bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐pool model of white matter
Authors: Lancaster Jack L. , Andrews Trevor , Hardies L. Jean , Dodd Stephen , Fox Peter T. 
Published: December 2002

AbstractPurposeTo investigate the use of a three‐pool relaxation model to measure myelin, myelinated‐axon, and mixed water‐pool fractions in white matter (WM) during myelination.Materials and MethodsMRI at 1.9 Tesla, and conventional spin‐echo imaging were used to acquire T1 and T2 relaxation data in 15 normal children ranging in age from 3 months to 13 years 4 months. Three equations with three unknowns were solved to calculate three water‐pool fractions for each child in a frontal association‐fiber area and a frontal‐parietal projection‐fiber area. The temporal trend of the fractions was compared with a theoretical three‐pool myelination model.ResultsThe myelin level in the projection‐fiber area rose earlier than in the association‐fiber area following the standard caudal‐to‐rostral trend. The temporal trend of the three‐pool fractions followed that predicted by the theoretical myelination model in both brain areas. The myelinated‐axon and mixed pool sizes were significantly different in the two WM areas following early myelination, although their myelin pools were similar. T1 values correlated more highly with the myelinated‐axon and mixed pool fractions than with the myelin pool fraction.ConclusionThe three‐pool relaxation model provides measurements of water‐pool fractions in WM that follow values predicted during myelination. J. Magn. Reson. Imaging 2003;17:1–10. © 2002 Wiley‐Liss, Inc.
Is myo‐inositol a measure of glial swelling after stroke? a magnetic resonance study
Authors: Rumpel Helmut , Lim Winston Eng Hoe , Chang Hui Meng , Chan Ling Ling , Ho Gaik Lynn , Wong Meng Cheong , Tan Kim Ping 
Published: December 2002

AbstractPurposeTo determine whether the hypothesis that the phenomenon of persistent cytotoxic edema in the subacute stage of ischemic stroke is in fact associated with the glial population. This is done by assessing the evolution of both the apparent diffusion coefficient (ADC) and the glial‐specific marker myo‐inositol (Ins) in a group of patients, and by comparing the results with the total cellular density by means of the creatine (Cre) level.Material and MethodsTwenty‐two patients with stroke in the territory of the middle cerebral artery were each examined once only at a time ranging from eight hours to six days following the onset of symptoms. Lesion‐to‐contralateral values of ADC were obtained based on diffusion‐weighted echo‐planar imaging. Short TE single‐voxel proton magnetic resonance (1H MR) spectroscopy was used for quantification of cerebral metabolites in infarcted regions. Their levels were also compared with those in homotopic contralateral regions.ResultsIn the stroke lesion, there was a significant correlation between ADC and the Ins level, albeit less pronounced than that for Cre. During different pathophysiological stages between 12 hours and three days, the Ins‐to‐Cre ratio increased by a factor of two and returned to apparently normal thereafter.ConclusionOur study provides the first demonstration of a relationship between persistent cytotoxic edema and the glial population in the context of cell swelling due to osmotic imbalance in stroke patients. J. Magn. Reson. Imaging 2003;17:11–19. © 2002 Wiley‐Liss, Inc.
Knees of ironman triathletes: Magnetic resonance imaging assessment of older (>35 years old) competitors
Authors: Shellock Frank G. , Hiller W. Douglas B. , Ainge George R. , Brown David W. , Dierenfield Laura 
Published: December 2002

AbstractPurposeTo use magnetic resonance imaging (MRI) to evaluate the knees of older (>35 years old), competitive Ironman triathletes to determine the prevalence of abnormal findings.Materials and MethodsThe knees of 29 Ironman triathletes (20 men, 9 women; age range, 35–66 years old) were studied by MRI. The findings were analyzed collectively and categorized into group I (N = 13), subjects without prior knee injuries and symptoms, and group II (N = 16), subjects with prior knee injuries and/or current symptoms.ResultsTen percent of the knees had ligamentous abnormalities, but the prevalence was not statistically different comparing group I to group II. Fifty‐five percent had abnormal menisci. The overall prevalence of abnormal menisci was significantly higher in group II (69%) than in group I (38%, P < 0.05). Cartilage abnormalities were found in 21% of the triathletes with a higher prevalence in group II (31%) than in group I (8%, P < 0.05). Twenty‐one percent (6/29) of the knees had bone contusions, with a higher prevalence in group II (31%) than in group I (8%, P < 0.05).ConclusionIn general, the spectrum of abnormal MRI findings of the knee was no greater than age‐related changes previously reported for other athletic populations and nonathletes. These results have important implications for the diagnostic use of MRI of the knee in this high‐endurance, athletic population. J. Magn. Reson. Imaging 2003;17:122–130. © 2002 Wiley‐Liss, Inc.
Liquid‐phase oxidation of 1‐isopropyl‐ and 1‐ethyl‐4‐methoxybenzenes with oxygen to hydroperoxides
Authors: Zawadiak Jan , Stec Zbigniew , Jakubowski Bartłomiej , Orlińska Beata 
Published: December 2002

