bluuebunny/crossref_metadata_2025 huggingface dataset:
Exaggerated TSH Responses to TRH in Patients with Goiter and ‘Normal’ Basal TSH Levels
Authors: Evliyaoğlu Olcay , Berberoğlu Merih , Öcal Gönül , Adıyaman Pelin , Aycan Zehra
Published: February 2006

Background/Aim: The availability of sensitive thyrotropin (TSH) assays decreased the diagnostic value of thyrotropin-releasing hormone stimulation tests (TRH-ST) in subclinical hypothyroidism. In this study we aimed to evaluate the relation between basal and stimulated serum TSH levels on TRH-ST and to determine the prevalence of patients with normal basal serum TSH and exaggerated TSH responses. Methods: 179 patients (117 girls, 123 pubertal) with a median age of 12 (2.7–21.4) years who presented with goiter were enrolled and evaluated for their pubertal stage, height, thyroid autoimmunity, ultrasonography, thyroid function, and TRH-ST. Serum TSH concentrations were determined by sensitive assays. At TRH-ST, a peak serum TSH level >25 mIU/l was considered as an exaggerated response. Results: 30 (17%) patients had an exaggerated TSH response. In patients with serum TSH levels between 2 and 4.68 mIU/l (upper half the normal range), an exaggerated TSH response was observed in 19.5%. A positive correlation between basal and TRH-stimulated TSH levels was determined (r = 0.536, p < 0.01). In patients with an exaggerated TSH response, 23 had normal (discordant) and 7 had high basal TSH levels (concordant). The mean basal serum TSH level was lower in the discordant group compared to the concordant group (p < 0.01). Conclusion: Basal serum TSH levels might not be sufficient for diagnosing subclinical hypothyroidism. Stimulated TSH levels on TRH-ST are valuable, especially when serum TSH concentrations are in the upper half of the normal range.
A New Specific Gene Expression in Squamous Cell Carcinoma of the Esophagus Detected Using Representational Difference Analysis and cDNA Microarray
Authors: Kan Takatsugu , Yamasaki Seiji , Kondo Kan , Teratani Naoki , Kawabe Atsushi , Kaganoi Junichi , Meltzer Stephen J. , Imamura Masayuki , Shimada Yutaka
Published: February 2006

Objectives: To detect new specific gene expressions in squamous cell carcinoma of the esophagus. Methods: Representational difference analysis of cDNA (cDNA RDA) was applied to a human esophageal cancer cell line (KYSE170) and a human esophageal epithelial cell line (HEEC-1). Results: LAGE-1 was expressed specifically in KYSE170, but not in HEEC-1. It is also expressed in 27% of esophageal cancer cell lines (3/11) and 33% of esophageal cancer tissues (10/30), but not in other HEECs, normal esophageal epithelium, or other normal tissues except testis, ovary and kidney. The expression of LAGE-1 is strongly correlated with that of MAGE-A1 (p = 0.013, Fisher’s exact probability test). Fibronectin, cytokeratin 6B, cytokeratin 19, cyclin D2 and Ten-m2 were detected as candidates for downregulated genes. Reduced expression profiles of them were also identified using cDNA microarrays. The expression of LAGE-1 was induced by 5′-aza-2′-deoxycytidine (5Aza-dC) and trichostatin A (TSA) in esophageal cancer cell lines, which did not express LAGE-1. In HEECs, 5Aza-dC induced LAGE-1 expression, but TSA did not. Conclusions: LAGE-1 expression was detected in esophageal cancer by cDNA RDA. LAGE-1 might have the potential to be a target antigen for anti-tumoral immunotherapy in esophageal cancers because of its tumor-specific expression similar to that of MAGE-A1.
Dexamethasone Pharmacokinetics in Guinea Pig Inner Ear Perilymph
Authors: Liu Hong-Jian , Dong Ming-Min , Chi Fang-Lu
Published: February 2006

Aim: To study the dexamethasone pharmacokinetics in the inner ear perilymph of guinea pigs using high-pressure liquid chromatography. Methods: Sixty-five guinea pigs were divided into three groups. In the first group, the drug application protocol used an intra-abdominal dose of 0.5% dexamethasone 4 mg·kg–1. In the second group, an intratympanic application dose of 0.5% dexamethasone 150 µl was used. The third group was the control group. The concentrations of dexamethasone in inner ear perilymph were determined by high-pressure liquid chromatography. Results: The perilymph concentration-time curves of dexamethasone conformed to a one-compartment open model after an intra-abdominal application. The Cmax was 0.927 ± 0.008 mg·l–1, the Tmax 1.47 ± 0.04 h, the T1/2K 2.92 ± 0.056 h, the AUC 5.533 ± 0.05 mg·h·l–1, the T1/2Ka 0.47 ± 0.024 h. After an intratympanic application, the perilymph concentration-time curves of dexamethasone also conformed to a one-compartment open model. The Cmax was 0.201 ± 0.006 mg·l–1, the Tmax 0.117 ± 0.06 h, the AUC 0.868 ± 0.004 mg·h·l–1, the T1/2K 2.918 ± 0.089 h, the T1/2Ka 0.161 ± 0.009 h. Compared to the intra-abdominal application, the intratympanic application resulted in similar levels of inner ear perilymph drug concentrations in 30 min. Conclusion: Dexamethasone can penetrate the blood-labyrinthine barrier after intra-abdominal application. Dexamethasone can enter into perilymph after intratympanic application. Under the condition of the study, the intratympanic application resulted in a similar level of inner ear perilymph drug concentrations compared to the intra-abdominal application in 30 min.
Association of the –1438G/A Polymorphism of the 5-HT2A Receptor Gene with Obstructive Sleep Apnea Syndrome
Authors: Bayazit Yildirim A. , Yılmaz Metin , Ciftci Tansu , Erdal Emin , Kokturk Oguz , Gökdogan Tuba , Kemaloglu Yusuf K. , Inal Erdogan
Published: February 2006

