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The realization of a high side power switch for driving a motor with a load current of 200 A in a hostile environment is presented. For such high currents currently electromechanical devices are used which have reliability and wear problems when working in environments with high temperature and humidity. The proposed solution was developed by connecting in parallel five commercial switches mounted on an FR4 support. An accurate thermal design, aided by finite element analysis, made it possible to avoid the use of an external heat sink, thus minimizing the weight and cost of the assembled circuit. Experimental tests under actual operating conditions have demonstrated the reliability of the proposed solution.

The ability of cranial bone to repair defects of continuity is limited and it is mostly dependent on the age of the patient. In infancy and in early pediatric age, the scarce thickness of the calvarial bones and the need for a harmonic development of the child’s skull limit the application of most of the surgical procedures usually utilized in older patients. We tested the ability of mononucleated cells, derived from the patient’s bone marrow and transplanted on the site of the cranial bone defect, to increase the rate of mineralization of the autologous osteogenesis to obtain the complete restoration of the skull continuity.Four children, aged 26, 28, 37, and 79 months, respectively, affected by a stabilized and persistent cranial bone defect of posttraumatic or postsurgical origin, were treated. A sandwich-shaped shell, made of extrused absorbable polylactic copolymers material, was used to hold in place a freeze-dried mineralized collagen matrix associated with a nonceramic hydroxyapatite scaffold, where autologous bone marrow mononucleated cells were inseminated.In all patients, a rapid autologous bone osteogenesis was observed with a clear dimensional reduction of the bone defect few months after the autologous bone marrow cells seeding.The preliminary results of this research suggest the use of autologous bone marrow cells to increase the autologous osteogenesis in early pediatric age in cases in which correction of skull bone defects is best realized with autologous bone.

Introduction Acquired Chiari type-I malformation in hydrocephalic patients who have undergone surgical treatment was initially thought to depend on a craniocephalic disproportion induced by the cerebrospinal (CSF) shunt. However, most of the reports in the literature deal with children with lumbo-peritoneal shunts and emphasize the pathogenic role of the cranio–spinal pressure differential across the foramen magnum brought about by this type of shunt. Method In the present report, the authors describe two further cases of symptomatic acquired Chiari type-I malformation observed in two adolescents operated on for correction of pseudotumor cerebri in one (lumbo-peritoneal shunt) and of a suprasellar arachnoid cyst (cysto-ventriculo-peritoneal shunt) in the other. Results In both subjects, both the clinical manifestations and the cerebellar tonsillar herniation regressed after supratentorial cranial expansion, without the need for any manipulation of the shunt devices implanted earlier. Discussion These results, together with the observation of the concomitant upward and downward herniation of the cerebellum in both patients, indicate that secondary craniocephalic disproportion plays a relevant role in the genesis of acquired Chiari type-I malformation in children bearing extrathecal CSF shunts.

Abstract: With the advent of modern diagnostic tools for neuroimaging, the incidental detection of pineal cysts in asymptomatic subjects has increased. Only rarely do pineal cysts present with the clinical signs and symptoms of increased intracranial pressure or with neurological deficits in relation to compression and distortion of the adjacent nervous structures and cerebrospinal fluid pathways. While asymptomatic cysts are considered to be normal variants for which no further investigations are usually required, surgical treatment is suggested for symptomatic cysts, with the goal of eliminating the block in the cerebrospinal fluid circulation and/or the mass effect exerted by the lesion. In this report we describe a pediatric case of symptomatic pineal cyst, revealed by repeated episodes of headache caused by secondary obstructive hydrocephalus. Following an endoscopic third-ventriculostomy, serial magnetic resonance imaging studies demonstrated that not only had the ventriculomegaly resolved but also that the pineal cyst had regressed over time. A to-and-fro movement of fluid through the cyst wall, the direction of which depends on the equilibrium existing between the inner pressure of the cyst and the outer cerebrospinal fluid pressure, is suggested as a possible mechanism accounting for this unexpected result – to our knowledge, the first reported in literature.

Abstract: A number of craniosynostotic disorders have recently been ascribed to mutations in genes coding for the fibroblast growth factor receptors(FGFRs). The common feature of these FGFR-associated conditions is the unilateral or bilateral premature ossification of the coronal suture. One distinct craniosynostotic condition is trigonocephaly, which results from the premature fusion of the metopic suture. Trigonocephaly mostly occurs as isolated cranial defect; however, the premature closure of the metopic suture may represent a feature of more complex craniosynostotic conditions in which a progressive involvement of other cranial sutures with age is observed. The possible involvement of mutated FGFRs in trigonocephaly was investigated in nine newborns affected by isolated premature synostosis of the metopic suture. All except one of these cases carried no mutations in the FGFR1–3 domains indicated as hot spots for craniosynostosis-associated mutations. A T(978)C transition in the FGFR2 exon IIIa was found in a patient who had a phenotype that apparently fitted the trigonocephalic condition at birth, but showed additional facial anomalies, which worsened progressively with age towards a Crouzon-like profile. The present finding points out the importance, from both diagnostic and prognostic points of view, of early FGFR mutational screening in craniosynostotic conditions, even in forms that apparently do not involve closure of the coronal suture at birth.

