Correlation of postural balance and knee muscle strength in the sit-to-stand test among women with and without postmenopausal osteoporosis

The task of standing up from a chair forms a part of daily life for all independent individuals. However, this task becomes more difficult with advancing age. Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.

INTRODUCTION

This study aims to evaluate postural balance during the transition from sitting to standing and its relationship with knee extensor and flexor strength among women with and without postmenopausal osteoporosis.

METHODS

Assessments were made on 126 women (aged 55-65 years), divided into osteoporosis and control groups according to lumbar bone density. Their balance during the task of standing up from a chair was evaluated using the Balance Master® device. Knee muscle strength was evaluated using an isokinetic dynamometer (Biodex®), in concentric/concentric mode, at a velocity of 60°/s. Spearman's correlation between the variables of muscle strength and postural balance was evaluated. Subsequently, to evaluate the association of each balance variable with the group and with muscle strength, multiple linear regression models were fitted. The significance level was set at 0.05.

RESULTS

There was a difference in knee muscle strength between the groups (P < 0.05). However, independent of the muscle strength values, there were no differences in relation to weight transfer times (P = 0.556) or center of gravity sway velocity (P = 0.952). Transfer time diminished with increasing extensor strength (P = 0.025). The center of gravity sway velocity tended to increase with increasing extensor strength (P = 0.013) and was the same in the two groups (P = 0.264).

CONCLUSION

Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.

Meniscectomy alters the dynamic deformational behavior and cumulative strain of tibial articular cartilage in knee joints subjected to cyclic loads

OBJECTIVE

Meniscectomy-induced osteoarthritis may be mechanically based. We asked how meniscectomy alters time-dependent deformation of physiologically loaded articular cartilage. We hypothesized that meniscectomy alters nominal strain in tibial articular cartilage, and that meniscectomy affects cartilage thickness recovery following cessation of loading.

METHODS

A cyclic load simulating normal gait was applied to four sheep knees. A custom device was used to obtain MR images of cartilage at 4.7T during cyclic loading. Articular cartilage thickness and nominal strain were measured every 2.5 min during 1h of cyclic loading, and during 2.5h after cessation of loading.

RESULTS

Following meniscectomy the loaded joints rapidly developed high strain centrally and minimal strain peripherally. Maximum nominal strains after 1h of loading were about 55% in the intact knees and 72% in the meniscectomized knees. Nominal strains in the peripheral tibial cartilage were significantly reduced in the meniscectomized knees. Strain recovery was markedly prolonged in the meniscectomized knees.

CONCLUSIONS

With meniscectomy, tibial articular cartilage in the central load bearing region remains chronically deformed and dehydrated, even after cessation of loading. Post-meniscectomy osteoarthritis may be initiated in this region by direct damage to the cartilage matrix, or by altering the hydration of the tissue. In peripheral regions, reduced loading and strain may facilitate subchondral vascular invasion, and endochondral ossification. This is consistent with the central fibrillation and peripheral osteophyte formation seen in post-meniscectomy osteoarthritis.

Articular cartilage MR imaging and thickness mapping of a loaded knee joint before and after meniscectomy

OBJECTIVE

We describe a technique to axially compress a sheep knee joint in an MRI scanner and measure articular cartilage deformation. As an initial application, tibial articular cartilage deformation patterns after 2 h of static loading before and after medial meniscectomy are compared.

METHODS

Precision was established for repeated scans and repeated segmentations. Accuracy was established by comparing to micro-CT measurements. Four sheep knees were then imaged unloaded, and while statically loaded for 2 h at 1.5 times body weight before and after medial meniscectomy. Images were obtained using a 3D gradient echo sequence in a 4.7 T MRI. Corresponding 3D cartilage thickness models were created. Nominal strain patterns for the intact and meniscectomized conditions were compared.

RESULTS

Coefficients of variation were all 2% or less. Root mean squared errors of MR cartilage thickness measurements averaged less than 0.09 mm. Meniscectomy resulted in a 60% decrease in the contact area (P=0.001) and a 13% increase in maximum cartilage deformation (P=0.01). Following meniscectomy, there were greater areas of articular cartilage experiencing abnormally high and low nominal strains. Areas of moderate nominal strain were reduced.

CONCLUSIONS

Medial meniscectomy resulted in increased medial tibial cartilage nominal strains centrally and decreased strains peripherally. Areas of abnormally high nominal strain following meniscectomy correlated with areas that are known to develop fibrillation and softening 16 weeks after medial meniscectomy. Areas of abnormally low nominal strain correlated with areas of osteophyte formation. Studies of articular cartilage deformation may prove useful in elucidating the mechanical etiology of osteoarthritis.

Effects of changes in cadence, prosthetic componentry, and time on interface pressures and shear stresses of three trans-tibial amputees

OBJECTIVE

To evaluate the effects of changes in cadence, prosthetic componentry, and time on interface pressures and resultant shear stresses in trans-tibial amputee case studies.

DESIGN

Interface stresses were monitored using custom-designed instrumentation at 13 sites on three subjects with unilateral trans-tibial amputation walking with patellar-tendon-bearing prosthetic limbs.

BACKGROUND

Previous studies suggested that week-to-week residual limb changes altered interface stresses more than did alterations in prosthetic alignment. No studies investigating effects of changes in cadence or componentry on interface stress distributions nor comparing their influence with week-to-week changes have been conducted previously.

METHODS

Five different prosthetic componentry configurations were tested at each of three cadences in four sessions. Data were analysed for the magnitudes and timings of peak pressures and resultant shear stresses as well as corresponding resultant shear angles.

RESULTS

None of the three cadences or five componentry configurations consistently induced significantly (P<0.05) higher or lower interface stress magnitudes for all subjects. However, an Aluminium Pylon/SACH Foot combination compared with an AirStance (pneumatic shank)/Seattle LightFoot unit induced later peak interface stress timings as a percentage of stance phase. Higher and more frequent interface stress changes were seen between the weekly sessions than between different cadences or between different componentry configurations.

CONCLUSION

The amputees' capabilities to compensate for week-to-week residual limb changes were less than those for intra-session cadence or componentry alterations.

