bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterning High Explosives at the Nanoscale
Authors: Nafday Omkar A. , Pitchimani Rajasekar , Weeks Brandon L. , Haaheim Jason
Published: October 2006

For the first time, we have shown that spin coating and Dip pen nanolithography (DPNTM) are simple methods of preparing energetic materials such as PETN and HMX on the nanoscale, requiring no heating of the energetic material. Nanoscale patterning has been demonstrated by the DPN method while continuous thin films were produced using the spin coating method. Results are presented for preparing continuous PETN thin films of nanometer thickness by the spin coating method and for controlling the architecture of arbitrary nanoscale patterns of PETN and HMX by the DPN method. These methods are simple for patterning energetic materials and can be extended beyond PETN and HMX, opening the door for fundamental studies at the nanoscale.
Preparation and Characterization of Nano‐TATB Explosive
Authors: Yang Guangcheng , Nie Fude , Huang Hui , Zhao Lin , Pang Wanting
Published: October 2006

Nano‐TATB was prepared by solvent/nonsolvent recrystallization with concentrated sulfuric acid as solvent and water as nonsolvent. Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) were used to characterize the appearance and the size of the particles. The results revealed that nano‐TATB particles have the shape of spheres or ellipsoids with a size of about 60 nm. Due to their small diameter and high surface energy, the particles tended to agglomerate. By using X‐ray powder diffraction (XRD), broadening of diffraction peaks and decreasing intensity were observed, when the particle sizes decreases to the nanometer size range. The corrected average particle size of nano‐TATB was estimated using the Scherrer equation and the size ranged from 27 nm to 41 nm. Furthermore, the specific surface area and pore diameter of nano‐TATB were determined by BET method. The values were 22 m2/g and 1.7 nm respectively. Thermogravimetric (TG) and Differential Scanning Calorimetric (DSC) curves revealed that thermal decomposition of nano‐TATB occurs in the range of 356.5 °C–376.5 °C and its weight loss takes place at about 230 °C. Furthermore, a slight increase in the weight loss was observed for nano‐TATB in comparison with micro‐TATB.
MIR/NIR/FIR Characterization of Poly‐AMMO and Poly‐BAMO and their Precursors as Energetic Binders to be Used in Solid Propellants
Authors: de Oliveira José Irineu S. , Diniz Milton F. , Kawamoto Aparecida M. , Dutra Rita C. L. , Keicher Thomas
Published: October 2006

To establish the relation between structure and properties of composite solid propellants it is important to know the structure of the elastomeric binder that has been used in the system. Therefore this study is focused on the characterization of polymers containing energetic groups that has been synthesized at ICT. The characterization uses the wide spectral band of infrared, NIR/MIR/FIR. This gives an identification of the analytical bands and allows quantitative and kinetic studies of these compounds.
Characterization and safe handling of reactive initiator solutions
Authors: Klein James A. , Mros Gordon R.
Published: October 2006

The thermal stability of initiators used in free radical polymerizations has been well documented. Initiators are often used in solutions, with relatively long feed periods to help control the heat of polymerization. In some cases, the stability of the initiator solutions is limited, especially at higher concentrations, and runaway reactions can potentially be severe. This article reviews the chemical reactivity of concentrated initiator solutions and considers PHA studies and feed tank design to help ensure safe handling and manufacture. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006
Evaluation of khat (Catha edulis Forssk) for antifertility activity in rats
Authors: Tariq M. , Parmar N. S. , Islamr M. W. , Ai‐Meshal I. A.
Published: October 2006

The effect of the methanolic extract of khat (Catha edulis Forssk) was studied on female fertility in rats. The parameters included the effect on oestrus cycle, implantation, foetal loss, abortion, inhibition of uterotrophic activity and teratogenicity. The extract, in the doses of 250 and 500 mg/kg, produced dose dependent and significant anti‐implantation activity. However, it failed to produce complete infertility in this dose range. Treatment of animals during day 8 to day 12 of pregnancy produced significant abortifacient activity. There was significant decrease in the weight and length of foetuses delivered by rats treated with the extract but there were no gross abnormalities in the organs of the offsprings. It also produced significant anti‐oestrogenic activity as assessed by the mean weight of the uteri of rats treated with oestradiol and its combination with the khat extract.
Bioactive furanocoumarins from the berries of Zanthoxylum americanum
Authors: Saqib Q. N. , Hui Y.‐H. , Anderson J. E. , McLaughlin J. L.
Published: October 2006

Crude extracts of the berries of Zanthoxylum americanum showed significant lethality to brine shrimp larvae and exhibited cytotoxicity to human tumor cells. Activity‐directed fractionation led to 5 furanocoumarins (cnidilin, imperatorin, isoimperatorin, psoralen, and xanthotoxin), the last three of which are bioactive in these bioassays. All were previously known as natural compounds but are new to this plant species.
Inhibition of clastogenic effects of nicotine by chlorophyllin in mice bone marrow cells in vivo
Authors: Sen Soumitra , Sharma Archana , Talukder Geeta
Published: October 2006

The effect of chlorophyllin in modifying the clastogenic action of nicotine was tested in vivo on mice bone marrow cells. Nicotine, when administered by gavage, induced chromosomal aberrations in frequencies directly proportional to the dose. Maximum effects were recorded at 6 h after exposure. Chlorophyllin, when given alone, was not clastogenic even at the highest concentration (1.50 mg/kg body wt). Simultaneous administration of nicotine and chlorophyllin with even lower doses (1.25 and 0.77 mg/kg body wt) reduced the frequency of chromosomal aberrations to the normal level. Chlorophyllin alone, given 2 h before nicotine, however, did not counteract the effects of nicotine. The use of green plant parts in modifying the genotoxicity of different agents may be related to the protective action of chlorophyllin.
Studies on plant resources, pharmacology and clinical treatment with berbamine
Authors: Liu Chang‐Xiao , Xiao Pei‐Gen , Liu Guo‐Sheng
Published: October 2006

