bluuebunny/crossref_metadata_2025 huggingface dataset:
Maintenance of lung myeloperoxidase activity in proestrus females after trauma-hemorrhage: upregulation of heme oxygenase-1
Authors: Yu Huang-Ping , Yang Shaolong , Hsieh Ya-Ching , Choudhry Mashkoor A. , Bland Kirby I. , Chaudry Irshad H.
Published: March 2006

Previous studies showed that females in the proestrus stage of the reproductive cycle maintain organ functions after trauma-hemorrhage. However, it remains unknown whether the female reproductive cycle is an important variable in the regulation of lung injury after trauma-hemorrhage and, if so, whether the effect is mediated via upregulation of heme oxygenase (HO)-1. To examine this, female Sprague-Dawley rats during diestrus, proestrus, estrus, and metestrus phases of the reproductive cycle or 14 days after ovariectomy underwent soft tissue trauma and then hemorrhage (mean blood pressure 40 mmHg for 90 min followed by fluid resuscitation). At 2 h after trauma-hemorrhage or sham operation, lung myeloperoxidase (MPO) activity and intercellular adhesion molecule (ICAM)-1, cytokine-induced neutrophil chemoattractant (CINC)-1, CINC-3, and HO-1 protein levels were measured. Plasma 17β-estradiol concentration was also determined. The results indicated that trauma-hemorrhage increased lung MPO activity and ICAM-1, CINC-1, and CINC-3 levels in ovariectomized females. These parameters were found to be similar to sham-operated animals in proestrus female rats subjected to trauma-hemorrhage. Lung HO-1 protein level in proestrus females was increased significantly compared with female rats subjected to trauma-hemorrhage during diestrus, estrus, and metestrus phases of the reproductive cycle and ovariectomized rats. Furthermore, plasma 17β-estradiol level was highest in proestrus females. Administration of the HO inhibitor chromium mesoporphyrin prevented the attenuation of shock-induced lung damage in proestrus females. Thus these findings suggest that the female reproductive cycle is an important variable in the regulation of lung injury following trauma-hemorrhage and that the protective effect in proestrus females is likely mediated via upregulation of HO-1.
Sex differences in morphine-induced analgesia of visceral pain are supraspinally and peripherally mediated
Authors: Ji Yaping , Murphy Anne Z. , Traub Richard J.
Published: March 2006

Increasing evidence suggests there is a sex difference in opioid analgesia of pain arising from somatic tissue. However, the existence of a sex difference in visceral pain and opioid analgesia is unclear. This was examined in the colorectal distention (CRD) model of visceral pain in the current study. The visceromotor response (vmr) to noxious CRD was recorded in gonadally intact male and female rats. Subcutaneous injection of morphine dose-dependently decreased the vmr in both groups without affecting colonic compliance. However, morphine was significantly more potent in male rats than females. Because systemic morphine can act at peripheral tissue and in the central nervous system (CNS), the source of the sex difference in morphine analgesia was determined. The peripherally restricted μ-opioid receptor (MOR) antagonist naloxone methiodide dose-dependently attenuated the effects of systemic morphine. Systemic administration of the peripherally restricted MOR agonist loperamide confirmed peripherally mediated morphine analgesia and revealed greater potency in males compared with females. Spinal administration of morphine dose-dependently attenuated the vmr, but there was no sex difference. Intracerebroventricular administration of morphine also dose-dependently attenuated the vmr with significantly greater potency in male rats. The present study documents a sex difference in morphine analgesia of visceral pain that is both peripherally and supraspinally mediated.
Elevated body temperature during sleep in orexin knockout mice
Authors: Mochizuki Takatoshi , Klerman Elizabeth B. , Sakurai Takeshi , Scammell Thomas E.
Published: March 2006

Core body temperature (Tb) is influenced by many physiological factors, including behavioral state, locomotor activity, and biological rhythms. To determine the relative roles of these factors, we examined Tb in orexin knockout (KO) mice, which have a narcolepsy-like phenotype with severe sleep-wake fragmentation. Because orexin is released during wakefulness and is thought to promote heat production, we hypothesized that orexin KO mice would have lower Tb while awake. Surprisingly, Tb was the same in orexin KO mice and wild-type (WT) littermates during sustained wakefulness. Orexin KO mice had normal diurnal variations in Tb, but the ultradian rhythms of Tb, locomotor activity, and wakefulness were markedly reduced. During the first 15 min of spontaneous sleep, the Tb of WT mice decreased by 1.0°C, but Tb in orexin KO mice decreased only 0.4°C. Even during intense recovery sleep after 8 h of sleep deprivation, the Tb of orexin KO mice remained 0.7°C higher than in WT mice. This blunted fall in Tb during sleep may be due to inadequate activation of heat loss mechanisms or sustained activity in heat-generating systems. These observations reveal an unexpected role for orexin in thermoregulation. In addition, because heat loss is an essential aspect of sleep, the blunted fall in Tb of orexin KO mice may provide an explanation for the fragmented sleep of narcolepsy.
Sex differences in inflammation and inflammatory pain in cyclooxygenase-deficient mice
Authors: Chillingworth Naomi L. , Morham Scott G. , Donaldson Lucy F.
Published: March 2006

