bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxic response of hypoglossal motoneurones in the in vivo cat
Authors: Pierrefiche O. , Bischoff A. M. , Richter D. W. , Spyer K. M.
Published: September 2004

In current and voltage clamp, the effects of hypoxia were studied on resting and synaptic properties of hypoglossal motoneurones in barbiturate‐anaesthetized adult cats.

Twenty‐nine hypoglossal motoneurones with a mean membrane potential of −55 mV responded rapidly to acute hypoxia with a persistent membrane depolarization of about +17 mV. This depolarization correlated with the development of a persistent inward current of 0.3 nA at holding potentials close to resting membrane potential.

Superior laryngeal nerve (SLN) stimulation‐evoked EPSUPs were reduced in amplitude by, on average, 46%, while IPSUP amplitude was reduced by 31 %. SLN stimulation‐evoked EPSCs were reduced by 50–70%.

Extracellular application of adenosine (10 mm) hyperpolarized hypoglossal motoneurones by, on average, 5.6 mV, from a control value of –62 mV. SLN stimulation‐evoked EPSUPs decreased by 18% and IPSUPs decreased by 46% during adenosine application.

Extracellular application of the KATP channel blocker glibenclamide led to a blockade of a persistent outward current and a significant increase of SLN stimulation‐evoked EPSCs.

We conclude that hypoglossal motoneurones have a very low tolerance to hypoxia. They appear to be under metabolic stress even in normoxia and their capacity to activate protective potassium currents is limited when compared with other brainstem neurones. This may help to explain the rapid disturbance of hypoglossal function during energy depletion.
Cholecystokinin (CCK) regulates somatostatin secretion through both the CCK‐A and CCK‐B/gastrin receptors in sheep
Authors: Zavros Yana , Shulkes Arthur
Published: September 2004

Cholecystokinin (CCK) and gastrin both stimulate gastric somatostatin (SOM) secretion in vitro and thus have the potential to modulate their direct effects on the parietal cell. However, the relative potencies and the mechanisms of action of CCK and gastrin on SOM secretion in vivo have not been determined.

The objectives of the present study were to compare the in vivo potencies of the sulphated (s) and non‐sulphated (ns) forms of gastrin heptadecapeptide (G‐17) and CCK octapeptide (CCK‐8) on SOM secretion, and to determine the nature of the receptors involved by repeating the studies in the presence of the CCK‐A and CCK‐B/gastrin receptor antagonists L‐364,718 and L‐365,260, respectively. All experiments were performed in the chronically cannulated sheep.

Dose–response experiments revealed the following potencies for SOM secretion: G‐17s = CCK‐8s > G‐17ns ≫ CCK‐8ns. However, based on the plasma levels achieved and a higher metabolic clearance rate (MCR) for CCK, CCK‐8s was the most potent.

Both the CCK‐A and CCK‐B/gastrin receptor antagonists suppressed CCK‐8s‐stimulated SOM output. In contrast, G‐17s‐stimulated SOM output was inhibited by only the CCK‐B/gastrin receptor antagonist.

Both receptor antagonists increased basal plasma gastrin and CCK levels.

The predominant circulating SOM molecular form after both gastrin and CCK stimulation was SOM‐14.

In conclusion, the sulphated forms of CCK and gastrin are more potent than the non‐sulphated forms. Despite sharing a common biologically active carboxy terminus, CCK stimulates SOM secretion by both the CCK‐A and CCK‐B/gastrin receptors, while gastrin acts via the CCK‐B/gastrin receptor alone. These findings explain in part why CCK is a net inhibitor of gastric acid secretion in vivo.
Abnormal regional blood flow responses during and after exercise in human sympathetic denervation
Authors: Puvi‐Rajasingham Sharmini , Smith Gareth D. P. , Akinola Adeola , Mathias Christopher J.
Published: September 2004

Blood pressure, superior mesenteric artery (SMA) and skeletal muscle blood flow, cardiac index (CI) and systemic vascular resistance responses to supine leg exercise were measured in six age‐matched normal subjects (controls) and in eleven subjects with sympathetic denervation due to primary autonomic failure (AF).

During exercise, blood pressure rose in controls but fell markedly in AF. After exercise, blood pressure rapidly returned to baseline in controls but remained low in AF. During exercise, systemic vascular resistance fell in controls and AF but tended to fall further in AF and remained low post exercise. CI increased similarly in controls and AF.

During exercise, SMA blood flow fell similarly in controls and AF, but the fall initially was slower in AF; recovery was more rapid post exercise in controls. SMA vascular resistance tended to rise less and more slowly in AF and remained elevated post exercise.

Forearm muscle (FM) blood flow and FM vascular resistance did not change from resting values in controls or AF post exercise. After exercise, leg muscle (LM) blood flow rose and LM vascular resistance fell equally in both groups although LM blood flow remained elevated, 10 min post exercise in AF.

In sympathetically denervated humans, increased blood flow (due to excessive vasodilatation, lack of sympathetic restraint, or both) in leg muscle during and after exercise in combination with impaired splanchnic vasoconstriction in the early stages of exercise may have contributed to exercise‐induced hypotension.
Variation of electroencephalographic activity during non‐rapid eye movement and rapid eye movement sleep with phase of circadian melatonin rhythm in humans
Authors: Dijk Derk‐Jan , Shanahan Theresa L. , Duffy Jeanne F. , Ronda Joseph M. , Czeisler Charles A.
Published: September 2004

The circadian pacemaker regulates the timing, structure and consolidation of human sleep. The extent to which this pacemaker affects electroencephalographic (EEG) activity during sleep remains unclear.