In the present paper, the plant resources, chemistry, pharmacology and clinical therapy of berbamine are reported. From a botanical survey it was found that there are 32 species of Berberis plants containing berbamine utilized in China. Pharmacological studies demonstrated that berbamine possesses significant leukogenic effects in rats and dogs injured by an anticancer agent, and clinical observations demonstrated a therapeutic effect in 405 patients with leukopenia. It is suggested that berbamine may not only be useful as a leukogenic drug but is also useful as an adjuvant in cancer chemotherapy and radiotherapy.
Antiinflammatory, antitumour and antifertility effects in rodents of two nor‐cucurbitacin glucosides from Wilbrandia species
Authors: Almeida F. R. C. , Rao V. S. N. , Matos M. E. O.
Published: October 2006

The purified fraction (PF) of the rhizome of Wilbrandia sp. (Cucurbitaceae) that contained two nor‐cucurbitacin glucosides (WG1 and WG2) demonstrated potent antiinflammatory, antitumour and antifertility effects in rats and mice at oral doses ranging from 50 to 200 mg/kg. In rat, it significantly inhibited carrageenan‐induced hind paw oedema and granulomatous lesion, while in mice the increased vascular permeability induced by acetic acid was markedly reduced. The PF exhibited an antitumour effect in rats bearing Walker 256 carcinosarcoma and also demonstrated cytotoxic action against KB cells in vitro. In regularly cycling mice, PF treatment suppressed the incidence of the oestrus phase of the reproductive cycle suggesting a possible antiovulatory effect. The rats that received PF from days 1 to 7 of pregnancy showed either a total absence or a reduced number of implantations in utero. The PF failed to exhibit abortifacient, oestrogenic or antioestrogenic actions. The results indicate that the nor‐cucurbitacin glucosides of Wilbrandia sp. possess a novel spectrum of pharmacological activity different from that of cucurbitacins described earlier from other plants of this family.
Oligo‐ and macrocyclic diterpenes in thymelaeaceae and euphorbiaceae occurring and utilized in Yunnan (Southwest China). 2. Ingenane type diterpene esters from Euphorbia nematocypha Hand.‐Mazz
Authors: Dagang Wu , Sorg B. , Adolf W. , Seip E. H. , Hecker E.
Published: October 2006

The highly irritant new Euphorbia factors N1 and N2 were isolated as a mixture from latex of E. nematocypha Hand.‐Mazz., by a combination of counter current distribution and chromatographic methods. Spectroscopic and chemical analyses revealed their structures to be 3‐0‐(2,4,6,8‐tetradecatetraenoyl)ingenol (1) and 3‐0‐(2,4,6,8‐pentadecatetraenoyl)ingenol (2), respectively.
Biota (Po‐Tzu‐Jen), a traditional Chinese medicine, ameliorates the memory acquisition disorder induced by amygdala lesion in mice
Authors: Nishiyama Nobuyoshi , Yuan‐Liang Wang , Kaimori Jun'Ya , Ishihara Akane , Saito Hiroshi
Published: October 2006

The effects of Biota orientalis (L.) Endl. (biota), a traditional Chinese medicine on learning performances were investigated. Nine weeks old male ddY mice recieved bilaterial amygdala lesions by delivery of a radiofrequency current. Biota (250 and 500 mg/kg/day) was administered orally from the day of the lesion until the end of the experiment. From 15 days after surgery, a step‐down type passive avoidance test was performed daily for 12 days. Lesioned animals showed severe impairment in the acquisition and retention processes. Biota ameliorated the memory acquisition deficit. The number of step‐down events in the acquisition and in the first testing trial was significantly decreased. Moreover, the mean number of days required to reach the memory acquisition criterion was markedly earlier in biota treated groups than in the lesioned control and almost similar to that in the naive control. Biota did not, however, alter the memory retention, choline acetyltransferase activity in the cortex, hippocampus and hypothalamus, and microscopic pathological changes induced by amygdala lesion. These results indicate that the memory acquisition enhancing effect of biota may not be due to a direct activation of cholinergic transmission in those areas nor to a mitigation of the pathological damage of the lesioned site but due to other unknown mechanisms.
Antifertility activity of the floral buds of Jasminum officinale var. grandiflorum in rats
Authors: Iqbal M. , Ghosh A. K. M. , Saluja A. K.
Published: October 2006

The effect of an aqueous extract of fresh floral buds of Jasminum officinale var. grandiflorum Linn. has been studied on female fertility in rats. Parameters included effects on the oestrus cycle, implantation, fetal loss, abortion, teratogenicity and serum progesterone levels on days 5, 12 and 20 of pregnancy. The extract at oral doses of 250 and 500 mg/kg produced a dose dependent significant antiimplantation effect, but failed to produce complete infertility. Treatment of animals during day 8 to day 12 to day 20 of pregnancy did not produce any significant abortifacient activity. There was no significant change in the weight and length of the fetuses delivered by rats treated with extract and no abnormalities were seen in the organs of the offspring. The extract produced a significant decrease in serum progesterone levels on day 5 of pregnancy which may be responsible for the antiimplantation effect observed in this study.
Ultraviolet radiation‐induced lipid peroxidation in liposomal membrane: Modification by capsaicin
Authors: De A. K. , Ghosh J. J. , Mandal T. K.
Published: October 2006

