bluuebunny/crossref_metadata_2025 huggingface dataset:
Confocal laser scanning microscopy reveals voltage‐gated calcium signals within hippocampal dendritic spines
Authors: Jaffe David B. , Fisher Stephen A. , Brown Thomas H.
Published: January 2005

The induction of long‐term potentiation (LTP) is generally assumed to be triggered by Ca2+ entry into dendritic spines via NMDA receptor‐gated channels. A previous computational model proposed that spines serve several functions in this process. First, they compartmentalize and amplify increases in [Ca2+]i. Second, they augment the nonlinear relationship between synaptic strength and the probability or magnitude of LTP induction. Third, they isolate the metabolic machinery responsible for LTP induction from increases in [Ca2+]i produced by voltage‐gated Ca2+ channels in the dendritic shaft. Here we examine this last prediction of the model using methods that combine confocal microscopy with simultaneous neurophysiological recordings in hippocampal brain slices. Either of two Ca2+‐sensitive dyes were injected into CA1 pyramidal neurons. Direct depolarization of the neurons via the somatic electrode produced clear increases in Ca2+ signals within the dendritic spines, a result that was not predicted by the previous spine model. Our new spine model suggests that some of this signal could theoretically result from Ca2+‐bound dye diffusing from the dendritic shaft into the spine. Dye diffusion alone cannot, however, explain the numerous cases in which the Ca2+ signal in the spine was considerably larger than that in the adjacent dendritic shaft. The latter observations raise the possiblity of voltage‐gated Ca2+ entry directly into the spine or else perhaps via Ca2+‐dependent Ca2+release. The new spine model accommodates these observations as well as several other recent experimental results. 1994 John Wiley & Sons, Inc.
Calcium signaling in dendritic spines of hippocampal neurons
Authors: Connor John A. , Miller Lucas D. Pozzo , Petrozzino Jeffrey , Müller Wolfgang
Published: January 2005

Intracellular Ca2+ dynamics have been measured using imaging techniques in dendrites and spines of CA3 hippocampal neurons in brain slice under both acute and tissue culture conditions. In response to presynatic stimulation, micromolar levels of Ca2+ are rapidly reached in spines of distal dendrites. If stimulus parameters are chosen judiciously so as to minimize postsynaptic firing, then the dendrite shaft increases are far less. Spine Ca2+ increases are largely dependent upon activation of NMDA receptors. At the large mossy fiber synapses, presynaptic stimuli also produce large Ca2+ increases but the differences in shaft‐spine Ca2+ levels are much less; often they are insignificant. Also at these locations, postsynaptic firing, without presynaptic stimulation is sufficient to produce large increase in spine Ca2+ levels. 1994 John Wiley & Sons, Inc.
Apoptosis in adult retinal ganglion cells after axotomy
Authors: Garcia‐Valenzulela E. , Gorczyca W. , Darzynkiewicz Z. , Sharma S. C.
Published: January 2005

Lesions to the mature mammalian central nervous system cause irreversible degeneration, in which neurons have been previously thought to be passive victims. In this study, axon‐lesioned adult rat nerons are shown instead to actively degrade themselves through the process of apoptosis: a programmed type of cell death in which the cellular apparatus is actively involved in the degradation process. To investigate whether retinal ganglion cells of an adult mammal follow an apoptotic type of death when their axons are severed, DNA breaks in nuclei were labeled in situ, using a method that specifically incorporates biotinylated deoxynucleotides by exogenous terminal deoxynucleotidyl transferase on the 3′‐OH ends of DNA. The active nature of the death mechanism was demonstrated by the reduction in biotin‐labeled nuclei after administering the protein synthesis inhibitor cycloheximide. Our results suggest that retinal ganglion cells of the adult rat die through apoptosis when axotomized. This raises new possibilities in the treatment of CNS injuries, by the potential interruptibility of a program for neuronal death. 1994 John Wiley & Sons, Inc.
Secreted forms of β‐amyloid precursor protein modulate dendrite outgrowth and calcium responses to glutamate in cultured embryonic hippocampal neurons
Authors: Mattson Mark P.
Published: January 2005

In addition to being the major excitatory neurotransmitter in the mammalian brain, glutamate is believed to play a key role in the regulation of neurite outgrowth and snaptogenesis during development. In cultured embryonic hippocampal pyramidal neurons, glutamate inhibits dendrite outgrowth by a mechanism involving elevation of intracellular‐free calcium levels ([Ca2+]i). In the present study, secreted forms of the β‐amyloid precursor protein (APPss) counteracted the inhibitory effect of glutamate on dendrite outgrowth in cultured embryonic hippocampal neurons. The prolonged elevation of [Ca2+]i normally induced by glutamate was significantly attenuated in neurons that had been pretreated with 2–10 nM of APPs695 or APPs751. Immunocytochemistry with β‐amyloid precursor protein antibodies showed that immunoreactivity was concentrated in axons and, particularly, in their growth cones. Because β‐amyloid precursor proteins are axonally transported, and APPss can be released from axon terminals/growth cones in response to electrical activity, the present findings suggest that APPss may play a role in developmental and synaptic plasticity by modulating dentritic responses to glutamate. 1994 John Wiley & Sons, Inc.
Differential effects of dihydrotestosterone and estrogen on the development of motoneuron morphology in a sexually dimorphic rat spinal nucleus
Authors: Goldstein L. A. , Sengelaub D. R.
Published: January 2005

The rat lumbar spinal cord contains a sexually dimorphic motor nucleus, the spinal nucleus of the bulbocavernosus (SNB), whose motoneurons innnervate perineal muscles involved in copulatory reflexes. Dendritic development of SNB motoneurons is biphasic and androgen dependent. During the first 4 postnatal weeks, SNB dendrites grow exuberantly, and subsequently retract to mature lengths by 7 weeks of age. After early postnatal castration, SNB dendrites fail to grow, and testosterone replacement restores this growth. In other systems, testosterone and its metabolites, dihydrotestosterone and estrogen, are important for somatic and neural sexual differentiation. The purpose of the present study was to examine the effects of castration and dihydrotestosterone or estrogen replacement on the growth of SNB motoneuron somata and dendritic arbors.

