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Biomedical subjects

L de Palma

Publications and source records attributed to L de Palma.

25 records · Page 2Linked to original sources
PubMedDate not supplied

Muscle involvement in rheumatoid arthritis: an ultrastructural study.

An electron microscopic investigation has been carried out on muscle bioptic samples from patients affected by rheumatoid arthritis (RA). This study was undertaken to seek further ultrastructural alterations affecting striated muscles in RA pathology. Bioptic samples were collected on a total of 30 surgical interventions of hip (10), knee (8), and foot (12). This yielded three muscle types: gluteus maximus, vastus lateralis, and extensor digitorum communis. Muscle samples from 12 patients with no RA stigmata, selected to match RA patients by age and gender, constituted the control group. Tissue samples were prepared both for conventional histochemical methods and according to conventional electron microscopic procedures, including morphometric analysis. Although to a different extent in each sample, in muscles from RA vs. controls the authors observed the simultaneous presence of discrete muscular alterations such as wider separation of myofibrils, myelin figures, dilated sarcotubular system, pleomorphic mitochondria, myofibril flaking, and lipofuscin deposition in the subsarcolemmal region. In addition to a progressive atrophy, the above findings are suggestive of rheumatoid myositis and lend further support to the still poorly documented presence of an idiopathic inflammatory myopathy and inclusion body myositis associated with RA.

Adult↗
PubMedDate not supplied

Growth-plate cartilage metabolic response to mechanical stress.

An in vitro study assessing the metabolic response of growth-plate cartilage explants to mechanical stress was performed. Cultured explants were exposed to two types of stress: (a) single high-compressive force (SHC), and (b) multiple intermittent low-compressive force (MILC). Proliferative activity and matrix synthesis were determined with liquid scintillation counting after explants were labeled with [3H]thymidine and [35S]-sulfate. Our in vitro findings suggest that too high a force, even acting for a short time, may result in permanent injury of growth plate cartilage. Hence, we hypothesized that there might be an unknown pathogenetic mechanism of Salter's fifth-type epiphyseal injury. We report the results of our study.

Animals↗
PubMedDate not supplied

Coxa pedis dysplasia in congenital convex pes valgus.

A dissection was carried out on bilateral congenital convex pes valgus in a newborn who died of congenital visceral malformations. The main finding was a modification in the neck-body relations of the talus. Nearly all muscles showed morphologic alterations. No insertional or histologic anomalies were shown. The plantar calcaneonavicular ligament was stretched and attenuated. The alterations observed in our case affected all the anatomic structures forming and stabilizing the coxa pedis. Our case suggests that the dysplastic evolution of the talar body-neck angle halts, and the neck assumes an adducted, medially inclined and plantar-tilted angle with respect to the talar body. We propose the term "congenital dysplasia of the coxa pedis" to describe this condition, because it emphasizes the primary alteration in the morphogenesis of the talocalcaneonavicular joint.

Abnormalities, Multiple↗
PubMedDate not supplied

Histological study of the phalangeal articular side following Keller procedure for hallux valgus.

Through a histological study, the authors have examined the coating tissue at the base of the proximal phalanx of the hallux. This study concerns five females who have undergone an operation according to Keller technique, and necessitated a reoperation for unsatisfactory results at the first operation. The study proves that resection of the phalanx leads, in time, to the formation of a coating fibrous cartilage. Such layer tends to reproduce a structure that is similar to an articulation, even though missing a hyaline cartilage. This microscopical structure supports well the load that is directed along the perpendicular axis of the phalanx, preserving, in time, a sufficient gliding capacity between the two surfaces, with optimal limitation of the natural wear-out process.

Aged↗
PubMedDate not supplied

Foot alterations in the hemodialyzed patient.

On the basis of their experience, the authors refer to complications observable at the foot level in chronic uremic patients in long-term hemodialytic treatment. These complications, termed renal osteodystrophy, are attributed to alterations in the phosphocalcium metabolism and to hyperparathyroidism. From an anatomopathologic viewpoint, they are characterized by alteration in bone tissue (osteomalacia and/or fibrous osteitis) and by soft tissue alterations. Alterations in the foot are the same as those observed in other osteoarticular regions. They consist of bone subperiosteal reabsorption of the phalanges, vascular calcifications, articular and para-articular calcifications, spontaneous disinsertion of the Achilles tendon and peripheral canalicular neuropathies specifically represented by the tarsal tunnel syndrome. Another complication of this pathology is represented by "Calciphylaxis," characterized by calcifications of the middle tunica of arteries and small arteries, by ulcerations and tissue necrosis at the foot level.

Chronic Kidney Disease-Mineral and Bone Disorder↗
PubMedDate not supplied

Fibrillogenesis in tendon healing: an experimental study.

The aim of this study was the histochemical, immunohistochemical and ultrastructural analysis of reparative fibrillogenesis in experimental lesions of Achilles' tendon. Subtotal tenotomy of Achilles' tendon was performed in twenty Wistar rats. The scar tissue was analysed 2, 4, 7, 14, 21, 30, 45 and 60 days post-operatively. Histochemical, (resorcin-fuchsin, aldehyde-fuchsin, iron haematoxylin and Fullmer and Lillie's methods) immunohistochemical (antibody against collagen I, II and elastin) and ultrastructural analyses were performed. Three phases in the healing process were distinguished: 1) inflammatory, 2) proliferative, and 3) remodelling phase. The inflammatory phase was characterised by haematoma, fibrin deposition, inflammatory cells, fibroblasts, beginning of collagen fibrillogenesis (200-400 A ø fibrils) and oxytalan fibrils. The proliferative phase was characterised by angiogenesis and fibroblast proliferation. Collagen fibres displayed a random arrangement and had a diameter of 400-600 A. Immature elastic fibres reached maximum tissutal concentration. In the remodelling phase, hypocellularity, normal vascularisation, tendon crimps, collagen fibres (800-1,000 A ø), elastic fibres with increased elastin deposition and reduction in oxytalan fibres were observed. In the course of the healing process collagen and elastic fibre fibrillogenesis exhibited consistent quantitative and qualitative variations (i.e. differences in the type and diameter of fibrils). The present study suggests that, together with other matrix macromolecules, also elastic fibres (oxytalan, elaunin and mature) are synthesised in significantly higher amounts during reparative fibrillogenesis and play a role in cell-matrix interaction.

Achilles Tendon↗