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Biomedical subjects

E De Santis

Publications and source records attributed to E De Santis.

At least 19 recordsLinked to original sources

Calpain inhibitor in rabbit skeletal muscle: an immunochemical and histochemical study.

Calpastatin, the endogenous inhibitor of calcium-activated neutral proteases (calpains; EC 3.4.22.17), was studied in the rabbit vastus lateralis muscle by means of immunochemical and immunohistochemical techniques. Immunoaffinity chromatography using an antibody raised against the 34-kDa monomer of the 68-kDa dimeric inhibitor allowed us to isolate three main proteins (130-, 100- and 80-kDa). These proteins strongly inhibited calpain activity in muscle homogenate (I50 at about 50 micrograms/ml). Immunohistochemical experiments showed that calpastatin-related immunoreactivity was present in all fibre types (oxidative, glycolytic, oxidative-glycolytic) at both surface and cytoplasmic level. However, a few (20%) of the slow-twitch, oxidative fibres (5% of the total fibres), did not contain the cytoplasmic inhibitor. Specific immunoreactivity for calpastatin was also associated with the interstitial connective tissue. These results suggest that (i) calpastatin in skeletal muscle, as in other tissues, is present as a mixture of proteins of various molecular weights and (ii) the inhibitor may act not only in the cytoplasm but also at the surface or extracellular level.

Animals

[Chordoma (a review of 11 cases)].

Eleven cases of chordoma, localized at sacrum (3 cases), lumbar spine (6 cases), cervical spine (2 cases), are reported. Authors describe clinical and pathological findings of the tumor and underline peculiarity of spinal localization and difficulty of diagnosis, often delayed, particularly in sacral spine localizations. Radiotherapy and chemotherapy give poor results while surgery can be employed in the treatment on account of the slow evolution and of the not very frequent aptitude of the tumor to give metastases. However peculiar localization into the sacral spine allows to remove the whole tumor if only it is localized below the 2nd sacral vertebra; authors present such a case treated by means of subtotal resection of sacrum and coccyx. In proximal sacral localizations and in other spinal localizations, surgery is a palliative procedure and can only slow down the evolution of the tumor; recurrence is a rule, even in association with radiotherapy. However surgical treatment must be often performed because of myeloradicular involvement.

Cervical Vertebrae

[Percutaneous nucleotomy: the indications and limits].

The authors report the results of automated percutaneous diskectomy in the treatment of the herniated disk. During an 18-month period this procedure was used on 39 patients with both evident radicular pathology that had not regressed even after 4-6 weeks of medical and physical therapy as well as clear disk herniation revealed by diagnostic imaging. The level of the herniated disk was L4-L5 in 30 cases. L5-S1 in 7 cases, and L3-L4 in 2 cases. The clinical diagnosis was confirmed by CAT scan in 20 cases, by both CAT scan and x-ray of the spinal region in 14 cases, and by x-ray only in 5 cases. The patients were reviewed 2, 6, and 12 months after surgery. The results were classified according to Watters' criteria based on both the relief of pain and the resumption of everyday work activity. The satisfactory results (excellent and good) totaled 59% at the 6-month follow-up, with no substantial variation at the 1-year follow-up. Hemilaminectomy was performed in 12 cases with unsatisfactory results, confirming the diagnosis of disk herniation in 10 cases (extruded in 9 cases and protruded in 1 case). Diskectomy is a non-invasive, atraumatic method which is indicated for both protruded (non-sequestrated) and subumbilical hernias and allows rapid functional recovery. The rate of success can be increased with more accurate selection of patients based on imaging diagnosis (CAT scan and MRI).

Adolescent

[Review of 115 cases of osteoid osteoma].

115 cases of osteoid osteoma treated over more than 18 years is reported. In 1 case the nidus was manifested in 2 different sites after 14 years. The following is emphasized: the terminology for osteoid osteoma should be changed in reference to osteoblastoma; osteoid osteoma and osteoblastoma constitute different aspects of the same neoplasia; the number of observations of osteoid osteoma increases as there is greater knowledge on the varieties of the tumor; treatment, which is exclusively surgical, may be limited to excision of the nidus, in order to guarantee the best healing possible. Resection should be limited to observations where the nidus is masked by osteosclerosis.

Adolescent

[Diagnostic problems in Ewing's sarcoma].

Ewing's sarcoma presents diagnostic problems with several inflammatory processes (osteomyelitis, osteoperiostitis, eosinophilic granuloma) and other bone tumors. Clinical, radiographic and laboratory findings must be supported by a careful biopsy. Delimitation of reticulosarcoma and metastatic neuroblastoma is also extremely difficult from a histopathological point of view.

