Use of representational difference analysis to study the effect of TGFB on the expression profile of a pancreatic cancer cell line

It has been shown that TGFBs, their receptors, or downstream targets show genetic alterations in pancreatic cancer. This study was designed to identify transcriptional alterations induced by prolonged treatment of pancreatic cancer cell lines with TGFB. The TGFB-responsive PANC-1 cell line was treated with 10-ng/ml TGFB1 for 24 hr. cDNA representational difference analysis was used to generate subtracted hybridization probes enriched for TGFB regulated genes. These probes were hybridized on gridded arrays of cDNA clones containing genes differentially expressed in pancreatic cancer. Twenty-seven distinct cDNA clones were shown to be TGFB target genes. Eleven genes were upregulated by TGFB and were associated with extracellular matrix composition and formation, including genes usually transcribed by cells of mesenchymal origin only. Transcript levels of 16 genes were downregulated by TGFB and could mainly be classified into markers of epithelial differentiation and genes involved in the transcriptional and translational machinery. In conclusion, a 24-hr treatment of PANC-1 cells with TGFB induced a loss of epithelial and a gain of mesenchymal markers. As in other tumors, this epithelial-mesenchymal transdifferentiation may be of general importance during pancreatic carcinogenesis, and may participate, e.g., in the development of the desmoplastic reaction or the acquisition of an invasive phenotype of pancreatic tumor cells. This study demonstrates the usefulness of cDNA RDA and gridded clone libraries to study the effect of signaling cascades on the expression profile of tumor cells. Similar approaches may be helpful in the context of the genome project for the characterization of novel genes. Genes Chromosomes Cancer 26:70-79, 1999.

Novel technology for detection of genomic and transcriptional alterations in pancreatic cancer

AIM

The present review summarizes our strategies aimed at identifying and characterizing genetic alterations occurring at the transcriptional and chromosomal level in pancreatic cancer.

METHODS

To study transcriptional alterations we have used a number of techniques including modified versions of differential hybridizations and cDNA-RDA (representational difference analysis). Comparative genomic hybridization (CGH) was used to study chromosomal aberrations occurring in pancreatic cancer tissues.

RESULTS

The study of transcriptional alterations led to the identification of more than 500 genes with differential expression in pancreatic cancer. The sum of these alterations represented the first expression profile characteristic for pancreatic tumors. The CGH analysis allowed the identification of a number of chromosomal regions containing putative tumor suppressor genes or oncogenes. These regions are presently being characterized at the molecular level. In a first approach the myb-oncogene was identified as the relevant oncogene of an amplification on 6q occurring in up to 10% of pancreatic cancer patients.

CONCLUSIONS

Genes isolated in both approaches represent potential new disease genes for pancreatic cancer and are at present being characterized by individual or serial analysis.

Regulation of cell growth and cyclin D1 expression by the constitutively active FRAP-p70s6K pathway in human pancreatic cancer cells

The FRAP-p70s6K signaling pathway was found to be constitutively phosphorylated/active in MiaPaCa-2 and Panc-1 human pancreatic cancer cells and a pancreatic cancer tissue sample as judged by the retarded electrophoretic mobility of the two major FRAP downstream targets, p70s6K and 4E-BP1. Treatment of cells with rapamycin, a selective FRAP Inhibitor, inhibited basal p70s6K kinase activity and induced dephosphorylation of p70s6K and 4E-BP1. Moreover, rapamycin inhibited DNA synthesis as well as anchorage-dependent and -independent proliferation in MiaPaCa-2 and Panc-1 cells. Finally, rapamycin strikingly inhibited cyclin D1 expression in pancreatic cancer cells. Thus, inhibitors of the constitutively active FRAP-p70s6K pathway may provide a novel therapeutic approach for pancreatic cancer.

