Influence of Backpack Carriage and Walking Speed on Muscle Synergies in Healthy Children

Four to five muscle synergies account for children's locomotion and appear to be consistent across alterations in speed and slopes. Backpack carriage induces alterations in gait kinematics in healthy children, raising questions regarding the clinical consequences related to orthopedic and neurological diseases and ergonomics. However, to support clinical decisions and characterize backpack carriage, muscle synergies can help with understanding the alterations induced in this condition at the motor control level. In this study, we investigated how children adjust the recruitment of motor patterns during locomotion, when greater muscular demands are required (backpack carriage). Twenty healthy male children underwent an instrumental gait analysis and muscle synergies extraction during three walking conditions: self-selected, fast and load conditions. In the fast condition, a reduction in the number of synergies (three to four) was needed for reconstructing the EMG signal with the same accuracy as in the other conditions (three to five). Synergies were grouped in only four clusters in the fast condition, while five clusters were needed for the self-selected condition. The right number of clusters was not clearly identified in the load condition. Speed and backpack carriage altered nearly every spatial-temporal parameter of gait, whereas kinematic alterations reflected mainly hip and pelvis adaptations. Although the synergistic patterns were consistent across conditions, indicating a similar motor pattern in different conditions, the fast condition required fewer synergies for reconstructing the EMG signal with the same level of accuracy.

Recent developments in muscle synergy analysis in young people with neurodevelopmental diseases: A Systematic Review

The central nervous system simplifies motor control by sending motor commands activating groups of muscles, known as synergies. Physiological locomotion can be described as a coordinated recruitment of four to five muscle synergies. The first studies on muscle synergies in patients affected by neurological diseases were on stroke survivors. They showed that synergies can be used as biomarkers for motor impairment as they vary in patients with respect to healthy people. Likewise, muscle synergy analysis has been applied to developmental diseases (DD). The need for a comprehensive view of the present findings is crucial for comparing results achieved so far and promote future directions in the field. In the present review, we screened three scientific databases and selected thirty-six papers investigating muscle synergies extracted from locomotion in children affected by DD. Thirty-one articles investigate how cerebral palsy (CP) influences motor control, the currently exploited method in studying motor control in CP and finally the effects of treatments in these patients in terms of synergies and biomechanics; two articles investigate how muscle synergies vary in Duchenne muscular dystrophy (DMD), and three other articles assess other developmental pathologies, such as chronic and acute neuropathic pain. For CP, most of the studies demonstrate that the number of synergies is lower and that the synergy composition varies in the affected children with respect to normal controls. Still, the predictability of treatment's effects and the etiology of muscle synergy variation are open questions, as it has been reported that treatments minimally modify synergies, even if they improve biomechanics. The application of different algorithms in extracting synergies might bring about more subtle differences. Considering DMD, no correlation was found between non-neural muscle weakness and muscle modules' variation, while in chronic pain a decreased number of synergies was observed as a possible consequence of plastic adaptations. Even if the potential of the synergistic approach for clinical and rehabilitation practices is recognized, there is not full consensus on protocols nor widely accepted guidelines for the systematic clinical adoption of the method in DD. We critically commented on the current findings, on the methodological issues and the relative open points, and on the clinical impact of muscle synergies in neurodevelopmental diseases to fill the gap for applying the method in clinical practice.

Effect of plano-valgus foot posture on midfoot kinematics during barefoot walking in an adolescent population

Background

Plano-valgus is a common alteration of the paediatric foot, characterized by valgus hindfoot, foot pronation and drop of the medial longitudinal arch. Despite their importance in the diagnosis and classification of plano-valgus foot condition, little information is available on functional alterations of the major joints spanning the medial longitudinal arch – i.e. midtarsal and tarso-metatarsal. Aim of the study was to provide objective description of the alterations in plano-valgus midfoot joints with respect to those in an age-matched normally-developed feet population.

