Using diffusion MRI data acquired with ultra-high gradient strength to improve tractography in routine-quality data.

The development of scanners with ultra-high gradient strength, spearheaded by the Human Connectome Project, has led to dramatic improvements in the spatial, angular, and diffusion resolution that is feasible for in vivo diffusion MRI acquisitions. The improved quality of the data can be exploited to achieve higher accuracy in the inference of both microstructural and macrostructural anatomy. However, such high-quality data can only be acquired on a handful of Connectom MRI scanners worldwide, while remaining prohibitive in clinical settings because of the constraints imposed by hardware and scanning time. In this study, we first update the classical protocols for tractography-based, manual annotation of major white-matter pathways, to adapt them to the much greater volume and variability of the streamlines that can be produced from today's state-of-the-art diffusion MRI data. We then use these protocols to annotate 42 major pathways manually in data from a Connectom scanner. Finally, we show that, when we use these manually annotated pathways as training data for global probabilistic tractography with anatomical neighborhood priors, we can perform highly accurate, automated reconstruction of the same pathways in much lower-quality, more widely available diffusion MRI data. The outcomes of this work include both a new, comprehensive atlas of WM pathways from Connectom data, and an updated version of our tractography toolbox, TRActs Constrained by UnderLying Anatomy (TRACULA), which is trained on data from this atlas. Both the atlas and TRACULA are distributed publicly as part of FreeSurfer. We present the first comprehensive comparison of TRACULA to the more conventional, multi-region-of-interest approach to automated tractography, and the first demonstration of training TRACULA on high-quality, Connectom data to benefit studies that use more modest acquisition protocols.

Outbreak of Salmonella enteritidis PT14b gastroenteritis at a restaurant in England: the use of molecular typing to achieve a successful prosecution.

OBJECTIVES: To describe an outbreak of Salmonella enteritidis phage type (PT) 14b in people who had eaten at a restaurant, and the investigation and subsequent prosecution of the food business operator (FBO). STUDY DESIGN: The local health protection team and environmental health department formed an outbreak control team to investigate the outbreak. METHODS: Epidemiological, microbiological, and environmental investigations were undertaken. Epidemiological investigations involved case finding and interviews. Microbiological investigation: stool samples from the suspected cases and environmental samples from the implicated food business were investigated. Salmonella isolates obtained were subjected to multiple locus variable-number tandem repeat analysis (MLVA) profiling and whole genome sequencing. In addition, adenosine triphosphate (ATP) hygiene swab tests were used to verify the quality of cleaning procedures and data loggers were used to determine the water temperature of the mechanical dishwasher. RESULTS: Fifteen cases of illness where the causative agent was shown to be S. enteritidis PT14b were identified, all of whom had eaten at the same restaurant. S. enteritidis PT14b was also identified from three of the 11 food and environmental samples taken at the restaurant and found to have the same MLVA profile as the cases. A case for prosecution was built and the FBO was successfully prosecuted in July 2015. CONCLUSIONS: This investigation highlighted that the use of molecular typing as part of thorough epidemiological, microbiological, and environmental investigations can present a robust case for prosecution against restaurants which pose a risk to public health.

X-ray diffraction analysis of the inhibition of porcine pancreatic elastase by a peptidyl trifluoromethylketone.

X-ray crystallographic data to 2.57 A resolution (1 A = 0.1 nm) have been measured for the complex of a peptidyl trifluoromethylketone inhibitor with porcine pancreatic elastase (PPE); R = 0.14. The inhibitor forms a stable complex with the enzyme by means of a covalent attachment to active site Ser195O gamma, resulting in a hemiketal moiety with tetrahedral geometry. The tripeptide protion binds as an antiparallel beta-sheet, with four hydrogen bonds augmenting the active-site covalent linkage, Ki = 9.5 microM. His57 exhibits a bifurcated H-bond to both Ser195O gamma and an F atom of the inhibitor. This study is one of a series which explores the binding geometry of a variety of small substrates and inhibitors to PPE. This peptidyl-PPE complex affords insight into the binding geometry of a novel trifluoromethylketone moiety to a serine proteinase.

Design, synthesis, and biological activity of a potent inhibitor of the neuropeptidase N-acetylated alpha-linked acidic dipeptidase.

