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F Meli

Publications and source records attributed to F Meli.

At least 19 recordsLinked to original sources
PubMed2004

An immunohistochemical study of extracellular matrix proteins laminin, fibronectin and type IV collagen in paediatric glioblastoma multiforme.

AIMS: In the recent decades many studies have been addressed in the literature to assess specific factors related to glioblastoma multiforme (GBM) invasion. However, few studies have evaluated tumour cell's interaction with specific extracellular matrix (ECM) components, and, moreover, there is a lack of information regarding the occurrence of these phenomena in paediatric GBM. METHODS AND RESULTS: ECM proteins were evaluated in six cases of paediatric GBM assessing the immunohistochemical expression of laminin, fibronectin, and type IV collagen. We used a semiquantitative scale, ranging from not detected (zero) to marked (3). Laminin expression was minimal in three cases, moderate in one case, marked and generalised in one patient and marked and focal in the last case. Fibronectin expression was minimal in three patients; moderate immunoreactivity was documented in one case. Conversely, one case was classified as marked with generalised distribution and the remaining case as marked with focal immunostaining. Type IV collagen expression was minimal in three cases, moderate in one, marked with focal reaction in one and marked with generalised reaction in the remaining case. CONCLUSIONS: This study provides additional insights into tumour invasion features of paediatric GBM, as ECM plays a pivotal role in numerous cellular functions during normal and pathological processes. Although based on a limited number of patients, this investigation may serve as a challenge for the management of paediatric GBM, stimulating trials with larger patient numbers aimed at documenting specific factors influencing GBM prognosis.

Biomarkers, Tumor↗
PubMed2003

Growing skull fracture of the posterior cranial fossa and of the orbital roof.

BACKGROUND: Growing Skull Fractures (GSF) are rare complications of head trauma, primarily reported in infancy and early childhood. GSF are commonly located on calvaria, and rarely in other locations, including the skull base. METHOD: In this study, we report two cases of GSF occurring in unusual locations. The first, a 8-month old girl, with a GSF of the suboccipital posterior fossa region, and the second, a 4-year old boy with a GSF of the right orbital roof. Both cases underwent operative treatment of the GSF, with microsurgical dissection and excision of the protruding gliotic brain tissue, watertight duraplasty and autologous bone cranial repair. The authors conducted a Medline search of the relevant English literature from 1966 to 2002. FINDINGS: From the search, three cases of suboccipital posterior fossa region GSF and twelve series of orbital GSF, describing a total of 22 cases, have been found. INTERPRETATION: A survey of the pathogenic mechanisms underlying this entity in these locations is reported. A review of suboccipital posterior fossa and orbital roof GSF cases, of nosological, ophthalmological and neurological data, neuroradiological and operative findings, and results of different treatment strategies are described.

Child, Preschool↗
PubMed2002

Cardiovascular and respiratory consequences of bilateral involvement of the medullary intermediate reticular formation in syringobulbia.

We studied five patients with clinical and radiological evidence of syringobulbia (SB) to determine whether the distribution of lesions in relationship to the cardiorespiratory control networks in the medullary intermediate reticular zone (IRt) correlates with the presence of abnormalities in autonomic cardiovascular and respiratory control in these patients. All patients underwent high resolution MRI to characterize the size, volume and distribution of the SB lesions, cardiovascular autonomic function testing and polysomnography. One patient with bilateral IRt involvement at both the rostral and caudal medulla had orthostatic hypotension (OH), absent HR(DB), abnormal Valsalva ratio, exaggerated fall of BP during phase II and absent phase IV during VM, and a dramatic fall of BP during head up tilt; this patient also had severe obstructive sleep apnea (OSA) and exhibited BP drops during each respiratory effort. A second patient, with bilateral IRt involvement restricted to the caudal medulla, had less severe cardiovascular autonomic dysfunction but also exhibited severe OSA. The other three patients had small SB cavities sparing the IRt and had sleep apnea but no autonomic dysfunction. Autonomic dysfunction could not be related to the size of the syrinx or the degree of atrophy in the cervical spinal cord in any of the five patients. Bilateral involvement of the IRt by SB produces cardiovascular autonomic failure and sleep apnea. In patients with more restricted lesions, autonomic and respiratory dysfunction may be dissociated. Clinico-radiological correlations using high resolution MRI assessment of medullary lesions can provide insight into the central organization of cardiovascular and respiratory control in humans.

