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Biomedical subjects

G Blunden

Publications and source records attributed to G Blunden.

At least 19 recordsLinked to original sources

Some effects of Salvia aegyptiaca L. on the central nervous system in mice.

Salvia aegyptiaca L. is used for treating various unrelated conditions that include nervous disorders, dizziness, trembling, diarrhoea and piles. This work examines some effects of the crude acetone and methanol extracts of the plant given at single oral doses of 0.25, 0.5, 1 or 2 g/kg, on the central nervous system (CNS) in mice. The extracts were also tested for anti-inflammatory and antipyretic actions. Several models of nociception have been used to examine the analgesic effect of the extract. In treated mice, the extracts caused dose-related inhibition of acetic acid-induced abdominal constriction, and significantly reduced formalin-induced pain. Treatment with the extracts at doses of 0.5 and 1 g/kg significantly increased the reaction time in the hot-plate test. In treated mice both extracts caused significant and dose-related impairment of the sensorimotor control and motor activity. Treatment with both extracts did not significantly affect the rectal temperature of normothermic mice. The methanol extract (0.5 and 1.0 g/kg) did not affect the rectal temperature of hyperthermic mice, but the acetone extract was effective in significantly reducing the rectal temperature of hyperthermic mice, 0.5 and 1 h after administration of the extract at doses of 0.25-2 g/kg. It is concluded that the crude methanol and acetone extracts of S. aegyptiaca have CNS depressant properties, manifested as antinociception and sedation. Both extracts have some anti-inflammatory and antipyretic actions. On the whole, the acetone extract appeared to be slightly more effective than the methanol extract in this regard.

Acetone↗

Central nervous system activity of Leucas inflata Benth. in mice.

The analgesic activity of the methanol and acetone extracts of Leucas inflata L. (family Labiatae) was evaluated in mice using different experimental models. The effect of the two extracts on pentobarbitone-sleeping time, motor activity, sensorimotor coordination, carrageen induced inflammation, and brewer's yeast-induced pyrexia has also been investigated. The two crude extracts have been phytochemically analyzed and some constituents isolated and characterized. These included stigmasterols, a chromone and coumarins. Extracts of L. inflata L., given at single oral doses of 0.25, 0.5, 1.0 or 2.0 g/kg, significantly and dose-dependently, reduced formalin-induced pain, acetic acid induced abdominal constrictions and increased the reaction time in the hot-plate test. Both extracts caused significant and dose-related impairment in the sensorimotor control and ambulatory and total motor activity of treated mice. Both extracts exhibited anti-inflammatory action by reducing paw edema of treated mice. The extracts did not significantly affect the rectal temperature of normothermic mice. However, they were effective in preventing Brewers yeast induced pyrexia. It is concluded that the crude methanol and acetone extract of L. inflata has CNS depressant properties, manifested as antinociception and sedation. Both extracts have anti-inflammatory and antipyretic actions.

Analgesics↗

Betaine distribution in the Malvaceae.

Aerial parts of 26 taxa, distributed in 18 genera and all 5 tribes of the Malvaceae have been examined for the presence of betaines. Glycinebetaine was obtained in high yield (0.5-4.6%, dry weight) from all the plants studied, except Abelmoschus moschatus, in extracts of which glycinebetaine was not detected. Trigonelline was recorded for 16 of the plants tested, but the yields were low (0.005-0.07%, dry weight). Roots and flowers of a few of the species were also examined for betaines. The same compounds as those found in the aerial parts were usually detected, but the glycinebetaine contents of the roots and flowers were considerably lower.

Betaine↗

Betaine distribution in the Bromeliaceae.

Aerial parts of 38 taxa, distributed in 21 genera and all three subfamilies of the Bromeliaceae have been examined for the presence of betaines. Glycinebetaine and trigonelline were isolated from all the plants studied, although the yields of both compounds were low. For glycinebetaine, values (based upon dry weight) varied from 0.0004% for Pitcairnia corallina to 0.087% for Tillandsia usneoides. Trigonelline levels varied from 0.0003 to 0.022%; the highest yields were recorded for Billbergia rubicunda (0.022%) and Vriesia splendens (0.020%).

Journal Article↗

Professional education for the cancer care nurse in England and Wales: a review of the evidence base.

