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Kang WH, Yoon KH, Lee ES, Kim J, Lee KB, Yim H, Sohn S, Im S. Melasma: histopathological characteristics in 56 Korean patients. Br J Dermatol 2002; 146:228-37. [PMID: 11903232 DOI: 10.1046/j.0007-0963.2001.04556.x] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light to dark brown macules and patches on sun-exposed areas of the skin. Its histopathological characteristics are not fully understood. OBJECTIVES To characterize the histopathological features of facial melasma skin in comparison with adjacent normal skin. METHODS Biopsies were taken from both melasma lesional skin and adjacent perilesional normal skin in 56 Korean women with melasma. The sections were stained using haematoxylin and eosin, Fontana-Masson, diastase-resistant periodic acid-Schiff, Masson trichrome and Verhoeff-van Gieson stains, and immunostaining for melanocytes. Data on the changes in number of melanocytes and melanin contents of the epidermis were analysed by a computer-assisted image analysis program. The ultrastructure of the skin was also examined. RESULTS The amount of melanin was significantly increased in all epidermal layers in melasma skin. The staining intensity and number of epidermal melanocytes increased in melasma lesions. Lesional skin showed more prominent solar elastosis compared with normal skin. Melanosomes increased in number and were more widely dispersed in the keratinocytes of the lesional skin. Lesional melanocytes had many more mitochondria, Golgi apparatus, rough endoplasmic reticulum and ribosomes in their cytoplasm. A dihydroxyphenylalanine reaction was apparent in the cisternae and vesicles of the trans-Golgi network in melanocytes from lesional skin. CONCLUSIONS Melasma is characterized by epidermal hyperpigmentation, possibly caused both by an increased number of melanocytes and by an increased activity of melanogenic enzymes overlying dermal changes caused by solar radiation.
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Kim YH, Kim EY, Gwag BJ, Sohn S, Koh JY. Zinc-induced cortical neuronal death with features of apoptosis and necrosis: mediation by free radicals. Neuroscience 1999; 89:175-82. [PMID: 10051227 DOI: 10.1016/s0306-4522(98)00313-3] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Some studies have provided evidence that delayed death of hippocampal CA1 neurons in transient global ischemia occurs by classical apoptosis. Recently, translocation of synaptic zinc has been shown to play a key role in ischemic CA1 neuronal death. With these two lines of evidence, we examined in mouse cortical cultures the possibility that zinc neurotoxicity, slowly triggered over a day, may occur by classical apoptosis. Exposure of cortical cultures to 30-35 microM zinc for 24 h resulted in slowly evolving death of neurons only, while exposure to zinc at higher concentrations ( > or = 40 microM) produced near-complete death of both neurons and glia. DNA agarose gel electrophoresis revealed internucleosomal DNA fragmentation, and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method revealed DNA breaks in degenerating neurons after 24 h exposure to 30-35 microM zinc, suggesting that the death may occur by apoptosis. However, electron-microscopic examinations revealed ultrastructural changes clearly indicative of necrosis, such as marked swelling of intracellular organelles and disruption of cell membranes amid relatively intact nuclear membranes. Furthermore, the slowly triggered zinc neurotoxicity was not attenuated by cycloheximide, neurotrophins (brain-derived neurotrophic factor, neurotrophin-3, neurotrophin-4/5) or high potassium, all of which effectively reduced several forms of apoptosis in our cortical cultures. Interestingly, a vitamin E analogue trolox almost completely blocked slowly triggered zinc neurotoxicity, indicating that free radical injury is the main mechanism of zinc neurotoxicity. Consistently, exposure to zinc increased membrane lipid peroxidation assessed by the thiobarbituric acid reactive substance assay. Although zinc-induced neuronal death, slowly triggered over a day, is associated with DNA fragmentation, overall it exhibited features more typical of necrosis. This neuronal death is probably mediated by free radical injury. Further studies appear warranted to investigate the mechanistic link between toxic zinc influx and free radical generation and the possibility that selective neuronal death in transient global ischemia also occurs by zinc-triggered neuronal death exhibiting features of both apoptosis and necrosis.
