bluuebunny/crossref_metadata_2025 huggingface dataset:
GROWTH AND PHOTOSYNTHESIS OF ULVA ROTUNDATA (CHLOROPHYTA) AS A FUNCTION OF TEMPERATURE AND SQUARE WAVE IRRADIANCE IN INDOOR CULTURE1
Authors: Henley William J.
Published: October 2004

Temperature and photon flux density (PFD) vary independently in estuaries, e.g. high PFD may occur at any temperature, so it is necessary to consider synergistic effects of these factors on algal growth. Because natural PFD is highly variable and daylength changes confound seasonal temperature cycles, it is easier to interpret factorial experiments in controlled laboratory conditions. Clonal Ulva rotundata Blid. (Chlorophyta) has been studied extensively in outdoor culture. In this study it was maintained indoors under square wave photoperiods at five PFDs and three temperatures. Growth rate, photqsynthetic light response (P‐I) curves, and photosystem II chlorophyll fluorescence properties were measured at the growth temperature following acclimation. Interactions between PFD and growth temperature were strongly indicated in all physiological parameters measured. Greatest PFD response occurred at the highest temperature, and the largest temperature response occurred at the highest PFD. Light‐saturated photosynthesis (Pm) dark respiration (Rd), and light‐limited quantum yield (Φm) were sufficient to describe acclimation status. The light‐saturation parameter (Ik) was redundant and potentially misleading. Although U. rotundata exhibits a great amplitude of photoacclimation, it apparently has little capacity for temperature acclimation compared to the kelp, Laminaria saccharina, for which published data indicate similar photosynthetic rates over a broad range of growth temperatures. Diurnal variation of Pm and Rd at a growth PFD of ∼ 1700 ± 200 μmol photons · m−2· s−1 was similar to the pattern observed previously in outdoor culture, suggesting endogenous control of these parameters. Quantum yield and the ratio of variable to maximum chlorophyll fluorescence (Fv/Fm), which were depressed in midday sunlight exceeding ∼ 1500 μmol photons · m−2· s−1, were relatively invariant through the day in indoor culture, indicating that these parameters are controlled primarily by instantaneous PFD. Growth and fluorescence data are also presented for some other macroalgae for comparative purposes.
ULTRASTRUCTURE OF VEGETATIVE ORGANIZATION AND CELL DIVISION IN THE UNICELLULAR RED ALGADIXONIELLA GRISEAGEN. NOV. (RHODOPHYTA) AND A CONSIDERATION OF THE GENUSRHODELLA1
Authors: Scott Joseph L. , Broadwater Sharon T. , Saunders Bill D. , Thomas Jewel P. , Gabrielson Paul W.
Published: October 2004

This study suggests that the genusRhodellabe restricted to that set of features currently observed only inRhodella maculataEvans andRhodella violacea(Korn‐mann) Wehrmeyer, that a new genusDixoniellabe established to accommodate the unicellular red alga,Rhodella grisea(Geitler) Fresnel, Billard, Hindák et Pekár‐ková, and thatRhodella cyaneaBillard et Fresnel be further studied for probable reclassification. These conclusions are based on ultrastructural comparisons ofDixoniella griseawith published information on the genusRhodella.The presence of thylakoids in the pyrenoid, a peripheral encircling thylakoid in the chloroplast, a dictyosome/nuclear envelope association, and the lack of a specialized pyrenoid/nucleus association inD. griseaseparate this alga from the genusRhodella.Cell division inD. griseais not demonstrably different from that inRhodella, although the unusually well‐defined material of the presumptive microtubule organizing center (MTOC) made it possible to follow the development and behavior of the MTOC to a greater degree than in previously studied red algal cells. The surprising amount of conformity in cell division characters betweenD. griseaand the genusRhodellaprompted a comparison of cell division characteristics in all red algal unicells studied to date.

All unicells show a remarkable degree of similarity except for differences in interzonal spindle length, dissimilarities in size of the nucleus‐associated organelle (NAO), and the unusual NAO ofPorphyridium purpureum(Bory) Drew et Ross.
BIOGEOGRAPHY OF CLADOPHOROPSIS MEMBRANACEA (CHLOROPHYTA) BASED ON COMPARISONS OF NUCLEAR rDNA ITS SEQUENCES1
Authors: Kooistra Wiebe H. C. F. , Stam Wytze T. , Olsen Jeanine L. , van den Hoek Chris
Published: October 2004

Nucleotides were compared at 988 sites, spanning both internal transcribed spacers (ITS1 and ITS2) of the nuclear ribosomal DNA, among 17 isolates of the green alga Cladophoropsis membranacea (Hofman Bang ex C. Agardh) Boergesen and two isolates of Struvea anastomosans (Harvey) Piccone and Grunow. Collections were made from Bonaire, Curaçao, St. Croix, the Canary Islands, the Cape Verde Islands, Mauritania, Syria, the Red Sea, Okinawa, and Hawaii. Two nucleotide substitutions were found between the sequenced coding regions of C. membranacea and S. anastomosans. Of the 720 nucleotides compared in ITS1 and ITS2, an average of 6.7% sequence divergence was found within C. membranacea and 17.4% between C. membranacea and S. anastomosans. Sequences were analyzed using maximum parsimony. Phylogenetic hypotheses were compared with the biogeographic hypothesis of an east‐west Tethyan vicariance. Results of the study allow the identification of widely dispersed biogeographic populations, the identification of an underlying Tethyan imprint, and support for the hypothesis that dispersal has occurred between the Caribbean and the tropical eastern Atlantic. These results demonstrate the usefulness of ITS sequences at the sub‐specific level in C. membranacea.
CULTURE STUDIES ON THE LIFE HISTORY OF CHORDARIA LINEARIS (PHAEOPHYCEAE) FROM TIERRA DEL FUEGO, SOUTH AMERICA1
Authors: Peters Akira F.
Published: October 2004

