Early Stages Of Culture Research Articles

Accumulation of selenium in a Chinese cabbage of a grade Pak-choi in the course of cultivation

Most agricultural areas of Russia have soils poor in mineral selenium, causing higher oncology risks for population of such areas. The way to control malignancy incidence is selenium fortification of soils and plants. This can be achieved by agrochemical enrichment of cultivated plants with nutritive substrates containing essential minerals and trace elements. The current study aimed to assay the effect of inorganic selenium on the rate of Chinese pakchoi cabbage biomass gain for the development of agrochemical techniques for introducing selenium. The optimal selenium introduction technique would demonstrate the best balance of biomass gain rate and selenium ion accumulation in organic matter. Selenium ion accumulation dynamic was assessed during controlled growth of plants in soils enriched with nutritive substrate containing inorganic selenium (potassium selenite). The amount of selenium in plants was determined by spectroscopy. Mathematical functions describing the selenium uptake dynamic of controlled grown plants have been found, including derivatives of these functions that led to obtaining the numerical values of the respective uptake rates. It has been found that agricultural techniques that involve introduction of selenium at intermediate and late stages of cultivation are optimal for plant growth dynamic, as introducing selenium at early stages of cultivation has a negative impact on biomass uptake rates. Additionally, introducing potassium selenite to the nutritive substrate at 1.0 mg×dm–3 proved to be more effective than introducing potassium selenite at 0.5 mg×dm–3 as the former dosage led to a better plant growth dynamic.

АНТРОПОЛОГИЧЕСКОЕ ИССЛЕДОВАНИЕ РАННЕЯКУТСКОГО АТЛАСОВСКОГО ПОГРЕБЕНИЯ XIV–XV ВЕКОВ

The burial near Lake Atlasovskoye, Yakutia, is one of the earliest Yakut burials, dating back to the 14th or 15th centuries and associated with the medieval Kulun-Atakh culture. Initially, its age was assessed by the comparative typological method based on artifacts, and later а radiocarbon estimate was generated, suggesting that the burial dates to the early stage of the Kulun-Atakh culture. Its highly unusual feature is that the individual was buried in a seated position – an exceptional case in the Yakut funerary practice. The cranium was completely wrapped in a bandage sewn from birchbark sheets, under which lethal injuries were found. Our comprehensive study was aimed at assessing the individual’s lifestyle and cause of death. Postcranial bones revealed pathologal symptoms unusual for an early age (20–25) and caused by excessive physical strain, suggesting that the man was either a slave or a warrior. The complex birchbark bandage may indicate high status. Together with the seated position of the body, this makes the military status even more likely. Multiple traumatic lesions inflicted with a cutting tool indicate the violent nature of conflicts at the early stage of the Yakut culture. Craniometruic analysis reveals Buryat and Mongol affi nities, supporting epic evidence relating to Yakut origins, in which Buryat or Mongol immigrants had taken part.