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Tamami B, Sohn S, Wilkes GL. Incorporation of carbon dioxide into soybean oil and subsequent preparation and studies of nonisocyanate polyurethane networks. J Appl Polym Sci 2004. [DOI: 10.1002/app.20049] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Kim EY, Koh JY, Kim YH, Sohn S, Joe E, Gwag BJ. Zn2+ entry produces oxidative neuronal necrosis in cortical cell cultures. Eur J Neurosci 1999; 11:327-34. [PMID: 9987035 DOI: 10.1046/j.1460-9568.1999.00437.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Evidence has accumulated that Zn2+ plays a central role in neurodegenerative processes following brain injuries including ischaemia or epilepsy. In the present study, we examined patterns and possible mechanisms of Zn2+ neurotoxicity. Inclusion of 30-300 microM Zn2+ for 30 min caused neuronal necrosis apparent by cell body and mitochondrial swelling in cortical cell cultures. This Zn2+ neurotoxicity was not attenuated by antiapoptosis agents, inhibitors of protein synthesis or caspase. Blockade of glutamate receptors or nitric oxide synthase showed no beneficial effect against Zn2+ neurotoxicity. Interestingly, antioxidants, trolox or SKF38393, attenuated Zn(2+)-induced neuronal necrosis. Pretreatment with insulin or brain-derived neurotrophic factor increased the Zn(2+)-induced free radical injury. Kainate or AMPA facilitated Zn2+ entry and potentiated Zn2+ neurotoxicity in a way sensitive to trolox. Reactive oxygen species and lipid peroxidation were generated in the early phase of Zn2+ neurotoxicity. These findings indicate that entry and accumulation of Zn2+ result in generation of toxic free radicals and then cause necrotic neuronal degeneration under certain pathological conditions in the brain.
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Pai H, Sohn S, Seong Y, Kee S, Chang WH, Choe KW. Central nervous system involvement in patients with scrub typhus. Clin Infect Dis 1997; 24:436-40. [PMID: 9114196 DOI: 10.1093/clinids/24.3.436] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Scrub typhus, which is caused by Orientia tsutsugamushi, is a systemic illness that causes generalized vasculitis. The central nervous system (CNS) is the most crucial target in other rickettsial diseases; however, there have been several reports of encephalitis or meningitis without direct evidence of rickettsial invasion of the CNS in cases of scrub typhus. To investigate CNS involvement in cases of scrub typhus, we analyzed the CSF profiles (cell count and levels of protein and glucose) and amplified rickettsial DNA in CSF specimens by means of nested polymerase chain reaction (PCR) for 25 patients with the infection. Mild pleocytosis was present in 48% of the patients: CSF white blood cell counts ranged from 0 to 110/mm3 (mean [+/- SD] count, 16.3 +/- 27.0/mm3), and the mean (+/- SD) lymphocyte proportion was 51.9% +/- 23.9%. The CSF protein level was increased (>50 mg/dL) in seven patients. Nested PCR amplified six products from the 25 CSF specimens: four of the products were Boryong genotypes, and two were Karp genotypes. The results of this study suggest that O. tsutsugamushi does invade the CSF and that scrub typhus should be considered one of the causes of mononuclear meningitis in areas of endemicity.
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Lee S, Bang D, Cho YH, Lee ES, Sohn S. Polymerase chain reaction reveals herpes simplex virus DNA in saliva of patients with Behçet's disease. Arch Dermatol Res 1996; 288:179-83. [PMID: 8967789 DOI: 10.1007/bf02505221] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The etiology of Behçet's disease is unclear, but viral infection is thought to be one etiologic factor. The aims of this study were to detect herpes simplex virus (HSV) DNA in the saliva of patients with Behçet's disease and of healthy persons, to determine whether the presence of HSV in saliva is associated with the presence of intraoral ulcer, and to investigate the relationship between HSV and Behçet's disease. The polymerase chain reaction (PCR) was used to detect HSV DNA sequences in DNA extracted from the saliva of patients with Behçet's disease and of healthy control subjects. Of 66 patients with Behçet's disease diagnosed clinically, 19 were diagnosed as complete type, 29 as incomplete type and 18 as suspected type. Of 66 DNA preparations from the saliva of the patients, 26 (39.4%) showed the 289-bp band. This contrasts with 12 of 87 preparations (13.8%) from healthy controls (P < 0.01). There were no significant differences among the three patient groups. All the 289-bp bands analyzed by restriction endonuclease digestion yielded the expected 158-bp and 131-bp fragments when digested with PstI.HSV DNA was detected in 12 of 33 Behçet's disease patients (36.4%) with oral ulceration and 14 of 33 patients (42.4%) without oral ulceration at the time of testing. There was no statistically significant correlation in the PCR results between the two groups.
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Sohn S, Schoeffski O, Prinz J, Reich K, Schubert E, Waldorf K, Augustin M. Cost of Moderate to Severe Plaque Psoriasis in Germany: A Multicenter Cost-of-Illness Study. Dermatology 2006; 212:137-44. [PMID: 16484820 DOI: 10.1159/000090654] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 08/19/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND There is little information concerning the costs of psoriasis and patients' quality of life (QoL) in Germany. OBJECTIVE To obtain data on the annual costs and QoL(to follow in a further publication) of patients with moderate to severe plaque psoriasis. METHODS Between October 2003 and February 2004, six office-based dermatologists and eight dermatology outpatient departments retrospectively documented cost-of-illness data from a societal cost perspective in 184 patients over a 12-month period. Patients were stratified into three subgroups according to their treatment scheme. RESULTS Mean total costs amounted to euro 6,709 per patient and year. The mean PASI score was 18.2 and PBSA 28.9%. Annual costs were highest with euro 8,831 in high-need patients. They also showed the highest PASI score (22.2). CONCLUSION Moderate to severe plaque psoriasis is associated with tremendous costs, particularly in patients not adequately controlled by conventional therapies, while the outcomes of patients were unsatisfactory.
