Suji Lee

Utilization of algal sugars and glycerol for enhanced cephalosporin C production by Acremonium chrysogenum M35

In our previous study, glycerol was utilized as an additional carbon source for the production of cephalosporin C (CPC) by Acremonium chrysogenum M35. In this study, algal sugars extracted from the third‐generation biomass were utilized in the CPC production for the first time. The CPC production improved about twofold when using the algal sugars as the carbon source. The complex medium including algal sugars and glycerol was utilized, and 7·3 g l−1 CPC production was achieved in a 250‐ml shaking flask. To determine the important variables for the CPC production, Plackett–Burman design was carried out and 6·18 g l−1 of CPC was estimated under the numerically optimized conditions. Under the optimized conditions, the CPC production was performed in a 5‐l scale bioreactor, affording CPC production at a rate of 7·1 g l−1. Moreover, 6·7 g l−1 CPC was produced using crude glycerol as the substrate.

Dehydroepiandrosterone sulfate level varies nonlinearly with symptom severity in major depressive disorder

Objective The pathophysiology of major depressive disorder (MDD) is still not well understood. Conflicting results for surrogate biomarkers in MDD have been reported, which might be a consequence of the heterogeneity of MDD patients. Therefore, we aim to investigate how the severity of depression and various symptom domains are related to the levels of dehydroepiandrosterone sulfate (DHEA-s) in MDD patients. Methods We recruited 117 subjects from a general practice. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). Depressive symptoms were divided into three subdomains according to BDI items; somatic symptoms, guilt and failure, and mood and inhibition. Results In subjects with very-mild-to-moderate depression, the DHEA-s level increased as BDI score did. However, the DHEA-s levels in the subjects with severe depression were significantly lower than in subjects with moderate depression (p=0.003). DHEA-s level was correlated with the BDI subscore for guilt and failure in very-mild-to-moderate depression (r=0.365, p=0.006). Conclusion The DHEA-s level appears to be indicative of MDD severity with respect to depressive symptoms, especially regarding guilt and failure. Our findings suggest that the upregulation of DHEA-s may be a part of a compensatory process in very-mild-to-moderate depression, and the failure of this compensation mechanism may underlie the development of severe depression.

Predicting neurocognitive function with hippocampal volumes and DTI metrics in patients with Alzheimer's dementia and mild cognitive impairment

Cognitive performance in patients with Alzheimers dementia (AD) and mild cognitive impairment (MCI) has been reported to be related to hippocampal atrophy and microstructural changes in white matter (WM). We aimed to predict the neurocognitive functions of patients with MCI or AD using hippocampal volumes and diffusion tensor imaging (DTI) metrics via partial least squares regression (PLSR).

Regional glucose metabolism due to the presence of cerebral amyloidopathy in older adults with depression and mild cognitive impairment

BACKGROUND Depression is a risk factor for mild cognitive impairment (MCI) and for the conversion from MCI to Alzheimers disease (AD). This study investigated regional cerebral glucose metabolism (rCMglc) in older adults with depression and MCI, either with or without amyloidopathy. METHODS We recruited 31 older adults diagnosed with depression and MCI, and 21 older adults with normal cognition (NC). All participants completed demographic questionnaires and were examined with a standardized neuropsychological battery, F-18 fluorodeoxyglucose positron emission tomography (PET), and F-18 florbetaben PET. We classified subjects with depression and MCI into amyloid-β-positive (CDAP; n = 16) and amyloid-β-negative (CDAN; n = 15) groups. Pairwise rCMglc analyses were conducted between all three groups (CDAP vs. NC, CDAN vs. NC, and CDAP vs. CDAN). RESULTS In comparison with the NC group, the CDAP group showed reduced rCMglc predominantly in temporoparietal regions, whereas the CDAN group showed lower rCMglc in regions of the frontal lobe, in addition to the temporoparietal regions. The CDAN group also showed lower rCMglc in right anterior cingulate and left inferior orbitofrontal regions, in a comparison between the CDAP and CDAN groups. LIMITATIONS The generalizability of the findings is limited because this study has a relatively small number of participants. In addition, this study used cross-sectional design rather than longitudinal design. CONCLUSIONS Our findings may provide a reference to assess the risk of future cognitive deterioration. Consequently, this study is expected to contribute to prevention and early identification of dementia associated with AD.

Effects of Psychotropic Drugs on Seizure Threshold during Electroconvulsive Therapy

Objective To analyze the relationship between seizure threshold (ST) and psychotropic drugs in patients treated with ECT. Methods We examined clinical data from 43 patients. ST was titrated at each treatment session. We examined associations between ST and psychotropic drugs using multivariate correlation analyses. Data are presented as initial ST, the difference in ST between the first and 10th sessions (ΔST10th), and the mean difference in ST between the first and last sessions (mean ΔSTlast). Results Multivariate regression analyses showed associations between initial ST and the total chlorpromazine-equivalent dose of antipsychotics (β=0.363, p<0.05). The total fluoxetine-equivalent dose of antidepressants was associated with ΔST10th (β=0.486, p<0.01) and mean ΔSTlast (β=0.472, p<0.01). Conclusion Our study elucidated possible effects of psychotropic drugs on ST shifts. Larger doses of antipsychotics were associated with higher initial ST, whereas higher doses of antidepressants were associated with stronger shifts in ST.

Obstetric risk factors for depression during the postpartum period in South Korea: a nationwide study

OBJECTIVE Postpartum depression is related to many adverse effects in both mothers and their children; therefore, proper screening and early interventions are needed. This study aims to identify the risk factors of postpartum depression. Our primary focus is on obstetric risk factors. METHODS This study is a cross-sectional study which we extracted the data of women who gave birth between January 1st, 2010 and December 31st, 2012 from the Health Insurance Review and Assessment service (HIRA) database. We analyzed the data using multivariable logistic regression models. RESULTS A total of 17,483 (1.4%) women suffered from depression during the postpartum period. Younger (<20years) and advanced maternal age (≥35years), primiparity, previous depression, peripartum hysterectomy, uterine artery embolization, preterm delivery, placental abruption, cesarean delivery, induced labor, and preeclampsia were found to increase the likelihood of having depression after delivery. CONCLUSIONS Our findings suggest that there are several risk factors that lead women to postpartum depression. Therefore, early detection and well-management of the symptoms and risk factors for postpartum depression along with social support can help both physical and psychological conditions of women after childbirth.

COMPARISON OF GRAY MATTER VOLUME AND FRACTIONAL ANISOTROPY IN MILD COGNITIVE IMPAIRMENT PATIENTS WITH AND WITHOUT AMYLOIDOPATHY

in the columnar cortical diffusionmeasurements were seen between Alzheimer’s and healthy aged participants with a diagnostic group classification accuracy of>95% (combined dataset of 81 subjects). The same measurements successfully categorised MCI participants who progressed to dementia within 2 years of scan, separately from stable MCI (20 subjects). Conclusions: These results indicate that cortical microstructure organisation in dementia is detectable using MRI of living subjects and may provide a marker of Alzheimer’s disease with high classification accuracy. These findings offer the prospect that future studies will be able to investigate the relationship between cognition and altered organisation of cerebral cortex microstructure, in vivo, in order to assess the damage to cellular networks as an index of disease progression. To significantly improve the lives of people with Alzheimer’s disease, an analysis method which improves early detection and differentiation of dementias has the potential to facilitate earlier and more effective care and to improve the success of drug trials.