bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE pH DEPENDENT METAL INHIBITION OF NUTRIENT UPTAKE BY SCENEDESMUS QUADRICAUDA(CHLOROPHYCEAE)1,2
Authors: Peterson Hans G. , Healey F. Patrick
Published: August 2010

Cadmium and copper inhibition of nutrient uptake by the green alga Scenedesmus quadricauda is highly pH dependent in an inorganic medium; both metals are less toxic at low pH. The alga was grown in chemostats with both N and P approaching limiting levels; it was then possible to study metal toxicity to the nitrate, ammonium, and phosphate uptake systems of algae in an identical physiological state. When the logarithm of the Cd concentration causing 25% inhibition of nitrate, ammonium, and phosphate uptake was regressed against pH almost perfect linear relationships were obtained. This was also true at the 50% inhibition level, except for a smaller than predicted increase in Cd toxicity to ammonium uptake at pH 8, which may be due to the beginning of Cd precipitation at this pH. Cu2+ toxicity was linearly related to pH for ammonium and phosphate uptake and although, its toxicity for nitrate uptake also increased with pH, the increase was not perfectly linear. The toxicity of total Cu showed no linear relationship to pH. Cd2+ and Cu2+ toxicity increased by up to four orders of magnitude from pH 5 to 8. Competition between free metal and hydrogen ions for uptake sites on the cell surface is suggested as a mechanism increasing the toxicity of free metal, ions as the hydrogen ion content decreases (i.e. at higher pH).
GROWTH RATE VARIATION IN THE N:P REQUIREMENT RATIO OF PHYTOPLANKTON1
Authors: Terry Kenneth L. , Laws Edward A. , Burns Deborah J.
Published: August 2010

Theoretical considerations predict that the cell N:P ratio at transition from nitrogen limitation to phosphorus limitation of phytoplankton growth (critical ratio, Rc) varies, as a function of population growth rate. This prediction is confirmed by experimental, data from the literature along with new experimental data for the marine, prymnesiophyte Pavlova lutheri (Droop) Green. Rc passes through a maximum at intermediate growth rates for the three phytoplankton species for which data, are available, but there is significant interspecific variability in its value. There is no theoretical or experimental evidence to support the idea that the ratio of subsistence N and P cell quotas is equal to Rc over the range of growth rates, or that the subsistence quota ratio equals the ratio of the N and P cell quotas minus a storage fraction. Examination of N:P composition ratios can be used to determine which nutrient is limiting, but cannot be used to determine relative growth rates or competitive advantage between species limited by the same nutrient. Growth rates are determined by environmental conditions and by the cell quota of the limiting nutrient, without reference to the cell quota of the non‐limiting nutrient.
CYANOPHYTE AND CYANELLE DNA: A SEARCH FOR THE ORIGINS OF PLASTIDS1
Authors: Coleman Annette W.
Published: August 2010

Cyanophyte‐like prokaryotes are widely presumed to be the progenitors of eukaryote plastids. A few rare protistan species bearing cyanophyte‐like cyanelles may represent intermediate stages in the evolution of true organelles. Cyanophyte DNA disposition in the cell, so far as is known from electron microscopy, seems uniform within the group and distinctly different from the several known arrangements of DNA in plastids. Therefore a survey of representative cyanophytes and protistan cyanelles was undertaken to determine whether forms reminiscent of plastids could be found. DNA‐specific fluorochromes were utilized, along with epifluorescent microscopy, to study the DNA arrangement in situ in whole cells.

Only the endospore (baeocyte)‐forming Cyanophyta contained more than one, centrally located DNA skein per cell, and then only for the period just preceding visible baeocyte formation. Such forms might, with modification, presage the “scattered nucleoid” DNA disposition found in plastids of several groups, including Rhodophytes, Cryptophytes, Chlorophytes and higher plants. The DNA arrangement in cyanelles of two protists, Cyanophora and Glaucocystis, appear different from each other and possibly related to, respectively, the cyanophytes Gloeobacter and Synechococcus. Cyanelles of the third protist, Glaucosphaera, like the cells of the unique prokaryote Prochloron, appear to have multiple sites of DNA, somewhat similar to those of the “scattered nucleoid” line of plastid evolution. No obvious precursor of the “ring nucleoid” or other types of plastid DNA conformation was found.
OBSERVATIONS ONLOPHODINIUM POLYLOPHUM(DINOPHYCEAE)1
Authors: Carty Susan , Cox Elenor R.
Published: August 2010

Lophodinium polylophum(Daday) Lemmermann is reported from a Texas pond. Cells have distinctive longitudinal ridges, an apical carina and slit, numerous golden chloroplasts, an eyespot, and a typical dinoflagellate nucleus. The theca appears to be composed of hexagonal plates. The genus is allied toWoloszynskiaThompson, family Lophodiniaceae, but probably not to the fossilDinogymnium.
PREDICTING THE KINETICS OF DISSOLVED INORGANIC CARBON LIMITED GROWTH FROM THE SHORT‐TERM KINETICS OF PHOTOSYNTHESIS IN SYNECHOCOCCUS LEOPOLIENSIS (CYANOPHYTA)1
Authors: Turpin David H. , Miller Anthony G. , Parslow John S. , Elrifi Ivor R. , Canvin David T.
Published: August 2010