Objective: Serotonergic neurons innervating motoneurons increase their firing rates in response to respiratory challenges, and long-term facilitation of respiratory activity in response to hypoxia is serotonin (5-HT) dependent. Polymorphism of the genes which code for 5-HT receptors may affect functions of the serotonergic system, and may be associated with obstructive sleep apnea syndrome (OSAS). The objective in this study was to assess the significance of T102C and –1438G/A polymorphisms of the 5-HT2A receptor gene in OSAS. Methods: Fifty-five patients with OSAS and 102 healthy volun teers were included for genetic analyses of T102C and –1438G/A polymorphisms of the 5-HT2A receptor gene. Results: For the T102C polymorphism, there was no significant difference between the patients and controls and both genders (p > 0.05). For the –1438G/A polymorphism, the A/A and G/A genotypes were overrepresented in the patients and controls, respectively (p = 0.045). In the control group, the genotypes of both genders were not significantly different (p > 0.05). In the patients, the A/A and G/A genotypes were overrepresented in males and females, respectively (p = 0.035). Concerning males, the A/A genotype was overrepresented in patients (p = 0.007). Conclusion: Serotonergic mechanisms appear to be related to OSAS. The T102C polymorphism of the 5-HT2A receptor gene is not associated with OSAS. However, the –1438G/A polymorphism is associated with OSAS occurrence, especially in male patients. This polymorphism may also be associated with different OSAS incidences of both genders.
Spasticity and Its Association with Functioning and Health-Related Quality of Life 18 Months after Stroke
Authors: Welmer Anna-Karin , von Arbin Magnus , Widén Holmqvist Lotta , Sommerfeld Disa K.
Published: February 2006

Background: There is no consensus concerning the presence of spasticity or the relationship between spasticity and functioning and spasticity and health-related quality of life (HRQL) in the stable phase after stroke. Objective: The aim of the present study was to describe, 18 months after stroke, the frequency of spasticity and its association with functioning and HRQL. Methods: In a cohort of 66 consecutive patients with first-ever stroke, studied prospectively, the following parameters were assessed 18 months after stroke: spasticity, by the Modified Ashworth Scale (0–4 points with 1+ as the modification), muscle stiffness, by self-report, abnormal tendon reflexes, by physical examination, motor performance, by the Lindmark Motor Assessment Scale, mobility, by the Rivermead Mobility Index, activities of daily living, by the Barthel Index, and HRQL, by the Swedish Short Form 36 Health Survey Questionnaire (SF-36). Results: Of 66 patients studied, 38 were hemiparetic; of these, 13 displayed spasticity, 12 had increased tendon reflexes, and 7 reported muscle stiffness 18 months after stroke. Weak (r < 0.5) to moderate (r = 0.5–0.75) correlations were seen between spasticity and functioning scores. Correlations between spasticity and HRQL were generally weak (r < 0.5). Hemiparetic patients without spasticity had significantly better functioning scores and significantly better HRQL on 1 of the 8 SF-36 health scales (physical functioning) than patients with spasticity. Conclusions: Few patients displayed spasticity 18 months after stroke. Spasticity might contribute to impairment of movement function and to limitation of activity, but seems to have a less pronounced effect on HRQL.
Decreased Frequencies of ABCA1 Polymorphisms R219K and V771M in Hungarian Patients with Cerebrovascular and Cardiovascular Diseases
Authors: Andrikovics Hajnalka , Pongrácz Endre , Kalina Ðkos , Szilvási Anikó , Aslanidis Charalampos , Schmitz Gerd , Tordai Attila
Published: February 2006

Background and Purpose: Genetic polymorphisms in ABC transporter A1 (ABCA1) may alter the regulation of plasma high-density lipoprotein (HDL), promoting or protecting from vascular diseases. Methods: We investigated 244 unrelated, consecutively enrolled patients with ischemic stroke, 150 patients with coronary heart disease (CHD) and 193 blood donors for allele frequencies (AFs) of three common ABCA1 polymorphisms (R219K, V771M and I883M). Results: Compared to controls (30.8 ± 4.7 and 4.9 ± 2.2%, respectively), decreased AFs were found in both patient groups for R219K and V771M (28.7 ± 4.1 and 3.1 ± 1.6% in stroke, and 25.7 ± 5.0%; 1.3 ± 1.3% in CHD patients, respectively). In a subset of stroke patients younger than 50, both variants occurred in significantly lower frequencies (22.4 ± 5.5 and 1.8 ± 1.7%, respectively). Similarly, among CHD patients younger than 60, AFs of R219K and V771M (22.6 ± 7.5 and 0 ± 1.6%, respectively) were decreased. V771M was almost exclusively (35/36) found in individuals carrying the R219K allele. Conclusions: Our data confirm earlier observations that ABCA1 R219K and V771M polymorphisms may be associated with a protective role against CHD and extend those to another important pathologic condition, namely stroke.
Endoscopic Surgery with Powered Instrumentation for Isolated Sphenoid Sinus Disease
Authors: Yu Hongmeng , Li Huawei , Chi Fanglu , Dai Chunfu , Zhang Chonghua , Wang Zhengmin
Published: February 2006