Methods

Twenty adolescents (13.3 ± 0.8 years) with bilateral plano-valgus feet underwent clinical examination and were gait-analysed via a validated 4-segment foot model. This allowed to measure static foot posture, kinematics of the main foot joints, and medial longitudinal arch deformation during walking at comfortable speed. Range of motion and temporal profiles of joint rotations were compared to those from a control population of age-matched adolescents with normally-developed feet.

Results

The plano-valgus midtarsal joint was more dorsiflexed, everted and abducted than that in the control group, and showed reduced sagittal-plane RoM (plano-valgus = 15.9 degrees; control = 22.2 degrees; P <  0.01). The tarso-metarsal joint was more plantarflexed and adducted, and showed larger frontal-plane RoM. The MLA showed larger RoM and was lower throughout the stance phase of the gait cycle.

Conclusion

Significant postural and kinematic alterations are present at the midtarsal and tarso-metarsal joints of adolescents with plano-valgus feet. Objective identification and quantification of plano-valgus foot alterations, via non-invasive gait-analysis, is relevant to improving the diagnosis of this condition and to evaluating the effect of conservative treatments and of surgical corrections by different techniques.

Protein Carbonylation in Human Smokers and Mammalian Models of Exposure to Cigarette Smoke: Focus on Redox Proteomic Studies

SIGNIFICANCE

Oxidative stress is one mechanism whereby tobacco smoking affects human health, as reflected by increased levels of several biomarkers of oxidative stress/damage isolated from tissues and biological fluids of active and passive smokers. Many investigations of cigarette smoke (CS)-induced oxidative stress/damage have been carried out in mammalian animal and cellular models of exposure to CS. Animal models allow the investigation of many parameters that are similar to those measured in human smokers. In vitro cell models may provide new information on molecular and functional differences between cells of smokers and nonsmokers. Recent Advances: Over the past decade or so, a growing number of researches highlighted that CS induces protein carbonylation in different tissues and body fluids of smokers as well as in in vivo and in vitro models of exposure to CS.

CRITICAL ISSUES

We review recent findings on protein carbonylation in smokers and models thereof, focusing on redox proteomic studies. We also discuss the relevance and limitations of these models of exposure to CS and critically assess the congruence between the smoker's condition and laboratory models.

FUTURE DIRECTIONS

The identification of protein targets is crucial for understanding the mechanism(s) by which carbonylated proteins accumulate and potentially affect cellular functions. Recent progress in redox proteomics allows the enrichment, identification, and characterization of specific oxidative protein modifications, including carbonylation. Therefore, redox proteomics can be a powerful tool to gain new insights into the onset and/or progression of CS-related diseases and to develop strategies to prevent and/or treat them. Antioxid. Redox Signal. 26, 406-426.

Knee arthrodesis by the Ilizarov method in the treatment of total knee arthroplasty failure

BACKGROUND

Currently, the main indication for knee arthrodesis is septic failure of a total knee arthroplasty (TKA). The purpose of this study was to evaluate the results of knee arthrodesis by circular external fixation performed in the treatment of TKA failure in which revision arthroplasty was not indicated.

METHODS

The study involved 19 patients who underwent knee arthrodesis by the Ilizarov method. Clinical and functional assessments were performed, including Knee Society Score (KSS). A postoperative clinical and radiographic evaluation was conducted every three months until the end of the treatment. Postoperative complications and eventual leg shortening were recorded.

RESULTS

KSS results showed a significant improvement with respect to the preoperative condition. Of the 16 patients in the final follow-up, 15 patients (93.7%) achieved complete bone fusion. Major complications occurred in patients treated for septic failure of TKA and most occurred in patients over 75years of age; the mean final leg shortening was four centimeters.

CONCLUSION

In our experience, the Ilizarov method is effective for performing a knee arthrodesis in the case of extensive bone loss. At the same time, it is possible to correct the associated leg deformities or limb length difference. In addition, only the Ilizarov method provides a mechanical stimulus for bone formation and improves the quality of the bone and of the microcirculation, which enhances the host response against infection. Despite these attributes, knee arthrodesis by the Ilizarov method must be considered a 'salvage procedure' in cases of severe outcomes from knee surgery in which revision arthroplasty is not indicated.

