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S Pezzotta

Publications and source records attributed to S Pezzotta.

At least 19 recordsLinked to original sources
PubMed2004

Endoscopic approach for the treatment of relapses in cystic craniopharyngiomas.

INTRODUCTION: Craniopharyngiomas are tumours of the central nervous system of dysontogenetic origin. They are most commonly localized in the sellar region and appear to originate from an embryogenetic defect of the Rathke cleft. It is universally accepted that radical surgery should be performed as first surgery because surgery after relapses usually causes more difficulty due to tighter adhesion to surrounding structures. It is essential when relapses occur to evaluate which technique to use for treatment. For this reason, any new approach is welcomed in order to have as many alternatives as possible. MATERIAL AND METHODS: In this paper we present the treatment, with a minimum follow-up of 4 years, of 5 paediatric patients affected by cystic craniopharyngiomas who went through first traditional surgery in other institutions and suffered relapses in various anatomical structures. One had a second successful endoscopic attempt at total gross resection. In 3 cases we endoscopically implanted a stent in the cystic cavity draining the cystic liquid out from the cystic cavity of the craniopharyngioma to the sphenoid sinus in order to form an accessory sinus. In 1 case a multiphase treatment has been undertaken. RESULTS: All patients treated using a transsphenoidal endoscopic approach are still living, without relapses and no postoperative complications. In particular, there where no episodes of vasospasm (a common complication reported in the literature when the "motor oil" comes into contact with the subarachnoid space) or infections. The patient treated using the multiphase approach recovered but suffered a recurrence 2 years later due to hypothalamic infiltration. DISCUSSION AND CONCLUSIONS: Craniopharyngioma relapse needs different treatments. Many alternative approaches have been reported but none of them is the first choice alternative. We believe endoscopic stent placement in the cystic cavity is an alternative method for the treatment of cystic relapses.

Adolescent↗
PubMed2002

True 3D reconstruction for planning of surgery on malformed skulls.

OBJECTIVES: Since the difficulty associated with surgical planning of craniosynostosis is mostly due to the inadequate possibilities for simulation of surgery, a new technique for constructing a precise reproduction of a patient's malformed skull has been developed. MATERIALS AND METHODS: CT scans of ten malformed skulls on a scale of 1:1 and with 1-mm slices have been used to reconstruct the skulls in a special resin using a special lathe used in the automobile construction industry for formula one engines. This lathe works in the opposite way to other lathes: by apposition of material instead of subtraction. RESULTS: The anatomical detail of the phantom is of a very high degree. The surgical planning it allows has proved highly consistent with reality in all cases in which it has been used in the planning before the operation. DISCUSSION AND CONCLUSIONS: This technique has made it possible to plan the surgical treatment of all patients with craniosynostosis in a highly satisfactory way. It has reduced operating times, in addition to which it provides information on materials needed, avoiding waste, and is also an excellent teaching method for residents.

Craniosynostoses↗
PubMed1998

Basal ganglia precursors found in aggregates following embryonic transplantation adopt a striatal phenotype in heterotopic locations.

Transplantation of immature CNS-derived cells into the developing brain is a powerful approach to investigate the factors that regulate neuronal position and phenotype. CNS progenitor cells dissociated from the embryonic striatum and implanted into the brain of embryos of the same species generate cells that reaggregate to form easily recognizable structures that we previously called clusters and cells that disperse and integrate as single cells into the host brain. We sought to determine if the neurons in the clusters differentiate according to their final location or acquire a striatal phenotype in heterotopic positions. We transplanted dissociated cells from the E14 rat medial and lateral ganglionic eminences, either combined or in isolation, into the E16 embryonic rat brain. At all time points, we found clusters of BrdU- and DiI-labelled donor cells located in the forebrain and hindbrain, without any apparent preference for striatum. Immunocytochemical analyses revealed that cells in the clusters expressed DARPP-32 and ARPP-21, two antigens typically co-expressed in striatal medium-sized spiny neurons. In agreement with observations previously noted by several groups, isolated cells integrated into heterologous host areas do not express basal ganglia phenotypes. These data imply that immature striatal neuronal progenitors exert a community effect on each other that is permissive and/or instructive for development of a striatal phenotype in heterotopic locations.

Animals↗
PubMed1998

Evolution of childhood central diabetes insipidus into panhypopituitarism with a large hypothalamic mass: is 'lymphocytic infundibuloneurohypophysitis' in children a different entity?

