bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel quantitative phenotypes of exercise training in mouse models
Authors: De Bono J. P. , Adlam D. , Paterson D. J. , Channon K. M.
Published: December 2005

Regular physical exercise has beneficial effects in many human disease states, including cardiovascular diseases, cancer, and depression. Exercise training of genetically modified mouse models may provide insight into the molecular mechanisms that underlie the beneficial effects of exercise. Presently, there is relatively little understanding of the normal physiology of mouse exercise. In this paper, we describe a novel computerized voluntary wheel-running system capable of recording and analyzing individual wheel rotations. Using this system, we demonstrate that C57BL/6 mice run considerable distances during the night in short bouts and at a preferred speed: the cruising speed. We find that the vast majority of running occurs around this cruising speed, which is close to the maximum speed at which the animal can run but is significantly higher than the average speeds recorded by simple digital odometers. We describe how these parameters vary with exercise training and demonstrate marked sex differences in the patterns of voluntary exercise. The results of this study have important implications for the design and interpretation of both voluntary and forced exercise experiments in mouse models. The novel parameters described provide more physiological quantitative measures of voluntary exercise activity and training and will extend the physiological utility of exercise training as a phenotyping tool in genetic mouse models.
Altered circadian rhythm reentrainment to light phase shifts in rats with low levels of brain angiotensinogen
Authors: Campos Luciana A. , Plehm Ralph , Cipolla-Neto José , Bader Michael , Baltatu Ovidiu C.
Published: December 2005

In this study, we aimed to investigate the adaptation of blood pressure (BP), heart rate (HR), and locomotor activity (LA) circadian rhythms to light cycle shift in transgenic rats with a deficit in brain angiotensin [TGR(ASrAOGEN)]. BP, HR, and LA were measured by telemetry. After baseline recordings (bLD), the light cycle was inverted by prolonging the light by 12 h and thereafter the dark period by 12 h, resulting in inverted dark-light (DL) or light-dark (LD) cycles. Toward that end, a 24-h dark was maintained for 14 days (free-running conditions). When light cycle was changed from bLD to DL, the acrophases (peak time of curve fitting) of BP, HR, and LA shifted to the new dark period in both SD and TGR(ASrAOGEN) rats. However, the readjustment of the BP and HR acrophases in TGR(ASrAOGEN) rats occurred significantly slower than SD rats. The LA acrophases changed similarly in both strains. When light cycle was changed from DL to LD by prolonging the dark period by 12 h, the reentrainment of BP and LA occurred faster than the previous shift in both strains. The readjustment of the BP and HR acrophases in TGR(ASrAOGEN) rats occurred significantly slower than SD rats. In free-running conditions, the circadian rhythms of the investigated parameters adapted in TGR(ASrAOGEN) and SD rats in a similar manner. These results demonstrate that the brain RAS plays an important role in mediating the effects of light cycle shifts on the circadian variation of BP and HR. The adaptive behavior of cardiovascular circadian rhythms depends on the initial direction of light-dark changes.
Regulation of ROMK (Kir1.1) channels: new mechanisms and aspects
Authors: Wang Wen-Hui
Published: December 2005

This brief review attempts to provide an overview regarding recent developments in the regulation of ROMK channels. Studies performed in ROMK null mice suggest that ROMK cannot only form hometetramers such as the small-conductance (30-pS) K channels but also construct heterotetramers such as the 70-pS K channel in the thick ascending limb (TAL). The expression of ROMK channels in the plasma membrane is regulated by protein tyrosine kinase (PTK), serum and glucorticoid-induced kinase (SGK), and with-no-lysine-kinase 4. PTK is involved in mediating the effect of low K intake on ROMK channel activity. Increases in superoxide anions induced by low dietary K intake are responsible for the stimulation of PTK expression and tyrosine phosphorylation of ROMK channels. Finally, a recent study indicated that ROMK channels can be monoubiquitinated and monoubiquitination regulates the surface expression of ROMK channels.
Exercise training in normobaric hypoxia in endurance runners. II. Improvement of mitochondrial properties in skeletal muscle
Authors: Ponsot Elodie , Dufour Stéphane P. , Zoll Joffrey , Doutrelau Stéphane , N'Guessan Benoit , Geny Bernard , Hoppeler Hans , Lampert Eliane , Mettauer Bertrand , Ventura-Clapier Renée , Richard Ruddy
Published: December 2005

This study investigates whether adaptations of mitochondrial function accompany the improvement of endurance performance capacity observed in well-trained athletes after an intermittent hypoxic training program. Fifteen endurance-trained athletes performed two weekly training sessions on treadmill at the velocity associated with the second ventilatory threshold (VT2) with inspired O2fraction = 14.5% [hypoxic group (Hyp), n = 8] or with inspired O2fraction = 21% [normoxic group (Nor), n = 7], integrated into their usual training, for 6 wk. Before and after training, oxygen uptake (V̇o2) and speed at VT2, maximal V̇o2(V̇o2 max), and time to exhaustion at velocity of V̇o2 max(minimal speed associated with V̇o2 max) were measured, and muscle biopsies of vastus lateralis were harvested. Muscle oxidative capacities and sensitivity of mitochondrial respiration to ADP ( Km) were evaluated on permeabilized muscle fibers. Time to exhaustion, V̇o2at VT2, and V̇o2 maxwere significantly improved in Hyp (+42, +8, and +5%, respectively) but not in Nor. No increase in muscle oxidative capacity was obtained with either training protocol. However, mitochondrial regulation shifted to a more oxidative profile in Hyp only as shown by the increased Kmfor ADP (Nor: before 476 ± 63, after 524 ± 62 μM, not significant; Hyp: before 441 ± 59, after 694 ± 51 μM, P < 0.05). Thus including hypoxia sessions into the usual training of athletes qualitatively ameliorates mitochondrial function by increasing the respiratory control by creatine, providing a tighter integration between ATP demand and supply.
Direct vasoactive and vasoprotective properties of anthocyanin-rich extracts
Authors: Bell David R. , Gochenaur Kristen
Published: December 2005

