bluuebunny/crossref_metadata_2025 huggingface dataset:
Coronoid‐Temporalis Pedicled Rotation Flap for Orbital Floor Reconstruction of the Total Maxillectomy Defect
Authors: Pryor Shepherd G. , Moore Eric J. , Kasperbauer Jan L. , Hayden Richard E. , Strome Scott E.
Published: October 2004

Objectives: Total maxillectomy creates a significant defect in the supporting framework of the orbit. Successful reconstruction of the deficit requires repair of the orbital floor to prevent early and late complications. This paper describes the recreation of the orbital floor using a coronoid‐temporalis sling.

Study Design: Retrospective review of two patients who underwent total maxillectomy and subsequent coronoid‐temporalis sling reconstruction of the surgical defect.

Methods: The charts of two patients who underwent coronoid‐temporalis reconstruction of the orbital floor were retrospectively reviewed. The outcomes were evaluated. The authors present a method for reconstruction of the orbital floor and discuss the advantages and disadvantages of this method.

Results: Two patients underwent successful reconstruction of the orbital floor with a coronoid‐temporalis sling procedure. Both patients display acceptable functional and cosmetic results.

Conclusion: Coronoid‐temporalis sling is a readily available and easily modified tissue for reconstruction of the orbital floor. It offers similar results to those previously described techniques in this area without need for further extensive surgery.
Image Cytometry DNA‐Analysis of Fine Needle Aspiration Cytology to Aid Cytomorphology in the Distinction of Branchial Cleft Cyst from Cystic Metastasis of Squamous Cell Carcinoma: A Prospective Study
Authors: Nordemar Sushma , Tani Edneia , Högmo Anders , Jangard Mattias , Auer Gert , Munck‐Wikland Eva
Published: October 2004

Objective: Frequently, the distinction between branchial cleft cyst and cystic metastases from squamous cell carcinoma is difficult by cytomorphology. In a prospective study, we investigated the need for, and the value of, image cytometry DNA‐analysis as a complement to cytologic evaluation of cystic lesions in the neck.

Study Design: Image cytometry DNA‐analysis was performed on the fine needle aspiration cytology smears from 50 patients, referred to our department, with a solitary cystic lesion in the lateral region of the neck.

Methods: Smears from aspirates were Giemsa stained and cytologically evaluated. Ahrens image analysis was used for DNA analysis on smears stained with Schiff reagent, and lymphocytes were used as control cells. Epithelial cells with DNA values exceeding 5c were regarded as aneuploid, indicating malignancy.

Results: Nine lesions were diagnosed as squamous cell cancer metastases cytologically. DNA analysis showed aneuploidy in all of them except one. Three of these lesions had earlier been diagnosed as branchial cleft cyst at the referring hospital. Eight lesions were cytologically inconclusive and four of them were revealed as cystic metastasis at histopathologic analysis, and DNA analysis showed aneuploidy in all but one, which could not be analyzed. Two of these lesions were also diagnosed as branchial cleft cysts at the referring hospital. All benign lesions were diploid. Nine lesions were thyroid and salivary gland lesions.

Conclusion: Image cytometry DNA‐analysis was shown to help in the distinction between benign and malignant cystic lesions. Thus, when conventional cytomorphology does not suffice, DNA‐analysis is clearly a valuable supplement.
“Convulsive” Nonepileptic Seizures Have a Characteristic Pattern of Rhythmic Artifact Distinguishing Them from Convulsive Epileptic Seizures
Authors: Vinton Anita , Carino John , Vogrin Simon , MacGregor Lachlan , Kilpatrick Christine , Matkovic Zelko , O'Brien Terence J.
Published: October 2004

Summary:  Purpose: Approximately 30% of patients admitted for video‐EEG monitoring have psychogenic nonepileptic seizures (PNES). Differentiation of “convulsive” PNES from convulsive seizures can be difficult. The EEG often displays rhythmic movement artifact that may resemble seizure activity and confound the interpretation. We sought to determine whether time–frequency mapping of the rhythmic EEG artifact during “convulsive” PNES reveals a pattern that differs from that of epileptic seizures.

Methods: EEGs from 15 consecutive patients with “convulsive” PNESs were studied with time–frequency mapping by using NEUROSCAN and compared with 15 patients with convulsive epileptic seizures. Fast Fourier transforms (FFTs) were performed to determine the dominant frequency for 1‐ to 2‐s windows every 2 s through the seizures.

Results: The dominant frequency remained stable within a narrow range for the duration of the PNES, whereas in the epileptic seizures, it evolved through a wide range. The coefficient of variation of the frequency during the seizures was considerably less for patients without epilepsy (median, 15.0%; range, 7.2–23.7% vs. median, 58.0%; range, 34.8–92.1%; p < 0.001). The median frequency did not differ significantly between groups (4.2 vs. 4.6 Hz; p = 0.290).

Conclusions: “Convulsive” PNES display a characteristic pattern on time–frequency mapping of the EEG artifact, with a stable, nonevolving frequency that is different from the evolving pattern seen during an epileptic seizure.
Survival Analysis of the Surgical Outcome of Temporal Lobe Epilepsy Due to Hippocampal Sclerosis
Authors: Paglioli Eliseu , Palmini André , Paglioli Eduardo , Da Costa Jaderson C. , Portuguez Mirna , Martinez José V. , Calcagnotto Maria E. , Hoefel João R. , Raupp Sergio , Barbosa‐Coutinho Ligia
Published: October 2004

Summary:  Purpose: Surgical results in patients with mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE/HS) are often reported in conjunction with other etiologies of TLE.