A series of substituted phosphonate derivatives were designed and synthesized in order to study the ability of these compounds to inhibit the neuropeptidase N-acetylated alpha-linked acidic dipeptidase (NAALADase). The molecules were shown to act as inhibitors of the enzyme, with the most potent (compound 3) having a Ki of 0.275 nM. The potency of this compound is more than 1000 times greater than that of previously reported inhibitors of the enzyme. NAALADase is responsible for the catabolism of the abundant neuropeptide N-acetyl-aspartylglutamate (NAAG) into N-acetylaspartate and glutamate. NAAG has been proposed to be a neurotransmitter at a subpopulation of glutamate receptors; alternatively, NAAG has been suggested to act as a storage form of synaptic glutamate. As a result, inhibition of NAALADase may show utility as a therapeutic intervention in diseases in which altered levels of glutamate are thought to be involved.

Discovery and biological activity of orally active peptidyl trifluoromethyl ketone inhibitors of human neutrophil elastase.

Previously we had shown that tripeptidyl trifluoromethyl ketones (TFMKs) possessing an N-terminal diarylacylsulfonamide, such as ICI 200,880 and ICI 200,355, displayed unparalleled protection against the lung damage induced by human neutrophil elastase (HNE) when the inhibitors were administered intratracheally. Since the diarylacylsulfonamides were designed specifically to afford a long residence time in the lung, it was not unexpected that inhibitors from this class of TFMKs were not active when administered orally. Upon evaluating a large number of peptidyl TFMKs possessing a variety of N-terminal groups, several compounds were identified which demonstrated oral activity. Compounds were evaluated for their oral activity by measuring their ability to inhibit the increase in lung weight relative to body weight (Lw/Bw), the increase in red blood cells, and the increase in white blood cells induced by intratracheally administered HNE (100 micrograms/hamster). A number of tripeptidyl trifluoromethyl ketones containing neutral N-terminal groups displayed good oral activity, while those containing basic, acidic, or polar groups did not. Compound 50, possessing an N-terminal 4-(CH3O)C6H4CO group, was particularly effective, reducing Lw/Bw by 77%, red cells by 89%, and white cells by 91% when dosed at 37.5 mg/kg orally. Thus, by modifying the N-terminal group of tripeptidyl TFMKs, inhibitors can be designed which are effective in vivo when administered either orally or intratracheally.

N-aryl-3,3,3-trifluoro-2-hydroxy-2-methylpropanamides: KATP potassium channel openers. Modifications on the western region.

A subset of antiandrogen compounds, the N-aryl-3,3,3-trifluoro-2-hydroxy-2-methylpropanamides 1, were found to activate ATP sensitive potassium channels (KATP) and represent a new class of potassium channel openers (PCOs). A structure-activity relationship was carried out on the western region of this series with the goal of obtaining an activator of the ATP sensitive potassium channel suitable for use in the treatment of urge urinary incontinence. In particular three large 4-(N-aryl) substituents, the (N-phenyl-N-methylamino)sulfonyl, benzoyl, and 4-pyridylsulfonyl moieties, yielded non-antiandrogen, KATP potassium channel openers (39, 41, and 64, respectively) that are bladder selective in an in vivo rat model that simultaneously measures bladder contractions, heart rate, and blood pressure. Substitutions of the aryl rings of 41 and 64 gave several derivatives that also display selectivity in the in vivo rat model; however, none appear to offer a substantial advantage over 41 and 64. The PCO activity of 41 and 64 resides in the (S)-(-) enantiomers. ZD6169, 41(S), has been selected into development for the treatment of urge urinary incontinence.

Urine sulfated and nonsulfated bile acids as a diagnostic test for liver disease in cats.

Urine bile acid (UBA) tests reflecting "average" serum bile acid (SBA) concentrations may have greater practical utility than paired SBA samples in cats. This study evaluated whether urine sulfated bile acids (USBAs), urine nousulfated bile acids (UNSBAs), or a combined approach had a clinical utility equivalent to SBAs. Routine serum biochemistry tests, SBA concentrations, and urine samples were collected from 54 cats with hepatobiliary disease, 17 cats with nonhepatic disorders, and 8 healthy cats. UBAs were measured by a quantitative enzymatic colorimetric method, and results were normalized with urine creatinine (UCr) concentrations. Significantly higher values occurred in cats with liver disease than in cats without liver disease for USBA : UCr, UNSBA:UCr, and (USBA and UNSBA) : UCr, P < .05 each. UBA tests with diagnostic performance (sensitivity [SS], specificity [SP], and positive and negative predictive values [PV+ and PV-]) equivalent to SBAs were the UNSBA : UCr and the combined test (SS: 87, 87 versus 85; SP: 88, 88 versus 88; PV+: 96, 96 versus 96; PV-: 68, 65 versus 68; UNSBA : UCr, [USBA, and UNSBA]: UCr versus SBA, respectively). Clinical applications of the UNSBA : UCr or the combined (USBA and UNSBA) : UCr test should be useful as convenient diagnostic tests for identifying cats with liver disease and high SEA concentrations.

