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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ability of proton NMR relaxation times to detect cardiac allograft rejection was studied in an inbred rat heterotopic cardiac transplantation model. Hearts from 25 Lewis X Brown Norway F1 hybrid rats were anastomosed to the abdominal aorta and vena cava of Lewis recipients; 25 Lewis donor hearts served as isograft controls. Groups of five allografts and five isografts were harvested daily between two and six days post-transplant. The relaxation times T1 and T2 of the transplanted hearts were determined in vitro with a 10 MHz spectrometer. T1 and T2 values in allografts did not differ significantly from those in isografts at days 2 and 3 post-transplant. However, at days 4, 5, and 6 T1 and T2 of the allografts were significantly prolonged. This finding correlated with an elevation in tissue water content and the onset of rejection as determined histologically. An additional 21 allografts, treated with cyclosporine, were studied in the same way from four to more than 100 days post-transplant. T1 and T2 values of these treated allografts did not change significantly during the observation period and were similar to the relaxation values obtained in the isografts at days 2 to 6. These data suggest that serial measurements of myocardial T1 and T2 may be useful in detecting acute cardiac allograft rejection and monitoring the effect of antirejection treatment.
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PMID:The detection of cardiac allograft rejection by alterations in proton NMR relaxation times. 390 83

Pregnancy rate of 310 females and birth weight, dystocia score and percentage of assisted births among 910 calves born from 1972 through 1977 were examined. Dams were 2 to 7 yr old and of Angus x Hereford (AH), Charolais x Hereford (CH), straightbred Hereford (HH) and Brown Swiss x Hereford (SH) breed types. Females were exposed to A and C bulls. Breed of dam affected (P less than .01) dystocia score (DS), percentage of assisted births and birth weight. When adjusted for birth weight of calf and dam's postcalving weight, CH and SH dams generally differed (P less than .01) from AH and HH dams in percentage of assisted births and DS. The AH and HH dams were not different (P greater than .01) in percentage of assisted births, DS or birth weight of calf. C-sired calves had higher birth weights (P less than .01) and their dams had higher DS (P less than .05). However, there was no difference between C- and A-sired calves in percentage of assisted births when data were adjusted for effects of birth weight of calf and weight of dam. Calf sex affected birth weight (P less than .01) but had little influence on DS or percentage of assisted births when birth weight was held constant. Male calves were 1.7 kg heavier at birth than females. Two-year-old dams had higher (P less than .01) DS and percentage of assisted births than did dams in all other age groups. Age of dam influenced birth weight (P less than .01), with paired comparisons of age classes showing differences between all age groups except 4- and greater than or equal to 5-yr-old cows. Year of birth was a source of variation (P less than .05) for all traits measured. In 1972, there was a higher mean DS and a higher percentage of assisted births (P less than .05) than in any other year. However, all calves born in 1972 were from 2-yr-old cows. Percentage difficulty and DS increased linearly (P less than .01) with birth weight. Each 1-kg increment in birth weight increased percentage difficulty by 2.6 percentage points and DS by .04 units. Dam's with heavier weights had calves that were heavier (P less than .01) at birth, but dystocia tended to decrease. Condition entering the breeding pasture influenced (P less than .05) pregnancy rate among 2- to 7-yr-old cows. Thin (score w) cows had a lower conception rate than average flesh (score 3) or fat (score 4) cows. Date of calving prior to the breeding season also affected (P less than .05) pregnancy rate. Each 10 d later calving resulted in a 1.2% reduction in conception rate. No significant sources of variation were observed for pregnancy rate among yearling heifers. Pregnancy rates ranged from 97.1% for CH and SH heifers to 86.9% for HH females. Yearling AH females were intermediate at 93.5%.
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PMID:Beef x beef and dairy x beef females mated to Angus and Charolais sires. I. Pregnancy rate, dystocia and birth weight. 710 32