Studies of laboratory cultures of Chordaria linearis (Hooker et Harvey) Cotton from southernmost South America revealed that this species has an obligate sexual life history in which a macroscopic sporophyte alternates with a monoecious microscopic gametophyte. Sexual reproduction is isogamous and under photoperiodic control. Gametes are produced only in short days, whereas in long days, asexual zoospores are formed that recycle the gametophyte generation. Unfused gametes develop into gametophytes, and sporophytes originate only from zygotes. Unlike other sexual members of the Chordariales, gametes of C. linearis have a reduced stigma and do not show phototaxis. They are released at the beginning of the night, not in the morning. In nature, C. linearis seems to be regularly infected by a dictyosiphonalean epiphyte resembling the rare arctic species Trachynema groenlandicum (Lund) Pedersen. The epiphyte is responsible for previous contradictory results obtained in laboratory cultures of C. linearis. This is the first record of Trachynema in the southern hemisphere.
LYNGBYAINFESTATIONS: COMPARATIVE TAXONOMY OFLYNGBYA WOLLEICOMB. NOV. (CYANOBACTERIA)1
Authors: Speziale Barbara J. , Dyck Lawrence A.
Published: October 2004

Conflicting taxonomic identifications of an extremely large‐celled (width: 24.9–64.4 μm, length: 2.0–11.5 μm), filamentous, mat‐forming cyanobacterium prompted a search for an accurate taxonomic identity. This alga was reported by various workers asPlectonema wolleiFar‐low ex Gomont,Lyngbya majusculaHarvey ex Gomont,Lyngbya magnificaGardner,Lyngbya birgeiSmith,Lyngbya latissimaPrescott, andMicrocoleus lyngbyaceus (Kützing)Crouan sensu Drouet. Quantitative analyses of cellular morphology, evaluation of habitat preference, and growth form were used to characterize the organism. Descriptions and taxonomic histories of this organism and the six described taxa were compared.

The organism is identified asPlectonema wolleiFar‐low ex Gomont according to most existing botanical taxonomic systems. However, this identification places undue emphasis on the extremely variable characteristic of false branching, which varies seasonally and with growth status. To eliminate the confusion inherent in basing taxonomy upon an environmentally variable characteristic, identification asLyngbya wollei(Farlow ex Gomont) comb. nov. is recommended.
CHRONIC EFFECTS OF ULTRAVIOLET‐B RADIATION ON GROWTH AND CELL VOLUME OF PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE)1
Authors: Behrenfeld Michael J. , Hardy John T. , Lee Henry
Published: October 2004

Cultures of the temperate estuarine diatom, Phaeodactylum tricornutum Bohlin (NEPCC Clone 31), were grown under ambient intensities of ultraviolet‐A radiation (UVAR), photosynthetically active radiation (PAR), and various intensities of ultraviolet‐B radiation (UVBR; 290–320 nm). Growth rates and cell volumes were monitored for 36 d. UVBR decreased growth rates and increased cell volumes. Sensitivity of growth to UVBR increased with time. Growth rates of P. tricornutum decreased with increasing ratios of UVBR:UVAR + PAR.
EFFECTS OF DESICCATION AND ILLUMINATION ON PHOTOSYNTHESIS AND PIGMENTATION OF AN EDAPHIC POPULATION OF TRENTEPOHLIA ODORATA (CHLOROPHYTA)1
Authors: Ong Bee‐Lian , Lim Melin , Wee Yeow‐Chin
Published: October 2004

The photosynthetic rates of Trentepohlia odorata (L.) Martius growing on wall surfaces in Singapore changed throughout the day with a maximum in midmorning and decreasing thereafter during the day. Optimum temperature for photosynthesis was 25° C. Different levels of air humidity also affected photosynthetic rates with low relative humidity reducing the rates and efficiency of photosynthesis. Our results suggested that T. odorata was able to maximize its rate of photosynthesis before photoinhibitory light levels were reached and that its growth might be dependent on high levels of atmospheric relative humidity, which may serve as a source of water supply for the alga.
EFFECT OF NITROGEN STARVATION ON THE BIOCHEMISTRY OF PHORMIDIUM LAMINOSUM (CYANOPHYCEAE)1
Authors: Fresnedo Olatz , Serra Juan L.
Published: October 2004

Cells of the non‐N2‐fixing cyanobacterium Phormidium laminosum (Agardh) Gomont (strain OH‐1‐pCl1) showed doubling times of 24 h in media containing nitrate and 120 h in media without a nitrogen source. Nitrogen starvation resulted in a drastic decrease in the cellular content of chlorophyll, phycobiliproteins (phycocyanin and allophycocyanin), and other soluble proteins, although the total protein of cells was unchanged. N‐starved cells showed an exocellular layer of mucilage that rapidly increased with starvation time. The appearance of N deficiency symptoms was strongly dependent on culture conditions, and it was faster under the optimal conditions used for cell growth. The relative content of C and N of nitrate‐grown cells remained more or less constant during all growth phases (C/N ratio of ca. 5) but diminished at different rates in N‐starved cells. Cells subjected to N starvation for 48 h had a C/N ratio of more than 10. N starvation also resulted in the selective degradation of soluble poly‐peptides of masses lower than 20 kDa (which include those constituting phycobiliproteins), whereas the relative content of soluble polypeptides of greater size increased.
THE CONTRACTILE VACUOLE AS AN ENDOCYTIC ORGANELLE OF THE CHLAMYDOMONAD FLAGELLATE GLOEOMONAS KUPFFERI (VOLVOCALES, CHLOROPHYTA)1
Authors: Domozych David S. , Nimmons Trevor T.
Published: October 2004

