bluuebunny/crossref_metadata_2025_split huggingface dataset:
The knee adduction moment during gait in subjects with knee osteoarthritis is more closely correlated with static alignment than radiographic disease severity, toe out angle and pain
Authors: Hurwitz D. E. , Ryals A. B. , Case J. P. , Block J. A. , Andriacchi T. P. 
Published: October 2002

AbstractThis study tested whether the peak external knee adduction moments during walking in subjects with knee osteoarthritis (OA) were correlated with the mechanical axis of the leg, radiographic measures of OA severity, toe out angle or clinical assessments of pain, stiffness or function. Gait analysis was performed on 62 subjects with knee OA and 49 asymptomatic control subjects (normal subjects). The subjects with OA walked with a greater than normal peak adduction moment during early stance (p = 0.027). In the OA group, the mechanical axis was the best single predictor of the peak adduction moment during both early and late stance (R = 0.74, p < 0.001). The radiographic measures of OA severity in the medial compartment were also predictive of both peak adduction moments (R = 0.43 to 0.48, p < 0.001) along with the sum of the WOMAC subscales (R = −0.33 to −0.31, p < 0.017). The toe out angle was predictive of the peak adduction moment only during late stance (R = −0.45, p < 0.001). Once mechanical axis was accounted for, other factors only increased the ability to predict the peak knee adduction moments by 10–18%. While the mechanical axis was indicative of the peak adduction moments, it only accounted for about 50% of its variation, emphasizing the need for a dynamic evaluation of the knee joint loading environment. Understanding which clinical measures of OA are most closely associated with the dynamic knee joint loads may ultimately result in a better understanding of the disease process and the development of therapeutic interventions. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Age‐related variations in the microstructure of human tibial cancellous bone
Authors: Ding Ming , Odgaard Anders , Linde Frank , Hvid Ivan 
Published: October 2002

AbstractA thorough understanding of the microstructure of cancellous bone is crucial for diagnosis, prophylaxis, and treatment of age‐related skeletal diseases. Until now, little has been known about age‐related variations in the microstructure of peripheral cancellous bone. This study quantified age‐related changes in the three‐dimensional (3D) microstructure of human tibial cancellous bone. One hundred and sixty cylindrical cancellous bone specimens were produced from 40 normal proximal tibiae from 40 donors, aged 16–85 years. These specimens were micro‐computed tomography (micro‐CT) scanned, and microstructural properties were determined. The specimens were then tested in compression to obtain Young's modulus.The degree of anisotropy, mean marrow space volume, and bone surface‐to‐volume ratio increased significantly with age. Bone volume fraction, mean trabecular volume, and bone surface density decreased significantly with age. Connectivity did not have a general relationship with age. Bone volume fraction together with anisotropy best predicted Young's modulus. Age‐related changes in the microstructural properties had the same trends for both medial and lateral condyles of the tibia. The observed increase of anisotropy and constant connectivity suggest a bone remodeling mechanism that may reorient trabecular volume orientation in aging tibial cancellous bone. The aging trabeculae align more strongly to the primary direction ‐ parallel to the tibial longitudinal loading axis. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Static and dynamic compression modulate matrix metabolism in tissue engineered cartilage
Authors: Davisson Twana , Kunig Sabine , Chen Albert , Sah Robert , Ratcliffe Anthony 
Published: October 2002