Adolescent

[Reticulosarcoma: diagnostic problems].

Diagnostic problems connected with reticulum cell sarcoma are analyzed. Clinical, radiological, biochemical and hematological investigations combined with an accurate pathologic study are essential in order to arrive at a precise diagnosis. Ewing's sarcoma and other osteolytic sarcomas are discussed in the differential diagnosis.

Adolescent

Current trends in the treatment of Ewing's sarcoma.

The authors analyse the results obtained in the treatment of Ewing's sarcoma by comparing the period previous to the use of chemotherapy with the more recent one involving the use of antiblastic drugs. Thirty-one patients with Ewing's sarcoma were divided into three groups according to the type of treatment used. The first group included 11 patients treated either by surgery or high dosage radiation (7000-8000 rads); the second group included 9 patients treated by radiation plus polychemotherapy; finally, the third group included 11 patients treated by surgery (excision in 5 localizations and segmental resection in the remaining 6), associated with polychemotherapy and low dosage radiotherapy. The results in the first group were discouraging as none of the patients survived five years; there was a low survival rate (33%) for the second group, partly due to the fact that there were 4 localizations in the pelvis, a site with a notoriously unfavourable prognosis; the third group had the highest percentage (55%) of long-term disease-free patients. Thus, in agreement with what is reported in the literature, the most radical surgery possible, associated with polychemotherapy and low-dose radiotherapy, currently seems to be the best treatment.

Adolescent

Circumscribed spontaneous heterotopic ossification in the soft tissues simulating sarcoma.

Eight cases are described of circumscribed heterotopic ossification in the soft tissues characterised by spontaneous onset, no history of trauma, and rapid course which have frequently led to a mistaken preoperative diagnosis of highly malignant tumour. The terminology differentiates it from myositis ossificans, which is a different entity. The authors emphasize the need for accurate evaluation of all the clinical and radiographic data in order to avoid an erroneous diagnosis of extraosseous osteogenic sarcoma or parosteal osteogenic sarcoma. In this regard, both radiography and histological examination demonstrate the so-called zoning pattern, namely a radiolucent central zone corresponding to the more immature area and consisting of fibrous tissue with active histiofibroblastic proliferations and a radiopaque peripheral area, where ossification is more mature the closer it gets to the periphery. Histological specimens obtained exclusively from the central area may lead even the most expert pathologists to a diagnosis of fibrosarcoma or osteogenic sarcoma. Finally, the pathogenetic aspects of the anomaly are discussed, as well as those concerned with the differential diagnosis from other types of heterotopic ossification.

Adolescent

Primary reticulosarcoma of bone (non-Hodgkin's lymphoma). A study of 12 cases.

Reticulosarcoma, nowadays usually referred to as non-Hodgkin's malignant lymphoma, is a particularly rare primary bone tumour. This study includes 12 cases observed over more than 15 years. The favourable clinical course of the tumour, and the use of complementary therapy justify a more extensive use of surgical treatment. Five cases were submitted to surgery plus complementary chemotherapy; two resections of the tibia, one of the humerus, one scapulectomy and one disarticulation of the hip. The remaining 7 cases were treated by radiation therapy. The overall prognosis of the disease is not very favourable (25% survival rate) although its slow progress gives a favourable clinical impression. Treatment may, however, influence the prognosis; much better results are obtained by radical surgery with complementary chemotherapy. In one resection of the tibial diaphysis and one radical scapulectomy there was no local recurrence or metastases at 3 and 4 years follow-up, whereas cases treated previously by less radical surgery and inadequate chemotherapy, although showing no local recurrence, did result in systemic diffusion of the disease.

Adolescent

Experimentally induced synovial sarcoma.

Synovial sarcoma has been induced in the knee joints of rats by intra-articular injection of 9-10-dimethyl-1-2-benzanthracene. Tumours developed from three to six months after the last injection. The neoplasms obtained were classified as synovial sarcoma (50%), fibrosarcoma (25%), giant cell sarcoma (15%), malignant fibrous histiocytoma (10%). The synovial membrane in the treated knee joints presented a chronic synovitis associated with fibrosis and proliferation of the lining cells. The primitive tumour spread locally infiltrating muscle and the adjacent bones. Metastases occurred most frequently to the lungs (70%) and liver (20%); lymph nodes were involved in 10%.

9,10-Dimethyl-1,2-benzanthracene