Study on the Psychological States of Olfactory Stimuli Using Electroencephalography and Heart Rate Variability.

In the modern information society, people are constantly exposed to stress due to complex work environments and various interpersonal relationships. Aromatherapy is attracting attention as one of the methods for relieving stress using aroma. A method to quantitatively evaluate such an effect is necessary to clarify the effect of aroma on the human psychological state. In this study, we propose a method of using two biological indexes, electroencephalogram (EEG) and heart rate variability (HRV), to evaluate human psychological states during the inhalation of aroma. The purpose is to investigate the relationship between biological indexes and the psychological effect of aromas. First, we conducted an aroma presentation experiment using seven different olfactory stimuli while collecting data from EEG and pulse sensors. Next, we extracted the EEG and HRV indexes from the experimental data and analyzed them with respect to the olfactory stimuli. Our study found that olfactory stimuli have a strong effect on psychological states during aroma stimuli and that the human response to olfactory stimuli is immediate but gradually adapts to a more neutral state. The EEG and HRV indexes showed significant differences between aromas and unpleasant odors especially for male participants in their 20-30s, while the delta wave and RMSSD indexes showed potential for generalizing the method to evaluate psychological states influenced by olfactory stimuli across genders and generations. The results suggest the possibility of using EEG and HRV indexes to evaluate psychological states toward olfactory stimuli such as aroma. In addition, we visualized the psychological states affected by the olfactory stimuli on an emotion map, suggesting an appropriate range of EEG frequency bands for evaluating psychological states applied to the olfactory stimuli. The novelty of this research lies in our proposed method to provide a more detailed picture of the psychological responses to olfactory stimuli using the integration of biological indexes and emotion map, which contributes to the areas such as marketing and product design by providing insights into the emotional responses of consumers to different olfactory products.

Primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation in a swine.

Renal mixed tumor characterized by the absence of nephrogenic blastema and the presence of predominant osteoid-producing osteoblast-like cells occurred in the kidney of a 6-month-old, hybrid, female pig. At the post-mortem examination, the tumor was found as a calcified grayish-white mass at the cranial end of the left kidney. Histologically the tumor consisted of 3 growth areas of poorly differentiated spindle cells, osteoid-producing osteoblast-like cells, and luminal epithelial cells. Transition from the spindle cells to the osteoblast-like cells or the luminal epithelial cells was observed. Immunohistochemically, the spindle cells and the osteoblast-like cells were consistently positive for ß-catenin. Although the luminal epithelial cells and adjacent spindle cells were positive for cytokeratin, these 3 types of tumor cells were consistently negative for WT1. The tumor was diagnosed as primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation.

A piezoelectric drop-on-demand generator for accurate samples in capillary electrophoresis.

In this work, we propose a piezoelectric droplet generator for injection of well-defined amounts of sample in capillary electrophoresis. We demonstrate stable, precise and drop-on-demand droplet formation for various solutions, with precise control of waveform driving piezoelectric crystal inside the ink-jet head. By tuning the waveform, we can also manipulate the droplet size and delivery frequency. This injector was used in sampling for capillary electrophoresis. As a state-of-the-art application, the analysis of theobromine, caffeine and theophiline using micellar electrokinetic chromatography was developed. The volume of sample (single droplet) analyzed in this experiment was 179 pL (RSD=1.2%, n=10). The detection limits for caffeine, theobromine, and theophiline are 0.02, 0.08 and 0.06 mM L(-1), respectively. Compared with conventional methods, the combination of picoliter droplet dispenser with capillary electrophoresis allows precise and accurate sampling, as well as for reduced sample consumption, which will prove to be an efficient tool in quantitative separation and analysis.

Accurate and highly reproducible picoliter injection system for capillary electrophoresis.

A novel, highly accurate sample injection system for capillary electrophoresis (CE) was developed based on an inkjet microchip capable of reproducing exact introduction volumes at the picoliter level. The difficulty in analyte discrimination using electrokinetic injection was also overcome using this injection method. The injection system consisted of an XY stage, an inkjet droplet ejection microchip, and a reservoir with a plug-in septum. To evaluate the precision of the system, a mixture of NBD-labeled amino acids consisting of Gly, L-Phe, L-Asp, and L-Ser was separated, and the performance was compared with that of traditional hydrodynamic and electrokinetic injection methods. The results demonstrated that the introduced volume highly relied on the number of droplets with low relative standard derivation (RSD) and good linear correction coefficient in the proposed injection method. In addition, a urine sample was analyzed via CE coupled with the inkjet injection system for the detection of the amino acid taurine. The concentration of urinary taurine was determined to be 2.42 ± 0.08 µM (confidence level, 95%; RSD, 1.05%; n = 4) with a recovery of 98.92-109.54% (n = 3). These results demonstrate the inkjet injection system we developed has the potential to revolutionize capillary electrophoretic separation in practical and commercial applications that require an automated accurate injection system.