The Etymological Sense of Truth in Early China

This paper aims to explore the understanding and evolution of the concept of ‘truth’ (眞 理) in the earliest stages of Chinese history on the basis of oracle bone script zhen (貞) and the inscriptions zhen (眞). It further aims to prove that zhen (貞) and zhen (眞) are cognate words. ‘Truth’ in English is commonly translated as zhen (眞) in Chinese. However, it is not easy to find an intersection between two notions of ‘truth’ in the early stage of Eastern and Western culture in spite of a great deal of controversies over the notions in sinological studies, since there was almost no cultural exchange between the East and the West before the modern era. After the nineteenth century, with the expansion of the Western power, Westerners attempted to understand the manifold ways of Eastern thought. Thus, many concepts that were dominant in Western thinking were transplanted in many areas of Eastern thinking; the concept of ‘truth’ (眞理) is such a case. The Western concept of ‘truth’ (眞理) pursues correspondence theory, based on the dichotomy of true and false. Based on this idea, many Western scholars still claim that the notion of ‘zhen’ used in Chinese classical texts can not be equated with “truth” used in Europe and Anglo-American dominant philosophy. Therefore, I would like to return to the primitive sense of truth in the oracle bone script, explore the pre-theoretic understanding of truth before concrete forms of knowledge such as Confucianism and Buddhism were introduced, to show the interconnectedness of zhen (眞) and zhen (貞). Traditional interpretations of zhen (眞) can be roughly classified into three types: ‘a Daoist ascetic with miraculous powers’ (神仙)(see Xu Shen, Duan Yucai, et al.); ‘treasure’ (see Tang Lan, Ma Xulun, Zhou Fangfu, He Linyi, etc), and ‘death as unchanging status’ (see Shirakawa). Among these, the first version of zhen has been considered most authentic, because Shuowen Jiezi《說文解字》, the first authoritative dictionary of Chinese characters, defines zhen (眞) as “a Daoist hermit transforming shape and ascending into Heaven ( 僊人變形而登天也)” with Daoist connotations. Such interpretations, though dominent, were based on Xiaoshuan and did not seem to include closer investigations of zhen (貞), the older form of zhen (眞), based on recently unearthed literatures. Though contemporary archaeological studies provide evidence of more ancient origins, it is difficult to extract the original sense from the primitive script of zhen (貞), because it was only used as the name of a place or a person. This paper thus follows several hypotheses: 1. zhen (眞) is cognate with zhen (貞); 2. zhen (貞) in oracle bone script means ‘to ask Heaven questions from signs or omens obtained by burning tortoise shells or animal bones’ and a person in charge of performing a divination rituals’ is known as a diviner(zhenren ‘貞人’); 3. zhen (貞) was specified into zhen (眞); 4. Under the influence of Daoism during the early Han Dynasty, zhen (眞) was defined as ‘a Daoist hermit’ (神仙), and then acquired the meaning of truth after the introduction of Buddhism. The strategies of the paper are as follows: firstly I will analyze zhen (眞) by breaking it into its component characters and trace back its original forms and senses of zhen in oracle bone scripts; secondly, I will examine its usage in the ancient literatures based on phonetic and semantic patterns; finally I will try to place possible coordinates of ‘truth’ among constellations of various meanings of zhen (貞) and zhen (眞).

Reduction of Candida biofilm adhesion by incorporation of prereacted glass ionomer filler in denture base resin

ObjectivesThis study investigated the influence of surface reaction-type prereacted glass ionomer (S-PRG) fillers on Candida albicans adhesion on denture base resin. MethodsDiscs were prepared by incorporating the S-PRG filler into the polymer powder of a polymethyl methacrylate (PMMA)-based, heat-polymerizing resin at 0 (control), 5%, 10%, and 20% (w/w). The surface roughness of all disc surfaces was measured. Elemental analysis of released Na+, Sr2+, SiO32−, Al3−, BO33−, and F− was performed after water immersion. Each disc was placed in a well with artificial saliva to form acquired pellicle, incubated, washed with phosphate-buffered saline, and immersed in a C. albicans (JCM2085) cell suspension standardized at 104 cells/ml. After aerobic incubation at 37°C for 24h, the metabolic mitochondrial activity, total biofilm biomass, and biofilm thickness were evaluated. The morphogenetic transition of C. albicans in the early culture stage (1 and 3h) was observed. ResultsThere was a slight but significant increase in the surface roughness with an increase in the filler content. The metabolic activity and total biomass volume were significantly lower in all filler groups than in the control group, although there were no significant differences among the filler groups. Groups with at least 5% filler content exhibited a thinner biofilm compared with the control group. All filler groups showed hyphal forms at 3h, with the length of the hyphae being lesser than those in the control group. ConclusionsAlthough the incorporation of S-PRG filler slightly increases the surface roughness of denture base resin, it reduces the adhesion of C. albicans. Clinical significanceThe S-PRG filler has the potential to reduce Candida albicans adhesion on denture base resin and may lower the risk of denture stomatitis. However, filler incorporation can increase the surface roughness of heat-polymerizing denture base resin.

Uptake of a fluorescent L-glucose derivative 2-NBDLG into three-dimensionally accumulating insulinoma cells in a phloretin-sensitive manner.

