for opportunistic screening and reducing delay in patient appraisal for early detection. This study aimed to assess the knowledge of oral cancer and to ascertain socio-demographic factors that influence knowledge amongst adult dental patients attending public clinics in Brisbane, Australia. A convenience sample of 213 adult dental patients who attended the Herston and Stafford public health clinics in Brisbane, Australia, between July and August 2019 participated in the self-administered questionnaire. Multivariate analyses were performed to identify predictors for oral cancer knowledge. Patients were well informed of smoking as a risk factor (n = 135; 84.4%), whereas only 53.8% (n = 82) of participants agreed that heavy alcohol consumption was a risk factor. A larger proportion of participants identified difficulty of moving the tongue (n = 79; 49.4%) and pain on swallowing (n = 72; 45.0%) compared to the proportion who identified fixed red patches (n = 61; 38.1%) and fixed white patches (n = 57; 35.6%) as a sign or symptom. Education level and gender were significant knowledge predictors for alcohol (p = 0.01), old age (p = 0.008) and family history (p = 0.004) as a risk factors for oral cancer. Those with a family history of cancer were more likely to identify a red patch (p = 0.02), bleeding gums (p = 0.001) and altered sensation (p = 0.023) as a sign or symptom of oral cancer. Overall, patient knowledge was greater for risk factors than for signs and symptoms for oral cancer. Symptoms associated with later stages of cancer were recognised by a greater proportion of patients compared to early stages of oral cancer. These results indicate the need for targeted public health initiatives to improve patient knowledge. [ABSTRACT FROM AUTHOR]

Purpose: We described the phenotype of a large 4-generation family with Hyperparathyrodism-Jaw Tumor syndrome (HPT-JT) associated with a rare deletion of exon 3 of the CDC73 gene. Methods: We collected medical, genetic data on 24 family members descended from a common ancestor carrying a heterozygous deletion of exon 3. Results: Thirteen carried the deletion, the penetrance was estimated at 50% at 40 years. Seven patients (39 ± 14.5 years) presented with HPT which could start at 13. Median plasmatic calcium and PTH levels were 3.13 ± 0.7 mmol/L and 115 ± 406 pg/ml, respectively. Kidney disease related to hypercalcemia were present in 57.1% of patients. All seven patients underwent surgery to remove a single parathyroid adenoma. One recurrence occurred 7 years post-surgery. No parathyroid carcinoma has been found to date. We found two atypical parathyroid adenomas. We described an additional somatic variant in exon 1 of gene CDC73 in two tumors. Jaw tumors were not necessarily associated with hyperparathyroidism, as shown in one case. Two kidney cysts were also reported. Variable phenotype expressivity was emphasized by clinical presentations in 2 monozygotic twins: acute hypercalcemia, kidney failure and ossifying fibroma in one twin, versus normocalcemic parathyroid adenoma in the other one. Conclusion: We report a family carrier of a deletion of exon 3 of the CDC73 gene. This is characterized by a high level of hypercalcemia, deleterious kidney effects and atypical parathyroid adenomas without carcinomas. Onset and intensity of HPT remain unpredictable. The additional somatic mutation found in the parathyroid tumor could lead to these phenotypical variations. [ABSTRACT FROM AUTHOR]

Purpose: With the advancements in technology, dental pedagogy has also evolved, and new learning technologies have emerged. Virtual reality (VR) as an education tool in dentistry is underutilised. VR as an adjunct in local anaesthesia (LA) teaching in paediatric dentistry has not been investigated. The study aimed to investigate dental student's perception of dental LA VR simulation on a paediatric patient and to determine whether this can improve students learning experience. Methods: Seventy-one students participated in a self-administered questionnaire before and after the use of dental LA VR simulator. Descriptive analysis was performed to determine the perceptions of experience gained through VR. The data were tabulated, graphed, and analysed using SPSS and GraphPad Prism software. Results: The study noted that 89.9% of participants perceived that it would improve their LA skills. After using dental LA VR, 83.1% of participants experienced more engaged in the learning activity, and 55.0% of participants agreed/strongly agreed that it improved their understanding of anatomical landmarks. Around 56.4% of participants agreed/strongly agreed that it added value compared with traditional LA teaching methods. Conclusion: It can be concluded that the use of VR simulation can enhance students engagement and learning experience in paediatric dentistry settings and can be used as an additional means of LA training. [ABSTRACT FROM AUTHOR]

d-Aspartate (d-Asp) and d-serine (d-Ser) have been proposed to promote early-phase LTP in vitro and to enhance spatial memory in vivo. Here, we investigated the behavioural effects of chronic consumption of d-Asp and d-Ser on spatial learning of mice together with the expression of NMDA receptors. We also studied the alterations of neurogenesis by morphometric analysis of bromo-deoxyuridine incorporating and doublecortin expressing cells in the hippocampus. Our results specify a time period (3–4 h post-training), within which the animals exposed to d-Asp (but not d-Ser) show a more stable memory during retrieval. The cognitive improvement is due to elimination of transient bouts of destabilization and reconsolidation of memory, rather than to enhanced acquisition. d-Asp also protracted reversal learning probably due to reduced plasticity. Expression of GluN1 and GluN2A subunits was elevated in the hippocampus of d-Asp (but not d-Ser) treated mice. d-Asp or d-Ser did not alter the proliferation of neuronal progenitor cells in the hippocampus. The observed learning-related changes evoked by d-Asp are unlikely to be due to enhanced proliferation and recruitment of new neurones. Rather, they are likely associated with an upregulation of NMDA receptors, as well as a reorganization of receptor subunit assemblies in existing hippocampal/dentate neurons. [ABSTRACT FROM AUTHOR]

