bluuebunny/crossref_metadata_2025 huggingface dataset:
Urodynamic measure of urethral cross‐sectional area: Application for obstructive uropathy
Authors: Walter James S. , Wheeler John S. , Zaszczurynski Paul , Plishka Michael
Published: March 2007

A conductance formula was developed based on pressure (P) and flow (Q) data collected from rigid tubes with a cross‐sectional area in the range of the flow controlling zone of the urethra. Curve fitting of data resulted in an exponential formula and a simple proportionality constant related tube of differing cross‐sectional area. The resulting formula estimates cross‐sectional area based on P and Q data and is in the form of a conductance ratio because Q is in the numerator and P is in the denominator. The formula is AEFm = 3.5 Q/P0.58, where AEFm is the area equivalent factor‐male and Q is measured in ml/sec and P is cm H2O

To further introduce the estimate of cross‐sectional area, urodynamics were retrospectively reviewed from 19 males over the age of 50 with complaints of prostatism. The AEFm was plotted on standard urodynamic records much like P and Q data. The onset of voiding was characterized by a rapid increase in urethral area. Maximal cross‐sectional area obtained at maximal flow was 2.9 ± 1.4 mm2. The maximal urethral area per unit of applied detrusor pressure, an estimate of urethral compliance, was 0.06 ± 0.6 mn2/cm H2O. This latter measure may help to compare patients with widely different detrusor pressures. The urodynamic data from two young adult males is also presented for comparison. Their average maximal urethral cross‐sectional area was 7.1 mm2. Their average area per unit of applied detrusor pressure was 0.15 mm2/cm H2O. These larger values contrast sharply with the BPH group. The AEFm clearly shows urethral function in terms of the principal factor regulating the urine flow rate, the urethral cross‐sectional area. © 1994 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Bladder contractility and idiopathic detrusor instability in males
Authors: Cucchi A. , Griffiths Derek
Published: March 2007

Thirty males (mean age 54 ± 13 years) with an “idiopathic” delrusor instability and fully compensated bladders (no post‐micturition residuals) were assessed urodynumically at a short distance of time (3 months, on average) from the beginning of clinical symptoms. Thirty age‐matched controls were also investigated. Detrusor shortening velocity was found to be increased in the unstable patients (P < 0.001), which seemed to derive from enhanced contractile capability in the presence of normal urethral resistance. Such data confirm the results of previous investigations in males with obstructive detrusor instability as well as in women with idiopathic unstable bladders. The significance ol these findings was discussed. In particular, it was suggested that detrusor instability may involve changes leading both to more excitable bladder smooth muscle cells and to an easier electrical coupling between the same cells, thus, to enhanced contractile capability. It was also suggested that if an impaired contractile function in unstable bladders may be the final result of a process of detrusor collagenosis. increased bladder contractility would rather characteri/.e an initial phase in the natural history of detrusor instability. © 1994 Wiley‐Liss, Inc.
Ultrasonic evaluation of bladder neck position and mobility: The influence of urethral catheter, bladder volume, and body position
Authors: Mouritsen Lone , Bach Per
Published: March 2007

The influence of urethral catheter, bladder volume, and body position on the ultrasonic assessment of bladder neck position and mobility was evaluated in 24 incontinent women. The bladder neck position was described by two independent parameters: BS‐distancc, from the bladder neck to the lower tip of the symphysis pubis. and the rotation angle between the BS‐line and the symphyseal middline.

Catheterisution resulted in apposition of the bladder neck towards the symphysis puhis, seen as a significant shortening of the BS‐distance in postmenopausal women without estrogen replacement. The rotation angle was unaffected. Increasing the bladder volume to symptomatic‐ally full resulted in increased capacity to withhold, since the rotation angle decreased 6.6°. Examination in the sitting position, compared to the supine resulted in bladder neck descent to a “lower level.” and the rotation angle increased in average 16°. Bladder neck mobility was unaffected by cathelerisalion and body position.

Vaginal ultrasonic evaluation of bladder neck suspension is recommended to be performed without a catheter, with a comfortably full bladder in a convenient, but standardised examination position. © 1994 Wiley‐Liss, Inc.
Effects of sacral dorsal rhizotomy on bladder function in patients with spastic cerebral palsy
Authors: Sweetser Philip M. , Badell Angeles , Schneider Steven , Badlani Gopal H.
Published: March 2007

A newly revised operation for controlling spasticity in cerebral palsy patients, selective dorsal rhizotomy (SDR), has the potential to affect bladder function. The goal of this multidisciplinary study is to investigate the potential change in bladder function by characterizing and comparing pre‐ and post‐operative symptoms and bladder function, both qualitatively and quantitatively, in 34 pediatric patients over the age of three with spastic cerebral palsy as the indication for selective dorsal rhizotomy.

Video urodynamics were performed in a subset of patients. Almost all patients with quadriplegia were incontinent (8/9) and none were significantly helped with bladder control. Almost half (5/11) of patients with diplegia who failed prior bladder control training were able to gain continence post‐operatively No patient experienced permanent damage to the function of their bladder.

In conclusion, selective dorsal rhizotomy using the revised technique of Peacock [Peacock et al. (1987): Pediatr Neurosci 13:61–66.] appears to be safe for spastic cerebral palsy patients' bladder function. It can help decrease symptoms and improve bladder capacity and control in almost half of those symptomatic cerebral palsy patients with diplegia.
Intravesical oxybutynin in patients with posterior rhizotomies and sacral anterior root stimulators
Authors: Singh Gurpreet , Thomas David G.
Published: March 2007

This report investigates the use of intravesical oxybutynin in spinal injury patients, who have had dorsal rhizotomies to abolish reflex detrusor activity and void with S2, S3, and S4 stimulation, done with the Brindley anterior root stimulator.