Of two stereoisomers of glucose, only d- and not l-glucose is abundantly found in nature, being utilized as an essential fuel by most organisms. The uptake of d-glucose into mammalian cells occurs through glucose transporters such as GLUTs, and this process has been effectively monitored by a fluorescent d-glucose derivative 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) at the single cell level. However, since fluorescence is an arbitrary measure, we have developed a fluorescent analog of l-glucose 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-l-glucose (2-NBDLG), as a negative control substrate for more accurately identifying the stereoselectivity of the uptake. Interestingly, a small portion of mouse insulinoma cells MIN6 abundantly took up 2-NBDLG at a late culture stage (≳10 days in vitro, DIV) when multi-cellular spheroids exhibiting heterogeneous nuclei were formed, whereas no such uptake was detected at an early culture stage (≲6 DIV). The 2-NBDLG uptake was persistently observed in the presence of a GLUT inhibitor cytochalasin B. Neither d- nor l-glucose in 50 mM abolished the uptake. No significant inhibition was detected by inactivating sodium/glucose cotransporters (SGLTs) with Na+-free condition. To our surprise, the 2-NBDLG uptake was totally inhibited by phloretin, a broad spectrum inhibitor against transporters/channels including GLUTs and aquaporins. From these, a question might be raised if non-GLUT/non-SGLT pathways participate in the 2-NBDLG uptake into spheroid-forming MIN6 insulinoma. It might also be worthwhile investigating whether 2-NBDLG can be used as a functional probe for detecting cancer, since the nuclear heterogeneity is among critical features of malignancy.Electronic supplementary materialThe online version of this article (doi:10.1007/s13577-015-0125-3) contains supplementary material, which is available to authorized users.

Evaluation of nutritional and environmental variables during early larval culture of pigfishOrthopristis chrysoptera(Linnaeus)

Pigfish (Orthopristis chrysoptera Linnaeus) are a commonly used baitfish in the southeastern United States. Aquaculture methods for broodfish spawning and juvenile grow-out have been developed but there is still a paucity of information regarding larval culture methods. Five, short duration (10 days) experiments were conducted to determine effective strategies to yield high larval survival and growth during early development. Experiment one examined the rotifer enrichments Ori-Green, DHA Protein Selco, and AlgaMac 3050 as well as a non-enriched control along with corresponding fatty acid levels in the enriched rotifers and pigfish larvae. Experiment two evaluated three, once daily feeding frequencies of either 5, 10 or 20 rotifers mL−1. Experiment three compared feeding 20 rotifers mL−1 once daily to feeding 5 rotifers mL−1 twice daily. Experiment four examined four different larval stocking densities: 50, 75, 100, or 125 larvae L−1. Experiment five examined green water strategies using either live Tahitian strain Isochrysis galbana (Parke) or Nannochloropsis oculata (Hibberd) paste at either 250 000 or 500 000 cells mL−1 as well as a clear water control. Results indicated rotifer enrichment with DHA Protein Selco and green water application using live T-ISO at 500 000 cells mL−1 had the highest survival of pigfish during early stages of larval culture. A once daily rotifer feeding regime of 20 rotifers mL−1 and stocking density of 50 larvae L−1 also improved survival. These results provide producers with methods to improve efficiency for pigfish larval culture and provide researchers with new foundational data, such as potential fatty acid requirements.

The effect of light-emitting diode irradiation at different wavelengths on calcification of osteoblast-like cells in 3D culture.

