Search

Reverse-phase protein arrays (RPPAs) have become an important tool for the sensitive and high-throughput detection of proteins from minute amounts of lysates from cell lines and cryopreserved tissue. The current standard method for tissue preservation in almost all hospitals worldwide is formalin fixation and paraffin embedding, and it would be highly desirable if RPPA could also be applied to formalin-fixed and paraffin embedded (FFPE) tissue. We investigated whether the analysis of FFPE tissue lysates with RPPA would result in biologically meaningful data in two independent studies. In the first study on breast cancer samples, we assessed whether a human epidermal growth factor receptor (HER) 2 score based on immunohistochemistry (IHC) could be reproduced with RPPA. The results showed very good concordance between the IHC and RPPA classifications of HER2 expression. In the second study, we profiled FFPE tumor specimens from patients with adenocarcinoma and squamous cell carcinoma in order to find new markers for differentiating these two subtypes of non-small cell lung cancer. p21-activated kinase 2 could be identified as a new differentiation marker for squamous cell carcinoma. Overall, the results demonstrate the technical feasibility and the merits of RPPA for protein expression profiling in FFPE tissue lysates.

This study describes infiltration patterns of multiple myeloma in spinal MR imaging and correlates the findings with biopsies, survival rates, and signal intensity measurements in unenhanced and enhanced studies.Fifty-three patients with multiple myeloma and 53 age-matched controls underwent MR imaging of the spine. Twenty-nine patients underwent sagittal T1-weighted spin-echo enhanced imaging and all patients underwent sagittal T1-weighted spin-echo unenhanced and opposed-phase gradient-recalled echo images, and signal intensity measurements were taken. MR imaging was correlated to marrow specimens (n = 40) and a clinical staging system. The probability of survival was also calculated. Finally, we performed qualitative visual evaluation (infiltration pattern, degree of tumor involvement) and a quantitative evaluation (marrow signal intensity ratios, contrast enhancement).Five infiltration patterns were found: normal-appearing marrow with low-grade interstitial infiltration (n = 5), focal (n = 18), diffuse (n = 12), focal and diffuse (n = 13), and salt-and-pepper (n = 5). Infiltration pattern correlated with clinical staging; all patients with normal-appearing and salt-and-pepper patterns were clinically stage I. Diffuse marrow infiltration was assessed by marrow ratios: low-grade infiltration, greater than 2.0; intermediate, 1.0-2.0; highgrade, less than 1.0. Contrast enhancement with a signal intensity increase greater than 40% indicated diffuse infiltration. In the control group, all of whom had no marrow disease, enhancement varied (mean +/- SD, 16% +/- 8.9%) but did not exceed 40%. Marrow involvement on MR images correlated significantly with clinical staging and survival (por = .001).MR imaging with opposed gradient-recalled echo sequences and contrast enhancement provided data that allowed us to classify infiltration patterns and to quantify diffuse marrow involvement in multiple myeloma, both of which correlated to clinical staging and biopsy. Also, the MR data was of prognostic value. Therefore, like laboratory parameters, biopsies, and radiographs, MR imaging can be a supporting pillar in staging and planning treatment of patients with multiple myeloma.

Long-term outcome was reviewed in 266 consecutive patients with metastatic non-seminomatous germ cell tumours treated at a single institution. The overall 3 year survival was 77%, and 3 year progression-free survival was 71%. Multivariate analysis identified the following clinical features as independent prognostic factors: the presence of liver, bone or brain metastasis, serum human chorionic gonadotropin > or = 10000 U l-1 and/or alpha-fetoprotein > or = 1000 ng ml-1, a mediastinal mass > 5 cm and the presence of 20 or more lung metastases. Age was not of prognostic significance. Patients without any of the above poor-risk factors had a 3 year survival of 91% regardless of etoposide- or vinblastine-containing chemotherapy compared with 61% for the remaining patients. However, etoposide-containing protocols led to significantly improved survival in patients with at least one poor risk factor. After 612 patient-years of observation no case of secondary leukaemia was observed among 119 surviving patients who had received etoposide as part of their treatment. With a median follow-up of 93 months, five patients developed a second germ cell tumour, two patients nongerm cell malignancies. Fourteen patients relapsed after a disease-free interval of more than 2 years, and nine patients died more than 5 years after commencement of treatment underscoring the need to report long-term results. There is some evidence that cumulative experience translates into improved survival and cure rates for patients with poor-risk metastatic disease.

