[Ultrastructural aspects of the embryonal and extra-embryonal entoderm of the chicken blastoderm].
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Biomedical subjects
Publications and source records attributed to A Ruggeri.
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Spontaneous cerebellar haemorrhage is very rare in children and is often associated with blood diseases such as haemophilia A or acute lymphatic leukaemia. During 1995, two paediatric patients with spontaneous cerebellar haemorrhage underwent surgical treatment in the Neurotraumatology Division of "La Sapienza" University hospital in Rome. The authors discuss this unusual pathology with particular regard to the age of the patients described.
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AIMS AND BACKGROUND: Pituitary adenomas are usually considered well differentiated tumors, even if in about one third of cases they invade surrounding tissues, with the possibility of postoperative relapse after complete surgical removal. Adrenocorticotropic hormone (ACTH) secreting adenomas seem to be the most infiltrating subtype, with a higher incidence of recurrence. Ki-67 is a nuclear antigen which is easily detectable by means of the MIB-1 monoclonal antibody, and the labeling index (LI) obtained can be considered a marker of tumor proliferation. METHODS: In order to identify the growth fraction of these tumors we used the MIB-1 antibody to evaluate the expression of Ki-67 antibody in 11 ACTH secreting pituitary adenomas and to compare it with the LI obtained in 98 other hormone secreting or non-functioning pituitary adenomas consecutively operated on during a 40-month period. RESULTS: In relation to surgically verified infiltration of the sellar floor dura and bone, we identified eight non-invasive and three invasive ACTH secreting pituitary adenomas. All invasive tumors infiltrated the wall of the cavernous sinus (CS). The mean Ki-67 LI was 5.88 +/- 9.13% versus 2.33 +/- 2.40% in non-ACTH secreting adenomas (P = 0.0025). It was 13.27 +/- 15.42% in invasive and 3.11 +/- 4.37% in non-invasive ACTH adenomas, and 18.40 +/- 17.82% in patients over 50 years versus 3.10 +/- 4.09% in younger subjects (P = 0.02). CONCLUSIONS: Ki-67 LI is a useful marker in the determination of proliferative activity and invasiveness of anterior pituitary adenomas. Our data seem to confirm that ACTH secreting adenomas have a higher growth fraction than other pituitary adenomas and this observation presumably explains the higher incidence of relapse of these tumors even after macroscopically total removal.
Glioblastoma multiforme is the most malignant tumor of the glial series. The average survival of patients with this tumor ranges from 6 to 12 months. The case of a patient who survived for more than 11 years after diagnosis of a temporal-occipital glioblastoma which was treated with surgery, radiotherapy and chemotherapy is described. The authors deduce that among patients with glioblastoma multiforme (GM), those with a long disease-free interval after initial diagnosis who undergo multimodal therapy, including aggressive tumor removal, are the most likely long-term survivors (LS). Other factors which appeared to be related to longer survival were younger age and high Karnofsky scores.
AIMS AND BACKGROUND: Histiocytosis X is a condition characterized by an abnormal proliferation of histiocytes with a variable granulomatous and inflammatory component; bone involvement is almost always present. The aim of this study was to define the management of solitary eosinophilic granuloma (EG) of the calvaria in adult patients, in relation to the size and site of the lesion. METHODS: Fourteen patients, ranging in age from 7 to 45 years, with solitary eosinophilic granuloma of the calvaria were surgically treated by craniectomy or curettage and cranioplasty. We subgrouped the lesions into two types: A) lesions localized inside the diploë and/or compressing the cerebral parenchyma below but without dural infiltration; B) lesions with mainly intracranial growth, compressing the cerebral parenchyma and infiltrating the dura. The infiltrated dura mater in type B lesions was replaced with a dural patch. Cranioplasty was performed in lesions with a diameter of 4 cm or more and/or located in aesthetically exposed areas of the skull. RESULTS: None of the patients died during the study and no local or systemic recurrences were observed during follow-up (min. 3 yrs, max. 8 yrs). CONCLUSIONS: Surgical treatment of patients with isolated EG of the calvaria not only is simple and quick but also allows histological diagnosis of the osteolytic lesion. These patients do not require further adjuvant treatment. Cranioplasty should be performed when the lesion has a diameter of 4 cm or more, when it is located in aesthetically exposed areas of the skull such as the frontal or temporal bones, or when it produces alterations of the normal skull morphology.
