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Biomedical subjects

M Giovanelli

Publications and source records attributed to M Giovanelli.

At least 37 records · Page 2Linked to original sources
PubMed2000

Determination of the proliferation and apoptotic index in adrenocorticotropin-secreting pituitary tumors : comparison between micro- and macroadenomas.

We investigated the growth fraction and cell loss fraction in a large group of patients with Cushing's disease subdivided according to tumor size. Fifty-one patients, 8 males and 43 females, aged 12 through 61 years (mean age 34.6 +/- 1.5 years), were studied. Thirty-six patients had a microadenoma and the remaining 15 a macroadenoma. Immunohistochemical analysis was performed on paraffin-embedded material using a monoclonal antibody (MIB-1) directed against a proliferation-associated nuclear antigen, Ki-67, to measure the growth fraction. Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method, using a monoclonal antibody recognizing areas of DNA fragmentation. Ki-67 labeling index and apoptosis were counted on separate slides in at least 1000 evaluable cells. Patients with a macroadenoma had a significantly higher value of Ki-67 index (9.3 +/- 2.7%) than patients with microadenoma (2.8 +/- 0.5%; P < 0.002), whereas the apoptotic index was not significantly different in the two groups (1.7 +/- 0.8% in macroadenomas versus 0.8 +/- 0.3% in microadenomas). Our study shows that ACTH-secreting macroadenomas are characterized by a higher cell growth fraction than microadenomas, whereas the cell loss fraction is not different. A high proliferation rate seems to play a major role in determining the progression from small to large pituitary tumors in Cushing's disease.

Adenoma↗
PubMed2000

Acromegaly associated with a granular cell tumor of the neurohypophysis: a clinical and histological study. Case report.

Acromegaly is usually caused by a growth hormone (GH)-secreting pituitary adenoma, and hypersecretion of GH-releasing hormone (GHRH) from a hypothalamic or neuroendocrine tumor accounts for other cases. The authors report on the unusual association of acromegaly with a granular cell tumor of the neurohypophysis. A 42-year-old woman with a 10-year history of acral enlargement, headache, and menstrual abnormalities was referred to our department for a suspected GH-secreting pituitary adenoma. The patient's basal GH levels were mildly elevated at 4.8 microg/L, were not suppressed in response to an oral glucose tolerance test, and increased paradoxically after administration of thyrotropin-releasing hormone. The patient's insulin-like growth factor-1 (IGF-1) level was elevated at 462 microg/L, whereas a magnetic resonance image of the sella turcica revealed an intra- and suprasellar lesion that was compatible with a diagnosis of pituitary adenoma. A transsphenoidal approach to remove the lesion, which was mainly suprasellar, was successful during a second operative attempt, resulting in the clinical and biochemical regression of the patient's acromegaly. Four months postoperatively, the patient's basal GH level was 0.9 microg/L and her IGF-1 level was 140 microg/L. Histological analysis of the operative specimen demonstrated a granular cell tumor of the neurohypophysis, which when stained proved negative for pituitary hormones and GHRH. This case represents the first reported association between a granular cell tumor of the neurohypophysis and acromegaly. Granular cell tumor of the neurohypophysis could be added to the restricted list of neoplastic causes of acromegaly secondary to hypersecretion of a GH-releasing substance.

Acromegaly↗
PubMed2000

Glial cyst of the pineal gland: case report and considerations about surgical management.

Symptomatic glial cyst of the pineal gland are rare lesions. Origin, natural history and factors leading to cyst enlargement are not completely clear; thus management remain uncertain in some cases. We report a case of symptomatic glial cyst and analyze the implication for surgery. Surgical management is indicated in patients presenting hydrocephalus, mass effect or symptoms related to mesencephalic dysfunction. The infratentorial supracerebellar approach represent the first choice for this condition allowing easy orientation with wide exposure of the tumor and good visibility of deep venous systems that may be preserved. Size of the tumor is a key element in evaluation of the treatment and the appropriate course for asymptomatic cyst less than 1 cm in size consist of conservative management. Periodic follow up is always indicated.