Methods: We prospectively collected surgical outcome data for 2 to 11 years for 134 consecutive patients who specifically had MTLE and unilateral HS, according to magnetic resonance imaging (MRI) and confirmed by histopathology. Sixty‐five had postoperative neuropsychological testing. Outcome was analyzed by using Engel's classification (a) through Kaplan–Meier estimated survival curves (as a function of the time to seizure recurrence), (b) as percentage of patients in each outcome class on a yearly basis, and (c) at the last updated follow‐up.

Results: Kaplan–Meier estimates of complete seizure freedom (Engel's class IA) for years 1, 2, 5, and 10 were 85%, 77%, 74%, and 66%, and of Engel's class I were 89%, 86%, 83%, and 81%. Only nine (6.7%) patients had outcome classes III or IV at any point during follow‐up. Of the patients tested, 26% of those operated on the left side and 22% of those operated on the right had postoperative decline of >1 SD in verbal or visual memory, respectively.

Conclusions: High rates of seizure freedom can be obtained and remain stable over the years in patients operated on for unilateral MTLE/HS, even in countries with limited resources.
Genetic Association Studies in Epilepsy: “The Truth Is Out There”
Authors: Tan Nigel C. K. , Mulley John C. , Berkovic Samuel F.
Published: October 2004

Summary:  Success has been achieved in identifying many mutations in rare monogenic epilepsy syndromes by using linkage analysis, but dissecting the genetic basis of common epilepsy syndromes has proven more difficult. Common epilepsies are genetically complex disorders believed to be influenced by variation in several susceptibility genes. Association studies can theoretically identify these genes, but despite more than 50 association studies in epilepsy, no consistent or convincing susceptibility genes have emerged, leading to scepticism about the association‐study approach. We review the results of existing association studies in focal epilepsies, generalized epilepsies, febrile seizures, and epilepsy pharmacogenetics. By using an illustrative example, we discuss how methodologic issues of sample size, selection of appropriate controls, population stratification, and significance thresholds can lead to bias and false‐positive associations; the importance of biologic plausibility also is emphasized. Newer methodologic refinements for association studies, such as use of two control groups, genomic control, haplotyping, and use of two independent datasets, are discussed. A summary of existing guidelines and a checklist for planning and appraising such association studies in epilepsy is presented. We remain cautiously optimistic that with methodologic refinements and multicenter collaborations with large sample sizes, association studies will ultimately be useful in dissecting the genetic basis of common epilepsy syndromes.
Memory in Patients with Drug‐responsive Mesial Temporal Lobe Epilepsy and Hippocampal Sclerosis
Authors: Özkara Çiğdem , Hanoğlu Lütfü , Keskinkiliç Cahit , Yeni Naz , Aysal Fikret , Uzan Mustafa , Özyurt Emin , Karaağaç Naci
Published: October 2004

Summary:  Purpose: Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE‐HS) is the most common of the antiepileptic drug (AED)‐resistant seizure syndromes that are remediable mostly with surgery, although a small group of patients have benign prognosis with fewer seizures. Material‐specific memory impairment is an important feature in these patients and may be related to both the structural abnormality and the frequent seizures. In this study, we investigated the relation between memory deficit and HS by taking seizure frequency into account.

Methods: The patients were evaluated according to a standard protocol and divided into two groups, considering their response to AEDs: the good‐responder group (GRg, n = 18) and the pharmacoresistant group (PRg, n = 95). They were administered a neuropsychological test battery that included verbal and nonverbal memory tests, compared with each other and with a normal control group (n = 29). The responder group was evaluated by the same battery once again (mean, 23 months; SD, 8.25; range, 14–38 months).

Results: Both GR and PR patient groups had poorer memory than the normal controls in all memory tests (p < 0.05). However, the comparison of GRg with PRg revealed that only the digit‐span test was significantly worse in PRg (p = 0.0061), and no difference was found in any other memory scores. The reevaluation of the GRg showed no significant difference between the first and second evaluation.

Conclusions: We concluded that the memory impairment in patients with MTLE‐HS was permanent and might be related to the direct effect of HS itself. Therefore patients with good response to AEDs can be used as a model for investigating the memory problems in patients with MTLE‐HS.
Topiramate Pharmacokinetics in Children with Epilepsy Aged from 6 Months to 4 Years
Authors: Mikaeloff Yann , Rey Elisabeth , Soufflet Christine , D'Athis Philippe , Echenne Bernard , Vallée Louis , Bouhours Philippe , Grinspan Augusto , Dulac Olivier , Pons Gérard , Chiron Catherine
Published: October 2004

Summary:  Purpose: To study the pharmacokinetics of topiramate (TPM) at steady state in children younger than 4 years comedicated with other antiepileptic drugs (AEDs).

Methods: Twenty‐two children aged 6 months to 4 years with pharmacoresistant partial or generalized epilepsy were enrolled in an open‐label prospective study. Children were assigned to different groups according to comedication with enzyme‐inducing AEDs (n = 8), valproic acid (VPA) (n = 6), or other AEDs not known to affect drug metabolism (neutral AEDs, n = 7). One child was receiving treatment with both enzyme‐inducing AEDs and VPA. After dose titration, blood samples were collected at steady state just before and 0.5, 1, 1.5, 2, 4, 6, 8, and 12 h after the morning dose of TPM. Pharmacokinetic parameters were determined by a noncompartmental method.

Results: TPM apparent oral clearance (CL/F) was significantly higher in children taking enzyme‐inducing AEDs (85.4 ± 34.0 ml/h/kg) than in those receiving VPA (49.6 ± 13.6 ml/h/kg) or neutral AEDs (46.5 ± 12.8 ml/h/kg). Conversely, dose‐normalized areas under the plasma TPM concentration curves (0–12 h) were significantly lower in enzyme‐induced patients than in patients receiving VPA or other AEDs.

