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.     

Decrease of Interleukin-2 secretion is a new independent prognostic factor associated with poor survival in patients with small-cell lung cancer

Background: We have previously shown that suppression of Interleukin-2(IL-2) secretion was mediated by transforming growth factor (TGF) 1secreted by small-cell lung cancer (SCLC) tumor cells. We have also shown thatIL-2 secretion was significantly impaired in patients with SCLC at the timeof diagnosis. Reconstitution of cytokine secretion correlated with reductionof tumor load. These data suggested that the immune system was suppressed bythe tumor. To address the clinical relevance of cytokine suppression in SCLC,we investigated the correlation of the level of IL-2 secretion with survival.Patients and methods: The significance of correlations between singleparameters in the test groups was calculated by using the linear regressionanalysis, the Wilcoxon rank sum test and the exact test according to Fisher.Using the Kaplan–Meier method, the log-rank test and the Cox-regressionmodel, we analysed the relation of IL-2 secretion in whole blood cell culturesfrom 52 patients with SCLC at the time of diagnosis to established prognosticfactors relevant for survival in SCLC.Results: Impairment of IL-2 secretion significantly correlates to survivalin SCLC (P = 0.004). Further univariate and multivariate analysis showed thatthis prognostic factor is independent from other factors of prognosticrelevance in SCLC, namely stage of disease, neurone specific enolase (NSE),lactate dehydrogenase (LDH), age, and sex. More important, the prognosticvalue of IL-2 secretion is comparable to the most predominant prognosticfactors for survival in SCLC identified so far. In the final model of the coxregression analysis, the P-value for IL-2 secretion in relation to stage ofdisease was 0.012 and 0.019, respectively.Conclusions: IL-2 secretion at the time of diagnosis represents anindependent prognostic factor for survival in SCLC. Although its prognosticvalue has to be confirmed in a larger group of patients, our resultsdemonstrate that IL-2 secretion may play an important role in diagnosis andtreatment of SCLC. Moreover, in contrast to other prognostic factors,impairment of IL-2 secretion may help to understand immunosuppression in SCLCand, thus, important elements of the pathogenesis of this disease.     

Role of T lymphocytes in secretory response to an enteric nematode parasite

Athymic (nude) rats have been used to assess the role of thymus-dependent T cells in the control of the intestinal response following infection with the enteric parasite,Nippostrongylus brasiliensis. Tissues from infected rats were excised on days 4, 7, 10, and 21 postinfection (p-i) for physiological and morphological studies; uninfected (day 0) rats served as controls. In response to the worm burden, jejunal tissues displayed a secretory response, indicated by an elevated baseline short-circuit current (I _sc ) on days 7 and 10 p-i, and were more responsive to histamine than control tissues. Despite this enhanced secretory response, 35% of the worm burden was still present on day 21 p-i (compared with expulsion of >95% by day 14 p-i in normal rats). Mast cell activation and hyperplasia, increased goblet cell (implying increased mucus synthesis) and intraepithelial leukocyte numbers, and abnormalities inI _sc responses after electrical stimulation of enteric nerves were identified following infection. These events in nude rats were attenuated or delayed in onset as compared with conventional immunocompetent rats. Our results support the postulate that thymus-dependent T cells regulate the timing and/or nature of the mucosal response to enteric parasitic infections. However, ion secretion was not altered in the absence of T cells and, therefore, is more likely to be a consequence of mast cell activation.This work was conducted with financial support from The Canadian Medical Research Council and the National Institutes of Health (NS 29536).     

Effect of platelet-activating factor on secretion of mucous glycoprotein from chinchilla middle ear epithelial cells in vitro

Platelet-activating factor (PAF) is a naturally occurring phospholipid that acts as a pleiotropic mediator and mediates cell-cell reactions under physiological and pathological conditions. Recently, it has been shown that PAF is a strong secretagogue of mucous glycoprotein in the airways, suggesting its role in mucous glycoprotein secretion and the pathogenesis of otitis media with effusion. In the current study, we examined the effect of PAF on mucous glycoprotein secretion in cultured chinchilla middle ear epithelial cells. PAF at 1 M significantly stimulated mucous glycoprotein secretion from cultured chinchilla middle ear epithelial cells. This action was concentration-dependent, with secretions reaching near maximum when the cells were incubated with PAF at 100 M. In a time-dependent study, PAF demonstrated an initial rapid stimulation of mucous glycoprotein secretion, followed by a gradual increase thereafter. A six-fold increase was seen in the first 2 h compared with controls. Cycloheximide, a protein synthesis inhibitor, demonstrated an inhibitory effect on PAF-stimulated mucous glycoprotein secretion in this study. These findings suggest that PAF plays an important role in the pathogenesis of otitis media with effusion by stimulating mucous glycoprotein secretion in vitro.Supported by NIH grant P0I-D000133 from the National Institute on Deafness and Other Communication Disorders.     

Eicosanoid-mediated Cl− secretion induced by the antitumor drug,irinotecan (CPT-11), in the rat colon

Irinotecan (CPT-11) is active against a broad range of human cancer. One of the side-effects of irinotecan is a strong diarrhoea. In order to investigate the mechanism underlying this diarrhoea, the effect of irinotecan on anion secretion across the isolated rat distal colon was studied. Irinotecan caused a concentration-dependent increase in short-circuit current (Isc). The increase in Isc was completely dependent on the presence of Cl^– ions and was supressed by furosemide and the Cl^– channel blocker NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate), indicating that it is caused by a Cl^– secretion. The secretory response was inhibited by indomethacin, 1-benzylimidazole, a thromboxane synthase inhibitor, and SK&F 88046 ((N,Nbis-[7-(3-Chlorobenzeneaminosulfonyl)-1,2,3,4-tetrahydroisoquinolyl)disulfonylimide), a thromboxane A₂ receptor blocker. In isolated crypts irinotecan had no effect on the membrane potential. Consequently, the secretion induced by irinotecan is an indirect one, caused by the stimulation of eicosanoid production, e.g. thromboxane A₂, in the subepithelial tissue.     