Genomic organization and chromosomal mapping of mouse nuclear factor kappa B 2 (NFKB2)

NFKB2 is a member of the NFKB/Rel gene family, which is known to be a pivotal regulator of the acute phase and immune responses. NF-kappaB2 is initially synthesized as a approximately 100 000 Mr protein which needs to be processed in order to bind DNA, either as homodimer or as heterodimer with other members of the NF-kappaB/Rel family. The unprocessed form of NF-kappaB2 acts as an IkappaB-like protein. Therefore, NF-kappaB2 has a dual function. In this report we describe the genomic structure, expression pattern, and chromosomal localization of mouse NFKB2. Genomic clones were isolated, which span the entire gene of approximately 8.5 kilobases (kb) including 1.5 kb of the promoter region. Comparison to its human and avian homologues revealed a strong evolutionary conservation of the gene structure including the exon/intron borders, sequence, and position of the nuclear localization signal, the glycine-hinge region, and the ankyrin repeats. By fluorescence in situ hybridization, mouse NFKB2 was mapped to Chromosome (Chr) MMU 19C3-D2, which is homologous to human Chr 10q24, at which position the human NFKB2 was previously located. NFKB2 is ubiquitously expressed, highest in lymph nodes and thymus, underlining its role in the immune function.

Prevalence of resistance to clarithromycin and its clinical impact on the efficacy of Helicobacter pylori eradication

BACKGROUND

Triple therapy with a proton-pump inhibitor (PPI) in combination with metronidazole and clarithromycin is the method of choice for eradication of Helicobacter pylori. Failures have been primarily blamed on the development of resistance to clarithromycin. The present study investigated the prevalence and clinical significance of resistance to clarithromycin and metronidazole in determining therapeutic success of both triple therapy as a primary eradication method and high-dose dual therapy in non-responders.

METHODS

On the basis of prior therapy, H. pylori-positive patients were assigned to one of two groups in the present prospective study. Group A (n = 93) included patients who had not undergone any prior eradication treatment, whereas group B (n = 15) consisted of patients who had received clarithromycin but in whom eradication had been unsuccessful. All patients underwent endoscopy with biopsy for bacterial culture and resistance studies. Patients in group A were treated with a 7-day regimen of pantoprazole (40 mg twice daily), metronidazole (500 mg twice daily), and clarithromycin (250 mg twice daily), whereas those in group B received omeprazole (40 mg three times a day) and amoxycillin (1000 mg three times a day ) for 14 days. Success of the eradication treatment was ascertained by means of the 13C urea breath test.

RESULTS

In group A resistance to clarithromycin and metronidazole was identified in 3 patients (4.9%) and in 14 patients (22.9%), respectively. Eradication proved successful in 78 of 84 patients (92.6%) followed up. Two of the 3 patients with primary clarithromycin resistance and 1 of the 14 patients with metronidazole resistance did not respond to treatment. In group B isolated or combined resistance to clarithromycin was found in seven patients, whereas another four showed isolated resistance to metronidazole. Eradication proved successful in 10 of 13 controlled patients (76.9%) followed up, and only 2 patients reported severe side effects.

CONCLUSION

Determination of antibiotic resistance before initiating therapy is not necessary, since primary resistance to clarithromycin is rare. The Italian triple therapy remains a highly effective primary therapeutic method. Further, routine determination of resistance in non-responders also seems to be superfluous because high-dose dual therapy is an effective and well-tolerated second-line therapy regardless of the patients' resistance status.

A randomised, double blind, multicentre trial of octreotide in moderate to severe acute pancreatitis

BACKGROUND

The pharmacological inhibition of exocrine pancreatic secretion with the somatostatin analogue octreotide has been advocated as a specific treatment of acute pancreatitis.

AIM

To investigate the efficacy of octreotide in acute pancreatitis in a randomised, placebo controlled trial.

METHODS

302 patients from 32 hospitals, fulfilling the criteria for moderate to severe acute pancreatitis within 96 hours of the onset of symptoms, were randomly assigned to one of three treatment groups: group P (n=103) received placebo, while groups O1 (n=98) and O2 (n=101) received 100 and 200 microg of octreotide, respectively, by subcutaneous injection three times daily for seven days. The primary outcome variable was a score composed of mortality and 15 typical complications of acute pancreatitis.

RESULTS

The three groups were well matched with respect to pretreatment characteristics. An intent to treat analysis of all 302 patients revealed no significant differences among treatment groups with respect to mortality (P: 16%; O1: 15%; O2: 12%), the rate of newly developed complications, the duration of pain, surgical interventions, or the length of the hospital stay. A valid for efficacy analysis (251 patients) also revealed no significant differences.

CONCLUSIONS

This trial shows no benefit of octreotide in the treatment of acute pancreatitis.

