bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cholesterol Diets on Vascular Function and Atherogenesis in Rabbits
Authors: Sun Yi‐Ping , Lu Nancy C. , Parmley William W. , Hollenbeck Clarie B.
Published: August 2010

Abstract. Vascular endothelial dysfunction is an important early event in atherogenesis. To evaluate the effects of different levels of cholesterol‐containing diets on vascular function and atherogenesis, 17 New Zealand White male rabbits were randomized into four groups: Control with noncholesterol, 10‐week 0.5% (0.5C‐10) or 1% cholesterol (1C‐10), and 14‐week 0.5% cholesterol (0.5C‐14) feedings. After 10 or 14 weeks, the aortas were harvested for studies of vascular endothelial function and percentage surface lipid lesions. The 0.5% and 1% cholesterol feedings resulted in the same degree of hypercholesterolemia independent of the level and period of cholesterol feeding. There was a decreased trend in vascular endothelial‐dependent relaxation to acetylcholine in cholesterol‐fed rabbits. Fourteen‐week cholesterol feeding induced the least vascular dilation at a concentration of 10−7M acetylcholine (–38 ± 3%, –23 ± 4%, –23 ± 2%, and –15 ± 5% in control, 0.5C‐10, 1C‐10, and 0.5C‐14 groups, respectively, P = 0.003). More cumulative exposure of arterial walls to cholesterol induced more surface lipid lesions in the aorta (r = 0.877, P < 0.001). There was a negative relationship between aortic lesions and vasodilation (r = –0.557, P = 0.020 for calcium ionophore; r = –0.463, P = 0.062 for acetylcholine). We conclude that the 0.5% and 1% cholesterol feedings induce similar degrees of hypercholesterolemia. However, aortic lipid lesions and vascular reactivity are dependent on cumulative exposure to cholesterol rather than serum cholesterol level only. Furthermore, decreased vascular endothelial relaxation in cholesterol‐fed rabbits was related to lipid plaques in the aorta.
Effects of Inositol, LiCl, and Heparin on the Antibody Responses to SRBC by Normal and Immunodeficient XID Mice
Authors: Tyan Marvin L.
Published: August 2010

Abstract. Spleen cells from naïve adult immunocompetent and immunodeficient XID mice were cultured on agar containing sheep red blood cells (SRBC) with and without myo‐inositol, scyllo‐inositol, lithium chloride, or heparin, and after 1 or 2 days the number of colonies of antiSRBC antibody–forming cells (PFC) were determined. It was found that myo‐inositol and scyllo‐inositol at one‐tenth the concentration were equally effective in increasing the number of specific PFC. Myo‐inositol, scyllo‐inositol, and lithium chloride accelerated the appearance of direct foci in cultures of spleen cells from normal and XID mice. When heparin was added to cultures of XID spleen cells, PFC were found to be increased on Day 1; however, PFC and foci were not increased in cultures of spleen cells from competent mice until 1 day later. The addition of combinations of these agents to cultures of spleen cells had no positive or negative effect on the generation of foci or PFC. Normal mice given heparin intraperitoneally with SRBC had increased splenic PFC on Days 3 and 4 but not on Day 7. The results suggest that these agents modulate B‐cell responses by increasing the rate of proliferation and/or secretion through a signaling pathway(s) distal to, or more likely, independent of Bruton's tyrosine Kinase (BTK). It is not clear that the mechanism is the same with each agent.
Tumor Necrosis Factor Induces Resistance of Macrophages to Legionella pneumophila Infection
Authors: McHugh Shannon L. , Newton Catherine A. , Yamamoto Yoshimasa , Klein Thomas W. , Friedman Herman
Published: August 2010

Abstract. Legionella pneumophila is an ubiquitous opportunistic intracellular pathogen that replicates readily in thioglycollate‐elicited peritoneal macrophages from genetically susceptible A/J mice. Treatment of macrophage cultures in vitro with tumor necrosis factor–α (TNF‐α) induced resistance of the macrophages to infection by Legionella as compared with control macrophages treated with medium alone. Addition of small amounts of monoclonal antibody to TNF‐α restored susceptibility of the macrophages. Furthermore, antibody to the proinflammatory cytokine interleukin‐1 (IL‐1) α/β increased resistance, but recombinant IL‐1 had little effect. Such decreased susceptibility to Legionella growth in anti‐IL‐1 antibody–treated cultures corresponded with enhanced levels of TNF‐α in the supernatants of the treated cells. An antibody to another proinflammatory cytokine with known immunoregulatory properties (i.e., IL‐6) had little or no effect on the ability of the macrophages to be infected by Legionella and, furthermore, treatment with recombinant IL‐6, similar to recombinant IL‐1, did not modify the ability of the cells to be infected in vitro. These results indicate that TNF‐α is important in controlling L. pneumophila replication, and IL‐1 can regulate TNF‐α levels, affecting susceptibility of macrophages to infection with an intracellular opportunistic pathogen like Legionella.
Host Immune Response to Intracellular Bacteria: A Role for MHC‐Linked Class‐Ib Antigen‐Presenting Molecules
Authors: Soloski Mark J. , Szperka Michael E. , Davies Adrian , Wooden Stacey L.
Published: August 2010

