bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence of anemia in pediatric cancer patients in Europe: Results of a large, international survey
Authors: Michon Jean
Published: September 2002

Background

Anemia occurs frequently in children with cancer, but there is little information quantifying the incidence of anemia or treatment. A survey was conducted in 1998 in Europe by The Research Partnership with the objective of determining the incidence of anemia, identifying the hemoglobin triggers that initiated anemia treatment, and the current anemia treatment options available to clinicians.

Procedure

The survey was conducted in the 10 largest pediatric oncology centers each in France, Germany, Italy, Spain, and the UK, and in the 8 largest centers in both Belgium and The Netherlands. Telephone interviews with the most senior physician available in the institution were used to collect data, which included the numbers of patients treated or under follow‐up, cancer types, and treatment practices for anemia.

Results

Data were collected for 25,093 patients. Over 80% of patients were anemic (WHO: hemoglobin ≤ 11 g/dL; EORTC: hemoglobin ≤ 12 g/dL) regardless of tumor type; 97% of patients with leukemia, the most prevalent type of cancer (34% of the total population), were anemic. Decreases in hemoglobin levels to between 5.5 and 8.0 g/dL were the most common factor that precipitated anemia treatment. Treatment was almost exclusively blood transfusion; less than 5% of patients received drug treatment (which consisted mostly of folic acid or iron). Very few patients received recombinant human erythropoietin (rHuEPO, epoetin alfa) to treat anemia.

Conclusions

In general, clinicians were not able to give advantages or disadvantages of epoetin alfa as a treatment option for treating anemia in children with cancer, which reflects the limited knowledge of and experience with this agent. Med Pediatr Oncol 2002;39:448–450. © 2002 Wiley‐Liss, Inc.
Is epoetin alfa a treatment option for chemotherapy‐related anemia in children?
Authors: Büyükpamukçu Münevver , Varan Ali , Kutluk Tezer , Akyüz Canan
Published: September 2002

Background

The efficacy and safety of epoetin alfa in ameliorating cancer‐ or chemotherapy‐related anemia and reducing red blood cell (RBC) transfusion requirements have been demonstrated in numerous trials in adult patients. However, limited information is available about recombinant human erythropoietin (rHuEPO, epoetin alfa) as a treatment option in pediatric cancer patients.

Procedure

To gain more information about the efficacy and safety of epoetin alfa in the treatment of chemotherapy‐induced anemia in children with solid tumors receiving either platinum‐ or nonplatinum‐containing chemotherapy, an 8‐week randomized trial was conducted. Epoetin alfa 150 IU/kg was given 3 times a week for 8 weeks to 17 patients; 17 control patients received standard of care.

Results

Transfusions, administered if the hemoglobin (Hb) level dropped to below 6 g/dL, were necessary for only one patient in the epoetin alfa group, as compared with eight patients in the control group (change in Hb from 8.5–10.21 g/dL in the epoetin alfa group vs. 8.48–8.41 g/dL in the control group).

Conclusions

The data from this study suggest that this dosing regimen of epoetin alfa is effective and safe in pediatric cancer patients with chemotherapy‐related anemia. Further studies with epoetin alfa in more children with different chemotherapy regimens are needed. Med Pediatr Oncol 2002;39:455–458. © 2002 Wiley‐Liss, Inc.
Early epoetin alfa treatment in children with solid tumors
Authors: Zoubek Andreas , Kronberger Martina
Published: September 2002

Background

Combination chemotherapy is often used for long periods in children with solid malignancies, leading to anemia and necessitating intervention with red blood cell (RBC) transfusions. Transfusions, however, are associated with a variety of adverse events and risks. Recombinant human erythropoietin (rHuEPO, epoetin alfa) has been shown to reduce the need for transfusions and to ameliorate the symptoms of anemia in adults, but few studies have been conducted thus far in pediatric patients.

Procedure

Thirty‐seven children with solid tumors receiving treatment with platinum‐ or nonplatinum‐based chemotherapy were treated with epoetin alfa and supplemental iron in a single‐center, open‐label, 28‐week, case‐control study.

Results

Epoetin alfa significantly reduced the need for RBC (P = 0.007) and platelet (P = 0.01) transfusions, and prolonged the time to first RBC transfusion (P = 0.0004) as compared to the control group. Moreover, epoetin alfa was effective in maintaining mean hemoglobin levels during the course of the study, whereas they declined below baseline after week 9 in the control group.

Conclusions

Epoetin alfa is effective and safe in reducing transfusion requirements and maintaining adequate hemoglobin levels in children with solid tumors undergoing combination chemotherapy. Med Pediatr Oncol 2002; 39:459–462. © 2002 Wiley‐Liss, Inc.
Recombinant human erythropoietin in pediatric oncology: A review
Authors: Feusner James , Hastings Caroline
Published: September 2002

Background

Numerous reports on recombinant human erythropoietin (rHuEPO, epoetin alfa) treatment of cancer‐related anemia in adult patients have been published to date. These have shown that epoetin increases hemoglobin levels, significantly ameliorates symptoms of anemia, and improves adult patients' quality of life. Unfortunately, less is known about the impact of epoetin on anemia in pediatric cancer patients.

Procedure

It is the objective of this review to summarize and analyze data of clinical trials of epoetin treatment of anemia in pediatric cancer patients.

Results

A total of 15 studies were reviewed; eight were considered for detailed analysis and demonstrated important variabilities in study methods. Four of the eight were controlled, randomized trials and four were open label.

