Transient transcriptional activation of gastrin during sodium butyrate-induced differentiation of islet cells

Transient expression of pancreatic gastrin corresponds to a period of rapid islet cell development. After birth gastrin expression silencing is coincidental with islet cell terminal differentiation, while persistent expression is accompanied with nesidioblastosis and reexpression observed in islet cell tumors. Experiments with transgenic animals suggested that gastrin might act synergistically with growth factors to stimulate islet cell development. The present study intended to establish an in vitro cell culture model to analyse the molecular events controlling gastrin gene activation and repression dependent on islet cell differentiation. Sodium butyrate, a proliferation-arresting compound has previously been shown to differentiate insulinoma cells while increasing insulin production. The present paper demonstrates concomitant transient increase in gastrin mRNA, intracellular and secreted gastrin during sodium butyrate treatment. Increased gastrin expression was due to activation or derepression of gastrin promoter activity as revealed by promoter analyses. This in vitro model mimics the expression pattern of gastrin and insulin observed during fetal islet cell development and provides an excellent tool to analyse the molecular mechanisms controlling gastrin gene activation and selective repression during islet cell differentiation.

[Studies on the protective effect of lansoprazole on human gastric mucosa against low-dose acetylsalicylic acid. An endoscopic controlled double-blind study]

In a randomized double-blind parallel study the gastroduodenal tolerability of 300 mg acetylsalicylic acid (ASA) daily has been evaluated in the presence of placebo, 15 mg lansoprazole (CAS 103577-45-3, Agopton) and 300 mg ranitidine daily (8 a.m.) in 30 healthy volunteers using upper gastrointestinal tract endoscopy. The treatment periods lasted 14 days. Endoscopic controls were performed at entry and repeated at day 14. At entry, the mean endoscopic score averaged 1.0 +/- 0.0 (+/- SEM) in the ASA/placebo (n = 10), in the ASA/ lansoprazole 15 mg (n = 10) and the ASA/300 mg ranitidine group. In the placebo experiments 300 mg ASA daily induced marked gastroduodenal lesions at day 14 (lesion score of 10.1 +/- 1.4) (+/- SEM). Concomitant administration of 15 mg lansoprazole daily offered significant protection against 300 mg ASA daily on day 14 (3.6 +/- 1.2) (p < 0.05), 300 mg ASA plus 300 mg ranitidine daily reduced the damaging score to 5.8 +/- 1.3 (p n.s. vs ASA/placebo). Our data suggest that co-administration of 15 mg lansoprazole daily reduces significantly gastroduodenal lesions evoked by 300 mg ASA.

Enolases are highly conserved fungal allergens

BACKGROUND

Lack of knowledge of the identity of fungal allergens still is a major obstacle for improvement of diagnosis and therapy of allergies to moulds. We have therefore further analyzed the allergens of the two moulds, Alternaria alternata and Cladosporium herbarum and found that enolases (EC 4.2.1.11) are major allergens, at least of the two fungal species just mentioned.

METHODS

The enolases of Alternaria and Cladosporium were cloned from cDNA libraries constructed from vegetative cells of the two moulds by immunological screening with sera from selected patients allergic to the moulds. The two enolases were expressed as recombinant nonfusion proteins and used for determination of the incidence of allergy to enolase among a cohort of patients.

RESULTS

Sequencing of the two enolases showed very close relationships with other known fungal enolase sequences. Competition experiments using immunoblots of the recombinant nonfusion proteins showed nearly complete identity of the epitopes on both enolases. Serum from a patient reactive to Cladosporium enolase reacted equally well with the enolases of Alternaria, Saccharomyces and Candida. About 50% each of the sera from patients reactive to Cladosporium and Alternaria were strongly reactive to the recombinant enolases.

CONCLUSIONS

Enolases are therefore considered to be highly conserved major fungal allergens.

[Influence of mechanisms of Pseudomonas aeruginosa resistance on the bactericidal activity of third generation cephalosporins]

Survey of resistance of beta-lactam's resistance of P. aeruginosa have to be conducted. 410 strains of P. aeruginosa ticarcilline resistant have been studied. 52% of these strains were cephalosporinase producing alone or in combination with penicillinase. beta-lactam's inhibitors are not fully efficient upon these strains. Upon cephalosporinase producing strains bactericidal activity of C3G is difficult to obtain. At low concentration selection of strains with upper MICs is observed. This phenomenon is not observed at high concentration of antibiotics. Cefepime show a good bactericidal activity against P. aeruginosa.

Gastric mucosa during treatment with lansoprazole: Helicobacter pylori is a risk factor for argyrophil cell hyperplasia

BACKGROUND & AIMS

The mechanisms causing progression of fundic gastritis and changes in argyrophil cell morphology in patients undergoing long-term treatment with proton pump inhibitors are unknown. The hypothesis of this study was that Helicobacter pylori is a risk factor for both gastritis and argyrophil cell hyperplasia.

METHODS

Forty-two patients with peptic disorders resistant to H2-blockers were treated with 30-90 mg lansoprazole daily for up to 5 years. Serum gastrin levels, antral gastrin cells, fundic argyrophil cells, parameters of gastritis, and H. pylori infection were evaluated regularly.

RESULTS

In nonantrectomized patients, serum gastrin levels increased from a median of 76 pg/mL to 163 pg/mL within 3 months. Antral gastrin cell density increased from 175 to 267 cells/mm2 (P < 0.001), and fundic argyrophil cell density increased from 83 to 149 cells/mm2 (P < 0.001). Chronic inflammation, activity, and atrophy of the oxyntic mucosa worsened exclusively in patients with H. pylori infection. Linear and/or micronodular argyrophil cell hyperplasia was diagnosed in 2.6% of patients before lansoprazole and in 29.2% after 5 years treatment. These changes were significantly related to serum gastrin levels, H. pylori infection, chronic inflammation, and atrophy of the oxyntic mucosa.

CONCLUSIONS

H. pylori represents an important factor for the progression of fundic gastritis and the development of argyrophil cell hyperplasia during long-term treatment with lansoprazole.

