Functional and radiological outcomes after bridging therapy versus direct thrombectomy in stroke patients with unknown onset: Bridging therapy versus direct thrombectomy in unknown onset stroke patients with 10-point ASPECTS.

BACKGROUND AND PURPOSE: The aim was to assess functional and radiological outcomes after bridging therapy (intravenous thrombolysis plus mechanical thrombectomy) versus direct mechanical thrombectomy (MT) in unknown onset stroke patients. METHODS: A cohort study was conducted on prospectively collected data from unknown onset stroke patients who received endovascular procedures at ≤6 h from symptom recognition or awakening time. RESULTS: Of the 349 patients with a 10-point Alberta Stroke Program Early Computed Tomography Score (ASPECTS), 248 received bridging and 101 received direct MT. Of the 134 patients with 6-9-point ASPECTS, 123 received bridging and 111 received direct MT. Each patient treated with bridging was propensity score matched with a patient treated with direct MT for age, sex, study period, pre-stroke disability, stroke severity, type of stroke onset, symptom recognition to groin time (or awakening to groin time), ASPECTS and procedure time. In the two matched groups with 10-point ASPECTS (n = 73 vs. n = 73), bridging was associated with higher rates of excellent outcome (46.6% vs. 28.8%; odds ratio 2.302, 95% confidence interval 1.010-5.244) and successful recanalization (83.6% vs. 63%; odds ratio 3.028, 95% confidence interval 1.369-6.693) compared with direct MT; no significant association was found between bridging and direct MT with regard to rate of symptomatic intracerebral hemorrhage (0% vs. 1.4%). In the two matched groups with 6-9-point ASPECTS (n = 45 vs. n = 45), no significant associations were found between bridging and direct MT with regard to rates of excellent functional outcome (44.4% vs. 31.1%), successful recanalization (73.3% vs. 76.5%) and symptomatic intracerebral hemorrhage (0% vs. 0%). CONCLUSIONS: Bridging at ≤ 6 h of symptom recognition or awakening time was associated with better functional and radiological outcomes in unknown onset stroke patients with 10-point ASPECTS.

The impact of tumour histology and recursive partitioning analysis classification on the prognosis of patients treated with whole-brain hypofractionated radiotherapy for brain metastases: analysis of 382 patients.

PURPOSE: Recursive partitioning analysis (RPA) is a prognostic index capable of predicting survival in patients with brain metastases. Histology of the primary tumour has only recently been introduced among the factors that could potentially affect the prognosis of these patients. The main purpose of this study was to analyse the impact of RPA in correlation with histology of the primary tumour in patients with brain metastases treated with hypofractionated radiotherapy. MATERIALS AND METHODS: A total of 382 patients were treated at the Department of Radiotherapy of Brescia University, and RPA classes were retrospectively assigned to all patients. Univariate and multivariate analyses were then performed to verify the role of the single prognostic variables, for the entire group and for each prognostic class, as well as in correlation with histology of the primary tumour. RESULTS: Most patients were classified as RPA prognostic class 2 (48%). The majority of patients was treated with a total dose of 30 Gy delivered in ten fractions, whereas the dose of 20 Gy in four or five fractions was primarily used in patients classified as RPA class 3. At univariate analysis, the main variable correlating with overall survival (OS) was RPA class (p=0.000). Uni- and multivariate analysis performed on RPA class 1 patients only confirmed the role of general performance status, number of metastases and total radiotherapy dose for predicting OS. In the group with the worst prognosis (RPA class 3), none of the variables had a statistically significant role in improving OS. Tumour histology and radiotherapy dose influence OS, even in RPA class 1 and 2 patients. CONCLUSIONS: This analysis confirms that RPA prognostic class is the factor that most predicts survival. Primary tumour histology helps determine prognosis, especially in RPA prognostic classes 1 and 2. As regards RPA class 3, no factor influences survival prognosis.

Multiple sclerosis: Fas signaling in oligodendrocyte cell death.

