Incidence of latent infection of Epstein–Barr virus in lung cancers—an analysis of EBER1 expression in lung cancers by in situ hybridization

To evaluate the presence of Epstein–Barr virus (EBV) in lung cancers of Japanese patients, 81 lung cancers were examined using a highly sensitive in situ hybridization (ISH) method, employing an antisense oligonucleotide probe for EBV-encoded small nuclear RNA-1 (EBER). EBER1 expression was demonstrated in one poorly differentiated squamous cell carcinoma associated with marked lymphoid stroma (PDSCC-LS), two well differentiated adenocarcinomas, and two moderately differentiated squamous cell carcinomas, but was not detectable in other lung cancers, including small cell carcinomas. Unlike lymphoepithelioma-like undifferentiated carcinoma (LELC) of the lung, the PDSCC-LS consisted of poorly differentiated cells with distinct cell borders and nuclei with a coarse chromatin pattern and some prominent nucleoli. Most of the cancer cells expressed intense EBER1 signals. Although small to moderate numbers of cells positive for EBER1 were present in two adenocarcinomas and two squamous cell carcinomas, EBER1 signals varied in intensity and number in these four cases. Although polymerase chain reaction (PCR) and Southern blot hybridization with a ³²P-labelled probe internal to the primers were conducted to detect the EBV genome in 24 lung cancers, including five EBER1-positive cases, the genome was found to be positive in the five cases with EBER1-positive staining, including the PDSCC-LS, two adenocarcinomas and two squamous cell carcinomas, but not in the other cases. This study indicates that the morphological features of EBV-associated lung cancers are not restricted to the typical LELC type.     

Fc receptor-mediated accumulation of macrophages in crescentic glomerulonephritis induced by anti-glomerular basement membrane antibody administration in WKY rats

Anti-glomerular basement membrane (GBM) glomerulonephritis induced in WKY rats is characterized by glomerular accumulation of CD8(+) T cells and monocytes/macrophages, followed by crescent formation. The mechanism of leukocyte accumulation after antibody binding to GBM is still unclear. To unveil an involvement of Fcgamma receptors (FcgammaR) in leukocytes recruitment we examined the expression of FcgammaR in glomeruli and the effects of the administration of F(ab')(2) fragment of anti-GBM antibody or FcgammaR blocking on the initiation and progression of this model. A gradual increase of FcgammaR mRNA expression in glomeruli during the time course of disease suggested their significance in the development of glomerulonephritis. Glomerular lesions and proteinuria were induced only in rats injected with intact IgG of anti-GBM antibody, but not with the F(ab')(2) fragment. In vivo blocking of FcgammaR by administering heat-aggregated IgG led to the decrease of mRNA expression for all types of FcgammaR (types 1, 2 and 3) and a significant amelioration of glomerulonephritis manifestations. By flow cytometry and immunohistochemistry FcgammaR2-expressing cells in glomeruli were identified as macrophages, but not CD8(+) T cells. The expression of FcgammaR1 and 3 was significantly decreased, and that of FcgammaR2 became undetectable in CD8(+) T cell-depleted rats. Thus, CD8(+) T cells may stimulate FcgammaR expression on macrophages, contributing to their glomerular accumulation and injury. These studies provide direct evidence for a crucial involvement of IgG Fc-FcgammaR interaction in glomerular recruitment of macrophages and following induction of anti-GBM glomerulonephritis in WKY rats.     

Flavonoids such as luteolin, fisetin and apigenin are inhibitors of interleukin-4 and interleukin-13 production by activated human basophils

BACKGROUND: We have previously shown that fisetin, a flavonol, inhibits IL-4 and IL-13 synthesis by allergen- or anti-IgE-antibody-stimulated basophils. This time, we investigated the inhibition of IL-4 and IL-13 production by basophils by other flavonoids and attempted to determine the fundamental structure of flavonoids related to inhibition. We additionally investigated whether flavonoids suppress leukotriene C4 synthesis by basophils and IL-4 synthesis by T cells in response to anti-CD3 antibody. METHODS: Highly purified peripheral basophils were stimulated for 12 h with anti-IgE antibody alone or anti-IgE antibody plus IL-3 in the presence of various concentrations of 18 different kinds of flavones and flavonols. IL-4 and IL-13 concentrations in the supernatants were then measured. Leukotriene C4 synthesis was also measured after basophils were stimulated for 1 h in the presence of flavonoids. Regarding the inhibitory activity of flavonoids on IL-4 synthesis by T cells, peripheral blood mononuclear cells were cultured with flavonoids in anti-CD3-antibody-bound plates for 2 days. RESULTS: Luteolin, fisetin and apigenin were found to be the strongest inhibitors of both IL-4 and IL-13 production by basophils but did not affect leukotriene C4 synthesis. At higher concentrations, these flavonoids suppressed IL-4 production by T cells. Based on a hierarchy of inhibitory activity, the basic structure for IL-4 inhibition by basophils was determined. CONCLUSIONS: Due to the inhibitory activity of flavonoids on IL-4 and IL-13 synthesis, it can be expected that the intake of flavonoids, depending on the quantity and quality, may ameliorate allergic symptoms or prevent the onset of allergic diseases.     