Conclusions: Compared with children not receiving enzyme inducers, children younger than 4 years who receive concomitant enzyme‐inducing AEDs need higher doses (milligrams per kilogram) to achieve comparable plasma TPM concentrations.
PHOTOSYNTHETIC PHYSIOLOGY AND CHEMICAL COMPOSITION OF SPORES OF THE KELPS MACROCYSTIS PYRIFERA, NEREOCYSTIS LUETKEANA, LAMINARIA FARLOWII, AND PTERYGOPHORA CALIFORNICA (PHAEOPHYCEAE)1
Authors: Amsler Charles D. , Neushul Michael
Published: October 2004

Recently released spores of the kelps Macrocystis pyrifera (L.) C. Ag., Nereocystis luetkeana (Mert.) Post. and Rupr., Laminaria farlowii Setch., and Pterygophora californica Rupr. had different levels of net photosynthesis. Spore‐specific photosynthesis–irradiance relationships were similar in many respects for M. pyrifera, N. luetkeana, and L. farlowii spores. All three species had low rates of net light‐saturated photosynthesis. In contrast, spores of P. californica had higher photosynthetic potential and overall net photosynthesis than the other three species. On a cell carbon basis, however, photosynthetic rates in N. luetkeana spores were similar to those of P. californica spores and higher than those of M. pyrifera spores. Chlorophyll a content of spores varied 10‐fold among species. The rank order of significant differences in chlorophyll a content was P. californica > L. farlowii > N. luetkeana > M. pyrifera. As a result, chlorophyll‐specific measurements suggest M. pyrifera and N. luetkeana spores had much higher quantum efficiency and photosynthetic potential than either P. californica or L. farlowii spores. Maternal carbon and nitrogen investment significantly differed in spores of M. pyrifera, N. luetkeana, and P. californica with P. californica > M. pyrifera > N. luetkeana. Carbon content in spores of each of these three species increased by about 30% during 12 h of saturating irradiance. We suggest that the photosynthetic capabilities of and maternal investment in spores may be related to the spore as a unit of dispersal, to the reproductive ecology of the parental sporophytic stages, and to the growth and physiology of the germling gametophyte stages.
NON‐STEADY STATE DYNAMICS OF ALGAL POPULATION GROWTH: EXPERIMENTS WITH TWO CHLOROPHYTES1
Authors: Grover James P.
Published: October 2004

The relations among dissolved phosphorus, cell quota of phosphorus, and population growth rate were determined for two Chlorophytes, Chlorella sp. and Scenedesmus quadricauda var. longispina (Chod.) G. M. Smith, in two types of non‐steady state continuous culture. One of these types had relatively smooth transitions between growth under different degrees of phosphorus limitation. Under these conditions, two equations often applied to growth kinetics in steady state cultures were found to apply to non‐steady state growth. Monad's equation described the relation between dissolved phosphorus concentration and population growth rate, and Droop's equation described the relation between cell quota and population growth rate. The second type of culture received phosphorus only as periodic pulses, leading to sharp changes in dissolved phosphorus, cell quota, and growth rate. A simulation model based on Droop's equation described much of the observed dynamics of cell numbers and quotas in these cultures. Droop's equation could not be convincingly fitted directly to the data, however, due to its incorrect prediction of an immediate growth response to phosphorus pulses. A third relation, predicting that saturated rates of phosphorus uptake would depend on the recent nutrient history of the cells as reflected by the cell quota, was not supported.
ROLE OF THE LIGHT‐DARK CYCLE AND MEDIUM COMPOSITION ON THE PRODUCTION OF COCCOLITHS BY EMILIANIA HUXLEYI (HAPTOPHYCEAE)1
Authors: Linschooten Cornelis , van Bleijswijk Judith D. L. , van Emburg Peter R. , de Vrind Johannes P. M. , Kempers Egbert S. , Westbroek Peter , de Vrind‐de Jong Elisabeth W.
Published: October 2004

Production of coccoliths by cells of Emiliania huxleyi (Lohmann) Hay and Mohler was measured during exposure of the cells to two diel light‐dark cycles (16:8 h). During the light period about eight coccoliths per cell were formed at a constant rate of one coccolith per 2 h. Cells divided during the first half of the dark period. No coccolith production took place during the dark period. With electron microscopy we found early‐stage, coccolith‐production compartments in cells after mitosis while still in the dark. No calcification was observed in these compartments. Cells grown on enriched seawater (Eppley's medium) tended to produce enough coccoliths to cover the cell in a single layer. When these cells reached the stationary phase coccolith production stopped. Coccolith production was induced by removal of extracellular coccoliths. Cells grown on medium containing 2% of the nitrate and phosphate of Eppley's medium tended to produce coccoliths in the stationary phase. This resulted in the formation of multiple layers of coccoliths. The multiple covering was restored after decalcification of stationary cells. Formation of multiple layers of coccoliths may help the cells reach deeper, nutrient‐rich water by increasing the sinking rate of the cells.
SYSTEMATICS OF ANADYOMENE SPECIES (ANADYOMENACEAE, CHLOROPHYTA) IN THE TROPICAL WESTERN ATLANTIC1
Authors: Littler Diane S. , Littler Mark M.
Published: October 2004

Three new species of Anadyomene are described. Anadyomene lacerata has pinnately branched veins and a unique lacerated margin formed by elongated vein cells. Anadyomene linkiana consists of a perforate blade arising by polychotomous branching from a distinct stripe, and A. howei has an eperforate, delicate blade of polychotomously branched cells and a smooth margin of elongated vein cells. Distinguishing features of the five previously described species are clarified, and all eight taxa are illustrated. Observations in the field and from more than 400 herbarium specimens form the basis for a discussion of Indo‐Pacific affinities, ecological adaptations, cell division, reproduction, and ordinal status.