Conclusions

These studies suggested an overall beneficial effect of epoetin alfa for treating anemia in children with cancer. Three large, multicenter clinical trials of the efficacy and safety of epoetin alfa in anemic children with cancer are currently underway, one in Europe and two in North America. Med Pediatr Oncol 2002; 39:463–468. © 2002 Wiley‐Liss, Inc.
Evaluation of segregation patterns of 21;21 Robertsonian translocation along with sex chromosomes and interchromosomal effects in sperm nuclei of carrier by FISH technique
Authors: Acar Hasan , Yildirim M. Selman , Çora Tülin , Ceylaner Serdar
Published: September 2002

Meiotic segregation patterns of carriers of Robertsonian translocations (RT) are important for assessing the risk of unbalanced forms. We investigated the ratio of sperm with t(21;21) to sperm with nullisomy for chromosome 21; the segregation of the t(21;21) along with sex chromosomes, and also interchromosomal effects on chromosome 10 by using three color fluorescence in situ hybridization (FISH) with telomere specific (Tel 21q) and centromere‐specific alpha satellite probes for chromosomes X, Y, and 10. The percentage of cosegregation of t(21;21) with sex chromosomes (49.50%) and without sex chromosomes (46.98%) was not significant. There are no significant differences between the percentages of cosegregation of t(21;21) with chromosome X (23.36%) and with chromosome Y (26.16%). No evidence of an interchromosomal effect on chromosome 10 was detected, the percentage of chromosome 10 aneuploidy being similar to that in controls. In addition, the frequency of diploid sperm nuclei was not significantly higher in the carrier (0.32%) than in the controls (0.44%) (P > 0.05). The sex ratio was similar within the carrier and the controls and between the carrier and the control. Three color‐FISH analysis, using different probe combinations, seems a rapid and accurate tool for direct analysis of meiotic segregation product. Mol. Reprod. Dev. 63: 232–236, © 2002 Wiley‐Liss, Inc.
Control of the annual testicular cycle of the marbled‐newt by p53, p21, and Rb gene products
Authors: Ricote Monica , Alfaro Juan M. , García‐Tuñón Ignacio , Arenas M. Isabel , Fraile Benito , Paniagua Ricardo , Royuela Mar
Published: September 2002

p53, p21, and Rb are proteins with an important role in cell‐cycle control. The expression and distribution of these gene products and the apoptotic rate were studied in the marbled‐newt testis along the annual cycle to know the role of these factors in the control of spermatogenesis and glandular tissue formation. The study was carried out using Western blot analysis and immunohistochemistry. The results differed from those, previously reported in mammals showing constant spermatogenesis. Greater expression of p53 and p21 was found in the quiescence period and was detected in PCGs (primordial germ cells), spermatogonia, follicular, interstitial cells, and glandular tissue. Greater expression of Rb and phosph‐Rb was present in the proliferation period, in PCGs, and spermatogonia. Apoptosis was only detected in secondary spermatogonia (quiescence and spermiogenesis periods) and primary spermatocytes (proliferation and spermiogenesis periods). In the quiescence period, the increase in p53 expression activates p21 expression, which inhibits Rb phosphorylation and arrests the cell cycle in G1. In the proliferation period and, in a lesser degree, in the spermiogenesis period, the expressions of p53 and p21 decrease and phosph‐Rb increases, enhancing cell proliferation. These gene products do not seem to be related to apoptosis Mol. Reprod. Dev. 63: 202–209, 2002. © 2002 Wiley‐Liss, Inc.
Expression of leukemia inhibitory factor receptor and gp130 in mouse uterus during early pregnancy
Authors: Ni Hua , Ding Nai‐Zheng , Harper Michael J.K. , Yang Zeng‐Ming
Published: September 2002

Leukemia inhibitory factor (LIF) is essential for implantation of mouse embryos. The aim of this study was to assess the expression and regulation of LIF receptor (LIFR) and gp130 mRNA in mouse uterus during early pregnancy using in situ hybridization and reverse transcription‐polymerase chain reaction (RT‐PCR). A strong level of LIFR mRNA signal was detected in the luminal epithelium on day 5 of pregnancy. On day 6–8 of pregnancy, LIFR signal was mainly localized in the decidua. LIFR signal in the luminal epithelium of ovariectomized mouse was slightly stimulated by a combination of progesterone and estrogen. By RT‐PCR, LIFR mRNA signal was detected in all of the uteri from day 1–8 of pregnancy, being at the highest level on day 5. A low level of gp130 mRNA signal was seen in the glandular epithelium on day 3 of pregnancy and reached a high level on day 4 of pregnancy. gp130 signal in the decidua appeared on day 6 of pregnancy and reached a high level on day 7 and 8 of pregnancy. After the ovariectomized mouse was treated with a combination of progesterone and estrogen, a strong gp130 signal was observed in the glandular epithelium, while no signal was detected after progesterone or estrogen treatment alone. By RT‐PCR analysis, gp130 mRNA was detected in all of the uteri from day 1–8 of pregnancy, being at the highest level on day 4 of pregnancy. Additionally, a high level of LIFR and gp130 mRNA signal was detected in the decidua under artificial decidualization compared to the control uninjected horn. The co‐expression of a high level of LIFR and gp130 mRNA in the decidua may play a key role during the decidualization and placentation Mol. Reprod. Dev. 63: 143–150, 2002. © 2002 Wiley‐Liss, Inc.
Differential cytoplast requirement for embryonic and somatic cell nuclear transfer in cattle
Authors: Du Fuliang , Sung Li‐Ying , Tian X. Cindy , Yang Xiangzhong
Published: September 2002