[Comparative endoscopic study of gastroduodenal tolerance of piroxicam-beta-cyclodextrin vs piroxicam]

The gastroduodenal tolerability of piroxicam-beta-cyclodextrine was evaluated in a double-blind, parallel group study in 32 healthy male volunteers. The doses used were 20 mg piroxicam-beta-cyclodextrin vs 20 mg piroxicam daily over a period of 14 days. Gastric tolerability was assessed by using upper endoscopy. Gastroscopy was performed at base-line and after the dosing period of 14 days. The mucosal lesions were scored using modified Lanza criteria. In comparison to piroxicam, piroxicam-beta-cyclodextrine was significantly better tolerated after a 14 day dosing period. Mean gastric-duodenal score: Piroxicam-beta-cyclodextrine 3 +/- 4 (median 1), piroxicam 6 +/- 4 (median 8). The score values for the stomach were for piroxicam-beta-cyclodextrin 2 +/- 3 (median 1) and for piroxicam 4 +/- 3 (median 6). The corresponding values for the duodenal bulb 2 +/- 4 (median 0) and 4 +/- 5 (median 0), respectively. Both drugs averaged were generally well tolerated. In summary, piroxicam-beta-cyclodextrin given as a 20 mg single oral morning-dose over a 14-day period was significantly better tolerated than piroxicam 20 mg with regard to gastroduodenal damage.

Dopaminergic and serotonergic properties of fluoxetine

1. Rats were trained to discriminate i.p. injections of a 5-HT agonist, LSD (0.08 mg/kg, n = 12) or a DA agonist, cocaine (10 mg/kg; n = 16) in a two lever, drug discrimination situation. 2. Animals were tested with fluoxetine (0.625-10 mg/kg) alone and in combination with low doses of the training drugs. 3. Fluoxetine did not substitute for either LSD or cocaine at any dose tested. A relatively low dose of fluoxetine (2.5 mg/kg) potentiated the discriminability of cocaine (2.5 mg/kg) from saline. A higher dose of fluoxetine (5.0 mg/kg) significantly enhanced the effects of a low dose of LSD (0.02 mg/kg), but only to 41.7% responses on the LSD-appropriate lever. 4. The data suggest that fluoxetine alters the discriminative stimulus properties of cocaine to a greater extent than those of LSD. 5. The ability of fluoxetine to potentiate the cocaine cue (but not to substitute for cocaine) suggests that both of those drugs affect DA systems, but do so through different mechanisms. For example, fluoxetine may not inhibit DA reuptake (to the same extent as cocaine), but may have other dopaminergic actions such as increasing DA receptor density.

High levels of circulating adrenomedullin in severe illness: correlation with C-reactive protein and evidence against the adrenal medulla as site of origin

Adrenomedullin (AM) is a novel vasorelaxing peptide which was originally isolated from the extracts of human pheochromocytoma. It is produced by a number of organs among which the adrenal gland exhibits by far the highest concentrations. The peptide circulates in blood and its plasma levels have been reported to be increased in several diseases such as renal failure and sepsis. In the present study plasma concentrations of AM were measured in various forms of severe illness and compared to clinical and biochemical parameters in order to gain an insight into the factors controlling the plasma levels of this peptide. The highest concentrations of AM were found in patients with sepsis (344.4 +/- 60.4 pg/ml, n = 16) who exhibited up to 12-fold higher levels than a group of healthy subjects (74.1 +/- 4.1 pg/ml, n = 20). Markedly elevated levels were also measured in hemorrhagic (250.1 +/- 37.9 pg/ml, n = 9) and cardiogenic (216.2 +/- 29.4 pg/ml, n = 7) shock as well as in patients with cancer of the gastrointestinal tract (155.6 +/- 32.5 pg/ml, n = 11) or the lungs (146.5 +/- 19.1 pg/ml, n = 22). Plasma AM levels were positively correlated with serum creatinine concentrations in shock (r = 0.06, p < 0.001) and with C-reactive protein levels in patients with cancer (r = 0.64, p < 0.001) or sepsis (r = 0.63, p < 0.01). In order to examine the potential role of the adrenal gland as a site of AM release, hypoglycemia was induced in a group of healthy volunteers by graded infusion of insulin. Despite a more than 20-fold increase in plasma adrenalin indicating maximal stimulation of the adrenal medulla, no significant alterations of the plasma AM levels were observed. The study demonstrates that not only sepsis but also various forms of cancer and shock are associated with high levels of circulating AM. The correlation with C-reactive protein levels suggests a role of cytokines in mediating the elevations in plasma AM observed in sepsis and cancer. Reduced clearance of the peptide by the kidneys may be one of the mechanisms involved in the accumulation of AM in shock. The adrenal gland appears not to be a major source for circulating AM.

[Helicobacter pylori eradication: modified triple therapy with lansoprazole]

For the eradication of Helicobacter pylori in H.p.-positive patients with peptic ulcer, preference is presently being given worldwide to the modified triple therapy-comprising an acid suppressant and two antibiotics. This relatively new form of treatment is highly effective, relatively well tolerated, patient-friendly (5 to 6 tablets daily), and inexpensive. In 12 studies involving more than 600 patients, the new proton pump inhibitor, lansoprazole, has proved to be an effective component of this eradication regimen. In combination with clarithromycin and metronidazole or amoxicillin and clarithromycin, consistently high eradication rates of more than 85% are obtained, with treatment of only seven days duration. Since in terms of clinical efficacy 30 mg lansoprazole daily presumably correspond to 40 mg omeprazole daily, the new proton pump inhibitor represents a more economic alternative for H.p. eradication.

Long-term functional status and mortality of elderly patients with severe closed head injuries

OBJECTIVE

To evaluate long-term clinical outcome of elderly patients with severe closed head injuries.

DESIGN

Retrospective study.

PATIENTS AND METHODS

All patients older than 65 years of age admitted to a regional trauma center with a diagnosis of closed head injury and an admission Glasgow Coma Scale (GCS) score of 8 or less. Using chi 2 analysis, Student's t test, and multiple logistic regression, we correlated age, sex, mechanism of injury, pupillary reactivity, alcohol and drug use, admission GCS score, Injury Severity Score, Revised Trauma Score, heart rate, and blood pressure to the main outcome measures, i.e. long-term functional outcome and mortality.

RESULTS

Among 40 elderly patients who met the criteria, 27% were still alive at the end of 38 +/- 3 month follow-up. Eighty-five percent of patients who were discharged from the hospital were still alive long-term, but did not show significant neurologic improvement. In a univariate analysis, GCS and pupillary reactivity were predictive for long-term functional outcome and mortality. In a multivariate analysis, GCS and heart rate were predictive. All patients with an admission GCS score of 3 died in-hospital. All patients with an admission GCS score of 3 to 7 were either deceased or lived in persistent vegetative or dependent functional states.

CONCLUSIONS

Elderly patients with severe closed head injuries have high in-hospital mortality. Those who survived the hospital stay had high long-term survival, but did not show significant functional improvement. Prediction of long-term functional status is vital to the trauma care of elderly patients with severe closed head injuries.