We report on a 15-year-old girl who had presented with acute onset central diabetes insipidus at the age of 8 years; this was followed by growth failure due to acquired growth hormone deficiency. Initial magnetic resonance imaging showed a uniformly enlarged pituitary stalk and absence of posterior pituitary hyperintensity. Frequent patient examination and magnetic resonance imaging gave unchanged results until after 5 years a large hypothalamic mass and panhypopituitarism were found. Dynamic magnetic resonance imaging documented hypothalamic-pituitary vasculopathy. Histopathological examination revealed perivascular inflammatory lymphoplasmic infiltrates with no granulomatosis or necrosis and negative staining for S-100 protein, suggesting autoimmune inflammatory disease (lymphocytic infundibuloneurohypophysitis?). The response to glucocorticoid pulses (30 mg/kg per day for 3 days i.v.) was favorable. the hypothalamic mass being halved and partial anterior pituitary function recovery maintained for 2 years after the start of treatment. We suggest that long-term surveillance is needed for isolated and chronic thickening of the pituitary stalk and that dynamic magnetic resonance imaging can contribute to the demonstration of hypothalamic-pituitary vascular impairment associated with local vasculitis.

Age of Onset↗
PubMed1996

CNS-85 trial: a cooperative pediatric CNS tumor study--results of treatment of medulloblastoma patients.

Between 1985 and 1989, 38 children with newly diagnosed medulloblastoma entered our therapeutic protocol. After surgery and postoperative staging assessments, patients were assigned to risk groups. Eleven with "standard-risk" (SR) tumors were treated with radiation therapy alone, while 27 with "high-risk" (HR) tumors received radiation therapy plus adjuvant chemotherapy with vincristine, methotrexate, VM-26, and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU). After a minimum follow-up of 5 years (range 5-9 years) 21/38 children had developed a recurrence or progression of their disease and 19/38 patients had died. Five-year event-free survival rates and 5-year total survival rates for all 38 patients were 47.4% and 50% respectively. The event-free survival rates at 5 years for SR and HR patients separately were 27.3% and 55.6%, respectively. The corresponding 5-year total survival rates were 27.3% and 59.3%. The differences were not statistically significant. Univariate analysis showed age at diagnosis to be the most important prognostic factor. Infants aged 5 years or less had a significantly shorter event-free survival time than older patients (P = 0.00897). Similar effects were found when total survival time was considered. There were significant differences in outcome in patients receiving different doses of radiation, suggesting a dose-response relationship. A Cox stepwise multivariate analysis showed age at diagnosis as the only independent prognostic factor. Variables relating to treatment entered the model, suggesting that chemotherapy could play an important role in determining outcome.

Adolescent↗
PubMed1995

In vivo enhanced antitumor activity of carmustine [N,N'-bis(2-chloroethyl)-N-nitrosourea] by simvastatin.

The effects of a combination of simvastatin, a cholesterol-lowering agent, and carmustine (BCNU; N,N'-bis(2-chloroethyl)-N-nitrosourea) on experimental C6 glioma were studied in vitro and in vivo. In vitro simvastatin and BCNU alone inhibited cell proliferation in a dose-dependent fashion. A subliminal concentration of simvastatin (0.1 microM) markedly and synergistically increased the BCNU toxicity to C6 glioma cells. The cytofluorimetric analysis of DNA from simvastatin-treated C6 glioma cells showed, besides the already described arrest in G1, an arrest/retardation in G2-M. Mitotic index from C6 cells incubated with simvastatin (10 microM) decreased by about 90%, indicating a specific C6 arrest/retardation in G2. The drug effects could be completely reversed by simvastatin withdrawal or mevalonate addition to the cultured cells. The combination of simvastatin and BCNU resulted predominantly from the profound retardation of cells in the G2-M compartment of the cell cycle. In vivo simvastatin (administered daily mixed with food) and BCNU (single i.p. injection), when given separately, caused a dose-dependent inhibition of labeling index in C6 glioma homografts (ID50, 61 mg/kg/day and 8.7 mg/kg, respectively). The combination of the lowest doses tested (simvastatin, 25 mg/kg/day and BCNU 0.3 mg/kg) resulted in a significant growth delay (compared to either drug alone) in C6 glioma (P < 0.05). There was no significant increase in toxicity as assessed by myelosuppression (WBC counts and bone marrow labeling index) and body weight. The results provide in vivo support for the combined use of simvastatin, a cholesterol-lowering agent, and BCNU in brain tumor treatment.

Animals↗
PubMed1995

Effects of vitamin D and retinoic acid on human glioblastoma cell lines.