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Park KS, Park JS, Nam JH, Bang D, Sohn S, Lee ES. HLA-E*0101 and HLA-G*010101 reduce the risk of Behcet's disease. TISSUE ANTIGENS 2007; 69:139-44. [PMID: 17257316 DOI: 10.1111/j.1399-0039.2006.00742.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nonclassical human leukocyte antigen (HLA)-E and -G molecules have previously been shown to inhibit natural killer- and cytotoxic T-lymphocyte-mediated cell lysis and have also been shown to prevent the proliferation of CD4 T cells and secrete cytokines that appear to be important in the modulation of the Behcet's disease (BD) immune systems. Polymorphisms in the HLA-E and HLA-G genes have been associated with differential expression and function. Thus, we conducted an analysis of the HLA-E and HLA-G alleles using Amplification Refractory Mutation System-polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism techniques in a study comprising 312 patients with BD and 486 controls. The HLA-E*0101 and HLA-G*010101 alleles were associated with a reduced risk of BD (P = 0.0002, odds ratio (OR) = 0.7 and P = 0.002, OR = 0.7, respectively). By way of contrast, the variants HLA-E*010302, HLA-G*010102, G*0105N alleles and 3741_3754ins14bp were all associated with an increased risk of BD (P < 0.0001, OR = 1.6; P = 0.002, OR = 1.8; P = 0.024, OR = 2.0 and P = 0.003, OR = 1.4, respectively). Individuals carrying both the HLA-E*0101 and the HLA-G*010101 alleles evidenced significantly lower frequency in the patients than in the controls (35.6% vs 49.6%; P < 0.0001, OR = 0.6). These results indicate that variant HLA-E and HLA-G molecules appear to function independently and synergistically, increasing the risk of BD, and may result in an imbalance of lymphocytic functions, which may culminate in the development of BD.
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Sohn S, Kim EY, Gwag BJ. Glutamate neurotoxicity in mouse cortical neurons: atypical necrosis with DNA ladders and chromatin condensation. Neurosci Lett 1998; 240:147-50. [PMID: 9502225 DOI: 10.1016/s0304-3940(97)00936-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The possibility that glutamate may induce neuronal apoptosis was examined in cultured cortical neurons. Neurons underwent widespread death 24 h following exposure to 50 microM glutamate. The glutamate neurotoxicity was blocked by inclusion of the glutamate antagonists, 10 microM MK-801 and 50 microM CNQX. The death was characterized by swelling cell body and bursting cytoplasmic membrane in the early phase of degeneration, suggesting that glutamate produces receptor-mediated excitotoxic necrosis. With blockade of excitotoxicity by addition of 10 microM MK-801 and 50 microM CNQX, cortical neurons exposed to 2 mM glutamate underwent necrosis morphologically identical to excitotoxicity but sensitive to 100 microM trolox, an antioxidant, suggesting that high doses of glutamate produce oxidative neuronal necrosis via non-receptor-mediated mechanisms. Interestingly, internucleosomal DNA fragmentation and chromatin condensation were observed in the course of glutamate-induced neuronal necrosis.
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von Bahr-Lindström H, Jeck R, Woenckhaus C, Sohn S, Hempel J, Jörnvall H. Characterization of the coenzyme binding site of liver aldehyde dehydrogenase: differential reactivity of coenzyme analogues. Biochemistry 1985; 24:5847-51. [PMID: 4084495 DOI: 10.1021/bi00342a023] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The mitochondrial isozyme of horse liver aldehyde dehydrogenase was labeled with brominated [5-(3-acetylpyridinio)pentyl]diphosphoadenosine. Specific labeling of a coenzyme binding region was proven by an enzymatic activity of the isozyme with the nonbrominated coenzyme derivative, optical properties of the complex, stoichiometry of incorporation, and protection against inactivation. A cysteine residue was selectively modified by the brominated coenzyme analogue and was identified in a 35-residue tryptic peptide. This cysteine residue corresponds to Cys-302 of the cytoplasmic isozyme and has earlier been implicated in disulfiram binding, confirming a position close to the active site. In contrast, the butyl homologue of the coenzyme analogue labels another residue of the mitochondrial isozyme. Thus, in the same isozyme, two residues are selectively reactive. They are concluded to be close together in the tertiary structure and to be close enough to the coenzyme binding site to be differentially labeled by coenzyme analogues differing only by a single methylene group.