Endosymbiosis and organellogenesis are virtually unknown among prokaryotes. The single presumed example is the endosymbiogenetic origin of mitochondria, which is hidden behind the event horizon of the last eukaryotic common ancestor. While eukaryotes are monophyletic, it is unlikely that during billions of years, there were no other prokaryote–prokaryote endosymbioses as symbiosis is extremely common among prokaryotes, e.g., in biofilms. Therefore, it is even more precarious to draw conclusions about potentially existing (or once existing) prokaryotic endosymbioses based on a single example. It is yet unknown if the bacterial endosymbiont was captured by a prokaryote or by a (proto-)eukaryote, and if the process of internalization was parasitic infection, slow engulfment, or phagocytosis. In this review, we accordingly explore multiple mechanisms and processes that could drive the evolution of unicellular microbial symbioses with a special attention to prokaryote–prokaryote interactions and to the mitochondrion, possibly the single prokaryotic endosymbiosis that turned out to be a major evolutionary transition. We investigate the ecology and evolutionary stability of inter-species microbial interactions based on dependence, physical proximity, cost–benefit budget, and the types of benefits, investments, and controls. We identify challenges that had to be conquered for the mitochondrial host to establish a stable eukaryotic lineage. Any assumption about the initial interaction of the mitochondrial ancestor and its contemporary host based solely on their modern relationship is rather perilous. As a result, we warn against assuming an initial mutually beneficial interaction based on modern mitochondria–host cooperation. This assumption is twice fallacious: (i) endosymbioses are known to evolve from exploitative interactions and (ii) cooperativity does not necessarily lead to stable mutualism. We point out that the lack of evidence so far on the evolution of endosymbiosis from mutual syntrophy supports the idea that mitochondria emerged from an exploitative (parasitic or phagotrophic) interaction rather than from syntrophy. [ABSTRACT FROM AUTHOR]

The epithelial Na+ channel (ENaC) is essential for Na+/K+ homeostasis and blood pressure control. Its activity is regulated by proteases in rodents. To gain more information on proteolytic ENaC regulation in humans, we tested the hypotheses that (1) human kidney α- and γ-ENaC subunits are furin-cleaved, glycosylated, and altered by medication that change plasma aldosterone; (2) prostasin-cleaved γ-ENaC is increased in proteinuria, and (3) cleaved ENaC moieties prevail at the membranes and in urinary extracellular vesicles (uEVs). We developed three monoclonal antibodies (mAbs) targeting (1) the neo-epitope generated after furin cleavage in γ-ENaC (mAb-furin); (2) the intact prostasin cleavage-site in γ-ENaC (mAb-intactRKRK), and (3) the α-ENaC subunit (mAb-alpha). Nephrectomy tissue and uEVs were used for immunoblotting and -histochemistry. In human kidney tissue, mAb-furin detected a ≈ 65–70 kDa protein, compatible with furin-cleaved γ-ENaC; mAb-intactRKRK detected full-length (≈ 90–100 kDa) and furin-cleaved (≈ 70–75 kDa) γ-ENaC. mAb-alpha detected a ≈ 50 kDa protein compatible with furin-cleaved α-subunit. Furin-cleaved γ-ENaC was detected predominantly within membrane fractions and deglycosylation shifted full-length γ-ENaC migration ~ 20 kDa. While γ-ENaC uEV levels were below the detection limit, α-ENaC migrated as intact (≈ 75 kDa) and furin-cleaved (≈ 50 kDa) in uEVs. Kidney levels of α- and γ-ENaC in diuretic- (n = 3) and ACE-inhibitor-treated (n = 4) patients were not different from controls (n = 4). Proteinuric patients (n = 6) displayed similar level of furin-cleaved γ-ENaC as controls (n = 4). Cleaved α-ENaC abundance was significantly lower in the kidneys from proteinuria patients. In conclusion, the study demonstrates ENaC cleavage as an event in human kidney that could contribute to physiological regulation and pathophysiological activation of ENaC. [ABSTRACT FROM AUTHOR]

Two-scale tests, microscale and bench scale, are conducted to analyze the flammability of a flexible polyurethane foam. Microscale tests include simultaneous thermal analysis coupled to Fourier transform infrared spectroscopy, and microscale combustion calorimeter (MCC). Evolved gas components, heat release rate per unit mass, total heat release, derived heat release capacity, and minimum ignition temperature are obtained. Bench scale tests are performed on cone calorimeter. Peak heat release rate per unit area, effective heat of combustion, minimum incident heat flux for ignition, and total heat release per unit area of different incident heat fluxes are obtained. FO-category of the PU foam is estimated by multiple discriminant function analysis based on the results of cone calorimeter test. The relationship between the two-scale tests is analyzed. The minimum ignition temperatures derived from multi heating rate MCC tests are used to predict the time to ignition and compared with the results from cone calorimeter tests. This PU foam is evaluated as a high fire hazard polymer having low heat release capacity, low ignition temperature, and short ignition time. [ABSTRACT FROM AUTHOR]

