Andrea Marzola

Modeling and remodeling of human extraction sockets.

INTRODUCTION The available studies on extraction wound repair in humans are affected by significant limitations and have failed to evaluate tissue alterations occurring in all compartments of the hard tissue defect. AIM To monitor during a 6-month period the healing of human extraction sockets and include a semi-quantitative analysis of tissues and cell populations involved in various stages of the processes of modeling/remodeling. MATERIAL AND METHODS Twenty-seven biopsies, representative of the early (2-4 weeks, n=10), intermediate (6-8 weeks, n=6), and late phase (12-24 weeks, n=11) of healing, were collected and analysed. RESULTS Granulation tissue that was present in comparatively large amounts in the early healing phase of socket healing, was in the interval between the early and intermediate observation phase replaced with provisional matrix and woven bone. The density of vascular structures and macrophages slowly decreased from 2 to 4 weeks over time. The presence of osteoblasts peaked at 6-8 weeks and remained almost stable thereafter; a small number of osteoclasts were present in a few specimens at each observation interval. CONCLUSIONS The present findings demonstrated that great variability exists in man with respect to hard tissue formation within extraction sockets. Thus, whereas a provisional connective tissue consistently forms within the first weeks of healing, the interval during which mineralized bone is laid down is much less predictable.

Localized delivery of fibroblast growth factor–2 and brain-derived neurotrophic factor reduces spontaneous seizures in an epilepsy model

A loss of neurons is observed in the hippocampus of many patients with epilepsies of temporal lobe origin. It has been hypothesized that damage limitation or repair, for example using neurotrophic factors (NTFs), may prevent the transformation of a normal tissue into epileptic (epileptogenesis). Here, we used viral vectors to locally supplement two NTFs, fibroblast growth factor–2 (FGF-2) and brain-derived neurotrophic factor (BDNF), when epileptogenic damage was already in place. These vectors were first characterized in vitro, where they increased proliferation of neural progenitors and favored their differentiation into neurons, and they were then tested in a model of status epilepticus-induced neurodegeneration and epileptogenesis. When injected in a lesioned hippocampus, FGF-2/BDNF expressing vectors increased neuronogenesis, embanked neuronal damage, and reduced epileptogenesis. It is concluded that reduction of damage reduces epileptogenesis and that supplementing specific NTFs in lesion areas represents a new approach to the therapy of neuronal damage and of its consequences.

Presence of detectable levels of soluble HLA-G molecules in CSF of relapsing–remitting multiple sclerosis: relationship with CSF soluble HLA-I and IL-10 concentrations and MRI findings

We have investigated the presence of non-classical soluble HLA-G molecules (sHLA-G) in cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients and the possible relationships between CSF levels of sHLA-G, classical soluble HLA-I (sHLA-I) molecules, IL-10 amounts and Magnetic Resonance Imaging (MRI) findings were evaluated. We studied by ELISA technique the sHLA-I, sHLA-G and IL-10 levels in CSF of 50 relapsing-remitting (RR) MS patients stratified according to clinical and MRI evidence of disease activity. Thirty-six patients with other inflammatory neurological disorders (OIND) and 41 with non-inflammatory neurological disorders (NIND) were used as controls. CSF mean levels were significantly higher in MS and OIND than in NIND for sHLA-I (p<0.001) and in MS than in controls for sHLA-G (p<0.001), with no differences among the various groups for IL-10 mean concentrations. An increase in CSF sHLA-I was found in MS patients with Gd-enhancing lesions (p<0.01), while sHLA-G and IL-10 were more represented in MS patients without lesional activity on MRI scans (p<0.02). In MRI-inactive MS, CSF IL-10 mean concentrations were significantly greater in patients with CSF-detectable levels of sHLA-G than in those without any evidence of CSF sHLA-G expression (p<0.05). Our findings suggest that CSF classical sHLA-I and non-classical sHLA-G levels may modulate MS activity as assessed by MRI acting in opposite directions. The association observed between sHLA-G and IL-10 when Gd-enhancing lesion resolved indicates a potential immunoregulatory role for IL-10 in the control of MS disease activity by shifting the sHLA-I/sHLA-G balance towards sHLA-G response.

