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Weak Reactivity (weak + reactivity)
Selected AbstractsOverexpression of Fos-related antigen-1 in head and neck squamous cell carcinomaINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2005Flavia R. R. Mangone Summary The activating protein-1 (AP-1) family of transcription factors has been implicated in the control of proliferation and differentiation of keratinocytes, but its role in malignant transformation is not clear. The aim of this study is to assess the pattern of mRNA expression of jun-fos AP-1 family members in 45 samples of head and neck squamous cell carcinomas (HNSCC) and matched adjacent mucosa by means of Northern blot analysis. Transcripts of all family members were identified, except for JunB that was detected only by means of reverse transcription polymerase chain reaction. Neither c-Fos nor JunD or FosB mRNA differed between tumours and normal tissues. We observed a strong Fos-related antigen-1 (Fra-1) and Fra-2 expression, but only Fra-1 mRNA densitometric values were higher in tumour, compared to normal adjacent mucosa (t -test, P = 0.006). A direct relationship between the positive expression of Fra-1 mRNA, above tumour median, was associated with the presence of compromised lymph nodes (Fischer exact test, P = 0.006). In addition, Fra-1 protein staining was assessed in a collection of 180 tumours and 29 histologically normal samples adjacent to tumours in a tissue array. Weak reactivity, restricted to the basal cell layer, was detected in 79% of tumour adjacent normal tissues, opposed to the intense reactivity of cancer tissues. In the subgroup of oral cancers, we have observed a shift in Fra-1 immunoreactivity, as long as the number of patients in each category, cytoplasmic or nuclear/cytoplasmic staining, was analysed (Fischer exact test, P = 0.0005). Thus, Fra-1 gene induction and accumulation of Fra-1 protein may contribute to the neoplastic phenotype in HNSCC. [source] Dietary pectin up-regulates monocaboxylate transporter 1 in the rat gastrointestinal tractEXPERIMENTAL PHYSIOLOGY, Issue 4 2009Doaa Kirat This work was undertaken to study the effect of pectin feeding on the expression level, cellular localization and functional activity of monocarboxylate transporter 1 (MCT1) in the gastrointestinal tract of rats. The results indicated that MCT1 protein level was significantly increased along the entire length of the gastrointestinal tract of pectin-fed rats in comparison with control animals. Immunohistochemical analysis revealed an increase in MCT1 in the stratified squamous epithelia of the forestomach as well as in the basolateral membranes of the cells lining the gastric pit of the glandular stomach of pectin-fed rats when compared with control animals. The parietal cells, which showed barely any or no detectable MCT1 in the control group, exhibited a strong intensity of MCT1 on the basolateral membranes in pectin-fed rats. In the small intestine of pectin-fed rats, strong immunopositivity for MCT1 was detected in the brush border and basolateral membranes of the absorptive enterocytes lining the entire villi, while in control rats, weak reactivity was detected on the brush border membrane in a few absorptive enterocytes in the villus tip. In the large intestine of control animals, MCT1 was detected on the basolateral membranes of the epithelia lining the caecum and colon. This staining intensity was markedly increased in pectin-fed rats, along with the appearance of strong reactivity for MCT1 on the apical membranes of the surface and crypt epithelia of caecum and colon. Our results also showed that MCT1 co-localizes with its chaperone, basigin (CD147), in the rat gastrointestinal tract, and that the pectin feeding increased the expression of CD147. In vivo functional studies revealed an enhanced acetate absorption in the colon of pectin-fed in comparison with control animals. We conclude that MCT1 is up-regulated along the gastrointestinal tract of pectin-fed rats, which might represent an adaptive response to the increased availability of its substrates. [source] Study of in vitro glucuronidation of hydroxyquinolines with bovine liver microsomesFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2002Masanobu Kanou Abstract Glucuronidation of drugs by UDP-glucuronosyltransferase (UGT) is a major phase II conjugation reaction. Defects in UGT are associated with Crigler,Najjar syndrome and Gilbert's syndrome with severe hyperbilirubinaemias and jaundice. We analysed the reactivities of some hydroxyquinoline derivatives, which are naturally produced from quinoline by cytochrome P450. The analyses were carried out using a microassay system for UGT activity in bovine liver microsomes in the range 0.5,100 pmol/assay with the highly sensitive radio-image analyser Fuji BAS2500 (Fujifilm, Tokyo, Japan). 3-Hydroxylquinoline is a good substrate for glucuronidation, and the relative Kcat values were 3.1-fold higher than the values for p-nitrophenol. 