AbstractStatic and dynamic compression are known to modulate the metabolism of articular cartilage. The present study focused on determining the effects of compressive loading on the metabolism of sulfated glycosaminoglycans (S‐GAG) and protein in tissue engineered cartilage constructs. Cartilage constructs were subjected to static or dynamic compression for 24 h and radiolabeled with 35SO4 and 3H‐proline to assess the total synthesis and percentage retention of S‐GAG and total protein, respectively. Static compression at an amplitude of 50% suppressed the synthesis of both S‐GAG and protein by 35% and 57%, respectively. Dynamic compression at an amplitude of 5% had stimulatory effects on synthesis that were dependent on the static offset compression amplitude (10% or 50%) and dynamic compression frequency (0.001 or 0.1 Hz). Thus, tissue engineered cartilage demonstrated the ability to respond to mechanical loading in a manner similar to that observed with articular cartilage. Mechanical loading may therefore potentially be used to modulate the growth of cartilaginous tissues in vitro, potentially facilitating the culture of functional cartilage tissues suitable for implantation. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
In vivo study of hot compressing molded 50:50 poly (DL‐lactide‐co‐glycolide) antibiotic beads in rabbits
Authors: Ueng Steve W. N. , Yuan Li‐Jen , Lee Ning , Lin Song‐Shu , Liu Shih‐Jung , Chan Err‐Cheng , Weng Jui‐Hsun 
Published: October 2002

AbstractThe authors investigated poly (DL‐lactide‐co‐glycolide) beads as an antibiotic delivery system in vivo for the treatment of various surgical infections. In this study, the copolymer 50:50 poly (DL‐lactide):co‐glycolide was mixed with vancomycin powder and hot compressing molded at 55°C to form 8 mm in diameter biodegradable antibiotic beads. The antibiotic beads were implanted in the distal femoral cavities of rabbits for in vivo investigation. The local concentration of vancomycin was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for 56 days. The release was most marked during the first day. The diameters of the sample inhibition zone ranged from 8 to 18 mm, and the relative activity of vancomycin ranged from 9.1% to 100%. Only low systemic blood levels of vancomycin were measured after beads implantation. There was no increase in the concentration of blood urea nitrogen and serum creatinine after the implantation. Histological observations showed that the bead materials were biodegradable, resorbed slowly, and did not cause a significant host reaction. This study offers a biodegradable delivery system of antibiotics to treat various surgical infections. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Mechanical loads at the knee joint during deep flexion
Authors: Nagura Takeo , Dyrby Chris O. , Alexander Eugene J. , Andriacchi Thomas P. 
Published: October 2002

AbstractThere is a lack of fundamental information on the knee biomechanics in deep flexion beyond 90°. In this study, mechanical loads during activities requiring deep flexion were quantified on normal knees from 19 subjects, and compared with those in walking and stair climbing. The deep flexion activities generate larger net quadriceps moments (6.9–13.5% body weight into height) and net posterior forces (58.3–67.8% body weight) than routine ambulatory activities. Moreover, the peak net moments and the net posterior forces were generated between 90° and 150° of flexion.The large moments and forces will result in high stress at high angles of flexion. These loads can influence pathological changes to the joint and are important considerations for reconstructive procedures of the knee. The posterior cruciate ligament should have a substantial role during deep flexion, since there was a large posterior load that must be sustained at the knee. The mechanics of the knee in deep flexion are likely a factor causing problems of posterior instability in current total knee arthroplasty. Thus, it is important to consider the magnitude of the loads at the knee in the treatment of patients that commonly perform deep flexion during activities of daily living. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The effect of low intensity pulsed ultrasound applied to rabbit tibiae during the consolidation phase of distraction osteogenesis
Authors: Tis John E. , Meffert Rainer H. , Inoue Nozomu , McCarthy Edward F. , Shaun Machen M. , McHale Kathleen A. , Chao Edmund Y. S. 
Published: October 2002