Evaluation of cingulate gyrus blood flow in patients with liver cirrhosis.

Although neuropsychological tests are commonly applied to detect minimal hepatic encephalopathy (HE) in patients with liver cirrhosis (LC), they provide no information about the cerebral regions involved. Recently, it has been reported that some populations of alcoholic cirrhotics, with mild HE, have reduced cerebral metabolic rate for glucose in bifrontal cortices and in the anterior cingulate gyrus. We evaluated the degree of reduction in blood flow at the anterior cingulate gyrus and the frontal lobes in cirrhotic patients who underwent single photon emission computed tomography (SPECT). Data were obtained from 47 cirrhotic patients and 47 subjects without LC. Three radiologists unaware of the results of laboratory tests visually evaluated the transaxial, coronal, and sagittal views of SPECT. The area and the degree of blood flow reduction in the anterior cingulate gyrus and frontal lobes were scored. Reduced blood flow in the anterior cingulate gyrus was observed in most LC patients. In patients without overt HE, poor performance in neuropsychological tests was correlated with reduced cerebral blood flow in the anterior cingulate gyrus. Blood flow in the anterior cingulate gyrus as measured by SPECT may be a simple and good indicator of cerebral functional changes in patients with LC.

Improvement of regional cerebral blood flow after oral intake of branched-chain amino acids in patients with cirrhosis.

AIM: To evaluate the effect of oral intake of branched-chain amino acids (BCAA) on brain perfusion in patients with liver cirrhosis. METHODS: Single photon emission computed tomography scans were performed in 43 patients with cirrhosis and in 15 age-matched healthy subjects. Twenty-nine out of forty-three patients were randomly treated with either BCAA granules or placebo, and single photon emission computed tomography was performed before and after the treatment. We measured the regional cerebral blood flow values using a three-dimensional stereotaxic region of interest template. RESULTS: Cirrhotic patients had regions of significant hypoperfusion in the bilateral central (right P=0.039, P<0.05; left P=0.006 P<0.01), parietal (right P=0.018, P<0.05; left P=0.009, P<0.01), angular (right P=0.039, P<0.05; left P 0.008, P<0.01), and left pericallosal segments (P=0.038 P<0.05) as compared with healthy subjects. A significant increase in cerebral perfusion was observed 70 min after the oral intake of BCAA in the angular (right P=0.012, P<0.05; left P=0.049, P<0.05), temporal (right P=0.012, P<0.05; left P=0.038, P<0.05), pericallosal segments (right P=0.025, P<0.05; left P=0.049, P<0.05) and left precentral (P=0.044, P<0.05), parietal (P=0.040, P<0.05) and thalamus (P=0.033, P<0.05). No significant change in perfusion was observed in the placebo group. CONCLUSION: Administration of BCAA rapidly improves cerebral perfusion.

Single photon emission computed tomography and statistical parametric mapping analysis in cirrhotic patients with and without minimal hepatic encephalopathy.

OBJECTIVE: The early diagnosis and treatment of cognitive impairment in cirrhotic patients is needed to improve the patients' daily living. In this study, alterations of regional cerebral blood flow (rCBF) were evaluated in cirrhotic patients using statistical parametric mapping (SPM). The relationships between rCBF and neuropsychological test, severity of disease and biochemical data were also assessed. METHODS: 99mTc-ethyl cysteinate dimer single photon emission computed tomography was performed in 20 patients with non-alcoholic liver cirrhosis without overt hepatic encephalopathy (HE) and in 20 age-matched healthy subjects. Neuropsychological tests were performed in 16 patients; of these 7 had minimal HE. Regional CBF images were also analyzed in these groups using SPM. RESULTS: On SPM analysis, cirrhotic patients showed regions of significant hypoperfusion in the superior and middle frontal gyri, and inferior parietal lobules compared with the control group. These areas included parts of the premotor and parietal associated areas of the cortex. Among the cirrhotic patients, those with minimal HE had regions of significant hypoperfusion in the cingulate gyri bilaterally as compared with those without minimal HE. CONCLUSIONS: Abnormal function in the above regions may account for the relatively selective neuropsychological deficits in the cognitive status of patients with cirrhosis. These findings may be important in the identification and management of cirrhotic patients with minimal HE.