bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical and genetic factors associated with sacroiliitis in Crohn's disease
Authors: Peeters Harald , Vander Cruyssen Bert , Mielants Herman , De Vlam Kurt , Vermeire Séverine , Louis Edouard , Rutgeerts Paul , Belaiche Jacques , De Vos Martine
Published: August 2007

Background and Aim:  Radiographic sacroiliitis (SI), often asymptomatic, is considered the most frequent extra‐intestinal manifestation (EIM) of Crohn's disease (CD). Data on the association of SI with other clinical features of CD are limited. Association of SI with CARD15 polymorphisms has recently been suggested. In a multicenter study, we investigated the association of SI in CD patients with clinical phenotypes, other EIM and CARD15 polymorphisms.

Methods:  Radiographs of the sacroiliac joints were taken in 251 CD patients from three Belgian university hospitals and scored by two blinded rheumatologists. Clinical features were obtained from medical records. Forty‐three percent of patients carried at least one CARD15 polymorphism.

Results:  Sacroiliitis, defined as the presence of at least grade 2 unilateral changes, was diagnosed in 65 of the 244 scorable radiographs (27%). Only 16 of these patients were previously diagnosed with ankylosing spondylitis (AS). HLA‐B27 positivity was observed in 53% of patients with AS and 7% of patients with radiographic SI. In univariate and multivariate analysis, associations between the presence of SI and peripheral arthritis (P = 0.005) and between AS and uveitis (P = 0.005) were found. No associations with other recorded clinical features or with CARD15 polymorphisms were observed.

Conclusion:  We confirm the high prevalence of radiographic sacroiliitis in a multicenter CD cohort. Uveitis is only associated with AS whereas all patients with SI are more prone to develop peripheral arthritis during their disease course, suggesting similar pathogenetic mechanisms in the development of these EIM. The previously reported association between SI and CARD15 polymorphisms was not confirmed.
Increased esophageal mucosal/submucosal blood flow in patients with gastroesophageal reflux disease: Normalization by treatment with a proton pump inhibitor
Authors: Mine Shinichiro , Iida Takeshi , Tabata Takahiro , Okada Yosuke , Tanaka Yoshiya
Published: August 2007

Background and Aim:  Mucosal injury caused by gastroesophageal reflux may result in changes in esophageal mucosal blood flow. Little is known about esophageal mucosal blood flow in patients with gastroesophageal reflux disease (GERD). Here we examined esophageal mucosal blood flow and the effects of treatment in patients with GERD.

Methods:  The subjects included 41 cases (21 males and 20 females, mean age 64.2 years) in whom endoscopy was warranted in patients complaining of heartburn and/or regurgitation. We also studied six normal control subjects. Patients underwent endoscopy, laser Doppler flow meter measurements, and endoscopic ultrasonography before and after treatment.

Results:  Esophageal mucosal/submucosal blood flow was increased in patients with GERD compared with the control patients. The thickness of the whole esophageal wall and that of the mucosal and submucosal layers of the esophagus correlated significantly with esophageal mucosal/submucosal blood flow. The increased esophageal mucosal/submucosal blood flow significantly decreased after 4 weeks' treatment with lansoprazole, a proton pump inhibitor.

Conclusion:  Our results indicated that the pathophysiology or underlying mechanisms of GERD includes increased esophageal mucosal/submucosal blood flow, which correlates with the thickness of the esophageal wall, but is reversible and responds to treatment with lansoprazole. This suggests that proton pump inhibitors can effectively treat GERD and promote histological normalization of the mucosa and submucosa in the lower esophagus.
Risk factors for local and distant recurrence of hepatocellular carcinomas after local ablation therapies
Authors: Nouso Kazuhiro , Matsumoto Eiji , Kobayashi Yoshiyuki , Nakamura Shin‐ichiro , Tanaka Hironori , Osawa Toshiya , Ikeda Hiroshi , Araki Yasuyuki , Sakaguchi Kohsaku , Shiratori Yasushi
Published: August 2007

Background and Aim:  Hepatocellular carcinoma (HCC) recurs frequently after local ablation therapies. Recurrence following the therapies may be of two types: local recurrence and distant recurrence. The aim of the current study is to separately elucidate the predisposing factors for each recurrence.

Methods:  Among the 2141 consecutive patients with HCC who were admitted to our institute and affiliated hospital between May 1997 and April 2004, 621 patients who had undergone local ablation therapies as the initial treatment were enrolled. Correlations between the clinical backgrounds of the patients and the type of recurrence were analyzed by the Cox proportional hazard model.

Results:  A multivariate analysis revealed that tumor size (>30 mm; risk ratio 2.80; 95% confidence interval, 1.77–4.45; P < 0.0001), tumor number (≥2; 1.74, 1.23–2.47, P = 0.002), and the serum α‐fetoprotein level (>100 ng/mL; (1.62, 1.09–2.41, P = 0.014), which were classified as “tumor factors”, were significant predisposing factors for the local recurrence of HCC. In contrast, a low platelet count (<100 000/μL; 1.34, 1.04–1.74, P = 0.03) and the presence of ascites (1.73, 1.16–2.57, P = 0.008), which were classified as “background factors”, as well as tumor size (1.83, 1.11–3.01, P = 0.02) and tumor number (2.23, 1.72–3.00, P < 0.0001) were predisposing factors for distant recurrence.

