Aspects on the integrative actions of the brain from neural networks to "brain-body medicine".

"Integration" is a key term in describing how nervous system can perform high level functions. A first condition to have "integration" is obviously the presence of efficient "communication processes" among the parts that have to be combined into the harmonious whole. In this respect, two types of communication processes, called wiring transmission (WT) and volume transmission (VT), respectively, were found to play a major role in the nervous system, allowing the exchange of signals not only between neurons, but rather among all cell types present in the central nervous system (CNS). A second fundamental aspect of a communication process is obviously the recognition/decoding process at target level. As far as this point is concerned, increasing evidence emphasizes the importance of supramolecular complexes of receptors (the so called receptor mosaics) generated by direct receptor-receptor interactions. Their assemblage would allow a first integration of the incoming information already at the plasma membrane level. Recently, evidence of two new subtypes of WT and VT has been obtained, namely the tunnelling nanotubes mediated WT and the microvesicle (in particular exosomes) mediated VT allowing the horizontal transfer of bioactive molecules, including receptors, RNAs and micro-RNAs. The physiological and pathological implications of these types of communication have opened up a new field that is largely still unexplored. In fact, likely unsuspected integrative actions of the nervous system could occur. In this context, a holistic approach to the brain-body complex as an indissoluble system has been proposed. Thus, the hypothesis has been introduced on the existence of a brain-body integrative structure formed by the "area postrema/nucleus tractus solitarius" (AP/NTS) and the "anteroventral third ventricle region/basal hypothalamus with the median eminence" (AV3V-BH). These highly interconnected regions operate as specialized interfaces between the brain and the body integrating brain-borne and body-borne neural and humoral signals.

Mild traumatic brain injury.

Traumatic Brain Injury (TBI) is among the most frequent neurological disorders. Of all TBIs 90% are considered mild with an annual incidence of 100­300/100.000. Intracranial complications of Mild Traumatic Brain Injury (MTBI) are infrequent (10%), requiring neurosurgical intervention in a minority of cases (1%), but potentially life-threatening (case fatality rate 0,1%). Hence, a true health management problem exists because of the need to exclude the small chance of a life threatening complication in large numbers of individual patients. The 2002 EFNS guidelines used a best evidence approach based on the literature until 2001 to guide initial management with respect to indications for CT, hospital admission, observation and follow up of MTBI patients. This updated EFNS guideline version for initial management inMTBI proposes a more selectively strategy for CT when major (dangerous mechanism, GCS<15, 2 points deterioration on the GCS, clinical signs of (basal) skull fracture, vomiting, anticoagulation therapy, post traumatic seizure) or minor (age, loss of consciousness, persistent anterograde amnesia, focal deficit, skull contusion, deterioration on the GCS) risk factors are present based on published decision rules with a high level of evidence. In addition clinical decision rules for CT now exist for children as well. Since 2001 recommendations, although with a lower level of evidence, have been published for clinical in hospital observation to prevent and treat other potential threads to the patient including behavioral disturbances (amnesia, confusion and agitation) and infection.

C2C12 myoblasts release micro-vesicles containing mtDNA and proteins involved in signal transduction.

Micro-vesicles can be released by different cell types and operate as 'safe containers' mediating inter-cellular communication. In this work we investigated whether cultured myoblasts could release exosomes. The reported data demonstrate, for the first time, that C2C12 myoblasts release micro-vesicles as shown by the presence of two exosome markers (Tsg101 and Alix proteins). Using real-time PCR analysis it was shown that these micro-vesicles, like other cell types, carry mtDNA. Proteomic characterization of the released micro-vesicle contents showed the presence of many proteins involved in signal transduction. The bioinformatics assessment of the Disorder Index and Aggregation Index of these proteins suggested that C2C12 micro-vesicles mainly deliver the machinery for signal transduction to target cells rather than key proteins involved in hub functions in molecular networks. The presence of IGFBP-5 in the purified micro-vesicles represents an exception, since this binding protein can play a key role in the modulation of the IGF-1 signalling pathway. In conclusion, the present findings demonstrate that skeletal muscle cells release micro-vesicles, which probably have an important role in the communication processes within skeletal muscles and between skeletal muscles and other organs. In particular, the present findings suggest possible new diagnostic approaches to skeletal muscle diseases.

