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Liu KH, Chang WH, Lai ECC, Tsai PC, Hsu B, Yang YH, Lin WR, Huang TS, Su FY, Chiang JH, Li CY, Tsai YS, Sung JM. Ambient temperature and the occurrence of intradialytic hypotension in patients receiving hemodialysis. Clin Kidney J 2024; 17:sfad304. [PMID: 38213491 PMCID: PMC10783262 DOI: 10.1093/ckj/sfad304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Indexed: 01/13/2024] Open
Abstract
Background Intradialytic hypotension (IDH) is a common hemodialysis complication causing adverse outcomes. Despite the well-documented associations of ambient temperatures with fluid removal and pre-dialysis blood pressure (BP), the relationship between ambient temperature and IDH has not been adequately studied. Methods We conducted a cohort study at a tertiary hospital in southern Taiwan between 1 January 2016 and 31 October 2021. The 24-h pre-hemodialysis mean ambient temperature was determined using hourly readings from the weather station closest to each patient's residence. IDH was defined using Fall40 [systolic BP (SBP) drop of ≥40 mmHg] or Nadir90/100 (SBP <100 if pre-dialysis SBP was ≥160, or SBP <90 mmHg). Multivariate logistic regression with generalizing estimating equations and mediation analysis were utilized. Results The study examined 110 400 hemodialysis sessions from 182 patients, finding an IDH prevalence of 11.8% and 10.4% as per the Fall40 and Nadir90/100 criteria, respectively. It revealed a reverse J-shaped relationship between ambient temperature and IDH, with a turning point around 27°C. For temperatures under 27°C, a 4°C drop significantly increased the odds ratio of IDH to 1.292 [95% confidence interval (CI) 1.228 to 1.358] and 1.207 (95% CI 1.149 to 1.268) under the Fall40 and Nadir90/100 definitions, respectively. Lower ambient temperatures correlated with higher ultrafiltration, accounting for about 23% of the increased IDH risk. Stratified seasonal analysis indicated that this relationship was consistent in spring, autumn and winter. Conclusion Lower ambient temperature is significantly associated with an increased risk of IDH below the threshold of 27°C, irrespective of the IDH definition. This study provides further insight into environmental risk factors for IDH in patients undergoing hemodialysis.
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Affiliation(s)
- Kuan-Hung Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Hsiang Chang
- Department of Food Safety/ Hygiene and Risk Management, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Research Center of Environmental Trace Toxic Substances, National Cheng Kung University, Tainan, Taiwan
| | - Edward Chia-Cheng Lai
- School of Pharmacy, Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Pei-Chen Tsai
- Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Bin Hsu
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Hsuan Yang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Ren Lin
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tzu-Shan Huang
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Fang-Yi Su
- Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Jung-Hsien Chiang
- Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Chung-Yi Li
- Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan
- Department of Healthcare Administration, College of Medical and Health Science, Asia University, Taichung, Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Junne-Ming Sung
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Lin WR, Liu KH, Ling TC, Wang MC, Lin WH. Role of antidiabetic agents in type 2 diabetes patients with chronic kidney disease. World J Diabetes 2023; 14:352-363. [PMID: 37122432 PMCID: PMC10130897 DOI: 10.4239/wjd.v14.i4.352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/10/2023] [Accepted: 04/04/2023] [Indexed: 04/12/2023] Open
Abstract
Insulin resistance is a condition in which the target tissues have a decreased response to insulin signaling, resulting in glucose uptake defect, and an increased blood sugar level. Pancreatic beta cells thus enhance insulin production to compensate. This situation may cause further beta cell dysfunction and failure, which can lead diabetes mellitus (DM). Insulin resistance is thus an important cause of the development of type 2 DM. Insulin resistance has also been found to have a strong relationship with cardiovascular disease and is common in chronic kidney disease (CKD) patients. The mechanisms of insulin resistance in CKD are complex and multifactorial. They include physical inactivity, inflammation and oxidative stress, metabolic acidosis, vitamin D deficiency, adipose tissue dysfunction, uremic toxins, and renin-angiotensin-aldosterone system activation. Currently, available anti-diabetic agents, such as biguanides, sulfonylureas, thiazolidinediones, alfa-glucosidase inhibitors, glucagon-like peptide-1-based agents, and sodium-glucose co-transporter-2 inhibitors, have different effects on insulin resistance. In this short review, we describe the potential mechanisms of insulin resistance in CKD patients. We also review the interaction of currently available anti-diabetic medications with insulin resistance.
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Affiliation(s)
- Wei-Ren Lin
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Kuan-Hung Liu
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Tsai-Chieh Ling
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Ming-Cheng Wang
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
| | - Wei-Hung Lin
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan
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Huang TC, Lin WR. Severe unilateral diffuse alveolar hemorrhage: an unusual presentation of microscopic polyangiitis. Clin Rheumatol 2023; 42:971-972. [PMID: 36529805 DOI: 10.1007/s10067-022-06468-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Teng-Ching Huang
- Department of Internal Medicine, Division of Nephrology, National Cheng Kung University Hospital, Tainan City, Taiwan
| | - Wei-Ren Lin
- Department of Internal Medicine, Division of Nephrology, National Cheng Kung University Hospital, Tainan City, Taiwan.
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Liu KH, Lee SH, Lin WR, Tsai YS, Sung JM. Recovery of severe dialysis disequilibrium syndrome with uncal herniation following therapy with mannitol, hyperventilation and hypertonic saline. Clin Kidney J 2022; 15:165-167. [PMID: 35035947 PMCID: PMC8757411 DOI: 10.1093/ckj/sfab165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Indexed: 11/25/2022] Open
Abstract
Dialysis disequilibrium syndrome (DDS) is a rare complication of dialysis, especially with the general application of preventive strategies. Severe DDS with brain herniation is believed to be fatal. We present a patient presenting with bilateral uncal herniation after receiving two dialysis sessions with low-efficiency settings. Serial brain magnetic resonance imaging studies showed the temporal evolution of DDS-induced cerebral edema. With aggressive treatment of hypertonic saline and mannitol, the patient made a remarkable recovery. This case highlights that we should be cautious about this severe complication of dialysis even with preventive strategies, and recovery is possible with prompt recognition and treatment.