Objective: Isolated sphenoid sinus disease (ISSD) is a relatively uncommon disease. In this study, we investigate the diagnosis and pathology of ISSD and compare endoscopic treatment with powered instrumentation with conventional surgical instruments for ISSD. Methods: Ninety-six out of 2,263 patients who underwent endoscopic surgery were diagnosed with ISSD by nasal endoscopy and computed tomography scan. Ninety-six cases of confirmed ISSD were treated by endoscopic sphenoidotomy, of which 44 cases were operated using powered instrumentation and 52 using conventional instruments. All patients were followed up for a period ranging from 18 to 54 months (mean 26 months) and the surgical outcomes were retrospectively reviewed. Results: The pathological findings of these patients included sphenoid sinusitis, fungal disease, sphenoid cyst, inverted papilloma, malignant tumor, sphenoid polyp, and foreign body. The most common initial symptom was headache, followed by visual changes and nasal symptoms. After endoscopic surgery, drainage of the sphenoid was accomplished in 87 of the 96 patients (91%). Of all patients, 9.4% (9/96) had recurrent incidence, 22% (21/96) sphenoid ostium synechia, and 51% (49/96) partial middle turbinectomy. Comparing the surgical outcomes between two operative approaches, recurrent incidence, sphenoid ostium synechia, and partial middle turbinectomy were significantly lower in the powered instrumentation group (2, 7, and 14%) than in the conventional instrument group (15, 35, and 83%;p < 0.05). No serious complication occurred in either group. Conclusions: Powered instrumentation is more effective than conventional instruments in the treatment of ISSD and provides a minimally invasive surgical approach to the sphenoid sinus.
Acute Alterations in Biochemistry, Morphology and Contractility of Rat Isolated Urinary Bladder via Increased Intra-Abdominal Pressure
Authors: Unsal M.A. , Imamoğlu Mustafa , Cay Ali , Kadioglu Mine , Aydin Sevim , Ulku Cunay , Kesim Murat , Alver Ahmet , Bozkaya Hasan
Published: February 2006

Objective: To determine the acute effects of increased intra-abdominal pressure (IAP) on the biochemistry, morphology and contractility of the rat isolated urinary bladder using an experimental laparoscopy model. Methods: We divided 24 adult female Sprague–Dawley rats into three groups. The control group (group I) was not subjected to increased IAP. In groups II and III, IAPs of 10 and 20 mm Hg, respectively, were established by carbon dioxide pneumoperitoneum for 60 min. Thirty minutes after desufflation, the rat urinary bladder dome was removed for in vitro pharmacological investigation, measurement of malondialdehyde (MDA) levels and histopathological examination. Statistical comparisons between groups were performed. Results: Tissue MDA levels in groups II and III were significantly higher than in the control group. In group II, only the lamina propria was significantly damaged. However, the epithelium, lamina propria, and serosa were significantly damaged in group III. Acetylcholine potentiated contractions in both IAP groups. Increased responses to electrical field stimulation in the IAP groups were significant only in group II. Conclusions: In this experimental model, 10 and 20 mm Hg of IAP induced by pneumoperitoneum increased MDA levels and caused important changes in the morphology and contractile response of the urinary bladder.
High Prevalence of Streptococcus pneumoniae with Mutations in pbp1a, pbp2x, and pbp2b Genes of Penicillin-Binding Proteins in the Nasopharynx in Children in Japan
Authors: Hotomi Muneki , Billal Dewan S. , Shimada Jun , Suzumoto Masaki , Yamauchi Kazuma , Fujihara Keiji , Yamanaka Noboru
Published: February 2006

Objective: To evaluate the resistances of Streptococcus pneumoniae to β-lactams developed by stepwise alterations in high-molecular-weight penicillin-binding proteins (PBPs) with a reduced binding affinity of β-lactams. Among the numerous mutations in pbp genes that alter the affinity for β-lactams, the decreased affinity of PBP1A, 2X and 2B is especially important in the development of resistances to β-lactams. Study Design: Retrospective review. Methods:In this study, we investigated the mutations in pbp1a, pbp2x, and pbp2b genes evaluated by polymerase chain reaction (PCR) in 866 pneumococcal isolates collected from the nasopharynx of Japanese children with acute otitis media. Results: 210 strains (24.3%) exhibited no mutations in the three pbp genes. 333 strains (38.5%) had mutations in the three pbp genes, 78 (9.0%) in two pbp genes, whereas 245 (28.3%) displayed mutations in only one pbp gene. Among the 656 strains with mutations in pbp genes, 620 (94.5%) strains had mutations in pbp2x. The annual prevalence of antimicrobial-resistant S. pneumoniae showed a gradual increase in strains with mutations in the three pbp genes and a parallel decrease in strains without mutations. Conclusions: PCR-based genotyping can characterize the antimicrobial resistances in pneumococci along with minimal inhibitory concentrations (MICs). Physicians should pay attention to the recent increase in antimicrobial-resistant S. pneumoniae when treating pediatric acute otitis media.
McCune-Albright Syndrome in a Boy May Present with a Monolateral Macroorchidism as an Early and Isolated Clinical Manifestation
Authors: Arrigo Teresa , Pirazzoli Piero , De Sanctis Luisa , Leone Ornella , Wasniewska Malgorzata , Messina Maria Francesca , De Luca Filippo
Published: February 2006

Background: Testis enlargement in McCune-Albright syndrome (MAS) is generally bilateral and associated with clinical and biochemical manifestations of sexual precocity. Case Report: We describe for the first time an unreported clinical expression of MAS in a 4.6-year-old boy presenting with monolateral testis enlargement and no signs of sexual precocity or other clinical manifestations of MAS at the time of presenting with macroorchidism. Both testosterone and LHRH-stimulated gonadotropin levels were in the prepubertal range. Serum inhibin B was increased to a pubertal level indicating Sertoli cell activation. The histological and immunocytochemical evaluation of the enlarged testis revealed Sertoli cell hyperplasia with no mature Leydig cells. Mutation R201C of GNAS1 gene, classically responsible for MAS, was identified in DNA samples from the right testis biopsy and leukocytes. Conclusions: (a) MAS should be taken into consideration in the clinicopathological approach to a boy with monolateral macroorchidism; (b) testicular enlargement may be only the presenting clinical manifestation of MAS and is not necessarily linked to manifestations of peripheral precocious puberty; (c) testicular autonomous hyperfunction in MAS may be restricted to Sertoli cells, as also demonstrated previously by others.
New Aspects of Copper and Iron Metabolism in the Myelodysplastic Syndromes
Authors: Várkonyi Judit , Szabó Terézia , Sebestyén Piroska , Tordai Attila , Andrikovics Hajnalka , Kollai Géza , Karádi István
Published: February 2006

