bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is detrusor instability in elderly males related to the grade of obstruction?
Authors: Rosier P. F. W. M. , de la Rosette J. J. M. C. H. , Wijkstra H. , Van Kerrebroeck Ph. E. V. , Debruyne F. M. J. 
Published: March 2007

AbstractAnalysis of 185 consecutive patients with BPH revealed concomitant detrusor instability in 20% of the patients. Of all patients 30.9% were not obstructed, 51.8% were moderately obstructed and 17.3% were severely obstructed. Patients with detrusor instability during filling cystometry revealed no differences in average age, prostate volume or symptoms. Mean filling cystometry parameters revealed earlier sense of urge correlating with higher pressures at lower volumes in patients with detrusor instability. Pressure‐flow analysis showed no differences between the patients with and without detrusor instability in bladder outflow obstruction parameters. Further analysis, however, revealed that the prevalence of patients with detrusor instability reaches a “steady state” at a moderate level of obstruction. On clinical epidemiological grounds, the conclusion is made that detrusor instability is developing in the early phase of obstruction. Probably detrusor instability and bladder outflow obstruction are concomitant, due to the aging process in many of these patients. © 1995 Wiley‐Liss, Inc.
Urodynamic and other effects of tolterodine: A novel antimuscarinic drug for the treatment of detrusor overactivity
Authors: Stahl M. M. S. , Ekström B. , Sparf B. , Mattiasson A. , Andersson K.‐E. 
Published: March 2007

AbstractTolterodine, a novel compound intended for treatment of urgency and urge incontinence, has been characterized as a potent muscarinic receptor antagonist in pharmacological in vitro and in vivo studies. In cats, tolerodine was shown to reduce bladder pressure at doses significantly lower than those affecting salivation. To predict clinical effectiveness, an open pilot study was performed in healthy male volunteers. Efficacy was measured by cystometry and by spontaneously reported effects after administration of a single oral dose of tolterodine. 6.4 mg, given as a water solution. Tolterodine had distinct inhibitory effects on urinary bladder function, both at 1 and 5 hours post‐dose. At 1 hour, but not at 5 hours post‐dose tolterodine also significantly reduced stimulated salivation. In addition to the objectively demonstrated changes in urodynamic parameters, most volunteers experienced voiding difficulties. No significant changes in blood pressure, heart rate, or near point of accommodation were registered. Tolterodine, in the dosage used, was both objectively and subjectively shown to exert a marked inhibitory effect on micturition in healthy subjects, and the data suggest a more pronounced effect on bladder function than on salivation. © 1995 Wiley‐Liss, Inc.
Irritable bladder syndrome in an animal model: A continuous monitoring study
Authors: Ghoniem Gamal M. , Shaaban Alaa M. , Clarke Margaret R. 
Published: March 2007

AbstractIrritable bladder syndrome (IBS) was induced in four female African green monkeys (Cercopithecus aethiops) by the use of intravesical instillation of acetone. The animals were housed in a modified metabolic cage for continuous micturition monitoring, and two uroflowmeters connected to a remote PC monitored the frequency, voided volumes, and peak flows. Before and after, urea absorption studies and urodynamics were obtained for each animal. Urea absorption increased significantly after acetone instillation and returned to baseline after 4 weeks (26 to 66 to 32%). Intravesical acetone instillation produced marked effects on bladder physiology in the first week. Bladder compliance dropped from a baseline of 10.47 to 0.58 ml/cm H2O. The voiding pattern changed from a normal pattern with a mean voided volume of 17.58 ml into marked increase in frequency and dribbling pattern with few voids (mean = 5.03 ml). Systematic behavioral observations were carried out for 4 hours per day utilizing an observation program on a laptop computer. Activity patterns, attention, sterotypic behaviors, and self‐directed activities were recorded for each monkey. The animals demonstrated decreased frequency of activity and increased frequency in self‐directed activities (groom, scratch), behaviors consistent with an animal experiencing pain or discomfort. The findings suggested that IBS induction in monkeys is feasible and produces a clinical picture similar to interstitial cystitis in humans. It offers a suitable animal model to enhance the understanding of voiding dysfunction with its neural pathways and to test the different therapeutic modalities to control IBS. © 1995 Wiley‐Liss, Inc.
A critical assessment of methods of measuring metabolite concentrations by NMR spectroscopy
Authors: Tofts Paul S. , Wray Susan 
Published: March 2007