Abstract. MHC‐linked class‐Ib molecules are a subfamily of class‐I molecules that display limited genetic polymorphism. At one time these molecules were considered to have an enigmatic function. However, recent studies have shown that MHC‐linked class‐Ib molecules can function as antigen presentation structures that bind bacteria‐derived epitopes for recognition by CD8+ effector T cells. This role for class‐Ib molecules has been demonstrated across broad classes of intracellular bacteria including Listeria moncytogenes, Salmonella typhimurium, and Mycobacterium tuberculosis. Additionally, evidence is emerging that MHC‐linked class‐Ib molecules also serve an integral role as recognition elements for NK cells as well as several TCR α/β and TCR γ/δ T‐cell subsets. Thus, MHC‐linked class‐Ib molecules contribute to the host immune response by serving as antigen presentation molecules and recognition ligands in both the innate and adaptive immune response to infection. In this review, we will attempt to summarize the work that supports a role for MHC‐linked class‐Ib molecules in the host response to infection with intracellular bacteria.
Low‐Protein Diet Changes Thyroid Function in Lactating Rats
Authors: Ramos Cristiane Fonte , Teixeira Cintia Vilanova , Passos Magna Cottini Fonseca , Pazos‐Moura Carmen Cabanellas , Lisboa Patricia Cristina , Curty Flavio Henrique , De Moura Egberto Gaspar
Published: August 2010

Abstract. Lactating rats were fed with free access to an 8% protein‐restricted diet (PR); the control group was fed a 23% protein diet (C). An energy‐restricted (pair‐fed) group was given the same food as the animals in the control group, but the amounts of food consumed by both PF and PR were about the same. The body weight and serum albumin concentration of PR and PF dams were significantly (P < 0.05) lower than that of the controls. The PR group had a significant increase in serum‐free triiodothyronine (FT3) concentration, 24‐hr mammary gland and milk radioiodine (I131) uptake (67%, 278%, and 200%, respectively) as compared with the controls. On the other hand, those animals had a significantly lower serum‐free thyroxine (FT4) concentration and 2‐ and 24‐hr thyroid I131 uptake (67%, 64%, and 74%, respectively). Protein malnutrition during lactation did not alter thyroid or liver 5′‐deiodinase activity significantly. However, PF dams had a significantly lower (25%) thyroid 5′‐deiodinase activity. These data suggest that protein‐restricted lactating dams had an adaptive change in the thyroid function, which could be important to increase the transference of iodine or triiodothyronine through the milk to their pups and prevent sequelae of neonatal hypothyroidism.
Detection of Antigen‐Specific Human Serum Proteins Related to the T‐Cell Receptor in Infectious Disease and in an Immune Response to Milk Proteins or Chemicals
Authors: Little Colin H. , Georgiou George M. , Fey Geoffrey , Ravindran Balachandran , Levine Joel , Ogedegbe Henry , Yamase Harold , Cone Robert E.
Published: August 2010

Abstract. A monoclonal IgG2 antibody, MG3C9–1 A12, was prepared by immunization of mice with human serum Cohn Fraction III proteins enriched for TCR Ca+ proteins. MG3C9–1 A12 bound to Mr 28,000, antigen‐specific TCR Ca+, β−, and TCR Ca+, β+ serum proteins associated with TGF‐β1, 2. The IgG2 monoclonal antibody also bound to T‐lymphocyte proteins but did not bind to B lymphocyte proteins, human albumin, IgM, IgG, IgA, or TGF‐β1, 2, 3 immunogenic peptides. Monoclonal MG3C9–1 A12 detected TCR‐related proteins specific for filarial extract, milk proteins, or benzoic acid in the sera of individuals with chronic or asymptomatic filariasis, milk intolerance, or sensitivity to toluene, respectively. TCR‐related serum proteins were also detected intracellularly in mononuclear cells in frozen sections of ileum from a patient with milk intolerance and reactive mesenteric lymph nodes from a patient with a gastric ulcer. The results suggest that antigen‐specific TCR‐related serum proteins may be elevated during an immune response to oral, environmental, or infectious stimuli.
Ovarian Steroidogenic Responsiveness to Exogenous Gonadotropin Stimulation in Young and Middle‐Aged Female Rats
Authors: Chern Bey‐Ying , Chen You‐Hsin Jean , Hong Long‐Sheng , LaPolt Philip S.
Published: August 2010

Abstract. Reproductive aging in the female rat is associated with gradual declines in LH secretion and ovarian progesterone (P) production. This study examined whether the influences of aging on P levels reflect decreased ovarian responsiveness to gonadotropin stimulation, as opposed to changes in gonadotropin release. Young and middle‐aged regularly cyclic female rats received sodium pentobarbital to block endogenous proestrous luteinizing hormone (LH) surges, followed by administration of various doses of human chorionic gonadotropin (hCG). Similar treatments were performed in middle‐aged acyclic persistent‐estrous (PE) females. Injection of hCG resulted in equivalent plasma hCG levels in each treatment group. At the lowest hCG dose tested, a significant rise in plasma P levels was observed in middle‐aged cyclic rats, but not in young cyclic or middle‐aged PE females. This unexpected finding may reflect accelerated follicular development in middle‐aged cyclic females, as suggested by a previous study. At the intermediate dose, young and middle‐aged cyclic but not PE rats displayed significantly increased P in response to hCG. At the highest dose tested, all three groups of rats displayed increased P levels after hCG stimulation. However, P concentrations were significantly lower in middle‐aged PE than regularly cyclic females. Northern and slot blot hybridization analyses revealed that ovarian mRNA levels for cytochrome P450 side‐chain cleavage, the rate‐limiting enzyme in P synthesis, were markedly reduced in PE rats following hCG stimulation. These findings indicate that ovarian responsiveness to gonadotropin stimulation is impaired in middle‐aged PE, but not regularly cyclic rats, and suggest influences of cycle status on the biochemical and molecular mechanisms regulating ovarian steroid production. Furthermore, these findings reveal that attenuated P production in middle‐aged proestrous rats is due to attenuated preovulatory LH surges, rather than decreased ovarian sensitivity to LH.
Antioxidative Effects of Melatonin in Protection Against Cellular Damage Caused by Ionizing Radiation
Authors: Karbownik Małgorzata , Reiter Russel J.
Published: August 2010