RELEVANCE

Results suggest that effective techniques to accommodate week-to-week residual limb fluctuations could have a greater impact on maintaining consistent interface stress distributions than do adjustments in cadence or componentry.

A T-cell-selective interleukin 2 mutein exhibits potent antitumor activity and is well tolerated in vivo

Human interleukin 2 (IL-2; Proleukin) is an approved therapeutic for advanced-stage metastatic cancer; however, its use is restricted because of severe systemic toxicity. Its function as a central mediator of T-cell activation may contribute to its efficacy for cancer therapy. However, activation of natural killer (NK) cells by therapeutically administered IL-2 may mediate toxicity. Here we have used targeted mutagenesis of human IL-2 to generate a mutein with approximately 3,000-fold in vitro selectivity for T cells over NK cells relative to wild-type IL-2. We compared the variant, termed BAY 50-4798, with human IL-2 (Proleukin) in a therapeutic dosing regimen in chimpanzees, and found that although the T-cell mobilization and activation properties of BAY 50-4798 were comparable to human IL-2, BAY 50-4798 was better tolerated in the chimpanzee. BAY 50-4798 was also shown to inhibit metastasis in a mouse tumor model. These results indicate that BAY 50-4798 may exhibit a greater therapeutic index than IL-2 in humans in the treatment of cancer and AIDS.

Changes in interface pressure and stump shape over time: preliminary results from a trans-tibial amputee subject

Interface stresses and stump shape were measured during sessions over a two-month interval on a trans-tibial amputee subject. Results from thirteen transducer sites monitored during four sessions showed greater interface pressure changes over time at anterior sites than at lateral or posterior locations. There was a trend of decreased pressure with stump swelling and increased pressure for stump atrophy. During one session in which stump shape was monitored over a 23.1 min interval after ambulation, stump swelling was localised. Swelling tended to increase in the regions of initial enlargement, as opposed to redistributing through different areas over time. Regions of swelling were anterior lateral and posterior proximal, areas of thick underlying soft tissue. Identification of localised areas of swelling and atrophy and understanding of their effects on interface pressures could be used to improve individual socket design.

Energy, substrate and protein metabolism in morbid obesity before, during and after massive weight loss

OBJECTIVE

To investigate the effect of surgically induced weight loss on energy, substrate and protein metabolism of morbidly obese patients.

DESIGN

A prospective, clinical intervention study of morbidly obese patients before and after surgical treatment.

SUBJECTS

Eight morbidly obese patients (BMI 47.88+/-7.03).

METHODS

Total energy expenditure (TEE; doubly labeled water method), sleeping metabolic rate (SMR; respiration chamber), body composition (deuterium oxide component of doubly labeled water), substrate metabolism (48 h dietary records, 48 h urine collection and gaseous exchange in the respiration chamber) and whole body protein turnover (primed-continuous infusion of L-[1-13C]-leucine) were measured before, 3 and 12 months after vertical banded gastroplasty (VBG).

RESULTS

The TEE decreased as a result of a decreased SMR (64%) and non-SMR (36%; P=0.001). SMR as a function of fat-free mass (FFM) decreased after weight loss (P<0.05). The physical activity index (PAI), defined as TEE/SMR, was low and was not influenced by weight loss. Protein and carbohydrate oxidation decreased significantly after VBG (P<0.05), although 3 months after VBG protein oxidation did not decrease enough to prevent loss of FFM. The energy used for protein turnover was approximately 24% of SMR and did not change after weight loss.

CONCLUSIONS

Compensatory processes that oppose weight loss of morbidly obese patients exist, as demonstrated by the disproportional reduction of SMR, and a low PAI. Protein turnover is not a major contributor to the disproportional reduction of SMR.

The structure of the two amino-terminal domains of human intercellular adhesion molecule-1 suggests how it functions as a rhinovirus receptor

The normal function of human intercellular adhesion molecule-1 (ICAM-1) is to provide adhesion between endothelial cells and leukocytes after injury or stress. ICAM-1 binds to leukocyte function-associated antigen (LFA-1) or macrophage-1 antigen (Mac-1). However, ICAM-1 is also utilized as a receptor by the major group of human rhinoviruses and is a catalyst for the subsequent viral uncoating during cell entry. The three-dimensional atomic structure of the two amino-terminal domains (D1 and D2) of ICAM-1 has been determined to 2.2 A resolution and fitted into a cryo-electron microscopy reconstruction of a rhinovirus-ICAM-1 complex. Rhinovirus attachment is confined to the BC, CD, DE and FG loops of the amino-terminal immunoglobulin-like domain (D1) at the end distal to the cellular membrane. The loops are considerably different in structure to those of human ICAM-2 or murine ICAM-1 which do not bind rhinoviruses. There are extensive charge interactions between ICAM-1 and human rhinoviruses, which are mostly conserved in both major and minor receptor groups of rhinoviruses. The interaction of ICAMs with LFA-1 is known to be mediated by a divalent cation bound to the I-(insertion) domain on the alpha chain of LFA-1 and the carboxy group of a conserved glutamic acid residue on ICAMs. Domain D1 has been docked with the known structure of the I-domain. The resultant model is consistent with mutational data and provides a structural framework for the adhesion between these molecules.

Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament

The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average internal between occurrence of the injury and assessment was 10.2 months (range 2-48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60 degrees/sec and 240 degrees/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60 degrees/sec was greater than that at 240 degrees/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60 degrees/sec or at 240 degrees/sec. The average value for the flexor-extensor relationship at 60 degrees/sec on the injured was 60% ((6), compared to 57% ((10) on the contra-lateral side. At 240 degrees/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60 degrees/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the extensor muscle group, and this tendency was more pronounced on the side of the injury.