Fas is a cell surface receptor that transduces cell death signals when cross-linked by agonist antibodies or by fas ligand. In this study, we examined the potential of fas to contribute to oligodendrocyte (OL) injury and demyelination as they occur in the human demyelinating disease multiple sclerosis (MS). Immunohistochemical study of central nervous system (CNS) tissue from MS subjects demonstrated elevated fas expression on OLs in chronic active and chronic silent MS lesions compared with OLs in control tissue from subjects with or without other neurologic diseases. In such lesions, microglia and infiltrating lymphocytes displayed intense immunoreactivity to fas ligand. In dissociated glial cell cultures prepared from human adult CNS tissue, fas expression was restricted to OLs. Fas ligation with the anti-fas monoclonal antibody M3 or with the fas-ligand induced rapid OL cell membrane lysis, assessed by LDH release and trypan blue uptake and subsequent cell death. In contrast to the activity of fas in other cellular systems, dying OLs did not exhibit evidence of apoptosis, assessed morphologically and by terminal transferase-mediated d-uridine triphosphate-biotin nick-end-labeling staining for DNA fragmentation. Other stimuli such as C2-ceramide were capable of inducing rapid apoptosis in OLs. Antibodies directed at other surface molecules expressed on OLs or the M33 non-activating anti-fas monoclonal antibody did not induce cytolysis of OLs. Our results suggest that fas-mediated signaling might contribute in a novel cytolytic manner to immune-mediated OL injury in MS.

Iodine Extravasation Quantification on Dual-Energy CT of the Brain Performed after Mechanical Thrombectomy for Acute Ischemic Stroke Can Predict Hemorrhagic Complications.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage represents a potentially severe complication of revascularization of acute ischemic stroke. The aim of our study was to assess the capability of iodine extravasation quantification on dual-energy CT performed immediately after mechanical thrombectomy to predict hemorrhagic complications. MATERIALS AND METHODS: Because this was a retrospective study, the need for informed consent was waived. Eighty-five consecutive patients who underwent brain dual-energy CT immediately after mechanical thrombectomy for acute ischemic stroke between August 2013 and January 2017 were included. Two radiologists independently evaluated dual-energy CT images for the presence of parenchymal hyperdensity, iodine extravasation, and hemorrhage. Maximum iodine concentration was measured. Follow-up CT examinations performed until patient discharge were reviewed for intracerebral hemorrhage development. The correlation between dual-energy CT parameters and intracerebral hemorrhage development was analyzed by the Mann-Whitney U test and Fisher exact test. Receiver operating characteristic curves were generated for continuous variables. RESULTS: Thirteen of 85 patients (15.3%) developed hemorrhage. On postoperative dual-energy CT, parenchymal hyperdensities and iodine extravasation were present in 100% of the patients who developed intracerebral hemorrhage and in 56.3% of the patients who did not (P = .002 for both). Signs of bleeding were present in 35.7% of the patients who developed intracerebral hemorrhage and in none of the patients who did not (P < .001). Median maximum iodine concentration was 2.63 mg/mL in the patients who developed intracerebral hemorrhage and 1.4 mg/mL in the patients who did not (P < .001). Maximum iodine concentration showed an area under the curve of 0.89 for identifying patients developing intracerebral hemorrhage. CONCLUSIONS: The presence of parenchymal hyperdensity with a maximum iodine concentration of >1.35 mg/mL may identify patients developing intracerebral hemorrhage with 100% sensitivity and 67.6% specificity.

The efficiency of translation termination is determined by a synergistic interplay between upstream and downstream sequences in Saccharomyces cerevisiae.

In a recent study we found that the efficiency of translation termination could be decreased several hundred fold by altering the local sequence context surrounding stop codons in the yeast Saccharomyces cerevisiae. Suppression of termination was shown to be mediated by near-cognate tRNA mispairing with the termination codon. We have now examined in greater detail how the local sequence context affects the efficiency of translation termination in this organism. Our results indicate that the sequence immediately upstream of the termination codon plays a significant role in determining the efficiency of translation termination. An extended termination sequence (containing the stop codon and the following three nucleotides) was also found to be a major determinant of termination efficiency, with effects attributable to the fourth nucleotide being largely independent of the termination codon. For the UGA and UAA stop codons, the influence of the fourth position on termination efficiency (from most efficient to least efficient termination) was found to be G > U,A > C, while for the UAG codon it was U,A > C > G. These sequence-specific effects on the efficiency of translation termination suggest that polypeptide chain release factor (or another molecule that may play a role in translation termination, such as rRNA) recognizes an extended termination sequence in yeast. A previous study found a statistically significant bias toward certain tetranucleotide sequences (containing the stop codon and the first distal nucleotide) in several organisms. We found that tetranucleotide sequences most frequently used in yeast are among the most efficient at mediating translation termination, while rare tetranucleotide sequences mediate much less efficient termination. Taken together, our results indicate that upstream and downstream components of an extended sequence context act synergistically to determine the overall efficiency of translation termination in yeast.