Abstract. Ionizing radiation is classified as a potent carcinogen, and its injury to living cells is, to a large extent, due to oxidative stress. The molecule most often reported to be damaged by ionizing radiation is DNA. Hydroxyl radicals (•OH), considered the most damaging of all free radicals generated in organisms, are often responsible for DNA damage caused by ionizing radiation. Melatonin, N‐acetyl‐5‐methoxytryptamine, is a well‐known antioxidant that protects DNA, lipids, and proteins from free‐radical damage. The indoleamine manifests its antioxidative properties by stimulating the activities of antioxidant enzymes and scavenging free radicals directly or indirectly. Among known antioxidants, melatonin is a highly effective scavenger of •OH. Melatonin is distributed ubiquitously in organisms and, as far as is known, in all cellular compartments, and it quickly passes through all biological membranes. The protective effects of melatonin against oxidative stress caused by ionizing radiation have been documented in in vitro and in vivo studies in different species and in in vitro experiments that used human tissues, as well as when melatonin was given to humans and then tissues collected and subjected to ionizing radiation. The radioprotective effects of melatonin against cellular damage caused by oxidative stress and its low toxicity make this molecule a potential supplement in the treatment or co‐treatment in situations where the effects of ionizing radiation are to be minimized.
Catechins Delay Lipid Oxidation and α‐Tocopherol and β‐Carotene Depletion Following Ascorbate Depletion in Human Plasma
Authors: Lotito Silvina B. , Fraga Cesar G.
Published: August 2010

Abstract. Blood plasma was incubated with 50 mM AAPH [2,2′‐azobis‐(2‐amidinopropane) hydrochloride] in the absence or presence of catechins (5–100 μM). Lipid oxidation was evaluated by measuring the formation of 2‐thiobarbituric acid reactive substances (TBARS). The concentration of α‐tocopherol (AT), β‐carotene (BC), ascorbic acid (AA), and catechins was determined by reverse phase high performance liquid chromatography (HPLC) with electrochemical detection. All the assayed catechins inhibited plasma TBARS formation. Based on the calculated IC50, the order of effectiveness was: epicatechin gallate (ECG) > epigallocatechin gallate (EGCG) > epigallocatechin (EGC) > epicatechin (EC) > catechin (C). Catechins protected plasma AT and BC from AAPH‐mediated oxidation. The order of effectiveness for AT protection was ECG > EGCG > EC = C > EGC; and for BC protection, the order was EGCG > ECG > EGC > > EC > C. The addition of catechins modified the kinetics of TBARS formation and AT depletion, but the rate of AA depletion was not affected. Catechin oxidation did not start until the complete depletion of AA, and it preceded AT depletion. These results indicate that catechins are effective antioxidants in human blood plasma, delaying the lipid oxidation and depletion of endogenous lipid‐soluble antioxidants (AT and BC).
Female House Mice Develop a Unique Ovarian Lesion in Colonies That Are at Maximum Population Density
Authors: Chapman John C. , Christian John J. , Pawlikowski Mary Ann , Yasukawa Norie , Michael Sandra D.
Published: August 2010

Abstract. Colonies of house mice reach maximum population density in 120–180 days, irrespective of cage size and initial number of colonizing animals. Reproduction ceases because the females become aggressive and unreceptive to mating. The aggressive behavior is correlated with elevated levels of testosterone (T) and corticosterone (B) (Chapman et al., Phys Behav 64:529–533, 1998). In two of seven strains of mice, females developed ovarian lesions. The occurrence of the lesion in one strain was correlated with the age of the animal and duration of the study. In the second strain, cage size was the determining factor. Lesioned ovaries weighed significantly more than nonlesioned ovaries. The lesion consisted of accumulations of luteal membrane and organelle fragments, and other cellular debris, suggestive of incomplete and prolonged luteolysis. Electron microscopic (EM) analyses revealed the presence of deposits of permanganate‐resistant congophilic amyloid fibrils in the intima and smooth muscle cells of luteal thecal arteries.

Population females had thymus glands and uteri that weighed significantly less than the same organs from females housed in the breeding colony, whereas the adrenal glands from the population females weighed significantly more.

