Simultaneous visualization of multiple neuronal properties with single-cell resolution in the living rodent brain

To understand the fine-scale structures and functional properties of individual neurons in vivo, we developed and validated a rapid genetic technique that enables simultaneous investigation of multiple neuronal properties with single-cell resolution in the living rodent brain. Our technique PASME (promoter-assisted sparse-neuron multiple-gene labeling using in uteroelectroporation) targets specific small subsets of sparse pyramidal neurons in layer 2/3, layer 5 of the cerebral cortex and in the hippocampus with multiple fluorescent reporter proteins such as postsynaptic PSD-95-GFP and GFP-gephyrin. The technique is also applicable for targeting independently individual neurons and their presynaptic inputs derived from surrounding neurons. Targeting sparse layer 2/3 neurons, we uncovered a novel subpopulation of layer 2/3 neurons in the mouse cerebral cortex. This technique, broadly applicable for probing and manipulating neurons with single-cell resolution in vivo, should provide a robust means to uncover the basic mechanisms employed by the brain, especially when combined with in vivo two-photon laser-scanning microscopy and/or optogenetic technologies.     

Anatomical details of the brainstem and cranial nerves visualized by high resolution readout-segmented multi-shot echo-planar diffusion-weighted images using unidirectional MPG at 3T

We compared diffusion-weighted imaging (DWI) with readout-segmented multi-shot echo-planar imaging (rs-EPI) and single-shot EPI, both using unidirectional motion-probing gradient, in 10 patients for visualization of the anatomical structures in the brainstem. DWI by rs-EPI was significantly better than DWI by single-shot EPI for visualizing the medial longitudinal fasciculus, lateral lemniscus, corticospinal tract, and seventh/eighth cranial nerves and offered significantly less distortion of the brainstem.     

Plasma substance P level in patients with schizophrenia: a cross-sectional study

Aspiration pneumonia is a serious health concern in older patients with schizophrenia. In this study, we examined clinical and demographic variables that could impact the plasma substance P level, which is a useful predictive biomarker of aspiration. Thirty-four patients were included (mean age ± SD: 70.9 ± 10.8 years). A greater number of cigarettes/day and a higher antipsychotic dosage were found to be associated with a lower plasma substance P level, while age showed a trend-level effect. This finding suggests the need for intensive observation for prevention of aspiration pneumonia in heavy smokers who are receiving a higher antipsychotic dose in this senior population.     

Vascular risk factors are associated with faster decline of Alzheimer disease: a longitudinal SPECT study

We investigated the effects of cardiovascular risk factors, such as hypertension, diabetes mellitus, and hypercholesterolemia, on longitudinal regional cerebral blood flow (rCBF) changes in Alzheimer’s disease (AD). We followed 68 outpatients with probable AD for an average of 40 months. They were divided into three groups based on no (n = 24), single (n = 27), and multiple (n = 17) vascular risk factors. We assessed longitudinal changes on the Mini-Mental State Examination, Functional Assessment Staging scores, and in rCBF deficits using repeated single photon emission computed tomography (SPECT) using N-isopropyl-p-[¹²³I] iodoamphetamine. During follow-up, the multiple vascular risk factor group showed faster cognitive and functional decline than the no and single vascular risk factor groups. When compared with the initial SPECT, the follow-up SPECT showed a significant rCBF reduction in widespread regions, including the parietotemporal, frontal, and limbic lobes, in the multiple and single vascular risk factor groups, while there was rCBF reduction in small scattered regions of the temporoparietal lobe in the no vascular risk factor group. Multiple vascular risk factors are associated with a greater rate of decline in cognition, function, and rCBF in patients with AD. Our results highlight the contribution of vascular risk factors on the progression of AD.     

Aortic and hepatic enhancement at multidetector CT: evaluation of optimal iodine dose determined by lean body weight

Purpose

To determine the optimal iodine dose for aortic and hepatic enhancement at MDCT by comparing lean body weight (LBW) with total body weight (TBW).

Materials and methods

This study was approved by our institutional review committee. One hundred and thirty-six patients were randomized into four groups: 550, 650, 750 mg iodine/(kg of LBW) and 600 mgI/(kg of TBW). The aortic and hepatic contrast enhancements (ΔHUs) during the portal venous-phase and variances of ΔHUs were compared.

Results

Mean ΔHUs for 550, 650, 750 mgI/kg LBW and 600 mgI/kg TBW were: 95.1, 109.9, 122.4, and 131.2 HU, respectively, for the aorta. For the liver, 43.1, 55.4, 60.8, and 63.5 HU. Mean ΔHUs increased with iodine dose per kg LBW (p < 0.01), but no significant difference between 750 mgI/kg LBW and 600 mgI/kg TBW groups. Hepatic enhancement increased by ≥50 HU in 94% of patients with 750 mg/kg LBW. Variance of hepatic enhancement was marginally greater in the 600 mgI/kg TBW than in the 550 and 750 mgI/kg LBW.

Conclusion

Hepatic enhancement variation was reduced with iodine doses based on LBW. Iodine dose of 750 mg iodine/kg LBW was appropriate to achieve hepatic enhancement ≥50 HU in 94% of patients.     

Anesthetic management for a patient with scoliosis combined with central core disease

We gave general anesthesia to a patient with scoliosis combined with central core disease (CCD). CCD is a slowly progressive autosomal dominant congenital myopathy. CCD is presented typically in infancy with hypotonia and delay of motor development, characterized by predominantly proximal weakness pronounced in the hip girdle. Orthopedic complications are common with congenital dislocation of the hips, scoliosis and foot deformity. CCD is due to mutations in the skeletal muscle ryanodine receptor (RYR1) gene at chromosome 19q13.1, which is also implicated in the malignant hyperthermia (MH). A patient with CCD is at risk of MH, with an abnormal response to suxamethonium and volatile anesthetics. The anesthetist ought to be aware of the diagnosis of CCD and to plan anesthetic management accordingly, avoiding potentially MH-triggering agents. We used total intravenous anesthesia (TIVA) in this case, and he showed no MH symptoms perioperatively. This report demonstrates that anesthesia in a patient with CCD could be successfully maintained with TIVA.