To investigate this, a total of 1.22 million power spectra were computed from EEGs recorded in seven men (total, 146 sleep episodes; 9 h 20 min each) who participated in a one‐month‐long protocol in which the sleep–wake cycle was desynchronized from the rhythm of plasma melatonin, which is driven by the circadian pacemaker.

In rapid eye movement (REM) sleep a small circadian variation in EEG activity was observed. The nadir of the circadian rhythm of α‐activity (8.25–10.5 Hz) coincided with the end of the interval during which plasma melatonin values were high, i.e. close to the crest of the REM sleep rhythm.

In non‐REM sleep, variation in EEG activity between 0.25 and 11.5Hz was primarily dependent on prior sleep time and only slightly affected by circadian phase, such that the lowest values coincided with the phase of melatonin secretion.

In the frequency range of sleep spindles, high‐amplitude circadian rhythms with opposite phase positions relative to the melatonin rhythm were observed. Low‐frequency sleep spindle activity (12.25–13.0 Hz) reached its crest and high‐frequency sleep spindle activity (14.25–15.5Hz) reached its nadir when sleep coincided with the phase of melatonin secretion.

These data indicate that the circadian pacemaker induces changes in EEG activity during REM and non‐REM sleep. The changes in non‐REM sleep EEG spectra are dissimilar from the spectral changes induced by sleep deprivation and exhibit a close temporal association with the melatonin rhythm and the endogenous circadian phase of sleep consolidation.
Evidence showing that β‐adrenoceptor subtype responsible for the relaxation induced by isoprenaline is principally β2 but not β1 in guinea‐pig tracheal smooth muscle
Authors: Tanaka Y. , Yamashita Y. , Horinouchi T. , Yamaki F. , Koike K.
Published: September 2004

1 The present study was carried out to pharmacologically identify the β‐adrenoceptor subtype that mediates isoprenaline‐elicited relaxation in the isolated guinea‐pig tracheal smooth muscle, to answer the question whether it is β1‐ or β2‐subtype?

2 Isoprenaline as well as salbutamol, a well‐known β2‐selective adrenoceptor agonist, produced a concentration‐dependent relaxation with a pD2 value of 8.12 vs. 7.54 for salbutamol.

3 Isoprenaline‐elicited relaxation was not affected by β1‐selective antagonists, atenolol and CGP‐20,712A, within the concentration ranges supposed to antagonize β1‐subtype: atenolol, ≤10−6 m; CGP‐20,712A, ≤10−8 m.

4 By contrast, the concentration–response curves for isoprenaline as well as salbutamol were shifted rightwards in a competitive fashion by atenolol at the concentrations ≥3 × 10−6 m. However, pA2 values of atenolol against isoprenaline (5.86) and salbutamol (5.71) were consistent with the value corresponding to β2‐ but not to β1‐subtype (around 7.00), and these values were not significantly different from each other.

5 Competitive antagonism of the relaxations to isoprenaline and salbutamol were also obtained with β2‐selective antagonists, butoxamine and ICI‐118,551. Against isoprenaline and salbutamol, the pA2 values of butoxamine (6.51 vs. 6.81) and ICI‐118,551 (8.83 vs. 8.90) were substantially identical. Thus the primary mediation of β2‐receptor in the relaxations was strongly supported.

6 The present findings provide evidence that the β‐adrenoceptor which mediates isoprenaline‐elicited relaxation of guinea‐pig tracheal smooth muscle is essentially β2‐ but not β1‐subtype. The present study also indicates the importance of using multiple receptor antagonists with different pA2 values to pharmacologically identify the responsible receptor subtype in smooth muscle mechanical responses.
Functional alterations of mesenteric vascular bed, vas deferens and intestinal tracts in a rat hindlimb unloading model of microgravity
Authors: De Salvatore G. , Desaphy J.‐F. , Piepoli A. L. , Natale L. , De Salvia M. A. , Mitolo C. I. , Renna G. , Conte‐Camerino D. , Mitolo‐Chieppa D.
Published: September 2004

1 Prolonged bed rest or exposure to microgravity may cause several alterations in autonomic nervous system response (ANSR).

2 Hindlimb unloading (HU) rats were used as an animal model of simulated microgravity to investigate ANSR changes. The experiments were carried out to investigate the effects of simulated microgravity on the autonomic nervous response of the perfused mesenteric vascular bed (MVB), vas deferens and the colon and duodenum from 2‐week HU rats.

3 In MVB preparations of HU rats, the frequency‐dependent increases in perfusion pressure with perivascular nerve stimulation (PNS; 8–40 Hz) were inhibited, whereas the noradrenaline (NA) concentration‐dependent (1–100 μm) perfusion pressure increases were potentiated. The latter most probably reflected up‐regulation of α‐adrenergic receptor function. Relaxant responses of NA‐precontracted MVB to PNS (4–30 Hz) or isoprenaline were not different between control and HU preparations, while vasodilation induced by the endothelial agonist ACh was reduced.

4 Transmural stimulation (2–40 Hz) induced frequency‐dependent twitches of the vas deferens which were reduced in vas deferens of HU rats, while the sensitivity to NA‐induced contraction was significantly increased.

5 In the gastroenteric system of HU rat, direct contractile responses to carbachol or tachykinin as well as relaxant or contractile responses to nervous stimulation appeared unchanged both in the proximal colon rings and in duodenal longitudinal strips.

