Accumulation of gold nano-rods in the failing heart of transgenic mice with the cardiac-specific expression of TNF-α.

Gold nano-rods, rod-shaped gold nanoparticles, act as contrast agents for in vivo bioimaging, drug delivery vehicles and thermal converters for photothermal therapy. Pro-inflammatory cytokines play critical roles in the development of heart failure. We examined the delivery of GNRs into the failing heart of a transgenic (TG) mouse model of inflammatory cardiomyopathy with the cardiac-specific overexpression of TNF-α. We modified GNRs with polyethylene glycol (PEG) to avoid cytotoxicity and reduce the rapid clearance of nanoparticles from blood. PEG-modified GNRs (4.5 mM as gold atoms, 200 µL) were administered intravenously to TG (n = 7) and wild-type (WT) mice (n = 5). These were killed 24 h later, and the heart, lung, liver, kidney and spleen were excised. A quantitative analysis of gold was performed using inductively coupled plasma mass or optical emission spectrometry. The amount of gold (ng) in the TG heart (3.24 ± 1.56 ng/mg heart weight) was significantly greater than that in the WT heart (1.01 ± 0.19; p < 0.05). No significant differences were observed among the other organs of TG and WT mice. The amount of gold in the TG heart was significantly and positively correlated with the ratio of the ventricular weight to body weight, which is known to be an index of ventricular hypertrophy. In conclusion, PEG-modified GNRs accumulated in the inflammatory TG heart in proportion with the severity of ventricular hypertrophy.

Calorie restriction increases telomerase activity, enhances autophagy, and improves diastolic dysfunction in diabetic rat hearts.

The aims of this study were to investigate the impact of caloric restriction (CR) on cardiac telomere biology in an animal model of diabetes and to examine the signal transduction involved in cell senescence as well as cardiac function. Male 8-week-old Otsuka Long-Evans Tokushima fatty (OLETF) diabetic rats were divided into two groups: a group fed ad libitum (OLETF-AL) and a group fed with CR (OLETF-CR: 30% energy reduction). Long-Evans Tokushima Otsuka (LETO) non-diabetic rats were used as controls. LETO rats were also divided into two groups: a CR (LETO-CR) group and a group fed AL (LETO-AL). At 40 weeks of age, the body weight was decreased by 9.7% and the insulin resistance was less in OLETF-CR rats. Telomerase activity in OLETF-CR rats was significantly increased, and telomerase reverse transcriptase was more highly expressed in those rats. However, the telomere length (TL) was not different between AL- and CR-treated rats of each strain. The protein expressions for FoxO1 and FoxO3 were increased in OLETF-AL rats, but the levels of phosphorylated (p)-Akt were decreased compared to those in OLETF-CR rats. Autophagic LC3II signals revealed significant increases in OLETF-CR rats. Echocardiography showed that OLETF-CR improved the left ventricular diastolic dysfunction without changes in the left ventricular dimension. This study revealed that CR increases cardiac telomerase activity without TL attrition, and significantly ameliorates diastolic dysfunction. These findings suggest that cardiac telomerase activity may play an important role in the maintenance of normal cardiac function.

Butea superba-induced amelioration of cognitive and emotional deficits in olfactory bulbectomized mice and putative mechanisms underlying its actions.

This study investigated the effects of alcoholic extract of Butea superba (BS) on cognitive deficits and depression-related behavior using olfactory bulbectomized (OBX) mice and the underlying molecular mechanisms of its actions. OBX mice were treated daily with BS (100 and 300 mg/kg, p.o.) or reference drugs, tacrine (2.5 mg/kg, i.p.) and imipramine (10 mg/kg, i.p.) from day 3 after OBX. OBX impaired non-spatial and spatial cognitive performances, which were elucidated by the novel object recognition test and modified Y maze test, respectively. These deficits were attenuated by tacrine and BS but not imipramine. OBX animals exhibited depression-like behavior in the tail suspension test in a manner reversible by imipramine and BS but not tacrine. OBX down-regulated phosphorylation of synaptic plasticity-related signaling proteins: NMDA receptor, AMPA receptor, calmodulin-dependent kinase II, and cyclic AMP-responsive element-binding protein. OBX also reduced choline acetyltransferase in the hippocampus. BS and tacrine reversed these neurochemical alterations. Moreover, BS inhibited ex vivo activity of acetylcholinesterase in the brain. These results indicate that BS ameliorates not only cognition dysfunction via normalizing synaptic plasticity-related signaling and facilitating central cholinergic systems but also depression-like behavior via a mechanism differing from that implicated in BS amelioration of cognitive function in OBX animals.