AbstractA study was carried out on the kinetics of free‐radical chain oxidation of 1‐isopropyl‐4‐methoxybenzene (1a) and 1‐ethyl‐4‐methoxybenzene (1b) with oxygen in the liquid phase to yield 1‐methyl‐1‐(4‐methoxyphenyl)ethyl hydroperoxide (2a) and 1‐(4‐methoxyphenyl)ethyl hydroperoxide (2b). The oxidizability of 1a and 1b was studied over the temperature range 50–100°C. Long‐term oxidations of 1a and 1b to the corresponding hydroperoxides were carried out and the properties and thermal stability of 2a were established. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 89–94, 2003
Abnormal angiogenesis in diabetes mellitus
Authors: Martin Alexandra , Komada Michael R. , Sane David C. 
Published: December 2002

AbstractThe adverse long‐term effects of diabetes mellitus have been well described and involve many organ systems. While diabetes management has largely focused on control of hyperglycemia, the presence of abnormalities of angiogenesis may cause or contribute to many of the clinical manifestations of diabetes. When compared with non‐diabetic subjects, diabetics demonstrate vascular abnormalities of the retina, kidneys, and fetus. Diabetics have impaired wound healing, increased risk of rejection of transplanted organs, and impaired formation of coronary collaterals. In each of these conditions, and possibly in diabetic neuropathy as well, abnormalities of angiogenesis can be implicated in the pathogenesis. A perplexing feature of the aberrant angiogenesis is that excessive and insufficient angiogenesis can occur in different organs in the same individual. In this review, the clinical features, molecular mechanisms, and potential therapeutic options of abnormal angiogenesis in diabetes will be reviewed. © 2002 Wiley Periodicals, Inc. Med Res Rev, 23, No. 2, 117–145, 2003
Carbonic anhydrase inhibitors
Authors: Supuran Claudiu T. , Scozzafava Andrea , Casini Angela 
Published: December 2002

AbstractAt least 14 different carbonic anhydrase (CA, EC 4.2.1.1) isoforms were isolated in higher vertebrates, where these zinc enzymes play crucial physiological roles. Some of these isozymes are cytosolic (CA I, CA II, CA III, CA VII), others are membrane‐bound (CA IV, CA IX, CA XII, and CA XIV), CA V is mitochondrial and CA VI is secreted in saliva. Three acatalytic forms are also known, which are denominated CA related proteins (CARP), CARP VIII, CARP X, and CARP XI. Several important physiological and physio‐pathological functions are played by many CA isozymes, which are strongly inhibited by aromatic and heterocyclic sulfonamides as well as inorganic, metal complexing anions. The catalytic and inhibition mechanisms of these enzymes are understood in detail, and this helped the design of potent inhibitors, some of which possess important clinical applications. The use of such enzyme inhibitors as antiglaucoma drugs will be discussed in detail, together with the recent developments that led to isozyme‐specific and organ‐selective inhibitors. A recent discovery is connected with the involvement of CAs and their sulfonamide inhibitors in cancer: several potent sulfonamide inhibitors inhibited the growth of a multitude of tumor cells in vitro and in vivo, thus constituting interesting leads for developing novel antitumor therapies. Furthermore, some other classes of compounds that interact with CAs have recently been discovered, some of which possess modified sulfonamide or hydroxamate moieties. Some sulfonamides have also applications as diagnostic tools, in PET and MRI or as antiepileptics or for the treatment of other neurological disorders. Future prospects for drug design applications for inhibitors of these ubiquitous enzymes are also discussed. © 2002 Wiley Periodicals, Inc. Med Res Rev, 23, No. 2, 146–189, 2003
Marine pyridoacridine alkaloids and synthetic analogues as antitumor agents
Authors: Delfourne Evelyne , Bastide Jean 
Published: December 2002