6 In conclusion, HU treatment affects peripheral tissues in which the main contractile mediators are the adrenergic ones such as resistance vessels and vas deferens, probably by reducing the release of neuromediator. This study validates NA signalling impairment as a widespread process in microgravity, which may most dramatically result in the clinical phenotype of orthostatic intolerance.
From Barricades to Firewalls? Strategic Voting and Social Movement Leadership in the Internet Age
Authors: Schussman Alan , Earl Jennifer
Published: September 2004

Strategic voting, which was frequently described as “Nader trading,” emerged during the 2000 U.S. Presidential Election as a way for voters to redefine their participation in the American electoral process. As a movement that emerged online, strategic voting not only presents potential political ramifications, but raises important issues for social movement scholars. In particular, movements that emerge online, which we refer to as “e‐movements,” may challenge movement theories based on offline, pre‐Internet forms of activism. In this paper, we use detailed data on the forms of strategic voting and the creators of the movement to address the literature on social movement leadership. We find that biography plays a strong role in the generation of strategic voting leaders, but in ways that differ from previous expectations about movement leadership processes. Further, we find that specific characteristics of leaders’ backgrounds also shape the forms of strategic voting implemented by leaders. We suggest a new institutionalist interpretation of this finding, arguing that scripts for appropriate forms of action generate diverse approaches to strategic voting.
Rural Housing Adequacy and Civic Structure
Authors: Morton Lois Wright , Allen Beverlyn Lundy , Li Tianyu
Published: September 2004

One persistent problem that many small rural towns face is housing adequacy, which encompasses interior and exterior structural conditions; assessments of heating, cooling, and sanitation systems; and residence size relative to space needs. The creation and reproduction of vibrant rural communities is grounded in the capacity of citizens to solve local housing problems. We posit that towns with strong norms of mutuality, high information flows, and inclusive behaviors have a civic structure that produces the capacity to frame and resolve housing concerns. We find that perceptions of civic structure are a significant factor in explaining the variation in rural housing adequacy, net of income, age, and tenure. This implies that the social and political environment is an important influence on the quality of housing stock found in rural places.
School‐Choice Stories: The Role of Culture
Authors: Bulman Robert C.
Published: September 2004

This article uses data from in‐depth interviews conducted with the parents of a sample of 88 ninth‐grade students from public, private, Catholic, and Christian high schools in two different suburban communities. This research investigates the ways in which parents understand education and how they make sense of schooling options for their children. It shows both how families who choose schools make the selection among various alternatives and why some families seem not to choose schools. This research finds that the financial and information resources of families are not enough in and of themselves to explain school‐choice behavior. While these resources are indeed used by families as they make school choices, such measures do not capture the cultural dimension of school choice. In this context culture is understood as the lens through which people make sense of the social world. The decision to activate resources and the direction in which those resources will be activated are mediated by culture. In particular, as these school‐choice stories show, the school‐choice decision is influenced by the past educational experiences of the parents and by their religious faith.
International Nongovernmental Organizations and Carbon Dioxide Emissions in the Developing World: A Quantitative, Cross‐National Analysis
Authors: Shandra John M. , London Bruce , Whooley Owen P. , Williamson John B.
Published: September 2004

This quantitative, cross‐national study is designed to test hypotheses linking the activities of international nongovernmental organizations to reductions in carbon dioxide emissions in the developing world. While many quantitative studies of variation in carbon dioxide emissions have been published, none have included a control for the presence of international nongovernmental organizations. We review the literature that discusses the many ways that international nongovernmental organizations work to reduce environmental degradation in developing nations. We then conduct a panel regression analysis in which we include a variable to estimate the effects of international nongovernmental organizations on carbon dioxide emissions while including variables suggested by other relevant theoretical perspectives. Our findings are quite clear in that nations with high levels of international nongovernmental organization presence have lower levels of carbon dioxide emissions than nations with low levels of international nongovernmental organization presence. We also find support for the ecological modernization hypothesis pertaining to the existence of an environmental Kuznet's curve between the level of economic development and level of carbon dioxide emissions.
DESCRIPTION OF THECADINIUM MUCOSUM SP. NOV. (DINOPHYCEAE), A NEW SAND‐DWELLING MARINE DINOFLAGELLATE, AND AN EMENDED DESCRIPTION OF THECADINIUM INCLINATUM BALECH1
Authors: Hoppenrath Mona , Saldarriaga Juan F. , Schweikert Michael , Elbrächter Malte , Taylor F. J. R.
Published: September 2004

A new thecate, phototrophic, marine, sand‐dwelling dinoflagellate, Thecadinium mucosum Hoppenrath et Taylor sp. nov., is described from a culture isolated from Boundary Bay, British Columbia, Canada. It was illustrated with LM as well as SEM and TEM, and its position in the phylogenetic tree of dinoflagellates was investigated using molecular methods. Cells are asymmetrical, oval, laterally flattened, and strongly pigmented, with the plate formula P 3′ 1a 6′′ 7/8c 5 s 6′′′ 2′′′′. Thecal plates are smooth with scattered pores, and there is a distinctive anterior intercalary plate that could be involved in mucus secretion. Thecadinium inclinatum Balech (=Sabulodinium inclinatum (Balech) Saunders et Dodge), a thecate, marine, sand‐dwelling species that has been previously confused with what we now call T. mucosum, was also examined and illustrated through LM and SEM. New information on T. inclinatum is provided, including its plate formula P 3′ 6′′ 7c ?s 5′′′ 1p 1′′′′; we consider T. inclinatum to be related to most other Thecadinium species and not to Sabulodinium. Molecular phylogenetic analyses based on the small subunit ribosomal gene of T. mucosum, T. kofoidii (the type species of the genus), and T. dragescoi weakly support earlier suspicions based on morphology that T. dragescoi is not a member of Thecadinium. Tabulational patterns of the species suggest a relationship to the genus Amphidiniopsis.
A NEW BROWN ALGAL ORDER, ISHIGEALES (PHAEOPHYCEAE), ESTABLISHED ON THE BASIS OF PLASTID PROTEIN‐CODING rbcL, psaA, AND psbA REGION COMPARISONS1
Authors: Cho Ga Youn , Lee Sang Hee , Boo Sung Min
Published: September 2004

