bluuebunny/crossref_metadata_2025 huggingface dataset:
Soft tissue sarcoma of the upper extremity
Authors: Lohman Robert F. , Nabawi Ayman S. , Reece Gregory P. , Pollock Raphael E. , Evans Gregory R. D.
Published: August 2002

BACKGROUND

The objective of this study was to define the impact of soft tissue flap reconstruction on multimodality therapy for patients with soft tissue sarcomas of the upper extremity. Treatment standards continue to evolve for these patients, and, with multimodality therapy, most of them are candidates for limb‐preserving surgery. Consequently, the role of soft tissue flap reconstruction is expanding.

METHODS

A review was conducted of 100 consecutive patients with soft tissue sarcomas of the upper extremity who underwent surgery at several institutions between 1992 and 1997.

RESULTS

Seventy‐one patients underwent direct closure of defects after tumor resection, and 29 patients required soft tissue reconstruction with flaps. These groups were similar in most respects, except that 52% of the patients who required soft tissue reconstruction presented with recurrent disease (P = 0.0004), and 79% of them had tumors measuring > 5 cm in greatest dimension (P = 0.0003). The patients who required flap reconstruction had larger skin deficits after undergoing tumor resection (140 cm2) compared with the patients who had wounds that were managed by direct closure (40 cm2; P < 0.00001). Margins around the resected tumors were larger (1.62 cm) when flaps were employed compared with margins when defects were closed directly (0.87 cm; P = 0.0005). However, the number of patients with intralesional, marginal, wide, and radical resections was the same regardless of wound management. Major complications occurred in 14% of patients, but none led to death or amputation. The median follow‐up was 31 months, and 66% of patients had no evidence of disease at that time. Rates of local recurrence and survival were similar for patients who underwent flap reconstruction compared with patients who underwent direct closure.

CONCLUSIONS

Soft tissue flap reconstruction facilitates therapy for patients with soft tissue sarcomas of the upper extremity, so that patients with larger tumors can undergo resection, limiting complications and limb sacrifice. Cancer 2002;94:2256–64. © 2002 American Cancer Society.

DOI 10.1002/cncr.10419
Physiological and morphological diversity of immunocytochemically defined parvalbumin‐ and cholecystokinin‐positive interneurones in CA1 of the adult rat hippocampus
Authors: Pawelzik Hannelore , Hughes David I. , Thomson Alex M.
Published: August 2002

To investigate the electrophysiological properties, synaptic connections, and anatomy of individual parvalbumin‐immunoreactive (PV‐IR) and cholecystokinin‐immunoreactive (CCK‐IR) interneurones in CA1, dual intracellular recordings using biocytin‐filled microelectrodes in slices of adult rat hippocampus were combined with fluorescence labelling of PV‐ and CCK‐containing cells. Of 36 PV‐IR cells, 29 were basket cells, with most of their axonal arbours in the stratum pyramidale (SP). Six were bistratified cells with axons ramifying throughout stratum oriens (SO) and stratum radiatum (SR). One was a putative axo‐axonic cell with an axonal arbour confined to half of the SP and a narrow adjacent region of the SO. Of 27 CCK‐IR neurones, 13 were basket cells, with most of their axonal arbours in the SP, and included basket cells with somata in the SP (6), SO (3), and SR (2) and at the border between the stratum lacunosum‐moleculare (SLM) and the SR (2). In addition, several dendrite‐targeting cell classes expressed CCK‐IR: 4 of 9 bistratified cells with axons ramifying in the SO and SR; all five Schaffer‐associated cells whose axons ramified extensively in the SR; both cells classified as quadrilaminar because their axons ramified in the SO, SP, SR, and SLM; one SO‐SO cell whose dendritic and axonal arbours were contained within the SO; and one perforant path‐associated cell with axonal and dendritic arbours within the distal SR and SLM. The majority (31 of 36) of PV‐IR neurones recorded were fast‐spiking, and most fast‐spiking cells tested (25 of 29 basket, 1 axo‐axonic, and 5 of 6 bistratified cells) were PV‐IR. However, 1 of 6 regular‐spiking basket, 1 of 4 regular‐spiking bistratified, and 3 of 5 burst‐firing basket cells were also PV‐IR. In contrast, the majority (17 of 27) of the CCK‐IR neurones recorded were regular‐spiking, 3 were burst‐firing, and 7 were fast‐spiking. These data confirm that the majority of PV‐IR and CCK‐IR axon terminals innervate proximal portions of CA1 pyramidal cells. Most PV‐IR cells are fast‐spiking, whereas most CCK‐IR cells are regular‐spiking. In both neurochemical classes basket cells predominate, but both groups included subpopulations of dendrite‐targeting cells. Despite these similarities, the two populations exhibited very different somatic distributions, and each contained cellular morphologies not represented in the other. J. Comp. Neurol. 443:346–367, 2002. © 2002 Wiley‐Liss, Inc.
Paraventricular nucleus of the human hypothalamus in primary hypertension: Activation of corticotropin‐releasing hormone neurons
Authors: Goncharuk Valeri D. , Van Heerikhuize Joop , Swaab Dick F. , Buijs Ruud M.
Published: August 2002

