Yoonju Lee

Supply chain model for the semiconductor industry in consideration of manufacturing characteristics

The semiconductor industry has a supply chain network that is distributed all over the world, and its manufacturing process has the particular characteristics that should be considered in supply chain modelling. In this paper we suggest an integrated mathematical model for the semiconductor industry supply chain consisting of production and distribution chains, where manufacturing re-entrancy, binning and substitution are considered. To achieve our objective, three policies for the production chain and two policies for the distribution chain with mathematical formulations are suggested. Six combination policies are tested for the evaluation of performances with an example motivated by a major semiconductor manufacturer in Eechon, South Korea. It is shown that the balance policy for the production chain and the pull policy for the distribution outperform other policies.

Predictive characteristics of patients achieving glycaemic control with insulin after sulfonylurea failure

Aim:  We investigated the clinical and metabolic parameters in type 2 diabetic patients who were inadequately controlled on sulfonylurea (SU) before initiating insulin therapy to characterise patients who are likely to achieve target glycaemic control with insulin analogues.

Subcortical shape analysis of progressive mild cognitive impairment in Parkinson's disease

Cortical neural correlates of ongoing cognitive decline in Parkinsons disease (PD) have been suggested; however, the role of subcortical structures in longitudinal change of cognitive dysfunction in PD has not been fully investigated. Here, we used automatic analysis to explore subcortical brain structures in patients with PD with mild cognitive impairment that converts into PD with dementia.

Recurrent Cardioembolic Stroke Treated Successfully with Repeated Mechanical Thrombectomy within the Acute Index Stroke Period

Background The safety of repeated mechanical thrombectomy within the acute stroke period has not yet been clearly demonstrated. We describe herein a patient who was successfully treated with repeated mechanical thrombectomy within the acute index stroke period. Case Report A 50-year-old woman with atrial fibrillation presented with left-sided weakness caused by occlusion of the right middle cerebral artery (MCA). Emergent mechanical thrombectomy with the Solitaire device achieved complete recanalization. The left MCA occlusion redeveloped at 6 days after the first treatment, at which time her international normalized ratio (INR) was 2.3. Endovascular thrombectomy was reattempted rapidly and complete recanalization was achieved again. Her neurologic symptoms resolved after the thrombectomy. Conclusions This case demonstrates that repeated mechanical thrombectomy can be safely and successfully performed even in a patient with a high INR and a recurrent stroke during the acute period after the index stroke.

Effects of lobeglitazone, a novel thiazolidinedione, on adipose tissue remodeling and brown and beige adipose tissue development in db/db mice

Background/Objectives:We investigated the effect of long-term treatment with lobeglitazone, a novel thiazolidinedione-based activator of peroxisome proliferator-activated receptor gamma, on adipose tissue (AT), focusing on its effects on insulin resistance in obese db/db mice.Methods:Seven-week-old male db/db mice were assigned to either a vehicle-treated (n=8) or lobeglitazone-treated (n=8) group. Lobeglitazone (1 mg kg−1 daily) was injected intraperitoneally for 20 weeks.Results:Lobeglitazone treatment for 20 weeks resulted in a remarkably improved glycemic index, including significantly decreased glucose levels, enhanced insulin sensitivity and preserved pancreatic beta cells. Both whole body and subcutaneous AT weight increased in the lobeglitazone-treated group. However, lobeglitazone induced an increase in the number of small adipocyte in both epididymal and subcutaneous AT, with a significant weight decrease in the epididymal AT of db/db mice. Using flow cytometry, the CD11c-positive M1 macrophages and CD206-positive M2 macrophages in the epididymal AT were observed to exhibit a decreased M1-to-M2 ratio in lobeglitazone-treated db/db mice. Furthermore, in the lobeglitazone-treated group, interscapular brown AT was clearly visualized by 18F-fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography (18F-FDG-PET/CT) and its mass was significantly greater than that of the vehicle-treated group. In the lobeglitazone-treated group, beige-specific gene expression and the number of mitochondria in white AT were upregulated. Lobeglitazone, with upregulating interferon regulatory factor-4 (a key transcriptional regulator of thermogenesis), promoted the development of brown adipocytes and the differentiation of white adipocytes into beige adipocytes.Conclusions:Long-term lobeglitazone treatment has a beneficial role in remodeling and ameliorating inflammation in white AT and in glycemic control, in relation to insulin sensitivity in obese db/db mice. Moreover, lobeglitazone induced the differentiation of brown and beige adipocytes. Collectively, our data suggest that lobeglitazone treatment provides promising effects on white and brown AT as well as great improvement in glycemic control, as a potent insulin sensitizer.