Ultrastructural neuropathologic effects of Taxol on neurons of the freshwater snailLymnaea stagnalis

Summary Cerebral ganglia of the freshwater snailLymnaea stagnalis were incubatedin vitro in 10 M Taxol for 8 and 24 h. Cremophor EL (0.1%) was used as a diluant. The tissue was processed for electron microscopy. Various ultrastructural parameters were assessed quantitatively. Cremophor EL appeared to seriously affect the cell somata of the multipeptidergic caudodorsal cells. In the Cremophor-controls the mean area of Golgi zones, the percentage dense material (neuropeptides) in these zones, the number of large electron dense granules (these are involved in neuropeptide processing) and the mean nuclear heterochromatin clump size, were significantly smaller than in the Ringer-controls, whereas the number of lipid droplets was higher. All these parameters, except for the lipid droplets, were not different in the Cremophor-controls and the Taxol-treated specimens. After 24 h treatment, but not after 8 h, Cremophor EL furthermore induced an increase in the number of axonal microtubules. It is argued that the results might signify activation of the neurons by Cremophor EL. Taxol induced a significant increase in the number of microtubules in axons and cell somata. Furthermore an increase in the number of Golgi zones was observed, suggesting activated neuropeptide synthesis. In all groups immunostaining with antibodies to neuropeptides produced by the caudodorsal cells was normal. Release of neuropeptide (exocytosis) from axon endings was elevated after Taxol treatment, and exceptionally high in specimens cotreated with Taxol and Org 2766 (incubation time 22 h). The effect of Org 2766 and Taxol on the number of microtubules was cumulative. It is argued that transport of neuropeptide granules from the cell somata to the axon terminals was not affected by Taxol. It is concluded that Taxol neurotoxicity is probably not due to impeded microtubular axonal transport.     

New anastomosis technique for (laparoscopic) instrumental small-diameter anastomosis

This study presents a new technique for visceral anastomosis. The principle consists of connecting the two parts to be anastomosed around a reabsorbable stent which is transluminally introduced into a small-diameter viscus, where it is fixed. Advancing a larger tube along the axis of the machine, the larger, perforated viscus is inverted and pulled over the stent, and finally a rubber band pops off the machine endoluminally in order to fix the intestinal walls in seroserosal contact onto the stent. To evaluate this micro anastomosis, a biliary bypass (choledochojejunostomy and roux-en-y-loop) was performed in ten pigs. Nine of ten animals showed biliary bypass with good runoff in contrast radiography and completely reabsorbed stent after a 3-month follow-up. Weight gain, bilirubin, and alkaline phosphatase were normal. This technology demonstrates a safe and quick way to perform instrumental micro anastomosis without remnant foreign material.Presented as a poster at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Nashville, TN, USA, 18–19 April 1994     

金石散胶囊溶解胆石的临床研究

自１９８７年迄今,用金石散（４－６胶囊／次,２－３次／天）治疗胆结石患者１７７例,３月为一疗程,共２－４疗程。治疗前后均经Ｂ超检查以判断疗效。结果显示：１．服药一月,９０％病人的发热、腹胀、疼痛等临床症状消失。２、６２例胆囊结石经服药平均８．１８＋７．１４月后,３例结石完全消失（４．８４％）,３７例结石减少变小,总有效率６４．５２％;而临床类型型相似的另外２３例,用ＵＤＣＡ治疗作为对照组,总有效率     

Growth hormone secretion in children and adolescents with familial tall stature

Sixty-five patients (22 boys and 43 girls) presenting with familial tall stature were investigated with regard to growth hormone (GH) secretion, both physiological and after stimulation with thyrotropin releasing hormone (TRH) and growth hormone relasing hormone (GHRH). Plasma insulin-like growth factor-I (IGF-I) was also measured. Two groups of patients were distinguished according to their physiological secretion of GH: a high secretory group (n=49) with a mean 24 h integrated concentration of GH (IC-GH) of 5.4±2.3 g/l per minute and a large number of peaks (5.1±1.6 in 24 h), and a low secretory group (n=16) with a mean 24 h IC-GH of 2.1±0.5 g/l per minute and few peaks (3.3±1.3 in 24h). Plasma IGF-I levels and GH peak values after the TRH test were significantly higher in the high secretory group. These results indicate that familial tall stature is the consequence either of hypersecretion of GH or of hypersensivity to this hormone (IGF-I levels being normal in spite of low GH levels).     

Bile-duct diameter at the porta hepatis and liver biopsies in Indian children with biliary atresia

Fibrous remnants from the porta hepatis and wedge biopsies of the liver were studied in 60 patients with biliary atresia. The patients were divided into three groups on the basis of bile duct diameter — I: no ducts; II: <50 m; III: >50 m. The liver damage was classified into three grades on the basis of ductular and parenchymal histopathologic changes and extent of inflammatory pathology. There was no correlation between severity of hepatic damage and duct diameter, although the levels of serum bilirubin and alkaline phosphatase varied in direct proportion to the degree of hepatic damage. There was an inverse relationship between age and duct diameter, but neither correlated with bile flow at surgery or in the postoperative period. The data suggest that Indian children with biliary atresia follow a different clinical course compared to those from Japan and Western countries. Correspondence to: V. Bhatnagar