A phylogenetic analysis based on 17 equally weighted characters produced a cladistic gradation, indicating that Anadyomene is a monophyletic genus. The most basal species (A. saldanhae, A. linkiana, A. howei, A. menziesii) show only polychotomous branching. In contrast, the distal group (A. pavonina, A. stellata, A. rhizoidifera, A. lacerata) have pinnate interstitial cells along the veins in addition to polychotomous branching at the vein apices.
CHROOMONASAND OTHER BLUE‐GREEN CRYPTOMONADS1
Authors: Hill David R. A.
Published: October 2004

Examination of four selectedChroomonasspecies indicates significant structural diversity within the genus. The concept ofChroomonasis reviewed, and new observations are presented onC. collegionissp. nov. andC. coerulea(Geitler) Skuja. Examination of two other species,Chroomonas caudataGeitler andChroomonas daucoidesConrad et Kufferath, forms the basis for the description of two new genera,KommaandFalcomonas.The generic taxonomy is based on the nature of the furrow‐gullet system, periplast structure, and features of the plastidial complex. Certain nomenclatural treatments were required:Cyanomonas americana(Davis) Oltmanns is transferred toChroomonas, C. rosenbergiaeHuber‐Pestalozzi is relegated to synonymy withC. coerulea(Geitler) Skuja, and the descriptions of Butcher's speciesC. mesostigmaticasp. nov. andC. collegionissp. nov. are completed.
A MODEL FOR GAMETE RELEASE IN ASCOPHYLLUM NODOSUM (PHAEOPHYTA)1
Authors: Bacon Linda C. , Vadas Robert L.
Published: October 2004

The question of what controls gamete release in Ascophyllum nodosum (L.) Le Jolis was studied at six sites along the central coast of Maine. Percent release was assessed weekly along randomly marked transect lines in the mid‐intertidal zone. Six independent variables–water temperature at high tide, air temperature at low tide, nitrogen (ammonia, nitrite, and nitrate), and salinity–were measured concurrently. Stepwise multiple regression analysis on the percentage of plants having released gametes revealed that water temperature at high tide accounted for most of the among‐site variation (R2= 0.77) in the timing of release. The addition of Julian day increased the R2 to 0.82; no other variables were significant. Probit analysis, based on water temperature at high tide, generated an environmentally realistic model for predicting gamete release. The model predicts the onset, midpoint, and termination of gamete release at 6, 10, and 15°C, respectively, and the midpoint at a cumulative water temperature of 358°C. This model has value for developmental studies and, potentially, for reseeding A. nodosum populations. Probits may be useful for characterizing phenological events in other fucoids and algal species.
NUTRIENT REQUIREMENTS OF THE DINOFLAGELLATE PERIDINIUM GATUNENSE1
Authors: Lindström Kåre
Published: October 2004

Optimum nutrient conditions for growth and photosynthesis of Peridinium gatunense (Nygaard) (Peridinium cinctum fa. westii) were investigated using axenic clones in batch cultures. Selenium (Se) had previously been found to be an indispensable growth factor for P. gatunense. Optimal, suboptimal, and supraoptimal concentrations of HCO3−, N, Ca, Cl, Mg, P, K, S, Si, EDTA‐Na, Fe, Mo, Zn, Mn, Co, Se, B, Br, I, and various trace element mixtures were determined by measuring biomass development, growth rates, 14C uptake, and/or oxygen production at various concentration gradients of these elements. The general characteristics of the best formulation, medium‐L 16, relative to other media, are its high content of NaHCO3 (1 meq · L−1) and Mo (0.2 μM) but low concentrations of NO3‐N (150 μM), PO4‐P (10 μM), and Fe (0.4 μM), in addition to its content of Se. The total content of trace metals, except for Se, may be reduced to one‐fourth of that in medium‐L 16 without altering the major growth‐promoting properties of the medium. Medium‐L 16 deviated considerably from Lake Kinneret (Israel) water, being much lower in macroelements except for N and P. The pH (8.1–8.4) was in the same range, but the values of conductivity (140 μS · cm−1), alkalinity (1 meq · L−1) and NaCl (200 μM) were > 8, 2, and 30 times higher, respectively, in the lake water. Selenium deficiency may limit the growth of P. gatunense in this lake.
CARBON SKELETON SOURCES FOR AMMONIUM ASSIMILATION IN N‐SUFFICIENT AND N‐LIMITED CELLS OF CYANIDIUM CALDARIUM (RHODOPHYTA)1
Authors: Di Martina Rigano Vittoria , Vona Vincenza , Esposito Sergio , Di Martina Catello , Rigano Carmelo
Published: October 2004

The possible origin of carbon skeletons for ammonium assimilation in Cyanidium caldarium (Tilden) Geitler was investigated. N‐sufficient cells assimilated ammonium at a rate of 182 ± 18 μmol·mL packed cell volume (pcv)‐1· h‐1. Removal of CO2 or darkening almost immediately prevented ammonium assimilation. N‐limited cells in light assimilated ammonium at a rate of 493 ± 45 μmol · mL pcv‐1· h‐1 in the presence of CO2 and at a lower rate of 168 ± 17 μmol · mL pcv‐1· h‐1 in the absence of CO2. In darkness they assimilated ammonium at a rate of 293 ± 29 μmol · mL pcv‐1 h‐1 in the presence of CO2, only 60% of the assimilation rate in light. In the absence of CO2, ammonium was assimilated at a similar rate of 325 ± 14 μmol · mL pcv‐1· h‐1. Under the latter conditions, however, assimilation was inhibited after 40 min and ceased after 70 min; it resumed upon resupply of CO2.

