Non-Polarized Secretion of Mouse Interferon-β from Gene-Transferred Human Intestinal Caco-2 Cells

Purpose. The intestinal epithelium is considered to be a feasible target for somatic gene therapy. To this end, Caco-2 cells derived from human colon carcinoma were transfected with a mouse interferon- (IFN-) expression vector and several stable sublines were established; this hetero-specific cytokine allows unexpected cellular effects to be avoided. Using the highest mouse IFN--producing sublines, the mode of IFN secretion was examined. Methods. The secretion polarity of mouse IFN- in its gene-transduced Caco-2 sublines was studied in a bicameral culture system in which the chambers were separated by microporous filters. Results. Mouse IFN- was secreted to the same extent from both apical and basolateral surfaces of the transduced cells regardless of cell aging. Conclusions. These results suggest that in the intestinal epithelium exogenous gene products such as IFNs can be delivered to both the luminal and blood sides in vivo. Thus, the intestinal epithelium may be suitable for systemic and local delivery of therapeutic proteins by gene transfer.     

Paraganglia of the gallbladder: a report of two cases with an immunohistochemical study

Paraganglionic tissues incidentally observed in the gallbladder are presented. The patients, a 51- and a 55-year-old woman, underwent gallbladder resection for chronic cholecystitis with gallstones. Two and one paraganglionic tissues were observed in the subserosal connective tissue of the two gallbladders, respectively. Immunohistochemically, the chief cells were positive for chromogranin A, and the sustentacular cells were positive for S100 protein. Tyrosine hydroxylase (in two of three), dopamine beta-hydroxylase (in one of three), methionine-enkephalin (in two of three), and leucine-enkephalin (in two of three) were also positive in a small amount of the chief cells. These structures, which slightly resembled adrenal medulla or retroperitoneal paraganglia, might be misunderstood as an infiltration of primary or metastatic carcinoma into the subserosal connective tissue.     

Visual completion of partly occluded grating in infants under 1 month of age

Four groups of eight infants (3 weeks of age on average) were each habituated to one of four displays consisting of a grating of either low (0.4 cpd) or high (1.2 cpd) spatial frequency, whose central portion was covered up with a horizontal occluder which was either narrow (1.33 degrees) or broad (4.17 degrees). These habituation displays are referred to as LN (low spatial frequency grating and narrow occluder), LB (low and broad), HN (high and narrow), and HB (high and broad) displays. Posthabituation-test displays consisted of a complete grating (CG) of the same frequency as the habituated grating along with a separate grating (SG) whose central portion was replaced with a black gap of the same height as the occluder in the habituation displays. Infants habituated to the LN display looked significantly longer at the SG than the CG display during posthabituation-test trials. Infants habituated to the LB and HN displays looked at the CG and SG displays, almost equally. In contrast, infants habituated to the HB display looked longer at the CG than the SG display. These results show that infants under 1 month of age can perceive the continuation of the grating behind the occluder, and that their visual completion on habituation displays can be evoked according to the interaction between the spatial frequency of the grating and the occluder height.     

Proteinase activated receptor 2: Role of extracellular loop 2 for ligand-mediated activation

1. Rat proteinase-activated receptor-2 (PAR2) variants were stably expressed in rat KNRK cells: (a) wild-type (wt) - PAR2; (b) PAR2PRR, with the extracellular loop 2 (EL-2) sequence P231E232E233mutated to PRR and (c) PAR2NET, with the EL-2 sequence, PEEV changed to NETL. Cell lines were evaluated for their sensitivity (calcium signalling) towards trypsin and the receptor-activating peptides, SLIGRL-NH2, SLIGEL-NH2, trans-cinnamoyl(tc)-LIGRLO-NH2, and SFLLR-NH2. 2. SLIGEL-NH2 exhibited low potency (1 : 200 relative to SLIGRL-NH2) in wild-type PAR2. Its activity was increased 5 fold in PAR2PRR, but it was inactive in PAR2NET. 3. In PAR2PRR, the potencies of SLIGRL-NH2, tc-LIGRLO-NH2, and SFLLR-NH2 were decreased by 80 - 100 fold. But, the potency of trypsin was decreased by only 7 fold. 4. In PAR2NET, highly homologous in EL-2 with proteinase-activated receptor-1 (PAR1), the potency of the PAR1-derived peptide, SFLLR-NH2, was reduced by 100 fold compared with wt-PAR2, whereas the potency of the PAR2-derived AP, SLIGRL-NH2 was reduced 10 fold. In contrast, the potency of trypsin in PAR2NET was almost the same as in wt-PAR2. 5. We conclude that the acidic EL-2 tripeptide, PEE, in PAR2 plays an important role in governing agonist activity. 6. The data obtained with the PEEV-->NETL mutation suggested: (a) that SLIGRL-NH2 and SFLLR-NH2 interact in a distinct manner with PAR2 and (b) that SFLLR-NH2 may interact differently with PAR2 than it does with PAR1. 7 The differential reductions in the potencies of SLIGRL-NH2, compared with trypsin in the PAR2PRR and PAR2NET cell lines point to differences between the interactions of the trypsin-revealed tethered ligand and the free receptor-activating peptide with PAR2.     