Six male patients (age range 27 to 56, mean 36 years) who have had Brindley anterior root stimulators implanted were included in this study. Video urodynamic assessment was done and 10 mg of oxybutynin hydrochloride was instilled through the urethral catheter. This was left in the bladder for 60 minutes and video urodynamics were repeated. Voiding, both pre and post oxybutynin, was achieved with sacral root stimulation.

Peak detrusor pressure (Pves) during voiding in the 6 patients before oxybutynin instillation was 89, 154, 90, 60, 56, and 80 (mean 88.2) cm of water. Post oxybutynin the pressures were 83, 163, 95, 40, 30, and 68 (mean 79.8) cm of water. The peak flow rate (Qmax) pre oxybutynin was 32, 24, 20, 20, 12, and 28 (mean 22.7) ml per second and this changed to 28, 31, 18, 24, 10, and 32 (mean 23.8) ml per second. This shows no difference in the detrusor pressure (P = 0.2) and flow rate (P = 0.54) pre and post oxybutynin instillation into the bladder.

Effectiveness of oxybutynin is attributed to a combination of M3 receptor antagonism in the smooth muscle and direct spasmolytic, local anaesthetic and calcium channel blocking action. Its therapeutic benefit is limited by the ami cholinergic side effects (40–80%) and recent studies have shown the intravesical route to be effective and better tolerated. However in this study it has been ineffective in abolishing any detrusor contractions generated by S2, S3, and S4 stimulation. © 1995 Wiley‐Liss, Inc.
Significance of rectal contractions noted on multichannel urodynamics
Authors: Combs Andrew J. , Nitti Victor W.
Published: March 2007

Independent rectal contractions are frequently noted when performing multichannel urodynamics and are often considered to be artifactual. In an effort to determine if this activity is indeed significant. we reviewed 430 consecutive multichannel urodynamic studies performed on 289 patients. All studies were performed using an analog recorder at 0.5 mm/sec paper speed. Multichannel pressures included total vesical pressure measured by a urethral catheter, total abdominal pressure measured by a rectal balloon catheter, subtracted detrusor pressure (vesical minus abdominal), and uroflow measurement when possible. Rectal contractions were defined as multiple fluctuations in abdominal pressure as measured by the rectal balloon catheter which were independent of changes in total vesical pressure. These fluctuations could not be reproduced by abdominal stressing or Kegel‐type maneuvers. Contractions were noted to be of high or low amplitude, continuous or intermittent.

Of the 289 patients, 109 (38%) had a study positive for rectal contractions. Similarly, 168 of 430 studies (38%) were positive. In patients with neurologic disease, rectal contractions were noted in 61/120 (51%). In patients with no history of neurologic disease, 48/169 (29%) had rectal contractions (P < 0.001). Furthermore, when patients without a history of neurologic disease were evaluated with respect to the presence of detrusor instability, a positive study was noted in 27/67 (40%) with instability but in only 21/102 (21%) of patients without instability (P = 0.005 ). Rectal contractions also occurred with a higher frequency in patients with bladder hyperactivity of any etiology. To further support that rectal contractions were not a randomly occurring event, a subgroup of 86 patients who had undergone multiple studies was analyzed. Studies were consistently positive or negative for rectal contractions in 86% of patients.

Rectal contractions noted on multichannel urodynamics apear to be neither artifactual nor randomly occurring events. The association with neurologic disease and detrusor hyperactivity is interesting and may indicate underlying pelvic floor dysfunction. © 1995 Wiley‐Liss, Inc.
Noninvasive quantitative method for measuring isovolumetric bladder pressure and urethral resistance in the male: I. Experimental validation of the theory
Authors: McRae L. P. , Bottaccini M. R. , Gleason D. M.
Published: March 2007

Noninvasive measurement of intravesical pressure, impulsive flow rate, and localized urethral resistance is achieved by clamping the penis immediately above the glans with a pneumatic cuff and then instructing the patient to initiate voiding. The cuff is then deflated slowly until urinary flow of at least 1 ml/s is detected and is then released rapidly to permit unimpeded flow. Cuff pressure, voided volume, and flow rate are recorded as functions of time. From the resulting tracings it is possible to determine the isovolumetric bladder pressure, the impulsive flow rate, and the flow pattern specific to the test.

We studied 53 male patients demonstrating that data thus obtained are reproducible and that the cuff pressure at the initiation of voiding does measure the bladder pressure at this moment. We then modeled the lower urinary tract by an analog electrical circuit which facilitated the analysis of the urodynamic data.

This analysis suggests that if is possible to separate the effects of bladder dysfunction from the effects of urethral resistance and to localize the resistance to the proximal or distal urethra without invasive testing. © 1995 Wiley‐Liss, Inc.
Effects of diuresis on micturition
Authors: Levin Robert M. , Wein Alan J. , Eika Berit , Tammela Teuvo L. J. , Longhurst Penelope A.
Published: March 2007

Micturition can be characterized experimentally by monitoring both the frequency and volume of micturition. Previous studies demonstrated that the functional capacity of the rat and rabbit bladder, as determined by cystometry, is approximately equal to the maximal single micturition volume as recorded over a 24 hour period. Studies in many laboratories have demonstrated that chronic increases in diuresis induce increases in micturition frequency and capacity, and an increase in bladder mass. The current study compares the temporal relationship among these parameters in three models of diuresis: streptozotocininduced diabetes in rats, sucrose‐induced diuresis in rats, and furosemide‐induced diuresis in rabbits.

