Self-rewetting fluids with suspended carbon nanostructures.

Thermal management is very important in modern electronic systems. Recent researches have been dedicated to the study of the heat transfer performances of binary or multi-component heat transfer fluids with peculiar surface tension properties and in particular to "self-rewetting fluids," i.e., liquids with a surface tension increasing with temperature and concentration. Thermophysical properties like surface tension, wettability and thermal conductivity, at different temperatures, have been measured not only for binary mixtures, but also for a number of ternary aqueous solutions with relatively low freezing point and for nanoparticles suspensions (so called nanofluids). Some of them interestingly exhibit the same anomalous positive surface tension gradient with temperature as binary self-rewetting solutions. Since in the course of liquid/vapour phase change, self-rewetting fluids behaviour induces a rather strong liquid inflow (caused by both temperature and concentration gradients) from the cold region (where liquid condensates) to the hot evaporator region, several interesting applications may be envisaged, e.g., the development of advanced wickless heat pipes for utilization in reduced gravity environments. The present work is dedicated to the study of the thermophysical properties of nanofluids based on water/alcohol solutions with suspended carbon nanostructures, in particular single-wall carbon nanohorns (SWNH), synthesised by an homemade apparatus with an AC arc discharge in open air. The potential interest of the proposed studies stems from the large number of possible industrial applications, including space technologies and terrestrial applications, such as cooling of electronic components.

Transient oculomotor cranial nerves palsy in spontaneous intracranial hypotension.

Transient sixth cranial nerves palsy may occur in rare cases after lumbar puncture, spinal anesthesia and myelography as well as in more rare cases of spontaneous intracranial hypotension. We report three cases of spontaneous intracranial hypotension with sixth cranial nerves palsy. One of these patients presented also third cranial nerve palsy, never reported in spontaneous intracranial hypotension.

Immunological and endocrinological abnormalities in paraneoplastic disorders with involvement of the autonomic nervous system.

We report a series of four patients in whom the onset of systemic cancer was heralded by dysautonomic symptoms and a neurological non-metastatic complication mediated by immunological and endocrine factors. The series includes: a patient with acute leukaemia and autonomic sensory-motor polyradiculoneuropathy, a patient affected by colon carcinoma and autonomic neuropathy and limbic encephalitis, a patient with lung cancer and autonomic neuropathy and hypercalcaemic encephalopathy, a patient with small cell lung cancer associated with autonomic neuropathy in Lambert-Eaton Myasthenic Syndrome (LEMS) and syndrome of inappropriate ADH secretion (SIADH). We underline the prognostic importance and discuss the possible etiopathogenetic role of autonomic dysfunction, which is frequently associated with paraneoplastic neurologic syndromes of autoimmune and/or dysendocrine origin.

[Central pontine myelinolysis as potential complication of cerebellar astrocytoma: report of a case]. / La mielinolisi centrale pontina quale possibile complicanza di un astrocitoma cerebellare: descrizione di un caso.

Central pontine myelinolysis (CPM), a rare condition first observed by Adams et al. in 1959 in a group of malnourished chronic alcoholic subjects, has subsequently been seen in patients treated with thiazide diuretics, patients hyperhydrated postoperatively, and in other clinical situations. it is characterized by quadriplegia and pseudobulbar palsy which sometimes evolves into a locked-in syndrome. The rapid correction of severe hyponatremia (> 12 mmol/L/24 h) seems to be the causal factor, with consequent osmotic edema in the richly vascularized white matter of the pons as the proposed pathogenetic mechanism. We describe the case of a chronic psychotic man with nutritional disorders and inappropriate water intake who came to our attention for a clinical picture of CPM. Neuroradiological findings and postmortem studies revealed a slow-growing cerebellar astrocytoma in addition to the typical features of CPM. We discuss the hypothesis that damage to the nervous pathways and centers involved in water and electrolyte regulation could be the causal factor of CPM pathogenesis in this case.

The POEMS syndrome: report of six cases.

We report six patients affected by POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes), a peculiar multiorgan disease frequently associated with osteosclerotic myeloma or other plasma cell disorders. Sensorimotor polyneuropathy was associated with multisystem involvement in all of the patients, with osteosclerotic myeloma in 2 cases, monoclonal gammopathy of undetermined significance in 2 cases and Castleman's disease in the final two. In all of the patients, sural nerve biopsy findings were consistent with a mixed, axonal and demyelinating neuropathy. Increased levels of Interleukin-6 were found in two cases, but the pathogenesis of the disease is far from established.

Homozygous hypertrophic hereditary motor and sensory neuropathies.

We compared 25 autosomal dominant hereditary motor and sensory neuropathy (HMSN) type I patients with 7 subjects affected by hypertrophic HMSN with non-dominant inheritance. All the autosomal dominant HMSN I cases carried the chromosome 17p11.2 duplication, providing evidence that it is widely represented in HMSN I families. The second group included: two siblings born to unrelated, unaffected parents and suffering from hypertrophic HMSN of strikingly different severity; two sisters with HMSN I phenotype, born to first-cousin unaffected parents; two brothers with HMSN III phenotype born to unrelated parents both showing HMSN II phenotype; a child with classic HMSN III phenotype, born to unrelated, unaffected parents. The 17p11.2 duplication was not found in any of the patients of the second series or in their parents. Our data provide further evidence that: HMSN III is heterogeneous and encompasses the homozygous expressions of different neuropathic genes; it is advisable to separate autosomal recessive hypertrophic HMSN from dominant HMSN Ia, because they appear to be due to different DNA mutations.