The third European Commission action plan to combat cancer recognized the need to develop effective continuing and in-service training programmes for doctors, nurses and other healthcare professionals. A literature review and course documentary analysis commissioned by the English National Board for Nursing, Midwifery and Health Visiting Education (ENB) in 1997 found that, within their initial training, nurses in England and Wales are seldom adequately prepared to work with cancer sufferers; that very few nurses undertake subsequent specialist training in cancer care; that up to half the places available on specialist training programmes remain unfilled at any one time; and that, 3 months after such training, studies showed that competence has again decreased. As post-qualifying continuing and in-service education for nurses in their specialist areas is not yet mandatory in the UK, it is unlikely that the objectives of the European Commission's third action plan or those of successive British governments, in successfully combating cancer, will be achieved.

Education, Nursing, Continuing↗

Formaldehyde in the plant kingdom.

Formaldehyde, at its dimedone adduct, formaldemethone, has been detected by thin-layer and high-performance liquid chromatography in extracts of all species tested of marine algae, macrofungi, lichens, bryophytes, pteridophytes, gymnosperms and angiosperms. The yields of formaldehyde recorded in this study varied from 30 microg/g to 4060 microg/g, fresh weight.

Chromatography, High Pressure Liquid↗

The use of HPLC for the detection and quantification of formaldehyde in the pteridophyta.

Formaldehyde, as its dimedone adduct, formaldemethone, has been detected and quantified in all species of Pteridophyta examined. The procedure involved the use of an Hypersil C-18 column, methanol-water (60 : 40 v/v) as the mobile phase and an UV detector set at 258 nm. Quantification was based on peak height. Yields varied from 30 microg/g fresh weight for Polystichum setiferum to 5370 microg/g fresh weight for Selaginella viticulosa.

Chromatography, High Pressure Liquid↗

Are the reductions in nematode attack on plants treated with seaweed extracts the result of stimulation of the formaldehyde cycle?

Soil application to the roots of tomato plants (Lycopersicon esculentum) of a commercially-available alkaline extract of the brown alga, Ascophyllum nodosum, resulted in a significant reduction in the number of second-stage juveniles of both Meloidogynejavanica and M. incognita invading the roots, compared to those of plants treated with water alone. Egg recovery from the seaweed extract treated plants was also significantly lower. The three major betaines found in the seaweed extract (gamma-aminobutyric acid betaine, delta-aminovaleric acid betaine and glycinebetaine) also led to significant reductions in both the nematode invasion profile and egg recovery when applied at concentrations equivalent to those present in the extract. This led to the conclusion that the betaines present in the seaweed extract play a major role in bringing about the observed effects. Treatment of Arabidopsis thaliana plants with seaweed extract also resulted in a significant decrease in the number of females of M. javanica which developed in the roots. Significant reductions in egg recovery were also achieved from plants treated with the seaweed extract and similar effects were produced with the betaines found in the seaweed extract. As the experiments were conducted under monoxenic conditions, it can be concluded that the results obtained with the application of either the seaweed extract or betaines are not dependent on microorganisms associated with the rhizosphere.

Animals↗

Evidence for the anti-hyperlipidaemic activity of the edible fungus Pleurotus ostreatus.

The effects are described of adding either the dried fruiting bodies of the oyster fungus Pleurotus ostreatus, or an ethanolic extract of it, to the diet of normal Wistar male rats and a strain with hereditary hypercholesterolaemia. Addition of the dry oyster fungus to the diet significantly increased, by more than two-fold, the triacylglycerol (TAG) level in the plasma of both groups of rats compared with their respective controls. In contrast, the ethanolic extract did not significantly change TAG levels. Values for total cholesterol and its high- and low-density lipoprotein fractions in the plasma, as well as the calculated atherogenic index, did not show any significant change. Levels of liver cholesterol were significantly lowered by the dried oyster fungus in both hypercholesterolaemic and normal groups of rats, and by the ethanolic extract in normal rats. A significantly increased phospholipid-to-cholesterol ratio in the aortas of both groups of rats, after the administration of either dried oyster fungus or the ethanolic extract of it, suggests a favourable anti-atherogenic effect for both.

Animals↗

Design of sampling plans for mycotoxins in foods and feeds.