Hippocampal FGF-2 and BDNF overexpression attenuates epileptogenesis-associated neuroinflammation and reduces spontaneous recurrent seizures.

Under certain experimental conditions, neurotrophic factors may reduce epileptogenesis. We have previously reported that local, intrahippocampal supplementation of fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF) increases neurogenesis, reduces neuronal loss, and reduces the occurrence of spontaneous seizures in a model of damage-associated epilepsy. Here, we asked if these possibly anti-epileptogenic effects might involve anti-inflammatory mechanisms. Thus, we used a Herpes-based vector to supplement FGF-2 and BDNF in rat hippocampus after pilocarpine-induced status epilepticus that established an epileptogenic lesion. This model causes intense neuroinflammation, especially in the phase that precedes the occurrence of spontaneous seizures. The supplementation of FGF-2 and BDNF attenuated various parameters of inflammation, including astrocytosis, microcytosis and IL-1β expression. The effect appeared to be most prominent on IL-1β, whose expression was almost completely prevented. Further studies will be needed to elucidate the molecular mechanism(s) for these effects, and for that on IL-1β in particular. Nonetheless, the concept that neurotrophic factors affect neuroinflammation in vivo may be highly relevant for the understanding of the epileptogenic process.

Localized overexpression of FGF‐2 and BDNF in hippocampus reduces mossy fiber sprouting and spontaneous seizures up to 4 weeks after pilocarpine‐induced status epilepticus

Purpose:  We have recently reported that viral vector–mediated supplementation of fibroblast growth factor‐2 (FGF‐2) and brain‐derived neurotrophic factor (BDNF) in a lesioned, epileptogenic rat hippocampus limits neuronal damage, favors neurogenesis, and reduces spontaneous recurrent seizures. To test if this treatment can also prevent hippocampal circuit reorganization, we examined here its effect on mossy fiber sprouting, the best studied form of axonal plasticity in epilepsy.

Affinity cytochemistry visualizes specific estrogen binding sites on the plasma membrane of breast cancer cells

Abstract A study has been initiated on mapping specific interaction of estrogen with the plasma membrane of estrogen-target cells. Fluorescent estrogen analogues have been used in order to obtain the dynamic display and positioning of estrogen binding sites at the surface of intact breast cancer cells. The binding of these fluorescent ligands to the plasma membrane shows a major saturable component with structural specificity for natural estrogen. Moreover, estrogen binding sites display a temperature-sensitive lateral mobility in the plane of the membrane, leading to the formation of small clusters, larger patches and polar caps. Different steroid specificity indicates that these binding sites on the plasma membrane are distinct from classical cytosol estrogen-receptors. The actual function of these estrogen binding sites is unknown, but their location and properties are at least consistent with the idea that they might be involved in the cell control by estrogen.

FGF-2 Overexpression Increases Excitability and Seizure Susceptibility but Decreases Seizure-Induced Cell Loss

Fibroblast growth factor 2 (FGF-2) has multiple, pleiotropic effects on the nervous system that include neurogenesis, neuroprotection and neuroplasticity. Thus, alteration in FGF-2 expression patterns may have a profound impact in brain function, both in normal physiology and in pathology. Here, we used FGF-2 transgenic mice (TgFGF2) to study the effects of endogenous FGF-2 overexpression on susceptibility to seizures and to the pathological consequences of seizures. TgFGF2 mice display increased FGF-2 expression in hippocampal pyramidal neurons and dentate granule cells. Increased density of glutamatergic synaptic vesicles was observed in the hippocampus of TgFGF2 mice, and electrophysiological data (input/output curves and patch-clamp recordings in CA1) confirmed an increase in excitatory inputs in CA1, suggesting the presence of a latent hyperexcitability. Indeed, TgFGF2 mice displayed increased susceptibility to kainate-induced seizures compared with wild-type (WT) littermates, in that latency to generalized seizure onset was reduced, whereas behavioral seizure scores and lethality were increased. Finally, WT and TgFGF2 mice with similar seizure scores were used for examining seizure-induced cellular consequences. Neurogenesis and mossy fiber sprouting were not significantly different between the two groups. In contrast, cell damage (assessed with Fluoro-Jade B, silver impregnation and anti-caspase 3 immunohistochemistry) was significantly lower in TgFGF2 mice, especially in the areas of overexpression (CA1 and CA3), indicating reduction of seizure-induced necrosis and apoptosis. These data suggest that FGF-2 may be implicated in seizure susceptibility and in seizure-induced plasticity, exerting different, and apparently contrasting effects: favoring ictogenesis but reducing seizure-induced cell death.