PURPOSE To define the different infiltration patterns in the spine in multiple myeloma, in correlation with histological and clinical findings. Quantitative signal evaluation with contrast media (Gd-DTPA). To compare the results in MRI with X-ray films. MATERIAL AND METHODS 61 patients with proven multiple myeloma and 50 controls were examined (1.0 Tesla, T1-w SE, opposed phase GE images). RESULTS Five infiltration patterns with different clinical stages were detected: normal bone marrow (11%) in cases of low interstitial marrow infiltration (biopsy), pure diffuse infiltration (25%), focal involvement (33%), combined diffuse/focal infiltration (23%) and a "salt-and pepper" pattern (8%). In diffuse plasmacytoma the 40% signal intensity increase was modification of diffuse infiltration. MRI proved to be more sensitive than radiography. CONCLUSION MRI is able to show the type and the extension of bone marrow infiltration in multiple myeloma. Diffuse involvement can be objective with gadopentetate dimeglumine.

BACKGROUND Extragonadal germ cell tumors account for only 2-5% of all germ cell neoplasms in adult males. Because these tumors are rare and, in part, biologically distinct from their testicular counterparts, their optimal management continues to be defined. METHODS The medical records of 51 patients with extragonadal germ cell tumors were reviewed. All patients were treated with cisplatin-based chemotherapy at a single institution between 1981 and 1994. RESULTS Thirty-five patients had nonseminomatous germ cell tumors and 16 had pure seminomas. Sixteen tumors arose in the mediastinum (12 nonseminomas, 4 seminomas), and 35 in the retroperitoneum (23 nonseminomas, 12 seminomas). Six of 12 patients (50%) with mediastinal nonseminomas survived with no evidence of disease (NED) at 33-137 months (median, 96 months); all had undergone surgery as part of their treatment. Fifteen of 23 patients (65%) with retroperitoneal nonseminomas are alive with NED at 2-145 months (median, 39 months). Fifteen of 16 patients (94%) with extragonadal seminomas survived with NED at 2-141 months (median, 66 months), and 1 patient died from late irradiation-related toxicity. Three patients with retroperitoneal nonseminomas developed a testicular seminoma at 35, 42, and 77 months, respectively; all are currently disease free. CONCLUSIONS Mediastinal and retroperitoneal nonseminomas have distinct clinical features. As in other series, clinical outcome is somewhat inferior for mediastinal nonseminomas compared with retroperitoneal nonseminomas. Regardless of the site of presentation, the vast majority of patients with extragonadal seminomas can expect cure. It remains controversial, however, whether retroperitoneal germ cell tumors are metastatic from a primary testicular germ cell tumor. Cancer 1996;77:526-32.

UDP-glucose pyrophosphorylase (UGP) is a nucleotidyltransferase of central importance in all organisms and considered an attractive drug target in the human pathogens Leishmania and Trypanosoma. He...

Long-term outcome of salvage treatment was reviewed in 67 unselected male patients relapsing during or after their primary cisplatin-based chemotherapy for metastatic germ cell tumours. Seven patients underwent only surgery and/or radiotherapy as curatively intended salvage treatment. Thirty-five patients (52%) had a complete or partial response to salvage treatment, 20 (57%) of whom relapsed again. With a median follow-up of 90 months (range 3-143 months) 20 patients (30%) are alive with no evidence of disease, 15 continuously disease-free and five currently disease-free. The 5 year survival from start of salvage treatment is 37% for the group as a whole. Multivariate analysis identified age < or = 35 years, complete response to primary treatment and a relapse-free interval > 3 months as independent predictors of favourable outcome of salvage treatment. A group of patients with these good-risk factors (42%) had a 5 year survival of 72% compared with the remaining patients (58%) with a 5 year survival of only 11%. Whereas patients with good-risk features may be adequately managed by conventional salvage treatment, the remaining patients carry a very poor prognosis and require innovative and more aggressive approaches.

