scholarly journals Deoxyribonucleic Acid Probes Analyses for the Detection of Periodontal Pathogens

2015 ◽  
Vol 16 (9) ◽  
pp. 727-732
Author(s):  
Zoubeida AL Yahfoufi ◽  
Wahib Hadchiti ◽  
Antoine Berberi

ABSTRACT Background In clinical microbiology several techniques have been used to identify bacteria. Recently, Deoxyribonucleic acid (DNA)-based techniques have been introduced to detect human microbial pathogens in periodontal diseases. Deoxyribonucleic acid probes can detect bacteria at a very low level if we compared with the culture methods. These probes have shown rapid and cost-effective microbial diagnosis, good sensitivity and specificity for some periodontal pathogens in cases of severe periodontitis. Materials and methods Eighty-five patients were recruited for the study. Twenty-one subjects ranging between 22 and 48 years of age fulfilled the inclusion and exclusion criteria. Seventy-eight samples became available for DNA probe analysis from the deepest pockets in each quadrant. Results All 21 patients showed positive results for Prevotella intermedia; also, Prevotella gingivalis was identified in 19 subjects, Aggregatibacter actinomycetemcomitans in 6 subjects. P. intermedia was diagnosed positive in 82% of the subgingival samples taken, 79% for P. gingivalis, and 23% for A. actinomycetemcomitans. Conclusion This study shows a high frequency of putative periodontal pathogens by using DNA probe technology, which is semi-quantitative in this study. Deoxyribonucleic acid probes can detect bacteria at very low level about 103 which is below the detection level of culture methods. The detection threshold of cultural methods. Clinical significance The three types of bacteria can be detected rapidly with high sensitivity by using the DNA probe by general practitioners, and thus can help in the diagnosis process and the treatment. How to cite this article Yahfoufi ZAL, Hadchiti W, Berberi A. Deoxyribonucleic Acid Probes Analyses for the Detection of Periodontal Pathogens. J Contemp Dent Pract 2015;16(9): 727-732.

1997 ◽  
Vol 35 (11-12) ◽  
pp. 363-368 ◽  
Author(s):  
T. R. Slifko ◽  
D. E. Friedman ◽  
J. B. Rose ◽  
S. J. Upton ◽  
W. Jakubowski

Cryptosporidium parvum is an infectious enteric protozoan parasite that causes waterborne disease, severe gastroenteritis and is associated with high mortality in immunocompromised individuals. Detection of oocysts in water is very difficult and current methodologies do not determine viability. This project has focused on low level detection of Cryptosporidium parvum in environmental samples using a unique cultural method. Previously, cell culture methods have been used to assess the developmental stages of Cryptosporidium; however, no cultural methods have been employed with environmental samples. The percentage of viable oocysts can be estimated by detecting intracellular developmental stages of the parasite using fluorescently labelled antibodies. Other methods are not capable of low level detection or high sensitivity. We are evaluating detection of single foci of infection, indicating that one of the four sporozoites released from the viable oocyst has infected a single cell.


2018 ◽  
Vol 68 (12) ◽  
pp. 2853-2856 ◽  
Author(s):  
Igor Jelihovschi ◽  
Cristian Drochioi ◽  
Aida Corina Badescu ◽  
Raoul Vasile Lupusoru ◽  
Alexandra Elena Munteanu ◽  
...  

The diagnosis of periodontal disease is mainly based on use of clinical and radiographic evidence. In this study we employed a quantitative PCR analysis of Aggregatibacter actinomycetemcomitans and Treponema denticola as species strongly involved in periodontal diseases, burden in periodontal pockets to detect the main sampling factors that interfere with qPCR results. From 22 patients with advanced periodontal disease, subgingival plaque was comparatively collected by paper points and periodontal Gracey curettes. Samples were collected from the same situs in presence of gingival bleeding and absence of bleeding. The concordance and agreement of results between samples were assessed. The present study demonstrates that subgingival plaque sampling with sterile absorbable paper points is often accompanied by gingival bleeding resulting in quantification biases of periodontal pathogens.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ramesh Yelagandula ◽  
◽  
Aleksandr Bykov ◽  
Alexander Vogt ◽  
Robert Heinen ◽  
...  