Adult↗
PubMed2000

Fatal carotid dissection after blunt head trauma.

Occurrence of internal carotid artery injuries associated with skull base fracture has been reported. A. report a case of fatal intracranial carotid dissection related to petrous fracture involving the carotid canal. Identification of carotid lesions may be difficult and generally related to appearance of unexpected neurological deficit. Skull base fractures may be considered an indirect sign for detection of vascular injury. Patterns of the fracture are of paramount importance; routine CT scan may fail to detect basilar fractures and high definition fine-cut CT scan should be executed to carefully identify and evaluate fractures. Temporal and sphenoid bone fractures are common in head trauma and involvement of the course of the carotid artery is frequent. The involvement of the intracranial carotid artery course represents a direct risk factor for lesions of the petrous, lacerum and cavernous segments of the carotid artery. Early diagnosis of post-traumatic vascular injury may lead to prognosis improvement because of effectiveness of heparin anticoagulant therapy. Then vascular screening is recommendable in cases with complex fractures of the skull base and particularly fracturing along the course of the carotid artery. Magnetic resonance angiography may be considered the first line diagnostic tools for vascular screening. Angiography may be reserved for patients with a proven lesion or rapid neurological deterioration taking into account the possibility of interventional treatment.

Accidents, Traffic↗
PubMed2000

Proliferation index of nonfunctioning pituitary adenomas: correlations with clinical characteristics and long-term follow-up results.

OBJECTIVE: The recurrence of nonfunctioning pituitary adenomas (NFPAs) after surgical removal is common. The aim of our study was to investigate and correlate the growth fraction of NFPAs with clinical characteristics and long-term follow-up results. METHODS: Tumor specimens were obtained from 101 consecutive patients with NFPAs (48 female patients and 53 male patients; mean age, 52.0 +/- 1.5 yr). Specimens were immediately fixed in 10% buffered formalin and then embedded in paraffin. The Ki-67 antigen was assessed by immunocytochemical analysis using the monoclonal antibody MIB-1. The Ki-67 antigen labeling index (LI) was determined by counting a total of at least 1,000 neoplastic nuclei. RESULTS: The mean Ki-67 LI for the 101 patients was 2.4 +/- 0.3% (range, 0-23.0%). Only age at surgery was inversely correlated with the Ki-67 LI; sex, maximal tumor diameter, and invasiveness into the cavernous sinuses did not significantly affect the Ki-67 LI. The mean follow-up period was 39.7 +/- 2.1 months. During follow-up monitoring, 23 patients experienced tumor recurrence, after a mean period of 28.6 +/- 4.8 months. Invasiveness of the tumor on preoperative magnetic resonance imaging scans was the strongest predictor of late tumor recurrence, followed by previous pituitary surgery, younger age, and lack of postoperative radiotherapy. The Ki-67 LI had no independent prognostic value. CONCLUSION: Our study suggests that the clinical characteristics of patients with NFPAs, except for age at surgery, are not correlated with the Ki-67 LI. Moreover, the Ki-67 LI does not seem to provide independent information to identify patients at high risk for tumor recurrence.

Adenoma↗
PubMed1999

Surgical management of thyrotropin-secreting pituitary adenomas.

The reported cases of hyperthyroidism due to a TSH-secreting pituitary adenoma have steadily increased in previous years; however, information about the results and long term outcome after pituitary surgery is scanty. Twenty-four patients with a TSH-secreting adenoma underwent pituitary surgery at our department in the last 15 years. Hypersecretion of other pituitary hormones was diagnosed in 7 patients. Three patients were euthyroid at the time of surgery because of previous ablative thyroid therapies. The success rate of surgery strictly depends on the criteria used. Normalization of elevated FT3 and FT4 levels occurred in 17 of the 21 patients with preoperative hyperthyroidism: however, only those with early postoperative undetectable TSH level (12 cases) had no recurrence of disease during follow-up and no residual tumor tissue on postoperative MRI, whereas recurrence of hyperthyroidism occurred in 3 of the 5 patients without postoperative TSH inhibition. All 3 euthyroid patients had a subtotal removal of the tumor, as judged by postoperative MRI. Surgical removal is the therapy of choice of TSH-secreting adenomas, whereas radiotherapy and medical treatment with somatostatin analogues are usually reserved to patients with incomplete tumor removal. A thorough postoperative evaluation is necessary to discriminate between complete and partial remission of disease.