Effective activation of a recipient oocyte and its compatibility with the nuclear donor are critical to the successful nuclear reprogramming during nuclear transfer. We designed a series of experiments using various activation methods to determine the optimum activation efficiency of bovine oocytes. We then performed nuclear transfer (NT) of embryonic and somatic cells into cytoplasts presumably at G1/S phase (with prior activation) or at metaphase II (MII, without prior activation). Oocytes at 24 hr of maturation in vitro were activated with various combinations of calcium ionophore A23187 (A187) (5 μM, 5 min), electric pulse (EP), ethanol (7%, 7 min), cycloheximide (CHX) (10 μg/ml, 6 hr), and then cultured in cytochalasin D (CD) for a total of 18 hr. Through a series of experiments (Exp. 1–4), an improved activation protocol (A187/EP/CHX/CD) was identified and used for comparison of NT efficiency of embryonic versus somatic donor cells (Exp. 5). When embryonic cells from morula and blastocysts (BL) were used as nuclear donors, a significantly higher rate of blastocyst development from cloned embryos was obtained with G1/S phase cytoplasts than with MII‐phase cytoplasts (36 vs. 11%, P < 0.05). In contrast, when skin fibroblasts were used as donor cells, the use of an MII cytoplast (vs. G1/S phase) was imperative for blastocyst development (30 vs. 6%, P < 0.05). Differential staining showed that parthenogenetic, embryonic, and somatic cloned BL contained 26, 29, and 33% presumptive inner cell mass (ICM) cells, respectively, which is similar to that of frozen‐thawed in vivo embryos at a comparable developmental stage (23%). These data indicate that embryonic and somatic nuclei require different recipient cytoplast environment for remodeling/ reprogramming, and this is likely due to the different cell cycle stage and profiles of molecular differentiation of the transferred donor nuclei Mol. Reprod. Dev. 63: 183–191, 2002. © 2002 Wiley‐Liss, Inc.
Mouse transgenic for murine oviduct‐specific glycoprotein promoter‐driven simian virus 40 large T‐antigen: Tumor formation and its hormonal regulation
Authors: Miyoshi Ichiro , Takahashi Kazuhiro , Kon Yasuhiro , Okamura Tadashi , Mototani Yasumasa , Araki Yoshihiko , Kasai Noriyuki
Published: September 2002

Transgenic mice were generated in which a 2.2‐kb segment of the 5′‐flanking sequence of the mouse oviduct‐specific glycoprotein (OGP) gene was used to drive expression of the simian virus 40 large T antigen (Tag). These mice spontaneously developed tumors in the female reproductive tract. Analysis using reverse transcriptase‐polymerase chain reaction showed that the 2.2‐kb OGP 5′‐flanking region drove Tag mRNA expression in the oviduct, uterus, vagina, and ovary, but not in other tissues. Histological and immunohistochemical analyses revealed that the tumor cells were distributed in the oviduct, endometrium, myometrium, and vagina; and had atypical features, abnormal mitosis, and Tag expression. Ovariectomy suppressed Tag expression, and thereby, blocked tumorigenesis in the transgenic mice. Estradiol administration to ovariectomized transgenic mice led to dramatic hyperplasia of the reproductive tract tissues in association with enhanced Tag expression, both in intensity and distribution. These results demonstrated that a 2.2‐kb fragment of the 5′‐flanking sequence of the mouse OGP gene was capable of directing the expression of Tag and inducing tumorigenesis in female reproductive tract tissues in an estrogen‐dependent manner. Estrogen response elements present in the promoter region were functional in vivo. These transgenic mice represent a unique model, since they develop tumors in the oviducts as well as in other tissues derived from the Mullerian duct. Mol. Reprod. Dev. 63: 168–176, 2002. © 2002 Wiley‐Liss, Inc.
Two messenger RNA isoforms of the gonadotrophin‐releasing hormone receptor, generated by alternative splicing and/or promoter usage, are differentially expressed in rainbow trout gonads during gametogenesis
Authors: Madigou Thierry , Uzbekova Svetlana , Lareyre Jean‐Jacques , Kah Olivier
Published: September 2002

The recent cloning of a gonadotrophin‐releasing hormone receptor (GnRH‐R) cDNA from rainbow trout showed that it contains several in‐frame ATG codons, one of which, ATG2, corresponds to that found in other species. However, an upstream codon, ATG1, could give rise to a protein with a larger extracellular domain. Using S1 nuclease assay and a method combining primer extension and RACE‐PCR, we characterized a second population of mRNA, termed mRNA‐2, with a distinct 5′untranslated region and lacking ATG1. The genomic origin of the two mRNAs was determined by establishing the complete gene structure, which shows, for the first time in a vertebrate species that an alternative splicing and promoter usage generate two GnRH‐R mRNA variants whose 5′ extremities are encoded by two different exons. The analysis of the tissue distribution indicated that mRNA‐2 presents a broader pattern of expression and is detected at higher levels than mRNA‐1. Interestingly, it was found that those two mRNAs are differentially expressed in male and female gonads during gametogenesis. In particular, the variations of mRNA‐1 levels parallel those of sGnRH expression during spermatogenesis, indicating that tissue‐specific processing of the GnRH‐R mRNA may underlie the effects of GnRH as a paracrine/autocrine regulator of gonadal functions Mol. Reprod. Dev. 63: 151–160, 2002. © 2002 Wiley‐Liss, Inc.
Position‐independent and tissue‐specific expression of porcine whey acidic protein gene from a bacterial artificial chromosome in transgenic mice
Authors: Rival‐Gervier Sylvie , Viglietta Céline , Maeder Caroline , Attal Joe , Houdebine Louis‐Marie
Published: September 2002