There are two cyclooxygenase (COX) genes encoding characterized enzymes, COX-1 and COX-2. Nonsteroidal anti-inflammatory drugs are commonly used as analgesics in inflammatory arthritis, and these often inhibit both cyclooxygenases. Recently, inhibitors of COX-2 have been used in the treatment of inflammatory arthritis, as this isoform is thought to be critical in inflammation and pain. The objective of this study was to determine the effect of COX-1 or COX-2 gene disruption on the development of chronic Freund’s adjuvant-induced arthritis and inflammatory pain in male and female mice. The effect of COX-1 or COX-2 gene disruption on inflammatory hyperalgesia, allodynia, inflammatory edema, and arthritic joint destruction was studied. COX-2 knockout mice (COX-2 −/−) showed reduced edema and joint destruction in female, but not male, animals. In addition, neither male nor female COX-2 −/− mice developed thermal hyperalgesia or mechanical allodynia, either ipsilateral or contralateral to the inflammation. COX-1 gene disruption also reduced inflammatory edema and joint destruction in female, but not male mice, although females of both COX −/− lines did show some bony destruction. There was no difference in ipsilateral allodynia between COX-1 knockout and wild-type animals, but female COX-1 −/− mice showed reduced contralateral allodynia compared with male COX-1 −/− or wild-type mice. These data show that the gene products of both COX genes contribute to pain and local inflammation in inflammatory arthritis. There are sex differences in some of these effects, and this suggests that the effects of COX inhibitors may be sex dependent.
In vitro Modulation of Cytokine Expression by Enkephalin-Derived Peptides
Authors: Piva Marta , Moreno J. Ignacio , Jenkins Fameeka S. , Smith Jimmie K.A. , Thomas Jenetria L. , Montgomery Corey , Wilson Caleph B. , Sizemore Robert C.
Published: March 2006

Objective: We have previously reported that low doses of [Met5]-enkephalin (YGGFM, met-enkephalin) and two of its derivatives (YGG and YG) enhanced and accelerated delayed-type hypersensitivity responses while much higher doses of these compounds suppressed these reactions. Since the underlying mechanisms by which this and other immunomodulatory effects occur have not been established, this report explores the in vitro modulation of Th1 and Th2 cytokine expression by these peptides. Methods: Murine splenocytes were stimulated with suboptimal concentrations of concanavalin A (ConA) in serum-free medium in the absence or presence of met-enkephalin, YGG, YG, [des-Tyr1]-met-enkephalin (GGFM), [D-Ala2], [D-Met5]-enkephalin or tyrosine (Y). Cell-conditioned supernatants were assayed for interferon-γ (IFN-γ), interleukin (IL)-2 and IL-4. Relative IFN-γ and IL-2 mRNA levels were assessed by reverse transcription-polymerase chain reaction. The enhancing and suppressive effects of met-enkephalin and YG on IFN-γ production were also tested in the presence of naloxone (Nx). Results: Met-enkephalin, YGG and YG modulated the in vitro production of IFN-γ in a biphasic manner: stimulation at low doses and inhibition at high doses. At higher concentrations, met-enkephalin and YG also suppressed the production of IL-2 (type 1) and IL-4, a type 2 cytokine. Nx reversed the enhancing effect of met-enkephalin on IFN-γ production without affecting its suppressive action or any of the immunomodulating effects of YG. The degradation-resistant analog [D-Ala2], [D-Met5]-enkephalin enhanced IFN-γ production but did not suppress it. Conclusions: YG, the minimal molecular requirement for enhancement and suppression of immune responses by these metabolites, appears to mediate exclusively an across-the-board suppression via low-affinity, nonclassical, nonopioid receptors.
Reduced Primary T Lymphopoiesis in 3-Month-Old Lurcher Mice: Sign of Premature Ageing of Thymus?
Authors: Mandakova Petra , Sinkora Jiri , Sima Petr , Vozeh Frantisek
Published: March 2006

Objective: The nervous, endocrine and immune systems are functionally interconnected so that they may form a complex metasystem. Abnormalities within the neuroendocrine compartment can thus affect immune mechanisms and vice versa. The Lurcher-type mutation in mice has a profound impact on brain development in both homozygous and heterozygous individuals, which is followed by immune system changes. We investigated whether macroscopic changes in the thymus size were associated with an altered thymocyte development or with changes in peripheral T cell subset distribution. Methods: CD3, CD4 and CD8 expressions on thymocytes and peripheral T cells were compared with those in wild-type and Lurcher heterozygous C3H mice using surface immunophenotyping and flow cytometry. Galanthus nivalis agglutinin binding to thymocytes was measured at the same time. Results: While no differences between experimental groups were observed in 1-month-old mice, a critical reduction of numbers of thymocytes and namely double-positive cells occurred before the age of 3 months in Lurcher mice, which was accompanied by thymus involution. Interestingly, this was not accompanied by significant differences in major T subset proportions in the peripheral lymphatic tissue. Conclusions: We interpret our observations as hallmarks of premature thymus ageing in heterozygous Lurcher mice with only a marginal effect in the periphery in early adulthood.
Effect of Chronic Ethanol Feeding on 24-Hour Rhythms of Mitogenic Responses and Lymphocyte Subset Populations in Thymus and Spleen of Peripubertal Male Rats
Authors: Jiménez Vanessa , Cardinali Daniel P. , Alvarez María P. , Fernández María P. , Boggio Verónica , Esquifino Ana I.
Published: March 2006

This work analyzes the effect of chronic ethanol feeding on the 24-hour variation of mitogenic responses and lymphocyte subset populations in thymus and spleen. Animals were maintained under a 12:12-hour light/dark photoperiod and they received a liquid diet for 4 weeks, starting on day 35 of life. The ethanol-fed group received a similar diet to controls except that maltose was isocalorically replaced by ethanol. Ethanol replacement provided 36% of the total caloric content of the diet. Rats were killed at 6 time intervals around the clock, beginning at Zeitgeber time (ZT) 1 (ZT 0 = lights on). Under ethanol intake the splenic and thymic weight decreased. In addition, mean values of the thymic, but not of the splenic T cell number decreased, and mean values of the thymic and splenic CD8+ and CD4+CD8+ number increased. Consequently, the thymic T/B ratio and the thymic and splenic CD4+/CD8+ ratio decreased in ethanol-fed rats. At the same time there was a significant increase in the response of the thymic cells to LPS. The ethanol diet modified the 24-hour rhythmicity of thymic and splenic T, B and CD4+CD8+ cells, thymic CD4+ and splenic CD8+ cells, thymic and splenic T/B and CD4+/CD8+ ratios, as well as of mitogenic responses in both tissues. Chronic ethanol administration presumably affects the endogenous clock that modulates the circadian variation of immune responsiveness in growing rats.
Brain Maturation in Conduct Disorder versus Borderline Personality Disorder
Authors: Ceballos Natalie A. , Houston Rebecca J. , Hesselbrock Victor M. , Bauer Lance O.
Published: March 2006