Reactive oxygen species (ROS) play a critical role in the impairment of nitric oxide-mediated vascular functions and overall pathogenesis associated with cardiovascular disease. Plant pigment anthocyanins are exceptionally potent oxygen radical scavengers that produce beneficial effects in diseases outside the cardiovascular system. We examined for the first time the potential coronary vasoactive and vasoprotective properties of three anthocyanin enhanced extracts prepared from chokeberry (Ck), bilberry (B), or elderberry (E). Coronary arterial rings were isolated from 64 pigs and incubated in sterile tissue culture media overnight for use in one of four separate in vitro isometric force recording studies. Ck and B, but not E, produced dose- and endothelium-dependent vasorelaxation. (%maximal relaxation at 5 mg total anthocyanins per liter: Ck = 68 ± 11, B = 59 ± 10). Coronary vascular tone, endothelium-dependent vasorelaxation to A23187 , and vasorelaxation to DEA NONOate were not affected by exposure of rings to any extract at 0.05 mg total anthocyanins per liter for 5 or 30 min. Ck extract at 0.05 mg total anthocyanins per liter showed the greatest protection against loss of A23187 relaxation following exposure to ROS from pyrogallol (Ck, % maximal relaxation and −logED50to A23187 , respectively, means ± SE: Ck alone, 93 ± 5%, 7.91 ± 0.1; pyrogallol alone, 76 ± 7%, 7.46 ± 0.06; pyrogallol + Ck, 98 ± 1%, 7.82 ± 0.06; control: 99 ± 1%, 7.86 ± 0.07; P < 0.05 control vs. pyrogallol alone). Neither the extracts nor pyrogallol affected responses to DEA NONOate. Thus anthocyanin-enhanced extracts produce endothelium-dependent relaxation in porcine coronary arteries. Extract concentrations too low to directly alter coronary vascular tone protect coronary arteries from ROS without altering vasorelaxation to endogenous or exogenous NO. These results suggest that such extracts could have significant beneficial effects in vascular disease.
Use of ultrasound to make noninvasive in vivo measurement of continuous changes in human muscle contractile length
Authors: Loram Ian D. , Maganaris Constantinos N. , Lakie Martin
Published: December 2005

Continuous measurement of contractile length has been traditionally achieved using animal preparations in which the muscle and tendon are exposed. More modern methods, e.g., sonomicroscopy, are still invasive. There is a widely perceived need for a noninvasive, in vivo method of measuring continuous changes of human muscle contractile length. Ultrasonography has been used for several years to measure relatively static, discrete changes in tendon, aponeurosis, and muscle fascicle length. We have recently developed this technique to continuously track changes in muscle contractile length during quiet standing. Here, we present the tracking algorithm and use externally applied perturbations to establish the spatial and temporal resolution of the technique. Subjects maintained a low level of ankle torque while a pneumatic actuator applied rapid, square-pulse ankle rotations of defined magnitude and 0.2-s duration. Tracked changes in gastrocnemius and soleus contractile length follow the temporal profile of the perturbations and scale progressively (5–400 μm) with the size of the ankle rotation (0.03–0.7°). In a second experiment, we tracked a wire oscillating in water with known peak to peak amplitudes of 1.5 μm to 8 mm. The ultrasound tracking procedure had near 100% accuracy at all amplitudes for frequencies up to 3 Hz and showed attenuation at higher frequencies consistent with an effective sampling frequency of 12 Hz and sampling time of 80 ms. This noninvasive technique is sensitive, without averaging, to changes as small as 1 μm and is suitable for observing neuromotor activity in posture and locomotion.
Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training
Authors: Abe Takashi , Kearns Charles F. , Sato Yoshiaki
Published: December 2005

Previous studies have shown that low-intensity resistance training with restricted muscular venous blood flow (Kaatsu) causes muscle hypertrophy and strength gain. To investigate the effects of daily physical activity combined with Kaatsu, we examined the acute and chronic effects of walk training with and without Kaatsu on MRI-measured muscle size and maximum dynamic (one repetition maximum) and isometric strength, along with blood hormonal parameters. Nine men performed Kaatsu-walk training, and nine men performed walk training alone (control-walk). Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min), with a 1-min rest between bouts. Mean oxygen uptake during Kaatsu-walk and control-walk exercise was 19.5 (SD 3.6) and 17.2 % (SD 3.1) of treadmill-determined maximum oxygen uptake, respectively. Serum growth hormone was elevated ( P < 0.01) after acute Kaatsu-walk exercise but not in control-walk exercise. MRI-measured thigh muscle cross-sectional area and muscle volume increased by 4–7%, and one repetition maximum and maximum isometric strength increased by 8–10% in the Kaatsu-walk group. There was no change in muscle size and dynamic and isometric strength in the control-walk group. Indicators of muscle damage (creatine kinase and myoglobin) and resting anabolic hormones did not change in both groups. The results suggest that the combination of leg muscle blood flow restriction with slow-walk training induces muscle hypertrophy and strength gain, despite the minimal level of exercise intensity. Kaatsu-walk training may be a potentially useful method for promoting muscle hypertrophy, covering a wide range of the population, including the frail and elderly.
Elevated Levels of Antimicrobial Peptides in Bronchoalveolar Lavage Fluid in Patients with Chronic Eosinophilic Pneumonia
Authors: Ashitani Jun-ichi , Matsumoto Nobuhiro , Nakazato Masamitsu
Published: December 2005