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Comparative Study |
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Mook-Jung I, Joo I, Sohn S, Kwon HJ, Huh K, Jung MW. Estrogen blocks neurotoxic effects of beta-amyloid (1-42) and induces neurite extension on B103 cells. Neurosci Lett 1997; 235:101-4. [PMID: 9406879 DOI: 10.1016/s0304-3940(97)00632-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Clinical studies have shown that estrogen replacement therapy is associated with reduced risk of Alzheimer's disease (AD). We tested whether or not estrogen blocks neurotoxic effects of beta-amyloid (1-42) (A beta1-42) on cultured B103 cells. A beta1-42 (1 microM) induced typical necrotic cell death, as revealed by light and electron microscopic examinations. Co-administration of estrogen not only blocked A beta1-42 toxicity to a large degree, but also enhanced neurite extension. Pretreatment with estrogen was even more effective in blocking A beta1-42 toxicity. When added 18 h after the beginning of A beta1-42 treatment, estrogen was still effective in halting the progress of cell death and enhancing neurite extension. The protection against A beta1-42-induced neuronal death by estrogen was unlikely due to a blockade of lipid peroxidation injury, since estrogen completely failed to attenuate ferrous chloride-induced cell death. These results demonstrate that estrogen blocks A beta1-42-induced neurotoxicity and enhances neurite extension on B103 cells, both of which may well be underlying mechanisms of beneficial effects of estrogen in AD.
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Sohn S, Rothman A, Shiota T, Luk G, Tong A, Swensson RE, Sahn DJ. Acute and follow-up intravascular ultrasound findings after balloon dilation of coarctation of the aorta. Circulation 1994; 90:340-7. [PMID: 8026016 DOI: 10.1161/01.cir.90.1.340] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND The study objective was to examine the vascular wall changes caused by balloon dilation of coarctation of the aorta (CoA) acutely and at short-term follow-up using intravascular ultrasound imaging. Intravascular ultrasound has been valuable in assessing the vessel wall changes in coronary and peripheral arteries after balloon dilation, often with more detail than angiography. METHODS AND RESULTS Intravascular ultrasound imaging, using 4.8F, 20-MHz or 6.2F, 12.5-MHz catheters on either Diasonics or HP scanners, was performed in 17 patients during balloon angioplasty for native (n = 12) and recurrent (n = 5) CoAs. Nine patients were also studied at the time of follow-up cardiac catheterization 28.1 +/- 18.0 months after angioplasty. Immediately after dilation, the mean pressure gradient across the CoA decreased from 42.9 +/- 16.4 to 9.0 +/- 5.4 mm Hg (P < .001) and the mean diameter of the coarcted segment increased from 4.4 +/- 1.9 to 7.9 +/- 2.4 mm (P < .001). An intimal tear or flap was noted by ultrasound in 12 of the 12 native CoAs and 4 of the 5 recoarctations. In contrast, only 6 of the native CoAs and 2 of the recoarctations had an intimal flap or dissection detected by angiography. At follow-up, the residual pressure gradient did not significantly change from that measured immediately after dilation, but the CoA diameter increased from 7.8 +/- 1.5 to 9.9 +/- 2.3 mm (P < .01). No aneurysms were detected. Four of the 9 patients showed ultrasonic and angiographic evidence of healing and remodeling with diminution in size or disappearance of the intimal tears. CONCLUSIONS There is a high incidence of intimal tears and dissections immediately after balloon angioplasty for native and recurrent CoAs. Intravascular ultrasound is more sensitive than angiography in detecting the vascular wall changes. Even significant intimal tears are not necessarily associated with aneurysm formation, and many decrease in size or disappear at short-term follow-up.
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Choi WS, Canzoniero LM, Sensi SL, O'Malley KL, Gwag BJ, Sohn S, Kim JE, Oh TH, Lee EB, Oh YJ. Characterization of MPP(+)-induced cell death in a dopaminergic neuronal cell line: role of macromolecule synthesis, cytosolic calcium, caspase, and Bcl-2-related proteins. Exp Neurol 1999; 159:274-82. [PMID: 10486196 DOI: 10.1006/exnr.1999.7133] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To further characterize MPP(+)-induced cell death and to explore the role of Bcl-2-related proteins in this death paradigm, we utilized a mesencephalon-derived dopaminergic neuronal cell line (MN9D) stably transfected with human bcl-2 (MN9D/Bcl-2), its C-terminal deletion mutant (MN9D/Bcl-2Delta22), murine bax (MN9D/Bax), or a control vector (MN9D/Neo). As determined by electron microscopy and TUNEL assay, MN9D/Neo cells exposed to MPP(+) underwent a cell death that was characterized by mitochondrial swelling and irregularly scattered heterochromatin without accompanying DNA fragmentation. However, cell swelling typically seen in necrosis did not appear. To examine the biochemical events associated with MPP(+)-induced cell death, various analyses were conducted. Addition of a broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (50-400 microM) or Boc-aspartyl(OMe)-fluoromethylketone (50-200 microM) did not attenuate MPP(+)-induced cell death while the same treatment protected MN9D/Neo cells against staurosporine-induced apoptotic cell death. Concurrent treatment with an inhibitor of macromolecule synthesis such as cycloheximide, emetine, or actinomycin D blocked MPP(+)-induced cell death, suggesting that new protein synthesis is required as demonstrated in many apoptotic cell death. The level of cytosolic calcium in MN9D/Neo cells was unchanged over 24 h following MPP(+) treatment, as monitored by means of the fluorescent probe Fura-2. Western blot analysis indicated that expression level of proapoptotic protein, Bax was not significantly altered after MPP(+) treatment. In this death paradigm, overexpression of Bcl-2 but not its C-terminal deletion mutant attenuated MPP(+)-induced cell death whereas overexpression of Bax had no effect. Taken together, these data indicate that (i) MPP(+) induces a distinct form of cell death which resembles both apoptosis and necrosis; and (ii) full-length Bcl-2 counters MPP(+)-induced morphological changes and cell death via a mechanism that is dependent on de novo protein synthesis but independent of cytosolic calcium changes, Bax expression, and/or activation of caspase(s) in MN9D cells.