It is proposed that the female aggression is due to high levels of T. It is also proposed that the high levels of B suppress the immune cells involved in normal luteolysis and contribute to the incomplete and prolonged luteolysis.
Age‐Related Changes in Rat Hepatic Acetyl‐Coenzyme A Carboxylase
Authors: Thampy K. George , Haas Michael J. , Mooradian Arshag D.
Published: August 2010

Abstract. Acetyl‐CoA carboxylase (ACC) catalyzes the rate‐limiting step in the synthesis of long‐chain fatty acids. Since aging influences adiposity, we studied the activity of ACC and its mRNA content in livers of 4‐, 12‐, and 24‐month‐old male Fischer 344 rats. The mean (± SEM) activity of ACC (mU/mg protein) in liver homogenates from 4‐month‐old rats was 1.01 ± 0.14. There was an 80% increase in activity (1.83 ± 0.27) in 12‐month‐old rats (P < 0.01). However, there was significantly less activity (0.46 ± 0.06) in livers of 24‐month‐old rats (P < 0.001). The total activity of ACC (per g liver) followed the same trend. The enzyme from all age groups was purified by avidin‐affinity chromatography. The purified preparation migrated as a major protein band (Mr 262,000) on sodium dodecyl sulfate (SDS)‐polyacrylamide gels. The specific activity of the purified preparation was 1.5, 1.8, and 1.8 U/mg for 4‐, 12‐, and 24‐month‐old rats, respectively. The alkali‐labile phosphate content was 5.66 ± 0.17, 5.64 ± 0.21, and 6.21 ± 0.35 mols Pi/mole subunit for 4‐, 12‐, and 24‐month‐old rats, respectively. These age‐related differences were not significant. The hepatic ACC mRNA measured by ribonuclease protection assay when corrected for G3PDH mRNA was significantly reduced in 24‐month‐old rats (0.24 ± 0.03) compared with 12‐month‐old (0.58 ± 0.04) or 4‐month‐old rats (0.43 ± 0.007) P < 0.01. In summary: (i) Aging in rats is associated with significant changes in ACC activity; (ii) the purified ACC preparations from the three age groups had similar specific activity and similar phosphate content; and (iii) the changes in ACC mRNA content of the liver paralleled the changes in total enzyme activity when 12‐month‐old rats were compared with 24‐month‐old rats whereas the increase in ACC activity in 12‐month‐old rats compared with 4‐month‐old rats could not be ascribed to changes in hepatic mRNA levels. These results indicate that the age‐related changes in hepatic ACC occur at a post‐translational level during early years of aging and at a pretranslational level at late states of senescence. These changes may contribute to the age‐related alterations in body adiposity.
Induction of Hepatic Insulin‐Like Growth Factor Binding Protein‐1 (IGFBP‐1) in Rats by Dietary n‐6 Polyunsaturated Fatty Acids
Authors: Ghoshal Amit K. , Xu Zhaoming , Wood Geoffrey A. , Archer Michael C.
Published: August 2010

Abstract. The insulin‐like growth factors (IGFs) are mitogenic polypeptides that have been linked to a variety of normal physiological processes as well as neoplasia. Overexpression of several components of the IGF system is associated with hepatocarcinogenesis in humans and rodents. In rat liver, diets rich in n‐6 polyunsaturated fatty acid (PUFA) enhance the development of preneoplastic lesions and tumors. Therefore, the objective of this study was to determine the effect of these dietary fatty acids on the hepatic expression of the various components of the IGF system. The mRNA levels of IGF‐1 and the type 1 receptor were not different in livers of rats fed a diet containing 20% corn oil (CO) compared with those fed 5% CO. Analysis of the IGF binding proteins revealed that insulin‐like growth factor binding protein‐1 (IGFBP‐1) levels were altered by the amount and type of dietary fat. A 2.5‐fold induction of IGFBP‐1 mRNA occurred within 1 week after the animals were fed the 20% corn oil diet compared with those fed 5% CO and was further enhanced to over 6‐fold after 1 month. Furthermore, IGFBP‐1 protein was only detectable in the livers of animals fed the 20% CO diet. Induction of IGFBP‐1 mRNA (4.5‐fold) also occurred in rats fed a high‐fat diet containing safflower (rich in n‐6 PUFAs) compared with those fed a high‐fat diet containing menhaden oil (rich in n‐3 PUFAs). The induction of IGFBP‐1 mRNA was independent of serum insulin levels and the development of insulin resistance. Since IGFBP‐1 mRNA is upregulated in regenerating liver, we reasoned that the induction of IGFBP‐1 mRNA may be associated with an increase in cell proliferation; however, no difference was observed in the hepatic labeling index of rats fed the 20% CO compared with the 5% CO diet. In summary, these studies show a striking induction by dietary n‐6 PUFAs of hepatic IGFBP‐1, a protein that has been implicated in liver cancer development.
Anti‐Inflammatory Effects of Ergotamine in Steers
Authors: Filipov Nikolay M. , Thompson Frederick N. , Stuedemann John A. , Elsasser Theodore H. , Kahl Stanislaw , Stanker Larry H. , Young Colin R. , Dawe Donald L. , Smith Charles K.
Published: August 2010

