Neocarzinostatin: an antitumor protein a preliminary x-ray diffraction study.

The antitumor protein, neocarzinostatin, has been crystallized and examined by X-ray diffraction. Crystals of this globular protein are of space group P2₁2₁2₁ with cell parameters a = 27.4Å, b = 33.9Åand c = 102.0Å. There is one molecule of approximately 27Ådiameter per asymmetric unit. Crystals soaked in a K₂HgI₄ solution give diffraction patterns significantly different from native crystal diffraction patterns.     

Detection of mutagens in water-distribution systems after disinfection

This research examined the quality of water-before and after distribution-of four drinking-water production plants located in Northern Italy, two of which collected water from local aquifers and two from the River Po. A battery of genotoxicity assays for monitoring drinking-water was performed to assess the quality of the water produced by the treatment plants under study. Three different sampling stations were selected at each plant, one right at the outlet of the treatment plant and two along with the distribution pipelines. Raw river water was also sampled and analysed as a control. The water samples (500 l) were concentrated on silica C18 cartridges and the extracts were tested in in vitro mutagenicity assays (Salmonella/microsome assay with strains TA 98 and TA 100; SOS Chromotest with Escherichia coli strain PQ37); gene conversion, point mutation and mitochondrial DNA mutability assays with the diploid Saccharomyces cerevisiae strain D7 and a toxicity test using the bioluminescent bacterium Vibrio fischeri (Microtox). The Microtox test and the mitochondrial DNA mutability assay showed the greatest sensitivity towards toxic or mutagenic substances in the water extracts considered. The results show that this battery of short-term tests is applicable in the routine monitoring of drinking-water quality before and after distribution.     

Wound healing potential of ethanolic extract of Kalanchoe pinnata Lam. leaf--a preliminary study

The extract of K. pinnata was evaluated for its wound healing activity by using excision wound model in rats. On day 11, animals treated with the ethanolic leaf extract exhibited 86.33% reduction in the wound area, compared to petroleum jelly treated control (69.36%) and the mupirocin treated standard (85.49%). The hydroxyproline content of extract treated animals was higher, as compared to control and the standard groups. Histological analysis was also consistent with the proposal that K. pinnata leaf extract exhibits significant wound healing potential. The increased rate of wound contraction and hydroxyproline content in the extract treated animals supports the claims made by traditional healers of the benefits obtained from the medicinal use of K. pinnata.     

Detection of cytokinins in a seaweed extract

trans-Zeatin, trans-zeatin riboside, their dihydro derivatives, isopentenyladenine and isopentenyladenosine have been identified and quantified in Seasol, a commercial extract of Tasmanian Giant Bull kelp, Durvillea potatorum.     

Use of a copper-phthalocyanine membrane electrode for rapid preliminary detection of polycyclic mutagens

Preliminary screening of polycyclic mutagens is achieved within 20 min by using a biomimetic electrode composed of an oxygen electrode and a copper-phthalocyanine membrane. When benzo[alpha]pyrene (0.05 mM) was added to the buffer solution in the presence of 0.98 M hydrogen peroxide, the current of the phthalocyanine electrode decreased. A linear relationship was obtained between the current decrease and the benzo[alpha]pyrene concentration over the range 0.19-0.60 mM. The minimum measurable concentration for benzo[alpha]pyrene was 0.01 mM. Such responses were not obtained for other organic compounds such as alcohol, ether, n-hexane and cyclohexane. The copper-phthalocyanine membrane electrode has selectively detected polycyclic mutagens such as amino acid pyrolysis products. The current decrease was 1.18-1.46 microA when 0.05 mM amino acid pyrolysis products were employed.     