Male rat pups were castrated on postnatal (P) day 7 and treated daily with either dihydrotestosterone propionate (DHTP; 2 mg) or estradiol benzoate (EB; 100 μg) until P28 or P49. By using cholera toxin horseradish peroxidase (BHRP) histochemistry, the soma size, dendritic length, dendritic extent, and arbor area of BHRP‐labeled SNB motoneurons were measured and analyzed. Both DHTP and EB treatment supported the initial exuberant growth of SNB dendrites through P28, but EB treatment was ineffective in maintaining mature, adult lengths at P49. The possible sites of hormone action and functional implications of these hormonal treatments are discussed. 1994 John Wiley & Sons, Inc.
Expression of winged helix genes, BF‐1 and BF‐2, define adjacent domains within the developing forebrain and retina
Authors: Hatini Victor , Tao Wufan , Lai Eseng
Published: January 2005

One of the earliest events in the development of the central nervous system is the establishment of positional identity along the anteroposterior (AP) axis of the neuroepithelium. In recent years, regulatory genes with regionally restricted expression in the neuroepithelium have been idenfitied which are believed to specify its developmental fate. We have previously described Brain Factor‐1 (BF‐1), a winged helix (WH) transcription factor expressed in the telencephalic neuroephithelium (Tao and Lai, 1992) Neuron 8:957–966. Here we report the cloning of the mouse cDNA for a novel WH protein, BF‐2. We show that BF‐2 is a sequence‐specific DNA binding protein with a binding specificity distinct from BF‐1. Its expression in the CNS during embryogenesis is restricted to the rostral diencephalic neuroepithelium. The caudal boundary of BF‐2 expression is at the zona limitans intrathalamica. Rostrally, the BF‐2 expression domain is adjacent to that of BF‐1. The expression domains of these two factors define a boundary within the developing forebrain neuoepithelium. The BF‐1/BF‐2 boundary also extends laterally to divide the optic stalk and the retina into nasal (anterior) and temporal (posterior) domains. These observations suggest that in adition to playing a role in the subdivision of the forebrain, these two WH factors may also function to establish positional information in the retinal neuroepithelium. 1994 John Wiley & Sons, Inc.
Pharmacological characterization of a serotonin receptor involved in an early embryonic behavior of Helisoma trivolvis
Authors: Goldberg Jeffrey L. , Koehncke Niels K. , Christopher Kim J. , Neumann C. , Diefenbach Thomas J.
Published: January 2005

In contrast to the abundance of information on the many physiological and developmental actions of serotonin in molluscan nervous systems, comparatively little is known about the serotonin receptors involved in these responses. Embryos of the pulmonate gastropod, Helisoma trivolvis, display a cilia‐driven rotational behavior that is regulated by endogenous serotonin. In the present study, two functional assays were used to determine some of the pharmacological properties of the receptors that mediate the cilio‐excitatory action of serotonin. Timelaspe video microscopy was used to measure whole embryo rotation rat and cilia beat frequency in isolated cells. In dose‐response experiments, serotonin was approximately 10 times more potent in stimulating cilia beat frequency over embryo rotation. In rotation experiments, 5‐carboxyamidotryptamine and methysergide had effective agonist activity in dose ranges similar to that of serotonin (1 to 100 μM). In contrast, 8‐hydroxydiproylaminotetralin HBr (8‐OH‐DPAT) displayed agonist activity of lower potency and effectiveness. Several compounds displayed antagonist activity in the 1 to 100 μM dose range, including mianserin, spiperone, ritanserin, 1‐(1‐naphthyl) piperazine, and Propranolol. α‐Methylserotonin had mixed agonist–antagonist activity, and metoclopramide, MDL‐72222, and ketanserin were inactive. Experiments on isolated cells suggested that the extremely effective antagonism displayed by mianserin in the embryo rotation assay was due to its specific activity at ciliary serotonin receptors. These results implicate the presence of a novel serotonin receptor on embryonic ciliated cells that is pharmacologically distinct from those previously characterized in vertebrate or invertebrate systems. 1994 John Wiley & Sons, Inc.
Gap‐43 immunoreactivity and axon regeneration in retinal ganglion cells of the rat
Authors: Schaden H. , Stuermer C. A. O. , Bähr M.
Published: January 2005