Evaluation of the VA's Pilot Program in Institutional Reorganization toward Primary and Ambulatory Care: Part I, Changes in process and outcomes of care

PURPOSE

To evaluate the impact of the reorganization of an academic Veterans Affairs medical center toward primary and ambulatory care--including the implementation of a medical-center-wide interdisciplinary firm system and ambulatory care training program--on the quality of primary ambulatory care.

METHOD

Randomly selected male veterans visiting the Veterans Affairs Medical Center in Sepulveda, California, were surveyed in 1992, early in the implementation of the program, and in 1993, after the program had been fully implemented. Two surveys were used: one before the veterans saw their primary care providers (practice-based survey) and the other immediately after patient visits (visit-based survey). Survey-participant data were then linked to computerized utilization and mortality data. Survey topics were mapped to the medical center's strategic plan and goals for ambulatory care, and focused on patients' reports about the care they had received in terms of continuity, access, preventive care, and other aspects of the biopsychosocial model of care. Administrative computer data were then used to evaluate effects on medical center workload. Statistical analyses included analysis of variance, analysis of covariance, chi-square, and logistic regression.

RESULTS

For practice-based comparisons, complete data were available for 1,262 veterans in 1992 and 1,373 in 1993. For visit-based comparisons, complete data were available for 1,407 veterans in 1992 and 643 in 1993. Results included statistically significant improvements in continuity of care and detection of depression as well as increased rates of preventive care counseling (smoking and exercise). The proportion of veterans reporting being seen by physicians increased, as did the proportion of patients seen for check-ups rather than for acute problems. Fewer patients were seen in subspecialty clinics than in general medicine clinics. Patient satisfaction increased, hospitalizations decreased, and death rates decreased. Alcohol counseling and access to care for acute symptoms declined. Workload shifted from subspecialists to generalists and from inpatient care to outpatient care.

CONCLUSION

The institutional reorganization toward primary and ambulatory care succeeded in substantially improving the quality of ambulatory care, reflecting improvements in the system of care and of health care provider training in ambulatory care.

Bacteriostatic and bactericidal activities of benzoxazinorifamycin KRM-1648 against Mycobacterium tuberculosis and Mycobacterium avium in human macrophages

Inhibitory and bactericidal activities of KRM-1648 were determined against Mycobacterium tuberculosis and M. avium residing in human monocyte-derived macrophages and extracellular M. tuberculosis and M. avium. MICs and MBCs of KRM-1648 against intracellular and extracellular bacteria were substantially lower than those of rifampin. The MICs and MBCs of either drug against the intracellular bacteria were only twofold lower than or equal to the values found for extracellular bacteria. The prolonged effect of KRM-1648 found in this study is probably associated with high ratios of intracellular accumulation, which were 50- to 100-fold higher than that found for rifampin. Further studies on intracellular distribution of KRM-1648 and on the sites of actual interaction between the drug and bacteria residing in macrophages are necessary, as well as evaluation of combined effects of KRM-1648 with other drugs in long-term macrophage culture experiments.

Sucralfate gel versus placebo in patients with non-erosive gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease, a term used to refer to chest symptoms that result from reflux of gastric acid into the oesophagus, occur at least daily in 7% and every 3 days in 33% of the population.

METHODS

One hundred and forty-one patients with moderate to severe gastro-oesophageal reflux symptoms occurring at least three times per week (but no oesophageal erosions or ulcers at endoscopy) were treated in this randomized, double-blind, placebo-controlled study at six trial centres. Treatment was given for 6 weeks and consisted of daily doses of either 1 g sucralfate gel b.d. or placebo. The evaluation of efficacy was based on data of 139 patients.

RESULTS

The responder rate at Day 42 was statistically significantly higher for the patients treated with sucralfate (71%) than for the placebo patients (29%) (P < 0.0001, Fisher's exact test). The overall response of the non-ulcer dyspepsia and gastro-oesophageal reflux disease symptoms was better for sucralfate gel than for placebo with 45% of patients treated with sucralfate gel being considered as having a 'good' or 'excellent' overall response compared with 22% of the patients who received placebo (P < 0.0001, Wilcoxon test). Only a few adverse experiences were reported by 10% of sucralfate patients and 7% of placebo patients.

CONCLUSION

In this trial, we demonstrated a statistically significant superiority of sucralfate gel at a dosage of 1 g b.d. compared to placebo in the treatment of patients with gastro-oesophageal reflux disease. Sucralfate gel was well tolerated.

gamma-Aminobutyric acid concentrations in the cerebrospinal fluid of newborn infants determined by high performance liquid chromatography

gamma-Aminobutyric acid (GABA), a major inhibitory amino acid, has a central role in cardiorespiratory regulation. Its measurement in the cerebrospinal fluid (CSF) complements the study of neurotransmission systems. Forty-one children were studied (postnatal age < 1 year). For each child, date of birth, date of sampling and current treatments were collated and their postnatal (days) and postconception (weeks) ages were calculated. CSF samples were studied using reverse phase high performance liquid chromatography (HPLC) with o-phthaldialdehyde derivation and spectro-fluorimetric measurement. A clear increase in levels of GABA was observed around 41 weeks postconception, followed by a progressive decrease, with levels stabilizing after 57 weeks postconception. GABA-regulated neuromodulation therefore appears to be mature at 41 weeks postconception and not at birth. The data could be used in further studies investigating amino acid metabolism in relation to brain function in various neurological disorders.

The history of psychiatry: an opportunity for self-reflection and interdisciplinary dialogue. Essay review

"Can you recommend a good one volume history of psychiatry?" I am often asked this question, being a psychiatric and psychoanalytic clinician who has also been deeply involved in the history of psychiatry, as a writer and as a teacher. "Single authored or multiple authored?" I ask in return and explain that if single authored the answer is no; if multiple authored I respond, "You have to await the publication of the huge encyclopedic volume(s), edited by John Gach and Edwin Wallace, sometime in the next few years. That 'definitive' work will not be definitive for very long; neither will it be inexpensive nor light reading, either in heft or in style." "What about Zilboorg's History of Medical Psychology?-I remember it as readable, portable, and quotable," my student or colleague continues. To that I reply, "Definitely worth reading, but you will have to do a lot of other reading to fill in the important omissions, to correct the errors of fact and interpretation, and to understand the author's unquestioned assumptions and biases." "Erwin Ackernecht's Short History of Psychiatry?" "Good book, amazing what's packed into it, but it really is short. If you read German very well, there is Der Wahnsinn by Leibbrand and Wettley, which would serve you better, but that is a huge book with small print, and for that too you would have to do a lot of extra reading to fill in gaps and to understand their biases."

