bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular Ca2+Silences L-Type Ca2+Channels in Mesenteric Veins
Authors: Thakali Keshari M. , Kharade Sujay V. , Sonkusare Swapnil K. , Rhee Sung W. , Stimers Joseph R. , Rusch Nancy J. 
Published: January 2010

Rationale:Calcium channel blockers (CCBs) exert their antihypertensive effect by reducing cardiac afterload but not preload, suggesting that Ca2+influx through L-type Ca2+channels (LTCC) mediates arterial but not venous tone.Objective:The object of this study was to resolve the mechanism of venous resistance to CCBs.Methods and Results:We compared the sensitivity of depolarization (KCl)-induced constriction of rat small mesenteric arteries (MAs) and veins (MVs) to the dilator effect of CCBs. Initial findings confirmed that nifedipine progressively dilated depolarization-induced constrictions in MAs but not MVs. However, Western blots showed a similar expression of the α1Cpore-forming subunit of the LTCC in both vessels. Patch-clamp studies revealed a similar density of whole-cell Ca2+channel current between single smooth muscle cells (SMCs) of MAs and MVs. Based on these findings, we hypothesized that LTCCs are expressed but “silenced” by intracellular Ca2+in venous SMCs. After depletion of intracellular Ca2+stores by the SERCA pump inhibitor thapsigargin, depolarization-induced constrictions in MVs were blocked 80% by nifedipine suggesting restoration of Ca2+influx through LTCCs. Similarly, KCl-induced constrictions were sensitive to block by nifedipine after depletion of intracellular Ca2+stores by caffeine, ryanodine, or 2-aminoethoxydiphenyl borate. Cell-attached patch recordings of unitary LTCC currents confirmed rare channel openings during depolarization of venous compared to arterial SMCs, but chelating intracellular Ca2+significantly increased the open-state probability of venous LTCCs.Conclusions:We report that intracellular Ca2+inactivates LTCCs in venous SMCs to confer venous resistance to CCB-induced dilation, a fundamental drug property that was previously unexplained.
Caffeinol at the Receptor Level
Authors: Zhao Xiurong , Strong Roger , Piriyawat Paisith , Palusinski Robert , Grotta James C. , Aronowski Jaroslaw 
Published: January 2010

Background and Purpose—Although caffeinol (a combination of a low dose of caffeine and ethanol) was shown to robustly reduce stroke damage in experimental models and is now in clinical evaluation for treatment of ischemic stroke, little is known about the potential mechanism of its action.Methods—We used an in vivo excitotoxicity model based on intracortical infusion ofN-methyl-d-aspartate (NMDA) and a model of reversible focal ischemia to demonstrate NMDA receptor inhibition as a potential mechanism of caffeinol anti-ischemic activity.Results—Caffeinol reduced the size of excitotoxic lesion, and substitution of ethanol in caffeinol with the NMDA antagonists CNS-1102 and MK-801 but not with MgSO4produced treatment with strong synergistic effect that was at least as robust in reducing ischemic damage as caffeinol. This NMDA receptor antagonist and caffeine combination demonstrated a long window of opportunity, activity in spontaneously hypertensive rats, and, unlike caffeinol, was fully effective in animals chronically pretreated with ethanol.Conclusions—Our study suggests that antiexcitotoxic properties may underlie some of the anti-ischemic effect of caffeinol. This study provides strong evidence that the anti-ischemic effect of NMDA receptor blockers in general can be dramatically augmented by caffeine, thus opening a possibility for new use of NMDA-based pharmacology in the treatment of stroke.
Strategies Used by Intellectually Gifted Students to Cope With Stress During Their Participation in a High School International Baccalaureate Program
Authors: Shaunessy Elizabeth , Suldo Shannon M. 
Published: December 2009

