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C57BL/6 Strain (c57bl/6 + strain)
Selected AbstractsEchocardiographic Evaluation of Ventricular Function in MiceECHOCARDIOGRAPHY, Issue 1 2007Jeffrey N. Rottman M.D. Ventricular dysfunction remains a hallmark of most cardiac disease. The mouse has become an essential model system for cardiovascular biology, and echocardiography an established tool in the study of normal and genetically altered mice. This review describes the measurement of ventricular function, most often left ventricular function, by echocardiographic methods in mice. Technical limitations related to the small size and rapid heart rate in the mouse initially argued for the performance of echocardiography under anesthesia. More recently, higher frame rates and smaller probes operating at higher frequencies have facilitated imaging of conscious mice in some, but not all, experimental protocols and conditions. Ventricular function may be qualitatively and quantitatively evaluated under both conditions. Particular detail is provided for measurement under conscious conditions, and measurement under conscious and sedated or anesthestized conditions are contrasted. Normal values for echocardiographic indices for the common C57BL/6 strain are provided. Diastolic dysfunction is a critical pathophysiologic component of many disease states, and progress in the echocardiographic evaluation of diastolic function is discussed. Finally, echocardiography exists among several competing imaging technologies, and these alternatives are compared. [source] C1473G polymorphism in mouse tph2 gene is linked to tryptophan hydroxylase-2 activity in the brain, intermale aggression, and depressive-like behavior in the forced swim testJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2009Daria V. Osipova Abstract Tryptophan hydroxylase-2 (TPH2) is the rate-limiting enzyme of brain serotonin synthesis. The C1473G polymorphism in the mouse tryptophan hydroxylase-2 gene affects the enzyme's activity. In the present study, we investigated the linkage between the C1473G polymorphism, enzyme activity in the brain, and behavior in the forced swim, intermale aggression, and open field tests using mice of the C57BL/6 (C/C) and CC57BR/Mv (G/G) strains and the B6-1473C (C/C) and B6-1473G (G/G) lines created by three successive backcrossings on C57BL/6. Mice of the CC57BR/Mv strain had decreased brain enzyme activity, aggression intensity, and immobility in the forced swim test, but increased locomotor activity and time spent in the central part of the open field arena compared with animals of the C57BL/6 strain. Mice of the B6-1473G line homozygous for the 1473G allele had lower TPH2 activity in the brain, aggression intensity, and immobility time in the forced swim test compared with animals of the B6-1473C line homozygous for the 1473C allele. No differences were found between the B6-1473G and B6-1473C mice in locomotor activity and time spent in the central part of the arena in the open field test. Thus, the C1473G polymorphism is involved in the determination of TPH2 activity and is linked to aggression intensity and forced-swim immobility in mice. At the same time, the polymorphism does not affect locomotion and anxiety-related behavior in the open field test. The B6-1473C and B6-1473G mice represent a valuable experimental model for investigating molecular mechanisms of serotonin-related behavior. © 2008 Wiley-Liss, Inc. [source] Isolates of Trichuris muris elicit different adaptive immune responses in their murine hostPARASITE IMMUNOLOGY, Issue 3 2005C. E. Johnston SUMMARY The J and S isolates of Trichuris muris have different infection profiles in C57BL/6 mice; J worms are expelled, S worms survive to chronicity. Building on this, the ability of the J and S isolates to survive, and the quality of the immune response induced was explored in three different strains of mouse. The resistant BALB/c mouse mounted a strong Th2 response against both isolates, which were quickly expelled. The susceptible AKR host mounted a Th1 response and retained both isolates. Despite equivalent worm exposure, mesenteric lymph node cells from AKR mice infected with the S isolate produced significantly higher levels of IL-12 and the intestinal mastocytosis was reduced. IgG1 and IgG2a from S-infected AKR mice recognized low molecular weight antigens not recognized by J-infected mice. Differential expulsion kinetics was observed in the slower-responding C57BL/6 strain; J worms were expelled but S isolate worms were retained. Survival of the S isolate was again associated with elevated IL-12 and decreased Th2 responses. In resistant mouse strains, the outcome of infection is thus dominantly influenced by host genetics. However, in the slower-responding host, isolate-derived factors may play a role in shaping the quality of the adaptive immune response, thus influencing parasite survival. [source] The cuprizone model for demyelinationACTA NEUROLOGICA SCANDINAVICA, Issue 2008Ø. Torkildsen Background ,, Important advances in multiple sclerosis (MS) research have been made as a direct or indirect result of experiments in animal models for the disease, although MS is a disease only affecting humans. The cuprizone model is a model for toxic demyelination. In this model, young mice are fed with the copper chelator cuprizone, leading to oligodendrocyte death and a subsequent reversible demyelination. Spontaneous remyelination can be seen as early as 4 days after withdrawal of cuprizone. Materials and methods ,, This article reviews previous research on this model and discusses the potential of the model for future application in MS research. Discussion ,, The cuprizone model correlates with newer histopathological data in MS and is a valuable tool for studies on de- and remyelination. The use of the C57BL/6 strain offers the potential for future studies on transgene and knockout mice. [source] Insulin-independent promotion of chemically induced hepatocellular tumor development in genetically diabetic miceCANCER SCIENCE, Issue 1 2010Kohtaro Yamasaki Diabetes mellitus has been proposed as an epidemiological risk factor for human liver cancer development. One reasonable possibility is that this is attributable to hyperinsulinemia compensatory for obesity-related insulin resistance. However, diabetes mellitus is a complex disease with multiple abnormal conditions essentially caused by