Search

Nature's diversity offers an abundance of promising solutions for novel bioinspired functional materials and systems. In particular, single‐celled organisms exhibit solutions and material properties that are realized at the nano‐ and micro‐scales. Ciliates are ubiquitous unicellular eukaryotes that are well‐adapted to a wide range of environmental conditions. They have developed a large variety of interesting and highly specialized characteristics with unique properties and design. In this review, the background of selected ciliate characteristics is highlighted with respect to material properties and structure‐function relationships. Hierarchically complex mineralized structures, highly efficient sensors for movement and protection, shape‐memory structures, as well as survival and detoxification strategies are to be emphasized. Proposed future bioinspired applications of these properties of ciliates expand the possibilities to more sustainable materials and development processes. [ABSTRACT FROM AUTHOR]

Blepharismins are photodynamic hypericin‐like dianthrones produced as a variable pigment blend in Blepharisma ciliates and mostly studied in the Afro‐Asiatic Blepharisma japonicum. The present work describes the bioactivity of pigments from the Brazilian Blepharisma sinuosum. Comparative analyses showed that the pigments from both species can trigger photo‐induced modifications in phospholipids, but different redox properties and biological activities were assigned for each pigment blend. Stronger activities were detected for B. sinuosum pigments, with the lethal concentration LC50 10 × lower than B. japonicum pigments in light‐irradiated tests against Bacillus cereus and less than half for treatments on the human HeLa tumor cells. HPLC showed B. sinuosum producing a simpler pigment blend, mostly with the blepharismin‐C (~ 70%) and blepharismin‐E (~ 30%) types. Each blepharismin engaged a specific dose–response profile on sensitive cells. The blepharismin‐B and blepharismin‐C were the most toxic pigments, showing LC50 ~ 2.5–3.0 µm and ~ 100 µm on B. cereus and HeLa cells, respectively, after illumination. Similarity clustering analysis compiling the bioactivity data revealed two groups of blepharismins: the most active, B and C, and the less active, A, D and E. The B. sinuosum pigment blend includes one representative of each clade. Functional and medical implications are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Endosymbiotic interactions are frequently found in nature, especially in the group of protists. Even though many endosymbioses have been studied in detail, little is known about the mechanistic origins and physiological prerequisites of endosymbiont establishment. A logical step towards the development of endocytobiotic associations is evading digestion and escaping from the host's food vacuoles. Surface properties of bacteria are probably involved in these processes. Therefore, we chemically modified the surface of a transformant strain of Escherichia coli prior to feeding to Tetrahymena pyriformis. N‐(3‐dimethylaminopropyl)‐N’‐ethylcarbodiimide allows any substance carrying amino‐ or carboxyl groups to be bound covalently to the bacterial surface by forming a peptide bond, thus, altering its properties biochemically and biophysically in a predictable manner. The effect of different traits on digestion of T. pyriformis was examined by fluorescence and transmission electron microscopy. The efficiency of digestion differs considerably depending on the coupled substances. Alkaline substances inhibit digestion partially, resulting in incomplete digestion and slightly enhanced escape rates. Increasing hydrophobicity leads to much higher escape frequencies. Both results point to possible mechanisms employed by pathogenic bacteria or potential endosymbionts in evading digestion and transmission to the host's cytoplasm. [ABSTRACT FROM AUTHOR]