The Andover Working Group--accelerating the implementation of standards.

The Andover Working Group was formed with the objective to accelerate and broadly deliver standards-based solutions for healthcare which feature plug and play interoperability across the continuum of care. In this paper, organization and processes used by the Andover Working Group are discussed. A description of how multilateral message profiles, combined with object-oriented component middleware supporting application developments, systems integration and systems operation remove many of the barriers to deployment of systems of standards based applications is also given.

Rational suicide among patients who are terminally ill.

Patients' end-of-life decisions challenge nurses. Often, aggressive, life prolonging strategies create ethical dilemmas for nurses when patients decide to stop treatment. In Oregon, assisted suicide is legal and will have a profound effect on nursing practice. When a patient considers suicide, nurses need to examine the patient's mental health, symptom management, and rational decision-making ability. Evaluation of suicide risk is a priority. Nurses need to recognize that medical land psychological symptoms often trigger thoughts of suicide, but prompt treatment of pain and symptoms also reduces suicide risk. Ethical issues and guidelines for management of patients considering suicide and evaluation of rationality are presented.

Mechanism of inactivation of human leukocyte elastase by a chloromethyl ketone: kinetic and solvent isotope effect studies.

The mechanism of inactivation of human leukocyte elastase (HLE) by the chloromethyl ketone MeOSuc-Ala-Ala-Pro-Val-CH2Cl was investigated. The dependence of the first-order rate constant for inactivation on concentration of chloromethyl ketone is hyperbolic and suggests formation of a reversible "Michaelis complex" prior to covalent interaction between the enzyme and inhibitor. However, the observed Ki value is 10 microM, at least 10-fold lower than dissociation constants for complexes formed from interaction of HLE with structurally related substrates or reversible inhibitors, and suggests that Ki is a complex kinetic constant, reflecting the formation and accumulation of both the Michaelis complex and a second complex. It is proposed that this second complex is a hemiketal formed from attack of the active site serine on the carbonyl carbon of the inhibitor. The accumulation of this intermediate may be a general feature of reactions of serine proteases and chloromethyl ketones derived from specific peptides and accounts for the very low Ki values observed for these reactions. The solvent deuterium isotope effect (SIE) on the inactivation step (ki) is 1.58 +/- 0.07 and is consistent with rate-limiting, general-catalyzed attack of the active site His on the methylene carbon of the inhibitor with displacement of chloride anion. The general catalyst is thought to be the active site Asp. In contrast, the SIE on the second-order rate constant for HLE inactivation, ki/Ki, is inverse and equals 0.64 +/- 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA probe confirmatory test for Neisseria gonorrhoeae.

A DNA probe test for the culture confirmation of Neisseria gonorrhoeae in clinical isolates was evaluated with 156 isolates of N. gonorrhoeae and 120 isolates of nongonococcal Neisseria species, organisms representative of other genera within the family Neisseriaceae, and organisms isolated on media selective for N. gonorrhoeae. The 30-min test used a chemiluminescent DNA probe that was homologous to rRNA sequences of N. gonorrhoeae. We report here a specificity and a sensitivity of 100% with the 276 clinical isolates tested, including 43 gonococcal strains that had been misidentified by other methods.

Development of sensitive immunoassays to detect amylin and amylin-like peptides in unextracted plasma.

Amylin is a 37-amino-acid polypeptide synthesized in and secreted from pancreatic beta cells along with insulin. Its biological actions include the slowing and reduction of postmeal increases in plasma glucose concentrations. Studies of the basic amylin biology in humans have been hampered by the lack of a rapid, sensitive assay capable of measuring physiological concentrations of amylin in small volumes of plasma. We report here two sandwich-type immunoassays that use pairs of monoclonal antibodies, the fluorescent substrate 4-methylumbelliferyl phosphate, and the enzyme alkaline phosphatase. The minimum detectable concentration of amylin in 50 microL of plasma was 0.5 to 2 pmol/L, and the dynamic range was 2 to 100 pmol/L. The assays had average intraassay CVs of <10%, average interassay CVs of <15%, and good linearity on dilution and recovery of added amylin. The two assays use the same detection antibody, which binds to the carboxyl terminus of the molecule, but different capture antibodies. One of the assays measures only human amylin; the other also detects amylin-like peptides. Examples of measurements in human plasma are provided in subjects with impaired glucose tolerance and in nondiabetic controls.