By using quantitative immunohistochemical and in situ hybridization techniques, we studied corticotropin‐releasing hormone (CRH) ‐producing neurons of the hypothalamic paraventricular nucleus (PVN) in patients who suffered from primary hypertension and died due to acute cardiac failure. The control group consisted of individuals who had normal blood pressure and died of acute heart failure due to mechanical trauma. Both magno‐ and parvocellular populations of CRH neurons appeared to be more numerous in the PVN of hypertensive patients. Quantitative analysis showed approximately a twofold increase in the total number of CRH neurons and a more than fivefold increase in the amount of CRH mRNA in the hypertensive PVN compared with the control. It is suggested that synthesis of CRH in hypertensive PVN is enhanced. Increased activity of CRH‐producing neurons in the PVN of hypertensive patients is proposed not only to entail hyperactivity of the hypothalamo‐pituitary‐adrenal axis, but also of the sympathetic nervous system and, thus, to be involved in the pathogenesis of hypertension. J. Comp. Neurol. 443:321–331, 2002. © 2002 Wiley‐Liss, Inc.
Modulation of responses of feline ventral spinocerebellar tract neurons by monoamines
Authors: Hammar Ingela , Chojnicka Barbara , Jankowska Elzbieta
Published: August 2002

Ventral spinocerebellar tract neurons located in laminae V–VII of cat lumbar spinal cord were tested for the effects of ionophoretically applied monoamines and receptor selective agonists. Extracellularly recorded responses, monosynaptically evoked by group I afferents in a muscle nerve, were compared before, during, and after ionophoresis. They were analyzed with respect to changes in the number of evoked spikes and in the latency. Both serotonin (5‐HT) and noradrenaline (NA) were found to facilitate responses of all neurons tested. Ionophoresis of three serotonin subtype receptor agonists (5‐carboxamidotryptamine maleate, 5 methoxytryptamine HCl, and alpha‐methyl 5‐hydroxytryptamine) and of two NA receptor agonists (phenylephrine and isoproterenol) likewise had a facilitatory effect. However, three other 5‐HT receptor agonists (8‐hydroxy‐dipropylaminotetraline hydrobromide), 2‐methyl 5‐hydroxytryptamine, and 1‐(2,5‐dimethoxy‐4‐iodophenyl)‐2‐aminopropane HCl and two NA receptor agonists (tizanidine and clonidine) had the opposite effect because they depressed responses of the tested neurons. These results show that information forwarded by means of the ventral spinocerebellar tract may be modulated by monoamines and that several receptor subtypes, located pre‐ or postsynaptically, may be involved. The results also demonstrate that transmission by means of group I muscle afferents may not only be facilitated by monoamines but also depressed by selective receptor subtype activation. J. Comp. Neurol. 443:298–309, 2002. © 2002 Wiley‐Liss, Inc.
Axon arbors and synaptic connections of a vulnerable population of interneurons in the dentate gyrus in vivo
Authors: Buckmaster Paul S. , Yamawaki Ruth , Zhang Guo Feng
Published: August 2002

The predominant γ‐aminobutyric acid (GABA)ergic neuron class in the hilus of the dentate gyrus consists of spiny somatostatinergic interneurons. We examined the axon projections and synaptic connections made by spiny hilar interneurons labeled with biocytin in gerbils in vivo. Axon length was 152–497 mm/neuron. Sixty to 85% of the axon concentrated in the outer two thirds of the molecular layer of the dentate gyrus. The septotemporal span of the axon arbor extended over 48–82% of the total hippocampal length, which far exceeds the septotemporal span of axons of granule cells whose complete axon arbors extended over 15–29%. A three‐dimensionally reconstructed 216‐μm‐long spiny hilar interneuron axon segment in the outer third of the molecular layer formed an average of 1 synapse every 5.1 μm. Of the 42 symmetric (inhibitory) synapses formed by the reconstructed segment, 88% were with spiny dendrites of presumed granule cells, and 67% were with dendritic spines that also receive an asymmetric (excitatory) contact from an unlabeled axon terminal. Postembedding GABA‐immunocytochemistry revealed that 55% of the GABAergic synapses in the outer third of the molecular layer were with spines. Therefore, in the outer molecular layer, spiny hilar interneurons form synaptic contacts that appear to be positioned to exert inhibitory control near sites of excitatory synaptic input from the entorhinal cortex to granule cell dendritic spines. These findings demonstrate far‐reaching, yet highly specific, connectivity of individual interneurons and suggest that the loss of spiny hilar interneurons, as occurs in temporal lobe epilepsy, may contribute to hyperexcitability in the hippocampus. J. Comp. Neurol. 445:360–373, 2002. © 2002 Wiley‐Liss, Inc.
Brainstem projections to midline and intralaminar thalamic nuclei of the rat
Authors: Krout Karl E. , Belzer Rebecca E. , Loewy Arthur D.
Published: August 2002

The projections from the brainstem to the midline and intralaminar thalamic nuclei were examined in the rat. Stereotaxic injections of the retrograde tracer cholera toxin β ‐subunit (CTb) were made in each of the intralaminar nuclei of the dorsal thalamus: the lateral parafascicular, medial parafascicular, central lateral, paracentral, oval paracentral, and central medial nuclei; in the midline thalamic nuclei—the paraventricular, intermediodorsal, mediodorsal, paratenial, rhomboid, reuniens, and submedius nuclei; and, in the anteroventral, parvicellular part of the ventral posterior, and caudal ventral medial nuclei. The retrograde cell body labeling pattern within the brainstem nuclei was then analyzed. Nearly every thalamic site received a projection from the deep mesencephalic reticular, pedunculopontine tegmental, dorsal raphe, median raphe, laterodorsal tegmental, and locus coeruleus nuclei. Most intralaminar thalamic sites were also innervated by unique combinations of medullary and pontine reticular formation nuclei such as the subnucleus reticularis dorsalis, gigantocellular, dorsal paragigantocellular, lateral, parvicellular, caudal pontine, ventral pontine, and oral pontine reticular nuclei; the dorsomedial tegmental, subpeduncular tegmental, and ventral tegmental areas; and, the central tegmental field. In addition, most intralaminar injections resulted in retrograde cell body labeling in the substantia nigra, nucleus Darkschewitsch, interstitial nucleus of Cajal, and cuneiform nucleus. Details concerning the pathways from the spinal trigeminal, nucleus tractus solitarius, raphe magnus, raphe pallidus, and the rostral and caudal linear raphe nuclei to subsets of midline and intralaminar thalamic sites are discussed in the text. The discussion focuses on brainstem‐thalamic pathways that are likely involved in arousal, somatosensory, and visceral functions. J. Comp. Neurol. 448:53–101, 2002. © 2002 Wiley‐Liss, Inc.
Combination of gonadal steroid treatment and peripheral nerve grafting results in a peripheral motoneuron‐like pattern of BII‐tubulin mRNA expression in axotomized hamster rubrospinal motoneurons
Authors: Storer Paul D. , Houle John D. , Oblinger Monica , Jones Kathryn J.
Published: August 2002