Repetitive hyperthermia attenuates progression of left ventricular hypertrophy and increases telomerase activity in hypertensive rats.

We investigated the hypothesis that repetitive hyperthermia (RHT) attenuates the progression of cardiac hypertrophy and delays the transition from hypertensive cardiomyopathy to heart failure in Dahl salt-sensitive (DS) hypertensive rats. Six-week-old DS rats were divided into the following five groups: a normal-salt diet (0.4% NaCl) (NS group), a normal-salt diet plus RHT by daily immersion for 10 min in 40°C water (NS+RHT group), a high-salt diet (8% NaCl) (HS group), a high-salt diet (8% NaCl) plus RHT (HS+RHT group), and high-salt diet (8% NaCl) plus RHT with 17-DMAG (HSP90 inhibitor) administration (HS+RHT+17-DMAG group). All rats were killed at 10 wk. Cardiac hypertrophy and fibrosis were noted in the HS group, whereas RHT attenuated salt-induced cardiac hypertrophy, myocardial and perivascular fibrosis, and blood pressure elevation. The phosphorylated endothelial nitric oxide synthase (eNOS) and Akt were decreased in the HS group compared with the NS group, but these changes were not observed in the HS+RHT group. The levels of HSP60, 70, and 90 were elevated by RHT. Moreover, the increased levels of iNOS, nitrotyrosine, Toll-like receptor-4, BNP, PTX3, and TBARS in the HS group were inhibited by RHT. Telomeric DNA length, telomerase activity, and telomere reverse transcriptase (TERT) were reduced in the HS group; however, these changes were partially prevented by hyperthermia. In conclusion, RHT attenuates the development of cardiac hypertrophy and fibrosis and preserves telomerase, TERT activity and the length of telomere DNA in salt-induced hypertensive rats through activation of eNOS and induction of HSPs.

Upregulation of anticoagulant proteins, protein S and tissue factor pathway inhibitor, in the mouse myocardium with cardio-specific TNF-α overexpression.

Heart failure (HF) has been recognized as a hypercoagulable state. However, the natural anticoagulation systems in the failing heart have not been studied. Recent experimental and clinical data have indicated that not only the thrombomodulin (TM)/protein C (PC) pathway but also the protein S (PS)/tissue factor pathway inhibitor (TFPI) system function as potent natural anticoagulants. To investigate the balance between procoagulant and anticoagulant activities in the failing heart, we measured the cardiac expression of tissue factor (TF), type 1 plasminogen activator inhibitor (PAI-1), TM, PC, PS, and TFPI by RT-PCR and/or Western blot analysis in male transgenic (TG) mice with heart-specific overexpression of TNF-α. Both procoagulant (TF and PAI-1) and anticoagulant (PS and TFPI) factors were upregulated in the myocardium of 24-wk-old TG (end-stage HF) but not in that of 4-wk-old TG (early decompensated HF) compared with the wild-type mice. Both factors were also upregulated in the infarcted myocardium at 3 days after coronary ligation in the wild-type mice. The expression of TM was downregulated in the TG heart, and PC was not detected in the hearts. The transcript levels of PS orphan receptors, Mer and Tyro3, but not Axl, were significantly upregulated in the TG heart. Double immunohistochemical staining revealed that myocardial infiltrating CD3-positive T cells may produce PS in the TG myocardium. In conclusion, the PS/TFPI was upregulated in the myocardium of a different etiological model of HF, thus suggesting a role for the PS/TFPI system in the protection of the failing heart under both inflammatory and hypercoagulable states.