In both sucrose diuresis in rats and furosemide diuresis in rabbits there were immediate increases in both the frequency and volume of micturition. The magnitude of the increases in micturition frequency and micturition volume paralleled the increase in the total volume of urine excreted. Bladder mass increased progressively over the time course of the study. Streptozotocin‐induced diabetes resulted in a more gradual (but parallel) increase in micturition frequency and volume, and again a more gradual increase in bladder mass. These studies demonstrate that functional bladder capacity is increased immediately upon the initiation of diuresis with sucrose or furosemide, as is the frequency of micturition. This indicates that functional bladder capacity is probably under neuronal regulation and the change in capacity is not a function of the increased bladder mass which occurs at a later time period. The exact stimulus for the increase in bladder mass cannot be determined from these studies, but may be related to one or more of the following factors: micturition volume, filling rate, or frequency of stimulation. © 1995 Wiley‐Liss, Inc.
Estimation of the lag time between detrusor pressure‐ and flow rate‐signals
Authors: Kranse Ries , van Mastrigt Ron , Bosch Ruud
Published: March 2007

In a urodynamic measurement setup there is a considerable spatial separation between the uroflowmeter and the location where the detrusor pressure is measured. Therefore, a “time shift” (or lag time correction) has to be applied to one of these signals in order to align related samples in studies where pressure and flow rate are considered simultaneously (e.g., assessment of bladder contractility or bladder outlet resistance).

Currently, a heuristic value for this time shift of 0.8 s is applied. In this article, we present a method to estimate the lag time directly from the measurements.

Using this method we have found, amongst others, that the mean lag time in our clinic is 0.6 s for males, 0.4 s for females voiding in sitting position, and 1.1 s for females voiding in standing position using a special receptacle in video urodynamics. Furthermore, we found that sphincter/urethral activity during voiding (which causes a drop in flow rate and an accompanying increase in detrusor pressure) is associated (on average) with shorter lag times than straining (when a positive pressure rise accompanies an increase in flow rate). Additionally strong evidence is provided that lag time correction is not a major source of error in urodynamics. © 1995 Wiley‐Liss, Inc.
Urodynamic comparison of ileum vs. sigmoid in augmentation cystoplasty for neurogenic bladder dysfunction
Authors: Radomski Sidney B. , Herschorn Sender , Stone Anthony R.
Published: March 2007

We performed multichannel urodynamics before and after augmentation Cystoplasty in 26 patients (11 females, 15 males) to determine which bowel segment is best to achieve a large volume and low pressure reservoir. All 26 patients had a neurogenic cause for their bladder dysfunction, lleum was used in 14 patients and sigmoid was used in 12 patients. Detubularization was performed in all patients. Capacity improved significantly in both the ileum and the sigmoid group after surgery. When detubularized ileum was used, the maximum amplitude of uninhibited reservoir contractions was significantly improved or eliminated postoperatively. When sigmoid was used, uninhibited reservoir contractions did not significantly improve postoperatively and were, in fact, more common than preoperatively. Despite the detubularization, pressure waves were identified in 15 of the 26 patients postoperatively. There was significant improvement in end filling pressures at capacity (compliance) with both ileum and sigmoid postoperatively. However, end filling pressures were significantly higher in the sigmoid group. In conclusion, good capacity was achieved with both ileum and sigmoid postoperatively. However, ileum provided lower reservoir pressures and better compliance. We feel that urodynamically detubularized ileum is better suited than sigmoid for augmentation Cystoplasty in patients with neurogenic bladder dysfunction. © 1995 Wiley‐Liss, Inc.
Blood flow of the urinary bladder: Effects of outlet obstruction and correlation with bioenergetic metabolism
Authors: Lin Alex Tong‐Long , Chen Ming‐Tsun , Yang Chin‐Hua , Chang Luke S.
Published: March 2007

This study investigated the effects of outlet obstruction on blood flow and high energy phosphates content in the rabbit urinary bladder. Mild bladder outlet obstruction was induced by placing a silicon ring (diameter 7 mm) around the bladder neck of each male New Zealand White rabbit (n = 7). Before and immediately after inducing obstruction, and 2 weeks later, the bladders were emptied and regional blood flow measured using laser Doppler flowmetry (LASERFLO BPM2, Vasamedics Inc., St. Paul, Minnesota). Six different areas of each bladder were measured, and the average blood flow calculated for each rabbit. Then, the animals were sacrificed, the bladder excised, and the tissue content of high energy phosphates determined by high performance liquid chromatography (HPLC). Six normal male New Zealand White rabbits served as controls. The results can be summarized as follows: (1) Before surgery, bladder blood flow was similar in all animals (16.3 ml/min/100 g); positioning the silicon ring around the bladder neck did not affect blood perfusion. two weeks after the induction of outlet obstruction, bladder blood flow was significantly decreased (4.9 ml/min/100 g). (2) There was no significant difference between control and obstructed bladders in NAD, AMP, or ADP content. However, the obstructed bladders contained significantly less phosphocreatine (12.0 vs 21.9 nmol/mg protein) and ATP (4.0 vs. 6.1 nmol/mg protein) than control bladders.

