New pelagophytes show a novel mode of algal colony development and reveal a perforated theca that may define the class

Pelagophytes (Heterokonta) are a morphologically diverse class of marine algae historically united only by DNA sequences. We established clonal cultures of sand-dwelling pelagophytes collected from intertidal pools around Australia. Phylogenetic trees based on nuclear 18S rDNA and plastid rbcL, psaA, psaB, psbA, and psbC sequences revealed two new genera, Gazia and Glomerochrysis, related to Aureoumbra in a distinct lineage within the Sarcinochrysidaceae (Pelagophyceae). The three new species (Gazia saundersii, Gazia australica, and Glomerochrysis psammophila), along with an Australian strain of Aureoumbra geitleri, are characterized by dominant benthic stages that differ significantly from one another, while occasionally producing classic heterokont zoospores. The benthic stage of Ga. saundersii has a novel development not observed in any other colonial alga, consisting of large, spherical colonies (up to 140 μm in diameter) containing c. 2,500 cells that eventually differentiate and segregate into a large number of daughter colonies that are subsequently liberated. Alternatively, colonies may differentiate into a mass of zoospores that escape and settle to develop into new colonies. In Gl. psammophila, cubic packets of cells form large sticky clusters that bind sand together, while Ga. australica and A. geitleri are unicellular species. Using fixation by high-pressure freezing, a distinctive perforated theca was observed by TEM in all genera of this lineage, and we hypothesize this unique covering may be the first morphological feature to characterize most, if not all, pelagophytes. This study substantiates the diverse nature of sand-dwelling pelagophytes as well as their mechanisms for thriving in a dynamic habitat.

A new marine prasinophyte genus alternates between a flagellate and a dominant benthic stage with microrhizoids for adhesion

Prasinophytes (Chlorophyta) are a diverse, paraphyletic group of planktonic microalgae for which benthic species are largely unknown. Here, we report a sand-dwelling, marine prasinophyte with several novel features observed in clonal cultures established from numerous locations around Australia. The new genus and species, which we name Microrhizoidea pickettheapsiorum (Mamiellophyceae), alternates between a benthic palmelloid colony, where cell division occurs, and a planktonic flagellate. Flagellates are short lived, settle and quickly resorb their flagella, the basal bodies then nucleate novel tubular appendages, termed "microrhizoids", that lack an axoneme and function to anchor benthic cells to the substratum. To our knowledge, microrhizoids have not been observed in any other green alga or protist, are slightly smaller in diameter than flagella, generally contain nine microtubules, are long (3-5 times the length of flagella) and are not encased in scales. Following settlement, cell divisions result in a loose, palmelloid colony, each cell connected to the substratum by two microrhizoids. Flagellates are round to bean-shaped with two long, slightly uneven flagella. Both benthic cells and flagellates, along with their flagella, are encased in thin scales. Phylogenies based on the complete chloroplast genome of Microrhizoidea show that it is clearly a member of the Mamiellophyceae, most closely related to Dolichomastix tenuilepsis. More taxon-rich phylogenetic analyses of the 18S rRNA gene, including metabarcodes from the Tara Oceans and Ocean Sampling Day projects, confidently show the distinctive nature of Microrhizoidea, and that the described biodiversity of the Mamiellophyceae is a fraction of its real biodiversity. The discovery of a largely benthic prasinophyte changes our perspective on this group of algae and, along with the observation of other potential benthic lineages in environmental sequences, illustrates that benthic habitats can be a rich ground for algal biodiscovery.