An immune cell-selective interleukin 4 agonist

Interleukin 4 (IL-4) is a pleiotropic cytokine. Of the cell types responsive to IL-4, T cells express one IL-4 receptor (IL-4R) type, IL-4Ralpha/IL-2Rgamma (class I IL-4R), whereas endothelial cells express another type, IL-4Ralpha/IL-13Ralpha (class II IL-4R). It was hypothesized that IL-4 variants could be generated that would be selective for cell types expressing the different IL-4Rs. A series of IL-4 muteins were generated that were substituted in the region of IL-4 implicated in interactions with IL-2Rgamma. These muteins were evaluated in T cell and endothelial cell assays. One of these muteins, containing the mutation Arg-121 to Glu (IL-4/R121E), exhibited complete biological selectivity for T cells, B cells, and monocytes, but showed no activity on endothelial cells. Receptor binding studies indicated that IL-4/R121E retained physical interaction with IL-2Rgamma but not IL-13Ralpha; consistent with this observation, IL-4/R121E was an antagonist of IL-4-induced activity on endothelial cells. IL-4/R121E exhibits a spectrum of activities in vitro that suggest utility in the treatment of certain autoimmune diseases.

Material properties of commonly-used interface materials and their static coefficients of friction with skin and socks

Compressive stiffness (CS) of different supporting materials used in prosthetics and orthotics and their static coefficients of friction (COF) with skin and socks were characterized. Materials tested included Spenco, Poron, nylon-reinforced silicone, Soft Pelite, Medium Pelite, Firm Plastazote, Regular Plastazote, and Nickelplast. A displacement-controlled testing device was constructed to assess the CS of 11.1 mm diameter material specimens under cyclic loading (1 Hz) to 220 kPa over 10- and 60-min periods. Results demonstrated local CS ranging from 687 kPa (Poron) to 3,990 kPa (Soft Pelite). To fit the cyclic stress-strain (S-S) data within an error of 4.0 percent full-scale output, the minimum order of fit required for Spenco, Poron, and nylon-reinforced silicone was a third-order polynomial; for Soft Pelite, Medium Pelite, Firm Plastazote, and Regular Plastazote, a second-order polynomial; and for Nickelplast, a linear fit. For all materials, the nonrecovered strains were related to loading time using an exponential fit. A biaxial force-controlled load applicator device was used to assess COF at skin-material, sock-material, and skin-sock interfaces for shear forces of 1 to 4 N applied to a 10.2 x 7.8 mm loading pad. COFs ranged from 0.48 (+/- 0.05) to 0.89 (+/- 0.09). COFs at skin-material interfaces were significantly (p < 0.05) higher than those at skin-sock interfaces. There was a trend of a higher COF at sock-material interfaces than at skin-sock interfaces. These data are of potential utility in finite element modeling sensitivity analysis of residual limb-prosthetic socket systems or body-orthosis systems to characterize effects of material features on interface pressure and shear stress distributions.

The structure of the two amino-terminal domains of human ICAM-1 suggests how it functions as a rhinovirus receptor and as an LFA-1 integrin ligand

The normal function of human intercellular adhesion molecule-1 (ICAM-1) is to provide adhesion between endothelial cells and leukocytes after injury or stress. ICAM-1 binds to leukocyte function-associated antigen (LFA-1) or macrophage-1 antigen (Mac-1). However, ICAM-1 is also used as a receptor by the major group of human rhinoviruses and is a catalyst for the subsequent viral uncoating during cell entry. The three-dimensional atomic structure of the two amino-terminal domains (D1 and D2) of ICAM-1 has been determined to 2.2-A resolution and fitted into a cryoelectron microscopy reconstruction of a rhinovirus-ICAM-1 complex. Rhinovirus attachment is confined to the BC, CD, DE, and FG loops of the amino-terminal Ig-like domain (D1) at the end distal to the cellular membrane. The loops are considerably different in structure to those of human ICAM-2 or murine ICAM-1, which do not bind rhinoviruses. There are extensive charge interactions between ICAM-1 and human rhinoviruses, which are mostly conserved in both major and minor receptor groups of rhinoviruses. The interaction of ICAMs with LFA-1 is known to be mediated by a divalent cation bound to the insertion (I)-domain on the alpha chain of LFA-1 and the carboxyl group of a conserved glutamic acid residue on ICAMs. Domain D1 has been docked with the known structure of the I-domain. The resultant model is consistent with mutational data and provides a structural framework for the adhesion between these molecules.

[Interpretation of the quantitative data of the computerized baropodometry in normal subjects]

The present work intended to test the validity of the quantitative datas provided by computerized baropodometry based in three comparisons: between static vertical force on the three regions of the foot and weight, between vertical force on the three regions of the foot during gait and weight, and between peak plantar pressure on the three regions of the foot and weight. It was used body weight because the calibration of the equipment is done in relation to the body weight of the patient. It was selected ten volunteers without foot pain complaints, age between 27-54 years old, 6 women and 4 men. The equipment used was the FSCAN version 1.821 (Teckscan, Boston MA), with new insoles. At the static assessment, the correlation between vertical force and weight was statistically significant only to the midfoot. At the assessment during gait the correlation between vertical force and weight was statistically significant for all regions of the foot and the correlation between peak plantar pressure and weight was statistically significant only to the midfoot. The clinical interpretation of the quantitative data provided by this exam must be done with caution due to uncount variables that are involved.

Surface expression of intercellular adhesion molecule 1 on epithelial cells in the human adenoid

Human rhinoviruses enter the host by way of the nose and conjunctiva. Intercellular adhesion molecule 1 (ICAM-1) is the cellular receptor for the majority of rhinoviruses. ICAM-1 expression on the luminal surface of epithelial cells in the upper airway may be an important determinant of virus localization in the airway. Eighteen adenoids and 5 nasopharyngeal biopsies were evaluated by immunohistochemistry for surface expression of ICAM-1. Heavy immunoreactivity of ICAM-1 was found on the surface of a small number of single nonciliated cells in the lymphoepithelium. Squamous epithelial cells showed minimal to no staining, and ciliated epithelium had positive ICAM-1 staining of the basal cells but not on the ciliated border. The localization of ICAM-1 expression to specific, limited areas of the surface epithelium of the nasopharynx may have important implications in the pathogenesis of rhinovirus infections, especially initiation of the host response to rhinovirus.