Conclusion:  The predisposing factors for local and distant recurrence of HCC differ and different precautions must be observed to prevent recurrence, depending on the HCC status and background liver functions.
Role of metallothionein in Helicobacter pylori‐positive gastric mucosa with or without early gastric cancer and the effect on its expression after eradication therapy
Authors: Mitani Toshifumi , Shirasaka Daisuke , Aoyama Nobuo , Miki Ikuya , Morita Yoshinori , Ikehara Nobunao , Matsumoto Yuko , Okuno Tatsuya , Toyoda Masanori , Miyachi Hideyuki , Yoshida Shiei , Chayahara Naoko , Hori Junko , Tamura Takao , Azuma Takeshi , Kasuga Masato
Published: August 2007

Background and Aim:  Metallothionein (MT) has a proven relationship with various kinds of cancer and reduces tissue damage. Helicobacter pylori (H. pylori) infection is associated with the alteration of gastric epithelial cell cycle events, a condition implicated in the initiation and development of gastric cancer. This study investigates the role of MT in H. pylori‐induced gastritis with or without early gastric cancer (ECG) and evaluates the effect on MT expression after eradication therapy.

Methods:  Gastric biopsy samples were immunohistochemically examined for MT expression in 36 H. pylori‐negative patients without ECG and 98 positive patients with or without ECG. Real time polymerase chain reaction was performed in 14 antral biopsy samples with or without H. pylori. The severity of gastritis was also evaluated according to the updated Sydney System. In 31 successfully eradicated patients, the above assessment was repeated for two consecutive years.

Results:  MT expression was higher in H. pylori‐negative patients than in positive patients (P < 0.01). Moreover, in the corpus it was higher in H. pylori‐positive patients without ECG compared to those with ECG (P < 0.05). The MT labeling index had a negative correlation with the severity of gastritis (P < 0.01). A positive correlation was shown between the MT labeling index and apoptosis: proliferation ratio (r = 0.41, P < 0.01). The MT labeling index in H. pylori‐positive patients was gradually recovered after eradication (P < 0.05).

Conclusion:  The decrease of MT expression cannot prevent tissue damage in H. pylori‐positive gastric mucosa and leads to more severe gastritis. This phenomenon may be attributed to gastric carcinogenesis. H. pylori eradication increases MT expression and may reduce the risk of ECG.
Visceral obesity as a risk factor for colorectal neoplasm
Authors: Oh Tae‐Hoon , Byeon Jeong‐Sik , Myung Seung‐Jae , Yang Suk‐Kyun , Choi Kwi‐Sook , Chung Jun‐Won , Kim Benjamin , Lee Don , Byun Jae Ho , Jang Se Jin , Kim Jin‐Ho
Published: August 2007

Background and Aim:  Obesity as a risk factor for colorectal neoplasm (CRN) is controversial. In the present study, we evaluated visceral obesity as a risk factor for CRN.

Methods:  We prospectively enrolled 200 consecutive, asymptomatic adults (male :  female = 133:67, mean age, 50.9 ± 8.5 years) undergoing both colonoscopy and abdominopelvic computed tomography (CT) scan for routine health evaluations. The presence or absence and the characteristics of CRN were determined during colonoscopy. The amount of visceral adipose tissue (VAT) and subcutaneous adipose tissue was measured by an abdominopelvic CT scan. Body mass index, waist circumference, and percentage of body fat were measured. Blood pressure and other blood markers for assessing the metabolic syndrome were also investigated.

Results:  Of the 200 patients, 53 (26.5%) had CRN. Old age, smoking, metabolic syndrome, and a high fasting plasma glucose level were associated with an increased risk of CRN. VAT (P < 0.01) and waist circumference (P = 0.01) were significantly higher in those with CRN. A multivariate analysis of the risks of CRN showed an odds ratio of 4.07 (95% confidence interval: 1.01–16.43, P = 0.03) for those with VAT over 136.61 cm2 relative to those with VAT under 67.23 cm2. Waist circumference, metabolic syndrome, and fasting plasma glucose levels were not independent risk factors for CRN in the multivariate analysis.

Conclusion:  Increased VAT is an independent risk factor for CRN. Further large scale studies are needed to clarify the causal relationship between VAT and CRN.
Phytoplankton below the ice cover in Lake Teletskoye, a deep oligotrophic lake in western Siberia
Authors: Mitrofanova Elena Y. , Kirillov Vladimir V. , Kotovshchikov Anton V.
Published: August 2007

The composition, biomass and pigments of the phytoplankton population below the ice cover in Lake Teletskoye were investigated in March 2006. It was found that the composition and biomass of phytoplankton below the ice remained the same throughout the year. Furthermore, the stability of the water column was more important for the development of the phytoplankton assemblage below the ice than was the water temperature and light intensity. Small flagellates and diatoms were abundant among the algae in the upper layers of the lake's water column. Lake Teletskoye is similar in its phytoplankton composition and algal distribution throughout the water column to large, deep temperate lakes and Arctic or Antarctic lakes covered temporally or perennially by ice.
Effects of anthropogenic influences on the trophic status of two water supply reservoirs in Serbia
Authors: Ostojić Aleksandar , Ćurčić Svetlana , Čomić Ljiljana , Topuzović Marina
Published: August 2007

The results of hydrobiological investigations of Grošnica and Gruža Reservoirs near the city of Kragujevac in Serbia indicated differences in their trophic status. Although considerably younger than Grošnica Reservoir, Gruža Reservoir manifests all the signs of accelerated eutrophication. Primary and secondary plankton productivity is significantly greater in Gruža Reservoir, as is macrophyte production. Accelerated eutrophication also is indicated with the results of an ecological analysis. The manifested differences can be attributed mainly to the greater human influences, as well as the unfavourable morphometric characteristics of Gruža Reservoir, compared to Grošnica Reservoir.
Effects of heavy metal contamination from anthropogenic sources on Dasarahalli tank, India
Authors: Lokeshwari H. , Chandrappa G. T.
Published: August 2007

