Miracle-dz/UniFAR-FTUs huggingface dataset:
Determination of Colistin and Colistimethate Levels in Human Plasma and Urine by High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Background: Colistin is a polypeptide antibiotic from the polymyxin E group used for the treatment of infections caused by multidrug-resistant gram-negative bacteria. The main constituents, accounting for approximately 85% of this mixture, are colistin A (polymyxin E1) and colistin B (polymyxin E2). The aim of this study was to develop and validate new and fast methods of quantification of colistin A and B and its precursors [colistin methanesulfonate sodium (CMS) A and B] by ultraperformance liquid chromatography–tandem mass spectrometry in plasma and urine with short pretreatment and run times. Methods: Chromatography was performed on an Acquity UPLC-MS/MS system (WATERS) with a WATERS Acquity UPLC C18 column (4.6 × 150 mm, 3.5 &mgr;m particle size). The pretreatment of samples consists of precipitation and extraction into microcolumns plate and HLB 96-well plate 30 &mgr;m–30 mg (OASIS) with a Positive Pressure-96 (WATERS). Results: Quantification was performed using a multiple reaction monitoring of the following transitions: m/z 390.9 → 385.1 for colistin A, m/z 386.2 → 101.0 for colistin B, and m/z 602.4 → 241.1 for polymyxin B1 sulfate. In plasma and urine, calibration curves were linear from 30 to 6000 ng/mL for colistin A and from 15 to 3000 ng/mL for colistin B. With an acceptable accuracy and precision, the lower limit of quantification were set at 24.0 ng/mL and 12.0 ng/mL for colistin A and B in plasma, and at 18.0 ng/mL and 9.0 ng/mL for colistin A and B in urine. Conclusions: These LC-MS/MS methods of quantification for colistin A and B and its precursors (CMS A and B) in plasma and urine are fast, simple, specific, sensitive, accurate, precise, and reliable. Furthermore, they are linear and repeatable. These procedures were successfully applied to a pharmacokinetic study of a critically ill patient suffering from ventilator-associated pneumonia, who was treated with nebulized CMS.
Parvocellular neurons limit motion acuity in human peripheral vision

It is generally believed that the perception of moving targets is mediated by the magnocellular (M) pathway in primate vision, but evidence is emerging that the parvocellular (P) pathway may also play a role in motion perception. Human peripheral vision is susceptible to anomalous motion perception because of spatial aliasing, and in this study we used this fact to determine if the P pathway can mediate information about low- and high-velocity stimuli. Psychometric functions relating visual performance to stimulus spatial frequency were measured for the directional discrimination of drifting sinusoidal gratings presented at 40° eccentricity. Applying the sampling theorem to our results, we estimated that the Nyquist frequency of the limiting sampling array for directional discrimination is 1.7 cycles per degree. This result was compared with the Nyquist limit and spatial filtering properties of M and P ganglion cells in the human peripheral retina, calculated from histological data on their density and dendritic field size. Our results provide evidence to suggest that the reversed motion illusion in human peripheral vision is due to spatial aliasing by the P ganglion cell mosaic. We conclude that the sampling density of P ganglion cells limits veridical motion acuity in human peripheral vision, even for high-velocity targets. This provides further evidence that the P pathway is involved in processing information about motion.
Proteasome, Transporter Associated with Antigen Processing, and Class I Genes in the Nurse Shark Ginglymostoma cirratum: Evidence for a Stable Class I Region and MHC Haplotype Lineages1