Colourless, nonscaled chrysophytes comprise morphologically similar or even indistinguishable flagellates which are important bacterivors in water and soil crucial for ecosystem functioning. However, phylogenetic analyses indicate a multiple origin of such colourless, nonscaled flagellate lineages. These flagellates are often referred to as "Spumella-like flagellates" in ecological and biogeographic studies. Although this denomination reflects an assumed polyphyly, it obscures the phylogenetic and taxonomic diversity of this important flagellate group and, thus, hinders progress in lineage- and taxon-specific ecological surveys. The smallest representatives of colourless chrysophytes have been addressed in very few taxonomic studies although they are among the dominant flagellates in field communities. To overcome the blurred picture and set the field for further investigation in biogeography and ecology of the organisms in question, we studied a set of strains of specifically small, colourless, nonscaled chrysomonad flagellates by means of electron microscopy and molecular analyses. They were isolated by a filtration-acclimatisation approach focusing on flagellates of around 5 µm. We present the phylogenetic position of eight different lineages on both the ordinal and the generic level. Accordingly, we describe the new genera Apoikiospumella, Chromulinospumella, Segregatospumella, Cornospumella and Acrispumella Boenigk et Grossmann n. g. and different species within them. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the peri-implant soft and hard tissue adaptation at implants with different modified surfaces and configurations. Materials and Methods Six Beagle dogs were used. Mandibular premolars and first molars were extracted bilaterally. After 3 months, full-thickness flaps were elevated, and two different types of trans-mucosal implants ( ICX- Gold®, Medentis Medical Gmb H, Dernau, Germany and SLActive®, Institute Straumann, Bern, Switzerland) and two different surfaces were randomly installed in the distal regions of one side of the mandible. Abutments were applied, and a nonsubmerged healing was allowed. After 1 month, the procedures were performed in the other side of the mandible, and after a further month, the animals were sacrificed, biopsies were collected, and ground sections prepared for histological examination. Results Similar results in marginal bone and soft tissues dimensions were observed after 1 month of healing at the two implant systems used, and no major changes could be observed after 2 months of healing. After 1 month, the percentage of new bone was 69.0% and 68.8% at ICX- Gold and SLActive surfaces, respectively. After 2 months, the percentage of new bone was 67.8% and 71.9% at ICX- Gold Medentis and SLActive surfaces, respectively. No statistically significant differences in osseointegration were found. Conclusion The two implant systems used resulted in similar osseointegration after 1 and 2 months of healing. [ABSTRACT FROM AUTHOR]

Objective To compare peri-implant soft- and hard-tissue integration at implants installed juxta- or sub-crestally. Furthermore, differences in the hard and soft peri-implant tissue dimensions at sites prepared with drills or sonic instruments were to be evaluated. Material and methods Three months after tooth extraction in six dogs, recipient sites were prepared in both sides of the mandible using conventional drills or a sonic device ( Sonosurgery®). Two implants with a 1.7-mm high-polished neck were installed, one with the rough/smooth surface interface placed at the level of the buccal bony crest (control) and the second placed 1.3 mm deeper (test). After 8 weeks of non-submerged healing, biopsies were harvested and ground sections prepared for histological evaluation. Results The buccal distances between the abutment/fixture junction ( AF) and the most coronal level of osseointegration (B) were 1.6 ± 0.6 and 2.4 ± 0.4 mm; between AF and the top of the bony crest (C), they were 1.4 ± 0.4 and 2.2 ± 0.2 mm at the test and control sites, respectively. The top of the peri-implant mucosa ( PM) was located more coronally at the test (1.2 ± 0.6 mm) compared to the control sites (0.6 ± 0.5 mm). However, when the original position of the bony crest was taken into account, a higher bone loss and a more apical position of the peri-implant mucosa resulted at the test sites. Conclusions The placement of implants into a sub-crestal location resulted in a higher vertical buccal bone resorption and a more apical position of the peri-implant mucosa in relation to the level of the bony crest at implant installation. Moreover, peri-implant hard-tissue dimensions were similar at sites prepared with either drills or Sonosurgery®. [ABSTRACT FROM AUTHOR]

Aim To describe the sequential healing after elevation of the maxillary sinus mucosa applying the lateral access technique with the use of autogenous bone grafting without membrane to occlude the osteotomy access. Material and methods Immediately after the elevation of the maxillary sinus Schneiderian membrane, applying the lateral access technique in 10 minipigs, autologous bone was harvested from the lateral aspect of the mandibular molar region and ground into particles with a bone mill. The space under the Schneiderian membrane was filled with this graft. No membranes were placed onto the access osteotomy. The healing was evaluated after 15, 30, 90 and 180 days. Paraffin sections were prepared and analyzed histologically. Results After 15 days of healing, the elevated area was mainly filled with provisional matrix, newly formed bone and some remnants of bone chips, and appeared reduced in volume compared with that at the time of surgery. After 30 days of healing, further shrinkage of the height of the elevated space was found, with similar percentages of the different tissue components. After 90 and 180 days, the area underneath the Schneiderian membrane appeared reduced in volume and condensed toward the base of the sinus. The bone tissues appeared to be more mature, both for the mineralized and the non-mineralized portions, while connective tissue occupied 20% of the space, most likely related to the lack of the use of a membrane occluding the access at the time of surgery. Conclusions Suboptimal healing outcomes with respect to augmentation of the space under the sinus floor membrane were documented when autologous bone chips were used as a filler and no membrane was applied to cover the access. [ABSTRACT FROM AUTHOR]