The energy stands of fast-growing tree species and crops are a prospective resource of renewable energy to the future. The paper focuses the assessment and comparison of the thermal properties of selected species of fast-growing trees (Paulownia tomentosa, Salix viminalis clone Tora, Populus × euramericana clone MAX 4) and energy crops (Sida Hermaphrodita, Arundo donax, Miscanthus × giganteus), as well as ash content (mass%). The following fire and thermal and properties were tested: spontaneous ignition temperature, gross caloric value, heating value. Besides those parameters, the elemental composition and ash content of the samples tested were analyzed. The results showed the energy crops to be much more effective for energy production than the energy trees. It is mostly due to higher yields harvested in a relatively short time, increased share of fiber, as well as higher energy efficiency. The highest heating value (energy potential) in case of energy crops showed Miscanthus × giganteus (16.29 ± 0.14 MJ kg−1), which had the lowest ash content (2.67 ± 0.08 mass% on average). The highest heating value in case of fast-growing tree species showed Paulownia (16.40 ± 0.18 MJ kg−1), which also had the lowest ash content (0.75 ± 0.05 mass% on average), while the Populus had the highest one (2.58 ± 0.24 mass% on average). [ABSTRACT FROM AUTHOR]

The plasminogen system is important for fibrinolysis in addition to tissue remodeling and inflammation with significance for kidney disease. The system consists of the circulating zymogen plasminogen (Plg) and the tissue- and urokinase-type plasminogen activators, tPA and uPA, expressed in the glomeruli, endothelium and tubular epithelium, respectively, and the inhibitors α-antiplasmin and plasminogen activator inhibitor-type1, PAI-1. Plasminogen is activated by surface receptors, some with renal expression: urokinase-type plasminogen activator receptor (uPAR), plasminogen receptor KT (Plg-R), and tPA, most evident in the endothelium. Plasmin may exert effects through protease-activated receptors, PARs, expressed in the kidney. Deletion of plasminogen system component genes confers no major developmental or renal phenotypes in normal mice. In glomerular injury and renal interstitial fibrosis, deletion of various components, notably Plg, uPA, PAI, and uPAR is associated with protection suggesting a disease promoting effect of plasmin, in some cases exerted through PAR1 receptor activation. Plasminogen and uPA are aberrantly filtrated across the glomerular barrier in proteinuria, and plasminogen is activated in the tubular fluid. In the tubular fluid, plasmin may activate proteolytically the epithelial sodium channel (ENaC) and inhibit the apical calcium transporter transient receptor potential cation channel subfamily V member 5 (TRPV5), which could explain impaired sodium excretion and enhanced calcium excretion in proteinuria. Amiloride, a potassium-sparing diuretic, inhibits urokinase and plasmin activation in the tubular fluid and uPAR expression in vitro , which highlights new indications for an old drug. Protease inhibitors lowered blood pressure and antagonized fibrosis in salt-sensitive Dahl rats. Current knowledge indicates that the plasminogen system aggravates renal disease by direct and indirect hypertensive effects and is a promising target to antagonize disease progression. [ABSTRACT FROM AUTHOR]

Preeclampsia is characterized by hypertension, proteinuria, suppression of plasma renin-angiotensin-aldosterone, and impaired urine sodium excretion. Aberrantly filtered plasmin in urine may activate proteolytically the γ-subunit of the epithelial sodium channel (ENaC) and promote Na reabsorption and urine K loss. Plasma and urine was sampled from patients with preeclampsia, healthy pregnant controls and non-pregnant women, and from patients with nephrostomy catheters. Aldosterone concentration, urine plasminogen, and protein were determined. Exosomes were isolated by ultracentrifugation. Immunoblotting was used to detect exosome markers; γ-ENaC (two different epitopes within the inhibitory peptide tract), α-ENaC, and renal outer medullary K-channel (ROMK) and compared with human kidney cortex homogenate. Urine total plasmin(ogen) was significantly increased in preeclampsia, plasma and urine aldosterone was higher in pregnancy compared to non-pregnancy, and the urine Na/K ratio was lower in preeclampsia compared to healthy pregnancy. Exosome markers ALIX and AQP-2 were stably associated with exosomes across groups. Exosomal α-ENaC-subunit migrated at 75 kDa and dominantly at 50 kDa and was significantly elevated in pregnancy. In human kidney cortex tissue and two of four pelvis catheter urine, ~90-100 kDa full-length γ-ENaC was detected while no full-length γ-ENaC but 75, 60, and 37 kDa variants dominated in voided urine exosomes. There was no difference in γ-ENaC protein abundances between healthy pregnancy and preeclampsia. ROMK was detected inconsistently in urine exosomes. Pregnancy and preeclampsia were associated with increased abundance of furin-cleaved α-ENaC subunit while γ-subunit appeared predominantly in cleaved form independently of conditions and with a significant contribution from post-renal cleavage. [ABSTRACT FROM AUTHOR]