Abstract. The objective of this experiment was to investigate whether the ergot alkaloid, ergotamine (ET), an alkaloid used to model fescue toxicosis in cattle, modifies the response of cattle to endotoxin (LPS) challenge. Steers (n = 16) were divided into the following treatment groups: control (C), ergotamine (ET), endotoxin (LPS), and ET + LPS. ET and ET + LPS groups received a single bolus intravenous injection of ET (40 μg · kg · body wt−1), whereas C and LPS steers received a single bolus injection of sterile vehicle. Thirty minutes after ET/vehicle administration, a single bolus intravenous injection of LPS (0.2 μg · kg · body wt−1) was given. Blood was collected at various time points for 48 hr post. Endotoxin increased rectal temperature (RT) and the circulating levels of tumor necrosis factor‐α (TNF‐α), cortisol, haptoglobin (Hp), thromboxane B2 (TXB2). The circulating Hp, TNF‐α, and TXB2 increases were blunted by pretreatment with ET compared with ET + LPS. Ergotamine by itself increased circulating cortisol and RT, whereas it decreased serum prolactin (PRL). Therefore, whereas administration of LPS at 0.2 μg/kg to steers resulted in an expected response, the combination of ET + LPS attenuated major effects of LPS alone. Thus, acute administration of ET appeared to be anti‐inflammatory as it decreased the inflammatory response to LPS, an effect likely driven at least in part by the ET‐caused cortisol increase.
Cell Death Induction by CTL: Perforin/Granzyme B System Dominantly Acts for Cell Death Induction in Human Hepatocellular Carcinoma Cells
Authors: Hayashida Midori , Kawano Hirokazu , Nakano Takeshi , Shiraki Katsuya , Suzuki Atsushi
Published: August 2010

Abstract. Cell death induction by cytotoxic T lymphocytes (CTLs) is an important thesis for the understanding of tumor immunotherapy. In the current study we investigated the molecular machinery of CTL‐induced cell death in human hepatocellular carcinoma cell lines (HCC lines). CTLs prepared from human peripheral blood induced cell death in all tested HCC lines. As the CTL‐induced death system, the effectiveness of Fas ligand/Fas and/or Perforin/Granzyme B systems has been suggested, whereas cell death induction by CTLs was shown independently on Fas expression in the current study. Using various tetrapeptide inhibitors for caspase and its associated factor, we additionally demonstrated that inhibitors for caspase 3 (Ac‐DEVD‐CHO) and caspase 8/granzyme B (Ac‐IETD‐CHO) suppressed CTL‐induced cell death, but an inhibitor for Fas‐activated serine proteinase, which acts for the caspase 3 activator, did not, suggesting that CTL‐induced cell death was initiated by the Perforin/Granzyme B system, rather than the Fas ligand/Fas system. On the basis of our current results, we report here that the Perforin/Granzyme B system acts dominantly for the cell death induction of HCC lines.
Effect of High‐Carbohydrate Feeding on Triglyceride and Saturated Fatty Acid Synthesis
Authors: Hudgins Lisa C.
Published: August 2010

Abstract. It has been known for decades that low‐fat, high‐carbohydrate diets can increase plasma triglyceride levels, but the mechanism for this effect has been uncertain. Recently, new isotopic and nonisotopic methods have been used to determine in vivo whether low‐fat, high‐carbohydrate diets increase triglyceride levels by stimulating fatty acid synthesis. The results of a series of studies in lean and obese weight‐stable volunteers showed that very‐low‐fat (10%), high‐carbohydrate diets enriched in simple sugars increased the fraction of newly synthesized fatty acids, along with a proportionate increase in the concentration of plasma triglyceride. Furthermore, the concentration of the saturated fatty acid, palmitate, increased and the concentration of the essential polyunsaturated fatty acid, linoleate, decreased in triglyceride and VLDL triglyceride. The magnitude of the increase in triglyceride varied considerably among subjects, was unrelated to sex, body mass index, or insulin levels, and was higher when fatty acid synthesis was constantly elevated rather than having a diurnal variation. It was notable that minimal stimulation of fatty acid synthesis occurred with higher fat diets (>30%) or with 10% fat diets enriched in complex carbohydrate. Public health recommendations to reduce dietary fat must take into account the distinct effects of different types of carbohydrate that may increase plasma triglycerides and fatty acid synthesis in a highly variable manner. The mediators and health consequences of this dietary effect deserve further study.
Nitric Oxide Donors
Authors: Yamamoto Tadahiko , Bing Richard J.
Published: August 2010

Abstract.Nitric oxide (NO) donors are pharmacologically active substances that release NOin vivoorin vitro. NO has a variety of functions such as the release of prostanoids, inhibition of platelet aggregation, effect on angiogenesis, and production of oxygen free radicals. This report discusses the chemical and pharmacological characteristics of NO donors, their effect on platelet function and cyclooxygenase, their cardiac action including myocardial infarction, and release of superoxide anions. This review stresses NO tolerance and the effect of NO donors on angiogenesis in myocardial infarction and in solid tumors.
Melatonin and the Synthesis of Vasopressin in Pinealectomized Male Rats
Authors: Juszczak Marlena , Bojanowska Ewa , Dabrowski Ryszard
Published: August 2010

Abstract. The pineal hormone, melatonin, is known to modify, under different experimental conditions, neurohypophysial hormone secretion in the rat. The aim of this study was to investigate the effect of melatonin on the vasopressin biosynthesis rate in the hypothalamus of either pinealectomized or sham‐operated rats, using the colchicine method. To estimate whether colchicine affects the function of the neurohypophysis in these animals, the neurohypophysial and plasma vasopressin levels were also measured.The vasopressin synthesis rate was increased after pineal removal, when compared with sham‐operated animals, and melatonin strongly inhibited the rise in the hormone synthesis due to pinealectomy. After pineal removal plasma vasopressin concentration was significantly elevated, and melatonin attenuated this effect. On the contrary, the neurohypophysial vasopressin content was significantly decreased after pinealectomy, but it was not further modified by melatonin.Thus, melatonin suppresses the synthesis and secretion of vasopressin in pinealectomized rats. The present results confirm our previous reports as to the inhibitory impact of the pineal on both vasopressin synthesis and release and suggest that melatonin may mediate the effect of the pineal gland on vasopressinergic neuron activity.
Avian Use of Wetlands in Reclaimed Minelands in Southwestern Indiana
Authors: Mulyani Yeni A. , DuBowy Paul J.
Published: August 2010