I.S.Mu.L.T - Rotator Cuff Tears Guidelines

Despite the high level achieved in the field of shoulder surgery, a global consensus on rotator cuff tears management is lacking. This work is divided into two main sessions: in the first, we set questions about hot topics involved in the rotator cuff tears, from the etiopathogenesis to the surgical treatment. In the second, we answered these questions by mentioning Evidence Based Medicine. The aim of the present work is to provide easily accessible guidelines: they could be considered as recommendations for a good clinical practice developed through a process of systematic review of the literature and expert opinion, in order to improve the quality of care and rationalize the use of resources.

Prevalence of Associated Lesions in Anterior Cruciate Ligament Reconstruction: Correlation With Surgical Timing and With Patient Age, Sex, and Body Mass Index

BACKGROUND

Knee instability resulting from anterior cruciate ligament (ACL) rupture is an important risk factor for the onset of meniscal tears and cartilage injuries. A delay of the ligament reconstruction further increases this risk. There is currently no agreement on the right time for surgical ACL reconstruction.

PURPOSE

To verify the correlation of time to ACL reconstruction, patient age, sex, and body mass index (BMI) with the prevalence of meniscal tears and cartilage injuries, as well as to identify the proper surgical timing to decrease the risk of developing associated injuries.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The medical records of 988 patients who underwent primary ACL reconstruction between January 2010 and May 2014 were analyzed to collect data on the prevalence of meniscal tears and cartilage injuries, surgical timing, and patient sex, age, and BMI. Logistic regression was performed to estimate the association between the prevalence of intra-articular lesions and the independent variables of surgical timing, sex, age, and BMI.

RESULTS

The risk of developing at least an associated lesion increased by an average of 0.6% for each month of delay of surgical reconstruction. The odds ratio (OR) for developing an intra-articular lesion was 1.989 (95% CI, 1.403-2.820) in those waiting more than 12 months for ACL reconstruction. A 12-month delay for the intervention nearly doubled the risk of developing a medial meniscal tear (OR, 1.806 [95% CI, 1.317-2.475]) but did not modify the risk for the lateral meniscus (OR, 1.183 [95% CI, 0.847-1.653]). Concerning cartilage lesions, the risk after a 12-month delay increased in the medial compartment (femoral condyle: OR, 2.347 [95% CI, 1.499-3.676]; tibial plateau: OR, 5.574 [95% CI, 1.911-16.258]). In the lateral femoral condyle, the risk became significant in patients who underwent surgery more than 60 months after ACL injury as compared with those treated in the first 3 months (OR, 5.949 [95% CI, 1.825-19.385]). Lateral tibial plateau lesions did not seem to increase significantly. Male sex was a risk factor for the onset of lateral meniscal tears (OR, 2.288 [95% CI, 1.596-3.280]) and medial tears (OR, 1.752 [95% CI, 1.280-2.399]). Older age (OR, 1.017 [95% CI, 1.006-1.029]) and increased BMI (OR, 1.120 [95% CI, 1.072-1.169]) were risk factors for the occurrence of at least 1 associated lesion.

CONCLUSION

ACL reconstruction within 12 months of injury can significantly reduce the risk of meniscal tears and chondral lesions. The close association between BMI and prevalence of associated lesions suggests that attention be paid to patients with an elevated BMI when considering the timing of ACL reconstruction surgery.

Modifying the Rizzoli foot model to improve the diagnosis of pes-planus: application to kinematics of feet in teenagers

BACKGROUND

A number of multi-segment foot protocols have been proposed to obtain measurements of clinical value. In the clinical assessment of foot pathologies and deformities, such as in the pes-planus, the frontal-plane alignment of the calcaneus and the dynamic properties of the medial longitudinal arch are critical parameters though often neglected by the majority of foot protocols. The aim of the present work is to modify an established foot protocol to obtain static and kinematic measures more consistent with corresponding clinical observations. Moreover, while many papers have reported kinematic data from varying populations, few investigations have focussed on young participants from same-age cohorts.