Individuals respond to threats to affiliation and achievement needs through drawing on a repertoire of coping strategies specific to a given situation. Gifted adolescents in college-preparatory high school programs may be faced with novel stressors, and may have unique coping strategies to manage these challenges. The current study considers responses to surveys of stress and coping as well as focus group interviews of gifted and high-achieving students enrolled in an academically intense curriculum, the International Baccalaureate (IB) Diploma Program. Findings of this secondary analysis of archival data sets indicate gifted students experience levels of stress similar to their IB classmates not identified as gifted. Additionally, gifted students were similar to IB peers not identified as gifted with respect to how they cope with school; likenesses included positive reframing, time and task management, avoiding tasks, and seeking social support. However, gifted IB students differed from IB classmates with respect to anger coping, humor, and problem-solving approaches. Putting the Research to Use With the growing interest of International Baccalaureate Programs throughout the United States, educational personnel, researchers, and administrators are considering the social-emotional needs of gifted and high-ability students served in these challenging academic programs. Understanding the needs of this unique population of students is critical to supporting the cognitive and affective growth of IB students, and this study provides a glimpse into the thoughts of IB learners with respect to their stress and coping.The findings of this study suggests that gifted students in IB and their IB peers experience similar stressors and coping responses, though some differences in anger coping, humor, and problem solving were unique among gifted IB students in this sample.
Vision Is Precious
Authors: Jones Hollie L. , Walker Elizabeth A. , Schechter Clyde B. , Blanco Emelinda 
Published: January 2010

Purpose This purpose of this report is to describe a successful telephone intervention to increase the rate of diabetic retinopathy screening, its implementation with English and Spanish speakers, and the characteristics of those who benefited most from the intervention. Methods Participants in the telephone group (N = 305) received a tailored intervention from trained health educators who were ethnically diverse and representative of the community. The main outcome for the randomized controlled study was documented receipt of a dilated fundus examination (DFE) within the 6-month study window. Exploratory analyses focused on examining the factors that contribute to receiving a DFE within 6 months for participants in the tailored telephone intervention using Pearson χ2 and logistic regression analysis. Results Participants in the telephone intervention who did not receive a DFE had significantly more documented steps in the behavioral process than those who did receive a DFE, and ethnic concordance of the health educator was not significantly associated with a positive outcome in the DFE group. There was a negative association between the time spent building rapport and receipt of DFE. As time spent engaging in educational activities by telephone increased, the likelihood of receiving a DFE increased. Conclusions Although the telephone intervention was highly successful compared with the print intervention, these process results demonstrate the difficulties and challenges of conducting a tailored telephone intervention to improve rates of screening in an underserved, diverse urban community.
Patellar Height and Posterior Tibial Slope after Open- and Closed-Wedge High Tibial Osteotomy
Authors: El-Azab Hosam , Glabgly Parpakorn , Paul Jochen , Imhoff Andreas B. , Hinterwimmer Stefan 
Published: January 2010

Background Valgus high tibial osteotomy (HTO) may be associated with changes in the patellar height and posterior tibial slope. Hypothesis Patellar height increases and posterior tibial slope decreases after closed-wedge HTO, whereas patellar height decreases and tibial slope increases after open-wedge osteotomy. Study Design Cohort study; Level of evidence, 3. Methods Lateral radiographs of 100 knees were assessed for patellar height (PH) (Insall-Salvati index [ISI], Caton-De Champ index [CDI], and Blackburne-Peel index [BPI]) as well as posterior tibial slope. Measurements were done before HTO (50 closed wedge [CW], 50 open wedge [OW]), direct postoperatively, and before removal of the hardware. Results In the CW group, all 3 PH indices were increased direct postoperatively and at removal of the hardware, with changes in CDI and BPI being significant (P < .05). The effect size (ES) for the direct postoperative PH increase was medium (ES = 0.48) according to CDI. In the OW group, all 3 indices showed a significant (P < .05) PH decrease direct postoperatively and at hardware removal. The ES for the direct postoperative PH decrease was large according to CDI (ES = 0.92) and BPI (ES = 0.80). There were no significant changes between the 2 follow-up measurements (P > .05) with a small ES each. Posterior tibial slope showed a significant (P < .05) decrease of 3.1° ± 3.4° after CW HTO and a significant (P < .05) increase of 2.1° ± 3.6° after OW HTO direct postoperatively. These changes did not change at the second follow-up. In CW HTO, the correlations between frontal plane correction and PH changes were moderate (CDI: r = .57; BPI: r = .64). In OW HTO, these correlations were weak (CDI: r = .44; BPI: r = .46). According to ISI, there was no correlation (CW: r = .11; OW: r = .16). There was no correlation between PH changes and slope changes (CDI) and no correlation between frontal plane HTO correction and slope changes in both CW and OW HTO. Conclusion The results confirm our hypothesis for PH and posterior tibial slope changes after valgus HTO. However, there is no strong correlation between PH changes and the degree of frontal plane HTO correction. The incidence of patella infera increases after OW HTO, whereas the incidence of patella alta increases after CW HTO. Therefore, we recommend performing CW HTO or OW HTO with the tuberosity left at the proximal tibia in cases of patellofemoral complaints or patella infera. Neither technique leads to patellar lowering. It should be borne in mind that PH and posterior tibial slope may have been altered before planning total knee replacement after HTO.
Pelvic Fractures Resulting from Snowboarding
Authors: Ogawa Hiroyasu , Sumi Hiroshi , Sumi Yasuhiko , Shimizu Katsuji 
Published: January 2010