In summary, this study showed that urinary bladder blood flow was reduced by outlet obstruction, and the reduction in blood flow was associated with decreased tissue high energy phosphates content. Decreased blood flow might be an important factor in the disarranged energy metabolism and functional impairment exhibited by the urinary bladder following Outlet Obstruction. © 1995 Wiley‐Liss, Inc.
Comparison of “subjective” and “objective” measures of severity of urinary incontinence in women
Authors: Elser Denise M. , Fantl J. Andrew
Published: March 2007

The aims of this study were to compare “subjective” measures of severity of urinary incontinence to similar “objective” measures, establish their statistical correlation, and determine the effect of specific urodynamic diagnosis on such correlations. Baseline data was available from 265 women entered into a clinical trial studying pharmacologic and behavioral interventions for urinary incontinence. The “subjective” measures of incontinence were obtained by patient recall during history taking and included: the number of incontinent episodes in I week, the number of perincal pads used during I week, and the number ot clothing changes required due to wetness. The “objective” measures of severity included: the number of incontinent episodes per week as recorded on a 7‐day diary, the number of perineal pads used per week, also recorded on a diary, and the amount of fluid lost during a standardized pad test Analysis consisted of Pearson correlations and linear regressions to determine equations for the prediction of objective measurement on the basis of the corresponding subjective measure. Significant positive correlations were seen between “subjective” and “objective” measurements for the comparisons of number of weekly incontinent episodes (R = 0.63), and tor the weekly number of pads used (R = 0.81). The comparison between the number of clothing changes and the amount of fluid lost during pad testing was also significantly but less strongly correlated (R = 0.24). For the correlations between subjective and objective determinations of urinary incontinent episodes and for those between clothing changes and pad testing, the urodynamic diagnosis had no effect on the correlation coefficients, but did have a statistically significant effect on the intercept. “Subjective” measures of severity of urinary incontinence will provide a reasonable estimate of “objective” measures of severity of urinary incontinence in women. Therefore in a clinical setting, it seems logical to use “subjective” measures to assess both baseline severity and response to intervention. © 1995 Wiley‐Liss, Inc.
Some observations on a condition of relatively lower detrusor contractility in stable versus unstable unobstructed bladders
Authors: Cucchi A.
Published: March 2007

The study comprised 30 consecutive benign prostatic hypertrophy patients–15 with detrusor instability, and 15 with stable bladders–who had a relatively lower detrusor contractility with no obvious obstruction of the vesical outlet. Compared with the stable bladders, those with detrusor instability showed lower filling volumes, along with a relatively greater voiding efficiency and relatively higher values of detrusor contraction strength and contraction velocity Micturition contractions proved to be more well sustained until the end of voiding in the unstable group. It has been assumed that the factors responsible for detrusor instability also caused bladder contractile capability to relatively increase. In other words, it seemed even this extreme case could possibly support the view that detrusor instability always involves a tendency to enhanced contractile function. © 1995 Wiley‐Liss, Inc.
Preliminary report: Detrusor hyperreflexia in schizophrenia
Authors: Gupta Sanjay , Bonney William W. , Sethi Parminder S. , Hunter David R.
Published: March 2007

The object of this study was to demonstrate detrusor hyperreflexia (DH) in schizophrenic patients.

Twelve consecutive schizophrenic patients were evaluated by DSM‐IIIR diagnostic criteria and other standard psychiatric measures, urological history and examination, and urodynamic study All were referred for clinical indication, voiding dysfunction, or incontinence.

Two patients were excluded for confounding variables, mental retardation and benign prostatic hypertrophy. Of the ten evaluable patients, four hud DH.

Detrusor hyperreflexia does occur in a subset of schizophrenic patients, even in the absence of other recogni/ed disease to explain the occurrence. This relationship, previously unreported. warrants further investigation. © 1995 Wiley‐Liss, Inc.
Toward a new classification of overactive bladders
Authors: Fall Magnus , Geirsson Gudmundur , Lindström Sivert
Published: March 2007

Based on a large retrospective series, this study compares the International Continence Society's (ICS) classification of overactive bladders and a functional subtyping of our own, founded on clinical and urodynamic parameters. Functionally identical symptoms and urodynamic patterns were found within the Detrusor Hyperreflexia as well as the Unstable Detrusor categories. There are strong arguments for a revision of the current ICS classification system. © 1995 Wiley‐Liss, Inc.
Chain‐Fluorinated polyamines as tumour markers. iii. determination of geminal difluoropolyamines and their precursor 2,2‐difluoroputrescine in normal tissues and experimental tumours byin vitroandin vivo19f NMR spectroscopy
Authors: Hull W. E. , Kunz W. , Port R. E. , Seiler N.
Published: March 2007

Treatment of laboratory animals bearing transplantable tumours with α‐difluoromethylornithine, an inhibitor of ornithine decarboxylase, followed by 2,2‐difluoroputrescine allows the partial replacement of the endogenous polyamines spermidine and spermine by their fluorine‐containing analogs 6,6‐difluorospermidine and 6,6‐difluorospermine.

Quantitative determination of the chain‐fluorinated polyamines in excised tumor tissue byin vitro19F NMR spectroscopy at 11.7 T gave results similar to those obtained by extraction and HPLC analysis. The NMR methods allowed the observation of several as yet unidentified geminal difluoropolyamine metabolites with a detection threshold as low as 1 nmole/g.

Using a surface coil at 2.4 T, it was possible to detect in 10–20 min fluorinated polyamines in tumour, liver and bladder (urine) of micein vivoat concentrations of the order of 50–100 nmol/g, i.e., when 2–5% of the natural polyamines have been replaced by their fluoro analogs.