Inherited neuroaxonal dystrophy in C6 deficient rabbits.

We report the occurrence of a progressive neurological syndrome clinically characterized by subacute motor neuropathy in offspring of C6 deficient rabbits. On the basis of the pedigree analysis, the disease appears to be genetically transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: 1) severe axonal degeneration in the sciatic nerve system involving mainly motor fibers; 2) occasional peripheral axonal enlargement closely associated with axonal degeneration; 3) presence of structured abnormal material in normal-size myelinated fibers of central nervous system (CNS) and peripheral nervous system (PNS); and 4) widespread occurrence of dystrophic axons and axonal spheroids in the gray matter of CNS. By ultrastructural examination, dystrophic axons are filled with tubulovesicular material, stalks of parallel membranes and dense bodies similar to what is described in human neuroaxonal dystrophies (NAD). The disease manifested by C6 deficient rabbits may represent an animal model of primary human NAD.

Experimental induction of myelin changes by anti-MAG antibodies and terminal complement complex.

We investigated the role of anti-myelin-associated glycoprotein (MAG) IgM and complement (C) in the pathogenesis of myelin alterations occurring in patients with anti-MAG-associated polyneuropathy. For this purpose, we separately studied the effects of anti-MAG antibodies and terminal C complex (TCC) after injection into the rabbit sciatic nerve. The two different local treatments produced identical ultrastructural abnormalities such as intramyelinic edema, myelin vesiculation and, in particular, separation of the major dense lines with the formation of widely spaced myelin, a peculiar feature encountered in human peripheral nerve disorders with circulating anti-myelin monoclonal IgM. In nerves treated with anti-MAG IgM ultrastructural myelin alterations were concurrent with activation of the rabbit's own C to the formation of TCC. Contrary to the immunological and ultrastructural findings obtained in C-sufficient animals, in C6-deficient rabbits injected with anti-MAG IgM no myelin alterations nor C completion were observed. This study identifies anti-MAG IgM as the mediator and the C as the effector of myelin changes observed in the present model and, for extension, in human neuropathies associated with anti-MAG IgM.

Tumor necrosis factor alpha and human Schwann cells: signalling and phenotype modulation without cell death.

The aim of the study was to evaluate the biological response of human Schwann cells (SC) to tumor necrosis factor alpha (TNFalpha) in vitro and to the inflammatory milieu of chronic inflammatory demyelinating polyradiculoneuritis (CIDP). By immunocytochemical and functional assays, we found that SC expressed TNF receptors and that TNFalpha promoted in SC cultures transient activation of transcription factors NFkappaB and c-jun in the absence of apoptosis. In addition, TNFalpha significantly increased the proportion of non-myelin-forming SC expressing the p75 nerve growth factor receptor. Such phenotypic effect was dose-dependent and partially mediated by NFkappaB, as assessed by functional blockage with acetylsalicylic acid. We then extended our study to a human disease in which SC are exposed to TNFalpha. Increased signals for NFkappaB, but not c-jun, molecules were observed by immunohistochemistry on SC nuclei in nerve biopsies from patients with CIDP, as compared with controls. Irrespective of the presence of nerve inflammation, SC showed no evidence of apoptosis. Taken together, our results suggested that SC are potential targets of TNFalpha and that this cytokine exerted no cytotoxic effects either in vivo or in vitro. Rather, TNFalpha may influence the fate of SC by activating transcriptional pathways and modulating their phenotype.

Astrocytes upregulate glial fibrillary acidic protein (GFAP), but not insulin-like growth factor-I (IGF-I) during experimental autoimmune neuritis (EAN).

