Anatomical variations of the internal jugular vein in the context of central line placement: A visual approach to data processing

Central line placement in the internal jugular vein (IJV) can result in complications. Previous studies that examined variations in geometric anatomical parameters in pediatric populations have reduced these risks in children. The aim of this study was to establish possible anatomical variations to improve central line placement in the adult population and demonstrate the use of a correlation heatmap in processing large amounts of data. Twenty-seven volunteers were imaged using ultrasound at three different neck levels on right and left sides and various anatomical parameters were measured. Demographic information was also collected and included in the data processing. The Pearson coefficient was derived from each possible relationship between the measured parameters and was plotted in a correlation heatmap. Strong correlations were observed between the body mass index and the depth of the IJV and common carotid artery (CCA), the relative depth of the IJV to the CCA. No significant correlations were found in the dimensions of both vessels. Anatomical variations were more common than anticipated and should be taken into account when performing central line catheterization in order to minimize post-procedure complications.

The early fetal development of human neocortical GABAergic interneurons

GABAergic interneurons are crucial to controlling the excitability and responsiveness of cortical circuitry. Their developmental origin may differ between rodents and human. We have demonstrated the expression of 12 GABAergic interneuron-associated genes in samples from human neocortex by quantitative rtPCR from 8 to 12 postconceptional weeks (PCW) and shown a significant anterior to posterior expression gradient, confirmed by in situ hybridization or immunohistochemistry for GAD1 and 2, DLX1, 2, and 5, ASCL1, OLIG2, and CALB2. Following cortical plate (CP) formation from 8 to 9 PCW, a proportion of cells were strongly stained for all these markers in the CP and presubplate. ASCL1 and DLX2 maintained high expression in the proliferative zones and showed extensive immunofluorescent double-labeling with the cell division marker Ki-67. CALB2-positive cells increased steadily in the SVZ/VZ from 10 PCW but were not double-labeled with Ki-67. Expression of GABAergic genes was generally higher in the dorsal pallium than in the ganglionic eminences, with lower expression in the intervening ventral pallium. It is widely accepted that the cortical proliferative zones may generate CALB2-positive interneurons from mid-gestation; we now show that the anterior neocortical proliferative layers especially may be a rich source of interneurons in the early neocortex.