Conduct disorder (CD) and borderline personality disorder (BPD) have been associated with abnormalities in brain function. The present study assessed whether adolescents with significant symptoms of CD and BPD display abnormal brain maturation. Participants recruited from the community were categorized as CD only, BPD only, CD plus BPD, or controls with neither CD nor BPD. Brain maturation was estimated by the amplitude difference in the P300 event-related brain potential between participants < versus ≧17 years old. With increasing age, controls and BPD only participants exhibited a P300 amplitude decline. This pattern was not evident in the CD only and CD plus BPD groups. The different brain maturation patterns seen in adolescents with CD versus BPD symptoms may contribute to differences in age-of-onset, clinical course, and resistance to treatment.
Atypical Antipsychotic Usage-Related Higher Serum Leptin Levels and Disabled Lipid Profiles in Euthymic Bipolar Patients
Authors: Gergerlioglu H. Serdar , Savas Haluk A. , Celik Ahmet , Savas Esen , Yumru Mehmet , Tarakcioglu Mehmet , Gergerlioglu Nursadan , Atmaca Murad
Published: March 2006

Atypical antipsychotics (AA)-induced weight gain is associated with increased leptin levels. AA have been increasingly used in the treatment of bipolar disorders. This cross-sectional study aimed to evaluate the association between serum leptin and lipid profiles considering the drug treatments in euthymic bipolar outpatients. Leptin and lipid profiles were compared, and no differences were noted in leptin, cholesterol, and low-density lipoprotein levels among the patients and controls. Glucose, very-low-density lipoprotein, and triglyceride levels in patients were higher than in controls, while high-density lipoprotein levels were low. Patients were divided into three groups according to their type of drug usage: AA users, AA + mood stabilizer users, and mood stabilizer users. Each group of patients was compared with a healthy control group for mentioned biochemical parameters. Lipid profiles were disordered by using both AA and mood stabilizers, but higher leptin levels are associated with AA usage. However, leptin does not seem to be responsible for dyslipidemia caused by AA or mood stabilizers in euthymic bipolar patients.
Mechanism of Vasopressin-Induced Contraction of Renal Medullary Interstitial Cells
Authors: Hughes Alisa K. , Kohan Donald E.
Published: March 2006

Background/Aims: Previous studies have identified a contractile function for renomedullary interstitial cells (RMIC). Such studies focused on the mechanism of endothelin-1-induced RMIC contraction; however, vasopressin (AVP) was also noted to contract RMIC. Since AVP-induced RMIC contraction may be relevant to the medullary effects of AVP on urinary concentration, these initial observations have been extended to examination of the mechanism of AVP-induced RMIC contraction. Methods: Cultured rat RMIC were exposed to AVP and other agents, and examined using video microscopy. Results: AVP caused a slowly developing and dose-dependent reduction in RMIC surface area. AVP-induced RMIC contraction was abolished by blockade of V1, but not V2, receptors. Nifedipine and nickel reduced AVP-stimulated RMIC contraction, indicating that this effect is dependent upon dihydropyridine-sensitive calcium channels. H7, a protein kinase C inhibitor, completely abrogated AVP action, while the nitric oxide synthase inhibitor, NMMA, had no effect. Indomethacin enhanced AVP-induced RMIC contraction, and addition of PGE2 together with indomethacin reduced AVP action. Conclusion: These data indicate that AVP potently contracts RMIC via V1 receptor stimulation of PKC and intracellular calcium accumulation, and that AVP-stimulated prostaglandin production downregulates the contractile effect of AVP on RMIC. AVP modulation of RMIC contraction may be involved in the regulation of urinary concentration.
Proteomic Analysis of Rat Plasma by SELDI-TOF-MS under the Condition of Prevention of Progressive Adriamycin Nephropathy Using Oral Adsorbent AST-120
Authors: Ishikawa Isao , Hayama Tomoyuki , Yoshida Sachiko , Asaka Mitsuhiro , Tomosugi Naohisa , Watanabe Masataka , Yamato Hideyuki , Sugano Mikio
Published: March 2006