T cell-mediated autoimmune neuritis produces rapid activation of spinal cord microglia. To determine whether this microglial response upregulates astrocytic expression of IGF-related proteins, we induced EAN and used in situ hybridization and immunocytochemistry to examine the mRNAs and peptides for glial fibrillary acidic protein (GFAP), insulin-like growth factor-I (IGF-I), IGF-I receptor (IGFR-I) and IGF binding protein-2 (IGFBP-2). Relative levels of GFAP mRNA and peptide were highest in the lumbar spinal cord 4-10 d following T cell transfer and significant GFAP elevations were still present after three weeks. The astrocytes expressing GFAP mRNA and peptide were localized around motoneurons which were related topographically to axons in peripheral nerve inflammatory lesions. In the nucleus gracilis, where terminals of dorsal root ganglion neurons are located, astrocytic levels of GFAP mRNA and peptide rose later and did not reach their highest levels until 21 d after T cell transfer. Even though microglia were activated in both locations 2-4 d after transfer, astrocytic levels of IGF-I, IGFR-I and IGFBP-2 mRNA and peptide did not differ significantly from those observed in controls. The dissociation of GFAP and IGF-I expression in EAN suggests that these astrocytic responses may be independently regulated. We also suggest that the type and severity of remote neuronal injury are probably more important inducers and regulators of these astrocytic responses than microglial cell activation.

Hepatitis C virus infection and myositis: a virus localization study.

We report a case of myositis associated with chronic hepatitis C virus infection. Muscle biopsy and immunohistochemistry showed perifascicular atrophy, few necrotic and regenerating fibres, scarce perivascular infiltrates, deposits of immunoglobulin G, C3, fibrinogen and MAC in muscle vessel walls, and non-uniform expression of major histocompatibility complex-I antigens among muscle fibres. Hepatitis C virus NS3 antigen and hepatitis C virus RNA were detected in infiltrating cells but not within muscle fibres or endothelial cells. Our findings suggest that humoral-mediated immune mechanisms, not directly related to hepatitis C virus infection of muscle structures, may sustain the local inflammatory reaction in this patient.

T-cell-mediated epineurial vasculitis and humoral-mediated microangiopathy in cryoglobulinemic neuropathy.

We used immunohistochemistry to assess the role of humoral and cellular factors in endoneurial microangiopathy and epineurial vasculitis in 15 nerve biopsies of patients with axonal neuropathy and monoclonal or mixed cryoglobulinemia (CG). Deposition of immunoglobulins and cytolytic complement was detected in endoneurial capillaries of patients with mixed CG. Epineurial inflammatory infiltrates containing beta2-integrin-positive lymphocytes and monocytes surrounded arterioles expressing cell adhesion molecules, thus suggesting a cell-mediated pathogenesis of the epineurial vasculitis. On the other hand, the absence of immune complex deposition and polymorphonuclear elements suggests a minor role for the humoral mechanisms in the formation of the vasculitic lesions. This study indicates that both cell-mediated mechanisms and immune complexes/cryoglobulins are involved, although at different levels, in the pathogenesis of CG neuropathy.

Phenotypic and functional properties of gamma delta T cells from patients with Guillain Barré syndrome.

In this study we have examined the phenotypic and functional properties of circulating gamma delta T cells in patients with Guillain Barre syndrome (GBS), in normal healthy controls, and in patients with active multiple sclerosis (MS). Cells expressing the Vdelta2 T cell receptor showed elevated expression of the C-lectin receptor NKRP1A in both GBS and MS, suggestive of an activated state. However, in patients with GBS these cells failed to respond to pyrenil-pyrophosphate derivatives and Vdelta2 + T cell clones derived from these patients released lower levels of IFNgamma than Vdelta2 + clones derived from controls and MS patients. In contrast, in patients with GBS the Vdelta1 + subset was expanded, showed elevated expression of NKRPIA and Vdelta1 + clones derived from these patients secreted high levels of IL-4. Our findings of expanded NKRP-1A +, IL-4-producing Vdelta1 T cells in the GBS patients suggests the possibility that these cells are activated by the recognition of non-protein antigens in an MHC-unrestricted manner and contribute to the humoral response to glycolipids that is a hallmark of this disease.