The endomembrane system of the chlamydomonad flagellate, Gloeomonas kupfferi Skuja, consists of a complex network of endoplasmic reticulum, Golgi bodies, and various vacuoles. One of the more distinct vacuolar components is the contractile vacuole (CV) complex, which consists of two anterior contractile vacuoles that expand/contract approximately every 30 s. In this study, experimental cytochemical labeling was performed to help elucidate possible endocytic/membrane recycling mechanisms in Gloeomonas and the possible role of the contractile vacuole in this process. When incubated with 0.5 mg · mL−1 cationic ferritin for short periods of time (2–60 min), labeling follows this route: inner membrane of CV, globular deposits in the CV and associated vesicles, and ultimately the terminal trans face cisternae of the Golgi apparatus (GA). Similar incubations with Lucifer yellow and concanavalin A—gold conjugates support distinct uptake of exogenous ligands by the CV and associated vesicles. Our results suggest that the contractile vacuole may be a site of endocytosis and that the trans GA loci may be a key site of membrane recycling.
NUCLEAR RIBOSOMAL DNA INTERNAL TRANSCRIBED SPACER REGIONS (ITS1 AND ITS2) DEFINE DISCRETE BIOGEOGRAPHIC GROUPS IN CLADOPHORA ALBIDA (CHLOROPHYTA)1
Authors: Bakker Freek T. , Olsen Jeanine L. , Stam Wytze T. , van den Hoek Chris
Published: October 2004

Nucleotide sequences of the nuclear ribosomal DNA internal transcribed spacers (ITS1 and ITS2), the 5.8S, and short stretches of the adjacent 18S and 26S coding regions were determined in isolates from four disjunct Cladophora albida (Huds.) Kütz. populations (NE‐America, W‐Europe, Japan, and W‐Australia). The two Pacific isolates share nearly identical ITS sequences as do the two Atlantic isolates. In contrast, interoceanic comparisons exhibit a 21% sequence difference. Variation within ITS regions is useful for identification of population groups on a regional or oceanic scale. However, both spacers are characterized by numerous repeat motifs as well as point mutations, which result in alignment problems at the interspecific level within Cladophora.
Altered glycosylation leads to Tr polyagglutination
Authors: Halverson G.R. , Lee A.H. , Øyen R. , Reiss R.F. , Hurlet‐Jensen A. , Reid M.E.
Published: October 2004

BACKGROUND:  Polyagglutination refers to red blood cells (RBCs) that are agglutinated by a high proportion of ABO‐matched adult sera but not by cord sera. Polyagglutinable RBCs have been associated with microbial infection, myeloproliferative disorders, and myelodysplasia. Lectins aid in the identification of polyagglutination.

CASE STUDY:  A Hispanic male infant with mild hemolytic anemia, a “Bernard‐Soulier‐like” syndrome, intermittent neutropenia, mitral valve regurgitation, ligament hyperlaxity, and mild mental retardation was studied. The patient's Group O RBCs were polyagglutinable; they were agglutinated by normal human sera, several lectins [including Arachis hypogea, Salvia sclarea, Salvia horminum, Glycine max, Ulex europaeus, Griffonia simplicifolia I, and Gr. simplicifolia II], and some monoclonal antibodies. His RBCs were not agglutinated by cord sera, Dolichos biflorus, or Phaseolus lunatus. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis on the RBC membranes followed by staining with periodic acid‐Schiff stain showed markedly reduced staining of glycophorins A and B. Staining with Coomassie brilliant blue revealed that Band 3 has a faster mobility than normal.

CONCLUSIONS:  Collectively, the results suggest that the patient's RBCs have a reduction in N‐acetylneuraminic acid on both N‐ and O‐glycans, exposing, respectively, β1,4‐galactosidase and β1,3‐galactosidase. The patient likely has an altered glycosyltransferase that results in defective glycosylation in RBCs and other cell lineages. This type of polyagglutination was named Tr.
A survey of occupational hand eczema in Denmark
Authors: Skoet Rikke , Olsen Jorn , Mathiesen Bent , Iversen Lars , Johansen Jeanne Duus , Agner Tove
Published: October 2004

Occupational hand eczema (OHE) is the most frequently recognized work‐related disease in Denmark and the annual cost to society is high. Understanding of the epidemiology of OHE is essential to be able to give appropriate recommendations for its prevention. The study comprised 758 persons, 490 females and 268 males with recognized OHE in the period October 2001 to November 2002. Data were obtained prospectively from the National Board of Industrial Industry Registry and from a self‐administered questionnaire (response rate, 82%). The most frequently recognized diagnosis was irritant contact dermatitis (ICD), mainly caused by wet occupations. The proportion of occupational ICD was equal for males and females, 59.7% and 63.1%, respectively. The estimated rates of OHE were high for bakers, hairdressers and dental surgery assistants, and a high proportion of apprentices were found among hairdressers. The prevalence of atopic dermatitis was low (16.4%) compared to previous studies among hand eczema patients. The prevalence of occupational allergic contact dermatitis in the study population was substantially higher among males than females, and the most frequent causes among males were allergy to chromium (leather exposure), rubber additives (gloves) and nickel due to exposure from work tools and metalworking industry.
Multicentre patch test study of air‐oxidized ethoxylated surfactants
Authors: Matura Mihaly , Bodin Anna , Skare Lizbet , Nyrén Miruna , Hovmark Anders , Lindberg Magnus , Lundeberg Lena , Wrangsjö Karin , Karlberg Ann‐Therese
Published: October 2004

