Immune dysregulation and autoreactivity correlate with disease severity in SARS-CoV-2-associated multisystem inflammatory syndrome in children

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Permanent brain ischemia induces marked increments in hsp72 expression and local protein synthesis in synapses of the ischemic hemisphere

Transient focal ischemia induced in rat brain by occlusion of the middle cerebral artery (MCAo) elicits a generalized induction of the 72 kDa heat-shock protein (hsp72) heralding functional recovery. As this effect implies activation of protein synthesis, and local systems of protein synthesis are present in brain synapses, and may be analyzed in preparations of brain synaptosomes, we evaluated hsp72 expression and protein synthesis in synaptosomal fractions of spontaneously hypertensive rats (SHRs) subjected to permanent MCAo. SHRs were randomly divided in ischemics and sham controls, anaesthesia controls and passive controls. Focal ischemia was induced under chloral hydrate anaesthesia by unilateral permanent MCAo. Protein synthesis was determined by [³⁵S]methionine incorporation into synaptosomal proteins from ischemic and contralateral cortex/striatum, and from cerebellum. Hsp72 expression was measured in the same fractions by immunoblotting. Our data demonstrate that under these conditions synaptic hsp72 markedly increases in the ischemic hemisphere 1 and 2 days after MCAo, progressively declining in the following 2 days, while no significant change occurs in control rats. In addition, in the ischemic hemisphere the rate of synaptic protein synthesis increases more than two-fold between 1 and 4 days after MCAo, without showing signs of an impending decline. The present data provide the first demonstration that synaptic protein synthesis is massively involved in brain plastic events elicited by permanent focal ischemia.     

Staurosporine-induced apoptosis in Chang liver cells is associated with down-regulation of Bcl-2 and Bcl-XL

A potent inhibitor of serine/threonine kinases, staurosporine exerts antiproliferative and apoptotic effects in many cancer cells, although the exact mechanism of its action is still unclear. This study examines the effects of staurosporine on Chang liver cells, an immortalized non-tumor cell line, in comparison with those caused in HuH-6 and HepG2 cells, two human hepatoma cell lines. Our results provide evidence that staurosporine promotes apoptosis in Chang liver cells as observed by flow cytometric analysis and acridine orange/ethidium bromide staining. The effect appeared already after 8 h of treatment and increased with treatment time and dose. After 48 h of exposure to 200 nM staurosporine clear apoptotic signs were observed in about 50% of the cells. Western blotting analysis showed that in Chang liver cells staurosporine induced a marked decrease in the levels of the antiapoptotic factors Bcl-2 (-75%) and Bcl-XL (-50%). Staurosporine also caused loss of mitochondrial transmembrane potential, release of cytochrome c from mitochondria and activation of caspase-3. The involvement of caspases in staurosporine-induced cell death was also suggested by the observation that the addition of z-VAD-fmk, a general inhibitor of caspases, suppressed apoptosis. In HuH-6 and HepG2 cells treatment with staurosporine induced the arrest of cells in G2/M phase of cell cycle. This effect was not modified by z-VAD-fmk and was not accompanied by the appearance of biochemical signs of apoptosis. We conclude that staurosporine induced apoptosis in Chang liver cells by a mitochondria-caspase-dependent pathway which was closely correlated with a decrease in Bcl-2 and Bcl-XL levels, while in HuH-6 and HepG2 hepatoma cells the drug caused only an antiproliferative effect.     

Mapping of MRX81 in Xp11.2-Xq12 suggests the presence of a new gene involved in nonspecific X-linked mental retardation

X-linked nonspecific mental retardation (MRX) accounts for approximately 25% of mental retardation in males. A number of MRX loci have been mapped on the X chromosome, reflecting the complexity of gene action in central nervous system (CNS) specification and function. Eleven MRX genes have been identified, but many other causative loci remain to be refined to the single gene level. In 21 MRX families, the causative gene is located in the pericentromeric region; and we report here the identification by linkage analysis of a further such locus, MRX81. The new MRX locus was identified by two- and multi-point parametric analysis carried out on a large Italian family. Tight linkage of MRX81 to DNA markers ALAS2, DXS991, and DXS7132 was observed with a maximum LOD score of 3.43. Haplotype construction delineates an MRX81 critical region of 8 cM, the smallest MRX pericentromeric interval so far described, between DXS1039 and DXS1216, and placing it in Xp11.2-Xq12. So far, automated sequencing of two candidates in the region, the MRX gene oligophrenin (OPHN1) and the brain-specific ephrinB1 (EFNB1) gene, in DNA from affected males excluded their candidacy for MRX81, suggesting a novel disease gene.     