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Sohn S, Wolpoff MH. Zuttiyeh face: a view from the East. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 1993; 91:325-47. [PMID: 8333489 DOI: 10.1002/ajpa.1330910307] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We analyze the phylogenetic position of the frontofacial fragment from Zuttiyeh, Israel. This specimen is dated to the Middle Pleistocene (the latest estimate is between 250 and 350 kyr) and is associated with the Acheulo-Yabrudian, which makes it the oldest cranium from the region. It has been previously regarded as a Neandertal, and early "anatomically modern Homo sapiens," and a generalized specimen ancestral to both. These different phylogenetic interpretations of its features have a historic basis but in our view also result from a confusion of grade and intraspecies clade as valid sources of variation. We show here that generally the differences that distinguish Zuttiyeh from Neandertals are similarities it shares with the Zhoukoudian remains. These similarities involve a unique combination of features, and suggest the possibility of an ancestral relationship. It is less likely that Middle Pleistocene remains from Europe or sub-Saharan Africa are uniquely or significantly ancestral to Zuttiyeh. An accurate understanding of the relationship between populations of eastern and western Asia is important for resolving the more general questions surrounding the position of the Upper Pleistocene Levant populations in human evolution, including (1) whether there are significantly different contemporary Mousterian populations in the Upper Pleistocene, (2) whether Neandertals are clearly intrusive in the region, and (3) whether there is an early appearance of (what many workers call) "anatomically modern Homo sapiens." The hypothesis of a recent unique African ancestry for all modern humans is disproved by our study, which shows Asia as a significant source area for at least some living populations.
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Comparative Study |
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Whitman WB, Sohn S, Kuk S, Xing R. Role of Amino Acids and Vitamins in Nutrition of Mesophilic Methanococcus spp. Appl Environ Microbiol 2010; 53:2373-8. [PMID: 16347458 PMCID: PMC204115 DOI: 10.1128/aem.53.10.2373-2378.1987] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study we found that autotrophic methanococci similar to Methanococcus maripaludis obtained up to 57% of their cellular carbon from exogenous amino acids. About 85% of the incorporation was into protein. Primarily nonpolar and basic amino acids and glycine were incorporated; only small amounts of acidic and some polar amino acids were taken up. An additional 10% of the incorporation was into the nucleic acid fraction. Because little CO(2) was formed from the C-amino acids, little metabolism of the amino acids occurred. Therefore the growth stimulation by amino acids was probably due to the sparing of anabolic energy requirements. Of the amino acids incorporated, only alanine was also a sole nitrogen source for these methanococci. In contrast, Methanococcus vannielii and "Methanococcus aeolicus" are autotrophic methanococci which did not incorporate amino acids and did not utilize alanine as a sole nitrogen source. Although glutamine served as a sole nitrogen source for the autotrophic methanococci and Methanococcus voltae, a heterotrophic methanococcus, growth was due to chemical deamination in the medium. M. voltae requires leucine and isoleucine for growth. However, these amino acids were not significant nitrogen sources, and alanine was not a sole nitrogen source for the growth of M. voltae. The branched-chain amino acids were not extensively metabolized by M. voltae. Pantoyl lactone and pantoic acid were readily incorporated by M. voltae. The intact vitamin pantothenate was neither stimulatory to growth nor incorporated. In conclusion, although amino acids and vitamins are nutritionally important to both autotrophic and heterotrophic methanococci, generally they are not subject to extensive catabolism.