Rubrospinal motoneurons (RSMN) represent a population of androgen receptor‐containing central motoneurons in rodents. In this study, the ability of testosterone propionate (TP), alone or in conjunction with a peripheral nerve graft (PNG), to alter the molecular program of injured RSMN was accomplished using βII‐tubulin cDNA probes and quantitative in situ hybridization (ISH). Initial fluoro‐gold labeling experiments following a T1 hemisection established that, as in the rat, the hamster rubrospinal system is essentially crossed and that injured RSMN concentrate in the ventrolateral region of the red nucleus. In the second experimental series, adult gonadectomized male hamsters were subjected to a right T1 hemisection, with half of the operated animals immediately subcutaneously implanted with 1 10 mm TP Silastic capsule and the other half sham implanted. In a third experimental series, animals were subjected to T1 hemisection, followed by transplantation of a predegenerated autologous segment of peripheral nerve. Half of the animals in each group received TP implants at the time of spinal cord injury and PNG. Postoperative times were 2, 7, and 14 days (dpo). Quantitative ISH was performed using a βII‐tubulin‐specific 33P‐labeled cDNA probe, emulsion autoradiography, and computerized image analysis for grain counting. Injury alone resulted in a short‐lived increase in βII‐tubulin mRNA expression in the RSMN at 2 dpo, with a significant decline to well below control values at 7 and 14 dpo. TP treatment or PNG alone attenuated, but did not prevent, the down‐regulation of βII‐tubulin mRNA. In contrast, the combination of TP with a PNG sustained the injury‐induced increase in βII‐tubulin mRNA levels throughout the postoperative period of 2, 7, and 14 dpo. The synergistic effects of the two treatment strategies confirm the importance of targeting multiple aspects of the injury response for therapeutic intervention. J. Comp. Neurol. 449:364–373, 2002. © 2002 Wiley‐Liss, Inc.
Evidence for regional heterogeneity in corticotropin‐releasing factor interactions in the dorsal raphe nucleus
Authors: Valentino Rita J. , Liouterman Larisa , Van Bockstaele Elisabeth J.
Published: August 2002

The dorsal raphe nucleus (DR) is innervated by fibers containing the stress‐related neurohormone corticotropin‐releasing factor (CRF), which alters DR neuronal activity and serotonin release in rats. This study examined the relative distribution of CRF‐immunoreactive fibers in the rat DR by using light level densitometry. Additionally, CRF‐immunoreactive processes within specific subregions of the DR were examined at the ultrastructural level by using electron microscopy. CRF‐immunoreactive fibers were organized within the DR along a caudal‐rostral gradient, such that proceeding rostrally, innervation shifted from dorsolateral to ventromedial. Numerous CRF‐immunoreactive axon terminals containing dense‐core vesicles were found in both the caudal dorsolateral region and the rostral ventromedial/interfascicular region. These formed synaptic specializations with unlabeled dendrites and frequently contacted nonlabeled axon terminals. Semiquantitative analysis revealed certain differences between the two regions with respect to the types of associations made by CRF‐immunoreactive terminals. Associations with dendrites were more frequent in the dorsolateral vs. ventromedial region (65% of 171 terminals vs. 39% of 233 terminals, respectively), whereas associations with axon terminals were more frequent in the ventromedial/interfascicular vs. the dorsolateral region (72% of 233 terminals vs. 57% of 171 terminals, respectively). Additionally, synaptic specializations between CRF‐immunoreactive terminals and dendrites were more frequently asymmetric in the dorsolateral region (60%) and symmetric (49%) in the ventromedial/interfascicular region. Regional differences in CRF terminal interactions in the DR could account for the reported heterogeneous effects of CRF on DR neuronal activity and forebrain serotonin release. Importantly, the present results provide anatomical substrates for regulation of the DR by endogenous CRF. J. Comp. Neurol. 435:450–463, 2001. © 2001 Wiley‐Liss, Inc.
μ‐opioid receptors are present in functionally identified sympathoexcitatory neurons in the rat rostral ventrolateral medulla
Authors: Aicher Sue A. , Schreihofer Ann M. , Kraus James A. , Sharma Sarita , Milner Teresa A. , Guyenet Patrice G.
Published: August 2002