Retinal ganglion cells (RGCs) in rats were retrogradely labeled with the fluorescent tracer Fluorogold (FG) and subjected to GAP‐43 and c‐JUN immunocytochemistry to identify those RGSs that are capable of regenerating an axon. After optic nerve section (ONS) and simultaneous application of FG to the nerve stump (group 1 experiments), GAP‐43 immunoreactive RGCs (between 2 and 21 days after ONS) always represented a subfraction of both FG‐labeled (i.e., surviving) RGCs and RGCs exhibiting c‐JUN. GAP‐43 immunoreactive RGCs represented 22% of RGCs normally present in rat retinae and 25% of surviving RGCs at 5 days after ONS but were reduced to 2% and 1%, which is 6% and 5% of survivors at 14 and 21 days, respectively. In animals that received a peripheral nerve (PN) graft after ONS (group 2 experiments), RGCs with regenerating axons were identified by FG application to the graft at 14 and 21 days. When examined at 21 and 28 days, all FG‐labeled RGCs exhibited GAP‐43 immunoreactivity, and FG/GAP‐43‐labeled RGCs were 3% and 2% of those resent in normal rat retinae. In relation to surviving. RGCs GAP‐43 immunoreactive RGCs represented 10% at both time points. FG‐/GAP‐43 labeled RGCs also exhibited c‐JUN, but c‐JUN immunoreactive RGCs were at both time points at least twice as numerous a FG‐/GAP‐43‐labeled RGCs. These data suggest that regenerating axons in PN grafts derive specifically from GAP‐43 reexpressing RGCs. Appearance of GAP‐43 immunoreactivity may therefore identify those RGCs that are capable of axonal regeneration or sprouting. 1994 John Wiley & Sons, Inc.
Spontaneous bursting and long‐lived local correlation in normal and denervated tectum of goldfish
Authors: Lyckman Alvin W. , Meyer Ronald L.
Published: January 2005

The formation of fine retinotopic order by growing optic fibers in the goldfish is thought to be mediated by the correlated firing of optic fibers from neighboring retinal ganglion cells. Although the activity of the tectal cells must also be important for this activity‐dependent refinement, few studies have analyzed the pattern and local correlation of the intrinsic activity of tectal neurons and the effect of denervation on this activity. To address this issue, spontaneous (nonoptic driven) activity was analyzed and cross‐correlograms were computed between individual tectal neurons using single and double electrode extracellular recordings. Recordings were made in normally innervated tectum in which the contribution of optic activity was eliminated by short‐term intraocular blockade with tetrodotoxin and in denervated tecta in which the optic nerve had been severed several weeks prior. Several observations were relevant to activitydependent refinement: First, coupling between neighboring tectal cells is weak. Second, the time duration for local correlation is relatively long, as long as 200 ms. Third, tectal neurons exhibit spontaneous bursting. Fourth, denervation increased the level of spontaneous activity in the tectum. The increased spontaneous activity and bursting following denervation implies that tectal neurons are more excitable when optic fibers are beginning to reinnervate the tectum. This could make it possible for optic fibers to drive tectal neurons at a time when their input to individual neurons is severely weakened by a lack of spatial convergence. The weak coupling between tectal cells and the consequent long‐time constant for correlated activity implies a constraint on the duration of correlated retinal activity that is used for activitydependent refinement. Since optic fibers likely need to detect the postsynaptic activity of a local group of tectal neurons, rather than that of a single neuron, the long tectal time constant means that retinal activity need not be correlated with precision much better than 200 ms because the postsynaptic circuitry cannot generate shorter correlations. © 1995 John Wiley & Sons, Inc.
Lectin binding distinguishes between neuroendocrine and neuronal derivatives of the sympathoadrenal neural crest
Authors: Katz David M. , White Melissa E. , Hall Alison K.
Published: January 2005

Lectin cytochemistry was used to identify surface epitopes selectively expressed by chromaffin cell chemoreceptors (glomus cells) in the rat carotid body. Unexpectedly, these studies revealed that binding sites for peanut agglutinin (PNA; Arachis hypogea) were highly expressed by all neuroendocrine derivatives of the sympathoadrenal neural crest, including glomus cells, small, intensely fluorescent cells, and adrenal chromaffin cells in situ. In contrast, principal sympathetic neurons did not express PNA receptors. PNA binding was inhibited by 2% galactose. To determine whether expression of PNA receptors was selectively induced by neuroendocrine differentiation of sympathoadrenal precursors, we compared PNA labeling of embryonic sympathoblasts in the presence of either nerve growth factor (NGF) or the synthetic glucocorticoid dexamethasone (DEX). Dex‐treated cells, which expressed several neuroendocrine traits, bound PNA, whereas NGF‐treated neuronal derivatives did not. In addition, to examine whether expression of existing PNA receptors was down‐regulated by neuronal differentiation of chromaffin cells, we compared labeling of PC12 cells, which normally bind PNA, in the presence and absence of NGF. Although PC12 cells acquired characteristic neuronal morphologies in the presence of NGF, they did not lose PNA labeling, even after 8 days of NGF treatment. These findings indicate that neuronal and neuroendocrine derivatives of the sympathoadrenal lineage can be distinguished by differential expression of carbohydrate epitopes and suggest that PNA receptors are induced by neuroendocrine differentiation. © 1995 John Wiley & Sons, Inc.
Red‐light‐induced suppression of melatonin synthesis is mediated by N‐methyl‐D‐aspartate receptor activation in retinally normal and retinally degenerate rats
Authors: Poeggeler Burkhard H. , Barlow‐Walden Lornell R. , Reiter Russel J. , Saarela Seppo , Menendez‐Pelaez Armando , Yaga Ken , Manchester Lucien C. , Chen Li‐Dun
Published: January 2005

