Deposition of beta-amyloid (Aβ) deposits is one major histopathological hallmark of Alzheimer's disease (AD). Here, we introduce volumetric multi-spectral optoacoustic tomography (vMSOT), which covers 10×10×10 mm 3 field-of-view, capable of 3D whole mouse brain imaging. We show for the first time the optoacoustic properties of oxazine-derivative AOI987 probe, which binds to Aβ, and the application of vMSOT for the quantification of brainwide Aβ deposition. Administration of AOI987 to two common transgenic mouse strains of AD amyloidosis led to a retention of the probe in Aβ-laden brain regions. Co-registered of vMSOT data to a brain atlas revealed strain-specific pattern of AOI987 uptake. A comparison with ex vivo light-sheet microscopy in cleared mouse brains showed a good correspondence in Aβ distribution. Lastly, we demonstrate the specificity of the AOI987 probe by immunohistochemistry. vMSOT with AOI987 facilitates preclinical brain region-specific studies of Aβ spread and accumulation, and the monitoring of putative treatments targeting Aβ.

BackgroundThe World Health Organization has recommended at least four antenatal care (ANC) visits and skilled attendants at birth. Most pregnant women in rural communities in low-income countries do not achieve the minimum recommended visits and deliver without skilled attendants. With the aim of increasing number of ANC visits, reducing home deliveries, and supplementing care given by ANC clinics, a proposed system based on low-cost mobile phones and portable ultrasound scan machines was piloted.MethodsA sample of 323 pregnant women from four rural communities in the Central Region of Ghana were followed within a 11-month project. In each community, at least one health worker was trained and equipped with a mobile phone to promote ANC and hospital deliveries in her own community. If women cannot attend ANC, technicians acquired scans by using portable ultrasound machines in her community directly and sent them almost in real time to be analyzed by a gynecologist in an urban hospital. A preliminary survey to assess ANC status preceding the pilot study was conducted. During this, one hundred women who had had pregnancies within five years prior to the study were interviewed.ResultsThe preliminary survey showed that women who attended ANC were less likely to have a miscarriage and more likely to have delivery at hospital or clinic than those who did not, and women who attained at least four ANC visits were less likely to practice self-medication. Among the women involved in the project, 40 gave birth during the period of observation. The proposed prenatal care approach showed that 62.5 % of pregnant women who gave birth during the observation period included in the project (n=40) had their labor attended in clinics or hospitals as against 37.5 % among the cases reported in the pre-survey. One case of ectopic and two cases of breech pregnancies were detected during the pilot through the proposed approach, and appropriate medical interventions were sought.ConclusionOur results show that the proposed prenatal care approach can make quality ANC accessible in rural communities where pregnant women have not been able to access proper ANC.

Figure S1. Distribution of global network metrics for controls, MCI and AD subjects, combined. Shortcuts stand for; Louvain: Louvain modularity, global_eff: global effeciency, and char_path_len: characteristic path length i/vi ii/vi iii/vi