Summary Background The goal of the study was to analyse long-term outcome after post-chemotherapy surgery in male patients with non-seminomatous germ cell tumours (NSGCT). Patients and methods We reviewed the charts of 111 patients with metastatic NSGCT treated at a single institution from 1979 to 1993 who underwent post-chemotherapy resection of residual masses after normalisation of tumour markers. The prognostic relevance of the extent of tumour residuals, the comprehensiveness of surgery and the histology at resection was analysed. Results Thirteen patients (12%) harboured viable cancer, and 46 patients (41%) mature teratoma at post-chemotherapy surgery. Only seven (54%) of the 13 patients with viable cancer remained continuously disease-free. Incomplete surgery predicted an impaired outcome (62% vs. 86% survival), although only one recurrence was observed at a site of an incompletely resected mass. Moreover, a progression-free interval ≤ 3 months after post-chemotherapy surgery was correlated with worse subsequent survival (p–0.0001). Conclusions Post-chemotherapy surgery remains an essential part of the treatment for metastatic NSGCT. Resection of viable cancer and mature teratoma is of therapeutic benefit. Viable cancer at surgery defines the need for further chemotherapy.

Elastin is one of the major extracellular matrix proteins associated with connective tissue. Its degradation leads to the liberation of the unique amino acids desmosine and isodesmosine. These have shown utility as biomarkers of elastin breakdown for disease progression, patient stratification, and drug efficacy. So far, the quantitation of desmosines in plasma is hampered by complex sample preparation. Here we demonstrate an improved and simplified procedure for detecting both free and total desmosines. The method is based on spiking with a deuterium-labeled desmosine standard, ethanol precipitation, propionylation, high-performance liquid chromatography (HPLC) separation, and selected reaction monitoring (SRM) mass spectrometry. The performance of the assay is illustrated by comparing the levels of free and total desmosines in normal healthy plasma and those from patients diagnosed with chronic obstructive pulmonary disease (COPD). A conserved ratio of 1:3 for free to total desmosine was found. The determination of free desmosine has higher accuracy than that of total desmosine; therefore, it is the method of choice when plasma volume is limiting. Finally, we show that the plasma desmosine concentration correlates with age and body mass index.

A major application of tumor biomarkers is in serial monitoring of cancer patients, but there are no published guidelines on how to evaluate biomarkers for this purpose. The European Group on Tumor Markers has convened a multidisciplinary panel of scientists to develop guidance on the design of such monitoring trials. The panel proposes a 4-phase model for biomarker-monitoring trials analogous to that in use for the investigation of new drugs. In phase I, biomarker kinetics and correlation with tumor burden are assessed. Phase II evaluates the ability of the biomarker to identify, exclude, and/or predict a change in disease status. In phase III, the effectiveness of tumor biomarker–guided intervention is assessed by measuring patient outcome in randomized trials. Phase IV consists of an audit of the long-term effects after biomarker monitoring has been included into standard patient care. Systematic well-designed evaluations of biomarkers for monitoring may provide a stronger evidence base that might enable their earlier use in evaluating responses to cancer therapy.

Proteolysis represents one of the most tightly controlled physiological processes, as proteases create events that will typically commit pathways in an irreversible manner. Despite their implication in nearly all biological systems, our understanding of the role of proteases in disease pathology is often limited. Several approaches to studying proteolytic activity as it relates to biology, pathophysiology, and drug therapy have been published, including the recently described terminal amine isotopic labeling of substrates (TAILS) strategy by Kleifeld and colleagues. Here, we investigate TAILS as a methodology based on targeted enrichment and mass spectrometric detection of endogenous N-terminal peptides from clinically relevant biological samples and its potential to provide quantitative information on proteolysis and elucidation of the protease cleavage sites. While optimizing the most current protocol, by switching to a streamlined one-tube format and simplifying the reagents' removal steps, we demonstrate the advantages over previously published methods and provide solutions to some of the technical challenges presented in the Kleifeld publication. We also identify some of the current and unresolved limitations. We use human plasma as a model system to provide data, which illustrates some of the key analytical parameters of the modified TAILS procedure, including specificity, sensitivity, quantitative precision, and accuracy.

