Development of an Automatic Electrokinetically-Controlled Microfluidic Immunoassay for the Detection of Helicobacter Pylori

2005 ◽  
Author(s):  
Yali Gao ◽  
Guoqing Hu ◽  
Frank Y. H. Lin ◽  
Philip M. Sherman ◽  
Dongqing Li
Keyword(s):  
Helicobacter Pylori ◽  
Detection Limit ◽  
Experimental Studies ◽  
Lab On A Chip ◽  
Protein Antigens ◽  
Immunoassay Technique ◽  
Microfluidic Immunoassay ◽  
Colorimetric Immunoassay ◽  
On Chip ◽  
H Pylori

A novel automatic electrokinetically-controlled immunoassay lab-on-a-chip was developed in this paper. The microchip was made of poly(dimethylsiloxane) (PDMS)/glass using photolithography and replica molding. The immunoassay technique using anti-Helicobacter pylori antibody was applied to detect H. pylori protein antigens. Rhodamine-labeled secondary antibody was employed for signal generation. Experiments were first conducted on a straight microchannel to prove the feasibility of an electrokinetically-driven immunoassay. The detection limit for the coating antigen was found to be 1 ng/μL. Automatic electrokinetically-controlled immunoassay experiments were further carried out on a microchannel network. Numerical simulation and experimental studies were combined for the first time to demonstrate an integrated, electrokinetically-controlled immunoassay lab-on-a-chip. The electrokinetically driven, time-dependent reagent delivery processes were simulated using finite element method (FEM). Fully automatic on-chip experiments were accomplished by sequentially changing the applied electric field. It was found that the lab-on-a-chip can realize much shorter assay time, reduced reagent consumptions and automation while the detection limit is better than the conventional colorimetric immunoassay.

scholarly journals Helicobacter pylori and colorectal neoplasms: a concise review

2021 ◽  
Vol 58 (1) ◽  
pp. 114-119
Author(s):  
Luiz Gonzaga Vaz COELHO ◽  
Maria Clara Freitas COELHO
Keyword(s):  
Helicobacter Pylori ◽  
Colorectal Neoplasms ◽  
Malignant Tumors ◽  
Colonic Neoplasms ◽  
Experimental Studies ◽  
Current Data ◽  
Diagnostic Methods ◽  
Dominant Factor ◽  
Concise Review ◽  
H Pylori

ABSTRACT Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

scholarly journals Sample introduction interface for on-chip nucleic acid-based analysis of Helicobacter pylori from stool samples

Lab on a Chip ◽  
2016 ◽  
Vol 16 (11) ◽  
pp. 2108-2115 ◽  
Author(s):  
O. Mosley ◽  
L. Melling ◽  
M. D. Tarn ◽  
C. Kemp ◽  
M. M. N. Esfahani ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Nucleic Acid ◽  
Genetic Analysis ◽  
Microfluidic Device ◽  
Sample Introduction ◽  
Stool Samples ◽  
On Chip ◽  
H Pylori

Processing of stool samples using an IFAST microfluidic device for the genetic analysis of infectious pathogens such asH. pylori.

scholarly journals Ozonoterapia y su acción en la bacteria helicobacter pylori. // Ozonetherapy and its action in the bacterium helicobacter pylori.

Ciencia Unemi ◽  
2017 ◽  
Vol 10 (22) ◽  
pp. 98-104
Author(s):  
Johana Bustamante Oviedo ◽  
Cecilia Sánchez Borja ◽  
Jovanny Santos Luna ◽  
Andrés Medina Preciado ◽  
Marisela Segura Osorio
Keyword(s):  
Helicobacter Pylori ◽  
Human Body ◽  
Adverse Reactions ◽  
Therapeutic Agent ◽  
Experimental Studies ◽  
Medical Sciences ◽  
Ozone Therapy ◽  
Duodenal Ulcers ◽  
H Pylori ◽  
Positive Results