Identification and cloning of human placental bikunin, a novel serine protease inhibitor containing two Kunitz domains

Interrogation of the public expressed sequence tag (EST) data base with the sequence of preproaprotinin identified ESTs encoding two potential new members of the Kunitz family of serine protease inhibitors. Through reiterative interrogation, an EST contig was obtained, the consensus sequence from which encoded both of the novel Kunitz domains in a single open reading frame. This consensus sequence was used to direct the isolation of a full-length cDNA clone from a placental library. The resulting cDNA sequence predicted a 252-residue protein containing a putative NH2-terminal signal peptide followed sequentially by each of the two Kunitz domains within a 170-residue ectodomain, a putative transmembrane domain, and a 31-residue hydrophilic COOH terminus. The gene for this putative novel protein was mapped by use of a radiation hybrid panel to chromosome 19q13, and Northern analysis showed that the corresponding mRNA was expressed at high levels in human placenta and pancreas and at lower levels in brain, lung, and kidney. An endogenous soluble form of this protein, which was designated as placental bikunin, was highly purified from human placenta by sequential kallikrein-Sepharose affinity, gel filtration, and C18 reverse-phase chromatography. The natural protein exhibited the same NH2 terminus as predicted from the cloned cDNA and inhibited trypsin, plasma kallikrein, and plasmin with IC50 values in the nanomolar range.

[Evaluation of isokinetic trunk flexion and extension in normal sportsman and sedentary people]

It was studied two groups: Group 1: 13 male voluntaries, competition sportsman, mean age: 25 +/- 2.1 years (18-30): Group 2: 17 male voluntaries, sedentary, mean age: 31.2 years (23-46). All the voluntaries was evaluated by the CYBEX 6000, TEF (trunk flexion extension) module. The parameters analyzed were: peak torque, total work and average power (absolute values and corrected by the body weight) and the flexion/extension relation. All the tests were performed at the speed of 60 and 120 degrees per second. The peak torque absolute values at 60 and 120 degrees were higher in Group 1 than Group 2 (p < 0.05), in flexion and extension movement. At the corrected date by the body weight, this relation remained the same, at 60 degrees, for flexion and extension and for extension at 120 degrees (p < 0.05), but the flexion at 120 degrees is not different in both groups. The peak torque angle is the same for extensor tests at both speed, but is different for the flexor test, at 60 degrees. The total work performed was better in the Group 1 at 60 degrees during the flexion (p < 0.05) and during the extension in both tested speed. At the corrected values the work is the same at flexion and at extension is higher only at 120 degrees (p < 0.05). At the average power of flexion movement there is a difference at the absolute values, that was not seen at the body weight corrected date. The difference between average power of the extension, in both speeds was significant at 60 and 120 degrees. The relation between flexor and extensor: Group 1: peak torque 80% at 60 degrees, total work and average power is nearly 100%; Group 2: peak torque, total work and average power is closed to 100%, at 60 degrees. The flexor muscles values are light higher than the extensor muscles, that means the abdominal muscles are stronger than the spine erector muscles. At 120 degrees this tendency is more clear and the relation is 120-125% and at the sedentary group this relation is higher: 150-165%.

Prevention of rhinovirus infection in chimpanzees by soluble intercellular adhesion molecule-1

Intercellular adhesion molecule-1 (ICAM-1) is the cell surface receptor for the major class of human rhinoviruses, and tICAM453, a truncated, soluble form of ICAM-1, has been shown previously to be a potent in vitro inhibitor of rhinovirus. In this report, we have investigated the in vivo efficacy of tICAM453 for the prophylaxis of rhinovirus serotype 16 infection in the chimpanzee. Because chimpanzees do not show clinical symptoms of infection after rhinovirus challenge, infection was followed by measuring antirhinovirus serum antibody responses and detection of virus shedding. By both of these measures, intranasal application of tICAM453 was efficacious in preventing rhinovirus infection in chimpanzees subsequently challenged with infectious doses of virus. These results suggest that the use of soluble rhinovirus receptor to inhibit virus binding to host cells should be feasible in humans.

Spectrum of activity of soluble intercellular adhesion molecule-1 against rhinovirus reference strains and field isolates

The antiviral potency of soluble intercellular adhesion molecule-1 (ICAM-1; the major receptor for human rhinoviruses) was determined for a subset of American Type Culture Collection reference serotypes and field isolates of rhinovirus. The results indicate that soluble ICAM-1 exhibits a broad spectrum of activity against rhinoviruses and that field isolates have a sensitivity indistinguishable from that of laboratory strains.

[Physiopathology and clinical evaluation of spasticity]

The spasticity is a motor alteration of the muscle tonus caused by the spinal reflex hyperactivity, related to the increasing of the muscle reaction to the stretching. It is very frequent in the upper motor neuron lesional.

Crystallographic and cryo EM analysis of virion-receptor interactions

Cryoelectron microscopy has been used to determine the first structure of a virus when complexed with its glycoprotein cellular receptor. Human rhinovirus 16 (HRV16) complexed with the two amino-terminal, immunoglobulin-like domains of the intercellular adhesion molecule-1 (ICAM-1) shows that ICAM-1 binds into the 12 A deep "canyon" on the surface of the virus. This is consistent with the prediction that the viral receptor attachment site lies in a cavity inaccessible to the host's antibodies. The atomic structures of HRV14 and CD4, homologous to HRV16 and ICAM-1, showed excellent correspondence with observed density, thus establishing the virus-receptor interactions.

Podometry: a critical evaluation of its use in Hansen's disease

The aim of this paper is to evaluate the effectiveness of podometry to measure the pressure developed over the feet and the value of these findings to help in the prevention of the plantar neuropathic ulcer in patients bearing Hansen's disease. We evaluated 13 patients with impaired plantar pain and touch sensations and 17 normal patients. All the patients were submitted to static evaluation using the podometer. The system employed was the "Midcapteur" commercial podometer composed of a platform for acquisition of analogic data capable of registering the segmental pressures applied to the feet. These data are read by a 386 IBM/PC compatible computer that registers the graphic patterns obtained from the pressures developed and also calculates the modes of pressure distribution in the four quadrants of the foot. These data obtained by means of static podometry were compared to the clinical evaluation of pain and touch sensation of the feet in hansenian patients. The results demonstrate that podometery is an efficient method for evaluating the pressure in impaired feet in Hansen's disease and is a progression of neuropathic ulcer; it is sensitive in the identification of the spots of increased pressure in anesthetic and anomalous areas, asymmetries and in correlating the presence of ulcers with increased pressure.