Aging-associated alteration of telomere length and subtelomeric status in female patients with Parkinson's disease.

A telomere is a repetitive DNA structure at chromosomal ends that stabilizes the chromosome structure and prevents harmful end-to-end recombinations. The telomere length of somatic cells becomes shorter with aging because of the "end replication problem." This telomere shortening is accelerated by pathophysiological conditions including daily mental stress. Living with Parkinson's disease (PD) causes physical and mental stress; therefore, the authors hypothesized that the telomere length of somatic cells was shortened excessively in patients with PD. In order to detect PD-associated somatic telomeric alterations, the telomere length and subtelomeric methylation status of peripheral leukocytes of PD patients were assessed by Southern blotting, using methylation-sensitive and -insensitive isoschizomers. The results demonstrated that the peripheral leukocytes of Japanese female patients with PD bore fewer long telomeres and a proportional increase of hypomethylated subtelomeres in short telomeres in comparison with the healthy controls. This study indicates that with the neurodegeneration associated with PD, telomeric and subtelomeric structural alterations occur. These structural telomere alterations most likely occur secondary to the acceleration of aging-associated telomeric changes and the accelerated loss of cells bearing short telomeres.

Antioxidant therapy attenuates myocardial telomerase activity reduction in superoxide dismutase-deficient mice.

Oxidative stress plays a pathological role in the development of heart failure. This study examined telomere biology in heart/muscle-specific manganese superoxide dismutase-deficient mice (H/M-SOD2(-/-)), which develop progressive congestive heart failure and exhibit pathology typical of dilated cardiomyopathy. EUK-8 (25mg/kg/day), a superoxide dismutase and catalase mimetic, was administered to H/M-SOD2(-/-) mice for four weeks beginning at 8 weeks of age. Telomere length, telomerase activity, telomere-associated proteins, and cell death signals were assessed in hearts from control wild-type mice (H/M-Sod2 (lox/ lox)) and H/M-SOD2(-/-) mice either treated or untreated with EUK-8. While cardiac function was unchanged in these experimental mice, the end-diastolic dimension in H/M-SOD2(-/-) mice was notably dilated and could be significantly reduced by EUK-8 treatment. At the end of the study, no shortening of telomere length was observed in heart tissues from all mice tested, but telomerase activity was decreased in heart tissue from H/M-SOD2(-/-) mice compared to control mice. Protein expression for telomerase reverse transcriptase and telomere repeat binding factor 2 was also downregulated in H/M-SOD2(-/-) heart tissue as was expression of phospho-Akt, insulin-like growth factor, and endothelial nitric oxide synthase. Expression levels of Sirt1, a lifespan modulator, were enhanced while FoxO3a was depressed in H/M-SOD2(-/-) hearts. All of the changes seen in H/M-SOD2(-/-) heart tissue could be inhibited by EUK-8 treatment. Taken together, the results suggest that oxidant stress might affect myocardial telomerase activity and telomere-associated proteins. Telomerase may therefore play a pivotal role in antioxidant defense mechanisms, and may be useful as a novel therapeutic tool for treating human heart failure.

The correlation between clinical laboratory data and telomeric status of male patients with metabolic disorders and no clinical history of vascular events.

The telomere length and subtelomeric methylated status of peripheral blood leukocytes has been reported to be correlated with many kinds of pathophysiological conditions. However, the correlation between the telomeric parameters and clinical laboratory data in metabolic disorders is not well known. This study investigated the correlation between the telomere length and subtelomeric methylated status in peripheral leukocytes and the laboratory data of male outpatients with combined metabolic disorders and no clinical history of cardiovascular or cerebrovascular event were assessed, to find good clinical laboratory markers reflecting the biological aging. The laboratory data were collected in 26 Japanese male outpatients with diabetes mellitus and hyperlipidemia, and no history of cardiovascular or cerebrovascular event, and the telomeric parameters in their peripheral leukocytes were determined by Southern blot with methylation-sensitive and insensitive isoschizomers. Any correlations between the laboratory data and the telomeric parameters were assessed. The patients showed a significant negative correlation among the bilirubin and creatine phosphokinase with the aging-associate change of the telomeric and subtelomeric parameters. Lowered serum bilirubin and creatinine phosphokinase level correlated to genomic aging represented by telomere attrition of patients with metabolic disorders.