The blue‐green alga (Cyanobacterium) Synechococcus leopoliensis (Racib.) Komarek was grown in dissolved inorganic carbon [DIC]‐limited chemostats over the entire range of growth rates. At each growth rate, the kinetics of photosynthesis with respect to [DIC] and the maximal rate of photosynthesis (Pmax) were determined. The half‐saturation constant for [DIC]‐limited photosynthesis (K1/2DIC) for cells growing below 1.7 d−1 was constant (4.7 μM) whereas for growth rates between 1.7 d−1 and 2.1 d−1 (μmax) the kinetics of photosynthesis were multiphasic with an apparent K1/2DIC between 1.5–2.0 mM. Pmax increased in a linear fashion with growth rate for growth rates below 1.7 d−1. No trend in Pmax was apparent for growth rates greater than 1.7 d−1. These kinetic parameters were used to predict a growth rate versus [DIC] relationship. Results show that the Monod relationship is a physiologically valid expression of growth as a function of [DIC] provided (K1/2DIC) remains constant. The major change in (K1/2DIC) as μ approaches μmax results in the conclusion that two separate and distinct Monod equations must be used to describe growth as a function of DIC over the entire growth range. These results point to a major discontinuity in the μ vs. [DIC] curve at 1.7 d−1 which corresponds to the change from high to low affinity photosynthetic kinetics. We believe these results account for the previously described deficiencies of the Monod equation in describing [DIC]‐limited algal growth.
THE ULTRASTRUCTURE OF PYRAMIMONAS PSEUDOPARKEAE SP. NOV. (PRASINOPHYCEAE) FROM SOUTH AFRICA1
Authors: Pienaar Richard N. , Aken Mark E.
Published: August 2010

The ultrastructure of Pyramimonas pseudoparkeae sp. nov., a member of the class Prasinophyceae occurring in tidal pools along the east, south and west coast of South Africa, is described. The cell surface is covered by three distinctive body scales whilst the flagellar surfaces possess four types of scales. The structure of these scales is described. P. pseudoparkeae resembles Pyramimonas parkeae Norris and Pearson but differs in the structure of the type 2 body scale. The symmetry and ultrastructure of the cell are described with special attention given to the flagellar apparatus. Preliminary information on the life cycle of this species is presented. This new species is compared with other closely related members of the genus Pyramimonas.
SEASONAL CHANGE IN THE DISTRIBUTION OF CELL SIZE OF COCCONEIS SCUTELLUM VAR. ORNATA (BACILLARIOPHYCEAE) IN RELATION TO GROWTH AND SEXUAL REPRODUCTION1
Authors: Mizuno Makoto , Okuda Kazuo
Published: August 2010

Growth and sexual reproduction of the marine littoral diatom Cocconeis scutellum Ehrenb. var. ornata Grun. were investigated at 30 different combinations of temperature (5, 10, 14, 18, 22° C), irradiance (20, 60, 100 μE·m−2·s−1) and daylength (14:10 and 10:14 h LD cycle). Growth occurred at all combinations. The optimal growth was observed at 14–18° C, long daylength and highest‐to‐moderate irradiance, and at 18° C, short daylength and highest irradiance. Sexual reproduction on the other hand occurred between 5 and 18° C, and the optimal condition was 10–14° C and short daylength.

Annual cyclic, and sesonal changes in the distribution of cell size (valve length) were observed in a field population. These changes were characterized by an annual minimum in mean cell size in autumn, an annual maximum in winter, a slight decrease from the mean in spring–middle summer, a rapid decrease from the mean in late summer–early autumn, and appearance of bimodal distribution of cell size in winter. These changes were caused by sexual reproduction in autumn, rapid growth in late summer–early autumn and slow growth in other seasons, and poor viability of small cells near the lower end of the size range.
PRODUCTIVITY OF THE FILAMENTOUS ALGA PITHOPHORA OEDOGONIA (CHLOROPHYTA) IN SURREY LAKE, INDIANA1
Authors: O'Neal Steven W. , Lembi Carole A. , Spencer David F.
Published: August 2010

Biomass, akinete numbers, net photosynthesis, and respiration of Pithophora oedogonia were monitored over two growing seasons in shallow Surrey Lake, Indiana. Low rates of photosynthesis occurred from late fall to early spring and increased to maximum levels in late spring to summer (29–39 mgO2·g−1 dry wt·h−1). Areal biomass increased following the rise in photosynthesis and peaked in autumn (163–206g dry wt·m−2). Photosynthetic rates were directly correlated with temperature, nitrogen, and phosphorus over the entire annual cycle and during the growing season. Differences in photosynthetic activity and biomass between the two growing seasons (1980 and 1981) were apparently related to higher, early spring temperatures and higher levels of NO3‐N and PO4‐P in 1981.

Laboratory investigations of temperature and light effects on Pithophora photosynthesis and respiration indicated that these processes were severely inhibited below 15°C. The highest Pmax value occurred at 35°C (0.602 μmol O2·mg−1 chl a·min−1). Rates of dark respiration did not increase above 25°C thus contributing to a favorable balance of photosynthetic production to respiratory utilization at high temperatures. Light was most efficiently utilized at 15°C as indicated by minimum values of Ik(47 μE·m−2·s−1) and Ic (6 μE·m−2·s−1). Comparison of P. oedogonia and Cladophora glomerata indicated that the former was more tolerant of temperatures above 30°C. Pithophora's tolerance of high temperature and efficient use of low light intensity appear to be adaptive to conditions found within the dense, floating algal mats and the shallow littoral areas inhabited by this filamentous alga.
THE DEVELOPMENT AND REPRODUCTIVE MORPHOLOGY OF HALOSACCION AMERICANUM I. K. LEE (RHODOPHYTA, PALMARIALES)1
Authors: Mitman Grant G. , Phinney Harry K.
Published: August 2010