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Affiliation(s)
- Kuan-Hung Liu
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shao-Hua Lee
- Department of Diagnostic Radiology, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Wei-Ren Lin
- Department of Internal Medicine, National Cheng Kung University Hospital, Dou-Liou Branch, Yun-Lin County, Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center for Clinical Medicine Research, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Junne-Ming Sung
- Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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See CY, Tseng CT, Lin WR, Chao JY, Kuo TH, Wang MC. Seasonal Change in Home Blood Pressure Monitoring Is Associated With Renal Outcome and Mortality in Patients With Chronic Kidney Disease. Front Med (Lausanne) 2021; 8:672651. [PMID: 34124101 PMCID: PMC8192714 DOI: 10.3389/fmed.2021.672651] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/20/2021] [Indexed: 01/30/2023] Open
Abstract
Background: Blood pressure (BP) variation may result in poor cardiovascular and renal outcomes. We investigated the pattern of seasonal BP change and its association with outcomes in patients with chronic kidney disease (CKD) living in southern Taiwan. Methods: We conducted a retrospective analysis of a prospective observational cohort consisting of outpatients with CKD for the period between December 2014 and December 2019. These patients were grouped according to the pattern of seasonal BP variation, namely, consistently higher average systolic BP (≥8 mmHg) in wintertime than summertime (Group A), consistently lower average systolic BP (≥8 mmHg) in wintertime than summertime (Group B), large variation of average systolic BP (≥8 mmHg) without a specific pattern related to weather (Group C), and little fluctuation of average systolic BP (<8 mmHg) throughout the years (Group D). The study endpoints were ≥40% reduction in estimated glomerular filtration rate (eGFR), end stage renal disease (initiation of dialysis or transplantation), or death. Results: We analyzed 507 eligible patients, of whom 17.2% exhibited consistent BP elevation in the wintertime. There were 56.8% of patients conducting regular home BP monitoring. Cox regression analysis showed home BP monitoring was independently associated with better outcome in 507 CKD patients (HR 0.72, 95% CI 0.56–0.94, P = 0.0162). Compared with the other three groups, patients with BP elevation in the wintertime (Group A) were older, had a higher prevalence of diabetic nephropathy and nephrotoxic agent use, a lower prevalence of statin use, higher eGFR decline rate, and a worse outcome. Patients with BP reduction in the wintertime (Group B) were associated with the best outcome. Cox regression analysis indicated that consistent BP elevation in the wintertime in 288 CKD patients with home BP monitoring was significantly associated with a worse composite outcome (i.e., ≥40% reduction in eGFR, end stage renal disease, or death) after adjustment for various confounding factors. Conclusion: Home BP monitoring is crucial, and associated with better outcome in CKD patients. Consistent home BP elevation from summertime to wintertime in patients with CKD was associated with a poorer composite outcome.
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Affiliation(s)
- Chun Yin See
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chien-Tzu Tseng
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Ren Lin
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jo-Yen Chao
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Te-Hui Kuo
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ming-Cheng Wang
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Hou DS, Cheng XK, Feng JZ, Yang M, Lin WR, Li X, Sun XC. [Thymic tubular adenocarcinoma: report of a case]. Zhonghua Bing Li Xue Za Zhi 2018; 47:475-476. [PMID: 29886599 DOI: 10.3760/cma.j.issn.0529-5807.2018.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Lv XJ, Zhang JJ, Wang T, Duan RP, Lin WR. Endoscopically guided titanium clip therapy and adrenaline injection for treatment of patients with peptic ulcer bleeding: Clinical efficacy and impact on serum inflammatory cytokines. Shijie Huaren Xiaohua Zazhi 2018; 26:99-104. [DOI: 10.11569/wcjd.v26.i2.99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the clinical efficacy of endoscopically guided titanium clip therapy and adrenaline injection in the treatment of patients with peptic ulcer bleeding and the impact on serum inflammatory cytokines.
METHODS One hundred and thirty-two patients with peptic ulcer bleeding treated from January 2015 to December 2016 were divided into either an observation group or a control group. The control group was given endoscopically guided titanium clip therapy, and the observation group was given endoscopically guided titanium clip therapy and adrenaline injection. Therapeutic indicators, serum inflammatory cytokines, adverse reactions, and clinical efficacy were compared between the two groups.
RESULTS The effective rate was significantly higher in the observation group than in the control group (98.48% vs 89.39%, χ2 = 4.790, P < 0.05). Time to achieve hemostasis, blood loss, amount of blood transfusion, and hospital stay were significantly lower in the observation group than in the control group (t = 6.842, 5.384, 6.772, and 9.407, respectively, P < 0.05 or 0.01). Serum levels of interleukin (IL)-6 and C-reaction protein were significantly lower and that of IL-10 was significantly higher in the observation group than in the control group (t = 7.545, 6.071, and 8.919, respectively, P < 0.05 or 0.01). The rates of perforation, infection, and rebleeding were significantly lower in the observation group than in the control group (3.03% vs 12.12%, 6.06% vs 18.18%, and 1.52% vs 10.61%; χ2 = 3.895, 4.552, and 4.790, respectively; P < 0.05).