Aims: To determine changes in relative peak intensities of mass-to-charge ratio (m/z) between 2,000 and 15,000, which are difficult to evaluate by 2-dimensional gel electrophoresis, SELDI-TOF-MS (surface-enhanced laser desorption/ionization time of flight-mass spectrometry) proteomic changes in rat models of adriamycin nephropathy with or without AST-120 were investigated. Methods: A normal group (n = 5), an adriamycin nephropathy group (n = 9), and an adriamycin nephropathy + AST-120 group (4 g/head/day) (n = 9) were established in SD rats. Anion exchange chips, Q10, washed by 50 mM Tris-HCl pH 8 as a ProteinChip and sinapinic acid were used. The mass range between 2,000 and 15,000 Da was measured. Twenty to 34 weeks after adriamycin 3 mg/kg injection, the adriamycin nephropathy + AST-120 group (plasma creatinine value: 2.1 ± 0.8 mg/dl) clearly demonstrated slight renal dysfunction compared with that in the adriamycin nephropathy group (5.4 ± 2.0 mg/dl). Results: The relative intensities in the adriamycin nephropathy group were significantly higher in 7 peaks (such as 8,640, and 8,822 Da) and lower in 8 peaks (such as 4,188, and 8,358 Da) than those in the normal group. The relationship between the relative intensity of peaks and the plasma creatinine value demonstrated a positive correlation in 11 peaks (such as 8,640, and 8,822 Da), and a negative correlation in 6 peaks (such as 4,188 and 8,358 Da). Although the relative intensities of peaks in the adriamycin nephropathy + AST-120 group were between that of the adriamycin nephropathy group and that of the normal group, the relative intensities of 4 peaks (such as 3,664 and 5,179 Da) in the adriamycin nephropathy + AST-120 group demonstrated higher values than in the two other groups. The m/z 3,664 peak was purified and identified as a C-terminal fragment of apolipoprotein C-III. Conclusion: Low-molecular proteins and peptides in plasma in this chronic renal failure model showed not only increases but also decreases in some peaks. The relative intensities in some peaks increased in the adriamycin nephropathy + AST-120 group more than in the two other groups. One of these peaks was identified as the apolipoprotein C-III fragment. The relationship between these changes and the prevention of progression of chronic renal failure by AST-120 remains to be established.
Surgical Therapy Attenuates Abdominal and Extra-Abdominal Inflammation in Experimental Peritonitis
Authors: van Till J.W.O. , Lamme B. , van Esch T.J.H. , van der Poll T. , van Gulik T.M. , Boermeester M.A.
Published: March 2006

Background: This study examines the influence of surgical management (elimination of the infectious focus and abdominal lavage) on survival and the inflammatory response in the various compartments of the body: local (abdomen), systemic (blood) and distant organ (lungs). Materials and Methods:Peritonitis was established in mice by cecal ligation and puncture (CLP). After 24 h, a group was made in which the infected cecum was resected and the abdominal cavity was lavaged (RES), and another group that received no surgical resection (NoRES). Survival was examined over a period of 96 h. Mice were sacrificed at 24 (sham and CLP), 48 and 72 h after CLP to measure inflammatory parameters. Results: Survival was significantly lower is NoRES compared to sham and RES (p = 0.006, p = 0.014, respectively). Intraperitoneal parameters were improved in the RES group compared to sham but results were not significantly different between groups. In plasma, levels of interleukin-6 (IL-6) were decreased in RES (p = 0.048). Accordingly, anti-inflammatory IL-10 in plasma was increased in this group (p = 0.031). In the lung, keratinocyte-derived chemokine (KC) and myeloperoxidase (MPO) was reduced indicating decreased granulocytes accumulation in the lung in the RES group (p = 0.012 and p = 0.004, respectively). Conclusions:In experimental secondary peritonitis surgical management improves survival and attenuates the inflammatory response predominantly in the extra-abdominal compartments. This illustrates the importance of surgery in prevention of multiple organ failure and denotes the compartmentalized character of the inflammatory response. This polymicrobial model with implicated surgical intervention reflects the clinical situation and may be more appropriate to test therapeutic interventions than a model involving only CLP.
Paraneoplastic Rhombencephalitis and Brachial Plexopathy in Two Cases of Amphiphysin Auto-Immunity
Authors: Coppens T. , van den Bergh P. , Duprez T.J. , Jeanjean A. , De Ridder F. , Sindic C.J.M.
Published: March 2006

Amphiphysin, a synaptic vesicle protein, is an auto-immune target in rare cases of paraneoplastic neurological disorders. We report two additional cases with distinct neurological syndromes and paraneoplastic anti-amphiphysin antibodies. The first patient, a 59-year-old man, presented with cerebellar and cranial nerve dysfunction and small cell lung carcinoma. The second, a 77-year- old woman, presented with left brachial plexopathy followed by sensorimotor neuropathy and breast carcinoma.
Effect of Atorvastatin Treatment on Isoproterenol-Induced Myocardial Infarction in Rats
Authors: Trivedi Chitrang J. , Balaraman R. , Majithiya Jayesh B. , Bothara Sunil B.
Published: March 2006

In the present study, chronic treatment of atorvastatin was evaluated on isoproterenol-induced myocardial infarction. Male Sprague-Dawley rats (200 ± 25 g) were randomized into the following four groups: (1) control group, (2) isoproterenol-treated group, (3) atorvastatin-treated group, and (4) isoproterenol- and atorvastatin-treated group. Various serum and tissue parameters as well as histopathological studies were carried out in all groups. Isoproterenol administration produced severe myocardial damage and oxidative stress in rats. Atorvastatin treatment reduced myocardial infarction which has been reflected by improvement in serum parameters, ATPase activities and histopathological lesions. However, it could not reduce oxidative stress and hypertrophy induced by isoproterenol. Hence, it can be concluded that atorvastatin may protect myocardial infarction induced by isoproterenol independent of its antioxidant properties.
Environment- and Age-Dependent Plasticity of Synaptic Complexes in the Mushroom Bodies of Honeybee Queens
Authors: Groh Claudia , Ahrens Dirk , Rössler Wolfgang
Published: March 2006