Pineal gland N‐acetyltransferase (NAT) activity and pineal and serum levels of melatonin declined linearly in albino rats acutely exposed to different intensities of red light (600 nm or higher; low, 140μ W/cm2; moderate, 690 μW/Cm2; high, 1200 μW/Cm2) during the middle of the night. The high intensity red light was as effective as white light (780 μW/cm2) in suppressing NAT activity and pineal and circulating melatonin. Red‐light‐inhibited nighttime NAT activity and suppressed nocturnal melatonin levels in both retinally degenerate and normal rats. Pretreatment with the N‐methyl‐D‐aspartate (NMDA) receptor antagonist MK‐801 (10 mg/kg intraperitoneally) completely prevented the red‐light‐induced inhibition of nighttime melatonin synthesis. Magnesium chloride (300 mg/kg intraperitoneally) reduced the inhibitory effects of low and moderate intensities of red light but was ineffective when high red‐light intensity was used. However, both agents failed to antagonize the suppression of nighttime melatonin synthesis elicted by the exposure to white light. Since retinally degenerate and retinally normal animals respond in the same way to both red‐light and pharmacological intervention with the NMDA receptor blocker MK‐801, the findings indicate that the activation of central hypothalamic NMDA receptors might mediate the photic inhibition of nocturnal melatonin synthesis in the pineal gland elicited by the exposure to red light at night. Red‐light‐induced suppression of nocturnal melatonin synthesis possibly can be used to investigate the biochemical mechanisms by which light entrains melatonin synthesis and to study the pharmacological and physiological effects of endogenous and synthetic agents that antagonize the NMDA receptor response. © 1995 John Wiley & Sons, Inc.
Transforming growth factor‐β‐3 is mitogenic for rat retinal progenitor cells in vitro
Authors: Anchan Raymond M. , Reh Thomas A.
Published: January 2005

Recent data indicate that the process of neurogenesis in the mammalian central nervous system (CNS) may be regulated by peptide growth factors, such as epidermal growth factor, transforming growth factor‐alpha, and acidic or basic fibroblast growth factor. We have investigated whether members of the transforming growth factor‐beta (TGFβ) family also play a role in this process and have found that TGFβ‐3 is mitogenic for embryonic rat retinal cells in vitro. We also show that TGFβ‐3 stimulates production of retinal amacrine cells while photoreceptor production remains unchanged. These data demonstrate that TGFβ‐3 can regulate cell proliferation in the CNS during development and can also influence commitment or differentiation, or both, of neural progenitor cells to particular retinal fates. © 1995 John Wiley & Sons, Inc.
White‐throated sparrow morphs that differ in song production rate also differ in the anatomy of some song‐related brain areas
Authors: DeVoogd Timothy J. , Houtman Anne M. , Falls J. Bruce
Published: January 2005

White‐throated sparrows are unusual among songbirds in that they occur in two color morphs, white‐striped and tan‐striped, determined by a chromosomal inversion and maintained by negative assortative mating. These differ in several reproductive behaviors, including amount of singing: white‐striped males sing frequently, tan‐striped females never sing, and tan‐striped males and white‐striped females sing an intermediate amount. The present study measures the volumes of several nuclei in the avian song system and relates these to color morph and to sex. We find that robustus archistristalis and the tracheosyringeal part of the hypoglossal nucleus, nuclei closely involved in song production, are larger in white‐striped than in tan‐striped birds. We also find morph differences for nuclei in the rostal division of the song system, nuclei believed to be less directly involved in song production. We find sex differences throughout the song system as has been reported in other songbirds. Relationships between structure and function in the song system are discussed. © 1995 John Wiley & Sons, Inc.
Role of neuropeptide Y (NPY) in cardiovascular responses to stress
Authors: Zukowska‐Grojec Z. , Vaz A. C.
Published: January 2005

Neuropeptide Y (NPY), a putative sympathetic neurotransmitter and neuromodulator, is released during sympathetic nerve stimulation and causes vasoconstriction and cardiodepression. Whether the release of NPY contributes to stress‐induced cardiovascular responses was assessed by studying i/ plasma levels of circulating NPY‐immunoreactivity (NPY‐ir) during various stress paradigms and ii/ mechanisms of action of NPY in the cardiovascular system of the rat. Plasma NPY‐ir was increased by all stress situations, such as transfer to a new environment (by 52%), exposure to cold water (40C) (by 117%) and hemorrhage (4 ml/300 g body weight) (by 231%). The cold water, stressinduced, maximal increase in circulating plasma NPY‐ir was delayed in relation to the peak pressor response by 10–20 min. Administration of NPY caused dose‐dependent pressor responses that were greater in pithed rats ‐ which have all centrally mediated circulatory reflexes removed ‐ than in conscious rats. Infusion of a low pressor (8.5 ± 1.5 mm Hg) dose of norepinephrine into conscious rats potentiated NPY‐mediated pressor responses 2‐fold and also tended to increase bradycardic effect of a higher dose of NPY (by 19%). Thus hypertensive and bradycardic actions of NPY appear to depend on the level of adrenergic activity and on the interactions at the level of vascular smooth muscle, heart, and baroreceptor reflexes. During a hyperadrenergic state such as stress, cardiovascular effects of NPY may be greatly accentuated. NPY may enhance and prolong the stressinduced hypertensive responses while antagonizing adrenergic cardiostimulation.
Ultrastructural characterization and GAD Co‐localization of somatostatin‐like immunoreactive neurons in CA1 of rabbit hippocampus
Authors: Kunkel Dennis D. , Schwartzkroin Philip A.
Published: January 2005