Mechanism for slow-binding inhibition of human leukocyte elastase by valine-derived benzoxazinones.

Valine-derived benzoxazinones have been synthesized and found to be competitive, slow-binding inhibitors of human leukocyte elastase (HLE). Steady-state inhibition constants Ki are dependent on aryl substitution and reach a maximum of potency of 0.5 nM with the 5-Cl compound 6. UV-spectral data for the interaction of HLE and the unsubstituted inhibitor 3 indicate that the stable complex formed between enzyme and inhibitor is an acyl-enzyme that can either undergo ring closure, to reform intact benzoxazinone, or hydrolysis, to liberate an N-acylanthranilic acid. "Burst" kinetic data, derived from the direct observation of the interaction of HLE and 3, are consistent with results of the inhibition of catalysis experiments.

Restructuring support staff classification levels for academic health sciences library positions.

Nonprofessional library support staff traditionally hold what are considered to be low-paying, nonchallenging positions. These negative factors make retaining creative and productive employees difficult. This article outlines the approach taken at the Medical College of Georgia's Robert B. Greenblatt, M.D. Library to devise a structure of library staff positions that becomes progressively more demanding. A new nine-level Library Staff Classification Plan resulted. This plan also enables and encourages employees to acquire more skills and to accept more responsibility in order to qualify for higher-level library positions or to advance their present position to receive comparable rewards. The plan expresses the level of responsibilities expected, the employee qualifications desired, and lists representative duties across the spectrum of typical library tasks.

K-channel opening activity of dihydropyridine ZM244085: effect on 86Rb efflux and 3H-P1075 binding in urinary bladder smooth muscle.

Zeneca ZM244085, 9-(3 cyanophenyl)hexahydro-1,8 acridinedione, is a novel dihydropyridine (DHP) which relaxes KCl precontracted urinary bladder smooth muscle in vitro. The effect of ZM244085 on low and high KCl induced contractions, 86Rb efflux and [3H]-P1075 binding in guinea pig bladder strips was investigated to characterize the K-channel opening properties of this compound. Since ZM244085 is a dihydropyridine its effect on DHP binding sites on Ca2+ channels was also investigated. ZM244085 was found to be more potent in relaxing detrusor strips precontracted with 15 mM KCl than strips precontracted with 80 mM KCl (Li et al., 1995). This functional profile of ZM244085 is similar to that exhibited by typical K-channel openers (PCO). In addition, inhibition of ZM244085 induced relaxation of detrusor strips by glibenclamide suggests that ZM244085 opens ATP sensitive K-channel (KATP) in urinary bladder (Li et al., 1995). Since the glibenclamide sensitive smooth muscle relaxation activity of ZM244085 could still be an indirect effect of this compound on KATP channels we carried out 86Rb efflux studies and [3H]-P1075 binding studies to further confirm these findings. The 86Rb efflux assay is a direct method for monitoring the movement of K+ ions across the cell membranes. Displacement of [3H]-P1075 binding to bladder membranes supports a direct action of the compound on the KATP channel. The present study demonstrates that ZM244085 in a concentration dependent manner increases the rate of 86Rb efflux from guinea pig bladder strips. This effect was inhibited by glibenclamide (30 microM), a known KATP channel blocker. In addition, interaction of ZM244085 with KATP channels was also confirmed in human bladder smooth muscle cells using a 42K efflux assay. Furthermore, we were able to demonstrate that ZM244085, structurally distinct PCO, inhibited the binding of 3H-P1075 to urinary bladder strips in a manner similar to other KATP openers such as cromakalim and pinacidil. Inhibition of 3H-P1075 binding by ZM244085 and other PCO's correlates well with increases in 86Rb efflux and bladder muscle relaxation studies. Finally, ZM244085 did not exhibit any significant affect on VSCC as evidenced by very weak inhibition of [3H]-PN200,110 binding to bladder membranes by ZM244085. It is concluded that Zeneca ZM244085 is a PCO which activates KATP channels in urinary bladder.

Calcium dependent K-channels in guinea pig and human urinary bladder.