Effects of a temperature increase on oxygen consumption of yellow freshwater eels exposed to high hydrostatic pressure

Oxygen consumption was measured in yellow freshwater eels, Anguilla anguilla, during exposure to a hydrostatic pressure (HP) of 101 atmosphere absolute (ATA) for 3 h, either with or without a 5 degrees C increase in water temperature. It was found that concomitant increases in temperature and pressure resulted in an increase in oxygen consumption that was lower than when pressure alone was increased. When eels were acclimated to HP for 21 days and then submitted to a temperature increase of 5 degrees C, this induced a significant increase in oxygen consumption but only during the first hour. It is therefore concluded that raising the water temperature during the first hours under pressure could counterbalance the pressure effects on membrane fluidity in a thermodynamic manner and thus help shallow-water fish acclimate to high pressure. In contrast, when acclimation processes are ended, the temperature effect disappears within 1 h.

Tumor cell-induced platelet aggregation in vitro by human pancreatic cancer cell lines

BACKGROUND

Tumor cell-induced platelet aggregation (TCIPA) is considered to be a critical step in hematogenous metastasis.

METHODS

TCIPA was studied in vitro in six human pancreatic carcinoma cell lines (PC 3, PC 44, AsPC1, BxPC3, Capan2, Panc1).

RESULTS

Whereas all cell lines induced aggregation of washed platelets in the presence of minimal amounts of platelet-poor plasma, five cell lines also induced aggregation of platelets in platelet-rich plasma. The thrombin-antagonist hirudin inhibited TCIPA in all cell lines indicating that TCIPA is thrombin-dependent. Since pretreatment of tumor cells with phospholipase A2 or C inhibited TCIPA, the thrombin-generating activity might be confined to the tumor cell surface. Further support for a prothrombinase activity was provided by the observation that all cell lines were able to induce the aggregation of washed platelets after addition of purified coagulation factors II and V.

CONCLUSIONS

Pancreatic carcinoma cells are able to induce platelet aggregation via activation of thrombin. This might support metastasis in pancreatic cancer and possibly explain the incidence of thrombosis in this tumor.

Comparison of activities of rifapentine and rifampin against Mycobacterium tuberculosis residing in human macrophages

The activities of rifapentine and rifampin against Mycobacterium tuberculosis residing in human monocyte-derived macrophages were determined. The MICs and MBCs of rifapentine for intracellular bacteria were two- to fourfold lower than those of rifampin. For extracellular bacteria, this difference was less noticeable. Nevertheless, the more favorable pharmacokinetics of rifapentine over rifampin was addressed in other experimental models. These models showed substantial differences after short pulsed exposures of the infected macrophages to the drugs and when the infected macrophages were exposed to changing drug concentrations that imitated the pharmacokinetic curves observed in blood. Once-a-week exposures to rifapentine concentrations equivalent to those attained in blood after one 600-mg dose resulted during the first week in a dramatic decline in the number of bacteria, and this decline was maintained at a minimal level for a period of four weeks. The results of this study have shown the suitability of rifapentine for intermittent-treatment regimens. The prolonged effect of rifapentine found in this study may be associated with high ratios of intracellular accumulation, which were four- to fivefold higher than those found for rifampin. Further studies on the intracellular distribution of rifamycins and on the sites of actual interaction between the drugs and bacteria residing in macrophages are necessary.

Increasing the impact of quality improvement on health: an expert panel method for setting institutional priorities

BACKGROUND

Successful implementation of modern ongoing quality improvement (QI) methods requires investment of institutional resources, but can produce significant improvements in medical care. A health care organization's goals and objectives for improving care are expressed in strategic plan documents, which could provide a framework for planning quality improvement initiatives. However, institutional strategic planning processes are often not well linked to QI staff and resources. We developed the Quality Action Program (QAP) to connect QI to strategic planning.

HISTORY

In 1991, Sepulveda VHAMC implemented a major primary care initiative, documented in a comprehensive strategic plan. The QAP was developed to enable the initiative to be evaluated within a QI context. THREE-ROUND EXPERT PANEL PROCESS: To carry out the QAP, members of an institution's quality council engage in a structured consensus process. The first round involves reading educational materials and filling out a quality action survey the second round includes participation in an expert panel meeting, and the third round involves making final priority rankings. EIGHT-STEP QAP IMPLEMENTATION PLAN: QI staff carry out activities to prepare for and carry out the three-round expert panel process.

RESULTS

QAP induced significant institutional QI activity directed toward achieving the top-ranked QI criterion--ensuring continuity of care. Continuity of care improved significantly over time between the pre- and post-QAP periods.

CONCLUSIONS

Expert panel methods can be used to link strategic plan goals and objectives to QI efforts.

Strategy to detect and identify Bartonella species in routine clinical laboratory yields Bartonella henselae from human immunodeficiency virus-positive patient and unique Bartonella strain from his cat

We wished to develop a cost-effective, rapid strategy to detect and identify Bartonella species in the clinical laboratory and to determine the prevalence of Bartonella infection in the Houston veteran population. Bartonella colonies were identified by colony morphology, Gram stain, RapID ANA, repetitive extragenic palindromic-PCR (REP-PCR) and whole-cell fatty acid (CFA) analysis, and these methods were compared for their usefulness. A new test order for "Rochalimaea culture" (the genus Bartonella was previously known as the genus Rochalimaea) was instituted, and in addition, all blood specimens submitted for fungal culture (obtained in an isolator tube) were processed for Bartonella culture. Over a 16-month period we isolated Bartonella henselae from only 0.4% (2 of 533) of total cultures but from 1% (2 of 204) of human immunodeficiency virus-positive patients. After sufficient growth, identification of the Bartonella isolates to the species level could be obtained in 2 days. The REP-PCR allowed discrimination of all known species, whereas CFA analysis distinguished all except B. henselae and Bartonella quintana. The RapID ANA results failed to differentiate between B. henselae and B. quintana, and results for other species differed by only one or two tests. Blood obtained from a kitten which had been introduced into the household of one patient 2 months before the onset of fever yielded a Bartonella strain which was shown to be different from the strain from the patient and distinct from other Bartonella species by a combination of REP-PCR, CFA, and growth characteristics. Subsequent analysis of the citrate synthase gene sequence showed only an 86% similarity with any of the other known Bartonella species, suggesting that this isolate represents a distinct, previously uncharacterized species of Bartonella.