Neurolupus is associated with anti-ribosomal P protein antibodies: an inception cohort study.

OBJECTIVE: Serum IgG antibodies (Abs) to phosphorylated ribosomal (P ribosomal) proteins have been inconsistently associated with neuropsychiatric manifestations in systemic lupus erythematosus (SLE). Our aim was to assess whether serum IgG Abs to ribosomal P proteins are associated with neuropsychiatric SLE. PATIENTS AND METHODS: We examined an inception cohort of 219 SLE patients. Neuropsychiatric SLE manifestations were characterized using the American College of Rheumatology (ACR) definition. Serum Abs to P ribosomal proteins were searched for by immunoblotting. In a subgroup of patients, Abs were investigated also in cerebrospinal fluid (CSF). RESULTS: Abs to P ribosomal proteins were detected in 45 (21%) patients, 23 of whom (51%) with neuropsychiatric involvement. Abs to P ribosomal protein were present both in serum and CSF. Abs to P ribosomal proteins significantly correlated with psychosis (p=0.017), mononeuropathy multiplex (p=0.040), malar rash (p=0.004), serum anti-Sm Abs (p=0.042), and lupus anticoagulant (p=0.036). SLE onset age was significantly younger in patients with Abs to P ribosomal proteins. Logistic regression analysis confirmed the relationship between Abs to P ribosomal proteins and psychosis, malar rash, SLE onset age and lupus anticoagulant. CONCLUSIONS: Abs to ribosomal P proteins are associated with psychosis and might be associated with peripheral nervous system complications.

Serum lipoprotein profile and APOE genotype in Alzheimer's disease.

Alterations in cholesterol homeostasis are associated with Alzheimer's disease (AD). The role played by specific fractions of serum lipoproteins in modifying the risk of AD, and the interaction with APOE genotype has not yet been investigated. We studied serum lipoprotein profiles using a gradient-density ultracentrifugation method in a cohort of late-onset sporadic AD patients without cerebrovascular lesions and in healthy elderly subjects. In the AD group the lipoprotein cholesterol distribution showed an increase in LDL cholesterol, reaching a significant difference with respect to controls in the LDL sub-fractions representing the transition between small dense-LDL (fraction 11, p = 0.04) and normal-density LDL particles (fraction 12, p = 0.03). APOE genotype and LDL cholesterol were independently associated with AD. The mean concentration of LDL in fractions 11 and 12 increased the risk of developing AD (p = 0.01 and p = 0.025, respectively). These results confirm that an alteration of cholesterol homeostasis is associated with AD and that serum concentrations of LDL cholesterol are higher in AD patients without cerebrovascular pathology than in elderly normal subjects. The presence of the APOE epsilon4+ allele is a risk factor for AD independent of increased serum cholesterol or a modification of other vascular risk factors. Increased levels of specific sub-fractions of LDL cholesterol may be associated with increased risk of AD.

Intrathecal IgM production at clinical onset correlates with a more severe disease course in multiple sclerosis.

The intrathecal synthesis of IgM, determined at clinical onset in patients with multiple sclerosis, was found to correlate with the degree of disability (as evaluated by means of the Expanded Disability Status Scale) reached 15 years later (p<0.001). Moreover, a significant inverse correlation was observed between the value of the IgM index and time to the first relapse (p<0.001) and the initiation of the progressive phase of the disease (p = 0.01). The prognostic value of IgM in the CSF is confirmed in previous reports as well as by our study. If these findings are confirmed in patients with multiple sclerosis in a larger series, a helpful biological marker for selecting patients for immunomodulatory treatments will be available to neurologists.

[99mTc]-HM-PAO SPECT in Parkinson's disease.