The biological significance of vitamin D receptors expressed by glioblastoma and other glial tumours is still unclear. In an effort to clarify this issue we studied the effects of increasing concentrations of 25-dihydroxyvitamin D3 and its metabolite 1 alpha,25-dihydroxyvitamin D3 on two human glioblastoma cell lines. Both substances were capable of inducing a significant (> 50%) reduction in growth of the two glioblastoma cell lines at dosages over 5 microM. When the HU 70 cell line was treated by increasing dilutions of 25-dihydroxyvitamin D3 combined with 1 microM all trans-retinoic acid, significant inhibition was apparent even after addition of 25-dihydroxyvitamin D3 in the nanomolar range. Reduction of growth index was mainly due to induced cell death. Our results provide in vitro evidence that vitamin D metabolites alone or in combination with retinoids may be potentially useful agents in the differentiation therapy of human malignant gliomas.

Brain Neoplasms↗
PubMed1994

A short term analysis of the behaviour of conditionally immortalized neuronal progenitors and primary neuroepithelial cells implanted into the fetal rat brain.

Conditionally immortalized (temperature-sensitive) striatal-derived neuronal progenitor cell lines and primary neuroepithelial cells were transplanted into the CNS of gestational day 15-16 rat fetuses using an 'in utero' surgical procedure. Each fetus received 2.5-3 x 10(4) donor cells previously labelled in vitro by incubation with 5-bromo-2'-deoxyuridine (BrdU). At 5 days following transplantation, 69% of the fetuses were still alive. Engrafted cells were detected by BrdU immunohistochemistry, and the appearance of the engrafted cells and the time course of Nestin and PCNA expression were measured at 6, 24, 64 h and 5 days after transplantation. The evolution of Large T-Antigen immunoreactivity in engrafted temperature-sensitive (ts) cells was also evaluated at the above time intervals. The results indicate that the majority of the implanted cells were aggregated into clusters 24 h after transplantation. These clusters were not visible at 6 h, when most of the cells were isolated. The clusters were located in both the ventricles and parenchyma. These findings were common to both ts cells and striatal primary neuroepithelial cells. At 64 h and 5 days, isolated cells associated with the germinal layer and scattered throughout the parenchyma were also found. In the clusters, Nestin expression decreased proportionally with time following transplantation. Furthermore, Large T-Antigen immunoreactivity disappeared from ts cells between 6 and 24 h after transplantation. Finally, measurements of the temporal evolution of PCNA expression within the clusters indicate a progressive reduction in the mitotic activity of the transplanted cells. The results demonstrate that striatal primary neuroepithelial cells and conditionally immortalized neuronal progenitors can survive, migrate and/or compartimentalize into clusters whilst changing their antigenic properties and ability to proliferate.

Animals↗
PubMed1994

Choroid plexus carcinoma: report of one case with favourable response to treatment.

Choroid plexus carcinoma (CPC) is a rare tumor with usually severe prognosis, whose optimal treatment has not yet been established. The exact role of complete surgical resection, chemotherapy, and radiotherapy has been debated but not clarified. We report one girl with CPC diagnosed at age 3 months and apparently cured with minimal surgical resection, chemotherapy, and delayed irradiation. At the age of 8 years, she is well, with minor psychomotor retardation and growth hormone deficiency as the only sequelae.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Altered membrane lipid composition in a human meningosarcoma.

In a sample of meningosarcoma, obtained at the time of surgery, the amount of total gangliosides and phospholipids was examined, together with the cholesterol content and the distribution of different ganglioside and phospholipid species. The phosphatidylinositol, phosphatidylinositol-4-phosphate, phosphatidylinositol-4, 5-bisphosphate and phosphatidylcholine fatty acid composition was also analyzed. The ganglioside pattern in the meningosarcoma was different from the previously reported pattern in meningiomas of different histological origin, showing a higher concentration of GD3, indicating that the so-called b pathway of ganglioside biosynthesis was the preferred one in this type of tumor; moreover the percentage content of polysialylated gangliosides was very low. Cholesterol and phospholipid content was lower than in meningiomas; the phosphatidylcholine increase and the sphingomyelin decrease would indicate a lower membrane microviscosity, a characteristic of tumor cells. Phosphoinositide and phosphatidylcholine fatty acid analysis revealed a considerable amount of docosahexaenoic acid. This abnormal presence of this fatty acid could lead to the production, after receptor stimulation, of a diacylglycerol containing docosahexaenoic acid, which, in turn, could be responsible for an altered activation pattern of protein kinase C, in this way promoting carcinogenesis.

Arachidonic Acid↗
PubMed1992

Medullomyoblastoma: report of two cases.