Ultraviolet‐radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8‐methyl‐n‐vanillyl‐6‐nonenamide), the pungent principle of red hot pepper, was shown to modify UV‐induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV‐induced lipid peroxidation, while high doses (0.1–0.5 μg/mL of PC liposome) caused a significant decrease of UV‐induced peroxidation. These pro‐oxidant and antioxidant activities of capsaicin over UV‐induced liposomal lipid peroxidation were also comparable to experiments modulated with standard pro‐oxidant ferrous sulphate and antioxidant sodium azide. The observed dual nature of capsaisin's action on the UV‐induced lipid peroxidation of the liposomal membrane may be attributed to the previously reported “activation” followed by “desensitization” action of capsaicin on other membrane lipid systems.
Antiprotozoal activity of dehydrozaluzanin C, a sesquiterpene lactone isolated from Munnozia maronii (asteraceae)
Authors: Fournet Alain , Muñoz Victoria , Roblot François , Hocquemiller Reynald , Cavé André , Gantier Jean‐Charles
Published: October 2006

The petroleum ether extract of the leaves of Munnozia maronii was found to inhibit in vitro the growth of promastigote forms of Leishmania and epimastigote forms of Trypanosoma cruzi with an IC90 of 25 μg/mL. Activity‐guided fractionation of the extract by chromatography identified the sesquiterpene lactone 1 of the guaiane series. The complete structure of 1 was elucidated using 1H and 13C NMR experiments at high field. The isolated compound was shown to be a new natural guaianolid, dehydrozaluzanin C, previously known as synthetic oxidative derivative of zaluzanin C (Romo de Vivar et al., 1967). This compound inhibited, in vitro, the growth of 12 strains of Leishmania and 15 strains of T. cruzi at concentrations between 50 and 2.5 μg/mL. The leishmanicidal activity of dehydrozaluzanin C was tested on BALB/c mice infected with amastigote forms of Leishmania amazonensis. Dehydrozaluzanin C reduced the severity of L. amazonesis lesions in BALB/c mice but was less active than the reference compound Glucantime.
Effects of standardized extracts GK501, from Ginkgo biloba L., G115 from Panax ginseng C. A. Meyer, and their combination, gincosan® (PHL‐00701), on the brain levels of biogenic monoamines and on the serum content of prolactin, growth hormone and ACTH
Authors: Petkov V. D. , Hadjiivanova C. , Petkov V. V. , Milanov S. , Visheva N. , Boyadjieva N.
Published: October 2006

In experiments on old (26 months old) rats, we found that the extracts of Panax ginseng (G115), Ginkgo biloba (GK501) and their combination Gincosan® (PHL‐00701) administered orally at two doses for 7 days induced changes in the levels of biogenic monoamines in some brain regions (frontal cerebral cortex, hippocampus, striatum, hypothalamus and pons). The most characteristic change was the increase produced by the two extracts and their combination in the serotonin level in all brain structures except for pons compared with controls. In the hippocampus G115, GK501 and their combination decreased the noradrenaline level. The same doses of G115, GK501 and their combination applied for 7 days to young (3 months old) and old (26 months old) rats caused significant changes in the blood level of prolactin (PRL), growth hormone (GH) and ACTH compared with age‐matched controls: both G115 and GK501 decreased the serum level of PRL compared with age‐matched controls; the hormone level being high in old controls, in extract‐treated rats it became equal to that in young controls; G115 and PHL‐00701 greatly increased the serum level of ACTH in both age groups compared with age‐matched controls. Under conditions of induced immobilization and cold stress in young rats, the 7‐day pretreatment with G115, GK501 and their combination led to significant changes in the blood levels of PRL, GH and ACTH compared with control untreated stressed and unstressed rats.
Hepatoprotective effects of Pluchea indica (less) extract in experimental acute liver damage in rodents
Authors: Sen T. , Basu A. , Ray R. N. , Nag Chaudhuri A. K.
Published: October 2006

The methanol fraction of the extract of Pluchea indica roots exhibited significant hepatoprotective activity against experimentally induced hepatotoxicity by carbon tetrachloride in rats and mice. The extract caused significant reduction of the elevated serum enzyme levels (AST, ALT, LDH and serum alkaline phosphatase) and serum bilirubin content in acute liver injury. A significant increase of reduced serum total protein, albumin and albumin/globulin ratio was also observed on extract treatment. The extract significantly reduced the prolonged pentobarbitone‐induced sleeping time and also caused a significant reduction of plasma prothrombin time in comparison with CCl4‐treated animals. The extract caused significant reduction of the increased bromosulphalein retention by CCl4‐treatment. These findings are suggestive of a potent hepatoprotective effect of the extract under investigation.
In vitro inhibition of mycobacteria by Rwandese medicinal plants
Authors: van Puyvelde L. , Ntawukiliyayo J. D. , Portaels F. , Hakizamungu E.
Published: October 2006

A series of 15 Rwandese medicinal plants used by traditional healers to treat pulmonary diseases were screened for anti‐Mycobacterium tuberculosis activity. Three plant extracts showed activity at 1000 μg/mL: Bidens pilosa (leaves), Pentas longiflora (roots) and Tetradenia riparia (leaves). These plant extracts were studied further against several mycobacterial species: M. tuberculosis, M. avium complex, M. simiae and a new simiae like Mycobacterium species (SLM). None of the plant extracts showed activity against M. avium and SLM at 1000 μg/mL. M. simiae was sensitive to T. riparia and P. longiflora extracts (1000 μg/mL) and M. tuberculosis towards T. riparia (500 μg/mL) and B. pilosa (100 μg/mL). The active principle of T. riparia, 8(14), 15‐sandaracopimaradiene‐7α, 18‐diol, was also evaluated for its antimycobacterial activity and the concentration required for inhibiting M. tuberculosis ranged from 25 μg/mL to 100 μg/mL. The extract of the leaves of T. riparia can be used as a differentiation test (at 1000 μg/mL in the medium) for M. simiae and SLM.
Hypotensive and diuretic effect of Equisetum bogotense and Fuchsia magellanica and micropropagation of E. bogotense
Authors: Rodriguez J. , Pacheco P. , Razmilic I. , Loyola J. I. , Schmeda‐Hirschmann G. , Theoduloz C.
Published: October 2006