Functional electrical stimulation (FES): muscle histochemical analysis

Functional electrical stimulation (FES) has been used in Brazil since 1989 to obtain functional improvement in paraplegic patients' orthostasis and locomotion. The aim of this paper is to evaluate the histochemical changes observed in the quadriceps femoris muscle following the use of FES. We studied four patients with traumatic spinal cord lesions at T4-10 level, Frankel A, all within 12-24 months postlesion. They were all submitted to FES using the following criteria: square-wave, 20-30 Hz frequency, pulses of 0.003 seconds, time of stimulation 5 seconds, resting interval 10 seconds. The stimulation was applied during 90 consecutive days, 30 minutes each time, twice daily. The interval between the stimulations was 6 hours. Quadriceps muscle biopsies were performed before and after the use of FES. We used ATPase technique for the histochemical analysis, where three different dying patterns can be observed for the three types of muscular fibres (I, IIa and IIb). The two samples from each patient were analysed measuring the fibres' diameters and their index of atrophy, and counting the total number of each type of fibre in each sample. The mean total number of fibres in each sample was 256 +/- 12.3. The results showed that the sizes of the three types of fibres were not modified with the use of FES; the number of type IIa fibres increased in a significant fashion, after using of FES.

Cell contact between T cells and synovial fibroblasts causes induction of adhesion molecules and cytokines

Human activated T cells adhere to synovial fibroblast-like cells in vitro. The present study was conducted to investigate the consequences of T cell-synovial fibroblast interactions with regard to induction of adhesion molecules and proinflammatory cytokines. A sensitive Western blot technique, polymerase chain reaction (PCR) amplification, and fluorescence-activated cell sorter (FACS) analysis were used to analyze the induction of VCAM-1 and ICAM-1 expression in T cell-synovial fibroblast cocultures. VCAM-1 and ICAM-1 expression could be induced in synovial fibroblast-like cells by 2 h. PCR amplification showed that both forms of VCAM-1 mRNA are found after the interaction of synovial fibroblasts with T cells. Up-regulation of VCAM-1 and ICAM-1 was confined to synovial fibroblasts; T cells did not express VCAM-1 or increased ICAM-1. In contrast to the T cell-synoviocyte interaction, the interaction between T cells and dermal fibroblasts resulted in the up-regulation of ICAM-1 but not VCAM-1, suggesting tissue-specific regulation of VCAM-1. The T cell-synovial fibroblast interaction also resulted in increased levels of tumor necrosis factor (TNF), interferon-gamma, and interleukin-6 in coculture supernatant. Of the neutralizing antibodies used against these cytokines, only anti-TNF could significantly inhibit VCAM-1 and ICAM-1 expression. When T cells were separated from synoviocytes by a chamber that allowed medium exchange but no cell contact, VCAM-1 and ICAM-1 failed to be up-regulated and cytokine accumulation in cocultures was drastically reduced. Our results demonstrate mutual cell activation of T cells and synoviocytes upon cell contact as shown by the release of T cell- and synoviocyte-specific cytokines and suggest a cell contact-mediated and T cell-initiated mechanism for the chronic accumulation and retention of mononuclear cells via VCAM-1/ICAM-1 by synovial fibroblasts in the rheumatoid synovium.

Structure of a human rhinovirus complexed with its receptor molecule

Cryoelectron microscopy has been used to determine the structure of a virus when complexed with its glycoprotein cellular receptor. Human rhinovirus 16 complexed with the two amino-terminal, immunoglobulin-like domains of the intercellular adhesion molecule 1 shows that the intercellular adhesion molecule 1 binds into the 12-A deep "canyon" on the viral surface. This result confirms the prediction that the viral-receptor attachment site lies in a cavity inaccessible to the host's antibodies. The atomic structures of human rhinovirus 14 and CD4, homologous to human rhinovirus 16 and intercellular adhesion molecule 1, showed excellent correspondence with observed density, thus establishing the virus-receptor interactions.

Formation of rhinovirus-soluble ICAM-1 complexes and conformational changes in the virion

Viral receptors serve both to target viruses to specific cell types and to actively promote the entry of bound virus into cells. Human rhinoviruses (HRVs) can form complexes in vitro with a truncated soluble form of the HRV cell surface receptor, ICAM-1. These complexes appear to be stoichiometric, with approximately 60 ICAM molecules bound per virion or 1 ICAM-1 molecule per icosahedral face of the capsid. The complex can have two fates, either dissociating to yield free virus and free ICAM-1 or uncoating to break down to an 80S empty capsid which has released VP4, viral RNA, and ICAM-1. This uncoating in vitro mimics the uncoating of virus during infection of cells. The stability of the virus-receptor complex is dependent on temperature and the rhinovirus serotype. HRV serotype 14 (HRV14)-ICAM-1 complexes rapidly uncoat, HRV16 forms a stable virus-ICAM complex which does not uncoat detectably at 34 degrees C, and HRV3 has an intermediate phenotype. Rhinovirus can also uncoat after exposure to mildly acidic pH. The sensitivities of individual rhinovirus serotypes to ICAM-1-mediated virus uncoating do not correlate with uncoating promoted by incubation at low pH, suggesting that these two means of virus destabilization occur by different mechanisms. Soluble ICAM-1 and low pH do not act synergistically to promote uncoating. The rate of uncoating does appear to be inversely related to virus affinity for its receptor.

Evaluation of the physical fitness by the Bruno Balke protocol in sedentary and wheelchair trained paraplegic patients

The Bruno Balke test is one of the methods available to measure the oxygen intake in wheelchair users. The equation of the test is:intake O2 = 33+ (speed average-133) x 0.17 ml/kg x min. (-1). The average speed represents the acceleration and may be used to measure the level of physical fitness. In order to verify the efficiency of this kind of evaluation, we selected ten male, sedentary paraplegic patients, level D5-D12 in an ordinary rehabilitation program and ten paraplegic athletes. All of them were submitted to the Bruno Balke test. The results demonstrated that the average speed, the covered distance and the oxygen intake were significantly greater in athletes than in sedentary individuals.