AbstractMany NMR studies are made by scientists and clinicians in order to measure metabolite levels. There is a growing need to obtain absolute quantification of these metabolites. We have therefore reviewed the methods that are available and those which are being developed, for studies in vivo and on isolated tissues. We describe the following methods and assess their advantages and limitations: (1) Conventional spectroscopy and area ratios, (2) Tissue extracts, (3) External capillary, (4) Internal endogenous marker, (5) Internal exogenous marker, (6) External marker in bath, (7) Reference to internal 1H water concentration, (8) Gradient‐localized spectroscopy and (9) Fourier series analysis localization. The relevant biological and technical aspects associated with quantification of metabolite concentrations are also discussed. This includes NMR visibility, origin of the NMR signals, definitions of concentration, influence of the RF coil, data collection and data analysis.
Alterations in relative phosphocreatine concentrations in preclinical mouse muscular dystrophy revealed by in vivo nmr
Authors: Heerschap A. , Bergman A. H. , Van Vaals J. J. , Wirtz P. , Th. Loermans H. M. , Veerkamp J. H. 
Published: March 2007

AbstractUsing in vivo 31P NMR spectroscopy, the early postnatal development of lower hindleg muscles of normal and dystrophic mice was investigated. Ratios of phosphocreatine and inorganic phosphate, and of phosphocreatine and ATP increased exponentially during normal postnatal growth and differentiation. In dystrophic skeletal muscles, however, the ratios were already considerably lower during the early postnatal period, before histopathological features were observed. The ratios remained lower, relative to normal muscles, at least into the young adult stage. A deficiency in the sequestering of creatine or a defect in the phosphocreatine shuttle is proposed to explain the pathological features observed in this disorder.
Phosphate metabolites in rat skin
Authors: Stubbs Marion , Vanstapel Florent , Rodrigues Loreta M. , Griffiths John R. 
Published: March 2007

AbstractA model for studying the 31P NMR spectrum of rat skin without contribution from other tissue signals has been developed by creating a skin pedicle. 31P NMR spectra were obtained with a solenoidal coil, which was separated from the flank of the rat by a Faraday shield. Phosphomonoesters, inorganic phosphate (Pi) (1.63 ± 0.12 m̈mol per g wet wt), phosphodiesters, phosphocreatine (PCr) (1.4 ± 0.12 m̈mol per g wet wt) and ATP (1.35 ± 0.22 m̈mol per g wet wt) were observed, superimposed on broader signals, probably due to phospholipids. Extracts of freeze‐clamped pedicles contained concentrations of phosphorus metabolites similar to those seen by NMR. The exception was Pi which was twofold higher in the extract. The presence of the broader phospholipid contribution suggests that the signals did not arise solely from the panniculus carnosus muscle of rat skin, although this muscle was evident on histological examination of the pedicles. In extracts of normal rat skin levels of creatine, ATP, ADP and Pi were similar to those of pedicles, whereas PCr was about twofold higher. Signals from rat skin are likely to contribute to spectra of subcutaneous organs and tumours. Two kinds of rat hepatoma that contained no PCr frequently gave PCr signals from the overlying skin, whereas in three other subcutaneous tumours the contribution from skin was negligible.
Four‐dimensional phosphorus‐31 chemical shift imaging of carcinoid metastases in the liver
Authors: Jane Cox I. , Sargentoni Janet , Calam John , Bryant David J. , Iles Richard A. 
Published: March 2007

AbstractFour‐dimensional chemical shift imaging was used to map spatial variations in phosphorus metabolites in a patient with carcinoid metastases in the liver. The results were compared to those from an age and sex matched volunteer, with no known previous history of liver disease. In the patient local abnormalities were observed. These included elevated phosphomonoester and decreased phosphodiester concentrations relative to adenosine triphosphate. The regions of abnormality corresponded to regions containing metastases identified with x‐ray computed tomography and magnetic resonance imaging.
Passive electrical isolation of double coil probes for localized spectroscopy and imaging
Authors: Styles Peter 
Published: March 2007

AbstractA circuit is described for the electrical isolation of double coil probes where separate transmitter and receiver coils are both tuned to the same frequency and are coupled by mutual inductance. There are only passive components in the probe, and so no additional control signals are required for switching between transmit and receive conditions. An analysis of the operation of the circuit is included together with details of component selection and setting‐up procedures, thus facilitating the implementation of the design for a variety of applications in both imaging and spectroscopy.
A 31p nuclear magnetic resonance study in vivo of metabolic abnormalities in rats with acute liver failure
Authors: Bates T. E. , Williams S. R. , Busza A. L. , Gadian D. G. , Proctor E. 
Published: March 2007

