Diagnostics

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9 pages, 2301 KiB

Open AccessEditorial

Trends in Multiplex Immunoassays for In Vitro Diagnostics and Point-of-Care Testing

by Sandeep Kumar Vashist

Diagnostics 2021, 11(9), 1630; https://doi.org/10.3390/diagnostics11091630 - 07 Sep 2021

Cited by 7 | Viewed by 3312

Abstract

The tremendous advances in multiplex immunoassays (MIAs) are leading to novel in vitro diagnostics (IVD) and point-of-care testing (POCT) [...] Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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Research

Jump to: Editorial

11 pages, 4620 KiB

Open AccessArticle

A Novel Tongue Pressure Measurement Instrument with Wireless Mobile Application Control Function and Disposable Positioning Mouthpiece

by Hsiu-Yueh Liu, Chun-Hung Chen, Chao-Hung Kuo, Ming-Chu Feng, Jen-Hao Chen, Hsuan-Wen Wang, Kun-Chun Chen and Chun-Li Lin

Diagnostics 2021, 11(3), 489; https://doi.org/10.3390/diagnostics11030489 - 10 Mar 2021

Cited by 5 | Viewed by 3006

Abstract

This study developed a novel chair-side tongue pressure (TP) measuring instrument with a disposable positioning mouthpiece controlled using a smartphone application (APP), denoted as the TP wireless application (TPWA). The mouthpiece was designed with a palate-shaped air balloon containing a tongue contact bump [...] Read more.

This study developed a novel chair-side tongue pressure (TP) measuring instrument with a disposable positioning mouthpiece controlled using a smartphone application (APP), denoted as the TP wireless application (TPWA). The mouthpiece was designed with a palate-shaped air balloon containing a tongue contact bump and a plastic bite positioning tube. Fatigue load testing was performed to evaluate mouthpiece durability by applying 700 displacement cycles (50 times a day for one week during training, with twice the safety factor) on the air balloon. The main component used in developing this instrument was a silicon pressure sensor equipped with wireless Bluetooth connection. Young (52 adults; mean age = 20.23 ± 2.17) and elderly (40 adults; mean age = 72.60 ± 7.03) individuals participated in the test with the new instrument, with the results compared to those of a commercial device. The TPWA mouthpiece fatigue test showed that mean response pressures were maintained at 12 kPa. No significant (p > 0.05) differences were found during testing repetitions 0–10 and 701–710. There were no significant differences in the maximum TP values presented between the test sequences using different instruments for young and elderly participants. The TPWA results showed that TP values gradually decreased with increasing age (40.77 kPa for young and 16.55 kPa for elderly participants). The maximum TP for males (43.51 kPa) was significantly larger than that for females (35.14 kPa) in the young group, but an opposite trend was seen in the elderly group (12.97 for males and 17.59 for females). Thus, this study developed a novel chair-side TP measurement instrument with Bluetooth wireless mobile application control. A durable positioning oral mouthpiece was approved for measuring pressure sufficiently, reliably, and precisely for TP screening. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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11 pages, 1673 KiB

Open AccessArticle

Improved Influenza Diagnostics through Thermal Contrast Amplification

by Yilin Liu, Li Zhan, Yiru Wang, Joseph Kangas, Daniel Larkin, David R. Boulware and John C. Bischof

Diagnostics 2021, 11(3), 462; https://doi.org/10.3390/diagnostics11030462 - 07 Mar 2021

Cited by 5 | Viewed by 2768

Abstract

Influenza poses a serious health threat and creates an economic burden for people around the world. The accurate diagnosis of influenza is critical to the timely clinical treatment of patients and the control of outbreaks to protect public health. Commercially available rapid influenza [...] Read more.