Agonists of the μ‐opioid receptor (MOR) produce profound hypotension and sympathoinhibition when microinjected into the rostral ventrolateral medulla (RVL). These effects are likely to be mediated by the inhibition of adrenergic and other presympathetic vasomotor neurons located in the RVL. The present ultrastructural studies were designed to determine whether these vasomotor neurons, or their afferents, contain MORs. RVL bulbospinal barosensitive neurons were recorded in anesthetized rats and filled individually with biotinamide by using a juxtacellular labeling method. Biotinamide was visualized by using a peroxidase method and MOR was identified by using immunogold localization of an antipeptide antibody that recognizes the cloned MOR, MOR1. The subcellular relationship of MOR1 to RVL neurons with fast‐ or slow‐conducting spinal axons was examined by electron microscopy. Fast‐ and slow‐conducting cells were not morphologically distinguishable. Immunogold‐labeling for MOR1 was found in all RVL bulbospinal barosensitive neurons examined (9 of 9). MOR1 was present in 52% of the dendrites from both types of cells and in approximately half of these dendrites the MOR1 was at nonsynaptic plasmalemmal sites. A smaller portion of biotinamide‐labeled dendrites (16%) from both types of cells were contacted by MOR1‐containing axons or axon terminals. Together, these results suggest that MOR agonists can directly influence the activity of all types of RVL sympathoexcitatory neurons and that MOR agonists may also influence the activity of afferent inputs to these cells. The heterogenous distribution of MORs within individual RVL neurons indicates that the receptor is selectively targeted to specific pre‐ and postsynaptic sites. J. Comp. Neurol. 433:34–47, 2001. © 2001 Wiley‐Liss, Inc.
Regenerating descending axons preferentially reroute to the gray matter in the presence of a general macrophage/microglial reaction caudal to a spinal transection in adult zebrafish
Authors: Becker Thomas , Becker Catherina G.
Published: August 2002

We analyzed pathway choices of regenerating, mostly supraspinal, descending axons in the spinal cord of adult zebrafish and the cellular changes in the spinal cord caudal to a lesion site after complete spinal transection. Anterograde tracing (by application of the tracer rostral to the spinal lesion site) showed that significantly more descending axons (74%) regenerated in the spinal gray matter of the caudal spinal cord than would be expected from random growth. Retrograde tracing (by application of the tracer caudal to the spinal lesion site) showed that, rostral to the lesion, most of these axons (80%) extended into the major white matter tracts. Thus, ventral descending tracts often were devoid of labeled axons caudal to a spinal lesion but contained many axons rostral to the lesion in the same animals, indicating a pathway switch of descending axons from the white matter to the gray matter. Ascending axons of spinal neurons were not observed regrowing to the rostral tracer application site; therefore, they most likely did not contribute to the axonal populations analyzed. A macrophage/microglia response within 2 days of spinal cord transection, along with phagocytosis of myelin, was observed caudal to the transection by immunohistochemistry and electron microscopy. Nevertheless, caudal to the lesion, descending tracts in the white matter were filled with myelin debris during the time of axonal regrowth, at least up to 6 weeks postlesion. We suggest that the spontaneous regeneration of axons of supraspinal origin after spinal cord transection in adult zebrafish may be due in part to the axons' ability to negotiate novel pathways in the spinal cord gray matter. J. Comp. Neurol. 433:131–147, 2001. © 2001 Wiley‐Liss, Inc.
Subcellular localization of α‐2A‐adrenergic receptors in the rat medial nucleus tractus solitarius: Regional targeting and relationship with catecholamine neurons
Authors: Glass Michael J. , Huang Jie , Aicher Sue A. , Milner Teresa A. , Pickel Virginia M.
Published: August 2002

α‐2A‐adrenergic receptor (α2A‐AR) agonists modulate diverse autonomic functions. These actions are believed to involve functionally specialized, second‐order neurons in catecholamine‐containing portions of the medial nucleus tractus solitarius (mNTS) at both intermediate (NTSi) and caudal (NTSc) levels. However, the cellular mechanisms subserving α2A‐AR‐mediated actions within the mNTS have yet to be established. Immunocytochemistry was employed to examine the subcellular distribution of α2A‐AR in both the intermediate and caudal mNTS and its association with cells containing the catecholamine‐synthesizing enzyme tyrosine hydroxylase (TH). Quantitative regional comparison using immunogold showed that this receptor was distributed differentially to dendrites (NTSi, 46%; NTSc, 31%) and glia (NTSi, 29%; NTSc, 48%) at different levels of the NTS. Somata, axons, and terminals less frequently contained α2A‐AR. The subcellular distribution of α2A‐AR relative to catecholaminergic neurons also was similar within both subregions. Approximately 50% of α2A‐AR‐labeled somata also contained TH. In somatic profiles, α2A‐AR labeling was often found in the cytosol and in association with endoplasmic reticulum and Golgi complexes, sites of receptor synthesis and trafficking. Approximately 20% of α2A‐AR‐immunoreactive dendrites also contained TH, where the receptor was often found on extrasynaptic portions of the plasma membrane near unlabeled terminals, some of which made symmetric contacts. However, TH‐labeled terminals and dendrites usually were detected in the neuropil at a short distance (<10 μm) from α2A‐AR‐labeled neurons. α2A‐AR‐labeled glia frequently apposed unlabeled dendrites and terminals and were often located near TH‐immunoreactive dendrites. These results indicate that, within the mNTS, α2A‐AR is involved in a variety of autonomic processes, including postsynaptic modulation of mostly noncatecholaminergic dendrites, as well as influencing glia functions. J. Comp. Neurol. 433:193–207, 2001. © 2001 Wiley‐Liss, Inc.
Expression of the melanin‐concentrating hormone (MCH) receptor mRNA in the rat brain
Authors: Saito Yumiko , Cheng Michelle , Leslie Frances M. , Civelli Olivier
Published: August 2002