Immunocytochemical techniques have been used to identify a striking interneuronal population which is immunoreactive for the peptide, somatostatin. The cell population, which is seen most densely in stratum oriens and at the oriens/alveus border of the CA1 region of rabbit hippocampus, was characterized in light and electron microscopic observations. The cells have dendrites which extend parallel to and into the alveus, with occasional processes ascending through stratum pyramidale toward the hippocampal fissure. The dendrites receive numerous synaptic contacts directly onto aspinous dendritic shafts. Axon collaterals ramify profusely within the pyramidale region, and among the proximal apical and basal pyramidal cell dendrites in areas of stratum radiatum and stratum oriens. Somatostatin‐like immunoreactive terminals make synaptic contact, primarily of the symmetric type, with the somata and proximal dendrites of pyramidal neurons. Somatostatin‐like neurons are found at approximately equal density in the hippocampus of immature (8 days postnatal) and mature (30 days postnatal) rabbit. Double‐labelling techniques, to identify both somatostatin‐like and glutamic acid decarboxylase (GAD) immunoreactive neurons, demonstrated that a large proportion of the somatostatin neurons were also GABAergic.
Polyamines regulate glycine interaction with the N‐methyl‐D‐aspartate receptor
Authors: Ransom Richard W. , Deschenes Nancy L.
Published: January 2005

[3H]Glycine blinding studies have been performed to further characterize polyamine interactions with the rat brain N‐methyl‐D‐asparate (NMDA) receptor. Strychnine‐insensitive [3H]glycine binding to washed cortical membranes was enhanced by spermine, spermidine, and hirudonin. Spermine stimulation of binding was additive with that produced by the NMDA receptor agonist L‐glutamate. A high concentration of the L‐glutamate antagonist 2‐amino‐5‐phosphonovaleric acid reduced, but did not eliminate, spermine effects. Saturation experiments indicated that L‐glutamate and spermine enhancement of binding was due to an increase in [3H]glycine binding affinity. Kinetic studies showed that optimal concentrations of spermine and L‐glutamate reduced [3H]glycine association and dissociation rates by approximately fivefold and 30‐fold, respectively. In competition experiments, the presence of L‐glutamate and spermine had differential effects on the affinites of compounds that act as either agonists or antagonists at the glycine site of the NMDA receptor. The affinities of the agonists glycine, D‐serine, and Dalanine, were increased about fivefold, while antagonist (HA‐966, 7‐chlorokynurenic acid) inhibitory potencies were unchanged. These data support our previous results showing that the NMDA receptor possesses a novel polyamine recognition site and demonstrate that these compounds directly modulate glycine's interactions with the receptor complex.
Dopamine neuron ontogeny: Electrophysiological Studies
Authors: Pitts David K. , Freeman Arthur S. , Chiodo Louis A.
Published: January 2005

The ontogeny of nigrostriatal dopamine (NSDA) neurons was examined with single‐unit extracellular electrophsiological methods. The physiological and pharmacological characteristic of 2‐, 4‐, and 5‐week‐old rat pup NSDA neurons were compared with those of adults (8–10 weeks old). Although the basal discharge rate, conduction velocity, and firing pattern of NSDA neurons from 4‐and 5‐week‐old rats were similar to adults, the 2‐week‐old‐rats differed significantly in all three of these physiological significanlty lower in the 2‐week‐old pups relative to adult. In addition, there were significantly fewer bursting NSDA neurons in 2‐week‐olds than there were in adults. Two and 4‐week‐olds exhibited significantly lower sensitivity to cumulative intravenous doses of apomorphine. In contrast, the sensitivity to cumulative intravenous doses of quinpirole was found to be similar across all age groups. It is evident that the pharmacological and physiological properites of NSDA neurons are in a dynamic state of flux during postnatal development. These electrophysiological findings are discussed in the context of the perinatal development of midbrain DA systems.
Die Absorption von Stickstoff durch Calcium und seine Legierungen
Authors: Ruff Otto , Hartmann Hellmuth
Published: January 2005

Calcium und calciumreiche Legierungen lassen sich in einem gegen die Luft abgeschlossenen Eisentiegel schmelzen. Den Abschluß erreicht man in befriedigender Weise, wenn man die Tiegelöffnung entweder autogen verschweißt oder durch eine Calcium‐chloridfluoridschmelze schließt, in welche der Tiegel mit der Öffnung nach unten eingesetzt wird.
Über die thermische Bildung von Ozon
Authors: Riesenfeld E. H. , Beja M.
Published: January 2005

Die Bestimmung desthermischen Ozon‐Sauerstoff‐Gleichgewichts erfolgt am besten durch Untersuchung des bei der Explosion von Ozon‐Sauerstoffgemischen zurückbleibenden Gases. Dieses besteht bei der Explosion eines Gemisches, welches weniger als 37 Vol. ‐% Ozon enthält, aus reinem Sauerstoff. Die hierbei theoretisch erreichbare Maximaltemperatur beträgt 2130° abs. Die mit Sauerstoff im Gleichgewicht stehenden Ozonmengen liegen also bis zu dieser Temperatur unterhalb der analytischen Nachweisbarkeit, sie betragen weniger als 2 · 10−5 Vol.‐%. Bei der Explosion von 45 Vol. %, igem bis 94 Vol. %igem Ozon bleiben nach der Explosion unabhängig von der Anfangskonzentration des Ozons zwischen 2.10−6 und 1·10−6 Vol.‐% Ozon zurück. Bei diesen Explosionen können Maximaltemperaturen von 2385–3175° erreicht werden. Nach dem NERNST'schen Theorem ist 4,2 · 10−5 Vol.‐% die maximale Ozonkonzentration, dio sich thermisch ausgehend von reinem Ozon (0° und 760 mm), durch Explosion bei konstantem Volumen, bilden kann. Hierbei wird eine Temperatur von 3200° abs., also ein Druck von 17,6 Atm. erreicht.
Über die Absorptionsspektra von gefärbten Gläsern
Authors: Fedotieff P. P. , Lebedeff A.
Published: January 2005

