Development Of Non-invasive Tests Research Articles

S1547 When and Where to Look? Hepato-Biliary Malignancy in Lynch Syndrome

INTRODUCTION: Patients with Lynch Synrome have well established germline mutations in DNA mismatch repair genes that put them at higher risk for the development of multiple different types of malignancy. Risk of development of colorectal cancer is probably the most well described followed by associations with endometrial, stomach, renal pelvis, brain, skin, amongst others. Current guidelines recommend screening based on probability of these malignancies. CASE DESCRIPTION/METHODS: A 34 year old male known to carry the mutation for Lynch Syndrome was admitted with generalized fatigue. The patient reported feeling progressively worse and described associated symptoms of pruritus, dark urine and light colored stools. As part of his surveillance for Lynch Syndrome, he undergoes a colonoscopy every 2 years and an EGD every 4 years; both of which were recently normal. He otherwise has no other past medical history and takes no medications. Exam notable for normal vital signs, scleral icterus and jaundice. Labs significant for AST 112 IU/L, ALT 299 IU/L, ALP 137 IU/L, total bilirubin 8.3 mg/dL, direct bilirubin 5.4 mg/dL. A CT scan showed moderate intra and extra hepatic biliary ductal dilatation, pancreatic ductal dilatation, and an ampullary lesion. Ampullary mass seen and biopsied via ERCP, pathology showing moderately differentiated adenocarcinoma of pacnreatobiliary type. He was treated with Whipple surgery and FOLFIRINOX chemotherapy regimen. DISCUSSION: Lynch Syndrome is diagnosed in patients and families with germline mutations in DNA mismatch repair genes. This mutation puts patients at much higher risk of developing multiple types of cancer. Our case describes a patient with pancreatobiliary type adenocarcinoma of the ampulla. Small intestinal cancer is thought to affect a small population of patients with Lynch syndrome (anywhere from 0.4-12%) and society guidelines differ on appropriate screening with some recommending periodic capsule endoscopy. Routine screening for pancreatic cancer is only recommended in patients and families with Lynch syndrome who have a family member or members diagnosed with pancreatic disease. As patients with Lynch Syndrome are at risk for malignancy in virtually any location, data on less common presentations and development of noninvasive testing will be more and more valuable.

A Comprehensive Review: Development of Biosensors Based on Graphene-Mesoporous Combined Materials

Reliable data obtained from analysis of DNA, proteins, bacteria and other disease-related molecules or organisms in biological samples have become a fundamental and crucial part of human health diagnostics and therapy. After a brief summary of the implication of template based ordered mesoporous materials in electrochemical science, the various types of inorganic and organic-inorganic hybrid mesostructured used to date in electroanalysis and the corresponding electrode configurations are described. The development of non-invasive tests that are rapid, sensitive, specific and simple would allow patient discomfort to be prevented, delays in diagnosis to be avoided and the status of a disease to be followed up. The use of biosensors for the early diagnosis of diseases has become widely accepted as a point-of-care diagnosis with appropriate specificity in a short time. To allow a reliable diagnosis of a disease at an early stage, highly sensitive biosensors are required as the corresponding biomarkers are generally expressed at very low concentrations. In past 50 years, various biosensors have been researched and developed encompassing a wide range of applications. This contrasts the limited number of commercially available biosensors. Lately, graphene-based materials have been considered as superior over other nanomaterials for the development of sensitive biosensors. The advantages of graphenebased sensor interfaces are numerous, including enhanced surface loading of desired ligand due to the high surface-to-volume ratio, excellent conductivity and a small band gap that is beneficial for sensitive electrical and electrochemical read-outs, as well as tunable optical properties for optical read-outs such as fluorescence and plasmonics. In this paper, we review the advances made in recent years on graphenebased biosensors in the field of medical diagnosis.

Graphene-based biosensors.

Reliable data obtained from analysis of DNA, proteins, bacteria and other disease-related molecules or organisms in biological samples have become a fundamental and crucial part of human health diagnostics and therapy. The development of non-invasive tests that are rapid, sensitive, specific and simple would allow patient discomfort to be prevented, delays in diagnosis to be avoided and the status of a disease to be followed up. Bioanalysis is thus a progressive discipline for which the future holds many exciting opportunities. The use of biosensors for the early diagnosis of diseases has become widely accepted as a point-of-care diagnosis with appropriate specificity in a short time. To allow a reliable diagnosis of a disease at an early stage, highly sensitive biosensors are required as the corresponding biomarkers are generally expressed at very low concentrations. In the past 50 years, various biosensors have been researched and developed encompassing a wide range of applications. This contrasts the limited number of commercially available biosensors. When it comes to sensing of biomarkers with the required picomolar (pM) sensitivity for real-time sensing of biological samples, only a handful of sensing systems have been proposed, and these are often rather complex and costly. Lately, graphene-based materials have been considered as superior over other nanomaterials for the development of sensitive biosensors. The advantages of graphene-based sensor interfaces are numerous, including enhanced surface loading of the desired ligand due to the high surface-to-volume ratio, excellent conductivity and a small band gap that is beneficial for sensitive electrical and electrochemical read-outs, as well as tunable optical properties for optical read-outs such as fluorescence and plasmonics. In this paper, we review the advances made in recent years on graphene-based biosensors in the field of medical diagnosis.