Acetylcholine is an excitatory neurotransmitter important for oxygen sensing in mammals. A cholinergic mechanism in the fish gill has been implicated in the hyperventilatory response to acute hypoxia; however, the identity and distribution of acetylcholine-containing cells in the gills is poorly defined. We test the hypothesis that cholinergic cells are present in the gill filament epithelium in zebrafish ( Danio rerio), a model vertebrate for which oxygen chemoreceptors are well characterized, and that these cells would receive nervous innervation. Using immunohistochemistry and confocal microscopy, we observed 10.2 ± 0.6 cells immunoreactive for the vesicular acetylcholine transporter (VAChT) on the efferent aspect of each gill filament, where a high density of serotonergic oxygen-sensitive neuroepithelial cells (NECs) were located. VAChT-positive cells of the efferent epithelium were positioned within 10 μm of NECs. On the afferent aspect of the gill filaments, VAChT-positive cells were greater in number (30.8 ± 3.1 per filament). On the efferent and afferent filament aspects, VAChT-positive cells did not contain serotonin, but did express choline acetyltransferase (ChAT), the enzyme that synthesizes ACh, and were often closely apposed to nerve fibers labeled with the neuronal marker, zn-12. We conclude that cholinergic cells in the zebrafish gills were present in the primary epithelium of gill filaments, and formed contacts with nerve fibers. These studies provide morphological evidence for the presence of a cholinergic system in the zebrafish gill. Such a pathway may contribute to the reflex hyperventilatory response during hypoxia. [ABSTRACT FROM AUTHOR]

Lower brainstem projections from nucleus accumbens (Ac) subregions to the parabrachial complex (PB), the nucleus of the solitary tract and the vagal motor nuclei have been described previously in the domestic chick by our group. Such projections, particulary those from the core and rostral pole regions of Ac have not been found in mammals or pigeons. Here we report on the presence of neurotensin (NT) in the neurons projecting from different Ac subnuclei, and also from the bed nucleus of stria terminalis, to the PB in the domestic chicken. The study is based upon correlated retrograde tracing (using Fast Blue) and NT immunohistochemistry, supplemented with regional charting and quantitative analysis of double-labeled neurons. The number of retrogradely labeled cells in Ac subdivisions reflects the size of FB tracer deposit, and the degree to which it extends to the medial PB. Of all Ac subregions, the core contained the largest amount of double-labeled cells. The findings demonstrate that the anatomical pathway through which the Ac can directly modulate taste-responsive neurons of the PB employs mainly neurotensin as a neuromodulator. The observed anatomical difference between mammals and birds is either a general taxonomic feature or it reflects feeding strategies specific for the domestic chick. The results are also relevant to a better understanding of the role of NT in food intake and reward-related behaviors in birds. [ABSTRACT FROM AUTHOR]

Human adipose-derived stromal cells (hASCs) possess the potential for chondrogenic differentiation. Recent studies imply that this differentiation process may be enhanced by culturing the cells in low oxygen tension in combination with three-dimensional (3D) scaffolds. We report the evaluation of the chondrogenic potential of hASC pellets in 5 and 21 % O and as cell-scaffold constructs using a collagen I/III scaffold with chemical induction using TGF-β3. hASCs from four human donors were cultured both in a micromass pellet system and in 3D collagen I/III scaffolds in either 5 or 21 % O. Chondrogenesis was evaluated by quantitative gene expression analysis of aggrecan, SOX9, collagen I, II and X and histological evaluation with H&E and toluidine blue staining. Induced pellets cultured in 5 % O showed increased peripheral cellularity and matrix deposition compared with 21 % O. Induced pellets cultured in 5 % O had increased control-adjusted gene expression of aggrecan, SOX9 and collagen I and decreased collagen X compared with 21 % O cultures. Induced pellets had higher gene expression of aggrecan, SOX9, collagen I, II and X and increased ratios of collagen II/I and collagen II/X compared with controls. As for pellets, scaffold cultures showed cellularity and matrix deposition organized in a zonal manner as a function of the oxygen tension, with a cartilage-like morphology and matrix deposition peripherally in the 5 % O group and a more centrally located matrix in the 21 % O group. There were no differences in histology and gene expressions between pellet and scaffold cultures. Five percent O in combination with chondrogenic culture medium stimulated chondrogenic differentiation of hASCs in vitro. We observed similar patterns of differentiation and matrix disposition in pellet and scaffold cultures. [ABSTRACT FROM AUTHOR]

Chiral capillary electrophoresis method has been developed to separate aspartate and glutamate enantiomers to investigate the putative neuromodulator function of d-Asp in the central nervous system. To achieve appropriate detection sensitivity fluorescent derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and laser-induced fluorescence detection was applied. Although, simultaneous baseline separation of the two enantiomer pairs could be achieved by using 3 mM 6-monodeoxy-6-mono(3-hydroxy)propylamino-β-cyclodextrin (HPA-β-CD), further improvement of the chemical selectivity was required because of the high excess of l-enantiomers in real samples to be analyzed. The system selectivity was fine-tuned by combination of 8 mM heptakis(2,6-di- O-methyl)-β-cyclodextrin and 5 mM HPA-β-CD in order to increase the resolution between aspartate and glutamate enantiomers. The method was validated for biological application. The limits of detection for d-Asp and d-Glu were 17 and 9 nM, respectively, while the limit of quantification for both analytes was 50 nM. This is the lowest quantification limit reported so far for NBD-tagged d-Asp and d-Glu obtained by validated capillary electrophoresis laser-induced fluorescence method. The applicability of the method was demonstrated by analyzing brain samples of 1-day-old chickens. In all the studied brain areas, the d-enantiomer contributed 1-2 % of the total aspartate content, corresponding to 17-45 nmol/g wet tissue. [ABSTRACT FROM AUTHOR]