Halosaccion americanum, a member of Palmariaceae, was grown in culture from spores and the life history was critically examined by the use of scanning EM and light microscopy. A mature tetrasporangium of H. americanum produces four spores that germinate to form two male and two female gametophytes. The male gametophytes grow to maturity in approximately eight months and macroscopically resemble the tetrasporophyte. Following the first division of the tetraspore, the two‐celled female gametophyte consists of a vegetative cell and a carpogonium with trichogynes. Fertilization is accomplished by spermatia from male plants of the preceding generation, as male plants of the same season are immature. Spermatia are formed in a continuous layer over the surface of the mature male gametophytes and, when released, are entrained in long strands of mucous. Spermatia adhere to and fuse with trichogynes and, nuclear fusions presumably follow. The carposporophyte is absent; the new tetrasporophyte develops directly from the fertilized carpogonium. Growth of the sporophyte eventually obliterates the female gametophyte, and development into a mature tetrasporophyte proceeds over a period of approximately eight months. The development of H. americanum, with its extremely abbreviated female gametophyte stage and direct development of the tetrasporophyte from the zygote, indicates that this rhodophyte has the same life history as reported for other members of the Palmariales.
SHADE ADAPTED BENTHIC DIATOMS BENEATH ANTARCTIC SEA ICE1
Authors: Palmisano Anna C. , SooHoo Janice Beeler , White David C. , Smith Glen A. , Stanton Gregg R. , Burckle Lloyd H.
Published: August 2010

A dense community of shade adapted microalgae dominated by the diatom Trachyneis aspera is associated with a siliceous sponge spicule mat in McMurdo Sound, Antarctica. Diatoms at a depth of 20 to 30 m were found attached to spicule surfaces and in the interstitial water between spicules. Ambient irradiance was less than 0.6 μE · m−2· s−1 due to light attenuation by surface snow, sea ice, ice algae, and the water column. Photosynthesis‐irradiance relationships determined by the uptake of NaH14CO3 revealed that benthic diatoms beneath annual sea ice were light‐saturated at only 11 μE·m−2·s−1, putting them among the most shade adapted microalgae reported. Unlike most shade adapted microalgae, however, they were not photoinhibited even at irradiances of 300 μE·m−2·s−1. Although in situ primary production by benthic diatoms was low, it may provide a source of fixed carbon to the abundant benthic invertebrates when phytoplankton or ice algal carbon is unavailable.
SPECIES OF ANTITHAMNION (RHODOPHYCEAE, CERAMIACEAE) OCCURRING ON THE SOUTHEAST AFRICAN COAST (NATAL)1
Authors: Norris Richard E.
Published: August 2010

Three species of Antithamnion Naegeli were previously known from Natal, all reported since 1984. A more thorough collection of the flora in recent months has revealed that there are nine species in Natal, four of which are newly described. Vegetative characteristics are emphasized in this study of the taxonomy of Antithamnion, the most important being (1) size of axial cells, (2) form of whorl‐branchlets, (3) size of whorl‐branchlet basal cells, (4) size and shape of whorl‐branchlet terminal cells, (5) size and position of gland cells, (6) primary or secondary derivation of indeterminate lateral branches, and (7) the relationship of primary indeterminate branches, if present, to normal arrangement of whorl‐branchlets. Two closely related species, A. diminuatum Wollaston and A. eliseae sp. nov. have been grown in laboratory culture allowing for testing of stability and reliability of vegetative characteristics for use in taxonomic studies. Conclusions are that these criteria can be effectively used for these purposes. In addition to A. eliseae, A. nematocladellum, A. pterocladellum and A. adenocladellum also are described as new species. A tropical species previously known from the Caribbean and Red Seas, A. Iherminieri Nasr, a species previously recorded from Japan, A. secundum Itono, a species previously known from California and Japan, A hubbsii Dawson, and two species from Australia, A. diminuatum Wollaston and A. divergens (J. Agardh) J. Agardh, are also described from Natal.
PHOTOSYNTHETIC LIGHT‐HARVESTING FUNCTION OF VIOLAXANTHIN IN NANNOCHLOROPSIS SPP. (EUSTIGMATOPHYCEAE)1
Authors: Owens Thomas G. , Gallagher Jane C. , Alberte Randall S.
Published: August 2010

Whole cell absorption spectra of the Eustigmatophycean algae Nannochloropsis salina Bourrelly and Nannochloropsis sp. reveal the presence of a distinct absorption peak at 490 nm. The lack of chlorophylls b and c in these species indicates that this peak must be attributed to carotenoid absorption. In vivo fluorescence excitation spectra for chlorophyll a emission show a corresponding maximum at 490 nm. This peak is more clearly resolved than carotenoid maxima in other algal classes due to the absence of accessory chlorophylls. The carotenoid composition of the two Nannochloropsis species shows that violaxanthin and vaucheriaxanthin are the main contributors to 490 nm absorption. Violaxanthin accounts for approximately 60% of the total carotenoid in both clones. We conclude that light absorption by violaxanthin, and possibly by vaucheriaxanthin, is coupled in energy transfer to chlorophyll a and that violaxanthin is the major light‐harvesting pigment in the Eustigmatophyceae. This is the first report of the photosynthetic light‐harvesting function of this carotenoid.
COCCOLITH‐ASSOCIATED POLYSACCHARIDES FROM CELLS OF EMILIANIA HUXLEYI (HAPTOPHYCEAE)1
Authors: Barman Anton H. , de Jong Elisabeth W. , Thierry Remi , Westbroek Peter , Bosch Leendert , Gruter Marijke , Kamerling Johannes P.
Published: August 2010