The golden paradox - a new heterokont lineage with chloroplasts surrounded by two membranes

A marine, sand-dwelling, golden-brown alga is described from clonal cultures established from a high intertidal pool in southeastern Australia. This tiny, unicellular species, which we call the "golden paradox" (Chrysoparadoxa australica gen. et sp. nov.), is benthic, surrounded by a multilayered cell wall and attached to the substratum by a complex adhesive plug. Each vegetative cell gives rise to a single, naked zoospore with heterokont flagella that settles and may become briefly amoeboid prior to dividing. Daughter cells are initially amoeboid, then either permanently attach and return to the benthic stage or become motile again prior to final settlement. Two deeply lobed chloroplasts occupy opposite ends of the cell and are surrounded by only two membranes. The outer chloroplast membrane is continuous between the two chloroplasts via the outer membrane of the nuclear envelope. Only two membranes occupy the chloroplast-nucleus interface, the inner membrane of the nuclear envelope and the inner chloroplast membrane. A small pyrenoid is found in each chloroplast and closely abuts the nucleus or protrudes into it. It contains an unusual, membrane-bound inclusion that stains with SYBR green but is unlikely to be a nucleomorph. Phylogenies inferred from a 10-gene concatenated alignment show an early-branching position within the PX clade. The unusual morphological features and phylogenetic position indicate C. australica should be classified as a new class, Chrysoparadoxophyceae. Despite an atypical plastid, exploration of the C. australica transcriptome revealed typical heterokont protein targeting to the plastid.

Complete mitochondrial genomes of six species of the freshwater red algal order Batrachospermales (Rhodophyta)

Only two mitochondrial (mt) genomes had been reported in members of the red algal order Batrachospermales, which are confined to freshwater habitats. Additional mt genomes of six representative members (Batrachospermum macrosporum, Kumanoa ambigua, K. mahlacensis, Paralemanea sp., Sheathia arcuata, and Sirodotia delicatula) were sequenced aiming to gain insights on the evolution of their mt genomes from a comparative analysis with other red algal groups. Mt genomes sequenced had the following characteristics: lengths ranging between 24,864 nt and 29,785 nt, 22 to 26 protein-coding genes, G + C contents of 21.3 to 30.7%, number of tRNA of 16 to 37, non-coding DNA from 3.8% to 14.8%. Comparative analysis revealed that mt genomes in Batrachospermales are highly conserved in terms of genome size and gene content and synteny. Phylogenetic analyses based on COI nucleotide data revealed high bootstrap support only for the genera usually recovered in the phylogenetic analyses but no support for supra-generic groups. The insertion of a group II intron carrying an ORF coding for the corresponding intron maturase interrupting the COI gene was observed in Paralamenea sp. and accounted for its larger genome in comparison to the other Batrachospermales mt genomes.

Implicações da Adição de Própolis nas Propriedades Físico-Mecânicas do Cimento de Ionômero de Vidro

O objetivo do presente trabalho foi realizar uma revisão da literatura sobre as propriedades físico-mecânicas do cimento de ionômero de vidro (CIV) adicionado de própolis. Para essa finalidade, foi efetuada busca no banco de dados Medline/Pubmed, utilizando os descritores “propolis”, “glass ionomer cements” e “dental materials”, na língua inglesa, no período de 2009 a 2017. Foi encontrado um total de 7 artigos, dos quais foram selecionados 6 após leitura de títulos e resumos, considerando o idioma, o período e o grau de envolvimento do artigo com o tema em questão como critérios de inclusão/exclusão. Como resultados, verificou-se que, embora os estudos apontem melhora dos efeitos antimicrobianos a partir da associação entre a própolis e o CIV, seus efeitos sobre as propriedades físico-mecânicas do cimento ainda não são totalmente conhecidos. Nos artigos selecionados foram avaliadas propriedades como resistência à compressão, solubilidade e sorção de água, com alguns resultados controversos. Tendo em vista que o cimento de ionômero de vidro é um material muito útil e versátil na Odontologia e que a própolis tem sido cada vez mais adicionada a ele    em situações como no tratamento restaurador atraumático e na cimentação de bandas ortodônticas a fim de potencializar a ação antimicrobiana dos CIVs, ainda são necessárias pesquisas adicionais para melhor compreensão dessas peculiaridades.Palavras-chave: Propolis. Glass Ionomer Cements. Dental Materials.