Background: Chronic eosinophilic pneumonia (CEP) is an idiopathic pulmonary disease. As the lung is in direct communication with the environment, inhaled antigen may activate immune mechanisms in the airway that may participate in the pathogenesis of idiopathic pulmonary diseases. Defensins are antimicrobial peptides that consist of α-defensin (HAD) in neutrophils and β-defensin (HBD) in epithelial cells. Defensins act as innate immunity against pathogens acquired from the environment and as mediators to induce local inflammation. Objectives: The aim of the present study was to determine whether immune mechanisms in the airway are induced in CEP patients. Methods: We measured BALF defensin levels in patients with CEP, acute EP (AEP) and drug-induced eosinophilic pneumonia (drug-EP). We also measured BALF levels of IL-5, GM-CSF, eotaxin and RANTES. These substances can recruit eosinophils. Results: BALF HAD levels were higher in patients with CEP than in those with drug-EP and normal controls. HBD-2 was detected in BALF of 10 of 11 CEP patients and in 3 of 5 AEP patients while its level was below detection in drug-EP patients and normal controls. BALF HBD-2 levels correlated with the proportion of lymphocytes in CEP patients. Conclusion: The defensin-linked immune system is activated in CEP but not in drug-EP. This suggests that inhaled antigen(s) may be involved in the pathogenesis of CEP.
Sleep Apnoea-Hypopnoea Index Is an Independent Predictor of High-Sensitivity C-Reactive Protein Elevation
Authors: Zouaoui Boudjeltia Karim , van Meerhaeghe Alain , Doumit Sonia , Guillaume Michel , Cauchie Philippe , Brohée Dany , Vanhaeverbeek Michel , Kerkhofs Myriam
Published: December 2005

Background: Recent reports have identified the apnoea and hypopnoea index (AHI) as an additional independent risk factor for cardiovascular morbidity and mortality. However, several studies reported contradictory results about the association between the serum C-reactive protein (CRP) level and the severity of apnoea. Objective: The purpose of this work is to study this association in patients referred to the sleep laboratory for clinical suspicion of sleep apnoea and presenting a wide range of AHI. Methods: Forty-nine consecutive patients were included in the study. The SigmaStat® software package (Jandle Scientific) was used. Multilinear regression analysis was tested using a stepwise backward selection of the explicative variables. The clinical characteristics (diabetes, hypertension, smoking habits, gender) were treated as dichotomous variables, while all other data (age, BMI, lipids, white blood cells) were continuous ones; high-sensitivity (hs)-CRP was the dependent variable. Results: In univariate analysis, AHI was correlated to hs-CRP: R = 0.43, p = 0.002. In multivariate analyses, we found an independent association between the AHI, adjusted for classical cardiovascular risk factors, and hs-CRP. Conclusion: In a sample of 49 patients, referred to the sleep laboratory for suspicion of sleep apnoea in routine practice, we observed an independent association between the AHI and hs-CRP.
Platelet Inhibition by Insulin Is Absent in Type 2 Diabetes Mellitus
Authors: Ferreira Irlando Andrade , Mocking Astrid I.M. , Feijge Marion A.H. , Gorter Gertie , van Haeften Timon W. , Heemskerk Johan W.M. , Akkerman Jan-Willem N.
Published: December 2005

Objective—

ADP-induced P2y
12
signaling is crucial for formation and stabilization of an arterial thrombus. We demonstrated recently in platelets from healthy subjects that insulin interferes with Ca
2+
increases induced by ADP-P2y
1
contact through blockade of the G-protein G
i
, and thereby with P2y
12
-mediated suppression of cAMP.

Methods and Results—

Here we show in patients with type 2 diabetes mellitus (DM2) that platelets have lost responsiveness to insulin leading to increased adhesion, aggregation, and procoagulant activity on contact with collagen. Using Ser
473
phosphorylation of protein kinase B as output for insulin signaling, a 2-fold increase is found in insulin-stimulated normal platelets, but in DM platelets there is no significant response. In addition, DM2 platelets show increased P2y
12
-mediated suppression of cAMP and decreased P2y
12
inhibition by the receptor antagonist AR-C69931MX.

Conclusion—

The loss of responsiveness to insulin together with increased signaling through P2y
12
might explain the hyperactivity of platelets in patients with DM2.
Differential Regulation of Hyaluronic Acid Synthase Isoforms in Human Saphenous Vein Smooth Muscle Cells
Authors: van den Boom M. , Sarbia M. , von Wnuck Lipinski K. , Mann P. , Meyer-Kirchrath J. , Rauch B.H. , Grabitz K. , Levkau B. , Schrör K. , Fischer J.W.
Published: December 2005

Autologous saphenous vein bypass grafts (SVG) are frequently compromised by neointimal thickening and subsequent atherosclerosis eventually leading to graft failure. Hyaluronic acid (HA) generated by smooth muscle cells (SMC) is thought to augment the progression of atherosclerosis. The aim of the present study was (1) to investigate HA accumulation in native and explanted arterialized SVG, (2) to identify factors that regulate HA synthase (HAS) expression and HA synthesis, and (3) to study the function of the HAS2 isoform. In native SVG, expression of all 3 HAS isoforms was detected by RT-PCR. Histochemistry revealed that native and arterialized human saphenous vein segments were characterized by marked deposition of HA in association with SMC. Interestingly, in contrast to native SVG, cyclooxygenase (COX)-2 expression by SMC and macrophages was detected only in arterialized SVG. In vitro in human venous SMC HAS isoforms were found to be differentially regulated. HAS2, HAS1, and HA synthesis were strongly induced by vasodilatory prostaglandins via G
s
-coupled prostaglandin receptors. In addition, thrombin induced HAS2 via activation of PAR1 and interleukin 1β was the only factor that induced HAS3. By small interfering RNA against HAS2, it was shown that HAS2 mediated HA synthesis is critically involved in cell cycle progression through G
1
/S phase and SMC proliferation. In conclusion, the present study shows that HA-rich extracellular matrix is maintained after arterialization of vein grafts and might contribute to graft failure because of its proproliferative function in venous SMC. Furthermore, COX-2–dependent prostaglandins may play a key role in the regulation of HA synthesis in arterialized vein grafts.
Cardiac Myocyte Apoptosis Is Associated With Increased DNA Damage and Decreased Survival in Murine Models of Obesity
Authors: Barouch Lili A. , Gao Daqing , Chen Lei , Miller Karen L. , Xu Wenhong , Phan Alexander C. , Kittleson Michelle M. , Minhas Khalid M. , Berkowitz Dan E. , Wei Chiming , Hare Joshua M.
Published: December 2005

