Regrowth potential of shoot and of roots of Rhodes grass (Chloris gayana Kunth) after defoliation.

In field and pot trials the effect of different lengths of pre-cutting periods and of cutting intervals on regrowth of shoot and of root were studied in Rhodes grass cv. Katambora. The initial regrowth of the sward after a long (28 days) pre-cutting period was slower than after a short (7 days) pre-cutting period. The reduction of the residual LAI following the extension of the pre-cutting period was associated with reduction in the number of tillers capable of regrowth after defoliation. Root wt. decreased drastically following cutting when the initial root wt. was high (long pre-cutting period), but little when the initial root wt. was small (short pre-cutting period). The decrease in root wt. lasted c. 1 wk after which it increased at a more or less constant rate proportional to the increase of shoot wt. irrespective of the length of the pre-cutting period. The lack of the capability of tillers to regrow after cutting was closely related with developmental stage of tillers. Since tillers of subtropical and tropical grasses have a tendency for early stem elongation, it was concluded that the relatively small number of sites available for regrowth in these grasses is the major deterrent for quick shoot growth of the sward after defoliation. (Abstract retrieved from CAB Abstracts by CABI’s permission

Pathogenesis of bovine spongiform encephalopathy in sheep

The pathogenesis of bovine spongiform encephalopathy (BSE) in sheep was studied by immunohistochemical detection of scrapie-associated prion protein (PrPSc) in the gastrointestinal, lymphoid and neural tissues following oral inoculation with BSE brain homogenate. First accumulation of PrPSc was detected after 6 months in the tonsil and the ileal Peyer’s patches. At 9 months postinfection, PrPSc accumulation involved all gut-associated lymphoid tissues and lymph nodes as well as the spleen. At this time point, PrPSc accumulation in the peripheral neural tissues was first seen in the enteric nervous system of the caudal jejunum and ileum and in the coeliac-mesenteric ganglion. In the central nervous system, PrPSc was first detected in the dorsal motor nucleus of the nervus Vagus in the medulla oblongata and in the intermediolateral column in the spinal cord segments T7–L1. At subsequent time points, PrPSc was seen to spread within the lymphoid system to also involve all non-gut-associated lymphoid tissues. In the enteric nervous system, further spread of PrPSc involved the neural plexi along the entire gastrointestinal tract and in the CNS the complete neuraxis. These findings indicate a spread of the BSE agent in sheep from the enteric nervous system through parasympathetic and sympathetic nerves to the medulla oblongata and the spinal cord

Ю.О. Митропольський — вчений та вихователь молоді

Висвітлено наукову діяльність та роботу з підготовки наукових кадрів академіка Ю.О. Митропольського. Змальовано його риси як вченого та вихователя молоді.Освещены научная деятельность и работа по подготовке научных кадров академика Ю.А.Митропольского. Обрисованы его черты как ученого и воспитателя молодежи.The paper highlights research and tutorial activities by Academician Yu.O. Mitropolsky. His qualities as a scientist and a tutor of youth are outlined

Variability in disease phenotypes within a single PRNP genotype suggests the existence of multiple natural sheep scarpie strains within Europe

Variability of pathological phenotypes within classical sheep scrapie cases has been reported for some time, but in many instances it has been attributed to differences in the PRNP genotype of the host. To address this issue we have examined by immunohistochemistry (IHC) and Western blotting (WB) for the disease-associated form of the prion protein (PrPd), the brains of 23 sheep from five European countries, all of which were of the same ARQ/ARQ genotype. As a result of IHC examinations, sheep were distributed into five groups with different phenotypes and the groups were the same regardless of the scoring method used, ‘long’ or ‘short’ PrPd profiling. The groups made did not respond to the geographical origin of the cases and did not correlate with the vacuolar lesion profiles, which showed a high individual variability. Discriminatory IHC and WB methods coincided to detect a ‘CH1641-like’ case but otherwise correlated poorly in the classification of disease phenotypes. No other polymorphisms of the PRNP gene were found that could account for the pathological differences, except perhaps for a sheep from Spain with a mutation at codon 103 and a unique pathological phenotype. Preliminary evidence indicates that those different IHC phenotypes correlate with distinct biological properties on bioassay, suggesting that they are indicative of strain diversity. We therefore conclude that natural scrapie strains exist and that they can be revealed by detailed pathological examinations, which can be harmonized between laboratories to produce comparable results

Transcriptomic and proteomic profiling of maize embryos exposed to camptothecin

<p>Abstract</p> <p>Background</p> <p>Camptothecin is a plant alkaloid that specifically binds topoisomerase I, inhibiting its activity and inducing double stranded breaks in DNA, activating the cell responses to DNA damage and, in response to severe treatments, triggering cell death.</p> <p>Results</p> <p>Comparative transcriptomic and proteomic analyses of maize embryos that had been exposed to camptothecin were conducted. Under the conditions used in this study, camptothecin did not induce extensive degradation in the genomic DNA but induced the transcription of genes involved in DNA repair and repressed genes involved in cell division. Camptothecin also affected the accumulation of several proteins involved in the stress response and induced the activity of certain calcium-dependent nucleases. We also detected changes in the expression and accumulation of different genes and proteins involved in post-translational regulatory processes.</p> <p>Conclusions</p> <p>This study identified several genes and proteins that participate in DNA damage responses in plants. Some of them may be involved in general responses to stress, but others are candidate genes for specific involvement in DNA repair. Our results open a number of new avenues for researching and improving plant resistance to DNA injury.</p

Cost-effectiveness of tailored print communication, telephone motivational interviewing, and a combination of the two: results of an economic evaluation alongside the Vitalum randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to evaluate the cost-effectiveness of tailored print communication (TPC), telephone motivational interviewing (TMI), a combination of the two, and no intervention on two outcomes in adults aged 45 to 70, half of them having hypertension: increasing the number of public health guidelines met for three behaviors (physical activity and fruit and vegetable consumption), and impact on quality adjusted life years (QALYs).</p> <p>Methods</p> <p>Participants (<it>n </it>= 1,629) from 23 Dutch general practices were randomized into one of four groups, which received 4 TPCs, 4 TMIs, 2 of each (combined), or no intervention (control), respectively. The self-reported outcomes, measured at baseline and 73 weeks follow-up (7 months after the last intervention component), were difference in total number of guidelines met at follow-up compared to baseline, and number of QALYs experienced over 73 weeks. The costs of implementing the intervention were estimated using a bottom-up approach.</p> <p>Results</p> <p>At 73 weeks follow-up participants showed increased adherence with 0.62 (TPC), 0.40 (TMI), 0.50 (combined), and 0.26 (control) guidelines compared to baseline, and experienced 1.09, 1.08, 1.08, and 1.07 QALYs, respectively. The costs for the control group were considered to be zero. TMI was more expensive (€107 per person) than both the combined intervention (€80) and TPC (€57). The control condition was most cost-effective for lower ceiling ratios, while TPC had the highest probability of being most cost-effective for higher ceiling ratios (more than €160 per additional guideline met, and €2,851 for each individual QALY).</p> <p>Conclusions</p> <p>For low society's willingness to pay, the control group was most cost-effective for the number of QALYs experienced over 73 weeks. This also applied to the increase in the number of guidelines met at lower ceiling ratios, whereas at higher ceiling ratios, TPC had a higher probability of being more cost-effective than the TMI, combined or control conditions. This also seemed to apply for QALYs experienced over 73 weeks. More research is needed on the long-term efficacy of both TPC and TMI, as well as on how to increase their cost-effectiveness.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR1068</p