Background: Myelodysplastic syndrome (MDS) is an iron overload condition. Copper deficiency itself might induce dysplastic changes and iron overload. The relationship between the iron and copper metabolism is analyzed in MDS patients. Methods: Copper, iron and ceruloplasmin levels were established, and transferrin saturation determination and HFE mutation analysis were performed in 32 MDS patients. Results: Eleven of 32 MDS patients were copper deficient. A decreased copper level occurred together with a significantly elevated iron level and transferrin saturation and in 45% HFE gene mutation. In the normal copper group, twice as many patients had a decreased rather than an elevated iron content and carried the wild-type HFE gene rather than the mutant. Conclusions: Copper deficiency is a frequent finding in MDS. It is desirable to include copper level determination in the initial workup of MDS.
Comparison of Uvulopalatopharyngoplasty, Laser-Assisted Uvulopalatoplasty and Cautery-Assisted Uvulopalatoplasty in the Treatment of Primary Snoring
Authors: Cincik Hakan , Cekin Engin , Cetin Bilal , Gungor Atila , Poyrazoglu Ethem
Published: February 2006

Objective: Our aim was to compare the postoperative pain and surgical results of uvulopalatopharyngoplasty (UPPP), laser-assisted uvulopalatoplasty (LAUP), and cautery-assisted uvulopalatoplasty (CAUP) procedures in the treatment of primary snoring. Methods: 54 patients were stratified according to a modified Friedman staging system (MFSS) for sleep-disordered breathing. Tonsil size (1, 2, 3) and palatal position scale (grade 1–2) and body mass index <30 according to the MFSS were included for standardization. Three workgroups consisting of 18 patients each were formed and UPPP, LAUP and CAUP procedures were performed. The success of the surgical procedures was evaluated by applying the Epworth Sleepiness Scale to the patients, and the patients’ bed partners were asked to evaluate the snoring level preoperative and 45 days after the operation to determine any improvement in snoring complaints. Patients were followed for postoperative pain, secondary infection, bleeding, permanent velopharyngeal insufficiency and nasopharyngeal stenosis. Results: Snoring was relieved in 83.3% of UPPP and CAUP groups and in 88.8% of LAUP 45 days after operation. The mean pain duration was 5.71 days for the UPPP patients, 6.28 days for the LAUP patients and, 4.12 days for the CAUP patients. The mean pain score was 2.1 for the UPPP patients, 2.38 for the LAUP patients, and 1.6 for the CAUP patients. Only 1 patient was hospitalized due to pain in the LAUP group. Conclusion: The effectiveness of UPPP, LAUP and CAUP procedures were found to be similar (more than 83%). Postoperative pain was mostly seen in LAUP and UPPP cases. The CAUP procedure was easy and the least painful.
Effect of Modified C-Reactive Protein on Complement Activation
Authors: Ji Shang-Rong , Wu Yi , Potempa Lawrence A. , Liang Yu-Heng , Zhao Jing
Published: February 2006

Objective—The capacity of human C-reactive protein (CRP) to activate/regulate complement may be an important characteristic that links CRP and inflammation with atherosclerosis. Recent advances suggest that in addition to classical pentameric CRP, a conformationally distinct isoform of CRP, termed modified or monomeric CRP (mCRP), may also play an active role in atherosclerosis. Although the complement activation behavior of CRP has been well established, the capacity of mCRP to interact with and activate the complement cascade is unknown.

Methods and Results—mCRP bound avidly to purified C1q, and this binding occurred primarily through collagen-like region of C1q. Fluid phase mCRP inhibited the activation of complement cascade via engaging C1q from binding with other complement activators. In contrast, when immobilized or bound to oxidized or enzymatically modified low-density lipoprotein, mCRP could activate classical complement pathway. Low-level generation of sC5b-9 indicated that the activation largely bypassed the terminal sequence of complement, which appears to involve recruitment of Factor H.

Conclusions—These results indicate that mCRP can both inhibit and activate the classical complement pathway by binding C1q, depending on whether it is in fluid phase or surface-bound state.
Urokinase Plasminogen Activator Stimulates Vascular Smooth Muscle Cell Proliferation Via Redox-Dependent Pathways
Authors: Menshikov Mikhail , Plekhanova Olga , Cai Hua , Chalupsky Karel , Parfyonova Yelena , Bashtrikov Pavel , Tkachuk Vsevolod , Berk Bradford C.
Published: February 2006

Objective—We showed previously that increased urokinase plasminogen activator (uPA) expression contributes to vascular smooth muscle cell (VSMC) proliferation and neointima formation after injury. Proliferation of cultured rat aortic VSMCs induced by uPA was inhibited by the antioxidant ebselen. Because increases in VSMC reactive oxygen species (ROS) contribute to VSMC proliferation, we hypothesized that uPA increases ROS generation by regulating expression or activity of cellular oxidases.

Methods and Results—uPA stimulated ROS production to levels equivalent to angiotensin II as measured by electron spin resonance and fluorescent redox indicators (dichlorofluorescein diacetate, lucigenin, and hydroethidine). The increase in ROS was biphasic, with the first peak at 30 minutes and the second peak at 4 hours. uPA increased expression of the NAD(P)H oxidases Nox1 and Nox4 as measured by RT-PCR and Western blot analysis. Knockdown of Nox1 and Nox4 expression with small interfering RNA showed that both isoforms (Nox1>Nox4) contributed significantly to uPA-stimulated ROS production and VSMC proliferation. Transfection of VSMCs with uPA cDNA to increase endogenous uPA expression enhanced ROS production dramatically, suggesting that autocrine uPA production may be an important mechanism for uPA-mediated VSMC events.