Several studies have shown that L-aspartate (Asp) is present in synaptic vesicles and released exocytotically from presynaptic terminals, possibly by Ca-dependent corelease of Asp and L-glutamate (Glu). It has been demonstrated that both excitatory amino acids (EAAs) are released from the rat striatum as part of corticostriatal neurotransmission. The single or colocalized occurrence of Asp and Glu in specific synaptic boutons of the chicken medial striatum/nucl. accumbens has been demonstrated by our group using ultrastructural immunocytochemistry. However, evidence for the presence of EAAs in any specific striatal pathway was only circumstantial. Here, we report on the distribution of Asp and Glu in specific synaptic terminals of the amygdalostriatal pathway, both in rat and chicken brains, combining anterograde tracing with postembedding immunogold labeling of Asp or Glu. Immunoreactivity for Asp and Glu was observed in amygdalofugal terminals with asymmetrical synaptic junctions (morphologically representing excitatory synapses) in both species. The postsynaptic targets were either dendritic spines or small dendrites, whereas axosomatic or axo-axonic connections were not observed. Ultrastructurally, the synaptic terminals immunoreactive for Asp were indistinguishable from those immunoreactive for Glu. The findigs are consistent with an Asp-Glu corelease mechanism, with a distinct synaptic contingent, evolutionarily conserved in the amygdalostriatal pathway. [ABSTRACT FROM AUTHOR]

Correlation algorithms are used to analyse the relationship amongst heat release rate, carbon dioxide and carbon monoxide generated in cone calorimetry test of material flammability. These correlation algorithms include Pearson's correlation, Spearman's rank correlation and Kendall's rank correlation. Cone test data of seven materials are analysed. These materials are two kinds of polyvinyl chloride wall panel, glass-reinforced plastics, vinyl panel, polymethyl methacrylate, polyurethane and two types of expanded polystyrene foam. Correlation coefficients are calculated for cone calorimeter results from tests at 50 kW m of these materials. The distribution of the coefficients would be used to discriminate the test materials according to the so-called FO-categories which can help to predict the time to flashover. [ABSTRACT FROM AUTHOR]

It has long been proposed that l-aspartate (Asp) is an excitatory neurotransmitter similar to l-glutamate (Glu) but with distinct signaling properties. The presence of Asp in excitatory synapses of the medial striatum/nucleus accumbens of domestic chicks suggests that Asp plays a role of neurotransmitter also in the avian brain. Neurotransmitters are released from the presynaptic bouton mostly by Ca dependent exocytosis. We used in vivo microdialysis to monitor the simultaneous changes of the extracellular levels of Asp and Glu in the medial striatum of young post-hatch domestic chicks. Microdialysis samples were collected from freely moving birds at 5 min intervals and analysed off-line using capillary electrophoresis. Event-related elevations of extracellular Glu and Asp concentrations in response to handling stress and to high KCl (50 mM) were observed. Increase of Glu and Asp on handling stress was 200 and 250 %, whereas on KCl stimulation the values were 300 and 1,000 %, respectively, if stress was applied before high KCl, and 150 and 200 %, respectively, in the absence of stress. In most cases, the amino acids showed correlated changes, Asp concentrations being consistently smaller at resting but exceeding Glu during stimulation. Using Ca free medium, the KCl triggered elevation of Glu was reduced. When KCl stimulation was combined with tetrodotoxin infusion, there was no significant elevation in Asp or in Glu suggesting that most of the extracellular excitatory amino acids were released by synaptic mechanisms. The results support the suggestion that Asp is co-released with Glu and may play a signaling role (as distinct from that of glutamate) in the striatum of birds. [ABSTRACT FROM AUTHOR]

Background: Anabolic androgenic steroids, such as stanozolol, are typically misused by athletes during preparation for competition. Out-of-competition testing presents a unique challenge in the current anti-doping detection system owing to logistic reasons. Analysing hair for the presence of a prohibited drug offers a feasible solution for covering the wider window in out-of-competition testing. To assist in vivo studies aiming to establish a relationship between drug levels detected in hair, urine and blood, sensitive methods for the determination of stanozolol and its major metabolite 3′-hydroxystanozolol were developed in pigmented hair, urine and serum, using brown Norway rats as a model system and liquid chromatography tandem mass spectrometry (LC-MS/MS). Results: For method development, spiked drug free rat hair, blood and urine samples were used. The newly developed method was then applied to hair, urine and serum samples from five brown Norway rats after treatment (intraperitoneal) with stanozolol for six consecutive days at 5.0 mg/kg/day. The assay for each matrix was linear within the quantification range with determination coefficient (r2) values above 0.995. The respective assay was capable of detecting 0.125 pg/mg stanozolol and 0.25 pg/mg 3′-hydroxystanozolol with 50 mg hair; 0.063 ng/mL stanozolol and 0.125 ng/mL 3′-hydroxystanozolol with 100 µL of urine or serum. The accuracy, precision and extraction recoveries of the assays were satisfactory for the detection of both compounds in all three matrices. The average concentrations of stanozolol and 3′-hydroxystanozolol, were as follows: hair = 70.18 ± 22.32 pg/mg and 13.01 ± 3.43 pg/mg; urine = 4.34 ± 6.54 ng/mL and 9.39 ± 7.42 ng/mL; serum= 7.75 ± 3.58 ng/mL and 7.16 ± 1.97 ng/mL, respectively. Conclusions: The developed methods are sensitive, specific and reproducible for the determination of stanozolol and 3′-hydroxystanozolol in rat hair, urine and serum. These methods can be used for in vivo studies further investigating stanozolol metabolism, but also could be extended for doping testing. Owing to the complementary nature of these tests, with urine and serum giving information on recent drug use and hair providing retrospective information on habitual use, it is suggested that blood or urine tests could accompany hair analysis and thus avoid false doping results. [ABSTRACT FROM AUTHOR]