Cartilaginous fish (e.g., sharks) are derived from the oldest vertebrate ancestor having an adaptive immune system, and thus are key models for examining MHC evolution. Previously, family studies in two shark species showed that classical class I (UAA) and class II genes are genetically linked. In this study, we show that proteasome genes LMP2 and LMP7, shark-specific LMP7-like, and the TAP1/2 genes are linked to class I/II. Functional LMP7 and LMP7-like genes, as well as multiple LMP2 genes or gene fragments, are found only in some sharks, suggesting that different sets of peptides might be generated depending upon inherited MHC haplotypes. Cosmid clones bearing the MHC-linked classical class I genes were isolated and shown to contain proteasome gene fragments. A non-MHC-linked LMP7 gene also was identified on another cosmid, but only two exons of this gene were detected, closely linked to a class I pseudogene (UAA-NC2); this region probably resulted from a recent duplication and translocation from the functional MHC. Tight linkage of proteasome and class I genes, in comparison with gene organizations of other vertebrates, suggests a primordial MHC organization. Another nonclassical class I gene (UAA-NC1) was detected that is linked neither to MHC nor to UAA-NC2; its high level of sequence similarity to UAA suggests that UAA-NC1 also was recently derived from UAA and translocated from MHC. These data further support the principle of a primordial class I region with few class I genes. Finally, multiple paternities in one family were demonstrated, with potential segregation distortions.
Capacity for methane oxidation in landfill cover soils measured in laboratory-scale soil microcosms

Laboratory-scale soil microcosms containing different soils were permeated with CH(inf4) for up to 6 months to investigate their capacity to develop a methanotrophic community. Methane emissions were monitored continuously until steady states were established. The porous, coarse sand soil developed the greatest methanotrophic capacity (10.4 mol of CH(inf4) (middot) m(sup-2) (middot) day(sup-1)), the greatest yet reported in the literature. Vertical profiles of O(inf2), CH(inf4), and methanotrophic potential in the soils were determined at steady state. Methane oxidation potentials were greatest where the vertical profiles of O(inf2) and CH(inf4) overlapped. A significant increase in the organic matter content of the soil, presumably derived from methanotroph biomass, occurred where CH(inf4) oxidation was greatest. Methane oxidation kinetics showed that a soil community with a low methanotrophic capacity (V(infmax) of 258 nmol (middot) g of soil(sup-1) (middot) h(sup-1)) but relatively high affinity (k(infapp) of 1.6 (mu)M) remained in N(inf2)-purged control microcosms, even after 6 months without CH(inf4). We attribute this to a facultative, possibly mixotrophic, methanotrophic microbial community. When purged with CH(inf4), a different methanotrophic community developed which had a lower affinity (k(infapp) of 31.7 (mu)M) for CH(inf4) but a greater capacity (V(infmax) of 998 nmol (middot) g of soil(sup-1) (middot) h(sup-1)) for CH(inf4) oxidation, reflecting the enrichment of an active high-capacity methanotrophic community. Compared with the unamended control soil, amendment of the coarse sand with sewage sludge enhanced CH(inf4) oxidation capacity by 26%; K(inf2)HPO(inf4) amendment had no significant effect, while amendment with NH(inf4)NO(inf3) reduced the CH(inf4) oxidation capacity by 64%. In vitro experiments suggested that NH(inf4)NO(inf3) additions (10 and 71 (mu)mol (middot) g of soil(sup-1)) inhibited CH(inf4) oxidation by a nonspecific ionic effect rather than by specific inhibition by NH(inf4)(sup+).
A Model-law Approach to Restructuring Unsustainable Sovereign Debt

Unresolved sovereign debt problems are hurting debtor nations, their citizens and their creditors, and also can pose serious systemic threats to the international financial system. The existing contractual restructuring approach is insufficient to make sovereign debt sustainable. Although a more systematic legal resolution framework is needed, a formal multilateral approach, such as a treaty, is not currently politically viable. An informal model-law approach should be legally, politically and economically feasible. This informal approach would not require multilateral acceptance. Because most sovereign debt contracts are governed by either New York or English law, it would be sufficient if one or both of those jurisdictions enacted a proposed Sovereign Debt Restructuring Model Law as their domestic law.
Neural‐tube defects are associated with low concentrations of cobalamin (vitamin B12) in amniotic fluid

