bluuebunny/crossref_metadata_2025 huggingface dataset:
Projections of the posterodorsal preoptic nucleus and the lateral part of the posterodorsal medial amygdala in male gerbils, with emphasis on cells activated with ejaculation
Authors: Simmons Danielle A. , Yahr Pauline
Published: August 2002

The posterodorsal preoptic nucleus (PdPN) and the lateral part of the posterodorsal medial amygdala (MeApd) express Fos with ejaculation in male gerbils. Ejaculation‐activated cells participate in the PdPN and MeApd projections to each other and to the sexually dimorphic preoptic area (SDA), but those projections involve less than 20% of the activated PdPN cells and less than 50% of the activated MeApd cells. To identify other potential targets of ejaculation‐activated cells, we traced PdPN and lateral MeApd outputs using biotinylated dextran amine. The principal part of the bed nucleus of the stria terminalis (BSTpr) and the anteroventral periventricular nucleus (AVPv) were labeled from both sites and were injected with Fluoro‐Gold to determine whether PdPN and lateral MeApd cells that express Fos with ejaculation would be retrogradely labeled. Fluoro‐Gold was also applied to the dorsomedial hypothalamus (DMH) and retrorubral field (RRF) because such injections label PdPN cells in rats. The PdPN‐DMH projection is minimal in gerbils, involving few, if any, ejaculation‐related cells. Ejaculation‐activated PdPN cells project to the AVPv (43%), dorsal BSTpr (30%), and RRF (12%). Those in the lateral MeApd project to the dorsal BSTpr (43%) and AVPv (18%). When these percentages are combined with those for ejaculation‐activated cells involved in the PdPN and lateral MeApd projections to each other and to the medial SDA, the totals reach 100%. Thus, every PdPN and MeApd cell activated with ejaculation may participate in one of these projections. Similar projections may contribute to the similar behavioral effects of the PdPN and MeApd. J. Comp. Neurol. 444:75–94, 2002. © 2002 Wiley‐Liss, Inc.
Synaptic organization of the mushroom body calyx in Drosophila melanogaster
Authors: Yasuyama Kouji , Meinertzhagen Ian A. , Schürmann Friedrich‐Wilhelm
Published: August 2002

The calyx neuropil of the mushroom body in adult Drosophila melanogaster contains three major neuronal elements: extrinsic projection neurons, presumed cholinergic, immunoreactive to choline acetyltransferase (ChAT‐ir) and vesicular acetylcholine transporter (VAChT‐ir) antisera; presumed γ‐aminobutyric acid (GABA)ergic extrinsic neurons with GABA‐like immunoreactivity; and local intrinsic Kenyon cells. The projection neurons connecting the calyx with the antennal lobe via the antennocerebral tract are the only source of cholinergic elements in the calyces. Their terminals establish an array of large boutons 2–7 μm in diameter throughout all calycal subdivisions. The GABA‐ir extrinsic neurons, different in origin, form a network of fine fibers and boutons codistributed in all calycal regions with the cholinergic terminals and with tiny profiles, mainly Kenyon cell dendrites. We have investigated the synaptic circuits of these three neuron types using preembedding immuno‐electron microscopy. All ChAT/VAChT‐ir boutons form divergent synapses upon multitudinous surrounding Kenyon cell dendrites. GABA‐ir elements also regularly contribute divergent synaptic input onto these dendrites, as well as occasional inputs to boutons of projection neurons. The same synaptic microcircuits involving these three neuron types are repeatedly established in glomeruli in all calycal regions. Each glomerulus comprises a large cholinergic bouton at its core, encircled by tiny vesicle‐free Kenyon cell dendrites as well as by a number of GABAergic terminals. A single dendritic profile may thereby receive synaptic input from both cholinergic and GABAergic elements in close vicinity at presynaptic sites with T‐bars typical of fly synapses. ChAT‐ir boutons regularly have large extensions of the active zones. Thus, Kenyon cells may receive major excitatory input from cholinergic boutons and considerable postsynaptic inhibition from GABAergic terminals, as well as, more rarely, presynaptic inhibitory signaling. The calycal glomeruli of Drosophila are compared with the cerebellar glomeruli of vertebrates. The cholinergic boutons are the largest identified cholinergic synapses in the Drosophila brain and an eligible prospect for studying the genetic regulation of excitatory presynaptic function. J. Comp. Neurol. 445:211–226, 2002. © 2002 Wiley‐Liss, Inc.
Vesicular γ‐aminobutyric acid transporter expression in amacrine and horizontal cells
Authors: Cueva Juan G. , Haverkamp Silke , Reimer Richard J. , Edwards Robert , Wässle Heinz , Brecha Nicholas C.
Published: August 2002