This study examines the concentrations of various heavy metals, and their distribution in a hyper‐eutrophic urban Dasarahalli tank system, which is being polluted from industrial, domestic and sewage effluents. The concentration of iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), chromium (Cr), lead (Pb) and cadmium (Cd) in water, plant (Alternanthera philoxeroides) and sediment samples was determined. The water‐soluble (bioavailable) fractions of heavy metals correlated positively with their total concentration, exhibiting the following sequence of bioavailability: Zn > Cd > Ni > Fe > Cu > Pb > Cr. A. philoxeroides exhibited a maximum bioaccumulation factor for cadmium (3913). The mean values of all types of collected samples were correlated with the corresponding mean values in a control tank (Vasanthapura tank). The sequence of the order of the concentrations of the metals in water, plant and sediment samples exhibiting higher values than those observed in the control tank was as follows: Cr > Ni > Pb > Cu > Fe > Zn, Cd > Cr > Fe ≈ Zn ≈ Cu ≈ Pb and Pb > Cu ≈ Cr > Zn ≈ Ni > Fe, respectively. The geoaccumulation indices of the heavy metals revealed that the tank is moderately contaminated. As A. philoxeroides is extensively used for human consumption and also as cattle fodder, there is a growing health risk that these metals could find their way into the human food chain.
Comparative in vivo high‐resolution confocal microscopy of corneal epithelium, sub‐basal nerves and stromal cells in mice with and without dry eye after photorefractive keratectomy
Authors: Esquenazi Salomon , He Jiucheng , Li Na , Bazan Nicolas G , Esquenazi Isi , Bazan Haydee EP
Published: August 2007

Abstract

Background:  The present study compares, using a new‐generation high‐resolution in vivo confocal microscope, the epithelial morphology, sub‐basal nerves and stroma in two groups of mice: one exposed to normal conditions (NC) and the other to a desiccating environment (DE), following photorefractive keratectomy (PRK) with mechanical epithelial scraping.

Methods:  Twenty‐four 4‐ to 8‐week‐old female Balb/C mice were used in this study. Twenty mice underwent bilateral corneal epithelial scraping using an electric brush prior to PRK. Then, the mice were divided in two groups: 10 mice were placed in NC. The other 10 mice were exposed to a DE for 2 weeks. Four mice served as controls. Corneas were analysed in vivo using the Rostock Cornea Module of the Heidelberg retina tomograph II. For all eyes, 20 confocal microscopic images of each layer, that is, the superficial and basal corneal epithelium, Bowman's layer, anterior and posterior stroma and the endothelium, were recorded. Epithelial and stromal cell densities and sub‐basal and stromal nerves were measured and compared.

Results:  There was a higher density of superficial epithelial cells in the DE group (693 ± 148 cells/mm2 in NC group and 443 ± 128 cells/mm2 in DE group; Mann–Whitney U‐test; P = 0.05). Higher number of basal cells were observed in the DE group. Its density was 986 ± 198 cells/mm2 in NC and 1598 ± 280 cells/mm2 in DE group (Mann–Whitney U‐test; P < 0.05). Significantly higher number of reflective structures were noted within the stroma without clearly visible nuclei in the DE group compared with the NC eyes. Additionally, higher number of beads, nerve sprouts and higher tortuosity of sub‐basal nerves were observed in the DE group. No difference was observed in the endothelial cell density between the groups.

Conclusion:  Exposure of corneas to a DE after PRK with previous mechanical epithelial scraping increases epithelial turnover and is associated with a higher number of reflective structures in the stroma. Additionally increased nerve beading, nerve sprouts and tortuosity of sub‐basal nerves were observed in the DE group, possibly directed to repair the alterations observed at the epithelial level.
Immunohistochemical findings in prosthesis‐associated giant papillary conjunctivitis
Authors: Bozkurt Banu , Akyurek Nalan , Irkec Murat , Erdener Ugur , Memis Leyla
Published: August 2007

Abstract

Purpose:  To identify functional subsets of inflammatory cells and expression of cytokines in the conjunctiva of patients with ocular prosthesis‐associated giant papillary conjunctivitis (P‐GPC).

Methods:  Specific immunohistochemical staining using monoclonal antibodies was performed on biopsy specimens obtained from superior tarsal conjunctiva of 18 patients with P‐GPC. The prosthetic eyes were taken as the study group, whereas their fellow eyes were used as matched controls.

Results:  In normal conjunctiva, mast cells (MCs) were located only in the substantia propria (SP), whereas in P‐GPC eyes MCs were also notable in the epithelium in five specimens. Tryptase‐chymase‐positive MCs (MCTC) were predominant both in P‐GPC (79%) and in fellow (72%) eyes. MCTC, CD4+ lymphocyte, CD8+ lymphocyte and eosinophil numbers were higher in P‐GPC specimens compared with the fellow eyes (P = 0.005, 0.074, 0.012 and 0.025, respectively). Eosinophils were detected in 58.8% of P‐GPC specimens and 16.7% of control specimens (P = 0.053). The number of inflammatory cells expressing eotaxin and interleukin (IL)‐4 was higher in P‐GPC group (P = 0.050 and 0.048, respectively). Nine out of 17 giant papillary conjunctivitis specimens (52.9%) showed eotaxin and IL‐4 immunoreactivity, which was considerably higher than the fellow eyes (16.7%) (P = 0.064).