Diversity in behavior plays a crucial role for the division of labor in insect societies. Social insects such as honeybees provide excellent model systems to investigate neuronal principles underlying behavioral plasticity. The two female castes, queens and workers, differ substantially in anatomy, physiology, aging and behavior. The different phenotypes are induced by environmental factors rather than genetic differences. Here we investigated environment- and age-dependent effects on the synaptic organization within higher order neuropils of the honeybee brain. Synaptic complexes (microglomeruli) in sensory-input regions of the mushroom bodies, prominent higher sensory integration centers, were analyzed quantitatively using fluorescent markers and confocal microscopy. Pre- and postsynaptic compartments of individual microglomeruli were labeled by anti-synapsin immunolabeling and f-actin detection with phalloidin in dendritic spines of mushroom-body intrinsic neurons. The results demonstrate that in queens the numbers of microglomeruli in the olfactory and visual input regions of the mushroom-body calyx are significantly lower than in workers. In queens raised in incubators, microglomeruli were affected by differences in pupal rearing temperature within the range of naturally occurring temperatures (32–36°C). The highest numbers of microglomeruli developed at a lower temperature compared to workers (33.5 vs. 34.5°C). We found a striking adult plasticity of microglomeruli numbers throughout the extended life-span of queens. Whereas microglomeruli in the olfactory lip increased with age (∼55%), microglomeruli in the visual collar significantly decreased (∼35%). We propose that developmental and adult plasticity of the synaptic circuitry in the mushroom-body calyx might underlie caste- and age-specific adaptations in behavior.
Cell Birth and Survival following Seasonal Periods of Cell Proliferation in the Chemosensory Epithelia of Red-Backed Salamanders, Plethodon cinereus
Authors: Dawley Ellen M. , Nelsen Meaghan , Lopata Adrianne , Schwartz Jessica , Bierly Alison
Published: March 2006

In addition to the continuous low levels of neurogenesis typical of adult vertebrates to replace damaged chemoreceptor cells, red-backed salamanders (Plethodon cinereus) experience an up-regulation of chemoreceptor epithelial cell proliferation on a seasonal basis. Significantly more cell division occurs in late spring than at any other time of the year, and we investigated the fate and life span of these newly generated cells. We used 5-bromo-2′-deoxyuridine (BrdU) immunocytochemical cell birth dating to examine cell proliferation and cell migration in the main olfactory and vomeronasal epithelia of red-backed salamanders collected in late spring who were allowed to survive for one hour or three, four, 25, 28, 42, 49 and 100 days post-injection. We examined new neuron growth in the vomeronasal and olfactory epithelia using antibodies against Growth Associated Protein-43 (GAP-43), a protein whose synthesis is up-regulated during axon growth. We also tracked apoptosis within both types of chemosensory epithelia using terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL). BrdU-immunoreactive cells were located extensively throughout the vomeronasal epithelia, particularly in the area posterior to the entrance of the nasolacrimal duct, not only after three days of survival, but also all of the longer experimental survival periods as well; BrdU-ir cells within the olfactory epithelia were rarely located after longer survival periods. Salamanders collected in late spring displayed extensive GAP-43 labeling in the vomeronasal epithelia posterior to the entrance of the nasolacrimal duct, indicating a large population of young vomeronasal receptor neurons. Finally, apoptotic cells were evident in this same post-nasolacrimal-duct-area of the vomeronasal organ and in the olfactory epithelium. We suggest that vomeronasal receptor neurons born in late spring function throughout the summer and may be associated with the animals’ extensive territoriality during that period.
Effect of MMP-2 Deficiency on Atherosclerotic Lesion Formation in ApoE-Deficient Mice
Authors: Kuzuya Masafumi , Nakamura Kae , Sasaki Takeshi , Wu Cheng Xian , Itohara Shigeyoshi , Iguchi Akihisa
Published: March 2006

Objective—

Although it has been reported that matrix metalloproteinase (MMP)-2 is a major proteinase in atherosclerotic plaque lesions, there is no direct evidence of the role of MMP-2 in atherosclerotic lesion formation. In the present study we determined the role of MMP-2 in atherosclerosis plaque development using apolipoprotein E-deficient (apoE
−/−
) mice.

Methods and Results—

To generate MMP-2–deficient, apoE-deficient mice (MMP-2
−/−
:apoE
−/−
), MMP-2
−/−
mice were crossed with apoE
−/−
mice. After 8 weeks of feeding with a lipid-rich diet, morphological and biochemical studies of the aortic sinus and arch were conducted. A significant reduction of the atherosclerotic plaque in the aortic sinus and arch with the decrease in smooth muscle cell-positive area was observed in MMP-2
−/−
:apoE
−/−
mice compared with that of MMP-2
+/+
:apoE
−/−
mice. Macrophage- and collagen-positive areas were less in aortic sinus but not in aortic arch in MMP-2
−/−
:apoE
−/−
mice. There was no difference of MMP-9 mRNA expression in the plaque lesion between the 2 genotypes. A much lower level of mRNA expression of TIMP-1 and TIMP-2 was detected in the atherosclerotic plaque lesions of MMP-2
−/−
:apoE
−/−
mice than in those of MMP-2
+/+
:apoE
−/−
mice.

Conclusions—

MMP-2 contributes to the development of atherosclerosis in apoE
−/−
mice.
The Multiple Languages of Endothelial Cell-to-Cell Communication
Authors: Liebner Stefan , Cavallaro Ugo , Dejana Elisabetta
Published: March 2006

Intercellular adhesion plays a key role during development and maintenance of tissue homeostasis. Within the vascular system, cell–cell adhesion is particularly important for the correct formation, networking, and remodeling of vessels. Although in vascular endothelial cells adhesive junctions account for the integrity of the vessel wall, they are not to be considered as static molecular structures that function as intercellular glue. This becomes evident during the remodeling of the endothelium in various physiological and pathological processes, requiring highly dynamic vascular adhesion complexes. Moreover, it has recently become evident that, besides their structural functions, adhesion molecules involved in endothelial cell–cell interaction play an important role in inducing and integrating intracellular signals that, in turn, impact on several aspects of vascular cell physiology. In this review, we describe these recent findings focusing on junctional proteins at adherens and tight junctions. The role of this adhesion molecule-mediated signaling is discussed in the context of developmental and pathological angiogenesis.
LXR-Induced Redistribution of ABCG1 to Plasma Membrane in Macrophages Enhances Cholesterol Mass Efflux to HDL
Authors: Wang Nan , Ranalletta Mollie , Matsuura Fumihiko , Peng Felix , Tall Alan R.
Published: March 2006

Objectives—

This study examines the ABCG1-mediated cholesterol efflux and intracellular cholesterol transport by studying the ABCG1 localization and function in macrophages.