While folate supplementation reduces the risk of recurrent neural‐tube defects (NTD), both folate and cobalamin deficiencies may be independent risk‐factors for neural‐tube defects. Folate‐dependence and impaired remethylation of homocysteine are implicated as mechanisms for NTD. There are few references reported for folate, cobalamin, homocysteine and methionine in the fetal compartment. This case‐controlled pilot study of amniotic fluid (AF) samples derived from 16 NTD pregnancies and 64 age‐matched controls quantitates total homocysteine (tHcy), total cysteine (tCys), folate, cobalamin (B12), and methionine. Only decreased AF B12 concentrations were found (150 pg/ml versus 540 pg/ml, P<0·02). Since cobalamin, folate and homocysteine participate in the remethylation of homocysteine, via methyl transfer from 5‐methyltetrahydrofolate to B12, to methionine, we compared ratios of these methionine synthase (EC 2.1.1.13) ‐related intermediates. The ratio of B12/folate for NTD versus controls was 48 (34–90) versus 126 (123–182), P<0·001. The ratio of methionine/(folate×tHcy) was 1·4 (1·2–2·2) versus 2·7 (2·4–3·3), P<0·001. We conclude that AF from pregnancies with NTD have lower B12 concentrations, and that ratios of product to substrate(s) of homocysteine remethylation suggest impaired methionine synthase in the fetal compartment through the early second trimester. © 1998 John Wiley & Sons, Ltd.
A novel efficient enzyme‐immobilization reaction on NH2 polymers by means of L‐ascorbic acid

A new enzyme‐immobilization reaction by means of L‐ascorbic acid (ASA) is described using NH2 polymers based on cellulose or poly(vinyl alcohol) with the example of oxidoreductase enzymes. In this way, enzyme proteins such as glucose oxidase (GOD), glutamate oxidase, lactate oxidase, urate oxidase and peroxidase can be covalently fixed with a high surface loading to ultrathin and transparent NH2‐polymer films if their surfaces are previously treated with an ASA solution, in, for example, N,N‐dimethyl acetamide, DMSO or methanol. ASA then obviously reacts like a diketo compound with amino groups of the NH2‐polymer film and enzyme protein, forming dehydroascorbic acid derivatives with neighbouring Schiff’s‐base structures. In a subsequent fragmentation reaction, the latter presumably form stable oxalic acid diamide derivatives as coupling structures between enzyme protein and NH2‐polymer film, as suggested by results from investigations of the ASA reaction with n‐butylamine. The immobilized enzymes can be stored at 4 °C in bidistilled water for at least 1 month without becoming detached from the NH2‐polymer film and without diminished enzyme activity. The apparent Km values of the immobilized enzymes are in part clearly smaller than those of the dissolved enzymes or those found in other immobilization processes such as the diazo coupling or the bifunctional glutardialdehyde reaction. For example, the Km value of the immobilized GOD with different NH2 polymers as the matrix structure is smaller by a factor of approx. 20 than that of the dissolved enzyme.
Clinical characteristics of chronic heart failure patients with an augmented peripheral chemoreflex.

AIMS The peripheral chemoreflex may be augmented in chronic heart failure and may play a role in its pathophysiology including the mediation of exercise hyperpnoea and sympathetic activation. The objective of this study was to characterize the patients with an augmented peripheral chemoreflex. METHODS AND RESULTS Peripheral chemoreflex sensitivity was assessed by measuring the ventilatory response to hypoxia using transient inhalations of pure nitrogen in 50 patients with chronic heart failure (age 58.7 +/- 12.1 (SD) years; radionuclide left ventricular ejection fraction 26.5 +/- 13.0%). The peripheral chemoreflex of 12 healthy controls with similar demographic characteristics was 0.272 +/- 0.201l. min-1. %Sao(2)-1 compared with 0.673 +/- 0.410l. min-1. %Sao(2)-1 (P < 0.0001) in the chronic heart failure patients. Using 2 standard deviations above the mean level of the controls peripheral chemoreflex sensitivity as the upper limit of normal, we defined an augmented chemoreflex as greater than 0.6751.min-1. %Sao(2)-1. Twenty of the chronic heart failure patients (40%) demonstrated such an augmented peripheral chemoreflex. Compared with patients with peripheral chemoreflex sensitivity within the normal range, they had a reduced peak oxygen consumption during cardiopulmonary exercise (15.1 +/- 4.4 vs 18.5 +/- 5.8 ml.kg-1.min-1, P = 0.02), reduced radionuclide left ventricular ejection fraction (21.8 +/- 11.8 vs 29.4 +/- 13.1%, P = 0.046) and were in a worse New York Heart Association functional class (2.8 vs 2.4, P = 0.05). The ventilatory response to exercise, as characterized by the regression slope relating minute ventilation to carbon dioxide output during exercise, was also higher (40.48 +/- 9.32 vs 34.54 +/- 7.19, P = 0.02), consistent with the role of the peripheral chemoreflex in mediating exercise hyperpnoea. There was also an increased proportion of patients with non-sustained ventricular tachycardia in the group with an augmented peripheral chemoreflex (61% vs 21%, chi-squared 7.08, P < 0.01). No difference was seen in the age, height, weight and lung function measurements of these patients compared with the normal chemoreflex group. CONCLUSION An augmented peripheral chemoreflex is a common finding in chronic heart failure patients, one associated with increasing severity and with the exercise hyperpnoea seen in the condition. That there was an excess of patients with non-sustained ventricular tachycardia in the group with an augmented peripheral chemoreflex may be related to the chemoreflex-driven sympathetic stimulation. The peripheral chemoreflex may be important in the pathophysiology of chronic heart failure, both in terms of symptoms and exercise limitation.
Serum D-arabinitol measured by automated quantitative enzymatic assay for detection and therapeutic monitoring of experimental disseminated candidiasis: correlation with tissue concentrations of Candida albicans.