Conclusion:  These findings suggest that P‐GPC is an allergic disease of the eye associated with increased numbers of MC, eosinophils and lymphocytes in the conjunctiva and a remarkable expression of IL‐4 and eotaxin both by the conjunctival epithelium and by the inflammatory cells in the SP.
Ocular toxicity of fluoroquinolones
Authors: Thompson Andrew M
Published: August 2007

Abstract

The ocular toxicity of fluoroquinolones and the risks of their use in the treatment of ocular infection were reviewed. Systematic identification, selection, review and synthesis of published English‐language studies relating to fluoroquinolone use and safety in animals and humans was conducted. Although not free of complications, fluoroquinolones are generally safe when used to treat ocular infection. Ocular toxicity appears to be dose‐dependent and results from class‐effects and specific fluoroquinolone structures. Phototoxicity and neurotoxicity have been reported, and toxic effects on ocular collagen may be associated with Achilles tendinopathy. Corneal precipitation may provide an advantageous drug depot but delay healing and result in corneal perforation in approximately 10% of cases. Although human toxicity studies are limited, the current recommended dose for intracameral injection of ciprofloxacin is less than 25 μg. Intravitreal injections of ciprofloxacin 100 μg, ofloxacin 50 μg/mL, trovafloxacin 25 μg or less, moxifloxacin 160 μg/0.1 mL or less and pefloxacin 200 μg/0.1 mL are considered safe.
LIBERALIZATION OF EUROPEAN TELECOMMUNICATIONS: SECTORAL DYNAMICS AND STRUCTURAL MUTATIONS
Authors: BANCE Philippe
Published: August 2007

ABSTRACT**:  This contribution intends to draw up an assessment of structural changes in the telecommunications sector impelled by the European policy of liberalization. Deep transformations with contrasted results have occurred. A strong differentiation in offer of services and a considerable fall in cost appears. After a strong growth, however, investment sharply decreased with the financial crisis. Employment has become a variable of adjustment for companies subjected to strong risks due to the economic situation. Lastly, the assertion of the universal service of telecommunications is accompanied by an important reduction of public service missions.
THE ROLE OF THE STATE AS GUARANTOR OF PUBLIC SERVICES: TRANSACTION COST ISSUES AND EMPIRICAL EVIDENCE
Authors: OBERMANN Gabriel
Published: August 2007

ABSTRACT**:  The aim of the paper is to take a closer look from a transaction cost perspective at empirical findings on the changing role of the State as a guarantor of public services. In recent years, a number of economic and legal research efforts have been devoted to analyse under which conditions and for which public services specific organizational forms and institutional arrangements would be adequate. The empirical evidence referred to for the public services supports in principle central statements and hypotheses of transaction cost theory and leads to some important conclusions for empirical research and for policy recommendations.
Improving Federalism: Drivers of Change, Repair Options and Reform Scenarios
Authors: Wanna John
Published: August 2007

The Academy of Social Sciences in Australia (ASSA) and the Institute of Public Administration Australia (IPAA) hosted a ‘Policy Roundtable on Federalism’ on the 17–18 May 2007 at the University of Canberra. Around 50 attended the roundtable comprising politicians, Commonwealth and state public servants, and academics. The roundtable was provided with a number of background papers including the Hollander‐Patapan article and another produced by staff of the Commonwealth Grants Commission entitled ‘Trends in Commonwealth‐State Financial Relations: a Grants Commission Perspective’. The roundtable focused not only on issues and challenges but, more practically, on options and how to make federalism work better.
The Malaise of Federalism: Comparative Reflections on Commonwealth–State Relations
Authors: Fenna Alan
Published: August 2007

The High Court's decision in the ‘Work Choices’ case expanding further the scope of the Commonwealth's enumerated powers is the latest reminder of the highly centralised nature of Australian federalism. The division of powers traditionally forming the essence of a federal system has become increasingly difficult to discern and the roles and responsibilities of the two levels of government have become entangled. While for a good part of Australia's history divided jurisdiction was deplored as an obstacle to progress in government, today the decay of the system is most likely to be lamented. Discussion of options for reform presupposes an understanding of the forces that have led to the present condition. This article examines the Australian experience in a broader comparative and historical perspective and suggests that those forces are endemic and substantial.
Discursive Will Formation and the Question of Legitimacy in European Politics
Authors: Jacobsson Kerstin
Published: August 2007

This article addresses the question of legitimacy, both in a general theoretical perspective and more specifically in relation to policy making in the European Union. It is argued that Jürgen Habermas' recent theories of discursive will formation provide a useful frame work for understanding the current problems of legitimacy in European policy making. The main proposition is the central connection between communication and legitimacy, and it is argued that improving the communicative character of policy making should be a central aspect of the democratization efforts in Western Europe.
The Electoral Effect of Party Leader Approval in Norway
Authors: Midtbø Tor
Published: August 2007

This article deals with the relationship between leader approval and party support. Despite an unmistakable trend towards stronger “personalization” of politics, the relationship is seen as conditional, dependent upon the particular parties and leaders as well as the political system that surrounds them. The author tries to make explicit the daunting specification and measurement problems involved in this type of analysis. A simple version of the Granger causality test and simultaneous equation models based on Norwegian panel and cross‐sectional data identify leaders who appear uncompromising and adamant as the most successful vole getters.
Parties and Voters: What Creates the Ties?
Authors: Lane Jan‐Erik , Ersson Svante
Published: August 2007