Silencing of transgenes is a frequent event after the random integration of foreign DNA in the host genome following microinjection. Long genomic fragments are expected to contain all the regulatory elements necessary to induce an appropriate expression of transgenes. A bacterial artificial chromosome containing the porcine wap gene with approximately 145 and 5 kb of 5′‐ and 3′‐flanking sequences, respectively, was microinjected into fertilized mouse ovocytes. In the six transgenic lines studied, expression was strictly specific to the mammary gland of lactating animals and was position‐independent. Levels of exogenous porcine wap mRNA per copy compared favorably with the porcine wap mRNA yield in the mammary gland of a 9‐day lactating pig. These findings suggest that this insert contained most if not all of the cis‐acting elements involved in the full specific expression of the porcine wap gene. These elements constitute good candidates for directing the optimized expression of protein recombinant‐encoding genes in the mammary gland of lactating animals Mol. Reprod. Dev. 63: 161–167, 2002. © 2002 Wiley‐Liss, Inc.
Orientational dependence of T2 relaxation in articular cartilage: A microscopic MRI (μMRI) study
Authors: Xia Yang , Moody Jonathan B. , Alhadlaq Hisham
Published: September 2002

The experiments reported herein are the first MRI investigations of the orientational dependence of T2 relaxation in articular cartilage at microscopic resolution over the 360° angular space. For each of six canine cartilage specimens, 48 independent T2‐weighted proton images were acquired for 12 different specimen orientations. Pixel‐wise monoexponential fits of these proton images produced 12 T2 relaxation images, each with an in‐plane pixel resolution of 13.7 μm. Cartilage T2 as a function of specimen orientation was shown to follow approximately the angular dependence of the nuclear dipole–dipole interaction, with local maxima at approximately 55°, 125°, 235°, and 305°. However, the relative amplitudes of the T2 maxima deviated somewhat from those expected from the dipolar interaction. The amplitudes of these maxima also varied with tissue depth: the largest amplitudes were found in the radial zone, intermediate amplitudes were found in the superficial zone, and there was a continuous decrease in amplitude approaching the transitional zone from the superficial zone above and the radial zone below. We explain the discrepancy between the observed T2 anisotropy and the angular dependence of the dipolar interaction by means of a simple model which considers the average of one isotropic and two anisotropic spin populations—the first being associated with “free” water, and the latter two arising from collagen‐associated waters. We show that even for the “long” T2 components, which arise in multiple‐compartment studies of collagen‐water systems, there appears to be two subpopulations. Each has the same peak value of T2, but the angular dependence of one is shifted in phase by 90° relative to the other by virtue of the fact that each is associated with groups of mutually perpendicular fibrils. Magn Reson Med 48:460–469, 2002. © 2002 Wiley‐Liss, Inc.
k‐Space interpretation of the Rose Model: Noise limitation on the detectable resolution in MRI
Authors: Watts Richard , Wang Yi
Published: September 2002

Noise limitation on the detected spatial resolution, described by the Rose Model, is well known in X‐ray imaging and routinely used in designing X‐ray imaging protocols. The purpose of this article is to revisit the Rose Model in the context of MRI where image data are acquired in the spatial frequency domain. A k‐space signal‐to‐noise ratio (kSNR) is introduced to measure the relative signal and noise powers in a circular annulus in k‐space. It is found that the kSNR diminishes rapidly with k‐space radius. The Rose criterion that the voxel SNR ∼4 is translated to kSNR cutoff values was tested using theoretical derivation and experimental histogram analysis. Experiments demonstrate that data acquisition beyond this cutoff k‐space radius adds little or no information to the image. In order to reduce the noise limit on spatial resolution, the signal strength must be improved through means such as increasing the coil sensitivity, contrast enhancement, and signal averaging. This finding implies that the optimal k‐space volume to be sampled or the optimal scan time in MRI should be matched to the relative SNR level. Magn Reson Med 48:550–554, 2002. © 2002 Wiley‐Liss, Inc.
Fluorine electron double resonance imaging for 19F MRI in low magnetic fields
Authors: Murugesan Ramachandran , English Sean , Reijnders Koen , Yamada Ken‐ichi , Cook John A. , Mitchell James B. , Subramanian Sankaran , Krishna Murali C.
Published: September 2002

This work demonstrates the feasibility of generating fluorine NMR images at a very low magnetic field of 0.015 T by making use of the Overhauser enhancement of 19F NMR signal brought about by a stable, water‐soluble, narrow‐line paramagnetic contrast agent. The enhancement in the 19F NMR images depends on the concentration of the single electron contrast agent, the pO2, and the electron paramagnetic resonance (EPR) irradiation power. The applicability of this technique for 19F NMR imaging is demonstrated with phantom samples, where a time resolution of 4–10 min is achieved. Proton electron double resonance imaging (PEDRI) and fluorine electron double resonance imaging (FEDRI) images were also obtained from rat kidneys ex vivo, perfused with 10 mM Oxo63 and 10 M trifluoroacetic acid. The spatial and temporal resolutions of these images are comparable to those obtained at magnetic fields 2–3 orders of magnitude larger. Constant NMR frequency (628 kHz) operation permits both FEDRI and PEDRI of identical slices without removing the object under investigation. This feasibility of coregistration of proton‐based anatomical PEDRI image with physiological FEDRI image offers good potential for studying fluorine‐containing tracers. Magn Reson Med 48:523–529, 2002. Published 2002 Wiley‐Liss, Inc.
Using UNFOLD to remove artifacts in parallel imaging and in partial‐Fourier imaging
Authors: Madore Bruno
Published: September 2002