AbstractThe purpose of this study was to determine if low intensity pulsed ultrasound (LIPU) accelerated the maturation of regenerate bone when applied after distraction in a rabbit model. A mid‐tibial osteotomy was performed in 26 New Zealand white rabbits and an external fixator applied anteromedially. After a seven day latency period, the tibiae were distracted 0.5 mm every 12 h for 10 days. Thirteen of the rabbits received LIPU for 20 min/day (treatment group) and 13 received sham LIPU (control group) from day 17 until sacrifice on day 37. Radiographs were taken weekly after distraction and the total and mineralized areas of the callus were measured. After sacrifice, dual‐energy X‐ray absorptiometry, torsional testing to failure, and histomorphometry were performed. Ultrasound‐treated tibiae were a mean of 68.8 ± 3.8% as stiff as and 68.2 ± 6.0% as strong as the contralateral tibiae. Control tibiae were 78.7 ± 7.0% as stiff as and 70.2 ± 7.9% as strong as the contralateral tibiae. The differences in stiffness and strength were not significant (p = 0.39 and 0.81, respectively) with the number of the animals tested in the study. The treatment group was 91.6% as dense as the contralateral side and the control group was 88.5% as dense as the contralateral side (p = 0.84). Radiographs revealed a significantly larger callus in the LIPU‐treated tibiae at 1, 2 and 3 weeks after distraction compared to control tibiae (p < 0.01, 0.008 and 0.05, respectively). Histomorphometry revealed significantly less fibrous tissue in the LIPU‐treated tibiae (p < 0.05) and a strong trend towards more bone in the LIPU‐treated tibiae compared to controls (p = 0.06). LIPU was found to increase the size of the distraction callus and it might alter the composition of regenerate bone but it did not have a positive effect on the mechanical properties or density of regenerate bone when applied during the consolidation phase of distraction osteogenesis. Published by Elsevier Science Ltd. on behalf of Orthopaedic Research Society. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Nestin expression persists in astrocytes of organotypic slice cultures from rat cortex
Authors: Schmidt‐Kastner Rainald , Humpel Christian 
Published: October 2002

AbstractNestin is an intermediate filament protein typical for neural precursor cells that is down‐regulated in the post‐natal rodent brain. Re‐expression of nestin has been observed in reactive astrocytes after injury. In this study, organotypic slice cultures from rat cortex were examined for expression of nestin and glial fibrillary acidic protein between 2 and 8 weeks in culture. Immunoreactivity for nestin and glial fibrillary acidic protein was seen in astrocytes which persisted throughout the observation period. Immunofluorescence double labeling showed widespread co‐localization of nestin and glial fibrillary acidic protein. Image analysis revealed that levels of nestin‐immunoreactivity plateaued after 5 weeks in culture. By comparison nestin immunoreactivity was absent from glial cells of the cortex in mature rats. These immunohistochemical findings of a persistent expression of nestin in glial cells of organotypic slice culture of the rat cortex indicate a different time course of glial maturation in vitro. This difference could be related to the altered trophic stimulation in vitro; differences in neuronal maturation, activity or survival; slow degeneration of the vasculature; or intrinsic properties of astrocytes.
Echocardiographic prediction of long‐term response to biventricular pacemaker in severe heart failure
Authors: Oguz Enis , Dagdeviren Bahadir , Bilsel Tuba , Akdemir Osman , Erdinler Izzet , Akyol Ahmet , Ulufer Tanju , Tezel Tuna , Gurkan Kadir 
Published: October 2002

