scholarly journals Measurement of water-holding properties of fibre and their faecal bulking ability in man

1983 ◽  
Vol 50 (3) ◽  
pp. 539-547 ◽  
Author(s):  
M. A. Eastwood ◽  
J. A. Robertson ◽  
W. G. Brydon ◽  
Dorothy MacDonald
Keyword(s):  
Flow Rate ◽  
Water Flow Rate ◽  
Gum Arabic ◽  
Dietary Supplementation ◽  
Suction Pressure ◽  
Stool Weight ◽  
In Vitro Methods ◽  
Cereal Bran ◽  
Water Holding

1. Experiments to measure the effect of a fibre source in the diet on stool bulk are difficult and lack precision. In vitro methods which would identify fibre sources that are effective for clinical and epidemiologic use would be valuable. One important property of fibre which influences the ability of fibre to increase stool weight is its water-holding capacity (WHC).2. WHC was measured using centrifugation, filtration, suction pressure and water flow-rate techniques using fibre concentrates of potato, cereal bran and gum arabic.3. Dietary supplementation of three preparations of potato fibre (20 g/d) had no significant effect on stool weight but 16 g bran/d increased stool weight from 107 (SE 44) g/d to 174 (SE 51) g/d.4. The effects of these fibres on stool weight can be related to the nature of the water-holding properties of fibre rather than absolute WHC.

scholarly journals A method to measure the water-holding properties of dietary fibre using suction pressure

1981 ◽  
Vol 46 (2) ◽  
pp. 247-255 ◽  
Author(s):  
J. A. Robertson ◽  
M. A. Eastwood
Keyword(s):  
Dietary Fibre ◽  
Gum Arabic ◽  
Water Soluble ◽  
Suction Pressure ◽  
Physiological Conditions ◽  
Fibre Concentration ◽  
Vegetable Fibre ◽  
Water Holding ◽  
Fibre Matrix

1. Water-holding capacity (WHC) of dietary fibre is usually considered as the amount of water held but the manner in which water is held by the fibre matrix may be more relevant in understanding the role of fibre in nutrition.2. A method used to determine WHC under physiological conditions has been adapted to determine how strongly water is held by fibre. Solutions of compounds, such as polyethylene glycol, of known osmotic potential are used to generate a suction pressure across a dialysis membrane containing a fibre sample. The WHC at each suction pressure can then be determined.3. The method can be applied to water-soluble and water-insoluble sources of fibre. Fibre sources studied included potato fibre concentrate, bran and gum arabic.4. Results are comparable to other similar systems of WHC measurement for gels and suggest that vegetable fibre has water-holding properties more akin to a true gel than bran. Bran has very poor water-holding properties.5. Differences in WHC between fibre sources are more apparent if WHC is considered as fibre concentration (g fibre/g water).6. Differences in the water-holding properties could be important in determining fibre activity in the gut.

Anti-amnesic activity screening of the seed ethanol extracts of Turkish Paeonia taxa by in vitro methods

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
D Sevim ◽  
FS Senol ◽  
I Orhan ◽  
B Şener ◽  
E Kaya
Keyword(s):  
In Vitro Methods ◽  
Activity Screening ◽  
Ethanol Extracts

Analysis of antidepressant properties of some Papaver species by in vivo and in vitro methods

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
OML Bayazeid ◽  
F Yalcin ◽  
M İlhan ◽  
H Karahan ◽  
E Kupeli-Akkol ◽  
...  
Keyword(s):  
In Vitro Methods

The Effects of Some Synthetic Compounds on In Vitro Fibrinolytic Activity Measured by Different Methods and the Relevance to Activity In Vivo

1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim
Keyword(s):  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Fibrinolytic Activity ◽  
Synthetic Compounds ◽  
In Vitro Methods ◽  
Narrow Concentration Range

SummaryThe activity of several synthetic compounds, rated from good to poor (or inactive) fibrinolytic activators, has been assessed by two different commonly-used in vitro methods. Compounds shown to be active over a narrow concentration range in the hanging clot test were shown to be inhibitors of plasmin and trypsin in the casein-olytic test. The inhibitory activity of these compounds was shown to increase with increasing substrate concentration and apparent activity in the hanging clot test. Possible explanations and relevance of these observations are discussed.