Objective To compare peri-implant tissue healing at implants installed in sites prepared with conventional drills or a sonic device. Material and methods In six Beagle dogs, the mandibular premolars and first molars were extracted bilaterally. After 3 months, full-thickness muco-periosteal flaps were elevated and recipient sites were prepared in both sides of the mandible. In the right side (control), the osteotomies were prepared using conventional drills, while, at the left side (test), a sonic device (Sonosurgery®) was used. Two implants were installed in each side of the mandible. After 8 weeks of non-submerged healing, biopsies were harvested and ground sections prepared for histological evaluation. Results The time consumed for the osteotomies at the test was more than double compared to the conventional control sites. No statistically significant differences were found for any of the histological variables evaluated for hard and soft tissue dimensions. Although not statistically significant, slightly higher mineralized bone-to-implant contact was found at the test (65.4%) compared to the control (58.1) sites. Conclusions Similar healing characteristics in osseointegration and marginal hard tissue remodeling resulted at implants installed into osteotomies prepared with conventional drills or with the sonic instrument (Sonosurgery®). [ABSTRACT FROM AUTHOR]

Aim To describe the sequential healing of open extraction sockets at which no attempts to obtain a primary closure of the coronal access to the alveolus have been made. Material and methods The third mandibular premolar was extracted bilaterally in 12 monkeys, and no sutures were applied to close the wound. The healing after 4, 10, 20, 30, 90 and 180 days was morphometrically studied. Results After 4 days of healing, a blood clot mainly occupied the extraction sockets, with the presence of an inflammatory cells' infiltrate. A void was confined in the central zones of the coronal and middle regions, in continuity with the entrance of the alveoli. At 10 days, the alveolus was occupied by a provisional matrix, with new bone formation lining the socket bony walls. At 20 days, the amount of woven bone was sensibly increasing. At 30 days, the alveolar socket was mainly occupied by mineralized immature bone at different stages of healing. At 90 and 180 days, the amount of mineralized bone decreased and substituted by trabecular bone and bone marrow. Bundle bone decreased from 95.5% at 4 days to 7.6% at 180 days, of the whole length of the inner alveolar surface. Conclusions Modeling processes start from the lateral and apical walls of the alveolus, leading to the closure of the socket with newly formed bone within a month from extraction. Remodeling processes will follow the previous stages, resulting in trabecular and bone marrow formation and in a corticalization of the socket access. [ABSTRACT FROM AUTHOR]

Aim To evaluate the influence of the width of the buccal bony wall on hard and soft tissue dimensions following implant installation. Material and methods Mandibular premolars and first molars of six Labrador dogs were extracted bilaterally. After 3 months of healing, two recipient sites, one on each side of the mandible, were prepared in such a way as to obtain a buccal bony ridge width of about 2 mm in the right (control) and 1 mm in the left sides (test), respectively. Implants were installed with the coronal margin flush with the buccal alveolar bony crest. Abutments were placed and the flaps were sutured to allow a non-submerged healing. After 3 months, the animals were euthanized and ground sections obtained. Results All implants were completely osseointegrated. In respect to the coronal rough margin of the implant, the most coronal bone-to-implant contact was apically located 1.04 ± 0.91 and 0.94 ± 0.87 mm at the test and control sites, respectively, whereas the top of the bony crest was located 0.30 ± 0.40 mm at the test and 0.57 ± 0.49 mm at the control sites. No statistically significant differences were found. A larger horizontal bone resorption, however, evaluated 1 mm apically to the rough margin, was found at the control (1.1 ± 0.7 mm) compared to the test (0.3 ± 0.3 mm) sites, the difference being statistically significant. A thin peri-implant mucosa (2.4-2.6 mm) was found at implant installation while, after 3 months of healing, a biological width of 3.90-4.40 mm was observed with no statistically significant differences between control and test sites. Conclusions A width of the buccal bony wall of 1or 2 mm at implant sites yielded similar results after 3 months of healing in relation of hard tissue and soft tissues dimensions after implant installation. [ABSTRACT FROM AUTHOR]

