1
|
Xu Z, Feng J, Yu D, Huo Y, Ma X, Lam WH, Liu Z, Li XD, Ishibashi T, Dang S, Zhai Y. Synergism between CMG helicase and leading strand DNA polymerase at replication fork. Nat Commun 2023; 14:5849. [PMID: 37730685 PMCID: PMC10511561 DOI: 10.1038/s41467-023-41506-0] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 09/07/2023] [Indexed: 09/22/2023] Open
Abstract
The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-electron microscopy structures of a yeast replisome comprising CMG, leading-strand polymerase Polε and three accessory factors on a forked DNA. In these structures, Polε engages or disengages with the motor domains of the CMG by occupying two alternative positions, which closely correlate with the rotational movement of the single-stranded DNA around the MCM pore. During this process, the polymerase remains stably coupled to the helicase using Psf1 as a hinge. This synergism is modulated by a concerted rearrangement of ATPase sites to drive DNA translocation. The Polε-MCM coupling is not only required for CMG formation to initiate DNA replication but also facilitates the leading-strand DNA synthesis mediated by Polε. Our study elucidates a mechanism intrinsic to the replisome that coordinates the activities of CMG and Polε to negotiate any roadblocks, DNA damage, and epigenetic marks encountered during translocation along replication forks.
Collapse
Affiliation(s)
- Zhichun Xu
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Jianrong Feng
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Daqi Yu
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Yunjing Huo
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Xiaohui Ma
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Wai Hei Lam
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Zheng Liu
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Xiang David Li
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Toyotaka Ishibashi
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science & Technology, Hong Kong, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
- HKUST-Shenzhen Research Institute, 518057, Nanshan, Shenzhen, China.
| | - Yuanliang Zhai
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
| |
Collapse
|
2
|
Lam AKC, Lai HC, Sung YK, Lam WH, Tiu CM. Performance of neuroretinal rim thickness measurement by Cirrus high-definition optical coherence tomography in myopic eyes. Sci Rep 2023; 13:12714. [PMID: 37543611 PMCID: PMC10404224 DOI: 10.1038/s41598-023-39701-6] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 07/29/2023] [Indexed: 08/07/2023] Open
Abstract
Neuroretinal rim (NRR) measurement can aid the diagnosis of glaucoma. A few studies reported that Cirrus optical coherence tomography (OCT) had NRR segmentation errors. The current study investigated segmentation success of NRR in myopic eyes using the Cirrus built-in software and to determine the number of acquisitions required to identify NRR thinning. Right eye of 87 healthy adult myopes had an optic disc scanned using Cirrus HD-OCT for five successive acquisitions. A masked examiner evaluated 36 radial line images of each scan to screen for segmentation errors using the built-in software at the Bruch's membrane opening (BMO) and/or internal limiting membrane (ILM). Participants with three accurate NRR acquisitions had their average NRR thickness determined. This result was compared with average of the two acquisitions and the first acquisition. Among 435 OCT scans of the optic disc (87 eyes × 5 acquisitions), 129 (29.7%) scans had segmentation errors that occurred mainly at the ILM. The inferior-temporal and superior meridians had slightly more segmentation errors than other meridians, independent of axial length, amount of myopia, or presence of peripapillary atrophy. Sixty-five eyes (74.7%) had at least three accurate NRR measurements. The three acquisitions had high reliability in NRR thickness in the four quadrants (intraclass correlation coefficient > 0.990, coefficient of variation < 3.9%). NRR difference between the first acquisition and the average of three acquisitions was small (mean difference 2 ± 13 μm, 95% limits of agreement within ± 30 μm) among the four quadrants. Segmentation errors in NRR measurements appeared regardless of axial length, amount of myopia, or presence of peripapillary atrophy. Cirrus segmentation lines should be manually inspected when measuring NRR thickness.
Collapse
Affiliation(s)
- Andrew K C Lam
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
- School of Optometry, Centre for Myopia Research, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Shatin, Hong Kong SAR, China.
