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Biomedical subjects

G Zirattu

Publications and source records attributed to G Zirattu.

15 recordsLinked to original sources
PubMed1992

Morphological aspects of the synovial membrane and femoral epiphyseal cartilage in experimentally induced chronic anemia.

The authors describe the microscopic and ultrastructural changes in the synovial membrane and femoral growth cartilage in experimentally induced chronic anemia. The reiterated anoxic stimulus is responsible for premature morphologic changes which become progressively worse and then appear to stabilize after 30 days. The series of events at the completion of the experiment are characterized by the following: 1) villous hyperplasia-hypertrophy with an increase of the secretory vesicles of type B synoviocytes in the intima and lymphoplasmacellular infiltrates in the sub-intima of the synovial membrane with fragmentation of the bony trabeculae, 2) areas of premature closure of the growth cartilage, 3) irregularity of the profile, thickness, and structure of the articular cartilage. The authors propose a biologic correlation between the above osteoarticular changes and the typical features of certain disorders of this anatomical region (hemopathies, Legg-Calvé-Perthes disease).

Anemia↗
PubMed1991

Peripheral chondrosarcoma: ultrastructural investigation by transmission and scanning electron microscopy.

Ultrastructural analysis by transmission and scanning electron microscopy was performed on two grade 1 peripheral chondrosarcomas which had arisen from a preexisting osteochondroma. This analysis allowed us to determine the morphologic changes in both the cell and the matrix and suggested a low grade of malignancy. We emphasize that ultrastructural analysis with scanning and electron microscopy is only valid when conducted on representative areas of the tumor.

Adult↗
PubMed1991

[Morphologic scanning electron microscopic study of quantitative variations in the endosseous diaphyseal surface in normal and osteoporotic rats].

An ultrastructure study (S.E.M.) was performed on adult albino rats of the age, sex, and weight in order to assess the qualitative and quantitative variations in the endosteal diaphyseal surface of limbs relieved of mechanical stresses by means of prolonged cast immobilization. The final results confirmed the primary role played by osteoclasts and vascular bone channels, the latter of which open into the diaphysis, during resorption of compact diaphyseal bone, which occurs to the detriment of the bone surfaces in deposition and at rest.

Animals↗
PubMed1991

[The mineralization process in osteochondroma. A scanning electron microscopic study].

Thirty patients affected by osteochondroma were divided in two groups: 15 patients were in the age of development, and 15 patients had ended their development. The patients' age ranged from 4 to 42 years; 18 of them were males. The mineralization process (M.P.) of the osteochondral tissue was studied following hypochlorite treatment of the specimens. M.P. was particularly evident in patients during development and was characterized by round calcific nodules (calcospherites) which were linked to crossed collagen fibers. M.P. was morphologically similar to what is usually observed in normal and pathological specimens. Except in two cases, at the end of development the intertrabecular spaces were free of calcific material. In those two cases we observed a resumption of M.P. Mineralization was of calcospheritic type and started from islands of metaplastic cartilage. It was interpreted as a sign of possible transformation to peripheral chondrosarcoma. In a third case, osteoclastic activity caused deep, wide subperiosteal and trabecular erosion resulting in osteocartilaginous neoplastic tissue involution.

Adolescent↗
PubMed1990

Morphological aspects of the synovial membrane and the femoral epiphyseal nucleus in anemia induced experimentally (note 1).

The authors describe the macroscopic and ultra-structural changes in the synovial membrane and the growth nucleus consequent to anemia induced experimentally. In the anatomical region studied an early and a late response to the transitory anoxia is observed. The former is represented by the accentuation of the macrophagic activity of the A synoviocytes and by pictures of trabecular fragmentation. The latter is represented by hyperplasia of the synovial membrane, a reduction in the thickness of the joint cartilage, and by early and patchy calcification of the epiphyseal disc.

Anemia↗
PubMed1990

[Osteoid osteoma. A scanning electron microscopic study].

The mineralization process of the osteoid osteoma, after removal of the organic matrix from the specimens by treatment with 6% sodium hypochlorite, has been studied by SEM. The process was characterized by calcified nodules or calcospherites, variable in size from 0,1 to 2 microns, embedded among randomly oriented collagen bundles, which delimited trabeculae of sponge primary bone. Numerous osteocytic lacunae, in various degrees of development, in the mineralizing front were present. The ultrastructural feature of the mineralization in osteoid osteoma reflected a pattern of nodular and collagenous calcification, essentially similar to primary calcification, characteristic of rapidly developing woven bone.

Adolescent↗
PubMed1990

[Osteosis due to primary hyperparathyroidism. The SEM ultrastructural features of the periosteal and endosteal surfaces].