METHODS

A 6-camera motion capture system was employed to track the shank, rear-, mid- and fore-foot segments in the left and right leg of 10 children (13.1 ± 0.8 years) during gait. Three markers were attached to each segment thus allowing for triplanar motion of five joints to be described according to the Rizzoli Foot Model. An additional marker was attached to the posterior bottom of the calcaneus to enhance measurement of frontal-plane orientation. Description of the medial longitudinal arch angle was redefined to be more consistent with rearfoot orientation and to common clinical assessments. A novel 3-marker description of the hallux segment was implemented to improve robustness in calculating 1(st) metatarso-phalangeal joint rotations.

RESULTS

Foot segments kinematics showed good inter- participant repeatability and overall consistency with previous similar reports. 15 out of 20 feet showed neutral or slightly valgus orientation of the calcaneus. Relatively large medial longitudinal arch angles (mean 186 ± 16 deg) were found in the present young population. Both measurements were reasonably in accordance with the relevant clinical observations of these feet.

CONCLUSIONS

Modifications to a widely used multisegmental foot kinematic model were implemented to improve robustness and consistency with relevant clinical observations. A detailed description of foot joints motion during barefoot walking in a population of 13-year old children with apparent flat feet has been presented, which may provide useful information to investigate the development of gait in children and the diagnosis of flexible flat foot.

A central role for intermolecular dityrosine cross-linking of fibrinogen in high molecular weight advanced oxidation protein product (AOPP) formation

BACKGROUND

Advanced oxidation protein products (AOPPs) are dityrosine cross-linked and carbonyl-containing protein products formed by the reaction of plasma proteins with chlorinated oxidants, such as hypochlorous acid (HOCl). Most studies consider human serum albumin (HSA) as the main protein responsible for AOPP formation, although the molecular composition of AOPPs has not yet been elucidated. Here, we investigated the relative contribution of HSA and fibrinogen to generation of AOPPs.

METHODS

AOPP formation was explored by SDS-PAGE, under both reducing and non-reducing conditions, as well as by analytical gel filtration HPLC coupled to fluorescence detection to determine dityrosine and pentosidine formation.

RESULTS

Following exposure to different concentrations of HOCl, HSA resulted to be carbonylated but did not form dityrosine cross-linked high molecular weight aggregates. Differently, incubation of fibrinogen or HSA/fibrinogen mixtures with HOCl at concentrations higher than 150 μM induced the formation of pentosidine and high molecular weight (HMW)-AOPPs (>200 k Da), resulting from intermolecular dityrosine cross-linking. Dityrosine fluorescence increased in parallel with increasing HMW-AOPP formation and increasing fibrinogen concentration in HSA/fibrinogen mixtures exposed to HOCl. This conclusion is corroborated by experiments where dityrosine fluorescence was measured in HOCl-treated human plasma samples containing physiological or supra-physiological fibrinogen concentrations or selectively depleted of fibrinogen, which highlighted that fibrinogen is responsible for the highest fluorescence from dityrosine.

CONCLUSIONS

A central role for intermolecular dityrosine cross-linking of fibrinogen in HMW-AOPP formation is shown.

GENERAL SIGNIFICANCE

These results highlight that oxidized fibrinogen, instead of HSA, is the key protein for intermolecular dityrosine formation in human plasma.

To fix or not to fix? The role of fibular fixation in distal shaft fractures of the leg

BACKGROUND

The role of stabilisation of the fibula in distal two-bone fractures of the leg is controversial. Some studies indicate the need for fibular stabilisation in 43 AO fractures, but few studies consider the role of the fibula in 42 AO fractures. The aim of the current paper is to explain the role of stabilisation of the fibula in 42 AO fractures, correlating the rates of healing and non-union between patients with and without fibula fixation.