This study aimed to investigate the effect of four different light-emitting diode (LED) wavelengths on calcification and proliferation of osteoblast-like cells in vitro. MC3T3-E1 cells were seeded within three-dimensional collagen scaffolds and irradiated daily by LED light with peak emission wavelengths of 630-, 680-, 760- and 830-nm at constant fluency of 3.1 J/cm(2) (irradiance intensity 2 mW/cm(2)). Cultures were measured for calcium content at day 0, 7, 14, 21, 28, 35 and 42. The significant enhancement in calcium content was observed at the early stage of culture (days 7 and 14) (p<;0.05). After that, the calcium content of irradiated groups was similar to that of the controls group. This suggests the transient effect of light irradiation on osteoblastic cell calcification. Only 680-nm irradiated samples revealed a significant enhancement of calcium content until the late stages of culture (from days 21 to 42) (p<;0.001). The cyclin D mRNA expression that was investigated 3 hours after stimulation at day3 also show that the 680-nm LED irradiation can enhance cyclin D expression more than others. For enhancing bone mineralization, LED irradiation at the 680-nm is more effective than those at 630-, 760- and 830-nm. Further studies should be investigated in order to obtain the most effective parameters of LLLI on bone regeneration in clinical setting.

Effects of Temperature and Other Operational Parameters on Chlorella vulgaris Mass Cultivation in a Simple and Low-Cost Column Photobioreactor.

Mass production of microalgae worldwide, and even more so in developing countries, is strongly contingent upon the availability of economical and efficient photobioreactors (PBRs) that are amenable for use in resource-limited environments. Such options are limited. This work assesses the effects of temperature, CO2 enrichment, and mixing by air + CO2 bubbling on Chlorella vulgaris biomass production in a simple, low-cost 84-L column PBR. Cultivation at 25, 30, and 35 °C in a batch process showed that biomass production was negatively affected above 30 °C. Specific growth rates at each temperature were 0.75, 0.76, and 0.63 day(-1), respectively, with batch productivities of 70.50, 81.67, and 35.83 mg L(-1) day(-1). While a relatively low CO2/air ratio (1 %) seemed beneficial during the early stages of cultivation, higher concentrations were required to maintain growth rate and achieve higher biomass concentrations around 1000 mg L(-1). Cultivation with air + CO2 bubbling rates of 100, 200, and 400 L h(-1) led to specific growth rates (and batch productivities) of 0.64 day(-1) (59.58 mg L(-1) day(-1)), 0.74 day(-1) (81.67 mg L(-1) day(-1)), and 0.80 day(-1) (86.67 mg L(-1) day(-1)), respectively. The results indicate that high biomass productivities of C. vulgaris can be obtained up to 30 °C with moderate (2 %) to high (10 %) CO2 in a fairly simple PBR.

Effect of Carbohydrates on in vitro Shoot Growth of Various Prunus Species

Carbohydrate sources are one of important factors associated with macro- and micro nutrients and phytohormones in vitro culture medium for shoot growth. The optimal carbohydrates for eight species of the genus Prunus which are economically important fruit crop was evaluated at the initiation and elongation stages. All carbohydrate seemed utilized for the bud break and leaf growth at the early stage of culture. However, shoot elongation and fresh weight of species tested were superior in the medium containing 90 mM of fructose or glucose rather than sucrose. There was no difference between glucose and fructose. Adventitious shoots from the axillary buds were induced in most species but no significant differences were observed except for two species (P. salicina ‘Shiro’ and P. tomentosa). These result demonstrated that glucose and fructose were suitable carbohydrate sources for diverse Prunus species than sucrose, although the response to the carbohydrates in the medium were slightly different in the species.

Cell Viability, Mitotic Index and Callus Morphology of Byrsonima verbascifolia (Malpighiaceae)

The combined analysis of cell viability, mitotic index and callus morphology of species of commercial interest may favor the identification of cell masses with embryogenic characteristics at early stages of cultivation, allowing the development or improvement of protocols for in vitro plant regeneration through indirect embryogenesis. Byrsonima verbascifolia L. (DC.) (Malpighiaceae) is a Brazilian medicinal species native to the Cerrado, which has a low seed germination rate due to tegument dormancy. This study aimed to identify cells with embryogenic characteristics during growth of callus of B. verbascifolia, by assessing cell viability, mitotic index and cell morphology. Callus was induced from leaf explants and inoculated on MS medium with 4.52 μM 2,4-D and 4.44 μM benzylaminopurine (BAP). Friable calli were obtained at four distinct growth phases: lag (until the 30th), exponential (from 31st to the 70th day), linear (from 71st to the 100th day) and decline (from 101st to the 120th day). Calli with 20 and 30 days showed cells with embryogenic characteristics, that is, isodiametric shape, juxtaposed, with small vacuoles, thin cell wall and presence of amyloplasts. After 120 days, calli were mostly elongated cells with lower cell viability and mitotic index.

