Ag surface diffusion and out-of-bulk segregation in CrN-Ag nano-composite coatings.

CrN-Ag nanocomposite coatings are deposited on Si(100) wafers and 20MnCr5 steel disks in a mixed Ar+N2 atmosphere by reactive magnetron sputtering. Structure, composition and morphology were investigated by Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), X-ray Photoemission Spectroscopy (XPS), X-ray Diffraction (XRD) and Focused Ion Beam (FIB) cross sectional analysis. The as deposited film matrix is mainly composed by CrN phase (78%), but a relevant part (28%) is composed by Cr2N. Ag agglomerates in the CrN matrix forming elongated grains 200-400 nm wide and 50-100 nm high, which extends on the top of CrN columns. At the surface Ag aggregates into two different structures: large tetrahedral crystalline clusters, with typical dimension ranging from 200 to 500 nm, and smaller Ag nanoparticles with diameter of 15-25 nm. The annealing in N2 atmosphere up to 500 degrees C does not affect size and distribution of the Ag grains in the sub-surface region, while it induces a size increase of the bigger Ag clusters on the surface, mainly related to Ag surface diffusion and clusters coalescence. Annealing at higher temperature leads to an evident Ag out-of-bulk segregation, generating Ag depleted voids in the near-surface region, and further increasing of the Ag clusters size at the surface. Tribological tests on as deposited CrN-Ag film reveal a coefficient of friction against a steel ball reduced with respect to CrN film, probably related to the presence of Ag which acts as solid lubricant, but the coating is removed after a very short sliding distance. The poor mechanical properties of the realized Ag-based coatings are confirmed by lower hardness and Young modulus values with respect to pure CrN.

Multifrequency bioelectric impedance measurements for predicting body water compartments in duchenne muscular dystrophy.

Body hydration and extra- to intra-cellular water ratio (ECW: ICW) have been studied in 12 duchenne muscular dystrophy (DMD) patients and 15 healthy controls. Subjects underwent total body water (TBW) and extracellular water (ECW) assessment by deuterium and bromide dilution, respectively. Multifrequency bioelectric impedance analysis (MFBIA) was performed on all subjects with the aim to establish its accuracy in predicting TBW and ECW in DMD. Body hydration was lower (51.8 +/- 2.8 vs 58.5 +/- 5.9%, P < 0.01) and the ECW: ICW ratio higher (1.15 +/- 0.25 vs 0.70 +/- 0.23, P < 0.001) in DMD than in control subjects. Hence, control-generated formulae for predicting TBW and ECW from MFBIA gave inaccurate results in DMD subjects. Population-specific formulae were developed to obtain an accurate prediction of body water compartments in DMD patients.

Long-term results of spine surgery in Duchenne muscular dystrophy.

We report the long-term orthopaedic and functional results of segmental spinal instrumentation and fusion in 30 Duchenne patients. Twenty-nine had a mean 59% correction of scoliosis with post-operative immobilization in a brace of only three months on average and with a very limited loss of correction over time. One died after cardiac arrest. The mean vital capacity preoperatively was 57 +/- 17% with a decrease to 34 +/- 13% at 3.9 +/- 2 yr after surgery. The sitting position, aesthetic improvement and the quality of life after spinal fusion have been positively evaluated by the large majority of the patients and their parents. Head control was lost in the 14 patients who developed a more severe extension contracture of the neck measured as a significantly longer chin-sternum distance. More than 90% would have the operation or would give their consent again for their son having the operation.

Bethlem myopathy: early-onset benign autosomal dominant myopathy with contractures. Description of two new families.

Bethlem myopathy is an apparently rare early-onset benign autosomal dominant limb-girdle myopathy with contractures of the fingers. To determine whether this disorder is unrecognized rather than rare we used muscle computerized tomography (CT) and isokinetic muscle testing and assiduously sought contractures of the fingers in relatives of two patients with the disease. CT showed that muscle impairment was mild but more diffuse than clinically apparent and showed an unexpected progressive degeneration of lumbar paravertebral muscles. The isokinetic test showed that the quadriceps was more involved that the hamstrings. In addition we found that contractures of the last four fingers progressed centripetally with age from the distal interphalangeal joints to the wrist. As a result we proved that 15 of the 21 examined subjects had the disease, 7 of them being unaware that anything was amiss. Careful examination may reveal that Bethlem myopathy is more common than is now thought.