Thirty-six patients affected by Parkinson's disease were studied using single photon emission computed tomography (SPECT) and [99mTc]-HM-PAO as a tracer. The scanning procedure was performed 16-24 h after discontinuation of specific therapy. Tracer activity ratios were determined in 10 pairs of cerebellar, cortical, and subcortical regions. Data were compared with those of 10 age-matched controls. Most of the regions examined did not show any relevant change between parkinsonian and control subjects. Notably, mean activity in striatal regions were similar in the two groups. Increased activity in caudate-putamen was found in patients who were on chronic DOPA therapy. Side-to-side asymmetries in the basal ganglia increased with the severity of the disease. Significant reductions of tracer uptake, from control values, were observed bilaterally in the parietal cortex. These deficits were more pronounced in patients with mental deterioration and in subjects who had been chronically treated with anticholinergic drugs. Parietal perfusion deficits in parkinsonian patients resemble those described in Alzheimer's dementia. These findings suggest that the heterogeneous alterations of regional cerebral blood flow (rCBF) in parkinsonian patients reflect the multifactorial pathophysiology of the disease.

Reduced striatal dopamine receptors in Alzheimer's disease: single photon emission tomography study with the D2 tracer [123I]-IBZM.

Many patients with Alzheimer's disease (AD) develop parkinsonian symptoms, suggesting an overlapping between AD and Parkinson's disease (PD). However, pathologic and neurochemical studies indicate that the involvement of the dopamine system may be different in the two conditions. Using single photon emission tomography, we determined the relative specific striatal uptake (striatum to cerebellum ratio) of the D2 receptor ligand [123I]-IBZM in 15 AD patients without overt extrapyramidal symptoms (three subjects presented mild rigidity and bradykinesia) and nine age-matched controls. Mean specific activity in striatal regions of AD patients (1.35 +/- 0.09) was significantly reduced from control mean (1.59 +/- 0.03). Because such changes were evident even in the absence of overt parkinsonian symptomatology, our data indicate that alterations of striatal D2 receptors may be part of the pathologic abnormalities of AD. In addition, the mechanisms underlying extrapyramidal symptoms in AD (decline of postsynaptic striatal dopamine receptors) appear different from the prevalent presynaptic nigrostriatal alterations typical of PD.

Cerebral metabolic responses to clomipramine are greatly reduced following pretreatment with the specific serotonin neurotoxin para-chloroamphetamine (PCA). A 2-deoxyglucose study in rats.

To determine if reported reductions of regional cerebral metabolic rates for glucose (rCMRglc) induced by the tryciclic antidepressant clomipramine (CMI) (10 mg/kg) are due to a presynaptic action on serotonin (5-HT) terminals, 3-month-old Fischer-344 rats were given parachloroamphetamine (PCA), a serotonin neurotoxin. rCMRglc was measured 3 weeks later in 55 brain regions after the administration of saline or CMI using the quantitative autoradiographic [14C]2-deoxyglucose procedure. PCA alone increased rCMRglc in the visual cortex. CMI alone reduced rCMRglc in 18 (33%) of the studied regions, including telencephalic, diencephalic, limbic, and brain stem areas. In PCA-lesioned rats, metabolic responses to CMI (10 mg/kg) were greatly reduced, and significant rCMRglc decreases were observed only in 4 (7%) of the brain areas, including the hippocampus and raphe nuclei. Abolition by PCA of the metabolic responses to CMI confirms that CMI, at the dose studied, reduces rCMRglc via a presynaptic mechanism, likely the 5-HT reuptake sites.

The tricyclic antidepressant clomipramine dose-dependently reduces regional cerebral metabolic rates for glucose in awake rats.

