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1.
J Virol Methods ; 290: 114066, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33453300

RESUMO

A duplex SYBR Green I-based real-time PCR assay was established for the simultaneous detection of canine kobuvirus (CaKoV) and canine astrovirus (CaAstV). This assay can easily distinguish the two viruses according to their different melting temperatures (Tm) of 80 °C for CaKoV and 86.5 °C for CaAstV; other canine enteroviruses used as controls showed no specific melting peaks. The detection limit of this assay was determined to be 101 copies/µL for both viruses. This method exhibited high repeatability and reproducibility, with a coefficient of variation less than 1.5 %. A total of 48 fecal samples were collected for clinical testing by real-time PCR and confirmed by sequencing. Real-time PCR assay showed a 10.4 % CaKoV-positive rate and a 4.2 % CaAstV-positive rate, and the positive rate of co-infection of the two viruses was 2.1 %, which was consistent with the sequencing results. This assay has many advantages over conventional PCR: it is rapid, sensitive, specific, and reliable for detecting these two viruses in one sample, and it can be used as a tool to detect CaKoV and CaAstV infection or co-infection in clinical settings.

2.
Biomed Opt Express ; 11(11): 6458-6469, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33282501

RESUMO

In this study, an indocyanine green (ICG)-based dynamic contrast- enhanced fluorescence imaging (DCE-FI) technique was evaluated as a method to provide objective real-time data on bone perfusion using a porcine osteotomy model. DCE-FI with sequentially increasing injury to osseous blood supply was performed in 12 porcine tibias. There were measurable, reproducible and predictable changes to DCE-FI data across each condition have been observed on simple kinetic curve-derived variables as well variables derived from a novel bone-specific kinetic model. The best accuracy, sensitivity and specificity of 89%, 88% and 90%, have been achieved to effectively differentiate injured from normal/healthy bone.

3.
Opt Lett ; 45(22): 6130-6133, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33186932

RESUMO

Cherenkov light induced from megavolt (MV) X-rays during external beam radiotherapy serves as an internal light source to excite phosphors or fluorophores within biological tissues for molecular imaging. The broad spectrum of Cherenkov light leads to significant spectral overlap with any luminescence emission and, to overcome this problem, a single pixel hyperspectral imaging methodology was demonstrated here by coupling the detection with light sheet scanning and filtered back projection reconstruction of hyperspectral images. Thin scanned sheets of MV X-rays produce Cherenkov light to illuminate the planes deep within the tissue-simulating media. A fluorescence probe was excited by Cherenkov light, and a complete hyperspectral sinogram of the data was obtained through translation and rotation of the beam. Hyperspectral 2D images finally were reconstructed. Through this approach of spectral unmixing, it was possible to resolve hyperspectral images of both the Cherenkov and resulting fluorescence intensity from molecular sensors.

4.
J Virol Methods ; 288: 114012, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33157149

RESUMO

In this study, a SYBR Green I-based real-time reverse transcription-polymerase chain reaction (RT-PCR) was developed for the clinical diagnosis of feline astroviruses (FeAstVs). Specific primers were designed based on the conserved region of the FeAstV ORF1b gene. Experiments for specificity, sensitivity, and repeatability of the assay were carried out. In addition, the assay was evaluated using clinical samples. Specificity analysis indicated that the assay showed negative results with samples of Feline Parvovirus, Feline Herpesvirus, Feline Calicivirus, Feline Bocavirus, and Feline Coronavirus, indicating good specificity of the assay. Sensitivity analysis showed that the SYBR Green I-based real-time RT-PCR method could detect as low as 3.72 × 101 copies/µL of template, which is 100-fold more sensitive compared to the conventional RT-PCR. Both intra-assay and inter-assay variability were lower than 1 %, indicating good reproducibility. Furthermore, an analysis of 150 fecal samples showed that the positive detection rate of SYBR Green I-based real-time RT-PCR was higher than that of the conventional RT-PCR, indicating the high reliability of the method. The assay is cheap and effective. Therefore, it could provide support for the detection of FeAstV in large-scale clinical testing and epidemiological investigation.