Since 6,6‐difluorospermidine and 6,6‐difluorospermine preferentially accumulate in tumours and specific tissues with enhanced polyamine metabolism, it is expected that these compounds may serve as probes for the application of19F NMR methods for tumour diagnosis and therapy control. Since significant quantities of additional fluorine‐containing polyamine metabolites were detected in some tissues,19F NMR spectroscopy will contribute to our knowledge of polyamine metabolism in normal and tumour tissue.
Carbohydrate metabolism of the rat c6 glioma. an in vivo13c and in vitro1h magnetic resonance spectroscopy study
Authors: Ross Brian D. , Higgins Robert J. , Boggan James E. , Willis James A. , Knittel Brian , Unger Stephen W.
Published: March 2007

Surface coil 13C nuclear magnetic resonance (NMR) spectroscopy was used to investigate the in vivo carbohydrate metabolism of rat C6 gliomas during and after infusion with [1‐13C]glucose. In vivo 1H‐decoupled 13C NMR spectra of the glioma following infusion with [1‐13C]glucose revealed the direct production of [3‐13C]lactic acid, [1‐13C]glycogen, and [4‐13C], [3‐13C], and [2‐13C]glutamate/glutamine. Lactate levels of in vivo gliomas increased and reached steady state levels during [1‐13C]glucose infusion, and decreased following termination of infusion. Complementary in vitro studies using supernatant media collected from C6 glioma cells incubated with media containing [1‐13C] or [6‐13C]glucose and glutamine were examined by 1H NMR spectroscopy. The [3‐(13C/12C)]lactate ratios obtained from 1H spectra of supernatant media containing [1‐13C]glucose revealed the percentage of glucose metabolized through the hexose monophosphate shunt to be 10.01 ± 0.85% (n = 3), while similar measurements of media containing [6‐13C]glucose and glutamine showed that glutaminolysis contributed 9.0 ± 1.0% of total lactate production under these conditions. Enzymatic analysis of media determined lactate production to be 139 ± 9 nmol per 106 cells per h (n = 4). These measurements demonstrate the ability of NMR to monitor brain tumor carbohydrate metabolism both in vitro and in vivo.
1H and 13C NMR studies of tissue from normal and diseased mice. Analysis of t1 and t2 relaxation profiles of triglycerides in liver
Authors: Deslauriers Roxanne , Somorjai Rajmund L. , Geoffrion Yves , Kroft Thérèse , Smith Ian C. P. , Saunders John K.
Published: March 2007

The study was initiated to gain a better understanding of the manifestation of disease in the lipid dynamics in tissue. We have performed high resolution 13C and 1H NMR relaxation measurements on the observable lipid resonances in liver and adipose tissue, excised from mice which were normal fed, normal fasted, and infected with the malarial parasite Plasmodium berghei. We have observed that, although the parasite does not invade the hepatocytes, the composition of the liver lipids changes along with nutritional status and disease state. Analysis of the liver lipids using gas chromatography showed that in all cases studied (normal or malarial, fed or fasted) the phospholipid content of the liver remains constant. The triglyceride content, however, shows an increase of up to fourfold in both 24‐hour fasted controls and highly parasitized mice. The fatty acid compositions of the triglycerides in 24‐hour fasted normal and highly parasitized mice are altered, when compared with fed controls or with mice having a low level of infection. The unsaturation index increases twofold.

The 13C T1 experiments on the methylene and olefinic resonances of liver give a single exponential decay. The value for a particular carbon is independent of the origin of the tissue, the nutritional status or the disease state of the animal. In contrast, both 1H and 13C T2 relaxation of the methylene and olefinic carbon resonances can generally be best analyzed as the sum of two exponential decays (based on an F‐test). The 13C T2 values and the pre‐exponential weighting factors are independent of the origin of the tissue examined. The T2 data could also be analyzed in terms of a distribution of relaxation times, a physically more realistic model. Lastly, our results suggest that the 1H and 13C resonances of lipids in the cells of diseased or normal liver tissues do not give rise to “long” T2 values, as have been observed in cancer cells with metastatic potential.
Hyperlipidemia as a biochemical basis of magnetic resonance plasma test for cancer
Authors: Holmes Kerry T. , Mackinnon Wanda B. , May George L. , Wright Lesley C. , Dyne Marlen , Tattersall Martin H. N. , Mountford Carolyn E. , Sullivan David
Published: March 2007

An increase in the plasma levels of apoprotein B‐containing lipoproteins is the basis of the magnetic resonance (MR) test for cancer. The narrow MR line width reported by Fossel and co‐workers to be associated with the presence of malignant disease is due to a relative increase of very low density lipoprotein. In contrast, the plasma from healthy controls, which has a much broader spectrum, has a higher proportion of high density lipoprotein. However, plasma from patients with hyperlipidemia unrelated to cancer also show narrow MR line widths and are therefore a confounding variable.