Conclusion—These data show that uPA is an autocrine VSMC growth factor that increases ROS generated by both Nox1 and Nox4 oxidases.
Peroxisome Proliferator-Activated Receptor-α,γ-Agonist Improves Insulin Sensitivity and Prevents Loss of Left Ventricular Function in Obese Dyslipidemic Mice
Authors: Verreth Wim , Ganame Javier , Mertens Ann , Bernar Hilde , Herregods Marie-Christine , Holvoet Paul
Published: February 2006

Objective—

We investigated the effect of a dual peroxisome proliferator-activated receptor (PPAR)α,γ-agonist on atherosclerosis and cardiac function in mice with combined leptin and low-density lipoprotein receptor deficiency (DKO). In these mice, obesity, diabetes, and hyperlipidemia are associated with accelerated atherosclerosis and loss of cardiac function.

Methods and Results—

We treated 12-week-old DKO mice with the PPARα,γ-agonist (S)-3-(4-(2-carbazol-9-yl-ethoxy) phenyl-2-ethoxy-propionic-acid) for 12 weeks. The agonist lowered free fatty acids with 42% and increased insulin sensitivity with 76%. It had no effect on plasma cholesterol and triglycerides. RT-PCR analysis showed that the agonist increased the expression of fatty acid transport protein-4, fatty acid binding protein-4, glucose transporter-4, hormone-sensitive lipase, and adiponectin in white adipose tissue that was associated with the increase in insulin sensitivity. At 24 weeks, the shortening fraction (SF) of placebo DKO mice was 30% lower than that of C57BL6 mice. The PPAR agonist increased PPARγ but not PPARα expression in the heart and prevented loss of left ventricular function. Adiponectin correlated positively with PPARγ in the heart and with SF. The agonist had no effect on atherosclerosis in the aortic arch of DKO mice.

Conclusions—

The dual PPARα,γ-agonist improved insulin sensitivity without affecting cholesterol and triglycerides. This was associated with induction of PPARγ in the heart and prevention of loss of left ventricle function.
Endothelial NO Synthase Deficiency Promotes Smooth Muscle Progenitor Cells in Association With Upregulation of Stromal Cell-Derived Factor-1α in a Mouse Model of Carotid Artery Ligation
Authors: Zhang Le-Ning , Wilson Dennis W. , da Cunha Valdeci , Sullivan Mark E. , Vergona Ronald , Rutledge John C. , Wang Yi-Xin
Published: February 2006

Background—Endothelial NO deficiency (endothelial NO synthase [eNOS]–knockout [KO]) enhanced smooth muscle cell (SMC)–rich neointimal lesion formation in a mouse model of carotid artery ligation (CAL). Recent evidence indicated that stromal cell-derived factor-1α (SDF-1α)–mediated recruitment of circulating SMC progenitor cells substantially contributed to the SMC-rich neointimal hyperplasia induced by vascular injury. The goal of this study was to investigate the effects of eNOS deficiency on the expression of SDF-1α and mobilization of circulating SMC progenitor cells in CAL model.

Methods and Results—Two- to 3-month-old C57BL/6J wild-type (WT) and eNOS-KO mice were evaluated 1, 2, or 4 weeks after CAL. CAL-induced expression of SDF-1α, as detected by immunohistochemical staining and further quantified by ELISA in the ligated carotid arteries, was moderate and transient with a peak at 1 week in WT mice. SDF-1α expression was significantly higher at 1 week and persisted through 2 weeks in eNOS-KO mice. CAL was associated with increased circulating stem cell antigen-1+ (Sca-1+)/c-Kit−/Lin−cells (interpreted as SMC progenitor cells), which peaked at 1 week in WT mice. This effect was also significantly greater and longer-lasting in eNOS-KO than WT mice. The number of circulating Sca-1+/c-Kit−/Lin−cells was positively correlated with the expression of SDF-1α but not vascular endothelial growth factor in the ligated carotid arteries. Furthermore, immunostaining showed abundant Sca-1–positive cells in the adventitia of the 1-week ligated carotid arteries from eNOS-KO mice but not in WT mice. We also determined that eNOS deficiency enhanced CAL-induced intimal cell proliferation in the ligated arteries as detected by proliferating cell nuclear antigen staining but did not induce cell apoptosis as detected by staining for active caspase-3.

Conclusion—Our results indicate that eNOS deficiency exacerbates CAL-induced expression of SDF-1α and its receptor CXCR4. This is correlated with an increase in Sca-1+cells in peripheral blood and adventitia, which may contribute to vascular remodeling and SMC-rich neointimal lesion formation. This suggests that constitutive eNOS inhibits SDF-1α expression and provides an important vasculoprotective mechanism for intact endothelium to limit SMC proliferation and recruitment in response to vascular injury.
Molecular Signatures Determining Coronary Artery and Saphenous Vein Smooth Muscle Cell Phenotypes
Authors: Deng David Xing-Fei , Spin Joshua M. , Tsalenko Anya , Vailaya Aditya , Ben-Dor Amir , Yakhini Zohar , Tsao Phil , Bruhn Laurakay , Quertermous Thomas
Published: February 2006

Objective—

Phenotypic differences between vascular smooth muscle cell (VSMC) subtypes lead to diverse pathological processes including atherosclerosis, postangioplasty restenosis and vein graft disease. To better understand the molecular mechanisms underlying functional differences among distinct SMC subtypes, we compared gene expression profiles and functional responses to oxidized low-density lipoprotein (OxLDL) and platelet-derived growth factor (PDGF) between cultured SMCs from human coronary artery (CASM) and saphenous vein (SVSM).