Methods and Results—

HEK 293 cell overexpressing ABCG1, RNA interference, or macrophages from ABCG1 or ABCG4 knockout mice were used. ABCG1 but not ABCG4 had a major role in the increased cholesterol mass efflux produced by treatment of macrophages with LXR activators. In 293 cells, ABCG1 was found in the plasma membrane, Golgi, and recycling endosomes. In contrast, in basal macrophages, ABCG1 was predominantly intracellular, and redistributed to the plasma membrane after LXR activation. LXR activation increased macrophage cholesterol efflux to high-density lipoprotein (HDL), low-density lipoprotein (LDL), and cyclodextrin in an ABCG1-dependent fashion. Suppression of ABCG1 expression increased cholesteryl ester formation and decreased SREBP2 target gene expression in macrophages, even in the absence of HDL acceptors.

Conclusions—

LXR activation induces redistribution of ABCG1 from intracellular sites to the plasma membrane and increases cholesterol mass efflux to HDL in an ABCG1-dependent fashion. ABCG1 acts in the macrophage plasma membrane to increase the availability of cholesterol to a variety of lipoprotein and nonlipoprotein acceptors while limiting the accumulation of cholesterol in the endoplasmic reticulum.
A Specific Pattern of Phosphodiesterases Controls the cAMP Signals Generated by Different G
s
-Coupled Receptors in Adult Rat Ventricular Myocytes
Authors: Rochais Francesca , Abi-Gerges Aniella , Horner Kathleen , Lefebvre Florence , Cooper Dermot M.F. , Conti Marco , Fischmeister Rodolphe , Vandecasteele Grégoire
Published: March 2006

Compartmentation of cAMP is thought to generate the specificity of G
s
-coupled receptor action in cardiac myocytes, with phosphodiesterases (PDEs) playing a major role in this process by preventing cAMP diffusion. We tested this hypothesis in adult rat ventricular myocytes by characterizing PDEs involved in the regulation of cAMP signals and L-type Ca
2+
current (
I
Ca,L
) on stimulation with β
1
-adrenergic receptors (β
1
-ARs), β
2
-ARs, glucagon receptors (Glu-Rs) and prostaglandin E
1
receptors (PGE
1
-Rs). All receptors but PGE
1
-R increased total cAMP, and inhibition of PDEs with 3-isobutyl-1-methylxanthine strongly potentiated these responses. When monitored in single cells by high-affinity cyclic nucleotide–gated (CNG) channels, stimulation of β
1
-AR and Glu-R increased cAMP, whereas β
2
-AR and PGE
1
-R had no detectable effect. Selective inhibition of PDE3 by cilostamide and PDE4 by Ro 20-1724 potentiated β
1
-AR cAMP signals, whereas Glu-R cAMP was augmented only by PD4 inhibition. PGE
1
-R and β
2
-AR generated substantial cAMP increases only when PDE3 and PDE4 were blocked. For all receptors except PGE
1
-R, the measurements of
I
Ca,L
closely matched the ones obtained with CNG channels. Indeed, PDE3 and PDE4 controlled β
1
-AR and β
2
-AR regulation of
I
Ca,L
, whereas only PDE4 controlled Glu-R regulation of
I
Ca,L
thus demonstrating that receptor–PDE coupling has functional implications downstream of cAMP. PGE
1
had no effect on
I
Ca,L
even after blockade of PDE3 or PDE4, suggesting that other mechanisms prevent cAMP produced by PGE
1
to diffuse to L-type Ca
2+
channels. These results identify specific functional coupling of individual PDE families to G
s
-coupled receptors as a major mechanism enabling cardiac cells to generate heterogeneous cAMP signals in response to different hormones.
Essential Role of Smad3 in Angiotensin II–Induced Vascular Fibrosis
Authors: Wang Wansheng , Huang Xiao R. , Canlas Ellery , Oka Kazuhiro , Truong Luan D. , Deng Chuxia , Bhowmick Neil A. , Ju Wenjun , Bottinger Erwin P. , Lan Hui Y.
Published: March 2006

Angiotensin II (Ang II) plays a pivotal role in vascular fibrosis, which leads to serious complications in hypertension and diabetes. However, the underlying signaling mechanisms are largely unclear. In hypertensive patients, we found that arteriosclerosis was associated with the activation of Smad2/3. This observation was further investigated in vitro by stimulating mouse primary aorta vascular smooth muscle cells (VSMCs) with Ang II. There were several novel findings. First, Ang II was able to activate an early Smad signaling pathway directly at 15 to 30 minutes. This was extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) dependent but transforming growth factor-β (TGF-β) independent because Ang II–induced Smad signaling was blocked by addition of ERK1/2 inhibitor and by dominant-negative (DN) ERK1/2 but not by DN-TGF-β receptor II (TβRII) or conditional deletion of TβRII. Second, Ang II was also able to activate the late Smad2/3 signaling pathway at 24 hours, which was TGF-β dependent because it was blocked by the anti–TGF-β antibody and DN-TβRII. Finally, activation of Smad3 but not Smad2 was a key and necessary mechanism of Ang II–induced vascular fibrosis because Ang II induced Smad3/4 promoter activities and collagen matrix expression was abolished in VSMCs null for Smad3 but not Smad2. Thus, we concluded that Ang II induces vascular fibrosis via both TGF-β–dependent and ERK1/2 MAPK-dependent Smad signaling pathways. Activation of Smad3 but not Smad2 is a key mechanism by which Ang II mediates arteriosclerosis.
Statins Protect Human Aortic Smooth Muscle Cells From Inorganic Phosphate-Induced Calcification by Restoring Gas6-Axl Survival Pathway
Authors: Son Bo-Kyung , Kozaki Koichi , Iijima Katsuya , Eto Masato , Kojima Taro , Ota Hidetaka , Senda Yuka , Maemura Koji , Nakano Toru , Akishita Masahiro , Ouchi Yasuyoshi
Published: March 2006