Background Information regarding pelvic fractures sustained during snowboarding is scant. Purpose To analyze the epidemiologic data, injury patterns, and types of pelvic fractures sustained during snowboarding. Study Deign Case series; Level of evidence, 4. Methods We analyzed the epidemiologic factors, injury patterns, and types of pelvic fractures in 145 patients with snowboarding-related pelvic fractures who were admitted to our institution from the 1998-1999 to the 2006-2007 ski season. Results The incidence of snowboarding-related pelvic fractures was 0.102 per 10 000 ski lift tickets, which amounted to 2% of all snowboarding-related fractures (fifth most common type of fracture among all snowboarding-related fractures). Of the pelvic fractures, 85.5% were stable (type A according to the Tile classification) and 14.5% were unstable (types B and C according to the Tile classification). Isolated sacral fractures had the second-highest incidence (24.1%) after pubic bone and/or ischium fractures (46.9%). A distinct female prevalence was seen (52.4%). Jumps and isolated falls were the main mechanisms of injury (80%), and the incidence of collision was significantly higher in the unstable group than in the stable group (P = .037). In all, 57.9% patients classified their skill level as “intermediate,” and only 9.7% of patients had received professional snowboarding lessons. A total of 30 subjects (20.8%) had other injuries along with pelvic fractures; the patients with multiple injuries were significantly more frequent in the unstable group than in the stable group (P = .035). Conclusion Pelvic fractures resulting from snowboarding accidents included a higher proportion with isolated sacral fractures in the stable group and a lower prevalence of associated injuries in the unstable group compared with those resulting from other causes.
In Situ Forces in the Anteromedial and Posterolateral Bundles of the Anterior Cruciate Ligament under Simulated Functional Loading Conditions
Authors: Wu Jia-Lin , Seon Jong Keun , Gadikota Hemanth R. , Hosseini Ali , Sutton Karen M. , Gill Thomas J. , Li Guoan 
Published: January 2010

Background The in situ forces of the anteromedial (AM) and posterolateral bundles (PL) of the anterior cruciate ligament (ACL) under simulated functional loads such as simulated muscle loads have not been reported. These data are instrumental for improvement of the anatomical double-bundle ACL reconstruction. Hypothesis The load-sharing patterns of the 2 bundles are complementary under simulated muscle loads. Study Design Descriptive laboratory study. Methods Eight cadaveric knees in this study were sequentially studied using a robotic testing system. Each knee was tested under 3 external loading conditions including (1) a 134-N anterior tibial load; (2) combined rotational loads of 10 N·m of valgus and 5 N·m internal tibial torques; and (3) a 400-N quadriceps muscle load with the knee at 0°, 15°, 30°, 60°, and 90° of flexion. The in situ forces of the 2 bundles of ACL were determined using the principle of superposition. Results Under the anterior tibial load, the PL bundle carried peak loads at full extension and concurrently had significantly lower force than the AM bundle throughout the range of flexion (P < .05). Under the combined rotational loads, the PL bundle contributed to carrying the load between 0° and 30°, although less than the AM bundle. Under simulated muscle loads, both bundles carried loads between 0° and 30°. There was no significant difference between the 2 bundle forces at all flexion angles (P > .05). Conclusion Under externally applied loads, in general, the AM bundle carried a greater portion of the load at all flexion angles, whereas the PL bundle only shared the load at low flexion angles. The bundles functioned in a complementary rather than a reciprocal manner to each other. Clinical Relevance The data appear to support the concept that both bundles function in a complementary manner. Thus, how to re-create the 2 bundle functions in an ACL reconstruction should be further investigated.
Biodegradable Screw versus a Press-Fit Bone Plug Fixation for Hamstring Anterior Cruciate Ligament Reconstruction
Authors: Jagodzinski Michael , Geiges Bjoern , von Falck Christian , Knobloch Karsten , Haasper Carl , Brand Juergen , Hankemeier Stefan , Krettek Christian , Meller Rupert 
Published: January 2010