南极地衣提取物抗氧化能力的初步研究

本文讨论4种南极地衣簇花石萝Usnea aurantiacoatra,南极石萝Usnea antarctica,粉球衣Sphaerophorus globosus及一种石蕊Cladonia sp.甲醇提取物的体外抗氧化能力;采用亚油酸氧化体系、二苯代苦味酰自由基体系、还原力实验对其抗氧化活性进行测定,并同维生素C、丁基甲氧基苯酚进行比较。结果显示供试南极地衣均具有较高的抗氧化活性,且呈剂量依赖关系;其中,簇花石萝的脂质过氧化抑制率最高,还原力最大;石蕊的二苯代苦味酰自由基清除能力最大。此外,从簇花石萝中提取的松萝酸具有一定的抗氧化活性,但明显低于簇花石萝粗提物。     

Detection of volatile mutagens in creosote and coal tar

Creosote and coal tar were examined for the presence of volatile mutagens by use of the so-called "taped plate assay". Application of this method, recently published by Distlerath et al., reveals that vapour escaping from creosote and coal tar at 37 degrees C was able to revert the Salmonella typhimurium strains TA98 and TA100 in the presence of S9 mix. The simplicity of this method makes it useful for routine screening of industrial fluids or solid products for the presence of volatile mutagens.     

Aged garlic extract attenuates intracellular oxidative stress.

Oxidation of low density lipoprotein (LDL) has been recognized as playing an important role in the initiation and progression of atherosclerosis. We recently reported that aged garlic extract (AGE) inhibited LDL oxidation and minimized oxidized LDL-induced cell injury. In this study, the antioxidant effects of AGE were further examined using bovine pulmonary artery endothelial cells (PAEC) and murine macrophages. Lactate dehydrogenase (LDH) release, as an index of membrane injury, and intracellular glutathione (GSH) levels were determined. Oxidized LDL (Ox-LDL) caused an increase of LDH release and depletion of GSH. Pretreatment with AGE prevented these changes. AGE exhibited an inhibition of Ox-LDL-induced peroxides in PAEC. AGE suppressed peroxides in murine Macrophage (J774 cells) dose-dependently. The J774 cells were also incubated with AGE, interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) and nitric oxide (NO) production was measured. AGE inhibited NO production in J774 cells. In a cell free system, AGE was shown to scavenge H2O2 dose-dependently. Our data demonstrate that AGE can protect the endothelial cells from oxidized LDL-induced injury by preventing depletion of intracellular GSH and by removing peroxides. AGE also reduces levels of NO and peroxides in macrophages. These data suggest that AGE is a useful protective agent against cytotoxicity associated with Ox-LDL and NO, and it may thus be useful for the prevention of atherosclerosis and cardiovascular diseases.     

Detection of a cell-cycle inhibitor of Petunia hybrida protoplasts in an Arthrospira platensis extract

A chloroform crude extract of whole Arthrospira platensis cells, provisionally named A. platensis auto-inhibitor (APAI), was inhibitory to growth of human prostatic cells and was toxic to them at less than 25 g/ml. With cultured protoplasts of Petunia hybrida, APAI was growth inhibitory, without cytotoxicity, at 500 g/ml. Using flow cytometry, it was seen that APAI induced arrest of the plant cell division cycle at the G1 phase. © Rapid Science Ltd. 1998     

Detection of mutagens produced by fungi with the Salmonella typhimurium assay.

Forty-one fungal isolates (one isolate per species) representing common plant pathogens and food crop contaminants were grown on sterile, polished rice and assayed for mutagenic activity in the Salmonella typhimurium-microsome system. Initially, single doses of aqueous and chloroform extracts of the moldy rice were assayed against the TA100 tester strain by incorporating extracts into the growth medium and by applying small quantities on disks placed on the agar surface. Suspected activity was examined further by analysis of several doses in the plate incorporation assay. Extracts of two aflatoxin-producing isolates (Aspergillus flavus and A. parasiticus) showed pronounced mutagenic activity, as did extracts of five other isolates (A. heterothallicus, A. nidulans, A. terricola, Alternaria tenuis, and Fusarium moniliforme) which did not contain detectable aflatoxins. Seven additional isolates (Botrytis cineria, Ceratocystis fimbriata, Cladosporium herbarum, Fusarium solani f. sp. pisi, Penicillium oxalicum, Thermomyces lanuginosus, and Verticilium albo-atrum) revealed activity which was possibly mutagenic; i.e., mutagenic responses were not observed in both the disk and incorporation assays, and clear dose-related activity was not observed in the incorporation assay. Extracts of the remaining fungi were not mutagenic in the bacterial assay.     

Detection of mutagens produced by fungi with the Salmonella typhimurium assay.

