Current approaches and advances in the imaging of stroke

ABSTRACT A stroke occurs when the blood flow to the brain is suddenly interrupted, depriving brain cells of oxygen and glucose and leading to further cell death. Neuroimaging techniques, such as computed tomography and magnetic resonance imaging, have greatly improved our ability to visualise brain structures and are routinely used to diagnose the affected vascular region of a stroke patient's brain and to inform decisions about clinical care. Currently, these multimodal imaging techniques are the backbone of the clinical management of stroke patients and have immensely improved our ability to visualise brain structures. Here, we review recent developments in the field of neuroimaging and discuss how different imaging techniques are used in the diagnosis, prognosis and treatment of stroke.

Characterisation of Regional Human Meniscal Progenitor Cells

Background The surgical treatment of meniscus injury has represented a clinical challenge for decades. Stimulating meniscus regeneration using transplanted meniscal progenitor cells has been suggested as a promising new strategy. However, there is a lack of studies which decisively identify and characterise progenitor cell populations in human meniscus tissues. Methods In this study, donor-matched progenitor cells were isolated via selective fibronectin adhesion from the avascular (PAvas) and vascular (PVas) regions of the meniscus and chondroprogenitors (PChs) from articular cartilage (n=5 donors). In addition, whole mixed populations of cells (MAvas, MVas, MChs) from the same regions were obtained by standard isolation techniques for comparison. The colony formation efficacy of PAvas, PVas and PChs was monitored using Cell-IQ® live cell imaging. Proliferation rates of progenitors were compared with their mixed population counterparts. Cell surface markers indicative of mesenchymal stromal cells (MSCs) profile and progenitor markers were characterised by flow cytometry in all populations. The chondrogenic capacity was assessed via pellet culture assays and measuring chondrogenic gene expression levels, GAG/DNA content and morphology. Results All meniscal progenitor and chondroprogenitor populations showed colony forming capacity in monolayer culture, whereas mixed populations were distributed randomly at passage 0. PVas had significantly lower population doubling times compare to MVas and proliferated faster than PAvas and PChs based on colony forming efficacy. Progenitor populations showed significantly higher positivity for CD49b and CD49c compared to their mixed population counterparts and PChs had a higher positivity level of CD166 compared to mixed chondrocytes. Collagen types II and X expression was significantly downregulated in pellets formed by progenitor populations. GAG/DNA analysis demonstrated that progenitor cells generally produced more GAG than mixed populations. Conclusions Our study demonstrates that the human meniscus contains meniscal progenitor populations in both the avascular and vascular regions. Meniscal progenitors derived from the vascular region exhibit enhanced proliferative and chondrogenic characteristics compared to those from the avascular region; this may associate with the enhanced meniscal healing potential in the vascular region. These findings build on the body of evidence which suggests that meniscal progenitors represent an attractive cell therapy strategy for meniscal regeneration.

MACROSCOPIC AND MICROSCOPIC CHARACTERIZATION OF RAW HERBAL DRUG MAMAJJAKA [ENICOSTEMA AXILLARE SUBSP. LITTORALE (BLUME) A. RAYNAL]

Enicostema axillare subsp. littorale (Blume) A. Raynal belonging to the family Gentianaceae, known as Mamajjaka in Ayurveda, is a medicinally important plant used to treat Madhumeha or diabetes mellitus. The plant has high demand in the Indian herbal drug market and is used in various herbal preparations. The present study was conducted to characterize dried herbal samples of E. axillare subsp. littorale botanically. The botanical characterization involved macroscopic and microscopic studies on the herbal samples. Qualitative and quantitative microscopic characters were studied, and digital photographs of transverse sections (T.S.) and powder cell structures were taken. In T.S. of the stem, the vascular region characters such as the appearance of xylem tissue, lumen diameter of xylem vessels, and powder characters of aerial parts such as abundance and size of starch grains, prismatic crystals, presence of stomata, and trichomes were studied. The characters identified in the present study can be used to identify the herbal samples of E. axillare subsp. littorale in fresh as well as in dry forms.

Improved lipid target level attainment in patients with peripheral artery disease

Background: Patients with peripheral artery disease (PAD) fall under the category of a very high cardiovascular risk. Although, consequent lipid lowering therapy (LLT) is advised, only sparse data on attained target level in PAD exists. Objectives: We aimed to analyse contemporary guideline recommendations for LLT in symptomatic PAD patients. Methods: monocentric, prospective, observational study involving 200 symptomatic PAD patients. Guideline target level attainment and LLT were analysed between 2017 and 2019. Results: Overall 78.5% of the patients were on statin therapy, mainly of high intensity with atorvastatin in 50% and rosuvastatin in 33% of the cases. Average statin dosage adjusted for simvastatin was 55 mg/d. Low density lipoproteincholesterol (LDL-C) was <1.8 mmol/L in 53% and <1.4 mmol/L in 34% of the cases. Mean LDL-C levels were at 1.85 ± 0.88 mmol/L. We observed no difference in the treatment and the target level attainment of patients with a stable PAD (intermittent claudication) or chronic critical PAD. However, patients with ≥1 vascular region affected (i.e. coronary and/or cerebrovascular) were treated more intensively and had lower LDL-C levels than patients with PAD alone. Conclusion: It appears that there is more awareness and improvement of previously documented undertreatment of LDL-C levels in symptomatic PAD patients. Although statin treatment is initiated in the majority of patients, our findings call for a continuously intensified LLT in symptomatic PAD patients.