BackgroundHCC is diagnosed in approximately half a million people per year, worldwide. Staging is a more complex issue than in most other cancer entities and, mainly due to unique geographic characteristics of the disease, no universally accepted staging system exists to date. Focusing on survival rates we analyzed demographic, etiological, clinical, laboratory and tumor characteristics of HCC-patients in our institution and applied the common staging systems. Furthermore we aimed at identifying the most suitable of the current staging systems for predicting survival.Methodology/principal findingsOverall, 405 patients with HCC were identified from an electronic medical record database. The following seven staging systems were applied and ranked according to their ability to predict survival by using the Akaike information criterion (AIC) and the concordance-index (c-index): BCLC, CLIP, GETCH, JIS, Okuda, TNM and Child-Pugh. Separately, every single variable of each staging system was tested for prognostic meaning in uni- and multivariate analysis. Alcoholic cirrhosis (44.4%) was the leading etiological factor followed by viral hepatitis C (18.8%). Median survival was 18.1 months (95%-CI: 15.2-22.2). Ascites, bilirubin, alkaline phosphatase, AFP, number of tumor nodes and the BCLC tumor extension remained independent prognostic factors in multivariate analysis. Overall, all of the tested staging systems showed a reasonable discriminatory ability. CLIP (closely followed by JIS) was the top-ranked score in terms of prognostic capability with the best values of the AIC and c-index (AIC 2286, c-index 0.71), surpassing other established staging systems like BCLC (AIC 2343, c-index 0.66). The unidimensional scores TNM (AIC 2342, c-index 0.64) and Child-Pugh (AIC 2369, c-index 0.63) performed in an inferior fashion.Conclusions/significanceCompared with six other staging systems, the CLIP-score was identified as the most suitable staging system for predicting prognosis in a large German cohort of predominantly non-surgical HCC-patients.

Maternal smoking during pregnancy has been associated with overweight and obesity in childhood and is strongly correlated with children's tobacco smoke exposure before and after pregnancy. We investigated the independent association of tobacco smoke exposure at various pre- and postnatal periods and overweight at age 6. A total of 1,954 children attending the 2001-2002 school entrance health examination in the city of Aachen, Germany, were included into this study. Height and weight were measured, BMI was calculated. Tobacco smoke exposure at various periods, other lifestyle and sociodemographic factors were ascertained by questionnaire. Multiple logistic regression models were used to assess the association between tobacco smoke exposure and overweight. Prevalence of overweight was 8.9%. Significant positive associations were found with maternal smoking before and during pregnancy and during the first and sixth year of life. When all smoking periods were included into one logistic model simultaneously, secondhand smoke exposure after birth remained positively associated with overweight at age 6 at either one of the two time periods (first year only: odds ratio (OR) (95% confidence interval (CI)): 2.94 (1.30-6.67), sixth year only: 2.57 (1.64-4.04), respectively) or at both (4.43 (2.24-8.76)). Exposure to tobacco smoke during the first years of life appears to be a key risk factor for development of childhood overweight.

Nucleotide sugars and the enzymes that are responsible for their synthesis are indispensable for the production of complex carbohydrates and, thus, for elaboration of a protective cellular coat for many organisms such as the protozoan parasite Leishmania. These activated sugars are synthesized de novo or derived from salvaged monosaccharides. In addition to UDP-glucose (UDP-Glc) pyrophosphorylase, which catalyzes the formation of UDP-Glc from substrates UTP and glucose-1-phosphate, Leishmania major and plants express a UDP-sugar pyrophosphorylase (USP) that exhibits broad substrate specificity in vitro. The enzyme, likely involved in monosaccharide salvage, preferentially generates UDP-Glc and UDP-galactose, but it may also activate other hexose- or pentose-1-phosphates such as galacturonic acid-1-phosphate or arabinose-1-phosphate. In order to gain insight into structural features governing the differences in substrate specificity, we determined the crystal structure of the L. major USP in the APO-, UTP-, and UDP-sugar-bound conformations. The overall tripartite structure of USP exhibits a significant structural homology to other nucleotidyldiphosphate-glucose pyrophosphorylases. The obtained USP structures reveal the structural rearrangements occurring during the stepwise binding process of the substrates. Moreover, the different product complexes explain the broad substrate specificity of USP, which is enabled by structural changes in the sugar binding region of the active site.

