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At least 19 recordsLinked to original sources

[Computed tomography of pancreatic cystic fibrosis].

The computer tomographic appearances of atrophic and lipomatous degeneration of the pancreas in cystic pancreatic fibrosis are described. CT exploration of the pancreas is recommended, particularly in differential diagnostic aspects of cystic fibrosis.

Adolescent↗

Defective regulation of gap junctional coupling in cystic fibrosis pancreatic duct cells.

The cystic fibrosis (CF) gene encodes a cAMP-gated Cl- channel (cystic fibrosis transmembrane conductance regulator [CFTR]) that mediates fluid transport across the luminal surfaces of a variety of epithelial cells. We have previously shown that gap junctional communication and Cl- secretion were concurrently regulated by cAMP in cells expressing CFTR. To determine whether intercellular communication and CFTR-dependent secretion are related, we have compared gap junctional coupling in a human pancreatic cell line harboring the DeltaF508 mutation in CFTR and in the same cell line in which the defect was corrected by transfection with wild-type CFTR. Both cell lines expressed connexin45 (Cx45), as evidenced by RT-PCR, immunocytochemistry, and dual patch-clamp recording. Exposure to agents that elevate intracellular cAMP or specifically activate protein kinase A evoked Cl- currents and markedly increased junctional conductance of CFTR-expressing pairs, but not in the parental cells. The latter effect, which was caused by an increase in single-channel activity but not in unitary conductance of Cx45 channels, was not prevented by exposing CFTR-expressing cells to a Cl- channel blocker. We conclude that expression of functional CFTR restored the cAMP-dependent regulation of junctional conductance in CF cells. Direct intercellular communication coordinates multicellular activity in tissues that are major targets of CF manifestations. Consequently, defective regulation of gap junction channels may contribute to the altered functions of tissues affected in CF.

Cell Communication↗

Sulfation of chondroitin/dermatan sulfate by cystic fibrosis pancreatic duct cells is not different from control cells.

Cystic fibrosis is associated with mutations of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated plasma membrane chloride channel. Cystic fibrosis patients have been reported to possess elevated sulfation of glycoconjugates, which may contribute to the pathogenesis of the disease. Sulfation of glycosaminoglycans by a cystic fibrosis pancreatic adenocarcinoma cell line homozygous for DeltaF508 (CFPAC-1), a control pancreatic cell line (PANC-1), two CFPAC-1 cell lines transfected with the gene for CFTR (PLJ-CFTR-4.7, TR20), and a mock-transfected CFPAC-1 control (PLJ-6) was investigated. Cells were radiolabeled with [35S]sulfate and [3H]glucosamine, and glycosaminoglycans secreted into the medium after 24 and 72 h were isolated. Chondroitinase ABC digestion of chondroitin/dermatan sulfate allowed the recovery of disaccharides which were analyzed for their degree of sulfation by strong anion-exchange HPLC. No differences in the extent of sulfation by any of the cell lines were noted. However, glycoaminoglycans synthesized by cystic fibrosis cells consistently exhibited twofold higher [35S]-sulfate:[3H]glucosamine ratios than the controls. We conclude that CFTR plays no role in the sulfation of chondroitin/dermatan sulfate by pancreatic cells and that isotope incorporation ratios alone are insufficient evidence of changes in sulfation levels.

Cell Line↗

Exocrine pancreatic function in cystic fibrosis.

Pancreatic dysfunction in cystic fibrosis (CF) begins in utero and, at birth, in most cases, cystic fibrosis is characterized by an elevated level of serum immunoreactive trypsin (IRT). If most patients with CF typically present insufficient pancreatic exocrine function, 10-15% of CF patients have pancreatic sufficiency and this status is genetically determined by one or two 'mild' mutations in CF transmembrane conductance regulator (CFTR). However, with age, these patients can develop pancreatic insufficiency.

Cystic Fibrosis↗

Purinergic regulation of anion secretion by cystic fibrosis pancreatic duct cells.