[Effects of hydrostatic pressure on malondialdehyde (MDA) determination in brain from yellow freshwater eels]

Malondialdehyde (MDA) content in a tissue can be an indicator of lipoperoxidation and thus of membrane alteration. MDA concentrations have been measured in the brain of yellow freshwater eels (Anguilla anguilla) submitted to 1.51 or 101 ATA of hydrostatic pressure. Exposure to pressure was performed for 6 h at constant water temperature and in normoxic conditions. The results thus obtained show a significant increase (P < 0.05 or better) of MDA brain concentrations at 51 ATA (+ 124%) and 101 ATA (+ 290%). These results mean that hydrostatic pressure is able to activate lipoperoxidation and can alter membrane functions together with the decrease in membrane fluidity it induces. Such a membrane alteration can explain, at least in part, the excitation periods which are observed during and after animal compression.

The prognostic significance of arterial blood pressure in liver cirrhosis

A decrease of the blood pressure (BP) due to the changes in the regulatory mechanisms of blood pressures homeostasis is frequently observed in cirrhosis. The present work studied the blood pressure profile of the cirrhotic patients and estimated the influence it might have on the survival prognosis at one year. A lower mean blood pressure: 8.25 +/- 1.5 cm Hg is observed versus a control group: 9.8 + 2.0 cm Hg (p < 0.001). The decrease is due to the patients with severe liver impairment (Child class C). The survival is poor in cirrhosis with hypotension (systolic blood pressure < 9 cm Hg): 75 +/- 10%, than in patients with systolic blood pressure between 9 and 11 cm Hg (survival rate 91 +/- 6%) and patients with systolic blood pressure over 11 cm Hg (survival rate 88 +/- 6%) (p < 0.001).

Methods for determining concentrations of antimicrobial agents in human monocytes

Human monocytes can be derived from the leukocyte-rich by-product of donors' blood available after platelet separation. Large volumes of the monocyte samples obtained from this product provided an opportunity to conduct experiments with relatively high concentrations of the antimicrobial agents sufficient for their detection in bioassays, thus avoiding the necessity of working with the radiolabelled drugs. Washing of the cells after their exposure to the drug may lead to an extraction of the tested agent from the cell, especially if it is a substance of low molecular weight. In our experiments we excluded the washing step, and separated the monocytes from the extracellular medium by velocity gradient centrifugation. In experiments with two rifamycins, the cell pellet as well as the extracellular fluid were subjected to a bioassay using Micrococcus luteus as a target organism. The method showed good reproducibility and consistency in results obtained.

[Protective effect of omeprazole against low-dose acetylsalicylic acid. Endoscopic controlled double-blind study in healthy subjects]

Protective Effects of Omeprazole against Low-dose Acetylsalicylic Acid/An endoscopic controlled double-blind study in healthy volunteers. In a randomized double-blind parallel study the gastroduodenal tolerability of 300 mg acetylsalicylic acid (CAS 50-78-2, ASA) daily (8 p.m.) has been evaluated in the presence of 20 mg and 40 mg omeprazole (CAS 73590-58-6) daily (8 p.m.) or placebo in 36 healthy volunteers using upper GI-endoscopy. The treatment periods lasted 14 days. Endoscopic controls were performed at entry and repeated at day 14. At entry the mean endoscopic score averaged 0.9 +/- 0.08 in the ASA/placebo (n = 12), the ASA/omeprazole 20 mg (n = 12) and the ASA/omeprazole 40 mg group (n = 12). The median values were 1.0. In the placebo experiments 300 mg ASA daily induced marked gastroduodenal lesions at day 14 (12.4 +/- 1.7). The median value was 10.0. Concomitant administration of 20 mg omeprazole daily afforded significant protection against 300 mg ASA daily on day 14 (2.9 +/- 0.9) (p < 0.0005 vs. ASA/placebo). 300 mg ASA + 40 mg omeprazole daily reduced the damaging score to 1.8 +/- 0.5 (p < 0.00002 vs. ASA/placebo). The median values in the ASA/omeprazole 20 mg and in the ASA/omeprazole 40 mg group were 1.0. The difference in the damaging score between ASA/omeprazole 20 mg and ASA/omeprazole 40 mg after 14 days did not reach statistical significance. Our data suggest that coadministration of 20 mg omeprazole daily reduces almost completely gastroduodenal lesions evoked by 300 mg ASA.

Effect of gastrin receptor blockade on gastrin and histidine decarboxylase gene expression in rats during achlorhydria

BACKGROUND

Gastrin stimulates histidine decarboxylase (HDC) activity and proliferation of enterochromaffin-like (ECL) cells. Furthermore, it has been suggested that gastrin controls HDC gene expression. We therefore analysed the effect of gastrin receptor blockade by PD 136 450 (CAM 1189) on HDC gene expression. The influence of PD 136 450 on gastrin, somatostatin, and chromogranin A was also evaluated.

METHODS

Gene expression of HDC, gastrin, somatostatin, and chromogranin A (CgA) was analysed by Northern blot analyses after 14 days' application of the proton pump inhibitor BY 308 and/or the gastrin/cholecystokinin B receptor antagonist PD 136 450.

RESULTS

PD 136 450 had no significant effect on gastrin mRNA or somatostatin mRNA in controls and during proton pump inhibition. BY 308 treatment resulted in a marked induction of HDC and CgA mRNA, whereas concomitant PD 136 450 in a concentration previously shown to suppress maximal pentagastrin-induced gastric acid secretion and to prevent BY 308-induced ECL cell proliferation did not result in significant alteration. PD 136 450 increased HDC significantly and CgA mRNA to a lesser extent in normogastrinaemic rats, whereas previous work showed a decreased ECL cell labelling index.

CONCLUSIONS

These data suggest that there are independent regulatory pathways for ECL cell proliferation and gene expression. Other factors besides gastrin may act through PD 136 450-insensitive pathways to control HDC and CgA gene expression.

[Protective effects of ranitidine in ibuprofen gastroduodenopathy. An endoscopic controlled double blind study]

Protective Effect of Ranitidine in Ibuprofen Gastroduodenopathy/An endoscopically controlled double-blind study in healthy volunteers. In a randomized parallel double-blind study the gastroduodenal effects of 600 mg ibuprofen racemate (CAS 15687-27-1) tid in the presence of 150 mg ranitidine (CAS 66357-35-5, Sostril) bid or placebo was evaluated in 32 healthy volunteers undergoing upper gastrointestinal endoscopy. Drugs were taken during a period of 7 days. Endoscopic controls were performed at entry and repeated after 7 days of treatment. A damaging score was used to asses the lesions. At entry both groups showed comparable mucosal damages. The median values under ibuprofen/placebo were 1 (range 0-1) and under ibuprofen/ranitidine 1 (range 0-2). After 7 days of treatment the median lesions score increased under ibuprofen/placebo to 8 (range 1-20) whereas corresponding values in the ibuprofen/ranitidine group were constant at 1 (range 1-9). The differences between both groups were statistically significant (p < 0.05). Our data underline the protective effect of ranitidine 150 mg bid against ibuprofen both on the stomach as well as on the duodenum.