Background Press-fit fixation of a tendon graft has been advocated to achieve tendon-to-bone healing. Hypothesis Fixation of hamstring tendon grafts with a porous bone scaffold limits bone tunnel enlargement compared with a biodegradable interference screw fixation. Study Design Randomized controlled trial; Level of evidence, 1. Methods Between 2005 and 2006, 20 patients (17 men, 3 women) with a primary reconstruction of the anterior cruciate ligament (ACL) were enrolled in this study. Patients were randomized to obtain graft fixation in the tibial tunnel either by means of an interference screw (I) or a press-fit fixation with a porous bone cylinder (P). At 3 months after surgery, a computed tomography (CT) scan of the knee was performed, and tunnel enlargement was analyzed in the coronal and sagittal planes for the proximal, middle, and distal thirds of the tunnel. After 6 months and 1 and 2 years, radiographs of the knee in the sagittal and coronal plane were analyzed for bone tunnel widening. The International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores of both groups were compared after 1 and 2 years. Results The bone tunnel enlargement determined by CT was 106.9% ± 10.9% for group P and 121.9% ± 9.0% for group I (P < .02) in the anteroposterior (AP) plane and 102.8% ± 15.2% versus 121.5% ± 10.1% in the coronal plane (P < .01). The IKDC, Tegner, and Lysholm scores improved in both groups from preoperatively to postoperatively without significant differences between the 2 groups. There was a trend to higher knee stability in group P after 3 months (0.6 ± 1.4 mm vs 1.8 ± 1.5 mm; P = .08). Conclusion Both interference screw and a press-fit fixation lead to a high number of good or very good outcomes after ACL reconstruction. Tibial press-fit fixation decreases the amount of proximal bone tunnel enlargement.
Novel Approach to Repair of Acute Achilles Tendon Rupture
Authors: Yotsumoto Tadahiko , Miyamoto Wataru , Uchio Yuji 
Published: January 2010

Background Immobilization or orthosis is required after conventional Achilles tendon surgery. Hypothesis This new Achilles tendon repair approach enables early rehabilitation without any postoperative immobilization or orthosis. Study Design Case series; Level of evidence, 4. Methods Twenty consecutive patients (14 men and 6 women; mean age, 43.4 years; range, 16-70 years) who had acute subcutaneous Achilles tendon rupture were treated by the new method, with an average follow-up of 2.9 years (range, 2-4.8 years). Among them, 15 injuries were sports-related and 5 were work-related. The authors applied a side-locking loop technique of their own design for the core suture, using braided polyblend suture thread, with peripheral cross-stitches added. The patients started active and passive ankle mobilization from the next day, partial weightbearing walking from 1 week, full-load walking from 4 weeks, and double-legged heel raises from 6 weeks after surgery. Results The range of motion recovery equal to the intact side averaged 3.2 weeks. Double-legged heel raises and 20 continuous singlelegged heel raise exercises were possible at an average of 6.3 weeks and 9.9 weeks, respectively. T2-weighted magnetic resonance signal intensity recovered to equal that of the intact portion of the same tendon at 12 weeks. The patients resumed sports activities or heavy labor at an average of 14.4 weeks. The Achilles tendon rupture score averaged 98.3 at 24 weeks. There were no complications. Conclusion This new Achilles tendon repair approach enables early mobilization exercise without costly specialized orthosis or immobilization and allows an early return to normal life and sports activities, reducing the physical and economic burden on patients.
Focal Cartilage Defects in the Knee Impair Quality of Life as Much as Severe Osteoarthritis
Authors: Heir Stig , Nerhus Tor K. , Røtterud Jan H. , Løken Sverre , Ekeland Arne , Engebretsen Lars , Årøen Asbjørn 
Published: December 2009