In dynamic MRI, it is often difficult to achieve the acquisition speed required to resolve or freeze the temporal variations of the imaged object. Several MRI methods aim at speeding up the image acquisition process. Through assumptions and/or prior knowledge, these dynamic MRI methods allow part of the needed data to be calculated instead of acquired. For example, partial‐Fourier imaging assumes that phase varies smoothly within the object, and parallel imaging (e.g., simultaneous acquisition of spatial harmonics (SMASH) and sensitivity encoding (SENSE)) uses prior knowledge about receiver‐coil sensitivity. While these methods accelerate acquisition, they can introduce artifacts or amplify noise in doing so. The present work aims at accelerating image acquisition significantly, while introducing almost no artifacts or noise amplification. It is shown here that new, extra information is gained if dynamic MRI methods are modified so that the sampling function changes in specific ways from time‐frame to time‐frame. In other words, the set of k‐space locations that are acquired (instead of calculated) changes with time. The present temporal strategy, based on the UNaliasing by Fourier‐encoding the Overlaps in the temporaL Dimension (UNFOLD) method, can be incorporated into common dynamic MRI methods. Results with partial‐Fourier, SMASH, and SENSE imaging are presented here, where UNFOLD's contribution is to very significantly reduce the artifact and/or amplified noise content. Used in this way, UNFOLD contributes indirectly, rather than directly to the improvement in image acquisition speed, as it allows companion methods to operate properly at greater acceleration settings than would otherwise be feasible. Magn Reson Med 48:493–501, 2002. © 2002 Wiley‐Liss, Inc.
Effects of intracellular pH, blood, and tissue oxygen tension on T1ρ relaxation in rat brain
Authors: Kettunen Mikko I. , Gröhn Olli H.J. , Silvennoinen M. Johanna , Penttonen Markku , Kauppinen Risto A.
Published: September 2002

The effects of intracellular pH (pHi), paramagnetic macroscopic, and microscopic susceptibility on T1 in the rotating frame (T1ρ) were studied in rat brain. Intracellular acidosis was induced by hypercapnia and pHi, T1ρ, T2, diffusion, and cerebral blood volume (CBV) were quantified. Taking into account the CBV contribution, a prolongation of parenchymal T1ρ by 4.5% was ascribed to a change in tissue water relaxation caused by a one unit drop in pHi. Blood T1ρ was found to prolong linearly with blood oxygenation saturation (Y). The macroscopic susceptibility contribution to parenchymal T1ρ was assessed both through BOLD and an iron oxide contrast agent, AMI‐227. The T1ρ data from these experiments could be described by intravascular effects with insignificant effects of susceptibility gradients on tissue water. Tissue oxygen tension (PtO2) was manipulated and monitored with microelectrodes to assess its plausible contribution to microscopic susceptibility and relaxation. Parenchymal T1ρ was virtually unaffected by variations in the PtO2, but T1 was shortened in hyperoxia and T2 showed a negative BOLD effect in hypoxia. It is demonstrated that pHi directly modulates tissue T1ρ, possibly through its effect on proton exchange; however, neither BOLD nor PtO2 directly influence tissue T1ρ. The observations are discussed in the light of physicochemical mechanisms contributing to the ischemic T1ρ changes. Magn Reson Med 48:470–477, 2002. © 2002 Wiley‐Liss, Inc.
Cerebral spinal fluid contamination of the measurement of the apparent diffusion coefficient of water in acute stroke
Authors: Latour Lawrence L. , Warach Steven
Published: September 2002

The measurement of the apparent diffusion coefficient (ADC) of water in brains of stroke patients is used in models developed to help distinguish reversible from irreversible ischemic injury. The ADC by conventional methods may be overestimated by the presence of cerebral spinal fluid (CSF) in sulci and perivascular spaces. In this study the hypothesis that DWI with CSF suppression (FLAIR‐DWI) would result in different ADC values than those obtained with the conventional DWI technique was investigated. Thirty‐one patients with stroke onset of less than 6 hr and an acute lesion on conventional DWI were studied. Both conventional isotropic DWI and FLAIR‐DWI were performed using a single‐shot echo‐planar technique. In all 31 patients, CSF‐suppressed ADC was lower than conventional ADC. The mean (SD) of the 31 patients' lesion ADC was 0.64 (0.08) × 10−3 mm2 s−1 with FLAIR‐DWI and 0.72 (0.09) × 10−3 mm2 s−1 with conventional DWI (P < 0.001). The overestimation of ADC in conventional DWI corresponded to the percentage of the voxel that contained CSF. Suppression of CSF leads to lesion ADC values that are more homogeneous and more than 15% lower than those obtained with conventional DWI techniques. This suggests that FLAIR‐DWI ADC measurements are more accurate than conventional ADC maps. Magn Reson Med 48:478–486, 2002. Published 2002 Wiley‐Liss, Inc.
Novel methodology for the archiving and interactive reading of clinical magnetic resonance spectroscopic imaging
Authors: Alger Jeffry R. , Frew Andrew J. , Cloughesy Timothy F. , del Vecchio Walter , Villablanca J. Pablo , Curran John G.
Published: September 2002