This study provides evidence for the presence of large conductance Ca(2+)-dependent K-channels in guinea pig and human urinary bladder smooth muscle. A23187, a Ca(2+)-ionophore, increased charybdotoxin and iberiatoxin sensitive 42K efflux in human urinary bladder smooth muscle cells, suggesting that large conductance Ca(2+)-dependent K-channels are present in these cells. NS004, a large conductance Ca(2+)-dependent K-channel opener, relaxed guinea pig bladder strips precontracted with 15 mM KCl which is inhibited by iberiatoxin. In addition, NS004 also evoked an iberiatoxin sensitive increase in 86Rb/42K efflux in guinea pig and human urinary bladder smooth muscle cells, demonstrating that NS004 activates large conductance Ca(2+)-dependent K-channels to achieve its relaxation effect in the bladder.

Studies of the K(ATP) channel opening activity of the new dihydropyridine compound 9-(3-cyanophenyl)-3,4,6,7,9,10-hexahydro-1,8-(2H,5H)-acridined ione in bladder detrusor in vitro.

The potassium (K+) channel opening activity of ZM244085 (9-(3-cyanophenyl)-3,4,6,7,9,10-hexahydro-1,8-(2H,5H)-acridined ione, CAS 149398-59-4), a novel dihydropyridine (DHP), was ascertained. In a set of functional assays, its mechanoinhibitory effect on myogenic activity of guinea pig bladder detrusor muscles, either mildly or highly depolarized with 15 or 80 mmol/l KCl, was measured. ZM244085 had negligible effect on the tone of the detrusor contracted with 80 mmol/l KCl but reduced the myogenic activity induced with 15 mmol/l KCl (IC50=4.2 +/- 0.4 mumol/l). Glibenclamide, an ATP-sensitive K+ (KATP) channel blocker, competitively antagonized this action of ZM244085 with a pA2 value of 7.6. This functional profile of ZM244085 is similar to that of the prototypic K+ channel opener cromakalim but stands in contrast to that of typical DHP Ca2+ channel blockers such as nifedipine and nimodipine. The membrane potential of the guinea pig detrusor, recorded with intracellular microelectrodes, was hyperpolarized 6.8 +/- 3.1 mV by ZM244085 (10 mumol/l). This hyperpolarization was completely blocked by glibenclamide but not affected by apamin (10 mumol/l), a toxin blocking specifically small conductance and Ca2+ dependent K+ (SKCa) channels. ZM244085 (10 mumol/l) increased the whole cell KATP current in isolated guinea pig detrusor cells by 8.8 +/- 2.5 pA, but failed to activate large conductance and Ca2+ dependent K+ (BKCa) channels in excised inside-out membrane patches from those cells. The results from these studies showed that ZM244085 is a K+ channel opener which activates predominantly KATP channels in vitro to relax bladder detrusors.

Mechanism of slow-binding inhibition of human leukocyte elastase by trifluoromethyl ketones.

Kinetics of inhibition have been determined for the interaction of human leukocyte elastase (HLE) with two series of peptide trifluoromethyl ketones (TFMKs): X-Val-CF3,X-Pro-Val-CF3,X-Val-Pro-Val-CF3, and X-Lys(Z)-Val-Pro-Val-CF3, where X is MeOSuc or Z. These compounds are "slow-binding" inhibitors of HLE and, thus, allow the determination of Ki, the dissociation constant for the stable complex of inhibitor and enzyme, as well as kon and koff, the rate constants for formation and decomposition of this complex. Maximal potency is reached with Z-Lys(Z)-Val-Pro-Val-CF3, which displays a Ki less than 0.1 nM. Upon binding to HLE, these compounds undergo addition by the hydroxyl of the active site serine to form a hemiketal. The evidence supporting a hemiketal intermediate includes Ki values of 1.6 and 80,000 nM for Z-Val-Pro-Val-CF3 and its alcohol analogue, linear free energy correlations between inhibitory potency and catalytic efficiency for structurally related TFMKs and substrates, and the pH dependence of kon for the inhibition of HLE by Z-Val-Pro-Val-CF3, which is sigmoidal and displays a pKa of 6.9. Hemiketal formation is probably not rate limiting, however. Kinetic solvent isotope effects of unity suggest that kon cannot be rate limited by a reaction step, like hemiketal formation, that is subject to protolytic catalysis. A general mechanism that is consistent with these results is one in which formation of the hemiketal is rapid and is followed or preceded by a slow step that rate limits kon.(ABSTRACT TRUNCATED AT 250 WORDS)