Aim To evaluate the influence of deproteinized bovine bone mineral ( DBBM), in conjunction with a collagen membrane, on bone resorption at implants installed in a lingual position immediately into extraction sockets with horizontal residual buccal defects >2.0 mm. Material & methods The pulp tissue of the mesial roots of 1M1 was removed in six Labrador dogs, and the root canals were filled with gutta-percha and cement. Flaps were elevated. The molars were hemi-sectioned and the distal roots removed. Implants were installed in a lingual position and with the shoulder flush with the buccal bony crest. After installation, defects of about 2.5 and 2.7 mm in width resulted at the buccal aspects of the test and control sites, respectively. Only in the left site (test), deproteinized bovine bone mineral ( DBBM) particles were placed into the defect concomitantly with the placement of a collagen membrane. On the control sites, no biomaterials were applied. A non-submerged healing was allowed. Results After 3 months of healing, one control implant was not integrated and was excluded from the analysis, together with the contralateral test implant. All remaining implants were integrated into mature bone. The buccal alveolar bony crest was resorbed more at the test compared with the control sites, 2.2 ± 0.9 mm and 1.5 ± 1.3 mm, respectively. The vertical resorption of the lingual plate was 1.6 ± 1.5 mm and 1.5 ± 1.1 mm at the test and control sites, respectively. Only small residual DBBM particles were found at the test sites (1.4%). Conclusion The use of DBBM particles to fill buccal defects of ≥2.5 mm at implants installed immediately into alveolar extraction sockets did not preserve the buccal bony wall. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the effect of a space-maintaining device fixed to the lateral wall of the maxillary sinus after the elevation of the sinus mucosa on bone filling of the sinus cavity. Material and methods: Immediately after the elevation of the maxillary sinus Schneiderian membrane accomplished through lateral antrostomy in four monkeys, a titanium device was affixed to the lateral sinus wall protruding into the sinus cavity to maintain the mucosa elevated without the use of grafting material. The healing of the tissue around the implants was evaluated after 3 and 6 months. Ground sections were prepared and analyzed histologically. Results: The void under the elevated sinus membrane, originally filled with the blood clot, was reduced after 3 as well as after 6 months of healing of about 56% and 40.5%, respectively. In seven out of eight cases, the devices had perforated the sinus mucosa. The formation of mineralized bone and bone marrow amounted to about 42% and 69% after 3 and 6 months, respectively. The connective tissue represented about 53% and 23% of the newly formed tissue after 3 and 6 months, respectively. Conclusions: New bone formation was found below the devices. However, shrinkage of the newly formed tissue was observed both after 3 and 6 months of healing. Hence, the space-maintaining function of the devices used in the present study has to be questioned. To cite this article: Schweikert M, Botticelli D, de Oliveira JA, Scala A, Salata LA, Lang NP. Use of a titanium device in lateral sinus floor elevation: an experimental study in monkeys. Clin. Oral Impl. Res. 23, 2012; 100-105. doi: 10.1111/j.1600-0501.2011.02200.x [ABSTRACT FROM AUTHOR]

To evaluate the influence (i) of various implant platform configurations and (ii) of implant surface characteristics on peri-implant tissue dimensions in a dog model. Mandibular premolars and first molars were extracted bilaterally in six Labrador dogs. After 3 months of healing, two implants, one with a turned and a second with a moderately rough surface, were installed on each side of the mandible in the premolar region. On the right side of the mandible, implants with a tapered and enlarged platform were used, while standard cylindrical implants were installed in the left side of the mandible. Abutments with the diameter of the cylindrical implants were used resulting in a mismatch of 0.25 mm at the tapered implant sites. The flaps were sutured to allow a non-submerged healing. After 4 months, the animals were sacrificed and ground sections were obtained for histometric assessment. All implants were completely osseointegrated. A minimal buccal bone resorption was observed for both implant configurations and surface topographies. Considering the animals as the statistical unit, no significant differences were found at the buccal aspect in relation to bone levels and soft tissue dimensions. The surface topographies did not influence the outcomes either. The present study failed to show differences in peri-implant tissue dimensions when a mismatch of 0.25 mm from a tapered platform to an abutment was applied. The surface topographies influence a neither marginal bone resorption or peri-implant soft tissue dimension. Baffone GM, Botticelli D, Pantani F, Cardoso LC, Schweikert MT, Lang NP. Influence of various implant platform configurations on peri-implant tissue dimensions: an experimental study in dog. Clin. Oral Impl. Res. , 2011; 438-444. [ABSTRACT FROM AUTHOR]