CONCLUSION Endoscopically guided titanium clip therapy and adrenaline injection can improve the therapeutic effect in patients with peptic ulcer bleeding and reduce adverse reactions, which may be related to the alleviation of the inflammatory state.
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Affiliation(s)
- Xiao-Jin Lv
- Endoscopy Center, Taizhou Cancer Hospital, Taizhou 317500, Zhejiang Province, China
| | - Jing-Jing Zhang
- Endoscopy Center, Taizhou Cancer Hospital, Taizhou 317500, Zhejiang Province, China
| | - Ting Wang
- Endoscopy Center, Taizhou Cancer Hospital, Taizhou 317500, Zhejiang Province, China
| | - Ru-Ping Duan
- Endoscopy Center, Taizhou Cancer Hospital, Taizhou 317500, Zhejiang Province, China
| | - Wei-Ren Lin
- Department of Internal Medicine, Taizhou Cancer Hospital, Taizhou 317500, Zhejiang Province, China
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9
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Chen YT, Zhu F, Lin WR, Ying RB, Yang YP, Zeng LH. The novel EZH2 inhibitor, GSK126, suppresses cell migration and angiogenesis via down-regulating VEGF-A. Cancer Chemother Pharmacol 2016; 77:757-65. [PMID: 26898301 DOI: 10.1007/s00280-016-2990-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/08/2016] [Indexed: 12/13/2022]
Abstract
PURPOSE To explore the effects and mechanisms of GSK126, a novel inhibitor of histone methyltransferase enhancer of zeste homologue 2, on cancer cell migration. METHODS Gastric cancer cell line MGC803 and human lung adenocarcinoma cell line A549 were treated with GSK126 at three doses. Transwell and wound healing assays were conducted to detect cell migration. Human umbilical vein endothelial cells tube formation assay and chick embryo chorioallantoic membrane assay were performed to assess the effects of GSK126 on angiogenesis in vitro and in vivo, respectively. The mRNA level of VEGF-A was detected by quantitative PCR, and the protein levels of VEGF-A were detected both by western blot analysis and immunohistochemistry. Epi-fluorescent intensity was obtained by in vivo imaging. RESULTS GSK126 inhibited cell migration in both MGC803 and A549 in a dose-dependent manner, as revealed by transwell and wound healing assays. The effects of GSK 126 were similar to those of gefitinib at the same doses. Moreover, GSK126 at doses of 20 and 50 µM inhibited angiogenesis both in vitro and in vivo. GSK126 reduced both the mRNA and protein expression of VEGF-A in a dose-dependent manner. Finally, in vivo imaging assay revealed that GSK126 at 200 mg/kg significantly inhibited cancer cell migration. CONCLUSIONS GSK126 inhibits cell migration and angiogenesis in solid tumor cell lines through down-regulation of VEGF-A expression. Thus, it may be considered as a novel anticancer drug candidate for solid tumor.
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Affiliation(s)
- Ya-Tian Chen
- Department of Pharmacy, School of Medicine, Zhejiang University City College, 50 Huzhou Rd, Hangzhou, 310015, Zhejiang, China
| | - Feng Zhu
- Department of Pharmacy, School of Medicine, Zhejiang University City College, 50 Huzhou Rd, Hangzhou, 310015, Zhejiang, China
| | - Wei-Ren Lin
- Taizhou Cancer Hospital, Wenling, 317500, Zhejiang, China
| | - Rong-Biao Ying
- Taizhou Cancer Hospital, Wenling, 317500, Zhejiang, China
| | - You-Ping Yang
- Taizhou Cancer Hospital, Wenling, 317500, Zhejiang, China
| | - Ling-Hui Zeng
- Department of Pharmacy, School of Medicine, Zhejiang University City College, 50 Huzhou Rd, Hangzhou, 310015, Zhejiang, China.
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Jao Y, Wu SW, Lin TY, Hung CT, Yang PW, Huang CH, Lin CY, Lin WR, Chen YH, Lu PL. Free-flow duration prior as an influential factor on microorganism and endotoxin amount of reverse osmosis water for dialysis. Antimicrob Resist Infect Control 2015. [PMCID: PMC4474847 DOI: 10.1186/2047-2994-4-s1-p65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Cheng KY, Wang JC, Lin CY, Lin WR, Chen YA, Tsai FJ, Chuang YC, Lin GY, Ni CW, Zeng YT, Ho ML. Electrochemical synthesis, characterization of Ir–Zn containing coordination polymer, and application in oxygen and glucose sensing. Dalton Trans 2014; 43:6536-47. [DOI: 10.1039/c3dt53504e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhu B, Cheng H, Qiao Y, Liu C, Shi Y, Zhang K, Sun D, Lin W. Porosity and permeability evolution and evaluation in anisotropic porosity multiscale-multiphase-multicomponent structure. Chin Sci Bull 2012. [DOI: 10.1007/s11434-011-4874-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Thom M, Sisodiya SM, Lin WR, Mitchell T, Free SL, Stevens J, Scaravilli F. Bilateral isolated hippocampal malformation in temporal lobe epilepsy. Neurology 2002; 58:1683-6. [PMID: 12058101 DOI: 10.1212/wnl.58.11.1683] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Hippocampal malformations in patients with epilepsy usually are reported in the context of widespread cortical malformations. Isolated hippocampal malformations are more rarely identified in MRI studies with little documentation of their pathologic appearance. Postmortem examination revealed abnormal position and complex convolutional malformations isolated to the hippocampal formation in an adult with temporal lobe epilepsy in whom MRI demonstrated bilateral hippocampal abnormalities.
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Affiliation(s)
- M Thom
- Department of Clinical and Esperimental Epilepsy, Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, United Kingdom.