Disruption of leptin signaling is associated with obesity, heart failure, and cardiac hypertrophy, but the role of leptin in cardiac myocyte apoptosis is unknown. We tested the hypothesis that apoptosis increases in leptin-deficient
ob/ob
and leptin-resistant
db/db
mice and is associated with aging and left ventricular hypertrophy, increased DNA damage, and decreased survival. We studied young (2- to 3-month-old) and old (12- to 14-month-old)
ob/ob
and
db/db
mice and wild-type (WT) controls (n=2 to 4 per group). As expected, ventricular wall thickness and heart weights were similar among young
ob/ob
,
db/db
, and WT mice, but higher in old
ob/ob
and
db/db
versus old WT. Young
ob/ob
and
db/db
showed markedly elevated apoptosis by TUNEL staining and caspase 3 levels compared with WT. Differences in apoptosis were further accentuated with age. Leptin treatment significantly reduced apoptosis in
ob/ob
mice both in intact hearts and isolated myocytes. Tissue triglycerides were increased in
ob/ob
hearts, returning to WT levels after leptin repletion. Furthermore, the DNA damage marker, 8oxoG (8-oxo-7,8-dihydroguanidine), was increased, whereas the DNA repair marker, MYH glycosylase, was decreased in old
ob/ob
and
db/db
compared with old WT mice. Both
ob/ob
and
db/db
mice had decreased survival compared with WT mice. We conclude that leptin-deficient and leptin-resistant mice demonstrate increased apoptosis, DNA damage, and mortality compared with WT mice, suggesting that normal leptin signaling is necessary to prevent excess age-associated DNA damage and premature mortality. These data offer novel insights into potential mechanisms of myocardial dysfunction and early mortality in obesity.
Type I Collagen Limits VEGFR-2 Signaling by a SHP2 Protein-Tyrosine Phosphatase–Dependent Mechanism 1
Authors: Mitola Stefania , Brenchio Barbara , Piccinini Marco , Tertoolen Leon , Zammataro Luca , Breier Georg , Rinaudo Maria Teresa , den Hertog Jeroen , Arese Marco , Bussolino Federico
Published: December 2005

During angiogenesis, a combined action between newly secreted extracellular matrix proteins and the repertoire of integrins expressed by endothelial cells contributes in the regulation of their biological functions. Extracellular matrix-engaged integrins influence tyrosine kinase receptors, thus promoting a regulatory cross-talk between adhesive and soluble stimuli. For instance, vitronectin has been reported to positively regulate VEGFR-2. Here, we show that collagen I downregulates VEGF-A–mediated VEGFR-2 activation. This activity requires the tyrosine phosphatase SHP2, which is recruited to the activated VEGFR-2 when cells are plated on collagen I, but not on vitronectin. Constitutive expression of SHP2
C459S
mutant inhibits the negative role of collagen I on VEGFR-2 phosphorylation. VEGFR-2 undergoes internalisation, which is associated with dynamin II phosphorylation. Expression of SHP2
C459S
impairs receptor internalisation suggesting that SHP2-dependent dephosphorylation regulates this process. These findings demonstrate that collagen I in provisional extracellular matrix surrounding nascent capillaries triggers a signaling pathway that negatively regulates angiogenesis.
Hyperglycemia After SAH
Authors: Frontera Jennifer A. , Fernandez Andres , Claassen Jan , Schmidt Michael , Schumacher H. Christian , Wartenberg Katja , Temes Richard , Parra Augusto , Ostapkovich Noeleen D. , Mayer Stephan A.
Published: December 2005

Background and Purpose—

Hyperglycemia is common after subarachnoid hemorrhage (SAH). The extent to which prolonged hyperglycemia contributes to in-hospital complications and poor outcome after SAH is unknown.

Methods—

We studied an inception cohort of 281 SAH patients with an initial serum glucose level obtained within 3 days of SAH onset and who had at least 7 daily glucose measurements between SAH days 0 and 10. We defined mean glucose burden (GB) as the average peak daily glucose level >5.8 mmol/L (105 mg/dL). Hospital complications were recorded prospectively, and 3-month outcome was assessed with the modified Rankin scale.

Results—

The median GB was 1.8 mmol/L (33 mg/dL). Predictors of high-GB included age ≥54 years, Hunt and Hess grade III–V, poor Acute Physiology and Chronic Health Evaluation (APACHE)-2 physiological subscores, and a history of diabetes mellitus (all
P
≤0.001). In a multivariate analysis, GB was associated with increased intensive care unit length of stay (
P
=0.003) and the following complications: congestive heart failure, respiratory failure, pneumonia, and brain stem compression from herniation (all
P
<0.05). After adjusting for Hunt-Hess grade, aneurysm size, and age, GB was an independent predictor of death (odds ratio, 1.10 per mmol/L; 95% CI, 1.01 to 1.21;
P
=0.027) and death or severe disability (modified Rankin scale score of 4 to 6; odds ratio, 1.17 per mmol/L; 95% CI 1.07 to 1.28,
P
<0.001).

Conclusions—

Hyperglycemia after SAH is associated with serious hospital complications, increased intensive care unit length of stay, and an increased risk of death or severe disability.
Trends in Ethnic Disparities in Stroke Incidence in Auckland, New Zealand, During 1981 to 2003
Authors: Carter Kristie , Anderson Craig , Hacket Maree , Feigin Valery , Barber P. Alan , Broad Joanna B. , Bonita Ruth
Published: December 2005

Background and Purpose—

Although geographical variations in stroke rates are well documented, limited data exist on temporal trends in ethnic-specific stroke incidence.