Forty-one fungal isolates (one isolate per species) representing common plant pathogens and food crop contaminants were grown on sterile, polished rice and assayed for mutagenic activity in the Salmonella typhimurium-microsome system. Initially, single doses of aqueous and chloroform extracts of the moldy rice were assayed against the TA100 tester strain by incorporating extracts into the growth medium and by applying small quantities on disks placed on the agar surface. Suspected activity was examined further by analysis of several doses in the plate incorporation assay. Extracts of two aflatoxin-producing isolates (Aspergillus flavus and A. parasiticus) showed pronounced mutagenic activity, as did extracts of five other isolates (A. heterothallicus, A. nidulans, A. terricola, Alternaria tenuis, and Fusarium moniliforme) which did not contain detectable aflatoxins. Seven additional isolates (Botrytis cineria, Ceratocystis fimbriata, Cladosporium herbarum, Fusarium solani f. sp. pisi, Penicillium oxalicum, Thermomyces lanuginosus, and Verticilium albo-atrum) revealed activity which was possibly mutagenic; i.e., mutagenic responses were not observed in both the disk and incorporation assays, and clear dose-related activity was not observed in the incorporation assay. Extracts of the remaining fungi were not mutagenic in the bacterial assay.     

Cultivable microscopic fungi from an underground chemosynthesis-based ecosystem: a preliminary study

Movile Cave, a unique groundwater ecosystem in southern Romania, was discovered in 1986. This chemoautotrophic cave contains an abundant and diverse fauna with terrestrial and aquatic invertebrate communities, including 33 endemic species. Since its discovery, studies have focused mainly on cave chemoautotrophic bacteria, while the microfungal community has been largely neglected. In this study, we determined the microfungal species living on various substrates in Movile Cave and compared this spectrum with the mycobiota detected outside the cave (outside air-borne and soil-borne microfungi). To investigate all of the niches, we collected samples for two consecutive years from the dry part of the cave (cave air and sediment, corroded limestone walls, isopod feces, and isopod and spider cadavers) and from the post-siphon part of the cave, i.e., Airbell II (sediment and floating microbial mat). A total of 123 microfungal species were identified from among several hundred isolates. Of these, 96 species were only detected in the cave environment and not outside of the cave, while 90 species were from the dry part of the cave and 28 were from Airbell II. The most diverse genera were Penicillium (at least 18 species) and Aspergillus (14 species), followed by Cladosporium (9 species). Surprisingly, high CFU counts of air-borne microfungi were found inside the cave; they were even higher than outside the cave during the first year of investigation.     

Breast compression: a preliminary study

X-Ray mammography is the technique employed to image breast tumours; it is the gold standard for both diagnosis and screening¹. To increase the sensitivity of the test and to reduce the dose of X-radiation, breast compression is used. The effect of squeezing a simple model of a breast in which there is an idealized spherical tumour volume is investigated; the cases where the lesion has both a smaller, and a larger compressibility than the surrounding tissues are considered. Surface strain is computed as a function of the deformation of the lesion from its spherical shape. Evidence from earlier studies is adduced to show that when the lesion is malignant care should be exercised to avoid the possibility of disseminating cancer cells by the application of compressive forces.     

Heavy metal pollution in surface water and sediment: A preliminary assessment of an urban river in a developing country

The concentration and chemical fractionation of globally alarming six heavy metals (Cr, Ni, Cu, As, Cd and Pb) were measured in surface water and sediment of an urban river in Bangladesh. The decreasing trend of metals were observed in water as Cr > Cu > As > Ni > Pb > Cd and in sediment as Cr > Ni > Cu > Pb > As > Cd. The level of studied metals exceeded the safe limits of drinking water, indicated that water from this river is not safe for drinking and/or cooking purposes. However, the investigated metals showed low mobility except for Cd and Pb which could pose a severe threat to the aquatic environment. Contamination factor (CF) and geoaccumulation index (I_geo) demonstrated that most of the sediment samples were moderately to heavily contaminated by Cr, As, Cd and Pb. The pollution load index (PLI) values were above one (>1) indicates progressive deterioration of the sediment quality. The extent of pollution by heavy metals in the river Korotoa implies that the condition is much frightening to the biota and inhabitants in the vicinity of the river as well.