We suggest that N‐sufficient cells of C. caldarium obtain carbon skeletons for ammonium assimilation exclusively by photosynthetic reactions. Upon N‐limitation they develop the ability, apparently through derepression or activation of regulatory enzyme system(s), to obtain a consistent quantity of additional carbon skeletons and ATP from mobilization of carbon reserves. This enables the N‐limited cell to assimilate ammonium not only in light but also in darkness, and at a higher rate than N‐sufficient cells. The fact that ammonium assimilation in light occurs at a higher rate than in darkness suggests that ammonium assimilation in light is the sum of both light and dark ammonium assimilation, which implies separate metabolic reactions for the two processes. These results suggest the existence of two distinct and differently controlled pathways in N‐limited cells, but not in N‐sufficient cells, through which carbon skeletons for ammonium assimilation originate. An important role for dark CO2 fixation in dark or light ammonium assimilation is also indicated.
SUGAR COMPOSITION OF THE CELL WALL AND THE TAXONOMY OF CHLORELLA (CHLOROPHYCEAE)1
Authors: Takeda Hiroshi
Published: October 2004

Cell walls of forty Chlorella strains covering all species of the Algal Collection of Göttingen (C. fusca var. vacuolata, C. kessleri, C. luteoviridis, C. minutissima, C. protothecoides, C. saccharophila, C. sorokiniana, C. vulgaris, and C. zofingiensis) were compared. The nine species were divided into two groups according to the major sugar in the rigid wall. The first group had a glucose‐mannose‐rigid wall and included C. fusca var. vacuolata, C. luteoviridis, C. minutissima, C. protothecoides, C. saccharophila, and C. zofingiensis. The second group, with a glucosamine‐rigid wall, included C. kessleri, C. sorokiniana, and C. vulgaris. Chlorella strains of the nine species were further classified by constituent sugars, ruthenium red stainability, and anisotropy of the cell walls.
CHEMICAL COMPOSITION OF THE CELL WALLS OF THE FRESHWATER RED ALGA LEMANEA ANNULATA (BATRACHOSPERMALES)1
Authors: Gretz Michael R. , Sommerfeld Milton R. , Athey Patrick V. , Aronson Jerome M.
Published: October 2004

Cell walls of the generic phase of the freshwater red alga Lemanea annulata Kütz were mechanically isolated and chemically characterized. Walls consisted mainly of polysaccharide with lesser quantities of associated protein and lipid. The major wall component was alkali‐soluble xylan, comprised mainly of 4‐linked β‐xylopyranosyl residues and small amounts of 3‐O‐substituted β‐xylopyranosyl residues. Hot water extracts yielded non‐sulfated polymers, with 3‐ or 3,4‐linked β‐galactosyl residues alternating with 4‐linked α‐glucuronosyl residues as the predominant structural features. This acid polysaccharide shares many characteristics of the mucilage previously described from the freshwater genus Batrachospermum. Isolated cell walls of L. annulata contained approximately 6% cellulose. Cellobiohydrolase/colloidal gold labelling of cell walls revealed β‐4‐glycan throughout the fibrillar portion of the wall. Wall protein consisted of at least 17 amino acids, of which threonine and alanine were the most abundant. Polysaccharides of the cell walls of L. annulata differ from those of marine red algae and are similar to those described for other Batrachospermales.
JUNCTIONAL PORES AND CELL WALL DEPRESSIONS OFHORMOSCILLA PRINGSHEIMII(CYANOPHYCEAE)1
Authors: Rosowski James R. , Lee Kit W.
Published: October 2004

Sassoon's isolate identified asBorzia trilocularis(but recently renamedHormoscilla pringsheimiiAnagnostidis and Komárek (1988) was studied with transmission electron microscopy because of its unusual combination of longitudinal wall features, described here in development for the first time. Junctional pores (linear rows of circumferential L‐II layer pores near crosswalls) developed into multiple, parallel series, unlike the pores in many other species, which form only single rows. In dividing cells, two single pore rows appear opposite crosswalls after crosswall initiation, but an additional parallel row is usually added to each row by completion of fission. Elongating cells reveal 3–6 parallel and uniformly spaced pore rows developing on each side of crosswall pairs; these rows may end up toward the center of the cell wall after cell elongation. Pores are 18–24 nm wide with a center‐to‐center and row‐to‐row distance of 24–36 nm and occur in an especially thick L‐II area. The second group of pit‐like pores of longitudinal cell walls are 50–135 nm‐wide depressions and have a center‐to‐center distance of 100–1000 nm. These depressions arise when the L‐II layer fails to form and appear next to a row‐pair of junctional pores soon after fission. Most depressions form single rows, but when they form several rows they may cover much of the surface of the cell. The L‐III and L‐IV wall layers line these L‐II layer cavities; the outer surface of the L‐IV layer around and within the depressions is covered with fibrous mucilage. Given their diversity, pores and depressions of longitudinal walls deserve further attention from functional and taxonomic points of view.
REFLECTIVE PROPERTIES OF THE STIGMA IN MALE GAMETES OF ECTOCARPUS SILICULOSUS (PHAEOPHYCEAE) STUDIED BY CONFOCAL LASER SCANNING MICROSCOPY1
Authors: Kreimer Georg , Kawai Hiroshi , Müller Dieter G. , Melkonian Michael
Published: October 2004

The reflection properties of the stigma in male gametes of Ectocarpus siliculosus (Dillw.) Lyngbye were investigated using confocal laser scanning microscopy in the epireflection contrast mode. The complex reflection pattern obtained after optical xy (horizontal) and xz (vertical) sectioning was consistent with stigma ultrastructure as revealed by serial thin sections. The intensity and pattern of the reflection signal varied with the orientation of the cell/stigma to the incident laser light. Maximal reflection occurred only in approximately normal orientation of the stigma to the light source. Focusing of reflected light from an elongated concave depression of the stigma on the region of the flagellar swelling was observed in xy and xz sections of living and fixed gametes. The results indicate the importance of mechanisms (focusing) other than quarter‐wave interference reflection in signal amplification by the eyespot of flagellate algae.
FRACTIONATION OF NUCLEAR, CHLOROPLAST, AND MITOCHONDRIAL DNA FROM POLYSIPHONIA BOLDII (RHODOPHYTA) USING A RAPID AND SIMPLE METHOD FOR THE SIMULTANEOUS ISOLATION OF RNA AND DNA1
Authors: Roell Marina K. , Morse Daniel E.
Published: October 2004