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Abstract
Herpes simplex encephalitis (HSE) is a rare but very serious disorder caused by herpes simplex type 1 virus (HSV-1). Treatment with acyclovir decreases mortality but many patients still suffer cognitive impairment subsequently. A vaccine against HSV1 would therefore be of great value. HSV-1 has been implicated also in Alzheimer's disease (AD): we established that HSV1 resides in the brain of about two thirds of AD patients and aged normal people, and that in carriers of the type 4 allele of the apolipoprotein E gene, it is a strong risk factor for AD. Thus a vaccine against HSV-1 might prevent development of AD in some cases. To find whether a vaccine of mixed HSV-1 glycoproteins (ISCOMs), which protects mice from latent HSV-1 infection of sensory ganglia, prevents HSV1 latency in the CNS, ISCOM-vaccinated or unvaccinated animals were infected with HSV-1. Using polymerase chain reaction (PCR) we detected HSV-1 in brain from 16 of 39 unvaccinated mice (41%), but only 3 of 41 vaccinated mice (7%) (P < 0.001). Thus, ISCOMs protect the CNS also, suggesting their possible future usage in humans.
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Affiliation(s)
- W R Lin
- University of Manchester Institute of Science & Technology, Molecular Neurobiology Laboratory, Department of Optometry & Neuroscience, M60 1QD, Manchester, UK
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Tsai HC, Liu YC, Kunin CM, Lee SS, Chen YS, Lin HH, Tsai TH, Lin WR, Huang CK, Yen MY, Yen CM. Eosinophilic meningitis caused by Angiostrongylus cantonensis: report of 17 cases. Am J Med 2001; 111:109-14. [PMID: 11498063 DOI: 10.1016/s0002-9343(01)00766-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To describe two outbreaks of Angiostrongylus cantonensis infection that occurred in Kaohsiung, Taiwan, during 1998 and 1999, and to characterize the source of the outbreaks and the clinical manifestations of the disease. SUBJECTS AND METHODS We performed a retrospective cohort study among Thai laborers with eosinophilic meningitis who ate raw snails (Ampullarium canaliculatus), as well as an environmental surveillance of larvae in snails. RESULTS We enrolled 17 Thai laborers in whom severe headache and eosinophilia developed within 4 to 23 days after eating raw snails. Twelve (71%) developed eosinophilic meningitis. Third-stage larvae were found in the cerebrospinal fluids of 2 patients and in all 12 tested snails. Specific antibodies to A. cantonensis were detected in serum from 16 of the patients and in cerebrospinal fluid from 5 of the patients. Central nervous system manifestations included headache (n = 17 [100%]), fever (n = 11 [65%]), Brudzinski's sign/stiff neck (n = 11 [65%]), hyperesthesia (n = 3 [18%]), cranial nerve palsy (n = 2 [12%]), diplopia (n = 2 [12%]), and ataxia (n = 1 [6%]). Laboratory findings included peripheral eosinophilia (n = 15 [88%]) and cerebrospinal fluid eosinophilia (n = 12 [71%]); elevated immunoglobulin (Ig) E levels (n = 13 [100%]); and transient increases in white blood cell count (n = 7 [41%]) and in serum levels of creatine kinase (n = 7 [41%]), transaminase (n = 3 [18%]), and lactate dehydrogenase (n = 2 [12%]). The severity of illness and eosinophilia were correlated with the number of ingested snails. Meningeal and basal ganglion enhancement was noted on magnetic resonance imaging in several patients. Treatment with mebendazole combined with glucocorticosteroids appeared to shorten the course of the infection, but not the number of relapses. The eosinophil count fell to normal within 3 months, but IgE levels remained elevated for as long as 6 months. All patients recovered with minimal neurologic sequelae. CONCLUSION Eosinophilic meningitis caused by A. cantonensis should be considered in patients who have headache or central nervous system manifestations after eating raw snails.
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Affiliation(s)
- H C Tsai
- Department of Medicine, Section of Infectious Diseases, Veterans General Hospital-Kaohsiung, Kaohsiung, Taiwan
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Abstract
Cajal-Retzius (CR) cells are early-developing cells important in mammalian corticogenesis. Reelin, a protein secreted by CR cells, is essential for completion of neuronal migration and cortical lamination. Lack of reelin causes the 'reeler' phenotype in mice and autosomal recessive lissencephaly with cerebellar hypoplasia in man. Focal increases in reelin and CR cells are associated with thickening and local invaginations of the marginal zone and microgyria in animal studies. It has been suggested that abnormalities of reelin expression may be involved in human polymicrogyria. We have studied CR cells and reelin expression in pathological sections of human polymicrogyria to explore this possibility. Occurrence, distribution, morphology and reelin expression in CR cells were studied in 12 cases of human polymicrogyria, ranging from 21 gestational weeks to 10 years of age. Findings were compared with age-matched controls. Large, reelin-positive CR-like cells were more numerous in the majority of the polymicrogyria cases and persisted for longer than usual, up to 10 years of age. The CR-like cells tended to cluster and were most frequent in fused molecular layers in the polymicrogyria. Reelin-expressing CR-like cells were also found in bridges between the molecular layer and overlying leptomeningeal heterotopia and within the heterotopia itself. Clusters of CR-like cells were also found in adjacent non-polymicrogyric cortex. No clusters were seen in the control subjects. Increased numbers of CR-like cells were seen in both familial and acquired cases. In contrast to previous reports, the findings show that large CR-like cells persisted for longer than usual, up to 10 years of age, and that they may continue to express reelin. Their maximal aggregation in regions of polymicrogyria and overlying leptomeningeal heterotopia suggest an association between the presence of these cells and polymicrogyria, which we interpret in the light of recent findings concerning the roles of reelin and its downstream signalling pathway in neuronal and glial developmental dynamics and post-developmental function.