AbstractPyrido[4,3,2‐mn]acridines are of major interest as metabolites in sponges and ascidians. During the last few years, numerous additional compounds of this family were isolated, some of them being polycyclic structures already reported with different substituents (shermilamine or kuanoniamine‐derivatives), others, such as neoamphimedine, arnoamines and styelsamines having original structures. The synthesis of these compounds and analogues have been performed in order to allow their biological evaluation. In most of the cases, the cytotoxicity of analogues was improved compared to the natural product, specially in ascididemin or meridine series. The pyridoacridines have not a sole mode of action, but it seems that the reductive DNA cleavage mediated by reactive oxygen species is a potential general mode of action. © 2002 Wiley Periodicals, Inc. Med Res Rev, 23, No. 2, 234–252, 2003
Design of a new suture practice card for microsurgical training
Authors: Usón Jesús , Carmen Calles M. 
Published: December 2002

AbstractSuturing technique is of paramount importance in microsurgery. Basic training in this technique can be done using the practice card, a purpose‐made polyurethane card. A practice card has been designed in the Minimally Invasive Surgery Centre to closely resemble microsurgical requirements in order to practice and learn correct microsuturing maneuvers. This practice card is a key part of microsurgical training. After many years of experience, and based on a survey we conducted, we can conclude that this practice card is essential for step‐by‐step microsurgical training. Using this card, the number of animals required to attain necessary microsurgical skills is reduced significantly. Furthermore, costs are also reduced, and the trainee can avoid mistakes during training with live animals, thus optimizing results. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:324–328 2002
Auxiliary partial liver grafting in rats: Effect of host hepatectomy on graft regeneration, and review of literature on surgical technique
Authors: Wang Jun , Tahara Kazunori , Hakamata Yoji , Mutoh Hiroyuki , Murakami Takashi , Takahashi Masafumi , Kusama Mikio , Kobayashi Eiji 
Published: December 2002

AbstractAuxiliary partial liver transplantation (APLT) is beneficial for fulminant liver failure when there is potential for recovery of the diseased liver. However, the impact of host hepatectomy on regeneration of the grafted liver is unclear. In this study, we modified a previous rat model of auxiliary whole liver transplantation without portal vein reconstruction, and studied the effect of host hepatectomy on regeneration of the cut liver graft. Thirty percent of the liver was heterotopically transplanted, to connect the recipient's left renal artery and vein with the graft's aortic cuff of the hepatic artery and inferior vena cava, respectively, using a cuff technique; 30% of the recipient liver then was cut. The control group was left intact. The liver grafts were weighed preoperatively and 2 weeks postoperatively. This procedure prevented congestion of the graft liver and achieved a high success rate, even when performed by a surgeon who was relatively inexperienced with the technique. The weight of the grafted liver in the host hepatectomized group significantly increased (P < 0.05) compared with that of the control group. We developed an experimental model of APLT and reviewed the literature on rat heterotopic liver transplantation, and compared the surgical techniques. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:371–377 2002
Protective effects of immunosuppressants and steroids against ischemia‐reperfusion injury in cremaster muscle flap at microcirculatory level
Authors: Askar Ibrahi̇m , Bozkurt Mehmet 
Published: December 2002