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
| | - H C Lai
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Y K Sung
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - W H Lam
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - C M Tiu
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| |
Collapse
|
3
|
Lin J, Wu Y, Tian G, Yu D, Yang E, Lam WH, Liu Z, Jing Y, Dang S, Bao X, Wong JWH, Zhai Y, Li XD. Menin "reads" H3K79me2 mark in a nucleosomal context. Science 2023; 379:717-723. [PMID: 36795828 DOI: 10.1126/science.adc9318] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Methylation of histone H3 lysine-79 (H3K79) is an epigenetic mark for gene regulation in development, cellular differentiation, and disease progression. However, how this histone mark is translated into downstream effects remains poorly understood owing to a lack of knowledge about its readers. We developed a nucleosome-based photoaffinity probe to capture proteins that recognize H3K79 dimethylation (H3K79me2) in a nucleosomal context. In combination with a quantitative proteomics approach, this probe identified menin as a H3K79me2 reader. A cryo-electron microscopy structure of menin bound to an H3K79me2 nucleosome revealed that menin engages with the nucleosome using its fingers and palm domains and recognizes the methylation mark through a π-cation interaction. In cells, menin is selectively associated with H3K79me2 on chromatin, particularly in gene bodies.
Collapse
Affiliation(s)
- Jianwei Lin
- Department of Chemistry, University of Hong Kong, Hong Kong SAR, China
| | - Yiping Wu
- Department of Chemistry, University of Hong Kong, Hong Kong SAR, China
| | - Gaofei Tian
- Department of Chemistry, University of Hong Kong, Hong Kong SAR, China
| | - Daqi Yu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Eunjeong Yang
- School of Biomedical Sciences, University of Hong Kong, Hong Kong SAR, China.,Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Wai Hei Lam
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Zheng Liu
- Department of Chemistry, University of Hong Kong, Hong Kong SAR, China
| | - Yihang Jing
- Greater Bay Biomedical InnoCenter, Shenzhen Bay Laboratory, Shenzhen, China
| | - Shangyu Dang
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Xiucong Bao
- School of Biomedical Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Jason Wing Hon Wong
- School of Biomedical Sciences, University of Hong Kong, Hong Kong SAR, China.,Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong SAR, China
| | - Yuanliang Zhai
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Xiang David Li
- Department of Chemistry, University of Hong Kong, Hong Kong SAR, China.,Greater Bay Biomedical InnoCenter, Shenzhen Bay Laboratory, Shenzhen, China
| |
Collapse
|
4
|
Woo PCY, Lau SKP, Lau CCY, Tung ETK, Chong KTK, Yang F, Zhang H, Lo RKC, Cai JP, Au-Yeung RKH, Ng WF, Tse H, Wong SSY, Xu S, Lam WH, Tse MK, Sze KH, Kao RY, Reiner NE, Hao Q, Yuen KY. Mp1p Is a Virulence Factor in Talaromyces (Penicillium) marneffei. PLoS Negl Trop Dis 2016; 10:e0004907. [PMID: 27560160 PMCID: PMC4999278 DOI: 10.1371/journal.pntd.0004907] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/14/2016] [Indexed: 12/03/2022] Open
Abstract
Background Talaromyces marneffei is an opportunistic dimorphic fungus prevalent in Southeast Asia. We previously demonstrated that Mp1p is an immunogenic surface and secretory mannoprotein of T. marneffei. Since Mp1p is a surface protein that can generate protective immunity, we hypothesized that Mp1p and/or its homologs are virulence factors. Methodology/Principal Findings We examined the pathogenic roles of Mp1p and its homologs in a mouse model. All mice died 21 and 30 days after challenge with wild-type T. marneffei PM1 and MP1 complemented mutant respectively. None of the mice died 60 days after challenge with MP1 knockout mutant (P<0.0001). Seventy percent of mice died 60 days after challenge with MP1 knockdown mutant (P<0.0001). All mice died after challenge with MPLP1 to MPLP13 knockdown mutants, suggesting that only Mp1p plays a significant role in virulence. The mean fungal loads of PM1 and MP1 complemented mutant in the liver, lung, kidney and spleen were significantly higher than those of the MP1 knockout mutant. Similarly, the mean load of PM1 in the liver, lung and spleen were significantly higher than that of the MP1 knockdown mutant. Histopathological studies showed an abundance of yeast in the kidney, spleen, liver and lung with more marked hepatic and splenic necrosis in mice challenged with PM1 compared to MP1 knockout and MP1 knockdown mutants. Likewise, a higher abundance of yeast was observed in the liver and spleen of mice challenged with MP1 complemented mutant compared to MP1 knockout mutant. PM1 and MP1 complemented mutant