Induction of TFF1 gene expression in pancreas overexpressing transforming growth factor alpha

BACKGROUND/AIMS

Chronic pancreatitis is an inflammatory disease of the exocrine pancreas associated with extensive fibrosis, enlarged pancreatic ducts, acinar cell degeneration, and the formation of tubular complexes. The molecular and biochemical alterations associated with these histological changes are not kown. Generally, the new family of TFF peptides (formerly known as P-domain peptides or trefoil factors) is aberrantly expressed during chronic inflammatory diseases of the gastrointestinal tract.

METHODS

Using human pancreatic tissues obtained from patients with chronic pancreatitis and murine pancreatic tissues obtained from transgenic mice overexpressing transforming growth factor alpha (TGF-alpha), the expression and cellular distribution of TFF1 was analysed using northern blot analysis, polymerase chain reaction (PCR), and immunohistochemistry.

RESULTS

In the normal human pancreas, TFF1 was scarce, with only a few ducts exhibiting cytoplasmic TFF1 immunoreactivity. In contrast, human chronic pancreatitis tissue specimens exhibited strong TFF1 immunoreactivity in ductal cells, areas of ductal hyperplasia, and tubular complexes. Semiquantitative PCR analysis of TFF1 mRNA levels showed enhanced expression of TFF1 in the pancreas of patients with chronic pancreatitis. Furthermore, TFF1 mRNA levels were detectable in the pancreas in four of five transgenic mice overexpressing TGF-alpha. In contrast, four of five wild type mice did not exhibit a TFF1 mRNA transcript. In addition, while no specific TFF1 immunoreactivity was present in the pancreas of the wild type mice, ductal epithelial cells and duct-like tubular complexes in the pancreas of the transgenic mice overexpressing TGF-alpha exhibited pronounced TFF1 immunoreactivity.

CONCLUSIONS

Ductal cells and tubular complexes in pancreatic fibrosis express TFF1. As the 5'-flanking region of TFF1 contains an epidermal growth factor responsive enhancer region and the expression of epidermal growth factor and TGF-alpha is enhanced in pancreatic fibrosis, the enhanced expression of TFF1 in pancreatic fibrosis may be mediated by TGF-alpha.

Sympathetic modulation of lipolysis in subcutaneous adipose tissue: effects of gender and energy restriction

To investigate the differences in the regulation of lipolysis between male and female obese subjects in vivo, we used an in situ microdialysis technique before and after 3 weeks of energy restriction. Using this method, we examined glycerol, glucose, and lactate responses after 5 minutes of epinephrine stimulation in the adipose tissues. Glycerol releases after the perfusion of phentolamine, orciprenaline, and propranolol were also studied. Sixteen subjects were studied (8 men, 8 women, 35 to 45 years of age, body mass index 38 to 50 kg/m2). In women, epinephrine provoked a greater glycerol release than in men in both abdominal and femoral regions (P < .05). In men and women there was a significant decrease in the concentration of glucose and a significant increase in lactate concentration after epinephrine stimulation (P < .001). After 3 weeks of energy restriction, glycerol release after epinephrine stimulation was greater in both sexes than that observed before energy restriction (P < .05). Both phentolamine and orciprenaline stimulated the release of glycerol (P < .01); phentolamine had a higher effect in women, while propranolol had no effect on glycerol release in both sexes. In summary, we have demonstrated that epinephrine provoked a greater lipolytic response in obese women in both abdominal and femoral adipose tissues. The lipolytic response was further enhanced after 3 weeks of energy restriction in each gender. The decrease in glucose concentration suggests that glucose may be reutilized for synthesis into new triacylglycerol. Knowledge about the sensitivity to lipolytic agents in subcutaneous adipose tissue may provide potential new approaches for modulating the lipolytic responses of subcutaneous adipose tissue differently in men and women.

Strategies for the detection of disease genes in pancreatic cancer

The present review summarizes our strategies aimed at identifying and characterizing genetic alterations occurring at the transcriptional and chromosomal level in pancreatic cancer. To study transcriptional alterations we have used a number of techniques including modified versions of differential hybridizations and cDNA RDA (representational difference analysis). These approaches have led to the identification of more than 500 genes with differential expression in pancreatic cancer. To study chromosomal aberrations occurring in pancreatic cancer tissues we used comparative genomic hybridization (CGH). This allowed the identification of a number of chromosomal regions containing putative tumor suppressor genes or oncogenes. Genes isolated in both approaches represent potential new disease genes for pancreatic cancer and are at present being characterized by individual or serial analysis.