Abstract IA17: Non-invasive detection of somatic mutations in the management of CRC

Abstract Somatic mutations are exquisitely specific cancer biomarkers that are not merely associated with cancer, rather they are the root cause of cancer. The realization that this markers are present in bodily fluids of individuals with cancer and the development of digital methods for their detection ushered a new era in the management of cancer patients providing opportunities for the development of noninvasive methods for early detection, detection of minimal residual disease, monitoring of response to therapy, early detection of resistance and diagnosis. There are both technical and biological challenges for the development of noninvasive tests for the detection of somatic mutations. The number of circulating tumor DNA (ctDNA) molecules is very low compared to that of DNA molecules with wild-type sequence and requires very sensitive methods for their detection. To this end, we have developed a method called SafeSeqS that is able to reliably resolve mutations at 0.01% in background of wild-type DNA across multiple regions of interest. To determine the spectrum of cancers in which ctDNA measurements could prove clinically useful, we evaluated the detection of ctDNA in plasma (liquid biopsy) from patients with a large number of tumor types. ctDNA was detectable in the plasma of most patients with advanced tumor, but in less than 50% in patients with certain tumor types, like primary brain cancers. More than half of the patients with localized colorectal cancer, gastroesophageal cancer, pancreatic cancer, and breast adenocarcinoma, had detectable ctDNA in their plasma. The sensitivity of detection of advanced colorectal cancer (CRC) was close to 100% and greater than 75% for localized cancers indicating that liquid biopsy could be utilized for a number of clinical applications. One such application is the detection of minimal residual disease after surgery or therapy with curative intent. Currently, there are not efficient ways to determine which patients are cured and which have residual disease that will result in recurrence. In a prospective cohort of 230 patients with resected stage II colon cancer, ctDNA detection after surgery provided direct evidence of residual disease and identified patients at very high risk of recurrence. Another application of liquid biopsy in CRC is monitoring resistance to therapies, like EGFR, providing an early indication that resistance ensues. The holy grail of non-invasive detection of cancer is early detection. Most tumors are incurable because they are detected at a late stage. Early detection of cancer, before symptoms appear, at a stage curable by surgery, holds great promise for decreasing the rate of deaths due to cancer. We will share our efforts on the development of tests for the early detection of cancer. Our overall vision is that non-invasive, somatic mutation based tests become routine in the clinical management of cancer patients. Citation Format: Nickolas Papadopoulos, Yuxuan Wang, Joshua Cohen, Ralph Hruban, Peter Gibbs, Jeanne Tie, Luis Diaz, Kenneth Kinzler, Bert Vogelstein. Non-invasive detection of somatic mutations in the management of CRC. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr IA17.

Vertically Aligned Nitrogen-Doped Carbon Nanotube Carpet Electrodes: Highly Sensitive Interfaces for the Analysis of Serum from Patients with Inflammatory Bowel Disease.

The number of patients suffering from inflammatory bowel disease (IBD) is increasing worldwide. The development of noninvasive tests that are rapid, sensitive, specific, and simple would allow preventing patient discomfort, delay in diagnosis, and the follow-up of the status of the disease. Herein, we show the interest of vertically aligned nitrogen-doped carbon nanotube (VA-NCNT) electrodes for the required sensitive electrochemical detection of lysozyme in serum, a protein that is up-regulated in IBD. To achieve selective lysozyme detection, biotinylated lysozyme aptamers were covalently immobilized onto the VA-NCNTs. Detection of lysozyme in serum was achieved by measuring the decrease in the peak current of the Fe(CN)6(3-/4-) redox couple by differential pulse voltammetry upon addition of the analyte. We achieved a detection limit as low as 100 fM with a linear range up to 7 pM, in line with the required demands for the determination of lysozyme level in patients suffering from IBD. We attained the sensitive detection of biomarkers in clinical samples of healthy patients and individuals suffering from IBD and compared the results to a classical turbidimetric assay. The results clearly indicate that the newly developed sensor allows for a reliable and efficient analysis of lysozyme in serum.