survived significantly better than MP1 knockout mutant in macrophages at 48 hours (P<0.01) post-infection. The mean fungal counts of Pichia pastoris GS115-MP1 in the liver (P<0.001) and spleen (P<0.05) of mice were significantly higher than those of GS115 at 24 hours post-challenge. Conclusions/Significance Mp1p is a key virulence factor of T. marneffei. Mp1p mediates virulence by improving the survival of T. marneffei in macrophages. Talaromyces (Penicillium) marneffei is an opportunistic thermal dimorphic fungus most prevalent in Southeast Asia. Our team has previously shown that Mp1p, a protein encoded by the MP1 gene, is an immunogenic surface and secretory protein of T. marneffei. In this study, we showed that mice challenged with T. marneffei with the MP1 gene died but those challenged with T. marneffei without the MP1 gene did not die. There was also significantly higher fungal load and more necrosis in organs of mice challenged with T. marneffei with the MP1 gene than T. marneffei without the MP1 gene. Furthermore, T. marneffei with the MP1 gene survived better in macrophages than T. marneffei without the MP1 gene and Pichia pastoris with the MP1 gene survived in mice better than P. pastoris without the MP1 gene. Our data support that Mp1p is a key virulence factor of T. marneffei and Mp1p mediates virulence by improving the survival of T. marneffei in macrophages.
Collapse
Affiliation(s)
- Patrick C. Y. Woo
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Susanna K. P. Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Candy C. Y. Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | | | - Ken T. K. Chong
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Fengjuan Yang
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Hongmin Zhang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Raymond K. C. Lo
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Jian-Pao Cai
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | | | - Wing-Fung Ng
- Department of Pathology, United Christian Hospital and Tseung Kwan O Hospital, Hong Kong
| | - Herman Tse
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Samson S. Y. Wong
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Simin Xu
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Wai Hei Lam
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Man-Kit Tse
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Kong Hung Sze
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Richard Y. Kao
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Neil E. Reiner
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Quan Hao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
- * E-mail:
| |
Collapse
|
5
|
Chen D, Milacic V, Chen MS, Wan SB, Lam WH, Huo C, Landis-Piwowar KR, Cui QC, Wali A, Chan TH, Dou QP. Tea polyphenols, their biological effects and potential molecular targets. Histol Histopathol 2008; 23:487-96. [PMID: 18228206 DOI: 10.14670/hh-23.487] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tea is the most popular beverage in the world, second only to water. Tea contains an infusion of the leaves from the Camellia sinensis plant rich in polyphenolic compounds known as catechins, the most abundant of which is (-)-EGCG. Although tea has been consumed for centuries, it has only recently been studied extensively as a health-promoting beverage that may act to prevent a number of chronic diseases and cancers. The results of several investigations indicate that green tea consumption may be of modest benefit in reducing the plasma concentration of cholesterol and preventing atherosclerosis. Additionally, the cancer-preventive effects of green tea are widely supported by results from epidemiological, cell culture, animal and clinical studies. In vitro cell culture studies show that tea polyphenols potently induce apoptotic cell death and cell cycle arrest in tumor cells but not in their normal cell counterparts. Green tea polyphenols were shown to affect several biological pathways, including growth factor-mediated pathway, the mitogen-activated protein (MAP) kinase-dependent pathway, and ubiquitin/proteasome degradation pathways. Various animal studies have revealed that treatment with green tea inhibits tumor incidence and multiplicity in different organ sites such as skin, lung, liver, stomach, mammary gland and colon. Recently, phase I and II clinical trials have been conducted to explore the anticancer effects of green tea in humans. A major challenge of cancer prevention is to integrate new molecular findings into clinical practice. Therefore, identification of more molecular targets and biomarkers for tea polyphenols is essential for improving the design of green tea trials and will greatly assist in a better understanding of the mechanisms underlying its anti-cancer activity.