We report the analysis of CPI-613, the first member of a large set of analogs of lipoic acid (lipoate) we have investigated as potential anticancer agents. CPI-613 strongly disrupts mitochondrial metabolism, with selectivity for tumor cells in culture. This mitochondrial disruption includes activation of the well-characterized, lipoate-responsive regulatory phosphorylation of the E1α pyruvate dehydrogenase (PDH) subunit. This phosphorylation inactivates flux of glycolysis-derived carbon through this enzyme complex and implicates the PDH regulatory kinases (PDKs) as a possible drug target. Supporting this hypothesis, RNAi knockdown of the PDK protein levels substantially attenuates CPI-613 cancer cell killing. In both cell culture and in vivo tumor environments, the observed strong mitochondrial metabolic disruption is expected to significantly compromise cell survival. Consistent with this prediction, CPI-613 disruption of tumor mitochondrial metabolism is followed by efficient commitment to cell death by multiple, apparently redundant pathways, including apoptosis, in all tested cancer cell lines. Further, CPI-613 shows strong antitumor activity in vivo against human non-small cell lung and pancreatic cancers in xenograft models with low side-effect toxicity. [ABSTRACT FROM AUTHOR]

The maintenance of pluripotency of human embryonic stem cells (hESCs) requires a high efficiency of self-renewal. During in vitro propagation, however, spontaneous differentiation occurs frequently, and there is also a risk of chromosomal changes. In this study, we assessed the properties of hESCs after long-term culture at ambient air and 5% oxygen growth conditions. The hESC lines were grown for up to 42 and 18 mo in normoxic and hypoxic conditions, respectively, and their proliferation; expression of Oct4, SSEA1, Nanog, and Notch1; karyotype; telomerase activity; and differentiation potential in vitro were evaluated. In contrast to cultures at 20% oxygen, where the central zones of the colonies underwent spontaneous differentiation, during exposure to 5% oxygen, the hESC colonies maintained a homogenous and flat morphology that was consistent with the presence of Oct4-positive undifferentiated phenotype. Irrespective of oxygen concentration, the undifferentiated cells expressed high levels of Nanog and Oct4 transcripts, normal karyotype, and high telomerase activity. When assayed for differentiation potential, they yielded derivatives of all three embryonic germ layers. Our data thus indicate that hypoxic exposure has the capacity to sustain enhanced long-term self-renewal of hESCs. The hESC lines described in the current paper can be obtained for research purposes from the Laboratory for Stem Cell Research, Aalborg University. [ABSTRACT FROM AUTHOR]

This study examined the influence(s) of the type of physical discipline administered and the type of child misbehavior on college student's evaluations of parent-child disciplinary situations. Participants evaluated vignettes describing a child's behavioral transgression and the subsequent parental disciplinary response. Evaluations were assessed in terms of the abusiveness, effectiveness, and appropriateness of the discipline. As predicted, evaluations varied as a function of both the type of physical discipline and the type of behavioral transgression. For example, parent-child interactions were evaluated as being more abusive when the severity of the discipline exceeded the severity of the transgression. Gender differences emerged with women evaluating mild discipline as being just as appropriate as moderate discipline while men evaluated mild discipline as being less appropriate than moderate discipline. Further, men evaluated moderate and severe discipline as being more effective than mild discipline. Results are discussed in terms of how the current research extends previous work in this area. Implications and areas for future research also are discussed. [ABSTRACT FROM AUTHOR]

Summary. Tax oncoprotein of Human T-lymphotropic virus 1 (HTLV-1) has been proposed to dysregulate the expression of a number of cellular genes, many of which play a critical role for cell proliferation. Our initial data demonstrated that the immediate-early gene butyrate response factor 1 (BRF1) was upregulated in HTLV-1-infected cells. The ensuing studies revealed that the effect of Tax was mediated through two transcription elements. The more proximal element, located in the vicinity of TATA box, accounted for the main Tax transactivating effect, and it appeared to be a novel transcription factor-binding site. It involved the CCTCCTC sequence (nt -59/-53, relative to transcription start site) and was dubbed BRF1 Tax-responsive site (BTRS). The cellular protein(s) recruited into the formation of DNA-protein complex at this binding site were not identified. The other element, located further upstream, was a consensus cAMP-responsive site (CRE) TGACGTCA, spanning positions -400 to -393. CRE-binding protein (CREB) was found to mediate the transactivating effect of Tax at this site. Our results present the first evidence that the Tax transactivator has a capability to modulate the expression of BRF1 and that this effect is mediated by CRE and a novel BTRS motifs. [ABSTRACT FROM AUTHOR]