Two cases of medullomyoblastoma in children are described. The muscular component showed different features in the two cases and were associated with neuronal differentiation. Morphological, immunohistochemical, and electron microscopical findings are presented. The origin of the muscular component is discussed in relation to the findings in other cases of the literature. Both differentiation from primitive neuroepithelial cells and derivation from ectomesenchyme are considered.

Biomarkers, Tumor↗
PubMed1992

Correlation between magnetic resonance imaging of posterior pituitary and neurohypophyseal function in children with diabetes insipidus.

The posterior pituitary lobe and stalk were studied by magnetic resonance imaging in 20 children with diabetes insipidus of different origins: primary familial autosomal dominant (n = 2) or idiopathic (n = 2), and secondary to craniopharyngioma (n = 6, resected in 5), to Langerhans cell histiocytosis (n = 5), to excessive water intake (dipsogenic; n = 3), to renal vasopressin insensitivity (n = 1), and to osmoreceptor dysfunction (n = 1). Of the four children with primary diabetes insipidus, the posterior bright signal was recognizable in two with the familial autosomal dominant form and one with the idiopathic form; in the latter, the pituitary stalk was thin, while it was normal in the first two patients; no posterior hyperintense signal with enlarged and gadolinium-enhanced pituitary stalk was observed in the fourth. The posterior hyperintense signal was absent without evidence of ectopic posterior pituitary tissue regeneration in five children with surgically removed craniopharyngioma and was doubtful in the child with unresected craniopharyngioma; the stalk was unrecognizable in all patients. In the five children with Langherans cell histiocytosis, the posterior bright signal was absent, while the stalk was normal in two and unexpectedly enlarged in three (uniformly in two and mainly at the level of median eminence and hypothalamus in one). All five patients with dipsogenic or nephrogenic diabetes insipidus or osmoreceptor dysfunction had normal images of posterior pituitary lobe and stalk. Normal posterior pituitary bright signal and stalk were found in all 25 healthy control children. Plasma vasopressin was undetectable in all patients except in nephrogenic one, in the child with osmoreceptor dysfunction, and in two of three dipsogenic children, the third mimicking partial neurogenic diabetes insipidus.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

Brain tumours in infants. Preferred treatment options.

Since the advent of CT scan and MRI, the diagnosis of neonatal infantile brain tumours and related diseases is more easily accomplished; their rarity is reflected in the small number of cases reported. Astrocytomas and teratomas are the most common oncotypes in infants and particularly in neonates. Surgical mortality rates are not high and have decreased because of the advances of diagnosis and improvements in treatment. However, the survival rates are disappointing. Follow-up shows little improvement in last 2 decades. Adjuvant therapy is still a problem; radiotherapy gives a small percentage of favourable later neuropsychological results. Postoperative chemotherapy added to maximal surgical resection and delayed irradiation may prolong survival with only minimal short term neurotoxicity in very young children with malignant tumours. Different protocols of chemotherapy are suggested but still not definitely accepted. Radical surgery seems to have a higher chance of success in neonates than infants and remains the less aggressive means; in low grade gliomas after total removal it may be preferable to perform a second operation if the tumour recurs and withhold irradiation and chemotherapy until after 3 years of age.

Brain Neoplasms↗
PubMed1989

Growing fractures: an unusual complication of head injuries in pediatric patients.

Authors analyze three cases of growing fractures they observed in infants under the age of one year. It is noticeable that in two cases, even if the lesion was already present when babies underwent the first procedure, no specific treatment was adopted, thus resulting in a progressive enlargement of the extracranial mass. Surgical treatment must be performed quickly after the diagnosis of growing fracture is done due to the necessity of an early repair of the bone defect to avoid the eventual onset of neurological deficits since they are not reversible.

Arachnoid↗
PubMed1987

Shunt in high-risk newborns.

Twenty-four high-risk newborns with a low birth weight developed progressive hydrocephalus and underwent ventriculoperitoneal shunting (at the time of shunting they weighed 1,100-1,900 g, mean 1,541 g). The changes in hydrocephalus after shunting were determined by ultrasound examinations; preoperative examination was by CT. Of the factors evaluated for their relationship to shunt complication, we considered in particular babies with a CSF protein level of over 1.5 g/l (7 cases). These cases were treated with external drainage and later with ventriculoperitoneal shunting. Shunt infections occurred in 20.9%, in contrast with a low incidence of shunt blockage (8.3%), probably owing to previous external shunting in children with high CSF protein. There were 2 deaths (8.3%). All children underwent careful follow-up during the 1st year and serial checkups subsequently for 5 years.

Bacterial Infections↗