Frequent exposure to water and surfactants is considered to be the main cause of hand eczema from wet work. Ethoxylated surfactants are susceptible to oxidation and some of the oxidation products formed have proved to be contact sensitizers in guinea pigs. The question of human sensitization to oxidized surfactants was addressed in a multicentre study in the Stockholm region. 528 consecutive dermatitis patients were patch tested with widely used ethoxylated surfactants in oxidized and non‐oxidized form as well as certain identified oxidation compounds. 61 patients presented with mild, clearly irritant reactions to some of the surfactants tested. 18 patients showed not only erythema but also oedema and/or papules and vesicles, using a morphologic descriptive system for reading the patch test reactions. These reactions occurred mostly to oxidized surfactants and oxidation products. When retesting 9 of these 18 patients only an allergic reaction to acetaldehyde was confirmed. We conclude that oxidized ethoxylated surfactants have increased irritant potential compared to non‐oxidized material. Our working hypothesis is that oxidized surfactants of technical quality exert a lower risk of sensitization than do oxidized homologous pure surfactants. Among the potential allergens formed during autoxidation, formaldehyde and acetaldehyde must be considered as a source of unexpected exposure.
Human scalp irritation compared to that of the arm and back
Authors: Zhai Hongbo , Fautz Rolf , Fuchs Anne , Bhandarkar Sulochana , Maibach Howard I.
Published: October 2004

Large‐scale data comparing reactions to surfactants between scalp and back and arm are lacking. The sensitivity of responses between scalp and back and arm were explored utilizing an open‐application model for testing the potential irritancy of sodium lauryl sulphate (SLS). 10 bald male Caucasians (mean age 56 ± 9 years) were enrolled. We conducted 5 successive washings: for each wash, the technician pipetted 1 ml of 20% SLS solution into a glass cylinder placed on the designated area with hand pressure that prevented the cylinder leaking. The test area was then rubbed with a Teflon Policeman scrubber for 1 min. Post scrubbing, the solution was absorbed dry with a plastic pipette and blotted by gently applying paper tissues. After a 5‐min rest, the procedure was repeated for 4 more times for a total of 5 times. Skin‐irritancy assessments by visual scoring and instrumental measurements were made at 30 min and 24 h thereafter and squamometry at the end of last washing. Results indicated that most param‐ eters revealed that the back was most sensitive to the SLS challenge. Thus, these data support the current standard skin‐compatibility testing procedure, employing the back for potential irritation testing of hair care products.
The vulvar epithelium differs from the skin: implications for cutaneous testing to address topical vulvar exposures
Authors: Farage Miranda , Maibach Howard I.
Published: October 2004

Vulvar tissue is more permeable than exposed skin due to differences in structure, occlusion, hydration and susceptibility to friction. The safety assessment of products that contact the vulva should account for this potentially heightened permeability. Standard clinical patch tests may not sufficiently mimic vulvar exposures. Because testing on the vulva is not routinely feasible, we are investigating new and modified cutaneous test methods to increase the degree of conservatism of the safety assessment. To this end, we have 1) developed a method to assess chemical and frictional effects by means of repeated application to the popliteal fossa (the behind‐the‐knee test); 2) modified the quantitative risk assessment for the induction of allergic contact dermatitis; and 3) proposed a modified human repeat insult patch test for assessing materials intended for vulvar contact. Modification of the traditional 4‐day, irritation patch test by using wet samples or compromized skin sites failed to enhance test sensitivity. Future studies will evaluate testing in subjects with heightened susceptibility to chemical and sensory irritation, in order to increase test sensitivity to chemical irritants. These approaches can be employed to augment the margin of safety when cutaneous test methods are applied to agents that contact the vulva.
The Effect of Concept Formulation on Concept Test Scores
Authors: Lees Gavin , Wright Malcolm
Published: October 2004

While concept testing is a mainstay of the new product development process, there is little empirical evidence on the variation in consumer responses due to alternative concept formulations, particularly for those tests undertaken early in the product development process. The present study addressed this gap in the literature by using a split sample mail survey to compare stripped, embellished, and visual concept formulations for five heterogeneous product concepts. It was found that respondents' answers to attitude and purchase intention questions showed only minor variation with different formulations of the concept test statement. It also was found that the ranking of the concepts showed no substantial changes across the different formulations. Therefore, the type of concept statement formulation may not be that important, at least for early ranking tasks performed before experiential prototypes are available. Early concept tests therefore may be carried out using stripped concept statements. This may reduce costs, allowing organizations to undertake early concept testing more frequently across a wider range of products.
Value Creation by Toolkits for User Innovation and Design: The Case of the Watch Market
Authors: Franke Nikolaus , Piller Frank
Published: October 2004