The melanin‐concentrating hormone (MCH) system is thought to be an important regulator of food intake. Recently the orphan G protein‐coupled receptor SLC‐1 was identified as the MCH receptor (MCHR). Preliminary analyses of MCHR mRNA distribution have supported a role for the MCH system in nutritional homeostasis. We report here a complete anatomical distribution of the MCHR mRNA. We have found high levels of expression of MCHR mRNA in most anatomical areas implicated in control of olfaction, with the exception of the main olfactory bulb. Dense labeling was also detected in the hippocampal formation, subiculum, and basolateral amygdala, all of which are important in learning and memory, and in the shell of the nucleus accumbens, a substrate for motivated behavior and feeding. Within the hypothalamus, MCHR mRNA was moderately expressed in the ventromedial nucleus, arcuate nucleus, and zona incerta, all of which serve key roles in the neuronal circuitry of feeding. In the brainstem, strong expression was observed in the locus coeruleus, which is implicated in arousal, as well as in nuclei that contribute to orofacial function and mastication, including the facial, hypoglossal, motor trigeminal, and dorsal motor vagus nuclei. In most regions there was a good correspondence between MCHR mRNA distribution and that of MCH‐immunoreactive fibers. Taken together, these data suggest that MCH may act at various levels of the brain to integrate various aspects of feeding behavior. However, the extensive MCHR distribution throughout the brain suggests that this receptor may play a role in other functions, most notably reinforcement, arousal, sensorimotor integration, and autonomic control. J. Comp. Neurol. 435:26–40, 2001. © 2001 Wiley‐Liss, Inc.
Borders and cytoarchitecture of the perirhinal and postrhinal cortices in the rat
Authors: Burwell Rebecca D.
Published: August 2002

Cytoarchitectonic and histochemical analyses were carried out for perirhinal areas 35 and 36 and the postrhinal cortex, providing the first detailed cytoarchitectonic study of these regions in the rat brain. The rostral perirhinal border with insular cortex is at the extreme caudal limit of the claustrum, consistent with classical definitions of insular cortex dating back to Rose ([1928] J. Psychol. Neurol. 37:467–624). The border between the perirhinal and postrhinal cortices is at the caudal limit of the angular bundle, as previously proposed by Burwell et al. ([1995] Hippocampus 5:390–408). The ventral borders with entorhinal cortex are consistent with the Insausti et al. ([1997] Hippocampus 7:146–183) description of that region and the Dolorfo and Amaral ([1998] J. Comp. Neurol. 398:25–48) connectional findings. Regarding the remaining borders, both the perirhinal and postrhinal cortices encroach upon temporal cortical regions as defined by others (e.g., Zilles [1990] The cerebral cortex of the rat, p 77–112; Paxinos and Watson [1998] The rat brain in stereotaxic coordinates). Based on cytoarchitectonic and histochemical criteria, perirhinal areas 35 and 36 and the postrhinal cortex were further subdivided. Area 36 was parceled into three subregions, areas 36d, 36v, and 36p. Area 35 was parceled into two cytoarchitectonically distinctive subregions, areas 35d and 35v. The postrhinal cortex was divided into two subregions, areas PORd and PORv. These regional definitions of perirhinal areas 35 and 36 and the postrhinal cortex were confirmed by new empirical analyses of previously reported quantitative connectional data (Burwell and Amaral [1998a] J. Comp. Neurol. 398:179–205). J. Comp. Neurol. 437:17–41, 2001. © 2001 Wiley‐Liss, Inc.
Localization of two high‐threshold potassium channel subunits in the rat central auditory system
Authors: Li Wenge , Kaczmarek Leonard K. , Perney Teresa M.
Published: August 2002

The firing pattern of auditory neurons is determined in part by the type of voltage‐sensitive potassium channels expressed. The expression patterns for two high‐threshold potassium channels, Kv3.1 and Kv3.3, that differ in inactivation properties were examined in the rat auditory system. The positive activation voltage and rapid deactivation kinetics of these channels provide rapid repolarization of action potentials with little effect on action potential threshold. In situ hybridization experiments showed that Kv3.3 mRNA was highly expressed in most auditory neurons in the rat brainstem, whereas Kv3.1 was expressed in a more limited population of auditory neurons. Notably, Kv3.1 mRNA was not expressed in neurons of the medial and lateral superior olive and a subpopulation of neurons in the ventral nucleus of the lateral lemniscus. These results suggest that Kv3.3 channels may be the dominant Kv3 subfamily member expressed in brainstem auditory neurons and that, in some auditory neurons, Kv3.1 and Kv3.3 may coassemble to form functional channels. The localization of Kv3.1 protein was examined immunohistochemically. The distribution of stained somata and neuropil varied across auditory nuclei and correlated with the distribution of Kv3.1 mRNA‐expressing neurons and their terminal arborizations, respectively. The intensity of Kv3.1 immunoreactivity varied across the tonotopic map in the medial nucleus of the trapezoid body with neurons responding best to high‐frequency tones most intensely labeled. Thus, auditory neurons may vary the types and amount of K+ channel expression in response to synaptic input to subtly tune their firing properties. J. Comp. Neurol. 437:196–218, 2001. © 2001 Wiley‐Liss, Inc.
GABA‐immunoreactive neurons in the mushroom bodies of the honeybee: An electron microscopic study
Authors: Ganeshina Olga , Menzel Randolf
Published: August 2002