HORN FIGURINES FROM AN OKUNEV BURIAL ON LAKE ITKUL, KHAKASSIA, SOUTHERN SIBERIA

Eight miniature horn figurines representing human-like characters and heads of birds, elk, boar, and a carnivore, were found in grave 4 at Itkol II mound 14, northern Minusinsk Basin. The burial dates to the early (Uybat) stage of the Okunev culture (second half of the 3rd millennium BC). The form and composition of certain figurines resemble those of Okunev steles.

Short-term effects of calcium ions on the apoptosis and onset of mineralization of human dental pulp cells in vitro and in vivo.

Calcium ions (Ca2+) are a major constituent of most pulp-capping materials and have an important role in the mineralization of human dental pulp cells (hDPCs). A previous study by our group has shown that increased levels of Ca2+ can promote hDPC-mediated mineralization in long-term cultures (21 days). However, the initiation of mineralization occurs in the early stage of osteogenic inductive culture, and the effects of Ca2+ on the mineralization of hDPCs in short-term cultures (five days) have not been studied in detail. Furthermore, the underlying mechanism by which Ca2+ stimulates the mineralization of hDPCs has remained controversial. A strong correlation between mineralization and cell apoptosis and/or death has been identified. Thus, the present study hypothesized that Ca2+ may promote the onset of hDPC-mediated mineralization through inducing their apoptosis and/or death. To verify this hypothesis, Ca2+ was added to the growth culture medium and osteogenic culture medium at various concentrations. Alizarin Red S staining and reverse transcription-polymerase chain reaction analysis were used to evaluate the onset of mineralization. Furthermore, the cell counting kit-8 and fluorescein isothiocyanate-Annexin V/propidium iodide double-staining method were adopted to detect the proliferation and apoptosis of hDPCs in the growth culture medium. An animal experiment and scanning electron microscopic observation of ceramic graft implants were applied to measure the mineralization in vivo. The results showed that 5.4 and 9.0 mM Ca2+ accelerated the onset of mineralized matrix nodule formation, promoted osteopontin mRNA expression and induced marked cell apoptosis and necrosis, but had no obvious effect on cell proliferation. These findings indicated a positive association between cell apoptosis and/or death and the timing of formation as well as the quantity of extracellular mineralization induced by Ca2+ in short-term cultured hDPCs.

Transcriptional Dynamics of Immortalized Human Mesenchymal Stem Cells during Transformation.

Comprehensive analysis of alterations in gene expression along with neoplastic transformation in human cells provides valuable information about the molecular mechanisms underlying transformation. To further address these questions, we performed whole transcriptome analysis to the human mesenchymal stem cell line, UE6E7T-3, which was immortalized with hTERT and human papillomavirus type 16 E6/E7 genes, in association with progress of transformation in these cells. At early stages of culture, UE6E7T-3 cells preferentially lost one copy of chromosome 13, as previously described; in addition, tumor suppressor genes, DNA repair genes, and apoptosis-activating genes were overexpressed. After the loss of chromosome 13, additional aneuploidy and genetic alterations that drove progressive transformation, were observed. At this stage, the cell line expressed oncogenes as well as genes related to anti-apoptotic functions, cell-cycle progression, and chromosome instability (CIN); these pro-tumorigenic changes were concomitant with a decrease in tumor suppressor gene expression. At later stages after prolong culture, the cells exhibited chromosome translocations, acquired anchorage-independent growth and tumorigenicity in nude mice, (sarcoma) and exhibited increased expression of genes encoding growth factor and DNA repair genes, and decreased expression of adhesion genes. In particular, glypican-5 (GPC5), which encodes a cell-surface proteoglycan that might be a biomarker for sarcoma, was expressed at high levels in association with transformation. Patched (Ptc1), the cell surface receptor for hedgehog (Hh) signaling, was also significantly overexpressed and co-localized with GPC5. Knockdown of GPC5 expression decreased cell proliferation, suggesting that it plays a key role in growth in U3-DT cells (transformants derived from UE6E7T-3 cells) through the Hh signaling pathway. Thus, the UE6E7T-3 cell culture model is a useful tool for assessing the functional contribution of genes showed by expression profiling to the neoplastic transformation of human fibroblasts and human mesenchymal stem cells (hMSC).