Improved overall survival in dendritic cell vaccination-induced immunoreactive subgroup of advanced melanoma patients

Background  

We present our experience of therapeutic vaccination using dendritic cells (DC) pulsed with autologous tumor antigens in patients with advanced melanoma.     

K-ras gene mutational analysis supports a monoclonal origin of biphasic pleomorphic carcinoma of the lung.

We investigated 27 pleomorphic carcinomas of the lung for exon 1 K-ras gene mutations using polymerase chain reaction-single-strand conformation polymophism analysis and direct sequencing. All pleomorphic carcinomas were biphasic, that is, composed of an adeno-, squamous- or large-cell-carcinomatous component associated with a spindle- and/or giant-cell component. Of 27 cases, six (22%) showed K-ras codon 12 mutations, which is a figure higher than that previously reported on in pure sarcoma-like pleomorphic carcinomas. Five tumors displayed the same mutation in both the epithelial and the sarcomatoid components, whereas in one tumor the mutation was restricted to the epithelial component. All mutations occurred in smokers, and were transversions, including GGT (glycine) to TGT (cysteine) change in two cases, to GCT (alanine) in two and to GTT (valine) in two. No significant relationships were found between the occurrence and type of mutations and patients' survival or any other clinicopathological variable, suggesting that K-ras mutations are early events in the development of these tumors. Our results indicate that most, though not all, biphasic pleomorphic carcinomas of the lung are monoclonal in origin, and that cigarette smoking may have a causative role in the development of K-ras alterations in these tumors, as all mutations are transversions.     

What and where in human audition: selective deficits following focal hemispheric lesions

A sound that we hear in a natural setting allows us to identify the sound source and localize it in space. The two aspects can be disrupted independently as shown in a study of 15 patients with focal right-hemispheric lesions. Four patients were normal in sound recognition but severely impaired in sound localization, whereas three other patients had difficulties in recognizing sounds but localized them well. The lesions involved the inferior parietal and frontal cortices, and the superior temporal gyrus in patients with selective sound localization deficit; and the temporal pole and anterior part of the fusiform, inferior and middle temporal gyri in patients with selective recognition deficit. These results suggest separate cortical processing pathways for auditory recognition and localization. Electronic Publication     

Modulation of the constitutive or cytokine-induced bronchial epithelial cell functions in vitro by fluticasone propionate

When exposed to proinflammatory mediators, human bronchial epithelial cells (HBECs) upregulate the 'constitutive' adhesion molecule expression and cytokine/chemokine release. We tested whether and to what extent the inhibitory effect of fluticasone propionate on HBECs could involve the 'constitutive' and 'cytokine-induced' proinflammatory functions. Stimulation of the HBECs with interleukin (IL)-4 plus tumour necrosis factor (TNF)-alpha was more effective in upregulating intercellular adhesion molecule (ICAM)-1 ( approximately 2.2-fold increase) than vascular adhesion molecule (VCAM)-1 ( approximately 1.6-fold increase) expression (P<0.05) and in increasing the release of 'regulated on activation normal T cell expressed' (RANTES, 5.7-fold increase) than of IL-8 (3.5-fold increase) and granulocyte macrophage-colony stimulating factor (GM-CSF, 2.8-fold increase), (P<0.01). Fluticasone propionate, at the two concentrations tested (10 and 100 nM), was more effective in inhibiting the 'IL-4 plus TNF-alpha-induced' ICAM-1 expression than VCAM-1 expression (P<0.05) and in downregulating RANTES than IL-8 or GM-CSF secretion (P<0.05). The degree of inhibition demonstrated by fluticasone propionate appeared to be related to the degree of cell activation. In addition, for both adhesion molecules, the effect of fluticasone propionate at both concentrations tested appeared to be related to a complete inhibition of 'IL-4 plus TNF-alpha-induced' expression with no involvement of the 'constitutive' expression. Slightly different results were observed for cytokine/chemokine release. Indeed, evaluating RANTES, a complete inhibition of the 'IL-4 plus TNF-alpha-induced' release with a partial inhibition also of the 'constitutive' release at both concentrations of the drug tested was found, whereas for GM-CSF and IL-8, only a partial inhibition of the 'IL-4 plus TNF-alpha-induced' release in the presence of fluticasone propionate 10 and 100 nM. Thus, HBECs can constitutively or upon activation express adhesion molecules and secrete proinflammatory proteins at various levels and the different ability of fluticasone propionate to modulate the HBEC functions appears to be mostly related to the different inhibition of the various 'IL-4 plus TNF-alpha-induced' responses.