Archiving clinical magnetic resonance spectroscopic imaging (MRSI) data and presenting the data to specialists (e.g., neuroradiologists, neurosurgeons, neurologists, neuro‐oncologists, and MR scientists) who work in different physical locations is a practical problem of significance. This communication describes a novel solution. The study hypothesis was that it is possible to use widely available distributed computing techniques to create a clinical MRSI user interface addressable from any personal computer with a suitable network connection. A worldwide web MRSI archive and interface system was created that permits the user to interactively view individual MRSI voxel spectra with correlation to MR images and to parametric spectroscopic images. Web browser software (i.e., Netscape and Internet Explorer) permits users in various physical locations to access centrally archived MRSI data using a variety of operating systems and client workstations. The system was used for archiving and displaying more than 1000 clinical MRSI studies performed at the authors' institution. The system also permits MRSI data to be viewed via the Internet from distant locations worldwide. The study illustrates that widely available software operating within highly distributed electronic networks can be used for archiving and interactive reading of large amounts of clinical MRSI data. Magn Reson Med 48:411–418, 2002. © 2002 Wiley‐Liss, Inc.
Simultaneous diffusion MRI measurements from multiple perfused rat hippocampal slices
Authors: Shepherd Timothy M. , Blackband Stephen J. , Wirth Edward D.
Published: September 2002

Rat brain slices provide a controllable tissue model in which to investigate the biophysical basis of diffusion‐weighted magnetic resonance (MR) signal changes observed clinically in nervous tissue after ischemic injury. This study describes a new multislice perfusion chamber that allows for the simultaneous acquisition of diffusion‐weighted MR images from multiple perfused rat hippocampal slices (eight slices in the present study). These images had a signal‐to‐noise ratio (SNR) of 48 ± 3 at b = 8080 s/mm2, which was sufficient to analyze the multicomponent diffusion properties of water in rat hippocampal slices. The tissue water diffusion parameters (ffast = 0.527 ± 0.041, Dfast = 1.268 ± 0.087 × 10–3 mm2/s, and Dslow = 0.060 ± 0.003 × 10–3 mm2/s) were stable for at least 8 hr after slice procurement (ANOVA, P > 0.05), suggesting that it may be possible to study the acute temporal evolution of diffusion changes in multiple brain slices following experimental perturbation. Magn Reson Med 48:565–569, 2002. © 2002 Wiley‐Liss, Inc.
Rapid method for correction of CSF partial volume in quantitative proton MR spectroscopic imaging
Authors: Horská A. , Calhoun V.D. , Bradshaw D.H. , Barker P.B.
Published: September 2002

Partial volume effects with cerebrospinal fluid (CSF), if uncorrected, can lead to underestimation of metabolite concentrations in quantitative proton magnetic resonance spectroscopic imaging (MRSI) of the brain. A rapid method for the correction of CSF partial volume effects is described based on selective CSF imaging using long echo time (TE) fast spin echo (FSE) magnetic resonance imaging (MRI). In order to achieve maximum suppression of signal from brain parenchyma, the FSE sequence is coupled with an inversion recovery (IR) pulse. Scan time is minimized using single shot (SS) IR‐FSE. The method is validated against a current “gold standard” for the determination of CSF volumes, namely, segmented 3D spoiled gradient‐echo (SPGR) scans. Excellent agreement in CSF percentage determined by the two methods was found (linear regression analysis: slope = 0.99 ± 0.02, intercept = 2.08 ± 0.45; mean ± standard errors, R = 0.93) in pooled data from four healthy subjects. An example of the use of SS‐IR‐FSE for partial volume correction in a leukodystrophy patient with T2 hyperintense lesions is demonstrated. SS‐IR‐FSE is a simple and rapid method for applying partial volume corrections in quantitative proton MRSI, which may be of particular value in the clinical environment when time constraints do not allow longer, perhaps more accurate segmentation methods to be used. Magn Reson Med 48:555–558, 2002. © 2002 Wiley‐Liss, Inc.
Time‐resolved, undersampled projection reconstruction imaging for high‐resolution CE‐MRA of the distal runoff vessels
Authors: Du J. , Carroll T.J. , Wagner H.J. , Vigen K. , Fain S.B. , Block W.F. , Korosec F.R. , Grist T.M. , Mistretta C.A.
Published: September 2002

Imaging of the blood vessels below the knee using contrast‐enhanced (CE) MRI is challenging due to the need to coordinate image acquisition and arrival of the contrast in the targeted vessels. Time‐resolved acquisitions have been successful in consistently capturing images of the arterial phase of the bolus of contrast agent in the distal extremities. Although time‐resolved exams are robust in this respect, higher spatial resolution for the depiction of tight stenoses and the small vessels in the lower leg is desirable. A modification to a high‐spatial‐resolution T1‐weighted pulse sequence (projection reconstruction‐time resolved imaging of contrast kinetics (PR‐TRICKS)) that improves the through‐plane spatial resolution by a factor of 2 and maintains a high frame rate is presented. The undersampled PR‐TRICKS pulse sequence has been modified to double the spatial resolution in the slice direction by acquiring high‐spatial‐frequency slice data only after first pass of the bolus of contrast agent. The acquisition reported in the present work (PR‐hyperTRICKS) has been used to image healthy volunteers and patients with known vascular disease. The temporal resolution was found to be beneficial in capturing arterial phase images in the presence of asymmetric filling of vessels. Magn Reson Med 48:516–522, 2002. © 2002 Wiley‐Liss, Inc.
In vivo monitoring of hepatic glutathione in anesthetized rats by 13C NMR
Authors: Macdonald Jeffrey M. , Schmidlin Olga , James Thomas L.
Published: September 2002