AbstractBackground:Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy.Aims:To assess whether the long‐term benefit could be predicted from the echocardiographic parameters.Methods and Results:Sixteen patients with dilated cardiomyopathy who underwent atrio‐biventricular pacemaker implantation were analyzed in two groups: the responders (n‐11) were those with a symptomatic improvement of one or more NYHA functional class; the non‐responders (n‐5) failed to improve at follow‐up (7.6±5 months). Echocardiography was performed at baseline, the day after the implantation and then every 3 months. Besides the conventional parameters, the following variables were included: LV diastolic filling time (DFT); the duration of mitral regurgitation (dMR); and LV dP/dt obtained from the continuous wave mitral regurgitation curve. While the baseline DFT and dP/dt were not significantly different between non‐responders and responders (256±105 vs. 358±115, P‐0.14 and 564±199 vs. 468±117, P‐0.44, respectively), the QRS width (149±15 vs. 175±24 ms, P‐0.05) and the dMR (343±70 vs. 443±49 ms, P‐0.007) were higher in the responders. The changes of dMR, DFT and QRS width by pacing were not significantly different between groups (P‐0.18, 0.30 and 0.77, respectively). However, the change of LV dP/dt by pacing in the responders was significantly different than for non‐responders (from 468±117 to 676±216 mmHg/s vs. from 564±199 to 483±94, P‐0.002). An acute increase in LV dP/dt over 22% by pacing yielded only two false negatives and no false positives in predicting the long‐term responsiveness.Conclusion:Patients with longer QRS and dMR are more likely to benefit from atrio‐biventricular stimulation. The acute changes of Doppler derived LV dP/dt may provide valuable information in predicting the long‐term response to biventricular pacing.
Hypomagnesemia and concurrent acid–base and electrolyte abnormalities in patients with congestive heart failure
Authors: Milionis Haralampos J. , Alexandrides George E. , Liberopoulos Evangelos N. , Bairaktari Eleni T. , Goudevenos John , Elisaf Moses S. 
Published: October 2002

AbstractBackground:Patients with severe decompensated congestive heart failure (CHF) commonly exhibit acid–base and electrolyte disturbances mainly due to the activation of several neurohumoral mechanisms as well as to drugs regularly used in this population. Magnesium deficit is not infrequently observed in CHF patients but its pathophysiology remains less well‐studied as compared with other electrolyte alterations, such as hypokalemia. However, there is evidence that early detection and correction of magnesium abnormalities could obviate potentially deleterious arrhythmogenic effects.Aim:To assess the incidence of magnesium level disorders and analyze the underlying pathophysiological mechanisms in patients with CHF.Methods:Eighty‐six consecutive CHF patients (NYHA class III or IV) admitted to our hospital over a period of 5 years were studied. Patients with diabetes mellitus, liver or renal failure, and chronic obstructive lung disease were excluded. All patients received conventional treatment with digoxin, diuretic agents and an angiotensin converting enzyme inhibitor. On admission, blood and urine electrolytes and renal function parameters were determined. Arterial blood gases and serum anion gap determinations were also performed.Results:Hypomagnesemia was found in 15 [n ‐ 15 (17.4%)] CHF patients. The majority of these patients also exhibited other electrolyte abnormalities, such as hypokalemia, hypocalcemia and hypophosphatemia. Inappropriate magnesiuria (fractional excretion of magnesium >4%) was evident in eight hypomagnesemic patients. A variety of associated conditions, including poor dietary intake, also favored magnesium depletion.Conclusion:Magnesium deficit is a common electrolyte disorder in CHF (NYHA class III/IV) patients and several interrelated mechanisms are implicated in its pathogenesis. Clinicians’ awareness of the incidence of hypomagnesemia in this population as well as its related pathophysiology could be useful for the early detection and appropriate treatment to inhibit its arrhythmogenic potential.
The Associated Reaction Rating Scale: a clinical tool to measure associated reactions in the hemiplegic upper limb
Authors: Macfarlane Anne , Turner-Stokes Lynne , De Souza Lorraine 
Published: October 2002