5.
J Biomed Opt ; 25(11)2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33236619

RESUMO

SIGNIFICANCE: The necessity to use exogenous probes for optical oxygen measurements in radiotherapy poses challenges for clinical applications. Options for implantable probe biotechnology need to be improved to alleviate toxicity concerns in human use and facilitate translation to clinical trial use. AIM: To develop an implantable oxygen sensor containing a phosphorescent oxygen probe such that the overall administered dose of the probe would be below the Federal Drug Administration (FDA)-prescribed microdose level, and the sensor would provide local high-intensity signal for longitudinal measurements of tissue pO2. APPROACH: PtG4, an oxygen quenched dendritic molecule, was mixed into an agarose matrix at 100 µM concentration, allowing for local injection into tumors at the total dose of 10 nmol per animal, forming a gel at the site of injection. Cherenkov-excited luminescence imaging (CELI) was used to acquire the phosphorescence and provide intratumoral pO2. RESULTS: Although PtG4 does not form covalent bonds with agarose and gradually leaches out into the surrounding tissue, its retention time within the gel was sufficiently long to demonstrate the capability to measure intratumoral pO2 with the implantable gel sensors. The sensor's performance was first evaluated in vitro in tissue simulation phantoms, and then the sensor was used to measure changes in oxygen in MDA-MB-231 tumors during hypofractionated radiotherapy. CONCLUSIONS: Our study demonstrates that implantable oxygen sensors in combination with CELI present a promising approach for quantifying oxygen changes during the course of radiation therapy and thus for evaluating the tumor response to radiation. By improving the design of the gel-probe composition in order to prevent leaching of the probe into the tissue, biosensors can be created that should allow longitudinal oxygen measurements in tumors by means of CELI while using FDA-compliant microdose levels of the probe and thus lowering toxicity concerns.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33002542

RESUMO

PURPOSE: The extreme microscopic heterogeneity of tumors makes it difficult to characterize tumor hypoxia. We evaluated how changes in the spatial resolution of oxygen imaging could alter measures of tumor hypoxia and their correlation to radiation therapy response. METHODS AND MATERIALS: Cherenkov-Excited Luminescence Imaging (CELI) in combination with an oxygen probe, Oxyphor PtG4 was used to directly image tumor pO2 distributions with 0.2 mm spatial resolution at the time of radiation delivery. These pO2 images were analyzed with variations of reduced spatial resolution from 0.2 mm to 5 mm, to investigate the influence of how reduced imaging spatial resolution would affect the observed tumor hypoxia. As an in vivo validation test, mice bearing tumor xenografts were imaged for hypoxic fraction and median pO2 to examine the predictive link with tumor response to radiation therapy, while accounting for spatial resolution. RESULTS: In transitioning from voxel sizes of 200 µm to 3mm, the median pO2 values increased by a few mmHg, while the hypoxic fraction decreased by more than 50%. When looking at radiation-responsive tumors, the median pO2 values changed just a few mmHg as a result of treatment, while the hypoxic fractions changed by as much as 50%. This latter change, however, could only be seen when sampling was performed with high spatial resolution. Median pO2 or similar quantities obtained from low resolution measurements are commonly used in clinical practice, however these parameters are much less sensitive to changes in the tumor microenvironment than the tumor hypoxic fraction obtained from high-resolution oxygen images. CONCLUSIONS: This study supports the hypothesis that for adequate measurements of the tumor response to radiation therapy, oxygen imaging with high spatial resolution is required in order to accurately characterize the hypoxic fraction.

7.
Infect Genet Evol ; 86: 104600, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33091576

RESUMO

Bufavirus is a novel virus associated with canine gastroenteritis. Three strains of bufavirus were first detected in dog feces collected from Anhui province in Eastern China. The near-complete genome sequences were amplified. Sequence alignment showed 98.3-99.5% homology between the three bufavirus strains and reference strains. Phylogenetic analysis showed the distributed viruses forming a cluster of close relationships. Selective pressure analysis of the VP2 region indicated that the canine bufavirus (CBuV) was mainly subject to negative selection during evolution. The negative selection site was located on the residue of B-cell epitopes, indicating minimal change to the virus's immunogenicity. Since this is the first report of CBuV circulating in Anhui Province, this study will provide further understanding of the phylogenetic and molecular characteristics of CBuV and serve as a reference for prevention and vaccine development.