D’autres acteurs dans la croissance folliculaire et ovocytaire : rôle des microARNs dans le dialogue cumulo-ovocytaire

The good folliculogenesis evolution is fundamental for the obtaining of a competent oocyte, able to lead to pregnancy, once fertilized. During the follicular development, the oocyte is in close contact with surrounding cumulus cells (CCs) to form a cumulus-oocyte complex. The bidirectional exchange between oocyte and contiguous CCs via gap junction communications and paracrine signaling is important for oocyte competence and CCs development. These reciprocal regulations are controlled by some key genes. Recently, it has been demonstrated that these genes are themselves regulated by short RNAs fragments (approximately 22 nucleotides), called microRNAs. The identification and the quantification in the CCs of the microRNAs regulating these genes could promote the development of non invasive tests in order to assess the oocyte quality and its ability to provide embryo with a high implantation potential. This approach could be decisive in the embryo selection to transfer and could avoid the risk of multiple pregnancies by the replacement of a single embryo.

Staging Liver Fibrosis in Hepatitis C: A Challenge for This Decade

The limitations of and the invasive nature of liver biopsy has spurred extensive interest in the development of non-invasive tests to measure liver fibrosis in patients with chronic hepatitis C. Clinically applicable non-invasive tests, including radiological studies, elastography, and serum markers, all of which perform extremely well in excluding significant disease and diagnosing cirrhosis. FibroScan and acoustic radiation force impulse elastography are two elastography-based tests that show promise. In this new era of increased cure rates with newly Food and Drug Administration-approved drugs and the availability of multiple non-invasive tests of liver fibrosis, we anticipate a decreasing need for liver biopsies in the management of chronic hepatitis C.

Proteomics of colorectal cancer: Overview of discovery studies and identification of commonly identified cancer-associated proteins and candidate CRC serum markers

Colorectal cancer (CRC) is a common cause of cancer-related mortality in the developed world. Improved methods for early detection and disease management are urgently needed. Many efforts in the past 5 years have been devoted to protein biomarker discovery for early detection of CRC. Here, we discuss identity-based studies employing tandem mass spectrometry that analyzed clinical material as well as model systems. Through meta-analysis we provide a list of CRC-associated tissue proteins discovered in multiple studies, with the greater majority being 2D gel-based discoveries coupled to MS/MS. So far only a limited number of CRC-associated proteins have been validated in serum for non-invasive testing for CRC. This list includes several intracellular and nuclear proteins that a priori would not have been considered candidate biomarkers based on their predicted subcellular localization. Finally, we highlight promising new directions that combine targeted analyses of subcellular proteomes, like the cell surface, secretome, exosome, and nuclear matrix, with nanoLC-MS/MS-based proteomics. We anticipate that in the near future, these novel mass spectrometry-based in-depth approaches will uncover many novel, specific CRC marker candidates in clinical tissues and that their targeted validation with multi-reaction monitoring MS will speed up development of non-invasive tests in feces and serum/plasma.

