Background processes at the population level during succession in grasslands on sand

Two population characteristics, reproductive allocation (RA) and the intensity of photosynthesis, were investigated in the successional stages of the sandy grassland communities of the Great Hungarian Plain. Most of the species studied changed their allocational response as succession advanced. Compound path schemes, as casual models, were constructed and analysed for describing intra-individual effects (influence of assimilating organs and root mass of the plant sampled) as well as the phytosociological effects on RA. In pioneer stages, the high values of path coefficients show that the effect of assimilating organs is responsible for the variability of RA. It is also shown that annuals and perennials exhibit different behaviour as to the regulation of RA. It seems that-in terms of path analysis-the reproduction of annuals is influenced by internal factors only. In case of perennials, an external (namely phytosociological) regulation was also observed. It is suggested that successional stages play a role in regulating the photosynthetic intensity of both the dominant species and the whole plant assemblage.Abbreviations RA = Reproductive Allocation     

The hazards of DAPI photoconversion: effects of dye, mounting media and fixative, and how to minimize the problem

Immunocytochemistry is a powerful tool for detection and visualization of specific molecules in living or fixed cells, their localization and their relative abundance. One of the most commonly used fluorescent DNA dyes in immunocytochemistry applications is 4′,6-diamidino-2-phenylindole dihydrochloride, known as DAPI. DAPI binds strongly to DNA and is used extensively for visualizing cell nuclei. It is excited by UV light and emits characteristic blue fluorescence. Here, we report a phenomenon based on an apparent photoconversion of DAPI that results in detection of a DAPI signal using a standard filter set for detection of green emission due to blue excitation. When a sample stained with DAPI only was first imaged with the green filter set (FITC/GFP), only a weak cytoplasmic autofluorescence was observed. Next, we imaged the sample with a DAPI filter set, obtaining a strong nuclear DAPI signal as expected. Upon reimaging the same samples with a FITC/GFP filter set, robust nuclear fluorescence was observed. We conclude that excitation with UV results in a photoconversion of DAPI that leads to detection of DAPI due to excitation and emission in the FITC/GFP channel. This phenomenon can affect data interpretation and lead to false-positive results when used together with fluorochrome-labeled nuclear proteins detected with blue excitation and green emission. In order to avoid misinterpretations, extra precaution should be taken to prepare staining solutions with low DAPI concentration and DAPI (UV excitation) images should be acquired after all other higher wavelength images. Of various DNA dyes tested, Hoechst 33342 exhibited the lowest photoconversion while that for DAPI and Hoechst 33258 was much stronger. Different fixation methods did not substantially affect the strength of photoconversion. We also suggest avoiding the use of mounting medium with high glycerol concentrations since glycerol showed the strongest impact on photoconversion. This photoconversion effect cannot be avoided even when using narrow bandpass filter sets.     

Diagnosis and phylogenetic analysis of orf virus in Aleppo and Saanen goats from an outbreak in Turkey

正Dear Editor,The Poxviridae family is divided into Chordopoxvirinae and Entomopoxvirinae genera.Parapoxvirus is one of 11genera in the Chordopoxvirinae genus,including orf virus(ORFV),bovine papular stomatitis virus(BPSV),pseudocowpox virus(PCPV)and parapoxvirus of red deer in New Zealand(PVNZ)(Skinner et al.,2012).This virus,also known as contagious ecthyma or contagious pustular dermatitis,is a viral skin disease causing edematous proliferative lesions,most often in hairless skin     

Low‐dose bisphenol A induces RIPK1‐mediated necroptosis in SH‐SY5Y cells: Effects on TNF‐α and acetylcholinesterase

Bisphenol A (BPA) is an endocrine disruptor chemical, which is commonly used in everyday products. Adverse effects of its exposure are reported even at picomolar doses. Effects of picomolar and nanomolar concentrations of BPA on cytotoxicity, nitric oxide (NO) levels, acetylcholinesterase (AChE) gene expression and activity, and tumor necrosis factor‐α (TNF‐α) and caspase‐8 levels were determined in SH‐SY5Y cells. The current study reveals that low‐dose BPA treatment induced cytotoxicity, NO, and caspase‐8 levels in SH‐SY5Y cells. We also evaluated the mechanism underlying BPA‐induced cell death. Ours is the first report that receptor‐interacting serine/threonine‐protein kinase 1–mediated necroptosis is induced by nanomolar BPA treatment in SH‐SY5Y cells. This effect is mediated by altered AChE and decreased TNF‐α levels, which result in an apoptosis‐necroptosis switch. Moreover, our study reveals that BPA is an activator of AChE.     