This study analyzes the value created by so‐called “toolkits for user innovation and design,” a new method of integrating customers into new product development and design. Toolkits allow customers to create their own product, which in turn is produced by the manufacturer. In the present study, questions asked were (1) if customers actually make use of the solution space offered by toolkits, and, if so, (2) how much value the self‐design actually creates. In this study, a relatively simple, design‐focused toolkit was used for a set of four experiments with a total of 717 participants, 267 of whom actually created their own watches. The heterogeneity of the resulting design solutions was calculated using the entropy concept, and willingness to pay (WTP) was measured by the contingent valuation method and Vickrey auctions. Entropy coefficients showed that self‐designed watches vary quite widely. On the other hand, significant patterns still are visible despite this high level of entropy, meaning that customer preferences are highly heterogeneous and diverse in style but not completely random. It also was found that consumers are willing to pay a considerable price premium. Their WTP for a self‐designed watch exceeds the WTP for standard watches by far, even for the best‐selling standard watches of the same technical quality. On average, a 100% value increment was found for watches designed by users with the help of the toolkit. Taken together, these findings suggest that the toolkit's ability to allow customers to customize products to suit their individual preferences creates value for them in a business‐to‐consumer (B2C) setting even when only a simple toolkit is employed. Alternative explanations, implications, and necessary future research are discussed.
PERSPECTIVE: Ranking Business Schools on the Management of Technology
Authors: Linton Jonathan D.
Published: October 2004

Current centers of active research on the management of technology and innovation (MOT) are identified through the use of a publication‐based study. This article develops a methodology for ranking centers of MOT research and in doing so identifies 120 centers of MOT research in different parts of the world. Centers of research are identified in Africa, Asia, Australia, Europe, and North America. Detailed assessment is offered for the 21 U.S.‐based schools with three or more active MOT researchers present. The nature and quality of research activity is assessed with a series of 21 metrics. These metrics consider the number of active faculty, the number of publications researchers have in the base journals during the study period, total publication history, MOT publication history, number of equivalent articles, number of pages published, frequency of citations, and a series of metrics that are a combination of two or more of these factors. The assessment identifies four groups of schools that have MOT research capabilities. Schools with substantial research capability are divided into three tiers based on their rankings in different metrics. Each of the schools ranked in the first tier placed first on at least two of the 21 metrics considered in this study. A reasonable argument can be made that any one of the schools ranking in the first tier is the strongest school in terms of MOT research capabilities. These U.S.‐based schools in alphabetical order are Georgia Tech, MIT, Rensselaer, Rutgers, and Stanford. An important point to note is that there are clear differences in research focus between the different first‐tier schools; therefore, it is quite likely that different types of students, faculties, and practitioners will find each of the first‐tier schools most attractive based on personal fit with these differences in specialization. The schools in the second and third tier have substantial MOT research capability. The fourth tier identifies 18 additional U.S.‐based schools that have some capability due to a core of two researchers. This core could be the springboard to a national ranking or a transitory state due to departure of a faculty member. Future research should consider the stability of the results over time and should explore the links among research capabilities, program structure, student output, and placement.
Ghrelin‐Induced Growth Hormone Release From Isolated Rat Anterior Pituitary Cells Depends on Intracellullar and Extracellular Ca2+ Sources
Authors: Yamazaki M. , Kobayashi H. , Tanaka T. , Kangawa K. , Inoue K. , Sakai T.
Published: October 2004

Ghrelin, a novel growth hormone (GH)‐releasing peptide, was isolated from the rat stomach as an endogenous ligand to the growth hormone secretagogues receptor. It is known that ghrelin stimulates the release of GH from the rat anterior pituitary gland, but the intracellular signal cascade in somatotrophs has not yet been clarified. In this study, using an isolated cell perifusion system, we examined whether ghrelin‐ and growth hormone‐releasing hormone (GHRH)‐induced GH secretion from rat pituitary cells depends on intra‐ and extracellular Ca2+ and voltage‐gated Ca2+ channels. For this purpose, we first measured ghrelin‐ or GHRH‐stimulated GH concentration following treatment with reduced extracellular Ca2+ and/or thapsigargin, an endoplasmic reticulum Ca2+ ATPase inhibitor. Reductions in the extracellular Ca2+ concentration to 0.25 mM and to 0 mM resulted in decreases in ghrelin‐stimulated GH secretion to 81% and 39% and decreases in GHRH‐induced GH secretion to 83% and 13%, respectively, compared to the levels in the case of 2.5 mM Ca2+ concentration, suggesting that extracellular Ca2+ is essential for both ghrelin‐ and GHRH‐induced GH secretion. Pretreatment with thapsigargin resulted in a reduction in ghrelin‐induced GH secretion to approximately 60% of the control level, but GHRH treatment had not effect on the GH secretion. Moreover, preincubation with thapsigargin and 0 mM extracellular Ca2+ concentration resulted in significant inhibition of GHRH‐ and ghrelin‐induced GH secretion. Subsequently, to determine whether ghrelin‐stimulated GH secretion was induced through voltage‐gated Ca2+ channels, we measured the ghrelin‐stimulated GH concentration following treatment with nifedipine, an L‐type Ca2+ channel inhibitor, and found that the amount of GH secretion was reduced to 44% of the control level. Furthermore, by replacement of extracellular Na2+ in the medium with N‐methyl‐d(–)‐glucamine, an impermeable molecule, GH secretion was reduced to 47%. In this study, we demonstrated that the GH‐stimulatory effect of ghrelin, unlike that of GHRH, is achieved through both intracellular and extracellular Ca2+ sources and that ghrelin‐induced extracellular Ca2+ influx involves an L‐type voltage‐gated Ca2+ channel and Na+ influx.
Timing of Thyroid Hormone Action in the Developing Brain: Clinical Observations and Experimental Findings
Authors: Zoeller R. T. , Rovet J.
Published: October 2004