Aplicabilidade de Óleos Essenciais em Materiais Dentários: uma Revisão de Literatura

O objetivo do presente trabalho foi realizar uma revisão de literatura sobre as propriedades terapêuticas dos óleos essenciais (OEs) em Odontologia visando sua aplicabilidade em materiais dentários com ação antimicrobiana. Para tanto, foi realizada uma pesquisa nas bases de dados eletrônicas MEDLINE e BVS, utilizando os descritores Oils, Volatile, Dental Materials e Anti-Infective Agents em português e inglês. Foram encontrados 51 artigos publicados no período de 2007 a 2017 e 15 foram selecionados através de leitura de títulos e resumos, excluindo-se relatos de casos. Durante a análise dos artigos, destacaram-se os OEs de Lippia sidoides, timol, carvacrol e Rosmarinus officinalis que, além de serem de fácil obtenção, apresentaram atividade antibacteriana e antifúngica significativa contra S. Mutans, C. Albicans e E. Faecalis. Essas propriedades apresentadas pelos OEs propiciaram potenciais aplicabilidades em dentifrícios, enxaguatórios bucais, condicionadores de tecido, aplicações intracanal, adesivos e vernizes conferindo-lhes características antimicrobianas importantes no controle dos patógenos orais agindo de forma versátil em diferentes sítios a depender do local de aplicação do material. Importante destacar que a validação científica, clínica e comercial da atividade terapêutica dos OEs em materiais dentários são essenciais para possibilitar avanços na odontologia preventiva e restauradora, possibilitando, alternativas naturais, com poucos efeitos colaterais e que possam melhorar a qualidade de vida dos pacientes.Palavras-chave: Oils. Volatile. Dental Materials. Anti-Infective Agents.

Efeito Antibacteriano do Carvacrol e Timol nos Materiais Dentários: uma Revisão de Literatura

O objetivo desta revisão é descrever a atividade antimicrobiana dos Óleos Essenciais (OE’s) carvacrol e timol e suas aplicações  nos materiais dentários.Foi realizada uma revisão de literatura, utilizando-se as bases de dados “Medline”, “Lilacs” e “SciELO”, os descritores “Anti-infecciosos”, “Thymol”, “Oils, Volatile”, tendo sido encontrados 571 artigos e selecionados 25 publicados entre 2007 e 2017, escritos em inglês, português e/ou espanhol. Relatos de casos foram excluídos. As pesquisas com materiais dentários contendo produtos naturais aumentaram devido à busca por novas substâncias com maior atividade farmacológica, menor toxicidade e maior biocompatibilidade. Dentre os estudos levantados, os OE’s carvacrol e timol se mostraram mais prevalentes. A atividade antibacteriana destes compostos pode ocorrer pela desestabilização da parede celular, aumento da permeabilidade da membrana citoplasmática e pela alteração de vários sistemas enzimáticos, incluindo aqueles envolvidos na produção de energia celular e na síntese de componentes estruturais. Entre as possibilidades de aplicações, estes OE’s foram empregados em soluções irrigadoras para canais radiculares, dentifrícios, exaguatórios bucais e vernizes, demonstrando eficácia antibacteriana. Portanto, estudos desses produtos naturais na odontologia são realizados, visando à obtenção de materiais dentários com agentes antimicrobianos que possibilitem a prevenção e tratamento de doenças bucais, com poucos efeitos colaterais indesejáveis e fácil acesso à população.Palavras-chave: Anti-Infecciosos. Thymol. Oils. Volatile.