Abstract31P NMR spectroscopy was used in conjunction with conventional biochemical techniques to study metabolic abnormalities in normal rats, in rats with CCl4‐induced acute liver failure and in rats with paracetamol‐induced acute liver failure. Studies were carried out before and after a metabolic challenge in the form of a fructose infusion. Prior to fructose infusion the ATP levels in the groups with acute liver failure were significantly lower than in control rats, despite their having a similar ATP/Pi ratio. Following a fructose infusion in control animals, the changes in phosphomonoesters, ATP and inorganic phosphate were consistent with previously reported findings. However, in both test groups the percentage changes in phosphomonoesters and ATP were significantly smaller. Intracellular pH declined in control animals, but did not change significantly in the animals with acute liver failure. Fructose clearance from the blood in control animals was not significantly different from that in animals with CCl4‐induced acute liver failure. Metabolic changes measured using a horizontal magnet were very similar to those obtained with a vertical magnet.
Effects of repeated ischemia on cerebral blood flow and brain energy metabolism
Authors: Laptook Abbot R. , Hassan Abdullah , Peterson Janet , Corbett Ron J. T. , Nunnally Ray L. 
Published: March 2007

AbstractTo determine if cerebral blood flow (CBF) and cerebral metabolic alterations during partial ischemia are affected by a prior interval of ischemia, 13 neonatal piglets were studied during two successive protocols (termed A and B), each consisting of an interval before, during and after partial ischemia induced by hypotension. Piglets were studied with either microspheres (n = 6) to measure CBF and calculate cerebral uptake of O2 and glucose or 31P nuclear magnetic resonance spectroscopy (n = 6) to measure intracellular pH (pHi) and cerebral phosphorylated metabolites. One piglet was used to determine time effects. Control values of all variables were similar during protocol A and B. In each protocol hypotension was associated with similar reductions in CBF and cerebral O2 uptake but cerebral glucose uptake differed (0.10 ± 0.05 vs 0.05 ± 0.02 mmol · min−1 · 100 g−1 during hypotension of A and B, respectively, p < 0.05). During hypotension of protocol A and B similar changes in phosphorylated metabolites and pHi occurred and were characterized by a reduction in pHi, phosphocreatine and adenosine triphosphate and an increase in inorganic phosphate. Changes in phosphate metabolites and pHi were reversible within 25 min following hypotension in both protocols. Thus, changes in CBF, cerebral O2 uptake, pHi and cerebral energy metabolism are similar during repeated episodes of partial ischemia. However, differences in cerebral glucose uptake in protocol A and B raise the possibility that the balance between energy production and utilization is altered, or alternative substrates are metabolized or enzymatic activity in the glycolytic pathway is changed.
The relationship between serum water proton t1 and protein content in the p388 leukemic mouse and the effect of chemotherapy by CIS‐diamminedichloroplatinum(ii)
Authors: Raeymaekers H. H. , Callens F. , Eisendrath H. , Atassi G. , Fossoul C. , Vandewalle J. , Gielen M. , Willem R. 
Published: March 2007

AbstractProton NMR longitudinal relaxation times (T1; 10.7 MHz; 37°C) were measured in the kidneys and blood serum of mice inoculated with P388 leukemia, and/or treated with the chemotherapeutic drug cis‐diammine‐dichloroplatinum(II) (cis‐Pt). In parallel, serum total protein content, urea and creatinine levels were determined and protein fractions were separated electrophoretically.Serum T1 was found to be 1518 ± 73 ms (1 SD) in control mice, 1670 ± 69 ms in leukemic mice, and 1380 ± 71 ms in the healthy and the leukemic cis‐Pt treated mice. The T1 increase in leukemic serum and T1 decrease in the serum of cis‐Pt injected mice are attributed to decreased and increased protein contents respectively. A detailed analysis in terms of electrophoretic fractions of serum proteins reveals that the serum relaxation rate 1/T1 is a multilinear function of the mass concentrations of the main serum protein fractions, explaining all serum T1 effects. This makes T1 a non‐specific blood parameter.The kidney T1 was found to be 311 ± 12 ms in normal mice and 334 ± 20 ms in leukemic mice. A dramatic T1 increase is observed when the mice are injected with cis‐Pt; the values are 400 ± 38 ms and 407 ± 39 ms for healthy and leukemic mice, respectively. This effect is related to the nephrotoxicity of the drug, as evidenced by serum urea and creatinine levels and protein content being higher than normal.
Factors affecting 1h NMR spectra of blood plasma: cancer, diet and freezing
Authors: Bell J. D. , Brown J. C. C. , Norman R. E. , Sadler P. J. , Newell D. R. 
Published: March 2007