Evidence for a role of gammadelta T cells in demyelinating diseases as determined by activation states and responses to lipid antigens.

In this report we review current information on the phenotypic and functional properties of gammadelta T cells in demyelinating disorders. The results support the conclusion that although gammadelta T cells show evidence of activation in patients with either multiple sclerosis (MS) or Guillain Barrè syndrome (GBS), differences exist in the phenotypic and functional properties of these cells between the two diseases. In particular, our data indicate that in patients with MS the Vdelta2 subset is activated and that these cells can be induced to secrete high levels of proinflammatory cytokines. In contrast, in patients with GBS, the Vdelta1 subset is expanded and can be induced to secrete cytokines more associated with a humoral response.

Hepatitis C virus infection of peripheral nerves in type II cryoglobulinaemia.

Peripheral neuropathy is a frequent complication in patients suffering from type II mixed cryoglobulinaemia (mCGII), a sort of vasculitis that is strongly associated with hepatitis C virus (HCV) infection and characterised by high concentrations of anti-HCV antibodies and HCV RNA in the cryoprecipitates. We report the finding of HCV RNA in homogenates of nerve biopsies from five such patients, by reverse transcription-polymerase chain reaction (RT-PCR) amplification of different regions of the viral genome. HCV RNA was localized in epineurial cells by in situ RT-PCR. Our data suggest that HCV infection of nerves plays a major role in mCGII-associated neuropathy.

Human peripheral nerve macrophages in normal and pathological conditions.

We investigated, by immunocytochemistry and immune electron microscopy, the immunophenotype, morphology and functional properties of human peripheral nervous system (PNS) macrophages (M phi) under normal and pathological conditions. Endoneurial M phi disclosed an elongated, ramified morphology, with the main processes oriented along the major axis of nerve fibers; they shared several lineage-related and functional markers with monocyte/macrophages and central nervous system (CNS) microglia, including CD4, CR3, CR4 and FcRIII. In addition, basal expression of HLA-DR antigens was exclusively confined to M phi in normal PNS. In the course of unrelated pathological conditions, resident M phi underwent activation with transformation to hypertrophic cells or foamy phagocytes and up-regulation of the markers expressed in normal conditions; new expression of a macrophagic antigen was detected on activated M phi. In different neuropathies, HLA-DR expression was also detected on non-myelin forming Schwann cells with ultrastructural features indicative of denervation. The present results demonstrate that the human PNS is provided with an intrinsic population of immunocompetent and potentially phagocytic M phi, which represent the peripheral counterpart of CNS microglia.

Cytoskeletal changes and ubiquitin expression in dystrophic axons of Seitelberger's disease.

Central nervous system specimens of 4 cases of Infantile Neuroaxonal Dystrophy (Seitelberger's disease) were processed for Bodian's silver stain and for immunostaining with antibodies against neurofilaments (NF), tubulin and ubiquitin (UBQ). Reactivity to NF and UBQ was restricted to spheroids of small size; swellings larger than 30 mu were negative, in spite of their positivity to Bodian's silver stain. Reactivity to tubulin was evident only in normal fibers, whereas no positive material was observed in dystrophic axons. These findings suggest that loss of microtubules (MT) and denaturation of NF might play a crucial role in the mechanisms responsible for the formation of axonal spheroids; in addition the focal activation of the UBQ system suggests an attempt of the neuron to remove abnormal material even at sites remote from the perikaryon.

Peripheral nerve vasculitis: a clinico-pathological study.

The clinico-pathological findings of 20 nerve biopsies consecutively performed at the neuropathological laboratory of Verona University Hospital were reviewed in order to establish the most important clinical manifestations of peripheral nerve vasculitis and to determine the role of biopsy in corroborating the diagnosis. Dystal sensori motor polyneuropathy was the most frequent clinical manifestation, confirming previous clinico-pathological studies and suggesting a more widespread pathological process than usually supposed. The biopsy was the basis of the diagnosis since it established or substantially modified the clinical diagnosis. Therefore we suggest that in cases with suspected vasculitis of the peripheral nerve the biopsy makes a useful contribution to diagnosis.