The vesicular γ‐aminobutyric acid (GABA) transporter (VGAT), which transports the inhibitory amino acid transmitters GABA and glycine, is localized to synaptic vesicles in axon terminals. The localization of VGAT immunoreactivity to mouse and rat retina was evaluated with light and electron microscopy by using well‐characterized VGAT antibodies. Specific VGAT immunoreactivity was localized to numerous varicose processes in all laminae of the inner plexiform layer (IPL) and to the outer plexiform layer (OPL). Amacrine cell somata characterized by weak VGAT immunoreactivity in the cytoplasm were located in the ganglion cell layer and proximal inner nuclear layer (INL) adjacent to the IPL. In rat retina, VGAT‐immunoreactive cell bodies also contained GABA, glycine, or parvalbumin (PV) immunoreactivity, suggesting vesicular uptake of GABA or glycine by these cells. A few varicose VGAT‐immunoreactive processes entered the OPL from the IPL. VGAT immunoreactivity in the OPL was predominantly localized to horizontal cell processes. VGAT and calcium binding protein‐28K immunoreactivities (CaBP; a marker for horizontal cells) were colocalized in processes and terminals distributed to the OPL. Furthermore, VGAT immunoreactivity overlapped or was immediately adjacent to postsynaptic density‐95 (PSD‐95) immunoreactivity, which is prominent in photoreceptor terminals. Preembedding immunoelectron microscopy of mouse and rat retinae showed that VGAT immunoreactivity was localized to horizontal cell processes and their terminals. Immunoreactivity was distributed throughout the cytoplasm of the horizontal cell processes. Taken together, these findings demonstrate VGAT immunoreactivity in both amacrine and horizontal cell processes, suggesting these cells contain vesicles that accumulate GABA and glycine, possibly for vesicular release. J. Comp. Neurol. 445:227–237, 2002. © 2002 Wiley‐Liss, Inc.
Distribution of calcitonin gene‐related peptide‐like immunoreactivity in the brain of the lizard Podarcis hispanica
Authors: Martínez‐García Fernando , Novejarque Amparo , Landete José M. , Moncho‐Bogani Jose , Lanuza Enrique
Published: August 2002

The present work studies the distribution of calcitonin gene‐related peptide‐immunoreactive (CGRP‐li) neurons and fibers in the brain of a reptile, the lizard Podarcis hispanica. CGRP‐li perikarya were not present in the telencephalon. In the thalamus, CGRP‐li perikarya were restricted to the posteromedial and posterolateral nuclei. In the hypothalamus, CGRP‐li cells were found mainly in the supramammillary and mammillary nuclei. In the midbrain and brainstem, CGRP‐li cells appeared in the ventral tegmental area, the parabrachial nucleus, and the motor nuclei of the III–VII, IX, X, and XII cranial nerves. Motoneurons of the ventral horn of the spinal cord were also immunoreactive for CGRP. CGRP‐li fibers were seen in the telencephalic hemispheres, where a dense plexus of reactive fibers appeared in the septum and in the lateral striatoamygdaloid transition area. From the latter, CGRP‐li fibers entered the posterior dorsal ventricular ridge, the cell layer and deep stratum of the ventral lateral cortex, and various amygdaloid nuclei. Parts of the striatum (nucleus accumbens) and pallidum also displayed CGRP‐li innervation. In the diencephalon, CGRP‐li innervation was observed in parts of the dorsal thalamus and in the periventricular and medial hypothalamus. The pretectum and deep layers of the optic tectum also showed CGRP‐li fibers, and numerous CGRP‐li fibers were observed in the midbrain central gray, tegmentum, and pons. Some of the sensory fibers of the trigeminal, vagal, and spinal nerves were also CGRP‐li. These results show that the distribution of CGRP‐li structures in the reptilian brain is similar to that described for other vertebrates and suggest that the thalamotelencephalic CGRPergic projections appear to be conserved among amniote vertebrates. J. Comp. Neurol. 447:99–113, 2002. © 2002 Wiley‐Liss, Inc.
Developmental timing of hair follicle and dorsal skin innervation in mice
Authors: Peters Eva M.J. , Botchkarev Vladimir A. , Müller‐Röver Sven , Moll Ingrid , Rice Frank L. , Paus Ralf
Published: August 2002

The innervation of hair follicles offers an intriguing, yet hardly studied model for the dissection of the stepwise innervation during cutaneous morphogenesis. We have used immunofluorescence and a panel of neuronal markers to characterize the developmental choreography of C57BL/6 mouse backskin innervation. The development of murine skin innervation occurs in successive waves. The first cutaneous nerve fibers appeared before any morphological evidence of hair follicle development at embryonic day 15 (E15). Stage 1 and 2 developing hair follicles were already associated with nerve fibers at E16. These fibers approached a location where later in development the follicular (neural) network A (FNA) is located on fully developed pelage hair follicles. Prior to birth (E18), some nerve fibers had penetrated the epidermis, and an additional set of perifollicular nerve fibers arranged itself around the isthmus and bulge region of stage 5 hair follicles, to develop into the follicular (neural) network B (FNB). By the day of birth (P1), the neuropeptides substance P and calcitonin gene‐related peptide became detectable in subcutaneous and dermal nerve fibers first. Newly formed hair follicles on E18 and P1 displayed the same innervation pattern seen in the first wave of hair follicle development. Just prior to epidermal penetration of hair shafts (P5), peptide histidine methionine‐IR nerve fibers became detectable and epidermal innervation peaked; such innervation decreased after penetration (P7– P17). Last, tyrosine hydroxylase‐IR and neuropeptide Y‐IR became readily detectable. This sequence of developing innervation consistently correlates with hair follicle development, indicating a close interdependence of neuronal and epithelial morphogenesis. J. Comp. Neurol. 448:28–52, 2002. © 2002 Wiley‐Liss, Inc.
Development of tyrosine hydroxylase‐immunoreactive systems in the brain of the larval lamprey Lampetra fluviatilis
Authors: Pierre‐Simons Jacqueline , Repérant Jacques , Mahouche Mohamed , Ward Roger
Published: August 2002

