摘要:

A continuously increasing number of gene changes have been identified in pancreatic cancer. Similar abnormalities, however, have also been detected in other malignancies. The only exception is the high incidence of K-ras point mutation at codon 12. This article examines the significance of K-ras point mutation in pancreatic cancer for the definition of tumor entities, identification of high risk groups, discrimination between inflammatory and neoplastic lesions, and diagnosis of ductal changes with preneoplastic potential.

ISSN:0253-4886    

DOI:10.1159/000172249

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Genetic intervention is now a rational therapy for cancer, both to treat established malignancy and to reduce risk in predisposed individuals. Somatic gene therapy can be grouped into tumour suppressor gene replacement, oncogene blockade, genetic immunomodulation, genetic prodrug activation and polynucleotide vaccination. Each of these approaches has potential applications in pancreatic cancer, and this tumour type may be a suitable model for clinical trial.

ISSN:0253-4886    

DOI:10.1159/000172250

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Peptide and growth factor receptors are frequently expressed in high density in human tumors. A particularly high abundance of receptors for the peptide somatostatin (SS) is found in neuroendocrine tumors of the pancreas and gastrointestinal tract. 90% of the carcinoids and a majority of islet cell carcinomas, including their metastases, have usually a high density of SS receptors. The number of receptors correlates with the degree of differentiation of the tumor. Several different SS receptor subtypes can be expressed by these tumors, the SSTR2 subtype being the most frequently and abundantly expressed. The somatostatin receptors in tumors are identified with in vitro binding methods, molecular biology techniques or in vivo imaging techniques; the latter allow the precise localization of the tumors and their metastases in the patients. Since SS receptors in human hormone-producing gastroenteropancreatic tumors are functional, their identification can be used to predict the therapeutic efficacy of octreotide to inhibit excessive hormone release. Undifferentiated tumors, such as atypical carcinoids, exocrine pancreatic carcinomas and most of the colorectal carcinomas, usually do not express SS receptors in the tumor itself, but, interestingly, may trigger the expression of SS receptors in the peritumoral veins, where SS may play a role in hemodynamic tumor-host interactions.

ISSN:0253-4886    

DOI:10.1159/000172251

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Several recent studies strongly suggest that pancreatic cancer causes in the majority of patients type II diabetes that can be improved or cured by subtotal pancreatectomy. Our studies have shown alterations of hormone production in islets adjacent to cancer and the presence of abnormal endocrine cells, including insulin, glucagon, somatostatin, pancreastatin and serotonin, by tumor cells. Alterations of insulin-like amyloid polypeptides (IAPP) were found in islets surrounding the tumor and their production in some cancer cells. A significantly higher IAPP level was found in the plasma of pancreatic cancer patients than in those with other types of cancers. It appears that an increase in plasma IAAP could present an early marker for pancreatic cancer.

ISSN:0253-4886    

DOI:10.1159/000172252

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The vast majority of patients with acute pancreatitis either have gallstones or drink too much alcohol. While little is known about the action of ethanol on the exocrine pancreas, the mechanisms involved in gallstone-induced pancreatitis have recently been elucidated to an extent that allows conclusions about the pathophysiology of pancreatitis. In the following review article we will discuss the clinical and experimental studies which have shaped our understanding of biliary pancreatitis. While most of the questions regarding the association of gallstones and pancreatitis appear to be resolved, the intracellular alterations which immediately follow these triggering events and ultimately lead to acinar cell necrosis are less well understood. These early pathophysiological changes within the pancreas have been the target of an intense research interest and the subject of sometimes equally passionate controversies. We will discuss the studies that have addressed the premature and intracellular activation of digestive enzymes in acute pancreatitis and review some of the current theories and arguments which attempt to confront this issue.

ISSN:0253-4886    

DOI:10.1159/000172253

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Various definitions and classification systems of acute and chronic pancreatitis have been elaborated in the past 3 decades and are critically reviewed in this article. According to these classifications acute pancreatitis is characterized by complete recovery, whereas chronic pancreatitis implies irreversible morphological and functional changes, which usually can only be proven in an already advanced disease state. Acute and chronic pancreatitis so far represents two different disease entities. The classifications have no word for the chronic inflammatory process that ultimately leads to pancreatic destruction, but does not yet yield abnormal imaging procedures and function tests. More interdisciplinary research in early chronic pancreatitis is needed to better understand its pathophysiology.