Methods—

We assessed trends in ethnic-specific stroke rates using standard diagnostic criteria and community-wide surveillance procedures in Auckland, New Zealand (NZ) in 1981 to 1982, 1991 to 1992, and 2002 to 2003. Indirect and direct methods were used to adjust first-ever (incident) and total (attack) rates for changes in the structure of the population and reported with 95% CIs. Ethnicity was self-defined and categorized as “NZ/European,” “Maori,” “Pacific peoples,” and “Asian and other.”

Results—

Stroke attack (19%; 95% CI, 11% to 26%) and incidence rates (19%; 95% CI, 12% to 24%) declined significantly in NZ/Europeans from 1981 to 1982 to 2002 to 2003. These rates remained high or increased in other ethnic groups, particularly for Pacific peoples in whom stroke attack rates increased by 66% (95% CI; 11% to 225%) over the periods. Some favorable downward trends in vascular risk factors, such as cigarette smoking, were counterbalanced by increasing age, body mass index, and diabetes in certain ethnic groups.

Conclusions—

Divergent trends in ethnic-specific stroke incidence and attack rates, and of associated risk factors, have occurred in Auckland over recent decades. The findings provide mixed views as to the future burden of stroke in populations undergoing similar lifestyle and structural changes.
Matrix Metalloproteinase 2 Is Associated With Stable and Matrix Metalloproteinases 8 and 9 With Vulnerable Carotid Atherosclerotic Lesions
Authors: Sluijter Joost P.G. , Pulskens Wilco P.C. , Schoneveld Arjan H. , Velema Evelyn , Strijder Chaylendra F. , Moll Frans , de Vries Jean-Paul , Verheijen Jan , Hanemaaijer Roeland , de Kleijn Dominique P.V. , Pasterkamp Gerard
Published: December 2005

Background and Purpose—

We studied matrix metalloproteinases (MMP) 2, 8, and 9 and extracellular matrix metalloproteinase inducer (EMMPRIN) levels in relation to carotid atherosclerotic plaque characteristics.

Methods—

Carotid atherosclerotic plaques (n=150) were stained and analyzed for the presence of collagen, smooth muscle cell (SMC), and macrophages. Adjacent segments were used to isolate total protein to assess MMP-2 and MMP-9 activities and gelatin breakdown, MMP-8 activity, and EMMPRIN levels.

Results—

Macrophage-rich lesions revealed higher MMP-8 and MMP-9 activities, whereas SMC-rich lesions showed higher MMP-2 activity. The levels of less glycosylated EMMPRIN-45kD were higher in SMC-rich lesions and lower in macrophage-rich plaques. EMMPRIN-45kD was associated with MMP-2 levels, whereas EMMPRIN-58kD was related to MMP-9 levels.

Conclusions—

MMP-2, MMP-8, and MMP-9 activities differed among carotid plaque phenotypes. Different EMMPRIN glycosylation forms are associated with either MMP-2 or MMP-9 activity, which suggests that EMMPRIN glycosylation may play a role in MMP regulation and plaque destabilization.
Combining Eye Movement Desensitization and Reprocessing With Gestalt Techniques in Couples Counseling
Authors: Capps Frederick
Published: December 2005

Eye movement desensitization and reprocessing (EMDR) is gaining acceptance as efficacious treatment for posttraumatic stress disorder for individuals but not for couples. This article reports three case studies of couples in which EMDR is combined with Gestalt therapy in a single session to resolve relational trauma effects, increase empathy and awareness in the supportive partner, and deepen intimacy within the couple. Case studies are described, and implications for research and clinical applications are discussed.
Assessing the Convergent and Discriminant Validity of Goldberg’s International Personality Item Pool
Authors: Lim Beng-Chong , Ployhart Robert E.
Published: December 2005

This study examines the construct validity of the Goldberg International Personality Item Pool (IPIP) measure by comparing it to a well-developed measure of the five-factor model, the NEO Five-Factor Inventory (NEO-FFI). A sample of 353 diverse students from a large U.S. university completed both measures. Structural equation modeling was used to conduct the multitrait-multimethod, multiple-group, and latent mean analyses. A model with five correlated trait factors and two method factors provided the best fit to the data. Support for convergent and discriminant validity was also found. Racial and gender differences were relatively small for both instruments. These results support the construct validity of the IPIP. However, neither the NEO-FFI nor the IPIP produced a very good fit when analyzing item-level data, suggesting considerable room for improvement.
Identification of a gene on chromosome 12q22 uniquely overexpressed in chronic lymphocytic leukemia
Authors: Buhl Anne Mette , Jurlander Jesper , Jørgensen Flemming S. , Ottesen Anne Marie , Cowland Jack B. , Gjerdrum Lise Mette , Hansen Brian V. , Leffers Henrik
Published: December 2005

The pathogenesis of chronic lymphocytic leukemia (CLL) is unknown but may involve aberrant activation of signaling pathways. Somatic hypermutations in rearranged immunoglobulin heavy-chain (IgVH) genes allow a division of CLL patients into 2 categories: mutated IgVH genes are associated with an indolent disease, whereas unmutated IgVH genes define an aggressive form. Using differential display to compare gene expression in CLL cells with and without IgVH hypermutations, we identified a novel gene, CLL up-regulated gene 1 (CLLU1), that was highly up-regulated in CLL cells without IgVH hypermutations. CLLU1 mapped to chromosome 12q22, within a cluster of genes that are active in germinal center B cells. However, appreciable levels of CLLU1 were detectable only in CLL cells and not in a panel of normal tissue extracts or in any other tested hematologic malignancy. High expression of CLLU1 in CLL samples occurred irrespective of trisomy 12 or large chromosomal rearrangements. CLLU1 encodes 6 mRNAs with no sequence homology to any known gene, and most transcripts appear to be noncoding. Two transcripts, however, potentially encode a peptide with remarkable structural similarity to human interleukin 4. These data, in particular the unique and restricted expression pattern, suggest that CLLU1 is the first disease-specific gene identified in CLL.
Evidence for incorporation of bone marrow–derived endothelial cells into perfused blood vessels in tumors
Authors: Duda Dan G. , Cohen Kenneth S. , Kozin Sergey V. , Perentes Jean Y. , Fukumura Dai , Scadden David T. , Jain Rakesh K.
Published: December 2005