The brown algal family Ishigeaceae currently includes a single genus, Ishige Yendo, with two species. The relationship of the family to other brown algal lineages is less studied in terms of their plastid ultrastructure and molecular phylogeny. We determined the sequences of rbcL from four samples of the two Ishige species and nine putative relatives and the psaA and psbA sequences from 37 representatives of the brown algae. Analyses of individual and combined data sets resulted in similar trees; however, the concatenated data gave greater resolution and clade support than each individual gene. In all the phylogenies, the Phaeophyceae was well resolved, the Ectocarpales being placed in a terminal position and the Ishigeaceae ending up in a basal position. From our ultrastructural study, we concluded that the pyrenoid is absent in the Ishigeaceae, despite the presence of a rudimentary pyrenoid in I. okamurae. These results suggest that the Ishigeaceae is an early diverging brown lineage. Our molecular and morphological data, therefore, lead us to exclude the Ishigeaceae from the Ectocarpales s.l., which have an elaborate pyrenoid, and to propose its own order Ishigeales ord. nov. The Ishigeales is distinguished by oligostichous structure of thalli, phaeophycean hairs formed within cryptostomata, unilocular sporangia transformed from terminal cortical cells, and plurilocular sporangia lacking sterile terminal cells. This study is the first to document the utility of the psaA and psbA sequences for brown algae and also the first report on the multigene phylogeny of the Phaeophyceae based on three protein‐coding plastid genes.
ANTARCTIC DISTRIBUTION, PIGMENT AND LIPID COMPOSITION, AND MOLECULAR IDENTIFICATION OF THE BRINE DINOFLAGELLATE POLARELLA GLACIALIS (DINOPHYCEAE)1
Authors: Thomson Paul G. , Wright Simon W. , Bolch Christopher J. S. , Nichols Peter D. , Skerratt Jennifer H. , McMinn Andrew
Published: September 2004

Polarella glacialis (Montresor et al.) was identified in Davis Station sea ice by morphological and DNA sequence comparison of cultures with those of the authentic strain P. glacialis CCMP 1383 isolated from McMurdo Sound. Cells and cysts of the Davis isolate (FL1B) were morphologically indistinguishable from P. glacialis, and comparison of the large subunit rDNA of both cultures demonstrated only 0.2% sequence divergence over 1366 base pairs. The photosynthetic pigments of P. glacialis (strains FL1B and CCMP 1383) were typical of dinoflagellates, with peridinin (contributing up to 31%) as the major accessory pigment. Extremely high levels of polyunsaturated fatty acids (PUFA, up to 76.3%) were characteristic of P. glacialis isolate FL1B. The high PUFA concentration of this species is thought to be an adaptation to survive the cold temperatures of the upper fast ice. The sterol profile of FL1B was atypical of dinoflagellates, with 4‐desmethylsterols (up to 79%) in greater abundance than 4α‐methyl sterols (up to 24%). 27‐Nor‐24‐methylcholest‐5,22E‐dien‐3β‐ol was identified as the principle sterol in P. glacialis, contributing up to 64% of the total sterol composition.
INFLUENCE OF POLYAMINES ON THE SPORULATION OF GRATELOUPIA (HALYMENIACEAE, RHODOPHYTA)1
Authors: Sacramento Alicia T , García‐Jiménez Pilar , Alcázar Rubén , Tiburcio Antonio F. , Robaina Rafael R.
Published: September 2004

Polyamines (PAs) such as putrescine (PUT), spermidine (SPD), and spermine (SPM) are ubiquitous aliphatic amines involved in widely varying physiological behavior, but particularly they are actively involved in cell growth, division, and differentiation during reproductive events in plants. The contents of PUT, SPD, and SPM in infertile and fertile thalli of the red macroalga Grateloupia sp. were compared, and the results revealed a significant decrease in quantity from infertile to fertile status. At the enzymatic level, l‐ornithine decarboxylase (ODC) was mainly detected, and l‐arginine decarboxylase activity was not diminished by the inhibition of ODC. The maximum enzymatic activities, within the range of activities observed, correlated with the lower levels of polyamines in fertile thalli. In culture, SPM promoted the maturation of cystocarps to the eventual liberation of spores from aseptic fertile explants. PAs accumulated in cultivated explants as compared with noncultivated, but exogenous SPM addition further increased the endogenous SPM. The addition of berenyl, cordycepin, cyclohexylamine, dicyclohexylamine, and aurintricarboxylic acid blocked the synthesis in culture at the level of PUT, and partially at SPD and SPM synthesis, but the addition of SPM restored the levels of SPD and SPM as SPM accumulated, and they appeared to interconvert each other. The results obtained suggest that the culture in presence of SPM restored a deficient SPM situation in fertile explants, thus promoting sporulation.
INFECTION OF THE BLOOM‐FORMING THECATE DINOFLAGELLATES ALEXANDRIUM AFFINE AND GONYAULAX SPINIFERA BY TWO STRAINS OF AMOEBOPHRYA (DINOPHYTA)1
Authors: Kim Sunju , Gil Park Myung , Yih Wonho , Coats D. Wayne
Published: September 2004