Coccoliths of Emiliania huxleyi (Lohmann) Hay and Mohler, a unicellular calcifying alga, consist of calcite closely associated with an acidic, Ca2+‐binding polysaccharide. This polysaccharide is thought to play a regulatory role in coccolith synthesis by interfering with CaCO3 crystallization. Here we show that the polysaccharides from three different strains, A 92, L and 92 D, all inhibit the precipitation of CaCO3 in vitro to the same extent. The monosaccharide compositions of the A 92 and L polysaccharide are similar. The 92 D material, however, deviates from the other two: it contains significantly lower amounts of methylated sugars and ribose, and elevated levels of rhamnose and galactose. It also contains antigenic determinants not detected in the A 92 and L polysaccharides. In contrast to the latter two macromolecules the 92 D polysaccharide migrates as two bands upon polyacrylamide gel electrophoresis, possibly resulting from complexing with small amounts of protein. The coccolith polysaccharide from L cells, cultured at an elevated growth rate, also migrates as two bands. This phenomenon is due to an increase in molecular size distribution. The results suggest that certain properties of the molecule may be subject to variation without interfering with its function.
FLOW CYTOMETRIC ANALYSIS OF SPERMATOGENESIS IN THE DIATOM THALASSIOSIRA WEISSFLOGII (BACILLARIOPHYCEAE)1
Authors: Vaulot Daniel , Chisholm Sallie W.
Published: August 2010

Flow cytometry was used to detect and quantify sexual differentiation in the centric diatom Thalassiosira weissflogii (Grun.). Size (light scatter), chlorophyll, protein and DNA contents were measured for each cell throughout the process of differentiation. Male gametes were small round cells characterized by one complement of DNA and a lower protein and chlorophyll content than vegetative cells. Male gamete formation was induced by a long period of darkness (2 days) followed by a transfer to continuous light. Up to 30% of the initial cell population produced male gametes which appeared in the culture 14 h after release from darkness. Male gamete production was also detected in exponentially growing cultures in continuous light, but to a much smaller degree.
ABSENCE OF CAP MEMBRANES AS A CHARACTERISTIC OF PIT PLUGS OF SOME RED ALGAL ORDERS1
Authors: Pueschel Curt M.
Published: August 2010

The current general model of the organization of a fully developed rhodophycean pit plug includes a cap membrane associated with each end of the plug. Continuity of the plasmalemma and cap membrane results in the plug core being extracellular. However, routine ultrastructural methods have not convincingly demonstrated cap membranes in the Bangiales or the Corallinales. In this study, a variety of fixation regimes that enhance membrane contrast were used in an attempt to detect cap membranes in representatives of these two orders. Although cap membranes were readily and clearly demonstrable by these methods in a representative of an order previously known to have cap membranes, they could not be detected in members of the Bangiales or Corallinales. Should the absence of cap membranes prove to be an invariant feature of these two orders, presence or absence of cap membranes will constitute a new character for phylogenetic analysis.

It is proposed that the ancestral character state of red algal pit plugs was a homogeneous plug without caps and without cap membranes.
MASSIVE ACCUMULATION OF PHYTOENE INDUCED BY NORFLURAZON IN DUNALIELLA BARDAWIL (CHLOROPHYCEAE) PREVENTS RECOVERY FROM PHOTOINHIBITION1
Authors: Ben‐Amotz Ami , Gressel Jonathan , Avron Mordhay
Published: August 2010

The effects of nanomolar to micromolar concentrations of the herbicide norflurazon were studied in Dunaliella bardawil Ben‐Amotz et Avron, a β‐carotene‐accumulating halotolerant alga. The large amount of β‐carotene which Dunaliella bardawil can contain, around 8% of the algal dry weight, is reduced to 0.2% by treatment with 100 nm norflurazon. Simultaneously, phytoene is accumulated to a similar level of about 8%. The gradual increase in phytoene content, in response to increasing norflurazon concentrations, corresponds to the decrease in β‐carotene, with no evident change in other isoprenoid intermediates. Carotene‐rich Dunaliella bardawil is substantially resistant to high‐intensity photoinhibition. This resistance is lost in cells grown to contain low β‐carotene and in the norflurazon‐treated phytoene‐rich cells. These observations are in agreement with the hypothesis that the accumulated β‐carotene in Dunaliella bardawil protects the cells against injury by excessive irradiation.
INCOMPLETENESS OF THE COCCOSPHERE AS A POSSIBLE STIMULUS FOR COCCOLITH FORMATION INPLEUROCHRYSIS CARTERAE(PRYMNESIOPHYCEAE)1
Authors: van der Wal. Paul , de Vrind Johannes P. M. , de Vrind‐de Jong Elisabeth W. , Borman Anton H.
Published: August 2010

Pleurochrysis carteraeis a marine biflagellate that produces calcified structures called coccoliths. The coccoliths are formed inside the cells and released from the latter after formation. The light dependence of calcium incorporation in this species was studied using45Ca as a tracer. Cells exposed to a repeating cycle of 16 h of light and 8 h of darkness incorporated calcium in extracellular coccoliths at a more or less constant rate throughout a cycle. The cells divided during the dark periods with a concomitant decrease in size. Their size increased during the light periods Coccolith formation in cells incubated in continuous darkness was greatly reduced and finally ceased. These cells did not divide and did not increase in size. Removal of extracellular coccoliths prior to the calcium incorporation experiments stimulated coccolith formation both in dark‐incubated cells and in cells exposed to a repeating light‐dark cycle. Cells in the stationary phase of growth ceased producing coccoliths. Calcification could be induced in these cells by removal of the extracellular coccoliths. Based on these findings we suggest that cells ofPleurochrysis carteraetend to produce a complete cover of coccoliths and that the available cell surface is a factor controlling coccolith formation.
EFFECTS OF NITROGEN AND PHOSPHORUS AVAILABILITY ON THE EXPRESSION OF THE COCCOLITH‐VESICLE V‐ATPASE (SUBUNIT C) Of PLEUROCHRYSIS (HAPTOPHYTA)1
Authors: Corstjens Paul L. A. M. , González Elma L.
Published: August 2010