MATERIALS AND METHODS

A total of 60 patients with 42 AO (distal) shaft fracture of the tibia with associated fracture of the fibula were selected. Patients were divided into two groups according to whether or not the fibula was fixed: Group I (n=26) comprised patients who had their fibula fixed while Group II (n=34) comprised patients who did not. The fibular fracture was classified according to the AO and related to the level of the tibial fracture. Other parameters examined were the union rate of the two groups correlated to the fracture pattern and position of the fibular fracture; the demographic data, such as age and gender; the presence of an open fracture, and the type of tibial fixation device used (nail or plate).

RESULTS

None of the parameters considered (open injury, AO classification, device used and level of the fibular fracture relative to the tibial) were shown to have an influence on the development of a non-union.

CONCLUSION

This study showed a higher non-union rate when the fracture of the tibia and fibula were at the same level, the tibia was fixed with a bridging plate and the fibula left untouched. For this reason, we recommend fibular fixation in all 42 distal fractures when both fractures lie on the same plane and the tibial fracture is relatively stabilised.

Cigarette smoke induces alterations in the drug-binding properties of human serum albumin

Albumin is the most abundant plasma protein and serves as a transport and depot protein for numerous endogenous and exogenous compounds. Earlier we had shown that cigarette smoke induces carbonylation of human serum albumin (HSA) and alters its redox state. Here, the effect of whole-phase cigarette smoke on HSA ligand-binding properties was evaluated by equilibrium dialysis and size-exclusion HPLC or tryptophan fluorescence. The binding of salicylic acid and naproxen to cigarette smoke-oxidized HSA resulted to be impaired, unlike that of curcumin and genistein, chosen as representative ligands. Binding of the hydrophobic fluorescent probe 4,4'-bis(1-anilino-8-naphtalenesulfonic acid) (bis-ANS), intrinsic tryptophan fluorescence, and susceptibility to enzymatic proteolysis revealed slight changes in albumin conformation. These findings suggest that cigarette smoke-induced modifications of HSA may affect the binding, transport and bioavailability of specific ligands in smokers.

New insights in extracellular matrix remodeling and collagen turnover related pathways in cultured human tenocytes after ciprofloxacin administration

We characterized the effect of ciprofloxacin (CPX) in cultured human tenocytes by morphological and molecular methods. Collagen type I and III mRNA and protein levels were unaffected, but lysyl hydroxylase 2b mRNA levels progressively decreased after CPX administration. MMP-1 protein levels significantly increased after 20 μg/ml CPX administration but remained unmodified at the higher dose, whilst MMP-2 activity was unchanged. Tissue inhibitor of MMP (TIMP-1) gene expression decreased after CPX treatment, whilst TIMP-2 and transforming growth factor-β1 gene expression, the cytoskeleton arrangement, and cytochrome c expression remained unmodified. Secreted Protein Acidic and Rich in Cysteine mRNA and protein levels remained almost unchanged, whilst N-cadherin mRNA levels resulted significantly down-regulated and connexin 43 gene expression tended to decrease after CPX administration. The CPX-induced decreased ability to cross-link collagen and decreased TIMP-1 levels, possibly leading to higher activity of MMPs in ECM degradation, together with the down-regulation of N-cadherin and connexin 43 are consistent with a reduced ability to maintain tissue homeostasis, possibly making the tendon more susceptible to rupture.

Arthroscopic stabilization of the shoulder in adolescent athletes participating in overhead or contact sports

PURPOSE

To investigate the outcome of arthroscopic capsular repair for shoulder instability in an active adolescent population participating in overhead or contact sports.

METHODS

We identified 67 patients (aged 13 to 18 years) with post-traumatic recurrent shoulder instability for inclusion in the study from our computer database. Of these patients, 65 (96%) were available for clinical review. There were 44 male and 21 female patients, with a mean age of 16 years at the time of surgery. All patients participated in overhead or contact sports at a competitive level. Arthroscopic capsulolabral repair was performed after at least 6 months of failed nonoperative treatment. The mean follow-up was 63 months. Shoulder range of motion and functional outcomes were measured preoperatively and postoperatively with Single Assessment Numeric Evaluation (SANE), Rowe, and American Shoulder and Elbow Surgeons (ASES) scores. Furthermore, type of sport, time until surgery, and number of dislocations were analyzed from our database to find any correlation with the recurrence rate.

