Search

Background & Aims: Cellular infiltrates are present already in early stages of chronic pancreatitis. The mechanisms responsible for their recruitment are unknown. Hence, we determined the differential expression of chemokine genes and their cellular sources in normal and affected pancreatic tissues. Methods: Pancreatic tissues from 23 patients with chronic pancreatitis and from 4 normal controls were subjected to in situ hybridization for detecting messenger RNA (mRNA) of the chemokine genes interleukin 8, ENA-78, MIG, MCP-1, and I-309. Results: Normal pancreatic tissues lack cells expressing mRNA for IL-8, ENA-78, MIG, and MCP-1. In contrast, pancreatic lobuli with mild to moderate signs of tissue alterations strongly expressed MCP-1 mRNA in centroacinar ducts, endothelia, fibroblasts, macrophages, T cells, and occasionally in nerves. Interleukin 8 and ENA-78 mRNA is preferentially detected in centroacinar ducts of pancreatic lobuli with more advanced alterations. Variable numbers of pancreas-infiltrating T cells express MIG mRNA. I-309 mRNA, however, is consistently observed in normal acini and in tissue with mild to moderate signs of tissue alterations. Conclusions: The observed differential expression of distinct chemokine genes in pancreatic parenchyma and infiltrates from patients with chronic pancreatitis strongly suggests an involvement of distinct chemokines in the initiation and perpetuation of disease. GASTROENTEROLOGY 2000;118:356-367

Background & Aims:Bone morphogenetic proteins (BMPs) belong to the transforming growth factor β superfamily of signaling molecules. We characterized the expression of BMP-2 and its receptors in human pancreatic tissues and pancreatic cancer cell lines and examined the effects of BMP-2 on mitogenesis. Methods:Expression of BMP-2 and its receptors was determined by Northern blot analysis using specific complementary DNA probes. Distribution of BMP-2 in pancreatic cancers was examined by immunohistochemistry and in situ hybridization. Effects of BMP-2 on mitogenesis were assessed by monitoring cell proliferation and activation of mitogen-activated protein kinase (MAPK). Results:Compared with the normal pancreas, pancreatic cancers showed a 12.5-fold (P< 0.01), 2-fold (P< 0.01), and 8-fold (P< 0.01) increase of BMP-2, BMP receptor (R)-IA, and BMPR-II messenger RNA levels, respectively. By immunohistochemistry and in situ hybridization, BMP-2 was expressed in the cancer cells within the tumor mass. There was a significant correlation between the presence of BMP-2 immunostaining in the tumors and shorter postoperative survival. Pancreatic cancer cell lines expressed variable levels of messenger RNA encoding BMP-2 and its receptors. BMP-2 stimulated the growth of two pancreatic cancer cell lines (ASPC-1 and CAPAN-1). This mitogenic effect was associated with MAPK activation and blocked by the MAPK inhibitor PD98059 in CAPAN-1 but not in ASPC-1 cells. In both cell lines, expression of wild-type Smad4 abolished the BMP-2–mediated growth stimulation. BMP-2 inhibited the growth of COLO-357 cells, an effect that was blocked by expressing a dominant negative Smad4. BMP-2 had no effect in three cell lines that underexpressed either the BMP receptors or Smad1. Conclusions:These findings indicate that BMP-2 has the capacity to act as a mitogen when Smad4is mutated and suggest that it might play a role in the pathobiology of human pancreatic cancer.

Background:Transforming growth factor βs (TGF-βs) constitute a family of bifunctional polypeptide growth factors that either inhibit or stimulate cell proliferation. Perturbations in TGF-β expression and function may lead to loss of negative constraints on cell growth. In this study, we examined TGF-β expression in human pancreatic cancer. Methods:The distribution of TGF-β isoforms in 60 human pancreatic cancers was examined using immunohistochemical, Northern blot, and in situ hybridization techniques. Results:Immunohistochemical analysis showed the presence of TGF-β1 (47% of tumors), TGF-β2 (42% of tumors), and TGF-β3 (40% of tumors) in the cancer cells. The presence of TGF-β2 was associated with advanced tumor stage (P< 0.05). Furthermore, there was a significant correlation between the absence of TGF-βs in the tumors and longer postoperative survival. Northern blot analysis indicated that, by comparison with the normal pancreas, pancreatic adenocarcinomas showed 11- (P< 0.001), 7- (P< 0.05), and 9-fold (P< 0.001) increases in the messenger RNA (mRNA) levels encoding TGF-β1, TGF-β2, and TGF-β3, respectively. By in situ hybridization, these mRNA moieties colocalized with their respective proteins in the cancer cells. Conclusions:These findings show that human pancreatic cancers show increased levels of TGF-β isoforms and enhanced TGF-β mRNA expression and suggest that the presence of TGF-βs in pancreatic cancer cells may contribute to disease progression.