5,6-Dihydroquinoline-5,6- trans -diol gave a similar Km value to that of 3-hydroxyquinoline, but the Vmax value was approximately 1/15 of that of p-nitrophenol and showed weak reactivity. Quinoline N-oxide gave a low Vmax value and showed marginal activity. The Kcat values of 6-hydroxyquinoline and 5-hydroxyquinoline were 2.1- and 1.2-fold higher than that of p-nitrophenol, respectively. Fluoroquinoline (FQ) derivatives, such as 3FQ, 7,8diFQ and 6,7,8triFQ, did not show any substrate activities. These results suggest that there are therapeutic problems in administration of some quinoline drugs to patients with jaundice. [source] Electron microscopic detection of statherin in secretory granules of human major salivary glandsJOURNAL OF ANATOMY, Issue 5 2008M. Isola Abstract In order to increase current knowledge regarding statherin secretion into the oral cavity, ultrastructural localization of this peptide was investigated in human salivary glands by using a post-embedding immunogold staining technique. Statherin reactivity was found inside the granules of serous cells of parotid and submandibular glands. In parotid granules immunostaining was preferentially present in the less electron-dense region, whereas in submandibular serous granules the reactivity was uniform and the dense core always stained. By contrast, none or weak reactivity was observed in serous cells of major sublingual glands. These findings reveal for the first time the subcellular localization of statherin by electron transmission microscopy and confirm that of the three major types of salivary glands, the parotid and submandibular glands are the greatest source of salivary statherin. Moreover, they suggest that more than one packaging mechanism may be involved in the storage of statherin within serous granules of salivary glands. [source] Young age a predictor of weak reactivity in a rapid antibody test in infants infected with HIVJOURNAL OF MEDICAL VIROLOGY, Issue 8 2010Leana Maree Abstract In a resource-constrained African setting, children suspected of being infected with HIV are often screened with rapid antibody tests prior to definitive diagnosis with viral genome detection. It has previously been shown that a rapid antibody assay such as the CapillusÔ HIV-1/HIV-2 test may have a high false-negative rate in infants. In this study CD count and percentage, HIV-1 viral load, antigen-specific reactivity, and age was explored as predictors of negative or low antibody reactivity by this assay. Young age was found to be the only factor associated significantly with low antibody reactivity. This phenomenon appeared to be specific to HIV since no such age association was found for antibody reactivity to tetanus toxoid. Rapid assays only validated in adults should therefore be used with utmost caution in young infants since this may lead to high rates of false-negative results. J. Med. Virol. 82:1314,1317, 2010. © 2010 Wiley-Liss, Inc. [source] Fimbriae of Porphyromonas gingivalis induce opsonic antibodies that significantly enhance phagocytosis and killing by human polymorphonuclear leukocytesMOLECULAR ORAL MICROBIOLOGY, Issue 3 2001Q. Fan Porphyromonas gingivalis has been strongly implicated in the pathogenesis of human periodontitis. Fimbriae mediate adherence and colonization of the oral cavity by this organism and may, therefore, have potential for use as antigen in an anti,P. gingivalis vaccine. The purpose of our study was to determine whether P. gingivalis fimbriae have opsonic target sites and whether they are accessible on the cell surfaces and cross-reactive among P. gingivalis fimbrial types and serotypes. Rabbits were immunized with a vaccine. The antiserum reacted with a 43-kDa fimbrillin monomer and a 43-kDa component in whole-cell sonicates of P. gingivalis 33277, but it showed only very weak reactivity in the 43-kDa region of Western blots of a whole-cell sonicate of strain DPG3, a mutant that does not express functional fimbriae. The antibody enhanced chemiluminescence approximately six-fold relative to preimmune serum values and significantly enhanced phagocytosis and killing of P. gingivalis 33277 by human polymorphonuclear leukocytes. Peak opsonic activity was observed at week 6 followed by a plateau that remained until week 16. The fimbria-deficient mutant DPG3 did not bind antifimbrial antibody and was not opsonized, whereas strain 381, the parent of the mutant, was opsonized. The specific antibody bound to and opsonized P. gingivalis strains 33277 and 381 (fimbria type I) but not W50, A7A-1-28, 9-14K-1 or FAY-19M-1 (fimbrial types II,V). Specific antibody bound to strain 2561 (fimbrial type I) but, as assessed by chemiluminescence, did not opsonize it. While fimbriae have opsonic target sites that are accessible on P. gingivalis cell surfaces, the relevant opsonic target sites do not appear to be shared across serotypes or fimbrial types. Thus, a vaccine containing, as antigen, fimbrial protein from a single P. gingivalis strain would likely be ineffective against infections by P. gingivalis strains expressing other fimbrial types. [source] | |||||||||||||