A method for in vivo 13C NMR monitoring of hepatic glutathione (GSH) in intact, anesthetized rats has been developed. Studies were conducted using a triple‐tuned, surgically implanted surface coil designed for this animal model. The coil permitted complete decoupling and sufficient resolution in the 13C NMR spectrum to monitor the time course of hepatic 13C‐metabolites of intravenously administered 2‐13C‐glycine, particularly GSH at 44.2 ppm and serine signals at 61.1 and 57.2 ppm, respectively. It further allowed concomitant monitoring of high‐energy phosphagens and intracellular pH by 31P NMR. To confirm in vivo NMR peak assignments, we compared high‐resolution 2D 1H{13C} heteronuclear multiple quantum coherence and 1D 13C spectra of hepatic perchloric acid extracts to those of authentic standards. The fractional isotopic enrichment of hepatic 13C‐glycine increased exponentially at a rate of 1.68 h−1 and reached its plateau level of 81% in 2 h. The 13C fractional isotopic enrichment of GSH increased exponentially at a rate of 0.316 h−1 and reached 55% after 4 h of 2‐13C‐glycine infusion, but without achieving a plateau. To confirm that the resonance at 44.2 ppm resulted from GSH, a rat was given an intravenous dose of 2‐oxothiazolidine‐4‐carboxylic acid (OTC), a cysteine precursor that increases intracellular GSH. As expected, with OTC administration the hepatic 13C GSH‐to‐glycine peak area increased more than sevenfold. Magn Reson Med 48:430–439, 2002. © 2002 Wiley‐Liss, Inc.
Orientational diffusion reflects fiber structure within a voxel
Authors: von dem Hagen Elisabeth A.H. , Henkelman R. Mark
Published: September 2002

Several new MR techniques have been introduced to infer direction through diffusion in multiple nerve fiber bundles within a voxel. To date, however, there has been no physical model reported to evaluate these methodologies and their ability to determine fiber orientation. In this article a model of diffusion analogous to nerve fibers is presented. Diffusion measurements at multiple closely spaced angles of 15° in samples with different fiber orientations are compared with theoretical calculations for restricted diffusion in cylindrical geometry. Orientational diffusion measurements are shown to reflect fiber geometry and theoretical predictions to within 10%. Simulations of fiber crossings within a voxel suggest fiber orientation does not correspond to the direction of the largest measured diffusion coefficient, but theoretical knowledge of signal decay curves can predict the shape of these diffusion coefficient contours for given fiber orientation probabilities. Magn Reson Med 48:454–459, 2002. © 2002 Wiley‐Liss, Inc.
Neuronal control and monitoring of initiation of movements
Authors: Stuphorn Veit , Schall Jeffrey D.
Published: September 2002

The prerequisite for behavioral self‐control is the ability to initiate actions and to cancel planned actions. A rational choice about which action to initiate or to withhold must be informed by the consequences of prior actions. The neuronal correlates of these processes have been studied with the countermanding paradigm. This task requires subjects to withhold planned movements in response to an imperative stop signal, which they can do with varying success. By recording the activity of single neurons in different parts of the frontal cortex of macaque monkeys performing this task, signals that are sufficient for controlling the initiation and inhibition of movements and other signals that evaluate the consequences of these movements have been identified. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 326–339, 2002
Malignant MCLeod myopathy
Authors: Jung Hans H. , Brandner Sebastian
Published: September 2002

Mild myopathy is a common manifestation of the X‐linked McLeod neuroacanthocytosis syndrome. We present a patient with McLeod syndrome and a primarily subclinical myopathy, who developed severe rhabdomyolysis with renal insufficiency after a prolonged period of excessive motor restlessness due to an agitated psychotic state and a single dose of clozapine. Other possible causes for rhabdomyolysis such as prolonged immobility, trauma, hyperthermia, generalized seizures, toxin exposure, or metabolic changes were excluded. Clinical course was favorable, with persistent slight elevation of serum creatine kinase levels caused by the underlying myopathy. Our findings suggest that McLeod myopathy is a predisposing factor for severe rhabdomyolysis. This possibly life‐threatening condition should be added to the clinical spectrum of McLeod syndrome, and serum creatine kinase levels should be carefully monitored in patients with this syndrome, particularly if a hyperkinetic movement disorder is present or neuroleptic medication is used. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 424–427, 2002
Sensory‐predominant, painful, idiopathic neuropathy: Inflammatory changes in sural nerves
Authors: Kelkar Praful , McDermott Wendy R. , Parry Gareth J.
Published: September 2002

Sensory‐predominant, painful, idiopathic neuropathies are a common clinical problem. In this retrospective study of 11 patients with such a neuropathy, we found axonal loss in 9, with multifocal axonal loss in 4 patients; there were large perivascular mononuclear inflammatory infiltrates (>50 cells) in 4 and smaller infiltrates (10–20 cells) in 4. These findings suggest that some cases of this neuropathy may be due to autoimmune vasculopathy and therefore may respond to immunotherapy. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 413–416, 2002
Refinements in nerve to muscle neurotization
Authors: Becker Michael , Lassner Franz , Fansa Hisham , Mawrin Christian , Pallua Norbert
Published: September 2002

A modified surgical technique is introduced, enabling restoration of muscle function with direct muscular neurotization. Reliable clinical outcomes result from this technique. We report on a series of 10 patients in whom the supplying motor nerve had been lost at the level of the neuromuscular junction as the result of trauma or tumor resection. Our modification of the operative technique ensures a wide distribution of nerve fibers throughout the remaining muscle tissue and produces a mean motor recovery of M4 after a period of 1 to 2 years. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 362–366 2002
Predictive power of motor unit potential parameters in anal sphincter electromyography
Authors: Podnar Simon , Mrkaić Mićo
Published: September 2002