Involvement of cysteinyl leukotrienes in biphasic increase of nasal airway resistance of antigen-induced rhinitis in guinea pigs

We examined the effect of a specific cysteinyl leukotriene (LT) receptor antagonist, 4-oxo-8-[4-(4-phenylbutoxy)benzoylamino]-2-(tetrazol-5-yl)-4 H-1-benzopyran hemihydrate (pranlukast), on a novel model of allergic rhinitis induced by repeated intranasal ovalbumin challenge in actively sensitized guinea pigs. Repeated intranasal ovalbumin challenge caused a biphasic increase of nasal airway resistance, peaking 0.5 and 4 h after the final challenge. The early-phase response was accompanied by an increase in sneezing and nasal secretion, while that in the late phase was associated with edema and eosinophil infiltration of the nasal mucosa. Analysis of nasal lavage fluid showed that cysteinyl LTs increased in both phases. Pranlukast, when administered 1 h before every ovalbumin challenge, dose-dependently suppressed the increase of nasal airway resistance in the early- and late phase with evidence of histopathological improvements in the late phase. Pranlukast, however, failed to suppress sneezing and nasal secretion. We suggest that cysteinyl LTs play an important role in allergic rhinitis especially in the nasal obstruction due to edema of the nasal mucosa membrane.     

In vitro antibacterial activity of FK041, a new orally active cephalosporin.

The in vitro activity of FK041, a new orally active cephem antibiotic, against a wide variety of clinical isolates of bacteria was investigated and compared with those of cefdinir (CFDN) and cefditoren (CDTR). FK041 exhibited broad spectrum activity against reference strains of Gram-positive and Gram-negative aerobes and anaerobes. FK041 was active against clinical isolates of Gram-positive organisms except Enterococcus faecalis with MIC90s less than 1.56 microg/ml. FK041 was more active than CFDN and CDTR against Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae and was comparable to CFDN and CDTR against Streptococcus pyogenes and Streptococcus pneumoniae. FK041 had no activity against methicillin-resistant staphylococci, like CFDN and CDTR. FK041 showed moderate activity against penicillin-resistant S. pneumoniae with an MIC range of 0.05 approximately 3.13 microg/ml, and was superior to CFDN but inferior to CDTR. Against clinical isolates of many Gram-negative organisms such as Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, FK041 had good activity comparable or superior to those of CFDN and CDTR. However, it was inferior to CDTR in activity against Moraxella catarrhalis, Haemophilus influenzae, Morganella morganii, and Serratia marcescens, and was inactive against Pseudomonas aeruginosa. With FK041 a small difference between MIC and MBC against S. aureus, E. coli, K. pneumoniae, and H. influenzae was found, indicating that its action is bactericidal against these species. FK041 was stable to group 2beta-lactamase hydrolysis but was unstable to group 1beta-lactamase hydrolysis. The stability of FK041 to these enzymes was similar to those of CFDN and CDTR. FK041 showed high affinity for the main penicillin-binding proteins (PBPs) of S. aureus (PBP 3, 2, and 1) and E. coli (PBP 3, 4, lbs, 2, and 1a).     

Citrus auraptene inhibits chemically induced colonic aberrant crypt foci in male F344 rats

The modifying effect of dietary administration of auraptene isolated from the peel of citrus fruit (Citrus natsudaidai Hayata) on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) was investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body wt) once a week for 3 weeks to induce ACF. They also received diets containing 100 or 500 p.p.m. auraptene for 5 weeks, starting 1 week before the first dose of AOM. At termination of the study (week 5) dietary administration of auraptene caused a significant reduction in the frequency of ACF in a dose- dependent manner (P < 0.05). Feeding of auraptene suppressed expression of cell proliferation biomarkers (5-bromo-2'-deoxyuridine labeling- index, ornithine decarboxylase activity, polyamine content and number of silver stained nucleolar organizer region protein particles) in the colonic mucosa and the occurrence of micronuclei caused by AOM. Also, auraptene increased the activities of phase II enzymes (glutathione S- transferase and quinone reductase) in the liver and colon. These findings might suggest that inhibition of AOM-induced ACF may be associated, in part, with increased activity of phase II enzymes in the liver and colon and suppression of cell proliferation in the colonic mucosa.      

Genotoxicity studies of glycidol fatty acid ester (glycidol linoleate) and glycidol

Glycidol fatty acid esters (GEs) are found in refined edible oils. Safety concerns have been alleged due to the possible release of glycidol (G), an animal carcinogen.