[Status of ranitidine in eradication of Helicobacter pylori]

Permanent removal of Helicobacter pylori leads to a dramatic drop in the recurrence rate of peptic ulcers. The NIH Consensus Conference recommends that Hp-positive patients with duodenal or gastric ulcer should undergo eradication treatment. To date, however, there is no consensus on what constitutes optimal eradication treatment. Presently available therapy may be triple (bismuth plus two antibiotics), dual (acid inhibition and one antibiotic) or modified triple therapy (acid inhibition and two antibiotics). Among numerous treatment proposals, results gained with the H2 blocker ranitidine stand out, on account of the double-blind nature of the studies and the adequate number of cases involved. With modified triple therapy (300 mg ranitidine nocte and 3 times 750 mg amoxicillin daily) eradication rates ranging from 85 to 90%, and with dual therapy (600 mg ranitidine and 2 g amoxicillin daily) 60 to 65%, are obtained.

Caffeine modulates Ca2+ receptor activation in isolated rat osteoclasts and induces intracellular Ca2+ release

A ryanodine-sensitive pathway is involved in intracellular Ca2+ release in response to activation of the osteoclast cell surface Ca2+ receptor. We now report that the ryanodine-receptor modulator, caffeine itself released intracellularly stored Ca2+ and, strongly inhibited Ca2+ release triggered in response to Ca(2+)-receptor activation by Ni2+, a surrogate cation agonist. Caffeine yielded a bell-shaped concentration-response curve (0.005-2 mM) and displayed use-dependent inactivation. Furthermore, responses to caffeine were abolished on prior application of Ni2+ (5 mM). Subthreshold (0.005 mM) caffeine concentrations abolished Ni(2+)-induced elevations in the cytosolic Ca2+ concentration ([Ca2+]). However, in a Ca(2+)-free, ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid-containing solution (extracellular [Ca2+] < 10 nM), caffeine (0.5 mM) neither elevated [Ca2+] nor inhibited the response to Ni2+. Finally, when caffeine was applied to intercept the plateau phase of the cytosolic Ca2+ signal triggered by extracellular Ca2+ elevation (10 mM), a rapid but reversible inactivation followed. These studies strongly indicate the existence of a caffeine-sensitive mechanism for the release of intracellularly stored Ca2+ in the osteoclast.

The alpha 6-integrin receptor in pancreatic carcinoma

BACKGROUND/AIMS

The alpha 6-containing integrin was suggested to be involved in the process of tumor invasion and metastasis. Therefore, the aim of the study was to investigate the expression and function of this adhesion receptor in pancreatic carcinoma.

METHODS

Integrin expression was investigated in pancreatic tissue and tumor cell lines using immunohistochemistry. Radioimmunoprecipitation was used to determine the complex composition of alpha 6. To analyze the function of the alpha 6-containing integrin in pancreatic cancer, in vitro adhesion, migration, and invasion experiments were performed.

RESULTS

The alpha 6-containing integrin was differentially expressed in normal pancreas and pancreatic carcinoma. Immunoprecipitation of different pancreatic carcinoma cell lines showed that alpha 6 was expressed together with the beta 4 subunit as alpha 6 beta 4 complex. However, adhesion of pancreatic cancer cells to laminin could be inhibited with anti-alpha 6 and anti-beta 1 integrin antibodies but not by anti-beta 4 integrin antibody. Migration of the cells through laminin was almost completely inhibited by anti-beta 1 antibody but not by other anti-integrin antibodies. Tumor cell invasion through a reconstituted basement membrane was only slightly inhibited by anti-alpha 6 antibody. In contrast, a marked inhibition was observed using anti-beta 1 antibodies, anti-alpha 2-anti-alpha 5 antibodies, and RGDS.

CONCLUSIONS

The alpha 6-containing integrin is a laminin adhesion receptor in pancreatic carcinoma cells, possibly involved in tumor invasion through the basement membrane.

Molecular cloning of major and minor allergens of Alternaria alternata and Cladosporium herbarum

The two moulds, Alternaria alternata and Cladosporium herbarum, are recognized as major causes of fungal allergies. Cloning, sequencing and heterologous expression of the allergens of the two moulds is a necessary step in understanding fungal allergy and in the development of new and improved methods of diagnosis and therapy. The seven new mould allergens presented here represent four new allergen proteins: aldehyde dehydrogenase (ALDH), enolase, YCP4 (previously found as a Saccharomyces cerevisiae protein of unknown function), and the acidic ribosomal protein, P2. Three of them (ALDH, YCP4 and P2) were found to be allergens in both fungi, Alternaria and Cladosporium. All allergens found so far are cytoplasmic proteins and are rather well conserved in evolution even when comparing distant species. Most of the allergens have "household" functions (ALDH, enolase). One allergen (P2) is a homolog of a very highly conserved human lupus erythematodes (LE) antigen. None of the fungal allergens is clearly related to other known non-fungal allergens.

Effect of membrane potential on surface Ca2+ receptor activation in rat osteoclasts

Osteoclasts are known to possess a divalent cation-sensitive receptor, the Ca2+ receptor (CaR). The latter monitors changes in the local Ca2+ concentration generated as a result of hydroxyapatite dissolution. CaR activation elevates cytosolic [Ca2+] and thereby inhibits osteoclastic bone resorption. Recent studies have used Ni2+ as a surrogate CaR agonist to elicit changes in cytosolic [Ca2+]. This article examines the effects of membrane potential changes on the kinetics of the cytosolic [Ca2+] signal resulting from such Ni(2+)-induced CaR activation. Membrane potential was altered through variations in the extracellular [K] in combination with applications of the K+ ionophore, valinomycin. Membrane potential changes were confirmed by independent electrophysiological patch clamp studies of whole osteoclasts. The application of valinomycin produced a distinct, sustained elevation of cytosolic [Ca2+] in single fura 2-loaded cells, a "primary" response. This response was independent of valinomycin concentration (between 5 nM to 5 microM) and persisted in Ca(2+)-free, EGTA-containing solutions. It also persisted both in high (105 mM) and low (5 mM) extracellular [K+]. A gradual "secondary" elevation of cytosolic [Ca2+] then followed with the continued application of valinomycin, but this was eliminated by sequestering the extracellular [Ca2+] or by increasing extracellular [K+] from 5 to 105 mM. In a separate set of experiments, the presence of 5 microM [valinomycin]-([K+] = 5 mM) prolonged the cytosolic [Ca2+] signal elicited by 50 microM-[Ni2+] application. These prolonged kinetics persisted in low extracellular [Ca2+] (zero-added Ca2+), but reverted to a rapid time-course in the presence of 105 mM-[K+] or at higher [Ni2+] (500 microM and 5 mM). The experiments thus indicate that membrane voltage modifies the kinetics of CaR activation by Ni2+ and therefore suggests that the CaR is an integral protein in the osteoclast surface membrane.