Acinar-ductal-carcinoma sequence in transforming growth factor-alpha transgenic mice

Transgenic mice overexpressing transforming growth factor-alpha (TGF-alpha) display an expansion of intrapancreatic fibroblasts and a progressive accumulation of extracellular matrix. This massive fibrosis is associated with an increase in pancreatic size and weight. In parallel, tubular complexes appear that are composed of acinar cells with a decreased height. These acinar cell lose zymogen granules and become transitional cells, which subsequently gain duct cell features. In animals older than one year dysplastic lesions develop, which originate from tubular complexes. Occasionally these dysplastic foci transform to papillary and cystic pancreatic carcinoma. These tumors are positive for the duct-specific antigen Duct-1 and carbonic anhydrase activity indicative of ductal differentiation. Tumors overexpress the epidermal growth factor (EGF)-receptor and p53, but lack K-ras mutations. These data suggest an acinar-ductal-carcinoma sequence in TGF-alpha transgenic mice.

Mechanistic differences of various AT1-receptor blockers in isolated vessels of different origin

The functional inhibitory characteristics of the angiotensin II type 1 receptor blockers (ARB) candesartan; irbesartan; and losartan and its active metabolite EXP 3174 (EXP) were studied in rabbit aortic strips and rat portal vein preparations in vitro. Moreover, plasma-protein binding was determined, and the binding was high (>98. 5%) for all ARBs. These values were needed to relate the concentrations of the ARBs used in vitro to the nonprotein bound concentrations in clinical use. In both vascular preparations, candesartan caused a marked decrease in the maximal contractile response of the angiotensin II (Ang II) concentration-response curve. Losartan, EXP, and irbesartan caused a rightward parallel shift without any major effects on the maximal response to Ang II. The inhibitory effect of candesartan developed slowly (maximal effect after >30 minutes) and lasted >2 hours despite repeated washing of the vessels. The effect of losartan, irbesartan, and EXP had a faster onset, and most of the inhibitory effect disappeared after washing. The duration of the inhibitory effects of the ARBs were not related to lipophilicity of the compounds. Cooling of the rat portal vein preparations to 4 degrees C before administration of candesartan prevented the persistent inhibition of Ang II response seen at 37 degrees C. For the other ARBs studied, the magnitude of inhibition and the speed of recovery of the Ang II response were independent of the incubation temperature before washing. In addition, when candesartan was given to conscious rats, the inhibitory effect on Ang II-induced blood pressure responses persisted during the 24-hour period despite nondetectable plasma concentrations of candesartan at 24 hours. It is concluded that functional inhibitory characteristics of candesartan differ from those of the other ARBs tested. At clinically relevant concentrations, candesartan is an insurmountable and long-lasting antagonist of the vascular contractile responses to Ang II.

Transforming growth factor alpha activates Ha-Ras in human pancreatic cancer cells with Ki-ras mutations

BACKGROUND & AIMS

The aim of this study was to identify signaling pathways that mediate cell proliferation in response to a Ras-activating growth factor, transforming growth factor (TGF)-alpha, in two pancreatic cancer cell lines with constitutively active Ki-Ras, MiaPaCa-2, and Panc-1.

METHODS

ERK1/-2- and p90(rsk) activation were determined by immune complex kinase assays. AP-1 and E74 activation were assessed in transient transfections using luciferase reporter plasmids. Ha-Ras activation was determined using a glutathione S-transferase fusion protein comprising the Ras-binding domain of Raf and by immunocytochemistry, growth by DNA synthesis and colony formation in softagar.

RESULTS

TGF-alpha stimulated activation of ERK1/-2, which was dependent on MEK-1, but independent of PKC activity. TGF-alpha-induced activation of an AP-1 reporter plasmid also required MEK-1 and Ras activity. Using an E74 reporter plasmid, we demonstrate that TGF-alpha indeed activates Ras in both cell lines. In particular, TGF-alpha induced membrane translocation and activation of the Ras isoform Ha-Ras. Finally, TGF-alpha-stimulated DNA synthesis and clonal growth in soft agar were prevented by treatment of cells with a MEK-1 inhibitor or a Ras farnesyl transferase inhibitor.