Methods and Results—

OxLDL and PDGF elicited markedly different functional responses and expression profiles between the 2 SMC subtypes. In CASM, OxLDL inhibited cell proliferation and migration and modified gene expression of chemokines (CXCL10, CXCL11 and CXCL12), proinflammatory cytokines (IL-1, IL-6, and IL-18), insulin-like growth factor binding proteins (IGFBPs), and both endothelial and smooth muscle marker genes. In SVSM, OxLDL promoted proliferation partially via IGF1 signaling, activated NF-κB and phosphatidylinositol signaling pathways, and upregulated prostaglandin (PG) receptors and synthases. In untreated cells, α-chemokines, proinflammatory cytokines, and genes associated with apoptosis, inflammation, and lipid biosynthesis were higher in CASM, whereas some β-chemokines, metalloproteinase inhibitors, and IGFBPs were higher in SVSM. Interestingly, the basal expression levels of these genes seemed closely related to their responses to OxLDL and PDGF. In summary, our results suggest dramatic differences in gene expression patterns and functional responses to OxLDL and PDGF between venous and arterial SMCs, with venous SMCs having stronger proliferative/migratory responses to stimuli but also higher expression of atheroprotective genes at baseline.

Conclusions—

These results reveal molecular signatures that define the distinct phenotypes characteristics of coronary artery and saphenous vein SMC subtypes.
Thrombomodulin Gene Polymorphisms and Haplotypes and the Risk of Cardiovascular Events
Authors: Auro K. , Komulainen K. , Alanne M. , Silander K. , Peltonen L. , Perola M. , Salomaa V.
Published: February 2006

Background—

Thrombomodulin is an anticoagulant expressed during endothelial activation and damage. To address the potential role of allelic variants of thrombomodulin gene in the pathogenesis of cardiovascular diseases, we analyzed in a prospective follow-up study 8 single-nucleotide polymorphisms (SNPs) across the thrombomodulin locus, covering all common (>5%) haplotypes.

Methods and Results—

Two separate, stratified random samples of men and women 25 to 74 years of age were examined in Finland in 1992 and 1997. The total sample size was 14 140 individuals, with 7 (1997 cohort) to 10 (1992 cohort) years of follow-up. Altogether, 662 individuals had a history of cardiovascular events already at baseline. During the follow-up, 401 incident coronary events and 148 incident ischemic strokes were observed. The alleles and common haplotypes of 8 SNPs were tested in Cox proportional hazards models using incident coronary events, incident ischemic strokes, and total mortality as end points. None of the SNPs or major SNP haplotypes showed consistent association with the end points analyzed in the combined data.

Conclusions—

Results from this prospective, population-based study suggest that common allelic variants of the thrombomodulin gene may not significantly contribute to the risk of cardiovascular events at the population level.
Role of Small GTPases in Endothelial Cytoskeletal Dynamics and the Shear Stress Response
Authors: Tzima Eleni
Published: February 2006

Fluid shear stress caused by blood flow is a major determinant of vascular remodeling and arterial tone and can lead to development of atherosclerosis. The endothelial monolayer in vivo acts as a signal transduction interface for hemodynamic forces; these forces determine the shape, cytoskeletal organization, and function of endothelial cells, allowing the vessels to cope with physiological or pathological conditions. The Ras superfamily of GTPases have been revealed to be master regulators of many cellular activities. In particular, the GTPases RhoA, Rac1, and Cdc42 are known to regulate cell shape changes through effects on the cytoskeleton, but their ability to influence polarity, microtubule dynamics, and transcription factor activity is just as significant. Shear stress modulates the activity of small GTPases, which are critical for both cytoskeletal reorganization and changes in gene expression in response to shear stress. The goal of this article is to review what is known about Ras and more so about Rho GTPases in mechanotransduction and the responses of cells to fluid flow. Several distinct signaling pathways can be coordinately activated by flow, and small GTPases are strongly implicated in some of them; thus possible connections will be explored and a unifying hypothesis offered.
Early Growth Response-1 in Cardiovascular Pathobiology
Authors: Khachigian Levon M.
Published: February 2006

The immediate-early gene product and zinc finger transcription factor early growth response (Egr)-1 plays a key master regulatory role in multiple cardiovascular pathological processes. This article reviews the amassing recent evidence implicating Egr-1 in atherosclerosis, intimal thickening after acute vascular injury, ischemic pathology, angiogenesis, allograft rejection, and cardiac hypertrophy.
An In Vivo Analysis of Hematopoietic Stem Cell Potential
Authors: Visconti Richard P. , Ebihara Yasuhiro , LaRue Amanda C. , Fleming Paul A. , McQuinn Tim C. , Masuya Masahiro , Minamiguchi Hitoshi , Markwald Roger R. , Ogawa Makio , Drake Christopher J.
Published: February 2006