Background Patients with focal cartilage defects in the knee may suffer from both pain and functional impairment. Treatment options are often insufficient. It is not known, however, to what extent their complaints affect quality of life, compared with other knee disorders. Knee Injury and Osteoarthritis Outcome Score (KOOS) is a validated global knee score suitable for comparison of patients with knee complaints attributable to different causes. Hypothesis Complaints because of localized cartilage defects in the knee reduce quality of life measured by KOOS to a different extent than those due to anterior cruciate ligament deficiency and osteoarthritis, when comparing patients within the working population scheduled for surgery. Study Design Cross-sectional study; Level of evidence, 3. Methods Previously registered KOOS baseline data on patients enrolled in different knee treatment studies were included in the present study; the patients were 18 to 67 years of age (working population) at data registration. The different patient categories were (1) patients with knee osteoarthritis enrolled for knee arthroplasty, (2) patients with knee osteoarthritis enrolled for osteotomies around the knee, (3) patients with focal cartilage lesions enrolled for cartilage repair, and (4) patients with anterior cruciate ligament—deficient knees enrolled for anterior cruciate ligament reconstruction. The KOOS subscale quality of life was the main parameter for comparison of complaints. Results At preoperative baseline, patients with focal cartilage defects in the knee scored 27.5 on the KOOS subscale quality of life, not significantly different from the 28.8 and 27.2 in the patients with osteoarthritis enrolled for knee osteotomies and arthroplasties, respectively. For all the subscales of KOOS, the cartilage patients scored significantly lower than the patients with anterior cruciate ligament deficiency. Conclusion Patients with focal cartilage lesions have major problems with pain and functional impairment. Their complaints are worse than those of patients with anterior cruciate ligament—deficient knees, and quality of life is affected to the same extent as in patients scheduled for knee replacement.
Design and Dynamic Culture of 3D-Scaffolds for Cartilage Tissue Engineering
Authors: El-Ayoubi Rouwayda , DeGrandpré Christian , DiRaddo Robert , Yousefi Azizeh-Mitra , Lavigne Patrick 
Published: December 2009

Engineered scaffolds for tissue-engineering should be designed to match the stiffness and strength of healthy tissues while maintaining an interconnected pore network and a reasonable porosity. In this work, we have used 3D-plotting technique to produce poly-L-Lactide macroporous scaffolds with two different pore sizes. The ability of these macroporous scaffolds to support chondrocyte attachment and viability were compared under static and dynamic loading in vitro. Moreover, the 3D-plotting technique was combined with porogen-leaching, leading to macro/microporous scaffolds, so as to examine the effect of microporosity on the level of cell attachment and viability under similar loading condition. Canine chondrocytes’ cells were seeded onto the scaffolds with different topologies, and the constructs were cultured for up to 2 weeks under static conditions or in a bioreactor under dynamic compressive strain of 10% strain, at a frequency of 1 Hz. The attachment and cell growth of chondrocytes were examined by scanning electron microscopy and by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. A significant difference in cell attachment was observed in macroporous scaffolds with different pore sizes after 1, 7, and 14 days. Cell viability in the scaffolds was enhanced with decreasing pore size and increasing microporosity level throughout the culture period. Chondrocyte viability in the scaffolds cultured under dynamic loading was significantly higher (p<0.05) than the scaffolds cultured statically. Dynamic cell culture of the scaffolds improved cell viability and decreased the time of in vitro culture when compared to statically cultured constructs. Optimizing the culture conditions and scaffold properties could generate optimal tissue/constructs combination for cartilage repair.