The physical ability of Japanese female elderly with cerebrovascular disease correlates with the telomere length and subtelomeric methylation status in their peripheral blood leukocytes.

BACKGROUND: The telomere length and subtelomeric methylated status of peripheral blood leukocytes have been reported to be correlated with many kinds of pathophysiological conditions. However, the correlation between the telomeric parameters and patients' physical ability is not known. OBJECTIVE: This study aims to study how telomeric parameters, including telomere length and the subtelomeric methylation status of peripheral blood leukocytes, are associated with the physical inability of patients with cerebrovascular disease and its improvement by inpatient rehabilitation. METHODS: The physical ability of female patients with cerebrovascular disease admitted in the chronic disease ward of Kyushu University Hospital was assessed using the Barthel index, and the telomeric parameters in their peripheral blood leukocytes were determined by Southern blotting with methylation-sensitive and -insensitive isoschizomers. RESULTS: The patients revealed a significant correlation between Barthel score and the mean telomere length and expression of long telomeres (> 9.4 kb). Improvement of the Barthel index of patients during admission was correlated not to telomere length, but to subtelomeric hypermethylation of long telomeres. CONCLUSIONS: The physical ability of patients was positively correlated with the lengths of their somatic telomeres, and the recovery potential of physical ability was associated with the subtelomeric hypermethylated status stabilizing long telomeric structure.

Green tea catechins improve human forearm endothelial dysfunction and have antiatherosclerotic effects in smokers.

BACKGROUND: Because green tea reduces cardiovascular and cerebrovascular risk, the purpose of this study aimed to elucidate the effect of green tea catechins (GTC) on endothelial dysfunction in smokers. METHODS AND RESULTS: The 30 healthy male smokers were divided into 3 groups and given green tea beverages containing 0 mg (control group), 80 mg (medium-dose group) or 580 mg (high-dose group) of GTC daily for 2 weeks. Endothelial-dependent and- independent vasodilatation was investigated by measuring the forearm blood flow (FBF) responses to acetylcholine and sodium nitroprusside using venous occlusion strain-gauge plethysmography. The FBF response to acetylcholine significantly increased at 2 h and 1 and 2 weeks after GTC intake in the high-dose group, but no increase was observed in the other groups. FBF responses to sodium nitroprusside did not alter in any group at any time point. A significant increase in plasma nitric oxide and a decrease in asymmetrical dimethylarginine, malondealdehyde and 4-hydroxynonenal, C-reactive protein, monocyte chemotactic protein-1, and soluble CD40 ligand levels were detected after chronic consumption of high-dose GTC. CONCLUSIONS: GTC have antiatherosclerotic effects on dysfunctional vessels in smokers through increasing the level of nitric oxide and reducing oxidative stress.

[Role of the environmental factors on aging].

Aging is a process of irreversible decline in physiological function over the time. Several postulated mechanisms for aging include cumulative DNA damage, mitochondrial dysfunction, telomere loss, altered gene expression, and oxidative damages. Those factors affecting the aging process were implicated in hypertension, diabetes, lipid metabolic disorder, heart failure, smoking and psychological stress and so on. Subjects with those disorders are manifested the increased insulin resistance and oxidative stress which are more likely to accelerate aging, atherosclerosis and premature death. Both are also associated with accelerated telomere attrition in leucocytes and chronicle the cumulative burden of oxidative stress and inflammation over a life course. Here, recent evidences including our data about the relationship between telomere attrition and age-related disorders are introduced. Finally, we identify improving life-style as well as pharmacological interventions as potent anti-aging effects to be important for keeping of healthy long life.