AbstractSingle pulse and Hahn spin‐echo 400 and 500 MHz 1H NMR spectra from normal subjects and cancer patients are reported. No significant difference was found between the average —CH3 and —(CH2)n— lipoprotein linewidths of the two groups in contrast to a previous report. Such measurements are shown to be complicated by freezing and thawing of samples which broadens lipoprotein resonances, and by eating which sharpens them. Deconvolution of the composite lipoprotein signals enables these effects to be interpreted. Other notable features of plasma spectra are discussed including resonances for ‘acute‐phase’ glycoproteins, ketone bodies and other small molecules.
The use of immobilized ferrite to enhance the depth selectivity of in vivo surface coil NMR spectroscopy
Authors: Geoffrion Y. , Rydzy M. , Butler K. W. , Smith Ian C. P. , Jarrell Harold C. 
Published: March 2007

AbstractFerrite particles immobilized on a flexible support and arranged in a specific pattern will produce localized gradients in the homogeneous B0 magnetic field. The screening gradients are strong enough to cause inhomogeneous broadening of the NMR signals arising from the region of a specimen which is adjacent to the ferrite particles. This technique allows improvement of the depth selectivity in non‐invasive surface coil NMR spectroscopy while optimizing both the signal‐to‐noise ratio and the data acquisition time of in vivo NMR experiments. The ferrite screen method also facilitates the routine application of high resolution NMR pulse sequences to in vivo experiments. The technique is readily implemented without special hardware or software and displays a great versatility in the size, shape and depth of the screening effect.
Direct 19f NMR spectroscopic observation of 5‐fluorouracil metabolism in the isolated perfused mouse liver model
Authors: Cabanac S. , Malet‐Martino M. C. , Bon M. , Martino R. , Nedelec J. F. , Dimicoli J. L. 
Published: March 2007

AbstractA direct analysis of 5‐fluorouracil (FUra) metabolism in the isolated perfused mouse liver was carried out using 19F NMR spectroscopy. In livers treated with low (30mg/kg body weight (b.w.)) or high (180 mg/kg b.w.) doses of FUra, with (180 mg/kg b.w.) or without thymidine (dThd), FUra was rapidly catabolized to α‐fluoro‐b̃‐ureidopropionic acid (FUPA) and α‐fluoro‐b̃‐alanine (FBAL), the latter usually becoming by far the major catabolite. The first catabolite of FUra, 5,6‐dihydro‐5‐fluorouracil (5FUH2), was never detected. With the high dose of FUra with or without dThd, a signal corresponding to fluoronucleotides was detected both in the liver and in perchloric acid (PCA) extracts. In the latter, it was generally split into three signals, the major one being attributed to 5‐fluorouridine‐5′‐monophosphate. Moreover, when the liver was treated with high doses of FUra and dThd, a signal for fluoronucleoside was observed in the liver, in PCA extracts and in perfusate where it was attributed to 5‐fluoro‐2′‐deoxyuridine (FdUrd). The injection of concurrent dThd with the high dose of FUra led to a marked reduction of catabolism due to competitive inhibition of dihydrouracil dehydrogenase. Moreover, a significant formation of FdUrd was noticed whereas 5‐fluoro‐2′‐deoxyuridine‐5′‐monophosphate (FdUMP) was not detected. dThd therefore inhibits the conversion of FdUrd to FdUMP.
Direct determination of adp in hypoxic porcine carotid artery using 31p nmr
Authors: Fisher M. J. , Dillon P. F. 
Published: March 2007