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Affiliation(s)
- S H Eriksson
- The National Society for Epilepsy and Epilepsy Research Group, University Department of Clinical Neurology, University College London, UK
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Lin WR, Lin HH, Lee SS, Tsai HC, Huang CK, Wann SR, Chen YS, Chiang SC, Yen MY, Liu YC. Comparative study of the efficacy and safety of valaciclovir versus acyclovir in the treatment of herpes zoster. J Microbiol Immunol Infect 2001; 34:138-42. [PMID: 11456360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Acyclovir, a specific and selective inhibitor of the replication of Herpesviridae family, has well-documented efficacy and tolerability in the treatment of herpes zoster. Its limited oral bioavailability and short half-life, however, necessitates frequent dosing. Valaciclovir, the l-valyl ester of acyclovir, could be rapidly converted to acyclovir after oral administration, resulting in a three- to five-fold increase in acyclovir bioavailability compared with oral acyclovir in humans. Valaciclovir allows less frequent dosing and maintains the safety profiles of the parent drug. During the period from October 1996 through May 1998, a randomized, prospective study was performed in the Kaohsiung Veterans General Hospital to compare the safety and efficacy of valaciclovir with acyclovir in the treatment of herpes zoster in Taiwanese patients. Patients presenting with herpes zoster within 72 h after the onset of rash were enrolled and randomized to receive one of the following treatments: 1000 mg valaciclovir three times daily for 7 days or acyclovir 800 mg five times daily for 7 days. Patients were followed up for 29 days beginning with the start of therapy. A total of 57 patients were enrolled and randomized to receive valaciclovir (n = 32) or acyclovir (n = 25). Five patients in the valaciclovir group and three in the acyclovir group did not complete the study. The intent-to-treat analysis (57 patients) showed that valaciclovir significantly accelerated the resolution of herpes zoster-associated pain compared with acyclovir; on day 29, the valaciclovir group was 23% superior to the acyclovir group. There was no clinically significant difference in the nature, frequency or severity of adverse events between these two groups, although one and three adverse events were reported in the acyclovir and valaciclovir group, respectively. Thus, we conclude that in the management of herpes zoster, valaciclovir accelerates the resolution of pain and offers a simpler dosing, and maintains the favorable safety profile of acyclovir.
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Affiliation(s)
- W R Lin
- Department of Medicine, Kaohsiung Veterans General Hospital, Taiwan, ROC
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Tsai HC, Lee SS, Lin WR, Huang CK, Chen YS, Wann SR, Lin HH, Yen MY, Liu YC. Legionnaires' disease in an immunocompetent young adult. Kaohsiung J Med Sci 2001; 17:331-5. [PMID: 11559972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Infection with Legionella pneumophila (LP) is a rare cause of pneumonia in previously healthy young adults. Pleural effusion is relatively common in Legionnaires' disease but is usually clinically insignificant. Herein we describe an immunocompetent, 19-year-old female with LP respiratory infection that presented with pleural effusion and mild interstitial infiltrates in the lower lungs. She received 3 weeks' treatment with erythromycin and rifampin and recovered completely. Diagnosis was based on serology testing with a four-fold rise of the antibody titer in the acute and convalescent phase. Legionnaires' disease should be considered in the differential diagnosis of culture-negative pleural effusion in immunocompetent young adults.
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Affiliation(s)
- H C Tsai
- Section of Infectious Diseases, Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, National Yang-Ming University, Taipei, Taiwan
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Tsai TH, Liu YC, Wann SR, Lin WR, Lee SJ, Lin HH, Chen YS, Yen MY, Yen CM. An outbreak of meningitis caused by Angiostrongylus cantonensis in Kaohsiung. J Microbiol Immunol Infect 2001; 34:50-6. [PMID: 11321128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Eight Thai laborers developed meningitis after eating raw snails (Ampullarium canaliculatus) during the period from September 27 to October 6, 1998. The diagnosis of Angiostrongylus cantonensis infection was established in all patients by serologic studies of serum and cerebral spinal fluid (CSF). Clinical manifestations included meningitis, radiculitis and cranial nerve palsy. Symptoms included fever, headache, orbital pain, gastrointestinal upset, hyperesthesia, muscle weakness, skin rash and diplopia. Laboratory abnormalities included peripheral eosinophilia, CSF eosinophilia, transient elevation of liver enzymes and creatinine phosphokinase, elevation of IgE. No space occupying lesions were detected by magnetic resonance imaging of the brain. None of the patients developed severe sequelae during the 6-month follow-up except for occasional headache in one patient. This report also provides evidence that third stage larvae were present in the intermediate host, A. canaliculatus, which the laborers had eaten.
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Affiliation(s)
- T H Tsai
- Department of Medicine, Veterans Hospital-Chiayi, Taiwan, ROC
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Abstract
Drug resistance in epilepsy is poorly understood. We used routine immunohistochemistry to assess overexpression of a multidrug-resistance protein in dysplastic neurons, glia, and around vessels in surgically resected epileptogenic human brain tissue. We showed non-tumoral overexpression of this multidrug-resistance protein, which might contribute to drug resistance in epilepsy caused by focal cortical dysplasia.