CD38, CD157, and RAGE as Molecular Determinants for Social Behavior.

Recent studies provide evidence to support that cluster of differentiation 38 (CD38) and CD157 meaningfully act in the brain as neuroregulators. They primarily affect social behaviors. Social behaviors are impaired in Cd38 and Cd157 knockout mice. Single-nucleotide polymorphisms of the CD38 and CD157/BST1 genes are associated with multiple neurological and psychiatric conditions, including autism spectrum disorder, Parkinson's disease, and schizophrenia. In addition, both antigens are related to infectious and immunoregulational processes. The most important clues to demonstrate how these molecules play a role in the brain are oxytocin (OT) and the OT system. OT is axo-dendritically secreted into the brain from OT-containing neurons and causes activation of OT receptors mainly on hypothalamic neurons. Here, we overview the CD38/CD157-dependent OT release mechanism as the initiation step for social behavior. The receptor for advanced glycation end-products (RAGE) is a newly identified molecule as an OT binding protein and serves as a transporter of OT to the brain, crossing over the blood-brain barrier, resulting in the regulation of brain OT levels. We point out new roles of CD38 and CD157 during neuronal development and aging in relation to nicotinamide adenine dinucleotide+ levels in embryonic and adult nervous systems. Finally, we discuss how CD38, CD157, and RAGE are crucial for social recognition and behavior in daily life.

A1 adenosine receptor upregulation accompanies decreasing myocardial adenosine levels in mice with left ventricular dysfunction.

BACKGROUND: It is well known that adenosine levels are increased during ischemia and protect the heart during ischemia/reperfusion. However, less is known about the role of adenosine-adenosine receptor (AR) pathways in hearts with left ventricular dilation and dysfunction. Therefore, we assessed adenosine levels and selective AR expression in transgenic mice with left ventricular systolic dysfunction secondary to overexpression of tumor necrosis factor-alpha (TNF 1.6). METHODS AND RESULTS: Cardiac adenosine levels were reduced by 70% at 3 and 6 weeks of age in TNF 1.6 mice. This change was accompanied by a 4-fold increase in the levels of A1-AR and a 50% reduction in the levels of A2A-AR. That the increase in A1-AR density was of physiological significance was shown by the fact that chronotropic responsiveness to the A1-AR selective agonist 2-chloro-N6-cyclopentanyladenosine was enhanced in the TNF 1.6 mice. Similar changes in adenosine levels were found in 2 other models of heart failure, mice overexpressing calsequestrin and mice after chronic pressure overload, suggesting that the changes in adenosine-AR signaling were secondary to myocardial dysfunction rather than to TNF overexpression. CONCLUSIONS: Cardiac dysfunction secondary to the overexpression of TNF is associated with marked alterations in myocardial levels of adenosine and ARs. Modulation of the myocardial adenosine system and its signaling pathways may be a novel therapeutic target in patients with heart failure.

A percentage analysis of the telomere length in Parkinson's disease patients.

Telomeres are the repeated sequences at the chromosome ends which undergo shortening with cell division. The telomere shortening of the peripheral leukocytes is also facilitated by enhanced oxidative stress in various kinds of disease including ischemic heart disease, diabetes mellitus, apoplexy, and Alzheimer's disease. Telomere shortening in Parkinson's disease (PD) has not yet been reported. The pathogenesis for PD is also regarded to be associated with oxidative stress. We investigated 28 Japanese male PD patients ages 47-69. Although we could not find a statistical difference in the mean telomere length of peripheral leukocytes between the PD patients and the control participants, we found the mean telomere lengths to be shorter than 5 kb in only the PD patients and a significant PD-associated decrease in the telomeres with a length ranging from 23.1 to 9.4 kb in the patients in their 50s and 60s. These observations suggest that telomere shortening is accelerated in PD patients in comparison to the normal population.

Chemical constituents of Aristolochia constricta: antispasmodic effects of its constituents in guinea-pig ileum and isolation of a diterpeno-lignan hybrid.