The increasing instability in the electorate and the party system forces us to reconsider the Lipset‐Rokkan thesis about the frozen party system. In this approach, cleavages played a major role, but in Western Europe, this role has diminished significantly. The frequent shifts in voter allegiance call for a new understanding of the mechanisms that connect voters and parties. A reinterpretation of the concepts of a “frozen party system” or “cleavages” is not enough. We need a new theory about the strategic interaction between parties and a floating electorate.
A Comparative Analysis of Indigenous Rights in Fennoscandia
Authors: Sillanpää Lennard
Published: August 2007

The historic claim of the Sami to lands that they have traditionally used and occupied – an issue that has long been dormant – is emerging as a significant public issue in Finland, Sweden and Norway. This article develops a control‐consociationalism typology to analyze bow each of the three states responds to Sami claims to their historic rights. Under a control situation, the cultural identity of a minority is almost exclusively determined by the laws, regulations and administrative procedures of the state. Under a consociationalism model, there would be a continuing dialogue between a stale and a minority within an administrative framework that the minority has had a major role in developing. The typology traces more than two centuries of administrative control by the three states and examines how existing institutions deal with the Sami minority. Interviews indicate that most authorities see collective minority rights as a component of human rights and, furthermore, that the Sami constitute an indigenous minority. However, the concept of aboriginal land title divides politicians and administrators; many oppose it or maintain that it is not really necessary. Many Sami rights activists, on the other hand, see it as a fundamental issue – even one of moral justice – that ultimately must be addressed by each state.
Integration to What? Marginalization from What?: Keynote Address at 19th Nordiske Sociologkongres, 13–15 June 1997, Copenhagen: “Integration and Marginalization.”
Authors: Wallerstein Immanuel
Published: August 2007

The modern world‐system has created considerable confusion about what we can mean by integration and marginalization into our societies/states. One of the principles of most sovereign states in the last two centuries is that they are composed of “citizens.” Once there were citizens, there were non‐citizens as well. Citizenship became something very valuable, and consequently not something one was very willing to share with others. Despite the fact that citizenship is a cherished good, which gives rise to “protectionist” sentiment, migration is a constantly recurring phenomenon in the modern world, which leads to the issue of national integration.

The world revolution of 1968 put into question, for the first time since the French Revolution, the concept of citizenship. What was different about me world revolution of 1968 was that it was an expression of disillusionment in the possibilities of state‐level reformism. The post‐1968 movements added something new. They insisted that racism and sexism were not merely matters of individual prejudice and discrimination but that they took on “institutional” forms as well. What these movements seemed to be talking about was not overt juridical discrimination but the covert forms that were hidden within the concept of “citizen” The concept of citizenship is, in its essence, always simultaneously inclusionary and exclusionary. We should begin to conceive whether we can go beyond or dispense with the concept of citizen, and if so, to replace it with what?
BENTHIC ALGAL COMMUNITIES OF THE METOLIUS RIVER1,2
Authors: Sherman Barbara J. , Phinney Harry K.
Published: August 2007

Sampling of benthic algae from selected sites in the Metolius River was carried out at regular intervals between April 15, 1967 and March 9, 1968 to determine the species composition of the communities. With the exception of the sampling site at the headwaters and the site immediately downstream, the benthic community of the Metolius River is described as a Cladophora–Achnanthes–Spirogyra community, with species of these 3 genera predominating on a year‐round basis. The community described for the headwaters and the sampling site immediately downstream was composed primarily of Nitzchia palea and Cymbella cistula. Of the approximately 60 species of algae which were identified, only 9 showed a definite seasonal distribution, the remaining species being found on a year‐round basis.
STABILITY OF CHLAMYDOMONAS REINHARDI IN LIQUID NITROGEN STORAGE1
Authors: Hwang Shuh‐Wei , Hudock George A.
Published: August 2007

The procedure described is applicable to 11 mutant strains of C. reinhardi Dangeard. In general, freezing resulted in 3‐log loss of viable cells. Nevertheless, the phenotypic response of the recovered viable cells to selected media was the same as before freezing. There was no further reduction in viability after 6–17 months storage at liquid N2 temperatures.
PERIDINIUM PENARDII (LEMM.) LEMM. FO. CALIFORNICUM, FORMA NOVA1
Authors: Javornický Pavel
Published: August 2007

A new forma of Peridinium penardii (Lemm.) Lemm. (Dinophyceae) is described from Clear Lake, California, based upon the morphology of a theca. The forma californicum Javorn. is believed to be a connecting link between P. penardii and P. berolinense Lemm. A nomenclatural survey of the species, as well as a key to its formae, are given.
RESULTS OF AN ATTEMPT TO OBTAIN PYRENOIDS OF ZYGNEMA BY BULK‐ISOLATION METHODS1,2
Authors: Rosowski James R. , Hoshaw Robert W.
Published: August 2007

Filaments of Zygnema were blended 3 min in a buffered sucrose solution, and a pyrenoid‐rich cell fraction was obtained by filtration through a 10‐μ filter. The filtrate was placed on a 35%/40%/50% (wt/wt) discontinuous sucrose density gradient and was spun at approximately 50,000 × g for 1/2–1 hr. Pyrenoids, which were collected at the 40%/50% interface, appeared with light microscopy to be firm, intact, spherical, colorless refractive bodies. Although in situ pyrenoids stained with propionocarmine, isolated pyrenoids would not stain, indicating a change in the chemical properties of pyrenoids during the isolation procedure.
EFFECTS OF SOME PROTEIN AND NUCLEIC ACID SYNTHESIS INHIBITORS ON FERTILIZATION IN VOLVOX CARTERI1
Authors: Hutt William , Kochert Gary
Published: August 2007

The fertilization process in Volvox involves a series of events described as follows. A sperm bundle produced by the male colony attaches to the female colony. The bundle then dissociates to a cluster of individual sperm prior to formation of a fertilization pore in the sheath of the female colony. Sperm subsequently enter the matrix of the female colony and presumably fertilize the eggs.