A Novel ASNO Segmentation Technique for Segmenting the JUXTA Vascular Region

In this modern era the clinical laboratory has greater attention to produce an accurate result for every test particularly in the area of lung tumour. The lung tumour is very essential to detect as well as to follow the treatment of many diseases like benign, malignant etc. This paper is focusing on the segmentation part to find the juxta vascular region. For finding the juxta vascular region in lung three stages are used. First stage is the image acquisition here input lung image is read and then resized. Second stage is the image pre-processing here improved linear iterative clustering technique is used .Third stage is the segmentation here the adjustable surface normal overlap is used. While using the above stages the output for juxta vascular region in the segmentation part is segmented clearly.The juxta vascular region is not clearly found in the previous paper. The research gap for this paper is to find the juxta vascular region in the lung. This juxta vascular region is present in the right side of the lung. Using the Adjustable Surface Normal Overlap (ASNO) segmentation the juxta vascular region is segmented clearly.

121 THREE-DIMENSIONAL ASSESSMENT OF EARLY CORPUS LUTEUM VASCULARITY IN BUFFALO (BUBALUS BUBALIS)

The aim of the study was to develop an objective method to assess the vascular flow to the early corpus luteum (CL) in buffaloes using colour Doppler ultrasound data. Our hypothesis was that 3-dimensional (3D) volumetric analysis of vascularity would demonstrate lower variability between animals compared with conventional 2-dimensional (2D) analysis of single images. Wave emergence and ovulation was synchronized in buffalo (n = 16) using prostaglandin-GnRH based protocols. Colour Doppler ultrasonography (MyLab5, 7.5-MHz linear array, colour gain 65%) was performed daily from Day −2 to 4 (Day 0 = ovulation). Video clips of the ovaries (20 s at 18–28 frames per second, AVI) were recorded by slow and uniform free-hand movement of the transducer. Day 4 CL was used for analysis of vascular area and volume. For 2D vascularity assessment, 3 images (800 × 652 pixels, RGB, BMP) of each CL (at maximum apparent vascularity) were acquired through the clip image function on the ultrasound machine and analysed by ImageJ (Fiji) software (NIH, Bethesda, MD, USA). For 3D vascularity assessment, a portion of the video clip encompassing an entire ovary was identified and exported as a series of 2D TIFF images using Videomach software. The ultrasound scale bar was used to calculate the number of pixels per millimetre and to calibrate the X (horizontal) and Y (vertical) dimensions. For 2D analyses, the CL boundary was drawn using the free-hand manual selection tool in Fiji, the area of the CL (mm2) was recorded, and the border was then enlarged by 1.5 mm to include the peripheral vascular region of the CL. The colour threshold was adjusted to select the vascular region. The 2D vascularity score was calculated as the ratio of the coloured area to the enlarged luteal area. For 3D volumetric analyses, each series of TIFF images was imported as an image sequence in Fiji and colour thresholding (similar to 2D analysis) was applied to save a second TIFF series containing luteal vascular regions (coloured areas) only. The remaining volumetric analyses were completed in Imaris software using the ovarian volume (original TIFF series) and luteal vascular volume (second TIFF series) as separate channels. The Z-dimension thickness of each image was estimated by using the dimensions of a follicle within the same ovary (Z-axis diameter = mean diameter along X- and Y-axes). Similar to 2D analyses, the volume of the CL was obtained by drawing a border along the edge of the CL, the CL border was enlarged by 1.5 mm, and a 3D vascularity score was obtained by building a surface on the luteal vascular image and calculating the vascular to luteal volume ratio. The 2D vascularity score differed from 3D vascularity score (0.21 ± 0.02 v. 0.13 ± 0.02, paired t-test P < 0.01); however, variance did not differ (Bartlett’s test P = 0.32). Our initial results support the notion that the described technique of quantifying vascular volume of the corpus luteum may decrease the technical variability during image assessment and therefore better reflect the true vascularity compared with 2D image analyses. Research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada.

Regional differences in statistical geometry of endothelial dense granules in human extremity veins

Objectives Leg and arm human veins are exposed to different gravitational stresses. We investigated if there is difference in the amount and geometry of secretory vesicles in their endothelium. Methods Superficial small vein segments were removed during vascular operations for electromicroscopic analysis. Vesicular area/total endothelial cross-sectional area was determined by computer-based morphometry. Long and short axes of granule cross sections were measured by image analyzing software. Results Vesicular density in all samples was 2.26 ± 0.34%. There was no significant difference between the vesicular densities of upper extremity and leg. The shape of the vesicles was more frequently elongated in leg than in arm sections ( p < 0.01). Conclusions The density of the vesicles does not depend on vascular region or orthostatic load. Ellipticity of these granules is significantly different in areas exposed to different gravitational stresses. This might contribute to the differences of thrombotic and hemodynamic properties of leg and upper body veins.