Die Versuche mit der Färbung der Gläser und die Untersuchung der Absorptionsspektra derselben führten zur Konstruktion der Absorptionskurven sowohl im sichtbaren wie auch zum Teil im ultravioletten Gebiete des Spektrums. Für das letzte dienten die photographischen Aufnahmen der Spektra. Die am besten gelungenen Photographien sind in den Figuren 8–27 wiedergegeben. In der beistehenden, auf diese Aufnahmen bezogene Tabelle sind angegeben: die Zusammensetzung des Glases, die färbende Substanz, der Abstand von der Lichtquelle in cm, die Dauer der Exposition und endlich die Dicke der Platten in mm.
Über Cupro‐cupri‐cyanid‐ammoniak‐Verbindungen
Authors: Benbath A. , Schröder W.
Published: January 2005

Die Cupro‐cupricyanid‐ammoniakverbindungen wurden als zu zwei Reihen, nämlich der

und der

gehörig erkannt. Die Bedingungen, unter denen die Glieder der Reihen ineinander übergehen, wurden festgelegt.
Die Anwendung von flüssigem Amalgam in der volumetrischen Analyse. V. Bestimmung von Phosphorsäure durch Uranylacetat
Authors: Someya Kin'ichi
Published: January 2005

Es wurde eine neue Methode für die Bestimmung von Phosphorsäure ausgearbeitet, indem das kristallinisch gefällte Uranylammoniumphosphat mit Salzsäure aufgenommen, mit Zink‐ oder Wismutamalgam reduziert und mit Kaliumbichromat titriert wird unter Anwendung von Diphenylamin als Indicator.
Über die bei chemischen Reaktionen auftretenden Nebel. IV. Absorption chemischer Nebel durch Flüssigkeiten und durch feste Stoffe
Authors: Remy Heinrich , Finnern Hans
Published: January 2005

Die Absorption von trockenen und von feuchten chemischen Nebeln durch Stoffe verschiedener Art wurde vergleichend untersucht.
Serial follow‐up study of serum testosterone and antisperm antibodies in patients with non‐obstructive azoospermia after conventional or microdissection testicular sperm extraction
Authors: Komori K. , Tsujimura A. , Miura H. , Shin M. , Takada T. , Honda M. , Matsumiya K. , Fujioka H.
Published: December 2004

Testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection is becoming a first‐line treatment even for non‐obstructive azoospermia. The current focus of TESE is the identification of seminiferous tubules that contain spermatozoa and minimization of testicular damage. Although microdissection TESE has been introduced as a preferred procedure for sperm retrieval, no serial follow‐up studies of testicular damage have been reported. In the present study, we assayed serum testosterone concentrations and for the presence of antisperm antibodies (ASA) for 1 year after conventional multiple TESE or microdissection TESE and compared postoperative testicular damage between procedures. Thirteen patients who underwent conventional multiple TESE and 12 patients who underwent microdissection TESE were included in this study. Serum total and free testosterone concentrations were evaluated before operation and 1, 6 and 12 months after TESE. Serum ASA was also evaluated before and 12 months after TESE. Serum total and free testosterone concentrations in all patients in both groups showed no significant postoperative decrease. A comparison between the two groups of serum total and free testosterone concentrations showed no significant difference (total testosterone, p = 0.2477; free testosterone, p = 0.3098). No incidence of new ASA formation was identified in the present study. In conclusion, TESE procedures cause neither a decrease of serum testosterone nor formation of ASA. Serum testosterone concentration are similar between patients in the conventional multiple TESE and microdissection groups. Therefore, microdissection TESE is safe with respect to testicular damage, particularly for patients with hypogonadism.
Clinical analysis of patients with azoospermia factor deletions by microdissection testicular sperm extraction
Authors: Tsujimura Akira , Matsumiya Kiyomi , Takao Tetsuya , Miyagawa Yasushi , Koga Minoru , Takeyama Masami , Fujioka Hideki , Okuyama Akihiko
Published: December 2004

Microdeletions of the azoospermia factor (AZF) locus on the Y chromosome have been implicated as a major genetic component of idiopathic male infertility, and the incidence of AZF deletions has been reported to be 15–20% in men with non‐obstructive azoospermia (NOA). Numerous studies have described AZF deletion rates in patients with azoospermia; however, a clinical comparison of azoospermic patients with AZF deletion and those with no deletion has not been reported well. A new technique for testicular sperm extraction, microdissection testicular sperm extraction (TESE), has been used widely on NOA patients. Although testicular spermatozoa are reliably detected and retrieved from NOA patients by microdissection TESE, sperm retrieval rates for patients with AZF deletions are not well known. Therefore, characteristics of NOA patients with AZF deletion were investigated. Six of 60 patients (10%) who underwent microdissection TESE were found to have AZF deletions by genomic polymerase chain reaction. Testicular data, outcome of sperm retrieval and endocrinological profiles, were compared between patients with AZF deletions (n = 6) and those with no deletions (n = 54). Testicular size, varicocele rates and testicular histology were similar between the groups. Significant differences were not detected in the endocrinological profiles. Sperm retrieval rates were not significantly different between the groups. In conclusion, AZF deletions do not appear to confer specific characteristics to NOA patients.
Effect of neonatal exposure to diethylstilbestrol on testicular gene expression in adult mouse: comprehensive analysis with cDNA subtraction method
Authors: Matsuno Yoshiharu , Adachi Tetsuya , Koh Kyu‐Bom , Fukata Hideki , Sugimura Atsushi , Sakurai Kenichi , Shibayama Takako , Iguchi Taisen , Komiyama Masatoshi , Mori Chisato
Published: December 2004