The original concept of the critical period of thyroid hormone (TH) action on brain development was proposed to identify the postnatal period during which TH supplement must be provided to a child with congenital hypothyroidism to prevent mental retardation. As neuropsychological tools have become more sensitive, it has become apparent that even mild TH insufficiency in humans can produce measurable deficits in very specific neuropsychological functions, and that the specific consequences of TH deficiency depends on the precise developmental timing of the deficiency. Models of maternal hypothyroidism, hypothyroxinaemia and congential hyperthyroidism have provided these insights. If the TH deficiency occurs early in pregnancy, the offspring display problems in visual attention, visual processing (i.e. acuity and strabismus) and gross motor skills. If it occurs later in pregnancy, children are at additional risk of subnormal visual (i.e. contrast sensitivity) and visuospatial skills, as well as slower response speeds and fine motor deficits. Finally, if TH insufficiency occurs after birth, language and memory skills are most predominantly affected. Although the experimental literature lags behind clinical studies in providing a mechanistic explanation for each of these observations, recent studies confirm that the specific action of TH on brain development depends upon developmental timing, and studies informing us about molecular mechanisms of TH action are generating hypotheses concerning possible mechanisms to account for these pleiotropic actions.
Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain*
Authors: García‐Marcos L. , Quirós A. Blanco , Hernández G. García , Guillén‐Grima F. , Díaz C. González , Ureña I. Carvajal , Pena A. Arnedo , Monge R. Busquets , Suárez‐Varela M. Morales , Varela A. López‐Silvarrey , Cabanillas P. Gómez , Garrido J. Batlles
Published: October 2004

Background:  Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart.

Methods:  Repeated cross‐sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6–7 (parent‐reported) and 13–14 (self‐reported) years old in 1994–95 (phase I) and 2002–2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participation rate was over 87% (13–14 years) and 70% (6–7 years).

Results:  The prevalence of wheezing in the previous year in children aged 13–14 years was 9.0 and 9.3% for boys and 9.6 and 9.2% for girls for phases I and III, respectively. Children 6–7 years of age showed a substantial increase in wheezing in the previous year (7.0 and 10.7% for boys and 5.3 and 8.2% for girls). Other symptoms and severity indexes followed the same patterns.

Conclusions:  In the last 8 years, the prevalence of asthma has not changed in 13–14‐year‐old Spanish children but has increased substantially in 6–7‐year olds.
Increased allergen concentration enhances IFN‐γ production by allergic donor T cells expressing a peripheral tissue trafficking phenotype
Authors: Gardner L. M. , Spyroglou L. , O'Hehir R. E. , Rolland J. M.
Published: October 2004

Background:  Clinically effective allergen‐specific immunotherapy correlates with decreased circulating allergen‐specific IL‐4+ T cells but increased IFN‐γ+ cells at sites of allergen challenge. Whether immunotherapy promotes trafficking of IFN‐γ+ T cells to peripheral tissues is unknown. As aeroallergen is administered at higher concentrations during immunotherapy than those encountered naturally, the effect of allergen concentration on adhesion molecule (CD62L and CD49d) and chemokine receptor (CCR3 and CCR5) expression by peripheral‐blood T cells was analysed in parallel with cytokine production.

Methods:  House dust mite‐allergic donor peripheral blood mononuclear cells were cultured for 14 days with different allergen concentrations. Cytokine profiles of were analysed by flow cytometry.

Results:  Cultures stimulated with 100 μg/ml house dust mite extract compared with 1 μg/ml had increased proportions and numbers of CD62Llo, CD49dhi or CCR5+ T cells expressing IFN‐γ. CCR3‐positive CD4+ and CD8+ T cell numbers were very low and did not differ between cultures. In contrast the proportions of ‘peripheral tissue trafficking’ CD4+ T cells expressing IL‐4 were decreased in cultures stimulated with high in comparison with low allergen concentration.

Conclusion:  These results indicate the importance of achieving high allergen doses during immunotherapy to promote IFN‐γ production and expression of a ‘peripheral tissue trafficking’ phenotype by allergen‐specific CD4+ and CD8+ T cells. The net change in cytokine milieu at sites of allergen encounter would then down‐regulate clinical manifestations of allergic disease.
Information provision for allergic consumers – where are we going with food allergen labelling?
Authors: Mills E. N. C. , Valovirta E. , Madsen C. , Taylor S. L. , Vieths S. , Anklam E. , Baumgartner S. , Koch P. , Crevel R. W. R. , Frewer L.
Published: October 2004

As the current treatment for food allergy involves dietary exclusion of the problem food, information for food‐allergic consumers provided on food labels about the nature of allergenic ingredients is important to the management of their condition. The members of an EU‐funded networking project, InformAll, focusing on developing strategies for the provision of credible, reliable sources of information for food allergy sufferers, regulators and the food industry, have been considering these matters with respect to food labelling. This paper presents an overview of the genesis of the new EU directive on food labelling, its relevance to food‐allergic consumers and the problems that might arise if precautionary labelling becomes more widespread in response to concerns regarding inadvertent allergen contamination in foods. International efforts to define threshold levels of allergens able to trigger a reaction coupled with validated allergen detection methods are essential if the food industry is to implement effective hazard control procedures and address the problems of cross‐contact allergens without devaluing the information provided to consumers on food labels.
Geochemistry and Rb–Sr geochronology of the alkaline–peralkaline Narraburra Complex, central southern New South Wales; tectonic significance of Late Devonian granitic magmatism in the Lachlan Fold Belt
Authors: WORMALD R. J. , PRICE R. C. , KEMP A. I. S.
Published: October 2004