The Application of Dielectric Spectroscopy and Biocalorimetry for the Monitoring of Biomass in Immobilized Mammalian Cell Cultures

The purpose of this study was to introduce dielectric spectroscopy and biocalorimetry as monitoring methods to follow immobilised Chinese Hamster Ovary (CHO) cell culture development. The theory behind both monitoring techniques is explained and perfusion cultures are performed in a Reaction Calorimeter (eRC1 from Mettler Toledo) as an application example. The findings of this work show that dielectric spectroscopy gives highly reliable information upon the viable cell density throughout the entire culture. On the other hand, the RC1 could only provide accurate data from day 5, when the cell density exceeded 4 × 106 vcells∙mL−1 (viable cell per mL) working volume (WV). The method validation showed the limit of detection (LOD) for 1.4 L cultures to be 8.86 × 106 vcells∙mL−1, a viable cell density commonly achieved in fed-batch and the early stages of a perfusion culture. This work suggests that biocalorimetry should be possible to implement at industrial scale to monitor CHO cell cultures.

Proliferation rates of bovine primary muscle cells relate to liveweight and carcase weight in cattle.

Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM) of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5–20 hours in culture) in vitro (P < 0.05). The proliferation rates of myoblasts during early stages of culture in vitro were also found to be positively related to the liveweight and carcase weight of cattle (P < 0.05). Gene expression of MYF5 was also found to be significantly down-regulated in WagyuX compared with Angus cattle (P < 0.05). These findings suggest that early events during myogenesis are important for determining liveweight and caracase weights in cattle.

Mentesh Tepe, an early settlement of the Shomu-Shulaveri Culture in Azerbaijan

Excavations at Mentesh Tepe, western Azerbaijan, have unearthed Neolithic levels dated to an early stage of the Shomu-Shulaveri Culture, with a specific material culture and several inhumations among which a multiple burial. At that stage, already a full domestication of plants and animals is evident. Many questions have been raised concerning the origins of this culture, and its end is also still obscure. Relations with societies in the north-Mesopotamian area have again recently been evidenced at its beginnings. Mentesh Tepe, with its exceptional succession of occupations from the Neolithic to the Early Bronze Age, could help providing some clues for the links between the Neolithic and the Chalcolithic periods. The site is presented here under different points of views (architecture, burials, material culture) but in a preliminary stage since many studies are still in progress. Questions are raised about the climate and the apparent absence of pre- and post-Shomu-Shulaveri Culture possibly due to silting or erosion processes linked with the mobility of the Caspian Sea level.

The effects of different night-time temperatures and cultivation durations on the polyphenolic contents of lettuce: Application of principal component analysis

The present study was conducted to characterize the polyphenolic contents of lettuce leaves grown under different night-time temperatures (4, 12, and 20°C) and cultivation durations (5, 15, and 20days) using high performance liquid chromatography-tandem mass spectrometry (LC/MS/MS). The assay method was validated based on specificity, linearity, accuracy, precision, and the performance limit. The total polyphenolic contents were highest (2462.6mg/kg) after transplantation at a night temperature of 20°C on day 20 and lowest (1132.7mg/kg) at the same temperature on day 5. Quantification and principal component analysis showed that the relative contents of quercetin and kaempferol were markedly higher during the early stage of cultivation (day 5) than those of day 15 and 20, and that night-time temperatures of 12 and 20°C on day 20 were favorable for producing polyphenol-rich lettuce containing caffeic acid. In conclusion, a synergistic effect between high night-time temperatures (12 and 20°C) and cultivation duration (20days) produced lettuce rich in polyphenols compared to that at low temperature (4°C).

