Ultraviolet Light-Induced Division Delay in Synchronized Chinese Hamster Cells

The age-dependent, ultraviolet light (UVL) (254 nm)-induced division delay of surviving and nonsurviving Chinese hamster cells was studied. The response was examined after UVL exposures adjusted to yield approximately the same survival levels at different stages of the cell cycle, 60% or 30% survival. Cells irradiated in the middle of S suffered the longest division delay, and cells exposed in mitosis or in G₁ had about the same smaller delay in division. Cells irradiated in G₂, however, were not delayed at either survival level. It was further established, after exposures that yielded about 30% survivors at various stages of the cycle, that surviving cells had shorter delays than nonsurvivors. This difference was not observed for cells in G₂ at the time of exposure; i.e., neither surviving nor nonsurviving G₂ cells were delayed in division. The examination of mitotic index vs. time revealed that most cells reach mitosis, but all of the increase in the number of cells in the population can be accounted for by the increase of the viable cell fraction. These observations suggest strongly that nonsurviving cells, although present during most of the experiment, are stopped at mitosis and do not divide. Cells in mitosis at the time of irradiation complete their division, and in the same length of time as unirradiated controls. Division and mitotic delays after UVL are relatively much larger than after X-ray doses that reduce survival to about the same level.     

Bracken-induced increase in soil P availability,along with its high P acquisition efficiency,enables it to invade P-deficient meadows

欧洲蕨入侵提高了土壤磷有效性和高磷获取效率 对于欧洲蕨(Pteridium aquilinum)入侵荒地后土壤化学的变化,已经有了相关的研究,但是对于欧洲蕨入侵草地的研究却比较缺乏。本研究探讨了欧洲蕨入侵缺磷草地是否会改变土壤养分资源库,以及与土壤过程和欧洲蕨营养相关的机制。此外,还研究了欧洲蕨入侵前后群落组成对土壤化学差异的反应。在蕨菜生物量高峰期间,我们进行了土壤和植物取样以及植被调查。数据分析包括方差分析(ANOVA)和典型对应分析(CCA)。研究结果表明,欧洲蕨入侵提高了土壤磷有效性、土壤有机碳浓度以及碳氮比、碳硫比和氮硫比,同时降低了铁和钴的浓度。欧洲蕨羽片富含磷,根茎富含钾,而羽片 和根茎的氮磷比很低。典型对应分析(CCA)显示了与磷和钾有效性相关的常见草地植物物种的不同丰度模式。在磷有效性极低的条件下,绒毛草(Holcus lanatus)表现出竞争优势。欧洲蕨通过促进铁和铝的浸出提高了磷有效性。从土壤资源生态位的角度来看,欧洲蕨通过提高自身生长所需的磷有效性并且增加对其他物种的氮限制,从而获得了竞争优势。欧洲蕨提高土壤磷有效性的能力,以及其高磷获取效率背后的生理机制,似乎将欧洲蕨与其他竞争生态策略的物种区分开来,因为其他物种的生长主要局限于营养丰富的环境,因此欧洲蕨更容易入侵缺磷的草地。     

Pediatric idiopathic intracranial hypertension: clinical and demographic features

Idiopathic intracranial hypertension (IIH) is a clinical condition characterized by elevated intracranial pressure and absence of clinical, laboratory or radiographic evidence of central nervous system infection, vascular malformation, intracranial space occupying lesion or hydrocephalus. In the last years the raising understanding of pediatric IIH, especially concerning its demographics and epidemiology, has brought up to a redefinition of diagnostic criteria and reevaluation of pathogenesis and treatment. The authors reviewed the records of nineteen consecutive children with newly diagnosed IIH in order to compare demographic characteristics, clinical pictures and ophthalmologic aspects as optic disc evaluation and visual field evaluation, as well as treatment modalities and follow up. Beside obesity and female gender, potential alternative risk factors remains to be investigated, which need a good collaboration between neuro-ophthalmologists and pediatric neurologists.     

