bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuronal organization of the melanin‐concentrating hormone system in primitive actinopterygians: Evolutionary changes leading to teleosts
Authors: Baker Bridget I. , Bird David J.
Published: August 2002

Hypothalamic melanin‐concentrating hormone (MCH) neurones occur in all vertebrates and have an apparent neuromodulatory role. In teleost fish, however, MCH is used also as a neurohypophysial hormone, controlling skin color, and as a hypophysiotrophic peptide. This work describes the central location of immunoreactive MCH perikarya and their projections to the pituitary in a range of ancestral fish to determine the phylogenetic stage when the peptide adopted these roles. In all actinopterygians examined, including polypteriformes, chondrosteans, holosteans, and teleosts, immunoreactive fibers were abundant in the median eminence or, in the case of teleosts, within the pars distalis itself, suggesting MCH acquired a hypophysial regulatory role early in vertebrate evolution. MCH fibers appeared to be absent from the posterior neurohypophysis of the polypteriform Calamoichthys but were evident in this region in the chondrostean Acipensor, the holosteans Lepisosteus and Amia, and all teleosts, suggesting its use as a neurohypophysial hormone. The ability of MCH to induce skin pallor seems to have arisen at a later stage, probably in the preholosteans. This hormonal role coincides with the migration of MCH perikarya away from the ventricular surface and their enlargement into magnocellular neurones. In the higher teleosts, magnocellular hypothalamo‐neurohypophysial neurones predominate in size and number, whereas smaller periventricular MCH neurones associated with the paraventricular organ, that are prominent in lampreys, early actinopterygians and tetrapods, are reduced in teleosts. The data suggest that, in teleost fish, earlier functions of the peptide may have become subordinate to its novel pigmentary role. J. Comp. Neurol. 442:99–114, 2002. © 2002 Wiley‐Liss, Inc.
Morphology and projection pattern of medial and dorsal pallial neurons in the frog Discoglossus pictus and the salamander Plethodon jordani
Authors: Westhoff Guido , Roth Gerhard
Published: August 2002

In the frog Discoglossus pictus and the salamander Plethodon jordani, the morphology and axonal projection pattern of neurons in the medial and dorsal pallium were determined by intracellular biocytin labeling. A total of 77 pallial neurons were labeled in the frog and 58 pallial neurons in the salamander. Within the medial pallium (MP) of the frog, four types of neurons were identified on the basis of differences in their axonal projection pattern. Type I neurons have bilateral projections into telencephalic and diencephalic areas; type II neurons have bilateral projections to telencephalic areas and ipsilaterally descending projections to diencephalic regions; type III neurons have only intratelencephalic connections, and a single type IV neuron has ipsilaterally descending projections. The somata of the four types occupy four nonoverlapping zones. Neurons of the dorsal pallium (DP) project exclusively to the ipsilateral MP and to the dorsal edge of the lateral pallium. In the ventral MP of the salamander, neurons have mostly intratelencephalic projections. Neurons in the dorsal MP project bilaterally to diencephalic and telencephalic regions. Neurons in the medial DP project ipsilaterally to the MP, lateral septum, nucleus accumbens, medial amygdala, and the internal granule layer of the olfactory bulb. In five cases, fibers were found in the commissura hippocampi, but in only two cases could these fibers be followed toward the contralateral MP and septum. Neurons in the lateral DP had no contralateral projections; they projected to the ipsilateral MP and in eight cases to the ipsilateral septum as well. Based on similarities of cytoarchitecture and projection pattern in neurons of the MP and DP, it is proposed that both frogs and salamanders have an MP subdivided into a ventral and dorsal portion, and a DP subdivided into a medial and a lateral portion. J. Comp. Neurol. 445:97–121, 2002. © 2002 Wiley‐Liss, Inc.
Sublaminar organization of the mouse olfactory bulb nerve layer
Authors: Au Winnie W. , Treloar Helen B. , Greer Charles A.
Published: August 2002

Olfactory sensory neuron (OSN) axons coalesce to form the olfactory nerve (ON) and then grow from the olfactory epithelium to the olfactory bulb (OB), enter the olfactory nerve layer (ONL), reorganize extensively, and innervate specific glomeruli. Within the ON and ONL a population of glial cells, the olfactory ensheathing cells (OECs), surround OSN axon fascicles. To better understand the relationship between OECs and axon fascicles in the ONL of the adult mouse, we used confocal microscopy and antibodies to the low affinity nerve growth factor receptor p75 (p75), glial fibrillary acidic protein (GFAP), neuropeptide Y (NPY), and S‐100 to identify glia. Antibodies to olfactory marker protein (OMP) and neuronal cell adhesion molecule (NCAM) were used to identify OSN axons. Electron microscopy characterized the ONL ultrastructure. We found that glial processes were not uniformly distributed in the ONL of the mouse. The p75+ OEC processes were restricted to the ON and the outer ONL sublamina, and oriented parallel to the plane of the OB layers. In the inner ONL NPY+ OEC‐like processes were seen. GFAP+ processes were restricted to the inner ONL sublamina, the ONL/GL boundary, and the GL, where they delineated loosely aggregated axon fascicles that entered the glomeruli obliquely. S‐100+ processes and somata were distributed throughout the ONL; the outer and inner ONL were equivalent in their S‐100 staining. Ultrastructural studies showed that, although OECs could be identified in both the outer and inner ONL, in the latter, their relationship to bundles of OEC axons appeared less orderly than seen in the outer ONL. Our data demonstrate a differential organization of the ONL that could subserve distinct functions; axon extension may occur predominately in the outermost ONL, whereas glomerular targeting occurs in the inner sublamina of the ONL. J. Comp. Neurol. 446:68–80, 2002. © 2002 Wiley‐Liss, Inc.
Postnatal development of nicotinamide adenine dinucleotide phosphate‐diaphorase‐positive neurons in the retina of the golden hamster
Authors: Tay David , Diao Yun‐Cheng , Xiao Yue‐Mei , So Kwok‐Fai
Published: August 2002

