Rhesus factor

PH Past history personal history pinhole poor health Rh Rhesus factor in blood... 

In the Rh system (not shown), proteins on the surface of the erythrocytes act as antigens. These are known as rhesus factors, as the system was first discovered in rhesus monkeys. 

Rhesus factor One of the genetically determined factors on the surface of blood cells. Can be responsible for immune rejection of a foetus in pregnancy. 

Nonhuman primates are often the nonrodent species of choice for safety assessment studies. There are over 500 species of nonhuman primates that differ widely from each other in size and physical characteristics. Most of the monkeys used in experimental research belong to the suborder Anthropoidea and especially to the superfamilies of Ceboidea (marmoset, squirrel monkey) and Cercopitcoidea (macaque, papio species, rhesus). These have been popular because of (1) assumed better concordance of effects seen to those in man and (2) smaller weights (and therefore reduced compound requirement). However, predominant factors leading to a decision whether or not to select primates as the nonrodent species for safety evaluation are summarized as follows (Hobson, 2000). 

The authors noted that, in comparison with the scaling factor, the traditional 10-fold factor contains an additional extrapolation factor for possible additional toxicokinetic or toxicodynamic variability apart from the basal metabolic rate scaling. This additional factor, which can be interpreted as the traditional 10-fold factor divided by the scaling factor, ranges from approximately 1.5 for the mouse (10/7= 1.4) to approximately 6 for the rhesus monkey (10/1.6 = 6.3). The authors considered that the additional factor thus comprises levels of safety, which are currently nonuniform, and this inhomogeneity is not supported toxicologically. 

Effects of early environmental adversity on HPA mediation of neurodevelopment have also been demonstrated in non-human primates (Coplan et al., 1995). Corticotropin-releasing hormone (CRH) intracerebro-ventricular administration in rhesus monkeys that had been separated from their mothers produced behavioral inhibition and increases in ACTH and cortisol. Coplan et al (1995) presented evidence for persistently elevated cerebrospinal fluid concentrations of corticotropin-releasing factor (CRF) in grown macaques that had been reared by mothers in unpredictable environmental conditions. Further studies in adversely reared adult monkeys demonstrated an inverse relationship between mean CRF concentrations and GH response to clonidine (Coplan et al., 2000). In light of evidence that reduced GH response to clonidine has been shown in other anxiety disorders (Charney and Bremner, 1999), Coplan et al. (2000) hypothesize that GH response to clonidine may inversely reflect trait-like increases of central nervous system CRF activity. Data linking childhood anxiety to growth deficits are consistent with this view (Pine et al., 1996). Activity, of the HPA axis, as related to early environmental... 

Lower incidence of heart disease has also been reported in populations consuming large amounts of soy products. Lowering of cholesterol is probably the best-documented cardioprotective effect of soy. ° Soy protein incorporated into a low-fat diet can reduce cholesterol and LDL-cholesterol concentrations and the soy isoflavones are likely to contribute to these effects. Soy isoflavones have been reported to improve cardiovascular risk factors in peripubertal rhesus monkeys, and inflammatory markers in atherosclerotic, ovariecto-mized monkeys. The potential role of phytoestrogens, including isoflavonoids, as cardioprotective agents has been extensively reviewed." ... 

Anthony MS, Clarkson TB, Hughs CL Jr, Morgan TM, Burke GL. Soybean isoflavones improve cardiovascular risk factors without affecting the reproductive system of peripubertal rhesus monkeys. J. Nutr. 126, 43-50, 1996. 

Suomi SJ Factors affecting responses to social separation in rhesus monkeys, in Animal Models in Human Psychobiology. Edited by Serban G, Khng A. New York, Plenum, 1976, pp 9-26... 

Vandenbergh JG Vessey S (1968) Seasonal breeding of free ranging rhesus monkeys and related ecological factors. J Reprod Fertil, 15 71-79. 

Dunwiddie CT, Nutt EM, Vlasuk GP, Siegel PDS, Schaffer LW. Anticoagulant efficacy and immunogenicity of the selective factor Xa inhibitor antistasin following subcutaneous administration in the rhesus monkey. Thromb Haemostas 1992 67 371-376. 

Tucker, C.E., Chen, L.S., Judkins, M.B., Farmer, J.A., Gill, S.C. and Drolet, D.W. (1999) Detection and plasma pharmacokinetics of an anti-vascular endothelial growth factor oligonucleotide-aptamer (NX 1838) in rhesus monkeys. J. Chromatogr. B., 732, 203-212. 

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