The control of the occurrence of mycotoxins in foods and feeds requires effective surveillance and quality control procedures which facilitate the identification and control of the mycotoxin problem respectively. Surveillance and quality control procedures involve a sequence of sampling, sample preparation, and analysis steps; and the integrity of the data produced by these procedures will be determined by the effectiveness of these steps. It is imperative that the sampling step is performed as accurately as possible so that the sample collected is representative of the batch of food or feed under investigation. Needless to say, the collection of a biased sample will completely invalidate the resultant analytical data. Most attempts to develop effective sampling protocols have focused upon the aflatoxins, since the majority of current regulations are concerned specifically with this group of mycotoxins. However, the design of effective sampling protocols has been severely hindered by the highly skewed distribution of the aflatoxins in foods and feeds. Studies already performed indicate that representative samples of commodities, composed of large particles (e.g., corn and oilseed kernels) should be 10 kg in weight, at least, and composed of approximately one hundred incremental samples. Similar studies have indicated that samples of oilseed cakes and meal, however, should be composed of fifty incremental samples which afford a composite sample of approximately 5 kg in weight.

Food Analysis↗

Determination of aflatoxins in groundnut meal by high-performance liquid chromatography: a comparison of two methods of derivatisation of aflatoxin B1.

A comparison has been made between pre-column and post-column derivatisation of aflatoxin B1 (AFB1) during estimation by high-performance liquid chromatography of this toxin in groundnut meal. The effect of the use of different derivatisation reagents on the quantification of aflatoxin B2 (AFB2) has also been evaluated. Both AFB1 and AFB2 were analysed at eight levels of artificial contamination. Five replicate analyses were carried out at each level on both groundnut meal extract (acetone-water, 85:15, v/v) and extraction solvent alone. A statistical evaluation of the results gave limits of detection of 1.1 and 0.3 micrograms/kg for AFB1 and AFB2 respectively, using pre-column derivatisation compared with 1.5 and 0.8 micrograms/kg for the post-column method. Recoveries of over 90% from the spiked groundnut meal extracts were achieved for both derivatisation methods.

Aflatoxin B1↗

Mycotoxins in food.

The presence of mycotoxins in a wide range of foodstuffs can lead to many different toxic conditions in both man and domestic animals. The major fungi responsible for producing these toxins are species of Aspergillus, Penicillium, Fusarium and Alternaria, although other genera are involved as well, for example Claviceps, Diplodia and Arthrinium. An overview is given of the major mycotoxins responsible for illnesses following ingestion of contaminated foods, with particular emphasis on the effects produced in humans. Compounds discussed include the aflatoxins, cyclopiazonic acid, tenuazonic acid, the trichothecenes, zearalenone, wortmannin, fumonisins B1 and B2, patulin, ochratoxin A, diplodiatoxin and diplosporin.

Aflatoxins↗

Steroidal Sapogenins from Tacca leontopetaloides.

Diosgenin and its ring-F-hydroxylated derivatives isonarthogenin {spirost-5-ene-3,27-diol {3beta, 22 R, 25 S)} and isonuatigenin {spirost-5-ene-3,25-diol (3beta, 22 R, 25 S)}, together with the 22,25-epoxyfurost-5-ene isomer nuatigenin {furost-5-ene-3,26-diol-22,25-epoxy (3beta, 22 R, 25 S)}, were identified as the major steroidal sapogenins of the acid hydrolysate of an extract of leaves of TACCA LEONTOPETALOIDES by IR, (1)H-NMR, (13)C-NMR, and mass spectroscopy. A diosgenin ester was isolated which apparently arose by ring closure of a glycosylated furostene during hydrolysis.

Journal Article↗

Configurational assignments to spirostan-3-ols by mass spectrometry.

A study of the degree of water elimination from ions derived from spirostan-3-ols by electron bombardment has shown that the loss is greatest from those ions produced by the 5 beta-spirostan-3 alpha-ols, less from the 5 beta-spirostan-3 beta-ols and the 5 alpha-spirostan-3 alpha-ols, which give losses of the same order of magnitude; and least from the 5 alpha-spirostan-3 beta-ols. The extent of water elimination can be used to help characterise spirostan-3-ols isolated from plant materials.

Chemical Phenomena↗

Ruizgenin, a new steroidal sapogenin diol from Agave lecheguilla.

From the leaves of Agave lecheguilla Torrey, two steroidal sapogenin diols have been isolated. Mass spectral, infra-red and nuclear magnetic resonance data of these two compounds showed them to be (25R)-spirost-5-ene-2 alpha, 3 beta-diol (yuccagenin) and (25R)-5 beta-spirostane-3 beta, 6 alpha-diol. The latter is a new compound to which the trivial name ruizgenin has been given.

Chromatography, Thin Layer↗