The development of the catecholaminergic system of the brain of the lamprey (Lampetra fluviatilis) was studied with immunocytochemistry in a series of larvae of different sizes by using two different antibodies directed against tyrosine hydroxylase (TH), the rate‐limiting enzyme of catecholamine synthesis. In group 1 larvae (length: 29–54 mm, ages: 8 months to 1.5 years), the only TH‐immunoreactive somata observed were located in the caudal wall of the recessus praeopticus (RP) and in the nucleus tuberculi posterioris (NTP). In group 2 larvae (length: 55–80 mm, ages: 1.5–2.5 years), the somata of immunolabeled cells of the NTP give rise to fibers, most of which are ascending and terminate in the corpus striatum. Additional immunoreactive cells are observed in the nucleus praeopticus (NP), which has differentiated, and in the spinal cord. In group 3 larvae (length: 81–110 mm, ages: 2.5–4 years), the spatial distribution of TH‐immunoreactive elements (somata, fibers, and terminals) bears many resemblances to that seen in the adult. Immunolabeled cells may be observed in the olfactory bulb, in the nucleus commissurae postopticae (NCP), and in the nucleus dorsalis hypothalami (NDH). Nevertheless, some groups of TH‐immunoreactive cells found in the adult are not observed in group 3 larvae; these may appear during the metamorphic phase. By comparative analysis, we show that, in spite of several differences, the spatiotemporal sequence of appearance of TH‐immunoreactive cell bodies and fibers in the lamprey presents many similarities to that described in gnathostomes. J. Comp. Neurol. 447:163–176, 2002. © 2002 Wiley‐Liss, Inc.
Distribution of preproadrenomedullin mRNA in the rat central nervous system and its modulation by physiological stressors
Authors: Shan Jing , Krukoff Teresa L.
Published: August 2002

Adrenomedullin (ADM), encoded by the preproadrenomedullin (ppADM) gene, exerts multiple effects in a wide variety of peripheral and central tissues. Although ADM‐like immunoreactivity has been shown to be widely distributed throughout the rat central nervous system (CNS), the detailed distribution of ppADM gene expression in the CNS and its modulation by physiological stimuli remain unknown. In our study, in situ hybridization was used to localize ppADM mRNA in the rat brain and to quantify its levels after exposure to different stressors including lipopolysaccharide (LPS; 100 μg/kg, iv), restraint stress (2 cycles of 1 hour restraint/1 hour rest), and 24 hours of dehydration. In addition, Fos immunoreactivity was used to identify the activation of neurons in response to LPS. Our results show that ppADM mRNA is widely distributed throughout the rat CNS, with especially high levels in autonomic centers including the hypothalamic paraventricular nucleus (PVN), hypothalamic supraoptic nucleus (SON), locus coeruleus, ventrolateral medulla, and intermediolateral cell column of the spinal cord. Furthermore, LPS inhibits ppADM gene expression in the parvocellular PVN (pPVN), magnocellular PVN (mPVN), SON, dorsal motor nucleus of the vagus, and area postrema among examined regions; restraint stress reduces ppADM mRNA levels in the pPVN, mPVN, SON, nucleus of the solitary tract, dorsal motor nucleus of the vagus, area postrema, and subfornical organ; 24 hours of water deprivation decreases ppADM gene expression only in the mPVN and SON. Taken together, our results suggest that ADM is involved in the regulation of the hypothalamo‐neurohypophysial system, the hypothalamo‐pituitary‐adrenal axis, and central autonomic functions. J. Comp. Neurol. 432:88–100, 2001. © 2001 Wiley‐Liss, Inc.
Projections from the amygdalo‐piriform transition area to the amygdaloid complex: A PHA‐l study in rat
Authors: Jolkkonen Esa , Miettinen Riita , Pitkänen Asla
Published: August 2002

The amygdalo‐piriform transition area is a poorly defined region in the temporal lobe that is heavily connected with the olfactory system. As part of an ongoing project aimed at understanding the neuronal pathways that provide sensory information to the amygdala, we investigated the cytoarchitectonic and chemoarchitectonic features of the amygdalo‐piriform transition area and its connections to the amygdaloid complex in 13 rats by using the anterograde tracer,Phaseolus vulgaris‐leucoagglutinin. Our analysis indicates that the amygdalo‐piriform transition area has medial (rostral and caudal portions) and lateral parts. The rostromedial part projects heavily to the intermediate and lateral divisions of the central nucleus, whereas the caudomedial part projects mainly to the medial division. The lateral part of the amygdalo‐piriform transition area projects heavily to the capsular and lateral divisions of the central nucleus. Electron microscopic analysis revealed that the projection to the lateral division of the central nucleus forms asymmetric contacts with the spines and shafts of postsynaptic neurons and, therefore, is assumed to be excitatory. The amygdalo‐piriform transition area also projects moderately to other amygdaloid nuclei, including the parvicellular division of the basal nucleus, the anterior cortical nucleus, and the nucleus of the lateral olfactory tract. The lateral and medial parts of the amygdalo‐piriform transition area also project to the distal temporal CA1 and distal temporal subiculum, respectively. Unlike the adjacent entorhinal cortex, the amygdalo‐piriform transition area does not project to the dentate gyrus. These data suggest that the amygdalo‐piriform transition area is a region that influences both emotional and memory processing in parallel by means of pathways to the amygdala and the hippocampus, respectively. J. Comp. Neurol. 432:440–465, 2001. © 2001 Wiley‐Liss, Inc.
Pyramidal cell axons show a local specialization for GABA and 5‐HT inputs in monkey and human cerebral cortex
Authors: DeFelipe Javier , Arellano Jon I. , Gómez Antonio , Azmitia Efrain C. , Muñoz Alberto
Published: August 2002