The study of four cases of osteosis caused by primary hyperparathyroidism, tree female and one male, which have undergone surgery for pathological fractures in met-epiphysis bone, allows to analyze with the help of scanning electron microscope modifications occurring in periosteal and endosteal bone matrix. The periosteal surface appears abundantly furrowed by large and deep canals, irregularly joined together. Areas of resorption, these at rest and these of osteodeposition are distributed in changeable but regular way. The bone turnover of endosteal side is particularly accentuated. This surface contains the bone trabeculae residuals and is widely marked by deep Howship's lacunae, which show intense osteoclastic activity. It seem that osteocytes cells participate actively in the process of osteolysis, widening the lacunae and small canals which appear to be surrounded by calcospherites arranged in irregular way. Osteogenetic activity, with large areas of deposition, is very intense, as a defence attempt against osteolytic resorption process.

Adult↗
PubMed1990

[The ultrastructural aspects of the synovial intima and subintima in arthrosis].

Synovial membrane removed surgically from patients during developing degenerative joint disease were studied under a scanning and transmission microscope. The results show that the synovial membrane is folding into villi of average dimensions (microvilli and macrovilli) which project into articular cavity. In regard to the villi, the morphology is locally changeable, with the atrophic-sclerotic areas alternated with hyperplastic areas, but topographically well defined. In the last ones, structural modifications of the intima layer, are characterized by hypertrophy of B synoviocytes, which are constituent and predominant cells in comparison with other cell-types. In the subintima around ectatic vessels, the linfomonocitary inflammatory infiltrations may be found. These alterations are the results of active biological process and because of this synovial membrane is of big importance in developing of osteoarthritis.

Aged↗
PubMed1989

Spinal cord dysfunction from lumbar disk herniation.

Two patients with a herniated disk respectively at the level of the L4-L5 and of the L5-S1 intervertebral spaces presented with pyramidal signs, bladder paralysis and radicular impairment. The symptoms subsided immediately following surgical removal of the prolapsed disk. The role of transient ischemia in the lower segments of the spinal cord as possible cause of this uncommon clinical picture is discussed, and the pertinent literature is reviewed.

Female↗
PubMed1988

A comparison between computerized tomography and myelography in radicular lumbar syndromes.

The clinical, tomographic and myelographic findings in 40 patients with radicular lumbar syndromes are analysed and discussed. The study shows that indications for surgical treatment must take into account errors in determining the level of the syndrome based on clinical examination (25%), false negatives (10%), and false positives (15%) resulting from CT scan and, finally, false negatives resulting from myelography (10%). It is emphasized that at present there is no real evidence to support preference for one or other of these instrumental tests. Only the clinical examination is capable of evaluating each case individually and thus providing the most reliable indications on which to base both diagnosis and treatment.

Adult↗
PubMed1985

Long-term results of surgical treatment for redundant roots of the cauda equina.

Seven patients with redundant roots of the cauda equina were followed 2 1/2-10 years after surgical decompression. Improvement of signs and symptoms occurred in all patients. However, none of them was neurologically intact at the time of the last physical examination, although persistence of minimal neurological signs and/or occasional pain did not prevent a useful occupational activity.

Adult↗
PubMed1985

Clinical and electrophysiological investigation of the results of operation for lumbar disc hernia. Preliminary results.

The long-term results of operations to remove disc hernias were assessed clinically and electrophysiologically in two groups of patients treated by different surgical techniques. The electrophysiological parameters determined were the motor conduction speed of the sciatic nerve, the H reflex, the minimum latency of the F wave and quantitative analysis of the EMG by the Willison method. The preliminary results reported in the present paper are related to two comparable samples of patients who underwent hemilaminoarthrectomy or hemilaminectomy for disc hernia at L5-S1. They show that the incidence of after effects was lower in the patients treated by simple hemilaminectomy.

Adult↗
PubMed1984

Redundant nerve roots of the cauda equina.

The authors have critically reviewed 8 cases which have come under their observation of a lumbosciatic syndrome due to redundant nerve roots of the cauda equina. Some of the clinical and myeloradiculographic features appear to be characteristic of this rare syndrome. Surgical intervention by decompressing the nerve roots of the cauda equina offers a very favourable prognosis.

Acute Disease↗
PubMedDate not supplied

Diagnostic value of extensor digitorum brevis F-wave in L5 root compression.

The sensibility of F-wave in detecting lumbosacral radicular compression has been found to range from 65% to 18%. The present study was performed on 24 patients suffering from unilateral L5 compressive radiculopathy. The aim was to verify the reliability of extensor digitorum brevis (EDB) F-wave in the diagnosis of L5 root impairment, by using different parameters such as minimal, mean, maximal latency and the difference of these parameters between the affected and unaffected sides. In all patients conventional needle EMG was also performed bilaterally. While the needle EMG showed abnormalities in L5 innervated muscles of all patients, at least one of the different EDB F-wave parameters was found to be abnormal in only 7 patients (29.2%). Moreover no significant relation was observed between the severity of EMG and F-wave abnormalities. We conclude that conventional needle EMG appears to be the most useful electrophysiological technique in the diagnosis of L5 compressive radiculopathy, while EDB F-wave does not provide additional information.

Adult↗