The histochemical method was used to investigate the postnatal development of nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d) ‐positive neurons in retinas of the golden hamster. NADPH‐d‐positive neurons were discernible in the retina at postnatal day (P)1. From P4 onward to adulthood, when the retina acquired its laminated characteristics, NADPH‐d‐ positive neurons were observed in the inner nuclear layer (INL) and the ganglion cell layer (GCL). Results showed that NADPH‐d‐positive neurons in INL and GCL followed different time courses and patterns in their development. NADPH‐d‐positive neurons in INL underwent a sharp increase from P4 to P8 (3.6‐fold), followed by a decrease to 46% of the maximum at P12. This value was maintained relatively constant to the adult level. The mean diameters of NADPH‐d‐positive neurons in INL, which were smaller than those in the GCL for all ages, increased from P8 to P12 and from P20 to adulthood. As for neurons in the GCL, the increase in cell number was not so apparent for the earlier postnatal days until P20; thereafter, an obvious increase to the adult level was observed. The mean diameters of the NADPH‐d‐positive cell bodies in the GCL increased with age, except for P16–P20, during which time there was a slight and insignificant decrease. The tendency of changes in cell density was basically similar to that of the total number for both the INL and the GCL. Between P12 and P20, the density distribution map of the NADPH‐d‐positive neurons underwent dramatic changes: The highest density shifted from the upper central retina at the earlier postnatal days to the lower central retina in the adult. The two waves of increase in NADPH‐d‐positive neurons coincide with the process of axonal elongation and synaptogenesis and the acquisition of visual function and experience. It is suggested that these NADPH‐d‐positive neurons are related to these two developmental events. J. Comp. Neurol. 446:342–348, 2002. © 2002 Wiley‐Liss, Inc.
Subcellular distribution of 5‐HT1b and 5‐HT7 receptors in the mouse suprachiasmatic nucleus
Authors: Belenky Michael A. , Pickard Gary E.
Published: August 2002

The suprachiasmatic nucleus (SCN), a circadian oscillator, receives glutamatergic afferents from the retina and serotonergic (5‐HT) afferents from the median raphe. 5‐HT1B and 5‐HT7 receptor agonists inhibit the effects of light on SCN circadian activity. Electron microscopic (EM) immunocytochemical procedures were used to determine the subcellular localization of 5‐HT1B and 5‐HT7 receptors in the SCN. 5‐HT1B receptor immunostaining was associated with the plasma membrane of thin unmyelinated axons, preterminal axons, and terminals of optic and nonoptic origin. 5‐HT1B receptor immunostaining in terminals was almost never observed at the synaptic active zone. To a much lesser extent, 5‐HT1B immunoreaction product was noted in dendrites and somata of SCN neurons. 5‐HT7 receptor immunoreactivity in γ‐aminobutyric acid (GABA), vasoactive intestinal polypeptide (VIP), and vasopressin (VP) neuronal elements in the SCN was examined by using double‐label procedures. 5‐HT7 receptor immunoreaction product was often observed in GABA‐, VIP‐, and VP‐immunoreactive dendrites as postsynaptic receptors and in axonal terminals as presynaptic receptors. 5‐HT7 receptor immunoreactivity in terminals and dendrites was often associated with the plasma membrane but very seldom at the active zone. In GABA‐, VIP‐, and VP‐immunoreactive perikarya, 5‐HT7 receptor immunoreaction product was distributed throughout the cytoplasm often in association with the endoplasmic reticulum and the Golgi complex. The distribution of 5‐HT1B receptors in presynaptic afferent terminals and postsynaptic SCN processes, as well as the distribution of 5‐HT7 receptors in both pre‐ and postsynaptic GABA, VIP, and VP SCN processes, suggests that serotonin plays a significant role in the regulation of circadian rhythms by modulating SCN synaptic activity. J. Comp. Neurol. 432:371–388, 2001. © 2001 Wiley‐Liss, Inc.
Functional and anatomical localization of mu opioid receptors in the striatum, amygdala, and extended amygdala of the nonhuman primate
Authors: Daunais James B. , Letchworth Sharon R. , Sim‐Selley Laura J. , Smith Hilary R. , Childers Steven R. , Porrino Linda J.
Published: August 2002