In autumn 2002, parasitic dinoflagellates of the genus Amoebophrya Koeppen infected populations of the bloom‐forming thecate dinoflagellates Alexandrium affine (Inoue and Fukuyo) Balech and Gonyaulax spinifera (Claparede and Lachmann) Diesing in coastal waters of Korea. Here we present the first documentation of Amoebophrya infections in A. affine and G. spinifera and use host–parasite cultures to provide information on parasite development and total generation times. Parasites of the two dinoflagellate hosts differed in their site of infection, developing in the cytoplasm of A. affine but in the nucleus of G. spinifera. Developmental stages of the parasite strains were similar to the previous descriptions of Amoebophrya spp. infecting other dinoflagellates. A prominent feature of Amoebophrya infection in A. affine from natural field samples was the presence of abnormal “giant cells” in the long chains formed by this host species. The characteristic green autofluorescence of Amoebophrya infections was not evident under blue light excitation until very late in the infection cycle of the A. affine–Amoebophrya sp. system but was detectable throughout the infection cycle in the G. spinifera–Amoebophrya sp. system. Despite the relatively long duration (2–10 min) of the emergence process of Amoebophrya spp. from these thecate hosts, total parasite generation times were shorter (53–55 h) than those previously reported for athecate host–parasite systems. These observations provide the basis for better assessing the impact of parasitism by Amoebophrya sp. as a significant loss factor for thecate dinoflagellate populations in Korean waters.
GENETIC VARIATION IN ASTERIONELLA FORMOSA (BACILLARIOPHYCEAE): IS IT LINKED TO FREQUENT EPIDEMICS OF HOST‐SPECIFIC PARASITIC FUNGI?1
Authors: De Bruin Arnout , Ibelings Bas W. , Rijkeboer Machteld , Brehm Michaela , Van Donk Ellen
Published: September 2004

Understanding of the genetic basis for susceptibility and resistance is still lacking for most aquatic host–parasite systems, for instance, for phytoplankton and their fungal parasites. Fungal parasites can have significant effects on phytoplankton populations, mainly through their ability to decimate algal host populations during epidemics. We used random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) analysis to study levels of genetic variation within a population of the freshwater diatom Asterionella formosa Hassall in relation to parasitism by the obligate, host‐specific, fungal parasite Zygorhizidium planktonicum Canter. The level of genetic variation within the A. formosa population in Lake Maarsseveen, The Netherlands was found to be high despite the presumed absence or very low frequency of sexual reproduction in this species, the limited gene flow, and the severity of parasite attack that would purge the population from susceptible genotypes. RAPD analysis revealed four distinct banding patterns, with 3 of 21 markers (14%) being polymorphic. In AFLP analysis, every single isolate of A. formosa showed a unique banding pattern, and 120 of the 210 AFLP markers (57%) were found to be polymorphic. Furthermore, character compatibility analysis revealed that sexual reproduction may be one of the mechanisms that generates and maintains genetic variation in the A. formosa population in Lake Maarsseveen. The presence of genetic variation in A. formosa was reflected in infection experiments, which showed that genetically different A. formosa strains differed in their susceptibility to various Z. planktonicum strains and that parasite strains differed in their ability to infect particular host strains.
INDUCIBLE COLONY FORMATION WITHIN THE SCENEDESMACEAE: ADAPTIVE RESPONSES TO INFOCHEMICALS FROM TWO DIFFERENT HERBIVORE TAXA1
Authors: Verschoor Antonie M. , Van Der Stap Irene , Helmsing Nico R. , Lürling Miquel , Van Donk Ellen
Published: September 2004

We studied the occurrence of colony formation within 40 different strains of Scenedesmaceae (Chlorococcales, Chlorophyta) in response to grazing‐released infochemicals from the herbivorous zooplankters Brachionus calyciflorus Pallas (Rotifera) and Daphnia magna Strauss (Cladocera). With the exception of two strains, all strains showed similar responses to both B. calyciflorus and D. magna infochemicals, either no response or inducible colony formation. Colony size was found to increase with B. calyciflorus infochemical concentration and could be described by a sigmoid function. The increase in colony size was more pronounced in the Scenedesmus species tested than in Desmodesmus species, which was probably due to higher threshold infochemical concentrations for colony induction in Desmodesmus. Therefore, the adaptivity of colony formation to the herbivory threat only holds above the threshold concentration for colony induction and as long as maximum colony size has not been attained. Taking this into account, our results suggest that inducible colony formation is a common adaptive response of many Scenedesmaceae to the threat of herbivory.
A PHYLOGENETIC STUDY OF PARASITIC GENERA PLACED IN THE FAMILY CHOREOCOLACACEAE (RHODOPHYTA)1
Authors: Zuccarello Giuseppe C. , Moon Debra , Goff Lynda J.
Published: September 2004

Red algal parasites are common and have a unique type of development in which parasite nuclei are transferred to host cells and “control” host cell development. Previous phylogenetic studies have concentrated on parasites closely related to their hosts, termed adelphoparasites. A second set of parasites, usually classified in a different family or tribe from their host, termed alloparasites, have not been studied phylogenetically. This study concentrates on the wholly parasitic family, the Choreocolacaceae (Gigartinales). Using small subunit rDNA sequence data, we found that all the parasites studied are within the same family as their host. Our data support the placement of Holmsella, species of which parasitize Gracilaria and Gracilariopsis, in the order Gracilariales and suggest that Holmsella is an old parasitic genus. Most other species of the Choreocolacaceae parasitize species of the Rhodomelaceae. The one exception is the hyperparasitism between Harveyella mirabilis (Reinsch) F. Schmitz et Reinke (Rhodomelaceae) and the parasite Gonimophyllum skottsbergii Setchell (Delesseriaceae). The parasites Bostrychiocolax australis Zuccarello et West and Dawsoniocolax bostrychiae (Joly et Yamaguishi‐Tomita) Joly et Yamaguishi‐Tomita are placed within the tribe Bostrychiae as are their hosts. Harveyella mirabilis has a single origin and has switched hosts several times during its passage between the Atlantic and Pacific Oceans. Evidence does not support the continued recognition of the family Choreocolacaceae. Our results also indicate that the distinction between adelphoparasites and alloparasites is unwarranted, with a continuum between newly evolved parasites closely related to their hosts and parasites less closely related to their hosts.
AUGOPHYLLUM, A NEW GENUS OF THE DELESSERIACEAE (RHODOPHYTA) BASED ON rbcL SEQUENCE ANALYSIS AND CYSTOCARP DEVELOPMENT1
Authors: Lin Showe‐Mei , Fredericq Suzanne , Hommersand Max H.
Published: September 2004