In utero or neonatal exposure to high levels of exogenous steroid hormones, such as the potent synthetic diethylstilbestrol (DES), incurs an increased risk of malfunctional male reproduction. In this study, we investigated whether neonatal exposure to DES induces the alteration of mRNA expression in adult mouse testis. Using a cDNA subtraction method, we isolated seven gene clones whose expression was changed in neonatally DES‐treated mouse testis. Northern blot analysis revealed that five up‐regulated genes (AF326230, AF356521, AK004975, AK006136 and BM237156) and two down‐regulated genes (AK017044, AK017130) were predominantly expressed in testes of 8‐week‐old mice. Moreover, we confirmed that the expression of these seven genes was altered by neonatal DES‐exposure using Northern blot analysis. Our results suggest that neonatal exposure to DES leads to the alteration of gene expression in the testis in the long term. These genes might be useful as biological markers of foetal or neonatal exposure to exogenous steroid hormones, such as DES.
Cellularity of human annulus tissue: an investigation into the cellularity of tissue of different pathologies
Authors: Ford J L , Jones P , Downes S
Published: December 2004

Aims:  To investigate the cells of the inner annulus and to demonstrate that differences in disc pathology can be identified at the cellular level.

Methods and results:  Annulus tissue taken from scoliotic, degenerate and prolapsed human disc tissue was processed for histology and transmission electron microscopy. Ki67 antibody was used to identify cells in the active part of the cell cycle and cell surface receptors for the matrix‐degrading enzyme urokinase were immunolocalized. More chondron clusters were observed in tissue from prolapsed discs than in degenerate and scoliotic discs. Positive Ki67 staining was detected in cells within chondron clusters. Most cells observed from scoliotic and prolapsed annulus contained distinctive nuclei and organelles, whereas cells from degenerate discs contained very few well‐defined organelles but abundant glycogen deposits. Immunolocalization identified urokinase receptors on the surface of cells from degenerate discs but not in the other pathologies.

Conclusions:  Cellular differences appear to underlie different types of disc pathology. The annulus tissue taken from prolapsed discs appeared to contain more chondron clusters and more active cells than scoliotic and degenerative tissue, suggesting a possible wound repair response. In contrast, cell and matrix degeneration appeared to be the most significant underlying processes in degenerate discs.
Leiomyoblastoma of the uterus: an immunohistochemical and electron microscopic study of distinctive tumours with immature smooth muscle cell differentiation mimicking fetal uterine myocytes
Authors: Watanabe K , Ogura G , Suzuki T
Published: December 2004

Aims:  We present three distinctive uterine tumours which exhibited immature smooth muscle differentiation mimicking smooth muscle cells of the fetal uterus.

Methods and results:  The patients were 45, 46 and 49 years old, and all of them had simple hysterectomies. Grossly, all tumours were present in the uterine body, and two of the three tumours were well demarcated 60‐mm and 85‐mm lesions, and the other tumour was a small 25‐mm incidental lesion within multiple conventional leiomyomas. The tumours had varied histological features and were composed of round epithelioid, rhabdoid and large vacuolated cells intermingled with spindle‐shaped cells to various degrees. Although their round vesicular nuclei showed mild to moderate variation in size, prominent nuclear atypia was not seen. Necrosis and mitotic figures suggesting biological aggressiveness were not present in any of the tumours. Immunohistochemically, tumour cells were intensely positive for desmin and α‐smooth muscle actin, whereas positivity for heavy molecular weight caldesmon was restricted. In addition, two cases were positive for non‐muscle myosin heavy chain (SMemb). Ultrastructurally, most tumour cells contained various amounts of intermediate filaments which were occasionally abundant and aggregated as in rhabdoid cells. Well‐developed myofilaments with focal densities were observed in only a few tumour cells. Intermediate filaments and bundles of thin filaments without dense bodies were often intermingled and they occasionally formed distinctive complexes with many irregular dense body‐like structures and crystalloid bodies. Other cytoplasmic organelles including rather rich mitochondria, some rough endoplasmic reticulum and free ribosomes were also common.

Conclusions:  These findings support their immature smooth muscle cell differentiation which mimics the mesenchymal cells of fetal uterus during 14–26 weeks of gestation. The term ‘uterine leiomyoblastoma’ is thought to be appropriate for describing these distinctive immature smooth muscle tumours.
Oestrogen receptor negativity as a marker for high‐grade ductal carcinoma in situ of the breast
Authors: Baqai T , Shousha S
Published: December 2004

Aims:  To compare the morphological and immunohistochemical characteristics of oestrogen receptor (ER)‐negative and ER‐positive ductal carcinoma in situ (DCIS) of the breast, in an attempt to establish more objective criteria for the classification of DCIS.

Methods and results:  Sections of 64 cases of in‐situ carcinoma of the breast were stained for ER, progesterone receptors (PgR), androgen receptors (AR), c‐erbB‐2 and p53, using the immunoperoxidase technique. The cases included 60 DCIS and four lobular carcinoma in situ (LCIS). Four DCIS lesions were associated with foci of microinvasion. The 60 DCIS cases included 31 high grade, 23 intermediate grade and six low grade. Twenty‐four DCIS cases (40%) were ER‐negative and 36 were positive. ER negativity was significantly associated with high nuclear grade (88% versus 27% for ER‐positive cases, P < 0.001), PgR negativity (100% versus 25%, P < 0.001), c‐erbB‐2 positivity (79% versus 14%, P < 0.001) and p53 positivity (58% versus 6%, P < 0.001). There was no difference between ER‐negative and ‐positive DCIS as regards AR expression, with 91% of cases in each group being AR‐positive. Of the four cases of DCIS with microinvasion, three were ER‐ and PgR‐negative, all four were c‐erbB‐2‐positive and AR‐positive and one was p53‐positive. None of the four LCIS was ER, PgR or AR‐negative and none was c‐erbB‐2‐ or p53‐positive.