Various mechanisms are thought to control excitation of pyramidal cells of the cerebral cortex. With immunocytochemical methods, we found that the proximal portions of numerous pyramidal cell axons (Pyr‐axons) in the human and monkey neocortex are immunoreactive for the serotonin (5‐HT) receptor 5‐HT‐1A. With double‐labeling experiments and confocal laser microscopy, we found that most (93.4%) of the 5‐HT1A–immunoreactive Pyr‐axons present in layers II and III were innervated by parvalbumin‐immunoreactive chandelier cell axon terminals. In addition, Pyr‐axons were compartmentalized: 5‐HT‐1A receptors were found proximal to inputs from chandelier cells. Although we found close appositions between GABAergic chandelier cell axon terminals and Pyr‐axons, suggesting synaptic connections, we did not observe 5‐HT–immunoreactive fibers in close proximity to the Pyr‐axons. These results suggested that Pyr‐axons are under the influence of 5‐HT in a paracrine manner (via 5‐HT‐1A receptors) and, more distally, are under the influence of γ‐aminobutyric acid (GABA) in a synaptic manner (through the axons of chandelier cells). The local axonal specialization might represent a powerful inhibitory mechanism by which the responses of large populations of pyramidal cells can be globally controlled by subcortical serotonin afferents, in addition to local inputs from GABAergic interneurons. J. Comp. Neurol. 433:148–155, 2001. © 2001 Wiley‐Liss, Inc.
Heparan sulfate proteoglycan expression in the optic chiasm of mouse embryos
Authors: Chung Kit‐Ying , Leung Kin‐Mei , Lin Ling , Chan Sun‐On
Published: August 2002

Previous studies have demonstrated that heparan sulfate (HS) proteoglycans (PGs) regulate neurite outgrowth through binding to a variety of cell surface molecules, extracellular matrix proteins, and growth factors. The present study investigated the possible involvement of HS‐PGs in retinal axon growth by examining its expression in the retinofugal pathway of mouse embryos by using a monoclonal antibody against the HS epitope. Immunoreactive HS was first detected in all regions of the retina at embryonic day (E) 11. The staining was gradually lost in the central regions and restricted to the retinal periphery at later developmental stages (E12–E16). Prominent staining for HS was consistently found in the retinal fiber layer and at the optic disk, indicating a possible supportive role of HS‐PGs in axon growth in the retina. At the ventral diencephalon, immunostaining for HS was first detected at E12, before arrival of any retinal axons. The staining matched closely the neurons that are immunopositive for the stage‐specific embryonic antigen 1 (SSEA‐1). At E13 to E16, when axons are actively exploring their paths across the chiasm, immunoreactivity for HS was particularly intense at the midline. This characteristic expression pattern suggests a role for HS‐PGs in defining the path of early axons in the chiasm and in regulating development of axon divergence at the midline. Furthermore, HS immunoreactivity is substantially reduced at regions flanking both sides of the midline, which coincides spatially to the position of actin‐rich growth cones from subpial surface to the deep regions of the optic axon layer at the chiasm. Moreover, at the threshold of the optic tract, immunoreactive HS was localized to deep parts of the fiber layer. These findings indicate that changes in age‐related fiber order in the optic chiasm and optic tract of mouse embryos are possibly regulated by a spatially restricted expression of HS‐PGs. J. Comp. Neurol. 436:236–247, 2001. © 2001 Wiley‐Liss, Inc.
A confocal study of spinal interneurons in living larval zebrafish
Authors: Hale Melina E. , Ritter Dale A. , Fetcho Joseph R.
Published: August 2002

We used confocal microscopy to examine the morphology of spinal interneurons in living larval zebrafish with the aim of providing a morphological foundation for generating functional hypotheses. Interneurons were retrogradely labeled by injections of fluorescent dextrans into the spinal cord, and the three‐dimensional morphology of living cells was reconstructed from confocal optical sections through the transparent fish. At least eight types of interneurons are present in the spinal cord of larval zebrafish; four of these are described here for the first time. The newly discovered cell types include classes of commissural neurons with axons that ascend, descend, and bifurcate in the contralateral spinal cord. Our reexamination of previously described cell types revealed functionally relevant features of their morphology, such as undescribed commissural axons, as well as the relationships between the trajectories of the axons of interneurons and the descending Mauthner axons. In addition to describing neurons, we surveyed their morphology at multiple positions along the spinal cord and found longitudinal changes in their distribution and sizes. For example, some cell types increase in size from rostral to caudal, whereas others decrease. Our observations lead to predictions of the roles of some of these interneurons in motor circuits. These predictions can be tested with the combination of functional imaging, single‐cell ablation, and genetic approaches that make zebrafish a powerful model system for studying neuronal circuits. J. Comp. Neurol. 437:1–16, 2001. © 2001 Wiley‐Liss, Inc.
Rhombomeric organization of vestibular pathways in larval frogs
Authors: Straka Hans , Baker Robert , Gilland Edwin
Published: August 2002