The subregional distribution of mu opioid receptors and corresponding G‐protein activation were examined in the striatum, amygdala, and extended amygdala of cynomolgus monkeys. The topography of mu binding sites was defined using autoradiography with [3H]DAMGO, a selective mu ligand. In adjacent sections, the distribution of receptor‐activated G proteins was identified with DAMGO‐stimulated guanylyl 5′(γ‐[35S]thio)triphosphate ([35S]GTPγS) binding. Within the striatum, the distribution of [3H]DAMGO binding sites was characterized by a distinct dorsal–ventral gradient with a higher concentration of binding sites at more rostral levels of the striatum. [3H]DAMGO binding was further distinguished by the presence of patch‐like aggregations within the caudate, as well as smaller areas of very dense receptor binding sites, previously identified in human striatum as neurochemically unique domains of the accumbens and putamen (NUDAPs). The amygdala contained the highest concentration of [3H]DAMGO binding sites measured in this study, with the densest levels of binding noted within the basal, accessory basal, paralaminar, and medial nuclei. In the striatum and amygdala, the distribution of DAMGO‐stimulated G‐protein activation largely corresponded with the distribution of mu binding sites. The central and medial nuclei of the amygdala, however, were notable exceptions. Whereas the concentration of [3H]DAMGO binding sites in the central nucleus of the amygdala was very low, the concentration of DAMGO‐stimulated G‐protein activation in this nucleus, as measured with [35S]GTPγS binding, was relatively high compared to other portions of the amygdala containing much higher concentrations of [3H]DAMGO binding sites. The converse was true in the medial nucleus, where high concentrations of binding sites were associated with lower levels of DAMGO‐stimulated G‐protein activation. Finally, [3H]DAMGO and [35S]GTPγS binding within the amygdala, particularly the medial nucleus, formed a continuum with the substantia innominata and bed nucleus of the stria terminalis, supporting the concept of the extended amygdala in primates. J. Comp. Neurol. 433:471–485, 2001. © 2001 Wiley‐Liss, Inc.
Cochlear electrical stimulation: Influence of age of implantation on Fos immunocytochemical reactions in inferior colliculi and dorsal cochlear nuclei of the rat
Authors: Hsu Wei‐Chung , Campos‐Torres Antonio , Portier Frederic , Lecain Eric , Van Den Abbeele Thierry , De Waele Catherine , Tran Ba Huy Patrice
Published: August 2002

The influence of age at the time of implantation of a stimulating electrode unilaterally in the inner ear on central auditory pathways was investigated in rats deafened shortly after birth. Immunoreactivity for Fos served as a functional marker of neuronal activity. Electrodes were implanted in the left cochlea of rats aged 3 weeks or 4 months. Stimulation lasted 45 minutes, then rats were sacrificed and tissues processed for immunocytochemistry. The younger animals showed significantly more neurons with Fos immunoreactivity bilaterally in the dorsal cochlear nuclei (DCN) and inferior colliculi (IC) than the older rats or control animals with normal hearing receiving the same stimulation. Activity was more prominent in the left DCN and right IC. The results show that electrical stimulation of the inner ear is more effective in younger animals in eliciting gene expression associated with development of a functional network in the auditory pathways. This suggests that deaf children should be provided with cochlear implants as early as possible. J. Comp. Neurol. 438:226–238, 2001. © 2001 Wiley‐Liss, Inc.
Three‐dimensional mapping of brain neuropils in the cockroach, Diploptera punctata
Authors: Chiang Ann‐Shyn , Liu Yee‐Chien , Chiu Shu‐Ling , Hu Shu‐Hsia , Huang Chih‐Ying , Hsieh Chang‐Huain
Published: August 2002

Herein, we present a complete three‐dimensional (3D) map of major neuropil structures in the central brain of the cockroach Diploptera punctata. The positions of the structures have been ascertained by confocal microscopy, which, until now—for reasons of tissue opacity and nonhomogeneity—has been thought impractical in imaging fluorescently labeled structures thicker than 150 μm. In this report, however, we have used digestive enzymes and microwave‐aided fixation to stain, clear, and optically section, in its entirety, an intact central brain more than 500 μm thick. The central brain from an adult female cockroach was stained thoroughly with the membrane probe NBD‐ceramide and the DNA probe propidium iodide. The central brain as well as such neuropil regions as mushroom bodies, central complex, antennal glomeruli, and lobus glomerulati were individually outlined, segmented, and reconstructed in three dimensions to a spatial resolution of approximately 1 μm in the X‐Y plane and 3 μm in the Z plane. The volume and surface area of each neuropil compartment were determined, and Kenyon cells of the mushroom bodies were counted. We determined that each brain hemisphere contains about 230,000 Kenyon cells, 99 antennal lobe glomeruli, and 40 lobus glomerulatus glomeruli. Segmented compartments were assigned as separate channels and merged into a single data base to reconstruct a 3D central brain containing eight different channels. This is the first 3D map at submicron resolution of an entire animal's brain that measures more than 500 μm in thickness. J. Comp. Neurol. 440:1–11, 2001. © 2001 Wiley‐Liss, Inc.
Immunolocalization of synaptotagmin for the study of synapses in the developing antennal lobe of Manduca sexta
Authors: Dubuque Suzanne H. , Schachtner Joachim , Nighorn Alan J. , Menon Kaushiki P. , Zinn Kai , Tolbert Leslie P.
Published: August 2002

In the mature olfactory systems of most organisms that possess a sense of smell, synapses between olfactory receptor neurons and central neurons occur in specialized neuropil structures called glomeruli. The development of olfactory glomeruli has been studied particularly heavily in the antennal lobe of the moth Manduca sexta. In the current study, we address the development of synapses within the antennal lobe of M. sexta by reporting on the localization of synaptotagmin, a ubiquitous synaptic vesicle protein, throughout development. A cDNA clone coding for M. sexta synaptotagmin was characterized and found to encode a protein that shares 67% amino acid identity with Drosophila synaptotagmin and 56% amino acid identity with human synaptotagmin I. Conservation was especially high in the C2 domains near the C‐terminus and very low near the N‐terminus. A polyclonal antiserum (MSYT) was raised against the unique N‐terminus of M. sexta synaptotagmin, and a monoclonal antibody (DSYT) was raised against the highly conserved C‐terminus of D. melanogaster synaptotagmin. In Western blot analyses, both antibodies labeled a 60 kD protein, which very likely corresponds to synaptotagmin. On sections, both antibodies labeled known synaptic neuropils in M. sexta and yielded similar labeling patterns in the developing antennal lobe. In addition, DSYT detected synaptotagmin‐like protein in three other insect species examined. Analysis of synaptotagmin labeling at the light microscopic level during development of the antennal lobe of M. sexta confirmed and extended previous electron microscopic studies. Additional synapses in the coarse neuropil and a refinement of synaptic densities in the glomeruli during the last one‐third of metamorphic development were revealed. J. Comp. Neurol. 441:277–287, 2001. © 2001 Wiley‐Liss, Inc.
Connexin expression in homotypic and heterotypic cell coupling in the developing cerebral cortex
Authors: Bittman Kevin , Becker David L. , Cicirata Federico , Parnavelas John G.
Published: August 2002

