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1.
Glenn C. Conroy 《International journal of primatology》1987,8(2):115-137
Body-weight estimates of fossil primates are commonly used to infer many important aspects of primate paleobiology, including
diet, ecology, and relative encephalization. It is important to examine carefully the methodologies and problems associated
with such estimates and the degree to which one can have confidence in them. New regression equations for predicting body
weight in fossil primates are given which provide body-weight estimates for most nonhominid primate species in the fossil
record. The consequences of using different subgroups (evolutionary “grades”) of primate species to estimate fossil-primate
body weights are explored and the implications of these results for interpreting the primate fossil record are discussed.
All species (fossil and extant) were separated into the following “grades”: prosimian grade, monkey grade, ape grade, anthropoid
grade, and all-primates grade. Regression equations relating lower molar size to body weight for each of these grades were
then calculated. In addition, a female-anthropoid grade regression was also calculated for predicting body weight infernales
of extinct, sexually dimorphic anthropoid species. These equations were then used to generate the fossil-primate body weights.
In many instances, the predicted fossil-primate body weights differ substantially from previous estimates. 相似文献
2.
The alpha 5 gene product assembles with multiple acetylcholine receptor subunits to form distinctive receptor subtypes in brain. 总被引:6,自引:0,他引:6
The acetylcholine receptor (AChR) alpha 5 gene has been classified as a member of the AChR gene family based on sequence homology. Expression studies, however, have yet to identify a function for the alpha 5 gene product or even to demonstrate an interaction with known AChR subunits. We report here that the alpha 5 gene product is identical to the 49 kd protein previously found on immunoblots of AChRs purified from brain and ciliary ganglia. In brain the alpha 5 gene product is present both in alpha 3- and in alpha 4-based receptor subtypes, while in the ganglion it is found in an alpha 3-based receptor subtype concentrated in postsynaptic membrane. Immunoprecipitation experiments with subunit-specific monoclonal antibodies indicate that some native AChRs are likely to have at least three kinds of subunits, with two being of the alpha type. These findings support new views about the construction of AChRs in neurons. 相似文献
3.
Molecular cloning of a GTPase activating protein specific for the Krev-1 protein p21rap1 总被引:29,自引:0,他引:29
B Rubinfeld S Munemitsu R Clark L Conroy K Watt W J Crosier F McCormick P Polakis 《Cell》1991,65(6):1033-1042
The rap1/Krev-1 gene encodes a ras-related protein that suppresses transformation by ras oncogenes. We have purified an 88 kd GTPase activating protein (GAP), specific for the rap1/Krev-1 gene product, from bovine brain. Based on partial amino acid sequences obtained from this protein, a 3.3 kb cDNA was isolated from a human brain library. Expression of the cDNA in insect Sf9 cells resulted in high level production of an 85-95 kd rap1GAP that specifically stimulated the GTPase activity of p21rap1. The complete deduced amino acid sequence is not homologous to any known protein sequences, including GAPs specific for p21ras. Northern and Western blotting analysis indicate that rap1GAP is not ubiquitously expressed and appears most abundant in fetal tissues and certain tumor cell lines, particularly the Wilms' kidney tumor, SK-NEP-1, and the melanoma, SK-MEL-3, cell lines. 相似文献
4.
Comparison of α1 -Adrenergic Receptor-Stimulated Inositol Phosphate Formation in Primary Neuronal and Glial Cultures 总被引:3,自引:3,他引:0
alpha 1-Adrenergic receptor binding sites and norepinephrine-stimulated 3H-inositol phosphate (3H-InsP) accumulation were measured in primary cultures of neurons and glia from 1-day-old rat brains. The density of alpha 1-adrenergic receptor binding sites was approximately three times higher in membranes from neurons compared to glia. Although norepinephrine was slightly more potent in stimulating 3H-InsP formation in neurons than in glia, the maximal response was greater in glial cells. Norepinephrine-stimulated 3H-InsP formation remained constant for [3H]inositol prelabelling periods of 1-14 days in neurons, whereas the response increased with time in glia and was maximal after 7-10 days of prelabelling. Both the incorporation of [3H]inositol into lipid and basal levels of 3H-InsPs were lower in glial cells than in neurons, which accounted for the greater percent stimulation in glia. Pretreatment with phenoxybenzamine decreased norepinephrine-stimulated 3H-InsP formation in a dose-dependent manner in both neurons and glia by decreasing the maximal response without altering potency. HPLC separation showed that similar types of 3H-InsPs were accumulated in neurons and glial cells. These results demonstrate that alpha 1-adrenergic receptors exist on both neurons and glial cells and activate 3H-InsP accumulation in both cell types. Although receptor density is higher in neurons than in glia, the 3H-InsP response is higher in glia. This difference does not appear to be due to different receptor reserves, but may be due to differential coupling mechanisms in the two cell types. 相似文献
5.
N J Wosu J A Shadduck S P Pakes J K Frenkel K S Todd J D Conroy 《Laboratory animal science》1977,27(2):210-216
The indirect immunofluorescence antibody test was performed on serial blood samples from eight young New Zealand White rabbits with experimental encephalitozoonosis. The test showed seroconversion in six of the eight infected rabbits by the 8th day after inoculation and in all rabbits by the 15th day. Antibody titers reached a peak by about the 36th day after inoculation and remained significantly elevated until the termination of the experiment at 84 days after inoculation. None of four sham-inoculated rabbits showed an immunofluorescence response by the 60th day after inoculation. Immunofluorescence and intradermal test responses were compared before infection and at the 60th day after inoculation in a total of 32 experimentally infected rabbits. Both tests were equally effective (100%) in detecting infected animals. Six of eight (first group) and 22 of 24 (second group) experimentally infected rabbits were confirmed histologically to have lesions compatible with encephalitozoonosis. No cross reactions were observed between Encephalitozoon cuniculi and Toxoplasma gondii, Eimeria perforans, or Eimeria stiedai by intradermal test or immunofluorescence test. 相似文献
6.