8.
J Virol Methods ; 285: 113963, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32882322

RESUMO

Porcine circovirus 4 (PCV4) is a novel circovirus first discovered in China in April 2019. Here, we established an SYBR Green I-based real-time PCR for quantitative detection of PCV4. A pair of specific primers was designed based on the conserved region of Cap of PCV4. The standard curve of the established real-time PCR. assay showed a good linear relationship. The sensitivity of the established real-time PCR was 100 times greater than that of conventional PCR, and the detection limit of the assay was 3 × 101 copies. There was no cross-reactivity with other swine DNA viruses, showing good specificity. The intra-group variation coefficient was 0.37-0.78 %, and the inter-group variation coefficient was 0.57-0.94%, indicating that the assay has good repeatability. Moreover, the analysis of clinical samples showed that the positive detection rate of PCV4 was 10.71% (18/168), while that of conventional PCR was 8.93% (15/168). Interestingly, co-infection with PCV2 or PCV3, or both PCV2 and PCV3, was also detected. In conclusion, the established SYBR Green I-based real-time PCR may be a cost-effective and rapid method for PCV4 clinical diagnosis.

9.
Mol Cell Probes ; 54: 101666, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32919029

RESUMO

The similar clinical characteristics of canine circovirus (CaCV) and canine astrovirus (CaAstV) infections and high frequency of co-infection make diagnosis difficult. In this study, a duplex SYBR Green I-based real-time polymerase chain reaction (PCR) assay was established for the rapid, simultaneous detection of CaCV and CaAstV. Two pairs of specific primers were designed based on the Rep gene of CaCV and the Cap gene of CaAstV. By using the real-time PCR assay method, the two viruses can be distinguished by the difference in melting temperatures, 79 °C and 86 °C for CaCV and CaAstV, respectively. This assay had high specificity, showing no cross-reaction with other common canine viruses, as well as high sensitivity, with minimum detection limits of 9.25 × 101 copies/µL and 6.15 × 101 copies/µL for CaCV and CaAstV, respectively. Based on the mean coefficient of variation, the method had good reproducibility and reliability. In a clinical test of 57 fecal samples, the rates of positive detection by real-time PCR were 14.04% (8/57) and 12.28% (7/57) for CaCV and CaAstV, respectively, and the rate of co-infection was 8.77% (5/57). In conclusion, the newly established duplex SYBR Green I-based real-time PCR assay is sensitive, specific, reliable, and rapid and is an effective tool for the detection of co-infections with CaCV and CaAstV.

10.
ACS Appl Mater Interfaces ; 12(40): 44383-44392, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32914957

RESUMO

Concurrent chemoradiotherapy is used for advanced cancers, but the chemotherapy is dose limited by normal tissue toxicity. Localized X-ray activation of chemotherapy could overcome this, as studied here, with release from self-assembled nanomicelles (NMs) created from copolymers loaded with doxorubicin (DOX) having a photocleavable o-nitrobenzyl ester (o-Ne) group. The micelles demonstrated release of DOX from X-ray-induced Cherenkov light and conversion from a caged hydrophobic form to hydrophilic DOX, which achieves nuclear localization. Folate on the exterior of the NMs directed them for effective intracellular uptake prior to irradiation. Irradiation with 8 Gy released the DOX, which then entered the cell nucleus, providing near-complete in vivo tumor eradication and negligible off-target organ damage. Micelles were assembled from molecular component materials that are commonly in human use. This study realizes triple targeting in chemoradiation with potential for cell-receptor-mediated uptake, localized radiotherapy activation, and nuclear relocalization, all leading to limited off-target toxicity.

11.
J Biomed Opt ; 25(8)2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32869567

RESUMO

SIGNIFICANCE: Extremity injury represents the leading cause of trauma hospitalizations among adults under the age of 65 years, and long-term impairments are often substantial. Restoring function depends, in large part, on bone and soft tissue healing. Thus, decisions around treatment strategy are based on assessment of the healing potential of injured bone and/or soft tissue. However, at the present, this assessment is based on subjective clinical clues and/or cadaveric studies without any objective measure. Optical imaging is an ideal method to solve several of these issues. AIM: The aim is to highlight the current challenges in assessing bone and tissue perfusion/viability and the potentially high impact applications for optical imaging in orthopaedic surgery. APPROACH: The prospective will review the current challenges faced by the orthopaedic surgeon and briefly discuss optical imaging tools that have been published. With this in mind, it will suggest key research areas that could be evolved to help make surgical assessments more objective and quantitative. RESULTS: Orthopaedic surgical procedures should benefit from incorporation of methods to measure functional blood perfusion or tissue metabolism. The types of measurements though can vary in the depth of tissue sampled, with some being quite superficial and others sensing several millimeters into the tissue. Most of these intrasurgical imaging tools represent an ideal way to improve surgical treatment of orthopaedic injuries due to their inherent point-of-care use and their compatibility with real-time management. CONCLUSION: While there are several optical measurements to directly measure bone function, the choice of tools can determine also the signal strength and depth of sampling. For orthopaedic surgery, real-time data regarding bone and tissue perfusion should lead to more effective patient-specific management of common orthopaedic conditions, requiring deeper penetrance commonly seen with indocyanine green imaging. This will lower morbidity and result in decreased variability associated with how these conditions are managed.