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Abstract
It was previously found that herpes simplex type 1 virus (HSV1) when present in the brain, is a risk factor for Alzheimer's disease in carriers of the type 4 allele of the gene for apolipoprotein E (apoE epsilon4), and apoE epsilon4 is a risk factor for herpes labialis. Whether a specific allele of the gene is involved in susceptibility to another disorder caused by HSV1-herpes simplex encephalitis (HSE)-has now been investigated. DNA was prepared from formalin-fixed, paraffin-embedded blocks of specimens from the brain or spleen of 14 United Kingdom patients with HSE, confirmed by necropsy, and from the CSF of seven United Kingdom clinical patients with HSV1 in their CSF detected by polymerase chain reaction (PCR). ApoE genotype of the DNA from blocks was determined by seminested PCR, and of the DNA from CSF by one step PCR, followed by restriction endonuclease digestion. The apoE allele frequencies were compared with values previously obtained for 238 normal people from the United Kingdom. The apoE epsilon2 allele frequency of the patients with HSE was 26%, significantly higher than the value of 7% for the normal subjects (OR=4.6, 95% confidence interval (95% CI) 2. 0-10.8). The apoE epsilon3 and epsilon4 allele frequencies did not differ significantly between the two groups. Thus, it seems that apoE epsilon2 is a risk factor for HSE.
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Affiliation(s)
- W R Lin
- Molecular Neurobiology Laboratory, Department of Optometry and Neuroscience, UMIST, Manchester M60 1QD, UK
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Lee SS, Liu YC, Wann SR, Lin WR, Tsai TH, Lin HH, Chen YS, Yen MY. Once daily isepamicin treatment in complicated urinary tract infections. J Microbiol Immunol Infect 1999; 32:105-10. [PMID: 11561574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Isepamicin is a new aminoglycoside, derived from gentamicin B, which is more stable than other aminoglycosides against inactivating enzymes, and is less nephrotoxic. We evaluated the efficacy and safety of a once daily isepamicin in the treatment of complicated urinary tract infections (UTIs), as compared with amikacin. During the period May, 1997, to January, 1998, a total of 52 patients with similar demographic and baseline characteristics were enrolled into a prospective, randomized, open-label, single-center trial at the Veterans General Hospital-Kaohsiung. Eleven patients were excluded for protocol violation. The remaining 41 patients were included in the efficacy analysis. Study subjects included 16 men and 25 women, with a mean age of 57.9 (range 18-95) years. Clinical improvement was noted in 100% of patients in both the isepamicin and amikacin group. No statistically significant difference was observed between the 2 groups in regard to the rapidity of defervescence, relief of dysuria and urinary frequency, and clearance of bacteriuria and pyuria. Bacteriological cure rates were 89.4% for the isepamicin group and 100% for the amikacin group. Fifteen of 25 subjects who received isepamicin and 16 of 27 subjects who received amikacin had an adverse effect, all of which were considered to be mild except for one in the amikacin group, who had an adverse event of moderate severity (vomiting). Seven (3 isepamicin and 4 amikacin) adverse events were considered probably or possibly related to the study drug, which included eosinophilia (2 isepamicin), liver function impairment (1 isepamicin, 2 amikacin), renal function impairment (1 amikacin) and flushed face (1 amikacin). However, none of the patients had a life-threatening or severe adverse event that required discontinuation of the drug. These results show that once daily administration of isepamicin is as effective and safe as amikacin in treatment of complicated UTIs.
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Affiliation(s)
- S S Lee
- Department of Medicine, Veterans General Hospital-Kaohsiung, Taiwan, ROC
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Abstract
Our previous studies showed that herpes simplex type 1 virus (HSV1) is present in a high proportion of the brain of elderly normal people and Alzheimer's disease (AD) patients. We subsequently discovered that the combination of HSV1 in brain and carriage of the type 4 allele of the gene for apolipoprotein E (apoE-epsilon 4) is a strong risk factor for AD, and also that apoE-epsilon 4 is a strong risk factor for herpes labialis. In this study we have examined apoE genotypes of sufferers from another disorder caused by HSV1, namely, herpes simplex keratitis (HSK), to find if an apoE allele is involved in the disorder. In 46 HSK patients the apoE-epsilon 4 allele frequency was 15%-the same as that found in 238 unaffected controls. The apoE-epsilon 2 allele frequency was 13%-higher than the value of 7% for unaffected people, but the difference is not statistically significant.
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Affiliation(s)
- W R Lin
- Department of Optometry and Vision Sciences, UMIST, Manchester, UK
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Ozcengiz G, Kim JH, Lin WR, Ozcengiz E, Westenberg D, Lynd LR, Demain AL. Superiority of the PCR-based approach for cloning the acetate kinase gene of Clostridium thermocellum. J Ind Microbiol Biotechnol 1998. [DOI: 10.1038/sj.jim.2900567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Itzhaki RF, Lin WR. Herpes simplex virus type I in brain and the type 4 allele of the apolipoprotein E gene are a combined risk factor for Alzheimer's disease. Biochem Soc Trans 1998; 26:273-7. [PMID: 9649761 DOI: 10.1042/bst0260273] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- R F Itzhaki
- Department of Optometry and Vision Sciences, U.M.I.S.T., Manchester, U.K
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Lin WR, Casas I, Wilcock GK, Itzhaki RF. Neurotropic viruses and Alzheimer's disease: a search for varicella zoster virus DNA by the polymerase chain reaction. J Neurol Neurosurg Psychiatry 1997; 62:586-9. [PMID: 9219743 PMCID: PMC1074141 DOI: 10.1136/jnnp.62.6.586] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND In studies on the possible role of viruses in the aetiopathogenesis of Alzheimer's disease, herpes simplex virus type 1 (HSV1) DNA was detected by the polymerase chain reaction (PCR) in a high proportion of normal elderly people and of patients with Alzheimer's disease. The combination of HSV1 and a host factor, the type 4 allele of the gene for apolipoprotein E, is a strong risk factor for the disease. METHODS Brain specimens were examined for another herpes virus, varicella zoster (VZV), which, like HSV1, is neurotropic, has a predilection for residing latently in the peripheral nervous system, and can reactivate. RESULTS Using primers for sequences in the VZV origin of replication gene or thymidine kinase gene, VZV DNA was not found in any of 24 samples (18 HSV1 positive), from 17 patients with Alzheimer's disease, nor in 20 samples (12 HSV1 positive from 12 aged normal people. Hybridisation of the PCR products with a radiolabelled oligonucleotide probe capable of detecting less than 10 copies of the target sequence, confirmed the absence of VZV DNA. CONCLUSION The presence of one neurotropic virus--HSV1--and the absence of another--VZV--in aged human brains is consistent with a role for HSV1 in the aetiology of Alzheimer's disease.