Intercellular communication through gap junction channels is a prominent feature of the developing cerebral cortex. In the first 2 weeks after birth, a time critical in the development of the rat neocortex, extensive cell coupling has been documented that diminishes as the cortex matures. Among the family of gap junction proteins, connexins 26, 36, and 43 are differentially expressed during cortical development. We used intracellular dye injections and connexin immunohistochemistry to investigate the coupling patterns and connexin expression between the different neuronal and glial cell types of the developing cortex of the rat. We found that neurons and glia couple homotypically and heterotypically at postnatal days 7 and 14. Although the prevalence of coupling was homotypic, there was considerable heterotypic coupling that involved pyramidal and nonpyramidal neurons, the principal neuronal cell types of the cortex, or neurons and astrocytes. Coupling between different cell types appeared to be mediated by differential expression of connexins 26, 36, and 43. It may be that coupling between cells in the developing neocortex is a function of the spatial and temporal expression of these and other connexin proteins. J. Comp. Neurol. 443:201–212, 2002. © 2002 Wiley‐Liss, Inc.
Evidence‐based clinical supervision: rationale and illustration
Authors: Milne Derek , Westerman Colin
Published: August 2002

The growing importance of clinical supervision makes it timely to formulate and pilot an evidence‐based approach. This entails specifying a rationale for supervision skills that is grounded in research evidence and enjoys a consensus amongst supervisors, implementing an educational system to develop those skills, and evaluating the effectiveness of this approach. The present study tackles these tasks by detailing an evidence‐based approach to clinical supervision; by implementing regular consultancy sessions to try and develop one supervisor's competence; and by evaluating (within a multiple baseline design) the effectiveness of these sessions and the clinical supervision provided to three supervisees. Based on systematic observations of 30 supervision sessions conducted over an 8‐month period, the results indicated that the consultancy led to modest improvements in the supervision. The supervision was highly rated by the supervisees throughout the study period. Implications are drawn for developing evidence‐based supervision, emphasizing the instructional and methodological components. Copyright © 2001 John Wiley & Sons, Ltd.
Simultaneous detection of bacteria expressing gfp and dsred genes with a flow cytometer
Authors: Maksimow Mikael , Hakkila Kaisa , Karp Matti , Virta Marko
Published: August 2002

Background

In this study, Escherichia coli cells producing red fluorescent protein of Discosoma sp. (drFP583 DsRed) were investigated with flow cytometry by using 488 nm excitation. We also studied whether green fluorescent protein (GFP) and drFP583 could be detected simultaneously from a single bacterial cell.

Methods

Plasmids pDsRed and pEGFP were used for the production of drFP583 and enhanced GFP, respectively, in E. coli MC1061 cells. To produce enhanced GFP and drFP583 simultaneously, plasmids pG9R and pG19R were constructed. These encode tandem fusions of enhanced GFP and drFP583 to ensure similar production levels for both proteins.

Results

Bacteria producing enhanced GFP and drFP583 were found to be brightly green and red fluorescent, respectively. Production of enhanced GFP and drFP583 fusion proteins resulted in bacteria that emitted both green and red fluorescence, which was detected easily by a flow cytometer using single laser excitation. Previously reported tetramerization of drFP583 did not restrict its use as a reporter gene, although it maturated significantly slower than enhanced GFP.

Conclusions

The results show that enhanced GFP and drFP583 proteins can be detected simultaneously from single bacteria with a standard flow cytometer with simple optical configuration. Cytometry 47:243–247, 2002. © 2002 Wiley‐Liss, Inc.
Comparative image and flow cytometric TUNEL analysis of fine needle samples of breast carcinoma
Authors: Maciorowski Zofia , Klijanienko Jerzy , Padoy Eliane , Mosseri Véronique , Fourquet Alain , Chevillard Sylvie , El‐Naggar Adel K. , Vielh Philippe
Published: August 2002

The assessment of apoptosis in solid tumors is of interest because of its biological role in tumor evolution and response to therapy. A commonly used method for apoptosis measurement is the TUNEL 3′ end‐labeling technique, which has shown wide variations in results when applied to solid tumors. Thirty‐one fine needle breast carcinoma samples were analyzed by fluorescent TUNEL assay and DNA content using image analysis and flow cytometry. TUNEL positivity, seen both in cells with apoptotic morphology and in a subset of morphologically normal cells, was categorized into five staining patterns and quantitated. Values for patterns of TUNEL‐positive cells were compared with TUNEL positivity measured by flow cytometry. Flow cytometric quantitation showed a mean of 24.3% positive cells, which correlated (P < 0.02) with total positive cells (all patterns) measured by image (22.4%). Image analysis quantitation of morphologically apoptotic cells (4.2%) did not correlate with flow cytometric TUNEL positivity and the majority of TUNEL‐stained cells were morphologically normal (17%). Image analysis allows discrimination of TUNEL‐positive morphologically apoptotic and nonapoptotic cells, which are included in the total number of TUNEL‐positive events measured by flow cytometry. Cytometry (Comm. Clin. Cytometry) 46:150–156, 2001. © 2001 Wiley‐Liss, Inc.
Immunocytochemical detection of bone marrow micrometastases in colorectal carcinoma patients, using a monoclonal antibody to villin
Authors: Rouzier Roman , Bourstyn Edwige , Grozier Frédéric , Berger Anne , Louvard Daniel , Robine Sylvie
Published: August 2002