[Comparison of the protective effects of roxatidine and misoprostol on diclofenac gastroduodenal pathology. An endoscopic, controlled study of volunteers]

For prophylaxis of gastroduodenal lesions induced by non-steroidal antirheumatic drugs (NSAID) acid-lowering as well as mucosa protective substances are used. Direct comparison of both therapeutic regimens are lacking. In randomized parallel studies the gastroduodenal tolerability of 100 mg diclofenac daily in slow-release form was evaluated in the presence and absence of 150 mg roxatidine (CAS 78273-80-0) daily as well as in the presence of 75 mg bid roxatidine or 200 micrograms bid misoprostol (CAS 59122-46-2). The drugs were taken over a period of 14 days. Endoscopic controls were performed at entry, as well as after 14 days of treatment. A quantitative damaging score was used. Study A: Both treatment groups (n = 20) had at entry comparable mucosal damages: placebo/diclofenac: 0.9 +/- 0.1 (+/- SEM), roxatidine/diclofenac: 0.9 +/- 0.1; after 14 days of treatment the score increased in the diclofenac/placebo group to 7.6 +/- 1.9 and, in the corresponding diclofenac/roxatidine group, only to 2.1 +/- 0.9. The difference between the two treatment groups after 14 days was significant (p < 0.05). Study B: Both treatment groups (n = 24) had comparable mucosal damages at entry: diclofenac/roxatidine: 0.9 +/- 0.1, diclofenac/misoprostol: 0.8 +/- 0.1. Following 14 days treatment with 100 mg diclofenac daily the damaging score in both group rose to comparable levels: roxatidine group 2.1 +/- 0.7 and misoprostol group 2.0 +/- 0.4 (n.s.). The data suggest that for prophylaxis of NSAID-induced gastroduodenal lesions substances with different mechanism of action can be used. The findings underline the complex way by which NSAID can damage the mucosa of the upper gastrointestinal tract.

Ranitidine in the treatment of non-ulcer dyspepsia. A placebo-controlled study in the Federal Republic of Germany

The trial randomly assigned 652 patients with non-ulcer dyspepsia (NUD), defined as chronic or recurrent complaints of acid-related (heartburn, acid regurgitation, epigastric pain) and non-acid related (fullness/vomiting, nausea) symptoms and with no evidence of organic disease, to treatment for 4 weeks with 150 mg of ranitidine (Zantic, CAS 66357-59-3) twice a day, or placebo, according to a double-blind design. The presence and duration of all dyspeptic symptoms were recorded by interviews at the beginning and after 2 and 4 weeks of treatment as well as by diaries. The complete disappearance of all dyspeptic symptoms after 4 weeks in the placebo group was 36%; ranitidine treatment resulted in a significant improvement after 4 weeks (p < 0.05). The effect of ranitidine was slightly more pronounced in acid-related than in non-acid-related symptoms. We conclude that suppression of gastric acid secretion is of clinical value in NUD patients, especially in those suffering from epigastric pain, acid regurgitation and heartburn.

Cytogenetic and fluorescence in situ hybridization studies on sporadic and hereditary tumors associated with von Hippel-Lindau syndrome (VHL)

We performed cytogenetic and fluorescence in situ hybridization (FISH) studies on 29 sporadic or familial tumors associated with von Hippel-Lindau [correction of Landau] disease. Four of five renal cell carcinomas with detectable alterations showed clones with chromosome 3 alterations. These changes led to loss of genetic material visible with cytogenetic resolution: either an unbalanced translocation involving 3p or loss of a whole homolog 3, resulting in monosomy of 3p. We have previously mapped the VHL gene to chromosomal region 3p25-p26. We applied FISH using the single copy probes cA233 and cA479, sequences close to the VHL gene, in a search for submicroscopic deletions of 3p. Use of FISH with differentially labeled probes indicated cA479 to be distal to cA233, but both were located within bands 3p25-26. FISH with single copy probes for interphase cytogenetics detected four subclones with deletions in the VHL region in 8/22 tumors, including four tumors which appeared cytogenetically normal. FISH proved to be a powerful tool in tumor genetic studies, especially helpful in detecting tumor subclones in benign and slowly growing tumors.

Activation of gastrin gene transcription in islet cells by a RAP1-like cis-acting promoter element

Gastrin transcription in islet cells is activated by a cis-regulatory sequence containing a binding site for the yeast transcription factor RAP1. The DNA-protein interactions between RAP1 protein and the gastrin DNA element determined by methylation interference assays are identical to those of RAP1 and yeast genes. Point mutations in the gastrin RAP1 binding site, which abolished RAP1 binding, decreased transcriptional activation by this sequence. Islet cells revealed a DNA binding protein with RAP1-like binding specificity. These findings support the conclusion that gastrin transcription is activated in mammalian cells by a RAP1-like transcription factor.

Fact and fantasy in the history of Freud's views on incest and seduction

This article surveys the history of Freud's attitudes and theories about the etiologic role of actual incest and seduction and neurosis. It also surveys the debate in historical writing on that topic, much of which oversimplifies complex and contradictory data. Here is an instance in which history is being written and used as part of current debates and polemics, principally to either monolithically defend or attack Freud. This article argues that Freud's motives for downplaying the etiologic role of seduction in the neuroses were complex, did not involve cowardice, and need to be understood both in terms of internal developments in Freud's thinking as well as in terms of relevant external (for example, historical) factors.