Recent studies evaluating hematopoietic stem cell (HSC) potential raise the possibility that, in addition to embryonic sources, adult valve fibroblasts may be derived from HSCs. To test this hypothesis, we used methods that allow the potential of a single HSC to be evaluated in vivo. This was achieved by isolation and clonal expansion of single lineage-negative (Lin
−
), c-kit
+
, Sca-1
+
, CD34
−
cells from the bone marrow of mice that ubiquitously express enhanced green fluorescent protein (EGFP) combined with transplantation of individual clonal populations derived from these candidate HSCs into a lethally irradiated congenic non-EGFP mouse. Histological analyses of valve tissue from clonally engrafted recipient mice revealed the presence of numerous EGFP
+
cells within host valves. A subpopulation of these cells exhibited synthetic properties characteristic of fibroblasts, as evidenced by their expression of mRNA for procollagen 1α1. Further, we show by Y-chromosome–specific fluorescence in situ hybridization analysis of female-to-male transplanted mice that the EGFP
+
valve cells are the result of HSC-derived cell differentiation and not the fusion of EGFP
+
donor cells with host somatic cells. Together, these findings demonstrate HSC contribution to the adult valve fibroblast population.
Identification of Prostaglandin E2 Receptor Subtype 2 As a Receptor Activated by OxPAPC
Authors: Li Rongsong , Mouillesseaux Kevin P. , Montoya Dennis , Cruz Daniel , Gharavi Navid , Dun Martin , Koroniak Lukasz , Berliner Judith A.
Published: February 2006

Oxidized 1-palmitoyl-2-arachidonoyl-
sn
-glycero-3-phosphorylcholine (OxPAPC), which has been shown to accumulate in atherosclerotic lesions and other sites of chronic inflammation, activates endothelial cells (EC) to bind monocytes by activation of endothelial β1 integrin and subsequent deposition of fibronectin on the apical surface. Our previous studies suggest this function of OxPAPC is mediated via a Gs protein–coupled receptor (GPCR). PEIPC (1-palmitoyl-2-epoxyisoprostane E2-
sn
-glycero-3-phosphorylcholine) is the most active lipid in OxPAPC that activates this pathway. We screened a number of candidate GPCRs for their interaction with OxPAPC and PEIPC, using a reporter gene assay; we identified prostaglandin E2 receptor EP2 and prostaglandin D2 receptor DP as responsive to OxPAPC. We focused on EP2, which is expressed in ECs, monocytes, and macrophages. OxPAPC component PEIPC, but not POVPC, activated EP2 with an EC
50
of 108.6 nmol/L. OxPAPC and PEIPC were also able to compete with PGE2 for binding to EP2 in a ligand-binding assay. The EP2 specific agonist butaprost was shown to mimic the effect of OxPAPC on the activation of β1 integrin and the stimulation of monocyte binding to endothelial cells. Butaprost also mimicked the effect of OxPAPC on the regulation of tumor necrosis factor-α and interleukin-10 in monocyte-derived cells. EP2 antagonist AH6809 blocked the activation of EP2 by OxPAPC in HEK293 cells and blocked the interleukin-10 response to PEIPC in monocytic THP-1 cells. These results suggest that EP2 functions as a receptor for OxPAPC and PEIPC, either as the phospholipid ester or the released fatty acid, in both endothelial cells and macrophages.
Foxc2 Is a Common Mediator of Insulin and Transforming Growth Factor β Signaling to Regulate Plasminogen Activator Inhibitor Type I Gene Expression
Authors: Fujita Hideo , Kang Myengmo , Eren Mesut , Gleaves Linda A. , Vaughan Douglas E. , Kume Tsutomu
Published: February 2006

Elevated plasma levels of plasminogen activator inhibitor type I (PAI-1), a significant risk factor of ischemic heart disease, are associated with insulin resistance in which insulin and transforming growth factor (TGF)-β play a pivotal role in regulating PAI-1 production. Forkhead transcription factor FOXC2 is an important regulator of insulin resistance. However, the underlying molecular mechanisms to link FOXC2 to PAI-1 levels in insulin resistance remain to be elucidated. Here, we demonstrate that Foxc2 is a common transcriptional activator of insulin and TGF-β signaling to directly regulate PAI-1 expression via 2 distinct target sites, an insulin response element (IRE) and a novel forkhead-binding element (FBE), adjacent to a Smad-binding site. We found that in adipocytes and endothelial cells Foxc2 mediates insulin action competing with another Forkhead protein, FOXO1, via the insulin response element, and simultaneously cooperate with the TGF-β/Smad pathway to transactivate PAI-1. Importantly, Foxc2 haploinsufficiency in mice significantly attenuates TGF-β1–induced PAI-1 expression in the cardiovascular system and adipose tissue. Taken together, we propose that Foxc2 is a key molecule to regulate PAI-1 gene expression.
Endogenous RGS Proteins and Gα Subtypes Differentially Control Muscarinic and Adenosine-Mediated Chronotropic Effects
Authors: Fu Ying , Huang Xinyan , Zhong Huailing , Mortensen Richard M. , D’Alecy Louis G. , Neubig Richard R.
Published: February 2006

Cardiac automaticity is controlled by G protein–coupled receptors, such as adrenergic, muscarinic, and adenosine receptors. The strength and duration of G protein signaling is attenuated by regulator of G protein signaling (RGS) proteins acting as GTPase-activating proteins for Gα subunits; however, little is known about the role of endogenous RGS proteins in cardiac function. We created point mutations in Gα subunits that disrupt Gα-RGS binding and introduced them into embryonic stem (ES) cells by homologous recombination. Spontaneously contacting cardiocytes derived from the ES cells were used to evaluate the role of endogenous RGS proteins in chronotropic regulation. The RGS-insensitive GαoG184S homozygous knock-in (GαoGS/GS) cells demonstrated enhanced adenosine A1and muscarinic M2receptor–mediated bradycardic responses. In contrast, Gαi2GS/GS cells showed enhanced responses to M2but not A1receptors. Similarly M2but not A1bradycardic responses were dramatically enhanced in Gαi2GS/GS mice. Blocking G protein–coupled inward rectifying K+(GIRK) channels largely abolished the mutation-induced enhancement of the M2receptor–mediated response but had a minimal effect on A1responses. The Gαs-dependent stimulation of beating rate by the β2adrenergic receptor agonist procaterol was significantly attenuated in GαoGS/GS and nearly abolished in Gαi2GS/GS cells because of enhanced signaling via a pertussis toxin sensitive mechanism. Thus, endogenous RGS proteins potently reduce the actions of Gαi/o-linked receptors on cardiac automaticity. Furthermore, M2and A1receptors differentially use Gαi2and Gαoand associated downstream effectors. Thus, alterations in RGS function may play a role in pathophysiological processes and RGS proteins could represent novel cardiovascular therapeutic targets.
Spontaneous Coronary Vasospasm in