Rhombencephalic subnuclei and projection pathways related to vestibular function were mapped in larval ranid frogs. The retention of overt postembryonic rhombomeres (r) allowed direct visualization of the locations of neurons retrogradely labeled with fluorescent dextran amines from the midbrain oculomotor complex, cerebellum, vestibular nuclei, and spinal cord. Oculomotor projecting vestibular neurons were mainly located in bilateral r1/2, ipsilateral r3, and contralateral r5–8, and spinal projecting vestibular neurons mainly in ipsilateral r4 and contralateral r5. Vestibular commissural neurons were located in r1–3 and r5–7 and were largely excluded from r4. Cerebellar projecting neurons included contralateral inferior olivary neurons in r8 and vestibular neurons in bilateral r6/7 and contralateral r1/2. Mapping these results onto adult anuran vestibular organization indicates that the superior vestibular nucleus derives from larval r1/2, the lateral vestibular nucleus from r3/4, and the major portions of the medial and descending vestibular nuclei from r5–8. The lateral vestibulospinal tract projects from an origin in r4, whereas a possible ascending tract of Deiters arises in r3. Rhombomere 5 contains a nuclear group that appears homologous to the tangential nucleus of fish, reptiles, and birds and thus likely serves gravistatic and linear vestibulomotor reflexes. Comparisons between frogs and other vertebrates suggest that vestibular neurons performing similar computational roles during head movements originate from the same segmental locations in different species. J. Comp. Neurol. 437:42–55, 2001. © 2001 Wiley‐Liss, Inc.
Color harmony
Authors: Burchett Kenneth E.
Published: August 2002

Colors seen together to produce a pleasing affective response are said to be in harmony. The term color harmony is not, however, a concise, descriptive term; rather, it is one with a wide range of meanings because of any or all of several conditional attributes. A content analysis was done on a selection of books from color science, art and design, color theory, and psychology. The study identified key attributes and related terms consistently used to describe color harmony. Categories of terms found to be coincidental with the discussion of color harmony were order, tone, configuration, interaction, similarity, association, attitude, and area. © 2002 John Wiley & Sons, Inc. Col Res Appl, 27, 28–31, 2002
Measurement of nuclear factor‐kappa B translocation on lipopolysaccharide‐activated human dendritic cells by confocal microscopy and flow cytometry
Authors: Blaecke Aline , Delneste Yves , Herbault Nathalie , Jeannin Pascale , Bonnefoy Jean‐Yves , Beck Alain , Aubry Jean‐Pierre
Published: August 2002

Background

Nuclear factor kappa B (NF‐κB) is a ubiquitously expressed transcription factor that regulates cytokine and immunoglobulin (Ig) gene expression. In most cell types, the inactive p50/p65 NF‐κB heterodimer is located in the cytoplasm, complexed to its IκB inhibitory unit. Stimulation of cells by various reagents such as bacterial endotoxin or cytokines leads to a dissociation of NF‐κB from IκB and a rapid translocation of free NF‐κB to the nucleus. The aim of this article is to define optimal conditions for the measurement of NF‐κB translocation by both confocal microscopy and flow cytometry.

Methods

Four commercial anti–NF‐κB antibodies were evaluated by confocal microscopy, after using two methods of fixation and permeabilization of the cells. These antibodies were examined further by flow cytometry on purified nuclei.

Results

Paraformaldehyde‐methanol treatment of dendritic cells is a good combination to visualize NF‐κB translocation by confocal microscopy. Three of the four antibodies tested gave good results on nonactivated and on lipopolysaccharide (LPS)‐activated dendritic cells. The measurement of NF‐κB translocation by flow cytometry on purified nuclei is a quick and sensitive method. Only one of the four evaluated antibodies showed a significant difference between nonactivated and activated cells.

Conclusions

Microscopy and flow cytometry are quick and reproducible methods to measure NF‐κB translocation and can be adapted to identify new molecules that activate dendritic cells. Cytometry 48:71–79, 2002. © 2002 Wiley‐Liss, Inc.
Optical compartmentation of vegetating algae species as a basis for their growth‐specific characterization
Authors: Gerashchenko Bogdan I. , Kosaka Toshikazu , Hosoya Hiroshi
Published: August 2002

Background

The number of microalgal strains known to date is enormous and continuously growing, and their characterization accordingly requires quick and reliable methodologies.

Methods

Asynchronously growing logarithmic (3‐ and 6‐day cultures) and stationary (9‐day cultures) phase cell populations of two algae species that are difficult to distinguish microscopically (one Chlorella sp., C. vulgaris [c‐27], and another that might belong to the same genus, SA‐3 algae exsymbiotic from Paramecium bursaria) were characterized by means of flow cytometry (FCM). Forward light scatter (FSC) of algae was monitored in association with their 90° side light scatter (SSC) and fluorescence of endogenous chlorophyll (FL3‐height).

Results

Two‐parameter FSC versus SSC and FSC versus FL3‐height plots distinctly showed growth‐specific compartmentation of algae into discrete cell subpopulations staying at a particular stage of the life cycle, and numbers of cells constituting these subpopulations could be quantitated. The growth pattern of C. vulgaris (c‐27) differed substantially from that of SA‐3 algae, particularly in the late‐logarithmic (6‐day) cultures. At this phase of growth, C. vulgaris (c‐27) cells compartmentalized into three subpopulations, whereas SA‐3 cells compartmentalized into two subpopulations. Different compartmentations of optical signals from late‐logarithmic phase SA‐3 algae and C. vulgaris (c‐27) likely were caused by the differences in timing of the life cycle stages of these types of cells.