Extraction of nucleic acids from red algae is complicated by the presence of phycocolloids. For this reason, methods used for nucleic acid isolation from other organisms are not always amenable to use with red algal preparations; modifications in some cases lead to protocols that are time consuming and complicated, often requiring large amounts of algal tissue for starting material. Here we describe the isolation of both RNA and DNA followed by fractionation and identification of nuclear, chloroplast, and mitochondrial DNAs from a single preparation of Polysiphonia boldii Wynne and Edwards using a simple method that yielded approximately 100 μg of total RNA and 20 μg of total DNA from 1 g of frozen powdered algae. The potent protein denaturant guanidinium thiocyanate and the detergent sarkosyl were used to gently lyse the cells and organelles and immediately inhibit nuclease activity in the extract. The nucleic acids were isolated by ultracentrifugation into a dense solution of CsCl; the RNA was recovered as a pellet and the DNA as a band within the CsCl solution. Agarose gel electrophoresis of the total RNA showed discrete ribosomal RNA bands, indicating little nonspecific degradation. The nuclear, chloroplast, and mitochondrial DNAs were fractionated by density gradient ultracentrifugation in the presence of the DNA binding dye, bisbenzimide H (Hoechst 33258), which binds preferentially to DNA with a high A + T:G + C ratio, thus altering its density to a greater degree than it does that of DNA with a lower nucleotide ratio. The three fractions were identified by Southern blot analysis using heterologous gene probes specific for the different genomes. The protocol should be applicable to different types of algae. The simple nucleic acid isolation step can be performed on multiple samples simultaneously without subsequent fractionation of DNA, allowing comparison of DNA from different individuals, populations, or species.
INFLUENCE OF IRRADIANCE ON CELL VOLUME AND CARBON QUOTA FOR TEN SPECIES OF MARINE PHYTOPLANKTON1
Authors: Thompson Peter A. , Harrison Paul J. , Parslow John S.
Published: October 2004

Ten species of marine phytoplankton were grown under a range of photosynthetic photon flux densities (PFDs) and examined for variation in cell volume and carbon quota. Results suggest that in response to low PFDs phytoplankton generally reduce their cell volume and frequently reduce their carbon quota. A significant linear relationship between the log of PFD (I) and cell volume (in nine of ten species) and log I and carbon quota (four of ten species) was demonstrated.

When exposed, to a transient in light intensity, Thalassiosira pseudonana (Hustedt, clone 3H) Hasle and Heimdal underwent a rapid adaptation in cell volume and carbon quota. Cells going from low light to high light reached maximum mean cell volume within 5 h, and cells going from high light to low light reached a minimum mean cell volume within 12 h. The resulting kinetic constant (k; a measure of the rate of adaptation) was considerably larger than previously reported k values. Ditylum brightwellii (West) Grunow increased in length but did not increase in width during a transient to increased irradiance.

Nutrient limitation was shown to override PFD in determining cell volume and carbon quota for Heterosigma akashiwo Hada. Cells grown at equivalent irradiances but N‐limited, were smaller than light‐limited and nutrient‐saturated cells. Therefore, cell volume and carbon quota do not have the same relationship with PFD when factors other than PFD control growth rate.

The ecological implications of reduced cell volumes and carbon quotas with decreasing PFD include possible impacts on CO2 budgets, an influence on sinking rates, potential changes in predation rates, and surface area/cell volume benefits.
CHANGE OF UBIQUITINATED PROTEINS DURING THE CELL CYCLE IN CHLAMYDOMONAS (CHLOROPHYTA)1
Authors: Shimogawara Kousuke , Muto Shoshi
Published: October 2004

Changes in the amount of heat shock‐related ubiquitinated proteins in Chlamydomonas were investigated during the cell cycle and gamete induction. In a division‐synchronized culture induced by periodic illumination, the amount of the 28‐kDa ubiquitinated protein increased during the dark phase. This increase correlated with the increase of total DNA. Such an increase was repressed when nuclear DNA replication was inhibited with aphidicolin. These results suggest that ubiquitination to form the 28‐kDa protein is involved in nuclear DNA replication or during the cell cycle. The amount of 31‐kDa ubiquitinated protein gradually increased throughout the light phase and decreased in the dark phase. The amount of 28‐kDa ubiquitinated protein also increased during gamete induction caused by nitrogen starvation, while that of the 31‐kDa did not. These results suggest that the change of ubiquitination of 28‐kDa protein mat play a fundamental role in the cell cycle and gamete induction in Chlamydomonas.
FLAGELLAR APPARATUS OF THE BIFLAGELLATE ZOOSPORES OF THE ENIGMATIC MARINE GREEN ALGA BLASTOPHYSA RHIZOPUS1
Authors: Chappell Dorothy F. , O'Kelly Charles J. , Floyd Gary L.
Published: October 2004