The search continues to find methods to more effectively distinguish colorectal carcinoma patients who could be separated into high‐risk and low‐risk categories. Investigators have reported on the detection of occult micrometastases in bone marrow using antibodies to cytokeratin, which is a marker of epithelial cells but which has no tissue specificity, as opposed to villin, a cytoskeletal protein that is specifically involved in the formation of brush‐border microvilli in the small intestine and colon epithelium.

Specificity and sensitivity of antibody to villin (ID2C3) and antibody to cytokeratin (A45‐B/B3) were first studied in normal bone marrow and in a test system in which cancer cell lines were mixed in normal bone marrow. In a preliminary study including 16 colorectal carcinoma patients, we compared the number of villin‐positive cells with cytokeratin‐presenting cells.

As A45‐B/B3, ID2C3 was determined to be sensitive enough to detect one cancer cell in 106 hematopoietic cells. Staining of hematopoietic cells with irrelevant antibody and a light staining of megakaryocytes with ID2C3 limited the specificity of the method. In colorectal carcinoma patients, correlation between ID2C3 and A45‐B/B3 was 94%.

Sensitivity and specificity of ID2C3 antibody to villin were satisfactory. Its clinical relevance must be investigated in further studies. Cytometry (Comm. Clin. Cytometry) 46:281–289, 2001. © 2001 Wiley‐Liss, Inc.
Thoracic splenosis diagnosed by fine‐needle aspiration cytology: A case report
Authors: Syed Salahuddin , Zaharopoulos Paul
Published: August 2002

A case of thoracic splenosis diagnosed by fine‐needle aspiration (FNA) of subpleural lung lesions is presented. The patient, a 49‐yr‐old male with a history of gunshot wound to his trunk with splenic rupture and splenectomy several years previously, presented with recent hemoptysis and multiple subpleural solid nodules shown in the left lung field by CT scan. As the possibility of a metastatic malignancy vs. mesothelioma was entertained, an FNA was performed on one of these lesions, revealing lymphoid tissue with abundant vascularity simulating the structure of splenic tissue. In view of this finding, supported by the absence of splenic outline in the CT radiograph, the diagnosis of splenosis was made. This is the fourth reported case of thoracic splenosis in which FNA cytology was utilized for diagnosis, yet the first in which the diagnosis was based exclusively on the FNA cytologic findings. Clinical, pathologic, and diagnostic aspects of this entity are discussed. Diagn. Cytopathol. 25:321–324, 2001. © 2001 Wiley‐Liss, Inc.
Therapeutic Na+ channel blockers beneficial for pain syndromes
Authors: Wang Ging Kuo , Strichartz Gary R.
Published: August 2002

A variety of drugs are used to prevent or treat pain and many of them are known to inhibit the activity of the voltage‐gated sodium channels (VGSCs) required for neuronal excitability. In this overview, we consider the current status and future prospects for these drugs used in two contexts: local application for acute and prolonged blockade of impulses in peripheral nerve, and systemic administration for the relief of chronic pain of metabolic, neuropathic, or cancer origin. Drug Dev. Res. 54:154–158, 2002. © 2002 Wiley‐Liss, Inc.
Antiarrhythmic effects of Na‐H exchange inhibition
Authors: Karmazyn Morris
Published: August 2002

The sodium–hydrogen exchange (NHE), which extrudes protons for concomitant sodium influx, represents the primary mechanism by which the cardiac cell regulates its pH, particularly under excessive proton production. Despite this critical role, NHE, which is activated during both ischemia as well as reperfusion, has been shown to be involved in a paradoxical induction of cell injury. The mechanism for this is closely coupled to excessive sodium influx, which cannot be corrected because of ischemia‐induced inhibition of the sodium–potassium ATPase, the major pathway for sodium removal. This results in elevation in intracellular calcium concentrations through sodium–calcium exchange. Although seven NHE isoforms have thus far been identified (five cell membrane, two intracellular), the one subtype, termed NHE‐1, is the predominant isoform in the mammalian myocardium. NHE‐1‐specific inhibitors that have recently been developed, some of which are in clinical trials, have extensively demonstrated protection against ischemic and reperfusion injury as evidenced by improved function and infarct size reduction. In addition, virtually all NHE‐1 inhibitors have been demonstrated to be effective antiarrhythmic agents, and in some studies more so than classic antiarrhythmic drugs. For example, a number of studies have shown that NHE‐1 inhibitors markedly attenuate ischemia‐induced arrhythmias and can totally abolish reperfusion‐induced ventricular fibrillation. NHE‐1 inhibitors can also produce spontaneous defibrillation in a model of electrically induced cardiac arrest. As NHE is an electroneutral system, its inhibition does not directly affect cardiac electrical activity, and therefore the beneficial effects against arrhythmias likely reflect a response secondary to cardiac tissue preservation. Irrespective of precise mechanisms, NHE‐1 inhibition appears to represent an effective antiarrhythmic approach in addition to its well‐established ability to protect the ischemic and reperfused myocardium. Drug Dev. Res. 55:22–28, 2002. © 2002 Wiley‐Liss, Inc.
Ventricular fibrillation, an uncontrolled arrhythmia seeking new targets
Authors: Beatch Gregory N. , Barrett Terrance D. , Plouvier Bertrand , Jung Grace , Wall Richard A. , Zolotoy Alexander , Walker Michael J. A.
Published: August 2002