Twenty constituents were isolated from the n-hexane and chloroform extracts of Aristolochia constricta, a plant whose aerial parts have been used empirically in folk medicine for various purposes. The inhibitory effects of these constituents on smooth muscle contraction in isolated guinea-pig ileum were studied in order to observe their antispasmodic effects. 3,4-Dibenzyldihydrofuran-type lignans [(-)-cubebin, (-)-hinokinin, and (-)-pluviatolide] and a kaurene-type diterpene [(-)-kaur-16-en-19-oic acid] were isolated as active principals. They inhibited electrically induced and acetylcholine-induced contraction in the isolated guinea-pig ileum. In addition, 9- O-[(-)-kaur-15-en-17-oxyl]cubebin was isolated as a new diterpeno-lignan hybrid, although this constituent did not exhibit antispasmodic activity.

Effects of cruciferous allyl nitrile on phase 2 antioxidant and detoxification enzymes.

BACKGROUND: High intake of cruciferous vegetables has been associated with lower risk of various cancers, and the cancer preventive effect of the vegetables has been associated with their high levels of glucosinolates. The hydrolysis of glucosinolates results in the generation of bioactive compounds, including allyl nitrile which we previously found to be an active inducer of some phase 2 enzymes. In this study, we further explored the inductive ability of this nitrile in light of increasing evidence that antioxidants delay or prevent the development of cancer. MATERIAL/METHODS: Groups of 6 mice were administered subtoxic doses of allyl nitrile (5, 50, 100 or 200 micromol/kg) or vehicle-distilled water daily for 5 days by gastric intubation. On the sixth day, the animals were sacrificed for examination of enzyme activities in their tissues. Enzymes tested were thioredoxin reductase (TR), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase. RESULTS: Allyl nitrile increased the activity of TR in the liver, kidneys and rectum at doses of 100-200 micromol/kg/day, and GPx in the kidneys and small intestine at 50 to 200 micromol/kg/day, while in the colon, alone, it decreased the activities of GR and catalase at doses of 200 and 100-200 micromol/kg/day, respectively not. CONCLUSIONS: The present results suggest an involvement of allyl nitrile in antioxidant defense in the body, except for the colon.

Pueraria mirifica phytoestrogens improve dyslipidemia in postmenopausal women probably by activating estrogen receptor subtypes.

Impaired lipid metabolism is an important health problem in postmenopausal women with insufficient estrogens, because dyslipidemia is a risk factor for development of atherosclerosis and the incidence of cardiovascular disease markedly increases after menopause. Pueraria mirifica (PM), a Thai herb, has been noticed as a source of phytoestrogens, estrogen-mimicking plant compounds. However, the clinical effects of PM on lipid metabolism and the underlying molecular mechanisms remain undetermined. Therefore, we examined the effects of PM on serum lipid parameters in a randomized, double-blind, placebo-controlled clinical trial. Nineteen postmenopausal women were randomly assigned to receive oral administration of PM powder or placebo. After 2 months of treatment, the PM group showed a significant increase in serum concentrations of high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-1 (34% and 40%, respectively), and a significant decrease in low-density lipoprotein (LDL) cholesterol and apo B (17% and 9%, respectively), compared with baseline measurements. Moreover, significant decreases were observed in the ratios of LDL cholesterol to HDL cholesterol (37%) and apo B to apo A-1 (35%). Next, we determined the effects of PM phytoestrogens on the activation of estrogen receptor (ER)-mediated transactivation by transient expression assays of a reporter gene in cultured cells. Among PM phytoestrogens, miroestrol and coumestrol enhanced both ERalpha- and ERbeta-mediated transactivation, whereas other phytoestrogens, including daidzein and genistein, preferentially enhanced ERbeta-mediated transactivation. In conclusion, PM has a beneficial effect on lipid metabolism in postmenopausal women, which may result from the activation of gene transcription through selective binding of phytoestrogens to ERalpha and ERbeta.