The flagellar apparatus of the biflagellate zoospores from Blastophysa rhizopus Reinke has 180° rotational symmetry of the major components and counterclockwise absolute orientation. The basal bodies are connected anteriorly by a prominent striated distal fiber and posteriorly by two proximal striated bands. The C microtubules in the basal bodies terminate proximal to the transition region. Terminal caps and well‐defined proximal sheaths are absent. The four microtubular rootlets diverge at a very small angle from the basal bodies. Six to eight (usually seven) microtubules are present in the s rootlets and two microtubules in the d rootlets. Rootlet 1s is associated with the eyespot. Each d rootlet is subtended by a coarsely striated fiber. Rootlet Id also has a finely striated fiber, roughly opposite the coarsely striated fiber, associated with it. Rhizoplasts and mating structures were not observed. Ultrastructural features of B. rhizopus zoospores are essentially identical with those found in examined members of the Siphonocladales sensu lato (= Siphonocladadales/Cladophorales complex) and Dasycladales, and have relatively few features in common with motile cells of caulerpalean algae. Blastophysa rhizopus probably does not represent an intermediate between the Siphonocladadales and the Caulerpales. Its evolutionary history is different from that of other algae placed in the siphonocladalean family Chaetosiphonaceae. Whether or not Blastophysa is representative of the ancestor to the Siphonodadales and Dasycladales is unclear.
DNA ANALYSIS OF EUKARYOTIC ALGAL SPECIES1
Authors: Coleman Annette W. , Goff Lynda J.
Published: October 2004

Plastid genomes of algae resemble those of terrestrial plants in form, size, and rate of nucleotide sequence change. They are circular and range in size from 73 kilobases (kb) to over 400 kb. Their many copies per cell can compose >15% of total cell DNA. Mitochondrial genomes, like plastid genomes, are present in high copy number in preparations of total algal cell DNA. Almost all known algal mitochondrial DNA genomes are relatively small, <50 kb; in some species they are linear, whereas in others they are circular.

One of the persistent perplexities for phycologists is the question of what relationship two clones or two groups of organisms bear to each other. Several relatively simple techniques can reveal whether or not two organisms belong to the same clone. Total mitochondrial genome size can be compared directly between isolates, although identity in size does not necessarily mean identity in sequence. Restriction endonuclease digestion combined with probing permits comparison of DNA fragment patterns to see if there is identity or near identity between two samples. This methodology can be applied both to organelle genomes and to nuclear genomes.

So far, restriction endonucleases cleave plastid and mitochondrial DNA of organisms belonging to the same gene pool into nearly identical fragment patterns, whereas organisms nearly or totally incapable of interbreeding display patterns wherein ≫ 50% of restriction fragments differ in position on an agarose gel after electrophoresis. Thus, organelle genomes may be the first choice for comparing both total size and restriction endonuclease fragment patterns to obtain an indication of whether two organisms are closely related. This methodology can be applied both to organisms in which interbreeding is easy to test and to the many algae in which homothallism or lack of sexual clones has precluded standard breeding analyses. With further data on variability levels within and between fertile populations, it may be possible to state with confidence whether a sample of morphologically similar organisms shares a common gene pool, even if their breeding cannot be manipulated experimentally.
2‐KETO‐SUGAR ACIDS IN GREEN FLAGELLATES: A CHEMICAL MARKER FOR PRASINOPHYCEAN SCALES1,2
Authors: Becker Burkhard , Becker Dieter , Kamerling Johannis P. , Melkonian Michael
Published: October 2004

The chemical composition of cell walls (thecae) of three taxa of scaly green flagellates (Prasinophyceae) was investigated. The theca of Tetraselmis striata, Tetraselmis tetrathele, and Scherffelia dubia consists mainly of carbohydrate (80% of dry weight), with proteins (5%), calcium (4%), and sulfate (6%) as minor components. The principal sugars (60% of dry weight) are the 2‐keto‐sugar acids 3‐deoxy‐manno‐2‐octulosonic acid (KDO), 3‐deoxy‐manno‐5‐O‐methyl‐2‐octulosonic acid (5OMeKDO), and 3‐deoxy‐lyxo‐2‐heptulosaric acid (DHA). Arabinose, gulose, galactose, galacturonic acid, and in S. dubia, xylose and rhamnose were also found. Examination of scale preparations from Mantoniella squamata, Mesostigma viride, Pyramimonas amylifera, and Nephroselmis olivacea revealed that the 2‐keto‐sugar acids were always associated with the presence of typical prasinophycean scales on the cell surface. In contrast, 2‐keto‐sugar acids were not detected in the cell wall of Chlamydomonas reinhardtii nor in polymer preparations from the culture medium of Chlamydomonas reinhardtii, Dunaliella bioculata, Dunaliella primolecta, Asteromonas gracilis, Hafniomonas reticulate, Pedinomonas tuberculata, Monomastix sp., and Micromonas pusilla. We conclude that 2‐keto‐sugar acids are chemical markers for prasinophycean scales.
KATABLEPHARIS OVALIS, A COLORLESS FLAGELLATE WITH INTERESTING CYTOLOGICAL CHARACTERISTICS1
Authors: Lee Robert Edward , Kugrens Paul
Published: October 2004

Katablepharis ovalis Skuja, isolated from an impoundment in Colorado, has a cell covering composed of two layers over the cell body and flagella. The outer component of the cell covering contains 25‐nm‐diameter hexagonal scales arranged in rows. The inner component of the cell covering is composed of a layer of interwoven microfibrils. The inner component of the cell covering is joined to the plasma membrane by one or more attachment strips that always occur outside, and along, one of the microtubular groups of the outer array. The attachment strips resemble hemidesmosomes and are composed of rows of electron‐dense material, 12 nm apart, that protrude through the plasma membrane into the extracellular space, to attach to the inner wall. The two flagella are inserted subapically into a raised area of the cell. The flagella do not have any fibrillar or tubular hairs and are covered only by the two‐layered cell covering. The cell has an inner and outer array of microtubules, both of which are spindle‐shaped, arising at the anterior end of the cell and continuing into the posterior end of the cell. A single large Golgi apparatus occurs in the anterior cytoplasm. The nucleus is in the center of the cell. Two rows of large ejectisomes occur posterior to the area of flagellar attachment. Smaller ejectisomes occur under the plasma membrane in the posterior and medial areas of the cell. Each ejectisome is composed of a single body containing a spirally wound, tapered ribbon. On discharge, the ejectisome ribbon rolls inward, creating a tubular structure. The possible relationship between Katablepharis, the green algae, and the cryptophytes is discussed.
EFFECT OF TEMPERATURE ON GERMINATION OF RHIZOCLONIUM RIPARIUM (SIPHONOCLADALES, CHLOROPHYTA) AKINETES AND ZOOSPORES1
Authors: Hall Deborah J. , Walmsley Richard D.
Published: October 2004