Immunosuppressive agents used in organ transplantation, including corticosteroids and cyclosporine, may alter the physiology of normal and grafted organs, and may not reverse graft rejection once it is established in the rat model of heterotopic heart transplantation. For the purpose of studying the effects of allograft rejection and its reversal on the molecular basis of contractile dysfunction in cardiac myocytes, we developed a reversible model of cardiac allograft rejection in the rat that does not use immunomodulating agents. In control experiments, 38 Lewis rats underwent heterotopic heart transplantation using Lewis x Brown-Norway F1 (LBNF1) donors. Hearts explanted as early as 4 days after transplantation demonstrated lymphocytic infiltrates and evidence of myocyte necrosis. In the present experiments, five LBNF1 cardiac grafts were transplanted into Lewis rats. After 4 days, the hearts were explanted and reimplanted into syngeneic LBNF1 rats. Hearts were removed for histologic examination after 2 days. Four of the five hearts showed complete resolution of the lymphocytic infiltrate. One heart had a sparse residual infiltrate. Five control isografts (Lewis/Lewis) were also explanted and reimplanted into Lewis rats. Histologic examination after 2 days showed normal morphology. Reversal of allograft rejection by retransplantation is possible in the rat model without the use of immunosuppression, permitting the investigator to study intracellular processes that otherwise might be influenced by immune suppression.
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PMID:Reversal of cardiac allograft rejection without immunotherapy: an animal model. 817 32

There is a need to develop new and more consistent animal models of cardioprotection. Traditionally, outbred dogs, rabbits, and rats have been studied. We determined resistance to ischemia in isolated hearts from inbred strains of rats. Hearts from inbred rats: SS/Mcw (Dahl S, Dahl salt-sensitive), DA/Hsd (Dark Agouti), LEW/Hsd (Lewis), and BN/SsN/Mcw (Brown Norway); and from an outbred rat: Hsd:WIST (Wistar) were subjected to 27 min of global, no-flow ischemia, followed by 3 h of reperfusion. Infarct size in the Brown Norway rat was 2.5 times less than that observed in the Dahl S rat, with the Dark Agouti, Lewis, and Wistar rats intermediate in response. Hearts from Brown Norway rats were also most resistant to ischemia in terms of postischemic enzyme leakage and contractile and vascular function compared with other strains. The average polymorphism rate between strains revealed that such strains were genetically diverse. This study demonstrates strain differences in resistance to myocardial ischemia, suggesting these rats could be used to study a genetic and/or environmental basis for these differences and to provide new animal models for the physiological study of cardioprotection.
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PMID:Resistance to myocardial ischemia in five rat strains: is there a genetic component of cardioprotection? 1074 37

Hearts from Brown Norway (BN/Mcw) rats are more resistant to ischemia than hearts from Dahl S (SS/Mcw) rats. We determined whether nitric oxide (.NO) is responsible for increased cardioprotection in BN/Mcw vs. SS/Mcw hearts. Hearts from the two strains were treated with N(G)-monomethyl-L-arginine (L-NMA) or S-nitrosoglutathione (GSNO) before ischemia and reperfusion. Infarct size in untreated BN/Mcw hearts was approximately 63% less than in SS/Mcw hearts. Inhibiting NOS with L-NMA increased infarct size in BN/Mcw hearts to that observed in untreated SS/Mcw hearts but did not further increase injury in SS/Mcw hearts. The .NO donor GSNO decreased infarct size in SS/Mcw rats but had no effect on BN/Mcw hearts. Plasma and heart tissue from BN/Mcw rats contained 80% and 130% more nitrite + nitrate than that from SS/Mcw rats. These data suggest that increased .NO production protects BN/Mcw hearts from ischemic injury. Real time PCR showed no differences in NOS1, NOS2 or NOS3 isozyme transcripts in the hearts from the two strains. NOS3 was the only isozyme detected by western analysis. Both strains exhibited the same level of NOS3 and hsp90 protein expression. However, hsp90 association with NOS3 in BN/Mcw hearts was increased twofold compared with SS/Mcw hearts. Inhibiting hsp90-NOS3 interaction with geldanamycin decreased the resistance to ischemia in BN/Mcw hearts but not in SS/Mcw hearts. SS/Mcw hearts also generated three times more N(omega)-nitro-L-arginine-methylester inhibitable superoxide than BN/Mcw hearts. These findings indicate that hsp90 with NOS3 increases .NO production and decreases uncoupled NOS3 activity. We conclude increased association of hsp90 with NOS3 is a major mechanism by which BN/Mcw hearts are more resistant to ischemia than SS/Mcw hearts.
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PMID:Increased resistance to myocardial ischemia in the Brown Norway vs. Dahl S rat: role of nitric oxide synthase and Hsp90. 1580 39