We used magnetic resonance spectroscopy (MRS) to assess the plasma from 253 patients with a range of lipid related diseases and cancer, and 28 controls. A significant difference (p ≤ 0.0005) of 10 Hz exists between the mean line width of the controls and hyperlipidemics without malignant disease. However, in patients with solid tumours a difference of 7 Hz (p ≤ 0.0005) in the mean values is recorded although there is an overlap of 6 Hz compared with the controls. Moreover the MRS method was not found to distinguish patients with lymphomas from the control population. The index was not found to be related to patient age or tumour burden.
Ph and compartmentation of isolated perfused rat liver studied by 31p and 19f nmr
Authors: Thoma William J. , Uurbil Kǎmil
Published: March 2007

The phosphorus NMR spectra of isolated perfused rat liver displays a prominent inorganic phosphate peak at 2.76 ± 0.05 ppm relative to liver glycerolphosphocholine at 0.49 ppm. From titration curves of phosphorus‐containing compounds this corresponds to a pH of 7.4. The spectra also display a shoulder on the prominent inorganic phosphate peak at 2.22 ± 0.55 ppm corresponding to a pH of 7.0. Fructose is phosphorylated in the C1 position by the liver and the resulting fructose‐1‐phosphate is located in the cytosol. From the titration curves, this compound was at pH 7.0. When inorganic phosphate was added to the perfusate, 13 of 25 livers showed two inorganic phosphate peaks resolved in the difference spectra, one originating from the perfusate, the other at pH 7.0. When large (50 mM) fructose doses were administered to the liver, the prominent peak decreased allowing two peaks to be resolved. FCCP treatment of the liver caused the two peaks to coalesce with the final pH of both the fructose‐1‐phosphate and inorganic phosphate being the same. 19F NMR of difluoromethylalanine gave an intracellular pH of 7.4 for the isolated perfused liver. The data presented do not lend themselves to satisfactory interpretation, and call into question the correctness of the traditional assignment of liver inorganic phosphate being cytosolic in origin.
In vivo31P NMR spectroscopy of the rat cerebral cortex during acute hepatic encephalopathy
Authors: Deutz N. E. P. , Chamuleau R. A. F. M. , De Graaf A. A. , Bovée W. M. M. J. , De Beer R.
Published: March 2007

During the development of acute hepatic encephalopathy, induced by acute liver ischemia, changes in brain 31P NMR spectra and EEG spectra were studied over 8:45 h in eight rats. At the end of this period the brain amino acid concentrations were determined. The results were compared with the same measurements in four normal and three portacaval shunted rats. Signs of acute HE, as judged by the EEG left index, started 5 h after the induction of acute liver ischemia. No accompanying significant changes in the cortical relative phosphocreatine and ATP concentration and intracellular pH were observed. The cortical relative Pi concentration had only slightly increased at t = 8 h. The concentrations of almost all measured brain amino acids, especially glutamine had increased at t = 8:45 h. At t = 8 h, rats with very severe HE had a small, but significant decrease of brain ATP concentrations. Their brain amino acid concentrations were more disturbed than in rats with less severe HE. It is concluded that a change in the cortical cerebral energy rich phosphate concentration is not an important pathophysiological mechanism during the development of acute HE. The observed changes in brain amino acids concentrations could be either part of a multifactorial pathogenesis or could be epiphenomena.
Improvement of the rotating frame experiment by detection of residual z magnetization: a 31P MRS study of metabolite levels in a meth‐a sarcoma
Authors: Karczmar G. S. , Shine N. , Lawry T. J. , Weiner M. W. , Matson G. B.
Published: March 2007

The radio frequency field (B1) gradient of a surface coil can be used to obtain spectra from a series of sample regions which experience different B1 field strengths. We previously reported that the sensitivity of this method, known as the surface coil rotating frame experiment (SCRFE), can be enhanced by applying a composite pulse immediately after signal acquisition to sample residual Z magnetization which is normally undetected. Initially this modified SCRFE was used to obtain spatially resolved spectra across a B1 gradient of a factor of 2.5. Here we demonstrate the extension of this method to map phosphorylated metabolites across a B1 gradient of a factor of close to 5. Computer simulations were used to evaluate the performance of the composite pulse, and to assist in analyzing the data. The method was used to obtain 31P spectra in vivo from various tissue layers within and beneath a murine Meth‐A tumor. The spectra differentiated between metabolite levels in tumor tissue and underlying skeletal muscle. Metabolic heterogeneity within the tumor itself was also evident.
A 13C NMR study on fluxes into the krebs cycle of rabbit renal proximal tubular cells
Authors: Jans Arnold W. H. , Leibfritz Dieter
Published: March 2007

Suspensions of rabbit renal proximal tubular (PCT) cells were incubated with [2‐13C] and [3‐13C]pyruvate. The perchloric acid extracts of the cell pellets were examined by 13C NMR. All experiments showed that enriched lactate, alanine, glutamate, and glutamine were the main metabolic intermediates, and that enrichment to a minor extent was found in the glutamate residue of glutathione (GSH). From these experiments, it could be deduced that PCT cells show a highly glycolytic activity, whereas enrichment of glucose exhibits gluconeogenesis. The estimation by 13C NMR of the ratio of the flux into the Krebs cycle via pyruvate carboxylase to the flux via pyruvate dehydrogenase is discussed. From incubations with 10 mM 13C‐labelled pyruvate, we calculated from the relative enrichments of the glutamate carbon atoms that the ratio of pyruvate carboxylase to pyruvate dehydrogenase is 1.44 ± 0.04 in rabbit renal proximal tubules.
Broadband proton decoupling in human 31p NMR spectroscopy
Authors: Luyten Peter R. , Bruntink Gerard , Sloff Frenk M. , Vermeulen Jan W. A. H. , Van Der Heijden Jan I. , Den Hollander Jan A. , Heerschap Arend
Published: March 2007