We had carried out a detailed morphological study on the human acellular extrinsic fiber cementum (AEFC) in order to support the exclusively extrinsic origin of matrix collagen bundles. Mesial and distal cervical third of fresh premolars from young individuals were examined. Semi-thin and thin section clearly show the Sharpey fibres entering in the cementum at right-angle to the root surface and coursing throughout the cementum to the cemento-dentinal junction. On their way to the dentin the Sharpey fibres divide into smaller bundles which, coursing obliquely or tangentially, intersect with others deriving from neighbouring Sharpey fibres. Both de-proteinated and decalcified samples observed at SEM present Sharpey fibres along the fractured surfaces entering and running trough the cementum perpendicularly to the root surface. Fibril bundles are seen branching out from the main body of a single Sharpey fibre and coursing obliquely or perpendicularly to the original fibre. These morphological evidences obtained both at TEM and SEM further confirm that in AEFC fibril bundles running parallel or obliquely to the root surface are branches of Sharpey fibres and not intrinsic cementum fibres.
A histological and ultrastructural study was carried out on the spongy bone response to smooth titanium oral implant surfaces. The samples obtained both from monkeys and from patients at various times from the implant insertion revealed that the bone-implant integration developed through different morphological aspects. The implant surface appeared in contact with medullary lacunae, as well as with osteoid tissue or directly with bone matrix. The complementary ultrastructural techniques employed have shown that the medullary lacunae appeared as wide and flattened cisternae delimited by a continuous single layer of flattened cells forming a thin lamina adhering to the implant and an endosteal lamina facing the bone surface. For their position and flattened shape we named them peri-implant medullary cisternae. The presence of blood vessels, reticular cells and myeloid cells in their lumen suggested that these peri-implant medullary cisternae were functional sites of new bone formation.
Using transmission electron microscopy, patellar tendons that had been autografted to replace the ACL were studied. Follow-up biopsies, performed at 6, 12 and 24 months after reconstructive surgery demonstrated that the autograft patellar tendons had undergone considerable change. After 6 months, the large collagen fibrils were less numerous and more widely spaced. The spaces were occupied by dense colonies of very small, newly-formed collagen fibrils and were rich in glycosaminoglycans. Small elastic fibres, fibrocytes, round cells with abundant rough endoplasmic reticulum and macrophage-like cells were scattered among the collagen fibrils. At 12 months, sporadic clumps of large collagen fibrils were seen between the compact bundles of small, uniform collagen fibrils. Both elastic and oxytalan fibres were observed; round cells with abundant rough endoplasmic reticulum were the most prevalent cell type. At 24 months, the tissue had the appearance of a normal ligament. The small uniform collagen fibrils had formed large, compact bundles that were prevalently arrayed parallel to the long axis. Both elastic and oxytalan fibres were observed and the numerous cells present exhibited the same morphological features as those observed at 12 months after surgery. The appearance of compact collagen bundles, the abundant elastic system and the abundance of active cells observed in the patellar tendon autograft 24 months after implantation, suggest that this type of tissue is a valid functional ACL substitute of a knee required to perform normal mechanical activity.
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The parapharyngeal space is a fat-filled region situated deep in the head between the basicranium and the oral floor. It can be divided in two parts: the prestyloid and the poststyloid space. The mandibular nerve is contained in the prestyloid space, while the carotid artery, jugular vein, IX, X, XI, XII cranial nerves, cervical sympathetic chain and junctional lymph nodes are situated in the poststyloid compartment. The normal CT anatomy and CT findings in 22 patients with proven lesions of the parapharyngeal space are described. Three different groups of neoplastic processes can be distinguished: primary tumours, secondary tumours and enlarged lymph nodes. The nature of the lesions developing in the parapharyngeal space can be diagnosed by CT in many cases.
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