Animal Models of Diabetic Retinopathy Olivares, Ana Maria; Althoff, Kristen; Chen, Gloria Fanghua ...
Current diabetes reports,
10/2017, Volume:
17, Issue:
10
Journal Article
Peer reviewed
Open access
Purpose of Review
Diabetic retinopathy (DR) is one of the most common complications associated with chronic hyperglycemia seen in patients with diabetes mellitus. While many facets of DR are still ...not fully understood, animal studies have contributed significantly to understanding the etiology and progression of human DR. This review provides a comprehensive discussion of the induced and genetic DR models in different species and the advantages and disadvantages of each model.
Recent Findings
Rodents are the most commonly used models, though dogs develop the most similar morphological retinal lesions as those seen in humans, and pigs and zebrafish have similar vasculature and retinal structures to humans. Nonhuman primates can also develop diabetes mellitus spontaneously or have focal lesions induced to simulate retinal neovascular disease observed in individuals with DR.
Summary
DR results in vascular changes and dysfunction of the neural, glial, and pancreatic β cells. Currently, no model completely recapitulates the full pathophysiology of neuronal and vascular changes that occur at each stage of diabetic retinopathy; however, each model recapitulates many of the disease phenotypes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
To describe the prevalence of diagnosed depression, anxiety, bipolar disorder, and schizophrenia in people with HIV (PWH) and the differences in HIV care continuum outcomes in those with and without ...mental health disorders (MHDs).
Observational study of participants in the North American AIDS Cohort Collaboration on Research and Design.
PWH (≥18 years) contributed data on prevalent schizophrenia, anxiety, depressive, and bipolar disorders from 2008 to 2018 based on International Classification of Diseases code mapping. Mental health (MH) multimorbidity was defined as having two or more MHD. Log binomial models with generalized estimating equations estimated adjusted prevalence ratios (aPR) and 95% confidence intervals for retention in care (≥1 visit/year) and viral suppression (HIV RNA ≤200 copies/ml) by presence vs. absence of each MHD between 2016 and 2018.
Among 122 896 PWH, 67 643 (55.1%) were diagnosed with one or more MHD: 39% with depressive disorders, 28% with anxiety disorders, 10% with bipolar disorder, and 5% with schizophrenia. The prevalence of depressive and anxiety disorders increased between 2008 and 2018, whereas bipolar disorder and schizophrenia remained stable. MH multimorbidity affected 24% of PWH. From 2016 to 2018 (N = 64 684), retention in care was marginally lower among PWH with depression or anxiety, however those with MH multimorbidity were more likely to be retained in care. PWH with bipolar disorder had marginally lower prevalence of viral suppression (aPR = 0.98 0.98-0.99) as did PWH with MH multimorbidity (aPR = 0.99 0.99-1.00) compared with PWH without MHD.
The prevalence of MHD among PWH was high, including MH multimorbidity. Although retention and viral suppression were similar to people without MHD, viral suppression was lower in those with bipolar disorder and MH multimorbidity.
Measurements of the cochlear duct length (CDL) are dependent on the resolution of the imaging dataset.
Previous research has shown highly precise cochlear measurements using 3D-curved multiplanar ...reconstruction (MPR) and flat-panel volume computed tomography (fpVCT). Thus far, however, there has been no systematic evaluation of the imaging dataset resolution required for optimal CDL measurement. Therefore, the aim of this study was to evaluate the dependence of CDL measurement on the resolution of the imaging dataset to establish a benchmark for future CDL measurements.
fpVCT scans of 10 human petrous bone specimens were performed. CDL was measured using 3D-curved MPR with secondary reconstruction of the fpVCT scans (fpVCT SECO ) and increasing resolution from 466 to 99 μm. In addition, intraobserver variability was evaluated. A best-fit function for calculation of the CDL was developed to provide a valid tool when there are no measurements done with high-resolution imaging datasets.
Comparison of different imaging resolution settings showed significant differences for CDL measurement in most of the tested groups ( p < 0.05), except for the two groups with the highest resolution. Imaging datasets with a resolution lower than 200 μm showed lower intraobserver variability than the other resolution settings, although there were no clinically unacceptable errors with respect to the Bland-Altman plots. The developed best-fit function showed high accuracy for CDL calculation using resolution imaging datasets of 300 μm or lower.
3D-curved MPR in fpVCT with a resolution of the imaging dataset of 200 μm or higher revealed the most precise CDL measurement. There was no benefit of using a resolution higher than 200 μm with regard to the accuracy of the CDL measurement.
Flat-panel volume computed tomography (fpVCT) and secondary reconstruction allow for more accurate measurements of two-turn length (2TL), cochlear duct length (CDL), and angular length (AL).