The limited chemical shift dispersion of in vivo 31P NMR spectra obtained at the relatively low field strengths used for human applications is the cause of poor spectral resolution. This makes it difficult to obtain accurate quantitative information from overlapping resonances, and interesting resonances may be obscured. At 1.5 T unresolved 1H–31P couplings contribute significantly to the linewidth of in vivo 31P NMR resonances. Therefore, proton decoupling can improve spectral resolution substantially, resulting in better resolved resonances and more reliable quantitative information. In this work it is shown that well resolved resonances of glycerophosphocholine, glycerophosphoethanolamine and phosphoethanolamine are obtained in 1H decoupled 31P NMR spectra of human muscle, brain, and liver. In spectra of the human heart it has been possible to resolve the myocardial Pi signal from the signals of 2,3‐diphosphoglycerate from blood. With surface coils it is difficult to achieve broadband decoupling over the entire sensitive region of the coil by using conventional decoupling sequences. This problem has been overcome by applying a train of frequency modulated inversion pulses to achieve proper decoupling despite B2 inhomogeneity. Broadband 1H decoupling of 31P NMR spectra was possible without exceeding specific absorption rate guidelines.
Image localized 31P magnetic resonance spectroscopy of the human liver
Authors: Glazer Gary M. , Smith Stephen R. , Chenevert Thomas L. , Martin Peter A. , Stevens Anthony N. , Edwards Richard H. T.
Published: March 2007

Image localized 31P magnetic resonance (MR) spectroscopy of the liver was performed in twelve normal volunteers and seven patients with hepatic tumours. The tumours which were clearly imaged by proton MR could also be distinguished from normal tissue because of spectral differences. The malignant tumours had significantly elevated phosphomonoester/inorganic phosphate and phosphomonoester/b̃‐adenosine triphosphate ratios, probably due to elevated tumour concentrations of phosphocholine and phosphoethanolamine, which are intermediates in the synthesis of membrane phospholipids. The pH values of the malignant tumours were elevated compared to normal hepatic parenchyma. Liver spectra in two patients with the commonest benign hepatic neoplasm, cavernous haemangioma, differed from both normal tissue and the malignant tumours in having a very low signal/noise ratio but apparently normal relative levels of phosphomonoester.
31P magnetic resonance spectroscopy of the normal human brain: approaches using four dimensional chemical shift imaging and phase mapping techniques
Authors: Coutts Glyn A. , Bryant David J. , Collins Alan G. , Jane Cox I. , Sargentoni Janet , Gadian David G.
Published: March 2007

The use of four‐dimensional chemical shift imaging to monitor phosphorus metabolites within the human brain is illustrated. Saturation effects are described, and acquisition conditions are discussed in relation to quantification and sensitivity. The effects of magnetic field variations on spectral parameters are assessed and the use of a field mapping technique is illustrated.
An NMR Assessment of the Rheological Properties of Blood and Its Constituents: A Review
Authors: Berling C. , Hall L. D.
Published: March 2007

This review assesses the progress of NMR in the field of hemorheology, i.e., the assessment of the mechanical and physical characteristics of flowing blood. The review deals with the intrinsic rheological properties of the red cell and its constituents (membrane, cytoplasm), which are dominant in the microcirculation, and a section concerns the investigation of the cell/cell interaction phenomenon, known to give rise to the complicated non‐Newtonian behavior of blood under most of the flow conditions encountered in the blood circulation using NMR.
Injury and Recovery of the Liver from Preservation Assessed by 31P NMR Spectroscopy: The Contrast between Preservation with Collins' Solution and Ringer's Lactate Solutiond̊
Authors: Vine William , Link John , Thoma William J. , Uǧurbil Kâmil
Published: March 2007

The biochemistry of hepatic injury and recovery from preservation for transplantation was studied in rat liver perfused in vitro with erythrocytes. ATP and its metabolites, inorganic phosphate (P1) and pH were quantitated as often as every 2.5 min by 31P NMR spectroscopy during preservation and recovery. Release of the hepatocellular enzymes, lactate dehydrogenase V (LDV) and aspartate aminotransferase (AST) were also measured. The duration of preservation with Collins' solution, the standard clinical preservative, affected the rate of recovery of ATP and monophosphate esters (MP), which include AMP + IMP, and the final recovery of Pi, but not of ATP. The difference between Collins' and Ringer's lactate solution, a poor preservative, became more apparent as preservation time increased. The differences included (1) pH at the end of preservative infusion; (2) pH between 0 and 2.5 min of reperfusion; (3) the MP increase (AMP + IMP) at the end of 13 h of preservation; (4) rate of recovery of ATP after preservation; (5) final ATP recovery during reperfusion; (6) LDV after 13 h of preservation. These biochemical differences between good and poor preservation form a rational basis for prediction of liver failure after transplantation and for tests of the quality of new preservatives.
Limits of tumour treatment follow up by surface coil 31P magnetic resonance spectroscopy. The case of sarcosinamide‐CNU treated ependymoblastoma
Authors: Le Moyecd̊ L. , Le Rumeur E. , Darcel F. , Chatel M. , De Certaines J. D. , Remy C. , François A. , Lotito S. , Benabib A. L.
Published: March 2007

Ependymoblastoma tumour bearing mice were treated with sarcosinamide‐CNU and compared with untreated mice with regard to tumour growth, pathological examinations and levels of phosphorylated metabolites measured by in vivo nuclear magnetic resonance spectroscopy. The response to the drug was demonstrated by its effect on tumour growth and with pathological examinations. Spectra evolution was different from controls for only four treated tumours out of eight.
A Selective excitation/B0 gradient technique for high‐resolution 1H NMR studies of metabolites via zero‐quantum coherence and polarization transfer
Authors: Doddrell David M. , Brereton Ian M.
Published: March 2007

A new method for selective observation of scalar coupled metabolites by either zero‐quantum coherence transfer or polarization transfer with concurrent water suppression in a single acquisition was developed. Gaussian shaped RF pulses were used to selectively generate multiple‐quantum and zero‐quantum coherence in the metabolite of interest, single quantum (including water) and double quantum coherences were then dephased under the influence of a B0 field gradient and the surviving zero‐quantum coherence was converted to observable metabolite signal. The duration of the gradient application and the frequency and angle of the final selective read pulse determined whether a polarization transfer or a coherence transfer signal was observed.