Conclusions:  There is a highly significant direct relationship between ER negativity in DCIS and high nuclear grade, PgR negativity and c‐erbB‐2 and p53 positivity. We suggest that immunohistological assessment of ER status may help in providing a more objective way of classifying DCIS.
Clinicopathological associations of CD44 mRNA and protein expression in primary breast carcinomas
Authors: Berner H S , Suo Z , Risberg B , Villman K , Karlsson M G , Nesland J M
Published: December 2004

Aims:  The purpose of this study was to examine the occurrence of CD44 isoforms in breast carcinomas and their role in predicting clinical outcome.

Methods and results:  Shock‐frozen tumour tissues from 110 patients with breast carcinoma were examined by immunohistochemistry using antibodies directed against CD44s, v5, v6, v7 and v3–10. In addition, 80 of these tumours were available for quantitative real‐time reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis of CD44s and CD44v6. Immunohistochemically, the positive tumours showed cytoplasmic and/or membranous staining with all antibodies. Staining results did not correlate with histological subtype, lymph node status, status of steroid receptors, tumour size or age. Neither was any correlation found for overall and disease‐free survival. Quantitative real‐time RT‐PCR of CD44s and CD44v6, however, revealed that expression of CD44v6 mRNA was significantly associated with lower pathological grade (Pearson χ2 test P = 0.009; linear‐by‐linear association P = 0.003). Linear‐by‐linear association between CD44s mRNA expression and lower pathological grade was also seen (P = 0.02). Survival analysis with the Kaplan–Meier method demonstrated that increased CD44s mRNA expression was significantly associated with both disease‐free survival and overall survival (P = 0.0185 and P = 0.0344, respectively). A similar trend for CD44v6 mRNA expression was seen in these cases, but the difference was not significant.

Conclusions:  Quantitative real‐time RT‐PCR revealed clinical correlations of CD44s and CD44v6 mRNA expression in breast carcinomas while immunohistochemistry for the protein expression of CD44s and other CD44 variants did not. This contradictory result merits further studies concerning the clinical impact of CD44 molecules in breast carcinomas.
Plasmablastic lymphoma in HIV+ patients: an expanding spectrum
Authors: Chetty R , Hlatswayo N , Muc R , Sabaratnam R , Gatter K
Published: December 2004

Aim:  To describe an unusual human immunodeficiency virus (HIV)‐associated lymphoma in uncommon sites. Plasmablastic lymphoma is a distinctive HIV‐associated tumour that was first described in the jaws and oral cavity. Only two cases (stomach and lung) have been documented in extra‐oral sites.

Materials and methods:  Four cases were encountered in HIV+ patients: three in the anorectal region and one which was nasal and paranasal. The cases were routinely processed and immunohistochemistry was performed on formalin‐fixed paraffin‐embedded tissue.

Results: The cases showed the typical morphological appearances of a high‐grade, blastic non‐Hodgkin's lymphoma (brisk mitotic activity and tingible body macrophages). In addition, some cells had a plasmacytoid appearance and paranuclear clearing. Immunophenotypically, the tumour cells were negative for LCA, CD20 and CD45RA. However, a small proportion of cells (5%) were immunoreactive for CD79a and the majority were positive with VS38c, indicative of plasma cell differentiation. Kappa light chain and IgG heavy chain restriction was also detected.

Conclusions: Plasmablastic lymphoma may occur in extra‐oral sites and has a characteristic immunophenotype including focal expression of CD31 by the neoplastic cells. Awareness of the absence of expression of conventional B‐cell markers and its presence in unusual sites should facilitate the diagnosis of plasmablastic lymphoma in HIV+ patients.
Sporadic colorectal cancers with defective mismatch repair display a number of specific morphological characteristics: relationship between the expression of hMLH1 and hMSH2 proteins and clinicopathological features of 273 adenocarcinomas
Authors: Chapusot C , Martin L , Mungra N , Rageot D , Bouvier A M , Kopp C Bonithon , Ponnelle T , Faivre J , Piard F
Published: December 2004

Aims:  The aim of this study was to assess the independent value of pathological criteria in the diagnosis of mismatch repair (MMR)‐defective sporadic colorectal cancers.

Methods and results: Resected colorectal adenocarcinomas (n = 273) were reviewed in order to identify a number of specific morphological features of MMR‐defective carcinomas. Of the 273 cases, 35.2% were right‐sided and 5.9% were poorly differentiated. Focal extracellular mucin secretion was seen in 5.1% of cases and a stromal follicular reaction in 4.6%. The expression of the two major MMR proteins hMLH1 and hMSH2 was studied by immunohistochemistry. Carcinomas were considered deficient in the MMR system when a loss of nuclear signal in neoplastic cells was observed for one of the proteins. Such an extinction was seen in 37 of the cases (13.6%). The hMLH1 protein was the one most frequently altered (86.5%). After multivariate analysis, three independent factors were significantly associated with MMR deficiency: proximal location [odds ratio (OR) = 9.30; 95% confidence interval (CI) 2.79, 30.98], the presence of a true stromal follicular reaction (OR = 13.60; 95% CI 2.98, 62.00) and poor differentiation (OR = 8.33; 95% CI 1.63, 40.32).

Conclusions: These results confirm that sporadic colorectal MMR‐defective adenocarcinomas display certain specific morphological characteristics. However, these pathological features are not sufficiently predictive and immunohistochemistry is needed to identify such tumours accurately.