Adenoma↗
PubMed1998

Usefulness of markers of cell proliferation in the management of pituitary adenomas.

1. Pituitary adenomas are benign and slow-growing tumours whose clinical manifestations depend mainly on the secretory activity of the adenomatous cells. Except for prolactinomas, surgical removal of the tumour is the therapy of choice. 2. Despite extensive research on their clinical and pathophysiological aspects, few studies have explored the oncological characteristics of these rare lesions. Among these, the growth fraction of pituitary adenomas has been determined by different methods, of which the most useful are those performed in archival material. 3. The results reported in the literature show that adrenocorticotropic hormone-secreting tumours seem to be characterized by a higher proliferation index than the other types of pituitary adenomas, despite their usually small tumour size. 4. In small series of patients radiotherapy and medical treatment with dopaminergic drugs and octreotide were associated with a lower proliferation index than untreated tumours. Tumour size was not correlated with the growth fraction of the pituitary tumours, whereas invasiveness was correlated in most studies. 5. From a clinical point of view, however, the more promising utilization of the proliferation index seems to be in predicting the potential of recurrence of the tumour, thus allowing a more rational approach to follow-up and further treatment of patients with pituitary adenomas.

Adenoma↗
PubMed1997

Metastatic prostatic adenocarcinoma presenting as a pituitary mass: shrinkage of the lesion and clinical improvement with medical treatment.

BACKGROUND: Metastatic involvement of the pituitary gland is a very unusual presentation of prostatic cancer. We report a favorable response to medical treatment in such a patient. METHODS AND RESULTS: A 77-year-old man presented with blindness, ophthalmoplegia in his left eye, and mild impairment of memory and mental status. Neuroradiological studies showed a huge intra- and suprasellar lesion that destroyed the sellar floor and extended into the sphenoid sinus. Transsphenoidal biopsy of the lesion demonstrated a prostatic adenocarcinoma. Postoperative studies revealed an enlarged prostate gland and multiple lytic bone lesions. The patient was treated with a combination of leuprolide acetate plus flutamide. Four months later, the patient exhibited a marked improvement in his neurologic status and regained vision in the right eye (visual acuity 6/20). Repeat magnetic resonance imaging of the sellar region confirmed a striking shrinkage of the prostatic metastasis. The clinical status remained stable for 22 months, after which time the disease progressed and the patient died 25 months after beginning treatment. CONCLUSIONS: A favorable response to combined androgen blockade suggests that medical therapy should be considered the therapy of first choice when surgical removal of the metastatic lesion in the pituitary is impossible or too risky.

Adenocarcinoma↗
PubMed1997

Indium-111 pentetreotide single-photon emission tomography in patients with TSH-secreting pituitary adenomas: correlation with the effect of a single administration of octreotide on serum TSH levels.

Few data are available on the visualization of somatostatin receptors in vivo in patients with thyrotropin (TSH)-secreting adenoma. We studied five patients with TSH-secreting adenomas using single-photon emission tomography (SPET) after administration of indium-111 pentetreotide. The intensity of 111In-pentetreotide uptake by the tumours was correlated with the degree of TSH suppression after a single administration of 100 microg octreotide s. c. Five patients (three women and two men) aged 27-46 years were investigated. Except for one patient with acromegaly, all had pure TSH-secreting tumours. One patient was previously untreated, while two had received octreotide, one antithyroid drugs, and one radioiodine. In all patients SPET demonstrated increased uptake of 111In-pentetreotide by the pituitary adenoma. The target to non-target ratio (T/nT) of 111In-pentetreotide uptake was higher than 10 in three patients. Administration of 100 microg octreotide s. c. caused a significant reduction in TSH levels from 4.8+/-1.4 mU/l to a nadir of 3.1+/-1.1 mU/l after 6 h (P<<0.001 by ANOVA). Suppression of TSH secretion ranged from 30% to 60% of the baseline value. The T/nT ratio showed a trend toward a direct relationship with the degree of TSH inhibition after acute octreotide administration (r=0.67; P=NS). Our study showed that 111In-pentetreotide scan visualized somatostatin receptors in all five of the patients with TSH-secreting pituitary adenomas, confirming the frequent presence of somatostatin receptors in these rare tumours, even though the correlation with the TSH inhibition after a single administration of octreotide did not reach significance.