RESULTS

At final follow-up, the mean SANE score was 87.23% (range, 30% to 100%) (preoperative mean, 46.15% [range, 20% to 50%]); the mean Rowe score was 85 (range, 30 to 100) (preoperative mean, 35.9 [range, 30 to 50]); and the mean ASES score was 84.12 (range, 30 to 100) (preoperative mean, 36.92 [range, 30 to 48]). The mean forward flexion and external rotation with the arm at 90° abduction did not change from preoperative values; 81% of the patients returned to their preinjury level of sport, and the rate of failure was 21%. The recurrence rate was not related to the postoperative scores (P = .556 for SANE score, P = .753 for Rowe score, and P = .478 for ASES score), the number of preoperative episodes of instability (P = .59), or the time from the first instability episode to the time of surgery (P = .43). There was a statistically significant relation (P = .0021) between recurrence and the type of sport practiced. Recurrence rate was related to the type of sport practiced.

CONCLUSIONS

Arthroscopic stabilization is a reasonable surgical option even in an adolescent population performing sports activities. However, it must be emphasized to the patients and their relatives that the recurrence rate that could be expected after an arthroscopic procedure is higher than in the adult population.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Red blood cells protect albumin from cigarette smoke-induced oxidation

Different studies reported the presence of oxidized (carbonylated) albumin in the extravascular pool, but not in the intravascular one of cigarette smokers. In this study we attempted to explain this apparent discrepancy exposing human serum albumin (HSA) to aqueous cigarette smoke extract (CSE). CSE induces HSA carbonylation and oxidation of the HSA Cys34 sulfhydryl group. An antioxidant action of glutathione, cysteine, and its synthetic derivative N-acetylcysteine was observed only at supra-physiological concentrations, suggesting that physiological (plasma) concentrations of glutathione and cysteine in the low micromolar range are ineffective in preventing cigarette smoke-induced oxidation of HSA. Differently, human erythrocytes resulted to be protective towards CSE-induced oxidation (carbonylation and thiol oxidation) of both HSA and total human plasma proteins.

Effects of aging and cyclosporin a on collagen turnover in human gingiva

Background:

We aimed at characterizing the aging gingiva analyzing: i) collagen content and turnover in human gingival tissues and fibroblasts obtained from healthy young and aging subjects. ii) the effect of cyclosporin A administration in human cultured gingival fibroblasts obtained from aging compared to young subjects.

Methods:

Morphological analysis was performed on haematoxylin-eosin and Sirius red stained paraffin-embedded gingival biopsies from young and aging healthy subjects. The expression of the main genes and proteins involved in collagen turnover were determined by real time PCR, dot blot and SDS-zymography on cultured young and aging gingival fibroblasts, and after cyclosporin A administration.

Results:

Our results suggest that in healthy aged people, gingival connective tissue is characterized by a similar collagen content and turnover. Collagen turnover pathways are similarly affected by cyclosporin A treatment in young and aging gingival fibroblasts.

Conclusions:

Cyclosporin A administration affects gingival collagen turnover pathways in young and aging fibroblasts at the same extent, suggesting that during aging cyclosporin A administration is not related to relevant collagen turnover modifications.