K
ATP

Mutant Mice Arises From a Smooth Muscle–Extrinsic Process
Authors: Kakkar Rahul , Ye Bin , Stoller Douglas A. , Smelley Matthew , Shi Nian-Qing , Galles Kevin , Hadhazy Michele , Makielski Jonathan C. , McNally Elizabeth M.
Published: February 2006

In the vasculature, ATP-sensitive potassium channels (K
ATP
) channels regulate vascular tone. Mice with targeted gene disruptions of K
ATP
subunits expressed in vascular smooth muscle develop spontaneous coronary vascular spasm and sudden death. From these models, it was hypothesized that the loss of K
ATP
channel activity in arterial vascular smooth muscle was responsible for coronary artery spasm. We now tested this hypothesis using a transgenic strategy where the full-length sulfonylurea receptor containing exon 40 was expressed under the control of a smooth muscle–specific SM22α promoter. Two transgenic founder lines were generated and independently bred to sulfonylurea receptor 2 (SUR2) null mice to generate mice that restored expression of K
ATP
channels in vascular smooth muscle. Transgenic expression of the sulfonylurea receptor in vascular smooth muscle cells was confirmed by detecting mRNA and protein from the transgene. Functional restoration was determined by recording pinacidil-based K
ATP
current by whole cell voltage clamping of isolated aortic vascular smooth muscle cells isolated from the transgenic restored mice. Despite successful restoration of K
ATP
channels in vascular smooth muscle, transgene-restored SUR2 null mice continued to display frequent episodes of spontaneous ST segment elevation, identical to the phenotype seen in SUR2 null mice. As in SUR2 null mice, ST segment elevation was frequently followed by atrioventricular heart block. ST segment elevation and coronary perfusion pressure in the restored mice did not differ significantly between transgene-negative and transgene-positive SUR2 null mice. We conclude that spontaneous coronary vasospasm and sudden death in SUR2 null mice arises from a coronary artery vascular smooth muscle–extrinsic process.
What Patients Want
Authors: Ali Khalid , Roffe Christine , Crome Peter
Published: February 2006

Background and Purpose—

To involve stroke patients and carers in the design of a study of oxygen supplementation in acute stroke and to obtain their views on the importance of the study, consent issues, relevance, and acceptability of the outcome measures, and the preferred method of follow-up.

Methods—

This study involved qualitative and quantitative research. Three focus group meetings were held with individuals who have had personal experience of stoke, mostly stoke patients and their partners or carers (an association of young stroke sufferers and 2 dysphasia support groups each from a different town in the West Midlands, UK). The researchers explained the planned oxygen supplementation study and encouraged participants to comment and make suggestions in a semistructured interview. The audience was then asked to complete a questionnaire relating to the study.

Results—

Seventy-three people (67% stroke patients and 33% carers; mean age 64; range 31 to 86 years; and 47% males) attended the 3 meetings. The overall response rate to the questionnaires was 70%. Most of the respondents considered the study worthwhile (97%) and the planned outcome measures relevant. In addition, assessment of speech, memory, sleep, and cognitive function was raised by >20% of respondents as important outcomes. Seventy-five percent would agree with assent from a family member on behalf of incompetent patients, and 92% would agree to a doctor recruiting incompetent patients to the study and seeking consent/assent later. The majority of respondents (80%) preferred personal contact with the researcher or a representative to a questionnaire for follow-up.

Conclusions—

Involvement of stroke patients and carers helped us identify outcome measures that are important to the stroke population but not routinely addressed in stroke assessment scales. A high proportion of respondents asked for waiver of consent and agreed to family’s assent on behalf of incompetent patients. Although consumer involvement has helped us to make the study more relevant to the public, it has also led to difficult scientific and ethical conflicts in protocol design.
Anterior-Posterior Ground Reaction Forces as a Measure of Paretic Leg Contribution in Hemiparetic Walking
Authors: Bowden Mark G. , Balasubramanian Chitralakshmi K. , Neptune Richard R. , Kautz Steven A.
Published: February 2006

Background and Purpose—

Walking after stroke is characterized by slow gait speed, poor endurance, reduced quality and adaptability of walking patterns, and an inability to coordinate the legs. Estimates based on mechanical work calculations have suggested that the paretic leg does 30% to 40% of the total mechanical work over the gait cycle, regardless of hemiparetic severity, but these work estimates may not describe the contribution of each leg to forward propulsion. The purpose of this study was to establish a quantifiable link between hemiparetic severity and paretic leg contribution to propulsion during walking, which we propose to quantify using a measure based on the anterior-posterior ground reaction forces (A-P GRFs).

Methods—

A total of 47 participants with chronic hemiparesis walked at self-selected speeds to collect spatiotemporal parameters and 3D GRFs. A 16-person subset also participated in a pedaling protocol to compare A-P GRF measures to established measures of paretic leg output.

Results—

A-P GRF measures were correlated with both walking speed and hemiparetic severity. These measures were also strongly correlated with positive work and net work values obtained during the pedaling task. The percentage of total propulsion generated by the paretic leg (P
P
) was calculated and found to be 16%, 36%, and 49% for those with high, moderate, and low hemiparetic severity, respectively.

Conclusion—

P
P
was found to provide a quantitative measure of the coordinated output of the paretic leg. Further research on this measure of forward propulsion may lead to the provision of an effective tool for distinguishing functional compensation from physiological restitution.