The temperature requirements for germination by reproductive initials of Rhizoclonium riparium (Roth) Harv., a filamentous green alga, were investigated in laboratory culture. Akinetes and zoospores were produced by exposing aging cultures to high temperatures (40°C). Germination proceeded rapidly and followed a typical bell‐shaped response curve, with germination optima between 15 and 20°C. These findings follow the trend found in related algae, i.e. reproductive initials are produced under stressful conditions.
DISTRIBUTION OF TWO TYPES OF EMILIANIA HUXLEYI (PRYMNESIOPHYCEAE) IN THE NORTHEAST ATLANTIC REGION AS DETERMINED BY IMMUNOFLUORESCENCE AND COCCOLITH MORPHOLOGY1
Authors: van Bleijswijk Judith , van der Wal Paul , Kempers Rob , Veldhuis Marcel , Young Jeremy R. , Muyzer Gerard , de Vrind‐de Jong Elisabeth , Westbroek Peter
Published: October 2004

Culture strains of Emiliania huxleyi (Lohmann 1902) Hay et al. 1967 were placed into two groups designated E. huxleyi type A and type B on the basis of coccolith morphology and immunological properties of the coccolith polysaccharide. We studied the distribution of these types in the North Atlantic region using an indirect immunofluorescence assay with antisera directed against the coccolith polysaccharide of E. huxleyi type A and type B and epifluorescence microscopy. In field samples taken in the Northeast Atlantic Ocean, E. huxleyi type A was found exclusively. In contrast, type B was dominant in the North Sea. Scanning electron microscopy of the samples revealed the same unequal distribution of the two types as found with the immunofluorescent‐labelling assay.
A STATISTICAL CHARACTERIZATION OF GROWTH AMONG CLONES OF SYNURA PETERSENII (SYNUROPHYCEAE)1
Authors: Wee James L. , Millie David F. , Walton Sharon P.
Published: October 2004

Each of four clones from the Synura petersenii complex was grown at different pHs (5.5, 6.5, 7.5, 8.5) in batch culture experiments. Growth response curves and exponential growth rates were compared among clones and pH treatments in order to examine growth trend variation among the clonal groups. The clones were isolated from geographically distant North American localities. The clonal groups represented distinct mating types, an isolate and its subisolate, and S. petersenii‐ and S. glabra‐like scale morphologies. No consistent relationship existed between growth response curve, and culture medium pH. Additionally, the trends across time differed according to clone and pH combination. Pairwise comparisons of linear trends from transformed growth response curves indicated two distinct clonal associations. Although the clonal associations corresponded with the final cell density of the cultures, growth response curves did not correspond with mating type, the parent‐isolate and subisolate, or scale morphology. Clones with glabra‐like scales had greater growth rates than the clone with petersenii‐like scales. The conflicting results generated from growth response curve and growth rate analyses support the concept that S. petersenii and S. glabra form a highly variable, homogeneous grouping.
ACCUMULATION OF ASTAXANTHIN IN HAEMATOCOCCUS LACUSTRIS (CHLOROPHYTA)1
Authors: Lee Yuan‐Kun , Soh Chee‐Weng
Published: October 2004

In N‐limited continuous chemostat cultures of the green alga Haematococcus lacustris (Gir.) Rostaf. (UTEX 16), the steady‐state astaxanthin content of the cells was determined by the specific growth rate of the cultures. The highest, pigment content was obtained at the lowest dilution rate. The specific rate of astaxanthin accumulation was, however, a function of the photon flux density measured at the illuminated culture surface. In nongrowing Haematococcus cultures, the specific rate of astaxanthin accumulation was determined by the growth rate of the culture during growth phase. The highest possible cellular astaxanthin content of all cultures was comparable and independent of the culture parameters.
EFFECTS OF LIGHT AND GLYCEROL ON THE ORGANIZATION OF THE PHOTOSYNTHETIC APPARATUS IN THE FACULTATIVE HETEROTROPHPYRENOMONAS SALINA(CRYPTOPHYCEAE)1
Authors: Lewitus Alan J. , Caron David A. , Miller Kenneth R.
Published: October 2004

The marine cryptophytePyrenomonas salinaSantore is capable of autotrophic and heterotrophic nutrition. We studied the physiological and ultrastructural changes that accompany the shift between these nutritional modes. The addition of glycerol to batch cultures ofP. salina,grown at an irradiance limiting for photoautotrophic growth, increased its growth rate and induced specific biochemical and structural changes in its photosynthetic system. Results from extracted pigment analyses, thin‐section electron microscopy, and freeze‐fracture electron microscopy indicated that glycerol addition reduced the cell phycoerythrin content, phycoerythrin to chlorophyll a ratio, degree of thylakoid packing, number of thylakoids · cell−1, and PSII particle size. These properties were reduced to a similar extent in cells grown photoautotrophically under an irradiance saturating for growth. These results are consistent with the hypothesis that enhancement of heterotrophic potential occurs at the expense of light‐harvesting ability in glycerol‐grownP. salina.