Screening of Y chromosome microdeletion which contains AZF regions in 71 Turkish azoospermic men

Screening of Y chromosome microdeletion which contains AZF regions in 71 turkish azoospermic men: In 71 Turkish men Y chromosome microdeletions have been studied before intracytoplasmic sperm injection (ICSI). DNA samples were amplified with 18 STS primers of the azoospermia factor (AZF) region on the Y chromosome by using multiplex polymerase chain reaction (PCR). Microdeletions were detected in 4 azoospermic men (5.6 %); one with a deletion in the AZFb region, while the 3 others had a large deletion extending over multiple chromosomal regions (AZFb+c+d and AZFa+b+c+d). In the patients with microdeletion, no spermatogenetic activity could be detected in testis biopsies. This result confirms the idea that Y chromosome microdeletion analysis is important in investigating the possibility of finding sperm in testicular sperm extraction (TESE). Therefore, we point out the importance of genetic testing and counselling regarding Y chromosome microdeletion for couples requesting ICSI.     

Evaluation of the immune response to hepatitis B vaccination in children aged 1-3 years in Malatya, Turkey

By the end of 1998, Turkey had launched the routine vaccination of infants against hepatitis B. The purpose of the study is to evaluate the immune response in a sample of vaccinated children aged 1-3 years in the city of Malatya. A total of 210 vaccinated children 12 to 48 months old were selected for the study with 30 cluster sampling in the city of Malatya, Turkey. The children were visited at their homes during January-April 2002. The information on demographic characteristics, family's and child's medical history was gathered, childrens' weight and height were measured and blood samples were taken. Anti-HBs, HbsAg and anti-HBc titers were assayed by micro-ELIZA from the sera. The mean age of the children was 26.3 months, 100 (47.6%) were male and 110 (52.4%) were female. Overall, 203 (96.7%) children had protective anti-HBs levels (> or = 10 IU/l), 0.5% showed evidence of natural infection (with positive anti-HBc and anti-HBs titers), 0.5% had acute or chronic infection (with positive HbsAg and anti-HBc titers) and 2.3% were seronegative. Geometric mean titer of anti-HBs among vaccinated children except those who had positive anti-HBc titers was 138.7 mIU/ml (95% CI:124.7-154.2) and seroconversion rates did not differ by age, sex, anthropometric measurements, time after third dose and place of vaccine administered (P > 0.05). The high seroprotection rate over 95% showed that routine infant vaccination program for hepatitis B was successfully carried out in the city Malatya.     

ABA treatment increases both the desiccation tolerance of photosynthesis,and nonphotochemical quenching in the moss Atrichum undulatum

Pulse amplitude modulation fluorescence was used to investigate whether abscisic acid (ABA) pretreatment increases the desiccation tolerance of photosynthesis in the moss Atrichum undulatum. In unstressed plants, ABA pretreatment decreased the F _V/F _m ratio, largely as a result of an increase in F _o. This indicated a reduction in energy transfer between LHCII and PSII, possibly hardening the moss to subsequent stress by reducing the production of the reactive oxygen species near PSII. During desiccation, F ₀, F _m, F _v/F _m, PSII, and NPQ and F ₀ quenching declined in ABA-treated and nontreated mosses. However, during rehydration, F ₀, F _m, F _v/F _m, and PSII recovered faster in ABA-treated plants, suggesting that ABA improved the tolerance of photosystem II to desiccation. NPQ increased upon rehydration in mosses from both treatments, but much more rapidly in ABA-treated plants; during the first hour of rehydration, NPQ was two-fold greater in plants treated with ABA. F ₀quenching followed a similar pattern, indicating that ABA treatment stimulated zeaxanthin-based quenching. The implications of these results for the mechanisms of ABA-induced desiccation tolerance in A. undulatum are discussed.     

Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate

The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.