Objective: To determine what items should be included in a clinical assessment tool developed to measure associated reactions in the hemiplegic upper limb and to assess the reliability of the resultant measure. Design: Development through a structured consultative process using focus group methodology. Evaluation of inter- and intra-rater reliability between two independent observers. Subjects: Nineteen consecutive hemiplegic patients admitted to Northwick Park Hospital for rehabilitation following stroke. Methods: Focus groups were conducted in two centres, comprising physiotherapists experienced in the clinical management of brain injury. The groups identified four key characteristics related to severity of associated reactions, which became the items of the rating scale. Evaluation of inter- and intra-rater reliability was undertaken by comparison of agreement between ratings of associated reactions occurring during a single standardized task (sit-to-stand), by two senior physiotherapists in 19 subjects. Results: There were good correlations between the two raters in total (rho 0.89 p< 0.005) and modal scores (rho 0.88 p < 0.005). Reliability testing of each item revealed moderate to very good inter-rater agreement (weighted kappa values 0.43–0.85) and good to very good intra-rater agreement (weighted kappa values 0.61–0.87). A slight tendency for one rater to score more severely than the other only reached significance for one item (excursion). Overall (modal) severity scores showed a good level of agreement (kappa 0.76–0.81) both between and within raters. Conclusion: Items to be included in a clinical assessment tool to measure associated reactions in the hemiplegic upper limb were determined. Reliability of the resultant measure was found to be encouraging. These results however apply only to observations made during a specific standardized task (sitto-stand) and further study of sensitivity to change and reproducibility in different tasks is required before the findings can be extrapolated into routine practice.
Does four weeks of TENS and/or isometric exercise produce cumulative reduction of osteoarthritic knee pain?
Authors: Cheing Gladys LY , Hui-Chan Christina WY , Chan K M 
Published: October 2002

Objective: To evaluate the cumulative effect of repeated transcutaneous electrical nerve stimulation (TENS) on chronic osteoarthritic (OA) knee pain over a four-week treatment period, comparing it to that of placebo stimulation and exercise training given alone or in combination with TENS. Design: Sixty-two patients, aged 50–75, were stratified according to age, gender and body mass ratio before being randomly assigned to four groups. Interventions: Patients received either (1) 60 minutes of TENS, (2) 60 minutes of placebo stimulation, (3) isometric exercise training, or (4) TENS and exercise (TENS & Ex) five days a week for four weeks. Main outcome measures: Visual analogue scale (VAS) was used to measure knee pain intensity before and after each treatment session over a four-week period, and at the four-week follow-up session. Results: Repeated measures ANOVA showed a significant cumulative reduction in the VAS scores across the four treatment sessions (session 1, 10, 20 and the follow-up) in the TENS group (45.9% by session 20, p < 0.001) and the placebo group (43.3% by session 20, p = 0.034). However, linear regression of the daily recordings of the VAS indicated that the slope in the TENS group (slope = -2.415, r = 0.943) was similar to the exercise group (slope = -2.625, r = 0.935), which were steeper than the other two groups. Note that the reduction of OA knee pain was maintained in the TENS group and the TENS & Ex group at the four-week follow-up session, but not in the other two groups. Conclusions: The four treatment protocols did not show significant between-group difference over the study period. It was interesting to note that isometric exercise training of the quadriceps alone also reduced knee pain towards the end of the treatment period.
Maximal isometric muscle strength of the cervical spine in healthy volunteers
Authors: Chiu Thomas TW , Lam Tai-Hing , Hedley Anthony J 
Published: October 2002

Objective: To describe the maximal isometric neck muscle strength in healthy Chinese volunteers, in six different directions, as measured by a Multi Cervical Rehabilitation Unit. Design: A standardized cross-sectional observational study. Setting: A university rehabilitation unit. Subjects: Ninety-one healthy volunteers aged 20–84. Methods: During the measurement the subject was instructed to do three consecutive steady contractions as hard as possible, with a 10-second rest in between each contraction and a 2-minute rest between different directions. The peak isometric strength for each of the six directions (‘exion, extension, lateral flexions, protraction and retraction) was calculated. Results: No significant difference was found in muscle strength between different age groups. Isometric muscle strength in the direction of right lateral flexion was significantly greater than that to the left in men ( p = 0.030), but no difference was found in women ( p = 0.297). Isometric strength in all directions in men was 1.2–1.7 times that in women (all p < 0.028). Correlations between physical measurements (height and weight) and strength values were all insignificant in both genders. Conclusion: Men have approximately 20–70% greater isometric neck muscle strength than women. Both men and women can maintain high levels of cervical muscle strength in six different directions up to their seventh decade. There is no significant correlation between physical measurements and isometric neck muscle strength.