Investigating the biological response of human mesenchymal stem cells to titanium surfaces.

BackgroundWe have investigated the behaviour of a newly characterised population of haemarthrosis fluid-derived human mesenchymal stem cells (HF-hMSCs) with titanium (Ti) surfaces.MethodsHF-hMSCs were seeded onto round cannulated interference (RCI; Smith and Nephew) screws or control Ti discs and cultured under pro-osteogenic conditions.ResultsElectron microscopy showed the attachment and spreading of HF-hMSCs across both Ti surfaces during the early stages of osteogenic culture; however, cells were exclusively localised to the basal regions within the vertex of the Ti screws. In the later stages of culture, an osteoid matrix was deposited on the Ti surfaces with progressive culture expansion and matrix deposition up the sides and the top of the Ti Screws. Quantification of cellular content revealed a significantly higher number of cells within the Ti screw cultures; however, there was no difference in the cellular health. Conversely, alizarin red staining used as both a qualitative and quantitative measure of matrix calcification was significantly increased in Ti disc cultures compared to those of Ti screws.ConclusionsOur results suggest that the gross topography of the metal implant is able to create microenvironment niches that have an influence on cellular behaviour. These results have implications for the design of advanced tissue engineering strategies that seek to use cellular material to enhance biological remodelling and healing following tissue reconstruction.

Hyperbaric oxygen therapy accelerates osteoblast differentiation and promotes bone formation

ObjectivesHyperbaric oxygen therapy (HBO) has been used as an adjunctive therapy in the treatment of radiotherapy or bisphosphonate-induced osteonecrosis of the jaw however the effect of HBO on osteoblast formation and mineralisation has not been extensively studied. The current study therefore examined the effects of HBO, elevated pressure or elevated oxygen alone on osteoblast differentiation and bone nodule formation. MethodsSaos-2 human osteoblast cells were exposed to HBO (2.4 ATA, 97.9% O2, 90min per day), elevated pressure alone (2.4 ATA, 8.8% O2, 90min per day) or elevated oxygen alone (1 ATA, 95% O2, 90min per day) after culturing under normoxic or hypoxic conditions and osteoblast differentiation and bone formation assessed by alkaline phosphatase activity and calcein incorporation. Expression of key regulators of osteoblast differentiation and bone matrix proteins were assessed by quantitative PCR. ResultsDaily exposure to HBO accelerated the rate of osteoblast differentiation as determined by increased alkaline phosphatase activity and expression of type I collagen and Runx-2 mRNA during the early stages of culture. HBO also augmented bone nodule formation in hypoxic conditions. HBO had a more pronounced effect on these key markers of osteoblast differentiation than elevated oxygen or pressure alone. ConclusionsThe data from this study shows that daily HBO treatment accelerated the rate of osteoblast differentiation leading to an increase in bone formation. Clinical significanceThese studies add to our understanding of HBO's reparative action in osteonecrotic bone loss. In addition to stimulating angiogenesis HBO may also improve surgical outcomes through a direct beneficial effect on osteoblast differentiation generating a larger bone mass available for reconstruction.

Hyperspectral imaging techniques for the characterization of Haematococcus pluvialis (Chlorophyceae).

A hyperspectral imaging camera was combined with a bright-field microscope to investigate the intracellular distribution of pigments in cells of the green microalga Haematococcus pluvialis, a synonym for H.lacustris (Chlorophyceae). We applied multivariate curve resolution to the hyperspectral image data to estimate the pigment contents in culture and revealed that the predicted values were consistent with actual measurements obtained from extracted pigments. Because it was possible to estimate pigment contents in every pixel, the intracellular distribution of the pigments was investigated during various life-cycle stages. Astaxanthin was localized specifically at the eyespot of zoospores in early culture stages. Then, it became widely distributed in cells, but subsequently localized differently than the chl. Integrated with our recently developed image-processing program "HaematoCalMorph," the hyperspectral imaging system was useful for monitoring intracellular distributions of pigments during culture as well as for studying cellular responses under various conditions.