Ventricular antiarrhythmic drugs in current clinical use leave much to be desired in terms of safety and efficacy. With the exception of beta‐adrenoreceptor blockers, none of the available antiarrhythmic drugs have significantly improved survival after myocardial infarction. Amiodarone has shown marginal benefit but has several safety limitations. As a result, there is a large unmet medical need for a safe and effective drug to treat lethal ventricular arrhythmias. Despite the difficulties in developing such a drug, there are a few research programs dedicated to solving this unmet medical need. These include drugs that are targeted to the pathological substrate responsible for initiating arrhythmias and drugs that block multiple ion channels in a manner similar to amiodarone. A few research programs are directed toward other molecular targets. This article briefly reviews the active research programs in the pharmaceutical industry currently that are pursuing ventricular antiarrhythmic drugs. Drug Dev. Res. 55:45–52, 2002. © 2002 Wiley‐Liss, Inc.
Vascular effects of adenosine and its analogues
Authors: Prentice Debbie
Published: August 2002

The main action of adenosine on vascular beds is vasodilation via A2 receptors. In addition, A1 receptors are found in some blood vessels, where they cause contraction. Traditionally, adenosine‐induced vasodilation in vitro has been attributed to A2A receptor activation; however, it is now clear that A2B receptors are also involved in the regulation of vascular tone. Endothelium dependence of A2 receptor‐mediated responses is variable; in some tissues they are blocked by removal of endothelium and/or inhibition of NO‐synthase and in some they are not. In addition to A2 receptor‐mediated relaxation, there is much evidence that relaxations to adenosine and some of its analogues can also be mediated by a mechanism which cannot be blocked by adenosine receptor antagonists. There is evidence that these responses are endothelium‐ and NO‐independent and that, under conditions where adenosine is taken up into cells, relaxations to the endogenous ligand are entirely mediated by this mechanism, suggesting it is of physiological significance. Drug Dev. Res. 52:346–349, 2001. © 2001 Wiley‐Liss, Inc.
Determination of sulfur‐containing antibiotics using high‐performance liquid chromatography with integrated pulsed amperometric detection
Authors: Hanko Valoran P. , Lacourse William R. , Dasenbrock Catherine O. , Rohrer Jeffrey S.
Published: August 2002

Sulfur‐containing antibiotics (e.g., ampicillin, penicillin, lincomycin, cephalosporin, and sulfanilamide) are a general class of compounds that have antibacterial properties. Some of these antibiotics lack a strong chromophore, and consequently are poorly detected using absorbance detection. The presence of oxidizable sulfur within an antibiotic’s molecular structure allows its direct detection by pulsed amperometry. Pulsed amperometry is an electrochemical detection method that uses a pulsed potential‐time waveform at a noble metal electrode surface to electrocatalytically oxidize analytes in proportion to concentration. The current for sulfur compounds on a gold (Au) electrode is caused by the desorption of the analyte previously adsorbed at the oxide‐free Au surface. Current integration in conjunction with rapidly changed voltage potentials is termed integrated pulsed amperometric detection (IPAD). Recent publications using high‐performance liquid chromatography (HPLC) with IPAD have demonstrated the capability to measure sulfur antibiotics. Our investigations of HPLC‐IPAD showed poor long‐term peak area reproducibility for these drugs. In this article, we present a new IPAD waveform that we demonstrate has good long‐term (>2 months) peak area reproducibility (4–5% relative s.d.). We show that a broad spectrum of sulfur‐antibiotic chemical structures can be detected, and we compare IPAD to absorbance detection. For nonchromophoric sulfur‐containing antibiotics, IPAD showed greater sensitivity than absorbance detection. The lower limits of detection, linearities, and peak area precision are compared for both IPAD and absorbance detection methods using seven antibiotics representing a diversity of chemical structures, including one nonsulfur‐containing antibiotic. The stabilities of cephradine and cephapirin were monitored using both IPAD and absorbance detections. Cephradine showed high chemical stability in aqueous ambient conditions at 10 μg/ml, whereas cephapirin showed a decomposition rate of 10% per day by both detection techniques. Some decomposition products could only be detected by IPAD. High recoveries were demonstrated for two antibiotics (sulfamethoxazole and trimethoprim) in a pharmaceutical tablet formulation. For the same formulation, the feasibility of conducting a dissolution study was also demonstrated. IPAD is a good primary detection method to complement or replace absorbance detection for nonchromophoric sulfur‐containing antibiotics and their sulfur‐containing impurities and decomposition products. HPLC‐IPAD is also a good confirming technique for sulfur antibiotics with chromophoric properties, and their impurities and decomposition products. Drug Dev. Res. 53:268–280, 2001. © 2001 Wiley‐Liss, Inc.
The effects of age and sex on mental rotation performance, verbal performance, and brain electrical activity
Authors: Roberts Jonathan E. , Bell Martha Ann
Published: August 2002