La ozonoterapia es la técnica que consiste en la aplicación en el organismo humano, con fines terapéuticos, de una mezcla compuesta de gas ozono con oxígeno medicinal, en la acción de la bacteria helicobacter pylori. Por lo tanto, se plantea como objetivo, el análisis de  información recopilada, antecedentes, principales hallazgos que sustentan el uso científico y médico del ozono, específicamente enfocado en el tratamiento de helicobacter pylori, a través de la búsqueda de fuentes electrónicas disponibles y revisión de conceptos relacionados con la rama de las ciencias médicas, que se ocupa del tratamiento de pacientes con infecciones gástricas por helycobacter pilory, sin profundizar en aspectos moleculares y bioquímicos. Los resultados obtenidos mediante estudios experimentales evidencian que el uso del ozono, como terapeútica para la infección por h. pylori en el tratamiento de úlceras duodenales, conlleva resultados positivos, con una propiedad favorecedora como es la ausencia o escasa presencia de reacciones adversas. Ozone therapy is the technique that consists of the application of a compound mixture of ozone gas with medicinal oxygen in the human body for therapeutic purposes, in the action of the bacterium helicobacter pylori. Therefore, the objective of this study is to analyze the information collected, the background, the main findings that support the scientific and medical use of ozone, specifically focused on the treatment of helicobacter pylori, through the search of available electronic sources and review of Concepts related to the branch of medical sciences, which deals with the treatment of patients with gastric infections by helycobacter pilory, without deepening in molecular and biochemical aspects. The results obtained through experimental studies show that the use of ozone as a therapeutic agent for h. Pylori in the treatment of duodenal ulcers, leads to positive results, with a favorable property such as the absence or low presence of adverse reactions.

scholarly journals CagA Effector Protein in Helicobacter pylori-Infected Human Gastric Epithelium in Vivo: From Bacterial Core and Adhesion/Injection Clusters to Host Cell Proteasome-Rich Cytosol

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 618 ◽  
Author(s):  
Vittorio Necchi ◽  
Vittorio Ricci ◽  
Patrizia Sommi ◽  
Enrico Solcia
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Host Cell ◽  
Experimental Studies ◽  
Intracellular Distribution ◽  
Gastric Epithelium ◽  
Effector Protein ◽  
H Pylori

A key role in the carcinogenic action of Helicobacter pylori is played by the effector protein CagA, the first identified oncoprotein of the bacterial world. However, the present knowledge in regard to the bacterial injection of CagA into epithelial cells (through a type IV secretion system) and its intracellular fate is based primarily on experimental studies in vitro. Our study was aimed to investigate, in H. pylori-infected human gastric epithelium, CagA delivery and intracellular distribution in order to identify any in vivo counterpart of the cell injection mechanism described in vitro and any intracellular cytoplasmic site of preferential CagA distribution, thus shedding light on the natural history of CagA in vivo. By transmission electron microscopy and ultrastructural immunocytochemistry (which combine precise molecule localization with detailed analysis of bacterial-host cell interaction and epithelial cell ultrastructure), we investigated endoscopic biopsies of gastric antrum from H. pylori-infected dyspeptic patients. Our findings provide support for CagA direct injection into gastric epithelial cells at bacterial adhesion sites located on the lateral plasma membrane and for its cytosolic intracellular distribution with selective concentration inside peculiar proteasome-rich areas, which might be site not only of CagA degradation but also of CagA-promoted crucial events in gastric carcinogenesis.

The rod-to-coccoid body transformation in cultures of Helicobacter pylori

1990 ◽  
Vol 48 (3) ◽  
pp. 626-627
Author(s):  
A. R. Crooker ◽  
W. G. Kraft ◽  
T. L. Beard ◽  
M. C. Myers
Keyword(s):  
Helicobacter Pylori ◽  
Growth Cycle ◽  
Negative Bacterium ◽  
Body Formation ◽  
Coccoid Form ◽  
Spiral Form ◽  
Prolonged Culture ◽  
H Pylori ◽  
Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

Peptische Ulzera und Helicobacter pylori: Wie wir wissen, was wir wissen

2015 ◽  
Vol 72 (7) ◽  
pp. 475-480
Author(s):  
Raphael Scholl
Keyword(s):  
Helicobacter Pylori ◽  
Kontrollierte Studie ◽  
H Pylori ◽  
Peptische Ulzera