Equisetum bogotense (Equisetaceae) and Fuchsia magellanica (Onagraceae) were used by the Mapuche Amerindians as diuretics. Intravenous administration of hydroalcoholic extracts to rats elicited a hypotensive response of −29.0% ±4.5% and −24.2% ±0.5% respectively in the mean blood pressure of normotensive animals at a dose of 5 mg crude extract/kg body weight. The activity was found to be related with polar compounds. For Fuchsia, the active principles are related to tannins. A single oral dose of 500 mg/kg body weight Equisetum extract produced a significant increase (p < 0.05) in the urine output in rats, while in Fuchsia a reduction in diuresis was observed. The diuretic effect of the Equisetum extract was weak compared with hydrochlorothiazide at 25 mg/kg body weight. The data presented support the use of E. bogotense in Chilean traditional medicine. A micropropagation method for E. bogotense was established by culturing shoot tips in Murashige‐Skoog medium with macro and micronutrients diluted 4‐fold and containing 0.1 mg/L thiamine, 100 mg/L myoinositol, 1.0 mg/L NAA and 0.1 mg/L BAP.
Hepatoprotective effects of Taiwan folk medicine: Alternanthera sessilis on liver damage induced by various hepatotoxins
Authors: Lin Song‐Chow , Lin Yun‐Ho , Shyuu Shyh‐Jong , Lin Chung‐Ching
Published: October 2006

The hepatoprotective effects of the Taiwanese herb ‘Horngtyan‐wu’ (Alternanthera sessilis (L.) DC.) were investigated in three kinds of experimental animal model. Acute hepatitis was induced by various chemicals such as carbon tetrachloride (31.25 μL/kg, i.p.) or acetaminophen (paracetamol; 600 mg/kg, i.p.) in mice and D(+)‐galactosamine (188 mg/kg, i.p.) in rats. When treated with A. sessilis (300 mg/kg, p.o.) at 2, 6 and 10 h, a reduction in elevation of serum glutamate oxaloacetic transaminase (SGOT) and glutamate pyruvic transaminase (SGPT) levels could be observed at 24 h after administration of the three hepatotoxins. These serological observations were also confirmed by histopathological examinations including centrilobular necrosis, eosinophilic bodies, pyknotic nuclei, microvesicular degeneration of hepatocytes and others. The liver microscopic examination showed a noted improvement in groups receiving A. sessilis. All pharmacological and histopathological effects were compared with observations using the hepatoprotective Chinese herb, Bupleurum chinense (Family Umbelliferae). It was confirmed that A. sessilis has hepatoprotective effects against liver injuries induced by hepatotoxins with different mechanisms.
An approach to the genus Tanacetum L. (Compositae): Phytochemical and pharmacological review
Authors: Abad M. J. , Bermejo P. , Villar A.
Published: October 2006

In view of the importance in folk medicine of some species of Tanacetum L. (Compositae), e.g. T. parthenium, this paper reviews reports of the past two decades on their phytochemistry and pharmacological actions. The facets of phytochemical composition to be reviewed concern mainly the compounds with a chemosystematic interest in the tribe: terpenoids, especially sesquiterpenes and sesquiterpene lactones and flavonoids. The pharmacological activities which make it possible to corroborate their use as a herbal remedy have also been reviewed.
Palbinone, a novel terpenoid from Paeonia albiflora: A potent inhibitory activity on human monocyte interleukin‐1β
Authors: Kadota Shigetoshi , Basnet Purusotam , Terashima Satoshi , Li Jian‐Xin , Namba Tsuneo , Kageyu Akira
Published: October 2006

Palbinone, a novel terpenoid from the roots of Paeonia albiflora, has a very strong inhibitory activity on the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) linked 3α‐hydroxysteroid dehydrogenase (3α‐HSD) of rat liver cytosol and showed a significant inhibitory activity on human monocyte interleukin‐1β, a polypeptide which is though to play an important role in inflammation. In contrast the enzymes cyclooxygenase (CO), thromboxane A synthase (TX) and 5‐lipoxygenase (LO) were not significantly inhibited by palbinone when it was compared with tenokisicum, indomethacin, imidazole and 2, 3, 5‐trimethyl‐6‐(12‐hydroxy‐5, 10‐dodecadiynyl)‐1, 4‐benzoquinone (AA‐861) as positive controls under similar experimental conditions. The activity of palbinone was highly selective since it inhibited strongly only human monocyte interleukin‐1β and did not show any significant activity on CO, TX and LO.
Studies on the effects of capsaicin on leakage in egg lecithin (Phosphatidyl Choline) liposome membranes in vitro
Authors: Mandal T. K. , Chakraborty B. , De A. K.
Published: October 2006