The coccolithophores Emiliania and Pleurochrysis demonstrate increased coccolith production when growth is reduced by nitrate or phosphate limitation. The function of enhanced coccolith production under these conditions and its regulation have not been resolved. Studies at the molecular level are ideally suited to determine the exact relationship between calcification and other cellular functions. In a previous study we provided evidence for the presence of a vacuolar H+‐ATPase on coccolith vesicle membranes of P. carterae. These trans‐Golgi–derived vesicles are the sites of coccolith production, with each vesicle containing one coccolith. In this study, expression of the vap gene, encoding subunit c of the vacuolar H+‐ATPase, was investigated. Our objective was to explore potential relationships between vap expression, nutrient‐dependent growth, and calcification. Specifically, we monitored vap expression relative to two genes, fcp and pcna, whose expression was previously shown to vary with growth conditions; fcp encodes a fucoxanthin chl a/c‐binding protein, and pcna encodes the proliferating cell nuclear antigen. Relative to the expression of pcna and fcp, vap expression was highest at nutrient concentrations where growth curves and chl a patterns indicated arrest of cell division. Our results indicate that the level of vap expression does not decrease when cell growth diminishes.
MITOCHONDRIAL DNA PHYLOGENY OF THE SYMBIOTIC DINOFLAGELLATES (SYMBIODINIUM, DINOPHYTA)1
Authors: Takabayashi Misaki , Santos Scott R. , Cook Clayton B.
Published: August 2010

Symbiotic dinoflagellates belonging to the genus Symbiodinium (Freudenthal) are found worldwide in association with shallow‐water tropical and subtropical marine invertebrates. Most phylogenetic studies of Symbiodinium have used nuclear rRNA (nrDNA) genes to infer relationships among members of the genus. In this report, we present the first phylogeny of Symbiodinium based on DNA sequences from a mitochondrial protein‐coding gene (cytochrome oxidase subunit I [cox1]). Two principal groups, one comprised of Symbiodinium clade A and the second encompassing Symbiodinium clades B/C/D/E/F, are strongly supported in the cox1 phylogeny. Relationships within Symbiodinium clades B/C/D/E/F, however, are less well resolved compared with phylogenies inferred from nrDNA and chloroplast large subunit (cp23S)‐rDNA genes. Statistical tests between alternative tree topologies verified, with an exception being the position of one controversial member of Symbiodinium clade D, that relationships inferred from cox1 are congruent with those inferred from nrDNA and cp23S‐rDNA. Taken together, the relationships between the major Symbiodinium clades are robust, and there appears to be no evidence of hybridization or differential introgression of nuclear and plastid genomes between clades.
A modified photogrammetric technique for assessing age‐structures of elephant populations and its use in Kidepo National Park
Authors: CROZE HARVEY
Published: August 2010

(1) A modification of an aerial photographic technique for assessing the age‐structure of African elephant populations is introduced.

(2) The method is quick, inexpensive, and provides important population dynamics information relevant to one of the most serious wildlife management problems in Africa–namely, the interaction of elephants and their habitats.

(3) The method consists of photographing elephant breeding herd groups vertically, measuring their relative lengths, and then relating the lengths to a mean breeding herd growth‐curve.

(4) An example of the application of the technique is given in an assessment of the age‐structure of two elephant populations in the Kidepo Valley National Park, Uganda.

(5) The Kidepo populations are similar in age‐structure and are in general healthy. The similarities probably represent allopatric responses to the same climatic regime.

(6) Peaks and troughs in the age‐structures are related to local rainfall, which indirectly aifects conception and mortality of young animals.

(7) There are some obvious differences between the two populations, the home‐ranges of which exhibit differences in rainfall and habitat characteristics. The differences between the populations reaffirm the sensitivity of elephant population regulating mechanisms to local variations in climate and rainfall.

(8) The relative roles of post‐mortem and observational techniques in elephant studies and the need for long‐term research are discussed.
A photographic ageing technique used on warthog
Authors: BRADLEY R.
Published: August 2010

The ratios of tusk‐length: snout‐width from a series of warthog (Phacochoerus aethiopicus) photographs were calculated and plotted against the date the photographs were taken. Regression lines, as well as the 95% confidence intervals, were calculated from the photographs and plotted. These regression lines fell into four distinct groups, representing Age Classes II through V. The average degree of error in the tusk‐length: snout‐width ratio was 3‐01 units, a figure well within the above 95% confidence intervals.
Age‐related changes in biological characteristics of human alveolar osteoblasts
Authors: Jiang S.‐Y. , Shu R. , Xie Y.‐F. , Zhang S.‐Y.
Published: August 2010

Objectives:  Age‐related changes are common in many tissues and organs. However, cell‐related causes in human alveolar bone remain unclear. This study has been carried out to explore the possibility that advancing age might change the biological characteristics of alveolar osteoblasts (AOBs) in women.

Materials and methods:  Alveolar osteoblasts from women donors (five women aged 33–38 years and five women aged 62–68 years) were cultured in vitro. The cells were serially passaged and maximal lifespan evaluated. Cell viability, ultramicrostructure and osteogenic differentiation ability were determined respectively, using MTT assay, transmission electron microscopy, alkaline phosphatase (ALP) activity assay and von Kossa staining assay. These parameters of the two groups of AOBs were evaluated.