The protein synthesis inhibitors cycloheximide, chloramphenicol, and puromycin each, blocked fertilization pore formation. The nucleic acid synthesis inhibitors actinomycin D and 5‐fluorouracil were also tested. Actinomycin D completely blocked fertilization pore formation, whereas 5‐fluorouracil appeared to have no effect. A proposed mechanism of fertilization pore formation is discussed.
YELLOW‐GREEN ALGAE WITH CHLOROPHYLLIDE C1,2
Authors: Guillard Robert R. L. , Lorenzen Carl J.
Published: August 2007

Chlorophyllide c (chlorophyll c) wax found in axenic or unialgal cultures of 5 members of the class Xanthophyceae and in 2 members of the class Raphidophyceae (Chloromonadophyceae).

Two other algae contained no chl c; neither had chl b. One of these plants, Pleurochloris magna, is presumably a member of the newly named class Eustigmatophyceae (Hibberd and Leedale). The other alga, clone GSB Sticho, is of uncertain, systematic position.

Although, the xanthophyll pigments were not critically studied, there is enough evidence, to permit the conclusion that the xanthophyll suites of the chloromonads, the xanthophytes, P. magna, and clone GSB Sticho all differ in at least one respect.
RETENTION OF DISSOLVED COMPOUNDS BY MEMBRANE FILTERS AS AN ERROR IN THE 14C METHOD OF PRIMARY PRODUCTION MEASUREMENT1
Authors: Nalewajko C. , Lean D. R. S.
Published: August 2007

Membrane filters retain 14C bicarbonate, 14C glycollate, and other 14C labeled substances from filtrates of algal cultures and lake water. By refiltering different volumes of the filtrate from algal cultures and from lake water after incubation with 14C bicarbonate, it was shown that the labeled material retained was not proportional to volume but showed a saturation effect with increasing volume filtered. When the radioactivity retained by a filter is divided by the volume filtered, decreasing values are obtained with increased volume filtered. This radioactivity may represent a significant addition to the radioactivity in particulate material on the filters, resulting in a similar type of curve when different volumes of lake water or cultures are filtered.

Values of radioactivity per milliliter were constant using Chlorella in Chu 10 medium. However, the curve could, be obtained by increasing pH and bicarbonate concentrations in the medium and on resuspending the algae in Lake Ontario (winter) filtrate. The values of cpm/ml retained from filtrates were low in Cryptomonas cultures and the curve was not obtained unless population density was reduced, thus increasing the relative contribution to the radioactivity on the filters.

The curve was not always obtained in lake water. It was significant in 10 out of 14 experiments in Lake Ontario and in 2 out of 5 experiments in Grenadier Pond. Changes in lake water rather than in experimental techniques were probably responsible. On 2 occasions when values of cpm/ml were constant in Lake Ontario, addition of sodium bicarbonate without a pH change resulted, in a significant curve.

Our experiments do not disprove the possibility of cell damage during Millipore filtration, however, it has been shown that 14C labeled substances retained from solutions can account for the entire range of decreasing values as a function of volume filtered.
A POSSIBLE VIRUS INFECTION IN THE GREEN ALGA OEDOGONIUM1
Authors: Pickett‐Heaps J. D.
Published: August 2007

Developing germlings of the green alga Oedogonium have been sectioned and some were found to contain particles presumed to be those of a virus. Fully formed particles were hexagonal in a 2‐dimensional section, about 240 nm in diameter with a densely stained surface layer and core; what appear to be different stages in their assembly were also seen. Many of the particles were clustered together in groups surrounded by aggregations of ribosomes. In cells containing many of the particles, the germlings' cytoplasm and organelles showed considerable evidence of disruption and breakdown. These particles have only been detected in germlings, so infection by this presumed virus was probably initiated in the naked, motile zoospore.
ORGANIC EXCRETION BY DUNALIELLA TERTIOLECTA1
Authors: Huntsman Susan A.
Published: August 2007

Excretion of C14‐labeled organic material by Dunaliella tertiolecta was observed under a variety of conditions. In healthy cultures, percent excretion tints related to cell density bill independent of light and preconditioning of the medium. Exaction was lower in nutrient‐limited culture than in an enriched medium, and in both cases was minimal during logarithmic growth. Increases in dissolved carbohydrate during stationary phase represented an accumulation of high molecular weight compounds.

The general composition of labeled excretory products was similar in both actively growing and stationary cultures. The data suggest that excretion may involve different processes at high and low cell densities.
AMINO ACID TRANSPORT IN NITZSCHIA OVALIS ARNOTT1,2
Authors: North Barbara B. , Stephens Grover C.
Published: August 2007

The marine diatom Nitzschia ovalis possesses at, least 3 amino acid uptake systems, specific for transport of acidic, polybasic, and, neutral amino acids. Maximum uptake velocity (Vmax) for each, site is inversely related to the nitrogen content of the cell, and to the nitrogen available in the culture medium. Transport, of polybasic amino acids occurs throughout the course of growth in batch, culture, but the Vmax increases dramatically as the culture ages and nitrogen/cell reaches a low value. Ks does not, change significantly. Acidic and neutral amino acids are taken up only by cells harvested from nitrogen‐poor culture. It appears that amino acid transport is repressed by high concentrations of nitrogen in the medium. Under natural conditions, where nitrogen concentrations are low, the contribution of amino acid uptake to the nitrogen economy of Nitzschia populations may be significant.
RADIOISOTOPIC STUDY OF CALCIFICATION IN THE ARTICULATED CORALLINE ALCA BOSSIELLA ORBIGNIANA1
Authors: Pearse Vicki Buchsbawn
Published: August 2007