AbstractThe COVID-19 pandemic has demonstrated the need for massively-parallel, cost-effective tests monitoring viral spread. Here we present SARSeq, saliva analysis by RNA sequencing, a method to detect SARS-CoV-2 and other respiratory viruses on tens of thousands of samples in parallel. SARSeq relies on next generation sequencing of multiple amplicons generated in a multiplexed RT-PCR reaction. Two-dimensional, unique dual indexing, using four indices per sample, enables unambiguous and scalable assignment of reads to individual samples. We calibrate SARSeq on SARS-CoV-2 synthetic RNA, virions, and hundreds of human samples of various types. Robustness and sensitivity were virtually identical to quantitative RT-PCR. Double-blinded benchmarking to gold standard quantitative-RT-PCR performed by human diagnostics laboratories confirms this high sensitivity. SARSeq can be used to detect Influenza A and B viruses and human rhinovirus in parallel, and can be expanded for detection of other pathogens. Thus, SARSeq is ideally suited for differential diagnostic of infections during a pandemic.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hongbin Chen ◽  
Shuai Yu ◽  
Haiyang Liu ◽  
Jie Liu ◽  
Yongguang Xiao ◽  
...  

AbstractAssessment of lung and heart states is of critical importance for patients with pneumonia. In this study, we present a small-sized and ultrasensitive accelerometer for continuous monitoring of lung and heart sounds to evaluate the lung and heart states of patients. Based on two-stage amplification, which consists of an asymmetric gapped cantilever and a charge amplifier, our accelerometer exhibited an extremely high ratio of sensitivity to noise compared with conventional structures. Our sensor achieves a high sensitivity of 9.2 V/g at frequencies less than 1000 Hz, making it suitable to use to monitor weak physiological signals, including heart and lung sounds. For the first time, lung injury, heart injury, and both lung and heart injuries in discharged pneumonia patients were revealed by our sensor device. Our sound sensor also successfully tracked the recovery course of the discharged pneumonia patients. Over time, the lung and heart states of the patients gradually improved after discharge. Our observations were in good agreement with clinical reports. Compared with conventional medical instruments, our sensor device provides rapid and highly sensitive detection of lung and heart sounds, which greatly helps in the evaluation of lung and heart states of pneumonia patients. This sensor provides a cost-effective alternative approach to the diagnosis and prognosis of pneumonia and has the potential for clinical and home-use health monitoring.


2014 ◽  
Vol 1685 ◽  
Author(s):  
Ho Yeon Son ◽  
Yoon Sung Nam ◽  
Woo Soo Kim

ABSTRACTHere we introduce a facile method to fabricate a flexible piezoelectric sensor using one-dimensional (1-D) piezoelectric poly(vinylidene fluoride) (PVDF) nanofibers directly produced onto flexible printed electrodes by electro-spinning without an additional poling process. The flexible silver electrodes are fabricated on polyethylene terephthalate (PET) using silver nanowires by easy and cost-effective spraying deposition. The electrospun PVDF nanofibers have uniaxially aligned arrays on the electrodes by using a rotating collector. The fabricated PVDF piezoelectric sensors demonstrate the piezoelectric responses with repeated mechanical stimuli with good flexibility and high sensitivity. We expect that the facile fabrication of PVDF piezoelectric sensors on flexible printed electrodes can be usefully exploited to integrate the piezoelectric sensors into flexible and stretchable functional electronic devices.