Water suppression factors of around 8000 were achieved which allowed operation of the receiver at high gain levels resulting in greatly improved signal to noise in the metabolite spectra. The CH3 and CH resonances of lactate in a mouse brain homogenate were selectively edited and the method was also applied to selective editing of ethanol.
In vivo pharmacokinetics of aldose reductase inhibitors: 3‐fluoro‐3‐deoxy‐D‐glucose NMR studies in rat brains
Authors: Kwee Ingrid L. , Nakada Tsutomu
Published: March 2007

Direct quantification of the inhibitory effects of orally administered drugs (sorbinil, cyclandelate and sulindac) on aldose reductase activities in rat brains was performed non‐invasively using the 3‐fluoro‐3‐deoxy‐D‐glucose (3‐FDG) 19F NMR spectroscopic technique. Quantitative data obtained directly from the target organ (brain) allowed for unprecedentedly accurate analysis of drug effects in the brain in vivo. Sorbinil, a potent aldose reductase inhibitor, exhibited a classic monophasic organ response, whereas cyclandelate and sulindac showed biphasic suppression patterns. The latter indicate that there are metabolites of these drugs which possess aldose reductase inhibitory activities. The estimated potency of aldose reductase inhibition for each of the three drugs in this study was significantly discrepant from the in vitro studies indicating the complicated nature of the bioavailability of a pharmaceutical agent in vivo, especially where pharmacologically active metabolites of a given drug are involved. Our method allows for a direct quantitative assay and hence the most reliable technique for evaluating aldose reductase inhibitory activities in the target organ.
Rubidium transport in human erythrocyte suspensions monitored by 87rb NMR with aqueous chemical shift reagents
Authors: Helpern J. A. , Welch K. M. A. , Halvorson Herbert R.
Published: March 2007

Dysprosium(III) triethylenetraamine‐N,N,N′,N″,N‴,N‴‐hexaacetic acid (DyTTHA3–) was used as an aqueous chemical shift reagent in conjunction with high‐resolution nuclear magnetic resonance (NMR) spectroscopy to monitor 87‐rubidium (87Rb+) transport in human erythrocyte suspensions. NMR spectra demonstrated two resonances which were assigned to the intra‐ and extracellular compartments of the erythrocyte suspension. Uptake of 87Rb+ was shown to proceed via the [Na,K]‐ATPase dependent pump as evidenced by the inhibition of uptake in the presence of ouabain. The steady state intra‐ to extracellular concentration ratio of 87Rb was 3.00 and 1.13 in the absence and presence of ouabain, respectively. The rate of uptake of 87Rb+ in the absence and presence of ouabain was found to be 1.3 and 0.5 mmol Rb+/L erythrocytes/h at 18 mM Rb+, respectively. Data are also presented which indicate that the intracellular component of 18Rb is less than 100% NMR visible.
Maternal and cord blood plasma. Comparative analyses by 1H NMR spectroscopy
Authors: Bell Jimmy D. , Brown Judith C. C. , Sadler Peter J. , Garvie Dorothy , Macleod Andrew F. , Lowy Clara
Published: March 2007

Normal and ‘Hahn’ spin‐echo 500 MHz 1H NMR spectra of 21 pairs of plasma from mother and cord taken at the time of delivery are reported. The concentrations of ‘NMR‐visible’ lactate, alanine, and valine in the cord plasma significantly exceed those in the maternal plasma. In both maternal and cord plasma, measured lactate levels appear to increase with the length of the second stage of labour. Ethanol was unexpectedly detected in five samples of cord plasma. Lipoprotein —CH3 and —(CH2)n— resonances are more intense in the spectra of maternal plasma compared to cord plasma, and are unusual in composition. The intensities of N‐acetyl signals from ‘acute‐phase’ plasma glycoproteins are greater in spin‐echo spectra of maternal plasma compared to those of cord plasma (mean ratio 2.1 (SD 0.8)). These results suggest that high resolution NMR spectroscopy may provide a useful new insight into the comparative biochemistry of maternal and cord plasma.
31P magnetic resonance spectroscopy of chronic cerebral infarction in rats
Authors: Houkin Kiyohiro , Nakada Tsutomu , Suzuki Nobuyuki , Kwee Ingrid L.
Published: March 2007

The chronological changes in the pattern of 31P magnetic resonance spectroscopy (MRS) associated with cerebral infarction were studied in rats. 31P MRS of chronic infarction (1 month after induction of infarction) clearly showed a pattern distinct from that of normal brain. In chronic infarction, the relative phosphomonoester (PME) level was found to be significantly higher and relative phosphocreatine (PCr) level significantly lower compared to normal brain. The intracellular pH and the relative inorganic phosphate (Pi) level did not show any significant differences. Histological examination indicated that the 31P MRS pattern of chronic infarction reflects gliosis.