A new genus, Augophyllum Lin, Fredericq et Hommersand gen. nov. related to Nitophyllum, tribe Nitophylleae, subfam. Nitophylloideae of the Delesseriaceae, is established to contain the type species Augophyllum wysorii Lin, Fredericq et Hommersand sp. nov. from Caribbean Panama; Augophyllum kentingii Lin, Fredericq et Hommersand sp. nov. from Taiwan; Augophyllum marginifructum (R. E. Norris et Wynne) Lin, Fredericq et Hommersand comb. nov. (Myriogramme marginifructa R. E. Norris et Wynne 1987) from South Africa, Tanzania, and the Sultanate of Oman; and Augophyllum delicatum (Millar) Lin, Fredericq et Hommersand comb. nov. (Nitophyllum delicatumMillar 1990) from southeastern Australia. Like Nitophyllum, Augophyllum is characterized by a diffuse meristematic region, the absence of macro‐ and microscopic veins, procarps consisting of a supporting cell bearing a slightly curved four‐celled carpogonial branch flanked laterally by a cover cell and a sterile cell, a branched multicellular sterile group after fertilization, absence of cell fusions between gonimoblast cells, and tetrasporangia transformed from multinucleate surface cells. Augophyllum differs from Nitophyllum by the blades becoming polystromatic inside the margins, often with a stipitate cylindrical base, the possession of aggregated discoid plastids neither linked by fine strands nor forming bead‐like branched chains, spermatangia and procarps initiated at the margins of blades, not diffuse, and a cystocarp composed of densely branched gonimoblast filaments borne on a conspicuous persistent auxiliary cell with an enlarged nucleus. Analyses of the rbcL gene support the separation of Augophyllum from Nitophyllum. An investigation of species attributed to Nitophyllum around the world is expected to reveal other taxa referable to Augophyllum.
THE IMPORTANCE OF SHALLOW SEDIMENTS IN THE RECRUITMENT OF ANABAENA AND APHANIZOMENON (CYANOPHYCEAE)1
Authors: Karlsson‐Elfgren Irene , Brunberg Anna‐Kristina
Published: September 2004

Recruitment of Anabaena and Aphanizomenon from the sediments to the water column was investigated in shallow (1–2 m) and deep (6–7 m) areas of Lake Limmaren, central Sweden. Recruitment traps attached to the bottom were sampled weekly throughout the summer season (June through September). A comparison between the two sites shows that the largest part of the recruited cells originated from the shallow site, although recruitment occurred at all depths in the lake. There were also differences between the species, regarding the site as well as the timing of the recruitment. The contribution of the inoculum to the pelagic population was calculated to vary between 0.003% and 0.05% for the different species. From these results we conclude that shallow sediments are more important than deep ones for the recruitment and that the inoculum in Lake Limmaren is small but may still be an important factor in the population dynamics.
Development of hepatosplenic γδ T‐cell lymphoma with pancytopenia during early pregnancy: a case report and review of the literature
Authors: Niitsu Nozomi , Kohri Mika , Togano Tomiteru , Nakamine Hirokazu , Nakamura Shigeo , Iwabuchi Kei‐ichi , Higashihara Masaaki
Published: September 2004

Abstract:  Lymphomas rarely develop during pregnancy, but hepatosplenic γδ T‐cell lymphoma (HSγδTCL) is extremely rare. We encountered a case of T‐cell intracellular antigen‐1 (TIA‐1) positive and granzyme B‐positive HSγδTCL that developed early during the course of pregnancy. The patient was a 31‐yr‐old female who was referred to our hospital because of pancytopenia and splenomegaly at the time of the14th week of her gestation. Her pancytopenia and hepatosplenomegaly worsened and she became fibril at the 27th week of gestation and Cesarean section was performed at the 29th week. Histopathological examination of the spleen, which was resected 28 d after delivery for a diagnostic purpose, revealed medium to large‐sized nodules composed of dense proliferation of lymphoid cells having round to oval‐shaped nuclei and abundant weakly eosinophilic cytoplasm. They were CD3ɛ+, mCD3+, CD4−, CD8−, CD56+, CD79a−, T‐cell receptor (TCR)‐γδ protein+, TIA‐1+, and granzyme B+ by either immunohistochemistry or flow cytometry. Clonal rearrangement of TCR‐γ genes without such rearrangement of TCR‐δ and TCR‐β genes was confirmed by Southern blot hybridization. Thus, the patient was diagnosed as having HSγδTCL, and combination chemotherapy was initiated. She is currently in partial remission. To our knowledge, this is the first case report of HSγδTCL that developed during pregnancy. Pathogenesis of pregnancy‐associated lymphoma is not known, but it is possible that maternal immunity during pregnancy or a hormonal imbalance, such as a change in the progesterone level, induces the development of lymphoma. Pregnancy‐associated lymphoma is resistant to standard chemotherapy and is associated with poor prognosis. Therefore, it is important to accumulate clinicopathologic data of such cases for the development of a treatment modality.
Flow cytometric detection of accelerated telomere shortening in myelodysplastic syndromes: correlations with aetiological and clinical–biological findings*
Authors: Rigolin Gian Matteo , Porta Matteo Della , Bugli Anna Maria , Castagnari Barbara , Mauro Endri , Bragotti Letizia Zenone , Ciccone Maria , Cuneo Antonio , Castoldi Gianluigi
Published: September 2004