Conclusions

Growth‐specific compartmentation of vegetating microalgae by FCM provides a good basis for characterization of morphologically similar algae species. Because algae are also present in symbiotic relationships with other organisms, this tool might be of potential interest for the study of symbiosis mechanisms. Cytometry 48:153–158, 2002. © 2002 Wiley‐Liss, Inc.
Variations of components of the plasminogen activation system with the cell cycle in benign prostate tissue and prostate cancer
Authors: Plas Eugen , Carroll Veronica A. , Jilch Ruth , Simak Rainer , Mihaly Judith , Melchior Sebastian , Thüroff Joachim W. , Binder Bernd R. , Pflüger Heinz
Published: August 2002

Background: Components of the fibrinolytic system are involved in tumor cell invasion and metastasis. Previous investigations suggested a cell cycle‐dependent expression of urokinase‐type plasminogen activator (u‐PA) in epithelial cells. In order to determine a correlation of cell cycle phases with the fibrinolytic system, we investigated the expression of u‐PA, tissue‐type plasminogen activator (t‐PA), and plasminogen activator inhibitor type 1 (PAI‐1) in normal and tumor‐containing prostate extracts and analyzed a possible relationship with flow cytometry‐determined proliferative activity of the samples. Cell cycle phases were correlated with fibrinolytic parameters in prostate tissue. Methods: Samples were obtained from patients undergoing radical prostatectomy for prostate cancer and separated into two portions for DNA analysis and the detection of u‐PA, t‐PA, and PAI‐1. Flow cytometric analysis was performed according to the Vindelov technique. The concentrations of u‐PA, t‐PA, and PAI‐1 were determined from tissue extracts after homogenization by an enzyme‐linked immunosorbent assay (ELISA) technique. Results: Correlations of u‐PA and t‐PA expression with the frequency of G0/G1, S, G2M, S‐phase fraction (SPF), and proliferation index (PI) for normal prostate and prostate cancer revealed no significant correlation. The only significant finding was observed in normal tissue revealing a positive correlation between PAI‐1 expression and G0/G1 and a negative correlation with S‐phase, SPF, and PI. No dependence of PAI‐1 expression on different cell phases was found in prostate cancer. Furthermore, no significant correlation of u‐PA, t‐PA, and PAI‐1 with cell cycles in organ‐confined (<pT3a) and disseminated (≥pT3a) tumors was found. No significant correlation in prostate cancer of components of the fibrinolytic system differentiated according to tumor grade or perineural tumor infiltration and cell cycle analysis was found. Only in highly differentiated G1 (Gleason 2–4) cancer, u‐PA had a significant positive correlation with G2M‐phase. Conclusion: Absence of a correlation between levels of components of the fibrinolytic system and cell cycle phases suggests that the reported association between increases of some of these components and aggressive biological behavior of prostate cancer is secondary to non–cell cycle‐related mechanisms. Cytometry (Comm. Clin. Cytometry) 46:184–189, 2001. © 2001 Wiley‐Liss, Inc.
Interaction of nocodazole with tubulin isotypes
Authors: Xu Keliang , Schwarz Patricia M. , Ludueña Richard F.
Published: August 2002

Nocodazole is an anti‐mitotic drug that has long been used as an experimental tool in cell biology. Although nocodazole is known to bind with high affinity to tubulin and to inhibit microtubule assembly, very little has been done on its precise mechanism of action. In fact, its binding to the different isotypes of tubulin has never been addressed. Although the nocodazole binding site overlaps with that of colchicine, the two drugs are structurally quite different. The tubulin molecule is an α/β heterodimer; both α and β exist as various isotypes whose distribution and drug‐binding properties are significantly different. In this study, we measured the binding affinity of nocodazole for purified tubulin isotypes. Using fluorescence quenching analysis, we found that the binding kinetics of nocodazole with each type of tubulin best fits a two‐affinity Michaelis‐Menten binding model. The apparent dissociation constants for the high‐affinity binding sites are 0.52 ± 0.02 for αβII, 1.54 ± 0.29 for αβIII, and 0.29 ± 0.04 for αβIV. Thus, nocodazole has the highest affinity for αβIV and the lowest affinity for αβIII. Knowledge of the isotype specificity of nocodazole may allow for development of novel therapeutic agents based on this drug. Drug Dev. Res. 55:91–96, 2002. © 2002 Wiley‐Liss, Inc.
Facilitating postural control: Effects on the reaching behavior of 6‐month‐old infants
Authors: Hopkins Brian , Rönnqvist Louise
Published: August 2002

In this study, 3‐D kinematic as well as 2‐D videorecordings were made of the reaching behavior of infants aged about 6 months who were not yet able to sit. Detailed analyses of these recordings were directed toward specifying the effects of providing additional postural support to the lower body on the spatial and temporal features of such behavior. To detect these effects, reaching and associated head movements in this modified condition were compared to those made while the infants sat in an age‐appropriate and commercially available chair lacking the supplementation of support for the pelvic region and upper legs. Findings consistent with predictions included better head stabilization and smoother reaching movements when the infants were in the modified chair. In addition, these two achievements were negatively related to reaching experience. These, and other findings, underscore the infrequently investigated supposition that changes in postural control induce improvements in the control of reaching movements during infancy. Recommendations are made about how the procedure adopted in the present study could be used in subsequent research to give further insights into the codevelopment of posture and action. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 168–182, 2002. DOI 10.1002/dev.10021
Assembly of thick, thin, and titin filaments in chick precardiac explants
Authors: Rudy Diane E. , Yatskievych Tatiana A. , Antin Parker B. , Carol C. Gregorio
Published: August 2002