Adenoma↗
PubMed1997

Differentiation of clinically non-functioning pituitary adenomas from meningiomas and craniopharyngiomas by positron emission tomography with [18F]fluoro-ethyl-spiperone.

The differential diagnosis among various types of non-functioning sellar and parasellar tumours is sometimes difficult using currently available methods of morphological imaging. The aim of this study was to define whether assessment of the uptake of [18F]fluoro-ethyl-spiperone (FESP) with positron emission tomography (PET) could be helpful for the differential diagnosis of pituitary adenomas and other parasellar lesions, and for establishing the appropriate therapeutic approach. The population examined comprised 16 patients with the diagnosis of primary tumour of the sellar/parasellar region who were waiting to undergo surgical treatment. The results demonstrated that PET with [18F]FESP is a very specific method for differentiating adenomas from craniopharyngiomas and meningiomas. The visual interpretation of images allows such differentiation at approximately 70 min after tracer injection. Semiquantitative analysis of the dynamic PET data confirmed the results of visual interpretation, demonstrating that the uptake of [18F]FESP was consistently (i.e. throughout the series) at least two- to threefold higher in non-functioning adenomas than in other parasellar tumours as early as 70 min after tracer injection, and that it increased still further thereafter. It is concluded that PET with [18F]FESP might be of clinical value in those cases in which the differential diagnosis among various histological types of sellar tumour is uncertain with conventional methods.

Adenoma↗
PubMed1997

Oestrogen receptors in meningiomas: a correlative PET and immunohistochemical study.

There have been a number of indications that sex hormones can affect the rate of growth of meningiomas during pregnancy. The presence of oestrogen or progesterone receptors in meningiomas and the influence of sex hormones upon cell cultures derived from human meningiomas have been extensively investigated. The results have been controversial, with most of the discussion centring upon the presence and possible role of oestrogen receptors. The aim of the present study was to assess oestrogen receptors in human meningiomas with 16alpha[l8F]fluoro-17beta-oestradiol ([18F]FES) and positron emission tomography (PET). With this purpose in mind, we measured the regional brain uptake of [18F]FES in six patients with a neuroradiological and histological diagnosis of meningioma, comparing the in vivo PET data with the immunohistological analysis of oestrogen receptors performed on formalin-fixed, paraffin-embedded tissue obtained at surgery. Two analyses were used for the in vivo measurement of [18F]FES binding to oestrogen receptors: the ratio of tumour activity to that of normal tissue (T/NT), calculated 90 min after tracer injection, and the ratio between the equilibrium distribution volume (DV) in normal and pathological tissues, calculated by means of a graphical kinetic analysis. PET studies demonstrated a marked uptake of [18F]FES by the tumour in four of the six patients. Immunohistochemical assay using a manual staining method capable of detecting oestrogen receptors at a level of > 10 pmol mg(-1) of protein detected only sparse immunostaining in one of the six meningiomas. Distinct albeit weak immunostaining was demonstrated in five of the six meningiomas when the sensitivity of the immunohistochemical assay was increased to < 10 pmol mg(-1) of protein by use of an automated staining method (Bioteck 1000). Comparison of the in vivo and immunohistochemical results showed a correlation in five of the six patients, thus indicating the high sensitivity of [18F]FES for the in vivo evaluation of oestrogen receptor expression.