Collapse
Affiliation(s)
- D Chen
- The Prevention Program, Barbara Ann Karmanos Cancer Institute and Department of Pathology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Chow LMC, Tang JCO, Teo ITN, Chui CH, Lau FY, Leung TWT, Cheng G, Wong RSM, Wong ILK, Tsang KMS, Tan WQ, Zhao YZ, Lai KB, Lam WH, Guo DA, Chan ASC. Antiproliferative activity of the extract of Gleditsia sinensis fruit on human solid tumour cell lines. Chemotherapy 2004; 48:303-8. [PMID: 12673105 DOI: 10.1159/000069713] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [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: 11/19/2022]
Abstract
BACKGROUND The fruit extract of Gleditsia sinensis Lam. (GSE) is a traditional herbal medicine that is saponin-rich. However, its activity on solid tumour cell lines has never been demonstrated. METHODS The activity of GSE was demonstrated in four cancer cell lines (breast cancer MCF-7, MDA-MB231, hepatoblastoma HepG2 and oesophageal squamous carcinoma cell line SLMT-1) using MTT assay, anchorage-independent clonogenicity assay, DNA laddering and in situ cell death detection. RESULTS The mean MTT(50) (the mean concentration of GSE to reduce MTT activity by 50%) ranged from 16 to 20 microg/ml of GSE. An anchorage-independent clonogenicity assay showed that all of the four solid tumour cell lines gradually lost their regeneration potential after treatment with GSE, DNA fragmentation and TUNEL analysis demonstrated that the action of GSE is both dose- and time course-dependent. CONCLUSIONS Our results suggest that GSE has a cytotoxic activity and can induce apoptosis in human solid tumour cell lines.
Collapse
Affiliation(s)
- L M C Chow
- Department of Applied Biology and Chemical Technology and Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis, Hong Kong Polytechnic University, China.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Kannan K, Battula S, Loganathan BG, Hong CS, Lam WH, Villeneuve DL, Sajwan K, Giesy JP, Aldous KM. Trace organic contaminants, including toxaphene and trifluralin, in cotton field soils from Georgia and South Carolina, USA. Arch Environ Contam Toxicol 2003; 45:30-36. [PMID: 12948170 DOI: 10.1007/s00244-002-0267-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Residues of organic contaminants--including toxaphene, DDT, trifluralin, hexachlorocyclohexanes, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs) and nonylphenol--were measured in 32 cotton field soils collected from South Carolina and Georgia in 1999. Toxaphene, trifluralin, DDT and PAHs were the major contaminants found in these soils. The maximum concentration of toxaphene measured was 2,500 ng/g dry weight. Trifluralin was detected in all the soils at concentrations ranging from 1 to 548 ng/g dry weight. Pesticide residues were not proportional to soil organic carbon content, indicating that their concentrations were a reflection of application history and dissipation rates rather than air-soil equilibrium. Soil extracts were also subjected to in vitro bioassays to assess dioxinlike, estrogenic, and androgenic/glucocorticoid potencies. Relatively more polar fractions of the soils elicited estrogenic and androgenic/glucocorticoid activities, but the magnitude of response was much less than those found in coastal marine sediments from industrialized locations.