Recent studies have demonstrated that the cellular contribution of the bone marrow to tumor neovascularization is highly complex. In this context, the extent to which bone marrow–derived cells incorporate as bona fide endothelial (nonhematopoietic) cells into perfused tumor vessels, or any new vessels formed postnatally (vasculogenesis), is unclear. To this end, we developed models to characterize local vessel–derived and bone marrow–derived endothelial cells (BMD-ECs). Then, we characterized the BMD-ECs based on a set of endothelial markers and morphology. Finally, we quantified their contribution to perfused blood vessels in tumors using transplanted as well as spontaneous primary and metastatic tumor models. We demonstrate that BMD-ECs incorporate in perfused tumor vessels, and that this contribution varies with organ site and mouse strain.
Flow cytometric detection of circulating myeloma cells before transplantation in patients with multiple myeloma: a simple risk stratification system
Authors: Dingli David , Nowakowski Grzegorz S. , Dispenzieri Angela , Lacy Martha Q. , Hayman Suzanne R. , Rajkumar S. Vincent , Greipp Philip R. , Litzow Mark R. , Gastineau Dennis A. , Witzig Thomas E. , Gertz Morie A.
Published: December 2005

Detection of circulating myeloma cells (CMCs) by flow cytometry in patients with multiple myeloma (MM) indicates active disease. We hypothesized that detection of CMCs at the time of stem-cell collection prior to autologous stem-cell transplantation (ASCT) identifies patients at high risk of rapid progression. A cohort of patients undergoing ASCT was identified. CMCs were determined by gating on CD38+/CD45- cells using flow cytometry. The impact of CMCs on overall survival (OS) and time to progression (TTP) was evaluated in univariate and multivariate analyses. Of 246 patients undergoing ASCT, 95 had CMCs. Complete response (CR) rates after transplantation were 32% and 36% for patients with and without CMCs, respectively (P = .50). OSs were 33.2 and 58.6 months (P = .01) whereas TTPs were 14.1 and 22 months, respectively (P = .001). On multivariate analysis, CMCs remained independent of cytogenetics and disease status at time of transplantation (P = .03). CMCs and cytogenetics were combined in a new scoring system. Patients with neither, one, or both parameters had a median OS of 55, 48, and 21.5 months and a median TTP of 22, 15.4, and 6.5 months, respectively. CMCs at the time of ASCT is an independent prognostic factor and in combination with cytogenetics provides a powerful scoring system that stratifies patients and guides management.
Toward the identification of a tolerogenic signature in IDO-competent dendritic cells
Authors: Orabona Ciriana , Puccetti Paolo , Vacca Carmine , Bicciato Silvio , Luchini Alessandra , Fallarino Francesca , Bianchi Roberta , Velardi Enrico , Perruccio Katia , Velardi Andrea , Bronte Vincenzo , Fioretti Maria Cristina , Grohmann Ursula
Published: December 2005

Although much is known about the transcriptional profiles of dendritic cells (DCs) during maturation, the molecular switches critical for the induction of a tolerogenic program in DC subsets are still obscure. We examined the gene-expression profiles of murine splenic CD8+ DCs rendered highly tolerogenic by interferon-γ (IFN-γ), which activates the enzyme indoleamine 2,3-dioxygenase (IDO, encoded by Indo) and thus initiates the immunosuppressive pathway of tryptophan catabolism. By examining the expression of a series of relevant genes in IDO+ compared with IDO- DCs, we found consistent and selective association of the IDO-competent phenotype with down-modulation of the Tyrobp gene, encoding the signaling adapter DAP12, which typically associates with activating receptors. Down-modulation of Tyrobp involved IFN consensus sequence binding protein (ICSBP), a transcription factor also known as IRF-8. In murine and human monocyte-derived DCs, silencing DAP12 expression imparted IDO functional competence to IDO- cells, whereas silencing IRF-8 in IDO+ counterparts abolished IDO expression and function. Thus, IRF-8 is required in tolerogenic DCs for the positive regulation of Indo and the negative regulation of Tyrobp. Overall, these studies reveal the occurrence of a simple and evolutionarily conserved code in the control of tolerance by an ancestral metabolic enzyme.
The safety and efficacy of inhaled dry powder mannitol as a bronchial provocation test for airway hyperresponsiveness: a phase 3 comparison study with hypertonic (4.5%) saline
Authors: Brannan John D , Anderson Sandra D , Perry Clare P , Freed-Martens Ruth , Lassig Anna R , Charlton Brett ,   the Aridol Study Group
Published: December 2005

Background

Inhaled mannitol is a new bronchial provocation test (BPT) developed to improve portability and standardisation of osmotic challenge testing. Osmotic challenge tests have an advantage over the traditional methods of measuring airway hyperresponsiveness using methacholine as they demonstrate higher specificity to identify asthma and thus the need for treatment with inhaled corticosteroids (ICS). The safety and the efficacy of mannitol (M) as a BPT to measure airway hyperresponsiveness were compared to hypertonic (4.5%) saline (HS) in people both with and without signs and symptoms of asthma.

Methods

A phase III, multi-centre, open label, operator-blinded, crossover design, randomised trial, with follow-up. Asthmatics and non-asthmatics (6–83 yr) were recruited and 592 subjects completed the study. Mannitol was delivered using a low resistance dry powder inhaler and HS was delivered using an ultrasonic nebuliser. The FEV1was measured 60 seconds after each dose of mannitol (5,10,20,40,80,160,160,160 mg) and after each exposure to HS (0.5,1.0,2.0,4.0,8.0 minutes). A 15% fall in FEV1defined a positive test. Adverse events were monitored and diaries kept for 7 days following the tests.