Capsaicin (8‐methyl‐n‐vanillyl‐6‐nonenamide), caused a concentration dependent leakage of chromate through an egg lecithin (phosphatidyl choline) liposomal preparation. Capsaicin treatment of liposomal suspensions caused a maximum leakage of marker chromate at 20 min and then attained a plateau from 30 min onward. Treatment of liposomes with various concentrations of capsaicin (μg/mL loposomal suspensions) showed that lower concentrations of capsaicin (< 0‐0.1 μg/mL) caused greater chromate leakage than higher concentrations (0.1‐0.5 μg/mL). This dual effect of capsaicin on liposome membrane was accompanied by an increased amount of malondialdehyde formed (an important end product of lipid peroxidation) at lower concentrations (<0.10 μg/mL) than at higher concentrations (0.1‐0.5 μg/mL).
Effects of Olea europaea L. extract on the rat isolated ileum and trachea
Authors: Fehri Badreddine , Mrad Samira , Aiache Jean‐Marc , Lamaison Jean‐Louis
Published: October 2006

The effects of an Olea europaea L. dried leaf extract containing 3.2% of oleuropein were investigated on the rat isolated ileum and trachea. On basal tone rat isolated ileum, Olea europaea L. extract was shown to produce a dual effect characterized by a contraction at low doses (10−7‐10−4g/mL) and a relaxation at high doses (3.10−4‐10−3g/mL). The extract induced contractile effect was found to involve at least histamine, 5‐hydroxytryptamine and thromboxane A2. On precontracted rat isolated ileum, the extract only induced a relaxation that was not modified by nifedipine, diltiazem, dipyridamone, verapamil or papaverine (10−6 M). The effects of the extract were also studied on the rat isolated trachea. On basal tone organs, Olea europaea L. extract did not produce any effect, whereas, when basal tone was raised by acetylcholine (ACh 10−3 M), the drug caused a relaxation (maximal effect 39.01% ± 5.40%) of the response to theophylline; (3.10 ± 10−3M n = 15). It is suggested that the induced relaxation is consecutive to an increase of intracellular 3′5′ cAMP.
Screening of tropical medicinal plants for antiinflammatory activity
Authors: Recio M. C. , Giner R. M. , Mánez S. , Rios J. L. , Marston A. , Hostettmann K.
Published: October 2006

The antiinflammatory activity of different extracts from 16 tropical plant species belonging to 15 different families has been determined. They were administered topically on TPA‐induced mouse ear oedema and orally on carrageenan‐induced mouse paw oedema. In the latter, extracts from Diospyros leucomelas, Erythrospermum monticolumn, Ficus polita, Heteromorpha trifoliata, Hypericum lalandii, Kirkia acuminata, Pterocarpus angolensis and Zanha africana significantly reduced the oedema 3 h after carrageenan injection. All the extracts were considerably active when assayed topically with only three exceptions.
Multivariate Parametrization of Amino Acid Properties by Thin Layer Chromatography
Authors: Eriksson Lennart , Jonsson Jörgen , Sjöström Michael , Wold Svante
Published: October 2006

48 amino acids (20 coded and 28 non‐coded) were multivariately characterized by seven thin layer chromatography variables and two theoretical variables (molecular weight and side chain van der Waals volume). Principal components analysis (PCA) of the original 48 × 9 data matrix, resulted in two significant principal components which together described 88% of the variance in the data. The relationship between these principal components and the earlier estimated z‐scales for coded amino acids was investigated. In addition, it was found that the principal components had a predictive capacity similar to the z‐scales, when compared in a peptide QSAR of a series of bradykinin potentiating pentapeptides modified with only coded amino acids. Thus it is shown that TLC is a rapid technique suitable for the parametrization of amino acids.
Inhibition of Carbonic Anhydrase by Substituted Benzenesulfonamides. A Reinvestigation by QSAR and Molecular Graphics Analysis
Authors: Carotti Angelo , Raguseo Cosima , Campagna Francesco , Langridge Robert , Klein Teri E.
Published: October 2006

The inhibition of Bovine Carbonic Anhydrase B (BCA‐B) by an appropriately designed set of meta‐ and para‐substituted benzenesulfonamides was studied. From the results the following quantitative structure‐activity relationship was derived: log 1/Ki = 0.95 σ + 0.54 π – 0.35 B5,3 + 6.29. In this equation Ki is the inhibition constant, σ is the Hammett constant, π is the hydrophobic parameter and B5,3 is the sterimol steric parameter for the meta substituents. Using this equation we designed, synthesized and successfully predicted Ki for a new congener intended to maximize the inhibitory potency (1/Ki). The interactions involved in the enzyme‐inhibitors binding as suggested by the correlation equation, have been tentatively interpreted using computer built 3‐D molecular models based on the published X‐ray crystallographic coordinates of the free and inhibitor‐bound carbonic anhydrase. The results from our analyses have been compared with those obtained in some previous QSAR analyses.
EVE, a Distance Based Approach for Discriminating Nonlinearly Separable Groups
Authors: Benigni Romualdo
Published: October 2006

We previously demonstrated that the Euclidian distances between objects provide a description of the data field, which is more flexible and versatile than the description provided by the original variables, from which the distances were calculated. In fact, the distance matrix also contains, together with the information carried by the original variables, information about the relationships between objects. These properties of the Euclidian distances permit the separation of both linearly and nonlinearly separable groups. In this paper, the findings of our previous work were implemented in a computer program (EVE), which permits: a) the identification of the variables that separate two classes; b) the construction of discriminant equations. The potential of EVE was demonstrated by applying it to a number of simulated cases, as well as to a real QSAR problem (antiparasitic activity of Praziquantel and its analogues), where the active chemicals are embedded in the group of the inactives.
ADMET Property Prediction: The State of the Art and Current Challenges
Authors: Gola Joelle , Obrezanova Olga , Champness Ed , Segall Matthew
Published: October 2006