Adult↗
PubMed1997

Nerve growth factor suppresses the tumoral phenotype of human prolactinomas.

We summarize here our data showing that various phenotypical characteristics distinguish prolactinoma cell lines obtained from responder and nonresponder patients, as defined by their responses to bromocriptine administration. Nonresponder cell lines have a higher degree of malignancy than responder cells and do not express D2 receptors for dopamine. Both cell lines express NGF receptors. Exposure of the most malignant nonresponder cell lines to NGF, both in vitro and when transplanted in vivo in nude mice, results in their differentiation into the responder phenotype reexpressing D2 receptors. Sequential administration of NGF and bromocriptine thus may be a promising therapy for patients refractory to bromocriptine.

Animals↗
PubMed1996

Surgical results in microadenomas.

Pituitary microadenomas are small tumors whose maximal diameter is less than 1 cm. The aim of surgical removal of microadenomas should be not only the reversal of hormone hypersecretion but also the preservation of normal anterior pituitary function. Our series includes 230 patients with a microadenoma who had their first operation in our department: 45 were GH-secreting, 92 were PRL-secreting, 90 were ACTH-secreting, and 3 were TSH-secreting. Remission of disease was achieved in 81%, 77%, 91%, and 100% of GH-, PRL-, ACTH-, and TSH-secreting adenomas, respectively. There was no perioperative mortality and only 5 patients experienced a major complication. A total of 7 patients had diabetes insipidus for at least 6 months after operation. Hypopituitarism, not present in any patients before operation, developed in 3.5% of the cases. Our experience confirms that patients with microadenomas have the best chances of a successful operation. Since tumor size should gradually increase with time, we underscore the need of early diagnosis and treatment in patients with pituitary adenomas.

Adenoma↗
PubMed1996

Cavernous haemangioma of the pineal region.

Cavernous haemangiomas rarely occur in the pineal region, only eight histologically verified cases have been reported to date. Clinically and radiographically, they are often confused with other tumours of the pineal region, particularly germ cell tumours. When radiotherapy is performed without the benefit of biopsy, cavernous haemangiomas as well as other radioresistant neoplasms may be unnecessarily treated. We report two surgically treated cases of cavernous haemangioma of the pineal region, and comment upon one treated by shunt placement alone. Two cases were associated with an adjacent venous malformation. In all instances, magnetic resonance imaging (MRI) permitted a correct pre-operative diagnosis. We conclude that surgical exploration and total resection is the treatment of choice when the diagnosis of cavernous haemangioma is suspected on the basis of neuro-imaging. A conservative attitude is justifiable in the case of elderly patients with a higher surgical risk.

Adult↗
PubMed1996

Surgical therapy of pituitary adenomas.

In a series of approximately 1,000 patients with pituitary adenoma who were operated on at our institution from 1970 to 1994, 932 were operated on for the first time. Most microadenomas were corticotropin (ACTH)-secreting, whereas all nonfunctioning adenomas were macroadenomas, reflecting internal surgical policy. Only 48 of 932 patients (5.1%) had transcranial surgery. Using stringent criteria for the definition of a cure, we obtained remission of disease in 54.9%, 87.3%, 66.7%, and 46.2% of all patients with growth hormone (GH)-, ACTH-, thyrotropin (TSH)-, and prolactin (PRL)-secreting adenomas, respectively. The good result in patients with Cushing's disease is related to the higher percentage of microadenomas (approximately equal to 80%) in this group. Unfavorable prognostic characteristics for all adenomas are increasing tumor size, invasiveness, infiltration, and high serum levels of the hypersecreted hormone. The absence of a reliable tumor marker makes it difficult to assess the results of surgery in patients with nonfunctioning pituitary adenoma, but normalization or improvement of visual defects occurred in 72.4% of patients. Permanent worsening of vision was detected in 2.2%, mostly operated on through the transcranial approach, but they had large tumors and so were at greater risk. Accordingly, there was a higher death rate in patients who received the transcranial operation (two of 48; 4.2%) than in patients operated on through the trans-sphenoidal route (seven of 884; 0.8%). However, between 1970 and 1980, the mortality rate was 1.6% (six of 367 patients), while between 1981 and 1994, it was 0.5% (three of 565 patients), stressing the importance of surgical experience and perioperative medical management in improving the safety of pituitary surgery.