12.
Mol Cell Probes ; 53: 101648, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32798710

RESUMO

Beak atrophy and dwarfism syndrome (BADS) is commonly caused by co-infection with duck circovirus (DuCV) and novel goose parvovirus (NGPV). Therefore, concurrent detection of both viruses is important for monitoring and limiting BADS, although such a diagnostic test has not been reported. In this study, we developed a duplex, SYBR Green I-based real-time polymerase chain reaction (PCR) assay to enable the simultaneous detection of DuCV and NGPV. The assay readily distinguished between the two viruses, based on their different melting temperatures (Tm), where the Tm for DuCV was 80 °C and that for NGPV was 84.5 °C. Other non-target duck viruses that were tested did not show melting peaks. The detection limit of the duplex assay was 101 copies/µL for both viruses. This method exhibited high repeatability and reproducibility, and both the inter-assay and intra-assay variation coefficients were <1.6%. Thirty-one fecal samples were collected for clinical testing using real-time PCR analysis, and the results were confirmed using sequencing. The rate of co-infection was 6.5%, which was consistent with the sequencing results. This duplex real-time PCR assay offers advantages over other tests, such as rapid, sensitive, specific, and reliable detection of both viruses in a single sample, which enables the quantitative detection of DuCV and NGPV in clinical samples. Using this test may be instrumental in reducing the incidence of BADS and the associated economic losses in the duck and goose industries.

13.
Arch Virol ; 165(11): 2495-2501, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32776176

RESUMO

Canine kobuvirus (CaKoV), a newly described virus, is the causative agent of gastroenteritis in dogs. In this study, 57 fecal samples from dogs with diarrhea in Anhui Province, eastern China, were collected. Among these, five samples were identified to be infected with CaKoV, by polymerase chain reaction targeting the CaKoV 3D gene. The five CaKoV strains were subjected to phylogenetic analysis. The sequences of VP1 from the five CaKoV strains were 93.6%-96.1% identical to each other and 91.75%-97.95% identical to other reported CaKoV VP1 sequences. In addition, the complete genome of one strain was successfully amplified and sequenced. The genome consisted of 8223 nucleotides and shared 94.6%-97.0% nucleotide and 93.1%-94.0% amino acid sequence identity with other CaKoV isolates. Phylogenetic analysis revealed that the CaKoV strain from Anhui Province was similar to other Chinese strains, and it was more closely related to feline and mouse kobuviruses than to sheep and bovine kobuviruses. Interestingly, all of the CaKoV-positive samples were coinfected with canine parvovirus. The finding of CaKoV infection in dogs with diarrhea and coinfection with canine parvovirus are a cause for concern and highlight the need for management and preventive measures.


Assuntos
Doenças do Cão/epidemiologia , Kobuvirus/classificação , Kobuvirus/genética , Infecções por Picornaviridae/veterinária , Sequência de Aminoácidos , Animais , Sequência de Bases , China/epidemiologia , Diarreia/etiologia , Doenças do Cão/virologia , Cães/virologia , Fezes/virologia , Gastroenterite/epidemiologia , Gastroenterite/veterinária , Gastroenterite/virologia , Genes Virais , Parvovirus Canino/genética , Filogenia , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia
14.
Mol Cell Probes ; 53: 101647, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32777447