Asymmetric membrane currents in isolated muscle fibers of the crayfish Astacus fluviatilis were studied under voltage clamp conditions with controlled composition of the external and internal medium. Besides fast asymmetric currents which are probably associated with opening of calcium channels in the surface membrane, slow asymmetric currents with a time course almost an order of magnitude slower than in fast frog muscle fibers also are present in fibers of this type. The value of the charge transported across a single "foot" in the tubulo-reticular junction was calculated. The number of feet and their arrangement in each junction were studied by transmission electron microscopy. The number of charges transported across one foot agrees with the hypothesis that slow displacement currents are linked with movement of charge particles distributed over the whole area of the sarcolemmal and tubular invaginations, and not only in the feet. [ABSTRACT FROM AUTHOR]

That the superconducting transition in underdoped high temperature superconductors is controlled by phase ordering, implies that pairing is a local phenomenon that occurs on an intermediate length scale, and typically at a temperature above T c . The discovery of local stripe order in the LSCO family of high temperature superconductors, along with the theoretical suggestion that such structures are a general feature of doped antiferromagnets lead us further to propose that in fact pairing occurs in the vicinity of an individual stripe. The transition to a superconducting state then follows at lower temperature due to Josephson coupling between stripes. In this paper we review our microscopic model of high temperature pairing on individual stripes. [ABSTRACT FROM AUTHOR]

The volume and surface densities of structural components in isolated long-sarcomere fibres of crayfish ( Astacus fluviatilis) were estimated by stereological methods. The relative volumes were as follows (in % of the fibre volume): sarcolemmal invaginations (SI) 0.74; T-system 1.1; whole sarcoplasmic reticulum (SR) 4.7; junctional SR cisternae 0.41; mitochondria 1.1; nuclei 0.57; myofibrils 81.6; peripheral basal lamina 1.1; junctional gap 0.043; lysosomes 0.029. The values for surface densities were (in μm/100 μm): peripheral sarcolemma 1.27; SI 7.21; T-system 40.2; whole SR 146.4; junctional SR cisternae 14.88; junctional area of SR cisternae 7.05; mitochondria 8.98; nuclei 0.75; myofibrils 163. The invaginated membranes (SI and T-system) made up 97.4% of the total area of surface membranes and increased the effective area of peripheral sarcolemma 39 times. Using the values of the total electrical capacity from previous investigations on Astacus fibres, the specific capacity of surface membranes was calculated as 1.08 μF/cm. [ABSTRACT FROM AUTHOR]

The effects of volume change and cytoskeleton manipulation on the Cl channels in human embryonic skeletal muscle cells were studied. Trypsination, used for production of myoballs, changes the channel properties only a little. When the external osmolarity was reduced from 300 to 270 mosmol/l, the specific Cl conductance, g, (at &-80 mV) of myoballs increased from 5.1±1.9 to 30.4±12.2 μS/cm (SD; n=6) within 15 min. Concomitantly, the kinetics of Cl currents, elicited by clamping the membrane potential from a negative to positive values, changed from activation and subsequent slow inactivation to instantaneous activation with fast inactivation. G protein activation, protein kinase action or [Ca] elevation seemed not to be involved in these effects. Similar changes were produced in the absence of a transmembrane osmotic gradient by 500 nM intracellular cytochalasin D ( g=34.3 ±10.3 μS/cm; n=6) or 12.5 μM colchicine ( g= 15.4±1.4 μS/cm; n=5). When the external osmolarity was increased to 418 mosmol/l, 1 μM cytochalasin D did not affect g. In four of six cell-attached patches the open probability of the intermediate Cl channel was increased after reduction of the bath osmolarity. In inside-out patches, the drugs increased the open probability of the channels. It is concluded that the Cl channels are under control of the cytoskeleton. [ABSTRACT FROM AUTHOR]

The regulation of Cl channels in human myoballs by G proteins was studied using whole-cell and inside-out patch recordings. After perfusion of the cell with 0.1 mM GTP[γS], the specific Cl conductance, G, at standard resting potential (−85 mV) was increased from 5.9 μS/cm to 103 μS/cm, and the kinetics upon stepping the potential to positive values was changed from an activating current with very slow inactivation to a fast inactivating current with no potential-dependent activation. These effects were not affected by the simultaneous blockade of several signal cascades involving G proteins. Addition of the protein kinase blockers PKI (25 μM), H8 (10μM), or of the phospholipase-A-blocking agent quinacrine (10 μM), had not much influence on these GTP[γS] effects. Buffering of the intracellular Ca concentration (0.1 μM) or addition of the Ca/calmodulin antagonist trifluoperazine (50 μM) was also without effect. Pre-incubation of the cells with pertussis toxin or with cholera toxin did not change G. In excised inside-out patches voltage-clamped at −85 mV, application of GTP[γS] influenced the 'intermediate' Cl channel, the Cl channel type having the highest density in these cells, by increasing the number of transitions in a half-conductance state. The probability of the channel being in one of the two conducting states rose from 0.015 to 0.67, and the kinetics of the single-channel currents was changed so that, on average, it was similar to the whole-cell current kinetics seen after application of GTP[γS]. It is concluded that a G protein is directly interacting with these channels. [ABSTRACT FROM AUTHOR]