Vascular calcification is clinically important in the development of cardiovascular disease. It is reported that hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins) inhibited vascular calcification in several clinical trials. However, the mechanism is poorly understood. Recently, it has been suggested that apoptosis is one of the important processes regulating vascular smooth muscle cell (VSMC) calcification. In this study, we investigated the effect of statins on VSMC calcification by testing their effect on apoptosis, focusing in particular on regulation of the survival pathway mediated by growth arrest-specific gene 6 (Gas6), a member of the vitamin K–dependent protein family, and its receptor, Axl. In human aortic smooth muscle cells (HASMC), statins significantly inhibited inorganic phosphate (Pi)-induced calcification in a concentration-dependent manner (reduced by 49% at 0.1 μmol/L atorvastatin). The inhibitory effect of statins was mediated by preventing apoptosis, which was increased by Pi in a concentration-dependent manner, and not by inhibiting sodium-dependent phosphate cotransporter (NPC) activity, another mechanism regulating HASMC calcification. Furthermore, the antiapoptotic effect of statins was dependent on restoration of Gas6, whose expression was downregulated by Pi. Restoration of Gas6 mRNA by statins was mediated by mRNA stabilization, and not by an increase in transcriptional activity. Suppression of Gas6 using small interfering RNA and the Axl-extracellular domain abolished the preventive effect of statins on Pi-induced apoptosis and calcification. These data demonstrate that statins protected HASMC from Pi-induced calcification by inhibiting apoptosis via restoration of the Gas6-Axl pathway.
KCNQ1 Assembly and Function Is Blocked by Long-QT Syndrome Mutations That Disrupt Interaction With Calmodulin
Authors: Ghosh Smita , Nunziato Deborah A. , Pitt Geoffrey S.
Published: March 2006

Calmodulin (CaM) has been recognized as an obligate subunit for many ion channels in which its function has not been clearly established. Because channel subunits associate early during channel biosynthesis, CaM may provide a mechanism for Ca
2+
-dependent regulation of channel formation. Here we show that CaM is a constitutive component of KCNQ1 K
+
channels, the most commonly mutated long-QT syndrome (LQTS) locus. CaM not only acts as a regulator of channel gating, relieving inactivation in a Ca
2+
-dependent manner, but it also contributes to control of channel assembly. Formation of functional tetramers requires CaM interaction with the KCNQ1 C-terminus. This CaM-regulated process is essential: LQTS mutants that disrupt CaM interaction prevent functional assembly of channels in a dominant-negative manner. These findings offer a new mechanism for LQTS defects and provide a basis for understanding novel ways that intracellular Ca
2+
and CaM regulate ion channels.
Calmodulin Is Essential for Cardiac
I
KS
Channel Gating and Assembly
Authors: Shamgar Liora , Ma Lijuan , Schmitt Nicole , Haitin Yoni , Peretz Asher , Wiener Reuven , Hirsch Joel , Pongs Olaf , Attali Bernard
Published: March 2006

The slow
I
KS
K
+
channel plays a major role in repolarizing the cardiac action potential and consists of the assembly of KCNQ1 and KCNE1 subunits. Mutations in either KCNQ1 or KCNE1 genes produce the long-QT syndrome, a life-threatening ventricular arrhythmia. Here, we show that long-QT mutations located in the KCNQ1 C terminus impair calmodulin (CaM) binding, which affects both channel gating and assembly. The mutations produce a voltage-dependent macroscopic inactivation and dramatically alter channel assembly. KCNE1 forms a ternary complex with wild-type KCNQ1 and Ca
2+
-CaM that prevents inactivation, facilitates channel assembly, and mediates a Ca
2+
-sensitive increase of
I
KS-
current, with a considerable Ca
2+
-dependent left-shift of the voltage-dependence of activation. Coexpression of KCNQ1 or
I
KS
channels with a Ca
2+
-insensitive CaM mutant markedly suppresses the currents and produces a right shift in the voltage-dependence of channel activation. KCNE1 association to KCNQ1 long-QT mutants significantly improves mutant channel expression and prevents macroscopic inactivation. However, the marked right shift in channel activation and the subsequent decrease in current amplitude cannot restore normal levels of
I
KS
channel activity. Our data indicate that in healthy individuals, CaM binding to KCNQ1 is essential for correct channel folding and assembly and for conferring Ca
2+
-sensitive
I
KS
-current stimulation, which increases the cardiac repolarization reserve and hence prevents the risk of ventricular arrhythmias.
Perceptual, Social, and Behavioral Factors Associated With Delays in Seeking Medical Care in Patients With Symptoms of Acute Stroke
Authors: Mandelzweig Lori , Goldbourt Uri , Boyko Valentina , Tanne David
Published: March 2006

Background and Purpose—

Despite availability of reperfusion therapy for acute ischemic stroke, most patients remain ineligible mainly because of late hospital arrival. We hypothesized that perceptual, social, and behavioral factors affect delays in seeking help after symptom onset.

Methods—

Patients presenting with stroke symptoms were interviewed about symptom experiences, interpretations, and reactions. Odds ratios (95% CI) for risk of delay >3 hours were estimated, and variables associated with increased risk and representing demographic, clinical, perceptual, social, and behavioral factors were included in an assessment of the effect of combined risk factors on delay.