7.
Siobhan Flaherty Pamela Strauch Mahdi Maktabi Brandon S. Pybus Gregory Reichard Larry A Walker Rosemary Rochford 《Journal of cellular and molecular medicine》2022,26(13):3675
Primaquine (PQ) and Tafenoquine (TQ) are clinically important 8‐aminoquinolines (8‐AQ) used for radical cure treatment of P. vivax infection, known to target hepatic hypnozoites. 8‐AQs can trigger haemolytic anaemia in individuals with glucose‐6‐phosphate dehydrogenase deficiency (G6PDd), yet the mechanisms of haemolytic toxicity remain unknown. To address this issue, we used a humanized mouse model known to predict haemolytic toxicity responses in G6PDd human red blood cells (huRBCs). To evaluate the markers of eryptosis, huRBCs were isolated from mice 24–48 h post‐treatment and analysed for effects on phosphatidylserine (PS), intracellular reactive oxygen species (ROS) and autofluorescence. Urinalysis was performed to evaluate the occurrence of intravascular and extravascular haemolysis. Spleen and liver tissue harvested at 24 h and 5–7 days post‐treatment were stained for the presence of CD169+ macrophages, F4/80+ macrophages, Ter119+ mouse RBCs, glycophorin A+ huRBCs and murine reticulocytes (muRetics). G6PDd‐huRBCs from PQ/TQ treated mice showed increased markers for eryptosis as early as 24 h post‐treatment. This coincided with an early rise in levels of muRetics. Urinalysis revealed concurrent intravascular and extravascular haemolysis in response to PQ/TQ. Splenic CD169+ macrophages, present in all groups at day 1 post‐dosing were eliminated by days 5–7 in PQ/TQ treated mice only, while liver F4/80 macrophages and iron deposits increased. Collectively, our data suggest 8‐AQ treated G6PDd‐huRBCs have early physiological responses to treatment, including increased markers for eryptosis indicative of oxidative stress, resulting in extramedullary haematopoiesis and loss of splenic CD169+ macrophages, prompting the liver to act as the primary site of clearance. 相似文献
8.
Endotoxin/lipopolysaccharide activates NF-kappa B and enhances tumor cell adhesion and invasion through a beta 1 integrin-dependent mechanism 总被引:7,自引:0,他引:7
Wang JH Manning BJ Wu QD Blankson S Bouchier-Hayes D Redmond HP 《Journal of immunology (Baltimore, Md. : 1950)》2003,170(2):795-804
Beta(1) integrins play a crucial role in supporting tumor cell attachment to and invasion into the extracellular matrix. Endotoxin/LPS introduced by surgery has been shown to enhance tumor metastasis in a murine model. Here we show the direct effect of LPS on tumor cell adhesion and invasion in extracellular matrix proteins through a beta(1) integrin-dependent pathway. The human colorectal tumor cell lines SW480 and SW620 constitutively expressed high levels of the beta(1) subunit, whereas various low levels of alpha(1), alpha(2), alpha(4), and alpha(6) expression were detected. SW480 and SW620 did not express membrane-bound CD14; however, LPS in the presence of soluble CD14 (sCD14) significantly up-regulated beta(1) integrin expression; enhanced tumor cell attachment to fibronectin, collagen I, and laminin; and strongly promoted tumor cell invasion through the Matrigel. Anti-beta(1) blocking mAbs (4B4 and 6S6) abrogated LPS- plus sCD14-induced tumor cell adhesion and invasion. Furthermore, LPS, when combined with sCD14, resulted in NF-kappaB activation in both SW480 and SW620 cells. Inhibition of the NF-kappaB pathway significantly attenuated LPS-induced up-regulation of beta(1) integrin expression and prevented tumor cell adhesion and invasion. These results provide direct evidence that although SW480 and SW620 cells do not express membrane-bound CD14, LPS in the presence of sCD14 can activate NF-kappaB, up-regulate beta(1) integrin expression, and subsequently promote tumor cell adhesion and invasion. Moreover, LPS-induced tumor cell attachment to and invasion through extracellular matrix proteins is beta(1) subunit-dependent. 相似文献
9.
Anne M. Treasure Siobhan Mackenzie Hall Igor Lesko Derek Moore Malvika Sharan Menno van Zaanen Yo Yehudi Anelda van der Walt 《PLoS computational biology》2022,18(5)
In recent years, a wide variety of mentorship programmes targeting issues that cannot be addressed through traditional teaching and learning methods alone have been developed. Mentoring plays significant roles in the growth and development of both mentors and mentees, and the positive impacts of mentoring have been well documented. Mentorship programmes are therefore increasingly being implemented in a wide variety of fields by organisations, academic institutes, businesses, and governments. While there is a growing body of literature on mentoring and mentorship programmes, gaining a clear overview of the field is often challenging. In this article, we therefore provide a concise summary of recommendations to consider when designing and establishing mentorship programmes. These recommendations are based on the collective knowledge and experiences of 4 different emerging and established mentorship programmes and can be adapted across various mentorship settings or contexts. 相似文献
10.
Jason S. Haukoos Jonathan D. Campbell Amy A. Conroy Emily Hopkins Meggan M. Bucossi Comilla Sasson Alia A. Al-Tayyib Mark W. Thrun For the Denver ED HIV Opt-Out Study Group 《PloS one》2013,8(12)