hyperglycemia. Therefore, it is not evident whether hyperinsulinemia is prerequisite for the elevated cancer risk. To gain a clue to answer this question, we characterized chemically induced hepatocarcinogenesis in diabetic model mice genetically deficient for insulin. Akita inbred mice originating from the C57BL/6 strain carry a heterozygous germline mutation of the insulin II gene and suffer from inherited insulin deficiency and diabetes in an autosomal dominant manner. They were mated with normal C3H/HeJ mice with high sensitivity to liver carcinogenesis and the resultant F1 littermates, which were either normal or insulin deficient, were exposed to diethylnitrosamine and induced hepatocellular tumors were evaluated for number, size, proliferative activity, and apoptosis. Unexpectedly, both mean and total volumes of hepatocellular tumors in the insulin-deficient animals were more than twofold larger than those in the normal controls, with no significant difference in tumor number. The tumors in insulin-deficient mice showed a significantly lower frequency of apoptosis but no alteration in cell proliferation. In conclusion, our results indicate that insulin-independent liver tumor promotion occurred in diabetic mice. Clearly, insulin-independent mechanisms for the human case also deserve consideration. (Cancer Sci 2009) [source] Subchronic exposure of BALB/c and C57BL/6 strains of Mus musculus to the radioactive environment of the Chornobyl, Ukraine exclusion zoneENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Brenda E. Rodgers Abstract Environmental contamination resulting from the Chornobyl, Ukraine, disaster offers a unique opportunity to examine the in vivo biological effects of chronic, low-dose exposure to radiation. Laboratory studies of acute exposure to ionizing radiation have been used to estimate risk and potential human health effects by the extrapolation of laboratory data to situations of low-dose environmental radiation exposure. Few studies, however, have explored the biological consequences of low-dose exposure via in situ environmental radiation in a sentinel species. In the present study, laboratory strains of Mus musculus (BALB/c and 57BL/ 6) were placed in environmental enclosures in the Red Forest region of the Chornobyl exclusion zone. Blood samples were obtained every 10 d, and the micronucleus (MN) test was employed to assess the potential for cytogenetic damage from exposure to Chornobyl radiation. Radionuclide uptake was monitored throughout the study, and dose was estimated for each individual as well as for their offspring. Total dose for the mice experimentally exposed to this environment averaged 1162 mGy for BALB/c (30 d) and 1629 mGy for C57BL/6 (40 d). A higher MN frequency for both strains was observed at day 10, although this change was only statistically significant in the C57BL/6 mice (,23 = 13.41, p = 0.003). Subsequent samples from C57BL/6 resulted in values at or less than the initial frequencies. In BALB/c mice, an increase in MN was also evident at day 30 (,22 = 10.38, p = 0.006). The experimental design employed here allows for the incorporation of traditional laboratory strains, as well as transgenic strains of Mus, as sentinels of environmental radiation contamination. [source] Strain differences in ,1 receptor-mediated behaviours are related to neurosteroid levelsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2002Vân-Ly Phan Abstract The sigma1 (,1) receptor exerts a potent neuromodulatory role in the brain with relevant consequences in memory processes, response to stress, depression and pharmacodependence. Its precise endogenous ligand is not yet identified but the ,1 receptor appears to be one target for the nongenomic rapid effects of neuroactive steroids in the brain. The aim of the present study was to establish whether differences in ,1 receptor-mediated behaviours could be observed among mouse strains, in relation with differences in either ,1 receptor expression or steroid levels. The ,1 -receptor immunohistochemical distribution appeared similar between Swiss and C57BL/6 strains in all the brain structures examined. The levels of in vivo[3H](+)-SKF-10 047 binding to ,1 receptors were lower in Swiss than in C57BL/6. Adrenalectomy/castration significantly increased [3H](+)-SKF-10 047 binding only in Swiss. The behavioural efficacy of the selective ,1 agonists igmesine and PRE-084 , reversion of the scopolamine-induced amnesia in the passive avoidance test; diminution of the immobility duration in the forced swimming test , were significantly higher in C57BL/6 than in Swiss. Steroid levels were measured in the brain in basal conditions and after stress. C57BL/6 mice presented in both conditions, the lowest progesterone levels, this steroid acting as an endogenous ,1 antagonist. Collectively, the results suggested that strain differences in neuroactive steroid and particularly, progesterone, biosynthesis and sensitivity may contribute to the differential behavioural efficacy of ,1 -receptor ligands. Noteworthy, these observations are coherent with strain differences observed in the intensity of cocaine-induced reward properties, known to critically involve the ,1 receptor. [source] Strain differences in autotomy in mice after peripheral nerve transection or repairMICROSURGERY, Issue 4 2003Roee E. Rubinstein A.B. The purpose of this study was to identify the optimal murine model for the study of peripheral nerve injury and nerve and limb transplantation. The degree of self-mutilation (autotomy) following sciatic and saphenous nerve injury was assessed in four mouse strains, Balb/C, C57BL/6J, C57BL/10J, and C3HEB, commonly used in surgical research. Experimental groups included sciatic and saphenous nerve transection with repair (n = 9) or without repair (n = 9), as well as housing arrangements favoring social interaction vs. isolation. Autotomy was most prevalent in the Balb/c and C3H strains at 56% and 89% overall, respectively, and was much less frequently seen in the C57Bl/10 and C57Bl/6 strains (22% and 11%, respectively). Autotomy was found to correlate most strongly with mouse strain, and with social contact as well. Two strains, C57BL/6J and C57BL/10J, were found to be highly resistant to self-mutilation, and are thus ideal animal models for peripheral-nerve and whole-limb transplant studies. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:363,368 2003 [source] | |||||||||||||