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Journal Article |
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Noh JS, Kang HJ, Kim EY, Sohn S, Chung YK, Kim SU, Gwag BJ. Haloperidol-induced neuronal apoptosis: role of p38 and c-Jun-NH(2)-terminal protein kinase. J Neurochem 2000; 75:2327-34. [PMID: 11080184 DOI: 10.1046/j.1471-4159.2000.0752327.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examined patterns and mechanisms of cell death induced by haloperidol. Cortical cell cultures exposed to 10-100 microM: haloperidol for 24 h underwent neuronal death without injuring glia. The degenerating neurons showed hallmarks of apoptosis, featuring cell body shrinkage, nuclear chromatin condensation and aggregation, nuclear membrane disintegration with intact plasma membrane, and prominent internucleosomal DNA fragmentation. Neither glutamate antagonists nor antioxidants prevented the haloperidol-induced neuronal apoptosis. The c-Jun-NH(2)-terminal protein kinase and p38 mitogen-activated protein kinase were activated within 1 h and were sustained over the next 3 h following exposure of cortical neurons to 30 microM haloperidol. Haloperidol-induced neuronal apoptosis was partially attenuated by 10-30 microM PD169316, a selective inhibitor of p38 mitogen-activated protein kinase. Inclusion of 1 microg/ml cycloheximide, a protein synthesis inhibitor, or 100 ng/ml insulin prevented activation of both kinases and subsequent neuronal death. The present study demonstrates that cortical neurons exposed to haloperidol undergo apoptosis depending on activation of p38 mitogen-activated protein kinase and c-Jun-NH(2)-terminal protein kinase sensitive to cycloheximide and insulin.
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Kim E, Sohn S, Lee M, Jung J, Kineman RD, Park S. Differential responses of the growth hormone axis in two rat models of streptozotocin-induced insulinopenic diabetes. J Endocrinol 2006; 188:263-70. [PMID: 16461552 DOI: 10.1677/joe.1.06501] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The impact of streptozotocin (STZ)-induced, insulinopenic diabetes on the GH axis of rats and mice differs from study to study, where this variation may be related to the induction scheme, severity of the diabetes and/or the genetic background of the animal model used. In order to begin differentiate between these possibilities, we compared the effects of two different STZ induction schemes on the GH axis of male Sprague-Dawley rats: (1) a single high-dose injection of STZ (HI STZ, 80 mg/kg, i.p.), which results in rapid chemical destruction of the pancreatic beta-cells, and (2) multiple low-dose injections of STZ (LO STZ, 20 mg/kg for 5 consecutive days, i.p.), which results in a gradual, autoimmune destruction of beta-cells. STZ-treated animals were killed after 3 weeks of hyperglycemia (>400 mg/dl), and in both paradigms circulating insulin levels were reduced to <40% of vehicle-treated controls. HI STZ-treated rats lost weight, while body weights of LO STZ-treated animals gradually increased over time, similar to vehicle-treated controls. As previously reported, HI STZ resulted in a decrease in circulating GH and IGF-I levels which was associated with a rise in hypothalamic neuropeptide Y (NPY) mRNA (355% of vehicle-treated controls) and a fall in GH-releasing hormone (GHRH) mRNA (45% of vehicle-treated controls) levels. Changes in hypothalamic neuropeptide expression were reflected by an increase in immunoreactive NPY within the arcuate and paraventricular nuclei and a decrease in GHRH immunoreactivity in the arcuate nucleus, as assessed by immunohistochemistry. Consistent with the decline in circulating GH and hypothalamic GHRH, pituitary GH mRNA levels of HI STZ-treated rats were 58% of controls. However, pituitary receptor mRNA levels for GHRH and ghrelin increased and those for somatostatin (sst2, sst3 and sst5) decreased following HI STZ treatment. The impact of LO STZ treatment on the GH axis differed from that observed following HI STZ treatment, despite comparable changes in circulating glucose and insulin. Specifically, LO STZ treatment did suppress circulating IGF-I levels to the same extent as HI STZ treatment; however, the impact on hypothalamic NPY mRNA levels was less dramatic (158% of vehicle-treated controls) where NPY immunoreactivity was increased only within the paraventricular nucleus. Also, there were no changes in circulating GH, hypothalamic GHRH or pituitary receptor expression following LO STZ treatment, with the exception that pituitary sst3 mRNA levels were suppressed compared with vehicle-treated controls. Taken together these results clearly demonstrate that insulinopenia, hyperglycemia and reduced circulating IGF-I levels are not the primary mediators of hypothalamic and pituitary changes in the GH axis of rats following HI STZ treatment. Changes in the GH axis of HI STZ-treated rats were accompanied by weight loss, and these changes are strikingly similar to those observed in the fasted rat, which suggests that factors associated with the catabolic state are critical in modifying the GH axis following STZ-induced diabetes.
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Research Support, N.I.H., Extramural |
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Sher G, Maassarani G, Zouves C, Feinman M, Sohn S, Matzner W, Chong P, Ching W. The use of combined heparin/aspirin and immunoglobulin G therapy in the treatment of in vitro fertilization patients with antithyroid antibodies. Am J Reprod Immunol 1998; 39:223-5. [PMID: 9553645 DOI: 10.1111/j.1600-0897.1998.tb00357.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
PROBLEM To compare the effect of heparin/aspirin therapy alone vs. heparin/aspirin in combination with intravenous immuno-globulin (IVIg) immunotherapy on in vitro fertilization (IVF) outcome of patients who test positive for antithyroid antibodies (ATAs). METHOD OF STUDY Eighty-two women younger than 40 years of age whose infertility was related exclusively to female causes were evaluated. All tested positive for organ-specific antithyroid antibodies (antimicrosomal and/or antithyroglobulin antibodies), but negative for antiphospholipid antibodies. Thirty-seven of these women (group A) received H/A alone, whereas 45 (group B) received heparin/aspirin in combination with IVIg. RESULTS Ten (27%) of women in group A and 23 (51%) of women in group B achieved live births after completion of a single IVF/embryo transfer cycle (P = 0.027). CONCLUSION We conclude that IVIg therapy significantly improves IVF success rates in ATA+ women.