Results:  When compared with cells from young adult donors, AOBs from elderly women exhibited lower maximal lifespan (P < 0.05). Mean rate of population doubling was lower in elderly donor cells compared to those from young adult cells (P < 0.05). Organelles from AOBs of elderly donors were much fewer than those from young donors. MTT value of elderly donor cells was significantly lower than those of young adult donors from day 2 (P < 0.05). Relative ratio of ALP activity in elderly donor cells was significantly lower than those of the young womens’ cells at 8, 12, 16 and 20 days (P < 0.05). Calcium nodules of young adult donors’ specimens were significantly more numerous and larger than those from elderly donors.

Conclusions:  Comparison of biological characteristics of AOBs from young adult women with those from elderly women in vitro revealed differences in proliferative capacity and bone formation functions, which decreased with aging. These data indicate that aging may play an important role in pathogenesis of human AOBs loss.
Fluctuations in European eel (Anguilla anguilla) recruitment resulting from environmental changes in the Sargasso Sea
Authors: BONHOMMEAU SYLVAIN , CHASSOT EMMANUEL , RIVOT ETIENNE
Published: August 2010

European eel decline is now widely observed and involves a large number of factors such as overfishing, pollution, habitat loss, dam construction, river obstruction, parasitism and environmental changes. In the present study, we analyzed the influence of environmental conditions in the Sargasso Sea and Atlantic ocean circulation on European glass eel recruitment success. Over a recent 11‐yr period, we showed a strong positive correlation between an original index of glass eel recruitment and primary production (PP) in eel spawning area. Moreover, PP was negatively correlated with temperature in the Sargasso Sea. Therefore, we used sea temperature as an inverse proxy of marine production. A close negative relationship has been found over the last four decades between long‐term fluctuations in recruitment and in sea temperature. These findings were reinforced by the detection of a regime shift in sea temperature that preceded the start of the decline in glass eel recruitment in the early 1980s. By contrast, variations in integrative indices measuring ocean circulation, i.e. latitude and strength of the Gulf Stream, did not seem to explain variations in glass eel recruitment. Our results support the hypothesis of a strong bottom‐up control of leptocephali survival and growth by PP in the Sargasso Sea on short and long time scales. We argue that sea warming in the eel spawning area since the early 1980s has modified marine production and eventually affected the survival rate of European eels at early life stages.
Outcomes in total elbow arthroplasty in patients with haemophilia at the University of California, San Francisco: a retrospective review
Authors: MARSHALL BROOKS M. , TOBASE P. , KARP S. , FRANCIS D. , FOGARTY P. F.
Published: August 2010

Summary.  Severe haemophilic arthropathy of the elbow is a significant cause of morbidity among adults with haemophilia. However, previous reports of total elbow arthroplasty (TEA) in the haemophilic population have been based on small numbers of patients with relatively short‐term follow‐up. The records of seven total elbow arthroplasties in six adult men with haemophilia at the University of California, San Francisco who underwent TEA over a period of 25 years were retrospectively reviewed. Type of haemophilia, age at time of TEA, HIV infection status, pre‐ and postoperative range‐of‐motion (ROM) scores, complications (including infections), need for subsequent surgical revision and functional outcomes were recorded. Four patients had severe factor VIII deficiency and two patients had severe factor IX deficiency. None of the patients had an inhibitor. The mean age at the time of surgery was 34 years (range, 22–46 years) and the mean follow‐up period was 118 months (range, 37–176 months). One of the six patients had TEA in both elbows. Five of the six patients were infected with HIV. There were no immediate perioperative complications. At a mean of 19.2 months postoperatively, ROM had improved in five of seven TEAs: mean flexion had increased from 110.7° (SD = 15.0) to 120.1° (SD = 14.5), whereas mean preoperative extension increased from −44.3° (SD = 21.5) to −36.9° (SD = 27.0). One patient required a revision at 30 months because of ulnar component loosening. This same patient sustained a staph epidermidis infection and ultimate removal of the prosthesis 15 years postoperatively. At a mean of 118 months postoperatively, five of six patients continued to report reduced pain and preserved functionality, with ability to perform normal daily activities. TEA resulted in favourable results in six of seven procedures. Our findings support the viability of TEA for individuals with severe haemophilic arthropathy of the elbow, especially to reduce pain and preserve or restore functionality.

Level of evidence.  Level IV.
Autofluorescent granular cells in odontogenic cysts
Authors: BROWNE R.M. , RIPPIN J.W.
Published: August 2010

Three odontogenic cysts, two of dentigerous and one of dental type, are reported in which large numbers of cells containing autoflorescent granules were present, in both the capsule and cyst lining. Histochemical and electron microscopical studies suggest that the granules are composed of lipofuscin. Examination of 30 examples each of dental cysts, dentigerous cysts and odontogenic keratocysts indicated that the prevalence of occasional cells of similar appearance was about 40%, 50% and 17% respectively. The pathogenesis of these cells is discussed.
Müllerian clear cell carcinofibroma of the uterine corpus
Authors: PETERS W.M. , WELLS M. , BRYCE F.C.
Published: August 2010

A case of homologous Müllerian clear cell carcinofibroma occurring in the uterine corpus of a 71‐year‐old woman is described. The classification, histogenesis and possible biological behaviour of this unique tumour are briefly discussed.
Electron‐immunocytochemical localization of neuron‐specific enolase in cytoplasm and on membranes of primary and metastatic cerebral tumours and on glial filaments of glioma cells
Authors: VINORES S.A. , HERMAN M.M. , RUBINSTEIN L.J.
Published: August 2010