De novo cardiac myofibril assembly has been difficult to study due to the lack of available cell culture models that clearly and accurately reflect heart muscle development in vivo. However, within precardiac chick embryo explants, premyocardial cells differentiate and commence beating in a temporal pattern that corresponds closely with myocyte differentiation in the embryo. Immunofluorescence staining of explants followed by confocal microscopy revealed that distinct stages of cardiac myofibril assembly, ranging from the earliest detection of sarcomeric proteins to the late appearance of mature myofibrils, were consistently recognized in precardiac cultures. Assembly events involved in the early formation of sarcomeres were clearly visualized and accurately reflected observations described by others during chick heart muscle development. Specifically, the early colocalization of α‐actinin and titin dots was observed near the cell periphery representing I‐Z‐I‐like complex formation. Myosin‐containing thick filaments assembled independently of actin‐containing thin filaments and appeared centered within sarcomeres when titin was also linearly aligned at or near cell borders. An N‐terminal epitope of titin was detected earlier than a C‐terminal epitope; however, both epitopes were observed to alternate near the cell periphery concomitant with the earliest formation of myofibrils. Although vascular actin was detected within cells during early assembly stages, cardiac actin predominated as the major actin isoform in mature thin filaments. Well‐aligned thin filaments were also observed in the absence of organized staining for tropomodulin at thin filament pointed ends, suggesting that tropomodulin is not required to define thin filament lengths. Based on these findings, we conclude that the use of the avian precardiac explant system accurately allows for direct investigation of the mechanisms regulating de novo cardiac myofibrillogenesis. © 2001 Wiley‐Liss, Inc.
Direct separation of in vivo and in vitro am3 revertants in transgenic mice carrying the phix174 am3, cs70 vector
Authors: Malling Heinrich V. , Delongchamp Robert R.
Published: August 2002

Target genes in most transgenic systems have higher spontaneous mutation frequencies than do endogenous mammalian genes. Spontaneous mutations in transgenes predominantly arise from three sources: (1) mutations fixed in the animals, (2) mutations arising from replication errors caused by damage to the DNA that may have occurred in vivo or in vitro and then was fixed during amplification of the vector in vitro, and (3) mutations arising during replication of non‐revertant phages in non‐permissive bacteria. An assay based on single bursts was developed to directly distinguish between the in vivo and in vitro origins of revertants. The size of the aliquot is determined by mutant frequency and is adjusted so that ideally no more than 10 to 20% of the aliquots contain a bacterial cell transformed with a mutant phage. Mutations are detected as revertants of an amber mutation (am3) in phiX174 am3, cs70. The minimum burst size of non‐revertant phiX am3, cs70 from splenic DNA on a permissive bacterial strain was larger than 30 plaque‐forming units (pfu). Based on this observation, a burst size of 31 plaque‐forming revertants was chosen as the minimum burst size of a fixed mutation. The single burst assay was tested on DNA from spleens of animals that were treated with 150 mg/kg 1‐ethyl‐1 nitrosurea. Only the fraction of aliquots with single bursts of revertants (> 30) increased in the treated animals compared to the controls. In contrast, there was no difference between treated and control animals for revertant frequencies calculated for burst sizes ≤30 pfu. Among the spontaneous mutations, only 30% were caused by mutations fixed in animals (i.e. burst size >30 pfu). Total average revertant frequency measured in DNA from treated animals was less than twofold more than the average spontaneous frequency (P = 0.048). When frequencies were based on burst sizes >30, there was a 4.6‐fold increase among treated animals compared with controls (P = 0.026). The single burst‐assay resulted in a more sensitive test for mutagenicity because it eliminated noise from in‐vitro mutations. Environ. Mol. Mutagen. 37:345–355, 2001 Published 2001 Wiley‐Liss, Inc.
The significance of rock structure, lithology and pre‐glacial deep weathering for the shape of intermediate‐scale glacial erosional landforms
Authors: Olvmo Mats , Johansson Magnus
Published: August 2002

The main landforms within the glacially scoured Precambrian rocks of the Swedish west coast are closely connected to the principal structural pattern and have lately been explained as mainly a result of etch processes, probably during the Mesozoic and with a possible second period of etching during the Neogene. To explore the effect of multiple glacial erosion on the rock surfaces, an island with two different lithologies and with striae from different directions was selected for a detailed study, focusing on the shape of roches moutonnées. Air‐photo interpretation of bedrock lineaments and roches moutonnées combined with detailed field mapping and striae measurements are used to interpret the structural and lithological control on the resulting shape. The study reveals a significant difference in shape between roches moutonnées in augen‐granite and orthogneiss. Low elongated and streamlined roches moutonnées occur in the gneiss area, striated by a Late Weichselian ice flow from the NE. This ice flow is subparallel with both the local dominant trend of topographically well‐expressed joints and the schistosity of the gneiss. Frequently, there are no signs of quarrying on the lee‐sides of the gneiss roches moutonnées and hence they resemble the shape of whalebacks, or ruwares, as typically associated with the exposed basal weathering surface found in tropical areas. The granite roches moutonnées were formed by an older ice flow from the ESE, which closely followed the etched WNW–ESE joint system of the granite. Late Weichselian ice flow from the NE caused only minor changes of the landforms. On the contrary, marks of the early ESE ice flow are poorly preserved in the gneiss area, where it probably never had any large effect as the flow was perpendicular to both schistosity and structures and, accordingly, also to the pre‐glacial relief. The study demonstrates that coincidence between ice flow direction and pre‐glacially etched structures is most likely to determine the effects of glacial erosion. Copyright © 2002 John Wiley & Sons, Ltd.
Environmental applications of thermal extraction cone penetrometry and ultrafast gas chromatography/mass spectrometry
Authors: Robbat Albert
Published: August 2002