Results—

Among 209 patients (mean age 61.8±12 years, 69% men) the median time interval from symptom awareness to seeking help was 2 (0.5 to 9) hours and to hospital arrival, 4.2 (1.3 to 14.5) hours. On multivariate adjustment, perceiving symptoms as severe (odds ratio [OR]: 0.42; 0.17 to 0.95), advice from others to seek help (OR: 0.18; 0.05 to 0.63), and contacting an ambulance (OR: 0.26; 0.10 to 0.63) were associated with decreased risks of delay, whereas perceived control of symptoms (OR: 2.45; 1.08 to 5.71) increased risk of delay in seeking help. Risk of delay in hospital arrival was 3 times greater in women than in men. Increasing proportions of patients who delayed seeking help were observed with increasing numbers of combined risk factors, ranging from 17% to 94% for 0 to 1 and 6 to 7 factors, respectively.

Conclusions—

Perceptual, social, and behavioral factors contribute to delay in seeking medical care in acute ischemic stroke beyond demographic and clinical variables, and, when combined, further increase risk of delay. These findings may be important for designing programs to reduce delay.
Racial and Geographic Differences in Awareness, Treatment, and Control of Hypertension
Authors: Howard George , Prineas Ron , Moy Claudia , Cushman Mary , Kellum Martha , Temple Ella , Graham Andra , Howard Virginia
Published: March 2006

Background and Purpose—

Stroke mortality is higher in the “Stroke Belt” and among blacks in the United States. Because hypertension is the leading risk factor for stroke, hypertension management (raising awareness, increasing treatment, and improving control) may reduce these disparities.

Methods—

Hypertension awareness, treatment, and control were measured in the REasons for Geographic And Racial Differences in Stroke study, a national population-based cohort of black and white participants >45 years of age. At the time of this report, 11 701 had been enrolled. Racial differences and geographic differences (between the Stroke Belt and other regions of the United States) were described.

Results—

Black participants were more aware than whites of their hypertension (odds ratio [OR], 1.31; 95% CI, 1.07 to 1.59) and more likely to be on treatment if aware of their diagnosis (OR, 1.69; 95% CI, 1.40 to 2.05), but among those treated for hypertension, they were less likely than whites to have their blood pressure controlled (OR, 0.73; 95% CI, 0.64 to 0.83). There was no evidence of a difference between the Stroke Belt and other regions in awareness of hypertension (OR, 0.95; 95% CI, 0.79 to 1.14), but there was a trend for better treatment (OR, 1.15; 95% CI, 0.97 to 1.37) and control (OR, 1.11; 95% CI, 0.98 to 1.30) in the Stroke Belt region.

Conclusions—

These findings suggest that interventions to improve blood pressure control among blacks are promising to reduce the racial disparity in stroke mortality. The lack of substantial geographic differences in hypertension awareness and the trend toward better treatment and control in the Stroke Belt suggest that differences in hypertension management may not be a major contributor to the geographic disparity in stroke mortality.
Good Outcomes in Ischemic Stroke Patients Treated With Intravenous Thrombolysis Despite Regressing Neurological Symptoms
Authors: Baumann Christian R. , Baumgartner Ralf W. , Gandjour Joubin , von Büdingen Hans-Christian , Siegel Adrian M. , Georgiadis Dimitrios
Published: March 2006

Background and Purpose—

We evaluated the clinical course of 19 acute stroke patients with rapid early improvement of neurological deficit within the 3-hour window, treated with intravenous thrombolytics.

Results—

No patient demonstrated a neurological deterioration during hospitalization. National Institutes of Health Stroke Scale (NIHSS) scores at therapy decision and discharge were 5 (4 to 6) and 0.5 (0 to 1.5), respectively. At 3-month follow-up, 1 patient had died; in remaining patients, NIHSS was 0 (0 to 1) and modified Rankin Scale 0.5 (0 to 1; ≤1 in 15 patients).

Conclusions—

Withholding of intravenous thrombolysis because of spontaneous early regression of neurological symptoms may not be justified.
Electrical Forepaw Stimulation During Reversible Forebrain Ischemia Decreases Infarct Volume
Authors: Burnett Mark G. , Shimazu Tomokazu , Szabados Tamas , Muramatsu Hiromi , Detre John A. , Greenberg Joel H.
Published: March 2006

Background and Purpose—

Functional stimulation is accompanied by increases in regional cerebral blood flow which exceed metabolic demands under normal circumstances, but it is unknown whether functional stimulation is beneficial or detrimental in the setting of acute ischemia. The aim of this study was to determine the effect of forepaw stimulation during temporary focal ischemia on neurological and tissue outcome in a rat model of reversible focal forebrain ischemia.

Methods—

Sprague-Dawley rats were prepared for temporary occlusion of the right middle cerebral artery (MCA) using the filament model. Cerebral blood flow in the MCA territory was continuously monitored with a laser-Doppler flowmeter. Subdermal electrodes were inserted into the dorsal forepaw to stimulate either the forepaw ipsilateral or contralateral to the occlusion starting 1 minute into ischemia and continuing throughout the ischemic period. A neurological evaluation was undertaken after 24 hours of reperfusion, and animals were then euthanized and brain slices stained with 2,3,5-triphenyltetrazolium chloride. Cortical and striatal damage was measured separately.

Results—

The cortical and striatal infarct volumes were both significantly reduced in the contralateral stimulated group compared with the ipsilateral stimulated group (48% total reduction). There were no statistically significant differences in the neurobehavioral scores between the 2 groups, or in the laser-Doppler flow measurements from the MCA core.

Conclusions—

Functional stimulation of ischemic tissue may decrease tissue damage and improve outcome from stroke. Although the precise mechanism of this effect remains to be determined, functional stimulation could readily be translated to clinical practice.