Aging is associated with left ventricular hypertrophy, dilatation, and fibrosis of the heart. The Fischer 344/Brown Norway F1 (F344/BNF1) rat is recommended for age-related studies by the National Institutes on Aging because this hybrid rat lives longer and has a lower rate of pathological conditions than inbred rats. However, little is known about age-associated changes in cardiac and aortic function and structure in this model. This study evaluated age-related cardiac changes in male F344/BNF1 rats using ECHO, gross, and microscopic examinations. Rats aged 6-, 30-, and 36-mo were anesthetized and two-dimensional ECHO measurements, two-dimensional guided M-mode, Doppler M-mode, and other recordings from parasternal long- and short-axis views were obtained using a Phillips 5500 ECHO system with a 12 megahertz transducer. Hearts and aortas from sacrificed rats were evaluated grossly and microscopically. The ECHO studies revealed persistent cardiac arrhythmias (chiefly PVCs) in 72% (13/18) of 36-mo rats, 10% (1/10) of 30-mo rats, and none in 6-mo rats (0/16). Gross and microscopic studies showed left ventricular (LV) dilatation, borderline to mild hypertrophy, and areas of fibrosis that were common in 36-mo rats, less evident in 30-mo rats, and absent in 6-mo rats. Aging was associated with mild to moderate decreases of LV diastolic and systolic function. Thus, male F344/BN F1 rats demonstrated progressive age-related (a) decline in cardiac function (diastolic and systolic indices), (b) LV structural changes (chamber dimensions, volumes, and wall thicknesses), and (c) persistent arrhythmias. These changes are consistent with those in humans. The noninvasive ECHO technique offers a means to monitor serial age-related cardiac failure and therapeutic responses in the same rats over designated time intervals.
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PMID:Age-associated changes in hearts of male Fischer 344/Brown Norway F1 rats. 1712 29

Mitomycin C (MMC) is an alkylating agent which suppresses allogeneic T-cell responses. We analyzed the effect of graft perfusion with MMC on transplant survival. Hearts from Brown-Norway (BN) rats were perfused ex vivo with MMC-containing solution, stored and implanted into Lewis (LEW) rats. In order to analyze the in vivo effect of MMC, recipients received MMC posttransplantation or were pretreated with MMC-incubated donor-derived peripheral blood mononuclear cells (PBMCs). The results show that MMC-perfusion significantly prolongs graft survival. Treatment of recipients with MMC has no effect, whereas MMC-treated donor PBMCs injected into the recipient prolong graft survival. Our findings indicate that the targeted perfusion of donor hearts with MMC-containing solution protects the graft from rejection.
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PMID:Ex vivo perfusion with mitomycin C containing solution prolongs heart graft survival in rats. 1716 9

Prevention of graft dysfunction is a major objective in transplantation medicine. Previous research on experimental heart transplantation indicated that treatment with the immunomodulatory peptide alpha-melanocyte stimulating hormone (alpha-MSH) improves histopathology, prolongs allograft survival, and reduces expression of the main tissue injury mediators. Because calcium-handling is critical in heart graft function, we determined the effects of transplantation injury and influences of alpha-MSH treatment on representative calcium regulatory proteins in rat heart allografts. Hearts from Brown Norway rats were transplanted heterotopically into MHC incompatible Lewis rats. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), protein kinase C epsilon (PKC epsilon), sarcoplasmic/endoplasmic reticulum calcium-ATPase 2 (SERCA2a), arrestin-beta1 (Arrb1), cholinergic receptor M2 (Chrm2), and inositol 1,4,5-triphosphate receptor 1 (InsP(3)R1) were examined in: (1) non-transplanted donor hearts; (2) allografts from saline-treated rats; and (3) allografts from rats treated with the synthetic alpha-MSH analog Nle4-DPhe7-alpha-MSH (NDP-alpha-MSH) (100 microg i.p. every 12h). Transplantation injury was associated with severe reduction in calcium regulatory protein transcription and expression level. NDP-alpha-MSH administration partly reversed inhibition of protein transcription and almost completely prevented protein loss. Finally, because certain effects of cyclic 3'-5'-adenosine monophosphate (cAMP) signaling on calcium handling in cardiac myocytes depend on activation of exchange protein directly activated by cAMP 1 (Epac1), we determined Epac1 mRNA and protein expression in heart allografts. Transplantation injury markedly reduced Epac1. NDP-alpha-MSH treatment significantly preserved both Epac1 protein and mRNA in the allografts. Administration of alpha-MSH or related melanocortins could reduce transplantation-induced dysfunction through protection of heart calcium regulatory proteins.
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PMID:Treatment with alpha-melanocyte stimulating hormone preserves calcium regulatory proteins in rat heart allografts. 1817 58