Abstract:  Using quantitative fluorescence in situ hybridisation and flow cytometry (flow‐FISH), we investigated the biological and clinical relevance of telomere length in 55 patients affected by myelodysplastic syndromes (MDS) compared with 55 sex‐ and age‐matched controls. We found that telomere fluorescence in MDS granulocytes, and CD34+ cells did not decline with age as in normal controls and that MDS granulocytes and CD34+ cells had significantly shorter telomeres than healthy controls. A significant higher incidence of cases with intermediate‐unfavourable cytogenetics and International Prognostic Scoring System (IPSS) int‐2/high‐risk group was observed among patients with lower telomere fluorescence. We also found that apoptosis in CD34+ cells was significantly higher in IPSS int‐1 low‐risk patients when compared with IPSS int‐2 high‐risk cases and healthy controls and that CD34+ cell telomere fluorescence directly correlated with CD34+ cell apoptosis. Reduced telomere fluorescence was associated with a history of occupational exposure to toxic agents and with worse survival in univariate and multivariate analyses. Our results suggest that flow‐cytometry assessment of telomere dynamics may represent a valuable tool in the biological and clinical–prognostic characterisation of MDS disorders.
Lipoteichoic acid derived from Enterococcus faecalis modulates the functional characteristics of both normal peripheral blood leukocytes and native human acute myelogenous leukemia blasts
Authors: Bruserud Øystein , Wendelbo Øystein , Paulsen Kristin
Published: September 2004

Abstract:  Objectives: Several case reports have described complete hematological remissions for patients with otherwise untreated acute myelogenous leukemia (AML) who receive hematopoietic growth factor therapy during complicating bacterial infections. This may be caused by indirect cytokine effects, but direct effects of infecting agents on the malignant cells are also possible because bacterial molecules can bind to specific receptors expressed by normal and malignant leukocytes. Lipoteichoic acid (LTA) is a cell wall component of gram‐positive bacteria, and it can activate normal immunocompetent cells through binding to specific cell membrane receptors. Methods: We investigated effects of LTA derived from Enterococcus faecalis on in vitro cultured (i) normal peripheral blood mononuclear cells (PBMC); (ii) remaining T cells derived from patients with hematologic malignancies and chemotherapy‐induced leukopenia; and (iii) native human AML cells. Results: Increased interleukin 1β (IL1β) and IL8 release by in vitro cultured normal PBMC was observed after stimulation with LTA at concentrations ≥5 μg/mL; these levels were lower than for lipopolysaccharide (LPS)‐stimulated cells and LTA antagonized LPS‐induced cytokine release by normal PBMC. In most cases LTA did not alter T‐cell proliferation for patients with chemotherapy‐induced leukopenia. The LTA effects on AML blasts were investigated for 62 consecutive patients. LTA altered either cytokine (granulocyte‐macrophage colony‐stimulating factor + stem cell factor + IL3)‐dependent proliferation or the release of IL1β/IL8 for 23 patients; the effects were divergent but increased proliferation/cytokine levels were most commonly observed. Conclusion: The LTA derived from E. faecalis can modulate the functional characteristics of normal leukocytes and native human AML blasts.
Adult T‐cell leukemia predominantly involving exocrine glands
Authors: Obama Kosuke , Saito Mineki , Higuchi Itsuro , Tara Mitsutoshi , Niina Kiyoshige , Osame Mitsuhiro
Published: September 2004

Abstract:  Objectives: We describe a rare case of adult T‐cell leukemia (ATL) presenting with dry mouth and swelling of bilateral parotid and submandibular glands. The unusual involvement of these exocrine glands by malignant cells prompted us to conduct a detail characterization of these infiltrating and circulating leukemic T cells, which may provide insight to the pathogenesis of exocrine involvement in ATL. Methods: Immunophenotyping of peripheral ATL cells and microscopic examinations of various organs prepared by autopsy were performed. Analysis of the repertoire of T‐cell receptor (TCR) of parotid gland‐infiltrating ATL cells using molecular and immunohistochemical examinations were also performed. Results: Microscopic examinations of various organs prepared by autopsy revealed the predominant and specific exocrine gland infiltration of ATL cells. Reverse transcription‐polymerase chain reaction (RT‐PCR) followed by both TCR spectratyping and complementary determining region (CDR)‐3 sequencing analysis of TCR Vβ of parotid gland‐infiltrating T cells revealed a relatively restricted but not single usage of TCR Vβ. Immunohistochemical analyses of parotid gland specimens detected only a small number of TCR Vαβ‐positive cells in parotid gland‐infiltrating ATL cells. Conclusions: The predominant infiltration of ATL cells in exocrine glands implied that these T cells recognized exocrine gland‐specific antigen. However, the absence of both TCR Vβ mRNA transcripts and TCR Vαβ protein expression in most ATL cells suggested that antigen recognition via TCR may not have played a major role in adhesion and subsequent infiltration into the exocrine glands in this patient. These results provide important background information to further elucidate the pathogenesis of exocrine gland‐specific inflammation.
Prognostic significance of vascular endothelial growth factor immunoexpression in the context of adverse standard prognostic factors in multiple myeloma
Authors: Ribas Christian , Colleoni Gisele W. B. , Silva Maria Regina Regis , Carregoza Maria José , Bordin José Orlando
Published: September 2004