Adult↗
PubMed2001

Merosin-positive congenital muscular dystrophy with mental retardation, microcephaly and central nervous system abnormalities unlinked to the Fukuyama muscular dystrophy and muscular-eye-brain loci: report of three siblings.

Classical merosin (2 laminin)-positive congenital muscular dystrophy is a heterogeneous subgroup of disorders; a few cases characterized by severe mental retardation, brain involvement and no ocular abnormalities were called Fukuyama-like congenital muscular dystrophy. We report a family of healthy non-consanguineous parents, with four affected siblings, of which one died at the age of 7 months due to an intercurrent illness, who presented congenital hypotonia, severe mental retardation, microcephaly, delayed psychomotor development, generalized muscular wasting and weakness with mild facial involvement, calf pseudohypertrophy, joint contractures and areflexia. Muscle biopsy disclosed severe muscular dystrophy. Immunostaining for laminin 2 80 kDa and clone Mer3/22B2 monoclonal antibodies, 1 and 1 chain was preserved. Magnetic resonance imaging findings were consistent with pontocerebellar hypoplasia, bilateral opercular abnormalities and focal cortical dysplasia as well as minute periventricular white matter changes. Clusters of small T2-weighted focal hyperintensities in both cerebellar hemispheres consistent with cysts were observed in two of the three siblings studied with magnetic resonance imaging. Ophthalmologic and cardiologic examination was normal. Haplotype analysis using microsatellite markers excluded the Fukuyama congenital muscular dystrophy, LAMA2 and muscle-eye-brain disease loci. Thus, a wider spectrum of phenotypes, gene defects and protein deficiencies might be involved in congenital muscular dystrophy with brain abnormalities.

Biopsy↗
PubMed2000

Acute ischemic stroke : polymorphonuclear leukocyte membrane fluidity and cytosolic Ca(2+) concentration at baseline and after chemotactic activation.

BACKGROUND AND PURPOSE: Several reports have considered the role of systemic leukocytes in acute ischemic stroke (AIS). Initially, greater attention was focused on the leukocyte count and subsequently on their adhesiveness, aggregation, rheology, and activation. The aim of this study was the evaluation of certain polymorphonuclear leukocyte (PMN) parameters, reflecting their rheology and activation, in subjects with AIS. METHODS: In a group of 19 subjects with AIS and in a control group of 18 subjects with asymptomatic vascular atherosclerotic disease, we evaluated the PMN membrane fluidity and cytosolic Ca(2+) concentration at baseline and after in vitro chemotactic activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). RESULTS: From the obtained data, it is evident that at baseline only PMN membrane fluidity distinguishes control subjects from AIS subjects. After PMN activation with PMA and fMLP, prolonged for 5 and 15 minutes, we found an increase in PMN cytosolic Ca(2+) concentration and a decrease in PMN membrane fluidity only in subjects with AIS. CONCLUSIONS: These findings emphasize that in subjects with AIS a functional alteration of systemic PMN cells is clearly expressed during chemotactic activation, although the mechanism of this abnormality is not yet explained.

Acute Disease↗
PubMed1998

Type II diabetics with macrovascular complications: polymorphonuclear leukocyte (PMN) filtration, PMN membrane fluidity and cytosolic Ca2+ content after activation.

We evaluated polymorphonuclear (PMN) filtration parameters, membrane fluidity and cytosolic Ca2+ content in 21 normal subjects and in 18 type II diabetics with macrovascular complications (MVC). Evaluations were carried out at baseline and after in vitro activation prolonged for 5 and 15 min. PMA (4-phorbol 12-myristate 13-acetate) and fMLP (N-formyl-methionyl-leucyl-phenylalanine) were used as stimulating agents. TMA-DPH (1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene) was used as fluorescent probe for the membrane fluidity tests and Fura 2-AM for the cytosolic Ca2+ content. A significant variation was evident in PMN filtration parameters at 5 and 15 min. No variation was present in PMN membrane fluidity and cytosolic Ca2+ content in normals. In type II diabetics with MVC, we found an increase solely in PMN cytosolic Ca2+ content after PMA activation and an early decrease in PMN membrane fluidity and a late increase in PMN cytosolic Ca2+ content after fMLP activation. After PMA activation alone (at 15 min), PMN filtration distinguishes normals from type II diabetics with MVC. The PMN filtration parameters behave similarly in the two groups, but PMN membrane fluidity and cytosolic Ca2+ content behave differently.

Aged↗
PubMed1997

[Hypertension and peripheral arterial hemodynamics].