The present study evaluated the effect of a brief mindfulness-based preventive intervention on (a) dispositional (MAAS; Brown & Ryan, 2003) and state (SMS; Tanay & Bernstein, 2010) mindfulness; (b) putative proximal factors/processes engendered through the development of mindfulness, including increased decentering (EQ-D; Fresco et al., 2007) and reduced experiential avoidance (AAQ; Hayes et al., 2004); and (c) distal mood and anxiety vulnerability factors, including reduced depression-related dysfunctional attitudes, (DAS; de Graaf, Roelofs, & Huibers, 2009), anxiety sensitivity (ASI-3; Taylor et al., 2007), and negative affectivity (PANAS-NA; Watson, Clark, & Tellegen, 1988) among a university-community sample in Israel. Fifty-three adult participants between the ages of 20 and 52 (M(age)=25.2 years, SD(age)=4.3 years; 65.4% women) were recruited from the Haifa University community. Nineteen participants were randomly assigned to an experimental condition (M(age)=25.3 years, SD(age)=4.3 years; 66% women) and studied prospectively over the course of a four-session (21-day) mindfulness skills training intervention; and 34 participants were randomly assigned to a no-intervention (control) condition (M(age)=24.9 years, SD(age)=2.4years; 64.7% women) and studied prospectively. Findings demonstrate statistically robust and clinically significant relations between mindfulness and the theorized proximal and distal mood and anxiety vulnerability factors. Findings are discussed with respect to their theoretical implications for better understanding mindfulness-psychopathology vulnerability relations, clinical implications for larger-scale universal and selective transdiagnostic prevention efforts, and future directions for this area of research.
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PMID:Salutary proximal processes and distal mood and anxiety vulnerability outcomes of mindfulness training: a pilot preventive intervention. 2269 39

The purpose of this two-study project was to determine the effects of cognitive bibliotherapy for the treatment of depressive symptoms in jail and prison inmates. Participants in both samples were randomly assigned to either a treatment group that received the 4-week bibliotherapy program or a delayed-treatment control group. In the jail sample, which served as a pilot study for the more detailed prison study, the treatment group showed greater improvement on the A. T. Beck and R. A. Steer Beck Depression Inventory, 1993, Psychological Corporation, San Antonio, TX and the DAS (M. M. Weissman, & A. T. Beck Development and validation of the Dysfunctional Attitudes Scale: A preliminary investigation; paper presented at the meeting of the American Educational Research Association, November, 1978, Toronto, ON, Canada). In the prison sample, results indicated that the treatment group showed greater improvement on the HRSD (M. Hamilton, Development of a rating scale for primary depressive illness, British Journal of Social & Clinical Psychology, Vol. 6, 1967, pp. 278-296) and the A. T. Beck, R. A. Steer, & G. K. Brown Beck Depression Inventory (2nd ed.), 1996, Psychological Corporation, San Antonio, TX. Approximately half of the treated participants achieved clinically significant change. Analyses of the follow-up data revealed maintenance of treatment gains in the prison and jail samples. In the prison study, significant changes were also observed on a general measure of psychological distress. Overall, results suggest that cognitive bibliotherapy may be efficacious for depressed inmates.
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PMID:Efficacy and process of cognitive bibliotherapy for the treatment of depression in jail and prison inmates. 2383 67


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