We studied the use of mineland wetlands by birds and the relationship between avian communities and wetland characteristics. Data were collected from 20 wetlands in Pike County, Indiana, and included wetland size, depth, water conductivity and salinity, aquatic macroinvertebrate abundance, vegetation, and bird use. Principal component analysis showed that physical variables could be explained by two principal component scores and that wetlands could be grouped on the basis of size and conductivity. Principal component analysis could not reduce vegetation variables to fewer principal component scores, meaning that wetland vegetation characteristics were independent of one another and did not show any trend. Most wetlands had low invertebrate density, and wetlands with higher invertebrate density had low invertebrate diversity. Wetlands with similar habitat characteristics (physical, vegetative, and invertebrate) did not necessarily show similarities in bird assemblages. Bird similarity index values ranged from 0 to 59%, implying that each wetland has its own bird community. Stepwise multiple regression analysis (α= 0.05) relating bird use and habitat characteristics showed that bird species richness increased with the species richness of submergent vegetation and was correlated negatively with the species richness of emergent vegetation. There was no significant relationship between bird species richness or bird species diversity and wetland size. The number of species within different avian guilds correlated with different habitat characteristics. The species richness of submergent plants was a factor that correlated positively with the number of species of several guilds (dabblers, wading birds, and plunge divers). Wetland age was not a factor that determined bird use.
Soil Moisture, Native Revegetation, andPinus lambertianaSeedling Survival, Growth, and Mycorrhiza Formation Following Wildfire and Grass Seeding
Authors: Amaranthus Michael P. , Trappe James M. , Perry David A.
Published: August 2010

Grass seeding is widely used for erosion control, but its consequences for soil and regeneration following fire have been measured only infrequently. This study investigates the effect of grass seeding on the type and extent of plant cover; soil moisture percentage; and moisture stress, survival, growth, and root‐tip and mycorrhiza formation ofPinus lambertiana(sugar pine) seedlings in a clearcut intensely burned by wildfire. One‐year‐old containerized sugar pine seedlings were planted in seeded and nonseeded areas in Spring 1988 and 1989 in the Longwood Fire area of southwest Oregon. In 1988, tree seedlings in grass‐seeded plots experienced intense competition from the grass, reduced root‐tip and mycorrhiza formation, low levels of soil moisture to meet evapotranspirational demand, high levels of mortality, and reduced growth. In 1989, however, the opposite was true: tree seedlings in nonseeded plots experienced competition from invading native annuals and perennials, low levels of soil moisture in summer, and higher levels of mortality. The studies we report here further indicate that, in an area characterized by extended summer drought, annual ryegrass impeded regeneration of sugar pine during the first season following the fire. Native species cover and richness have been significantly reduced in the seeded area and may affect long‐term soil stability, productivity, and conifer restoration. Seeding of annual ryegrass at high rates under these conditions would seem ill advised.
Prioritizing Watersheds in Oregon for Salmon Restoration
Authors: Nehlsen Willa
Published: August 2010

This paper describes an ecosystem approach (the Bradbury framework) to prioritizing watersheds for watershed restoration and salmon recovery, and gives an example of its application. The framework was applied at three spatial scales (in descending urder) to prioritize (1) river basins within the north coast geographic area of Oregon (USA), (2) watersheds within the Tillamook Bay basin, and (3) restoration activities at the watershed level, Implementing the framework identified the Nehalem and Tillamook Bay basins as high priority for the north coast of Oregon. Within the Tillamook Bay basin, the Wilson, Kilchis, and Trask river watersheds emerged as high priority. Preliminary analysis indicated that controlling sediment sources by addressing upland road conditions and allowing floodplain and riparian ecosystems to recover are highest priority protection and restoration activities within the Tillamook Bay basin. The sample application demonstrates that an ecosystem approach (the Bradbury framework) is particularly advantageous where data are limited, although previous identification of relatively intact areas is required. Implementing the framework is intended to lead to restoration of native species, but it may not provide immediate assistance for some species or populations of concern.
Applying a Two‐Stage System to Prioritize Riparian Restoration at the San Luis Rey River, San Diego County, California
Authors: Olson Craig , Harris Richard
Published: August 2010