Calcification in Bossiella orbigniana (Corallinaceae) is characterized by a series of features which, vary according to the age of the segment (intergeniculum). From the youngest segment at the branch tip to older, more basal segments: (1) weight and degree of mineralization increase, while rate of weight gain decreases; (2) rate and stability of calcium‐45 labeling decrease; (3) effect of light on calcium‐45 labeling rate decreases, while effect of light on stability of label increases; however, for all segments, calcium‐45 labeling is more rapid and more stable in the light than in the dark; (4) rate of calcium‐45 labeling in killed controls decreases. Comparative studies with the tropical coralline alga Amphiroa yielded similar results. Characteristics of the gradients in calcification and effect of light in these coralline algae are very similar to those found, in a reef‐building coral containing symbiotic algae, and the data suggest that organic products of photosynthesis may be of general importance to calcification.
THE PRODUCTION OF EXTRACELLULAR POLYSACCHARIDE BY THE UNICELLULAR RED ALGAPORPHYRIDIUM AERUGINEUM1,2
Authors: Ramus J.
Published: August 2007

The unicellular red algaPorphyridium aerugineumwas shown to be encapsulated by an amorphous, water‐soluble, polyanionic polysaccharide of high molecular weight. The encapsulating polysaccharide is qualitatively identical with polysaccharide found dissolved in large quantity in the culture medium. The kinetics of extracellular polysaccharide production as a function of cell age was studied. Rates of production (on a per cell basis) of both encapsulating and dissolved polysaccharides are greatest in stationary phase light‐grown cultures.

Dissolved polysaccharide was quantitatively isolated by precipitation with cetyl pyridinium chloride, conversion to the calcium salt, and reprecipitation with ethanol. The procedure yields a spectrally pure product, which is composed of glucose, galactose, xylose, and 2 undetermined, sugar components, and has a sulfate content of 7.6% by weight.

Electron microscopy ofPorphyridiumrevealed that Golgi vesicles transport, polymerized polysaccharides to and through the cell membrane. Similar vesicles were observed in the multicellularPseudogloiophloea, indicating that the Golgi complex plays a crucial role in the production of extracellular polysaccharides by the red algae.

H14CO3‐pulse‐label experiments resulted in labeled extracellular polysaccharide in which all the constituent components contained14C. Rates of excretion of polysaccharide were found, to follow a cyclic pattern, correlated generally with the division cycle, of the cell.
ERUMPENT CEPHALODIA, AN APPARENT CASE OF PHYCOBIAL INFLUENCE ON LICHEN MORPHOLOGY1,2,3
Authors: Jordan William Paul
Published: August 2007

On the upper surface of some specimens of the lichen Lobaria cf. crosa (Eschw.) Nyl. there are shrub‐like growths which have a morphology similar to that of a free‐living fruticose lichen, Polychidium umhausense (Auersw.) Henss., and contain a cyanophyte phycobiont, Nostoc. A few growths also contain scattered colonies of a chlorophyte phycobiont, in which case the lichen tissue locally assumes the foliose form characteristic of the parent Lobaria thallus. The differentiation of dorsiventral lichen cortices and the formation of a lax medulla and distinct algal layer are correlated with the presence of the green phycobiont. The lichen substances atranorin, gyrophoric acid, and 4‐0‐methylgyrophoric acid occur in both, the foliose L. erosa thallus and the fruticose tissue. It is suggested that the fruticose structures are erumpent cephalodia which are derived from the outgrowth of internal, cephalodia and should not be considered, to be epiphytic colonies of the lichen Polychidium.
FIVE NEW SPECIES OF CHLAMYDOMONAS1,2
Authors: King Joe M.
Published: August 2007

Five new species of Chlamydomonas, C. isabeliensis, C. pallidostigmatica, C. fottii, C. pseudomicrosphaera, and C. texensis are described. Supplementary attributes of these organisms are considered as possible taxonomic aids.
DICHOTOMOSIPHON IN FLORIDA SPRINGS1
Authors: Davis J. S. , Gworek W. F.
Published: August 2007

Dichotomosiphon tuberosus occurs abundantly in the outflows, pools, and streams of at least 5 hard, freshwater springs of north central Florida. This tubular alga produces extensive bright green mats which harbor epiphytes, unicellular algae, ciliates, and amphipods. Within the spring, most tubes remain in the vegetative condition. After 12–15 days under certain laboratory conditions, the tubes produce highly characteristic, sex organs and akinetes.
THE BIOCHEMICAL ANALYSIS OF SOME ESTUARINE PHYTOPLANKTON SPECIES. I. FATTY ACID COMPOSITION12
Authors: DeMort Carole L. , Lowry Robert , Tinsley Ian , Phinney H. K.
Published: August 2007

The fatty acid composition of 10 species of estuarine phytoplankton was determined using gas‐liquid chromatography. Nine of the species were isolated from Yaquina Bay, Oregon. These species were common components of the phytoplankton of the bay. The tenth species, Isochrysis galbana, was obtained from the Culture Collection of Algae at Indiana University. The 10 organisms comprised 3 species of Chlorophyta, 1 species of Cryptophyta, and 6 species of Chrysophyta.