Three suites of alkaline granite can be recognised in the Narraburra Complex at the triple junction of the Tumut, Giralambone–Goonumbla and Wagga Zones, central southern New South Wales. On the basis of K2O/Na2O ratios, biotite and hornblende–biotite potassic I‐type granites have been assigned to the Gilmore Hill (K2O/Na2O 1.00) and Barmedman Suites (K2O/Na2O > 1.2). These are metaluminous to weakly peraluminous suites that crystallised from high‐temperature, reduced magmas with the least fractionated members of each suite having high Ba and low Rb abundances compared to other Lachlan Fold Belt granites. Fractionated members of these suites have high abundances of high‐field‐strength elements, similar to those observed in A‐type granites. Arfvedsonite and aegirine–arfvedsonite granites have been assigned to the peralkaline Narraburra Suite. Granites from this suite have chemistry consistent with them being the intrusive equivalents of comendites and they are also similar in some respects to A‐type granites: they have, for example, particularly high abundances of Zr. The A‐type signature is, however, at least in part the result of strong fractionation. Total‐rock Rb–Sr isotopic analyses from both I‐type suites plot on the same isochron, giving an age of 365 ± 4 Ma (SrI = 0.70388 ± 53). A total‐rock isochron for the peralkaline Narraburra Suite gives a less well‐defined age of 358 ± 9 Ma (SrI = 0.7013 ± 80). The Late Devonian Rb–Sr ages may be emplacement ages or a result of resetting during fluid–rock interaction. Although granites of the Narraburra Complex have geochemical affinities with alkaline granites formed late in orogenic cycles, they post‐date arc magmatism by at least 75 million years and they formed in a within‐plate setting. Magmatism was related to localised reactivation of major faults (Gilmore Fault and the Parkes Thrust) in the region, and to partial melting involving both enriched mantle and Ordovician shoshonitic crustal components. Emplacement of the Narraburra Complex was contemporaneous with magmatism in the Central Victorian Magmatic Province and A‐type magmatism in eastern New South Wales. Collectively, all these magmatic events were related to extension post‐dating amalgamation of the western and central/eastern subprovinces of the Lachlan Fold Belt.
Nature and extent of Pliocene strandlines in southwestern Victoria and their application to Late Neogene tectonics
Authors: PAINE M. D. , BENNETTS D. A. , WEBB J. A. , MORAND V. J.
Published: October 2004

Curvilinear Th/U anomalies evident on radiometric imagery over southwestern Victoria were plotted on topographic maps and the corresponding exposures investigated in the field. These exposures were found to be dominated by quartz‐rich ferruginous duricrusts, which, based upon detailed profile descriptions and petrographic studies, are interpreted as marginal‐marine sediments of the Dorodong Sands and Loxton–Parilla Sands. Similarly oriented linear magnetic anomalies evident on aeromagnetic imagery for the Branxholme area are coincident with concentrations of detrital ferruginous magnetic gravels. These are interpreted as having been derived from weathering profiles developed in the Dorodong Sands and may have subsequently been concentrated in swales between Dorodong Sands ridges. Thus the curvilinear Th/U anomalies and magnetic anomalies are both spatially and genetically related to prior shorelines or strandlines. Some of the strandlines are covered by 4 Ma basalts, and were deposited between 6.6 and 4 Ma, i.e. very Late Miocene to Early Pliocene. Elsewhere the strandlines have a more extended time range, with the youngest strandline allocated a ca 3.5 Ma age. Strandlines at Branxholme are also younger and are regarded as Mid‐Pliocene in age. The extent of the older shorelines suggests that the major Late Miocene – Pliocene marine transgression into the Murray Basin also covered most of southwestern Victoria, much further inland than previously recognised. The variable orientation of the oldest strandlines appears to reflect a phase of syndepositional uplift of the Dundas Tablelands, causing changes in the configuration of the regressing Pliocene shoreline. The strandlines can be used as a datum for Neogene tectonism, and indicate fault displacements of up to 180 m and total uplift of up to 300 m, although faulting in the north was less intense. Most tectonism was relatively short‐lived and probably occurred between 6 and 4 Ma, i.e. Early Pliocene; the 4 Ma basalts overlying the strandlines show no evidence of faulting. Earlier faulting in the Late Miocene initiated subsidence of the prominent Hamilton Graben (identified by subsurface mapping underneath the basalt), with further movement in the Early Pliocene during deposition of the Dorodong Sands.
Comparative evaluation of Sensititre® YeastOne vs. the NCCLS M27A protocol and E‐test for antifungal susceptibility testing of yeasts
Authors: Lombardi G. , Farina C. , Andreoni S. , Fazii P. , Faggi E. , Pini G. , Manso E. , Nanetti A. , Mazzoni A.
Published: October 2004

A recently developed microdilution method (Sensititre® YeastOne) may represent a valid alternative to the National Committee for Clinical Laboratory Standards (NCCLS) method for routine testing. The Medical Mycology Committee of the Associazione Microbiologi Clinici Italiani (AMCLI) decided to evaluate its reproducibility and reliability compared with the NCCLS M27A protocol and the E‐test. Nineteen strains each of Candida albicans and Ca. parapsilosis, isolated from systemic infections, were tested against amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole. All the participating laboratories tested the YeastOne panels, while the E‐test and the NCCLS method were performed by two laboratories each. Interlaboratory reproducibility showed a good correlation (from 95% for amphotericin B to 92.5% for flucytosine). The agreement between NCCLS and YeastOne ranged from 95 (ketoconazole and itraconazole) to 100% (amphotericin B and flucytosine), whereas the agreement between E‐test and YeastOne ranged from 72.5 (fluconazole) to 100% (amphotericin B and flucytosine). The Sensititre® YeastOne panels appear to be an excellent alternative to both the E‐test and the NCCLS protocol for antifungal susceptibility testing.
Detection of Cryptococcus neoformans var. grubii in honeybee (Apis mellifera) colonies
Authors: Ergin Ç. , Ilkit M. , Kaftanoǧlu O.
Published: October 2004

