Effects of Lactobacillus helveticus fermented milk on bone cells in vitro

Milk fermented with Lactobacillus helveticus (L. helveticus) contains small peptides such as isoleucyl-prolyl-proline (IPP) and valyl-prolyl-proline (VPP), which inhibit the angiotensin converting enzyme (ACE). We investigated the effects of L. helveticus fermented milk whey (Lh-whey) and its components, sour milk whey, calcium and IPP and VPP peptides, on bone cells in vitro. An osteoblast assay was performed by determining the amount of deposited calcium as an index of bone formation in cultures of mouse osteoblasts formed from bone marrow-derived osteoblast precursor cells. An osteoclast assay was performed by determining the activity of tartrate-resistant acid phosphatase released into the culture medium in cultures of mouse osteoclasts formed from bone marrow-derived osteoclast precursor cells. The Lh-whey increased bone formation 1.3-1.4 times with the 1 × 10⁻⁵, 1 × 10⁻⁴ and 1 × 10⁻³ solutions. The IPP and VPP peptides also demonstrated a significant 5-fold activation of bone formation in in vitro osteoblast cultures, whereas the sour milk whey and calcium had no effect. No significant effects were observed on osteoclasts in vitro with any of the study products. L. helveticus fermented milk whey contains bioactive components that increase osteoblastic bone formation in vitro. The effect may be due to the ACE-inhibitory IPP and VPP peptides, which showed a similar effect to that of the L. helveticus fermented milk whey.     

Solar UV-B radiation affects leaf quality and insect herbivory in the southern beech tree<Emphasis Type="Italic"> Nothofagus antarctica</Emphasis>

We examined the effects of solar ultraviolet-B (UV-B) radiation on plant-insect interactions in Tierra del Fuego (55°S), Argentina, an area strongly affected by ozone depletion because of its proximity to Antarctica. Solar UV-B under Nothofagus antarctica branches was manipulated using a polyester plastic film to attenuate UV-B (uvb–) and an Aclar film to provide near-ambient UV-B (uvb+). The plastic films were placed on both north-facing (i.e., high solar radiation in the Southern Hemisphere) and south-facing branches. Insects consumed 40% less leaf area from north- than from south-facing branches, and at least 30% less area from uvb+ branches than from uvb– branches. The reduced herbivory on leaves from uvb+ branches occurred for both branch orientations. Leaf mass per area increased and relative water content decreased on north- versus south-facing branches, while no differences were apparent between the UV-B treatments. Solar UV-B did lead to lower gallic acid concentration and higher flavonoid aglycone concentration in uvb+ leaves relative to uvb– leaves. Both the flavonoid aglycone and quercetin-3-arabinopyranoside were higher on north-facing branches. In laboratory preference experiments, larvae of the dominant insect in the natural community, Geometridae Brown (Lepidoptera), consumed less area from field-grown uvb+ leaves than from uvb– leaves in 1996–97, but not in 1997–98. Correlation analyses suggested that the reduction in insect herbivory in the field under solar UV-B may be mediated in part by the UV-B effects on gallic acid and flavonoid aglycone.     

Detection of sequence polymorphisms in red junglefowl and White Leghorn ESTs

Over 16,000 high quality expressed sequence tags (ESTs) from red junglefowl (RJ) and White Leghorn (WL) brain and testis cDNA libraries were generated. Here, we have used this resource for detection of single nucleotide polymorphisms (SNPs), and also completed full-length sequencing of 46 pairs of clones, representing the same gene from both the RJ and WL libraries. From the main set of ESTs, which were assembled using Phrap, 746 putative SNPs were identified, of which 76% were transitions and 24% were transversions. A subset of SNPs was evaluated by sequence analysis of five RJ and five WL birds. Nine of 12 SNPs were verified in this limited sample, suggesting that a majority of the putative polymorphisms documented in this study represent real SNPs. During full-length sequencing of the 46 RJ/WL clones 100 SNPs were identified, which translated to a frequency of 1.90 SNPs/1000 bp. The number of transitions and transversions were 77% and 23%, respectively, and the proportion of non-synonymous vs. synonymous SNPs was 20% and 80%, respectively. Four large insertions/deletions were identified between the RJ and WL full-length sequences, and they appear to represent different splice variants.     

Building supertrees: an empirical assessment using the grass family (Poaceae)

Large and comprehensive phylogenetic trees are desirable for studying macroevolutionary processes and for classification purposes. Such trees can be obtained in two different ways. Either the widest possible range of taxa can be sampled and used in a phylogenetic analysis to produce a "big tree," or preexisting topologies can be used to create a supertree. Although large multigene analyses are often favored, combinable data are not always available, and supertrees offer a suitable solution. The most commonly used method of supertree reconstruction, matrix representation with parsimony (MRP), is presented here. We used a combined data set for the Poaceae to (1) assess the differences between an approach that uses combined data and one that uses different MRP modifications based on the character partitions and (2) investigate the advantages and disadvantages of these modifications. Baum and Ragan and Purvis modifications gave similar results. Incorporating bootstrap support associated with pre-existing topologies improved Baum and Ragan modification and its similarity with a combined analysis. Finally, we used the supertree reconstruction approach on 55 published phylogenies to build one of most comprehensive phylogenetic trees published for the grass family including 403 taxa and discuss its strengths and weaknesses in relation to other published hypotheses.     

Does nitrogen fertilization have an impact on the trade-off between willow growth and defensive secondary metabolism?