Adenoma↗
PubMed1996

Criteria of cure and follow-up of central hyperthyroidism due to thyrotropin-secreting pituitary adenomas.

The recorded number of patients with central hyperthyroidism due to TSH-secreting pituitary adenoma doubled in the last few years after the introduction of ultrasensitive TSH assays in the assessment of thyroid function; however, information about the results and the criteria for cure after pituitary surgery is scanty. Seventeen patients with a TSH-secreting adenoma, diagnosed on the basis of detectable TSH levels in the face of high free thyroid hormone concentrations and pituitary lesion at neuroimaging, underwent pituitary surgery. Hypersecretion of other pituitary hormones was diagnosed in 5 of 17 patients. Four patients were initially misdiagnosed and treated with thyroid surgery or radioiodine therapy. The majority (86%) of hyperthyroid patients normalized thyroid hormone concentrations and regained euthyroidism, although pituitary imaging, alpha-subunit, and alpha-subunit/TSH molar ratio normalized in only 47%, 54%, and 58% of patients, respectively. Moreover, TSH secretion was normally suppressed by T3 in 40% of the patients. Interestingly, the finding of undetectable TSH levels 7 days after surgery was highly predictive of successful outcome. During long term follow-up, there was one relapse of hyperthyroidism. Early diagnosis of TSH-secreting adenomas permits a high rate of remission of hyperthyroidism after surgery. However, normalization of thyroid function alone does not necessarily reflect complete removal of the tumor, and more comprehensive criteria of cure based on pituitary imaging, hormone measurement, and suppression of TSH during T3 administration should be used. Lastly, all patients need an accurate long term follow-up to monitor the possible recurrence of the adenoma.

Adenoma↗
PubMed1996

Nerve growth factor controls proliferation and progression of human prolactinoma cell lines through an autocrine mechanism.

Two different human prolactinoma phenotypes (responders and nonresponders), which are distinguished by different tumorigenic potential and different responsiveness to dopaminergic therapy, have recently been identified. Responders show low proliferation rate, low tumorigenic potential, and expression of D-2 receptors for dopamine (DA), while nonresponders are characterized by high proliferation rate, high tumorigenic potential, and lack of expression of DA D-2 receptors. In this study it has been shown that both gp140trk and gp75 components of nerve growth factor (NGF) receptor are expressed in responder prolactinoma cell lines. High levels of both NGF gene transcript and protein were also found in responders, and biologically active NGF was detectable in the media conditioned by these cells. Ablation of NGF production in responder cells by hybridization arrest of translation through NGF antisense oligonucleotides resulted in: 1) loss of secreted NGF; 2) loss of expression of gp75; 3) loss of expression of DA D-2 receptors; and 4) a remarkable increase in the cell proliferation rate. These results thus suggest that a NGF-mediated autocrine loop essential to control cell proliferation and to preserve some phenotypical characteristics of mammotroph cells is present in responder prolactinoma cell lines. Analysis of nonresponders showed that these cells express gp140trk but no detectable levels of gp75. In addition, no NGF mRNA or protein was detectable in nonresponders. Exposure of these cells to NGF resulted in the permanent expression of NGF mRNA and in the production and secretion of NGF protein, thus establishing the same NGF-mediated autocrine loop present in responders. As a result, it has been shown that nonresponder cells treated with NGF acquire and maintain most of the phenotypic characteristics of normal mammotroph cells. In conclusion, the present work reports that a NGF-mediated autocrine loop with an inhibitory role in the control of cell proliferation and tumor progression is active in the more differentiated DA-sensitive prolactinoma cell lines and is lost in the most malignant prolactinoma cells refractory to the dopaminergic therapy. Alterations in the expression of this autocrine loop thus may lead to cell transformation and tumor progression.

Animals↗