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Affiliation(s)
- W R Lin
- Department of Optometry and Vision Sciences, UMIST, Manchester, UK
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Abstract
BACKGROUND The apolipoprotein E epsilon 4 (APOE-epsilon 4) allele is a risk factor for Alzheimer's disease (AD), but it is neither essential nor sufficient for development of the disease. Other factors-genetic or environmental-must therefore have a role. By means of a PCR we have detected herpes simplex virus type 1 (HSV1) in latent form in brains of elderly people with and without AD. We have postulated that limited reactivation of the virus causes more damage in AD patients than in elderly people without AD because of a difference in the hosts. We now report the APOE genotypes of AD patients and non-AD sufferers with and without HSV1 in brain. METHODS DNA was extracted from 84 samples of brain from 46 AD patients (39 temporal lobe, 39 frontal lobe, three hippocampus) and from 75 samples of brain from 44 non-AD elderly people (33 temporal lobe, 36 frontal lobe, six hippocampus). PCR amplification was used to detect HSV1 thymidine kinase gene and the host APOE gene. FINDINGS By multiple logistic regression, the APOE-epsilon 4 allele frequency was significantly higher in the patients positive for HSV1 in brain than in the HSV1-negative AD group, the HSV1-positive non-AD group, or the HSV1-negative non-AD group (52.8% vs 10.0%, 3.6%, and 6.3%, respectively). The odds ratio for APOE-epsilon 4 in the HSV1-positive AD group compared with HSV1-negative non-AD group was 16.8 (95% CI 3.61-77.8) and in the HSV1-negative AD group, 1.67 (0.21-13.4). We also compared APOE genotypes of 40 people who had recurrent cold sores and 33 non-sufferers; the APOE-epsilon 4 allele frequencies were 36% and 9%, respectively (p < 0.0001). INTERPRETATION These findings suggest that the combination of HSV1 in brain and carriage of an APOE-epsilon 4 allele is a strong risk factor for AD, whereas either of these features alone does not increase the risk of AD. The findings in people with cold sores support our hypothesis that APOE-epsilon 4 and HSV1 together are damaging in the nervous system.
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Affiliation(s)
- R F Itzhaki
- Molecular Neurobiology Laboratory, Department of Optometry and Vision Sciences, UMIST, Manchester
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Lin WR, Shang D, Itzhaki RF. Neurotropic viruses and Alzheimer disease. Interaction of herpes simplex type 1 virus and apolipoprotein E in the etiology of the disease. Mol Chem Neuropathol 1996; 28:135-41. [PMID: 8871952 DOI: 10.1007/bf02815215] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Infectious agents have been proposed as possible etiological factors in sporadic cases of Alzheimer disease (AD), herpes simplex type 1 virus (HSV1) being a likely candidate. We have detected laten HSV1 in brain from AD patients and from aged normal individuals, using polymerase chain reaction (PCR), in the regions most affected in the disease. In contrast, we have not detected another neurotropic herpes virus, varicella zoster (VZV), in any brains. We have postulated that HSV1 reactivates periodically, and that a host or viral characteristic determines the degree of damage caused by the resulting acute infection-with much greater damage in the case of AD patients. We have therefore examined a host factor-the apolipoprotein E (apoE) genotype, since the E4 allele is a known risk factor in the disease. We have found that the risk of developing AD is much greater in those who are HSV1-positive in brain and who possess an apoE4 allele than for those with only one of these factors.
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Affiliation(s)
- W R Lin
- Department of Optometry and Vision Sciences, UMIST., Manchester, UK
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Affiliation(s)
- W R Lin
- Department of Optometry & Vision Sciences, UMIST, Manchester, U.K
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Abstract
In the present study, we investigated the neural mechanisms of corticotropin-releasing factor (CRF) and the interactions among CRF, norepinephrine (NE), and N-methyl-D-aspartate (NMDA) systems in the dentate gyrus (DG) of hippocampus in modulating the memory process of rats. One-way passive avoidance task was adopted. Results indicated that CRF (80 ng), when directly injected into the DG, consistently and significantly enhanced memory retention in rats. The noradrenergic neurotoxin DSP-4, at a high dose (4 micrograms), impaired memory. DSP-4 at a moderate dose (2 micrograms), which did not affect retention alone, antagonized the memory-enhancing effect of CRF. Similarly, the beta-adrenergic antagonist propranolol, at a high dose (8 micrograms), reduced retention. At a low dose (80 ng), which did not markedly affect retention by itself, propranolol also prevented the memory-improving effect of CRF. Moreover, direct NE infusions to the DG significantly improved retention performance in a dose-sensitive manner. Coadministration of CRF and NE did not further enhance retention. These results together suggest that CRF and NE facilitated memory probably through the same instead of independent mechanisms. In contrast, the selective NMDA receptor antagonists 2-amino-5-phosphonopentanoate (AP5) and MK801, at high doses markedly impaired memory retention (0.8 and 3.2 micrograms for AP5, 2 and 10 micrograms for MK801). At a dose of MK801 that did not significantly alter retention alone (80 ng), it completely blocked the memory-facilitating effect of CRF. These results indicate that CRF enhanced memory indirectly through NMDA receptor mediation also. Finally, MK801 at 80 ng also successfully antagonized the memory-facilitating effect of NE in the DG. We have demonstrated that MK801, at the dose chosen for interaction studies, did not markedly alter locomotor activity. These results together suggest that CRF, through a presynaptic facilitation mechanism, possibly facilitates NE release in the DG; increased NE release and stimulation of beta-adrenergic receptors in the DG result in NMDA receptor activations in the same area. This sequence of events enhance the memory consolidation process in the hippocampus and explained the neural mechanism of CRF in facilitating retention performance in rats. The same neuropeptide/neurotransmitter interactions may have other physiological and neuropathological implications.