BACKGROUND: Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed. METHODS: Published reports relevant to use of tumor markers for 4 cancer sites-liver, bladder, cervical, and gastric-were critically reviewed. RESULTS: alpha-Fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 mu g/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease. Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures. Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use. CONCLUSIONS: Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers. (C) 2009 American Association for Clinical Chemistry

Background: Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.Methods: Published reports relevant to use of tumor markers for 4 cancer sites—liver, bladder, cervical, and gastric—were critically reviewed.Results: α-Fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 μg/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease.Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures.Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use.Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death in the world. The majority of HCCs develops on the basis of a chronic liver disease. This often complicates diagnosis and therapy. Non-invasive diagnostic criteria are based on dynamic imaging techniques and the serum level of AFP (alpha-fetoprotein). When evaluating HCC patients for therapy, besides tumor burden and localisation, the therapeutic evaluation must also consider the general condition of the patient and his/her liver function. For this purpose, the BCLC algorithm of the Barcelona Clinic for Liver Disease has proven helpful. Only one-third of the patients can be cured by resection, transplantation or local tumour ablation. In locally advanced cases transarterial procedures including transarterial chemoembolisation and radioembolisation are applied. HCC is a chemo-resistant tumour and chemotherapy is not accepted as standard of care in HCC. Sorafenib is the first systemic treatment with proven efficacy approved for the treatment of advanced and metastatic HCC. Interdisciplinary management of HCC patients is essential in order to provide every patient with the optimal therapy at his specific stage of disease.

The Leishmania parasite glycocalyx is rich in galactose-containing glycoconjugates that are synthesized by specific glycosyltransferases that use UDP-galactose as a glycosyl donor. UDP-galactose biosynthesis is thought to be predominantly a de novo process involving epimerization of the abundant nucleotide sugar UDP-glucose by the UDP-glucose 4-epimerase, although galactose salvage from the environment has been demonstrated for Leishmania major. Here, we present the characterization of an L. major UDP-sugar pyrophosphorylase able to reversibly activate galactose 1-phosphate into UDP-galactose thus proving the existence of the Isselbacher salvage pathway in this parasite. The ordered bisubstrate mechanism and high affinity of the enzyme for UTP seem to favor the synthesis of nucleotide sugar rather than their pyrophosphorolysis. Although L. major UDP-sugar pyrophosphorylase preferentially activates galactose 1-phosphate and glucose 1-phosphate, the enzyme is able to act on a variety of hexose 1-phosphates as well as pentose 1-phosphates but not hexosamine 1-phosphates and hence presents a broad in vitro specificity. The newly identified enzyme exhibits a low but significant homology with UDP-glucose pyrophosphorylases and conserved in particular is the pyrophosphorylase consensus sequence and residues involved in nucleotide and phosphate binding. Saturation transfer difference NMR spectroscopy experiments confirm the importance of these moieties for substrate binding. The described leishmanial enzyme is closely related to plant UDP-sugar pyrophosphorylases and presents a similar substrate specificity suggesting their common origin.