CONCLUSIONS

The Ha-Ras-ERK cascade plays an important role in TGF-alpha-induced growth of pancreatic cancer cells with activating Ki-ras mutations. Inhibitors of this cascade could constitute novel anticancer agents for pancreatic tumors.

Anti-TNF antibody in Crohn's disease--status of information, comments and recommendations of an international working group

The chimeric anti-TNF antibody Remicade (Infliximab) has recently been approved for human use by the FDA and is now available on the market. Since there is considerable interest in this kind of treatment among patients with Crohn's disease, an international working group has summarized the presently available information about efficacy, side effects and possible problems of this treatment. Studies show that Remicade is effective in the treatment of active Crohn's disease, maintaining remission and fistulae. The working group does not see Infliximab as a first-line treatment for Crohn's disease. It may be used in active phase recurrent disease, chronic active disease and fistulae if standard treatment was not successful. For the surveillance special attention has to be given to the unknown malignancy rate of Infliximab. Infusion should be performed in an institution, routinely performing intravenous infusions and a two-hour surveillance of the patients should be guaranteed to recognize anaphylactic reactions or acute side effects. There is presently no information indication that the combination with immunosuppressants might increase risks or side effects of this treatment. Due to the limited information available the working group would prefer to use Remicade in studies only and recommends central collection and documentation of all data on efficacy and side effects for the next year.

[Prospective Epidemiologic Study of Epigastric Discomfort (PRESTO). Ground work and preliminary results]

BACKGROUND AND OBJECTIVE

Symptoms of dyspepsia (indigestion; upper abdominal discomfort) are one of the most frequent reasons for consulting a general practitioner or internist. Yet there are no up-to-date national data on the epidemiology and course of this symptom complex.

PATIENTS AND METHODS

In an open, prospective, multicentre, epidemiological study (PRESTO) 3016 patients with the suspected diagnosis of "functional dyspepsia" (1228 males, 1788 females, mean age 50 +/- 15 years) were followed for 2 years by 983 physicians in private practice (general practitioners or specialists in internal medicine). Patients with proven gastro-oesophageal reflux or peptic ulcer were excluded. Treatment was at the discretion of the physician. Patients were seen after one month (if under treatment) and then at 6, 12, 18 and 24 months. In addition to personal data, (1) symptoms, diagnosis and treatment of the dyspepsia, (2) socioeconomic aspects and (3) any limitations and the quality of life of each patient were recorded in a standard manner.

RESULTS

At the first interim analysis more than half the patients judged there situation to be one of "chronic stress" or having to cope with a stressful event; nearly 50% thought this to be the cause of the symptoms. Concomitant illnesses were present in 63% of patients. Oesophagogastroduodenoscopy with subsequent medication was performed in 20.6%, a trial of medication (usually drugs stimulating gastric motility) in 65%. No medication was initially given to 14.4% of patients. The most common symptoms were feeling of fullness (92.9%, epigastric pressure sensation (91.5%) and flatulence (87.4%).

CONCLUSION

These preliminary results indicate that a large epidemiological study can be performed by general practitioners and has advantages over the more usual method of enquiry by telephone. Dyspepsia exerts an unusually high degree of stress and results in considerable demands on medical facilities.

Inverse graded relation between alcohol consumption and active infection with Helicobacter pylori

Alcoholic beverages are known to have strong antibacterial activity. It is unclear, however, to what degree their consumption affects colonization of the human stomach with the bacterium Helicobacter pylori, a risk factor of various chronic diseases. The authors assessed the relation between alcohol consumption and active infection with H. pylori in a cross-sectional study among employees of a health insurance company and their household members (n = 425) in southern Germany. Quantitative information on alcohol consumption by beverage type and other factors that were known or suspected to be related to infection status was collected by a standardized questionnaire, and active infection was measured by the 13C-urea breath test. After control for confounding factors, there was a monotonic inverse graded relation between alcohol consumption and H. pylori infection (p for trend = 0.017). The odds ratio of infection among subjects who consumed more than 75 g of alcohol per week compared with subjects who did not drink alcohol was 0.31 (95 percent confidence interval 0.12-0.81). The inverse relation with H. pylori infection was stronger for alcohol consumed in the form of wine than for alcohol from beer. Notwithstanding its cross-sectional design, this study seems to support the hypothesis that alcohol consumption, particularly wine consumption, may reduce the odds of active infection with H. pylori.