Sixty uncomplicated hypertensive patients (40 stable and 20 borderline) were studied, by strain gauge plethysmography, in comparison with 25 normotensive subjects, in order to evaluate the arterial hemodynamics of the lower limbs in essential hypertension and to verify the different pattern in borderline and in stable hypertensives. Resting blood flow, even if lightly decreased in hypertensive groups, didn't show significant differences in its mean values; Peak Flow, instead, was reduced proportionally to the severity of hypertension in all the hypertensive patients, but only in the stable hypertensives did it prove statistically significant. Minimal Vascular Resistances showed a similar behaviour; they were significantly increased only in the stable hypertensives, whereas Basal Vascular Resistances, were raised in all hypertensive patients, in the borderline group too. Finally, half time and total hyperemic time, which indicate vascular reactivity, were significantly decreased in all hypertensives. These results suggest that the stable hypertensive patients principally develop arterial structural changes, while the borderline hypertensive patients have only functional modifications, such as a reduced compliance and a hyperdynamic condition.

Aged↗
PubMed1996

Leukocyte flow properties, polymorphonuclear membrane fluidity, and cytosolic Ca2+ content in subjects with vascular atherosclerotic disease with and without noninsulin-dependent diabetes mellitus.

The aim of this research was the evaluation of white blood cell (WBC) filtration, reflecting WBC flow properties, polymorphonuclear cell membrane fluidity, and cytosolic Ca2+ content in subjects with vascular atherosclerotic disease (VAD) and in VAD subjects with noninsulin-dependent diabetes mellitus (NIDDM), in good hemodynamic balance. The authors examined WBC filtration (unfractionated, mononuclear [MN], polymorphonuclear [PMN] cells), using the St. George Filtrometer and considering, respectively, the initial relative flow rate (IRFR) and the clogging rate (CR); the PMN membrane fluidity, employing the fluorescent probe TMA-DPH and calculating the fluorescence polarization degree; and the PMN cytosolic Ca2+ content, adopting the fluorescent probe Fura 2-AM and considering the ratio between the Fura 2-Ca2+ complex and the unchelated Fura 2 fluorescence intensity. The obtained data showed that only the filtration parameters (IRFR, CR) of unfractionated WBCs discriminated normal subjects from VAD groups, whereas the filtration parameters of MN and PMN cells did not demonstrate any distinction. PMN membrane fluidity did not distinguish normal subjects from VAD groups, whereas PMN cytosolic Ca2+ content was significantly increased in VAD groups in comparison with normal subjects. No relationship was evident between WBC filtration and plasma metabolic parameters; the correlations obtained between PMN filtration and other PMN parameters need further investigation.

Aged↗
PubMed1996

Somatosensory and visual evoked potentials study in young insulin-dependent diabetic patients.

To evaluate central nervous system involvement in diabetes, somatosensory (SEPs) and visual (VEPs) evoked potentials were investigated in a group of 35 patients and 20 sex, age-matched controls. In order to avoid methodological biases due to different type and duration of disease, we studied an omogeneous group of young insulin-dependent diabetics with ten or more year duration of disease. In our results VEP and SEP parameters were found abnormal in 10 (28%) patients, all of whom presenting clear signs of peripheral neuropathy. In diabetic patients median and tibial SEPs showed significant increase in absolute latency mean values of several components except interpeak intervals, as well as mean P 100 latencies were significantly increased in both eyes at 15' check size stimulation pattern. VEP and SEP components were not generally significantly associated with the indices of peripheral function. In contrast, in diabetics significant correlations were found between P 100 latencies and median SEP parameters including interpeak intervals. No major associations related VEP and SEP latencies to duration of diabetes and prevailing glycaemic control. In conclusion the central nervous system involvement in young insulin-dependent diabetics, even though diffusely present, seems unequivocally concomitant to peripheral conduction impairment.

Adolescent↗
PubMed1996

[Pulmonary hypertension caused by a severe scoliosis. Description of a case].

BACKGROUND: Pulmonary hypertension in childhood is uncommon. It can be idiopathic or secondary to other pathologies (cardiovascular, skeletric,...). CASE DESCRIPTION: We report on a 9 year old girl suffering from pulmonary hypertension due to severe dorso-lumbar scoliosis. CONCLUSIONS: We discuss the etiopathogenetic relationship between scoliosis and pulmonary hypertension, with particular reference to the role of the treatment with Milwaukee's corset in the evolution of the disease.

Female↗
PubMed1994

[Acute extra-axial hematoma post-traumatic of the clivus].