Synaptic contacts of γ‐aminobutyric acid (GABA) ‐immunoreactive neurons in honeybee mushroom bodies were studied by using electron microscopic immunocytochemistry. In the lip region of the calyx neuropil, GABA‐immunoreactive profiles formed synapses onto both small postsynaptic profiles (76%) and large immunonegative boutons (4%), which were likely to belong to the intrinsic and extrinsic mushroom body neurons, respectively. Three morphologic types of the large immunonegative boutons were distinguished: “light,” “dark,” and “dense core”; all of them received synaptic inputs from the GABA‐immunoreactive profiles. A significant proportion of the synapses formed by the GABA‐immunoreactive neurons in the lip region (20%) were input synapses from immunonegative neurons. Analysis of thin serial sections showed that the output and input synapses formed microcircuits in which both large immunonegative boutons and small postsynaptic profiles were involved. We interpret these findings to show that negative feedforward and feedback loops exist within the microcircuits of the lip region. J. Comp. Neurol. 437:335–349, 2001. © 2001 Wiley‐Liss, Inc.
Motoneurons of twitch and nontwitch extraocular muscle fibers in the abducens, trochlear, and oculomotor nuclei of monkeys
Authors: Büttner‐Ennever Jean A. , Horn Anja K.E. , Scherberger Hansjoerg , D'ascanio Paola
Published: August 2002

Eye muscle fibers can be divided into two categories: nontwitch, multiply innervated muscle fibers (MIFs), and twitch, singly innervated muscle fibers (SIFs). We investigated the location of motoneurons supplying SIFs and MIFs in the six extraocular muscles of monkeys. Injections of retrograde tracers into eye muscles were placed either centrally, within the central SIF endplate zone; in an intermediate zone, outside the SIF endplate zone, targeting MIF endplates along the length of muscle fiber; or distally, into the myotendinous junction containing palisade endings. Central injections labeled large motoneurons within the abducens, trochlear or oculomotor nucleus, and smaller motoneurons lying mainly around the periphery of the motor nuclei. Intermediate injections labeled some large motoneurons within the motor nuclei but also labeled many peripheral motoneurons. Distal injections labeled small and medium‐large peripheral neurons strongly and almost exclusively. The peripheral neurons labeled from the lateral rectus muscle surround the medial half of the abducens nucleus: from superior oblique, they form a cap over the dorsal trochlear nucleus; from inferior oblique and superior rectus, they are scattered bilaterally around the midline, between the oculomotor nucleus; from both medial and inferior rectus, they lie mainly in the C‐group, on the dorsomedial border of oculomotor nucleus. In the medial rectus distal injections, a “C‐group extension” extended up to the Edinger‐Westphal nucleus and labeled dendrites within the supraoculomotor area. We conclude that large motoneurons within the motor nuclei innervate twitch fibers, whereas smaller motoneurons around the periphery innervate nontwitch, MIF fibers. The peripheral subgroups also contain medium‐large neurons which may be associated with the palisade endings of global MIFs. The role of MIFs in eye movements is unclear, but the concept of a final common pathway must now be reconsidered. J. Comp. Neurol. 438:318–335, 2001. © 2001 Wiley‐Liss, Inc.
Anatomy and physiology of neurons with processes in the accessory medulla of the cockroach Leucophaea maderae
Authors: Loesel Rudi , Homberg Uwe
Published: August 2002

The accessory medulla (AMe), a small neuropil in the insect optic lobe, has been proposed to serve a circadian pacemaker function analogous to the role of the suprachiasmatic nucleus in mammals. Building upon considerable knowledge of the circadian system of the cockroach Leucophaea maderae, we investigated the properties of AMe neurons in this insect with intracellular recordings combined with dye injections. Responses of neurons with processes in the AMe to visual stimuli, including stationary white light, moving objects, and polarized light were compared with the responses of adjacent medulla tangential neurons. Neurons with processes in the AMe and additional ramifications in the medulla strongly responded to stationary light stimuli and might, therefore, be part of photic entrainment pathways to the clock. Accessory medulla neurons lacking significant processes in the medulla but with projections to the midbrain or to the contralateral optic lobe, in contrast, responded weakly or not at all to light and, thus, seem to be part of the clock's output pathway. Two types of commissural neurons with tangential arborizations in both medullae were sensitive to polarized light, suggesting a role of these neurons in celestial navigation. Sidebranches in the AMae of one of the two cell types are discussed with respect to a possible involvement of the AMe in polarization vision. Finally, neurons responding to movement stimuli did not arborize in the AMe. The results show that the AMe receives photic input and support a role of this neuropil in circadian timekeeping functions. J. Comp. Neurol. 439:193–207, 2001. © 2001 Wiley‐Liss, Inc.
Crack edge element of three‐dimensional displacement discontinuity method with boundary division into triangular leaf elements
Authors: Li H. , Liu C. L. , Mizuta Y. , Kayupov M. A.
Published: August 2002

In this paper, the existing Displacement Discontinuity Method (DDM) for three‐dimensional elastic analysis with boundary discretized into triangular elements, which is purely based on analytical integrals, is extended from the constant element to the square‐root crack edge element. In order to evaluate the singular integral when the receiver point falls into the remitter element, i.e., the observed point (x,y) ∈Δ, a part analytical and part numerical integration procedure is adopted effectively. The newly developed codes prove valid in estimating the Stress Intensity Factor (SIF) KI. Furthermore, for the sake of keeping the advantages of high‐speed and high‐accuracy in developing the numerical system, a novel method to realize pure analytical integration of influence function is found by the aid of symbolic computation technology of Mathematica. Copyright © 2001 John Wiley & Sons, Ltd.
On Hilbert, Fourier, and wavelet transforms
Authors: Penner R. C.
Published: August 2002