Transforming growth factor-beta-induced upregulation of transforming growth factor-beta receptor expression in pancreatic regeneration

The transforming growth factor-beta (TGFbeta) signaling pathway is one important player in the regulation of extracellular matrix turnover and cell proliferation in epithelial regeneration. We used cerulein-induced pancreatitis in rats as a model to investigate the regulation of TGFbeta receptor type I and type II expression on protein and messenger RNA level during regeneration. In the regenerating pancreas, mRNA levels of TGFbeta receptor I and II were significantly increased with a maximum after 2 days. On protein level, expression of TGFbeta receptor II was significantly increased after three to 3-5 days. This elevated expression could be inhibited by neutralizing the endogenous biological activity of TGFbeta1 with a specific antibody. In cultured pancreatic epithelial cells, TGFbeta1 reduced cell proliferation as measured by [3H]thymidine incorporation. Furthermore the transcript levels of TGFbeta1 as well as mRNA and protein concentrations of type I and type II receptor increased during TGFbeta stimulation in vitro. These results indicate that epithelial pancreatic cells contribute to the enhanced TGFbeta1 synthesis during pancreatic regeneration by an autocrine mechanism. TGFbeta1, furthermore, upregulates the expression of its own receptors during the regenerative process, thereby contributing to the increase of the TGFbeta-induced cellular responses.

Integrin alpha6beta1 role in metastatic behavior of human pancreatic carcinoma cells

The factors that determine the metastatic behavior of pancreatic tumor cells are incompletely understood. In this study, we first demonstrate differences in adhesion properties, integrin expression and in vivo integrin function in the metastatic tumor cell line PaTu 8988s compared with the non-metastatic cell line PaTu 8988t. Both cell lines were derived from the same original tumor and exhibit identical genetic fingerprints. Using in vitro adhesion assays performed on purified extracellular matrix components, adhesion of PaTu 8988s cells was significantly increased on the basal membrane component laminin and decreased on the interstitial matrix protein fibronectin compared to PaTu 8988t cells. By immunocytochemistry and flow cytometry, and in correspondence with their adhesive properties, the metastatic PaTu 8988s cells did express a distinct pattern of integrin subunits. Laminin-binding integrins alpha6 and beta4 were overexpressed in PaTu 8988s cells. Fibronectin-binding alpha5 integrins were present at higher levels in the non-metastatic PaTu 8988t cells, whereas the beta1 subunit expression did not differ. Adhesion to laminin or fibronectin was specific and was mediated via integrins alpha6beta1 and alpha5beta1, respectively. In addition, metastasis formation in vivo after injection of cells into the tail vein of nude mice was inhibited by preincubation of PaTu 8988s cells with antibodies directed against the integrin alpha6 or beta1. We conclude that alpha6beta1 integrins are overexpressed and functionally active in metastatic human pancreatic carcinoma cells, and participate in metastasis formation probably through binding to the basal membrane component laminin.

Effects of tropisetron, a 5-HT3 receptor antagonist, on proximal gastric motor and sensory function in nonulcer dyspepsia

BACKGROUND

Visceral hypersensitivity is claimed to be involved in the pathogenesis of nonulcer dyspepsia (NUD). In a double-blind crossover study, we evaluated the effects of tropisetron, a 5-HT3 receptor antagonist, on gastric accommodation, reflex relaxation, and sensitivity in NUD patients.

METHODS

Eight patients and 10 healthy controls received placebo or 5 mg tropisetron on separate days. On each day, gastric accommodation and relaxation were investigated using a gastric barostat. The perception during gastric distension and relaxation was scored by a verbal perception score.

RESULTS

Under both medications, gastric accommodation and postprandial gastric reflex relaxation were not impaired in the NUD patients. The visceral perception was increased in the NUD patients and not substantially influenced by tropisetron.

CONCLUSIONS

Tropisetron does not influence gastric accommodation, reflex relaxation, or gastric sensitivity in NUD patients and healthy controls.