[Circadian aspects of acetylsalicylic acid induced injury and protective effect of ranitidine on the the upper gastrointestinal tract]

Circadian Aspects of Acetylsalicylic Acid Induced Injury and Protective Effect of Ranitidine on the Upper Gastrointestinal Tract. In a randomised parallel double-blind study the gastric and duodenal effects of 300 mg acetylsalicylic acid (ASA, CAS 50-78-2) daily in the presence and absence of 150 mg ranitidine (Zantic, CAS 66357-35-5) daily was evaluated in 32 healthy volunteers undergoing upper gastrointestinal endoscopy. Drugs were taken over a period of 7 days either at 8 a.m. (n = 16) or at 8 p.m. (n = 16). Endoscopic controls were performed at entry and repeated after 7 days of treatment. At entry both groups showed comparable mucosal damages: 8 a.m. group: ASA/placebo 0.8 +/- 0.1 (stomach) and 0.1 +/- 0.1 (duodenum): ASA/ranitidine 1.0 +/- 0.0 (stomach) and 0.07 +/- 0.06 (duodenum). 8 p.m. group: ASA/placebo 0.9 +/- 0.06 (stomach) and 0.1 +/- 0.09 (duodenum). ASA/ranitidine 0.8 +/- 0.08 (stomach) and 0.07 +/- 0.06 (duodenum). After 7 days of treatment the lesions score increased in the ASA/Placebo group in the 8 a.m. group to 9.1 +/- 1.1 (stomach) and 2.7 +/- 1.0 (duodenum), and in the 8 p.m. group to 10.9 +/- 1.1 (stomach) and to 3.9 +/- 0.9 duodenum). The corresponding values in the ASA/ranitidine group were 2.6 +/- 0.8 (stomach) and 0.2 +/- 0.08 (duodenum) (8 a.m.) and 4.8 +/- 0.8 (stomach) and 0.3 +/- 0.1 (duodenum) (8 p.m.). There was no statistical difference between the morning- and the evening dose of ASA. In addition, ranitidine protection was also time-independent.(ABSTRACT TRUNCATED AT 250 WORDS)

The value of the historical perspective to contemporary psychoanalysis: Freud's 'seduction hypothesis'

In this paper the authors re-examine the development of Freud's ideas on seduction, with a special focus on the evidence which Freud presented and upon which he relied as he attempted to confirm these ideas. Through this re-examination Freud's struggle with seductiveness, both in relation to his patients and in relation to his theories, comes to the fore. While the wish to be with the other through exerting an influence over him or her is perverted in the act of sexual seduction, it is, nevertheless, a force that must be recognised and contended with in other creative interchanges, including the analytic one. In studying Freud's struggle with this force, there is attained a better appreciation of the humanness, including the inevitable human limitations, of Freud and his thinking that rest at the foundation of psychoanalysis. This study thus has clear implications for the history of psychoanalysis, but, more importantly, it reveals the value for contemporary psychoanalysis in recognising this history.

Effects of ibuprofen lysinate and acetylsalicylic acid on gastric and duodenal mucosa. Randomized single-blind placebo-controlled endoscopic study in healthy volunteers

Acetylsalicylic acid (ASA, CAS 50-78-2) and ibuprofen (IB) are commonly used over-the-counter drugs for short-term treatment of pain of different origin. Ibuprofen lysinate (IBL, CAS 57469-76-8) is a water soluble form of ibuprofen for rapid absorption. This single blind, randomized, controlled study compared the incidence and severity of irritation of gastric and duodenal mucosa in normal healthy subjects (n = 45) following administration of IBL (Dolormin) 800 mg/d, ASA 2000 mg/d or placebo for 3 consecutive days. Gastric and duodenal mucosal injury were assessed endoscopically using a severity scale of 0-4 for mucosal erosions and mucosal hemorrhages. Mean gastric hemorrhage and erosion scores for ASA and IBL were significantly higher than those for placebo. In addition, ASA was found to be significantly more irritating to gastric mucosa than IBL, in both the incidence and severity of gastric erosions. No duodenal hemorrhages were detected in this study. The incidence of duodenal erosions was significantly higher in the ASA group (64%) than in both the IBL (6%) and placebo groups (0%) which were not significantly different. Only one subject (in the placebo group) reported an adverse experience (mild headache) during the study. The data suggest that both active treatments are more injurious to the gastric mucosa than placebo when given for 3 days to normal healthy volunteers, but that IBL 800 mg/d is significantly less injurious to the gastric and duodenal mucosa than ASA 2000 mg/d.

Self-stereotyping and social context: the effects of relative in-group size and in-group status

In 2 laboratory experiments, the tendency to stereotype oneself in terms of one's group membership as a function of the social context was examined. Experiment 1 examined the effects of relative in-group size on self-stereotyping. The results confirmed the prediction that minority members are more likely than majority members to stereotype themselves. Experiment 2 examined the interactive impact of relative in-group size and in-group status. As predicted, a high (relative to a low) status of the in-group increased self-stereotyping primarily for minority members, but not for majority members. Moreover, analyses of the differences in perceived in-group and out-group homogeneity suggest that the in-group homogeneity effect should also be interpreted in terms of self-stereotyping processes. Finally, the interplay between cognitive and motivational determinants of self-stereotyping is discussed as well as a possible distinction between self-stereotyping effects on individual level versus group level self-representations.

Frequent alterations of the tumor suppressor genes p53 and DCC in human pancreatic carcinoma

BACKGROUND/AIMS

The pathogenesis of pancreatic cancer is poorly understood. The multigenetic nature of carcinogenesis has been best documented in colon cancer. The relevance of this model was suggested for other epithelial tumors. Only advanced stages of pancreatic cancer are usually detected because of late diagnosis. Analysis of accumulated, diverse genetic changes could allow further understanding of putative mechanisms involved in tumor development. Activated c-Ki-ras oncogene has been shown to be a frequent event. However, additional alterations of tumor suppressor genes are expected. Therefore, concomitant genetic changes of p53 and deleted in colon carcinoma (DCC) in pancreatic carcinoma cell lines and primary tumors were analyzed.

METHODS

p53 protein and transcript expression were revealed by immunocytochemistry and immunohistochemistry, immunoassay, and Northern blot analysis. p53 mutations were identified by sequence analysis. DCC expression was investigated by reverse-transcription polymerase chain reaction.

RESULTS

p53 overexpression was observed in 9 of 12 cell lines. p53 point mutations were confirmed in seven cell lines overexpressing p53. The majority of cell lines showed concomitant p53 and DCC alterations. Four of 6 primary tumors overexpressing p53 also showed loss of DCC expression.

CONCLUSIONS

p53 and DCC genetic changes are associated with pancreatic cancer and the frequently activated c-Ki-ras oncogene. Therefore, the multihit model of carcinogenesis could prove relevant for pancreatic cancer.