The time course and the relation to dose of regional cerebral metabolic rates for glucose (rCMRglc) were measured in awake male Fischer-344 rats after administration of clomipramine (CMI), a serotonin (5-HT) uptake inhibitor and clinical antidepressant. rCMRglc was determined, using the quantitative autoradiographic [14C]2-deoxyglucose technique, in 64 brain regions at 20, 40, 60, 120, and 180 min after administration of CMI 50 mg/kg IP and 120 min after CMI 2 and 10 mg/kg IP. The peak metabolic effect was observed at 120 min after CMI. At that time, CMI 2 and 10 mg/kg IP significantly reduced rCMRglc from control values in 12 (19%) and 14 (22%) brain regions, which correspond to areas with high densities of 5-HT reuptake sites (e.g. visual and limbic areas and raphe nuclei). CMI 50 mg/kg produced widespread rCMRglc reductions in 34 (53%) brain regions, including cortical, hippocampal, raphe and cerebellar areas. The topographic distribution and the relation to time and dose of CMI effects on rCMRglc are different from those of 5-HT1A [8-hydroxy-2(di-N-propylamino) tetralin], 5-HT1B-C (m-chlorophenylpiperazine) and 5-HT3 (quipazine) agonists and resemble those produced by 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), an agonist of 5-HT2 receptors, suggesting that CMI may prefentially stimulate this 5-HT receptor subtype.

Amino acid uptake in vivo by the mouse brain and by various regions of the rabbit brain after drug-induced convulsions.

The levels of the free amino acids of the mouse brain were studied after convulsions induced by Metrazol; a decrease of level of taurine and a significant increase of level of alanine, phenylalanine and isoleucine were found. The net uptake of L-histidine by the mouse brain in vivo was similar under normal conditions and after Metrazol-induced generalized convulsions; that of L-methionine was much higher after convulsions and there was no uptake of L-aspartic acid, either under physiological conditions or after convulsions. The net uptake of L-histidine by various regions of the rabbit brain in vivo after convulsions was significantly higher than control values in the cortical areas, while that of L-methionine was significantly higher in the subcortical ones; there was no uptake of L-aspartic acid by the rabbit brain in normal condition, whereas after convulsions a small entry seemed to occur in the subcortical areas. These results indicate that cerebral permeability processes of amino acids are somewhat altered during convulsive phenomena, as already described elsewhere for ions andproteins.

The monosialoganglioside GM1 dose-dependently reduces regional cerebral metabolic rates for glucose in awake rats.

Using the quantitative autoradiographic [14C]2-deoxyglucose technique, regional cerebral metabolic rates for glucose (rCMRglc) were measured in awake male Fischer-344 rats at 1, 2, 3, 4 and 6 h after administration of GM1 30 mg/kg and at 3 h after GM1 150 or 300 mg/kg. GM1 is a natural compound that is able to prevent neuron degeneration induced by exposure to excitatory amino acids in vitro and by ischemia or neurotoxins in vivo. GM1 30 mg/kg, a dose very effective in preventing excitatory amino acid-induced neurotoxicity, produced minimal rCMRglc change over a 6 h period. GM1 150 and 300 mg/kg reduced rCMRglc, in 14 (31%) and in 29 (64%) brain regions, respectively. Maximal metabolic effects occurred in hippocampal areas which possess, in specific subfields, the highest brain concentrations of different excitatory amino acid receptor subtypes. This finding suggests an effect by GM1 on postreceptor mechanisms common to different excitatory amino acids.

Dose-dependent effects of buspirone on behavior and cerebral glucose metabolism in rats.

In this study we compared the effects of the anxiolytic buspirone on behavior and regional cerebral metabolic rates for glucose (rCMRglc) with those of the reference serotonin (5-HT)1A agonist 8-hydroxy-2(di-N-propylamino)tetralin (DPAT). Behavioral effects were assessed by scoring the 5-HT syndrome. rCMRglc was measured in 56 brain regions by using the quantitative autoradiographic [14C]2-deoxyglucose technique, at 10 min after i.p. injection of DPAT (1 mg/kg) or buspirone (0.4, 4 and 40 mg/kg) in awake male Fischer-344 rats. Whereas DPAT produced an intense 5-HT syndrome, buspirone had no behavioral effect. A low dose (0.4 mg/kg) of buspirone reduced rCMRglc in 18 brain areas (32%), more markedly in limbic areas and raphe nuclei. These were the only rCMRglc effects buspirone had in common with the potent 5-HT1A agonist DPAT and suggest that low dose buspirone activates preferentially 5-HT1A receptors. Hence, this receptor subtype may mediate buspirone functional effects on the limbic system and, given the role of these brain areas in mood control, possibly buspirone therapeutic actions. High doses (4 and 40 mg/kg) of buspirone produced widespread rCMRglc decreases in 46 (82%) and 44 (79%) of the areas studied and increased rCMRglc in one brain area, the lateral habenula, that was not affected by DPAT or a low dose of buspirone. The topographic distribution and direction of rCMRglc changes by high doses of buspirone differ from those produced by the 5-HT1A agonist DPAT. Instead these changes resemble the rCMRglc effects of dopaminergic D2 antagonists like haloperidol and are consistent with some pharmacological and binding properties of buspirone.(ABSTRACT TRUNCATED AT 250 WORDS)