Organization of plastid genomes in the freshwater red algal order Batrachospermales (Rhodophyta)

Little is known about genome organization in members of the order Batrachospermales, and the infra-ordinal relationship remains unresolved. Plastid (cp) genomes of seven members of the freshwater red algal order Batrachospermales were sequenced, with the following aims: (i) to describe the characteristics of cp genomes and compare these with other red algal groups; (ii) to infer the phylogenetic relationships among these members to better understand the infra-ordinal classification. Cp genomes of Batrachospermales are large, with several cases of gene loss, they are gene-dense (high gene content for the genome size and short intergenic regions) and have highly conserved gene order. Phylogenetic analyses based on concatenated nucleotide genome data roughly supports the current taxonomic system for the order. Comparative analyses confirm data for members of the class Florideophyceae that cp genomes in Batrachospermales is highly conserved, with little variation in gene composition. However, relevant new features were revealed in our study: genome sizes in members of Batrachospermales are close to the lowest values reported for Florideophyceae; differences in cp genome size within the order are large in comparison with other orders (Ceramiales, Gelidiales, Gracilariales, Hildenbrandiales, and Nemaliales); and members of Batrachospermales have the lowest number of protein-coding genes among the Florideophyceae. In terms of gene loss, apcF, which encodes the allophycocyanin beta subunit, is absent in all sequenced taxa of Batrachospermales. We reinforce that the interordinal relationships between the freshwater orders Batrachospermales and Thoreales within the Nemaliophycidae is not well resolved due to limited taxon sampling.

Chloroplast genomes as a tool to resolve red algal phylogenies: a case study in the Nemaliales

BACKGROUND

Obtaining strongly supported phylogenies that permit confident taxonomic and evolutionary interpretations has been a challenge in algal biology. High-throughput sequencing has improved the capacity to generate data and yields more informative datasets. We sequenced and analysed the chloroplast genomes of 22 species of the order Nemaliales as a case study in the use of phylogenomics as an approach to achieve well-supported phylogenies of red algae.

RESULTS

Chloroplast genomes of the order Nemaliales are highly conserved, gene-dense and completely syntenic with very few cases of gene loss. Our ML estimation based on 195 genes recovered a completely supported phylogeny, permitting re-classification of the order at various taxonomic levels. Six families are recognised and the placement of several previously contradictory clades is resolved. Two new sub-orders are described, Galaxaurineae and Nemaliineae, based on the early-branching nature and monophyly of the groups, and presence or absence of a pericarp. Analyses of subsets of the data showed that >90 % bootstrap support can be achieved with datasets as small as 2500 nt and that fast and medium evolving genes perform much better when it comes to resolving phylogenetic relationships.

CONCLUSIONS

In this study we show that phylogenomics is an efficient and effective approach to investigate phylogenetic relationships. The six currently circumscribed Nemaliales families are clustered into two evolutionary lineages with strong statistical support based on chloroplast phylogenomic analyses. The conserved nature of red algal chloroplast genomes is a convenient and accessible source of data to resolve their ancient relationships.

The plastid genome of the red alga Laurencia

We present the 174,935 nt long plastid genome of the red alga Laurencia sp. JFC0032. It is the third plastid genome characterized for the largest order of red algae (Ceramiales). The circular-mapping plastid genome is small compared to most florideophyte red algae, and our comparisons show a trend toward smaller plastid genome sizes in the family Rhodomelaceae, independent from a similar trend in Cyanidiophyceae. The Laurencia genome is densely packed with 200 annotated protein-coding genes (188 widely conserved, 3 open reading frames shared with other red algae and 9 hypothetical coding regions). It has 29 tRNAs, a single-copy ribosomal RNA cistron, a tmRNA, and the RNase P RNA.

Evolution and diversification within the intertidal brown macroalgae Fucus spiralis/F. vesiculosus species complex in the North Atlantic

We examined 733 individuals of Fucusspiralis from 21 locations and 1093 Fucusvesiculosus individuals from 37 locations throughout their northern hemisphere ranges using nuclear and mitochondrial markers. Three genetic entities of F. spiralis were recovered. In northern and sympatric populations, the presence of "F. spiralis Low" in the mid-intertidal and "F. spiralis High" in the high-intertidal was confirmed and both co-occurred with the sister species F. vesiculosus. The third and newly-discovered entity, "F. spiralis South", was present mainly in the southern range, where it did not co-occur with F. vesiculosus. The South entity diverged early in allopatry, then hybridized with F. vesiculosus in sympatry to produce F. spiralis Low. Ongoing parallel evolution of F. spiralis Low and F. spiralis High is most likely due to habitat preference/local selection and maintained by preferentially selfing reproductive strategies. Contemporary populations of F. spiralis throughout the North Atlantic stem from a glacial refugium around Brittany involving F. spiralis High; F. spiralis South was probably unaffected by glacial episodes. Exponential population expansion for F. vesiculosus began during the Cromer and/Holstein interglacial period (300,000-200,000 yrs BP). Following the last glacial maximum (30,000-22,000 yrs BP), a single mtDNA haplotype from a glacial refugium in SW Ireland colonized Scandinavia, the Central Atlantic islands, and the W Atlantic.

