BACKGROUND: Oculocutaneous albinism (OCA) is a genetic disorder of the melanin pigment system in which melanin synthesis is reduced or absent in the skin, hair, and eyes. OCA is classified into two major types, and tyrosinase-related OCA can be produced by mutations of the structural gene for tyrosinase enzyme (TYR gene). OBJECTIVE: The purpose of this study was to analyze the segregation of mutant alleles of the TYR gene in tyrosinase-negative and tyrosinase-positive Korean OCA patients and families. METHODS: We amplified exon I, II, and III of the TYR gene of Korean OCA patients and their families by polymerase chain reactions (PCR), and analyzed the mutations by restriction fragment length polymorphism (RFLP) analysis in exon I and single-strand conformation polymorphism (SSCP) analyses in exon II and exon III. RESULTS: Two tyrosinase-negative cases showed mutations in exon I. Four tyrosinase-nega-tive cases and one tyrosinase-positive case showed mutations in exon II, and one tyrosinase-neg- ative case showed mutations in exon III. In summary, we found three kinds of mutation in four tyrosinase-negative OCA patients and one tyrsinase-positive OCA patient. CONCLUSIONS: RFLP and SSCP analysis can provide a basis for a rapid and sensitive screening system to detect TYR gene mutations of Korean OCA patients and their families.
Albinism, Oculocutaneous* ; Alleles ; Exons ; Hair ; Humans ; Korea* ; Mass Screening ; Melanins ; Monophenol Monooxygenase ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single-Stranded Conformational ; Skin

PURPOSE: The purpose of this study is to measure the range of normal eye movement and to evaluate the effect of age on the range of ocular movement in a normal population. METHODS: We conducted a prospective observational study of 85 subjects aged between 5 and 91 years. Photographs were taken of the cardinal position, and these images were analyzed using an image analysis software (Adobe Photoshop 6.0, Adobe, San Jose, CA, USA). To measure the range of eye movement, the preprocessed images were analyzed using the Image J program. The range of movement of the eyeball was quantitatively measured using corneal limbal analysis. Specifically, the ranges of ocular movement according to adduction, abduction, elevation, and depression were measured. RESULTS: The normal movement ranges were 44.4 ± 6.9° in adduction, 44.8 ± 5.5° in abduction, 27.7 ± 7.6° in elevation, and 46.7 ± 8.4° in depression. Adduction, abduction, and elevation were negatively correlated with age (R² = 0.220, R² = 0.126, and R² = 0.304, respectively, all p < 0.001). However, there was no significant correlation between age and depression (R² = 0.030, p = 0.113). CONCLUSIONS: For all ages, the range of normal ocular movement in the horizontal direction was symmetric, while the range of ocular movement in elevation was smaller than that of depression. As age increased, the range of ocular movement decreased in all directions except depression, but depression did not decrease with age. When assessing eye movement, it is necessary to consider the range of ocular movements relative to both the movement direction and changes in the ocular movement range according to age.
Aging ; Depression ; Eye Movements* ; Observational Study ; Prospective Studies

Differentiating early Alzheimer's disease (AD) from depression with cognitive impairment is challenging in the elderly. To develop a model for differentiating these two conditions using electroencephalography (EEG), we enrolled 11 patients with early probable AD and 11 age- and cognitive function-matched patients with major depressive disorder (MDD) and compared the EEG relative powers of 9 scalp regions. Compared to the MDD group, the AD group had a higher global theta relative power (p=0.021). In the MDD group, beta relative power was higher in the mid-central region than in the left or right central regions (p<0.01). The prediction model that included global theta relative power and regional beta index was able to discriminate AD from MDD (AUC=0.893, p=0.002). A combination of global theta relative power and intra-individual regional differences in beta may differentiate early AD from MDD with cognitive impairment.
Aged ; Alzheimer Disease* ; Cognition Disorders ; Depression* ; Depressive Disorder, Major ; Diagnosis, Differential ; Electroencephalography* ; Humans ; Scalp