In order to further understand serum D-arabinitol (DA) as a marker for the diagnosis of disseminated candidiasis and for monitoring response to antifungal therapy, we studied the serum levels of this Candida carbohydrate metabolite by rapid automated enzymatic assay in rabbits with experimental disseminated candidiasis. The enzymatic reaction steps were performed on a standard automated clinical chemistry analyser. As a correction for renal impairment, data were expressed as serum D-arabinitol/creatinine ratio (DA/Cr). Serum creatinine concentrations were determined from the same sample with the same instrument, thereby allowing rapid determination of the DA/Cr within one laboratory. The DA/Cr was determined in 321 samples from 132 rabbits. The mean serum DA/Cr in 31 normal non-infected rabbits was 1.51 +/- 0.2 microM mg-1 dl-1. Among 84 rabbits with disseminated candidiasis and pre-terminal samples, there was a direct correlation between DA/Cr and tissue concentration of Candida albicans (r = 0.80; P < 0.001). A threshold of elevated DA/Cr (> or = 3.0 microM mg-1 dl-1) was evident in rabbits with a tissue concentration of C. albicans > or = 3 x 10(4) colony forming units (CFU) g-1. Elevated DA/Cr was detected in 48 (89%) of 54 rabbits at a C. albicans tissue concentration of > or = 3 x 10(4) CFU g-1 vs. one (3%) of 30 rabbits with < 3 x 10(4) CFU g-1 (P < 0.0001). Among all 101 rabbits with disseminated candidiasis, an elevated DA/Cr was detected at any point during infection in 60 (92%) of 65 rabbits having a C. albicans tissue concentration > or = 3 x 10(4) CFU g-1 vs. 13 (36%) of 36 rabbits with < 3 x 10(4) CFU g-1 (P < 0.0001). The relationship between the tissue response to antifungal therapy and change in DA/Cr was then further analysed. Ten (91%) of 11 rabbits with a tissue-proven response to antifungal therapy (defined as > or = 10(2)-fold reduction of CFU g-1 in comparison to untreated controls) had a > 50% reduction in elevated DA/Cr levels. By comparison, 10 (83%) of 12 treated rabbits with no response to therapy had persistently elevated DA/Cr levels (P < 0.001). These findings provide an experimental basis for understanding the patterns of expression of serum DA in disseminated candidiasis and further indicate that serial DA/Cr measurements may be useful for diagnosis and therapeutic monitoring of disseminated candidiasis.
Neural and Molecular Mechanisms Involved in Controlling the Quality of Feeding Behavior: Diet Selection and Feeding Patterns