BACKGROUND & AIMS:Changes in innervation pattern and neuropeptide content have been shown in chronic pancreatitis (CP), including increased neuronal expression of growth-associated protein 43 (GAP-43). We used GAP-43 as an established marker of neuronal plasticity and correlated histological findings with pain scores of patients with CP. METHODS:In tissue samples from 29 patients with CP, the parenchyma- fibrosis ratio, degree of perineural immune cell infiltration, and neuronal GAP-43 immunoreactivity were determined by digitized morphometry and correlated with individual pain scores. RESULTS:In CP, GAP-43 was significantly increased in pancreatic nerve fibers and intrinsic neurons. GAP-43 expression correlated with individual pain scores. The infiltration of pancreatic nerves by immune cells was significantly correlated with the intensity of pain. Pain scores correlated neither with the degree of pancreatic fibrosis nor with the duration of the disease. CONCLUSIONS:The results suggest that infiltration of pancreatic nerves by immune cells and neuronal plasticity are pathogenic factors for the generation of pain, whereas the degree of pancreatic fibrosis has no major impact on pain in CP. (Gastroenterology 1997 May;112(5):1648-55)

BACKGROUND & AIMS:Perforin messenger RNA (mRNA) expression has been shown to be a specific in vivo activation marker for cytotoxic cells. In this study, the contribution of cell-mediated cytotoxicity in the pathogenesis of alcoholic chronic pancreatitis is assessed. METHODS:Tissue sections of patients with alcoholic chronic pancreatitis were analyzed for perforin mRNA expression by in situ hybridization. In a further step, the phenotype and the relative frequency of perforin mRNA- expressing cells were determined. RESULTS:In the normal pancreas, perforin mRNA-expressing cells are rarely present (mean, 0.3 cells/mm2). In contrast, the frequency of perforin mRNA-expressing cells is increased severalfold in diseased tissue specimens (mean, 6.6 cells/mm2). The frequency of perforin mRNA-expressing cells is high in the CD56+ (18%) and CD8+ cell population (12%) but low in the CD4+ cell population (1%). CONCLUSIONS:The significantly elevated frequencies of perforin mRNA-expressing cells in the pancreas of patients with alcoholic chronic pancreatitis suggest an involvement of cell-mediated cytotoxicity in the pathogenesis of this disease. The preferential localization of these activated cells close to areas with parenchyma provides circumstantial evidence that autoreactive cytotoxic cells may contribute to tissue destruction in alcoholic chronic pancreatitis. (Gastroenterology 1997 May;112(5):1656-63)

Background & Aims:Feedback regulation of pancreatic enzyme secretion is well established in animals, and their pancreases are able to adapt to intraduodenal inhibition of pancreatic enzymes by proteinase inhibitors such as Camostate (FOY-305; Schwarz GmbH, Monheim, Germany). In this study, we addressed whether similar adaptive changes occur in the human pancreas after 4 weeks of 2 g/day Camostate application. Methods:Before, at the end of, and 2 weeks after 4-week Camostate treatment (four times 500 mg daily), pancreatic changes were analyzed with the use of a secretin-cerulein test, a test-meal stimulation, cholecystokinin plasma measurement, and standardized ultrasonographic investigations of the pancreas. Results:Duodenal trypsin output after secretion stimulation was significantly increased (+44%; P< 0.01) and duodenal bicarbonate output decreased 22% (P< 0.05) after 4 weeks of Camostate application. The size of the pancreatic head (vertical) increased 8% (P< 0.05) at week 4 and decreased to pretreatment values 2 weeks after treatment (week 6). The other three diameters measured (head oblique, body, and tail) showed a similar pattern. Stimulated cholecystokinin plasma levels 15 minutes after application of a standard test meal increased 62% (P< 0.05). Conclusions:The human pancreas adapts to oral application of the proteinase inhibitor Camostate. These findings support the theory that feedback control of the exocrine pancreas operates in humans.

GASTROENTEROLOGY 1998;115:1018-1022

In a prospective clinical trial, 85 patients with acute pancreatitis, including 50 with acute interstitial-edematous pancreatitis and 35 with necrotizing pancreatitis, were recruited. Serum pancreatic immunoreactive phospholipase A2(IR-PLA2), serum phospholipase A catalytic activity (CA-PLA), and serum phospholipase A2catalytic activity (CA-PLA2) were determined daily between day 1 and day 10 after the onset of the disease. The serum course of IR-PLA2values for patients with acute interstitial-edematous pancreatitis was comparable to that for patients with necrotizing pancreatitis. In contrast, the determination of CA-PLA and of CA-PLA2specific activity in the serum revealed a high differentiation between patients with interstitial edematous and those with necrotizing pancreatitis. The overall accuracy for differentiating patients with necrotizing pancreatitis from those with the interstitial-edematous type was 79% for CA-PLA and 77% for CA-PLA2(cut-off level: CA-PLA, 15 U/L, day 1–5; CA-PLA2, 3.5 U/L, day 1–5). Patients with pancreatitis-associated pulmonary complications showed significantly higher CA-PLA and CA-PLA2values in the serum. This study demonstrates the role of serum catalytic phospholipase A2in human acute pancreatitis where the development of pancreatic necrosis and pulmonary failure is concerned.