Preliminary X-ray crystallographic analysis of intercellular adhesion molecule-1

Crystals of the two amino-terminal domains of intercellular adhesion molecule-1, the receptor for the major group of human rhinovirus serotypes, diffract to 3.0 A resolution. The crystals are trigonal in space group P3(1)21 or P3(2)21 with cell dimensions of a = b = 55.7 A, c = 166.3 A, with probably six molecules per unit cell.

[Physiatric treatment of pain in osteoarthrosis]

The osteoarthrosis is a disease of high incidence in the population affecting chiefly middle-aged women. The chronic pain is the main cause of incapacity and may be responsible for the secondary articular alterations in theses patients. This paper reviews the physiopathology and the treatment of the pain in osteoarthrosis.

[Functional electrical stimulation in the reciprocal locomotion of paraplegic patients]

The functional electrical stimulations is employed for standing-up posture and reciprocal locomotion in paraplegic patients. Five male paraplegic patients, level D5-D12 mean age 32.4 years, were treated with functional electrical stimulation, during two months. The quadriceps and fibular nerves were stimulated for 30 minutes, twice a day. After the training period, two patients were able to remain in the stand-up position and walk in parallel bars; one of them was able to use a walker. In other patients the technique was without effect for standing and walking. This method is not the solution for locomotion of paraplegics and more research is needed for the improvement of the results of functional electrical stimulation.

Expression of vascular cell adhesion molecule-1 in fibroblastlike synoviocytes after stimulation with tumor necrosis factor

Rapid expression of mRNA encoding vascular cell adhesion molecule-1 (VCAM-1) was induced by tumor necrosis factor (TNF) in fibroblast-like cells obtained from synovial tissue. Both alternatively spliced forms of VCAM-1 mRNA were detected by polymerase chain reaction in TNF-stimulated fibroblast-like synoviocytes. Western blotting analysis showed that two distinct proteins, reactive with an anti-VCAM-1 anti-sera, were expressed by 2 hours of TNF stimulation in both synoviocytes and human umbilical cord vein endothelial cells (HUVEC). The majority of HUVEC and synoviocytes displayed VCAM-1 surface expression after several hours of TNF stimulation. In contrast, dermal fibroblasts upregulated intercellular adhesion molecule-1 (ICAM-1) but not VCAM-1 expression in response to TNF. These results indicate that VCAM-1 and ICAM-1 expression can be differentially regulated and suggest tissue specific regulation of VCAM-1 expression. Furthermore, these findings may provide an explanation for the chronic retention and activation of long-lived lymphocytes and monocytes, which express VLA-4 (the receptor for VCAM-1), in the synovium in rheumatoid arthritis.

Clinical fundaments for rehabilitation treatment in spinal cord injury

Spinal cord injury leads to a severe disabling syndrome, which most often affects the young. The major etiologic factor in spinal cord injuries is trauma. Patients' rehabilitation is started in the acute phase, soon after the trauma occurs, mainly through preventive care against the formation of pressure sores, deformities of the palsy segments, proper vesical and bowel emptying and care with vasomotor alterations. The rehabilitation process continues at a specialized rehabilitation center, searching the best functional performance of each patient, according to the type and level of the spinal cord injury. This work shows fundaments for the rehabilitation treatment.

Atlanto-axial dislocation in children

The authors present 14 cases of C1 C2 dislocations in children (8 boys and 6 girls; mean age, 6.9 years) seen at the Orthopedics and Traumatology Institute of the University Hospital, Faculty of Medicine, University of São Paulo from 1978 to 1990. In view of the disappointing results obtained by conservative treatment in 6 of the 14 patients, the authors recommend early atlanto-axial arthrodesis in cases of C1 C2 dislocation in children.

Mechanisms of receptor-mediated rhinovirus neutralization defined by two soluble forms of ICAM-1

The majority of human rhinoviruses use intercellular adhesion molecule 1 (ICAM-1) as a cell surface receptor. Two soluble forms of ICAM-1, one corresponding to the entire extracellular portion [tICAM(453)] and one corresponding to the two N-terminal immunoglobulin-like domains [tICAM(185)], have been produced, and their effects on virus-receptor binding, virus infectivity, and virus integrity have been examined. Results from competitive binding experiments indicate that the virus binding site is largely contained within the two N-terminal domains of ICAM-1. Virus infectivity studies indicate that tICAM(185) prevents infection by direct competition for receptor binding sites on virus, while tICAM(453) prevents infection at concentrations 10-fold lower than that needed to inhibit binding and apparently acts at the entry or uncoating steps. Neutralization by both forms of soluble ICAM-1 requires continual presence of ICAM-1 during the infection and is largely reversible. Both forms of soluble ICAM-1 can alter rhinovirus to yield subviral noninfectious particles lacking the viral subunit VP4 and the RNA genome, thus mimicking virus uncoating in vivo, although this irreversible modification of rhinovirus is not the major mechanism of virus neutralization.

[Traumatic disk hernia of the cervical spine]

The authors present 26 cases of traumatic disc herniation in the cervical spine submitted to anterior discectomy. All of the patient presented neurologic deficit, being 18 classified as Frankel A, three as Frankel B, 2 Frankel C and 3 Frankel D. There were observed three deaths in the immediate post-operative period due to respiratory insufficiency in patients classified as Frankel A. The other 23 cases have a follow-up of 14 months (6-84 months), presenting improvement of the neurologic deficit in six patients classified as Frankel B, C and D and only one as Frankel A. The authors emphasize the importance of the image methods in the diagnosis of this lesion.

[Femoral fracture in patients with spinal cord injury]

Femoral fractures during the physical therapy in two patients with spinal cord injury and consequent osteoporosis in the paralyzed limbs are reported. The fractures were caused by a minor trauma and the spasticity was considered to be an additional factor in the accident. During the physical therapy the patients were seated with hip abduction and flexion of the knee. It is important that the patients participate in a program of physiotherapy. This, however, should be performed under strict control.