A Call for a European Prohibition of Monoclonal Antibody Production by the Ascites Procedure in Laboratory Animals

1998 ◽  
Vol 26 (4) ◽  
pp. 523-536
Author(s):  
Coenraad F.M. Hendriksen
Keyword(s):  
Monoclonal Antibody ◽  
Laboratory Animals ◽  
Induction Method ◽  
Therapeutic Application ◽  
Monoclonal Antibody Production ◽  
In Vitro Methods ◽  
Appeals Process ◽  
Core Facilities ◽  
Mab Production

Monoclonal antibodies (mAbs) are particularly valuable in therapeutics and research. Unfortunately, one of the most familiar methods of producing mAbs, the ascites induction method, causes pain and distress to the animals used. In most cases, non-animal or in vitro alternatives can be employed to reduce or eliminate the use of animals for mAb production. Prohibition of the use of animals in the production of mAbs is recommended, except when the replacement in vitro methods prove to be insufficient, and in a limited number of other well-documented cases, such as an exceptional need for an emergency therapeutic application. A total ban on the use of animals for mAb production is impractical and it is imperative that an appeals process should accompany the prohibition. The need for the establishment of core facilities for in vitro mAb production is emphasised.

In Vitro Methods for the Assessment of L-Cysteine Conjugate Toxicity

1994 ◽  
Vol 22 (2) ◽  
pp. 72-80
Author(s):  
Lorraine D. Buckberry ◽  
Harriet J. Adcock ◽  
Jeremy Adler ◽  
Ian S. Blagbrough ◽  
Peter J. Gaskin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Mammalian Species ◽  
Mercapturic Acid ◽  
Assay Method ◽  
Cellular Toxicity ◽  
In Vitro Methods ◽  
Metabolic Route ◽  
Assay Methods ◽  
Chang Liver

L-Cysteine conjugates are normally metabolised via N-acetylation to produce a mercapturic acid. However, a recently identified metabolic route (C-S lysis) may lead to the generation of an unstable thiol which has been demonstrated to be responsible for toxicity in various mammalian species. Human Chang liver cells were challenged with a number of established L-cysteine conjugates. The cellular toxicity of these compounds was determined using a range of assay procedures, which provided differing information, depending on the assay method used. These observations were then investigated in order to establish which system would provide the most reliable indication of C-S lyase toxicity and whether any information on the mechanism of action could be obtained by these assay methods.

In Vitro Toxicology Methods in Risk Assessment

1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase
Keyword(s):  
Risk Assessment ◽  
Hazard Assessment ◽  
Human Health Risk ◽  
In Vitro Test ◽  
In Vitro Methods ◽  
New Concepts ◽  
Vitro Test

The title of this paper is challenging, because the question of how in vitro methods and results contribute to human health risk assessment is rarely considered. The process of risk assessment usually begins with hazard assessment, which provides a description of the inherent toxicological properties of the chemical. The next step is to assess the relevance of this to humans, i.e. the human hazard assessment. Finally, information on exposure is examined, and risk can then be assessed. In vitro methods have a limited, but important, role to play in risk assessment. The results can be used for classification and labelling; these are methods of controlling exposure, analogous to risk assessment, but without considering exposure. The Ames Salmonella test is the only in vitro method which is incorporated into regulations and used widely. Data from this test can, at best, lead to classification of a chemical with regard to genotoxicity, but cannot be used for classification and labelling on their own. Several in vitro test systems which assess the topical irritancy and corrosivity of chemicals have been reasonably well validated, and the results from these tests can be used for classification. The future development of in vitro methods is likely to be slow, as it depends on the development of new concepts and ideas. The in vivo methods which currently have reasonably developed in vitro alternatives will be the easiest to replace. The remaining in vivo methods, which provide toxicological information from repeated chronic dosing, with varied endpoints and by mechanisms which are not understood, will be more difficult to replace.

scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

Studies of Metabolism Mediated Mutagenicity In Vitro

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 243-250
Author(s):  
Dag Jenssen ◽  
Lennart Romert
Keyword(s):  
Cell Lines ◽  
Biological Effects ◽  
Animal Experiments ◽  
Culture Technique ◽  
Organ Perfusion ◽  
Isolated Cells ◽  
Toxicological Effect ◽  
In Vitro Methods

To understand the cause of the biological effects of xenobiotic metabolism in mammals, investigators have traditionally performed animal experiments by comparing the results of biochemical methods, such as measurement of enzyme activity analysis of the metabolites produced, with the observed toxicological effect. This article deals with in vitro methods for genotoxicity combined with drug metabolising preparations at the organelle, cell or organ levels, as exemplified by microsome preparations, isolated cells/cell lines and organ perfusion systems, respectively. The advantage of some of these methods for studying metabolism-mediated mutagenicity is that the measured endpoint reflects not only the bioactivating phase I reactions, but also the detoxifying phase II reactions, and the transfer of the non-conjugated reactive metabolites to other cells and their ability to cause mutations in these cells. In vivo, all these events are important factors in the initiation of cancer. A mechanistic advantage of the methods for metabolism-mediated mutagenicity in vitro is that the relevance of the different steps in metabolism for the mutational events can seldom be investigated in an in vivo assay. Furthermore, human studies can easily be performed using the co-culture technique with isolated human cells or cell lines.

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