Effects of substance abuse on hallucination rates and treatment responses in chronic psychiatric patients

BACKGROUND

Few data systematically document the effects of illicit drug exposure on psychotic illness. We examined the effect of substance abuse on rates and treatment responses of hallucinations in a chronic psychiatric population.

METHOD

113 cooperative patients consecutively admitted to a state psychiatric hospital were administered the Structured Clinical Diagnostic Interview for DSM-III-R, a Hallucination Interview, and an inventory of past and current substances of abuse. Demographic information was obtained on 104 of 108 patients who declined interview. Medication dosage was analyzed for one third of the interviewed sample; hospital records, nursing reports, contacts with relatives, and urine drug screens were used to confirm information from patient interviews. Hallucination rates and response were compared by diagnostic groups (chi-square).

RESULTS

Noninterviewed patients had more frequent hospitalizations, more patients diagnosed with psychosis not otherwise specified or schizoaffective disorder, and fewer females with comorbid substance abuse than the study population. Among interviewed subjects, those with substance abuse and psychiatric illness had first admissions at an earlier age than patients with no substance abuse (p = .005). Schizophrenics experienced higher rates of visual (p = .04) and olfactory (p = .05) hallucinations when using illicit drugs. Substance abuse was associated with decreased treatment responsiveness of auditory (p < .03) and tactile (p < .004) hallucinations in schizophrenic or manic patients. Compared with nonparanoid patients, there was a trend for paranoid schizophrenics with substance abuse to experience more frequent visual (p = .09) and tactile (p = .06) and more refractory auditory (p = .08) hallucinations. No differences in medication dosages were found between patients with treatment-responsive and treatment-refractory hallucinations.

CONCLUSIONS

Abused substances may interact selectively with primary psychiatric illness to increase rates and treatment resistance of specific hallucination modalities; etiologies are discussed.

High potency neuroleptics and violence in schizophrenics

In a controlled study, inpatient violence was measured during placebo, high-potency (haloperidol) and low-potency (chlorpromazine or clozapine) neuroleptics. Some patients had a marked increase in violent behavior with the moderately high-dose haloperidol, but not with low-potency neuroleptics. The authors discuss reasons for the increased violence with haloperidol, including akathisia and drug-induced behavioral toxicity.

Efficacy of adjunctive carbamazepine in the treatment of chronic schizophrenia

Six treatment-resistant schizophrenic patients were given a ten-week single-blind trial of carbamazepine. Treatment resistance was determined on the basis of documented failure to respond to treatment with at least three neuroleptic drugs from two different chemical classes. The adjunctive use of carbamazepine resulted in a significant improvement of the negative symptoms of schizophrenia. These symptoms are often poorly responsive to conventional antipsychotic drugs. Therefore, controlled studies should be performed to further assess the possible efficacy of carbamazepine in schizophrenia.

Chromatographic and spectral properties of some aryl-substituted phencyclidine analogs

As part of a search for phencyclidine (PCP) antagonists, a series of eleven aryl-substituted PCP analogs were prepared and characterized. TLC and GC elution profiles of these derivatives are described in a number of systems allowing for the tentative identification of the PCP analogs. Further, MS, NMR, UV/vis and IR spectral tabulations are provided. Correlation of chromatographic character with physical organic structure parameters, such as those of Hammet, showed good predictability.