Identification of monoclonal antibody epitopes and critical residues for rhinovirus binding in domain 1 of intercellular adhesion molecule 1

Intercellular adhesion molecule 1 (ICAM-1) is the cellular receptor for the major group of human rhinoviruses (HRVs) and the adhesion ligand of lymphocyte function-associated antigen 1. Analysis of a series of chimeric exchanges between human and murine ICAM-1 shows that two distinct epitopes recognized by monoclonal antibodies that block rhinovirus attachment and cell adhesion map to the N-terminal first domain of ICAM-1. Furthermore the specificity for HRV binding is entirely contained within the first 88 amino acids. Mutagenesis of the four sites of N-linked glycosylation within the second domain shows that carbohydrate is not involved in virus recognition. Homologue replacement mutagenesis localizes the epitopes for virus-blocking antibodies to two regions of domain 1 predicted to form beta strand D and the loop between the F and G strands of an immunoglobulin-fold structure. Analysis of virus binding to the mutants predicts a large surface of contact between HRV and ICAM-1 domain 1 but shows that the regions most important for virus binding are coincident with the monoclonal antibody epitopes.

[Functional rehabilitation of degenerative tendinous injuries of the shoulder]

We studied 60 shoulders in a group of 58 patients, with injuries of shoulder tendons. Thirty-one patients presented impingement syndrome, eighteen patients calcareous tendinitis, five patients rotator cuff rupture, three patients bicipital tendinitis and three patients multiple lesions. All of them were submitted to physical therapy: ultra-sound and kinesio-therapy. Good results were obtained in 55% of the patients. Bad results were recorded in women, young people and in patients with calcareous tendinitis.

[Epidemiological study of patients with spinal cord injuries and neurologic deficit, admitted to the Institute of Orthopedics and Traumatology at the Hospital das Clinicas of the School of Medicine of the University of São Paulo]

The authors present an epidemiologic study concerning the spinal cord injuries treated at the Department of Orthopaedics and Traumatology of the School of Medicine of the University of São Paulo from 1982 to 1987. Out of 428 patients 94.3% were male, their age being mainly between 21 and 30 years. The segment more frequently affected was the cervical spine. The more frequent causes were the gunshot wounds and the traffic accidents. The incidence of death was 21%, caused mostly by respiratory failure.

The major human rhinovirus receptor is ICAM-1

The major human rhinovirus receptor has been identified with monoclonal antibodies that inhibit rhinovirus infection. These monoclonal antibodies recognize a 95 kd cell surface glycoprotein on human cells and on mouse transfectants expressing a rhinovirus binding phenotype. Purified 95 kd protein binds to rhinovirus in vitro. Protein sequence from the 95 kd protein showed an identity with that of intercellular adhesion molecule-1 (ICAM-1); a cDNA clone obtained from mouse transfectants expressing the rhinovirus receptor had essentially the same sequence as ICAM-1. Thus, the major human rhinovirus receptor is ICAM-1. The gene for this receptor maps to human chromosome 19, which also contains the genes for a number of other picornavirus receptors.

Identification of a secondary sperm receptor in the mouse egg zona pellucida: role in maintenance of binding of acrosome-reacted sperm to eggs

During fertilization in mice, acrosome-intact sperm bind via plasma membrane overlying their head to a glycoprotein, called ZP3, present in the egg extracellular coat or zona pellucida. Bound sperm then undergo the acrosome reaction, which results in exposure of inner acrosomal membrane, penetrate through the zona pellucida, and fuse with egg plasma membrane. Thus, in the normal course of events, acrosome-reacted sperm must remain bound to eggs, despite loss of plasma membrane from the anterior region of the head and exposure of inner acrosomal membrane. Here, we examined maintenance of binding of sperm to the zona pellucida following the acrosome reaction. We found that polyclonal antisera and monoclonal antibodies directed against ZP2, another zona pellucida glycoprotein, did not affect initial binding of sperm to eggs, but inhibited maintenance of binding of sperm that had undergone the acrosome reaction on the zona pellucida. On the other hand, polyclonal antisera and monoclonal antibodies directed against ZP3 did not affect either initial binding of acrosome-intact sperm to eggs or maintenance of binding following the acrosome reaction. We also found that soybean trypsin inhibitor, a protein reported to prevent binding of mouse sperm to eggs, did not affect initial binding of sperm to eggs, but, like antibodies directed against ZP2, inhibited maintenance of binding of sperm that had undergone the acrosome reaction on the zona pellucida. These and other observations suggest that ZP2 serves as a secondary receptor for sperm during the fertilization process in mice and that maintenance of binding of acrosome-reacted sperm to eggs may involve a sperm, trypsin-like proteinase.

Nature of the mouse egg's receptor for sperm

The zona pellucida is an extracellular coat that surrounds all mammalian eggs. Sperm must penetrate the zona pellucida in order to reach and fuse with the plasma membrane of unfertilized eggs. Penetration is accomplished by a sequence of events involving both egg and sperm. First, sperm must bind to the outer margin of the zona pellucida. Such binding is mediated in a relatively species-specific manner by "sperm receptors" in the zona pellucida. Second, sperm must undergo the "acrosome reaction", a membrane fusion event, in order to traverse the zona pellucida. Here we review results from our own laboratory which demonstrate that, during the course of sperm-egg interaction in mice, zona pellucida glycoprotein ZP3 serves as both receptor for sperm and inducer of the acrosome reaction. Furthermore, we review evidence from our laboratory indicating that the sperm receptor activity of ZP3 is dependent only on its 0-linked carbohydrate components, whereas acrosome reaction-inducing activity is dependent on the polypeptide portion of ZP3 as well.

Immunocytochemical localization of 140 kD cell adhesion molecules in cultured chicken fibroblasts, and in chicken smooth muscle and intestinal epithelial tissues

A monoclonal antibody (JG22 MAb) that was previously raised to a chick embryo myogenic cell preparation had been shown to produce rounding and other morphological changes in myogenic cells in culture, and, in some cases, their detachment from the substratum. In other studies it was shown that the epitope recognized by JG22 was associated with a set of 140 kD cell surface glycoproteins. It is shown that this antigen occurs in a wide variety of cell types; in cultured fibroblasts, it is distributed equally between the dorsal and ventral cell surfaces shortly after plating, but appears to become concentrated on the ventral surface as cell spreading proceeds; by immunoelectron microscopic labeling experiments, it is absent from the focal adhesion contact sites formed by fibroblasts with their substrata and with one another, but is present in clusters at the edge of focal adhesions, and within the close contact sites and extracellular matrix contact sites; in smooth muscle cells, it is absent from the membrane-associated dense plaques, but is located in clusters at adjacent membrane sites; in intestinal epithelium, it is present in clusters at the basolateral membranes, but not at the microvilli or within junctional complexes of the brush border of the cell layers. These and other results are consistent with the suggestion that the antigen recognized by JG22 MAb is important cell adhesion molecules, and performs a characteristic function in a variety of cell-cell contacts and cell adhesions.