ISSN:0253-4886    

DOI:10.1159/000172254

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Determination of serum pancreatic enzymes remains the gold standard for the diagnosis of acute pancreatitis. Clinical symptoms and signs are of major importance in suspecting the disease, but they are not accurate enough to confirm the diagnosis. The different serum pancreatic enzymes have a similar accuracy in the diagnosis of acute pancreatitis. Total amylase, pancreatic isoamylase and lipase are preferred, since simple, rapid and inexpensive enzymatic methods are commercially available. More expensive and cumbersome methods (e.g. RIA or ELISA for pancreatic elastase) are useful only in special clinical circumstances. For early etiological classification of acute pancreatitis serum pancreatic enzymes and even different enzyme ratios are not reliable. For this purpose, determination of AST, bilirubin and alkaline phosphatase may make it possible to distinguish between biliary and nonbiliary origin of the disease. Ultrasonography and computed tomography provide very valuable information regarding not only etiology but also local complications of acute pancreatitis. Once the diagnosis of acute pancreatitis has been established, prognostic classification of the disease is required for adequate monitoring and treatment. Clinical symptoms and signs do not allow early assessment of the prognosis of acute pancreatitis. Multivariate scoring systems are sensitive but not sufficiently specific for the identification of severe pancreatitis. Among several biochemical markers commercially available for the assessment of severity, C-reactive protein and PMN-elastase appear to be the most valuable. These markers allow a proper selection of patients who need further investigation by contrast-enhanced CT (the gold standard for detection of pancreatic necrosis).

ISSN:0253-4886    

DOI:10.1159/000172255

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

This review of non-invasive imaging procedures in acute pancreatitis points to the role of ultrasound and covers the findings, advantages and disadvantages of CT and MR imaging. CT is still the primary method in assessing larger areas of necrosis as well as fluid collection while MR imaging might be more sensitive for early inflammatory changes. Since the composition of fluid collections cannot be differentiated, there is a role for fluid aspiration and/or drainage in case of suspected infection.

ISSN:0253-4886    

DOI:10.1159/000172256

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Bacterial infection is without any doubt the most important risk factor in patients suffering from acute necrotizing pancreatitis determining the course of the disease, its therapeutic management and outcome. The infection route by which the bacteria enter the necroses is very likely via the colon as demonstrated by animal studies. Infection occurs very early and the frequency of infected pancreatic necrosis is about 40-70% in unselected patients. The spectrum of bacteria most frequently found are germs from the intestine, like Eschericha coli, Pseudomonas spp., Streptococcus faecalis, Enterococcus and Staphylococcus aureus. Screening for infected pancreatic necrosis is of outermost importance. In this respect fine needle aspiration by ultrasound or CT guidance with gram staining and culture is the most reliable and harmless procedure to search for infected pancreatic necrosis. Especially patients with suspected infection should undergo fine needle puncture. There is evidence that patients with acute necrotizing pancreatitis will profit by an early and appropriate antibiotic therapy. In 5/15 (33%) patients with proven acute necrotizing pancreatitis infected pancreatic necroses were found by fine needle aspiration analysis after a mean of 21 ± 3.3 days after the onset of the disease. In these patients antibiotic treatment with imipenem was started immediately after hospital admission for at least 14 days. This new concept and therapeutic approach resulted in a lower infection rate as well as delayed infection of pancreatic necrosis in the 3rd week of the disease with optimal surgical conditions in our preliminary study

ISSN:0253-4886    

DOI:10.1159/000172257

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Patients with pancreatic necrosis should receive a prophylactic antibiotic such as imipenem in the hope of reducing the likelihood of pancreatic infection. Those with severe gallstone pancreatitis should undergo endoscopic sphincterotomy. If common bile duct stones are visualized, endoscopic sphincterotomy and removal of stones should be undertaken. Patients with infected necrosis require surgical debridement. Those with sterile necrosis should generally be managed medically. The role of early surgical debridement for patients with sterile pancreatic necrosis who are experiencing increasing systemic toxicity remains unclear. Whenever possible, it is preferable to maintain prolonged medical supervision for 4-6 weeks, reserving surgical debridement at that time for late complications including inability to wean from respiratory support and refractory abdominal pain with attempts at oral refeeding. Ultimately, progress in the treatment of severe acute pancreatitis will depend on improved methods of limiting systemic complications, preventing pancreatic necrosis, and preventing pancreatic infection.

ISSN:0253-4886    

DOI:10.1159/000172258

出版商:S. Karger AG    

年代:1994

数据来源: Karger