Helicobacter pylori in dental plaque: a comparison of different PCR primer sets

This study was designed to compare different primer sets for PCR analysis of H. pylori in the same series of 40 dental plaque samples. Three pairs of primers, HPU1/HPU2, HP1/HP2, and EHC-U/EHC-L, directed to the urease A gene, 16S rRNA gene, or 860-bp DNA of H. pylori, respectively, were used. Our results demonstrate that EHC-L/EHC-U were more specific and sensitive for H. pylori added to saliva or dental plaque than HPU1/HPU2 and HP1/HP2. The detection rates for H. pylori DNA in dental plaque samples from randomly selected adult patients from the Dental Clinic of the University of Ulm were 26.5% (9/34) for HPU1/HPU2, 78.9% (30/38) for HP1/HP2, and 100% (40/40) for EHC-U/EHC-L (P < 0.001). Nested PCR using primers directed to the 860-bp DNA of H. pylori further confirmed the presence of H. pylori DNA (40/40) in all these samples. Our results indicate that primers EHC-U/EHC-L are to be recommended for PCR detection of H. pylori in the oral cavity.

Integrin alpha6beta1 role in metastatic behavior of human pancreatic carcinoma cells

The factors that determine the metastatic behavior of pancreatic tumor cells are incompletely understood. In this study, we first demonstrate differences in adhesion properties, integrin expression and in vivo integrin function in the metastatic tumor cell line PaTu 8988s compared with the non-metastatic cell line PaTu 8988t. Both cell lines were derived from the same original tumor and exhibit identical genetic fingerprints. Using in vitro adhesion assays performed on purified extracellular matrix components, adhesion of PaTu 8988s cells was significantly increased on the basal membrane component laminin and decreased on the interstitial matrix protein fibronectin compared to PaTu 8988t cells. By immunocytochemistry and flow cytometry, and in correspondence with their adhesive properties, the metastatic PaTu 8988s cells did express a distinct pattern of integrin subunits. Laminin-binding integrins alpha6 and beta4 were overexpressed in PaTu 8988s cells. Fibronectin-binding alpha5 integrins were present at higher levels in the non-metastatic PaTu 8988t cells, whereas the beta1 subunit expression did not differ. Adhesion to laminin or fibronectin was specific and was mediated via integrins alpha6beta1 and alpha5beta1, respectively. In addition, metastasis formation in vivo after injection of cells into the tail vein of nude mice was inhibited by preincubation of PaTu 8988s cells with antibodies directed against the integrin alpha6 or beta1. We conclude that alpha6beta1 integrins are overexpressed and functionally active in metastatic human pancreatic carcinoma cells, and participate in metastasis formation probably through binding to the basal membrane component laminin.

Metabolic and weight-loss effects of a long-term dietary intervention in obese patients

BACKGROUND

Obesity is a chronic disease that has become one of the most serious health problems in Western society.

OBJECTIVE

We assessed the long-term effects of an energy-restricted diet combined with 1 or 2 daily meal replacements on body weight and biomarkers of disease risk in 100 obese patients.

DESIGN

Phase 1 consisted of a 3-mo, prospective, randomized, parallel intervention study of 2 dietary interventions to reduce weight. The energy-restricted diet (5.2-6.3 MJ/d) consisted of conventional foods (group A) or an isoenergetic diet with 2 meals and 2 snacks replaced daily by energy-controlled, vitamin-and-mineral-supplemented prepared foods (group B). Phase 2 consisted of a 24-mo, case-control, weight-maintenance study with an energy-restricted diet and 1 meal and 1 snack replaced daily for all patients.

RESULTS

Total weight loss (as a percentage of initial body weight) was 5.9+/-5.0% in group A and 11.3+/-6.8% in group B (P < 0.0001). During phase 1, mean weight loss in group B (n = 50) was 7.1+/-3.5 kg, with significant reductions in plasma triacylglycerol, glucose, and insulin concentrations (P < 0.0001). Group A patients (n = 50) lost an average of 1.3+/-2.2 kg with no significant improvements in these biomarkers. During phase 2, both groups lost on average an additional 0.07% of their initial body weight every month (P < 0.01). During the 27-mo study, both groups experienced significant reductions in systolic blood pressure and plasma concentrations of triacylglycerol, glucose, and insulin (P < 0.01).

CONCLUSION

These findings support the hypothesis that defined meal replacements can be used for successful, long-term weight control and improvements in certain biomarkers of disease risk.