The plant flora has an important role in the ecology of Cryptococcus neoformans. It is estimated that the environmental spreading and contamination of human beings with this yeast occurs via contaminated particles of plants. Cultivation of canopy parts of plants in selective media is the most widely used isolation method of this yeast. Cryptococcus neoformans var. grubii was isolated from honeybee colonies in Eucalyptus forests but was not isolated from the places where this flora did not exist. Our results indicate that the occurrence of C. neoformans in honeybee colonies during the flowering season of Eucalyptus spp. trees can be an important bioindicator for environmental yeast presence. The screening of honeybee colonies is a practical and a rapid method for the monitoring of the C. neoformans presence in flowering plants.
Lethal otogenic Candida meningitis
Authors: Koch S. , Rudel B. , Tietz H.‐J.
Published: October 2004

A 61‐year‐old woman with clinical signs of meningitis/encephalitis was admitted to hospital in a somnolent state. Inquiries with regard to the history revealed a chronic obstructive pulmonary condition which had been treated with prednisolone for a long time. There was a raised temperature with further signs of an acute inflammatory underlying disease and internal hydrocephalus. After performing trepanation, the symptoms of raised intercerebral pressure ceased. Candida albicans could be detected microbiologically in the cerebrospinal fluid. There was no pneumonia at the time of admission. Despite instituting immediate intensive care with administration of antibiotics and antimycotics, the patient died 11 days after inpatient admission. Autopsy revealed a C. albicans mycosis originating from the right middle ear with extensive suppurative meningitis, which was the immediate cause of death. Confluent bronchopneumonia had developed in both lower lung lobes at the time of death, but did not show any signs of mycosis and had contributed indirectly to the death of the patient.
Simultaneous multiple tendon ruptures complicating a seizure in a haemodialysis patient
Authors: PALMER SUETONIA , BIRKS CHRISTOPHER , DUNBAR JOHN , WALKER ROBERT
Published: October 2004

SUMMARY:  Non‐traumatic rupture of large tendons is identified as a contributor to morbidity in patients who receive haemodialysis. The injury is likely to become more common as the duration of survival on dialysis extends. A number of predisposing factors leading to tendon injury have been identified in the literature, including secondary hyperparathyroidism, β2‐microglobulin associated amyloidosis, corticosteroid treatment and fluoroquinolone antibiotic use. This is a case report of a 31‐year‐old male who presented with simultaneous large tendon ruptures following epileptiform seizures. These occurred after 10 years of treatment for end‐stage renal failure, including haemodialysis, with progressive secondary hyperparathyroidism. A review of the literature confirms progressive hyperparathyroidism as an important risk factor for large tendon rupture in patients on haemodialysis.
Impaired nitric oxide‐ and endothelium‐derived hyperpolarizing factor‐dependent dilation of renal afferent arteriole in Dahl salt‐sensitive rats
Authors: OZAWA YURI , HAYASHI KOICHI , KANDA TAKESHI , HOMMA KOICHIRO , TAKAMATSU ICHIRO , TATEMATSU SATORU , YOSHIOKA KYOKO , KUMAGAI HIROO , WAKINO SHU , SARUTA TAKAO
Published: October 2004

Background and Aims:  We previously demonstrated that acetylcholine elicited nitric oxide‐dependent sustained and endothelium‐derived hyperpolarizing factor (EDHF)‐dependent transient dilation of afferent arterioles. The present study examined whether free radicals interacted with nitric oxide‐dependent and EDHF‐dependent vasodilator mechanisms in renal microvessels of salt‐sensitive hypertension, using the isolated perfused hydronephrotic kidney.

Methods and Results:  Following the pretreatment with indomethacin (100 µmol/L) with or without nitro‐ l‐arginine methylester (100 µmol/L), the effect of acetylcholine on noradrenaline (0.3 µmol/L)‐induced constriction was evaluated in kidneys from Dahl salt‐sensitive and salt‐resistant rats. Although acetylcholine (0.01–10 µmol/L) caused dose‐dependent and sustained vasodilation of afferent arterioles, attenuated dilation was observed in Dahl salt‐sensitive rats, compared with that in salt‐resistant rats (58 ± 4 vs 101 ± 11% reversal at 10 µmol/L acetylcholine). In the presence of nitro‐ l‐arginine methylester, acetylcholine elicited only transient dilation, with vasodilator response blunted in Dahl salt‐sensitive rats (64 ± 4 vs 100 ± 9% reversal at 10 µmol/L acetylcholine). Furthermore, chronic (8–10 weeks) treatment with tempol caused partial restoration of acetylcholine (10 µmol/L)‐induced sustained arteriolar dilation (71 ± 3% reversal), but complete reversal of transient dilation (92 ± 4% reversal). Finally, acute treatment with tempol not only improved the sustained component of the acetylcholine‐induced dilation but also restored the impaired responsiveness of transient dilation in Dahl salt‐sensitive rats.

Conclusion:  Both sustained (nitric oxide‐mediated) and transient (EDHF‐mediated) components of acetylcholine‐induced afferent arteriolar dilation were attenuated in Dahl salt‐sensitive rats, which was attributed, in part, to enhanced free radical activity. A reversal of the sustained and transient vasodilation by the acute tempol treatment suggests possible interaction between free radicals and EDHF as well as increased bioavailability of nitric oxide.