Influenza poses a serious health threat and creates an economic burden for people around the world. The accurate diagnosis of influenza is critical to the timely clinical treatment of patients and the control of outbreaks to protect public health. Commercially available rapid influenza diagnostic tests (RIDTs) that are operated by visual readout are widely used in clinics to screen influenza infections, but RIDTs suffer from imperfect analytical sensitivity, especially when the virus concentration in the sample is low. Fortunately, the sensitivity can be simply improved through an add-on signal amplification step, i.e., thermal contrast amplification (TCA). To demonstrate the advantage of TCA for influenza diagnosis, we conducted a prospective cohort study on 345 clinical specimens collected for influenza A and B testing during the 2017–2018 influenza season. All samples were tested using the Quidel QuickVue Influenza A + B test, followed by a TCA readout, and then confirmatory polymerase chain reaction testing. Through the TCA detecting sub-visual weak positives, TCA reading improved the overall influenza sensitivity by 53% for influenza A and 33% for influenza B over the visual RIDTs readings. Even though the specificity was compromised slightly by the TCA protocol (relative decrease of 0.09% for influenza A and 0.01% for influenza B), the overall performance was still better than that achieved by visual readout based on comparison of their plots in receiver operating characteristic space and F1 scores (relative increase of 14.5% for influenza A and 12.5% for influenza B). Performing a TCA readout on wet RIDTs also improved the overall TCA performance (relative increase in F1 score of 48%). Overall, the TCA method is a simple and promising way to improve the diagnostic performance of commercial RIDTs for infectious diseases, especially in the case of specimens with low target analytes. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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13 pages, 2300 KiB

Open AccessArticle

Development of a Multiplex Loop-Mediated Isothermal Amplification (LAMP) Method for Simultaneous Detection of Spotted Fever Group Rickettsiae and Malaria Parasites by Dipstick DNA Chromatography

by Lavel Chinyama Moonga, Kyoko Hayashida, Naoko Kawai, Ryo Nakao, Chihiro Sugimoto, Boniface Namangala and Junya Yamagishi

Diagnostics 2020, 10(11), 897; https://doi.org/10.3390/diagnostics10110897 - 02 Nov 2020

Cited by 12 | Viewed by 4080

Abstract

Spotted fever group (SFG) rickettsiae causes febrile illness in humans worldwide. Since SFG rickettsiosis’s clinical presentation is nonspecific, it is frequently misdiagnosed as other febrile diseases, especially malaria, and complicates proper treatment. Aiming at rapid, simple, and simultaneous detection of SFG Rickettsia spp. [...] Read more.

Spotted fever group (SFG) rickettsiae causes febrile illness in humans worldwide. Since SFG rickettsiosis’s clinical presentation is nonspecific, it is frequently misdiagnosed as other febrile diseases, especially malaria, and complicates proper treatment. Aiming at rapid, simple, and simultaneous detection of SFG Rickettsia spp. and Plasmodium spp., we developed a novel multiple pathogen detection system by combining a loop-mediated isothermal amplification (LAMP) method and dipstick DNA chromatography technology. Two primer sets detecting SFG Rickettsia spp. and Plasmodium spp. were mixed, and amplified products were visualized by hybridizing to dipstick DNA chromatography. The multiplex LAMP with dipstick DNA chromatography distinguished amplified Rickettsia and Plasmodium targeted genes simultaneously. The determined sensitivity using synthetic nucleotides was 1000 copies per reaction for mixed Rickettsia and Plasmodium genes. When genomic DNA from in vitro cultured organisms was used, the sensitivity was 100 and 10 genome equivalents per reaction for Rickettsia monacensis and Plasmodium falciparum, respectively. Although further improvement will be required for more sensitive detection, our developed simultaneous diagnosis technique will contribute to the differential diagnosis of undifferentiated febrile illness caused by either SFG Rickettsia spp. or Plasmodium spp. in resource-limited endemic areas. Importantly, this scheme is potentially versatile for the simultaneous detection of diverse infectious diseases. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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17 pages, 3590 KiB

Open AccessArticle

Personalization of Aspirin Therapy Ex Vivo in Patients with Atherosclerosis Using Light Transmission Aggregometry

by Hamzah Khan, Reid C. Gallant, Abdelrahman Zamzam, Shubha Jain, Sherri Afxentiou, Muzammil Syed, Zachary Kroezen, Meera Shanmuganathan, Philip Britz-McKibbin, Margaret L. Rand, Heyu Ni, Mohammed Al-Omran and Mohammad Qadura

Diagnostics 2020, 10(11), 871; https://doi.org/10.3390/diagnostics10110871 - 26 Oct 2020

Cited by 10 | Viewed by 2409

Abstract

Acetylsalicylic acid (ASA), also known as aspirin, appears to be ineffective in inhibiting platelet aggregation in 20–30% of patients. Light transmission aggregometry (LTA) is a gold standard platelet function assay. In this pilot study, we used LTA to personalize ASA therapy ex vivo [...] Read more.