BACKGROUND & AIMS: Urokinase plasminogen activator (uPA) regulates plasmin generation from plasminogen. The aim of this study was to analyze the role of the plasminogen activator/plasmin system in chronic pancreatitis (CP). METHODS: Using Northern blot analysis, in situ hybridization, and immunohistochemistry, the expression of uPA, its receptor (uPAR), plasminogen activator inhibitor 1 (PAI-1), and transforming growth factor beta 1 (TGF-beta 1) was studied in 14 patients undergoing pancreatic resection for CP. Normal control pancreatic tissue was obtained through an organ donor program. RESULTS: Eight of 14 CP samples showed concomitant increased expression (P < 0.001) of uPA (5.2-fold), uPAR (5.9-fold), and TGF-beta 1 (8.8-fold) messenger RNA (mRNA) compared with normal controls. PAI-1 mRNA expression was increased (6.5-fold; P < 0.001) in all CP samples. By in situ hybridization, moderate to strong mRNA staining of all four factors was present in acinar cells, some ductal cells, and areas with ductal metaplasia in CP samples. A similar staining pattern was found by immunohistochemistry. Intense mRNA and immunostaining for all of these factors in CP samples was associated with a higher degree of pancreatic damage. CONCLUSIONS: uPA and its receptor may contribute to the lytic damage observed in CP by plasmin generation. Similarly, increased amounts of plasmin may activate latent TGF-beta, thereby leading to the accumulation of fibrotic tissue. (Gastroenterology 1997 Sep;113(3):904-13)

BACKGROUND & AIMS: Gastrin and cholecystokinin (CCK) are gut-brain peptides, with multiple functions in the gastrointestinal tract mediated through CCK-B-gastrin and CCK-A receptors. The receptor localization is, however, not well established in humans. The aim of this study was to investigate the distribution and pharmacological characteristics of CCK-A and CCK-B receptors in the human upper gastrointestinal tract and compare them with those in the rat and dog. METHODS: CCK receptors were localized by in vitro receptor autoradiography with 125I-[Leu15]gastrin-I and 125I-[D-Tyr-Gly, Nle(28,31)]-CCK 26-33 in stomach and gallbladder. RESULTS: High concentrations of CCK-B-gastrin receptors were detected in the midglandular region of the human fundic mucosa. CCK-A receptors were found in the basal region of the antral and fundic mucosa. CCK-A receptors were also located in the muscularis propria of antrum, fundus, and gallbladder, whereas CCK-B-gastrin receptors were only detected in gastric fundic circular muscle. Two nonpeptide CCK receptor antagonists distinguish both receptor subtypes. Comparisons among humans, dogs, and rats suggest that localization and density of CCK receptor subtypes in the upper gastrointestinal tract are species- dependent. CONCLUSIONS: Localization of CCK receptor subtypes in human upper gastrointestinal tract provides a biochemical and morphological basis for the separate regulatory roles of gastrin and CCK. (Gastroenterology 1997 Apr;112(4):1197-205)

Pancreatic infection represents the most important cause of fatal outcome in human acute pancreatitis. In a comparative analysis, human pancreatic tissue concentrations of 10 different bactericidal antibiotics were determined in 89 patients undergoing pancreatic surgery. Concentrations of the antibiotics were determined in the blood and pancreatic tissue using high-pressure liquid chromatography. Pancreatic tissue concentrations 120 minutes after intravenous administration were as follows: mezlocillin, 19.0 mg/kg; piperacillin, 20.3 mg/kg; cefotaxime, 9.1 mg/kg; ceftizoxime, 7.9 mg/kg; netilmicin, 0.4 mg/kg; tobramycin, 0.4 mg/kg; ofloxacin, 1.7 mg/kg; ciprofloxacin, 0.9 mg/kg; imipenem, 6.0 mg/kg; metronidazole, 3.5 mg/kg. Three groups of antibiotics were established: group A, substances with low tissue concentrations (netilmicin, tobramycin), which were below the minimal inhibitory concentrations of most bacteria found in pancreatic infection; group B, antibiotics with pancreatic tissue concentrations which were sufficient to inhibit some but not all bacteria in pancreatic infection (mezlocillin, piperacillin, ceftizoxime, cefotaxime); group C, substances with high pancreatic tissue levels as well as high bactericidal activity against most of the germs present in pancreatic infection (ciprofloxacin, ofloxacin, imipenem). These data could serve as the basis for adequate antibiotic prophylaxis or treatment of pancreatic infection.