Free light chains in the CSF in multiple sclerosis.

The presence of free light chains (FLC) was investigated in 32 patients with clinically definite or laboratory supported definite multiple sclerosis (MS), 2 patients with neurosyphilis and 10 normal controls. The detection of FLC in unconcentrated cerebrospinal fluid (CSF) was performed by means of agarose isoelectric focusing, followed by transfer of proteins to nitrocellulose membranes, double immunofixation, avidin-biotin amplification and peroxidase staining. Bands due to FLC were clearly demonstrated in the CSF of 28 MS patients; 3 of them showed only kappa FLC, 10 only lambda FLC, while 15 had both kappa and lambda FLC. The CSF of 4 MS patients was FLC negative. In both cases of neurosyphilis FLC bands were observed. FLC were never found in normal CSF. Among the indexes of intrathecal immunological activity (IgG oligoclonal bands, FLC, IgG index, intra-blood-brain barrier IgG synthesis rate, pleocytosis) the FLC proved to be the second most frequent abnormality in MS CSF, the presence of IgG oligoclonal bands being the first. In one MS case an FLC band was found, while all the other indexes of intrathecal IgG production were negative. A high correlation was found between an elevated number of FLC and pleocytosis. The presence of FLC in MS CSF seems to indicate a recent immunological stimulation leading to increased synthesis of FLC within the CNS.

The cerebrospinal fluid transferrin/tau proteins. A study by two-dimensional polyacrylamide gel electrophoresis (2D) and agarose isoelectrofocusing (IEF) followed by double-antibody peroxidase labeling and avidin-biotin amplification.

The cerebrospinal fluid (CSF) transferrin/Tau proteins were studied by two-dimensional polyacrylamide gel electrophoresis (2D) followed by immunoblotting and by agarose isoelectrofocusing (IEF), and subsequent double immunofixation, peroxidase staining and Avidin-Biotin Complex (ABC) amplification. The pattern of the Tau protein was similar but not equal to that of the transferrin (Tf). When a genetic variant of Tf was present in the serum, the same variant was also observed in the corresponding CSF Tf and in the Tau fraction. After neuraminidase treatment, both serum and CSF Tf moved to the Tau position on IEF and 2D. On 2D, no desialized precursors of the Tau proteins were detected, whereas the Tf precursors were always detected. No synthesis of the Tau globulin in the brain can, therefore, be inferred. In CSF not treated with neuraminidase, Tf is the only sialoglycoprotein clearly desialized, showing that the Tau fraction cannot be generated by neuraminidase action at CSF level. In fact, the treatment of serum and CSF proteins with neuraminidase produced a clear shift in the isoelectric mobility of all sialoglycoproteins. We clearly demonstrate that the Tau globulin is the result of neuraminidase activity not located in the CSF compartment. We suggest that Tf could be desialized by the action of neuraminidase at the brain level and then be "washed" into the CSF. Brain utilization of Tf, meeting the brain iron requirement, seems likely.

Evaluation of chronic levodopa therapy in Parkinson's disease.

Levodopa is the most useful drug for treatment of Parkinson's disease today, even if a progressive decline of therapeutic activity with the appearance of important side affects is a well known feature of the long-term levodopa therapy. Here we report our 15 year experience on uninterrupted treatment with levodopa. Among parkinsonian patients two groups of parkinsonian patients can be distinguished, one of them is dopa-sensitive and the other one is dopa-insensitive. The direct dopaminergic agents showed to be effective in the treatment of Parkinson's disease, particularly in the treatment of patients who are no longer satisfactorily responding to levodopa. We suggest to keep the dose of levodopa low, using the minimal effective dosage, for an optimal long-term management.