Morphological and structural characteristics of the myopathic bone.

The aim of the present paper was to study the myopathic bone both from the morphological and structural viewpoints. To this end, samples from 8 patients affected by different neuromuscular diseases (DMD, SMA and CMD) have been examined. Thus, by SEM analysis a quantitative reduction of the trabeculae and an increase in porosity of the myopathic bone were found and also, by diffractometric analysis, the presence of pathologic crystalline phases (beta-TCP and beta-TCP-Mg).

Spine surgery in spinal muscular atrophy: long-term results.

Fifteen patients with spinal muscular atrophy operated on for scoliosis were reviewed and interviewed. Age at time of surgery averaged 16 yr. Follow-up averaged more than 5 yr. Eleven patients underwent posterior spinal fusion with Luque instrumentation. Four had Harrington instrumentation, with segmental wiring in three. Three out of the 15 also had anterior fusion with Dwyer instrumentation. Patients were immobilized in cast or brace for 6 months, on average, after surgery. The average curve correction was 50%. There was a loss of vital capacity after the operation, which in most cases was regained with time. In functional terms, there were improvements and deteriorations both in the short and long term. Esthetic appearance improved in all patients, as did the perceived well-being. Retrospectively all but one would have the operation again.

Rigid spine syndrome and rigid spine sign in myopathies.

We studied eight patients with rigid spine syndrome aged 8 to 20 years at the time of first examination. Muscle weakness, rigid spine, and flexion contracture of elbows and ankles were noted in the first 6 years of age. Radiological study of the cervical spine revealed considerable reduction not only of flexion, but also of extension, of the neck. The "alligator sign" was demonstrated. Progression of scoliosis and of contractures reduced the functional capacity in six patients. A restrictive ventilatory syndrome was observed in all, while central apneas with oxygen desaturation were shown in two. Cardiac arrhythmias were observed in four. We suggest that a distinction should be made between myopathic rigid spine and rigid spine syndrome. Myopathic rigid spine is a clinical sign which is rarely sought but is present in several types of well-defined myopathies, meaning the myopathic involvement of the extensor muscles of the spine. Rigid spine syndrome is an axial myopathy with peculiar clinical and radiographic signs and a characteristic natural history.

Growth hormone evaluation in Duchenne muscular dystrophy.

Growth hormone (GH) release with pharmacological tests and sleep test, somatomedin C and auxological features were studied in 10 patients affected by Duchenne Muscular Dystrophy. GH release in these patients seems to be lower than normal; moreover some of them are of short stature without an evident relationship with GH deficit. The possible significance of the data obtained is discussed, particularly in relation to the clinical course of the disease, and to current therapeutic trials with a GH release inhibitor (mazindol).

In vivo isotope study of the thyroid with 99mTcO4- in neonatal congenital hypothyroidism.

Seventeen patients, screened from a neonatal programme for hypothyroidism were studied. As well as the scintigraphic investigations, serum TSH, T3, free T3, T4, free T4, and TBG were measured in all patients. Not more than 11.1 MBq (300 microCi) 99mTcO4- was administered IV. A gamma camera with a parallel-hole collimator on line with the computer was used. The method allowed good statistics to be obtained in 5-10 min in a wide field of exploration, thus reducing the problems of positioning and prolonged immobilization of the young patient. The data collected in the computer were elaborated to define better the characteristics of the thyroid image. This kind of in vivo study introduced into a screening programme, enables an 'anatomic' diagnosis of the defect to be obtained before starting the therapy. This is undoubtedly valuable from the epidemiological point of view, enables early determination of the degree of thyroid insufficiency, and contributes to the formulation of a prognosis based on the degree and on the moment in which prenatal harm occurred.