The diagnostic utility of motor unit potential (MUP) parameters is usually based exclusively on their diagnostic sensitivity, disregarding specificity. In the present study, advanced statistical methods were used to determine MUP parameters with the highest predictive power for the separation of neuropathic and normal external anal sphincter (EAS) muscles. Using multi‐MUP analysis, 3,720 MUPs from 138 muscles of 52 patients with cauda equina lesion and 2,526 from 112 muscles of 64 controls were obtained. Only two principal components (PCs), which put weight on the MUP area and amplitude, were needed to explain all the data variability. On logistic and probit regression analyses, MUP area, duration, and number of turns gave results identical to all MUP parameters. Our results suggest that only these three MUP parameters are needed, and that they are as effective as PCs, in MUP analysis of chronic neuropathic EAS muscles. Reduced number of MUP parameters is expected to simplify MUP analysis and increase its specificity. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 389–394, 2002
Ultrasound therapy facilitates the recovery of acute pressure‐induced conduction block of the median nerve in rabbits
Authors: Paik Nam‐Jong , Cho Soo‐Hun , Han Tai Ryoon
Published: September 2002

Though the use of ultrasound for the treatment of carpal tunnel syndrome (CTS) or compression neuropathy has been described, its effect remains controversial. A test model of acute CTS was developed using rabbits. Acute median nerve compression was induced by the infusion of saline into the carpal tunnel under general anesthesia to elevate the intracarpal pressure. A reduction in the compound muscle action potential (CMAP) amplitude of the abductor pollicis was noted after intracarpal pressure increased. To investigate the efficacy of ultrasound in acute CTS, rabbits with acute median nerve compression were divided into 3 groups (10 each) and ultrasound was applied at different intensities to each group as follows: 1.5 W/cm2 to group 1; 0.2 W/cm2 to group 2; 0.0 W/cm2 (sham) to group 3. A total of 10 treatment sessions were given over a period of 2 weeks. Following ultrasound application, the CMAP amplitudes showed significant improvement in group 1 compared to the other two groups (P < 0.05), indicating facilitated recovery from acute CTS in this pressure‐induced median nerve compression rabbit model. The benefits of ultrasound application in a clinical setting must be verified by further clinical trials. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 356–361, 2002
MMG and EMG responses during fatiguing isokinetic muscle contractions at different velocities
Authors: Perry‐Rana Sharon R. , Housh Terry J. , Johnson Glen O. , Bull Anthony J. , Berning Joseph M. , Cramer Joel T.
Published: September 2002

The purpose of this study was to determine mechanomyographic (MMG) and electromyographic (EMG) responses of the superficial quadriceps muscles during repeated isokinetic contractions in order to provide information about motor control strategies during such activity, and to assess uniformity in mechanical activity (MMG) between the investigated muscles. Ten adults performed 50 maximal concentric muscle contractions at three randomly selected contraction velocities (60, 180, and 300°·s−1) on different days. Surface electrodes and an MMG sensor were placed on the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM). EMG and MMG amplitude and peak torque (PT) were calculated for each contraction, normalized, and averaged across all subjects. The results demonstrated that MMG amplitude more closely tracked the fatigue‐induced decline in torque production at each velocity than did EMG amplitude. This indicates that MMG amplitude may be useful for estimating force production during fatiguing dynamic contractions when a direct measure is not available, such as during certain rehabilitative exercises. MMG amplitude responses of the VL, RF, and VM were not uniform for each velocity or across velocities, indicating that it may be possible to detect the individual contribution of each muscle to force production during repeated dynamic contractions. Therefore, MMG amplitude may be clinically useful for detecting abnormal force contributions of individual muscles during dynamic contractions, and determining whether various treatments are successful at correcting such abnormalities. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 367–373, 2002
Intrapartum maternal lumbosacral plexopathy
Authors: Katirji Bashar , Wilbourn Asa J. , Scarberry Susan L. , Preston David C.
Published: September 2002

There are many conflicting theories regarding the mechanism and prognosis of acute foot drop during labor. We report seven women who had arrested labor and foot drop. Six had short stature and one had a large newborn. All had weakness of ankle dorsiflexion, eversion, and inversion, and sensory loss in the L‐5 dermatome. Superficial peroneal sensory nerve action potentials (SNAPs) were small or absent in six patients, and the sural SNAP was attenuated in one. Peroneal compound muscle action potential (CMAP) amplitude (recording from extensor digitorum brevis) was low in five, whereas the tibial CMAP was normal in all patients. Peroneal CMAP amplitude (recording from the tibialis anterior) was normal in three and small in three. Needle electromyography revealed decreased recruitment and fibrillation potentials in L‐5–innervated muscles, mostly below the knee. We conclude that intrapartum foot drop occurs mostly in short women and is caused by lumbosacral trunk compression by the fetal head at the pelvic brim. The primary pathology is predominantly demyelination and recovery is complete in up to 5 months. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 340–347; 2002
The medial antebrachial cutaneous nerve: Antidromic and orthodromic conduction studies
Authors: Seror Paul
Published: September 2002

Medial antebrachial cutaneous nerve (MABCN) conduction studies were performed antidromically and orthodromically in 70 control subjects to determine normal values and define the lower limits of normality. The mean sensory action potential (SAP) amplitudes were 17.7 and 17.5 μV and the sensory conduction velocities were 60 and 61 m/s, respectively, with the antidromic and orthodromic techniques. With both techniques, no SAP amplitude was lower than 6 μV. The lower limits of normal of the interside amplitude ratio were 1.66 when both techniques were used and 2.0 when only one was used. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 421–423, 2002