Alterations of striatal dopamine D2 receptors contribute to deteriorated response to L-dopa in Parkinson's disease: a [123I]-IBZM SPET study.

Single photon emission tomography with the ligand [123I]-IBZM was used to image central dopamine D2 receptors in Parkinson's disease patients. The aim was to assess striatal receptor densities in relation to response to L-Dopa therapy. In the parkinsonian patients group who were untreated until SPET study and in the group of patients with a sustained response to chronic L-Dopa, striatal [123I]-IBZM uptake did not differ significantly from mean values of the control group. On the contrary, significantly diminished uptake of [123I]-IBZM was found in the basal ganglia regions of the group of patients who developed a complicated/fluctuating response to chronic L-Dopa treatment. Our results indicate that striatal D2 receptor alterations in Parkinson's disease may contribute to the altered response to L-Dopa.

Uptake and life time of fluoride ion in rats by 19F-NMR.

19F nuclear magnetic resonance (NMR) was utilized to obtain information on the uptake and half-life time of fluoride ion in rats. Changes in tissue fluoride level after acute loading were monitored over time in blood and tissue homogenates obtained from liver and brain. The rate of fluoride elimination from various tissues was roughly similar, following in all cases a first-order kinetic rate law. The F- concentration in brain was about 20% of that found in liver, indicating a reduced fluoride diffusion across the blood-brain barrier. In vivo F- spectra were obtained in rat brain in few minutes with a good signal-to-noise ratio; this confirms the possibility of extending the use of F- as a probe of biomolecules to in vivo applications.

NMR method for superoxide dismutase assay in brain and liver homogenates.

A method for copper- and manganese-containing superoxide dismutase (Cu- and MnSOD) assay in tissue homogenates such as liver and brain, based on the measurement of the longitudinal nuclear relaxation time (T1) of F-, has been developed as a preliminary approach to in vivo measurement of these enzymes. The relaxation rate of F-, which increases linearly with the SOD concentration, also depends on the oxidation state of the metal ion present in the active site of the enzyme. The relaxivity values of the oxidized, reduced and turnovering CuSOD were found to be 9.6 x 10(6), much less than 1 x 10(2) and 5.2 x 10(6) M-1 s-1, respectively, while for MnSOD the corresponding values were 2.9 x 10(6), 4.2 x 10(6) and 3.6 x 10(6) M-1 s-1, respectively. These high relaxivity values allow the detection of SODs in brain and liver homogenates where, under aerobic conditions, these enzymes appear in the steady-state. The contribution of the two types of SOD to the F- relaxation rate in the homogenates was measured by addition of either diethyldithiocarbamate or cyanide, both of which selectively inhibit the CuSOD. The comparison between NMR and activity data confirmed the possibility of carrying out accurate and precise measurements of SODs in homogenates by NMR.

[Neurologic complications of diabetes mellitus]. / Le complicazioni neurologiche del diabete mellito.

Neurological complications in the light of their clinical and topographical pattern are discussed with regard to the literature and 40 personal cases. Peripheral neuropathy is the most common (average frequency 26%). The main clinical, anatomical, histological and pathogenetic features of polyneuritis in diabetes are illustrated. Diabetic amyotrophy is a true clinical entity, though its site (neural or muscular) and pathogenesis are still the subject of discussion. Cranial nerve damage (oculomotor paralysis in particular) has the typical clinical, anatomical and histological picture of peripheral forms. Myelopathy leads to three distinct anatomical and clinical patterns: pseudo-tabes caused by degeneration of the roots and posterior cords; chronic anterior poliomyelitis due to degeneration of the cells of the anterior cornua; myelosis attributable to combined degeneration of the posterior and anterolateral cords. The main features of encephalopathy and the relation between epilepsy and diabetes are also examined.