Acetylsalicylic acid (ASA), also known as aspirin, appears to be ineffective in inhibiting platelet aggregation in 20–30% of patients. Light transmission aggregometry (LTA) is a gold standard platelet function assay. In this pilot study, we used LTA to personalize ASA therapy ex vivo in atherosclerotic patients. Patients were recruited who were on 81 mg ASA, presenting to ambulatory clinics at St. Michael’s Hospital (n = 64), with evidence of atherosclerotic disease defined as clinical symptoms and diagnostic findings indicative of symptomatic peripheral arterial disease (PAD), with an ankle brachial index (ABI) of <0.9 (n = 52) or had diagnostic features of asymptomatic carotid arterial stenosis (CAS), with >50% stenosis of internal carotid artery on duplex ultrasound (n = 12). ASA compliance was assessed via multisegmented injection-capillary electrophoresis-mass spectrometry based on measuring the predominant urinary ASA metabolite, salicyluric acid. LTA with arachidonic acid was used to test for ASA sensitivity. Escalating ASA dosages of 162 mg and 325 mg were investigated ex vivo for ASA dose personalization. Of the 64 atherosclerotic patients recruited, 8 patients (13%) were non-compliant with ASA. Of ASA compliant patients (n = 56), 9 patients (14%) were non-sensitive to their 81 mg ASA dosage. Personalizing ASA therapy in 81 mg ASA non-sensitive patients with escalating dosages of ASA demonstrated that 6 patients became sensitive to a dosage equivalent to 162 mg ASA and 3 patients became sensitive to a dosage equivalent to 325 mg ASA. We were able to personalize ASA dosage ex vivo in all ASA non-sensitive patients with escalating dosages of ASA within 1 h of testing. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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8 pages, 512 KiB

Open AccessArticle

Cost Consequences for the NHS of Using a Two-Step Testing Method for the Detection of Clostridium difficile with a Point of Care, Polymerase Chain Reaction Test as the First Step

by William S. Jones, Stephen Rice, H. Michael Power, Gregory Maniatopoulos, Jana Suklan, Fiona Beyer, Mark H. Wilcox, Michelle Permain, A. John Simpson, D. Ashley Price and A. Joy Allen

Diagnostics 2020, 10(10), 819; https://doi.org/10.3390/diagnostics10100819 - 14 Oct 2020

Viewed by 2170

Abstract

Clostridium difficile infection (CDI) is a common healthcare-associated infection. Current practice for diagnosing CDI in the Newcastle upon Tyne Hospitals NHS Foundation Trust involves a three-step, laboratory testing strategy using glutamate dehydrogenase (GDH) enzyme immunoassay (EIA), followed by a polymerase chain reaction (PCR) [...] Read more.

Clostridium difficile infection (CDI) is a common healthcare-associated infection. Current practice for diagnosing CDI in the Newcastle upon Tyne Hospitals NHS Foundation Trust involves a three-step, laboratory testing strategy using glutamate dehydrogenase (GDH) enzyme immunoassay (EIA), followed by a polymerase chain reaction (PCR) test then a toxin EIA. However, a PCR point of care test (POCT) for the C. difficile tcdB gene for screening suspected CDI cases, may provide a more efficient way of facilitating an equally effective, two-step, testing strategy with a toxin EIA. This study evaluated the cost consequences of changing from the three-step to a two-step testing strategy. A cost-consequences model was developed to compare the costs and consequences of the two strategies. Uncertainties in the model inputs were investigated with one- and two-way sensitivity analysis. The two-step, POCT strategy was estimated to save £283,282 per 1000 hospitalized NHS patients with suspected infectious diarrhea. Sensitivity analysis indicated that the turnaround time for the POCT was the largest driver for cost savings. Providing the POCT has sufficiently high diagnostic accuracy for detecting C. difficile, the two-step, POCT strategy for CDI identification is likely to be cost saving for NHS hospitals with an offsite laboratory. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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14 pages, 2603 KiB

Open AccessArticle

Development of a Nucleic Acid Lateral Flow Immunoassay for the Detection of Human Polyomavirus BK

by Yi-Huei Huang, Kuan-Yi Yu, Shou-Ping Huang, Hui-Wen Chuang, Wen-Zhi Lin, Juin-Hong Cherng, Yao-Wen Hung, Ming-Kung Yeh, Po-Da Hong and Cheng-Che Liu

Diagnostics 2020, 10(6), 403; https://doi.org/10.3390/diagnostics10060403 - 12 Jun 2020

Cited by 7 | Viewed by 4738

Abstract

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The [...] Read more.