D.D.S.H.: developmental dysplasia of the spastic hip: strategies of management in cerebral palsy. A new suggestive algorithm

Hip problems in cerebral palsy are relatively frequent (25-75%). Subluxation and dislocation of the hip is proportional to the neuromuscular involvement and is often due to alteration caused by spastic muscle forces acting on the femoral head in the acetabular cavity. The EMMA approach (Early Multilevel Minimally-invasive Approach) has been designed to restore muscle balance, decrease hip migration and prevent bone deformities thereby avoiding future pain with minimal biological cost to the patient. EMMA is suitable for most patients, especially those with increased tone, poor muscle control and selectivity, Reimer Index (R.I.) 20%. We consider age and R.I crucial prerequisites for treatment steps. EMMA 1) age 2-4 years, RI 20%: multilevel injection of botulinum toxin in case of muscular hyperactivity without morphological alterations of the couple muscle-tendon (contractures). EMMA 2) age 4-6, RI 20%: multilevel aponeurectomies in case of muscular hyperactivity with morphological alterations of the couple muscle-tendon (retraction). EMMA 3) early bone surgery (growth plates). This approach has been adopted in the last 4 years to prevent bone deformities and give early mobilisation and early control of the pain. EMMA is simple to apply even in infants, both for hip containment and to decrease spasticity.

Slipped Upper Femoral Epiphysis (SUFE): to do or not to do in sufe

Slipped upper femoral epiphysis (SUFE) is not an uncommon hip disease in adolescence. Usually, diagnosis of SUFE is delayed, has high risk of sequela and poor long-term results. This paper reviews the literature with a focus on epidemiology, aetiology, diagnosis, treatment and results regarding SUFE.

Expression profiling of genes involved in collagen turnover in tendons from cerebral palsy patients

Cerebral palsy (CP) is a nonprogressive central nervous system lesion clinically characterized by impairment of voluntary movement related to spasticity, time of activation, and strength of skeletal muscle. Altered muscular control may act on tendon structure and influence extracellular matrix homeostasis, in particular, collagen. The effect of spasticity on collagen turnover in CP patients' tendons has not been described previously. We studied collagen turnover related genes in the gracilis and semitendinosus tendons of diplegic (n = 6) and quadriplegic (n = 15) patients, compared to normal subjects (n = 7). In particular, using real time RT-PCR, we analyzed the mRNA levels of the major extracellular matrix (ECM) components collagen type I (COL-I, alpha 2 chain COL1A2), the matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of MMP (TIMP-1), the enzyme responsible for collagen maturation lysyl hydroxylase 2b (LH2b), of the matricellular protein involved ECM remodelling (secreted protein acidic and rich in cysteine, SPARC), and the transforming growth factor-beta1 (TGF-beta1), a multipotent cytokine involved in collagen turnover. Our results show that gene expression profiles are quite different in CP samples compared to normal ones. In fact, spasticity induces relevant modifications of tendons at the molecular level, which modify their phenotypes to respond to the higher mechanical loading and increased functional demands. Interestingly, hypertonic quadriplegic subjects displayed the highest mRNA levels of COL1A2, LH2b, TGF-beta1, and SPARC, suggesting that their tendons undergo higher mechanical loading stimulation.

The pituitary tumor transforming gene 1 (PTTG-1): an immunological target for multiple myeloma

Background

Multiple Myeloma is a cancer of B plasma cells, which produce non-specific antibodies and proliferate uncontrolled. Due to the potential relapse and non-specificity of current treatments, immunotherapy promises to be more specific and may induce long-term immunity in patients. The pituitary tumor transforming gene 1 (PTTG-1) has been shown to be a novel oncogene, expressed in the testis, thymus, colon, lung and placenta (undetectable in most other tissues). Furthermore, it is over expressed in many tumors such as the pituitary adenoma, breast, gastrointestinal cancers, leukemia, lymphoma, and lung cancer and it seems to be associated with tumorigenesis, angiogenesis and cancer progression. The purpose was to investigate the presence/rate of expression of PTTG-1 in multiple myeloma patients.

Methods

We analyzed the PTTG-1 expression at the transcriptional and the protein level, by PCR, immunocytochemical methods, Dot-blot and ELISA performed on patient's sera in 19 multiple myeloma patients, 6 different multiple myeloma cell lines and in normal human tissue.