Factors influencing the appearance of spider (Araneae) and beetle (Coleoptera) assemblages in nests of great reed warbler Acrocephalus arundinaceus

The appearance of spider (Araneae) and beetle (Coleoptera) assemblages found in nests of great reed warbler Acrocephalus arundinaceus was studied, firstly to investigate breeding success and the amount of precipitation as potential factors which might affect the abundance and species richness of both groups. In addition, we compared the diversity of spider and beetle assemblages between nests found in different reed habitats, and considered the position of nests (above water or dry ground). In this study we selected five different randomly chosen reed habitats: two mining ponds, two small canals and one large canal. Great Reed Warbler nests were collected either shortly after fledging, or after the clutch had failed. Altogether, 12 species of spider and 19 species of beetle were collected. In both groups there was no significant difference in abundance between successful, lost and cuckoo-parasitized nests; however, there was a significant difference in species richness between the three nest categories in spider assemblages, which was not the case in beetle assemblages. The amount of precipitation did not affect beetle or spider abundance; only the species richness of spiders showed significant growth. Furthermore, we found no significant relationship between vegetation cover and the species richness and abundance of spiders and beetles. The diversity of both groups differed significantly according to reed habitat: beetle assemblages were most diverse by the large canal and spiders at the mining ponds.     

Taxon specific response of carabids (Coleoptera,Carabidae) and other soil invertebrate taxa on invasive plant Amorpha fruticosa in wetlands

False indigo (Amorpha fruticosa L.) is an invasive exotic plant introduced to Europe in the early eighteenth century. Its spread has been rapid, particularly in disturbed wetland habitats, where it forms dense impermeable monospecific stands and modifies habitat conditions. The impact of A. fruticosa on native plant communities has been well analyzed, however knowledge concerning the possible effects on soil invertebrates and particularly carabid beetles is completely lacking. This study analyzed the impact of an A. fruticosa invasion on carabid beetles and other soil invertebrates. Soil fauna was sampled by pitfall traps at natural habitats, initially colonized by A. fruticosa, and habitats largely invaded by A. fruticosa. In total 2,613 carabid beetles belonging to 50 species and 72,166 soil invertebrates were collected. The invasion of A. fruticosa strongly affected the carabid beetle species composition, which clearly differed between all studied sites. Widespread euritopic carabid beetle species showed positive responses to A. fruticosa invasion, while the activity density of open habitat species strongly declined. Mean individual biomass was significantly higher at invaded sites due to increased incidence of large carabids (genus Carabus Linné, 1758). Carabid beetle activity density and abundance of soil invertebrates were considerably higher at invaded sites than in natural sites. Conversely, the impact of A. fruticosa on carabid beetle species richness and diversity was less pronounced, most likely due to immigration from adjacent habitats. Changes in carabid beetle species composition and abundance of soil invertebrates were most likely due to changes in vegetation structure and microclimate. The results suggest that A. fruticosa invasion considerably affected carabid beetles, an insect group that is only indirectly related to plant composition. Therefore, severe future changes can be expected in invertebrate groups that are closely related to plant composition, since A. fruticosa cannot be completely removed from the habitat and covers relatively large areas.     

Metabolic evaluation of urolithiasis patients from eastern Croatia

Metabolic parameters were determined in fasting blood serum, fasting first morning urine, and 24-hour urine of male patients with recurrent calcium oxalate stones (N = 26, age 39.1 +/- 6.2 years) as well as in male healthy controls (N = 18, age 35.0 +/- 7.1 years), recruited from the eastern part of Croatia. The 24-hour urinary calcium excretion was significantly higher (p < 0.01) for patients (5.6 +/- 2.5 mmol) than for controls (3.7 +/- 1.9 mmol), but potassium excretion was higher (p < 0.01) for controls (74.5 +/- 33.8 mmol) than for patients (49.2 +/- 15.7 mmol). The mean ionic activity product of calcium and oxalate ions, IAP(CaOx), calculated from the fasting first morning urine parameters, was 25% higher for patients than for controls, but the difference was not statistically significant (p > 0.05). Very strong correlation (r = 0.97) was obtained between IAP(CaOx) values and calculated Ogawa indices that were recommended for estimating the potential risk for calcium oxalate stone formation.     