AbstractThe sequential events between leukocytes and endothelium have significant implications in surgical procedures, trauma, vascular injury, and wound healing. These sequential events are mediated by free oxygen radicals, leukocytes, red blood cells, and endothelial cells. In this study, we investigated the protective effects of steroids and immunosuppressants against ischemia‐reperfusion injury in cremaster muscle flaps at the microcirculatory level. In this experimental study, 50 male Sprague‐Dawley rats, weighing about 120–130 g, were used. The rats were divided into five groups of 10 rats each: the control group (group 1, n = 10), methyl prednisolone group (group 2, n = 10), dexamethasone group (group 3, n = 10), cyclosporin A group (group 4, n = 10), and azathioprine (group 5, n = 10). Surgical procedures were divided into two stages. In the first stage, a cremaster muscle end‐organ tube flap was created by extracting the testes and spermatic cord. The flap was placed into a subcutaneous tunnel in the anteromedial aspect of the ipsilateral limb. In the experimental groups, ischemia was performed by clamping the femoral artery and vein above and below the cremaster pedicle for 4 h. Then the clamps were removed, and perfusion of the cremaster muscle was allowed for 24 h. In the second stage, a round flap was obtained from the cremaster muscle tube‐flap to evaluate microcirculation after 24 h of reperfusion, and dissected along its front wall using cauterization. Vessel diameter, red blood cell velocities, leukocyte activation, perfused capillaries, and endothelial edema index were measured and evaluated statistically. There was a significant decrease in the number of rolling, sticking, and transmigrating neutrophils of groups 2 (cyclosporin A), 4 (methylprednisolone), and 3 (azathioprine) (P < 0.05), whereas those of group 5 (dexamethasone) were not decreased (P > 0.05). There was a significant increase in the number of perfused capillaries of groups 2 (cyclosporin A), 4 (methylprednisolone), and 3 (azathioprine) (P < 0.05), nearly 0.75‐, 0.5‐, and 0.75‐fold, respectively. We conclude that cyclosporin and azathioprine showed a protective effect on muscle tissue against ischemia‐reperfusion injury by inhibiting leukocyte infiltration, and that methylprednisolone had a beneficial effect against ischemia‐reperfusion injury by reducing the synthesis of eicosanoids, edema formation, and leukocyte infiltration. However, we believe that dexamethasone might have a salutary effect due to reducing the synthesis of eicosanoids, edema formation, and release of free oxygen radicals, but not due to leukocyte infiltration. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:361–366 2002
Rapid neurorrhaphy with titanium clips
Authors: Park Jong Woong , Lee Kwang Suk , Kim Sung Kon , Park Jung Ho , Hong Jun Seok , Oh Kwang Jun 
Published: December 2002

AbstractThe purpose of this study was to evaluate the usefulness of titanium clips in the repair of transected peripheral nerves. The results of neurorrhaphy using titanium clips (VCS) were compared with the conventional technique of neurorrhaphy using nylon sutures. Transected sciatic nerves in 15 New Zealand white rabbits were repaired with VCS clips on one side and interrupted 9‐0 nylon sutures on the other. The average time required for neurorrhaphy using the clip closure was 8.7 ± 2.6 min, and this was shorter than the suture closure, which took 14.9 ± 3.6 min (P < 0.01). Electromyographic studies revealed no significant differences in amplitudes of compound motor action potentials in both groups. Also, the number and extent of myelinizations of regenerated axons were not significantly different in both methods of nerorrhaphies. These results demonstrate that microscopic neurorrhaphy using titanium clips is a potential alternative to conventional neurorrhaphy using sutures. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:386–390 2002
Effect of reduced impulse activity on the development of identified motor terminals in Drosophila larvae
Authors: Lnenicka Gregory A. , Spencer Gregory M. , Keshishian Haig 
Published: December 2002

AbstractIn Drosophila larvae, motoneurons show distinctive differences in the size of their synaptic boutons; that is, axon 1 has type Ib (“big” boutons) terminals and axon 2 has type Is (“small” boutons) terminals on muscle fibers 6 and 7. To determine whether axon 1 develops large boutons due to its high impulse activity, we reduced impulse activity and examined the motor terminals formed by axon 1. The number of functional Na+ channels was reduced either with the napts mutation or by adding tetrodotoxin (TTX) to the media (0.1 μg/g). In both cases, the rate of locomotion was decreased by approximately 40%, presumably reflecting a decrease in impulse activity. Locomotor activity was restored to above wild‐type (Canton‐S) levels when napts was combined with a duplication of para, the Na+‐channel gene. Lucifer yellow was injected into the axon 1 motor terminals, and we measured motor terminal area, length, the number of branches, and the number and width of synaptic boutons. Although all parameters were smaller in napts and TTX‐treated larvae compared to wild‐type, most of these differences were not significant when the differences in muscle fiber size were factored out. Only bouton width was significantly smaller in both different napts and TTX‐treated larvae: boutons were about 20% smaller in napts and TTX‐treated larvae, and 20% larger in napts; Dp para+ compared to wild‐type. In addition, terminal area was significantly smaller in napts compared to wild‐type. Bouton size at Ib terminals with reduced impulse activity was similar to that normally seen at Is terminals. Thus, differences in impulse activity play a major role in the differentiation of bouton size at Drosophila motor terminals. © 2002 Wiley Periodicals, Inc. J Neurobiol 54: 337–345, 2003
Lithium inhibits a late step in agrin‐induced AChR aggregation
Authors: Sharma S. K. , Wallace B. G. 
Published: December 2002