The present study explored regulation of anion secretion across cystic fibrosis pancreatic ductal epithelium by extracellular ATP with the short-circuit current (Isc) technique. CFPAC-1 cells grown on Millipore filters formed polarized monolayers with junctional complexes as revealed by light and electron microscopy. The cultured monolayers exhibited an increase in Isc in response to apical application of ATP in a concentration-dependent manner (concentration eliciting 50% of maximal response = 3 microM). Replacement of Cl- in the bathing solution or treatment of the cells with a Cl- channel blocker, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), markedly reduced Isc, indicating that a substantial portion of ATP-activated Isc was Cl- dependent. The effects of different adenosine nucleosides and/or nucleotides on Isc were also studied to identify the type of purinoceptors involved. The order of potency, ATP = UTP > ADP > adenosine, was consistent with that for P2 purinoceptors. Reactive blue 2 (100 microM), a P2 antagonist, was found to inhibit 86% of ATP-induced Isc. ATP-induced Isc was also inhibited by pretreatment of the cells with a Ca2+ chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (50 microM). Confocal microscopic study also demonstrated a rise in intracellular Ca2+ with stimulation by extracellular ATP, indicating a role of intracellular Ca2+ in mediating the ATP response. ATP-induced Isc was observed in monolayers whose basolateral membranes had been permeabilized by nystatin, which was also sensitive to apical addition of DIDS, suggesting that Isc was mediated by apical Cl- channels. The results of the present study demonstrate the presence of a purinergic regulatory mechanism involving P2U receptor and Ca2+ mobilization in pancreatic duct anion secretion.

Adenosine Triphosphate↗

Ranitidine in children with peptic ulcer and patients with pancreatic cystic fibrosis.

This article describes experience of the use of ranitidine in children with peptic ulcer and patients with pancreatic cystic fibrosis. Ranitidine proved to be efficacious and well tolerated, the percentage of healing being 89.4%. Ranitidine was also used in subjects with gastritis from Campylobacter pylori, obtaining rapid regression of subjective symptoms. Administration of ranitidine to cystic fibrosis patients improved the efficacy of the pancreatic extract, with consequent enhancement of digestive compensation.

Administration, Oral↗

Defective ATP-dependent mucin secretion by cystic fibrosis pancreatic epithelial cells.

The response of confluent monolayers of normal and cystic fibrosis (CF) pancreatic epithelial cells to stimulation by extracellular ATP and ATP analogues was investigated in terms of mucin secretion. Mucin secretion was measured as release of M1 antigens by a direct sandwich enzyme immunoassay. Extracellular ATP provoked rapid (< or = 15 min) and strong mucin secretion (+ 480 +/- 35%) by the normal pancreatic cell lines but was not able to induce mucin secretion by the CF cell lines. The order of efficacy of nucleotide agonists with ATP > ADP > AMP > adenosine was that of typical P2-purinergic receptors. ATP induced a rapid and transient intracellular [Ca2+] mobilization in both normal and CF pancreatic epithelial cells. This work demonstrated that CFTR seemed to mediate ATP-dependent mucin secretion.

Adenocarcinoma↗

Bak Foong Pills stimulate anion secretion across normal and cystic fibrosis pancreatic duct epithelia.

The present study examined the effect of Bak Foong Pills (BFP), an over-the-counter traditional Chinese medicine (China registration no. Z980035), on anion secretion and the underlying signaling pathways in normal and cystic fibrosis pancreatic duct cell lines, CAPAN-1 and CFPAC-1, respectively, using the short-circuit current technique. Apical addition of BFP ethanol extract (600 microg/ml) induced a fast transient I(SC) peak that was followed by a slower but more sustained increase in I(SC) in CAPAN-1 cells. However, the response to BFP in CFPAC-1 was predominantly the first transient peak. Apical addition of DIDS (200 microM) inhibited the first peak by more than 60% in both cell lines without significantly affecting the second I(SC) rise. More than 85% of the BFP-induced first transient in both cell lines was inhibited when extra and intracellular Ca(2+) was chelated or emptied by pre-treatment with BAPTA (100 microM) and thapsigargin (10 microM), respectively. Acute addition of PMA (1 microM), a PKC activator, blocked more than 95% of the BFP-induced first peak in both cell lines, consistent with previously reported PKC modulation of Ca(2+)-dependent pancreatic anion secretion. The BFP-induced second I(SC) rise in CAPAN-1 could be inhibited by 73.6% and 71.13% by pretreatment of the cells with MDL-12330A (20 microM), an adenylate cyclase inhibitor and Rp-cAMP (200 microM), a cyclic AMP antagonist, respectively. However, less than 25% of the I(SC) was inhibited by combined treatment with BAPTA and thapsigargin. The second rise was also completely blocked by DPC (2mM) or Glibenclamide (1mM). The results indicate that BFP ethanol extract stimulates pancreatic duct anion secretion in normal and CF cells via different signaling pathways involving both Ca(2+) and cAMP.