This article describes the collection and analysis of organic contaminants at depth without bringing soil to the surface. A thermal extraction cone penetrometer (TECP) probe was used to extract soil‐bound semivolatile organics, transferring them to the surface for analysis by ultrafast gas chromatography/mass spectrometry (GC/MS). Findings showed that polychlorinated biphenyls, polycyclic aromatic hydrocarbons, chlorinated pesticides, and explosives could be collected and analyzed in 5 min when the soil‐water content was <20% and in 15 min when it was between 20 and 35%. When the TECP was directly connected to the GC/MS, trinitrotoluene (TNT) and four of its synthetic precursors were speciated in 20 sec. Moreover, 51 VOCs were detected by membrane‐inlet mass spectrometry in ∼10 sec. Organics were “sniffed” from a vial and identified using the Ion Fingerprint Detection™ software. The algorithms provide the means to untangle complex mass spectra making real‐time, electronic nose detection and identification by MS possible. © 2001 John Wiley & Sons, Inc. Field Analyt Chem Technol 5: 60–68, 2001
The shallow flow equations solved on adaptive quadtree grids
Authors: Borthwick A. G. L. , Cruz León S. , Józsa J.
Published: August 2002

This paper describes an adaptive quadtree grid‐based solver of the depth‐averaged shallow water equations. The model is designed to approximate flows in complicated large‐scale shallow domains while focusing on important smaller‐scale localized flow features. Quadtree grids are created automatically by recursive subdivision of a rectangle about discretized boundary, bathymetric or flow‐related seeding points. It can be fitted in a fractal‐like sense by local grid refinement to any boundary, however distorted, provided absolute convergence to the boundary is not required and a low level of stepped boundary can be tolerated. Grid information is stored as a tree data structure, with a novel indexing system used to link information on the quadtree to a finite volume discretization of the governing equations. As the flow field develops, the grids may be adapted using a parameter based on vorticity and grid cell size. The numerical model is validated using standard benchmark tests, including seiches, Coriolis‐induced set‐up, jet‐forced flow in a circular reservoir, and wetting and drying. Wind‐induced flow in the Nichupté Lagoon, México, provides an illustrative example of an application to flow in extremely complicated multi‐connected regions. Copyright © 2001 John Wiley & Sons, Ltd.
The composite finite volume method on unstructured meshes for the two‐dimensional shallow water equations
Authors: Jiwen Wang , Ruxun Liu
Published: August 2002

A composite finite volume method (FVM) is developed on unstructured triangular meshes and tested for the two‐dimensional free‐surface flow equations. The methodology is based on the theory of the remainder effect of finite difference schemes and the property that the numerical dissipation and dispersion of the schemes are compensated by each other in a composite scheme. The composite FVM is formed by global composition of several Lax–Wendroff‐type steps followed by a diffusive Lax–Friedrich‐type step, which filters out the oscillations around shocks typical for the Lax–Wendroff scheme. To test the efficiency and reliability of the present method, five typical problems of discontinuous solutions of two‐dimensional shallow water are solved. The numerical results show that the proposed method, which needs no use of a limiter function, is easy to implement, is accurate, robust and is highly stable. Copyright © 2001 John Wiley & Sons, Ltd.
Relationships between Australian real estate and stock market prices—a case of market inefficiency
Authors: Okunev John , Wilson Patrick , Zurbruegg Ralf
Published: August 2002

This paper explores the relationship between the Australian real estate and equity market between 1980 and 1999. The results from this study show three specific outcomes that extend the current literature on real estate finance. First, it is shown that structural shifts in stock and property markets can lead to the emergence of an unstable linear relationship between these markets. That is, full‐sample results support bi‐directional Granger causality between equity and real estate returns, whereas when sub‐samples are chosen that account for structural shifts the results generally show that changes within stock market prices influence real estate market returns, but not vice versa. Second, the results also indicate that non‐linear causality tests show a strong unidirectional relationship running from the stock market to the real estate market. Finally, from this empirical evidence a trading strategy is developed which offers superior performance when compared to adopting a passive strategy for investing in Australian securitized property. These results appear to have important implications for managing property assets in the funds management industry and also for the pricing efficiency within the Australian property market. Copyright © 2002 John Wiley & Sons, Ltd.
Molecular analysis of nonrandom 8q12 deletions in acute lymphoblastic leukemia: Identification of two candidate genes
Authors: Bardet Valérie , Couque Nathalie , Cattolico Laurence , Hetet Gilles , Devaux Isabelle , Duprat Simone , Gressin Laetitia , Vilmer Etienne , Cavé Hélène , Grandchamp Bernard
Published: August 2002

Acute lymphoblastic leukemia is the most common malignancy in childhood. High‐resolution allelotyping performed in our laboratory showed new chromosomal sites of nonrandom deletions. We have focused our work on 8q12 deletions, which we have found in about 4% of patients (eight of 205 informative cases). These deletions were of small size (less than 1 Mb) in all but one patient, and the deleted region common to all patients was delineated between two microsatellite markers (D8S1113 and D8S1763). This region was sequenced entirely from two overlapping bacterial artificial chromosomes. The common deleted region (120 kb) had a low GC content (37%), was composed more than 50% of LINE sequences, and contained only two candidate genes. The centromeric deletion borders were clustered within an interval of 33 kb between two microsatellite markers. This interval contains the first exon of an HMG‐1‐related gene (KIAA0808) and a putative gene, DL8q12, predicted to encode a protein with 231 amino acid residues with no homolog in protein databases. Analysis of the available mRNA from lymphoblastic cells of two patients with 8q12 deletions using common polymorphisms in the 3′ UTR of KIAA0808 showed monoallelic expression of this gene. Identification of a biallelic polymorphism in the first exon of DL8q12 showed that this gene was deleted in two of four informative cases. Sequencing of the exons of both genes from all patients with 8q12 deletions did not show any mutation, which suggests that neither of these genes behaves as a classic tumor suppressor gene. © 2002 Wiley‐Liss, Inc.