2021 ◽  
pp. 143-165
Author(s):  
V.G. Maralov ◽  
◽  
V.A. Sitarov ◽  

The relevance of the problem is due to the importance of identifying factors that determine the propensity of students to coercion or nonviolence, creating psychological and pedagogical conditions for the formation of the socionomic sphere of nonviolent competencies for future specialists at universities. The theoretical basis of the study was the position of nonviolence as a daily practice of interaction, by which we understand the ability of a person to choose from a number of possible alternatives that carry the least charge of coercion. The aim of the work was to study the influence of irrational beliefs and sensitivity to a person (interest, empathy, understanding and assistance) on the students’ tendency to coercion, manipulation, non-violence and non-interference in the processes of interaction with people. The hypothesis was tested that the tendency of students to coercion, manipulation, and noninterference will be due to expressed irrational beliefs and low level of sensitivity to a person and the tendency to non-violence will be explained by the absence of irrational beliefs and a high level of sensitivity to a person. The study involved 125 students of pedagogical and psychological faculties of the Moscow Humanitarian and Cherepovets State universities. The authors used questionnaires to identify the positions of interaction among students and sensitivity to a person, as well as a list of irrational beliefs proposed by A. Beck and A. Freeman. It is established that the tendency to both coercion and manipulation are determined by the beliefs of anti-social type and low sensitivity to the person. The tendency to manipulate the narcissistic beliefs, high interest in people and understanding them, at the same time the tendency to non-violence and non-interference are determined by beliefs of avoidant and dependent types with a low level of understanding people. And a tendency to non-interference is determined by beliefs of dependent type with unexpressed orientation on helping. The tendency to nonviolence is determined by the high sensitivity to a person and the absence of irrational beliefs of antisocial, passive-aggressive and narcissistic types. As a result, the conclusion is made about the need to form purposefully the ability to nonviolent interaction among students, which should include the work on awareness and overcoming irrational beliefs and the development of sensitivity to a person. The obtained results can be used in practical work with students on the formation of their nonviolent competencies.


Author(s):  
Fatemeh Rahmani ◽  
Yahya Ehteshaminia ◽  
Hamid Mohammadi ◽  
Seif Ali Mahdavi

Introduction: Trichomoniasis is the most common non-viral sexually transmitted infection in the world, caused by the protozoan parasite Trichomonas vaginalis, which infects the urogenital tract of men and women. Approximately, 250 million new cases of Trichomonas vaginalis Infection are reported worldwide each year. Trichomoniasis is also considered an important HIV co-infection. The infection is often asymptomatic but can be accompanied by symptoms such as severe inflammation, itching and irritation, foamy discharge, and malodorous smell mucus, but the signs and symptoms of the disease are not sufficient for specific diagnosis. Material and Methods: In this study, the websites of PubMed, Google Scholar, SID, and Margiran were searched and related articles were reviewed. Results: Only screening and the use of highly sensitive and specific diagnostic methods can identify asymptomatic individuals. Today, the most common way to diagnose the infection is to use wet slide, Pap smear and culture methods that do not have high sensitivity and specificity. Also, due to the increase in infection and its complications, finding an efficient, rapid, and easy test to detect the parasite and differentiate Trichomoniasis vaginitis from other sexually transmitted diseases is considered important and necessary. Conclusion: Nowadays, there are several diagnostic methods that differentiate trichomoniasis infection from other sexually transmitted infections with high accuracy and sensitivity. Of course, existing diagnostic methods mostly use women's urine and vaginal samples for diagnosis, and methods that specifically diagnose the infection in men are more limited.


2015 ◽  
Vol 10 (1) ◽  
pp. 13-20
Author(s):  
Elisabete Galeazzo ◽  
Marcos C. Moraes ◽  
Henrique E. M. Peres ◽  
Michel O. S. Dantas ◽  
Victor G. C. Lobo ◽  
...  

Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics. However, there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of devices composed by multi-walled carbon nanotubes (MWCNT) deposited between aluminum electrodes on glass substrates by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance were noticed depending on the MWCNT quantities deposited. Other electrical properties of devices such as high sensitivity, fast response time and stability are also characterized in humid environment. A humidity sensing mechanism is proposed on the basis of charge transfer between adsorbed water molecules and the MWNTC surface or between water and the glass surface.


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