Different production of soluble HLA‐G antigens by peripheral blood mononuclear cells in ulcerative colitis and Crohn's disease: A noninvasive diagnostic tool?

Background: HLA‐G antigens are nonclassical major histocompatibility complex (MHC) class I molecules characterized by tolerogenic and antiinflammatory properties. Recently, a different expression of HLA‐G antigens has been observed between intestinal biopsies of ulcerative colitis (UC) and Crohns disease (CD) patients. These data suggested a functional role for HLA‐G molecules in the diseases and proposed the HLA‐G modulation as a marker for the diagnosis of UC and CD. The soluble HLA‐G antigens (sHLA‐G) are circulating molecules mainly produced by activated peripheral blood CD14+ monocytes. Methods: We tested, by specific enzyme‐linked immunosorbent assay (ELISA), the sHLA‐G molecule levels in the supernatants of unstimulated and bacterial lipopolysaccharide (LPS)‐stimulated cultures of peripheral blood mononuclear cells (PBMC) from 30 healthy subjects, 10 CD, and 18 UC patients. The data were not influenced by treatment or disease activity. Results: The results confirmed a different sHLA‐G expression between the diseases, with a spontaneous secretion of sHLA‐G in CD patients but not in UC and healthy subjects. Moreover, a lack of sHLA‐G antigens has been reported in UC patient cultures after LPS activation but not in healthy subjects and CD patients. The defective sHLA‐G production was related to an impaired IL‐10 secretion in UC but not in CD. Conclusions: Overall, these results confirm the presence of a different biological characteristic between CD and UC patients and suggest sHLA‐G production by PBMC as a noninvasive diagnostic tool in the early phases of the diseases.

Sweet's Syndrome: A Retrospective Clinical, Histopathological and Immunohistochemical Analysis of 11 Cases

The aim of this paper is to report our clinical experience of Sweets syndrome, a severe dermatological disease which may be extremely important to recognize for the early diagnosis of a neoplastic disorder. Eleven patients affected by Sweets syndrome, treated at the Department of Dermatology, University of Ferrara, Ferrara, Italy, during 1998 to 2004, were evaluated. A retrospective analysis was performed. Data on age, sex distribution, clinical data, histopathological and immunohistochemical findings and therapy were collected. We observed one patient with idiopathic form, 5 patients affected by the para-inflammatory variant and 5 para-neoplastic cases (with haemoproliferative diseases). The cases with the para-inflammatory form were affected by minor infectious manifestations. Prolonged follow-up is necessary to verify that a case of idiopathic variant is not really a paraneoplastic form. Based on immunohistochemical analysis, we cannot exclude that true histiocytes, immunoreactive for CD68/PGM, infiltrate the dermis in Sweets syndrome lesions.

Pathophysiology of estrogen receptors in mammary tissue by monoclonal antibodies

Identification of preneoplastic lesions of the breast has mainly rested on morphological grounds, supported by epidemiological data. These studies assign a definite precancerous potential to a group of atypical hyperplastic lesions and in situ carcinoma. In spite of much effort no criteria are yet available to understand which, among these lesions, is committed to infiltrative growth, in other words, to understand the risk to a single patient. Estrogens are know to play a critical role in the etiology of breast cancer. The hypothesis is investigated that this role is dependent on a modified expression of their receptor. To approach this question estrogen receptor expression was traced by specific monoclonal anti-receptor antibodies and immunocytochemistry, on a spectrum of breast tissue changes, from normal tissue to infiltrating cancer. Estrogen receptor expression is heterogeneous in normal tissue and in infiltrating cancer, and on the contrary is homogeneous in proliferative atypical lesions and in in situ carcinomas. Present results show that receptor expression is enhanced and becomes homogeneous, maybe constitutive, in atypical hyperplasia and in in situ carcinoma and that this phenomenon could subserve important changes of proliferative capacity which are necessary and possibly sufficient for autonomous growth.