A series of primary and metastatic human brain tumours was evaluated immunocy‐tochemically for the electron microscopic localization of neuron‐specific enolase (NSE). All contained cells which, regardless of the cell type, demonstrated an irregular distribution of NSE in their cytoplasm and on membranes. This was in contrast to the staining pattern in normal central nervous system (CNS) cells which, as previously reported (Vinores et al. 1984b), show only diffuse cytoplasmic staining usually not associated with membranes. In the tumours, the interior of nuclei and the cristae and matrices of mitochondria were consistently negative, as in normal CNS cells. Except in one low‐grade fibrillary astrocytoma, the cytoplasmic filaments in neoplastic astrocytes were often, but not invariably, stained for NSE. The fine structural localization of NSE in neoplastic cells suggests that the conversion of 2‐D‐glycerophosphate to phosphoenolpyruvate by enolase may occur on the membrane and, in the case of astrocytic tumours, on the cytoplasmic filaments as well as in the cytoplasm. When cells which contain only the non‐neuronal form of enolase (NNE) transform to neoplastic cells, they may acquire the ability to produce NSE. This presumably enables them to accommodate the increased metabolic demands of neoplasia by allowing them to elude the regulatory controls that are specific for NNE.
Apoptotic bodies and abnormally dividing epithelial cells in squamous cell carcinoma
Authors: EL‐LABBAN N.G. , OSORIO‐HERRERA E.
Published: August 2010

Apoptotic bodies were investigated ultrastructurally in 10 cases of squamous cell carcinoma taken from buccal mucosa, tongue and larynx. Epithelial cells undergoing mitosis were found to show premature formation of nuclear membranes around various aggregates of chromosomal material giving the appearance of micronuclei. These cells were also shown to exhibit changes in their cytoplasm different from those seen in normally dividing epithelial cells. The changes seen in both the nuclei and cytoplasm of these cells were similar to those observed in cells undergoing apoptosis. It is suggested from this study that some apoptotic bodies, especially those of epithelial cell origin, may result from degeneration affecting cells in abnormal mitosis.
The origin of cells in the glomerular crescent investigated by the use of monoclonal antibodies
Authors: HARRISON D.J. , MACDONALD M.K.
Published: August 2010

A study was made of the cells forming the crescents in human crescentic glomerulonephritis. The investigation was performed using a panel of antibodies with immunoperoxidase techniques in formalin fixed, paraffin embedded renal biopsy material. Some of the cells of glomerular crescents were found to contain cytokeratin intermediate filaments, as did some of the cells of the normal parietal epithelium of Bowman's capsule. Leucocytes were also found in crescents, often in the outer part, and their presence was associated with a mantle of inflammatory cells around the glomerulus. The use of paraffin embedded rather than frozen tissue allowed better histological assessment than has been possible in previous studies. The glomerular crescents appeared to be primarily epithelial in origin, with leucocytes contributing to the overall inflammatory response.
Subnuclear vacuolated mucous cells: a novel abnormality of simple mucin‐secreting cells of non‐specialized gastric mucosa and Brunner's glands
Authors: THOMPSON I.W. , DAY D.W. , WRIGHT N.A.
Published: August 2010

We report a novel abnormality affecting simple mucin‐secreting cells of the glands of pyloric gastric mucosa and of Brunner's glands. Subnuclear vacuolated mucous cells show a distinctive appearance on haematoxylin and eosin staining. They are columnar cells of similar size to simple mucin‐secreting cells, but have a central nucleus beneath which the cytoplasm has a uniform glassy eosinophilic appearance or contains a clear area. Subnuclear vacuolated mucous cells are found focally lining the lower third of pyloric gastric glands or in Brunner's glands, and may be mistaken for a form of metaplasia. Histochemically, the apical portion of the cell stains for neutral mucin, but the basal portion stains only weakly and variably for protein. Electron microscopy reveals that the basal portion consists of a large, single, membranebound vacuole, variably indented by the nucleus, and probably derived from either endoplasmic reticulum or the Golgi apparatus. The vacuole contains granular material which varies in electron density from cell to cell. The apical portion of the cell contains organelles similar to simple mucin‐secreting cells. These appearances are highly suggestive of an abnormal accumulation of non‐glycoconjugated mucus core protein. Although the cause of this is unknown, it was associated with the histological changes of chronic gastritis in 10 of our 12 cases.
Epstein‐Barr virus (EBV)‐associated undifferentiated carcinoma of the parotid gland
Authors: HUANG D. P. , NG H. K. , HO Y. H. , CHAN K. M.
Published: August 2010

A case of undifferentiated carcinoma of the salivary gland occurring in the parotid gland of a southern Chinese was reported. Tumour cells showed immunofluorescence for Epstein‐Barr virus (EBV)‐associated nuclear antigen, and DNA hybridization demonstrated the presence of EBV‐DNA in tumour tissue. The findings in this case, together with previous reports, suggest a causal relationship between EBV and salivary gland carcinoma. The relationships between EBV and undifferentiated epithelial tumours of the salivary glands, nasopharynx and thymus are also discussed.
Diphtheria with a difference—a rare corynebacterium fatality with associated apoptotic cell death
Authors: LEEK M.D. , SIVALOGANATHAN S. , DEVARAJ S.K. , ZAMIRI I. , GRIFFITHS G.D. , GREEN M.A.
Published: August 2010

A case of infection with Corynebacterium ulcerans (C. ulcerans), resulted in the sudden death of a previously healthy 73‐year‐old woman. Death from Corynebacterium diphtheriae (C. diphtheriae) infection is well‐documented. Fatalities following infection with C. ulcerans are unreported; this would appear to be the first documented death due to such infection.
The spectrum of chronic periaortitis
Authors: PARUMS D.V.
Published: August 2010