Multiple sclerosis: expression of molecules of the tumor necrosis factor ligand and receptor families in relationship to the demyelinated plaque.

The molecules that comprise the tumor necrosis factor ligand and receptor (TNF-L and TNF-R) families play important roles in tissue homeostasis and in multiple sclerosis (MS). For example, levels of the TNF ligand (TNF alpha; cachectin) correlate with disease progression and lymphotoxin (LT, TNF beta) has been localized in MS lesions. Members of the TNF-R family are typical signal sensors which upon binding with ligand aggregate and recruit signal transducers. To date, no TNF-R molecules have been reported in MS although TNF-RI and RII have been localized to oligodendrocytes in culture. In the present study, the expression of TNF, LT alpha (the soluble form of LT), LT beta (the beta chain of LT alpha beta, the membrane-bound form of LT), TNF-RI, TNF-RII, LT beta-R, FasL, and Fas receptor in MS lesions has been examined by immunohistochemistry for protein and by RT-PCR for mRNA. In addition, the TUNEL technique for DNA fragmentation was applied to detect apoptosis. The results have shown that contrarily to predictions, oligodendrocytes around active MS lesions frequently expressed TNF-R molecules belonging to the apoptotic cascade. However, these cells did not undergo apoptosis, as judged by TUNEL. On the other hand, lymphocytes (and a few microglial cells) in the same tissue displayed apoptosis. Microglial cells were the major effector cells in the CNS and expressed TNF, LT alpha and FasL. LT beta expression was seen on astrocytes and oligodendrocytes, and LT beta-R on astrocytes. We conclude that TNF-L and TNF-R molecules are extensively expressed in MS, that their expression occurs at high levels but is not specific for MS, and that oligodendrocytes are depleted by a cytolytic mechanism, not by apoptosis.

[Radical radiotherapy in T2N0 glottic laryngeal carcinomas]. / La radioterapia radicale nei carcinomi laringei glottici T2N0.

The present work analyzes the clinical results obtained at the Istituto del Radio in Brescia, Italy, using radiotherapy in the treatment of T2N0 glottic carcinomas. The analysis covers a sampling of 127 patients who had been treated using fixed field with 60Co or linear accelerator (high energy photons) technique delivering a minimum target dose of 60 Gy over the course of a 6-week period; 200 cGy a day. The purpose of the present study was to evaluate: treatment response 3 months after treatment was suspended using the WHO nomenclature; Overall Survival Rate and Actuarial Disease-Free Survival Rate at five and ten years from the end of treatment comparing the results obtained in cases of T2a and T2b; biological cost of treatment in terms of late recurrences. Three months after treatment had ended, a complete response was seen in 95% of the patients. The overall survival was 85% at five years while the NED survival was 67% at five years. Surgical salvage made it possible to treat 44% of those who did not respond to radiotherapy or who had a recurrence. Late recurrence rate was 4.7%. The clinical results are slightly lower than those obtained in the literature for surgical series in terms of survival probability. They were, however, certainly better in terms of good vocal preservation.

[Radiotherapy of locally advanced tumors of the mouth floor and the tongue]. / La radioterapia dei tumori localmente avanzati del pavimento orale e della lingua.

At Istituto Radio "O. Alberti" in Brescia 312 patients with locally advanced cancers (T3-4N0 and T1-4N1-3) of the tongue or floor of the mouth were treated between 1970 and 1985. All underwent high energy radiotherapy associated, in 93 cases, with surgery on the T and/or on the N. The cases were divided by T and N in order to evaluate the prognostic importance of these parameters. Total remission (TR) at the end of treatment was achieved in 52% of the cases (163 patients). A relationship was found between tumor size, degree of lymph node involvement and the likelihood of response. Of the 163 cases in TR, 89 (55%) showed recurrence; 80% taking place within the first two years. After correction for natural death, the actuarial 5 year survival rate for the entire case study proved to be 27% while NED was 22%. The group undergoing radiotherapy in association with surgery showed a better survival rate than the group which only underwent radiotherapy (45% vs. 20% at 5 years). In the cases of advanced T (T3-4) lymph node involvement did not appear to affect prognosis.