Craniosynostoses are a heterogeneous group of disorders characterized by premature fusion of cranial sutures. Mutations in fibroblast growth factor receptors (FGFRs) have been associated with a number of such conditions. Nevertheless, the cellular mechanism(s) involved remain unknown. We analyzed cell proliferation and differentiation in osteoblasts obtained from patients with three genetically and clinically distinct craniosynostoses: Pfeiffer syndrome carrying the FGFR2 C342R substitution, Apert syndrome with FGFR2 P253R change, and a nonsyndromic craniosynostosis without FGFR canonic mutations, as compared with control osteoblasts. Osteoblasts from craniosynostotic patients exhibited a lower proliferation rate than control osteoblasts. P253R and nonsyndromic craniosynostosis osteoblasts showed a marked differentiated phenotype, characterized by high alkaline phosphatase activity, increased mineralization and expression of noncollagenous matrix proteins, associated with high expression and activation of protein kinase Cα and protein kinase Cε isoenzymes. By contrast, the low proliferation rate of C342R osteoblasts was not associated with a differentiated phenotype. Although they showed higher alkaline phosphatase activity than control, C342R osteoblasts failed to mineralize and expressed low levels of osteopontin and osteonectin and high protein kinase Cζ levels. Stimulation of proliferation and inhibition of differentiation were observed in all cultures on FGF2 treatment. Our results suggest that an anticipated proliferative/differentiative switch, associated with alterations of the FGFR transduction pathways, could be the causative common feature in craniosynostosis and that mutations in distinct FGFR2 domains are associated with an in vitroheterogeneous differentiative phenotype.

The results of an international multicenter study concerning the first complication of newly implanted cerebrospinal fluid shunts in nontumoral hydrocephalus are the subject of the present report. The authors have collected information on 773 cases from four continents. In particular, the following data were evaluated in relation to the general incidence of complications recorded in the first follow-up year: the patient's age at the operation, the etiology of hydrocephalus, the type of CSF shunt device used, and the modality of the surgical procedures. The overall complication rate in the series was 29%. Age and etiology of hydrocephalus appear to play a major role in influencing the complication rate; on the other hand, the choice of a specific CSF shunt device seems to be less important in this respect.

The authors describe their technique of dynamic CSF scanning utilizing the radionucleide material Tc-99m diethylentriamine-pentacetic acid (DTPA). Thirty-four infants with macrocephaly and enlarged intracranial CSF spaces were investigated with this technique. The resulting studies were graded according to severity. The grading scheme was of value in determining which patients would benefit from a CSF diversionary shunt.

Abstract: Post-haemorrhagic hydrocephalus is assumed to result from obstruction of the cerebrospinal fluid (CSF) pathways by blood clots and subsequent chronic infiltration with collagen. The aim of this work was to evaluate the possibility of preventing permanent shunt dependence by enhancing the endoventricular fibrinolysis by means of an endoventricular streptokinase infusion in babies affected by posthaemorrhagic ventricular dilatation. A case-control trial was carried out in 12 neonates affected by intraventricular haemorrhage and subsequent progressive ventriculomegaly. Six of them were treated with 20,000 U/day of streptokinase infused over 96 h through a percutaneous ventricular catheter. Our results show that the percentage of shunted babies was identical in treated and control patients despite the enhancement of endoventricular fibrinolysis obtained in all treated patients. On the basis of our results we do not recommend intraventricular streptokinase infusion for routine use in post-haemorrhagic ventricular dilatation.

Abstract: Pfeiffer syndrome is a skeletal disorder characterized by craniosynostosis associated with foot and hand anomalies. Mutations in the genes encoding fibroblast growth factor receptors 1 and 2 (FGFR1 and FGFR2) have recently been implicated in the aetiology of such a syndrome, as well as of other craniosynostotic conditions. We now report a novel missense mutation, a G to C transversion at position 1049 (exon IIIa) of FGFR2, detected in a patient with severe Pfeiffer clinical features. The mutation results in the substitution of a cysteine for tryptophan-290 in the third immunoglobulin-like domain and affects both spliceoforms of FGFR2. Mutations causing replacement of tryptophan-290 have also been reported previously in Crouzon syndrome, a similar but clinically distinct craniosynostotic disorder. This finding confirms the involvement of mutations of FGFR2 exon IIIa in Pfeiffer syndrome, and emphasizes both the extensive heterogeneity of the FGFR2 mutations that result in the Pfeiffer phenotype and the perturbations caused by unpaired cysteine residues in receptor dimerization and transduction of the FGFs signal.