The effect of nitrogen fertilization on the phytomass production, shoot length and leaf secondary phenolics in nine Salix myrsinifolia clones was investigated. Cuttings taken from 1-year-old and 2-year-old shoot parts of field cultivated clones were grown at three concentrations of nitrogen (7, 150 and 300 ppm) in a greenhouse for one growing season. The willow clones differed significantly in phytomass yield and secondary phenolics content. Nitrogen fertilization affected significantly the growth and secondary metabolism of willow clones. In most clones, the addition of nitrogen from a sub-optimum concentration (7 ppm) to an optimum concentration (150 ppm) appeared to reduce the amounts of salicortin, chlorogenic acid and unknown salicylate and increased shoot phytomass, but a supraoptimum nitrogen concentration (300 ppm) resulted in highly variable growth and secondary phenolic responses. A significantly negative correlation between leaf phytomass and amount of total phenolics at sub-optimum and optimum N-treatments indicates trade-off between growth and secondary metabolism in willow clones at these treatments. However, the leaf phytomass:total amount of phenolics ratio varied significantly among clones, and in all clones it was not significantly lower at sub-optimum N-treatment than at optimum N-treatment.     

Secretion of a heat-stable fungalβ-glucanase from transgenic,suspension-cultured barley cells

Transgenic plant cell cultures have a potential for production and secretion of important proteins and peptides. To assess the possibilities of using a stable barley suspension culture for secretion of heterologous proteins in active form, we expressed the cDNA of the thermostable-glucanase (EGI) ofTrichoderma reesei in barley suspension cells. The cDNA coding for EGI and its signal sequence was placed under the control of the CaMV 35S promoter and the construction was transferred to the cells by particle bombardment. Stably transformed lines were obtained by selecting for a cotransformed antibiotic resistance marker. The expression of EGI cDNA led to accumulation of EGI in the culture medium, as shown by analysis with EGI-specific antibodies. Enzymatic assays confirmed that the EGI secreted by the suspension cells retained its activity and thermostable character. Furthermore, it was shown that the enzyme produced by the transgenic suspension culture could be used for degradation of soluble-glucans during mashing.     

Water chemistry of Lake Ladoga and Russian-Finnish intercalibration of analyses

As part of the Russian-Finnish research studies on Lake Ladoga, joint expeditions were organized in 1992 and 1993. Water samples were collected for intercalibration of chemical analysis methods and to monitor the chemical quality of the lake water.In August of 1992 water samples were taken from northern Lake Ladoga for intercalibration of Russian and Finnish analysis methods. In August 1993 water samples were collected from 23 sampling stations in all parts of the lake; some of these were also used for intercalibration purposes.The oxygen, colour and COD_Mn results were at the same level in the intercalibration. In 1993, the P_tot results obtained were acceptable. In N_tot, Fe and Mn analysis there seemed to be systematic and random errors between some results.The Secchi depth ranged from 1.5 m to 3.3 m. The average concentrations for the total phosphorus ranged from 15 µg 1^–1 to 29 µg 1^–1. The total nitrogen values were from 620 µg 1^–1 to 690 µg 1^–1. The N:P ratio varied from 24 to 40. The concentration of phosphorus indicated mesotrophic or even eutrophic conditions in the lake. Phosphorus seemed to be the limiting nutrient to bacteria and algae.     

All-trans retinoic acid induces apoptosis in acute myeloblastic leukaemia cells

The effect of all-trans retinoic acid (ATRA) on leukaemia cell differentiation, proliferation and induction of apoptosis was studied by using autonomously growing blast cells isolated from eight patients with acute myeloblastic leukaemia (AML) either at diagnosis ( n=4) or at relapse (n=4). No morphological or functional differentiation induced by ATRA was observed in any of the cases studied. In cell cultures, inhibition of leukaemia cell growth by ATRA was obvious, especially in the case of clonogenic cells, and it was both time- and concentration-dependent. Induction of apoptosis was more difficult to achieve. The cells retained over 90% viability in suspension when the ATRA exposure at any of the concentrations studied was 48 h or less. When the time of exposure to ATRA was longer than 48 h, the viability of the cells decreased in a concentration-dependent manner. Apoptosis was observed morphologically in each of the AML cases with 10-5 to 10-8 M ATRA, if the incubation time of cells in ATRA was 72 h. The percentage of apoptotic cells increased with increasing ATRA concentrations from 12± 9% of 10-8 M ATRA to 78±12% of 10-5 M ATRA. The DNA electrophoretic method was able to detect apoptosis in all the AML samples exposed to 10-7 and 10-6 ATRA for 48 h and occasionally in cases where lower concentrations and longer exposure time were used. In conclusion, the present study shows that it is possible to induce apoptotic leukaemia cell death in vitro with ATRA in AML, and this effect is dependent on both concentration and exposure time.     

Fertile transgenic barley by particle bombardment of immature embryos

Transgenic, fertile barley (Hordeum vulgare L.) from the Finnish elite cultivar Kymppi was obtained by particle bombardment of immature embryos. Immature embryos were bombarded to the embryonic axis side and grown to plants without selection. Neomycin phosphotransferase II (NPTII) activity was screened in small plantlets. One out of a total of 227 plants expressed the transferred nptII gene. This plant has until now produced 98 fertile spikes (T₀), and four of the 90 T₀ spikes analyzed to date contained the nptII gene. These shoots were further analyzed and they expressed the transferred gene. From green grains, embryos were isolated and grown to plantlets (T₁). The four transgenic shoots of Toivo (the T₀ plant) produced 25 plantlets as T₁ progeny. Altogether fifteen of these T₁ plants carried the transferred nptII gene as detected with the PCR technique, fourteen of which expressed the nptII gene. The integration and inheritance of the transferred nptII gene was confirmed by Southern blot hybridization. Although present as several copies, the transferred gene was inherited as a single Mendelian locus into the T₂ progeny.