In this article, we review recent developments in the prediction of Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) properties by Quantitative Structure–Activity Relationships (QSAR). We consider advances in statistical modelling techniques, molecular descriptors and the sets of data used for model building and changes in the way in which predictive ADMET models are being applied in drug discovery. We also discuss the current challenges that remain to be addressed. While there has been progress in the adoption of non‐linear modelling techniques such as Support Vector Machines (SVM) and Bayesian Neural Networks (BNNs), the full advantages of these ‘machine learning’ techniques cannot be realised without further developments in molecular descriptors and availability of large, high‐quality datasets. The largest pharmaceutical companies have developed large in‐house databases containing consistently measured compound properties. However, these data are not yet available in the public domain and many models are still based on small ‘historical’ datasets taken from the literature. Probably, the largest remaining challenge is the full integration of predictive ADMET modelling in the drug discovery process. Until in silico models are applied to make effective decisions in a multi‐parameter optimisation process, the full value they could bring will not be realised.
Cr and Hg toxicity assessed in situ using the structural and functional characteristics of algal communities
Authors: Singh A. K. , Rai L. C.
Published: October 2006

The toxicity of mercury and chromium on algal community structure have been assessed using in situ N2ase activity, pigment diversity, autotrophic index, and 14C uptake of algae. The location was in the river Ganga and controlled ecosystem pollution experiment enclosures were used. Maximum inhibition of algal number was observed at 0.8 μg Hg mL−1 followed by 8.0 μg Cr mL−1. Unicellular forms, except for Anorthoneis excentrica, were very sensitive to test metals used. The decline in algal number was concentration dependent and metal specific at generic and species levels. Complete elimination of three and six species was observed respectively at 8.0 μg Cr mL−1 and 0.8 μg Hg mL−1 after 12 days' exposure. Likewise, a concentration‐dependent and metal‐specific increase in autotrophic index and pigment diversity of phytoplankton was recorded for Hg and Cr. Inhibition of 14C uptake of phytoplankton in Ganga water was almost equal (79%) at 0.8 μg Hg mL−1 and 8.0 μg Cr mL−1 (78%). Although complete inhibition of in situ N2ase was observed at 0.8 μg Hg mL−1, it was only 80% with 8.0 μg Cr mL−1. Our study suggests that heavy metals inhibit both structural and functional variables of phytoplankton in field microcosms. Hence this technique seems to hold potential for the biomonitoring of heavy metal toxicity in the field.
Evaluating three simple methods to assess the microbial quality of drinking water in Indonesia
Authors: Kromoredjo P. , Fujioka R. S.
Published: October 2006

Three simple microbial tests [H2S paper strip, lauryl tryptose broth + 4‐methyl‐umbelliferyl‐β‐d‐glucoronide (LTB + MUG), Colilert] were used to assess the microbial quality of water in the distribution system of Banjarmasin, the capital city of South Kalimantan Province (Borneo), Indonesia. Martapura River, the source of the drinking water, is contaminated with total coliform, Escherichia coli, and hydrogen sulfide producing bacteria. However, this water is treated and chlorinated to a residual of 1.0 mg/L before it is distributed to the city. No coliform or hydrogen sulfide producing bacteria were detected in the chlorinated water leaving the treatment plant. A total of 46 water samples were obtained from public taps at three subdistricts in the city located 2–8 km from the water treatment plant. Residual chlorine levels ranging from 0.0 to 0.8 mg/L were detected in the 46 drinking water samples. Of these, 47.8% was positive by the H2S test and the Colilert test. The LTB + MUG test was positive in 45.7% of these 46 water samples. Virtually all (96–100%) of the coliform positive samples contained E. coli. The H2S test appears to be a reliable, inexpensive, and especially suitable to assess the microbiological quality of drinking water in Indonesia.
Toxicity screening of phenol using microtox
Authors: Ghosh S. K. , Doctor P. B.
Published: October 2006

The EC50 values of phenol (50% decrease in light output) have been determined by using the MicrotoxTM system and Photobacterium phosphorium as the sensor organism. Effects of various physical and chemical factors like pH, temperature, time, aging, etc., have been worked out. The EC50 values of phenol (mg/L) at 15°C have been found to be 23.28, 25.61, and 26.01 for 5‐, 15‐, and 30‐min incubation periods, respectively. It is also suggested that factors like pH, aging of bacteria, salt concentration, etc., should be indicated when stating EC50 values to facilitate comparison with results obtained by other workers.
A bloom of Prymnesium parvum Carter in a small coastal inlet in Dragsfjärd, southwestern Finland
Authors: Lindholm Tore , Virtanen Teija
Published: October 2006

A bloom of Prymnesium parvum Carter and fish mortality occurred in June 1990 in a coastal inlet in Dragsfjärd, southwestern Finland. The highest concentrations of P. parvum exceeded 50,000 cells/mL. Chemical analyses done in early July during the decline of the bloom showed total phosphorus values of 30–36, total nitrogen values of 710–810, and chlorophyll a concentrations below 10μg/L. The levels were about 50% lower in the archipelago outside the inlet where low numbers of P. parvum occurred. Flagella of living P. parvum cells showed an autofluorescence, which may be of diagnostic value.
Interaction effect, food effect, and bioaccumulation of cadmium and chromium for the system daphnia magna‐chlorella ellipsoidea
Authors: Kungolos Athanassios , Aoyama Isao
Published: October 2006

In this study Chlorella ellipsoidea was used as food for Daphnia magna in order to investigate the food effect on the toxicity. The effect was found to vary depending on the toxicant used, on the concentration of the toxicant in the water, and on the duration of the exposure. We conducted acute mortality tests with a duration of 1–4 days. Cadmium and chromium were used as toxicants. The toxicity increase due to the presence of food was more prominent for Cr than for Cd.