Background CpG island hypermethylation is a common epigenetic event in colorectal cancer. The presence of simultaneous methylation of multiple genes is associated with poor prognosis in many types of tumours including colorectal cancer. We have shown earlier that the hypermethylation of the genes HLTF and HPP1/TPEF are independent prognostic serum markers in colorectal cancer identifying patients with increased risk of death. The purpose of this study was to analyse whether these factors also identify patients at risk of disease recurrence after curative surgery. Methods Pretherapeutic sera of 106 patients curatively resected for colorectal cancer with known 5-year follow-ups were analysed for the presence of methylation of the genes HLTF and HPP1/TPEF. Results HLTF serum methylation was associated with an increased risk of disease recurrence by a factor of 2.7 (95% confidence interval: 1.2–6.0; P=0.014). Multivariate analysis showed methylated HLTF serum DNA to be independently associated with poor outcome and a relative risk of disease recurrence of 2.5 (95% confidence interval: 1.1–5.6; P=0.023). Conclusion Here, we show for the first time that a DNA methylation-based surrogate marker can serve as a predictor of disease recurrence in colorectal cancer.

Saturation transfer difference (STD) Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful method for studying protein-ligand interactions in solution. The STD NMR method is capable of identifying the binding epitope of a ligand when bound to its receptor protein. Ligand protons that are in close contact with the receptor protein receive a higher degree of saturation, and as a result stronger STD NMR signals can be observed. Protons that are either less or not involved in the binding process reveal no STD NMR signals. Therefore, the STD NMR method is an excellent tool to investigate how a binding ligand interacts with its receptor molecule. The STD NMR experiment is easy to implement and only small amounts of native protein are required. This chapter comprises a detailed experimental protocol to acquire STD NMR spectra and determine the binding epitope of a ligand bound to its target protein. As representative examples the ligands uridyl-triphosphate (UTP) and uridyl-glucose-diphosphate (UDP-glucose) when bound to the Leishmania major UDP-glucose-pyrophosphorylase (UGP) as target protein are examined.

In a retrospective and prospective follow-up study from 1968 to 1989, bone marrow biopsy specimens, serum beta-2-microglobulin (SB2M) levels, and the clinical features of 251 patients with multiple myeloma (MM) and 28 patients with monoclonal gammopathy of undetermined significance (MGUS) were investigated. The main histologic variables (tumor cell type, tumor growth, tumor load, and fibrosis), SB2M level, serum thymidine kinase (STK) level, and various clinical parameters were analyzed to determine factors of value in monitoring the clinical phases of activity in MM. Our recently proposed prognostic strategy combining bone marrow histologic type, SB2M level, and signs of organ failure was tested for its ability to (1) diagnose the early and smoldering variants; (2) facilitate decisions on the time of initiation, the type and duration of initial induction therapy in the pretreatment phases (active and rapidly progressive phases); and (3) characterize variations in tumor regression and tumor-host interactions during chemotherapy (early treatment, plateau, relapse, transition, and refractory phases). The results indicate that this clinicopathologic monitoring combines information both on stage and aggressivity of MM and thus facilitates therapeutic decisions in the various clinical phases of MM.

Dipeptidyl peptidase 4 (DPP4) inhibitors represent a novel class of oral anti-hyperglycemic agents. The complete pharmacological profile of these protease inhibitors remains unclear. In order to gain deeper insight into the in vivo effects caused by DPP4 inhibition, two different DPP4 inhibitors (vildagliptin and AB192) were analyzed using differential peptide display. Wistar rats were treated with the DPP4 inhibitors (0.3mgkg(-1); 1mgkg(-1) or 3mgkg(-1) body weight) and DPP4 activity was measured before and at the end of the experiment. One hour after compound administration, blood plasma samples were collected to generate peptide displays and to subsequently identify differentially regulated peptides. A dose-dependent decrease in blood plasma DPP4 activity was measured for both inhibitors. DPP4 inhibition influenced collagen metabolism leading to depletion of collagen derived peptides (e.g. collagen alpha 1 (III) 521-554) and accumulation of related N-terminally extended collagen derived peptides (e.g. collagen alpha 1 (III) 519-554). Furthermore, the intact amyloid rat BRI (1-23) peptide was detected in plasma following in vivo DPP4 inhibition. DPP4 catalyzed cleavage kinetics of the BRI peptide were determined in vitro. The k(cat) and K(m) for cleavage by DPP4 were 5.2s(-1) and 14microM, respectively, resulting in a specificity constant k(cat)/K(m) of 0.36 x 10(6)s(-1)M(-1). Our results demonstrate that differential peptide analysis can be applied to monitor action of DPP4 inhibition in blood plasma. For the first time effects on basal collagen metabolism following DPP4 inhibition in vivo were demonstrated and the BRI amyloid peptide was identified as a novel DPP4 substrate.