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Affiliation(s)
- E H Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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Lee EH, Lin WR, Chen HY, Shiu WH, Liang KC. Fluoxetine and 8-OH-DPAT in the lateral septum enhances and impairs retention of an inhibitory avoidance response in rats. Physiol Behav 1992; 51:681-8. [PMID: 1534416 DOI: 10.1016/0031-9384(92)90103-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study investigated the role of lateral septal serotonin (5HT) in memory consolidation and the subtype of 5HT receptors involved in this process. Rats with cannulae implanted bilaterally into the lateral septum were trained in an inhibitory avoidance task. Immediately after training, the septal serotonergic function was manipulated by pharmacological agents selectively blocking 5HT reuptake (fluoxetine and zimelidine), antagonizing 5HT2 receptors (ketanserin and ritanserin), or activating 5HT1A receptors, respectively. Results indicated that direct fluoxetine infusions into the lateral septum at a dose of 6 micrograms/0.5 microliter and zimelidine at a dose of 5 micrograms/0.5 microliter both markedly enhanced memory. Intralateral septal injections of ketanserin (0.3 microgram/0.5 microliter and 0.5 microgram/0.5 microliter) and ritanserin (0.3 microgram/0.5 microliter and 0.6 microgram/0.5 microliter) did not have a significant effect by themselves on memory, and neither did they attenuate the memory-facilitating effect of fluoxetine in the same area. Intralateral septal infusions of 8-hydroxy-2-(di-n-propylamino)tetralin at 5 micrograms/0.5 microliter significantly impaired memory retention. These findings altogether support the notion that the lateral septal nuclei of rats are involved in the memory processes of inhibitory avoidance learning. Furthermore, postsynaptic 5HT receptor activation (not the 5HT2 receptor subtype) probably exerts a facilitatory effect while presynaptic 5HT1A receptor activation exerts an impairing effect on the memory consolidation process, probably due to autoreceptor inhibition of 5HT release.
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Affiliation(s)
- E H Lee
- Institute of Biomedical Sciences, Academia Sinica, National Taiwan University, Taipei, Republic of China
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Lee EH, Liu SP, Lu KT, Lin WR. Comparative studies of the neurotoxicity of MPTP in rats of different ages. CHINESE J PHYSIOL 1992; 35:317-36. [PMID: 1364057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
The present study investigated the neurotoxic effects of repeated MPTP injections on monoamine neurotransmitters and locomotor activity in rats of different ages. We also examined the mortality of MPTP-treated rats at different ages. Male Sprague-Dawley rats were used in all experiments. In the first experiment, we examined the mortality of rats (11-12 month old) subject to different doses of MPTP. In the second experiment, rats of 2-3 months old were randomly divided into five groups. Group 1 served as the control; Groups 2,3,4 and 5 received daily MPTP injections (30 mg/kg, ip) for a continuation of 7 days. Biochemical and behavioral assays were conducted at 1,7,14 and 28 days after withdrawal of MPTP, respectively. In the third and fourth experiments, the same experimental design was adopted except that rats of 5-6 months old and rats of 11-12 months old were used, respectively. Besides, the doses of MPTP used were 22.5 mg/kg and 12.5 mg/kg, respectively. Immunohistochemical experiments were always conducted 7 days after withdrawal of MPTP. Results indicated that, in young rats, repeated MPTP injections did not significantly decrease DA, and 5HT levels as well as TH and DBH immunoreactivities although it impaired locomotor activity. The same treatment significantly depleted DA, NE and 5HT levels in the middle-aged rats. It also decreased the density of TH and DBH immunoreactivities and altered the morphology of DA and NE neurons. Meanwhile, it impaired locomotor activity. In old rats, MPTP injections produced effects similar to those observed in the middle-age rats except that the hippocampal serotonergic system was also affected. However, all these effects recovered 28 days after withdrawal of MPTP injection. Finally, the dose of MPTP required to exert similar extent of neurotoxicity decreased as the age of rats increased, and the dose required to result in mortality markedly decreased in old rats. These results together suggest that MPTP does exert a toxicity on DA, NE and 5HT neurons and impair motor activity in rats. These effects are age-dependent while the irreversibility of MPTP's toxicity in rats requires further investigation.
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Affiliation(s)
- E H Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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Abstract
The effects of two calcium channel blockers, nifedipine and verapamil, and the peptide corticotropin releasing factor (CRF) as well as their interactive effects on memory retention were examined in rats. Male Sprague-Dawley rats were chronically cannulated bilaterally and drugs were directly injected into the dentate gyrus of the hippocampus. Animals were trained in a one-way inhibitory avoidance task and memory was measured 24 h later. Results indicate that there was a U-shaped dose-response curve for the effects of nifedipine and verapamil with nifedipine at 8 micrograms and verapamil at 1 microgram both impaired memory formation, while CRF at 0.1 microgram enhanced this process. Nifedipine at 2 micrograms and verapamil at 0.5 microgram, which did not have significant effects on memory by themselves, antagonized the memory-enhancing effect of CRF in the hippocampus. These results suggest that under normal physiological conditions, calcium influx may play an important role in memory consolidation process in the vertebrate.
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Affiliation(s)
- E H Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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