Anions↗

Angiotensin II-mediated signal transduction events in cystic fibrosis pancreatic duct cells.

Different signal transduction pathways, i.e. Ca2+- and cAMP-dependent, involved in mediating the effects of angiotensin II (AII) were investigated separately using the short-circuit current (Isc) technique and radioimmunoassay (RIA) in a cystic fibrosis pancreatic cell line (CFPAC-1) which exhibits defective cAMP-dependent but intact Ca2+-dependent anion secretion. The AII-induced Isc could be inhibited by the specific antagonist for AT1, losartan (1 microM), but not the antagonist for AT2, PD123177 (up to 10 microM). The AII-induced Isc was also reduced by the treatment of the cells with a Ca2+ chelator, BAPTA-AM (100 microM), indicating a dependence of the AII-induced anion secretion on the intracellular Ca2+. Treatment of the cells with pertussis toxin (0.1 microg/ml) or a phospholipase C (PLC) inhibitor, U73122 (5 microM), resulted in a substantial reduction in the AII-induced Isc indicating involvement of Gi and PLC in the Ca2+-dependent anion secretion. RIA measurements showed that AII stimulated an increase in cAMP production which could be reduced by losartan, pertussis toxin and U73122 but not BAPTA-AM. In addition, inhibitors of cyclooxygenase, indomethacin (10 microM) and piroxicam (10 microM), did not have any effect on the AII-induced cAMP production, excluding the involvement of prostaglandins. Our results suggest that both AII-stimulated cAMP and Ca2+-dependent responses are mediated by the AT1 receptor and Gi-coupled PLC pathway. However, the AII-stimulated cAMP production in CFPAC-1 cells is not dependent on Ca2+ or the formation of prostaglandins.

Angiotensin II↗

cAMP-activated Cl channels in CFTR-transfected cystic fibrosis pancreatic epithelial cells.

Retrovirus-mediated transfection of cDNA for the cystic fibrosis (CF) gene into the CF pancreatic cell line, CFPAC-1, confers adenosine 3',5'-cyclic monophosphate (cAMP)-dependent regulation of Cl conductance. We used patch-clamp techniques to identify the single-channel basis of this conductance pathway and to study its properties. Forskolin or cAMP activated Cl channels with a conductance of 9 +/- 1 pS in 26 of 62 cell-attached patches of cystic fibrosis transmembrane conductance regulator (CFTR)-transfected CFPAC-1 cells. The current-voltage (I-V) relation showed slight outward rectification (chord conductance of 10 +/- 2 pS at +80 mV vs. 7 +/- 1 pS at -80mV) with high Cl concentrations (170 mM) in the pipette solution. Channel kinetics were voltage sensitive, with longer openings at positive clamp voltages. Channel properties were unaffected by the substitution of N-methyl-D-glucamine for pipette Na or by the addition of disulfonic stilbenes (100 microM DNDS or DIDS) to the pipette. The channels usually inactivated within seconds of patch excision, but in three of nine patches, activity could be maintained by addition of the catalytic subunit of protein kinase A and ATP. With equal Cl concentrations on both membrane surfaces, the single-channel I-V relation was linear, suggesting that the outward rectification of the cell-attached channel is due to a pipette-to-cell Cl gradient. Anion substitution on the extracellular side of the membrane indicates a halide permselectivity of Br approximately Cl greater than I.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Line, Transformed↗