Chloride currents in human myoballs were investigated with the tight-seal whole-cell recording method in a wide range of membrane voltages (−125 to +145 mV). Two current components having different kinetics could be distinguished. In more than 90% of the myoballs the following results were obtained. At negative potentials, the amplitude of the Cl current was small and independent of time. The amplitude of the current increased as the membrane potential was made more positive. At potentials positive to +75mV, the current increased monoexponentially with time. Inactivation occurred only during very long (>3 s) pulses. When such a test pulse was preceded by a conditioning pulse to +60 mV, the current at potentials more than +90 mV was markedly smaller than in the absence of a prepulse, and no activation was provoked by strongly pulses. Recovery from inactivation could only be measured at potentials negative to −40mV. The Cl conductance at −85mV was 5.9±3.64 μS/cm (SD; n=10). In about 5% of the myoballs a kinetically different current was visible, characterized by fast inactivation at highly positive potentials. The current amplitudes were substantially larger in such cases, the Cl conductance at −85mV being 12.2±9.02 μS/cm ( n=4). [ABSTRACT FROM AUTHOR]

The Cl channels in human myoballs were investigated with several recording techniques. Three types of channels were found and dubbed 'small', 'intermediate', and 'large', according to their different conductance. The intermediate Cl channel was observed most frequently. It was active at the resting potential immediately after seal formation in cell-attached as well as in excised patches. Its Cl selectivity was rather high ( P/ P = 9.46; P/ P where P denotes permeability) and the slope conductance at the reversal potential with [Cl/[Cl] equal to 160 mM/42 mM was 31 pS. The channel showed an open-channel substructure with two subconductance levels having equal amplitudes. It can conduct two kinetically different currents that correspond to the activating and the inactivating Cl current components described by Zachar et al. (1992). The small Cl channel had a conductance of 10 pS at the reversal potential, a P /P of 2.7, and a P/ P of 22.6. Its open probability was biggest negative to −85 mV, resulting in an inactivating whole-cell Cl current component. Because of the small channel density and conductance the contribution of this channel type to the whole-cell current seems to be small. Patches with only one small channel were never observed which suggests that this channel type occurs in clusters. A third type of channel with very large conductance (250 pS) was seen only four times. [ABSTRACT FROM AUTHOR]

The voltage-dependent K channels of the mammalian sarcolemma were studied with the patch-clamp technique in intact, enzymatically dissociated fibres from the toe muscle of the mouse. With a physiological solution (containing 2.5 mM K) in the pipette, depolarizing pulses imposed on a cell-attached membrane patch activated K channels with a conductance of about 17 pS. No channel activity was observed when the pipette solution contained 2mM tetraethylammonium (TEA), or 2 mM 4-aminopyridine (4-AP). Whole cell recordings from these very small muscle fibres showed the well-known delayed rectifier K outward current with a threshold of about -40mV. The whole-cell current was completely blocked by 2 mM TEA in the bath, suggesting that the TEA-sensitive channels in the patch were also delayed rectifier channels. The inactivation properties of the channels were studied in the cell-attached mode. Averaged single-channel traces showed at least two types of channels discernible by their inactivation time course at a test potential of 60 mV. The fast type inactivated with a time constant of about 150ms, the slow type with a time constant of about 400 ms. A little channel activity always remained during pulses lasting several minutes, indicating either the presence of a very slowly inactivating third type of K channel, or the tendency of the fast inactivating channels to re-open at constant voltage. No difference was seen in the single-channel amplitudes of the different types of K channels. The well characterized adenosine-5′-triphosphate-(ATP)-sensitive and Ca-dependent K channels, although present, were not active under the conditions used. The results suggest that in mouse skeletal muscle the delayed rectifier channels to not only carry the outward current during excitation but are also responsible for the resting K conductance. [ABSTRACT FROM AUTHOR]

An inverse correlation was found between the serum aspirin esterase activity in human subjects and the biological half-life of salicylic acid in serum and a direct relationship between the values of the elimination rate constant and the activity of this enzyme. The rate of acetylsalicylic acid breakdown may be one of the factors which influences the biological half-like of salicylates in the organism and may participate also in determining the individual response to the administered drug. [ABSTRACT FROM AUTHOR]

A 14-year-old girl was referred to our department with a 3-month history of an asymptomatic swelling in the left cervical triangle. The girl, an active ski jumper, was used to carrying her skis on the left shoulder. There was a history of many minor falls and contusions of her body. The left posterior cervical triangle was enlarged by an elastic, partially fluctuating and clearly delineated swelling with 4-6 cm in diameter. The trapezius was elevated and the overlaying skin was intact. It was clear that the mass was spreading infraclavicularly. Nevertheless, the distal boundaries of the mass were not quite clear (Fig. 1). The infraclavicular spreading was confirmed with an ultrasound examination which revealed a hypoechogenic echo-free mass of the size of 7-10 x 3.6 cm. The mass was sonocompressible, clearly outlined and there were no signs of any infiltrating growth. No internal perfusion was found by colour-coded Doppler investigation. The blood count or biochemical tests did not reveal any pathological findings. [ABSTRACT FROM AUTHOR]

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