We also investigated the interaction effect of the two heavy metals on Daphnia in the absence of food. That effect was found to be either additive or antagonistic depending on the concentrations used. There were more cases of addition than antagonism.

Finally we checked the toxicant content in the body of Daphnia after two days of exposure. It was found that the increased bioaccumulation lead to the death of the animals. The bioaccumulation experiments gave us data to support assumptions concerning the food effect and the interaction effect. © 1993 John Wiley & Sons, Inc.
Cyst‐based toxicity tests. VII. Evaluation of the 1‐h enzymatic inhibition test (fluotox) with Artemia nauplii
Authors: Espiritu E. Q. , Janssen C. R. , Persoone G.
Published: October 2006

The newly developed 1‐h enzymatic inhibition bioassay (Fluotox) was applied to toxicity testing with the larvae of the brine shrimp Artemia. The method consists of visual observation of in vivo inhibition of an enzymatic process using a fluorigenic enzyme substrate. The 1‐h Fluotox test and the conventional 24‐ and 48‐h LC50 toxicity tests were conducted in parallel on 8 different organic and inorganic chemicals. A good correlation was found between the 1‐h EC50 and the 24‐ and 48‐h LC50 data with r2 s of 0.94 and 0.93 for each respective regression. Addition of the enzyme substrate did not influence the toxicity of the chemicals in the 24‐ and 48‐h tests. The repeatability of the Fluotox test compares favorably with that of the conventional 24‐h acute test; coefficients of variation (CV) ranged from 8 to 34% and from 1 to 39%, respectively.

Investigations on the applicability of the Fluotox procedure for testing in brackish waters revealed that lowering the salinity from 35 to 15 ppt did not affect the fluorescence and mortality responses in the controls.

The same decrease in salinity had no significant influence on the 1‐h EC50s except for NaLS and acetic acid. The ratio between the 1‐h EC50s at 35 and 15 ppt varied from 0.46 to 2.18 depending on the chemical.

However, the same decrease in salinity significantly influenced (p < 0.05) the 24‐h LC50s (except NaPCP) and the 48‐h LC50 (except formaldehyde). In general, the ratio of the LC50 values obtained at 35 and 15 ppt varied from 0.30 to 2.21 and from 0.48 to 2.53 for the 24‐ and 48‐h exposures, respectively.

In view of several inherent advantages such as rapidity, experimental simplicity, low cost of performance, and the use of dry cysts as biological starting material (which eliminates the maintenance of live stock culture) the 1‐h Artemia Fluotox test offers promising potential for numerous ecotoxicological applications. © by John Wiley & Sons, Inc.
Species distribution and temperature relations of coliform populations from uninhabited watershed areas
Authors: Niemelä Seppo I. , Niemi R. Maarit
Published: October 2006

Fifty‐seven water samples in all were collected in a northern (latitude 69° N) and in a southern (latitude 61° N) region from waters in the “natural state.” Coliform populations were studied by collecting random isolates of typical sheen colonies from Endo LES 35° C cultivations. The maximum growth temperatures of 607 strains were measured. Identification of 372 isolates was attempted by using the API 20EC and 20E systems. Eleven species were found—seven of them common to both regions. Twenty‐nine percent of the strains could not be identified. The most frequent species was Serratia fonticola (26% of all strains tested), the second was Hafnia alvei (14%), and the third Enterobacter cloacae (13%; only encountered in the north). The strains able to grow at or above 44. 5°C were identified as Escherichia coli. In the southern region, environmental coliforms (S. fonticola and H. alvei) so completely outnumbered E. coli that it was met only once among the 438 total coliform isolates, whereas 23% of the isolates from the northern region were E. coli. Typical pipeline/biofilm coliform types were not found, with the exception of numerous E. cloacae strains in the most remote lake samples collected and one Klebsiella oxytoca in a brook. The fecal coliforms (all of them E. coli) were concluded to be of recent animal origin. The standard fecal coliform analysis was estimated to function extremely well in the pristine waters of our subarctic climate. The total coliform analysis has no indicator value under these circumstances.
Bioconcentration, chemical fate, and environmental effects testing under section 4 of the Toxic Substances Control Act
Authors: Walker John D.
Published: October 2006

As of December 31, 1988, the U.S. Environmental Protection Agency (EPA) had published 49 Federal Register (FR) notices acknowledging, proposing, or requiring development of bioconcentration, chemical fate, or environmental effects testing data under Section 4 of the Toxic Substances Control Act (TSCA). These FR notices included 5 Decisions Not to Test (DNTs) that acknowledged industry testing, 19 Notices of Proposed Rulemaking (NPRs) that proposed testing by industry, 9 Notices of Final Rulemaking (NFRs), and 2 Consent Orders (COs) that required industry testing as well as 7 proposed and 7 final Negotiated Testing Agreements (NTAs). Two bioconcentration, 12 chemical fate, and 28 environmental effects tests were submitted to the EPA by industry as a result of issuing DNTs. Industry completed 3 bioconcentration, 86 chemical fate, and 151 environmental effects tests after publication of NTAs. Two bioconcentration, 11 chemical fate, and 14 environmental effects tests were completed as a result of publishing NFRs; 1 chemical fate and 5 environmental effects tests were completed under a CO. As of December 31, 1988, a total of 7 bioconcentration, 110 chemical fate, and 234 environmental effects tests had been completed under TSCA Section 4.
A continuous‐flow method for measuring effects of chemicals on soil nitrification
Authors: Rhodes Albert N. , Hendricks Charles W.
Published: October 2006

Because the productivity of terrestrial ecosystems is directly related to microbial nutrient cycling, understanding the effects of chemical contaminants on soil microbial processes is important. This study examined the effects of two model chemicals—Roundup (glyphosate) and N‐Serve (nitrapyrin)—on nitrifying organisms in static, perfusion, and continuous‐flow culture systems. Experimental concentrations were approximately 1, 10, and 100 × the spot application rate. Both N‐Serve and Roundup were shown to inhibit nitrification in the treated soils. Roundup significantly reduced nitrification at 6.8 and 68 mg g−1 dry soil. N‐Serve (nitrapyrin) completely inhibited nitrification at levels greater than 42 μ g−1 dry soil in all cultural methods.