RESUMO

Feline bocavirus-1 (FBoV-1) was first discovered in Hong Kong in 2012, and studies have indicated that the virus may cause feline hemorrhagic enteritis. Currently, there is a lack of an effective and quantitative method for FBoV-1 detection. In this study, a TaqMan-based quantitative real-time PCR (qPCR) for FBoV-1 detection was established. Primers and probes were designed to target the conserved region of the FBoV-1 NS1 gene. The sensitivity analysis indicated that the minimum detection limit was 4.57 × 101 copies/µL. The specificity test revealed no cross-reaction with seven other common feline viruses, including the same species-FBoV-2 and FBoV-3. The sensitivity of this method was 100 times higher than that of conventional PCR (cPCR). The established method showed good repeatability, with the intra-assay and inter-assay coefficients of variation of 0.18%-1.00% and 0.27%-0.45%, respectively. Furthermore, the analysis of feline feces revealed that the detection rate by qPCR was 7.0% (9/128), whereas that by cPCR was 4.7% (6/128). In conclusion, the established qPCR assay can quantitatively detect FBoV-1 with a high sensitivity, high specificity, and good reproducibility, making it a promising technique for the clinical detection of and basic and epidemiological research on FBoV-1.

15.
3 Biotech ; 10(8): 354, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32766095

RESUMO

This study aimed to explore the phylogenetic and molecular characteristics of feline astrovirus. A total of 33 fecal samples of domestic cats with or without diarrhea were collected from the Anhui province, and two positive samples were detected. The complete genome and ORF2 of the two strains were sequenced and phylogenetically analyzed. AH-1-2020 and AH-2-2020 displayed 83.4% homology, and their homologies with other reference strains were 75.3%-83.4% and 83.4%-95.0%, respectively. Phylogenetic tree analysis revealed that all strains could be classified into three different clusters; therefore, the mean amino acid genetic distances (p-dist) among the three clusters were estimated. The results suggested that the two strains and other FeAstV strains were grouped into three genotypes, with AH-1-2020 belonging to a novel genotype. High similarity was observed (65.9%-66.5% nucleotide identity and 63.8%-64.8% amino acid identity) in ORF2 between porcine astrovirus type 1 and AH-1-2020. Furthermore, inter-specific recombination between porcine astrovirus type 1 and FeAstV was observed. We, therefore, inferred that inter-specific transmission may exist between pigs and cats; however, further studies are required to verify this. This is the first report on the genetic characterization and phylogenetic analysis of FeAstVs in the Anhui province and would further the current understanding of the genetic diversity and epidemiology of FeAstVs.

16.
J Virol Methods ; 285: 113944, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32730841

RESUMO

Canine kobuvirus (CaKoV) is a causative agent of gastroenteritis in dogs. Rapid detection of CaKoV is important for preventing and controlling this condition. In this study, an SYBR Green I-based quantitative real-time PCR assay was established for CaKoV detection. Specific primers targeting a highly conserved region of the CaKoV 3D gene were developed. After optimization, the method detected a minimum of 1 × 101 copies/µL with high specificity, stability, and repeatability. Moreover, the entire process only required approximately 1.5 h for completion. Our results were supported by those obtained for clinical samples, in which our developed method was successfully applied. The newly established real-time PCR is a rapid, sensitive, specific, and repeatable method for the quantitative detection of CaKoV and can, therefore, be used in epidemiological studies.

17.
Opt Lett ; 45(13): 3761-3764, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32630948

RESUMO

Fluorescence imaging is severely limited by the background and autofluorescence of tissues for in vivo detection of circulating tumor cells (CTCs). Time-gated luminescence (TGL) imaging, in combination with luminescent probes that possess hundreds of microsecond emission lifetimes, can be used to effectively suppress this background, which has predominantly nanosecond lifetimes. This Letter demonstrates the feasibility of TGL imaging using luminescent probes for the in vivo real time imaging and tracking of single CTCs circulating freely in the blood vessels with higher accuracy given by substantially higher signal-to-noise ratio. The luminescent probe used in this Letter was a commercial Eu3+ chelate (EuC) nanosphere with a super-long lifetime of near 800 µs, which enabled TGL imaging to achieve background-free detection with ∼5 times higher SNR versus steady state. Phantom and in vivo mouse studies indicated that EuC labeled tumor cells moving in medium or bloodstream at the speed of 1-2 mm/s could be captured in real time.