Collapse
Affiliation(s)
- K Kannan
- Wadsworth Center, New York State Department of Health, Albany, New York 12201-0509, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
Cyclin-dependent protein kinase 5 (Cdk5) depends on the association with neuronal Cdk5 activator (Nck5a) for kinase activity. A variety of cellular proteins have been shown to undergo high affinity association with Nck5a, including three novel proteins, C42, C48, and C53 found by a yeast two-hybrid screen (Ching, Y. P., Qi, Z., and Wang, J. H. (2000) Gene 242, 285-294). The three proteins show competitive binding to Nck5a suggesting that they bind at a common site. The binding site has been mapped to a region of 26 amino acid residues (residues 145 to 170) at the N-terminal boundary of the kinase activation domain of Nck5a. This region of Nck5a contains an amphipathic alpha-helix whose hydrophobic face is involved in Cdk5 activation (Chin, K. T., Ohki, S, Tang, D., Cheng, H. C., Wang, J. H. , and Zhang, M. (1999) J. Biol. Chem. 274, 7120-7127). Several lines of evidence suggest that Nck5a interacts with the binding proteins at the hydrophilic face of the amphipathic alpha-helix. First, the Nck5a-(145-170) peptide can bind Cdk5 and Nck5a-binding proteins simultaneously. Second, the association of Nck5a-(145-170) to C48 can be markedly reduced by high ionic strength whereas the interaction between Nck5a and Cdk5 is not affected. Third, substitution of Glu(157) by glutamine in Nck5a-(145-170) abolishes the peptide's ability to bind to the three Nck5a-binding proteins without diminishing its Cdk5 binding activity.
Collapse
Affiliation(s)
- X Wang
- Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peoples Republic of China
| | | | | | | | | | | |
Collapse
|
9
|
Abstract
Trauma is the commonest cause of hospital admission in children. Head injuries are present in 75% of children with trauma and 70% of all traumatic deaths are due to the head injury. The mechanism of brain injury is examined, resulting from the effects of the primary insult and secondary ischaemic damage. Therapeutic interventions will be discussed with specific emphasis on outcome studies. However, institution of adequate oxygen delivery and haemodynamic stability in the child at the earliest moment remains the most important aspect of the management plan.
Collapse
Affiliation(s)
- W H Lam
- Department of Anaesthesia, Great Ormond Street Hospital for Children, NHS Trust, London, UK
| | | |
Collapse
|
10
|
French GW, Lam WH, Rashid Z, Sear JW, Foëx P, Howell S. Peri-operative silent myocardial ischaemia in patients undergoing lower limb joint replacement surgery: an indicator of postoperative morbidity or mortality? Anaesthesia 1999; 54:235-40. [PMID: 10364858 DOI: 10.1046/j.1365-2044.1999.00713.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One hundred and twenty-seven patients undergoing major lower limb joint replacement surgery were studied to determine the incidence of silent myocardial ischemia and to ascertain any link between pre-operative cardiac risk factors, silent myocardial ischaemia and postoperative morbidity. Patients underwent ambulatory ECG monitoring for 4 days (on the pre-operative night and for 3 days postoperatively). Postoperative cardiorespiratory symptomatology and morbidity was assessed by questionnaire at 3 months. Eighty-seven patients had risk factors for silent myocardial ischaemia; 42 patients (30 with risk factors) had peri-operative silent myocardial ischaemia. The median ischaemic loads (range) were 1.04 (0.32-13.31) min.h-1 pre-operatively and 5.53 (0.26-56.39), 6.69 (0.04-42.71) and 1.23 (0.1-53.74) min.h-1 on postoperative days 1-3, respectively. Risk factors did not predict the occurrence of silent myocardial ischaemia or an increased ischaemic load pre-operatively or overall postoperatively. New symptoms (chest pain, palpitations, breathlessness or fatigue) were associated with both silent myocardial ischaemia and ischaemic load (p < 0.05). Thus cardiac risk factors do not predict the occurrence of silent myocardial ischaemia or adverse outcome. Peri-operative silent myocardial ischaemia was associated with increased postoperative fatigue.
Collapse
Affiliation(s)
- G W French
- Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Headington, UK
| | | | | | | | | | | |
Collapse
|
11
|
Lam WH, Evans JM. Rubber gloves and anaesthetic gas leak. Anaesthesia 1996; 51:1075-6. [PMID: 8943608 DOI: 10.1111/j.1365-2044.1996.tb15015.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|