Familiar Hyperekplexia, a Potential Cause of Cautious Gait: A New Korean Case anda Systematic Review of Phenotypes

Familial hyperekplexia, also called startle disease, is a rare neurological disorder characterized by excessive startle responses to noise or touch. It can be associated with serious injury from frequent falls, apnea spells, and aspiration pneumonia. Familial hyperekplexia has a heterogeneous genetic background with several identified causative genes; it demonstrates both dominant and recessive inheritance in the α1 subunit of the glycine receptor (GLRA1), the β subunit of the glycine receptor and the presynaptic sodium and chloride-dependent glycine transporter 2 genes. Clonazepam is an effective medical treatment for hyperekplexia. Here, we report genetically confirmed familial hyperekplexia patients presenting early adult cautious gait. Additionally, we review clinical features, mode of inheritance, ethnicity and the types and locations of mutations of previously reported hyperekplexia cases with a GLRA1 gene mutation.

Does Smoking Impact Dopamine Neuronal Loss in de novo Parkinson's Disease?

This study analyzed data from dopamine transporter (DAT) positron emission tomographic scans of 282 male patients with de novo Parkinson disease to investigate whether smoking impacts striatal dopamine neuronal degeneration. Mean DAT activity in the posterior (p = 0.016) and ventral putamen (p = 0.028) was higher in 44 current smokers in comparison to 105 ex‐smokers and 133 never‐smokers. The severity of baseline motor deficits and the longitudinal increases in levodopa‐equivalent doses during follow‐up were similar among the 3 groups. These results suggest that current smoking, but not past smoking, protects dopamine neuronal degeneration in the sensorimotor striatum with no additional clinical benefits. Ann Neurol 2017;82:850–854

Precise Muscle Selection Using Dynamic Polyelectromyography for Treatment of Post-stroke Dystonia: A Case Report

Dystonia has a wide range of causes, but treatment of dystonia is limited to minimizing the symptoms as there is yet no successful treatment for its cause. One of the optimal treatment methods for dystonia is chemodenervation using botulinum toxin type A (BTX-A), alcohol injection, etc., but its success depends on how precisely the dystonic muscle is selected. Here, we reported a successful experience in a 49-year-old post-stroke female patient who showed paroxysmal repetitive contractions involving the right leg, which may be of dystonic nature. BTX-A and alcohol were injected into the muscles which were identified by dynamic polyelectromyography. After injection, the dystonic muscle spasm, cramping pain, and the range of motion of the affected lower limb improved markedly, and she was able to walk independently indoors. In such a case, dynamic polyelectromyography may be a useful method for selecting the dominant dystonic muscles.

Subjective Cognitive Complaints and Objective Cognitive Impairment in Parkinson's Disease

Background and Purpose Subjective cognitive complaints (SCCs) are very common in patients with Parkinsons disease (PD). However, the relationship between SCCs and objective cognitive impairment is still unclear. This study aimed to determine whether SCCs are correlated with objective cognitive performance in patients with PD. Methods Totals of 148 cognitively normal patients, 71 patients with mild cognitive impairment (MCI), and 31 demented patients were recruited consecutively from a movement-disorders clinic. Their SCCs and cognitive performances were evaluated using the Cognitive Complaints Interview (CCI) and a comprehensive neuropsychological battery. Results The CCI score increased with age, duration of PD, and depression score, and was inversely correlated with cognitive performance. The association between CCI score and performance remained significant after adjustment for the depression score, age, and duration of PD. The CCI score could be used to discriminate patients with dementia from cognitively normal and MCI patients [area under the receiver operating characteristics curve (AUC) of 0.80], but not patients with MCI or dementia from cognitively normal patients (AUC of 0.67). Conclusions SCCs as measured by the CCI are strongly correlated with objective cognitive performance in patients with PD. The CCI can also be used to screen for dementia in patients with PD.

Effects of dopaminergic depletion and brain atrophy on neuropsychiatric symptoms in de novo Parkinson’s disease

Background Neuropsychiatric symptoms impact the patients’ quality of life and caregivers’ burdens in Parkinson’s disease (PD). We aimed to investigate the effects of striatal dopaminergic depletion and brain atrophy on the neuropsychiatric symptoms of patients with PD. Methods Two hundred and seven patients with de novo drug-naïve PD underwent dopamine transporter (DAT) positron emission tomography and brain MRI scanning. In addition, the patients were assessed with caregiver-administered neuropsychiatric inventory (NPI) questionnaires. To evaluate the effects of DAT uptake, subcortical volume and cortical thinning on the patients’ neuropsychiatric symptoms, we performed logistic regression and negative binomial regression analyses on the NPI data after controlling for possible confounders. Results Frontal cortical thinning was associated with the presence of nighttime behaviour and irritability, and the thinning correlated with the severity of the nighttime behaviour. Temporal cortical thinning was associated with the presence of aggression/agitation, and it correlated with the severity of the aggression/agitation. Subcortical atrophy in the accumbens was associated with the presence of disinhibition and correlated with the severity of the disinhibition. Putamen atrophy and insular thinning were independently associated with the presence of apathy, but only insular thinning correlated with the severity of the apathy. Of the predictors, only frontal cortical thinning correlated with the total NPI score. Conclusions The results of this study suggested that accumbens atrophy and frontotemporal cortical thinning, especially frontal cortical thinning, independently contributed to neuropsychiatric symptoms in patients with PD, while DAT uptake did not affect the neuropsychiatric symptoms.