Saturation transfer difference (STD) Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful method for studying protein-ligand interactions in solution. The STD NMR method is capable of identifying the binding epitope of a ligand when bound to its receptor protein. Ligand protons that are in close contact with the receptor protein receive a higher degree of saturation, and as a result stronger STD NMR signals can be observed. Protons that are either less or not involved in the binding process reveal no STD NMR signals. Therefore, the STD NMR method is an excellent tool to investigate how a binding ligand interacts with its receptor molecule. The STD NMR experiment is easy to implement and only small amounts of native protein are required. This chapter comprises a detailed experimental protocol to acquire STD NMR spectra and determine the binding epitope of a ligand bound to its target protein. As representative examples the ligands uridyl-triphosphate (UTP) and uridyl-glucose-diphosphate (UDP-glucose) when bound to the Leishmania major UDP-glucose-pyrophosphorylase (UGP) as target protein are examined.

The histologic and cytologic distinction of malignant mesothelioma from carcinomas metastatic to the pleura or peritoneum is often problematic. For this reason immunologic methods are being increasingly used as diagnostic adjuncts. This review summarizes 40 studies on the expression of carcinoembryonic antigen in mesotheliomas and in lung and other carcinomas involving the pleura or peritoneum. Carcinoembryonic antigen was identified immunohistochemically in 11% of mesotheliomas and in 84% of carcinomas examined and immunocytochemically (in serous effusions) in 4% and 58%, respectively. In serum and in pleural or ascitic fluid, significantly elevated levels of carcinoembryonic antigen are commonly associated with (lung) carcinomas but rarely with mesotheliomas. Thus, together with identification of the antigen in serum, pleural fluid, or ascitic fluid, immunohistochemical and immunocytochemical techniques for detecting carcinoembryonic antigen provide a valuable aid for distinguishing malignant mesothelioma from metastatic carcinomas.

Considering the high incidence of galactofuranose (Gal(f)) in pathogens and its absence from higher eukaryotes, the enzymes involved in the biosynthesis of this unusual monosaccharide appear as attractive drug targets. However, although the importance of Gal(f) in bacterial survival or pathogenesis is established, its role in eukaryotic pathogens is still undefined. Recently, we reported the identification and characterization of the first eukaryotic UDP-galactopyranose mutases. This enzyme holds a central role in Gal(f) metabolism by providing UDP-Gal(f) to all galactofuranosyltransferases. In this work, the therapeutical potential of Gal(f) metabolism in Leishmania major was hence evaluated by targeted replacement of the GLF gene encoding UDP-galactopyranose mutase. In L. major, Gal(f) is present in the membrane anchor of the lipophosphoglycan (LPG) and in glycoinositolphospholipids. Accordingly, the generated glf(-) mutant is deficient in LPG backbone and expresses truncated glycoinositolphospholipids. These structural changes do not influence the in vitro growth of the parasite but lead to an attenuation of virulence comparable with that observed with a mutant exclusively deficient in LPG.

The aim of this article is to present updated guidelines for the use of serum, tissue and faecal markers in colorectal cancer (CRC). Lack of specificity and sensitivity preclude the use of all existing serum markers for the early detection of CRC. For patients with stage II or stage III CRC who may be candidates for either liver resection or systemic treatment should recurrence develop, CEA should be measured every 2-3 months for at least 3 years after diagnosis. Insufficient evidence exists to recommend routine use of tissue factors such as thymidylate synthase, microsatellite instability (MSI), p53, K-ras and deleted in colon cancer (DCC) for either determining prognosis or predicting response to therapy in patients with CRC. Microsatellite instability, however, may be used as a pre-screen for patients with suspected hereditary non-polyposis colorectal cancer. Faecal occult blood testing but not faecal DNA markers may be used to screen asymptomatic subjects 50 years or older for early CRC.