PHI+], a novel Sup35-prion variant propagated with non-Gln/Asn oligopeptide repeats in the absence of the chaperone protein Hsp104

BACKGROUND: The [PSI+] element of the budding yeast is an aggregated form of the translation release factor Sup35 that is propagated and transmitted cytoplasmically in a manner analogous to that of mammalian prions. The N-terminal of Sup35, necessary for [PSI+], contains oligopeptide repeats and multiple Gln/Asn residues. RESULTS: We replaced the Gln/Asn-rich prion repeats of Sup35 with non-Gln/Asn repeats from heterologous yeast strains. These non-Gln/Asn repeat Sup35s propagated a novel [PSI+] variant, [PHI+], that appeared de novo 103 times more frequent than [PSI+]. [PHI+] was stably inherited in a non-Mendelian fashion, but not eliminated upon the inactivation of Hsp104, unlike known [PSI+] elements. In vitro, non-Gln/Asn repeat domains formed amyloid fibres that were shorter and grew more slowly than did Gln/Asn-rich prion domains, while [PHI+] aggregates were smaller than [PSI+] aggregates in vivo. CONCLUSIONS: These findings suggest the existence of an alternative, Hsp104-independent pathway to replicate non-Gln/Asn variant Sup35 prion seeds.     

Hormone production andc-myc protein labeling in plurihormonal pituitary adenomas

The biological activity of plurihormonal pituitary adenomas was compared with that of tumors producing only one hormone by evaluating the percentage ofc- myc protein-labeled cells and ultrastructural characteristics. Twenty-five pituitary adenomas producing 3 or more hormones and 14 adenomas producing only I hormone were studied. Tissue sections were stained immunohistochemically using antibodies for pituitary hormones andc- myc protein, and they were examined by electronmicroscopy. DNA extracted from ethanol-fixed, paraffinembedded tissue was analyzed for p53 mutations by polymerase chain reaction and singlestrand conformation polymorphism analysis. The percentage ofc- myc protein-labeled cells in adenomas producing 4 or 5 pituitary hormones was significantly higher (p < 0.01 ) than in those producing 3 or 1 hormones. There were no p53 mutations in plurihormonal adenomas. Pituitary adenomas producing 4 or 5 pituitary hormones demonstrate biological aggressiveness; therefore, multihormone production reflects aggressive capacity rather than degree of differentiation.     

A missense mutation in the proteolipid protein gene responsible for Pelizaeus--Merzbacher disease in a Japanese family

We investigated the proteolipid protein (PLP) gene of two boysin a Japanese family with Pelizaeus—Merzbacher disease(PMD), an X-linked neurologic disorder characterized by dysmyelinationin the central nervous system (CNS). The patients showed similarclinical signs from birth and autopsy on the elder brother confirmeda connatal type of PMD. Direct sequencing of the PLP gene andPLP mRNAs from the brain of the PMD patient revealed a G toT transition in exon V of the PLP gene, which leads to a glycineto cystein substitution at residue 220. Allele-specific oligonucleotidehybridization revealed that this mutation was also present inhis brother, but was absent in 100 X chromosomes of normal Japaneseindividuals. Northern blot analysis showed that the mRNA levelsof PLP and myelin basic protein, two major myelin proteins producedby oligodendrocytes, were much reduced in the PMD brain, hence,there was a specific loss of oligodendrocytes. It seems likelythat the substitution is responsible for PMD (connatal type)in this particular family and causes oligodendrocytes deathin the CNS.     

Tetraethylammonium-insetisitive,Ca2+-activated whole-cell K+ currents in rat submandibular acinar cells

Using whole-cell patch-clamp techniques, we demonstrate, for the first time, that rat submandibular acinar cells contain a tetraethylammonium (TEA)-insensitive, Ca²⁺-activated K⁺ conductance which is not attributable to large conductance, voltage-sensitive, Ca²⁺-dependent K⁺ channels (maxi-K⁺ channels). Taken together with our recent K⁺ efflux and fluid secretion studies in intact rat submandibular gland, we postulate that the K⁺ conductance reported here may be involved in the basolateral K⁺ efflux pathway activated by cytosolic Ca²⁺ concentration during secretion by this gland.     

Effects of cerebral protective agents in experimental cerebral ischemia. Relationship between the degree of ischemia and EEG

We have previously demonstrated that the preischemic administration of perfluorochemicals (PFC) in combination with 20% mannitol, vitamin E and dexamethasone is effective in protecting the brain from cerebral ischemia. This experimental study was designed to evaluate the effect and limitation of the post-ischemic administration of those 4 agents on cerebral ischemia. We used "Canine model of complete ischemic brain regulated with a perfusion method." Using this model we were able to control the amount of blood flow to the left cerebral hemisphere by using an infusion pump. Infusion blood volume was reduced to 30%, 40% or 50% of the normal state, then the combined treatment was started 1,2,3,4,5 or 6 hours after the onset of ischemia in each ischemic group. By monitoring the EEG for 8 hours of ischemic period, we were able to evaluate the effect of the drugs on cerebral ischemia. In untreated groups, electrical activity deteriorated gradually. In the 30% ischemia group, the EEG became isoelectric within 1 hour following ischemia. In half of the 40% ischemia group, the EEG became isoelectric but in the other half low voltage slow wave were seen to last for 6-8 hours. In the 50% group, the EEG deteriorated gradually but did not disappear within 8 hours. The effectiveness of the treatment was judged by the degree of the recovery of electrical activity. The effectiveness of the treatment appeared to depend on the severity and the duration of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)