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Clinical Trial |
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Sohn S, Jaitovitch-Groisman I, Benlimame N, Galipeau J, Batist G, Alaoui-Jamali MA. Retroviral expression of the hepatitis B virus x gene promotes liver cell susceptibility to carcinogen-induced site specific mutagenesis. Mutat Res 2000; 460:17-28. [PMID: 10856831 DOI: 10.1016/s0921-8777(00)00010-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mutational inactivation of the tumor suppressor gene p53 is common in hepatocellular carcinomas (HCC). AGG to AGT transversion in codon 249 of exon 7 of the p53 gene occurs in over 50% of HCC from endemic regions, where both chronic infection with the hepatitis B virus (HBV) and exposure to carcinogens such as aflatoxin B1 (AFB1) prevail. In this study, we report the effect of the HBV x protein (HBx) on carcinogen-induced cytotoxicity and AGG to AGT mutation in codon 249 of the p53 gene in the human liver cell line CCL13. Expression of HBx, as revealed by its transactivation function, results in enhanced cell susceptibility to cytotoxicity induced by the AFB1 active metabolite, AFB1-8,9-epoxide, and benzo(a)pyrene diol-epoxide. Under similar conditions, expression of HBx promotes apoptosis in a subset of cell population. Exposure to AFB1-8, 9-epoxide alone induces a low frequency of AGG to AGT mutation in codon 249 of the p53 gene, as determined by an allele-specific polymerase chain reaction (AS-PCR) assay. However, expression of HBx enhances the frequency of AFB1-epoxide-induced AGG to AGT mutation compared to control cells. In summary, this study demonstrates that expression of HBx enhances liver cell susceptibility to carcinogen-induced mutagenesis, possibly through alteration of the balance between DNA repair and apoptosis, two cellular defense mechanisms against genotoxic stress.
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Oh YH, Jeong SR, Kim JH, Song KJ, Kim K, Park S, Sohn S, Shin HJ. Cytopathic changes and pro-inflammatory cytokines induced by Naegleria fowleri trophozoites in rat microglial cells and protective effects of an anti-Nfa1 antibody. Parasite Immunol 2006; 27:453-9. [PMID: 16255744 DOI: 10.1111/j.1365-3024.2005.00799.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Naegleria fowleri, a free-living amoeba, causes fatal primary amoebic meningoencephalitis in experimental animals and humans. The nfa1 gene (360 bp) was previously cloned from a cDNA library of pathogenic N. fowleri by immunoscreening, and produced a 13.1-kDa recombinant protein that showed pseudopodia-specific localization by immunocytochemistry. On the basis of an idea that the pseudopodia-specific Nfa1 protein seems to be involved in the pathogenicity of N. fowleri, the cytopathic activity of N. fowleri trophozoites co-cultured with rat microglial cells was observed, and the effects of an anti-Nfa1 antibody in a co-culture system were elucidated. Using light, scanning and transmission electron microscopy, it was seen that N. fowleri trophozoites in contact with microglial cells produced vigorous pseudopodia and a food-cup structure. Microglial cells were destroyed by N. fowleri trophozoites as seen from necrotic cell death in a time-dependent manner. In a(51)Cr release assay, N. fowleri showed 17.8%, 24.9%, 54.6% and 98% cytotoxicity against microglial cells at 3, 6, 12 and 24 h post-incubation, respectively. However, when anti-Nfa1 antibody was added in a coculture system, N. fowleri cytotoxicity was reduced to 15.5%, 20.3%, 46.7% and 66.9%, respectively. Moreover, microglial cells co-cultured with N. fowleri trophozoites secreted the pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-6. In the presence of anti-Nfa1 antibody, the secretion of TNF-alpha was slightly, but not significantly, decreased.