Results

Mean pre-test FEV1 (mean ± SD) was 95.5 ± 14% predicted. 296 were positive to mannitol (M+) and 322 positive to HS (HS+). A post study physician conducted clinical assessment identified 82.3% asthmatic (44% classified mild) and 17.7% non-asthmatic. Of those M+, 70.1% were taking ICS and of those mannitol negative (M-), 81.1 % were taking ICS. The % fall in FEV1 for mannitol in asthmatics was 21.0% ± 5.7 and for the non-asthmatics, 5.5% ± 4.8. The median PD15 M was 148 mg and PD15 HS 6.2 ml. The sensitivity of M to identify HS+ was 80.7% and the specificity 86.7%. The sensitivity of M compared with the clinical assessment was 59.8% and specificity 95.2% and increased to 88.7% and 95.0% respectively when the M- subjects taking ICS were excluded. Cough was common during testing. There were no serious adverse events. The diarised events were similar for mannitol and HS, the most common being headache (17.2%M, 19%HS), pharyngolaryngeal pain (5.1%M, 3%HS), nausea (4.3%M, 3%HS), and cough (2.2%M, 2.4%HS).

Conclusion

The efficacy and safety of mannitol was demonstrated in non-asthmatic and clinically diagnosed asthmatic adults and children.
Liver Triglyceride Secretion and Lipid Oxidative Metabolism Are Rapidly Altered by Leptin in Vivo
Authors: Huang Wan , Dedousis Nikolas , Bandi Archana , Lopaschuk Gary D. , O’Doherty Robert M.
Published: December 2005

Leptin has potent lipid-lowering effects in peripheral tissues and plasma that are proposed to be important for the prevention of cellular lipotoxicity and insulin resistance. The current study addressed in vivo the effects of acute leptin delivery on liver triglyceride (TG) metabolism, the consequence of hepatic leptin action on whole-body TG homeostasis, and the mechanisms of leptin action. A 120-min iv leptin infusion (plasma leptin, ∼14 ng/ml) decreased liver TG levels (53 ± 3%; P = 0.001), but not skeletal muscle TG levels, and increased liver phosphatidylinositol 3-kinase activity (341 ± 95%; P = 0.01) in lean rats. Leptin had no effect on liver TG levels or phosphatidylinositol 3-kinase activity in diet-induced obese rats. In lean animals, leptin decreased the plasma TG concentration (20 ± 7%; P = 0.017), the rate of TG accumulation in plasma after tyloxapol administration (26 ± 6%; P = 0.003), and TG secretion from isolated liver (51 ± 8%; P = 0.004). To determine possible metabolic fates of depleted hepatic TG, we assessed leptin effects on liver oxidative metabolism. Leptin increased hepatic acetyl-coenzyme A carboxylase phosphorylation (85 ± 13%; P = 0.006), fatty acid oxidation (49 ± 7%; P = 0.001) and ketogenesis (69 ± 15%; P = 0.004). Finally, intracerebroventricular delivery of leptin for 120 min had no effect on liver TG levels, but did increase signal transducer and activator of transcription 3 phosphorylation (162 ± 40%; P = 0.02). These data present in vivo evidence for a role for leptin in the acute regulation of hepatic TG metabolism, and whole body TG homeostasis. A likely contributing mechanism for these effects is leptin-induced partitioning of TG into oxidative pathways.
Dominant Role of Sarcoendoplasmic Reticulum Ca2+-ATPase Pump in Ca2+ Homeostasis and Exocytosis in Rat Pancreatic β-Cells
Authors: Hughes Elizabeth , Lee Andy K. , Tse Amy
Published: December 2005

The exocytosis of insulin-containing granules from pancreatic β-cells is tightly regulated by changes in cytosolic Ca2+ concentration ([Ca2+]i). We investigated the role of the sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) pump, Na+/Ca2+ exchanger, and plasma membrane Ca2+-ATPase pump in the Ca2+ dynamics of single rat pancreatic β-cells. When the membrane potential was voltage clamped at −70 mV (in 3 mm glucose at ∼22 or 35 C), SERCA pump inhibition dramatically slowed (∼4-fold) cytosolic Ca2+ clearance and caused a sustained rise in basal [Ca2+]i via the activation of capacitative Ca2+ entry. SERCA pump inhibition increased (∼1.8-fold) the amplitude of the depolarization-triggered Ca2+ transient at approximately 22 C. Inhibition of the Na+/Ca2+ exchanger or plasma membrane Ca2+-ATPase pump had only minor effects on Ca2+ dynamics. Simultaneous measurement of [Ca2+]i and exocytosis (with capacitance measurement) revealed that SERCA pump inhibition increased the magnitude of depolarization-triggered exocytosis. This enhancement in exocytosis was not due to the slowing of the cytosolic Ca2+ clearance but was closely correlated to the increase in the peak of the depolarization-triggered Ca2+ transient. When compared at similar [Ca2+]i with controls, the rise in basal [Ca2+]i during SERCA pump inhibition did not cause any enhancement in the magnitude of the ensuing depolarization-triggered exocytosis. Therefore, we conclude that in rat pancreatic β-cells, the rapid uptake of Ca2+ by SERCA pump limits the peak amplitude of depolarization-triggered [Ca2+]i rise and thus controls the amount of insulin secretion.
Mechanisms of Ligand Binding to the Parathyroid Hormone (PTH)/PTH-Related Protein Receptor: Selectivity of a Modified PTH(1–15) Radioligand for GαS-Coupled Receptor Conformations
Authors: Dean Thomas , Linglart Agnes , Mahon Matthew J. , Bastepe Murat , Jüppner Harald , Potts John T. , Gardella Thomas J.
Published: December 2005