We are what we eat. There are three aspects of feeding: what, when, and how much. These aspects represent the quantity (how much) and quality (what and when) of feeding. The quantitative aspect of feeding has been studied extensively, because weight is primarily determined by the balance between caloric intake and expenditure. In contrast, less is known about the mechanisms that regulate the qualitative aspects of feeding, although they also significantly impact the control of weight and health. However, two aspects of feeding quality relevant to weight loss and weight regain are discussed in this review: macronutrient-based diet selection (what) and feeding pattern (when). This review covers the importance of these two factors in controlling weight and health, and the central mechanisms that regulate them. The relatively limited and fragmented knowledge on these topics indicates that we lack an integrated understanding of the qualitative aspects of feeding behavior. To promote better understanding of weight control, research efforts must focus more on the mechanisms that control the quality and quantity of feeding behavior. This understanding will contribute to improving dietary interventions for achieving weight control and for preventing weight regain following weight loss.
Regional variations of T2* in healthy and pathologic achilles tendon in vivo at 7 Tesla: Preliminary results

The aim of this study was to investigate T 2* in the Achilles tendon (AT), in vivo, using a three‐dimensional ultrashort time echo (3D‐UTE) sequence, to compare field strength differences (3 and 7 T) and to evaluate a regional variation of T 2* in healthy and pathologic tendon. Ten volunteers with no history of pain in the AT and five patients with chronic Achilles tendinopathy were recruited. 3D‐UTE images were measured with the following echo times, at echo time = [0.07, 0.2, 0.33, 0.46, 0.59, 0.74, 1.0, 1.5, 2.0, 4.0, 6.0, and 9.0 ms]. T 2* values in the AT were calculated by fitting the signal decay to biexponential function. Comparing volunteers between 3 and 7 T, short component T 2s* was 0.71 ± 0.17 ms and 0.34 ± 0.09 ms (P < 0.05); bulk long component T 2l* was 12.85 ± 1.87 ms and 10.28 ± 2.28 ms (P < 0.05). In patients at 7 T, bulk T 2s* was 0.53 ± 0.17 ms (P = 0.045, compared to volunteers), T 2l* was 11.49 ± 4.28 ms (P = 0.99, compared to volunteers). The results of this study suggest that the regional variability of AT can be quantified by T 2* in in vivo conditions. Advanced quantitative imaging of the human AT using a 3D‐UTE sequence may provide additional information to standard clinical imaging. Finally, as the preliminary patient data suggest, T 2s* may be a promising marker for the diagnosis of pathological changes in the AT. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
ABO‐Compatible Retransplantation After ABO‐Incompatible Infant Heart Transplantation: Absence of Donor Specific Isohemagglutinins

Implementation of ABO‐incompatible (ABOi) pediatric heart transplantation has contributed to significant reduction in the mortality of infants on the waiting list, without increasing the risk of rejection. This has been attributed to the immature and therefore not fully competent immune system in this population group, which results in lower production of isohemagglutinins compared to older children and adults. Serial evaluations of isohemagglutinin titers in infants revealed cases with absence of donor specific anti‐blood group antibodies. However, it is currently unknown whether continuous exposure to donor antigens is necessary to prevent formation of donor specific isohemagglutinins (DSI) in recipients. We are reporting a case of an infant who underwent ABOi heart transplantation, with no evidence of DSI even 4 years after ABO‐compatible retransplantation. Hence, temporary exposure to donor antigens in infants may contribute to permanent absence of donor specific anti‐blood group antibodies, suggesting the possibility of induced permanent B cell tolerance.
Resolving inconsistent ratings and reviews on commercial webs based on support vector machines

Nowadays, there are more and more ratings and reviews for products and services given by customers on the commercial webs. The ratings and reviews often play critical roles as many consumers read them before making purchase decisions. Due to various reasons, the same customer sometimes gave inconsistent rating and review on commercial website. The existing studies tend to focus on the consumers' feedback on either rating or review separately, but ignore the inconsistency between them. Occasionally, consumers cannot fully express their real complex opinions simply by ratings. Consequently, they are inclined to write their true feelings in reviews. This paper harvests 852,071 ratings and corresponding reviews from the Taobao website, and resolves inconsistant ones based on text sentiment analysis and support vector machines. Our method improves the existing online customers' feedback system by intelligently resolving inconsistent, sometimes conflicting, ratings or reviews from customers, and also provides decision supports for both consumers and shopkeepers.