Secondary generalized epilepsy in childhood: EEG patterns and correlation with responsiveness to benzodiazepines or ACTH (preliminary note)

Secondary generalized epilepsy in childhood, characterized by absences or minor motor seizures, occurs in the forms of various syndromes, as defined by current classifications. EEG often shows continuous or subcontinuous paroxysmal activity associated with partly reversible psychomotor or mental regression. The paroxysmal activity can exhibit one of two distinct patterns: "organized" or "disorganized," although intermediate forms are common. The two patterns differ not only morphologically but also in the responsiveness to drug or hormone therapy, reactivity to stimuli, sleep changes and frequency of disordered slow rhythms. These features are illustrated by means of a survey of 10 cases.     

Presence of delayed myelination and macrocephaly in the sister of a patient with vacuolating leukoencephalopathy with subcortical cysts

Leukoencephalopathy with swelling and a discrepantly mild clinical course ("van der Knaap disease") is a recently identified syndrome. It is characterised by macrocephaly occurring during the first year of life, initially normal or nearly normal development, and slowly progressive ataxia and spasticity with initial preservation of intellectual functions. MRI shows diffuse abnormality in signal intensity, as well as swelling of the hemispheral white matter with subcortical cyst-like spaces in the fronto-parietal and anterior temporal areas. It is thought to have an autosomal recessive mode of inheritance, since many patients have consanguineous parents and more than one affected patient is often present within the same family. We report on two sibs: a 5-year old boy affected with "van der Knaap disease" and his macrocephalic sister whose first MRI (2 years 6 months) showed delayed myelination, which led us to suspect the same disease as her brother, however with subsequent normalisation at the second MRI (3 years 6 months).     

Oral pulsatile delivery systems based on swellable hydrophilic polymers.

Upon contact with aqueous fluids, swellable hydrophilic polymers undergo typical chain relaxation phenomena that coincide with a glassy-rubbery transition. In the rubbery phase, these polymers may be subject to swelling, dissolution and erosion processes or, alternatively, form an enduring gel barrier when cross-linked networks (hydrogels) are dealt with. Because of the peculiar hydration and biocompatibility properties, such materials are widely exploited in the pharmaceutical field, particularly as far as hydrophilic cellulose derivatives are concerned. In oral delivery, they have for long been employed in the manufacturing of prolonged release matrices and, more recently, for pulsatile (delayed) release devices as well. Pulsatile delivery, which is meant as the liberation of drugs following programmed lag phases, has drawn increasing interest especially in view of emerging chronotherapeutic approaches. In pursuit of pulsatile release, various design strategies have been proposed, chiefly including reservoir, capsular and osmotic formulations. In most cases, water-swellable polymers play a key role in the overall delivery mechanism after being activated by physiological media. Based on these premises, the aim of the present review is to survey the main oral pulsatile delivery systems, for which swelling, dissolution and/or erosion of hydrophilic polymers are primarily involved in the control of release.     

Leukoencephalopathy with swelling, megalencephalopathy and surprisingly mild course. A case report

Leukoencephalopathy with swelling and a discrepantly mild clinical course is a recently identified syndrome described by van der Knaap et al. It is characterised by macrocephaly occurring during the first year of life, initially normal or nearly normal development, slowly progressive ataxia and spasticity with initial preservation of intellectual functions. MRI shows diffuse abnormality of signal intensity in the hemisphere white matter with subcortical cyst-like spaces in the fronto-parietal and anterior temporal areas. The case of a 5-year-old boy whose clinical and neuroimaging findings are consistent with this syndrome is reported. The clinical and neuroimaging findings of this case may provide further information about this new syndrome which could possibly be useful also for genetic counselling.     

Ultrastructural changes in Langerhans cells in gingival overgrowth in cyclosporin A-treated renal transplant patients

AIM: Our research was focused on the ultrastructural features of gingival epithelium in kidney transplant patients and, in particular, on Langerhans cells, with the aim of verifying whether ultrastructural modifications might explain gingival overgrowth. METHODS: Using electron microscopy and immunohistochemical S100 staining at optical microscopy, we examined gingival samples obtained from 18 kidney transplant patients who presented with gingival overgrowth following cyclosporin A treatment. RESULTS: The hyperkeratosis shown by the epithelium, and especially the absence of Birbeck granules in the Langerhans cells observed in serial sections, lead us to correlate these data to an immunodeficiency which affects the epithelium in the complex mechanism determining overgrowth. CONCLUSIONS: In our previous studies we attributed the responsibility of overgrowth to the connective tissue alone. However, in the light of the present results, we cannot exclude a contribution of the epithelium to gingival overgrowth.     

Evidence for a proangiogenic activity of TNF-related apoptosis-inducing ligand

Starting from the observation that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2L protein is expressed in both malignant and inflammatory cells in some highly vascularized soft tissue sarcomas, the angiogenic potential of TRAIL was investigated in a series of in vitro assays. Recombinant soluble TRAIL induced endothelial cell migration and vessel tube formation to a degree comparable to vascular endothelial growth factor (VEGF), one of the best-characterized angiogenic factors. However, the proangiogenic activity of TRAIL was not mediated by endogenous expression of VEGF. Although TRAIL potentiated VEGF-induced extracellular signal-regulated kinase (ERK) phosphorylation and endothelial cell proliferation, the combination of TRAIL + VEGF did not show additive effects with respect to VEGF alone in inducing vessel tube formation. Thus, although TRAIL has gained attention as a potential anticancer therapeutic for its ability to induce apoptosis in a variety of cancer cells, our present data suggest that TRAIL might also play an unexpected role in promoting angiogenesis, which might have therapeutic implications.     

A study on the release mechanism of drugs from hydrophilic partially coated perforated matrices

Partially coated perforated systems (PCPS) based on low-viscosity hydroxypropyl methylcellulose (HPMC) as the polymeric material were formerly designed, prepared and evaluated in terms of in vitro behaviour. These systems proved to afford the pursued linear release with model drugs (metoprolol tartrate and benfluorex) of different solubility. To the aim of exploring the mechanisms concurring in the definition of zero-order kinetics, studies of drug release, polymer dissolution and medium penetration were performed on PCPS and constant release area systems (CRAS). According to the obtained results, PCPS release kinetics has to be mainly attributed to the progressive outward erosion of the core and to the related variation of the release area. The special geometry of the system, in fact, involves a gradual increase in the release surface, which allows the diffusional path lengthening to be offset. By properly selecting the shape and dimensions of the device as well as the physico-chemical characteristics of the hydrophilic polymer, the advantage of a zero-order release kinetics with programmable rate can be achieved.