scholarly journals Comparison of In Vivo and In Vitro Methods for Blood Feeding ofPhlebotomus papatasi (Diptera: Psychodidae) in the Laboratory

2016 ◽  
Vol 53 (5) ◽  
pp. 1112-1116 ◽  
Author(s):  
David S. Denlinger ◽  
Andrew Y. Li ◽  
Susan L. Durham ◽  
Phillip G. Lawyer ◽  
Joseph L. Anderson ◽  
...  

Abstract Phlebotomus papatasi Scopoli is a medically important insect that has been successfully colonized in the laboratory, and blood feeding is critical for colony propagation. There has been much interest in developing established protocols for in vitro blood-feeding systems. The objective of this study was to determine if a Parafilm membrane and a hog’s gut membrane could be successfully used with in vitro feeding systems. We evaluated percentages ofP. papatasi females that blood fed on different blood-feeding systems (a mouse, a Hemotek feeder, or a glass feeder) used with either a Parafilm or a hog’s gut membrane, with cohorts of 250 and 500P. papatasi females, and with or without external exhalations. For all feeding system combinations, femaleP. papatasi blood fed in higher percentages when in cohorts of 500 individuals and in the presence of exhalations. Higher percentages ofP. papatasi fed on a mouse, but this study also demonstrates thatP. papatasi will readily feed with in vitro feeding systems using a Parafilm membrane or a hog’s gut membrane. This study suggests that femaleP. papatasi may use an invitation effect to blood feed and are attracted to blood sources via chemical olfaction cues, both of which have been characterized in other blood-feeding arthropods. Our study demonstrates that a Parafilm membrane or a hog’s gut membrane, in conjunction with the Hemotek or glass feeder system, is potentially a viable alternative to live rodents to blood feed a colony ofP. papatasi.

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

1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim

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.


1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase

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.


1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 243-250
Author(s):  
Dag Jenssen ◽  
Lennart Romert

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.


Author(s):  
Rasika Reddy ◽  
Howard I. Maibach ◽  
Viswanath Reddy Belum ◽  
Geetanjali Sethi ◽  
Philip Hewitt

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