PURPOSE: To identify risk factors that affect the development of type 2 retinopathy of prematurity (ROP) and progression to type 1 or threshold ROP requiring treatment. METHODS: The medical records of premature infants born with a birth weight ≤1,500 g or a gestational age ≤32 weeks were retrospectively reviewed. Potential risk factors were divided into systemic and ophthalmic factors and analyzed by univariate and multivariate logistic regression analyses. RESULTS: Three hundred and twenty-four eyes met the screening criteria. Among them, 41 eyes (12.65%) progressed to type 2 ROP and 21 eyes (6.48%) received treatment after progression to type 1 or threshold ROP. The systemic risk factor associated with progression from type 2 ROP was periventricular leukomalacia and the ophthalmic factor was the existence of nasal ROP at the time of diagnosis of type 2 ROP. CONCLUSIONS: Careful examination was needed when type 2 ROP with periventricular leukomalacia or nasal ROP developed because there was a high probability of progression and treatment.
Birth Weight ; Diagnosis ; Gestational Age ; Humans ; Infant, Newborn ; Infant, Premature ; Leukomalacia, Periventricular ; Logistic Models ; Mass Screening ; Medical Records ; Retinopathy of Prematurity ; Retrospective Studies ; Risk Factors

Through a systematic review and meta-analysis of epidemiological studies on dementia, we assessed the prevalence of dementia and its subtypes-Alzheimer' disease (AD) and vascular dementia (VaD)-in Korea. We searched for epidemiological studies on dementia published in 1990-2013 using PubMed, Scopus, EMBASE, KoreaMed, KISS, and RiCH. Dementia prevalence in elderly patients (aged> or =65 yr) was 9.2% (95% confidence interval [CI], 8.2%-10.4%) from 11 studies, which was higher than those from Western and other Asian countries. AD was the most prevalent dementia type, with a prevalence of 5.7% (95% CI, 5.0%-6.4%) from 10 studies compared with 2.1% (95% CI, 1.6%-2.7%) for VaD from 9 studies. The age-specific prevalence of dementia approximately doubled with each 5.8-yr increase of age. Although a significant increasing trend of dementia prevalence was not observed, it increased slightly from 7.3% to 8.7% after 2005; AD prevalence increased after 1995 and VaD prevalence decreased after the early 2000s. The AD/VaD ratio increased from 1.96 in the early 1990s to 4.13 in the 2010s, similar to the worldwide ratio. Owing to this high prevalence in the aging population, dementia will impose significant economic burdens to Korean society.
Age Factors ; Alzheimer Disease/epidemiology ; Asian Continental Ancestry Group ; Databases, Factual ; Dementia/*epidemiology ; Dementia, Vascular/epidemiology ; Humans ; Prevalence ; Quality Assurance, Health Care ; Republic of Korea

Objective: Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. Methods: Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the β coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. Results: We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). Conclusion The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

Objective: Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. Methods: Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the β coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. Results: We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). Conclusion The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

Objective: Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. Methods: Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the β coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. Results: We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). Conclusion The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

Objective: Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. Methods: Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the β coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. Results: We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). Conclusion The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

Metastatic cancer to the esophagus is rare and the breasts are the most common primary tumors that metastasize to the esophagus. Since metastatic breast cancer is located in the submucosal layer, diagnosis by general forceps biopsy is difficult. Hence, various techniques including endoscopic ultrasound guided fine needle aspiration, endoscopic ultrasound guided fine needle biopsy, unroofing technique, and submucosal tunneling method are used for diagnosis. Moreover, the patient's medical history should be inspected carefully and previous histological findings of cancer should also be evaluated. Herein, the authors report a case of metastatic breast cancer along with literature reviews. Endoscopy was performed in patient who had undergone breast cancer surgery 13 years previously. Histological examination from a midesophageal stricture was normal. Endoscopic ultrasound was performed and uneven hypoechoic masses were found in the third layer of the esophageal wall. The esophageal stricture was finally diagnosed as metastatic breast cancer by endoscopic ultrasound-guided fine needle biopsy.
Biopsy ; Biopsy, Fine-Needle* ; Breast ; Breast Neoplasms* ; Constriction, Pathologic ; Diagnosis ; Endoscopic Ultrasound-Guided Fine Needle Aspiration ; Endoscopy ; Endosonography ; Esophageal Stenosis* ; Esophagus ; Humans ; Neoplasm Metastasis ; Surgical Instruments ; Ultrasonography*