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Research Support, Non-U.S. Gov't |
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In SI, Yi SW, Kang HY, Lee ES, Sohn S, Kim YC. Clinical and histopathological characteristics of pityriasis alba. Clin Exp Dermatol 2009; 34:591-7. [DOI: 10.1111/j.1365-2230.2008.03038.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sohn S, Park Y, Srikanth S, Arai A, Song M, Yu B, Shin KH, Kang MK, Wang C, Gwack Y, Park NH, Kim RH. The Role of ORAI1 in the Odontogenic Differentiation of Human Dental Pulp Stem Cells. J Dent Res 2015; 94:1560-7. [PMID: 26403672 DOI: 10.1177/0022034515608128] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Pulp capping, or placing dental materials directly onto the vital pulp tissues of affected teeth, is a dental procedure that aims to regenerate reparative dentin. Several pulp capping materials are clinically being used, and calcium ion (Ca(2+)) released from these materials is known to mediate reparative dentin formation. ORAI1 is an essential pore subunit of store-operated Ca(2+) entry (SOCE), which is a major Ca(2+) influx pathway in most nonexcitable cells. Here, we evaluated the role of ORAI1 in mediating the odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs). During the odontogenic differentiation of DPSCs, the expression of ORAI1 increased in a time-dependent manner. DPSCs knocked down with ORAI1 shRNA (DPSC/ORAI1sh) or overexpressed with dominant negative mutant ORAI1(E106Q) (DPSC/E106Q) exhibited the inhibition of Ca(2+) influx and suppression of odontogenic differentiation and mineralization as demonstrated by alkaline phosphatase (ALP) activity/staining as well as alizarin red S staining when compared with DPSCs of their respective control groups (DPSC/CTLsh and DPSC/CTL). The gene expression for odontogenic differentiation markers such as osteocalcin, bone sialoprotein, and dentin matrix protein 1 (DMP1) was also suppressed. When DPSC/CTL or DPSC/E106Q cells were subcutaneously transplanted into nude mice, DPSC/CTL cells induced mineralized tissue formation with significant increases in ALP and DMP1 staining in vivo, whereas DPSC/E106Q cells did not. Collectively, our data showed that ORAI1 plays critical roles in the odontogenic differentiation and mineralization of DPSCs by regulating Ca(2+) influx and that ORAI1 may be a therapeutic target to enhance reparative dentin formation.
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Research Support, Non-U.S. Gov't |
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Sohn S, Kim HS, Lee SW. Multidetector row computed tomography for follow-up of patients with coronary artery aneurysms due to Kawasaki disease. Pediatr Cardiol 2004; 25:35-39. [PMID: 14583832 DOI: 10.1007/s00246-003-0559-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Multidetector row computed tomography (MDCT) coronary angiography was performed using a 16-slice MDCT scanner in three children with coronary aneurysms due to Kawasaki disease. Patients were given a beta-blocker. Following contrast injection, all data were acquired during a 20-second breathhold. Results were compared with those of conventional coronary angiography performed previously. MDCT provided clear visualization of coronary artery aneurysms, with coronary calcifications but which had not yet progressed to stenotic lesions. Because MDCT allows noninvasive detection and exclusion of coronary obstructions, it may be able to replace repeat conventional angiography as a follow-up study for children with coronary artery disease.
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Case Reports |
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Abstract
BACKGROUND Melanocyte number and the amount of melanin pigment are related to diagnosis and treatment of pigmentary skin diseases. Various histologic methods are used, such as Fontana-Masson stain for melanin pigment or immunohistochemical stain for melanocytes. Recently, computerized image analysis has been applied to many fields to avoid interobserver bias. In this study, we applied a computerized image analysis to assess the melanin content and melanocyte density of human epidermis. METHODS We evaluated the skin biopsy specimens (paraffin blocks) from normal human skin (33 +/- 6.6, n = 11) and diseased skins; vitiligo (32 +/- 10.0, n = 8), melasma (35 +/- 8.6, n = 11), and lentigo senilis (40 +/- 7.2, n = 11) (mean age +/- SD). Each specimen was stained with Fontana-Masson for melanin pigments and immunohistochemical method for melanocytes. Quantitative analysis of melanin pigment and melanocyte number (density) were investigated through two methods: (1) two dermatologists measured the visual scales; and (2) computerized image analysis was used to measure melanin content indices (MCI). The data were evaluated using one-way ANOVA. RESULTS The visual scale of the Fontana-Masson stain was the highest for lentigo senilis (3.8 +/- 0.40), followed by melasma (2.6 +/- 0.67), normal skin (1.8 +/- 0.60) and vitiligo (0) (P < 0.05). These findings were consistent with objective measurements made by computerized image analysis. MCI values were 120.3 +/- 20.74 for lentigo senilis, 81.1 +/- 19.27 for melasma, 45.5 +/- 16.92 for normal skin, and 0.3 +/- 0.30 for vitiligo in decreasing order (P < 0.05). MC/1E (melanocyte number per 1 mm epidermis) was about two fold larger in lentigo senilis (18.1 +/- 8.92) than melasma (9.7 +/- 2.40) or normal skin (9.3 +/- 2.67) (P < 0.05). MC/1B (melanocyte number per 1 mm basal layer) was about 1.5 fold higher in lentigo senilis (13.5 +/- 4.17), compared to normal skin (9.0 +/- 3.55) (P < 0.05). Melasma showed increased melanocyte numbers compared to normal skin, but it was not statistically significant (P > 0.05). CONCLUSION We believe this computerized image analysis could be useful tool for diagnosis and comparison of interval changes in pigmentary diseases like melasma or lentigo senilis by quantifying melanin pigments or melanocytes in skin biopsy specimens.
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