A two‐stage system for selecting stream reaches and riparian communities for restoration was applied to the 80‐km San Luis Rey River below the Lake Henshaw dam in southern California. In the first satge, data from topographic quadrangles and aerial photographs were analyzed to define and classiy reaches. These analyses concluded that (1) 28 km of the river and adjacent floodplain were suitable for second‐stage evaluation of restoration needs and (2) 32 km met criteria for reference conditions at the stream reach scale and should be protected from further impacts. The remaining 20 km of the river and floodplain were considered unsuitable for restoration to reach‐scale reference conditions; individual sites may be restored under existing regulatory review. Second‐stage field sampling provided data on vegetation and floodplain landforms and substrate from more thatn 3000 plots within the 28 km of river and 1120 ha of floodplain selected for further Study. Classification of floristic samples stratified by landform/substrate class indicated six primary riparian communities on the floodplain, some associated with particular floodplain landform/substrate classes and others ubiquitous. Reference conditions for these communities were interpreted from the data. There were two major departures from reference conditions: tree‐dominated communities were less extensive than historic levels and exotic plants had significantly invaded some landforms and communities, displacing natural com‐munities. General goals would include restoration of tree communities and removal of exotics, with further consideration of site‐specific objectives. The results included estimates of the areas by community type re‐quiring restoration. The approach was developed for streams in the semi‐arid western United States, but it may be adapted for use elsewhere.
The Role of GIS in Selecting Sites for Riparian Restoration Based on Hyderology and Land Use
Authors: Russell Gordon D. , Hawkins Charles P. , O'Neill Michael P.
Published: August 2010

Successful long‐term wetland restoration efforts require consideration of hydrology and currounding land use during the site selection process. This article describes an approach to initial site selection in the San Luis Rey River watershed in southern California that uses watershed‐level information on basin topography and land cover to rank the potential suitability of all sites within a watershed for either preservation of restoration. This approach requires the use of a geographic information system (GIS)to map relative wetness and land cover within a watershed. Relative potential wetness values were derived from U.S. Geological Survey (USGS) 30‐m digital elevation models by calculating the flow that would potentially accumulate at all 30‐m × 30‐m pixels within the watershed. Land cover was derived from a Landsat scene covering the 1500 Km2 study area. We ranked sites (contiguous groups of pixels > 1 ha with similar land cover) in terms of their potential for restoration or preservation based on their wetness values (Iow, medium, and high), size, and proximity to existing riparian vegetation. Sites with medium or high wetness values and extant vegetation were identified as potential preservation sites. Agiricultural or barren sites with medium to high wetness were identified as potential restoration sites. Approximately 5500 ha (3.67% of the total watershed) were prioritized for preservation or resloration.
Classification and Mapping of Riparian Systems Using Airborne Multispectral Videography
Authors: Neale Christopher M. U.
Published: August 2010

Airborne multispectral videography has become a useful tool for classifying and mapping riparian vegetation because its spectral and digital format has high spatial resolution. This paper explains the processing steps and procedures required to use this type of spectral imagery for riparian vegetation classification and mapping. A description of the Utah State University airborne system is given, along with the image processing steps used for developing finalized products, because these are used in other articles in this volume. Examples of riparian applications using high‐resolution imagery are included.
Riparian Restoration: Current Status and the Reach to the Future
Authors: Landers Dixon H.
Published: August 2010

Nine Articles in the special issue of Restoration Ecology addrssing the subject of site selection for riparian restoration activities were critically examined for this review. The approaches described make significant and original contributions to the field of riparian restoration. All are interdisciplinary to some extent, often combining the fields of hydrology, geomorphology, and biology in the design of restorationss. A common component among the articles is that they take a broad view, if not a watershed view, of restoration site selection. The approaches can be generally descrobed as top‐down strategic approaches to siting restorations, as opposed to the more methods‐ and site‐driven bottom‐up, or tactical, approach. All the articles recognize the importance of developing endpoints related to the ecological function of riparian ecosystems. they succeed in their quest for these indicators of ecological function to varying degrees. The most common indica‐for used in these papers is riparian vegetation. Several additional elements of scientific investigation, if successfully pursued, could provide vital information and advance our understanding of riparian restoration: developing interdisciplinary approaches more fully; defining endpoints and reference conditions; implementing multiple scale approaches; viewing restorations as experimental ecosystem manipulations; developing a philosophy regarding exotic species; incorporating geographic information systems more often; and integrating science, society, and politics. the foundation provided by the contributions in this issue should provide a strong basis for the rapid advancement of future research in the area of riparian restoration.
The Importance of Board Quality in the Event of a CEO Death
Authors: Borokhovich Kenneth A. , Brunarski Kelly R. , Donahue Maura S. , Harman Yvette S.
Published: August 2010

We examine board quality and executive replacement decisions around deaths of senior executives. Stock price reactions to executive deaths are positively related to board independence. Controlling for such factors as the deceased's stockholdings, outside blockholdings, board size, and whether the deceased was a founder, board independence is the most significant factor explaining abnormal returns. Board independence is particularly important when there is no apparent successor and firm performance is poor. The results are consistent with independent boards being reluctant to discipline poorly performing incumbent managers, but nevertheless using the opportunity of an executive death to improve the quality of management.
Typologie et vitalité des communautés francophones minoritaires au Canada
Authors: LANGLOIS ANDRÉ , GILBERT ANNE
Published: August 2010