HMSN III phenotype due to homozygous expression of a dominant HMSN II gene.

We describe two siblings with hereditary motor and sensory neuropathy (HMSN) type III. Their parents were both affected with autosomal dominant axonal HMSN. The neuropathy in the siblings probably resulted from homozygous expression of the HMSN II gene. Together with other reports of homozygous HMSN I, this family suggests that HMSN III is heterogenous and encompasses the most severe homozygous expression of neuropathic genes.

Peripheral nerve involvement in Churg-Strauss syndrome.

Peripheral neuropathy associated with bronchial asthma, multisystem organ dysfunction and idiopathic hypereosinophilia may be found in Churg-Strauss syndrome, hypereosinophilic syndrome and polyarteritis nodosa. Some authors have diagnosed their patients according to the presence in tissue biopsies of the three histological criteria of Churg and Strauss (necrotizing vasculitis, tissue eosinophilic infiltration, extravascular granulomas). We have observed three patients with a common history of a prodromal phase of allergic diseases (bronchial asthma and rhinitis) followed by a vasculitic phase with mononeuritis multiplex, purpura and arthritis, associated with hypereosinophilia of more than 1500 cells/mm3. All responded well to steroid treatment. Sural nerve biopsy revealed true vasculitis in two of these cases and a mild perivascular inflammatory infiltration in the other. On the basis of their characteristic clinical pattern, we think that our cases best fit the diagnosis of Churg-Strauss syndrome even though the typical histological features were not found in the sural nerves examined.

Hereditary motor and sensory neuropathy type I and type II.

In an attempt to clearly identify the different HMSN subgroups, we prospectively evaluated 128 subjects (46 index cases, 39 affected and 43 unaffected relatives) on clinical, genetic and electrophysiological grounds. The diagnosis of HMNS I or II was made in 77 patients. Differential diagnosis between type I and II patients was impossible on clinical grounds alone, but nerve conduction study showed a clear-cut subdivision into two populations. MCV behavior was consistent within families. Inheritance, autosomal dominant in almost all cases, was probably recessive in three HMSN I subjects and pedigree analysis pointed to X-linked transmission in one HMSN I family. We found no evidence for linkage to Duffy locus. We think that similar HMSN phenotypes can be determined by different gene defects. Ulnar nerve F-conduction velocity did not significantly differ from distal MCV in HMSN I: the evidence of a diffuse slowing of nerve conduction supports the hypothesis of a primary myelin defect.

Neurogenic muscle hypertrophy. Report of two cases.

Muscle hypertrophy is rare in denervating diseases. A patient with calf enlargement associated with L5-S1 radiculopathy and another with thenar, hypothenar, forearm and calf muscle hypertrophy in the course of chronic relapsing inflammatory demyelinating polyneuropathy are described. Gastrocnemius muscle biopsy revealed both type I and type II fibre hypertrophy in the former case and predominant type I fibre hypertrophy in the latter. Passive stretching and abnormal spontaneous muscular activity might have played a role in the origin of hypertrophy in both patients, but a satisfactory explanation for denervation hypertrophy has yet to be provided.

Epidural anaesthesia and spinal arachnoiditis.

Six patients were referred to our hospital with spinal arachnoiditis after epidural anaesthesia performed one month to 3 years before the onset of symptoms. None had had previous lumbar surgery or trauma, intraspinal haemorrhage, infections or other known causative factors of arachnoiditis. All the patients were free of neurological symptoms before epidural anaesthesia and only two had transient distress in the period immediately following the procedure. The clinical signs and symptoms of spinal arachnoiditis were severe and in every case the diagnosis was confirmed by myelography. Three patients were confined to a wheelchair after 3 years of follow-up. To our knowledge, the anaesthetic procedures were performed according to standard methods. Arachnoiditis seems to be due to the epidural injection of foreign substances, and may be related to anaesthetic-vasoconstrictor solution or contaminants.

Recurrent familial neuropathy due to liability to pressure palsies.

Two families with hereditary neuropathy with liability to pressure palsies (HNPP) were evaluated clinically, electrophysiologically and pathologically (2 index cases). Familial patterns suggest autosomal dominant inheritance. The clinical presentation is characteristic, with recurrent painless transitory mononeuropathy, without evident triggering factors, or caused by trivial trauma or pressure. In affected members neurophysiological studies showed diffuse slowing in nerve conduction, more evident at common sites of entrapment. Somatosensory evoked potentials (SEPs) showed bilateral peripheral abnormalities with proximal nerve involvement more pronounced in older patients. 40 to 75% of teased fibers displayed sausage-shaped swellings. Ultrastructurally some sausages showed redundant myelin loops and excessive number of myelin lamellae that seem to cause axonal constriction.