Abstract31‐NMR spectroscopy was performed on vascular smooth muscle (VSM; porcine carotid artery) superfused with a substrate‐free high K+‐PSS. Scans were collected before (control), during (hypoxia), and after (post‐control) hypoxia, and chemical measurements of ATP (0.070 ± 0.13 m̈moles/g wet wt.) and creatine (2.04 ± 0.14 m̈mol/g wet wt.) were made. During hypoxia, well‐defined beta‐ADP signals were consistently resolved. Their areas indicated that after 30, 60, and 90 min of hypoxia, free ADP was 0.05 ± 0.01, 0.09 ± 0.01, and 0.12 ± 0.01 m̈mol/g wet wt., respectively. The apparent tissue equilibrium constant (Kck) for creatine kinase (CK) was calculated using 90 min hypoxic data and was 7.6 ± 0.6 × 108 M–1. It was used to compute free ADP levels (m̈mol/g wet wt.) for control (0.028 ± 0.002) and post‐control (0.23 ± 0.003) periods, since ADP signals could not be directly detected, and for the 30 and 60 min hypoxic periods (0.05 ± 0.01 and 0.08 ± 0.01, respectively). The Kck‐dependent ADP values for the 30 and 60 min hypoxic periods were the same as the ADP values determined directly from the beta‐ADP peak areas, suggesting that the CK reaction is in equilibrium in smooth muscle. These data show that 31P‐NMR provides a means of directly measuring free ADP in hypoxic smooth muscle and a more accurate means of computing free ADP levels in normoxic VSM through the use of an in situ tissue Kck vs an assumed or in vitro Kck.
The effect of methotrexate upon tumour ATP as determined by in vivo31P inversion spin transfer
Authors: Haseler Luke J. , Irving Michael G. , Doddrell David M. 
Published: March 2007

AbstractThe effect of methotrexate upon tumour growth in the hind leg muscle of rats containing a transplanted mammary adenocarcinoma was investigated by 31P magnetic resonance spectroscopy. Using inversion‐transfer techniques, ATP resonances arising from the tumour could be distinguished from those arising from surrounding skeletal muscle. Methotrexate was shown to inhibit, but not prevent, tumour growth as evidenced by the tumour ATP resonances of methotrexate treated animals compared to those of control animals. These findings correlated with decreased tumour volume and enhanced life expectancy.
Evaluation of manual methods for integration of in vivo phosphorus NMR spectra
Authors: Meyer R. A. , Fisher M. J. , Nelson S. J. , Brown T. R. 
Published: March 2007

AbstractEight human subjects measured peak integrals from a set of simulated 31P NMR spectra by triangulation, by extrapolation of tangents from the baseline of computed integrals, and by cursor demarcation of computed integrals using standard commercial software. The test spectra were qualitatively similar to phosphorus spectra routinely acquired from mammalian skeletal muscle. All three of the above methods were found to underestimate the areas of relatively broad peaks (e.g., ATP peaks were underestimated by 20–40%), even when the peak signal/rms‐noise ratio was better than 8/1. This bias resulted in major errors in calculated metabolite ratios. Of the three methods, triangulation was the least accurate, and showed the greatest variation between subjects. Cursor demarcation of computed integrals was the most accurate manual method. The same test spectra were also integrated by two fully‐automated fitting algorithms. Although not free of bias, these methods were generally superior to the manual methods.
An NMR blood test for cancer: a critical assessment
Authors: Chmurny G. N. , Hilton B. D. , Halverson D. , McGregor G. N. , Klose J. , Issaq H. J. , Muschik G. M. , Urba W. J. , Mellini M. L. , Costello R. , Papadopoulos N. M. , Caporaso N. , Smith I. C. P. , Czuba M. , Kroft T. , Monck M. , Saunders J. K. , Préfontaine M. 
Published: March 2007

AbstractAn evaluation of the reproducibility and accuracy of the NMR human blood test for cancer described by Fossel, E. T., Carr, J. M. and McDonagh, J., (New England Journal of Medicine 315, 1369–1376) in 1986 has been conducted jointly at the National Cancer Institute–Frederick Cancer Research Facility, Frederick, MD (NCI–FCRF) and the National Research Council, Ottawa, Canada (NRC). The influences on the test of the following were studied: (a) subject fasting; (b) sample collection, storage and handling; (c) use of plasma or serum; (d) variations of test results from the same individual with time; (e) NMR observation parameters including field strength and temperature; and (f) variations in obtaining the Fossel Index (FI) (a number defined by Fossel and co‐workers as the average of the widths at half height of the regions in the NMR spectrum of human plasma at 1.3 and 0.88 ppm) by different people from the same plotted spectrum. This test was found to be reproducible but not accurate for screening a general asymptomatic population. The accuracy is defined in terms of the sensitivity, specificity, and predictive values of the test. The accuracy of the test results from our laboratories is compared with the accuracies from other laboratories including Fossel's. The correlation of the Fossel Index with total triglyceride content in the serum has been confirmed by analysing blood components using the following technologies: KBr density gradient centrifugation, high resolution agarose gel electrophoresis, high performance gel permeation chromatography, and chemical analysis.