Practical and Ethical Considerations of Noninvasive Prenatal Diagnosis

CHROMOSOME ABNORMALITIES SUCH AS TRISOMY 21 (Down syndrome), other autosomal trisomies, sex chromosome abnormalities, and balanced and unbalanced translocations can be prenatally diagnosed. For many individuals, the availability of prenatal diagnosis removes the fear of having a child with a severe physical or mental disability. For chromosome abnormalities that are associated with significant morbidity and mortality, the public’s acceptance of prenatal diagnosis has been well established during the past 4 decades during which testing has been available. Current standards of care involve screening women to identify those at highest risk of having a fetus with a chromosome abnormality and then offering definitive diagnosis through the analysis of a chorionic villus sample or amniotic fluid cells. The American College of Obstetricians and Gynecologists recommends that all women be offered aneuploidy screening through various combinations of maternal serum tests and sonographic measurements. However, these screening tests are associated with relatively high false-positive rates and often involve multistep protocols that may take weeks to complete. Obtaining chorionic villus or amniocentesis specimens is expensive and requires an invasive procedure that carries a small risk to the fetus and the possibility of adverse maternal effects. Moreover, these invasive tests are usually not provided until late in the first trimester or second trimester. Amniocentesis and chorionic villus sampling have therefore imposed a rate-limiting step in the provision of prenatal diagnosis; in general only those patients at the highest risk of having a fetus with Down syndrome or another disorder of major clinical significance have been tested. For more than 30 years, these problems have spurred attempts to develop noninvasive prenatal diagnosis. The discovery of substantial amounts of conceptus-derived nucleic acids (DNA and RNA mostly from trophoblasts) in maternal blood has resulted in proof of principle and also in the development of noninvasive tests. Currently, it is possible to determine fetal sex, establish Rh genotype of the fetus, and diagnose genetic disorders or carrier status for paternally inherited mutations. A number of strategies have been proposed for noninvasive prenatal diagnosis for aneuploidy, including an RNA-based method for Down syndrome detection, which is expected to be commercially available within a year. The benefits of a noninvasive prenatal diagnosis are clear. It eliminates the dangers associated with invasive testing, and it allows for definitive diagnoses earlier in pregnancy, thus resulting in safer terminations of affected pregnancies, reduction of parental anxiety, and decreased medical costs. As a result, uptake of the testing is likely to be higher, which can translate into additional health and economic benefits for both individuals and, indirectly, society at large. The introduction of noninvasive prenatal diagnosis would require the ill-prepared medical system to change how patients are counseled and how cases are managed. Additionally, significant ethical issues are associated with noninvasive prenatal diagnosis. In this Commentary, we discuss these effects with a focus on the forthcoming introduction of noninvasive prenatal diagnosis for fetal Down syndrome.

How to improve drug development for functional disorders

Although several studies and publications have been devoted to the evaluation of novel pharmacotherapeutic approaches in functional bowel disorders, the number of successful drug development programs has been disappointingly small. The difficulties of adequate drug development are related to the heterogeneity of the functional disorders, the lack of understanding of the underlying pathophysiology, and the lack of short-term mechanistic studies that predict clinical outcome. When drugs address a single pathophysiological mechanism, the heterogeneity has a negative impact on the possible margin when patients are not selected on the basis of the specific pathophysiological disorder. Although mechanistic studies may provide a rationale for drug development, they do not predict symptomatic success and do not identify the most appropriate dose for clinical trials. Further mechanistic studies are badly needed to improve our understanding of the pathophysiological basis of functional disorders. Future studies might aim at the development of non-invasive test that identify relevant pathophysiological mechanisms, at refining assessment of symptom pattern and at the development of short-term therapeutic trials.

3 Laboratory diagnosis of venous thromboembolism

Venous thromboembolism is a common medical condition in both out-patients and in-patients. Despite the development of non-invasive tests, the diagnosis of deep vein thrombosis and pulmonary embolism remains a clinical challenge. In an effort to improve diagnostic accuracy and to reduce the necessity of serial testing, laboratory markers of thrombin generation and fibrinolysis have been investigated as first-line screening tests. Although the majority of markers are elevated in acute thrombosis, D-dimer, a specific derivative of cross-linked fibrin, appears to have the most potential clinical utility. Accuracy studies and preliminary management trials suggest that rapid D-dimer enzyme-linked immunosorbent assays and the whole blood agglutination assay, SimpliRED D-dimer (Agen Biomedical, Brisbane, Australia), have strong potential as exclusionary tests in patients with suspected venous thrombosis.

Inspiratory muscle testing in stable COPD patients.

Exploration of inspiratory muscles in stable chronic pulmonary disease patients can be important in the investigation of a respiratory handicap unsatisfactorily explained by alterations of the passive respiratory system, or in the follow-up of patients undergoing treatments that can interfere with muscle function. Compensatory mechanisms tend to counterbalance the deleterious effects of hyperinflation in these patients, and precise clinical data are needed in order to avoid mistakes due to underverified hypotheses. Investigation of inspiratory muscle function requires the study of output data under various states of activity of the system. As outputs, volume displacement lacks specificity, pressure measurements can be more specific but are at times invasive and should be associated with lung volume measurements, electromyography is methodologically complex, nonquantitative and of poor reproducibility. Voluntary manoeuvres depend upon subject co-operation, and do not allow partitioning of output between the action of different muscle groups. Transcutaneous electrical phrenic nerve stimulation is devoid of these inconveniences, but it explores only one muscle (the diaphragm) under conditions that are not "natural" (relaxed rib cage). Recently, perspectives for easier clinical assessment of inspiratory muscle function in chronic obstructive pulmonary disease patients have been opened by cervical magnetic stimulation, better understanding of the meaning of mouth pressure in relationship to phrenic stimulation, and development of noninvasive tests, such as nostril pressure during sniff or phonomyography. If validated, such tests should provide a reasonably limited panel of clinical tools to better appreciate muscle function in this setting.