This study examined the effects of age and sex on mental rotation performance, verbal performance, and brain‐wave activity. Thirty‐two 8‐year‐olds (16 boys) and 32 college students (16 men) had EEG recorded at baseline and while performing four computerized tasks: a two‐dimensional (2D) gingerbread man mental rotation, a 2D alphanumeric mental rotation, of three‐dimensional (3D) basketball player mental rotation, and lexical decision making. Additionally, participants completed a paper‐ and pencil water level task and an oral verbal fluency task. On the 2D alphanumeric and 3D basketball player mental rotation tasks, men performed better than boys, but the performance of women and girls did not differ. On the water level task, men performed better than women whereas there was no difference between boys and girls. No sex differences were found on the 2D gingerbread man mental rotation, lexical decision‐making, and verbal fluency tasks. EEG analyses indicated that men exhibited left posterior temporal activation during the 2D alphanumeric task and that men and boys both exhibited greater left parietal activation than women and girls during the 2D gingerbread man task. On the 3D basketball player mental rotation task, all participants exhibited greater activation of the right parietal area than the left parietal area. These data give insight into the brain activity and cognitive development changes that occur between childhood and adulthood. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 391–407, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10039
Higher fasting insulin but lower fasting C‐peptide levels in African Americans in the US population
Authors: Harris Maureen I. , Cowie Catherine C. , Gu Ken , Francis Mildred E. , Flegal Katherine , Eberhardt Mark S.
Published: August 2002

Background

Fasting serum insulin and fasting serum C‐peptide are risk factors for developing type 2 diabetes. Because of the higher incidence of type 2 diabetes in African Americans and Hispanic Americans, it is likely that these groups may differ from non‐Hispanic whites in their levels of insulin and C‐peptide.

Methods

We analyzed data from a nationally representative sample of adults in the US population for whom sociodemographic, clinical, and laboratory information were obtained. The data were used to describe distributions of fasting insulin and fasting C‐peptide in non‐Hispanic white, non‐Hispanic black, and Mexican American men and women aged ⩾20 years without a medical history of diabetes.

Results

Among men, Mexican Americans had higher insulin values than non‐Hispanic whites and blacks. Among women, both Mexican Americans and blacks had higher insulin values than whites. For C‐peptide, differences by sex and race‐ethnicity paralleled those seen for fasting insulin with the exception that black men had significantly lower C‐peptide values than whites and Mexican Americans. After adjustment for age, fasting plasma glucose (FPG), body mass index (BMI), and waist‐to‐hip ratio (WHR), the higher levels for insulin in blacks and Mexican Americans remained; both black men and women had significantly lower C‐peptide values than whites and Mexican Americans. The molar ratio of fasting C‐peptide to fasting insulin was similar for men and women in each race‐ethnic group. However, blacks had substantially lower ratios than whites and Mexican Americans.

Conclusions

We found wide variations in fasting insulin and fasting C‐peptide levels by race and ethnicity in US adults that were not explained by confounding factors, primarily measures of obesity. Most notably, the higher fasting insulin and lower fasting C‐peptide levels in blacks implies that there is a derangement in insulin clearance and an impairment in beta‐cell function in blacks compared with whites and Mexican Americans. Published in 2002 by John Wiley & Sons, Ltd.
Formation of supernumerary muscle spindles at the expense of golgi tendon organs in ER81‐deficient mice
Authors: Kucera J. , Cooney W. , Que A. , Szeder V. , Stancz‐Szeder H. , Walro J.
Published: August 2002

ER81, a member of the ETS family of transcription factors, is essential for the formation of connections between sensory and motor neurons in the spinal cord. Mice lacking Er81 genes exhibit reduced monosynaptic sensory‐motoneuron connectivity in response to muscle nerve stimulation. Proximal muscle nerve stimulation elicits fewer monosynaptic potentials than stimulation of distal nerves in hindlimbs, a deficit that is paralleled by a paucity of muscle spindles in proximal muscles (Arber et al., 2000). We examined whether a presence of spindles innervated by afferents in distal muscles correlated with the increased preservation of monosynaptic sensory‐motor potentials in distal muscle nerves. Not only were spindles and Ia afferents present, but also they were supernumerary in distal muscles such as the soleus, medial gastrocnemius, and extensor hallucis longus. Concomitantly, a deficiency of Golgi tendon organs (GTOs) and Ib afferents was observed in distal muscles, as if supernumerary spindles formed at the expense of tendon organs in the absence of Er81. Thus, ER81 may be involved in mechanisms that regulate acquisition of the Ia and Ib phenotypes by subsets of proprioceptive muscle afferents. Segmental differences in muscle spindle and GTO dependence on ER81 suggest that more than one ETS transcription factor may participate in the regulation of limb proprioceptive system assembly in the mouse. © 2002 Wiley‐Liss, Inc.
Protein and mRNA expression of serum and glucocorticoid‐dependent kinase 1 in metanephrogenesis
Authors: Huber Stephan M. , Friedrich Björn , Klingel Karin , Lenka Nibedita , Hescheler Jürgen , Lang Florian
Published: August 2002

Abstract

Expression of serum and glucocorticoid‐dependent kinase 1 (SGK1) during development in mouse kidney (embryonic day [E] 14 to postnatal day [P] 1) was studied by in situ hybridization and immunofluorescence. In whole embryos, SGK1 mRNA was highly abundant in the developing metanephros, where SGK1 mRNA was expressed in the ureteric buds of the branching collecting duct system and in the mesenchymal blastema‐derived comma‐ and s‐shaped bodies. In E14 kidneys, SGK1 protein was below detection level, whereas at day E16, ureteric buds, s‐shaped bodies and outgrowing loops of Henle expressed detectable amounts of SGK1 protein. SGK1 protein was also expressed in E16 primary tubules of the collecting duct system. In P1 kidneys, no or only faint SGK1 protein expression was apparent in comma‐ and s‐shaped bodies, whereas SGK1 was continuously expressed by medullary collecting ducts. In conclusion, SGK1 is developmentally expressed in metanephrogenesis. High expression in developing collecting duct and in blastema‐derived comma‐ and s‐shaped bodies suggests a dual function of SGK1 in maturation of the reabsorbing collecting duct epithelium and in epithelial transition of the blastema cells. © 2001 Wiley‐Liss, Inc.
Optimum design for residential photovoltaic‐thermal binary utilization system by minimizing auxiliary energy
Authors: Fujisawa Toru , Tani Tatsuo
Published: August 2002