Zusammenfassung. Zu den wichtigsten Ursachen peptischer Ulzera gehört das Bakterium Helicobacter pylori. Aber wie wurde dieser ursächliche Zusammenhang nachgewiesen? Aufschluss darüber gibt die Geschichte und Theorie einer Reihe einschlägiger Studien, die in den 1980er Jahren durchgeführt wurden. Am Anfang stand die Entdeckung einer blossen Korrelation zwischen dem neu entdeckten Bakterium und peptischen Ulzera in Magenbiopsien. Unklar blieb, ob das Bakterium die Krankheit verursachte, oder ob es bloss eine opportunistische bakterielle Besiedlung darstellte. Ohne Tiermodell war der experimentelle Nachweis der Richtung der Verursachung jedoch schwierig: Zwar wurde in einem couragierten Selbstversuch mit einer geschluckten Bakterienkultur eine Gastritis beobachtet – aber der Einzelfall war wenig aussagekräftig. Die Schwächen des Selbstversuchs liessen sich durch eine randomisierte, Plazebo-kontrollierte Studie beheben, die den Anforderungen des dritten Koch’schen Postulats gerecht wurde. Darüber hinaus war es notwendig, erste Aufschlüsse über den Mechanismus der ursächlichen Verbindung zwischen H. pylori und peptischen Ulzera zu gewinnen: Wie zum Beispiel kann das Bakterium im sauren Milieu des Magens überleben? Die wissenschaftshistorische und wissenschaftstheoretische Betrachtung des Falls illustriert, wie medizinisches Wissen schrittweise aufgebaut wird.

Helicobacter-pylori-Infektion

2011 ◽  
Vol 11 (05) ◽  
pp. 271-276
Author(s):  
G. Flemming
Keyword(s):  
Helicobacter Pylori ◽  
H Pylori

ZusammenfassungInfektionen mit Helicobacter pylori zählen zu den häufigsten chronischen bakteriellen Infektionen bei Menschen. Es zeigen sich deutliche geografische Unterschiede in der Prävalenz. In den westlichen Industrienationen nimmt die Infektionsrate seit den letzten Jahrzehnten ab. Die Infektion mit H. pylori erfolgt meist in der ersten Lebensdekade. Die Infektion kann lebenslang persistieren, wenn keine antibiotische Eradikation erfolgt. H.-pylori-Infektionen können diverse Erkrankungen hervorrufen, dazu gehören das Ulkus ventrikuli, Ulkus duodeni, das Magenkarzinom und das Lymphom des Mukosa-assoziierten lymphatischen Gewebes (MALT-Lymphom). Die Gefahr der malignen Entartung ist bei Kindern wesentlich geringer als bei Erwachsenen. Ein großes Problem stellen die zunehmenden Antibiotikaresistenzen dar. Daher sollte die Therapie möglichst immer nach Sensibilitätstestung erfolgen. Eine Eradikationskontrolle mittels non-invasiver Testung empfiehlt sich binnen vier bis acht Wochen nach Therapieende.

Роль лекарственных взаимодействий в эффективности и безопасности кларитромицина при эрадикации Helicobacter pylori

2019 ◽  
Vol 53 (8) ◽  
pp. 8-10
Author(s):  
Светлана Юрьевна Сереброва ◽  
Елена Николаевна Карева ◽  
Наталия Николаевна Еременко ◽  
Алексей Борисович Прокофьев ◽  
Дарья Олеговна Кургузова ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
H Pylori

В обзорной статье описаны современные риски резистентности, нежелательных лекарственных реакций и лекарственных взаимодействий кларитромицина при его применении в качестве компонента терапевтических схем эрадикации H. pylori. Кислотонеустойчивость кларитромицина в кислой среде определяет зависимость фармакологических свойств препарата от эффективности ингибиторов протонной помпы, что может быть одной из причин резистентности возбудителя к макролиду. Потенциал лекарственных взаимодействий кларитромицина связан c его способностью метаболизироваться с помощью CYP3A4 и мощно ингибировать этот фермент.

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