La vitalité des communautés francophones minoritaires du Canada, souvent expliquée par les conjonctures démographique et institutionnelle et par le contexte politico‐juridique, souffre encore d'une relative rareté de travaux empiriques illustrant l'action de ces facteurs à l'échelle des communautés. Cette rareté n'a pas permis jusqu'à maintenant d'élaborer une véritable analyse de l'effet de milieu sur la vitalité communautaire des minorités francophones. Notre étude se propose de mieux caractériser la présence francophone dans l'espace canadien hors Québec et, ce faisant, les milieux dans lesquels se construit la vie française au pays. Elle se fonde sur l'idée que la présence francophone, caractérisant un lieu donné, profite également d'un contexte plus large dont les ressources ne peuvent faire autrement que de rejaillir sur la communauté locale. À l'idée de présence localisée, nous ajoutons l'idée de présence contextualisée pour mieux faire le lien entre présence et vitalité communautaire. Une méthode originale est présentée ici qui permet de mettre en application cette complémentarité entre ces deux types de présence. Prenant la forme d'une typologie des milieux francophones minoritaires, elle fournit un nouvel éclairage sur la situation des populations francophones du Canada. Une analyse exploratoire des comportements linguistiques de ces populations selon les milieux issus de la typologie montre qu'une telle approche est susceptible d'ouvrir la voie à une meilleure appréhension de la vitalité communautaire en milieu minoritaire.
A spatial analysis of crime in Vancouver, British Columbia: a synthesis of social disorganization and routine activity theory
Authors: ANDRESEN MARTIN A.
Published: August 2010

This article investigates the spatial dimension of automotive theft, break and enter, and violent crime in Vancouver, British Columbia in 1996. The article uses and synthesizes social disorganization theory and routine activity theory as a theoretical backcloth and employs a spatial autoregressive regression procedure that accounts for spatial autocorrelation between crime rates and socio‐economic characteristics at the census tract level. Strong support is found for synthesizing these two most common spatial theories of crime. In particular, high unemployment (social disorganization theory) and the presence of young populations (routine activity theory) are the strongest predictors of criminal activity.
Urban pattern and land cover variation in the greater Toronto area
Authors: CONWAY TENLEY , HACKWORTH JASON
Published: August 2010

Recent epistemological shifts in environmental geography have created a space to consider the interactions between ecological and urban systems more seriously. While openness to thinking about urban ecosystems has increased in recent years, there remain fundamental gaps in our knowledge. For example, recent research has examined the impact of urban–rural gradients on ecological conditions, but major voids exist regarding the relationship between urban development patterns and land cover heterogeneity, particularly for new forms of urbanization. This article attempts to address some of these gaps by examining the relationship between urban pattern and land cover in the greater Toronto area (GTA). In particular, measures of urban pattern that reflect aspects of development density, grain and function, as well as socio‐economic characteristics, are systematically analyzed in relation to land cover heterogeneity. The regression analysis shows that multiple components of urban development pattern and socio‐economic conditions are correlated with vegetated land covers, while urban density variables are not related. These results indicate more detailed representations of urban pattern should be incorporated into future human–environmental interaction studies in cities.
Secondary migration of immigrants to Canada: an analysis of LSIC wave 1 data
Authors: NEWBOLD BRUCE
Published: August 2010

Immigrant settlement patterns are inherently more dynamic and diverse than those observed at the time of the census. In particular, it is likely that the intended settlement pattern (the destination stated to immigration officials at the time of entry) differs from the initial settlement pattern (the actual settlement location). At best, previous research has relied upon census data to illuminate these patterns, but only allowing a rough estimate of the dynamics of the system. As a result, spatial adjustments to the settlement process are only partially understood, with limited distinctions between recent and earlier arrivals, those who settled after a series of moves, or those that did not move at all after arrival. Using the recently released Longitudinal Survey of Immigrants to Canada (LSIC), this article examines differences in the evolution of the settlement pattern of immigrants in their first 6 months in Canada, potentially illuminating differences between the intended and initial settlement patterns. The advantage of this file is its longitudinal nature, allowing settlement location of the same individuals to be traced over time. Results suggest that while mobility is high among the newest arrivals, the intended and initial destinations are largely equivalent.
Income inequality across Canadian provinces in an era of globalization: explaining recent trends
Authors: BREAU SÉBASTIEN
Published: August 2010

In this article, I use panel data methods to investigate possible factors influencing recent trends in income inequality across Canadian provinces. The ratio of the income share of the highest‐to‐lowest quintiles and the Gini coefficient of total income are used as measures of inequality. Both point to rising levels of inequality from 1981 to 1999, especially during the 1990s, and the estimation results suggest that several factors have had significant effects on such an increase. In particular, an increase in international trade, technological change, educational heterogeneity, and the unemployment rate are found to contribute to greater inequality. Deindustrialization and declining government transfer payments to persons are also factors explaining the rise in inequality. In contrast, an increase in the female labour force participation rate appears to have dampened inequality. There is also some evidence of a negative association between de‐unionization and inequality while no significant association is found between inequality and other demographic shifts, such as immigration and the share of the population over the age of 65.
Comment réorganiser le réseau postal suisse? Une application de l'aide à la décision territoriale
Authors: JOERIN FLORENT , BOZOVIC GORAN
Published: August 2010

How to reorganize the Swiss postal network? A case study of spatial decision making‐support.

This article presents a case study of spatial decision making‐support in relation to the Swiss Post and its efforts to reorganize the postal network in eight Swiss cities. The first part of the article describes the methodology and highlights selected original elements used in the processing of geographic information (spatial analysis and multi‐criteria analysis). The second part, more analytical, examines the process used to apply the method defined in the previous section. Based on a constructivist approach of decision‐support, it explores the modes of interaction between available information and decision makers. The analysis shows that the decision maker is relatively difficult to identify since the decision making process includes a set of partial and dependent decisions that are taken by a diversity of people. In conclusion, geographic information played an important role, not only on the decision, but mainly in allowing decision makers to better understand spatial complexity