A review of the histology of 440 sections of atherosclerotic aortas and arteries showed that 85% contained advanced atherosclerotic plaques. Of these, 92% showed some degree of adventitial inflammation with subclinical chronic periaortitis in 49%. A review of 20 cases of clinical chronic periaortitis, which included 12 cases of inflammatory aneurysm and 8 cases of idiopathic retroperitoneal fibrosis, showed that there were no significant differences between them apart from an increase in aortic diameter in the former. The term chronic periaortitis is appropriate for the spectrum of subclinical and clinical forms of chronic adventitial inflammation associated with advanced atherosclerosis and medial thinning.
The value of electronmicroscopy and immunohistochemistry in the diagnosis of soft tissue sarcomas: a study of 200 cases
Authors: FISHER C.
Published: August 2010

Two hundred soft tissue sarcomas, accrued consecutively over a 4‐year period, were examined by light and electronmicroscopy and by routine immunohistochemistry. The commonest tumour type was malignant fibrous histiocytoma. Fibrosarcoma, composed only of oblasts, was diagnosed in only one case; three others, composed also of myofibroblasts, could be regarded as fibrosarcomas or myofibrosarcomas. Immunohistochemistry was of most value in the diagnosis of rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumour of Schwann cell type and epithelioid sarcoma. Electronmicroscopy was of most use for the diagnosis of malignant peripheral nerve sheath tumour of perineurial cell type and marker‐negative monophasic synovial sarcoma, and for confirming malignant fibrous histiocytoma. Fifteen of 19 marker‐negative spindle cell tumours (79%) were diagnosable by electronmicroscopy. A combination of techniques resulted in a specific diagnosis in 193 cases (96.5%). The routine use of electronmicroscopy in sarcoma diagnosis can improve accuracy of diagnosis, establish the true frequency of marker‐positivity for each ultrastructurally confirmed tumour type and minimise the number of unclassifiable cases.
Preservation of cluster 1 small cell lung cancer antigen in zinc‐formalin fixative and its application to immunohistological diagnosis
Authors: TOME Y. , HIROHASHI S. , NOGUCHI M. , SHIMOSATO Y.
Published: August 2010

Monoclonal antibodies reactive with cluster 1 small cell lung cancer antigen have been shown to be useful for the distinction of small cell from non‐small cell tumours. In previous studies the antibodies have been applied to frozen sections and cold acetone‐fixed tissues. However, one of three monoclonal antibodies that we produced, NCC‐LU‐243, reacted with some small cell lung carcinomas fixed in formalin solution and embedded in paraffin. The addition of zinc sulphate to the formalin solution at a concentration of 2% (v/w) greatly improved antigen immunoreactivity, and reactivity was retained even after prolonged fixation. Occasionally, immunoreacivity was present in a poorly differentiated adenocarcinoma with rosette‐like structures. The monoclonal antibody NCC‐LU‐243 is thus of considerable potential value in the immunohistochemical diagnosis of small cell lung cancers.
Neuronal hyperplasia in the anal canal
Authors: FENGER C. , SCHRØDER H.D.
Published: August 2010

In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six of which five showed haemorrhoids. In all cases, neuronal hyperplasia was located in the submucosa beneath squamous epithelium and extended over an area from 5 to 12 mm. Immunohistochemically, the foci of hyperplasia were found to consist of both neuronal and Schwann cell components. Staining for vasoactive intestinal peptide, neuropeptide Y and calcitonin gene related peptide, did not demonstrate any increased terminal density. It is suggested that anal neuronal hyperplasia in these cases represents an acquired lesion due to local mechanical influence.
Desmoplastic supratentorial neuroepithelial tumours of infancy
Authors: PAULUS W. , SCHLOTE W. , PERENTES E. , JACOBI G. , WARMUTH‐METZ M. , ROGGENDORF W.
Published: August 2010

The clinicopathological features of two infants with desmoplastic supratentorial neuroepithelial tumours are described. The cases were similar to the 26 cases reported previously as desmoplastic infantile ganglioglioma and superficial cerebral astrocytoma attached to dura. Neuronal differentiation was absent on routine stains, but was immunohistochemically established. We review the literature and suggest classifying this clinicopathological entity by using a general designation such as desmoplastic supratentorial neuroepithelial tumours of infancy, a term which indicates the variability in the amount and lines of differentiation.
Intranasal malignant melanoma arising in an inverted papilloma
Authors: GOULDESBROUGH D.R. , MARTIN‐HIRSCH D.P. , LANNIGAN F.
Published: August 2010

A case of intranasal malignant melanoma arising in the epithelium of an inverted papilloma is described. The use of immunohistochemistry to delineate the in situ component of the malignant tumour is illustrated and the characteristic features of malignant melanomas at this site discussed.
Hepatoid adenocarcinoma of the papilla of Vater
Authors: GARDINER G.W. , LAJOIE G. , KEITH R.
Published: August 2010

An adenocarcinoma of the papilla of Vater showing hepatoid differentiation similar to that described for hepatoid adenocarcinoma of the stomach is reported12. The tumour was a poorly differentiated adenocarcinoma with clear cells containing occasional hyaline droplets and exhibiting bile secretion. Alpha‐fetoprotein (AFP), α1‐antitrypsin (α1‐AT) and carcino‐embryonic antigen (CEA) were demonstrated by immunoperoxidase staining. This appears to be the first report of a hepatoid adenocarcinoma at this location.