Several new families of wavelets, which are derived from earlier work by the author on Teichmüller theory, are introduced and studied. These wavelets are associated with the modular group rather than the affine group of the real line as for classical wavelets. In further contrast to the usual setting, there are explicit and essentially algebraic formulas relating wavelet and Fourier expansions. Furthermore, rather than relying on equally spaced multiscale sampling methods, the wavelet expansions introduced here rely instead on an explicit, nonuniformly spaced, multiscale sampling method that depends upon the Farey sequence of classical number theory. These ingredients combine to give novel methods for calculating wavelet, Fourier, and Hilbert transforms with potential applications to myriad problems in electrical engineering. By employing a new characteristic length associated to 2 × 2 matrices, finiteness and convergence properties of the wavelet expansions are derived. For functions with more than 5/2 derivatives inL2, one of our wavelet families forms a frame and the Hilbert transform is calculable in hyperbolic coordinates. © 2002 Wiley Periodicals, Inc.
Current differential amplifiers: new circuits and applications
Authors: Souliotis George , Chrisanthopoulos Angelos , Haritantis Ioannis
Published: August 2002

New CMOS current differential amplifiers are proposed suitable for analogue signal processing at high frequencies. They consist of simple current mirrors, which are easy to design and to implement in IC form. Low‐voltage low‐power design is feasible. Relying on these devices a number of applications are obtained, including lossy and lossless integrators, simulated inductors, active filters, and harmonic oscillators. Theoretical expressions are given for all of the proposed new circuits. The verification of the circuits is also achieved by simulation. Copyright 2001 © John Wiley & Sons, Ltd.
Cellular neural networks based on resonant tunnelling diodes
Authors: Hänggi Martin , Chua Leon O.
Published: August 2002

Resonant tunnelling diodes (RTDs) have intriguing properties which make them a primary nanoelectronic device for both analogue and digital applications. We propose two different types of RTD‐based cells for the cellular neural network (CNN) which exhibit superior performance in terms of complexity, functionality, or processing speed compared to standard cells. In the first cell model, the resistor of the standard cell is replaced by an RTD, which results in a more compact and versatile cell which requires neither self‐feedback nor a non‐linear output function, and allows three stable equilibrium points. If a resonant tunnelling transistor (RTT) is used instead of the RTD, the dynamics can be controlled through its gate voltage as an additional network parameter. In a majority of CNN applications, bistable cells are sufficient. Utilizing RTD‐based bistable logic elements to store the state of the cell, switching occurs almost instantaneously as virtually no charge transfer is necessary, and it is possible to implement non‐linear connections in a straightforward manner. Hence, it turns out that RTD‐based CNNs are tailor‐made for the implementation of extremely fast bipolar operations and non‐linear templates. The ideas presented in this paper may also be beneficially applied to other types of circuits and systems such as A/D converters or sigma‐delta modulators. Copyright © 2001 John Wiley & Sons, Ltd.
Flow cytometry measurement of the DNA contents of G0/G1 diploid cells from three different teleost fish species
Authors: Ciudad Juana , Cid Elena , Velasco Almudena , Lara Juan M. , Aijón José , Orfao Alberto
Published: August 2002

Background

Although there is a lot information in the literature about genome size in fish, a high variability among data for the same species is reported, being mainly related to methodological aspects. Flow cytometry‐based fluorescence measurements of intercalating dyes is the most attractive approach due to its precision, objectivity, high speed, and relative simplicity.

Methods

We analyze the DNA content of G0/G1 diploid nuclei of three teleost species (Carassius auratus, Tinca tinca, and Danio rerio) using flow cytometry. Forty‐three animals were used and up to 50,000 retinal cells were analyzed per sample. Propidium iodide‐associated fluorescence was assessed using a FACSCalibur flow cytometer. Standard human leukocytes were used as a reference.

Results

Our results show that C. auratus (3.584 ± 0.058 pg per nucleus) and D. rerio (3.357 ± 0.074 pg per nucleus) showed similar DNA contents per cell, whereas it was significantly lower (2.398 ± 0.038 pg per nucleus) in T. tinca. Interestingly, a low intraspecies variability was observed, the coefficient of variation being 1.608%, 2.198%, and 1.573% for C. auratus, D. rerio, and T. tinca, respectively.

Conclusions

The methodology used in this study provides an accurate and easy measurement of the genome size of a species. Cytometry 48:20–25, 2002. © 2002 Wiley‐Liss, Inc.
DNA copy number amplifications in sarcomas with homogeneously staining regions and double minutes
Authors: Menghi‐Sartorio Samantha , Mandahl Nils , Mertens Fredrick , Picci Piero , Knuutila Sakari
Published: August 2002