Cardiac Sarcoidosis Concomitant with Large-vessel Aortitis Detected by 18F-fluorodeoxyglucose Positron Emission Tomography.

We herein report a case of concurrent cardiac sarcoidosis and large-vessel aortitis detected by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and followed up during immunosuppressive therapy. After high-dose prednisolone administration (1 mg/kg), serial FDG-PET showed that almost all of the abnormal FDG uptake in the heart and extracardiac region, including the abdominal to bilateral iliac arteries, had been disappeared. During the tapering of prednisolone, additive methotrexate therapy was needed to treat the recurrence of cardiac sarcoidosis. FDG-PET is a useful tool for detecting cardiac sarcoidosis concomitant with large-vessel aortitis and monitoring the effectiveness of immunosuppressive therapy.

A multi-institutional study of secondary check of treatment planning using Clarkson-based dose calculation for three-dimensional radiotherapy.

PURPOSE: As there have been few reports on quantitative analysis of inter-institutional results for independent monitor unit (MU) verification, we performed a multi-institutional study of verification to show the feasibility of applying the 3-5% action levels used in the U.S. and Europe, and also to show the results of inter-institutional comparisons. METHODS: A total of 5936 fields were collected from 12 institutions. We used commercial software employing the Clarkson algorithm for verification after a validation study of measurement and software comparisons was performed. The doses generated by the treatment planning systems (TPSs) were retrospectively analyzed using the verification software. RESULTS: Mean ±â€¯two standard deviations of all locations were 1.0 ±â€¯3.6%. There were larger differences for breast (4.0 ±â€¯4.0%) and for lung (2.5 ±â€¯5.8%). A total of 80% of the fields with differences over 5% of the action level involved breast and lung targets, with 7.2 ±â€¯5.4%. Inter-institutional comparisons showed various systematic differences for field shape for breast and differences in the fields were attributable to differences in reference point placement for lung. The large differences for breast and lung are partially attributable to differences in the methods used to correct for heterogeneity. CONCLUSIONS: The 5% action level may be feasible for verification; however, an understanding of larger differences in breast and lung plans is important in clinical practice. Based on the inter-institutional comparisons, care must be taken when determining an institution-specific action level from plans with different field shape settings and incorrectly placed reference points.

Early downregulation of IGF-I decides the fate of rat retinal ganglion cells after optic nerve injury.

Retinal ganglion cells (RGCs) die by apoptosis after optic nerve injury. A number of reports have separately shown changes in pro-apoptotic proteins such as the Bcl-2 family members following optic nerve injury. However, induction time of these apoptotic signals has not been identified due to different treatments of the optic nerve, and insufficient time intervals for measurements. Therefore, the stream of cell death signals is not well understood. In the present study, we systematically reinvestigated a detailed time course of these cell death/survival signals in the rat retina after optic nerve crush, to determine the signal cascade leading to RGC apoptosis. The most conspicuous changes detected in the retina were the rapid inactivation of phospho-Akt and phospho-Bad proteins 2-3 days after optic nerve damage, and the subsequent gradual activation of Bax protein and caspase-3 activity accompanied by cell loss of RGCs 6 days after nerve injury. Cellular localization of these molecular changes was limited to RGCs. Furthermore, amount of insulin-like growth factor-I (IGF-I), an activator of the phosphatidyl inositol-3-kinase (PI3K)/Akt system, was initially decreased from RGCs 1-2 days just prior to the inactivation of phospho-Akt by optic nerve crush. Conversely, supplementation with IGF-I into the rat retina induced upregulation of phospho-Akt expression and cell survival of RGCs both in vitro and in vivo. Thus, injury to the optic nerve might induce early changes in cellular homeostasis with a plausible loss of trophic support for injured RGCs. Actually, IGF-I drastically enhanced neurite outgrowth from adult rat RGCs via a wortmannin-dependent mechanism in a retinal explant culture. Our data strongly indicate that IGF-I is a key molecule that induces RGC apoptosis or RGC survival and regeneration in the retina during the early stage of optic nerve injury.