Possible designs for a self‐sufficient residential binary solar energy include a side‐by‐side system, a PVT hybrid system, and a side‐by‐side PVT hybrid system. We designed and performed an annual performance simulation of three systems: PV with flat plate collector (PV/FPC), photovoltaic‐thermal hybrid (PVT), and PV with photovoltaic‐thermal hybrid (PV/PVT) including an electrical auxiliary heat pump. In this paper, the solar energy fraction (SEF) or auxiliary energy fraction (AUX) is used as a figure of merit for system evaluation. These indices are shown to be affected by the COP (coefficient of performance) of AUX and by the ratio of the DHW (domestic hot water) load to the annual synthetic load.

The best results were achieved by the side‐by‐side PV/PVT hybrid system. Using PVT with PV leads to an improvement of the SEF or AEF compared with the PVT system alone. Glazing is found to be indispensable for the PV/PVT system with an AUX COP of 1, but is unnecessary for a PV/PVT system with a higher COP. © 2001 Scripta Technica, Electr Eng Jpn, 137(1): 28–35, 2001
Why do cells have multiple error‐prone DNA polymerases?
Authors: Friedberg Errol C.
Published: August 2002

Recent years have witnessed the emergence of a plethora of so‐called novel DNA polymerases in both eukaryotic and prokaryotic cells. Many of these DNA polymerases are characterized by poor replicational fidelity and low processivity, and are devoid of 3′ → 5′ exonuclease activity. This article describes the discovery of these error‐prone polymerases and what is known about their biological function. Environ. Mol. Mutagen. 38:105–110, 2001. © 2001 Wiley‐Liss, Inc.
Three‐dimensional dynamic response of underground openings in saturated rock masses
Authors: Kim Sun‐Hoon , Kim Kwang‐Jin
Published: August 2002

In this paper a three‐dimensional dynamic analysis program for saturated porous rocks and soils is presented. The theoretical formulations incorporated in the proposed computer program are the extension of Biot's two‐phase theory to non‐linear region. Numerical study using the program is carried out to demonstrate the three‐dimensional features of the program and to show the effects of pore water on the dynamic response of underground openings in saturated rock masses. It is shown that underground openings in saturated porous media could be significantly more vulnerable to the potential damages associated with high motions and shear failure than those in dry media. Copyright © 2001 John Wiley & Sons, Ltd.
Sampling‐surface orientation and clast macrofabric in periglacial colluvium
Authors: Millar Susan W. S. , Nelson Frederick E.
Published: August 2002

To isolate the influence of sampling‐surface orientation on the macrofabric of periglacial colluvial deposits, clast orientation measurements were obtained from seven paired horizontal and vertical exposures in turf‐banked solifluction lobes on Niwot Ridge, Colorado Front Range. Most samples form moderately strong, upslope‐plunging clusters aligned with the local slope orientation. Fabrics obtained from vertical faces were stronger than those from horizontal exposures in six of the pairs. Near‐horizontal sampling surfaces yield less biased results than vertical exposures, owing to operator perceptions, procedural difficulties, and the relative thinness of the layer affected by colluvial processes. Sampling procedures must be standardized before comparative studies of colluvium can yield reliable results. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical analysis of interfacial two‐dimensional Stokes flow with discontinuous viscosity and variable surface tension
Authors: Li Zhilin , Lubkin Sharon R.
Published: August 2002

A fluid model of the incompressible Stokes equations in two space dimensions is used to simulate the motion of a droplet boundary separating two fluids with unequal viscosity and variable surface tension. Our theoretical analysis leads to decoupled jump conditions that are used in constructing the numerical algorithm. Numerical results agree with others in the literature and include some new findings that may apply to processes similar to cell cleavage. The method developed here accurately preserves area for our test problems. Some interesting observations are obtained with different choices of the parameters. Copyright © 2001 John Wiley & Sons, Ltd.
Cre/loxP recombination‐activated neuronal markers in mouse neocortex and hippocampus
Authors: Huang Z. Josh , Yu Wenjiang , Lovett Chanel , Tonegawa Susumu
Published: August 2002

A new strategy for visualizing neuronal cell morphology of mouse brain based on Cre/loxP recombination‐activated gene expression is described. A “reporter” transgenic line was generated which expressed a fusion gene encoding a dendrite‐targeted green fluorescent protein (MAP2‐GFP) upon deletion of a transcription/translation STOP (transcription and translation stop signal) cassette. Cre transgenic “deleter” lines were established that activated reporter gene expression at various frequencies in pyramidal neurons in the forebrain. A deleter line was identified which activated a MAP2‐GFP reporter gene at very low frequency (less than 0.1% of pyramidal neurons) and allowed the visualization of dendritic structures of individual neocortical and hippocampal pyramidal neurons. In addition, vertical “columns” of pyramidal neurons in the neocortex were labeled in these mice. In a second deleter line, a MAP2‐GFP reporter gene was selectively activated in pyramidal neurons of the CA‐1 subregion of the hippocampus in young mice. With its combinatorial property, this binary recombination‐activated neuronal marker system should facilitate the study of detailed morphology, connectivity, and plasticity of defined classes of live neurons in vitro and in vivo. genesis 32:209–217, 2002. © 2002 Wiley‐Liss, Inc.