AbstractAgrin activates an intracellular signaling pathway to induce the formation of postsynaptic specializations on muscle fibers. In myotubes in culture, this pathway has been shown to include autophosphorylation of the muscle‐specific kinase MuSK, activation of Src‐family kinases, tyrosine phosphorylation of the acetylcholine receptor (AChR) β subunit, a decrease in receptor detergent extractability, and the accumulation of AChRs into high‐density aggregates. Here we report that treating chick myotubes with lithium prevented any detectable agrin‐induced change in AChR distribution without affecting the number of AChRs or the agrin‐induced change in AChR tyrosine phosphorylation and detergent extractability. Lithium treatment also increased the rate at which AChR aggregates disappeared when agrin was removed. The effects of lithium developed slowly over the course of approximately 12 h. Thus, sensitivity to lithium identifies a late step in the agrin signaling pathway, after agrin‐induced MuSK and AChR phosphorylation, that is necessary for the recruitment of AChRs into visible aggregates. © 2002 Wiley Periodicals, Inc. J Neurobiol 54: 346–357, 2003
Serotonin in the developing stomatogastric system of the lobster, Homarus americanus
Authors: Richards Kathryn S. , Simon David J. , Pulver Stefan R. , Beltz Barbara S. , Marder Eve 
Published: December 2002

AbstractWe studied the development of the serotonergic modulation of the stomatogastric nervous system of the lobster, Homarus americanus. Although the stomatogastric ganglion (STG) is present early in embryonic development, serotonin immunoreactivity is not visible in the STG until the second larval stage. However, incubation of the STG with exogenous serotonin showed that a serotonin transporter is present in embryonic and early larval stages. Serotonin uptake was blocked by paroxetine and 0% Na+ saline. The presence of a serotonin transporter in the embryonic STG suggests that hormonally liberated serotonin could be taken up by the STG, and potentially released as a “borrowed transmitter”. Consistent with a potential hormonal role, serotonin is found in the pericardial organs, a major neurosecretory structure, by midembryonic development. The rhythmic motor patterns produced by embryonic and larval STGs were decreased in frequency by serotonin. Lateral Pyloric (LP) neuron‐evoked excitatory junctional potentials (EJPs) in the embryos and the first larval stage (LI) were larger, slower, and more variable than those in the adult. The amplitude of adult LP neuron‐evoked EJPs was increased more than twofold in serotonin, but in embryos and LI preparations this effect was negligible. In embryos and LI preparations, serotonin increased the occurrence of muscle fiber action potentials and altered the EJP wave‐form. These data demonstrate that serotonin receptors are present in the stomatogastric nervous system early in development, and suggest that the role of serotonin changes from modulation of muscle fiber excitability early in development to enhancement of neurally evoked EJPs in the adult. © 2002 Wiley Periodicals, Inc. J Neurobiol 54: 380–392, 2003
Biogenic amines in the antennal lobes and the initiation and maintenance of foraging behavior in honey bees
Authors: Schulz David J. , Elekonich Michelle M. , Robinson Gene E. 
Published: December 2002

AbstractPrevious findings showed that high levels of octopamine and serotonin in the antennal lobes of adult worker honey bees are associated with foraging behavior, and octopamine treatment induces precocious foraging. To better characterize the relationship between amines and foraging behavior in honey bees, we performed a detailed correlative analysis of amine levels in the antennal lobes as a function of various aspects of foraging behavior. Flight activity was measured under controlled conditions in a large outdoor flight cage. Levels of octopamine in the antennal lobes were found to be elevated immediately subsequent to the onset of foraging, but they did not change as a consequence of preforaging orientation flight activity, diurnal pauses in foraging, or different amounts of foraging experience, suggesting that octopamine helps to trigger and maintain the foraging behavioral state. In contrast, levels of serotonin and dopamine did not show changes that would implicate them as either causal agents of foraging, or as neurochemical systems affected by the act of foraging. Serotonin treatment had no effect on the likelihood of foraging. These results provide further support for the hypothesis that an increase in octopamine levels in the antennal lobes plays a causal role in the initiation and maintenance of the behavioral state of foraging, and thus is involved in the regulation of division of labor in honey bees. © 2002 Wiley Periodicals, Inc. J Neurobiol 54: 406–416, 2003