Results

We did not find PTTG-1 presence in the normal human tissue panel, but PTTG-1 mRNA was detectable in 12 of the 19 patients, giving evidence of a 63% rate of expression (data confirmed by ELISA). Four of the 6 investigated cell lines (66.6%) were positive for PTTG-1. Investigations of protein expression gave evidence of 26.3% cytoplasmic expression and 16% surface expression in the plasma cells of multiple myeloma patients. Protein presence was also confirmed by Dot-blot in both cell lines and patients.

Conclusion

We established PTTG-1's presence at both the transcriptional and protein levels. These data suggest that PTTG-1 is aberrantly expressed in multiple myeloma plasma cells, is highly immunogenic and is a suitable target for immunotherapy of multiple myeloma.

[Persistent coxalgia in the child. The value of magnetic resonance]

This study was aimed at assessing the Magnetic Resonance (MR) features of persistent hip pain in children. Twenty-six patients aged 1.6 to 15.2 years (mean: 6.5 years) were clinically selected for the study; at clinics, all patients had persistent hip pain after 10 days' therapy. All patients were examined with radiography, US and MRI at 0.5 T. SE T1-weighted sequences, with and without fat suppression (FS), SE T2-weighted and gradient echo (GE) T1-weighted-like (T1*) sequences were acquired on the coronal plane. Slices were 5 and 3 mm thick on SE and GE T1* sequences, respectively. Morphology and signal intensity of epiphysis, growth plate and metaphysis were prospectively studied with MRI. Clinical and/or imaging follow-up (3 months) was the reference standard in our study. Final diagnoses were: no evidence of alteration (n = 3), transient synovitis (n = 6), rheumatic fever (n = 3), Perthes' disease (n = 7), Meyer's dysplasia (dysplasia epiphysealis capitis femoris, DECF) (n = 2), early slipped capital femoral epiphysis (n = 2), incomplete fracture (n = 1), extraarticular cause of pain (muscular abscess, osteomyelitis) (n = 2). In 23 of 26 patients MRI confirmed clinical, radiographic and US findings. MRI was particularly helpful in making an unquestionable diagnosis in the other 3 cases; in a patient with suspected slipped capital femoral epiphysis MRI revealed an incomplete fracture, in a patient with suspected Meyer's dysplasia MRI revealed early Perthes' disease and finally in a patient with suspected transient synovitis MRI revealed Perthes' disease. To conclude, MRI allows the condition causing persistent hip pain to be assessed and accurately depicted, integrating clinical, radiographic and US findings and in some cases also changing diagnosis and therapy.

Red cell aging and active calcium transport

The authors have investigated the relationships between the active calcium transport across the human red blood cell (RBC) membrane and the RBC aging processes in vivo and in vitro. For the study of this biological system, the authors have determined the active calcium uptake by inside-out membrane vesicles obtained from selected RBC populations. This model provided an optimal way to assess the biochemical and functional responses of the human cell to the oxidative stimulus triggered by the cellular aging processes. The activity of the calcium pump is indeed strictly correlated to the oxidative damage suffered by the RBC, being higher in the aged RBC. It appears that the main controller of the active calcium transport is the age-dependent protein inhibitor of the calcium pump.

The effect of in vitro and in vivo cellular aging on the active calcium transport in human inside-out red cell membrane vesicles

Modelling of the in vivo and in vitro aging processes in the human red cell has stressed the following features of the active calcium uptake by inside-out vesicles: 1) it is higher in the outdated, in vitro aged, than in the fresh red cell (p less than 0.0005), and in the densest, in vivo aged fraction than in the lightest, young fraction (p = 0.08); 2) it increases following stimulation by excess calmodulin to values that are not significantly different; 3) it decreases to the same value in the absence of endogenous calmodulin and inhibitor, with and without exogenous calmodulin; 4) it is the target of a non-competitive inhibition, that is stronger in the fresh than in the outdated red cell. We conclude that the aging process does not involve neither membrane Ca-ATPase nor calmodulin, but rather the interaction of the calcium pump with the inhibitor of Ca-ATPase.