To identify DNA amplifications in sarcomas, comparative genomic hybridization was performed on 27 cases that were likely to display high‐level DNA copy number gains. In all cases, chromosome banding analysis had revealed homogeneously staining regions or double minutes, i.e., cytogenetic signs of gene amplification. In most cases, gains predominated over losses. Low‐level amplifications (ratio 1.3:1.5) were seen in 20 cases. High‐level amplifications (ratio >1.5) exceeded the frequencies seen in published, unselected sarcomas of similar histotypes and were detected in 16 tumors: 4/4 osteosarcomas, 5/8 malignant fibrous histiocytomas, 3/7 leiomyosarcomas, 1/2 myosarcomas, 0/1 liposarcoma, 0/1 rhabdomyosarcoma, 1/1 pleomorphic sarcoma, 0/1 myxofibrosarcoma, 1/1 malignant mesenchymona, and 1/1 malignant schwannoma, with two to four chromosomal regions involved in nine tumors. Recurrent amplifications involved 1p33‐p32, 5p15‐p14, 7pter‐p12, 7q21‐qter, 8q21.3‐qter, 11q22‐q23, 16p13.2‐p12, 19q12‐q13.1, 20q11.2‐qter, and 22q12‐q13. Most of the recurrent gains/amplifications we detected have been reported in sarcomas previously. A novel gain/amplification was seen at 2q14.3‐q21 in five cases of four sarcoma types. The disparate pattern of amplified sequences, the poor correspondence between the localization of low‐ and high‐level amplifications, and the chromosomal position of homogeneously staining regions suggest the involvement of many genes in the amplifications and that the genes rarely maintain their native position in these tumors. Cytometry (Comm. Clin. Cytometry) 46:79–84, 2001. © 2001 Wiley‐Liss, Inc.
Evaluation of an antibody‐based genotype classification of the platelet fibrinogen receptor (GPIIb/IIIa)
Authors: Schwippert‐Houtermans B. , Strapatsakis S. , Roesen P. , Tschoepe D.
Published: August 2002

Platelet membrane glycoprotein (GP) IIb/IIIa is the central molecule in platelet adhesion and aggregation by high‐affinity binding of fibrinogen. Polymorphism of the beta chain of the receptor, especially the GPIIIa‐proline33 allele [HPA‐1b, Zwb, PI(A2)], has been suggested to be associated with a variety of vascular diseases, such as coronary stenosis, myocardial infarction, cerebral ischemia, or venous thrombosis. Using clinical chemistry standards, we evaluate a flow cytometric whole‐blood, antibody‐based method to determine the genotype [PI(A1A1), PI(A1A2), PI(A2A)] versus polymerase chain reaction (PCR)‐based DNA restriction fragment length analysis in 220 individuals. Both homozygous and heterozygous genotypes differ in the expression of binding sites for the monoclonal antibody, SZ21. Agreement between the two methods was achieved in 187 cases, which reflects a test validity of 85%, a sensitivity of 83.6%, and a specificity of 85.4%. We conclude that flow cytometry is reliable for classifying the PI(AX) genotype. The performance characteristics are easy, fast, and cheap (genomics by proteomics). These features make it suitable for screening patients and broad populations for the future risk of cardiovascular ischemic events. Cytometry (Comm. Clin. Cytometry) 46:238–242, 2001. © 2001 Wiley‐Liss, Inc.
An efficient location cache scheme for three‐level database architecture in PCS networks
Authors: Han Youn‐Hee , Han Sang‐Cheol , Yang KwonWoo , Hwang Chong‐Sun , Jeong Young‐Sik
Published: August 2002

Recently, hierarchical architecture for location databases has been proposed in order to accommodate the growing number of personal communication systems users. With the three‐level hierarchical database architecture, which is compatible with the current cellular mobile systems, newly developed additional databases, including the regional location database (RLR), are positioned between the HLR and the VLRs. We propose an efficient cache scheme,the double T‐thresholds location cache scheme, which could reduce the network and database costs to lookup a portable using the three‐level architecture. This scheme extends the existing T‐threshold location cache scheme, which is effective only under the two‐level architecture of location databases currently adopted by IS‐41 and GSM. The idea behind our proposed scheme is to use two pieces of cache information, VLR and RLR, which serve the called portables. These two pieces are required in order to exploit not only the locality of a registration area (RA), but also the locality of a regional registration area (RRA), a wide area covered by the RLR. We also use two threshold values in order to determine whether the two pieces are obsolete. In order to model the RRA residence time,the branching Erlang‐∞ distributionis introduced. The cost analysis presented in this paper shows that the doubleT‐thresholds location cache scheme significantly reduces the network and database costs for most patterns of portables. Copyright © 2001 John Wiley & Sons, Ltd.
Blocking performance of fixed‐paths least‐congestion routing in multifibre WDM networks
Authors: Li Ling , Somani Arun K.
Published: August 2002

Wavelength‐routed all‐optical networks have been receiving significant attention for high‐capacity transport applications. Good routing and wavelength assignment (RWA) algorithms are critically important in order to improve the performance of wavelength‐routed WDM networks. Multifibre WDM networks, in which each link consists of multiple fibres and each fibre carries information on multiple wavelengths, offer the advantage of reducing the effect of the wavelength continuity constraint without using wavelength converters. A wavelength that cannot continue on the next hop on the same fibre can be switched to another fibre using an optical cross‐connect (OXC) if the same wavelength is free on one of the other fibres. However, the cost of a multifibre network is likely to be higher than a single‐fibre network with the same capacity, because more amplifiers and multiplexers/demultiplexers may be required. The design goal of a multifibre network is to achieve a high network performance with the minimum number of fibres.

In this paper, we study the blocking performance of fixed‐paths least‐congestion (FPLC) routing in multifibre WDM networks. A new analytical model with the consideration of link‐load correlation is developed to evaluate the blocking performance of the FPLC routing. The analytical model is a generalized model that can be used in both regular (e.g. mesh‐torus) and irregular (e.g. NSFnet) networks. It is shown that the analytical results closely match the simulation results, which indicate that the model is adequate in analytically predicting the performance of the FPLC routing in different networks.

Two FPLC routing algorithms, wavelength trunk (WT)‐based FPLC and lightpath (LP)‐based FPLC, are developed and studied. Our analytical and simulation results show that the LP‐based FPLC routing algorithm can use multiple fibres more efficiently than the WT‐based FPLC and the alternate path routing. In both the mesh‐torus and NSFnet networks, limited number of fibres is sufficient to guarantee high network performance. Copyright © 2002 John Wiley & Sons, Ltd.