Mechanisms of ligand binding to the PTH/PTHrP receptor (PTHR) were explored using PTH fragment analogs as radioligands in binding assays. In particular, the modified amino-terminal fragment analog, 125I-[Aib1,3,Nle8,Gln 10,homoarginine11,Ala12,Trp14,Tyr15]rPTH(1–15)NH2, 125I-[Aib1,3,M]PTH(1–15), was used as a radioligand that we hypothesized to bind solely to the juxtamembrane (J) portion of the PTHR containing the extracellular loops and transmembrane helices. We also employed 125I-PTH(1–34) as a radioligand that binds to both the amino-terminal extracellular (N) and J domains of the PTHR. Binding was examined in membranes derived from cells expressing either wild-type or mutant PTHRs. We found that the binding of 125I-[Aib1,3,M]PTH(1–15) to the wild-type PTHR was strongly (∼90%) inhibited by guanosine 5′-O-(3-thio)triphosphate (GTPγS), whereas the binding of 125I-PTH(1–34) was only mildly (∼25%) inhibited by GTPγS. Of these two radioligands, only 125I-[Aib1,3,M]PTH(1–15) bound to PTHR-delNt, which lacks most of the receptor’s N domain, and again this binding was strongly inhibited by GTPγS. Binding of 125I-[Aib1,3,M]PTH(1–15) to the constitutively active receptor, PTHR-H223R, was only mildly (∼20%) inhibited by GTPγS, as was the binding of 125I-PTH(1–34). In membranes prepared from cells lacking GαS via knockout mutation of Gnas, no binding of 125I-[Aib1,3,M]PTH(1–15) was observed, but binding of 125I-[Aib1,3,M]PTH(1–15) was recovered by virally transducing the cells to heterologously express GαS. 125I-PTH(1–34) bound to the membranes with or without GαS. The overall findings confirm the hypothesis that 125I-[Aib1,3,M]PTH(1–15) binds solely to the J domain of the PTHR. They further show that this binding is strongly dependent on coupling of the receptor to GαS-containing heterotrimeric G proteins, whereas the binding of 125I-PTH(1–34) can occur in the absence of such coupling. Thus, 125I-[Aib1,3,M]PTH(1–15) appears to function as a selective probe of GαS-coupled, active-state PTHR conformations.
XCR2, one of threeXenopusEGF-CFC genes, has a distinct role in the regulation of left-right patterning
Authors: Onuma Yasuko , Yeo Chang-Yeol , Whitman Malcolm
Published: December 2005

Members of the EGF-CFC family facilitate signaling by a subset of TGFβsuperfamily ligands that includes the nodal-related factors and GDF1/VG1. Studies in mouse, zebrafish, and chick point to an essential role for EGF-CFC proteins in the action of nodal/GDF1 signals in the early establishment of the mesendoderm and later visceral left-right patterning. Antisense knockdown of the only known frog EGF-CFC factor (FRL1), however, has argued against an essential role for this factor in nodal/GDF1 signaling. To address this apparent paradox, we have identified two additional Xenopus EGF-CFC family members. The three Xenopus EGF-CFC factors show distinct patterns of expression. We have examined the role of XCR2, the only Xenopus EGF-CFC factor expressed in post-gastrula embryos, in embryogenesis. Antisense morpholino oligonucleotide-mediated depletion of XCR2 disrupts left-right asymmetry of the heart and gut. Although XCR2 is expressed bilaterally at neurula stage, XCR2 is required on the left side, but not the right side, for normal left-right patterning. Left-side expression of XNR1 in the lateral plate mesoderm depends on XCR2, whereas posterior bilateral expression of XNR1 does not, suggesting that distinct mechanisms maintain XNR1 expression in different regions of neurula-tailbud embryos. Ectopic XCR2 on the right side initiates premature right-side expression of XNR1 and XATV, and can reverse visceral patterning. This activity of XCR2 depends on its co-receptor function. These observations indicate that XCR2 has a crucial limiting role in maintaining a bistable asymmetry in nodal family signaling across the left-right axis.
TheAUXIN RESPONSE FACTOR 2gene ofArabidopsislinks auxin signalling, cell division, and the size of seeds and other organs
Authors: Schruff Marie C. , Spielman Melissa , Tiwari Sushma , Adams Sally , Fenby Nick , Scott Rod J.
Published: December 2005

Control of seed size involves complex interactions among the zygotic embryo and endosperm, the maternally derived seed coat, and the parent plant. Here we describe a mutant in Arabidopsis, megaintegumenta (mnt), in which seed size and weight are dramatically increased. One factor in this is extra cell division in the integuments surrounding mnt mutant ovules,leading to the formation of enlarged seed coats. Unusually for integument mutants, mnt does not impair female fertility. The mntlesion also has pleiotropic effects on vegetative and floral development,causing extra cell division and expansion in many organs. mnt was identified as a mutant allele of AUXIN RESPONSE FACTOR 2(ARF2), a member of a family of transcription factors that mediate gene expression in response to auxin. The mutant phenotype and gene expression studies described here provide evidence that MNT/ARF2 is a repressor of cell division and organ growth. The mutant phenotype also illustrates the importance of growth of the ovule before fertilization in determining final size of the seed.
Deglycosylation of Na+/K+-ATPase causes the basolateral protein to undergo apical targeting in polarized hepatic cells
Authors: Lian Wei-Nan , Wu Tzu-Wei , Dao Ro-Lan , Chen Yann-Jang , Lin Chi-Hung
Published: December 2005

Polarized epithelia, such as hepatocytes, target their integral membrane proteins to specific apical or basolateral membrane domains during or after biogenesis. The roles played by protein glycosylation in this sorting process remain controversial. We report here that deglycosylation treatments in well-polarized hepatic cells by deglycosylation drugs, or by site-directed mutagenesis of the N-linked-glycosylation residues, all cause the Na+/K+-ATPase β-subunit to traffic from the native basolateral to the apical/canalicular domain. Deglycosylated β-subunits are still able to bind and therefore transport the catalytic α-subunits to the aberrant apical location. Such apical targeting is mediated via the indirect transcytosis pathway. Cells containing apical Na+/K+-ATPase appear to be defective in maintaining the ionic gradient across the plasma membrane and in executing hepatic activities that are dependent upon the ionic homeostasis such as canalicular excretion.