18.
Gene ; 756: 144898, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32569721

RESUMO

Goose astrovirus (GAstV) causes a novel disease characterized by urate deposition in the viscera and joints in goslings in many provinces of China, leading to huge economic losses in the goose industry. To better understand the genetic diversity of GAstV in the Anhui Province, Central-Eastern China, 48 kidney samples from goslings with gout were subjected to reverse-transcription polymerase chain reaction (RT-PCR) analysis for detecting GAstV, and phylogenetic analysis of whole genomes and ORFs was performed. Thirty-five samples were GAstV-positive, indicating that the virus is a frequent cause of gout. The whole genomes of 5 GAstV strains were successfully sequenced and named AHAU1-5. The sequenced genomes and those of reference GAstV strains in GenBank displayed 97.4-99.8% similarity. The isolates had high nucleotide sequence similarity with the GAstV reference strain SDPY. A phylogenetic analysis showed that AHAU1 and AHAU4 were closely related to the reference strain SDPY; AHAU2, AHAU3, and AHAU5 formed separate branches. Furthermore, recombination analysis revealed putative recombination sites in the Jiangsu strains that originated from strains in the Anhui and Shandong Provinces, accompanied by the recombination of different strains in the Anhui Province. This study is the first to carry out systematic phylogenetic analysis of GAstV isolated in the Anhui Province, Central-Eastern China. By improving our understanding of the diversity of GAstV in the Anhui Province, these results provide a basis for the prevention and control of its spread.


Assuntos
Infecções por Astroviridae/veterinária , Astroviridae/genética , Astroviridae/isolamento & purificação , Gansos , Doenças das Aves Domésticas/virologia , RNA Viral/genética , Animais , Astroviridae/classificação , Infecções por Astroviridae/virologia , China , Genoma Viral , Gota/veterinária , Gota/virologia , Filogenia , Análise de Sequência de RNA
19.
J Biomed Opt ; 25(6): 1-14, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32519522

RESUMO

SIGNIFICANCE: The effects of varying the indocyanine green injection dose, injection rate, physiologic dispersion of dye, and intravenous tubing volume propagate into the shape and magnitude of the arterial input function (AIF) during intraoperative fluorescence perfusion assessment, thereby altering the observed kinetics of the fluorescence images in vivo. AIM: Numerical simulations are used to demonstrate the effect of AIF on metrics derived from tissue concentration curves such as peak fluorescence, time-to-peak (TTP), and egress slope. APPROACH: Forward models of tissue concentration were produced by convolving simulated AIFs with the adiabatic approximation to the tissue homogeneity model using input parameters representing six different tissue examples (normal brain, glioma, normal skin, ischemic skin, normal bone, and osteonecrosis). RESULTS: The results show that AIF perturbations result in variations in estimates of total intensity of up to 80% and TTP error of up to 200%, with the errors more dominant in brain, less in skin, and less in bone. Interestingly, error in ingress slope was as high as 60% across all tissue types. These are key observable parameters used in fluorescence imaging either implicitly by viewing the image or explicitly through intensity fitting algorithms. Correcting by deconvolving the image with a measured subject-specific AIF provides an intuitive means of visualizing the data while also removing the source of variance and allowing intra- and intersubject comparisons. CONCLUSIONS: These results suggest that intraoperative fluorescence perfusion assessment should be corrected by patient-specific AIFs measured by pulse dye densitometry.

20.
Artigo em Inglês | MEDLINE | ID: mdl-32483397

RESUMO

Due to the lack of objectively measurable or quantifiable methods to assess the bone perfusion, the success of removing devitalized bone is based almost entirely on surgeon's experience and varies widely across surgeons and centers. In this study, an indocyanine green (ICG)-based dynamic contrast-enhanced fluorescence imaging (DCE-FI) has been developed to objectively assess bone perfusion and guide surgical debridement. A porcine trauma model (n = 6 pigs × 2 legs) with up to 5 conditions of severity in loss of flow in each, was imaged by a commercial fluorescence imaging system. By applying the bone-specific hybrid plug-compartment (HyPC) kinetic model to four-minute video sequences, the perfusion-related metrics, such as peak intensity, total bone blood flow (TBBF) and endosteal bone blood flow to TBBF fraction (EFF) were calculated. The results shown that the combination of TBBF and EFF can effectively differentiate injured from normal bone with the accuracy, sensitivity and specificity of 89%, 88% and 90%, respectively. Our subsequent first in human bone blood flow imaging study confirmed DCE-FI can be successfully translated into human orthopaedic trauma patients.

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