Sensitivity of Synchronized Chinese Hamster Cells to Ultraviolet Light

The age response for lethality of Chinese hamster cells to ultraviolet light shows that they are resistant in G(1), sensitive as they move into and through the S phase and resistant again in G(2) and mitosis. Survival curves determined at different times in the cycle reveal that mitotic cells are the most resistant fraction, much more resistant than S cells, and more resistant than either G(1) or G(2) cells. The extent to which the age response is ilfluenced by nucleic acid and protein synthesis was investigated by using inhibitors of these processes. In the presence of inhibitors of DNA or protein synthesis added to G(1) cells before exposure, cell survival neither declines to the minimum survival of S cells nor rises subsequently to the resistance of G(2) cells. If, before exposure, DNA synthesis is arrested in the middle of S, when survival is at a minimum, the subsequent rise in survival during G(2) is not prevented. However when cycloheximide is added before exposure, during the middle of S, this rise is prevented. When actinomycin D, an inhibitor of RNA synthesis is added prior to exposure the age response is affected only slightly. Postirradiation treatment of G(1) and mid-S cells with inhibitors of DNA or protein synthesis maintains survival at a level characteristic of the age of the cells.     

An automated, polymer-assisted strategy for the preparation of urea and thiourea derivatives of 15-membered azalides as potential antimalarial chemotherapeutics

A series of 15-membered azalide urea and thiourea derivatives has been synthesized and evaluated for their in vitro antimalarial activity against chloroquine-sensitive (D6), chloroquine/pyremethamine resistant (W2) and multidrug resistant (TM91C235) strains of Plasmodium falciparum. We have developed an effective automated synthetic strategy for the rapid synthesis of urea/thiourea libraries of a macrolide scaffold. Compounds have been synthesized using a solution phase strategy with overall yields of 50-80%. Most of the synthesized compounds had inhibitory effects. The top 10 compounds were 30-65 times more potent than azithromycin, an azalide with antimalarial activity, against all three strains.     

Complications after hip rearthroplastics with revision endoprosthesis

The stability of the revision endoprosthesis components is more difficult to achieve than in primary endoprosthesis due to large bone defects and/or decreased bone mass quality. That is the reason for more frequent complications for revision than in primary arthroplasty. The aim of this study was to investigate the frequency of complications in 122 patients who were operated with the revision endoprosthesis in the Department of Orthopedics in University Hospital Split in the period of 1998 to 2007 and accepted to participate in this study. There were 3 patients treated on bought hips. The average follow up time was four years (0.6-10.6). There were 32 (26.2%) males and 90 (73.8%) females. The average age was 70.66 +/- 7.63 years. The average time from operation to physical therapy was 3.53 +/- 2.56 days. There were 27 (21.6%) complications. The most common complication was infection in 9 (7.2%) cases. From those cases, 4 (3.2%) had superficial, and 5 (4%) had deep infection. From other complications, there were 5 (4%) endoprosthesis reluxations, 2 (1.6%) periprosthetic femur fractures, 5 (4%) urinary infections, and 6 (4.8%) other complications (lung mycroembolia, heart infarction, lumbal plexus lesion from L2, spinal cord infarction with paraplegia, pneumonia and severe sacral bed-sore). There were 10 (8%) re-interventions following the revision arthroplasty. The result was good or excellent in 80% of operated patients, satisfied in 17%, and bad in 3%. The revision hip procedures are characterized with a high complications incidence rate. Our results are comparable with the results from literature.     

Plants and geographical names in Croatia

The main purpose of this paper is to present some general observations, regularities and insights into a complex relationship between plants and people through symbolic systems like geographical names on the territory of Croatia. The basic sources of data for this research were maps from atlas of Croatia of the scale 1:100000. Five groups of maps or areas were selected in order to represent main Croatian phytogeographic regions. A selection of toponyms from each of the map was made in which the name for a plant in Croatian language was recognized (phytotoponyms). Results showed that of all plant names recognized in geographical names the most represented are trees, and among them birch and oak the most. Furthermore, an attempt was made to explain the presence of the most represented plant species in the phytotoponyms in the light of general phytogeographical and sociocultural differences and similarities of comparing areas. The findings confirm an expectation that the genera of climazonal vegetation of particular area are the most represented among the phytotoponyms. Nevertheless, there are ample examples where representation of a plant name in the names of human environment can only be ascribed to ethno-linguistic and socio-cultural motives. Despite the reductionist character of applied methodology, this research also points out some advantages of this approach for ethnobotanic and ethnolinguistic studies of greater areas of human environment.