Twenty‐eight fatty acids were found in the 10 species. The fatty acids common to all species were 14:0, 16:0, 16:1, 13:0, 18:1, and 18:2. The Chlorophyta were distinguished by a high content of linolenic acid, 18:3. The diatoms were distinguished by very low amounts of C18 acids and high proportion of 20:5. All species contained a high proportion of palmitic acid, 16:0.
THE UPTAKE OF UREA BY MARINE PHYTOPLANKTON1
Authors: McCarthy James J.
Published: August 2007

Half‐saturation constants for urea uptake by 4 clones of neritic diatoms capable of utilizing urea were determined from short‐term uptake studies with15N‐labeled urea.K8values obtained were similar to those determined, earlier for ammonium, and since ammonium and urea concentrations are similar in the marine environment, it was concluded that these species are capable of utilizing ecologically significant concentrations of urea. Two of 3 species unable to grow on urea showed patterns of short‐term uptake not unlike those of species capable of utilizing urea, which implies that, their assimilatory rather than uptake processes are defective with, regard to urea utilization. The third species initially took15N (supplied as urea) into the cells but subsequently released it back into the medium.
SOME OBSERVATIONS ON COLONIES AND ULTRASTRUCTURE OF THE FRUSTULE OF COENOBIODISCUS MURIFORMIS AND ITS TRANSFER TO PLANKTONIELLA1
Authors: Round F. E.
Published: August 2007

The marine planktonic diatom Coenobiodiscus muriformis has been reinvestigated using light microscopy and scanning and transmission electron microscopy; as a result it is proposed, to transfer the species to the genus Planktoniella. The structure and formation of colonies are discussed and compared with data from an earlier study. Further details of valve and girdle baud structure have been ascertained and the exact form of the central and peripheral tubes has been described. The relationship of the present taxon to Thalassiosira and Coscinodiscus is discussed.
POLYMORPHISM IN THE DESMID MICRASTERIAS LATICEPS AND ITS TAXONOMICAL IMPLICATIONS1
Authors: de Mattos Bicudo Carlos Eduardo , Sormus Laine
Published: August 2007

This paper refers to a case of polymorphism in the desmid Micrasterias laticeps Nordst. It is based on material collected from an artificial pond in the state of São Paulo, Brazil.

A detailed examination of almost 400 specimens permitted the authors to give a detailed description of 13 main morphological forms of the alga and allowed them to draw the following conclusions: (1) For delimitation of genera and infrageneric taxa in desmids it is often necessary to examine sample populations; (2) the morphological characteristics presently used for delimitation of varieties in M. laticeps Nordst. seem to have no considerable taxonomic significance if isolated individuals are studied; (3) it is necessary to take into consideration Cosmarium arthrodesmiforme Borge and C. arthrodesmiforme var. latius Krieg. & Gerl., as well as M. laticeps Nordst. var. ampliata Krieg., when further studies are undertaken, because they may prove to be merely distinct morphological expressions of M. laticeps Nordst var. laticeps.
THE ULTRASTRUCTURE AND MORPHOLOGICAL VARIABILITY OF THE FRUSTULE OF STEPHANODISCUS INVISITATUS HOHN AND HELLERMAN1
Authors: Lowe Rex L. , Crang Richard E.
Published: August 2007

Stephanodscus invisitatus Hohn and Hellerman, studied by means of light, transmission, and scanning electron microscopy, shows a range of frustule diameters from 6.4 to 13.3 μ. Variation in valve ornamentation can be correlated with specimen diameter. The striae number ranges from 16 to 20 in 10 μ. Various processes difficult to observe by light microscopy alone are described which arise from the inside and outside of the frustules.2
NITROGEN METABOLISM OF AQUATIC ORGANISMS. II. THE ASSIMILATION OF NITRATE, NITRITE, AND AMMONIA BYBIDDULPHIA AURITA1
Authors: Lui Nan S. T. , Roels Oswald A.
Published: August 2007

Biddulphia aurita, a centric diatom, can grow on either nitrate, nitrite, or ammonia as its sole nitrogen, source.

Cells remove ammonium nitrogen from the medium 2.3–2.4 times faster than either nitrate or nitrite nitrogen and, when grown for 24 hr in the ammonium medium, contain higher levels of non‐protein nitrogen than cells grown in the nitrate or nitrite medium for the same period of time.

The nitrogenous compounds in the nonprotein nitrogen fraction from cells grown in the nitrate, nitrite, or ammonium medium contain the same level of soluble‐free amino nitrogen, combined amino nitrogen, and ammonium nitrogen. The high level of soluble nonprotein nitrogen in the medium of the cells grown in the ammonium medium is due to soluble amide nitrogen which represents 18% of the total soluble nitrogen present in these cells, whereas it represents only 2% in cells from the nitrite medium, and its level is negligible in cells from the nitrate medium.

Cells grown in the nitrate medium have both nitrate‐ and nitrite‐reductase activity. Cells grown in the nitrite medium have only nitrite‐reductase activity in significant levels, while cells grown in the ammonium medium lack both enzymes.
DNA‐BINDING PROTEIN AND THE CELL CYCLE INCRYPTOTHECODINIUM COHNII.I. ON THE RESOLUTION OF METABOLICALLY STABLE COMPONENTS1
Authors: Franker Colin K.
Published: August 2007

A soluble protein extract, obtained after35S labeling exponential cultures ofCryptothecodinium cohniifor 4–5 generations, was fractionated on DNA‐cellulose. The protein eluted at high salt concentrations from this homologous DNA‐containing matrix was then separated, by chromatography on BioGel P150 and P200 sieve gels. Two prominent chromatographic species of 22,000 and 35,000 daltons plus a substantial amount of material in the molecular weight range of 80,000–140,000 were resolved. The application of this analytical procedure to the study of transcriptional control in the cell cycle is discussed.