Molecular analyses and subsequent morphological reinvestigation of clonal isolates germinated from cysts previously assigned toScrippsiella hangoei(Schiller) Larsen revealed considerable differences to vegetative cell isolates of this cold-water dinoflagellate from the northern Baltic Sea. The presence of hexagonal platelets on the cell surface and a characteristic acrobase on the episome agree with the description ofGymnodinium halophilumBiecheler. However, the arrangement of amphiesmal vesicles in more than nine latitudinal series indicates allocation of this dinoflagellate toWoloszynskiaThompson. We therefore reassignG. halophilumtoWoloszynskia halophila. This species exhibits ultrastructural characteristics similar toPolarella glacialisMontresor et al. and symbionticGymnodiniumStein, such as stalked pyrenoids and a central eyespot consisting of multiple layers of crystal-filled vacuoles. A close relationship between these dinoflagellates is also supported by 28s rRNA sequence data. The preference for high salinities identifiesW. halophilaas a marine species. The spiny resting cysts ofW. halophilaare identical to the cysts formed during the massive encystment events previously attributed toS. hangoeiin the Baltic Sea. This suggests thatW. halophilais a significant contributor to the dinoflagellate spring blooms in the Baltic Sea.Scrippsiella hangoeiclones, in turn, produce noncalcareous and smooth-walled cysts when crossed with a complementary mating type. [ABSTRACT FROM AUTHOR]

A new thecate, phototrophic, marine, sand-dwelling dinoflagellate,Thecadinium mucosumHoppenrath et Taylor sp. nov., is described from a culture isolated from Boundary Bay, British Columbia, Canada. It was illustrated with LM as well as SEM and TEM, and its position in the phylogenetic tree of dinoflagellates was investigated using molecular methods. Cells are asymmetrical, oval, laterally flattened, and strongly pigmented, with the plate formula P 3′ 1a 6′′ 7/8c 5 s 6′′′ 2′′′′. Thecal plates are smooth with scattered pores, and there is a distinctive anterior intercalary plate that could be involved in mucus secretion.Thecadinium inclinatumBalech (= Sabulodinium inclinatum(Balech) Saunders et Dodge), a thecate, marine, sand-dwelling species that has been previously confused with what we now callT. mucosum, was also examined and illustrated through LM and SEM. New information onT. inclinatumis provided, including its plate formula P 3′ 6′′ 7c ?s 5′′′ 1p 1′′′′; we considerT. inclinatumto be related to most otherThecadiniumspecies and not toSabulodinium. Molecular phylogenetic analyses based on the small subunit ribosomal gene ofT. mucosum,T. kofoidii(the type species of the genus), andT. dragescoiweakly support earlier suspicions based on morphology thatT. dragescoiis not a member ofThecadinium. Tabulational patterns of the species suggest a relationship to the genusAmphidiniopsis. [ABSTRACT FROM AUTHOR]

Studies the macronucleus of Paramecium caudata by researchers from Russia and Germany. Performance of infection experiments incubating P. caudata with non-infectious free-living bacteria or weakly infectious intracellular bacteria; Access of the non-infectious free-living bacteria into the nuclei when added to Paramecium together with Holospora obtusa; Evidence that H. obtusa may facilitate entry of other non-infectious bacteria into the nuclei of Paramecium.

Three Thecadinium species, independently described as new in three separate publications, are actually regarded as conspecific. The combined plate formula is Po 3′ 1a 6″ 5-7/8c 5s 6″′ 2″″. The size range of the species is 38–65 l m in length and 23–42 lm in depth. It has one or two strongly lobed chloroplasts. The correct name of the species is Thecadinium yashimaense Yoshimatsu, Toriumi et Dodge 2004. Thecadinium mucosum Hoppenrath et Taylor 2004 and Thecadinium foveolatum Bolch 2004 are taxonomical synonyms. This note clarifies the plate tabulation and other features of the species. [ABSTRACT FROM AUTHOR]