Cochlear ...geometry is a controversially debated topic. In the meantime, there are many different studies partly reporting highly divergent values. Our aim is to discuss the differences and to propose a radiological possibility to improve cochlear measurements using 3D-curved multiplanar reconstruction and fpVCT.
Performing different image modalities and settings, we tried to find a clinically usable option that allows for a high degree of accuracy. Therefore, we tested them against reference values of high-definition micro-computed tomography.
Comparison of 99 μm slice thickness secondary reconstruction of fpVCT and reference showed no significant differences for 2TL and CDL (p ≥ 0.05). Accordingly, ICC (intraclass correlation) values were excellent (ICC ≥ 0.75; lower limit of confidence interval CI ≥ 0.75; Cronbach's alpha α ≥ 0.9). Evaluating AL, there was a significant difference (difference: -17.27°; p = 0.002). The lower limit of the CI of the ICC was unacceptable (ICC = 0.944; lower limit of CI = 0.248; α = 0.990). Regarding the Bland-Altman plots, there were no clinically unacceptable errors, but a systematic underestimation of AL.
Secondary reconstruction is a suitable tool for producing reliable data that allow the accurate measurement of 2TL and CDL. The option of generating these reconstructions from raw data limits the need for higher radiation doses. Nevertheless, there is an underestimation of AL using secondary reconstructions.
The cochlear aqueduct (CA), which connects the scala tympani and the subarachnoid space, and its accompanying structures appear to have a significant relevance during cochlear implantation and an ...accurate visualization in clinical imaging is of great interest.
This study aims to determine which potential and limitations clinically available imaging modalities have in the visualization of the CA.
Micro-CT, flat-panel volume computed tomography with and without secondary reconstruction (fpVCT, fpVCTseco) and multislice computed tomography (MSCT) of 10 temporal bone specimen were used for 3D analysis of the CA.
FpVCTseco proved superior in visualizing the associated structures and lateral portions of the CA, which merge into the basal turn of the cochlea. All clinical imaging modalities proved equal in analyzing the length, total volume of the CA and its area of the medial orifice.
The choice of the most accurate clinical imaging modality to evaluate the CA and its associated structures depends on the clinical or scientific question. Furthermore, this study should provide a basis for further investigations analyzing the CA.
Improved radiological examinations with newly developed 3D models may increase understanding of Meniere's disease (MD). The morphology and course of the vestibular aqueduct (VA) in the temporal bone ...might be related to the severity of MD. The presented study explored, if the VA of MD and non-MD patients can be grouped relative to its angle to the semicircular canals (SCC) and length using a 3D model. Scans of temporal bone specimens (TBS) were performed using micro-CT and micro flat panel volume computed tomography (mfpVCT). Furthermore, scans were carried out in patients and TBS by computed tomography (CT). The angle between the VA and the three SCC, as well as the length of the VA were measured. From these data, a 3D model was constructed to develop the vestibular aqueduct score (VAS). Using different imaging modalities it was demonstrated that angle measurements of the VA are reliable and can be effectively used for detailed diagnostic investigation. To test the clinical relevance, the VAS was applied on MD and on non-MD patients. Length and angle values from MD patients differed from non-MD patients. In MD patients, significantly higher numbers of VAs could be assigned to a distinct group of the VAS. In addition, it was tested, whether the outcome of a treatment option for MD can be correlated to the VAS.
There is still a lack in precise postoperative evaluation of the cochlea because of strong artifacts. This study aimed to improve accuracy of postoperative two-turn (2TL) and cochlear duct length ...(CDL) measurements by applying flat-panel volume computed tomography (fpVCT), secondary reconstruction (fpVCT
SECO
) and three-dimensional curved multiplanar reconstruction.
First, 10 temporal bone specimens with or without electrode were measured in multi-slice computed tomography (MSCT), fpVCT and fpVCT
SECO
and compared to high-resolution micro-CT scans. Later, pre- and postoperative scans of 10 patients were analyzed in a clinical setting.
Concerning 2TL, no statistically significant difference was observed between implanted fpVCT
SECO
and nonimplanted micro-CT in 10 temporal bone specimens. In contrast, there was a significant discrepancy for CDL (difference: −0.7 mm, P = 0.004). Nevertheless, there were no clinically unacceptable errors (±1.5 mm). These results could be confirmed in a clinical setting. Using fpVCT
SECO
, CDL was slightly underestimated postoperatively (difference: −0.5 mm, P = 0.002) but without any clinically unacceptable errors.
fpVCT
SECO
can be successfully applied for a precise measurement of the cochlear lengths pre- and postoperatively. However, users must be aware of a slight systematic underestimation of CDL postoperatively. These results may help to refine electrode selection and frequency mapping.
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IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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