In comparative studies with static batch and perfusion culture techniques, the continuous‐flow system proved to be both reliable and useful in the culture of nitrifying bacteria. This method provides an alternative to traditional culture techniques in measuring chemical effects on microbial geochemical cycles and provides a new method for use in toxicity testing.
Mutational spectrum of classical galactosaemia in Spain and Portugal
Authors: Gort L. , Boleda M. D. , Tyfield L. , Vilarinho L. , Rivera I. , Cardoso M. L. , Santos‐Leite M. , Girós M. , Briones P.
Published: October 2006

Classical galactosaemia is an autosomal recessive inherited metabolic disorder due to deficient galactose‐1‐phosphate uridyltransferase (GALT). Over 180 different base changes and disease‐causing mutations have been reported in the GALT gene. Mutation p.Q188R was found to be the most common molecular defect among caucasian classical galactosaemia patients. We have characterized the spectrum of GALT mutations in a group of 51 Spanish families and 32 Portuguese families with this disease. p.Q188R is also the most prevalent mutation in the Spanish and Portuguese population, accounting for 50% and 57.8% of galactosaemic alleles, respectively. An additional 15 mutations were also identified in Spanish patients, four of which were novel: p.D28H, p.S181A, c.658dupG and c.377+53_1059+87del. In the Portuguese population, 11 different mutations were found, three of which were novel: p.R33H, p.P185S, and p.S192G. The differences observed between the genotypes identified in Portuguese and Spanish galactosaemic populations are notable. Only mutations p.Q188R, p.R148Q and c.820+13g>a were identified in both populations. In spite of the geographical proximity of Spain and Portugal, it seems that they have received genetic influences from different populations. The repeated migrations that occurred in the Iberian Peninsula throughout centuries may explain such variability.
Copying clinic letters to patients: a survey of patient attitudes
Authors: Liapi A , Robb P J , Akthar A
Published: October 2006

Guidance from the Department of Health, published in 2000, stated that, ‘as a matter of right’, communications between clinicians would be copied to patients. In further guidance, the department indicated that, from April 2004, patients would receive copies of correspondence exchanged between healthcare professionals. There has been little research on this issue, and the few existing publications have come from the hospital psychiatric clinic setting.

We examined the attitudes of 100 patients attending an ENT clinic as well as those of 100 parents of children attending a paediatric ENT clinic in a general hospital out-patient setting. At the end of consultations, patients or parents were invited to take part in the survey by completing a short questionnaire. Forty-three per cent of the adult patients and 44 per cent of the parents requested a copy of the clinic letter. These people were followed up by a telephone survey, three weeks after the copy of the clinic letter to the general practitioner was posted to the patient or parent. Eighty-one per cent of the patients and 77 per cent of the parents were successfully contacted for the follow-up telephone survey. Sixty per cent of the adults and 77 per cent of the parents reported that the copy of the clinic letter was helpful. There were no differences in responses between the adult patient and paediatric patient groups.

In this study, less than half of both groups requested a copy of the ENT clinic letter to their general practitioner. To follow Department of Health guidance and copy the letter without patient consent is arguably contradictory to best practice and also to the concept of patient choice. There are significant financial implications in adopting the departmental guidance. We propose patients should be offered a copy of their clinic letter on request.
Electromyography of the cricoarytenoid unit during supracricoid laryngectomy with a cricohyoidoepiglottopexy procedure
Authors: Nakayama M , Hirose H , Okamoto M , Miyamoto S , Yokobori S , Takeda M , Seino Y , Kawashima E
Published: October 2006

Two patients who received supracricoid laryngectomy with cricohyoidoepiglottopexy to treat laryngeal cancers, underwent intra-operative electromyography analysis. After the lesion was removed and the electrodes were inserted into the remaining intrinsic laryngeal muscles, the depth of anaesthesia was carefully reduced. Gentle tactile stimulations were applied to the pharynx to trigger the reflex movement of the remaining arytenoids. Recordings were made when reflex movement was achieved.

Case one: Electromyography (EMG) of the remaining arytenoid demonstrated clear phase differences indicating reciprocal activities between the adductor group (lateral cricoarytenoid muscle, interarytenoid muscle) and the abductor muscle (posterior cricoarytenoid muscle). Case two: EMG of the remaining arytenoid demonstrated reciprocal activities between the interarytenoid muscle and the posterior cricoarytenoid muscle. Activity of the lateral cricoarytenoid muscle was not evident because the muscle was excised during removal of the paraglottic space. Mobility of the arytenoid was attributed to interaction between the interarytenoid muscle and posterior cricoarytenoid muscle. Reciprocal interaction between the interarytenoid muscle and posterior cricoarytenoid muscle alone is also capable of maintaining post-operative laryngeal functions after supracricoid laryngectomy with cricohyoidoepiglottopexy.