Magnetic Resonance Imaging (MRI) has amply shown its usefulness for the evaluation of traumatic cranio-encephalic lesions, particularly those involving the posterior fossa, due to the absence of bone artifacts, the availability of multiplanar sections and the greater sensitivity as regards Computerized Tomography (C. T.). We present an MRI examination of an extra-axial hematoma of the clivus in a child with head trauma, not visible on C. T. scans.

Brain Injuries↗
PubMed1991

Nerve conduction velocity and circulating immunocomplexes in type 1 diabetic children.

There is evidence from several laboratories of an increased prevalence of circulating immuno-complexes (CIC) in diabetic patients. It has also been suggested that CIC are pathogenetically related to chronic diabetic complications. The aim of this study was to assess peripheral nerve function in children with Type 1 diabetes and to evaluate the relationship between the neurophysiological abnormalities and the possible presence of CIC. The investigation was carried out in 25 Type 1 diabetic patients ranging in age from 7-19 years and in 20 normal controls. Neurophysiological assessment was performed to evaluate motor and sensory conduction velocity on median and tibial nerves. IgG-CIC were detected by the solid-phase C1q-binding and anti-C3 enzyme immuno-assay. The results of this study showed a greater slowing of median motor and sensory and tibial sensory conduction velocities in patients with CIC with respect to the patients without CIC, suggesting a possible role of immunological factors in the pathogenesis of diabetic neuropathy.

Adolescent↗
PubMed1989

Conduction velocity study in type 1 diabetic patients.

The role of metabolic abnormalities in the development of diabetic neuropathy is controversial. To investigate the peripheral nerve function and the influence of hyperglycemia on nerve conduction in insulin-dependent diabetes, a one-year neurophysiological study was carried out in 30 type 1 diabetic patients ranging in age from 2-16 years. During the 12-month follow-up period the glycosylated hemoglobin determination, motor conduction velocity of the peroneal nerve and the motor and sensory conduction of the tibial nerve were assessed 3 times, at the beginning of the study and every 6 months thereafter. The sensory latency was found significantly delayed in these patients as compared with the controls. The degree of sensory conduction slowing correlated well with the glycosylated hemoglobin concentrations and improved with the reduction in hyperglycemia.

Adolescent↗
PubMed1989

Cross-reactivity of anti-ssDNA antibodies with heparan sulfate in patients with type I diabetes mellitus.

Anti-single-stranded-DNA antibodies cross-reactive with heparan sulfate were detected in serums of patients with type I (insulin-dependent) diabetes mellitus. The results suggested that heparan sulfate, the major glycosaminoglycan constituent of the glomerular basement membrane, may serve as a target antigen in vivo for cross-reactive anti-DNA antibodies. These polyreactive antibodies, directed toward repeating negatively charged units, may neutralize the heparan sulfate-associated polyanionic sites in the glomerulus, leading to an abnormal permeability of anionic plasma proteins.

Child↗
PubMed1989

The relationship of insulin antibodies, platelet-fixing immune complexes and platelet-associated IgG to in vitro platelet aggregation and thromboxane B2 synthesis in childhood type 1 (insulin-dependent) diabetes mellitus.

The relationship of insulin antibodies, platelet-fixing soluble immune complexes and platelet associated IgG to in vitro platelet aggregation and thromboxane B2 synthesis was studied in a group of children with type 1 (insulin-dependent) diabetes mellitus. Insulin antibodies, through the formation of insulin anti-insulin platelet-fixing immune complexes, seem to increase the levels of platelet associated IgG and both insulin immunity and increased platelet associated IgG are associated with the highest degree of platelet aggregation and thromboxane synthesis. These data suggest a possible role of immune factors in the platelet disfunction of diabetic subjects. Both platelet abnormalities and immune factors have been thought to play a role in the pathogenesis of the late diabetic complications. In this paper data concerning a possible interaction between these two factors are presented.

Adenosine Diphosphate↗
PubMed1988

Chronic pachymeningitis associated to hypereosinophilia: case report.

A male 22 years old patient who consulted due to headache and increasing visual loss is being presented. Alterations in the exam were represented by right amaurosis and left temporal hemianopsis. Pathological and tomographical studies revealed chronic pachymeningitis with eosinophilic infiltration. An elevated eosinophilia and an increasing in anti-A and anti-B isoagglutinins were associated to the clinical course. They returned to normal values after treatment with tiabendazol. Even though there is not a certain conclusion as regards the etiology, the probable parasitary nature of the process is outlined.

Adult↗