Mouse egg extracellular coat is a matrix of interconnected filaments possessing a structural repeat

As the result of a combined biochemical and electron microscopic investigation, hitherto unrecognized structural features of the mouse egg extracellular coat, or zona pellucida, have been revealed. Specimens were prepared for electron microscopy by spraying individually isolated zonae pellucidae onto a substrate and were observed by both rotary shadowing and negative staining techniques. Results of these experiments suggest that the three zona pellucida glycoproteins, ZP1 (200,000 Mr), ZP2 (120,000 Mr) and ZP3 (83,000 Mr), are organized into long filaments. Negatively stained zona pellucida filaments resemble "beads-on-a-string", with each bead (9.5 nm in diameter) located every 17 nm or so (center-to-center distance) along the axis of the filament. The filaments, in turn, appear to be interconnected by one of the three zona pellucida glycoproteins, ZP1, giving rise to a three-dimensional matrix. Proteolysis of ZP1 by chymotrypsin or reduction of intermolecular disulfides of ZP1 by dithiothreitol results in both solubilization of zonae pellucidae and disruption of interconnections between individual zona pellucida filaments. These observations suggest that the zona pellucida, which plays important roles both during and after fertilization of mammalian eggs, is a highly organized extracellular coat in which glycoproteins are assembled into filaments possessing a recognizable structural repeat.

Biosynthesis of the sperm receptor during oogenesis in the mouse

During their growth phase, mouse oocytes synthesize and secrete three different glycoproteins, called ZP1, 2 and 3, that constitute the extracellular coat, or zona pellucida, of the oocyte. One of these glycoproteins, ZP3, exhibits properties expected for a sperm receptor. We have now used rabbit antisera that recognize ZP3 to immunoprecipitate [35S]methionine-labeled, intracellular precursors of this glycoprotein from growing oocytes cultured in vitro in the presence or absence of tunicamycin, a drug that prevents addition of N-linked oligosaccharides to nascent polypeptide chains. Electrophoretic analyses of these immunoprecipitates, as well as of immunoprecipitates digested with endo-beta-N-acetylglucosaminidase H (Endo H), indicate that ZP3 is synthesized as a 44,000 mol. wt. polypeptide chain to which either three or four high-mannose-type oligosaccharides are added, resulting in 53,000 and 56,000 mol. wt. ZP3 precursors, respectively. The latter species are converted to mature ZP3 (mol. wt. approximately 80,000) by processing of the high-mannose-type oligosaccharides (Endo H-sensitive) to complex-type oligosaccharides (Endo H-insensitive) prior to ZP3 secretion. The evidence presented reveals that the extreme heterogeneity of mature ZP3, with respect to both mol. wt. and isoelectric point, is partly a consequence of the N-linked oligosaccharides and not the polypeptide chain itself.

Biosynthesis of the major zona pellucida glycoprotein secreted by oocytes during mammalian oogenesis

An antiserum directed specifically against ZP2, the major glycoprotein of the mouse egg's extracellular coat (zona pellucida), has been used to immunoprecipitate intracellular precursors of ZP2 that were synthesized by growing mouse oocytes cultured in vitro. Pulse-chase experiments revealed that the immediate precursor of mature, 120 kilodalton (kd) ZP2 is a 91 kd species that unlike mature ZP2, is sensitive to digestion by endo-beta-N-acetylglucosaminidase H (Endo H) and is converted by the endoglycosidase into an 81 kd species. An 81 kd species is only found intracellularly when growing oocytes are cultured in the presence of tunicamycin. These results suggest that ZP2 is synthesized as an 81 kd polypeptide chain that is first "core"-glycosylated at asparagine residues with high-mannose-type oligosaccharides, giving rise to a 91 kd intermediate (Endo-H-sensitive), and then processed to complex-type oligosaccharides prior to secretion as mature, 120 kd ZP2 (Endo H-insensitive). Furthermore, electrophoretic analyses of mature ZP2, ZP2 precursor (91 kd) and Endo H-treated ZP2 precursor (81 kd) suggest that there are six N-linked oligosaccharides per molecule and that the extreme heterogeneity of mature ZP2 is a consequence of the oligosaccharides and not the polypeptide chain itself.

Monoclonal antibodies which alter the morphology of cultured chick myogenic cells

Two monoclonal antibodies that cause changes in the morphology of cultured myogenic cells are described. Antibody JG9 causes myoblasts to round up and causes myotubes to become thin, cable-like structures with multiple round swellings. Antibody JG22 causes both myoblasts and myotubes to become round refractile cells poorly attached to the substratum. The effects of both antibodies are reversible. Fab fragments of JG22 can cause the morphological change. A tentative identification of the antigen recognized by JG22 is made.

Light chain diversity of murine anti-streptococcal antibodies: IgCH-linked effects on L chain expression

L chains derived from anti-group A streptococcal carbohydrate antibodies raised in A/J, BALB/cJ, C57BL/6J, CB-20, BAB-14, and CAL-20 mice were examined by isoelectric focusing. Multiple strain-associated differences in the degree and frequency of expression of particular L chain spectrotypes were observed. Analysis of L chain-focusing patterns in allotype-congenic mice revealed that IgCH-linked genes can have profound effects on the L chain phenotypes expressed by strains with identical L chain genotypes. Lastly, the overall spectrotypic diversity of L chains from anti-GAC antibodies appears to be less extensive than the diversity of the antibodies from which these L chains derive, documented by similar techniques. These results are interpreted in light of the significance of combinatorial diversity in generating antibody heterogeneity.