Abstract: Objectives: Vascular endothelial growth factor (VEGF) acts in several steps of multiple myeloma (MM) pathogenesis and it is an important mediator of tumor angiogenesis. The aim of this study was to examine the prognostic significance of VEGF immunoexpression in the context of standard prognostic factors present in a cohort of advanced MM patients.Methods: Fifty untreated MM patients were enrolled from May 2000 to December 2002. Bone marrow sections were subjected to morphologic assessment and immunohistochemical studies with antibodies against CD34 and VEGF. Angiogenesis was measured by microvessel density (MVD) and stratified into high (MVD ≥ 20) and low angiogenesis status (MVD < 20). VEGF immunoreactivity was examined on the basis of intensity and percentage of positive plasma cells (PC).Results: Ninety‐four percent of patients presented advanced disease at diagnosis. Median PC marrow infiltration was 80%. Twelve percent of patients presented plasmablastic morphology. Low angiogenesis was present in 27% of patients, while high angiogenesis was present in 73%. Twenty‐nine percent of patients had VEGF < 10% and 71% had VEGF ≥ 10%. Weak‐intensity VEGF was observed in 34% of cases, while 37% had moderate/strong VEGF intensity. Although VEGF had prognostic impact on overall survival (OS) and event‐free survival (EFS) in univariate analysis, multivariate analysis identified only plasmablastic morphology and elevated serum lactate dehydrogenase (LDH) level as independent prognostic factors to predict OS (P = 0.04 andP = 0.02, respectively). With regard to EFS, although VEGF showed statistical trend to influence survival (P = 0.08), the parameters of independent prognostic value were also plasmablastic morphology (P = 0.01) and elevated LDH level (P = 0.01).Conclusion: Our findings underline the frequent expression of VEGF in advanced‐stage MM and the greater prognostic information of simple and readily available factors, namely plasmablastic morphology and elevated LDH. Moreover, despite the absence of prognostic importance in multivariate analysis, VEGF and its receptors remain promising therapeutic targets in MM.
Is higher income and educational status associated with poorer outcome in patients with Hodgkin's disease?
Authors: Holzner Bernhard , Fischhofer Martina , Kemmler Georg , Kopp Martin , Sperner‐Unterweger Barbara , Krugmann Jens , Dirnhofer Stephan , Greil Richard
Published: September 2004

Abstract:  Objectives: The aim of the study was to determine the impact of socioeconomic status on relapse‐free survival (RFS) in patients with Hodgkin's disease. Methods: A number of factors were analyzed for their impact on relapse‐free and overall survival in Hodgkin's disease using Cox regression. These factors included socioeconomic status (as defined by education and income), different treatment modalities and established clinical risk factors [e.g. age at diagnosis, stage of disease, involvement of three or more lymph nodes, presence or absence of a large mediastinal mass, E stages or elevation of erythrocyte sedimentation rate (ESR)]. The study used an initial sample of 126 patients recruited between 1969 and 1995 and a larger sample of 218 patients (recruited until 2002). Clinical data on disease and treatment characteristics were collected from medical records. Results: In a univariate analysis, the following parameters had impact on RFS: treatment modality (combined treatment resulted in an improved RFS compared with patients treated with chemo‐ or radiotherapy alone), educational status and income. The 5‐ and 10‐yr relapse‐free survival rates were found to increase with decreasing educational level and decreasing average income per month. These results were significant in the initial and total samples and were also significant using multivariate analysis (hazard ratio for highest vs. lowest education group: 5.88; 95% confidence interval 1.87–18.52; for highest vs. lowest income group: 4.36; 95% confidence interval 1.35–14.05). Conclusion: Hodgkin's disease appears to be a striking exception from the usual positive correlation between high socioeconomic status and favorable treatment outcome in patients suffering from tumor. It is suggested that future studies on tumor genetics and biology and more detailed analysis of further socioeconomic parameters may be useful in clarifying this observation.
Acquired amegakaryocytic thrombocytopenia associated with proliferation of γ/δ TCR+ T‐lymphocytes and a BCR‐ABL (p210) fusion transcript
Authors: Colovic Milica , Pavlovic Sonja , Kraguljac Nada , Colovic Natasa , Jankovic Gradimir , Sefer Dijana , Tosic Natasa
Published: September 2004

Abstract:  Acquired amegakaryocytic thrombocytopenia (AATP) in adults is a rare disorder characterized by severe thrombocytopenia and decreased or absent megakaryocytes in an otherwise normal bone marrow. We present a 44‐yr‐old man in whom the diagnosis of AATP was established in January 2001. Immunophenotyping of the peripheral blood lymphocytes showed a relative increase in the subpopulation of gamma/delta T‐cell receptor (TCR) positive (γ/δ TCR+) and (CD4, CD8) negative T lymphocytes, and PCR suggested a monoclonal pattern of TCR gamma chain gene rearrangement. Cytogenetic examination of his bone marrow cells showed a normal male karyotype but RT‐PCR analysis revealed a BCR‐ABL (p210) fusion transcript. The inhibition of CFU‐Mk growth mediated by the patient's T lymphocytes indicated that the pathogenic mechanism for AATP could be an immunological attack on megakaryocyte progenitors where the γ/δ TCR‐positive T lymphocytes are directly involved. The case emphasizes the complex association of T‐lymphocyte monoclonal proliferation and AATP.
Prolonged course of pure red cell aplasia after erythropoietin therapy
Authors: Nigg L. , Schanz U. , Ambühl P. M. , Fehr J. , Bachli E. B.
Published: September 2004

Abstract:  Pure red cell aplasia (PRCA) caused by neutralising anti‐erythropoietin antibodies is a very rare disease. Since 1998, an increased incidence of PRCA in patients with kidney failure following treatment with recombinant human erythropoietin (rhEpo) has been reported, mostly in Europe. In most cases, PRCA was cured by immunosuppressive therapy, immunoglobulins, plasmapheresis or renal transplantation. We report an exceptionally prolonged course of PRCA over 68 months despite renal transplantation and different immunosuppressive regimens.