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The lateral flow assay, a rapid, low-cost, minimal-labor, and easy-to-use diagnostic method, was successfully applied for pathogen detection. In this study, we used oligonucleotide probes to develop a simple and rapid sandwich-type lateral flow immunoassay for detecting BKV DNA within 45 minutes. The detection limit for the synthetic single-stranded DNA was 5 nM. The specificity study showed no cross-reactivity with other polyomaviruses, such as JC virus and simian virus 40. For the Escherichia coli containing BKV plasmid cultured samples, the sensitivity was determined to be 10⁷ copies/mL. The approach offers great potential for BKV detection of various target analytes in point-of-care settings. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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8 pages, 1461 KiB

Open AccessArticle

Multiplex Point-of-Care Tests for the Determination of Antibodies after Acellular Pertussis Vaccination

by Aapo Knuutila, Carita Rautanen, Jussi Mertsola and Qiushui He

Diagnostics 2020, 10(4), 187; https://doi.org/10.3390/diagnostics10040187 - 27 Mar 2020

Cited by 2 | Viewed by 2531

Abstract

Most of the current serological diagnosis of pertussis is based on pertussis toxin (PT) IgG antibodies and does not differentiate between vaccination and infection-induced antibodies. PT is included in all of acellular pertussis vaccines available in the world. Multiplex testing of non-vaccine antigen-related [...] Read more.

Most of the current serological diagnosis of pertussis is based on pertussis toxin (PT) IgG antibodies and does not differentiate between vaccination and infection-induced antibodies. PT is included in all of acellular pertussis vaccines available in the world. Multiplex testing of non-vaccine antigen-related antibodies has the potential to improve the diagnostic outcome of these assays. In this study, we developed a quantitatively spatial multiplex lateral flow immunoassay (LFIA) for the detection of IgG antibodies directed against PT, pertactin (PRN), and filamentous hemagglutinin (FHA). The assay was evaluated with serum samples with varying anti-PT, anti-PRN, and anti-FHA IgG levels and the result was compared to those obtained with standardized ELISA. The developed assay showed good specificity with PT and PRN antibodies and semiquantification throughout the antigen combinations. This exploratory study indicates that the multiplex LFIA is specific and sensitive, and a similar test platform with alternative antigens could be suitable for new type of pertussis serology. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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35 pages, 13855 KiB

Open AccessArticle

A Pervasive Healthcare System for COPD Patients

by Hicham Ajami, Hamid Mcheick and Karam Mustapha

Diagnostics 2019, 9(4), 135; https://doi.org/10.3390/diagnostics9040135 - 01 Oct 2019

Cited by 8 | Viewed by 5753

Abstract

Chronic obstructive pulmonary disease (COPD) is one of the most severe public health problems worldwide. Pervasive computing technology creates a new opportunity to redesign the traditional pattern of medical system. While many pervasive healthcare systems are currently found in the literature, there is [...] Read more.

Chronic obstructive pulmonary disease (COPD) is one of the most severe public health problems worldwide. Pervasive computing technology creates a new opportunity to redesign the traditional pattern of medical system. While many pervasive healthcare systems are currently found in the literature, there is little published research on the effectiveness of these paradigms in the medical context. This paper designs and validates a rule-based ontology framework for COPD patients. Unlike conventional systems, this work presents a new vision of telemedicine and remote care solutions that will promote individual self-management and autonomy for COPD patients through an advanced decision-making technique. Rules accuracy estimates were 89% for monitoring vital signs, and environmental factors, and 87% for nutrition facts, and physical activities. Full article

(This article belongs to the Special Issue Trends in Multiplex and Smart Technologies for In Vitro Diagnostics and Point-of-Care Testing)

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